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Biomedical subjects

A Koutselinis

Publications and source records attributed to A Koutselinis.

At least 37 records · Page 2Linked to original sources

An in vitro evaluation of fluoxetine adsorption by activated charcoal and desorption upon addition of polyethylene glycol-electrolyte lavage solution.

BACKGROUND: In drug overdoses, treatment with activated charcoal is frequently used because of its adsorptive properties. Recently, whole-bowel irrigation with polyethylene glycol-electrolyte lavage solution has been used as a gastrointestinal decontamination procedure for ingestions of toxins not well adsorbed to activated charcoal and for toxins with a delayed absorption phase, although well adsorbed to activated charcoal. While a combined approach using activated charcoal and whole-bowel irrigation could theoretically enhance the efficacy of both modalities, this improvement remains speculative, since data demonstrating its clinical advantage in overdose treatment are lacking. Fluoxetine, a selective serotonin uptake inhibitor, is one of the most frequently prescribed antidepressants. Fluoxetine is well adsorbed onto activated charcoal. This in vitro investigation was undertaken to study: a) the effect of polyethylene glycol, as well as polyethylene glycol-electrolyte lavage solution, on the adsorption of fluoxetine to laboratory grade-activated charcoal and a commercial activated charcoal formulation (Carbomix powder) in simulated gastric (pH= 1.2) and intestinal (pH=7.2) fluid environment; b) whether the order of polyethylene glycol-electrolyte lavage solution addition would have any effect on the adsorption of fluoxetine to activated charcoal. METHODS: Adsorption of fluoxetine to charcoal in the presence of polyethylene glycol was examined: a) by the simultaneous addition of polyethylene glycol and charcoal to fluoxetine solution and b) by the addition of charcoal to fluoxetine solution and subsequent addition of polyethylene glycol. In both cases, the slurries were incubated at 37 degrees C for 1 hour and filtered. Free fluoxetine concentration was determined in the diluted filtrate by a reversed-phase high-performance liquid chromatography method. RESULTS: The amount of fluoxetine adsorbed to activated charcoal (or Carbomix) was dramatically decreased at gastric and intestinal pH by the presence of polyethylene glycol or polyethylene glycol-electrolyte lavage solution added either concurrently or sequentially to activated charcoal. CONCLUSIONS: In cases of fluoxetine overdose, administration of activated charcoal is recommended, while a combined approach using activated charcoal and whole-bowel irrigation with polyethylene glycol-electrolyte lavage solution is not recommended since it causes a significant desorption of the drug from activated charcoal.

Adsorption↗

Immunological aspects of the common food colorants, amaranth and tartrazine.

We describe a sensitive and reproducible microassay model using human peripheral blood lymphocytes (PBL) for discrimination between the cytotoxic and immunosuppressive effects of food colorants such as amaranth and tartrazine. The cytotoxic effects of a wide range of concentrations of these substances were studied on human PBL by the colorimetric in vitro cytotoxicity assays, neutral red uptake (NR) and thiazolyl blue tetrazolium bromide (MTT). The immunotoxic properties of these 2 substances were determined by a [3H]-thymidine DNA incorporation assay on phytohemagglutinin stimulated or non-stimulated lymphocytes, as well as by a Cr51 release Natural Killer assays. The results showed clear immunosuppressive effects from the 2 substances tested, although the concentrations chosen for this study proved to be non-cytotoxic by NR and MTT cytotoxic endpoints.

Adult↗

Bee pseudocholinesterase as an indicator of exposure to anticholinesterase insecticides.

The inhibition of pseudocholinesterase (butyrylcholinesterase) activity is a valid and sensitive biochemical indicator of exposure to anticholinesterase insecticides and is often mandatory of the agricultural use of these pesticides. In the present work we developed a modification of an easy and sensitive technique to detect the pseudocholinesterase inhibition due to pesticide exposure. Small amounts of head tissue are needed and low concentrations of the enzyme can be detected. The determination of pseudocholinesterase inhibition is a useful biomonitor of anticholinesterase pesticide exposure for bees in the same way that it is useful for the determination of exposure in humans.

