[Characterisation of viral agents with potential to cause diarrhea in Djibouti]. / Caractérisation des virus agents potentiels des diarrhées chez l'adulte à Djibouti.

Due to limited laboratory facilities in the tropics, the exact role of enteric viruses in causing diarrhea among adults in the tropics is unknown. The purpose of this report is to describe a multicenter study undertaken in Djibouti to determine the prevalence of a large panel of enteric viruses using immunochromatography; antigenic detection by ELISA, RT-PCR cellular inoculation, sequence analysis; and indirect serology. Study samples were collected from 108 patients presenting acute and sporadic diarrhea. Although they are well known causes of diarrhea in children, rotavirus and adenovirus were identified in only 2 and 5% of adults respectively. In contrast human caliciviruses (HuCVs) and enterovirus were identified in 25 and 42% of adult cases respectively. Uncommon genotypes of HuCVs and recombinant forms (junction pol/l cap) as well as a significant number of sapovirus (30%) were identified. Further study is needed to clarify the role of enterovirus (echovirus) in the etiology of acute diarrhea in adults. No polivirus was identified. These new data from the Horn of Africa increase our knowledge about the epidemiology of acute infectious diarrhea that is a major public health problem and potential danger for travelers.

Caracterisation des virus agents potentiels des diarrhees chez l'adulte a Djibouti

Chez l'adulte; en zone tropicale; la part exacte des virus enteriques dans les diarrhees infectieuses aigues; demeure inconnue faute de moyens diagnostiques. Une etude multicentrique a permis de preciser la prevalence virale; chez des patients presentant des diarrhees aigues sporadiques a Djibouti. A partir d'un echantillon de 108 sujets; un large panel de virus enteriques a ete recherche par immunochromatographie; detection antigenique en ELISA immunocapture; RT-PCR; inoculation sur cellules permissives; analyse de sequences; et methodes indirectes en serologie. Les rotavirus et adenovirus agents principaux des gastroenterites chez l'enfant representent respectivement 2 et 5des cas. Les astrovirus; 5des cas. En revanche; les calicivirus humains (HuCVs) et enterovirus sont retrouves dans 25et 42des cas respectivement. Des genotypes inhabituels de HuCVs et des formes recombinantes (jonction pol / cap) ont ete mis en evidence; ainsi qu'un nombre relatif eleve de sapovirus (30). La participation des enterovirus (echovirus) dans l'etiologie des diarrhees sporadiques de l'adultemerite d'etre approfondie.Aucune souche de poliovirus n'a etemise en evidence. Ces nouvelles donnees concernant la Corne de l'Afrique renforcent nos connaissances epidemiologiques sur les diarrhees infectieuses aigues; probleme majeur de sante publique; et danger potentiel pour les voyageurs

Caracterisation des virus agents potentiels des diarrhees chez l'adulte a Djibouti

Chez l'adulte; en zone tropicale; la part exacte des virus enteriques dans les diarrhees infectieuses aigues; demeure inconnue faute de moyens diagnostiques. Une etude multicentrique a permis de preciser la prevalence virale; chez des patients presentant des diarrhees aigues sporadiques a Djibouti. A partir d'un echantillon de 108 sujets; un large panel de virus enteriques a ete recherche par immunochromatographie; detection antigenique en ELISA immunocapture; RT-PCR; inoculation sur cellules permissives; analyse de sequences; et methodes indirectes en serologie. Les rotavirus et adenovirus agents principaux des gastroenterites chez l'enfant representent respectivement 2 et 5des cas. Les astrovirus; 5des cas. En revanche; les calicivirus humains (HuCVs) et enterovirus sont retrouves dans 25 et 42des cas respectivement. Des genotypes inhabituels de HuCVs et des formes recombinantes (jonction pol / cap) ont ete mis en evidence; ainsi qu'un nombre relatif eleve de sapovirus (30). La participation des enterovirus (echovirus) dans l'etiologie des diarrhees sporadiques de l'adulte merite d'etre approfondie.Aucune souche de poliovirus n'a ete mise en evidence. Ces nouvelles donnees concernant la Corne de l'Afrique renforcent nos connaissances epidemiologiques sur les diarrhees infectieuses aigues; probleme majeur de sante publique; et danger potentiel pour les voyageurs

Translocation (X;1) associated with a nonpapillary carcinoma in a young woman: a new definition for an Xp11.2 RCC subtype.

We report a translocation (X;1)(p11.2;q21) associated with a nontubulopapillary renal cell carcinoma in a 23-year-old woman. To our knowledge this the first report of such an association. A review of the previously published cases of renal cell carcinoma with t(X;1) and its cytogenetic variants with Xp11.2 anomalies is included. The role of this karyotype abnormality as a clinical marker is discussed. The Xp11.2 abnormality could be a primary abnormality characterizing a particular type of RCC appearing in children and young adults of both sexes and in which the histological aspect is not specific.

