Interaction of ascaridole,carvacrol, and caryophyllene oxide from essential oil of Chenopodium ambrosioides L. with mitochondria in Leishmania and other eukaryotes

The antileishmanial activity of the essential oil (EO) from Chenopodium ambrosioides L. has been demonstrated in vitro and in animal models, attributed to the major components of the EO. This study focused on the effects of the three major EO compounds carvacrol, caryophyllene oxide (Caryo), and the antileishmanial endoperoxide ascaridole (Asc) on mitochondrial functions in Leishmania tarentolae promastigotes (LtP). EO and Caryo were able to partially inhibit the leishmanial electron transport chain, whereas other components failed to demonstrate a direct immediate effect. Caryo demonstrated inhibition of complex III activity in LtP and in isolated complex III from other species. The formation of superoxide radicals was studied in Leishmania by electron spin resonance spectroscopy in the presence of iron chelators wherein selected compounds failed to trigger a significant immediate additional superoxide production in LtP. However, upon prolonged incubation of Leishmania with Asc and especially in the absence of iron chelators (allowing the activation of Asc), an increased superoxide radical production and significant impairment of mitochondrial coupling in Leishmania was observed. Prolonged incubation with all EO components resulted in thiol depletion. Taken together, the major components of EO mediate their leishmanicidal activity via different mitochondrial targets and time profiles. Further studies are required to elucidate possible synergistic effects of carvacrol and Asc and the influence of minor compounds.     

Dissociation of attention in learning and action: effects of lesions of the amygdala central nucleus, medial prefrontal cortex, and posterior parietal cortex

Many associative learning theories assert that the predictive accuracy of events affects the allocation of attention to them. More reliable predictors of future events are usually more likely to control action based on past learning, but less reliable predictors are often more likely to capture attention when new information is acquired. Previous studies showed that a circuit including the amygdala central nucleus (CEA) and the cholinergic substantia innominata/nucleus basalis magnocellularis (SI/nBM) is important for both sustained attention guiding action in a five-choice serial reaction time (5CSRT) task and for enhanced new learning about less predictive cues in a serial conditioning task. In this study, the authors found that lesions of the cholinergic afferents of the medial prefrontal cortex interfered with 5CSRT performance but not with surprise-induced enhancement of learning, whereas lesions of cholinergic afferents of posterior parietal cortex impaired the latter effects but did not affect 5CSRT performance. CEA lesions impaired performance in both tasks. These results are consistent with the view that CEA affects these distinct aspects of attention by influencing the activity of separate, specialized cortical regions via modulation of SI/nBM.     

Evaluation of Preoperative Serum Levels of CA 125 and Expression of p53 in Ovarian Neoplasms: A Prospective Clinicopathological Study in a Tertiary Care Hospital

Objectives

To assess the preoperative serum levels of CA 125 with its diagnostic role and to evaluate the p53 expression in patients of primary ovarian neoplasms. We also wished to judge their relationship with other parameters like clinical staging and histopathologic tumor type.

Materials and Methods

The present study was conducted on 86 patients during the study period of 2.5 years. Preoperative CA 125 levels were evaluated by an automated immunoassay analyzer. p53 expression was judged immunohistochemically with pre-diluted monoclonal antibody. An objective scoring was done depending on distinct nuclear immunopositivity.

Results

Median value of preoperative CA 125 levels was 32 U/mL in benign surface epithelial-stromal tumors (BSEST), 53 U/mL in borderline surface epithelial-stromal tumors (BOT), 346 U/mL in malignant surface epithelial-stromal tumors (MSEST) and 560 U/mL in serous adenocarcinomas (SAC). Most of ovarian tumors were in the FIGO stage I (64 cases, 74.4%), but higher stages (II, III, IV) were observed mostly in MSESTs. SACs displayed the maximum p53 expression. Considering the cut-off value of more than 35 U/mL in CA 125 levels, the sensitivity to diagnose MSESTs was 94.7%. Preoperative CA 125 levels strongly and positively correlated with FIGO staging and p53 expression. Similarly p53 expression strongly and positively correlated with FIGO staging and histopathological categories.

Conclusion

Higher values of preoperative CA 125 levels and higher expression p53 are associated with MSESTs and BOTs especially of serous type. They strongly correlate with each other and with tumor stage. But there is no serum CA 125 concentration that can clearly differentiate benign and malignant ovarian masses.     

Cell membrane-associated MT1-MMP-dependent activation of pro-MMP-2 in A375 melanoma cells.

