Role of Paracoccidioides brasiliensis cell wall fraction containing beta-glucan in tumor necrosis factor-alpha production by human monocytes: correlation with fungicidal activity

The polysaccharide fraction of Paracoccidioides brasiliensis mycelial cell wall (F1 fraction), the active component of which is composed of beta-glucan, was investigated in regard to the activation of human monocytes for fungal killing. The cells were primed with interferon-gamma (IFN-gamma) or F1 (100 and 200 mug ml(-1)) or F1 (100 and 200 mug ml(-1)) plus IFN-gamma for 24 h and then evaluated for H2O2 release. In other experiments, the cells were pretreated with the same stimuli, challenged with a virulent strain of P. brasiliensis and evaluated for fungicidal activity and levels of tumor necrosis factor (TNF-alpha) in the supernatants. F1 increased the levels of H2O2 in a similar manner to IFN-gamma. However, a synergistic effect between these two activators was not detected. on the contrary, a significant fungicidal activity was only obtained after priming with IFN-gamma plus F1. This higher activity was associated with high levels of TNF-alpha in the supernatants of the cocultures. Overall, P. brasiliensis F1 fraction induced human monocytes to release relatively high levels of TNF-alpha, which, in combination with IFN-gamma, is responsible for the activation of human monocytes for effective killing of P. brasiliensis.

Glucose- and insulin-induced phosphorylation of the insulin receptor and its primary substrates IRS-1 and IRS-2 in rat pancreatic islets

The presence of tyrosine-phosphorylated proteins was studied in cultured rat pancreatic islets, Immunoblotting performed with total extracts of islets cultured in the presence of 1.8 or 5.6 mM glucose revealed at least three distinct tyrosine-phosphorylated bands (25 kDa, 95 kDa and 165-185 kDa). After 12 h incubation in medium containing 1.8 mM glucose, a pulse exposition to 11 or 22 mM glucose or to 10(-7) M insulin led to a substantial increase in the phosphorylation of all three bands, with no appearance of novel bands. Immunoprecipitation with specific antibodies demonstrated that the signal detected at 95 kDa corresponds to the beta subunit of the insulin receptor (IR) while the band at 165-185 kDa corresponds to the early substrates of the insulin receptor, IRS-1 and IRS-2. Immunoprecipitation with IRS-I or IRS-2 antisera detected their association with the lipid metabolizing enzyme phosphatidylinositol 3-kinase (PI 3-kinase), Thus, this is the first demonstration that elements involved in the insulin-signalling pathway of traditional target tissues are also present in pancreatic islets and are potentially involved in auto- and paracrine-signalling in this organ.

Tumor necrosis factor-alpha in gestation and puerperium of women with gestational hypertension and pre-eclampsia

Problem High plasma levels of tumor necrosis factor-alpha (TNF-alpha) in pregnant women have been associated with the pathogenesis of pre-eclampsia (PE). This study evaluated TNF-alpha plasma levels and monocyte production in gestational hypertension (GH) and PE during gestation and at puerperium.Method of study This study included 128 women, of whom 20 were non-pregnant (NP) normotensive (NT), and 108 were pregnant: 36 NT, 27 with GH, and 45 with PE. Peripheral blood plasma was used for TNF-alpha and uric acid determination. TNF-alpha was determined in plasma and lipopolysaccharide (LPS)-stimulated and non-stimulated monocyte supernatants by L929 bioassay.Results Tumor necrosis factor-alpha and uric acid plasma levels were higher in PE than in GH pregnancies. In both hypertensive groups, these parameters positively correlated and were significantly more elevated than in NT and NP women. TNF-alpha plasma levels and monocyte production were higher in hypertensive than in NT women during gestation, and significantly decreased at puerperium. Although decreased, TNF-alpha release in LPS-stimulated PE monocytes, was still significantly higher than in the other pregnant groups.Conclusion In vivo monocyte activation in GH and PE pregnant women was characterized by in vitro TNF-alpha production. The fact that higher circulating concentrations of TNF-alpha and uric acid were observed in PE than in GH suggests an association with disease severity.

Prospective Evaluation of Laparoscopic Pancreatic Biopsies in 11 Healthy Cats

BackgroundDefinitive diagnosis of feline pancreatic disease is dependent on histologic examination of biopsies.HypothesisLaparoscopic punch biopsy of the pancreas does not significantly affect pancreatic health or clinical status of healthy cats, and provides an adequate biopsy sample for histopathology.AnimalsEleven healthy female domestic shorthair cats.MethodsEffects of laparoscopic pancreatic visualization alone in 5 cats compared with laparoscopic pancreatic visualization and punch biopsy in 6 cats were studied. Temperature, pulse, and respiratory rate, physical examination, and daily caloric intake were evaluated for 1 week before and 1 week after the procedure. Pain scores (simple descriptive score and dynamic interactive visual assessment score) were evaluated hourly during the 1st 6 hours postprocedure. Complete blood cell counts, serum biochemical profiles, serum feline pancreatic lipase immunoreactivity, and urine specific gravity were evaluated before the procedure and at 6, 24, and 72 hours postprocedure. One month postprocedure, during sterilization, the pancreas was reassessed visually in all cats, and microscopically in the biopsy group.ResultsFor all variables evaluated, there were no significant differences between biopsy and control cats. Re-evaluation of the pancreatic biopsy site 1 month later documented a normal tissue response to biopsy. The laparoscopic punch biopsy forceps provided high-quality pancreatic biopsy samples with an average size of 5 mm x 4 mm on 2-dimensional cut section.Conclusions and Clinical ImportanceLaparoscopic pancreatic biopsy is a useful and safe technique in healthy cats.

