Co-translational modification of nascent immunoglobulin heavy and light chains.

We have investigated the in vivo co-translational covalent modification of nascent immunoglobulin heavy and light chains. Nascent polypeptides were separated from completed polypeptides by ion-exchange chromatography of solubilized ribosomes on QAE-Sephadex. First, we have demonstrated that MPC 11 nascent heavy chains are quantitatively glycosylated very soon after the asparaginyl acceptor site passes through the membrane into the cisterna of the rough endoplasmic reticulum. Nonglycosylated completed heavy chains of various classes cannot be glycosylated after release from the ribosome, due either to rapid intramolecular folding and/or intermolecular assembly, which cause the acceptor site to become unavailable for the glycosylation enzyme. Second, we have shown that the formation of the correct intrachain disulfide loop within the first light chain domain occurs rapidly and quantitatively as soon as the appropriate cysteine residues of the nascent light chain pass through the membrane into the cisterna of the endoplasmic reticulum. The intrachain disulfide loop in the second or constant region domain of the light chain is not formed on nascent chains, because one of the cysteine residues involved in this disulfide bond does not pass through the endoplasmic reticulum membrane prior to chain completion and release from the ribosome. Third, we have demonstrated that some of the initial covalent assembly (formation of interchain disulfide bonds) occurs on nascent heavy chains prior to their release from the ribosome. The results are consistent with the pathway of covalent assembly of the cell line, in that completed light chains are assembled onto nascent heavy chains in MPC 11 cells (IgG2b), where a heavy-light half molecule is the major initial covalent intermediate; and completed heavy chains are assembled onto nascent heavy chains in MOPC 21 cells (IgG1), where a heavy chain dimer is the major initial disulfide linked intermediate.


Choroidal melanocytes - a model for studying the aging process in nonreplicative differentiated cells.

Choroidal melanocytes differentiate and cease to divide early in postnatal life. They have characteristic organelles, the melanosomes, which are formed from tyrosine in a reaction catalyzed by tyrosinase. As animals become old, enzyme activity declines and the melanosomes show changes that are quantitatively and qualitatively correlated to the animal's increasing age.


Effects of glutaraldehyde and other drugs on concanavalin A-mediated red blood cell adsorption to nonsenescent, senescent and transformed human fibroblasts.

Concanavalin A (Con A)-mediated red blood cell (RBC) adsorption with the RBC coating method (in which Con A-coated RBC's are adsorbed to fibroblasts) was greatly increased by glutaraldehyde fixation of RBCs before Con A-coating and decreased by the fixation of fibroblasts. On the other hand, RBC adsorption with the fibroblast coating method (in which RBCs are adsorbed to Con A-coated fibroblasts) was decreased by the fixation of RBCs and increased by the fixation of fibroblasts before Con A coating. The fixation of RBCs or fibroblasts after Con A coating did not have these effects. In addition, the fixation of both RBCs and fibroblasts nearly completely abolished RBC adsorption with either method. However, the amount of [3H] Con A binding was not affected by the fixation. RBC adsorption with the fibroblast coating method was also affected by cytochalasin B, colchicine, NaN3 and dibucane treatments of fibroblasts. These drug treatments of fibroblasts, however, did not affect RBC adsorption with the RBC coating method, except cytochalasin B. In addition, the effects of drug treatments of fibroblasts examined occurred nearly to the same extent for nonsenescent, senescent, and transformed cells. Our results suggest that secondary processes after Con A binding, receptor mobility and receptor association with cytoskeletals, play important roles in RBC adsorption, but that the roles do not change with aging or transformation.


Differential stimulation of hepatic mono-oxygenase and glucuronidating systems in chick embryo and neonatal rat by glucocorticoids.

White Leghorn embryos infused with corticosterone precociously reproduced the hatching surges of hepatic UDPglucuronosyltransferase activity to 2-aminophenol, aminopyrine N-demethylase activity and cytochrome P-450 concentration. Onset of transferase activity followed that of the others by 48 h over hatching and on infusion. Competence of demethylase and transferase to respond to corticosterone appeared over days 12--14. Glucocorticoids are suggested as the natural triggers of both transferase and monooxygenase activities in chick and both processes may share a further control. Exposure of CD rat foetuses at 18 1/2 days to dexamethasone by maternal injection evoked precocious onset of transferase activity to 2-aminophenol but not to bilirubin, nor of demethylase activity or cytochrome P-450 content. Injection of hour-old or infant rats with dexamethasone did reproduce precociously onset of the three latter and stimulated the former. Competence for glucocorticoid response thus appeared before birth for transferase activity to 2-aminophenol and at birth for the others. Onset of transferase following hatching or glucocorticoid lagged behind that of demethylase or cytochrome P-450 by 48 h in chick embryo and 36 h in newborn and infant rats; only in foetal rat was response of transferase rapid to administered glucocorticoid.


Purification of mouse liver UDPglucuronosyltransferase.

The present study describes a method for the purification of hepatic microsomal UDPglucuronosyltransferase from two different strains of mice, by a combination of detergent solubilization, ion-exchange chromatography and affinity chromatography. Using this procedure up to 0.5 mg of UDPglucuronosyltransferase could be obtained from 30 g of mouse liver and this enzyme could be purified from as little as 10 g of mouse liver. The molecular weight of the apparently homogeneous preparation was 57 000 +/- 2 000 when determined by sodium dodecyl sulphate polyacrylamide gel electrophoresis. The purified transferase catalysed the glucuronidation of approx. 0.6 mumol 4-nitrophenol min-1. mg-1 protein. Immunochemical analysis of this preparation further indicates that UDPglucuronosyltransferase has been purified to apparent homogeneity.


Studies on the inhibition of hepatic microsomal glucuronidation by uridine nucleotides or adenosine triphosphate.

The ability of five nucleotides in the presence of excess divalent cations to inhibit UDPglucuronosyltransferase in sealed or leaky liver microsomal vesicles was studied. Two nucleotides inhibited potently while three others were weak inhibitors. At low concentration, both of the potent inhibitors, uridine tri- and diphosphates tended to inhibit more in sealed microsomal vesicles than in leaky microsomes, while the weak inhibitors, uridine diphosphate glucose and adenosine triphosphate behaved in the opposite manner and inhibited less in sealed than in leaky microsomes. At physiological concentrations of UDPglucuronic acid (0.4 mM) quite extensive inhibition of oestradiol glucuronidation could be achieved with physiological concentrations of uridine tri- or diphosphates (0.2 or 0.4 mM). In sealed or leaky microsomes, beta, gamma-methylene-interrupted uridine triphosphate, which is resistant to hydrolysis by nucleoside triphosphatase, inhibited much less than did uridine triphosphate.


Effects of lipid peroxidation on the activity of microsomal UDPglucuronosyltranserase.

This study is concerned with effects of lipid peroxidation of liver microsomal fractions in vitro on the activity of the membrane-dependent enzyme UDPglucuronosyltransferase. Peroxidation was initiated by the ascorbate-Fe2+ redox couple. Peroxidation had a biphasic effect on transferase activity (with p-nitrophenol or o-aminophenol as acceptors). An initial activation at low levels of peroxidation was followed by inactivation after more prolonged peroxidation. Activation was more pronounced with rat preparations than with those from guinea pig. When taken in conjunction with previous work on the effects of membrane perturbants on transferase activity the results indicate that activation was the result of membrane perturbation, probably resulting from shortening of phospholipid hydrocarbon chains. The inactivation of the enzyme in guinea pig liver microsomal preparations was not reversed by adding phospholipids. It is concluded that the irreversible inactivation was probably due to chemical reaction of intermediate products of peroxidation with essential membrane components, possibly the enzyme itself. Further experiements suggested that lipid peroxides were responsible.


Glucuronidation of 3-hydroxybenzo(a)pyrene in liver microsomes.

A simple and sensitive fluorimetric method is described for evaluation of 3-hydroxybenzo(a)pyrene conjugation with UDPglucuronic acid. It is less expensive than a radiochemical method and suitable for routine use. 3-Hydroxybenzo(a)pyrene is readily conjugated in isolated liver microsomes in the presence of UDPglucuronic acid. Activity in rat liver microsomes was 0.90--1.20 nmol.min-1.mg-1 microsomal protein. The activity in homozygous and heteroxygous Gunn rats was considerably lower than in Wistar rats. Activity in guinea pigs was 2.5--3 nmol.min-1.mg-1 protein. 3-Methylcholanthrene pretreatment (20 mg/kg of body weight for 4 consecutive days) of rats enhanced the hepatic UDPglucuronosyltransferase activity 2--5 fold. In untreated microsomal membranes of rat liver the apparent Km for 3-hydroxybenzo(a)pyrene was 0.09 mM and for Udpglucuronic acid 4.6 mM. Conjugation with UDPglucose did not occur. 4-Nitrophenol and 4-nitrophenyl-beta-D-glucuronide behaved like non competitive inhibitors. In contrast to 4-nitrophenol conjugation, both ionic (cholic acid) and non-ionic (Triton X-100, digitonin) surfactants had no effect or inhibited the glucuronic acid conjugation of 3-hydroxybenzo(a)pyrene in rat liver microsomes as also did the treatment of microsomal membranes with phospholipases A and C. Trypsin was almost without an effect on UDPglucuronosyltransferase activity when 3-hydroxybenzo(a)pyrene was used as substrate.


Effects of intermittent styrene inhalation, ethanol intake and their combination on drug biotransformation in rat liver and kidneys.

The modifying effects of daily ethanol ingestion in the drinking water as a 15 % solution (v/v) on drug biotransformational changes induced by inhalation exposure to styrene (300 ppm or 1260 mg/m3, 6 h daily, 5 d/week, up to 17 weeks) were studied in rat liver and kidney. The drug hydroxylation activities (7-ethoxycoumarin O-deethylase and 2,5-diphenyloxazole hydroxylase) both in liver and in kidneys were increased more by ethanol ingestion than by styrene inhalation. When administered in combination, styrene and ethanol exerted mostly an additive enhancing effect. However, hepatic NADPH-cytochrome c reductase activity was reduced both in styrene and in ethanol-treated rats. Hepatic styrene oxide hydratase activity was virtually unaffected by styrene treatments. The depression of glutathione concentration in liver was greater after styrene-ethanol than after styrene treatment alone. The hepatic UDPglucuronosyltransferase activity was enhanced slightly both in styrene and in styrene-ethanol rats. The binding affinity of styrene towards cytochrome P-450 was increased after styrene inhalation as shown by lowered K8 values. The perirenal fat concentration of styrene showed a rough inverse relationship to the overall monooxygenation activities in liver and kidney. Despite the additively induced enzyme activities in styrene-ethanol-treated rats the accumulation of styrene in fat of these animals was on the whole somewhat greater, suggesting that these two solvents in vivo also have mutual inhibitory effects on biotransformation.


