Surveying antibiotic use in a general teaching hospital.

Four antibiotic surveys were carried out in a teaching hospital within the framework of an intensive drug monitoring system during 1976-1978. The proportion of inpatients receiving antibiotic therapy at any one time varied from 25% to 32%. Penicillin, ampicillin and co-trimoxazole were the most frequently used antibiotics. The use of cloxacillin increased over the survey period. Approximately 85% of presumed infections were treated before the results of microbiological tests became available. Between 29% and 39% of all courses of antibiotics were given for prophylaxis of infection. Between 13% and 30% of patients received more than one antibiotic concurrently; indication for such combined use appeared inadequate in 31% to 80% of courses.


Cancer mortality in selected New South Wales localities with fluoridated and non-fluoridated water supplies.

The standardized cancer mortality ratios for selected localities in New South Wales with fluoridated and non-fluoridated water supplies were examined. The cancer mortality ratios for both fluoridated and non-fluoridated localities were spread along a continuum. Two localities (one fluoridated, one non-fluoridated) had standardized mortality ratios significantly lower than the New South Wales State average. No relationship was found between cancer deaths and whether water supplies had been fluoridated or not.


[Distribution of thermophilic sulfate reducing bacteria in the oil-bearing strata of Apsheron and Western Siberia].

Enrichment cultures of sulfate-reducing bacteria were obtained by inoculating the water of high-temperature gas and oil-bearing strata. A study of the morphology of these cells has shown that the thermophilic bacterium Desulfovibrio thermophilus occurs in the deposits of the Apsheron Peninsula while Desulfootomaculum nigrificans is found in the deposits of West Siberia. The former organism is involved in the accumulation of H2S in the Apsheron strata. The temperature of the strata is believed to be the factor which regulates the incidence of bacteria.


[Transformation of the herbicide 2,4-D in an Azotobacter culture].

Transformation of the herbicide 2,4-D[14C] was studied in the cultures of Azotobacter chroococcum, Azotobacter vinelandii and Azotobacter agile. These cultures assimilated 2,4-D and metabolized it. The products of transformation included phenol derivatives, water-soluble products, and carbon dioxide. About 15% of the herbicide taken up by the cells was bound to protein.


Renal pelvic carcinoma in the Hunter Valley.

In the Hunter Valley, New South Wales, the incidence of renal pelvic carcinoma was found to be very high, and there appeared to be a causal relationship with analgesic abuse. The crude incidence rate was calculated at 1.6/100000 population per year. In half of the cases of renal pelvic carcinoma, there was evidence of analgesic abuse and/or analgesic nephropathy with papillary necrosis; in this group the male/female ratio was 1/2.6, and there was a tendency for the cancers to occur at a younger age. Tumours associated with analgesic nephropathy were more often poorly differentiated and in a more advanced stage at the time of diagnosis than those not associated with analgesic nephropathy. Multiple tumours were equally common in both groups, but coexistent flat carcinoma in situ tended to be more common in cases associated with analgesic nephropathy.


[Effect of ubiquinones and their analogs on the respiratory chain enzyme activity of Candida guilliermondii yeasts].

The effect of ubiquinones with different length of their chain (CoQ0, CoQ1, CoQ2, CoQ6, CoQ9) and their synthetic analogues (analogues of ubiquinone-1, hexahydroubiquinone-4, monophytylquinone, diphytylquinone, triphytylquinone) on the activity of ubiquinone dependent enzyme systems was studied in mitochondrial fractions from the yeast Candida guilliermondii. All of the ubiquinone homologues studied activated these systems. The synthetic analogues of ubiquinone nonspecifically inhibited the activity of NADH2-oxidase system. The inhibition was reversible when CoQ0 and CoQ1, but not CoQ6 and CoQ9, were added to the system. In the succinate-CoQ-reductase system, the inhibition caused by the analogues of ubiquinone was eliminated when all of the tested homologues were added to the system. In contrast to other analogues of ubiquinone, hexahydroubiquinone-4 was an inhibitor for the NADH2-oxidase system and an activator for the succinate-CoQ-reductase system, and eliminated the inhibiting action of other ubiquinone analogues in this system. Similar action of ubiquinone homologues was shown in the elimination of the inhibition of ubiquinone dependent systems caused by the specific inhibitors of electron transport, viz. rotenone and antimycin A.


Retrospective survey of neurotraumatic admissions to a teaching hospital: comparison of data on spinal injuries after 10 to 16 years.

A retrospective survey of 202 patients with spine and cord injuries who were treated in the Prince Henry Hospital and the Prince of Wales Hospital from January, 1960, to December, 1965, was published in 1968. Ten years later, 98 patients with spine and cord injuries who were admitted over a two-year period (January, 1975, to December, 1976) were similarly studied. The data of the two surveys were compared, and changes in clinical and epidemiological features were evaluated.


Massive adrenal haemorrhage complicating adrenal neoplasm.

Two patients presented to hospital with clinical features of acute retroperitoneal haemorrhage. In each case, laparotomy revealed massive adrenal haemorrhage, and histological evidence of underlying neoplasia was eventually found.


Vechile-occupant fatalities after legislation for compulsory wearing of seat belts in Australia: different trends between the sexes.

The protective value of legislation for compulsory wearing of seat belts has been supported by Australian and overseas experience. An evaluation of changes during the period from 1957 to 1977 in the incidence of road crash fatalities for male and female vehicle occupants in Victoria and the rest of Australia (that is, in Australia minus Victoria) is presented. Reduction in the number of fatalities and the fatality rate in the number of fatalities per 10,000 vehicles) for vehicle occupants has resulted largely from statistically significant decreases for male drivers and adult passengers, especially females. However, the fatality rates have remained within the 95% confidence limits of expected post-legislation values for female drivers in Victoria and the rest of Australia, and for male adult passengers in the rest of Australia. There has been virtually no reduction in road crash fatalities for passengers less than 17 years of age. Hypotheses are advanced to explain these findings and further countermeasures are suggested.


Effective use of blood in elective surgical procedures.

The preoperative requests for crossmatching of blood in elective surgical procedures were studied at the Flinders Medical Centre, South Australia. The study revealed that surgeons order crossmatched blood on the basis of habit. This led to considerable time-expiry of blood, and to unnecessary use of laboratory personnel's time and reagents. The statistical information collected during the study was used to educate the surgeons to change their blood-ordering practice. In procedures where excessive blood loss is unlikely to occur, as a stand-by, a "group-and-screen" procedure was substituted for crossmatching. A firm recommendation for maximum blood order in elective surgical procedures was also made. It is estimated that this approach would save approximately $80,000 per year per 350-bed general hospital in Australia.


Abdominal aortic aneurysm: a review of 12 years surgical experience.

A personal series of 187 consecutive resections for abdominal aortic aneurysm between 1967 and 1979 has been reviewed. The cases are classified as elective, acute or ruptured. Aetiology, presenting symptoms, investigations, management, complications and deaths are discussed. The hospital mortality rate in elective and acute cases was 4.7%, and in ruptured aneurysms was 27.8%.


Trapped finger injury.

Forty-one patients with trapped finger injuries, 50% of whom were three years of age or younger, were studied. All patients were treated with a conservative regimen, and a satisfactory result in terms of the appearance and function was achieved in 95% of patients, thus eliminating the need for more complex surgical procedures. In the paediatric age group, a secure dressing is imperative for the satisfactory union of tissue. Such a regimen eliminates the need for hospital admission and general anaesthesia, and, in terms of the final result, supports the hypothesis that, in the very young, a certain amount of regeneration occurs to compensate for lost tissue.


Treatment of alcoholic lactic acidosis.

The treatment of lactic acidosis has been unsatisfactory in the past. The present paper describes the beneficial effects of treatment with thiamine in this condition.


Patterns of growth in Queensland schoolchildren, 1911 to 1976.

The heights, weights and skinfold thicknesses of 4466 Queensland schoolchildren, who were aged from six to 12 years and were measured in 1976, have been analysed and compared with the results of previous surveys conducted in 1911 and 1950. The 1976 study shows that Aboriginal children are generally smaller than Caucasian children, that Caucasian children in Queensland do not differ significantly from those in New South Wales, and that social class differences in stature have disappeared. Comparisons with the previous studies suggest that the secular increases in height and weight have become much smaller in the last 26 years.


Availability of schedule 3 preparations from community pharmacies.

A survey was conducted to determine the ease with which commonly misused schedule 3 (S3) preparations could be purchased from 29 randomly selected pharmacies. The proprietary formulations chosen for study were Phensedyl linctus, Avil tablets and Ponderax tablets. The regulations governing the sale of S3 preparations in South Australia state that they must be sold under the direct supervision of a registered pharmacist, but, in the majority of cases, this did not occur. In a follow-up study where pharmacists were questioned on their knowledge of the regulations, all indicated that they were aware of the details of the regulations and complied with them.


Late survival after coronary surgery.

One hundred and twenty-two patients have been followed for five to eight years after cardiac revascularization. The over-all mortality of 2% compares closely with the expected mortality of a normal population. Seventy percent of patients remain essentially angina free at an average follow-up period of six years. Late infarction, assuming all "coronary" deaths were so caused, occurred at a rate of 3.7% yearly.


Crystalluria during flucytosine therapy.

A case of urinary crystalluria occurring in a patient during treatment with flucytosine (5-fluorocytosine) is presented. A reduction in the dosage of the 5-fluorocytosine resulted in a marked decrease in the excretion of urinary gravel which was shown to be a coprecipitate of 5-fluorocytosine and uric acid.


Diarrhoea as a side effect of amoxycillin therapy.

The incidence of loose bowel actions in hospitalized children who were receiving amoxycillin mixture has been studied. A total of 293 patients were observed for the occurrence of loose bowel actions considered not to be due to their disease-state; some 19% of these patients suffered this side effect. The incidence was extremely high in the youngest children, but it diminished as age increased. A control group of patients showed a significantly lower (P less than 0.025) percentage incidence (7.4%) than children who were receiving amoxycillin mixture (18.8%). The dosage per kilogram of body weight per day was found to be unassociated with the incidence of diarrhoea in children below the age of two years; but above that age, children receiving higher doses of amoxycillin mixture were more likely to suffer this side effect than those receiving low doses.


Age and sex specific reference limits for carbohydrate tolerance.

