Glutathione in rabbit corneal endothelia: the effects of selected perfusion fluids.

Although the ameliorating effect of glutathione on corneal deturgescence is known, its chemical mechanism is not understood. An endeavor toward the latter was made by perfusing freshly excised rabbit corneas with selected perfusion fluids, measuring corneal thickness, and assaying the endothelial cells for reduced and oxidized glutathione after 2 and 5 hr of perfusion. Ringer's solution, containing either lactate or bicarbonate, caused significant decreases in both forms of glutathione after perfusion. The corneas increased in thickness considerably during these periods. When 5 mM glucose was added to bicarbonate-Ringer's solution, the corneas swelled about half as much as before. However, glutathione levels were as depressed as with simple Ringer's fluid. Adenosine (0.5 mM) in the presence of glucose (bicarbonate-Ringer's) caused a further swelling decrease so that the corneas were maintained at near normal thickness. The levels of glutathione were 84% of control values compared to 35% to 45% for Ringer's solutions (+/- glucose). The addition of glutathione to glucose (bicarbonate-Ringer's) caused intracellular glutathione levels to be higher than control values while allowing minimal tissue swelling. Glutathione in combination with adenosine, glucose, and bicarbonate produced the highest intracellular glutathione levels and a slight corneal deswelling. After oxidation of intracellular glutathione with t-butyl hydroperoxide in glucose (bicarbonate-Ringer's), endothelial cells were destroyed within 1 hr. The oxidant, however, may have had a direct effect upon the endothelial cell membranes.


Effect of aging on horizontal smooth pursuit.

Quantitative infrared oculographic study of horizontal pursuit in young and elderly normal subjects showed significantly lower smooth pursuit velocities in the elderly when tracking triangular waveform targets of 20 degrees amplitude at velocities of 10 degrees/sec and over. Latencies for initiation of smooth eye movements were significantly prolonged in older subjects. The reduced velocity responses of the pursuit system indicate that the diagnosis of abnormal pursuit must be qualified by the age of the patient. Smooth pursuit is an age-dependent motor system.


Ocular retardation (or) in the mouse.

The ocular retardation (or) mutation in mice has been studied morphologically in serial 1 mu sections. This recessively inherited, fully penetrant mutation is characterized by an early arrest of retinal development, aplasia of the optic nerve, cataractous degeneration of the lens, and microphthalmia. We describe early alterations of normally occurring morphogenetic cell death in the optic cup and aberrations of optic fissure formation which appear to precede the arrest of retinal and optic nerve development. The subsequent disappearance of central retinal vessels and cataract formation are interpreted as secondary phenomena.


The use of resin-sprayed thin paper for urinary bladder regeneration.

Urinary bladder reconstruction using resin-sprayed thin paper was performed on four patients with either bladder cancer or tuberculosis. The paper was transurethrally removed after the bladder regenerated. Satisfactory results were obtained in three patients; the patient with a long standing tuberculous cicatrical contracted bladder, however, failed to regenerate the bladder with an adequate capacity.


Iontophoresis of vidarabine monophosphate into rabbit eyes.

In order to investigate the efficacy of iontophoresis for increasing the penetration of vidarabine monophosphate into the eye, tritium-labeled vidarabine monophosphate was applied to rabbit eyes by topical and iontophoretic application, and the penetration of the compound into the eye, and its subsequent metabolism, were studied. At 20 min after treatment, the ratios of radioactivity for cathodal iontophoresis compared to topical application alone were cornea 8.6, aqueous humor 4.8, and iris 2.4; for 60 min the ratios were cornea 12.2 aqueous humor 17.5 and iris 2.5. In addition, the acid-soluble components were extracted from the cornea and aqueous humor. Vidarabine monophosphate, vidarabine, hypoxanthine arabinoside, adenosine, hypoxanthine, and adenine from the acid-soluble fraction were separated by thin-layer chromatography. The amount of vidarabine monophosphate and vidarabine in the cornea and aqueous humor from the iontophoretically treated group was six to 15 times higher than from the group that received topical application of the drug. It was concluded that cathodal iontophoresis resulted in significantly increased penetration of the antiviral drug vidarabine monophosphate into the anterior chamber of the eye. The effects of iontophoresis of vidarabine monophosphate on corneal epithelium, as observed by scanning electron micrographs, were equal to or less than those seen with the topical application of widely used preservatives in ophthalmic preparations.


Soluble proteins of the rat prostate: electrophoretic separation.

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the soluble proteins of the rat ventral, lateral, and dorsal prostate showed characteristic patterns for each lobe. Protein content in the lobes also differed; the ventral prostate had a significantly greater concentration than the other two.


The microbial flora of the urogenital tract in women with symptoms of recurrent urinary tract infection. The non-influence of methenaminehippurate treatment on the idigenous flora.

Recurrent urinary tract infections are known to occur among 5 per cent of all females. These women frequently have episodes of symptoms of lower urinary tract infection even between periods of bacteriuria. In the present study, 25 women with a history of recurrent urinary tract infections, found to lack signs of obstructive uropathy, were subjected to an extensive urological and microbiological survey. The investigation showed that (i) "pyuria" was common (9/12) but usually of urethral origin, (ii) introital and/or urethral colonization with Enterobacteriaceae often (11/25) occurred, (iii) apart from Escherichia coli found in three patients, a Bacteroides species was isolated in two and ureaplasmas in one patient from suprapubically aspirated urine, and (iv) chlamydia, gonococci, and trichomonads were not found. The patients were given methenaminehippurate for 1 week and then reexamined. The treatment did not seem to influence the indigenous flora of the lower urogenital tract.


Attempted ureteral replacement and urinary conduit using bovine artery graft.

Ureteral replacement and urinary diversion using bovine carotid artery heterograft were attempted in dogs. The graft failed for several reasons: stasis proximal to an aperistaltic segment, anastomotic stricture, and fibrotic narrowing of the graft. The disease entities and criteria for successful ureteral replacement and diversion are reviewed.


The free peritoneal transplant as substitute for the urinary bladder wall.

In 13 rabbits the fundus of the bladder was resected and the defect repaired by a free peritoneal transplant from the lateral abdominal wall. One animal died postoperatively of purulent peritonitis. In the remaining animals the transplant healed with no signs of irritation. The mean reduction of bladder capacity per body weight between the 5th and 18th postoperative week was only 13 per cent. Histologic tests after 5 weeks showed a germinating epithelium on the transplant which was replaced by a fibromuscular lamina after 10 weeks. The successful results of these animal experiments seem to justify the clinical use of free peritoneal transplants. The good healing tendency and matrix function of this tissue permit transplantation of the peritoneum wherever intraoperative defects occur or suture dehiscence may be expected.


In vivo growth of human bladder cancer cell lines.

Two human bladder cancer cell lines grew predictably in rats immunosuppressed with antilymphocyte serum. Intraperitoneal  inoculation of tumor cell suspensions resulted in diffuse intraabdominal carcinomatosis with consequent host death after 10 to 20 days. Subcutaneous inoculation of tumor cell suspensions resulted in local tumors which grew exponentially for 20 to 30 days before eventual regression after 40 to 50 days; lung metastases developed in at least 13 per cent of the animals with subcutaneous tumors. The histologic appearance of the xenografted tumors closely resembled that of the original tumors. Subsequent in vitro culture of the xenografted tumors provided cell lines that were morphologically identical to the primary lines and that retained a human karyotype. It is proposed to employ this model of human bladder cancer to evaluate chemotherapeutic agents for possible use in the clinical disease.


An improved mechanical device for control of urinary incontinence.

Results of tests on implantable artificial sphincters with a subcutaneous control unit encased in a plastic envelope were previously reported. The plastic deteriorated and in 12 to 18 months caused instrument failure. To obviate this failure, (control) units of titanium alloy with protruding levers were tested in 17 animals for a period of up to 6 months to determine whether fibrosis and tissue ingrowth would hamper the function of the control levers. The device was placed around the urethra distal to the bladder neck. It was set to obstruct the urethra against pressures varying from 40 to 80 cm of water. Erosion of the urethra did not take place. In no instance was the action of the subcutaneous control levers hampered by tissue ingrowth or fibrosis.


Propranolol protection in acute renal failure.

Activation of the renin-angiotensin system has been implicated as one of the mechanisms involved in acute renal failure. Support of this hypothesis was forwarded by the finding that propranolol, a blocker of renin release, reduced the deleterious effect of ischemia on kidney function. The hypothesis was tested further in these experiments by studying renal blood flow after ischemic injury to rat kidneys with and without propranolol proection. Miniature electromagnetic flow probes measured blood flow after 70 min of total renal artery occlusion. Although brief infusion of propranolol reduced the degree of acute renal failure, it had no effect on renal blood reflow. The data do not support the hypothesis that the renin-angiotensin system plays a role in acute renal failure. Other explanations for the protective effect of propranolol are suggested.


Experimental use of fluoroalkyl cyanoacrilate in ureteral anastomosis.

A fluorinated tissue adhesive Fluoroalkyl Cyanoacrilate has been used in end-to-end ureteral anastomoses as an adjunct to suture material to avoid urinary extravasation in seven dogs. A similar number of dogs served as controls. The urinary tracts were evaluated grossly, radiographically, and histologically after 3 to 12 months. Better anatomical results and less inflammatory reaction and fibrosis were found in the group submitted to the tissue adhesive.


Human renal neuraminidase.

An assay technique for determination of renal neuraminidase (sialidase) activity is described. Consistent and reproducible results were obtained in studies of rat renal tissue. Neuraminidase activity was detected in all human renal specimens studied; however the degree of activity was not related to the presence of renal calculi or infection.


Vascularization of the ureter after experimental ureterolysis in rabbits.

The left ureter was isolated and its nutritive arteries interrupted in 43 rabbits. The blood flow in the isolated and in the control ureters was estimated intravitally by measuring the temperature in the wall of the ureters, and postmortally by counting the capillaries injected with India ink. The vascularization of the isolated ureter was lowered at 3 days after surgery and returned to normal values at 14 days.


Membrane characteristics of cultured endothelial cells: identification of gap junction.

Membrane characteristics of cultured endothelial cells derived from the superior vena cava of the rabbit were studied in freeze-fracture replicas. Gap junctions were identified, but tight junctions were not seen. In addition to pinocytic vesicles, fenestrations of plasma membrane which are not normally seen in the endothelium of vena cava in situ were found. This finding may be explained by the absence of platelets in the culture medium and is consistent with the current concept of endothelial-platelet interaction.


