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Biomedical subjects

A Dona

Publications and source records attributed to A Dona.

15 recordsLinked to original sources
PubMed2005

Zinc: a multipurpose trace element.

Zinc (Zn) is one of the most important trace elements in the body and it is essential as a catalytic, structural and regulatory ion. It is involved in homeostasis, in immune responses, in oxidative stress, in apoptosis and in ageing. Zinc-binding proteins (metallothioneins, MTs), are protective in situations of stress and in situations of exposure to toxic metals, infections and low Zn nutrition. Metallothioneins play a key role in Zn-related cell homeostasis due to their high affinity for Zn, which is in turn relevant against oxidative stress and immune responses, including natural killer (NK) cell activity and ageing, since NK activity and Zn ion bioavailability decrease in ageing. Physiological supplementation of Zn in ageing and in age-related degenerative diseases corrects immune defects, reduces infection relapse and prevents ageing. Zinc is not stored in the body and excess intakes result in reduced absorption and increased excretion. Nevertheless, there are cases of acute and chronic Zn poisoning.

Aging↗
PubMed2005

Adverse effects of anabolic steroids in athletes. A constant threat.

Anabolic-androgenic steroids (AAS) are used as ergogenic aids by athletes and non-athletes to enhance performance by augmenting muscular development and strength. AAS administration is often associated with various adverse effects that are generally dose related. High and multi-doses of AAS used for athletic enhancement can lead to serious and irreversible organ damage. Among the most common adverse effects of AAS are some degree of reduced fertility and gynecomastia in males and masculinization in women and children. Other adverse effects include hypertension and atherosclerosis, blood clotting, jaundice, hepatic neoplasms and carcinoma, tendon damage, psychiatric and behavioral disorders. More specifically, this article reviews the reproductive, hepatic, cardiovascular, hematological, cerebrovascular, musculoskeletal, endocrine, renal, immunologic and psychologic effects. Drug-prevention counseling to athletes is highlighted and the use of anabolic steroids is must be avoided, emphasizing that sports goals may be met within the framework of honest competition, free of doping substances.

Aggression↗
PubMed2001

Analysis of total mercury in human tissues prepared by microwave decomposition using a hydride generator system coupled to an atomic absorption spectrometer.

A fast and efficient procedure has been developed for the analysis of total mercury in human tissues and blood using a hydride vapor generator system coupled to an atomic absorption spectrometer (HVG-AA). Tissue and blood samples were digested in a pressurized microwave decomposition system and the digest diluted prior to formation of free mercury vapor and analysis by atomic absorption. Recovery studies performed on 10 spiked/unspiked pairs of human liver and on 10 spiked/unspiked pairs of human blood samples yielded average recoveries of 99.7% (CV=0.4%) and 101.2% (CV=0.5%), respectively. The method detection limit for liver and blood was 50 microg Hg/kg and 12.5 microg Hg/l, respectively. The "normal" concentrations of mercury in human liver and blood are 33-490 microg Hg/kg and 0.6-59 microg Hg/l, respectively [1]. This method is able to determine mercury poisoning levels and may also be applied to detect mercury near the lower levels of these "normal" ranges, using the standard addition method approach.

Forensic Medicine↗
PubMed2001

Immunomodulative effects of aflatoxins and selenium on human natural killer cells.

The possible immunomodulative effects of aflatoxin B1 and selenium (as sodium selenite) at concentrations lower than 5.10(-11) M or 0.05ppb and 10(-5) M, respectively on natural killer (NK) cells from healthy volunteers were evaluated by a 51Cr release natural killer assay. Aflatoxin B1 and selenium separately had an immunosuppressive effect on NK cell activity. When they were studied in combination, they caused a statistically significant increase of the cytotoxic activity of NK cells in the presence of the lowest concentrations of aflatoxin B1 (0.005ppb) and of sodium selenite (10(-8)M).

Adjuvants, Immunologic↗
PubMed2000

Cytotoxic and immunomodulative effects of flunitrazepam, zipeprol and trihexyphenidyl on human peripheral blood lymphocytes.

The cytotoxic effects of flunitrazepam, zipeprol and trihexyphenidyl on cell viability of peripheral blood mononuclear cells from healthy volunteers were studied at concentrations from 10(-2) to 10(-8) M by 2 colorimetric in vitro assays: the neutral red uptake assay and thiazolyl blue tetrazolium bromide assay. All tested drugs of abuse were non-cytotoxic at concentrations lower than 10(-5) M. Possible immunomodulative effects of these substances were evaluated through phytohemagglutinin induced lymphocyte proliferation ([3H]-thymidine DNA incorporation assay) and by a 51Cr release natural killer assay. The 3 drugs studied produced statistically significant immunomodulative alterations on both immunological parameters.

