Serum DHEA-S levels could be used as a comparable diagnostic test to assess the pubertal growth spurt in dentofacial orthopedics.

BACKGROUND: Pubertal growth spurt assessment guides the timing of intervention for correcting the skeletal discrepancies in dentofacial orthopedics. Serum hormones are being studied for the skeletal age assessment to avoid unnecessary radiographic exposure. The present study is to evaluate the relationship of serum hormones dehydroepiandrosterone-sulfate (DHEA-S), insulin-like growth factor (IGF-1), and cervical vertebral stages (CS stages) in the skeletal age assessment of orthodontics patients around the circumpubertal age. METHODS: A total of ninety subjects with age ranging from 7 to 21 years were selected and divided into two groups based on the sex (45 males, 45 females). They were further distributed in each group based on the six CS stages determined from the lateral cephalogram. Blood samples from each subject were collected to evaluate the serum DHEA-S and IGF-1 levels by using the enzyme-linked immunosorbent assay (ELISA). Collected data were analyzed in SPSS software with a test of normalcy, unpaired t test, and one-way analysis of variance (ANOVA) followed by the least significant difference (LSD) post hoc comparison test and univariate regression analysis. RESULTS: The highest mean serum hormone levels were found in CS 4 in group A (male) and CS 3 in group B (female). ANOVA results showed that there was a significant difference in the serum hormone levels among the different CS stages in both the groups for both the hormones. Statistically, a significant difference was found between each CS stages for both the hormones except in the DHEA-S levels between CS 5 and CS 6. CONCLUSIONS: The mean serum DHEA-S levels followed a typical pattern from the CS 1 till CS 6 which was comparable and similar to the mean serum IGF-1 levels in respect to CS stages. Thus, serum DHEA-S levels could be used as a possible diagnostic test for the assessment of the skeletal pubertal growth spurt in dentofacial orthopedics.

A Prospective Clinical Study of a Prosexual Nutrient: Nano Leo for Evaluation of Libido, Erection, and Orgasm in Indian Men with Erectile Dysfunction.

AIM: The present study aimed to assess the effects of Nano Leo, a prosexual nutrient formulation, on libido, erection, and orgasm in patients with erectile dysfunction (ED). METHODS: This was a prospective, single-center, phase IV efficacy study. Patients received two capsules for 7 days and thereafter one capsule through 90 days. Main outcome measures: primary endpoint was change in erectile function assessed using the International Index of Erectile Function (IIEF) questionnaire. Secondary endpoints included improvement in testosterone levels, FSH, LH, and prolactin levels; seminal parameters; and overall quality of life (QoL). RESULTS: Our study included 99 men (mean age 32.2 ± 4.71 years). Mean erectile function domain score increased from 18.9 ± 5.67 at baseline to 23.7 ± 4.01 on day 90 (P < 0.001). Similar improvements were observed in orgasmic function, sexual desire, intercourse satisfaction, and overall satisfaction domains of IIEF score which was seen as early as day 30. Improved IIEF corroborated with improvement in all QoL domains. From baseline to day 90, treatment with Nano Leo increased testosterone levels (5.04 ± 2.22 vs. 5.57 ± 1.53 ng/mL, P < 0.001). Similar improvements were observed in orgasmic function, sexual desire, intercourse satisfaction, and overall satisfaction domains of IIEF score which was seen as early as day 30. Improved IIEF corroborated with improvement in all QoL domains. From baseline to day 90, treatment with Nano Leo increased testosterone levels (5.04 ± 2.22 vs. 5.57 ± 1.53 ng/mL. CONCLUSION: Nano Leo showed improved libido, erection, and orgasm as evaluated by IIEF and QoL and was well tolerated. Therefore, Nano Leo could be an effective and safe pronutrient supplement in managing ED.

Combinatorial effect of curcumin and tumor necrosis factor-α-related apoptosis-inducing ligand (TRAIL) in induction of apoptosis via inhibition of nuclear factor kappa activity and enhancement of caspase-3 activity in chronic myeloid cells: An In-vitro study.

