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SummaryIn patients with common variable immune deficiencies, primary vaccination followed by two booster doses is recommended for protection against COVID-19. Seroconversion has been shown in 60% of patients. We have no information on whether serum antibodies reflect the generation of durable immune memory.In a longitudinal study on 47 common variable immune deficiencies patients who received the third and fourth vaccine dose, we show that the measurement of specific antibodies is not sufficient to predict the establishment of immune memory and the ability to respond to antigen re-exposure.Our results indicate that the combination of antibodies and memory B cells responses represents a more reliable read-out of vaccine immune efficacy in vulnerable patients.This analysis may not only identify individuals remaining unprotected after vaccination and unable to respond to additional booster doses, but also address the search for the underlying immune defect and suggest patient-tailored management strategies.

Digital ischemia due to arterial defects need urgent surgical management. The traditional treatment consists of vascular reconstruction using a reversed autologous venous graft as a bypass. Very few studies have described the use of arterial grafts for digital artery reconstruction. This cadaver study characterized the forearm perforator arteries to assess the potential feasibility of using them as donor grafts for digital artery reconstruction. Eleven forearms and twenty hands were dissected from freshly injected cadavers. All clinically significant perforators (>0.5 mm) derived from radial or ulnar arteries and digital arteries were evaluated. The digital palmar arteries were measured at three points: metacarpophalangeal (MCP) joint, proximal interphalangeal (PIP) joint, and distal interphalangeal (PIP) joint. In the 11 forearms analyzed, 5.5 ± 1.3 perforators from radial or ulnar arteries with a diameter of at least 0.5 mm were found per dissection. The mean diameters were 0.9 ± 0.18 mm proximally and 0.8 ± 0.15 mm distally; the mean length was 35.6 ± 11.35 mm. The mean diameters for the dominant and non-dominant arteries were 1.5 and 1.3 mm at the MCP, 1.3 and 1.0 mm at the PIP, 0.8 and 0.7 mm at the DIP, respectively. The forearms are good donor sites as they have large-diameter arteries of suitable length for arterial grafting. These new arterial grafts may be suitable for vascular reconstruction of digital arteries starting from the PIP joint.

Growing evidence report that non-genetic-driven events such as enhancer reprogramming promote neoplastic transformation and strongly contribute to the phenotypical heterogeneity of cancers as much as genetic variation. In this context, we investigated the role of enhancers in sustaining oncogenic transformation in B-Cell Acute Lymphoblastic leukemia in children (BCP-ALL), a type of cancer caused by the accumulation of lymphoid progenitor cells in the bone marrow and a leading cause of cancer-related mortality in children. Using next-generation sequencing (ATAC-seq), we built the most up-to-date map of chromatin accessibility in pediatric BCP-ALL. We observed that enhancer activity dynamically changes during cancer progression and represents principal phenomena underlying phenotypic–functional characteristics of BCP-ALL progression. BCP-ALL patients are dominated by a regulatory repertoire (N=∼11k) originally represented at diagnosis that shrinks under treatments and subsequently re-expands, driving the relapse. We then deployed a wide range of in-vivo, in-vitro assays, and in-silico analyses to demonstrate the impact of enhancer activity in determining the phenotypical complexity. CRISPR-Cas-9-mediated validation of selected productive enhancers demonstrated a high capability of these regions to control MYB and DCTD oncogenic activities. Taken together, these findings provide direct support to the notion that enhancer plasticity is a crucial determinant of the BCP-ALL phenotype.

