Inhibition of phospholipase A(2) in rat brain decreases the levels of total Tau protein

The microtubule-associated protein Tau promotes the assembly and stability of microtubules in neuronal cells. Six Tau isoforms are expressed in adult human brain. All six isoforms become abnormally hyperphosphorylated and form neurofibrillary tangles in Alzheimer disease (AD) brains. In AD, reduced activity of phospholipase A(2) (PLA(2)), specifically of calcium-dependent cytosolic PLA(2) (cPLA(2)) and calcium-independent intracellular PLA(2) (iPLA(2)), was reported in the cerebral cortex and hippocampus, which positively correlated with the density of neurofibrillary tangles. We previously demonstrated that treatment of cultured neurons with a dual cPLA(2) and iPLA(2) inhibitor, methyl arachidonyl fluorophosphonate (MAFP), decreased total Tau levels and increased Tau phosphorylation at Ser(214) site. The aim of this study was to conduct a preliminary investigation into the effects of in vivo infusion of MAFP into rat brain on PLA(2) activity and total Tau levels in the postmortem frontal cortex and dorsal hippocampus. PLA(2) activity was measured by radioenzymatic assay and Tau levels were determined by Western blotting using the anti-Tau 6 isoforms antibody. MAFP significantly inhibited PLA(2) activity in the frontal cortex and hippocampus. The reactivity to the antibody revealed three Tau protein bands with apparent molecular weight of close to 40, 43 and 46 kDa in both brain areas. MAFP decreased the 46 kDa band intensity in the frontal cortex, and the 43 and 46 kDa band intensities in the hippocampus. The results indicate that in vivo PLA(2) inhibition in rat brain decreases the levels of total (nonphosphorylated plus phosphorylated) Tau protein and corroborate our previous in vitro findings.

Pleural fluid: Are temperature and storage time critical preanalytical error factors in biochemical analyses?

Background: Biochemical analysis of fluid is the primary laboratory approach hi pleural effusion diagnosis. Standardization of the steps between collection and laboratorial analyses are fundamental to maintain the quality of the results. We evaluated the influence of temperature and storage time on sample stability. Methods: Pleural fluid from 30 patients was submitted to analyses of proteins, albumin, lactic dehydrogenase (LDH), cholesterol, triglycerides, and glucose. Aliquots were stored at 21 degrees, 4 degrees, and-20 degrees C, and concentrations were determined after 1, 2, 3, 4, 7, and 14 days. LDH isoenzymes were quantified in 7 random samples. Results: Due to the instability of isoenzymes 4 and 5, a decrease in LDH was observed in the first 24 h in samples maintained at -20 degrees C and after 2 days when maintained at 4 degrees C. Aside from glucose, all parameters were stable for up to at least day 4 when stored at room temperature or 4 degrees C. Conclusions: Temperature and storage time are potential preanalytical errors in pleural fluid analyses, mainly if we consider the instability of glucose and LDH. The ideal procedure is to execute all the tests immediately after collection. However, most of the tests can be done in refrigerated sample;, excepting LDH analysis. (C) 2010 Elsevier B.V. All rights reserved.

Pleural fluid cytokines correlate with tissue inflammatory expression in tuberculosis

SETTING: A tertiary care research centre in Sao Paolo, Brazil. OBJECTIVE: To quantify interleukin (IL) 8, tumour necrosis factor alpha (TNF-alpha), vascular endothelial growth factor (VEGF) and transforming growth factor beta(1), (TGF-beta(1))in pleural fluid from tuberculous patients, correlating its values with the histopathological patterns in pleural biopsies. DESIGN: Cytokines were quantified in patients with transudatcs secondary to congestive heart failure (n = 8) and exudates secondary to tuberculosis (TB; n = 39). In parietal pleural biopsies from TB patients, the histological patterns of the inflammatory response were quantified by morphometric analysis (stereological point-counting method). RESULTS: IL-8, TNF-alpha, VEGF and TGF-beta(1) levels were higher in TB than in transudates. A positive correlation existed between components of the fibrinoid exudative phase with pleural fluid IL-8 (R = 0.52, P = 0.004) and VEGF (R = 0.42, P = 0.0021) levels. A negative correlation existed between pleural fluid IL-8 (R = -0.37, P = 0.048) and VEGF (R = -0.44, P = 0.0015) levels with tissue components of fibroproliferation. CONCLUSION: The high pleural levels of TNF-a, IL-8, VEGF and TGF-beta(1) suggest the involvement of these cytokines in the TB immunological response. The positive correlation between pleural fluid IL-8 and VEGF with the components of the acute exudative phase and the negative correlation between these cytokines with the fibroproliferative components suggest a temporary inflammatory response in the pleural space.

