Vasopressin stimulation of acetate incorporation into lipids in a dimethylbenz(a)anthracene-induced rat mammary tumor cell line.
(1/15793)
In a preliminary report we described the effects of rat prolactin on the incorporation of [14C]acetate into lipids by a cell line from a dimethylbenz(a)anthracene-induced rat mammary tumor. The characteristics of the response to prolactin were very similar to those described for the normal rat mammary gland; namely, insulin was required for full expression of the response, maximal activity was not seen until 36 hr after the addition of the hormones, and growth hormone was able to elicit the same response. However, we were unable to detect binding of 125I-labeled prolactin to these cells, and furthermore, other more purified prolactin preparations were inactive. Upon further investigation we discovered that the activity resided in a low-molecular-weight fraction of the rat prolactin B-1 preparation and was probably either vasopressin or oxytocin or both. These data suggest the possibility that vasopressin may play a role in rodent mammary tumorigenesis. (+info)
Cardiovascular disease in insulin dependent diabetes mellitus: similar rates but different risk factors in the US compared with Europe.
(2/15793)
BACKGROUND: Cardiovascular disease (CVD) in insulin dependent diabetes mellitus (IDDM) has been linked to renal disease. However, little is known concerning international variation in the correlations with hyperglycaemia and standard CVD risk factors. METHODS: A cross-sectional comparison was made of prevalence rates and risk factor associations in two large studies of IDDM subjects: the Pittsburgh Epidemiology of Diabetes Complications Study (EDC) and the EURODIAB IDDM Complications Study from 31 centres in Europe. Subgroups of each were chosen to be comparable by age and duration of diabetes. The EDC population comprises 286 men (mean duration 20.1 years) and 281 women (mean duration 19.9 years); EURODIAB 608 men (mean duration 18.1 years) and 607 women (mean duration 18.9 years). The mean age of both populations was 28 years. Cardiovascular disease was defined by a past medical history of myocardial infarction, angina, and/or the Minnesota ECG codes (1.1-1.3, 4.1-4.3, 5.1-5.3, 7.1). RESULTS: Overall prevalence of CVD was similar in the two populations (i.e. men 8.6% versus 8.0%, women 7.4% versus 8.5%, EURODIAB versus EDC respectively), although EDC women had a higher prevalence of angina (3.9% versus 0.5%, P < 0.001). Multivariate modelling suggests that glycaemic control (HbA1c) is not related to CVD in men. Age and high density lipoprotein cholesterol predict CVD in EURODIAB, while triglycerides and hypertension predict CVD in EDC. For women in both populations, age and hypertension (or renal disease) are independent predictors. HbA1c is also an independent predictor-inversely in EURODIAB women (P < 0.008) and positively in EDC women (P = 0.03). Renal disease was more strongly linked to CVD in EDC than in EURODIAB. CONCLUSIONS: Despite a similar prevalence of CVD, risk factor associations appear to differ in the two study populations. Glycaemic control (HbA1c) does not show a consistent or strong relationship to CVD. (+info)
The PRIME study: classical risk factors do not explain the severalfold differences in risk of coronary heart disease between France and Northern Ireland. Prospective Epidemiological Study of Myocardial Infarction.
(3/15793)
We are studying the contribution of risk and genetic factors, and their interaction, to the development of ischaemic heart disease (IHD) and other cardiovascular endpoints. The study is prospective, based in three centres in the south, east and north of France and in Northern Ireland. A total of 10,592 men aged 50-59 years were recruited from 1991 to 1993, and examined for evidence of IHD at baseline. Subjects are followed annually by questionnaire. Clinical information is validated from hospital and GP records. Demographic characteristics were similar in all four centres. Body mass index was highest in Strasbourg (mean 27.4 kg/m2 vs. 26.3 kg/m2 in Toulouse and Belfast), but total cholesterol, triglyceride and fibrinogen were highest in Belfast. In Belfast, 6.1% reported having had a coronary angiogram, compared to 3.0% in Toulouse. Conversely, 13.8% in Toulouse reported taking lipid-lowering drugs vs. 1.6% in Belfast. As predicted, a history of myocardial infarction (MI) was highest in Belfast (6.1%) and lowest in Toulouse (1.2%). Some 7.1% of Belfast men reported a medical diagnosis of angina vs. 1.5% in Toulouse. Subjects showing evidence of pre-existing IHD will be studied prospectively but treated in the analysis as an additional variable. These results provide a measure of reassurance that these cohorts are representative of the communities from which they are drawn and provide a reliable baseline for prospective evaluation and cross-sectional comparisons. The levels of the classical risk factors found in this study, particularly when examined in combination, as multiple logistic functions based on previous British studies, are very similar between centres and cannot explain the large differences in the incidence of IHD which exist. Additional risk factors may help explain, at least in part, the major differences in incidence of IHD between these study centres. (+info)
Chlamydia pneumoniae antibodies are associated with an atherogenic lipid profile.
