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We previously reported the development of an enzyme-linked immunosorbent assay for the detection of the immunoglobulin G (IgG) response to Mycobacterium tuberculosis virulence factor - culture filtrate protein 32 (CFP32). The assay achieved high performance in comparing healthy Bacillus Calmette-Guerin-vaccinated controls with active tuberculosis (TB) patients from the Tunisian population. Herein, we aimed to assess the anti-CFP32 IgG response in suspected or confirmed active pulmonary TB individuals in different endemic settings.Serum samples were obtained from 224 donors from African and Latin American countries with variable levels of TB endemicity and different ethnical origins. Receiver operating characteristic curve was used to evaluate the performance of the serological assay.The area under the curve was 0.70. The use of a cutoff level of 0.65 gave 67% and 68% sensitivity and specificity, respectively, regardless of ethnicity and endemicity. Except for the suspected Latin American group, overall multiple comparisons of medians pointed out the stability of the anti-CFP32 IgG response across the different endemic settings. Therefore, endemicity and ethnicity seem not to affect anti-CFP32 IgG response, mainly for detecting confirmed active TB individuals.These findings suggest that the inclusion of CFP32 epitopes in multi-antigen TB assay could attenuate serological differences related to heterogeneous endemicity and ethnicity. For this purpose, we further identified B-cell epitopes belonging to CFP32 by an in silico analysis.

Objective Mesophase is a spotting fluid, along with an organic acid which will serve to remove filter cake matter, equalize differential pressure, and free the pipe. Methodology Herein is a case history of a successful application using mesophase technology for stuck pipe incident in lateral reservoir section align with wellbore cleanouts. Stuck pipe is a major operational challenge that causes a significant amount of downtime and high costs during the operation. Filter cake can significantly cause stuck pipe incidents and reduce the efficiency of the production rate of a well. This paper describes an engineered and cost-effective approach to overcome stuck pipe events. This approach is based on removing emulsions, dissolving acid soluble solids, dispersing non-solute and water wetting all surface. The mesophase restoration system is a customized, and designed to remove mud damage, in-situ emulsions, oil-based mud (OBM) filter cakes in the well bores. Results Selection of an appropriate clean-up procedure is critical in ensuring the productivity of open hole wells, particularly horizontal wells. The mesophase system was pumped ahead after pumping the spacer train. The system contains a proprietary surfactant blend, organic acid, corrosion inhibitor, and brine that are all spotted into the stuck spot in the hole and allowed to soak. During this soaking process, the ultra-low interfacial tension properties of the breaker solution begin to diffuse, solubilizing the oil in the emulsions and dissolving the filter cake while dispersing undissolved solids and allowing the pipe to be freed. Novelty The success of freeing a stuck-pipe depends on two main factors – the correct diagnosis of stuck-pipe event either to be differential or mechanical stuck, and the right decision to implement the remedial treatment quickly and effectively. Applying the mesophase fluid technique saved the non- productive time (NPT). This technique is a reservoir friendly and has been successfully implemented in stuck-pipe events in oil-based drilling fluids.

Background and study aim: Recently, multiple regimens of different direct-acting antiviral agents (DAAs) have been emerged. We aimed to assess the efficacy, safety and improvement of liver profile for patients treated with regimens of direct acting-antivirals in Egypt. Patients and Methods: A retrospective observational study was conducted at Suez governorate, including a simple random sample of 76 patients treated with directly-acting antiviral therapy and came to our center to enroll our follow up program after antiviral therapy from November 2015 to May 2016. Sustained viral response (SVR) was established at week 12 after end of treatment. Results: A total of 76 chronic hepatitis C patients initiated treatment with DAAs. Forty patients (52.6%) were treated with triple therapy and thirty-six patients (47.3%) with dual therapy. All patients were treated for 12 weeks. According to Intention to treat analysis, 35 of 40 patients (87%) who treated with triple therapy achieved SVR while 32 of 36 patients (88.9%) treated with dual therapy achieved SVR. However, the difference between responders after both regimens wasn’t statistically significant (p= 1). In the group treated with triple therapy, significantly more patients had anemia, leukopenia and thrombocytopenia with no serious side effects leading to discontinuation of therapy. Conclusion: Both regimens had similar efficacy, but the dual therapy was more tolerated with less side effect profile.

