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Biomedical subjects

I Tellez

Publications and source records attributed to I Tellez.

11 recordsLinked to original sources

Sporotrichosis in Peru: description of an area of hyperendemicity.

Sporotrichosis is a sporadic and rare mycotic infection in most of the developed world. In many parts of the developing world, sporotrichosis is much more commonly recognized, but epidemiological data are generally lacking from these regions. We report epidemiological, clinical, and treatment data from 238 cases of culture-proven sporotrichosis occurring in a relatively remote area of the south central highlands of Peru that were retrospectively collected during 1995-1997. Most cases (60%) occurred in children aged </=14 years, and the most commonly affected anatomic site was the face. Disease was clinically confined to the skin and subcutaneous tissue in all patients. The incidence of sporotrichosis in this region ranged from 48 to 60 cases per 100,000 persons and was highest among children aged 7-14 years, approaching 1 case per 1000 persons. Sporotrichosis is a significant mycosis in the rural highlands of Peru, with an incidence exceeding those of other invasive mycoses in individuals without human immunodeficiency virus infection.

Adolescent↗

Citrobacter diversus endocarditis.

Citrobacter species are motile Gram-negative bacilli that cause disease in humans, such as urinary tract infection, pneumonia, superficial and deep wound infections, gastroenteritis, meningitis, bacteremia, and rarely endocarditis. In those cases of endocarditis, intravenous drug use has been associated with Citrobacter species. Gram-negative organisms are present in less than 10% of cases of endocarditis in intravenous drug users. We present a case of tricuspid valve endocarditis in an intravenous drug user caused by Citrobacter diversus alone.

Citrobacter↗

A significant number of human immunodeficiency virus epitope-specific cytotoxic T lymphocytes detected by tetramer binding do not produce gamma interferon.

Despite the seemingly important role of cytotoxic T-lymphocyte (CTL) responses in human immunodeficiency virus (HIV) disease pathogenesis, their measurement has relied on a variety of different techniques. We utilized three separate methodologies for the detection of CTLs in a cohort of HIV-infected individuals who were also human leukocyte antigen A2 (HLA-A2) positive. Among the different CTL assays, a correlation was seen only when the Gag epitope-specific HLA A*0201-restricted tetramer assay was compared with the ELISPOT assay performed after stimulation with the Gag epitope; however, this correlation was of borderline statistical significance. On average, the tetramer reagent detected a 10-fold-higher number of cells than were seen to produce gamma interferon by the ELISPOT assay. The implications of this CTL assay comparison and the possibility of phenotypic differences in HIV-specific CD8(+) T lymphocytes are discussed.

Biopolymers↗

Extracardiac vascular and neural lesions in the toxic oil syndrome.

The toxic oil syndrome is a multisystemic disease caused by the ingestion of adulterated rapeseed oil. The basic lesion is a peculiar vasculitis that affects mainly the intima, showing the features of an endovasculitis. Vessels of every type and size are involved, affecting practically every organ. The vascular lesions begins with endothelial damage that varies from cellular swelling to cellular necrosis. It then progresses by mixed cellular inflammatory infiltration of the intima and, in some cases, of the media and adventitia. In some cases the infiltrate is rich in eosinophils and a few show foamy histiocytes. Proliferation of myointimal cells and in advanced stages fibroblastic proliferation causes narrowing or obliteration of the vascular lumen. Thromboembolic complications perpetuate the vascular lesion and compound the ischemia and parenchymal atrophy of several organs. The peripheral nerve lesions begin with an inflammatory neuropathy with lymphocytic perineuritis and progress to perineural fibrosis with secondary axonal degeneration. Skeletal muscle lesions exhibit an interstitial inflammatory myopathy at first, followed by a neurogenic muscular atrophy. A direct effect of unidentified toxic substances, possibly free radicals, may cause the endothelial lesion. Other factors, such as immunopathologic mechanisms of delayed hypersensitivity, may contribute to the progression of the vascular lesions.

