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Background: The World Health Organization added snakebite envenoming to its priority list of neglected tropical diseases. Snakebite envenoming is a particularly important public health problem in rural areas of tropical and sub-tropical countries. In 2017, more than 30 thousand cases of snakebites were reported in Brazil, with the North and Northeast regions being the most affected and Bothrops sp snakes causing most of these cases. Objective:: The objective of this study was to evaluate, in vitro, the coagulating, cytotoxic, oxidizing and antioxidant effects caused by Bothrops jararacussu and B. moojeni crude venoms. Methods:: The crude venoms protein profiles were characterized, and the biological effects were evaluated and compared between the species. Results: The crude venoms composition showed similar protein profiles. The B. jararacussu and B. moojeni crude venoms showed coagulant activity and were capable of causing indirect hemolysis on the erythrocyte membrane, but did not protect the erythrocyte membrane from damage against hypotonic solutions. The B. jararacussu crude venom promoted hemagglutination. Conclusion: The crude venoms were not able to promote an oxidizing effect on hemoglobin and could not prevent the phenylhydrazine oxidizing effect; however, the crude venoms presence caused increase in the methemoglobin formation by phenylhydrazine oxidation.

Background: Type-2-diabetes mellitus is associated with many side effects affecting vital body organs, especially heart. Thiazolidinediones are potent antidiabetics. Studies have proven that amino-acids and peptides promote glucose transport, have antioxidant properties, and fewer side effects, thus we designed hybrids by combining amino-acid esters and peptide esters with 2, 4 thiazolidinedione acetic acid moiety which can act as antidiabetic agent with cardioprotection properties. Methodology: In vitro ADME, toxicity, and docking studies were performed using Qikprop3.1.OSIRIS, PROTOX (Prediction of Rodent Oral Toxicity), and FlexX 2.1.3, respectively. Results: All the designed molecules belong to three sub-series, i.e. 2, 4-dioxothiazolidine-5-acetic acid single amino acid hybrid methyl esters, 2, 4-dioxothiazolidine-5-acetic acid dipeptide hybrid methyl esters and 2, 4-dioxothiazolidine-5-acetic acid tripeptide hybrid methyl esters. All molecules were non-toxic. SSMA2, SSMA14, SSMA49, and SSDM50 showed good docking scores in 2PRG and 2UV4, respectively. Conclusion: The selected in silico studies helped to design hybrids with less toxicity, target specificity with dual activity as potential anti-diabetic and cardioprotective agents.

The Rv2633c gene of Mycobacterium tuberculosis, which plays a role in infection, encodes a hemerythrin-like protein (HLP). The crystal structure of an orthologue of Rv2633c, the HLP from Mycobacterium kansasii, revealed that it possessed structural features that were distinct from other hemerythrins and HLPs. These and other orthologous proteins comprise a distinct class of non-heme di-iron HLPs that are only found in mycobacteria. This study presents an analysis and comparison of protein sequences, putative structures, and evolutionary relationship of HLPs from 20 mycobacterial species that are known to cause tuberculosis or pulmonary disorders in humans. The results of this analysis allowed correlation of the physicochemical characteristics of amino acid residues that are substituted in these highly conserved sequences with their position in structures, possible effects on function, and evolutionary relationships. The sequences of the proteins from M. tuberculosis, Mycobacterium bovis, and other members of the M. tuberculosis complex, which cause tuberculosis, have substitutions not seen in the other non-tuberculous mycobacteria. Furthermore, groups of species that are closely related, based on phylogenetic analysis, possess substitutions of otherwise conserved residues not seen in other species that are less related. This information is correlated with the occurrence and clinical presentations of these groups of mycobacterial species. The results of this study provide a framework for structure–function studies to determine how subtle differences in the primary sequences of members of this family of proteins correlate with their structures and activities and how this may influence the infectious properties of the host species.

Malignant hyperthermia (MH) is an acute pharmacogenetic disorder, which while uncommon is potentially fatal. MH is a calcium channelopathy of skeletal muscle in which a constant increase of intracytoplasmic Ca2+ concentration occurs causing a change in cellular metabolism. A hypermetabolic state develops when susceptible patients are exposed to halogenated volatile inhalational anesthetic agents and depolarizing muscle relaxants and/or extreme physical activity in hot environments. MH presents variable clinical expression. During an episode of MH, the patient may present clinical signs and laboratory findings including masseter muscle spasm, tachycardia, rise in end-tidal CO2 (EtCO2), tachypnea, hyperthermia, cyanosis, metabolic acidosis, rhabdomyolysis, hyperkalemia, myoglobinuria, hyperlactacidemia, and acute renal failure. The aim of this case report is to describe an episode of MH associated with the use of halogenated anesthetic during bariatric surgery. A 29-year-old Brazilian man was admitted to the hospital to undergo a bariatric surgery. The patient’s relevant medical history included morbid obesity grade III, allergy to sulfa-based drugs and severe obstructive sleep apnea. Preoperative evaluations with cardiopulmonary exercise testing, echocardiogram and electrocardiogram showed no anatomical and functional changes of the patient’s heart. Surgical procedures lasted for 4 h, without complications, but the evolution of the patient’s condition indicated oliguria and acute breathing insufficiency. Five hours after the patient was placed under mechanical ventilation in the intensive care unit, he started to present clinical signs of hypermetabolic state, with tremors, excessive sweating, and rapid body temperature increases. In the postoperative period, the patient had hyperglycemia, hypocalcemia, hypernatremia, hyperkalemia, changes in creatine phosphokinase (CPK), aspartate transaminase (AST), alanine aminotransferase (ALT), urea and creatine concentrations, and metabolic and respiratory acidosis. Urinalysis showed traces of proteinuria, presence of ketones, leukocytes, red blood cells, and urobilinogen. In our case report, MH crisis was diagnosed late; the dantrolene was not administrated because it was not available and the patient died. This detailed case report of MH episode triggered by isoflurane anesthetic during bariatric surgery allowed us to describe the severity and lethality of this hypermetabolic syndrome. Dantrolene should be mandatory in all operating rooms. Knowledge of the symptoms, an early diagnosis and an adequate treatment can prevent the death of patients in MH crisis.

