Fluoride-induced immunotoxicity in adult male albino rat: a correlative approach to oxidative stress

Fluoride pollution in drinking water is an international problem as the fluoride present is often at levels above acceptable limits. In the studies reported here, sodium fluoride (NaF) treatment of rats by gavage for 28 days resulted in the induction of oxidative stress and immunotoxicity. It was shown here that NaF treatment lowered cellular immunity in the rats as illustrated by a significant diminution in peripheral blood lymphocyte, monocyte and neutrophil counts in conjunction with a reduction in splenocyte counts. Effects of NaF treatment on humoral immunity were reflected here in a lowering of the levels of plasma IgG specific to a test antigen (i.e., bovine serum albumin). Disorganization in the histoarchitecture was also noted in the host spleen and thymus after NaF treatment. To determine if oxidative stress was among the potential possible causes for the observed induced immunotoxicities, catalase and peroxidase activities along with malondialdehyde (MDA, product of free radical damage to cells) levels in the spleen and peripheral blood packed cells were also measured. The results indicated that there was a significant diminution in the activities of both the enzymes along with an elevation in MDA levels in both the tissues in treated rats. This report highlights the proposition that chronic exposure to fluoride contaminated drinking water is likely to result in immunotoxicity and, furthermore, that the damage to primary immune organs is due to an induction of oxidative stress.

An improved model averaging scheme for logistic regression

Recently, penalized regression methods have attracted much attention in the statistical literature. In this article, we argue that such methods can be improved for the purposes of prediction by utilizing model averaging ideas. We propose a new algorithm that combines penalized regression with model averaging for improved prediction. We also discuss the issue of model selection versus model averaging and propose a diagnostic based on the notion of generalized degrees of freedom. The proposed methods are studied using both simulated and real data.

Successful management in neglected cases of adult anorectal malformation

Posterior sagittal anorectoplasty (PSARP) is the procedure of choice in cases of anorectal malformation in children. Adult patients can present with anorectal malformation in developing countries. As there is very little data regarding the success of PSARP in cases of adult anorectal malformations, the aim of this study was to perform and assess the effectiveness of PSARP in adults. Two adults (one male, one female) aged 16 and 17 years, respectively, underwent a diverting colostomy followed by a PSARP. The female underwent a posterior vaginal anorectoplasty due to a rectovaginal fistula and is leading a normal life. The male patient had a rectourethral fistula which required meticulous dissection and is now doing well with a Kelly's score of five. Our experience here suggests that a PSARP provided satisfactory results in adults who present late with an anorectal malformation.

A systems biology approach towards understanding the process of blastocyst implantation

Time-synchronous development of endometrium and embryo under adequate progesterone dominance is considered integral to the process of blastocyst implantation in the human. It now appears that hypothesis-driven and candidate-based deductive approach fails to explain this complex control process. We propose a systems biology approach to elucidate the control process underlying the physiological basis of successful interfacing between embryo and endometrium towards blastocyst implantation. Elucidation of the time course pattern of transcriptomics involved in the process of blastocyst implantation in mid-luteal phase endometrium with and without progesterone dominance, as well as, with and without viable embryo shall elaborate upon the polygenic and multifactorial nature of the process of blastocyst implantation. Accordingly, a large scale homeodynamic model of hierarchical arrangement of functional networks of regulatory genomic expressional elements at the level of endometrial receptivity shall emerge. It is anticipated that such a systems biology approach shall provide an integrated picture of the process and shall also open up novel areas of basic, strategic and translational research in the biology of blastocyst implantation.

