Multi-dimensional clinical phenotyping of a national cohort of adult cystic fibrosis patients

BackgroundCystic Fibrosis (CF) is a multi-systemic disorder resulting from genetic variation in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene which can result in bronchiectasis, chronic sinusitis, pancreatic malabsorption, cholestatic liver disease and distal intestinal obstructive syndrome. This study generates multi-dimensional clinical phenotypes that capture the complexity and spectrum of the disease manifestations seen in adult CF patients using statistically robust techniques.MethodsPre-transplant clinical data from adult (age ≥18 years) CF patients (n = 992) seen in six regionally distinct US CF centers between 1/1/2014 and 6/30/2015 were included. Demographic, spirometry, nutritional, microbiological and therapy data were used to generate clusters using the Random Forests statistical-learning and Partitioning around Medoids (PAM) clustering algorithms. Five commonly measured demographic, physiological and nutritional parameters were needed to create the final phenotypes that are highly similar to a regionally matched group of patients from the CF Foundation Patient RegistryResultsThis approach identified high-risk phenotypes with expected characteristics including high rates of pancreatic insufficiency, diabetes and Pseudomonas aeruginosa colonization. It also identified unexpected populations including a) a male-dominated, well-nourished group with good lung function with a high prevalence of severe genotypes (i.e. 60% subjects had two minimal function CFTR variations), b) and an older, “survivor” phenotype that had high rates of chronic P. aeruginosa infection.ConclusionsThis study identified recognizable phenotypes that capture the clinical complexity in a statistically robust manner and which may aide in the identification of specific genetic and environmental factors responsible for these disease manifestation patterns.     

Distinct immunopathological mechanisms of EBV-positive and EBV-negative posttransplant lymphoproliferative disorders

EBV-positive and EBV-negative posttransplant lymphoproliferative disorders (PTLDs) arise in different immunovirological contexts and might have distinct pathophysiologies. To examine this hypothesis, we conducted a multicentric prospective study with 56 EBV-positive and 39 EBV-negative PTLD patients of the K-VIROGREF cohort, recruited at PTLD diagnosis and before treatment (2013–2019), and compared them to PTLD-free Transplant Controls (TC, n = 21). We measured absolute lymphocyte counts (n = 108), analyzed NK- and T cell phenotypes (n = 49 and 94), and performed EBV-specific functional assays (n = 16 and 42) by multiparameter flow cytometry and ELISpot-IFNγ assays (n = 50). EBV-negative PTLD patients, NK cells overexpressed Tim-3; the 2-year progression-free survival (PFS) was poorer in patients with a CD4 lymphopenia (CD4⁺<300 cells/mm³, p <  .001). EBV-positive PTLD patients presented a profound NK-cell lymphopenia (median = 60 cells/mm³) and a high proportion of NK cells expressing PD-1 (vs. TC, p = .029) and apoptosis markers (vs. TC, p < .001). EBV-specific T cells of EBV-positive PTLD patients circulated in low proportions, showed immune exhaustion (p = .013 vs. TC) and poorly recognized the N-terminal portion of EBNA-3A viral protein. Altogether, this broad comparison of EBV-positive and EBV-negative PTLDs highlight distinct patterns of immunopathological mechanisms between these two diseases and provide new clues for immunotherapeutic strategies and PTLD prognosis.     

Experimental Induction of Emotional and Sexual Intimacy: Exploring the Validity of the German Fast Friends Procedure in Individuals with and without Childhood Maltreatment

The Fast Friends Procedure (FFP) is a widely used experimental paradigm to induce emotional intimacy. Besides exploring the validity of a German translation of the paradigm (n?=?46), we developed an extension of the FFP that induces sexual intimacy and assessed heart rate, high-frequency heart rate variability, and electrodermal activity responses to the FFP and its extension. Furthermore, we examined its applicability to individuals with childhood maltreatment (n?=?56), who frequently suffer from intimacy-related difficulties. Intimacy, positive affect, liking, and attraction increased during the FFP and partly during the sexual intimacy extension in both study groups. Moreover, both groups showed physiological responses consistent with positive social interactions. The use of the German FFP and its sexual intimacy extension can thus be recommended for research in the general population and in individuals with childhood maltreatment, although more studies are needed to further validate the paradigms.

     

The Validity of Women's Reports of Family Planning Service Quality in Cambodia and Kenya

Population‐based indicators of the coverage of key elements of high‐quality family planning services are tracked via household surveys with female respondents, yet little work has been done to establish their validity. We take advantage of existing data sets from Cambodia and Kenya to compare women's responses at exit interviews following a health facility visit against the observations of a trained third‐party observer during the visit. The results, which treat the observations as the reference standard, show that indicators that measure contraceptive methods received are accurately reported while indicators of whether the woman received her preferred method and whether information was “discussed” or “explained” during counseling are less reliably reported. Studies designed explicitly to assess the validity of family planning questions in household surveys, especially questions in large survey programs critical for monitoring demographic trends and programmatic coverage, are needed.     