The genome of B. subtilis phage SPP1: physical arrangement in phage genes.

41 genes of SPP1 have been delineated by using complementation analyses of 75 conditionally lethal (ts and sus) mutations. The physical locations of these genes on the SPP1 chromosome have been determined by transfection/marker rescue experiments in which restriction endonuclease generated fragments of SPP1 DNA were used as donor DNA. The physical order of these fragments has been previously established (Ratcliff et al., 1979).


Analyses of mouse and Drosophila proteins by two-dimensional gel electrophoresis.

Two-dimensional gel electrophoresis was employed for the protein analysis of several different mouse tissues and Drosophila. The number of protein spots detected with conventional protein dye staining techniques ranged from 110 in erythrocyte lysate to 320 in liver homogenate. Strain variation of protein spots on the gels was examined in five different tissues from two strains of inbred mice (DBA/2J and C57BL/6J) and their F1 hybrids. The protein spots which exhibited strain variation were shown to be autosomally inherited and to follow Mendelian genetics. From these analyses, it was shown that the frequencies of protein variations between these two strains of mice vary from 1 to 5% with the tissue examined. During the course of this study, the protein spots corresponding to nine muscle proteins and three testis enzymes from the mouse as well as two Drosophila enzymes were assigned on two-dimensional gels of their respective homogenates. Radioisotope labelling of Drosophila and autoradiography of the two-dimensional gels were also performed to improve the sensitivity and resolution of the technique. The potential application of two-dimensional gel electrophoresis for mutant screening as well as biochemical genetic studies is discussed.


[Acute meningo-encephalitis in adolescents and adults--I. Germs, rate of morbidity and lethality (author's transl)].

Diverse forms of acute meningo-encephalitis found in adolescents and adults are discussed considering 1244 cases treated at the Neurologic Clinic of the University at Cologne in the time from 1950 till 1975. The rate of morbidity and lethality was found to vary according to the type of causative germ. The inflammation often took another course than in childhood. The age at the outbreak of the disease, infection immunity, precursing and concomitant illnesses as well as the onset of medication influence the outcome of the meningo-encephalitis.


[Hemorrhagic diathesis in patients with malignant neoplasms (author's transl)].

Clotting analysis in 30 patients with bleeding complications in malignant hematological diseases revealed the following troubles: The global tests, Quick's index and partial thromboplastin time markedly differed from normal. Activity of clotting factors revealed hypo- or hyperfibrinogenemia, disturbances of the prothrombin complex (factors II, VII, IX and X), decrease of factors V, VIII, XII. Factor XI (= PTA) was not diminished in any case. Regarding the fibrin-stabilizing factor (factor XIII), its activity was significantly decreased in 30 patients with solid tumors and in 30 patients with hemoblastoses. Faulty clotting balance was characterized by hyperfibrinolysis or disseminated intravascular coagulation (DIC) accompanied by reactive hyperfibrinolysis. About one quarter of the patients with malignant disturbances of the hematopoetic system demonstrated (mostly amegacaryocyte) thrombocytopenia. Finally, treatment of bleeding complications in malignant neoplastic diseases is pointed out.


Ewing sarcoma: treatment with high dose radiation and adjuvant chemotherapy.

Twenty-one patients with pathologically proven Ewing sarcoma without overt metastases at diagnosis were treated with a protocol designed by the Royal Marsden/St. Bartholomew's Hospitals Children's Solid Tumour Group (CSTG). They received megavoltage radiotherapy to the involved bone and adjuvant chemotherapy with a combination of four cytotoxic drugs. Seven patients have so far relapsed, four at the original site and three in other bones. The other 14 are clinically free of disease a median of 36 months from diagnosis. Comparison with a historical control group of 19 patients treated with surgery or radiotherapy, but without initial chemotherapy, shows a significant improvement in survival for the study group (P = 0.03). Seventeen of the controls have died. The treatment regime was moderately toxic, but there were no treatment-related deaths. These results confirm that an improved survival time and hopefully cure rate can be expected from treating Ewing tumour with high doses of megavoltage radiation and combination chemotherapy. Future goals must be the better control of large primary lesions and the eradication of micrometastases in other bones. The place of surgery should be re-evaluated in the treatment of the primary tumour, and better adjuvant chemotherapy regimes are needed.


Relapse rates following cessation of chemotherapy during complete remission of acute lymphocytic leukemia.

The therapeutic benefit of maintenance chemotherapy beyond three years for children with acute lymphocytic leukemia (ALL) in continuous complete remission was evaluated by the investigators of Childrens Cancer Study Group (CCSG). Two hundred and twenty leukemic children in first remission for three years or longer and who had received at least three years of continuous chemotherapy were eligible. One hundred and one patients were randomized to either continue chemotherapy for an additional three years or to discontinue therapy, and 119 patients nonrandomly continued or discontinued therapy. The patients had received a variety of chemotherapy regimens. The study period extended from April 1970 until December 1977, with a median follow-up time of 25 months. Relapses occurred in 15 randomized patients (15%). Randomized patients remaining on chemotherapy experienced a statistically significant lower relapse rate than patients randomized to discontinue therapy. Also among randomized patients, bone marrow relapse was significantly more frequent in males than in females. Considering the total patient group, age and white blood count at diagnosis had no significance in predicting relapse. Of relapse events in males, 21% were isolated testicular relapses, identifying the testicles as a major risk site in males completing three years of continuous complete remission. This study demonstrates that continuing chemotherapy beyond three years results in a significant prolongation of remission in males, although the eventual survival outcome for later discontinuance of therapy will require longer follow-up.


[Legal aspects of gene manipulation (author's transl)].

The objects, aims and methods of research are protected from political misappropriation. But the freedom of research is limited by the clash with the legally protected third party, especially in the law of integrity of life and limb. To protect the environment from the (hypothetical) epidemiological dangers of gene technology the legislator has limited himself to measures by which he can obtain this aim with the least infringement of freedom of research. Gene technological intervention in human idioplasm is apparently not yet serious. Nevertheless the ethical and legal problems which arise form the point of view of human dignity from experiment with human genetic material should be discussed now.


[A controlled study on the significance of occult blood test in the stool (author's transl)].

1000 patients of a proctological practice were all investigated by coloscopy and parallel to this by comparison of the two tests for occult blood in the stool (Haemoccult and hemo FEC). 5,6% were positive by the Haemoccult test, 5,2% to hemo FEC. There was no significant difference between the two systems. In the entire study 13 carcinomata and 39 benign polyps of 5 mm diameter and more were found, 8 patients with carcinoma had a positive hemo FEC test, 7 had a positive Haemoccult test, i.e. 38% of carcinoma patients were not detected by the hemo FEC test and 46% in the Haemoccult test. Even in patients with somewhat larger polyps, the test for occult blood in the stool was negative in 56%. It is pointed out with reference to two separate patients that in individual cases of even advanced carcinoma of the large intestine no blood can be detected in the stool.


[Gastric diseases in foreign workers in the German Federal Republic (author's transl)].

Gastric biopsies from foreign workers were compared with those from German patients of the same age group. With reference to population statistics investigations showed that a far higher percentage of foreign workers are gastric patients than are Germans of the same age. Chronic atrophic antral gastritis occurs in foreigners twice as often as in a comparative group of Germans. 77% of the duodenal ulcers and 88% of the gastric ulcers are found in the group of foreign workers examined aged from 21 to 40 years. The German patients, on the other hand, show normal gastric mucosa with more than chance frequency compared with foreign workers of corresponding age and sex.


[Epidemiology of hepatitis B (author's transl)].

A hepatitis B epidemic was observed in an institution for retarded children. The mode of transmission and the epidemiology of this disease was studied. Approximately 50% of all children in this institution were infected by the enteral route. 7 children were hospitalized with an accute episode of hepatitis B and recovered completely. 9 children showed persisting hepatitis B surface antigen and DANE-particles in the serum without clinical signs of infection. 6 of those 9 children were diagnosed as trisomy 21. All of them excrete HBs Antigen in saliva, tears and urine. 80% of family members and teaching personnel involved with these children were infected, 23% had an acute episode of hepatitis B.


[The extraoral fistula (author's transl)].

Extraoral fistulas, whether primary or as the residue of an abscess, have different causes. According to case reports in the literature and from clinical experience the dentogenous cause is the more frequent. For this reason a possible tooth involvement should be ruled out before therapy, loss of dental pulp of various origin and periodontal diseases should be excluded, otherwise the treatment must begin with the cause, after which further intervention is usually superfluous.


[Endocarditis therapy with high doses of oral doxycycline: Part II: Clinical study (author's transl)].

Nineteen patients previously treated unsuccessfully, usually with bactericidal antibiotics, received large doses (average: 15-20 mg/kg/day) of oral doxycycline (Vibramycin) after suitable testing for resistance. The good therapeutic results -- complete cure in eleven cases, great improvement in one, doubtful response to doxycycline in four, three failures -- justifies the observation that high oral doses of doxycycline can be considered as an important addition to the possibilities for treatment of endocarditis.


[Hydergin therapy of cerebrovascular insufficiency in patients requiring digitalis. Results of a double-blind study (author's transl)].

In a controlled double-blind trial in 80 patients with cerebrovascular and cardiac insufficiency the differentiated effect of a combination therapy with cardiac glycosides and Hydergin were studied both with regard to parameters of cerebral organic and cardiac performance. Two randomized collectives of patients with an average age of 63 years were compared with each other for this purpose. They received either acetyldigoxin (0.4 mg/day) alone or in combination with Hydergin (3 mg/day). Duration of treatment was 8 weeks altogether. The single treatment with the cardiac glycoside alone does not lead to a satisfactory improvement in the symptoms of cerebral attacks. The results presented of this study support the necessity in these patients of an internist basic therapy in combination with a preparation like Hydergin acting favorably on cerebral metabolism.


[Serum ribonuclease and its importance for renal diagnosis (author's transl)].

Ribonuclease activity in the serum is recommended in the literature for the diagnosis of tumors, especially carcinoma of the pancreas. On the other hand it has long been suspected that serum RNAase increases when renal function is reduced. It is shown that the RNAase activity in human serum correlates well the creatinine clearance. Tumor diseases are frequently coupled with reduced renal function which leads to a rise in RNAase. The serum RNAase activity is therefore only of limited application for tumor diagnosis. The rise in RNAase activity in the serum is, however, a useful measure for the reduced renal function. The analysis of serum RNAase could replace the determination of creatinine clearance.


[Present day problems in the diagnosis of diabetes (author's transl)].

