Peptidoglycan and teichoic acid from Staphylococcus epidermidis stimulate human monocytes to release tumour necrosis factor-α, interleukin-1β and interleukin-6

Abstract Cytokines play a major role in the pathophysiology of septic shock. In this study, human periferal blood monocytes were stimulated with peptidoglycan and teichoic acid, purified from a strain of Staphylococcus epidermidis . Polymyxin B (PM-B) was added to avoid the effects of possible contamination with endotoxin. Tumour necrosis factor-α (TNF), interleukin-1β (IL-1), and interleukin-6 (IL-6) in the supernates were measured by enzyme-linked immunosorbent assays. Peptidoglycan and teichoic acid induced TNF, IL-1, and IL-6 in a concentration-dependent manner. Teichoic acid was a weaker inducer than peptidoglycan, especially for IL-1. Lipopolysaccharide from an E. coli strain was used as a control, being 100–1000 times more potent than peptidoglycan and teichoic acid.     

Discovery of novel small molecule activators of β-catenin signaling

Wnt/β-catenin signaling plays a major role in embryonic development and adult stem cell maintenance. Reduced activation of the Wnt/β-catenin pathway underlies neurodegenerative disorders and aberrations in bone formation. Screening of a small molecule compound library with a β-galactosidase fragment complementation assay measuring β-catenin nuclear entry revealed bona fide activators of β-catenin signaling. The compounds stabilized cytoplasmic β-catenin and activated β-catenin-dependent reporter gene activity. Although the mechanism through which the compounds activate β-catenin signaling has yet to be determined, several key regulators of Wnt/β-catenin signaling, including glycogen synthase kinase 3 and Frizzled receptors, were excluded as the molecular target. The compounds displayed remarkable selectivity, as they only induced β-catenin signaling in a human osteosarcoma U2OS cell line and not in a variety of other cell lines examined. Our data indicate that differences in cellular Wnt/β-catenin signaling machinery can be exploited to identify cell type-specific activators of Wnt/β-catenin signaling.     

Rectal Swabs for Analysis of the Intestinal Microbiota

The composition of the gut microbiota is associated with various disease states, most notably inflammatory bowel disease, obesity and malnutrition. This underlines that analysis of intestinal microbiota is potentially an interesting target for clinical diagnostics. Currently, the most commonly used sample types are feces and mucosal biopsy specimens. Because sampling method, storage and processing of samples impact microbiota analysis, each sample type has its own limitations. An ideal sample type for use in routine diagnostics should be easy to obtain in a standardized fashion without perturbation of the microbiota. Rectal swabs may satisfy these criteria, but little is known about microbiota analysis on these sample types. In this study we investigated the characteristics and applicability of rectal swabs for gut microbiota profiling in a clinical routine setting in patients presenting with various gastro-intestinal disorders. We found that rectal swabs appeared to be a convenient means of sampling the human gut microbiota. Swabs can be performed on demand, whenever a patient presents; swab-derived microbiota profiles are reproducible, whether they are gathered at home by patients or by medical professionals in an outpatient setting and may be ideally suited for clinical diagnostics and large-scale studies.     

Application of light-emitting diodes in bioreactors: flashing light effects and energy economy in algal culture (Chlorella pyrenoidosa)