Background and study aim: Anti-hepatitis B core (anti-HBc) sero-positivity in general population in Egypt is reported to be 10-13%. This study was performed to determine the prevalence of anti-HBc among chronic hepatitis C patients before antiviral therapy. Patients and Methods: A total of 178 consenting patients with chronic HCV infection eligible for treatment with DAAs according to program of National Committee for Control of Hepatitis Infection in Portsaid, Egypt from April to October 2017. All of the patients were screened for anti-HBs and anti-HBc. Anti-HBc–positive patients were assayed for HBV DNA. Results: Out of 178 chronic hepatitis C patients, Eighty four patients (47.2%) were treated with triple therapy (Sofosbuvir/ Daclatasvir/Ribavirin) and ninety four patients (52.8%) with dual therapy (Sofosbuvir/Daclatasvir). A65 patients (36.5%) werereactive for anti-HBc. Of 84 patients, 34 (40.5%) who treated with triple therapy were reactive for anti-HBc. Of 94 patients, 31 (33%) who treated with dual therapy were reactive for it. All patients were negative for anti-HBs and anti-HBc–positive patients were no detected HBV DNA at baseline and 12 weeks after DAAs. Conclusion: Our results suggest including anti-HBc as an additional screening test for chronic hepatitis C patient in Egypt who are eligible for DAAs to reduce the risk of HBV reactivation and fulminant hepatitis after DAAs.

Objective To validate the feasibility and tolerance of an intensive rehabilitation protocol initiated during the postoperative period in an intensive care unit (ICU) in liver transplant recipients. Design Prospective randomized study. Setting ICU. Participants Liver transplant recipients over a period of 1 year (N=40). Interventions The "usual treatment group" (n=20), which benefited from the usual treatment applied in the ICU (based on physician prescription for the physiotherapist, with one session a day), and the experimental group (n=20), which followed a protocol of early and intensive rehabilitation (based on a written protocol validated by physicians and an evaluation by physiotherapist, with 2 sessions a day), were compared. Main Outcome Measures Our primary aims were tolerance, assessed from the number of adverse events during rehabilitation sessions, and feasibility, assessed from the number of sessions discontinued. Results The results revealed a small percentage of adverse events (1.5% in the usual treatment group vs 1.06% in the experimental group) that were considered to be of low intensity. Patients in the experimental group sat on the edge of their beds sooner (2.6 vs 9.7d; P =.048) and their intestinal transit resumed earlier (5.6 vs 3.7d; P =.015) than patients in the usual treatment group. There was no significant difference between the 2 arms regarding length of stay (LOS), despite a decrease in duration in the experimental group. Conclusions The introduction of an intensive early rehabilitation program for liver transplant recipients was well tolerated and feasible in the ICU. We noted that the different activities proposed were introduced sooner in the experimental group. Moreover, there is a tendency to decreased LOS in the ICU for the experimental group. These results now need to be confirmed by studies on a larger scale.

Dye-sensitized solar cell (DSSC) constitutes a real revolution in the conversion of solar energy into electricity after 40 years of the invention of silicon solar cells. The working mechanism is based on a photoelectrochemical system, similar to the photosynthesis in plant leaves. The efficiencies of the DSSC are high as those obtained from amorphous silicon solar cells (10-11 %) and intensive efforts are done in different directions to improve this efficiency.

This study focused on the evaluation of cellulolytic and hemicellulolytic fungi isolated from sawdust compost (SDC) and coffee residue compost (CRC). To identify fungal isolates, the ITS region of fungal rRNA was amplified and sequenced. To evaluate enzyme production, isolates were inoculated onto wheat bran agar plates, and enzymes were extracted and tested for cellulase, xylanase, β-glucanase, mannanase, and protease activities using different azurine cross-linked (AZCL) substrates. In total, 18 isolates from SDC and 29 isolates from CRC were identified and evaluated. Four genera (Aspergillus, Galactomyces, Mucor, and Penicillium) and five genera (Aspergillus, Coniochaeta, Fusarium, Penicillium, and Trichoderma/Hypocrea) were dominant in SDC and CRC, respectively. Penicillium sp., Trichoderma sp., and Aspergillus sp. displayed high cellulolytic and hemicellulolytic activities, while Mucor isolates exhibited the highest β-glucanase and mannanase activities. The enzyme analyses revealed that Penicillium, Aspergillus, and Mucor isolates significantly contributed to the degradation of SDC, whereas Penicillium, Aspergillus, and Trichoderma isolates had a dominant role in the degradation of CRC. Notably, isolates SDCF5 (P. crustosum), CRCF6 (P. verruculosum), and CRCF2 and CRCF16 (T. harzianum/H. lixii) displayed high activity regarding cellulose and hemicellulose degradation, which indicates that these species could be beneficial for the improvement of biodegradation processes involving lignocellulosic materials.