The results of a longterm study showed that only a relatively small percentage of patients with limiting disturbance of glucose tolerance progressed in the direction of diabetic manifestation. There seems therefore to be grounds for the diagnostic term diabetes to be used only for clinically overt diabetes mellitus and to allow the definitions "subclinical diabetes, chemical diabetes, latent diabetes and symptomatic diabetes" to fall into disuse. On the question of quantity for the glucose tolerance test a 75 g load was proposed as a compromise because of the occasional poor tolerance of the 100 g load. For reasons of international comparability it seems better to adhere to the 50 to 100 g load as before.


[Suprapubic drainage of the bladder (author's transl)].

The principal advantages of suprapubic drainage of the bladder compared with the transurethral indwelling catheter are to be seen in holding back ascending infection of the urinary tract and avoidance of urethral trauma. In addition to relieving the bladder in subvesical obstructions the most important indication in practise is continuous drainage of urine in patients in intensive care. With strict observation of puncture technique and contraindications (contracted bladder, tumors in the lower abdomen, bladder carcinoma, macrohematuria and hemorrhagic diathesis) the entire complication rate is 4.3% (2.3% macrohematuria, 1.5% local infection, 0.5% peritoneal lesion). With the introduction of the disposable puncture systems the suprapubic bladder fistula has become a superior alternative to the indwelling catheter in many cases.


[Uric acid stones in children. Identification and therapy of a newly detected defect of adenine-phosphoribosyltransferase (author's transl)].

APRT deficiency, a new cause of supposed "uric acid" stones in young children may be benign or life threatening. This stresses the importance of early recognition and diagnosis. The renal failure, severe in some instances, is preventable because 2,8-DHA formation, the precipitating factor in all, may be controlled by allopurinol preferably without alkali. A low purine diet is advised. "Uric acid" stones in children should always be subjected to sophisticated analysis, and regarded with suspicion in young adults. Diagnosis from red cell APRT activity will be impossible in transfused subjects.


Mutagen-sensitive mutants in Drosophila melanogaster: effects on premutational damage.

Drosophila melanogaster males from a Basc stock were mutagenized with either X-rays, ethyl methanesulfonate (EMS), or nitrogen mustard (HN2). Groups of identically treated males were crossed to different types of female. Sex-linked recessive lethals were scored as a genetic end point. The females used were homozygous for X-chromosomal mutations (mus(1)101D1, mus(1)104D1, mei-9 or mei-41D5) which lead to defective DNA repair and which increase the mutagen sensitivity of larvae. Females from a white stock with normal DNA repair capacities served as controls. The premutational lesions induced in mature sperm are only processed after insemination by the maternal enzyme systems present in the oocytes. Differences in the efficiency of the processing of lesions can lead to maternal effects on the frequency of mutations recovered from mutagenized sperm. It was found that, with the exception of mus(1)104D1, all mutants analysed significantly modify the mutation fixation of one or more types of premutational lesions. The most drastic effect is found with the mus(1)101D1 stock in which HN2-induced DNA cross-links do not lead to sex-linked recessive lethals. It is assumed that mus(1)101D1 is defective in an early step of DNA cross-link repair. Our first set of data clearly demonstrates that the study of maternal effects in Drosophila is an efficient tool to analyse the in vivo function of repair mutations on chemically induced mutagenesis.


Reversion of nonsense mutants induced by 4-nitroquinoline-1-oxide in Schizosaccharomyces pombe.

We have studied the reversion of 8 nonsense alleles located in 7 different genes of Schizosaccharomyces pombe using 4-nitroquinoline-1-oxide (NQO) as a mutagenic agent. The nonsense mutants of S. pombe have been classified according to their suppressibility by defined opal and ochre suppressors into a class of efficiently suppressed opal and a class of inefficiency suppressed ochre mutants. The UGA alleles tested all revert consistently with NQO, in agreement with the high specificity of this mutagen for G-residues reported for bacteria and yeast. The UAA alleles show a lack or a low level of reversion with NQO. This low level of reversion is due to the low level of non-G-specific transversions at A sites of the UAA triplet. Within each class of nonsense mutants the extent of induction is site-dependent. We conclude that NQO acts predominantly on G-residues in S. pombe.


X-ray-induced mutations affecting the level of the enzyme alcohol dehydrogenase in Drosophila melanogaster: frequency and genetic analysis of null-enzyme mutants.

The frequency of X-ray-induced (null-enzyme) mutations at the alcohol dehydrogenase locus in Drosophila melanogaster was measured. The rate of recovery of chromosomes that fail to direct the synthesis of a functional Adh protein is 3 x 10(-8) per R for chromosomes that do not include large chromosome rearrangements. However, this analysis excludes a larger number of chromosomes that are "null-enzyme mutations" because thye are deleted for the region of the Adh locus. The dose of X-rays required to induce a frequency of non-deletion null-enzyme mutants equal to the spontaneous frequency is about 73 rad calculated from the data reported in this communication.


Mutagenic effectiveness of 14.1 MeV neutrons and 200 kV X-rays at the dumpy complex locus of Drosophila melanogaster.

The effectiveness of 14.1 MeV neutrons relative to 200 kV X-rays for the induction of the various kinds of dumpy mutation in mature sperm of Drosophila melanogaster was investigated. The estimated RBE values are: 0.52 for all complete mutations; 0.64 for the (olv, ov) types; 0.33 for the (ol, lv, o, v, c) types; 0.33 for all fractional mutations. These data lend support to the thesis that (1) complete dumpy mutations of the olv and ov types are more frequently associated with chromosomal aberrations than those of the ol, lv, o, v and c types, and (2) fractional mutations and complete mutations of the (ol, lv, o, v, c) types are most probably point mutational events.


X-ray induction of autosomal translocations in spermatozoa of Drosophila melanogaster and maternal effects of X.Y-chromosomes.

Wild-type ORK Drosophila melanogaster males were given an exposure of 3000 R X-radiation. Mature sperm were then sampled by mating to X.Y/X.Y, X.Y/X, or X/X females that carried markers on the second and third chromosomes for the detection of induced autosomal translocations. Two pairs of maternal stocks were used and heterozygous X.Y/X females were obtained by making both reciprocal crosses. The highest frequencies of induced translocations were obtained with X/X females. In one series these frequencies are higher than those obtained with either X.Y/X or X.Y/X.Y females. In the other series a uniform frequency of translocations was obtained with all types of female, except for one of the two types of heterozygous female, which gave lower frequencies. The experiments have provided data which show that the addition of Y-chromosomes to the maternal genome does not have a specific effect on the recovery of induced paternal autosomal translocations. Maternal Y-chromosomes increased the proportions of fertile F1 males, this effect being consistent in direction but varying in degree.


Sensitivity of drosophila mutants to chemical carcinogens.

7 single-mutant and five double-mutant strains of Drosophila melanogaster were tested for their relative sensitivity to the chemical carcinogens: 1-acetylaminofluorene, benzo(alpha)pyrene, N-methyl-N'-nitro-N-nitrosoguanidine, 4-nitro quinoline-1-oxide and aflatoxin B1. Among the single mutants, mei-9a, mei-41D5 and mus(1)104D1 are hypersensitive to all 5 chemicals, whereas mus(1)107D1 is hypersensitive only to 4-nitroquinoline-1-oxide and is slightly sensitive to benzo(alpha)pyrene. The mei-9a mei-41D5 double-mutant is the most sensitive of 5 tested double-mutants which carry the mei-9a allele. When treated with 0.025 mM benzo(alpha)pyrene this double-mutant produces significantly more sex-linked recessive lethals and dominant lethals than does the control. Analysis of double-mutants reveals that the mei-9+ product functions in a different repair pathway of methyl methanesulfonate-induced damage than do the normal products of the mus(1)103, mus(1)104 and mus(1)107 loci. Our findings suggest that the sensitivity of Drosophila repair-deficient mutants could be exploited in screening for potential mutagens and carcinogens.


Effects of caffeine on maternal repair systems in Drosophila melanogaster. Concentration-dependent reversals of the effects of caffeine on chromosome loss and autosome-autosome translocations induced by x-rays in the paternal genome.

Drosophila melanogaster females were treated with 1% caffeine, mated with X-rayed males and the frequencies of induced sex-chromosome loss, translocations between the major autosomes and between the Y-chromosome and the major autosomes determined. In a reversal of the results obtained previously with 0.2% caffeine by Mendelson and Sobels, treatment of females with 1% caffeine led to a decrease in sex-chromosome loss, confirming preliminary data of Zimmering and Osgood and an increase in autosome--autosome translocations. It is suggested that the higher concentration of caffeine inhibits replication permitting more time available for chromosome-type restitutions by means of caffeine-insensitive repair mechanisms. In contrast with results for autosome--autosome translocation, the frequency of Y-autosome translocations was depressed below controls suggesting an isolation (by any one of several means) of Y-chromosome breaks from those in the autosomes.


The genetic control of maternal effects on mutations recovered from X-rayed mature Drosophila sperm.

Drosophila melanogaster males carrying a ring-X-chromosome were X-rayed and crossed to virgin females of 7 stocks, which had their second and third chromosomes systematically substituted. In the same experiment dominant lethals, sex-chromosome losses, and reciprocal translocations were recorded. Maternal effects on mutation fixation were observable as differences in the mutation frequencies observed with the different types of females. With the set of substitution stocks studied it was found that the maternal genotype strongly influences the frequencies of chromosome losses. The influences on classical chromosome-breakage phenomena, such as dominant lethals and translocations, however, are weak. The differences in the chromosome-loss frequencies may result either from different time intervals between insemination and the beginning of chromosome replication, and/or the efficiency of a repair system. One or more strong genetic factors responsible for such modifications could be located on the third chromosome. On the second chromosome, at best only weak factors are present.


Influence of subcellular fractions of mammalian testes on the mutagenic activity of nitrofurans toward Escherichia coli; presence of a co-mutagen-like factor.

The activation of nitrofurans to mutagenic intermediates by testicular tissue was investigated. AF-2 and nitrofurazone were tested in a microsomal suspension assay with strain E. coli K-12 343/113 as indicator and subcellular fractions from rabbit testes. Different mutation patterns were observed in the presence or absence of testicular homogenate, indicating the presence of different mutagenic intermediates. The frequency of arg+ reversion increased proportionally to the homogenate concentration suggesting that the nitrofurans were activated by testicular components to intermediates that induced base-pair substitutions. Other experiments showed that a component of low molecular weight, present in the soluble fraction of homogenates of testes from rabbits, rats and monkeys, was responsible for the increased mutation frequency. It is concluded that this "co-mutagen-like" factor either alters the metabolism of nitrofurans in E. coli and/or promotes the formation of base-pair substitution-type mutations. This direct interaction between a nonenzymic component of mammalian testes and the mutation induction/expression process in E. coli suggests the role of co-mutagen-like factors in the sensitivity of testes to nitrofurans.


