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Biomedical subjects

A Mazur

Publications and source records attributed to A Mazur.

At least 109 records · Page 6Linked to original sources
PubMed1995

Painful keratoderma and photophobia: hallmarks of tyrosinemia type II.

Tyrosinemia type II (Richner-Hanhart syndrome), which is caused by a deficiency of hepatic tyrosine aminotransferase, results in elevated plasma and urinary tyrosine concentrations. We describe a young boy who was seen at 6 months of age with red eyes, photophobia, and eye pain that were not suspected to be caused by tyrosinemia II until painful plantar keratoderma developed at 2 1/2 years of age. Treatment with a diet low in tyrosine and phenylalanine reversed the manifestations of the disease.

Amino Acid Metabolism, Inborn Errors↗
PubMed1995

Hypercholesterolemia induced by cholesterol- or cystine-enriched diets is characterized by different plasma lipoprotein and apolipoprotein concentrations in rats.

This study examined the effects of diet-induced hypercholesterolemia on plasma apolipoprotein (apo) concentrations and hepatic apolipoprotein mRNA levels in rats. Hypercholesterolemia was induced by feeding rats diets containing an excess of either cholesterol or cystine. After cholesterol feeding, plasma apo E and apo B concentrations were lower (-65%, P < 0.001) and greater (+39%, P < 0.01), respectively, compared with control diet-fed rats. After cystine feeding, plasma apo B and apo E concentrations were greater (+46%, P < 0.01 and +75%, P < 0.001, respectively) and plasma apo A-IV concentration was lower (-29%, P < 0.001) than in rats fed control diet. After cholesterol or cystine feeding, a tendency (one-way ANOVA, P = 0.08) for greater apo B mRNA level (+42% and +47%, respectively) was observed compared with control diet-fed rats. No difference emerged between groups for apo E and apo A-I mRNA levels. An opposite effect of cholesterol and cystine feeding was shown for apo A-IV mRNA level, i.e., higher after cholesterol feeding (+47%, P < 0.05) and lower after cystine feeding (-65%, P < 0.01). From this work, it seems that hypercholesterolemia induced by dietary cholesterol or by increased cholesterogenesis in cystine-fed rats is characterized by different plasma lipoprotein and apolipoprotein concentrations and is associated with different apolipoprotein gene expression in the liver.

Actins↗
PubMed1995

ST segment depression in lateral limb leads in inferior wall acute myocardial infarction. Implications regarding the culprit artery and the site of obstruction.

We examined whether the pattern of ST segment depression in lateral leads (I, aVL, V5, V6) in the initial electrocardiogram of patients (n = 88) with inferior wall acute myocardial infarction (ST segment elevation of > or = mm in > or = 2 inferior leads) correlates with the site of obstruction, as determined angiographically during acute hospitalization. Of the 62 patients in which the culprit artery could be determined unequivocally, in 46 the culprit artery was the right coronary artery (20 proximal to the first right ventricular branch and 26 distal), and in 16 the left circumflex coronary artery (seven proximal to the first marginal branch or involving a high first marginal branch, and nine with distal obstruction). Significant ST segment depression (ST < or = 1 mm) in leads I and aVL was more common in right coronary artery obstruction (P < 0.05 and P < 0.0001, respectively). The absence of significant ST segment depression in lead aVL was most common in proximal circumflex obstruction (P < 0.0001), with a similar trend for lead I (P < 0.11). ST segment depression patterns in leads V5 and V6 were not indicative of the infarct-related artery or the site of obstruction. Thus, significant ST segment depression in leads I and aVL indicates right coronary artery-associated inferior wall acute myocardial infarction with a sensitivity of 70% and 100%, and a specificity of 63% and 38%, respectively, whereas the lack of ST segment depression in these leads indicates proximal circumflex obstruction with a sensitivity of 71% and 86%, and a specificity of 65% and 100%, respectively.

Coronary Angiography↗
PubMed1995

Anemia in copper-deficient rats: role of alterations in erythrocyte membrane fluidity and oxidative damage.

