妊娠期妇女的人体测量及脂肪贮存

本文对30名居住北京城近郊区的健康初产孕妇,于妊娠早期、中期及末期连续进行人体测量,包括身长,体重,皮下脂肪厚度和肢体围,以观察孕期体重增长,身体脂肪含量及肌肉情况。测量结果,受试者从妊娠6周至37周平均体重增长13.0kg。三头肌、二头肌部位皮脂厚度在孕期无明显变化。肩胛下皮脂厚度至孕末期时明显较早期增加。髂骨上皮脂厚度在孕中期及末期均有明显增长,与早期相比差別显著。据皮脂厚度计算身体密度及脂肪含量络果,至孕末期身体脂肪含量占体重的百分比共增加3.7％。肢体围测量结果,仅臀围在妊娠中期后至末期明显较早期增大。大腿上部围略有增加,但与早期差别无显著意义。大腿中部、小腿腓肠肌部及上臂围孕期均无明显变化。     

高频超声检测颈动脉内膜-中层厚度及外周血管内皮功能评价动脉粥样硬化

目的 探讨高频超声检测颈动脉内膜-中层厚度与肱动脉内皮依赖性舒张功能在动脉粥样硬化中的诊断价值.方法 冠状动脉造影的老年患者69例及青年志愿者20例,分别行颈动脉超声检查,同时采用充气加压法测定肱动脉血流介导的内径扩张值,超声测值与冠脉造影结果对照分析.结果 ①颈动脉内膜-中层厚度值随粥样硬化斑块的增多、冠脉狭窄程度的加重而增高;②动脉粥样硬化患者在内膜-中层厚度值增高之前即可出现内皮功能损伤,肱动脉内径扩张值降低早于内膜-中层厚度值增高之前出现,内径扩张值随冠脉狭窄程度加重而下降.结论 高频超声检测颈动脉内膜-中层厚度、内径扩张值诊断早期动脉粥样硬化敏感性高,并且有助于对冠脉狭窄程度作出判断.     

Thickness effects of a carbon-supported platinum catalyst layer on the electrochemical reduction of oxygen in sulfuric acid solution

The influence of the thickness of a carbon-supported platinum catalyst layer on the oxygen reduction reaction (orr) has been studied in sulfuric acid solution by means of a thin-film rotating disk electrode. Pronounced changes in the Pt utilization, electrode activity and the orr kinetics have been observed upon varying the catalyst layer thickness. The thicker film electrode exhibits a higher Pt utilization efficiency and higher activity, and promotes the orr kinetics at potentials relevant to fuel cell operations. The participation of Pt surfaces not in contact with the electrolyte solution in electrochemical reactions via the spillover of adsorbed hydrogen and oxygen species, is proposed to be responsible for the changes. The thicker catalyst layer is likely to modify the Pt particle–particle distance by providing shared Pt sites between adjacent carbon supports, to improve the surface density of active catalyst particles per single carbon support by sharing adjacent catalyst sites, and to increase the ratio of the particle surfaces free of blocking anions to the catalyst|electrolyte interface surfaces. The carbon-supported platinum catalyst layer becomes active at 0.90 V vs RHE only when the catalyst layer is thicker than 1 μm. To provide reasonable activity, the minimum catalyst layer thickness should be around 2–4 μm. These results should be considered in the design of the cathode catalyst layer of polymer electrolyte membrane fuel cells.     

颈动脉粥样硬化斑块中COX-2、mPGES-1表达及塞来昔布对其的影响作用

目的探讨兔颈动脉粥样硬化斑块中环氧化物酶-2（COX-2）、诱导型前列腺素合成酶-1（mPGES-1）的表达机制及塞来昔布对其表达的影响。方法采用32只雄性新西兰大白兔．其中正常对照组8只（A组），另24只将特制的硅橡胶圈置于兔右侧颈动脉。术后给予1％高胆固醇喂养14d，建立兔颈动脉粥样硬化性狭窄动物模型，将模型兔随机分为颈动脉狭窄无干预组（B组1、小剂量塞来昔布治疗组（15mg／kg，C组），大剂量塞来昔布治疗组（35mg／kg，D组），每组各8只。治疗4周后取双侧颈动脉并分为平等2段，分别行半定量逆转录聚合酶链反应（RT—PCR）及Western blot法测定颈动脉斑块干预后COX-2及mPGES-1的表达。结果与A组比较,B、C、D组颈动脉粥样硬化模型兔的斑块中COX-2及mPGES．1表达增高，差异具有显著性（P〈0．05）；与B组比较，C、D组颈动脉斑块的C0X-2及mPGES．1表达显著下调，差异有显著性（P〈0．051。结论在颈动脉粥样硬化斑块的病理过程中炎症反应可能起着主导作用。塞来昔布干预可抑制COX-2及mPGES—1的表达，减缓颈动脉粥样硬化的进展。     

Carotid intima-media thickness in Parkinson's disease.