(4/15793)
OBJECTIVE: To determine, within a representative population group of men and women, whether alteration of the lipid profile might underlie the reported association between Chlamydia pneumoniae and ischaemic heart disease. DESIGN AND SETTING: Cross sectional survey in an area with a high incidence of ischaemic heart disease. SUBJECTS: 400 randomly selected participants in the World Health Organisation MONICA project's third population survey in Northern Ireland. MAIN OUTCOME MEASURES: Stored sera were examined by microimmunofluorescence for IgG antibodies to C pneumoniae at a dilution of 1 in 64. Mean total and high density lipoprotein (HDL) cholesterol were compared between seropositive and seronegative individuals with adjustment for age, measures of socioeconomic status, smoking habit, alcohol consumption, body mass index, and the season during which blood had been taken. RESULTS: In seropositive men, adjusted mean serum total cholesterol and HDL cholesterol were 0.5 mmol/l (9.2%) higher and 0.11 mmol/l (9.3%) lower, respectively, than in seronegative men. Differences in women did not achieve statistical significance, but both total cholesterol and HDL cholesterol were higher (3.6% and 5.8%, respectively) in seropositive than in seronegative individuals. CONCLUSIONS: There is serological evidence that C pneumoniae infection is associated with an atherogenic lipid profile in men. Altered lipid levels may underlie the association between C pneumoniae and ischaemic heart disease. (+info)
Suppression of atherosclerotic development in Watanabe heritable hyperlipidemic rabbits treated with an oral antiallergic drug, tranilast.
(5/15793)
BACKGROUND: Inflammatory and immunological responses of vascular cells have been shown to play a significant role in the progression of atheromatous formation. Tranilast [N-(3,4-dimethoxycinnamoyl) anthranillic acid] inhibits release of cytokines and chemical mediators from various cells, including macrophages, leading to suppression of inflammatory and immunological responses. This study tested whether tranilast may suppress atheromatous formation in Watanabe heritable hyperlipidemic (WHHL) rabbits. METHODS AND RESULTS: WHHL rabbits (2 months old) were given either 300 mg x kg-1 x d-1 of tranilast (Tranilast, n=12) or vehicle (Control, n=13) PO for 6 months. Tranilast treatment was found to suppress the aortic area covered with plaque. Immunohistochemical analysis showed that there was no difference in the percentage of the RAM11-positive macrophage area and the frequency of CD5-positive cells (T cells) in intimal plaques between Tranilast and Control. Major histocompatibility complex (MHC) class II expression in macrophages and interleukin-2 (IL-2) receptor expression in T cells, as markers of the immunological activation in these cells, was suppressed in atheromatous plaque by tranilast treatment. Flow cytometry analysis of isolated human and rabbit peripheral blood mononuclear cells showed that an increase in expression both of MHC class II antigen on monocytes by incubation with interferon-gamma and of IL-2 receptor on T cells by IL-2 was suppressed by the combined incubation with tranilast. CONCLUSIONS: The results indicate that tranilast suppresses atherosclerotic development partly through direct inhibition of immunological activation of monocytes/macrophages and T cells in the atheromatous plaque. (+info)
Proposal to transfer Halococcus turkmenicus, Halobacterium trapanicum JCM 9743 and strain GSL-11 to Haloterrigena turkmenica gen. nov., comb. nov.
