Respiratory phenotypes of neuromuscular diseases: A challenging issue for pediatricians

Neuromuscular disease (NMDs) encompass a heterogeneous group of genetic disorders, with respiratory problems of variable intensity and progression described at any pediatric age, from infancy to adolescence, and they are largely associated with significant lifelong morbidity and high mortality. Restriction of breathing, impaired gas exchange, decline of lung function and sleep disordered breathing progressively develop because of muscular weakness and culminate in respiratory failure. Depending on the disease progression, airways manifestations can take weeks to months or even years to evolve, thus depicting two major respiratory phenotypes, characterized by rapid or slow progression to respiratory failure. Assessing type and age at onset of airways problems and their evolution over time can support pediatricians in the diagnostic assessment of NMD. In addition, knowing the characteristics of patients' respiratory phenotype can increase the level of awareness among neonatologists, geneticists, neurologists, pulmonologists, nutritionists, and chest therapists, supporting them in the challenging task of the multidisciplinary medical care of patients. In this review we examine the issues related to the pediatric respiratory phenotypes of NMD and present a novel algorithm that can act as a guide for the diagnostic agenda and the key preventive or therapeutic interventions of airways manifestations. With prolonged survival of children with NMD, the advent of neuromuscular respiratory medicine, including accurate assessment of the respiratory phenotype, will help physicians to determine patients’ prognoses and to design studies for the evaluation of new therapies.     

Genotype‐phenotype associations in breast pathology: Achievements of the past quarter century

The first genotype‐phenotype relationship in breast pathology developed in 1994 with the discovery of the CDH1 gene. This finding eventually provided biological insight into the characteristic morphology of invasive lobular carcinoma. Subsequent investigative efforts have uncovered additional molecular alterations largely responsible for the histology of several breast neoplasms including secretory carcinoma, adenoid cystic carcinoma, tall cell carcinoma with reversed polarity, fibroepithelial lesions, and most recently, adenomyoepithelioma. Evaluation of the genomic landscape of other special types of breast cancer with distinctive growth patterns, such as invasive mucinous carcinoma, have yet to uncover recurring cytogenetic and/or molecular alterations. Despite the lack of a hallmark alteration in mucinous carcinoma, it is important to note the relative decrease in PIK3CA mutations compared with invasive carcinoma of no special type. In this review, we describe the clinical and pathologic features of breast tumors with recognized genotype‐phenotype correlations and summarize the molecular alterations of mucinous carcinoma.     

γ-线照射对人树突状细胞表型及功能的影响

为了了解γ-线照射是否影响体外培养的树突状细胞的表型与功能，利用含rhGM-CSF(800U/ml)和rhIL-4(500U/ml）的RPMI1640培养基从多发性硬化症病人的外周血单个核细胞（PBMNC）中诱生树突状细胞（DC）。在培养的第6天加入5μg/ml的脂多糖继续培养24小时促使DC完全成熟。于第7天收获DC并等分成几部分，一部分未经γ-线照射的DC用作对照组，其他部分的DC分别用25Gy和30Gy剂量的γ射线照射。流式细胞术分析DC的表面分子并测定DC细胞刺激同源T细胞增殖的能力。结果表明，γ-线照射减少树突状细胞CD86，CD80和HLA-DR表达，尤其是CD86分子的表达（P=0.0072）。人DC能有效地刺激同源T细胞的增殖，但是同未经照射的DC相比，照射的DC刺激T细胞增殖的能力显降低。结论：γ-线照射不仅影响DC的表型，而且影响它的功能。     

视网膜色素变性发病机制及治疗进展

视网膜色素变性（retintis pigmentosa,RP）是指以进行性感光细胞及色素上皮功能丧失为共同表现的遗传性、退行性的疾病,RP是主要的致盲性眼病。其遗传方式包括X连锁遗传、常染色体隐性或者显性遗传,也有散发。临床表现为典型的三联征:骨细胞样色素沉着、视网膜血管缩窄和视盘蜡样苍白。RP具有高度的基因异质性(多个突变位点引起同一疾病）及表型异质性。本文对RP的发病机制和治疗方法进行简要综述。     

An MHV-68 Mutator Phenotype Mutant Virus,Confirmed by CRISPR/Cas9-Mediated Gene Editing of the Viral DNA Polymerase Gene,Shows Reduced Viral Fitness