Relationship between cytotoxicity and induction of sister-chromatid exchanges in mouse foetal cells exposed to several doses of carcinogenic and non-carcinogenic chemicals.

The increase in sister-chromatid exchanges induced by 5 chemicals, with different DNA damaging and carcinogenic activities, was studied in short-term foetal-mouse cultures. A significant increase in SCE was induced by N-methyl-N'-nitro-N-nitrosoguanidine, N-diazoacetylglycine-amide, azaserine and methotrexate. k-Strophantin, on the contrary, was totally inactive. On a molar basis, MNNG was the most active chemical followed by MTX, AZS and DGA, in that order. At equitoxic concentrations (D37), the order of SCE-inducing abilities was MNNG, DGA, AZS and MTX. Compared with previous data, at equitoxic concentrations, the most DNA-damaging agents were also the most effective in inducing SCE. The SCE increase seems to correlate not with unspecific cytotoxicity but more with DNA damage or other damage at the genome level. MTX, a non-mutagen, which induced SCE only at toxic levels, could be considered a false positive because this positivity may reflect an enhancement of incorporation of 5-BrdUrd into DNA. The positive results obtained with AZS suggest a sufficient sensitivity of the method for detecting relatively weak carcinogens.


Mutagenicity and metabolism of dimethylnitrosamine and benzo[alpha]pyrene in tissue homogenates from inbred Syrian hamsters treated with phenobarbital, 3-methylcholanthrene or polychlorinated biphenyls.

There are significant differences between mice and hamsters in polycyclic hydrocarbon and nitrosamine metabolism. Homogenates of liver, lung and intestinal mucosa from 6 strains of Syrian golden hamster were compared for their ability to metabolize benzo[alpha]pyrene (BP) and dimethylnitrosamine (DMN) to mutagens. Females of strains MHA/SSLak, LSH/SlLak, CB/SsLak, PD4/Lak LHC/Lak and Lak:LVG (SYR) were either untreated or received phenobarbital (PB), 3-methylcholanthrene (MC) or polychlorinated biphenyls (AR) to induce drug-metabolizing enzymes. Salmonella typhimurium TA92 and TA98 were used as indicators of the formation of mutagans. Dimethylnitrosamine demethylase (DMND) was assayed using 1 mM DMN as substrate. Aryl hydrocarbon hydroxylase (AHH) was measured using benzo[alpha]pyrene as substrate. MC does not induced AHH activity in hamster liver, but is an excellent inducer of enzymes converting BP to mutagens. This lack of correlation between increased AHH activity and increased metabolism of BP to mutagen in liver is in marked contrast to correlations seen in mice. MC induces AHH in hamster lung and intestinal mucosa. AR induces AHH in liver, lung and intestinal mucosa. Activity of DMND in liver is not affected by treatment of hamsters with BP or AR, but is repressed approx. 30% by treatment with MC. Activity of DMND and conversion of DMN to mutagen are correlated (r = 0.59) in hamster liver. Microsomes of hamster liver are more effective than those from mouse in converting DMN to mutagen, despite similar DMND activities in livers from the two species.


Effects of the hepatic S9 fraction from aroclor-1254-treated rats on the mutagenicity of benzo[alpha]pyrene and 2-aminoanthracene in the Salmonella/microsome assay.

The mutagenicity of benzo[alpha]pyrene and 2-aminoanthracene for Salmonella typhimurium TA98 in the plate-incorporation test was studied using liver S9 from untreated and aroclor-1254-treated rats. The induction of liver S9 protein, arylhydrocarbon hydroxylase (AHH), and cytochrome P448/450 was followed with time. There was no change in protein concentrations with induction; AHH and cytochrome levels were increased at 1, 3, 5 and 7 days post Aroclor treatment. Benzo[alpha]pyrene mutagenicity was enhanced with Aroclor treatment while 2-aminoanthracene mutagenicity was depressed. The benzo[alpha]pyrene mutagenicity showed a positive correlation with the levels of AHH and cytochrome on the plate; 2-aminoanthracene showed a negative correlation with activity in induced samples.


Studies on the mutagenicity of p-phenylenediamine in Salmonella typhimurium. Presence of PCB's in rat-liver microsomal fraction induced by Aroclor.

The mutagenicity of fresh solutions of p-phenylenediamine (PPD) and Aroclor 1254 was investigated. The histidine-requiring strains of Salmonella typhimurium were used in the absence and presence of uninduced and/or Aroclor-induced rat-liver homogenate. The presence of polychlorinated biphenyls (PCBs) was also examined by chromatographic methods in Aroclor-induced rat-liver homogenate. In the absence of metabolic activation, as well as in the presence of uninduced rat-liver homogenate, PPD was not mutagenic in the strains used. In the presence of Aroclor-induced S9 a twofold increase (or less) was observed in the number of revertant colonies over those of the controls in TA1538 and TA98. There was no increase in the number of revertant colonies over those of the controls when PPD was dissolved in NH4OH solution and the solution mixed with H2O2 before the addition of S9 mix. Aroclor 1254 was not mutagenic in TA1538 or TA98. However, the presence of PCBs in Aroclor-induced rat-liver homogenate (induced S9) was identified by gas-liquid chromatography (GLC), high-performance liquid chromatography (HPLC) and gas--liquid chromatography/mass spectrometry (GC/MS).


Diagnosis of Corynebacterium pyogenes infection in pigs by immunodiffusion test with protease antigen.

A protease antigen was prepared from the culture supernatant of Corynebacterium pyogenes by concentrating with a flash evaporator and ultrafiltration. It was adjusted to the concentration of 32 units by the single radial immunodiffusion with a tentative standard serum. In the immunodiffusion test, the antigen of 4 units reacted enough with sera having an antibody titer ranging from 1 to 128. As a result, it was decided that the antigen of 4 units should be used in the immunodiffusion test for the detection of protease antibody. By the immunodiffusion test, protease antibody was demonstrated in about 35% of 443 sera from pigs collected at random. The antibody titer showed the distribution of 2 peaks. The summits of the two peaks were seen at 4 and 32 of antibody titer, respectively. The valley between the two peaks was seen at 16 of titer. From the result, a diagnostic criterion of the immunodiffusion test was decided provisionally as follows: above 16 of antibody titer is positive, 1 to 8 suspect, and less than 1 negative. On the other hand, protease antibody was demonstrated in sera from 13 of 14 pigs carrying abscesses from which C. pyogenes had been isolated. Its titer was 8 (in 2 pigs), 16 (in 1), 32 (in 3), 64 (in 6), and 128 (in 1). From these results, it was proposed that the immunodiffusion test with protease antigen be used for the diagnosis of C. pyogenes infection in pigs.


Chromatographic pattern of DNA isolated from liver tissue during hepatoma development.

DNA was isolated from livers of the rats treated with DAB during various steps of hepatoma development. After histological examination the tumor tissue was separated from the normal liver tissue and used as the source of DNA. Chromatographic fractionation on DEAE and Ecteola celluloses shows characteristic patterns for DNA isolated at various steps of hepatoma development. The largest differences in hepatoma DNA as compared to normal liver DNA were demonstrated in the DNA fraction eluated with 2.0 M-NaCl and NH3, gradient 0.1--1.0 M (m. w. 2--9 x 10(6)), and an increase in the first DNA fraction (m. w. less than 1 x 10(6)) was observed. Differences in the chromatographic patterns are discussed in terms of direct DAB action on DNA.


Hormone dependency of rat mammary carcinoma--a comparison of two assay systems.

Succinic dehydrogenase activity of the DMBA induced tumor explants cultured with or without hormones was assessed histochemically while receptors for estrogen (ER) and progesterone (PgR) were estimated from the cytosol fraction of the tumor tissue. Tumor regression following ovariectomy (OVX) was kept as the end point for determining hormone dependency. By in vitro method positive correlation was observed in 5 of 6 responsive or hormone dependent tumors, and 13 out of 14 independent tumors. Presence of receptors (ER + PgR, PgR) correlated with responsiveness in 4 of 6 tumors while their absence in the non-responsive group correlated in 6 of 14 tumors. Prolactin responsive tumors did not regress following OVX even if ER + PgR or ER/PgR were present. Using the same tumor tissue the results of hormone dependency by the two methods were identical in only 9 of 20 tumors.


Comparison of the excretion of different types of melanogens in the melanoma patients.

Urinary melanogens are indolic and phenolic compounds which are excreted in an elevated amount in the urine of melanoma patients. Urinary melanogens can be divided into two principal groups according to their behavior during Thormählen test--Thormählen positive melanogens (TPM) and Thormählen negative melanogens (TNM). When comparing TPM and TNM (represented by homovanillic and vanillactic acids) urinary excretion in stage III of melanoma patients we have found two significantly different relations for melanogens excretion, i. e. predominating TPM urinary excretion in melanotic forms of melanomas and predominating homovanillic acid and vanillactic acid urinary excretion in amelanotic forms of melanomas. We assumed that it could be an indirect evidence of the different catalytic activity of either cresolase or catecholase activities of tyrosinase.


Thyroid-stimulating hormone and prolactin responses to thyrotropin-releasing hormone during infusion of epinephrine and propranolol in man.

Male volunteers were administered 100 microgram thyrotropin-releasing hormone (TRH) intravenously during control (saline) and drug (epinephrine-propranolol) infusions. There were no differences in the thyroid-stimulating hormone (TSH) or prolactin responses to TRH during the epinephrine-propranolol infusion periods. There were no significant differences in growth hormone (GH) responses to epinephrine-propranolol infusions. Epinephrine-propranolol had no detectable effect on basal TSH, prolactin and GH concentrations. We conclude that the alpha-adrenergic system does not play any role at the pituitary level in modulating the effect of TRH-stimulated TSH or prolactin secretion in male volunteers.


Treatment of subarachnoid hemorrhage with sodium nitroprusside and phenylephrine: an experimental study.

The effectiveness of simultaneous intravenous sodium nitroprusside and phenylephrine in improving the cerebrovascular disturbances and survival rate after induced subarachnoid hemorrhage (SAH) was studied in the cynomolgus monkey. We measured regional cerebral blood flow (rCBF) using the intra-arterial xenon-133 clearance technique. In our experimental animal model, SAH was associated with a persistent reduction in rCBF, elevation of cerebrovascular resistance (CVR), cerebral vasospasm for the duration of the study (150 minutes), and poor survival. For animals receiving the treatment regime (administered approximately 25 minutes after the induced SAH), rCBF remained low, CVR was high, and cerebral vasospasm was persistent. Survival in this group was the same as that observed for the untreated animals. Simultaneous administration of sodium nitroprusside and phenylephrine was ineffective in improving rCBF, CVR, cerebral vasospasm, or survival after SAH. In the control group (receiving only the treatment and not an intracranial insult), rCBF was below resting levels both during and after therapy, indicating impaired cerebral autoregulation. (Neurosurgery, 5: 688--595, 1979).


