Impaired memory CD8 T cell responses against an immunodominant retroviral cryptic epitope

The immunodominant cryptic epitope SYNTGRFPPL, encoded within open reading frame 2 of the LP-BM5 retroviral gag gene, is critical for protection against retroviral-induced pathogenesis. The goal of this study was to dissect the memory response against this unique immunodominant cryptic epitope. Unlike the protective acute effector population of SYNTGRFPPL-specific CD8 T cells, long-lived SYNTGRFPPL-specific CD8 T cells lacked the ability to protect susceptible mice infected with LP-BM5 retrovirus. Compared to memory CD8 T cells against a conventional epitope with similar MHC-I specificity, primed and restimulated using similar conditions, long-lived SYNTGRFPPL-specific CD8 T cells were impaired in their ability to recall against antigen, with reduced cytolytic capabilities and cytokine production. Since similar priming and restimulation regimes were utilized to generate each effector CD8 T cell population, this study has potentially broad implications with regard to the selection criteria of potent, highly conserved cryptic epitopes for use in epitope-based vaccines.     

Safety of Gastric Resections During Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Peritoneal Carcinomatosis

Background  Cytoreductive surgery (CRS) including gastric resection combined with hyperthermic intraperitoneal chemotherapy (HIPEC) can improve the prognosis of selected patients with peritoneal surface malignancies. Perioperative morbidity of this aggressive treatment strategy is high; however, overall mortality can be low in specialized centers. The aim of this study was to assess the safety of gastric resections with anastomosis during CRS and HIPEC. Methods  Between 2005 and 2008, 204 patients underwent CRS and HIPEC at our tertiary referral centre. Of these, 37 procedures (male/female 24/13, median age 55 years) included gastric resections. The clinical data of all patients were introduced into a database and analyzed with respect to the morbidity associated with the gastric resections. Results  Of all patients included, 16 had pseudomyxoma peritonei, 11 gastric carcinoma, 4 ovarian carcinoma, 3 malignant peritoneal mesothelioma, and 3 colon carcinoma. Twenty-seven patients had previous surgery (n = 22) and/or systemic chemotherapy (n = 18). Fifteen total gastrectomies, 3 subtotal gastrectomies, 12 distal gastrectomies, and 7 gastric wedge resections were performed during CRS. The overall postoperative morbidity was 45%; main surgical complications were pancreatitis (n = 6), abdominal abscess (n = 4), bile leakage (n = 2), and digestive fistula (leakage of ileorectostomy and small bowel perforation) (n = 2). However, no complications occurred at the site of the esophageal anastomosis (n = 15), gastric anastomosis (n = 15) or gastric suture (n = 7). No patient died postoperatively during the hospitalization period. Conclusions  CRS in combination with HIPEC is associated with high postoperative morbidity; however, anastomosis following total or subtotal gastrectomy is safe in experienced centers. No leakages related to gastric resections occurred in this high-risk patient group. Pompiliu Piso and Przemyslaw Slowik have contributed equally to this study.     

Amphetamine and mCPP Effects on Dopamine and Serotonin Striatalin vivo Microdialysates in an Animal Model of Hyperactivity

In the neonatally 6-hydroxydopamine (6-OHDA)-lesioned rat hyperlocomotor activity, first described in the 1970s, was subsequently found to be increased by an additional lesion with 5,7-dihydroxytryptamine (5,7-DHT) (i.c.v.) in adulthood. The latter animal model (i.e., 134 microg 6-OHDA at 3 d postbirth plus 71 microg 5,7-DHT at 10 weeks; desipramine pretreatments) was used in this study, in an attempt to attribute hyperlocomotor attenuation by D,L-amphetamine sulfate (AMPH) and m-chlorophenylpiperazine di HCl (mCPP), to specific changes in extraneuronal (i.e., in vivo microdialysate) levels of dopamine (DA) and/or serotonin (5-HT). Despite the 98-99% reduction in striatal tissue content of DA, the baseline striatal microdialysate level of DA was reduced by 50% or less at 14 weeks, versus the intact control group. When challenged with AMPH (0.5 mg/kg), the microdialysate level of DA went either unchanged or was slightly reduced over the next 180 min (i.e., 20 min sampling), while in the vehicle group and 5,7-DHT (alone) lesioned group, the microdialysate level was maximally elevated by approximately 225% and approximately 450%, respectively--and over a span of nearly 2 h. Acute challenge with mCPP (1 mg/kg salt form) had little effect on microdialysate levels of DA, DOPAC and 5-HT. Moreover, there was no consistent change in the microdialysate levels of DA, DOPAC, and 5-HT between intact, 5-HT-lesioned rats, and DA-lesioned rats which might reasonably account for an attenuation of hyperlocomotor activity. These findings indicate that there are other important neurochemical changes produced by AMPH- and mCPP-attenuated hyperlocomotor activity, or perhaps a different brain region or multiple brain regional effects are involved in AMPH and mCPP behavioral actions.     

