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Biomedical subjects

R Wilson

Publications and source records attributed to R Wilson.

At least 883 records · Page 49Linked to original sources
PubMedDate not supplied

Suppression of ventricular arrhythmias after coronary artery ligation by pinacidil, a vasodilator drug.

Pinacidil, a new vasodilator compound, has been shown to lower blood pressure in animals and humans by a direct vasodilator effect. We have studied the effects of pinacidil on experimental cardiac arrhythmias in dogs. Pinacidil did not exhibit antiarrhythmic activity on ouabain-induced arrhythmias. In contrast, verapamil had minor antiarrhythmic activity on the ouabain arrhythmia, restoring sinus rhythm in one-third of the dogs studied. Pinacidil suppressed the arrhythmia present 22-24 h after coronary artery ligation at doses which produced a significant reduction in mean arterial pressure. The antiarrhythmic action of pinacidil was not modified by pretreatment with propranolol but appeared to be blunted by the infusion of the alpha-agonist, phenylephrine. Other hypotensive agents, hydralazine and sodium nitroprusside, although producing similar reductions in mean arterial pressure to pinacidil, did not exhibit a consistent antiarrhythmic action in dogs 22-24 h after coronary artery ligation. The calcium antagonist verapamil did not display antiarrhythmic activity on this model. The mechanisms by which pinacidil exerted an antiarrhythmic action have not yet been elucidated. The results of the present study suggest that further studies with pinacidil on myocardial infarct size, myocardial perfusion, and experimental cardiac arrhythmias would be advantageous.

Animals↗
PubMedDate not supplied

Clinical characteristics of infant botulism in the United States: a study of the non-California cases.

We reviewed the clinical features of 99 cases of infant botulism reported to the Centers for Disease Control from states other than California for the period 1976 to 1980. There were no toxin-specific differences in the distribution of ages at onset or sex of the cases. For 76 (76%) patients for whom data were available the most common presenting symptoms were poor feeding (43%) and constipation (24%). Weak suck, poor head control, floppiness, weakness in extremities, difficulty swallowing, altered cry and constipation were reported in over three-fourths of the infants for whom data were available. Loss of facial expression, extraocular muscle paralysis, dilated pupils and depression of deep tendon reflexes occurred significantly more frequently among infants with type B botulism than among those with type A botulism. Ventilatory assistance was required for 61% of infants receiving aminoglycosides after the onset of weakness compared to only 26% of those infants not receiving aminoglycosides (P = 0.01). Infant botulism presents a characteristic clinical picture and should be suspected when an infant presents with weakness.

Aminoglycosides↗
PubMedDate not supplied

Mathematics instruction for secondary students with learning disabilities.

Secondary students with learning disabilities generally make inadequate progress in mathematics. Their achievement is often limited by a variety of factors, including prior low achievement, low expectations for success, and inadequate instruction. This article will discuss techniques that have been demonstrated to be effective with secondary students who have learning disabilities in mathematics.

Achievement↗
PubMedDate not supplied

Reverse arterial blood flow as a pathway for central nervous system toxic responses following injection of local anesthetics.

In baboons, lidocaine HCl was injected into the lingual (3 mg/kg), brachial (7 mg/kg), or femoral (7 mg/kg) arteries. Blood samples were taken from the internal carotid artery (ICA), internal jugular (IJV), external jugular (EJV), brachial (BV), or femoral (FV) vein, depending on the injection site, 6, 30, and 180 seconds after injection. Subsequently, radioactive microspheres (20 micron in diameter) were injected into the lingual artery, and the brains were obtained 48 hours later at postmortem to locate the microspheres. Six seconds after injection into the lingual artery, lidocaine concentration in ICA was 28 microgram/ml, whereas peak levels in IJV and EJV occurred at 30 seconds, being 51 and 25.7 microgram/ml, respectively. After injection into the brachial artery, peak average ICA levels were 105.5 microgram/ml at 6 seconds, while only 20.6 microgram/ml concentration was noted in ICA after injection into the femoral artery. Seventy-four precent of the Sr90 labeled microspheres were found lodged in the ipsilateral cerebral hemisphere. Local anesthetic drugs accidentally injected into arteries may reach the cerebral circulation following a centripetal pathway and thus produce central nervous system toxic responses.

Anesthesia, Local↗
PubMedDate not supplied

Effects of purified Pseudomonas rhamnolipids on bioelectric properties of sheep tracheal epithelium.