Spinal cord injury in the monkey: rate of cord cooling and temperature gradient during local hypothermia.

We have investigated the effectiveness of surface cord cooling in reducing spinal cord temperature with respect to the rate of cooling and the temperature gradient within the spinal cord parenchyma. Another question of some practical importance if spinal cooling is to be used clinically is that of the temperature within the spinal cord as a function of the dura being intact or open. In five monkeys, a laminectomy was carried out at T-10 and an impact injury of 350 g-cm force was applied to the spinal cord with the dura intact. Hypothermic perfusion with Elliott's B solution (artificial cerebrospinal fluid) was started, and we measured temperatures in the spinal cord with a thermistor probe mounted on a stereotactic drive. A series of measurements were made with the dura intact and the measurements were then repeated with the dura open. For comparison, we also recorded temperatures in one animal that had not been cord-injured. The rate of cord cooling was rapid during the first 3 minutes of hypothermic perfusion, after which there was a slight further reduction in cord temperature; a low level plateau of 6.7 degrees C was reached within 21 minutes after the start of cooling. The temperature gradient at varying depths of the spinal cord was approximately 6 degrees C (3.8 degrees C at the posterior surface to 10.1 degrees C in the deepest portion of the spinal cord), representing a temperature gradient of 1.3 degrees C/mm of cord tissue. Transmission of the cooling effect from perfusate to the spinal cord was not appreciably affected by the dura being intact or open. (Neurosurgery, 5: 583--587, 1979).


[Adrenergic activity and glycometabolic compensation in patients with diabetes mellitus].

In an assessment of the degree of adrenergic activity in the course of diabetes mellitus, plasma levels and urinary excretion of norepinephrine and epinephrine were determined in 20 normal subjects and 47 diabetics: 11 in good control (group I), 23 in poor control (group II), 13 with frank ketoacidosis (group III). The study was repeated in groups II and III once good glycometabolic control had been achieved. Slightly above normal catecholamine levels were noted in group I, while there was a marked increase in group II. Group III shaved an enormous increase by comparison with the other two groups. After medical treatment values in group III fell to within the group I range. The conclusion is drawn that a close relationship exists between adrenergic acitivity and the degree of control of diabetes. The sympathetic nervous system, therefore, interferes in the course of diabetes with blood sugar control via numerous, complex mechanisms.


[Unusual CT skull findings after preventive CNS treatment of acute leukemia in children].

CT examinations of the cranium were carried out among 15 children who had previously received cranial radiation and i.th. methotrexate during leukemia management. Surprisingly, 10 of 15 patients had abnormal CT findings. Only 2 of the 10 "CT-positive" children were clinically-neurologically conspicuous. The visible CT alterations of brain structure seemed especially marked and frequent the more time had elapsed since CNS-treatment. The most striking CT pathologica were found among children up to 5 years of age, who were also conspicuous through convulsions and delayed development.


[Cis-diamminedichloroplatinum(II): a new type of cytostatic].

Cis-diamminedichloroplatinum(II) (DDP) represents a new class of platinum compounds with cytostatic activity. Although the exact mechanism of action remains unknown, it is the most widely studied of these agents to date. The toxicology, metabolism, mode of application and clinical experience with this drug are presented and discussed. The value of DDP as monotherapy as well as in combination with other cytostatic agents, especially in the treatment of testicular cancer, as well as the possibilities of controlling its nephrotoxic effects are presented in greater detail.


Pseudophakia in children: a review of results of eighteen implant surgeons.

Intraocular lenses are a wise choice in a limited number of traumatic cataracts. It is necessary, however, to evaluate the patient very closely preoperatively to be assured that preoperative problems associated with increased postoperative complication are not present. In the proper patient, these authors feel that implant surgery is indicated. It offers a satisfactory alternative to the occasional patient that would have a functionless or amblyopic eye with a contact lens. Although the patient with a contact lens may see well with the contact in place, many are not able to wear the contact lens long enough during the day to consider it a functional success. These authors stress the use of a lightweight two-loop iridocapsular lens with one stage surgery and a short interval between the development of the cataract and the operation. Contact lenses or aphakic glasses are safe and will suffice with bilateral congenital cataracts. At the present time, further experimentation is necessary to determine if intraocular lens placement in the two-month-old infant with a unilateral congenital cataract will be safe and wil restore vision.


New findings in the chromosome 13 long-arm deletion syndrome and retinoblastoma.

New clinical and pathologic findings in patients with deletion of the long arm of chromosome 13 (13q-) include optic nerve hypoplasia and retinal dysplasia. Fibroblasts derived from patients with a 13q- syndrome with and without retinoblastoma, as well as from familial and sporadic retinoblastoma, are a useful model for the study of genetic susceptibility to the development of spontaneous and radiation-induced cancers. Fibroblasts from patients with hereditary retinoblastoma appear more radiosensitive than fibroblasts from patients with sporadic retinoblastoma or normal control patients.


Ocular asymmetry measuring device.

An instrument that measures ocular, eyebrow, canthal, and lower eyelid asymmetries accurately is useful for evaluating various deformities before oculoplastic surgery is performed. The ocular asymmetry measuring device comprises a headband, a ruler, and a T-shaped crosspiece. When the band is placed around the patient's head at forehead level, it fixes the ruler vertically over the midforehead. The metal rod is aligned with whatever eyelid, eyebrow, eye, or canthus is lower and is then elevated until it transects a similar structure on the opposite side. The degree of asymmetry is measured in millimeters. The device is useful in determining the degree of correction needed in various conditions that result from orbital fracture, facial paralysis, and congenital anomalies.


[A new method for extraction of cartilage proteoglycans: the electrical extraction (author's transl)].

Sections (40 mu thick) or fine powder of baboon articular cartilage were submitted to electric current (40-60 V/cm) in a free zone electrophoretic system and the extraction of proteoglycans from cartilage was followed by histochemical and biochemical methods. An extraction of about 40 per cent of the total hexuronic acid was obtained in 5 hours. The metachromasia showed that the proteoglycans resistant to electrical extraction are found in the chondrocytes lacunae and in the calcified zone. Gel electrophoretic studies showed the absence of proteoglycan aggregates and a material with a migration similar or a little faster than that of proteoglycan subunits. In some experiments a material with the migration of chondroitin sulphate was found. The electrical extraction could give information about the relationship between collagen framework and proteoglycans in the cartilage matrix itself and about proteoglycan organization.


Non-toxigenic Corynebacterium diphtheriae causing subacute bacterial endocarditis: case report.

This is the case report of a 13-yr-old European child from a boarding school at Herberton, on the Atherton Tableland, who developed subacute bacterial endocarditis, with 6 blood cultures at different times growing a non-toxigenic strain of Corynebacterium diphtheriae.


Monkeys show an oblique effect.

Monkeys aligned a cursor bar with high-contrast square-wave gratings presented in a variety of orientations. Alignment time increased with increasing spatial frequency from 6 to 24 cycles deg-1 regardless of the orientation of the grating. At higher spatial frequencies, alignment tasks took longer for obliquely oriented gratings than for horizontal and vertical ones. Reducing grating contrast by blurring the image of the 24 cycle deg-1 grating also produced longer alignment times for the obliques. These data indicate that monkeys have an oblique effect similar to that found in humans, implying that the monkey is a useful animal model for investigating the development of meridional anisotropies.


Parameters of the static burst discharge of lingual cold receptors in the cat.

Thermal stimuli were applied to the upper surface of the tongue of the cat. The stimuli ranged from 40 degrees C to 10 degrees C and were changed in cold steps of 5 degrees C, each temperature lasting 2 min. Afferent impulses of single specific cold fibers from the lingual nerve were analysed by a computer program. About 90% of the fibers showed bursts under static conditions. The bursts began as doublets at the temperature of maximal average frequency. This temperature varied from 40 degrees C to 15 degrees C in different fibers, the average being 30 degrees C. The parameters burst period, burst duration, pause duration, intraburst interval and spikes per burst increased monotonically from 30 degrees C to 15 degrees C. The possible physiological significance of the burst pattern is discussed.


[Discrepancies between TRH test and classical dynamic thyroid tests results in hyperthyroidism. 47 cases (author's transl)].

We have investigated the frequency of discordant results between the TRH test and classic dynamic tests of thyroid function (thyroid suppression and TSH stimulation tests) for patients presenting a diagnostic problem for hyperthyroidism. 12 patients in group I posed the problem of having a relapse of Graves' disease previously treated: a discrepancy between TRH and T3 suppression test results was observed in 17% of the cases. 10 patients in group II demonstrated the ophtalmopathy of Graves' disease without hyperthyroidism: discordance between tests results in this group was present for 20%. Finally, 25 patients in group III had a "hot" thyroid nodul apparent at thyroid scan: in 40% of the cases, the response to TRH did not lead to the same diagnosis that was suggested by the classical dynamic tests of thyroid regulation. The discrepancies observed in this work, between the results of the TRH test and those of classic dynamic tests, demonstrate that this two types of tests are not completely interchangeable, because they do not reflect exactly the same function.


[Franklin's disease associated with chronic active hepatitis and hypothyroidism. One case (author's transl)].

The authors report on a new case of Franklin's disease; the originality of which lies in the fact that it was associated with hypothyroïdism and mainly with B virus chronic active hepatitis. It seems likely that chronic antigenic stimulation during active hepatitis played role in the pathogenesis of the monoclonal gammapathy.


[Strategy for the diagnosis of thyrotoxicosis (author's transl)].

A study carried out on 808 patients examined because hyperthyroidism was suspected has shown that the most discriminating thyroid test is the free thyroxin index (FT4) in the plasma. For about 70% of the patients the comparison between the clinical diagnosis made by a clinician at his first interview and the results of FT4, leads one to an accurate assessment of the thyroid function. For the remaining 30% of the patients the assay of triiodothyronin (T3) in the plasma is the best laboratory test; it enables a diagnosis in 20% of those patients. It is therefore only in about 10% of the patients that more sophisticated laboratory tests would be necessary, such as TRH stimulation test and a technetium uptake whenever a scintigraphy is performed. Scintigraphy with technetium is only required to look for a possible toxic adenoma. In summary such a decision tree makes it possible to reduce considerably the cost of the diagnosis.


Filter replicas and permanent collections of recombinant DNA plasmids.

A permanent, ordered collection of 23,000 recombinant DNA plasmids containing Drosophila melanogaster DNA has been established. Simple and practical methods for storing and manipulating this collection were developed. In addition, an improved, simple and inexpensive method for making paper filter replicas of such an ordered collection and of a high density (10,000 colonies/petri dish) unordered collection was developed. These filter replicas are suitable for nucleic acid hybridization screens of recombinant DNA colinies and each filter replica can be used for many (greater than 5) successive screens. The kinetics of this hybridization reaction were examined and allow design of experiments that detect colony complementarity to a nucleic acid that is 0.5% of the hybridization probe.