BACKGROUND: Nuclear factor kappa B (NFkB-light-chain-enhancer of activated B-cells) expression and its regulation is a key role in the development of number of malignancies, as NFkB mediates the balance between cell death and its survival. Therefore, NFkB regulation constitutes an attractive target to overcome the resistance to chemotherapeutic agents in anticancer therapy. Curcumin, as a chemopreventive agent, has a potential role in inhibiting cell growth in a variety of malignancies. Thus, this study was aimed to investigate the efficacy of curcumin along with tumor necrosis factor-α-related apoptosis-inducing ligand (TRAIL) in KCL-22 myeloid cells along with an investigation of the mechanism by which both the agents exert their effects. MATERIALS AND METHODS: KCL-22 cells were exposed to different doses of curcumin and TRAIL alone and in combination. Cell viability was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, caspase activity by fluorescent method, protein expression by western Blot, and NFkB activity by electrophoretic mobility shift assays, respectively. RESULTS: Cell viability assay revealed that when both the agents, curcumin and TRAIL, were used together, there was reduced cell viability in dose- and time-dependent manner as compared to each agent alone. Curcumin and TRAIL enhanced the caspase-3 activity as compared to caspase-8 and caspase-9. Both the agents induced apoptosis in KCL-22 cells by suppressing the IκB kinase and NFkB activity. CONCLUSION: Our results conclude that curcumin and TRAIL effectively induce the apoptosis through the inhibition of NFkB activity and by enhancing the caspase-3 activity. Thus, curcumin may prove as a potent inhibitor of NFkB by representing its role in cancer pathogenesis, especially in chronic myeloid leukemia cells.

Assessment of liver function in pregnant anemic women upon oral iron and folic acid supplementation.

Oral iron therapy is the most widely prescribed treatment for iron deficiency anemia. However, oral iron supplementation may also lead to various health problems. The recognition of these physiological variations is essential for the diagnosis of liver diseases during the course of pregnancy. Therefore, the objective of this study was to assess the variations in levels of routine liver function tests (LFTs) in pregnant women before and after iron and folic acid treatment. Iron and folic acid was supplemented to 500 normal pregnant anemic women (mild=200, moderate=200 and severe=100) and 100 age matched normal pregnant non-anemic as controls daily for 100 days. Blood index values and liver function parameters were precisely monitored. Hemoglobin (Hb), total protein (TP), iron (Fe), albumin and alkaline phosphatase (ALP) levels were found increased (P<0.001; P<0.01; P<0.05) after treatment in mild, moderate, severe and control, respectively. Lipid peroxidation (LPx), aspartate transaminase (AST) and alanine transaminase (ALT) were increased in pretreated mild, moderate and severe groups and further increased after all treated subjects. Moreover, gamma-glutamyl transpeptidase (GGT) was found to decrease in pre and posttreated subjects. Treatment with iron and folic acid although has remarkable efficacy for Hb and body iron stores although for the cost of increasing the associated compartment of total bilirubin, AST and ALT concomitant with decreased GGT levels. Data obtained from the present study provide new insights into the mandatory application of liver function tests likely to be monitored at regular and specific intervals during the course of pregnancy.

Leptin as a Predictive Marker in Unexplained Infertility in North Indian Population.