Reliability of the Eyetone instrument and the Reflectance Meter in instant blood glucose determinations.

The blood glucose of 271 diabetic subjects (140 boys and 131 girls), followed in a diabetes clinic, was determined by three methods: 1) Reflectance Meter (Ames), 2) Eyetone (Ames), and 3) AutoAnalyzer (Technicon). The results were statistically analyzed at four blood glucose concentration ranges (less than 100, 100 to 200, 201 to 300 and greater than 300 mg/dl). The Eyetone instrument and the Reflectance Meter were found to be simple and exact methods for instant glucose determination as compared with the standard AutoAnalyzer technique. The Reflectance Meter was inexact in the blood glucose range of 201 to 300 mg/dl. The Eyetone instrument was reliable within the range of 10 to 400 mg/dl and was found to be useful for quick glucose determination in the clinic or home.


Intravenous glucose tolerance after 18 months on progestogen or combination-type oral contraceptive.

The effect of long-term use of different oral contraceptives compounds was evaluated in two groups of 36 normal women on the basis of blood glucose and plasma insulin changes measured during i.v. glucose tolerance tests. Progestogen (ethynodiol diacetate) alone or a combination-type steroid compound (norethynodrel-mestranol) were used. After 18 months of ethynodiol diacetate therapy, a mild though obvious diabetogenic effect similar to that seen with norethynodrel-mestranol was observed.


Improvement in the anemia of hemodialyzed patients following subtotal parathyroidectomy. Evidence for the role of secondary hyperparathyroidism in the etiology of the anemia of chronic renal failure.

An increase in the blood hemoglobin concentration was found in four of five patients on chronic hemodialysis following subtotal parathyroidectomy performed for the treatment of incapacitating osteodystrophy. In a sixth hemodialyzed patient, there was a striking increase in the hemoglobin level following treatment with 1alpha-hydroxycholecalciferol with suppressed parathyroid overactivity. It is concluded that surgical or "chemical" parathyroidectomy seems to be associated with improvement of the anemia of patients with chronic renal failure.


Hepatic injury due to pyridinol carbamate.

Two cases of severe hepatic parenchymal injury are presented. One case can be attributed to pyridinol carbamate with certainty, and this drug was probably the cause of hepatic injury in the second case. Pyridinol carbamate should be added to the list of drugs which are known to cause parenchymal liver damage.


Tear secretion in patients with nonspecific eye complaints.

Tear secretion, as measured by Schirmer's test, was significantly reduced in 42 (9%) of 466 patients with nonspecific anterior segment complaints. One of these 42 patients were found to have systemic lupus erythematosus and another had benign mucous membrane pemphigoid.


Congenital membranous obstruction of the inferior vena cava.

Congenital membranous obstruction of the inferior vena cava is a rare phenomenon resulting from failure of anastomosis between the right subcardinal vein and the liver. A case is reported in which the presenting symtpom was bleeding from esophageal varices. Cirrhosis was present and other signs of vena caval obstruction were minimal. The diagnosis was made only after an ineffective mesenterico-caval shunt had been performed. Venacavography or pressure measurements in the inferior vena cava are mandatory before attempting a porta-systemic shunt operation.


Genital tract anomalies associated with in utero exposure to diethylstilbestrol.

The gross anatomic changes and the vaginal epithelial changes in 687 women exposed in utero to diethylstibestrol are described, as well as the findings in 66 of these women who agreed to undergo hysterosalpingography. Of 537 women in the study group whose time of in utero exposure to stilbestrol was known. 33% demonstrated gross anatomic changes of the cervix, whereas 44% of them were found on colposcopic examination to have vaginal epithelial changes. These changes occurred in a significantly higher percentage of women exposed in utero before the 20th week of gestation. Among the women included in the study on the basis of a review of their prenatal history, gross anatomic changes of the cervix seemed to be more common in those under the age of 19 years than in those older than 19 when they first entered the study. Gross abnormalities in the uterus were noted in 44 of the 66 women studied by hysterosalpingography. These changes consisted primarily of marked aberrations in the size and shape of the uterine cavity.


Ethnic-related incidence of ovarian carcinoma in New York City.

A two-part statistical study of ovarian cancer in the population of New York City was conducted in an effort to explain the striking racial differences in the incidence of death from this disease. The first part of the study comprised an examination of 487 death certificates from case reports in 1964 and 387 in 1974, with emphasis on race and religion, and revealed that there is 1) a lower incidence of ovarian cancer among nonwhite than white women and 2) a greater mortality from cancer of the ovary among Jewish than non-Jewish women. The second part entailed a review of 143 records from hospitals in New York City from which more precise data, such as history and treatment, were available. The review enabled us to confirm diagnoses and to investigate whether specific clinical features are directly related to racial incidence. No etiologic factors could be correlated with the disease, but further epidemiologic studies are warranted.


[Yersiniosis].

A survey was undertaken about bacteriologic, epidemiologic and clinical features of infections caused by Yersinia. Yersinia enterocolitica and Yersinia pseudotuberculosis are gram negative rods of the enterobacteriaceae family. The number of cases of these infections has increased considerably in the past few years. Erythema nodosum often occurs after an enteritic infection by Yersinia. Other skin manifestations are erythema exsudativum multiforme, erythema figuratum and "drug-eruption-like exanthema". Moreover, Yersinia-arthritis may occur. In one particular case a Reiter-syndrome was described. The mechanism whereby Yersinia induce skin lesions is unknown. Prognosis is good. Therapy of choice for infections caused by Yersinia are tetracyclines.


[Treatment of malignant melanoma with dinitrochlorobenzene ointment].

35 patients with malignant melanomas in different stages were treated with dinitrochlorobenzene according to Malek-Mansour in the last three years. Nine typical cases are demonstrated. The treatment is more effective when the tumor lies close to skin surface and has not yet spread. Distant metastases may react--but normally these metastases cannot be removed. Regarding effects and side effects of DNCB, the methods of treatment and the range of indications are described.


[Treatment of psoriasis vulgaris with tar- and oil-containing seawater baths].

Treatment of psoriasis vulgaris with tar and oil containing seawater baths are reported and compared to sulfur baths. The superiority of the tar-seawater treatment compared to sulfur baths is confirmed. For the first time good experiences with a new oil bath are reported.


[Perioral dermatitis].

The cause of perioral dermatitis remains unclear. It is not due to the application of fluorinated corticosteroids. For therapy Locoid cream and tetracycline are recommended. There are some cases which are not influenced by any therapy. In these cases psychotherapy is sometimes effective.


A simple method for estimating a 'heparin binding capacity' of human serum.

A method for estimating a 'heparin binding capacity' of human serum is described. When human serum is diluted with a low ionic strength, heparin-containing buffer at pH 5.5, protein-heparin electrostatic complexes form in solution with subsequent formation of insoluble aggregates which can be collected by centrifugation. Quantitative determination of the relative amounts by weight of protein and heparin in the insoluble heparin-protein aggregates permits estimation of a combining ratio at which serum proteins bind with heparin to precipitate from solution. This weight combining ratio of protein and heparin is a quantitative measure of the total affinity for heparin of all proteins in serum which bind heparin at pH 5.57 to form an insoluble complex. An unusually high affinity for heparin by an abnormal serum protein or an increase in amount of a normally-occuring, high heparin-affinity, serum protein would alter the average protein: heparin combining ratio and increase the 'heparin-binding capacity' of human serum. The converse would be true for serum proteins having a low affinity for heparin, lowering the 'heparin-binding capacity' of human serum. The described method was used to evaluate the 'heparin-binding capacity' of serum proteins in normal individuals and in persons with cystic fibrosis.


Copper/zinc ratios in whole blood, plasma, and erythrocytes in pulmonary tuberculosis.

Concentrations of copper and zinc in plasma, whole blood, and erythrocytes were determined in pulmonary tuberculosis (TB) patients and controls by atomic absorption spectrophotometry. The plasma and whole blood copper/zinc ratios were markedly higher in the TB patients. Eighty-seven percent of the TB patients had plasma copper/zinc ratios above 2.00, and 94% had whole blood copper/zinc ratios above 0.20. None of the controls had plasma copper/zinc ratios above 2.00, while 24% of the controls had whole blood ratios greater than 0.20. Whole blood and plasma copper/zinc ratios appear to be more sensitive indicators of the presence of pulmonary TB than the individual copper and zinc concentrations. Patients with conditions in which copper and zinc metabolism are altered might benefit from the monitoring of copper/zinc ratios.


A practical method of antimicrobial surveillance.

This antimicrobial surveillance program clearly relates inpatient antimicrobial usage to therapeutic or prophylactic indications. One nurse-epidemiologist gathers data for a medium-sized Veterans Administration hospital, in addition to carrying out infection surveillance and educational responsibilities, and reviews the data weekly with an infectious disease physician. Usage of antimicrobials for surgical prophylaxis is the area where violations of generally accepted criteria for usage can be most readily documented. Only 31% of usages were deemed appropriate. A similar percentage (about 65%) of antimicrobial usages were judged "appropriate" on the medical and surgical services in treatment of wound and urinary tract infection. Treatment of respiratory tract infection and sepsis was judge "appropriate" in over 85% of instances on the medical service. These categories contained too few cases to summarize on the surgical service.


Mutant hemoglobins having elongated chains.

Globin subunits may be elongated because of a base substitution in the termination codon, a crossover out of phase (frame shift) or a crossover in phase. This review presents structural, genetic, biosynthetic and clinical information on the eight variants having elongated chains which have been described to date.


Hb J Camaguey alpha 2 141(HC3) Arg replaced by Gly beta 2: a new abnormal human hemoglobin.

An electrophoretic fast-moving hemoglobin was found in a Cuban family of Spanish descent. Structural studies demonstrated a replacement of arginine by glycine at alpha 141(HC3). This change is not associated with clinical symptoms, although the substitution is in one of the residues involved in the stabilization of the deoxy form of the hemoglobin molecule.


Acylation of hemoglobin by glutarylsalicylamide and its effect on oxygen transport properties.

Hemoglobin A was modified in vitro with 0.02-0.03 M glutarylsalicylamide for two hours at pH 7.2 and 37 degrees C. The extent of modification was about 30-50%, as estimated by visual comparison after electrophoretic separation. A substantial decrease in oxygen affinity of modified hemoglobin solutions was observed. Similar results were also obtained for dilute cell suspensions of washed red blood cells and whole blood after GSM modification. Other properties such as cooperativity, Bohr effect and 2,3-DPG dependence remained essentially unchanged. Athough the site(s) of modification have not been determined, it is unlikely that they would involve any amino acid residue contributing to the above allosteric properties.


