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Biomedical subjects

C Roy

Publications and source records attributed to C Roy.

At least 253 records · Page 14Linked to original sources
PubMed1983

The Tay-Sachs disease gene in North American Jewish populations: geographic variations and origin.

From data collected in a North American Tay-Sachs disease (TSD) heterozygote screening program, the TSD carrier frequency among 46,304 Jewish individuals was found to be .0324 (1 in 31 individuals). This frequency is consistent with earlier estimates based on TSD incidence data. TSD carrier frequencies were then examined by single country and single region of origin in 28,029 Jews within this sample for whom such data were available for analysis. Jews with Polish and/or Russian ancestry constituted 88% of this sample and had a TSD carrier frequency of .0327. No TSD carriers were observed among the 166 Jews of Near Eastern origins. Relative to Jews of Polish and Russian origins, there was at least a twofold increase in the TSD carrier frequency in Jews of Austrian, Hungarian, and Czechoslovakian origins (P less than .005). These findings suggest that the TSD gene proliferated among the antecedents of modern Ashkenazi Jewry after the Second Diaspora (70 A.D.) and before their major migrations to regions of Poland and Russia (before 1100 A.D.).

Female↗
PubMed1983

[Joubert's syndrome. Apropos of 5 cases].

Five cases of Joubert syndrome in 2 consanguineous sibships are reported. The characteristic polypnea and respiratory pauses were recorded polygraphically during both active and quiet sleep in 2 infants and only in active sleep in another one. Tapetoretinal degeneration was found in both sibships and a chorioretinal coloboma in the 2 affected infants of the second family. The CT scan images in the syndrome and its differential diagnosis are discussed.

Cerebellar Ataxia↗
PubMed1983

[Cortical fissures in Paget's disease].

Cortical bone fissures in Paget's disease develop on the convex surfaces of the femur or tibia. They may be present in large numbers, but this is not related to the degree of diaphysial curvature. The presenting symptom is pain. The course is usually towards recovery though a total fracture may rarely occur. Degeneration is never observed.

Aged↗
PubMed1983

[Acute pseudotumoral demyelination with regressive attacks].

A 14 year-old boy presented, at a 3 month interval, with 2 episodes of hemiplegia of rapid onset. The first time, CT scan revealed a large parietal "tumor", shown to be pseudocystic at surgery, and histologically proven as a demyelinating disease. During the second attack, CT scan showed a similar but contralateral lesion, regressing completely under steroid treatment. 40 months after the onset of the disease, the child's life and intelligence are normal.

Acute Disease↗
PubMed1982

[Congenital candidiasis of the skin (author's transl)].

A typical case of congenital candidiasis of the skin is reported. In these babies the eruption, already widespread at birth, is initially macular to become papulo-pustular, then dries up with desquamation of the skin. The finding of Candida albicans in the amniotic fluid and in placental smears confirms that the infection was present before birth. The condition regresses after local treatment and oral nystatin, but the need for parenteral treatment is controverted.

Candidiasis↗
PubMed1982

[Pseudohypoaldosteronism: familial forms. Eight case-reports, with a review of the literature (author's transl)].

Pseudohypoaldosteronism (PHA) is an uncommon cause of the renal salt loosing syndrome in infancy. The authors describe eight cases in two different families. Hyperaldosteronism persists long after clinical recovery has occurred. Plasma hormone assay allows retrospective recognition of cases overlooked during infancy. This underlines the variability of disease expression among different members of the same family. The high family occurrence rate (over 50%), which is often underestimated, is demonstrated by the study of both families and by a review of published cases. Clinical and biochemical features of familial PHA are discussed. Inheritance is usually on an autosomal dominant basis. However, the small number of reported cases cannot allow any attempt to individualize subgroups of the disorder upon genetic grounds.

Adult↗
PubMed1982

[Electromyography in children with polymyositis (author's transl)].

Findings of repeat electromyography (EMG) in 15 children with polymyositis or dermatomyositis are reported. The data classically provided by EMG in these conditions is recalled. Emphasis is put on the contribution of stimulodetection to the diagnosis of primary disease of the muscle. With this procedure, EMG showed myogenic signs in all patients, at the first examination. Electrical anomalies are widespread from the start. A long-term study in 12 patients shows that electrical anomalies remain present long after clinical recovery. EMG disturbances are the last anomalies to disappear. EMG returns to normal when recovery is longstanding. EMG signs reappear if relapse occurs.

Adolescent↗
PubMed1982

Complementary activity of mezlocillin and the combination of amoxicillin with clavulanic acid on Enterobacteriaceae.

