Wetting properties of porous high temperature polymer electrolyte fuel cells materials with phosphoric acid.

Wetting properties of phosphoric acid in porous materials of high temperature fuel cells (HT-PEFC), operating at around 160 °C, are important for cell performance and durability, but the underlying wetting parameters have been unknown so far. Therefore, the influence of phosphoric acid temperature and concentration on the wetting behavior of porous HT-PEFC materials is investigated. The acid filling of gas diffusion and catalyst layers as function of capillary pressure is monitored with X-ray tomographic microscopy under the well defined conditions of an ex situ set-up at temperatures up to 160 °C. For the wetting of gas diffusion layers, with pore sizes in the order of few 10 µm, two opposing trends are shown. With increasing phosphoric acid concentration, less capillary pressure is required, while with increasing temperatures, higher capillary pressures are needed for filling up to a given saturation. The same trends are also found for the contact angle of phosphoric acid on PTFE. A higher contact angle is observed with increasing temperature while increasing the phosphoric acid concentration decreases the contact angle. As both trends are of a similar order of magnitude, the wetting behavior of concentrated (113 wt%) phosphoric acid at 160 °C is astonishingly similar to the wetting behavior of water at room temperature. Another important property for HT-PEFC operation is the filling of cracks in the catalyst layer, which have widths up to 100 µm. For large cracks (>60 µm), a capillary pressure of only 15 mbar was deduced from the measurement, increasing to 30 mbar for cracks between 20 and 60 µm. This, for the first time, allows for assessing the membrane phosphoric acid pressure during fuel cell operation. This can guide the development of improved porous materials for HT-PEFC.

Iron deficiency and thrombocytosis.

According to many textbooks, iron deficiency (ID) is associated with reactive thrombocytosis. In this study, we aimed to investigate the correlation between serum ferritin levels and platelet counts in a large cohort of healthy blood donors. We included all whole blood and apheresis donors aged 18 years or older with at least one ferritin measurement and one platelet count performed at the same visit between 1996 and 2014. A total of 130 345 blood counts and ferritin measurements obtained from 22 046 healthy donors were analysed. Overall, no correlation between serum ferritin and platelet count was observed (r = -0.03, ρ = 0.04 for males, and r = 0.01, ρ = -0.02 for females, respectively). Associations remained clinically negligible after adjusting for age, time since previous blood donation, number of donations and restricting the analysis to ferritin deciles. In this large, retrospective single-centre study, correlations between low ferritin and platelet count in a large and homogeneous cohort of healthy donors were negligible. Further studies in patients with more severe anaemia and patients with inflammation are warranted.

Synergistic effect of sorafenib and cGvHD in patients with high-risk FLT3-ITD+AML allows long-term disease control after allogeneic transplantation.

The multikinase inhibitor sorafenib has shown a strong anti-leukemic effect in FMS-like tyrosine kinase 3 (FLT3)-mutated acute myeloid leukemia (AML); however, remission is often transient. To better understand the role of sorafenib, we performed a retrospective analysis of all patients who received sorafenib in combination with allogeneic hematopoietic stem cell transplantation (HSCT) at our center. Seventeen patients with FLT3-ITD positive AML were treated with sorafenib in combination with allogeneic HSCT. Seven patients received sorafenib therapy pre- and posttransplant, and 10 patients were given sorafenib only posttransplant. Median duration of sorafenib treatment was 13 months (range 1-42); median dose was 600 mg (range 100-1200). Fourteen patients (82 %) achieved a complete remission (CR), while 5 patients (29 %) eventually developed progressive disease. Developing chronic graft-versus-host disease (GvHD) had a strong protective influence on the risk of sorafenib resistance (p = 0.028, HR 0.08, 95 % CI 0.01-0.76). In a total of 8 patients, sorafenib had to be stopped, paused or dose-reduced due to toxicity. In 5 patients with pronounced toxicity, we switched to an alternating dosing schedule with 1 month on/1 month off sorafenib. These patients subsequently remained in sustained complete molecular remission, with a median follow-up of 20 months. Our data indicate that sorafenib can achieve high rates of sustained remission in high-risk patients treated in combination with HSCT.

