Search PubMed⌕ Search

Biomedical subjects

M Rodriguez

Publications and source records attributed to M Rodriguez.

At least 667 records · Page 37Linked to original sources
PubMed1983

Myasthenia gravis in children: long-term follow-up.

We report observations made on 149 patients with juvenile myasthenia gravis studied from onset of disease for as long as 40 years. Median follow-up was 17 years; minimum was 4 years. Eight other patients with congenital myasthenia gravis were studied separately. Of the juvenile myasthenic patients, 85 (57%) underwent thymectomy because of diseases severity. In juvenile myasthenia gravis, a spontaneous remission rate of 22.4 per 1,000 person-years was observed, regardless of disease duration. A remission rate of 260 per 1,000 person-years was seen during the first year after thymectomy, with a rate of 95 per 1,000 person-years during the next 2 years. Early surgery, presence of bulbar symptoms, absence of ocular signs or generalized symptoms, onset of symptoms between ages 12 and 16, and presence of other immune disease were associated with increased postoperative remission rates. Epilepsy (4 patients) and neoplasia (7 patients) were the most frequent associated nonimmune disorders; rheumatoid arthritis (5 patients), juvenile-onset diabetes mellitus (3 patients), asthma (3 patients), and thyroid disease (3 patients) were the most frequent associated immune diseases.

Adolescent↗
PubMed1983

Virologic models of chronic relapsing demyelinating disease.

The present report, compares two murine models of virus induced chronic relapsing demyelination. MHV-induced demyelination in the BALB/c mouse results from the direct virus mediated cytolysis of oligodendrocytes. Extensive remyelination by oligodendrocytes is noted. Recurrent demyelination occurs in small areas. Infectious virus persists and viral antigens are localized within oligodendrocytes and their processes. TMEV-induced demyelination in SJL/J mice is associated with perivascular inflammatory infiltrates and is diminished by immunosuppressive measures. Remyelination by oligodendrocytes is delayed and incomplete. Chronic demyelination is widespread and associated with perivascular inflammatory infiltrates. The virus persists and viral antigen is localized within oligodendrocytes. The findings indicate virus persistence in oligodendrocytes in both models. Demyelination follows the disintegration of infected oligodendrocytes. Virus replication in oligodendrocytes is responsible for cell lysis in the MHV model whereas immune mediated injury of infected oligodendrocytes is considered to play a role in the pathogenesis of demyelination in the TMEV model.

Animals↗
PubMed1983

Humoral immunologic abnormalities in workers exposed to asbestos cement dust.

Serum specimens from 144 workers exposed to asbestos cement dust were examined for the presence of ANA, RF, immunoglobulins, and IC. These immunologic findings were compared with chest radiographic changes. A high percentage of workers had polyclonal hypergammaglobulinemia, and there was a statistically significant association between elevated levels of IgG and IgM and radiographic classification. Although a significant number of workers had an increased prevalence of ANA and elevated levels of IC, there was no correlation between these parameters and chest radiographs. These findings support B cell hyperactivity in workers exposed to asbestos and suggest that autoantibody production and IC are not directly involved in disease pathogenesis.

Adult↗
PubMed1983

Testes weight reflect ethylnitrosourea induced histopathology in mice.

The powerful mutagen/carcinogen ethylnitrosourea (ENU) decreases testis weight in mice. A histopathological cause was determined for this effect. Groups of 3 mice were injected with 0, 50, 100 or 200 mg ENU/kg b.w. and were killed 1, 2, 4, 5, 7, 9, 13 or 15 weeks later. Microscopic examination of PAS-hematoxylin-stained sections showed a dose-and-time-dependent loss of germ cells from the seminiferous tubules 1-7 weeks after treatment followed by recovery from the damage. Testis weight decrease and recovery followed a similar course.

Animals↗
PubMed1983

Ultrastructural localization of viral antigens in the CNS of mice persistently infected with lymphocytic choriomeningitis virus (LCMV).

