Highly sensitive chemiluminescence immunoassay for benzo[a]pyrene-DNA adducts: validation by comparison with other methods,and use in human biomonitoring

A chemiluminescence immunoassay (CIA) utilizing antiserum elicited against DNA modified with (+/-)-7beta, 8alpha-dihydroxy-9alpha,10alpha-epoxy-7,8,9,10-tetrahydrobenzo[a]- pyrene (BPDE) has been developed and validated to study the formation of polycyclic aromatic hydrocarbon (PAH)-DNA adducts in human tissues. Advantages include a low limit of detection for 10b-(deoxyguanosin-N(2)-yl)-7beta,8alpha,9alpha-trihydroxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BPdG, approximately 1.5 adducts/10(9) nucleotides using 20 micro g DNA) and a high signal-to-noise ratio (> or =100). The CIA BPDE-DNA standard curve gave 50% inhibition at 0.60 +/- 0.08 fmol BPdG (mean +/- SE, n = 30), which was a 10-fold increase in sensitivity compared with the dissociation-enhanced lanthanide fluoroimmunoassay (DELFIA). Calf thymus DNA modified with [1,3-(3)H]BPDE was assayed by radiolabeling, (32)P-postlabeling, DELFIA and CIA, and all assays gave similar values. Liver DNAs from mice exposed to 0.5 and 1.0 mg [7,8-(3)H]benzo[a]pyrene (BP) were assayed by the same four assays and a dose-response was obtained with all assays. The BPDE-DNA CIA was further validated in MCL-5 cells exposed to 4 micro M BP for 24 h, where nuclear and mitochondrial DNA adduct levels were associated with an increase in DNA tail length measured by the Comet assay. Human peripheral blood cell (buffy coat) DNA samples (n = 43) obtained from 25 individuals who were either colorectal adenocarcinoma patients or controls were assayed by BPDE-DNA CIA. Three samples (7%) were non-detectable, and the remaining 40 samples had values between 0.71 and 2.21 PAH-DNA adducts/10(8) nucleotides. The intra-assay coefficient of variation (CV), for four wells on the same microtiter plate, was 1.85%. Sufficient DNA for two assays, on separate plates, was available for 38 of the 43 samples, and the PAH-DNA adduct values obtained were highly correlated (r(2) = 0.95). Coded duplicate DNA samples from 15 individuals were assayed four times gave an inter-assay CV of 13.8%.     

Prophylactic role of melatonin against radiation induced damage in mouse cerebellum with special reference to Purkinje cells.

Melatonin, a hormone with a proven antioxidative efficacy, crosses all morphophysiological barriers, including the blood-brain barrier, and distributes throughout the cell. The present study is an attempt to investigate the prophylactic influence of a chronic low level of melatonin against an acute radiation induced oxidative stress in the cerebellum of Swiss albino mice, with special reference to Purkinje cells. After 15 days of treatment the mice were sacrificed at various intervals from 1 to 30 days. Biochemical parameters included lipid peroxidation (LPO) and glutathione (GSH) levels as the endpoints. The quantitative study included alterations in number and volume of Purkinje cells. Swiss albino mice were orally administered a very low dose of melatonin (0.25 mg/mouse/day) for 15 consecutive days before single exposure to 4 Gy gamma radiation. Melatonin checked the augmented levels of LPO, by approximately 55%, by day 30 day post-exposure. Radiation induced depleted levels of GSH could be raised by 68.9% by day 30 post-exposure. Radiation exposure resulted in a reduction of the volume of Purkinje cells and their total number. The administration of melatonin significantly protected against the radiation induced decreases in Purkinje cell volume and number. Results indicate the antioxidative properties of melatonin resulting in its prophylactic property against radiation induced biochemical and cellular alterations in the cerebellum. The findings support the idea that melatonin may be used as an anti-irradiation drug due to its potent free radical scavenging and antioxidative efficacy.     

Effect of soft contact lens on central visual field

The effect of soft contact lenses (CLs) and spectacles on central visual fields was assessed in 48 eyes. Forty-three eyes (89.5%) showed smaller pattern standard deviation in CL wearers than five eyes (10.5%) with spectacles. In addition, 38 CL wearers (79%) showed higher positive mean deviation values than 10 eyes (20.8%) with spectacles. Findings indicate the pattern of visual fields shifts toward normalcy in CL wearers. The authors have stated that they do not have a significant financial interest or other relationship with any product manufacturer or provider of services discussed in this article. The authors also do not discuss the use of off-label products, which includes unlabeled, unapproved, or investigative products or devices.     

Peribulbar oncocytoma: high-frequency ultrasound with histopathologic correlation.

The clinical, ultrasonographic, and histopathologic characteristics of an oncocytoma of the conjunctiva are described. A 49-year-old woman presented with a red-orange lesion adjacent to the caruncle in her left eye. A clinical examination including high-frequency ultrasound was performed prior to excisional biopsy of her tumor. High-frequency ultrasound demonstrated an epibulbar tumor with low internal reflectivity and a cystic component. There was no involvement of the underlying sclera. Multiple hypoechoic components of the tumor stroma were correlated to multiple cystic glandular structures on histopathologic evaluation. The excised tumor was diagnosed to be an oncocytoma.     