Cytokine Profile in Pleural Fluid and Serum After Lung Transplantation

Background. Lung transplantation is the procedure of choice in several end-stage lung diseases. Despite improvements in surgical techniques and immunosuppression, early postoperative complications occur frequently. Objective. To evaluate the pleural inflammatory response after surgery. Patients and Methods. Twenty patients aged 18 to 63 years underwent unilateral or bilateral lung transplantation between August 2006 and March 2008. Proinflammatory cytokines interleukin (IL)-1 beta, IL-6, and IL-8 and vascular endothelial growth factor in pleural fluid and serum were analyzed. For cytokine evaluation, 20-mL samples of pleural fluid and blood (right, left, or both chest cavities) were obtained at 6 hours after surgery and daily until removal of the chest tube or for a maximum of 10 days. Data were analyzed using analysis of variance followed by the Holm-Sidak test. Results. All effusions were exudates according to Light`s criteria. Pleural fluid cytokine concentrations were highest at 6 hours after surgery. Serum concentrations were lower than those in pleural fluid, and IL-1 beta, IL-6, and IL-8 were undetectable at all time points. Conclusions. There is a peak concentration of inflammatory cytokines in the first 6 hours after transplantation, probably reflecting the effects of surgical manipulation. The decrease observed from postoperative day 1 and thereafter suggests the action of the immunosuppression agents and a temporal reduction in pleural inflammation.

Cerebrospinal fluid levels of chemokines in HIV infected patients with and without opportunistic infection of the central nervous system

Chemokines are chemoattractant cytokines involved in the immune response of a wide variety of diseases. There are few studies assessing their role in opportunistic infections in HIV-infected patients. In this study, we measured CC and CXC chemokines in cerebrospinal fluid (CSF) samples obtained from 40 HIV-infected patients with or without opportunistic infections of the central nervous system (CNS). CSF samples were also analyzed for quantification of total protein, cell count and HIV-1 RNA. HIV+ patients with cryptococcal meningitis had higher levels of CCL2, CCL3, CCL5, CXCL9 and CXCL10 when compared to patients without opportunistic neurological infections. Furthermore, HIV+ patients with associated cryptococcal meningitis had higher levels of CCL3, CXCL9 and CXCL10 when compared to HIV+ patients with associated toxoplasmic encephalitis. CCL3 and CXCL9 levels were positively correlated with CSF HIV-1 RNA levels, CSF protein concentration, and CSF cell count. CXCL10 level was correlated with the CSF viral load and the CSF cell count and CCL5 level was correlated with the CSF cell count. In conclusion, the profile of chemokines in CSF of HIV patients may differ according to the modality of the presented opportunistic infection and according to other biological markers, such as viral load in CSF. These differences are probably related to different patterns of neuroinflammatory responses displayed by patients with different opportunistic neurological infections. (C) 2009 Elsevier B.V. All rights reserved.