Glucose estimations in the absence of diabetic symptoms may lead to diagnostic problems when clinicians are confronted with borderline results. This study on 28 581 estimations of post-prandial plasma glucose values gives age and sex specific reference limits derived from regression analysis at the 97.5 percentage point. A linear relationship exists between age and glucose tolerance in both sexes which is affected by the time of specimen collection. No evidence was found in support of bimodality; hence, it is believed that the observed diminution of carbohydrate tolerance with age is characteristic of the entire population.


Visual loss caused by corneal crystals in myeloma: rapid improvement and plasma exchange and chemotherapy.

Recognition of needle-like crystals in the cornea of a patient with deteriorating visual acuity initiated laboratory studies which demonstrated underlying multiple myeloma. Crystal deposition in the cornea occurs only rarely in multiple myeloma, and evidently reflects an unusual tendency for certain paraproteins to form numerous small aggregates which are deposited particularly within, and between, corneal epithelial cells. Treatment with chemotherapy, plus repeated plasma exchange with a normal plasma protein product resulted in significant depletion of crystals, and improvement in visual acuity over a period of three weeks. Accelerated clearance of paraprotein by plasmapheresis appeared to contribute materially to the rapidity of recovery, since recovery was considerably faster than in reported cases where treatment was with chemotherapy alone.


Female doctors in Victoria, 1977.

A survey of medical manpower in Victoria in 1977 revealed that 17% of registered medical practitioners were female and that the proportion of females was much higher among younger graduates. Seventy-eight per cent of female doctors were currently working in Victoria, compared with 82% of male doctors; 3.8% were "not working temporarily" compared with 0.6% of male doctors; and 3.9% were "retired" compared with 1.9% of male doctors. Female doctors accounted for only 8% of specialists in private practive, compared with 15% of general practitioners, more than 20% of salaried staff members of hospitals and other semigovernment and government bodies, and 40% of the staff members of community health centres. Thirty-eight per cent of female doctors were working part time. The need for part-time training programmes and part-time work, and the difficulties of female graduates becoming specialists are discussed. The implications of increasing proportions of female doctors entering the medical work force during the next decade, and the lower average working hours of female doctors compared with those of males, are considered in relation to the increasing supply of medical manpower in Australia.


Cholelithiasis: length-of-stay analysis in two series of surgical patients.

Two series of patients undergoing surgical treatment for cholelithiasis at Hornsby Hospital are described. Data are drawn from the routine morbidity reporting system of the hospital and processed by manual techniques. The morbidity data presented in this analysis demonstrate the capacity of currently operating reporting systems to provide diagnosis-specific information, and to describe the behaviour of relevant subgroups within a "diagnostic population". The need for specificity when attempting to make comparisons of length-of-stay "performance" either between or within hospitals is highlighted.


Colonization of an amputation site by Flavobacterium odoratum after gentamicin therapy.

Flavobacterium odoratum was isolated from the stumps of the amputated toes of a debilitated patient. Gentamicin therapy and the poor state of health of the patient provided suitable conditions for this gentamicin-resistant species to multiply. When the gentamicin therapy was stopped, and as the patient's heal improved, F. odoratum gradually disappeared to be replaced by Staphylococcus aureus. This appears to be the first report of the isolation of F. odoratum in Australia, and it indicates the potential of this resistant species to act as a source of infection for groups at risk.


Caesarean-section rates in Australia: a population-based audit.

Caesarean-section rates are increasing rapidly in Australia, and in many other Western countries. Private health-fund data for each State of Australia show marked differences in caesarean-section rates between States. Comparison between Western Australia and South Australia showed that these differences could be related to the proportion of specialist obstetricians per capita in each of the States. Although stillbirth rates are lower in the States with high caesarean-section rates, perinatal mortality rates, which include stillbirths, are not significantly different between States. Since the populations of Australian States are reasonably homogeneous, justification for performing more caesarean sections must be questioned.


Spontaneous abortions and terminations of pregnancy: histological differences.

Curettings from eight gravid uteri are compared with material curetted from 2081 uteri after spontaneous abortions. The outstanding feature of the spontaneous material is the decidual polymorph infiltrate. This was absent in seven of the termination specimens. The one case exhibiting a polymorph infiltrate showed other features of degeneration which suggested that a spontaneous abortion may have been developing before termination occurred. This difference between terminated and spontaneously aborted material may provide a basis for elucidating mechanisms in the latter.


Preventing poor-quality medical care: knowledge/action disconsonance.

Studies to evaluate quality of hospital care by means of the method of criteria auditing have yielded dubious results. More evidence of its efficiency and effectiveness should be sought before action to adapt or adopt such methods in Australia could be taken.


Initial changes in the free carbohydrate profile of rat lens and retina following streptozotocin-induced diabetes.

The changes in the concentration profile of free carbohydrates (glucose, sorbitol, fructose and myo-inositol) in rat lens and retina were studied in the first 5 days following induction of diabetes with streptozotocin. In both tissues, the total concentration of free carbohydrate increased markedly in this period. In the lens, the major component was sorbitol, whereas in the retina the major component was glucose. Myoinositol loss occurred only in the lens. The significance of these early changes in carbohydrate concentrations are discussed in relation to the development of subsequent metabolic derangements.


An inducible n-alkane hydroxylase system containing cytochrome "O" from Candida lipolytica.

In this work the terminal oxidase system of C. lipolytica grown on n-alkanes was identified, and partially purified. Spectral characteristics typical of cytochrome O are obtained, inhibition and photodissociation of CO are reported.


A rapid and sensitive method for detection of proteins in polyacrylamide SDS gels: staining with ethidium bromide.

We describe here a fluorometric method of detection of proteins fractionated by electrophoresis in polyacrylamide-SDS gels. This method, using ethidium bromide as fluorescent dye, is performed within 40 minutes after the end of the electrophoretic run. It does not require treatment of proteins prior to electrophoresis, and entails neither fixation of proteins in the gel, nor destaining. It is sufficiently sensitive to detect 0.5 - 1.0 microgram of protein per band. Furthermore, the simultaneous electrophoretic resolution and detection of protein and RNA on a single SDS-polyacrylamide gradient gel is reported.


Increased susceptibility of activated rat liver chromatin to DNAse I.

Rat liver chromatin activated by partial hepatectomy is more susceptible to the action of DNAse I than control chromatin isolated from intact liver. The study on the transfer of chromatin material to the acid-soluble fraction reveals a higher rate of activated chromatin degradation. Activated chromatin shows also an increased capacity for ethidium bromide (EB) binding as estimated from the isotherms of adsorption. The difference in EB binding between activated and control chromatin is abolished after DNAse I treatment. Conditions of mild digestion with DNAse I have been found under which the number of binding sites for EB per nucleotide decreases to almost the same level in activated and non-activated chromatin. The results suggest a preferential degradation of those DNA sequences in activated chromatin that are responsible for the increase in the ligand binding.


Tissue-specific ribosomal protein composition.

Membrane-bound and free polysomes from murine liver and kidney were isolated under identical conditions and their ribosomal proteins were compared by two-dimensional gel electrophoresis. The results demonstrate that these ribosome subpopulations are quantitatively and qualitatively similar except for the presence of one additional protein in the kidney-bound polysomal fraction.


Metabolically stable ribonucleoproteins in the chromatin of pigeon bone marrow cells.

Ribonucleoproteins with buoyant density 1.4 carrying metabolically stable RNA species with sedimentation coefficients up to 28S have been detected in the 0.35M NaCl extracts from pigeon bone marrow chromatin. It is suggested that they correspond to the slowly metabolizing interchromatin particles.


A simple and fast electrophoretic method for elution of nucleic acids from gels.

A very convenient electrophoretic procedure for DNA or RNA elution from agarose or polyacrylamide gels is described. The gel piece with nucleic acid to be eluted is contained in a dialysis bag filled with buffer and elution is carried out in a horizontal electrophoresis apparatus. The nucleic acid is recovered with a high yield and can be used, without prior treatment, in further enzymatic or chemical reactions. Results obtained with DNA are presented here.


Glutamate dehydrogenase activity in subcellular fractions of mouse fibrosarcoma.

Glutamate dehydrogenase activity was found to be present at a high level in neoplastic cytosol and microsomes, 3.45 and 9.90 nmoles NADH/min mg protein, respectively. This remains in accordance with the high rate of RNA and protein synthesis in the neoplastic process.


Histone: oxidation by peroxidase alters its interaction with DNA.

When histone is oxidized by peroxidase, its basicity (hence its complexing with DNA) is reduced: this reduction causes further alterations in the effect of histone upon the heat denaturation, acid precipitation, and breakdown by DNase of DNA, alterations which indicate that the regulation by histone of DNA expression may become abnormal. If oxidized species of histone should accumulate in the tissues in old age, the alteration mentioned might be a contributory factor of senescence.


[Regeneration of the proximal kidney tubules after sublimate-induced necrosis in the rate. Scanning electron microscopic studies].

Necrosis of the proximal tubules of the kidney in white rats has been produced by a relative small doses (1,5 mg/kg) of sublimate. Necrosis of the epithelial cells and their regeneration was studied during 10 days by scanning electron microscopy. Parallelism of the various regressive and regenerative processes was noted, attention was paid to the correlation existing between them. Periodicity of normal and necrotic segments was also observed. As a sequal of the necrosis the basement membranes became denuded, later in the first period of the regeneration flattened epithelial cells--having no microvilluses--covered them. On the surface of the latter, in a very short period (several hours) gradually microvilluses, regular brush-border and interdigitation of the cells were formed. In 10-17 days the regenerated epithelium could hardly be distinguished by scanning electron microscopy from the normal one.


[Electron microscopic changes in the liver in systemic lupus erythematosus].

Liver biopsy specimen of a patient with systemic lupus erythematosus was studied by light- and electron microscopy. On the background of the nonspecific hepatitis of a mild degree ultrastructural changes of the liver were revealed. Diffuse damage to the mitochondria and the vascular pole of the cells have been found. In the vascular endothelial cells of the liver presence of the so called tubuloreticular inclusions was observed. This can be regarded as the manifestation of the systematic disease in the liver.


[Scanning electron microscopy of oral leukoplakia].

Buccal mucosa of six patients with leukoplakia and normal controls was examined by scanning electron microscopy. Findings have shown that: 1. there is a difference between the surface epithelial cells of the normal mucosa and those of the mucosa with leukoplakia; 2. according to the various clinical forms of the leukoplakia there are differences between the epithelial cells: in leukoplakia verrucosa presence of keratinized epithelial cells, in leukoplakia erosiva absence of the cell-connecting structures seems to be a characteristic feature; 3. in leukoplakia erosiva with dysplasia atypical arrangement of the cytoplasmic processes of surface epithelial cells can be observed; 4. the most striking difference was revealed between the cells of the normal mucosa and those of leukoplakia erosiva.


