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Biomedical subjects

L López

Publications and source records attributed to L López.

At least 73 records · Page 4Linked to original sources
PubMed1997

[High cardiac output in myeloma patients. Its prevalence and clinical characteristics. The Castile-León Cooperative Group for the Study of Monoclonal Gammapathies].

BACKGROUND: The study determines the prevalence of high cardiac output status in patients with multiple myeloma (MM) and its relationship with the more significant clinical and biological characteristics of the disease. PATIENTS AND METHODS: Cardiac output was determined in 28 patients with multiple myeloma by pulsed Doppler echocardiography. Patients with any other identifiable cause of high cardiac output were excluded. Mean age was 70 +/- 8 SD years (53-84). A stepwise regression with the cardiac output as dependent variable and age, performance status (ECOG), clinical stage (Durie and Salmon), scale of bone lesions, serum calcium, serum creatine, bone involvement (percentage), and M protein quantity as independent variables showed the following results. RESULTS: A high cardiac output state, defined as a cardiac index higher than 4.6 l/min/m2 was present in five patients (17.8%), four of them with severe bone involvement. Two patients developed heart failure. The stepwise regression revealed the scale of bone lesions was the unique variable associated with the risk of developing a high cardiac output status. CONCLUSIONS: A high cardiac output status may be fairly common in patients with multiple myeloma. The syndrome is associated with severe bone involvement, being the scale of bone lesions the only risk factor for this complication.

Aged↗
PubMed1997

Analysis of mitomycin C-induced micronuclei in lymphocytes from malnourished infected children.

The purpose of this study was to determine if peripheral blood lymphocytes from malnourished children with gastrointestinal or respiratory bacterial infection show increased frequencies of Mitomycin C (MMC)-induced micronuclei as compared to well-nourished, infected children. The results indicate that cells from malnourished, infected children had greater chromosome damage. This may indicate that such children would be more susceptible to environmental damage and malignant transformation. Micronucleus frequencies were analyzed in binucleate cells produced by the cytokinesis block method; the overall micronucleus frequency was significantly higher in binucleate cells from malnourished, infected children. The mean micronucleus frequency in MMC-free cultures was 4.3/1000 in malnourished infected children and 1.0/1000 in well-nourished infected children. In MMC-exposed cultures the mean induced micronucleus frequency was 32.6 +/- 6.1 vs. 12.9 +/- 2.3; 68.6 +/- 12.1 vs. 21.0 +/- 5.1, and 88.1 +/- 16.2 vs. 41.7 +/- 5.0 for malnourished and well-nourished children at 20, 40, and 60 ng/ml MMC, respectively. The number of binucleated cells with more than one micronucleus was also higher in malnourished, infected children at all doses tested, including cells with two micronuclei in MMC-free cultures from malnourished, infected children. This increase was not found in peripheral blood lymphocytes from well-nourished infected children.

Antibiotics, Antineoplastic↗
PubMed1997

Hydatid disease of bone with adjacent joint involvement. A radiological follow-up of 12 years.

Osseous lesions have been reported in only 1-2% of patients with hydatid disease. Joint involvement is usually due to secondary extension from the adjacent bone, although primary hydatid synovitis after haematogenous spread of the infection can be seen. We present a long-term radiological follow-up (12 yr) in a patient who developed hydatid disease of the left pelvic and femoral bones with cartilage destruction of the ipsilateral hip joint. After a Girdlestone arthroplasty, she received mebendazole (3 g/day) for 10 yr and albendazole (400 mg/day) for 2 yr with radiological impairment of the lesions. Complete surgical excision is the treatment of choice for osseous hydatid disease. Isolated medical therapy with mebendazole or albendazole is not adequate for controlling the process, but it can be added to surgery or, as in our case, used like isolated therapy when complete excision is not possible.

Albendazole↗
PubMed1997

The coat protein is required for the elicitation of the Capsicum L2 gene-mediated resistance against the tobamoviruses.

In Capsicum, the resistance against tobamoviruses conferred by the L2 gene is effective against all but one of the known tobamoviruses. Pepper mild mottle virus (PMMoV) is the only virus which escapes its action. To identify the viral factors affecting induction of the hypersensitive reaction (HR) mediated by the Capsicum spp. L2 resistance gene, we have constructed chimeric viral genomes between paprika mild mottle virus (PaMMV) (a virus able to induce the HR) and PMMoV. A hybrid virus with the PaMMV coat protein gene substituted in the PMMoV-S sequences was able to elicit the HR in Capsicum frutescens (L2L2) plants. These data indicate that the sequences that affect induction of the HR mediated by the L2 resistance gene reside in the coat protein gene. Furthermore, a mutant that codes for a truncated coat protein was able to systemically spread in these plants. Thus, the elicitation of the host response requires the coat protein and not the RNA.

Amino Acid Sequence↗
PubMed1997

The aberrant cell walls of boron-deficient bean root nodules have no covalently bound hydroxyproline-/proline-rich proteins.

