Assay of gamma-glutamylcysteine synthetase and glutathione synthetase in erythrocytes by high-performance liquid chromatography with fluorimetric detection.
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Biomedical subjects
Publications and source records attributed to M Cipollaro.
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A reduction in mean erythrocyte volume has been reported in some strains of genetically hypertensive rat, and more recently it has been suggested that a similar alteration might be found in human essential hypertension. The relationship between erythrocyte volume and blood pressure was therefore studied in a random sample of an untreated male working population (n = 317; age 45.1 +/- 6.4 years, mean +/- s.d.). Neither systolic nor diastolic blood pressures were found to be related to erythrocyte volume (r = 0.022 and r = -0.014, respectively); in fact, erythrocyte volume was not different across quintiles of blood pressure. Smokers (n = 171) had lower blood pressure and a greater erythrocyte volume than non-smokers or ex-smokers (n = 144; 91.6 +/- 4.7 versus 88.2 +/- 5.5 fl; P less than 0.001), and heavy drinkers (greater than 110 g ethanol/day) had higher blood pressure and a greater erythrocyte volume compared with the rest of the study population (P less than 0.01). However, after adjustment of erythrocyte volume for these two potentially confounding factors, again no statistical association was found with blood pressure. The present study, therefore, does not support the hypothesis of a negative association between erythrocyte volume and blood pressure, whereas it confirms that the smoking habit and habitual alcohol intake are strong determinants of erythrocyte volume.
Dot-blot and Northern-blot experiments, using strand-specific RNA probes, show that part of the bacteriophage T4 DNA that codes for six of the base plate structural genes (gp 51, 27, 28, 29, 48 and 54), is transcribed in vivo from both DNA strands. The r DNA strand transcripts contain sequences which are translated into structural proteins. Antisense l strand RNA is about 100 fold less abundant than RNA molecules transcribed from the r DNA strand.
Sodium azide (SA) was tested on sea urchin embryos and gametes (Paracentrotus lividus). Developing embryos were exposed to SA (10(-6) to 10(-3) M) up to pluteus larval stage, or for shorter intervals before or after hatching. Developmental defects in SA-exposed embryos consisted mainly of gut abnormalities, without any detectable differences between pre- or post-hatch-exposed embryos. SA-induced damage to gut was exerted during gastrulation, as evident by lectin binding of extracellular matrix. No mitotic damage was observed in SA-exposed embryos, nor could pH-related variations be detected in SA-induced embryotoxicity at pH's ranging from 8 to 6. Concurrently, no effect ensued in the exposure of unfertilized eggs to SA (10(-5) to 10(-2) M) both in terms of fertilization success and of offspring quality. When sperm were suspended in filtered seawater at pH's ranging from 8 to 6, and SA levels ranging from 10(-5) to 10(-2) M, fertilization success of SA-exposed sperm appeared to be modulated by pH, by displaying three distinct dose-response trends at pH 8, 7, or 6. The consequences of sperm pretreatment on offspring quality failed to show any significant SA-induced changes on larval malformations or mortality, while confirming the previously reported pH-induced increase of developmental defects in the offspring of acid-exposed sperm (Pagano et al.: Teratogenesis Carcinogen Mutagen 5:113-121, 1985).
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Three different protein molecules copurify with T4 tail tubes after the tubes are released from the baseplate by guanidine hydrochloride treatment. These tube-associated proteins (TAPs) are the products of genes 29, 48, and 54. To further investigate the structural roles that these proteins may play in T4 tail assembly we have cloned and sequenced the genes coding for these proteins and have deduced their predicted amino acid sequences. The sequence data reveal a region of amino acid sequence similarity between gp54 and the T4 tail-tube structural protein, gp19. We believe that this region of similarity is significant and consistent with the role gp54 may play in initiating T4 tail-tube polymerization.
The authors evaluated technical performance of two automated haematological counters, the Coulter T-660 in comparison to Hemalog 8/90. Both systems showed a good correlation and a good precision. The Coulter T-660 revealed to be a high standard analyzer, that can adequately support more complex haematological analyzers in laboratory routine.
