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Biomedical subjects

C Clark

Publications and source records attributed to C Clark.

At least 271 records · Page 15Linked to original sources
PubMed1978

Synthetic substrate beta-glucosidase activity in leukocytes: a reproducible method for the identification of patients and carriers of Gaucher's disease.

A method is described for the identification of patients and carriers of Gaucher's disease, using leukocytes from a small volume of blood. The fluorogenic substrate, 4-methylumbelliferyl-beta-D-glucopyranoside, was assayed in the presence of pure sodium taurocholate (2.5 mg/ml) and Triton X-100 (2.0 mg/ml). Some commercial brands of pure sodium taurocholate were satisfactory for this purpose. The pH optimum for controls, Gaucher disease carriers and Gaucher disease patients was 5.4 using citrate-phosphate buffer. Although leukocytes prepared from only a small amount of blood (2-8 ml) are required, there is sufficient quantity for measuring other lysosomal enzymes as controls. Using this method, 12 patients with all types of Gaucher's disease and 12 obligate heterozygotes were identified. Carrier status was predicted in six other family members and ruled out in six others. Eight unaffected people married to Gaucher carriers or Gaucher patients were predicted to be non-carriers of Gaucher's disease, thereby ruling out children affected with Gaucher's disease in that mating.

Adult↗
PubMed1978

Suppression of prolactin by dopamine agonists in schizophrenics and controls.

Prolactin levels were determined in plasma samples obtained before and after administration of apomorphine or L-dopa to otherwise unmedicated chronic schizophrenic patients or control subjects. Basal prolactin levels did not differ in these two groups. Suppression of prolactin levels after each dopamine agonist was highly significant. Suppression in schizophrenics was slightly less than in controls following apomorphine and slightly greater following L-dopa. The authors discuss the implications of these findings as well as the limitations of the prolactin regulatory system as an index of dopamine agonist sensitivity.

Adult↗
PubMed1978

Cerebral cysticercosis.

Five patients with cerebral cysticercosis, two within the year preceding the date of this article, were seen at the New York Neurological Institute. The patients presented with mental changes, seizures, and symptoms of increased intracranial pressure, and had a history of having immigrated from an area endemic for cysticercosis. They were found to have parenchymal or intraventricular cysticercosis cysts. The interval from immigration to onset of symptoms was as long as 3 years. Plain radiograms of the skull and soft tissues, ventriculograms, and especially the CT scan, as well as the CSF examination, were useful in making the diagnosis. Surgical removal of an intraventricular cyst was curative in two patients and seizures were controlled with anticonvulsants in the other three.

Adult↗
PubMed1978

Genetic control of tolerance induction to human gamma-globulin in mice.

Susceptibility to tolerance induction with monomeric human gamma-globulin (HGG) was tested in different inbred strains of mice. The results indicated a differential tolerance susceptibility among the strains and that the basis for the variation is genetic in nature. By using a protocol that permits genetic analysis, F1, F2, and backcross generations of the parental strains SJL/J and C3H/Bi were examined. A multigenic control model by H-2-linked and non-H-2-linked genes showing Mendelian autosomal inheritance is proposed.

Animals↗
PubMed1977

Comparison of two techniques for the quantitative measurement of acid phosphatase in normal and regenerating epithelium of the female hairless hamster.

Two methods have been employed for measuring acid phosphatase activity in normal and regenerating epithelium of the female hairless hamster. The first method entails histochemical preparation followed by television scanning microdensitometric measurements using a Quantimet 72OD. The second method involves incubation of freeze-dried epidermis in a suitable substrate medium followed by measurement of the fluorescence of the released product by a spectrophotofluorometer. The results were compared against each other by performing best-fit polynomial regression line analysis to the data produced by both methods. A correlation coefficient of 0.99 was obtained when interpolated data from the two 'best-fit' curves were compared with each other. This indicates that the histochemical technique and the subsequent measurement using television scanning microdensitometry is 'quantitative' and can, therefore, be employed in quantitative histochemistry.

Acid Phosphatase↗
PubMed1977

The effect of various treatments on the size of sebaceous glands of hairless mice and hairless hamsters.

The effect of castration on the size of sebaceous glands of male hairless mice and male hairless hamsters was studied over a period of 4 weeks. Statistically significant decreases in the size of sebaceous glands were observed. The effects of intracutaneous injections of micronized crystalline suspensions of testosterone, testosterone propionate, testosterone phenylpropionate, testosterone decanoate and nandrolone phenylpropionate on the sebaceous glands of castrated hairless mice, castrated hairless hamsters and intact female hairless hamsters were studied over a period of one week. Highly significant increases in sebaceous gland volume were observed 6-7 days after treatment. The effects of subcutaneous and intracutaneous injections of micronized crystalline suspensions of testosterone on the sebaceous glands of intact male and female hairless hamsters were examined at sites local and distal to the injection. Increases in sebaceous gland volume were limited to local sites in the male but increases were observed locally and distally in the female. There was no difference between subcutaneous and intracutaneous injections.

Animals↗
PubMed1977

Senile dementia: treatment with deanol.

Recent research indicates a possible cholinergic involvement in memory processes and thus the possibility that acetylcholine deficiency may underlie memory impairment in senile dementia. Deanol (2-dimethylaminoethanol), which is assumed to increase brain acetylcholine, was given openly for 4 weeks to 14 senile outpatients, to determine the safety of the drug and whether or not it reduces cognitive impairment. The dosage was gradually increased to 600 mg three times daily during the first two weeks, with no adverse effects. Ten patients improved globally and 4 were unchanged (p less than .01). The total score on the Sandoz Clinical Assessment-Geriatric (SCAG) was lowered by the third week (p less than .01), primarily as a result of reduced depression, irritability and anxiety, and increased motivation-initiative. However, neither the clinical ratings nor an extensive pre- versus post-treatment series of cognitive tests revealed changes in memory or other cognitive functions. Since a similar separate study with a different compound produced no behavioral changes, it is unlikely that the improvement with deanol was due entirely to placebo effects. The results thus suggest that although deanol may not improve memory, it may produce positive behavioral changes in some senile patients.

Aged↗
PubMed1977

Head injuries in children: a prospective five year follow-up.

A five year follow-up study was conducted with two groups of head-injuried children. 131 younger than 9 years old at time of injury and 100 older than 9 years. The four aspects studied were neuropsychological function, neurological status, EEG status, and school progress. There was an extended recovery process over time, as well as evidence of a differential rate of recovery for the four aspects measured.

Adolescent↗
PubMed1977

Comparison of murine delayed hypersensitivity reactions elicited with particle-associated versus soluble human gamma-globulin.

Footpad reactions elicited in DHS mice using human gamma-globulin (HGG)-coated polystyrene latex particles and soluble HGG (sHGG) were compared. Both the magnitude and the persistence of DHS lesions produced by HGG-latex were considerably greater; at 24, 48 and 72 h after challenge, the level of reactivity induced by HGG-latex was 24, 41 and 71% higher, respectively, than those elicited with sHGG. Early nonspecific swelling following injection of HGG-latex in footpads of normal mice was negligible by 24 h, whereas Arthus-responsive animals did not return to control levels until 48 h. The possible advantages and limitations of using particle-associated protein to elicit DHS reactions are discussed.

Animals↗