Observations and Projections of Heat Waves in South America.

Although Heat Waves (HWs) are expected to increase due to global warming, they are a regional phenomenon that demands for local analyses. In this paper, we assess four HW metrics (HW duration, HW frequency, HW amplitude, and number of HWs per season) as well as the share of extremely warm days (TX95, according to the 95th percentile) in South America (SA). Our analysis included observations as well as simulations from global and regional models. In particular, Regional Climate Models (RCMs) from the Coordinated Regional Climate Downscaling Experiment (CORDEX), and Global Climate Models (GCMs) from the Coupled Model Intercomparison Project Phase 5 (CMIP5) were used to project both TX95 estimates and HW metrics according to two representative concentration pathways (RCP4.5 and RCP8.5). We found that in recent decades the share of extremely warm days has at least doubled over the period December-January-February (DJF) in northern SA; less significant increases have been observed in southern SA. We also found that by midcentury, under the RCP4.5 scenario, extremely warm DJF days (as well as the number of HWs per season) are expected to increase by 5-10 times at locations close to the Equator and in the Atacama Desert. Increases are expected to be less pronounced in southern SA. Projections under the RCP8.5 scenario are more striking, particularly in tropical areas where half or more of the days could be extremely warm by midcentury.

Effects of soiling on photovoltaic (PV) modules in the Atacama Desert.

Soiling by dry deposition affects the power output of photovoltaic (PV) modules, especially under dry and arid conditions that favor natural atmospheric aerosols (wind-blown dust). In this paper, we report on measurements of the soiling effect on the energy yield of grid-connected crystalline silicon PV modules deployed in five cities across a north-south transect of approximately 1300 km in the Atacama Desert ranging from latitude 18°S to latitude 30°S. Energy losses were assessed by comparing side-by-side outputs of four co-planar PV modules. Two of the PV modules of the array were kept clean as a control, while we allowed the other two to naturally accumulate soiling for 12 months (from January 2017 to January 2018). We found that the combination of high deposition rates and infrequent rainfalls led to annual energy losses that peaked at 39% in the northern coastal part of the desert. In contrast, annual energy losses of 3% or less were measured at relatively high-altitude sites and also at locations in the southern part of the desert. For comparison, soiling-induced annual energy losses of about 7% were measured in Santiago, Chile (33°S), a major city with higher rainfall frequency but where urban pollution plays a significant role.

Ultraviolet radiation in the Atacama Desert.

The world's highest levels of surface ultraviolet (UV) irradiance have been measured in the Atacama Desert. This area is characterized by its high altitude, prevalent cloudless conditions, and a relatively low total ozone column. In this paper, we provide estimates of the surface UV (monthly UV index at noon and annual doses of UV-B and UV-A) for all sky conditions in the Atacama Desert. We found that the UV index at noon during the austral summer is expected to be greater than 11 in the whole desert. The annual UV-B (UV-A) doses were found to range from about 3.5 kWh/m2 (130 kWh/m2) in coastal areas to 5 kWh/m2 (160 kWh/m2) on the Andean plateau. Our results confirm significant interhemispherical differences. Typical annual UV-B doses in the Atacama Desert are about 40% greater than typical annual UV-B doses in northern Africa. Mostly due to seasonal changes in the ozone, the differences between the Atacama Desert and northern Africa are expected to be about 60% in the case of peak UV-B levels (i.e. the UV-B irradiances at noon close to the summer solstice in each hemisphere). Interhemispherical differences in the UV-A are significantly lower since the effect of the ozone in this part of the spectrum is minor.

[Approach of the unilateral cleft lip with Meara's cheiloplasty technique]. / Abordaje de la fisura labial unilateral mediante la queiloplastia de Meara.

