A collagen-binding protein involved in the differentiation of myoblasts recognizes the Arg-Gly-Asp sequence

We had earlier demonstrated that a 46-kDa glycoprotein is involved in the differentiation of rat skeletal myoblasts. We now show that the binding of this glycoprotein to collagen and gelatin is disrupted by Arg-Gly-Asp (RGD) containing peptide but not by Arg-Gly-Glu (RGE). The former peptide also selectively elutes the 46-kDa glycoprotein bound to gelatin-Sepharose. Since all other proteins which bind RGD sequences have been found at the cell surface, we attempted to localize the 46-kDa glycoprotein by means of immuno fluorescent staining and radioiodine labeling. Surprisingly, the majority of the protein was found to be localized in the endoplasmic reticulum. Protease treatment of a microsomal fraction revealed that the protein is in the interior of the reticulum. Immunoprecipitation experiments, using a polyclonal antibody against the 46-kDa protein, demonstrated that no closely related proteins exist in myoblasts and also confirmed that the protein was not a fragment of a cell-surface localized protein. These findings suggest that the RGD sequence is also used in protein recognition within the cell.     

SOME PROPERTIES OF THE YEAST YELLOW PROTEIN

The yeast yellow protein contains two prosthetic groups, one of which is undoubtedly a flavin. The nature of the other is unknown, though some of its properties are described. No catalytic function for this protein has as yet been found.     

A Comparative Analysis of Gene Expression Patterns and Cell Phenotypes between Cervical and Peripheral Blood Mononuclear Cells

Studies of the immunological environment in the female genital tract (FGT) are critical for the development of vaccines or microbicides to halt the spread of sexually transmitted infections. Challenges arise due to the difficulties of sampling from this site, and the majority of studies have been conducted utilising peripheral blood mononuclear cells. Identifying functional differences between immune cells of the FGT and peripheral blood would aid in our understanding of mucosal immunology. We compared the gene expression profile of mononuclear cells at these two sites. Messenger RNA expression analysis was performed using gene expression arrays on matched cervical mononuclear cells and peripheral blood mononuclear cells. Further cellular phenotyping was done by 10 colour flow cytometry. Of the 22,185 genes expressed by these samples, 5345 genes were significantly differentially expressed between the cell populations. Most differences can be explained by significantly lower levels of T and B cells and higher levels of macrophages and dendritic cells in the FGT compared with peripheral blood. Several immunologically relevant pathways such as apoptosis and innate immune signalling, and a variety of cytokines and cytokine receptors were differentially expressed. This study highlights the importance of the unique immunological environment of the FGT and identifies important differences between systemic and mucosal immune compartments.     

Promoting Physical Activity and Reducing Sedentary Behavior in Disadvantaged Neighborhoods: A Qualitative Study of What Women Want

Since women living in socioeconomically disadvantaged neighborhoods are more likely to be physically inactive and engage in higher levels of sedentary behavior than women living in more advantaged neighborhoods, it is important to develop and test the feasibility of strategies aimed to promote physical activity and reduce sedentary behavior amongst this high-risk target group. Thirty-seven women (aged 19–85) living in a disadvantaged neighborhood, and five key stakeholders, received a suite of potential intervention materials and completed a qualitative questionnaire assessing the perceived feasibility of strategies aimed to increase physical activity and reduce sedentary behavior. Thematic analyses were performed. Women perceived the use of a locally-relevant information booklet as a feasible strategy to increase physical activity and reduce sedentary behavior. Including weight-loss information was suggested to motivate women to be active. Half the women felt the best delivery method was mailed leaflets. Other suggestions included reference books and websites. Many women mentioned that an online activity calendar was motivational but too time-consuming to commit to. Most women preferred the information booklet as a strategy to increase physical activity/reduce sedentary behavior, yet several suggested that using the booklet together with the online calendar may be more effective. These findings make an important contribution to research informing the development of intervention strategies to increase physical activity and reduce sedentary behavior amongst women living in disadvantaged neighborhoods.     

Effects of adrenaline on the turnover of lipoprotein lipase in rat adipose tissue

The mechanisms by which adrenaline brings about a reduction in the lipoprotein lipase activity of adipose tissue in vitro were investigated. The incorporation of [3H]leucine into lipoprotein lipase was measured during 1-h pulse incubations of rat epididymal fat bodies that had been preincubated for 4 h in the presence of glucose, insulin and dexamethasone. When adrenaline was added to the incubation medium at the start of the pulse, the incorporation of [3H]leucine was markedly reduced, suggesting that the rate of the enzyme's synthesis had decreased. On the other hand, the degradation of lipoprotein lipase, as measured by the loss of 3H-labelled enzyme protein during pulse-chase incubations of the epididymal fat bodies, was found to be significantly increased by the addition of adrenaline to the incubation medium at the start of the chase period. It is concluded that adrenaline is able both to inhibit the synthesis of lipoprotein lipase and to stimulate its degradation.     