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) directly from positive blood culture flasks allows rapid identification of bloodstream infections in immunosuppressed hosts.

INTRODUCTION: In immunosuppressed hosts, rapid identification of microorganisms of bloodstream infections is crucial to ensuring effective antimicrobial therapy. Conventional culture requires up to 72 h from sample collection to pathogen identification. METHODS: We used the SepsiTyper Kit and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF; Microflex, Bruker) directly from positive blood culture (BacT/ALERT 3D, FN/FA vials; bioMérieux) in comparison to standard culture methodology (VITEK 2; bioMérieux) for species identification. RESULTS: A total of 62 consecutive positive blood cultures from immunosuppressed patients (solid organ or hematopoietic transplant recipients, or with febrile neutropenia) were analyzed. Culture yielded gram-negative bacteria (GNB) in 27/62 (43.5%) and gram-positive (GPB) in 35/62 (56.5%) vials. For GNB, the predominant species identified by MALDI-TOF and confirmed by VITEK were Escherichia coli (16/16 correctly identified) and Enterobacter cloacae (4/4), with a sensitivity and specificity of 92.6% and 100%, respectively. For GPB, predominant species were Staphylococcus aureus (3/3), coagulase-negative staphylococci (12/24), and Enterococcus faecium (6/6) with a sensitivity of 100%, 60%, and 100%, respectively. The median time from blood collection to species identification was 27.4 h with MALDI-TOF identification and 46.6 h with conventional methodology. CONCLUSION: Using MALDI-TOF directly from positive blood cultures allowed a shorter time to identification with high sensitivity and specificity in immunosuppressed patients.

Combination therapy for multidrug-resistant cytomegalovirus disease.

Multidrug-resistant (MDR) cytomegalovirus (CMV) emerged after transient responses to ganciclovir, foscarnet, and cidofovir in a CMV-seropositive recipient who underwent allogeneic hematopoietic stem cell transplantation from a CMV-seronegative donor. Experimental treatments using leflunomide and artesunate failed. Re-transplantation from a CMV-seropositive donor supported by adoptive transfer of pp65-specific T cells and maribavir was followed by lasting suppression. This case illustrates that successful MDR CMV therapy may require individualized multidisciplinary approaches.

[Sleeve gastrectomy as a revision procedure for failed gastric banding]. / Schlauchmagenbildung als Revisionseingriff nach Magenbandversagen.

The number of bariatric surgical procedures is still increasing in Germany and also worldwide. According to the German quality assurance study of surgical treatment of obesity, the laparoscopic adjustable gastric banding (LAGB) was the most common bariatric operation with a total of 678 cases between 2004 and 2006 in Germany. In the meantime a high rate of LAGB treatment failures has been reported, so that a high rate of revisional bariatric operations is required. But still the question is open which bariatric procedure can be recommended. The aim of this study is to report the results and follow-up of conversion of failed LAGB to laparoscopic sleeve gastrectomy (LSG). Between 8/2008 and 4/2012 39 patients (31♀/8♂) with a mean age of 43.7 ± 7.8 (26-61) years and a BMI of 47.1 ± 9.1 (30.4 to 67.4) kg/m² had revisional surgery for converting a failed LAGB to LSG. The indications for conversion were dysphagia (38.5 %), weight regain (33.3 %), band slippage (17.9 %), band erosion (5.1 %), band defect (2.6 %) as well as band sepsis (2.6 %). 19 procedures were performed as a one-stage operation and 20 procedures as a two-stage operation. The average operating time was 129 ± 49 (50-312) min. The complication rate was 7.7 %. There were one proximal leak, one gastric sleeve stenosis and one pronounced wound infection. The percent excess weight loss was 23 %, 39 %, 51 %, 52 %, 60 % and 46 % after 1, 3, 6, 12, 24 and 36 months follow- up, respectively. Converting a failed LAGB into a LSG is a revision procedure with low complication rate and promising results, which can be performed as a two-stage as well as a one-stage procedure.

