Modulatory role of endothelium-derived relaxing factors on the flow-regulated coronary vascular resistance.
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Adenosine↗
Biomedical subjects
J Suarez
Publications and source records attributed to J Suarez.
Differences in sleep variables, blood adenosine, and body temperature between hypothyroid and euthyroid rats before and after REM sleep deprivation.
Sleep deprivation causes an increase in energy expenditure in animals. Thyroid gland function has been related to metabolic function, and this may be compromised in sleep manipulations. The objectives of the present study were the following: 1) to develop a model of hypothyroid rats by surgical removal of thyroid glands without extirpation of the parathyroid; 2) to observe the sleep architecture in euthyroid (Etx) and hypothyroid (Htx) rats, both before and after rapid eye movement (REM) sleep deprivation (96 hours); 3) to challenge both groups (i.e. Etx and Htx) with REM sleep deprivation (96 hours) and then evaluate the effects on temperature; and 4) to measure the levels of adenosine and thyroid hormones in blood. One-month-old Wistar male rats (weight 90-100 g) were studied. The thyroid gland was removed, and the parathyroid glands were reimplanted within the neck muscle (Htx) under halothane anesthesia. A sham-operated group was also included (Etx). Four months later, the animals were studied according to the following protocols. Protocol 1: Animals of both groups (i.e. Etx and Htx) were implanted for sleep recordings. After a baseline polysomnography, these animals were REM sleep deprived by the platform method (96 hours). Protocol 2. An intraperitoneal temperature transducer was placed into animals of both groups under deep halothane anesthesia. They were studied at baseline, during 96 hours of REM sleep deprivation, and on the rebound period. Protocol 3: Plasma thyroid hormones [T3, T4, and thyroid-stimulating hormone (TSH)] and plasma adenosine were determined in both groups. Results of protocol 1 indicated that the main difference observed in Htx rats during the baseline sleep was an increase in delta sleep (slow-wave sleep 2) and a reduction in waking time compared with Etx animals. REM sleep rebound after 96 hours of REM sleep deprivation was similar in both groups. In protocol 2, the main finding was that Htx animals had reduced body temperature. A significant difference in body temperature between Etx and Htx animals was found mainly during lights-on period. REM sleep deprivation in the Etx group produced an increase in body temperature. Htx animals showed the opposite effect, with a reduction in body temperature during and after REM sleep deprivation. In protocol 3, the main findings were that Htx animals exhibited a significant reduction in blood thyroid hormones (T3, T4), and that they also had high levels of plasma adenosine. REM sleep deprivation produces changes in temperature regulation. The increase in body temperature during REM sleep deprivation may require thyroid integrity. Absence of the thyroid gland does not seem to influence REM sleep recovery after its deprivation. The high plasma adenosine levels found in the Htx group may explain the increase in delta sleep in this group.
Adenosine↗
Extubation outcome after spontaneous breathing trials with T-tube or pressure support ventilation. The Spanish Lung Failure Collaborative Group.
A 2-h T-tube trial of spontaneous breathing was used in selecting patients ready for extubation and discontinuation of mechanical ventilation. However, some doubt remains as to whether it is the most appropriate method of performing a spontaneous breathing trial. We carried out a prospective, randomized, multicenter study involving patients who had received mechanical ventilation for more than 48 h and who were considered by their physicians to be ready for weaning according to clinical criteria and standard weaning parameters. Patients were randomly assigned to undergo a 2-h trial of spontaneous breathing in one of two ways: with a T-tube system or with pressure support ventilation of 7 cm H2O. If a patient had signs of poor tolerance at any time during the trial, mechanical ventilation was reinstituted. Patients without these features at the end of the trial were extubated. Of the 246 patients assigned to the T-tube group, 192 successfully completed the trial and were extubated; 36 of them required reintubation. Of the 238 patients in the group receiving pressure support ventilation, 205 were extubated and 38 of them required reintubation. The percentage of patients who remained extubated after 48 h was not different between the two groups (63% T-tube, 70% pressure support ventilation, p = 0.14). The percentage of patients falling the trial was significantly higher when the T-tube was used (22 versus 14%, p = 0.03). Clinical evolution during the trial was not different in patients reintubated and successfully extubated. ICU mortality among reintubated patients was significantly higher than in successfully extubated patients (27 versus 2.6%, p < 0.001). Spontaneous breathing trials with pressure support or T-tube are suitable methods for successful discontinuation of ventilator support in patients without problems to resume spontaneous breathing.
Aged↗
Factors influencing the return to work of patients after hip replacement and rehabilitation.
