Characterization of cortical neuron outgrowth in two- and three-dimensional culture systems

To improve the ability of regeneration by grafting living cells or by adding growth factor to a lesion site, it is important to find good biomaterials for neuron survival and regeneration. This study focused on two- and three-dimensional cultures in a matrix using biomaterials such as agarose, collagen, fibrin, and their mixtures, because these are considered to be suitable biomaterials for neuron outgrowth. Cortical neurons were dissected from E17 rat embryos and cultured in agarose gel, collagen gel, fibrin glue, and mixtures of collagen and fibrin. Results showed that neurons cultured in collagen gel and fibrin glue had longer periods of survival (more than 3 weeks) and better neurite extension than those observed in agarose gels. As to the survival rate according to the MTT and lactate dehydrogenase assays, fibrin glue was the most suitable biomaterial for neuron survival among the biomaterials examined. With two-dimensional fibrin plating, neuron cells exhibited cell aggregation and stress fibers, but the same results were not observed with collagen gel. There were no differences in neurite extension and survival in the mixtures of collagen and fibrin. The results suggest that collagen and fibrin can provide a suitable substrate for a three-dimensional culture matrix for neuronal survival and differentiation.     

Localization of the novel Xin protein to the adherens junction complex in cardiac and skeletal muscle during development.

Previously, we demonstrated that chick embryos treated with antisense oligonucleotides against a striated muscle-specific Xin exhibit abnormal cardiac morphogenesis (Wang et al. [1999] Development 126:1281-1294); therefore, we surmised a role for Xin in cardiac development. Herein, we examine the developmental expression of Xin through immunofluorescent staining of whole-mount mouse embryos and frozen heart sections. Xin expression is first observed within the heart tube of embryonic day 8.0 (E8.0) mice, exhibiting a peripheral localization within the cardiomyocytes. Colocalization of Xin with both beta-catenin and N-cadherin is observed throughout embryogenesis and into adulthood. Additionally, Xin is found associated with beta-catenin within the N-cadherin complex in embryonic chick hearts by coimmunoprecipitation. Xin is detected earlier than vinculin in the developing heart and colocalizes with vinculin at the intercalated disc but not at the sarcolemma within embryonic and postnatal hearts. At E10.0, Xin is also detected in the developing somites and later in the myotendon junction of skeletal muscle but not within the costameric regions of muscle. In cultured C2C12 myotubes, the Xin protein is found in many speckled and filamentous structures, coincident with tropomyosin in the stress fibers. Additionally, Xin is enriched in the regions of cell-cell contacts. These data demonstrate that Xin is one of the components at the adherens junction of cardiac muscle, and its counterpart in skeletal muscle, the myotendon junction. Furthermore, temporal and spatial expressions of Xin in relation to intercalated disc proteins and thin filament proteins suggest roles for Xin in the formation of cell-cell contacts and possibly in myofibrillogenesis.     

A polymorphism in the angiotensin 1-converting enzyme gene is associated with damage to cerebral cortical white matter in Alzheimer's disease

The impact of the insertion (I)/deletion (D) (I/D) polymorphism in the angiotensin 1-converting enzyme (ACE) gene on the extent of white matter myelin loss (ML) was investigated in four regions of the cerebral cortex in an autopsy-confirmed series of 93 patients with Alzheimer's disease (AD). The possible influence of APO E epsilon4 allele acting in concert with ACE D allele was assessed. The extent of ML did not differ between D/D, I/D and I/I genotype groups when data from all four brain regions were combined. However, separate analysis showed that the frontal and temporal cortex tended to be affected more severely by ML in patients with D/D genotype compared to those with I/D and I/I genotypes. Stratification according to APO E epsilon4 allele revealed a greater overall ML in patients bearing at least one copy of ACE D allele and one APO E epsilon4 allele, especially in individuals homozygous for both. The APO E epsilon4 allele may therefore act synergistically in patients with AD (and other subjects) bearing ACE D/D genotype to increase the risk of ML, perhaps through transient ischaemic episodes consequent upon poor cardiac output associated with coronary atherosclerosis in patients with the APO E epsilon4 allele.     