A comparative study of different graft materials used in myringoplasty

Two hundred twenty cases of unilateral chronic suppurative otitis media (CSOM) with dry central perforation were chosen for this study and myringoplasty were done. Age group ranged from 13 to 48 years. Four types of autogenous tissues were used as graft material. Grafting was done by underlay technique when temporalis fascia, tragal perichondrium, areolar tissue were used as graft material and when fat graft was used the ear lobule fat was placed directly into perforation through transcanal route. Postoperative follow-up was carried out up to 6 months. In this study, it was found that the younger age group has less impairment of hearing and better chance of tympanic membrane perforation closure than the older age group in CSOM with central perforation. Anterior perforations has less impairment of hearing and better result in successful closure of tympanic membrane than posterior perforation group. It was also observed that larger the size of perforation greater is the hearing impairment preoperatively and postoperative hearing gain is also less compared to small perforation. Best hearing improvement occurred using temporalis fascia. Failure occurred may be due to postoperative infection, respiratory tract infection, neglected post-operative advice etc.

Effect of low-dose mifepristone administration on day 2 after ovulation on transcript profiles in implantation-stage endometrium of rhesus monkeys

Progesterone is essential for endometrial receptivity in primates. In studies previously performed using global gene profiling based on microarray technology, attempts have been made to identify changes in gene expression between early luteal-phase and mid-luteal-phase endometria. However, the issue of the putative impact of preimplantation embryo-derived signal in the process of endometrial receptivity was missing in the previous studies. In the present study, an attempt has been made to delineate the transcripts profile in implantation-stage endometrium under combinatorial regulation of progesterone and embryo-derived signal in the rhesus monkey. To this effect, we have compared transcript profiles for 409 known genes between control receptive stage (n=13), and mifepristone-induced desynchronized and non-receptive stage (n=12) monkey endometrial samples collected on days 4 (n=12) and 6 (n=13) after ovulation from mated, potential conception cycles, using cDNA arrays containing sequence-verified clones. Statistical analysis of correlation of estimated transcript abundance between arrays and qRT-PCR for nine selected gene products yielded significant (P<0.05) concordance. Of 409 genes, a total of 40 gene transcripts were seen to be affected, nine gene transcripts in endometrial samples were found to progressively increase between days 4 and 6 following mifepristone treatment, while an additional five genes showed differential expression profile depending on the day after treatment. Additionally, different sets of 12 and 14 gene products showed changes in days 4 and 6 post-ovulation samples respectively. A new cohort of 28 gene products in implantation-stage endometrium was seen to be affected by luteal-phase mifepristone.

Vascular action of polyphenols

Dietary patterns are widely recognised as contributors to cardiovascular and cerebrovascular disease. Endothelial function, the elastic properties of large arteries and the magnitude and timing of wave reflections are important determinants of cardiovascular performance. Several epidemiological studies suggest that the regular consumption of foods and beverages rich in flavonoids is associated with a reduction in the risk of several pathological conditions ranging from hypertension to coronary heart disease, stroke and dementia. The impairment of endothelial function is directly related to ageing and an association between decreased cerebral perfusion and dementia has been shown to exist. Cerebral blood flow (CBF) must be maintained to ensure a constant delivery of oxygen and glucose as well as the removal of waste products. Increasing blood flow is one potential way for improving brain function and the prospect for increasing CBF with dietary polyphenols is extremely promising. The major polyphenols shown to have some of these effects in humans are primarily from cocoa, wine, grape seed, berries, tea, tomatoes (polyphenolics and nonpolyphenolics), soy and pomegranate. There has been a significant paradigm shift in polyphenol research during the last decade. This review summarises our current knowledge in this area and points the way for the development of new types of functional foods targeted to brain health through improving vascular health.

Future perspectives of nutrigenomics foods: benefits vs. risks

Nutrigenomics, defined as the application of high-throughput genomics tools in nutrition research is now past its incubation phase. The poorly understood associations of diet and disease prevention in particular will likely be the single most important catalyst to its accelerated and continued growth. Whether the goal of matching foods to individual genotypes to improve the health of those individuals can be attained, and personalised nutrigenomic foods enter the world's food markets, depends on numerous hurdles being overcome: some scientific in nature, some' technical and others related to consumer, market or ethical issues. Public adoption of new technologies is an important determinant for their success. Many of the drivers behind the trend in personalisation of food are now known, particularly ethical, legal, and social issues (ELSI) are the major drivers. Future development in the field of nutrigenomics undoubtedly will place its seemingly huge potential in better perspective. From the scientific responsibility point of view, one hopes that the new perspectives to be gained and progress to be made in this field will be so managed as to take the public at large on board, if we are to avoid another nutrition education disaster of the genetically modified organism type and dimension.

