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Biomedical subjects

A Moreno

Publications and source records attributed to A Moreno.

At least 163 records · Page 9Linked to original sources
PubMed1999

A new epitope on sheep CD45R molecule detected by a monoclonal antibody.

This paper describes the production and characterization of a monoclonal antibody (mAb), Co-46D5, which recognizes a new epitope on the isoform of the homologous sheep leukocyte common antigen (LCA) or CD45. This nmAb was submitted to the 3rd workshop on ruminant leukocyte antigens and was assigned to a cluster reactive with B- and T-cells subsets. Co-46D recognizes a 220 kDa molecule on peripheral blood mononuclear cells (PBMC) and spleen cells but not on thymocytes. Flow cytometry (FCM) analysis shows that Co-46D5 reacted with 30% of PBMC and 50% of spleen cells and more than 95% of cells freshly isolated from lymphoid follicles of the ileal Peyer's patches (IPP) of young lambs. By immunohistochemistry, the antigen was detected mainly on B-cell areas of lymph nodes and spleen. It was also found on a subpopulation of medullar thymocytes. Based on these results, we assume that Co-46D5 recognizes a new epitope on the largest isoform of the sheep CD45 receptor, probably on the homologous to the human CD45RA isoform.

Animals↗
PubMed1999

Purification, crystallization, and preliminary X-ray characterization of a 36 kDa amaranth globulin.

The purpose of this study was to purify, crystallize, and characterize by X-ray diffraction an amaranth globulin for its subsequent structure elucidation. A 36-kDa amaranth globulin was extracted by sequential precipitation and purified by gel filtration and cationic exchange columns. It was crystallized at 18 degrees C from 4 M sodium formate. Suitable crystals for X-ray analysis were found to belong to the tetragonal crystal system with cell dimensions of a = b = 195.5 A and c = 164.14 A. Two possible tetragonal space groups P4(1)2(1)2 or P4(3)2(1)2 were determined. The crystals diffracted up to 2.5 A.

Chromatography, Gel↗
PubMed1999

Synergistic cooperation between c-Myc and Bcl-2 in lymph node progression of T1 human breast carcinomas.

The overexpression of Bcl-2, an anti-apoptotic oncogene, identifies human T1 breast cancer patients who have an increased risk of lymph-node metastasis. We examined in these patients (n = 142) whether the c-Myc oncogene influences metastatic progression in conjunction or not with Bcl-2 expression and the loss of apoptosis in tumors. The association between Bcl-2 and lymph-node metastasis was only significant when c-Myc was concomitantly expressed (chi2 test, p = 0.008). Moreover, very large associations (pOR = 6.4) between c-Myc and lymph-node metastasis were observed among Bcl-2 positive tumors and tumors with loss of apoptosis (pOR = 8.4). In contrast, the metastatic advantage linked to Bcl-2 was decreased (pOR = 2) when c-Myc was not coexpressed. It is concluded that the synergism between Bcl-2 and c-Myc oncogenes may promote metastasis in breast tumors, linked to loss of apoptosis.

Adult↗
PubMed1999

Role of the intensive care unit in children undergoing bone marrow transplantation with life-threatening complications.

The role of support measures in the Intensive Care Unit for bone marrow transplant recipients has been controversial. Data from 176 pediatric bone marrow transplants were retrospectively analyzed to ascertain the probability, causes, risk factors and survival for life-threatening complications requiring intensive care. Ninety-two patients underwent allogeneic BMT and 84 autologous BMT between January 1991 and December 1995. Thirty-one ICU admissions were recorded. The most frequent causes were acute respiratory failure (n = 15, mostly interstitial pneumopathies), septic shock (n = 5) neurological disorders (n = 5) and heart failure (n = 2). The cumulative incidence of an ICU admission at 20 months post-transplant in patients with an allogeneic BMT was 25.7% (CI: 16.4-35.1), compared with 10.8% (CI: 4.2-17.5) in those with an autologous graft (P = 0.04). ICU admission frequency was maximum during the first 2 months post-transplant. All complications in patients with autologous transplants appeared during the first 5 months post-transplant. Among patients with allogeneic grafts, four were later admitted to the ICU, at 7, 9, 12 and 20 months post-transplant, respectively. The main risk factor for ICU admission was acute GVHD grades III-IV. No differences were found between patients with allogeneic transplants with GVHD grades 0-II and those undergoing autologous transplant. In contrast, differences were highly significant between patients undergoing allogeneic transplants with GVHD grades III-IV and those with GVHD grades 0-II or autologous transplants. No differences were observed between allogeneic and autologous transplants in terms of causes for ICU admission, duration of stay, hours on mechanical ventilation, hours on inotropic drug therapy and numbers of organs failing. Neither were differences found in ICU discharge survival between patients with allogeneic (50%, CI: 29.1-70.9) and autologous (66.7%, CI: 29.9-89.1) transplants. ICU discharge survival in patients admitted for lung disease was 28.6% (CI: 12.1-65.6) but 76.5% (CI: 41.9-87.8) in patients admitted for other causes (P = 0.007). ICU discharge survival in mechanically ventilated patients was 46.2% (CI: 27.0-65.4), significantly lower than nonventilated patients (100%). Three-year survival in all transplanted patients admitted to the ICU was 29.7% (CI: 13.1-45.0) compared with 70.2% (CI: 62.7-77.6) in patients not requiring ICU admission (P<0.001). Although a complication requiring admission to the ICU is, as confirmed by multivariate analysis, an unfavorable factor in long-term survival of transplanted patients, it must be emphasized that three of every 10 patients admitted to the ICU were alive and well at 3 years. Intensive care support in these patients can be life-saving.

