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V Rodríguez

Publications and source records attributed to V Rodríguez.

52 records · Page 3Linked to original sources
PubMed1989

Effect of pinealectomy and of diabetes on liver insulin and glucagon receptor concentrations in the rat.

The studies described in this paper were undertaken to characterize the circulating and hepatic insulin and glucagon receptor concentrations of control (C), diabetic (Db), and pinealectomized-diabetic (Pn + Db) rats. Compared with C rats, an increase in plasma glucose and glucagon levels and a reduction in circulating insulin concentrations in Db animals was observed; these differences were greater in Pn + Db rats. In liver membranes, insulin binding was lower in Db and in Pn + Db than in C rats, and glucagon binding was greater in Db and in Pn + Db than in C rats. The modifications in hormone binding did not reflect changes in the affinity constants. The time courses of hormone association and dissociation from liver membranes were similar in all three experimental groups. The degradation of both hormones and their receptors was similar in all three groups. These findings indicate that in either pinealectomized-diabetic or diabetic rats there were significant changes in the circulating and liver insulin and glucagon receptor concentrations and that the changes in the circulating levels of both pancreatic hormones were more pronounced in pinealectomized-diabetic animals. In addition, the absence in Db and in Pn + Db rats of the insulin and glucagon down-regulation of their own receptors could further modify metabolic activities in these animals.

Animals↗
PubMed1989

[Use of aspirin in the primary prevention of vascular thrombi. A comparative study with other anti-aggregant drugs].

We have induced the formation of arterial (carotid) and venous (femoral) thrombi in dogs by means of an intima lesion produced by continuous current. The platelets were labeled with 111In oxine. Groups of 7 mongrel dogs received treatment for 7 days prior to the trial: group I, control; group II, 5 mg/kg body weight/day acetylsalicylic acid; group III, 20 mg/kg body weight/day acetylsalicylic acid; group IV, 15 mg/kg body weight/day triflusal + 5 mg/kg body weight/day dipyridamole; group V, 15 mg/kg body weight/day triflusal; and group VI, 5 mg/kg body weight/day acetylsalicylic acid + 5 mg/kg body weight/day dipyridamole. The only effective treatment for arterial thrombosis prevention was that employed in group II (p less than 0.05). Venous thrombosis was prevented in groups II (p less than 0.01), III (p less than 0.01) and VI (p less than 0.01).

Animals↗
PubMed1989

[Hernial strangulation of Meckel's diverticulum: Littre's hernia. Apropos of 4 cases].

Hernial strangulation of Meckel's diverticulum (Littre's hernia) is a rare anatomoclinical form. It represents 10% of all complications of Meckel's diverticulum (8.8% of our cases), and complications like hemorrhage, perforation and diverticulitis are fairly frequent. Four cases of Littre's hernia are presented: two males and two females, with an average age of 67 years (range 50-83 years), representing 0.08% of all the inguinal-crural hernias operated in the department. The clinical manifestations were those of intestinal obstruction because a mixed type Littre's hernia was involved, with compromise of the diverticulum and its intestinal loop. Preoperative diagnosis is unlikely in strangulation without disturbances in the intestinal transit and, in fact, is even less likely if it is accompanied by obstruction. The diagnosis is thus almost always intraoperative. The correct treatment is surgery after restoring the patient's hemodynamic equilibrium. Simple and/or loop diverticulectomy via herniotomy, herniolaparotomy or laparotomy are debated. We think that this disorder can generally be resolved using the inguinal approach, as in any strangled hernia, with the technical option of using a larger, more comfortable and safer approach in cases of important obesity and/or deterioration of the loop (necrosis, perforation). In elderly patients with uncomplicated Littre's hernia and Meckel's diverticulum, abstention from diverticular exeresis may be justifiable. Of the four patients, the first two died from cardiogenic shock and pulmonary embolism, respectively; the last two evolved well (except for a wound abscess).

Aged↗
PubMed1987

Coagulation defects during extracorporeal circulation in the dog.

This study was undertaken in an attempt to diminish the frequency and severity of postextracorporeal circulation hemorrhage in dogs. Its purpose is to ascertain the amount of 99mTc-labeled autologous fibrinogen deposited in the oxygenator, as well as the coagulation defect originated during the surgical procedure when heparin is not administered (group I) and when it is at doses of 1 mg/kg body weight (group II) and 3 mg/kg body weight (group III). The result demonstrate that the fibrinogen deposition in the oxygenator decreased as the dose of heparin administered was augmented. The coagulation disorders were produced by factor consumption, affecting all dogs in group I. The same type of alteration was produced with the use of heparin, but in some the platelet count, fibrinogen and fibrinogen degradation products and the prothrombin and thrombin times were maintained within normality or were only slightly altered. Significant differences were not detected between groups II and III. For this reason, we recommend the utilization of heparin in experimental extracorporeal circulation in a single dose of 1 mg/kg body weight, administered at the initiation of bypass, which provides a sufficient level of anticoagulation for at least 60 min and makes its neutralization with protamine unnecessary, the effects of which are especially adverse in the dog.

