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Biomedical subjects

R Cohn

Publications and source records attributed to R Cohn.

At least 37 records · Page 2Linked to original sources
PubMed1979

Biotin-response organicaciduria. Multiple carboxylase defects and complementation studies with propionicacidemia in cultured fibroblasts.

Fibroblast cultures from two individuals with biotin-responsive organicacidemia were found to have a pleiotropic deficiency of propionyl-CoA carboxylase, beta-methylcrotonyl-CoA carboxylase, and pyruvate carboxylase activities after growth in biotin limited culture medium, conditions which do not affect the carboxylase activities of normal cells. All three enzyme activities were restored to normal levels after transferring the mutant strains to biotin-rich medium. Both patients excreted abnormal levels of an array of metabolic intermediates, including beta-methylcrotonate, beta-hydroxyisovalerate, beta-hydroxypropionate, and lactate, which reflect metabolic blocks at all three carboxylase sites.14 mutants deficient in only propionyl-CoA carboxylase activity from patients with propionicacidemia and the two biotin-responsive strains were examined for complementation with seven previously mapped pcc mutants. No new pcc complementation groups were identified. Nine of the mutants were mapped to group pccA. The remaining 12 mutants mapped to pccBC or its B or C subgroups, confirming the complex nature of this group. The biotin-responsive mutants failed to complement each other but did complement mutants from all the pcc groups. Thus biotin-responsive organicacidemia is defined by a new complementation group, bio. The results obtained in this study suggest that the bio mutants have a defect of either biotin transport or a common holocarboxylase synthetase required for the biotin activation of all three mitochondrial carboxylases.

Acidosis↗
PubMed1977

Artistic production in dyslectic children.

In the study of children with language problems, particularly in reading and writing, it has been observed that some have an outstanding ability to produce artistic pictures and objects. These productions are perceptive, well organized and generally contain much action. Despite their pictorial skill these patients may have only a rudimentary use of coded symbolic graphic forms. Others display moderate ability in reading and writing. These patients frequently have the disorganized overacctive behavior and the motor clumsiness that is so common in the dyslectic child; some, however, are biologically effective. From this material we entertain the hypothesis that picture (artistic) productions are generated by the sub-dominant cerebral hemisphere, and that this function is quite distinct from the coded graphic operations resident in the dominant hemisphere. If this hypothesis is correct, it would seem socially benefical to allow these patients to develop their unique artistic ability to its full capacity, and not to overemphasize the correction of the disturbed coded symbol operations in remedial training.

Adolescent↗
PubMed1976

Beta-methylcrotonic aciduria associated with lactic acidosis.

A patient is described in whom lactic acidosis of very severe degree was found to coincide with the presence of beta-methylcrotonic acid and rho-hydroxyphenyllactic acid in urine in large amounts, while beta-hydroxyisovaleric acid was found to be a relatively minor excretion product. Beta-methylcrotonic acid is demonstrated, for the first time, to be present in blood and CSF. These findings are discussed in relation to the patients previously reported to have beta-methylcrotonylglycinuria and raise the possibility that our patient's organic aciduria may be secondary to acquired disease rather than to an inborn error of metabolism.

Amino Acids↗
PubMed1974

Forty-day fever. An epidemic of cytomegalovirus disease in a renal transplant population.

An epidemic of cytomegalovirus disease (CMV) occurred in 38 percent of 34 renal transplant recipients during an 18-month period. A characteristic clinical pattern was noted: 40 days following transplantation, daily fevers recurred for periods of four to six weeks. This fever in conjunction with a diffuse interstitial pneumonitis and impaired hepatic and renal function constituted a diagnostic tetrad. Of all the laboratory techniques, throat and urine cultures were the most consistent in confirming the diagnosis. Analysis of the epidemic implicated the communal hemodialysis unit as the source of exposure to the virus. CMV was not seen in the first 86 patients who received transplants in the program, but with increasing use of hemodialysis, the percentage of patients with positive serologic reaction for CMV increased dramatically.

Adolescent↗