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Biomedical subjects

M Huerre

Publications and source records attributed to M Huerre.

At least 91 records · Page 5Linked to original sources

Role of interleukin-1 in the pathogenesis of experimental shigellosis.

The effect of human recombinant interleukin-1 receptor antagonist on intestinal inflammation, tissue destruction, and bacterial invasion during experimental shigellosis caused by Shigella flexneri was studied in the rabbit-ligated loop infection model. Intravenous infusion of the inhibitor at a dose of 2 mg/kg per h, was initiated 30 min before intestinal loops were ligated and infected, and continued during the 8-h period of infection. The animals treated with IL-1 receptor antagonist showed a striking decrease in inflammation, destruction, and bacterial invasion of their tissues, both at the level of the villous intestine and Peyer's patches. This is conclusive evidence that interleukin-1 plays a critical role in the pathogenesis of shigellosis. This proinflammatory cytokine is here proposed as a major trigger of the inflammatory reaction which is characteristic of this invasive disease of the intestine, due to the particular interaction existing between S. flexneri and macrophages.

Animals↗

[Colonic Histoplasma capsulatum pseudotumor in AIDS. Morphological and immunohistochemical diagnosis of an isolated lesion].

The authors report a case of a 35-year-old man with acquired immunodeficiency syndrome (AIDS) and a left colonic mass with Histoplasma capsulatum (H. capsulatum). The look-up performed looking for disseminated infection was negative. In the absence of positive cultures, the diagnosis was determined morphologically based on the presence of yeast observed by light and electron microscopy. The diagnosis was also verified by positive immunofluorescence using specific anti-Histoplasma antibodies. Gastrointestinal histoplasmosis is a frequent complication of AIDS, particularly in some endemic areas of America. Association with a disseminated mycotic infection is then common. Histoplasmosis is less frequently diagnosed in Europe and isolated involvement of the colon is exceptional. When the mycological study is not performed or is negative, only morphological and immunohistochemical methods are able to establish the diagnosis and eliminate other mycotic diseases occurring during AIDS.

AIDS-Related Opportunistic Infections↗

[A case of dirofilariasis of the scrotum of probable origin in Languedoc].

Adult Dirofilaria (Nochtiella) repens in scrotal cavity is a rare localisation (likewise in others localisations). This report deals with a case occurred in Languedoc (about 50 cases of subcutaneous dirofilariasis were described in France). The localisation in scrotal cavity occurred probably after migration of adult female in subcutaneous tissue.

Adult↗

[Laryngeal cytomegalovirus infection after heart transplantation].

The authors report a case of laryngeal ulceration due to cytomegalovirus occurring in a 60-year-old man one month after heart transplant. The recipient was initially CMV seronegative and the donor positive. No preventive treatment was administered. One month after the transplantation, search for CMV in blood and urine became positive and a seroconversion occurred. Laryngeal biopsy showed an inflammatory reaction with cells containing atypical inclusions and positivities with anti-CMV antibody. Usual intranuclear eosinophilic inclusions of classic CMV infection were absent. The authors stress the unusual site of the lesions in this primo-infection and the atypical aspect of the inclusions. Such atypical inclusions which have already been reported in immunosuppressed people make the diagnosis more difficult.

Cytomegalovirus Infections↗

Acute inflammation causes epithelial invasion and mucosal destruction in experimental shigellosis.

The gram-negative pathogen Shigella flexneri causes bacillary dysentery, an invasive disease of the human colonic mucosa. A major characteristic of the infectious process is the occurrence of an acute inflammatory reaction of mucosal tissues which is generally consequence of primary invasion and destruction of colonic epithelial cells by the pathogen. Confirming in vitro demonstration that S. flexneri is unable to invade the apical pole of colonic cells and that polymorphonuclear (PMN) cells may assist them in reaching the basal side of epithelial cells where they can invade, we have provided here in vivo evidence that S. flexneri enters the epithelial barrier essentially through the dome of lymphoid follicles at the early stage of infection and that subsequent invasion and destruction of the epithelium is primarily due to immigration of leukocytes, particularly PMN that destroy cohesion of the epithelial barrier. These conclusions are based on experiments carried out in infected rabbit ligated intestinal loops, with some animals treated by an anti-CD18 monoclonal antibody that blocked immigration of leukocytes into infected tissues.

