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Biomedical subjects

J Cohn

Publications and source records attributed to J Cohn.

At least 73 records · Page 4Linked to original sources
PubMed1979

Glucose-6-phosphate dehydrogenase deficiency in a native Danish family. A new variant.

Deficiency of red cell glucose-6-phosphate dehydrogenase was found in a native Danish family, in which 2 boys suffered from severe haemolytic anaemia. The mother and 3 sisters of the boys were heterozygotes for G-6-PD deficiency. The biochemical investigations indicate that this deficient G-6-PD is very similar to the Mediterranean variant; however, this variant gene may represent another example of G-6-PD 'Helsinki' or an unique variant with properties similar to G-6-PD B(--).

Adult↗
PubMed1977

Bile pigment formation by skin heme oxygenase: studies on the response of the enzyme to heme compounds and tissue injury.

Skin heme oxygenase is locally elevated by stimuli such as tissue injury and injections of whole blood, myoglobin, and hematin. The enzyme activity is also increased at the proximity of the injection site of chemicals such as cobalt and cobalt-protoporphyrin-IX (cobalt-heme). Protoporphyrin-IX, the tetrapyrrole nucleus of type-b heme compounds, was ineffective in altering the enzyme activity in vivo. The developmental pattern of heme oxygenase in skin was compared to that of the enzyme in liver. The enzyme activity in both organs was greatest during the 1st postpartum wk and declined to adult levels after 2 wk. The physiological implications of the increased activity of skin heme oxygenase are discussed, and it is concluded that the activity of the hepatic heme oxygenase system and that of the skin are regulated by the same mechanism.

Animals↗
PubMed1977

Congenital hypomegakaryocytic thrombocytopenia associated with bilateral absence of the radius - the TAR syndrome.

A case of the TAR syndrome is described which presented bilateral absence of the radius and pronounced thrombocytopenia at birth; when seen at the age of 6, growth and development was within normal limits, except for the upper extremities, and no signs of an haemorrhagic diathesis were seen. A careful family study brought 2 additional cases to light: a female second cousin was found to have bilateral absent radius, but no haematological abnormalities when seen at the age of 10. Her younger brother had died at the age of 3 months with severe thrombocytopenia and heavily malformed, flipper-like upper extremities. The broad clinical variation of the syndrome should be kept in mind in genetic studies and counselling.

Abnormalities, Multiple↗
PubMed1977

Hepatitis, type B in haemophiliacs. Relation to the source of clotting factor concentrates.

36 children aged 3 to 18 years receiving substitution therapy for haemophilia during the period 1970 to 1976 were studied for infection with hepatitis B virus by assays for HBsAg, anti-HBs, and anti-HBc. Clinical hepatitis B occurred in 3 patients (8%) and serological evidence of infection was found in further 13 (36%). The occurrence of infection was associated with age but less so with the total amount of transfusion. Estimates of the risk of infection by clotting factor material of different origin indicated a figure of 1:53,000 I.U. for Danish volunteer donor preparations as well as for commercial products, the risk being apparently increased following the use of pooled blood donor material and non-Scandinavian products respectively.

Adolescent↗
PubMed1976

Transmission of hepatitis type B from healthy HBsAg-positive mothers.

Seventeen mothers, all apparently healthy carriers of hepatitis-B surface antigen (HBsAg) during pregnancy, and their children were studied for four to five years to determine the transmission rate of hepatitis-B virus infection. All the mothers had antibody against hepatitis-B core antigen in addition to HBsAg. One of them, a renal transplant recipient, was persistently positive for hepatitis-B-associated e antigen (HBeAg), while the remaining 16, who were detected during screening of healthy pregnant women were positive for anti-HBe. Evidence of infection was found in the child and husband of the woman positive for HBeAg, while none of the 29 children and five husbands of the anti-HBe-positive women became infected.

Antibodies, Viral↗
PubMed1976

Foamy histiocytosis of the spleen in patients with chronic thrombocytopenia.

In 17 of the 64 spleens removed from patients with chronic thrombocytopenia lipid-laden histiocytotes were demonstrated. No correlation was found between these pathological findings and the age of the patients at diagnosis or splenectomy, the duration before splenectomy of therapy with glucocorticoids, the period with thrombocytopenia or the platelet count. 7 of the patients, who relapsed after splenectomy had lipid-laden histiocytes in their spleens i.e. 58% of the patients with relapse, compared with 10 patients with foamy histiocytosis and without relapse i.e. 19% of the patients without relapse. At follow up, 3 of the 17 patients with splenic histiocytosis still had thrombocytopenia, compared with 1 of the 47 patients without foamy cells. Foamy histiocytosis of the spleen from a patient with chronic thrombocytopenia may indicate a dubious prognosis.

Child↗
PubMed1976

Thrombocytopenia in childhood: an evaluation of 433 patients.

An evaluation of 433 children with thrombocytopenia is presented. The material comprises all cases diagnosed in Denmark during the period 1959-1969. The incidence was found to be 31.9 cases per 1,000,000 inhabitants less than or equal to 15 years of age per annum with a peak at the age of 3 to 4 years; the majority of the cases was diagnosed in the spring. Preceding infection, usually associated with fever and localized in the upper respiratory tract, was the most common cause. The majority of the congenital cases was hereditary and associated with other malformations involving in particular the immune system. In about half of the cases the course was spontaneous and no treatment was necessary; the remaining patients were treated with glucocorticoids, including 46 patients, who had undergone splenectomy. 22 patients died, including 16 cases due to serious underlying disorders; in 6 cases the cause of death was haemorrhage (mortality rat=1.4%). At the follow up the platelet count was below 50 mia/1 in 14 patients (4%). No difference was found concerning the platelet count at the follow up between the patients with spontaneous recovery, the patients treated with glucocorticoids and the patients, in whom splenectomy had been performed. During the course the disease autoimmune haemolytic anaemia occurred in 2 patients, whereas no patient developed systemic lupus erythematosus.

Adolescent↗
PubMed1976

Immunological studies in children before and after splenectomy.

Fourteen children underwent splenectomy for congenital spherocytosis, splenomegaly, or thrombocytopenia. The patients were studied twice before the operation, three times during the first postoperative month, and one year later. A transitory rise in neutrophils and serum IgA was seen postoperatively; there was a modest but long-lasting increase in lymphocytes and a marked elevation of eosinophils. An immediate decline in serum IgM concentration was observed only in patients with an uncomplicated postoperative course, but one year after splenectomy the average IgM concentration had decreased by 23%. The in vitro lymphocyte transformation response to a panel of mitogens and antigens fell in the immediate postoperative period but was largely normalized 10 days postoperatively, except in the youngest of the patients who had repeated infections following the splenectomy. One year postoperatively the transformation response and the number of T- and B-lymphocytes in the blood were normal.

Child↗
PubMed1975

Intra-erythrocytary enzymes before and after splenectomy.

The activity of the intraerythrocytary enzymes glucose-6-phosphate dehydrogenase, pyruvate kinase, glutathione reductase and ATPase was measured before and after splenectomy in 13 patients with congenital hemolytic anemia and 3 patients suffering from chronic thrombocytopenia. All patients were treated successfully, as reflected by clinical and basal hematological parameters. Glucose-6-phosphate dehydrogenase and pyruvate kinase were significantly depressed after splenectomy. It was not possible to set up prognostic criteria of splenectomy from the intraerythrocytary enzymes.

Adenosine Triphosphatases↗