Herpesvirus infection with severe lymphoid necrosis affecting a beaked whale stranded in the Canary Islands

This report describes the pathologic findings in a single, adult female Cuvier's beaked whale Ziphius cavirostris stranded in the Canary Islands. The study indicated that this whale died with a severe, systemic, herpesviral infection and clearly exhibited lesions different from those of the fat and gas embolic syndrome described in beaked whale mass strandings associated with sonar exposure. This is the first report of a cetacean alphaherpesvirus infection of the lymphoid system in a beaked whale.

High doses of dexamethasone induce increased beta-cell proliferation in pancreatic rat islets

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Leucine Supplementation Augments Insulin Secretion in Pancreatic Islets of Malnourished Mice

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Serum titres of anti-glutamic acid decarboxylase-65 and anti-IA-2 autoantibodies are associated with different immunoregulatory milieu in newly diagnosed type 1 diabetes patients

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Smoking status and tumor necrosis factor-alpha mediated systemic inflammation in COPD patients

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Functional and Structural Adaptations in the Pancreatic alpha-Cell and Changes in Glucagon Signaling During Protein Malnutrition

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Increased oxygen radical and high-dietary-carbohydrate pancreatic damage.

These data suggest that an improved understanding of the relationship between high dietary carbohydrate and the rate of lipid peroxidation may give some insight into possible treatment modalities for pancreatic damages and may shed light on molecular mechanisms underlying certain pathological processes. High dietary carbohydrate lesions are age related and induced alterations on ceruloplasmin, phospholipids, total proteins, copper and zinc serum levels. Significantly increased serum and pancreatic amylase, and lipoperoxide determinations were observed in 20 month old rats. Cu-Zn superoxide dismutase was decreased in these animals. Daily injection of Cu-Zn superoxide dismutase conjugated with polyethylene glycol (SOD-PEG) prevented the serum and pancreatic changes, indicating that superoxide radical is an important intermediate to high dietary carbohydrate lesion.

Immunohistochemical characterisation of probable intravascular haematopoiesis in the vasa rectae of the renal medulla in acute tubular necrosis

Immunohistochemistry was applied to identify the nature of the nucleated cells that accumulate in the vasa rectae of the corticomedullary junction in acute tubular necrosis. In all 6 cases studied, there were intravascular cells that reacted with monoclonal antibodies to erythroblast, macrophages, myeloid cells, T and B lymphocytes and rare megakaryocytes. The findings are consistent with the occurrence of intravascular haematopoiesis in the renal medulia in acute tubular necrosis.

Ebselen and cytokine-induced nitric oxide synthase expression in insulin-producing cells

Interleukin-1 (IL-1) may be a mediator of β-cell damage in insulin-dependent diabetes mellitus (IDDM). The IL-1 mechanism of action on insulin-producing cells probably includes activation of the transcription nuclear factor κB (NF-κB), increased transcription of the inducible form of nitric oxide synthase (iNOS) and the subsequent production of nitric oxide (NO). Reactive oxygen intermediates, particularly H2O2, have been proposed as second messengers for NF-κB activation. In the present study, we tested whether ebselen (2-phenyl-1,2-benzisoselenazol-3(2H)-one), a glutathione peroxidase mimicking compound, could counteract the effects of IL-1β, H2O2 and alloxan in rat pancreatic islets and in the rat insulinoma cell line RINm5F (RIN cells). Some of these experiments were also reproduced in human pancreatic islets. Ebselen (20 μM) prevented the increase in nitrite production by rat islets exposed to IL-1β for 6 hr and induced significant protection against the acute inhibitory effects of alloxan or H2O2 exposure, as judged by the preserved glucose oxidation rates. However, ebselen failed to prevent the increase in nitrite production and the decrease in glucose oxidation and insulin release by rat islets exposed to IL-1β for 24 hr. Ebselen prevented the increase in nitrite production by human islets exposed for 14 hr to a combination of cytokines (IL-1β, tumor necrosis factor-α and interferon-γ). In RIN cells, ebselen counteracted both the expression of iNOS mRNA and the increase in nitrite production induced by 6 hr exposure to IL-β but failed to block IL-1β-induced iNOS expression following 24 hr exposure to the cytokine. Moreover, ebselen did not prevent IL-1β-induced NF-κB activation. As a whole, these data indicate that ebselen partially counteracts cytokine-induced NOS activation in pancreatic β-cells, an effect not associated with inhibition of NF-κB activation.