The rs1076560 polymorphism of DRD2 (encoding dopamine receptor D2) is associated with alternative splicing and cognitive functioning; however, a mechanistic relationship to schizophrenia has not been ...shown. Here, we demonstrate that rs1076560(T) imparts a small but reliable risk for schizophrenia in a sample of 616 affected families and five independent replication samples totaling 4017 affected and 4704 unaffected individuals (odds ratio=1.1; P=0.004). rs1076560(T) was associated with impaired verbal fluency and comprehension in schizophrenia but improved performance among healthy comparison subjects. rs1076560(T) also associated with lower D2 short isoform expression in postmortem brain. rs1076560(T) disrupted a binding site for the splicing factor ZRANB2, diminished binding affinity between DRD2 pre-mRNA and ZRANB2 and abolished the ability of ZRANB2 to modulate short:long isoform-expression ratios of DRD2 minigenes in cell culture. Collectively, this work implicates rs1076560(T) as one possible risk factor for schizophrenia in the Han Chinese population, and suggests molecular mechanisms by which it may exert such influence.
Aims: To study the survival and removal of viruses from fresh fruit and vegetables using the bacteriophage MS2 as a potential surrogate for noroviruses.
Method and Results: Survival of MS2 in ...buffer and on fresh produce was studied at 4, 8 and 22°C. At 4 and 8°C a reduction of <1 log10 was observed after 50 days in buffer; however a reduction in excess of 1 log10 occurred within 9 days at 22°C. Similar results were obtained with fresh produce with virus survival times exceeding the shelf life of the produce. In washing experiments, using a chlorine wash (100 ppm), in all but one case <1·5 log10 MS2 bacteriophage was removed from fruit and vegetables. The mean across all produce types was 0·89 log10. With potable water, reduction was lower (0·3 log mean across all produce types).
Conclusions: MS2 survived for prolonged periods, both in buffer and on fresh produce, at temperatures relevant to chilled foods. It was not removed effectively by chlorine washing.
Significance and Impact of the Study: Bacteriophage MS2 has been evaluated as a potential surrogate for noroviruses on fresh produce. Experimental results together with current knowledge of norovirus resistance and survival indicate that MS2 could be used as an effective surrogate in future evaluations.
The epidermal growth factor receptor (EGFR) family plays an important role in breast carcinogenesis. Much interest has been focused recently on its members because of their potential role as ...prognostic indicators in breast cancer and their involvement in cancer therapy. We have evaluated more than 1500 cases of invasive breast carcinoma immunohistochemically using tissue microarray technology to examine the expression of EGFR family receptor proteins. We have found that 20.1 and 31.8% of cases were positive for EGFR and c-erbB-2, respectively, and 45 and 45.1% of tumours overexpressed for c-erbB-3 and c-erbB-4, respectively. The expression of either EGFR or c-erbB-2 was associated with other bad prognostic features and with poor outcome. Neither c-erbB-3 nor c-erbB-4 had any association with survival. c-erbB-2 had an independent prognostic effect on overall and disease-free survival (DFS) in all cases, as well as in the subset of breast carcinoma patients with nodal metastases. Several hetero- and homodimeric combinations have been reported between the EGFR members. Those dimers can evoke diverse signal transduction pathways with variable cellular responses. We stratified cases according to their co-expression of receptors into distinct groups with different receptor-positive combinations. Patients whose tumours co-expressed c-erbB-2 and c-erbB-3, as well as those whose tumours co-expressed EGFR, c-erbB-2 and c-erbB-4 showed an unfavourable outcome compared with other groups, while combined c-erbB-3 and c-erbB-4 expression was associated with a better outcome. In cases showing expression of one family member only (homodimers), we found a significant association between c-erbB-4 homodimer-expressing tumours and better DFS. In contrast, patients with c-erbB-2 homodimer-expressing tumours had a significant poorer DFS compared with other cases. These data imply that the combined profile expression patterns of the four receptor family members together provide more accurate information on the tumour behaviour than studying the expression of each receptor individually.
