Effect of fire on a monodominant floating mat of Cyperus giganteus Vahl in a neotropical wetland

The rhizomatous Cyperus giganteus, abundant in the Pantanal wetland, can dominate extense floodable areas as monodominant communities. The Jacadigo lake has a large area of C. giganteus, where we performed an evaluation on community structure during two months in 2010, before it was hit by a wildfire which top-killed the vegetation, compared to ten months post-fire. We utilized 40 plots of 1m × 1m, along permanent trails, assessing two strata: the upper, near the inflorescence of adult plants, and the lower, close to the water level. Our results show that fire does not affect dominance of C. giganteus, as it maintained the same cover as before fire; species richness is not much altered either - 28 before fire and 34 thereafter. Fire changed the floristic composition, due to the annual variation of species and the ability of some plants to colonize gaps and to regrow after fire from underground organs and seeds. The stratification of the vegetation with characteristic species of upper and lower strata was similar after fire.

Development and application of efficient pathway enumeration algorithms for metabolic engineering applications

Metabolic Engineering (ME) aims to design microbial cell factories towards the production of valuable compounds. In this endeavor, one important task relates to the search for the most suitable heterologous pathway(s) to add to the selected host. Different algorithms have been developed in the past towards this goal, following distinct approaches spanning constraint-based modeling, graph-based methods and knowledge-based systems based on chemical rules. While some of these methods search for pathways optimizing specific objective functions, here the focus will be on methods that address the enumeration of pathways that are able to convert a set of source compounds into desired targets and their posterior evaluation according to different criteria. Two pathway enumeration algorithms based on (hyper)graph-based representations are selected as the most promising ones and are analyzed in more detail: the Solution Structure Generation and the Find Path algorithms. Their capabilities and limitations are evaluated when designing novel heterologous pathways, by applying these methods on three case studies of synthetic ME related to the production of non-native compounds in E. coli and S. cerevisiae: 1-butanol, curcumin and vanillin. Some targeted improvements are implemented, extending both methods to address limitations identified that impair their scalability, improving their ability to extract potential pathways over large-scale databases. In all case-studies, the algorithms were able to find already described pathways for the production of the target compounds, but also alternative pathways that can represent novel ME solutions after further evaluation.

Prevalence and predictors of nonadherence to hemodialysis

BACKGROUND

The prevalence of nonadherence to dialysis (NAD) presents a wide variation, depending on the parameters used and demographic regions studied. This study aimed to assess the prevalence and predictors of NAD of patients with chronic kidney disease undergoing hemodialysis (HD).

MATERIALS AND METHODS

This was a cross-sectional study with 255 adult patients receiving HD for >3 months. Skipping a session per month, shortening a session for at least 10 min, phosphorus >7.5 mg/dl, potassium >6.0 mmol/l and interdialytic weight gain (IDWG) >5.7% of body weight were indicative of NAD. The association of sociodemographic and clinical variables with NAD was assessed using logistic regression.

RESULTS

Mean age was 50 ± 13.1 years, 62.7% were male, 85.5% were of African descent and 62% were married. The prevalence rates of NAD were: 49% of shortening sessions, 18% of hyperkalemia, 12% of hyperphosphatemia, 9% of IDWG >5.7% of dry weight and 8% of skipping HD. Independent predictors of NAD were: age ≤50 years, not being married, living alone, living in Salvador, attending dialysis without a companion, ethnic African descent, Kt/V <1.3 and residual diuresis <100 ml/day.

CONCLUSION

NAD is frequent and distinct sociodemographic and clinical variables predict different parameters.

Relation between lipoprotein subfractions and TSH levels in the cardiovascular risk among women with subclinical hypothyroidism

OBJECTIVE

Subclinical hypothyroidism (SCH) is a common condition associated with increased cardiovascular risk. A standard treatment is yet to be established, as there is no consensus on the TSH cut-off values which should be used as indicators. Thus, the aim of this study was to assess cardiovascular risk in patients with SCH and to differentiate it according to TSH levels.

DESIGN

This was an observational study conducted in an academic medical centre.

PATIENTS

The study population consisted of 95 middle-aged women recently diagnosed with SCH and 65 euthyroid controls.

MEASUREMENTS

We measured anthropometric parameters, lipid cardiovascular risk markers and lipoprotein subclasses of HDL and LDL.

