Highly resolving two-dimensional gels for protein sequencing.

Two-dimensional (2D) PAGE, using carrier ampholytes for the first-dimension separation, has provided a tool for the simultaneous analysis of cellular proteins. To extend the utility of 2D PAGE to the preparative level, we have investigated the use of immobilized pH gradients (IPG) for the first-dimension separation. The results we have obtained indicate that as much as 1 mg of cellular protein can be loaded onto a single IPG gel without loss of resolution. Mutant polypeptides previously detected in carrier ampholyte-based 2D gels were equally detectable in IPG-based 2D gels. With IPG gels several hundred cellular polypeptides can be isolated, from as few as 10 gels, in sufficient amount for sequencing with current sequencing technology. We therefore conclude that IPG greatly enhances the prospects for the large-scale sequencing of cellular proteins for the development of 2D gel-related protein data bases and for the identification of new polypeptide gene products, with the attendant implications for a genome sequencing effort.     

Xenophagy in Helicobacter pylori‐ and Epstein–Barr virus‐induced gastric cancer

Helicobacter pylori and Epstein–Barr virus (EBV) account for roughly 80% and 10%, respectively, of gastric carcinomas worldwide. Autophagy is an evolutionarily conserved and intricately regulated cellular process that involves the sequestration of cytoplasmic proteins and organelles into double‐membrane autophagosomes that eventually fuse with lysosomes for degradation of the engulfed content. Emerging evidence indicates that xenophagy, a form of selective autophagy, plays a crucial role in the pathogenesis of H. pylori‐ and EBV‐induced gastric cancer. Xenophagy specifically recognizes intracellular H. pylori and EBV and physically targets these pathogens to the autophagosomal–lysosomal pathway for degradation. In this connection, H. pylori or EBV‐induced dysregulation of autophagy may be causally linked to gastric tumourigenesis and therefore can be exploited as therapeutic targets. This review will discuss how H. pylori and EBV infection activate autophagy and how these pathogens evade recognition and degradation by the autophagic pathway. Elucidating the molecular aspects of H. pylori‐ and EBV‐induced autophagy will help us better understand the pathogenesis of gastric cancer and promote the development of autophagy modulators as antimicrobial agents. Published by John Wiley & Sons, Ltd     

Living in uncertain times: trajectories to death in residential care homes

Background

Older people living in care homes often have limited life expectancy. Practitioners and policymakers are increasingly questioning the appropriateness of many acute hospital admissions and the quality of end-of-life care provided in care homes.

Aim

To describe care home residents’ trajectories to death and care provision in their final weeks of life.

Design and setting

Prospective study of residents in six residential care homes in three sociodemographically varied English localities: Hertfordshire, Essex, and Cambridgeshire.

Method

Case note reviews and interviews with residents, care home staff, and healthcare professionals.

Results

Twenty-three out of 121 recruited residents died during the study period. Four trajectories to death were identified: ‘anticipated dying’ with an identifiable end-of-life care period and death in the care home (n = 9); ‘unexpected dying’ with death in the care home that was not anticipated and often sudden (n = 3); ‘uncertain dying’ with a period of diagnostic uncertainty or difficult symptom management leading to hospital admission and inpatient death (n = 7); and ‘unpredictable dying’ with an unexpected event leading to hospital admission and inpatient death (n = 4). End-of-life care tools were rarely used. Most residents who had had one or more acute hospital admission were still alive at the end of the study.

Conclusion

For some care home residents there was an identifiable period when they were approaching the end-of-life and planned care was put in place. For others, death came unexpectedly or during a period of considerable uncertainty, with care largely unplanned and reactive to events.     

Telomere length assessment in human archival tissues: combined telomere fluorescence in situ hybridization and immunostaining

A method was developed to assess human telomere lengths at the individual cell level in tissue sections from standard formalin-fixed paraffin-embedded tissues. We coupled this method with immunofluorescence to allow the simultaneous identification of specific cell types. Validation of this in situ quantification method showed excellent agreement with the commonly used telomere repeat fragment-Southern blot method. The assay requires very few cells ( approximately 10 to 15). Thus, small tissue samples, including clinical biopsies, can be easily accommodated. In addition, the cells under study need not be actively cycling and there is no requirement for tissue disaggregation or cell culture. This method provides a more accurate assessment of telomere lengths than Southern blotting because confounding contributions from undesired cell types within tissue samples are avoided. Using this technique, we were able to perform the first comparison of relative telomere lengths in matched tumor versus normal epithelial cells within archival human prostate tissues.     

STAT-3 overexpression and p21 up-regulation accompany impaired regeneration of fatty livers