INTRODUCTION: According to WHO, the primary infertility in India is about 3.9% (age-standardized to 25-49 year) and 16.8% (age-standardized to 15-49 year), using the "age but no birth" definition. Several factors which affect fertility include low sperm production in men, poor egg quality and blocked fallopian tubes in women and also hormonal imbalances. Leptin plays a critical role in women's reproduction and neuroendocrine health. It is used for treating exercise-induced bone loss, eating disorders and infertility. AIM: To evaluate the serum leptin levels in Indians and to ascertain the relationship between serum leptin levels, Unexplained Infertility (UI) and related variables [height, weight, Waist Hip Ratio (WHR), Body Mass Index (BMI)] between obese infertile, non-obese infertile and healthy subjects. MATERIALS AND METHODS: The present case-control study was conducted at the Department of Obstetrics and Gynaecology, King George's Medical University (KGMU), Lucknow, India and funded by Department of Science and Technology, New Delhi, India. The study included 229 female participants in the age group of 18-40 years (120 cases and 109 controls) who were randomly selected. The blood samples were collected from the Infertility Clinic, Queen Mary's Hospital, KGMU, Lucknow, India. All the participants underwent complete physical examination. Initially, the participants were categorized into fertile and infertile groups, they were further divided on the basis of BMI, normal (BMI- 18.5-24.5) and overweight or obese (BMI≥25). Leptin level was measured by Active Human Leptin ELISA kit and BMI of all subjects was calculated in kg/m2 (weight in kg and height in m). RESULTS: A highly positive linear correlation (R=0.754, p<0.001) was found between BMI and serum leptin in unexplained infertile women, which indicates a strong relationship between BMI and serum leptin. The variation in serum leptin is explained by the independent variable, BMI. There was a partial positive linear correlation between BMI and serum leptin in the control group. Statistically there was no significant correlation (R=0.109, p=0.258) between BMI and serum leptin in the control group. CONCLUSION: The present study clearly demonstrates that level of leptin is higher in unexplained infertile than in the fertile group, and also shows that a strong relationship exists between BMI and serum leptin in the obese group. Serum leptin level was significantly higher in obese than non-obese subjects. Thus, leptin is an important factor for normal reproductive function. Obesity, the main cause of infertility may be controlled by regulating the leptin concentration.

Oxidative stress and antioxidative parameters in patients with spinal cord injury: implications in the pathogenesis of disease.

STUDY DESIGN: Oxygen-derived free radicals have been implicated in the pathogenesis of spinal cord injury (SCI) after trauma. OBJECTIVE: In this review we will elucidate the importance of oxidative stress and antioxidants and its possible relationship with SCI. METHODS: Literature analysis of oxidative stress, antioxidative parameters based on its implications in the pathogenesis along with devastating effect of oxidative stress parameters on SCI patients and its suggested proposed treatment by antioxidants have been performed. RESULTS: SCI remains a major health problem despite advances in neurotechnology. Previous studies have reported oxidative stress in SCI patients, but the results were inconsistent. Furthermore, increased free radical levels are reported in SCI. Moreover, we have also mentioned in this review that oxidative stress is supposed to be increased in patients with SCI, which is related to the severity of SCI pain. CONCLUSION: Oxidative stress was commonly seen in SCI patients, which may provide useful information to augment the understanding of pathophysiology of SCI patients. However, complete understanding of the biochemical events occurring at a cellular level that influence oxidative damage is required to guide future therapeutic advances. Furthermore, supplementation of antioxidants may also be considered in these patients.

Antioxidant and anticancer activities of selected persian gulf algae.

In the present study, the effect of red (Gracillaria corticata), green (Ulva fasciata) and brown (Sargassum ilicifolium) seaweeds alcoholic extract, against five important human cancer cell lines (MCF-7, MDA-MB-231, HeLa, HepG2, and HT-29) proliferation, apoptosis and cell cycle arrest were evaluated. The reducing activity and total polyphenol content were also investigated. MTT assay was used for cytotoxicity test. Morphological alterations were examined using phase contrast, fluorescent and electron microscopy. All the extracts were antiproliferative against all the cancer cell lines, dose-dependently, with G. corticata methanol extract (GCME) having the greatest inhibition activity against MCF-7 cell line. The percentage of apoptosis increased from 18 to 78 %. The cell cycle analysis also showed that GCME can induce apoptosis which confirm by TEM. Algal extract reducing activities were as follows: G. corticata > S. ilicifolium > U. fasciata. The GCME is a good source of potential complementary and alternative functional food for prevention and treatment of cancer.

Biochemical alteration of hepatic functions by histamine H3-receptor agonist and antagonist in immunized rabbits.