[1st isolation of the Wright(a) erythrocyte antigen from Soviet blood donors].

Since the immunizing effect of rare erythrocytic antigens it is necessary to emphysize, that the same recipient should not get repeatedly erythrocyte-transfusion from the same donor.


[Isolation of immune complexes from the vascular wall in experimental immunovasculitis].

In experimental immunvasculitis immunocomplexes of the vessel wall have been detected by indirect immunofluorescence method. In the aortic intima linear deposition, in the small arteries and arterioles segmental fluorescence was observed in all layers of the vessel wall. In some regions a marked positive perivascular reaction was also revealed. Immuncomplexes of the vessel wall may play a part in the preservation and prolongation of the alterations of the vessel wall.


[Causes and possible prevention of motorcycle accidents].

Author reviews the main causes of motorcycle-accidents, the most frequent types of injuries with regard to their rate, severity and localization. Executive and technical ways of prevention are briefly reported.


[Experimental model for the study of the teratogenic interaction of chemical agents and drugs (toluene and acetylsalicylic acid)].

On the 10th-13th days of pregnancy toluene (3600 mg/m3) by inhalation) and on 12th day acetylsalicylic acid (500 mg/kg of body weight per os) were administered to CFY rats and the common effect of these agents was studied. It was established that: 1. the maternal toxicity increased, i.e. increased the mortality rate, decreased the consumption of the food and the gain of weight, increased the relative weight of the liver; 2. the foetal toxicity increased, i.e. increased the mortality rate of foetuses, the rate of the loss of the body weight, the number of the anomalies of the sternum and the incidence of the supernumerary ribs. It is believed, that the non-teratogenic toluene rises the utilization of the glycine and the level of the free salicylic-acid, consequently the embryotoxic effect of the acetylsalicylic-acid. The danger of the occurrence of malformations as an effect of interaction of chemical agents and drugs taken in therapeutic doses is stressed.


[The use of ethyl acetate for the embedding of tissue specimen].

Author for the prevention of detrimental health effects of benzene-homologs instead of xylene recommends the use of aethyl-acetate for the embedding process. It dissolves the warm paraffin, easily evaporates, mingles with acetone and isopropyl-alcohol and does not harden the tissue specimens.


[Medico-legal aspects of complications of the puncturing of the subclavian vein].

Three fatal cases of the puncture of the vena subclavia are reported and medicolegal aspects of this emergency operation are discussed. Punctures of the vena subclavia--as an emergency operation--has no contraindications. Undesirable consequences, when the operation was carried out with due skills and in due circumstances--will not provide grounds for negligence.


Tissue distribution of radioactivity from ochratoxin A-14C in rats.

Examination of the distribution of radioactivity in rat tissues during the first 24 hr after administration of ochratoxin A-14C demonstrated maximum accumulation in stomach and kidney. The highest counts were observed in stomach, lung, kidney, thymus, spleen and heart during the first 6 hr after treatment, whereas the brain, liver muscle, duodenum, jejunum, ileum, and cecum exhibited the greatest counts at 18 hr after toxin exposure.


Influence of trace elements and nitrogen sources on versicolorin production by a mutant strain of Aspergillus parasiticus.

A mutant strain of Aspergillus parasiticus blocked in aflatoxin biosynthesis accumulates versicolorin A and versicolorin C. The effect of trace elements on the growth and versicolorin production by this strain was studied in a defined medium. The omission of manganese was slightly stimulatory to versicolorin production; when zinc was omitted from the medium, no detectable versicolorins were produced. Experiments on nitrogen sources in a high-sucrose medium indicated that fourfold to fivefold increases in versicolorin yields could be obtained by substituting 3 ml/l corn steep liquor or 0.1 M NH4NO3 for the 0.023 M (NH4)2SO3 used previously as the nitrogen source in studies on versicolorin production by this strain. These improved yields will facilitate attempts to accumulate enough versicolorin A and versicolorin C for toxicity and carcinogenicity testing. Chromatographic profiles of mycelial extracts of cultures grown in a defined medium with 0.1 M NH4NO3 as the nitrogen source revealed 2 previously unrecognized compounds. The accumulation of these new metabolites in a mutant blocked in aflatoxin production may indicate that they are biosynthetically related to aflatoxin.


Spore ultrastructure in Sporothrix schenckii.

Pathogenic strains of Sporothrix schenkii may show triangular spores, whose angular shape is maintained by a tie-beam effect in the inner cell wall structure. This difference in wall structure lies adjacent to a folded and possibly more active part of the spore cytoplasm. The supposed generation of asci in old cultures was simulated by the death of hyphae which are reinvaded by intrahyphal growth with intrahyphal spore production, while true asci were not seen.


Is dopamine-sensitive adenylate cyclase involved in regulating the activity of striatal cholinergic neurons?

The dopamine (DA)-receptor mediated changes in striatal acetylcholine (ACh) levels have been studied to determine if this effect involves a D1-(adenylate cyclase dependent) or D2-(not linked to an adenylate cyclase) type of DA-receptor, Various DA-agonists (apomorphine, N-diphenethylamine derivatives) increased striatal ACh levels in both intact and 6-OHDA lesioned rats whereas only apomorphine stimulated the adenylate cyclase activity of striatal homogenates. The N-diphenethylamine compounds (RU 24213, RU 24926 and RU 26933) were without effect either on basal or DA-stimulated activities of this enzyme. In contrast, D-LSD (which acts as a partial agonist of the striatal DA-sensitive adenylate cyclase) did not modify the striatal ACh content. More interestingly, an intrastriatal injection of cholera toxin greatly stimulated striatal adenylate cyclase without altering ACh concentrations. Both haloperidol and methergoline antagonized the DA stimulation of adenylate cyclase, but only haloperidol decreased striatal ACh levels. These results indicate that the DA receptor involved in regulating the activity of striatal cholinergic neurons is of the D2-type.


The longitudinal intraluminal concentration gradient in the perfused rat jejunum and the appropriate mean concentration for calculation of the absorption rate.

In anaesthetized rats, jejunal segments 30 cm in length were perfused (rates:0.1, 0.2,0.5 ml/min) with solutions containing antipyrine, salicylic acid, urea, L-lysine, L- and D-phenylalanine. The intraluminal concentration was determined approx. 10, 20, and 30 cm from the inflow cannula. The intraluminal concentration gradients were almost exponential and corresponded to the gradient predicted for a laminar flow through a solute-permeable circular tube. This gradient has a slightly greater curvature than the exponential one. Theoretical considerations showed that the logarithmic mean (Co-Cz)/ln(Co/Cz) of the in- and outflow concentration is the best average value for application in non-integrated absorption equations. This is also valid for the temporal concentration gradient after single administration of a substance into an intestinal segment.


The regional localization of R28935 in the cat brain as dependent on the route of administration.

Intravenous injection of the antihypertensive agent R2835 and its pharmacologically less active threo-isomer R29814 resulted in a distribution profile in the cat brain which differed from the regional localization after administration via the left vertebral artery. Although the two isomers had the same physico-chemical properties, R28935 penetrated more readily into the CNS. Intravenous administration resulted in almost equal levels in all brain parts, whereas after injection into the vertebral artery caudal structures contained more of both compounds that rostral structures. Differences existed between the concentrations in homotopic brain areas, especially in the brain stem. From comparison of the levels of R28935 after injection of an equiactive dose either i.v. or into the vertebral artery it is tempting to speculate that the mesencephalic tegmentum, the nucleus of the solitary tract, the inferior colliculi and/or the locus coeruleus are possible sites of the hypotensive action.


Effects of ethacrynic acid on electrolyte and fluid transport by the guinea pig gallbladder.

The effect of ethacrynic acid on fluid and electrolyte transport by the guinea pig gallbladder was investigated in vitro. 10-4M ethacrynic acid, applied to the serosal side, inhibited fluid and sodium chloride absorption. The reduction in salt absorption was accounted for by a 3 muEq/cm2h decrease in the unidirectional fluxes of Na and Cl from mucosa to serosa with no change in the fluxes from serosa to mucosa. Ethacrynic acid (10-4 M) had no effect on HCO3 - Cl exchange, PGE1-induced fluid secretion and inulin permeability. At 10-3 M, ethacrynic acid markedly increased both the serosa to mucosa fluxes of Na and Cl, and the inulin permeability. Examination by light and electron microscopy of gallbladder tissue treated with 10-3 M ethacrynic acid revealed large intracellular vacuoles and occasionally ruptured apical cell membranes. Only slight morphological changes were seen by 10-4 M ethacrynic acid with no changes in the controls and ouabain treated gallbladders. The effects of ethacrynic acid are remarkably different from those of furosemide which has been previously shown to inhibit only the HCO3 secretion leaving fluid and NaCl absorption unchanged.


In vitro and in vivo disposition of 3H-methiothepin in brain tissues. Relationship to the effects of acute treatment with methiothepin on central serotoninergic receptors.

A single treatment with a large dose of methiothepin (20 mg/kg, i.p.) induced, as early as the 2nd day after injection, a significant increase (+20--35%) in the number of specific binding sites for 3H-5-HT in forebrain areas, particularly the hippocampus. Experiments with 3H-methiothepin indicated that the drug remained firmly bound to brain membranes thus maintaining a local concentration high enough to effectively block 5-HT receptors for 10--12 h after its peripheral administration. Accordingly, it can be concluded that the occupancy of central 5-HT receptor sites by methiothepin for several hours was sufficient to induce a supersensitivity phenomenon within the two following days. Although 3H-methiothepin was a useful marker for analyzing the disposition and the kinetics of the 5-HT antagonist in brain tissues, it could not be used as a specific ligand of 5-HT receptors in brain since under in vitro as well as in vivo conditions most of 3H-methiothepin bound to non-specific sites, especially to the lipid component of the membranes.


The synthesis of prostaglandins and thromboxane in the mouse brain in vivo. Influence of drug induced convulsions, hypoxia and the anticonvulsants trimethadione and diazepam.

