Induction of citrate synthase by aldosterone in the rat kidney.

The possible induction of renal citrate synthase (E.C. 4.1.3.7) by aldosterone was evaluated in the adrenalectomized rat. Three hours after administration of aldosterone (0.8 microgram/100 g body wt), renal cortical and medullary citrate synthase activity was significantly increased as reported previously by Kinne and Kirsten (Kinne, R., Kirsten, R. 1968. Pfleugers Arch. 300:244). In contrast, no change in this activity was detected in the renal papilla or the liver, under the same conditions. Kinetic analysis revealed that injection of aldosterone had no effect on the KmS for acetyl-CoA and oxalacetate but augmented Vmax of renal medullary citrate synthase activity by 40%. The aldosterone-dependent increase in medullary citrate synthase activity was proportionate to the associated increase in the quantity of antiserum (specific for citrate synthase) required for half-maximal immuno-precipitation. The possibility that aldosterone induced the synthesis of citrate synthase was evaluated in two sets of experiments. In the first set, adrenalectomized rats were injected intraperitoneally with either aldosterone (0.8 microgram/100 g body wt) or the diluent, and simultaneously with 3H or 35S methionine (500 muCi/rat). The isotopes were reversed in about half of the experiments. Three hours after the injection, renal citrate synthase was isolated by ATP-sepharose column chromatography and immuno-precipitation with the specific antiserum. Aldosterone augmented methionine incorporation into renal citrate synthase by 55% but had no effect on incorporation into the hepatic enzyme. In the second set, adrenalectomized rats were injected with either aldosterone (0.8 microcram/100 g body wt) or the diluent, the kidneys were removed 1 hr later and medullary slices were incubated in either 3H- or 35S-methionine at 20 degrees for 2 hr. Mitochondrial citrate synthase was isolated either by ATP-sepharose column chromatography and immuno-precipitation, or by polyacrylamide gel electrophoresis. Aldosterone increased methionine incorporation into the immuno-precipitates by 30% and into the enzyme peak resolved by polyacrylamide gel electrophoresis by 43%. The latter increase was eliminated by prior administration of either actinomycin D (70--80 microgram/100 g body wt) or spirolactone (SC-26304) (80 microgram/100 g body wt). An equimolar dose of dexamethasone (0.8 microgram/100 g body wt) had no effect on the isotope ratio associated with citrate synthase activity in the polyacrylamide gels.


Effect of lithium ion on melibiose transport in Escherichia coli.

Both Li+ and Na+ stimulated the uptake of thiomethylgalactoside by the melibiose transport system of Escherichia coli. On the other hand, Li+ inhibited the growht of cells on melibiose as a sole source of carbon. This inhibition was specific for melibiose, and Li+ had no effect on growth of cells on glucose, galactose, lactose, or glycerol. The effect of the cation on melibiose transport was investigated in a mutant which cannot utilize glucose. After entry into this cell, melibiose is cleaved into glucose and galactose by alpha-galactosidase, and the resulting glucose is excreted. Since the entry step was found to be rate-limiting, glucose production could be taken as a measure of melibose transport. Li+ inhibited the transport of melibiose, but not the induction of the melibiose operon nor the activity of alpha-galactosidase. Li+ was found to inhibit the entry of p-nitrophenyl-alpha-D-galactoside, but not p-nitrophenyl-beta-D-galactoside entry. Thus, the cation specificity for the melibiose membrane carrier varies different transport substrates.


A surgical procedure to prevent tracheo-innominate artery erosion.

The innominate artery of a patient requiring prolonged mechanical ventilation was palpated in the inferior portion of his tracheostomy wound. Life-threatening hemorrhage was prevented by rotation of a local muscle flap the protect the artery and rotation of pedicled skin flaps to create a permanent tracheostomy.


Correlation between UV dose requirement for lambda bacteriophage induction and lambda repressor concentration.

Escherichia coli K-12 wild type and a uvrA mutant derivative were used to construct isogenic strains bearing one, two, three, or more phage lambda cI genomes and containing increasing concentration of lambda repressor as measured by in vitro operator DNA-binding assays. The survival and phage induction in response to UV irradiation were determined. In both strains, dose-response relationships were obtained as a function of the cellular repressor concentration. The uvrA lysogens required one-tenth the UV fluence of the wild-type counterparts for induction. Lysogenic strains containing plasmids that overproduce the lambdaind+ repressor and the same lysogens with plasmids overproducing the lambdaind- repressor displayed the same survival curves as the nonlysogenic parental strain; however, only the former produced infectious centers (at a frequency of 2 x 10(-3) to 5 x 10(-4) in response to radiation.


Genome organization of RNA tumor viruses II. Physical maps of in vitro-synthesized Moloney murine leukemia virus double-stranded DNA by restriction endonucleases.

Physical maps of the genome of Moloney murine leukemia virus (M-MLV) DNA were constructed by using bacterial restriction endonucleases. The in vitro-synthesized M-MLV double-stranded DNA was used as the source of the viral DNA. Restriction endonucleases Sal I and Hind III cleave viral DNA at only one site and, thus, generate two DNA fragments. The two DNA fragments generated by Sal I are Sal IA (molecular weight, 3.5 x 10(6)) and Sal IB (molecular weight, 2.4 x 10(6)) and by Hind III are Hind IIIA (molecular weight, 3.6 x 10(6) and Hind IIIB (molecular weight, 2.3 x 10(6)). Restriction endonuclease Bam I generates four fragments of molecular weights of 2.1 x 10(6) (Bam IA), 2 X 10(6) (Bam IB), 1.25 X 10(6) (Bam IC), and 0.24 x 10(6) (Bam ID), whereas restriction endonuclease Hpa I cleaves the M-MLV double-stranded DNA twice to give three fragments of molecular weights of 4.4 x 10(6) (Hpa IA), 0.84 X 10(6) (Hpa IB), and 0.74 x 10(6) (Hpa IC). Digestion of M-MLV double-stranded DNA with restriction endonuclease Sma I produces four fragments of molecular weights of 3.9 x 10(6) (Sma IA), 1.3 X 10(6) (Sma IB), 0.28 X 10(6) (Sma IC), and 0.21 x 10(6) (Sma ID). A mixture of restriction endonucleases Bgl I and Bgl II (Bgl I + II) cleaves the viral DNA at four sites generating five fragments of approximate molecular weights of 2 x 10(6) (Bgl + IIA), 1.75 X 10(6) (Bgl I + IIB), 1.25 X 10(6) (Bgl I + IIC), 0.40 X 10(6) (Bgl I + IID), and 0.31 x 10(6) (Bgl I + IIE). The order of the fragments in relation to the 5' end and 3' end of the genome was determined either by using fractional-length M-MLV double-stranded DNA for digestion by restriction endonucleases or by redigestion of Sal IA, Sal IB, Hind IIIA, and Hind IIIB fragments with other restriction endonucleases. In addition, a number of other restriction endonucleases that cleave in vitro-synthesized M-MLV double-stranded DNA have also been listed.


Relatedness of the double-stranded RNAs present in yeast virus-like particles.

The relatedness of several double-stranded RNAs (dsRNA's) present in the virus-like particles of yeast was examined by T1 fingerprint analysis. The dsRNA's examined were L, the dsRNA encoding the capsid polypeptide of yeast virus-like particles; M, which appears to code for a toxic polypeptide and for resistance to the effects of the toxin; and two S dsRNA's present in particles analogous to the defective interfering particles of animal viruses. S3, a dsRNA of 0.46 X 10(6) daltons, was derived entirely from M, a dsRNA of 1.2 X 10(6) daltons. S1, a dsRNA of 0.92 X 10(6) daltons, was a duplication of S3. This conclusion has also been reached independently by heteroduplex mapping techniques (H. M. Fried and G. R. Fink, personal communication). S1 and S3, at least in one yeast strain, were unstable in sequence, apparently due to the accumulation of sequence variants of the same molecular weight. L was a species of 3 X 10(6) daltons, unrelated in sequence to M, S1, or S3. S1, S3, and M had a 3' T1 dodecanucleotide in common.


Effect of RNase III on the size of bacteriophage T7 lysozyme mRNA.

The size of lysozyme mRNA from T7-infected E. coli RNase III+ and RNase III- strains was analyzed by sucrose gradient sedimentation, dimethylsulfoxide (Me2SO) sucorse gradient sedimentation, and preparative gel electrophoresis. Each technique revealed a similar size distribution of multiple lysozyme mRNA's. Analysis by preparative gel electrophoresis of RNA extracted after infection of Escherichia coli Bst (RNase III+) separated lysozyme mRNA into six peaks of activity ranging in size from 0.2 x 10(6) to 1.9 x 10(6) daltons. Four well-resolved major peaks of activity were detected, having apparent molecular weights of approximately 0.61 x 10(6), 0.76 x 10(6), 0.92 x 10(6), and 1.3 x 10(6). A broad band of activity, with a molecular weight range from 0.2 x 10(6) to 0.37 x 10(6), was also present, and a sixth peak of activity was sometimes observed that migrates with a mobility corresponding to a molecular weight of 1.9 x 10(6). Judging from their molecular weight as estimated by electrophoresis, most, if not all, of the lysozyme mRNA's were polycistronic. The RNA extracted after infection of an RNase III- host contained a more heterogeneous collection of lysozyme mRNA's. In addition to lysozyme mRNA activity on RNAs with molecular weights between 0.2 x 10(6) and 1.9 x 10(6), RNA species with molecular weights estimated at 4 x 10(6) to 5 x 10(6) were also detected. The data indicate that RNase III processes at least some of the primary lysozyme transcripts. The multiple lysozyme mRNA's represent discrete RNA species rather than aggregates because analysis of the size of lysozyme mRNA under completely denaturing conditions, in Me2SO, produced a similar size distribution of lysozyme mRNAs. Also, treatment of RNA with 90% Me2SO, which separates the strands of a completely double-stranded RNA, did not significantly alter the electrophoretic mobility of the lysozyme mRNA.


Effect of RNase III on efficiency of translation of bacteriophage T7 lysozyme mRNA.

