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.      

Long-term deficits after somatosensory cortical lesions in rats.

Rats having either sham operations or one-stage bilateral lesions of the two somatosensory areas of the cortex were tested for acquisition of five tactile discriminations after postoperative recovery intervals of 14, 35, 180, 365 or 730 days. The group with lesions performed worse than its time-matched control group in every instance, and there was no evidence for recovery of function with the longer postoperative recovery periods. These results suggest that time per se is not a significant determinant of restitution after somatosensory cortical ablations.     

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.      

Die sogenannte Impfwut

Zusammenfassung Die im Verlaufe antirabischer Vaccinationen gelegentlich auftretenden paralytischen Komplikationen sind nicht virusbedingt, sondern die Folge einer Antigen-Antikörperreaktion nach Sensibilisierung mit dem organspezifischen Hirnantigen, das in den nicht ätherisierten Tollwutvaccinen enthalten ist. Diesbezüglich von einer Impfwut zu sprechen, erscheint nicht gerechtfertigt. Vielmehr sollte dieser Terminus für die postvaccinalen Komplikationen reserviert bleiben, bei denen der Ausbruch der Erkrankung in direktem Kausalzusammenhang zu dem in einer Vaccine enthaltenen lebenden Virus fixe steht.     

Alternative splicing of exon 14 determines nuclear or cytoplasmic localisation of fmr1 protein isoforms

Impaired expression of the FMR1 gene is responsible for the fragile X mental retardation syndrome. The FMR1 gene encodes a cytoplasmic protein with RNA-binding properties. Its complex alternative splicing leads to several isoforms, whose abundance and specific functions in the cell are not known. We have cloned in expression vectors, cDNAs corresponding to several isoforms. Western blot comparison of the pattern of endogenous FMR1 proteins with these transfected isoforms allowed the tentative identification of the major endogenous isoform as ISO 7 and of a minor band as an isoform lacking exon 14 sequences (ISO 6 or ISO 12), while some other isoforms (ISO 4, ISO 5) were not expressed at detectable levels. Surprisingly, in immunofluorescence studies, the transfected splice variants that exclude exon 14 sequences (and have alternate C-terminal regions) were shown to be nuclear. Such differential localisation was however not seen in subcellular fractionation studies. Analysis of various deletion mutants suggests the presence of a cytoplasmic retention domain encoded in exon 14 and of a nuclear association domain encoded within the first eight exons that appear however to lack a typical nuclear localisation signal.      

Einflu\ vonBordetella pertussis auf das lymphatische Gewebe von Mäusen

Zusammenfassung Verglichen mit phänotypisch normalen Kontrolltieren fanden sich bei NMRI-Mäusen mit kongenitaler Thymusaplasie nur wenige Peyersche Plaques, die zudem nur aus diffusen Lymphocytenansammlungen bestanden. Auch die Milzfollikel waren erheblich verkleinert, wobei die periarteriolären Follikelbereiche gelegentlich zellärmer erschienen. Das wei\e Blutbild der thymuslosen Tiere war durch eine mä\ige Lymphopenie charakterisiert. Obwohl die Milzen der Mäuse mit kongenitaler Thymusaplasie keine Verringerung der Zahlen an präexistenten 19S-Hämolysin-bildenden Zellen aufweisen, waren nach Erstimmunisierung mit 4·10⁸ Schaferythrocyten nur minimale Zahlen an 19S-Produzenten und 7 S-Produzenten nachweisbar. Die sekundäre antigene Stimulierung mit 4·10⁸ Schaferythrocyten führte zu keiner nennenswerten Gedächtnisreaktion, was anzeigt, da\ die Bildung von Gedächtniszellen ein thymusabhängiger Proze\ ist. Die alleinige intraperitoneale Injektion abgetöteter Zellen von B. pertussis führte zu Hypersplenie, Leukozytose und Vermehrung der präexistenten Zahlen an 19S-Hämolysin-bildenden Zellen. Im Gegensatz zu Normaltieren, wo die Leukocytose durch eine Vermehrung von Granulocyten und Lymphocyten charakterisiert ist, fehlte bei den thymuslosen Tieren die Lymphocytenvermehrung. Der Zunahme der Blutgranulocyten entsprach eine verstärkte Granulopoese in Leber und Milz. Bei Normaltieren fand sich nach Erstimmunisierung durch simultane Applikation von 4·10⁸ Schaferythrocyten und 3·10⁹ abgetöteten Zellen vonB. pertussis eine verstärkte und verlängerte Produktion von 19S- und besonders 7S-Hämolysin-bildenden Zellen, verbunden mit einer verstärkten Präparation des lymphoretikulären Gewebes für die anamnestische Reaktion. Bei den Mäusen mit kongenitaler Thymusaplasie beschränkte sich der Adjuvanseffekt allem auf die Frühphase der immunologischen Primärreaktion, was seinen Ausdruck in einer deutlichen Vermehrung der 19S-Produzenten und einer nur geringgradigen Vermehrung der 7S-Produzenten fand.