Studies of globin chain synthesis and globin mRNA content in a patient homozygous for hemoglobin Lepore.

Globin chain synthesis and globin mRNA content were studied in blood cells of a patient homozygous for Hb Lepore. Peripheral blood cells incubated with tritiated leucine synthesized approximately 1.5 to 3% as many Lepore globin chains as alpha chains. Globin mRNA in peripheral blood cell RNA was assayed by molecular hybridization assays using human alpha and beta cDNA, and the results indicated the presence of approximately 1% to 2% as much beta-like mRNA (presumably deltabeta Lepore mRNA) as alpha mRNA. The amount of Lepore deltabeta chain mRNA in peripheral blood cells is therefore proportional to the amount of Lepore globin chain synthesis in the same cells. An incidental observation was the finding that peripheral blood cell RNA of this patient, at a time when she was being heavily transfused, contained substantially higher levels of beta-like mRNA (relative to alpha mRNA) than in subsequent studies. Cell-free translation of this mRNA however revealed that it contained authentic beta chain mRNA which must have been derived in some way from the transfused blood cells.


Clinical and hematological studies in a family with hemoglobin Vancouver.

Hb Vancouver (alpha2beta2 73 (E17) ASP yieldTYR) was found in combination with betaomicron thalassemia trait in a Chinese male who presented with splenomegaly and thalassemia intermedia (3). The family study has revealed two members with beta thalassemia trait, one heterozygote for Hb E, and two heterozygotes for Hb Vancouver. The Hb Vancouver heterozygotes were clinically normal but their erythrocytes showed reduced osmotic fragility and occasional target cells.


Location of amino acid residues in human deoxy hemoglobin.

A table has been compiled of the spatial disposition of the amino acid residues in the human deoxy hemoglobin tetramer. The table also indicates regions of possible contact between residues in each subunit and possible contacts between subunits.


Histochemical and electron probe analysis of secretory ameloblasts of developing rat molar teeth.

Calcium was not found in secretory ameloblasts and stratum intermedium cells when treated with OsO4-pyroantimonate or when surfaces prepared by fracturing fresh, rapidly frozen, developing molar tooth germs were subject to electron probe X-ray analysis. Pyroantimonate reaction product, considered to be calcium, was found in mitochondria of enamel organ cells which were first placed in a bath containing calcium and potassium. The plasma membrane was disrupted in cells ehich showed mitochondrial localization of reaction product. The results provide no data which indicates that enamel organ cells have a direct, active role in the movement of calcium into the enamel. Rather, it is suggested that the secretory enamel organ might serve as a selective barrier in regulating the initial mineralization of enamel.


Electron probe analysis of maturation ameloblasts of the rat incisor and calf molar.

Rapidly frozen upper incisor teeth of rats and molar teeth of calves were freeze fractured, freeze dried and dry dissected in preparation for energy dispersive x-ray emission microanalysis in the scanning electron microscope. Successive zones of ameloblasts adjacent to maturing rat incisor enamel were examined, beginning with cells adjacent to the least mature enamel and progressing to cells over increasingly more mature enamel. Pronounced Kalpha1,2 x-ray peaks were obtained for P, S, Cl, K and Fe but not for Ca. Ca levels were also very low compared with P, S, Cl and K in calf molar maturation ameloblasts, whereas they were high in the distal poles of the secretory odontoblasts in the same specimens. The findings indicate that both intra- and extracellular Ca levels are extremely low in maturation ameloblasts. It is concluded that Ca is neither stored nor concentrated in large amounts by the maturation ameloblasts prior to its entry into the enamel. The suggestion is made that the maturation ameloblasts might regulate entry of calcium into enamel by serving as a selective barrier.


Age-dependent increase in the non-specific cholinesterase activity of the capillaries in the rat neostriatum.

Histochemically demonstrable non-specific cholinesterase activity in the capillaries of the neostriatum of 3-5-month-old rats was much weaker than that of 24-27-month-old rats. In the young adult rats the activity was electron microscopically localized mainly in endoplasmic reticulum and perinuclear cisternae of the endothelial cells, while capillaries of old rats showed a positive reaction also in the basal lamina and outer cell membranes of glial processes.


The multiple forms of brain acetylcholinesterase. II. A suggestion of their functional importance.

The pattern of the multiple forms of the acetylocholinesterase (AChE, E.C. 3.1.1.7) of the rat brain is investigated using polyacrylamide gradient micro-gel electrophoresis with regard to a possible functional importance of this individual forms. The patterns of the AChE-forms of selected regions of the CNS are compared and certain differences could be shown. After increased cholinergic input (into the hippocampus by electrical stimulation of the nc. septi medialis) an aggregation of AChE subunits is detectable. Subletal intoxication with an irreversible inhibitor of AChE is followed by a faster recovery of the smaller forms. A suggestion of a possible functional role of the multiple forms of AChE is discussed.


[Innervation of the anterior byssus retractor muscle (ABRM) in Mytilus edulis L. and in Mytilus galloprovincialis Lmk. V. Cytochemical localization of cholinesterase activities (author's transl)].

Specific and non specific cholinesterase activities were demonstrated in the ABRM of Mytilus edulis L. and Mytilus galloprovincialis L. by means of different techniques. The results were found identical for both species: neuromuscular junctions "en grappe"-type scarely distributed within the ABRM, contain AChE. According to the histochemical inhibition tests, (a) the eserine inhibits AChE activity of the ABRM with a level of 5-10(-5) M or higher, (b) the ChE non specific activities are inhibited by iso-OMPA level between 5.10(-5) to 10(-4) M. The histo- and cytochemical observations were completed by showing the existence of neuromuscular junctions containing small clear vesicles: they probably are the morphological support for ACh presence. Moreover, specific and non specific ChE activities were localized in the glio-interstitial cells. AChE precipitates were developed along the ABRM sarcolemma, some muscle mitochondria and in the intercellular spaces remain enigmatic.


Cytochemical investigations on the localization of 5'-nucleotidase in the rat hippocampus with special reference to synaptic regions.

The fine structural localization of the 5'-nucleotidase was investigated in the CA3 region of the rat hippocampus. The attention was focussed on the occurrence of the enzyme in the synaptic region. The 5'-nucleotidase activity was demonstrated at the surface membranes of axons and dendrites. Prominent portions of enzyme activity were detectable in the nuclei and the nuclear envelope, whereas the cytoplasmic organelles were nearly devoid of reaction product. In synapses five types of 5'-nucleotidase localization were revealed. A participation of the enzyme in the process of neurotransmission is discussed.


Histochemical demonstration of type IV collagen in the renal glomerulus.

Disulfide-groups are demonstrated in the basement membranes of glomerular capillaries, proximal convoluted tubules, and collecting ducts by means of a thiosulfathion/Alcian Blue +0.8 Mol MgCl2-staining sequence. It is suggested that the reaction shows type IV collagen of basal lamina material, which is characterized by a relatively high cystine content (8 half-cystine residues/1000).


[Electrical stimulation of hearing in humans: a survey of the actual state of development of an implantable prosthesis for sensorineural deafness (author's transl)].

Recent clinical results show that electrical excitation of hearing sensations with implanted electrodes in the inner ear can be successful in suitable deaf persons. A critical literature review shows that some results have been described too vaguely and that there still exist numerous methodical and technical deficiencies. Even with multichannel stimulation, true tonotopical hearing could not be achieved. Periodicity hearing alone is not sufficient for the discrimination of one-syllable words. However, most deaf persons fitted with surgically implanted electrodes judged the new hearing sensations as being agreeable and quite useful. There seem to be no long term harmful effects of these implants upon the state of the acoustic nerve. However there are still a series of basic questions in auditory physiology pending which can only be solved through intensive collaboration of the clinical disciplines involved.


[A surgical approach for the cochlear implant (author's transl)].

Although the round window is most commonly employed for insertion of a cochlear electrode, manipulation through this route can be difficult. The author gives data for orientation to a new approach for placing a cochlear implant. In this manner, the nerve fibers of the N. cochlearis in the entire cochlear region can be reached and stimulated.


[Vasoactive drugs and oxygen content in the perilymph (author's transl)].

The effect of different vasodilating drugs on the perilymphatic oxygen content in the cat has been examined by means of the polarographic method. The drugs used such as Papaverin, Rheomacrodex, Ronicol, Praxilen and Lasix have had no significant effect on the oxygen concentration in the perilymph. Histamin, 7% Na2CO3 and 50% glycerol have produced a diminution of the perilymphatic oxygen tension. Only angiotensin has produced a 20% rise of the oxygen pressure in the perilymph. This effect is, however, five times smaller than that reached by inhalation of 5% CO2 and 95% O2.


[Thyroid diseases. Impulses for the ORL-physician].

Diseases of the thyroid gland are not uncommon. Understanding the basics of physiology, pathophysiology, endocrinology and nuclear medicine, the otolaryngologist very often will uncover pathologic findings which he previously might have overlooked. A systematic evaluation of thyroid disorders will result in a worthwhile and fascinating collaboration among specialists in internal and nuclear medicine as well as specialists in surgery.


[Studies on the genetics of otosclerosis (author's transl)].

101 families with confirmed otosclerosis were investigated, and after correction for age an incidence was found of otosclerosis of 29.5% amongst the parents, 17.9% amongst the siblings and 8.8% amongst offspring. The statistical data for otosclerosis published to date were treated similarly giving together with our own as large a collection as possible. From this the risk of repeat occurrence of otosclerosis could be calculated to 10% in the brothers and 20% in the sisters of otosclerotic patients. The risk rates of occurrence for their children are the same. These data are intended for use in the genetic counseling of this disorder.


[Electron microscopic studies of Reinke oedema (author's transl)].

With the electron microscope, changes in the epithelium and subepithelial tissue in Reinke's oedema are more clear. An intense widening of the intercellular spaces is observed, with the presence of a strongly electron dense substance. In some cells, especially in the cells of the stratum spinosum and in the endothelial cells of the capillary vessels, intracytoplasmic cystic formations are observed, which in some cases are located in nuclear invaginations. However, these cystic formations can give a false impression that they are intranuclear if an incorrect tissue section is made.


[Obstructive emphysema--a typical late event after reconstructive surgery for laryngeal or tracheal stenoses (author's transl)].