A simpler method of preprocessing MALDI-TOF MS data for differential biomarker analysis: stem cell and melanoma cancer studies

Introduction  

Raw spectral data from matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) with MS profiling techniques usually contains complex information not readily providing biological insight into disease. The association of identified features within raw data to a known peptide is extremely difficult. Data preprocessing to remove uncertainty characteristics in the data is normally required before performing any further analysis. This study proposes an alternative yet simple solution to preprocess raw MALDI-TOF-MS data for identification of candidate marker ions. Two in-house MALDI-TOF-MS data sets from two different sample sources (melanoma serum and cord blood plasma) are used in our study.     

Case studies in antelope aggression control using a GnRH agonist

Maintaining surplus captive male antelope in bachelor groups can result in aggression in some species, leading to injury or death. Suppressing endogenous testosterone using gonadotropin‐releasing hormone (GnRH) analogs has been used in primates to control aggressive behavior, but little information is available on the use of GnRH analogs in nondomestic ruminant species. The aim of this study was to investigate the effect of a slow‐release GnRH agonist (deslorelin) on circulating hormone concentrations, semen and sperm characteristics and behavior in male gerenuk, dorcas gazelle, and scimitar horned oryx. Body weight, testicular volume, circulating hormone concentrations, ejaculate traits, and behavior were recorded before and during deslorelin treatment. A GnRH challenge (with serial blood sampling) was administered to gerenuk and dorcas gazelles before and during GnRH analog treatment. Quantitative behavioral data were collected for gerenuk and dorcas gazelles for 30 min three times a week, starting 1 month before deslorelin treatment, and the mean incidence of combined aggressive behaviors (supplanting, foreleg kicking, sparring, marking, and mounting) was compared before and during deslorelin treatment. No statistical difference (P>0.05) in body weight, semen volume, sperm concentration, percent sperm motility, percent sperm plasma membrane integrity, or percent normal sperm morphology was found before or during deslorelin treatment. The characteristic rise in luteinizing hormone (LH), occurring ～10 min following administration of a GnRH challenge in untreated males, was not evident during deslorelin treatment, although tonic LH concentrations were maintained. No differences (P>0.05) in the mean incidence of any aggressive behavioral traits in gerenuk or dorcas gazelle were detected before and during deslorelin. The absence of a GnRH‐induced increase in serum LH in treated males indicated that deslorelin suppressed pituitary responsiveness to endogenous GnRH, but that the continued tonic production of LH was sufficient to maintain testosterone production, aggressive behavior, and subsequent semen production. Zoo Biol 21:435–448, 2002. © 2002 Wiley‐Liss, Inc.     

Identifying the Energy Gap: Magnitude and Determinants of 5‐Year Weight Gain in Midage Women

Objective: The aims of this study were to estimate average yearly weight gain in midage women and to identify the determinants of weight gain and gaining weight at double the average rate. Research Methods and Procedures: The study sample comprised 8071 participants (45 to 55 years old) in the Australian Longitudinal Study on Women's Health who completed mailed surveys in 1996, 1998, and 2001. Results: On average, the women gained almost 0.5 kg per year [average 2.42 kg (95% confidence interval, 2.29 to 2.54) over 5 years]. In multivariate analyses, variables associated with energy balance (physical activity, sitting time, and energy intake), as well as quitting smoking, menopause/hysterectomy, and baseline BMI category were significantly associated with weight gain, but other behavioral and demographic characteristics were not. After adjustment for all of the other biological and behavioral variables, the odds of gaining weight at about twice the average rate (>5 kg over 5 years) were highest for women who quit smoking (odds ratio = 2.94; 95% confidence interval, 2.17, 3.96). There were also independent relationships between the odds of gaining >5 kg and lower levels of habitual physical activity, more time spent sitting, energy intake (but only in women with BMI > 25 at baseline), menopause transition, and hysterectomy. Discussion: The average weight gain equates with an energy imbalance of only about 10 kcal or 40 kJ per day, which suggests that small sustained changes in the modifiable behavioral variables could prevent further weight gain.