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Biomedical subjects

L Molina

Publications and source records attributed to L Molina.

At least 91 records · Page 5Linked to original sources
PubMed1990

Study of megakaryocytic progenitors (CFU-MK) in human long-term bone marrow cultures (LTBMC): adjuvant effect of plasma from aplastic patients.

Human long-term bone marrow cultures (LTBMC) provide a very interesting tool for studying the events that are involved in stem cell commitment. At the present time, megakaryocyte (MK) progenitor cells have never been demonstrated in this system. In an effort to detect this cell lineage, we modified the culture medium by substituting fetal calf serum (FCS) and horse serum (HS) mix with human plasma obtained from treated aplastic leukemic patients. This plasma was harvested between days 15 and 21 following induction chemotherapy or conditioning regimen for autograft or allogeneic bone marrow transplantation. Using LTBMC, 17 normal marrows were cultivated for 11 weeks in Iscove's modified Dulbecco's medium containing either 20% human aplastic plasma or control FCS/HS mixture. In this plasma medium we observed the development of an adherent layer morphologically comparable to that observed with standard medium. We demonstrated presence of MK cells at all stages of maturation for 10 weeks and MK colony-forming cells (CFU-MK) for 11 weeks in the culture supernatants. An increased production of nonadherent cells and granulocyte-macrophage progenitors (CFU-GM) was also observed. LTBMC in aplastic plasma medium provide a new method for studying megakaryocytopoiesis, especially in human hematological diseases.

Adolescent↗
PubMed1989

Diluted epinephrine solution for the treatment of priapism.

We report our experience with 18 consecutive cases of priapism treated with intracorporeal irrigations of dilute epinephrine solution. Of the 18 patients 16 were treated successfully. The 2 failures had priapism 36 hours and 5 days in duration, respectively.

Adult↗
PubMed1989

A prospective study of atrial fibrillation and stroke.

In a prospective study of 72 patients with stroke and atrial fibrillation, we classified strokes as cardioembolic or noncardioembolic based on arterial assessment using Doppler sonography and angiography. We analyzed and cross-tabulated 18 clinical characteristics and found four to be significantly associated with a cardioembolic mechanism: stroke with onset during activity and peak deficit at onset (p less than 0.008), previous infarct in a different vascular territory (p less than 0.01), previous transient ischemic attack in a different vascular territory (p less than 0.01), and transient ischemic attack lasting greater than 1 hour (p less than 0.02). Starting with these four characteristics, we used a step-down procedure to select variables for a logistic regression model. Only previous infarct in a different vascular territory (odds ratio = 7.38) and transient ischemic attack lasting greater than 1 hour (odds ratio = 7.89) were selected by the model. Using M-mode and two-dimensional echocardiography, we compared left atrial size in 46 patients with that in 78 controls who had atrial fibrillation without stroke. Left atrial size in patients and controls with mitral valvulopathy was significantly larger than that in patients and controls without mitral valve disease. There was, however, no difference in left atrial size between patients with nonvalvular atrial fibrillation and cardioembolic stroke and controls or patients with nonvalvular atrial fibrillation and noncardioembolic stroke. We concluded that some clinical characteristics are closely related to cardioembolic stroke and that left atrial enlargement reflects underlying cardiopathy rather than atrial emboli-forming capability.

Aged↗
PubMed1979

A combined testing protocol approach for mutagenicity testing.

The antischistosomal agent, hycanthone methanesulfonate (HMS), was employed to illustrate the utility of carrying out several mutagenicity tests in a single concurrent animal experiment. Several commonly used procedures that were successfully integrated into a multiple testing protocol included (1) metaphase analysis in bone marrow, (2) micronucleus test in bone marrow, (3) analysis of the urine for mutagenic constituents, and (4) the host-mediated assay using Salmonella typhimurium. In addition to these animal studies, in vitro mutagenicity testing with and without activation was carried out using S. typhimurium. HMS produced positive, dose--response effects in in vitro tests, metaphase analysis, micronucleus test, and urine analysis, but not in the host-mediated assay. The results of these integrated techniques suggest that such a protocol may be a benefit to those concerned with mutagenicity testing of chemicals.

Animals↗
PubMedDate not supplied

Calcified aldosterone-producing adrenocortical adenoma.