Crude venom ofBothrops jararacussuand isolated phospholipases A2(PLA2) of this toxin (BthTX-I and BthTX-II) were chemically modified (alkylation) byp-bromophenacyl bromide (BPB) in order to study antibody production capacity in function of the structure-function relationship of these substances (crude venom and PLA2native and alkylated). BthTX-II showed enzymatic activity, while BthTX-I did not. Alkylation reduced BthTX-II activity by 50% while this process abolished the catalytic and myotoxic activities of BthTX-I, while reducing its edema-inducing activity by about 50%. Antibody production against the native and alkylated forms of BthTX-I and -II and the cross-reactivity of antibodies to native and alkylated toxins did not show any apparent differences and these observations were reinforced by surface plasmon resonance (SPR) data. Histopathological analysis of mouse gastrocnemius muscle sections after injection of PBS, BthTX-I, BthTX-II, or both myotoxins previously incubated with neutralizing antibody showed inhibition of the toxin-induced myotoxicity. These results reveal that the chemical modification of the phospholipases A2(PLA2) diminished their toxicity but did not alter their antigenicity. This observation indicates that the modified PLA2may provide a biotechnological tool to attenuate the toxicity of the crude venom, by improving the production of antibodies and decreasing the local toxic effects of this poisonous substance in animals used to produce antivenom.

The benefits from treatment with antivenom sera are indubitable. However, the mechanism for toxin neutralization has not been completely elucidated. A mixture of anti-bothropic and anti-crotalic horse antivenom has been reported to be more effective in neutralizing the effects of Bothrops jararacussu snake venom than anti-bothropic antivenom alone. This study determined which regions in the three PLA2s from B. jararacussu snake venom are bound by antibodies in tetravalent anti-bothropic and monovalent anti-crotalic commercial horse antivenom. Mapping experiments of BthTX-I, BthTX-II and BthA-I using two small libraries of 69 peptides each revealed six major IgG-binding epitopes that were recognized by both anti-bothropic and anti-crotalic horse antivenom. Two epitopes in BthTX-I were only recognized by the anti-bothropic horse antivenom, while anti-crotalic horse antivenom recognized four unique epitopes across the three PLA2s. Our studies suggest that the harmful activities of the PLA2s present in the venom of B. jararacussu are neutralized by the combinatorial treatment with both antivenom sera through their complementary binding sites, which provides a wide coverage on the PLA2s. This is the first peptide microarray of PLA2s from B. jararacussu snake venom to survey the performance of commercial horse antiophidic antivenom. Regions recognized by the protective antivenom sera are prime candidates for improved venom cocktails or a chimeric protein encoding the multiple epitopes to immunize animals as well as for designing future synthetic vaccines.

A report which includes patient problems, descriptions of clinical and instrumental assessment and conclusion with suggestions for decision making, is a necessary tool for an adequate approach to the patient. In this paper we tried to define those steps we believe to be useful to produce a clinical report for patients with ambulation disability submitted to dynamic gait emg: Brief description of the patient's history; Description of the deformities; Observational gait analysis; Report of the items relevant to the deformities and/or relevant for treatment proposals; List of recorded muscles; Emg timing pattern; Conclusions leading to treatment proposals. The emg timing pattern can be useful for the identification of peripheral and central impairments (contracture, paretic, spastic, co-contraction components), which can significantly interfere with the gait profile of the single patient. We can use forms and tables which include emg signals features and recording parameters, physical examination and observational gait analysis notes. Attention must be paid for an adequate support of literature. Patients with upper motoneuron (UM) lesions frequently present impairments in lower limb function which influence normal walking. Gait rehabilitation is an important goal because the ability to walk significantly influences the patients' chances of successfully returning to their premorbid environment. To improve the gait of the patients, therapists and rehabilitation teams attempt to improve the various impairments of hemiparetic subjects, such as paretic lower limb muscle strength, balance, motor function, sensation, and muscle tone. Consequently, it is important to understand the characteristics and underlying motor control of gait in patients with UM lesions. Human gait is conventionally described in terms of "gait cycle"(GC) and represents a sequence of events between two sequential initial contacts with the floor by the same limb. The gait cycle is divided into two principal periods: stance and swing. The stance is usually considered the first period of GC and corresponds to when the foot is on the ground for the entire period and lasts for approximately the first 60% of GC time, the swing period begins as the foot is lifted from the floor and continues for the last 40% of the cycle. J. Perry (1) subdivided gait cycle and the stance and swing periods into three functional tasks; each task includes some phases: 1) During the Weight Acceptance (10% of the GC) the challenge is the transfer of body weight onto a limb that has just finished swinging and has an unstable alignment. It includes two phases: Initial Contact (IC) which is the moment when the foot lands on the ground ( the way the foot makes contact will influence the limb's loading) and

Bothropstoxin I (BthTX-I), a non-catalytic and myotoxic Lys49-PLA2 from Bothrops jararacussu venom, has been crystallized alone and complexed with  -tocopherol inhibitor. These crystals have been shown to diffract X-rays be- tween 2.17 and 1.83 A resolution. The BthTX-I/ -tocopherol complex crystals are not isomorphous with those of the na- tive protein. This suggests the inhibitor binding has lead to changes in the quaternary structure and a different conforma- tion may have been obtained.

