Periarteriolar spaces modulate cerebrospinal fluid transport into brain and demonstrate altered morphology in aging and Alzheimer's disease.

Perivascular spaces (PVS) drain brain waste metabolites, but their specific flow paths are debated. Meningeal pia mater reportedly forms the outermost boundary that confines flow around blood vessels. Yet, we show that pia is perforated and permissive to PVS fluid flow. Furthermore, we demonstrate that pia is comprised of vascular and cerebral layers that coalesce in variable patterns along leptomeningeal arteries, often merging around penetrating arterioles. Heterogeneous pial architectures form variable sieve-like structures that differentially influence cerebrospinal fluid (CSF) transport along PVS. The degree of pial coverage correlates with macrophage density and phagocytosis of CSF tracer. In vivo imaging confirms transpial influx of CSF tracer, suggesting a role of pia in CSF filtration, but not flow restriction. Additionally, pial layers atrophy with age. Old mice also exhibit areas of pial denudation that are not observed in young animals, but pia is unexpectedly hypertrophied in a mouse model of Alzheimer's disease. Moreover, pial thickness correlates with improved CSF flow and reduced ß-amyloid deposits in PVS of old mice. We show that PVS morphology in mice is variable and that the structure and function of pia suggests a previously unrecognized role in regulating CSF transport and amyloid clearance in aging and disease.

Study of the use of axial viewed inductively coupled plasma atomic emission spectrometry with ultrasonic nebulization for the determination of select elemental impurities in oral drug products.

In efforts to control the potential presence of heavy metals in pharmaceuticals, the United States Pharmacopeia (USP) and International Conference on Harmonization (ICH) have put forth new requirements and guidelines for their control. The new requirements and guidelines establish specific daily exposures (PDE) for 24 heavy metals/elemental impurities (EI) based upon their toxicological properties. USP General Chapter 〈233〉 provides a general reference procedure for preparing pharmaceutical samples for analysis employing microwave assisted digestion (MWAD). It also provides two Compendial Procedures, Procedure 1 employing ICP-AES, and Procedure 2 employing ICP-MS. Given the extremely low detection limits afforded by ICP-MS, much work has been done in developing and evaluating analytical methods to support the analysis of elemental impurities in finished pharmaceutical products, active pharmaceutical ingredients, and excipients by this analytical technique. In this study, we have evaluated the use of axial ICP-AES. This employs ultrasonic nebulization (UN) for the determination of Class 1 and 2 EI, instead of traditional pneumatic nebulization. The study also employed closed vessel MWAD to prepare samples for analysis. Limits of quantitation were element specific and significantly lower than the PDEs for oral drugs. Spike recoveries for the elements studied ranged between 89.3% and 109.25%, except for Os, which was subject to OsO4 formation during MWAD. The use of axial ICP-AES UN provides an alternative to ICP-MS in the analysis of EI requiring low detection limits.

Hepatitis E infection during pregnancy.

QUESTION: Many of my patients are from Southeast Asia where hepatitis E virus (HEV) infection is quite common. What precautions can I suggest they take before traveling to these areas and what is the risk of contracting HEV during pregnancy? ANSWER: Hepatitis E is a water-borne pathogen transmitted by the fecal-oral route. To reduce the risk of contracting HEV while traveling to endemic areas, it is important to maintain hygienic practices such as hand washing with safe water, particularly before handling food, avoiding drinking water or using ice cubes of unknown purity, and avoiding eating unpeeled fruits and vegetables. Currently there is no vaccine available in Canada for HEV. Hepatitis E infection during pregnancy, especially in the third trimester, is characterized by a more severe infection that sometimes results in fulminant hepatitis, increasing maternal and fetal mortality and morbidity.

Probiotics for infantile colic: a randomized, double-blind, placebo-controlled trial investigating Lactobacillus reuteri DSM 17938.

