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Biomedical subjects

R Diaz

Publications and source records attributed to R Diaz.

At least 73 records · Page 4Linked to original sources
PubMed1995

Acute myocardial infarction in the young--the role of smoking. The Investigators of the International Tissue Plasminogen Activator/Streptokinase Mortality Trial.

Patients who received thrombolytic therapy for acute myocardial infarction in a large international trial were divided into two groups on the basis of age; those < or = 40 years (n = 269) and those > 40 years (n = 7787). The younger group included more men (89.9% vs 75.9%, P = 0.009) and fewer patients had a history of coronary artery disease, hypertension, and diabetes mellitus. A family history of cardiovascular disease was significantly more prevalent among the young patients (53.4% vs 41.9%, P = 0.0002). Significantly more younger patients than older patients were smokers at the time of infarction (76.2% vs 42.9%, P < 0.0001) and the average number of cigarettes smoked per day was also significantly higher in young patients (27.8 +/- 14.3 vs 19.9 +/- 12.9, P < 0.01). Younger patients had a better outcome, with lower rates of cardiogenic shock (1.1% vs 7.0%, P = 0.0002), stroke (0.0% vs 1.9%, P = 0.02) and haemorrhage (1.9% vs 5.9%, P = 0.006), as well as a better Killip class at discharge (Killip > 1 in 4.5% vs 8.0%, P < 0.001), and lower hospital and 6-month mortality (0.7% and 3.1% vs 8.3% and 12%, P < 0.001, respectively). The better outcome of younger patients with acute myocardial infarction is related to their better baseline characteristics. Young patients with acute myocardial infarction have a strong family history of cardiovascular disease and a high prevalence of smoking. Smoking is the most important modifiable risk factor in these patients.

Adolescent↗
PubMed1994

Outcome of thrombolytic therapy in relation to hospital size and invasive cardiac services. The Investigators of the International Tissue Plasminogen Activator/Streptokinase Mortality Trial.

OBJECTIVE: The outcome of patients with acute myocardial infarction who received thrombolytic therapy was assessed in relation to the size and comprehensiveness of cardiovascular services in the admitting hospitals. METHODS: Two characteristics were obtained for each of the 438 hospitals: number of beds and in-house availability of cardiovascular services (coronary catheterization laboratory and coronary angioplasty or bypass surgery). Hospitals were grouped into four categories on the basis of size (< or = 300 vs > 300 beds) and availability of cardiovascular services. Baseline and outcome variables were compared by chi 2 analysis and logistic regression. Patients were followed up for 6 months. RESULTS: Baseline variables were comparable among hospital categories except for significant differences in the distribution of antecedent angina and time to treatment. Significantly more coronary angioplasties and bypass surgeries were performed in patients first treated in hospitals with coronary revascularization services (4.1% and 4.2% vs 1.0% and 1.9%, P < .0001). Rates of strokes (1.9% vs 1.3% and 1.6%, P = .54), hospital mortality (11.9% vs 8.5%, (P = .11), and 6-month mortality (17.0% vs 11.8% and 12.3%, P = .03) were highest among patients treated in small hospitals that had coronary revascularization facilities. The rate of invasive procedures was higher in the smaller hospitals (odds ratio [OR], 1.44; 95% confidence limits [CL], 1.11 and 1.87; P = .006) and in hospitals with coronary revascularization services (OR, 4.05; 95% CL, 3.14 and 5.22; P < .0001); hemorrhage was more frequent in centers with coronary revascularization facilities (OR, 1.39; 95% CL, 1.13 and 1.71; P = .002). Rates of hospital mortality and 6-month mortality were similar. CONCLUSIONS: Patients with acute myocardial infarction treated with thrombolytic therapy have the same mortality in small centers without in-house coronary revascularization services as in larger centers with such services.

Aged↗
PubMed1994

Rubinstein-Taybi syndrome with piebaldism.

A young girl is reported suffering from multiple congenital anomalies typical of Rubinstein-Taybi syndrome, in association with cutaneous lesions of piebaldism and occipital poliosis. Clinical characteristics of both entities are described and cutaneous manifestations of Rubinstein-Taybi syndrome are reviewed. To the best of our knowledge, this is the first case reporting such an association.

Child↗
PubMed1994

Clinical perspectives of periodontal and restorative interactions.