Acute Disease↗

Cloning and disruption of the gene encoding an extracellular metalloprotease of Aspergillus fumigatus.

Aspergillus fumigatus secretes a serine alkaline protease (ALP) and a metalloprotease (MEP) when the fungus is cultivated in the presence of collagen as sole nitrogen and carbon source. The gene encoding ALP was isolated and characterized previously. We report here the cloning and the sequencing of the gene encoding MEP. Genomic and cDNA clones were isolated from A. fumigatus libraries using synthetic oligonucleotides as probes. Stretches of the deduced amino acid sequence were found to be in agreement with the N-terminal amino acid sequence of MEP and with internal peptide sequences. The amino acid sequence of the enzyme contains a putative active-site sequence HEYTH homologous to the active site of other bacterial and eukaryotic zinc metalloproteases. Sequence analysis reveals that MEP has a pre-proregion consisting of 245 amino acid residues preceding the 388 amino acid residues of the mature region (molecular mass of 42 kDa). An alp mep mutant, deficient in proteolytic activity at neutral pH in vitro, was constructed and tested for pathogenicity in a murine model. No difference in pathogenicity was observed between the wild-type strain and the alp mep double mutant, suggesting that ALP and MEP are not essential for the invasion of the lung tissues by A. fumigatus.

Amino Acid Sequence↗

Recombinant antigens prepared from the urease subunits of Helicobacter spp.: evidence of protection in a mouse model of gastric infection.

Urease is an important virulence factor for gastric Helicobacter spp. To elucidate the efficacy of individual urease subunits to act as mucosal immunogens, the genes encoding the respective urease subunits (UreA and UreB) of Helicobacter pylori and Helicobacter felis were cloned in an expression vector (pMAL) and expressed in Escherichia coli cells as translational fusion proteins. The recombinant UreA and UreB proteins were purified by affinity and anion-exchange chromatography techniques and had predicted molecular masses of approximately 68 and 103 kDa, respectively. Western blotting (immunoblotting) studies indicated that the urease components of the fusion proteins were strongly immunogenic and were specifically recognized by polyclonal rabbit anti-Helicobacter sp. sera. The fusion proteins (50 micrograms) were used, in combination with a mucosal adjuvant (cholera toxin), to orogastrically immunize mice against H. felis infection. Gastric tissues from H. felis-challenged mice were assessed by the biopsy urease test and by histology. In mice immunized with recombinant H. felis UreB, 60% of animals (n = 7) were histologically negative for H. felis bacteria after challenge at 17 weeks. This compared with 25% (n = 8) for mice immunized with the heterologous H. pylori UreB antigen. Neither the homologous nor the heterologous UreA subunit elicited protective responses against H. felis infection in mice. The study demonstrated that a recombinant subunit antigen could induce an immunoprotective response against gastric Helicobacter infection.

Animals↗

[Hepatic hydatidosis in Madagascar: a case of autochthonous origin].

Hydatid disease, due to the larval stage of Echinococcus granulosus, is described for the second time at liver level, in Madagascar. Even with a low level of endemic animal disease and an uncontrolled population of stray dogs, the human parasitosis is very rare in Madagascar. It is interesting to note that, since a hundred of years, the epidemiological status of this Zoonosis has not really changed in the great island.

Adult↗

[Entomophthoromycoses in Madagascar (three cases)].

The authors present three new cases of Entomophthoromycosis observed in Madagascar: Two cases of subcutaneous entomophthoromycosis without isolation of germ. An immunofluorescence technique showed the Basidiobolus ranarum to be the real cause. One case of rhinoentomophthoromycosis with isolation of Conidiobolus coronatus (first isolation in Madagascar).

Adult↗

[Adult T-cell leukemia associated with HTLV-1 in a HIV-2 seropositive African].