Aim: To assess the expression and coexpression of a range of different biomarkers that have been used to define breast carcinomas with a basal phenotype (BP) and their relationship with prognosis in ...an attempt to refine the definition of BP and to evaluate the reliability of using a single biomarker to identify these tumours.
Methods and results: The expression pattern of basal cytokeratins (CK5/6 and CK14), oestrogen, progesterone and androgen receptors, epidermal growth factor receptor, HER2, BRCA1, P‐cadherin and myoepithelial markers (smooth muscle actin and p63) were studied in a well‐characterized series of invasive breast carcinoma (1872 cases) with long‐term follow‐up using immunohistochemistry and tissue microarray. Although the additional markers were associated with basal CK expression, they did not serve to improve recognition of cases with differing outcome when compared with basal CKs alone and, if used to define cases, reduced considerably the proportion of cases allocated to this poor prognostic type of breast cancer.
Conclusion: BP can be defined based on the expression of basal CKs regardless of the expression of other markers.
Precision cut liver slices (PCLSs) retain the structure and cellular composition of the native liver and represent an improved system to study liver fibrosis compared to two‐dimensional mono‐ or ...co‐cultures. The aim of this study was to develop a bioreactor system to increase the healthy life span of PCLSs and model fibrogenesis. PCLSs were generated from normal rat or human liver, or fibrotic rat liver, and cultured in our bioreactor. PCLS function was quantified by albumin enzyme‐linked immunosorbent assay (ELISA). Fibrosis was induced in PCLSs by transforming growth factor beta 1 (TGFβ1) and platelet‐derived growth factor (PDGFββ) stimulation ± therapy. Fibrosis was assessed by gene expression, picrosirius red, and α‐smooth muscle actin staining, hydroxyproline assay, and soluble ELISAs. Bioreactor‐cultured PCLSs are viable, maintaining tissue structure, metabolic activity, and stable albumin secretion for up to 6 days under normoxic culture conditions. Conversely, standard static transwell‐cultured PCLSs rapidly deteriorate, and albumin secretion is significantly impaired by 48 hours. TGFβ1/PDGFββ stimulation of rat or human PCLSs induced fibrogenic gene expression, release of extracellular matrix proteins, activation of hepatic myofibroblasts, and histological fibrosis. Fibrogenesis slowly progresses over 6 days in cultured fibrotic rat PCLSs without exogenous challenge. Activin receptor‐like kinase 5 (Alk5) inhibitor (Alk5i), nintedanib, and obeticholic acid therapy limited fibrogenesis in TGFβ1/PDGFββ‐stimulated PCLSs, and Alk5i blunted progression of fibrosis in fibrotic PCLS. Conclusion: We describe a bioreactor technology that maintains functional PCLS cultures for 6 days. Bioreactor‐cultured PCLSs can be successfully used to model fibrogenesis and demonstrate efficacy of antifibrotic therapies.
Introduction
Following short duration (5‐10s), high intensity (≥70%MVC) muscle activation, there is an enhancement of muscle contractile properties, termed post action potentiation (PAP). During PAP ...induced by voluntary or electrically stimulated conditioning contractions (CC) it has been reported that the corticospinal silent period (SP), assessed by transcranial magnetic stimulation (TMS), is elongated. Although a coexistence between the two occurs, the direct effect of PAP on corticospinal excitability has not been systematically evaluated to help determine whether a direct link exists. The purpose was to assess SP duration following potentiating and non‐potentiating voluntary and electrically stimulated contractions. We hypothesized that maximal and submaximal CCs inducing PAP and those not inducing PAP enhancement, respectively, will prolong SP durations albeit to a lesser degree at submaximal intensities.
