Interstitial deletion of the long arm of chromosome 3.
A patient with multiple congenital malformations and developmental delay is reported. Her karyotype is 46,XX,del(3)(q23q25).
Abnormalities, Multiple↗
Biomedical subjects
M Ray
Publications and source records attributed to M Ray.
Methylmercury toxicity: in vivo evaluation of teratogenesis and cytogenetic changes.
Mercury is a major environmental pollutant and a proven teratogen in both animals and man. Different dose levels of methylmercuric chloride (30, 25, 15 and 5 mg/kg of body weight) were administered to pregnant ICR strain mice on day 9 of pregnancy. On gestational day 18 the animals were laparotomized. A significant increase in fetal toxicity was observed at all dose levels, except following treatment with 5 mg/kg. A marked reduction in the mean weight of fetuses from treated animals (5 mg/kg) was observed compared to the controls. Higher levels of mercury were found in maternal blood and in fetal tissues of treated animals compared to the corresponding controls. Chromosome stickiness and clumping were observed in all tissues examined (e.g., bone marrow, spleen, lung, liver) from the fetuses of treated animals. The frequency of SCEs'/cell in bone marrow cells was similar to that of controls. The results demonstrate that methylmercuric chloride, the most toxic of mercuric compounds, causes chromosome stickiness and clumping leading to reduced mitotic divisions.
Abnormalities, Drug-Induced↗
Purification and characterization of NAD and NADP-linked alpha-ketoaldehyde dehydrogenases involved in catalyzing the oxidation of methylglyoxal to pyruvate.
Two alpha-ketoaldehyde dehydrogenases, one catalyzing the oxidation of methylglyoxal to pyruvate with NAD and the other with NADP, were isolated from goat liver and happened to be co-purified. Both the enzymes had been extensively purified to the point where only these two enzymes were present. By affinity chromatography on a thiol-Sepharose column, the two enzymes were separated. Molecular weight of both the enzymes was found to be 42,000 by gel filtration in a Sephadex G-200 column. Electrophoresis on sodium dodecyl sulfate-polyacrylamide gel revealed that the enzymes are composed of single subunits. Interaction with mercurials indicated the presence of SH group(s) in the active site of the NAD-linked enzyme only.
Aldehyde Oxidoreductases↗
On the interaction of nucleotides and glycolytic intermediates with NAD-linked alpha-ketoaldehyde dehydrogenase.
The effect of different nucleotides and glycolytic intermediates was tested on the NAD-linked and NADP-linked alpha-ketoaldehyde dehydrogenases involved in the oxidation of methylglyoxal to pyruvate. ATP, GTP, and ADP strongly inhibit the NAD-linked enzyme whereas activity of the NADP-linked enzyme remained unaltered. NADP at a concentration much below its catalytic concentration strongly inhibited the NAD-linked enzyme. This NADP inhibition decreased with decreasing of the pH of the incubation medium. Fructose 1,6-bisphosphate stimulated and glyceraldehyde 3-phosphate inhibited the activity of the NAD-linked enzyme whereas dihydroxyacetone phosphate inhibited NADP-linked activity. The stimulatory effect of fructose 1,6-bisphosphate diminished with lowering of the pH value. The various effects by several key metabolites of the glycolytic pathway indicate a possible physiological role for these enzymes.
Adenosine Diphosphate↗
Homozygous Robertsonian translocations in a fetus with 44 chromosomes.
We report the unique finding of a human fetus with 44 chromosomes with homozygous 14;21 translocations. This fetus appeared phenotypically normal but the long-term neurodevelopmental outcome had this pregnancy continued could not be predicted. We speculate one 14;21 translocation was inherited from her father and one arose de novo being maternal in origin. A previous sibling with psychomotor retardation has an abnormal chromosome complement of 45,XX,dup(7)(q21 leads to pter), t(14;21)(p11;q11). The mother's underlying disease, systemic lupus erythematosis (SLE), and her prior chemotherapy may have contributed to the appearance of these chromosome aberrations. It is interesting that although 14;21 translocations are among the commonest structural chromosome rearrangements in man, there are no previous reports in newborn surveys of a child with 44 chromosomes resulting from the mating of two identical Robertsonian translocation carrier parents.
Abortion, Therapeutic↗
Dipyridamole test in angina pectoris: diagnostic value and pathophysiological implications.