Further evidence is reported here of genetic and developmental damage that can be induced by a sublethal pH decrease. The effects of three inorganic acids (HCl, H2SO4, and H3PO4) on embryos and sperm from the sea urchins Sphaerechinus granularis and Paracentrotus lividus were evaluated. In addition, acidification of the medium was tested for spontaneous reversion to His+ prototrophy in Salmonella typhimurium (strains TA97, TA98, TA100, TA102, TA1535) up to toxic levels, by both liquid incubation and agar plate incorporation. The induction of developmental and mitotic abnormalities in S. granularis confirmed our previous observations on P. lividus. Embryotoxicity was exerted in S. granularis more severely by H3PO4 than by HCl or H2SO4 (pH 7 to 6), while the induction of mitotic abnormalities appeared at a pH of less than or equal to 6.5 irrespective of the acids used. By suspending S. granularis or P. lividus sperm in acidified filtered seawater (fsw) and then inseminating the eggs in natural fsw (pH = 8.0), the offspring showed developmental and mitotic abnormalities. Low-pH-induced spermiotoxicity was ruled out in our experiments, since fertilization success of acid-exposed sperm was actually enhanced, as compared to sperm suspended in untreated fsw. The exposure of S. typhimurium to different pH's (ranging from 4 to 9) invariably failed to induce any changes in reversion rates, regardless of the acids (or alkali) being used. These results suggest that extracellular acidification may cause sublethal damage that in turn leads to an impairment of mitotic activity and cell differentiation.
The effects of different pH conditions have been investigated on sea urchin larval development following exposure of embryos to controlled, though changing, decreases or increases of seawater pH. The pH of filtered natural seawater was initially adjusted with 1 N HCl of 1 N KOH and then was altered back to its normal values (8.0-8.2) by the exchange with atmospheric CO2 and subsequent carbonic acid equilibrium. During cultures, pH was regularly monitored. When developing embryos were reared in different pH conditions, larval differentiation was sharply affected by an apparently moderate pH decrease, such as 0.5 pH units. However, even pH decreases as small as 0.2 pH units from the normal value showed reproducible damage to embryogenesis. This damage appeared to be early and irreversible, since the exposure of cleaving embryos resulted in more severe developmental defects than exposure of posthatching blastulae. Moreover, mitotic abnormalities were observed following early exposure of embryos to decreased pH. Increased pH, up to 8.6 (approximately 0.5 pH units above normal value), failed to exert any adverse effect on subsequent development. Moreover, an initial pH increase (8.5-8.7) resulted in the final adjustment of culture pH to 8.1-8.2, thus providing optimal conditions for rearing embryos. Two attempts to stabilize culture pH were performed by decreasing gaseous exchanges or by using Tris as a buffering agent. Both approaches appeared to be impractical, thus ruling out any further attempts. The results point out the hazards of acid contamination in restricted bodies of seawater, leading to apparently "moderate" decreases in pH, which can result in severe damage to some marine organisms, both adult and larval forms.
pH decrease and increase were tested for their ability to affect the fertilizing capacity of sea urchin sperm, as well as to induce developmental defects and mitotic abnormalities in the embryos generated by pretreated sperm. Seawater (sw) at different pH values was obtained by mixing acidified (HCl) sw and alkalinized (KOH) sw. Thereafter sperm were exposed to different pHs for a defined time interval, or subjected to inactivation, while suspended in sw at defined pHs, as long as their fertilizing capacity was maintained. The study was carried out over the pH range 5-9; sperm showed optimal fertilizing capacity between pH 6 and 7. Below pH 6 and above pH 8 a drop in the fertilizing capacity was observed, whereas at normal sw pH (8.0-8.2) sperm showed intermediate values. pH decrease in sperm suspension induced a reproducible increase in developmental defects and mitotic abnormalities in the offspring of pretreated sperm. This effect displayed a dose-response relationship, which was most evident for pH ranging from 7 to 8. The effects of decreased pH were detected as well in terms of quantitative changes in mitotic activity, which decreased in embryos generated by sperm exposed to low pH (5-6). The results are consistent with the induction of genetic damage following exposure of sperm to low pHs. This observation suggests a genotoxic action of hydronium ions per se. Another possible explanation for the observed genotoxicity of decreased pH might be based on the pH-dependent activity of several genotoxins present in sw at trace levels.
Since the 1880s, a disparate and extensive literature has evolved examining the biologic effects of acidification on cells. More recently, effects on the health of human and other species of acidic agents contained, for example, in pollutants have been suggested, particularly relating to long-term exposures. This paper provides a review of the epidemiologic and toxicologic evidence concerning health effects--particularly carcinogenicity--attributable to sub-lethal acid exposure. Underlying biologic mechanisms that explain adverse health outcomes include pH modulation of toxicity for a number of xenobiotics (including carcinogens, genotoxins, and teratogens), and low-pH-induced changes of cells involving, for example, alterations in mitotic and enzyme regulation. More focused research is recommended to test the relationship between long-term exposures to acidic agents (with a consequent lowered cellular pH) and various health effects.