An ultrastructural study of cartilage resorption at the site of initial endochondral bone formation in the fetal mouse mandibular condyle

An ultrastructural study was undertaken on cartilage resorption at the site of initial endochondral bone formation in the mouse mandibular condyle on d 16 of pregnancy. After resorbing the bone collar, the osteoclasts extended their cell processes into the cartilage matrix and made contact with hypertrophic chondrocytes. By means of cell processes or vacuolar structures, these osteoclasts entrapped the calcified cartilage matrices, cell debris, and the degraded uncalcified cartilage matrices. In particular, since the calcified cartilage matrices were sometimes seen to be disrupted within the osteoclastic vacuolar structures, they were probably disposed of by the osteoclasts. Invading endothelial cells giving rise to capillaries also directly surrounded the degraded uncalcified cartilage matrices and small deposits of cell debris. In addition, hypertrophic chondrocytes that had attached to or were in the process of attaching to the invading osteoclasts often enclosed the small calcified cartilage matrices. Other cell types that have often been reported in other regions of cartilage resorption were not seen at the site of initial endochondral bone formation in this study. Our findings in relation to cartilage resorption may therefore represent unique features of the site of initial endochondral bone formation site. We consider that the manner of cartilage resorption is likely to vary by site, age, and species.     

冬虫夏草对小鼠红系造血机能的影响

用微量甲基纤维素培养方法探讨冬虫夏草结晶制剂(CS-Cr)对小鼠骨髓红系祖细胞(CFU-E和BFU-E)增殖的影响。实验结果表明,CS-Cr明显提高骨髓CFU-E和BFU-E产率、自杀率,并能对抗三尖杉酯碱对造血机能的损害。采用液体培养技术发现CS-Cr促进骨髓成纤维祖细胞(CFU-F)增殖,其产率变化与CFU-E和BFU-E产率变化一致。     

An atypical case of mononeuritis multiplex in primary Sjogren's syndrome

We present an atypical case of peripheral nervous system (PNS) involvement in Sjogren's syndrome in a 63 year-old woman. Symptoms of an entrapment neuropathy were the first manifestation of the systemic disease and they were subsequently coupled to those of a mononeuritis multiplex. Clinical and laboratory signs for the diagnosis of Sjogren's syndrome became subsequently overt. The mononeuritis multiplex remained clinically limited to the upper limbs and characterized by unusually severe motor symptoms which progressed up to the development of a final complete deplegia. By contrast, sensory symptoms at the upper limbs remained mild over the entire course of the disease and the lower limbs revealed a subclinical sensory-motor damage only during the late stage.     

Natural killer cell activity and serum immunoglobulins in epileptic patients

Serum immunoglobulins and the activity of natural killer (NK) cells of 50 epileptic patients (eight with idiopathic generalized epilepsy and 42 with cryptogenic partial epilepsy) and 28 controls have been studied. The values of IgA, IgG and IgM were the same-in patients and controls. The NK activity in controls was linearly related to the effector-to-target ratio, but this linear relationship was not observed in epileptic patients. The cytotoxic activity of NK cells at the lowest effector-to-target ratio was significantly greater in patients than in controls. This increase was observed in each therapy group. Our results seem to confirm a disturbance of the immune system in epileptic patients and suggest that this modification of cellular immunity is not a drug effect but is related to the illness itself.     

Laser Doppler flowmetry of blood perfusion in mucoperiosteal flaps covering membranes in bone augmentation and implant procedures. A pilot study in dogs.

In guided tissue regeneration (GTR) procedures, flap recession or sloughing may occur as an unwanted sequel to the placement of a membrane. This study was designed to assess the applicability of laser Doppler flowmetry (LDF) in the evaluation of blood perfusion in the mucoperiosteal flap covering the membrane. Five Labrador dogs were initially used inthe study, but one animal was later excluded due to post‐operative problems. Maxillary premolar teeth were extracted and full thickness mucoperiosteal flaps were raised. Following removal of the buccal bone plate, 4 titanium implants were placed on each side. An experimental biodegradable polylactic‐acid membrane was placed over the fixtures on one side to allow for GTR. The mucoperiosteal flap was repositioned and secured with sutures. The contralateral side served as control with no membrane. Blood perfusion was measured in the flaps before surgery, immediately after suturing and at 24, 48 and 72 h postoperatively. A laser Doppler flowmeter was used to assess the blood perfusion. In 3 animals the membrane was exposed within 2 weeks post‐operatively, and in these 3 animals the LDF values were lower on the membrane side than on the control side. The mean LDF value was lower on the membrane side for each of the 4 periods studied. The tindings suggest that LDF can be a valuable method to study blood perfusion of oral mucosal flaps and that there may be a relationship between a reduced relative LDF value and subsequent exposure of the membrane to the oral environment.     