1. The i.v. administration of convulsant doses of penetrazole or picrotoxin induced an increase in PGF2 alpha, PGE2 and TXB2-like immunoreactive material in mouse brain tissue. The onset of increase coincided with the appearance of clonic seizures. 2. The anticonvulsant drugs trimethadione and diazepam reduced both convulsions and increase of the above arachidonic acid metabolites induced by pentetrazole or picrotoxin. 3. In synaptosomal preparations of the brain, neither pentetrazole (10(-3) mol 1(-1) picrotoxin (10(-4) mol 1(-1) nor trimethadione (5 x 10(-4) mol 1(-1)) had any influence on cyclooxygenase activity as indicated by the unimpaired PGF2 alpha-synthesis. 4. Under hypoxic conditions at equal durations as the seizures, the formation of PGF2 alpha and PGE2 was less than 10% of the amount occurring after penetrazole-induced convulsions. 5. It is concluded that the seizure-induced rise of PGF2 alpha, PGE2 and TXB2 is the result of increased central nervous activity.


Effect of cryptands on cardiac Purkinje fibres.

Cryptands are possibly useful synthetical models for passive ion carriers in biomembranes. Five mainly Na+ and K+ complex forming cryptands were studied in cardiac Purkinje fibres by means of standard microelectrode technique. Even at high concentrations the cryptands 22, 221 and 222 showed no effect. Possibly they are not lipophilic enough to accumulate within the membrane. The more lipophilic cryptands 222B and 222D caused a decrease of overshoot and maximal rate of rise (Vmax), a pronounced loss of plateau and a shortening of the action potential, while the resting potential was only slightly depolarized. 222B made some fibres inexcitable at normal resting potentials; only by increase in stimulation voltage a regular response was obtained. After about 20 min both cryptands (5 x 10(-5) mol/l) depolarized the fibres leading to irreversible inexcitability. The availability of the fast sodium current ("h infinity"-curve) was measured using Weidmann's (1955) technique. With 222B the h infinity-curve-showed a shift in the hyperpolarizing direction, and the maximal Vmax was diminished.


Extracellular 5-hydroxytryptamine inhibits 5-hydroxytryptamine release from rat brain cortex slices.

Rat brain cortex slices preincubated with 3H-5-hydroxytryptamine were superfused with physiological salt solution and stimulated electrically, or they were superfused with Ca2+-free solution containing 25 mM K+ and stimulated by introduction of 1.3 mM CaCl2 for 2 min. After blockade of neuronal 5-hydroxy-tryptamine (5-HT) uptake with clomipramine or paroxetine, the 3H overflow evoked by both methods of stimulation was decreased by unlabelled 5-HT and increased by methiothepin. The inhibition caused by 5-HT was antagonized by simultaneous administration of methiothepin. The inhibition by 5-HT of Ca2+-induced overflow was also observed in the presence of tetrodotoxin. These results suggest that 5-HT regulates its own release from central serotoninergic neurones by activating presynaptic 5-HT autoreceptors, thus decreasing the availability of Ca2+ for stimulus-release coupling.


Pharmacokinetics of dihydrodigitoxin in the cat. A comparison with digitoxin.

Pharmacokinetics of digitoxin (DGT) and its derivative hydrogenated at the unsaturated lactone ring have been studied using the 3H-labelled compounds in cats. Blood level data could be described by an open three compartment body model. The biological half-lives of dihydrodigitoxin (DH-DGT) and DGT are rather similar (0.12, 0.48, 20.4 h, and 0.11, 0.43, 31.8 h, respectively), whereas the volume of distribution of DH-DGT is about 1/10 from that of DGT (0.241 versus 2.581). Especially in myocardial tissue a significantly lower DH-DGT concentration was measured, indicating the loss of affinity to cardenolide binding sites by hydrogenation. Dihydrodigitoxinic acid was detected as the main metabolite of DH-DGT.


The influence of 5-nitro-2-furyl acrylic acid on human fibroblasts cultivated in vitro.

The authors studied the in vitro effects of 5-nitro-2-furyl acrylic acid on growth activity of EUE human fibroblasts. They investigated the course and intensity of macromolecular syntheses, mainly DNA synthesis in these cells. Going by the results obtained it can be concluded that the cytotoxic effects of 5-nitro-2-furyl acrylic acid are also connected with its genotoxic effects, since that substance will induce damage to DNA in human cells.


Cell proliferation in the thymus of Ehrlich ascites tumor bearing mice.

Thymic involution of Ehrlich ascites tumor bearing Swiss and NMRI mice was associated with an increased incorporation of 3H-thymidine into thymus DNA and an enhanced activity of adenosine deaminase. The apparent depletion time constants, which were determined by the following time course of the retention of 3H-DNA, indicated that the rate cell depletion was increased in the thymus of tumor bearing mice. The results suggest that the thymic involution was correlated with an increased proliferative activity and an accelerated depletion of thymic cells.


The prognostic value of serum innumoglobulin levels in Hodgkin's disease.

Serum immunoglobulin concentrations have been measured in 31 patients with Hodgkin's lymphoma and related to disease activity and clinical stage. The patients with active untreated disease, the mean IgA concentration was significantly above the normal mean level and the mean IgM concentration was normal. No significant correlation was found between high IgA concentrations and liver involvement. There were decreased mean IgA and IgM concentrations during remission. The changes in immunoglobulin concentrations were found to be dependent on the clinical stage. The data suggest that in certain patients with active Hodgkin's lymphoma, the humoral-mediated immunity may be affected in addition to the cellular-mediated immunity.


Does lymphography promote dissemination of tumorous disease?

In two groups of patients with malignant melanoma on the lower limb and with metastases in the inguinal lymph nodes the authors followed the time of appearance of lung metastases and the survival time. In one group lymphography of the extremity was performed, the other one served as a control. Tabulated time data were mutually evaluated between the two groups by the parametric T-test and with the aid of the nonparametric Me-test. No significant difference was found between the two groups, not even with 20% probability. Thus, lymphography is not likely to have an influence on deissemination of malignant melanoma.


Combination of lymph node and lung metastases in thyroid cancer.

In thyroid cancer patients with pulmonary metastasis lymph nodes involvement was found in 62.6%. The incidence of lymph nodes metastases is discussed in relation to the age of patients and to the stage of the disease.


[Roentgenological aspect of the basilar artery and its significance in clinical diagnosis--angiographical study a of the basilar artery (author's transl)].

Topometric study of basilar arteries was performed, using 130 normal vertebral angiograms of cases consisting of 83 males and 47 females aged 2 to 67 (mean = 38.1). The cases having clinically and/or neuroradiologically had obvious positive findings such as cerebral atrophies, cerebrovascular diseases and space-taking lesions were excluded. Selective vertebral angiography using Seldinger's technique in 120 cases and retrograde brachial angiography in remaining 10 cases was carried out. The following results were obtained. 1) The position of vertebrobasilar junction was almost at the midline in frontal view with a mean distance of 0.3 mm +/- 3.6 leftward from the midline. 2) The length of basilar artery was 25.5 mm +/- 6.6 in frontal view and 32.8 mm +/- 5.8 in lateral view. 3) The position of basilar bifurcation was almost at the midline in frontal view with a mean of 0.0 mm +/- 2.0 from the midline, and 9.3 mm +/- 4.7 above the Twining's line and 24.5 mm +/- 3.4 posterior from tuberculum sellae in lateral view. 4) As for the configulation of basilar artery in frontal view, 'straight type' was common in young age and 'curved type' in old age. 'Curved type' was divided into four subtypes. The concave rightwards curved type and/ or the reversed S-formed tortuous type were almost twice many as the concave leftwards curved type and/or the S-formed tortuous type. This result seemed to support the reports on the hemodynamic mechanism of verteral arteries that the dominant flow was present on the left side at the rate of 50 to 80%. 5) Internal diameter of basilar artery at the point of 1 cm proximal to the apex was measured. The mean value was 3.3 mm +/- 0.6 in frontal view and 3.2 mm +/- 0.5 in lateral view. Maximum diameter of basilar artery was 3.5 mm +/- 0.7 in frontal view and 3.6 mm +/- 0.6 in lateral view.


[Computed tomography in the diagnosis of spinal disease (author's transl)].

During the period from October 1977 through February 1979, 41 cases of spinal diseases were studied by either EMI Whole Body Scanner, CT 5005 or EMI Head Scanner, CT 1010. Slices were 10 mm or 13 mm thick. (1) disc diseases 15 cases (2) ossification of posterior longitudinal ligament 10 (3) congenital anomalies 5 (4) spinal cord tumors 6 (5) trauma 3 (6) narrow cervical spinal canal 3 (7) calcification of ligamentum flavum 1 (8) spinal arteriovenous malformation 1. Results obtained are as follows: 1) A precise determination of vertebral level scanned by C.T. is important. 2) Plain spinal C.T. is of diagnostic value in detecting bony lesions and lipoma. Meningioma showed positive images in the enhanced spinal C.T. 3) The spinal cord cannot be distinguished from the surrounding C.S.F. except for that at C1 level. 4) C.T. metrizamide myelography can appraise adjacent structures that may impinge on the spinal subarachnoid space, as well as structures contained in the space.


[Vitreous hemorrhage as a complication of subarachnoid hemorrhage (Terson's syndrome) (author's transl)].

We represent a case of vitreous hemorrhage due to subarachnoid hemorrhage from a ruptured aneurysm of the right vertebral artery to draw attention to this complication. A 53-year-old man was admitted to our hospital because of generalized headache and reduced visual acuity of both eyes. On admission the patient was alert and there were moderate nuchal stiffness and mild symmetrical hyperreflexia in the extremities. Ophthalmological consultation revealed bilateral retinal, subhyaloid and vitreous hemorrhages. Four-vessel angiography demonstrated an aneurysm of the right vertebral artery. At operation, it became clear that the aneurysm was a dissecting one. The vertebral artery was clipped at the most proximal intracranial portion. Postoperative course was smooth and uneventful except deteriorated visual acuity. His visual acuity deteriorated continuously to hand movements 18 days after subarachnoid hemorrhage. His visual acuity, however, gradually improved without specific treatment. At the time of  this writing, his visual acuity is 1.0 on both sides. Vitreous hemorrhage is a rare complication following a reptured aneurysm. Pertinent literature concerning fundal hemorrhage, especially vitreous hemorrhage, associated with subarachnoid hemorrhage suggests that it may occur as a result of sudden increase of intracranial pressure.


[A case of accessory middle cerebral artery associated with internal carotid artery aneurysm (author's transl)].

A case of accessory middle cerebral artery associated with internal carotid artery aneurysm was reported. A 50-year-old female was admitted to our hospital with complaints of headache, nausea, vomiting and conciousness disturbance. Lumbar puncture showed bloody CSF. Right carotid angiogram revealed saccular aneurysm of the internal carotid-posterior communicating artery and accessory middle cerebral artery originating from the horizontal portion of the right anterior cerebral artery. No other vascular lesion was observed on other angiograms. Operation was performed 2 days after admission. The neck of the aneurysm was clipped. Postoperative aseptic meningitis was cured by frequent lumbar punctures, and her course was uneventful. The etiological hypothesis of these cerebral vascular anomalies was briefly discussed.


