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Biomedical subjects

I García

Publications and source records attributed to I García.

At least 199 records · Page 11Linked to original sources
PubMedDate not supplied

L-usnate-urease interactions: binding sites for the ligand.

L-usnic acid inactivates urease by formation of high molecular weight aggregates which can reached by a maximum of 880 000. L-cysteine partially reverses the inactivation of stimulating the appearance of active high molecular weight polymers. The existence of two class of binding points for L-usnic acid on the urease molecule is proposed, the first showing high affinity for the ligand, related with the loss of activity, and the second, of low affinity, related to polymerization process.

Benzofurans↗
PubMedDate not supplied

L-usnate-urease interactions: binding sites for polymerization.

L-usnic acid inactivates urease through a process which implicates the blockade of--SH groups in parallel to the formation of inactive polymers. Both L-alanine and L-proline partially reverses the inactivation and effectively diminishes the amount of highly polymerized protein. The amino acids also prevent the linkage of L-usnic acid on the sites of low affinity for the ligand, being then related to the sites of polymerization.

Alanine↗
PubMedDate not supplied

Migration of trace elements from pyrite tailings in carbonate soils.

In the carbonate soils contaminated by a toxic spill from a pyrite mine (Aznalcóllar, southern Spain), a study was made of a thin layer (thickness = 4 mm) of polluted soil located between the pyrite tailings and the underlying soil. This layer, reddish-yellow in color due to a high Fe content, formed when sulfates (from the oxidation of sulfides) infiltrated the soil, causing acidification (to pH 5.6 as opposed to 8.0 of unaffected soil) and pollution (in Zn, Cu, As, Pb, Co, Cd, Sb, Bi, Tl, and In). The less mobile elements (As, Bi, In, Pb, Sb, and Tl) concentrated in the uppermost part of the reddish-yellow layer, with concentration decreasing downward. The more mobile elements (Co, Cd, Zn, and Cu) tended to precipitate where the pH was basic, toward the bottom of the layer or in the upper part of the underlying soil. The greatest accumulations occurred within the first 6 mm in overall soil depth, and were negligible below 15 mm. In addition, the acidity of the solution from the tailings degraded the minerals of the clay fraction of the soils, both the phyllosilicates as well as the carbonates. Also, within the reddish-yellow layer, gypsum formed autigenically, together with complex salts of sulfates of Fe, Al, Zn, Ca, and Mn, jarosite, and oxihydroxides of Fe.

Hazardous Substances↗
PubMedDate not supplied

[Bioelectric impedance in the nutritional evaluation of mentally deficient quadriplegic adults].

Severely mentally retarded persons with cerebral palsy show a high rate of acute and chronic malnutrition. Without discarging other factors which might be at play, caloric intake deficiency stemming from the difficulties involved in being fed appear to play a crucial role in its etiology. In the assessment of these disorders, anthropometry is limited by the lack of adequate reference values and by the difficulty or impossibility of measuring height using the conventional method. The purpose of this study is to see how changes in body composition brought about by an increase in dietary caloric intake are perceived by both anthropometry and biolectrical impedance analysis. To do so, 13 subjects were selected from a group of 203 severely mentally retarded persons made up of 25% cerebral palsy patients and 13% quadriplegics. The 13 subjects were fed orally without tubes and all had tricipital skinfolds of less than P25. All 13 were given a 25% caloric increase over the regular diets for a period of two months. This increase was provided by means of a polymeric, normoproteic, hypercaloric preparation. Weight and brachial perimeter showed significant increases coinciding with the administration of the supplement. Theses increases were not noticeable two months after discontinuing the supplement. There were no significant changes in tricipital and subescapular skinfolds, muscular circumference of de mid-arm, resistance, reactance, or the total body an extracellular water calculated from the latter two values. From these results we deduce that biolectrical impedance analisys offers no advantages over anthropometry in monitoring the nutritional status of quadriplegics.

Adult↗
PubMedDate not supplied

[A multidisciplinary approach to the management of cerebral vascular malformations].