INTRODUCTION: Isolated cleft lip is the mildest form of the cleft lip and palate spectrum; however those patients are often treated with the same surgical techniques that are used for the more severe cases (advancement-rotation flaps, quadrangular flaps). Meara's cheiloplasty technique may be a less aggressive option for lip repair in isolated cleft lip or whenever the gap between labial segments is not wide. MATERIAL AND METHODS: All children that had their cleft lip repaired following Meara's cheiloplasty between May 2014 and December 2015 were retrospectively reviewed. Duration of the surgical procedure, time to hospital discharge and complications were noted. Aesthetic results were evaluated in terms of lip height and symmetry, nose shape and symmetry, and scar appearance. RESULTS: Thirteen patients underwent Meara's cheiloplasty during this period. The average age was 6.11 months (5 to 12 months). A primary rhinoplasty was done at the same time in case of nasal asymmetry. Duration of the lip repair averaged 85 minutes. Oral feeding was started 4 hours after the procedure; bottle-feeding was withheld for 2 weeks postoperatively, as our protocol recommends after other lip repair techniques. In all 13 cases the result was a symmetrical, adequately high upper lip and a well-balanced nose, except for one case of lip scar retraction that was solved with triamcinolone infiltration. There were no other intra or postoperative complications. CONCLUSIONS: Meara's cheiloplasty corrects small or moderate gap cleft lip (usually cleft lip without cleft alveolus). Benefits over other teccniques are a shorter procedure and less geometric, undulate flaps that produce a harmonic lip.

INTRODUCCION: La fisura labial aislada es la forma menos grave de presentación del espectro de las fisuras labiopalatinas; sin embargo, para tratarla, usamos las mismas técnicas quirúrgicas que para las formas más graves (colgajos de avance-rotación, cuadrangulares). Presentamos la técnica de queiloplastia publicada por Meara, como alternativa menos agresiva para la reconstrucción del labio, en la fisura labial aislada o cuando los segmentos labiales están próximos entre sí. MATERIAL Y METODOS: Se realizó una revisión retrospectiva de las queiloplastias con técnica de Meara de mayo 2014 a diciembre 2015. Se revisó el tiempo quirúrgico, tiempo medio de ingreso, complicaciones y resultados estéticos, evaluando la altura y simetría del labio superior, la forma y simetría nasal y el aspecto de la cicatriz. RESULTADOS: Trece pacientes han sido intervenidos. La edad media al momento de la intervención fue de 6,11 meses (rango 5-12 meses). Se asoció una rinoplastia en casos con asimetría nasal. El tiempo quirúrgico medio de la queiloplastia aislada fue de 85 minutos. Se reinició alimentación oral a las 4 horas de la intervención, reanudando la alimentación mediante biberón a las 2 semanas, siguiendo el mismo protocolo que con las otras técnicas. En los 13 casos se consiguió un labio superior simétrico con altura adecuada y nariz armónica (excepto 1 que presentó retracción, tratada con infiltración de triamcinolona). No hubo otras complicaciones intra/postoperatorias. CONCLUSIONES: La queiloplastia de Meara corrige de forma muy armónica la fisura labial con poca o moderada separación de los segmentos labiales (habitualmente la fisura labial sin fisura alveolar). Como ventajas frente a otras técnicas permite, en una intervención más corta, la queiloplastia utilizando colgajos ondulados, que son menos geométricos y aportan armonía al resultado.

Abordaje de la fisura labial unilateral mediante la queiloplastia de Meara / Approach of the unilateral cleft lip with Meara’s cheiloplasty technique

