Optimization of antibody fragment production in Bacillus megaterium: the role of metal ions on protein secretion

The effect of the concentration of metal ions in minimal media has been shown to be very important for the production and secretion of the antibody fragment D1.3 scFv in Bacillus megaterium YYBm1. The best media compositions for biomass and antibody fragment formation were evaluated using a genetic algorithm. The screening was carried out in 96 microtiter deep well plates with 900 μL cultivation volume. In 7 generations, 240 different kinds of media were tested, key elements for production and secretion were detected and a 117% increase in production of antibody fragment compared to the previously used medium could be achieved. In addition, media with a higher biomass formation (+84%) or with both more biomass and a higher production of antibody fragment (Pareto-front members) were found. Interestingly the best media for protein production and secretion were different in their composition, with regards to the metal ion concentration levels. From data derived experimentally and from the genome, magnesium was shown to be one of the key components of the metal ions tested for biomass formation and especially for production and secretion of the antibody fragment D1.3 scFv.

Branchial remnant cysts of mature and juvenile horses

This clinical report describes 8 cases of branchial remnant cysts (BRC) in the horse. The horses presented with bimodal age distribution, with 5 cases in mature horses (age 8-21 years) and 3 in foals (age 1, 6 and 10 months). Mature cases presented for dysphagia or intermittent oesophageal obstruction (2/5), and retropharyngeal swelling (3/5), whereas respiratory stridor and visible mass were presenting complaints in the foals. Presence of a right-sided (5/8) or dorsally located (2/8) palpable retropharyngeal mass of 3-35 cm diameter was noted clinically; one left-sided mass was identified as an incidental finding at necropsy. Ultrasonography typically revealed a thick-walled cyst containing hypoechoic fluid with dependent hyperechoic masses consistent with blood clots. Radiographs and upper airway endoscopy were also consistent with a retropharyngeal mass. Fluid cytology revealed chronic haemorrhage in 6/8 cases, and squamous epithelial cells in one case. Histopathology in all cases demonstrated an epithelium-lined cyst with no smooth muscle or thyroid tissue. Two cases was subjected to euthanasia; one due to concurrent laryngeal anomalies and one due to financial constraints. The remaining 5 cases were treated via surgical excision. Post operatively, right laryngeal hemiplegia was observed in 4/5 cases. All previous reports of BRC in the horse have described juvenile individuals. Brachial remnant cyst should be considered a differential diagnosis for mature horses with masses of the throatlatch area and can be definitively diagnosed by the presence of squamous epithelium in aspirated fluid or by histopathology of the excised mass. Right recurrent laryngeal nerve damage is a common complication of surgery.

Electrochemical dissolution of simulated "white inclusions" in nitric acid. Linear voltammetry study with Mo, Re, Ru metals and their alloys electrodes

The process of electrochemical dissolution of pure Mo, Re and Ru metals, as well as their alloys 52.5 at. Mo – 47.5 at. Re and 90 at. Mo – 10 at. Ru in 0.5-6.0M HNO3 was studied using the linear voltammetry technique. The dissolution potentials of the pure metals were found to increase from 0.39 to 0.48V/SCE (Mo), from 0.7 to 0.81V/SCE (Re) and from 1.15 to 1.25V/SCE (Ru) with the augmentation of HNO3 concentration in the electrolyte. The dissolution potentials of the alloys 52.5 at. Mo + 47.5 at. Re and 90 at. Mo + 10 at. Ru were found to change from 0.49 to 0.58 (Mo-Re) and from 0.92 to 1.09 (Mo-Ru) when HNO3 concentration in the electrolyte increased from 0.5 to 6.0M. The secondary passivation of Mo-containing electrodes was observed in the solutions 2.0-6.0M HNO3 at the potentials from 1.4 to 1.9V/SCE, decreasing their dissolution rate in this range of potentials. The maximum electrochemical dissolution rate constants of pure Mo, Re, Ru metals and Mo-Re, Mo-Ru alloys have been estimated using the data of linear voltammetry. The obtained values (1.85-2.20g/cm2 h for Mo-Re and 0.58-0.64g/cm2 h for Mo-Ru alloys electrochemical dissolution) are found to be thousand times greater, than reported for the process of chemical dissolution of corresponding alloys in boiling HNO3.