A new antimicrobial peptide, referred to as MMFII, was purified to homogeneity from lactic acid bacteria Lactococcus lactis, which were isolated from Tunisian dairy product. The complete amino acid sequence of the peptide has been established by amino acid analysis, Edman sequencing, and mass spectrometry and verified by solid-phase chemical synthesis. MMFII is a single-chain 37-residue polypeptide containing a single intramolecular disulfide bond, i.e., TSYGNGVHCNKSKCWIDVSELETYKAGTVSNPKDILW. It shares ca. 35% sequence identity with Leucocin A, a class IIa bacteriocin. Modeling based on the 3-D of Leucocin A shows three beta strands located in the N-terminal region (Thr1-Tyr3, Val7-Asn10, Lys13-Ile16) and an alpha helical domain from Asp17 to Asn31. When plotted as an alpha-helical wheel, the central alpha-helix of MMFII does not exhibit an amphipathic helical structure. The synthetic MMFII (sMMFII), obtained by the solid-phase method, was shown to be indistinguishable from the natural peptide. sMMFII is active against Lactococcus cremoris and Listeria ivanovii bacteria, whereas no activity was detected for any of the synthetic N-terminal truncated MMFII analogs Cys9-Trp37, Trp15-Trp37, and Val18-Trp37.

Maurotoxin (MTX) is a 34-residue toxin that has been isolated from the venom of the chactidae scorpion Scorpio maurus palmatus, and characterized. Together with Pi1 and HsTx1, MTX belongs to a family of short-chain four-disulfide- bridged scorpion toxins acting on potassium channels. However, contrary to other members of this family, MTX exhibits an uncommon disulfide bridge organization of the type C1^C5, C2^ C6, C3^C4 and C7^C8, versus C1^C5, C2^C6, C3^C7 and C4^ C8 for both Pi1 and HsTx1. Here, we report that the substitution of MTX proline residues located at positions 12 and/or 20, adjacent to C3 (Cys13) and C4 (Cys19), results in conventional Pi1- and HsTx1-like arrangement of the half-cystine pairings. In this case, this novel disulfide bridge arrangement is without obvious incidence on the overall three-dimensional structure of the toxin. Pharmacological assays of this structural analog, (A12,A20)MTX, reveal that the blocking activities on Shaker B and rat Kv1.2 channels remain potent whereas the peptide becomes inactive on rat Kv1.3. These data indicate, for the first time, that discrete point mutations in MTX can result in a marked reorganization of the half-cystine pairings, accompanied with a novel pharmacological profile for the analog. fl 2001 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.

Maurotoxin (MTX) is a scorpion toxin acting on several K+ channel subtypes. It is a 34-residue peptide cross-linked by four disulfide bridges that are in an “uncommon” arrangement of the type C1-C5, C2-C6, C3-C4, and C7-C8 (versus C1-C5, C2-C6, C3-C7, and C4-C8 for Pi1 or HsTx1, two MTX-related scorpion toxins). We report here that a single mutation in MTX, in either position 15 or 33, resulted in a shift from the MTX toward the Pi1/HsTx1 disulfide bridge pattern. This shift is accompanied by structural and pharmacological changes of the peptide without altering the general α/β scaffold of scorpion toxins.

