Examining self and partners for syphilis among men who have sex with men: five US cities, 2009-2011

To increase self-examination for syphilis among men who have sex with men (MSM), we developed educational materials to increase knowledge of primary and secondary syphilis manifestations. Materials were piloted in five cities' infectious disease or MSM clinics. Self- and partner-examination behaviour was assessed with an anonymous questionnaire. Of 1459 participants, 914 men had had sex with a man in the previous three months; the 171 MSM who reported having read the materials were significantly more likely to examine themselves (anus, adjusted prevalence ratio [aPR] 1.3, 95% confidence interval [CI] 1.15-1.52), mouth, penis and skin, and their partners' anus (aPR 1.3, 95% CI 1.03-1.73) and mouth (aPR 1.6, 95% CI 1.1-2.26). Further research is needed to determine whether educational materials affect early detection and treatment of primary and secondary syphilis and reduce transmission.

Analysis of K-ras gene mutations in human pancreatic cancer cell lines and in bile samples from patients with pancreatic and biliary cancers

The ras family of oncogenes are the most frequently activated group of dominant transforming genes in both human and experimental cancers. The ras family of genes encode highly similar proteins with molecular weights of 21 kDa which are thought to play a key role in signal transduction. Activation in vivo by point mutations results in the ras p21 protein being maintained in the activated form and stimulating cellular proliferation autonomously. Point mutations at codon 12 of K-ras have been observed in >75% of cases of adenocarcinomas of the exocrine pancreas. The type and frequency of K-ras gene mutations in pancreatic cancer cell lines and in bile samples from patients with cytologically-proven biliary tract malignancies and from patients with non-malignant disorders of the biliary tract were determined. Codons 12, 13 and 61 of the K-ras gene were analysed by using restriction fragment length polymorphisms created through mismatched primers during polymerase chain reaction (PCR) of genomic DNA. A mutation of codon 12 of K-ras was detected in 10 of 13 (77%) human pancreatic cancer cell lines. The amino-acid substitutions were glycine to aspartate (5 samples), arginine (2), valine (2) and cysteine (1). No mutations were found at codons 13 or 61. A mutation at codon 12 of K-ras was detected in 9 of 18 (50%) of bile samples analysed. Eleven bile samples had positive cytology for malignancy of pancreaticobiliary origin, and 4 (36%) of these had a codon 12 mutation. Mutations were detected in 5 of the 7 (71%) cytologically-negative bile samples, although malignancy was subsequently diagnosed in 2 of these patients on further histology, and was suspected in 3 other cases on clinical and radiological criteria. This method provides a rapid determination of K-ras gene mutations in bile samples for patients with pancreatic and biliary tract diseases, which may be useful when considering future therapy directed at inhibition of activated ras-induced signal transduction pathways.

Unintended diagnosis of Von Hippel Lindau syndrome using Array Comparative Genomic Hybridization (CGH): counseling challenges arising from unexpected information

Array Comparative Genomic Hybridization (array CGH) is a powerful tool for identifying genomic imbalances and providing a diagnosis in individuals with a normal karyotype. It has been particularly useful in the investigation of individuals with developmental delay +/-, dysmorphic features and/or multiple congenital abnormalities. However, this non-targeted method of scanning the whole genome can reveal unexpected information. We present a case where array CGH identified the cause of a proband's moderate mental retardation by discovery of a de novo deletion of chromosome 3p25.3. This deletion was shown to contain at least 25 genes including the VHL gene, the deletion or mutation of which leads to Von Hippel Lindau (VHL) syndrome. Presymptomatic testing for VHL is usually offered after appropriate genetic counseling about the implications of this condition. Therefore, scanning the genome by array CGH presents a number of challenges for the genetic counselor. We suggest that further understanding of the psychosocial effects of array CGH is needed in order for appropriate pre- and post-test counseling to be provided.

Alternative immunomodulatory strategies for xenotransplantation: CD40/154 pathway-sparing regimens promote xenograft survival

Immunosuppressive therapies that block the CD40/CD154 costimulatory pathway have proven to be uniquely effective in preclinical xenotransplant models. Given the challenges facing clinical translation of CD40/CD154 pathway blockade, we examined the efficacy and tolerability of CD40/CD154 pathway-sparing immunomodulatory strategies in a pig-to-nonhuman primate islet xenotransplant model. Rhesus macaques were rendered diabetic with streptozocin and given an intraportal infusion of ≈ 50 000 islet equivalents/kg wild-type neonatal porcine islets. Base immunosuppression for all recipients included maintenance therapy with belatacept and mycophenolate mofetil plus induction with basiliximab and LFA-1 blockade. Cohort 1 recipients (n = 3) were treated with the base regimen alone; cohort 2 recipients (n = 5) were additionally treated with tacrolimus induction and cohort 3 recipients (n = 5) were treated with alefacept in place of basiliximab, and more intense LFA-1 blockade. Three of five recipients in both cohorts 2 and 3 achieved sustained insulin-independent normoglycemia (median rejection-free survivals 60 and 111 days, respectively), compared to zero of three recipients in cohort 1. These data show that CD40/CD154 pathway-sparing regimens can promote xenoislet survival. Further optimization of these strategies is warranted to aid the clinical translation of islet xenotransplantation.