Solid-organ transplantation in older adults: current status and future research.

An increasing number of patients older than 65 years are referred for and have access to organ transplantation, and an increasing number of older adults are donating organs. Although short-term outcomes are similar in older versus younger transplant recipients, older donor or recipient age is associated with inferior long-term outcomes. However, age is often a proxy for other factors that might predict poor outcomes more strongly and better identify patients at risk for adverse events. Approaches to transplantation in older adults vary across programs, but despite recent gains in access and the increased use of marginal organs, older patients remain less likely than other groups to receive a transplant, and those who do are highly selected. Moreover, few studies have addressed geriatric issues in transplant patient selection or management, or the implications on health span and disability when patients age to late life with a transplanted organ. This paper summarizes a recent trans-disciplinary workshop held by ASP, in collaboration with NHLBI, NIA, NIAID, NIDDK and AGS, to address issues related to kidney, liver, lung, or heart transplantation in older adults and to propose a research agenda in these areas.

Human metapneumovirus infection after allogeneic hematopoietic stem cell transplantation.

BACKGROUND: The clinical characteristics of human metapneumovirus (hMPV)-associated lower respiratory tract infection (LRTI) after allogeneic hematopoietic stem cell transplantation (HSCT) is not well described. We describe the clinical course in eight HSCT recipients suffering from hMPV infection. METHODS: We prospectively included all patients with hMPV-associated LRTI after allogeneic HSCT during a period of 1 year. hMPV was diagnosed by multiplex polymerase chain reaction (PCR) from bronchoalveolar lavage (BAL). RESULTS: Eight patients with hMPV-associated LRTI were identified from 93 BAL samples. Three of the eight patients had co-infections with other pathogens. The median age of the patients was 45 years [interquartile range (IQR) 36.8-53.5], the median time posttransplant was 473 days (IQR 251-1,165), 5/8 patients had chronic graft-versus-host disease (cGvHD), and 6/8 patients received immunosuppression. Chest computed tomography (CT) scanning showed a ground-glass pattern in 7/8 patients. Seven of eight patients required hospitalization due to severe symptoms and hypoxemia. All were treated with intravenous immunoglobulin (IVIG), which was combined with oral ribavirin in six patients. The mortality rate was 12.5 % (1/8). CONCLUSIONS: hMPV-associated LRTI in allogeneic HSCT recipients are not uncommon and present with unspecific respiratory symptoms, ground-glass pattern in CT scanning, and co-infection.

Basic characteristics and safety of donation in related and unrelated haematopoietic progenitor cell donors - first 10 years of prospective donor follow-up of Swiss donors.

Since July 2007 prospective life-long follow-up (FU) for unrelated (URD) and related donors (RD) is mandatory in Switzerland and data on every allogeneic haematopoietic progenitor cell (HPC) donation are collected prospectively. We report the real-world experience of HPC donation during a 10-year study period (01.07.2007-30.06.2017) with basic characteristics and FU data. 1105 donors underwent 1155 HPC donation procedures. Eighty percent of first donations performed by 802 (73%) RDs and 303 (27%) URDs were peripheral blood stem cells (PBSC), 20% bone marrow (BM). Male donors were over-represented as URD (60% male vs 40% female). Main differences between RDs and URDs concerned age and pre-existing health disorders. RDs were significantly older at first donation (median age 48 years) compared to URD (34 years, p < 0.0001) and had more pre-existing health problems: 25% vs 9% in URD (p < 0.0001). No fatal complications occurred, collection related severe adverse events (SAE) after first donation were not significantly different between groups (RD 1.2%, URD 0.99%), incidence rates for neoplastic and autoimmune diseases did not exceed the rates of the general population. RDs are a more heterogeneous and potentially more vulnerable group, but if donor evaluation is performed appropriately, HPC donation is still safe.

