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Biomedical subjects

N Başaran

Publications and source records attributed to N Başaran.

At least 19 recordsLinked to original sources
PubMed2002

Alterations of neutrophil functions in foundry and pottery workers.

To assess the immune competence of workers occupationally exposed to mainly silica, neutrophil functions such as the chemotactic and oxidative burst activity in foundry and pottery workers were evaluated. The chemotactic activity was examined in 22 foundry and 10 pottery workers and oxidative burst activity of neutrophils were determined in 22 foundry and 6 pottery workers. Healthy subjects of comparable age, sex, and smoking habits and with no history of silica exposure were used as the control groups. Chemotaxis was carried out in Boyden chambers using Zymosan activated serum as chemotactic stimulus. Oxidative burst activity was measured using nitroblue tetrazolium (NBT) dye reduction test. Both neutrophil functions were significantly reduced in silica-exposed foundry and pottery workers (p < 0.001) compared to controls suggesting that human chronic exposure mainly to silica and other chemicals originated from foundry and pottery settings may diminish neutrophil functions in humans.

Adolescent↗
PubMed2001

Effects of pesticide exposure on serum immunoglobulin and complement levels.

Serum immunoglobulins (IgG, IgA and IgM), C3 and C4 complement protein levels were examined in the male workers of the municipality who routinely applied pesticides for at least one year, and compared to healthy male controls in order to determine whether immune alterations were evident in the pesticide-exposed workers. Pyrethroids were the most commonly used pesticides for the last 3 years. Serum immunoglobulins and complement levels were measured by turbidimetry. Serum IgG, IgA, IgM and C3 complement levels were found to be unchanged when compared to controls whereas a significant decrease was observed in serum C4 complement levels of the workers.

Adult↗
PubMed2000

Effects of lead on immune parameters in occupationally exposed workers.

BACKGROUND: To assess the immune competence of workers occupationally exposed to lead, several subsets of peripheral lymphocytes, i.e., T, TCD4(+), TCD8(+), B, NK cells, serum immunoglobulin and complement protein concentrations, chemotaxis, and intracellular killing activity of neutrophils of 25 male storage battery workers have been analyzed and compared to 25 healthy males with no history of lead exposure. RESULTS: The results of this study which indicated that industrial exposure to lead resulting in group mean blood lead concentrations of 75 +/- 18 microg/dl are associated with a significant depression of: T helper lymphocytes, Ig G, Ig M and C3, C4 complement levels, chemotaxis, and random migration of neutrophils. No correlation was found between the duration of exposure and the altered immune parameters. CONCLUSIONS: The immune system can be a target for lead toxicity and elimination of lead hazard in working places is necessary.

Adult↗
PubMed1999

Effect of lipid unsaturation on the binding of native and a mutant form of cytochrome b5 to membranes.

The partitioning of native cytochrome b5 and a mutant form, where Trp-108 and Trp-112 were both replaced by Leu, into small unilamellar lipid vesicles was examined. The vesicles were made from phosphatidylcholines containing mono- and di-unsaturated acyl chains. As these amphipathic proteins self-associate in aqueous solution, the binding was not monitored by a simple lipid titration experiment but by an exchange assay using fluorescence quenching by brominated lipids. Each protein had a greater affinity for lipids containing mono-unsaturated chains than for vesicles containing di-unsaturated chains, and the affinities of both proteins increased in buffers of higher ionic strength. The native protein had a higher affinity than the mutant protein for all vesicles; the ratio of the affinities was relatively constant at approximately 30. This corresponds to a difference in the free energy of partitioning of 2 kcal mol(-)(1). The fluorescence quantum yields of both proteins were much lower in lipids with di-unsaturated chains whereas a similar lowering was not seen with a simple Trp compound. These data suggest that the decreased membrane hydrophobicity seen by the proteins in di-unsaturated membranes is not an inherent property of the bilayer but is induced by the insertion of the protein. Further, the similar behavior of the two proteins suggests this modulation is not sensitive to the amino acid side chains of the inserted domain.

Bromine↗
PubMed1999

Assessment of DNA damage in nurses handling antineoplastic drugs by the alkaline COMET assay.

