Recent evidence indicates that boron and borates may have anticarcinogenic properties. In this study, we have investigated the incidence of adverse cytological findings in cervical smears and the micronucleus (MN) frequency in women living in boron-rich and boron-poor regions. Cervical smears were prepared from 1059 women with low socioeconomic status; 472 of the women lived in relatively boronrich rural areas, while 587 lived in relatively boron-poor regions. The average and standard deviation values for the age of the women screened with the cervical Pap smear test were 41.55 6 8.38. The mean dietary intake of boron was 8.41 mg/day for women from the boron-rich regions, and 1.26 mg/day for women living in the boron-poor regions (P < 0.0001). Women from the boron-rich regions had no cytopathological indications of cervical cancer, while there were cytopathological findings for 15 women from the boronpoor areas ( 2 ¼ 10.473, P < 0.05). Sixty women, 30 from each region, were chosen for evaluating MN frequencies in exfoliated buccal cells. MN frequencies for women from the boron-rich and boron-poor regions were not significantly different (t ¼ À0.294, P > 0.05). Also, there were no significant correlations between age and MN frequency for women from both the boron-rich (r ¼ 0.133, P ¼ 0.48, P > 0.05) and boron-poor (r ¼ À0.033, P ¼ 0.861, P > 0.05) regions. The results suggest that ingestion of boron in the drinking water decreases the incidence of cervical cancer-related histopathological findings. There was no correlation between the pathological findings from the cervical smears and buccal cell MN frequency suggesting that the two study populations were exposed equally to gentotoxic agents. Nonetheless, cervical cancer-related histopathological findings should be validated by other researchers. # 2007 Wiley Periodicals, Inc. Environ Toxicol 22: 17-25, 2007.

Spindle cell carcinoma is a rare biphasic tumor consisting of epithelial and mesenchymal components. Presence of this tumor type in the tongue has rarely been reported. Herein, a case of 55-year-old woman who presented with a polypoid lesion at her tongue has been reported. Surgery was performed and pathologic examination revealed a spindle cell carcinoma. We present this rare tumor with an unusual location to contribute in part to the better understanding and awareness of this rare malignancy.

Studies on boron, its mechanism and health effects are growing although the safe limits of daily boron exposure have not been clarified. Current knowledge about the toxic levels of boron on humans is not sufficient and needs to be improved. The main toxic effect of boron in animals involves the reproductive system, including specific adverse effects in the male reproductive tract in rats, mice and dogs. Boron determination in biological matrices needs sufficiently sensitive procedures for detection at trace levels, and many techniques do exist. In this paper, we reviewed the general view of potential impact of boron on health, exposure of boron and its determination techniques.

Although, the safe limits of human daily boron (B) exposure are not absolutely clear, there is a growing interest in B and its effects on human health. The aim of the present study was to estimate daily B exposure in 66 males in Turkey living in a B-rich area using water containing at least 2 mg/l boron, with an average age of 38·55 (SE 1·66) years and an average number of years of residence in the B-rich area of 35·89 (SE 1·73). Another group of males (n 57), living in the city centres of Balıkesir and Ankara, were taken as controls; the average age and number of years of residence for this group were 29·44 (SE 1·43) and 10·26 (SE 1·83) years, respectively. As it is assumed that the B level in urine reflects daily B exposure, the amount of urinary B of both the study and control groups was analysed by using an inductively coupled plasma optical emission spectrometry (ICP-OES) technique. The average daily B exposure value was calculated as 6·77 (SE 0·47) mg in the study group and 1·26 (SE 0·1) mg in the controls. The results of this study are expected to contribute to creating a reference value for a safe daily B exposure. Boron: Daily exposure: Risk assessmentRecent studies conducted both in vitro and epidemiologically have indicated that boron (B) exposure may make significant contributions to human health 1 -3 . Humans are naturally exposed to B via food and drinking water 4 . B is absorbed almost completely by the gastrointestinal and respiratory system if exposure occurs, and is mostly present in body tissues and fluids as boric acid, B(OH) 3 , and in lesser amounts as B(OH) 4 2 anion 5 . Studies indicate that B homeostasis is basically maintained by urinary excretion 6 .B was defined as a trace element in 1980 7 . In spite of the lack of epidemiological data, the WHO reported that boron may provide a physiological benefit for human health 8 . Safe and/or beneficial B levels have not been determined for humans, though animal studies have defined deleterious and beneficial B levels for animals 9 .In a study by Penland 10 , it was outlined that B improves brain function and psychomotor response. It increases steroid hormone concentrations and has antioxidant properties in postmenopausal women 9,11 . There is also evidence that B plays a role in healthy bones and joints 12,13 . Additionally, in recent years there have also been some promising results concerning the treatment of certain malignancies 14,15 .Toxicological effects have also been reported in animals at higher doses, e.g in mice, rats and rabbits skeletal malformations and cardiovascular defects have been observed 16,17 . Although not confirmed, it was claimed that B had a deleterious effect in humans, the target organ being the testis. Atrophy and eventual degeneration of the organ in several animal species at high doses have been shown 18,19 . Initially, reproduction toxicology studies were based upon data obtained from animal studies and adapted to human risk evaluations 20 . It was reported in several field studies that B does not affect human r...