Obstructive emphysema following reconstructive surgery for laryngeal and tracheal stenoses is a frequent occurrence which may well be a typical event. Four stages occur which can be differentiated according to their severity. These are specified and illustrated by the pathophysiological values of pulmonary function tests in 29 patients. A significant correlation exists between the degree of obstructive emphysema or physical irregularity of the airflow which occurs and the interval of time since operative reconstruction of the airway has taken place.


[Possibilities of error in studies of neck torsion nystagmus (author's transl)].

The demonstration of neck torsion nystagmus confirms the diagnosis of cervical spine syndrome. To demonstrate this finding, it is necessary to observe the following points: Precise performance of the examination technique; ENG with absolute isolation of the patient; examination with an easily movable rotating chair; prevention of turning of the patient's head in the direction of the chair's movement. Spontaneous nystagmus, movement of the eyelids, optokinetic nystagmus, and electrical artefacts all interfere with detection of neck torsion nystagmus, and are sources of error in its study.


Influence of hypoxia on the longitudinal distribution of pulmonary vascular resistance.

We have examined the influence of hypoxia on the longitudinal distribution of vascular resistance and intravascular pressure in isolated cat lungs using the low-viscosity bolus technique. Hypoxia increased total vascular resistance, decreased total lung blood volume, and moved the maximum local resistance downstream away from the main pulmonary artery. The circumference of the main pulmonary artery was increased and the extravascular lung water (double indicator dilution technique) was decreased by hypoxia. Thus, it would appear that distension of the large pulmonary arteries and a decrease in the amount of lung tissue perfused contributed to the change in resistance distribution brought about by hypoxia.


Simultaneous helium and nitrogen single-breath washout: lung model simulation.

By use of a model, simultaneous bolus and resident N2-washout curves are simulated to examine the effects of inhomogeneous lung elasticity and unequal critical airway closing pressure. Pathological conditions are divided into A, B, and C, where dominant lesions involve the upper, entire vertical, and lower regions, respectively. In elastic inhomogeneity, the He plateau (phase III) is upward, flat, or downward in conditions A, B, and C, respectively, depending on the vertical location of the lesion. Conversely, the N2 plateau is upward in three conditions, reflecting overall interregional and intraregional inhomogeneity. The terminal He rise (phase IV) has a clear relationship to the airway closure than the terminal N2 rise. The present study supports the previous prediction that the simultaneous bolus and N2-washout study provides additional information. This analysis will improve the means for assessing mechanical disorders in diseased lungs.


Evolution of intrathoracic airway mechanics during lung growth.

Elastic recoil pressure of the lungs (Pst(L)), maximum expiratory flow rates (MEF), critical transmural pressure of the collapsible flow-limiting segment (Ptm'), and S-segment conductance (Gs) have been determined in 40 healthy subjects, 7-18 yr old. Pst(L), measured at different lung volumes (fractional) from the expiratory quasi-static pressure-volume curves, increases progressively with age. MEF's, at different lung volumes, are closely related to total lung capacity (TLC); the ratios MEF/TLC, at all lung volumes, are independent of age. Ptm' is also independence of age and body height, most values lying between 0 and -15 cmH2O; this finding suggests that the locus and the behavior of the collapsible segment do not change during growth. Gs, in absolute value, increases with growth but, when adjusted for lung size, Gs decreases steadily with age and body height. These relations suggest that, from childhood to adolescence, the air spaces grow disproportionately more than the airway system.


Continuous measurement of gas partial pressures in intracerebral tissue.

A mass spectrograph technique has been developed for measurement of physiological gas partial pressures locally in the brain. The sampling cannula is implanted stereotaxically and remains in situ for several weeks. It is a thin cylinder in shape, and is covered with a thin polyethylene membrane across which gas molecules can be sampled continuously. The conductance of this membrane is well adapted to the limited rate of replacement of gas molecules afforded by the cerebral tissue, hence there is no depletion around the cannula; this depletion has until now been the major problem of this technology. The present technique provides a continuous measurement with fast response time, which is directly proportional to the partial pressures of the gases. The variations can be expressed as a percentage of the base-line value.


Maximal frequency of breathing at various tidal volumes in airways obstruction.

To determine the relative importance of control system and of mechanical and metabolic properties of the motor system on the maximal frequency of breathing (1/t) at various tidal volumes (VT), we have studied the relationship between cycle period (t) and tidal volume in 10 normal subjects, in 9 patients with chronic obstructive lung disease, and in a normal subject breathing against different resistive loads. The results, expressed according to the equation t = t0 + b VT (where t0 represents the time required for a breathing cycle at zero VT and b means the additional time required for a breathing cycle with a VT equal to vital capacity), indicate that t0 is independent from the load either in unloaded or loaded normal subjects or in obstructive patients. In fact, although b was found significantly different, t0 remained essentially constant. These findings suggest that the level of maximal voluntary ventilation may be mainly related to metabolic and mechanical properties of the motor system (muscles of breathing and load imposed on them).


Effects of severe prior exercise on assessment of maximal oxygen uptake.

Five moderately fit males (50.8 ml.kg-1.min-1) performed 14 continuous type VO2 max tests on a motor-driven treadmill. Randomly assigned experimental sessions, consisting of three tests each and separated by 10 (tests 1, 2, 3), 20 (tests 4, 5, 6), 30 (tests 7, 8, 9), or 40 (tests 10, 11, 12) min, were conducted at a consistent hour for each subject every 4th day. Two separately performed tests were also included in the random assignment with the test eliciting the highest VO2 max value designated as the standard reference (SR). VO2 max values for tests 1 through 12 were not significantly different from the SR in spite of elevated pretest blood lactate concentrations ranging from 5 mM to 16 mM. Performance time was reduced for all tests other than tests 1, 4, 7, and 10, reaching the level of statistical significance (P less than 0.05) in tests 2, 3, 5, 6, and 9. It was concluded that valid and reliable assessment of VO2 max is possible even though testing is initiated with subjects in varying stages of exhaustion.


Efficiency of anaerobic work.

This study was undertaken to compare the efficiency of aerobic and anaerobic work. Nine subjects worked at approximately 100% VO2 max for 2 min while inspiring gas mixtures with O2 fractions ranging from 0.13 to 0.21. Exercise O2 uptake, recovery O2 uptake, and blood lactate concentration were measured. Steady level O2 uptake was measured in normoxia at submaximal loads of about 30, 50, and 70% of VO2 max. Fast recovery O2 uptake did not change as PIO2 was varied. Exercise O2 uptake and blood lactate concentrations were linearly related to PIO2. The ratio of the slopes of these lines provided an empirical expression of the O2 equivalent of blood lactate. This ratio was constant, suggesting that it is not less efficient to use ATP synthesized anaerobically. Energy input from lactate was calculated using this factor. Efficiency decreased as power output increased even at the submaximal work rates. This may result from either 1) a decrease in muscle efficiency, 2) an increase in metabolism that is not directly related to the external work, or 3) some combination of 1 and 2.


Quantitative changes in permeability of rat lung epithelium in lung edema.

The pulmonary absorption of 14C-labeled urea, mannitol, inulin, and dextran was measured in vivo in anesthetized rats with alpha-naphthylthiourea (ANTU)-induced (5 mg/kg, ip) lung edema. At 1 h after ANTU treatment, the absorption of mannitol was significantly increased; in 4-h ANTU-treated animals, the absorption of urea was unchanged, whereas the absorption of mannitol, inulin and dextran was increased markedly compared to controls. Although disappearance of each solute from control lungs could be described by a single, first-order rate, absorption time curves for mannitol and inulin showed at least two components in edematous lungs: a fast component(s) and a slower, first-order component; fast-component rates for the two saccharides appeared to be similar; the slow-component rate for each compound was not significantly different from its control rate. The results suggest that fast-component absorption in ANTU-treated rats represents a fraction of instilled solute which entered damaged areas of lung where the porosity of the absorbing membranes was markedly increased, whereas slow-component absorption occurred from normal areas of lung.


Acute dehydration: body water distribution in acclimated and nonacclimated Psammomys obesus.

Body water distribution after "acute dehydration" treatment (37 degrees C) was studied in Psammonys obesus before and after acclimation at 34 +/- 1 degrees C for 16-18 days. Determinations of water compartment volumes were performed on anaesthetized (thiopental sodium) nephrectomized animals. Plasma volume (PV) and extracellular volume (ECV) were measured by T-1824 and [14C]inulin, respectively. Total body water was determined after desiccating the animals. Albumin outflux was calculated from the half-life (T1/2) of T-1824 and total plasma albumin mass. Nonacclimated animals conserved PV as long as dehydration did not exceed 10-11% loss of body wt. This conservation was at the expense of ECV and was associated with diminished albumin outflux (T1/2 T-1824 approached infinity). With increased dehydration PV retention failed and a resumption of albumin outflux occurred. Acclimation resulted in diminished albumin outflux in both control and dehydrated animals (T1/2 T-1824 approached infinity). Most of the water lost during dehydration was of intracellular origin. It was concluded that reduction in permeability of the capillary bed during dehydration and acclimatization plays an important role in PV and ECV regulation.


Effect of curare on maximum static PV relationships of the respiratory system.

The effect of respiratory muscle weakness on the maximum static pressure-volume (PV) characteristics of the respiratory system was studied in four healthy males infused slowly with d-tubocurarine (dtc). Inspiratory capacity (IC), expiratory reserve volume (ERV), maximum static inspiratory and expiratory mouth pressures at four lung volumes, and handgrip were measured during induction of, and recovery from muscle weakness. The maximum effect of dtc varied among the muscle groups tested; peripheral muscles were most severely affected, expiratory muscles moderately, and inspiratory muscles least affected. At each level of weakness studied, decreases of IC and ERV were proportional to decreases of maximum static mouth pressures. Vital capacity, measured at each level of weakness was much less than values predicted from the static mechanical properties of the respiratory system. Our findings suggest that the marked change in the extremes of lung volume during submaximal neuromuscular blockade (SMNB) is due, in part, to unequal distribution of muscle weakness, reflected by decreased ability to change ribcage dimensions even at modest levels of SMNB.


Effect of five human anesthetics on respiratory control in cats.

