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81.
Rheumatoid arthritis (RA) is the most frequent inflammatory joint disease, and it affects about 1% of the population. The onset of arthritis is rarely acute; it is subacute and usually progresses slowly. The clinical picture of RA is variable: mild to very aggressive and destructive courses, sometimes accompanied by organ involvement, leading to severe functional impairment and early disability can be observed. RA is diagnosed according to the ACR criteria published in 1958 and modified in 1988. The appearance of a palpable joint swelling or effusion is obligatory for the clinical diagnosis of arthritis. In RA, typically involvement of the joint of the hands and feet can be seen. Laboratory parameters play an important role as both diagnostic and prognostic tools. Besides clinical features and laboratory parameters, imaging techniques provide another cornerstone in the diagnosis of RA. Until now plain X-rays, which primarily visualize osseous changes, are the most important technique in daily practice, whereas magnetic resonance imaging and ultrasound may provide information about soft tissue changes in an earlier stage of disease. The main differential diagnoses of RA to be considered are the seronegative spondylarthropathies (psoriatic arthritis, arthritides accompanying inflammatory bowel diseases, Reiter's syndrome, and spondylitis ankylosans with peripheral arthritis), Parvovirus-induced arthritis, crystal-induced arthritides and septic arthritis. Early diagnosis and therapeutic intervention seem to be of great prognostic importance. In several independently performed investigations a higher mortality was found in RA patients than in the normal population. Drug therapy of RA consists of nonsteroidal antirheumatic drugs (NSAIDs), corticosteroids and disease-modifying drugs (DMARDs). When the functional and radiological parameters were assessed, the DMARDs were found to have a disease modifying and in rare cases a remission-inducing property. Moreover, tolerance these to drugs is limited. Newer therapeutic trials have employed substances like Tenidap, Leflunomid, bacterial extracts, antibiotics and biological subcomes (e.g., monoclonal antibodies against cytokines, fusion proteins for soluble cytokinereceptors). Some promising results of these investigations need confirmation in larger patient populations, but some new perspectives for a more efficacious treatment of RA can be expected.  相似文献   
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Recurrent infection with hepatitis C virus (HCV) is almost universal following orthotopic liver transplantation although clinical severity varies. Data on 135 patients who underwent transplantation for hepatitis C cirrhosis were reviewed. We describe a progressive, severe cholestatic form of hepatitis occurring in a subgroup of patients with recurrent hepatitis C. Ten patients with severe recurrent hepatitis C were identified; 1 has died, 1 awaits retransplantation, and 8 have undergone retransplantation. All 10 developed severe progressive cholestatic hepatitis, with a mean rise in bilirubin to 24.7 mg/dL at the time of retransplantation. Histology at initial recurrence was of mild hepatitis without evidence of rejection. The failed grafts showed either cirrhosis or confluent hepatic necrosis. The onset of cholestasis preceded retransplantation by less than 5 months. Our study suggests that a minority of patients with recurrent hepatitis C after undergoing liver transplantation develop a severe progressive cholestatic hepatitis and liver failure.  相似文献   
84.
Prompt restoration of coronary artery patency in acute myocardial infarction is associated with substantial improvements in morbidity and mortality. The pivotal role of thrombolysis and aspirin in achieving these goals is well established. However, despite the success of thrombolytic therapy in large trials, clinical assessment in individual patients often suggests that reperfusion has not occurred after initial therapy. This review considers the validity of such bedside predictions and discusses whether such patients should be managed differently.  相似文献   
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PURPOSE: We report the long-term results of penile revascularization surgery for erectile failure and suggest possible selection criteria for this controversial surgical procedure. MATERIALS AND METHODS: In 7 years 62 impotent men who did not respond to pharmacotherapy underwent microsurgical penile revascularization and completed long-term followup evaluation in 41 months (range 18 to greater than 62) consisting of a detailed questionnaire, duplex sonography and optional pharmacotherapy or angiography. The Virag procedure was chosen for the first 7 patients, the original Hauri technique for the next 13 and the modified Mannheim triple anastomosis for 42. RESULTS: Of all patients 34% achieved spontaneous and another 20% pharmacologically induced erections. Success in diabetics and older patients was lower (43% for diabetics, 39% for those older than 50 years at surgery), while it was high in men with less than 2 risk factors (58%) as well as in younger patients (69% for those up to 50 years old). Shunt patency was 92%. Complications such as glans hyperemia developed in 13% of patients, shunt thrombosis in 8% and inguinal hernias in 6.5%. CONCLUSIONS: Patient selection is vital for the successful outcome of penile revascularization surgery. We adhere to strict selection criteria, such as patient age maximum of 50 years, less than 2 risk factors, no recent diabetes and termination of nicotine abuse. Penile revascularization surgery is highly indicated in this group of patients, especially since it is the only causal therapy for erectile failure.  相似文献   
87.
