冷冻食品中损伤大肠菌群的修复探讨

目的：为了准确测定冷冻食品中大肠菌群含量。避免对冷冻损伤大肠菌群的漏检。方法：应用营养物质丰富的营养肉汤，对冷冻损伤的大肠菌群在接触选择性培养基前在37℃孵育2h。结果：营养肉汤在37℃孵育冷冻损伤大肠菌群2h后，选择性平皿上菌落数与非选择性平皿上菌落数相当，细菌未发生显著繁殖；在实际样品应用试验中，提高了大肠菌群阳性样品的检出率。结论：应用营养肉汤37℃孵育冷冻损伤大肠菌群2h，可使其得到良好的修复，此修复过程是对常规检测大肠菌群方法的改进和完善。     

人血浆高密度脂蛋白对大鼠内毒素血症的治疗及防护作用研究

目的:观察人血浆高密度脂蛋白(HDL)对大鼠内毒素血症的治疗和防护效果。方法:采用鲎试剂法和放射免疫分析法于3个时点动态测定对照组、治疗组和防护组大鼠血浆内毒素(ET)水平和肿瘤坏死因子(TNF)浓度并观察血压及存活时间。结果:①输注ET后对照组大鼠血压进行性下降(P<0.01);治疗组大鼠输注HDL后其血压虽也降低但下降程度明显弱于对照组(P<0.01);防护组大鼠在输注ET后血压无明显下降(P>0.05)。治疗组及防护组大鼠存活时间均明显长于对照组(P<0.01)。②3组大鼠血浆ET水平在各时点均无明显变化(P>0.05)。③治疗组及防护组大鼠血浆TNFα水平于第3时点均明显降低(P>0.05)。结论:人血浆HDL能减轻或抑制内毒素血症大鼠血压下降并明显延长其存活时间,对内毒素血症具有良好的治疗和防护作用,此作用可能与其抑制TNF释放有关。     

肾移植受者T淋巴细胞核仁区酸性非组蛋白表达活性研究

目的探讨T淋巴细胞核仁区酸性非组蛋白表达活性(Ag-NORs)对肾移植受者术前及术后用药病情监测的应用价值.方法应用普通细胞银染技术对32例肾移植患者术前及术后使用免疫抑制剂1,2,3周外周血T淋巴细胞染色,通过计算机显微图像分析技术,计算硝酸银染色酸性非组蛋白(Ag-NORs)面积与核面积的比值(I*S%).结果肾移植患者术前Ag-NORs的I*S%为(6.31±0.86);术后使用免疫抑制剂1,2,3周Ag-NORs的I*S%分别为(4.72±0.93),(4.28±1.05),(4.66±1.21).肾移植术后各期与术前Ag-NORs的I*S%差异有显著性意义(P＜0.01);术后各期之间Ag-NORs的I*S%差异无显著性意义(P＞0.05).结论T淋巴细胞核仁酸性非组蛋白表达活性在肾移植及其术后用药病情监测中具有重要的意义.     

Distinct hippocampal subfield atrophy in Parkinson's disease regarding motor subtypes

IntroductionGlobal hippocampal atrophy has been repeatedly reported in patients with Parkinson's disease (PD). However, there is limited literature on the differential involvement of hippocampal subfields among PD motor subtypes. This study aimed to investigate hippocampal subfield alterations in patients with PD based on their predominant symptoms.MethodWe enrolled 31 PD patients with the tremor-dominant (TD) subtype, 27 PD patients with postural instability and gait disturbance-dominant (PIGD) subtype, and 40 healthy controls (HCs). All participants underwent high-spatial-resolution T1-weighted magnetic resonance imaging. The volume of hippocampal subfields was measured using FreeSurfer software, compared across groups, and correlated with clinical features.ResultsWe found volumetric reductions in the hippocampal subfield in both patient subtypes compared to HCs, which were more pronounced in the PIGD subtype. The PIGD subtype had accelerated age-related alterations in the hippocampus compared to the TD subtype. Bilateral hippocampal volumes were positively associated with cognitive performance levels, but not with disease severity and duration in patients.ConclusionsAlterations in the hippocampal subfields of patients with PD differed based on their predominant symptoms. These findings are of relevance for understanding the pathophysiology of the increased risk of cognitive impairment in PIGD.     

Alteration of functional connectivity within visuospatial working memory-related brain network in patients with right temporal lobe epilepsy: A resting-state fMRI study

PurposeThis study aimed to investigate the resting-state brain network related to visuospatial working memory (VSWM) in patients with right temporal lobe epilepsy (rTLE). The functional mechanism underlying the cognitive impairment in VSWM was also determined.MethodFifteen patients with rTLE and 16 healthy controls matched for age, gender, and handedness underwent a 6-min resting-state functional MRI session and a neuropsychological test using VSWM_Nback. The VSWM-related brain network at rest was extracted using multiple independent component analysis; the spatial distribution and the functional connectivity (FC) parameters of the cerebral network were compared between groups. Behavioral data were subsequently correlated with the mean Z-value in voxels showing significant FC difference during intergroup comparison.ResultsThe distribution of the VSWM-related resting-state network (RSN) in the group with rTLE was virtually consistent with that in the healthy controls. The distribution involved the dorsolateral prefrontal lobe and parietal lobe in the right hemisphere and the partial inferior parietal lobe and posterior lobe of the cerebellum in the left hemisphere (p < 0.05, AlphaSim corrected). Between-group differences suggest that the group with rTLE had a decreased FC within the right superior frontal lobe (BA8), right middle frontal lobe, and right ventromedial prefrontal lobe compared with the controls (p < 0.05, AlphaSim corrected). The regions of increased FC in rTLE were localized within the right superior frontal lobe (BA11), right superior parietal lobe, and left posterior lobe of the cerebellum (p < 0.05, AlphaSim corrected). Moreover, patients with rTLE performed worse than controls in the VSWM_Nback test, and there were negative correlations between ACCmeanRT (2-back) and the mean Z-value in the voxels showing decreased or increased FC in rTLE (p < 0.05).ConclusionThe results suggest that the alteration of the VSWM-related RSN might underpin the VSWM impairment in patients with rTLE and possibly implies a functional compensation by enlarging the FC within the ipsilateral cerebral network.     

Identification of odorant‐binding and chemosensory protein genes and the ligand affinity of two of the encoded proteins suggest a complex olfactory perception system in Periplaneta americana

The American cockroach (Periplaneta americana) is an urban pest with a precise chemosensory system that helps it achieve complex physiological behaviours, including locating food and mating. However, its chemosensory mechanisms have not been well studied. Here, we identified 71 putative odorant carrier protein genes in P. americana, including 57 new odorant‐binding proteins (OBPs) and 11 chemosensory proteins (CSPs). To identify their physiological functions, we investigated their tissue expression patterns in antennae, mouthparts, legs, and the remainder of the body of both sexes, and determined that most of these genes were expressed in chemosensory organs. A phylogenetic tree showed that the putative pheromone‐binding proteins of P. americana were in different clades from those of moths. Two genes, PameOBP24 and PameCSP7, were expressed equally in antennae of both sexes and highly expressed amongst the OBPs and CSPs. These genes were expressed in Escherichia coli and the resultant proteins were purified. The binding affinities of 74 common odorant compounds were tested with recombinant PameOBP24 and PameCSP7. Both proteins bound a variety of ligands. Our findings provide a foundation for future research into the chemosensory mechanisms of P. americana and help in identifying potential target genes for managing this pest.