Monoclonal anti-vascular endothelial growth factor antibody reduces fluid volume in an experimental model of inflammatory pleural effusion

Background and objective: Vascular endothelial growth factor (VEGF) is known to increase vascular permeability and promote angiogenesis. It is expressed in most types of pleural effusions. However, the exact role of VEGF in the development of pleural effusions has yet to be determined. The anti-VEGF mAb, bevacizumab, has been used in the treatment of cancer to reduce local angiogenesis and tumour progression. This study describes the acute effects of VEGF blockade on the expression of inflammatory cytokines and pleural fluid accumulation. Methods: One hundred and twelve New Zealand rabbits received intrapleural injections of either talc or silver nitrate. In each group, half the animals received an intravenous injection of bevacizumab, 30 min before the intrapleural agent was administered. Five animals from each subgroup were sacrificed 1, 2, 3, 4 or 7 days after the procedure. Twelve rabbits were used to evaluate vascular permeability using Evans`s blue dye. Pleural fluid volume and cytokines were quantified. Results: Animals pretreated with anti-VEGF antibody showed significant reductions in pleural fluid volumes after talc or silver nitrate injection. IL-8 levels, vascular permeability and macroscopic pleural adhesion scores were also reduced in the groups that received bevacizumab. Conclusions: This study showed that bevacizumab interferes in the acute phase of pleural inflammation induced by silver nitrate or talc, reinforcing the role of VEGF as a key mediator in the production of pleural effusions. The results also suggest that bevacizumab should probably be avoided in patients requiring pleurodesis.

Influence of ventilatory settings on static and functional haemodynamic parameters during experimental hypovolaemia

Background and objective The influence of ventilatory settings on static and functional haemodynamic parameters during mechanical ventilation is not completely known. The purpose of this study was to evaluate the effect of positive end-expiratory pressure, tidal volume and inspiratory to expiratory time ratio variations on haemodynamic parameters during haemorrhage and after transfusion of shed blood. Methods Ten anaesthetized pigs were instrumented and mechanically ventilated with a tidal volume of 8 ml kg(-1), a positive end-expiratory pressure of 5 cmH(2)O and an inspiratory to expiratory ratio of 1 : 2. Then, they were submitted in a random order to different ventilatory settings (tidal volume 16 ml kg(-1), positive end-expiratory pressure 15 cmH(2)O or inspiratory to expiratory time ratio 2: 1). Functional and static haemodynamic parameters (central venous pressure, pulmonary artery occlusion pressure, right ventricular end-diastolic volume and pulse pressure variation) were evaluated at baseline, during hypovolaemia (withdrawal of 20% of estimated blood volume) and after an infusion of withdrawn blood (posttransfusion). Results During baseline, a positive end-expiratory pressure of 15cmH(2)O significantly increased pulmonary artery occlusion pressure from 14.6 +/- 1.6 mmHg to 17.4 +/- 1.7 mmHg (P<0.001) and pulse pressure variation from 15.8 +/- 8.5% to 25.3 +/- 9.5% (P<0.001). High tidal volume increased pulse pressure variation from 15.8 8.5% to 31.6 +/- 10.4% (P<0.001), and an inspiratory to expiratory time ratio of 2: 1 significantly increased only central venous pressure. During hypovolaemia, high positive end-expiratory pressure influenced all studied variables, and high tidal volume strongly increased pulse pressure variation (40.5 +/- 12.4% pre vs. 84.2 +/- 19.1 % post, P<0.001). The inversion of the inspiratory to expiratory time ratio only slightly increased filling pressures during hypovolaemia, without without affecting pulse pressure variation or right ventricle end-diastolic volume. Conclusion We concluded that pulse pressure variation measurement is influenced by cyclic variations in intrathoracic pressure, such as those caused by augmentations in tidal volume. The increase in mean airway pressure caused by positive end-expiratory pressure affects cardiac filling pressures and also pulse pressure variation, although to a lesser extent. Inversion of the inspiratory to expiratory time ratio does not induce significant changes in static and functional haemodynamic parameters. Eur J Anaesthesiol 26:66-72 (c) 2009 European Society of Anaesthesiology.