Kidney international 102(1), 160-172 (2022). doi:10.1016/j.kint.2022.02.042, Published by Elsevier, New York, NY

Background: Genitourinary syndrome of menopause (GSM) is the new term for vulvovaginal atrophy (VVA). The condition is relevant in more than 50% of women, having an adverse impact on quality of life and sexual relationships. Objective: To assess the efficacy and safety of a new type of non-ablative laser, Solid State Vaginal Laser (SSVL), for vaginal tissue regeneration and rejuvenation. Method: Eighty participants with GSM symptoms were treated with a total of 4 treatments in about two months (every 15 - 20 days) of a non-ablative SSVL (LASEmaR 1500TM-EUFOTON). A cumulative intensity of GSM symptoms using a 10-cm VAS (dryness and/or burning and/or dyspareunia), the vaginal health index (VHI), the Female Sexual Function Index (FSFI) were evaluated. Urinary Incontinence Short Form (ICIQ-UI SF) and vaginal bioptic samples were also collected. Results: Improvement following the SSVL was observed on VHIS, VVA symptoms and sexual female function. This finding was also ratified by the improvement of vaginal histological features. After the SSVL treatment, almost all patients (91%) affected by urinary incontinence obtained the complete remission of symptoms. Conclusion: The objective evaluation of VHIS, FSFI and ICIQ-UI SF scores and the histological results indicates a real favorable effect of SSVL on GSM and on urinary incontinence.

Resume Introduction La mastocytose systemique est caracterisee par une proliferation anormale de mastocytes dans differents organes. Nous rapportons le cas original d’une mastocytose systemique revelee par un œdeme vulvaire. Observation Une femme de 24 ans consultait en dermatologie pour un œdeme vulvaire apparaissant au moment des rapports sexuels. Elle presentait des episodes vasomoteurs des membres inferieurs, une urticaire du tronc a l’effort, des diarrhees et des douleurs osseuses. Le bilan biologique montrait une tryptasemie a 29,7 μg/L et une histaminemie a deux fois la normale. Le myelogramme mettait en evidence une infiltration par des mastocytes dysmorphiques. La recherche de la mutation D816V du gene c-kit etait positive. Les biopsies duodenales revelaient des amas de mastocytes avec plus de 15 mastocytes agreges. L’immunomarquage CD2 etait non contributif et le CD25 non realise. Une osteopenie trabeculaire etait constatee. Nous avons pose le diagnostic de mastocytose systemique indolente (ISM variant Ia) d’apres les criteres OMS 2008. Un traitement symptomatique a ete instaure (anti-histaminiques anti-H1 et anti-H2, antileucotrienes), ainsi qu’un suivi clinicobiologique. Discussion Les symptomes qui ont conduit ici au diagnostic de mastocytose systemique avec atteinte de plusieurs organes etaient des signes cutanes qui pouvaient paraitre mineurs, lies a la degranulation mastocytaire. Il s’agit du troisieme cas decrit de mastocytose revelee par un œdeme vulvaire et du premier cas revelant une atteinte systemique. Les deux cas precedemment decrits avaient revele une mastocytose cutanee pure. La mastocytose, systemique ou cutanee, doit faire partie des diagnostics differentiels a evoquer devant un œdeme vulvaire.

Background The majority of the cases of bone marrow failure syndromes/aplastic anaemias (BMFS/AA) are non-hereditary and considered idiopathic (80–85%). The peripheral blood picture is variable, with anaemia, neutropenia and/or thrombocytopenia, and the patients with idiopathic BMFS/AA may have a risk of transformation into a myelodysplastic syndrome (MDS) and/or an acute myeloid leukaemia (AML), as ascertained for all inherited BMFS. We already reported four patients with different forms of BMFS/AA with chromosome anomalies as primary etiologic event: the chromosome changes exerted an effect on specific genes, namely RUNX1, MPL, and FLI1, leading to the disease. Results We report two further patients with non-hereditary BM failure, with diagnosis of severe aplastic anaemia and pancytopenia caused by two different constitutional structural anomalies involving chromosome 8, and possibly leading to the disorder due to effects on the RUNX1T1 gene, which was hypo-expressed and hyper-expressed, respectively, in the two patients. The chromosome change was unbalanced in one patient, and balanced in the other one. Conclusions We analyzed the sequence of events in the pathogenesis of the disease in the two patients, including a number of non-haematological signs present in the one with the unbalanced anomaly. We demonstrated that in these two patients the primary event causing BMFS/AA was the constitutional chromosome anomaly. If we take into account the cohort of 219 patients with a similar diagnosis in whom we made cytogenetic studies in the years 2003–2017, we conclude that cytogenetic investigations were instrumental to reach a diagnosis in 52 of them. We postulate that a chromosome change is the primary cause of BMFS/AA in a not negligible proportion of cases, as it was ascertained in 6 of these patients. Electronic supplementary material The online version of this article (10.1186/s13039-017-0352-2) contains supplementary material, which is available to authorized users.