B-deficient bean (Phaseolus vulgaris L.) nodules examined by light microscopy showed dramatic anatomical changes, mainly in the parenchyma region. Western analysis of total nodule extracts examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that one 116-kD polypeptide was recognized by antibodies raised against hydroxyproline-rich glycoproteins (HRGPs) from the soybean (Glycine max) seed coat. A protein with a comparable molecular mass of 116 kD was purified from the cell walls of soybean root nodules. The amino acid composition of this protein is similar to the early nodulin (ENOD2) gene. Immunoprecipitation of the soybean ENOD2 in vitro translation product showed that the soybean seed coat anti-HRGP antibodies recognized this early nodulin. Furthermore, we used these antibodies to localize the ENOD2 homolog in bean nodules. Immunocytochemistry revealed that in B-deficient nodules ENOD2 was absent in the walls of the nodule parenchyma. The absence of ENOD2 in B-deficient nodules was corroborated by performing hydroxyproline assays. Northern analysis showed that ENOD2 mRNA is present in B-deficient nodules; therefore, the accumulation of ENOD2 is not affected by B deficiency, but its assembly into the cell wall is. B-deficient nodules fix much less N2 than control nodules, probably because the nodule parenchyma is no longer an effective O2 barrier.

Boron↗
PubMed1997

Portacaval shunt control animals: physiological consequences derived from the sham operation.

The portacaval shunt in the rat is a frequently used experimental model of portosystemic encephalopathy. Among other consequences of this surgical preparation is an important decrease in hepatic and testicular volume. Different sham-operation methods including a laparotomy were used as controls in each case. Given that the liver volume varies greatly in comparison to body weight in the sham-operated animals, this paper aims to evaluate the possible consequences of the sham operation. It concludes that control animals without manipulation, in addition to the respective controls of portacaval shunt, should be used in every case.

Analysis of Variance↗
PubMed1997

Prevalence of stroke in two samples (rural and urban) of old people in Spain. A pilot door-to-door study carried out by health professionals.

The aim of this study was to present the prevalence of stroke from a pilot study in old people. The urban site sample (Madrid) was made up of 397 subjects and the rural site sample (Arévalo, Avila) of 862 subjects. The study was performed with a door-to-door methodology. In the urban sample, the prevalence of stroke was 8.5% (CI 95% = 5.5-11.5%) and that of TIA was 2.1% (CI 95% = 0.6-3.6%). In the rural location the prevalence of stroke was 7.1% (CI 95% = 5.4-8.8%). This prevalence of stroke is higher than in other Spanish studies. These results need to be confirmed in a wider investigation.

Aged↗
PubMed1997

Astrocyte-derived cytokines contribute to the metastatic brain specificity of breast cancer cells.

The occurrence of breast cancer metastases is preferential to certain organs. Astrocytes may play an important role in the development of brain metastases, as these cells have been shown to respond to extracellular stimuli by producing many cytokines and growth factors that can modulate tumor cell proliferation, growth, and/or metastases. To test this hypothesis, we analyzed the responses of the human breast cancer cell line MDA-MB-435 and its metastatic sublines to astrocyte primary cultures from newborn rat cerebra. Astrocyte purity of the glial cell cultures was demonstrated by glial fibrillary acidic protein and rat neural antigen-2 (Ran-2) immunopositive staining. The 435-Br1 cell line, which was derived from a brain metastases in a nude mouse, showed increased adhesion to astrocytes and enhanced growth in vitro in the presence of media from Con A-stimulated astrocytes, relative to the parental MDA-MB-435 and the lung metastasis-derived variant 435-Lung2. Furthermore, the growth-stimulatory effect was partially reversed by anti-IL-6, anti-transforming growth factor beta (anti-TGF beta), and anti-IGF-I antibodies, indicating that these metastatic cells use exogenous cytokines as paracrine growth factors. In an attempt to elucidate the role of several biologic-response modifiers produced by astrocytes, we tested the responses of MDA-MB-435 cells to purified cytokines and growth factors. We found that the addition of recombinant human or mouse IL-6 produced a variety of responses in the different 435 metastatic variants. Furthermore, IL-6 receptor (IL-6R) expression was slightly increased in the 435-Br1 cells, and exogenous IL-6 rescued 435-Br1 cells from apoptosis in serum-depleted cultures. No apoptotic protective effect was observed in either MDA-MB-435 parental cells or 435-Lung2 cells. Thus, responses to exogenous IL-6 might determine the differences among these metastatic variants by extending cell survival of selected subpopulations, giving them the opportunity to respond to growth factors or other favorable conditions that might be present. These results suggest that cytokines produced by glial cells in vivo may contribute, in a paracrine manner, to the development of brain metastases by breast cancer cells.

Adult↗
PubMed1996

Study of lens autofluorescence by fluorophotometry in pregnant patients with diabetes.

