Gamma/deltaT-cell subsets, NKG2A expression and apoptosis of Vdelta2+ T cells in pregnant women with or without risk of premature pregnancy termination

PROBLEM: Potentially cytotoxic Vdelta2+ T lymphocytes recognize human leukocyte antigen-E on the trophoblast via their CD94/NKG2A receptors. This study aims at determing the percentage of gamma/delta T-cell subsets, their NKG2A and Annexin V positivity in peripheral blood of healthy pregnant women and women at risk of premature pregnancy termination. METHOD OF STUDY: Peripheral Vdelta2+ cells from healthy pregnant women and from women at risk of premature pregnancy termination were tested for the KIR NKG2A and Annexin V positivity by flow cytometry. RESULTS: The percentage of viable Vdelta2+ T cells was higher, that of Vdelta1+ T cells was lower in women at risk of premature pregnancy termination than in healthy pregnant women. The percentage of NKG2A + Vdelta2+ T cells was significantly lower in pregnant women at risk of premature pregnancy termination than in normal pregnancy. CONCLUSIONS: These data suggest the involvement of gamma/delta T lymphocytes in the pathogenesis of premature pregnancy termination.     

Mapping of α- and β-globin genes on Antarctic fish chromosomes by fluorescence in-situ hybridization

The pathways and mechanisms of genomic change that have led to the peculiar haemoglobinless phenotype of the white-blooded Antarctic icefishes (16 species in the family Channichthyidae) constitute an important model for understanding the rapid diversification of the Antarctic notothenioid fish flock. To provide complementary structural information on genomic change at globin-gene loci in Antarctic fish species, cytogenetic studies and in-situ chromosomal mapping have been undertaken. Using a DNA probe containing one α- and one β-globin gene from the embryonic/juvenile globin gene cluster of the red-blooded species Notothenia coriiceps, we mapped the cluster on the chromosomes of Antarctic teleosts by fluorescence in-situ hybridization. As anticipated on the basis of its molecular organization, the cluster was located on a single chromosome pair in all of the red-blooded fish species probed (N. coriiceps, N. angustata, Trematomus hansoni, T. pennellii). In contrast, the α/β-globin probe did not recognize complementary sequences on the chromosomes of the white-blooded species Chionodraco hamatus and Channichthys rhinoceratus. These results represent the first example of chromosomal mapping of embryonic/juvenile globin genes in teleostean fishes. Beyond its relevance to the evolutionary history of Antarctic notothenioids, this work contributes to our understanding of the evolution of the chromosomal loci of globin genes in fishes and other vertebrates. This revised version was published online in July 2006 with corrections to the Cover Date.     

Microvascular structural entropy: A novel approach to assess angiogenesis in pituitary tumors

Entropy, a measure of the degree of disorder in a system, has recently been used in different morphologic studies to quantify regularity. Our aims were (a) to study the structural organization of the microvascular bed in prolactin (PRL)-producing adenomas and carcinomas, the most vascularized of pituitary tumors, by assessing microvascular structural entropy (MSE), and (b) to determine whether the degree of disorder of the capillary bed correlates with tumor cell proliferation as estimated by MIB-1 labeling, microvessel density (MVD), the most widely used method of quantifying blood vessel formation, and various clinicopathologic parameters (gender, age, tumor size and invasiveness). The morphometric study demonstrated statistically significant differences in MIB-1 labeling, MVD, and MSE between PRL-producing adenomas and carcinomas. Unlike MIB-1 labeling index (PRL-producing adenomas 1.5±0.27; carcinomas 15.0±4.04) and MVD (PRL-producing adenomas 2.7±0.34; carcinomas 4.2±0.72), the MSE values were significantly higher in adenomas (171.5±25.37) than in carcinomas (67.9±17.45). These results indicate that PRL-producing carcinomas have a less chaotic distribution of vessels than benign adenomas. In contrast to a lack of correlation between, microvessel density and other morphometric parameters, a strong negative correlation was found between MSE and MIB-1 labeling index (r=0.511, p=0.003). It thus appears that regular, less chaotic microvascular geometry contributes to increased proliferative activity in PRL cell tumors. Analysis of MSE may provide an independent parameter of tumor behavior, and contributes to a better understanding of the role of microvasculature in pituitary tumor progression.     