Introducción. La fisura labial aislada es la forma menos grave de presentación del espectro de las fisuras labiopalatinas; sin embargo, para tratarla, usamos las mismas técnicas quirúrgicas que para las formas más graves (colgajos de avance-rotación, cuadrangulares). Presentamos la técnica de queiloplastia publicada por Meara, como alternativa menos agresiva para la reconstrucción del labio, en la fisura labial aislada o cuando los segmentos labiales están próximos entre sí. Material y métodos. Se realizó una revisión retrospectiva de las queiloplastias con técnica de Meara de mayo 2014 a diciembre 2015. Se revisó el tiempo quirúrgico, tiempo medio de ingreso, complicaciones y resultados estéticos, evaluando la altura y simetría del labio superior, la forma y simetría nasal y el aspecto de la cicatriz. Resultados. Trece pacientes han sido intervenidos. La edad media al momento de la intervención fue de 6,11 meses (rango 5-12 meses). Se asoció una rinoplastia en casos con asimetría nasal. El tiempo quirúrgico medio de la queiloplastia aislada fue de 85 minutos. Se reinició alimentación oral a las 4 horas de la intervención, reanudando la alimentación mediante biberón a las 2 semanas, siguiendo el mismo protocolo que con las otras técnicas. En los 13 casos se consiguió un labio superior simétrico con altura adecuada y nariz armónica (excepto 1 que presentó retracción, tratada con infiltración de triamcinolona). No hubo otras complicaciones intra/ postoperatorias. Conclusiones. La queiloplastia de Meara corrige de forma muy armónica la fisura labial con poca o moderada separación de los segmentos labiales (habitualmente la fisura labial sin fisura alveolar). Como ventajas frente a otras técnicas permite, en una intervención más corta, la queiloplastia utilizando colgajos ondulados, que son menos geométricos y aportan armonía al resultado (AU)

Introduction. Isolated cleft lip is the mildest form of the cleft lip & palate spectrum; however those patients are often treated with the same surgical techniques that are used for the more severe cases (advancement-rotation flaps, quadrangular flaps). Meara’s cheiloplasty technique may be a less aggressive option for lip repair in isolated cleft lip or whenever the gap between labial segments is not wide. Materials and methods. All children that had their cleft lip repaired following Meara’s cheiloplasty between May 2014 and December 2015 were retrospectively reviewed. Duration of the surgical procedure, time to hospital discharge and complications were noted. Aesthetic results were evaluated in terms of lip height and symmetry, nose shape and symmetry, and scar appearance. Results. Thirteen patients underwent Meara’s cheiloplasty during this period. The average age was 6.11 months (5 to 12 months). A primary rhinoplasty was done at the same time in case of nasal asymmetry. Duration of the lip repair averaged 85 minutes. Oral feeding was started 4 hours after the procedure; bottle-feeding was withheld for 2 weeks postoperatively, as our protocol recommends after other lip repair techniques. In all 13 cases the result was a symmetrical, adequately high upper lip and a well-balanced nose, except for one case of lip scar retraction that was solved with triamcinolone infiltration. There were no other intra or postoperative complications. Conclusions. Meara’s cheiloplasty corrects small or moderate gap cleft lip (usually cleft lip without cleft alveolus). Benefits over other teccniques are a shorter procedure and less geometric, undulate flaps that produce a harmonic lip (AU)

The Solar Spectrum in the Atacama Desert.

The Atacama Desert has been pointed out as one of the places on earth where the highest surface irradiance may occur. This area is characterized by its high altitude, prevalent cloudless conditions and relatively low columns of ozone and water vapor. Aimed at the characterization of the solar spectrum in the Atacama Desert, we carried out in February-March 2015 ground-based measurements of the spectral irradiance (from the ultraviolet to the near infrared) at seven locations that ranged from the city of Antofagasta (on the southern pacific coastline) to the Chajnantor Plateau (5,100 m altitude). Our spectral measurements allowed us to retrieve the total ozone column, the precipitable water, and the aerosol properties at each location. We found that changes in these parameters, as well as the shorter optical path length at high-altitude locations, lead to significant increases in the surface irradiance with the altitude. Our measurements show that, in the range 0-5100 m altitude, surface irradiance increases with the altitude by about 27% in the infrared range, 6% in the visible range, and 20% in the ultraviolet range. Spectral measurements carried out at the Izaña Observatory (Tenerife, Spain), in Hannover (Germany) and in Santiago (Chile), were used for further comparisons.

Treatment of Alzheimer disease using combination therapy with plasma exchange and haemapheresis with albumin and intravenous immunoglobulin: Rationale and treatment approach of the AMBAR (Alzheimer Management By Albumin Replacement) study. / Tratamiento de la enfermedad de Alzheimer mediante terapia combinada de aféresis terapéutica y hemoféresis con albúmina e inmunoglobulina intravenosa: fundamentos y aproximación terapéutica al estudio AMBAR (Alzheimer Management By Albumin Replacement).

