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Biomedical subjects

M A Muniain

Publications and source records attributed to M A Muniain.

At least 19 recordsLinked to original sources
PubMed2004

Cytomegalovirus mononucleosis as a cause of prolonged fever and prominent weight loss in immunocompetent adults.

Four immunocompetent adults presented with protracted fever lasting > 6 weeks and severe weight loss, associated with primary cytomegalovirus (CMV) infection. Each patient had spleen enlargement, lymphocytosis and hypertriglyceridaemia, but recovered spontaneously. A further 20 immunocompetent patients with primary CMV infection were also reviewed, and all presented the usual clinical picture of CMV mononucleosis. It was concluded that CMV mononucleosis should be considered in the differential diagnosis in patients with prolonged fever and weight loss if lymphocytosis is present.

Adult↗
PubMed2003

Leptin stimulates the oxidative burst in control monocytes but attenuates the oxidative burst in monocytes from HIV-infected patients.

Leptin, the 16 kDa product of the ob gene, is a an adipocyte-secreted hormone that centrally regulates weight. However, the physiological role of leptin is not limited to the regulation of food intake and energy expenditure, and leptin has a variety of effects in peripheral tissues, such as a regulatory role modulating the immune system. Thus, leptin receptor is expressed in human peripheral blood mononuclear cells, mediating the leptin stimulation of proliferation and activation, the production of proinflammatory cytokines from cultured monocytes, and the prevention of apoptotic death in serum-deprived monocytes. Because leptin can stimulate monocytes and the production of reactive oxygen species (ROS) are the result of monocyte activation, we investigated the effect of leptin on ROS production by human monocytes in vitro. Oxidative burst was measured by oxidation of the redox-sensitive dye 2',7'-dichlorofluorescein diacetate, and analysed by flow cytometry. We have found that stimulation with leptin produces oxygen radical formation by monocytes. This effect is dependent on the dose and maximal response is achieved at 10 nM leptin. Because HIV infection induces the production of ROS, we next investigated the effect of leptin on ROS production in monocytes from HIV-positive (HIV+) subjects. We have also found that monocytes from HIV+ subjects spontaneously produced increased amounts of free radicals. In contrast, leptin stimulation of monocytes from these patients partially inhibited the production of ROS. This effect of leptin was also dependent on the dose and maximal effect was achieved at 10 nM. The effect of leptin stimulating the production of ROS is consistent with the proinflammatory role in the immune system. On the other hand, the inhibitory effect on monocytes from HIV+ subjects may be explained by the attenuation of the oxidative burst by a delayed activation of monocytes in a hyperinflammatory state.

Adult↗
PubMed2003

Factors associated with time to sputum smear conversion in active pulmonary tuberculosis.

OBJECTIVE: To ascertain the factors affecting the time between the initiation of treatment and obtaining three negative sputum smears. DESIGN: In a study of 109 patients with pulmonary tuberculosis, the main variable was the period during which the patients had sputum smears once treatment was initiated. Multivariate analysis (multiple linear regression) was performed to document those variables independently associated with time to conversion. RESULTS: The patients had positive smears for a mean of 28.63 days. The most frequent radiographic pattern was cavitary disease (36.7%). HIV co-infection was present in 38.5% of the patients. HIV-infected patients showed a cavitation pattern in only 9.6% vs 52.2% of patients without HIV infection (P < 0.001). The variables that showed a statistically significant and independent relationship with the time to sputum smear conversion were pulmonary radiographic pattern, age and erythrocyte sedimentation rate (ESR). CONCLUSIONS: ESR, age and the presence of cavitary disease seem to be factors associated with a longer time to sputum smear conversion in patients with active pulmonary tuberculosis. However, HIV co-infection is associated with a shorter time to sputum conversion. A key factor is therefore the presence or not of cavitation, independently of HIV infection.

Adult↗
PubMed2002

[Nocardiosis in patients with HIV infection].

