Longitudinal Trajectories of Gestational Thyroid Function: A New Approach to Better Understand Changes in Thyroid Function

Context Most studies of thyroid function changes during pregnancy use a cross-sectional design comparing means between groups rather than similarities within groups. Objective Latent class growth analysis (LCGA) is a novel approach to investigate longitudinal changes that provide dynamic understanding of the relationship between thyroid status and advancing pregnancy. Design Prospective observational study with repeated assessments. Setting General community. Patients Eleven hundred healthy women were included at 12 weeks’ gestation. Main Outcome Measures The existence of both free T4 (fT4) and TSH trajectories throughout pregnancy determined by LCGA. Results LCGA revealed three trajectory classes. Class 1 (n = 1019; 92.4%), a low increasing TSH reference group, had a gradual increase in TSH throughout gestation (from 1.1 to 1.3 IU/L). Class 2 (n = 30; 2.8%), a high increasing TSH group, displayed the largest increase in TSH (from 1.9 to 3.3 IU/L). Class 3 (n = 51; 4.6%), a decreasing TSH group, had the largest fall in TSH (from 3.2 to 2.4 IU/L). Subclinical hypothyroidism at 12 weeks occurred in up to 60% of class 3 women and was accompanied by elevated thyroid peroxidase antibodies (TPO-Ab) titers (50%) and a parental history of thyroid dysfunction (23%). In class 2, 70% of women were nulliparous compared with 46% in class 1 and 49% in class 3. Conclusions LCGA revealed distinct trajectories of longitudinal changes in fT4 and TSH levels during pregnancy in 7.4% of women. These trajectories were correlated with parity and TPO-Ab status and followed patterns that might reflect differences in pregnancy-specific immune tolerance between nulliparous and multiparous women

Sublobar Pulmonary Resection in Children With Congenital Lung Abnormalities:A Systematic Review

Background:Lobectomy is currently the advised resection for symptomatic congenital lung abnormalities (CLA). Sublobar surgery is suggested as an alternative that enables to conserve healthy lung parenchyma. This systematic review aims to explore the outcomes of sublobar surgery in CLA patients as well as the corresponding surgical terminology and techniques. Methods: A systematic literature search was performed in adherence to PRISMA-P guidelines. The target population consists of children undergoing sublobar pulmonary resection for CLA. All studies were independently assessed by two reviewers, and evaluated by a third reviewer in case of disagreement. Results: The literature search yielded 901 studies of which 18 studies were included, comprising 1167 cases. The median chest tube insertion duration was 3.6 days (range 2.0–6.9 days), the median hospital admission was 4.9 days (range 2.0–14.5 days), and residual disease was diagnosed in 2% – leading to re-operation in 70%. The median incidence of postoperative complications was 15% (range 0–67%). Follow-up imaging was standard-of-care in 2/3 of studies. Due to the absence of standardised terminology, operative details and specification of resection type did not typically relate between studies. Conclusions: Sublobar resection of CLA lesions could be a viable alternative to lobectomy in certain cases, with the advantage of conserving healthy lung parenchyma. Peri- and postoperative complications are comparable with those reported for conventional lobectomy. The incidence of residual disease following sublobar surgery appears to be lower than commonly stated. To improve comparability between studies, we recommend reporting perioperative characteristics in a structured format. Level of evidence: Level IV.</p

Genomic deletions of MSH2 and MLH1 in colorectal cancer families detected by a novel mutation detection approach

Hereditary non-polyposis colorectal cancer is an autosomal dominant condition due to germline mutations in DNA-mismatch-repair genes, in particular MLH1, MSH2 and MSH6. Here we describe the application of a novel technique for the detection of genomic deletions in MLH1 and MSH2. This method, called multiplex ligation-dependent probe amplification, is a quantitative multiplex PCR approach to determine the relative copy number of each MLH1 and MSH2 exon. Mutation screening of genes was performed in 126 colorectal cancer families selected on the basis of clinical criteria and in addition, for a subset of families, the presence of microsatellite instability (MSI-high) in tumours. Thirty-eight germline mutations were detected in 37 (29.4%) of these kindreds, 31 of which have a predicted pathogenic effect. Among families with MSI-high tumours 65.7% harboured germline gene defects. Genomic deletions accounted for 54.8% of the pathogenic mutations. A complete deletion of the MLH1 gene was detected in two families. The multiplex ligation-dependent probe amplification approach is a rapid method for the detection of genomic deletions in MLH1 and MSH2. In addition, it reveals alterations that might escape detection using conventional diagnostic techniques. Multiplex ligation-dependent probe amplification might be considered as an early step in the molecular diagnosis of hereditary non-polyposis colorectal cancer

Postnatal chest X-ray in children with asymptomatic congenital lung malformations