Nucleoli, nucleolar chromosomes and ribosomal genes in the human spermatocyte.

The formation and development of nucleoli and their connections with the nucleolar chromosomes were studied in human spermatocytes using electron microscopy, silver staining of nucleolus organizer regions (NORs), high resolution autoradiography and in situ hybridization in order to localize rRNA genes and their transcription in the different stages of meiotic prophase I. At leptotene, new nucleoli were formed, consisting of a fibrillar centre surrounded by a cap of dense fibrillar component. Following [3H]uridine uptake, label was found only over the dense fibrillar component. In situ hybridization revealed rDNA mainly in the dense fibrillar component and in the chromatin. During zygotene, nucleoli increased in size. The fibrillar centre was connected with the secondary constriction region of the nucleolar bivalent and was partially surrounded by dense fibrillar component. This shell of dense fibrillar component merged into a fibrillo-granular mesh that extended away from the fibrillar centre. Autoradiography following [3H]uridine uptake again showed the label overlaying the dense fibrillar component and the proximal part of the fibrillo-granular strands. With in situ hybridization in both the light and electron microscope, signal was mainly found in the dense fibrillar component. A small quantity of label was observed in the peripheral region of the fibrillar centre and in the adjacent chromatin. From early to late pachytene segregation of nucleolar components occurred, with a reduction in the dense fibrillar component that formed a narrow rim around the fibrillar centre with small extensions along the granular component. [3H]uridine incorporation progressively decreased. In situ hybridization showed signal located mainly in the dense fibrillar component and in the chromatin corresponding to the condensed short arm of the nucleolar bivalent. Our results indicate that the majority of rDNA is located and transcribed in the dense fibrillar component; only a small amount is present in the peripheral part of the fibrillar centre and may be transcribed there. Moreover, from leptotene to zygotene, rDNA unravels from the nucleolar chromosome into the nucleolar dense fibrillar component. From zygotene to late pachytene a progressive return to the condensed acrocentric short arm is observed.

Sequential changes in the nucleoli of human spermatogonia with special reference to rDNA location and transcription.

The nucleoli of human spermatogonia were studied using electron microscopy, silver staining, radioautography and in situ hybridization. In all types of A spermatogonia, nucleoli were consistently located at the periphery of the nucleus and contained a single fibrillar center associated with the nuclear envelope. In B spermatogonia, nucleoli were centrally located in the nuclei and showed several fibrillar centers or were found to disintegrate. Nucleolar morphology was found to be a good, though not an unequivocal indicator of spermatogonial type. The observed changes in nucleolar morphology reflect the differentiation of spermatogonia: the nucleolar disintegration seen in B spermatogonia corresponds to a pre-leptotene cessation of rDNA transcription. In radioautographs following 3H-uridine uptake, the label was consistently found over the dense fibrillar component, except in the B spermatogonia with disintegrating nucleoli, where no uptake could be detected. In situ hybridization demonstrated that the distribution of rDNA did not correspond to the site of the fibrillar center but to the dense fibrillar component. Compared with radioautographs, this finding clearly established that transcribed units of rDNA were located in the dense fibrillar component. Silver staining was strongly positive in fibrillar centers and in the dense fibrillar component. In Ap spermatogonia the silver deposit was often localized at the edge of the fibrillar threads. The relationships between silver-stained proteins and transcribed and nontranscribed portions of ribosomal genes are reevaluated.

Chromosomal constitution of nucleolus-associated chromatin in man.

Use of specific stains permits analysis of the frequency of nucleolus-associated heterochromatin in chromosomes 1 and 9 from human fibroblasts. In 81 per cent of interphase nuclei the heterochromatic segment of both No. 1 chromosomes is associated with the nucleolus, while in 19 per cent only one heterochromatic segment shows such an association with the other occupying a random position in the nucleoplasm. The nucleolar association of chromosome 9 heterochromatin is less constant: in 42.3 per cent of the nuclei both segments are associated with the nucleolus, in 39 per cent of the nuclei only one heterochromatic segment presents such an association, and in 18.7 per cent neither of the two heterochromatic segments is in nucleolar association. In 6 per cent of the cells, one or two chromosome 9 heterochromatic segments are in contact with the nuclear membrane. In situ hybridization using tritium-labeled 28S and 18S RNA shows that in the interphase nucleus the acrocentric short arms, carriers of ribosomal cistrons, are associated with the nucleolus. These observations demonstrate the complexity of the nucleolus-associated chromatin which, in addition to segments of chromosomes 1, 9, 13, 14, 15, 21, 22, may include the Y chromosome. They also confirm that the nucleolus constitutes one of the orientation points determining the relative localization of chromosomes in the interphase nucleus.