Fasting total homocysteine (tHcy) concentration and mortality in older Mexican Americans

OBJECTIVES

This study examines the association between tHcy on cardiovascular and noncardiovascular mortality.

DESIGN

Longitudinal study of 1,633 Mexican Americans age>60 years recruited in 1998.

SETTING

Sacramento, California.

MEASUREMENTS

Cox proportional models were used to estimate the effects of tHcy on mortality rate in the total sample and in a subgroup of subjects without a history of cardiovascular disease at baseline.

RESULTS

About half of the cohort was born in Mexico. Among Mexican-born participants, high tHcy (>11.0 micromol/L) was associated with a higher rate of cardiovascular mortality compared to those with low tHcy concentration

CONCLUSIONS

The effect of tHcy on cardiovascular mortality is nearly 40% stronger among the immigrant group. tHcy might be an early marker of subclinical vascular pathology amongst the Mexican-born group, despite their apparently healthy profile at baseline.

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Key Words

• homocysteine
• cardiovascular mortality
• mexican americans
• nutritional biomarkers
• elderly

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MESH Headings

• Aged
• Aged, 80 and over
• Biomarkers/blood
• California/epidemiology
• Cardiovascular Diseases/ethnology
• Cardiovascular Diseases/mortality
• Female
• Homocysteine/blood
• Humans
• Longitudinal Studies
• Male
• Mexican Americans
• Mexico/ethnology
• Middle Aged
• Proportional Hazards Models

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Grants

• 1R24HD047861 NICHD NIH HHS
• P60 DK20572 NIDDK NIH HHS
• R01 DK060753 NIDDK NIH HHS
• AG12975 NIA NIH HHS
• R24 HD047861 NICHD NIH HHS
• DK60753 NIDDK NIH HHS
• R01 DK060753-03 NIDDK NIH HHS
• R03 AG033751 NIA NIH HHS
• R01 AG012975 NIA NIH HHS
• P60 DK020572-30 NIDDK NIH HHS
• P30 DK092926 NIDDK NIH HHS
• R01 AG012975-11 NIA NIH HHS
• P60 DK020572 NIDDK NIH HHS
• RWJ04823 PHS HHS

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Treatment of fluoride containing drinking water by electrocoagulation using monopolar and bipolar electrode connections

Electrocoagulation was investigated for the effective removal of fluoride from drinking water. Different initial concentrations (2-10 mg L(-1)) of fluoride were considered for the experiment. Two different electrode connections (monopolar and bipolar) were examined for choosing the better alternative in order to intensify the performance of the process. It was observed that the removal of fluoride was better for bipolar connection than for monopolar connection. The final recommendable limit of fluoride (1 mg L(-1)) was obtained in 30 min at 625 Am(-2) using bipolar connection. The corrosion of electrodes as well as the sludge formed during the process was estimated for the bipolar connection. Thickness of film generated on the electrode surfaces in bipolar connection was also estimated at different current densities as well as for different initial fluoride concentrations. By-products obtained from the electrocoagulation bath were analyzed using SEM, EDAX, FTIR and XRD and explained. Comparative cost estimation for both electrode connections was adopted and presented as well. Total operating costs for monopolar and bipolar connections were 0.38 and 0.62 US$ m(-3), respectively, for the initial fluoride concentration of 10 mg L(-1). These findings might be useful in order to treat the fluoride contaminated water for drinking.

