Serrumab: a human monoclonal antibody that counters the biochemical and immunological effects of Tityus serrulatus venom

In Brazil, the species Tityus serrulatus is responsible for the most severe cases of scorpion envenomation. There is currently a need for new scorpion anti-venoms that are more effective and less harmful. This study attempted to produce human monoclonal antibodies capable of inhibiting the activity of T. serrulatus venom (TsV), using the Griffin.1 library of human single-chain fragment-variable (scFv) phage antibodies. Four rounds of phage antibody selection were performed, and the round with the highest phage antibody titer was chosen for the production of monoclonal phage antibodies and for further analysis. The scFv 2A, designated serrumab, was selected for the production and purification of soluble antibody fragments. In a murine peritoneal macrophage cell line (J774.1), in vitro assays of the cytokines interleukin (IL)-6, tumor necrosis factor (TNF)-α, and IL-10 were performed. In male BALB/c mice, in vivo assays of plasma urea, creatinine, aspartate transaminase, and glucose were performed, as well as of neutrophil recruitment and leukocyte counts. It was found that serrumab inhibited the TsV-induced increases in the production of IL-6, TNFα, and IL-10 in J774.1 cells. The in vivo inhibition assay showed that serrumab also prevented TsV-induced increases in the plasma levels of urea, creatinine, aspartate transaminase, and glucose, as well as preventing the TsV-induced increase in neutrophil recruitment. The results indicate that the human monoclonal antibody serrumab is a candidate for inclusion in a mixture of specific antibodies to the various toxins present in TsV. Therefore, serrumab shows promise for use in the production of new anti-venom.     

Lutzomyia (Pintomyia) fischeri (Diptera: Psychodidae: Phlebotominae), a probable vector of American cutaneous leishmaniasis: detection of natural infection by Leishmania (Viannia) DNA in specimens from the municipality of Porto Alegre (RS), Brazil, using multiplex PCR assay

In order to determine natural Leishmania (Viannia) infection in Lutzomyia (Pintomyia) fischeri, a multiplex PCR methodology coupled to non-isotopic hybridization was adopted for the analysis of sand fly samples collected by CDC light traps in an endemic area of American Cutaneous Leishmaniasis (ACL) in the periurban region of the municipality of Porto Alegre, Rio Grande do Sul State, Brazil. We analyzed by PCR methodology 560 specimens of Lutzomyia (Pintomyia) fischeri (520 females and 40 males). The wild sand flies were grouped into 56 pools (52 females and 4 males) of 10 each, and positive results were detected in 2 of the 52 female pools, representing a minimum infection rate of 0.38% based on the presence of at least 1 infected insect in the pool. This result associated with some local evidence such as anthopophily, spatial distribution in accordance with the transmission area and human case incidence, suggests that L. (P.)fischeri may be considered as a secondary vector of ACL in the studied locality.     

Exposure of C6 glioma cells to Pb(II) increases the phosphorylation of p38<Superscript>MAPK</Superscript> and JNK1/2 but not of ERK1/2

Pb(II) is a neurotoxic pollutant that produces permanent cognitive deficits in children. Pb(II) can modulate cell signaling pathways and cell viability in a variety of cell types. However, these actions are not well demonstrated on glial cells, which represent an important target for metals into the central nervous system. The present work was undertaken to determine the ability of Pb(II) in modulating the activity of mitogen activated protein kinases (MAPKs) in cultures of C6 rat glioma cells, a useful functional model for the study of astrocytes. Additionally, cell viability was analyzed by measurement of MTT reduction. Cells were exposed to lead acetate 0.1, 1, 10 μM for 24 and 48 h. MAPKs activation—in particular ERK1/2, p38^MAPK and JNK1/2—were analyzed by western blotting. Results showed that 10 μM Pb(II) treatment for 24 h caused a discrete stimulation of p38^MAPK phosphorylation. However, 1 and 10 μM Pb(II) treatment for 48 h provoked a significant stimulation in the phosphorylation state of p38^MAPK and JNK1/2. The phosphorylation state of ERK1/2 was not modified by any Pb(II) treatment. Moreover, data indicate that at 48 h treatment even 1 μM Pb(II) can be cytotoxic, causing impairment on cell viability. Therefore, depending on a long incubation period, a significant concomitant activation of p38^MAPK and JNK1/2 by Pb(II) took place in parallel with the impairment of C6 glioma cells viability.     