INTRODUCTION: The aim of this report is to describe an HIV-2 seropositive patient from Mali who had adult-T cell Leukaemia/Lymphoma associated with HTLV-I infection. CASE REPORT: The patient presented with erythroderma and foliate lymphocyte leukaemia. Skin biopsy showed an epidermotropic lymphoma. Tumoural cells expressed a mature T-cell phenotype CD4+/CD25+. High anti-HTLV-I titers and the evidence of monoclonal integration of HTLV-I provirus within circulating lymphoid cells led to the confirmation of HTLV-I as the causal agent in tumour cell transformation. HIV-2 serology was positive. DISCUSSION: Sub-Saharan Africa is a vast reservoir of HTLV-I virus with at least 5 million infected persons. Cases of adult-T cell Leukaemia/Lymphoma in Africans are exceptional. Lack of sufficient knowledge of the disease could partially explain this discrepancy. The main differential diagnosis in dermatology is primary T-cell lymphomas of the skin, particularly mycosis fungoides and Sézary syndrome.

Adult↗

[Leprosy in New Caledonia from 1983 to 1992. Histopathological and epidemiological data].

New Caledonia is a South Pacific Island inhabited by more than 170,000 people: most of them are melanesians or europeans. Multidrug therapy for Hansen disease has been employed since 1983; so we made an epidemiologic and histopathologic study of the new cases diagnosed for 10 years, from 1983 to 1992. Local (clinical, histological, microbiological and immunological) means of diagnosis are described. In New Caledonia, the endemic level is lower than in the small neighbouring Pacific islands but there is still a native reservoir of Mycobacterium leprae with 40% multibacillary types. Nearly half of the new cases are less than 25 years old. They are often male melanesians. The diagnosis of indeterminate forms is debated when there is no acid-fast bacillus. Border-line forms are rare. Tuberculoid leprosy poses many differential diagnosis problems. Despite available multidrug therapy, one cannot yet consider that the incidence is decreasing significantly.

Adult↗

[Carcinosarcoma arising in eccrine spiradenoma. A morphologic and immunohistochemical study].

Malignant change in a benign eccrine spiradenoma is a rare but definite phenomenon. Since it was first reported by Dabska, 23 cases have been reported. All cases present recent changes in a long standing cutaneous nodule which, when excised and examined microscopically, disclosed carcinoma associated and arising from benign eccrine spiradenoma. Eight patients died of disseminated tumours. Histologic features, in three fatal cases, showed carcinosarcoma and particularly osteosarcoma in one case. A further fatal case of carcinosarcoma arising in spiradenoma, is reported in a Melanesian man aged 38, who died after 8 months. Histologic examination showed squamous cell carcinoma associated with osteosarcoma in the recurrence.

Adenoma, Sweat Gland↗

[Dengue epidemic in New Caledonia (1989). Environmental factors and prevention].

An extensive dengue epidemic was reported in New Caledonia en 1989. Environmental factors (temperature and rainfalls) directly controlled the mosquitos population at the end of 1988. The introduction of a new dengue virus, transmitted by Aedes aegypti, was responsible for an epidemic that occurred in January-April 1989 and lasted until July 1989. The estimated number of cases was 25,000 and the attack rate was close to 120 per thousand inhabitants for a six month-period. The epidemic involved mainly the adult population in 84% of cases and 6-8% of patients was admitted in hospital with thrombopenia, leucopenia, minor haemorrhages in 2/3 of cases and 12 patients died with severe hemorrhagic disease or shock syndrome; initial serological results from suspected cases were positive against dengue by haemaglutination inhibition. Two dengue viruses were involved (dengue 1 and dengue 3) but dengue 3 was by far the most common. Ultra-low volume aerosols of diluted insecticide (decamethrine K'Othrine, Roussel) from road vehicles and aircraft was used from February to May to kill the adult mosquitoes (adulticiding). The efficacy dependent on the interaction of the insecticide and the flying mosquitoes is relative and debated but played probably a major role on the transmission, though the reduction of breeding sites was primarily uncovered. Since the epidemic, only sporadic cases were observed in 1991 and 1992.