Animals↗

Effect of growth hormone therapy on bone metabolism of growth hormone deficient children.

UNLABELLED: The effects of human growth hormone (hGH) therapy on biochemical markers of bone metabolism were studied in 17 children (10 boys and 7 girls, aged 3.7-13.1 years old) with idiopathic GH deficiency, before and 1 and 6 months after GH therapy (0.5 0.7 IU/kg weekly SC). Serum levels of calcium, phosphate, alkaline phosphatase osteocalcin, parathyroid hormone, 1,25 dihydroxyvitamin D, insulin-like growth factor I (IGF-I) and renal phosphate per 100 ml glomerular filtrate (TPO4/GFR) were assessed. During therapy with hGH a significant decrease of serum calcium levels and increases of phosphate, osteocalcin, parathyroid hormone 1,25 dihydroxyvitamin D and IGF-I were observed. TPO4/GFR was also significantly increased. Growth response (increment in HV) was positively related with changes in alkaline phosphatase and IGF-I levels after 6 months of hGH therapy. There was also a significant positive correlation between increment in HV and increment in TPO4/GFR after 1 month of GH therapy, whereas no correlation between HV and changes in osteocalcin levels was found. CONCLUSION: GH treatment significantly influences mineral metabolism and the measurement of TPO4/ GFR after 1 month of GH therapy may serve as a useful predictor of growth response to hGH therapy in GH-deficient children.

Adolescent↗

Acute poisoning due to alkalis used during industrial cleaning of soft drinks' glass containers: a case report.

Corrosive alkalis are used in the soft drink and beer industries for the cleaning of the non-disposable glass containers using several different methods. It is well understood that complete cleaning of these vessels by multiple and well-organized rinsing is an absolute necessity. In cases of disturbance of this process, some residuals of alkaline agents may be retained in the glass containers, causing severe health risks to consumers. This case of acute poisoning due to caustic alkalis concerns a young woman who consumed carbonated lemonade from a non-disposable glass container. Clinical signs and symptoms and the treatment of the affected woman are described. Toxicological analysis of the soft drink consumed led to the detection, identification and quantitative determination of the presence of the alkalis.

Adult↗

Hepatic stimulator substance administration enhances regenerative capacity of hepatocytes in cadmium-pretreated partially hepatectomized rats.

The liver is of central importance in the metabolism of essential and toxic metals such as cadmium (Cd). Cd pretreatment suppressed the regenerative capacity of hepatocytes, which normally occurs 24 hr after partial hepatectomy, due to the inhibition of the activity of the enzyme thymidine kinase. The effect of hepatic stimulator substance (HSS) administration (10, 20, and 40 mg protein/kg body weight) on hepatocyte proliferation was investigated in Cd-pretreated partially hepatectomized rats. HSS administration partly restored the suppressed hepatocyte DNA biosynthesis in Cd-pretreated partially hepatectomized rats. The hepatocyte mitotic activity and the percentage of proliferating cell nuclear antigen-positive nuclei were in accordance with the liver proliferative status. The administration of HSS did not affect in a statistically significant manner the activity of the enzyme thymidine kinase in Cd-pretreated partially hepatectomized rats. It is suggested that the administration of HSS ameliorates the diminished hepatocyte regenerative response to partial hepatectomy in this model of acute liver injury, due to Cd intoxication.

Animals↗

Prostatic tissue distal to the verumontanum and its significance for adenomatous recurrences after transurethral resection of the prostate. A cadaver study.

To elucidate possible causes of recurrences after transurethral resection of the prostate (TURP), we performed an anatomical study of the prostate in 37 cadavers. The anatomical study showed that a significant proportion of the prostatic adenoma laid below the verumontanum. This proportion in relation to the total prostatic length varied from 8.33 to 44.44%, while in relation to the weight it varied from 2.08 to 36.84%. After transurethral resection of the prostatic adenoma, part of the apical lobes below the verumontanum remains intact deliberately to secure continence. These adenomatous tissues left behind create the problem of the residual apical lobe. Recent reports in the literature have shown a higher incidence of prostatic adenomatous recurrences following TURP than after open prostatectomy. From our study and from an extended search in the literature, it seems that a possible reason for adenomatous recurrences can be due to the remaining residual apical lobes that are left behind after TURP, providing that the resection had been complete.

