Electron spin density on the axial His ligand of high-spin and low-spin nitrophorin 2 probed by heteronuclear NMR spectroscopy.

The electronic structure of heme proteins is exquisitely tuned by the interaction of the iron center with the axial ligands. NMR studies of paramagnetic heme systems have been focused on the heme signals, but signals from the axial ligands have been rather difficult to detect and assign. We report an extensive assignment of the (1)H, (13)C and (15)N resonances of the axial His ligand in the NO-carrying protein nitrophorin 2 (NP2) in the paramagnetic high-spin and low-spin forms, as well as in the diamagnetic NO complex. We find that the high-spin protein has σ spin delocalization to all atoms in the axial His57, which decreases in size as the number of bonds between Fe(III) and the atom in question increases, except that within the His57 imidazole ring the contact shifts are a balance between positive σ and negative π contributions. In contrast, the low-spin protein has π spin delocalization to all atoms of the imidazole ring. Our strategy, adequately combined with a selective residue labeling scheme, represents a straightforward characterization of the electron spin density in heme axial ligands.

Dimensions of the cranium and of the cranial cavity andintracranial volume in goats (Capra hircus LINNAEUS, 1758)

The aim of this project is to determine the dimensions of the cranium and the cranial cavity and the intracranialvolume in goats, using 64 adults. The dimensions of the cranium and cranial cavity were measured throughmetric tape and paquimeter, considering the intervals of the largest distances. To determine the intracranialvolume, balloons of latex were introduced in the cranial cavity, through the magnum foramen, later on, filledwith water that was transferred for graduate test tube. The average and the standard deviation of length, widthand height of the cranium, in millimeters, were respectively: 218.01 ± 6.96, 120.17 ± 10.01 and 108.14 ± 4.46.The average and the standard deviation of length, width, height, in millimeters, and of the volume of thecranial cavity, in cubic centimeters, were respectively: 109.31 ± 7.25, 61.36 ± 4.51, 63.85 ± 2.88 and119.31 ± 12.21. It was observed that, the width of the cranium possesses positive significant correlationswith the length (r = 0.6865), with the height (r = 0.5644) and with the intracranial volume (r = 0.5436).They were still established, positive significant correlations among the height of the cranial cavity, with thelength (r = 0.5682) and with the intracranial volume (r = 0.5473). Differences were evidenced between malesand females, in relation to the dimensions of the cranium and cranial cavity. There wasn’t difference of theintracranial volume in function of the sex of the goats.

O sistema imune inato intestinal em pacientes com estrongiloidíase / The innate intestinal immune system in patients with strongyloidiasis

Foram estudados fragmentos da mucosa duodenal obtidos de nove pacientes apresentando sintomas leves de estrogiloidiase, nove com sintomas moderados, sete com sintomas graves e sete indivíduos aparentemente normais. A muramidase(lisozima) foi imunocitoquimicamente demonstrada em cortes contracorados pela técnica do PAS. Havia aparente aumento progressivo na secreçao de muramidase pela célula de Paneth aaacompanhado o agravamento dos sintomas, näo obstante o fato de que a sua populaçao permanecesse constante. Decréscimo progressivo no número de células caliciformes foi observado enquanto, concomitantemente, haavia aumento na populaçao de células intermediarias. Esses resultados foram interpretados como a indicaçao da participaçao do sistema imune inato intestinal no estabelecimento da interaçao Strongyloides stercoralis/hospedeiro, através do aumento da secreçao da enzima mucolítica muramidase

Intra-abdominal sepsis: an immunocytochemical study of the small intestine mucosa.

AIM: To investigate immunocytochemical changes in intestinal tissues from patients with intra-abdominal sepsis, and to relate the changes to the possibility of enhanced bacterial adhesion and translocation. METHODS: Tissues from 17 patients suffering from intra-abdominal sepsis and from controls were sectioned and stained immunocytochemically for IgA, IgM, secretory component, J chain, and HLA-DR. Differences in the distribution and characteristics of positively staining cells between the patient groups were assessed. RESULTS: Patients with intra-abdominal sepsis had noticeable reductions in numbers of IgA and IgM plasma cells, reduced J chain staining, and had little immunoglobulin on the surfaces of enterocytes. In contrast, HLA-DR positive cells were increased in the sepsis compared with the control group. The plasma cells present showed cytological changes suggestive of apoptosis. CONCLUSIONS: Stress associated with sepsis and its immediate causes might result in increased plasma glucocorticoid levels that bring about apoptosis of mucosal plasma cells (or their precursors). The consequent reduction in expression of IgA and IgM may favour bacterial adhesion to the enterocytes and facilitate bacterial translocation into the tissues.

A heme-binding protein from hemolymph and oocytes of the blood-sucking insect, Rhodnius prolixus. Isolation and characterization.

A heme-binding protein has been isolated and characterized from both the hemolymph and oocytes of the blood-sucking insect, Rhodnius prolixus. The protein from both sources is identical in most aspects studied. The Rhodnius heme-binding protein (RHBP) is composed of a single 15-kDa polypeptide chain coiled in a highly alpha-helical structure which binds non-covalently one heme/polypeptide chain. This RHBP is not produced by limited degradation of hemoglobin from the vertebrate host, since specific polyclonal antibodies against it do not cross-react with rabbit hemoglobin, and since it differs from hemoglobin in having a distinct amino-acid composition and NH2-terminal sequence. The spectrum of the dithionite-reduced protein has peaks at 426, 530, and 559 nm and resembles that of a b-type cytochrome. RHBP from hemolymph is not saturated with heme and promptly binds heme added to the solution. The oocyte protein, on the other hand, is fully saturated and is not capable of binding additional heme.