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Biomedical subjects

A López

Publications and source records attributed to A López.

At least 19 recordsLinked to original sources
PubMed1997

Peritoneocele: visualization with defecography and peritoneography performed simultaneously.

PURPOSE: To evaluate the use of simultaneous defecography and peritoneography (defecoperitoneography) in patients with an unexplained widening of the rectovaginal space noted at defecography. MATERIALS AND METHODS: Twenty-two patients with unexplained widening of the rectovaginal space noted at defecography were studied with defecoperitoneography. Defecoperitoneography was a combination of defecography and peritoneography with water-soluble contrast medium administered intraperitoneally. RESULTS: The outline and movements of the peritoneum and alterations in the pelvic peritoneal cavity could be visualized with defecoperitoneography during the dynamic act of defecation. Unexplained widening of the rectovaginal space was completely due to a peritoneocele in 14 patients and partially due to a peritoneocele in six patients. In two patients, there was no peritoneocele. Only nine of 22 patients had bowel in the unexplained widening (enterocele). Three patients had a rectal peritoneocele; six, a septal peritoneocele; one, a vaginal peritoneocele; and 10, a combination of these findings. CONCLUSION: Visualization of the pelvic floor with defecoperitoneography is improved compared with visualization with defecography alone.

Adult↗
PubMed1996

Long lasting immunological effects of ethanol after withdrawal.

The aim of the present study was to analyze on chronic alcoholic patients the effect of ethanol (EtOH) withdrawal on the immune system through the investigation of the distribution of PB lymphoid subsets, using multiple-stainings with monoclonal antibodies and flow cytometry. For this purpose a group of 20 patients with active alcoholism without liver disease, negative for hepatitis virus, and without malnutrition was analyzed and followed for 9 months after alcohol consumption had been discontinued. Twenty-five age- and sex-matched healthy volunteers were included in the study. The following panel of monoclonal antibodies combinations (FITC/PE/PerCP or PE-Cy5) was used: TCR alpha beta/CD3/HLA DR, CD25/CD56/CD3, TCR gamma delta/CD3/HLA DR, CD45RA/CD45R0/CD4, CD3/CD8, CD19/CD5, and CD3/CD11c. Analysis was performed on at least 1,500 events/tube at flow cytometry using the Lysys II software program. During the alcohol intake period, the most striking findings were a significant (P < 0.05) expansion of the CD8+ T-lymphocyte subset, which coexpresses the activation associated antigens HLA DR and CD11c, as well as a significant increase in both NK-cells (CD3-/CD56+) and the T-cell subset with NK activity coexpressing CD3 and CD56 (P < 0.05 and P < 0.01, respectively). In addition, a decrease in the CD5+ B-cells (P < 0.05), associated with reduced serum gamma-globulin levels, was also observed. During alcohol withdrawal, a rapid decrease towards normal values of activated CD8+/HLA DR+ and CD11c+ T-lymphocytes was observed as well as a normalization of CD19+/CD5+ B-cells and gamma-globulin serum levels; these changes might be directly related to EtOH suppression. Surprisingly, however, new immunological imbalances emerged in spite of the absence of alcohol intake. Thus, a progressive and significant expansion (P < 0.05) of CD4+ T-cells associated with an increased expression of the CD25 activation-related antigen and a preferential use of the CD45R0 isoform by CD4+ T-cells were observed. In parallel, there was an even more evident increase (P < 0.01) in the number of PB NK-cells. Our results show that EtOH consumption induces changes in the immune system, its effects persisting or even becoming more evident after suppression of EtOH intake for a 9 month period.

Alcoholism↗
PubMed1996

Toxicity of potential irritants in mammalian cells in vitro.

Four bioactive materials were tested for their ability to produce toxicity in vitro in two cell lines: rabbit corneal cells (SIRC) and human fibroblasts. These compounds are widely used by industries, causing toxic effects to ecosystems and particularly having an impact on human health. Different chemicals were chosen which were structurally unrelated: triethanolamine, zinc pyrithione, sodium lauryl sulfate, and oleamine. Cytotoxicity was evaluated measuring the total protein content (inhibition of cell growth). Results indicated that zinc pyrithione produced the highest inhibition of cell growth when two cell lines were treated in the two doses tested. The lowest cytotoxic effect was observed with oleamine. Triethanolamine and sodium lauryl sulfate produced a similar cytotoxic effect in Fe cells, although sodium lauryl sulfate revealed higher inhibition of cell growth than triethanolamine on SIRC cells. From these results, it can be concluded that some products as triethanolamine and zinc pyrithione should be observed in future special toxicological studies.