Upon ageing, chronic exposure to ultraviolet radiations and pollution induces benign hyper-pigmented lesions, such as Solar Lentigo maculae (SL) 1. Well-defined histologically, SL is distinguishable from other hyper-pigmented diseases and can be classified relative to its evolution 2-4. Differential gene-profiling analyses comparing SL and normal skin biopsies revealed that SL tissues are mainly composed of epidermal activated melanocytes as well as hypo-proliferating and hypo-differentiated keratinocytes with a background of chronic inflammation. In absence of fibroblast markers, immuno-staining analyses for several growth factors and secreted proteins in the upper dermis of SL biopsies strongly suggest that dermal fibroblasts contribute functionally to dysregulation of epidermal cells 5. These observations are strengthened by recent studies using a pigmented reconstructed skin model that demonstrates the influence of dermal fibroblasts on skin pigmentation 6. However, data on the morphological and functional features of the SL primary fibroblasts that could explain their role in SL disease are not available. This article is protected by copyright. All rights reserved.

From 1991 until 2013, 304 patients with intracranial hematomas from aneurysmal rupture were managed surgically in our department, constituting 17 % of all patients with aneurysmal rupture. Of them, 242 patents presented with isolated intracerebral hematomas (in 69 cases associated with significant intraventricular hemorrhage), 50 patients presented with combined intracerebral and subdural hematomas (in 11 cases associated with significant intraventricular hemorrhage), and 12 presented with an isolated subdural hematoma. The surgical procedure consisted of simultaneous clipping of the aneurysm and evacuation of the hematoma in all cases. After surgery, 16 patients (5 %) submitted to an additional decompressive hemicraniectomy, and 66 patients (21 %) submitted to a ventriculo-peritoneal shunt. Clinical outcomes were assessed at discharge and at 6 months, using the modified Rankin Scale (mRS); a favorable outcome (mRS 0-2) was observed in 10 % of the cases at discharge, increasing to 31 % at 6 months; 6-month mortality was 40 %. Applying uni- and multivariate analysis, the following risk factors were associated with a significantly worse outcome: age60; preoperative Hunt-Hess grades IV-V; pupillary mydriasis (only on univariate); midline shift10 mm; hematoma volume30 cc; and the presence of hemocephalus (i.e., packed intraventricular hemorrhage). Based on these results, an aggressive surgical treatment should be adopted for most cases with aneurysmal hematomas, excluding patients with bilateral mydriasis persisting after rescue therapy.