This study was designed to make precise the nature and the mechanism of the anemia induced by dietary copper (Cu) deficiency. Male Wistar rats were pair fed from weanling for 6 wk either a Cu-deficient or a control diet. The reduced red blood cell (RBC) 51Cr survival indicates an increased destruction of RBC during Cu deficiency. 1,6-Diphenyl-1,3,5-hexatriene fluorescence polarization studies revealed an increase in the fluidity of erythrocyte membranes from deficient rats. The reduced cholesterol-to-phospholipid ratio was consistent with the increased fluidity. Other results indicate an increased vulnerability of RBC to hemolysis in dilute hydrogen peroxide and an increased formation of lipid peroxidation products. Before exposure to free radical stress, electron spin resonance studies in intact RBC revealed decreased correlation time of 16-doxyl-stearic acid, confirming a more fluid membrane in RBC from Cu-deficient rats. After in vitro peroxidation, RBC from Cu-deficient rats showed a more ordered state of membrane lipids compared with controls. Together, these studies demonstrate the hemolytic nature of the anemia. The shortened survival of erythrocytes apparently results from changes in membrane fluidity and enhanced susceptibility to peroxidation.

Anemia↗
PubMed1995

Triglyceride-rich lipoproteins from magnesium-deficient rats are more susceptible to oxidation by cells and promote proliferation of cultured vascular smooth muscle cells.

An important characteristic of hyperlipaemia associated with magnesium deficiency in rats is the postprandial accumulation of triglyceride-rich lipoproteins (TGRLP). The present investigation was performed to determine the susceptibility of TGRLP isolated from magnesium-deficient rats to metal ion and cell dependent peroxidation and the effect of these lipoproteins on cultured vascular smooth muscle cells (VSMC). TGRLP were isolated by sequential ultracentrifugation from plasma of control and magnesium-deficient rats fed for 8 d on adequate or magnesium-deficient diets. Magnesium-deficient animals were hypertriglyceridemic as compared to control rats. After exposure to oxidative stress in vitro, Cu2+ or activated macrophages, conjugated diene production was significantly higher in TGRLP isolated from magnesium-deficient rats. Culture of VSMC with TGRLP from magnesium-deficient rats resulted in more important cell growth than with lipoproteins isolated from control animals. After incubation with VSMC, TGRLP from magnesium-deficient rats showed higher conjugated diene production than those from control rats. These results support the atherogenic properties of magnesium deficiency, which is accompanied by hyperlipaemia and which affects two important linked pathways in atherosclerosis, lipoprotein peroxidation and VSMC proliferation.

Animals↗
PubMed1995

Effect of magnesium deficiency on triacylglycerol-rich lipoprotein and tissue susceptibility to peroxidation in relation to vitamin E content.

Given the current interest in the cardiovascular complications of Mg deficiency, the aim of the present experiment was to investigate the effect of Mg deficiency on the time-course of lipoprotein oxidation and to assess whether short-term Mg deficiency results in vitamin E depletion that predisposes lipoproteins and tissues to subsequent oxidation. Weanling rats were pair-fed for 8 d with control and Mg-deficient diets respectively. Plasma triacylglycerol and alpha-tocopherol levels were significantly greater in Mg-deficient rats compared with control animals. The increase in plasma apolipoprotein B concentration indicated that a corresponding increase in plasma triacylglycerol-rich lipoproteins (TGRLP) occurred in Mg-deficient animals. Hyperlipaemia was associated with modifications in the composition of TGRLP. The proportion of triacylglycerols was elevated whereas that of cholesterol and protein was reduced, and Mg deficiency resulted in a slight significant reduction in alpha-tocopherol content. When the TGRLP fractions were subjected to in vitro Cu-induced oxidation the lipoprotein fractions from Mg-deficient rats were more susceptible to oxidative damage than lipoprotein fractions from control rats. Mg deficiency did not modify the alpha-tocopherol content of liver, heart and skeletal muscle. However, after exposure of tissue homogenates to Fe-induced lipid peroxidation, thiobarbituric acid-reactive substances were significantly higher in tissues from Mg-deficient rats compared with those from control rats. These results complement previous findings, showing that Mg deficiency increases the susceptibility of TGRLP and tissues to peroxidation and suggest that oxidative damage is not the result of a decrease in vitamin E antioxidant status.

Animals↗
PubMed1995

[Analysis of brain tumors in children from the Rzeszów region].

The authors present an analysis of brain tumors diagnosed in the pediatric ward of the voivodship hospital in Rzeszów between 1988 and 1992. Age, sex and clinical manifestation leading to hospitalisation, localisation and histopathology of the tumors were assessed.

Adolescent↗
PubMed1995

Magnesium deficiency in rats induces a rise in plasma nitric oxide.