Removal of Fe(II) from tap water by electrocoagulation technique

Electrocoagulation (EC) is a promising electrochemical technique for water treatment. In this work electrocoagulation (with aluminum as electrodes) was studied for iron Fe(II) removal from aqueous medium. Different concentration of Fe(II) solution in tap water was considered for the experiment. During EC process, various amorphous aluminum hydroxides complexes with high sorption capacity were formed. The removal of Fe(II) was consisted of two principal steps; (a) oxidation of Fe(II) to Fe(III) and (b) subsequent removal of Fe(III) by the freshly formed aluminum hydroxides complexes by adsorption/surface complexation followed by precipitation. Experiments were carried out with different current densities ranging from 0.01 to 0.04 A/m2. It was observed that the removal of Fe(II) increases with current densities. Inter electrode distance was varied from 0.005 to 0.02 m and was found that least inter electrode distance is suitable in order to achieve higher Fe(II) removal. Other parameters such as conductivity, pH and salt concentration were kept constant as per tap water quality. Satisfactory iron removal of around 99.2% was obtained at the end of 35 min of operation from the initial concentration of 25 mg/L Fe(II). Iron concentration in the solution was determined using Atomic absorption spectrophotometer. By products obtained from the electrocoagulation bath were analyzed by SEM image and corresponding elemental analysis (EDAX). Cost estimation for the electrocoagulation was adopted and explained well. Up to 15 mg/L of initial Fe(II) concentration, the optimum total cost was 6.05 US$/m3. The EC process for removing Fe(II) from tap water is expected to be adaptable for household use.

Molecular mechanism of manganese exposure-induced dopaminergic toxicity

Manganese (Mn) is an essential mineral that is found in varying amounts in aerosols or dust. Exposure to atmospheric Mn at high concentration is a risk factor in humans that can manifest as neuronal degeneration resembling Parkinson's disease (PD). Since the underlying mechanism of Mn and dopamine (DA) interaction-induced cell death remains unclear, here, we showed that Mn exposure alone to mesencephalic cells for 24h induced minimal apoptotic cell death. However, cells pre-exposed to DA for 2h accelerated Mn-induced apoptosis. The vulnerability of Mn-induced apoptotic cell death to DA was determined by measuring lactate dehydrogenase (LDH) and Apoptag TUNEL staining (terminaldeoxynucleotidyl transferase DNA labeling). This was further confirmed by the cell viability assay to support our hypothesis that DA at the cellular level interacts with Mn and causes cells to be more susceptible. Pretreatment with nitric oxide blocker (7-nitroindazole, 7-NI), vitamin E or NF-kappaB inhibitor (SN50) significantly protected the cells from Mn and DA interaction-induced reactive oxygen species (ROS) and apoptosis. Western blot analysis showed that Mn in the presence of DA markedly induced induction of NOS (iNOS) expression. Pretreatment with 7-NI, SN50 or vitamin E significantly attenuated increased iNOS expression indicating that iNOS expression is regulated by ROS and the transcription factor NF-kappaB. Further, the generation of ROS as an early event in Mn and DA interaction is not controlled by NF-kappaB as SN50 pretreatment did not prevent ROS. These findings suggest that NF-kappaB induction and the activation of nitric oxide synthase through ROS represent a proximate mechanism for Mn-induced neurotoxicity.

Role of virulence plasmid of Aeromonas hydrophila in the pathogenesis of ulcerative disease syndrome in Clarias batrachus

Pathogenic Aeromonas hydrophila (strain VB21), a multiple-drug resistance strain contains a plasmid of about 21 kb. After curing of plasmid, the isolates became sensitive to antimicrobials, to which they were earlier resistant. The cured bacteria exhibited significant alterations in their surface structure, growth profile and virulence properties, and failed to cause ulcerative disease syndrome (UDS) when injected into the Indian catfish Clarias batrachus. Routine biochemical studies revealed that the plasmid curing did not alter the biochemical properties of the bacteria. After transformation of the plasmid into cured A. hydrophila the bacterium regained its virulence properties and induced all the characteristic symptoms of UDS when injected into fish. Thus, the plasmid plays a pivotal role in the phenotype, growth and virulence of A. hydrophila and pathogenesis of aeromonad UDS.