Polymorph stability and phase transitions of trigonal Al1- x Ga x PO4 mixed crystals

Single crystals of Al1- x Ga x PO4 of various mole fractions x were grown from phosphoric acid solutions under hydrothermal conditions using the slow-heating method. In order to relate the parameters of this low-quartz structure analogue and the observed phase transitions to the respective mole fraction, the crystals were investigated by means of electron probe microanalysis, X-ray powder diffraction and differential thermal analysis. The results are discussed in terms of the segregation effects occuring during growth. The limiting geometrical parameters for the existence of the high-quartz phase are compared to the values given in the literature.

Differential pulse voltammetric determination of U(VI)-Tc(VII) and U(VI)-Cr(VI) in alkaline solutions

Differential pulse voltammetric (DPV) technique has been developed for the simultaneous determination of the elements in Tc(VII)-U(VI) and U(VI)-Cr(VI) mixtures in alkaline solutions. The method gave a precision of about 14% to 2% in the range of 1×10-7--1×10-4 for Cr(VI) and Tc(VII) and 1×10-6--1×10-4 for U(VI). The detection limits are 8×10-8 mol l-1 for Tc(VII) and 3×-7 mol l-1 for Cr(VI), and 8×10-7 for U(VI). It has been established that Tc(VII) could be determined in the presence of about 350 excess fold U(VI). The reduction of Tc(VII) with hydrazine has been suggested to eliminate the effect of Tc(VII) ions on the U(VI) determination. U(VI) has been determined in the presence of Cr(VI) up to molar concentration ratio U(VI)/Cr(VI)=1:1, while Cr(VI) could be determined in the presence of U(VI) in the solutions with up to molar concentration ratio Cr(VI)/U(VI)=1:15. The reliability of the determination of the elements of Tc(VII)-U(VI) and U(VI)-Cr(VI) mixtures in alkaline solution has been tested by a standard addition method.

Electrochemical dissolution of simulated "white inclusions". Kinetics and material balance for Mo, Re, Ru metals and their alloys during electrochemical dissolution in nitric acid

The kinetics of pure Mo, Re and Ru metals, as well as their alloys 52.5at. Mo – 47.5at. Re and 90at. Mo – 10at. Ru electrochemical dissolution during potential controlled electrolysis at a temperature T=25 °C in 0.5–6.0M HNO3 solutions were studied. The dissolution kinetics for all metal and alloy electrodes under study were found to be of zero order vs. metal concentration in the electrolyte. Rate constants for Mo electrochemical dissolution increased from 1.68×10-3 to 5.99×10-3mol cm-2h-1 with the growth of HNO3 concentration in the electrolyte from 0.5 to 4.0M. Further increase of the acid concentration in the solution to 6.0M did not result in the acceleration of Mo electrochemical dissolution. Rate constants of Re and Ru metals electrochemical dissolution increased monotonously from 4.27×10-4 to 1.7×10-3mol cm-2 h-1 for Re and from 1.28×10-4 to 1.61×10-3mol cm-2 h-1 for Ru with the rise of HNO3 concentration from 0.5 to 6.0M. Dissolution of Mo-Re and Mo-Ru alloys was congruent. With the increase of HNO3 concentration in the electrolyte from 0.5 to 6.0M, the dissolution rate constant of Mo-Re alloy was increasing from 1.33 to 7.60×10-3mol(Mo+Re)cm-2h-1. Maximum rates of Mo-Ru alloy electrochemical dissolution from 2.21×10-3 to 3.28×10-3mol(Mo+Ru)cm-2 h-1 were observed in 2.0–4.0M HNO3 at the electrolysis potential E=1.6V/SCE. The main electrochemical and chemical processes occurring at the metal and alloy electrodes and resulting in the metals dissolution are pointed out.