Whole-exome sequencing and an iPSC-derived cardiomyocyte model provides a powerful platform for gene discovery in left ventricular hypertrophy

Rationale: Left ventricular hypertrophy (LVH) is a heritable predictor of cardiovascular disease, particularly in blacks. Objective: Determine the feasibility of combining evidence from two distinct but complementary experimental approaches to identify novel genetic predictors of increased LV mass. Methods: Whole-exome sequencing (WES) was conducted in seven African-American sibling trios ascertained on high average familial LV mass indexed to height (LVMHT) using Illumina HiSeq technology. Identified missense or nonsense (MS/NS) mutations were examined for association with LVMHT using linear mixed models adjusted for age, sex, body weight, and familial relationship. To functionally assess WES findings, human induced pluripotent stem cell-derived cardiomyocytes (induced pluripotent stem cell-CM) were stimulated to induce hypertrophy; mRNA sequencing (RNA-seq) was used to determine gene expression differences associated with hypertrophy onset. Statistically significant findings under both experimental approaches identified LVH candidate genes. Candidate genes were further prioritized by seven supportive criteria that included additional association tests (two criteria), regional linkage evidence in the larger HyperGEN cohort (one criterion), and publically available gene and variant based annotations (four criteria). Results: WES reads covered 91% of the target capture region (of size 37.2 MB) with an average coverage of 65×. WES identified 31,426 MS/NS mutations among the 21 individuals. A total of 295 MS/NS variants in 265 genes were associated with LVMHT with q-value <0.25. Of the 265 WES genes, 44 were differentially expressed (P < 0.05) in hypertrophied cells. Among the 44 candidate genes identified, 5, including HLA-B, HTT, MTSS1, SLC5A12, and THBS1, met 3 of 7 supporting criteria. THBS1 encodes an adhesive glycoprotein that promotes matrix preservation in pressure-overload LVH. THBS1 gene expression was 34% higher in hypertrophied cells (P = 0.0003) and a predicted conserved and damaging NS variant in exon 13 (A2099G) was significantly associated with LVHMT (P = 4 × 10⁻⁶). Conclusion: Combining evidence from cutting-edge genetic and cellular experiments can enable identification of novel LVH risk loci.

Sexual dimorphism in intra- and interspecific competitive ability of the dioecious herb Mercurialis annua

Males and females of dioecious plant species often show different responses to competition with individuals of the same or opposite gender, but almost no data are available on the outcome of competition with members of other species. Here, we show that male and female individuals of the wind-pollinated herb Mercurialis annua are sexually dimorphic in both their intraspecific and interspecific competitive abilities. In a controlled experiment, we found that both sexes of M. annua were negatively affected by interspecific competition, but the sensitivity of males and females depended on the identity of their competitor species, with females tending to suppress the aboveground growth of competitor species more than males. Further, we found that intrasexual and intersexual competition affected the aboveground growth of males but not that of females: only males showed a significant reduction in growth when growing with conspecific competitors (male or female). We discuss our results with reference to related studies that suggest that males and females of M. annua have different resource requirements for reproduction, which in turn affect their competitive abilities.

STING: a soft-tissue intervention and neurosurgical guide to access deep brain lesions through curved trajectories

Current trends in surgical intervention favour a minimally invasive approach, in which complex procedures are performed through very small incisions. Specifically, in neurosurgery there is a need for minimally invasive keyhole access, which conflicts with the lack of manoeuvrability of conventional rigid instruments. In an attempt to address this shortcoming, the current state of progress is reported on a soft-tissue intervention and neurosurgical guide (STING) to access deep brain lesions through curved trajectories. The underlying mechanism of motion, based on the reciprocal movement of interlocked probe segments, is biologically inspired and was designed around the unique features of the ovipositor of certain parasitic wasps. Work to date has focused on probe development, low- and high-level control, and trajectory planning. These aspects are described, together with results on each aspect of the work, including biomimetic microtexturing of the probe surface. Progress is very encouraging and demonstrates that forward motion into soft tissue through a reciprocating mechanism is indeed viable and can be achieved through a suitable combination of microtexturing and microfabrication techniques.