Stereoselective urinary pharmacokinetics of dl-threo-methylphenidate and its major metabolite in humans.

Stereoselective urinary pharmacokinetics of dl-threo-methylphenidate (MPH) and its major metabolite, dl-ritalinic acid (RA), were examined in a cohort of healthy subjects. On two occasions, separated by one week, each subject received MPH.HCl either intravenously (10 mg) or orally (40 mg). Urine was collected in six time segments, up to 16 h after each dosing. In the first 2 h after oral administration of MPH, d-MPH found in the urine was 10-fold greater than the l-antipode, whereas there was no significant difference between the amounts of MPH enantiomers excreted after the intravenous dose. Examination of RA content in the 0-2-h urine samples after oral administration of MPH indicated the presence of higher levels of l-RA (d-RA:l-RA, 0.37), whereas after intravenous MPH, there was no significant difference between the amounts of RA enantiomers. Moreover, after oral administration of MPH, the ratio of d-MPH to l-MPH was approximately 10 in urine samples from each of the time segments. By contrast, after intravenous administration of MPH, the d:l ratio changed progressively from 1.16 in the 0-2-h urine sample to 9.06 in the 12-16-h sample. These observations suggest that, after oral administration of dl-MPH, the distortion in the ratio of MPH or RA enantiomers in urine samples was attributable to enantioselective presystemic conversion of MPH to RA rather than to enantioselective excretion.     

Analysis of natural and disease-associated autoantibody repertoires: anti-endothelial cell IgG autoantibody activity in the serum of healthy individuals and patients with systemic lupus erythematosus

The present study demonstrates that natural IgG with anti-endothelialcell activity is present in the serum of healthy individualsand in pooled normal human Ig. By using a novel method thatallows for the simultaneous and quantitative assessment of reactivitiesof antibodies with a large number of antigens in tissues, weobserved that natural anti-endothelial cell antibody (AECA)recognizes a restricted set of self antigens in endothelialcells that is conserved among healthy individuals. The extentto which natural AECA activity is expressed in serum and thepattern of reactivity of AECA with endothelial cell antigensshowed little variability between individuals. Analysis of AECAin the serum of patients with systemic lupus erythematosus (SLE)revealed a higher amount of activity and a wider spectrum ofantigentic specificities than that recognized by natural antibodiesin endothelial cell extracts. AECA activity of IgG in wholeserum was lower than that of purified IgG in the case of healthyindividuals and showed little variation among individuals. incontrast, no difference was found between AECA activity of purifiedIgG and that of IgG in patients' serum, suggesting that SLEsera lack the factors that control expression of AECA activityin the serum of healthy individuals. Our results indicate thatnatural autoantibodies recognize a restricted and conservedset of self antigens. Our observations further suggest thatdefective regulation of the expressed autoreactive B cell repertoireis the basis for expansion of novel clonal specificities andenhanced autoantibody activity in serum of patients with autoimmunedisease.     

The presence of chorionic gonadotrophin beta subunit in normal cyclic human endometrium

The aim of the present study was to determine whether human endometrial cells are able to secrete beta-chorionic gonadotrophin (betaCG). Immunohistochemical studies and in-situ hybridization were performed in order to provide evidence for the occurrence of betaCG in the normal endometrium in 15 patients in the proliferative phase, two patients in the periovulatory phase and 13 patients in the secretory phase. Neither immunohistochemical nor hybridization reactions could be recognized during the proliferative phase. In contrast, both protein and betaCG mRNA were observed in the glandular cells of the endometrium during the secretory phase. The results were supported by Western blotting of secretory phase endometrium extracts and the assessment of the functional secretory capacity of primary endometrium cultures. In comparison with cultured and separated cell fractions, tissue extracts showed a higher betaCG, indicating a regulatory interaction. In conclusion, betaCG can be demonstrated in normal human cyclic endometrium, suggesting a paracrine role in endometrial physiology.      