Methods
Ten healthy young (three females; 18‐35y) individuals free of neurological issues to date have participated in the study. Subjects were seated with their right forearm pronated and their hand was fixed to a custom finger abduction force dynamometer. Monopolar surface electromyography signals were recorded from the first dorsal interosseous muscle (FDI) with self‐adhering Ag/AgCl electrodes. Peripheral stimulated twitches and tetani (50Hz) were evoked over the ulnar nerve at the wrist via a pair of small readjustable electrodes. Maximal M‐waves (M‐max) and baseline levels of (voluntary and stimulated) PAP and force were obtained for each subject. Electrically stimulated and voluntarily induced CCs of 10s were performed at ~95% MVC and ~35% MVC for a total of four contraction conditions. Before and after these contractions SP times were obtained during the plateau of ~25% MVC held for three seconds. To obtain SP times the TMS output was set to elicit a response ~75% of M‐max. The four conditions of voluntary or stimulated, maximal and submaximal CCs were pseudo‐randomized and repeated four times per subject. The nearest three values from each subject were averaged and compared as a normalized percent change from baseline.
Results
Following both maximal voluntary and stimulated CCs, mean twitch torque was enhanced similarly (PAP ~180%) with no PAP at the submaximal levels. Mean change in SP duration following maximal voluntary CCs was ~14% longer than control values, while maximal tetanic CCs similarly prolonged the SP by ~13%. Both voluntary and stimulated submaximal contractions prolonged SP duration similarly by ~5% and ~6%, respectively.
Conclusion
These findings indicate that corticospinal inhibition assessed as SP elongation is present not only when the muscle is enhanced under PAP but also occurs following contractions inducing no PAP. This suggests that the muscle activation required to induce PAP likely causes the observed corticospinal inhibition, not the enhanced muscle properties of PAP per se.
The transcranial magnetic stimulation-induced silent period reflects a transient state of corticospinal inhibition that is influenced by recent history of muscle activation, which may include an ...effect of potentiation. We demonstrate that silent period duration increases following both voluntary and electrically evoked maximal and submaximal conditioning contractions, even though the latter intensity produced virtually no muscle potentiation. Feedback from group Ia and Ib muscle afferents is proposed as the cause of the increased corticospinal inhibition.
A potentiating conditioning contraction (CC) has been shown to increase silent period duration, an index of corticospinal inhibition; however, it is unknown if the CC must induce potentiation for corticospinal inhibition to increase. Ten healthy, young adults (four females) completed this study to assess potentiation and silent period (SP) duration before and after four types of CCs: voluntary and electrically evoked maximal CCs to optimize potentiation, and voluntary and electrically evoked submaximal CCs (∼40% of maximal voluntary force) that induced minimal potentiation. Stimulation was applied to the ulnar nerve to evoke twitches for the assessment of potentiation and to evoke tetanic CCs of the first dorsal interosseous muscle. The SP was elicited by applying transcranial magnetic stimulation to the motor cortex during brief contractions at 25% of maximal voluntary force. Changes to twitch force and SP duration were not different for voluntary and tetanic contractions, so data were pooled. Twitch force increased by 81.2 ± 35.7% ( P < 0.001) and 3.2 ± 6.5% ( P = 0.039) following maximal and submaximal CCs, respectively. The SP was prolonged following maximal (12.6 ± 6.3%; P < 0.001) and submaximal (4.8 ± 4.9%; P < 0.001) CCs. Correlations between post-CC twitch force and SP duration were not significant for maximal or submaximal conditions ( r = −0.068; r = 0.067; P ≥ 0.780, respectively). Duration of the SP increased not only following maximal-intensity CCs but also after submaximal-intensity CCs that induced virtually no potentiation (∼3%). Thus, we suggest that corticospinal inhibition is not directly related to mechanisms of muscle potentiation per se, but, rather, the level of muscle contraction likely mediates feedback from large diameter afferents that affect the SP.
NEW & NOTEWORTHY The transcranial magnetic stimulation-induced silent period reflects a transient state of corticospinal inhibition that is influenced by recent history of muscle activation, which may include an effect of potentiation. We demonstrate that silent period duration increases following both voluntary and electrically evoked maximal and submaximal conditioning contractions, even though the latter intensity produced virtually no muscle potentiation. Feedback from group Ia and Ib muscle afferents is proposed as the cause of the increased corticospinal inhibition.
PDF