[A case of spontaneous hematomyelia (author's transl)].

A case of spontaneous hematomyelia was reported with a review of the literature. A 39-year-old woman, with sudden onset of pain in her left neck and arm 13 days previously, presented with a progressive flaccid tetraplegia below C5, dissociated sensory loss from C7 through Th4 dermatome and a minimal deep sensory loss in her right leg. Myelography revealed a symmetrical enlargement of the spinal cord at the leve of C5, C6 and C7. Laminectomy was performed and intramedullary blood clot, which was located in the region of C6 and C7, was evacuated. However, there were no vascular anomalies not only in macroscopic findings but also in histological examination. The postoperative course was uneventful and the patient gradually improved in her motility. At 5 month' follow-up examination she continued to do well with a minimal sensory loss of all modalities below the level of C7. Report of 16 patients with spontaneous hematomyelia including our case have been reviewed. Incidence of spontaneous hematomyelia without vascular anomalies or hemorrhagic diathesis very rare, being found in only 4 cases. In cases with good outcome the intramedullary hematoma was found to be located below the lower cervical region and limited within 2 spinal segments in its extent. Good postoperative results were obtained in 5 out of 7 patients who received surgical intervention, suggesting an essential importance of early diagnosis and surgery.


Persistence of the synkinetic patterns of the cervical spine.

The typical features of the sagittal synkinetic patterns shown on anteroposterior pictures after returning the head and neck from maximum lateral inclination to the neutral position, as well as the possibility to remove them by means of manual mobilisation, seem to indicate that they represent the residua of synkineses in the sagittal plane. From this point of view there exists a fundamental difference between kineses and synkineses, the latter being, by contrast, characterised by a very small range but a relatively great tendency to persist. The possible role of these phenomena in the pathogenesis of segmental blockades is discussed.


Comparison of consistency of meningiomas and CT appearances.

Computed tomograms of meningiomas in which the consistency of the tumour had been specifically noted at surgery were reviewed. Those showing diffuse calcification or evidence of marked cystic or necrotic changes were excluded, leaving 77 tumours of which 46 were hard and 31 soft. Ninety per cent of the hard tumours were of increased attenuation; the other 10% were isodense with brain. Forty-nine per cent of the soft meningiomas were of high attenuation, but 35% were isodense and 16% were of lower than brain attenuation. There was a greater incidence of marked intracerebral oedema around the hard tumours. All hypodense tumours enhanced to greater than brain attenuation; mean enhancement was relatively less in the tumours of high plain scan attenuation regardless of consistency and there was no relationship between degree of enhancement and either the consistency or with the amount of vascularity as estimated by the surgeon or histologist.


Subclinical organic psychosyndromes on intrathecal injection of metrizamide for lumbar myelography.

Eighteen patients with symptoms and signs of possible lumbar disc herniation, who had no evidence of a preexisting organic psychosyndrome were included in the study. An organic psychosyndrome was found in six of them 10 h after lumbar myelography with metrizamide. The psychosyndrome, which was characterized by impaired memory and depression, could be demonstrated only by psychometric methods. In these patients metrizamide could be demonstrated within the basal cisterns by computed tomography 8 h after lumbar injection of the contrast medium. The organic psychosyndrome was completely reversible; five days after myelography it could not be detected any more by psychometric means. The development of an organic psychosyndrome in six of the 18 patients suggests a neurotoxic effect of metrizamide. This assumption is supported by hypo- and areflexia in four patients after intrathecal metrizamide as well as by EEG changes seen in three patients after myelography. There was no correlation between the EEG changes or reflex abnormalities and the organic psychosyndrome.


CT fogging effect with ischemic cerebral infarcts.

Systematic CT studies on ten patients with persistent ischemic cerebral infarct revealed a constant phenomenon, the fogging effect. The hypodense infarct at the beginning will be isodense, or close to isodense, on the plain CT during the seond of third weeks and at a later stage will be hypodense again. The fogging infarcted area shows homogeneous intensive contrast enhancement. Knowledge of the fogging effect is important for correct interpretation of the CT image and the indication for contrast medium CT. CT without contrast medium may lead to misinterpretation during the second and third weeks after the onset of cerebral infarction.


The value of computed tomography in cerebral syphilis.

The computed tomographic findings of three patients with cerebral syphilis, including cerebral gumma, which regressed completely under penicillin therapy, syphilitic angiitis with cerbral infarction, and syphilitic cerebral atrophy, are reported. CT is unable to provide specific diagnostic data for these conditions. The etiology can be clarified only by taking into consideration the clinical findings and course, the serological results, and the result of therapy.


Bilateral reversible thalamic lesions on computed tomography.

Bilateral approximately symmetrical hypodense areas located in the thalamus were encountered in two patients who recovered clinically. Regression of the lesions could be observed on CT. The clinical symptoms corresponded to the thalamic location. Since these two patients recovered, no autopsy material is available to prove the nature of the causative lesion, although the etiology is most probably inflammatory.


Transsphenoidal meningocele with hypothalamic insufficiency.

A 16-year-old girl with transsphenoidal meningocele and signs of hypothalamic insufficiency is presented. Hormonal disturbances have been reported in only three similar cases in the literature. The radiological criteria for the diagnosis are discussed with emphasis on the differential diagnosis of a persistent cranipharyngeal canal. Based on the present case and studies of the pertinent literature we propose that all patients exhibiting signs of dysraphism of the base of the skull should be thoroughly investigated for hormonal disturbances. Children with cleft palate should be examined for possible concomitant dysraphism of the skull.


Bilateral false aneurysms after carotid endarterectomy.

Aneurysms of the extracranial carotid artery are not common. Various etiological factors have been enumerated. A case with bilateral carotid aneurysms following endarterectomy is presented.


Hypervascular cavernous angioma at angiography.

Arteriovenous malformations usually do not present any diagnostic difficulty on the angiograms. However, small cryptic and cavernous angiomas cannot be demonstrated directly by arteriography because of either sluggish circulation or thrombosis. The present communication documents a relatively rare case of histologically proven cavernous angioma with a hypervascular pattern on the arteriogram.


Vertebra plana Calvé.

The differential diagnostic problems of a case of vertebra plana Calvé having a rare location in the cervical spine are discussed. The various theories of aetiology and pathogenesis are considered briefly. The differentiation from inflammatory and tumourous diseases of the vertebral column is of great importance for therapeutic reasons. Skeletal scintigraphy was used for the first time for differential diagnosis in the case presented.


[Preliminary considerations on the behavior of single plasmatic free fatty acids in obese subjects exposed to lipolytic stimulus before and after a period of caloric restriction].

The compositions of the plasma free fatty acid picture changes in relation of the metabolic situation, which is not that theoretically predictable from the adipocyte triglycerides. After a meal, this is due to the existence of a labile storage pool, which derives its features directly from those of the food lipids. In the fasting subject, when this compartment has exhausted its remains, the failure of the NEFA picture to correspond to that of the fats constituting the stabel pool may be attributable to selective release, or to preferential utilisation of each fatty acid. Analysis of the composition performed a very short time after a supramaximal lipolytic stimulus, i.e. when the release of fatty acids surpasses their peripheral removal, by confirming the differences noted under basal conditions, suggests that the first theory used to explain the phenomenon is most likely the correct one.


[Prevention of breast cancer. An initiative launched by the Varese/3 southern outer health consortium (author's transl)].

The results of a breast tumour prevention campaign conducted in 1977-78 by the Varese/3 Southern Outer Health Consortium are described. All women aged 30-65 yr were asked to come for a clinical examination of the breast by suitably trained midwives. Periodic self-examination was explained on this occasion and a card was prepared with historical data for evaluation of the risk factors. 4708 of the 8226 women approached came for examination (57%). Of those subjected to further diagnostic tests, 170 are still under out-patient control, while 34 have been hospitalised with a neoplastic incidence of the order of 1.28%, coupled with a pathological picture with various probabilities of degeneration. On the whole, it is felt that the most useful feature of the venture was its contribution towards the health education of the female population, and its bringing out of risk factors. A favourable judgement is passed on the campaign and its continuation is suggested.


Retrograde demonstration of hippocampal afferents from the interpeduncular and reuniens nuclei.

The origin of hippocampal afferent projections was studied after horseradish peroxidase injections into the hippocampal formation. Labeled cells were found in the dorsal and ventrolateral aspects of the interpeduncular nucleus and in the ipsilateral portion of the nucleus reuniens thalami. In addition, neurons containing HRP were observed in the cortical, hypothalamic and brain stem areas reported by previous investigators.


The posterior pretectal nucleus: evidence for a direct projection to the inferior olive of the cat.

In our horseradish peroxidase (HRP) study of the afferents to the medullary raphe nuclei in the cat, HRP uptake by damaged axons en route to the inferior olive (IO) was thought to be responsible for retrograde labelling of specific midbrain nuclei. To control for such indirect labelling, HRP was injected iontophoretically into the inferior olive. The location of retrogradely labelled neurons was related to the specific locus of HRP injection within the IO. Injection of HRP into the caudal dorsal accessory olive resulted in dense neuronal labelling in the ipsilateral caudal pole of the posterior pretectal nucleus (PPN). There was no labelling of the nucleus of Darkschevitch (Dk), interstitial nucleus of Cajal (ICA) or Edinger-Westphal nucleus (EW). In contrast, an injection focussed more rostrally, into the rostral, dorsal accessory, the medial accessory and the principal olive, produced dense labelling of Dk, ICA and EW; there was much less PPN labelling. It is concluded that labelling of Dk and PPN after HRP injections rostral to the IO, is due, at least in part, to uptake of HRP by damaged medial longitudinal fasciculus axons en route to the inferior olive. The direct PPN-inferior olivary projection provides a potential disynaptic retino-cerebellar connection, which may be involved in rapidly timed eye-body coordinate movements.


Trunk-ocular reflex in the rabbit.

The trunk-ocular reflex of the rabbit was investigated by recording EMGs of right lateral rectus and splenius muscles. The skull and the chest of the rabbit were restrained and the lower part of the trunk was flexed laterally around the axis at the TH10--11 intervertebral joint. Two kinds of eye movements, small with short latencies and large with longer latencies, were induced counter to the direction of the lateral flexion. The latency of the former was 158 msec (range: 64--200 msec) and that of the latter was 255 msec (range: 180--380 msec).


