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Biomedical subjects

M Vlad

Publications and source records attributed to M Vlad.

At least 37 records · Page 2Linked to original sources
PubMed1995

Effect of cuprofilin on experimental atherosclerosis.

The effect of Cuprofilin, a newly synthesized C.(II)-chlorophyll complex, was assessed in rats with experimental atherosclerosis. The study was focused on changes in serum cholesterol, lipids, and triglycerides concentration as well as on serum and abdominal aorta Cu and Zn values. It has been ascertained that after 90 d in animals fed a rich lipid diet there was a statistically significant increase in serum cholesterol, triglycerides, and lipid concentration (p < 0.01). A significant augmentation of serum Cu values (p < 0.01) accompanied by a marked lowering of the same element in abdominal aorta (p < 0.01) was also found, as compared to the results registered in the control group. However, Cuprofilin, administered for 90 d in the group of animals with experimental atherosclerosis, significantly decreased the serum cholesterol, triglycerides, and serum lipid values (p < 0.01), increased copper content in aortic tissue (p < 0.01) and lowered serum copper concentration (p < 0.01) as compared to the untreated group. Moreover, in the aorta of administered animals the lipid infiltration has been demonstrated to be significantly diminished vs the untreated group.

Administration, Oral↗
PubMed1994

Concentration of copper, zinc, chromium, iron and nickel in the abdominal aorta of patients deceased with coronary heart disease.

The Cu, Zn, Cr, Fe, and Ni concentrations from the atherosclerotic plaques in the abdominal aorta obtained from 40 patients who died of coronary heart disease (CHD) were measured. In 32 of them the clinical and anatomical diagnosis was ischemic heart disease (IHD) and in 8 of them it was acute myocardial infarction (AMI). Concomitant determinations of the concentrations of the above trace elements were determined in 16 normal aortas from subjects who died in accidents or from causes other than atherosclerosis (C). The determinations were done by means of a Perkin-Elmer atomic absorption spectrophotometer, Model 300. The results are expressed in mg/kg of dried tissue. The Cu, Zn, and Cr concentrations were significantly lower (p < 0.01) in the atherosclerotic plaques of abdominal aorta of the deceased patients with IHD and AMI than in the control group. Iron had the tendency to rise but not significantly. The nickel level in the atherosclerotic plaques from abdominal aorta did not change significantly as compared to the controls. We attribute the low values of copper in the atherosclerotic aortic tissue in IHD and AMI to a shift of copper from aortic tissue into the blood. At present, there is no explanation for the low concentration of zinc and chromium in atherosclerotic aortic tissue.

Adult↗
PubMed1993

Effect of copper sulfate on experimental atherosclerosis.

Serum copper concentration increases significantly (p < 0.01) in rats with experimental atherosclerosis compared to a control group. The serum zinc, the zinc, and copper concentration in abdominal aorta and in liver decreases significantly (p < 0.05) compared to the control group. Administration of copper sulfate for 100 d in these animals induces a significant increase of serum copper (p < 0.01), decrease of serum cholesterol (p < 0.05) and increase of liver copper concentration as compared with the group fed only a high cholesterol diet. In the aorta of these animals the copper concentration increases and edema and lipid infiltration are considerably less than in the group of animals fed only a high lipid diet.

Animals↗
PubMed1977

An investigation of some problems concerning nucleolus organizers in salamanders.

Observed differences in the sizes of lampbrush nucleolus organizers in Plethodon cinereus have been shown by in situ hybridization to reflect true molecular differences in the numbers of ribosomal cistrons located at these organizers. Likewise, from in situ hybridization experiments on lampbrush and spermatocyte chromosomes it has been shown that animals may be, and indeed usually are, heterozygous with respect to the numbers of ribosomal cistrons on each half of the nucleolus bivalent. Filter hybridizations carried out on 33 males from a New Jersey population and 20 males from a Connecticut population have shown a 7.5-fold range in the numbers of ribosomal cistrons per diploid cell in the New Jersey population, and a 2.5-fold range in the Connecticut population. In view of the general heterozygosity of nucleolus organizers in these animals, the actual range in nucleolus organizer sizes in the New Jersey population is estimated to be at least 15-fold.

Animals↗
PubMed1977

Quantitative studies of rDNA in amphibians.

The proportion of the genome that is complementary to 18 and 28 s has been determined for 12 species of amphibians. The group of species chosen for the experiment includes 5 related species belonging to the same genus (Plethodon) as well as species belonging to distant taxonomic groups whose C-values range from 3 to 62 pg. Hybridization of rRNA (18 S + 28 S) to whole chromosomal DNA to saturation level indicates that the proportion of rDNA decreases with increasing DNA content. The results presented in this paper do not support the hypothesis of Nardelli, Amaldi & Lava-Sanchez that the number of ribosomal cistrons in various amphibians can always be expressed as a power of 2.