Restorative treatment and periodontal health are directly interrelated. A restorative treatment plan must consider periodontal support and provide for adequate maintenance of the health of the periodontium. For example, prosthetic design must facilitate hygiene practices and not violate the physiologic dimensions of the periodontium. The relation of the periodontium to margin preparation, margin placement, crown contours, and pontic design are discussed in this article.

Crown Lengthening↗
PubMed1993

Utilization of ketone bodies by chick brain and spinal cord during embryonic and postnatal development.

Lipid synthesis from acetoacetate and 3-hydroxybutyrate was studied in chick embryo from 15 to 21 days and in chick neonate from 1 to 21 days. Embryonic spinal cord showed higher ability than brain to incorporate acetoacetate into total lipids, although a sharp decrease was found at hatching. 3-Hydroxybutyrate incorporation into total lipids was also higher in spinal cord than in brain, especially during the embryonic period. Phospholipids were the main lipids formed in both tissues from both precursors. An appreciable percentage of radioactivity was also recovered as free cholesterol, especially during the embryonic phase. The developmental patterns of amino acid synthesis from acetoacetate and 3-hydroxybutyrate were similar in both tissues: a clear increase after hatching was followed by a decrease at day 4 of neonatal life. Acetoacetate was a better substrate for amino acid synthesis than 3-hydroxybutyrate during the embryonic development in both tissues. Oxidation of both precursors to CO2 strongly decreased between 15 and 21 days of embryonic development both in brain and spinal cord.

3-Hydroxybutyric Acid↗
PubMed1993

Changes in ketone body utilization by chick liver, duodenal mucosa and kidney during embryonic and postnatal development.

1. Lipid synthesis from acetoacetate and 3-hydroxybutyrate in chick kidney and duodenal mucosa showed a clear decrease between 15 and 19 days of the embryonic phase, followed by an increase at hatching and a new decrease during the first neonatal period. The hepatic synthesis of lipids presented a different profile: a peak at 19-day-old embryo and a new increase during postnatal development. 2. These changes would be related to those in 3-hydroxybutyrate concentration in chick plasma throughout the perinatal period. 3. Phospholipids were the main kind of lipid formed in the three tissues. An appreciable percentage of radioactivity was also recovered as free cholesterol, especially during the embryonic phase. Triglycerides were also formed from acetoacetate in a high proportion in liver from neonatal animals. 4. Chick kidney showed the maximal ability to incorporate both precursors into amino acids. The peak obtained around hatching time would be related to the availability of the substrates. 5. Ketone body oxidation to CO2 was also maximal in kidney. In this tissue, a drastic decrease was observed during the final embryonic period, followed by a strong increase at day 1 after hatching and a new decrease at 4 days.

3-Hydroxybutyric Acid↗
PubMed1993

Significance of smoking in patients receiving thrombolytic therapy for acute myocardial infarction. Experience gleaned from the International Tissue Plasminogen Activator/Streptokinase Mortality Trial.

BACKGROUND: Despite the fact that smoking is a well-established risk factor for the development of coronary artery disease, some investigators have noted that hospital mortality after acute myocardial infarction is lower in patients who smoke than in nonsmoking patients. To evaluate the association of smoking with mortality during hospitalization after thrombolytic therapy and 6 months afterward, we analyzed the results of the International Tissue Plasminogen Activator/Streptokinase Mortality Trial. METHODS AND RESULTS: Patients were divided into three groups: nonsmokers (those who never smoked), ex-smokers, and active smokers. Multivariate and univariate comparisons were made with respect to baseline characteristics and clinical outcome. There were 2,366 nonsmokers, 2,244 ex-smokers, and 3,649 active smokers. The baseline characteristics of nonsmoking patients differed significantly from the ex-smokers and active smokers. The nonsmoking group included more women than the ex-smokers or active smokers (45% versus 10.6% and 17.6%, respectively), was older (67 +/- 10 years versus 64 +/- 10 years and 58 +/- 11 years), had a higher rate of diabetes mellitus (16.3% versus 11.1% and 7.5%), and had a worse Killip class at admission. Nonsmoking patients and ex-smokers experienced more in-hospital reinfarction than active smokers (4.7% and 5% versus 2.7%, p < 0.0001, respectively). Nonsmokers experienced more in-hospital shock than the ex-smokers or active smokers (9.2% versus 6.4% and 5.8%, p < 0.0001), stroke (1.9% versus 1.8% and 0.8%, p < 0.0001), and bleeding (7.2% versus 6.5% and 4.4%, p < 0.0001). They also experienced a higher in-hospital and 6-month mortality (12.8% and 17.6%) than ex-smokers (8.2% and 12.1%) or active smokers (5.4% and 7.8%) (p < 0.0001). A multivariate analysis accounting for all baseline characteristics demonstrated a significant association between nonsmoking and increased hospital mortality, with an odds ratio of 1.42 (confidence limits, 1.15-1.72). Among active smokers, there was a nonsignificant trend for mortality rates to decrease with increasing numbers of cigarettes smoked per day. CONCLUSIONS: This retrospective analysis indicates that smokers receiving thrombolytic therapy after acute myocardial infarction have significantly better hospital and 6-month outcome than nonsmokers or ex-smokers. However, smokers sustained their infarction at a significantly earlier age than nonsmokers, and strenuous efforts should continue to be made to decrease the incidence of new and continued smoking.

