Anteroposterior gradient of epithelial transformation during amphibian intestinal remodeling: immunohistochemical detection of intestinal fatty acid-binding protein

To determine whether the remodeling of the well-organized intestinal epithelium during amphibian metamorphosis is regionally regulated along the anteroposterior axis of the intestine, we raised a polyclonal antibody against the Xenopus laevis intestinal fatty acid-binding protein (IFABP), which is known to be specifically expressed in intestinal absorptive cells, and examined immunohistochemically the differentiation, proliferation, and apoptosis of the epithelial cells throughout X. laevis small intestine. During pre- and prometamorphosis, IFABP-immunoreactive (ir) epithelial cells were localized only in the anterior half of the larval intestine. At the beginning of metamorphic climax, apoptotic cells detected by nick end-labeling (TUNEL) suddenly increased in number in the entire larval epithelium, concurrently with the appearance of adult epithelial primordia. Subsequently, the adult primordia in the anterior part of the intestine developed more rapidly by active cell proliferation than those in the posterior part, and replaced the larval epithelial cells earlier than those in the posterior part. IFABP-ir cells in the adult epithelium were first detectable at the tips of newly formed folds in the proximal part of the intestine. Thereafter, IFABP expression gradually progressed both in the anteroposterior direction and in the crest-trough direction of the folds. These results suggest that developmental processes of the adult epithelium in the X. laevis intestine are regionally regulated along the anteroposterior axis of the intestine, which is maintained throughout metamorphosis, and along the trough-crest axis of the epithelial folds, which is newly established during metamorphosis. Furthermore, the regional differences in IFABP expression along the anteroposterior axis of the intestine were reproduced in organ cultures in vitro. In addition, IFABP expression was first down-regulated and then reactivated in vitro when the anterior part, but not the posterior part, of the larval intestine was treated with thyroid hormone (TH) for extended periods. Therefore, it seems that, in addition to TH, an endogenous factor(s) localized in the intestine itself with an anteroposterior gradient participates in the development of the adult epithelium during amphibian metamorphosis.     

Chronic osteomyelitis of the spine managed with a free flap of latissimus dorsi. A case report

STUDY DESIGN: A patient with intractable spinal osteomyelitis who underwent surgery 12 times with persistent exposed bone is presented. OBJECTIVES: To demonstrate the effectiveness of free-flap grafting for managing difficult spinal osteomyelitis wounds. SUMMARY OF BACKGROUND DATA: Conventional procedures can usually achieve wound closure, but they may not work for advanced cases. METHODS: A free latissimus dorsi flap was transferred for reconstruction. The muscle component was used to obliterate the dead space and cover the exposed bone, and the skin component was used for tension-free closure of the wound. RESULTS: The wound healed dramatically. There was no recurrence of infection at 2-year follow-up evaluation. CONCLUSIONS: For an intractable spinal osteomyelitis wound, a free flap should be considered, although the surgery is difficult. Technical precautions in performing this operation are given.     

Comments and corrections on the contaminated rebar incident in Taiwan

OBJECTIVE: Alternate ways of administering antidepressants when oral intake is impossible are discussed. METHOD: Reviews of 1) the medical circumstances that preclude oral medication administration and 2) novel administration strategies for antidepressants were conducted. RESULTS: Consultation psychiatrists not infrequently encounter depressed patients who lack a functioning gastrointestinal tract and who thus cannot absorb oral antidepressant medication. Under these circumstances, antidepressants can be administered intravenously, by rectal suppository, or topically. CONCLUSION: There are options for administration of antidepressant medication when oral intake is impossible.     

Concomitant rotavirus serotypes 1 and 4 infections in a diarrhoeic child from Belém, Brazil

With the discussion of the quality of medical education in Germany the importance of evaluating the curriculum has grown. A working group of representatives of the German scientific societies for general medicine and the so-called "psychosocial" disciplines in medical education had adapted a questionnaire from Harvard Medical School and tested this version for the first time in summer 1995. 56 teachers and 1250 students took part in this pilot study. The instrument proved to be sufficiently valid to evaluate the quality of different types of teaching lessons. The disciplines (Medical Sociology, Medical Psychology, Social Medicine, General Medicine, Psychotherapy/Psychosomatics) were valued equally with concern to their relevance for medical education. They got significantly better values for quality of teaching and teaching engagement of the professors. It is recommended to notice these results in the actual debate on the reform of the medical curriculum and to include other disciplines in further evaluative investigations.     

A redox-based mechanism for the neuroprotective and neurodestructive effects of nitric oxide and related nitroso-compounds

Congeners of nitrogen monoxide (NO) are neuroprotective and neurodestructive. To address this apparent paradox, we considered the effects on neurons of compounds characterized by alternative redox states of NO: nitric oxide (NO.) and nitrosonium ion (NO+). Nitric oxide, generated from NO. donors or synthesized endogenously after NMDA (N-methyl-D-aspartate) receptor activation, can lead to neurotoxicity. Here, we report that NO.- mediated neurotoxicity is engendered, at least in part, by reaction with superoxide anion (O2.-), apparently leading to formation of peroxynitrite (ONOO-), and not by NO. alone. In contrast, the neuroprotective effects of NO result from downregulation of NMDA-receptor activity by reaction with thiol group(s) of the receptor's redox modulatory site. This reaction is not mediated by NO. itself, but occurs under conditions supporting S-nitrosylation of NMDA receptor thiol (reaction or transfer of NO+). Moreover, the redox versatility of NO allows for its interconversion from neuroprotective to neurotoxic species by a change in the ambient redox milieu. The details of this complex redox chemistry of NO may provide a mechanism for harnessing neuroprotective effects and avoiding neurotoxicity in the central nervous system.