Determination of Mo(VI), Ru(III), Re(VII) and NO3 - in the solutions of nuclear fuel cycle by capillary electrophoresis

A method for simultaneous quantitative determination of Mo(VI), Re(VII), Ru(III) and NO3 - ions in aqueous solutions, using capillary zone electrophoresis (CZE) technique with direct UV detection, was developed. Electrophoretic mobility of Ru(III) ions in 0.1M NaHCO3 solution was determined as 6.0×10-8m2 V-1 s-1 at 25 °C. The best analytical characteristics of the developed method were achieved with a 100mM carbonate buffer solution containing 0.3mM TTAB, at a pH value of 9.8 and at an applied voltage of 10kV. Under these conditions, a linear relationship between the measured absorbance (λ=230nm) and the concentration of the species under study were observed in the range 5×10-6–10-3M for Mo(VI), 7×10-6–10-3M for Re(VII) and 10-5–-4M for Ru(III). The minimum detectable concentrations were determined as 4.1×10-6M for NO3 -, 5.2×10-6M for Mo(VI), 7.4×10-6M for Re(VII) and 1.0×10-5M for Ru(III). The accuracy of quantitative determination was estimated as 3%–5% for NO3 - and 5%–6% for Mo(VI), Re(VII) and Ru(III) ions. The presence of 0.06M NaNO3 (HNO3) and of 10-3M U(VI) in the sample affected neither the detection limits of the species under study nor the selectivity of the method.

Effects of a MAPK p38 inhibitor on lung function and airway inflammation in equine recurrent airway obstruction

REASONS FOR PERFORMING STUDY

It has been suggested that many of the beneficial effects of corticosteroids are mediated through mitogen-activated protein kinase (MAPK) p38 inhibition.

OBJECTIVE

To investigate the efficacy of the MAPK p38 inhibitor compound MRL-EQ1 to either prevent (Phase 1) or treat (Phase 2) recurrent airway obstruction (RAO) in horses.

METHODS

MRL-EQ1 was administered i.v. at a dosage of 0.75-1.5 mg/kg bwt q. 12 h. In Phase 1, susceptible horses in clinical remission were divided into 2 groups (n = 5/group), based on historical values of respiratory mechanics. All horses were entered in the study in pairs (one control, one treated horse) and exposed to the same environmental challenge (stabling, mouldy hay and dusty conditions). The treatment group received MRL-EQ1 for 14 days while the control horses were untreated during the same period. In Phase 2, affected horses were ranked by severity of respiratory dysfunction and split randomly into either dexamethasone or MRL-EQ1 treatment groups (n = 5/group). Bronchoalveolar lavage fluid, respiratory mechanic measurements, MRL-EQ1 plasma concentration and tumour necrosis factor (TNF) whole blood activity were evaluated sequentially.

RESULTS

In Phase 1, MRL-EQ1 did not prevent the occurrence of clinical signs and pulmonary inflammation. However, treatment was associated with a reduction in severity and a delay in the onset of signs and a reduction in pulmonary neutrophilia. In Phase 2, plasma concentrations achieved resulted in ex vivo suppression of lipopolysaccharide-induced TNF production in equine blood. MRL-EQ1 did not improve airway inflammation or lung function and was associated in a dose dependent manner with behavioural (depression, excitability) and blood changes (neutrophilia, increased serum muscle enzyme concentrations).

CONCLUSIONS

Inhibition of p38 in the horse was partially effective in reducing clinical signs and airway inflammation when administered prior to, but not during clinical exacerbation in RAO.

POTENTIAL RELEVANCE

Inhibitors of p38 MAPK with a better toxicity profile may be effective in the prevention or treatment of RAO.

Clinical and financial analysis of an acute palliative care unit in an oncological department

The aim of this article is to describe the clinical activity and medical intervention of an acute model of palliative care unit (APC), as well as the reimbursement procedures and economic viability. A sample of 504 patients admitted at an APC in 1 year was surveyed. Indications for admission, pain and symptom intensity, analgesic treatments, procedures, instrumental examinations and modalities of discharge were recorded. For each patient, tariff for reimbursement was calculated according to the existent disease related grouping (DRG) system. The mean age was 62 years, and 246 patients were males. The mean hospital stay was 5.4 days. Pain control was the most frequent indication for admission. All patients had laboratory tests and several instrumental examinations. Almost all patients were prescribed one or more opioids at significant doses, and different routes of administration, as well as medication as needed. 59 patients received blood cell transfusions and 34 interventional procedures. Only 40 patients died in the unit, 11 of them being sedated at the end of life. Treatment efficacy was considered optimal and mild in 264 and 226 patients respectively. A mean of 3019 euros for admission was reimbursed by the Health Care System. APCs are of paramount importance within an oncological department, as they provide effective and intensive treatments during the entire course of disease, providing a simultaneous and integrated approach. Our findings also suggest both a cost and quality incentive for oncological departments to develop APC.