This is the first report on the occurrence of cocaine (COC) and benzoylecgonine (BE) residues in six samples collected from different wastewater treatment plants (WTP) located in the Brazilian Federal District (FD). Concentrations of BE in the influent sewage were used to calculate cocaine consumption (kg year-1 per 1000 inhabitants) for each region attended by the WTP from two sampling campaigns (March and June, 2010). Among the WTP studied, samples from Samambaia showed higher concentrations (from 3866 to 2477 ng L-1 of BE and 805 to 579 ng L-1 of COC) and doses per inhabitants (more than 13 doses inhabitant-1 per year). The extrapolation to the whole FD population points out to an annual consumption reaching 1.0 ton of free base cocaine, or 1.1 tons of cocaine hydrochloride. The work also addresses the influence of the cocaine presentation form (free base or hydrochloride) and the integration with chemical profiling results in a more realistic estimate, mainly concerning the viewpoints of forensics and law enforcement. Este é o primeiro trabalho que relata a ocorrência de resíduos de cocaína (COC) e benzoilecgonina (BE) em amostras coletadas em seis estações de esgoto diferentes (ETE) instaladas no Distrito Federal (DF) do Brasil. As concentrações de BE nos afluentes de esgoto foram utilizadas para calcular o consumo de cocaína (kg ano-1 por 1000 habitantes) em cada uma das regiões atendidas pelas ETE, em duas campanhas de amostragem (março e junho de 2010). Dentre as ETE estudadas, amostras provenientes de Samambaia apresentaram as maiores concentrações (de 3866 a 2477 ng L-1 de BE e 805 a 579 ng L-1 de COC) e doses por habitante (mais de 13 doses habitante-1 por ano). A extrapolação para toda a população do DF indica um consumo anual alcançando 1,0 tonelada de cocaína base livre, ou 1,1 tonelada de cloridrato de cocaína. Este trabalho também aborda a influência da forma de apresentação da cocaína (base livre ou sal cloridrato) e a integração com resultados de perfil químico na busca de estimativas mais realistas, principalmente no que se refere aos pontos de vista da criminalística e da segurança pública.

A liquid chromatography-electrospray tandem mass spectrometry (LC-MS/MS) method for the determination of antibiotics in water was developed and applied to Brazilian surface waters. Amoxicillin, ampicillin, cefalexin (CEF), ciprofloxacin (CIP), norfloxacin (NOR), sulfamethoxazole, tetracycline (TET), and trimethoprim were selected as target compounds due to their high consumption pattern in Brazil. LC and MS conditions were optimized to produce the maximum analytic response for each compound. Anion exchange and polymeric solid-phase extraction cartridges, in series, were employed during the extraction procedures. Recovery, linear range, limit of detection (LOD), and limit of quantification were calculated. LOD varied from 0.13 ng L(-1) for CIP and NOR to 0.76 ng L(-1) for TET. Surface water samples from the Atibaia watershed (São Paulo State, Brazil) were analyzed. Results showed that seasonal and anthropogenic aspects dictated the levels of antibiotics in the samples. An overall frequency of detection of 55% was observed during the rainy period, whereas a higher percentage (88%) was noticed for samples collected during the dry season. In the Atibaia River, sample concentrations ranged from 29 ng L(-1) for CEF to 0.5 ng L(-1) for NOR. In a sewage-affected stream, however, concentrations up to 2422 ng L(-1) CEF were found.

The goal of this work was to investigate the occurrence of emerging contaminants in drinking water of the city of Campinas, Brazil. Tap water samples were analyzed using SPE-GC-MS for 11 contaminants of recent environmental concern. Six emerging contaminants (stigmasterol, cholesterol, bisphenol A, caffeine, estrone, and 17β-estradiol) were found in the samples. The latter two were detected only during the dry season, with concentrations below quantification limits. Stigmasterol showed the highest average concentration (0.34 ± 0.13 µg L−1), followed by cholesterol (0.27 ± 0.07 µg L−1), caffeine (0.22 ± 0.06 µg L−1), and bisphenol A (0.16 ± 0.03 µg L−1). In Campinas, where surface drinking water supplies receive large amounts of raw sewage inputs, the emerging contaminants levels in drinking waters were higher than median values compiled for drinking and finished water samples around the world.

