The gene for human chromogranin A (CgA) is located on chromosome 14

Chromogranin A (CgA) is a protein that is present in most neuroendocrine tissues and is co-secreted with their resident hormones. We have assigned the CgA gene to human chromosome 14 by hybridization of a CgA cDNA probe cloned from a cDNA library of human medullary thyroid carcinoma cells to spots of individual human chromosomes flow-sorted onto nitrocellulose filters. Southern analysis of human genomic DNA with the same probe revealed only 1-3 restriction bands. These studies indicate that the CgA gene is probably single copy and not a member of a dispersed, multigene family. The CgA gene is not co-localized with the genes of any of the CgA-associated hormones.     

The Ubp15 deubiquitinase promotes timely entry into S phase in Saccharomyces cerevisiae

The anaphase-promoting complex in partnership with its activator, Cdh1, is an E3 ubiquitin ligase responsible for targeting cell cycle proteins during G1 phase. In the budding yeast Saccharomyces cerevisiae, Cdh1 associates with the deubiquitinating enzyme Ubp15, but the significance of this interaction is unclear. To better understand the physiological role(s) of Ubp15, we examined cell cycle phenotypes of cells lacking Ubp15. We found that ubp15∆ cells exhibited delayed progression from G1 into S phase and increased sensitivity to the DNA synthesis inhibitor hydroxyurea. Both phenotypes of ubp15∆ cells were rescued by additional copies of the S-phase cyclin gene CLB5. Clb5 is an unstable protein targeted for proteasome-mediated degradation by several pathways. We found that during G1 phase, the APC^Cdh1-mediated degradation of Clb5 was accelerated in ubp15∆ cells. Ubp15 interacted with Clb5 independent of Cdh1 and deubiquitinated Clb5 in a reconstituted system. Thus deubiquitination by Ubp15 counteracts APC activity toward cyclin Clb5 to allow Clb5 accumulation and a timely entry into S phase.     

Natural transformation of Streptococcus crista

Abstract Most brewing strains of Saccharomyces cerevisiae flocculate following growth in beer wort. However, many do not flocculate in laboratory culture media, because their initial pH and buffering capacity do not correspond to the pH range within which these yeasts flocculate. Many, though not all, NewFlo phenotype brewing yeasts flocculate within a narrow pH range only; this is indicative of the existence of more than one NewFlo flocculation phenotype. Such strains may be flocculated by small alterations of pH to within the flocculation range. Induction of flocculation by pH change may be used to separate cells from media at any stage during fermentation.     

The protein content of extracellular fluids and its relevance to the study of ionic regulation: net charge and colloid osmotic pressure

1. Protein net charge in blood plasma and haemolymph is relevant to overall anion-cation balance, Donnan equilibria, colloid osmotic pressures (COPs), buffering and liquid junction potentials, but its definition and measurement are not always straightforward. 2. Normal values of protein net charge in man and other animals are discussed, as is their dependence on pH. 3. Although it is clear that charge on a protein augments COP, the theory of COP is still incomplete. 4. The dependence of COP on protein and salt concentrations and on pH are therefore considered empirically. 5. Normal values for COP in various animals are given and the regulation of COP is discussed.     

Design of a New Type of Compact Chemical Heater for Isothermal Nucleic Acid Amplification

Previous chemical heater designs for isothermal nucleic acid amplification have been based on solid-liquid phase transition, but using this approach, developers have identified design challenges en route to developing a low-cost, disposable device. Here, we demonstrate the feasibility of a new heater configuration suitable for isothermal amplification in which one reactant of an exothermic reaction is a liquid-gas phase-change material, thereby eliminating the need for a separate phase-change compartment. This design offers potentially enhanced performance and energy density compared to other chemical and electric heaters.     

Regional mapping of the creatine kinase b (CKBB) gene in rabbit (Oryctolagus cuniculus) and man using a rat cDNA probe

Using a rat creatine kinase (brain form) cDNA clone for in situ hybridization, we have localized the gene in both the human and the rabbit complement. An analysis of the data shows that the locus in the human is at 14q32, confirming previous assignments based on somatic hybridization studies and Southern blot analysis. In the rabbit, significant accumulation on 20q13----qter with the predominant labeling at the end of the chromosome provides evidence for the localization of the gene at this site. The heterologous hybridizations of a rat probe to both human and rabbit metaphases underscore the highly conserved nature of the sequences for this enzyme.     

Influence of the Vaginal Microbiota on Toxic Shock Syndrome Toxin 1 Production by Staphylococcus aureus

Menstrual toxic shock syndrome (TSS) is a serious illness that afflicts women of premenopausal age worldwide and arises from vaginal infection by Staphylococcus aureus and concurrent production of toxic shock syndrome toxin-1 (TSST-1). Studies have illustrated the capacity of lactobacilli to reduce S. aureus virulence, including the capacity to suppress TSST-1. We hypothesized that an aberrant microbiota characteristic of pathogenic bacteria would induce the increased production of TSST-1 and that this might represent a risk factor for the development of TSS. A S. aureus TSST-1 reporter strain was grown in the presence of vaginal swab contents collected from women with a clinically healthy vaginal status, women with an intermediate status, and those diagnosed with bacterial vaginosis (BV). Bacterial supernatant challenge assays were also performed to test the effects of aerobic vaginitis (AV)-associated pathogens toward TSST-1 production. While clinical samples from healthy and BV women suppressed toxin production, in vitro studies demonstrated that Streptococcus agalactiae and Enterococcus spp. significantly induced TSST-1 production, while some Lactobacillus spp. suppressed it. The findings suggest that women colonized by S. aureus and with AV, but not BV, may be more susceptible to menstrual TSS and would most benefit from prophylactic treatment.     

Long-term light adaptation in photoreceptors of the housefly, Musca domestica

The photoreceptors of many animals adapt, when illuminated, by reducing their sensitivities to light and improving their response speeds. Light adaptation is usually considered to be rapid and complete within minutes. However, under bright light conditions, I show that functionally significant improvements in impulse response amplitude and speed continue over the course of an hour in photoreceptors of the fly, Musca domestica. After sustained illumination, the average information rate, a measure of signalling performance, improved by 28% in a sample of sixteen photoreceptors. This long-term light adaptation is a robust phenomenon across animals and is repeatable within the same cell when light-adapting sessions are separated by a period of darkness. White-noise analysis of voltage responses to light and current stimuli indicate that much of the long-term changes observed are attributable to an improvement in the reliability with which photoreceptors register the timing of photon absorptions. It is also found that the impedance amplitude of the photoreceptor increases during long-term adaptation, suggesting that the area of the photoreceptor's membrane is reduced.