Central fat accretion and insulin sensitivity: differential relationships in parous and nulliparous women.

BACKGROUND/OBJECTIVES: Childbearing is associated with a disproportionate accumulation of visceral fat and an increased risk of metabolic disease. However, it is unknown whether the visceral fat accretion associated with pregnancy modifies a woman's risk for metabolic disease. The purpose of this study was to test whether the association between abdominal fat and insulin sensitivity differs by parity status in healthy overweight women. SUBJECTS/METHODS: Intra-abdominal adipose tissue (IAAT) via CT, body composition by DXA, insulin sensitivity via intravenous glucose tolerance test and minimal model (SI), HOMA-IR, and cardiorespiratory fitness (VO2max) were assessed in 212 non-diabetic, premenopausal, overweight non-Hispanic white and African-American women. RESULTS: Nulliparous women (n=98) were younger, had less IAAT and higher VO2max, but similar SI, HOMA-IR and leg fat, compared to parous (n=114). In nulliparous women, IAAT was negatively associated with SI, controlling for age, race and body fat mass (r=-0.40, P<0.001), but this relationship was attenuated in parous women (r=-0.15, P=0.16). In multiple linear regression analysis, leg fat and IAAT were significant predictors of SI in nulliparous, but not parous women. CONCLUSIONS: Results suggest that greater IAAT in parous women does not lead to greater insulin resistance; rather, transient insulin resistance during pregnancy may encourage intra-abdominal fat accumulation that is metabolically benign. This underscores the need to consider parity when assessing cardiometabolic risk.

Genome-wide association studies identify genetic loci for low von Willebrand factor levels.

Low von Willebrand factor (VWF) levels are associated with bleeding symptoms and are a diagnostic criterion for von Willebrand disease, the most common inherited bleeding disorder. To date, it is unclear which genetic loci are associated with reduced VWF levels. Therefore, we conducted a meta-analysis of genome-wide association studies to identify genetic loci associated with low VWF levels. For this meta-analysis, we included 31 149 participants of European ancestry from 11 community-based studies. From all participants, VWF antigen (VWF:Ag) measurements and genome-wide single-nucleotide polymorphism (SNP) scans were available. Each study conducted analyses using logistic regression of SNPs on dichotomized VWF:Ag measures (lowest 5% for blood group O and non-O) with an additive genetic model adjusted for age and sex. An inverse-variance weighted meta-analysis was performed for VWF:Ag levels. A total of 97 SNPs exceeded the genome-wide significance threshold of 5 × 10(-8) and comprised five loci on four different chromosomes: 6q24 (smallest P-value 5.8 × 10(-10)), 9q34 (2.4 × 10(-64)), 12p13 (5.3 × 10(-22)), 12q23 (1.2 × 10(-8)) and 13q13 (2.6 × 10(-8)). All loci were within or close to genes, including STXBP5 (Syntaxin Binding Protein 5) (6q24), STAB5 (stabilin-5) (12q23), ABO (9q34), VWF (12p13) and UFM1 (ubiquitin-fold modifier 1) (13q13). Of these, UFM1 has not been previously associated with VWF:Ag levels. Four genes that were previously associated with VWF levels (VWF, ABO, STXBP5 and STAB2) were also associated with low VWF levels, and, in addition, we identified a new gene, UFM1, that is associated with low VWF levels. These findings point to novel mechanisms for the occurrence of low VWF levels.

Altered regional cardiac wall mechanics are associated with differential cardiomyocyte calcium handling due to nebulette mutations in preclinical inherited dilated cardiomyopathy.