RNase III had no positive effect on the translation of bacteriophage T7 lysozyme mRNA in vivo or in vitro. The time of appearance and quanity of lysozyme in T7-infected E. coli BL107, an RNase III- strain, and T7-infected E. coli BL15, a nearly isogenic RNase III+ strain, were indistinguishable. Nearly identical patterns of lysozyme mRNA activity were obtained when RNA extracted at different times after infection of RNase III+ and RNase III- hosts was translated in cell-free extracts of E. coli containing or lacking RNase III. Exposure of RNA extracted from T7-infected E. coli BL107 (RNase III-) to purified RNase III did not increase the lysozyme mRNA activity of this RNA. The only result that implied that RNase III has a differential effect on the translatability of the lysozyme mRNA was the translation of fractionaed RNA from T7-infected E. coli BL107. Translation of the smallest and largest lysozyme messages, 0.33 x 10(6) and 4 x 10(6) to 5 x 10(6) daltons, was the most inefficient in RNase III- cell-free extracts as compared to RNase III+ cell-free translation. The translation of the most abundant, medium-sized lysozyme mRNA between 0.9 x 10(6) and 1.5 x 10(6) daltons was the least affected by the absence of RNase III. The existence of a lag between the appearance of lysozyme mRNA and the appearance of lysozyme in T7 infection was confirmed. In these studies a very rapid method of RNA extraction was used, eliminating the possibility of continued RNA transcription during cell collection and RNA extraction. With this method of analysis, the length of the lag period was established at about 3 min. The possibility that RNase III is the controlling element of the lag period was eliminated by these investigations.


S-adenosyl-L-homocysteine as a stimulator of viral RNA synthesis by two distinct cytoplasmic polyhedrosis viruses.

An in vitro RNA-synthesizing system was used to study the effects of S-adenosyl-L-homocysteine, S-adenosyl-L-methionine, and adenosine on the methylation and synthesis of single-stranded RNA by two different cytoplasmic polyhedrosis viruses.


Azathioprine-induced pure red blood cell aplasia.

Pure RBC aplasia developed in two renal transplant recipients who were receiving long-term azathioprine therapy. With substitution of cyclophosphamide therapy for azathioprine, erythroid hyperplasia and reticulocytosis developed at three weeks in one patient and at three months in the other. Selective erythroid toxic reaction is a potential problem that must be considered when anemia develops in patients receiving long-term azathioprine therapy.


Malignant neoplasms following cardiac transplantation.

Between Jan 6, 1968, and April 11, 1977, 124 patients underwent cardiac transplantation at Stanford University Medical Center, with a mean and median period of follow-up of 18.3 and 9.7 months, respectively. Malignant neoplasms developed in seven patients--three lymphoproliferative neoplasms, two skin cancers, one acute leukemia, and one colon carcinoma. Visceral tumors were often fatal and caused 11% of deaths after three months following transplantation. The incidence and spectrum of malignant neoplasms in this population are similar to those observed in recipients of renal homografts.


Pathogenicity of cultivated murine leprosy bacilli Hawaiian-Ogawa strain in mice. 1. The pathogenicity of bacilli from rough colonies.

This paper deals with the pathogenicity of cultivated murine leprosy bacilli from rough colonies of Hawaiian-Ogawa strain in mice. This strain was isolated by Ogawa, in 1970, on Ogawa's 1% egg yolk medium [1], from mice previously inoculated with Hawaiian strain of murine leprosy bacilli which has been maintained by passages from mice to mice. The pathogenicity of Hawaiian-Ogawa strain was found to belong to the same pattern as Hawaiian strain when the subcutaneous inoculation test was carried out in C57BL/6 and C3H mice, the former being representative of the benign type and the latter being representative of the malignant type. In KK mice of the intermediate type with Hawaiian bacilli, however, Hawaiian-Ogawa bacilli produced the lesions with malignant features in almost all the male mice, while the female mice were divided into two groups roughly half showing the intermediate or malignant type. In DDD mice of the benign type with Hawaiian bacilli, some cases of the male mice showed the malignant features, whereas almost all the female mice were of the benign type in the same experimental conditions. The pathogenicity of Hawaiian-Ogawa bacilli in mice did not revert into that of Hawaiian bacilli even after serial mouse passage. There are slight but definite differences in the mouse pathogenicity between Hawaiian-Ogawa and Hawaiian strains.


Mode of immunopotentiating action of BCG: macrophage activation produced by BCG-infection.

Macrophage activation as measured by increased rate of carbon clearance and spreading of peritoneal macrophage was studied in mice infected with BCG, strain Japan. BCG caused marked increase of the numbers of peritoneal cells and spread macrophages. The increases of spread macrophages reached a peak at the 3rd week of BCG infection introduced by the both routes of intravenous(i.v.) injection and foot pad(f.p.) injection. BCG also enhanced the clearance of carbon. In the case of BCG given i.v., the increase of the rate of carbon clearance was biphasic : an early increase reaching maximum at the 1st week and a late increase reaching maximum at the 3rd week of BCG infection. When BCG given into one foot pad, peak increase was reached at the 5th week. The activation of macrophages as measured by increased levels of carbon clearance and increased numbers of spread macrophages in the mice receiving BCG i.v. was approximately two fold greater than that in the mice receiving BCG by f.p. route. When sheep red blood cells (SRBC) as antigen were injected i.v. into the mice primed with BCG i.v., the optimal interval between BCG priming and subsequent antigen injection varied with the dose of antigen for the induction of the highest level of delayed type hypersensitivity (DTH) to SRBC, but not with the degree of macrophage activation.


[Various factors influencing toxicity and metabolism of metals--metal-metal interactions and host factors (author's transl)].

This paper is a brief overview on metal-metal interactions and various other factors involved in the toxicity and metabolism of metals, including host factors, nutrition, habits, etc. Humans and other organisms are exposed to various metals in many ways, and even in an occupation in which workers are exposed to a metal such as lead, they are at the same time also exposed to other metals, although concentrations of these latter metals are usually not very high. This can result in effects different from those produced by a single metal by itself. Furthermore, individual differences which are caused by genetic, nutritional, hormonal, habitual, and many other factors may alter the toxic or metabolic effects of a single metal. Information on this subject is rather limited. This paper is a brief introduction to the importance of future studies on the topic, and the author hopes that it will stimulate more studies by those who are interested in the field of metal toxicology.


[Hazards and complications of temporary endocardial stimulation].

In conducting 381 stimulations in 330 patients with brady- and tachysystolic disorders of cardiac rhythm of various etiology 122 complications were revealed. Dislocation of the electrode was noted in 71 cases (18.6%), perforation of the myocardium by the endocardial electrode in 9 (2.1%), ventricular fibrillation in 11 (2.3%), and sepsis in 5 (1.3%) of the cases. A special device may be used for the immediate detection of dislocation. Characteristic changes are noted on the intracardiac ECG in penetration of the electrode into the myocardium (precursor of perforation).


[Study of hemodynamics in patients with acromegaly by means of radiocardiography].

Determination of the indices of central hemodynamics by means of radiocardiography shows them to be essentially changed in patients with acromegaly in the active stage. A clear correlative relationship has been established between the shifts in hemodynamics and the heart volume determined by X-ray. The diagnosis of preclinical stage of circulatory insufficiency is based on revealing a statistically significant increase in the stroke index and a decrease in the circulation volume and total peripheral resistance. In the early stage of acromegaly there is a statistically significant increase in the minute and stroke indices, in the index of minute work, and in the coefficient of circulation effectiveness. With an increase in the duration of the disease, these indices decrease considerably, which denotes hemodynamics deterioration.


[Coronary insufficiency in panarteritis].

Thirty patients with panarteritis of the aorta and its branches were investigated. The disease was verified by aortography, coronarography and autopsy data. On third of the patients had no clinical signs of the lesions of the coronary arteries, and ECG did not show myocardial hypertrophy. Coronaroangiography demonstrated lesions of the openings of the major coronary arteries by the type of the "burnt tree". Morphological picture and localization of the lesions were typical for the disease.


[Use of the preparation Essenciale in chronic ischemic heart disease].

The efficacy of the drug "essentiale" is discussed on the basis of observation over 34 patients suffering from ischemic heart disease with functional hepatic insufficiency and types IIa and IIb hyperlipoproteinemia. Its normalizing effect on the indices of lipid metabolism the flow of blood in the leg and foot, the vascular tone, and liver function is shwon.


[In memory of Albrecht von Graefe's 150th birthday (author's transl)].

On the occasion of the 150th aniversary of Albrecht von Graefe's birthday his short but successful activity for ophthalmology is brought back to mind. Within the scape of his life-history the attempt is made to portray a man in his time and to waken his importance as ophthalmologist a significant still in our days.


[Perforating monolateral autokeratoplasty (author's transl)].

The author describes his own techniques of perforating monolateral autokeratoplasty, using two trephines of the same diameter, one of them turning with the right, the other with the left hand. To prevent loss of aqueous humor at first the one and then the other trephine is used up to half the thickness of the cornea. Then the central disc is excised, but to close the hole the trephine left in place until after the finishing of trephining the peripheral disc. The peripheral clear graft is sutured into the central hole, and the central clouded graft is sutured into the peripheral hole. The cornea is overlapped with a conjunctival flap. The diameter of the trephine may be 3 or 4 mm. In total we performed 24 perforating monolateral autokeratoplasties. In 13 the graft remained clear, in 9 they became semitransparent and in two cases they became clouded. In 20 patients the visual acuity improved, in 4 patients no change could be attained. In case of a clear healing the picture of the cornea is characteristic: in the dim center a clear disc and in the periphery - at most in the upper part - the dim graft from the leukoma.


[Lethal achondrogenesis: a review of 56 cases (author's transl)].

54 cases with lethal achondrogenesis from the literature as well as two own cases are reviewed and analyzed with regard to the following characteristics: sex, hydramnios, breech presentation, duration of pregnancy, length and weight at birth, head circumference, length of upper and lower extremities, clinical and radiological data, age of mother and father at time of birth, familial occurrence and consanguinity of parents, histological, histochemical and electronmicroscopic tissue examination.


[The variation of 16 serum protein fractions following renal transplantation (author's transl)].

We have investigated 16 serum proteins in 20 patients with stable renal function after renal transplantation. Our investigations have shown the following substantial findings: a regular increase of prealbumin, alpha1-glycoprotein, haptoglobin, hemopexin and beta2-glycoprotein, as well as a rather frequent increase of alpha 2-macroglobulin. As far as variations of the serum protein levels are concerned there was no correlation with kidney disease, accompanying illnesses, therapy or interval since transplantation.


A modified india-ink immunoreaction for the detection of encephalitozoonosis.

A modified india-ink immuno technique is described. The use of a moist chamber is not required and the visualisation of both positive and negative results facilitates more rapid and confident reading of the test.


Renal transplantation in the rabbit: a model for preservation studies.

Transplantation is necessary for evaluation of kidney preservation procedures, and a model using a small laboratory animal is desirable. The rabbit was found to be a suitable animal for this purpose. Even long periods of anaesthesia without artificial respiration were safely achieved. Hydration and serum electrolytes could be maintained within normal ranges with intravenous injections of isotonic saline and dextrose during and after the operation. The kidneys were implanted by anastomosing the artery and vein end-to-side to the abdominal aorta and the posterior vena cava respectively. The ureter was implanted into the bladder over a nylon stent. In a recent 100 transplantations the incidence of vascular thrombosis was low (4%), but rather more (10%) mainly late ureteral complications were encountered. Transplanted kidneys showed good function with mean peak serum creatinines of 285 mumol/l and normal macroscopic and histological appearance at autopsy.