OBJECTIVE: To investigate the effectiveness of Lactobacillus reuteri DSM 17938 for the treatment of infantile colic in breastfed Canadian infants, compared with placebo. STUDY DESIGN: A randomized, double-blind, placebo-controlled trial was conducted involving 52 infants with colic, according to modified Wessel criteria, who were assigned at random to receive L reuteri DSM 17938 (10(8) colony-forming units) (n = 24) or placebo (n = 28) for 21 days. Daily crying and fussing times were recorded in a structured diary, and maternal questionnaires were completed to monitor changes in infant colic symptoms and adverse events. RESULTS: Total average crying and fussing times throughout the study (from baseline to day 21) were significantly shorter among infants with colic in the probiotic group compared with infants in the placebo group (1719 ± 750 minutes [29 ± 13 hours] vs 2195 ± 764 minutes [37 ± 13 hours]; P = .028) (relative risk, 0.78; 95% CI, 0.58-0.98). Infants given L reuteri DSM 17938 showed a significant reduction in daily crying and fussing times at the end of treatment period compared with those receiving placebo (median, 60 minutes/day [IQR, 64 minutes/day] vs 102 minutes/day [IQR, 87 minutes/day]; P = .045). On day 21, a significantly higher proportion of infants in the L reuteri DSM 17938 group responded to treatment with a ≥50% crying time reduction compared with infants given placebo (17 vs 6, P = .035; relative risk, 3.3; 95% CI, 1.55-7.03). CONCLUSION: Administration of L reuteri DSM 17938 significantly improved colic symptoms by reducing crying and fussing times in breastfed Canadian infants with colic.

Topical prophylaxis for HIV prevention in women: becoming a reality.

Strategies to protect against sexual transmission of HIV include the development of products formulated for topical application, which limit the toxicities associated with systemic oral pre-exposure prophylaxis. Following several clinical trial failures, attention is now focused on antiretroviral (ARV) agents. Highly potent ARV topical formulations provide a female-controlled, targeted, and feasible option for HIV prevention. A recently completed tenofovir gel trial was the first to demonstrate significant protection against HIV acquisition. Topical ARVs have the advantage of delivering high concentration of drug at the site of transmission of HIV, with low systemic absorption. Sustained-release formulations, such as intravaginal rings, will likely improve adherence and can be designed to provide controlled and continuous delivery of ARV combinations. Further studies to test alternative dosing strategies and pharmacokinetic/pharmacodynamic relationships in the genital tract will provide valuable information as the field strives to improve upon the promising tenofovir gel trial results.

Increased activity of Coxsackievirus B1 strains associated with severe disease among young infants in the United States, 2007-2008.

BACKGROUND: Enterovirus infections are very common and typically cause mild illness, although neonates are at higher risk for severe illness. In 2007, the Centers for Disease Control and Prevention (CDC) received multiple reports of severe neonatal illness and death associated with coxsackievirus B1 (CVB1), a less common enterovirus serotype not previously associated with death in surveillance reports to the CDC. METHODS: This report includes clinical, epidemiologic, and virologic data from cases of severe neonatal illness associated with CVB1 reported during the period from 2007 through 2008 to the National Enterovirus Surveillance System (NESS), a voluntary, passive surveillance system. Also included are data on additional cases reported to the CDC outside of the NESS. Virus isolates or original specimens obtained from patients from 25 states were referred to the CDC picornavirus laboratory for molecular typing or characterization. RESULTS: During 2007-2008, the NESS received 1079 reports of enterovirus infection. CVB1 accounted for 176 (23%) of 775 reported cases with known serotype, making it the most commonly reported serotype for the first time ever in the NESS. Six neonatal deaths due to CVB1 infection were also reported to the CDC during that time. Phylogenetic analysis of the 2007 and 2008 CVB1 strains indicated that the increase in cases resulted from widespread circulation of a single genetic lineage that had been present in the United States since at least 2001. CONCLUSIONS: Healthcare providers and public health departments should be vigilant to the possibility of continuing CVB1-associated neonatal illness, and testing and continued reporting of enterovirus infections should be encouraged.

Outbreak of life-threatening coxsackievirus B1 myocarditis in neonates.

In the summer and fall of 2007, we observed a unique cluster of cases of severe coxsackievirus B1 (CVB1) infection among Chicago area neonates. Eight neonates had closely related strains of CVB1 that were typed at the Centers of Disease Control and Prevention; 2 other neonates had CVB infections, 1 of which was further identified as serotype CVB1. All had severe myocarditis; 1 neonate underwent heart transplantation, and 1 died of severe left ventricular dysfunction.