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Objectives: To assess the feasibility of using an at home breath-sampling technique in patients referred for breath hydrogen testing, and to determine the likelihood for a positive breath hydrogen test (BHT) based on whether the ordering physician is a gastroenterologist or general practitioner.Methods: Breath samples were collected via a nasal prong technique and stored in a collection kit. The breath samples were then analyzed using the Quintron microlyzer. A positive BHT was defined as a rise in hydrogen gas concentration of more than 10 ppm above baseline.Results: Over a six-year period (1996 to 2002), 372 consecutive BHTs were per-formed, 40 in patients younger than 5 years, 201 in patients aged 5 to 18 years, and 131 in patients older than 18 years. Overall, 45 breath samples (12%) were considered unsatisfactory. Patients younger than 5 years (38%) had a significantly higher (P<0.001) number of unsatisfactory breath samples than the other 2 age groups (5-18 years old [10%], > 18 years old [7%]). Of the 328 satisfactory BHTs, 162 (49%) were positive for either lactose intolerance (90%) or small bowel bacterial overgrowth (10%). The likelihood in obtaining a positive BHT was significantly (P<0.001) higher if the referring physician was a gastroenterologist. Our analysis also suggests a potential cost savings in having gastroenterologists screen patients for suspected lactose intolerance or bacterial overgrowth prior to ordering breath hydrogen testing.Conclusions: The nasal prong technique is a feasible method of performing the BHT at home in children younger than 5 years of age. In the very young (<5 years of age), new and innovative breath sampling techniques are needed to make home testing practical. Since gastroenterologists are more selective than general practitioners in requesting BHTs, the potential cost savings may offset the added cost of a patient referral. [ABSTRACT FROM AUTHOR]

6-Mercaptopurine (6-MP) and its prodrug azathioprine (AZA) are well known for their lymphocytotoxic and bone marrow suppressive effects in the management of patients with leukemia. Although their immunosuppressive properties are mediated by the active AZA antimetabolite 6-thioguanine (6-TG), its mechanism of action is largely unknown. In IBD, a significant inverse correlation has been shown between erythrocyte 6-TG metabolite levels and disease activity, further supporting the proposed immunosuppressive role for 6-TG. Since leukocytes possess quantitatively different purine metabolic pathways compared to erythrocytes, this study aims to measure lymphocyte DNA 6-TG metabolites and correlate levels with the INF-gamma and IL-10 cytokine profile in patients with Crohn's disease (CD). Forty-six adult patients with CD, either naive (17) or on long-term (>4-month) AZA therapy (29), had erythrocyte and lymphocyte DNA 6-TG levels measured by reverse-phase HPLC under UV detection (6-TG, 340 nm). Lymphocyte DNA 6-TG was expressed as picomoles per milligram of DNA. Lymphocyte DNA 6-TG metabolite levels were correlated with INF-gamma and IL-10 cytokine profiles using the OptEIA kit (Pharmigen). Lymphocyte DNA 6-TG metabolite levels correlate with erythrocyte 6-TG levels (P < 0.03) but not total patient leukocyte levels. Erythrocyte 6-TG metabolite levels correlated (P < 0.01) inversely with INF-gamma but not IL-10 cytokine levels. This study suggests a preferential dampening of the TH1 response on exposure to 6-TG and a possible immunosuppressive mechanism of action for AZA. Future studies are needed to determine if cytokine profiles can be used to predict recalcitrant CD to AZA therapy. [ABSTRACT FROM AUTHOR]

