Hantavirus pulmonary syndrome in Uberaba,Minas Gerais,Brazil

This report describes the epidemiological and clinical-evolutive characteristics of eight patients with hantavirus pulmonary syndrome (HPS) in Uberaba, Minas Gerais, Brazil. A positive history of contact with rodents was present in 100% of the cases. The time between the onset of symptoms and hospital care was, on average, 3.6 days. All patients showed clinical and laboratory findings suggestive of HPS. Elevated urea and creatinine levels were observed in 6 (75%) cases, PO2 was < 60 mmHg in 100% of the cases, and a chest X-ray demonstrated a bilateral interstitial-alveolar infiltrate. The diagnosis was confirmed by the detection of IgM antibodies against Sin Nombre virus by ELISA. Three patients died as a direct consequence of HPS.     

A link between maze learning and hippocampal expression of neuroleukin and its receptor gp78

Neuroleukin (NLK) is a multifunctional protein involved in neuronal growth and survival, cell motility and differentiation, and glucose metabolism. We report herein that hippocampal expression of NLK and its receptor gp78 is associated with maze learning in rats. First, mRNA levels of NLK and gp78 were significantly increased in hippocampi of male Fischer-344 rats following training in the Stone T-maze and the Morris water maze. Second, a parallel increase was found in hippocampal NLK and gp78 proteins after maze learning. Third, NLK and gp78 mRNA and protein expression in hippocampus was reduced in a group of aged rats that showed more errors during the acquisition of the Stone maze task as compared with young rats. Finally, application of recombinant NLK to hippocampal neurons significantly enhanced glutamate-induced ion currents, functional molecular changes that have been correlated with learning in vivo. Taken together, our results identify a novel association of hippocampal expression of NLK and its receptor gp78 with rat maze learning. Interaction of NLK with gp78 and subsequent signaling may strengthen synaptic mechanisms underlying learning and memory formation.     

ProNGF induces p75-mediated death of oligodendrocytes following spinal cord injury

The neurotrophin receptor p75 is induced by various injuries to the nervous system, but its role after injury has remained unclear. Here, we report that p75 is required for the death of oligodendrocytes following spinal cord injury, and its action is mediated mainly by proNGF. Oligodendrocytes undergoing apoptosis expressed p75, and the absence of p75 resulted in a decrease in the number of apoptotic oligodendrocytes and increased survival of oligodendrocytes. ProNGF is likely responsible for activating p75 in vivo, since the proNGF from the injured spinal cord induced apoptosis among p75(+/+), but not among p75(-/-), oligodendrocytes in culture, and its action was blocked by proNGF-specific antibody. Together, these data suggest that the role of proNGF is to eliminate damaged cells by activating the apoptotic machinery of p75 after injury.     

Regulation of Wnt signaling during adipogenesis

We have identified Wnt10b as a potent inhibitor of adipogenesis that must be suppressed for preadipocytes to differentiate in vitro. Here, we demonstrate that a specific inhibitor of glycogen synthase kinase 3, CHIR 99021, mimics Wnt signaling in preadipocytes. CHIR 99021 stabilizes free cytosolic beta-catenin and inhibits adipogenesis by blocking induction of CCAAT/enhancer-binding protein alpha and peroxisome proliferator-activated receptor gamma. Preadipocyte differentiation is inhibited when 3T3-L1 cells are exposed to CHIR 99021 for any 24 h period during the first 3 days of adipogenesis. Consistent with this time frame of inhibition, expression of Wnt10b mRNA is suppressed upon induction of differentiation, with a 50% decline by 6 h and complete inhibition by 36 h. Of the agents used to induce differentiation, exposure of 3T3-L1 cells to methyl-isobutylxanthine or cAMP is sufficient to suppress expression of Wnt10b mRNA. Inhibition of adipogenesis by Wnt10b is likely mediated by Wnt receptors, Frizzled 1, 2, and/or 5, and co-receptors low density lipoprotein receptor-related proteins 5 and 6. These receptors, like Wnt10b, are highly expressed in preadipocytes and stromal vascular cells. Finally, we demonstrate that disruption of extracellular Wnt signaling by expression of secreted Frizzled related proteins causes spontaneous adipocyte conversion.     

