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Biomedical subjects

E Muñoz

Publications and source records attributed to E Muñoz.

At least 109 records · Page 6Linked to original sources
PubMed1997

Role of ascorbate in the activation of NF-kappaB by tumour necrosis factor-alpha in T-cells.

The first product of ascorbate oxidation, the ascorbate free radical (AFR), acts in biological systems mainly as an oxidant, and through its role in the plasma membrane redox system exerts different effects on the cell. We have investigated the role of ascorbate, AFR and dehydroascorbate (DHA) in the activation of the NF-kappaB transcription factor in Jurkat T-cells stimulated by tumour necrosis factor-alpha (TNF-alpha). Here we show, by electrophoretic mobility shift assays, that ascorbate increases the binding of NF-kappaB to DNA in TNF-alpha-stimulated Jurkat cells. The ability of ascorbate to enhance cytoplasmic inhibitory IkBalpha protein degradation correlates completely with its capacity to induce NF-kappaB binding to DNA and to potentiate NF-kappaB-mediated transactivation of the HIV-1 long terminal repeat promoter in TNF-alpha-stimulated Jurkat cells but not in cells stimulated with PMA plus ionomycin. AFR behaves like ascorbate, while DHA and ascorbate phosphate do not affect TNF-alpha-mediated NF-kappaB activation. These results provide new evidence for a possible relationship between the activation of the electron-transport system at the plasma membrane by ascorbate or its free radical and redox-dependent gene transcription in T-cells.

Ascorbic Acid↗
PubMed1997

Neurophysiological investigations in patients with head tremor.

We studied 30 patients whose primary complaint was head tremor in an attempt to characterize neurophysiological aspects of their abnormal movement. Based on family medical history and physical examination, 23 patients had definite or probable essential tremor (essential head tremor, EHT). The remaining seven had mild dystonic signs accompanying their head tremor (head tremor plus dystonic signs, HT + DS). We recorded head movement and the electromyographic (EMG) activity of the sternomastoid and splenius capitis muscles, determined the spontaneous blinking rate, and measured the excitability recovery curve of the blink reflex and of the masseteric inhibitory reflex. All patients had tremor bursts at a frequency ranging between 3 and 9 Hz in at least one of the muscles examined. The predominant pattern seen when patients were sitting relaxed and facing forward was that of synchronized EMG bursts in both splenius capitis muscles. Maintenance of extreme head postures demonstrated two types of additional abnormalities: type 1 (enhancement of tremor), which was observed in 11 patients (47.8%) with EHT and in two (28.5%) with HT + DS; and type 2 (activation of neck muscles not required for maintenance of the posture), which was observed in two patients (8.7%) with EHT and in five (71.5%) with HT + DS (chi 2 = 26.4; p < 0.001). Mean blinking rate per minute was 24.9 +/- 14.6 in patients with EHT and 42.3 +/- 10.5 in patients with HT + DS (paired t test, p = 0.001). The blink reflex and masseteric inhibitory reflex excitability recovery curves showed an abnormal interneuronal excitability enhancement in seven (30.4%) of the 23 patients with EHT and in two (28.5%) of the seven with HT + DS (chi 2 = 3.1; p > 0.05). Abnormal patterns of EMG activity of the neck muscles correlated well with the presence of mild dystonic signs. However, the analysis of brainstem interneuronal excitability did not enable recognition of those patients with head tremor who could potentially develop cervical dystonia. The enhancement of brainstem interneuronal excitability found in approximately 30% of patients with head tremor could be related to plastic changes triggered by increased activity of the cranial muscles.

Adult↗
PubMed1997

Duodenal leishmaniasis diagnosed by biopsy in two HIV-positive patients.