Animals↗

[Human protothecosis and environment].

Protothecosis are uncommon infections caused by Prototheca, considered to be achlorophylous algae. Nearly 80 human cases are reported in the literature since the first case described by Davies and Wakelin in 1964 in Sierra Leone (11). The disease have been identified in Europe, Asia (Japan, Thailand, China), Oceania and in the United States with 40 cases, particularly in the Southeast. Clinically, three clinical manifestations can be observed: 1) cutaneous lesions: papules, plaques or eczematoid, papulo-nodular areas of the extremities, 2) olecranon bursitis which occurred in 25% of cases, 3) systemic protothecosis. An immunosuppressive factor local or general can be found in half of the cases and the first description of algal meningitis was reported in a patient with AIDS in association with Cryptococcus neoformans. Because the disease is clinically not suspected, the diagnosis is often provided by histology showing a dermic granuloma with endospores. The characteristic feature of protothecosis in tissues is the presence of specific mature sporangia of Prototheca wickerhamii with the pattern of morula. The organism was PAS, Grocott and mucicarmin positive. The ecology was studied by Clark (7), Pidoux (23), Pore (25) and Sudman (27). Prototheca are ubiquitous inhabitants of sewages and are found in slime flux and animal wastes contaminating different aquatic systems. The transmission generally occurred by traumatic inoculation. Prototheca are also found in the digestive system of man and animals without never invasion of the epithelium and mucosae in experimental models. The pathogenicity and virulence are moderate and they are considered as rare opportunistic agents.

Animals↗

[Cutaneous malignant melanoma in New Caledonia (South Pacific) 1973-1991. A study of 97 cases].

The Cancer Registries have been operational in the South Pacific since 1958 (Papua New Guinea), Fiji (1965) and New Caledonia (1977) and complete cancer incidence rates are available, based on histologic data. We studied 97 melanomas, histologically confirmed, which were diagnosed in New Caledonia from 1973 to 1991. New Caledonia is located in the same latitude as Queensland in Australia, known for having the highest incidence of melanoma in the world. Standardised incidence rates (world population) were 9.82 and 7.65/100,000/year for European males and females, compared to 1.65 and 1.05 for Melanesian and Polynesian males and females. The European population is exposed and Melanesians/Polynesians are relatively protected as are black Americans or Africans. The mixed populations are protected, but no study is available as to the exact proportion of mixed people (20%?) in the entire population. For Europeans, among males, the main areas in which melanomas occur are the trunk (45%) the arm (13%) and the leg (13%). Among females, the main areas are the leg (27%), the trunk (20%) and the head (18%). Screening for melanoma has been more effective in the last 6 years, a period in which we diagnosed half the total cases and generally at earlier stages. Prognosis was poor for this period (1973-1991): the five year survival rates were 64% +/- 8%, not as good as in Europe or Australia, but these lesions were diagnosed between 1973 and 1985 and were generally more invasive. A better prognosis will probably be observed in a few years, and another evaluation of melanoma screening should be made in the future as well the study of precursors and early lesions.

Adult↗

[Malignant teratoid medulloepithelioma of the ciliary body. Apropos of a case and review of the literature].

A case of ocular medulloepithelioma is reported and the authors review the literature concerning these rare tumors. This report concerns a ten-month-old girl in whom ophthalmic examination showed a large tumor arising in the ciliary body with such rapid progression that enucleation was necessary. Pathological findings were compatible with a malignant teratoid medulloepithelioma. According to preceding descriptions, slit lamp examination and ultrasonography are the best approach to the diagnosis. Medulloepithelioma is a tumor composed of poorly differentiated neuroepithelial cells and the predominant histological feature is a net-like pattern. Teratoid forms contain cartilage or brain tissue or bundles of skeletal muscle. The main criterion for malignancy is the presence of neuroblastic cells. Local excision is sufficient when the tumor is mall, otherwise enucleation or even exenteration may be necessary. The prognosis is generally good even when the tumor presents malignant features on pathological examination, provided treatment is instituted rapidly.

Ciliary Body↗