The effects of purified rhamnolipids from Pseudomonas aeruginosa on short circuit current in respiratory epithelium have been studied in sheep tracheal epithelium mounted in Ussing chambers under short circuit conditions. In low concentrations (100 microM) mucosal addition of rhamnolipids produces a decrease in short circuit current of 22% and in conductance of 4%. At higher concentrations (> 100 microM), large increases in tissue conductance accompany a greater reduction in short circuit current, suggesting disruption of the intercellular junctions. Serosal addition of rhamnolipids has no effect on ion transport. Pretreatment of the tissues with the sodium channel blocker amiloride (100 microM) or bathing the mucosal surface with sodium-free solution significantly decreased the rhamnolipid-induced fall in short circuit current but did not prevent it completely. Inhibition of chloride transport, sodium-glucose cotransport, and bicarbonate secretion with bumetanide, phloridzin, and acetazolamide, respectively, did not significantly alter the rhamnolipid effect. This suggests that the effect of rhamnolipids on short circuit current is mediated predominantly but not exclusively by an effect on sodium transport. The effects of rhamnolipids on ion transport occur at concentrations within the range occurring in the sputum of patients with cystic fibrosis. The changes in ion transport may explain some of the known effects of rhamnolipid on mucociliary clearance.

Acetazolamide↗
PubMedDate not supplied

The challenge of unintelligible speech following traumatic brain injury.

Management of unintelligible speech following traumatic brain injury is complex. In addition to multiple physiological system deficits, individuals typically present with complicating non-speech factors that impede their progress. The present case study illustrates the influence on outcome of impaired speech physiology, reduced cognitive abilities, pre-morbid personality characteristics, and psychosocial variables such as post-injury psychosis. Highlighted intervention strategies include optimizing the physiological system with a palatal lift prosthesis, reducing speaking rate by pacing, phonetically transcribing words to minimize apraxia of speech, adapting stimuli to optimize auditory comprehension, and providing therapy within functional contexts.

Brain Damage, Chronic↗
PubMedDate not supplied

Condom use and HIV risk behaviors among U.S. adults: data from a national survey.

CONTEXT: How much condom use among U.S. adults varies by type of partner or by risk behavior is unclear. Knowledge of such differentials would aid in evaluating the progress being made toward goals for levels of condom use as part of the Healthy People 2000 initiative. METHODS: Data were analyzed from the 1996 National Household Survey of Drug Abuse, an annual household-based probability sample of the noninstitutionalized population aged 12 and older that measures the use of illicit drugs, alcohol and tobacco. The personal behaviors module included 25 questions covering sexual activity in the past year, frequency of condom use in the past year, circumstances of the last sexual encounter and HIV testing. RESULTS: Sixty-two percent of adults reported using a condom at last intercourse outside of an ongoing relationship, while only 19% reported using condoms when the most recent intercourse occurred within a steady relationship. Within ongoing relationships, condom use was highest among respondents who were younger, black, of lower income and from large metropolitan areas. Forty percent of unmarried adults used a condom at last sex, compared with the health objective of 50% for the year 2000. Forty percent of injecting drug users used condoms at last intercourse, compared with the 60% condom use objective for high-risk individuals. Significantly, persons at increased risk for HIV because of their sexual behavior or drug use were not more likely to use condoms than were persons not at increased risk; only 22% used condoms during last intercourse within an ongoing relationship. CONCLUSIONS: Substantial progress has been made toward national goals for increasing condom use. The rates of condom use by individuals at high risk of HIV need to be increased, however, particularly condom use with a steady partner.

Adult↗
PubMedDate not supplied

Incorporating a behavioral model in health education.

Understanding the concept of behavior formation is vital in facilitating health education effectively in any setting. Traditionally, the health education process was predicated on the cognitive domain. Consequently, other behavioral influences such as attitudes and intentions were not respectively addressed. Several multidimensional behavior models have been used by health educators to favorably influence human behavior. One specific model, based on one's knowledge (beliefs), attitudes, and intentions is particularly suited for educational settings. This model can be used to assess the validity of individual beliefs, nature of attitude, specificity of intentions and associated personal health behaviors. This assessment can serve as a major motivating factor to encourage persons to identify the quality of their current lifestyle and assume personal responsibility for their welfare.

Attitude to Health↗
PubMedDate not supplied

Comparison of the 20-MHz ultrasound probe with ultrasound biomicroscopy in glaucoma.

The 20-MHz ultrasound probe was compared with ultrasound biomicroscopy to determine its usefulness in imaging various glaucomatous conditions. Ten patients with glaucoma underwent anterior segment imaging with both the 20-MHz probe, which attaches to the I3 B-scan (Innovative Imaging Inc., Sacramento, CA), and the Ultrasonic BioMicroscope (UBM; Paradigm Medical Industries, Salt Lake City, UT). All pathology was easily demonstrable using the 20-MHz probe, in one case showing a retinal detachment not seen with the UBM. However, anterior findings such as fluid in the suprachoroidal space and sclerostomy sites in postoperative trabeculectomy cases were more difficult to view with the 20-MHz probe. The use of coupling enhanced the quality of the latter images. The 20-MHz ultrasound probe may be a viable aid in diagnosis and follow-up of certain glaucomatous conditions, and the use of a coupling device enhances its images.

Anterior Eye Segment↗