Cytogenetic biomonitoring of an Italian population exposed to pesticides: chromosome aberration and sister-chromatid exchange analysis in peripheral blood lymphocytes

Chromosome aberrations (CA) and sister-chromatid exchanges (SCE) were measured in lymphocytes of (A) 32 healthy individuals working in the flower industry and exposed to pesticides, (B) 32 individuals exposed as above and hospitalized for bladder cancer, and (C) 31 controls. Compounds to which floriculturists were exposed included 18 nitro-organic herbicides and fungicides, 9 nitro-organic fungicides, 12 organophosphate and organothiophosphate insecticides, 4 hydrocarbon derivative herbicides and 5 inorganic fungicides and insecticides. 150 and 70 metaphases per individual were scored for CA and SCE, respectively. A significant increase in the incidence of CA and SCE was observed in both exposed groups. Cancer patients showed the presence of rare rearrangements (dicentrics, rings and quadriradials) that were not observed in controls and were present at a lower frequency in healthy exposed people. Hyperdiploid and polyploid metaphases were also significantly increased in the 2 exposed groups compared to controls. Stratifying for age or smoking habits, although affecting the significance of individual data, did not change the substance of the results.     

Heat Shock Proteins in Two Lines of Zea mays L. That Differ in Drought and Heat Resistance

Synthesis of heat shock proteins (HSPs) in the leaves of a drought- and heat-resistant (line ZPBL 1304), and a drought- and heat-sensitive (line ZPL 389) line of maize (Zea mays L.) was studied under two environmental stress treatments: (a) soil drying and high temperature and (b) high temperature. In the first treatment 13-day-old plants were exposed to 7-day soil drying followed by high temperature stress (45°C), and in the second treatment 20-day-old plants were exposed to high temperature stress (45°C). Second leaves were labeled with [³⁵S]methionine. During the labeling period line ZPBL 1304 showed no signs of leaf dehydration under soil drying and high temperature stress conditions. In contrast, line ZPL 389 was dehydrated 23%, as determined by relative water content. Incorporation of [³⁵S]methionine into protein was greater in the resistant than in the sensitive line in both treatments. The pattern of synthesis of HSPs in the two lines was similar in treatments 1 and 2. Both lines synthesized a high molecular mass set and a low molecular mass set of HSPs. Proteins from both sets from both lines of maize appeared similar to each other, with respect to the molecular mass. Heated plants of the drought- and heat-resistant line ZPBL 1304 synthesized a band of HSP(s) of approximately 45 kilodaltons which was not found in heated plants of the drought and heat sensitive line ZPL 389. This is the first report on qualitative intraspecific difference in the synthesis of HSPs in maize.     

Effect of methylguanidine and guanidine succinic acid on methemoglobin reductase activity in human red cells]

Activity of methemoglobin reductase was studied in human red cells treated with methylguanidine and guanidinosuccinic acid in concentrations similar to those in plasma of patients with chronic renal failure. Enzyme activity was measured with Richterich technique following an incubation at 37 degrees C for three hours. Results have shown that methylguanidine in concentration of 5.4 x 10(-5) mol/l decreases activity of methemoglobin reductase in human red cells on average by 13.9%. Higher concentrations potentiate this effect. Similar changes in methemoglobin reductase activity were noted after introduction of guanidine-succinic acid into the mixture. This agent in concentration 5.6 x 10(-5) mol/l inhibited activity of the tested enzyme by 34.2% on average. Combined methylguanidine in concentration of 5.4 x 10(-5) mol/l and guanidine-succinic acid in concentration of 2.8 x 10(-5) mol/l inhibited methemoglobin reductase activity by 33.0% on average. It may be suggested, that methylguanidine and guanidine-succinic acid being low molecular uremic toxins may significantly decrease methemoglobin reductase activity in red cells of patients with chronic renal failure.     

Echocardiographic evaluation of delayed outcome of artificial valve implantation in patients with aortic semilunar valve insufficiency]

An average follow-up period of 16 patients was 28 months following an implantation of the artificial aortic valve for its insufficiency. In 10 operated patients who were able to continue their occupation exercise tolerance increased by two classes, according to NYHA. Blood pressure gradient decreased significantly from 61.8 to 37.5 mmHg, cardiac volume index decreased from 639 to 602 ml/m2. Echocardiographically measured muscle mass of the left ventricle, end-diastolic and end-systolic volumes, and the left atrial dimensions decreased significantly following surgery. A significance of the relation of the left ventricle volume to its mass <4 as a prognostic factor in aortic valve replacement has also been confirmed.     

