Macro-level and genetic-level responses of Bacillus subtilis to shear stress.

Responses of bacterial (Bacillus subtilis) cells under different shear levels, from both the macro and genetic viewpoints, have been presented. The responses were studied using a novel, couette flow bioreactor (CFB), in which the entire cultivation can be performed under defined shear conditions. Oxygen supply, the normal limiting factor for entire cultivations under defined shear conditions, has been achieved by passing air through a poly(tetrafluoroethylene) (PTFE) membrane fixed on the inner cylinder of the CFB.

Lead induced effects on acetylcholinesterase activity in cerebellum and hippocampus of developing rat.

Exposure to low-levels of lead (Pb) during early development has been implicated in behavioral abnormalities and cognitive deficits in children. The present study is focused on developmental changes in hippocampus and cerebellum of rats following perinatal exposure to Pb. Pregnant rats were exposed to 0.

Lead neurotoxicity: heme oxygenase and nitric oxide synthase activities in developing rat brain.

Chronic lead (Pb) exposure has been shown to result in cognitive deficits in children. Diffusible nitric oxide (NO) is a biological messenger known to regulate long-term potentiation (LTP) in the developing nervous system. Carbon monoxide (CO), as in the case of NO was shown to be a messenger molecule in the brain.

A highly conserved human gene encoding a novel member of WD-repeat family of proteins (WDR13).

We have identified and characterized a novel member of the WD-repeat motif gene family, WDR13, which contains 9 exons and 8 introns. The gene has been mapped to the genomic locus Xp11.23 by fluorescent in situ hybridization and in silico mapping.

Overexpression of manganese superoxide dismutase promotes survival in cell lines after doxorubicin treatment.

Overexpression of manganese superoxide dismutase (MnSOD) has been postulated as one possible mechanism of protection from oxidative damage and free radicals. Doxorubicin treatment induces oxygen free radicals, leading to cytotoxicity and myelosuppression. The present study was performed to determine whether over-expression of MnSOD may play a role in resistance to doxorubicin.

Benign thyroid disease and dietary factors in thyroid cancer: a case-control study in Kuwait.

We conducted a population-based study of 313 case-control pairs in Kuwait to examine the aetiology of thyroid cancer, the second most common neoplasm among women in this and several other countries in the Gulf region. Among the demographic variables, individuals with 12+ years of education had a significantly reduced risk of thyroid cancer (OR=0.6; 95% CI: 0.

A new procedure for the spectrophotometric determination of uranium(VI) in the presence of a large excess of thorium(IV).

Spectrophotometric determination of microgram amounts of U(VI) with 2-(5-Bromo-2-Pyridylazo)-5-diethylaminophenol (Br-PADAP), originally developed by Johnson and Florence has been modified to enable the determination of U(VI) in the presence of a large excess of Th(IV). The effects of thorium, tri-n-butyl phosphate (TBP) and ethanol on the estimation of uranium have been studied in detail and are presented in this paper. This modified method can be applied for the analysis of U(VI) both in aqueous and organic samples containing a large excess of Th(IV) (Th:U = 10000:1).

Epidemiology of reproductive and hormonal factors in thyroid cancer: evidence from a case-control study in the Middle East.

Thyroid cancer is the second most common neoplasm among women in Kuwait and several other countries in the Middle East. Most of these countries also have relatively high birth and total fertility rates. To examine potential relationships between reproductive and hormonal factors and thyroid cancer, we conducted a population-based case-control interview study among 238 women diagnosed with thyroid cancer and a similar number of individually matched controls in Kuwait.

Effects of manganese on inositol polyphosphate receptors and nitric oxide synthase activity in rat brain.

The neurotoxic effects of excessive exposure to manganese (Mn) include degeneration of dopaminergic neurons, impairment of energy metabolism, and perturbations in phosphoinositide (PI) hydrolysis leading to altered calcium (Ca2+) homeostasis. This study is designed to assess the in vitro and in vivo effects of Mn on Ca2+/calmodulin-dependent neuronal nitric oxide synthase (nNOS) activity and on the regulation of inositol 1,4,5-trisphosphate (InsP3) and inositol 1,3,4,5-tetrakisphosphate (InsP4) receptors involved in intracellular and extracellular mobilization of Ca2+. In vivo Mn exposure significantly increased 3H-InsP3 and 3H-InsP4 binding in the cerebellum and the cerebral cortex in a dose-dependent manner.

Incidence of hip fracture in Kuwait.

Background: Hip fracture as a consequence of osteoporosis is an important cause of morbidity and mortality among the elderly. Due to improving life expectancy, the number of elderly individuals is increasing more rapidly in the developing countries of Asia, the Middle East, Africa, and South America. Incidence of hip fracture, which rises exponentially with age, varies substantially between countries and according to the age, sex, and ethnic distribution of the population.

Changes in protein metabolism in hemolymph and fat body of the silkworm, Bombyx mori (Lepidoptera: Bombycidae) in response to organophosphorus insecticides toxicity.

Changes in protein metabolism were studied in hemolymph and fat body of 5th instar silkworm Bombyx mori exposed to lethal and sublethal doses of fenitrothion and ethion. The total protein content indicated a depletion followed by a concomitant increase in accumulation of free amino acids. Concurrently, the activity of protease in both of the tissues was also increased.

Quantitation of resistance to cytosine arabinoside by myeloid leukemic cells expressing bcl-2.

The presence of bcl-2 in myeloid leukemias has been associated with a decrease in therapy-induced apoptosis, reduced patient survival and in vitro autonomous growth of leukemic cells. The present study focuses on the quantitation of resistance to increasing doses of 1-beta-d-arabinofuranosylcytosine (Ara-C) by using hematological tumors expressing different levels of bcl-2. Scanning densitometry of Western blots demonstrated that the myeloid U-937 cells express low levels of bcl-2 (RD = 0.