INTRODUCTION: There is a growing interest in new therapeutic strategies for the treatment of Alzheimer disease (AD) which focus on reducing the beta-amyloid peptide (Aß) burden in the brain by sequestering plasma Aß, a large proportion of which is bound to albumin and other proteins. This review discusses the concepts of interaction between Aß and albumin that have given rise to AMBAR (Alzheimer's Disease Management by Albumin Replacement) project, a new multicentre, randomised, controlled clinical trial for the treatment of AD. DEVELOPMENT: Results from preliminary research suggest that Albutein(®) (therapeutic albumin, Grifols) contains no quantifiable levels of Aß. Studies also show that Albutein(®) has Aß binding capacity. On the other hand, AD entails a high level of nitro-oxidative stress associated with fibrillar aggregates of Aß that can induce albumin modification, thus affecting its biological functions. Results from the phase ii study confirm that using therapeutic apheresis to replace endogenous albumin with Albutein(®) 5% is feasible and safe in patients with AD. This process resulted in mobilisation of Aß and cognitive improvement in treated patients. The AMBAR study will test combination therapy with therapeutic apheresis and haemopheresis with the possible leverage effect of Albutein(®) with intravenous immunoglobulin replacement (Flebogamma(®) DIF). Cognitive, functional, and behavioural changes in patients with mild to moderate AD will be assessed. CONCLUSIONS: the AMBAR study represents a new therapeutic perspective for AD.

Native plasma-derived FVIII/VWF complex has lower sensitivity to FVIII inhibitors than the combination of isolated FVIII and VWF proteins. Impact on Bethesda assay titration of FVIII inhibitors.

Sensitivity to FVIII inhibitors of the native plasma-derived (pd) FVIII/VWF complex vs. the complexes formed after exogenous FVIII infusion in the haemophilic patient has not been thoroughly studied. The role of VWF in the interaction of FVIII with inhibitors was studied in vitro using different combinations of VWF and FVIII concentrates. Normal plasma, pdFVIII/VWF and isolated FVIII (recombinant FVIII, B-domain deleted and pdFVIII) were used. Titre (BU) was kinetically determined (up to 2 h) in serial dilutions of inhibitor IgG (purified from a pool of plasmas with inhibitors) mixed with VWF and then incubated with the different FVIII. Inhibitor was also added to previously mixed VWF+FVIII. Residual FVIII:C was determined. TGA assays were performed with FVIII-deficient plasma spiked with the FVIII-VWF mixtures with/without an ESH-8 antibody. Inhibitor titres for plasma and pdFVIII/VWF were comparable at all time points. Titres for all concentrates of isolated FVIII were significantly higher than those for plasma or pdFVIII/VWF (1.4-1.9 fold) even after preincubation with VWF. At t = 0 h, titres for plasma or pdFVIII/VWF were unquantifiable, but were detectable for isolated FVIII (0.6-1.6 BU). In contrast to pdFVIII/VWF, the decrease in thrombin generation parameters by isolated FVIII in the presence of ESH-8 was significant (P < 0.01) even when previously combined with VWF. In conclusion, VWF protection against FVIII inhibitor activity might be higher with native pdFVIII/VWF complex than with the corresponding compound formed from the isolated proteins. Bethesda assay titration using different FVIII concentrates would be advisable to guide the treatment of inhibitor patients.

Kinetics of the interaction between anti-FVIII antibodies and FVIII from therapeutic concentrates, with and without von Willebrand factor, assessed by surface plasmon resonance.