OBJECTIVE: To determine the incidence of medical and sociocultural factors on the return to work of patients after hip replacement and rehabilitation treatment. DESIGN: Case review. Frequency and association of variables' analysis. SETTING: The rehabilitation unit of a general hospital in Oviedo (Spain). This setting is a part of an institutional referral center and is the only state-owned hospital that provides rehabilitation treatment for hospitalized patients from a rural and urban area of about 1,000,000 inhabitants. PATIENTS: 747 patients of both sexes, all of them working before receiving treatment, age range 18 to 64 years. MAIN OUTCOME MEASURES: Relationship of several variables: age, sex, habitat, level of education, type of work, underlying illness, walking ability, pain, and type of social security versus return to work. RESULTS: At discharge, 25% of patients return to work. There is a significant association (p < .001) between return to work and any of the following variables: underlying illness, kind of work, walking ability, habitat, and educational level. CONCLUSION: This physiopathology of symptoms and signs of the patients is not the unique indicator of whether a person will continue working after hip replacement and rehabilitation treatment. Extramedical factors, such as social status, kind of work, and cultural background, are very influential.
Adolescent↗
Congenital neuromuscular diseases presenting in adulthood.
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AMP Deaminase↗
Ciprofloxacin-induced glottic angioedema.
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Angioedema↗
Coronary flow stimulates auricular-ventricular transmission in the isolated perfused guinea pig heart.
In the heart in situ coronary flow stimulates oxygen consumption, glycolytic flux, myocardial contractility, and the release of bioactive substances. Studies have indicated that the coronary flow-enhanced contraction is similar to a hormonelike effect because the enhanced contraction results from an elevation in intracellular free calcium. In fact, if extracellular calcium is raised sufficiently, the contraction amplitude rises and remains constant and independent of coronary flow. We hypothesized that coronary flow could also stimulate other calcium-dependent cardiac functions such as auricular-ventricular (A-V) transmission. This hypothesis was tested in isolated guinea pig hearts perfused at constant flow. Our results show that increases in coronary flow (6-25 ml/min range) decrease the A-V delay solely as a result of reduced propagation time in the A-V node and not in atrial or ventricular propagation. When coronary vascular resistance was altered by dilation (nitroglycerin, bradykinin, nitroprusside, and adenosine) or by constriction (angiotensin II), this dromotropic effect of flow remained the same despite wide changes in perfusing pressure. Also, this dromotropic effect of flow was not altered by energy-altering substrates in the perfusate or by perfusion of adenosine receptor blockers. Furthermore, the effectiveness of flow as a dromotropic stimulus varied inversely with changes in calcium entry caused either by elevation or reduction of extracellular calcium. In addition, enhanced viscosity of the perfusing medium amplifies the positive dromotropic effect of flow. These results suggest that coronary flow is a stimulus that exerts a positive dromotropic effect mediated by shear stress.
Aminophylline↗
Left ventricular perforation by a pleural drainage tube. Report of a case with survival.
We present a case of survival as a result of surgical intervention after perforation of the left ventricle during the insertion of a pleural drainage tube. Surgical intervention was facilitated by the fact that the drainage tube responsible for the suspected perforation of the cardiac cavity was clamped and fastened, as opposed to withdrawn. The location of the perforation was established by measuring the pressure curve through the drainage tube.
Drainage↗
Implications of the coronary vascular endothelium as mediator of the vasodilatory and dromotropic actions of adenosine.
Recent studies have shown that the vasodilatory response of adenosine is partially endothelium dependent. Therefore, to further characterize the physiologic role of the vascular endothelium as mediator of adenosine's cardiovascular effects, we have examined in isolated perfused guinea-pig hearts the dromotropic and vascular effects of adenosine in the presence of the adenosine antagonist, XAC, covalently conjugated to latex microspheres of 0.07 microns diameter. Our results demonstrate that intravascular infusion of the microsphere XAC conjugates abolishes the vasodilatory and negative dromotropic effects of infused adenosine, and inhibits the dromotropic effects of hypoxia. As these particles because of their size remain intravascularly confined, we conclude that the dromotropic and vasodilatory effects of exogenous adenosine, and the dromotropic effects of hypoxia (endogenous adenosine), arise from the intravascular adenosine compartment acting by way of the vascular endothelium. In addition, while neither the temporal course of vasodilation nor the steady state of vasodilation caused by hypoxia were influenced by unconjugated XAC, our results do show that the microsphere XAC conjugate increases the time necessary for maximum vasodilation to occur during hypoxia.