Polycyclic aromatic hydrocarbon (PAH) components of diesel fuel are considered hazardous, due to their toxicity. We report the degradation of 16 PAHs using photo-Fenton and photo-Fenton-like processes in two different soil samples (S1 and S2) artificially contaminated with diesel oil. Experimental factorial designs were used to determine the most effective treatment conditions, with a view to achieving economical feasibility. For photo-Fenton reactions, the best degradation conditions resulted in an overall PAH concentration reduction of 94.6% and 95.6% for soils S1 and S2, respectively. The photo-Fenton-like processes also led to satisfactory degradation levels, obtained with only endogenous iron, low hydrogen peroxide concentration, short exposure time and no soil pH adjustment. These results demonstrate the viability of photo-Fenton-like processes to treat PAH contaminated areas. Hidrocarbonetos policíclicos aromáticos (HPA) estão presentes no óleo diesel, sendo considerados perigosos devido à sua toxicidade. Neste estudo relatamos a degradação de 16 HPA em dois solos diferentes (S1 e S2) contaminados artificialmente com óleo diesel, usando processos foto-Fenton e pseudo-foto-Fenton. Planejamentos fatoriais foram usados para obter condições de tratamento mais eficientes e econômicas. Para a reação foto-Fenton, as condições mais favoráveis resultaram 94,6% e 95,6% de degradação dos HPA para os solos S1 e S2, respectivamente. O processo pseudo-foto-Fenton também apresentou um nível satisfatório de degradação, obtido em condições econômicas, com ferro endógeno, baixa concentração de peróxido, curto tempo de exposição à radiação e sem ajuste do pH do solo. Os resultados demonstram a eficiência do processo pseudo-foto-Fenton para tratar áreas contaminadas por HPA.

Microalbuminuria independently predicts increased cardiovascular risk in hypertensive patients, especially in those with concomitant diabetes or established cardiovascular disease. Drugs that target the renin-angiotensin-aldosterone system reduce microalbuminuria regardless of diabetic status. The Irbesartan in the Management of PROteinuric patients at high risk for Vascular Events was a multicenter, randomized, double-blind, placebo-controlled paralleled group study in which hypertensive patients with microalbuminuria and increased cardiovascular risk were randomized to 20 weeks treatment with ramipril plus irbesartan or to ramipril plus placebo. Patients discontinued or tapered previous antihypertensive therapy during a 14-day placebo lead-in period. Change in albumin excretion rate from baseline to week 20 was the primary end point. Adjusted week 20 baseline geometric ratios for ramipril plus irbesartan and ramipril plus placebo were not significantly different. Although differences in blood pressure reductions were observed between the two treatments, these changes did not affect microalbuminuria. More patients on dual therapy achieved target blood pressure goals at week 20 than with monotherapy. The incidence of adverse effects and treatment-related adverse effects was similar in both groups. Our results suggest that patients with cardiovascular risk and relatively low albumin excretion rates in early-stage disease may only require monotherapy with renin-angiotensin-aldosterone blocking agents.

Occurrence of endocrine disrupting chemicals and pharmaceutical products in surface freshwaters from Campinas region (SP, Brazil) The aim of this work was to evaluate the occurrence of some emerging organic compounds in surface freshwaters samples collected in the Metropolitan Region of Campinas. Ten substances classified as endocrine disrupting chemicals as well as five pharmaceutical drugs were investigated in samples from six individual sampling points in the Atibaia River basin. Samples were submitted to solid phase extraction and the extracts were analyzed by high performance liquid chromatography. Exogenous organic compounds were detected in 83% of the samples. More than one compound, amongst the fifteen, was determined in 66% of the samples. 17β-estradiol, 17α-ethynylestradiol, paracetamol (acetaminophen), acetylsalicylic acid, di-n-butyl phthalate, bisphenol A, and caffeine were detected at least once. Higher levels of 17β-estradiol, 17α-ethynylestradiol, bisphenol A, and caffeine were detected in the sampling point located downstream the city of Campinas, evidencing the contamination in this water body. Finally, it was noticed that during the low precipitation period the concentration of the majority analyzed compounds increases.