RESULTS

Patients with SCH exhibited a significant increase in triglycerides and atherogenic index of plasma and a significant reduction in HDL-cholesterol with respect to the control group after adjusted by age and BMI. A similar lipid profile was observed in both SCH groups. However, patients with TSH levels higher than 10 mIU/l showed a significant reduction in LDL particle size, which was associated with a higher prevalence of atherogenic pattern B.

CONCLUSIONS

Our findings indicate that cardiovascular risk is affected in patients with TSH levels over 10 mIU/l, who have a lipid profile characteristic of atherogenic dyslipidemia.

Effective immune rejection of advanced metastasized cancer

A cellular cancer therapy is described with unique efficiency even in late-stage disease. in situ activated tumor-immune T cells, induced in allogeneic, tumor-resistant, MHC identical but superantigen different donor mice (B10.D2) could transfer strong graft-versus-leukemia (GvL) effects accompanied by only mild graft-versus-host (GvH) reactivity. Systemic immune cell transfer into 5 Gy irradiated DBA/2 mice bearing up to 4 week established syngeneic tumors and macrometastases led to massive infiltration of tumor tissues by CD4 and CD8 donor T lymphocytes. Upon interaction of immune CD4 donor T cells with host antigen presenting cells in synergy with immune CD8 donor T cells attacking the tumor cells directly, primary tumors (1.5 cm diameter) were encapsulated and rejected from the skin and liver metastases eradicated. For the first time, such adoptive cellular immunotherapy (ADI) was followed in individual live animals by P-31-NMR spectroscopy of primary tumors. An approximately 25,000 fold excess of metastatic tumor cells could be rejected as revealed quantitatively by FACScan analysis of lacZ gene transfected tumor cells.

Changes in liver glycogen and lipid metabolism during transient graft-versus-host (GvH) and graft-versus-leukemia (GvL) reactivity

We investigated the influence of transient graft-versus-leukemia (GvL) and graft-versus-host reactivity (GvH) following allogeneic immune cell transfer on the glycogen and lipid metabolism in the liver of affected mice to better understand the underlying mechanism of these phenomena. As model we used a well established adoptive cellular immunotherapy (ADI) system. This involves transfer of in situ activated anti-tumor immune spleen lymphocytes (ISPL) from the tumor-resistant mouse strain B10.D2 (H-2(d), M1s(b)) into 5 Gy sublethally irradiated syngeneic ESb-MP lymphoma-bearing DBA/2 (H-2(d), M1s(a)) mice. Experiments were performed by transfer of ISPL from B10.D2 into DBA/2 tumor-bearing mice (GvL effect on liver metabolism) and into DBA/2 non-tumor-bearing mice (GvH effect on liver metabolism). Our results show that glycogen in hepatocytes decreased dramatically 5 days after ISPL transfer, which coincided with a high increase of large fat granules. 8 days after ISPL transfer, livers started to re-express glycogen and to decrease their lipid content. Normalization of both parameters was seen after day 30. These changes were qualitatively similar in both GvL and GvH. Measurement of activity of the liver marker enzymes, GOT and GPT, in the sera of animals subjected to GvL or GvH, showed peak values also at day 5, coinciding with the loss of glycogen. Quantitative differences were seen, however, in that much higher levels were reached in GvL than in GvH. Immune system recovery from irradiation damage and liver regeneration after immune cell mediated liver damage are likely explanations for the reversibility of the metabolic changes and for the lack of GVH disease and mortality in this new and effective cellular cancer immunotherapy model.

Activated endothelial cells induce apoptosis in lymphoma cells

We have previously shown that the arrest or regression of mouse liver metastases formed by lacZ-transduced ESbL T lymphoma cells (ESbL-lacZ) is associated with the stimulation of nitric oxide (NO) production by liver endothelial cells in sis. Here we studied in vitro the NO-mediated cytotoxicity against ESbL-lacZ target cells using well-characterized bovine endothelial cells (BEG) as effector cells. It was found that the co-culture of BEC with human TNF-alpha caused an increase of NO synthesis which could be completely blocked by the treatment with inducible NO synthase (iNOS) inhibitor N-G-monomethyl-L-arginine (NMMA). Incubation of activated BEC with metastatic lymphoma cells led to the death of the latter cells as evidenced by staining with propidium iodide and FAGS analysis. This cytotoxicity was considerably reduced after pretreatment of BEC with NMMA. Cytotoxic effects were also demonstrated after incubation of tumor cells with NO donor glycerol trinitrate (GTN). Non-activated BEC were not able to produce NO and showed a substantially lower level of cytotoxicity. The anti-tumor cytotoxicity exerted by activated BEC includes the stimulation of apoptosis in metastatic lymphoma cells which is mediated to a large extent by NO. These data reveal a novel role of endothelial cells in the elimination of metastatic cells through the induction of programmed cell death.