In the era of highly active novel agents for multiple myeloma (MM), the role, ideal timing, and impact of transplantation on further therapy after relapse remains a matter of debate. The impact of prior transplantation on treatment benefit from monoclonal antibodies in patients with relapsed/refractory MM (RRMM) is largely unknown. Few Phase 3 studies of monoclonal antibody combinations with proteasome inhibitors or immunomodulatory agents have reported outcomes according to transplantation status. This subgroup analysis examined efficacy and safety in patients from the Phase 3 IKEMA study with and without previous transplantation. IKEMA (NCT03275285) was a randomized, open-label, multinational, parallel-group Phase 3 study that investigated isatuximab (Isa), an anti-CD38 monoclonal antibody, combined with carfilzomib and dexamethasone (Isa-Kd; experimental group) versus Kd (control group) in 302 patients with RRMM and 1 to 3 prior lines of therapy. Patients were randomized in a 3:2 ratio to either Isa-Kd or Kd, with stratification by number of prior lines (1 versus more than 1) and Revised International Staging System (R-ISS) stage (I or II versus III versus not classified). Treatment was given until progressive disease, unacceptable adverse events, or patient choice. Of the 302 randomized patients in IKEMA, 185 (61.3%) had received a prior transplant, comprising 116 of 179 (64.8%) patients in the Isa-Kd arm and 69 of 123 (56.1%) patients in the Kd arm. After a median follow-up of 20.6 months, median progression-free survival (PFS) in patients with prior transplant was not reached with Isa-Kd versus 19.15 months with Kd (hazard ratio [HR] = 0.60; 99% confidence interval [CI], 0.31-1.16). After a median follow-up of 20.8 months, median PFS in patients without prior transplant was not reached with Isa-Kd versus 18.99 months with Kd (HR = 0.44; 99% CI, 0.18-1.05). The overall response rate in patients with prior transplant was 87.9% (Isa-Kd) versus 85.5% (Kd). More patients in the Isa-Kd arm achieved a complete response or better compared with the Kd arm (43.1% versus 29.0%). The overall response rate in patients without prior transplant was 84.1% (Isa-Kd) versus 79.6% (Kd). More patients in the Isa-Kd arm achieved a complete response or better compared with the Kd arm (33.3% versus 25.9%). The minimal residual disease negativity rate was higher with Isa-Kd versus Kd in patients with (31.9% versus 13.0%) and without prior transplantation (25.4% versus 13.0%). In patients with prior transplant, Grade 3 or higher treatment-emergent adverse events (TEAEs) were more common with Isa-Kd; however, no increases in serious TEAEs or definitive treatment discontinuations were seen versus Kd. Among patients without prior transplant, serious treatment-related TEAEs were similar, and there were fewer TEAEs leading to definitive discontinuation with Isa-Kd. The most common Grade 3 or higher TEAEs in patients with and without prior transplant were hypertension and pneumonia. For patients who underwent prior transplantation, Isa-Kd is an effective treatment option. Overall, these data demonstrate that Isa-Kd represents a standard of care for patients with RRMM, regardless of prior transplant status., (Copyright © 2022. Published by Elsevier Inc.)

Zika virus is a mosquito-borne flavivirus known to cause severe birth defects and neuroimmunological disorders. We have previously demonstrated that mosquito transmission of Zika virus decreases with temperature. While transmission was optimized at 29°C, it was limited at cool temperatures (<22°C) due to poor virus establishment in the mosquitoes. Temperature is one of the strongest drivers of vector-borne disease transmission due to its profound effect on ectothermic mosquito vectors, viruses, and their interaction. Although there is substantial evidence of temperature effects on arbovirus replication and dissemination inside mosquitoes, little is known about whether temperature affects virus replication directly or indirectly through mosquito physiology. In order to determine the mechanisms behind temperature-induced changes in Zika virus transmission potential, we investigated different steps of the virus replication cycle in mosquito cells (C6/36) at optimal (28°C) and cool (20°C) temperatures. We found that the cool temperature did not alter Zika virus entry or translation, but it affected genome replication and reduced the amount of double-stranded RNA replication intermediates. If replication complexes were first formed at 28°C and the cells were subsequently shifted to 20°C, the late steps in the virus replication cycle were efficiently completed. These data suggest that cool temperature decreases the efficiency of Zika virus genome replication in mosquito cells. This phenotype was observed in the Asian lineage of Zika virus, while the African lineage Zika virus was less restricted at 20°C. IMPORTANCE With half of the human population at risk, arboviral diseases represent a substantial global health burden. Zika virus, previously known to cause sporadic infections in humans, emerged in the Americas in 2015 and quickly spread worldwide. There was an urgent need to better understand the disease pathogenesis and develop therapeutics and vaccines, as well as to understand, predict, and control virus transmission. In order to efficiently predict the seasonality and geography for Zika virus transmission, we need a deeper understanding of the host-pathogen interactions and how they can be altered by environmental factors such as temperature. Identifying the step in the virus replication cycle that is inhibited under cool conditions can have implications in modeling the temperature suitability for arbovirus transmission as global environmental patterns change. Understanding the link between pathogen replication and environmental conditions can potentially be exploited to develop new vector control strategies in the future.

