Identification of nuclear spliceosomal antigens targeted by NOD mouse antibodies following sodium iodide intake.

The non-obese diabetic (NOD) mouse spontaneously develops a range of autoreactive responses including an autoantibody response to nuclear antigens. As elevated dietary iodine has been shown to increase thyroid autoimmune pathology in NOD mice, the effect of sodium iodide (NaI) on the development of anti-nuclear antibodies (ANA) was assessed. Interestingly, the NaI symporter is expressed in both thyroid and salivary glands. Elevated dietary iodine was found to increase the percentage of male NOD mice developing autoantibodies. Specifically, the nuclear autoantibodies that develop in NOD mice were shown to target specific spliceosomal components. The target specificity of the autoantibodies was determined using recombinant spliceosomal proteins and shown to include U1A, U170K, U2B'', U2A', as well as the Sm proteins D1, D2, and B. The autoantibody isotypes most consistently represented were IgG2a and IgG2b.

Physical activity and osteoporosis: disparities between knowledge and practice.

Osteoporosis and osteoporosis-related conditions are national health priorities, and physical activity has been associated with a reduction of osteoporosis risk factors (i.e., increased bone mineral density and decreased falls). Our study examined the disparity between awareness of physical activity as an osteoporosis prevention strategy and the quantity and quality of physical activity performed. Results indicate that most individuals view physical activity as an important prevention strategy. However, few participants are engaged in physical activity which meets current public health recommendations despite their awareness of physical activity health benefits. Barriers to regular exercise are discussed as well as promising approaches to reducing barriers through alterations to physical and social environments.

Structure and assembly of the spliceosomal snRNPs. Novartis Medal Lecture.

The spliceosome is a macromolecular machine that carries out the excision of introns from eukaryotic pre-mRNAs and splicing together of exons. Four large RNA-protein complexes, called the U1, U2, U4/U6 and U5 small nuclear ribonucleoprotein particles (snRNPs), and some non-snRNP proteins assemble around three short conserved sequences within the intron in an ordered manner to form the active spliceosome. We aim to provide insight into the molecular details of the mechanism of pre-mRNA splicing through crystallographic studies of the snRNPs. We have solved the X-ray crystal structure of some snRNP proteins as part of either protein-protein complexes or RNA-protein complexes. These structures have provided an important insight into the overall architecture of the U1 and U2 snRNPs and the mechanisms of RNA-protein and protein-protein recognition.

Cardiovascular health interventions in women: What works?

Women's Cardiovascular Health Network members representing 10 Prevention Research Centers completed a literature review of approximately 65 population-based studies focused on improving women's cardiovascular health through behavior change for tobacco use, physical inactivity, or diet. A framework was developed for conducting the search. Databases (Medline, Psychlit, Smoking and Health, Cumulative Index to Nursing and Allied Health Literature) of studies published from 1980 to 1998 were searched. The review was presented at a meeting of experts held in Atlanta, Georgia. Output from the meeting included identification of what has worked to improve cardiovascular health in women and recommendations for future behavioral research. Additional information is available at www.hsc.wvu.edu/womens-cvh. Cardiovascular health interventions geared toward women are scant. Based on the available studies, program components that emerged as effective included personalized advice on diet and physical activity behaviors and tobacco cessation, multiple staff contacts with skill building, daily self-monitoring, and combinations of strategies. Recommendations for community-based tobacco, physical activity, and diet interventions are discussed. A few overarching recommendations were to (1) conduct qualitative research to determine the kinds of interventions women want, (2) examine relapse prevention, motivation, and maintenance of behavior change, (3) tailor programs to the stage of the life cycle, a woman's readiness to change, and subgroups, that is, minority, low socioeconomic, and obese women, and (4) evaluate policy and environmental interventions. The effects of cardiovascular interventions in women have been inappropriately understudied in women. Our review found that few studies on cardiovascular risk factor modification have actually targeted women. Hence, adoption and maintenance of behavior change in women are elusive. Intervention research to improve women's cardiovascular health is sorely needed.

