Role of small GTPases in Trypanosoma cruzi invasion in MDCK cell lines

Trypanosoma cruzi can modulate a large number of host intracellular responses during its invasion. GTPases such as RhoA, Rac1 and Cdc42 are examples of molecules that could be activated at this moment and trigger changes in the pattern of F-actin cytoskeleton leading to the formation of structures like stress fibers, lamellipodium and fillopodium, respectively. Here we investigate the role of these GTPases in the cytoskeletal rearrangement of MDCK cell transfectants expressing variants of RhoA, Rac1 and Cdc42 during T. cruzi infection. The adhesion, internalization and the survival rate were determined. Rac1 mutants showed the higher adhesion and internalization indexes but the lower survival index after 48 h of infection. Confocal laser scanning microscopy showed changes in the pattern of F-actin distribution and reorganization at the site of trypomastigote invasion. These observations suggest that these GTPases act in the signaling mechanisms that affect the F-actin cytoskeleton during T. cruzi invasion.     

Organization, expression and polymorphism of the human persyn gene

Persyn is a recently identified member of the synuclein family with a distinct pattern of expression during pre- and postnatal development of the mouse peripheral and central nervous systems. As with other synucleins, persyn is believed to be involved in the pathogenesis of human neurodegenerative diseases. However, in contrast to other synucleins, high levels of persyn mRNA expression were also found in advanced breast carcinomas, suggesting an involvement of the encoded protein in breast tumour progression. Here we have used an antibody specific to human persyn to demonstrate that the level of this protein is increased in ageing cerebral cortex and in breast tumours. We cloned, characterized and sequenced the human persyn genomic locus and localized it to the long arm of chromosome 10 in the q23.2-q23.3 region. Sequence information was used to search for specific mutations in the protein coding regions of persyn mRNA and the persyn gene in breast tumours and tumour cell lines. No tumour-specific mutations were found, but two linked polymorphisms in the coding region were detected, both in mRNA and exons III and IV of the gene. These results suggest that development of breast tumours correlates with overexpression of the wild-type persyn protein. Detailed characterization of the human persyn locus is important for further studies of the involvement of persyn in neurodegeneration and malignancy.      

The impact of c-kit and ki-67 expression on patients prognosis in advanced ovarian serous carcinoma.

The transmembrane-tyrosine-kinase receptor, c-kit, is involved in cell differentiation and has been found to be expressed in normal human cell types and solid tumors. This study was designed to investigate the effects of c-kit expression on: 1) tumor proliferation and apoptosis, and 2) survival in patients with high-grade advanced stage ovarian serous carcinoma (OSC). We identified 118 patients with high-grade advanced stage OSC from our files. Clinical data, including demographics and overall survival, were collected. Immunohistochemical panel consisting of c-kit, ki-67, p53, and bcl-2 was performed. C-kit was categorized as positive if any cytoplasmic or membranous staining pattern was identified. Correlation between c-kit expression and the other markers was performed. Survival analysis was performed using COX proportional hazards regression and Kaplan-Meier test. Of 118 cases, 25 (21.2%) expressed c-kit. Of 93 c-kit-negative tumors, 87.1% had a high proliferation index. High p53 and bcl-2 expression was identified in 96 (81.4%) and 59 (50%) cases respectively. No significant statistical correlation was identified between c-kit and apoptosis markers. Tumors lacking c-kit expression showed a trend toward having high proliferation index, but this did not achieve statistical significance (p = 0.07). Of the seven variables included in the multivariate survival analysis, only c-kit (odds ratio, 2.12; 95% confidence interval, 08-4.17; p = 0.02) and ki-67 (odds ratio, 1.9; 95% confidence interval, 1.1-3.1; p = 0.03) showed an independent statistically significant impact on survival. High-grade advanced stage OSC lacking c-kit expression correlates with poor outcome. Interestingly, cases lacking c-kit expression also showed a trend to have high proliferation index.     

Prebiotics in infant milk formulas: new perspectives

In recent years it has become accepted that healthy human intestinal microflora may play an important part in priming the infants' systemic and mucosal immunity. Dietary modulation of the gut microbiota is a topical area of nutritional sciences and the main focus of many current functional foods such as non-digestible oligosaccharides (NDOs). Fructo-oligosaccharides (FOS) and trans-β-galacto-oligosaccharides (TOS) have been claimed to benefit the health of the colon by selectively stimulating the growth of bifidobacteria and lactobacilli (prebiotic effect). It could be of clinical interest to manipulate colonic flora because it is supposed that specific bacteria in the gut microbial microflora could promote potentially antiallergenic processes and play a key part in atopic disease prevention. Supporting this view is the finding that analysis of the composition of the intestinal bacterial populations showed different microbial patterns between healthy and allergic individuals. Assuming that non-digestible TOS and FOS can affect the intestinal ecosystem beneficially, the opportunity for gut flora manipulation arises in bottle-fed infants. New preterm and term infant milk formulas, supplemented with a mixture of TOS and FOS as prebiotic ingredients induced a significantly higher colonization of bifidobacteria and lactobacilli. In the future, selective manipulation of the intestinal microbiota might be an approach to novel prophylactic and therapeutic intervention strategies of atopy, by redirecting allergic Th-2 responses in favour of Th-1 responses.     