Animals↗
PubMed1985

Return to ovulation following the use of long-acting injectable contraceptives: a comparative study.

A comparative study was undertaken in twenty-four Mexican women who discontinued the use of depo-medroxyprogesterone acetate (DMPA) or norethisterone enanthate (NET-EN) to assess the time required for the return to menses and ovulation. All subjects were exposed to long-acting injectable contraceptives for at least one year, and were followed prospectively. Serum progesterone levels were determined weekly in all subjects beginning 3 months after the last progestogen injection. Mean time to return to ovulation occurred significantly earlier (p less than 0.001) after NET-EN (2.6 months) as compared with DMPA (5.5 months). No correlation between the return to ovarian function and the duration of steroid exposure was found. The overall data was interpreted as demonstrating a clear-cut difference between the two long-acting progestogens in terms of ovulation suppression.

Adult↗
PubMed1985

[Family interactions and adherence to lithium pharmacotherapy].

A random sample of thirty families containing a member with a bipolar disorder were interviewed by a psychiatrist and two clinical psychologists with training in family evaluations and therapy. During the interview the family was given the task of discussing the possible causes of the patient's illness and to consider specific steps to help prevent relapses. The raters independently scored the Beavers Timberlawn Family Evaluation Scale and the Family Response to the Illness Scale. The patients were also evaluated using the Social Support Network Inventory, and a number of clinical and demographic indicators were routinely recorded. The research team showed good interrater reliability with the instruments, and evidence of validity is presented for the FRIS. A Cluster Analysis was performed and a two clusters solution was found. The first cluster contained twelve patients and the second is composed of eighteen patients. The clusters seem to differentiate patients along clinical outcome measures, drug compliance and cultural background. Family variables related to the structural dimensions of the system were found to cut across both clusters. Family variables measuring empathy, affect and expression of feelings were found to predict medication compliance and clinical outcome. The findings are discussed in the light of the concept of underorganization of family structures.

Bipolar Disorder↗
PubMedDate not supplied

Canine visceral leishmaniasis on Margarita Island (Nueva Esparta, Venezuela).

The frequency of American visceral leishmaniasis affecting humans on Margarita Island, Venezuela, has increased in recent years, and infected dogs appear to constitute the principal source of infection. ELISA tests with Leishmania donovani promastigotes and rK39 antigen from L. chagasi in serum from 541 dogs were positive in 33.1% and 21.6% of the samples, respectively. A second blood sample taken from 50 animals after 8-10 months revealed an increase from 24% to 40% of ELISA positivity to both antigens, suggesting high susceptibility and transmission in the canine population. Among 42 serologically positive dogs, 33% of which showed clinical signs of disease, 79% were positive in polymerase chain reactions using primers specific for the L. donovani complex. Control measures including epidemiological hypersurveillance, the humane sacrifice of infected dogs, and rapid diagnosis and treatment of human cases have been initiated.

Animals↗
PubMedDate not supplied

[The EMECAM protocol: an analysis of the short-term effect of air pollution on mortality. Estudio Multicéntrico Español sobre la Relación entre la Contaminación Atmosférica u la Mortalidad].

The aim of this study is to Mortality show the protocol of analysis which was set out as part of the EMECAM Project, illustrating the application thereof to the effect of pollution has on the mortality in the city of Valencia. The response variables considered will be the daily deaths rate resulting from all causes, except external ones. The explicative variables are the daily series of different pollutants (black smoke, SO2, NO2, CO, O3). As possible confusion variables, weather factors, structural factors and weekly cases of flu are taken into account. A Poisson regression model is built up for each one of the four deaths series in two stages. In the first stage, a baseline model is fitted using the possible confusion variables. In the second stage, the pollution variables or the time legs thereof are included, controlling the residual autocorrelation by including mortality time lags. The process of fitting the baseline model is as follows: 1) Include the significant sinusoidal terms up to the sixth order. 2) Include the significant temperature or temperature squared terms with the time lags thereof up to the 7th order. 3) Repeat this process with the relative humidity. 4) Add in the significant terms of calendar years, daily tendency and tendency squared. 5) The days of the week as dummy variables are always included in the model. 6) Include the holidays and the significant time lags of up to two weeks of flu. Following the reassessment of the model, each one of the pollutants and the time lags thereof up to the fifth order are proven out. The impact is analyzed by six-month periods, including interaction terms.

Air Pollution↗
PubMedDate not supplied

[Clinical and epidemiologic analysis of intestinal tract colonization with vancomycin-resistant enterococci in an intensive care unit].