The treatment of obesity by carbohydrate deprivation suppresses plasma tryptophan and its ratio to other large neutral amino acids

We measured plasma concentrations of tryptophan (Trp) and the other large neutral amino acids (LNAA) in 6 control and 7 obese subjects before and after they consumed a low-carbohydrate "protein-sparing modified fast" (PSMF) diet; LNAA levels in control subjects were also assessed after supplemental oral Trp. Consumption of the PSMF diet by non-obese subjects, or obesity per se, caused major reductions in the ratio of the plasma Trp concentration to the summed plasma concentrations of the other LNAA (i.e., the "plasma Trp ratio"), and may thus have diminished brain serotonin synthesis. Administration of even 2 g of supplemental Trp did not elevate the plasma Trp ratio beyond the normal range observed previously in subjects consuming carbohydrate-containing meals.     

A phase I trial of ZD9331, a water-soluble, nonpolyglutamatable, thymidylate synthase inhibitor.

PURPOSE: ZD9331 is a novel, direct-acting antifolate cytotoxic that does not require polyglutamation for activity, and is a specific thymidylate synthase inhibitor. This Phase I trial aimed to determine the maximum tolerated dose of ZD9331, given as a 30-min i.v. infusion on days 1 and 8 of a 21-day cycle. Pharmacokinetic parameters and tumor response were also assessed. EXPERIMENTAL DESIGN: A total of 71 patients, with a range of solid malignancies and refractory to standard therapies (44% had received > or =3 prior chemotherapy regimens), were treated. The most common malignancies were colorectal cancer (35% of patients) and ovarian cancer (31%). ZD9331 was escalated from 4.8 mg/m(2)/day. RESULTS: Dose-limiting toxicity occurred at 162.5 mg/m(2) ZD9331, with grade 4 thrombocytopenia, grade 4 neutropenia lasting > or =7 days, and grade 3 nonhematologic toxicity. Plasma clearance of ZD9331 was slow and dose-dependent; however, ZD9331 pharmacokinetics were nonlinear. Pharmacodynamics of ZD9331 were determined by measurement of plasma deoxyuridine, which increased at all of the dose levels; dose-related increases in plasma deoxyuridine were significant (P = 0.003) on day 5. Stable disease was observed in 37% of patients; 23% of ovarian cancer patients had a > or =50% reduction in CA125 levels. CONCLUSIONS: The maximum tolerated dose of this schedule was 130 mg/m(2). The toxicity profile at this dose was acceptable, with 7 of 28 patients treated developing grade 3/4 neutropenia and thrombocytopenia, 2 grade 4 diarrhea, and 2 grade 3/4 rash. This schedule was convenient and demonstrated activity in extensively pretreated patients; therefore, this is the recommended dose for study in Phase II trials.     

Membrane depolarization is the initial action of crotoxin on isolated murine skeletal muscle.

Although much is known about the pathogenesis of crotoxin-induced muscle damage, the initial site and action of the toxin is still not clear. In this study we used an electrochromic fluorescent dye, Di-4-ANEPPS, to measure the changes in membrane potential of isolated murine omohyoid muscle to determine if depolarization could be one of the initial effects of crotoxin. Omohyoid isolates were pre-loaded with 1 microM Di-4-ANEPPS, exposed to various crotoxin treatments, and the change in fluorescence was recorded using either a dual-wavelength spectrofluorometer or digital imaging. Spectrofluorometry indicated that crotoxin depolarized isolated omohyoid muscles within 4 min as indicated by an increase in fluorescence to 122% of control values. Crotoxin also induced depolarization of extensor digitorum longus and soleus muscles as indicated by an increase in fluorescence of 140 and 110% of the control, respectively. Fluorescent images obtained from omohyoid muscle preparations exposed to crotoxin and Di-4-ANEPPS revealed localized areas of increased fluorescence, muscle contractions, derangement of myofibrils, and differing sensitivity to crotoxin of different muscle cells. Light microscopy results confirmed this variable disruption of muscle cell integrity and differing sensitivity to crotoxin. An increase in creatine kinase release rates confirmed damage to the plasma membrane. We conclude that plasma membrane depolarization is most likely the earliest indicator of cell damage from crotoxin and is quickly followed by hypercontraction of myofilaments, disruption of the plasma membrane, release of creatine kinase and necrosis.