烧伤后红细胞损伤的机制——过氧化脂质、维生素E与溶血的关系

本实验发现大鼠体表面积20％Ⅲ°烧伤后,皮肤内产生了大量丙二醛(MDA),第二天达最高,第七天有第二高峰,血浆和红细胞(RBC)MDA第三天达最高,血浆和RBC维生素E(VE)于伤后第二天后迅速下降,RBC溶血第三天最甚。对皮肤MDA、血浆MDA、RBCMDA、血浆VE、BBC VE、1％H_2O_2溶血进行相关分析后发现在不同时相,有不同的相关关系,但基本遵循烧伤皮肤MDA增加、血浆MDA增加、RBC MDA增加、血浆和RBC VE降低,溶血增加的规律。文中讨论了RBC损伤的机制。     

The effect of pH and nucleophiles on complement activation by human proximal tubular epithelial cells.

BACKGROUND: Activation of urinary complement proteins in situ by proximal tubular epithelial cells (PTEC) may contribute to the mediation of tubulointerstitial injury in patients with significant proteinuria. However, the mechanism involved is unclear, and the role of changes in urinary pH and in the concentrations of urea or ammonia requires further clarification. METHODS: The protein fraction of urine samples from nine patients with proteinuria >1.5 g/day was purified. A cell ELISA involving cultured HK-2 PTEC was used to investigate the capacity of urinary protein to promote the deposition of both C3 and C9 on the cell surface. The effect of variations in pH (5.5-8.0) and in the concentration of urea and ammonia was also examined. C3 was purified and used to further investigate the mechanism of complement deposition. RESULTS: Urine samples from the majority of patients induced deposition of C3 and C9 on the surface of HK-2 cells via the alternative pathway. This process was maximal at acidic pH values. Preincubation of urinary complement or serum with urea or ammonia inhibited C3 deposition. Purified C3 incubated with HK-2 cells showed no evidence of activation in the absence of other complement components. CONCLUSIONS: These data suggest that bicarbonate protects against complement-mediated damage in the lumen by increasing the local pH, rather than by inhibiting the generation of ammonia. PTEC appear to activate complement through provision of a 'protected site' on their surface, rather than by the activation of C3 by convertase-like protease(s).     

The Effect of Acute and Chronic Exercise on Thyroid Hormones in Obesity

Abstract Thyroid hormones were measured before, during and after acute exercise (60 min) or physical training (3 months) in obese women. Thyroid stimulating hormone concentration increased during acute work and decreased immediately after. No changes were seen during the two following days. An increase was seen after ten days as well as after three months of physical training. Thyroxine concentrations showed no changes. 3,5,3′-Triiodothyronine decreased slightly immediately after acute exercise, and after three months of physical training, 3,3′,5′-triiodothyronine (reverse triiodothyronine) increased slowly during and after acute exercise. A negative correlation was found between changes in fasting insulin and thyroxine and a positive correlation between changes in blood pressure and triiodothyronine after training. Lack of agreement in previous reports is probably due to methodological differences such as methods more or less susceptible to fatty acid interference, and thyroid hormones changing differently during acute work and before and after physical training. The duration of the study may also be of importance, even 3 months possibly being too short for attaining equilibrium in thyroid homeostasis.     

社区高血压分级管理方式及干预效果的探讨

目的　实施社区高血压分级管理 ,探讨社区干预措施对心脑血管病预防控制的效果。方法　随机抽取潍坊社区部分居委为干预组 ,对其中 2 2 31名高血压患者从 1998～ 2 0 0 0年进行分级管理 ,又随机抽取部分居委为对照组 ,比较两组脑卒中发病率、死亡率。结果　高血压患者的管理率达 89 5 3% ,控制率达 78 73% ;干预组脑卒中发病率为 198 73/ 10万 ,死亡率 77 2 8/ 10万 ;对照组脑卒中发病率为 2 2 2 2 3/ 10万 ,死亡率 80 81/ 10万。两组标化后脑卒中发病率、死亡率间差别均有显著性意义 (P <0 0 5 )。结论　干预组脑卒中的标准化发病率及死亡率均低于对照组 ,说明高血压分级管理的社区干预措施对心脑血管病的预防控制是有效的