Prevalence of untreated and uncontrolled cardiovascular risk factors in survivors of allogeneic cell transplantation.

Cardiovascular risk factors (CVRF) are frequent among long-term survivors after allogeneic hematopoietic cell transplantation (HCT) but prospective data on CVRF are sparse. We conducted a cross-sectional single center study including patients who underwent a first HCT mostly for hematologic malignancies at our center between 2000 and 2016, surviving at least 1 year. 260 patients (median age 54 years [range 19-78], 40% female) who were median 6 years (range 1-16) after transplantation were included. Most patients (232, 89%) had peripheral blood stem cell transplantation. cGVHD was present in 41% at the time of study inclusion. Prevalence of hypertension, dyslipidemia, and diabetes was 58%, 63% and 9%, respectively. Untreated hypertension, dyslipidemia and diabetes was found in 15%, 35% and 2%. Among patients with treated hypertension, 38% did not have blood pressure controlled to levels ≤140/90 mmHg. 36% patients under lipid-lowering therapy did not reach their LDL target. Multivariable logistic regression analyses showed that age and diabetes increased the likelihood for hypertension and dyslipidemia, whereas body mass index, cGVHD and male sex predicted hypertension only. In summary, CVRF in long-term survivors are frequent and persisting after cessation of immunosuppression. A large proportion of CVRF are either untreated or uncontrolled.

Current practice in nutrition after allogeneic hematopoietic stem cell transplantation - Results from a survey among hematopoietic stem cell transplant centers.

BACKGROUND: Allogeneic hematopoietic stem cell transplantation (alloHSCT) is frequently associated with impaired oral intake and malnutrition, which potentially increases morbidity and mortality. Therefore, nutrition is one of the major challenges in the post-transplant period. METHODS: To document the current clinical approach in nutritional treatment, we designed a questionnaire concerning the current practice in nutrition after alloHSCT and distributed it to German speaking centers performing alloHSCT in Germany, Austria and Switzerland between November 2018 and March 2020. Twenty-eight (39%) of 72 contacted centers completed the survey, 23 from Germany, two from Austria and three from Switzerland, representing 50% of alloHSCT activity within the participating countries in 2018. RESULTS: All centers reported having nutritional guidelines for patients undergoing alloHSCT, whereby 86% (n = 24) provided a low-microbial diet during the neutropenic phase. The criteria to start parenteral nutrition (PN) directly after alloHSCT seemed to be consistent, 75% (n = 21) of the corresponding centers started PN if the oral nutritional intake or the bodyweight dropped below a certain limit. In the setting of intestinal graft-versus-host disease (GvHD) the current practice appeared to be more heterogenous. About 64% (n = 18) of the centers followed a special diet, added food stepwise modulated by GvHD symptoms, while only four centers regularly stopped oral intake completely (intestinal GvHD grade >1). Half of the centers (54%, n = 15) applied a lactose-free diet, followed by 43% (n = 12) which provided fat- and 18% (n = 5) gluten-free food in patients with intestinal GvHD. Supplementation of micronutrients in acute intestinal GvHD patients was performed by 54% (n = 15) of the centers, whereas vitamin D (89%, n = 25) and vitamin B12 (68%, n = 19) was added regularly independently of the presence of GvHD. Only 5 (18%) participating centers ever observed a food-associated infection during hospitalization, whereas food-associated infections were reported to occur more often in the outpatient setting (64%, n = 18). CONCLUSION: The survey documented a general consensus about the need for nutritional guidelines for patients undergoing alloHSCT. However, the nutritional treatment in clinical practice (i.e. lactose-, gluten- or fat-free in intestinal GvHD) as well as the use of food supplements was very heterogeneous. In line with current general recommendations the centers seemed to focus on safe food handling practice rather than providing a strict neutropenic diet. More high-quality data are required to provide evidence-based nutrition to patients during and after alloHSCT.