Crotoxin B (CB or Cdt PLA2) is a basic Asp49-PLA2 found in the venom of Crotalus durissus terrificus and it is one of the subunits that constitute the crotoxin (Cro). This heterodimeric toxin, main component of the C. d. terrificus venom, is completed by an acidic, nontoxic, and nonenzymatic component (crotoxin A, CA or crotapotin), and it is related to important envenomation effects such as neurological disorders, myotoxicity, and renal failure. Although Cro has been crystallized since 1938, no crystal structure of this toxin or its subunits is currently available. In this work, the authors present the crystal structure of a novel tetrameric complex formed by two dimers of crotoxin B isoforms (CB1 and CB2). The results suggest that these assemblies are stable in solution and show that Ser1 and Glu92 of CB1 and CB2, respectively, play an important role in the oligomerization. The tetrameric and dimeric conformations resulting from the association of the isoforms may increase the neurotoxicity of the toxin CB by the creation of new binding sites, which could improve the affinity of the molecular complexes to the presynaptic membrane. Proteins 2008. © 2008 Wiley-Liss, Inc.

We investigated the clinical and MRI effects of mitoxantrone (MITOX) administered to 45 patients during the first five years of highly active relapsing-remitting multiple sclerosis. Differences occurring between the end of treatment and follow-up (clinical mean: 3.6 years; brain MR: 1.8 years) with respect to baseline variables (EDSS, annualized relapse rate, active T2 lesions, new T1 lesions and number of Gd-enhancing lesions) were analysed using parametric and non-parametric tests. One patient developed leukemia four months after the end of the treatment; no other serious adverse events occurred during treatment and the follow-up period. A clinically relevant reduction in the annualized relapse rate ( P < 0.0001 at end of treatment and P < 0.0001 at follow-up) and improvement in the EDSS ( P < 0.0001 at end of treatment and P = 0.0005 at follow-up) was found. At the end of treatment, 53% of patients experienced no increase in active T2 lesions, while 73% showed no increase in the number of new T1 lesions. At follow-up, 41 out of 45 (91%) patients showed a stable MRI pattern and were active-scan free. Despite potential serious adverse events, MITOX may be considered an option in selected patients with very active early MS. Multiple Sclerosis 2007; 13: 975—980. http://msj.sagepub.com

An innovative method for the regression of thermodynamic properties of pure fluids was recently proposed. The technique, indicated as an extended equation of state, adopts a framework similar to the extended corresponding states method, but a cubic equation is assumed instead of the equation of state of the reference fluid and the shape functions are expressed through a multilayer feedforward neural network. The use of a neural network assures a very high flexibility of the functional form to be regressed, so the resulting model reaches a representation accuracy which is comparable to that attained by the state-of-the-art multiparameter equations of state in the representation of the thermodynamic properties of a pure fluid. The technique was applied here to sulfur hexafluoride aiming at drawing its dedicated equation of state in a heuristic mode directly from the available experimental data. For sulfur hexafluoride (critical point is at Tc=318.7232K and Pc=3.754983MPa), experimental data of several prope...

The high level of the experimental precision recently reached in the measurement of speed of sound in the liquid region of fluids, together with the high thermodynamic worth of speed of sound, are the decisive elements increasing the interest in methods which allow to extract complete thermodynamic information from speed of sound data. This work presents a heuristic approach for the reduction of speed of sound data in the liquid region of a pure fluid into a fundamental dedicated equation of state. Contrarily to the methods reported in the literature for the present purpose, the proposed technique provides an analytical formulation rather than local values of the thermodynamic properties. A reduction procedure combining linear optimization procedure and non-linear multiproperty fitting was set up. The prediction capability of the method is presented for water as the interest fluid, over an extended pressure and temperature range of the liquid region; the comparisons with the available experimental values of several thermodynamic properties and with the recent IAPWS-95 equation are also given. The high quality of the obtained results assures that the proposed procedure can be regarded as an effective and robust method to draw a very precise equation of state for the liquid region of a fluid primarily from speed of sound data.

A three-parameter corresponding states model is proposed for the prediction of speed of sound surfaces of pure fluids and mixtures belonging to a homogeneous family of fluids as the halogenated alkanes. A preliminary conformality study is developed confirming the high potentiality of the corresponding states methods when applied within a property-dependent framework. A procedure that separately models the ideal-gas part and the residual contribution of the speed of sound surface is assumed. The ideal term is obtained for each target fluid from an individual equation for the ideal-gas isobaric heat capacity, whereas the residual term is represented with a three-parameter corresponding states technique introducing a fluid- and property-specific scaling parameter. A high effectiveness in the modeling of the whole speed of sound surface is obtained. The predictive character of the proposed model is evidenced by the few required inputs for a target fluid, i.e., a single speed of sound value at saturated liquid conditions for the assigned reduced temperature and its ideal-gas heat capacity function. The model format is directly extended to mixture simply by introducing enhanced mixing rules. The model has been successfully validated at both vapor and liquid conditions for 1978 experimental points of eight haloalkane fluids, obtaining the overall average absolute deviation (AAD) of 1.10%, and for mixtures in predictive mode for 927 experimental points, with the AAD of 0.62%. The correlative mode for mixtures has been applied to 600 points in the liquid region with an AAD of 0.67%, which is slightly better than the performance of the corresponding dedicated equations of state. The satisfactory results obtained assure the effectiveness of the proposed procedure.

