Is fecundability associated with month of birth? An analysis of 19th and early 20th century family reconstitution data from The Netherlands

The relationship between fecundability and month of birth was investigated in a cohort of 1526 women who married between 1802 and 1929, using only women whose first marriage occurred before the age of 35 years. On the basis of their time to pregnancy (TTP, calculated as time between wedding and first birth minus gestational length), women were categorized into two groups: fecunds (TTP up to 12 months or prenuptial conceptions, n = 1348) and subfecunds (TTP >18 months, n = 118). By use of logistic regression, cosinor functions with a period of 1 year or 6 months and variable shift and amplitude were fitted through the monthly odds of subfecunds versus fecunds. The best fitting curve was unimodal, with a zenith in September (P = 0.13 for H0: no differences). Exclusion of childless women (n = 36, minimum follow-up 5 years) from the subfecunds led to a similar curve (P < 0.01), while childless women, as compared with fecunds, showed a birth distribution that was best represented with a bimodal curve with zeniths in January and July (P = 0.06). This study provides evidence for the existence of differences in fecundability by month of birth. The cause of this relationship is unclear, but may lie in a melatonin-dependent circannual variability of the quality of the oocyte.      

Immunohistochemical characteristics of diffuse sclerosing variant of papillary carcinoma: comparison with conventional papillary carcinoma

Koo JS, Shin E, Hong SW. Immunohistochemical characteristics of diffuse sclerosing variant of papillary carcinoma: comparison with conventional papillary carcinoma. APMIS 2010; 118: 744–52. Diffuse sclerosing variant of papillary carcinoma (DSVPC) is a rare variant of papillary thyroid carcinoma (PTC). It shows different clinicopathologic features to the conventional PTC, but the immunohistochemical characteristics of DSVPC are yet to be more clearly defined. The purpose of this study was to investigate the immunohistochemical features of DSVPC, which are different from those of PTC. Tissue microarray was constructed from the paraffin‐embedded tissue of 49 DSVPC and 50 conventional PTC samples. Immunohistochemical stains for p63, p53, galectin‐3, cytokeratin 19, β‐catenin, Bcl‐2, EMA, E‐cadherin, CD15, and CD56 were performed on each tissue microarray. Immunohistochemical stain for p63 was negative in all conventional PTCs, but 14 (28.6%) cases of DSVPC showed p63 expression (p = 0.000). p53 was expressed in 38 (76.0%) cases of conventional PTC and 21 (42.9%) cases of DSVPC (p = 0.001). Galectin‐3 was expressed in all 50 cases of conventional PTC, but eight (16.3%) cases of DSVPC did not express galectin‐3 (p = 0.003). EMA was expressed more in DSVPC (40.8%) than in conventional PTC (20.0%, p = 0.024). In univariate analyses, Bcl‐2 positivity (p = 0.016) and EMA negativity (p = 0.036) in DSVPC were associated with shorter time interval to tumor recurrence, but there was no significance for the two in multivariate analyses. DSVPC, a rare variant of PTC, has different immunohistochemical features from the conventional PTC, showing higher expression rate of p63 and lower expression rate of p53. It also shows galectin‐3 negativity and EMA positivity.     

Whole body immersion and hydromineral homeostasis: effect of water temperature

This experiment was designed to assess the effects of prolonged whole body immersion (WBI) in thermoneutral and cold conditions on plasma volume and hydromineral homeostasis.10 navy “combat swimmers” performed three static 6-h immersions at 34°C (T34), 18°C (T18) and 10°C (T10). Rectal temperature, plasma volume (PV) changes, plasma proteins, plasma and urine ions, plasma osmolality, renin, aldosterone and antidiuretic hormone (ADH) were measured. Results show that compared to pre-immersion levels, PV decreased throughout WBI sessions, the changes being markedly accentuated in cold conditions. At the end of WBI, maximal PV variations were ?6.9% at T34, ?14.3% at T18, and ?16.3% at T10. Plasma osmolality did not change during and after T34 immersion, while hyperosmolality was present at the end of T18 immersion and began after only 1 h of T10 immersion. In the three temperature conditions, significant losses of water (1.6–1.7 l) and salt (6–8 g) occurred and were associated with similar increases in osmolar and free water clearances. Furthermore, T18 and T10 immersions increased the glomerular filtration rate. There was little or no change in plasma renin and ADH, while the plasma level of aldosterone decreased equally in the three temperature conditions. In conclusion, our data indicate that cold water hastened PV changes induced by immersion, and increased the glomerular filtration rate, causing larger accumulated water losses. The iso-osmotic hypovolemia may impede the resumption of baseline fluid balance. Results are very similar to those repeatedly described by various authors during head-out water immersion.     

