Citations

Aberrant connectivity is implicated in many neurological and psychiatric disorders, including Alzheimer’s disease and schizophrenia. However, other than a few disease-associated candidate genes, we know little about the degree to which genetics play a role in the brain networks; we know even less about specific genes that influence brain connections. Twin and family-based studies can generate estimates of overall genetic influences on a trait, but genome-wide association scans (GWASs) can screen the genome for specific variants influencing the brain or risk for disease. To identify the heritability of various brain connections, we scanned healthy young adult twins with high-field, high-angular resolution diffusion MRI. We adapted GWASs to screen the brain’s connectivity pattern, allowing us to discover genetic variants that affect the human brain’s wiring. The association of connectivity with the SPON1 variant at rs2618516 on chromosome 11 (11p15.2) reached connectome-wide, genome-wide significance after stringent statistical corrections were enforced, and it was replicated in an independent subsample. rs2618516 was shown to affect brain structure in an elderly population with varying degrees of dementia. Older people who carried the connectivity variant had significantly milder clinical dementia scores and lower risk of Alzheimer’s disease. As a posthoc analysis, we conducted GWASs on several organizational and topological network measures derived from the matrices to discover variants in and around genes associated with autism ( MACROD2 ), development ( NEDD4 ), and mental retardation ( UBE2A ) significantly associated with connectivity. Connectome-wide, genome-wide screening offers substantial promise to discover genes affecting brain connectivity and risk for brain diseases.

Background and PurposeAlternative splicing expands proteome diversity toGPCRs. Distinct receptor variants have been identified for a secretin familyGPCR, the calcitonin receptor (CTR). The possible functional contributions of these receptor variants are further altered by their potential interactions with receptor activity‐modifying proteins (RAMPs). One variant of the humanCTRlacks the first 47 residues at itsNterminus [Δ(1–47)hCT(a)]. However, very little is known about the pharmacology of this variant or its ability to interact withRAMPsto form amylin receptors.Experimental ApproachΔ(1–47)hCT(a)was characterized both with and withoutRAMPsinCos7and/orHEK293Scells. The receptor expression (ELISAassays) and function (cAMPandpERK1/2 assays) for up to six agonists and two antagonists were determined.Key ResultsDespite lacking 47 residues at theNterminus, Δ(1–47)hCT(a)was still able to express at the cell surface, but displayed a generalized reduction in peptide potency. Δ(1–47)hCT(a)retained its ability to interact withRAMP1and formed a functional amylin receptor; this also appeared to be the case withRAMP3. On the other hand, its interaction withRAMP2and resultant amylin receptor was reduced to a greater extent.Conclusions and ImplicationsΔ(1–47)hCT(a)acts as a functional receptor at the cell surface. It exhibits altered receptor function, depending on whether it associates with aRAMPand whichRAMPit interacts with. Therefore, the presence of this variant in tissues will potentially contribute to altered peptide binding and signalling, depending on theRAMPdistribution in tissues.

Application of hemodialysis to dogs has been complicated by an acute reaction consisting of hypotension, bradycardia and respiratory depression followed by instability and a mortality rate of about 30 per cent. This reaction appears to be a response to homologous blood used to fill the dialyzers. Sensitization occurs in survivors, and accentuated reactions with marked hemolysis are noted on subsequent challenge. Cross matching the donor and recipient bloods has not permitted an adequate determination of compatibility under the conditions of hemodialysis. Satisfactory hemodialysis may be accomplished in dogs by using autogenous blood or blood substitutes to fill the dialyzers.

ABSTRACT Introduction Erectile dysfunction (ED) may be the most commonly observed adverse event (AE) associated with the combination of radiation therapy (RT) and androgen deprivation therapy (ADT). A significant number of men are trying phosphodiesterase type 5 inhibitors (PDE5s) such as sildenafil to treat ED, yet sildenafil studies to date shed little light on the response to ED after ADT. Aim The purpose of this trial was to evaluate sildenafil in the treatment of ED in prostate cancer patients previously treated with external beam RT and neoadjuvant and concurrent ADT. Methods In this randomized, double-blinded crossover trial, eligible patients received RT/ADT for intermediate risk prostate cancer and currently had ED as defined by the International Index of Erectile Function (IIEF). Patients were randomized to 12 weeks of sildenafil or placebo followed by 1 week of no treatment then 12 weeks of the alternative. Treatment differences were evaluated using a marginal model for binary crossover data. Main Outcome Measures The primary end point was improved erectile function, as measured by the IIEF. Results The study accrued 115 patients and 61 (55%) completed all three IIEF assessments. Sildenafil effect was significant (P = 0.009) with a difference in probabilities of erectile response of 0.17 (95% confidence interval: 0.06, 0.29), and 0.21 (0.06, 0.38) for patients receiving ≤120 days of ADT. However, as few as 21% of patients had a treatment-specific response, only improving during sildenafil but not during the placebo phase. Conclusions This is the first controlled trial to suggest a positive sildenafil response for ED treatment in patients previously treated with RT/ADT, however, only a minority of patients responded to treatment. ADT duration may be associated with response and requires further study. The overall low response rate suggests the need for study of additional or preventative strategies for ED after RT/ADT for prostate cancer.