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Biomedical subjects

L S Smith

Publications and source records attributed to L S Smith.

At least 55 records · Page 3Linked to original sources
PubMed1988

Effectiveness of teaching breast self examination during office visits.

In a randomized clinical trial a comparison was made of two BSE teaching interventions delivered by primary providers during office visits in a group nursing faculty practice. Patients who reported no regular BSE (n = 121) received either individualized teaching focused on reducing perceived barriers and reinforcing benefits of BSE, or routine teaching limited to usual instruction in BSE technique. Patients reporting frequent/monthly BSE during the past year were comparison subjects (n = 81). Self-reported data on BSE behavior were obtained in questionnaires administered before the interventions and via telephone interviews three months after the visit. Analysis using chi square showed that, contrary to expectation, individualized and routine teaching were equally effective: 61.4% of the individually taught and 63.5% of the routinely taught reported frequent or monthly practice at followup. Both groups were significantly more confident in technique and ability to detect change in the breast. The previously non-practicing women remained significantly less likely than comparison subjects to be performing BSE monthly at followup. The perceived benefit of BSE giving peace of mind predicted non-practicers most likely to change.

Adult↗
PubMed1988

Evaluation and management of the muscle contraction headache.

Headache was the seventh most frequent reason for a visit to primary care providers specified in the 1977-1978 National Ambulatory Care Survey. Muscle contraction headaches (MCH) constitute 90 percent of all headaches. Following a discussion of the epidemiology of headache, this article describes the pathophysiology, history, psychological profile of the typical MCH patient, common objective findings of MCH versus intracranial mass, physical findings and diagnosis. The management section includes a discussion of education and appropriate pharmacologic treatment, along with non-pharmacologic treatments such as massage, acupressure, biofeedback and stress management. Acupuncture is briefly described. Referral criteria for the MCH is included.

Acupuncture Therapy↗
PubMed1987

The fate of inorganic phosphate and pH in regional myocardial ischemia and infarction: a noninvasive 31P NMR study.

To determine the characteristic appearance of phosphorus (31P) nuclear magnetic resonance spectra in acute and chronic myocardial infarction in situ, cardiac-gated depth-resolved surface coil spectroscopy (DRESS) at 1.5 T was used to monitor 31P NMR spectra from localized volumes in the left anterior canine myocardium for up to 5 days following permanent occlusion of the left anterior descending coronary artery. Coronary occlusion initially produced regional ischemia manifested as significant reductions in the phosphocreatine (PCr) to inorganic phosphate (Pi) ratios and intracellular pH (P less than 0.05, Student's t test) in endocardially displaced spectra acquired in periods as short as 50 to 150 s postocclusion. Spectra acquired subsequently revealed either (i) restoration of near-normal phosphate metabolism sometime between 10 and about 50 min postocclusion or (ii) advancing ischemic phosphate metabolism at about an hour postocclusion, and/or (iii) maintenance of depressed PCr/Pi ratios for up to 5 days postocclusion with a return of the apparent pH to near normal values between 6 and 15 h postocclusion. Postmortem examination of animals exhibiting the first type of behavior revealed the existence of coronary collateral vessels. The last type of behavior indicates that Pi remains substantially localized in damaged myocardium for days following infarction. The location and size of infarctions were determined postmortem by staining excised hearts. The smallest infarctions detected by 31P DRESS weighed 4.9 and 7.5 g. The most acidic pH measured in vivo was 5.9 +/- 0.2. Infarctions aged 1/2 day to 5 days were characterized by elevated but broad Pi resonances at 5.1 +/- 0.2 ppm relative to PCr and significantly depressed PCr/Pi ratios (P less than 0.002, Student's t test) relative to preocclusion values. Contamination of Pi resonances by phosphomonoester (PM) components is a significant problem for preocclusion Pi and pH measurements. These results should be applicable to the detection and identification of human myocardial infarction using 31P NMR and DRESS.

Adenosine Triphosphate↗
PubMed1987

Electrical activity in the heart during hyperkalemic hypothermic cardioplegic arrest: site of origin and relationship to specialized conduction tissue.

Previous studies from this laboratory have shown that low-amplitude electrical activity (LEA) may occur during standard hyperkalemic hypothermic cardioplegic arrest and be undetected by routine monitoring techniques. The present study was designed to elucidate the electrophysiological nature of LEA. Ten dogs were monitored continuously during standard cardioplegic arrest using a 32-channel data acquisition system. In 7 animals (Part I), electrophysiological mapping of the lower right atrial septum during arrest was performed. The initial site of activation of LEA was consistently recorded from the region of the lower atrial septum prior to atrial or ventricular electrical activation. The site of origin of LEA was thus localized to the anatomical region of the atrial septum containing the atrioventricular nodal conduction tissue. In Part II, the electrophysiological mechanism of LEA was investigated in the remaining 3 animals utilizing an intrinsic property of specialized conduction tissue. Inclusion of a calcium channel-blocking agent in standard cardioplegic solution completely prevented the development of LEA in all 3 animals, which is in contrast to findings in previous studies using standard cardioplegic solution alone. These data suggest that LEA may be related to calcium-mediated activation of specialized conduction tissue. This mechanism of activation may explain why LEA cannot be detected by the intraoperative monitoring techniques routinely employed.