We describe two cases of duodenal leishmaniasis in patients with human immunodeficiency virus (HIV) infection, diagnosed by light and electron microscopy. The patients presented nonspecific signs and symptoms, blood cultures were sterile, and serological tests for Leishmania spp. were negative. Endoscopy showed normal-appearing mucosa in one patient and possible peptic duodenitis in the other patient. In these patients, the parasite was only detected in a duodenal biopsy specimen. In view of the unusual location of the parasite and the fact that the diagnostic and dissemination of the disease was established by means of conventional biopsy, this is not a routine procedure for the diagnosis of leishmaniasis because the classic procedures require the demonstration of antibodies and visualization in bone marrow, lymph nodes, liver and/or spleen aspirates. We decided to report these two cases to call attention to the possible finding of Leishmania amastigotes in biopsies from intestinal mucosa in HIV infected patients.

Adult↗
PubMed1997

Epithelioid hemangiomas of the maxillofacial area. A report of three cases and a review of the literature.

Epithelioid hemangioma, also named angiolymphoid hyperplasia with eosinophilia, is a very rare tumor that arises from vascular structures. The relative incidence in the skin of the head and neck area is rather high as compared to other parts of the body. Three cases are reported in an atypical location and the differential diagnosis with other similar vascular lesions and their pathologic features is presented.

Adult↗
PubMed1997

Zinc supplementation reduced morbidity, but neither zinc nor iron supplementation affected growth or body composition of Mexican preschoolers.

In rural Mexico and in many developing countries micronutrient deficiencies, growth stunting, and morbidity from infectious diseases are highly prevalent in young children. We assessed the extent to which growth stunting could be reversed and the number of infectious disease episodes reduced by zinc and/or iron supplementation. In a double-blind, randomized community trial 219 Mexican preschoolers were supplemented with either 20 mg Zn as zinc methionine, 20 mg Fe as ferrous sulfate, 20 mg Zn + 20 mg Fe, or a placebo. After 12 mo, plasma zinc increased significantly in the two zinc-treated groups, and plasma ferritin was significantly higher in the two iron-treated groups. There was no effect of treatments on growth velocity or body composition. Children in both zinc-supplemented groups had fewer episodes of disease (zinc alone, 3.9 +/- 0.3; zinc+iron, 3.7 +/- 0.4; placebo, 4.6 +/- 0.5; P < 0.03), including diarrhea (zinc alone, 0.7 +/- 0.1; zinc+iron, 0.8 +/- 0.1; placebo, 1.1 +/- 0.2; P < 0.01). Zinc and zinc+iron supplements reduced morbidity but had no effect on growth or body composition.

Body Composition↗
PubMed1997

Humoral immune response in Yersinia enterocolitica O:5 induced arthritis in hamsters.

Yersinia enterocolitica can cause extraintestinal sequelae such as reactive arthritis. The immunopathogenic mechanisms of this disease have not been completely clarified. Autoimmunity and persistent immune responses against bacterial antigens have been related to Yersinia-induced arthritis. The arthritogenic capacity of Y. enterocolitica O:5 and the kinetics of the development of autoantibodies and Yersinia antigen-specific antibodies were studied in hamsters. The results indicated that Y. enterocolitica O:5 was arthritogenic in the animal model studied. The animals developed septic arthritis on day 2 post-infection (p.i.) and reactive arthritis on day 65 p.i. An important IgG response to types I and II collagen and the persistence of antibodies against lipopolysaccharide and bacterial cellular extract were observed. By immunoblotting, it was obtained that IgG reacted against a large number of bacterial antigens, the strongest being the responses against 88, 76, 63 and 36-33 kDa peptides. From the results obtained, it can be concluded that serovar O:5 was experimentally arthritogenic, and that both autoimmune mechanisms and Yersinia-specific antibodies participated in the development of Yersinia-induced reactive arthritis in the animal model studied.

Animals↗
PubMed1997

Cellular redox status influences both cytotoxic and NF-kappa B activation in natural killer cells.