Matrix metalloproteinases (MMPs), a family of zinc-dependent endopeptidases, can degrade extracellular matrix components under physiological conditions and during cancer invasion and metastasis. Among the MMPs, the 72 kDa type IV collagenase MMP-2 (gelatinase A) is activated in a membrane-associated manner by an activation complex composed of membrane type 1 matrix metalloproteinase (MT1-MMP), tissue inhibitor of matrixmetalloproteinase-2 (TIMP-2), and pro-MMP-2 in the presence of alphavbeta3 integrin receptor. The activation of pro-MMP-2 correlates with increased occurrence of metastases. Increased MMP-2 activity has been demonstrated in many human tumors. In the present communication, we studied cell surface-associated activation of MMP-2 (72 kDa collagenase type IV) in the moderately metastatic human melanoma cell line A375. RESULTS: Activation of purified 72 kDa collagenase type IV, pro-MMP-2 from cervical cancer tissue homogenate and from serum-free culture medium of HT1080 cells grown in presence of concanavalin A, by A375 cells, was shown by gelatin zymography. A375 cells activated only pro-MMP-2 from purified MMP-9/MMP-2 mixture indicating that the activation is specific for MMP-2. Activation of MMP-2 and purified collagenase type IV by A375 membrane fraction and membrane extract was also demonstrated by gelatin zymography. When A375 cells were first incubated with anti-MT1-MMP polyclonal antibody, activation of collagenase type IV was significantly decreased, indicating that membrane-associated MMP-2 activation is MT1-MMP-mediated. Immunocytochemistry showed MT1-MMP localization at focal adhesion sites. The presence of the components of activation complex-MT1-MMP and integrin alphavbeta3-were confirmed by Western blot, cell adhesion assay, and integrin subunit assay. CONCLUSION: Our experimental findings furnish another example of the unique membrane-associated MMP-2 activation mechanism in A375 melanoma cells and clearly indicate the role of MT1-MMP in MMP-2 activation. The information could help in developing new therapies designed to interfere with MMP activation and management of cancer and metastases.     

Mechanisms of nitric oxide interplay with Rho GTPase family members in modulation of actin membrane dynamics in pericytes and fibroblasts

Migration of pericytes such as hepatic stellate cells is fundamentally important for diverse biological and pathological processes including tumor invasion and fibrosis. In prototypical migratory cells such as fibroblasts, the small GTPases Rac1 and RhoA govern the assembly of lamellipodia and stress fibers, respectively, cytoskeletal structures that are integral to the cell migration process. The gaseous signaling molecule nitric oxide (NO) influences growth factor chemotactic responses, although this occurs primarily in cell-type-specific ways and through cell biological effects that are poorly characterized. In this study, we use complementary molecular and cell biological approaches to delineate important roles for Rac1, RhoA, and NO in migration of the human hepatic stellate cell line LX2 and primary rat hepatic stellate cells. Both platelet-derived growth factor (PDGF) and Rac1 overexpression drove migration through formation of actin-positive filopodia spikes in LX2 as compared to the formation of lamellipodia in fibroblasts. NO inhibited PDGF- and Rac1-driven migration in LX2 by abrogating filopodia formation and inhibited migration of fibroblasts by attenuating lamellipodial protrusions. Additionally, RhoA conferred resistance to NO inhibition of migration and restored chemotactic responses to PDGF in the absence of functional Rac1 in LX2. In conclusion, these studies identify novel crosstalk between small GTPases, cytoskeletal structures, and NO in pericyte-specific pathways, providing counterbalances in the chemotactic responses to growth factors.     

Extracorporeal membrane oxygenation with lepirudin anticoagulation for Wegener's granulomatosis with heparin-induced thrombocytopenia

Venovenous extracorporeal membrane oxygenation with lepirudin anticoagulation was successfully used for a complicated case of Wegener's granulomatosis and heparin-induced thrombocytopenia. Interestingly, a linear correlation was found between activated partial thromboplastin time and activated clotting time during lepirudin anticoagulation.     