The effect of halothane, fentanyl, Innovar, thiopental, and ketamine on inspiratory output, vagal influence, and chest wall reflex was assessed in seven cats lightly anesthetized with pentobarbital, using the method of airway occlusion with and without rapid vagal cooling. All anesthetics depressed inspiratory output, as expressed by deltaP/deltat, of the first occluded inspiration. However, only halothane depressed peak inspiratory output (Pmax). Phasic vagal influence was markedly depressed by 2% halothane but was preserved under other anesthetics. The ability to induce tonic vagal influence (expiratory muscle recruitment) was lost under halothane. Inspiratory inhibitory chest wall reflex was evident in two cats during airway occlusion. Addition of any test anesthetic abolished the reflex. It is concluded that halothane should be avoided in studies dealing with assessment of vagal influence.


A microampere radiotelemetry transmitter for measurement of temperature from unrestrained subjects.

A miniature radiotelemetry transmitter is described suitable for chronic or acute monitoring of temperatures from animal or human subjects. The transmitters can be easily constructed with little or no electronics background from discrete components readily available from any electronics supplier. Transmitters weighed from 2.5-20 g, had volumes of 0.8-3.5 ml, had normal currents of 50-120 muA with potential transmitter lives of 35 h to greater than 1 yr, and transmission ranges of 10-30 m. Transmitters could be implanted, swallowed, or connected to chronically or acutely attached temperature probes. The design of the telemetry system allows for reception on any commercial FM receiver. Depending on mode of decoding the temperature data transmitter signal can be accurate to measure changes of from 0.15 to 0.015 degrees C. Thus with a minimum of expense and little electronics background a temperature-dependent transmitter system can be constructed for monitoring temperatures from unrestrained subjects.


Computerized measurement of pulmonary conductance and elastic recoil.

A system devloped for on-line measurement of transpulmonary pressure, gas flow at the mouth, change in expired volume and plethysmograph volume uses a minicomputer to control a multiplexed analog to digital converter. The computer identified samples as static or dynamic values by monitoring a voltage activating a solenoid valve, used to close the airway. Analysis of these samples by other task-specific programs yielded the static deflation pressure-volume (PV) curve, the conductance-recoil pressure, GL-Pst(L), relationship and the maximum expiratory flow-volume (MEFV) curve; the MEF-Pst(L) curve and conductance upstream from the equal pressure point were derived. The PV relationship was represented by a fourth-order polynomial and the GL-Pst(L) relationship by linear regression. In 11 subjects the results obtained using on-line data collection, compared with manual analysis of oscillograph recordings, showed small differences in static compliance and in the maximum Pst(L); but overall the two methods showed excellent agreement. Besides advantages of speed and objectivity, this system facilitates a more rigorous analytical treatment of elastic recoil and conductance.


Respiratory flow integrator with improved stability.

A circuit was designed for integrating respiratory flow signals over time to produce volume signals. The circuit involves a simple integrator and three compensation subcircuits which control integrator drift caused by ambient temperature changes, flow signal base-line errors, and random signal errors. A functional unit built according to the circuit design requires initial adjustment, but no further adjustment before or during sustained use. Integration errors are typically less than 1%. The only flow signal requirements are that they be bidirectional and within the human physiological frequency range.


Computer-aided measurement of breath volume and time components using magnetometers.

A computer-assisted method is developed for analyzing volume and time components of individual breaths using a previously developed magnetometer method for recording anteroposterior (AP) diameters of rib cage and abdomen. Calibration constants for the magnetometer system are computed during simultaneous measurements of airflow at the mouth for several breaths during spontaneous breathing. Tidal volume and inspiratory and expiratory times can then be computed from the magnetometer signals alone, without imposing respiratory devices at the subject's airway. No respiratory isovolume maneuvers are necessary. Results from normal subjects and from one patient with bilateral diaphragmatic paralysis show that the magnetometer analysis is closely comparable to standard measurements made from airflow recordings. The magnetometer technique thus provides an accurate means of measuring volume and time components of breathing in man, avoiding the behavioral or reflex effects induced by mouthpiece, nose clip, or face mask. Because no special respiratory maneuvers are required for calibration, the technique will be well suited to the study of breathing in those who are ill.


Cardiac dysrhythmias associated with gastric dilatation-volvulus in the dog.

Of 16 dogs treated medically and surgically for gastric dilatation-volvulus, 11 developed electrocardiographic evidence of ventricular dysrhythmias. Seven of these dogs had ventricular dysrhythmias for the first time during their hospitalization after surgery. The ventricular dysrhythmias included ventricular premature depolarizations, slow ventricular rhythms, paroxysmal ventricular tachycardia, ventricular tachycardia, and multifocal ventricular tachycardia. Two of these dogs had electrocardiographic evidence of atrial premature depolarizations at the time of hospitalization. Treatment with lidocaine hydrochloride or procainamide hydrochloride was successful in reestablishing sinus rhythm in 9 of the 11 dogs with ventricular dysrhythmias.


Pulmonary edema in a dog with acute pancreatitis and cardiac disease.

Acute pancreatitis and cardiac disease were diagnosed in a dog with pulmonary edema. The early clinical course and initial thoracic radiographs suggested that the pulmonary edema was noncardiogenic. The late clinical course was complicated by heart failure. The dog died, and a necropsy was performed. Histologically, an acute, severe capillary-alveolar membrane lesion was found in the lungs. Review of the human medical literature indicated that respiratory complications, including pulmonary edema, are commonly recognized in people with acute pancreatitis. Furthermore, in acute pancreatitis of human beings, the existence of specific mechanisms of pulmonary injury is suspected. Retrospective consideration of this case suggested that the initial pulmonary edema was induced by acute pancreatitis.


Prophylactic and therapeutic use of tetracycline during an epizootic of ehrlichiosis among military dogs.

An epizootic of canine ehrlichiosis at the Military Working Dog Center, Pakchong, Thailand, was arrested by prophylactic and therapeutic use of tetracycline and by control of ticks. Oral treatment with tetracycline (66 mg/kg of body weight daily for 14 days) effected remission of signs of disease in 60 of 62 clinically affected dogs and resulted in disappearance of serum antibody in 119 (60%) of 198 seropositive dogs treated during the 2-year study period. Transmission of Ehrlichia canis was interrupted by control of ticks and by daily oral administration of tetracycline at a dosage of 6.6 mg/kg of body weight. When the control program was initiated, 100 (57%) of 174 dogs were seropositive, with one-third of these manifesting clinical signs of ehrlichiosis. The proportion of seropositive reactions progressively decreased to 11% after control was established, and the impact of the disease on health and performance of the dogs was greatly reduced. Eight dogs died before institution of control. Two additional dogs died within the first 2 months after control was established. There was no mortality thereafter.


A new storage medium for canine blood.

A solution consisting of ascorbate phosphate, citric acid, sodium citrate, sodium phosphate, and dextrose was developed to extend the shelf life of canine blood stored for transfusion. The 24-hour poststorage viability remained above 70% for 6 weeks of storage at 4 C. The concentration of 2,3 diphosphoglycerate remained constant for 3 weeks, then declined slowly. After 6 weeks of storage, the 2,3 diphosphoglycerate content was still sufficiently high to allow adequate dissociation of oxygen from oxyhemoglobin in vivo. It was concluded that blood stored up to 6 weeks in this solution would be safe to use for transfusion.


Disseminated aspergillosis in a dog.

A dog with disseminated Aspergillus terreus infection died after a protracted course of hospitalization. Treatment with amphotericin B methyl ester was without effect. The causative organism was found in bone, myocardium, spleen, kidneys, liver, thymus, lymph nodes, and both eyes. Treatment with antimicrobials and corticosteroids prior to hospitalization may have contributed to dissemination of the fungus.


Canine vaginal and uterine bacterial flora.

Vaginal swab specimens were obtained from 41 prepuberal and 81 postpuberal bitches. Uterine swab specimens were obtained from 22 bitches at ovariohysterectomy and from 4 bitches during cesarean section. The specimens were cultured for aerobic bacteria. Most bitches harbored some type of bacteria in the vagina, but coagulase-positive staphylococci were isolated more frequently from prepuberal bitches than from postpuberal bitches. Postpuberal bitches were placed in various groups, based on the stage of the estrous cycle at the time specimens were obtained. Differences in bacterial types isolated from the postpuberal groups were not statistically significant. Uterine culture results suggested that bitches do not normally harbor aerobic bacteria in the uterus.


Retinal degeneration associated with the feeding of dog foods to cats.

Retinal degeneration was observed in cats fed commerical dog food. The retinal degenerative lesions ranged in size from small areas of focal atrophy centered in the area centralis to generalized retinal atrophy. Blindness developed only in cats with generalized retinal atrophy. Analysis of the dog food diets, both dry and canned, revealed that taurine was absent or was present in very low concentrations when compared with control cat food diets. Plasma amino acid analysis also revealed taurine deficiency.


Effect of age and sex on the prevalence of intestinal parasitism in cats.

The effects of age, sex, and neutering on the prevalence of feline intestinal parasitism were evaluated by fecal examination of 1,294 cats admitted to the University of Missouri Veterinary Teaching Hospital for the 3-year period, 1974 to 1976. Approximately 37% of the cats examined had 1 or more parasite species. Ascarids were the most commonly encountered parasites (24.4%), with coccidia (6.7%), hookworms (6.4%), tapeworms (5.2%), and trichurids (2.6%) being less frequently observed. Most parasitisms were monospecific. Considering age categories from birth to 5 years, patent ascarid infections were less prevalent in cats greater than 6 months old, whereas hookworm infections were most prevalent in cats 1 to 5 years old; trichurids (whipworms and capillarids) were most often found in cats greater than 6 months old; and coccidia were found with uniform frequency in cats of all age categories. Sex seemed to have no effect on prevalence of parasitism, and the only effect of neutering was on the occurrence of ascarid infection, with spayed females having a prevalance of 14.3%, castrated males, 17.8%, and their intact counterparts, 26%.


Characterization and treatment of acid-base and renal defects due to urethral obstruction in cats.

In 23 cats, urinary obstruction of 24 to 48 hours' duration caused marked azotemia, hyperphosphatemia, hyperkalemia, and metabolic acidosis. The metabolic acidosis was a consistent finding and was severe in all cats (venous pH, 7.11 +/- 0.09). Serum sodium and chloride were normal. Glycosuria was found in 17 (74%) of the cats. There was no clear difference in blood pH, serum chemical values, or electrolyte concentrations between cats obstructed 24 hours and those obstructed 48 hours or longer. At a mean of 8.4 hours after relief of obstruction, acid-base status was corrected to normal, using fluid replacement and sodium bicarbonate therapy. Blood urea nitrogen serum creatinine, and serum inorganic phosphorus improved significantly (P less than 0.01) at a mean of 19.5 hours after treatment. Variation in azotemia after fluid replacement suggested variable decreases in glomerular filtration rate after relief of obstruction. Hypokalemia occasionally developed after relief of obstruction during the postobstructive diuresis. It was concluded that fluid and electrolyte therapy must be regulated in response to the postobstructive diuresis, to ensure proper medical management.