Hip fracture in Auckland: contrasting models of care in two major hospitals

Background:  The optimal setting and design of care for elderly patients with hip fracture is unknown. North Shore Hospital (NSH) and Middlemore Hospital (MMH) are two major hospitals in the Auckland region operating different models of orthogeriatric care. The aim of the study was to compare hip fracture care between NSH and MMH.
Methods:  A retrospective case record audit of patients aged 65 years and older with hip fracture from July to December 2004 at MMH and NSH was carried out.
Results:  Charts for 203 patients (101 MMH and 102 NSH) were reviewed. The two groups were similar in age (mean age 83.2 years), sex (80% women) and other casemix factors. Median time from admission to theatre was shorter in NSH (21 vs 44 h, P  < 0.0001). Length of stay was significantly shorter at NSH (mean difference 4.4 days, 95% confidence interval 1.1–7.6 when adjusted for casemix factors). Significantly more NSH patients were transferred for rehabilitation than MMH patients (75 vs 51%). At discharge, significantly more MMH patients (34 vs 14%) were treated with alendronate. Of 126 patients admitted from home, 81% returned home, 4% went to rest homes, 13% to private hospitals and 2% died; differences between centres were not significant. Overall inpatient mortality was 3.9%.
Conclusion:  The orthogeriatric model of care at NSH was associated with a shorter overall length of stay, earlier transfer to the Assessment, Treatment and Rehabilitation setting, and a higher proportion rehabilitated in Assessment, Treatment and Rehabilitation. Outcomes in terms of discharge destination and 6-month mortality were similar at both centres.     

Hypotensive and Vasorelaxant Effects of Citronellol,a Monoterpene Alcohol,in Rats

Abstract: Citronellol is an essential oil constituent from the medicinal plants Cymbopogon citratus, Cymbopogon winterianus and Lippia alba which are thought to possess antihypertensive properties. Citronellol‐induced cardiovascular effects were evaluated in this study. In rats, citronellol (1–20 mg/kg, i.v.) induced hypotension, which was not affected by pre‐treatment with atropine, hexamethonium, N^ω‐nitro‐l ‐arginine methyl ester hydrochloride or indomethacin, and tachycardia, which was only attenuated by pre‐treatment with atropine and hexamethonium. These responses were less than those obtained for nifedipine, a reference drug. In intact rings of rat mesenteric artery pre‐contracted with 10 μM phenylephrine, citronellol induced relaxations (pD₂ = 0.71 ± 0.11; E_max = 102 ± 5%; n = 6) that were not affected by endothelium removal, after tetraethylamonium in rings without endothelium pre‐contracted with KCl 80 mM. Citronellol strongly antagonized (maximal inhibition = 97 ± 4%; n = 6) the contractions induced by CaCl₂ (10^?6 to 3 × 10^?3 M) and did not induce additional effects on the maximal response of nifedipine (10 μM). Finally, citronellol inhibited the contractions induced by 10 μM phenylephrine or 20 mM caffeine. The present results suggest that citronellol lowers blood pressure by a direct effect on the vascular smooth muscle leading to vasodilation.     