Adenosine↗
Evaluation of an immunoperoxidase technique using an only biotin-labeled antibody for the demonstration of Actinobacillus pleuropneumoniae in tissue sections.
In this report an immunoperoxidase technique (IPB) using an only biotin-labeled antibody is compared to culture isolation method (CIM) for the demonstration of Actinobacillus pleuropneumoniae serotype 1 in tissues of mice inoculated intravenously. The organism was isolated in 86.7% of mice and detected by IPB in 100% of cases. A. pleuropneumoniae antigen was mainly demonstrated in the liver, spleen and lungs, but also in the kidney and brain, being especially located in the cytoplasm of macrophages. Significant differences were observed between the results obtained by both tests (P < 0.001). Cross-reactions occurred by IPB when a rabbit anti-A. pleuropneumoniae serotype 11 serum was tested but never when an anti-serotype 9 serum was used. The immunoperoxidase test here described yielded much better results than CIM and it could be useful in routine diagnosis of A. pleuropneumoniae infections.
Actinobacillus Infections↗
Functional role of intravascular coronary endothelial adenosine receptors.
The endothelium is relatively 'impermeable' to adenosine. In addition, infusion of adenosine deaminase and transient infusion of large size adenosine agonists (molecular weight 100 kD) which are confined to the intravascular space depress effects of endogenous adenosine and retain physiologic activity respectively. Accordingly, the concept that intravascular adenosine may exert some of its action on the capillary lumen was tested by coupling the agonists: N6-([aminoethylamino]carbonyl)methylphenyladenosine (ADAC) and N6-octylamine adenosine (NOA) to carboxylated latex microspheres (0.07 microns diameter); thus, insuring their intravascular confinement. Our results demonstrated that sustained infusion of these particles into isolated saline perfused guinea pigs hearts caused a decrease in coronary vascular resistance, ventricular contraction, spontaneous ventricular rhythm, inhibition of auricular ventricular transmission and glycolytic flux. These effects were reversible and specific since microspheres without purines had no effect and the adenosine antagonist sulphophenyltheophylline blocked these responses. Furthermore, the effects were not the result that during the passage of the sphere-agonist complex through the heart the covalent bond hydrolyzed, releasing free agonist. Our data indicate that selective activation of intravascular coronary purine receptors may cause the release of endothelial bioactive messengers that regulate the function and metabolism of vascular and cardiac cells.
Adenosine↗
Anteroposterior shift in rigid and soft implants supported by the intraocular capsular bag.
We compared the depth of the anterior chamber and the optimal distance refraction in a group of patients with soft and rigid intraocular implants under pilocarpine (maximal ciliary contraction) and cyclopentolate (maximal ciliary relaxation) in order to determine if lens movement might account for the apparent accommodation phenomenon. Lens shifts ranging from 1.5 to 0.02 mm and refractive variations up to 1 D were found. However, the discrepancies between amount of shift and refractive variations suggest that lens movement does not play a relevant role in this phenomenon.
Accommodation, Ocular↗
Epileptic seizures in an Andean region of Ecuador. Incidence and prevalence and regional variation.
A large-scale neuro-epidemiological study was carried out in a population of 72,121 inhabitants of a region of Northern Ecuadorian Andean Sierra, to identify prevalence and incidence rates of epileptic seizures and to identify demographic and geographic variations in these rates. Calculations were made using three datasets. First, rates were calculated from all cases identified in the field (raw dataset); secondly, lower rates were calculated based on a further diagnostic and reclassification procedure (minimum estimated dataset); thirdly, higher rates were derived by calculating false negative rates from the screening procedures, and adding these to the cases actually identified (maximum estimated dataset). Lifetime point-prevalence rates between 12.2/1000 and 19.5/1000 were recorded (minimum and maximum estimated rates), and the prevalence of active epileptic seizures was between 6.7/1000 and 8.0/1000 (minimum estimated and raw datasets). Incidence rate ranging between 122/100,000/year and 190/100,000/year were found (minimum, estimated and raw datasets). A marked difference in prevalence rates was found in two subregions of the survey area, and also in urban and rural areas. The reasons for these differences were not identified.
Adolescent↗
A large-scale study of epilepsy in Ecuador: methodological aspects.