Growth of the ICRC bacilli in the foot-pad of mice.

The ICRC bacilli are acid-fast bacilli cultivated from M. leprae isolates of lepromatous tissue. The ICRC bacilli from C-44 in the conditioned medium were subjected to foot-pad test, in both normal and T/900r mice. The bacilli exhibits a limited multiplication in normal mice while a continuous growth in T/900r mice. The maximum yield for normal and T/900r mice was 10(7) and 10(9)/foot-pad, respectively. The infiltration of voluntary muscle tissue as the main localization site was common for both normal and T/900r mice with evidence of dissemination in the latter. The spread of AFB to sciatic nerve, induction of liver granuloma and the foot-drop was observed only in T/900r mice. These experiments show that the growth of ICRC bacilli in mouse foot-pad is very similar to that of M. leprae confirming a test for identification.


Disulfiram implantation. A placebo-controlled trial with two-year follow-up.

Ten alcoholics implanted with disulfiram had longer periods of abstinence after treatment than did 10 alcoholics implanted with placebo; 7 of the disulfiram-implanted patients experienced a disulfiram-ethanol reaction in uncontrolled drinking situations, while none of the placebo-implanted patients did.


Experience with lymphangioma.

Lymphangioma is a rare and benign tumor, mostly encountered in childhood. Our experience extends to 21 patients, all of which were operated upon. Early radical excision in moderate forms or cervical locations and delayed excision or combined management in complex cervical forms are the more preferable way of treatment.


IgG in the walls of the post-capillary venules of human lymph nodes.

IgG immunoglobulin was demonstrated in the wall of the post-capillary venules of human para-aortal lymph nodes by using a direct immunoperoxidase technique. The relationship of this immunoglobulin to the recirculation of the small lymphocytes is discussed.


The ontogenic characteristics of lactate dehydrogenase isozymes in mammaliam pre-implantation ova.

The onotgenic characteristics of lactate dehydrogenase (LDH) isozymes in mammalian pre-implantation ova have been reviewed. Evidence has been provided that the ova of mice and other mammalian species contain enzyme activity in a masked form, and display turnover processes which possess distinctive characteristics by comparison with those in adult tissues. Also, the extraordinary high levels of LDH in the extracellular secretion of the mammaliam oviduct have been commented on, along with the influence of reproductive hormones on the activity and type of this enzyme. In addition, attention has been drawn to the unique characteristics of the oval micro-evironment, and the influence which such factors may exert on the realization of enzyme phenotype during early mammalian development.


Electronic processing of cardiac rehabilitation data.

With the incidence of ischaemic heart disease at epidemic levels and rising, techniques for detecting, predicting, and rehabilitating the condition of cardiac dysfunction are constantly under development. One technique, that of exercise stress testing, has been used in recent decades in the prediction, detection, and rehabilitation of cardiopulmonary disease. However, ergometric studies in this regard have been hampered by the tedium of physiologic data collection and analysis. With the advent of automated digital and analogue computation procedures and equipment, such data can be both operated on real-time for immediate display or stored for post-exercise and patient-history studies. Such automated data manipulation provides an systematic and comprehensive testing of each patient and permits a much greater case-load. In addition, special computer programs can compile and index specific parameters from a large sample size to facilitate statistical surveys of selected patient populations. The results of such statistical analyses can, if desired, be automatically printed out in a graphical form.


[Comparative study on single layer and two layer anastomoses of small intestine (author's transl)].

The one layer anastomosis after Gambee is compared with the two layer anastomosis after Dick at the small bowel of 20 minipigs. The end-to-end anastomosis after Gambee consists of an interrupted, inverting suturing of the bowel wall. Dick suggested a closed method, applying bronchial clamps before resecting the bowel. Seromuscular sutures and inner all layer sutures are inserted interrupted. Experimental studies have been done after 4, 7, 14 and 21 days. In Histology two layer anastomoses caused delayed wound healing after 4 days. Twenty-one days after the operation histological findings in both groups were equal. Microangiographic studies showed, that in single layer anastomoses revascularization began 3 days earlier than in two layer anastomoses. Measuring of the bursting strength showed no significant differences. All parameters suggest equal value of both techniques. In our opinion the two layer anastomosis after Dick combines the advantages of a closed method with a simple, easy performable technique. We therfore apply it all over the gastrointestinal tract with exception of esophagel and rectal anastomoses.


A case against nasal packing.

Nasal packing is included in most technical descriptions of septal and rhinoplasty surgery with little accompanying discussion of its indications and possible pitfalls. We believe that routine nasal packing is not an innocuous step. There are certain specific indications for its use but these are uncommon. We suggest that exclusion of packing is a wiser alternative in routine procedures. Over 800 cases of nasal surgery have been reviewed with fewer than 9% requiring packing. The indications for such packing are described as are the alternatives. Problems and complications attendant with its routine use are explored.


Immediate local tissue reactions to Teflon vocal cord implants.

From the beginning of the teflon injection technique for paralyzed vocal cords there has been an obvious interest in its role as a foreign body. There are a number of previous reports after varying periods of time of residence. This case report describes the tissues response of the foreign body reaction very early, 48 hours after the injection of teflon. It is consistent with early inflammatory foreign body reaction.


Glycyrrhiza in old and new perspectives.

A chronological, documented summary of the reputed uses of glycyrrhiza since 2100 B.C. to the present with correlations made to modern pharmacological research. Many early claims for a broad spectrum of uses for this drug appear to be borne out by conclusions from modern research.


Development and standardization of a cytotoxic micro-assay for detection of enterotoxins: survey of enterotoxins from Escherichia coli of infant origin.

The development of a practical cytotoxic micro-assay for detection of enterotoxins in crude bacterial lysates of E. coli and other Gram-negative bacteria, is described. This quantitative assay is based on growth inhibition of mouse-fibroblasts, maintained in suspension or by inhibition of uptake of DNA precursors. Guidelines for performing the assay and evaluating the results by statistical considerations, are described. The choice of a relatively cheap medium and a suitable number of target cells to achieve cell doubling in 24 h is given. The concentrations of proteins in the crude lysates from strains of different origin, are not of equal potency; a predetermined but different protein concentration for strains from infants, adults or porcine origin, are recommended for detection of the toxins and for achieving reproducible results. Production of toxic proteins is enhanced by mitomycin C in toxigenic strains and not in non-toxigenic strains. Screening of a limited number of lysates from E. coli strains originating from infants and a comparison of the cytotoxicity of several known toxigenic and non-toxigenic strains from human adults and porcine origin, are presented.


[2,4,6-trinitrotoluene as a nutritional source for bacteria].

2,4,6-Trinitrotoluene (TNT) is one of the most stable toxic substances belonging to nitroaryls which is introduced into water reservoirs with industrial wastes. Its metabolism by microorganisms was studied in this work. The nitrogen of TNT is less accessible for Pseudomonas denitrificans than for Escherichia coli. In the latter case, TNT can be compared with ammonium sulphate. As a source of carbon, TNT is not utilized at all by E. coli and is hardly accessible for Ps. denitrificans. The data obtained in this work are valuable for intensifying the decomposition of TNT in natural and waste waters. This process can be stimulated in the conditions of biological purification of waters by combining waste waters containing TNT with other industrial waters containing accessible organic substances.


Laboratory support in the management of syphilis.

Recent developments in syphilis serology are set down. The approach today is more rational as it has some basis in immunological understandings. In spite of improvements, syphilis serology continues to have limitations, and differentiating active from inactive cases remains taxing. In primary and secondary syphilis, dark-ground microscopy is still the quickest and surest way to make the diagnosis. In latent syphilis and in late and congenital cases, as well as in instances of other treponemal infections, serological evidence of disease needs to be considered along with each patient's medical, social and sexual history, when and why they may have been given antibiotic treatment, and the results of radiological studies and cerebrospinal fluid examination. For some syphilitics, the decision to treat or not to treat remains a matter of art rather than science.


[Effect of glutamic acid on Saccharomyces cerevisiae cell permeability during rehydration after dehydration].

Losses of potassium ions, nucleotides and protein substances were studied upon rehydration of Saccharomyces cerevisiae cells grown on a defined nutrient medium with ethanol and glutamic acid (0.075%) and subjected to dehydration. Considerable amounts of K+ (75--82% of the total), nucleotides and protein substances were found to be released into distilled water upon rehydration of the dehydrated yeast cells. If a higher percentage of yeast cells survived, these lost less nucleotides and nitrogen-containing substances. Glutamic acid being added to the growth medium did not decrease specifically the permeability of the dehydrated yeast cells upon rehydration.


[Effect of low temperatures (-196 degrees) and of cryoprotectors on some bacterial species].

The effect of low temperatures (-196 degrees C) and cryoprotectors (PEO-400 and glycerol) on the survival, morphological and functional properties was studied with Escherichia coli, Serratia marcescens and Staphylococcus aureus 209. When the cells were frozen for a short period of time in liquid nitrogen, the survival and the rate of protein synthesis decreased in the gram-negative bacteria but remained almost the same in Staphylococcus aureus. PEO-400 and glycerol manifested cryoprotecting action on all the bacteria under study at concentrations which did not harm the bacteria.


The medical philosophy of Francis Bacon (1561-1626).

Francis Bacon's view of man is dualistic but, although he takes note of mental faculties, he makes the relation between mind and body, rather than the substance of mind, the basis for enquiry into mental processes and, more particularly, for the medically relevant study of mind. (He uses "mind" and "soul" as equivalent terms.) The healing of the body requires study of the body, and the ineffectiveness of physicians is due to their failure in this respect rather than to the body's complexity. To learn about the body requires clinical observation and recording, together with the comparison of bodies, experiments on living animals and attention to pathological changes. The aims of medicine should include not only the restoration of health but also the relief of suffering and they are not to be limited by putting aside a disease as incurable. To learn from treatment it must be fixed in its ordering with controlled and limited variation. Bacon has no separation of medicine from natural science; his philosophy of medicine is his general philosophy of the advancement of knowledge, but limited to a particular field of application. If medicine is separated from natural philosophy it is changed wholly or greatly into empiricism.


A comparison between spironolactone and hydrochlorothiazide with and without alpha-methyldopa in the treatment of hypertension.