(6/15793)
The 16S rRNA gene sequences of Halococcus saccharolyticus and Halococcus salifodinae were closely related (94.5-94.7% similarity) to that of Halococcus morrhuae, the type species of the genus Halococcus. However, Halococcus turkmenicus was distinct from the other members of this genus, with low 16S rRNA similarities when compared to Halococcus morrhuae (88.7%). On the basis of phylogenetic tree reconstruction, detection of signature bases and DNA-DNA hybridization data, it is proposed to transfer Halococcus turkmenicus to a novel genus, Haloterrigena, as Haloterrigena turkmenica gen. nov., comb. nov., and to accommodate Halobacterium trapanicum JCM 9743 and strain GSL-11 in the same species. On the basis of morphological, cultural and 16S rRNA sequence data, it is also proposed that the culture collection strains of Halobacterium trapanicum NCIMB 767, ATCC 43102 and JCM 8979 should be renamed as Halococcus sp. (+info)
Reclassification of Methanogenium tationis and Methanogenium liminatans as Methanofollis tationis gen. nov., comb. nov. and Methanofollis liminatans comb. nov. and description of a new strain of Methanofollis liminatans.
(7/15793)
Sequencing of 16S rRNA genes and phylogenetic analysis of Methanogenium tationis DSM 2702T (OCM 43T) (T = type strain) and Methanogenium liminatans GKZPZT (= DSM 4140T) as well as other members of the family Methanomicrobiaceae revealed that both species belong to a separate line of descent within this family. In addition, a new strain of Methanogenium liminatans, strain BM1 (= DSM 10196), was isolated from a butyrate-degrading, fluidized bed reactor and characterized. Cells of both species are mesophilic, highly irregular cocci that use H2/CO2 and formate for growth and methanogenesis. In addition, Methanogenium liminatans strains GKZPZT and BM1 used 2-propanol/CO2, 2-butanol/CO2 and cyclopentanol/CO2. Both species contained diether and tetraether lipids. The polar lipids comprised amino-phosphopentanetetrol derivatives, which appear to be characteristic lipids within the family Methanomicrobiaceae. The pattern of glycolipids, phosphoglycolipids and amino-phosphoglycolipids was consistent with the assignment of these two species to a taxon within the family Methanomicrobiaceae, but also permitted them to be distinguished from other higher taxa within this family. The G+C contents of the DNA of Methanogenium tationis and Methanogenium liminatans were 54 and 60 mol% (Tm and HPLC), respectively. On the basis of the data presented, the transfer of Methanogenium tationis and Methanogenium liminatans to the genus Methanofollis gen. nov. as Methanofollis tationis comb. nov. and Methanofollis liminatans comb. nov., respectively, is proposed, with Methanofollis tationis as the type species. (+info)
Characterization of two novel haloalkaliphilic archaea Natronorubrum bangense gen. nov., sp. nov. and Natronorubrum tibetense gen. nov., sp. nov.
(8/15793)
Two haloalkaliphilic archaea were isolated from a soda lake in Tibet. The two strains, designated A33T and GA33T, were Gram-negative, pleomorphic, flat, non-motile and strictly aerobic. Growth required at least 12% NaCl. Growth was between pH 8.0 and pH 11 with an optimum at pH 9.0-9.5. Cells were chemo-organotrophic. Polar lipids were C20-C25 derivatives of phosphatidylglycerol and phosphatidylglycerol phosphate. The nucleotide sequences of the 16S rRNA genes from the two strains were obtained by the analysis of the cloned rDNAs. On 16S rRNA phylogenetic trees, the two strains formed a monophyletic cluster. They differed from their closet neighbours, Halobacterium trapanicum and Natrialba asiatica, in polar lipid composition, as well as physiological and phenotypic characteristics. DNA-DNA hybridization indicated that the two strains belonged to different species of the same genus. The results indicated that the strains A33T and GA33T should be classified in a new genus Natronorubrum gen. nov. as Natronorubrum bangense sp. nov. (strain A33T) and Natronorubrum tibetense sp. nov. (strain GA33T). (+info)