The methodology is presented of a large-scale study of epilepsy carried out in a highland area in northern Ecuador, South America, covering a population of 72,121 people; The study was carried out in two phases, the first, a cross-sectional phase, consisted of a house-to-house survey of all persons in this population, screening for epileptic seizures using a specially designed questionnaire. Possible cases identified in screening were assessed in a cascade diagnostic procedure applied by general doctors and neurologists. Its objectives were: to establish a comprehensive epidemiological profile of epileptic seizures; to describe the clinical phenomenology of this condition in the community; to validate methods for diagnosis and classification of epileptic seizures by a non-specialised team; and to ascertain the community's knowledge, attitudes and practices regarding epilepsy. A sample was selected in this phase in order to study the social aspects of epilepsy in this community. The second phase, which was longitudinal, assessed the ability of non-specialist care in the treatment of epilepsy. It consisted of a prospective clinical trial of antiepileptic therapy in untreated patients using two standard anti-epileptic drugs. Patients were followed for 12 months by a multidisciplinary team consisting of a primary health worker, rural doctor, neurologist, anthropologist, and psychologist. Standardised, reproducible instruments and methods were used. This study was carried out through co-operation between the medical profession, political agencies and the pharmaceutical industry, at an international level. We consider this a model for further large-scale studies of this type.
Adolescent↗
Chemotherapy-induced neutrophilic eccrine hidradenitis in acute myeloid leukemia.
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Acute Disease↗
Exercise echocardiography versus 201Tl single-photon emission computed tomography in evaluation of coronary artery disease. Analysis of 292 patients.
BACKGROUND: Exercise echocardiography (digital cine-loop technique) and 201Tl single-photon emission computed tomography (SPECT) were performed simultaneously in 292 patients being evaluated for coronary artery disease. METHODS AND RESULTS: Pretreadmill and posttreadmill echocardiographic images of diagnostic quality were obtained in 289 patients, and the left ventricle was divided into anterior, inferior, and lateral regions. Any wall motion or perfusion abnormality observed within each region was classified as totally reversible, fixed, or partially reversible. Exercise echocardiography and SPECT were normal in 137 patients and abnormal in 118 (88% agreement). Equal numbers of regional abnormalities were detected by one test when missed by the other. The two tests had an 82% agreement in detecting the same type of finding within the regions analyzed. SPECT detected more reversible abnormalities than echocardiography, whereas echocardiography detected more fixed abnormalities than SPECT: Regions with a fixed abnormality by echocardiography frequently showed partial reversibility of a perfusion defect by SPECT: Nearly one third of regions with fixed perfusion defects by SPECT demonstrated normal resting function or reversible abnormalities by echocardiography. Sensitivity for coronary artery disease by angiography (greater than or equal to 50% diameter stenosis) in 112 patients was similar for the two tests, ranging from 58% and 61% (echocardiography and SPECT, respectively) for one-vessel disease to 94% for three-vessel disease. The specificities for echocardiography and SPECT were 88% and 81%, respectively. CONCLUSIONS: Exercise echocardiography had a diagnostic accuracy comparable to that of SPECT for the detection of regional abnormalities produced by significant coronary artery disease. A greater number of abnormal regions were detected with the combined use of both tests.
Coronary Angiography↗
Cutaneous nocardiosis and human immunodeficiency virus infection.
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Adult↗
Colposcopic evaluation of human immunodeficiency virus-seropositive women.
To determine the effect of human immunodeficiency virus (HIV) infection on cervical histology, 32 known HIV-seropositive women underwent cervical colposcopic evaluation. All had cervical cytology, colposcopically directed biopsy, and T-cell studies performed. Thirteen of 32 patients (41%) had cervical intraepithelial neoplasia (CIN). Another 14 of 32 patients (44%) had histologic evidence of cervicitis. Abnormal cytology, noted in only three women, suggested CIN in one and inflammatory atypia in two. All (five of five) patients with a clinical diagnosis of AIDS had CIN, compared with 30% (eight of 27) of non-AIDS HIV-positive patients (P less than .05). Patients diagnosed with CIN had significantly lower CD4 cell counts (221/mm3 versus 408/mm3; P less than .06) and CD4:CD8 ratios (0.33 versus 0.62; P less than .02) than those without CIN. Patients with cervicitis had greater T-cell immunosuppression than did those with normal histology. In addition, patients with AIDS were more likely to have higher-grade lesions than were non-AIDS HIV-seropositive patients. Seven of 12 CIN specimens available for analysis by polymerase chain reaction using consensus sequence primers detected human papillomavirus (HPV) DNA, including three patients with three or more HPV types. Our data suggest that abnormal cervical pathology is common among HIV-positive women and that cytologic screening is not predictive of CIN in this population. In addition, the presence and severity of cervical dysplasia correlates with quantitative T-cell function. We strongly recommend that cervical colposcopy be part of the routine management of HIV-seropositive women.
Adult↗