Reconstitution of the spliceosomal U1 snRNP from all recombinant subunits and its characterisation by ionspray Q-tof mass-spectrometry.

The first important step in pre-mRNA splicing is the recognition of the 5' splice site by the U1 snRNP. It consists of U1 snRNA and 10 protein subunits. We have reconstituted the U1 snRNP from all its ten proteins produced in E. coli and U1 snRNA transcribed in vitro. We have used nano spray time-of-flight (TOF) mass spectrometer in order to characterise the reconstituted U1 snRNP and its sub-assemblies which lack one of more subunits. The reconstituted U1 snRNP and its variants remained intact as multiply charged ions within the mass spectrometer and their mass was determined. By increasing collision energy subparticles are also observed. This method provides information not only about the stoichiometry of subunits within the complex but also about subsets of interacting proteins.

Dietary intakes and leisure-time physical activity in West Virginians.

Poor diet and physical inactivity contribute to many chronic diseases in the United States each year. Diets low in saturated fatty acids and cholesterol and high in plant foods, i.e., fruits and vegetables, legumes and whole cereals, are protective. Physically active lifestyles are associated with lower risk of cardiovascular diseases, diabetes, obesity and some cancers. To access diet and physical activity levels in West Virginians, we conducted a study which was supported by the West Virginia Bureau for Public Health and the West Virginia University Prevention Research Center (CDC Cooperative Agreement). The purposes of this study were to estimate the proportion of the sample meeting recommendations for chronic disease prevention, and to examine if the individuals who were meeting the Surgeon General's physical activity recommendation for health are also consuming healthier diets. Our results showed that reducing saturated fatty acids and increasing consumption of folate, Vitamin E, calcium and fiber are of prime public health importance in West Virginia. Diet and activity levels were modestly related, suggesting that those who adopt a healthy diet also become more active and vice versa. Due to the cross-sectional nature of this data, it is unknown if single-strategy or dual interventions work best. Prospective studies are needed to determine optimal strategies.

Evidence for helical unwinding of an RNA substrate by the RNA enzyme RNase P: use of an interstrand disulfide crosslink in substrate.

To gain an understanding of structural changes induced in substrates by Escherichia coli ribonuclease P (RNase P), we have incorporated an interstrand disulfide crosslink proximal to the cleavage site in a model substrate. RNase P is able to process the reduced, non-crosslinked form of this substrate as well as a substrate in which the free thiol molecules have been alkylated with iodoacetamide. However, the oxidized, crosslinked form is cleaved at a significantly lower rate. Therefore, helical unwinding of the analog of the aminoacyl stem of the substrate near its site of cleavage may be necessary for efficient processing by E. coli RNase P.

Verification of phylogenetic predictions in vivo and the importance of the tetraloop motif in a catalytic RNA.

M1 RNA, the catalytic subunit of Escherichia coli RNase P, forms a secondary structure that includes five sequence variants of the tetraloop motif. Site-directed mutagenesis of the five tetraloops of M1 RNA, and subsequent steady-state kinetic analysis in vitro, with different substrates in the presence and absence of the protein cofactor, reveal that (i) certain mutants exhibit defects that vary in a substrate-dependent manner, and that (ii) the protein cofactor can correct the mutant phenotypes in vitro, a phenomenon that is also substrate dependent. Thermal denaturation curves of tetraloop mutants that exhibit kinetic defects differ from those of wild-type M1 RNA. Although the data collected in vitro underscore the importance of the tetraloop motif to M1 RNA function and structure, three of the five tetraloops we examined in vivo are essential for the function of E. coli RNase P. The kinetic data in vitro are not in total agreement with previous phylogenetic predictions but the data in vivo are, as only mutants in those tetraloops proposed to be involved in tertiary interactions fail to complement in vivo. Therefore, the tetraloop motif is critical for the stabilization of the structure of M1 RNA and essential to RNase P function in the cell.