Urethral prosthesis for treatment of prostatic abscess in a dog.

A dog with a prostatic abscess was treated successfully with surgical implantation of a urethral prosthesis after 6 recurring episodes of abscess formation failed to respond to antibiotic therapy, surgical drainage, and bilateral marsupialization.


Type C botulism in American Foxhounds.

Diffuse lower motor neuron dysfunction developed in a group of American Foxhounds while they were hunting. Of 19 dogs, 10 became weak and 9 became quadriplegic. Three of the quadriplegic dogs died before treatment could be instituted. The remaining quadriplegic dogs recovered after being given supportive treatment, with (4 dogs) or without (2 dogs) trivalent (types A, B, E) botulinal antitoxin. The 10 dogs that were weak recovered without treatment. A markedly decreased amplitude of evoked potentials and increased chronaxy were found by electromyographic examination of 2 of the quadriplegic dogs. A toxic substance that was neutralized by type C botulinal antitoxin in mouse inoculation tests was in the serum and feces of the most severly affected dog presented alive and in a fecal extract of another affected dog. In the one dog necropsied, neither gross nor histologic lesions were found in the central or peripheral nervous systems or in the skeletal musculature. The history, clinical signs, electromyographic findings, toxin neutralization tests in mice, and absence of histologic abnormalities in the neuromuscular system provided evidence for the diagnosis of C botulism.


Regression of hypertrophic osteopathy following pneumonectomy in a dog.

Hypertrophic osteopathy was diagnosed clinically and radiographically in a 6-year-old English Bulldog. Pneumonectomy to remove a primary pulmonary fibrosarcoma resulted in rapid regression of clinical signs and soft tissue enlargement of the limbs and gradual but incomplete regression of periosteal new bone formation over a 15-month postoperative course.


Protocol for diagnosis of seizure disorders in companion animals.

An algorism for diagnosis of the problem of seizures was used to develop a diagnostic plan. The plan was structured in stages for: (1) primary evaluation in the general practice and (2) specialized evaluation in difficult cases.


Tricuspid atresia in a foal.

An Arabian crossbred foal was examined because of a suspected congenital cardiac anomaly. There was a grade V/V crescendo-decresendo holosystolic murmur and thrill in the left 4th intercostal space. The foal was slightly cyanotic and polycythemic. Electrocardiography suggested left ventricular hypertrophy. Angiography and cardiac and vascular pressure recordings led to a diagnosis of pulmonic stenosis. The foal died after cardiac bypass and corrective surgery. Postmortem examination revealed an enlarged right atrium, atresia of the tricuspid orifice, a large, fenestrated patent foramen ovale, eccentric left ventricular hypertrophy, and a large interventricular septal defect. The right ventricle had a small lumen and a relatively thick wall. There was valvular and supravalvular pulmonic stenosis, with poststenotic dilatation of the pulmonary artery. A single coronary artery originated from the anterior sinus of the aorta.


Development of the indusium griseum. II. A semithin light microscopic and electron microscopic study.

Neurogenesis and gliogenesis in the indusium griseum were studied in semithin sections and with the electron microscope. Immature neurons were present at birth, but differentiated rapidly until, by 15 days, they appeared to be fully differentiated. At birth 38% of glia were glioblasts, 47% were immature astrocytes and 15% were mature microglia. Astrocyte differentiation appeared to occur earlier than in adjacent white matter. In the adult, 57% of glia were astrocytes, 21% were oligodendrocytes, and 22% were microglia. The volume density of neuronal nuclei did not change with age, but the volume density of neuronal perikaryon decreased from 34% at birth to 13% at 15 days, while the neuropil increased from 24% to 58%. Very few immature synapses were present at birth, but by 5 days a number of axodendritic synapses were present, and these increased with age.


Growth of striated muscle fibres in the M. lateralis of the European eel Anguilla anguilla (L.) (Pisces, Teleostei).

Diameters of red and white muscle fibres were measured in the M. lateralis of eels cultured under laboratory circumstances over a period of 2 years, starting from the glass eel stage. The red fibres of eels less than 10 cm are unique in that their growth involves increase in diameter only. Growth of the red fibres in eels greater than 10 cm, and of the white fibres in eels at all lengths considered, is characterized by an increase in number as well as diameter, the relative importance of these two methods of growth being related to factors other than the length of the animal. Satellite cells may play an important part in the addition of new, small muscle fibres.


A histological study of post mortem changes in the skeletal muscle of the fowl (Gallus domesticus). I. The muscle fibres.

The changes in the histology of skeletal muscle post mortem have been studied with the light and electron microscopes in the pectoralis thoracica and iliotibialis muscles of the fowl (Gallus domesticus). The carcasses were stored at 40 degrees C and samples removed at various times post mortem. Kinking, contractures, transverse splitting and disintegration were seen in muscle fibres from post mortem muscle. The variation in time and frequency of occurrence of these was wide but no consistent difference between the pectoralis and iliotibialis muscles was found. An attempt was made to integrate the results from the light and electron microscopes to gain insight into the nature of the modifications occurring in the histology of post mortem muscle fibres.


A cytochemical study of the blood of the rainbow lizard (Agama agama).

Smears of peripheral blood from the common rainbow lizard (Agama agama) were examined for the distribution and localization of lipid, glycogen, acid phosphatase, alkaline phosphatase and peroxidase, using a variety of staining techniques. While erythrocytes were strongly reactive with the peroxidase test, granulocytes and monocytes were only weakly or moderately active. Lipid and glycogen, as well as acid and alkaline phosphatase, were found in granulocytes and monocytes. Some lymphocytes showed weak acid phosphatase and moderate PAS activities. A small population of 'mononuclear' cells was noted which were not reactive to any of the histochemical tests adopted.


Electron microscope observations on the ovarian follicle of the domestic fowl during the rapid growth phase.

A survey has been made of the ultrastructural features of the oocyte surface and its enveloping layers, comprising the theca, the granulosa and the perivitelline layer, during the final growth phase of 'yellow yolk' deposition. The following observations suggest that many macromolecular components of the blood plasma have free access from the vasculature to the oolemma: the fenestrated structure of the endothelium of the thecal capillaries, the intercellular spaces containing several erythrocytes in the theca interna, the 20-30 nm particles in the granulosa basal lamina, the wide spaces between the granulosa cells, and the open meshwork of fibres in the perivitelline layer. Numerous coated pits and vesicles, of 0.25-0.35 micron diameter, in the highly convoluted surface layer of the oocyte provide a mechanism for the incorporation of yolk precursors by pinocytosis. Such large coated vesicles and wide spaces between the granulosa cells are lacking in follicles in the preceding growth phase, which is concerned with the deposition of 'white yolk'. Considerable metabolic activity of the granulosa cells is indicated by their prominent Golgi elements, diverse granules, vesicles and villus processes. Cell junctions at the tips of the macrovilli anchor the granulosa to the oocyte. The theca externa, which provides mechanical support for the oocyte and its vascular and nervous elements, consists of sheets of collagen fibrils and fibroblast-like cells. Microfilaments in these cells may contribute to the contractility of the theca. Groups of interstitial cells associated with nerve fibres are present in the theca interna.


Morphometric and histological analysis of the lungs of Syrian golden hamsters.

Hamster lung morphometry and histology have been studied in an attempt to determine differences between hamster and human lungs which may have relevance for lung carcinogenesis studies. Morphometric measurements were made on fresh lungs, lung casts, and histological sections. Cell type and frequency measurements were determined from frozen, paraffin, 1 micron plastic (glycol methacrylate) and electron microscopic sections. A standard terminology for hamster lung histology is established, and differences between hamster and human lung morphometry and histology are discussed.


Palatal shelf elevation in the Wistar rat fetus.

Palatogenesis in the Wistar rat fetus was studied macroscopically, microscopically, ultrastructurally and experimentally between days 13 and 19. The developmental ages of the fetuses were calculated from the smear age of the litter adjusted for individual variations in crown-rump lengths. Palatal shelf elevation occurs at day 16.4 +/- 0.1. Experimentally induced shelf elevation in freshly delivered fetuses was sluggish at day 14, but by day 16.3 it occurred in less than 1 second. Both shelf elevation and shelf fusion begin anteriorly where the shelves show a marked convexity of their margins, and proceed posteriorly. The extreme posterior part of each shelf (future soft palate) is horizontal from the beginning. The matrix of the shelf mesenchyme (especially in the region of the anterior convexities) shows an increasing accumulation of mucopolysaccharides from day 14 to day 16.3 and becomes increasingly oedematous. The shelf attachment to the main maxillary process is progressively undercut by epithelial invagination, producing a fulcrum for shelf elevation. The maxillary and palatine osteogenic blastemata are present at the base of the shelf prior to elevation and rapidly invade the shelves after the event. The elevated palatal shelves fuse with the nasal septum anteriorly, but posteriorly the palate is not attached to the septum. The posterior septum at first has a free lower edge, but then it develops lateral flanges which fuse with corresponding bulges on the lateral nasal walls. In this way two sphenoethmoidal recesses are formed above the fused flanges, while a common nasal passage is formed above the palate, roofed anteriorly by the septal flanges and posteriorly by the cranial base. The space needed to create (simultaneous with shelf elevation) the common nasal passage is made available by flattening of the tongue and protrusion of its tip out of the oral cavity--this protrusion being facilitated by the sloping bulge of the primary palate and nasal septum. Many existing theories of shelf elevation are inconsistent with these observations. It was concluded that shelf elevation occurs very rapidly at a rather precise developmental stage and that turgor (due to binding of water to mucopolysaccharides) is the intrinsic force which elevates the shelves, a force which at 16.4 days reaches a threshold level enabling the shelves to force their way up and over the intervening tongue.


An ultrastructural study of the thyroid gland in the pre-metamorphic Xenopus laevis (Daudin) tadpole.

A simple method for obtaining the thyroid tissue of anuran tadpoles for ultrastructural study has been described. Follicle and colloid formation in the thyroid gland have been observed in Xenopus laevis tadpoles at an early stage. The activity of the thyroid gland of pre-metamorphic tadpoles does not seem to depend on the activity of the hypophysis cerebri and the hypothalamus. Both 'light' and 'parafollicular' cells are present in the thyroid gland of premetamorphic Xenopus laevis tadpoles.


