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Biomedical subjects

L Forman

Publications and source records attributed to L Forman.

At least 19 recordsLinked to original sources
PubMed1992

Isolation of deoxyribonucleic acid (DNA) from saliva and forensic science samples containing saliva.

Saliva and saliva-stained materials were examined as potential sources of deoxyribonucleic acid (DNA) for DNA analysis and identity testing. In this paper, the authors demonstrate that DNA was isolated and DNA banding patterns suitable for DNA typing were obtained from fresh saliva and various saliva-stained materials, such as envelopes, buccal swabs, gags, and cigarettes. Furthermore, DNA and DNA banding patterns were obtained from actual forensic evidentiary samples containing mixed saliva/semen stains. The DNA banding patterns obtained from saliva or saliva-stained material were indistinguishable from the patterns obtained from blood or hair from the same individual. Intact DNA was readily isolated and DNA banding patterns were obtained from saliva stored at -20 degrees C and dried saliva stains stored under varying conditions. We conclude that saliva and saliva-stained material can be good sources of DNA for analysis and for DNA typing in certain forensic settings.

Autoradiography↗
PubMed1991

DNA sequence abnormalities of human glucose-6-phosphate dehydrogenase variants.

Over 400 supposedly biochemically and genetically distinct variants of glucose-6-phosphate dehydrogenase (G6PD) have been described in the past. In order to investigate these variants at the DNA sequence level we have now determined the relevant sequences of introns of G6PD and describe a method which allows us to rapidly determine the sequence of the entire coding region of G6PD. This technique was applied to six variants that cause G6PD deficiency to be functionally so severe as to result in nonspherocytic hemolytic anemia. Although the patients were all unrelated, G6PD Marion, Gastonia, and Minnesota each had identical mutations, a G----T at nucleotide (nt) 637 in exon 6 leading to a Val----Leu substitution at amino acid 213. The mutations of Nashville and Anaheim were identical to each other, viz. G----A at nt 1178 in exon 10 producing a Arg----His substitution at amino acid 393. G6PD Loma Linda had a C----A substitution at nt 1089 in exon 10, producing a Asn----Lys change at amino acid 363. The results confirm our earlier results suggesting that the NADP-binding site is in a small region of exon 10 and suggest the possibility that this area is also concerned with the binding of glucose-6-P.

Anemia, Hemolytic, Congenital Nonspherocytic↗
PubMed1991

Heart rate patterns in fetuses exposed to cocaine.

Heart rate patterns of 42 fetuses exposed to cocaine near the time of delivery were compared with patterns in 42 controls. Decreased long-term variability and an increased frequency of contractions were observed more often in the cocaine group (P = .046 and P = .0306, respectively). There were no significant differences in the frequency of fetal tachycardia or decelerations. Although accelerations were less frequent in cocaine-exposed fetuses, the difference compared with controls was not statistically significant. We found no characteristic heart rate pattern in fetuses exposed to cocaine near delivery. The heart rate patterns likely represent the underlying state of fetal oxygenation. Frequent contractions in an unstimulated labor should raise suspicions of maternal cocaine use.

Adult↗
PubMed1990

Gamma-glutamylcysteine synthetase deficiency and hemolytic anemia.

gamma-Glutamylcysteine synthetase is one of the enzymes of glutathione (GSH) synthesis. A deficiency of this enzyme has been found only once previously in humans: it was associated with spinocerebellar degeneration and hemolytic anemia. We report the case of a woman, daughter of fifth cousins, who was gamma-glutamylcysteine-synthetase-deficient. Modest decreases in the amount of GSH in cultured lymphoblasts and fibroblasts could be documented. The amount of residual enzyme was insufficient to permit detailed studies of the characteristics of the mutant enzymes, but no major abnormality in its Km for cysteine and glutamic acid or in its heat stability were found. In contrast to the earlier report, the only manifestation of the enzyme deficiency was hemolytic anemia. This leads us to conclude that either the occurrence of neurologic symptoms in the other reported family was a chance association or that the clinical expression of this rare defect is pleomorphic.

Adult↗
PubMed1990

In vivo aging of red cell enzymes: study of biotinylated red blood cells in rabbits.

It is generally recognized that the activities of some of the red cell enzymes decline as the cell ages. However, there is still a controversy regarding the rate at which this aging occurs. In the present study we applied newly developed technology for the specific isolation of maturing reticulocytes/erythrocytes for a more comprehensive study of in vivo aging of red cell enzymes in rabbits. Anemia was induced by repeated phlebotomy, and reticulocyte-rich erythrocytes were labeled with N-hydroxy succinimido-biotin and then transfused into a normal rabbit. These biotinylated cells were isolated at various time points by their affinity for an avidin support, and the enzymatic activity of 19 red cell enzymes was measured. We observed a biphasic pattern of decay for the activity of six age-dependent enzymes--aldolase, glutamate-oxaloacetate transaminase, glucose 6-phosphate dehydrogenase, hexokinase, pyrimidine 5'-nucleotidase, and pyruvate kinase.

Animals↗
PubMed1990

A feline large granular lymphoma and its derived cell line.