Multiple binding modes of substrate to the catalytic RNA subunit of RNase P from Escherichia coli.

M1 RNA that contained 4'-thiouridine was photochemically cross-linked to different substrates and to a product of the reaction it governs. The locations of the cross-links in these photochemically induced complexes were identified. The cross-links indicated that different substrates share some contacts but have distinct binding modes to M1 RNA. The binding of some substrates also results in a substrate-dependent conformational change in the enzymatic RNA, as evidenced by the appearance of an M1 RNA intramolecular cross-link. The identification of the cross-links between M1 RNA and product indicate that they are shared with only one of the three cross-linked E-S complexes that were identified, an indication of noncompetitive inhibition by the product. We also examined whether the cross-linked complexes between M1 RNA and substrate(s) or product are altered in the presence of the enzyme's protein cofactor (C5 protein) and in the presence of different concentrations of divalent metal ions. C5 protein enhanced the yield of certain M1 RNA-substrate cross-linked complexes for both wild-type M1 RNA and a deletion mutant of M1 RNA (delta[273-281]), but not for the M1 RNA-product complex. High concentrations of Mg2+ increased the yield of all M1 RNA-substrate complexes but not the M1 RNA-product complex.

Hyperactivity: is candy causal?

Adverse behavioral responses to ingestion of any kind of candy have been reported repeatedly in the lay press. Parents and teachers alike attribute excessive motor activity and other disruptive behaviors to candy consumption. However, anecdotal observations of this kind need to be tested scientifically before conclusions can be drawn, and criteria for interpreting diet behavior studies must be rigorous. Ingredients in nonchocolate candy (sugar, artificial food colors), components in chocolate candy (sugar, artificial food colors in coatings, caffeine), and chocolate itself have been investigated for any adverse effects on behavior. Feingold theorized that food additives (artificial colors and flavors) and natural salicylates caused hyperactivity in children and elimination of these components would result in dramatic improvement in behavior. Numerous double-blind studies of the Feingold hypothesis have led to the rejection of the idea that this elimination diet has any benefit beyond the normal placebo effect. Although sugar is widely believed by the public to cause hyperactive behavior, this has not been scientifically substantiated. Twelve double-blind, placebo-controlled studies of sugar challenges failed to provide any evidence that sugar ingestion leads to untoward behavior in children with Attention-Deficit Hyperactivity Disorder or in normal children. Likewise, none of the studies testing candy or chocolate found any negative effect of these foods on behavior. For children with behavioral problems, diet-oriented treatment does not appear to be appropriate. Rather, clinicians treating these children recommend a multidisciplinary approach. The goal of diet treatment is to ensure a balanced diet with adequate energy and nutrients for optimal growth.

Evaluation of mucosal damage of surfactants in rat jejunum and colon.

Surfactants are one of the most frequently used adjuvants in oral pharmaceutical preparations, used primarily as solubilizers, stabilizers, emulsifiers, and wetting agents. However, surfactants can disrupt normal membrane structure. In this study, lactate dehydrogenase (LDH) and mucus were evaluated as potential markers of intestinal damage in a single-pass in situ perfusion model in the rat. The release of LDH and mucus into the intestinal lumen of the rat following perfusion of the nonionic surfactants Tween 80 and Triton X-100 was determined. The release rate of LDH increased in the order saline < Tween 80 < Triton X-100 in both jejunum and colon. LDH release rate was approximately three times lower in the colon than in the jejunum, but relative effects of nonionic surfactants were comparable between regions. In addition, the rate of LDH release in the jejunum increased with decreasing perfusion rates for both saline and Tween groups and with increasing Tween 80 concentrations. At each flow rate studied, mucus release rate was greater in the presence of Tween 80 and Triton X-100 than saline, but there was no significant difference between the effect of Tween 80 and Triton X-100 on mucus release rate. When perfusion of Triton X-100 was followed by saline, rates of both mucus and LDH release returned to baseline values, suggesting damage is reversible. Histological damage agreed with trends observed in LDH and mucus release rates. This model allows for early evaluation of intestinal damage due to both excipients and active ingredients and simultaneous measurement of drug absorption.