AIM: The aim of our study was to investigate the functional roles of H3R agonist and antagonist in the development of hepatic functions impairment in immunized rabbits. METHODS: The study comprised of six groups containing 18 rabbits in each. Group-I (negative control) and group-II (positive control) received sterile distilled water intramuscularly while Group III-VI received histamine (100 µgkg-1, s.c.), R-[-]-α-methylhistamine (H3R-agonist, 10 µgkg-1, s.c.), iodophenpropit (H3R-antagonist, 1 µgkg-1, i.m.), and the combination of iodophenpropit (1 µgkg-1, i.m.) plus histamine (100 µgkg-1, s.c.), respectively, b.i.d. (12 hours [8 am and 8 pm]) for 10 days. Groups II-VI were immunized on day 3 with intravenous injection of sheep red blood cells (1×109 cells/ml). RESULTS: On each experimental day, the mean values of serum enzymes and bilirubin in group-I and group-II showed no changes while in groups III, IV, V, and VI, these enzymes and bilirubin levels showed significant changes (p<0.05), when compared with their values within the group. Profile of ALT and AST production revealed that ALT and AST levels moderately were changed due to degeneration of the liver. CONCLUSION: Our results suggest that R-[-]-α-methylhistamine showed moderate, and histamine and iodophenpropit showed mild degeneration of liver functions; while iodophenpropit plus histamine showed hepatic functions similar to control group. This study suggests that H3R antagonist in combination with histamine may be a non-toxic therapeutic target for histamine research (Fig. 7, Ref. 28). Text in PDF www.elis.sk.

TIGAR induces p53-mediated cell-cycle arrest by regulation of RB-E2F1 complex.

BACKGROUND: p53 induces cell-cycle arrest and apoptosis in cancer cells and negatively regulates glycolysis via TIGAR. Glycolysis is crucial for cancer progression although TIGAR provides protection from reactive oxygen species and apoptosis. The relation between TIGAR-mediated inhibition of glycolysis and p53 tumour-suppressor activity is unknown. METHODS: RT-PCR, western blot, luciferase and chromatin immunoprecipitation assays were used to study TIGAR gene regulation. Co-IPP was used to determine the role of TIGAR protein in regulating the protein-protein interaction between retinoblastoma (RB) and E2F1. MCF-7 tumour xenografts were utilised to study the role of TIGAR in tumour regression. RESULTS: Our study shows that TIGAR promotes p21-independent, p53-mediated G1-phase arrest in cancer cells. p53 activates the TIGAR promoter only in cells exposed to repairable doses of stress. TIGAR regulates the expression of genes involved in cell-cycle progression; suppresses synthesis of CDK-2, CDK-4, CDK-6, Cyclin D, Cyclin E and promotes de-phosphorylation of RB protein. RB de-phosphorylation stabilises the complex between RB and E2F1 thus inhibiting the entry of cell cycle from G1 phase to S phase. CONCLUSION: TIGAR mediates de-phosphorylation of RB and stabilisation of RB-E2F1 complex thus delaying the entry of cells in S phase of the cell cycle. Thus, TIGAR inhibits proliferation of cancer cells and increases drug-mediated tumour regression by promoting p53-mediated cell-cycle arrest.

NMR-based metabonomics study of sub-acute hepatotoxicity induced by silica nanoparticles in rats after intranasal exposure.

Silica nanoparticles (SiO(2) NPs) are widely used commercially; however, their potential toxicity on human health has attracted particular attention. In the present study, the intranasal toxicological effect of 10nm and 80nm SiO(2) NPs (dosed at 150µg for 90 days) on rats was investigated using conventional approaches and metabonomics analysis of serum. Oxidative stress was measured by assessing Lipid peroxide (LPO) levels and enzymatic activities of Superoxide dismutase (SOD), Catalase (CAT), and Glutathione (GSH) levels in liver tissue homogenate. These biochemical observations were supplemented by histological examination of liver sections. SiO(2) NPs enhanced lipid peroxidation with concomitant reduction in SOD, CAT, and GSH content. In addition, SiO(2) NPs also produced alterations in hepatic histopathology. We also evaluated the effect of SiO(2) NPs on the activities of hepatic enzymes such as aminotransferases (ALT/AST) and alkaline phosphatase (ALP) which revealed significant increase in their activity when compared with control. Metabonomic profile of 90 days SiO(2) NPs treated rat sera exhibited significant increase in lactate, alanine, acetate, creatine and choline coupled with a considerable decrease in glucose level. These perturbations, on the whole, implicate impairment in tricarboxylic acid cycle and liver metabolism, which suggests that silica nanoparticles may have a potential to induce hepatotoxicity in rats.

