A Study on the Quality and Identity of Brazilian Pampa Biome Honey: Evidences for Its Beneficial Effects against Oxidative Stress and Hyperglycemia.

We characterized, for the first time, the quality and identity of Brazilian Pampa biome honey and its antioxidant properties in vitro (FRAP, DDPH and ABTS). The potential protective effect of honey against oxidative stress induced by iron (Fe) and paraquat, (PQ) in a Drosophila melanogaster model (in vivo) was also tested. The results indicated that all honey samples tested showed antioxidant activity in vitro. Flies treated with honey showed increased lifespan and were protected against oxidative stress induced by Fe and PQ. Despite the high concentration of sugars in honey (approximately 70-80%), our results demonstrate a hypoglycemic-like effect of honey in Drosophila. Thus, this study demonstrates the high quality of Brazilian Pampa biome honey as well as its significant antioxidant activity in vitro and in vivo, pointing to the potential use of this natural product as an alternative in the therapy of oxidative stress-associated diseases.

Characterization of the temporo-spatial effects of chronic bilateral intrahippocampal cannulae on interleukin-1beta

The implantation of a foreign object in the brain produces an acute neuroinflammatory state in which glia (astrocytes and microglia) may remain chronically activated in response to the inert foreign object. Activated glia can exhibit a sensitized pro-inflammatory response to immunogenic stimuli. This may be relevant to intracranial cannula implantation, which is commonly used to administer substances directly into the brain. If intracranial cannulation activates glia, a subsequent neuroinflammatory stimulus might induce a potentiated pro-inflammatory response, thereby introducing a potential experimental confound. We tested the temporal and spatial responses of interleukin-1β (IL-1β) to an acute immune challenge produced by lipopolysaccharide (LPS) in animals with chronic bilateral intrahippocampal cannulae implants (stainless steel). Cannulation increased the gene expression of the microglia activation antigens MHC II and CD11b, but not the astrocyte antigen GFAP. Moreover, this activation was temporally and spatially dependent. In addition, IL-1β mRNA, but not IL-1β protein, was significantly elevated in cannulated animals. Administration of LPS, however, significantly potentiated the brain IL-1β response in cannulated animals, but not in stab wounded or naïve animals. This IL-1β response was also temporo-spatially dependent. Thus, the pro-inflammatory sequelae of intracranial cannulation should be considered when designing studies of neuroinflammatory processes(AU)

Phosphoglycosylation of a secreted acid phosphatase from Leishmania donovani.

The secreted acid phosphatase (SAcP) of L.donovani is a heterogeneous glycoprotein that displays a wide array of N- and O-linked glycosylations. The O-linked sugars are of particular interest due to their similarity to the phosphoglycan structures of the major lipophosphoglycan surface antigen and released phosphoglycan (Turco et al., 1987; Greis et al., 1992). This study describes a structural analysis of the SAcP O-linked glycosylations using mass spectroscopy, amino acid sequencing, and enzymatic carbohydrate sequencing. Analysis of glycan chain lengths and peptide glycosylation site distribution was performed, revealing that the average O-linked structure was approximately 32 repeat units in length. Amino acid sequence analysis of glycosylated peptides showed that phosphoglycosylations did not occur randomly but were localized to specific serine residues within an array of degenerate serine/threonine-rich repeat sequences localized in the C-terminus. No evidence was obtained for modification of threonine residues. The observed pattern suggested that a consensus sequence may exist for localization of phosphoglycan structures.

Long-term protection of mice against Leishmania major with a synthetic peptide vaccine.

A single synthetic T cell epitope (PT3), obtained from the histidine zinc-binding region of the metalloprotease gp63, was employed in a vaccine trial using two virulent strains of L. major. When a single subcutaneous injection of PT3 was delivered with the Thl stimulating adjuvant poloxamer 407, BALB/c mice were protected for at least 10 months against the disease. Vaccinated mice were largely free of lesions on termination of the experiment. Protection was similar for both L. major MRHP/SU/59 Neals and L. major WHOM/IR/-/173 strains which manifest different disease sequelae. Thus, these data provide evidence that a single subcutaneous injection of a single synthetic T cell epitope is sufficient to provide long-lasting protection against two highly virulent strains of L. major in BALB/c mice.

Periplasmic and fimbrial SefA from Salmonella enteritidis.

Salmonella enteritidis produces thin, filamentous fimbriae composed of the fimbrin subunit SefA. Although insoluble in most detergents and chaotropic agents, these fimbriae were soluble at pH 10.5. Furthermore, in sodium dodecyl sulfate, these fibers depolymerized into monomers, dimers and other multimers of SefA, which precipitated on removal of the detergent. In contrast, unassembled periplasmic SefA fimbrins purified from Escherichia coli expressing cloned sefA and sefB were readily soluble in aqueous solution. Fimbrial and periplasmic SefA also differed in their reaction with an anti-SEF14 monoclonal antibody and in their surface hydrophobicity, indicating that the two forms had different properties. Precise mass measurements of periplasmic and fimbrial SefA by mass spectroscopy showed that these variations were not due to post-translational modifications. Periplasmic SefA consisted primarily of intact as well as some N-terminally truncated forms. The main 24 amino acid, N-terminally truncated form of periplasmic SefA was present as a 12.2 kDa monomer which had a low tendency to dimerize whereas intact periplasmic SefA was present as a 34.1 kDa homodimer. Intact periplasmic SefA also formed stable multimers at low concentrations of chemical cross-linker but multimerization of the truncated form required high concentrations of protein or cross-linker. Thus, SefA fimbrins appear to multimerize through their N-termini and undergo a conformational change prior to assembly into fibers. Within these fibers, subunit-subunit contact is maintained through strong hydrophobic interactions.

Neurologic status and prognosis after cardiopulmonary arrest: I. A retrospective study.

A retrospective survey of survivors of cardiorespiratory arrest included 34 patients. Twenty-one had a good outcome neurologically and 13 were seriously impaired. Depth and duration of postarrest coma correlated significantly with poor neurologic function. Seventy percent of the seriously impaired patients never regained consciousness and none emerged from coma within 5 days; 90 percent of patients with good outcome were alert within 18 hours after resuscitation. Coma motor unresponsiveness, absent pupillary light reflexes, and absent oculocephalic responses were closely associated with dismal prognosis for neurologic functioning. This retrospective study cannot provide a basis for discontinuation of life support at any specific time.

Cerebral atherosclerosis and its relationship to selected diseases in Nigerians: a pathological study.

Factors which are known to be associated with cerebral atherosclerosis were evaluated in Nigerian Africans. Of 465 autopsied adult Nigerians, 62 (13%) had cerebral atherosclerosis. The frequency and severity of atherosclerosis among Nigerians with hypertension, particularly male subjects, were higher than in normotensives. Although there was a similar frequency of hypertension among autopsied Nigerian and Minnesota Caucasian populations, the severity and extent of atherosclerosis were greater in the Minnesota Caucasian populations, the severity and extent of atherosclerosis were greater in the Minnesota population. The relatively short duration of hypertension in the Nigerian before death might be an important factor which did not permit progressive development of cerebral atherosclerosis. Other factors which predisposed the Nigerian to increased frequency and severity of atherosclerosis included increased heart weight and diabetes mellitus. The relatively low frequency of cerebrovascular disease in the Nigerian may be explained on the basis of a low degree of cerebral atherosclerosis and relatively short duration of hypertension.