A lymphoma cell line (MCC) was derived from an abdominal mass from a 13-yr-old castrated male cat. The cells resemble natural killer precursor cells, have membrane-bound granules, and are positive for chloroacetate esterase, alpha-naphthyl butyrate esterase, and tartrate-resistant acid phosphatase activities. The MCC cells are negative for rearranged feline T-cell receptor genes, negative for feline T-cytotoxic antigen, Ia, and surface mu, tau, and lambda chains and do not form E-rosettes. The MCC cell line is negative for the feline leukemia virus (FeLV); e.g., negative for exogenous FeLV (exU3) sequences, negative for cytoplasmic and surface FeLV major core protein of 27,000 daltons (p27) by indirect immunofluorescence assay, negative for helper FeLV by clone 81 assay, and negative for release of soluble FeLV p27 by enzyme-linked immunosorbent assay. Electron microscopy reveals budding type C retrovirus particles and MCC cells react with anti-RD-114 (anti-endogenous feline retrovirus) reference serum. After in vitro infection, MCC replicate FeLV readily, but replication is noncytopathic.

Animals↗
PubMed1989

The Callimico goeldii (Primates, Platyrrhini) genome: karyology and middle repetitive (LINE-1) DNA sequences.

Callimico goeldii (Goeldi's marmoset) is a neotropical primate with 2n = 47,X1X2Y in the male, and 2n = 48,X1X1X2X2 in the female, due to a Y-autosome translocation. Karyological comparisons of Callimico, Callithrix jacchus and Cebus apella suggest that Callimico is a member of the Callitrichidae. Isozyme data and restriction mapping of LINE-1 repetitive elements in these species and in a variety of other neotropical primates confirm these findings and supply strong evidence for including Callimico in the Callitrichidae.

Animals↗
PubMed1989

Satellite DNA sequences in the neotropical marmoset Callimico goeldii (Primates, Platyrrhini).

Two families of tandemly repeated satellite DNAs were isolated from the neotropical primate Callimico goeldii (Goeldi's marmoset). One satellite, CgoA, is over 70% A + T and has a monomer length of 338 bp. The other satellite, CgoB, is 50% A + T and has a monomer length of 916 bp. Both CgoA and CgoB hybridize strongly with Callimico DNA, but not with the DNA of other new and old world primates. Based upon a neutral substitution rate of 1.5 X 10(-9)/site per year for primates, sequence data from 15 CgoA monomers indicate that the tandem array is at least 30 million years old. Since no other neotropical primate has amplified CgoA sequences, the data suggest that the ancestor of Callimico separated from the other neotropical primates at least 30 million years ago. This value is about fourfold larger than the value of 7-9 million years derived from immunological data by Sarich and Cronin (1980). Possible reasons for this discrepancy are discussed.

Animals↗
PubMed1989

Identification of the binding domain for NADP+ of human glucose-6-phosphate dehydrogenase by sequence analysis of mutants.

Human erythrocyte glucose-6-phosphate dehydrogenase is normally quite stable in the presence of 10 microM NADP+. Certain glucose-6-phosphate dehydrogenase variants lose virtually all their activity at this concentration of NADP+ but are reactivated by 200 microM NADP+. Such variants presumably have a defect in their NADP+-binding site. We analyzed the sequence of cDNA or genomic DNA from seven unrelated patients with hemolytic anemia due to the inheritance of variants that are reactivated by NADP+. Six patients had substitutions of one of three adjacent amino acids, and the seventh patient had another amino acid substitution 23 residues downstream. These amino acids are highly conserved, all being present in rat and all but one being found also in Drosophila. The anomalous electrophoretic behavior of some of the variants can be explained by their loss of ability to bind NADP+. We conclude that the region in which these mutations occur defines the binding domain for NADP+ and that binding NADP+ that has been designated as "structural" and as "catalytic" probably occurs at the same site.

Amino Acid Sequence↗
PubMed1989

Functional analysis of lymphocytes subpopulations in experimental cocaine abuse. I. Dose-dependent activation of lymphocyte subsets.