Unravelling the cardiovascular effects induced by α‐terpineol: A role for the nitric oxide–cGMP pathway

1. α‐Terpineol is a monoterpene found in the essential oils of several aromatic plant species. In the present study, we investigated the mechanisms underlying the cardiovascular changes induced by α‐terpineol in rats. 2. In normotensive rats, administration of α‐terpineol (1, 5, 10, 20 and 30 mg/kg, i.v.) produced a dose‐dependent hypotension (?10 ± 3, ?20 ± 8, ?39 ± 16, ?52 ± 21 and ?57 ± 23 mmHg, respectively; n = 5) followed by tachycardia. The hypotensive responses to 1, 5, 10, 20 and 30 mg/kg, i.v., α‐terpineol were significantly attenuated following the administration of N^G‐nitro‐l‐ arginine methyl ester (l ‐NAME; 20 mg/kg, i.v.; ?2 ± 1, ?5 ± 2, ?7 ± 3, ?22 ± 9 and ?22 ± 10 mmHg, respectively; P < 0.05; n = 5). 3. In 10 μmol/L phenylephrine (PE)‐precontracted mesenteric artery rings, α‐terpineol (10^?12 to 10^?5 mol/L) caused a concentration‐dependent relaxation (maximum relaxation 61 ± 6%; n = 7). After removal of the endothelium, the vasorelaxation elicited by α‐terpineol was attenuated (maximum relaxation 20 ± 1%; P < 0.05; n = 7). In addition, vasorelaxation induced by α‐terpineol in rings pretreated with 100 or 300 μmol/L l ‐NAME, 30 μmol/L hydroxocobalamin or 10 μmol/L 1H‐[1,2,4]oxadiazolo[4,3‐a]quinoxalin‐1‐one was attenuated (maximum relaxation 18 ± 3, 23 ± 3, 24 ± 7 and 21 ± 1%, respectively; n = 6; P < 0.05). 4. Furthermore, in a rabbit aortic endothelial cell line, 10^?6, 10^?5 and 10^?4 mol/L α‐terpineol induced concentration‐dependent increases in nitric oxide (NO) levels (12 ± 6, 18 ± 9 and 34 ± 12%Δ fluorescence, respectively; n = 3). 5. In conclusion, using combined functional and biochemical approaches in the present study, we were able to demonstrate that α‐terpineol‐induced hypotension and vasorelaxation are mediated, at least in part, by the endothelium, most likely via NO release and activation of the NO–cGMP pathway.     

Comparative study between DD-HMM and RBF in ventricular tachycardia and ventricular fibrillation recognition

This paper deals with automatic recognition of cardiac arrhythmias that require immediate electrical defibrillation therapy (ventricular fibrillation and ventricular tachycardia), through ECG (electrocardiogram) samples. The DD-HMM (discrete density hidden Markov model) and RBF (radial basis function) neural network algorithms were compared in the following aspects: precision, defined as correct recognition percentage and process time, defined as the delay since the ECG input until the result, indicating shock or non-shock events. The results show that RBF is more precise than DD-HMM but not so fast to evaluate. PhysioNet database files were used to train and to validate the algorithms.     

Protease activity in extracellular products secreted in vitro by trophozoites of <Emphasis Type="Italic">Giardia duodenalis</Emphasis>

There are evidences that Giardia trophozoites contain and/or release proteolytic enzymes that may be implicated in pathogenesis of giardiasis. This report describes a preliminary characterization of the proteolytic activity in excretory/secretory (E/S) products of Giardia duodenalis trophozoites of an axenic Brazilian strain (BTU-11) and the reference strain Portland 1 (P1). The protease activity of E/S products in conditioned medium by trophozoites of each strain was analyzed using substrate (gelatin and collagen) impregnated SDS-PAGE and hemoglobin assay. The protease characterization was based on inhibition assays including synthetic inhibitors. Proteolytic products were detected in the conditioned medium by trophozoites of both assayed strains. In the gels containing copolymerized gelatin and collagen, E/S products promoted degradation of the substrates and the most evident proteolysis zones were distributed in the migration regions of 77 to 18 kDa and 145 to 18 kDa, respectively, in the patterns of gelatinolytic and collagenolytic activities. Degradation of hemoglobin was also observed, and the pattern of hydrolysis was similar in both E/S products assayed. Inhibition assays showed that the main proteolytic activity in both E/S products is due to cysteine proteases although the presence of serine proteases was also indicated, mainly in the hydrolysis of hemoglobin.