Superior axial deviation in the young adult. An electro-vectorcardiographic study

We analyzed the VCGs of 100 young subjects without apparent cardiac disease showing an ECG superior Axis Deviation, i.e. AQRS greater than - 30 degrees, and a rS aspect in V1. Our findings demonstrated that, in these subjects, the superior axis deviation is due to a distal right bundle branch block with posterior displacement of the terminal forces in 78% of the cases. The other cases being left anterior hemiblocks, either isolated (12%) or associated with a block of the anterior subdivision of the right bundle branch (10%). The differential diagnosis, easy on VCG, is sometimes very difficult on ECG. The most reliable ECG criteria to discriminate this kind of right bundle branch block from left anterior hemiblock are: intrinsic deflection in a VL-V6 greater than or equal to 0.015" (sensitivity 100%; specificity 57%), RV6/Ra VL ratio greater than 1 (sensibility 100%; specificity 50%) and the presence of a notched R wave in L2, L3 and a VF (sensitivity 90%; specificity 100%).     

An adult development study of contextual memory

This study tested the hypothesis that there is a relatively greater decrease in memory for contextual features than in memory for target information with increasing age. Young, middle-aged, and elderly adults were presented with a number of slides, each of which contained a word centered on a background composed of either a landscape/cityscape or a border design. One third of the subjects were told to remember the words, one third were told to remember the backgrounds, and one third were told to remember the word-and-background pairs. Recognition memory for both words, backgrounds, and word-and-background pairings was tested in all subjects. The interaction between age, instruction condition, and type of information tested was not significant. Thus, there was no support for the hypothesis that older adults have a greater deficit in contextual memory than in memory for target information when compared to younger adults.     

Cerebral macroaneurysms in a Ghanaian adult population. An autopsy study

An autopsy study of cerebral vessels in 310 Ghanaian adults showed an incidence of macro(berry)aneurysms of 16.6% among 181 hypertensives and 8.5% among 129 normotensives. Hypertension increased the formation and development of intracranial aneurysms. Severe atherosclerosis (Grade 3) was not a common association with aneurysms and there was no increase in aneurysm formation in subjects dying from cerebral haemorrhage. This may be a reflection of the observed low incidence of severe cerebral atherosclerosis in Ghanaians compared to whites and an indication of differences between ethnic groups in the relative importance of the factors that contribute to the formation of aneurysms. Mortality from ruptured aneurysms could not be determined from this study, perhaps because the aneurysms seen were small in size (less than 10 mm diameter) and less likely to rupture and bleed. Multiple aneurysms were an uncommon finding compared to figures quoted in other studies, but in agreement with them the sites of predilection were in the anterior parts of the Circle of Willis; notably the anterior cerebral and anterior communicating arteries.     

Memory for object features versus memory for object location: a positron-emission tomography study of encoding and retrieval processes.

Regional cerebral blood flow was measured with positron-emission tomography during two encoding and two retrieval tasks that were designed to compare memory for object features with memory for object locations. Bilateral increases in regional cerebral blood flow were observed in both anterior and posterior regions of inferior temporal cortex and in ventral regions of prestriate cortex, when the condition that required retrieval of object locations was subtracted from the condition that required retrieval of object features. During encoding, these changes were less pronounced and were restricted to the left inferior temporal cortex and right ventral prestriate cortex. In contrast, both encoding and retrieval of object location were associated with bilateral changes in dorsal prestriate and posterior parietal cortex. Finally, the two encoding conditions activated left frontal lobe regions preferentially, whereas the two retrieval conditions activated right frontal lobe regions. These findings confirm that, in human subjects, memory for object features is mediated by a distributed system that includes ventral prestriate cortex and both anterior and posterior regions of the inferior temporal gyrus. In contrast, memory for the locations of objects appears to be mediated by an anatomically distinct system that includes more dorsal regions of prestriate cortex and posterior regions of the parietal lobe.     