Animals↗
PubMed1987

Altered phosphate metabolism in myocardial infarction: P-31 MR spectroscopy.

The high-energy myocardial phosphate metabolism of four patients with acute anterior myocardial infarction after coronary angioplasty and drug therapy was evaluated with cardiac-gated phosphorus magnetic resonance (MR) depth-resolved surface coil spectroscopy (DRESS) 5-9 days after the onset of symptoms. Significant reductions (about threefold) in the phosphocreatine (PCr) to inorganic phosphate (Pi) ratio and elevations in the Pi to adenosine triphosphate (ATP) ratio were observed in endocardially or transmurally derived MR spectra when compared with values from epicardially displaced spectra and values from seven healthy volunteers (P less than .05). High-energy phosphate metabolites and Pi ratios did not vary significantly during the cardiac cycle in healthy volunteers. However, contamination of Pi resonances by phosphomonoester components, including blood 2,3-diphosphoglycerate, precluded accurate spectral quantification of Pi and pH. The results indicate that localized P-31 MR spectroscopy may be used to directly assess cellular energy reserve in clinical myocardial infarction and to evaluate metabolic response to interventions.

Adult↗
PubMed1987

Endobronchial tuberculosis. Serial fiberoptic bronchoscopy and natural history.

Endobronchial tuberculosis in the preantibiotic era was considered a complication of advanced post-primary disease. Bronchial mucosa adjacent to parenchymal cavities was bathed in infectious sputum, resulting in implantation. Effective antituberculosis drug therapy has reduced childhood exposure, resulting in an increase in adult primary tuberculosis with unusual clinical and roentgenographic presentations. We studied four adults with endobronchial tuberculosis who presented with unusual lobe involvement mimicking bronchogenic carcinoma. Fiberoptic bronchoscopy illustrated the range of endobronchial appearances, including evolution of mucosal ulcer to hyperplastic polyp and bronchostenosis. Complete fibrostenosis with lobar atelectasis was observed in one patient, and an eroding tuberculous lymph node in another. In the current era, endobronchial tuberculosis is more likely to be discovered in adults with progressive primary tuberculosis who have non-cavitary lower lung field infiltrates. Bronchial mucosal ulceration can result from submucosal lymphatic spread of organisms from adjacent parenchymal disease, as well as implantation.

Adult↗
PubMed1986

Chronic adult cerebral infarction studied by phosphorus NMR spectroscopy.

Spatially localized phosphorus (P-31) nuclear magnetic resonance (NMR) spectra were recorded in vivo from the brains of nine healthy adults and of four adult patients examined 10 weeks to 7 years following cerebral infarction. Spectra from the healthy adult subjects showed reduced inorganic phosphate (Pi) and phosphoester resonances compared with earlier such measurements in infants. Spectra from subjects with chronic cerebral infarction exhibited no significant differences in the ratios of high-energy phosphate metabolites, Pi, or pH compared with the spectra of the healthy adults, although decreases of up to about 40% in the total P-31 NMR signal from infarcted tissue were noted. These results are consistent with a reduction in the number of metabolically active brain cells and/or a decrease in cellular functional activity in chronic infarction. Phosphorus metabolite ratios do not appear to be a sensitive indicator of abnormal energy reserve in chronic brain infarction in adults.

Adult↗
PubMed1986

Athletic footwear.

The development of technical athletic footwear is based on two interrelated principles: injury prevention and enhanced performance. Most athletes are interested in and will benefit from shoes that prevent injuries. On the other hand, in many situations, competitive or elite athletes might be willing to accept the increased injury risk if the shoe can enhance performance. For these performance athletes, injury prevention may be a less important consideration. Emphasis can be placed on ultra-lightweight shoes which maximize energy return and do not restrict the desirable motions of the individual sport. Every sport demands a specific shoe. The process of new shoe development is similar to those categories already described: an understanding of the sport's biomechanics; an evaluation of the sport's injury patterns; prototype construction; wear-testing to insure fit, comfort, and playability; and manufacturing. Sports with large numbers of participants get the most attention, but lesser known sports demand the same detailed development. Softball, field hockey, boxing, and wrestling are, to name a few, sports which require specialty footwear. As our understanding improves in each sport, footwear technology and construction will follow.

Basketball↗