Sirolimus has activity against acute lymphoblastic leukemia (ALL) in xenograft models and efficacy in preventing acute graft-versus-host disease (aGVHD). We tested whether addition of sirolimus to GVHD prophylaxis of children with ALL would decrease aGVHD and relapse. Patients were randomized to tacrolimus/methotrexate (standard) or tacrolimus/methotrexate/sirolimus (experimental). The study met futility rules for survival after enrolling 146 of 259 patients. Rate of Grade 2-4 aGVHD was 31% vs 18% (standard vs experimental, P = .04), however, grade 3-4 aGVHD was not different (13% vs 10%, P = .28). Rates of veno-occlusive disease (VOD) and thrombotic microangiopathy (TMA) were lower in the nonsirolimus arm (9% vs 21% VOD, P = .05; 1% vs 10% TMA, P = .06). At 2 years, event free survival (EFS) and overall survival (OS) were 56% vs 46%, and 65% vs 55% (standard vs experimental), respectively (P = .28 and .23). Multivariate analysis showed increased relapse risk in children with ≥0.1% minimal residual disease (MRD) pretransplant, and decreased risk in patients with grades 1-3 aGVHD (P = .04). Grades 1-3 aGVHD were associated with improved EFS (P = .02), whereas grade 4 aGVHD and extramedullary disease at diagnosis led to inferior OS. Although addition of sirolimus decreased aGVHD, survival was not improved. This study is registered with ClinicalTrials.gov as #NCT00382109.

Blast-related traumatic brain injury (TBI) has been one of the "signature injuries" of the wars in Iraq and Afghanistan. However, neuroimaging studies in concussive 'mild' blast-related TBI have been challenging due to the absence of abnormalities in computed tomography or conventional magnetic resonance imaging (MRI) and the heterogeneity of the blast-related injury mechanisms. The goal of this study was to address these challenges utilizing single-subject, module-based graph theoretic analysis of resting-state functional MRI (fMRI) data. We acquired 20min of resting-state fMRI in 63 U.S. military personnel clinically diagnosed with concussive blast-related TBI and 21 U.S. military controls who had blast exposures but no diagnosis of TBI. All subjects underwent an initial scan within 90days post-injury and 65 subjects underwent a follow-up scan 6 to 12months later. A second independent cohort of 40 U.S. military personnel with concussive blast-related TBI served as a validation dataset. The second independent cohort underwent an initial scan within 30days post-injury. 75% of the scans were of good quality, with exclusions primarily due to excessive subject motion. Network analysis of the subset of these subjects in the first cohort with good quality scans revealed spatially localized reductions in the participation coefficient, a measure of between-module connectivity, in the TBI patients relative to the controls at the time of the initial scan. These group differences were less prominent on the follow-up scans. The 15 brain areas with the most prominent reductions in the participation coefficient were next used as regions of interest (ROIs) for single-subject analyses. In the first TBI cohort, more subjects than would be expected by chance (27/47 versus 2/47 expected, p<0.0001) had 3 or more brain regions with abnormally low between-module connectivity relative to the controls on the initial scans. On the follow-up scans, more subjects than expected by chance (5/37, p=0.044) but fewer subjects than on the initial scans had 3 or more brain regions with abnormally low between-module connectivity. Analysis of the second TBI cohort validation dataset with no free parameters provided a partial replication; again more subjects than expected by chance (8/31, p=0.006) had 3 or more brain regions with abnormally low between-module connectivity on the initial scans, but the numbers were not significant (2/27, p=0.276) on the follow-up scans. A single-subject, multivariate analysis by probabilistic principal component analysis of the between-module connectivity in the 15 identified ROIs, showed that 31/47 subjects in the first TBI cohort were found to be abnormal relative to the controls on the initial scans. In the second TBI cohort, 9/31 patients were found to be abnormal in identical multivariate analysis with no free parameters. Again, there were not substantial differences on the follow-up scans. Taken together, these results indicate that single-subject, module-based graph theoretic analysis of resting-state fMRI provides potentially useful information for concussive blast-related TBI if high quality scans can be obtained. The underlying biological mechanisms and consequences of disrupted between-module connectivity are unknown, thus further studies are required., (© 2013.)