In a single blind crossover trial, spironolactone (50 mg twice a day), and hydrochlorothiazide (50 mg twice a day) were equally effective hypotensive agents in 16 patients with untreated essential hypertension. The addition of alpha-methyldopa (250 mg three times a day) to each agent produced a further significant and equal fall in blood pressure. Spironolactone therapy was assoicated with fewer clinical and biochemical side effects. The hypotensive effect of the diuretics was independent of the renin status of the patients.


[Stenoptin in angina pectoris (author's transl)].

In a placebo-controlled double blind study 20 patients suffering from angina pectoris were treated with Stenoptin. The patients had 5 attacks at least per week and consumed 5 chwable nitrocapsules and more. Criteria of success were consumption of chewable nitrocapsules and frequency of attacks. During a 7 day preobservation period the patients received a placebo identical with Stenoptin and 20 chewable nitrocapsules. The study lasted for 8 weeks. The dose was 1 tablet 3 times per day. The attacks of the active substance group were reduced from 11 to 2 on the average, and the nitro-consumption from 16 to 2 per week. In the placebo group frequency of attack slightly increased from 10 to 11. In the active substance group the dose could be reduced to 1 tablet twice per day. The placebo group was treated with 1 Stenoptin tablet 3 times per day for another 8 weeks. Subsequently 1 tablet twice per day sufficed. Transient, nitro-induced headache occurred only in 3 test persons. Stenoptin did not cause side effects and was very effective in serious types of angina pectoris.


[Results of a double blind study on the effect of silymarin in the treatment of acute viral hepatitis, carried out at two medical centres (author's transl)].

In a double blind study carried out under standard conditions at two treatment centers silymarin, 2 sugar-coated tablets 70 mg three times daily, showed a definite therapeutic influence on the characteristic increased serum levels of bilirubin, GOT and GPT associated with acute viral hepatitis. The above mentioned values in 28 patients treated with silymarin were compared with those in 29 patients treated with placebo. The laboratory parameters in the silymarin group regressed more than in the placebo group after the 5th day of treatment. The number of patients having attained normal values after 3 weeks' treatment was higher in the silymarin group than in the placebo group. A statistical comparison revealed a difference between bilirubin and GOT values in the placebo and silymarin groups and a definite trend in the regression of GPT values in favour of silymarin. The course of the immune reaction in HBS Ag patients was not influenced by silymarin. As already proved by other investigators, the use of silymarin in acute viral hepatitis can lead to an accelerated regression in pathological values, thus indicating its use in the treatment of this liver disease.


The cervical lymph nodes in Streptococcus pyogenes, group A, type 50, infection in mice.

Streptococcus pyogenes, group A, type 50, one of the few group A streptococcal types naturally occuring in mice, proved highly virulent in this species after experimental infection. Intranasal infection of 96 mice (Swiss albino, NMRI, and CBA) with this microorganism induced profound reactions in the cervical lymph nodes of 69% of the animals. Histologically, two different forms of reaction were distinguishable. In 61 mice, the lymph nodes exhibited follicular and lymphoplasmacellular hyperplasia and in 9 animals suppurative lymphadenitis was present. The ability of type 50 streptococci to persist in the pharynx of mice, and the similarity of the morphological changes induced by this organism appear to make intranasal murine group A, type 50, streptococcal infection a suitable model for human streptococcal pharyngitis.


Identification of Escherichia coli and Bacillus stearothermophilus ribosomal protein binding sites on Escherichia coli 5S RNA.

E coli [32P]-labelled 5S RNA was complexed with E. coli and B. stearothermophilus 50S ribosomal proteins. Limited T1 Rnase digestion of each complex yielded three major fragments which were analysed for their sequences and rebinding of proteins. The primary binding sites for the E. coli binding proteins were determined to be sequences 18 to 57 for E-L5, 58 to 100 for E-L18 and 101 to 116 for E-L25. Rebinding experiments of purified E. coli proteins to the 5S RNA fragments led to the conclusion that E-L5 and E-L25 have secondary binding sites in the section 58 to 100, the primary binding site for E-L18. Since B. stearothermophilus proteins B-L5 and BL22 were found to interact with sequences 18 to 57 to 100 it was established that the thermophile proteins recognize and interact with RNA sequences similar to those of E. coli. Comparison of the E. coli 5S RNA sequence with those of other prokaryotic 5S RNAs reveals that the ribosomal proteins interact with the most conserved sections of the RNA.


Origin of replication, oriC, or the Escherichia coli chromosome on specialized transducing phages lambda asn.

Specialized transducing phages lambda asn harboring chromosomal DNA and genetic markers on either side of the asn gene were isolated. Phages carrying chromosomal DNA counterclockwise of the asn gene can upon infection establish themselves as self-replicating plasmids in asn, recA hosts lysogenic for lambda. It is concluded that this bypassing of normal lambda immunity is due to the presence of the chromosomal replication origin, oriC, in this class of phages. Genetic analysis and the determination of restriction endonuclease cleavage patterns of the different lambda asn lead to the allocation of oriC within 1.5 megadaltons of the asn gene towards the uncA, uncB genes at 82 min on the genetic map of E. coli. The clockwise order of genes on the chromosomes is found to be: bglB, (pst, glmS), (uncA, uncB), oriC, asn, trkD, rbs, rrnC, ilv.


Ability of chloramphenicol to suppress phenotypically some bacterial mutations.

Chloramphenicol (CLP) at slightly inhibitory concentrations (3-5 microgram/ml) suppresses the inhibition of DNA synthesis and cell division caused by the temperature sensitive mutation dnaE486 at the nonpermissive temperature. Some other mutations can also be phenotypically suppressed by CLP. A similar effect is shown by chlortetracycline. Phenotypic suppression is caused by both these drugs in different cases than by streptomycin.


E. coli K-12 pel mutants, which block phage lambda DNA injection, coincide with ptsM, which determines a component of a sugar transport system.

Escherichia coli pel- mutants inhibit the penetration of bacteriophage lambda DNA into the cell. Using P1 mediated cotransduction, we mapped pel- mutations between markers fadD and eda in the interval of minute 40 of the revised E. coli K-12 map. This places pel in the same region as genes kdgR and ptsM. Mutations in kdgR usually do not alter the Pel phenotype, and vice versa. In contrast, about 30% of ptsM- mutants are also pel-, and all pel- mutants isolated are ptsM-. These results suggest that pel and ptsM are one and the same gene. This interpretation would identify the bacterial product required for injection of phage lambda DNA as a component of the phosphoenolpyruvate-dependent phosphotransferase system specific for mannose, glucosamine, glucose and fructose. However, the experimental results do not exclude an alternative explanation: that pel and ptsM identify two closely linked genes which would be simultaneously affected at high frequency by a particular mutational event.


The temperature sensitive mutant 72c. II. Accumulation at high temperature of ppGpp and pppGpp in the presence of protein synthesis.

A heat sensitive mutant of E. coli has been analyzed. A shift to restrictive temperature leads to an accumulation of ppGpp and pppGpp in both the parental and the mutant strains (both are relA+). The pool of these compounds is shown to decrease with time after the temperature shift in the case of the parental strain, but remains at the same elevated level in the case of the mutant. The temperature shift of the mutant leads to an apparent reduction of stable RNA synthesis; this inhibition can be released by chloroamphenicol or tetracycline. Gross protein synthesis is more or less unaffected at restrictive temperature. In the parental strain little effect is seen on RNA and protein synthesis after the temperature shift. A relA derivative of the mutant does not show the same inhibition of RNA synthesis at high temperature. Sedimentation analysis suggests that mutant 70S ribosome are more stable, when exposed to a lowered Mg2+ concentration, than are 70S ribosomes from the parental strain. In addition, the relative amounts of the two forms of ribosomal protein S6, which can be obtained on DEAE chromatography (Held et al., 1973), are significantly changed in the mutant.


Regulation of surface antigens expression in Paramecium primaurelia: genetic and physiological factors involved in allelic exclusion.

In paramecium aurelia, allelic exclusion can be considered as a basic feature of the surface antigens system in the same way as intergenic exclusion. Our studies on allelic exclusion in G156/G168 heterozygotes show that (1) allelic exclusion does not depend on discrete regulatory genes dispersed throughout the genome; (2) it does not seem to be influenced by cytoplasmic factors; (3) it occurs regardless of the surface antigen expressed by the parental strains at the time of the cross. These results are discussed in relation to both intergenic and interallelic exclusion for which a common basis is proposed.


Release of nascent trp mRNA from the operon DNA in chloramphenicol-treated cells of Escherichia coli.

When transcription of the E. coli trp operon is blocked as a result of inhibition of ribosomal activities by chloramphenicol, nascent trp mRNA but not RNA polymerase molecules seem to detach from the template DNA. The continued association of RNA polymerase with DNA is inferred because RNA synthesis resumes at or near the sites of transcription blockage after removal of the antibiotic. When E. coli cells infected with lambdatrp phage are incubated with chloramphenicol under the "Ptrp-promoted" conditions (Imamoto and Tani, 1972; Segawa and Imamoto, 1974), the trp mRNA molecules synthesized after removal of the antibiotic contain only promoter-distal information. They are usually small in size, in spite of the fact that chloramphenicol inhibition does not lead to the degradation of trp mRNA. On the other hand, PL-promoted trp transcription, which is non-polar and insensitive to chloramphenicol action, does not show such a premature release of nascent trp mRNA in chloramphenicol-treated cells.


Incompatibility and transforming efficiency of ColE1 and related plasmids.

Replicons derived from the ColE1 plasmid are incompatible with one another, but are compatible with their naturally occurring relatives ColK and CloDF13. The incompatibility results in loss, by segregation, of one or the other ColE1 plasmid. In most cases, the smaller derivatives tend to displace the larger ones, and the rate of displacement depends on the difference in size. One mini-plasmid retains only 19% of the sequences of ColE1, yet it exerts strong incompatibility: other ColE1 plasmids are rapidly lost when it is introduced into the host. The region essential for ColE1 incompatibility is deduced to lie within 700 base pairs of the origin of replication. The transforming efficiency of any ColE1 plasmid is markedly lowered when another incompatible replicon is resident in the competent cells, even when the transforming plasmid is much smaller than the resident. A model of incompatibility is proposed to account for these effects.


Multiple independent control mechanisms affecting the acetamidase of Aspergillus nidulans.

The acetamidase of Aspergillus nidulans is induced by sources of acetyl CoA, benzoate and benzamide and by beta-alanine and other omega-amino acids. The effects of these groups of inducers are appromimately additive. The cis-acting control site mutant, amdI9, affects induction by sources of acetyl-CoA specifically. Lesions in the amdR and gatA genes affect induction by omega-amino acids specifically. Mutations in the amdA gene can lead to elevated acetamidase levels which still respond to the various inducers. The induction controls act independently of repression control by nitrogen metabolites and are not altered by the areA102 mutation. The properties of double mutants with lesions affecting the different control mechanisms also indicate their independence of each other. It is suggested that the acetamidase is subject to complex control by multiple regulatory circuits and that functionally independent control sites adjacent to the structural gene occur.