The presence of VWF in plasma-derived FVIII (pdFVIII/VWF) products has been pointed out as a key difference with recombinant FVIII (rFVIII) products with regard to immunogenicity. A Surface Plasmon Resonance (SPR) study was designed to characterize in detail the interaction between anti-FVIII (IgGs) from a severe haemophilia A patient, and FVIII from concentrates of different sources. Full-length rFVIII (preincubated or not with purified VWF), B domain-deleted (BDD)-rFVIII and pdFVIII/VWF were analysed. To ensure reproducible conditions for accurate determination of kinetic constants, a capture-based assay format was developed using protein G surfaces for specific and reversible coupling of endogenous anti-FVIII antibodies. Concentration ranges (nm) of FVIII products tested were 9-0.03 (rFVIII) and 6-0.024 (pdFVIII/VWF). The association with antibodies was monitored for 3-5 min, whereas dissociation of the complex was followed for 5-20-240 min. A strong interaction of rFVIII and BDD-rFVIII with patient's IgG was detected with the K (D) values in the low picomolar range (5.9 ± 3.0 and 12.7 ± 6.9 pm, respectively) and very slow dissociation rates, while pdFVIII/VWF showed only marginal binding signals. The VWF complexed rFVIII displayed reduced binding signals compared with uncomplexed rFVIII, but the K (D) was still in the picomolar range (4.1 ± 1.9 pm) indicating insufficient complex formation. rFVIII, alone or bound to exogenously added VWF, showed high affinity for anti-FVIII IgGs from a severe haemophilia A patient whereas pdFVIII/VWF did not. These results are in agreement with those studies that point towards rFVIII concentrates to be more immunogenic than pdFVIII concentrates.

Elimination capacity of a TSE-model agent in the manufacturing process of Alphanate/Fanhdi, a human factor VIII/VWF complex concentrate.

The variant Creutzfeldt-Jakob disease (vCJD) is a transmissible spongiform encephalopathy (TSE), mainly present in the UK and is associated with the ingestion of bovine products affected with bovine spongiform encephalopathy. Manufacturers of biological products must investigate the ability of their production processes to remove TSE agents. We studied the purification steps in the manufacturing process of two FVIII/VWF concentrates (Alphanate) and Fanhdi in their ability to eliminate an experimental TSE-model agent. Hamster scrapie strain 263K brain-derived materials were spiked into samples of the solutions taken before various stages during its production: 3.5% polyethylene glycol (PEG) precipitation, heparin affinity chromatography and saline precipitation/final filtrations. PEG precipitation and affinity chromatography were studied both as isolated and combined steps. TSE agent removal was determined using a laboratory scale model representative of the industrial manufacturing process. The prion protein (PrP(Sc)) was measured with Western blot and TSE infectivity was measured with bioassay. Western blot results were in agreement with those obtained by bioassay, showing a significant removal capacity in the production process: 3.21-3.43 log(10) for the PEG precipitation; about 3.45 log(10) for the affinity chromatography; and around 2.0 log(10) for the saline precipitation plus final filtrations. PEG precipitation and heparin affinity chromatography were demonstrated to be two complementary TSE-model agent removal mechanisms with total removal being the sum of the two. An overall reduction factor of around 8 log(10) can be deduced. The tests from the production process of FVIII/VWF complex concentrates have demonstrated their potential for eliminating TSE agents.

Flebogamma 5% DIF development: rationale for a new option in intravenous immunoglobulin therapy.

Flebogamma 5% dual inactivation and filtration (DIF), a new 5% liquid intravenous immunoglobulin with a stability of 2 years when stored at temperatures between 2 and 30 degrees C, has been developed. This new product is the result of the accumulated experience provided by Flebogamma, with more than 30 million grams administered since 1992 in Europe and the United States, and the implementation of the latest technology to improve Flebogamma even more by increasing its viral safety margin further. In addition to the specific inactivation stage for Flebogamma 5% (pasteurization), the new process includes a solvent-detergent treatment and nanofiltration through a Planova filter down to 20 nm. The preparation presents a mean purity of 99.6 +/- 0.2% with a correct chromatographic profile. Percentage values of immunoglobulin (Ig)G subclasses are equivalent to the physiological values of normal serum. The content in IgA as well as other possible impurities is very low, and the product presents a mean result of 109 +/- 5% in the Fc fragment functionality assay, demonstrating the integrity of the IgG molecule. The functionality is also reflected in neutralization tests carried out against poliomyelitis, diphtheria, measles and vaccinia which, apart from the antibody titres determined by enzyme-linked immunosorbent assay, guarantees that antibodies are capable of reacting against these pathogens. Regarding safety, the combination of multiple methods with capacity to inactivate or remove biological agents which include chemical inactivation, heat inactivation, nanofiltration and precipitations, with very different mechanisms of action, provides Flebogamma 5% DIF very wide margins of safety regarding to potential pathogens.

