Image-directed percutaneous biopsies with a biopsy gun

Core tissue for histologic study is believed by many pathologists to be more diagnostic than material from needle aspiration. Recently, a biopsy "gun" has been introduced, which simplifies core biopsies. With this device, 182 biopsies of multiple anatomic sites were performed with ultrasonic, computed tomographic, and fluoroscopic guidance and 18-gauge needles. High-quality histopathologic specimens were obtained in 177 of the biopsies, and diagnostic target tissue was obtained in 167. Only three significant complications occurred: one bleeding complication that required transfusion and two cases of pneumothorax that necessitated placement of chest tubes. The biopsy gun eliminated the disjointed movements of conventional "skinny" needle biopsies, and none of the samples demonstrated significant "crush" artifact or obscuring blood, problems that are commonly associated with manual biopsy techniques. Patient discomfort was decreased with this system compared with that of manual biopsies, and the total procedure time was reduced. Because of these distinct advantages, the authors now use the biopsy gun exclusively for all percutaneous biopsies and recommend that other institutions consider the use of this biopsy method.     

新生期大白鼠皮下注射谷氨酸单钠对成年后下丘脑α-促黑素细胞激素神经元免疫反应性的影响

本文用免疫组化方法研究了新生期大白鼠注射谷氨酸单钠(MSG)对成年后下丘脑α-促黑素细胞激素(α-MSH)免疫反应神经元的影响,结果显示MSG处理以后下丘脑弓状核区α-MSII免疫反应神经元减少甚至完全消失,但不影响下丘脑背外侧区的α-MSH神经元群。文中还讨论了这两群α-MSH神经元的生理作用。     

Three-dimensional modeling of the anatomy of the heart and great vessels

Summary The anatomic constraints imposed on a total artificial heart (TAH) require specific anatomic studies. A thoracic anatomic study was performed with a scanning device equipped with three-dimensional (3-D) reconstruction software on 15 male patients, between the ages of 41 to 63 years (52 ± 6 years). All were candidates for heart transplantation. The 3-D reconstructions of the cardiovascular structures obtained from surgical anatomy data specific to TAH implantation allowed a volumetric measurement of these structures. A modeling diagram of these structures permitted reproducible quantitative measurements of the 35 geometrical parameters which characterized shape, orientation, and position of these structures within the thorax. Most of the measured parameters were characterized by low variability (coefficient of variation from 10 to 25%).

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Modélisation tridimensionnelle de l'anatomie du cur et des gros vaisseaux

Résumé Les contraintes anatomiques imposées au cur artificiel total (CAT) nécessitent des études anatomiques spécifiques. Une étude anatomique thoracique a été réalisée avec un scanner doté d'un logiciel de reconstruction tridimensionnelle (3-D) chez 15 patients, tous de sexe masculin, agés de 41 à 63 ans (52 ± 6 ans), et candidats à une transplantation cardiaque. Les reconstructions 3-D des structures cardio-vasculaires réalisées selon les données de l'anatomie chirurgicale propre à l'implantation du CAT ont permis la mesure volumétrique de ces structures. Un schéma de modélisation de ces structures a permis des mesures quantitatives reproductibles de 35 paramètres géométriques caractéristiques de la forme, de l'orientation, de la position de ces structures dans le thorax. Les résultats de ces mesures ont pu être exprimés en termes statistiques. La plupart des paramètres mesurés étaient caractérisés par une faible variabilité (coefficients de variations de 10 à 25%).

     

Frataxin is reduced in Friedreich ataxia patients and is associated with mitochondrial membranes

Friedreich ataxia is a progressive neurodegenerative disorder caused by loss of function mutations in the frataxin gene. In order to unravel frataxin function we developed monoclonal antibodies raised against different regions of the protein. These antibodies detect a processed 18 kDa protein in various human and mouse tissues and cell lines that is severely reduced in Friedreich ataxia patients. By immunocytofluorescence and immunocytoelectron microscopy we show that frataxin is located in mitochondria, associated with the mitochondrial membranes and crests. Analysis of cellular localization of various truncated forms of frataxin expressed in cultured cells and evidence of removal of an N-terminal epitope during protein maturation demonstrated that the mitochondrial targetting sequence is encoded by the first 20 amino acids. Given the shared clinical features between Friedreich ataxia, vitamin E deficiency and some mitochondriopathies, our data suggest that a reduction in frataxin results in oxidative damage.      

