Calretinin immunoreactive structures in the human hippocampal formation

The calcium-binding protein calretinin is present in an intrinsic GABAergic and an extrinsic non-GABAergic system in the rat and monkey hippocampal formation. Important species differences have been noted in hippocampal cell types immunostained for calretinin and the termination pattern of calretinin containing hypothalamic afferents in the hippocampus. In the present study, calretinin-containing neurons were visualized using immunocytochemistry in the human hippocampal formation of individuals which showed no significant neuropathological alterations. Calretinin-immunoreactivity was present exclusively in non-granule cells of the dentate gyrus and in non-pyramidal cells of Ammon's horn. Calretinin-positive neurons were found most frequently in the hilus of the fascia dentata and in strata radiatum and lacunosum-moleculare of CA1, whereas neurons in CA2 and CA3 were rarely immunostained. The majority of calretinin-immunoreactive neurons were small, bipolar or fusiform neurons. The dendritic trees of the calretinin-positive neurons were, for the most part, parallel to the dendrites of the principal cells. In the hilus, however, we observed cells with dendrites restricted to the hilar area. These dendrites were parallel to the granule cell layer. In the stratum lacunosum-moleculare, neurons with dendrites oriented parallel to the hippocampal fissure were frequently detected. In general, dendrites were smooth or sparsely spiny, displaying small conventional spines. The axons usually emerged from the proximal dendrite and could be followed over long distances. Axons were thin, had small varicosities and displayed only few collaterals which branched relatively far away from the cell body. Distinct bands of darkly stained calretinin-positive fibers occupied the innermost portion of the dentate molecular layer and the pyramidal cell layer of CA2. This distribution of calretinin-immunoreactive structures in the human hippocampus is similar to that observed in other primates but differs from that described in lower mammals, i.e., the rat. Our findings suggest that primates may share a common hippocampal calretinin-containing system, presumably both the intrinsic GABAergic and the extrinsic hypothalamic non-GABAergic components.     

Structure and stability of monomeric lambda repressor: NMR evidence for two-state folding

The absence of equilibrium intermediates in protein folding reactions (i.e., two-state folding) simplifies thermodynamic and kinetic analyses but is difficult to prove rigorously. We demonstrate a sensitive method for detecting partially folded species based on using proton chemical shifts as local probes of structure. The coincidence of denaturation curves for probes throughout the molecule is a particularly stringent test for two-state folding. In this study we investigate a new form of the N-terminal domain of bacteriophage lambda repressor consisting of residues 6-85 (lambda 6-85) using nuclear magnetic resonance (NMR) and circular dichroism (CD). This truncated version lacks the residues required for dimerization and is monomeric under the conditions used for NMR. Heteronuclear NMR was used to assign the 1H, 15N, and backbone 13C resonances. The secondary and tertiary structure of lambda 6-85 is very similar to that reported for the crystal structure of the DNA-bound 1-92 fragment [Beamer, L. J., and Pabo, C. O. (1992) J. Mol. Biol. 227, 177-196], as judged by analysis of chemical shifts, amide hydrogen exchange, amide-alpha coupling constants, and nuclear Overhauser enhancements. Thermal and urea denaturation studies were conducted using the chemical shifts of the four aromatic side chains as local probes and the CD signal at 222 nm as a global probe. Plots of the fraction denatured versus denaturant concentration obtained from these studies are identical for all probes under all conditions studied. This observation provides strong evidence for two-state folding, indicating that there are no populated intermediates in the folding of lambda 6-85.     

The pharmacology of FMRFamide-related neuropeptides in nematodes: new opportunities for rational anthelmintic discovery?

The chemotherapeutic control of helminth parasites is compromised by the limited number of classes of anthelmintic drugs. Discovery of novel anthelmintics is impeded by the lack of novel screening technologies that overcome the difficulties inherent in screens based on whole organism toxicity. The development and implementation of mechanism-based screens for new anthelmintics offers great promise for the revitalization of antiparasitic drug discovery. However, mechanism-based screens must be based on a thorough understanding of the proteins or processes that offer the best chance for selective chemotherapeutic intervention. Basic research on the characterization of nematode FMRFamide-related peptides (FaRPs) has revealed that these peptides are ubiquitously distributed in helminths. Chemical identification of a number of nematode FaRPs has been achieved, and these peptides have potent and profound effects on the nematode neuromuscular system. Physiological processes mediated by nematode FaRPs (and other helminth neuropeptides) offer potential targets for the discovery of novel anthelmintics.     