Mouse embryonic stem (ES) cells in culture can differentiate into late stages of many lineage-committed precursors. Under appropriate organ culture conditions, ES cells differentiate into lymphoid-like cells at an embryonic stage equivalent to day 10–14. These hematopoietic precursors are located in cup-shaped structures found in some embryoid bodies; we called such embryoid bodies "ES fetuses." We have followed the maturation of hematopoietic cells after implantation of ES fetuses into nude mice and SCID mice for 3 weeks. Nude mice seem to be better hosts than SCID mice for maturation of lymphoid cells. In chimeric nude mice, mature CD4+ and CD8+ T cells were found in the spleen. As nude mice lack a thymus, these T cells might have been educated by thymus-like epithelium generated from ES fetuses endogenously. Here we report finding organized epithelial structures resembling thymic cortex and medulla in the implanted ES fetuses. Using immunofluorescence and peroxidase staining, with flow cytometry, light...

The dipole moments of the title diketones have been measured and compared with the values calculated by MM2. Both sets of values are in good agreement. The diketones exist (74–94%) in pairs of enantiomeric conformations with angles between both carbonyl dipoles in the range 62–66°.

Molecular mechanics calculations with the latest available version of Allinger's MM2 force field (MM2(91)) on the diastereomeric complexes of both enantiomeric conformations ofcis-decalin with β-cyclodextrin show a small preference (1.67 kJ mol−1) for one of them, in agreement with the available13C-NMR results. Calculations were found to be sensitive to the procedure used.

Maurotoxin (MTX) is a 34-residue toxin that was isolated initially from the venom of the scorpion Scorpio maurus palmatus. Unlike the other toxins of the α-KTx6 family (Pi1, Pi4, Pi7, and HsTx1), MTX exhibits a unique disulfide bridge organization of the type C(1) C(5) , C(2) C(6) , C(3) C(4) , and C(7) C(8) (instead of the conventional C(1) C(5) , C(2) C(6) , C(3) C(7) , and C(4) C(8) , herein referred to as Pi1-like) that does not prevent its folding along the classic α/β scaffold of scorpion toxins. MTX(Pi1) is an MTX variant with a conventional pattern of disulfide bridging without any primary structure alteration of the toxin. Here, using MTX and/or MTX(Pi1) as models, we investigated how the type of folding influences toxin recognition of the Shaker B potassium channel. Amino acid residues of MTX that were studied for Shaker B recognition were selected on the basis of their homologous position in charybdotoxin, a three disulfide-bridged scorpion toxin also active on this channel type. These residues favored either an MTX- or MTX(Pi1) -like folding. Our data indicate clearly that Lys(23) and Tyr(32) (two out of ten amino acid residues studied) are the most important residues for Shaker B channel blockage by MTX. For activity on SKCa channels, the same amino acid residues also affect, directly or indirectly, the recognition of SK channels. The molecular modeling technique and computed docking indicate the existence of a correlation between the half cystine pairings of the mutated analogs and their activity on the Shaker B K(+) channel. Overall, mutations in MTX could, or could not, change the reorganization of disulfide bridges of this molecule without affecting its α/β scaffold. However, changing of the peptide backbone (cross linking disulfide bridges from MTX-like type vs MTX(Pi1) -like type) appears to have less impact on the molecule activity than mutation of certain key amino acids such as Lys(23) and Tyr(32) in this toxin.

In order to evaluate medical management in patients with renal failure before dialysis, we conducted a case-control study to analyze the health benefits in 914 moderate renal failure patients with Cockcroft clearance between 30 and 60 ml/min. Health benefits reimbursed by the Social Security in this population were compared with those in 1828 controls randomly chosen in the Social Security files but matched by age and gender. Mean age of the participants was 73+/-11 year-old, 67% were women, Cockcroft clearance was 48+/-8 ml/min. Number of hospitalizations and hospitalization durations were not different between the two populations. Conversely, cases had more specialized outpatients' clinics in cardiology but not in nephrology or urology. Cases had more biological tests and radiological exams and had taken more medicines. For biology, cases had more often renal function tests and markers of renal dysfunction tests than controls. Cases had taken more medicines than controls for erythropoietin, diuretics, renin-angiotensin blockers, hypoglycemic drugs, and anticoagulants. Patients with mild renal failure had higher health benefits than controls for outpatients' clinics in cardiology, for biological tests, for radiological exams, and for some medicines.