OBJECTIVE: To know the characteristics of nocardiosis in HIV infected patients. PATIENTS AND METHODS: Retrospective analysis of HIV infected patients with a concomitant Nocardia spp. infection in nine Andalusian hospitals. RESULTS: Eighteen cases of nocardiosis were studied. Seventeen patients were males and the mean age was 33.1 years. The risk behaviour for acquiring HIV infection was parenteral drug use in 15 patients (83.3%) and seven of them were active users when acquiring nocardiosis. The mean CD4 lymphocyte count was 66.3 106/l. The nocardiosis was manifested as disseminated disease in eight patients, only pulmonary disease in four cases, lymphocutaneous or soft-tissue nocardiosis in five, and pericarditis in the remaining patient. In the ten cases with pulmonary involvement, the chest X-ray revealed an alveolar, interstitial, and mixed pattern in five, three, and two patients, respectively. Most patients were treated with cotrimoxazole, with good clinical and microbiological responses in 88.8% of them. Some surgical procedures were required in six patients. Eight patients died, three on account of nocardiosis and five on account of other causes. There were three relapses. CONCLUSIONS: Nocardia spp. infection is rare among patients with AIDS and occurs in immunosuppressed patients and drug users. The pulmonary, cutaneous, and soft-tissue were the most commonly observed forms in our series. Despite the high frequency of disseminated infection, the response to th

Adult↗
PubMed2002

Leptin receptor (Ob-R) expression is induced in peripheral blood mononuclear cells by in vitro activation and in vivo in HIV-infected patients.

Leptin, the Ob gene product, is an adipocyte hormone that centrally regulates weight control. In addition, other effects of leptin in peripheral tissues have been described. Thus, leptin has been found to regulate reproduction, haematopoiesis and immune function. We have found recently that leptin has a stimulatory effect on human peripheral blood mononuclear cells (PBMC). Monocytes are activated by leptin alone whereas T lymphocytes need a suboptimal stimulus of PHA or ConA before further activation by leptin. These effects are mediated by the long isoform of the leptin receptor, which has been shown to trigger signalling in PBMC. In fact, we have found that human leptin stimulates Janus kinase (JAK)-signal transducer and activator of transcription (STAT), phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) pathways in PBMC. In order to assess possible regulation of the long isoform of the leptin receptor (Ob-R) in mononuclear cells upon activation, we have studied the expression of Ob-R by RT-PCR and Western blotting in PBMC activated in vitro by PHA or ConA and in vivo in HIV-infected patients. We have found that in vitro activation and in vivo HIV infection correlates with an increase in leptin receptor expression in PBMC. Moreover, the leptin receptor is tyrosine phosphorylated in PBMC from HIV-infected patients, suggesting that the leptin receptor is activated. These results are consistent with the suggested role of leptin in modulating the immune response.

Adolescent↗
PubMed1998

Genotypic identification of an undescribed spotted fever group rickettsia in Ixodes ricinus from southwestern Spain.

An undescribed rickettsia was directly analyzed with specific rickettsial molecular biology tools on Ixodes ricinus L. collected in different localities of the province of Cadiz (southwestern Spain). On the basis of the results of the citrate synthase (glta) gene, 190 kD-outer membrane protein (rOmpA) gene, and 16S ribosomal RNA (16S rRNA) gene partial sequence data, it was found that this rickettsia is sufficiently genetically distinct from other Rickettsia to be considered a distinct taxonomic entity. The isolation and culture of this organism, as well as comparative antigenic analysis, are required to ensure its conclusive taxonomic placement among spotted fever rickettsiae. The epidemiologic role of this new rickettsial agent and its possible pathogenicity to wild and domestic animals or humans is still unknown and needs to be investigated.

Amino Acid Sequence↗
PubMed1993

Late onset Papillon-Lefèvre syndrome? A chromosomic, neutrophil function and microbiological study.