Nebulette (NEBL) is a sarcomeric Z-disk protein involved in mechanosensing and force generation via its interaction with actin and tropomyosin-troponin complex. Genetic abnormalities in NEBL lead to dilated cardiomyopathy (DCM) in humans and animal models. The objectives of this study are to determine the earliest preclinical mechanical changes in the myocardium and define underlying molecular mechanisms by which NEBL mutations lead to cardiac dysfunction. We examined cardiac function in 3-month-old non-transgenic (non-Tg) and transgenic (Tg) mice (WT-Tg, G202R-Tg, A592E-Tg) by cardiac magnetic resonance (CMR) imaging. Contractility and calcium transients were measured in isolated cardiomyocytes. A592E-Tg mice exhibited enhanced in vivo twist and untwisting rate compared to control groups. Ex vivo analysis of A592E-Tg cardiomyocytes showed blunted calcium decay response to isoproterenol. CMR imaging of G202R-Tg mice demonstrated reduced torsion compared to non-Tg and WT-Tg, but conserved twist and untwisting rate after correcting for geometric changes. Ex vivo analysis of G202R-Tg cardiomyocytes showed elevated calcium decay at baseline and a conserved contractile response to isoproterenol stress. Protein analysis showed decreased α-actinin and connexin43, and increased cardiac troponin I phosphorylation at baseline in G202R-Tg, providing a molecular mechanism for enhanced ex vivo calcium decay. Ultrastructurally, G202R-Tg cardiomyocytes exhibited increased I-band and sarcomere length, desmosomal separation, and enlarged t-tubules. A592E-Tg cardiomyocytes also showed abnormal ultrastructural changes and desmin downregulation. This study showed distinct effects of NEBL mutations on sarcomere ultrastructure, cellular contractile function, and calcium homeostasis in preclinical DCM in vivo. We suggest that these abnormalities correlate with detectable myocardial wall motion patterns.

Long-term outcome after ECT for catatonic depression.

INTRODUCTION: This is the initial report of the course of major depression with catatonic features after hospitalization. METHOD: Telephone interviews and ratings were conducted 3-7 years after response to inpatient electroconvulsive therapy (ECT) for such catatonic depression. This was done for all 19 followable patients treated over a particular 4-year period. All had received left anterior right temporal brief-pulse ECT. Prior to data examination, we constructed rules to classify medications as antimelancholic. These rules led to the inclusion of lithium, tricyclics, bupropion, and venlafaxine in this antimelancholic classification and to the exclusion of selective serotonin reuptake inhibitors. RESULTS: Ten of the 13 patients discharged on antimelancholic medication (AMM) had good function on follow-up and no more than one rehospitalization. In contrast, none of the six patients in the other group had as good an outcome (p = 0.004, corrected chi2 = 8.26). The AMM group had no deaths, but three patients in the other group died of acute cardiopulmonary causes (p = 0.015). In most cases, catatonia and depression were not identified by informant interview on follow-up. DISCUSSION: ECT followed by AMM usually led to long-term outcome that was good and better than without such medication. Although benzodiazepines can acutely diminish catatonia, we found no relevant long-term study; accordingly, long-term benzodiazepine use in catatonia is speculative.

Cardiac physiology in transgenic mice.

By use of gene targeting and/or transgenesis, it is now possible to make defined changes in genes whose functions underlie mammalian cardiovascular function. Because of technical and economic considerations, these experiments are largely confined to the mouse. Genetic modification of the loci responsible for aspects of cardiac development, differentiation, and function via gene targeting, as well as modulation of the cardiac protein complement using transgenesis, has begun to provide mouse models of cardiac hypertrophy, dilated cardiomyopathy, and hypertrophic cardiomyopathies. In order to use these animal models fully and explore their phenotypes at the whole organ and whole animal levels, the extension of cardiovascular physiological methodologies to the mouse is imperative. Techniques for exploring aspects of cardiovascular function are well developed for larger animal models, but their modification for the small size of the mouse heart and for the animal's rapid cardiac cycle has proven to be a formidable challenge, requiring the combined efforts of the molecular biology, physiology, and cardiology communities. We review here the ability of present-day technology to obtain reproducible data on murine cardiac function at the whole organ and animal levels.

Models of state funding for mental health research.

