Biomedical subjects
Publications and source records attributed to S Yatziv.
Etiological relationship between a bovine strain of parainfluenza virus type 3 and pneumonia in a child is suggested. Haemagglutination inhibition tests have clearly demonstrated that specific antibodies against the bovine virus were present in the patient's serum. The significance of this finding in relation to human infection is discussed.
A 5-year-old girl with Niemann-Pick disease type C had normal eyes but the conjunctival ultrastructure was abnormal. Lamellar cytoplasmic bodies, characteristic of Niemann-Pick disease, were found in epithelial cells, stromal fibroblasts, endothelial cells, and pericytes of the stromal capillaries. The basement membrane of the capillaries was multilayered. The Golgi apparatus was unusually well developed. The combination of ocular findings and conjunctival ultrastructure may be helpful in the differential diagnosis of Niemann-Pick disease and its subtypes.
The unusual occurrence of both beta o-thalassemia and autoimmune hemolytic anemia (AIHA) in a 28-month-old child is reported to illustrate special diagnostic and therapeutic studies. The diagnosis of beta o-thalassemia was established by clinical, family and globin synthesis studies. The diagnosis of AIHA was confirmed by the shortened survival of transfused autologous and homologous red blood cells and by positive direct antiglobulin tests. During treatment of the AIHA were corticosteroids and various immunosuppressive drugs, globin synthesis studies were performed to evaluate the coincidental effects on gamma/alpha-globin chain synthetic ratios. A 50% increase in the gamma/alpha synthetic ratio during cyclophosphamide treatment suggests that further studies of the possible benefits of cytotoxic drug therapy in beta-thalassemia may be indicated.
Four hydrolases, beta-galactosidase, beta-glucuronidase, beta-N-acetylglucosaminidase and acid phosphatase were examined in red blood cells (RBC) of normal donors and patients with homozygous beta-thalassaemia. Highly sensitive fluorimetric substrates were used to determine the specific activities of these enzymes. In order to avoid contamination by lysosomal activities derived from white blood cells (WBC), the mature RBV were separated from other blood elements by cellulose chromatography. The hydrolase activities in normal RBC were detected only in their plasma membranes and were found to be considerably lower than in WBC or platelets. In thalassaemic RBC, hydrolase activities were present in both plasma membranes and in the soluble fraction. The normoblast fraction contributed most of the hydrolase activity found in these preparations, suggesting the presence of lysosomal particles in thalassaemic RBC. No differences in the enzymatic activities were found when purified membranes of mature RBC from thalassemic and normal preparations were compared. The origin and roles of these hydrolytic enzymes in normal and thalassaemic RBC membranes are not known.
A five-year-old boy of Iranian origin with multiple anomalies is described. His parents are first and second cousins. He presented with short stature, psychomotor retardation, microcephaly, ptosis, dacryostenosis, partial left nerve deafness, high arched palate, bifid uvula, total fusion between incisors, asymmetric preaxial and postaxial polysyndactyly, brachyphalangy, kyphosis and spina bifida occulta of S1. To our knowledge, a similar case has not been reported previously.
A rare case of acute promyelcytic leukemia (APL) is reported in a 7-year-old boy. The patient displayed the typical features of APL including impaction of the marrow with promyelocytes, marked elevation of the serum vitamin B12 and transcobalamin I levels and a hemorrhagic diathesis. The bleeding diathesis in the case was due to thrombocytopenia, and there was no evidence for disseminated intravascular coagulation.
Studies on the metabolism of selected amino acids were carried out in five patients with gyrate atrophy of the choroid and retina and four obligate heterozygotes. Hyperornithinemia, hyperornithinuria, and hypolysinemia were found in all patients. In one of the patients, the condition was diagnosed as early as 4 years of age. Ornithine loadings in the affected individuals did not induce the expected elevation of plasma glutamic acid and proline. Oral lysine tolerance tests in patients resulted in (1) enhancement of the hyperornithinuria and hyperlysinuria and (2) elevation of plasma lysine levels, which were below values obtained from normal controls. Supplementation of the regular diet with lysine for a period of 1 month increased plasma lysine but had no effect on plasma ornithine concentration.