We had the opportunity to study a family with one of the most destructive forms of periodontal disease known, the Papillon-Lefèvre syndrome. The parents had no consanguinity and were not affected, and were therefore to be considered carriers of the disease. 2 sisters, the eldest and youngest, showed periodontal breakdown and hyperkeratotic skin lesions, but their deciduous dentition was not affected. 2 brothers had skin lesions only and another brother and sister were healthy. Furthermore, 2 babies died at birth one after a 9-month pregnancy and the other after a 6-month pregnancy, and the mother also suffered 3 miscarriages. For 4 years, we studied the family: in the case of both sisters, mechanical periodontal treatment and antibiotics were unable to control the disease. In the chromosomic study of the 2 sisters affected, the GTG banding technique found no trace of anomalies in the cells analyzed, whose chromosomic formation was 46,XX. Before treatment, the chemotaxis of the PMN, the phagocytosis of opsonized Staphylococcus aureus, and production of superoxide radicals by PMN was significantly impaired in both sisters. Despite scaling and root planing, the periodontal lesions still progressed, but the PMN functions evaluated were now normal in both sisters. An orally asymptomatic but dermatologically affected brother showed no significant defect in the phagocytic activity and the production of superoxide radicals.

Adult↗
PubMed1992

Primary idiopathic osteolysis: description of a family.

A clinical, analytical, and radiological study was carried out on three members of the same family with multicentric idiopathic osteolysis. Transmission appeared to be via the dominant autosome present in the mother and two daughters. In the daughters osteolysis was seen in the carpal and tarsal bones, whereas in the mother radiology showed it to be in the phalanges of the hands and feet.

Adolescent↗
PubMed1991

Circadian variations in the superoxide production, enzyme release and neutrophil aggregation in patients with rheumatoid arthritis and controls.

Patients with rheumatoid arthritis (RA) experience fluctuations of symptoms throughout the day. These could be due to mechanical changes or modification of the inflammatory mechanisms. In the present paper we studied fluctuations of superoxide production (O2), enzyme release (beta-glucuronidase and lysozyme) and neutrophil aggregation in the peripheral blood of eight healthy volunteers and eight patients with RA. Although enzyme release was greater in patients with RA, no significant difference was found throughout the day, neither in control nor in patients. Similar results were obtained when studying neutrophil aggregation. On the contrary, the superoxide production, determined at 8:00, 14:00, and 20:00 h, was 6.3 +/- 0.5, 4.40 +/- 0.4 and 6.26 +/- 0.3, respectively, in patients with RA and 6.65 +/- 0.7, 4.7 +/- 0.7 and 7.27 +/- 0.4 in the controls. The values obtained at 14:00 h were significantly lower (alpha = 0.01). There were no differences in the curve form between patients and controls.

Arthritis, Rheumatoid↗
PubMed1989

[Circadian variations in the production of superoxide and liberation of lysosomal enzymes of neutrophils in peripheral blood].

Superoxide formation and lysosomal enzyme liberation circulating neutrophils has been assessed in healthy subjects. Blood samples were obtained at 8:00, 14:00, and 20:00 o'clock. The formation of superoxide followed a circadian rythm. Lowest concentration was found a 14:00 hours (4.59 +/- 2.09 nM reduced cytochrome/10(6) neutrophils). No 24 hour variation of betaglucuronidase and lysozyme liberation was proven. The number of neutrophil receptors for formyl-methyonil-leucyl-phenyl-alamine (FMLP) at the same hours did not show any circadian variation. The circadian changes of the functional capacity of the neutrophils might be one of the mechanisms that could justify the 24 hour variation of symptomatology characteristic of some diseases.

Adult↗
PubMed1988

[Effect of corticosteroids, quinacrine and L-652, 731 on experimental aggregation of polymorphonuclear leukocytes induced by complement and platelet activating factor (PAF)].

The effects of 6-methylprednisolone sodium succinate, quinacrine and the synthetic anti-PAF compound L-652,731 were studied on the PAF and complement induced aggregation of rabbit polymorphonuclear leukocytes in vivo. High doses (100-250 mg/kg) of corticosteroid were able to abrogate PAF and complement induced aggregation. Quinacrine (1.25 mg/kg), and L-652,731, partially precluded complement-depending aggregation. The L-652,731 dose employed was just enough to prevent PAF induced aggregation. These results suggest that in those pathological conditions in which polymorphonuclear aggregation occurs, factors other than those derived from plasmatic complement system activation, and laboring jointly with it, may be involved.

Agranulocytosis↗