Neurons of the motor cortex projecting commonly on the caudate nucleus and the lower brain stem in the cat.

The cortico-caudate projections due to collateral axons of cortico-spinal and/or cortico-bulbar fibers were explored. In 34 cats, 59 neurons in the motor cortex were extracellularly identified to be antidromically activated by stimulation of the caudate nucleus (Cd). Thirty four neurons responded antidromically only to Cd-stimulation, and they were irresponsive to thalamic stimulation. Contrarily, 25 neurons responded antidromically not only to Cd-stimulation but also to stimulation of the cerebral peduncle and/or the medullary pyramid. 40% of the latter were orthodromically activated by thalamic stimulations. They were considered to be important in coordinating the cerebellum and the basal ganglia system.


LSD's effect on neuron populations in visual cortex gauged by transient responses of extracellular potassium evoked by optical stimuli.

The effects of systemic LSD (10--25 micrograms/kg) on visually evoked [K+]o responses from the striate cortex have been investigated in cats. Elevation of [K+]o was dependent on the orientation, and direction of stimulus movement and showed ocular dominance. LSD most commonly produced a depression of [K+]o transients and a deterioration in their directional selectivity. These observations suggest that the effect of LSD is to produce a net depression in visually evoked neuronal firing.


Pontine afferents to the medullary respiratory system: anatomofunctional correlation.

A direct projection from the parabrachialis medialis, Kölliker-Fuse complex (PMKF) to the bulbar respiratory area is shown using autoradiography. Perikarya of PMKF project to the medulla, labelled fibers and terminals being located radially to the fourth ventricle from the nucleus hypoglossus to the ambiguus. The functional importance of this projection is demonstrated in pharmacological studies using iontophoresis of L-glutamate which enable identification of somatodendritic discharges. A good correlations exists between the localization in the medulla of labelled fibers and terminals and that of an inspiratory background activity related to inspiratory fibers or terminals.


Interhemispheric engram transfer in chick.

Monocular training on a one-trial passive avoidance task in the young chick has been shown to establish an engram in the forebrain hemisphere contralateral to the trained eye, and hence interocular transfer of this task must involve the naive hemisphere making access to the engram in the opposite hemisphere. We have studied the consequences for the untrained hemisphere of accessing a unilateral engram during two short term stages of its consolidation, by conducting interocular transfer tests at 7.5 min and 30 min after learning, prior to onset of amnesia induced by intracranial injection of ouabain or cycloheximide. Testing the naive hemisphere 24 h later indicated that engram transfer had occurred in chicks receiving one access trial at 7.5 min, during the first stage of consolidation of the unilateral engram. At 30 min, during second consolidation stage, five access trials were required to achieve engram transfer. These experiments confirm the findings from the rat that engram transfer can follow from making access to the unilateral engram. However, it has not previously been recognised that interhemispheric memory transfer depends on the recency of formation of the unilateral engram.


Cell kinetic in retinal cell morphogenesis.

The nuclear volumes and the percentage of pycnosis were studied in the various forms of retinal cells as related to the critical stages of morphogenesis. Each cell type was found to have a different mode of nuclear volume increase. The percentage of pycnosis was found to be highest at the stages when the inner and outer segments were established, i.e., a stage when the retinal circuitry was completed.


In vivo incorporation of exogenous [1-14C]stearic acid into neurons and astrocytes.

Exogenous stearic acid is needed to synthesize the membranes of neurons and astrocytes. Subcutaneously injected [1-14C]acid is taken up through the 'blood brain barrier' and incorporated into lipids of both cell types, the specific radioactivity being higher in astrocytes as compared to neurons (2200 and 800 cpm/mg proteins, respectively), 20 h after injection. Phospholipids contain high amount of radioactivity (80% in astrocytes, 65% in neurons); glycosphingolipids contain low quantities of label in the two cell types. The injected acid is partly metabolized in the brain by elongation and desaturation (thus providing very long chains, saturated mono-unsaturated and poly-unsaturated); it is also partly degraded into acetate units (utilized for synthesis of palmitic acid).


Evidence for the occurrence of early modifications in the 'glia limitans' layer of the neocortex of the reeler mutant mouse.

A comparative EM study of the marginal zone of the neocortex in E15 foetuses of normal and 'reeler' mice was carried out. In the mutant a direct contact between 'proneurons' and the superficial basal lamina bordering the 'glia limitans' layer was observed. Since this phenomenon occurs with a much higher frequency in the mutant than in the normal animal, it is thought to be important in the genesis of the 'reeler' anomaly. In the discussion, different hypotheses concerning the possible nature, mechanism and importance of the interaction described are suggested.


Node-like areas of intramembraneous particles in the unensheathed axons of dystrophic mice.

The unensheathed axons in the spinal roots of adult dystrophic mice were examined by freeze-fracture electron microscopy. In most areas of these abnormal fibers the distribution of intramembraneous particles was similar to that of the internodal segments of normal axons with many more particles on the PF (internal) leaflets of these axonal surface membranes than on their EF (external) leaflets. However, patches of axonal membranes were also observed in which the distribution of intramembraneous particles resembled that seen in nodes of Ranvier.


Stress induced grooming in the rat--an endorphin mediated syndrome.

Exposure of adult male Sprague--Dawley rats to a non-traumatic noise-light stress procedure subsequently increased grooming behavior in a novel environment. The grooming syndrome was marginally facilitated by adrenalectomy and by hypophysectomy. Opiate blockade by naltrexone returned grooming to basal levels. This suggests that stress induced grooming is not dependent upon pituitary-adrenal integrity for its expression, although it may be modulated by the latter. On the other hand this form of grooming may depend upon an endogenous opiate system.


Barium ions block the acetylcholine evoked slow H-response in the neurones of Helix pomatia L.

The effects of barium ions on slow acetylcholine (Ach) H receptor activated hyperpolarization has been studied. The results provide evidence of a sensitive and reversible blocking action of Ba2+ on the involved potassium conductance. 3-Aminopyridine (3-AP) also attenuated the slow H-response by 50%, showing partial effectiveness. TEA+ sensitively inhibited the Ach evoked hyperpolarization interacting with the receptors.


Topographical arrangement of hypoglossal motoneurons: an HRP study in the cat.

Myotopical localization of hypoglossal motoneurons and representation of the main branches of the hypoglossal nerve within the hypoglossal nucleus were examined in the cat by the HRP method. The hypoglossal nucleus is divided cytoarchitectonically into the ventromedial and dorsolateral divisions; the medial and lateral branches of the hypoglossal nerve are represented respectively in the ventromedial and dorsolateral divisions. The genioglossus motoneurons are located in the ventrolateral part of the ventromedial division, and the geniohyoid motoneurons are in the most ventral part of the ventromedial division. The hypoglossus and styloglossus motoneurons are located in the lateral and dorsolateral parts of the dorsolateral division.


Electron microscopy of synapses in reptile spinal cord.

The spinal cord of the reptile Anolis carolinensis was examined by electron microscopy. Motor neurons appear as multipolar cells 30-60 micrometer in diameter. Two types of synaptic endings are endings are present on motor neurons. The first type is characterized by distinct synaptic clefts measuring 15-20 nm between pre- and postsynaptic membranes, and by clear presynaptic vesicles. The second type of synapse, which is less common, is characterized by gap junctions between pre- and postsynaptic membranes. At these synapses, there are also clusters of clear vesicles close to the presynaptic membrane adjacent to the gap junction. These findings indicate that both chemical and electrical synaptic transmission are present in the spinal cord of Anolis.


Stress induced Straub tail elevation. Further behavioral evidence in rats for the involvement of endorphins in stress.

Adult male Sprague-Dawley rats briefly immersed in cold water and forced to swim showed Straub tail elevation, a typical sign of opiate stimulation, upon removal. The presence of Straub tail was a function of degree of immersion and was reversed by naloxone. This suggests the Straub tail response may be a novel behavioral index of stress-induced endorphin release.


Effects of periodic saccades on the body sway in human subjects.

The body sway in upright standing was decreased by periodic saccades. The decrease was also observed during voluntary rapid eye movements in complete darkness, indicating that the visual information was not concerned with the decrease of the sway. Continuous eye rotations did not affect the body sway, showing that the repetitive activation of eye muscle proprioceptors was not the cause of the sway reduction. These results suggest that some information related to the execution of saccades may affect the spinal motor system and cause the stabilization of the standing posture.


Development of visual cortical orientation specificity after dark-rearing: role of extraocular proprioception.

Six-week-old dark reared kittens exposed to light for 6 h: (1) with head and body tightly cast into plaster; or (2) free to move around in the animal room. A few days before the visual experience, the ophthalmic branch of the 5th nerve was severed bilaterally in experimental kittens, in order to suppress most of the proprioceptive afferents from extraocular muscles. Electrophysiological analysis of the properties of the receptive fields of visual cortical cells shows that only 6% (group 1) and 11% (group 2) of the cells were selective to orientation as opposed to 67% (group 1) or 32% (group 2) observed in the non-operated kittens.


Thalamic afferents to the visual cortex in congenitally anophthalmic mice.

Retrograde cell labelling with horseradish peroxidase (HRP) has been used to study the thalamic afferents to the primary visual cortex (area 17) in mutant H1-ZRDCT-An ('eyeless') mice, in which the eyes are missing throughout development. Injections of HRP that were localised to a subregion of area 17, resulted in the labelling of a group of neurons in the ipsilateral dorsal lateral geniculate nucleus, showing the existence of a point-to-point connectivity. Many labelled cells were also found in other posterior thalamic nuclei especially in the lateral posterior nucleus which in normal animals contain very few or no labelled cells.


Behavioural stages in memory formation.

Day-old chickens trained in pairs on an aversive discrimination task yielded a retention function with two points of reduced retention, at 15 and 55 min after learning. These points of temporary reduction in retention were interpreted as reflecting change-over of recall from three successive phases in memory formation. Chicks trained in isolation showed the same retention function as paired chicks except that the second point of reduced retention occurred at 70 min after learning. It was suggested that isolation prolonged the availability for recall of the second phase of memory formation. The findings are consistent with and support a three phase, behaviourally sequentially dependent, model of memory formation previously postulated on the basis of pharmacological studies.


Asymmetry of optokinetic trace phenomena induced by unilateral 6-OHDA lesion of substantia nigra in the rabbit.

