Loss of Fhit expression in testicular germ cell tumors and intratubular germ cell neoplasia.

The FHIT gene, located at human chromosome 3p14.2, is frequently deleted in a number of human cancers, and interstitial deletions at this site were recently described in a significant proportion (41%) of testicular germ cell tumors. We studied the expression of Fhit protein in the progression and differentiation of testicular germ cell tumors to further elucidate its role in this type of malignancy. Forty-five patients with testicular germ cell tumors and intratubular germ cell neoplasia (identified in 42/45 cases) were included in the study. Immunohistochemical staining with polyclonal rabbit IgG antibody to Fhit (ZR44, Zymed Laboratories) on formalin-fixed, paraffin-embedded tissues was used. Fhit was constitutively expressed in germ cells, Sertoli cells, and Leydig cells. All 42 cases of intratubular germ cell neoplasia revealed no expression of this protein. No expression of Fhit was observed in any case of pure seminoma or in the seminomatous component of mixed germ cell tumors. Unexpectedly, Fhit expression was frequently (16/18) observed in the glandular tissue of mature teratomatous component of mixed germ cell tumors, despite the absence of Fhit in the intratubular germ cell neoplasia, the presumed precursor lesion. The loss of Fhit expression is a consistent characteristic of intratubular germ cell neoplasia, which suggests a potential role in a maturation/differentiation defect early in the development of testicular germ cell tumors. Likewise, the lack of expression in seminomas is supportive of this view. However, re-expression of Fhit in well-differentiated glandular epithelium of teratomatous component of mixed germ cell tumors suggests that there is no loss of FHIT gene in this subset of neoplasia but rather that Fhit protein expression is differently regulated through the phases of germ cell tumor progression.     

Shape,F-actin,and surface morphology changes during chemotactic peptide-induced polarity in human neutrophils

Background: The exposure of human neutrophils to uniform concentrations of chemoattractants, such as N-formyl peptides, induces morphological cell polarization. In this study we report the temporal sequence of changes in cell shape, F-actin, and cell surface morphology during cellular polarization induced by N-formylmethionyl-leucyl-phenyl-alanine (fMLP) in human neutrophils in suspension. Methods: Neutrophil shape changes induced by 10^?8 M fMLP were observed with DIC microscopy. Size and Cellular granularity were analyzed by flow cytometry measuring their forward and side scattered light. To visualize F-actin distribution, neutrophils were labeled with the fluorescence probe FITC-phalloidin, and were examined with fluorescence and confocal laser scanning microscopy. Cell surface morphology was assessed with scanning electron microscopy (SEM). Results: The stimulation of round-smooth neutrophils with nanomolar concentrations (10^?8 M) of fMLP in suspension induced a temporal sequence of morphological changes during cell polarization, characterized by 1) increase in size as determined by forward angle scattered light, 2) rapid redistribution of F-actin from a diffuse cytoplasmic localization to the cell periphery, and 3) rapid reorganization of cell surface morphological features, with accumulation of plasma membrane in the front of polar cells. Four cell shapes were identified with SEM after stimulation of round-smooth neutrophils: round-ridged, round-ruffled, nonpolar ruffled, and polar cells. These cell shapes were correlated with a cortical localization, focal aggregates, and multipolar distribution of F-actin. In polar neutrophils, F-actin became concentrated in the front of the cell. Conclusions: These findings show the relation between reorganization of the microfilamentous cytoskeleton and modifications in cell shape and surface features during cell polarization induced after fMLP activation in neutrophils. This approach offers a powerful tool for further analysis of receptor distribution in polarized, motile neutrophils. © 1995 Wiley-Liss, Inc.     

HLA allele and haplotype frequencies in Algerians : Relatedness to Spaniards and Basques

The powerful genetic polymorphism of the HLA system has been used to identify individuals and populations. Ethnic groups may be characterized by specific HLA allele frequencies and particular extended HLA haplotypes; also, genetic relationships among these groups may be deduced. In the present study, serology and DNA typing were used to detect HLA-A, -B, -C, -DR, and -DQ alleles in each individual and to calculae characteristic haplotypes in Algerians. These results were compared to those previously obtained in other populations, particularly northern Mediterraneans; genetic distances and their respective dendrograms place Basques and Spaniards closer to Algerians than to other Europeans. Also, characteristic Basque and/or Spanish haplotypes are found in Algerians; i.e., A30-B18-Cw3-DR3-DQ2 and Al-B57-Ctv7-DR7-DQ2. This supports the evidence that the Algerian population, mainly its paleo-North African component (Berbers), has a common descent with Basques and Spaniards, probably reflecting a preneolithic relationship between Iberians and paleo-North Africans.     

