The life history of a colony of Leptotrombidium (Leptotrombidium) fletcheri (Womersley & Heaslip) infected with Rickettsia tsutsugamushi.

The life cycle of 5 generations of Leptotrombidium (L.) fletcheri infected with Rickettsia tsutsugamushi and reared under ambient temperatures in Malaysia was presented and compared with a colony reared at a constant 27 degrees C (Neal and Barnett, 1961). In general our colony had a longer generation time (average of 54 days from engorged larvae to adult compared with 37 days) and produced fewer eggs (average of 127.9 compared with 900.0) than the comparison colony. Possible factors causing these differences are discussed.     

Rational oral corticosteroid use in adult severe asthma: A narrative review

OCS play an important role in the management of asthma. However, steroid‐related AE are common and represent a leading cause of morbidity. Limited published studies suggest OCS usage varies across countries and recent registry data indicate that at least 25–60% of patients with severe asthma in developed countries may at some stage be prescribed OCS. Recent evidence indicate that many patients do not receive optimal therapy for asthma and are often prescribed maintenance OCS or repeated steroid bursts to treat exacerbations. Given the recent progress in adult severe asthma and new treatment options, judicious appraisal of steroid use is merited. A number of strategies and add‐on therapies are now available to treat severe asthma. These include increasing specialist referral for multidisciplinary assessments and implementing OCS‐sparing interventions, such as improving guideline adherence and add‐on tiotropium and macrolides. Biologics have recently become available for severe asthma; these agents reduce asthma exacerbations and lower OCS exposure. Further research, collaboration and consensus are necessary to develop a structured stewardship approach including realistic OCS‐weaning programmes for patients with severe asthma on regular OCS; education and public health campaigns to improve timely access to specialized severe asthma services for treatment optimization; and implementing targeted strategies to identify patients who warrant OCS use using objective biomarker‐based strategies.     

Structure-Activity–Dependent Regulation of Cell Communication by Perfluorinated Fatty Acids using in Vivo and in Vitro Model Systems

Background

Perfluoroalkanoates, [e.g., perfluorooctanoate (PFOA)], are known peroxisome proliferators that induce hepatomegaly and hepatocarcinogenesis in rodents, and are classic non-genotoxic carcinogens that inhibit in vitro gap-junctional intercellular communication (GJIC). This inhibition of GJIC is known to be a function of perfluorinated carbon lengths ranging from 7 to 10.

Objectives

The aim of this study was to determine if the inhibition of GJIC by PFOA but not perfluoropentanoate (PFPeA) observed in F344 rat liver cells in vitro also occurs in F344 rats in vivo and to determine mechanisms of PFOA dysregulation of GJIC using in vitro assay systems.

Methods

We used an incision load/dye transfer technique to assess GJIC in livers of rats exposed to PFOA and PFPeA. We used in vitro assays with inhibitors of cell signaling enzymes and antioxidants known to regulate GJIC to identify which enzymes regulated PFOA-induced inhibition of GJIC.

Results

PFOA inhibited GJIC and induced hepatomegaly in rat livers, whereas PFPeA had no effect on either end point. Serum biochemistry of liver enzymes indicated no cytotoxic response to these compounds. In vitro analysis of mitogen-activated protein kinase (MAPK) indicated that PFOA, but not PFPeA, can activate the extracellular receptor kinase (ERK). Inhibition of GJIC, in vitro, by PFOA depended on the activation of both ERK and phosphatidylcholine-specific phospholipase C (PC-PLC) in the dysregulation of GJIC in an oxidative-dependent mechanism.

Conclusions

The in vitro analysis of GJIC, an epigenetic marker of tumor promoters, can also predict the in vivo activity of PFOA, which dysregulated GJIC via ERK and PC-PLC.     

What are the responses & needs of mothers of infants diagnosed with congenital heart disease?

This article addresses the needs of families of newborns with congenital heart disease (CHD). Approximately 40,000 infants are born with a congenital heart defect each year; a large percentage survive due to technological advances in treatment, resulting in an increasing number of families who have a child living with a chronic illness. While both parents are significantly affected by a diagnosis of CHD, much of the available literature discusses the experience of mothers. The mother's experiences after learning her child's diagnosis include grief, loss of her imagined healthy child, lack of knowledge of the disease, anger, and difficulty in caregiving, among other issues. Support and encouragement at the time of diagnosis and throughout each stage of the illness are essential. This article describes various strategies that nurses can use to assist these families through their difficult journey.