Aged↗
PubMed1993

After correcting for worse baseline characteristics, women treated with thrombolytic therapy for acute myocardial infarction have the same mortality and morbidity as men except for a higher incidence of hemorrhagic stroke. The Investigators of the International Tissue Plasminogen Activator/Streptokinase Mortality Study.

BACKGROUND: In the prethrombolytic era, women with myocardial infarction were reported to have a worse outcome than men. This analysis evaluates the association of sex with morbidity and mortality after thrombolytic therapy. METHODS AND RESULTS: Data were analyzed from 8261 of the 8387 randomized patients with acute myocardial infarction who received thrombolytic therapy in the International Tissue Plasminogen Activator/Streptokinase Mortality Study (baseline data were missing for 126 patients) and were followed for 6 months. Women made up 23% (n = 1944) of the study population. Baseline characteristics were worse in women: they were 6 years older, were more likely to have a history of previous infarction (P < .01), antecedent angina (P < .01), hypertension (P < .0001), or diabetes (P < .0001); were in a higher Killip class on admission (P < .0002); and received thrombolytic therapy 18 minutes later than men (P < .0001). Fewer women were smokers (P < .0001). Women had a higher hospital (12.1% versus 7.2%, P < .0001) and 6-month mortality (16.6% versus 10.4%, P < .0001) and were more likely to develop cardiogenic shock (9.1% versus 6.3%, P < .0001), bleeding (7.2% versus 5.3%, P < .01), and hemorrhagic (1% versus 0.3%, P < .001) or total stroke (2.2% versus 1.1%, P < .0001) during hospitalization. Reinfarction rates and requirement for angioplasty or surgery did not differ. After correction for worse baseline characteristics, women had similar morbidity and mortality apart from a significantly higher incidence of hemorrhagic stroke, which remained significant even after accounting for weight and treatment allocation (odds ratio, 2.90; P < .01). CONCLUSIONS: After thrombolytic therapy for acute myocardial infarction, women have similar morbidity and mortality to men but suffer from a higher incidence of hemorrhagic stroke.

Aged↗
PubMed1993

Experience with moderate intensity anticoagulation and aspirin after mechanical valve replacement. A retrospective, non-randomized study.

A selected group of patients who underwent valve replacement were analyzed to evaluate the feasibility, effectiveness and safety of combined treatment with moderate intensity anticoagulation plus aspirin. One hundred ninety-six patients who received a total of 204 mechanical valve prostheses between 1985 and 1991 were selected according to rigid criteria. The prostheses included 124 valves of caged ball design, 62 St. Jude valves and 18 others. The follow up of the whole population was 581.8 patient years, with an average of 2.97 patient years, and was complete by the definition criteria. All patients received moderate intensity anticoagulation with acenocoumarol (target International Normalized Ratio 2.5 to 3.5) and daily aspirin (100 mg or 325 mg). The incidence of thromboembolic events for the whole group was 3.26% per patient year, but only 1.6% in patients "compliant" with treatment. Preoperative embolism and non-compliance with treatment had a strong correlation with postoperative thromboembolism. The INR values had a strong correlation with both thromboembolic and hemorrhagic events. The incidence of serious hemorrhagic events was 4.12% patient years although only two cases (0.34%/pty) were fatal (cerebral hemorrhages). There was no difference in hemorrhagic incidence between patients receiving either 325 mg or 100 mg daily. A low incidence of thromboembolic complications was attained with the use of combined antithrombotic and antiplatelet therapy, even in the first generation caged ball type prostheses. However, the combination of moderate intensity anticoagulation with either 325 mg or 100 mg aspirin was associated with a risk of bleeding similar to high intensity anticoagulation alone. The risk of bleeding appeared to be greater in the presence of gastric pathology, and the combination of anticoagulants and aspirin should be avoided in patients with these conditions.