The spatial and developmental relationships in the macrophage family

A classic study in 1968 proposed that bone marrow-dwelling promonocytes differentiate to monocytes, which then intravasate, circulate, and, on tissue entry, differentiate to sessile macrophages. Since then, understanding of the macrophage family relationship has undergone substantial enhancement and occasional revision. It is currently recognized that in addition to their role in the bone marrow, hematopoietic progenitors circulate and give rise to their descendants in extramedullary niches. Monocytes, of which there are several subsets, are not merely circulating macrophage precursors but participate in the immune response in their own right. Macrophages are highly heterogeneous and, as recent studies indicate, can arise in the absence of a monocyte intermediate. These spatial and developmental relationships reveal a complex interactive network and underscore the importance of context in evaluating biological systems. The observations have significant implications for how we image, target, and treat disease.     

Chromosomal location of the gene encoding the neural cell adhesion molecule (N-CAM) in the mouse.

The gene encoding the neural cell adhesion molecule, N-CAM, has been localized on mouse chromosome 9. A BALB/cJ mouse genomic library prepared in lambda bacteriophage EMBL4 was screened by using a cDNA probe, pEC204, that corresponds to the coding region of the chicken N-CAM gene. Four weakly reactive and one strongly reactive recombinant phage were isolated. A region of the latter that was strongly homologous to pEC204 was subcloned to yield a new probe, pEC501. RNA transfer blots and nucleotide sequencing indicated that pEC501 encoded part of the mouse N-CAM gene. This probe defined a unique genetic locus, Ncam, associated with a restriction fragment length polymorphism that allowed the definition of two alleles. The locus could be provisionally assigned either to chromosome 9 or to chromosome 10 by correlating the presence or absence of mouse-specific DNA fragments reactive with the probe in a panel of somatic hybrid cell lines with the presence or absence of the various mouse chromosomes. Analysis of the inheritance of the Ncam-associated DNA polymorphism in recombinant inbred strains of mice revealed close linkage between Ncam and the Lap-1, Sep-1, and Thy-1 loci on chromosome 9. This result suggests an additional linkage between Ncam and the locus for the cerebellar mutation staggerer (sg). The Ncam locus provides an important reference point for mapping the genes for additional cell adhesion molecules as well as genes for other molecules involved in neural development and function.     

Total circulating IgE and FEV1 in adult men. An epidemiologic longitudinal study.

Epidemiologic data relating total circulating immunoglobulin E (IgE), an objective marker of allergy, to cross-sectional and longitudinal FEV1 as well as to methacholine bronchial hyperresponsiveness were obtained from 310 French adult men surveyed five years apart. Skin prick test responses to common aeroallergens, IgE level, and bronchial hyperresponsiveness were assessed at the end of the follow-up. IgE level was not associated with PD20 to methacholine. Cross-sectionally, age and height-adjusted FEV1 score was inversely related to total IgE level (regression coefficient of FEV1 score on Log[IgE] beta = -.20; p = 0.02). Stratified analysis showed that IgE level was associated with FEV1 score only in nonsmokers (beta = -0.52; p less than 0.001), an association that remained after exclusion of asthmatics. Longitudinally, five-year FEV1 decline was related to IgE in nonsmokers (regression coefficient of FEV1 decline on Log[IgE] beta = 19.9; p = 0.03) and exsmokers (beta = 18.9; p = 0.06) but not in current smokers. The relationship persisted, even if with lesser significance, among exsmokers after exclusion of asthmatics (beta = 17.2) and further exclusion of skin prick test-positive men (beta = 18.8). Whether IgE production also reflects factors other than allergy, possibly nonallergic inflammation, needs further investigations.     

Cystic fibrosis. An adult perspective

We treated a patient with an unusual case of cystic fibrosis in whom the diagnosis was not made until age 42 years, the predominant clinical manifestation was recurrent pancreatitis, and the chest roentgenogram and results of pulmonary function tests were normal between bouts of pneumonia. As cystic fibrosis may simulate more benign conditions often seen in adults, the diagnosis must be suspected and confirmed for optimal management. Internists must play an increasingly important role in the diagnosis and management of this disease.     