INTRODUCTION: Cerebral vascular malformations (CVM) are a heterogeneous group of lesions. One way of classifying them is according to histological criteria, clinical features, imaging findings, electroencephalography and distinctive pathology. OBJECTIVES: To report the results obtained in 16 patients clinically diagnosed as having CVM and operated on in the Centro Internacional de Restauración Neurológica (La Habana, Cuba) between March 1995 and October 1998. We also consider the usefulness of diagnostic tools for neurosurgical management and anatomo-pathological diagnosis. PATIENTS AND METHODS: We review the clinical findings, images, electroencephalograms and diagnostic histology of 16 patients. The gender distribution was 10 men and 6 women who were aged between 9 and 48 years. Stereotaxic resection guided by CAT and angiography was done in all cases. RESULTS: The predominant symptoms were headache and generalized tonic-clonic convulsions. CAT and angiography were helpful in determining the clinical diagnosis and location. The most frequent electroencephalographic finding was focal slowing associated with inactive epileptiform disorders. Histological study showed that there were 3 cases of arteriovenous malformations (AVM), one angioma cavernosa and one mixed vascular malformation (AVM plus angioma cavernosa). The malformation was not resected (it was treated with a clip) in the remaining case. CONCLUSION: Our results show the importance of structural imaging studies and their relationship to functional studies in the presumptive diagnosis of CVM corroborated by post-operative histological diagnosis.

Adolescent↗
PubMedDate not supplied

Relationship of tumoral hyaluronic acid and cathepsin D contents with histological type of gastric carcinoma.

The aim of this work was to evaluate the cytosolic contents of hyaluronic acid (HA) and cathepsin D (CatD) in gastric carcinomas and their possible relationships with the clinicopathological parameters of the tumors. Our study demonstrated a wide variability in the cytosolic levels of HA (mean +/- SEM: 3748 +/- 411 ng/mg protein) and cathepsin D (52 +/- 4 pmol/mg protein) in the tumors of 78 gastric cancer patients. In addition, the tumoral contents of HA and CatD were significantly higher (p<0.005) in diffuse type (HA: 6027 +/- 1099 ng/mg protein; CatD: 75 +/- 13 pmol/mg protein) than in intestinal type (HA: 2735 +/- 242 ng/mg protein; CatD: 42 +/- 3 pmol/mg protein) carcinomas. These data suggest that both markers may contribute to the biological characterization of gastric carcinomas.

Adult↗
PubMedDate not supplied

Descending necrotizing mediastinitis.

Between 1990-1999, six patients (mean age, 41.5 years) with the diagnosis of descending necrotizing mediastinitis were surgically treated at our institution. All patients underwent cervical drainage plus an aggressive mediastinal debridement and drainage via posterolateral thoracotomy. The outcome was favorable in all cases. All patients received initially a high dose of broad-spectrum antibiotics. In four patients, a tracheostomy was necessary for respiratory management. We also review the literature.

Acute Disease↗
PubMedDate not supplied

Liver transplantation and hepatitis C virus. Results in a Spanish center since 1989.

