Volunteers living in an area where schistosomiasis mansoni is endemic were subjected to ultrasound examination and classified into groups according to the levels of fibrosis diagnosed, namely, absence of indications of fibrosis (group 0), incipient fibrosis (group 1), and moderate/severe fibrosis (group 2). Peripheral blood mononuclear cells (PBMC) collected from the volunteers were stimulated with soluble antigens from adult schistosomes or from schistosome eggs, and the production of the cytokines gamma interferon, tumor necrosis factor alpha, transforming growth factor ␤ (TGF-␤), interleukin-4 (IL-4), IL-10, and IL-13 was determined. Potential associations of the level of fibrosis with age, sex, intensity of infection, and cytokine production were investigated between the three groups. Univariate analysis identified associations of age (>50), gender (male), and absence of eggs/g of feces with moderate/severe fibrosis and an association of intensity of infection (>100 eggs) with incipient fibrosis. When cytokine production in PBMC cultures stimulated by soluble egg antigens was categorized as low or high, significant differences in the distribution of IL-13 levels were established between groups 0 and 2. No significant differences were detected between the groups in the cytokines produced by PBMC cultures stimulated with soluble antigens from adult schistosomes. When all variables were tested in multivariate analyses, only IL-13 was strongly associated with fibrosis (odds ratio ‫؍‬ 5.8; 95% confidence interval [CI] ‫؍‬ 1

BackgroundDuring the pre-patent stage of infection, juvenile Schistosoma blood flukes co-opt signals from the adaptive immune system to facilitate parasite development, but the types of responses that are induced at this early stage of infection, and the parasite antigens they target, have not been characterized.ResultsThrough analysis of experimental pre-patent infections, we show that the S. mansoni cysteine protease SmCB1 is rapidly targeted by an antigen-specific IgE response. The induction of this response is independent of schistosome eggs as infection with male or female worms alone also induced SmCB1-specific IgE. We also show that the SmCB1-specific IgE response is dependent on cognate CD4+ T cell help and IL-4, suggesting that pre-patent Th2 responses provide T cell help for the SmCB1-specific IgE response. Finally, exposed human subjects also produced IgE against SmCB1.ConclusionsOur data demonstrate that, like eggs, schistosome worms also induce functional type 2 responses and that a parasite cysteine protease is an inducer of type 2 responses during the early stages of schistosome infection.

To evaluate the effectiveness of somatostatin versus combined cimetidine and pirenzepine in the treatment of upper gastrointestinal (GI) bleeding of peptic origin, a multicentre controlled, prospective, randomized and double blind trial has been undertaken in 60 subjects. Strict selection criteria were followed. All subjects were diagnosed by endoscopy during the first 18 h after admission. Endoscopic stigmata of recent haemorrhage were also evaluated. Sixty-five per cent of the subjects presented with severe upper GI bleeding (blood pressure less than or equal to 100 mmHg, pulse rate greater than or equal to 110, haematocrit less than or equal to 30 per cent), and in 71.6 per cent stigmata were found. Thirty patients (Group 1) received a somatostatin infusion (250 micrograms/h continuously during 120 h) and 30 patients (Group 2) received cimetidine (200 mg IV every 4 h for 5 days) and pirenzepine (10 mg IV every 8 h for 5 days). Both groups were homogeneous for sex, age, backgrounds, bleeding source, grade of bleeding (moderate or severe) and presence or not of stigmata. Bleeding stopped in 27 subjects of Group 1 (90 per cent and in 20 subjects of Group 2 (66.67 per cent) (P less than 0.05, chi 2 test). The time until the bleeding stopped was significantly shorter in patients of group 1 (3.44 +/- 0.53 h) than in patients of group 2 (8.12 +/- 1.94 h) (P less than 0.05, Mann-Whitney U test). The number of blood units required for Group 1 (2.26 +/- 0.35) was significantly lower than the one required for Group 2 (3.90 +/- 0.51) (P less than 0.005, Wilcoxon test). Significant differences were not observed between the two groups regarding cross-over subjects, re-bleeding, surgery (P = 0.0635, Fisher's exact test) and hospital stay. The mortality of the trial was 5 per cent. There was no toxicity during somatostatin, cimetidine or pirenzepine infusion. In conclusion, somatostatin was more effective than cimetidine plus pirenzepine in the control of severe upper GI bleeding of peptic origin, with a lower interval time to stop bleeding and reduced transfusion requirements.