The potential role of substance abuse, especially cocaine and alcohol as co-factor in HIV infection and in the development and expression of AIDS has been suggested, but the possible biological role of substance abuse in the development of AIDS is not known. In order to better understand immune system function in chronic cocaine abuse, we have assessed primary B cell responses to helper T-cell independent (TI) and dependent (TD) antigens in inbred Fisher male rats injected with 1.25-5 mg cocaine/kg body weight for 10 days. The ability of cocaine-exposed animals to mount primary in vivo splenic plaque-forming cell (PFC) and serum antibody responses to the TI antigen, pneumococcal polysaccharide type III (SIII), was elevated several-fold when compared with controls. The degree of elevation of humoral antibody responses seemed to be directly related to the dose of cocaine. Primary in vivo B cell responses to the TD antigen, sheep red blood cells (SRBC), was elevated at lower concentrations of cocaine (1.25-2.5 mg/kg) and was found to be significantly suppressed after chronic exposure to the higher concentration (5.0 mg/kg). The elevated primary splenic immunostimulation to TI (SIII) may be attributed to a combination of loss of T suppressor cell control and direct B cell stimulation. Elevated immune responses to SRBC at lower concentrations were attributed to stimulation of T helper cells as well as loss of T suppressor cells. Immunosuppression to SRBC observed in response to 5.0 mg/kg of cocaine was most probably due to loss of T helper cell subset functions. These findings were further tested by in vitro methods, where splenic lymphocytes from cocaine-exposed animals were examined for their ability to respond to concanavalin A (Con A) in terms of the induction of antigen non-specific suppressor T cells. The addition of Con A-stimulated splenic lymphocytes from cocaine-treated animals did not inhibit the primary antibody responses of SRBC as compared with saline-treated controls, indicating that suppressor T cells malfunction after cocaine exposure. Lymphocyte subpopulation analysis using fluorescein-labelled monoclonal antibodies showed a significant increase in the B cell populations at doses of 1.25-5 mg/kg. A reciprocal change in T cell populations also took place. No significant numerical change in macrophage (NSE+) and T cell subset, T helper and T suppressor was noticed, suggesting that cocaine probably directly effects mature T cell subset functions but does not affect their differentiation.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1988

Mechanism of improved maintenance of 2,3-diphosphoglycerate in stored blood by the xanthone compound 2-(2-hydroxyethoxy)-6-(1-H-tetrazole-5-yl)xanthen-9-one (BW A440C).

The effect of the xanthone derivative 2-(2-hydroxyethoxy)-6-(1-H-tetrazole-5-yl)xanthen-9-one (BW A440C) on red cells was studied. When added to stored red cells at a concentration of 6 mM, greatly improved preservation of 2,3-diphosphoglycerate (2,3-DPG) was observed. There was no effect on internal pH of the erythrocyte. At a concentration 0.500 mM, many red cell enzyme activities were inhibited completely. At a 0.500 mM concentration, however, inhibition of pyruvate kinase and diphosphoglycerate phosphatase was most striking. Inhibition of either of these enzymes could result in elevation of 2,3-DPG levels. BW A440C in concentrations which elevated 2,3-DPG levels in humans caused a decrease in 2,3-DPG levels in rabbits and markedly impaired the viability of 21-day stored rabbit erythrocytes.

2,3-Diphosphoglycerate↗
PubMed1988

Enzymatic diagnosis in non-spherocytic hemolytic anemia.

Blood samples from 722 unrelated patients with anemia and/or reticulocytosis were submitted to our laboratory for red cell enzyme assay during the past 7 years. Among these 722 cases, we found 82 cases of 7 different red cell enzyme deficiencies and 2 of unstable hemoglobin. Abnormalities of pyruvate kinase (PK) were found to cause hemolysis in 55 patients. Although their average PK activity was about 35% of the normal level, 5 showed normal and 2 demonstrated high PK activity. Among 17 patients in whom pyruvate kinase assays or screening tests had been carried out in routine laboratories, the correct diagnoses had been made in only 4. Glucose-6-phosphate dehydrogenase (G6PD) deficiency was found in 15 patients, pyrimidine 5'-nucleotidase deficiency in 5, glucose phosphate isomerase deficiency in 3, adenylate kinase deficiency in 2, phosphoglycerate kinase deficiency in 1, and glutathione synthetase deficiency in 1 patient. Even after we performed a panel of over 20 different red cell enzyme assays, 519 patients still remained undiagnosed.

Adolescent↗
PubMed1988

Erythrocyte glutathione S-transferase deficiency and hemolytic anemia.

A patient with unexplained erythrocyte glutathione-S-transferase (GST) deficiency has been detected among 513 unrelated persons with hemolytic anemia. An otherwise healthy adult male, the deficient individual had a mild hemolytic anemia with splenomegaly, indirect hyperbilirubinemia, and cholelithiasis. Because he was adopted and childless, the hereditary nature of the defect could not be established. The residual enzyme activity was only about 15% of mean normal. Depletion of glutathione (GSH) from the cells by 1-chloro-2,4-dinitrobenzene (CDNB), a substrate for GST, was somewhat decreased in the red cells from the patient, suggesting that a functional defect existed. The kinetic properties of the residual enzyme and the ratio of activity to antigenicity were normal. Modest decreases in leukocyte and platelet GST activities were documented. Although a cause-and-effect relationship between the GST deficiency and hemolysis may exist, this cannot be proven in the absence of affected family members.

Adolescent↗
PubMed1987

Elevated pyruvate kinase activity in patients with hemolytic anemia due to red cell pyruvate kinase "deficiency".

Two patients with non-spherocytic hemolytic anemia were found to have elevated red blood cell pyruvate kinase activities commensurate with the decreased mean red cell age, but the residual pyruvate kinase had marked kinetic abnormalities. Accumulation of metabolic intermediates before pyruvate kinase and reduced levels of activity of the red blood cells of the parents of both patients supported the diagnosis of an inherited abnormal pyruvate kinase causing hemolytic anemia. Although it was observed in two unrelated persons, review of enzyme assays performed on the red blood cells of 651 patients with hereditary non-spherocytic hemolytic anemia suggests that this occurrence is rare.

Adolescent↗