Humans↗

Immunomodulative effects of aflatoxins and selenium on human peripheral blood lymphocytes.

We investigated the antagonist immunomodulative properties of aflatoxin B1 and selenium on human peripheral blood lymphocytes by 2 colorimetric in vitro cytotoxicity assays, the neutral red uptake and the thiazolyl blue tetrazolium bromide assay. Immunotoxic properties of these substances were determined by a (3H)-thymidine DNA incorporation assay on phytohemagglutinin (PHA) stimulated and non-stimulated lymphocytes. Aflatoxin B1 and selenium, when studied separately, had an immunosuppressive effect on PHA stimulated and non-stimulated human peripheral blood lymphocytes. When they were studied together, they had an antagonistic effect on this immunological parameter.

Adjuvants, Immunologic↗

Bee head acetylcholinesterase as an indicator of exposure to organophosphate and carbamate insecticides.

Insect acetylcholinesterase has received special attention following the discovery that inhibition of the enzyme is the mechanism of activity of the organophosphate and carbamate insecticides. Apiculture is an important source of Greek income and as the detection of anticholinesterase insecticides in bees is very difficult, investigation of the cause of death of honeybees due to acetylcholinesterase inhibition is of great value and will contribute to the differential diagnosis of bee diseases. The enzymatic assay is not capable of distinguishing between individual pesticides', but is an indicator of the exposure of bees to anticholinesterase insecticides.

Animals↗

A study of five variable number tandem repeat (VNTR) loci in the Greek population.

The use of hypervariable tandem repeat loci for population genetic studies, genetic analysis of inherited disease and individual identification purposes requires establishment of a genetic database for each reference population. In the present study we have analysed variability at five tandem repeat loci (D1S80, D17S5, 3'-hvr/apoB, F8vWF and D6S89)in a representative sample (88 to 156 individuals of greek ancestry), using polymerase chain reaction amplification. Between nine and 19 alleles were resolved throughout the five polymorphic loci. Heterozygosity indices for these loci in the greek population ranged from 0.68 to 0.85. Allele frequencies follow a bimodal discrimination (pd) and allelic diversity (h) values ranged from 0.84 to 0.94 and 0.85 to 0.91, respectively, and indicated that these loci are highly informative and can be used for population studies, forensic purposes and parentage and family testing. Comparison of observed and expected genotype frequencies by the conventional chi-square test indicated conformity to Hardy-Weinberg predictions.

Alleles↗

Lead exposure of the child population in Greece.

Lead exposure of the child population was studied in three different areas in Greece: Kalamata which is a rural area of Southern Greece; Tavros, a district of Athens with a considerable industrial activity; and Lavrion, a small city near Athens where a lead-zinc mining and smelting industrial complex has existed for more than 90 years. The results were evaluated with respect to a number of individual, social and environmental variables (i.e. smelter, occupation of the father) especially those concerning the area of Lavrion which is the most heavily polluted area in Greece. The results of this study can be considered as an index for the extent of the lead pollution problem in the named areas of Greece.

Analysis of Variance↗

Metallothionein expression during liver regeneration after partial hepatectomy in cadmium-pretreated rats.

Metallothionein is a low molecular mass protein inducible mainly by heavy metals, having high affinity for binding cadmium, zinc and copper. In the present study we investigated the expression of metallothionein in regenerating liver, at different time intervals, in cadmium pretreated partially hepatectomized rats. Liver metallothionein is highly expressed during regeneration induced by partial hepatectomy in rats, providing zinc within the rapidly growing tissue. Cadmium pretreatment caused inhibition of the first peak of liver regeneration, while metallothionein expression was markedly more prominent in the liver residues of cadmium-pretreated rats. These results demonstrate that although metallothionein able to bind temporarily metal ions as zinc and cadmium has been highly expressed, the liver regenerative process was inhibited possibly due to the effects of cadmium on other pivotal events necessary to the DNA replication.