The widespread use of chemotherapy in the treatment of cancer has led to anxiety about the possible hazards to staff involved in the preparation and administration of cytotoxic agents. Careless handling of antineoplastic drugs may lead to exposure in detectable amounts by means of chemical or biological methods in the body fluids or cell samples but the information about the mutagenic effects of these agents on nurses is limited and inconsistent. DNA damage in peripheral lymphocytes of 30 professional nurses employed in the oncology departments for at least 6 months were examined by the alkaline single cell gel electrophoresis, 'COMET' technique. The results were compared to that of 30 controls with comparable age, sex and smoking habits, not practising in the chemotherapy services. Work characteristics of the exposed nurses and the use of personal protective equipment were also investigated. The DNA damage observed in the lymphocytes of the nurses was significantly higher than the controls (p<0.001). The observed DNA damage was found to be significantly lower (p<0.001) in nurses applying the necessary individual safety protections during their work. Cigarette smoking was not related to increases in DNA damage, also a significant association was not found between the duration of occupational exposure to antineoplastic drugs and the DNA damage.

Adult↗
PubMed1999

Effect of protein aggregation in the aqueous phase on the binding of membrane proteins to membranes.

Analysis of the binding of hydrophobic peptides or proteins to membranes generally assumes that the solute is monomeric in both the aqueous phase and the membrane. Simulations were performed to examine the effect of solute self-association in the aqueous phase on the binding of monomeric solute to lipid vesicles. Aggregation lowered the initial concentration of monomeric solute, which was then maintained at a relatively constant value at the expense of the aggregated solute, as the lipid concentration was increased. The resultant binding isotherm has a more linear initial portion rather than the classic hyperbolic shape. Although this shape is diagnostic of solute self-association in the aqueous phase, various combinations of values for the membrane partition coefficient and the solute self-association constant will generate similar isotherms. Data for cytochrome b5 were analyzed and, when the self-association constant was estimated by gel filtration, a unique value for the membrane partition coefficient was obtained. Thus, to obtain a true partition coefficient the state of the solute in the aqueous phase must be known. If the concentration of the monomeric solute species in the aqueous phase can be independently determined, then, even with heterogeneous aggregates, the true partition coefficient can be obtained.

Animals↗
PubMed1999

Use of the alkaline comet assay to monitor DNA damage in technicians exposed to low-dose radiation.

The exposure of human beings to ionizing radiation is still of great concern in occupational and environmental medicine, and the widespread use of radiotherapy in the treatment of cancer has led to anxiety about the possible hazards to staff who are at risk of such occupational exposure. In this study, DNA damage in the peripheral lymphocytes of 30 technicians employed in radiation oncology departments for at least 1 year were examined by the alkaline single-cell gel electrophoresis "comet" technique. The results were compared with those of 30 controls with comparable age, sex, and smoking habits who were not working in radiation oncology or chemotherapy services. The DNA damage observed in the lymphocytes of the technicians was significantly higher than that in the controls (P < 0.001). Cigarette smoking was also related to increases in DNA damage, and a significant association was found between the duration of occupational exposure to low-dose ionizing radiation and the DNA damage.

Adult↗
PubMed1998

Flavonoids modulate comet assay responses to food mutagens in human lymphocytes and sperm.

The flavonoids, silymarin, myricetin, quercitin, kaempferol, rutin and kaempferol-3-rutinoside have been examined in combination with the food mutagens, 3-amino-1-methyl-5H-pyrido (4,3-b)indole (Trp-P-2) and 2-amino-3-methylimidazo-(4,5-f) quinoline (IQ), in the Comet assay in human lymphocytes from donor A and human sperm from donor B. These compounds alone have been shown to produce positive responses in the Comet assay, as have the food mutagens. However, in combination with the food mutagens, the flavonoids produced antigenotoxic effects since DNA damage was reduced in the Comet assay in lymphocytes and sperm. The assays were performed in the absence of metabolic activation, since when quercetin and kaempferol were examined in blood with metabolic activation, there was little or no difference in response to that obtained in its absence. In the blood, there was an exacerbation or synergy of response at the lowest doses of the flavonoids. In the sperm, with silymarin, myricetin and quercitin, antigenotoxic effects only were observed, but with kaempferol, in general, there were no protective effects. The food mutagen, 2-amino-1-methyl-6-phenylimadazo (4,5-b)pyridine (PhIP), was also examined in addition to Trp-P-2 and IQ in combination with silymarin and myricetin in donors A and C in human lymphocytes only. Similar exacerbation of effects were found at low doses of these flavonoids with antigenotoxic effects at high doses. This was confirmed in the Ames test. There were slightly different profiles in lymphocytes and sperm, but antigenotoxic effects were observed over a similar dose range. This would suggest that effects occur in somatic and germ cells on a one-to-one ratio. These results have implications for man in terms of risk assessment and in the modulation of isolated food constituents.

Adult↗
PubMed1998

The deletion of 22q13 region in both intracranial and spinal meningiomas in a patient (case report).

