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H Zeller

Publications and source records attributed to H Zeller.

At least 37 records · Page 2Linked to original sources
PubMed1999

In situ detection of tissue factor within the coronary intima in rat cardiac allograft vasculopathy.

Cardiac allograft vasculopathy is a major cause of morbidity and mortality of cardiac transplant recipients. The underlying cause of this disease remains unclear. Histological studies have implicated accelerated hemostasis and intravascular fibrin deposition in its pathogenesis. In the present study a defined model of this disease in the rat was used to elucidate the implication of tissue factor in the production of the hypercoagulable state observed in cardiac allograft vessels. Tissue factor protein and mRNA expression were studied in rat heart allografts developing allograft vasculopathy resembling human disease. Immunohistochemistry demonstrated tissue-factor-positive cells present in the allograft coronary intima and adventitia. Significant staining for tissue factor was detected in the endothelium lining coronary lesions in cardiac allografts and in interstitial mononuclear cells, respectively. Both transplant coronary endothelial cells and mononuclear cells contained tissue factor mRNA as indicated by oligo-cell reverse transcription polymerase chain reaction after laser-assisted cell picking. In contrast, tissue factor mRNA and protein were not or negligibly detectable within the coronary intima of nontransplanted control hearts. Thus, the present study clearly demonstrates that aberrant tissue factor expression occurs within the coronary intima after cardiac transplantation. Tissue factor, activating downstream coagulation mechanisms, may account for the intravascular clotting abnormalities observed in cardiac allografts and may represent a key factor in transplant atherogenesis.

Animals↗
PubMed1999

[Democratic Republic of the Congo: between civil war and the Marburg virus. International Committee of Technical and Scientific Coordination of the Durba Epidemic].

Because the epidemiology of viral hemorrhagic fever is unclear, each outbreak is a spectacular event that focuses the attention of the international scientific community. When an epidemic of Marburg virus disease occurred in the Durba region located in the northeastern part of the People's Republic of the Congo, 23 scientists were sent from 12 different countries. Sixty of the 73 people infected died. The first case was observed in December 1998 and the last in May 1999. Because of political unrest in the country, the outbreak was not reported immediately and most data was collected by observers retrospectively. However Marburg virus infection was confirmed in 5 of 16 patients in whom testing was performed and person-to-person transmission was demonstrated. Thus the Durba outbreak was the first epidemic of Marburg virus disease not involving laboratory contamination. Initial epidemiologic findings suggest that the first cases involved miners who were probably infected by contact with an animal reservoir such as bats. Further studies to determine seroprevalence in the general population and virologic testing on animals captured in the zone should provide answers to these questions.

Adolescent↗
PubMed1998

[Epidemiological surveillance of grippe and dengue. Réunion, 1996].

The local Welfare and Health Authorities together with the country council of Reunion Island set up a medical supervision network for influenza and dengue fever in March 1996. Influenza of which the spreading over the island has never been well-researched is anticipated by a vaccination campaign organised in an empirical way after a model from the mother country (France). Dengue fever of which one of the vectors is omnipresent on the island ranged in an epidemic way in 1978. The aim of this network based on watching doctors, the laboratories of the island as well as the Pasteur Institute of Madagascar, is to adapt the prevention (Flu) and alert the Health Authorities in case of epidemic (Dengue). The article shows the results of 1996 observation and touches on the future of this type of supervision in a tropical environment.

Dengue↗
PubMed1997

[Prevalence of hepatitis C virus infection in the general population of Madagascar].

The achievement of a sera collection representative for the general population > or = 1 year in 1994 allowed the assessment of the seroprevalence of Hepatitis C virus infection (HCV) in Antananarivo and Toamasina provinces which represent 45% of the total population of Madagascar. The overall sero-prevalence was 1.2% among the 921 tested sera. The prevalence was not significantly different according to sex, but it increased according to the age. The absence of positive children was an argument in consideration of the low importance of mother-to-infant transmission in the epidemiology of HCV. A significant relationship was observed with past history of blood transfusion. This point is a well established idea that reminds the interest of the detection of positive individuals for anti-HCV antibodies. The seroprevalence observed in our study could be considered as moderate. It is close to the values recorded in Europe or in Japan, and much lower than those observed in Equatorial Africa.

Adolescent↗
PubMed1995

[AIDS and tuberculosis: the situation in Madagascar].

Because of the known epidemiological links between tuberculosis and HIV infection in developing countries, a systematic study of HIV infection prevalence among tuberculous patients has been conducted since 1989 in some centres of the capital and extended to other towns in 1992. HIV infection prevalence is still low (<200/100,000) with tuberculous patients. This result must incite to continue the surveillance of the ineluctable growth of HIV prevalence and to strengthen the tuberculosis Program in anticipation of subsequent problems.