PURPOSE: Lens autofluorescence originates from an accumulation of fluorescent substances such as the tryptophan-derived residues and glycosylated protein aggregations, which are associated with the process of cataractogenesis and lens aging. The purpose of this investigation is to determine whether pregnancy alters the typical constituents of the lens autofluorescence in patients with diabetes and, if so, to what degree this may occur. METHODS: Lens autofluorescence was studied with fluorophotometry in 127 eyes of 72 individuals: 23 control subjects, 6 healthy pregnant women, 21 patients with diabetes, and 44 pregnant patients with diabetes. RESULTS: The autofluorescence values were 311 +/- 130 ng/ml, 253 +/- 40 ng/ml, 378 +/- 110 ng/ml, and 562 +/- 164 Eq ng/ml (Eq ng/ml = Ng/ml equivalent fluorescein) in the four groups, respectively. The difference between the nonpregnant and pregnant patients with diabetes was significant (P < 0.001). CONCLUSION: These results suggest that there is an important deterioration in the metabolic state of the lens during gestation in patients with diabetes, as is the case for diabetic retinopathy.

Adult↗
PubMed1996

Massive hemoptysis as a manifestation of fistulized thoracic aortic aneurysms into the bronchial tree.

Aortobronchial fistulas are an uncommon and serious cause of hemoptysis. We present three cases of aortobronchial fistulas that were diagnosed and treated at our hospital. They were presented as massive hemoptysis. The clinical suspicion of a leaking thoracic aortic aneurysm into the bronchial tree should prompt the correct diagnostic procedures since early surgery is the only way to manage this condition.

Aged↗
PubMed1995

The Capsicum L3 gene-mediated resistance against the tobamoviruses is elicited by the coat protein.

The L3 gene is responsible for the hypersensitive response in Capsicum plants against infection by tobamoviruses. The resistance conferred by this gene is one of the most effective so far described against tobamoviruses. Certain isolates of pepper mild mottle virus (PMMV) are the only tobamoviruses able to overcome the L3 resistance. Chimeric viral genomes between PMMV-S (to which L3 plants are hypersensitive) and PMMV-I (an L3 resistance-breaking isolate) led us to conclude that sequence variation within the coat protein gene of both isolates determines their different virulence in L3L3 plants. Furthermore, the results indicate that a single amino acid substitution, Asn to Met, at position 138 of the PMMV-I coat protein is sufficient to induce the hypersensitive response and localization of viral infection in C. chinense plants. Finally, the use of a mutant coding for a truncated coat protein (maintaining the Met138 coding sequence at the RNA level) demonstrates that a functional coat protein is required for elicitation of the L3 gene-mediated resistance.

Base Sequence↗
PubMed1995

[Traumatic hemothorax treated by video-assisted thoracoscopic surgery].

The introduction of video-assisted thoracic surgery (VTS) has significantly furthered the use of the thoracoscope in surgery. In the case we describe, a 79-years-old man at high risk for surgery came to our hospital with hemothorax due to trauma. The necessary procedure was performed successfully with VTS, which allowed for the repair of an acute condition that would otherwise have been treated conventionally by way of posterolateral thoracotomy. We conclude that VTS may play an important role in the diagnosis and treatment of certain thoracic injuries, so that surgery involving more extensive bleeding is rendered unnecessary.

Accidental Falls↗
PubMed1995

Transbronchial fine needle aspiration in clinical practice.

We review our experience of transbronchial fine needle aspiration (TBFNA) over a 3-year period. A total of 112 TBFNAs were performed on 95 patients. Four aspirates were from peripheral lung lesions, 20 from non-ulcerated submucosal infiltrative lesions, 19 from mediastinal abnormalities close to the tracheobronchial tree, and the remaining 69 were for staging of bronchogenic carcinoma with apparent mediastinal lymph node spread, evaluated by chest computed tomography (CT). In the 20 submucosal lesions TBFNA reached a sensitivity of 82.3%, providing the only evidence of a malignant process in five cases. With respect to the 19 mediastinal lesions arising in close proximity to the central airways, TBFNA permitted a diagnosis in cases that would otherwise have required more invasive procedures, although the diagnostic sensitivity of the technique in this group of patients was poor (26%). In the mediastinal staging group, the sensitivity was 76.9%, with no false positive results. Complete sensitivity of TBFNA for the detection of disease was 65.8%. We conclude that TBFNA is a reliable and low risk procedure.

Adolescent↗
PubMed1995

Tubulin aggregates induced by Ni2+ present microtubular characteristics.

Rat brain tubulin in a proper buffered solution became insoluble in the presence of 10 mM NiCl2, and sedimented at centrifugal forces as low as 500 x g for 30 min. Both nickel-sedimented and microtubular tubulin conserved 65% of colchicine binding activity after 25 days of storage at -20 degrees C. However in brain cytosol, only 9% of the initial binding activity was conserved. The electrophoretic mobility of tubulin recovered from aggregates also remained unaltered. Therefore the aggregates formed with Ni2+ share important physicochemical properties with microtubules.

Animals↗