Meal-related increases in vascular reactivity are impaired in older and diabetic adults: insights into roles of aging and insulin in vascular flow

A fatty meal induces vasodilatation (of both resting and stimulated forearm flow) in healthy young adults, an effect most likely mediated by the vasodilator actions of insulin. We therefore hypothesized that an impaired meal-related vascular response might be an in vivo marker of vascular insulin resistance, related to the presence of diabetes and/or higher age. Postprandial vascular responses were assessed in three groups of subjects: 15 Type 2 diabetic subjects (age 58 +/- 8 yr), 15 age-, gender-, and body mass index (BMI)-matched older control subjects (age 57 +/- 9 yr), and 15 healthy young control subjects (age 33 +/- 7 yr). Studies were carried out before and 3 and 6 h after a standardized high-fat meal (1,030 kcal, 61 g fat). Forearm microvascular flows were measured by strain gauge plethysmography and large-artery function by ultrasound. Resting blood flow and hyperemic area under curve (AUC) flow were not significantly different in diabetic subjects (resting 117 +/- 42% and AUC 134 +/- 46% of premeal values) compared with age-matched controls (resting 131 +/- 39% and AUC 134 +/- 47%); however, the response in diabetic subjects was blunted compared with young controls (resting 171 +/- 67% and AUC 173 +/- 99% of premeal values; P = 0.02 and P = 0.18, respectively). On multiple regression analysis, we found that increasing age (but not BMI or diabetes) was significantly associated with impaired postprandial vascular responses (resting: r = -0.4, P = 0.002; AUC: r = -0.4, P = 0.006). Therefore, meal ingestion results in impaired vasodilator responses in older nondiabetic and diabetic adults, related to aging rather than insulin resistance.     

Morphological differences among egg nests and adult individuals of Cicadatra persica (Hemiptera,Cicadidae), distributed in Erneh,Syria

The aim of this study is determining the different patterns of egg nests and the morphological differences between the specimens of Cicadatra persica Kirkalidy, 1909 (Hemiptera: Cicadidae) distributed in fruit orchards in Erneh located on AL-Sheikh mountain south west of Syria. The appearance of 80 egg nests was studied, and the results showed that there were two basic patterns of egg nests laid by Cicadatra persica, 90% of the egg nests were of the first pattern (consists of several adjacent slits), while 10% of them were of the second pattern (consists of several divergent slits). A random sample consisting of 300 specimens (150 males and 150 females) were also studied concentrating on the differences in the color of the supra-antennal plate and in the number of spurs on the tibia of the hind legs. The results showed that there were two basic patterns of individuals based on the differences in the color of supra-antennal plate. The first pattern (individuals with yellow supra-antennal plates), constituted more than 90%, and the second one (individuals with black supra-antennal plates) constituted less than 10%. The results also showed that there were 27 different patterns based on the number of spurs on the tibia of the hind legs. One of them was a common pattern (2, 3) whose individuals have 2 spurs on the upper side of the tibia of the hind legs and 3 spurs on the lateral side of the tibia of the hind legs. The total percent of this common pattern was 76%. The other 26 patterns were different from each other, and the total percent of all these different patterns was 24%.     

Collagenase predigestion on paraffin sections enhances collagen immunohistochemical detection without distorting tissue morphology

Reliable immunohistochemical detection of collagen in formalin fixed, paraffin embedded tissues requires protease digestion. While these pan-proteases (pepsin, trypsin, protease K, etc.) enhance collagen detection, they also digest many other tissue proteins and produce poor cellular morphology and unrecognizable cellular structures. Balancing the conditions (protease type, concentration, incubation time and temperature) to digest some, but not all, proteins in a tissue section while optimizing collagen detection requires one to compromise improved collagen immunolabeling with adequate cellular morphology. Furthermore, optimal conditions for digesting tissue proteins to enhance collagen detection vary among tissue types and their fixation. Although brain is not typically subject to these deleterious consequences, structures such as epithelium, spermatids, stroma etc. and other tissues with complicated histology are profoundly affected. To resolve this technical dilemma, we discovered a novel use for collagenase to enhance collagen immunodetection without affecting the noncollagen proteins, thereby preserving tissue morphology. Collagenase, which is typically used in vitro for disassociation of cells, has never been used reliably on formalin fixed, paraffin embedded tissue sections. This new use of collagenase for immunohistochemistry promotes increased collagen immunolabeling, is easy to use, is versatile, and allows preservation of tissue structure that provides maximal and accurate histological information.     

