Homocysteine levels in preterm infants: is there an association with intraventricular hemorrhage? A prospective cohort study.

BACKGROUND: The purpose of this study was to characterize total homocysteine (tHcy) levels at birth in preterm and term infants and identify associations with intraventricular hemorrhage (IVH) and other neonatal outcomes such as mortality, sepsis, necrotizing enterocolitis, bronchopulmonary dysplasia, and thrombocytopenia. METHODS: 123 infants \u3c 32 weeks gestation admitted to our Level III nursery were enrolled. A group of 25 term infants were enrolled for comparison. Two blood spots collected on filter paper with admission blood drawing were analyzed by a high performance liquid chromatography (HPLC) method. Statistical analysis included ANOVA, Spearman\u27s Rank Order Correlation and Mann-Whitney U test. RESULTS: The median tHcy was 2.75 micromol/L with an interquartile range of 1.34 - 4.96 micromol/L. There was no difference between preterm and term tHcy (median 2.76, IQR 1.25 - 4.8 micromol/L vs median 2.54, IQR 1.55 - 7.85 micromol/L, p = 0.07). There was no statistically significant difference in tHcy in 31 preterm infants with IVH compared to infants without IVH (median 1.96, IQR 1.09 - 4.35 micromol/L vs median 2.96, IQR 1.51 - 4.84 micromol/L, p = 0.43). There was also no statistically significant difference in tHcy in 7 infants with periventricular leukomalacia (PVL) compared to infants without PVL (median 1.55, IQR 0.25 - 3.45 micromol/L vs median 2.85, IQR 1.34 - 4.82 micromol/L, p = 0.07). Male infants had lower tHcy compared to female; prenatal steroids were associated with a higher tHcy. CONCLUSION: In our population of preterm infants, there is no association between IVH and tHcy. Male gender, prenatal steroids and preeclampsia were associated with differences in tHcy levels

Estimating the Duration of Pertussis Immunity Using Epidemiological Signatures

Case notifications of pertussis have shown an increase in a number of countries with high rates of routine pediatric immunization. This has led to significant public health concerns over a possible pertussis re-emergence. A leading proposed explanation for the observed increase in incidence is the loss of immunity to pertussis, which is known to occur after both natural infection and vaccination. Little is known, however, about the typical duration of immunity and its epidemiological implications. Here, we analyze a simple mathematical model, exploring specifically the inter-epidemic period and fade-out frequency. These predictions are then contrasted with detailed incidence data for England and Wales. We find model output to be most sensitive to assumptions concerning naturally acquired immunity, which allows us to estimate the average duration of immunity. Our results support a period of natural immunity that is, on average, long-lasting (at least 30 years) but inherently variable

Distribution of Cardicola forsteri eggs in the gills of southern bluefin tuna (Thunnus maccoyii) (Castelnau, 1872)

The distribution of Cardicola forsteri eggs in the gills of southern bluefin tuna (Thunnus maccoyii) was analysed. Eggs were confirmed to be C. forsteri using laser-capture microdissection and quantitative polymerase chain reaction (qPCR) analyses. Prevalence of infection was significantly higher in the second gill arch (χ2 = 6.49, P < 0.05) than in the fourth gill arch, and significantly lower in the basal region of the second gill arch (χ2 = 6.29, d.f. = 2, P < 0.05). The intensity of infection was not significantly different between the gill arches (F = 0.03, d.f. = 1, P > 0.05). Similarly, there was no significant difference in the intensity of C. forsteri eggs between the gill arches (F = 3.43, d.f. = 2, P > 0.05), or at different depth of sectioning (F = 0.08, d.f. = 1.12, P > 0.05). Results suggest that the presence of C. forsteri eggs in the gills of tuna is more likely to be detected by sampling the second gill arch. Furthermore, targeting the middle region and increasing the sectioning depth may reduce the proportion of false negatives