We report the first case of benign aldosteronoma of an ordinary size with calcifications. We review the clinical, clinical imaging, histopathological, and laboratory features of aldosterone-producing adrenal adenoma versus carcinoma. We conclude that no single feature is diagnostic, and the full range of data must be considered. Calcifications may not necessarily be a distinguishing point.

Adrenal Cortex↗
PubMedDate not supplied

Separation of non-ortho polychlorinated biphenyl congeners on pre-packed carbon tubes. Application to analysis in sewage sludge and soil samples.

The analysis of planar (non-ortho) polychlorinated biphenyls (PCB) by HRGC-ECD or HRGC-HRMS requires a fractionation step to avoid the interferences of the bulk of PCB, usually in much higher concentration than the planar ones. In this paper, a new method, based on the fractionation of PCB on SPE commercial tubes pre-packed with Carbopack B, has been developed. After the extract has been applied on the stationary phase, the bulk of PCD are eluted with 15 ml of hexane (fraction I), mono-ortho PCB with 20 ml of hexane/toluene 99:1 (fraction II) and planar PCB with 20 ml of toluene (fraction III) in a station under vacuum. The method has been validated: accuracy (expressed as recovery in %) is >70% and precision (expressed as % RSD) is <20% considering changes of day, analyst and batch of tubes. The method is linear in the range studied. Other advantages are that the method is simple, rapid and it can be easily automated. The application of this separation to the determination of planar PCB in fly-ash extracts from an intercalibration exercise and to sewage sludge, sediment and soil samples has been successful. In addition, this method removes hydrocarbons from the planar PCB fraction and allows its concentration to very small volumes.

Carbon↗
PubMedDate not supplied

Study of evolution of PCDD/F in sewage sludge-amended soils for land restoration purposes.

The evolution of polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) in sewage sludge-amended soils used in the restoration of degraded lands, like quarries, has been studied. Two experiments were performed: one in the lab, under controlled conditions, and another in a quarry. Two different doses of sewage sludge were applied in both experiments (with two types of application in the quarry experiment) and the evolution of the amended soils were compared with that of the respective control soils (without addition of sewage sludge). The samples were analyzed with a previously validated method by HRGC HRMS after the extraction and the necessary clean-up steps. The results reveal that polluted sewage sludge increases PCDD/F concentration in soils and that these compounds are persistent in the matrix after long periods of time.

Benzofurans↗
PubMedDate not supplied

Broad-spectrum determination of pesticides in groundwater by gas chromatography with electron capture detection, nitrogen-phosphorus detection, and tandem mass spectrometry.

Gas chromatography with electron capture detector (ECD), nitrogen-phosphorus detector (NPD), and tandem mass spectrometry (MS/MS) was used to identify 36 pesticides, widely used to control various pest and diseases in vegetables, in water after a preconcentration step on C18 cartridges. The recoveries obtained ranged from 70 to 135% at a fortification level of 100 ng/L with relative standard deviations of <36.2%. The limits of detection and quantitation were < or =48 and < or =160 ng/L, respectively. Important advantages of MS/MS over ECD and NPD in the determination of pesticides are also presented. The proposed analytical methodology was applied to the determination of pesticides in groundwater samples from an agricultural area, the Campo de Dalías (Almería, Spain). The most frequently encountered pesticides were endosulfan sulfate and metalaxyl, whereas the pesticide found at the highest concentration was fenamiphos.

Alanine↗
PubMedDate not supplied

[Thyroid dysfunction induced by amiodarone].