Previous reports have suggested that the adenosine triphosphate-binding cassette protein ABCG2 (breast cancer resistance protein [BCRP], mitoxantrone resistance [MXR]) is associated with drug resistance in acute myeloid leukemia (AML). The aims of this study were to determine the level of ABCG2 mRNA expression necessary to produce drug resistance and to define the ABCG2 levels in normal bone marrow (BM), peripheral blood (PB), cord blood (CB), and adult AML blast cell populations. First, using transduced clonal cell lines expressing varying levels of ABCG2, we found that ABCG2 expression conferred resistance to mitoxantrone and topotecan, but not to idarubicin. Next, we developed a real-time reverse transcription-polymerase chain reaction assay for measuring ABCG2 mRNA expression levels in clinical samples. Normal BM and PB contained low levels of ABCG2 mRNA, while higher levels were measured in CB mononuclear cells, CD34(+), and Ac133(+) populations, consistent with the known stem cell enrichment in these populations. Next, we studied the ABCG2 mRNA levels in 40 specimens from newly diagnosed adult AML patients. Only 7% of these samples contained ABCG2 mRNA levels within the range of our drug-resistant clone, although another 78% were higher than normal blood and bone marrow. Flow cytometry revealed very small subpopulations of ABCG2-expressing cells in the cases we examined. Our data suggest that high levels of ABCG2 mRNA expression in adult AML blast specimens are relatively uncommon and that ABCG2 expression may be limited to a small cell subpopulation in some cases.

Hematopoietic stem cells (HSCs) can be identified by a "side population" (SP) phenotype. Previous studies have implicated the ATP binding cassette transporter genes Mdr1a/1b and/or Bcrp1 in the SP phenotype. To define the relative role of these transporters, we generated Bcrp1 null mice and evaluated HSCs both functionally and phenotypically. Loss of Bcrp1 gene expression, but not Mdr1a/1b, led to a significant reduction in the number of SP cells in the bone marrow and in skeletal muscle. In the bone marrow, there was a nearly absolute loss of lineage negative, c-Kit-positive, Sca-1-positive SP cells, and the residual SP cells were depleted of repopulating cells in a transplant assay, demonstrating that Bcrp1 expression is necessary for the SP phenotype in HSCs. Furthermore, Bcrp1 null hematopoietic cells were significantly more sensitive to mitoxantrone in drug-treated transplanted mice. These results show that Bcrp1 gene expression alone defines the SP stem cell phenotype, and suggest that the physiological function of Bcrp1 expression in HSCs is to provide protection from cytotoxic substrates.

The macrophage-specific cell surface receptor sialoadhesin, which is a member of the newly recognized family of sialic acid binding lectins called siglecs, binds glycoprotein and glycolipid ligands containing a2-3-linked sialic acid on the surface of several leukocyte subsets. Recently, the sialic acid binding activity of the siglec CD22 has been demonstrated to be regulated by sialylation of the CD22 receptor molecule. In the present work, we show that desialylation of in vivo macrophage sialylconjugates enhances sialoadhesin-mediated lectin activity. Herein, we show that receptor sialylation of soluble sialoadhesin inhibits its binding to Jurkat cell ligands, and that charge-dependent repulsion alone cannot explain this inhibition. Furthermore, we show that the inhibitory effect of sialic acid is partially dependent on the presence of an intact exocyclic side chain. These results, in conjunction with previous findings, suggest that sialylation of siglecs by specific glycosyltransferases may be a common mechanism by which siglec-mediated adhesion is regulated.

The lecithin:cholesterol acyltransferase (LCAT) activity and lysolecithin content of human blood stored under standard blood transfusion service conditions at 4 degrees C for 6 weeks has been investigated. Cooling the blood to 4 degrees C rapidly inactivates the LCAT reaction, but the enzyme is not denatured during storage under these conditions. Citrate in the anticoagulant did not activate the LCAT reaction in freshly-taken whole blood. The total phospholipid and total lysolecithin content of whole blood decreased during storage at 4 degrees C for 6 weeks. The lysolecithin content of fresh red cells (2.0-3.0 mumol lysolecithin x 10(-11) per cell) showed no significant change during the storage period.

The effect of storage in ACD at 4 degrees C on red cell agglutinability and the inhibitory properties of the plasma to blood group reagents has been studied. It was found that the variability demonstrated was related to the origin of the reagent used, particularly between human and on-human sources. The significance of these findings with regard to biochemical and morphological changes in blood on storage is discussed.