ObjectiveThe clinical implications of a postnatal chest X-ray (CXR) in asymptomatic children with a prenatally diagnosed congenital lung malformation (CLM) are uncertain. We assessed the justification for the postnatal use of CXR in these children.MethodsWe included patients with CLM confirmed through chest computed tomography angiography or histopathological analysis who were asymptomatic at birth, underwent routine postnatal CXR, and participated in our standard of care prospective structured longitudinal follow-up program. Children with major associated morbidities were excluded. Primary outcomes were the positive and negative predictive values (PPV and NPV) of CXR findings for symptom development at 4 weeks and 6 months of age. Secondarily, we sought to establish whether CXR findings were associated with undergoing additional diagnostics during the initial observational hospital stay or prolonged postnatal hospital admission.ResultsAmong 121 included patients, CXR showed no abnormalities in 35 (29%), nonspecific abnormalities in 23 (19%), and probable CLM in 63 (52%). The PPV of CXR in relation to symptom development at 4 weeks and 6 months was 0.05 and 0.25, respectively. Corresponding NPVs were 0.96 and 0.91. An association was identified between CXR findings and undergoing further diagnostics during the initial observational hospital stay (p = .047). Additional diagnostic findings did not influence clinical management. CXR findings were not associated with prolonged initial hospital stay (p = .40).ConclusionThe routine practice of postnatal CXR in asymptomatic patients with prenatally diagnosed CLM can be omitted, as CXR findings do not influence subsequent clinical management

Possible relevance of pigeons as an indicator species for monitoring air pollution.

Wild city pigeons were caught at four different locations in the Netherlands to represent areas of high (Amsterdam-high), moderate (Amsterdam-medium), and low (Maastricht and Assen) traffic density. It is assumed that local ambient air pollution decreases as a function of traffic density. In these pigeons levels of polycyclic aromatic hydrocarbon (PAH)-DNA adducts, oxidative DNA damage, and heavy metal residues were determined in kidney, lung, liver, and blood (no adduct analysis in blood). The contribution of leaded gasoline to total body lead content was estimated by measuring concentrations of Pb and its isotopes in blood. We also analyzed samples of ambient air particulate matter for PAH and heavy metal concentrations at the four different locations. Interregional differences in heavy metals in ambient air particulate matter were reflected relatively well by pigeon body loads. The higher lead and cadmium concentrations in blood, kidney, liver, and lung were found in the Amsterdam high traffic density area, followed by Amsterdam medium, Assen, and Maastricht. A high Pb concentration in blood coincided with relatively low 206Pb/207Pb values, indicating a high contribution of leaded gasoline to total blood Pb concentrations in pigeons from the Amsterdam high traffic density area. Significantly enhanced blood zinc values were found in pigeons from both locations in Amsterdam compared to pigeons from the other two areas. However, no differences in Zn tissue levels between the four different groups were found. Oxidative DNA damage, determined as the ratio of 7-Hydro-8-oxo-2'-deoxyguanosine/ deoxyguanosine, in pigeon liver was highest in Amsterdam-high, followed by Assen (low traffic density). Pb content, but not the Cd content, was positively associated with oxidative DNA damage in liver tissue. In lung tissue, a negative correlation was found between oxidative DNA damage and Zn content. These results indicate that the carcinogenic potential of Pb might be ascribed to oxygen radical formation, whereas Zn plays a protective role against oxidative DNA damage. Places with high and medium traffic density could be clearly discriminated on the basis of PAH levels in the ambient air. The PAH content in particulate air samples was not, however, reflected in total PAH-related DNA adduct levels because no differences could be observed in tissue adduct levels in pigeons from the four different locations. Our results indicate that wild city pigeons can be used as biological indicators of exposure to heavy metal pollution in outdoor air

Longitudinal evaluation, acceptability and long-term retention of knowledge on a horizontally integrated organic and functional systems course

Undergraduate medical education is moving from traditional disciplinary basic science courses into more integrated curricula. Integration models based on organ systems originated in the 1950s, but few longitudinal studies have evaluated their effectiveness. This article outlines the development and implementation of the Organic and Functional Systems (OFS) courses at the University of Minho in Portugal, using evidence collected over 10 years. It describes the organization of content, student academic performance and acceptability of the courses, the evaluation of preparedness for future courses and the retention of knowledge on basic sciences. Students consistently rated the OFS courses highly. Physician tutors in subsequent clinical attachments considered that students were appropriately prepared. Performance in the International Foundations of Medicine examination of a self-selected sample of students revealed similar performances in basic science items after the last OFS course and 4 years later, at the moment of graduation. In conclusion, the organizational and pedagogical approaches of the OFS courses achieve high acceptability by students and result in positive outcomes in terms of preparedness for subsequent training and long-term retention of basic science knowledge

О параллельной обработке потока данных, адаптированной к области бит произвольной конфигурации

Предлагается модель операции свёртки арифметических многорядных двоичных кодов (МРК), которая учитывает неравномерность распределения бит данных по разрядам. На основе этой модели разрабатываются процедуры и методы свёртки МРК, которые позволяют снизить задержку на обработку.Пропонується модель операції згортки арифметичних багаторядних двійкових кодів (БРК), яка зважає на нерівномірність розподілу біт даних за разрядами. На основі цієї моделі розроблюються процедури і методи згортки БРК, які дозволяють зменшити затримку на обробку.Model of the compressing operation of arithmetic multi-row binary codes (MRC) is offered. In this model irregularity allocation of data bit per digits is considered. Procedures and methods of compressing MRC based on this model allow diminish delay of processing are designed (developed)