Evaluation of a high resolution genotyping method for Chlamydia trachomatis using routine clinical samples

Background

Genital chlamydia infection is the most commonly diagnosed sexually transmitted infection in the UK. C. trachomatis genital infections are usually caused by strains which fall into two pathovars: lymphogranuloma venereum (LGV) and the genitourinary genotypes D–K. Although these genotypes can be discriminated by outer membrane protein gene (ompA) sequencing or multi-locus sequence typing (MLST), neither protocol affords the high-resolution genotyping required for local epidemiology and accurate contact-tracing.

Principal Findings

We evaluated variable number tandem repeat (VNTR) and ompA sequencing (now called multi-locus VNTR analysis and ompA or “MLVA-ompA”) to study local epidemiology in Southampton over a period of six months. One hundred and fifty seven endocervical swabs that tested positive for C. trachomatis from both the Southampton genitourinary medicine (GUM) clinic and local GP surgeries were tested by COBAS Taqman 48 (Roche) PCR for the presence of C. trachomatis. Samples tested as positive by the commercial NAATs test were genotyped, where possible, by a MLVA-ompA sequencing technique. Attempts were made to isolate C. trachomatis from all 157 samples in cell culture, and 68 (43%) were successfully recovered by repeatable passage in culture. Of the 157 samples, 93 (i.e. 59%) were fully genotyped by MLVA-ompA. Only one mixed infection (E & D) in a single sample was confirmed. There were two distinct D genotypes for the ompA gene. Most frequent ompA genotypes were D, E and F, comprising 20%, 41% and 16% of the type-able samples respectively. Within all genotypes we detected numerous MLVA sub-types.

Conclusions

Amongst the common genotypes, there are a significant number of defined MLVA sub-types, which may reflect particular background demographics including age group, geography, high-risk sexual behavior, and sexual networks.     

Genome sequence of the zoonotic pathogen Chlamydophila psittaci

We present the first genome sequence of Chlamydophila psittaci, an intracellular pathogen of birds and a human zoonotic pathogen. A comparison with previously sequenced Chlamydophila genomes shows that, as in other chlamydiae, most of the genome diversity is restricted to the plasticity zone. The C. psittaci plasmid was also sequenced.     

Identification to the species level of <Emphasis Type="Italic">Lactobacillus</Emphasis> isolated in probiotic prospecting studies of human,animal or food origin by 16S-23S rRNA restriction profiling

Background  

The accurate identification of Lactobacillus and other co-isolated bacteria during microbial ecological studies of ecosystems such as the human or animal intestinal tracts and food products is a hard task by phenotypic methods requiring additional tests such as protein and/or lipids profiling.     

Investigation of apoptosis in cultured cells infected with equine herpesvirus 1

Many viruses alter different stages of apoptosis of infected cells as a strategy for successful infection. Few studies have addressed mechanisms of equine herpesvirus 1 (EHV-1) strain-induced cell death. We investigated the effect of an abortigenic strain (AR8 strain) on heterologous Madin–Darby bovine kidney cells and homologous equine dermis (ED) cells cell lines. We compared morphologic and biochemical features of early and late apoptosis at different postinfection times. We investigated translocation of phosphatidylserine to the cell surface, nuclear fragmentation and changes in the cytoskeleton using flow cytometry and annexin V/propidium iodide staining, DNA laddering, terminal deoxynucleotidyl transferase UTP nick-end labeling assay and immunofluorescence staining of cytokeratin 18 cleavage. AR8 EVH-1 strain interfered with apoptosis in both cell lines, particularly during the middle stage of the replication cycle; this was more evident in ED cells. Although this antiapoptotic effect has been reported for other alpha herpesviruses, our findings may help elucidate how EHV-1 improves its infectivity during its cycle.