Sequence and secondary structure of Drosophila melanogaster 5.8S and 2S rRNAs and of the processing site between them.

Drosophila melanogaster 5.8S and 2S rRNAs were end-labeled with 32p at either the 5' or 3' end and were sequenced. 5.8S rRNA is 123 nucleotides long and homologous to the 5' part of sequenced 5.8S molecules from other species. 2S rRNA is 30 nucleotides long and homologous to the 3' part of other 5.8S molecules. The 3' end of the 5.8S molecule is able to base-pair with the 5' end of the 2S rRNA to generate a helical region equivalent in position to the "GC-rich hairpin" found in all previously sequenced 5.8S molecules. Probing the structure of the labeled Drosophila 5.8S molecule with S1 nuclease in solution verifies its similarity to other 5.8S rRNAs. The 2S rRNA is shown to form a stable complex with both 5.8S and 26S rRNAs separately and together. 5.8S rRNA can also form either binary or ternary complexes with 2S and 26S rRNA. It is concluded that the 5.8S rRNA in Drosophila melanogaster is very similar both in sequence and structure to other 5.8 rRNAs but is split into two pieces, the 2S rRNA being the 3' part. 2S anchors the 5.8S and 26S rRNA. The order of the rRNA coding regions in the ribosomal DNA repeating unit is shown to be 18S - 5.8S - 2S - 26S. Direct sequencing of ribosomal DNA shows that the 5.8S and 2S regions are separated by a 28 nucleotide spacer which is A-T rich and is presumably removed by a specific processing event. A secondary structure model is proposed for the 26S-5.8S ternary complex and for the presumptive precursor molecule.


Sequences of large T1 ribonuclease-resistant oligoribonucleotides from protamine mRNA: the overall architecture of protamine mRNA.

Limited T1 ribonuclease digestion of the family of protamine mRNA's purified from rainbow trout testis yields several large oligoribonucleotide fragments ranging in size from 12--54 nucleotides in length. Several of these fragments purified by two dimensional gel electrophoresis contain several G residues and must represent nuclease-resistant, base-paired regions of the mRNA. Sequence analysis of these oligonucleotides by the method of Simoncsits, A., Brownlee, G.G., Brown, R.S., Rubin, J.R. and Guilley, H. (1977) Nature 269: 833-836, shows that these oligoribonucleotides arise from the 5'- and 3'-non-coding regions of the mRNA. Comparisons of the sequences of the large RNA fragment with DNA sequences obtained after cloning double-stranded protamine cDNA in the plasmids pBr322 and pmB9 show precise correspondence of a 54 nucleotide RNA fragment with positions 49--100 from the 3'-poly(A) tract and extending to within 5 nucleotides of the termination codon. Two other RNA fragments of 21 and 25 nucleotides in length arise from the 5'-non-coding region of the message and possess an AUG-sequence at their 3'-termini which is the initiation codon. The presence of distinct by homologous sequences in several sets of large RNA fragments is consistent with the presence of several closely related protamine mRNA's.


Presence of two DNA polymerases in Tetrahymena pyriformis.

Two DNA polymerases were detected in Tetrahymena pyriformis, strain GL. One (enzyme I) was sensitive to N-ethylmaleimide, while the other (enzyme II) was insensitive. The molecular weight of the enzymes, as determined by glycerol gradient centrifugation analysis, were approximately 130,000 and 70,000, respectively. Optimal concentration of MgCl2 was 10mM for enzyme I and 18mM for enzyme II. KCl inhibited enzyme I but stimulated enzyme II. Poly (dA-dT) served effectively as a template for enzyme I, while poly(dA).(dT)12-18 was an effective template for enzyme II. Enzyme I activity increased with cell growth and sharply declined after the cells reached the stationary phase. On the other hand, enzyme II activity appeared only at the end of log phase. In cells synchronized by starvation-refeeding technique enzyme I was markedly stimulated in correspondence to the rate of DNA synthesis, whereas the level of enzyme II activity changed to lesser extent. By ethidium bromide treatment, only enzyme I activity was induced.


[Investigation on the postoperative behavior of plasma amino acids in metabolically healthy patients. 1st communication (author's transl)].

In 12 patients before and after vaginal hysterectomy the plasma amino acid levels were determined. Without parenteral feeding the changes in plasma amino acid patterns can be explained by effects of operation and anaesthesia alone. The branched-chain amino acids decreased after operation. The following rise was never exceeding the control level. Even without substitution the concentrations of phenylalanine, methionine, and glutamic acid were increased. Tyrosine concentration remained within normal levels while cystine fell significantly.


[Insulin secretion in rats after hypothalamic damage].

Experiments conducted on female Wistar rats showed that 24 hours after the injury of the ventromedial nuclei of the hypothalamus (VMNH) without animal starvation there occurred a slight reduction of insulin in the islets and a significant elevation of the blood immunoreactive insulin (IRI) level, without any glycemia reduction. In animals with intact VMNH glybenclamide produced no changes in the insulin depot in the pancreatic cells, but somewhat increased the IRI level. However, after the VMNH injury glybenclamide caused a sharp insulin depletion in the islets, and a marked elevation of IRI and a decrease of sugar in the blood.


Distinctive nucleotide sequences of promoters recognized by RNA polymerase containing a phage-coded "sigma-like" protein.

We report the nucleotide sequences of two promoters for bacteriophage SP01 "middle" genes. These promoters are recognized by a modified form of Bacillus subtilis RNA polymerase that contains a phage-coded "sigma-like" regulatory protein (gp28) in place of the bacterial sigma factor. Both promoters shared the identical hexanucleotide 5'A-G-G-A-G-A at about 35 base pairs preceding the start point of transcription and the identical heptanucleotide 5'-T-T-T-A-T-T-T (T is the thymine analog 5-hydroxymethyluracil in SP01 DNA) located about 10 base pairs preceding the transcriptional start point. The significance of these sequences in comparison with nucleotide sequences of promoters recognized by sigma-containing RNA polymerases is discussed.


Altered promoter selection by a novel form of Bacillus subtilis RNA polymerase.

Bacillus subtilis RNA polymerase holoenzyme prepared by several standard methods utilizes bacteriophage T7 DeltaD111 DNA as an efficient template. The major RNA products are specific transcripts from T7 promoters A(1) and C; these promoters are also efficiently utilized by RNA polymerases purified from a wide range of other bacterial species [Wiggs, J., Bush, J. & Chamberlin, M. (1979) Cell 16, 97-109]. In contrast, B. subtilis RNA polymerase preparations purified by a modification of the method of Burgess and Jendrisak (designated fraction 5) utilize T7 DeltaD111 promoters A(1) and C and an additional promoter site, J, which has been located at 90.6% on the standard T7 physical map. This promoter is not used by B. subtilis core RNA polymerase or by RNA polymerase from any other bacterial species we have tested. Sodium dodecyl sulfate/polyacrylamide gel electrophoresis of fraction 5 RNA polymerase shows that it contains B. subtilis components sigma and delta and a polypeptide of M(r) 92,000 in addition to the B. subtilis beta, beta', and alpha subunits. Chromatography of fraction 5 on single-stranded DNA-cellulose gives an enzyme fraction, Bs I, that is indistinguishable from B. subtilis RNA polymerase holoenzyme both in its peptide composition (betabeta'alpha(2)sigma) and in the selective transcription of only T7 RNAs A(1) and C. Chromatography of fraction 5 on phosphocellulose yields an enzyme fraction, Bs II, devoid of sigma subunit but containing the M(r) 92,000 peptide and traces of delta. This fraction synthesizes predominantly T7 J RNA in vitro together with traces of T7 A(1) and C RNAs. Hence, B. subtilis RNA polymerase fraction Bs II appears to contain a form of RNA polymerase that can transcribe selectively without detectable amounts of B. subtilis sigma subunit and that utilizes a promoter site not used by other known bacterial RNA polymerases. The structural basis for this specificity is not yet known.


Extracts of Drosophila embryos mediate chromatin assembly in vitro.

Extracts of Drosophila embryos can mediate the assembly of a chromatinlike structure from histones and DNA under physiological conditions. The histone-DNA complex formed in vitro contains micrococcal nuclease-sensitive sites spaced at 200-base pair intervals. More extensive digestion of the complex by micrococcal nuclease generates 11S particles which cosediment with nucleosome core particles isolated from native chromatin. These particles contain 140-base pair DNA fragments which upon further cleavage with micrococcal nuclease give rise to a pattern of discretely sized DNA fragments characteristic of nucleosome core particles. We have assayed the chromatin assembly process both qualitatively by measuring the induction of supertwists into a relaxed circular DNA (a process requiring a nicking-closing enzyme) and quantitatively by measuring the formation of micrococcal nuclease-resistant DNA fragments from radioactively labeled linear DNA. The amount of chromatin formed depends primarily on the amount of histones, whereas the rate of assembly depends on the amount of extract protein added. The factors in the extract that mediate chromatin assembly appear to interact first with the DNA because preincubation of the DNA with the extract markedly increases the extent of assembly.


Evidence for hydrophobic region within heavy chains of mouse B lymphocyte membrane-bound IgM.

The gel filtration behavior, in the presence of detergents, of membrane-bound IgM from normal mouse spleen B lymphocytes was compared to that of secretory IgM from mouse plasma cells. The proteins were labeled either by surface radioiodination or biosynthetically with radioactive amino acids. Cell lysates were fractionated on calibrated Sepharose 6B columns in the presence of the detergents Nonidet P-40 or deoxycholate. Eluted fractions were immunoprecipitated and the reduced or unreduced precipitates were analyzed by sodium dodecyl sulfate gel electrophoresis followed by radioautography. Surface (125)I-labeled 8S IgM exhibited a gel filtration pattern in Nonidet P-40 corresponding to much higher apparent molecular weight than that of secretory 8S IgM, a difference that almost disappeared when gel filtration was performed in the presence of deoxycholate, which forms much smaller micelles than does Nonidet P-40. Biosynthetically labeled lymphocytes contain two types of IgM molecules differing in their gel filtration behavior and fate: one identical to secretory 8S IgM of plasma cells and secreted in the medium during chase periods, and the other identical to surface (125)I-labeled IgM and remaining cell-associated. Because the surface-bound 8S IgM was not found to be associated with other labeled molecules, it is likely that the detergent-binding behavior of surface IgM is due to a hydrophobic segment carried by these Ig molecules. That lymphocytes synthesize two types of mu chains was also shown by the use of tunicamycin, an inhibitor of glycosylation. In its presence, two unglycosylated mu chains were observed: one identical in size to that made by tunicamycin-treated plasma cells, and the second slightly larger. Gel filtration in Nonidet P-40 of the cell lysates of tunicamycin-treated lymphocytes showed that the nonsecretory 8S IgM contains this second type of mu chains, whereas the IgM molecules of the secretory type contain plasma cell-like mu chains. It is suggested that membrane IgM mu chains contain a hydrophobic segment which is responsible for its association to the membrane.