Adolescent↗
PubMed1999

Use of hatch date for broiler breeder production planning.

Data on 109 batches of broiler breeders belonging to six strains and bred in conventional sheds were analyzed to determine the possible influence of natural day length cycle phase on age at start of laying, at sexual maturity, and at peak egg production. The dependence of these variables on date of hatching was characterized by polynomial regression analysis. The resulting equations constitute simple, novel empirical models that are in keeping with current theory on the effects of photoperiod on sexual maturation, and should facilitate production planning in broiler breeder farms.

Animal Husbandry↗
PubMed1999

Crystal-growth kinetics of protein single crystals along capillary tubes in the gel-acupuncture technique.

In attempts to obtain protein crystals of a sufficient size for structural studies, lack of knowledge of the physicochemical properties of protein solutions and of their crystal-growth behaviour lead to a bottleneck for drug design as well as for X-ray crystallography. Most formal investigations on crystal-growth phenomena have been focused on equilibrium studies, where the protein is soluble, and on the kinetics of crystal growth, which is related to both nucleation and crystal-growth phenomena. The aim of this work is to measure the crystal-growth rate along a capillary tube used as a growing cell. These experiments were carried out using the gel-acupuncture technique [García-Ruiz et al. (1993). Mater. Res. Bull. 28, 541-546; García-Ruiz & Moreno (1994). Acta Cryst. D50, 484-490; García-Ruiz & Moreno (1997). J. Cryst. Growth, 178, 393-401]. Crystal-growth investigations took place using lysozyme and thaumatin I as standard proteins. The maximum average growth rate obtained in the lower part of the capillary tube was about 35 A s-1 and the minimum average growing rate in the upper part of the capillary tube was about 8 A s-1. The crystal-growth rate as a function of the supersaturation was experimentally estimated at a constant height along the capillary tube.

Chemical Precipitation↗
PubMed1999

Absence of thallium-201 brain uptake in progressive multifocal leukoencephalopathy in AIDS patients.

OBJECTIVE: To evaluate the presence of thallium-201 brain uptake determined by thallium-201 brain SPECT (Tl-201 SPECT) in patients with progressive multifocal leukoencephalopathy (PML) and AIDS. MATERIAL AND METHODS: Six AIDS patients with stereotactic biopsy diagnosis of PML were prospectively evaluated with Tl-201 SPECT, Magnetic Resonance Imaging (MRI), and proton magnetic resonance spectroscopy (1H-MRS). Tl-201 SPECT results were compared with 2 patients with AIDS and biopsy proven primary CNS lymphoma. RESULTS: In all patients with PML, Tl-201 SPECT studies showed lack of uptake while MRI demonstrated subcortical white matter focal brain lesions and 1H-MRS disclosed metabolic abnormalities. Intense thallium uptake (uptake ratios of 3.2 and 5.6) was demonstrated in the 2 patients with primary CNS lymphoma. CONCLUSIONS: The present study shows that PML lesions are not detectable on Tl-201 SPECT while MRI and 1H-MRS demonstrate abnormalities, and intense thallium-201 uptake may be detected in primary CNS lymphoma. These results suggest that Tl-201 SPECT is a method which, combined with other non-invasive techniques such as MRI and 1H-MRS, may help in the diagnostic approach of PML and to differentiate PML from other high proliferative brain lesions characterized by positive thallium uptake.

AIDS Dementia Complex↗
PubMed1999

Proton magnetic resonance spectroscopy pattern of progressive multifocal leukoencephalopathy in AIDS.