Conjoint developmental trajectories of young adult substance use

Background. Despite the prominence of comorbidity among substances and the recent attention focused on trajectory‐based approaches to characterizing developmental change, little research in the substance use field has simultaneously considered both course and comorbidity. Methods. Using nationally representative panel data from the Monitoring the Future Project (MTF; n = 32,087; 56% female; 82% Caucasian), we identified developmental courses of heavy drinking, smoking, and marijuana use using 4 waves of data spanning ages 18 to 26 in a multi‐cohort young adult sample. Comorbidity was examined by cross‐classifying group membership in substance use trajectories. Finally, the extent to which risk factors (sex, race, alcohol expectancies, delinquency, sensation seeking, depressive affect, religiosity, academic achievement, and parent education) accounted for combinations of comorbidity that occurred at a rate greater than chance was examined. Results. For each substance, we identified 4 courses of substance use that were largely consistent with those found in the literature (chronic high use, late‐onset use, developmentally limited use, and low‐use), with a fifth moderate smoking group. Heavy drinking, smoking, and marijuana use were each highly associated, and distinct patterns of comorbidity were evident, with greatest agreement along the diagonal. All risk factors explained comorbidity to some degree, with delinquency, sensation seeking, alcohol expectancies, and religion in particular predicting combinations of comorbidity that were characterized by early onset and chronic high use. Conclusions. Cross‐substance trajectory concordance was high, with parallel changes in substance use over emerging adulthood. This suggests similar developmental timing of use, perhaps due to the experience of developmental transitions that have a common influence on use of different substances. Prediction of combinations of comorbidity characterized by early onset and persistently high use suggests that to some extent, individuals use multiple substances because of a common vulnerability to each, rather than directional relations among substances (e.g., cross‐tolerance, cueing).     

Two developmental genes encoding sigma factor homologs are arranged in tandem in Bacillus subtilis.

The sporulation-essential gene spoIIG of the Gram-positive bacterium Bacillus subtilis encodes the sporulation-specific sigma factor sigma 29(sigma E). We report here the initial characterization of a gene, referred to as ORF3, located immediately downstream of the spoIIG gene. The results indicate that ORF3 encodes a sigma homolog, whose expression is highly regulated during development. Analysis of the ORF3 nucleotide sequence reveals an open reading frame encoding a polypeptide of 260 amino acid residues (molecular mass of 30.1 kDa). Its predicted amino acid sequence shows significant similarity to that of other RNA polymerase sigma factor sequences. S1 nuclease mapping experiments indicate that ORF3 is initially cotranscribed with spoIIG from about 1 to 4 hr into the sporulation process and that later on ORF3 is transcribed independently from a new site located between spoIIG and ORF3. The role of ORF3 was investigated by constructing a deletion mutation in its structural gene. The mutant exhibits normal growth but is unable to produce heat-resistant spores. We propose that the ORF3 gene product is a sigma factor or a related peptide essential for sporulation at a late stage of development.     

Thyroid hormone binding to adult rat alveolar type II cells. An autoradiographic study

Hypothyroid adult rats were injected intravenously with [3, 5, 3'-125I]triiodothyronine (T3) or [125I]thyroxine (T4). Others were similarly treated except for the addition of a 500-fold excess of the appropriate unlabeled hormone. Light microscopic autoradiography of semithin sections of lung from these animals demonstrated labeling localized over alveolar parenchymal tissue. Analysis of the labeling studies of type II cells revealed high affinity, low capacity binding of T3 and, to a much lesser extent, T4 to both the nuclear and cytoplasmic compartments. Adult lung in organ culture was also treated with 125I-T3 or 125I-T4 and electron microscopic autoradiography performed. These studies revealed that, when expressed as grains per square micrometer, there was substantially more labeling over the lamellar inclusion bodies and the mitochondria than over the nucleus. The results of this study provide morphologic evidence of specific uptake and binding of thyroid hormones by the nucleus and cytoplasm of alveolar type II cells, and suggest that the lamellar inclusion bodies and mitochondria may be the primary location of the cytoplasmic binding. These findings also substantiate the view of a direct effect of thyroid hormones on the lung and, in particular, on the type II alveolar cells.     