Evaluation of some acylamide derivatives as potential hypoglycemic agents.

A series of new acylamide derivatives with piperidine, pyrrolidinyl and alanyl have been tested for their hypoglycemic activities. 2-(Pyrrolidynyl)-N-(3-chlorophenyl) acetamide and 2-(Piperazinyl)-N-(4-methoxy phenyl) acetamide were found most active hypoglycemic compounds. Probably the amides have mode of action similar to sulphonylureas.

Immunological and metabolic effects of prophylactic insulin therapy in the NOD-scid/scid adoptive transfer model of IDDM.

Prophylactic insulin therapy prevents IDDM in spontaneous animal models of the disease and has shown promise in preventing the disease in humans. Although large clinical trials have been formed to use this therapy, a comparative analysis of the efficiency of different pharmaceutical forms and doses of insulin in preventing IDDM has not been performed, and the mechanism underlying the observed prevention of disease is unknown. In the NOD-scid/scid adoptive transfer model of IDDM (10(7) new-onset NOD splenocytes injected intravenously into 6- to 8-week NOD/scid-scid recipients; insulitis develops at 6-9 days post-transfer and 100% IDDM by 32 days post-transfer), life-table (log-rank) analyses revealed that IDDM can be delayed (compared with insulin-free diluent, once daily, n = 8) with equivalent efficiency by prophylactic administration (-9-50 days post-transfer) of high (metabolism-altering) doses of short-acting (0.

Overexpression of the human aldehyde dehydrogenase class I results in increased resistance to 4-hydroperoxycyclophosphamide.

A correlation between overexpression of aldehyde dehydrogenase and resistance to oxazaphosphorines, widely used anticancer agents, has been shown. To investigate the direct role of the human aldehyde dehydrogenase class 1 (ALDH-1) in the resistance to one of these agents, 4-hydroperoxycyclophosphamide (4-HC), an active metabolite of cyclophosphamide, neomycin-selectable plasmid or retroviral constructs harboring the wild-type ALDH-1 complementary DNA in the sense orientation were transfected into K562 leukemic cell lines. Polymerase chain reaction (PCR) analysis confirmed the presence of vector DNA in the stably transfected K562 cells.

Protective effects of human interleukin-1 on hematopoietic progenitor cells from L-phenylalanine mustard.

The effects of interleukin-1 (IL-1) on protecting both human and murine bone marrow cells were studied using in vitro clonogenic assays, long-term bone marrow cultures and in vivo mouse studies. Incubation with 100 ng/ml human recombinant IL-1 beta for 20 hours prior to a one hour exposure to L-phenylalanine mustard (L-PAM) provided significant protection of bone marrow colony forming cells when compared to bone marrow cells not exposed to IL-1. Complete inhibition of colony formation was observed above 40 mu M L-PAM in the absence of IL-1 preincubation; whereas, colonies were still detectable in cultures which were initiated with IL-1-treated bone marrow cells.

Pesticidal impact on the protein metabolism of freshwater field crab, Oziotelphusa senex senex (Fabricius).

The total protein increased in the gills and decreased in the muscle of the freshwater field crab Oziotelphusa senex senex at days 1 and 2 on exposure to lethal concentrations and at days 1 and 10 to sublethal concentrations of furadan, endosulfan, chlorpyrifos, and a mixture of these three in a 100:10:1 ratio. The increase in the gill protein was greater on exposure to the sublethal concentrations than to the lethal concentrations while the decrease in the muscle protein was greater on exposure to the lethal concentrations than to the sublethal concentrations. In the hepatopancreas, the protein content decreased on exposure to the lethal concentrations, but, in contrast, increased on exposure to the sublethal concentrations.

Role of manganese superoxide dismutase in radioprotection using gene transfer studies.

Overexpression of manganese superoxide dismutase (MnSOD) has been postulated as one possible mechanism of radioprotection for hematopoietic cells. In this study retroviral constructs having the human MnSOD gene in both the sense and antisense orientations and the Neo-R gene as a selectable marker were transfected into the human erythroleukemic cell line K562 and the human melanoma cell line A375 by electroporation. Stably transfected K562 and A375 cells selected in G418 for 3 weeks were subjected to various doses of irradiation, and cell viability was assayed using a colony assay system in semisolid medium.

Radioprotection of hematopoietic stem cells by interleukin-1.

Radioprotective agents such as interleukin-1 (IL-1) and tumor necrosis factor (TNF-alpha), when given prior to irradiation, protect animals from radiation damage. However, in vivo administration of these cytokines does not allow one to determine whether the protective effects act directly on the hematopoietic system. In the present study, we subjected male bone marrow cells to in vitro treatment with IL-1 prior to irradiation and bone marrow transplantation.

Effect of interferon-gamma, tumor necrosis factor, interleukin-1 and interleukin-6 on the modulation of anti-tumor responses of bone marrow derived macrophages.

Non-adherent bone marrow cells (NABMC) obtained from BALB/c mice were incubated in medium alone or containing granulocyte--macrophage-colony stimulating factor(GM-CSF) or macrophage-colony stimulating factor (M-CSF) for 4 days to obtain bone marrow derived macrophages. Treatment of GM-CSF or M-CSF derived macrophages with interferon-gamma (IFN-gamma) (50 U/ml), tumor necrosis factor (TNF) (500 U/ml), interleukin-1 (IL-1) (200 U/ml) or interleukin-6 (IL-6) (100 U/ml) for 24 h rendered them significantly cytotoxic to different tumor cells. These macrophages also produced enhanced amounts of soluble or membrane associated TNF.