The objective was to determine whether the use of intermediate echo times (135 ms) in proton magnetic resonance spectroscopy (1H-MRS) detects a homogenous pattern in progressive multifocal leukoencephalopathy (PML) in HIV-1 infected people, and to confirm the results of previous studies. Six patients infected with HIV-1, with PML established by biopsy, and six healthy age and sex matched volunteers were evaluated to define their spectroscopic pattern. 1H-MRS spectra performed at 1.5 T were obtained with the STEAM sequence: TE/TM/TR, 20 ms/13.7 ms/2000 ms; 2500 Hz, size 2048 points, 256 acquisitions (STEAM-20) and with the PRESS sequence; TE/TR, 135 ms/2000 ms; 2500 Hz, size 2048 points, 256 acquisitions (PRESS-135). A single voxel was placed on the lesions and on the parieto-occipital white matter of controls. The peaks of N-acetylaspartate (NAA), choline (Cho), myoinositol (mI), lactate, and lipids were considered, and the results were expressed using creatine as reference. Spectra of PML lesions were characterised by significantly reduced NAA, lactate presence, and by significantly increased Cho and lipids compared with control group values. These results indicate that 1H-MRS detects a homogenous pattern in PML lesions. Recent studies, together with this, suggest that 1H-MRS may help in the diagnostic approach to patients with suspected PML lesions associated with AIDS.

AIDS Dementia Complex↗
PubMed1999

Effects of endurance training on skeletal muscle bioenergetics in chronic obstructive pulmonary disease.

Physiologic adaptations after an 8-wk endurance training program were examined in 13 patients with chronic obstructive pulmonary disease (COPD) (age, 64 +/- 4 [SD] yr; FEV1, 43 +/- 9% pred; PaO2, 72 +/- 8 mm Hg; and PaCO2, 36 +/- 2 mm Hg) and in eight healthy sedentary control subjects (61 +/- 4 yr). Both pre- and post-training studies included: (1) whole-body oxygen consumption (V O2) and one-leg O2 uptake (V O2leg) during exercise; and (2) intracellular pH (pHi) and inorganic phosphate to phosphocreatine ratio ([Pi]/[PCr]) during exercise; and half-time of [PCr] recovery. After training, the two groups increased peak V O2 (p < 0.05 each) and showed a similar fall in submaximal femoral venous lactate levels (p < 0.05 each). However, control subjects increased peak V E (p < 0.01) and raised peak O2 delivery (p = 0.05), not shown in patients with COPD. Both groups increased post-training O2 extraction ratio (p < 0.05). The most consistent finding, however, was in patients with COPD, who had a substantial improvement in cellular bioenergetics: (1) half-time of [PCr] recovery fell from 50 +/- 8 to 34 +/- 7 s (p = 0.02); and (2) at a given submaximal work rate, [Pi]/[PCr] ratio decreased and pHi increased (p < 0.05 each). We conclude that beneficial effects of training in patients with COPD essentially occurred at muscle level during submaximal exercise.

Aged↗
PubMed1999

Discovery of new antimalarial compounds by use of molecular connectivity techniques.

Molecular connectivity has been applied to the search for new compounds with antimalarial activity. Linear discriminant analysis and connectivity functions were used to select several potentially suitable drugs which were tested for antimalarial properties by use of an in-vitro micro test which estimates parasite growth by measurement of incorporation of [3H]hypoxanthine. Hexetidine stands out among the compounds selected. Activity assays were performed with Plasmodium falciparum passou and 3CD7 strains, for which the IC50 values (doses resulting in 50% inhibition) were 320 and 400 ng mL(-1), respectively. These results are comparable with those obtained for quinine chlorhydrate (IC50 = 60 and 107.8 ng mL(-1)) and chloroquine sulphate (IC50 = 231 and 415 ng mL(-1)), the drugs used for reference. These results demonstrate the usefulness of our topological approach for the selection and design of new lead drugs active against Plasmodium falciparum.

Animals↗
PubMed1999

[Gastrointestinal anisakiasis. Seven cases in three months].

Human anisakiasis or anisakidosis is an unusual parasitation. During the autumn of 1996 seven patients came to our Hospital for such a condition. Five of these patients had the parasites in the gastroduodenal area (1 in the gastric body, 3 in the antrum and 1 in the duodenal bulb, this one with two parasites). Four out of the five patients consulted us for intense epigastric pain; only one developed a cutaneous rash. The fifth patient was diagnosed unexpectedly during an endoscopy appointment. Eosinophilia was detected in none. All the parasites were extracted endoscopically and identified as belonging to the Anisakis genera. Excepting for the patient with no complaint, the other four showed adhered larvas to mucosa. The two other patients were operated because of acute abdominal pain. At laparotomy an ileitis was seen and then resected. Under microscopic examination both ileon were found to be edematous and infiltrated by eosinophils. Anisakis larvae were observed in the submucosa of one of the removed intestines. The other patient was diagnosed after an immunologic study consisting of radioimmunoassay and Western Blot. Five of the seven patients (71%) acquired the parasites after consumption of anchovies with vinegar.