Amiodarone (2-n-butyl-3,4-diethylaminoethoxy-3',-diiodobenzoyl-benzofurone ) is a drug widely used for the treatment of cardiac arrhythmias. Due to its high iodine content and structural similarity to thyroxine it produces abnormalities in thyroid hormone metabolism and, in some cases, clinical thyroid dysfunction as well. We report 18 patients, 11 females and 7 males, whose thyroid disease developed during treatment with amiodarone (A). Age ranged from 13 to 64 years. A history of thyroid disease in a first-degree relative was present in five, and three patients had goiter prior to A therapy. Fifteen patients had atrial arrhythmias, and 3 had ventricular arrhythmias. Amiodarone was being given in doses of 200 to 800 mg daily. Thyroid function abnormalities appeared between 1 and 29 months after starting A therapy. Nine patients became clinically and chemically thyrotoxic; three patients developed diffuse thyroid enlargement and had total T4 concentration and FI4I increased with normal T3 and no signs of hyperthyroidism; and the six remaining patients became clinically hypothyroid with low values of total T4 and FTI and raised basal TSH. No relationship between dosages of A or duration of treatment and the appearance or severity of thyroid dysfunction was found. Regression of symptoms occurred in all but two patients with simple goiter between 1 and 8 months after amiodarone was discontinued and appropriate treatment was given. Our observations confirm the potential of A to induce thyroid abnormalities in patients with and without preexistent thyroid disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

[Clinical electrophysiological evaluation of mexiletine].

We studied sixteen patients (pts), seven men and nine women (mean age 35 years) with sustained tachyarrhythmias, for acute therapeutic trial with mexiletine (3 mg/kg IV). The arrhythmias were: ventricular tachyarrhythmia in eight pts supra-ventricular tachycardia (SVT) in eight pts, seven due to abnormal tracts (43%) and one to nodal reentry. After mexiletine administration, the sinusal cycle length was reduced in 12.7% (P less than 0.05) and the H-V interval decreased 6.1% (P less than 0.05). The nodal conduction (A-H) didn't show any substantial change, neither the atrial nor the ventricular refractory periods (RP). In two pts with complex premature ventricular beats it was not possible to induce the ventricular tachycardia(VT) six had sustained VT. After mexiletine administration, three of them (37.5%) showed self limited VT with a greater R-R cycle. Another case was complicated by ventricular fibrillation, In the pts with SVT, the retrograde RP of the abnormal tracts shortened in 27% (P less than 0.05), while the antegrade was not modified. Mexiletine showed to be efficient for the VT treatment. Its efficacy was very limited in pts with SVT. There was no evidence of any deleterious effect over the His-Purkinje conduction.

Adolescent↗
PubMedDate not supplied

[Use of the subclavian vein for permanent cardiac stimulation].

The experience on 101 cases of permanent cardiac stimulation is reported; in all of them, the access was via the subclavian vein. Punction of the subclavian artery, transient injury of the brachial plexus and pneumothorax, were seen in 4.3 and 3% respectively. Early electrode luxation was observed in 5% of the patients. As late complications there where two cases of destruction of the electrode protecting sheet and one electrode rupture. In spite of the potential risks directly related to the vein puncture, the subclavian puncture offers an excellent alternative for placing definitive pacing electrodes.

Adult↗
PubMedDate not supplied

[Autoimmunity in thyroid disease secondary to amiodarone: heredofamilial aspects].

Spontaneous autoimmune thyroid disease (SATD) shows familial aggregation. Some patients receiving amiodarone treatment have been found to develop thyroid dysfunction. Previously, we reported genetic predisposition among this group of patients, now we inform a prospective study which includes the search for autoantibodies and family history to identify risk factors in amiodarone treated patients, 40 of them with amiodarone related thyroid disfunction, and 100 without it; for comparison, 30 patients with SATD and a control group of healthy subjects were also studied. We looked for the presence of autoantibodies against thyroglobulin, smooth muscle, gastric mucosa, myocardium, mitochondria, epithelial intercellular substance, and basal membrane as well as antinuclear antibodies and rheumatoid factors; in addition the history of thyroid disease in first degree relatives was investigated. Organ-specific antibodies anti-thyroglobulin, gastric mucosa and myocardium were found with increased frequency in the three groups of patients compared with controls (p less than 0.05). The frequency of antihydroglobulin antibodies was similar in patients receiving amiodarone with or without thyroid dysfunction. Prognostic stratification revealed that this finding is independent of sex, age, dosage or duration of treatment. A family history of thyroid dysfunction was found more frequently among patients with SATD and amiodarone related dysthyroidism in comparison with patients receiving amiodarone without altered thyroid function (p less than 0.005). The appearance of clinical thyroid disease depends on individual genetical predisposition. In patients with a positive family history, the risk of developing clinical, thyroid disease is 7.6 when treated with amiodarone.

Adolescent↗