Distinct neural correlates of visual long-term memory for spatial location and object identity: a positron emission tomography study in humans.

The purpose of the present study was to investigate by using positron emission tomography (PET) whether the cortical pathways that are involved in visual perception of spatial location and object identity are also differentially implicated in retrieval of these types of information from episodic long-term memory. Subjects studied a set of displays consisting of three unique representational line drawings arranged in different spatial configurations. Later, while undergoing PET scanning, subjects' memory for spatial location and identity of the objects in the displays was tested and compared to a perceptual baseline task involving the same displays. In comparison to the baseline task, each of the memory tasks activated both the dorsal and the ventral pathways in the right hemisphere but not to an equal extent. There was also activation of the right prefrontal cortex. When PET scans of the memory tasks were compared to each other, areas of activation were very circumscribed and restricted to the right hemisphere: For retrieval of object identity, the area was in the inferior temporal cortex in the region of the fusiform gyrus (area 37), whereas for retrieval of spatial location, it was in the inferior parietal lobule in the region of the supramarginal gyrus (area 40). Thus, our study shows that distinct neural pathways are activated during retrieval of information about spatial location and object identity from long-term memory.     

Deformation of the adult rheumatoid rearfoot. A radiographic study

Summary Three hundred ninety-seven adult rheumatoid feet were examined. Those in whom pain had been present since the onset of the disease were compared radiographically with the painless feet in standing position: examination of the talar angle and of the internal arch showed flattening on the affected feet. The calcaneal angle, on the other hand, showed no difference between the two groups, but this latter parameter is little affected by the valgus pronation deformity of the hindfoot most often seen in patients who had experienced foot pain.     

Stroop interference in children with developmental dyslexia: An event-related potentials study

Previous studies have identified inhibitory deficits in dyslexic children, but we have little understanding of their neural mechanisms, especially for Chinese children with developmental dyslexia.We used a double-blind controlled trial to study the electroencephalogram responses of dyslexic and non-dyslexic children when performing the Stroop color-word test.Behavioral data showed differences in response time and accuracy between the 2 groups. In the event-related potentials (ERP) results, dyslexic children displayed larger P2 and P3b on congruent trials, while non-dyslexic children displayed larger P2 and P3b on incongruent trials, the 2 groups showed opposite brain activation patterns on the Stroop test.Dyslexic children have poor inhibitory function, and this poor inhibition may be related to their abnormal brain activation patterns.     

日本血吸虫(中国大陆株)线粒体相关蛋白rSj338的免疫细胞化学定位

目的　应用免疫电镜技术观察日本血吸虫线粒体相关蛋白rSj338在成虫组织细胞中的分布和定位。 方法　收集新鲜的日本血吸虫成虫 ,常规固定、包埋 ,制备日本血吸虫成虫超薄冷冻切片。用纯化的抗rSj338单特异多克隆抗体为一抗 ,同时 ,以正常兔血清作阴性对照 ;以直径为 10nm胶体金颗粒标记的蛋白A进行定位 ,进行组织化学反应 ,透射电镜观察日本血吸虫线粒体相关蛋白rSj338在成虫组织细胞中的分布和定位。 结果　高密度胶体金颗粒主要分布于日本血吸虫线粒体外膜上 ,在线粒体的嵴上也见分布。结论　rSj338蛋白确为日本血吸虫线粒体相关蛋白 ,与采用BLAST网分析结果同源性一致