The position of the nutrient foramen in the growing tibia and femur of the rat.

In rats of 40, 49 and 59 days of age the positions of the femoral and tibial nutrient foramina were determined by direct measurement, using a travelling microscope. The femoral nutrient foramen remained constant in position with increasing age, whereas the tibial nutrient foramen moved relatively nearer to the distal end of the shaft. In the case of the femur this can be accounted for entirely by differences in growth rates at the epiphyseal plates of the femur compensating for the disproportion in the distances of the foramen from the two plates. In the tibia, however, extension of the extremely oblique nutrient canal as the bone increases in girth is also involved. Bone remodelling in the vicinity of the canal is not necessary to explain the results.


The olfactory apparatus of the bandicoot (Isoodon macrourus): fine structure and presence of a septal olfactory organ.

The structure and extent of olfactory epithelium in the bandicoot (Isoodon macrourus) were examined by light and electron microscopy. Sensory epithelium covers most of the dorsal conchae, though non-sensory epithelium lines ventrally facing scrolls. The middle conchae are partly covered by olfactory epithelium, the proportion of olfactory to ciliated respiratory epithelium increasing caudally. Ventral conchae are lined by non-sensory ciliated epithelium. The nasal septum ends short of the floor of the nasal cavity in its caudal two thirds. It is covered dorsally by olfactory epithelium. The ventral margin has rounded lateral extensions which carry the isolated strips of olfactory epithelium which form the septal olfactory organ. The fine structure of the olfactory epithelium is the same in all areas. Cell types include olfactory receptors, supporting cells, two types of basal cell and rarer pale and brush cells. There is considerable morphological variation in olfactory cells, and evidence suggestive of continuing turnover in the receptor cell population.


Sheathing of collagen fibrils in human intervertebral discs.

In 25 human intervertebral discs studied by electron microscopy, sheathing collagen-like fibrils by electron-dense cylinders was observed. The sheaths consisted of layers of dense granules 3 to 12 times the diameter of the enclosed collagen-like fibrils, and they appeared to be more frequent in older discs.


Greater sciatic notch in sex determination.

Various measurements of the greater sciatic notch, e.g. width, depth and length of the posterior segment (of width) were measured, and indices I and II calculated, in 200 adult hip bones (120 males and 80 females). Total and posterior angles were measured after construction of a triangle from the above measurements in each case. Demarking points for sexing of hip bones were calculated for the above seven parameters on the lines of Jit & Singh (1966). Width and depth of the greater sciatic notch were found to be useless criteria for sexing purposes while the posterior angle was found to be the best parameter, which identified 75% of left and 88% of right male hip bones and 92% of left and 100% of right female bones. Length of the posterior segment and Index II also assigned sex to a high percentage of hip bones, especially to the female ones (95-97%), which suggests that the widening of the greater sciatic notch found in females has occurred primarily in its posterior part. The demarking points identify sex with 100% accuracy.


Studies on the nature of the peripheral sudomotor control mechanism.

Electron microscopical studies of the sweat glands of the body surface of the cow, sheep, goat and cat demonstrated that there were few nerves or blood vessels near the glands. No varicosities were found within 10 micron of the glands, and the small number of unmyelinated nerve bundles traced were over 1.5 micron from the glandular myoepithelium, and situated outside a fibrocyte sheath surrounding the glands. It was concluded that the sweat glands of these species are not innervated. Unmyelinated nerve fibres were more abundant around, and were closer to, the sweat glands of man, the horse and cat footpads, and varicosities were observed within the fibrocyte sheath close enough to have a direct influence on the glands. It is postulated from the comparative evidence that the basic sudomotor mechanism is the same in all species, involving the action of adrenergic and cholinergic nerves on the cutaneous blood vessels and local catecholamine transfer to the gland; and that in species such as man where the blood supply and sympathetic nerves are in close proximity to the glands, transmitters released at the sympathetic nerve endings, in particular acetylcholine, will, in addition, have a direct action on the glands.


Some ultrastructural characteristics of the renal artery and abdominal aorta in the rat.

The rat renal artery and abdominal aorta have been studied by light and electron microscopy. In rats of 200 g body weight the extracellular space in aortic media ranges between 50-60% and that of the distal renal artery between 15-25%. The surface to volume ratio of aortic smooth muscle cells is 2.7 micron2/micron3 compared to 1.6 micron2/micron3 in the distal renal artery. Dense bodies are rare in aortic smooth muscle cells but are abundant in those of the distal renal artery. Other ultrastructural details of the smooth muscle cells are similar in the two types of artery. Cell-to-cell contacts consist of simple apposition of plasm membranes and their number is proportional to the total length of cell membrane profile. Mitochondria represent 7-8% of the cell volume in both arteries. The proximal renal artery shows structural characteristics which are intermediate between those of the aorta and distal renal artery. In all renal arteries examined, bands of longitudinal smooth muscle are present in the adventitia, principally at branch points. In older rats, regions of discontinuity of the internal elastic lamina have been observed.


Simplified fat extraction with sulfuric acid as cleanup procedure for residue determination of chlorinated hydrocarbons in butter.

A new cleanup procedure is described for chlorinated hydrocarbon residues in butterfat. The method is based on the dropwise addition of H2SO4 to a fat solution column and continuous removal of the lipids and the acid. The cleanup of 0.25-2.0 g fat requires only 10-40 ml sulfuric acid and 12-17 ml petroleum ether. There is no need for any further cleanup step, solvent evaporation, or centrifugation. The method is easy to standardize and is suitable for automation. At least 30 fat samples can be cleaned up manually by one analyst in one day. Recoveries were complete (greater than 90%) for polychlorinated biphenyl compounds and for 13 chlorinated pesticides of 16 examined. The method was tested on chlorinated hydrocarbon residues in commercial butter and the results were compared with those obtained with the acetonitrile method. The versatility and limitations of the method were investigated by varying the sulfuric acid strength, initial fat solution concentration, and column dimensions.


Analysis of fat-soluble vitamins. XIX. Collaborative studies on the chemical assay for vitamin D concentrates.

In 1971, a chemical method for the assay of vitamin D in concentrates containing only vitamin D was collaboratively studied by 14 laboratories, using 6 different samples from 2 European manufacturers. On the basis of these results, the laboratories were divided into 2 groups: 5 with significant laboratory biases of greater than or equal to 2%, and 9 laboratories with nonsignificant bias. The 9 laboratories were subdivided into 2 groups which differed significantly as to reproducibility within laboratories. The reproducibility between laboratories, expressed as a standard deviation in per cent with 95% confidence limits, was 1.2% (confidence range 0.6-7.3) and 4.7% (confidence range 2.4-29.3) for 3 and 6 laboratories, respectively. A second collaborative test was performed in 1974, using 12 vitamin D resin samples in oil from 3 United States manufacturers, to compare 2 chemical vitamin D assay methods (with and without maleic anhydride) and to compare results from the chemical  and biological methods; 9 laboratories participated in the chemical method study and 3 in the rat bioassay study. The correlation of results of the chemical method including maleic anhydride treatment and the rat bioassays was satisfactory. The reproducibility of the chemical method was about the same as that in the first collaborative test.


Psychotic behavior in children under the institutions for mentally retarded in Denmark.

The purpose of this research project was to identify children with psychotic behavior in the Institutions for the Mentally Retarded in Denmark and to analyze psychotic behavior. The subjects for study were 392 children, partly selected as a representative sample, partly selected as a sample of children with psychotic behavior. A combined observation and interview scheme was constructed containing 17 behavioral items and 6 developmental scales. Scoring systems for psychotic behavior were constructed and their consistency analyzed by the Rasch item-analysis model. Two major behavioral dimensions, "bizarre behavior" and "psychotic withdrawal," were used for the diagnostic grouping of the subjects. The distributions of the children in regard to developmental retardation, organic brain damage, and psychiatric diagnoses were investigated. Conclusions regarding guidelines for reorganization of present services and establishment of new services are proposed.


Course and prognosis of childhood schizophrenia.

Follow-up data on 57 schizophrenic patients, including 25 boys and 32 girls between the ages of 7 and 13, is reported. Average length of follow-up was 15 years. Symptoms found in children under 10 and in prepubertal cases are described. Cases with acute, relapsing episodes occurred more often than chronic cases, but before age 11 acute cases were less frequent. Twenty percent of the patients recovered completely, 30% reached a relatively good social adjustment, and 50% had moderate or poor remission. Family incidence of psychiatric disorders had no influence on prognosis, nor did unfavorable family environment. Premorbid personality development was, however, found to be of prognostic value. Prodromal episodes occurred in 55% of the cases, and 65% of the patients were preoccupied by death. Additional follow-up findings are presented, and problems of diagnosis are discussed.


Development of communicative behavior in autistic children: a parent program using manual signs.

Mothers of four 6- and 7-year-old autistic classmates were taught to use manual signs for verbalizations to aid development of appropriate communicative behavior and to deter undesirable behavior in their children. The experimental treatment was initiated in a daily mother-child laboratory session using a multiple-baseline design across subjects. The preschool classroom program remained unchanged. Data were recorded for each child daily over a 5-week period, in the classroom and in a mother-child session, on four types of communicative behavior and four types of inappropriate behavior. Communicative behaviors increased and inappropriate behaviors decreased in relation to baseline conditions for each child. The manual sign program facilitated generalization of communicative behavior to the child's total environment. Desirable behaviors were maintained and had improved in the classroom 3 months after initiation of the program.


Paired associate learning in early infantile autism and receptive developmental aphasia.

A comparative study of nonverbal MA matched groups of five autistic, five aphasic, five normal and five retarded children was made on an auditory-visual and a visual-visual paired-associate learning task. The results showed that, although the autistic and receptive aphasic children were both unable to associate sounds with their visual counterparts at the same rate as normal children, the aphasic children overcame this deficit at a significantly faster rate than autistic children. This study pinpoints one dysfunction that could subsume the severe verbal comprehension defect in autistic and aphasic children.


Suppression of repetitive self-injurious behavior by contingent inhalation of aromatic ammonia.

Two institutionalized children who exhibited high rates of severely self-injurious behaviors were punished with aromatic ammonia inhalation on a response-contingent basis. This contingency was applied throughout all aspects of each child's institutional program which focused on teaching of self-help skills. Suppression of the self-injurious responses was both rapid and general. The contingency was maintained for 2 months, although there was no responding after the first 5 days. Follow-up sessions, conducted 4 months after the punishment contingency was removed, revealed that suppression effects were highly durable. Aromatic ammonia inhalation appears to be an effective alternative for decelerating extremely maladaptive behaviors that do not yield to more conventional nonaversive forms of therapy. However, the procedure should be used with great caution, for it may involve risk to the subject.