A computer-operated static apparatus has been used for the measurement of the bubble pressures of the (1,1,1,2-tetrafluoroethane + triethylene glycol dimethyl ether) system at temperatures between (283 and 323) K in the composition range where the first component is prevailing, i.e., mainly for a mole fraction in the liquid phase greater than 0.7. The chosen ranges cover the most interesting conditions for the technical applications of such a mixture in refrigeration plants. The obtained experimental data constitute a set of 125 points distributed along five isotherms. The data have been correlated using a Wilson model for the activity coefficient, reaching satisfactory results; in fact the average absolute value of the relative deviation of the experimental bubble pressure from the model is 0.16 · 10−2. At high temperatures, the mixtures with low content of triethylene glycol dimethyl ether show positive deviations from Raoult’s law, whereas the other cases are characterized by negative deviations.

This work is the extension of previous work dedicated to pure fluids. The same method is extended to the representation of thermodynamic properties of a mixture through a fundamental equation of state in terms of the Helmholtz energy. The proposed technique exploits the extended corresponding-states concept of distorting the independent variables of a dedicated equation of state for a reference fluid using suitable scale factor functions to adapt the equation to experimental data of a target system. An existing equation of state for the target mixture is used instead of an equation for the reference fluid, completely avoiding the need for a reference fluid. In particular, a Soave–Redlich–Kwong cubic equation with van der Waals mixing rules is chosen. The scale factors, which are functions of temperature, density, and mole fraction of the target mixture, are expressed in the form of a multilayer feedforward neural network, whose coefficients are regressed by minimizing a suitable objective function involving different kinds of mixture thermodynamic data. As a preliminary test, the model is applied to five binary and two ternary haloalkane mixtures, using data generated from existing dedicated equations of state for the selected mixtures. The results show that the method is robust and straightforward for the effective development of a mixture- specific equation of state directly from experimental data.

A new technique is proposed here to represent the thermodynamic surface of a pure fluid in the fundamental Helmholtz energy form. The peculiarity of the present method is the extension of a generic equation of state for the target fluid, which is assumed as the basic equation, through the distortion of its independent variables by individual shape functions, which are represented by a neural network used as function approximator. The basic equation of state for the target fluid can have the simple functional form of a cubic equation, as, for instance, the Soave–Redlich–Kwong equation assumed in the present study. A set of nine fluids including hydrocarbons, haloalkane refrigerants, and strongly polar substances has been considered. For each of them the model has been regressed and then validated against volumetric and caloric properties generated in the vapor, liquid, and supercritical regions from highly accurate dedicated equations of state. In comparison with the underlying cubic equation of state, the prediction accuracy is improved by a factor between 10 and 100, depending on the property and on the region. It has been verified that about 100 density experimental points, together with from 10 to 20 coexistence data, are sufficient to guarantee high prediction accuracy for different thermodynamic properties. The method is a promising modeling technique for the heuristic development of multiparameter dedicated equations of state from experimental data.

The application of an optimization technique to the available experimental data has led to the development of a new multiparameter equation λ = λ (T,ρ ) for the representation of the thermal conductivity of 1,1-difluoroethane (R152a). The region of validity of the proposed equation covers the temperature range from 220 to 460 K and pressures up to 55 MPa, including the near-critical region. The average absolute deviation of the equation with respect to the selected 939 primary data points is 1.32%. The proposed equation represents therefore a significant improvement with respect to the literature conventional equation. The density value required by the equation is calculated at the chosen temperature and pressure conditions using a high accuracy equation of state for the fluid.

The flow boiling inside horizontal smooth tubes is studied for mixtures and a new modeling technique is proposed for the heat transfer. In a former work, the flow boiling of pure fluids inside smooth tubes was studied with artificial neural networks (ANN), obtaining individual heat transfer equations in a totally heuristic mode from the direct regression of experimental data. In the present work the method is extended to mixtures. Also in this case the correlation architectures considered for the ANN functions were based on the directly-accessible physical quantities controlling the phenomenon. Two modeling architectures are set up: a first one with the controlling physical quantities as independent variables and a second one where the inputs are the individual heat transfer values of the pure components and the mixture composition. The validation of both the obtained models demonstrate an accurate and substantially equivalent representation of the available heat transfer data with a considerable increase of prediction capability with respect to the conventional methods. The multilayer feedforward neural network equations both in terms of physical variables and in terms of components heat transfer models and composition have obtained very satisfactory accuracies. The modeling technique allows to avoid the need for any thermodynamic and transport property model for the target mixture and, moreover, the method can be used to check the consistency of new data sets before using them for processing.

A new multiparameter equation λ = λ(T, ρ) for the thermal conductivity of R134a has been developed from the available experimental data using a technique for the optimization of the functional form. The equation is valid in the temperature range from 200 to 540 K and for pressure up to 70 MPa, including also the near-critical region. The satisfactory performances of the equation are summarized by an average absolute deviation of 2.04% for the selected 5102 primary data points, with a significant improvement with respect to the present reference equation from the literature. The conversion of the independent variables of the experimental data into those of the equation, i.e. (T, P) into (T, ρ), is performed with a high accuracy equation of state for the fluid.