Midline (dermoid) cysts of the floor of the mouth: report of 16 cases and review of surgical techniques

A retrospective review of 16 cases of midline (dermoid) cysts of the floor of the mouth is presented, evaluating the different surgical approaches. Sixteen cases of patients with a diagnosis of midline cyst of the floor of the mouth, treated at the Maxillofacial Surgery Department of the School of Medicine and Surgery of the "Federico II" University of Naples (Naples, Italy), were observed over a 10-year period, between 1988 and 1998; age, sex, localization, diagnostic technique, and type of treatment were evaluated. Male patients were more frequently affected, with a male-to-female ratio of 3:1 (12:4 cases). Patients ranged in age from 5 to 51 years (average age, 27.8 years). The preoperative assessment was made using ultrasonography in all cases but one, computed tomography in eight cases, and magnetic resonance imaging in three cases. Regarding surgical techniques used, a transcutaneous approach was adopted for median geniohyoid cysts, an extended median glossotomy technique was used for very large median genioglossal cysts, a median glossotomy technique was used for median genioglossal cysts, and a midline incision of the oral mucosa along the lingual frenulum was used for sublingual cysts. During the postoperative course, there were no complications except for modest edema in three cases. Follow-up ranged between 24 months and 12 years; no relapses or malignant changes were observed. In the authors' experience, the intraoral approach was also effective for the treatment of large lesions and led to very good cosmetic and functional results, whereas the extraoral incision was necessary only when the cysts were under the geniohyoid muscle.     

Plant regeneration from callus cultures of <Emphasis Type="Italic">Maclura tinctoria</Emphasis>, an endangered woody species

Summary Some native species produce seeds with a low frequency of germination accompanied with a period of dormancy. These features make it difficult to produce new phenotypes through sexual propagation. Maclura tinctoria has been considered an endangered species due to extensive use of its wood and low frequency of seed germination. The objective of the present study is to establish an in vitro propagation system for this species. Organogenic friable callus formation from nodal segments has been obtained using woody plant medium (WPM) supplemented with 10.74 μM 1-naphthaleneacetic acid (NAA)+4.43 μM 6-benzylaminopurine (BA). Results indicate that the highest frequency of shoot formation is observed when WPM supplemented with 4.03 μM NAA+4.43 BA is used. For root formation, the use of WPM medium (pH adjusted to 7.0) supplemented with 23.62 μM indole-3-butyric acid (IBA) and 4.7gl⁻¹ activated charcoal is recommended. For acelimatization, subjecting rooted plantlets to 70%, 50%, and 30% mesh screen, each successively for a period of 7 d, has resulted in 97% plantlet survival.     

A long acidic domain affects the chromatographic behaviour of a neuronal adaptor protein on DEAE-Sepharose

The stepwise chromatographic behaviour on DEAE-Sepharose of rat Fe65, a neuronal protein, was tested, using as eluants KCl, CaCl2, and MgCl2. Assays by western blot showed that Fe65 was eluted by CaCl2, at a ionic strength 20% lower than that of MgCl2 or KCl. Interestingly, in the case of a truncated Fe65, lacking a glutamic acid rich region at the N-terminus, the ionic strengths of the various eluants were almost identical. These results suggested a possible inhibitory role of calcium ions in the binding of the protein to DEAE and a specific affinity of these ions for long acidic stretches.     

Different behavior toward racemization in basic media from chiral analogs of clofibric acid, the active metabolite of the antilipidemic drug clofibrate

Some chiral analogs of clofibric acid, the active metabolite of the antilipidemic drug clofibrate, show different configurational stability in basic conditions. Also, extensive racemization occurs when the corresponding optically active acid chlorides are treated with 3 alpha-tropanol, whereas no racemization takes place with 3 alpha-tropanol as hydrochloride salt and with 3 beta-tropanol and 1-methyl-4-hydroxy-piperidine as either the free base or hydrochloride salt. For these aminoalcohols, experimental evidence supports the hypothesis that a ketene intermediate is involved in the racemization process. Formation of intramolecular hydrogen bond is evoked to explain the different ability of aminoalcohols to induce ketene formation and consequent racemization.