Twenty-eight of 49 states that responded to a survey supported mental health or substance abuse research through at least one of four funding mechanisms--the joint state-university research unit, research grants, state in-house research, and contracts. The authors illustrate the use of these mechanisms with examples from the states. The events leading to the establishment of the new Oklahoma Mental Health Research Institute are described.

Growth of toxic shock syndrome toxin 1-producing, tryptophan-requiring strains of Staphylococcus aureus associated with the presence of Escherichia coli.

More than 80 percent of TSST-1-positive strains of Staphylococcus aureus are tryptophan auxotrophs (Trp-). Chromosomal mapping has located the genetic determinant for TSST-1 (tst) in the trp operon for strain S411 (Trp-) and near the tyrB site for strain FRI1169 (Trp*). Auxonographic screening on tryptophan-free medium of 28 strains of S. aureus (TSST-1-positive and -negative, Trp+ and Trp-) against Escherichia coli (strains 6094, 7603, and 7877) and other strains of Enterobacteriaceae showed that Trp- S. aureus strains responded only to E. coli and tryptophan. Neither E. coli nor tryptophan inhibited TSST-1 production. Cocultivation of strain FRI1169 or S411 with E. coli strain 7877 showed that TSST-1 production by FRI1169 was not enhanced. In contrast, TSST-1 production by S411 was equal to that of S. aureus alone (less than 640 ng/mL) or enhanced (greater than 12,000 ng/mL) if the input log10 cfu of S. aureus was of equal or greater ratio to input E. coli and if the recovered S. aureus was greater than log10 5 cfu. These results suggest that nutritionally deficient toxicogenic strains of S. aureus may overcome growth limitation by coexisting in dynamic balance with strains of E. coli.

Effect of magnesium on in vitro production of toxic shock syndrome toxin 1.

Batch and chemostat culture of Staphylococcus aureus strain S411 was conducted in an investigation of the role of Mg++ in the control of production of toxic shock syndrome toxin 1 (TSST-1). Under both growth conditions, Mg++ influenced bacterial growth, and TSST-1 production was correlated with bacterial growth. The specific activity of TSST-1 (ng/mg yield, ng/mg total protein) increased with increasing concentrations of Mg++ and was maximal at physiologic levels of Mg++. No production of TSST-1 was observed under anaerobic conditions. In chemostat cultures in which valine nutrient limitation was used with various levels of tryptophan in the chemically defined medium, tryptophan concentration controlled the production of TSST-1 by strain S411, regardless of the concentration of Mg++.

Association of toxic shock toxin-1 determinant with a heterologous insertion at multiple loci in the Staphylococcus aureus chromosome.

Most Staphylococcus aureus strains associated with toxic shock syndrome and producing toxic shock syndrome toxin 1 (TSST-1) require tryptophan because of a genetic defect in tryptophan biosynthesis. The association between TSST-1 production and tryptophan auxotrophy was not correlated with the phage type, the colonization site, or the disease status of the patient from whom the isolate came. Protoplast fusion and transformation mapping located the genetic determinant of TSST-1 production (tst) very close to the trp operon in such strains and very close to tyrB in a Trp+ TSST-1+ strain. Southern blot hybridization of ClaI-restricted chromosomal DNA with a tst-specific probe revealed a common homologous segment in all of the Trp+ strains with tst linked to tyrB. These results confirmed that the tst determinant in Trp- strains is located at one site, whereas in Trp+ TSST-1+ strains the determinant is located elsewhere on the S. aureus chromosome. It is suggested that the TSST-1 determinant is associated with the insertion of a transposonlike segment into several sites on the S. aureus chromosome.

A nitrocellulose membrane based solid phase enzyme immunoassay for detecting polioviruses in stool.

An enzyme immunoassay was developed with nitrocellulose membrane as the solid phase support built in a 96 well porous polystyrene plate. Monoethanolamine was found to be a satisfactory and better blocking agent than skimmed milk. Up to 10(4.28) TCID50 poliovirus particles/0.1 ml of stool collected in 10% skimmed milk could be detected depending on the initial titer of the antigen specific capturing serum/IgG immobilized on nitrocellulose membrane. Percentage of skimmed milk in the transport medium, composition and pH of the dilution buffer and chloroform treatment of the stool specimens before the test were important determinants of the specificity of the test. Polyvinyl affinity membrane did not appear to be superior to nitrocellulose membrane as a solid phase support.