Boron is absorbed by the digestive and respiratory system, and it was considered that it is converted to boric acid (BA), which was distributed to all tissues above 90 %. The biochemical essentiality of boron element is caused by boric acid because it affects the activity of several enzymes involved in the metabolism. DNA damage repair mechanisms and oxidative stress regulation is quite important in the transition stage from normal to cancerous cells; thus, this study was conducted to investigate the protective effect of boric acid on DNA damage and wound healing in human epithelial cell line. For this purpose, the amount of DNA damage occurred with irinotecan (CPT-11), etoposide (ETP), doxorubicin (Doxo), and HO was determined by immunofluorescence through phosphorylation of H2AX and pATM in the absence and presence of BA. Moreover, the effect of BA on wound healing has been investigated in epithelial cells treated with these agents. Our results demonstrated that H2AX foci numbers were significantly decreased in the presence of BA while wound healing was accelerated by BA compared to that in the control and only drug-treated cells. Eventually, the results indicate that BA reduced the formation of DNA double strand breaks caused by agents as well as improving the wound healing process. Therefore, we suggest that boric acid has important therapeutical effectiveness and may be used in the treatment of inflammatory diseases where oxidative stress and wound healing process plays an important role.

The objective of this study is to compare pure tone audiometry and auditory steady-state response (ASSR) thresholds in normal hearing (NH) subjects and subjects with hearing loss. This study involved 23 NH adults and 38 adults with hearing loss (HI). After detection of behavioral thresholds (BHT) with pure tone audiometry, each subject was tested for ASSR responses in the same day. Only one ear was tested for each subject. The mean pure tone average was 9 ± 4 dB for NH group and 57 ± 14 for HI group. There was a very strong correlation between BHT and ASSR measurements in HI group. However, the correlation was weaker in the NH group. The mean differences of pure tone average of four frequencies (0.5, 1, 2, and 4 kHz) and ASSR threshold average of same frequencies were 13 ± 6 dB in NH group and 7 ± 5 dB in HI group and the difference was significant (P = 0.01). It was found that 86% of threshold difference values were less than 20 dB in NH group and 92% of threshold difference values were less than 20 dB in HI group. In conclusion, ASSR thresholds can be used to predict the configuration of pure tone audiometry. Results are more accurate in HI group than NH group. Although ASSR can be used in cochlear implant decision-making process, findings do not permit the utilization of the test for medico-legal reasons.

Endothelial dysfunction develops as a result of oxidative stress and is responsible for diabetic vascular complications. We investigated the effects of selenium on endothelial dysfunction and oxidative stress in type 2 diabetic rats. Male Wistar rats were divided into five groups: controls, untreated diabetics, and diabetics treated with 180, 300, 500 mcg/kg selenium each day. Diabetes was induced by a single intraperitoneal injection of low dose streptozotocin to rats fed a high fat diet. Endothelium-dependent and -independent relaxations were measured in the thoracic aorta. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and endothelial nitric oxide synthase (eNOS) mRNA expressions were analyzed using real-time polymerase chain reaction (RT-PCR). Fasting blood glucose, lipid profile, lipid oxidation, insulin and nitric oxide were measured in blood samples. Malondialdehyde, superoxide dismutase, catalase and glutathione peroxidase levels were measured in liver samples. RT-PCR showed that selenium reversed increased NADPH oxidase expression and decreased eNOS expression to control levels. Selenium also improved the impairment of endothelium-dependent vasorelaxation in the diabetic aorta. Selenium treatment significantly decreased blood glucose, cholesterol and triglyceride levels, and enhanced the antioxidant status in diabetic rats. Our findings suggest that selenium restores a normal metabolic profile and ameliorates vascular responses and endothelial dysfunction in diabetes by regulating antioxidant enzyme and nitric oxide release.

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