Activation of Plasma Membrane NADH Oxidase Activity by Products of Phospholipase A

An auxin-stimulated NADH oxidase activity (NADH oxidase I) of plasma membrane vesicles, highly purified by aqueous two-phase partition from soybean (Glycine max Merr.) hypocotyls was activated by lysophospholipids and fatty acids, both products of phospholipase A action. The activation of NADH oxidase activity occurred slowly, suggesting a mechanism whereby the lipids acted to stabilize the enzyme in a more active configuration. In contrast to activation by lipids, the activation by auxin was rapid. The average K_m of the NADH oxidase after activation by lipids was four- to fivefold less than the K_m before activation. The V_max was unchanged by activation. The increases occurred in the presence of detergent and thus were not a result of exposure of latent active sites. Also, the activation did not result from activation of a peroxidase or lipoxygenase. Fatty acid esters, where growth promoting effects have been reported, also activated the auxin-stimulated oxidase. However, the auxin stimulation of NADH oxidase I did not appear to be obligatorily mediated by phospholipase A, nor did inhibitors of phospholipase A₂ block the stimulation of the oxidase by auxins.     

Technique for repeated collection of cerebrospinal fluid from cisterna magna of anesthetized strain 13 guinea pigs

To study biochemical changes in cerebrospinal fluid (CSF), we developed a reliable technique for repeated collection of CSF in anesthetized strain 13 guinea pigs. The animal's head was mounted in a stereotaxic instrument with ventral tilt at 30 degrees, and cisternal puncture was made with an L-shaped, 23-gauge needle through the shaved skin. Clear CSF was collected in a 1-ml syringe surrounded by crushed ice. Each collection procedure lasted for 3 min, and three consecutive collections produced about 0.2 ml of CSF. Sampling was repeated at 3-hr intervals. With intravenous saline infusion (10 ml/kg.hr), a total volume of 0.6-1.0 ml of CSF was collected over 6 to 12 hr. Animals maintained a mean blood pressure, heart rate, and minute volume, with few changes during CSF sampling for the entire collection.     

The effect of intracoronary injections of x-ray contrast media on cardiac rhythm and conductivity during different variations of myocardial blood supply]

A study of the correlation between electrophysiologic effects of intracoronary injections of radiopaque agents and anatomical features of blood supply of cardiac conduction was carried out in 60 patients with intact coronary arteries. Coronary angiography was performed in all the patients. Disorders in cardiac conduction and repolarization in the myocardium were observed in intracoronary injection of radiopaque agents, which was accompanied by the development of S-A bradycardia. A bradyarrhythmic reaction type depends on prevalence of the left or right coronary artery in the atrial blood supply and cardiac conduction. The bradyarrhythmic effect was more pronounced in injection of a radiopaque agent in the right artery than in the left one.     

The effects of in vivo administration of endotoxin on the functions and interaction of hepatocytes and Kupffer cells

It was the purpose of this study to determine the effects of the in vivo administration of endotoxin on certain in vitro hepatocyte and Kupffer cell functions. An Alzet osmotic pump that contained endotoxin (LPS, 2.5 mg/100g) was implanted into the peritoneal cavity of 300g guinea pigs and delivered the endotoxin over a period of four days. In vivo administration of LPS did not cause a change in the in vitro release of albumin by isolated hepatocytes. However, when hepatocytes were co-cultured with Kupffer cells there was a significant decrease in albumin release for both control and LPS-treated animals. There was no difference between control and LPS-treated animals in the release of C3 by hepatocytes. However, there was a significant increase over the control group in C3 release by Kupffer cells from LPS-treated animals. When hepatocytes and Kupffer cells were cultured together, their release of C3 was not additive. Kupffer cells from LPS-treated animals released significantly greater amounts of PGE2 than control animals when stimulated in vitro with LPS. Thus, these Kupffer cells appeared to be primed to respond to an in vitro challenge of LPS. Kupffer cells from LPS-treated animals had significantly depressed antibody dependent cellular cytotoxicity (ADCC). This endotoxin model is useful for determining the in vivo effects of endotoxin on cellular function and gives some indirect evidence for the detrimental effects of LPS on the immune system and host defense.     

The differences in 12-hydroxyeicosatetraenoic acid and thromboxane B2 release from guinea pig platelets.

Anti-12(S)-hydroxyeicosatetraenoic acid (12-HETE)-antibody and anti-thromboxane B2 (TXB2)-antibody were generated and applied to the radioimmunoassay. The detection limit for 12-HETE was 16 pg. The cross-reactivities of anti-12-HETE-antibody were 4.6% for 15-HETE, 0.18% for 5-HETE and below 0.15% for leukotrienes and prostaglandins (PGs). 12-HETE and TXB2 released from guinea pig platelets were measured by radioimmunoassay. Platelet activating factor (PAF) at 10(-9) M induced the aggregation of platelets, the releases of immunoreactive-12-HETE (1.8 +/- 1.2 ng/10(8) platelets, mean +/- S.D.) and immunoreactive-TXB2 (18.5 +/- 17.3 ng/10(8) platelets). Collagen at 1 microgram/ml also evoked platelet aggregation, the releases of immunoreactive-12-HETE (2.7 +/- 1.1 ng/10(8) platelets) and immunoreactive-TXB2 (11.8 +/- 4.6 ng/10(8) platelets). By the stimulation with these compounds, TXB2 was produced in a greater amount than 12-HETE from guinea pig platelets. Although 10(-7) M and 10(-6) M U46619, a TXA2 mimetic, caused platelet aggregation, arachidonic acid metabolites were not released. These data suggest the presence of different mechanisms of platelet activation depending on each stimulus.