Systematic recording of behaviors and skills of retarded and psychotic children.

The design, administration, and scording of the first edition of the Children's Handicaps, Behavior & Skills (HBS) structural interview schedule, intended to elicit information concerning metally retarded or psychotic children, are described. A high level of reliability was achieved with experienced interviewers and good informants. In a study of 104 such children, the levels of overall agreement between parent and professional informants on the 62 sections of the schedule were, in general, 70% or above. Agreement was better for rating absence of skills or behavioral abnormalities than for rating their presence. This tendency was particularly marked for the behavioral abnormaliteis. Parents, when compared with professional workers, tended to describe their children as having higher developmental skills, more social contact but also more repetitive and difficult behavior.


Osmotic effects of membrane permeability in a marine bacterium.

When cells of Alteromonas haloplanktis 214 (ATCC 19855) were preloaded with alpha-[(14)C]aminoisobutyric acid or the K(+) in the cells was labeled with (42)K by incubation in a buffered salt solution containing 0.05 M MgSO(4), 0.01 M KCl, and 0.3 M NaCl, the cells retained their radioactivity when resuspended in the same salt solution. When NaCl was omitted from the solution, 80 to 90% of the radioactivity was lost from the cells. Cells suspended at intermediate concentrations of NaCl also lost radioactivity. New steady-state levels of the intracellular solutes were established within 15 s of suspending the cells; the percentage of radioactivity retained at each level decreased proportionately as the osmolality of the NaCl in the suspending solution decreased. With minor variations in effectiveness, MgCl(2), LiCl, and sucrose could substitute for NaCl on an equiosmolal basis for the retention of radioactivity by the cells. KCl, RbCl, and CsCl were appreciably less effective as replacements for NaCl, particularly when their osmolalities in the suspending solutions were low. The amount of alpha-[(14)C]aminoisobutyric acid taken up by the cells at the steady-state level increased to a maximum as the NaCl concentration in the suspending medium increased to 0.3 M. At suboptimal levels of NaCl, either LiCl or sucrose could substitute for NaCl in increasing the steady-state levels. The results obtained indicate that the porosity of the cytoplasmic membrane of this organism is determined by the difference between the osmotic pressure of the cytoplasm and the suspending medium. The lesser effectiveness of K(+), Rb(+), and Cs(+) than Na(+), Li, or Mg(2+) in permitting the retention of solutes by the cells is attributed to the greater penetrability of the hydrated ions of the former group through the dilated pores of a stretched cytoplasmic membrane.


Interrelationships of isoacceptor phenylalanine tRNA species of Rhodopseudomonas sphaeroides.

The phenylalanine tRNA of Rhodopseudomonas sphaeroides was fractionated on benzoylated diethylaminoethyl-cellulose into four isoaccepting species (tRNAPheI to IV). tRNAPheIII represented 80% of the total tRNAPhe in anaerobic, photosynthetically grown organisms, whereas in cultures grown aerobically for prolonged periods, tRNAPheII represented 80% of the total. In cultures adapting to aerobic growth, the addition of rifampin resulted in a tRNAPhe profile characteristic of anaerobic-photosynthetic conditions due to the conversion of tRNAPheII to tRNAPheIII. In fully adapted aerobic cultures, this conversion was inhibited in the presence of chloramphenicol or rifampin. The conversion of tRNAPheIII to tRNAPheII was not observable in vivo. It is proposed that an enzymic activity synthesized during anaerobic-photosynthetic growth was responsible for the conversion.


Fate of homospecific transforming DNA bound to Streptococcus sanguis.

The fate of [3H]DNA from Streptococcus sanguis str-r43 fus-s donors in [14C]S. sanguis str-s fus-r1 recipients was studied by examining the lysates prepared from such recipients at various times after 1 min of exposure to DNA. The lysates were analyzed in CsCl and 10 to 30% sucrose gradients; fractions from the gradients were tested for biological activity and sensitivity to nucleases, subjected to various treatments and retested for nuclease sensitivity, and run on 5 to 20% neutral and alkaline sucrose gradients. The results demonstrate that donor DNA bound to S. sanguis cells in a form resistant to exogenous deoxyribonuclease is initially single stranded and complexed to recipient material. Donor DNA can be removed from the complex upon treatment of the complex with Pronase, phenol, or isoamyl alcohol-chloroform. Within the complex, donor DNA is relatively insensitive to S1 endonuclease but can regain its sensitivity by treatment with phenol. With time the complex moves as a whole to associate physically with the recipient chromosome. After a noncovalent stage of synapsis, donor material is covalently bonded to and acquires the nuclease sensitivity of recipient DNA, while donor markers regain transforming activity and become linked to resident markers.


Physiological factors involved in the transformation of Mycobacterium smegmatis.

Transfer of streptomycin resistance and changes from methionine and leucine auxotrophy to prototrophy were achieved in Mycobacterium smegmatis by transformation. Recipient cells were more resistant to mitomycin C and methyl methlanesulfonate treatments than were wild-type cells. A high level of calcium ions was essential for transformation, especially during DNA adsorption, whereas the presence of magnesium ions and the exposure of recipient cells to mild doses of UV light enhanced recombination frequencies. Transformants were not isolated when recipient cell-DNA mixtures were first treated with deoxyribonuclease. Recipient cells at various stages of growth showed similar transformabilities. Transformation was successful only when recipient cells were incubated on rich agar medium after mixture with DNA. Exposure of recipient cells to Pronase before treatment with donor DNA did not affect transformation, suggesting the absence of a protein competence factor. Throughout the present experiments, cotransformation frequencies were very low and unselected-marker segregation patterns were independent, indicating that the methionine, leucine, and streptomycin markers are not closely linked in M. smegmatis.


Glucose metabolism and dimorphism in Mucor.

Mucor racemosus fermented glucose to ethanol, carbon dioxide, and glycerol. When this fungus was grown anaerobically in either the yeast or mycelial form, the catabolism of glucose was very similar. Yeast cells shifted to aerobic conditions maintained a high flux of glucose carbon through the glycolytic and pentose phosphate pathways. Mycelial cells grown aerobically catabolized glucose in a manner consistent with a respiratory metabolism. Although there was no consistent pattern of glucose metabolism in the mycelial form of Mucor, growth in the yeast form consistently was correlated with a high flux of glucose carbon through the catabolic pathways.


Potassium transport system of Rhodopseudomonas capsulata.

Rhodopseudomonas capsulata required potassium (or rubidium or cesium as analogs of potassium) for growth. These cations were actively accumulated by the cells by a process following Michaelis-Menten saturation kinetics. The monovalent cation transport system had Km's of 0.2 mM K+, 0.5 mM Rb+, and 2.6 mM Cs+. The rates of uptake of substrates by the potassium transport system varied with the age of the culture, although the affinity constant for the substrates remained constant. The maximal velocity of uptake of K+ was lower in aerobically grown cells than in photosynthetically grown cells, although the Km's for K+ and for Rb+ were about the same.


Divalent cation transport systems of Rhodopseudomonas capsulata.

Separate divalent cation transport systems for energy-dependent uptake of Mg2+ and Mn2+ were found both with aerobically and heterotrophically grown and with photosynthetically grown cells of Rhodopseudomonas capsulata. The maximum rate of Mg2+ uptake differed between photosynthetic and aerobic cells, while the Km for the Mg2+ transport system was constant. Photosynthetic midlog-phase cells exhibited Km's for uptake of about 55 micrometer Mg2+ and 0.5 micrometer Mn2+. The Vmax's also differed between the two systems: 0.6 to 1.8 mumol/min per g (dry weight) of cells for Mg2+, but only 0.020 mumol/min per g for Mn2+, making the distinction between a "macro-requirement" system and a system functioning at trace nutrient levels. Calcium was not normally taken up by intact cells of R. capsulata. However, chromatophore membranes isolated from photosynthetic cells took up Ca2+ by an energy-dependent process.


Adjacent insertion sequences IS2 and IS5 in bacteriophage Mu mutants and an IS5 in a lambda darg bacteriophage.

Using electron microscopic heteroduplex analysis, we have demonstrated that an insertion found in a Mu prophage and in some infectious. Mu deletion-substitution mutants derived from it consists of bacterial insertion sequence IS2 linked directly to IS5. Other infectious Mu mutants derived from the same lysogen have only IS5 or a portion of IS2. In addition, we have found that an independent insertion in a transducing phage, lambda 13 dargB2, is IS5. The ends of IS5 are short, inverted duplications of each other. These observations support the notion that the DNA insertion previously designated IS5 on the basis of a single example in lambda KH100 is a bona fide bacterial insertion sequence.


Penicillin-induced formation of osmotically stable spheroplasts in nongrowing Bdellovibrio bacteriovorus.

Bdellovibrio peptidoglycan is of typical gram-negative composition. The molar ratios of alanine:glutamic acid:diaminopimelic acid:muramic acid:glucosamine were about 2:1:1:1:1. Nascent, nongrowing Bdellovibrio bacteriovorus 109J were converted from highly motile vibrios to highly motile spheres when shaken in dilute buffer plus penicillin, cephalothin, bacitracin, or D-cycloserine. The spherical forms contained essentially no sedimentable peptidoglycan; i.e., they were spheroplasts. Spheroplasts induced by penicillin, D-cycloserine, and lysozyme were stable in dilute buffer and did not lyse when subjected to osmotic shock. Normal Bdellovibrio suspended in buffer turned over their peptidoglycan at a rate of approximately 30% h during the initial 120 min of starvation. Chloramphenicol and sodium azide strongly inhibited Bdellovibrio peptidoglycan turnover and the induction of spheroplasts by penicillin. The data indicate that nongrowing B. bacteriovorus are sensitive to penicillin and other antibiotics affecting cell walls because of their high rate of peptidoglycan turnover. It is also concluded that an intact peptidoglycan layer is required for maintaining cell shape, but is not required for osmotic stability of B. bacteriovorus.


Ultrastructural localization of Thermoplasma acidophilum surface carbohydrate by using concanavalin A.

Surface carbohydrate, presumably the lipopolysaccharide, of Thermoplasma acidophilum was visualized by means of the concanavalin A, horseradish peroxidase, and diaminobenzidine cytochemical staining procedure.