Magnesium deficiency in rats leads to an oxidative stress involving an increased production of radical oxygen species. The present study was designed to examine the effect of experimental magnesium deficiency on plasma nitric oxide (NO) level and nitric oxide synthases (NOS) activities in rats. The data show that the concentration of NO is markedly increased in plasma of magnesium-deficient rats. This rise in plasma NO results from activation of inducible nitric oxide synthase (iNOS) rather than of the constitutive form (cNOS) of the enzyme. These data are in agreement with previous observations indicating that inflammation occurs during magnesium-deficiency and provide an additional cause of oxidative lesions through formation of peroxynitrite from nitric oxide and superoxide anion.

Animals↗
PubMed1994

Clinical significance and predisposing factors to symptomatic bradycardia and hypotension after percutaneous transluminal coronary angioplasty.

Of 180 consecutive patients who underwent uneventful percutaneous transluminal coronary angioplasty (PTCA), 25 (13.9%) had at least 1 episode of symptomatic bradycardia and hypotension during the early postprocedure period. Symptomatic bradycardia and hypotension occurred 1 to 10 hours (mean 4 +/- 2) after PTCA. A higher incidence of symptomatic bradycardia and hypotension was found in patients receiving regular treatment with beta blockers (26% vs 10% in patients without beta blockers in their regimen, p < 0.01), diltiazem or verapamil (20% vs 9%, p < 0.025), or both a beta blocker and diltiazem or verapamil (64% vs 11%, p < 0.001). A higher incidence was also associated with angioplasty of the left anterior descending coronary artery compared with angioplasty of the other coronary arteries (22% vs 8%, p < 0.01). It is concluded that symptomatic bradycardia and hypotension is a common occurrence after PTCA. The incidence is higher after PTCA to the left anterior descending coronary artery and in patients receiving diltiazem, verapamil, and beta-blocking agents; it is particularly high in patients receiving a combination of a beta-blocking agent and either diltiazem or verapamil.

Adrenergic beta-Antagonists↗
PubMed1994

Apolipoprotein A-I, A-IV and E synthesis in the liver of copper-deficient rats.

Copper deficiency induces hypercholesterolemia in the rat. This hypercholesterolemia is mainly due to an increase in apo E-rich high density lipoproteins (HDL1). The present study was undertaken to determine whether the HDL increase could be explained by altered low-molecular weight apolipoprotein (apo) synthesis in the liver. The effect of copper deficiency on apo A-I, apo A-IV and apo E concentrations in plasma, as well as on respective mRNA levels and synthesis in the liver, were therefore investigated. We observed that the increased HDL1 levels in the plasma of copper-deficient rats were associated with a significant rise in plasma apo E concentrations; however, plasma apo A-I and apo A-IV concentrations remained unchanged. Liver apo synthesis and respective apo mRNA levels were not significantly altered in copper-deficient animals when compared to control rats. No changes in apo E mRNA levels in various tissues from copper-deficient, as compared to control rats, were noted. Based on the data obtained, it was concluded that the observed changes in plasma lipoprotein and apo concentrations are not related to changes in low-molecular weight apo synthesis in the liver. The mechanisms of the impaired catabolism of HDL1 should be further evaluated to possibly explain the observed increase in this fraction in copper-deficient rats.

Animals↗
PubMed1994

Effect of the interruption of enterohepatic circulation of bile acids by cholestyramine on apolipoprotein gene expression in the rat.

The aim of the study was to assess how the interruption of enterohepatic circulation may affect the regulation of apolipoprotein synthesis. For this purpose, apolipoprotein mRNA levels were measured in the liver and small intestine of male Wistar rats fed for 3 weeks diets with or without cholestyramine (5% w/w). In order to modulate intestinal lipid flux, we used diets with 2 or 10% lipid content. Cholestyramine treatment decreased plasma triglyceride and cholesterol concentrations (by 63% and 32%, respectively) in rats fed 10% corn oil containing diet but had no significant effect on plasma lipids in rats fed a low-fat diet. Plasma apo B and apo A-IV concentrations were lowered by cholestyramine treatment in both 10 and 2% oil fed groups; however plasma apo E concentration was only affected in rats receiving 10% corn oil in the diet. Cholestyramine treatment had no significant effect on plasma apo A-I concentration. Hepatic apo B, apo E and apo A-IV mRNA levels were similar among dietary groups. Cholestyramine administration caused an increase in hepatic apo A-I mRNA level only in rats fed low-fat diet. In the intestine cholestyramine treatment decreased apolipoprotein mRNA levels in jejunum but had a few effect on apolipoprotein mRNA levels in ileum. These experiments have shown that long-term decrease in the intraluminal availability of bile acids may alter not only lipid and lipoprotein metabolism but also the regulation of apolipoprotein synthesis.

