Specific rubella virus IgG and IgM in umbilical cord sera in Saudi Arabia.

The sensitive ELISA assay was used to measure the specific rubella virus IgG & IgM, and also the total IgM in the umbilical cord sera taken from 182 Saudi mothers during delivery in the Maternity Department at Al Ali General Hospital, Riyadh, Saudi Arabia. Nearly 84.6% (154 out of 182) Saudi women tested were found to be immune to rubella virus.     

Role of immersion refractometry for investigating laser-induced effects in cells.

The broad background of scattered light observed in spectra of cell suspensions is reduced by factors of up to 20 by immersion refractometry allowing for improved spectroscopic determination of the absorption properties of cells in the 325-820 nm range. Refractive-index matched spectra of E. coli C1a exhibit a set of resonant features near 422, 561, and 582 nm. Exposure wavelengths are chosen based on this spectrum and cell viability is investigated in E. coli suspensions exposed to 350, 400, 422, 440, and 700 nm radiation delivered in nanosecond pulses with total doses from 500 millijoules to 60 Joules. We observe a loss in cell viability for doses greater than 1 Joule at 422 nm and for all doses at other wavelengths; exposures of less than 1 Joule at 422 nm enhance growth. Excluding exposures at wavelengths within the resonant feature, longer wavelengths are less effective at reducing the viability of E. coli C1a. This indicates the occurrence of at least two absorption processes.     

Aortic responsiveness to nitric oxide is affected by seasonal variation.

Cardiac attacks and sudden cardiac deaths are more common in cold seasons. Up to now the underlying pathophysiologic mechanism of the seasonal variation in cardiovascular accidents is scarcely known. There are many physiological mechanisms which exhibit seasonal variation (e.g. blood pressure). Nitric oxide (NO) is a potent vasodilator, and impaired responsiveness to its physiological effects has been reported in many pathological situations including cardiovascular accidents. The aim of the present study was to evaluate the role of NO-dependent mechanisms on seasonal variation in aortic relaxation in vitro in rats. Male Sprague-Dawley rats grown up in different seasons in natural light/dark situation were used in the study, while the temperature and humidity were kept constant throughout the study (22+/-1 degrees C). The in vitro aortic ring responsiveness to an NO donor was studied in different seasons. Intact and denuded rings were pre-contracted with phenylephrine and vaso-relaxatory response to sodium isosorbide dinitrate (10(-8) to 10(-4)M) was recorded in vitro. The vaso-relaxatory response to isosorbide dinitrate (10(-6)M) was higher in aortic rings obtained in summer compared with those in winter and fall. There was a significant difference in EC(50) of sodium isosorbide dinitrate-induced vaso-relaxation of rings obtained from rats which were grown up in summer and winter (EC(50): 2.23+/-0.069 versus 4.31+/-0.088, P<0.05). The maximum response (R(max)) to isosorbide dinitrate was, however, identical in rings obtained from these rats. In conclusion, the in vitro responsiveness of aorta to NO is affected by seasonal light/dark periods the rats are exposed. This might be one of the reasons why more sudden cardiac deaths occur also in humans during winter.     

Fetal electrocardiotocography in labor and neonatal outcome: an observational study in 1889 patients in the French center of Edouard Herriot, Lyon.

BACKGROUND: The STAN methodology has been shown to reduce both operative delivery for fetal distress and the cord artery metabolic acidosis rate. OBJECTIVE: The objective of this study was to monitor delivery modes and perinatal outcomes following the introduction of the STAN methodology and the evolution of its use at our institution. METHODS: Two periods were characterized: June 2000-June 2002 (period 1) and July 2002-April 2005 (period 2). Parity, mode of labor and delivery, ST events, and neonatal outcome (Apgar score and pH of the umbilical cord artery and vein), cases of metabolic acidosis and operative delivery for fetal distress were studied. RESULTS: One thousand eight hundred and eighty-nine women were included in the study. The rate of use of STAN increased from 13.5% to 16% over these two time periods. The rate of metabolic acidosis was low: 0.28% and 0.45%, respectively. No cases of neonatal encephalopathy or of perinatal death were diagnosed. There was a decrease in the rate of operative delivery for fetal distress (163/701 (22.9%) vs. 228/1111 (20.3%), p = 0.26). CONCLUSIONS: According to the literature, our use of the STAN appears to be very successful; the metabolic acidosis rate was 0.38% and the rate of operative delivery for fetal distress decreased. We improved the accuracy of the interpretation of the fetal heart rate.     