Evidence is presented that both X chromosomes are genetically active in clonal cultures of undifferentiated female mouse teratocarcinoma stem cells derived from a spontaneous ovarian tumour. As the cells differentiate in vitro one of the X chromosomes becomes inactivated.
Young (60--80 days) mice of the low beta-glucuronidase strain, C3H/HeJ, showed no differences in hepatic levels of glycosaminoglycans (GAGs) when compared to the randombred, "normal" Swiss-Webster mice of the same age. However, by 12 months of age hepatic GAG is nearly twice as high in C3H/HeJ mice as in Swiss-Webster mice. Studies of beta-glucuronidase, beta-galactosidase, and N-acetyl-beta-glucosaminidase in four tissues of the two types of mice at the two ages revealed that glucuronidase was the only enzyme with lower activity in the C3H/HeJ strain.
The clinical and pathological features are described in a child with ataxia-telangiectasia, complicated by fatal disseminated herpes simplex virus infection. Herpes simplex virus was isolated from the patient's blood, and the histopathological findings in the skin, liver and adrenals were consistent with herpes simplex virus infection. The patient had a combined immune deficiency state, as a part of the ataxia-telangiectasia syndrome. She had imparied cellular immune response to herpes simplex virus and developed no antibodies against the virus. To our knowledge, this is the first fatal case of disseminated herpes simplex virus infection in ataxiatelangiectasia.
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A physiological role for glycosidases in cell membranes has been suggested. Therefore the activities of four glycosidases--beta-galactosidase, beta-glucoronidase, N-acetyl-beta-glucosaminidase and acid phosphatase--were examined in normoblasts and membranes of red blood cells (RBC). The enzymatic assays were based on the hydrolysis of fluorimetric 4-methylumbelliferone from the enzyme substrate. In order to avoid contamination by lysosomal activities derived from RBC, the mature RBC and normoblasts obtained from normal controls and thalassemic patients were separated from other blood elements by cellulose chromatography. The cells were disrupted and lysed by freezing and thawing hypotonic solution. Higher enzymatic activities were found in preparations from thalassemic patients than from normal subjects. With a sucrose density gradient, further separation of normoblasts from RBC membranes was obtained, indicating that the normoblast fraction contributed most of the high specific activity found in the thalassemic preparation. It was concluded that relatively high glycosidase activities are present in normoblasts of thalassemic patients. Lower but significant activities were detected in RBC membranes of normal control subjects and thalassemic patients.
X-linked Hunter syndrome (MPS II) is presently thought to exist in two clinically and genetically distinct forms, mild and severe, which are biochemically indistinguishable. However, two sibships have been studied in which both mildy and severely affected children are present. Therefore, genetic counseling for families with MPS II should be reconsidered to take into account the possibility of heterogeneity within a family in terms of the degree of psychomotor retardation and potential longevity.
A 2-year-old boy with macrocephaly, communicating hydrocephalus, and mild hepatosplenomegaly was found to have mild Hunter syndrome (MPS II). Establishment of the latter diagnosis was complicated by the paucity of obvious physical findings because of the patient's young age and his ethnic origin.
Profound iduronate sulfatase deficiency, characteristic of the Hunter syndrome, has been found in cultured fibroblasts, serum, lymphocytes, and tissues of two clinically affected girls. The patients are karyotypically normal and have normal fathers; cloning of the mothers' fibroblasts did not reveal the mosaicism expected of carriers of an X-linked disease. Homozygosity for a previously unsuspected autosomal recessive gene for iduronate sulfatase is considered the most likely explanation, although heterozygosity for the X-linked gene and subsequent selection cannot be completely excluded.
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Explore the source record for details and available documents.