An unusual Neisseria isolated from conjunctival cultures in rural Egypt.

Seven isolates of an unusual Neisseria sp. were obtained from eye cultures of children in two rural Egyptian villages. These Neisseria utilized only glucose, they exhibited a positive reaction when tested with antisera to crude antigen from Neisseria meningitidis and N. gonorrhoeae, and they did not react with the fluorescent antibody tests for N. gonorrhoeae or with the monoclonal antibodies used to serotype gonococci. The Egyptian isolates had colony morphology more typical of meningococci than gonococci and showed opaque and transparent colony variants. On SDS-PAGE, the major outer-membrane proteins had different patterns than those noted for comparable proteins of meningococci and gonococci; heat-modifiable outer-membrane proteins were present. Four of the six isolates examined had cryptic plasmids of 2.8 megadaltons, which were slightly larger than the cryptic plasmid of N. gonorrhoeae. These plasmids were homologous to the gonococcal cryptic plasmid, but had different restriction enzyme fragment patterns. The DNA from the Egyptian isolates, like DNA from N. meningitidis but unlike DNA from N. gonorrhoeae, could be cut with the restriction enzyme HaeIII. The frequency of transformation into a temperature-sensitive mutant of N. gonorrhoeae was 0.2 for the Egyptian isolates and 0.1 for N. meningitidis, a frequency that was 5-10-fold lower than that for the N. gonorrhoeae control isolates. Whole-cell DNA from the Egyptian isolates showed 68%-73% homology with N. gonorrhoeae and 57%-63% with N. meningitidis. On the basis of our observations, the Egyptian isolates are distinct from N. meningitidis and may represent a variant of N. gonorrhoeae. We suggest that the isolates be called Neisseria gonorrhoeae ssp. kochii.

Gonococcal attachment to eukaryotic cells.

The attachment of Neisseria gonorrhoeae to eukaryotic cells grown in tissue culture was analyzed by use of light and electron microscopy and by labeling of the bacteria with [3H]- and [14C]adenine. Isogenic piliated and nonpiliated N. gonorrhoeae from opaque and transparent colonies were studied. The results of light microscopy studies showed that the gonococci attached to cells of human origin, including Flow 2000, HeLa 229, and HEp 2. Studies using radiolabeled gonococci gave comparable results. Piliated N. gonorrhoeae usually attached in larger numbers than nonpiliated organisms, and those from opaque colonies attached more often than isogenic variants from transparent colonies. Day-to-day variation in rate of attachment was observed. Scanning electron microscopy studies showed the gonococcal attachment to be specific for microvilli of the host cells. It is concluded that more N. gonorrhoeae from opaque colonies, as compared with isogenic variants from transparent colonies, attach to eukaryotic cells grown in tissue culture.

Relation of protein I and colony opacity to serum killing of Neisseria gonorrhoeae.

Serum bactericidal tests were done for isogenic Neisseria gonorrhoeae that formed transparent or opaque colonies. Analysis of the data from individual strains showed that the molecular weight of protein I was a highly significant, but not universal, determinant of serum sensitivity or resistance. N. gonorrhoeae organisms with high-molecular-weight protein I were more serum-sensitive. Multivariate analysis of the data from 43 strains indicated that N. gonorrhoeae organisms from transparent colonies were more serum-resistant than isogenic organisms from opaque colonies (P = 0.01). Survivors of bactericidal reactions in which the initial inoculum was from opaque colonies tended to form transparent colonies. Bactericidal action by sera from men was highly associated (P less than 0.02) with the molecular weight of protein I and with the presence of protein II bands on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, whereas bactericidal action by sera from women was associated only with the molecular weight of protein I.