Adjuvants, Immunologic↗
PubMed2000

The importance of performing in vitro cytotoxicity testing before immunomodulation evaluation.

This study uses the well known sensitive and reproducible human peripheral blood lymphocyte (PBL) assay as a model for the possible discrimination between cytotoxic and/or immunomodulative properties of 5 reference compounds: cadmium chloride (CdCl2): didodecyl-dimethyl ammonium bromide (DDAB); cyclosporin (CsA); dexamethasone (DEXA); and theophylline. Two colorimetric cytotoxicity assays were employed, the thiazolyl blue tetrazolium bromide and neutral red, and the H-thymidine DNA incorporation assay on phytohemagglutinin stimulated or non-stimulated PBL was used, as a parameter of cell mediated immunity. This study demonstrated the importance of performing colorimetric or other cytotoxicity assays before any investigation of mechanisms of action of different substances on immunomodulation and relative human risk assessment. This study showed that CdCl2 and DDAB have a cytotoxic rather than immunomodulative effect on PBL and that CsA, DEXA and to a lesser extent theophylline have immunomodulative rather than cytotoxic effects on PBL within the range of the concentrations studied.

Antineoplastic Agents, Hormonal↗
PubMed1999

The use of alcohol and other psychoactive substances by victims of traffic accidents in Greece.

Alcohol is one of the main causes of traffic accidents worldwide. Its use decreases significantly the driving ability of an individual as well as the reflexes of a pedestrian increasing in this way the possibilities of their involvement in motor-vehicle accidents. The above possibilities are increased when a psychoactive substance has been taken in combination with alcohol due to their synergistic effect. The Laboratory of Forensic Medicine and Toxicology of the University of Athens is authorized to perform the toxicological investigation of traffic accidents that happen in the major part of Greece. The findings of the toxicological analyses that were performed in our laboratory during the years 1995 to 1997 are classified according to the alcohol concentration and the kind of psychoactive substance detected as well as to the gender and the age of the victims, drivers or pedestrians. The results of the above classification are evaluated and the conclusions regarding alcohol, drugs and traffic accidents in Greece are discussed thoroughly.

Accidents, Traffic↗
PubMed1999

Flour contamination as a source of lead intoxication.

CASE REPORT: A 43-year-old man was hospitalized because of severe anemia and recurrent bouts of abdominal pain over 20 days. There was no known occupational exposure to toxins. Concomitantly, the patient's father complained of having the same symptoms. Familial lead poisoning was diagnosed when all 6 family members tested had high blood leads (31-64 micrograms/dL). RESULTS: Following detailed examination of the potential sources common to all members of the household, the cause of poisoning was determined to be corn flour containing 38.7 mg/g lead. Physicians are reminded to consider lead poisoning in the differential diagnosis of individuals with unexplained symptoms, particularly those of abdominal discomfort and anemia.

Abdominal Pain↗
PubMed1999

Immunomodulative effects of some drugs of abuse on human peripheral blood lymphocytes.

The cytotoxic effects of opiates, cocaine and their metabolites on peripheral blood mononuclear cells from healthy volunteers, concerning cell viability, were studied in a wide range of concentrations (ranging from 10-(2) to 10-(8) M), by 2 colorimetric in vitro assays, the neutral red uptake assay and thiazolyl blue tetrazolium bromide assay. All tested drugs of abuse and their metabolites were non-cytotoxic at concentrations lower than 10-(5) M. The possible immunomodulative effects of these substances were evaluated through phytohemagglutinin-induced lymphocyte proliferation ([3H]-thymidine DNA incorporation assay) as well as by a 51Cr release natural killer assay. The results showed immunomodulative effects of all the opiates tested. Cocaine, freebase cocaine and benzoylecgonine produced a statistically non-significant decrease of phytohemagglutinin proliferation. Cocaine induced a statistically non-significant increase, whereas freebase cocaine and benzoylecgonine showed a non-significant decrease of natural killer cell activity.

Adult↗
PubMed1998

[Determination of amphetamine derivatives in urine with solid phase micro-extraction (SPME)].

Amphetamine derivatives (amphetamine A, methamphetamine MA, 3,4-methylene-dioxy-methamphetamine MDMA, 3,4-methylene-dioxy-amphetamine MDA and 3,4-methylene-dioxy-N-ethyl-amphetamine MDE) are the first most frequently group of abused illegal drugs in Hungary. This experimental work deals with in the determination of amphetamines in connection with the forensic toxicological applicability of a relatively new isolation process, the SPME using by GC-NPD analysis. The paper demonstrates 14 types of amphetamine investigation from spiked urine samples and reports two typical amphetamine cases for SPME isolation method.

Amphetamine↗
PubMed1998

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↗
PubMedDate not supplied

Reduction of lead pollution in Greece during the past two decades.

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.

Child↗