BACKGROUND/AIMS: Hepatitis C-related liver disease is the main indication for liver transplantation in many centers. Viral RNA remains after transplantation in almost 100% of the patients, and more recent reports show a graft hepatitis rate of about 90%. The progression of this hepatitis seems to be quicker than in the nontransplant setting. METHODOLOGY: From June 1989 to October 2000, 197 adult patients had 213 for HCV-related liver disease at our institution. Basal immunosuppression consisted of a triple therapy with cyclosporine, azathioprine and steroids, or dual therapy with tacrolimus and steroids. None of the patients was treated with antivirals after liver transplantation. RESULTS: Pure HCV-related cirrhosis was the indication for liver transplantation in 114 patients, another 14 with hepatocellular carcinoma, 8 associated metabolic diseases, 43 high alcohol intake, 4 hepatitis B, 5 cholestatic diseases, and 3 other diseases. Six patients out of the 197 transplanted in this period were already grafted before this time, and had their first retransplantation of the liver after 1989 (their first liver transplantation was done when HCV was not known). Sixteen additional retransplantation procedures were done in the period considered. Hepatitis was diagnosed in 84.3% of the grafts biopsied later than 90 days after liver transplantation (118/140), and in 92.9% if it was done after one year (92/99). Cirrhosis was diagnosed in 21 grafts at a mean time of 1004.7 days, 21.2% of the grafts biopsied after 1 year and 28.6% after 2 years. Nine grafts in 8 patients were diagnosed as fibrosing cholestatic hepatitis. Patient actuarial survival was 80.9%, 69.7%, 67.5% and 50.6% at 1, 3, 5 and 10 years. Liver failure and hepatoma recurrence were the cause of death in 42.4% of the patients. Actuarial graft survival was 75.2%, 64.9%, 63.5% and 48.6% at 1, 3, 5 and 10 years, and was significantly affected by Child stage (B vs. C, P = 0.004). When compared to 228 non-HCV- infected patients with chronic parenchymatous disease, these had an almost significantly better patient survival (P = 0.0577), but a nonsignificant difference in graft survival. Graft loss related to liver causes was 17.6% in HCV+ patients 14.6% in HCV- patients. Liver causes of death were 14.0% in HCV+ patients and 4.8% in HCV-patients (P = 0.002). CONCLUSIONS: HCV infected liver transplantation recipients present very often graft hepatitis, which may progress to advanced stages in a quite short interval. Mid-term patient and graft survival is comparable to those of non-HCV recipients, but causes of death related directly to liver disease are more common in HCV+. This makes one think that long-term prognosis (more than 10 or 15 years) will be worse in HCV patients.

Actuarial Analysis↗
PubMedDate not supplied

[Migraine and MIDAS (MIDASELA) in Colombian hospital workers].

AIMS: The aim of this study was to determine the prevalence of migraine and its implications in the occupational and outside employment/daily activities of the workers at a regional hospital in the Cundiboyacense Plateau in Colombia. PATIENTS AND METHODS: The available members of the house staff at this institution were interviewed by applying the neuroepidemiological protocol drawn up by the World Health Organization (WHO); general doctors performed the initial screening and the determination of neurological disease was carried out by a clinical neurologist, both in patients who were positive and negative for neurological disease. Quality of life was evaluated by means of the MIDAS (Migraine Disability Assessment) survey, MIDASELA (in Spanish for Latin America); the analysis was performed using the EPI 6.04 software application. RESULTS: A total of 238 people were studied: 188 females and 50 males; the prevalence of migraine was 22.5% (15.5% by the WHO protocol and 7% false negatives), with predominance in females (OR: 5.49; p< 0.005). In the MIDASELA questionnaire, 47.2% of the patients had a 50% alteration in their productivity, with regard to their occupational and outside employment/daily activities. A minimum number of patients (3.8%) were unable to work because of migraine, as compared to the figures for outside employment/daily activities (29.7%) or those involving leisure/family (66.4%). The average work, outside employment/daily and family time lost per patient because of migraine was 0.3, 2 and 5.2 days, respectively. CONCLUSION: A sub register in the prevalence of migraine could be reported in places where the WHO protocol is used. This pathology will have to be taken well into account in Colombian hospital workers due to its individual, occupational, family, social and economic impact. It is necessary to introduce health policies and programmes aimed at evaluating, controlling and treating this type of pathology in an appropriate manner, in order to improve the quality of life of those whose job it is to look after and improve that of the other Colombians.

Adult↗
PubMedDate not supplied

[A comparative study of cisapride versus metoclopramide in the treatment of symptomatic hiatal hernia].

Comparative study of the therapeutical effects of cisapride and metoclopramide in 50 patients with symptomatic hiatal hernia was performed. Behaviour of media before and after treatment, of resting pressure and relaxation lower esophageal sphincter, pressure of the primary wave and the number of reflux episodes with pH < 4. The group of patients treated with cisapride had a considerably higher beneficial effect (p < 0.01) than the metoclopramide-treated group. A total of 4 patients were dropped-off the study because of undesirable side effects (diarrhea 2, headache 1, and somnolence 1).