Amines↗
PubMed1996

Imipenem therapy of brain abscesses.

The efficacy of imipenem versus standard chemotherapy (both in addition to neurosurgery) in the treatment of brain abscess was compared in a retrospective study. Cure was obtained in 52 of 60 (86.7%) patients in the standard group, and in 15 of 15 (including 5 patients with multiple brain abscesses) in the imipenem group. Cure without neurosurgery was observed in 2 of 60 (3.3%) and 3 of 15 (20%) of the cases, respectively (p = 0.08). Levels of imipenem in blood, cerebrospinal fluid, and brain pus were above the minimum inhibitory concentrations of most of the abscess isolates. Side effects of imipenem were rare and tolerance was excellent. Imipenem monotherapy (3-4 g/day) for five weeks seems a reasonable therapeutic choice for treatment of bacterial brain abscesses.

Adolescent↗
PubMed1996

Cytoprotective activity of cisapride on experimental gastric mucosal lesions induced by ethanol. Role of endogenous prostaglandins.

The antiulcer effects and protective mechanisms of cisapride, a prokinetic benzamide agonist of 5-HT3 and antagonist of 5-HT4 receptors, were investigated in gastric mucosal injury induced by pretreatment with 50% v/v ethanol in rats. The duration of the protective effect was also studied and the results were compared with those of 5-HT. 240 min after administration of cisapride (10, 25 and 50 mg/kg) the total area of gastric lesions decreased significantly, in macroscopical and histological evaluations, and the mucus, hexosamine, and sulphated glycoprotein content were significantly increased. Indomethacin partially reversed cisapride protection suggesting that the beneficial antiulcer effects of this drug could be mediated in part by prostaglandins. This study confirms that this benzamide, in this experimental model, enhances gastric PGE2 production. We also investigated the time course of action of 5-HT, 30-240 min before ethanol administration, and our study not only demonstrates the ulcerogenic action of the amine (30 min of pretreatment) but also its protective nature, shown macroscopic and microscopically, after 240 min of its administration, without any effect on PGs production. These findings suggest a new gastroprotective feature of cisapride partly explained through a prostaglandin-dependent mechanism and possibly independent of its 5-HT activity.

Animals↗
PubMed1996

CD5+ B cells in Graves' disease: correlation with disease activity.

In the present paper the distribution of peripheral blood CD5+/CD19+ (CD5+B) and CD5-/CD19+ (CD5-B) B-lymphocytes in Graves' disease (GD) patients is analyzed in order to correlate them with disease activity, interleukin-2 (IL-2) and IL-6 binding to T and B cells as well as with anti-thyrotropin (TSH) receptor antibodies and the thyroid hormone serum levels. The combination of flow cytometry and 3-color immunofluorescence revealed a remarkable increase in the absolute numbers of CD5+ B cells in hyperthyroid-untreated GD patients (218 +/- 137 x 10(6)/l vs. 66 +/- 69 x 10(6)/l in healthy subjects, p < 0.01) that gradually fell to normal values once hyperthyroidism had been controlled by methimazole. However, relative numbers of CD5+ B cells persisted at a relatively stable but increased level in GD patients in long term remission of an average of 3.1 years. This was also confirmed in a follow-up study of a group of 12 newly diagnosed patients during the first 90 days of anti-thyroid drug therapy with methimazole. No correlation was observed between either CD5+ B cells or CD5- B cells and the serum levels of pathogenic anti-TSH receptor antibodies. Increased numbers of CD5+ B cells were related to the increased free thyroxine and total triiodothyronine serum levels. In addition, a strong correlation between both the absolute levels of B cells binding to exogenous IL-2 and IL-6 and the absolute number of CD5+ B cells in hyperthyroid GD patients (LR = 0.798, p < 0.001; LR = 0.569, p < 0.01, respectively) was observed. These results suggest that CD5+ B cells in GD are partly regulated by thyroid hormone serum levels as well as by IL-2 and IL-6 binding to B cells. Nevertheless, they are not involved, at least directly, in the production of anti-TSH receptor antibodies.

Adult↗
PubMed1996

Distribution of peripheral blood lymphoid subsets in alcoholic liver cirrhosis: influence of ethanol intake.