The role of cellular redox status in both cytotoxic activity and NF-kappa B activation in natural killer (NK) cells was investigated. The results indicate that stimulation of NK cells, either freshly isolated from peripheral blood lymphocytes (PBL) or long-term cultured NK clones, with specific cell targets results in an increased binding activity of NF-kappa B and AP-1 transcription factors measured by gel retardation. Pretreatment of NK cells with the antioxidant pyrrolidine dithiocarbarmate (PDTC) leads to the inhibition of NF-kappa B activation but the AP-1 binding to DNA was superinduced. The inhibition of NF-kappa B by PDTC paralleled with an inhibition of spontaneous cytotoxicity mediated by NK cells. Moreover, the inhibitors of serine proteases, N-alpha-tosyl-L-lysine chloromethyl ketone and N-alpha-tosyl-L-phenylalanine chloromethyl ketone, also blocked the cytolytic activity of NK cells against the sensitive target K562. In contrast, NK activity was not affected by pretreatment of the effector cells with the proteasome inhibitor N-acetyl-leu-leu-norleucinal which selectively inhibits NF-kappa B activation. Altogether, these results support the hypothesis that the activation of NK cells involved transcriptional and post-transcriptional events, and that reactive intermediates may play an important role in the molecular processes related with the generation of a cytotoxic response by NK cells.

Antioxidants↗
PubMed1997

Herpetic syringitis associated with eccrine squamous syringometaplasia in HIV-positive patients.

Herpetic syringitis has been described as a rare manifestation of herpes virus infection in patients with an immunodeficiency, usually secondary to human immunodeficiency virus (HIV) infection. Eccrine squamous syringometaplasia (ESS) is an infrequent alteration of the eccrine duct epithelium reported in association with several conditions, including chronic ulcers, inflammatory processes, and patients receiving chemotherapy. The association of herpetic syringitis with ESS has not been reported before. We identified 3 cases of herpetic syringitis associated with ESS in patients with the acquired immunodeficiency syndrome. In 2 of 3 cases the signs of herpetic syringitis were limited to the metaplastic duct epithelium, but in 1 case there were also herpetic alterations without ESS. The histological features of herpetic infection in HIV-positive patients may be atypical and lack the typical epidermal alterations, observing only an extensive epidermal necrosis. In those cases, the alterations of the eccrine ducts may be a diagnostic clue in the diagnosis of herpetic infection. ESS of the ductal epithelium is probably secondary to the herpetic infection, although it might also stimulate the extension of the herpetic infection. Further studies are needed to elucidate the association of ESS and herpes virus infection.

AIDS-Related Opportunistic Infections↗
PubMed1997

Thrombocytopenia in the antiphospholipid syndrome.

OBJECTIVE: To determine the prevalence of thrombocytopenia in a group of patients suffering from the antiphospholipid syndrome (APS) and to investigate whether these patients may have any particular clinical or serological features. METHODS: Retrospective analysis. A group of 171 APS patients seen in our department were studied for the presence of thrombocytopenia. Clinical and serological features of these patients were analysed by standard methods and each of them was correlated to the presence of thrombocytopenia and compared with those found in the group without thrombocytopenia. RESULTS: Each of the patients studied had a minimum of three platelet counts during the follow up period. Forty (23.4%) were found to have thrombocytopenia; 13 with persistently low and 27 patients with intermittently low platelet counts. There were no statistically significant differences in sex, age, disease duration or diagnosis when compared with the group of APS patients without thrombocytopenia. Thrombocytopenia was associated with thrombosis in 18, with miscarriages in five, and with both of these features in 13 patients. It was the only manifestation of the APS in four patients. All patients had persistently positive tests for antiphospholipid antibodies concomitantly with the low platelet counts. No significant association was found between the presence of thrombocytopenia and clinical or serological manifestations in APS patients. CONCLUSION: This study showed a prevalence of thrombocytopenia of 23.4% in APS. These patients did not present any significant clinical or serological features that distinguish them from those patients without thrombocytopenia.

Adult↗
PubMed1997

Scientific organizations in Spain (1950-1970): social isolation and international legitimation of biochemists and molecular biologists on the periphery.

Through a study of Spanish scientific organizations and the involvement of Spanish scientists in international ones, the beginnings of biochemistry and molecular biology in Spain are explored. The centre-periphery dichotomy is useful in explaining the progress of the establishment of these disciplines, together with the political context, both national and international, in which such establishment took place. It is suggested that international ties and national support are both necessary, but not sufficient conditions to overcome the distance between the Spanish scientific community and the centres of development and productivity in biochemistry and molecular biology. The interplay between both national and international factors has proved to be crucial. As a tool to study the whole scientific community of biochemists and molecular biologists, scientific societies allow us to analyze the role of that interplay in Spanish scientific development.