Molecular analysis of Bruton’s tyrosine kinase gene in Spain

Mutations in Bruton’s tyrosine kinase (BTK) gene result in X linked agammaglobulinemia (XLA). Using Single Strand Conformation Polymorphism (SSCP) followed by direct sequencing 21 mutations were found in 27 patients with an XLA phenotype from 21 unrelated families. We identified 13 novel and 8 known mutations: seven missense (R288W, R544G, P566S, K430E; K374N, L512P, R544S), 5 nonsense (Q196X, Y361X, L249X, Q612X, Q466X), 2 deletions of one nucleotide (A207fsX216, Q612fsX648), 2 deletion‐insertions (V219fsX227, K218fsX228), one insertion of two nucleotides (S572fsX587) and 4 point mutations in donor/acceptor splice sites (g.IVS1+1G>C, g.IVS6+5G>A, g.IVS10+1G>T, g.IVS13‐1GG>CT). Carrier detection was performed in 18 mothers. Only in one case the mutation was found to be de novo. Additionally, BTK mutations were not found in four patients without family history, but with XLA‐compatible phenotype. Hum Mutat 18:84, 2001. © 2001 Wiley‐Liss, Inc.     

New evidence from magnetic resonance imaging of brain changes after climbs at extreme altitude

The aim of the present study was to look for anatomical changes in climbers' brains, using magnetic resonance imaging (MRI), after extremely high-altitude climbs and to relate them to possible associated risk factors. Clinical history, neurological examinations and MRI were carried out on a group of nine climbers before and after climbing to over 7500 m without the use of supplementary oxygen. None of the subjects showed any neurological dysfunctions. In five climbers MRI abnormalities (high signal areas, cortical atrophy) were observed before the expedition. After the descent, two of them showed new high intensity signal areas recorded by MRI. Both subjects suffered severe neurological symptoms during the climb. The present study suggested that the brain changes observed by MRI could be related to the severity of clinical events at high altitude. However, we do not know the exact meaning of such MRI findings or the reason for their location, predominantly in posterior regions of the brain. The new evidence that a high percentage of climbers show MRI brain abnormalities, and especially the appearance of changes after the ascent, reinforces the possibility of a potential neurological risk in high-altitude climbing.     

Vicker's hardness and Raman spectroscopy evaluation of a dental composite cured by an argon laser and a halogen lamp

We present the results of the Vicker's hardness test and the use of near-infrared Raman spectroscopy (RS) to measure in vitro the degree of conversion (DC) of a bis(phenol)-A-glycidyl-dimethacrylate-based composite resin, photoactivated by both a halogen lamp (power density=478 mW/cm(2); 8-mm diameter spot) and an argon laser (power density=625 mW/cm(2); 7-mm diameter spot). The degree of conversion was estimated by analyzing the relative intensities between the aromatic C=C stretching Raman mode at 1610 cm(-1) and the methacrylate C=C stretching Raman mode (1640 cm(-1)) on top and bottom surfaces. For the hardness evaluation, the samples were embedded in polyester resin and three indentations with a 50-g load for 10 s were made on the top surface. The higher relative DC values achieved by the photoactivation of a composite resin by the argon laser suggest a better biocompatibility in the bottom surface. The correlation test showed that the higher Vicker's hardness number (VHN) values were associated with higher DC values. The derivative analysis showed a greater curing rate from 5 to 20 s of exposure. The comparison of VHN and DC values with both light sources at each curing time showed that a small change in conversion is related to a large change in hardness. Raman spectroscopy is more sensitive to changes in the first stages of curing reaction than later ones, and the Vicker's hardness assay is more sensitive to changes in the last stages.     

C7 complement deficiency in an Israeli Arab village

Deficiencies of terminal complement components, particularly the latter ones, are often detected because of increased susceptibility to Neisserial infections. Herein we document the first report of C7 deficiency among a highly inbred Arab population living in the lower Galilee region of Israel. Both biochemical and molecular analysis were performed on samples from infected survivors and parents of children who succumbed to Neisserial infections in a 4-year period. Only the index case who suffered recurrent infections and a sibling who had not suffered an infection during the outbreak were found to be C7-deficient. The mutation was found to be the one previously described to be prevalent among Israeli Jews of Moroccan ancestry (mutation G1135C). The implications of this finding are discussed in the context of family pedigree, the protective effect of complement deficiency, and the clinical outcome.