Outcome of influenza infections in outpatients after allogeneic hematopoietic stem cell transplantation.

BACKGROUND: Influenza can cause significant morbidity and mortality in patients after hematopoietic stem cell transplantation (HSCT). The diagnostic methods and antiviral treatment have scarcely been investigated. METHODS: We retrospectively identified influenza-infected patients with upper or lower respiratory tract infection (RTI) diagnosed by culture and polymerase chain reaction (PCR) testing between November 2007 and April 2008. Treatment with oseltamivir 75 mg twice daily and serial nasal swabs were performed at the discretion of the treating physician. RESULTS: We identified 21 influenza infections in 19 patients: 19 with upper RTI and 2 with lower RTI. At diagnosis, all 21 samples were positive for PCR with a median influenza load of 5.9 log(10) copies/mL. Culture was positive in 14 (67%) patients. Influenza A virus was diagnosed in 8 (38%) episodes and influenza B virus in 13 (62%) episodes. Two patients were sequentially infected by influenza A, followed by B after 38 and 47 days, respectively. Eighteen (86%) patients were treated with oseltamivir for 11 days (median, interquartile range [IQR]: 8-14). No progression to lower RTI or mortality occurred. Shedding persisted for 12 days (median, IQR: 8-13). Absolute lymphocyte count at diagnosis correlated inversely with shedding of the virus (P<0.001). CONCLUSIONS: Oseltamivir is well tolerated and may reduce mortality of influenza virus-infected patients after HSCT. PCR may help to optimize diagnosis and to monitor treatment strategies.

Impaired B-cell reconstitution in lymphoma patients undergoing allogeneic HSCT: an effect of pretreatment with rituximab?

Allogeneic hematopoietic SCT (HSCT) is increasingly considered an option in refractory or relapsing lymphoma. Today, most patients with B-cell lymphoma are treated with the monoclonal anti-CD20 antibody rituximab before HSCT. We hypothesized that prior therapy with rituximab might alter immune reconstitution after allogeneic transplantation due to in vivo depletion of B cells at the time of graft infusion. We studied B-cell immune reconstitution in 12 patients with lymphoma receiving rituximab 1-12 months before HSCT. Compared to an age- and sex-matched population of patients transplanted for myeloid malignancies, lymphoma patients with rituximab pretreatment showed significantly reduced B-cell counts at time of HSCT at +3, +6 and +12 months; B-cell counts reached values comparable to controls only 24 months after HSCT. In parallel, levels of immunoglobulins were markedly reduced for up to 2 years post transplant in patients with prior rituximab treatment. Two patients suffered from severe late bacterial infections to which the impaired humoral immunity may have contributed. In contrast, T- and NK-cell reconstitution was not different compared to control patients.In conclusion, B-cell reconstitution can be significantly delayed in allogeneic HSCT recipients with prior rituximab treatment. Rituximab appears to have clinical consequences beyond the immediate early post-transplant period.

A role for alpha-adrenergic receptors in abnormal insulin secretion in diabetes mellitus.

To determine whether endogenous alpha-adrenergic activity contributes to abnormal insulin secretion in nonketotic, hyperglycemic, diabetic patients, alpha-adrenergic blockade was produced in normal and diabetic subjects. The diabetics had a significantly (P less than 0.01) greater increase in circulating insulin 1 h after an intravenous phentolamine infusion than did the normal subjects. During the phentolamine infusion, there was also a significant augmentation of acute insulin responses to intravenous glucose (20 g) pulses in normal subjects (P less than 0.05) and diabetics (P less than 0.02); this augmentation was fivefold greater in the diabetics. Simultaneous treatment with the beta-adrenergic blocking agent, propranolol, did not alter these findings. Thus a role for exaggerated endogenous alpha-adrenergic activity in abnormal insulin secretion of the diabetic subjects is suggested. To determine whether this alpha-adrenergic activity might be related to elevated circulating catecholamines, total plasma-catecholamine levels were compared in normal and nonketotic diabetic subjects given intravenous glucose pulses. These levels were significantly greater (P less than 0.02) in the diabetic compared to the normal group before the glucose pulse, and increased significantly in both groups (P less than 0.02 and less than 0.001, respectively) after the pulse. These data suggest that excessive catecholamine secretion may lead to an abnormal degree of endogenous alpha-adrenergic activity, which contributes to defective insulin secretion in diabetic subjects.