Patterns of chocolate consumption.

Although consumed in some form since at least 460 AD, cacao (Theobroma cacao) was not used in confectionery until the 19th century when the cocoa press was invented. Per capita consumption of chocolate confectionery in the United States is moderate (approximately 4.6-4.8 kg/y) compared with that of many northern European countries (approximately 7-10 kg/y). Eleven percent of the US population reported consuming chocolate candy on > or = 1 of the 3 d of recorded food intake in the US Department of Agriculture Nationwide Food Consumption Survey 1987-1988; < 1.0% consumed chocolate every day. The Western region of the United States contained the highest proportion of chocolate consumers. More whites than other racial groups were consumers. Chocolate was consumed by more people in the winter than in other seasons and more was consumed at snacks than at meals. The mean amount of chocolate consumed was approximately 30-90 g/d, depending on sex and age group. Chocolate candy was only a minor contributor (0.7-3.4%) to the overall dietary intake of total energy, fat, saturated fatty acids, and stearic acid.

Absorption of ACE inhibitors from small intestine and colon.

The intestinal absorption of two ACE inhibitors was studied to determine the potential for colonic delivery of small peptides. In addition, studies were also performed to assess intestinal tissue uptake and evaluate a canine intestinal-access-port model as techniques for screening absorption. To evaluate the impact of differences in the contributions of passive permeation and carrier-mediated peptide transport on in vitro uptake and in vivo absorption, an esterified prodrug, benazepril, and a free diacid non-prodrug, CGS 16617, were selected for study. Potential colonic absorption enhancement utilizing coadministration of Intralipid was also investigated. Studies in rat everted intestinal rings verified that jejunal benazepril uptake included a carrier-mediated component while that of the diacid did not. Uptake of both drugs was purely passive in colonic rings. Equilibrium uptake and uptake rate of the more lipophilic prodrug was 2-fold greater than the diacid. Benazepril and CGS 16617 jejunal uptake rate at 0.01 mM was 3.5 and 2.5 times higher, respectively, than from colonic rings. Following jejunal administration in dogs, maximum benazepril plasma levels (Cmax) and area under the plasma level versus time curve (AUC) were 5.5 and 3.0 times higher, respectively, than following colonic administration. Maximum benazepril plasma levels following colonic administration in dogs was 2-fold greater than for CGS 16617, consistent with in vitro results. Colonic coadministration of the poorly-absorbed CGS 16617 with 2 mL of Intralipid (within dietary range for fecal fat content) enhanced Cmax and AUC 2.5- and 3.5-fold, respectively, in the dog and AUC 1.5-fold in the rat.(ABSTRACT TRUNCATED AT 250 WORDS)

Prediction of plasma lipids in a cross-sectional sample of young women.

We studied 60 premenopausal women to identify the best predictors of plasma lipid levels. Eligible subjects gave one venous blood sample during menstruation, kept a 3-day food record, completed a demographic questionnaire, had their height and weight measured, and participated in a standardized physical activity interview. Dietary constituents, anthropometric measures, serum progesterone and estradiol concentrations, and leisure-time activity level were then examined for relationships to plasma lipids. Pearson correlations revealed associations among diet, adiposity, alcohol intake, and plasma lipids. Saturated fatty acid (SFA) intake was positively related to plasma total cholesterol, low-density-lipoprotein (LDL) cholesterol, and high-density-lipoprotein (HDL) cholesterol. Height and weight were significantly related to total triglycerides. Furthermore, in the multivariate analyses, dietary constituents and height or body weight explained more of the variance in plasma lipids than did physical activity level or sex hormones. The final models for each lipid are as follows: for plasma total cholesterol and LDL cholesterol, SFA intake was the only significant predictor, for HDL cholesterol, refined carbohydrate and SFA intake; and for total plasma triglycerides, body weight and crude fiber intake.