The heat transfer modeling of flow boiling inside horizontal tubes at saturation conditions is studied. The conventional models in the literature tend to modify an elementary historical correlation trying to empirically follow the heat flux trends as evidenced by the experimental data. The problem basically constitutes a highly non-linear phenomenon for which it is advisable to use a very flexible function approximator to draw case-specific heat transfer coefficient correlations from the experimental data alone. Artificial neural networks (ANN) were here used for this purpose, proving able to precisely represent conventional heat transfer surfaces. The most synthetic correlation architecture, based on the directly-accessible physical quantities controlling the phenomenon as independent variables, was considered for the ANN function. Eight pure fluids and a constant composition ternary mixture were studied and for each of them an individual heat transfer equation was obtained in the same ranges of the respective data set. With respect to data these ANN equations reach individual absolute average deviations of few parts per cent with biases virtually null. The obtained accuracy is lower than the claimed experimental uncertainties, but the heuristic technique also evidenced for the data both a frequent incoherence among the sets and a rather questionable reliability posing serious limits to the drawing of precise fluid specific heat transfer surfaces. A great improvement of performance with respect to five conventional correlations was found for the present modeling.

An optimization technique was applied to develop a functional form for a multiparameter viscosity equation η=η(ρ,T) for R134a. The results obtained are very promising, with an average absolute deviation of 0.55% for the currently available 549 primary data points. Compared to viscosity equations available in the literature, this is a significant improvement. Advantages become evident especially at gaseous states. As usual, both the development and the use of the viscosity equation require a highly accurate equation of state in order to convert the independent variables used for the experimental data and in most applications, (P,T), into the independent variables of the viscosity equation, (ρ,T). Though the equation was developed directly using the available data, the zero-density viscosity and the reduced second viscosity virial coefficient are correctly reproduced in the data range. The technique used to develop the equation, which is heuristic and not theoretically founded, is capable of selecting consi...

This paper represents the second part of a work devoted to an innovative version of the traditional extended corresponding states technique for the development of thermal conductivity equations on the whole λ, ρ, T surface for individual fluids. In the first part, the theoretical aspects of modeling the thermal conductivity surface of a pure fluid in the new extended corresponding states-neural networks format have been discussed; the fundamental characteristics of the proposed method have been tested using thermal conductivity values generated from dedicated thermal conductivity equations. The promising results formerly obtained suggest to move from generated to experimental data correlation in order to determine dedicated thermal conductivity equations for a number of fluids in real conditions of development. A suitable base of data is required for each fluid of interest. In this second part two fluids, the carbon dioxide and the haloalkane R152a, are studied. The haloalkane R134a is chosen as reference fluid for the model. The absolute average deviations obtained from primary data for the new thermal conductivity models in the extended corresponding states-neural networks format are 1.45% for R152a and 1.13% for carbon dioxide, with an improvement of these figures with respect to the existing equations in the literature. Considering that the expected experimental uncertainty for thermal conductivity data is generally not better than 2%, the obtained results seem to be very promising.

BnSP-7 and BnSP-6, two Lys49-phospholipase A2 isolated from Bothrops neuwiedi pauloensis snake venom, were co-crystallized with α-tocopherol and X-ray diffraction data were collected for both complexes (2.2 and 2.6 A). A new alternative quaternary conformation for these two complexes compared with all other dimeric Lys49-PLA2 has been observed.

The speed of sound in gaseous 1,1,1-trifluoroethane has been obtained at temperatures between (270 and 370) K from measurements of the resonance frequency of the radial modes of a spherical resonator. Ideal gas heat capacities and acoustic virial coefficients have been calculated from the results. The acoustic data have been used to determine density virial coefficients with a hard-core square-well intermolecular potential equation of state. A Helmholtz energy equation of state is proposed, whose parameters are directly fitted to the present speed of sound data and uses the acoustically determined temperature dependence of the perfect gas heat capacity. The Helmholtz equation so obtained compares favourably with other conventional methods and provides a high accuracy equation specific for the vapour phase of the fluid. The performance of the equation, in terms of the accuracy of the thermodynamic properties derived from it, has been determined by comparison of predicted densities with available experimental data. The equation of state shows very good extrapolation behaviour beyond the range of temperatures and pressures of the experimental data to which it was fitted.

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Objective: To determine the incidence and clinical effects of antibodies that develop during treatment with natalizumab. Methods: In two randomized, double-blind, placebo-controlled studies (natalizumab safety and efficacy in relapsing remitting multiple sclerosis [MS, AFFIRM] and safety and efficacy of natalizumab in combination with interferon β-1a [INFβ1a] in patients with relapsing remitting MS [SENTINEL]) of patients with relapsing multiple sclerosis, blood samples were obtained at baseline and every 12 weeks to determine the presence of antibodies against natalizumab. Antibodies to natalizumab were measured using an ELISA. Patients were categorized as “transiently positive” if they had detectable antibodies (≥0.5 μg/mL) at a single time point or “persistently positive” if they had antibodies at two or more time points ≥6 weeks apart. Results: In the AFFIRM study, antibodies were detected in 57 of 625 (9%) of natalizumab-treated patients: Twenty (3%) were transiently positive and 37 (6%) were persistently positive. Persistently positive patients showed a loss of clinical efficacy as measured by disability progression ( p ≤ 0.05), relapse rate ( p = 0.009), and MRI ( p ≤ 0.05) compared with antibody-negative patients. In transiently positive patients, full efficacy was achieved after approximately 6 months of treatment, the time when patients were becoming antibody negative. The incidence of infusion-related adverse events was significantly higher in persistently positive patients. Results of SENTINEL were similar to AFFIRM, except with regard to sustained disability progression; differences between persistently positive and antibody-negative patients were not statistically significant. Conclusions: The incidence of persistent antibody positivity associated with natalizumab is 6%. Reduced clinical efficacy is apparent in persistently positive patients. Patients with a suboptimal clinical response or persistent infusion-related adverse events should be considered for antibody testing. GLOSSARY: BLQ = below the limit of quantification; EDSS = Expanded Disability Status Scale; Gd+ = gadolinium enhancing; IFNβ1a = interferon β-1a; MS = multiple sclerosis; MSFC = multiple sclerosis functional composite; OD = optical density.