Safety procedures of coagulation factors.

Two main types of safety procedures must be applied to biological products, including plasma derivatives: (i) preventive procedures and (ii) elimination procedures. Prevention includes epidemiological control of donor populations; checks on each donor's health condition; analysis of each donation for the main pathogens using serological methods; additional analysis of all plasma for human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis A virus (HAV) and the B19 virus, using nucleic acid amplification techniques (NAT). A 60 days or longer inventory hold of all plasma donations is applied, to allow additional time to discard previous donations from potential seroconverting or otherwise rejectable donors. Elimination procedures minimize the low residual risk of transmitting pathogens, including unknown or previously undetected ones. Since the introduction 20 years ago of solvent-detergent treatment, very effective against enveloped viruses (HIV, HBV, HCV, West Nile virus, SARS, avian influenza virus etc), there have been no known cases of transmission of this type of pathogens by products manufactured according to this procedure. Other inactivation procedures such as pasteurization, dry-heat or nanofiltration may prove equally effective. In addition, dry-heat treatment and nanofiltration are capable of effectively eliminating non-enveloped viruses (HAV, B19 virus). Recent studies show that the B19 virus is much more sensitive to heat (in lyophilized state or by pasteurization) and acid pH than previously thought. Although there is no evidence for the transmission of classic transmissible spongiform encephalopathies (TSEs) through blood or blood-products transfusion, four possible cases have been reported in the United Kingdom involving transmission by non-leukoreduced blood components of the agent that causes variant Creutzfeldt-Jakob Disease (vCJD), a disease linked to the outbreak of bovine spongiform encephalopathy (BSE) which took place in that country. However, there are no cases of human TSE (classic or variant) transmission by plasma-derived products. Analytical methods capable of detecting the vCJD agent in patients' brains (where high titres are found) and other tissues (such as the spleen, appendix and lymph nodes, where much lower concentrations are found) are unable to detect the agent in blood or plasma from patients with vCJD, even in the clinical phase of the disease. Experiments by Grifols and other groups show that the capacity of the production processes to eliminate vCJD agent models is many orders of magnitude greater than the maximum expected load of the agent. In this regard, the efficacy of precipitation, affinity chromatography, depth filtration and nanofiltration are particularly notable.

Critical factors influencing prion inactivation by sodium hydroxide.

BACKGROUND AND OBJECTIVES: Transmissible spongiform encephalopathies (TSEs) are fatal neurodegenerative diseases caused by aberrantly folded cellular proteins (PrP(Sc); prions) that are generally resistant to conventional pathogen-inactivation techniques. To ensure effective decontamination and inactivation of prions that could be present in source material, we investigated critical factors that influence prion inactivation by NaOH. MATERIALS AND METHODS: A decrease in prion infectivity correlates with the disappearance of the protease-resistant core of PrPSc (PrPRES) observed in biochemical assays. To model prion inactivation, hamster scrapie (strain 263K) brain homogenate (SBH) was incubated for specific periods of time in 0.1 m NaOH at 4 or 18 degrees C, with or without detergent. Neutralized samples were subjected to limited digestion with proteinase K (PK) and then analysed using an endpoint dilution western blot assay and antibody 3F4. Structural changes in prions exposed to NaOH were examined using differential immunoprecipitation. RESULTS: Treatment of SBH with 0.1 m NaOH for 15 min, in the absence of detergent, at 4 and 18 degrees C caused a reduction in the PrP(RES) signal of 3.5 and 4.0 log10 units, respectively, with some residual signal remaining. The presence of the detergent sarkosyl during a 60-min incubation in NaOH further enhanced PrPRES reduction to > or = 4.5 log10 units (i.e. below the limit of detection). NaOH treatment induced conformational changes in PrP that resulted in the exposure of a hidden epitope and enabled prion immunoprecipitation by antibody 3F4. CONCLUSIONS: The use of NaOH can effectively reduce prion levels in an in vitro inactivation assay. After pretreatment of SBH with detergent, NaOH completely eliminates the PrPRES signal. Detergent may liberate lipid membrane-protected PrPSc to improve access to NaOH, which can then inactivate PrPSc by altering its structure. In cases of unidentified exposure to PrPSc during manufacturing, sanitizing procedures combining the use of detergent and NaOH may help to ensure minimal levels of contamination carryover in products.