EFFECT OF FLUID AND FOOD INTAKE ON THE BODY COMPOSITION EVALUATION OF ELDERLY PERSONS

Background: Several studies have shown that liquid and food intake interfere with the evaluation of body composition in adults. However, since there are no reports about this interference in the elderly population, the need to fast for this evaluation may be dispensable. Objectives: The objective of the present study was to assess the influence of liquid and solid food on the measurement of body composition by bioelectrical impedance analysis (BIA) and by dual energy X-ray absorptiometry (DXA). Design: Forty-one male volunteers aged 62 to 87 years participated in the study. The subjects were submitted to evaluation of body composition by DXA and BIA under fasting conditions and 1 hour after the ingestion of breakfast (500 ml of orange juice and one 50 g bread roll with butter). Results: There was no significant difference in the variables fat-free mass (FFM) or fat mass (FM) between the fasting condition and the evaluation performed 1 hour after the meal as measured by BIA or DXA. There was also no significant difference when the same variables were compared between methods. Conclusion: In the present study, the ingestion of 500 ml orange juice and of one bread roll with butter by elderly subjects did not affect the results of the parameters of body composition determined by BIA or DXA. Thus, these exams could be performed without the rigor of fasting, often poorly tolerated by the elderly.

Bronchial responsiveness during esophageal acid infusion

Among the possible mechanisms explaining the worsening of asthma due to gastroesophageal reflux disease (GERD) is the increase in bronchial hyperresponsiveness. The effects of GERD on bronchial hyperresponsiveness in patients with bronchial asthma have yet to be studied in significant detail. The aim of this study was to determine the effects of esophageal acid perfusion on bronchial responsiveness to bradykinin in patients with both asthma and GERD. In 20 patients with asthma and GERD disease, esophageal pH was monitored with a pH meter and bronchial responsiveness was evaluated by aerosol inhalation of bradykinin during esophageal acid perfusion and, 24 h earlier or later the patients were submitted to another bronchial provocation test without acid infusion. No significant changes were observed in FEV1, FEF25-75%, FVC, or PEF during acid perfusion. The response to the bronchial provocation test did not differ between the control day and the day of acid infusion (p = 0.61). The concentration provoking a 20% fall in FEV1 (geometric mean +/- geometric SD) was 1.09 +/- 5.84 on the day of acid infusion and 0.98 +/- 5.52 on the control day. There is no evidence that acid infusion changes bronchial responsiveness to bradykinin. These findings strongly question the significance of acid infusion as a model to study the pathogenesis of GERD-induced asthma.

TNF-alpha Infusion Impairs Corpora Cavernosa Reactivity

Introduction. Erectile dysfunction (ED), as well as cardiovascular diseases (CVDs), is associated with endothelial dysfunction and increased levels of proinflammatory cytokines, such as tumor necrosis factor-alpha (TNF-alpha). Aim. We hypothesized that increased TNF-alpha levels impair cavernosal function. Methods. In vitro organ bath studies were used to measure cavernosal reactivity in mice infused with vehicle or TNF-alpha-(220 ng/kg/min) for 14 days. Gene expression of nitric oxide synthase isoforms was evaluated by real-time polymerase chain reaction. Results. Cavernosal strips from the TNF-alpha-infused mice displayed decreased nonadrenergic-noncholinergic (NANC)-induced relaxation (59.4 +/- 6.2 vs. control: 76.2 +/- 4.7; 16 Hz) compared with the control animals. These responses were associated with decreased gene expression of eNOS and nNOS (P < 0.05). Sympathetic-mediated, as well as phenylephrine (PE)-induced, contractile responses (PE-induced contraction; 1.32 +/- 0.06 vs. control: 0.9 +/- 0.09, mN) were increased in cavernosal strips from TNF-alpha-infused mice. Additionally, infusion of TNF-alpha increased cavernosal responses to endothelin-1 and endothelin receptor A subtype (ET(A)) receptor expression (P < 0.05) and slightly decreased tumor necrosis factor-alpha receptor 1 (TNFRI) expression (P=0.063). Conclusion. Corpora cavernosa from TNF-alpha-infused mice display increased contractile responses and decreased NANC nerve-mediated relaxation associated with decreased eNOS and nNOS gene expression. There changes may trigger ED and indicate that TNF-alpha plays a detrimental role in erectile function. Blockade of TNF-alpha actions may represent an alternative therapeutic approach for ED, especially in pathologic conditions associated with increased levels of this cytokine. Carneiro FS, Zemse S, Giachini FRC, Carneiro ZN, Lima W, Clinton Webb R, and Tostes RC. TNF-alpha infusion impairs corpora cavernosa reactivity. J Sex Med 2009;6(suppl 3):311-319.