Drug resistance studies on human γ-herpesviruses are hampered by the absence of an in vitro system that allows efficient lytic viral replication. Therefore, we employed murine γ-herpesvirus-68 (MHV-68) that efficiently replicates in vitro as a model to study the antiviral resistance of γ-herpesviruses. In this study, we investigated the mechanism of resistance to nucleoside (ganciclovir (GCV)), nucleotide (cidofovir (CDV), HPMP-5azaC, HPMPO-DAPy) and pyrophosphate (foscarnet (PFA)) analogues and the impact of these drug resistance mutations on viral fitness. Viral fitness was determined by dual infection competition assays, where MHV-68 drug-resistant viral clones competed with the wild-type virus in the absence and presence of antivirals. Using next-generation sequencing, the composition of the viral populations was determined at the time of infection and after 5 days of growth. Antiviral drug resistance selection resulted in clones harboring mutations in the viral DNA polymerase (DP), denoted Y383S^GCV, Q827R^HPMP-5azaC, G302W^PFA, K442T^PFA, G302W+K442T^PFA, C297W^HPMPO-DAPy and C981Y^CDV. Without antiviral pressure, viral clones Q827R^HPMP-5azaC, G302W^PFA, K442T^PFA and G302W+K442T^PFA grew equal to the wild-type virus. However, in the presence of antivirals, these mutants had a growth advantage over the wild-type virus that was moderately to very strongly correlated with antiviral resistance. The Y383S^GCV mutant was more fit than the wild-type virus with and without antivirals, except in the presence of brivudin. The C297W and C981Y changes were associated with a mutator phenotype and had a severely impaired viral fitness in the absence and presence of antivirals. The mutator phenotype caused by C297W in MHV-68 DP was validated by using a CRISPR/Cas9 genome editing approach.     

Reduction in Virulence over Time in Ostreid herpesvirus 1 (OsHV-1) Microvariants between 2011 and 2015 in Australia

Microvariant genotypes of Ostreid herpesvirus 1 (OsHV-1) are associated with mass mortality events of Pacific oysters in many countries. The OsHV-1 microvariant (µVar) emerged in France 2008 and caused significant economic losses as it became endemic and displaced the previously dominant OsHV-1 reference genotype. Recently, considerable genotypic variation has been described for OsHV-1 microvariants, however, less is known about variation in viral phenotype. This study used an in vivo laboratory infection model to assess differences in total cumulative mortality, peak viral load, transmissibility, and dose-response for three OsHV-1 isolates obtained between 2011 and 2015 from endemic waterways in Australia. This followed field observations of apparent reductions in the severity of mass mortalities over this time. Significantly higher hazard of death and cumulative mortality were observed for an isolate obtained in 2011 compared to isolates from 2014–2015. In keeping with other studies, the hazard of death was higher in oysters challenged by injection compared to challenge by cohabitation and the mortality was higher when the initial dose was 1 × 10⁴ OsHV-1 DNA copies per oyster injection compared to 1 × 10² DNA copies. There was no difference in the quantity of OsHV-1 DNA at time of death that could be related to isolate or dose, suggesting similar pathogenetic processes in the individual oysters that succumbed to end-stage disease. While the isolates examined in this study were biased towards pathogenic types of OsHV-1, as they were collected during disease outbreaks, the variation in virulence that was observed, when combined with prior data on subclinical infections, suggests that surveillance for low virulence genotypes of OsHV-1 would be rewarding. This may lead to new approaches to disease management which utilize controlled exposure to attenuated strains of OsHV-1.     

Computed tomography-based visual assessment of chronic obstructive pulmonary disease: comparison with pulmonary function test and quantitative computed tomography

BackgroundChronic obstructive pulmonary disease (COPD) has variable subtypes involving mixture of large airway inflammation, small airway disease, and emphysema. This study evaluated the relationship between visually assessed computed tomography (CT) subtypes and clinical/imaging characteristics.MethodsIn total, 452 participants were enrolled in this study between 2012 and 2017. Seven subtypes were defined by visual evaluation of CT images using Fleischner Society classification: normal, paraseptal emphysema (PSE), bronchial disease, and centrilobular emphysema (trace, mild, moderate and confluent/advanced destructive). The differences in several variables, including clinical, laboratory, spirometric, and quantitative CT features among CT-based visual subtypes, were compared using the chi-square tests and one-way analysis of variance.ResultsSubjects who had PSE had better forced expiratory volume in 1 second (FEV1) (P=0.03) percentage and higher lung density (P<0.05) than those with moderate to confluent/advanced destructive centrilobular emphysema. As the visual grade of centrilobular emphysema worsened, pulmonary function declined and modified Medical Research Council, COPD assessment test (CAT) score, and quantitative assessment (emphysema index and air trapping) increased. The bronchial subtype was associated with higher body mass index (BMI), better lung function and higher lung density. Participants with trace emphysema showed a rapid increase in functional small airway diseaseConclusionsClassifying subtypes using visual CT imaging features can reflect heterogeneity and pathological processes of COPD.     