Intestinal tract colonization with vancomycin resistant enterococci (VRE) was studied during five months and 25 days. Out of 171 patients hospitalized in the intensive care unit, 124 (73%) were included in this study. Thirty five of them (28%) were recognized as colonized with VRE. VRE isolates (n = 35) were identified as Enterococcus faecium (n = 18), Enterococcus gallinarum (n = 16), and Enterococcus raffinosus (n = 1). All of them were resistant to vancomycin (MIC90 = 512 microg/ml) and to teicoplanin (MIC90 = 32 microg/ml), having the vanA gene. By means of molecular methods a high homology was found among E. faecium and E. gallinarum isolates, respectively, suggesting their spread as a kind of outbreak. No significant differences in age or sex were found among colonized and non-colonized patients (p > 0.05). On the other hand, the hospitalization time and the use of broad-spectrum antibiotics were associated with colonization. From this study we highlight the importance of enhancing all measures of control and prevention of hospital infections, carefully analyzing the empiric antimicrobial schemes, trying to reduce the hospital stage, and following the surveillance to evaluate the efficacy of such procedures.

Adolescent↗
PubMedDate not supplied

[Thrombosis from prosthetic materials: prevention with different antiaggregatory agents. Low dose aspirin?].

Using an ex vivo shunt in dogs, platelet deposition on 6 prosthetic materials used in the construction of cardiovascular prostheses [highly porous Knitted Dacron (intervascular HP 800, 1,400 ml/cm2/min/120 mmHg), Woven Dacron of low porosity (intervascular LP 200, 200 ml/cm2/min/120 mmHg), Doble Velour Knitted Dacron, Avcothane 51 elastomere and the mesothelial and epipericardial surfaces of bovine pericardium] was quantified. The study of the prevention of platelet thrombi formation on these materials was carried out in 6 groups of 8 animals: group 1 (control), group 2 (5 mg/kg body weight/day acetylsalicylic acid), group 3 (20 mg/kg body weight/day acetylsalicylic acid), group 4 (15 mg/kg body wt/day triflusal plus 5 mg/kg body wt/day dipyridamole), group 5 (15 mg/kg body wt/day triflusal) and group 6 (5 mg/kg body wt/day acetylsalicylic acid plus 5 mg/kg body wt/day dipyridamole). Platelets were labeled with 111In-oxine. The least thrombogenic material was Avcothane 51 elastomere. The only effective treatment for reduction of platelet deposition on the 6 materials was that used in group 2. The treatment used in group 3 only decreased the deposition of platelets on 3 of the 6 materials. The treatments employed in groups 4, 5 and 6 did not significantly diminish the deposition of platelets on any of the materials when compared with the control group. The platelet count was not modified in the animals in groups 2 and 4 while in the rest it decreased after the test.

Animals↗
PubMedDate not supplied

Effects of different doses of acetylsalicylic acid on platelet aggregation: an experimental study of prosthetic materials in dogs.

Laminar flow is the condition best suited to the study of platelet thrombi. This type of thrombus is predominant in arteries, in the tubes of cannulas used in artificial circulatory systems, in cardiac valve prostheses and in prosthetic arterial implants. Antiplatelet drugs could, in these cases, reduce the extent of thrombus formation. At present the optimal dose of acetylsalicylic acid (ASA) to achieve the best antithrombotic effect is unknown; some papers show that high doses augment experimental thrombosis. By means of autologous platelets labelled with 111In-oxine, we have quantified the accumulation on different materials used in cardiovascular surgery (woven, knitted and double velour Dacron, Avcothane 51 elastomere and smooth surface and rough surface pericardium). Samples of these fabrics were placed in a laminar flow chamber connected between the right atrium and femoral artery of the experimental animals (dogs). The animals were divided into four groups of eight dogs: Group I: no treatment Group II: animals treated one week earlier with ASA (1 mg/kg/day) Group III: as in Group II, but at a dose of 5 mg/kg/day Group IV: as in Group II, but at a dose of 20 mg/kg/day. The materials upon which the least amount of platelets were accumulated were the smooth, epicardial surface of pericardium (SP) and Avcothane (AV). The least deposition was produced in Group III, with the exception of SP. In the case of this material, there was no difference between Groups I and III. In Group IV, the deposit was greater with respect to the untreated group (Group I), except in the case of AV, in which there was no difference between Groups I and IV.

Animals↗
PubMedDate not supplied

Infraclavicular brachial plexus block effects on respiratory function and extent of the block.

BACKGROUND AND OBJECTIVES: Axillary block is devoid of severe respiratory complications. However, incomplete anesthesia of the upper limb is the main disadvantage of the technique. Theoretically, the more proximal infraclavicular approach would produce a more extensive block without the risk of pneumothorax. However, neither its effects on respiratory function nor a detailed characterization of the extent of neural block has been assessed. The goal of this study was to evaluate the possible changes in respiratory function and also the extent of the block after infraclavicular block. METHODS: We performed an infraclavicular block with a mixture of 40 mL 1.5% plain mepivacaine and 4 mL 8.4% sodium bicarbonate in 20 patients. Forced expiratory volumes were measured before and 15 minutes after the injection of local anesthetic, and sensory and motor block were evaluated at 10 and 20 minutes. RESULTS: We did not find significant differences from baseline in the forced expiratory volumes in any of the patients. Axillary and musculocutaneous nerve distributions had the lowest rate of sensory block at 20 minutes. CONCLUSIONS: Infraclavicular block does not produce a reduction in respiratory function.

Anesthetics, Local↗