Observations were made on 100 female Aedes fluviatilis (Lutz) maintained individually from the first blood meal onwards and allowed one blood meal during each oviposition cycle, 5% dextrose solution been supplied throughout life. The average length of live was 49.9 ± 17.8 days; the logarithm of the mortality rate increased proportionately to physiological age. The insects took an average of 7.3 ± 3.2 blood meals and produced a mean of 7.9 ± 3.7 clutches of eggs. There was a progressive decrease, proportional to advancing physiological age, in the mean numbers of eggs laid in successive oviposition cycles, in the intervals between blood feeding oviposition, and in the numbers of larvae that hatched. Delayed oviposition, transient sterility and a total loss of fertility were also recorded.
De 100 fêmeas de Aedese fluviatilis (Lutz, 1904) individualmente observadas foram obtidos 45.475 ovos em um total de 790 posturas. As médias de desovas produzidas e de repastos sangüíneos ingeridos por fêmea, foram respectivamente 7,9 ± 3,7 e 7,3 ± 3,2 e a longevidade média foi de 49,9 ± 17,8 dias. Em análise de regressão linear, foi observado um progressivo decréscimo das médias de ovos por postura, larvas eclodidas e número de dias entre repasto sangüíneo e postura, proporcional ao aumento da idade fisiológica. Foram ainda observadas ocorrências de ingestão de sangue durante o desenvolvimento dos ovos, recusa de alimentação sangüínea entre desovas sucessivas, retenção espontânea de ovos por períodos apreciáveis, esterilidade transitória e esgotamento de fecundidade

We investigated the cytokine profile of peripheral mononuclear cells from chronic osteomyelitis (OST) patients following in vitro stimulation with staphylococcal enterotoxin A (SEA). We demonstrate that stimulation with SEA induced prominent lymphocyte proliferation and high levels of tumour necrosis factor (TNF)-α, interleukin (IL)-4 and IL-10 secretion in both OST and non-infected individuals (NI). Even though stimulation with SEA had no impact on IL-6 production in either patient group, the baseline level of IL-6 production by cells from OST patients was always significantly less than that produced by cells from NI. After classifying the osteomyelitic episodes based on the time after the last reactivation event as "early" (1-4 months) or "late" osteomyelitis (5-12 months), we found that increased levels of TNF-α and IL-4 in combination with decreased levels of IL-6 were observed in the early episodes. By contrast, increased levels of IL-10, IL-2 and IL-6 were hallmarks of late episodes. Our data demonstrate that early osteomyelitic episodes are accompanied by an increased frequency of "high producers" of TNF-α and IL-4, whereas late events are characterised by increased frequencies of "high producers" of IL-10, IL-6 and IL-2. These findings demonstrate the distinct cytokine profiles in chronic osteomyelitis, with a distinct regulation of IL-6production during early and late episodes.

Reducing insulin-like growth factor I receptor (IGF-IR) levels or administration of IGF-I show beneficial effects in the brain. We now provide evidence to help resolve this paradox. The unliganded IGF-IR inhibits glucose uptake by astrocytes while its stimulation with IGF-I, in concert with insulin activation of the insulin receptor, produces the opposite effect. In vivo imaging showed that shRNA interference of brain IGF-IR increased glucose uptake by astrocytes while pharmacological blockade of IGF-IR reduced it. Brain 18 FGlucose-PET of IGF-IR shRNA injected mice confirmed an inhibitory role of unliganded IGF-IR on glucose uptake, whereas glucose-dependent recovery of neuronal activity in brain slices was blunted by pharmacological blockade of IGF-IR. Mechanistically, we found that the unliganded IGF-IR retains glucose transporter 1 (GLUT1), the main glucose transporter in astrocytes, inside the cell while IGF-I, in cooperation with insulin, synergistically stimulates MAPK/PKD to promote association of IGF-IR with GLUT 1 via Rac1/GIPC1 and increases GLUT1 availability at the cell membrane. These findings identify IGF-I and its receptor as antagonistic modulators of brain glucose uptake.

Cannabis is the most widely used illicit drug worldwide. Its principal psychoactive component, ∆9-tetrahydrocannabinol (THC), acts as a partial agonist of the main cannabinoid receptor in the brain, the cannabinoid type-1 receptor (CB1R), being the main responsible for the central effects of THC including memory impairment. CB1Rs may form heterodimers with the serotonin 5-HT2A receptor (5-HT2AR) which were found responsible for the memory impairment produced by acute high dose of THC in mice. In this study we investigated whether a repeated low dose of THC (1 mg/kg), with no acute consequence on memory performance, could eventually have deleterious cognitive effects. We found that such a low dose of THC impairs novel object-recognition memory and fear conditioning memory after repeated treatment (7 days). This deficit was also detected 24 h after the last THC administration. At that time, a general enhancement of c-Fos expression was observed in several brain regions of THC-exposed animals. In addition, THC-treated mice showed a decreased spine density at CA1 pyramidal neurons and reduced long-term potentiation at Schaffer collateral-CA1 synapses. Interestingly, an up-regulation in the expression of CB1R/5-HT2AR heterodimers was observed in the hippocampus of THC-exposed mice and a pre-treatment with the 5-HT2AR antagonist MDL 100,907 (0.01 mg/kg) prevented enhanced heterodimerization and the THC-associated memory impairment. Together, these results reveal the significance of serotonergic signalling through 5-HT2ARs in the memory-impairing effects of repeated low doses of THC.

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