DAT1 VNTR allele frequencies in the Omani population

To determine the genetic variability at the human DAT1 VNTR locus, we screened 110 healthy Omani blood donors using the polymerase chain reaction (PCR) and agarose gel electrophoresis. Two common alleles (DAT1*9 and DAT1*10) were observed with a frequency of 0.332 and 0.609, respectively. There were also five rare alleles (*3, *6, *7, *8, and *11). The frequency of the observed genotypes was not significantly different from the expected Hardy-Weinberg distribution. We compared the Omani DAT1 alleles with similar data from other populations.     

The VNTR polymorphism in the human dopamine transporter gene: improved detection and absence of association of VNTR alleles with attention-deficit hyperactivity disorder

The human dopamine transporter (DAT1) gene contains a variable number tandem repeat (VNTR) in its 3'-untranslated region because of repetition of a 40-bp core sequence. Methods available for the diagnosis of this polymorphism are limited in number. We have developed a new polymerase chain reaction (PCR) test, which is similar to that described originally by Vandenbergh's group, but provides a better detection of the VNTR alleles in the human DAT1 gene. Using two independent PCR methods, we have determined the distribution of VNTR alleles in 110 healthy Omani subjects, and in 92 children with attention-deficit hyperactivity disorder (ADHD). The frequency of the risk allele (DAT1*10) was similar in the healthy subjects and ADHD cases, indicating absence of association of this allele with ADHD in Oman.     

Inhibition of Na+, K+-ATPase activates swelling-induced taurine efflux in a human neuroblastoma cell line

The Na⁺ pump (Na⁺, K⁺-ATPase) has been implicated in the regulation of many cellular functions, including cell volume regulation. The effects of inhibiting Na⁺ pump activity on cell volume and taurine efflux were evaluated in the human neuroblastoma cell line CHP-100. Cell volume changes monitored with the Coulter Multisizer technique and confocal microscopy showed that neuroblastoma cells exposed to ouabain swelled by 22 ± 4% (n = 5). The rapid cell swelling was followed by regulatory volume decrease (RVD). In cells treated with ouabain, ¹⁴C-taurine efflux increased by 183 ± 11% compared with controls. However, cells exposed simultaneously to ouabain and hypoosmotic solution resulted in a ¹⁴C-taurine efflux of 207 ± 18%. Western blot and immunofluorescence microscopy with specific monoclonal antibodies for the catalytic α isoforms of Na⁺, K⁺-ATPase demonstrated high levels of the ubiquitously expressed α1 and the neuronal-specific α3. Ouabain-binding data showed that CHP-100 cells express ∼3 × 10⁵ pump units/cell. The present data indicate that efflux of taurine may be involved during volume recovery subsequent to blockade of Na⁺, K⁺-ATPase in CHP-100 cells. J. Cell. Physiol. 174:145–153, 1998. © 1998 Wiley-Liss, Inc.     

Correction to: Dietary Supplementation of Walnut Partially Reverses 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine Induced Neurodegeneration in a Mouse Model of Parkinson’s Disease

Neurochemical Research - The original version of this article unfortunately contains an error in Fig. 2a (4th image for walnut). This has been corrected by publishing this erratum.     

Differential Gag-specific polyfunctional T cell maturation patterns in HIV-1 elite controllers

A small fraction of HIV-infected individuals (<1%), referred to as elite controllers (EC), are able to maintain undetectable viral loads indefinitely without treatment. The role of the maturational phenotype of T cells in the control of HIV infection in these individuals is not well described. We compared the maturational and functional phenotypes of Gag-specific CD4 and CD8 T cells from EC, who maintain undetectable viral loads without treatment; relative controllers (RC), who maintain viral loads of <1,000 copies/ml without treatment; and noncontrollers (NC), who fail to control viral replication. EC maintained higher frequencies of HIV-specific CD4 T cells, less mature polyfunctional Gag-specific CD4 T cells (CD27(+) CD57(-) CD45RO(+)), and Gag-specific polyfunctional CD4 T cells than those observed in NC. In EC, the frequency of polyfunctional Gag-specific CD8 T cells was higher than that observed in RC and NC. RC had a similar functional phenotype to that observed in NC, despite consistently lower viral loads. Finally, we found a direct correlation between the frequency of Gag-specific CD27(+) CD57(-) CD45RO(+) CD4(+) T cells and the frequency of mature HIV-specific CD8 T cells. Altogether, our data suggest that immature Gag-specific interleukin-2 (IL-2)-producing CD4(+) T cells may play an important role in spontaneous control of HIV viremia by effectively supporting HIV-specific CD8 T lymphocytes. This difference appears to differentiate EC from RC.     