Traction bronchiectasis in end-stage pulmonary fibrosis

Postmortem examination of the lungs of 12 patients with end-stage pulmonary fibrosis revealed the frequent (nine of 12) presence of bronchiectasis. The segmental and subsegmental bronchi were dilated, tortuous, and had a convoluted appearance that resembled a string of pearls. Bronchiectasis was confined to areas of advanced fibrosis. When fibrosis was mild or when it was combined with emphysema, bronchiectasis was absent or mild. Specimen radiographs revealed that bronchiectasis frequently contributed to the radiographic appearance of honeycombing. Retrospective analysis of the plain chest radiographs obtained from five of the patients revealed evidence suggestive of bronchiectasis, but bronchiectasis was difficult to detect unless the surrounding lung was radiopaque. In two living patients with end-stage pulmonary fibrosis, bronchiectasis was much better depicted on computed tomography scans than on plain chest radiographs. In patients with pulmonary fibrosis, the presence of bronchiectasis does not necessarily imply the presence of primary bronchial disease. Rather, bronchiectasis can be a direct result of the fibrotic process.     

Early biochemical and histological changes in rats exposed to a single injection of thioacetamide

Liver injury was induced by one subcutaneous administration of thioacetamide (200 mg/kg b.wt.) and studied 24 and 48 hrs later. Levels of aspartate aminotransferase (ASAT) and alanine aminotransferase (ALAT) increased after 24 and 48 hrs. The lysosomal enzymes beta-hexosaminidase (beta-NAG) and beta-glucuronidase (beta-GLU) increased significantly after 24 hrs, while the level of beta-GLU returned to normal after 48 hrs, but the activity of beta-NAG remained significantly high even after 48 hrs. Histopathological examination showed necrotic hepatocytes around the central vein with infiltration of macrophages, neutrophils and eosinophils. The plasma zinc level decreased after 24 hrs and returned to normal after 48 hrs. Liver zinc content increased simultaneously at 24 hrs, returning to normal after 48 hrs. No alterations of plasma copper were observed after 24 and 48 hrs. Copper content of the liver increased significantly after 24 and 48 hrs. The present study thus shows that one dose of thioacetamide results in profound liver injury and supplementation of zinc prior to and simultaneously with thioacetamide normalized plasma zinc, increased liver zinc content and reduced the increase of beta-NAG, but did not influence the histological changes.     

Expandable intraluminal graft: a preliminary study. Work in progress

To overcome the problem of recurrence of stenosis after vascular balloon dilatations, we developed an expandable, intraluminal graft that allows dilatation of the lesion and simultaneous placement of a supportive endoprosthesis to prevent recoil of the arterial wall. The graft is made of continuous, woven, stainless steel wire. The resulting tubular mesh has a wall thickness of 200-450 micron and 80% open surface. The grafts, mounted on angioplasty catheters, are introduced through 8-12-F Teflon sheaths. Eleven grafts of 6, 8, and 10 mm in diameter by 20 mm long were placed in the aorta, common carotid, superior mesenteric, iliac, and renal arteries of dogs. Six grafts showed no stenosis in follow-up studies of up to 8 weeks. Two grafts had moderate stenosis as a result of neointimal hyperplasia. Two partial and one complete graft thrombosis occurred in nonheparinized animals in which the graft outflow was restricted. Anticoagulant was not used on a long-term basis. Light and electron microscopy studies showed complete covering of the graft's inner surface by endothelium at 3 weeks.     

米非司酮终止早孕绒毛组织中一氧化氮合成酶活性及血清雌二醇、孕酮的测定

米非司酮终止早孕绒毛组织中一氧化氮合成酶活性及血清雌二醇、孕酮的测定杨晓葵李明冯淑芝杨菁管楚玉近年来的研究发现，一氧化氮（Ｎｉ－ｔｒｉｃｏｘｉｄｅ，ＮＯ）是一种具有多种生物学潜能的局部调节因子，参与调节胚胎的发育和生殖激素的合成与释放。为了探讨米非司...     

Sacrococcygeal chordoma metastatic to penis

A rare case of sacrococcygeal chordoma metastatic to the penis is presented The symptoms, diagnosis, and management of sacrococcygeal chordoma are discussed.     

HIV topic update: protease inhibitor therapy and oral health care

Protease inhibitors have been a major advance in the management of HIV disease and have reduced the frequency and severity of many complications, including some oral lesions. They may also be of value in the management of occupational exposures to the virus. However, they may produce adverse effects including oral symptoms such as paraesthesia, taste disturbances and xerostomia, and may interact with a number of drugs used in oral health care. This article summarises the current situation.