Fatty liver is an important cause of morbidity in humans and is linked to impaired liver regeneration after liver injury, but the mechanisms for impaired liver regeneration remain unknown. In the normal liver, the interleukin (IL)-6/STAT-3 pathway is thought to play a central role in regeneration because this pathway is disrupted in IL-6-deficient mice that exhibit impaired liver regeneration after 70% partial hepatectomy (PH). To determine whether inhibition of STAT-3 is involved in fatty liver-related mitoinhibition, regenerative induction of STAT-3 was compared in normal mice and leptin-deficient ob/ob mice that have fatty livers and markedly impaired liver regeneration after PH. In both groups, two waves of STAT-3 activation were observed, the first in endothelia and the second in hepatocytes. Before PH, a significantly higher percentage of ob/ob endothelial and hepatocyte nuclei expressed phosphorylated (activated) STAT-3. After PH, phospho-STAT-3 accumulated in liver nuclei of lean mice and this response was markedly exaggerated in ob/ob mice. Moreover, a striking inverse correlation was noted between hepatocyte nuclear accumulation of phospho-STAT-3 and DNA synthesis (as assessed by bromodeoxyuridine labeling), as well as cyclin D1 mRNA induction and protein expression. In contrast, STAT-3 activation was positively correlated with p21 protein expression in both groups of mice. Because these results link exaggerated STAT-3 activation with impaired hepatocyte proliferation, STAT-3 inhibition cannot be a growth-arrest mechanism in ob/ob fatty livers. Rather, hyperinduction of this factor may promote mitoinhibition by up-regulating mechanisms that impede cell cycle progression.     

Detection of Rickettsia felis in a New World flea species, Anomiopsyllus nudata (Siphonaptera: Ctenophthalmidae)

The flea and rodent samples studied in this project were collected from field study sites in New Mexico from winter 1998 to spring 2001. During this period, 155 small rodents (14 different species) were live-trapped and combed for the presence of fleas. A total of 253 fleas were collected, comprising 21 species. Two of the 253 fleas collected were polymerase chain reaction (PCR) positive for the Rickettsia 17-kDa protein gene. These two fleas were both Anomiopsyllus nudata Baker, each collected from an individual Neotoma albigula Hartley, on two occasions. Individual fleas positive for the Rickettsia 17-kDa protein gene were then tested with primers targeting the rickettsial genes for citrate synthase (gltA) and two major outer membrane proteins (ompA and ompB). The nucleotide sequences of the PCR products of these two fleas were identical to each other and were 100% (394/394), 100% (1150/1150), 99.8% (469/470), and 99.3% (818/824) similar to the corresponding sequences of the 17-kDa, gltA, ompA, and ompB genes of Rickettsia felis, respectively. Flea homogenates of individual PCR-positive fleas were inoculated into shell vials seeded with Vero cells, and the Gimenez stain technique was used to demonstrate the presence of Rickettsia-like organisms in detached cells found in aspirated medium 19 d after inoculation. These cells were harvested and tested by PCR, targeting portions of the 17-kDa and gltA genes, resulting in products 100% identical to R. felis. This work comprises the first report of R. felis detection in a flea species (A. nudata) endemic to the New World.     

Effects of voluntary exercise on synaptic plasticity and gene expression in the dentate gyrus of adult male Sprague-Dawley rats in vivo

We have previously shown that voluntary exercise produces enhanced neurogenesis and long-term potentiation (LTP) in the dentate gyrus (DG) of mice in vitro. In the present experiments we show that rats given access to a running wheel (Runners) exhibit significantly more short-term potentiation and LTP with theta-patterned conditioning stimulation in vivo than do age-matched litter mates (Controls). This increase in LTP appears to reflect an alteration in the induction threshold for synaptic plasticity that accompanies voluntary exercise. Weak theta-patterned stimulation, which did not produce LTP in control subjects, produced a robust and long-lasting LTP in Runners. LTP induction in both groups was dependent upon the activation of N-methyl-D-aspartate (NMDA) receptors, and could be blocked by the competitive antagonist [+/-]-3-[2-carboxypiperazin-4-yl] propanephosphonic acid. Consistent with these findings, we found that mRNA levels for NR2B subtype of NMDA receptor were increased specifically in the DG of Runners. In addition to changes in NR2B mRNA levels, quantitative polymerase chain reaction analysis revealed that brain-derived neurotrophic factor (BDNF) and glutamate receptor 5 mRNA levels were also significantly elevated in the DG of Runners, but not in other areas of the hippocampus. Thus, alterations in the expression of BDNF, and specific glutamate receptor subtypes, may underlie the ability of exercise to enhance neurogenesis and reduce the threshold for LTP in the DG.     

Acceptability of self-collected versus provider-collected sampling for HPV DNA testing among women in rural El Salvador

Objective

To determine the acceptability of self-collected versus provider-collected sampling among women participating in public sector HPV-based cervical cancer screening in El Salvador.

Methods

Two thousand women aged 30–49 years underwent self-collected and provider-collected sampling with careHPV between October 2012 and March 2013 (Qiagen, Gaithersburg, MD, USA). After sample collection, a random sample of women (n = 518) were asked about their experience. Participants were questioned regarding sampling method preference, previous cervical cancer screening, HPV and cervical cancer knowledge, HPV risk factors, and demographic information.

Results

All 518 women approached to participate in this questionnaire study agreed and were enrolled, 27.8% (142 of 511 responding) of whom had not received cervical cancer screening within the past 3 years and were considered under-screened. Overall, 38.8% (n = 201) preferred self-collection and 31.9% (n = 165) preferred provider collection. Self-collection preference was associated with prior tubal ligation, HPV knowledge, future self-sampling preference, and future home-screening preference (P < 0.05). Reasons for self-collection preference included privacy/embarrassment, ease, and less pain; reasons cited for provider-collection preference were result accuracy and provider knowledge/experience.

Conclusion

Self-sampling was found to be acceptable, therefore screening programs could consider offering this option either in the clinic or at home. Self-sampling at home may increase coverage in low-resource countries and reduce the burden that screening places upon clinical infrastructure.