Long-Term Dietary Supplementation of Pomegranates,Figs and Dates Alleviate Neuroinflammation in a Transgenic Mouse Model of Alzheimer’s Disease

Alzheimer’s disease (AD) is a devastating age-related neurodegenerative disease with no specific treatment at present. The APPsw/Tg2576 mice exhibit age-related deterioration in memory and learning as well as amyloid-beta (Aβ) accumulation, and this mouse strain is considered an effective model for studying the mechanism of accelerated brain aging and senescence. The present study was aimed to investigate the beneficial effects of dietary supplements pomegranate, figs, or the dates on suppressing inflammatory cytokines in APPsw/Tg2576 mice. Changes in the plasma cytokines and Aβ, ATP, and inflammatory cytokines were investigated in the brain of transgenic mice. Significantly enhanced levels of inflammatory cytokines IL-1β, IL-2, IL-3, IL-4, IL-5, IL-6, IL-9, IL-10, TNF-α and Eotaxin activity were decreased by administration of the diet supplements containing pomegranates, figs, or dates. In addition, putative delays in the formation of senile plaques, as indicated by a decreasing tendency of brain Aβ1–40 and Aβ1–42 contents, were observed. Thus, novel results mediated by reducing inflammatory cytokines during aging may represent one mechanism by which these supplements exert their beneficial effects against neurodegenerative diseases such as AD.     

Liver and kidney toxicity induced by Afzal smokeless tobacco product in Oman

Afzal, the common smokeless tobacco product (STP) in Oman, is believed to contain toxins that may impair the function of some organs such as liver and kidney. An aqueous extract from Afzal was added to drinking water to be administrated orally to Wistar albino rats (n = 72) young and adult from both genders weighing between 60–80 g and 150–240 g respectively for 8 weeks. Animals were divided into three groups: control (distilled water instead of Afzal extract), low-dose (3 mg nicotine/kg body weight/day) and high-dose (6 mg nicotine/kg body weight/day). The animals were euthanized and their blood, liver and kidney were collected for biochemical and histopathological investigations. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were assayed for the liver function, while blood urea nitrogen (BUN) and creatinine (CRT) were assayed for the kidney function. The results showed a significant increase in the ALT, AST, BUN and CRT levels (P < 0.05) in both Afzal-treated groups (low and high doses) compared with the control. Histopathological findings revealed the initial but seem to be serious degenerative alterations of periportal fibrosis in liver and edematous and calcified changes in renal glomerulus among Afzal-treated groups. Additionally, the weight gain of the Afzal-treated groups was lower than the control group. Our findings show that the exposure of Wistar rats to the Afzal extract has the potentials of causing decreased weight gain and dose-dependent functional and structural damage to the biochemical and histological profiles of liver and kidney as well as serious biochemical effects.     

What can isothermal titration microcalorimetry experiments tell us about the self‐organization of surfactants into micelles?

The aim of the present review is to give a concise analysis of the thermodynamic parameters obtained from isothermal titration microcalorimetry (ITC) experiments for the characterization of the self‐organization of surfactants into micelles. This review is also focused on works describing some methods allowing to overcome ITC limitation and to extract accurate thermodynamic values from ITC data. Copyright © 2009 John Wiley & Sons, Ltd.     

Levels of Heavy Metals and Essential Minerals in Hair Samples of Children with Autism in Oman: a Case–Control Study

Toxic levels of heavy metals and low levels of essential minerals have been suggested to play a critical role in the pathogenesis of autism spectrum disorders (ASD). This study documents the levels of heavy metals and essential minerals in hair samples of children with ASD in Muscat, the urbanized capital of Oman, Muscat. The study included 27 children with ASD and 27 matched non-ASD controls. Parental interviews were held and dietary intake questionnaires completed in conjunction with the collection of hair samples. Analysis of heavy metals and essential minerals was carried out by inductively coupled plasma mass spectrometry. Chi-square analysis and non-parametric Fisher’s exact tests were used to assess statistical significance. Children with ASD had significantly higher levels of all 11 analyzed heavy metals in their hair samples (P?<?0.05), ranging from 150 to 365 % of control levels. ASD children also had significantly higher levels of essential minerals sulfur, sodium, magnesium, potassium, zinc, and iron, but lower levels of calcium and copper in their hair samples. This study corroborates data from previous studies in different parts of the world indicating the presence of elevated levels of heavy metals and selective depletion of essential minerals in the hair of children with ASD.