Animals↗

Perinatal death and thymus gland.

Three hundred (300) cases of perinatal death were autopsied and the thymus was removed for histologic examination. The histologic findings were classified into five groups: a) normal-mature thymus, b) involutional changes--"Starry sky" pattern, c) involutional changes--intense lymphocytic depletion, d) hypoplasia--aplasia, e) agenesis. The perinatal deaths were classified into five groups according to Wigglesworth's classification: 1) normally formed macerated stillborn neonates, 2) congenital malformations, 3) conditions associated with immaturity, 4) asphyxial conditions developing in labor, 5) other specific conditions (e.g. known-beta-hemolytic streptococcal infection or a fatal inborn error of metabolism). The main objective was to identify a possible correlation between sex, gestational age, birth weight, thymus weight, histologic features of the thymus and cause of death. In conclusion, a strong correlation was found between: a) weight of thymus and gestational age, b) weight of thymus and birth weight, c) weight of thymus and its histologic features, d) histologic features of thymus and cause of death, e) weight of thymus and cause of death, f) gestational age and cause of death. No correlation was found between: a) gestational age and histologic features of thymus, b) birth weight and histologic features of thymus, c) weight of thymus and sex, d) histologic features of thymus and sex, e) cause of death and sex.

Birth Weight↗

Expression of alpha-thymosins in human tissues in normal and abnormal growth.

Radioimmunoassays specific for the N and C termini of human prothymosin alpha and the N terminus of human parathymosin alpha were employed for the measurement of the levels of alpha-thymosins in human thymus, spleen, and liver during normal growth and intestine and breast in malignant growth. A differential expression of the two alpha-thymosins was observed in thymus (prothymosin alpha-rich) and liver (parathymosin alpha-rich). A decline in the levels of both alpha-thymosins was found with age, with prothymosin alpha in thymus showing the sharpest change (15- to 30-fold). The levels of both alpha-thymosins were higher in malignant tissues as compared with healthy ones. In breast cancer, in particular, the mean increase for prothymosin alpha and parathymosin alpha was 17.9- and 11.5-fold, respectively. The major crossreactive material was characterized in all cases as intact prothymosin alpha and parathymosin alpha. These results suggest an in vivo relationship of the expression of alpha-thymosins with the human tissue cell proliferation activity.

Adolescent↗

Attitudes of a Mediterranean population to the truth-telling issue.

The attitudes of the Greeks, a Mediterranean population, to the issue of telling the truth to the patient have been studied. There is no clear answer to the question: 'Do the Greeks wish to be informed of the nature of their illness?'. The answer is: 'It depends'. It depends on age, education, family status, occupation, place of birth and residence and on whether or not they are religious people. However, it does not depend on their sex--men and women have similar reactions to the issue of truth-telling. Although the present study shows lower percentages of those who wish to know the truth than studies on other populations, the conclusion is that, emphasising the need for good communication between doctors and patients, doctors should not lie, but should disclose to their patients the part of the truth they are ready to accept.

Adult↗

Exposure to lead and cadmium of children living near a lead smelter at Lavrion, Greece.

Exposure of children of the Greek town of Lavrion to lead and cadmium has been evaluated by determination of the levels of lead (PbB) and cadmium (CdB) in the blood of 514 children living in the town. The Lavrion area is heavily polluted by lead owing to the presence of a large lead-zinc mining and smelting industrial complex. The industrial PbB level (geometric mean) was 21.7 micrograms dl-1 (range 7.4-79.8 micrograms dl-1). The CdB levels were, on average, 0.36 micrograms l-1 (range 0.1-3.1 micrograms l-1). The results were evaluated with respect to a number of constitutional, social and environmental variables, such as age, gender, distance of the school from the lead-zinc mining and smelting complex, and occupation and education of the father.

Age Factors↗