Supplemented tissue culture medium 199 is a better medium for in vitro maturation of oocytes from women with polycystic ovary syndrome women than human tubal fluid

Objective: To compare oocyte maturation, fertilization and cleavage rates, and embryonic developmental quality after culture of human immature oocytes from polycystic ovary syndrome (PCOS) patients in human tubal fluid (HTF) or tissue culture medium (TCM) 199. Design: Prospective, randomized, controlled trial. Setting: University hospital. Patient(s): Thirteen women undergoing 23 in vitro maturation cycles, from whom 119 oocytes were retrieved. Intervention(s): Cumulus-enclosed germinal vesicle-stage oocytes matured in TCM-199-supplemented or HTF-supplemented media. Main Outcome Measure(s): Oocyte maturation and fertilization rates, embryonic developmental quality. Result(s): Significant differences were observed between TCM 199 and HTF regarding maturation rate (82% vs. 56.9%), fertilization rate (70% vs. 39.4%), and embryo quality (81.3% vs. 41.7%). Conclusion(S): Human tubal fluid medium, although widely used for embryo fertilization and maintenance in IVF techniques, is not,in appropriate medium for the maturation of oocytes obtained from PCOS patients in nonstimulated cycles. (Fertil Steril(R) 2009;91:509-13. (C)2009 by American Society for Reproductive Medicine.)

Lipid peroxidation and vitamin E in serum and follicular fluid of infertile women with peritoneal endometriosis submitted to controlled ovarian hyperstimulation: a pilot study

Objective: To assess the level of lipid peroxidation (LP) and vitamin E in the follicular fluid and serum of infertile patients, with or without endometriosis. who were submitted to ovulation induction for assisted reproduction procedures. Design: Prospective study. Setting: Assisted conception unit, university hospital. Patient(s): Infertile patients 20 to 38 years of age were selected prospectively and consecutively and were divided into the endometriosis group (17 patients with pelvic endometriosis) and the control group (19 patients with previous tubal ligation or male factor and without endometriosis). Intervention(s): Peripheral blood samples were collected on D1 (before the beginning of the use of gonadotropins), D2 (day of hCG administration), and D3 (day of oocyte retrieval). On D3, follicular-fluid samples free from blood contamination also were collected and stored. Main Outcome Measure(S): Lipid peroxidation was assessed by malondialdehyde quantification by spectrophotometry, and measurement of vitamin E was performed by HLPC. Result(s): On D1, no significant difference in LP was observed between groups. However, vitamin E levels were significantly higher in the control group. On D2, LP levels were significantly higher in the endometriosis group compared with in the control group, and vitamin E levels continued to be significantly higher in the control group. On D3, there was no significant difference in serum and follicular-fluid levels of LP and vitamin E between groups. However, on D3, vitamin E levels were found to be significantly higher in serum than in follicular fluid in both groups, whereas malondialdchyde levels were significantly lower in follicular fluid than in serum only in the control group. Conclusion(s): Before the beginning of ovulation induction, a significant decrease in vitamin E was observed in patients with endometriosis, perhaps because antioxidants are consumed during oxidation reactions. After ovulation induction with exogenous gonadotropins, the group of patients with endometriosis not only presented increased lipid peroxidation but also maintained lower vitamin E levels than the control group, a fact that hypothetically could compromise oocyte quality in endometriotic patients. However, on the day of oocyte retrieval, both serum LP potential and vitamin E levels were found to be similar in the two groups. (Fertil Steril(R) 2008; 90:2080-5. (C) 2008 by American Society for Reproductive Medicine.)