This study was designed to define more precisely the relationship between specific angiotensin receptors and the growth of vascular smooth muscle cells in response to angiotensin II. These experiments employed quiescent A10 cells which were characterized as smooth muscle by the expression of specific contractlle proteins. Cell growth was monitored by measuring the incorporation of metabolic precursors into RNA or DNA. The treatment of A10 cells with angiotensin II (1 microM) stimulated a hypertrophic response as indicated by an increase in RNA synthesis and protooncogene expression in the absence of DNA synthesis. This increase in RNA synthesis could be blocked by PD123319, an AT2 antagonist, but not by losartan, an AT1 antagonist. RT-PCR analysis demonstrated that quiescent A10 cells express only the AT2 receptor while proliferating A10 cells express the AT1a and AT1b receptors in addition to the AT2 receptor. In addition, induction of AT2 receptor-mediated RNA synthesis was prevented by indomethacin, a cyclooxygenase inhibitor. These studies therefore support a direct connection between the AT2 receptor and smooth muscle growth that is mediated, in part, by prostaglandin synthesis.  相似文献   
88.
In vitro selection experiments have produced nucleic acid ligands (aptamers) that bind tightly and specifically to a great variety of target biomolecules. The utility of aptamers is often limited by their vulnerability to nucleases present in biological materials. One way to circumvent this problem is to select an aptamer that binds the enantiomer of the target, then synthesize the enantiomer of the aptamer as a nuclease-insensitive ligand of the normal target. We have so identified a mirror-image single-stranded DNA that binds the peptide hormone vasopressin and have demonstrated its stability to nucleases and its bioactivity as a vasopressin antagonist in cell culture.  相似文献   
89.
AIM: The reliability of Doppler echocardiography in determining the mitral valve area after balloon mitral valvuloplasty has been questioned, as discrepancies were noted between measurements obtained by the pressure half-time method and those derived haemodynamically, immediately following completion of the procedure. Recent investigations, however, have indicated that these discrepancies may be attributable to the over-estimation of the mitral valve area by haemodynamic measurements, caused by the presence of the iatrogenic atrial septal defect complicating transseptal catheterization. The aim of the present study was to further test this hypothesis. METHODS AND RESULTS: Measurements of the mitral valve area by the Doppler pressure half-time method and the Gorlin formula were obtained and compared in 238 consecutive patients before and immediately after retrograde non-transseptal balloon mitral valvuloplasty, which does not involve puncture and/or dilatation of the inter-atrial septum. No significant difference was found between Doppler- and Gorlin-derived measurements, neither before (1.04 +/- 0.23 vs 1.03 +/- 0.23 cm2, P = ns) nor immediately after (2.14 +/- 0.47 vs 2.12 +/- 0.49 cm2, P = ns) valvuloplasty. Linear regression analysis demonstrated a high degree of correlation between Doppler and Gorlin measurements before (r = 0.778) and after (r = 0.886) the procedure. Good agreement was confirmed by the Bland-Altman method. CONCLUSION: Doppler echocardiography yields accurate measurements of the mitral valve area immediately after retrograde non-transseptal balloon mitral valvuloplasty. This finding supports the hypothesis that the creation of an iatrogenic atrial septal defect during transseptal catheterization may contribute to the poor agreement between Doppler and Gorlin data after balloon mitral valvuloplasty.  相似文献   
90.
Positive selection is an obligatory step during intrathymic T cell differentiation. It is associated with rescue of short-lived, self major histocompatibility complex (MHC)-restricted thymocytes from programmed cell death, CD4/CD8 T cell lineage commitment, and induction of lineage-specific differentiation programs. T cell receptor (TCR) signaling during positive selection can be closely mimicked by targeting TCR on immature thymocytes to cortical epithelial cells in situ via hybrid antibodies. We show that selection of CD4 T cell lineage cells in mice deficient for MHC class I and MHC class II expression can be reconstituted in vivo by two separable T cell receptor signaling steps, whereas a single TCR signal leads only to induction of short-lived CD4+CD8lo intermediates. These intermediates remain susceptible to a second TCR signal for 12-48 h providing an estimate for the duration of positive selection in situ. While both TCR signals induce differentiation steps, only the second one confers long-term survival on immature thymocytes. In further support of the two-step model of positive selection we provide evidence that CD4 T cell lineage cells rescued by a single hybrid antibody pulse in MHC class II-deficient mice are pre-selected by MHC class I.  相似文献   
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