AIDS-Related Opportunistic Infections↗
PubMed1994

Dengue 2 outbreak in southeastern Senegal during 1990: virus isolations from mosquitoes (Diptera: Culicidae).

During 1990, Dengue-2 (DEN-2) virus was isolated for the first time from mosquitoes (Aedes furcifer, six isolates; Ae. taylori, six isolates; Ae. luteocephalus, seven isolates) collected during an epidemic in which DEN-2 virus also was isolated from humans. Numerous isolations have been made previously from mosquitoes in the absence of human infection. In Senegal, DEN-2 virus appears to be maintained in an enzootic cycle and, therefore, plays an expanding role in human disease and increases the need for effective surveillance in mosquito populations.

Aedes↗
PubMed1994

[Decrease of natural immunity against Rift Valley fever in domestic ruminants of the Senegal River basin after the epizootic outbreak of 1987].

A domestic ruminants serosurvey of Rift valley fever (RVF) neutralizing antibodies has been carried out during three years after the 1987 epidemic in the Senegal River Basin. Authors present results from the 1990 serosurvey that are matched with the preview surveys. Out of 1,225 ongulate tested, 17.2% had RVF virus antibodies. There is a global decrease in the herds immunity since the epizootic manifestation associated with the 1987 epidemic. Significant differences in seroprevalence are observed from the delta (28.5%) to the lower (17.9%) and middle valley (6.1%) of the Senegal river. Cattle are more likely to be with an higher seroprevalence than goat and sheep.

Animals↗
PubMed1993

Direct sequencing of genomic cDNA fragments amplified by the polymerase chain reaction for molecular epidemiology of dengue-2 viruses.

A nucleotide fragment encoding amino acids 29 to 94 in the E-protein of 28 dengue-2 isolates of diverse geographic and host origins was examined by direct sequencing of a polymerase chain reaction (PCR)-amplified product, and compared to six previously published sequences. Nucleotide divergence ranged from 0 to 19.8% corresponding to a maximum of 9% divergence in the amino acid sequence. Taking a divergence of 6% between the nucleotide sequence as a cut off for genotype classification, six groups have been established. Southeast Asian and the Jamaican 1983 genotypes show a high rate of similarity (> 95.2%). Our results suggest that virus of this group is now circulating as the dominant topotype in Brazil (1990) and in French Guyana (1986-1991). African strains fall into two groups, one endemic group (1970-1990) and one epidemic group (1986-1987). The three other groups correspond to viruses from Sri Lanka (1982) and the Seychelles (1977), from Puerto Rico (1973) and from Tahiti (1975). Our approach appears to be valuable characterizing dengue isolates, easily and rapidly.

Aedes↗
PubMed1993

[Surveillance of the circulation of arbovirus of medical interest in the region of eastern Senegal].

A study about the circulation of arboviruses of medical interest in southeastern Senegal was conducted from 1988 to 1991, during and around the periods of transmission. Specific IgM antibodies were detected by ELISA test in human sera, as a sign of a recent infection within 2 to 5 months. The comparison of the serological IgM results from human surveys in different villages, and the isolations of arboviruses from mosquitoes during the same period of time permitted a rapid and global evaluation of the circulation of these viruses. A low level of yellow fever virus activity was detected both in humans and mosquitoes in 1988 to 1990. A dengue 2 epizootic occurred in 1989-1990. Dengue 2 virus was isolated from humans and mosquitoes in 1990. Some dengue 2 outbreak may occur in the upcoming years. A Zika virus epizootic outbreak was observed each year. A human strain was isolated in 1990. The other flaviviruses (West-Nile, Kedougou, Wesselsbron), Chikungunya virus, Rift Valley Fever virus and Crimean-Congo Hemorrhagic Fever virus did not seem to present a major public health concern in southeastern Senegal.

Animals↗
PubMed1993

[Yellow fever epidemic in the extreme North of Cameroon in 1990: first yellow fever virus isolation in Cameroon].

Some two years ago, suspicious cases of yellow fever (YF) were reported in northern Cameroon. A deadly epidemic broke out during the second half of the rainy season (from 15 September to 22 December 1990) with 180 known cases, of which 125 died. The real figures could have been between 5000 and 20,000 cases with between 500 and 1000 deaths. The affected area was within the yellow fever belt, which is situated around latitude 11 degrees North and 14 degrees East. In this mountainous area (altitude, about 800 m) the rural inhabitants are scattered, with a high density of 200,000 people per 1000 km2. Investigations began at the start of the dry season and a strain of yellow fever virus was isolated for the first time in Cameroon. A study of 107 serum samples (23 families in 11 villages) was carried out by immunofluorescence and ELISA, which showed 20% IgM carriers for yellow fever virus and nothing for the three other flaviviruses, although these were largely present; there were up to 98% crossed reactions in IgG with dengue 2 and West Nile strains. The under-10 age group represented 63% of the IgM carriers. An entomological study was carried out at the same time. It permitted the capture of Aedes aegypti, A. furcifer, A. luteocephalus and the identification of numerous potential larval sites, at times still in the productive phase of A. aegypti which is considered to be the principal vector.(ABSTRACT TRUNCATED AT 250 WORDS)

Aedes↗
PubMed1990

Cloning and sequence analyses of cDNAs for interferon- and virus-induced human Mx proteins reveal that they contain putative guanine nucleotide-binding sites: functional study of the corresponding gene promoter.