For the first time, a complete X-ray diffraction data set has been collected from a myotoxic Asp49-phospholipase A2 (Asp49-PLA2) with low catalytic activity (BthTX-II from Bothrops jararacussu venom) and a molecular-replacement solution has been obtained with a dimer in the asymmetric unit. The quaternary structure of BthTX-II resembles the myotoxin Asp49-PLA2 PrTX-III (piratoxin III from B. pirajai venom) and all non-catalytic and myotoxic dimeric Lys49-PLA2s. In contrast, the oligomeric structure of BthTX-II is different from the highly catalytic and non-myotoxic BthA-I (acidic PLA2 from B. jararacussu). Thus, comparison between these structures should add insight into the catalytic and myotoxic activities of bothropic PLA2s.

Ophidian envenomation is an important health problem in Brazil and other South American countries. In folk medicine, especially in developing countries, several vegetal species are employed for the treatment of snakebites in communities that lack prompt access to serum therapy. However, the identification and characterization of the effects of several new plants or their isolated compounds, which are able to inhibit the activities of snake venom, are extremely important and such studies are imperative. Snake venom contains several organic and inorganic compounds; phospholipases A2(PLA2s) are one of the principal toxic components of venom. PLA2s display a wide variety of pharmacological activities, such as neurotoxicity, myotoxicity, cardiotoxicity, anticoagulant, hemorrhagic, and edema-inducing effects. PLA2inhibition is of pharmacological and therapeutic interests as these enzymes are involved in several inflammatory diseases. This review describes the results of several studies of plant extracts and their isolated active principles, when used against crude snake venoms or their toxic fractions. Isolated inhibitors, such as steroids, terpenoids, and phenolic compounds, are able to inhibit PLA2s from different snake venoms. The design of specific inhibitors of PLA2s might help in the development of new pharmaceutical drugs, more specific antivenom, or even as alternative approaches for treating snakebites.

The benefits from treatment with antivenom sera are indubitable. However, the mechanism for toxin neutralization has not been completely elucidated. A mixture of anti-bothropic and anti-crotalic horse antivenom has been reported to be more effective in neutralizing the effects of Bothrops jararacussu snake venom than anti-bothropic antivenom alone. This study determined which regions in the three PLA₂s from B. jararacussu snake venom are bound by antibodies in tetravalent anti-bothropic and monovalent anti-crotalic commercial horse antivenom. Mapping experiments of BthTX-I, BthTX-II and BthA-I using two small libraries of 69 peptides each revealed six major IgG-binding epitopes that were recognized by both anti-bothropic and anti-crotalic horse antivenom. Two epitopes in BthTX-I were only recognized by the anti-bothropic horse antivenom, while anti-crotalic horse antivenom recognized four unique epitopes across the three PLA₂s. Our studies suggest that the harmful activities of the PLA₂s present in the venom of B. jararacussu are neutralized by the combinatorial treatment with both antivenom sera through their complementary binding sites, which provides a wide coverage on the PLA₂s. This is the first peptide microarray of PLA₂s from B. jararacussu snake venom to survey the performance of commercial horse antiophidic antivenom. Regions recognized by the protective antivenom sera are prime candidates for improved venom cocktails or a chimeric protein encoding the multiple epitopes to immunize animals as well as for designing future synthetic vaccines.

This paper describes a biochemical and pharmacological characterization of BpirPLA(2)-I, the first acidic Asp49-PLA(2) isolated from Bothrops pirajai. BpirPLA(2)-I caused hypotension in vivo, presented phospholipolytic activity upon artificial substrates and inhibitory effects on platelet aggregation in vitro. Moreover, a synthetic peptide of BpirPLA(2)-I, comprising residues of the C-terminal region, reproduced the antiplatelet activity of the intact protein. A cDNA fragment of 366 bp encompassing the mature form of BpirPLA(2)-I was cloned by reverse transcriptase-PCR of B. pirajai venom gland total RNA. A Bayesian phylogenetic analysis indicated that BpirPLA(2)-I forms a clade with other acid Asp49-PLA(2) enzymes from the Bothrops genus, which are characterized by the high catalytic activity associated with anticoagulant or hypotensive activity or both. Comparison of the electrostatic potential (EP) on the molecular surfaces calculated from a BpirPLA(2)-I homology model and from the crystallographic models of a group of close homologues revealed that the greatest number of charge inversions occurred on the face opposite to the active site entrance, particularly in the Ca(2+) ion binding loop. This observation suggests a possible relationship between the basic or acid character of PLA(2) enzymes and the functionality of the Ca(2+) ion binding loop.