Brassica↗

Pathology of a new toxic syndrome caused by ingestion of adulterated oil in Spain.

The Toxic Syndrome (TS) caused by ingestion of adulterated rapeseed oil in Spain is a new disease of multisystemic character whose aetiology and pathogenesis remains unknown. The most prominent pathological feature is a peculiar non-necrotizing vasculitis, that affects mainly the intima and involves vessels of every type and size in practically every organ. The TS begins with an acute clinical picture with pleuropneumopathy, fever, headaches, exanthems and eosinophilia. In these early clinical phases the main pathological findings were observed in the lungs and consisted of intense pulmonary interstitial oedema with scanty inflammatory mononuclear infiltrates. Ultrastructural study revealed hydropic degeneration of pneumocytes types I and II with desquamation of type I. The patients in this phase died of respiratory failure, later deaths were due to thromboembolic complications. Later still the patients developed a neuromuscular syndrome, sclerodermiform skin lesions and severe weight loss and died predominantly of infectious complications and respiratory failure. The anatomopathological picture in the peripheral nerves was that of inflammatory neuropathy with a lymphocytic perineuritis that led to perineural fibrosis with secondary axonal degeneration. The muscle presented an interstitial inflammatory myopathy at first followed by a neurogenic muscular atrophy. The skin lesions in the late phases consisted in dermal or dermal and subdermal fibrosclerosis, with vasculitis of the small arteries in the lower dermis. The salivary glands and pancreas showed vasculitis and interstitial inflammation which progressed to interstitial fibrosis and parenchymal atrophy.

Adolescent↗

Neurotoxicity of sodium cyanate. New pathological and ultrastructural observations in Maccaca nemestrina.

The effects of sodium cyanate (NaNCO) on the nervous system of Maccaca nemestrina were studied at 2, 4, and 6 months of administration of the drug. The two groups injected with daily doses of 35 and 25 mg/kg/day of Na-cyanate developed a predominantly demyelinating lesion in the pyramidal tracts of the spinal cord. No neuronal changes were observed in the motor cortex, basal ganglia, midbrain, medulla or anterior horn cells of the spinal cord. There was no evidence of peripheral neuropathy. A comparison between the cyanate induced neuropathy in the rat and in the primate was drawn. Ultrastructurally, both species developed a demyelinating process of central or peripheral myelin characterized by vacuolation of the myelin sheath, removal of myelin debris by macrophages and re-myelination. There was little evidence of axoplasmic damage except for an occasional distended fiber containing abundant dense bodies and whorls of neurofilaments. Oligodendrocytes and Schwann cells were electron microscopically intact and participated actively in remyelination. Maccacas maintained at 15 mg/day and sham animals remained normal clinically and anatomically. The predominantly myelinotoxic effect of cyanate is similar to that produced by other myelinotoxic agents and is attributed to a selective modification of myelin proteins by carbamylation.

Animals↗

Sickling rates of human AS red cells infected in vitro with Plasmodium falciparum malaria.

The kinetics of sickling of malaria-infected red cells from humans with sickle cell trait were studied in vitro in an attempt to obtain direct experimental evidence for a selective advantage of the hemoglobin S heterozygote in a malarious region. The sickling rates of cells infected with Plasmodium falciparum and of non-infected cells were studied both in the total absence of oxygen (by dithionite addition) and at several different concentrations of oxyhemoglobin which might obtain in vivo. In all cases, red cells containing small plasmodium parasite forms (ring forms) sickled approximately eight times as readily as uninfected cells. Cells containing large parasitic forms (trophozoites and schizonts) appeared to sickle less readily than uninfected cells, by light microscopy criteria, but electron micrographs demonstrated the presence of polymerized deoxyhemoglobin S with a high frequency. It is concluded that enhanced sickling of plasmodium-infected AS cells may be one mechanism whereby the hemoglobin S polymorphism is balanced in favor of the heterozygote.

Anemia, Sickle Cell↗