Light-emitting diodes (LEDs) were used as the sole light source in continuous culture of the green alga Chlorella pyrenoidosa. The LEDs applied show a peak emission at 659 nm with a half-power bandwidth of 30 nm. Selection of this wavelength range, which is optimal for excitation of chlorophylls a and b in their "red" absorption bands makes all photons emitted potentially suitable for photosynthesis. No need for additional supply of blue light was found. A standardized panel with 2 LEDs cm(-2) fully covered one side of the culture vessel. At standard voltage in continuous operation the light output of the diode panel appeared more than sufficient to reach maximal growth. Flash operation (5-mus pulse duration) enables potential use of higher operating voltages which may render up to three times more light output. Flat airlift fermentor-type continuous culture devices were used to estimate steady state growth rates of Chlorella pyrenoidosa as a function of the light flux (micromol photons x m(-2) x s(-1)) and the flashing frequency of the light-emitting diodes (which determines the duration of the dark "off" time between the 5-micros "on" pulses). At the fixed voltage and turbidostat setting applied a 20-kHz frequency, which equals dark periods of 45 mus, still permitted the maximum growth rate to become nearly reached. Lower frequencies fell short of sustaining the maximal growth rate. However, the light flux decrease resulting from lowering of the flash frequency appeared to reduce the observed growth rates less than in the case of a similar flux decrease with light originating from LEDs in continuous operation. Flash application also showed reduction of the quantum requirement for oxygen evolution at defined frequencies. The frequency domain of interest was between 2 and 14 kHz. LEDs may open interesting new perspectives for studies on optimization of mixing in mass algal culture via the possibility of separation of interests in the role of modulation on light energy conversion and saturation of nutrient supply. Use of flashing LEDs in indoor algal culture yielded a major gain in energy economy in comparison to luminescent light sources. (c) 1996 John Wiley & Sons, Inc.     

Oviductal epithelium of the baboon: hormonal control and the immuno-gold localization of oviduct-specific glycoproteins

Oviducts were obtained from a series of cycling and ovariectomized steroid-treated baboons. The lining epithelium of the ampulla and isthmus was analyzed by light and electron microscopy. Both morphological and cytomorphometric analyses revealed that the morphological and functional state of the oviductal epithelium in the baboon is controlled by the ovarian steroids. Additionally, a clear cephalocaudal steroid-responsive gradient was observed when the data from the ampulla and isthmus of the same animal were compared. Within the ampulla, estradiol induced hypertrophy, hyperplasia, ciliogenesis, and secretory activity, whereas adding progesterone to the treatment regimen (+/- estradiol) resulted in atrophy, deciliation, apoptosis, and loss of the secretory activity. These cyclic processes were less evident in the isthmus. We also used an indirect electron microscopic immunogold technique and a previously characterized polyclonal antibody to determine the localization of oviduct-specific glycoproteins. These glycoproteins were present in every secretory granule observed, regardless of oviduct region, electron density, or size of the secretory granule. In summary, our data show that 1) estradiol induces and maintains the mature epithelium of the baboon oviduct, 2) steroid withdrawal or the administration of progesterone causes regression of the epithelium, and 3) the previously identified estradiol-dependent oviduct-specific glycoproteins are synthesized within and released from the secretory epithelial cells.     

Immunocytochemical localization and messenger ribonucleic acid levels of a progesterone-dependent endometrial secretory protein (cathepsin L) in the pregnant cat uterus.

The purpose of this study was to localize immunocytochemically a progesterone-dependent protein (PDP) and to determine PDP mRNA levels during the initial stage of the implantation period. Uterine tissue was collected from Day 0-18 postcoital animals. The tissue was processed for immunocytochemical localization of PDP, and the endometrial RNA was isolated and analyzed for PDP gene expression by slot-blot hybridization. PDP was detected immunocytochemically as early as Day 5 postcoitus in the epithelial cells of the deep uterine glands, and the intensity of immunostaining appeared to peak by Day 12 postcoitus. PDP was absent in the endometrium obtained from implantation sites after Day 16 postcoitus, but the synthesis of PDP was maintained in the endometrium obtained from nonimplantation sites. Immunogold electron microscopy demonstrated that PDP was present in electron-dense granules of the glandular epithelial cells. PDP mRNA was detectable in the endometrium at Day 5 postcoitus and peaked around Day 10 postcoitus. PDP mRNA was absent in the endometrium from implantation sites after Day 16 postcoitus, but was maintained in the endometrium from nonimplantation sites. In summary, the results of this study illustrate that PDP is synthesized within the epithelial cells of the deep uterine glands, packaged within membrane-bound secretory granules, and released into the uterine lumen. Also, the process of implantation alters the gene expression in a very localized way since PDP mRNA and PDP-positive granules were absent in the endometrial glands obtained from the implantation site within 1-2 days of the onset of implantation, whereas both PDP mRNA and PDP-positive granules were maintained in the endometrial glands from nonimplantation-site regions.(ABSTRACT TRUNCATED AT 250 WORDS)