The reliability of kinematic measurements has a top priority in gait analysis. The aim of the present work was to assess the inter-trial, inter-session and inter-examiner variability of an anatomical-based protocol by an established method. The gait of two young adult volunteers was analyzed by four examiners with different degrees of experience in three sessions 1 week apart. The data of five trials of level walking were collected and the rotations in the three anatomical planes of the pelvis, hip, knee and ankle were calculated. Themean value over the gait cycle of the standard deviation of these rotations wascalculated for each of the 24 groups of five trials (inter-trial), the eight groups of five trials multiplied by three sessions (intersession), and the two groups of five trials multiplied by three sessions multiplied by four examiners (interexaminer). For each rotation, the inter-examiner variability was larger than the inter-session, and the latter larger than the inter-trial. The present ratio between inter-examiner and inter-trial variability wasfound to be smaller than that of the conventional protocol for each of the gait variables. 2010 Elsevier B.V. All rights reserved.

This work aimed at the isolation and structural/functional characterization of a phospholipase A(2) (CgPLA(2)) from the extract of the anemone Condylactis gigantea. CgPLA(2) was isolated with a high purity level through three chromatographic steps, showing pI 8.6 and molecular weights of 14,500 and 29,000 for the monomer and dimer, respectively. CgPLA(2) showed a high catalytic activity upon fluorescent phospholipids inducing no direct hemolytic activity. This enzyme, which is Ca(2+)-dependent, showed a lower stability against temperature and pH variations when compared with snake venom enzymes. The enzymatic activity was significantly reduced or completely abolished after chemical modification of CgPLA(2) with BPB. Its cDNA was then obtained, with 357 base pairs which codified for a mature protein of 119 amino acid residues. A comparative analysis of the primary structure of CgPLA(2) revealed 84%, 61%, 43% and 42% similarity to the PLA(2)s from Adamsia carciniopados, Nematostella vectensis, Vipera russelli russelli and Bothrops jararacussu, respectively.

Arterial vascular anomalies rarely cause extrinsic ureteral obstruction and only 11 cases have been reported so far. This paper deals with an unusual extrinsic obstruction of the left ureter caused by a residue of the umbilical artery in a 37 years old man. The patient had left flank pain due to serious hydronephrosis on the same side. At operation a fibrous cord, a residue of the left umbilical artery, partially obstructed the distal left ureter. Partial left terminal ureterectomy with ureteroneocystostomy was performed. In the differential diagnosis of low extrinsic ureteral obstructions also the uncommon vascular anomalies of the umbilical artery should be taken into consideration.

Phospholipases A(2) (Asp49-PLA(2)s) are enzymes responsible for cellular membrane disruption through Ca(2+)-dependent hydrolysis of phospholipids. A class of these proteins (Lys49-PLA(2)s) does not show catalytic activity but can exert a pronounced local myotoxic effect that is not neutralized by serum therapy. In this work, we present five structures of Lys49-PLA(2)s from snakes of the Bothrops genus in apo form, complexed with PEG molecules and chemically modified by p-bromofenacil bromide (BPB), a classic inhibitor of PLA(2). We present herein an extensive structural analysis including: (i) the function of hydrophobic long-chain molecules as Lys49-PLA(2)s inhibitors, (ii) the role of Lys122, previously indicated as being responsible for Lys49-PLA(2)s catalytic inactivity and, (iii) a structural comparison of the Ca(2+)-binding loop region between Lys49 and Asp49-PLA(2)s. The Lys122 analysis of 30 different monomers for apo and complexed Lys49-PLA(2)s structures shows that this residue is very flexible and may bind to different carboxyl groups giving stability to the crystal structures. The structural comparisons of the Ca(2+)-binding loop region between Lys49 and Asp49-PLA(2)s reveal the importance of the Tyr28 residue conservation in Asp49-PLA(2)s to the integrity of this loop. The Tyr28 residue stabilizes this region by an interaction with Gly35 residue. In Lys49-PLA(2)s and low-catalytic Asp49-PLA(2)s this interaction does not occur, preventing the binding of Ca(2+).

Crotoxin B (CB or Cdt PLA(2)) is a basic Asp49-PLA(2) found in the venom of Crotalus durissus terrificus and it is one of the subunits that constitute the crotoxin (Cro). This heterodimeric toxin, main component of the C. d. terrificus venom, is completed by an acidic, nontoxic, and nonenzymatic component (crotoxin A, CA or crotapotin), and it is related to important envenomation effects such as neurological disorders, myotoxicity, and renal failure. Although Cro has been crystallized since 1938, no crystal structure of this toxin or its subunits is currently available. In this work, the authors present the crystal structure of a novel tetrameric complex formed by two dimers of crotoxin B isoforms (CB1 and CB2). The results suggest that these assemblies are stable in solution and show that Ser1 and Glu92 of CB1 and CB2, respectively, play an important role in the oligomerization. The tetrameric and dimeric conformations resulting from the association of the isoforms may increase the neurotoxicity of the toxin CB by the creation of new binding sites, which could improve the affinity of the molecular complexes to the presynaptic membrane.

Case summary Lumbosacral agenesis is a rare congenital condition reported in children. We report a 17-week-old female domestic shorthair cat with lumbosacral agenesis on whole-body radiographs. The cat was euthanized shortly thereafter presentation. A necropsy was not permitted. Relevance and novel information This is the first reported feline case of lumbosacral agenesis.

PrTX-I, a non-catalytic and myotoxic Lys49-PLA(2) from Bothrops pirajai venom has been crystallized alone and in complex with bromophenacyl bromide (BPB), alpha tocopherol and alpha tocopherol acetate inhibitors. These crystals have shown to diffract X-rays between 2.34 and 1.65 A resolution. All complexes crystals are isomorphous and belong to the space group P2(1) whereas native PrTX-I crystals belong to the P3(1)21.