Systematic field theory of the RNA glass transition

We prove that the Lässig-Wiese (LW) field theory for the freezing transition of the secondary structure of random RNA is renormalizable to all orders in perturbation theory. The proof relies on a formulation of the model in terms of random walks and on the use of the multilocal operator product expansion. Renormalizability allows us to work in the simpler scheme of open polymers, and to obtain the critical exponents at 2-loop order. It also allows us to prove some exact exponent identities, conjectured by LW.

Ultrasound-guided coxofemoral arthrocentesis in horses

REASON FOR PERFORMING STUDY

Coxofemoral joint pain is probably underestimated due to difficulties in identifying hip pain. The deep location of the joint and proximity of the sciatic nerve make arthrocentesis based on external landmarks a difficult and potentially risky procedure in mature horses.

OBJECTIVES

To describe an ultrasound-guided injection technique of the coxofemoral joint in standing horses and to evaluate its accuracy and potential difficulties/complications.

METHODS

Nine mature horses had both pelvic areas prepared for sterile ultrasound examination (3.5 MHz curvilinear probe). Coxofemoral joints were located and penetrated at their craniodorsolateral aspect under ultrasonographic guidance and injected with sterile contrast medium. A standing ventrodorsal radiographic view of each hemipelvis centred on the hip was obtained for each horse to assess the injection site. Horses were evaluated for 10 days following injection for possible complications.

RESULTS

Intra-articular injection was successful in all 18 joints. The procedure was well tolerated by horses under minimal restraint. Mean +/- s.d. needle repositionings required before accurate placement was 1.5 +/- 1.3 per joint. Once the needle was in the joint, synovial fluid was obtained in 7/18 joints. Minimal periarticular contrast medium was detected in 2/18 joints. Mean +/- s.d. ultrasonographic examination time required for coxofemoral localisation, accurate needle positioning and injection was 4.3 +/- 2.1 min. No complications were observed in the 10 days following injection.

CONCLUSION

The ultrasound-guided coxofemoral arthrocentesis is an accurate, reliable and safe technique that offers a real time evaluation of needle introduction into the deep and narrow coxofemoral joint space.

POTENTIAL RELEVANCE

Although this technique remains to be tested on clinical cases, it is a promising tool to facilitate diagnosis of coxofemoral pain, septic arthritis or administration of intra-articular medication.

Studies of uptake, elimination, and late effects in Atlantic salmon (Salmo salar) dietary exposed to Di-2-ethylhexyl phthalate (DEHP) during early life

The phthalate esters are a group of industrial chemicals considered to have endocrine-disrupting properties. The most common tonnage product among these, di-2-ethylhexyl phthalate (DEHP), is widely spread in the environment. The objectives with the present work were to study uptake and metabolism of orally administered DEHP and its major metabolite mono-2-ethyl hexyl phthalate (MEHP) and to evaluate the impact of early life exposure on sex differentiation in Atlantic salmon. The feeding with contaminated diet started immediately after yolk sac resorption and continued for 4 weeks. Nominal concentrations of DEHP in the diet were 400 (measured 359), 800 (measured 827), and 1500 (measured 1648) mg DEHP/kg and a control group was fed food mixed with solvent. After the exposure period, fish were fed non-contaminated diet until final sampling 4 months post-exposure. There were no effects on growth or survival of the fish and no late effects on hepatosomatic index or sex ratio. However, the histological examination of gonads from fish exposed to 1500 mg DEHP/kg revealed a small but significant incidence (3%) of intersex fish (ovo-testis). Chemical residues of DEHP and MEHP were analyzed weekly during the first 3 months of the post-exposure period. Both DEHP and MEHP were rapidly eliminated to near background levels within one week post exposure. The study indicates that exposure of Atlantic salmon to relatively high concentrations of DEHP during a sensitive part of the life cycle may interfere with gonad differentiation.

