Urorectal septum malformation sequence: report of thirteen additional cases and review of the literature

We present the findings of 13 additional cases of the urorectal septum malformation (URSM) sequence, and review the literature. The URSM sequence consists of ambiguous genitalia concurrent with absence of perineal and anal openings. The sex ratio of the 13 new cases was 7 males to 6 females and from the literature 21 males and 28 females. In addition, 11 of the 13 new cases had anorectal atresia with 5 of the cases also having partial agenesis of the colon. Bilateral renal agenesis was present in 3 of the 13 cases, unilateral renal agenesis occurred in 6, and dysplastic kidneys were found in 10. The URSM sequence is a lethal condition with long-term survival reported in only 3 of a total of 62 literature and new cases. Recurrence of this condition has not been reported.     

The causes and functions of mitochondrial proton leak

Important progress has been reported over the past year on evaluation and standardization of disease activity variables in rheumatoid arthritis and their relation to outcome measures. Core sets of variables have been established both in the United States and Europe, showing a high degree of resemblance. A recently proposed classification of antirheumatic drugs seeks to make a clear distinction between drugs that modify symptoms and those that actually control the disease. This classification may have a definite impact on design and methodology of future clinical trials.     

Injury-related factors and conditions down-regulate the thrombin receptor (PAR-1) in a human neuronal cell line

Previous studies have demonstrated that thrombin can induce potent effects on neural cell morphology, biochemistry, and viability. Nearly all of these effects are mediated by proteolytic activation of the thrombin receptor (PAR-1). Mechanisms of PAR-1 regulation in several nonneural cell types have been shown to be novel and cell type specific; however, little is known about PAR-1 regulation in neural cells. In the present study, PAR-1 cell surface expression and regulation were examined in a transformed retinoblast (Ad12 HER 10) cell line using radioiodinated anti-PAR-1 monoclonal antibodies ATAP2, which recognizes intact and cleaved receptors, and SPAN12, which is specific for the intact form of the receptor. Scatchard analysis revealed high-affinity, specific binding to a single affinity class of receptors: K(D) = 3.13 and 5.25 nM, Bmax = 190.1 and 67.8 fmol/mg of protein for 125I-ATAP2 and 125I-SPAN12, respectively. Specificity for PAR-1 was confirmed by demonstrating rapid and near complete decreases for both antibodies following treatment with thrombin or PAR-1 activating peptide (SFLLRN). Differential antibody binding was used to demonstrate rapid and near complete thrombin-induced PAR-1 cleavage and internalization, with protein synthesis-dependent replacement of intact receptors occurring over longer time intervals, but only minimal recycling of cleaved receptors. A variety of factors and conditions were screened for their effects on PAR-1 expression. Significant decreases in PAR-1 expression were induced by the protein kinase C activator phorbol 12-myristate 13-acetate (87% at 3 h), the phospholipid inflammatory mediator lysophosphatidic acid (32% at 3 h), and the injury-related condition hypoglycemia (64 and 100% at 24 h in the absence and presence of dibutyryl cyclic AMP, respectively). The effect of hypoglycemia was shown by RNase protection to be at least partially pretranslational. Finally, thrombin's ability to enhance hypoglycemia-induced cell killing correlated temporally with PAR-1 cell surface expression.     

Teeth or implants: a 1990s dilemma

Using endosseous implants to replace missing teeth is a highly predictable process when the precepts defined by Br?nemark are followed. The question of whether or not to extract periodontally compromised teeth, however, remains controversial. This article presents a case report illustrating some of the concerns involved when treating a patient with a combination of natural teeth and implants, and proposes several compelling questions regarding the treatment decisions made in this case.     

Meningiomas. Epidemiological and anatomopathological study of 340 cases

The authors have retrospectively reviewed all tumors of central nervous system (CNS) operated at the most important neurosurgery hospitals of Curitiba in a 5-year period (1990-1994) and found 304 (22.4%) cases of meningioma. Age mean of the patients was 48.5 years, with a range of 3 to 90 years. A marked female preponderance (68.7%) was noted. The most common tumor location was brain (n = 280) and the remaining cases occurred in spinal cord (n = 10), cerebellum (n = 9) and cranial nerves (n = 5). Histologically, there were 294 (96.7%) meningiomas of the classical type, six malignant or anaplastic, three atypical and one papillary. Two hundred and sixty seven classical meningiomas were from the meningotelial subtype, ten psamomatousos, five fibroblastic, five microcystic, five transicional and two angiomatous. The authors conclude that meningiomas are one of the most common group of primary neoplasias of CNS and the definition of malignancy in those tumors is beset by frequent discordance between histologic and biologic features.