Amphibians↗
PubMed1976

Nucleolar DNA in oocytes of Salmo irideus (Gibbons).

The amplification of ribosomal genes has been studied in oocytes from Salmo irideus. In situ nucleic acid hybridization showed that the synthesis of nucleolar DNA begins in oogonium and proceeds slowly through leptotene and zygotene when a small amount of extrachromosomal nucleolar DNA is produced. In early pachytene there is a rapid build-up of nucleolar DNA demonstrable by rapid incorporation of tritiated thymidine. Synthesis stops completely in early diplotene when nucleolar DNA becomes dispersed over the inner surface of the nuclear envelope in the form of small Feulgen-positive granules. Photometric measurements of Feulgen stained nuclei showed that the final amount of amplified nucleolar DNA synthesized in each oocyte is approximately 20 mug. The amplified DNA does not form a heterochromatic mass. The buoyant density of the amplified nucleolar DNA calculated from analytical centrifuge tracings in relation to DNA from Micrococcus luteus (rho = 1.731 g cm-3) is 1.715 g cm-3 and corresponds to a G+C content of 57%. There are indications that the buoyant density of the somatic nucleolar DNA is lower than that of amplified nucleolar DNA. Similarities and differences between ribosomal gene amplifications in oocytes of Salmo irideus and the corresponding process in Xenopus are discussed.

Animals↗
PubMed1975

Chromomere number and its genetic significance in lampbrush chromosomes.

The chromosomes of three species of salamander belonging to the genus Plethodon have been studied with regard to the absolute length of the haploid set of lampbrush chromosomes and the number and distribution of chromomeres per laploid set of lampbrush chromosomes. Each aspect has been considered in relation to the substantial difference in genome size between P. cinereus (C = 20 pg), P. vehiculum (C = 36.8 pg) and P. dunni (C = 38.8 pg). --Karyotype analyses carried out on unfixed preparations of lampbrush chromosomes showed that the absolute length of a haploid complement of lampbrush chromosomes from medium-sized yolky oocytes is much greater for P. vehiculum and P. dunni than for P. cinereus. Nonetheless, the relative dimensions of chromosomes are nearly identical in all three species. --Chromomers were counted along the whole length of the 14th (shortest) bivalent, and the total number of chromomeres in the haploid set of lampbrush chromosomes was determined by extrapolation on the basis of the known relative length of the 14th bivalent in the respective species. Chromomeres were also counted in measured segments of undamaged lampbrush preprations in which all chromosomes could be clearly identified. The average distance between chromomeres (chromomere distribution) was determined and the total chromomere number was estimated on the basis of measured total length of lampbrush chromosomes in a preparation. Chromomere distribution is the same for lampbrush chromosomes from all 3 species, and since P. vehiculum and P. dunni have longer chromosomes than P. cinereus, it is clear that the former 2 species have many more chromomeres (60-70%) per haploid set of lampbrush chromosomes. The term chromomere was used here in the descriptive sense to define a discrete granule of deoxyribonucleoprotein on the axis of a lampbrush chromosome.--These findings are discussed in relation to what is known of the molecular organization of eukaryotic genomes, and in relation to ideas on gene action and transcription in lampbrush chromosomes.

Animals↗
PubMedDate not supplied

[Intra-anesthetic hypothermia].

Oesophageal temperature was recorded after induction of anesthesia, and further, at one, two and three hours. Temperature in the operation hall was continuously monitored. In relation to the temperature in the operating hall the effects on the patient were of three kinds: 1. operating halls with low temperatures (under 21 degrees C) where all the patients become hypothermic; 2. operating halls with an intermediate temperature (21-24 degrees C), where 67% of the patients remain normothermic; 3. operating halls with high temperatures (above 24 degrees C) where all the patients remain normothermic, although these temperatures are uncomfortable for the medical personnel, and increase the septic risk of the patient. When the oesophageal temperature of the patients falls by 0.5 degrees C chills will occur in 40% of the patients. Thermal falls of less than 0.5 degrees C will also determine chills but in only 10.5% of the cases. Immediate postanesthesia chills are also recorded in normothermic patients, but there is a direct relationship between the temperature in the operating hall, the degree of hypothermia and the frequency of chills, while the site of the surgery or the duration of the operation have but an unsignificant influence on intra-anesthetic temperature.

Adult↗