Mutations determining generalized resistance to aminoglycoside antibiotics in Escherichia coli.

Mutations conferring resistance to low levels of kanamycin in Escherichia coli have been mapped at 3 locations: the unc locus (min. 83), a locus we have designated kanA (MIN. 72), close to strA (rpsL), and a locus at min. 86.5 previously discovered by Plate (1976) that we have designated ecfB. The unc and ecfB mutations are associated with defects in energy metabolism, while mutations at kanA may be in the gene coding for ribosomal protein S12 (rpsL). The three types of mutations cause cross resistance to a number of different aminoglycoside antibiotics and the effects of the mutations are cumulative in combination.


The temperature sensitive mutant 72c. I. Pleiotropic growth behaviour and changed response to some antibiotics and mutations in the transcription or translation apparatus.

The spontaneous temperature sensitive mutant 72c is shown to be more tolerant to fusidic acid, but less tolerant to trimethoprim on plates at permissive temperature, than is the parental strain. The poor growth of the mutant on amino acids supplemented plates, as well as its inability to grow on broth plates at 40 degrees, can be compensates by sublethal amounts of chloroamphenicol. Also some mutations to Rif-R or Str-R improve growth of the mutant under certain conditions. Reversion and other genetic analysis strongly suggest, that the pleiotropic behaviour of the mutant is due to a single mutation in a gene, which is designated fusB and is closely cotransducible with lip at min 14 of the E. coli chromosome. The gene order is lip-fusB-supE.


On the formation of rho - petites in yeast. III. Effects of temperature on transmission and recombination of mitochondrial markers and on rho - cell formation in temperature sensitive mutants of Saccharomyces cerevisiae.

The rho-factor stability is shown to be affected by four conditional mutations, tsm-8 (mitochondrial), tsp-20, tsp-25 and tsp-30 (nuclear). Growth of mutant cells at high temperature (35 degrees C) results in the rapid production of rho - cells and concomittantly in the decrease of the ability to transmit mitochondrial genetic information to the rho + progeny of crosses. Kinetics of rho - cell formation during growth at 35 degrees C have been compared with variations in transmission and recombination of mitochondrial markers in crosses. In all cases the transmission of mitochondrial markers of the ts-parent decreases as the number of cell generations increases. The frequencies of recombinants between mitochondrial markers either increase or decrease depending on the markers considered and the alleles of the omega-locus involved in the crosses. The results of all crosses performed have been compared with the predictions of the model for recombination and segregation of mitochondrial genes proposed by Dujon et al. (1974). This comparison indicates that the main result of high temperature treatment is a diminution of the input of mitochondrial information from the ts-parent into zygotes. Consequences of the induced variations of input follow the predictions of the model. The correlation found in ts-strains between the reduction of input in crosses and the formation of rho - cells is discussed in terms of molecular events occurring in mitDNA molecules during high temperature induction of rho + to rho - mutation.


Studies on the control region of the bipolar argECBH operon of Escherichia coli. I. Effect of regulatory mutations and IS2 insertions.

Several mutations affecting the control or the potential of gene expression in the argECBH bipolar operon have been characterized by enzyme assays, genetic mapping, dominance tests and pulse labelled RNA determinations. None of the mutations involves DNA rearrangements detectable by heteroduplex analysis (Charlier et al., 1978). Partially constitutive transcription of both argE and argCBH has been observed in mutant L10 while constitutive argE transcription and normal argCBH control characterize mutants L9, LL13 and LL2. The control region thus appears to contain two overlapping operators, as suggested previously (Elseviers et al., 1972). Two mutants (L2, LL1) and strain 6-8 from Bretscher and Baumberg (1976) display an increase in acetylornithinase specific activity (argE product) without concommittant increased argE transcription. In addition, they exhibit a decreased argCBH transcription. It is suggested that in these organisms, argE translation and argCBH transcription may be affected by the same genetic event; this explanation is compatible with present working hypothesis for the structure of the control region. An interpretation in terms of messenger attenuation also appears possible. From the properties of two strains harbouring an IS2 insertion in the control region (Charlier et al., 1978) the following conclusion may be drawn: 1. When inserted in orientation I close to the proximal end of a silent gene IS2 appears to promote a low but detectable transcription readthrough into that gene. 2. Insertion of an IS2 element in orientation II close to a neighbouring gene is not a sufficient condition to express that gene at a high rate. The properties of the two insertions appear compatible with the structure proposed for the control region.


The activity of ant product of the Salmonella phage P22 against the closely related but heteroimmune phage L.

P22 mutants defective in the early gene 24 are complemented by phage L in mixed infection. P22 12- and P22 23- mutants are not complemented by phage L. Gene function 24 of an L prophage is turned on by a superinfecting P22 24- mutant and complements the missing function of the defective P22 phage. Since this transactivation of prophage gene 24 depends on a functional gene ant in the superinfecting P22 mutant, it indicates derepression for leftward directed gene expression in prophage L. On the contrary neither the rightward directed expression of gene 12 nor of gene 23 in prophage L. can be turned on by superinfecting P22 24- 12- or P22 24- 23- mutants (and also not by P22 12- and P22 23-) to a degree sufficient for complementation of simultaneously superinfecting L virB 12- or L virB 23- mutants. The failure to detect release of repression for rightward directed gene expression of prophage L corresponds to the earlier observation (Prell, 1975) that P22 superinfecting L lysogens cannot release replication inhibition for simultaneously infecting phage L. The results are discussed with respect to the mechanism underlying the different action of P22 antirepressor in L and in P22 lysogens.


Mutants of yeast with depressed DNA synthesis.

Seven temperature-sensitive mutants have been isolated in Saccharomyces cerevisiae which show a reproducible defect in DNA synthesis at the restrictive temperature. One of these is allelic with rna11 (Hartwell et al., 1970) but the remaining mutants define six complementation groups and probably represent six different genes. The gene symbol dds (for depressed DNA synthesis) is proposed. At the restrictive temperature, rna11-2, dds2-1 and dds6-1 show a rapid and almost total cessation of DNA and RNA synthesis, whilst protein synthesis continues for several hours. The remaining dds mutants show a reduced rate of DNA synthesis from the time of temperature shift (dd1, dds3, dds4) or a cessation of DNA synthesis at a later time (dds5). In some cases, RNA synthesis is affected concomitantly with, or soon after, the depression in DNA synthesis. Possible reasons for the phenotypes of these mutants, and for the relative absence of yeast mutants which are unambiguously and specifically affected in DNA synthesis, are discussed. In addition, we report the isolation of seven new alleles of known cdc genes and ten new mutants with a cell cycle phenotype that complement those already known.


Ribosomal RNA transcription in a mutant of Saccharomyces cerevisiae defective in ribosomal protein synthesis.

In Saccharomyces cerevisiae, the transcription of ribosomal precursor RNA is severely inhibited in the absence of protein synthesis. However, such transcription is not dependent on the synthesis of ribosomal proteins, nor on the synthesis of mRNA for ribosomal proteins, nor on the processing of ribosomal precursor RNA.


Coding of stable 4S RNA molecules by the resistance factor R1.

With the aid of DNA-RNA hybridization experiments it was shown that an E. coli strain harbouring the resistance factor R1 contains small, stable RNA species which are capable of annealing with the DNA of this R-factor.  At a higher hybridization temperature RNA molecules form the isogenic, sensitive strain could also hybridize to the R1-DNA. These RNA-species were again detected if the RNA was extracted from P. mirabilis carrying this plasmid. The fact that sulfur-labelled RNA also hybridized to the plasmid DNA seems to indicate that some of these molecules are tRNAs.


The recognition of mismatched base pairs in DNA by DNase I from Ustilago maydis.

The activity of Ustilago maydis DNase I, an enzyme implicated in genetic recombination, on DNA substrates containing unpaired or mismatched bases, was examined. The enzyme nicked supercoiled PM-2 molecules, converting these to relaxed circular and linear molecules. Discrete double stranded linear fragments smaller than unit length were also observed after digestion at high enzyme concentration. Heteroduplex molecules were constructed using phi80 bacteriophage derivatives which contained single base substitutions within the E. coli tRNA1tyr gene. Single and double stranded nicking at or near the single mismatched site was observed with three out of the five pairs of heteroduplexes.


Mutations in the tryptophanyl-transfer ribonucleic acid ligase of E. coli causing temperature-sensitivity for growth.

Strains of Escherichia coli K-12 with altered tryptophanyl-tRNA ligases, conferring temperature-sensitivity for growth, have been isolated as spontaneous one-step mutants. The mutated enzymes differ markedly in activity from the wildtype, even at the permissive temperature. When assayed at the non-permissive temperature, the mutant enzymes are completely inactive. In one of the mutant strains, growth can be completely inhibited by addition of L-phenylalanine or L-tyrosine to the medium.


Phage Mu-1 mediated transposition: a tool to study the organization of ribosomal protein genes in Escherichia coli.

Phage Mu-1 mediated transposition has been used to map genes coding for ribosomal proteins and elongation factor G inside transcriptional units. The data indicate that 1) the str A and fusA genes belong to the same operon, 2) the spcA and strA genes are expressed independently, 3) the spcA gene is located in a different transcriptional unit to that of the eryA and eryB genes.


Detection of specific DNA sequences in yeast by colony hybridization.

A procedure is described for the detection of specific DNA sequences in Saccharomyces cerevisiae. This method allows a rapid screening of a large number of yeast colonies. The yeast cells of each colony, grown on nitrocellulose filters, are converted, in situ, to protoplasts by snail enzyme, and are then lysed and their DNAs are denatured and fixed on the filter. The presence of the specific DNA sequence is detected directly on the filter by hybridization with a radioactive cRNA. We have used successfully this technique to detect the presence or the absence  of specific mt DNA sequences in p+, p- and p0 strains, and to detect the presence or the absence of the 2 mum DNA sequences in different strains.


Yeast chromatin: search for histone H1.

Yeast chromatin, isolated by a rapid procedure contains in addition to histones H2A, H2B, H3 and H4 a fifth major basic protein. This fifth polypeptide is not an intrinsic component of the nucleosome structure. It has properties of both histone and nonhistone proteins and might represent an early form of histone H1 and of high mobility group nonhistone proteins of higher eukaryotes. Electron microscopic visualization of isolated yeast nucleosomes substaniates further the similarity of the chromatin structudre of this unicellular eukaryote to that of higher eukaryotes.


