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Biomedical subjects

D Rosenblatt

Publications and source records attributed to D Rosenblatt.

At least 19 recordsLinked to original sources
PubMed1994

Autosomal dominant polycystic kidney disease in the fetus.

We report on 3 cases with a fetal presentation of autosomal dominant polycystic kidney disease (ADPKD), which illustrate the variable expression of ADPKD during fetal life. Fetus 1 was diagnosed at 20 weeks of gestation by ultrasonography; a molecular prenatal diagnosis was performed at 10 weeks on fetus 2, a sib of fetus 1; and ADPKD was an incidental finding in fetus 3 who was aborted at 16 weeks for anencephaly. All pregnancies were terminated and pathologic studies of the fetal kidneys were performed. From these cases and a review of the literature, we draw the following conclusions: (1) so far, all fetal ADPKD kidneys that have been histologically studied have shown cystic dilatations; 28/32 of these fetuses had ultrasonographic manifestations of the disease and/or had sibs with an early-onset form of it; (2) these cysts can be found in newly formed nephrons (fetus 2), predominantly in the more mature nephrons of the deep cortex (fetus 1) or more sparsely distributed in the cortex (fetus 3); these different patterns may reflect different rates of progression of the disease; (3) in contrast to the histologic findings in adult kidneys, glomeruli seem to be predominantly affected in fetal ADPKD; (4) severe fetal expression of ADPKD seems to cluster in some families; and (5) so far, all DNA analyses performed in families with subjects presenting during the fetal or neonatal period have been consistent with linkage to the PKD1 locus.

Adult↗
PubMed1993

Tubulointerstitial nephritis in methylmalonic acidemia.

We report two patients with methylmalonic acidemia (MMA) in whom renal biopsy demonstrated interstitial nephritis, bringing the total of such reported cases to four. In addition, hypertension, observed in one of our patients, has not been previously reported as the presentation of renal disease in MMA. The etiology of interstitial nephritis in MMA did not appear to be due to urate nephropathy. To date, 15 patients with MMA have been reported with renal complications, including chronic renal failure, making it imperative that children with MMA have their renal status evaluated.

Amino Acid Metabolism, Inborn Errors↗
PubMed1988

Therapeutic approaches to cobalamin-C methylmalonic acidemia and homocystinuria.

The use of hydroxocobalamin (OH-B12), betaine, carnitine, and folinic acid were studied in two children with the cobalamin C form of methylmalonic acidemia and homocystinuria. When daily injections of 1 mg OH-B12 were discontinued for 3 weeks, there was no significant change in total plasma homocysteine or methionine levels and only a modest increase in methylmalonate. Orally administered OH-B12 1 mg/d in one patient was associated with an increase in plasma homocystine and a decrease in methionine within 1 month. Withdrawal of betaine 250 mg/kg/d was also associated with a rise in plasma homocystine and a fall in methionine levels. Carnitine 100 mg/kg/d lead to an increase in urinary excretion of propionylcarnitine, but did not affect plasma methylmalonate levels. No beneficial biochemical effect of folinic acid could be documented at a dose of 25 mg/d. Our results suggest that daily injections of OH-B12 are not necessary to maintain metabolic control and that orally administered OH-B12 is unlikely to be effective. Betaine appears to act synergistically with OH-B12 and should be part of the treatment regimen. Although there are theoretical reasons for using L-carnitine and folinic acid, we could not document their effectiveness in these two patients.

Administration, Oral↗
PubMed1987

Anticonvulsants, folate levels, and pregnancy outcome: a prospective study.

Folate levels in serum and red cells, as determined by a microbiological assay using Lactobacillus casei, and plasma anticonvulsant concentrations were monitored concurrently in nonpregnant (50 subjects) and pregnant (49 pregnancies in 46 subjects) epileptic women. Twenty-three (46%) nonpregnant women had subnormal serum folate levels and 4 nonpregnant women (8%) showed subnormal red cell folate levels. In pregnant women not taking folate supplements, the incidence of folate deficiency increased as the pregnancy advanced. Pregnant women taking folate supplements achieved normal or supranormal blood folate concentrations. In both nonpregnant and pregnant women, serum and red cell folate levels were inversely correlated with plasma concentrations of phenytoin and of phenobarbital, and with the number of anticonvulsants. In 49 pregnancies, there were 10 abnormal outcomes (20.4%): 4 spontaneous abortions (8.2%) and 6 children with major congenital malformations (12.2%). Blood folate levels were significantly lower in pregnancies with an abnormal outcome than in those with a normal outcome. The results suggest a dose-response relationship among anticonvulsants, folate, and adverse pregnancy outcome.