Prolonged (1 h) optokinetic nystagmus (OKN) is followed in darkness by reversed postoptokinetic nystagmus (RPN) lasting 20-30 min in intact rabbits. Unilateral 6-OHDA lesion (10 microgram/5 microliter) of left substantia nigra did not disturb symmetry of the OKN reactions to monocular stimulation of either eye but weakened RPN induced by stimulation of the right eye. This RPN asymmetry was unaffected by amphetamine (2.5 mg/kg) but was reversed by apomorphine (1 mg/kg). It is concluded that the nigrostriatal system contributes to the development of the neural trace underlying RPN.


The effects of chronic treatment with the 5-hydroxytryptamine uptake blocker zimelidine on central 5-hydroxytryptamine mechanisms. Evidence for the induction of a low affinity binding site for 5-hydroxytryptamine.

Male rats were treated with saline or the 5-hydroxytryptamine (5-HT) uptake inhibitor zimelidine (10 mumol/kg postoperatively) twice daily for a period of 14 days. The effects of this treatment on [5-3H]HT binding in the cerebral cortex and hypothalamus and on 5-HT synthesis were examined. Long-term treatment with zimelidine induced a low affinity site for 5-HT (Kd approximately 20 nM) in both areas and a reduced number of high affinity binding sites in the hypothalamus. Long-term zimelidine treatment did not attenuate the feed-back mediated inhibition of 5-HT synthesis. These findings suggest that chronic zimelidine treatment could result in a reduced activity at postsynaptic 5-HT receptor sites.


Loss of nerve cell bodies in caudal locus coeruleus following treatment of neonates with 6-hydroxydopa.

The locus coeruleus is a well defined nucleus in cresylechtviolet preparations and the perikarya are easily distinguished. The coeruleus neurons are thought to be noradrenergic and during development can be selectively affected by the neurotoxin, 6-hydroxydopa (6-OHDOPA). In 6-month-old rats that were treated on day of birth with 6-OHDOPA (60 mg/kg, i.p.) there was a 32% loss of nerve cell bodies in the locus coeruleus. While it was apparent that loss of cell bodies occurred throughout the entire nucleus, the greatest loss of perikarya was from the caudal extent of the nucleus. It is known that sprouting of noradrenergic terminals occurs in the cerebellum of rats following treatment of newborns with 6-OHDOPA. That there are fewer cell bodies to contribute additional terminals further dramatizes this sprouting phenomenon.


Locus ceruleus somata contain both acetylcholin esterase and norepinephrine: direct histochemical demonstration on the same tissue section.

In the same brain section stained first for catecholamines and then for acetylcholinesterase (EC 3.1.1.7), it was found that neuronal somata in locus ceruleus containing norepinephrine also contained the cholinergic degradative enzyme. Cell body shapes were fusiform, pyramidal, round, or oval. Maximum soma extent ranged from 10--40 micrometers, with the proportion of large diameter neurons increasing, and the smaller diameter cells decreasing, from rostral to caudal cerulear levels. Medium-sized neurons were roughly constant throughout the nucleus. Acetylcholinesterase may be associated with cerulear somata and proximal processes containing norepinephrine to inactivate a cholinergic input to that structure.


Myoinositol turnover in the intact brain of conscious and anesthetized rabbits.

Turnover of myo-inositol in the intact brain of the conscious or anesthetized rabbit was estimated from the rate of appearance of endogenous myo-inositol in the cerebroventricular compartment. The rate of appearance of brain-produced myoinositol was determined by isotope dilution during ventriculo-cisternal perfusion with artificial cerebrospinal fluid containing [14C]myoinositol. Removal of the labelled compound from the perfusate was also determined. A mean value of 5.6 nmol/min was obtained for the rate of appearance of cerebral myoinositol in conscious rabbits. Pentobarbital anesthesia caused a 30% decrease in the rate of appearance of myoinositol in the perfusate without significantly altering its fractional rate of removal.


Origin of the rubrospinal tract of the rat.

The location of cells of origin of the rat rubrospinal tract has been determined by the use of retrograde axonal transport of horseradish peroxidase. Rubral neurons projecting to cervical spinal levels are found in dorsal and medial portions of the nucleus while those sending fibers to lumbar cord levels are located ventrally and ventrolaterally within the nucleus. No cells in the rostral one-half of the nucleus were labelled in this study. The results indicate that the rat rubrospinal tract originates from somatotopically-organized groups of neurons in the caudal one-half of the red nucleus.


Early histogenesis in the mouse cerebral cortex: a Golgi study.

The early histogenesis in the cerebral cortex of the mouse was studied with a modification of the rapid Golgi method. Three stages can be distinguished first, a period during which the telencephalon is exclusively populated with neuroepithelial cells (till E12); secondly the transient stage of the primordial cortical organization, characterized by the presence, in the outer part of the neural tube, of a loose network of primitive horizontal nerve cells and third, the appearance of the early cortical plate (E14) which contains closely packed, radial bipolar nerve cells. In addition to some salient morphological features of the various cell types, the technique also reveals the importance of efferent fibers from the cortex during the early cortical development.


Beta adrenergic stimulant suppression of efferent activity of the adrenal nerve.

Efferent activity was recorded from nerve filaments dissected from the sympathetic nerve branches to the adrenal gland (adrenal nerve). An infusion of isoproterenol into the carotid artery suppressed the discharge of the adrenal nerve as did an equal dose of epinephrine whereas systemic blood pressure descended after isoproterenol injection. The beta blocking agent inhibited the suppression after epinephrine and isoproterenol application. The results suggest the existence of reflex inhibition of adrenal nerve activity through beta adrenergic receptors besides that of baroreceptors.


Ultrastructure of acetylcholinesterase containing striato-nigral neurons transporting HRP retrogradely.

The fine structure of striato-nigral efferent neurons, retrogradely labeled with HRP, was studied. The neuron showed a medium sized ovoid or tri-angular perikaryon. Short or medium lengthened granular endoplasmic reticula, having a tendency to wind and pile up in stacks were observed. This neurons corresponds to a type III neuron according to our classification [4,5]. The neuron showed reaction products, indicating AChE activity, in the granular endoplasmic reticula and plasma membrane.


Endogenous brain angiotensin II disrupts passive avoidance behavior in rats.

The presence of angiotensinogen, the precursor of angiotensin II (ANG II), in brain tissue and in cerebrospinal fluid (CSF) allows stimulation of endogenous brain ANG II by renin. Passive avoidance tests were performed in female Wistar rats. The animals received an electrical shock after entering a black box on the first experimental day. Avoidance was tested every 24 h for 5 consecutive days. Renin in doses of 0.01 and 0.1 units was injected once into the lateral brain ventricles 2 min before the first test. CSF ANG II increased from 40 to 4547 and 5152 fmol per ml (means), respectively. A dose-dependent disruption of avoidance learning was observed, the frequency to enter the black box increasing from 11% (control) to 29% and 46%, and the latency decreasing from 165 (control) to 143 and 116 sec, respectively. These effects were statistically significant (P less than 0.001) for more than 24 h and returned to control levels after 48 to 120 h. Administration of the converting-enzyme inhibitor SQ 14225 i.v.t. prior to renin injections abolished the renin effects. Injections of renin given 22 h after learning were without effect.


A presynaptic action of dopamine on globus pallidus afferents to substantia nigra in the rat.

Dopamine applied iontophoretically onto substantia nigra and adjacent reticular formation units, changed the pattern of response evoked in these cells by stimulation of the globus pallidus. This change was reversible and was sensitive to iontophoretically applied dopamine. It is proposed that this effect is brought about by an interaction of dopamine with dopamine receptors located on afferent fibres coming from the globus pallidus.


Neurite outgrowth elicited by embryonic chick heart: partial purification of the active factor.

Chick heart explants stimulate a dense outgrowth of neurites in co-cultured spinal, sympathetic and ciliary ganglia. A factor sharing these properties was partially purified by gel filtration of extract prepared from lyophilized 18-day embryonic hearts. The active factor has an apparent molecular weight of roughly 40,000 and is evidently distinct from nerve growth factor (NGF) by stimulating the parasympathetic ciliary neurons and by lack of cross-reactivity with antibodies to NGF.


Identification of the superior salivatory nucleus in the cat as studied by the HRP method.

Using horseradish peroxidase (HRP) bathing of either the intermediofacial nerve or the chorda tympani, the localization of the superior salivatory nucleus that gives rise to parasympathetic fibers to the submandibular and sublingual glands was identified in the cat. The superior salivatory nucleus demonstrated by this study does not exist in the pons but does exist in the dorsal part of the reticular formation of the rostral medulla oblongata. Neurons of this nucleus were generally medium-sized and multipolar, with densely stained Nissl substance.


Supraspinal inhibition of spinal neurones responding to nociceptive stimulation.

A study of the tonic descending inhibition present on neurones of laminase IV and V in the lumbar spinal cord of anaesthetized cats has been made employing reversible blocking of the spinal cord by cooling. The results suggest that neurones of both laminase are subject to a similar degree of inhibitory control and imply that they are equally important to the spinal transmission of noxious input.


The effect of morphine applied locally to mesencephalic dopamine cell bodies on spontaneous motor activity in the rat.

The effect of local application of morphine (5 microgram) into the ventral tegmental area (VTA) or substantia nigra, pars compacta (SNc) on spontaneous activity was studied in the rat. Morphine in the VTA but not SNc produced an enhancement of locomotor activity which became progressively augmented with repeated injections. This effect could be blocked by systemic injections of naloxone or haloperidol. It is suggested that stimulation of opiate receptors in the vicinity of dopamine cell bodies can increase the activity of ascending mesencephalic dopamine neurones.


Ortho-antidromic latency fitting and identification of antidromically activated CNS long-axoned neurones.

The intrinsic errors of the collision test were evaluated in extracellular recordings of cat's pyramidal tract (PT)-units. A modified collision technique by means of paired and suitably timed PT-stimuli allowed the demonstration of the ortho-antidromic latency fitting. This method could represent an important counterproof to the true antidromic activation of CNS long-aconed neurons.


On a possible neural mechanism underlying a finding by Evarts and Fromm.

A finding by Evarts and Fromm [1] that the number of unit firings in certain pyramidal-tract neurons is very large for very small, but precise, movements suggests that the mathematical Law of Large Numbers may be operating here. According to this law, under suitable conditions the average of a large number of variables is very precisely defined--its deviation from its ideal value being less the larger the number of variables. Such an algorithm operating in the nervous system might generate precision of muscle control from the frequency of firing of neutrons belonging to a certain neuron system.


A refractory period after brief activation of mammalian skeletal muscle fibres.

