Biomedical subjects
Publications and source records attributed to A Koutselinis.
The possible effect of delta 9-THC on human erythrocyte phospholipids of chronic hashish users was studied. Changes in individual phospholipids concentrations were observed in heavy hashish users after smoking the drug. Results are discussed in relation to the possible alterations of enzymatic mechanisms which require the presence of essential for their activation phospholipids.
Plasma and hair zinc concentrations were measured by atomic absorption spectrophotometry in 34 control subjects, 20 nondialyzed uremic patients and 18 patients treated with regular hemodialysis. Plasma zinc levels were low in both nondialyzed and hemodialyzed patients. Hair zinc levels were low in the nondialyzed uremics, but at least partialy restored to normal in patients on hemodialysis. In both patient groups, hair zinc was positively correlated with plasma zinc. In the nondialyzed patients haie zinc depletion in end-stage renal disease progresses with increasing degree of renal insufficiency and tends to be reversed by regular hemodialysis.
To investigate the effect of long term hashish use on T-lymphocytes we have measured the incorporation of 14C-thymidine by peripheral blood lymphocytes, unstimulated and stimulated by phytohemagglutinin, as well as the proportion and number of E-rosettes in 12 healthy male chronic users of the drug before and after a smoking session, and in 15 control subjects. The results show that hashish smoking does not impair the response of lymphocytes to PHA, at least at the concentration of PHA used. Furthermore there is a possibility that among chronic users a hashish smoking session may have a slight stimulatory effect.
The increase of lymphocyte total lipids and phospholipids after smoking hashish, indicates either a lipid transfer from their site of production after smoking the drug or a mobilization of their biosynthetic mechanism in the lymphocyte. A fluctuation of individual phospholipid concentrations after "smoking" is related to the influence of certain hashish compounds on the various biosynthetic pathways of phospholipids in lymphocytes. Changes in phosphatidylcholine, phosphatidylinositol and phosphatidylserine are related to a possible fluctuation of the overall immune ability of the lymphocyte, by affecting the lymphocyte membrane enzyme mechanisms.
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The concentration of 2,3-diphosphoglycerate in erythrocytes was determined in 369 male and 376 female normal subjects, 1 to 86 years of age, derived from the Greek population. It was inversely correlated (P less than 0.01) with age. Persons over age 60 showed a decrease (P less than 0.05) in 2,3-diphosphoglycerate concentrations as compared those 1-20 years of age.
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The prevalence of gallstones in Athens in 1973 was studied in an autopsy survey that covered 1,448 subjects of all ages and both sexes. Gallstones were found in 5.2% of all subjects and in 6.2% of subjects older than 40 years. The prevalence was higher in females and considerably higher in persons who died from cirrhosis of the liver or from ischaemic heart disease.
2,3-Diphosphoglycerate was determined in the erythrocytes of 17 diabetic and 18 obese patients. Results for obese subjects were significantly (P less than .01) different from those obtained for 21 healthy subjects. Results for obese and diabetic patients also differed significantly (P less than .01) but not those for diabetic and healthy subjects. Hemoglobin, hematocrit, or bicarbonate measurements did not differ among the three groups.
The possible fluctuation of leukocytes and plasma lipids, 30--60 min after smoking hashish, was studied. Total phospholipid content in both leukocytes and plasma was increased in a similar way to the total lipid content after smoking hashish. Differences in most of the phospholipid classes in leukocytes and plasma before and after smoking hashish were observed while the values in controls and chronic users of the drug before smoking hashish were found to be relatively close. Findings are discussed in relation to the pharmacological action of the drug on liver lipid metabolism.
Blood lead (Pb-b) concentrations, hematocrit (Ht), and hemoglobin (Hb) were determined in three groups of men working in different parts of a cable-producing factory. All three parameters examined, i.e., Pb-b, Ht, and Hb, in the above groups were found to be within "normal" limits. However, within each group of men studied, there was a statistically significant negative correlation between Pb-b concentrations and Ht and Hb values. This finding indicates that any increase in Pb-b concentration, even within the "normal" values, may result in a decrease of hematocrit and hemoglobin values of the same subjects.