Association of salivary cortisol with chronomics of 24 hours ambulatory blood pressure/heart rate among night shift workers.

Recent studies indicate a circadian rhythm in blood pressure and heart rate and its association with various neurotransmitters. In the present study, we examine the circadian nature of blood pressure/heart rate and salivary cortisol in night shift workers and whether these circadian changes produced by night shifts are reversible. Sixteen healthy nurses of both genders, aged 20-40 years, performing day and night shift duties, were randomly selected out of 22 who volunteered for this study. Ambulatory blood pressure monitoring was done in all the subjects and salivary cortisol levels were analyzed during both day and night shift duties. There were clinically significant changes in the Acrophase of blood pressure and cortisol levels, indicating ecphasia (odd timing of systolic blood pressure) individually during night as well as day shifts. However, this pattern was statistically not significant. A reverse pattern of Acrophase was observed in 8 out of 16 subjects when they were posted on day shift. No significant change was found in midline estimating statistics of rhythm (MESOR) of blood pressure values. Changes in Double amplitude (Predictable change) were observed in 8 subjects during night shifts as well as in 7 subjects during day shifts. However, the pattern was not similar and night workers had an altered circadian pattern in the night as well as during day shifts. Changes in Double amplitude, Acrophase and Salivary cortisol were found during night as well as day shifts but these changes were not statistically significant (p > 0.05) due to incomplete recovery during day shifts (changes again seen when they came back to day shifts). Salivary cortisol levels were lowest in early morning, increased at midnight and further increased in the afternoon during night shifts along with ecphasia. It is possible that nurses working the night shift felt more tired due to the altered circadian cycle.

Protective potential of Bacopa monniera (Brahmi) extract on aluminum induced cerebellar toxicity and associated neuromuscular status in aged rats.

The present study attempts to assess the comparative effects of Bacopa monniera, (40 mg/kg body weight) and donepezil (2.5 mg/kg b. wt) on aluminum (100 mg / kg b. wt. of AlCl3) mediated oxidative damage in the cerebellum of aged rats (24 months) along with the associated dysfunctioning of neuromuscular coordination and motor activity. A significant decrease in the activities of antioxidant enzymes and increased total reacting oxygen species, lipid and protein peroxidation products observed in aluminum exposed rats. We observed that treatment with B. monniera extract restored the altered antioxidant enzyme activities more, when compared with donepezil. However, acetylcholinesterase showed similar effect both in donepezil and B. monniera treated groups. The content of aluminum was increased in all experimental groups, however, iron content was found increased in all groups except the B. monniera treated groups. Moreover, aluminum treated groups of rats exhibited significant changes in behavioral profiles but these changes were in both B. monniera and donepezil treated groups. The light microscopic and ultrastructural studies revealed damaged Purkinje's neurons and altered granular cell layer along with the increased accumulation of lipofuscin granules in aluminum treated animals. These changes were quite less pronounced in B. monniera group than that of donepezil and this may be due to the reduction of excess iron content by B. monniera. On the basis of our results it may be concluded that Al may be linked with cerebellar degeneration and neuromuscular disorders while Bacopa monniera extract helps in reversing these changes.

Assessment of association of exposure to polycyclic aromatic hydrocarbons with bronchial asthma and oxidative stress in children: A case control study.