The aim of the present study was to investigate the effect of chronic ethanol (EtOH) consumption on the immune system in patients with alcoholic liver cirrhosis (ALC), as analyzed by the distribution of peripheral blood (PB-) T, B, and NK lymphoid subsets using multiple stainings with monoclonal antibodies and flow cytometry. For that purpose, we have analyzed a group of patients with ALC and active EtOH intake (ALCET group) which were re-evaluated 3 months after alcohol withdrawal. As controls, both ALC patients with at least 1 year of alcohol withdrawal (ALCAW group) and healthy subjects were used. Regarding the alcohol intake period, the most relevant findings were a significant activation of the PB T-cell compartment, and specifically of the TCR alpha beta + subset, as reflected by an increased expression of both the HLA DR and CD11c antigens as well as a significant increase of both the PB NK cells (CD3-/CD56+) and the cytotoxic T cells coexpressing the CD3 and CD56 molecules. In addition, a decrease of both the numbers of total B cells and their CD5+/CD19+ subset were observed. After a relatively short withdrawal period (3 months), the abnormalities of T, P, and NK cells disappeared. These findings suggest the existence of a close relationship between EtOH consumption and the abnormalities of the immune system observed during active alcoholism. Nevertheless, ALCAW individuals displayed marked alterations on the immunophenotypic profile, as reflected by a significantly decreased number of total T cells, due to reduced levels of the CD3+/TCR alpha beta+, CD4+, CD8+, and CD4+/CD45RA+ T-cell subsets. In addition, a significantly decreased number of total PB B cells was observed in this group of patients. Our results show that in patients suffering from ALC, the abnormalities of the immune system due to a direct effect of EtOH intake (or its metabolites) should be distinguished from the immunological alterations related to the liver disease itself.

Alcohol Drinking↗
PubMed1996

The role of gastric mucosal sulphydryls in the ulcer-protecting effects of cisapride.

The present study was designed to examine the role of endogenous sulphydryls (SHs) in the gastro-protection induced by cisapride (CIS) (10, 25 and 50 mg kg-1 i.p.), a potent benzamide stimulating gastrointestinal motility in mucosal injury induced by 50% v/v ethanol. Results were compared with those of 5-hydroxytryptamine (5-HT) (10mg kg-1). Ethanol mucosal damage was significantly reduced by treatment with CIS and 5-HT. On the contrary, administration of n-ethylmaleimide (NEM) (10 mg kg-1) an SH alkylator, markedly worsened lesion formation and counteracted the protective effect of CIS. Rats pretreated with CIS significantly increased the total sulphydryls as reflected in the non-protein and protein fractions however, 5-HT treatment showed a fall in the non-protein level. The present results suggest that 5-HT-ergic dependent mechanisms have no relation to the gastro-protection afforded by CIS in this experimental model. It is possible that mucosal SHs could be involved.

Animals↗
PubMed1996

Pharmacokinetics of conventional formulation versus fat emulsion formulation of amphotericin B in a group of patients with neutropenia.

The pharmacokinetics of amphotericin B administered in a conventional 5% dextrose (glucose) (5% D) solution and in a 20% fat emulsion formulation (Intralipid; 20% IL) were compared in 16 patients (mean age, 42 years [range, 18 to 70 years]) who had been hospitalized for hematological malignancies and with proven or suspected fungal infections. All of the patients received 50 mg (approximately 1 mg/kg of body weight per day) of amphotericin B daily in random order, either as a 50-ml lipid emulsion (20% IL) (group I) or in 500 ml of 5% D (group II). Five serum samples were taken during the 24 h after drug administration, and the levels of amphotericin B were measured by high-pressure liquid chromatography. Serum amphotericin B concentrations declined rapidly during the first 6 h, and subsequent measurements revealed a slow terminal elimination phase in both groups. The maximum serum amphotericin B concentration was significantly lower when the drug was administered in 20% IL (1.46 +/- 0.61 versus 2.83 +/- 1.17 micrograms/ml; P = 0.02). The area under the concentration-time curve from 0 to 24 h was also much lower in group I (17.22 +/- 11.15 versus 28.98 +/- 15.46 micrograms.h/ml). The half-life of the distribution phase was approximately three times longer in group I (2.92 +/- 2.34 h versus 0.64 +/- 0.24 h; P = 0.011). Conversely, the half-lives of the elimination phase were approximately equal in the two groups (11.44 +/- 5.18 versus 15.23 +/- 5.25 h). The mean residence times were also similar in both groups (19.41 +/- 11.13 versus 19.65 +/- 7.86 h). The clearance and the steady-state volume of distribution of amphotericin B in group I were about twice as great as those in group II (62.97 +/- 35.51 versus 33.01 +/- 14.33 ml/kg/h and 1,043.92 +/- 512.10 versus 562.32 +/- 152.05 ml/kg [P = 0.034], respectively). Finally, the volume of distribution in the central compartment was greater in group I than in group II (618.17 +/- 231.80 versus 328.19 +/- 151.71 ml/kg; P = 0.013), but there were no differences in the volume of distribution in the peripheral compartment (425.75 +/- 352.87 versus 234.14 +/- 75.92 ml/kg). These results suggest that amphotericin B has a different pharmacokinetic profile when it is administered in 20% IL than when it is administered in the standard 5% D form and that the main difference is due to a clear-cut difference in the steady-state volume of distribution, especially that in the central compartment.

