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Biomedical subjects

L Popa

Publications and source records attributed to L Popa.

At least 19 recordsLinked to original sources
PubMed2005

Phytoplankton community and hydrochemical characteristics of the Western Black Sea.

Since the early 1990s the persistent reports about the irreversibly degrading Black Sea have started to disappear. A large set of data, reflecting the temporal and spatial variability of microalgae and hydrochemical parameters in Western Black Sea waters (WBS), collected in 2001-2002 (EU 5th FP project "daNubs"), allows us to compare the present-day ecosystem functioning to previous ones and to certainly conclude on positive signs of relaxation. The years 2001 and 2002 were without ample, negative biological and hydrochemical events in the WBS. Nutrient general trend was a decreasing one since the late 1980s, and inorganic phosphorus and nitrogen concentrations were frequently below the method detection limits during summer autumn periods of 2001-2002. The shelf waters were properly oxygenated. The phytoplankton community was producing biomass in a decreasing tendency, especially obviously since 1995. Simultaneously, there was an increase in Si:P and Si:N molar ratios and concurrent increase in the diversity of mass algal species (mainly diatoms) but only a few of them generated exceptional blooms. Reduction of the ratios between phytoplankton and zooplankton biomasses became evident. The observed ecological status in 2001-2002 confirms that the Black Sea is no longer a reference point for progressive water quality deterioration.

Animals↗
PubMed1997

Interleukin 1 beta, tumour necrosis factor-alpha and interleukin 1 receptor antagonist in newly diagnosed insulin-dependent diabetes mellitus: comparison to long-standing diabetes and healthy individuals.

Interleukin 1 beta (IL-1) and tumour necrosis factor alpha (TNF) are important for the beta cell lysis in insulin-dependent diabetes mellitus (IDDM), while IL-1 receptor antagonist (IL-1ra) is considered protective by blocking the effects of IL-1. Serum concentrations and ex-vivo production of IL-1, TNF and IL-1ra were examined in 10 newly diagnosed IDDM (ND-IDDM) patients, and compared with 11 long-standing IDDM (LS-IDDM) patients and 14 healthy volunteers. Ex-vivo LPS-stimulated production of IL-1 in ND-IDDM patients was significantly increased compared with LS-IDDM patients and healthy controls, while TNF and IL-1ra synthesis did not differ significantly. IL-1ra/IL-1 ratio was significantly decreased in ND-IDDM, and returned to normal values in the LS-IDDM group. Circulating concentrations of IL-1ra in LS-IDDM patients were increased. These data suggest a proinflammatory imbalance in ND-IDDM patients and this may play an important role in beta cell loss.

Acute Disease↗
PubMed1996

Pharmacological distribution diagrams: a tool for de novo drug design.

Discriminant analysis applied to SAR studies using topological descriptors allows us to plot frequency distribution diagrams: a function of the number of drugs within an interval of values of discriminant function vs. these values. We make use of these representations, pharmacological distribution diagrams (PDDs), in structurally heterogeneous groups where generally they adopt skewed Gaussian shapes or present several maxima. The maxima afford intervals of discriminant function in which exists a good expectancy to find new active drugs. A set of beta-blockers with contrasted activity has been selected to test the ability of PDDs as a visualizing technique, for the identification of new beta-blocker active compounds.

Adrenergic beta-Antagonists↗
PubMed1983

The possibility of food contamination with cadmium by means of coloured plastics.

By using spectrophotometric atomic absorption, the release of cadmium from some plastic materials (polyethylenes, PVC, polystyrene) used for manufacturing containers, wraps and household objects (which are coloured with pigments derived from cadmium compounds) was studied. Subchronic experiments (45 days) were carried out in white Wistar rats with extracts from cadmium-containing plastic in comparison with the pigment alone. The excreted cadmium in urine and the activity of some serum enzymes were determined. Histopathological changes of the main internal organs were observed. It was found that some pigments of the Papion type have the property of releasing cadmium in amounts exceeding the admitted sanitary levels, amounts which proved to be toxic, producing enzymic and histopathological changes in kidneys and testes.

Acetates↗
PubMedDate not supplied

Screening for microdeletions in human Y chromosome--AZF candidate genes and male infertility.

About 30% of couple infertilities are of male origin, some of them caused by genetic abnormalities of the Y chromosome. Deletions in AZF region can cause severe spermatogenic defects ranging from non-obstructive azoospermia to oligospermia. The intracytoplasmatic sperm injection technique (ICSI) is rapidly becoming a versatile procedure for human assisted reproduction in case of male infertility. The use of ICSI allows Y chromosome defects to be passed from father. The goal of our study is to evaluate the frequency of microdeletions in the long arm of Y chromosome, within the AZF regions, in these cases of infertilities, using molecular genetics techniques. Thirty infertile men with azoospermia or oligozoospermia, determined by spermogram, were studied after exclusion of patients with endocrine or obstructive causes of infertility. Peripheral blood DNA was extracted from each patient, then amplified by multiplex PCR with STS genomic markers from the Y chromosome AZF zones. Each case was checked by multiplex PCR through coamplification with the SRY marker. Three men with microdeletions of the long arm of the Y chromosome were diagnosed among the 30 patients, corresponding to a proportion of 10%. The relatively high proportion of microdeletions found in our population suggest the need for strict patient selection to avoid unnecessary screening for long arm Y chromosome microdeletions. The molecular diagnostics was performed according to the current European Academy of Andrology laboratory guidelines for molecular diagnosis of Y chromosomal microdeletions.

Adult↗