BACKGROUND: Polycyclic aromatic hydrocarbons (PAH) originate from the incomplete combustion of organic matter and ambient air pollution by these is increasing. There is also an increase in the global prevalence of asthma, for which environmental pollution has been recognized as one of the important factors. Exposure to pollutants and other allergens induces chronic airway inflammation by generation of reactive oxygen species, causing oxidative stress. Therefore, the objective of the present study was to assess association, if any, between exposure to PAH and asthma as well as oxidative stress in children. METHOD: In this hospital-based case control study, cases of bronchial asthma aged 1-14 years and healthy matched controls were included. Oxidative stress was measured by assessing the levels of enzymes catalase, superoxide dismutase, malondialdehyde (MDA), and reduced glutathione (GSH). RESULTS: Forty-two cases and 20 controls were enrolled. Mean blood level of phenanthrene, a PAH, was 63.11 ppb +/- 115.62 and 4.20 ppb +/- 10.68 ppb in cases and controls, respectively (P = 0.02). Mean blood levels of GSH was significantly lower in cases and controls (27.39 mug/ml +/- 11.09 versus 47.39 g/ml +/- 13.83; P-value = 0.001). Likewise, mean blood level of MDA in nanomole/ml was significantly higher in asthma as compared with controls (12.85 +/- 5.40 versus 8.19 +/- 5.16; P-value = 0.002), suggestive of increased oxidative stress. CONCLUSIONS: Because elevated blood level of phenanthrene is associated with bronchial asthma as well as with oxidative stress, measures to reduce exposure to PAH may possibly lead to reduced incidence and severity of bronchial asthma.

1H NMR spectroscopy in the diagnosis of Klebsiella pneumoniae-induced urinary tract infection.

The (1)H NMR spectroscopic method is suggested and its utility is demonstrated for the diagnosis of Klebsiella pneumoniae (K. pneumoniae) in urinary tract infection (UTI). K. pneumoniae have the specific property of metabolizing glycerol to 1,3-propanediol (1,3-PD), acetate, ethanol and succinate. The quantity of 1,3-PD produced correlates well with the viable bacterial count. Other common bacteria causing UTI (except for Citrobacter frundii), such as Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa), Enterobacter aerogenes, Acinetobacter baumanii, Proteus mirabilis, Enterococcus faecalis, Streptococcus gp B and Staphylococcus aureus do not metabolize glycerol under similar conditions. Citrobacter frundii (C. frundii) also gives the same NMR results but is easily differentiated as being motile on direct microscopic examination of urine and it is not common nosocomial infectious agent in urinary tract infection. The method provides a single-step documentation of K. pneumoniae (and C. frundii) qualitatively as well as quantitatively. Out of the total 614 subjects considered, clinical diagnosis of UTI was obtained in 516 cases (84%). The NMR-based screening had a sensitivity of 90%, a specificity of 100% and a false negativity of 10% relative to the conventional quantitative culture method. In the present authors' experience, the results of NMR spectroscopy based screening show a very good correlation with the diagnosis of urinary tract infected patients.

(1)H NMR spectroscopy in the diagnosis of Pseudomonas aeruginosa-induced urinary tract infection.

The utility of (1)H NMR spectroscopy is suggested and demonstrated for the diagnosis of Pseudomonas aeruginosa in urinary tract infection (UTI). The specific property of P. aeruginosa of metabolizing nicotinic acid to 6-hydroxynicotinic acid (6-OHNA) is exploited. The quantity of 6-OHNA produced correlates well with the viable bacterial count. Other common bacteria causing UTI such as Escherichia coli, Klebsiella pneumonia, Enterobacter aerogenes, Acinetobacter baumanii, Proteus mirabilis, Citrobacter frundii, Enterococcus faecalis, Streptococcus gp B and Staphylococcus aureus do not metabolize nicotinic acid under similar conditions. The method provides a single-step documentation of P. aeruginosa qualitatively as well as quantitatively. The NMR method is demonstrated on urine samples from 30 patients with UTI caused by P. aeruginosa.

Circadian periodicity of plasma lipid peroxides and other anti-oxidants as putative markers in gynecological malignancies.

BACKGROUND: The chronome (from chronos, time, and nomos, rule), or time structure, of lipid peroxidation and anti-oxidant defense mechanisms may relate to prevention and curative chronochemotherapeutic efficacy and management. PATIENTS AND METHODS: Newly diagnosed women with gynecological malignancies (N = 30), 30-60 years of age, and age-matched clinically healthy women (N = 35) provided blood samples every 6 hours for 24 hours under standardized conditions. Plasma malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR) activities, and serum ascorbate, urate and high-density lipoprotein cholesterol (HDL-C) concentrations were determined. RESULTS: Each variable underwent circadian variation (p < or = 0.002). Patients differed from controls by their overall chronome-adjusted mean value (MESOR) and by the circadian dynamics in the spectral element of their chronome. CONCLUSION: Chronomes of putative anti- and pro-oxidants should be mapped to explore their putative chemotherapeutic role as markers in cancer chronoprevention and management of established disease.