Attenuation in the Escherichia coli tryptophan operon: role of RNA secondary structure involving the tryptophan codon region.

The secondary structure of the terminated trp leader transcript from Escherichia coli was analyzed by RNase T1 partial digestion. Base-paired regions were recovered by nondenaturing gel electrophoresis and identified by denaturing gel electrophoresis and fingerprinting. The tandem tryptophan codons in the leader peptide coding region were found to be base paired with a more distal region of the transcript. This and other secondary structures that the trp leader RNA can form help explain the physiological response of the operon as well as the behavior of regulatory mutants.


Termination of transcription in nucleoli isolated from Tetrahymena.

Correct termination of transcription of the rRNA gene in nucleoli isolated from Tetrahymena is dependent on a protein factor with a molecular weight between 50,000 and 100,000. At low ionic strength the endogenous RNA polymerase synthesizes a transcript identical in size to the precursor rRNA extracted from cells. In the presence of ammonium sulfate, however, the RNA polymerase reads through the normal termination point as demonstrated by size and hybridization studies of the transcript. After ammonium sulfate treatment, rDNA associated with chromosomal proteins (r-chromatin) can be separated from the termination factor by differential centrifugation. The endogenous RNA polymerase on the salt-treated r-chromatin is no longer able to recognize the normal terminator even at low ionic strength. Normal termination properties can be reconstituted by complementation with intact nucleoli or with a protein factor extracted from nucleoli.


Amino acid sequence of an immunoglobulin-like HLA antigen heavy chain domain.

The classical human transplantation antigens, derived from the HLA-A, -B, and -C loci, are cell-surface-expressed glycoproteins. On the exterior of the cell the transplantation antigen heavy chain exposes two disulfide-containing domains and a glycosylated NH2-terminal extension. The disulfide-containing domain closest to the membrane has been isolated and its amino acid sequence has been determined. The HLA antigens used for the sequence analysis were derived from two and possibly three loci and comprised several allelic forms. The primary structure was remarkably invariant, and amino acid variations were observed only at three positions. Whether this suggests that the allelic variation of the HLA antigens is preferentially confined to other regions of the molecule or is a result of fortuitous selection of peptides remains to be established. The sequenced portion of the HLA antigen heavy chain is as homologous to beta 2-microglobulin and immunoglobulin light and heavy chains as are the latter to one another. This observation strengthens the notion that the transplantation antigens and the immunoglobulins are evolutionarily related.


Effect of interchain disulfide bond on hapten binding properties of light chain dimer of protein 315.

The hapten binding characteristics of the covalent light chain dimer, derived from the murine IgA secreted by plasmacytoma MOPC-315, to two nitroaromatic compounds, epsilon-N-(2,4-dinitrophenyl)-L-lysine and 4-(alpha-N-alanine)-m-nitrobenz-2-oxa-1,3-diazole, were investigated by differential spectroscopic titrations. The binding curves for both haptens were found to display sigmoidity similar to that reported earlier for the reduced and alkylated dimer held together by noncovalent bonds only. However, the presence of the interchain disulfide bond in the covalent dimer was found to cause marked changes in its binding properties. The data, like those obtained for the noncovalent dimer, fit the allosteric model of Monod, Wyman, and Changeux in which binding of the first hapten to the dimer causes a conversion of both sites of the protein molecule from a lower to a higher affinity conformation. However, the binding parameters show that both the affinity and the positive cooperativity in the interaction between haptens and the covalent dimer are significantly enhanced. The differences in the parameters of the binding and of the allosteric transition caused by the presence of the interchain disulfide bond demonstrate the existence of longitudinal interactions in immunoglobulin derivatives. These properties of the light chain dimer make it a potential model for the receptors present on thymus-derived lymphocytes.


A practicable immunological approach to block spermatogenesis without loss of androgens.

The intrinsic capacity of the immune system to elicit immune response selectively against late developing sperm proteins has been mobilized to intercept spermatogenesis. Bacillus Calmette-Guérin given in appropriate doses intratesticularly is effective in bringing about this effect. In dogs and rhesus monkeys, the sperm count in the semen declined precipitously, and almost complete azospermia was attained in 4-6 weeks after immunization. The few sperm cells that were present were immotile. Examination of serial sections of testes in immunized rats showed about 98% of the tubules to be devoid of sperm. The tubules were partially or fully atrophied. The basement membrane was, however, intact and the pertubular cell layer was normal. Sertoli cell nuclei were apparently normal but the cytoplasm was vacuolated and, in most cells, partially disintegrated. The lumen of the tubules was exhausted of formed elements and at times filled with eosinophilic debris. Leydig cells were present and hyperplasia of interstitial cells was seen, with massive infiltration of leukocytes. Blood testosterone levels were in the normal range and Leydig cells were responsive to gonadotropins. Libido was intact. The method was applicable to a variety of mammalian species. The implications of the results are discussed.


Neoplastic transformation of epithelial cells in whole mammary gland in vitro.

Biological characteristics of nodule-like alveolar lesions (NLAL) induced by 7,12-dimethylbenz[a]anthracene (DMBA) in organ culture of whole mammary gland (BALB/c female mice) were assessed after transplantation into gland-free mammary fat pads of syngeneic virgin mice. (i) Tissue-fragment explants from NLAL areas of the gland produced abnormal lobuloalveolar (LA) outgrowths in 3 of 10 fat pads. (ii) Transplantation of dissociated cells of NLAL-derived LA outgrowths into 36 fat pads showed 100% LA outgrowths and 3 (8%) of these 36 outgrowths produced mammary carcinomas. (iii) The explants of dissociated cells from whole mammary glands treated with DMBA in culture produced full or partial LA structures in 2 of 56 outgrowths. (iv) The explants of dissociated cells prepared from outgrowths derived from outgrowths derived from explants as in iii produced 9 LA outgrowths in 16 instances; mammary tumor incidence in these outgrowths was 3 of 16 (18%). (v) The explants of tissue fragments from LA outgrowths as in iv produced LA outgrowths in 20 of 20 fat pads; mammary carcinomas appeared in 16 of 20 (80%) of these outgrowths. No NLAL was detectable in control glands treated with dimethyl sulfoxide (solvent for DMBA); explants of the control glands consistently produced ductal outgrowths and no tumor. This accomplishment of chemical carcinogen-induced neoplastic transformation of epithelial cells in vitro provides a model for studying carcinogenesis in an entire isolated organ.


Retinoid prevents mammary gland transformation by carcinogenic hydrocarbon in whole-organ culture.

The mouse mammary gland in whole-organ culture, an in vitro system that is capable of alveolar development, differentiation, involution, and oncogenic transformation, has been used to examine the effects of the retinoid 2-retinylidene-5,5-dimethyl-1,3-cyclohexanedione (retinylidene dimedone) on epithelial transformation by a low concentration (10 nM) of the carcinogen 7,12-dimethylbenz[a]anthracene. The retinoid significantly prevented mammary gland transformation only when administered after the carcinogen. In addition, the phenotypes of the early transformed state of the mammary gland were suppressed for 20 days after removal of the retinoid. The retinoid was effective during both mammary alveolar development and regression in culture at concentrations as low as 1 nM, and itself had no significant transforming or cytotoxic activity. Mammary glands treated with both the carcinogen and the retinoid resembled, at the microscopic level, those given the solvent (dimethyl sulfoxide) only. The mouse mammary gland in whole-organ culture provides a promising model system in which to study the actions by which retinoids prevent and suppress the chemical transformation in vitro and oncogenesis in vivo of epithelial cells in general and of mammary gland in particular. The present findings support the suggestion that a search for suitable retinoids as chemopreventive agents against human breast cancer is warranted. This model system may be useful as initial indicator in that search.


Effect of glucose/sulfonylurea interaction on release of insulin, glucagon, and somatostatin from isolated perfused rat pancreas.

The effect of a sulfonylurea, glibenclamide, on the release of insulin, glucagon, and somatostatin was studied in the isolated perfused rat pancreas. At glucose concentrations of 1.1 mM or less, the drug stimulated somatostatin release, whereas glucagon release, after 2-3 min of increase, was markedly inhibited. Insulin release was moderately stimulated, and maximal release occurred relatively late. A moderate glucose load (6.7 mM) inhibited glibenclamide-induced release of somatostatin, whereas the two in combination exerted an additive action on insulin release. Greater glucose loads, which by themselves would stimulate somatostatin release, only marginally suppressed glibenclamide-induced somatostatin release. The insulinogenic effect of these glucose levels was not modified by glibenclamide. Glibenclamide may thus stimulate both the alpha and beta as well as delta cells of the pancreas, depending on glucose concentration. We suggest a paracrine (local) interaction of somatostatin with the alpha and beta cells, which has an important role in the kinetics of insulin and glucagon release induced by sulfonylureas.


Biochemical and morphologic studies on diabetic rats: effects of sucrose-enriched diet in rats with pancreatic islet transplants.

Isolated pancreatic islets were administered to Lewis rats with streptozotocin-induced diabetes. Then the rats were fed either a semisynthetic diet containing 60% (wt/wt) sucrose for 3 weeks or were continued on chow. Transplantation resulted in a decrease in serum glucose, an increase in serum insulin, and a marked decrease in serum triacylglycerol, particularly in the sucrose-fed diabetic rats. In these rats, in demarcated areas of hepatocytes surrounding portal vein termini, lipid was deposited in the cytosol and large lipoprotein particles engorged the Golgi apparatus, Golgi-derived secretory vacuoles, and GERL. This model permits observation of the effects of pancreatic islet hormones on lipogenesis by hepatocytes in situ.


Membrane potential changes caused by thyrotropin-releasing hormone in the clonal GH3 cell and their relationship to secretion of pituitary hormone.

Effects of thyrotropin-releasing hormone (TRH; thyroliberin) on membrane electrical properties were studied in the clonal rat anterior pituitary cell (GH3) by continuous recording of the intracellular potential. Application of TRH, which stimulates the release of prolactin and growth hormone from the GH3 cell, elicited a transient hyperpolarization of the cell membrane followed by an enhancement of the generation of action potentials for an extended period in the majority of cells tested. The transient hyperpolarization was due to an increase of the membrane conductance to K+. The enhancement of the spike generation was not due to membrane depolarization. The input resistance of the cell membrane was found to be increased during the facilitation. Thus the mechanism of the facilitatory action of TRH is different from the mechanisms of conventional excitatory neurotransmitters. TRH enhances the spike generation, thus promoting Ca2+ entry from extra- to intracellular space (the action potential of the GH3 cell has a Ca2+ component) and stimulating the release of hormones. This notion is supported by the observation that cobalt ions, which block the calcium spike in these cells, completely abolished the stimulatory effect of TRH on the release of prolactin and growth hormone.