The human protein p78 is induced and accumulated in cells treated with type I interferon or with some viruses. It is the human homolog of the mouse Mx protein involved in resistance to influenza virus. A full-length cDNA clone encoding the human p78 protein was cloned and sequenced. It contained an open reading frame of 662 amino acids, corresponding to a polypeptide with a predicted molecular weight of 75,500, in good agreement with the Mr of 78,000 determined on sodium dodecyl sulfate gels for the purified natural p78 protein. The cloned gene was expressed in vitro and corresponded in size, pI, antigenic determinant(s), and NH2 terminus sequence to the natural p78 protein. A second cDNA was cloned which encoded a 633-amino-acid protein sharing 63% homology with human p78. This p78-related protein was translated in reticulocyte lysates where it shared an antigenic determinant(s) with p78. A putative 5' regulatory region of 83 base pairs contained within the gene promoter region upstream of the presumed p78 mRNA cap site conferred human alpha interferon (IFN-alpha) inducibility to the cat reporter gene. The p78 protein accumulated to high levels in cells treated with IFN-alpha. In contrast, the p78-related protein was not expressed at detectable levels. The rate of decay of p78 levels in diploid cells after a 24-h treatment with IFN-alpha was much slower than the rate of decay of the antiviral state against influenza A virus and vesicular stomatitis virus, suggesting that the p78 protein is probably not involved in an antiviral mechanism. Furthermore, we showed that these proteins, as well as the homologous mouse Mx protein, possess three consensus elements in proper spacing, characteristic of GTP-binding proteins.

Amino Acid Sequence↗
PubMed1989

Regulation of the interferon-inducible IFI-78K gene, the human equivalent of the murine Mx gene, by interferons, double-stranded RNA, certain cytokines, and viruses.

The interferon-inducible gene (IFI-78K gene) that codes for a human protein, p78, of 78,000 Mr is the equivalent of the mouse Mx gene encoding Mx protein. The IFI-78K gene is located on chromosome 21 together with the alpha/beta interferon (IFN-alpha/beta) receptor. The p78 protein is important since it may be involved in resistance to influenza viruses. The regulation of the IFI-78K gene was studied in human diploid cells by using a cDNA probe to p78 mRNA and specific monoclonal antibodies to p78 protein. The IFI-78K gene, a normally quiescent gene, is transcriptionally regulated by IFN-alpha, and its induction does not require protein synthesis. The rate of transcription measured in a run-on assay increased rapidly but transiently. The level of p78 mRNA increased up to 8 h, declining slowly afterwards. The p78 protein, undetectable in untreated cells, accumulated up to 16 h, and its amount remained stable for at least 36 h after the addition of IFN-alpha. Cytokines such as tumor necrosis factor, interleukin-1 alpha, and interleukin-1 beta activated the IFI-78K gene at concentrations comparable to that of IFN-alpha. However, gene activation by these cytokines required protein synthesis. Poly(rI)-poly(rC) induced the IFI-78K gene directly at the transcriptional level without requirement for protein synthesis. Newcastle disease virus, influenza virus, and to a lesser extent vesicular stomatitis virus also induced the IFI-78K gene in the absence of any protein synthesis. Induction of transcription by viruses was markedly enhanced by pretreatment of cells with IFN-gamma (which by itself is a poor inducer of the IFI-78K gene), resulting in accumulation of p78 protein during the course of infection; this suggests that IFN-gamma programs cells to full antiviral activity upon virus infection.

Blotting, Northern↗
PubMed1989

Blood glucose measurement by infrared spectroscopy.

For the development of an implantable artificial endocrine pancreas, a sensor for blood glucose measurement is needed providing a long-term stability. This goal can be achieved by the application of infrared spectroscopy which, unlike electrochemical sensors, responds directly to the glucose molecule. An investigation under physiological conditions revealed five glucose absorption bands in the near and middle infrared range. These are 1040, 1085, 1109, 1160 and 1365 cm-1. Only the 1040 cm-1 frequency coincides with none of the other infrared-active blood substances like proteins, lipids and urea. Nevertheless, the other absorption bands too, especially the 1109 cm-1 frequency, can be used for blood glucose measurement, if the superimposed absorptions are compensated. Methods for the compensation have been found. Technically feasible embodiments of an infrared glucose sensor are described.

Blood Glucose↗