Pontine veins. MRI cross-sectional anatomy

Summary The pons is covered by a rich venous network offering numerous vascular landmarks in MRI and during surgery. We present an original study of the veins as they appear on MR multiplanar scans after gadolinium IV injection. This prospective study is based on 40 consecutive patients with normal posterior fossa structures. One of the major venous collectors follows the pons: the superior petrosal v. was identified on MRI in 95% of our cases. Its hooklike extremity drains into the superior petrosal sinus. The inferior petrosal v. was never identifiable. The superficial pontine venous network are identified in 72.5% of cases in the axial plane and were organised in longitudinal and transverse collectors, whose MR aspects are presented here.

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Les veines du pont. Anatomie sectionnelle en IRM

Résumé Le pont, enveloppé des citernes subarachnoïdiennes, est parcouru à sa surface par de nombreux vaisseaux qui constituent autant de points de repère topographiques en IRM que de rapports chirurgicaux. Nous présentons une étude de l'anatomie veineuse en coupe telle que l'IRM la révèle après injection de Gadolinium. Cette étude prospective comporte 40 patients indemmes de lésion de la fosse crânienne postérieure. Le pont est longé par un des collecteurs majeurs du tronc cérébral : la v. pétreuse supérieure, identifiée dans 95 % des cas. Elle se jette par un crochet caractéristique dans le sinus pétreux supérieur. La v. pétreuse inférieure n'a jamais été reconnue. Les vv. pontiques forment un réseau maillé visible dans 72,5 % des cas en coupes axiales et comportant des axes transversaux et longitudinaux dont les critères d'identification sont présentés selon le plan de coupe.

     

IL-12 inhibits in vitro immunoglobulin production by human lupus peripheral blood mononuclear cells (PBMC)

Systemic lupus erythematosus (SLE) is a prototypical autoimmune disease characterized by polyclonal B cell activation and by the production of anti-double-stranded (ds) DNA antibodies. Given the inhibitory effects of IL-12 on humoral immune responses, we investigated whether IL-12 displayed such an activity on in vitro immunoglobulin production by SLE PBMC. Spontaneous IgG, IgG1, IgG2, IgG3 and IgM antibody production was dramatically reduced by addition of IL-12. These results were confirmed by Elispot assays detecting IgG- and anti-dsDNA-secreting cells. While IL-6 and TNF titres measured in PBMC supernatants were not modified by addition of IL-12, interferon-gamma (IFN-γ) titres were up-regulated and IL-10 production down-regulated. Since addition of IFN-γ did not down-regulate immunoglobulin production and since the inhibitory activity of IL-12 on immunoglobulin synthesis was not suppressed by anti-IFN-γ antibody, we concluded that the effect of IL-12 on immunoglobulin production was not mediated through IFN-γ. Our data also argue against the possibility that down-regulation of endogenous IL-10 production was responsible for the effect of IL-12. Thus, inhibition of IL-10 production by IFN-γ was not accompanied by inhibition of immunoglobulin production, and conversely, restoration of IL-10 production by anti-IFN-γ antibody did not suppress the inhibitory activity exerted by IL-12 on immunoglobulin production. Taken together, our data indicate that reduction of excessive immunoglobulin and anti-dsDNA antibody production by lupus PBMC can be achieved in vitro by IL-12, independently of IFN-γ and IL-10 modulation.     