Background Aedes aegypti is the primary vector of dengue fever, a viral disease which has an estimated incidence of 390 million infections annually. Conventional vector control methods have been unable to curb the transmission of the disease. We have previously reported a novel method of vector control using a tetracycline repressible self-limiting strain of Ae. aegypti OX513A which has achieved >90% suppression of wild populations. Methodology/Principal Findings We investigated the impact of tetracycline and its analogues on the phenotype of OX513A from the perspective of possible routes and levels of environmental exposure. We determined the minimum concentration of tetracycline and its analogues that will allow an increased survivorship and found these to be greater than the maximum concentration of tetracyclines found in known Ae. aegypti breeding sites and their surrounding areas. Furthermore, we determined that OX513A parents fed tetracycline are unable to pre-load their progeny with sufficient antidote to increase their survivorship. Finally, we studied the changes in concentration of tetracycline in the mass production rearing water of OX513A and the developing insect. Conclusion/Significance Together, these studies demonstrate that potential routes of exposure of OX513A individuals to tetracycline and its analogues in the environment are not expected to increase the survivorship of OX513A., Author Summary Dengue fever is spread by the mosquito Aedes aegypti and the most effective method to limit the spread of dengue is to reduce the mosquito population. We have previously reported a transgenic strain of Ae. aegypti which results in >90% population suppression: males, which do not transmit disease, are released into the field carrying a self-limiting gene to mate with wild females, passing on the self-limiting gene which causes >95% progeny to die before becoming vectors of disease. To be able to breed this mosquito in the laboratory an antidote, tetracycline, is used to suppress the effects of the transgene. Given that tetracyclines are commonly used in human and veterinary medicine, it is essential to consider whether sufficient tetracycline could be in the environment to prevent the effective use of this control method by allowing the female’s progeny (from a mating between a released OX513A male and a wild female) to survive. Here we have shown that the concentrations of tetracycline to which the mosquitoes will be exposed in the environment, both in breeding sites and in a blood-meal host are not high enough to influence the effectiveness of this control method.

Intravenous (IV) iron therapy is widely used in iron deficiency anaemias when oral iron is not tolerated or ineffective. Administration of IV‐iron is considered a safe procedure, but severe hypersensitivity reactions (HSRs) can occur at a very low frequency. Recently, new guidelines have been published by the European Medicines Agency with the intention of making IV‐iron therapy safer; however, the current protocols are still non‐specific, non‐evidence‐based empirical measures which neglect the fact that the majority of IV‐iron reactions are not IgE‐mediated anaphylactic reactions. The field would benefit from new specific and effective methods for the prevention and treatment of these HSRs, and the main goal of this review was to highlight a possible new approach based on the assumption that IV‐iron reactions represent complement activation‐related pseudo‐allergy (CARPA), at least in part. The review compares the features of IV‐iron reactions to those of immune and non‐immune HSRs caused by a variety of other infused drugs and thus make indirect inferences on IV‐iron reactions. The process of comparison highlights many unresolved issues in allergy research, such as the unsettled terminology, multiple redundant classifications and a lack of validated animal models and lege artis clinical studies. Facts and arguments are listed in support of the involvement of CARPA in IV‐iron reactions, and the review addresses the mechanism of low reactogenic administration protocols (LRPs) based on slow infusion. It is suggested that consideration of CARPA and the use of LRPs might lead to useful new additions to the management of high‐risk IV‐iron patients.

Opening cyclic or polycyclic alkanes by carbon–carbon bond cleavage can be a good route for the valorization of certain alkanes. A key point of any proposed catalytic system would be the catalyst poisoning. In this paper, we determine experimentally the influence of the time on stream on the distribution of products when 1,4-dimethylcyclohexane is introduced together with hydrogen over a Ir/SiO 2 catalyst. A simplistic model of selective catalyst poisoning is proposed to explain the influence of the time on stream on the activity and product selectivity.