Arginine regulon control in a Salmonella typhimurium--Escherichia coli hybrid merodiploid.

The regulation of synthesis of arg enzymes was studied in a hybrid merodiploid in which an episome of Escherichia coli carrying the argR+ allele was transfered to Salmonella typhimurium argR strain. The arg enzyme levels of the hybrid merodiploid were compared to that found in argR and argR+ haploids of S. typhimurium. The results showed that repression of synthesis of arg enzymes was effected through the introduction of the E. coli argR+ allele but significant quantitative differences of arg enzyme levels in the argR+ haploid and the hybrid merodiploid were observed.


Transposon-mediated insertion of R factor into bacterial chromosome.

Insertion of transposon T n1 into the E. coli JC411 chromosome results in a sharp increase of plasmid RP4 integration frequency. This effect is absent in JC1553 recA cells. The RP4 integration with the chromosome is probably accomplished via recA-dependent recombination between transposon Tn1 inserted into the chromosome and the same transposon in the RP4 plasmid.


Fine structure analysis of the threonine operon in Escherichia coli K-12.

A fine structure analysis of the threonine operon in Escherichia coli K-12 was performed by deletion mapping. Lambda transducing bacteriophages carrying various parts of the threonine operon were isolated from strains in which the lacZ gene was fused to a thr gene. We tested for recombination between deletions of the threonine promotor extending into the threonine operon, carried by the phage, and bacterial thr auxotrophs. The relative order of thrO (operator) mutations was established. We propose that an operator region is located between a promoter region and the structural genes. Mutations leading to the desensitization of the aspartokinase I-homoserine dehydrogenase I towards threonine were localized in two different regions of the thrA gene.


Map position of the replication origin on the E. coli chromosome.

Strains carrying a dnaA temperature sensitive (t.s.) mutation and a Mu-1 prophage inserted within different genes near the origin of replication have been constructed. For each strain, integratively suppressed Hfrs, named G and D in which the ori region was replicated clockwise and counterclockwise respectively, were isolated. The strand preferences of Mu-1 specific Okazaki fragments were subsequently determined for each t.s. strain and its Hfr derivatives. Their comparison led us to establish the direction of replication of the Mu-1 marker from ori. The site ori was confined to the bglB-C--rbsK-P interval.


Mapping of regions on cloned Saccharomyces cerevisiae 2-mum DNA coding for polypeptides synthesized in Escherichia coli minicells.

Saccharomyces cerevisiae 2-mum DNA and some of its restriction fragments were integrated in vector pCR1 ,pBR313 or pBR322 and their expression in Escherichia coli P678-54 minicells was analyzed. 2mum DNA inserted at the EcoRI site of pCR1 or pBR313 and at the PstI site of pBR322 promoted the synthesis of polypeptides of 48,000, 37,000, 35,000 and 19,000 daltons. The DNA regions coding for these polypeptides were mapped on the 2-mum DNA molecule by insertion of single EcoRI or HindIII restriction fragments and comparison of the polypeptides produced. For the synthesis of the 37,000 dalton polypeptide, intact sites RIB and H3 were required. The disappearance of the 37,000 dalton polypeptide on interruption of one of these sites by insertion of the vector, was correlated with the appearance of a polypeptide of 22,000 or 23,500 daltons respectively. The DNA sequence coding for the 37,000 daltons polypeptide, therefore, has to be located in the S-loop region close to or overlapping with the site RIB and H3. Assuming that the 22,000 and the 23,500 dalton polypeptides are truncated forms of the 37,000 dalton polypeptide, the last polypeptide can be exactly mapped. The polypeptide of 48,000 daltons was mapped to that half of the L-loop segment containing the sites H1 and H2. If, however, HindIII fragment H1-H2 was expressed, the 48,000 dalton polypeptide was lost and concomitantly a 43,000 dalton polypeptide appeared. We assume that this polypeptide results from early termination of the polypeptide of 48,000 daltons. The 35,000 and 9,000 dalton polypeptides were mapped to the S-loop region. The integrated inverted repeat sequence of yeast 2-mum Dna did not induce any detectable insert-specific polypeptide synthesis.


Isolation and characterization of the minimal fragment required for autonomous replication ("basic replicon") of a copy mutant (pKN102) of the antibiotic resistance factor R1.

The mini plasmids deriving from pKN102, a copy mutant of the antibiotic resistance factor R1drd-19 of E. coli, share a common DNA sequence of 2.6 kb, which carries the minimal functions for autonomous replication. By cloning of two PstI fragments of this region it could be demonstrated that the "basic replicon" is a DNA segment not larger than 1.8 kb, which carries the orgin of replication and the genetic information for at least two proteins. Protein F (NW=11.000 dalton) seems to be synthesed in larger amounts in minicells of E. coli than protein C (20.000). Plasmids containing this isolated replicon of R1 are completely compatible with the parental plasmid R1drd-19.


A cold sensitive dnaA mutant of E. coli which overinitiates chromosome replication at low temperature.

A heat resistant mutant of E. coli dnaAts46 was isolated, which grows normally only at temperatures above 39 degrees. After a temperature shift from 42 degrees to 32 degrees the mutant overproduces DNA relative to protein. This is due to overinitiation of rounds of chromosome replication at low temperature, as indicated by hybridization and other experiments. The mutation is cotransduced by PI with ilv and could not be separated from dnaAts46 by transduction.


Growth of single-stranded DNA phages in replication mutants of Escherichia coli.

Host capacity for growth of single-stranded DNA phages was investigated with several replication mutants of E. coli. In dnaL708, dnam709 and dnaS707 mutants, multiplication of phiK was not restricted even at 42 degree C. In dnaM710 cells, however, growth of phiK was severely effected at 42 degree C but not at 33 degree C. Upon infection of phiK, parental replicative form was synthesized at the restrictive temperature, whereas subsequent step (replication of progeny replicative form) was blocked in the dnaZ strain. Growth of phiX174 and alpha3, as tested by transfection, was also thermosensitive in the dnaM710 mutant but not in the dnaL708, dnaM709 and dnaS707 strains. In contrast with lambda, microvirid phages could grow in E. coli cells bearing the groPC259, groPC756 or seg-2 mutation.


Evidence for translational repression of arginine biosynthetic enzymes in Escherichia coli: altered regulation in a streptomycin-resistant mutant.

The formation and repressibility of the arginine biosyntietic enzymes acetylornithine delta-aminotransferase (EC 2.6.1.11), acetylornithine deacetylase (EC 3.5.1.16), ornithine carbamoyltransferase (EC 2.1.3.3), and argininosuccinate lyase (EC 4.3.2.1) were studied in an Escherichia coli W derivative (strain 250-10) that carries (a) a mutant allele of the argR regulatory gene causing a diminished repression-derepression range and (b) a streptomycin resistance mutation. In comparison with the streptomycin-sensitive parent 250, all four enzymes (a) are formed as smaller proportions of the total protein (overall range, 12% to 71%), whether the conditions are repressive (arginine excess) or derepressive (arginine restriction), and (b) show increased repressibility ratios, the carbamoyltransferase giving the largest increase (from 5.7 to 25.0). These effects appear to depend on the concurrent expression of the regulatory-gene and streptomycin resistance mutations, as indicated by analogous experiments with canavanine-resistant mutants of 250-10 that have partial argR- character. The results provide evidence for translational repression in the arginine system, and are interpreted in terms of a functional interaction of a mutant arginine repressor with a mutant S12 ribosomal protein. The locale of translational repression may be near the site of S12, and this mode of regulation may involve initiational selectivity of groupwise recognizable arginine messenger RNA's.


The modification of induced genetic change in yeast by an amino acid analogue.

Treatment of diploid yeast cultures with the amino acid analogue, para-fluorophenylalanine (PFPA), at concentrations which caused inhibition of growth, resulted in up to 5 fold increases in the frequency of mitotic gene conversion at two different heteroallelic loci. With haploid yeast cultures, growth in PFPA increased the rate of forward mutation to canavanine resistance by at least 2 fold. Growth of diploids in PFPA prior to exposure to the deaminating agent nitrous acid, the cross-linking agent mitomycin C, the alkylating chemical ethylmethanesulphonate (EMS) and UV light resulted in significant changes in the potency of these diverse mutagens to induce intragenic recombination. For all four mutagens, increased frequencies of gene convertants/viable cell were observed in those cultures which had been exposed to the amino acid analogue prior to mutagen treatment. In haploid WT yeast cells, amino acid analogue incorporation resulted in an enhanced frequency of UV induced forward mutation to canavanine resistance whilst in a DNA repair deficient rad 6 mutant this interaction between UV and PFPA was abolished. The results have been interpreted on the basis of incorporation of the analogue into enzymes involved with DNA replication with a consequent loss of fidelity of such enzymes and increased errors in base incorporation.


Preferential deletion of a specific region of mitochondrial DNA in Saccharomyces cerevisiae by ethidium bromide and 3-carbethoxy-psoralen: directional retention of DNA sequence.

Grande strains of Saccharomyces cerevisiae were mutagenized either by ethidium bromide or by 3-carbethoxy-psoralen (a monofunctional furocoumarin derivative) activated by 365nm light. 973 primary rho- clones induced were randomly collected and analyzed individually for the presence or absence of fifteen mitochondrial genetic markers. 1. Under mild conditions of mutagenesis, 83% of the primary clones showed single-deletion genotypes; a unique order of 14 markers could be deduced from the patterns of the deletion. The gene order confirmed our previous map constructed from the analysis of established non-random petite clones. From the frequencies of disjunction between markers, the distance separating 14 mitochondrial markers were estimated. 2. One region, carrying oxi-3, pho-1 and mit 175 loci, was preferentially lost in rho- mutants: there is a strong constraint in the frequencies of various genotypes found in rho- clones. On each side of this particular region, a bidirectionally oriented pattern of retention of markers is observed.


8-hydroxyquinoline inhibition of DNA synthesis and intragenic recombination during yeast meiosis.

Complete inhibition of sporulation was observed in two strains of Saccharomyces cerevisiae to which 8-hydroxyquinoline was added at a final concentration of 5 microgram/ml during the initial 4 to 6 h of sporulation. The cells were most sensitive to the inhibitor during 4 to 6 interval beginning at approximately 2 h (T2). Its addition during that interval resulted in 70 to 80% lethality in strain 4579 and about 40% in API at T24. When present from T0 onward, 5 microgram/ml of 8-hydroxyquinoline severely inhibited premeiotic DNA replication and reduced the frequency of intragenic recombination at the ade 2  and leu 2 loci by 70 and 100%, respectively, relative to control cultures which did not have the inhibitor present. During the period when the cells were most sensitive, the incorporation of 14C-leucine into protein and 14C-adenine into RNA was not inhibited nor was the polysome content affected. At 150 microgram/ml of inhibitor, incorporation of labeled precursors into RNA and protein were inhibited and the percentage of active ribosomes was reduced by 35% within 45 min, but neither transcription or translation appeared to be completely inhibited at this concentration of the inhibitor.


