Common variable immunodeficiency: the immune system in chaos

Common variable immunodeficiency (CVID) is a heterogeneous disorder that is associated with low serum-immunoglobulin concentrations, defective specific-antibody production and an increased susceptibility to bacterial infections of the respiratory and gastrointestinal tracts. In spite of the identification of genes that are associated with several known primary immunodeficiencies, the basic immunologic and molecular defects of the majority of patients with CVID have remained obscure. Most of the studies aimed at understanding the immunopathogenesis of CVID suggest that this condition is primarily a T-cell disorder, although renewed attention on the genetic linkage and haplotype analysis in families of patients with CVID and on the role of dendritic cells and B cells has revealed several interesting features. This new information should assist in understanding the pathogenesis of CVID and improving the therapeutic strategies.     

Implication of protein kinase C in the regulation of DNA mismatch repair protein expression and function

The DNA mismatch repair (MMR) proteins are essential for the maintenance of genomic stability of human cells. Compared with hereditary or even sporadic carcinomas, MMR gene mutations are very uncommon in leukemia. However, genetic instability, attested by either loss of heterozygosity or microsatellite instability, has been extensively documented in chronic or acute malignant myeloid disorders. This observation suggests that in leukemia some internal or external signals may interfere with MMR protein expression and/or function. We investigated the effects of protein kinase C (PKC) stimulation by 12-O-tetradecanoylphorbol-13-acetate (TPA) on MMR protein expression and activity in human myeloid leukemia cell lines. First, we show here that unstimulated U937 cells displayed low level of PKC activity as well as MMR protein expression and activity compared with a panel of myeloid cell lines. Second, treatment of U937 cells with TPA significantly increased (3-5-fold) hMSH2 expression and, to a lesser extent, hMSH6 and hPMS2 expression, correlated to a restoration of MMR function. In addition, diacylglycerol, a physiological PKC agonist, induced a significant increase in hMSH2 expression, whereas chelerythrine or calphostin C, two PKC inhibitors, significantly decreased TPA-induced hMSH2 expression. Reciprocally, treatment of HEL and KG1a cells that exhibited a high level of PKC expression, with chelerythrine significantly decreased hMSH2 and hMSH6 expression. Moreover, the alteration of MMR protein expression paralleled the difference in microsatellite instability and cell sensitivity to 6-thioguanine. Our results suggest that PKC could play a role in regulating MMR protein expression and function in some myeloid leukemia cells.     

Multivariate genetic analysis of maximal isometric muscle force at different elbow angles

Thomis, Martine A., Marc Van Leemputte, Hermine H. Maes,Cameron J. R. Blimkie, Albrecht L. Claessens, Guy Marchal, Eustachius Willems, Robert F. Vlietinck, and Gaston P. Beunen. Multivariate genetic analysis of maximal isometric muscle force at different elbowangles. J. Appl. Physiol. 82(3):959-967, 1997.The maximal isometric moment at five differentelbow joint angles was measured in 25 monozygotic and 16 dizygotic maleadult twin pairs (22.4 ± 3.7 yr). Genetic model fittingwas used to quantify the genetic and environmental contributions toindividual differences in isometric strength. Additive genetic factorsexplained 66-78% of the variance in maximal torque at170-140-110 and 80° flexion (extension = 180°). At50° flexion, common and subject-specific environmental factorscontributed equally to the variation. The contribution of uniqueenvironmental factors concurs with the level of variability in muscleactivation and (dis)-comfort of torque production in the specificangle. The relative contribution of lever arm and force-lengthrelationship in torque varies according to the angle. Because thesefactors might be genetic, this variability is reflected in the geneticcontribution at the extreme angles of 170 and 50°. Multivariateanalyses suggested a general set of genes that control muscle area andisometric strength, together with a more specific strength factor.Genetic correlations were high (0.82-0.99). Genes responsible forarm-segment lengths did not contribute to muscle area nor to isometricstrength.