Introduction Le carcinome neuro-endocrine de Merckel est une tumeur rare associee au polyomavirus de Merckel dont l’incidence est en augmentation avec le vieillissement de la population. Il atteint habituellement la tete et le cou de sujets âges. Les facteurs de risque identifies sont l’exposition solaire et l’immunosuppression. Nous rapportons le cas d’une patiente ayant un carcinome de Merckel de stade IIIB en remission apres 11 mois de traitement par analogue de la somatostatine. Observations Madame V., 87 ans, avait pour principaux antecedents un cancer de l’endometre en remission depuis 2009, une HTA et une obesite morbide. La patiente presentait en juillet 2014, une lesion de la jambe gauche. La biopsie exerese de la lesion identifiait un carcinome de Merckel pour lequel une reprise chirurgicale et une radiotherapie adjuvante locale etaient realisees. Cependant 3 mois plus tard, la patiente presentait une recidive locoregionale de stade IIIB, avec des nodules sous-cutanes et des adenomegalies inguinales gauche confirmees par imagerie. La patiente refusant toute intervention, biopsie ou chirurgie ou radiotherapie, supplementaire, un traitement par analogue de la somatostatine (lanreotide, Somatuline LP®, 120 mg/mois en sous-cutane) etait propose. Les lesions cutanees diminuaient progressivement et les adenomegalies disparaissaient apres 6 mois de traitement. Apres 11 mois de traitement, la patiente ne presentait plus de lesion clinique et paraclinique (scanner corps entier normal). La biopsie cutanee ne retrouvait pas de lesion residuelle tumorale. Aucun effet indesirable n’etait signale. Le traitement mensuel par lanreotide est toujours en cours. Discussion Les recepteurs de la somatostatine 2A et 5A ont ete recemment detectes dans environ 76 % des carcinomes de Merckel explores (Gardair et al., 2015), et plusieurs cas de remissions prolongees ont ete rapportes avec les analogues de la somatostatine (Fakiha et al., 2010), Conclusion Notre observation suggere que les analogues de la somatostatine pourraient constituer une alternative therapeutique interessante pour le traitement des carcinomes neuro-endocrines de Merkel inoperables et/ou metastatiques, en particulier chez les sujets âges ayant de nombreuses comorbidites et ne souhaitant pas de traitements lourds.

This study treats the synthesis of silica-supported iridium metal particles by several different methods. Iridium trisacetylacetonate was first deposited on silica either by sublimation or by impregnation from a toluene solution. Infrared study showed no difference between the methods, each of which produced Ir(acac)3 physisorbed at the surface. The physisorbed precursor was transformed by two methods and the reactions were followed by in situ infrared spectroscopy. In the first method, the solid was first heated under a flow of oxygen to produce surface iridium oxide, which was then reduced under hydrogen at different temperatures to provide iridium metal support particles. In the second method a physisorbed precursor was directly reduced under a hydrogen flow. Electron microscopy showed that both methods produced narrow distributions of metallic particle sizes between 1 and 5 nm, but for the first method very large metallic aggregates were also observed. The chemisorption of hydrogen, oxygen, and CO on the resultant supported metal materials at 25°C was investigated as a means of determining the dispersion of the samples. A discrepancy between the dispersions deduced from chemisorption of H2, O2, and CO and from electron microscopy on the resultant supported metal materials was tentatively interpreted as an indication that some very small Ir particles, present on the silica surface, were not detected.

Haemodialysis, a life-saving treatment extending the life of many people for up to more than 20 years, causes acute complications and symptoms and long-term uraemic complications affecting the patient's morbidity and mortality. These inadequacies have been attributed not only to the dialysate composition but also to the membrane. In evaluating the benefits of biocompatible membranes reported in the literature, we have taken into account nutritional aspects, infections, cardiovascular effects, long-term effects, the potential renoprotective effect and patients with acute renal failure survival. In spite of the wide literature on biological effects of biocompatibility of dialytic membranes, stressing the superiority of synthetic membranes, proven causal relationships between clinical diseases and biological reactions are scarce and the true impact of biological effects on the clinical state is still debatable. The results of prospective randomized controlled trials in patients with chronic renal failure are conflicting. Large trials with long follow-up times are needed to further clarify the effects of biocompatible membranes and different treatment modalities on morbidity and mortality of patients on chronic replacement therapy, but these trials are difficult because of randomization and high patient drop-out rates. However, the results of the two controlled trials on patients with acute renal failure stress the importance of biocompatible membranes. Only cost is in favour of the use of cuprophane membranes, especially in patients with acute renal failure.