The MICs of amoxicillin, mezlocillin and BRL 25,000, a combination of two parts amoxicillin and one part clavulanic acid (2AM + 1CA), were measured for 331 Enterobacteriaceae strains which produced beta-lactamases as demonstrated by nitrocefin. The MIC values for mezlocillin and the combination 2AM + 1CA were very similar for the total number of the strains investigated. When investigated separately according to the bacterial species, three different sensitivity groups were established for the above-mentioned preparations: 1) species with the same or similar sensitivity to mezlocillin and 2AM + 1CA (Escherichia coli and Shigella spp., amoxicillin-resistant strains); 2) species which were more sensitive to mezlocillin than to the combination 2AM + 1CA (Citrobacter spp., Enterobacter cloacae, Serratia spp. and indole-positive Proteus as well as strains of E. coli and Shigella spp. which produce a cephalosporinase and are sensitive to amoxicillin); 3) species which are more sensitive to 2AM + 1CA than to mezlocillin (amoxicillin-resistant Salmonella spp., Proteus mirabilis and Klebsiella pneumoniae). This complementary activity of mezlocillin and 2AM + 1CA against Enterobacteriaceae depended on the beta-lactamases produced.

Amoxicillin↗
PubMed1982

Structural comparison of the lectin from sainfoin (Onobrychis viciifolia) with concanavalin A and other D-mannose specific lectins.

The D-mannose specific lectin from sainfoin was prepared by affinity chromatography on Sephadex G-75, and its circular dichroism (CD), metal content, antigenic character, and N-terminal amino acid sequence were compared with those of four lectins from Vicieae plants and concanavalin A. The sainfoin lectin was only slightly more closely related to these other D-mannose specific lectins, than to lectins of leguminous plants in general. The CD and antigenic experiments also confirmed the close relationship of the four Vicieae lectins. The N-terminal sequence showed sainfoin has two isolectins, differing in sequence at residue four. The sequence was homologous to N-terminal sequences of several other lectins; hence, despite some structural and specificity similarities, the sainfoin lectin does not show the circular permutation of sequence unique to concanavalin A. This region also contained the sole cysteine residue, at position 33. The carbohydrate-binding properties of the sainfoin lectin were studied by gradient affinity chromatography. Its apparent Ka for methyl alpha-D-glucoside was approximately 10(3) M-1, close to the Ka of the pea lectin. However, in the relative binding behaviour of methyl alpha-D-mannoside, maltose, and methyl alpha-D-glucoside, it resembled concanavalin A more than the pea lectin.

Amino Acid Sequence↗
PubMed1981

[Cefsulodin, a new antibiotic of the group of cephalosporins: its action on Pseudomonas aeruginosa (author's transl)].

Cefsulodin is a new second generation cephalosporin with a narrow antibacterial spectrum. Its main use is in the treatment of Pseudomonas aeruginosa infections. It is resistant to the action of the beta-lactamases of gram negative bacilli, especially to that of the cephalosporinases. We have studied 170 strains of P. aeruginosa and 10 of other species of Pseudomonas, determining the MIC by the serial dilution test in solid medium and the sensitivity by the agar diffusion test. With 8 microgram/ml, a concentration which is accepted as a limit of sensitivity from the therapeutic point of view, 90% of the P. aeruginosa strains studied are inhibited; the MIC50 is obtained with 2 microgram/ml. Within the strains considered sensitive (MIC less than 8 microgram/ml) there is a marked dispersion of the zone diameters corresponding to each of the values of MIC. This behavior limits the value of the regression line. We have also studied the MIC of carbenicillin for nearly all the strains and we have also studied the MIC of carbenicillin for nearly all the strains and we have found that 86.58% are sensitive to both preparations, 4.96% are sensitive to cefsulodin and resistant to carbenicillin, 4.02% resistant to cefsulodin and sensitive to carbenicillin and 4.69% are resistant to both preparations. From the clinical point of view the number of strains sensitive (or resistant) is similar with both substances but cefsulodin is in absolute values from 8 to 128 times more day active than carbenicillin. Cefsulodin is administered by a parenteral route and is eliminated by the urine in active form. The recommended therapeutic dose for the treatment of systemic infections is 2 g daily IV. This dose may be increased if it is considered advisable. There is good local tolerance (IM and IV), it is only slightly toxic, hardly alters the intestinal flora and may be used at all ages, in patients with immunological alterations and in patients with an altered renal function.

Carbenicillin↗
PubMed1981

Relationship of (8-lysine) vasopressin receptor transition to receptor functional properties in a pig kidney cell line (LLC-PK1).

In intact LLC-PK1 cells, occupancy of vasopressin receptors (Roy, C., and Ausiello, D. A. (1981) J. Biol. Chem. 256, 3415-3522) correlated with cell cAMP production. This relationship was observed as a function of hormone dose, incubation time, and changes in receptor affinity. However, the rate of cAMP production diminished with time in intact cells exposed to high hormone concentrations, even in the presence of a phosphodiesterase inhibitor. A rapid desensitization of adenylate cyclase activity was observed in minutes upon treatment of intact cells with high hormonal concentrations. Desensitization was dose- and time-dependent. Hypertonic sodium chloride, which increased hormonal binding and cell cAMP production, prevented desensitization. The acute decrease in hormone-stimulated adenylate cyclase activity correlated with increased occupancy of low affinity binding sites. EDTA-suspended cells, which have a homogeneous population of binding sites, did not demonstrate desensitization. A proposal is made as to the consequences of this phenomenon at physiological concentrations of vasopressin.

1-Methyl-3-isobutylxanthine↗