Diminished B cell secretory capacity in patients with noninsulin-dependent diabetes mellitus.

In order to assess whether patients with noninsulin-dependent diabetes mellitus (NIDDM) possess normal insulin secretory capacity, maximal B cell responsiveness to the potentiating effects of glucose was estimated in eight untreated patients with NIDDM and in eight nondiabetic controls. The acute insulin response to 5 g intravenous arginine was measured at five matched plasma glucose levels that ranged from approximately 100-615 mg/dl. The upper asymptote approached by acute insulin responses (AIRmax) and the plasma glucose concentration at half-maximal responsiveness (PG50) were estimated using nonlinear regression to fit a modification of the Michaelis-Menten equation. In addition, glucagon responses to arginine were measured at these same glucose levels to compare maximal A cell suppression by hyperglycemia in diabetics and controls. Insulin responses to arginine were lower in diabetics than in controls at all matched glucose levels (P less than 0.001 at all levels). In addition, estimated AIRmax was much lower in diabetics than in controls (83 +/- 21 vs. 450 +/- 93 microU/ml, P less than 0.01). In contrast, PG50 was similar in diabetics and controls (234 +/- 28 vs. 197 +/- 20 mg/dl, P equals NS) and insulin responses in both groups approached or attained maxima at a glucose level of approximately 460 mg/dl. Acute glucagon responses to arginine in patients with NIDDM were significantly higher than responses in controls at all glucose levels. In addition, although glucagon responses in control subjects reached a minimum at a glucose level of approximately 460 mg/dl, responses in diabetics declined continuously throughout the glucose range and did not reach a minimum. Thus, A cell sensitivity to changes in glucose level may be diminished in patients with NIDDM. In summary, patients with NIDDM possess markedly decreased maximal insulin responsiveness to the potentiating effects of glucose. Such a defect indicates the presence of a reduced B cell secretory capacity and suggests a marked generalized impairment of B cell function in patients with NIDDM.

Glucagon, catecholamine and pancreatic polypeptide secretion in type I diabetic recipients of pancreas allografts.

Successful pancreas transplantation in type I diabetic patients restores normal fasting glucose levels and biphasic insulin responses to glucose. However, virtually no data from pancreas recipients are available relative to other islet hormonal responses or hormonal counterregulation of hypoglycemia. Consequently, glucose, glucagon, catecholamine, and pancreatic polypeptide responses to insulin-induced hypoglycemia and to stimulation with arginine and secretin were examined in 38 diabetic pancreas recipients, 54 type I diabetic nonrecipients, and 26 nondiabetic normal control subjects. Glucose recovery after insulin-induced hypoglycemia in pancreas recipients was significantly improved. Basal glucagon levels were significantly higher in recipients compared with nonrecipients and normal subjects. Glucagon responses to insulin-induced hypoglycemia were significantly greater in the pancreas recipients compared with nonrecipients and similar to that observed in control subjects. Glucagon responses to intravenous arginine were significantly greater in pancreas recipients than that observed in both the nonrecipients and normal subjects. No differences were observed in epinephrine responses during insulin-induced hypoglycemia. No differences in pancreatic polypeptide responses to hypoglycemia were observed when comparing the recipient and nonrecipient groups, both of which were less than that observed in the control subjects. Our data demonstrate significant improvement in glucose recovery after hypoglycemia which was associated with improved glucagon secretion in type I diabetic recipients of pancreas transplantation.