We present a 69 year old man with two simultaneous meningiomas in different compartment of neural axis, in both of which 22q13 locus is lost. Histologically the two tumours appeared to be different; meningotheliomatous and transitional with psammoma bodies, respectively. No numerical or structural chromosome abnormalities were seen in karyotype analysis of the cultured spinal and cranial meningioma samples. Since long arm structural aberrations and/or whole loss of chromosome 22 are frequently reported abnormalities of meningiomas, the tumours were also analysed by fluorescence in situ hybridisation (FISH) with different colour-labelled probes in respect to relevant chromosome. The metaphases and interphase nuclei of the samples were evaluated by the combined biotinylated 22q11 and digoxigenin-labelled 22q13 locus specific FISH probes, and 22q13 deletion was revealed in both of spinal and cranial tumour cells. In conclusion, since both tumours from the presented case show the same genetic alterations, multiplicity may be derived from the same clone of cells, and support the theory of development of multiple meningiomas from the spreading of tumour cells via cerebrospinal fluid as a possible mechanism.

Aged↗
PubMed1998

Purification and characterization of two forms of microsomal cytochrome b5 from sheep lung.

Two forms of cytochrome b5 were purified from detergent solubilized sheep lung microsomes by three successive DEAE-cellulose, Sephadex G-100 and Sephadex G-200 column chromatographies. The specific contents of cytochromes b5-I and b5-II were determined to be 45.4 and 43.8 nmol b5/mg protein, which represented up to 567 and 547-fold purification compared with that of the lung microsomes. The most striking difference between b5-I and b5-II was observed in their elution pattern from the third DEAE-cellulose column. Cytochromes gave one protein band with a Mr of 16400 +/- 500 on SDS-PAGE. Both forms of reduced b5 showed a major peak at 423 nm while reduced b5-I had two minor peaks at 527 and 556 and reduced b5-II gave two well-defined peaks at 526 and 555 nm. The ability of the purified b5-I and b5-II fractions to transfer the electrons from NADH-cytochrome b5 reductase to cytochrome c was investigated. Apparent Km, 0.055 microM, of b5-II was found to be 38% lower than that of b5-I. In addition, cytochrome b5-I was found to be more sensitive to heat treatment than b5-II when cytochromes were subjected to 62 degrees C for varying periods of time and the coupling of b5 reduction to cytochrome c reduction was determined. These results may indicate that two forms may exist in lung endoplasmic reticulum.

Animals↗
PubMed1996

Immune alterations in lead-exposed workers.

Peripheral blood lymphocytes, serum immunoglobulins (IgG, IgA and IgM), C3 and C4 complement protein concentrations of 25 male lead-exposed workers from storage-battery plants were examined and compared to 25 healthy male controls. Lead exposure was assessed using blood lead levels measured by atomic absorption spectrophotometry and zinc protoporphyrin (ZPP) levels assayed by hematofluorometry. The absolute number and the percentage of functionally different subsets of peripheral blood mononuclear lymphocytes, i.e. T, T-suppressor, B and natural killer cells, were unchanged. However, T-helper lymphocytes were significantly lower in lead-exposed workers compared to healthy controls (P < 0.05). In addition, lead-exposed workers had a significant reduction in the IgG, IgM and C3, C4 complement levels (P < 0.05). These results suggest that human chronic exposure to lead may be detrimental to the immune system.

Adult↗
PubMed1995

Confined placental mosaicism in term placentae: analysis of 125 cases.

In order to determine the incidence of confined placental mosaicism (CPM) in term placentae and to show the presence of specific sites and the effect on fetal development, 125 placentae from uneventful pregnancies were analysed by cytogenetic methods. The incidence was at least 4.8 per cent and there were no specific sites on the placenta. Although the number of cases is still too small, we found CPM to be associated with intrauterine growth retardation in six cases.

Amniocentesis↗
PubMed1995

Sister chromatid exchange analysis in acute leukemia patients.

This study was made to show the effects of acute leukemia (AL) and cytostatic drug therapy on chromosomes by sister chromatid exchange (SCE) analysis. Metaphase preparations from peripheral blood lymphocytes (PBL) of 15 patients [13 with acute nonlymphocytic leukemia (ANLL) and one with acute lymphocytic leukemia (ALL), and one with Hodgkin's disease (HD)] were harvested before and after treatment. Mean SCE frequency in the cells was 12.07 +/- 0.15 before therapy and was 14.04 +/- 0.32 after therapy as compared with 7.87 +/- 0.60 in controls. SCE values of patients with AL were significantly higher than those of controls, and this was more conspicuous in the cells that had undergone anticancer treatment.

Acute Disease↗
PubMed1995

Different influences of two fractions of lung cytochrome b5 on reconstituted lung benzphetamine N-demethylase system.