Effect of caffeine on DNA polymerase I from Escherichia coli: studies in vitro and in vivo.

The influence of caffeine on the activity of DNA polymerase I from E. coli was investigated. Caffeine had no effect on the polymerizing activity but did inhibit both 5' leads to 3' and 3' leads to 5' nuclease activities. The highest inhibition was observed with d(A--T)n as substrate: at a concentration of caffeine of 10 mM, inhibition was about 50%. In studies in vivo with 3 isogenic strains of E. coli, carrying different mutations in the DNA polymerase I gene, the effect of caffeine on survival after ultraviolet irradiation was most marked for the wild-type, pol+, followed by those mutants defective in 3' leads to 5', polA1, and 5' leads to 3' nuclease activities, polA107. Caffeine had little influence on survival of the resA1 mutant which lacks both 5' leads to 3' and 3' leads to 5' nuclease activities. These results support the idea that the influence of caffeine on dark repair may be explained in part by its effect on the nuclease activities of DNA polymerase I.


Biochemical analysis of damage induced in yeast by formaldehyde. II. Induction of cross-links between DNA and protein.

Exposure of Saccharomyces cerevisiae cells to formaldehyde-induced cross-links between DNA and proteins. This damage was demonstrated by three different techniques. Ultraviolet irradiation also produced cross-links between DNA and proteins in yeast.


Strategies for detecting heritable translocations in male mice by fertility testing.

Data from a heritable translocation test were analysed to estimate the best rule for classification of F1 males in normals or partially sterile translocation carriers according to litter size or numbers of live and dead implants per mating. Six rules were compared for classification with up to three litter sizes per F1 male observed. The results indicate that a translocation rate of 2%, or at best of 1%, can be detected with reasonable cost.


Microbial assays for mutagenicity: a modified liquid culture method compared with the agar plate system for precision and sensitivity.

A microbial assay system for mutagenicity was developed in which bacterial cells divided in liquid culture. The statistical and practical problems associated with dividing cells were avoided or reduced, whilst the advantages in precision and reliability resulting from the determination of mutation per colony-forming unit (survivor) and of separating the mutation and selection systems were retained. Seven mutagens, two of which required microsomal activation, were evaluated by this liquid-medium method and by the agar-plate method with two strains of Salmonella typhimurium to determine which assay system was the more sensitive. At highly mutagenic and/or very toxic concentrations of the test substance the liquid-medium assay was markedly more sensitive than the agar-plate assay, but at weakly mutagenic and less toxic concentrations the advantage of the liquid-medium test was reduced; however in only one case was the agar-plate assay obviously the more sensitive. There was a clear indication that the liquid-medium assay would be superior to the agar-plate assay for the detection of mutagenic agents active only at toxic concentrations, and also could be more easily and exactly quantified.


Induction of gene conversion in Saccharomyces cerevisiae by the nitrofluran derivative furylfuramide (AF-2).

The nitrofuran derivative furylfuramide (AF-2) is known to be both mutagenic and carcinogenic in a number of test systems. In this report we show that AF-2 can also induce gene conversion in diploid yeast in a manner dependent on both duration treatment and concentration.


Photolytic binding of the monoazido analog of ethidium to yeast mitochondrial DNA: competition by ethidium.

The [14C]-labeled monoazido analog of ethidium, 3-amino-8-azido-5-ethyl-6-phenylphenanthridinium chloride, when mixed with yeast cells and photolyzed, produced covalent adducts with both nuclear and mitochondrial DNA via the light-generated nitrene. The binding efficiency was about 12 times higher in mitochondrial than nuclear DNA. Moreover, the parent ethidium bromide at a 5-fold excess was an effective competitor for the binding of the monoazide analog with mitochondrial DNA, but not with nuclear DNA.


Testing in vitro of an indirect mutagen (cyclophosphamide) with human leukocyte cultures: Activation by liver perfusion and by incubation with crude liver homogenate.

The indirect mutagen cyclophosphamide was tested in human whole blood cultures with respect to chromosome-breaking activities and suppression of mitotic indices after activation by liver perfusion and crude liver homogenates with and without cofactors. Both methods produced nearly the same effects, with the exception of liver homogenate without cofactors which had only weak metabolic activities.


Analytical and biological analyses of test materials from the synthetic fuel technologies. I. Mutagenicity of crude oils determined by the Salmonella typhimurium/microsomal activation system.

We have assayed the mutagenicity of crude industrial products and effluents with the Salmonella/microsomal activation system. Test materials (crude products from coal-conversion processes and natural crude oils) were initially fractionated into primary classes by liquid--liquid extraction and then further fractionated by column chromatography. Prescreening was accomplished over a wide concentration range with the Ames tester strains. Active fractions (mainly the neutral fractions containing polycyclic aromatic hydrocarbons and certain basic fractions) can be identified, and dose--response relationships can be established. Standard values are expressed as revertants/mg of the test material assayed with frameshift strain TA98 including metabolic activation with rat-liver preparations. Total mutagenic activity of synthetic fuel samples was consistently higher than that of natural crude "controls." Activities of subfractions are roughly additive and presumably reflect the mutagenic potential of the whole test material. These results are being extended to other genetic assays. Chemical identification is carried out along with the bioassays.


Microbiological mutagenicity studies of pesticides in vitro.

14 pesticides were tested as pure compounds for the induction of point mutations in four strains of Salmonella typhimurium--TA1535, TA1536, TA1537 and TA1538--in the presence and in the absence of rat-liver microsomal fractions and for the induction of resistance to low concentrations of streptomycin in the filamentous bacterium, Streptomyces coelicolor. The technique used was essentially the so-called "spot test". The pesticides investigated were: aminotriazole, Benomyl, Captafol, Captan, Dichlorvos, Dalapon-Na, Dinobuton, Dodine, Ioxynil, Mecoprop, Neburon, Picloram, Triallate and Trichlorphon. In Salmonella, Captan and Triallate were mutagenic on the TA1535 strain; Dichlorvos and Trichlorphon were negative in the spot test but mutagenic after incubation in liquid cultures of strain TA1535. By using the S. coelicolor forward-mutation test, aminotriazole, Dichlorvos, Picloram, Trichlorphon and Triallate were mutagenic with the "spot test" technique; Captan showed a weak mutagenic activity with a "plate-incorporated" technique.


Mutagenicity of BCNU and related chloroethylnitrosoureas in Drosophila.

BCNU and 10 related chloroethylnitrosoureas were tested for their ability to induce sex-linked recessive lethals in Drosophila spermatozoa. All chloroethylnitrosoureas tested were potent mutagens. Among the substances with one chloroethylnitrosourea group, chlorozotocin, BCNU and methanesulfonyloxyethyl chloroethylnitrosourea exhibited the strongest mutagenic effects. Two hydroxyalkyl chloroethylnitrosoureas behaved as potent mutagens too, although the mutation frequencies obtained were one order of magnitude lower relative to the other substances. Among the compounds with two chloroethylnitrosourea groups, bisCNU-ethane and bisCNU-diphenylmethane were most active. When the interconnecting polymethylene chain was elongated from 2 methylene groups (bisCNU-ethane) to 6 methylene groups (bisCNU-hexane), the mutagenic activity decreased by a factor of 2. The mutagenic activity of polymethylene bischloroethylnitrosoureas with connecting chains of intermediate length was not different from bisCNU-hexane. Differences in mutagenic activity were supposed to reflect different concentrations reaching the target cells, possibly in part as a result of differences in transportability of the substances.


Suppression of Hela cell growth and increase in nuclear size by chemical carcinogens: a possible screening method.

HeLa cell monolayers were "pulse" treated with either carcinogenic or "non-carcinogenic" chemicals. Pre-carcinogens were added with a liver homogenate to provide an appropriate metabolizing system. All proximate carcinogens and a proportion of pre-carcinogens were able to inhibit cell division, and in all cases examined, this was accompanied by nuclear enlargement. Although several "non-carcinogenic" chemicals also arrested cell division, nuclear enlargment was not produced. The possibility that growth inhibition and nuclear enlargement in cells treated briefly with a chemical could provide a rapid indication of carcinogenic activity is discussed.


Absence of immunization effect in human-kidney retransplantation.

We examined whether rejection of a previous graft rendered a recipient immunized against subsequent kidney transplants in over 1900 retransplants. The one-year survival rate (43 +/- 1 per cent [ +/- S.E.M.]) of second grafts from cadaver donors was only slightly (but statistically significantly) lower than that of first transplant (47 +/- 1 per cent, P less than 0.02). Repeated HLA mismatches in 180 second transplants did not show a lower survival rate than 925 grafts with no repeated HLA incompatibility. We conclude that the danger of immunization by previous grafts has been overemphasized from studies in laboratory animals. Those who rejected the first graft rapidly (high responders) had significantly shorter survival of the second graft compared with those who rejected the initial graft slowly (low responders) (60 +/- 3 versus 31 +/- 3 per cent at one year, P less than 0.00001).


The social and economic cost of end-stage renal disease. A patient's perspective.

The soical and economic effects of end-stage renal disease are enormous. This case history of our experience with dialysis and transplantation details our life with these two modes of treatment. Despite the common notion that Medicare covers most of the expenses, the detailed records of our financial experience show that Medicare paid only 53 per cent of our total costs; the remainder came from a mixture of private and public sources. In seeking alternative financial support, we encountered many problems, including complex and constraining requirements for aid, invasion of privacy, high insurance and bank-interest rates and termination of employment. Even those in middle-income brackets find it difficult to maintain their independence under such circumstances. New legislation extending Medicare coverage of home dialysis and transplantation should help to alleviate these problems in the future.


Islet-cell-surface antibodies in juvenile diabetes mellitus.

Using an indirect immunofluorescence test on suspensions of viable, insulin-producing islet cells from rats, we found that 32 per cent (28/88) of insulin-treated patients with juvenile diabetes have islet-cell-surface antibodies in their circulation. These antibodies also occurred in four of nine children with glucose intolerance, in one of 24 healthy children and in nondiabetic children with thyroid disorders. In the diabetic children, the immunofluorescent reaction was inhibited by preadsorption of serum to islet cells but was little affected by preadsorption to rat hepatocytes or erythrocytes or to acetone powders of various rat tissues, including pancreas. These results show that organ-specific, nonspecies-specific antibodies reactive with the cell surface of the islet cells can be present in serum from diabetic children, and provide an approach to investigation of immunopathological aspects of diabetes mellitus.