Small circular DNA of Drosophila melanogaster: chromosomal homology and kinetic complexity.

Nucleic acid reassociation techniques were used to determine the kinetic complexity of small circular DNA in cultured cells of Drosophila melanogaster. Two kinetic components are present. One of these constitutes 82% of the mass of the circular DNA and has a complexity of 1.8 x 10(4) nucleotide pairs; the other constitutes 18% of the mass and the a significantly higher but undefined sequence complexity. We have demonstrated that these circular molecules hybridize to middle repetitive chromosomal sequences by hybridization of in vitro-labeled circular DNA tracer with a vast excess of Drosophila chromosomal DNA. Thermal stability measurements indicate that base-pair mismatch between small circular DNA and middle repetitive chromosomal DNA does not exceed 2%. We discuss possible functions of these small circular DNAs in light of the above findings.


Removal of an adenine-like molecule during activation of dinitrogenase reductase from Rhodospirillum rubrum.

During the activation of the inactive dinitrogenase reductase from Rhodospirillum rubrum, an adenine-like molecules is lost and phosphate is found on both active and inactive forms of the protein. ATP and divalent metals are required for activation of the reduced protein, but ATP is not required for activation of phenazine methosulfate-oxidized dinitrogenase reductase. Snake venom diesterase and spleen diesterase have no effect on the inactive protein; alkaline phosphatase removes phosphate from the activated protein but not from the inactive protein. ATP binds to both active and inactive forms of the protein.


Energetics of rapid transmembrane movement and of compositional asymmetry of phosphatidylethanolamine in membranes of Bacillus megaterium.

The energy requirements for the rapid transmembrane movement of phosphatidylethanolamine in membranes of Bacillus megaterium KM have been investigated by means of pulse label experiments. The transmembrane movement continues at a high rate in cells blocked in the production of metabolic energy by treatment with a combination of inhibitors. The movement is shown to be completely independent of the synthesis of lipid and of protein and, more generally, independent of sources of metabolic energy. The rate constant ki, defined as the fraction of the internal phosphatidylethanolamine that exchanges with the external layer of the membrane per unit time, has been found to have a value of about 0.1 per min. The compositional asymmetry of phosphatidylethanolamine in membranes of B. megaterium persisted, and indeed was somewhat enhance, in energy-poisoned cells under conditions in which rapid mixing of inner and outer layers was taking place. Therefore, the compositional asymmetry is not maintained by kinetic barriers to transbilayer exchange or by expenditure of metabolic energy. It must be an equilibrium condition, and presumably reflects the differential binding of phospholipids by proteins and other ligands on the two sides of the membrane.


Middle repetitive DNA: a fluid component of the Drosophila genome.

Most of the middle repetitive DNA of Drosophila melanogaster appears to be organized into families of 10-100 repeated elements that are found at scattered locations in the chromosome arms and occupy new chromosomal positions as populations of D. melanogaster diverge. These "nomadic" DNA segments can be identified by an analysis of cDm plasmids, hybrids of ColE1 and segments of randomly sheared D. melanogaster DNA. Eighty cDm plasmids were withdrawn, at random, from a library of approximately 17,000 cDm clones. Fifty-seven of these seem to contain either DNA that is not repeated in the D. melanogaster genome or DNA that has a low repetition frequency. The remaining 23 cDm plasmids contain repetitive sequences. Seventeen of these 23 plasmids contain repetitive sequences that are demonstrably scattered to many chromosomal sites that can be mapped in two D. melanogaster strains, g-1 and g-X11. The repeated elements hybridizing with each of the different Dm segments are at quite different chromosomal locations in these two strains. However, the size of each family of repeated sequences remains fairly constant in both strains. It is proposed that the number of elements in each family has been fixed by selection.


Identification of chorion protein precursors and the mRNAs that encode them in Drosophila melanogaster.

Specific antisera were generated for major size classes of Drosophila chorion proteins. These antisera were used in conjunction with cell-free translation of follicular RNA to identify precursors, containing signal peptides, for chorion components A1, A2, B1, and B2. An additional precursor cross-reacts with anti-B antisera, although its product appears to correspond to a protein distinct from authenic B proteins. The size classes of mRNA encoding A and B protein precursors have been identified by cell-free translations.


Reorganization of actin in platelets stimulated by thrombin as measured by the DNase I inhibition assay.

The effect of thrombin stimulation on actin organization in human platelets has been analyzed by using the DNase I inhibition assay, which is selective for unpolymerized and filamentous actin. The results provide biochemical evidence for the suggestion that stimulation leads to rapid polymerization of actin. The measurements also reveal changes in the polymerization state of actin occurring after cell lysis. These changes are influenced by the concentration of free calcium in the extracts.


Genetic complementation studies of multiple sulfatase deficiency.

Cultured fibroblasts from two individuals with multiple sulfatase deficiency (MSD) were found to have decreased activities of arylsulfatases (aryl-sulfate sulfohydrolase, EC 3.1.6.1) A, B, and C as well as iduronate-sulfate sulfatase, sulfamidase, and N-acetylglucosamine-6-sulfate sulfatase. The activity of N-acetylgalactosamine-6-sulfate sulfatase was decreased in one line but not in the other. Mixtures of MSD cell extracts with extracts from normal cells did not result in inhibition of normal sulfatase activities. Mixtures of MSD cell extracts with extracts of fibroblasts from patients with Hunter or Sanfilippo A syndrome did not activate iduronate-sulfate sulfatase or sulfamidase activity. Heterokaryons formed by fusion of MSD cells with Sanfilippo A fibroblasts demonstrated a partial correction of the enzyme deficiency. In similar manner, MSD-Hunter heterokaryons showed a significant increase in iduronate-sulfate-sulfatase activity. Genetic complementation in heterokaryons of MSD fibroblasts and cells of either Sanfilippo A or Hunter syndrome implies a genetic defect in MSD different from that causing specific sulfatase deficiencies.


Effects of acetone, methyl ethyl ketone and methyl isobutyl ketone on a match-to-sample task in the baboon.

Acetone, methyl ethyl ketone (MEK) and methyl isobutyl ketone (MIBK) were evaluated for effects on a delayed match-to-sample discrimination task in the juvenile baboon. The animals were exposed to 1/2 the threshold limit value (TLV) of each gas for 24 hr per day during a 7-day period. They were also exposed to a combination of MEK and MIBK at the same exposure concentrations. Each exposure condition affected accuracy of performance minimally but resulted in increased and decreased extra responses during the delay intervals. Response times were slowed under acetone, MEK or MIBK. In contrast to the effects of the individual gases, exposure to a combination of the same doses of MEK and MIBK produced a consistent increase in extra responses during delay and a concomitant decrease in response times. Changes in tissue uptake and metabolism are suggested as possible mechanisms to explain this observation.


Effects of cimetidine on the secretion of some pituitary hormones.

Cimetidine infused intravenously into 6 healthy volunteers did not induce significant changes in plasma levels of prolactin (hPRL), thyreotropin (hTSH), gonadotropin (hLH and hFSH) and growth hormone (hGH). Conversely it caused a significant increase in prolactin response to TRH without modifying the hTSH response to thyreotropin-releasing hormone (TRH) and gonadotropin response to gonadotropin-releasing hormone (GnRH). Data obtained in these experiments, together with data reported in the literature, suggest that the amplified prolactin response to TRH observed during cimetidine infusion, is likely to be connected with a blockade of H2-receptors rather than to unspecific actions of cimetidine.


Cholecystokinin suppresses sham feeding in the rhesus monkey.

The satiety effect of slow intravenous infusions of impure cholecystokinin (CCK) was investigated in 5 rhesus monkeys during sham feeding. CCK suppressed sham feeding. The dose for 50% inhibition of sham feeding was about 10 U/kg-hr; 20 U/kg-hr abolished sham feeding. No dose produced retching, vomiting, diarrhea or other behavioral signs of toxicity. These results demonstrate the potency of CCK for inhibiting feeding in the monkey when gastric, intestinal and postabsorptive mechanisms are not activated by ingested food.


[Continuing education through guidance--experiences with a continuing education programme related to practice, collected in a large psychiatric hospital (author's transl)].

The article reports on the setting-up of a continuing education programme related to practice, applicable in particular to nursing personnel of long-time wards in a large psychiatric hospital. The article describes the prerequisites of "continuing education within the framework of the hospital itself", organised in various sub-sections such as guidelines for group work with patients on the wards, and topic-centered continuing education groups for co-workers. The planning and execution of group work is demonstrated by means of model examples. The assumption that continuing education can help to change the atmosphere prevalent in wards and can also change the degree of activation of the patients, has been confirmed by the experience collected so far. This illuminates once again the need for practice-related continuing education an subject-specific further training for psychiatric nursing staff, even though in the long-term therapeutic field, possibilities of rehabilitation may probably gain more ground in psychiatric treatment of the future.


A comparative study of the portal vessels connecting the endocrine and exocrine pancreas, with a discussion of some functional implications.

We have examined the pattern of the capillaries of the pancreas in rabbits, rats, mice, guinea-pigs, cats and baboons, using arterial and venous injections of Berlin blue. In all these species we found extensive, direct connexions between the capillary beds of the islets and the exocrine tissue of the gland, forming a highly developed portal system. Some of the functional implications of these vascular connexions are discussed, particularly the influence of the islet hormones insulin, glucagon and somatostatin upon the exocrine cells.


Serum FSH, LH and testosterone in the male rhesus following prostaglandin injection.

Adult male rhesus were treated with PGE2, PGF2 alpha or the 13,14-dihydro-15-keto metabolite of PGE2 in a randomized crossover design. Serum concentrations of FSH, LH and testosterone were determined and compared to the respective values in the same uninjected animals. No significant changes were noted in controls or following the metabolite injection. FSH increased gradually for 4 hours after metabolite treatment. In contrast, injection of PGF2 alpha was followed by an abrupt (within 15 minutes) increase in LH and testosterone. FSH increased gradually in 2 of 3 treated animals. Injection of PGE2 was followed by a similar abrupt increase in LH concentration. This was not always associated with a significant increase in testosterone or FSH. These results demonstrate that injections of PGE2 or PGF2 alpha can change serum gonadotropin and testosterone concentrations in male rhesus monkeys, and that the effects of these two prostaglandins are qualitatively different.