Leukocyte adhesion deficiency (LAD) is a rare primary immunodeficiency inherited as an autosomal recessive genetic disorder. LAD was suspected in a four days old girl. She was born from healthy first cousins. A family history of a boy who died from omphalitis and sepsis was reported. Our patient had the severe form, she had delayed umbilical cord separation and suffered recurrent infections. She had a deletion of the G at position 1497. The patient received bone marrow transplantation from her HLA-identical mother at age of 14 months. She is now 9 years old and in good health.

We have modelled the conformation of the III-IV loop of the Ca(v)2.1 subunit of P/Q calcium channels, a loop that is implicated in fast voltage-dependent inactivation. Change in channel inactivation requires its direct interaction with the I-II loop. This interaction occurs with an affinity in the order of 70 nm. Intracellular injection of a 40-mer III-IV loop-derived peptide produces an increase in the rate of fast inactivation. This alteration in channel kinetic is also accompanied by a hyperpolarizing shift in the steady-state voltage-dependence of inactivation. None of these effects are observed in the presence of a beta subunit, suggesting the existence of a competitive mechanism of action between the beta subunit and the III-IV loop. Amino acid sequence comparison using BLAST reveals that the III-IV loop shares 53% identity with the gamma subunit of G proteins. Because of the pivotal contribution of the III-IV loop to inactivation, an atomic model of the III-IV loop was generated by both homology modelling and molecular mechanics calculations. Using the X-ray structures of the betagamma dimer of the heterotrimeric G-proteins as templates, the III-IV loop is predicted to contain a well-structured alpha-helix at the amino-terminus with both the N- and C-termini having the same orientation in the plane of the inner lipid bilayer. We provide a hypothetical working model in which we propose that the III-IV loop interacts with the I-II loop via its Gbetagamma binding domain.

Lebetins from Macrovipera lebetina snake venom constitute a new class of inhibitors of platelet aggregation. There are two groups of peptides: lebetin 1 (L1; 11- to 13-mer) and lebetin 2 (L2; 37- to 38-mer). The short lebetins are identical to the N-terminal segments of the longer ones. They inhibit platelet aggregation induced by various agonists (e.g. thrombin, PAF-acether or collagen). The shortest lebetin (11-mer) shows potent inhibition of rabbit (IC50 = 7 nM) and human (IC50 = 5 nM) platelets. They prevent collagen-induced thrombocytopenia in rats. N- and C-terminal-truncated synthetic L1γ (sL1γ; 11-mer) is less active in inhibiting platelet aggregation than the native peptide. Results from Ala scan studies of the sL1γ peptide indicated that replacement of the residues (P3, G7, P8, P9 or N10) resulted in a remarkable drop in the activity, whereas replacement of residues K2, P4 or K6 by Ala resulted in enhancement of the antiplatelet activity by at least 10-fold. To examine the activity of multimeric L1γ, several multimeric peptides were synthesized using the multiple-antigen peptide system assembled on a branched lysine core and their antiplatelet activity was evaluated in vitro. The largest multimeric peptides showed a 1,000-fold increase in antiplatelet activity.

Maurotoxin (MTX) is a 34-mer scorpion toxin cross-linked by four disulfide bridges that acts on both Ca(2+)-activated (SK) and voltage-gated (Kv) K(+) channels. A 38-mer chimera of MTX, Tsk-MTX, has been synthesized by the solid-phase method. It encompasses residues from 1 to 6 of Tsk at N-terminal, and residues from 3 to 34 of MTX at C-terminal. As established by enzyme cleavage, Tsk-MTX displays half-cystine pairings of the type C1-C5, C2-C6, C3-C7 and C4-C8 which, contrary to MTX, correspond to a disulfide bridge pattern common to known scorpion toxins. The 3-D structure of Tsk-MTX, solved by (1)H NMR, demonstrates that it adopts the alpha/beta scaffold of scorpion toxins. In vivo, Tsk-MTX is lethal by intracerebroventricular injection in mice (LD(50) value of 0.2 microg/mouse). In vitro, Tsk-MTX is as potent as MTX, or Tsk, to interact with apamin-sensitive SK channels of rat brain synaptosomes (IC(50) value of 2.5 nM). It also blocks voltage-gated K(+) channels expressed in Xenopus oocytes, but is inactive on rat Kv1.3 contrary to MTX.