The association between the hypertriglyceridaemia waist phenotype,cardiovascular risk factors and the metabolic syndrome in South African Asian-Indians

Background and aimsThe combination of high triglycerides and increased waist circumference (HTGW) has not been examined as a predictor of cardiometabolic abnormalities or the metabolic syndrome (MetS) in high-risk Asian populations. This study examines the so-called hypertriglyceridemia waist (HTGW) phenotype, (high serum triglycerides [Tg]) and increased waist circumference (WC) as a predictor of cardiometabolic abnormalities in a high-risk Asian population.MethodsData from the Phoenix Lifestyle Project, a cross-sectional study of 1349 South Asian Indians (15–65 years; 379 men; 970 women) in Durban, KwaZulu-Natal, were reclassified into different waist and Tg phenotypes using the demographic, anthropometric, and biochemical parameters. The HTGW phenotype was defined as WC ≥ 90 cm for men; ≥80 cm for women & TG ≥ 1.7 mmol/L. The MetS was determined using the harmonised criteria. Stepwise logistic regression was used to determine the strength of each phenotype as a predictor of the MetS.ResultsThe HTGW phenotype was recorded in 35.4% of participants, predominantly women (36.1%) and 8.2% smokers. Metabolic derangements and cardiovascular risk factors increased significantly in those with HTGW phenotype. After adjustment, multivariate logistic regression showed that the association between elevated total serum cholesterol, LDL, lowered HDL, diabetes and hypertension with HTGW persisted. The odds for participants with the HTGW phenotype developing the MetS was 19.7 (95% CI 13.9; 27.9). The degree of concordance between the HTGW was highest with the IDF and harmonised criteria for MetS.ConclusionThe HTGW phenotype was associated with a significantly higher risk of developing additional lipid derangements, hypertension, diabetes and the MetS.     

Different organization of von Willebrand factor oligomers in type-2A and -2B von Willebrand disease variants: effects of DDAVP infusion and protease inhibitors

The existence of leukemic-associated phenotypes has been suggested to be a valuable tool for the detection of minimal residual disease (MRD) in AML patients, as they would allow to distinguish leukemic blast cells from normal hematopoietic progenitors. The present study was designed to analyze in which proportion of AML patients the immunological detection of MRD is feasible, based on the presence of aberrant phenotypes that allow the distinction of leukemic from normal cells. For this purpose we have prospectively investigated the blast cells from 40 AML patients at diagnosis with a large panel of MoAb in double and triple staining combinations analyzed at flow cytometry, in order to detect aberrant phenotypes on blast cells (lineage infidelity, antigenic overexpression, and asynchronous antigenic expression, as well as aberrant lightscatter pattern). In the analysis of the 40 AML cases more than one blast cell subset, distinguished by its different antigenic expression, was detected in 85% of the patients: five different phenotypic blast cell subsets were observed in six cases, four in 13 patients, three subsets in three cases, and two in 12 patients; only six cases showed a homogeneous phenotypical blast cell population. Twenty-nine of the 40 AML cases analyzed (73%) showed the existence of at least one aberrant phenotype: in 15 cases the myeloid blast cells co-expressed lymphoid-associated antigens (CD2, CD5, CD7, and/or CD19) - lineage infidelity -; asynchronous antigen expression was detected in 25 patients (CD34+CD56+, CD34+CD11b+, CD34+CD14+, CD117+CD15+, CD33-CD13+, CD13-CD15+, HLADR+CD15+++, HLADR-CD14+CD11b+ CD4+); seven cases displayed antigen overexpression (CD13, CD33, CD15, or CD14); and in 13 patients leukemic cells had an abnormal FSC/SSC distribution according to their phenotype. These results suggest that immunological methods for the detection of MRD based on the existence of aberrant phenotypes could be used in the majority of AML patients.