Cryptococcus neoformans responds to mannitol by increasing capsule size in vitro and in vivo

The polysaccharide capsule of the fungus Cryptococcus neoformans is its main virulence factor. In this study, we determined the effects of mannitol and glucose on the capsule and exopolysaccharide production. Growth in mannitol significantly increased capsular volume compared with cultivation in glucose. However, cells grown in glucose concentrations higher than 62.5 mM produced more exopolysaccharide than cells grown in mannitol. The fibre lengths and glycosyl composition of capsular polysaccharide from yeast grown in mannitol was structurally different from that of yeast grown in glucose. Furthermore, mannitol treatment of mice infected intratracheally with C. neoformans resulted in fungal cells with significantly larger capsules and the mice had reduced fungal dissemination to the brain. Our results demonstrate the capacity of carbohydrate source and concentration to modify the expression of a major virulence factor of C. neoformans. These findings may impact the clinical management of cryptococcosis.     

Combination of diffusion tensor and functional magnetic resonance imaging during recovery from the vegetative state

Background  

The rate of recovery from the vegetative state (VS) is low. Currently, little is known of the mechanisms and cerebral changes that accompany those relatively rare cases of good recovery. Here, we combined functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) to study the evolution of one VS patient at one month post-ictus and again twelve months later when he had recovered consciousness.     

Cot/tpl2 (MAP3K8) Mediates Myeloperoxidase Activity and Hypernociception following Peripheral Inflammation

Cot/tpl2 (also known as MAP3K8) has emerged as a new and potentially interesting therapeutic anti-inflammatory target. Here, we report the first study of Cot/tpl2 involvement in acute peripheral inflammation in vivo. Six hours after an intraplantar injection of zymosan, Cot/tpl2^−/− mice showed a 47% reduction in myeloperoxidase activity, concomitant with a 46% lower neutrophil recruitment and a 40% decreased luminol-mediated bioluminescence imaging in vivo. Accordingly, Cot/tpl2 deficiency provoked a 25–30% reduction in luminol-mediated bioluminescence and neutrophil recruitment together with a 65% lower macrophage recruitment 4 h following zymosan-induced peritonitis. Significantly impaired levels of G-CSF and GM-CSF and of other cytokines such as TNFα, IL-1β, and IL-6, as well as some chemokines such as MCP-1, MIP-1β, and keratinocyte-derived chemokine, were detected during the acute zymosan-induced intraplantar inflammatory response in Cot/tpl2^−/− mice. Moreover, Cot/tpl2 deficiency dramatically decreased the production of the hypernociceptive ligand NGF at the inflammatory site during the course of inflammation. Most importantly, Cot/tpl2 deficiency significantly reduced zymosan-induced inflammatory hypernociception in mice, with a most pronounced effect of a 50% decrease compared with wild type (WT) at 24 h following intraplantar injection of zymosan. At this time, Cot/tpl2^−/− mice showed significantly reduced NGF, TNFα, and prostaglandin E₂ levels compared with WT littermates. In conclusion, our study demonstrates an important role of Cot/tpl2 in the NGF, G-CSF, and GM-CSF production and myeloperoxidase activity in the acute inflammatory response process and its implication in inflammatory hypernociception.     

Histological survey of symbionts and other conditions in razor clam Ensis arcuatus (Jeffreys, 1865) (Pharidae) of the coast of Galicia (NW Spain)

Symbionts and abnormal conditions of razor clam Ensis arcuatus were surveyed in three commercially important natural beds of Galician estuaries (NW Spain). Samples of 15-20 E. arcuatus were collected every 2 months from January 2003 until July 2004 and processed for histological examination. Prokaryote-like colonies, renal coccidians, gregarines, Trichodina sp. ciliates, haplosporidian-like plasmodia, turbelaria, trematode metacercariae, cestode-like larvae and basophilic inclusion bodies were observed in razor clam tissues without causing host damage. Bucephalid digenean sporocysts and germinoma were seen in some samples causing moderate or severe damage to the host depending on the intensity of infection and both could be a cause for concern if prevalence reached epizootic levels in Galician E. arcuatus populations. None of the parasites detected is OIE notifiable and, in general, the commercially exploited beds studied seem to be devoid of serious pathogens.     

Paralarvae of the jumbo squid,Dosidicus gigas

Abstract. The rhynchoteuthion stage of the jumbo squid, Dosidicus gigas, has morphological characteristics similar to the paralarvae of the purpleback squid, Sthenoteuthis oualaniensis, making it difficult to determine the locations, seasons, and conditions where spawning of jumbo squid occurs. In this study, 180 paralarvae of D. gigas were collected off the west coast of the Baja California peninsula and identified by sequencing a 369-bp fragment of the cytochrome oxidase I gene. Of these, 77 specimens, 0.8–6.0 mm in mantle length, were described. Indices based on morphometric ratios were used to determine whether the shapes of different body structures were reliable for identifying the paralarvae. For two ratios, the results appear to discriminate members of D. gigas from those of S. oualaniensis. Additionally, eye or intestinal photophores were not observed in any paralarvae of D. gigas. Morphological and morphometric information provided a valuable basis for the discrimination and identification of these two species.     