Modeling tardive dyskinesia: Predictive 5-HT2C receptor antagonist treatment

Tardive dyskinesia (TD), a movement disorder produced by long-term treatment with a classical antipsychotic drug, is generally considered to be a disorder of dopamine (DA) systems, since classical antipsychotics are potent DA D(2) receptor blockers. Also, acute DA D(1) agonist treatment of rats is known to produce vacuous chewing movements (VCMs), a behavioral feature resembling the oral dyskinesia that is so prominent in most instances of TD. In this paper we outline a series of studies in a new animal model of TD in which DA D(1) receptor supersensitivity was produced by neonatal 6-hydroxydopamine (6-OHDA) -induced destruction of nigrostriatal DA fibers. In rats so-lesioned 5-HT receptor supersensitivity is additionally produced, and in fact 5-HT receptor antagonists attenuate enhanced DA D(1) induction of VCMs. Moreover, in 6-OHDA-lesioned rats treated with haloperidol for one year, there a 2-fold increase in numbers of VCMs (vs intact rats treated with haloperidol); and this high frequency of VCMs persists for more than 6 months after discontinuing haloperidol treatment. During this stage, 5-HT(2) receptor antagonists, but not DA D(1) receptor antagonists, attenuate the incidence of VCMs. This series of findings implicates the 5-HT neuronal phenotype in TD, and promotes 5-HT(2) receptor antagonists, more specifically 5-HT(2C) receptor antagonists, as a rational treatment approach for TD in humans.     

c-MYC expression sensitizes medulloblastoma cells to radio- and chemotherapy and has no impact on response in medulloblastoma patients

Background

KLK15 over-expression is reported to be a significant predictor of reduced progression-free survival and overall survival in ovarian cancer. Our aim was to analyse the KLK15 gene for putative functional single nucleotide polymorphisms (SNPs) and assess the association of these and KLK15 HapMap tag SNPs with ovarian cancer survival.

Results

In silico analysis was performed to identify KLK15 regulatory elements and to classify potentially functional SNPs in these regions. After SNP validation and identification by DNA sequencing of ovarian cancer cell lines and aggressive ovarian cancer patients, 9 SNPs were shortlisted and genotyped using the Sequenom iPLEX Mass Array platform in a cohort of Australian ovarian cancer patients (N = 319). In the Australian dataset we observed significantly worse survival for the KLK15 rs266851 SNP in a dominant model (Hazard Ratio (HR) 1.42, 95% CI 1.02-1.96). This association was observed in the same direction in two independent datasets, with a combined HR for the three studies of 1.16 (1.00-1.34). This SNP lies 15bp downstream of a novel exon and is predicted to be involved in mRNA splicing. The mutant allele is also predicted to abrogate an HSF-2 binding site.

Conclusions

We provide evidence of association for the SNP rs266851 with ovarian cancer survival. Our results provide the impetus for downstream functional assays and additional independent validation studies to assess the role of KLK15 regulatory SNPs and KLK15 isoforms with alternative intracellular functional roles in ovarian cancer survival.     

Issues and challenges for development of a sustainable service model for people with spinal cord injury living in rural regions

Middleton JW, McCormick M, Engel S, Rutkowski SB, Cameron ID, Harradine P, Johnson JL, Andrews D. Issues and challenges for development of a sustainable service model for people with spinal cord injury living in rural regions.

Objective

To develop and implement a service model for people with spinal cord injury (SCI) living in rural regions.

Design

Service development, pilot evaluation study.

Setting

Regional and remote areas of the state of New South Wales, Australia.

Participants

Persons with SCI, caregivers, and health professionals.

Intervention

Phase 1 included initial needs analysis, followed by education and resource development tailored to needs of rural health professionals, caregivers, and persons with SCI. Phase 2 included coordination, professional support, and network development by part-time rural key worker and metropolitan-based project officer, documenting health- and service-related issues.

Main Outcome Measures

Self-perception of confidence as a result of education as well as reported issues, adverse health events, and barriers to service provision.

Results

Clinician confidence in managing people with SCI improved after education. Various health-related, environmental, and psychosocial issues were reported. Limited availability of resources and health infrastructure, particularly in more isolated or smaller towns, challenged service provision. Rural key workers played a central role in supporting local clinicians and service providers, improving communication and service coordination between rural health professionals and metropolitan SCI services.

Conclusion

Education and support for rural workforce that may be limited in numbers and capacity, and a model facilitating communication and coordination between services, are essential for improving health outcomes of rural people with SCI.     

Histamine H3 receptor ligands modulate L-dopa-evoked behavioral responses and L-dopa-derived extracellular dopamine in dopamine-denervated rat striatum

To explore a recently established association between histaminergic and dopaminergic neuronal phenotypic systems in brain, we determined the effect of the respective histaminergic H(3) receptor agonist and antagonist/inverse agonist, imetit and thioperamide, on L-DOPA - derived tissue and extracellular DA and metabolite levels in the striatum of 6-hydroxydopamine (6-OHDA) - lesioned rats (i.e., parkinsonian rats). We also examined the influence of histamine H(3) ligands on L-DOPA evoked behavioral responses (locomotor activity, number of rearings, stereotyped behavior and motor coordination). Using HPLC/ED and in vivo microdialysis technique imetit (5 mg/kg, i.p.) but not thioperamide (5 mg/kg, i.p.) was shown to attenuate an L-DOPA-evoked (15 mg/kg, i.p.; carbidopa, 30 min pretreatment) increase in extracellular DA in the neostriatum of 6-OHDA-lesioned rats. However, both imetit and thioperamide increased microdialysate levels of DOPAC and HVA, probably by enhancing intraneuronal DA utilization. As indicated by neurochemical analysis of the striatum imetit produced a decrease in tissue DA content. These findings support the hypothesis that central H(3) histaminergic receptors have a modulatory role in the storage, metabolism and release of DA derived from exogenous L-DOPA challenge. Furthermore, evidence from behavioral studies indicate that histamine H3 receptor blockade markedly improved motor coordination. Conversely, histamine H(3) receptor stimulation, being without effect on motor coordination, enhanced vertical activity in rats. From the above we conclude that the histamine H(3) agonism may augment motor dyskinesia in Parkinson's disease (PD) patients and presumably worsen L-DOPA therapy. Consequently, the histaminergic system represents a viable target for modulating the effectiveness of L-DOPA therapy in Parkinson's disease.