Behavioural Effects of the Methanolic Root Bark Extract of Securinega Virosa in Rodents

Securinega virosa is used traditionally as sedative in children and in mental illnesses. In this study, the behavioral effects of methanolic root bark extract of S. virosa were investigated in mice. The results revealed that the extract significantly (P<0.05) and dose-dependently reduced the onset and prolonged the duration of sleep. The extract significantly (P<0.05) decreased exploratory activity and reduced the rate of apomorphine-induced stereotyped climbing at the doses tested (6.25–25mg/kg). It also produced a significant and dose-dependent motor coordination deficit in mice at the doses tested (P<0.01). The intraperitoneal median lethal dose in mice was 774.6mg/kg while the preliminary phytochemical screening revealed the presence of alkaloids, tannins, saponins and flavonoids. These results suggest that methanolic root bark extract of S. virosa contains biologically active principles that are sedative in nature and lend pharmacological credence to the ethnomedical use of the plant.     

Streptococcus pneumoniae Capsular Serotype 19F Is More Resistant to C3 Deposition and Less Sensitive to Opsonophagocytosis than Serotype 6B

The polysaccharide capsule is a major virulence mechanism of Streptococcus pneumoniae, shielding the bacterium from phagocytes. Capsule types may differ in their abilities to resist immune defense. Antibody-mediated complement activation and opsonophagocytosis are crucial in protection against pneumococcus. Conjugate vaccine trials suggest imperfect protection against 19F. We have previously shown that significantly more anti-19F than anti-6B antibody is needed for killing in the opsonophagocytic assay (OPA). In this study, we explored whether the amount of C3 deposited on serotype 6B and 19F pneumococcal strains reflects their sensitivity to opsonophagocytosis. We compared clinical 6B and 19F nasopharyngeal, middle ear, and blood isolates as well as reference OPA strains (n = 16) for their sensitivity to opsonophagocytosis and C3 deposition. Sixfold anticapsular antibody concentrations were required for 50% opsonophagocytic killing of 19F compared to that of 6B strains. Serotype 19F was more resistant to C3 deposition than 6B. Complement deposition and opsonophagocytosis were dependent on the concentration of anticapsular antibodies. Differences between pneumococcal serotypes in antibody-mediated protection may partly be explained by the abilities of the capsules to resist complement deposition. These findings support previous studies suggesting that higher antibody concentrations to the capsular polysaccharide are needed for protection against disease caused by serotype 19F than that caused by 6B.     

Role of Pht Proteins in Attachment of Streptococcus pneumoniae to Respiratory Epithelial Cells

Pneumococcal adherence to mucosal surfaces is a critical step in nasopharyngeal colonization, but so far few pneumococcal adhesins involved in the interaction with host cells have been identified. PhtA, PhtB, PhtD, and PhtE are conserved pneumococcal surface proteins that have proven promising as vaccine candidates. One suggested virulence function of Pht proteins is to mediate adherence at the respiratory mucosa. In this study, we assessed the role of Pht proteins in pneumococcal binding to respiratory epithelial cells. Pneumococci were incubated with human nasopharyngeal epithelial cells (Detroit-562) and lung epithelial cells (A549 and NCI-H292), and the proportion of bound bacteria was measured by plating viable counts. Strains R36A (unencapsulated), D39 (serotype 2), 43 (serotype 3), 4-CDC (serotype 4), and 2737 (serotype 19F) with one or more of the four homologous Pht proteins deleted were compared with their wild-type counterparts. Also, the effect of anti-PhtD antibodies on the adherence of strain 2737 to the respiratory epithelial cells was studied. Our results suggest that Pht proteins play a role in pneumococcal adhesion to the respiratory epithelium. We also found that antibody to PhtD is able to inhibit bacterial attachment to the cells, suggesting that antibodies against PhtD present at mucosal surfaces might protect from pneumococcal attachment and subsequent colonization. However, the relative significance of Pht proteins to the ability of pneumococci to bind in vitro to epithelial cells depends on the genetic background and the capsular serotype of the strain.     

Effects of various beverages on the hormones involved in energy metabolism during exercise in the heat in previously dehydrated subjects

The objective of our study was to examine the effects of beverage content on hormone responses involved in fuel substrate metabolism (catecholamines, insulin and glucagon) in previously dehydrated subjects exercising at a moderate intensity in the heat. Six healthy men walked for 60-min on five occasions at 50% maximal oxygen uptake in a warm environment (dry bulb temperature 35?±?0.2°C, relative humidity 20%). On each occasion, the subjects were dehydrated before exercise (loss of 2% body mass) by passive controlled hyperthermia, which led to a reduction in plasma volume (PV) of about ?5% to ?9%. In one session, the subjects exercised without rehydration (Dh). In the other sessions, four beverages (650?ml) were given just before the exercise: mineral water (W), a 60?g?·?l^?1 glucose and 1.2?g?·?l^?1 NaCl solution (GS), a 60?g?·?l^?1 maltodextrin solution, and a 60?g?·?l^?1 maltodextrin and 1.2?g?·?l^?1 NaCl solution. Compared to Dh and W, carbohydrate supply with or without NaCl induced a higher glycaemia (P?P?P?P?P?相似文献