Non-expression of a common mutation in the 21-hydroxylase gene: implications for prenatal diagnosis and carrier testing.

Mutation analysis in the family of a child with 21-hydroxylase deficiency showed that the father and affected child were homozygous for a mutation, A/C655G, believed to activate a cryptic splice site in intron 2 of the 21-hydroxylase gene. The father, who was clinically asymptomatic, showed no biochemical evidence of disease. These results create problems for the management of future pregnancies in such families and for the interpretation of the risk associated with carrier status for this mutation.     

gp49B1 suppresses stem cell factor-induced mast cell activation-secretion and attendant inflammation in vivo

We report that gp49B1, a mast cell membrane receptor with two immunoreceptor tyrosine-based inhibitory motifs (ITIM), constitutively inhibits mast cell activation-secretion induced by stem cell factor (SCF), a tissue-derived cytokine that also regulates mast cell development. The intradermal injection of SCF into the ears of gp49B1 null (gp49B(-/-)) mice elicited approximately 4- and 2.5-fold more degranulating mast cells and tissue swelling caused by edema, respectively, than in gp49B(+/+) mice. SCF did not induce tissue swelling in mast cell-deficient mice, and the responsiveness of gp49B(-/-) mice to mast cell-associated amine and lipid mediators was unaltered. When gp49B(+/+) and gp49B(-/-) mice were pretreated with antagonists of the amines, SCF-induced tissue swelling was reduced by >90% and 60%, respectively, and it was reduced by >90% in both genotypes when a cysteinyl leukotriene receptor antagonist was also provided. Hence, the dominant contribution of secretory granule amines to SCF-induced tissue swelling is the result of gp49B1-mediated inhibition of the production of cysteinyl leukotrienes by mast cells. Our findings also provide the first example of an ITIM-bearing receptor that constitutively suppresses inflammation generated in vivo independently of the adaptive immune response by a receptor that signals through intrinsic tyrosine kinase activity rather than immunoreceptor tyrosine-based activation motifs.     

Bacterial adherence to nasal mucosal cells.

The ability of several bacterial species to adhere to human nasal mucosal cells and their distribution on nasal mucosal surfaces was studied. Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pyogenes, and Pseudomonas aeruginosa adhered to scraped nasal mucosal cells. In contrast, viridans streptococci and Klebsiella pneumoniae exhibited feeble or no adherence to nasal mucosal cells. S. aureus affinity for the nasal mucosal cells of carriers of S. aureus was greater than for those of the noncarriers (P less than 0.005). Heat treatment of S. aureus did not block, but slightly reduced, its binding to mucosal cells. The data suggest a high degree of specificity involved in the adherence of bacteria to nasal mucosal cells. The greater affinity of S. aureus for the nasal mucosal cells of carriers (than noncarriers) seems to be a property of mucosal cells rather than bacteria.     

Protection of Chicken Embryos by Viridans Streptococci Against the Lethal Effect of Staphylococcus aureus

Chicken embryos were used to investigate the mechanism by which viridans streptococci inhibit the growth of pathogenic staphylococci. Ten-day-old embryonated eggs were infected allantoically. At a concentration of 1.8 x 10(2) colony-forming units (CFU) of viridans streptococci, the percentage of fatalities was less than 10%. There was 80% fatality with 8 x 10(1) CFU of Staphylococcus aureus strain 502A and 100% when a 100-fold increase in concentration was used. An inoculum size of 10(2) to 10(3) CFU of viridans streptococci was chosen to protect the embryos against the lethal effect of strain 502A when challenged 24 h later. The survival after challenging at 4 days was 93% in protected eggs and 37% in unprotected eggs. Chicken embryos receiving heat-killed viridans and challenged with strain 502A when examined after 4 days did not demonstrate a protective effect. This protection of embryonated eggs could not be transferred by administration of sterile filtrate of allantoic fluid in which protecting strain was grown. The experimental infection of embryonated eggs has demonstrated that prior allantoic infection with viridans streptococci affords significant protection against subsequent challenge with virulent staphylococci.     

Chromosome abnormalities in benign prostatic hyperplasia

We combined conventional cytogenetic analysis and fluorescence in situ hybridization of short-term cultures of 28 samples from benign prostatic hyperplasia. Lou of the Y chromosome was the most common chromosome change, followed by trisomy 7. Trisomy 7, however, may be unrelated to the origin of benign prostate hyperplasia, in which the only and not very specific change seems to be the loss of the Y chromosome. Genes Chrom Cancer 9:227-233 (1594). © 1994 Wiley-Liss, Inc.