CD40 expression by gingival fibroblasts: correlation of phenotype with function

CD40, a member of the tumor necrosis factor-alpha receptor family, is constitutively expressed by cells of hematopoietic and non- hematopoietic origin, including fibroblasts. Signaling through this receptor molecule regulates inflammatory cytokine secretion by many cell types. Based on the recently described cytokine secretory heterogeneity of fibroblast cell subsets, we hypothesized that secretion of inflammatory cytokines by gingival fibroblast cultures may be dictated by the existence of differential proportions of cytokine- secreting subpopulations which express high levels of CD40. After examining a large number of gingival fibroblast (GF) cultures we find that the frequency of IL-6- and IL-8-secreting cells mirrors the frequency of cells expressing high levels of CD40 in these cultures. In addition, we demonstrate a direct functional relationship between CD40 expression and IL-6 or IL-8 secretion by showing that ligation of this molecule on GF, and CD40+ fibroblast subsets in particular, up- regulates secretion of these cytokines in vitro.      

How to use Chlamydia antibody testing in subfertility patients

Screening for tubal factor subfertility by means of Chlamydia antibody testing (CAT) was introduced into the initial work-up of subfertile couples several years ago. The results reported, however, are heterogeneous, and no uniformity exists in cut-off levels of titres, or in definitions of tubal factor subfertility. We performed a prospective cohort study to evaluate the implications of varying the definitions of tubal pathology and of modifying the cut-off levels on the clinical impact of CAT in predicting tubal factor subfertility. In 227 consecutive patients who attended our fertility clinic, the Chlamydia IgG antibody titre was determined and related to tuboperitoneal abnormalities at laparoscopy as a reference standard. According to received operating characteristic (ROC) curve analysis, a titre of 16 is the optimum cut-off level. Increasing the cut-off level improves specificity and positive likelihood ratio (LR+), at the expense of sensitivity and negative LR (LR-). Changing the definition of tubal factor subfertility from unspecified tuboperitoneal abnormalities into extensive adhesions and/or bilateral distal tubal occlusion improves LR+, LR- and kappa significantly. We conclude that CAT is more accurate in predicting severe distal tubal pathology than unspecified tuboperitoneal abnormalities. Although from a statistical point of view a titre of 16 is the optimum cut-off level, from a clinical point of view 32 or 64 may be preferable, depending on the aim of screening and the inception cohort.      

Screening for cognitive impairment in older African-Caribbeans

BACKGROUND: There are increasing numbers of older African-Caribbeans in the United Kingdom. Screening instruments are commonly used in the detection of cognitive impairment, but have not been assessed within this population. This study aimed to develop culturally modified versions of screening instruments for cognitive impairment (Mini-Mental State Examination (MMSE) and Abbreviated Mental Test (AMT)) and to determine their sensitivity and specificity in the diagnosis of dementia. METHODS: The instruments were modified using a process involving a community group of African-Caribbeans and an academic group of health professionals. They were used in a two-stage study involving community resident African-Caribbeans aged 60 years or over in inner-city Manchester, comparing the screening instruments against a computerized diagnostic interview. RESULTS: One hundred and thirty people completed the study. The results for the largest subgroup, the Jamaicans (N = 96) were analysed. Effects of gender, age and education on the MMSE and AMT scores were evaluated. The correlations between the screening instruments and diagnostic interview were highly significant (P < 0.001). At appropriate cut-offs both screening instruments demonstrated high sensitivity and acceptable specificity levels. CONCLUSIONS: A defined process with lay input has assisted in producing culturally modified versions of the MMSE and AMT that perform well compared with a diagnostic interview, if an appropriate cut-off is used. They are easy to administer and acceptable to older African-Caribbean people. The results need to be viewed within the limitations of the current study.     

Analysis of myocilin mutations in 1703 glaucoma patients from five different populations

A glaucoma locus, GLC1A, was identified previously on chromosome 1q. A gene within this locus (encoding the protein myocilin) subsequently was shown to harbor mutations in 2-4% of primary open angle glaucoma patients. A total of 1703 patients was screened from five different populations representing three racial groups. There were 1284 patients from primarily Caucasian populations in Iowa (727), Australia (390) and Canada (167). A group of 312 African American patients was from New York City and 107 Asian patients from Japan. Overall, 61 different myocilin sequence variations were identified. Of the 61 variations, 21 were judged to be probable disease-causing mutations. The number of probands found to harbor such mutations in each population was: Iowa 31/727 (4.3%), African Americans from New York City 8/312 (2.6%), Japan 3/107 (2.8%), Canada 5/167 (3.0%), Australia 11/390 (2.8%) and overall 58/1703 (3. 4%). Overall, 16 (76%) of 21 mutations were found in only one population. The most common mutation observed, Gln368Stop, was found in 27/1703 (1.6%) glaucoma probands and was found at least once in all groups except the Japanese. Studies of genetic markers flanking the myocilin gene suggest that most cases of the Gln368Stop mutations are descended from a common founder. Although the specific mutations found in each of the five populations were different, the overall frequency of myocilin mutations was similar ( approximately 2-4%) in all populations, suggesting that the increased rate of glaucoma in African Americans is not due to a higher prevalence of myocilin mutations.