Juvenile rhesus monkeys have more colonic granulomas than adults after primary infection with<Emphasis Type="Italic"> Schistosoma mansoni</Emphasis>

Adults and children have differences in their susceptibility to schistosomiasis. Whether this age-dependent innate susceptibility influences parasite-caused granulomogenesis is difficult to assess in humans. Therefore, we exposed juvenile and adult female rhesus monkeys to primary infection with Schistosoma mansoni. Hepatic and intestinal granuloma formation was observed in both pre-pubescent and adult monkeys. Two distinct stages of granulomas were discerned, the exudative and the productive stage. In the intestine, more granulomas were generated in the colon than in the ileum. In contrast to the adult animals, the juvenile rhesus monkeys had higher numbers of colonic granulomas, these higher numbers being predominantly of the more advanced productive stage. Juvenile animals had a statistically non-significant increased worm burden. These results suggest that juvenile rhesus monkeys have a significantly more intense and advanced colonic response towards entrapped S. mansoni eggs after primary schistosome infections and, thereby, are more susceptible to parasite infection.Research protocols involving non-human primates received ethical clearance by the Institutional Animal Care and Use Committee of the Biomedical Primate Research Centre (Rijswijk, The Netherlands), according to Dutch Law.     

Microalbuminuria: A novel biomarker of sepsis

Context:

Diffused endothelial dysfunction in sepsis leads to an increase in systemic capillary permeability, the renal component manifesting as microalbuminuria. The degree of microalbuminuria correlates with the severity of the acute insult, the quantification of which may serve to predict sepsis and mortality in critically ill patients.

Aims:

To evaluate whether the degree of microalbuminuria could differentiate patients with sepsis from those without and predict mortality in critically ill patients.

Settings and Design:

Prospective, non-interventional study in a 20-bed Intensive Care Unit (ICU) of a tertiary care hospital.

Methods and Materials:

After exclusions, between Jan-May 2007, 94 consecutive adult patients were found eligible. Albumin-creatinine ratio (ACR, mg/g) was measured in urine samples collected on ICU admission (ACR1) and at 24 hours (ACR2).

Results:

Patients were classified into two groups: those with sepsis, severe sepsis and septic shock (n = 30) and those without sepsis [patients without systemic inflammatory response syndrome (SIRS) and with SIRS due to noninfectious causes] (n = 64). In the sepsis group, median ACR1 [206.5 (IQR129.7-506.1)] was significantly higher compared to the non sepsis group [76.4 (IQR29-167.1)] (P = 0.0016, Mann Whitney). The receiver operating characteristics (ROC) curve analysis showed that at a cut off value 124 mg/g, ACR1 may be able to discriminate between patients with and without sepsis with a sensitivity of 80%, specificity of 64.1%, positive predictive value (PPV) of 51.1% and negative predictive value (NPV) of 87.3%. The median ACR2 [154 (IQR114.4-395.3)] was significantly higher (P = 0.004) in nonsurvivors (n = 13) as compared to survivors [50.8 (IQR 21.6-144.7)]. The ROC curve analysis revealed that ACR2 at a cut-off of 99.6 mg/g could predict ICU mortality with sensitivity of 85%, specificity of 68% with a NPV of 97% and PPV of 30%.

Conclusion:

Absence of significant microalbuminuria on ICU admission is unlikely to be associated with sepsis. At 24 hours, absence of elevated levels of microalbuminuria is strongly predictive of ICU survival, equivalent to the time-tested APACHE II scores.     

Maternal disease stage and child undernutrition in relation to mortality among children born to HIV-infected women in Tanzania

OBJECTIVE: To examine whether maternal HIV disease stage during pregnancy and child malnutrition are associated with child mortality. DESIGN: Prospective cohort study in Tanzania. METHODS: Indicators of disease stage were assessed for 939 HIV-infected women during pregnancy and at delivery, and children's anthropometric status was obtained at scheduled monthly clinic visits after delivery. Children were followed up for survival status until 24 months after birth. RESULTS: Advanced maternal HIV disease during pregnancy (CD4 count <350 vs. >or=350 cells/mm) was associated with increased risk of child mortality through 24 months of age (hazard ratio [HR] = 1.74, 95% confidence interval [CI]: 1.32 to 2.30). CD4 count <350 cells/mm was also associated with an increased risk of death among children who remained HIV-negative during follow-up (HR = 2.00, 95% CI: 1.36 to 2.94). Low maternal hemoglobin concentration and child undernutrition were related to an increased risk of mortality in this cohort of children. CONCLUSIONS: Low maternal CD4 cell count during pregnancy is related to increased risk of mortality in children born to HIV-infected women. Care and treatment for HIV disease, including highly active antiretroviral therapy to pregnant women, could improve child survival. Prevention and treatment of undernutrition in children remain critical interventions in settings with high HIV prevalence.