Abnormalities, Drug-Induced↗
PubMed1987

The glioma cell-derived neurite promoting activity protein is functionally and immunologically related to human protease nexin-I.

Protease nexin-I (PN-I, Mr approximately 43,000) is representative of a newly described class of cell-secreted protease inhibitors. PN-I has been purified to apparent homogeneity, partially sequenced, and monospecific antibodies have been raised against it. PN-I is a potent inhibitor of urokinase, thrombin, plasmin, and trypsin. In addition, cells have specific receptors that mediate the uptake of covalently linked complexes formed between PN-I and its protease substrates. In the present studies, we have investigated the relationship between human PN-I and a protease inhibitor derived from C6 glioma cells in culture that has neurite-promoting activity. On the basis of co-purification on heparin-Sepharose, identical molecular weight, antibody cross-reactivity, and receptor cross-reactivity, we conclude that PN-I and the glioma-cell-derived inhibitor are equivalent molecules.

Amyloid beta-Protein Precursor↗
PubMed1983

Chromosomal breakage in normal and fragile X subjects using low folate culture conditions.

To investigate whether the fragile X syndrome is associated with a generalised chromosomal instability, we compared the frequency and distribution of chromosomal breakage in lymphocytes grown in low folate medium from normal subjects and from patients with the syndrome. Although low folate conditions increased the rate of chromosome breakage, no difference in frequency or distribution of chromosomal breakage was found between the two groups. This suggests that the fragile X syndrome is not associated with a generalised chromosome instability expressed in folate deficient medium and assessed in terms of chromosomal breakage.

Chromosome Aberrations↗
PubMed1982

Fragile X.

Explore the source record for details and available documents.

Chromosome Fragility↗
PubMed1982

Differences in liver folate enzyme patterns in premature and full term infants.

The specific activities of four folate enzymes have been measured in livers from preterm infants (Group 1), full-term infants (Group 2), and from control subjects (Group 3). The four enzymes studied were methylene tetrahydrofolate reductase (EC 1.1.1.68), methionine synthetase (EC 2.1.1.13), methylenetetrahydrofolate dehydrogenase (EC 1.5.1.5), and glutamate formiminotransferase (EC 2.1.2.5). The specific activities for methylenetetrahydrofolate reductase were 6.62 +/- 0.51, 4.42 +/- 0.31, and 2.60 +/- 0.40 (nmoles formaldehyde/mg protein/h, mean +/- S.E.) for groups 1, 2 and 3, respectively. The specific activities for the three groups for methionine synthetase were 0.99 +/0 0.11, 0.64 +/- 0.06, and 0.42 +/- 0.05 (nmoles methionine/mg protein/h), mean +/- S.E.). The specific activities for the three groups for glutamine formiminotransferase were 84.1 +/-10.7, 108.6 +/-14.6, and 104.3 +/- 17.8 (nmoles methenyltetrahydrofolate/mg protein/min, mean +/- S.E.). The specific activities for the three groups for methylenetetrahydrofolate dehydrogenase were 0.16 +/- 0.03, 0.39 +/- 0.07, and 0.92 +/- 0.16 (nmoles methenyltetrahydrofolate/mg protein/min, mean +/- S.E.). During development, the specific activities of methylenetetrahydrofolate reductase and methionine synthetase decreased whereas the specific activity of methylenetetrahydrofolate dehydrogenase increased and that of glutamate formiminotransferase remained constant. In addition, the activities of methylenetetrahydrofolate reductase, methionine synthetase, and methylenetetrahydrofolate dehydrogenase were significantly influenced by postnatal age.

5,10-Methylenetetrahydrofolate Reductase (FADH2)↗