Animals↗
PubMed1994

Effect of simvastatin treatment on plasma apolipoproteins and hepatic apolipoprotein mRNA levels in the genetically hypercholesterolemic rat (RICO).

The effects of long-term treatment with simvastatin on plasma lipoproteins, plasma apolipoproteins, and on hepatic apolipoprotein gene expression were evaluated in genetically hypercholesterolemic (RICO) rats. Simvastatin administration caused a decrease in plasma triglyceride and phospholipid concentrations. Plasma cholesterol concentration was not changed by simvastatin, but cholesterol distribution among plasma lipoproteins was altered. Plasma apo B, apo A-I, and apo A-IV concentrations were lowered by simvastatin treatment whereas plasma apo E concentration was not affected by this drug. In the liver, simvastatin treatment induced a significant decrease of apo E mRNA level but had no effect on apo B, apo A-I, and apo A-IV mRNA abundances. It appears that simvastatin may modify plasma apolipoprotein concentrations by influencing their hepatic synthesis at both pre- and posttranscriptional levels.

Animals↗
PubMed1994

Do cortisol and thyroxin correlate with nervousness and depression among male army veterans?

Elevated cortisol is recognized as a transient response to stress, and is also found among patients with major depressive disorder. Abnormally high levels of thyroxin are associated with nervousness and irritability, while very low levels are associated with lethargy. Therefore it is reasonable to ask if variations in cortisol and thyroxin within a normal population are associated with differences in anxiety and depression. These expectations were tested in a large sample of male army veterans. Nervousness is significantly associated with both thyroxin and cortisol, although several other symptoms of anxiety or depression are not.

Adult↗
PubMed1994

Fermentable polysaccharides that enhance fecal bile acid excretion lower plasma cholesterol and apolipoprotein E-rich HDL in rats.

The effect of different polysaccharides fermented in the large intestine and liable to lower plasma cholesterol was investigated in rats. Male rats were assigned to one of five treatment groups: control diet or a diet containing pectin, guar gum, gum arabic or beta-cyclodextrin. The four compounds were effectively fermented, yielding cecal short-chain fatty acids (SCFA) concentrations in the range of 130 to 170 mmol/L. Relative to controls, the cecal concentration of propionate was significantly higher in rats fed all fibers, especially those fed guar gum (+190%) or beta-cyclodextrin (+385%). All the fermented carbohydrates elicited a significant cholesterol-lowering effect, which was most potent in rats fed guar gum or beta-cyclodextrin, the two fibers that also significantly depressed plasma triglycerides. These two carbohydrates significantly lowered LDL and HDL1 cholesterol, triglyceride-rich lipoprotein triglycerides and apolipoprotein E levels. Apolipoprotein B was lowered only by beta-cyclodextrin. The microsomal activities of hydroxymethylglutaryl (HMG) CoA reductase and of cholesterol 7 alpha-hydroxylase were markedly elevated in rats fed guar gum or beta-cyclodextrin and, to a lesser extent, in those fed pectin compared with controls. Increased bile acid excretion seems to be essential in the cholesterol-lowering effect of soluble fibers and related compounds. This effect is connected to induction of HMG CoA reductase and lowering concentrations of apolipoprotein E-containing particles.

Animals↗
PubMed1994

Chromosomes are highly elastic and can be stretched.

Direct manipulation of human chromosomes in metaphase spreads using glass needles revealed that the consistency of chromosomes varies depending on their moisture content. Chromosomes are soft and highly elastic under wet conditions and are hard when dry. The elasticity of chromosomes is comparable to rubber threads and can be used for stretching experiments under phase contrast microscopy, after Giemsa staining, and after GTG-banding. The coiling structures of the chromosomes appear to be stretched evenly along the length of the chromosome. Chromosomes fixed for only a short time have a tendency to tear when stretched more than 5 times their length. Under the experimental conditions used, chromosomes were preferentially torn in the centromeric region. Chromosome stretching on GTG-banded human chromosomes leads to a splitting of bands into their subbands. This may be useful for creating new high resolution ideograms possibly showing more than 1700 bands per haploid set.

Biomechanical Phenomena↗
PubMed1994

[How does one detect biological imbalance and health disorders in the dairy cow within the framework of ecopathological research?].

The methods of detection of health and biological imbalances in the dairy cow, which can be performed in ecopathological studies, are presented. Mastitis, metritis, liver disorders, nutritional imbalances, reproductive disorders, stress, specific diseases and non-specific inflammations are reviewed. The possible future evolutions are analyzed.

Animal Nutritional Physiological Phenomena↗