     

Case-control cohort study of patients' perceptions of disability in mastocytosis

Background

Indolent forms of mastocytosis account for more than 90% of all cases, but the types and type and severity of symptoms and their impact on the quality of life have not been well studied. We therefore performed a case-control cohort study to examine self-reported disability and impact of symptoms on the quality of life in patients with mastocytosis.

Methodology/Principal Findings

In 2004, 363 mastocytosis patients and 90 controls in France were asked to rate to their overall disability (OPA score) and the severity of 38 individual symptoms. The latter was used to calculate a composite score (AFIRMM score). Of the 363 respondents, 262 were part of an ongoing pathophysiological study so that the following data were available: World Health Organization classification, standard measures of physical and psychological disability, existence of the D816V KIT mutation, and serum tryptase level. The mean OPA and AFIRMM scores and the standard measures of disability indicated that most mastocytosis patients suffer from disabilities due to the disease. Surprisingly, the patient''s measurable and perceived disabilities did not differ according to disease classification or presence or absence of the D816V KIT mutation or an elevated (≥20 ng/mL) serum tryptase level. Also, 32 of the 38 AFIRMM symptoms were more common in patients than controls, but there were not substantial differences according to disease classification, presence of the D816V mutation, or the serum tryptase level.

Conclusions

On the basis of these results and for the purposes of treatment, we propose that mastocytosis be first classified as aggressive or indolent and that indolent mastocytosis then be categorized according to the severity of patients'' perceived symptoms and their impact on the quality of life. In addition, it appears that mastocytosis patients suffer from more symptoms and greater disability than previously thought, that mastocytosis may therefore be under-diagnosed, and that the symptoms of the indolent forms of mastocytosis might be due more to systemic release of mediators than mast cell burden.     

Die ontogenetischen Abänderungen des diplophyllen Grundbaues der Staubblätter

Zusammenfassung Die verschiedenen Formen der fertigen Angiospermen-Staubblätter sind bloß quantitative Varianten der diplophyllen Anlage. Bei ungestörter isodiametrischer Weiterentwicklung wird diese zu einem Staubblatt mit einer introrsen, basifixen Anthere, das uns somit den Typus des Angiospermen-Staubblattes repräsentiert. Durch nachträgliche Förderung der Ventralspreite entstehen äquifaziale und extrorse Antheren, durch verschiedenes Auswachsen der Antherenbasis dorsifixe, ventrifixe, zentrifixe und pfeilförmige Antheren und durch ungleiche seitliche Entwicklung der symmetrischen Anlage die asymmetrischen Staubblätter mit gehemmten Theken.     

Über die „primitivste“ Karpellform

Ohne Zusammenfassung     

Die Bedeutung der diplophyllen Übergangsblätter für den Bau der Staubblätter

Zusammenfassung Mit Hilfe von trichterförmigen und doppelspreitigen Übergangsblättern zwischen Krön-und Staubblättern konnte gezeigt werden, daß auch jene Staubblätter, die in ihrer Ontogenese kein schildförmiges Ausgangsstadium erkennen lassen, sondern vielmehr von Anfang an vierkantig auftreten, trotzdem peltat und zwar diplophyll gebaut sind. Die Übergangsblätter ermöglichen diesen Nachweis entweder dadurch, daß sie als groß-gewordene Zwischenformen der ontogenetischen Entwicklung eine geschlossene Entwicklungsreihe der Staubblattgestalt vor Augen führen, oder aber dadurch, daß sie den diplophyllen Bau des fertigen Staubblattes auffällig machen.Durch diese Aufdeckung der Peltation auch bei den Staubblättern, die dem Anschein nach nicht peltat sind, wird offensichtlich, daß allen Staubblättern der Angiospermen ein einheitlicher peltater Grundbauplan zugrunde liegt.     

Harnstoff-Permeabilität der Epidermis etiolierter und ergrünender Blätter

Ohne Zusammenfassung