Morphologic, genetic, and biochemical characterization of Helicobacter magdeburgensis, a novel species isolated from the intestine of laboratory mice

Background: The presence of enterohepatic Helicobacter species (EHS) is commonly noted in mouse colonies. These infections often remain unrecognized but can cause severe health complications or more subtle host immune perturbations and therefore can confound the results of animal experiments. The aim of this study was to isolate and characterize a putative novel EHS that has previously been detected by PCR screening of specific‐pathogen‐free mice. Materials and Methods: Biochemical analysis of enzyme activities (API campy), morphologic investigation (Gram‐staining and electron microscopy) and genetic analyses (16SrRNA and 23SrRNA analyses, DNA fingerprinting, restriction fragment polymorphisms, and pulsed‐field gel electrophoresis) were used to characterize isolated EHS. Genomic DNA fragments were sequenced to develop a species‐specific PCR detection assay. Results: Scanning electron microscopy revealed the presence of spiral‐shaped EHS, which varied in length (2.5–6 μm) and contained single monopolar or single bipolar sheathed flagella. The bacteria were grown under anaerobic conditions, preferably on agar plates containing serum or blood. The 16SrRNA, genetic, and biochemical analyses indicated the identification of a novel EHS species, named Helicobacter magdeburgensis. We also examined the genome content using pulsed‐field gel electrophoresis. Based on the pattern produced by two restriction enzymes, BamIII and KspI, the genome size was determined to be about 1.7–1.8 Mbp. Conclusion: We isolated and characterized a novel EHS species, H. magdeburgensis, morphologically, biochemically, and genetically. These results are important for future studies on the prevalence and pathophysiologic relevance of such infections. Our PCR assay can be used to detect and discriminate H. magdeburgensis from other Helicobacter species.     

Trypanosoma cruzi-specific immune responses in subjects from endemic areas of Chagas disease of Argentina

Trypanosoma cruzi-specific immune responses were evaluated in a total of 88 subjects living in areas endemic of Chagas disease of Argentina by IFN-γ ELISPOT assays and immunoblotting. Positive T. cruzi antigen-induced IFN-γ responses were detected in 42% of subjects evaluated (15/26 positive by conventional serology and 22/62 seronegative subjects). Using immunoblotting, T. cruzi-specific IgG reactivity was detected in all seropositive subjects and in 11% (7/61) of subjects negative by conventional serology. Measurements of T cell responses and antibodies by immunoblotting, in conjunction with conventional serology, might enhance the capability of detection of exposure to T. cruzi in endemic areas.     

Prevalencia de alteraciones del metabolismo hidrocarbonado en una población infanto-juvenil con obesidad grave

IntroductionThere is currently a disproportionate increase in childhood and adolescent obesity worldwide, together with other disorders involving substantial cardiometabolic risk in adulthood, such as alterations in carbohydrate metabolism.ObjectiveTo establish the prevalence of prediabetes, defined as impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT) after an oral glucose tolerance test, and the prevalence of type 2 diabetes mellitus (DM-2) in a pediatric population with severe obesity. Additionally, we aimed to assess clinical metabolic differences between prediabetic obese patients and obese subjects without prediabetes.Material and methodsA cross-sectional study was carried out in children and adolescents with severe obesity (>97th percentile). The variables studied were age, sex, height, weight, body mass index, waist circumference, fasting plasma glucose and oral glucose tolerance test, insulinemia, insulin resistance assessed by the homeostasis model assessment (HOMA) index, glycated hemoglobin (HbA_1c), triglycerides, high-density lipoprotein cholesterol (HDL), and systolic and diastolic blood pressure.ResultsA total of 133 patients were included: 67 boys (50.4%) and 66 girls (49.6%), with a mean age of 12.17±3.27 years. Fourteen patients (10.52%) had prediabetes (10 IFG, 3 IGT, 1 IFG+IGT): 7 girls and 8 boys, with a mean age of 13.2±3.3 years. One patient had DM2 (0.75%). Patients with prediabetes had significantly higher concentrations of fasting glucose (98±10.76 vs 88.53±6.3 mg/d; p=0.001), insulinemia (35.38±14.22 vs 22.95±14.30 μU/ml; p=0.009) and HOMA index (8.10±3.24 vs 4.89±3.27; p=0.004) than patients without impaired carbohydrate metabolism. These patients also had higher values of HbA_1c, triglycerides, blood pressure and HDL concentrations, although differences were not statistically significant.ConclusionsThe prevalence of prediabetes (IFG/IGT) in children with severe obesity was high (10.52%). These patients should therefore be investigated to establish early diagnosis and appropriate treatment. Obese patients with prediabetes have significantly higher levels of insulin and insulin resistance than individuals without impaired carbohydrate metabolism.