Differential effects of chronic ethanol feeding on cytochrome P-448- and P-450-mediated drug metabolism in the rat

The effects of chronic ethanol feeding on cytochrome P-448- and P-450-mediated drug metabolism have been studied both in vivo and in vitro in the rat, using caffeine, phenacetin, antipyrine and aminopyrine as test substrates. N-Demethylation of aminopyrine (P-450 mediated) was increased both in vivo and in vitro in rats after chronic ethanol feeding (P < 0.05) whereas in vivoN-demethylation of caffeine and O-dealkylation of phenacetin (P-448 mediated) were unchanged in the same animals. N-rmDemethylation of antipyrine was increased by both phenobarbital and 3-methylcholanthrene pretreatment and by chronic ethanol feeding (P < 0.05), possibly due to cytochrome P-450 induction. Furthermore, the Michaelis affinity constants. K_m, for hepatic microsomal aminopyrine N-demethylase and antipyrine N-demethylase were lower in chronic ethanol-fed animals (P < 0.05), suggesting a qualitative change in the enzymes resulting in greater substrate affinity. These findings suggest a differential effect of chronic ethanol feeding on the induction of cytochrome P-450- and cytochrome P-448-mediated drug metabolism, with a greater effect on the former microsomal system.     

Prophylactic dexamethasone for postoperative nausea and vomiting in pediatric strabismus surgery: a dose ranging and safety evaluation study

In this double-blind, randomized, placebo-controlled study, we evaluated the efficacy and safety of different doses of prophylactic IV dexamethasone for postoperative nausea and vomiting (PONV) in 168 children (aged 2-15 yr) scheduled for strabismus surgery. Patients received IV dexamethasone 0.25 mg/kg (D 0.25), 0.5 mg/kg (D 0.5), 1.0 mg/kg (D 1), or saline (S) immediately after induction of general anesthesia. Patients were discharged 24 h after surgery. Nausea and vomiting were assessed at 0-2, 2-6, and 6-24 h after surgery. Blood glucose was measured preoperatively and at 4 h after study drug administration. Wound healing and infection were assessed after 1 wk. More patients in group S had vomiting at 0-2, 2-6, and 6-24 h (P = 0.001, P = 0.003, and P = 0.04, respectively) and required larger doses of rescue antiemetics compared with the dexamethasone groups. Fewer patients in the dexamethasone groups (6, 3, and 6 in D 0.25, D 0.5, and D 1, respectively) had severe PONV compared with group S (P = 0.001). No significant increase in postoperative blood glucose levels was observed and wound healing was satisfactory in all four groups. The results suggest that dexamethasone 0.25 mg/kg is more effective than saline and equally effective compared with larger doses for preventing PONV for pediatric strabismus surgery.     

Vitamin D and bone mineral density status of healthy schoolchildren in northern India

BACKGROUND: Current data on the prevalence of vitamin D deficiency in India are scarce. OBJECTIVE: We assessed the calcium-vitamin D-parathyroid hormone axis in apparently healthy children from 2 different socioeconomic backgrounds in New Delhi, India. DESIGN: Clinical evaluation for evidence of vitamin D deficiency was carried out in 5137 apparently healthy schoolchildren, aged 10-18 y, attending lower (LSES) and upper (USES) socioeconomic status schools. Serum calcium, inorganic phosphorus, alkaline phosphatase, 25-hydroxyvitamin D [25(OH)D], and immunoreactive parathyroid hormone were measured in 760 children randomly selected from the larger cohort. Bone mineral density of the forearm and the calcaneum was measured in 555 children by using peripheral dual-energy X-ray absorptiometry. RESULTS: Clinical evidence of vitamin D deficiency was noted in 10.8% of the children. Children in the LSES group had a significantly (P < 0.01) lower 25(OH)D concentration (10.4 +/- 0.4 ng/mL) than did those in the USES group (13.7 +/- 0.4 ng/mL). Concentrations of 25(OH)D <9 ng/mL were seen in 35.7% of the children (42.3% in LSES; 27% in USES; P < 0.01). Boys had significantly (P = 0.004) higher 25(OH)D concentrations than did girls. There was a significant negative correlation between the mean serum immunoreactive parathyroid hormone and 25(OH) D concentrations (r = -0.202, P < 0.001). Mean forearm bone mineral density was significantly (P < 0.01) higher in the USES group than in the LSES group. CONCLUSION: A high prevalence of clinical and biochemical hypovitaminosis D exists in apparently healthy schoolchildren in northern India.     

Unsafe abortion: a neglected tragedy. Review from a tertiary care hospital in India

AIM: With 16% of the world's population, India accounts for over 20% of the world's maternal deaths. The maternal mortality ratio, defined as the number of maternal deaths per 100 000 live births is incredibly high at 408 per 100 000 live births for the country. Abortion has been legalized in India for the past three decades. However, the share of unsafe abortion as a cause of maternal mortality continues to be alarming. The objective of the present study is to identify the magnitude of problem of unsafe abortion in India. METHODS: Emergency gynecologic admissions to a tertiary care center in North India over a 15-year period (1988-2002) were reviewed to evaluate the demographic and clinical profile of patients admitted as a result of unsafe abortion. The records were analyzed with regard to the age group, parity and marital status of the abortion seekers, the indication of abortion, the methods used, qualification of abortion providers, complications and fatality rate. RESULTS: The majority of women who were admitted with diagnosis of unsafe abortion were in the third decade of their lives. They were married, multiparous women living with their spouses. Sixty percent of the women had approached unqualified abortion providers who used primitive methods of pregnancy termination. All the women were admitted with serious complications of unsafe abortions and one-fourth of them succumbed to the complications. CONCLUSION: Unsafe abortion constitutes a major threat to the health and lives of women. This study highlights the need to focus more directly on the needs and preferences of women who seek abortion as well as on the accessibility of contraceptives and skills of the providers of abortion services, in order to improve the quality of abortion care.