The value of the dipyridamole test (0.75 mg/kg i.v.) in the diagnosis of angina pectoris was studied in 54 patients with angina pectoris (35 with angina on effort associated or not associated with rest angina and 19 with angina only at rest) and in 12 control subjects. The test induced electrocardiographic signs of ischemia (positive test) in 74% of patients with angina on effort, while it was negative in all cases with angina only at rest and in control subjects. All anginal patients with normal coronary arteries or less than 50% stenosis had a negative test; a positive response was observed in 36, 79 and 60% of cases with one-, two-or three-vessel disease, respectively. Hemodynamic changes with a marked arteriolar vasodilatation were observed both in the negative and in the positive tests. In the positive tests no significant change of double product, blood pressure and left ventricular end-diastolic pressure occurred before ischemia appeared. The results of the study show that dipyridamole as a diagnostic test in angina pectoris has a high specificity but a lower sensitivity than exercise test. The hemodynamic and eletrocardiographic findings in the positive tests suggest that dipyridamole-induced ischemia is due to a flow maldistribution with selective subendocardial ischemia secondary to the coronary arteriolar dilatation caused by the drug.
Adult↗
Isolation of methylglyoxal synthase from goat liver.
An enzyme fraction which specifically catalyzes the formation of methylglyoxal from dihydroxyacetone phosphate has been isolated and partially purified from goat liver. The enzyme fraction appears to be substantially free from glyoxalase I, reduced glutathione, and triosephosphate isomerase. Approximately equimolar quantities of methylglyoxal and inorganic phosphate were obtained from dihydroxyacetone phosphate. Formation of methylglyoxal was confirmed by colorimetric and enzymatic estimations as well as by paper chromatography and its spectrum. Glyceraldehyde-3-phosphate, fructose 1,6-bisphosphate, dihydroxyacetone, and glyceraldehyde, failed to act as substrates. The enzyme is inhibited by some phosphorylated compounds and inorganic phosphates.
Animals↗
Tachycardia-dependent and bradycardia-dependent intraventricular conduction defects in acute myocardial infarction: electrocardiographic, electrophysiologic, and clinical correlates.
Presence of rate-dependent (RD) intraventricular conduction defects (IVCD) was documented by inducing variations in heart rate in 30 acute myocardial infarction (AMI) patients (10 right bundle branch block, six left bundle branch block, 13 left anterior hemiblocks, and two left posterior hemiblocks). Five IVCDs were tachycardia-dependent (TD), 20 were bradycardia-dependent (BD), and six were both TD and BD. In TD blocks shortest cycles showing normal intraventricular conduction ranged from 410 to 1330 msec (697 +/- 84 SE); in BD blocks longest cycles with normal intraventricular conduction ranged from 450 to 1450 msec (962 +/- 52). In 60% of cases intermittent incomplete RD blocks were also present. In one patients RD-IVCD intermittency remained until discharge; in the others it lasted from 4 minutes to 10 days. Afterwards 19 RD-IVCDs disappeared and four became stable; six patients died during RD-IVCD intermittency period. Disappearance of RD block was preceded by gradual reduction in cycle length showing TD block and lengthening of cycles stopped beats with BD block. Serial observation of RD-IVCDs provides information about sequence of electrophysiologic effects on the intraventricular conduction system in clinical AMI.
Acute Disease↗
Transcriptional control in the production of liver-specific mRNAs.
cDNA clones complementary to liver mRNA were prepared and used to determine transcription rates of specific genes in isolated nuclei from liver, brain, and hepatoma cells. The cDNA sequences complementary to mRNA found only (or mainly) in the liver hybridize to labeled nuclear RNA only from liver nuclei. It appears that transcriptional events are primarily responsible for the synthesis of these, and perhaps most, tissue-specific moderately abundant mRNAs.
Animals↗
Presence of two conformationally vicinal sulfhydryl groups at the active site of UDP-glucose 4-epimerase from Saccharomyces fragilis.
UDP-glucose 4-epimerase from Saccharomyces fragilis was inactivated by diazene dicarboxylic acid bis-N,N-dimethylamide or diamide, a compound that can specifically oxidize conformationally vicinal sulfhydryl groups on protein surfaces. The inactive enzyme was shown to retain the original dimeric structure and NAD, which is a coenzyme for this reaction, was not dissociated from the apoenzyme. The loss of activity was due to the direct modification of sulfhydryl groups and could not be attributed to any subsequent loss of structural integrity. The activity of the enzyme could be regained almost completely on incubation with mercaptoethanol alone and no exogenous NAD was needed for reactivation. The reactivated enzyme showed most of the characteristic properties of the native enzyme like activation by cations or inhibition by UMP. Presence of substrate provided partial protection against inactivation by the reagent. Formation of disulfide bond(s) across the subunits was demonstrated by sodium dodecyl sulfate gel electrophoresis in absence of mercaptoethanol. Titration of native and diamide-inactivated enzyme with p-chloromercuribenzoate revealed that only two sulfhydryl groups were involved in the formation of the disulfide cross-linkage across the subunits. The above results indicate the possible presence of two conformationally vicinal sulfhydryl groups at two different subunits of the enzyme that constitute part of the active site.