Possible alternative to European Pharmacopoeia's method of analysis Test for Fc Function of Immunoglobulin (2.7.9) by using tetanus toxoid as antigen.

Preparations of intravenous immunoglobulins must keep functional integrity throughout the purification process. In order to assess Fc fragment functionality, the European Pharmacopoeia proposes the Test for Fc function of immunoglobulin (2.7.9), which is based on a rubella antigen of high titre. Sometimes, such antigen is difficult to obtain. In the present study, we develop the same assay using tetanus toxoid instead of rubella antigen, adapting the procedure for the use of tetanus toxoid. The comparison between rubella-based and tetanus-based assays showed that the slopes of the haemolysis curves were higher if red blood cells had been sensitised with the rubella antigen than with tetanus toxoid. Nonetheless, the tetanus-based assay gave satisfactory results and it could be a good alternative antigen target.

Effect of temperature on plasma freezing under industrial conditions.

The European Pharmacopoeia monograph on Human plasma for fractionation does not define the freezing process time but does define the freezing temperature (- 30 degrees C or below). Initial freezing conditions are crucial for the quality of plasma. These conditions were intended to preserve labile proteins such as fVIIl, but they can also be considered favourable for the plasma quality in general. This study evaluates the way the industrial plasma freezing affects labile coagulation factors. We have studied the freezing of plasma in industrial-size chambers at temperatures close to - 30 degrees C, - 25 degrees C and - 20 degrees C, and the possible differences between performing the freezing process in a chamber or in a freezer, in order to elucidate whether or not these parameters affect the quality of plasma. For this study, plasma bottles were frozen in industrial chambers set at - 30 degrees C, - 25 degrees C and - 20 degrees C, and in a freezer set at - 20 degrees C. The freezing rates were followed by means of probes in plasma control bottles. From this plasma, coagulation factors (fVIII, fIX and fibrinogen) were analysed before and after freezing, and cryoprecipitate was obtained in some cases. Statistically significant differences exist in fVIII:C recovery in thawed plasma between freezing at - 30 degrees C and at - 20 degrees C (n = 11; 85.4 +/- 4.3 % versus 74.6 +/- 6.0 % (chamber) or 79.3 +/- 6.3 % (freezer)). There is no difference between - 30 degrees C and - 25 degrees C, or between freezing at - 20 degrees C in a chamber or in a freezer. No significant loss of activity in thawed plasma is observed for fIX and fibrinogen at - 25 degrees C or - 20 degrees C versus - 30 degrees C. The fVIII and vWF recovery in cryoprecipitates does not show differences (464.2 IU fVIII/ml at - 30 degrees C, 446.7 IU fVIII/ml at - 25 degrees C, and 475.8 IU fVIII/ml at - 20 degrees C). The results obtained from this study support that plasma might also be frozen at - 25 degrees C or below without any impact on its quality, and that sporadic and short term deviations, from - 30 degrees C or below up to - 25 degrees C, in the currently required freezing temperature, would not have an effect on the labile factors recovery.

Physiological and clinical effects of diurnal noninvasive ventilation in hypercapnic COPD.