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Influence ofBordetella pertussis on the lymphatic tissue of miceVIII. The influence ofBordetella pertussis on the primary and secondary immune potential of thymusless (nude) mice

As compared to phenotypically normal controls, in the intestine of NMRI mice with congenital aplasia of the thymus (nude) only small numbers of Peyer's patches could be detected, which consisted of relatively diffuse accumulations of lymphocytes. The splenic follicles were likewise considerably reduced in size, whereby the thymus-dependent areas occasionally appeared to be deficient in lymphocytes. Furthermore, the thymusless mice were found to have blood lymphopenia. Although the spleens of nude mice contained rather enhanced numbers of pre-existing 19S hemolysin forming cells, only small numbers of 19S producers and very poor numbers of 7S hemolysin-forming spleen cells were demonstrable after the primary immunization with 4·10⁸ sheep erythrocytes. Secondary antigenic stimulation with an equal dose of the erythrocyte antigen did not result in a noteworthy secondary immune response. This evidently indicates that the production of memory cells is a thymus-dependent process. A single intraperitoneal injection of 3·10⁹ pertussis organisms led to splenomegaly, blood leukocytosis and augmentation of the pre-existing 19S hemolysin-forming spleen cells. Whilst in normal controls the blood leukocytosis was found to be due to an increase in both lymphocytes and granulocytes, in nude mice the leukocytosis was solely caused by the increase in granulocytes, this being associated with increased granulopoiesis in spleen and liver. The primary immunization of normal controls with 4·10⁸ sheep erythrocytes and 3·10⁹ pertussis organisms led to an increased and prolonged development of both 19S and 7S hemolysin-producing spleen cells. Furthermore, the bacterial adjuvant increased the process of priming for the secondary immune response. Unlike to this, in mice with congenital aplasia of the thymus adjuvancy of pertussis organisms was restricted to the early phase of the primary immune response, as is documented by the distinct augmentation of 19S producers and a poor increase in the numbers of 7S hemolysin-forming spleen cells.

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Diese Arbeit wurde durch die Deutsche Forschungsgemeinschaft gefördert.     

Needle biopsy of renal allografts: comparison of two techniques

Two techniques for renal allograft biopsy were retrospectively evaluated to compare relative safety and efficacy. After ultrasound (US) localization of the kidney and biopsy with a hand-held 14-gauge cutting needle, an adequate specimen was obtained in 74 of 77 cases (96%). Major complications occurred in six of these 77 cases (8%). One hundred four biopsies were performed by using a smaller 18-gauge cutting needle with a spring-loaded biopsy "gun" and real-time US guidance. With this newer technique, specimens adequate for diagnosis were obtained in 99 biopsies (95%). There was a single major complication with this technique (1%). The 18-gauge needle with real-time US guidance yields comparably adequate specimens with a lower frequency of complications.     

胰腺多房性潴留性囊肿1例

0　引言　胰腺多房性潴留性囊肿极为罕见,我科收治1例,报道如下.1　病例报告　患者,男,29岁,因发现右上腹包块11d入院,缘于11d前无明显诱因感右上腹痛,仅局限于右上腹部,无肩背部放散痛,伴间歇性发热,体温最高达38.3℃,经抗炎,对症治疗无效.并逐渐可触及右上腹有一肿块,在当地医院行穿刺检查为脓血性液体.镜检发现炎性细胞,B超示:胆囊窝下方及右肾内侧及腹腔动脉,下腔静脉外前方可见异常区,大小约9.1cm×6.6cm×7.6cm,边界清楚,形态不规则,内呈蜂窝状,可见多个大小不等的液性暗区,CT示:右上腹部上腔静脉前方6.0cm×9.0cm肿块和周围组织粘…     

IMPACTED RIGHT UPPER CENTRAL INCISOR AND TRANSPOSITION OF TWO OTHER ANTERIOR TEETH ON THE SAME SIDE (A Case Report)

A young boy presented with an uncommon finding of impaction of upper right central incisor and transposition of canine and lateral incisor on the same side. Esthetic management of his cosmetic problem which included fixed appliance therapy followed by light cure restorations is discussed.KEY WORDS: Impaction, Transposition