Adolescent↗
PubMedDate not supplied

[Isolation of aspartic proteinases at different stages of development of Boophilus microplus tick].

The magnitud of tisular expression of aspartic proteinases at juvenile stages was analyzed in adult young Boophilus microplus ticks as well as the effect of one of the most widely used aspartic proteinase inhibitors (pepstatin A) on their development. The isolation and quantification of acid proteolytic activity was performed in samples of parasites with different stages of the digestive process where aspartic-proteinase activity was confirmed and a tendency to increased values of enzymatic activity per miligram of total weight was observed during the development of adults female ticks, with a lowering of this ratio just when they are full up. Adding pepstatin A to the ingesta at 14 and 70 mmol concentrations had no effect on the viability of young female ticks while they were kept in vitro for 24 h, so this rules out the immediate toxic effects of this compound. However, in those experiments where adult female ticks after receiving the various ingestas, are put together with sexually competent male ticks in isolators for 6-7 days, the viability showed different results (p< 0,01) at a 70 mmol concentration. The effect on the development of young adult female ticks was slight, but it indicates hat there might be a selective inhibitory action of pepstatin A on aspartic-dependent enzymes.

Animals↗
PubMedDate not supplied

Esophageal resection through a translaparotomic-transcervical approach.

The authors present their experience obtained from January/78 to March/90 with transhiatal esophagectomy. Two hundred and eighty-nine patients were operated on using this procedure; 171 of them underwent the operation for cancer of the esophagus, 76 for cancer of the cardia, 11 for cancer of the hypopharynx, and 31 for benign conditions. The esophageal replacement was made with stomach in 63.6% of the cases, ileo-ceco-coloplasty in 28.5%, left colon in 7.6%, jejunum in 0.3%. Cancer patients were mainly in advanced stages (stage III in 67.3% of esophageal cancer, and in 69.7% of cardial cancer). Average blood requirements for the different diseases ranged between 500 and 1,100 cc. Only 16 patients required admission in the ICU. Mean hospital stay ranged from 16.7 to 20.6 days. Surgical complications were hemorrhage (0.3%), and tracheal injury (0.6%). Overall operative mortality (at 30 days) was 5.8%, as a result of respiratory insufficiency (35.2%), pulmonary sepsis (17.8%), and others (23.5%). Long term survival at five years was 11.8% for cancer of the esophagus, 48.5% for cancer of the cardia, and 57.1% for cancer of the hypopharynx.

Adolescent↗
PubMedDate not supplied

[Nephrogenic adenoma: presentation of a case and review of the literature].

We report a case of nephrogenic adenoma in a patient who had previously undergone a nephrectomy procedure for renal TB, and with a history of recurrent infection of the urinary tract. The present case shows the role of chronic inflammatory disease in the pathogenesis of nephrogenic adenoma.

Adenoma↗
PubMedDate not supplied

[Diagnostic laparotomy in the child under 12 with Hodgkin's disease].

Twenty-eight children with Hodgkin's disease were followed between 1971 to 1978. Patients were grouped at diagnosis by clinical staging (C.S.) I and II (60%) and III and IV (40%). All patients were laparotomized and splenectomized and multiple node gland biopsy were taken in order to classify them in anatomopathological stages (A.P.S.) and to administer treatment according to a local protocol. No surgical complications were seen and in 10 patients (36%), infiltration of spleen, lymph nodes and other organs were found at surgery which changed their initial clinical stage to a more advanced stage. Then patients (36%) presented 12 episodes of viral infections, during the first years after splenectomy, and 9 bacterial infectious complications mainly between 2 to 4 years after surgery. All patients with A.P.S. I and II are alive and in complete remission, without treatment and with a mean survival time (M.S.T.) of 32 months. M.S.T. in patients with A.P.S. III A has been 63 months and two out of six have died from tumor dissemination and septicemia. M.S.T. in patients A.P.S. III B and IV has been 57 months and 3 out of 11 have died all from dissemination of their disease. Dissemination of the disease, splenectomy and immunologic depression from therapy are important factors to be evaluated when laparotomy is performed in children with Hodgkin's disease.

Child↗