Crotoxin B is a basic phospholipase A2 found in the venom of Crotalus durissus terrificus and is one of the subunits that constitute crotoxin. This heterodimeric toxin, which is the main component of C. d. terrificus venom, is completed by an acidic, nontoxic and non-enzymatic component (crotoxin A) and is involved in important envenomation effects, such as neurological disorders, myotoxicity and renal failure. Although crotoxin was first crystallized in 1938, no crystal structure is currently available for crotoxin, crotoxin A or crotoxin B. In this work, the crystallization, X-ray diffraction data collection to 2.28 A resolution and molecular-replacement solution of a novel tetrameric complex formed by two dimers of crotoxin B isoforms (CB1 and CB2) is presented.

A myotoxic Asp49-phospholipase A2 (Asp49-PLA2) with low catalytic activity (BthTX-II from Bothrops jararacussu venom) was crystallized and the molecular-replacement solution has been obtained with a dimer in the asymmetric unit. The quaternary structure of BthTX-II resembles the myotoxic Asp49-PLA2 PrTX-III (piratoxin III from B. pirajai venom) and all non-catalytic and myotoxic dimeric Lys49-PLA2S. Despite of this, BthTX-II is different from the highly catalytic and non-myotoxic BthA-I (acidic PLA2 from B. jararacussu) and other Asp49-PLA2S. BthTX-II structure showed a severe distortion of calcium-binding loop leading to displacement of the C-terminal region. Tyr28 side chain, present in this region, is in an opposite position in relation to the same residue in the catalytic activity Asp49-PLA2S, making a hydrogen bond with the atom O delta 2 of the catalytically active Asp49, which should coordinate the calcium. This high distortion may also be confirmed by the inability of BthTX-II to bind Na+ ions at the Ca2+-binding loop, despite of the crystallization to have occurred in the presence of this ion. In contrast, other Asp49-PLA2S which are able to bind Ca2+ ions are also able to bind Na+ ions at this loop. The comparison with other catalytic, non-catalytic and inhibited PLA2S indicates that the BthTX-II is not able to bind calcium ions; consequently, we suggest that its low catalytic function is based on an alternative way compared with other PLA2S.

The thermodynamic properties of the mixture of 1,1,1,2-tetrafluoroethane (R134a) and triethylene glycol dimethyl ether (TriEGDME) have been modeled with equations of state in an extended corresponding states format. A recent equation of state for pure R134a was assumed as the reference while the scale factors have been obtained in neural network form by regression of experimental data for the mixture. The modeling was focused on the liquid phase, considering the possible application of such a mixture in a refrigeration plant; since the vapor pressure of pure TriEGDME is negligible over the considered temperature range, the vapor phase of the mixture at vapor-liquid equilibrium condition is almost pure R134a. Two fundamental equations are proposed herein. The first one, developed from a limited amount of experimental data is valid for R134a mole fractions greater than 0.94. The second equation was obtained from a wider data base; it has a larger number of free parameters to regress and covers the R134a mole fractions greater than 0.59. © 2007 American Institute of Chemical Engineers AIChE J, 2007

A new modeling technique based on neural networks as a universal function approximator has been applied to study the local representation of flow boiling heat transfer at varying fluid dynamics conditions along the tube, i.e., moving through different flow pattern regions. After subdivision of the experimental data into subsets homogeneous for flow conditions, specific heat transfer equations have been heuristically got. Such specific equations have been validated and compared with the global MLFN heat transfer coefficient representation for the same target fluid as from a former work. The study has been extended to four fluids for which suitable data were available from the literature. The representation accuracies of the specialized heat transfer models are very high, even if such a method is not in general suggested due to the greater complication for both the equations development and for their practical use. It was furthermore shown that a global high accuracy flow boiling heat transfer equation can be developed also without any relation with local fluid dynamics conditions. A new modeling technique has been furthermore proposed for the fluid dynamics conditions along the tube. The linking of the picture of the actual flow condition directly with a conventional continuous real number, the so-called SF factor, allows to convert the flow condition into a numerical variable which can be turned into a continuous fluid specific function through a further MLFN technique. Limitedly to the few available literature SF data the method presents high performance and coherence for the whole SF surface. The present SF MLFN equation and the more advanced literature flow pattern model get comparable results, in spite of the limited data base. It is also shown that a flow boiling heat transfer model is not intrinsically flow pattern dependent, because a flow condition representation is never required for a global heuristic heat transfer coefficient modeling.

A new thermal conductivity equation λ=λ(T,ρ) in a multiparameter format was developed for carbon dioxide through the application of an optimization technique of the functional form. The proposed equation is valid for temperatures from the triple point (Tt=216.592K; Pt=0.51795MPa) to 1000K and pressures up to 200MPa. The calculation of density, which is an independent variable of the equation, from the experimental (T,P) conditions is performed with a high accuracy equation of state for the fluid. The thermal conductivity equation shows an average absolute deviation of 1.19% on the selected 1407 primary data points. Its performances are slightly better than those of the corresponding conventional model by Vesovic et al. [J. Phys. Chem. Ref. Data 19, 763 (1990)] available from the literature; moreover the new equation is simpler to use in particular for the near-critical region. Tables of generated values of carbon dioxide thermal conductivity are provided for check of the code implementations and for quick...

BnSP-7 and BnSP-6, two Lys49-phospholipase A2 isolated from Bothrops neuwiedi pauloensis snake venom, were co-crystallized with alpha-tocopherol and X-ray diffraction data were collected for both complexes (2.2 and 2.6 A). A new "alternative" quaternary conformation for these two complexes compared with all other dimeric Lys49-PLA2 has been observed.