Lymphocytic choriomeningitis virus (LCMV) produces a persistent infection of the nervous system in susceptible mice. To map the localization of viral antigens in the central nervous system (CNS), the authors studied, by means of ultrastructural immune peroxidase techniques, 4-6-month-old mice persistently infected with LCMV following an intracerebral inoculation at birth. The greatest number of infected neurons was observed in the cortex, particularly of the limbic system, and certain nuclei of the hypothalamus. In the cerebellum, Purkinje cells selectively expressed viral antigens. Moderate numbers of infected neurons were found in the anterior horns of the spinal cord, basal ganglia, and thalamus. The immunoperoxidase technique using monoclonal antibodies showed that persistently infected neurons primarily expressed the nucleocapsid protein antigens of LCMV. Glycopeptide antigens were minimally expressed. Electron-microscopic examination of selected individual infected neurons showed viral antigens exclusively associated with ribosomes. No staining was seen on cell surfaces. Glutaraldehyde-fixed CNS tissue studied by electron microscopy did not reveal morphologic abnormalities or mature viral particles. This study demonstrates that LCMV persistently infects specific neuronal populations. Infected neurons express viral antigens in association with host ribosomes and show no significant morphologic alterations.

Animals↗
PubMed1983

Early changes in experimental allergic neuritis.

Edema and increased endoneurial fluid pressure (EFP) accompany the inflammatory process in experimental allergic neuritis. EFP was measured at regular intervals 6 to 21 days after intradermal inoculation of Lewis rats with an emulsion of peripheral nerve in complete Freund's adjuvant. Control rats received similar injections of an emulsion containing all other ingredients, except peripheral nerve. Altered vascular permeability was illustrated by leakage of horseradish peroxidase into rat sciatic nerve endoneurial space as early as 10 days after inoculation. A difference in EFP between controls and test animals became apparent after 11 days, and highest values were obtained 12 to 16 days postinoculation. Nerves were excised for histologic examination after EFP measurement. Severe endoneurial edema was present after 12 days and was associated with appreciable inflammatory cell infiltration. Inflammatory cells were clustered around small vessels and also were numerous in the subperineurial space which was expanded by edema. Degranulation of mast cells was also noted in association with edema and inflammation. Immunoperoxidase staining revealed immunoglobulin in the subperineurial and perivascular spaces 10 to 12 days postinoculation, but not in sections 6 to 9 days (postinoculation). These findings suggest suggest that altered vascular permeability is the earliest morphologic change in experimental allergic neuritis, followed by accumulation of antibody-containing edema fluid, penetration of the endoneurium by inflammatory cells, and increased EFP.

Animals↗
PubMed1983

Neonatal infection with the Daniels strain of Theiler's murine encephalomyelitis virus.

The clinical and pathologic manifestation of Theiler's murine encephalomyelitis are age related. Animals infected during the first week of life die of a fulminant encephalitis analogous to human poliomyelitis. By contrast, animals infected within 2 and 4 weeks of age survive but develop chronic relapsing demyelination and persistent infection of the central nervous system. The neonatal infection results in widespread necrosis beginning with neuronal vacuolar degeneration followed by inflammatory infiltrates. Electron microscopy reveals paracrystalline arrays of 27-nm viral particles characteristic of picornaviruses within neurons and macrophages. In addition, oligodendrocytes show reactive changes and intracytoplasmic vacuoles. Immunoperoxidase studies show viral antigen primarily localized within neurons of the cerebral cortex, basal ganglia, hippocampus, and anterior horn cells. Viral antigen is found within the apical dendrites and axonal projections of hippocampal pyramidal cells suggesting that Theiler's murine encephalomyelitis may travel intraaxonally.

Animals↗
PubMed1983

Factors associated with prognosis in human breast cancer. II. Multivariate stratification analysis.

Prediction of the individual fate of breast cancer patient is one of the most important problems for establishment of therapeutic plans. We have analyzed the relationships of clinical factors to 3-year and 8-year survivals in a series of 400 patients treated for breast carcinoma. Multivariate stratification analysis for obtaining subgroups with different survivals was performed with the aid of Bintree, a computer program which produces binary splits of a population according to the criterion of maximal reduction of variance, and generates a binary stratification tree. Lymph node status was the major predictor for both short and long term prognosis but had no important role in the survival of patients who relapsed. Antecedent abortions were related to less relapses. Age, previous benign breast diseases, nulliparity and lactation conditioned better prognosis without association with relapse probability, indicating an association with the speed of evolution of the disseminated disease. In general clinical data were insufficient for establishment of good and bad prognosis polar groups of patients, especially in patients in which no clinical lymph node involvement was recorded.

Adult↗
PubMed1983

Pituitary dwarfism in mice persistently infected with lymphocytic choriomeningitis virus.