Adolescent↗
PubMed1996

Serial analysis of the effects of methimazole therapy on circulating B cell subsets in Graves' disease.

The immunosuppressive effects of antithyroid drug therapy are well recognized; however, the cellular mechanisms underlying their action remain largely unknown. In the present paper we have prospectively analyzed the in vivo effects of methimazole treatment on a large number of circulating B cell subsets, involved in the effector phase of the immune response, in a group of 18 hyperthyroid patients with Graves' disease (GD). The patients were sequentially studied before (day 0) and 7, 14, 30, 90 and 180 days after methimazole therapy. The results were compared with both a group of 19 age- and sex-matched healthy controls and a group of 20 untreated/euthyroid GD patients in long-term remission. The combination of flow cytometry and three colour immunofluorescence revealed a clear increase (P < 0.001) in the numbers of circulating total B cells (CD19+) due to a significant increase (P < 0.001) in the CD5+, FMC7+, CD5+/ FMC7+ and CD23+ B cell subsets in hyperthyroid GD patients with respect to both healthy individuals and to GD patients in long-term remission. The absolute numbers of all these B cell subsets analyzed before treatment, although abnormal, were not statistically different from those observed during the whole period of therapy. When comparing the percentages of these B cell subsets during treatment, significant changes (P < 0.001) were only observed in the proportion of CD5+, CD5+/FMC7+ and CD5- B cells at the end of the follow-up period with respect to those found both before and during the first month of therapy. Whereas CD5+ and CD5+/FMC7+ B cells decreased (P < 0.001) after 3 months of therapy, CD5- B cells showed a significant increase (P < 0.001) at the end of therapy. It is remarkable that the percentage of CD5+, CD5+/FMC7+, CD5- and CD23+ B cell subsets were abnormal during the whole period of treatment and that they never reached normal values. These results show that, in vivo, GD patients treated with methimazole exhibited an abnormal but rather stable pattern of B cell distribution, similar to that present in hyperthyroid untreated GD patients, except for the CD5+ and CD5- B cell populations. Our findings suggest that in vivo methimazole therapy would not directly have an important influence on circulating B cell subsets.

Adult↗
PubMed1996

[Sensory-motor polyneuropathy associated with lung tuberculosis: presentation of two new cases].

The association of active tuberculosis with changes in the peripheral nervous system is not well defined, although it is included amongst the neuro-muscular disorders of the peripheral nerve diseases due to infective agents. We describe the case of two patients with sensory-motor polyneuropathy and coexistant active pulmonary tuberculosis which was untreated prior to diagnosis of the peripheral nervous system disorder. In both cases the condition was sub-acute and did not improve until treatment was begun. Anti-tuberculosis treatment was followed by marked improvement of both the pulmonary tuberculosis and of the polyneuropathy. The close chronological relationship of both clinical pictures with the therapeutic response supports the hypothesis of the pathogenesis of the peripheral nervous system disorder being mediated by an anomolous immune response, initiated by the infection with Koch's bacillus.

Adult↗
PubMed1995

DNA aneuploidy in acute myeloblastic leukemia is associated with a high expression of lymphoid markers.

In the present study the DNA cell content of 205 de novo acute myeloblastic leukemia (AML) patients is analyzed at flow cytometry in order to determine both the incidence of DNA aneuploidy in AML patients and the clinical and biological characteristics of AML aneuploid cases. All technical procedures were performed in accordance with the proposed guidelines of the DNA Cytometric Consensus Conference. Our results show that the incidence of DNA aneuploidy is quite low (4.8%), with most cases (n = 8) hyperdiploid and only a small proportion (n = 2) hypodiploid. No major differences were detected between the aneuploid and diploid cases with respect to the clinical and prognostic disease characteristics. Regarding the immunophenotype of the blast cells, the aneuploid cases displayed both a higher incidence of immature myeloblastic phenotype and a greater expression of lymphoid-associated antigens. In summary, our results show that AML patients display a quite low incidence of DNA aneuploidy and that despite the fact that these cases do not display particular clinical characteristics, they show an association with the expression of lymphoid-related markers.

Adult↗
PubMed1995

Gastroprotection induced by silymarin, the hepatoprotective principle of Silybum marianum in ischemia-reperfusion mucosal injury: role of neutrophils.