Adult↗
PubMed1998

Effect of WEB 2086-BS, an antagonist of platelet-activating factor receptors, on retinal vascularity in diabetic rats.

Specific antagonists of platelet-activating factor (PAF) receptors inhibit platelet aggregation and thromboxane synthesis. These two processes have been implicated in the course of diabetic retinopathy. We assessed the effect of a specific PAF receptor antagonist, WEB 2086-BS (3-(4-(2-chlorophenyl)-9-methyl-6H-thieno(3,2-f) (1,2,4 triazolo-(4,3-a(1,4)-diazepine-2-yl)-1-(4-morpholinyl)-1-propanone) on retinal vascularity in a model of experimental streptozocin-induced diabetes in rats. Rats were divided into five experimental groups (10 animals/group): group I, non-diabetic group II, untreated diabetic group III, diabetic given 1 mg/kg per day of WEB 2086-BS (p.o.) group IV, diabetic given 5 mg/kg per day (p.o.) and group V, diabetic given 10 mg/kg per day (p.o.). After 3-month treatment, platelet aggregometry, platelet synthesis of thromboxane B2, aortic production of 6-keto-prostaglandin F1alpha, platelet and vascular lipid peroxidation, and percentage of the retinal area occupied by horseradish peroxidase-labeled vessels were measured. Untreated diabetic rats showed an increase in platelet reactivity, reduced 6-keto-prostaglandin F1alpha production, increased thromboxane B2 and lipid peroxides, and a decrease in the percentage of retinal area occupied by horseradish peroxidase-labeled vessels. WEB 2086-BS produced a decrease in platelet aggregation induced by collagen in whole blood, in thromboxane B2 synthesis and lipid peroxide production, and an increase in the percentage of retinal area occupied by horseradish peroxidase-labeled vessels (13.9+/-1.1% in group II and 9.9+/-0.8% in group V). There was a statistically significant linear correlation (Y= -0.72 + 137X, r2 = 0.7247, P < 0.0007) between thromboxane B2 values and the percentages of retinal area occupied by horseradish peroxidase-labeled vessels in the groups of animals treated with WEB 2086-BS.

Analysis of Variance↗
PubMed1998

Influence of human immunodeficiency virus 1 infection and degree of immunosuppression in the clinical characteristics and outcome of infective endocarditis in intravenous drug users.

BACKGROUND: Immunosuppression caused by human immunodeficiency virus 1 (HIV) infection appears to modify the clinical characteristics and to increase the severity of several bacterial infections. The impact of HIV infection and the degree of immunosuppression on the clinical characteristics and outcome of infective endocarditis (IE) in intravenous (IV) drug users has not been well characterized. METHODS: Prospective cohort study among 292 consecutive IV drug users with IE diagnosed in 2 academic institutional hospitals in Barcelona, Spain, from January 1, 1984, to October 31, 1995. Serostatus of HIV infection was documented in 283 patients. We measured demographics, clinical and biological data, cause, echocardiographic findings, HIV serostatus and classification, CD4 cell count, complications, and mortality. RESULTS: Among the 283 episodes of IE, 216 (76.3%) were in HIV-infected patients and 67 (23.7%) in non-HIV-infected patients. Rate of IE per 1000 admissions ranged from 0.17 to 0.82 per year, peaking in 1989. Characteristics of IE independently associated with HIV infection were right-side involvement (odds ratio [OR], 7.6; 95% confidence interval [CI], 3.5-16.7), a micro-organism different from viridans streptococci (OR, 2.5; 95% CI, 1.1-5.9), duration of drug abuse longer than 5 years (OR, 5.0; 95% CI, 2.4-10.3), and white blood cell count of no more than 10 X 10(9)/L (OR, 2.2; 95% CI, 1.1-4.2). There were no significant differences in mortality due to IE according to HIV serostatus. Among the 216 patients with HIV infection, the variables independently associated with worse outcome were CD4 cell count lower than 0.200 x 10(9)/L and left-sided or mixed IE. CONCLUSIONS: Although there is a difference in clinical presentation in IE in IV drug users, outcome was similar according to their HIV status. However, among HIV-infected patients, severe immunosuppression and mixed or left-side valvular involvement were strong risk factors for mortality.

AIDS-Related Opportunistic Infections↗