To assess the clinical impact of noninvasive mechanical ventilation (NIMV) on stable hypercapnic chronic obstructive pulmonary disease, changes in exercise capacity, dyspnoea and simple physiological parameters were evaluated. The time course of these effects during treatment and recovery was also assessed. Patients were randomly allocated to NIMV (n=27) or sham-NIMV (n=15), applied 3 h.day-1, 5 days a week, for 3 weeks. A 6-min walking distance (6MWD), arterial blood gases, spirometry, pattern of breathing, mouth occlusion pressure (P0.1), and respiratory system impedance (P0.1/tidal volume (VT)/inspiratory time (tI)) were measured weekly during treatment and 2 weekly during follow-up. Transition dyspnoea index (TDI) was also measured. During NIMV, carbon dioxide arterial tension decreased progressively, concomitantly with a slow deep pattern of breathing, a proportional increase in the forced expiratory volume in one second (FEV1), the forced vital capacity and significant reductions of P0.1 and P0.1/VT/tI. The 6MWD improved by a mean of 76 m after NIMV, and by 73 m and 61 m 1 and 2 weeks, respectively, after treatment. Dyspnoea improved with a mean TDI of three points. Changes in 6MWD were highly related to TDI and to a lesser extent to changes in FEV1 (r=0.60). The current authors conclude that noninvasive mechanical ventilation has significant and sustained clinical impact in stable hypercapnic chronic obstructive pulmonary disease.

Efecto del bromuro de ipratropio sobre la hiperinflación pulmonar dinámica en pacientes con enfermedad pulmonar obstructiva crónica / Effect of ipratropium bromide on lung dynamic hyperinflation in patients with chronic obstructive lung disease

BACKGROUND: The six minute walk test (6 MW) elicits dynamic hyperinflation (DH) in severe COPD patients, which can be evaluated by reductions in inspiratory capacity (IC). Although IC is currently used to determine the effects of bronchodilators on DH during exercise tests on a cycle ergometer, its usefulness during a walking test has not been evaluated. AIM: To study the acute effects of ipratropium bromide (IB) on forced expiratory volume at l second (FEV1) and IC at rest and on DH during exercise assessed by the 6 MW. SUBJECTS AND METHODS: Fifteen stable COPD patients were randomly allocated in a double-blind, placebo-controlled, crossover fashion to 2 treatment periods using a single dose of nebulized IB 500 mg or placebo. Spirometry, including IC, and 6 MW were measured at baseline and after IB and placebo. IC was also measured 15 min after exercise. Dyspnea, oxygen saturation (SpO2) and heart rate were assessed at the end of exercise. RESULTS: After IB, 8/15 patients exhibited a clinically significant increase in IC (> or = 10 per cent predicted). A similar increase in FEV1 was observed in only one patient. No changes were observed with placebo. A significant increase in 6 MW from baseline (p = 0.007) was found after IB (45 +/- 14 m) compared to placebo (0.5 +/- 9 m), whereas dyspnea was significantly lower. Inspiratory capacity fell after 6 MW with both treatments, but it reached their baseline values at 15 min after exercise only with IB. CONCLUSIONS: Our results demonstrate that IC provides additional information to conventional spirometry on the acute effects of bronchodilators and confirm its value to assess DH during a walking test.

Influence of von Willebrand factor on the reactivity of human factor VIII inhibitors with factor VIII.

In order to determine the difference in reactivity of factor (F) VIII inhibitors against the FVIII/von Willebrand factor (vWF) complex and against vWF-deficient FVIII, we investigated a panel of 10 antibodies to FVIII from multitransfused individuals with severe haemophilia A and other pathologies. Immunoblotting of purified FVIII and purified thrombin-cleaved FVIII revealed that in all cases inhibitor epitopes could be localized in the heavy chain (A2 subunit) while in four cases they were also present in the light chain. One of the FVIII inhibitors remained unclassified. The effect on FVIII:C of purified IgG from inhibitor plasmas was tested against a high purity FVIII/vWF concentrate and a monoclonally purified FVIII concentrate with only trace contents of vWF, by two different functional assays. Our results suggest that for those inhibitors showing A2 plus light chain (LC) reactivity, the IgG concentration required to inhibit 50% of FVIII activity in vitro is higher for the FVIII/vWF complex than for the vWF-deficient FVIII. We conclude that there might be a protective role of vWF (at least in vitro) against FVIII inhibitors with A2 and LC subunit specificity.