Serum hepatitis B virus DNA in healthy HBsAg-negative Chinese adults evaluated by polymerase chain reaction

Serum hepatitis B virus (HBV) DNA was assayed using polymerase chain reaction, in 107 HBsAg-negative normal Chinese subjects. The results showed that eight subjects (7.5%) had HBV DNA. In the subgroup with antibody to hepatitis B surface antigen (anti-HBs) and to hepatitis B core antigen (anti-HBc), 7.3% (5/68) were positive for HBV DNA; HBV DNA was not detected in six individuals with anti-HBs only and in nine with anti-HBc only. In four persons with anti-HBc and anti-HBe, one had HBV DNA. In 20 subjects negative for all hepatitis B serological markers, two (10%) were found to have HBV DNA. This study indicates that serological markers are not adequate to rule out HBV infection, and it further implies that present blood donor screening methods may need improving.     

A survey of different high resolution visualization modes of a volumetric object with applications

Summary In view of the variety of 3D representation techniques, a clinical study was carried out in order to evaluate their respective usefulness. It appears that a single technique cannot be claimed to be valid for all clinical situations and that a combination of representations brings more relevant information. Among the different techniques a clear delineation must be established between those which allow the accurate definition of landmarks (multiplanar reformation, surface representation), and those which do not (integral shading, reconstructed radiology). The main point is the possibility to recognize anatomical landmarks on these latter modes and to choose oblique cut planes in relation to them. Visualization quality is strongly dependent upon the acquisition protocol which must provide a spatial resolution as isotropic as possible.

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Une revue de différents modes de visualisation en haute résolution d'un objet volumique avec des applications

Résumé Face à la variété des techniques de représentation 3D une étude clinique a été conduite pour évaluer leurs utilités respectives. Il apparait qu'une technique unique ne peut pas convenir à toutes les situations cliniques et qu'une combinaison de différents modes de présentation apporte une information plus pertinente. Parmi les différentes techniques une distinction claire doit être établie entre celles qui autorisent la prise de repères précis (reformatage multiplanaire, représentation de surface), et celles qui ne le permettent pas (ombrage intégral, radiologie reconstruite). Le point principal est la possibilité de reconnaître des repères anatomiques sur ces derniers modes et de choisir des plans de coupe en relation avec eux. La qualité de la visualisation dépend étroitement du protocole d'acquisition qui doit fournir une résolution aussi isotrope que possible.

     

Biomarkers for toxicity and metabolic abnormalities of the main severe poisonings. Clinical and toxicologic symptoms. Conservative determination

The members of the joint group "Toxicology and Clinical Biology" of the French Society of Clinical Biology (SFBC), the French Society of Analytical Toxicology (SFTA), and the Society of Clinical Toxicology (STC), suggest guidelines to meet the requirements of clinical biologists who are not specialized in toxicology. Based on good laboratory practice they propose a number of guidelines. Three synthetic tables have been established. They are not only toxicity biomarkers and metabolic disorders associated with the main severe intoxications, but also clinical signs that are observed during these intoxications, finally biological sampling as a precautionary measure. The table also takes into account approximately fifty xenobiotics: main clinical signs emergency, identification or quantification of the suspected product, useful biological markers, therapeutic, quantitations necessary to take into consideration patient care, and poison antidotes, are described. Recommendations regarding medical and forensic techniques are also proposed by the group. It is also necessary to collect and store biological samples when the individual patients are in charge. These samples will be analyzed or not depending on the individual case history.     

Hyperplasia and tumors of the parathyroid glands

Zusammenfassung Die verschiedenen Formen des Hyperparathyreoidismus werden überwiegend von Hyperplasien und Adenomen der Nebenschilddrüsen verursacht. Während früher die Diagnose des Pathologen (meist schon im intraoperativen Gefrierschnitt) für das chirurgische Vorgehen maßgebend war, wird das Operationsausmaß heute überwiegend durch die wesentlich verbesserte präoperative Diagnostik bestimmt (bildgebende Verfahren) und durch den nach der Entfernung der vergrößerten Nebenschilddrüse(n) intraoperativ gemessenen Abfall des Parathormons kontrolliert. Nichtsdestotrotz sollte dem Pathologen die morphologische Differenzialdiagnose der Hyperplasie, des Adenoms und Karzinoms der Nebenschilddrüsen geläufig sein.

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