Chromatography of lung microsomal cytochrome b5 obtained from DEAE-cellulose columns, yielded two distinct cytochrome b5 fractions. These cytochrome b5 fractions were further purified by Sephadex G-100 gel filtration chromatography. The specific cytochrome b5 content of fraction 1 and fraction 2 was found to be 16.5 and 16.4 nmol/mg protein respectively. Both fractions were free of cytochrome P-450, NADPH-cytochrome P-450 reductase and NADH-cytochrome b5 reductase activities. The effects of lung cytochrome b5 (fraction 1 and fraction 2) and liver cytochrome b5 on benzphetamine N-demethylase activity were examined. Four different reconstitution systems were used. Lung cytochrome b5 fraction 2 and liver cytochrome b5 stimulated N-demethylase activity in all four systems when b5:P-450 molar ratio was low, i.e. 0.25 or 0.5. Both cytochrome b5 samples inhibited N-demethylase activity when b5:P-450 ratio exceeded 1:1 molar ratio. In contrast lung cytochrome b5 fraction 1 stimulated N-demethylase activity in all four systems. Maximal enhancement of the activity was obtained when b5:P-450 ratio was 0.5. The greatest increase in N-demethylation activity was observed in the reconstitution system with the lowest concentration of cytochrome P-450 reductase, conditions which most closely resemble intact microsomes.

Animals↗
PubMed1994

Stimulatory effects of lung cytochrome b5 on benzphetamine N-demethylation in a reconstituted system containing lung cytochrome P450LgM2.

Cytochrome b5 was partially purified from sheep lung microsomes in the presence of detergents Emulgen 913 and cholate by three consecutive DEAE-cellulose and Sephadex G-100 gel filtration chromatographies. The specific content of cytochrome b5 was 16.5 nmol/mg protein and purified cytochrome b5 fractions were free of cytochrome P450, NADPH-cytochrome P450 reductase and NADH-cytochrome b5 reductase activities. The influences of increasing concentrations of lung cytochrome b5 on benzphetamine N-demethylation reactions were examined in four different reconstitution systems containing lung cytochrome P450LgM2, lung cytochrome P450 reductase and lipid. In each system concentration of reductase was doubled with respect to former system. In all systems cytochrome b5 stimulated benzphetamine N-demethylase activity especially when cytochrome b5 was present at 0.5:1 molar ratio with respect to cytochrome P450LgM2. Besides, the greatest fold of increase in benzphetamine N-demethylation activity due to addition of cytochrome b5 was observed in System 1 with the lowest concentration of reductase.

Animals↗
PubMed1994

Humoral and cellular immune parameters in untreated and phenytoin-or carbamazepine-treated epileptic patients.

The peripheral blood lymphocyte subsets, serum immunoglobulins (Ig A, G, M), and C3 and C4 complement protein concentrations were determined in 40 healthy subjects, 30 phenytoin-treated, 22 carbamazepine-treated and 38 untreated epileptic patients. The levels of beta-lymphocytes, IgM and C3 complement proteins were found to be significantly higher in untreated epileptics than in healthy controls (P < 0.01, P < 0.02 and P < 0.05, respectively). The absolute number of beta-lymphocytes appeared to be unaffected by phenytoin or carbamazepine treatment; however, IgM levels were significantly lower in carbamazepine-treated patients than both epileptic (P < 0.01) and healthy (P < 0.05) controls. Phenytoin-treated patients had a significant reduction in the mean IgA and IgG levels compared to healthy and epileptic controls (P < 0.05). With both drug treatments, significantly lower T-suppressor lymphocyte counts and thus higher T-helper to T-suppressor lymphocyte ratios were observed with respect to healthy and epileptic controls. Our results demonstrate that while phenytoin decreases serum IgA and IgG levels, carbamazepine reduces IgM levels significantly, and untreated epileptics show immune profiles significantly different to those of healthy subjects, suggesting that epilepsy per se may be associated with certain immune aberrations induced by antiepileptic drugs.

Adolescent↗
PubMed1994

Effects of consanguinity on anthropometric measurements of newborn infants.

The effects of parental consanguinity on gestational age and birth measurements were evaluated on 2880 newborn infants. Consanguineous marriages were considered in three subgroups: first-cousin, first-cousin-once-removed and distant-cousin marriages, versus non-consanguineous marriages. Anthropometric parameters were weight, length, leg length, head, chest and mid-arm values obtained within 24 h of birth. No significant differences were found concerning gestational age. Although anthropometric values were slightly less, especially in children from first-cousin couples, the differences were insignificant for all groups. It was concluded that blood-relationship alone does not affect such multifactorial traits.

Anthropometry↗