Maurotoxin (MTX) is a 34-mer scorpion toxin cross-linked by four disulphide bridges that acts on various K+ channel subtypes. MTX adopts a disulphide bridge organization of the type C1–C5, C2–C6, C3–C4 and C7–C8, and folds according to the common α/β scaffold reported for other known scorpion toxins. Here we have investigated the process and kinetics of the in vitro oxidation/folding of reduced synthetic L-MTX (L-sMTX, where L-MTX contains only l-amino acid residues). During the oxidation/folding of reduced L-sMTX, the oxidation intermediates were blocked by iodoacetamide alkylation of free cysteine residues, and analysed by MS. The L-sMTX intermediates appeared sequentially over time from the least (intermediates with one disulphide bridge) to the most oxidized species (native-like, four-disulphide-bridged L-sMTX). The mathematical formulation of the diffusion-collision model being inadequate to accurately describe the kinetics of oxidation/folding of L-sMTX, we have formulated a derived mathematical description that better fits the experimental data. Using this mathematical description, we have compared for the first time the oxidation/folding of L-sMTX with that of D-sMTX, its stereoisomer that contains only d-amino acid residues. Several experimental parameters, likely to affect the oxidation/folding process, were studied further; these included temperature, pH, ionic strength, redox potential and concentration of reduced toxin. We also assessed the effects of some cellular enzymes, peptidylprolyl cis–trans isomerase (PPIase) and protein disulphide isomerase (PDI), on the folding pathways of reduced L-sMTX and D-sMTX. All the parameters tested affect the oxidative folding of sMTX, and the kinetics of this process were indistinguishable for L-sMTX and D-sMTX, except when stereospecific enzymes were used. The most efficient conditions were found to be: 50mM Tris/HCl/1.4mM EDTA, pH7.5, supplemented by 0.5mM PPIase and 50units/ml PDI for 0.1mM reduced compound. These data represent the first report of potent stereoselective effects of cellular enzymes on the oxidation/folding of a scorpion toxin.

Maurotoxin (MTX) is a 34-residue toxin that has been isolated from the venom of the chactidae scorpion Scorpio maurus palmatus. The toxin displays an exceptionally wide range of pharmacological activity since it binds onto small conductance Ca(2+)-activated K(+) channels and also blocks Kv channels (Shaker, Kv1.2 and Kv1.3). MTX possesses 53-68% sequence identity with HsTx1 and Pi1, two other K(+) channel short chain scorpion toxins cross-linked by four disulfide bridges. These three toxins differ from other K(+)/Cl(-)/Na(+) channel scorpion toxins cross-linked by either three or four disulfide bridges by the presence of an extra half-cystine residue in the middle of a consensus sequence generally associated with the formation of an alpha/beta scaffold (an alpha-helix connected to an antiparallel beta-sheet by two disulfide bridges). Because MTX exhibits an uncommon disulfide bridge organization among known scorpion toxins (C1-C5, C2-C6, C3-C4, and C7-C8 instead of C1-C4, C2-C5, and C3-C6 for three-disulfide-bridged toxins or C1-C5, C2-C6, C3-C7, and C4-C8 for four-disulfide-bridged toxins), we designed and chemically synthesized an MTX analog with three instead of four disulfide bridges ([Abu(19),Abu(34)]MTX) and in which the entire consensus motif of scorpion toxins was restored by the substitution of the two half-cystines in positions 19 and 34 (corresponding to C4 and C8) by two isosteric alpha-aminobutyrate (Abu) derivatives. The three-dimensional structure of [Abu(19), Abu(34)]MTX in solution was solved by (1)H NMR. This analog adopts the alpha/beta scaffold with now conventional half-cystine pairings connecting C1-C5, C2-C6, and C3-C7 (with C4 and C8 replaced by Abu derivatives). This novel arrangement in half-cystine pairings that concerns the last disulfide bridge results mainly in a reorientation of the alpha-helix regarding the beta-sheet structure. In vivo, [Abu(19),Abu(34)]MTX remains lethal in mice as assessed by intracerebroventricular injection of the peptide (LD(50) value of 0. 25 microg/mouse). The structural variations are also accompanied by changes in the pharmacological selectivity of the peptide, suggesting that the organization pattern of disulfide bridges should affect the three-dimensional presentation of certain key residues critical to the blockage of K(+) channel subtypes.