Binding Sites↗
Fluorescence properties of reconstituted forms of UDP-glucose 4-epimerase from Saccharomyces fragilis.
UDP-glucose 4-epimerase from Saccharomyces fragilis exhibits a very characteristic intense fluorescence with an excitation maximum at 360 nm and an emission maximum at 433 nm. The fluorescence spectrum resembles the fluorescence of free NADH with an apparent blue shift and, although the exact nature of the fluorophore is not known, the protein-bound NAD, which is a coenzyme for this reaction, or its reduced form is obviously involved in the emission of the fluorescence. The fluorphore therefore constitutes part of the active site. The inactivation of epimerase with diazinedicarboxylic acid bis(N,N-diethylamide), a reaction shown in the previous paper to form a disulfide linkage across the subunits, results in a simultaneous and correlated loss of the characteristic fluorescence of the enzyme. Reaction with mercaptoethanol restores the native fluorescence with a 2 nm blue shift in emission maximum. These epxeriments provide additional evidence that the two conformationally vicinal sulfhydryl groups are located at the active site. Unlike the reconstituted enzyme obtained from the diamide-inactivated enzyme, the partialy active enzymes reconstituted from p-chloromercuribenzoate-inactivated and heat-inactivated enzymes fail to show the reappearance of the characteristic native fluorescence. Treatment with N-ethylmaleamide, on the other hand, leads to a form of the inactive enzyme that fully retains its fluorescent properties. A model depicting the minimal changes at the active site during the process of inactivation and reconstitution by these various treatments is presented.
Carbohydrate Epimerases↗
Gas chromatography mass spectrometry computer analysis of volatile halogenated hydrocarbons in man and his environment--A multimedia environmental study.
As part of a study to make a comparative analysis of selected halogenated compounds in man and the environmental media, a quantitative gas chromatography mass spectrometric analysis of the levels of the halogenated compounds found in the breath, blood and urine of an exposed population (Old Love Canal area, Niagara, New York) and their immediate environment (air and water) was undertaken. In addition, levels of halogenated hydrocarbons in air samples taken in the general Buffalo, Niagara Falls area were determined.
Air Pollutants↗
Treatment of angina at rest with nifedipine: a short-term controlled study.
The effectiveness of nifedipine in treating angina pectoris at rest was evaluated in 14 patients with frequent ischemic episodes associated with S-T segment elevation or depression. The trial consisted of (1) a 48 hour control period; (2) a placebo period and a period of treatment with nifedipine of 48 hours each; and (3) a second placebo period and a second period of treatment with nifedipine of 24 hours each. The efficacy of treatment was evaluated by continuous electrocardiographic recording to detect painless ischemic episodes. During coronary angiography coronary spasm was demonstrated in five patients. The ergonovine maleate test was positive in seven of eight patients. No statistically significant difference was found in the mean daily number of ischemic episodes between the control period and the first placebo period, or between the control and the second placebo periods. Nifedipine produced a highly significant reduction in the mean daily number of episodes compared with the response to placebo during the first as well as the second period. Nifedipine is effective in angina at rest caused by coronary arterial spasm. The prevention of ischemia may be related to the ability of nifedipine to decrease calcium-dependent coronary muscle tone and to prevent coronary spasm.
Adult↗
Investigations of the 1978 epidemic of encephalitis in Asansol, West Bengal and Dhanbad, Bihar.
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Adolescent↗
Partial trisomy 8 mosaicism with 46,XX/46,XX-8,+dic(8).
We report a girl with partial trisomy-8 mosaicism whose clinical findings were those of the Warkany et al. (1962) [17] or trisomy 8 syndrome. A dicentric autosome, dic(8) (qter leads to p21::p21 leads to qter), was found in all abnormal cells and evidence is presented that one centromere was inactive, allowing the dicentric to behave as a monocentric chromosome. The parents had normal karyotypes.
Centromere↗
Interstitial deletion of the long arm of chromosome 10.
A patient who had a karyotype 46,XY, del (10) (q11q21) is reported. The clinical findings in this boy included significant development delay and what appeared to be a combination of positional deformities and minor anomalies.
Abnormalities, Multiple↗