Structure and processing of yeast precursor tRNAs containing intervening sequences.

We have isolated a precursor of yeast tRNATyr and shown that it contains an intervening sequence identical to that found in the gene for tRNATyr. The conformation of pre-tRNATyr is similar to that of mature tRNATyr except for the anticodon loop. The loop is sensitive to endonucleolytic cleavage by S1 nuclease near to the ends of the intervening sequence. This pre-tRNA is functionally inactive as it cannot be aminoacylated and the anticodon is not accessible for hydrogen bonding. A crude nuclear extract from yeast contains an excision-ligase activity which will process pre-tRNATyr into mature tRNATyr.


Antibody-coated bacteria in the urinary sediment of rats with experimental pyelonephritis.

The appearance of antibody-coated bacteria in urinary sediment has been evaluated in rats with experimental pyelonephritis. At day 7 after induction of pyelonephritis, 9 out of 11 rats demonstrated antibody-coated bacteria in the urinary sediment. The other 2 rats never had a positive urinary sediment. Following removal of the pyelonephritic kidneys, antibody-coated bacteria disappeared in 7 of 9 previously positive rats. In the 2 rats which continued to show antibody-coated bacteria, the infecting organisms were found in the remaining kidney. The 2 rats which never developed antibody-coated bacteria in urinary sediment had a higher then normal serum antibody titer, and 1 rat with antibody-coated bacteria showed a normal serum antibody titer. It is concluded that although the search for antibody-coated bacteria in urinary sediment is a very useful technique, its negativity does not exclude upper urinary tract involvement; in the case of renal parenchymal infection, immunity is not the same at the systemic and the local site.


Electrophysiological characteristics of identified tubero-infundibular neurons.

This article aims to review the recent electrophysiological studies on the distribution of antidromically identified TI neurons, efferent projections of TI axon collaterals, afferent neural connections to TI neurons, and neural pathways mediating recurrent inhibition and excitation in TI neurons.


Traumatic embolization of the intracranial internal carotid artery.

A 3 mm pellet, shot into the neck of a 13 year old boy, migrated into the common carotid artery and lodged in the infraclinoid internal carotid artery. The case illustrates an unusual intravascular migration of a foreign body. The benign clinical course, radiological evaluation, and rationale for expectant management of such low velocity missle injuries is discussed.


Stimulation of gonadotrophs by pituitary portal vessel infusion of superactive LH-RH analogues: an ultrastructural study.

LH-RH or its superactive analogues were infused into pituitary portal vessels of adult male rats for 1 min; pituitaries were then fixed for routine electron microscopy 1 min, 30 min and 3 h after infusion. A maximal increase of granule release at 2 min. and a maximal increase in synthetic activity (i.e., dilated cisternae of rough endoplasmic reticulum (RER) and Golgi apparatus (GA)) at 30 min, occurred in gonadotrophs in response to both LH-RH and the superactive analogues, but not to saline infusion. Only gonadotrophs from analogue infused pituitaries showed a high level of exocytosis and protein synthesis at 3 h. In addition, the superactive analogues typically stimulated formation of large vacuoles of RER at 30 min and 3 h that resembled those seen in "signet ring" cells following castration. Radioimmunoassay (RIA) values of serum LH supported these observations. The results of this study provide morphological evidence for a prolonged action of the superactive analogues of LH-RH on both gonadotropin secretion and synthesis under physiological conditions.


[Effect of amygdalotomy on behavior disorders in epileptics].

Results of psychological testing in 46 epileptics with severe behaviour disturbances treated surgically, by the stereotaxic method (selective exclusion of the dorso medial parts of amygdalae) are reported. After the operation there was a significant improvement of behaviour and seizures of temporal-lobe type were no longer observed. Comparative tests demonstrated a significant reduction of emotional tension, development of ability to behaviour and emotional reactions control, reduction of emotional instability and motor hyperactivity. Aggressiveness in difficult or conflict situations was markedly diminished or eliminated.


[Behavior of serum proteins and lipids after jejuno-ileal bypass for obesity].

Variations in body weight, behaviour of lipidaemic fractions proteinaemia, uricaemia and uricuria, and lipid and protein absorption were studied preoperatively and at varying times following operation in five subjects who had undergone jejuno-ileal bypass for obesity. The results showed high serous NEFA and a definite, early and persistent reduction in all lipidaemic fractions after operation. The post-operative levels of serous proteins, particularly albumin, which were reduced in all subjects, reached pathological levels in two patients where proteic malnutrition following on the operation was associated with serious liver disease. The results agree with reported data. The variations in lipidic and proteic malabsorption proved to be in agreement with weight drop and the serous parameters considered. The reduction in uricaemia encountered in the five patients studied failed to agree with data reported in the Anglo-Saxon literature. This may be explained by alimentary and racial differences between the two populations of patients.


The treatment of hypertension with verapamil.

In a randomised double blind cross over trial, verapamil produced significant dose dependent reductions in blood pressure in 23 patients. There were minimal side-effects. All patients had some contraindication to the use of beta blocker therapy, and the role of verapmil in this situation is discussed.


Genetic counselling and genetics of cleft lip and cleft palate.

Modern neonatal care and advanced plastic surgical correction have led to the survival of most newborns with oral clefts. These children are likely to reproduce. A slight increase in the incidence of oral clefts may be expected in the future. The genetics of cleft lip and cleft palate is reviewed. The inheritance is usually multifactorial. With normal parents the risk of having a first affected child with cleft lip is about one per thousand, the risk of having a second affected child 4 per cent and the risk of having a third affected child 10 per cent. If a parent has already a cleft lip, the risk of having a first affected child now is 4 per cent, while the risk of having a second affected child is 10 per cent. The methodology of genetic counseling is given.


[Experimental and biochemical aspects of crystalline lens induction during embryogenesis].

The lens induction is a two-step process and involves morphogenetic influences from the archencepalic endoderm and optic vesicle. One can suggest that the lens induction is primed by specific proteins which are synthesized and secreted by the optic vesicle cells. The proteins-inductors appear to penetrate in the cells and, while interacting (directly or via the cytoplasm) with the nuclei, "programme" the ectodermal cells towards the lens differentiation. The contact interactions and extracellular matrix are of substantial, but not crucial value for the lens induction. The synthesis of specific proteins (crystallins) is to be considered as the most objective criterion of lens differentiation. In vertebrates, there is a lag-period between the moment of lens induction and synthesis of crystallins which is the most long-term in amphibians. The chick embryos constitute an exception and the synthesis of crystallin mRNA occurs in them a few hours after the lens induction. The developing retina loses its capacity to induce lens but stimulates the processes of fiber formation and synthesis of crystallins. A factor was found in the definitive lens epithelium which may be considered as a possible regulator of lens differentiation. On the basis of experiments with heterogenous and native lens inductors, a suggestion is put forward to the effect that the activity of inducing substances is determined by a definite determinant group of the molecule, rather than by the whole molecule.


[Origin of stromal bone marrow mechanocytes according to the results of typing them by isoantigens and chromosomal markers].

The bone marrow of radiochimaeras and heterotopic bone marrow transplants were used to study the origin of precursors of the fibroblasts growing in the monolayer cultures of hemopoietic tissue. In the bone marrow explants of the (C57BL/6 X CBA) F1 mice, in which the CBA bone marrow was transplanted following the lethal irradiation, the fibroblasts grown in the colonies were of recipient origin judging by isoantigens in the reaction of indirect immunofluorescence with the anti-C57BL/6-serum. At the same time in the bone marrow explants from heterotopic transplants (CBA leads to CBA X C57BL/6) the fibroblasts grown in colonies were of donor origin. The cultures of hemopoietic cells of the bone marrow of females heterotopically transplanted in the singenic male (guinea pigs Huston) contained only fibroblasts which were of donor origin judging by sex chromosomes in the metaphase plates of dividing cells. Hence, the bone marrow precursors of fibroblasts do not depend histogenetically on hemopoietic cells and are not replaced at the expense of repopulating cells of the second partner.


[Immunofluorescent study of the origin of connective tissue cells in xenogenic radiation chimeras under normal conditions and in aseptic inflammation].

The origin of elements of the focus of aseptic inflammation and the normal subcutaneous connective tissue in the xenogenic (mouse-rat) radiation chimaeras was investigated by means of indirect Coons method with antiserum to the rat bone marrow cells. The cells of the imflammation focus (leucocytes, macrophages, fibroblasts or fibroblast-like cells, polynuclear giant cells of foreign bodies), as well as leucocytes, macrophages and some fibroblasts of the normal subcutaneous connective tissue, were shown to take their origin from the transplanted bone marrow cells of the donor.


Current trends in amblyopia therapy.

This report reviews the literature on amblyopia therapy from 1970 through 1976. New techniques of screening for amblyopia have been developed during this period. Modification of therapy which includes the use of penalization, prisms, red filter, and home exercises has been reported in the current literature. A summary of the author's personal experience in the treatment of amblyopia at the Bascom Palmer Eey Institute from 1966 through 1976 is presented with the factors that influenced the outcome of this therapy.


Electrophysiologic aspects of amblyopia.

This paper presents a sampling of the psychophysical and electrophysiologic examinations which have been applied to determine the location of the visual processing defect in functional amblyopia. Areal summation and lateral inhibition are discussed along with methods for determining their extent at different locations in the visual system. Using psychophysical and visual-evoked response data from a series of these tests in humans, a case is made that the outer retina is the locus of a major defect leading to the loss of visual resolution in functional amblyopia.


Recovery from monocular stimulus deprivation amblyopia in the kitten.

A review of experimental studies on recovery from monocular stimulus deprivation amblyopia in the kitten is presented. Physiologic, anatomic, and behavioral results are reported for two kinds of recovery experiments: (1) those in which reverse deprivation is employed and (2) those utilizing a recovery period of binocular vision. Data from these investigations are discussed in relation to current thinking regarding the role of synaptic competition during the development of the visual system. The conclusions drawn from these experimental studies of monocular deprivation suggest a possible approach to the treatment of human amblyopia.


The pharmacology of amblyopia.

Physiologic and anatomic evidence has suggested an anatomic disconnection between the deprived eye and visual cortical neurons in cats made amblyopic by monocular deprivation. Clinical and visual-evoked response data suggest, however, that inhibition may play a major role in amblyopia. Accordingly, we intravenously administered anti-inhibitory compounds (bicuculline, ammonium ion, naloxone) to amblyopic cats and demonstrated a substantial restoration of binocular input to the visual cortex. Such pharmacologic reversal suggests that amblyopia is not an anatomically fixed lesion.