In situ downregulation of VLA-4 integrin cell surface expression during lymphoma growth and liver metastasis

The role of VLA-4 integrin in liver metastasis of lymphoma cells was investigated. ESbL-lacZ lymphoma cells in vitro exhibited high surface expression of VLA-4, adhered to CS-1 fibronectin and VCAM-1 and cell adhesion was inhibited by anti-VLA-4 MAb PS/2. When injected in vivo, however, PS/2 did not interfere with spontaneous liver metastasis and had no effect on survival. Ex vivo analysis of VLA-4 surface expression was facilitated by a new reisolation method for tumor and host cells derived from metastatic target organs. Freshly ex vivo isolated tumor cells from metastatic livers revealed VLA-4 surface downregulation as early as 3 days after tumor injection, which continued during the course of metastasis. VLA-4 downregulation in liver metastasis was also seen at the mRNA transcriptional level. Primary tumor cells showed similar VLA-4 downregulation suggesting that the in vivo phenotype was induced by the microenvironment at the primary tumor site. In support of this hypothesis, re-isolated tumor cells from metastatic livers recovered the high VLA-4 expression in host-depleted cell cultures. This study suggests that VLA-4 expression on tumor cells can be modulated in situ during tumor growth and metastasis formation.

Hypertrophic pulmonary osteoarthropathy with positive antinuclear antibodies: case report

A male Afro-descendant patient, 57 years old, complaining of polyarticular involvement and weight loss for 18 months, with a load of 13.5 pack years of smoking. On physical examination there was pain on palpation of the right knee and right leg, with signs of inflammation on the knee. We also observed digital clubbing in all fingers. Antinuclear antibodies (ANA) and anti-Sm antibodies were positive. X-rays of the legs and arm showed cortical thickening of long bones. The computed tomography demonstrated a large mass located in the middle lobe of the right lung. The anatomopathological study revealed a bronchial adenocarcinoma. The history of polyarticular involvement associated with positive anti-Sm and ANA antibodies could lead to an erroneous diagnosis of systemic lupus erythematosus. Considering the bad consequences of delayed diagnosis in this patient, the medical team should be alerted for suspecting and look for a lung cancer under these circumstances.

Is cerebellar volume related to bipolar disorder?

BACKGROUND

Recent data suggest that cerebellum influences emotion modulation in humans. The findings of cerebellar abnormalities in bipolar disorder (BD) are especially intriguing given the link between the cerebellum emotional and behavioral regulation. The purpose of this study was to evaluate cerebellar volume in patients with euthymic BD type I compared to controls. Moreover, we investigated the possible relationship between cerebellar volume and suicidal behavior.

METHODS

Forty-patients with euthymic BD type I, 20 with and 20 without history of suicide attempt, and 22 healthy controls underwent an MRI scan. The participants were interviewed using the Structured Clinical Interview with the DSM-IV axis I (SCID-I), the Hamilton Depression Rating Scale (HDRS), the Young Mania Rating Scale (YMRS) and the Barratt Impulsiveness Scale (BIS-11).

RESULTS

Groups were age, gender and years of schooling-matched. The left cerebellum (p=0.02), right cerebellum (p=0.02) and vermis (p<0.01) were significantly smaller in the BD group; however, there were no volumetric differences between the BD subjects with and without suicidal attempt. There was no correlation between cerebellar measurements and clinical variables.

LIMITATIONS

The main strength is that our sample consisted of patients with euthymic BD type I without any comorbidities, however, these results cannot establish causality as the cross-sectional nature of the study.

CONCLUSIONS

Our findings suggest that the reduction in cerebellar volumes observed in BD type I might be a trait-related characteristic of this disorder. Additional studies with larger samples and subtypes of this heterogeneous disorder are warranted to determine the possible specificity of this cerebellar finding.