Characterisation of the catalytically active form of RecG helicase.

Replication of DNA is fraught with difficulty and chromosomes contain many lesions which may block movement of the replicative machinery. However, several mechanisms to overcome such problems are beginning to emerge from studies with Escherichia coli. An important enzyme in one or more of these mechanisms is the RecG helicase, which may target stalled replication forks to generate a four-stranded (Holliday) junction, thus facilitating repair and/or bypass of the original lesion. To begin to understand how RecG might catalyse regression of fork structures, we have analysed what the catalytically active form of the enzyme may be. We have found that RecG exists as a monomer in solution as measured by gel filtration but when bound to junction DNA the enzyme forms two distinct protein-DNA complexes that contain one and two protein molecules. However, mutant inhibition studies failed to provide any evidence that RecG acts as a multimer in vitro. Additionally, there was no evidence for cooperativity in the junction DNA-stimulated hydrolysis of ATP. These data suggest that RecG functions as a monomer to unwind junction DNA, which supports an 'inchworm' rather than an 'active rolling' mechanism of DNA unwinding. The observed in vivo inhibition of wild-type RecG by mutant forms of the enzyme was attributed to occlusion of the DNA target and correlates with the very low abundance of replication forks within an E.COLI: cell, even during rapid growth.

Circadian periodicity of urinary volume, creatinine and 5-hydroxyindole acetic acid excretion in healthy Indians.

The circadian periodicity of urinary output, creatinine (Cr) and 5-hydroxyindole acetic acid (5-HIAA) excretion was studied under near-tropical conditions in 130 healthy volunteers (65 men and 65 women, 16-75 years of age) with a diurnal activity from about 06:30 to about 22:00 and nocturnal rest. These volunteers were divided into 4 groups, 16-30, 31-45, 46-60 and 61-75 years of age, comprising 20, 20, 15 and 10 participants of each gender, respectively. A marked circadian rhythm was recorded for urine volume, Cr and 5-HIAA excretion in healthy Indians of different ages. The acrophase tended to be delayed in the older age group. The relative amplitude decreased with advancing age, notably in women. Overall, men produced a larger urine volume as compared to women. Excretions of Cr and 5-HIAA in healthy Indian volunteers of different ages may be influenced by diet, societal relations, climate and/or geographic location. The contribution of such factors in metabolism and degradation warrants further study.

Studies on circadian periodicity of urinary corticoids in carcinoma of the breast.

The circadian periodicity of urinary 17-ketogenic steroids (17-KGS), 17-ketosteroids (17-KS) and creatinine (Cr) was studied preoperatively and on the 9th postoperative day in 25 histopathologically proved breast cancer patients and in 15 healthy Indian women under tropical conditions. A statistically significant rhythm was observed in healthy participants for all three variables. Urinary corticoids were markedly elevated in breast cancer patients irrespective of the stage of the disease in comparison with healthy controls. The degree of elevation was more pronounced preoperatively in advanced stage breast cancer in comparison with other groups. After mastectomy, the values of all three variables declined markedly, approaching usual values with a circadian rhythm resembling the pattern found in clinical health.

DNA binding and helicase domains of the Escherichia coli recombination protein RecG.

The Escherichia coli RecG protein is a unique junction-specific helicase involved in DNA repair and recombination. The C-terminus of RecG contains motifs conserved throughout a wide range of DNA and RNA helicases and it is thought that this C-terminal half of RecG contains the helicase active site. However, the regions of RecG which confer junction DNA specificity are unknown. To begin to assign structure-function relationships within RecG, a series of N- and C-terminal deletions have been engineered into the protein, together with an N-terminal histidine tag fusion peptide for purification purposes. Junction DNA binding, unwinding and ATP hydrolysis were disrupted by mutagenesis of the N-terminus. In contrast, C-terminal deletions moderately reduced junction DNA binding but almost abolished unwinding. These data suggest that the C-terminus does contain the helicase active site whereas the N-terminus confers junction DNA specificity.