Intranasal delivery of interleukin-4 attenuates chronic cognitive deficits via beneficial microglial responses in experimental traumatic brain injury

Traumatic brain injury (TBI) is commonly followed by long-term cognitive deficits that severely impact the quality of life in survivors. Recent studies suggest that microglial/macrophage (Mi/MΦ) polarization could have multidimensional impacts on post-TBI neurological outcomes. Here, we report that repetitive intranasal delivery of interleukin-4 (IL-4) nanoparticles for 4 weeks after controlled cortical impact improved hippocampus-dependent spatial and non-spatial cognitive functions in adult C57BL6 mice, as assessed by a battery of neurobehavioral tests for up to 5 weeks after TBI. IL-4-elicited enhancement of cognitive functions was associated with improvements in the integrity of the hippocampus at the functional (e.g., long-term potentiation) and structural levels (CA3 neuronal loss, diffusion tensor imaging of white matter tracts, etc.). Mechanistically, IL-4 increased the expression of PPARγ and arginase-1 within Mi/MΦ, thereby driving microglia toward a global inflammation-resolving phenotype. Notably, IL-4 failed to shift microglial phenotype after TBI in Mi/MΦ-specific PPARγ knockout (mKO) mice, indicating an obligatory role for PPARγ in IL-4-induced Mi/MΦ polarization. Accordingly, post-TBI treatment with IL-4 failed to improve hippocampal integrity or cognitive functions in PPARγ mKO mice. These results demonstrate that administration of exogenous IL-4 nanoparticles stimulates PPARγ-dependent beneficial Mi/MΦ responses, and improves hippocampal function after TBI.     

The legendary superior strength of the Pfannenstiel incision: a myth?

OBJECTIVE: This study was undertaken to determine whether there is a difference in the frequency of fascial dehiscence between midline vertical lower abdominal and Pfannenstiel incisions among women undergoing obstetric and gynecologic operations. STUDY DESIGN: A case-control study of 48 cases of fascial dehiscence complicating 17, 995 major operations (8950 cesarean deliveries and 9405 gynecologic procedures) during a 6-year period at Wayne State University Hutzel Hospital, Detroit, was performed. Univariate analysis identified significant independent variables related to fascial dehiscence. Stepwise logistic regression analysis then identified those risk factors that were independently associated with fascial dehiscence. RESULTS: Among the 48 patients who underwent repair of fascial dehiscence after a major obstetric or gynecologic operation, 27 were from the obstetric service and 21 were from the benign and cancer gynecologic services. Wound dehiscence occurred in 10 vertical incisions and 17 Pfannenstiel incisions among the obstetric patients and in 12 vertical and 9 Pfannenstiel incisions among the gynecologic patients. The risk for dehiscence with vertical lower abdominal incisions was not increased with respect to that associated with Pfannenstiel incisions (P =.39, 2-tailed). This finding was true for all patients (odds ratio, 1.3; 95% confidence interval, 0.7-2.6), obstetric patients (odds ratio, 1.3; 95% confidence interval, 0.5-3.4), and gynecologic patients (odds ratio, 1.5; 95% confidence interval, 0.5-4.0). Forty-seven of the 48 case patients had documented wound infections, compared with 1 of the 144 control subjects (P <.0001, odds ratio, 37.8; 95% confidence interval, 14.8-96.8). CONCLUSION: Wound infection was the most important risk factor for fascial dehiscence among women who underwent major obstetric and gynecologic operations. Our results do not support the long-held belief that Pfannenstiel incisions are stronger than lower abdominal vertical incisions and reduce the risk for fascial dehiscence.     

Expression of cyclooxygenase-2 in advanced stage ovarian serous carcinoma: correlation with tumor cell proliferation, apoptosis, angiogenesis, and survival

OBJECTIVE: Cyclo-oxygenase-2 seems to be involved at various steps in the processes of tumor progression. The objective of this study was to examine the relationship between cyclo-oxygenase-2 expression and tumor proliferation, apoptosis and angiogenesis in patients with advanced stage high-grade ovarian carcinoma. STUDY DESIGN: Specimens from 118 patients with high-grade and advanced stage (III, IV) serous ovarian carcinoma were evaluated by immunohistochemistry for cyclo-oxygenase-2, Ki-67, vascular endothelial growth factor, and bcl-2 expression. Tumor microvessel density was assessed with CD34 immunostaining. We investigated the relationships between cyclo-oxygenase-2 expression and clinicopathologic characteristics, tumor angiogenesis (tumor microvessel density and vascular endothelial growth factor expression), and tumor proliferation and apoptosis. The effect of cyclooxygenase-2 expression on patient survival was determined. RESULTS: There was a significant positive correlation between cyclo-oxygenase-2 expression in tumor cells and markers of tumor proliferation and angiogenesis. In univariate survival analysis, high cyclo-oxygenase-2 and high Ki-67 expression showed a significant impact of on patient survival (P < .001). In multivariate regression analysis, only Ki-67 expression retained its significance as an independent poor prognostic factor (death hazard ratio, 2.0; 95% CI, 1.2-3.3; P < .001). CONCLUSION: Expression of cyclo-oxygenase-2 correlates with tumor proliferation and tumor angiogenesis but not with apoptotic markers (bcl-2 expression) in high-grade, advanced-stage serous ovarian carcinoma.     

ISOENZYME CHANGES OF LACTATE DEHYDROGENASE IN PSORIATIC ERYTHROCYTES

SUMMARY. The distribution of LDH-isoenzyme fractions in erythrocytes in psoriasis was investigated. The results indicate a shift of enzymatic activity towards the anodic isocomponents LD₂ and LD₁ and thus to enhanced energy production by oxidation in psoriatics as compared with normal controls. The authors claim that these findings support their previous reports describing metabolic deviation with enhanced glucose-degradation through the oxidative processes of the pentose (hexosemonophosphate) cycle.