Acenocoumarol↗
PubMed1992

Results of surgical management of portosystemic shunts in dogs: 20 cases (1985-1990).

Serum bile acid (SBA) values were obtained in 20 dogs, 2.5 to 60 months (mean, 18.6 months) after surgery for occlusion of a congenital portosystemic shunt. The SBA values obtained after food was withheld were significantly (P < 0.005) reduced at follow-up, compared with preoperative values. In 85% of the dogs (17/20), response to surgery was graded by the owners as excellent or good, although most dogs had abnormal SBA values at follow-up. Significant difference in clinical results or follow-up SBA values was not found in dogs that had complete or partial occlusion of the shunting vessel. Correlation between clinical results and SBA values also was not detected. Dogs that were > 2 years old at the time of diagnosis and surgery had a significantly (P = 0.012) poorer clinical result than that of dogs < 1 year old.

Animals↗
PubMed1992

Passive protective effect of chicken egg yolk immunoglobulins against experimental enterotoxigenic Escherichia coli infection in neonatal piglets.

Passive protection of neonatal piglets against fatal enteric colibacillosis was achieved with powder preparations of specific antibodies against K88, K99, and 987P fimbrial adhesins of enterotoxigenic Escherichia coli. The antibody powders were obtained by spray drying the water-soluble protein fraction of egg yolks from immunized hens after the lipid components were precipitated with an aqueous dispersion of acrylic resins (Eudragit L30D-55; Rohm pharma). The anti-K88, -K99, and -987P antibody preparations reacted specifically against the corresponding fimbrial antigens in an enzyme-linked immunosorbent assay. The orally administered antibodies protected in a dose-dependent fashion against infection with each of the three homologous strains of E. coli in passive immunization trials with a colostrum-deprived piglet model of enterotoxigenic E. coli diarrhea. Scanning electron microscopy revealed adherence of enterotoxigenic E. coli in intestinal epithelial surfaces of control piglets, whereas in treated piglets treated with high-titer antibodies, a resistance to bacterial adhesion was observed. An enzyme immunoassay with avidin-biotin complex demonstrated specific local antibody activity in target areas of the small intestines. In vitro, E. coli K88+, K99+, and 987P+ strains adhered equally to porcine duodenal and ileal epithelial cells but failed to do so in the presence of homologous anti-fimbrial antibodies. Absorption of egg yolk antibodies with fimbrial immunosorbent removed the anti-fimbrial antibody fraction and reduced significantly the protective nature of the antibody preparation in a passive immunization experiment, suggesting that anti-fimbrial antibodies were the active components.

Animals↗
PubMed1992

Comparative effect of fasting on acetoacetate and D-3-hydroxybutyrate metabolism in the newborn chick.

The effect of 24 h fasting on ketone body utilization by three extranervous tissues, liver, duodenum and kidney, was studied in two critical ages of neonatal chick: 4 and 9 days. In 4-day-old chick, plasma concentration of 3-hydroxybutyrate increased about 9-fold after 24 h starvation, while in 9-day-old chick this parameter increased about 23-fold in the same conditions. Hepatic lipogenesis from both precursors sharply decreased by fasting. Changes in the lipogenic activity of duodenum were less patent. However, we have found a clear increase in lipogenesis in chick kidney after 24 h starvation. CO2 production from acetoacetate was higher than that found from hydroxybutyrate. No significant differences in the acetoacetate oxidation to CO2 was observed in any tissue assayed after 24 h fasting. 14C incorporation from ketone bodies into amino acids was clearly decreased in kidney from 9-day-old chick by fasting. In liver and duodenum, acetoacetate incorporation into amino acids was higher than that from hydroxybutyrate.

3-Hydroxybutyric Acid↗