Investigations were carried out to determine the antiulcer effects of silymarin, the hepatoprotective principle of Silybum marianum L. Gaertn., in gastric injury induced by ischemia-reperfusion and its effects on mucosal myeloperoxidase activity, an index of polymorphonuclear leukocyte infiltration, after injury in rats. These results were compared with those from rats that received allopurinol, an inhibitor of xanthine oxidase and with those from rats made neutropenic by prior administration of dexamethasone and methotrexate. Pretreatment with silymarin prevented post-ischemic mucosal injury. The mean ulcer indexes (U.I.) of rats treated with 25, 50 mg, and 100 mg silymarin/kg body weight (4.79 +/- 0.75, 4.50 +/- 0.81, and 3.63 +/- 0.74, respectively) were significantly lower (p < 0.05, 0.05, and p < 0.005) than that of control rats. Allopurinol was considerably more potent in reducing the U.I. than silymarin, with a calculated U.I. of 2.33 +/- 0.45, p < 0.001. These protective effects were specifically related to a reduction in the number of neutrophils in the gastric mucosa. Reduction in the numbers of circulating neutrophils by treating rats with methotrexate (MPO level of 7.2 x 10(-2) +/- 0.56 x 10(-2)U/mg wt) and dexamethasone (MPO level of 6.97 x 10(-2) +/- 0.68 x 10(-2)U/mg wt) also resulted in a significant reduction in the susceptibility to gastric damage induced by ischemia-reperfusion. These results suggest that neutrophils play an important role in the gastric mucosal dysfunction associated with ischemia-reperfusion. These findings also indicate that the inhibitory effects of silymarin on neutrophil function may contribute significantly to its gastroprotective actions.

Animals↗
PubMed1995

Presentation of an acquired factor VIII inhibitor with a muscular haematoma mimicking a deep venous thrombosis in a patient with breast cancer.

Acquired haemophilia is a rare disorder that it is associated with several diseases. Patients may present with spontaneous haematomas in different places which can sometimes be fatal. We present a 69-year-old woman with breast carcinoma who developed a factor VIII inhibitor. The initial haemorrhagic event was a spontaneous deep muscular haematoma in the right leg mimicking a deep venous thrombosis. She was successfully treated with prednisone.

Aged↗
PubMed1995

Prognostic value of S-phase cells in AML patients.

Until now, reports on the cell cycle distribution of AML patients have shown highly variable results which are probably related to the technical heterogeneity of such studies. The aim of the present paper was to analyse in 204 AML patients at diagnosis the proliferative rate (assessed by the number of S-phase cells) of peripheral blood (PB) (126 cases) and bone marrow (BM) (78 cases) cells in order to explore its relationship with disease characteristics. A strong parallelism was observed regarding the relationship between the proliferative rate of the blast cells both in PB and in BM and the disease characteristics. Cases with a high proliferative rate were associated with advanced age, high WBC counts and LDH serum levels, monocytic leukaemias (assessed both by morphological and immunophenotypic criteria) and NK-associated antigens (CD56, CD16). The proliferative activity did not influence the CR rate; in contrast, cases with a high number of S-phase cells had shorter survival. In addition, multivariate analysis showed that age, the expression of CD11b, and the S-phase counts are the only three prognostic factors displaying an independent impact on survival.

Adult↗
PubMed1995

In vitro bromodeoxyuridine-labelling of single cell suspensions: effects of time and temperature of sample storage.

The present study was aimed to explore how the in vitro BrdUrd-labelling of rat thymocytes might be affected by both the time elapsed between obtaining the sample and the beginning of the labelling (0, 15, 30 or 60 min) and the effect of the temperature of storage (4 degrees C versus room temperature). Single cell suspensions obtained after in vivo labelling with BrdUrd were used as controls. The S phase fraction was calculated by flow cytometry both according to BrdUrd-immunolabelling and DNA content. Immediate incubation with BrdUrd after the sample was obtained resulted in a slight decrease of the proportion of S phase cells analysed either according to DNA content or to BrdUrd-immunolabelling. Regardless of storage-temperature, the S phase fraction decreased in samples kept for 15 min or more before BrdUrd incubation. No BrdUrd-positive cells were detected in samples stored for 60 min at room temperature. This effect was related to temperature since positive cells were found when the samples were kept at 4 degrees C during the same time period. Our results suggest that during in vitro incubation a relative loss of S phase cells exists and that a delay beyond 15 min between obtaining the sample and the in vitro labelling seriously compromises the results of this technique.

Animals↗