Application of an in-line imprinted polymer column in a potentiometric flow-injection chemical sensor to the determination of the carbamate pesticide carbaryl in complex biological matrices

A flow-injection biosensor-like system based on a nonenzymatic approach has been developed to determine the carbamate pesticide carbaryl in complex biological samples without lengthy and expensive extraction steps. Molecularly imprinted polymeric beads were used to immobilize carbaryl from biological samples. pH variation permitted the elution of carbaryl from the binding cavity to the flow cell. A pH electrode was used to detect changes in the charge of carbaryl in the sample solution resulting from the protonation and deprotonation of the molecule over different pH ranges. At pH 2.0, the secondary amine group is protonated, giving a (+1) charge to the carbaryl molecule. At pH 8.0, the ionized carbaryl loses a proton to become neutral, changing the local pH of the flow cell. The pH change at the flow cell generated by the deprotonation of carbaryl ion in alkaline medium was used to determine the carbaryl concentration. Parameters influencing the performance of the system were optimized for use in the detection procedure. The validated biosensor-like system had a carbaryl detection limit of 10.0 microg/mL and a response that was linear (r2>0.98) over the concentration range of 10.0-00 microg/mL.

Structural Investigation of Pd(II) in Concentrated Nitric and Perchloric Acid Solutions by XAFS

XAFS spectra of palladium(II) in concentrated HNO3/HClO4 acid mixtures have been recorded and analyzed. Structural parameters of the Pd(H2O)4(2+) complex and the mixed nitric Pd(NO3)2(H2O)2 complex, for the first time, were determined by the XAFS method. For pure 5 M HClO4 and for mixtures (0-0.3 M HNO3), the XAFS spectra of the 0.02 M Pd solutions are indeed very similar and originated from four Pd-O(w) equivalent distances. For the Pd(H2O)4(2+) square-planar aqua ion in strong perchloric acid, the use of an FEFF6 theoretical approach led to a first-shell Pd-O(w) distance of 2.00 (1) A and a Debye-Waller (DW) factor of sigma2 = 0.0030 (3) A2. Four water molecules are tightly bound to the Pd2+ ion in the equatorial plane, while two (or one) axial water molecules are weakly bound to the metal ion at 2.5 A with a DW factor of 0.015 (5) A2. For highly concentrated mixtures (4-6 M HNO3) and for pure concentrated (4-6 M) nitric acid as well as for crystalline powder Pd(NO3)2(H2O)2, the XAFS spectra are very similar and are determined by the mixed nitric complex Pd(NO3)2(H2O)2: four Pd-O near-equivalent distances of 2.01 (1) A from two H2O and two NO3 molecules with a total DW factor of sigma2 = 0.0037 (3) A2. Moreover, two Pd---N distances of 2.8-2.9 A were determined in the second coordination shell. Finally, for intermediate mixtures (1-3 M HNO3 in 5 M HClO4), the XAFS spectra are a superposition of the XAFS of Pd(H2O)4(2+) and Pd(NO3)2(H2O)2 complexes. The mean ligand number NO3(-) around Pd2+ has been calculated, and the XAFS results at pH close to zero confirm the spectrophotometric results previously published.

Factors associated with virological response in HIV-infected patients failing antiretroviral therapy: a prospective cohort study

OBJECTIVES

To assess the antiviral response to optimized therapy following genotypic resistance testing and to identify factors associated with virological response in HIV-1-infected patients failing antiretroviral therapy.

METHODS

A prospective cohort study was conducted in 344 HIV-1-infected patients who underwent genotypic resistance testing because of virological failure. Virological response was defined as a plasma HIV RNA level below 200 HIV-1 RNA copies/mL or a drop of plasma viral load from baseline of more than 1 log10. A multivariate logistic regression analysis was performed to identify factors associated with virological response.

RESULTS

The median age of the patients was 40 years, with a male to female ratio of 4:1. Fifty-one per cent of patients had received the three major classes of antiretrovirals and the median duration of previous antiretroviral therapy was 4.6 years. At baseline, the median plasma HIV RNA level was 4.4 log10 copies/mL and the median CD4 cell count was 274 cells/microL. At 3 months, 55% of patients (188 of 344) had a virological response, which was sustained at 6 months (53%). Predictors of virological response were exposure to two or fewer protease inhibitors [odds ratio (OR) 1.8; P=0.046], and use in optimized therapy of a new class of antiretrovirals (OR 2.9; P=0.006), of more than two new drugs (OR 3.0; P<0.0001), of abacavir (OR 1.9; P=0.03), or of lopinavir/ritonavir (OR 3.7; P=0.0002).