There have been a few studies and inconsistent results regarding the coincidence of Parkinson's disease (PD) and atherosclerotic diseases, such as cerebrovascular disease. Carotid intima-media thickness (IMT) is a known marker for subclinical atherosclerosis. The aim of this study was to investigate the carotid IMT between PD patients and controls. We studied 43 patients with PD and 86 matched controls. The carotid IMT in PD patients was significantly smaller than in controls (0.796 +/- 0.179 mm vs. 0.913 +/- 0.237 mm, P < 0.05). In multivariate analysis, the carotid IMT was inversely associated with the duration of levodopa medication and the severity of PD. These results suggest that PD patients have a lower risk of atherosclerosis.     

脑保护下的颈动脉狭窄内支架治疗

目的 评价经皮血管内支架成形术联合应用颈动脉滤器对颈动脉狭窄的治疗效果。方法12例有临床症状的颅外颈动脉狭窄患者接受血管内支架植入治疗，术中同时使用颈动脉滤器进行脑保护，并对颈动脉滤器所回收的物质进行病理学分析。结果12例患者支架及滤器均成功植入，滤器均成功回收。回收物质为微小血栓颗粒、泡沫细胞、胆固醇颗粒。结论经皮血管内支架成形术联合应用颈动脉滤器，可有效缓解颈动脉狭窄所致的血流障碍，预防术中脱落的微小栓子进入脑内。     

Female patients complaining about hair loss: documentation of defective scalp hair dynamics with contrast-enhanced phototrichogram

BACKGROUND: The complaint of chronic hair loss frequently affects female subjects and there is little or no objective technology available in the general dermatology or even in the hair clinics to guide the observer in the management of the patient. The purpose of this report is to share the results of refined hair growth measurements that were collected in 92 female subjects complaining about hair loss. METHODS: Clinically they were classified as having a patterned hair loss according to Ludwig (L; n=50), diffuse hair loss (D; n=13) or no visible hair loss but complaining of hair shedding (N; n=29). Two scalp sites on the top of the head and one occipital site were investigated after clipping by close-up photography before and after a hair dye (contrast enhancement, CE). Forty-eight hours later a new photograph was taken after CE in view of phototrichogram analysis (CE-PTG). Finally a last hair clip was performed 30 days later and hair thickness and length determined for linear growth measurements (LHGR). RESULTS: Herein we confirm that the top of the head shows usually a higher hair density than occipital sites, a physiological observation that applies both to men and women. From the technological perspective, we also document that CE improves hair detection in all sites. Interestingly, in affected patients (L and D) the relative increase of hair counts after CE was much higher (range +22.4% to +28.3%) compared with apparently unaffected females (N; range +8.2% to +9.7%). This increase in hair counts was only due in part to the presence of less pigmented thinning hair (thickness less than 40 microm). Such thin hairs were found in statistically significantly higher proportions in younger patients with mildly severe (grade I) patterned alopecia (Ludwig: L). In other patients with hair loss and in more severe forms of patterned alopecia - especially in older patients - the thin hair is not detected in abnormal proportions. In all sites slower growth rates and decreased anagen percentages indicate a defective hair replacement programme distinguishing L patterns from diffuse hair loss and from apparently unaffected patients complaining of chronic hair loss. Globally, we also noted that increasing age is associated with significant regression of scalp hair (decreased hair counts, thinner hair and slower LHGR). CONCLUSION: On the basis of the present data together with female data from the literature and our own studies in male subjects, we suggest a three-step mechanism leading to hair loss 1.Shortening of growth phase the hair cycle with maintained thick hair, i.e. more frequent hair cycling that leads to more hair shedding. 2.Intermittent production of short thin hair, i.e. morphological evidence of miniaturisation. 3.Very occasional or almost no hair production, i.e. dormant follicles or irreversible follicular atrophy. Depending on the genetic background, hormonal microenvironment in the scalp and conditioning of individual hair follicle bio-responses, female and male patterned hair loss may end up into different phenotypes.     

颈动脉粥样硬化斑块内MCP-1表达的研究

目的观察颈动脉粥样硬化(AS)斑块内单核细胞趋化蛋白-1(MCP-1)的mRNA和抗原的表达情况。方法分别应用原位杂交和免疫组织化学法测定颈AS斑块中MCP-1mRNA和抗原表达。结果相对于正常动脉内膜,颈AS病变内膜MCP-1阳性细胞数明显增多(P<0.05)。其中颈AS严重病变肩区阳性细胞数最多,以单核-巨噬细胞为主。结论MCP-1与颈AS发生密切相关。