A nonparametric two-sample comparison for skewed data with unequal variances

ObjectiveThe aim of the study was to recommend a statistical test for the situation in which unequal variances are accompanied by skewed distributions. A previous publication in this journal could not recommend any test; instead, transformations were suggested.Study Design and SettingA recently introduced generalized Wilcoxon test is presented, which can be applied when variances may be unequal and the distribution may be skewed. This test examines the null hypothesis that the relative effect is 0.5. Its type I error rate was investigated in a simulation study.ResultsThe generalized Wilcoxon test was already recommended for various areas of life sciences and, very recently, it was shown that a permutation test could be performed with the generalized test statistic. Simulation results indicate an acceptable control of the type I error rate even for extreme variance ratios.ConclusionThe generalized Wilcoxon test should be applied when it cannot be assumed that variances are equal and that the distribution is symmetric. This test is preferable to a transformation, because the use of transformations can be problematic, in particular when sample sizes are small.     

Mutations of CD40 ligand in two patients with hyper-IgM syndrome

Two patients with the X-linked form of the hyper-IgM syndrome have been studied. Both patients present: 1. Mutations in the CD40L gene (a nonsense point mutation that introduces a termination codon at the extracellular domain of the protein, and a deletion that eliminates exon 4 as consequence of an abnormal splicing). 2. Lack of CD40L expression on the lymphocyte surface after stimulation with ionomycin and PMA. 3. Altered lymphocytic proliferation in response to anti-CD3. 4. Hyper IgM, low IgG and IgA levels and neutropenia. One of the patients shows, in addition, low Natural Killer cell numbers and severe herpetic infections, which distinguishes this case from the common hyper-IgM syndrome phenotype. Finally, a hyper-IgM stable phenotype has been immortalized by Herpes virus Saimiri for the first time.     

Compliance with oral HRT in postmenopausal women in clinical trials--meta analysis

OBJECTIVE: To assess compliance with oral hormone replacement therapy (HRT) over time in postmenopausal women in clinical trials and to examine aspects of study conduct (e.g. randomized vs. nonrandomized design) that might be associated with observed compliance rates. METHODS: Aggregation of data from the available published studies using meta-analysis. Eligible studies had to be clinical trials reporting compliance with oral HRT among postmenopausal women and have a sample size of at least 20. MEDLINE and EMBASE databases were used through January 1998 to find studies that assessed compliance with oral HRT in postmenopausal women in clinical trials. Summary estimates of compliance, and of associations between compliance and features of study conduct, were computed allowing for clustering of data within studies. RESULTS: Thirty reports met the inclusion criteria. Overall compliance at about 1 year on average was 83.4%. In a multivariable model, one variable, whether compliance was the primary objective of the study or not, remained statistically significant, even after adjustment for clustering (odds ratio=0.47, 95% confidence interval: 0.22-1.00, P=0.05). CONCLUSIONS: This study supports the importance of using appropriate methods for measuring compliance, if valid estimates of compliance are a serious objective of an investigation. There has been much discussion about the need for increased medication compliance, particularly for those medications used for prevention, but the means and methods to improve compliance remain elusive.     

Chlamydophila (Chlamydia) pneumoniae induces histidine decarboxylase production in the mouse lung

Chlamydophila (Chlamydia) pneumoniae (C. pneumoniae) is the third most common cause of community-acquired pneumonia and is probably involved in the development of certain chronic inflammatory diseases, including atherosclerosis and adult-onset asthma. Histamine, synthesized by histidine decarboxylase (HDC) from L-histidine, plays an essential role in allergic and inflammatory processes and in cell differentiation. The effect of C. pneumoniae infection on the expression of HDC has not been examined. In the present study, normal Balb/c mice and HDC knockouts, and control mice with a CD1 background were infected intranasally with C. pneumoniae. On days 1, 3, 7, 16 and 31 after infection, the normal Balb/c mice were sacrificed and divided into three groups. In the homogenized lungs of the first group, C. pneumoniae titres were determined and demonstrated peak levels on day 7. HDC production was revealed by a Western blot assay throughout the observation period of 1-16 days, and cytokine concentrations were determined by ELISA. The interleukin-3 (IL-3) and interleukin-6 (IL-6) levels were highest on day 1 and on days 1-3, respectively; the interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) levels reached the maximum on day 7, but the quantity of IL-4 was still three times higher than that in the control group 16 days after infection. The lungs of the mice in the second group were processed for the in situ demonstration of HDC activity, while the lungs in the third group were stained for C. pneumoniae antigen. The HDC activity was increased predominantly in the bronchial epithelial cells, while C. pneumoniae antigens were expressed especially in the interstitial macrophages. The HDC knockout mice exhibited a higher survival rate after C. pneumoniae infection than did the control mice. These results point to a strong association between local histamine production and other inflammatory mediators and are novel in demonstrating the role of histamine in the pathomechanism of C. pneumoniae infections.