We studied blood lead levels of children who lived in 3 locations in Greece. We then compared blood lead levels in our study with results of previous studies conducted in Athens and other areas of Greece. The significant reduction of blood lead levels in Greece during the past 2 decades was obvious. We also discussed the factors responsible for the overall reduction in blood lead levels.
Blood samples were taken from, and interviews were conducted with, 76 persons injured in motor vehicle crashes, and from 126 controls with a home and leisure injury. The analysis was undertaken by modelling the data through conditional logistic regression, controlling for gender- and age-matched variables and other potentially confounding variables, including education and visual acuity. Detectable alcohol levels were associated with a 4.9 relative risk (95% confidence intervals 1.4 to 16.8). The population attributable fraction was about 10% with wide confidence intervals. There was no evidence for a safe threshold in these data. The increased injury risk associated with detectable blood-alcohol levels was disproportionally, albeit non-significantly, elevated among occasional drinkers in comparison to regular drinkers. We conclude that alcohol intake is an important cause of road traffic injuries even in the context of the Mediterranean countries where alcohol is taken in moderation and mainly in the form of wine during meals.
Zipeprol and its two main metabolites were identified in urine samples from drug abusers. Their analytical behavior during screening procedures for drugs of abuse was examined, and their basic thin-layer chromatographic and gas chromatographic-mass spectrometric analytical parameters were determined.
The metallothionein (MT) family is a class of low molecular weight, intracellular and cysteine-rich proteins presenting high affinity for metal ions. Although the members of this family were discovered nearly 40 years ago, their functional significance remains obscure. Four major MT isoforms, MT-1, MT-2, MT-3 and MT-4, have been identified in mammals. MTs are involved in many pathophysiological processes such as metal ion homeostasis and detoxification, protection against oxidative damage, cell proliferation and apoptosis, chemoresistance and radiotherapy resistance. MT isoforms have been shown to be involved in several aspects of the carcinogenic process, cancer development and progression. MT expression has been implicated as a transient response to any form of stress or injury providing cytoprotective action. Although MT participates in the carcinogenic process, its use as a potential marker of tumor differentiation or cell proliferation, or as a predictor of poor prognosis remains unclear. In the present review the involvement of MT in defense mechanisms to toxicity and in carcinogenicity is discussed.
Animal experiments suggested a possible interaction between GH or GH-dependent growth factors and bone healing. The aim of this study was to determine whether there were any significant changes in serum levels of IGF-I and/ or the activity of its receptors while a fractured bone was healing. Serum concentrations of IGF-I and its specific binding to erythrocyte receptors (IGF-I SB) were determined in a group of 12 prepubertal children treated for long bone fractures. Results were compared to those obtained from a group of age- and sex-matched controls. Blood samples were taken from all patients two weeks following the fractures, when bone formation rate should have been maximal. We found no difference in IGF-I SB between the two groups. However, serum IGF-I levels were increased in the group of children with fractures compared to controls. Results are suggestive of a possible interaction between IGF-I and bone repair processes as other investigators have suggested on the basis of animal experiments.
Autopsy was performed on 49 male cadavers and the entire course of the left testicular vein (LTV) was studied. The testicular venous pathway was divided into four levels: scrotal, inguinal, pelvic, and lumbar. At the scrotal level, many small testicular veins constituting the pampiniform plexus showed various anastomoses with the cremasteric and vasal veins. At the inguinal and pelvic level, 4-12 and 2-8 LTVs were recognized, respectively. At the pelvic level, absence of valves was seen in 33% of the cases. At the lumbar level, 1-5 LTVs were observed and were mainly anastomosed with the retroperitoneal, ureteral, and kidney capsular veins. Absence of valves at the lumbar level was seen in 37% of the cases. In 11 cases, the valves that were present were incompetent. The presence of more than one LTV at the lumbar level indicates the necessity for attentive identification of all of the testicular veins during surgical treatment of varicocele.
A 13 year-old boy with Wilson's disease was treated with zinc sulphate per os for 4 years. This treatment, which was effective and non toxic, could substitute for penicillamine as long term treatment of Wilson's disease.