Effect of rapamycin on renal allograft survival in canine recipients treated with antilymphocyte serum, donor bone marrow, and cyclosporine

Rapamycin (Rapa) monotherapy can promote renal allograft survival in dogs, but it is very toxic. To attempt to augment the effectiveness of Rapa and reduce its toxicity in a tolerance induction protocol, canine renal allograft recipients were treated briefly with antilymphocyte serum (ALS), donor bone marrow cells (BMC), and a limited course of cyclosporine (CsA). Rapa had little effect when CsA-treated recipients were given ALS on days -5 to -1 and BMC on day +1. When combined with CsA given days +13 to +42, ALS on days -5 to +7, and BMC on day +10, Rapa at 0.3 mg/kg on day +8 plus alternate days +15 to +39 significantly increased overall survival and was compatible with long-term survival after immunosuppression (6 grafts, 1 graft > 212 days, 1 graft > 470 days). Rapa appeared to prevent early rejections that can occur during treatment with these ALS/BMC/CsA protocols. Little toxicity of Rapa was observed with any treatment.     

A prospective study of primary and secondary risk factor management in stroke patients

Stroke is a common event which often results in death or major loss of independence with immense human and financial costs, so identification of patients at risk, and prevention of stroke at the individual and population levels, is a high clinical and health priority. From August 1993 to July 1994, 468 stroke patients admitted to our hospital were assessed for the presence of stroke risk factors. All patients were followed up in hospital, and on discharge or death all hospital records were reviewed. We show that many risk factors remain uncorrected in stroke patients and that preventive measures are less than ideal at the community and hospital levels alike.     

Bronchopulmonary sequestration with MR angiographic evaluation. A case report

To determine the influence of various oestrogenenic administrations on lipid response, 63 women with total abdominal hysterectomy and bilateral anexectomy were studied before and 6 and 12 months after receiving 17 beta-oestradiol by different means. The effect on the levels of lipids and lipoproteins of the 2 mg/24 h administration of oestradiol valerate was compared with 1.5 mg/day of percutaneous 17 beta-oestradiol and 0.05 mg/day of transdermic oestradiol. The treatments were given continuously over a year. The oestradiol valerate produced a statistically significant increase (P < 0.05) of the HDL-C levels both after 6 and 12 months (10.6% vs. 11.6%). A significant increase was also observed (P < 0.05) in the Apo AI levels during the treatment (18 and 25%). On the other hand, unfavorable side effects with oestradiol were not produced, either percutaneous or transdermic, on lipid plasmatic or lipoprotein levels. These data show the benefit of oral oestrogenic therapy and the maintenance of the lipid profile in percutaneous and transdermic therapies in oophorectomized women.     

Gene mapping from a bovine 1;29 DNA library prepared with chromosome microdissection

The relative concentrations of IgM and IgG antibodies (Ab) to Schistosoma mansoni soluble egg antigen (SEA) were evaluated in paired samples of venous blood sera and buffer-eluates of capillary blood drops dried on filter papers. The samples were obtained from school children at early and chronic stages of schistosomiasis diagnosed on the basis of history, clinical symptomatology and parasitological criteria. Enzyme-linked immunosorbent assay (ELISA), simultaneously performed, revealed paired samples to display comparable Ab levels in all cases. Samples from children with early schistosomiasis had specific IgM:IgG ratios greater than 1 [optical densities (O.D.) in sera and blood eluates of 0.77 +/- 0.32 and 0.68 +/- 0.30, respectively for IgM and 0.52 +/- 0.25 and 0.50 +/- 0.25 for IgG]. This ratio, however, was less than 1 in samples from chronically infected children (O.D. of 0.20 +/- 0.11 and 0.20 +/- 0.11 for IgM and 0.69 +/- 0.33 and 0.73 +/- 0.32 for IgG). The specific advantages of this simplified technique are the use of anti-SEA Abs in fingerstick blood eluates, rather than sera of venous blood to serologically diagnose schistosomiasis and to differentiate early from chronic infections particularly when used for mass screening, such as epidemiologic surveys.