Occult risk factor for the development of cerebral edema in children with diabetic ketoacidosis: possible role for stomach emptying

The incidence of cerebral edema during therapy of diabetic ketoacidosis (DKA) in children remains unacceptably high-this suggests that current treatment may not be ideal and that important risk factors for the development of cerebral edema have not been recognized. We suggest that there are two major sources for an occult generation of osmole-free water in these patients: first, fluid with a low concentration of electrolytes that was retained in the lumen of the stomach when the patient arrived in hospital; second, infusion of glucose in water at a time when this solution can be converted into water with little glucose. In a retrospective chart review of 30 patients who were admitted with a diagnosis of DKA and a blood sugar > 900 mg/dL (50 mmol/L), there were clues to suggest that some of the retained fluid in the stomach was absorbed. To minimize the likelihood of creating a dangerous degree of cerebral edema in patients with DKA, it is important to define the likely composition of fluid retained in the stomach on admission, to look for signs of absorption of some of this fluid during therapy, and to be especially vigilant once fat-derived brain fuels have disappeared, because this is the time when glucose oxidation in the brain should increase markedly, generating osmole-free water.

Hydrocephalus in posterior fossa tumors in children. Are there factors that determine a need for permanent cerebrospinal fluid diversion?

We searched for factors that could predispose towards persistent hydrocephalus in children with posterior fossa (PF) tumors in order to determine the need for permanent cerebrospinal fluid (CSF) diversion. The clinical records of 64 children who underwent surgery for PF tumors in the Pediatric Neurosurgery division of the Hospital of Clinics, Ribeirao Preto, Brazil, from 1990 to 2006, were retrospectively reviewed. The patients` ages ranged from 3 months to 18 years. The factors evaluated included age at surgery, severity of hydrocephalus (ventricular index), tumor location, size of the tumor, extent of tumor resection, and histology. Ventricular index, measured from the initial neuroradiological image, age at surgery, and location of the tumor were significantly associated with definitive postoperative CSF diversion (shunt or endoscopic third ventriculostomy), which was necessary for 34% of the patients. Young children with severe preoperative hydrocephalus and a midline tumor should be considered at risk when preoperative treatment decisions are made.

Sildenafil improves the beneficial haemodynamic effects of intravenous nitrite infusion during acute pulmonary embolism

Acute pulmonary embolism produces acute pulmonary hypertension, which can be counteracted by activating the nitric oxide-cyclic guanosine 3`,5`-monophosphate (cGMP) pathway. While previous studies have shown that sildenafil (an inhibitor of cGMP-specific phosphodiesterase type 5) or nitrite (a storage molecule for nitric oxide) produces beneficial effects during acute pulmonary embolism, no previous study has examined whether the combination of these drugs can produce additive effects. Here, we expand previous findings and examine whether sildenafil enhances the beneficial haemodynamic effects produced by a low-dose infusion of nitrite in a dog model of acute pulmonary embolism. Haemodynamic and arterial blood gas evaluations were performed in non-embolized dogs treated with saline (n = 4), and in embolized dogs (intravenous injections of microspheres) that received nitrite (6.75 mu mol/kg intravenously over 15 min. followed by 0.28 mu mol/kg/min.) and sildenafil (0.25 mg/kg over 30 min.; n = 8), or nitrite followed by saline (n = 8), or saline followed by sildenafil (n = 7), or only saline (n = 8). Plasma thiobarbituric acid-reactive substances (TBARS) concentrations were determined using a fluorometric method. Acute pulmonary embolism increased pulmonary artery pressure by similar to 24 mmHg. While the infusion of nitrite or sildenafil infusions reversed this increase by similar to 42% (both P < 0.05), the combined infusion of both drugs reversed this increase by similar to 58% (P < 0.05). Similar effects were seen on the pulmonary vascular resistance index. Nitrite or sildenafil alone produced no significant hypotension. However, the combined infusion of both drugs caused transient hypotension (P < 0.05). Both dugs, either alone or combined, blunted the increase in TBARS concentrations caused by acute pulmonary embolism (all P < 0.05). These results suggest that sildenafil improves the beneficial haemodynamic effects of nitrite during acute pulmonary embolism.