Most strains of mice injected intracerebrally with lymphocytic choriomeningitis virus grow to adulthood maintaining a persistent virus infection associated with chronic virus-induced immune complex disease. However, mice on a k background are highly susceptible to neonatal infection and develop the clinical syndrome of pituitary dwarfism and hypoglycemia. Examination of pituitary tissue fails to reveal morphologic alteration by light and electron microscopy. Within the pituitary, viral antigens are exclusively distributed within the cells of the adenohypophysis. Using ultrastructural colloidal gold-labeling techniques, we demonstrate the presence of mature virus particles budding from the surface of growth hormone containing cells from the pituitary. This study indicates that persistent lymphocytic choriomeningitis virus infection of the growth hormone cells in susceptible mice is associated with pituitary dwarfism without producing visible structural damage.

Animals↗
PubMed1983

Factors associated with prognosis in human breast cancer. I. Predictors for rate of evolution and relapse.

The associations of several clinical factors with general survival, percentage of relapse and survival in the group of patients who relapsed were analyzed in a series of 399 Stage II breast cancer patients operated and irradiated at the Institute of Oncology and Radiobiology in Havana. In another series of 187 patients these associations were studied in regard to the presence of estradiol receptors in the tumors. Factors related to the presence of estrogen receptors were unrelated to the percentage of relapse in long term follow-up. Age and menstrual status were related to the presence of estradiol receptors and to survival inside the group of patients who relapsed but were unrelated to the percentage of relapses. Lymph node status was mainly associated with the percentage of relapses but not related to the presence of estradiol receptors. Other factors (parity and age at first childbirth), related to the presence of receptors, did not clearly influence prognosis. Lactation influenced positively survival inside the relapse group without any clear association with hormone receptors. Results are discussed in terms of a model considering particular host--tumor interaction: The probability of relapse and the speed of evolution of the systemic disease, mutually independent, but determining the prognosis.

Adult↗
PubMed1982

Virus-induced alterations in homeostasis: alteration in differentiated functions of infected cells in vivo.

The noncytopathic lymphocytic choriomeningitis virus displays a tropism for the anterior lobe of the murine pituitary gland. Virus replicates in cells that make growth hormone. This results in a diminished synthesis of growth hormone with a concomitant clinical picture of retarded growth and hypoglycemia. However, there is no morphologic evidence of either cell necrosis or inflammation in the anterior lobe of the pituitary. Hence, during infection in vivo, a noncytopathic virus may turn off the "differentiation" or "luxury" function of a cell while not killing that cell (loss of vital function). This is turn can disrupt homeostasis and cause disease. This model illustrates a novel way whereby viruses may cause disease.

Animals↗
PubMed1982

Central neurogenic hyperventilation in an awake patient with brainstem astrocytoma.

A patient had the rare combination of central neurogenic hyperventilation (PaCO2 of 9 torr) and a normal level of consciousness for eight days. Morphine attenuated but never corrected the hyperventilation. Experimental effects of hypocapnia, which decreases both cerebral blood flow and metabolism in humans, are at odds with the normal mentation initially seen in this patient despite her marked and persistent hypocapnia. Death occurred after progressive brainstem dysfunction. Pathological study showed a well-differentiated astrocytoma involving primarily the medulla and pons, with scattered tumor foci throughout the entire neuraxis. Possible mechanisms for central neurogenic hyperventilation are discussed briefly in relation to the pathological findings and the observed response to morphine.

Arteries↗
PubMed1982

Canine GM1 gangliosidosis. An ultrastructural and biochemical study.

The ultrastructural and biochemical features of canine GM1 gangliosidosis were studied. beta-Galactosidase activity assayed using both skin fibroblast tissue culture strains and fresh skin revealed enzyme activities in three groups (normals, heterozygotes, and homozygotes) corresponding to an autosomal recessive inheritance. The concentration of ganglioside GM1 was greatly increased in cerebral gray matter and kidney. A striking elevation of tissue oligosaccharides was found in liver, kidney, and spleen. Most neurons in the cerebral cortex and deep gray matter were filled by spherical lamellated inclusions. Hepatocytes contained vacuoles with an amorphous granular material which may correspond to the accumulation of galactose-oligosaccharides determined chemically. The disease in dogs has features similar to both the infantile and juvenile form of human GM1 gangliosidosis.

Animals↗
PubMed1981

Experimental antireflux intestinal valve.

A reflux-preventing valve was obtained by invaginating a 3.5 to 4.5 cm segment of small bowel into the distal lumen, after removing the seromuscular layers at both ends of the segment of bowel. Antiperistaltic pressure resistance, measured at regular intervals during 6 months, showed valves with competence equal or superior to the ileocecal valve. The blood supply to the intussuscepted segment must be carefully preserved.

Animals↗