CONCLUSIONS

A high proportion of patients achieved a short-term virological response in this cohort study. Patients with the least experience of protease inhibitor treatment and in whom a new class of antiretroviral, more than two new drugs, abacavir or lopinavir/ritonavir was used in optimized therapy had the best virological outcome.

Troubles neuropsychiatriques chez les patients infectés par le VIH et rôle de l'efavirenz

Efavirenz has now become commonly used to treat HIV infection. Neuropsychiatric disorders have been reported in patients treated with efavirenz. Several factors often make it hard to determine the cause of these disorders: HIV infected patients take many different drugs, they may suffer from various organ diseases, and may also be heavily affected by problems in their everyday life. The French experts group working on neuropsychiatric side effects of efavirenz has undertaken a review of these disorders with the aim to identify: (1) semiology, (2) epidemiology in the global population, in HIV infected patients, and in patients treated with efavirenz. The expert group suggests recommendations to manage these disorders.

Assessment of cetirizine, an antihistamine, to prevent cutaneous reactions to nevirapine therapy: results of the viramune-zyrtec double-blind, placebo-controlled trial

We conducted a 12-week, multicenter, randomized, double-blind, placebo-controlled trial of cetirizine to assess the ability of antihistamines to prevent nevirapine-associated rash in patients infected with human immunodeficiency virus type 1. Patients initiating treatment with nevirapine were randomized to receive either cetirizine, 10 mg q.d. (104 patients), or placebo (96 patients) during the first 6 weeks of therapy. Rash occurred in 22 (11%) of 200 patients; 10 (9.6%) were in the cetirizine group and 12 (12.5%) were in the placebo group (odds ratio [OR], 0.75; 95% confidence interval [CI], 0.31-1.81; P=.5). Five of 22 rashes were cases of hypersensitivity syndrome. The rate of nevirapine discontinuation due to rash was similar in the 2 groups (7.7% and 6.25% in the cetirizine and placebo groups, respectively; P=.4). Multivariate analysis showed no treatment-group effect but indicated that age >40 years (OR, 3.83; 95% CI, 1.4-10.46; P=.008) was associated with an increased risk of rash. Cetirizine has no preventive effect on nevirapine-associated rash.

Chronic effects of vapour phase di-n-butyl phthalate (DBP) on six plant species

A fumigation experiment was performed in which six plant species representing the European flora were exposed to a range of DBP concentrations. Controlled amounts of DBP-saturated air were injected into the ingoing air-streams of plant fumigation chambers, maintaining constant concentrations there for a period of up to 76 days. The target concentrations were a control, 0.8, 1.5, 3.5, and 10.0 microg m(-3). The variation in sensitivity between plant species to atmospheric DBP was quantified on the basis of whole plant biomass in order to derive no-observed-effect-concentrations (NOECs). Significant dose-response relationships, based on realised concentrations, were thus derived using non-linear regression, resulting in NOECs of 0.51 microg m(-3) for Trifolium repens, 0.96 microg m(-3) for Brassica campestris, 1.87 microg m(-3) for Phaseolus vulgaris and 2.21 microg m(-3) for Plantago major. A significant effect was also observed for Holcus lanatus at 12.4 microg m(-3) DBP, but due to the variation at lower levels of DBP exposure, no dose-response relationship could be derived. No significant effect on growth of current year needles in Picea abies was observed, even at the highest level of DBP, 13.7 microg m(-3). Based on statistical extrapolation according to Aldenberg and Slob [Ecotox. Environ. Safety, 25 (1993) 48], an overall predicted no-effect concentration (PNEC) for the plant-atmosphere compartment of 0.33 microg m(-3) DBP was calculated. The PNEC was calculated using the mean and standard deviation of the NOEC for four of the tested species and an extrapolation factor. In addition to changes in leaf colour, leaf crinkling and growth reduction, a number of not quantified observations are described, indicating that DBP affects the physiology as well as the morphology of these species.