A two pulse technique was used to study the decay of mechanical activation in TTX poisoned mouse extensor digitorum longus (EDL) and soleus muscle fibres. A two microelectrode point voltage clamp technique was used with visual endpoint determination of the threshold potential for activation. The excitatory effect of a brief (0.5-2.0 msec) depolarizing pulse decayed quickly and became inhibitory. In EDL fibres the peak inhibition was 0.5-1.0 msec after the termination of the conditioning pulse and decayed within 3.0 msec. Inhibition was less pronounced in soleus fibres and decayed more slowly. It is suggested that inhibition may be responsible for a refractory period in excitation-contraction coupling.


Demonstration of a direct projection from the intralaminar central lateral nucleus to the primary visual cortex.

Orthograde autoradiographic and retrograde horseradish peroxidase (HRP) tracing techniques were used to demonstrate the existence of a direct projection from the central lateral nucleus of the intralaminar complex of the thalamus to the primary visual cortex of the cat. The projection is sparser than the projections from the thalamic non-specific nuclei to other cortical areas of the cat which have been described in the past [9,20,21]. The projection to primary visual cortex is most dense in cortical layers I and VI. It does not appear to have a well-defined topographical organization within this cortical area.


Plasticity in synaptic appositions of optic nerve afferents under different lighting conditions.

The influence of constant light and darkness (14 days) on the ultrastructure of synaptic appositions of optic nerve afferents has been studied in the suprachiasmatic nucleus (SCN) of hooded rats. Light exposure causes a general loss of postsynaptic density (PD) material, whereas after constant darkness the postsynaptic densities are thicker and the number of subjunctional bodies is higher. Accordingly, there are changes in the relative number of 'asymmetrical' (excitatory?) and 'symmetrical' (inhibitory?) synaptic appositions in optic and non-optic synapses. This phenomenon seems to reflect an adaptive response of the postsynaptic neurons to a long-term change of input activity.


Improvement of learned behavior through cholinergic stimulation of the caudate nucleus.

To test the hypothesis that cholinergic activity of the head of the caudate nucleus (CN) is involved in the processes underlying instrumental performance, the effects of microinjections of several doses of choline into this structure on lever pressing behavior were assessed. A dose-dependent modification of performance was found: small doses improve and large doses impair level pressing, while choline applications into the parietal cortex were without effect. The facilitatory effects were reproduced by microinjections of acetylcholine into the CN. These data further support our working hypothesis.


Effect of hypophysectomy on alpha-melanotropin in discrete regions of the rat brain.

The effect of hypophysectomy on alpha-melanotropin (alpha MSH) concentrations in discrete brain regions was investigated. Hypophysectomy resulted in a 38-69% decrease in alpha MSH concentration in alpha MSH terminal regions 4 weeks after surgery. In contrast, the alpha MSH concentration in the arcuate nucleus, site of alpha MSH containing perikary, was unaffected by hypophysectomy. These results indicate that the brain alpha MSH system is distinct from, but related to that of the pituitary.


Is clonidine an adenosine antagonist?

Clonidine has been reported to possess the ability to block the depressant actions of purine compounds on the firing of rat cerebral cortical neurons. In studies on rats anaesthetized either with nitrous oxide and methoxyflurane or urethane, it was not possible to confirm this observation. Rather clonidine enhanced the depressant actions of iontophoretically applied adenosine and adenosine 5'-monophosphate (5'-AMP).


Oxygen consumption of rat tissue slices exposed to methylmercury in vitro.

The physiological significance of damage from methylmercury exposure was assessed by comparing the oxygen consumption of rat liver, kidney and brain tissue slices after direct exposure to methylmercury chloride. Standard Warburg respirometers were used. Methylmercury chloride was added during the preparation of the experimental flasks and the tissues were preincubated for up to one hour. Oxygen consumption was accelerated by tipping sodium succinate into the main chamber from the sidearm. During the ensuing 3 h of observation, oxygen was consumed at a uniform rate and all the organ slices were equally inhibited at the respective concentrations of methyl-mercury tested. Brain slices without excess succinate were slightly more sensitive to the presence of methylmercury, but this difference was significant only at 2 . 10(-4) M methylmercury. The results suggest (a) that all three organs are about equally sensitive to direct toxic insult by methylmercury under standardized conditions, (b) that any difference observed is due to metabolic reserve capacity and (c) that organ damage induced by methylmercury cannot be attributed to a direct interference with the glycolytic machinery of the cells since organ tissue levels at the point of intoxication are considerably lower.


Locomotion in the decerebrate stingray.

Stingrays swim with an active elevation-depression sequence of the pectoral fin resembling an extension-flexion sequence. During forward locomotion this sequence passes caudally along the pectoral fin. Immediately following high decerebration, stingrays are capable of locomotion, and the pattern of muscle activity closely resembles that of intact animals. Spontaneous and midbrain evoked rhythmic motoneuron discharges can be recorded in paralyzed decerebrated animals. In contrast to dogfish sharks, stringrays with high spinal transections do not locomote.


Inhibition of aminotransferase enzyme systems by gabaculine.

Addition of gabaculine to brain and liver extracts caused great inhibition of GABA-T activity, a much lesser but still significant inhibition of ALA-T activity, and very little inhibition of ASP-T activity. In contrast, intramuscular administration of gabaculine to mice resulted in considerable inhibition of all three enzyme activities in liver, the order of sensitivity being ALA-T greater than GABA-T greater than ASP-T. The effect of the administered gabaculine on the brain enzyme activities was more along the lines seen in the in vitro experiments but, even here, the relative sensitivities of GABA-T and ALA-T to the inhibition were much more similar than might have been predicted from the in vitro experiments.


Disappearance and recovery of catecholamine innervation in brain regions of adult goldfish following 6-hydroxydopamine treatment.

The effect of 6-OHDA treatment on catecholamine innervation was studied in the cerebellum, optic tectum and lobus vagi of the goldfish. Catecholamine terminals completely disappeared in less than two weeks after intraventricular injection of 10 microgram 6-OHDA. In periods comprised between 40 days and 4 months after drug injection, catecholamine terminals reappeared to a different degree. The cerebellum showed the highest recovery and, as far as the valvula cerebelli was concerned, also over-innervation. The remarkable power to restore catecholamine innervation led to a distribution of reappearing terminals similar to that of normal animals in the different layers of the three structures examined.


Lophozozymus pictor toxin: a potent inhibitor of synaptosomal GABA uptake.

A partially purified toxin obtained from the coral reef crab, Lophozozymus pictor was found to be a potent inhibitor of Na+-dependent [14C]-GABA uptake by rat brain synaptosomes. Inhibition was potentiated in the presence of external K+. The I50 value for the toxin was found to be in the region of 10 microgram/ml at a GABA concentration of 2 microM. The inhibition showed substrate competition.


Serum and mucopolysaccharide (glycosaminoglycans) levels in psychiatric patients.

Serum acid glycosaminoglycans (GAG) levels were measured in 50 normals and 177 samples from different types of psychiatric patients. Mean levels were significantly higher in paranoid type schizophrenia, organic brain syndrome associated psychosis and manic type manic-depressive psychosis. The levels returned to slightly above the normal range upon partial remission in paranoid schizophrenics. In catatonic and hebephrenic schizophrenias the values were in the upper part of normal range. The levels were either in upper normal range or slightly higher in non-psychotic organic brain syndrome. In depressed type manic depressive psychosis levels were either lower than normal or in the lower part of normal range.


The influence of calcium on short-term memory.

Using a passive avoidance behavioural task in day-old chickens, it is possible by intracranial injection of appropriate drugs to separate out three phases of memory formation. The duration of the first such phase, called short-term memory, is increased when the intracranial calcium ion concentration is raised and the phase is practically abolished by injection of lanthanum ions.


Axonal microtubules: their regulation by the electrical activity of the nerve.

The effect of nerve impulses upon the axonal microtubules was studied in the sural nerve of the cat. We showed that a sustained activity (40 impulses/sec for 2 h) determines a difference in microtubule counts: the active nerve exhibited 24% more profiles than the resting one. In addition, microtubules of the active nerve appear to be less sensitive to the depolymerizing action of colchicine. We propose that the action potential leads to a decrease of the disassembly rate constant of microtubules.


Encoding of graded noxious skin heating by neurons in posterior thalamus and adjacent areas in the cat.

Impulse discharges were recorded from 62 single units in the posterior thalamic and adjacent nuclei of the cat which received input from hindlimb cutaneous nerves. Noxious radiant heating (e.g., 50 degrees C for 10 sec) of the hindpaw excited 32% of the units. The magnitude of heat-evoked unit discharges was graded with the intensity of noxious heating. Such units had large cutaneous receptive fields spanning 2 or more limbs, and responded to strong mechanical stimuli (pressure, pinch). About half of the units responded also to light stimuli such as hair bending or touch.


High resolution radioautographic identification of [3H]GABA labeled neurons in the rat nucleus raphe dorsalis.

Following intraventricular administration of [3H]GABA into the lateral ventricle of the rat radioautography demonstrates the presence of labeled cell bodies and fibers within the nucleus raphe dorsalis (NRD). Pharmacological controls suggest that labeled perikarya whose diameter does not exceed 10 micrometer and which are not probably more than ten in the entire NRD could be GABAergic. The effects of 5,7-dihydroxytryptamine (5,7-DHT) pretreatment support the hypothesis  that labeled fibers could belong at least to two populations: ones being probably serotonergic and the others being possibly GABAergic. These results are in good agreement with the existence of an intrinsic GABAergic system within the rat NRD.


The cerebellar projection from the paratrigeminal nucleus in the cat.

The cerebellar afferent projection from the paratrigeminal nucleus (PTN) was studied in the cat by means of retrograde axonal transport of horseradish perioxidase (HRP). Most of the afferent fibres reach the cerebellar lobules I, II, V (hemispheral part), VIIIB and IX, the paramedian lobule and the fastigial nucleus. The total distribution of the cerebellar afferents is shown in Fig. 2. The findings extend Chan-Palay's [2,3] recent studies on the cytology, synaptic organization and neurotransmitter content of the paratrigeminal nucleus in monkey and rat.


Afferent connections of the laterodorsal thalamic nucleus in the rat.

The laterodorsal thalamic afferent connections have been studied by means of the retrograde transport of horseradish peroxidase (HRP). The following new sources of projections to the laterodorsal thalamic nucleus (LD) were observed: the zona incerta, the lateral dorsal tegmental nucleus (bilaterally), the lateral hypothalamus and the precentral agranular cortex.