Biochemistry↗
PubMed1997

[Laparoscopic Nissen fundoplication in children with encephalopathy].

Conventional management of gastroesophageal reflux (GER) and hiatus hernia in children affected with encephalopathy can deteriorate their pulmonary function, already compromised by their leaning position and their spine deformations. The results after laparoscopic surgery for GER in 6 encephalopathy children are reviewed; their ages ranged from 9 to 14 years, their accompanying diseases were: spastic tetraparesia, hydrocephalus, scoliosis, epilepsy and Reye's syndrome. The laparoscopy procedures followed the same surgical steps as open surgery; the surgical time was 3 to 5 hours; the average hospital stay was 3 days. Oral intake started 8 hours after surgery. The successful results of these first cases in this group of patients with neurologic anomalies, suggest that laparoscopic Nissen funduplication is the treatment of choice for GER and hiatus hernia.

Adolescent↗
PubMed1997

Simultaneous detection of antigens and specific DNA sequences of human papillomavirus in uterine cervical biopsy specimens. Description of a double-labelling technique.

We studied 70 uterine cervical biopsy specimens with a histological diagnosis compatible with human papillomavirus (HPV) infection. We carried out immunohistochemical and in situ hybridization techniques and selected 22 specimens that had given a positive result with both techniques. We then used a double-labelling technique (a combination of immunohisto-chemistry and in situ hybridization) to detect simultaneously viral antigens and specific gene sequences of HPV. With this technique we found three different cell types in the tissue: (1) cells with black nuclei, positive by immunohisto-chemistry and in situ hybridization; (2) cells with red nuclei, negative by immunohistochemistry and positive by in situ hybridization; and (3) cells with light blue nuclei, negative by both techniques. In this study we describe this technique; and we believe that the simultaneous detection of viral antigens and specific gene sequences of HPV may be very useful in the study of the virus-cell interaction.

Antigens, Viral, Tumor↗
PubMed1996

Prevalence of sarcoptic mange in fattening pigs sacrificed in a slaughterhouse of northeastern Spain.

A study was conducted in fattening pigs from NE Spain to determine the prevalence of sarcoptic mange. Pigs were sacrificed in a slaughterhouse in the province of Barcelona (Catalonia, NE Spain) in November 1990, April 1991, and October 1991. From 7906 pigs slaughtered on those dates, 818 ear scrapings were taken. The survey results indicate that 276 (33.7%) of 818 pigs sampled from 58 (86.6%) of 67 herds were positive for Sarcoptes scabiei (De Geer). The presence of Sarcoptes-induced skin lesions was examined in 816 pigs. Of the 660 pigs showing skin lesions, 244 (37.0%) were positive for mites. A sucrose flotation-concentration method was more effective than a direct examination technique to detect S. scabiei mites.

Abattoirs↗
PubMed1996

Hepatic Morphological alterations induced by zidovudine (ZDV) in an experimental model.

Zidovudine (AZT) inhibits HIV replication. Many studies have demonstrated its toxic myopathic effect in both HIV-positive patients treated with the drug and experimental animal models. So far hepatic lesions induced by AZT have not been reported. In our study, an experimental rat model was used in which the rats were administered AZT (1 mg/ml) in drinking water; histological and ultrastructural alterations were observed in the liver of treated animals and compared with the findings in control animals. The histological alterations detected were turbid swelling, vacuolar degeneration and microvacuolar fatty degeneration of panlobular distribution; these lesions were progressively greater as the duration of treatment increased. The ultrastructural alterations detected involved the mitochondria (similar to those described in cardiac muscle), smooth and rough endoplasmic reticulum (SER and RER), and the accumulation of fat and glycogen in the hepatocytes of treated animals. The histopathological and ultrastructural findings in our experimental model suggest hepatotoxicity induced by AZT or its catabolites in treated, as compared to control animals.

Animals↗