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Biomedical subjects

R L Reed

Publications and source records attributed to R L Reed.

At least 19 recordsLinked to original sources
PubMed2004

Correlation of quantitative ultrasound parameters of the calcaneus with bone density of the spine and hip in women with prevalent hypovitaminosis D.

Quantitative ultrasound (QUS) of the calcaneus correlates modestly with axial dual-energy X-ray absorptiometry (DXA). Because bone mineral density (BMD) might be influenced by vitamin D status, we assessed the correlation between both techniques in 56 Arabian women, a population with high prevalence of hypovitaminosis D. The speed of sound (SOS), broadband ultrasound attenuation (BUA), and estimated BMD of the right calcaneus were determined by QUS. Spine and right hip BMD were measured by DXA scan. The serum 25-hydroxyvitamin D (25OHD) level was measured by radioimmunoassay. The correlations of QUS parameters (estimated calcaneal BMD, BUA, and SOS) with spine and hip BMD were modest (r = 0.50, r = 0.53, r = 0.41 for the spine and r = 0.54, r = 0.56, and r = 0.46 for the hip, respectively; p < 0.01 for all comparisons), but stronger in postmenopausal women. All postmenopausal women with low estimated calcaneal BMD (T-score pound -1) had a T-score pound -1 by DXA of the spine or hip. Of the 21 premenopausal women with spine or hip T-score pound -1 who had 25OHD measurements, 20 (95.2%) had levels below 50 nmol/L and 12 (57%) had levels below 30 nmol/L. The subgroup with 25OHD < 30 nmol/L had significantly lower spine (p < 0.01) and hip BMD (p < 0.05) than the subgroup with 25OHD >/= 30 nmol/L. QUS parameters were not significantly different between the two subgroups. The QUS and DXA correlated modestly well in women with prevalent hypovitaminosis D. QUS could be used in postmenopausal women with hypovitaminosis D to identify those at risk for osteoporotic fracture.

Absorptiometry, Photon↗
PubMed2003

Quantitative ultrasound of the calcaneus in Arabian women: relation to anthropometric and lifestyle factors.

OBJECTIVES: To determine factors influencing quantitative ultrasound (QUS) parameters of the calcaneus in a population-based sample of United Arab Emirates (UAE) women, and to compare QUS parameters of the calcaneus for healthy young UAE women with the manufacturer's reference ranges for other populations. METHODS: All subjects completed a questionnaire on reproductive and life style factors. Height and weight were measured, and body composition was determined by bioelectric impedence. Estimated bone mineral density (BMD), Speed of sound (SOS), broadband ultrasound attenuation (BUA) and quantitative ultrasound index (QUI) of the right calcaneus were determined by Sahara ultrasound. RESULTS: In premenopausal women (n=330), age, weight, body mass index (BMI), lean weight, fat weight, education, age at menarche, and number of pregnancies, correlated significantly with QUS parameters. Multiple regression analysis showed that age at menarche, number of pregnancies, and BMI, were the best predictors of QUS parameters although these factors explained only small amounts of the variance (R(2)=0.05). In postmenopausal women (n=81), age, BMI and physical activity were the best predictors of BUA (R(2)=0.35), SOS (R(2)=0.39), and QUI (R(2)=0.43). Mean estimated BMD, QUI and SOS for healthy young UAE women were significantly lower than the manufacturer's reference ranges for U.S. Caucasian, European Caucasian, and Chinese Asian healthy young women of the same age range (P<0.001 for all comparisons). Mean BUA was not significantly different, however. CONCLUSIONS: Menopausal status, age, BMI and physical activity are strong predictors of QUS parameters of the calcaneus in Arabian women. Healthy young Arabian women have lower estimated calcaneal BMD compared with the manufacturer's reference ranges for other populations.

Absorptiometry, Photon↗
PubMed2003

Comparison of growth and performance in upland and lowland switchgrass types to water and nitrogen stress.

The objective of the study was to examine lowland (Alamo and Kanlow) and upland (Blackwell and Caddo) cultivars of switchgrass (Panicum virgatum L.) for differences in response to water deficit and nitrogen fertilizer. Cultivars were grown in pots with fritted clay at two water levels: well watered and deficit conditions (-0.1 and -1.0 MPa) and two nitrogen levels (10 and 100 kg ha(-1)). Nitrogen determined growth potential of the cultivars more than water availability. The lowland cultivars produced greater biomass yields than upland cultivars. However, upland cultivars showed a smaller response to drought stress. Under water stress conditions all cultivars exhibited a higher leaf percentage of total dry matter (DM), with the upland cultivars having the highest leaf percentage of total DM. Nitrogen proved to have more of an effect on single-leaf photosynthesis rates than water. Alamo demonstrated the greatest biomass production among all cultivars. The differences found between the two lowland cultivars suggest that Alamo would be better suited for forage and biomass production in central Texas, being a higher producer under drought and non-drought conditions than Kanlow as well as upland cultivars.

Geography↗
PubMed2001

Carotid thromboendarterectomy for recent total occlusion of the internal carotid artery.

BACKGROUND: The efficacy of emergency carotid thromboendarterectomy (CTEA) for acute internal carotid artery (ICA) thrombosis has been questioned. We evaluated the use of CTEA in patients with recent ICA occlusion. METHODS: From August 1989 to December 1999 patients who underwent urgent CTEA for recent ICA thrombosis were retrospectively evaluated. Patient data analyzed included age, sex, comorbid risk factors, diagnostic evaluation, operative procedure, and long-term follow-up with clinical assessment and carotid duplex scan. Neurologic status was evaluated with the Modified Rankin Scale (MRS) before the operation, immediately after the operation, and at 3- to 6-months' follow-up. RESULTS: Twenty-nine patients underwent emergency ipsilateral CTEA for acute ICA thrombosis over the last 10 years. The average age of the patients was 69.9 +/- 1.7 years, and 66% were men. Patient risk factors included diabetes (7 [24%]), hypertension (21 [72%]), coronary artery disease (8 [29%]), and history of tobacco abuse (20 [69%]). Presenting symptoms included cerebrovascular accident (7 [24%]), transient ischemic attack (nonamaurosis) (10 [34%]), crescendo transient ischemic attack (7 [24%]), stroke in evolution (2 [7%]), and amaurosis fugax (3 [10%]). Diagnostic evaluation included computed tomographic scan (29 [100%]), magnetic resonance imaging/magnetic resonance angiography (4 [14%]), duplex scan evaluation of the carotid arteries (23 [79%]), and cerebral angiography (18 [64%]). Antegrade flow in the ICA was successfully established in 24 (83%) of 29 patients and confirmed with intraoperative angiography or duplex sonography. Postoperative morbidity included 2 hematomas (7%), 4 transient cranial nerve deficits (14%), and 1 conversion to hemorrhagic stroke (3.6%), which resulted in the only death (3.6%). MRS scores averaged 3.4 +/- 0.2 preoperatively. Follow-up averaging 74.1 +/- 21 months (range, 3-140 months) was obtained in 27 (93%) patients. Improvement or deterioration was defined as a change in MRS +/- 1. Immediately postoperatively, 14 (48%) patients were improved, 2 (7%) deteriorated, and 13 (45%) had no change. At 3 to 6 months, 20 (74%) of 27 patients were improved, seven (26%) had no change, and none deteriorated. Of patients with successful CTEA, 23 (96%) of 24 had a patent ICA on follow-up duplex scan evaluation, and there was no evidence of recurrent ipsilateral neurologic events at an average of 49 months. CONCLUSION: These data support an aggressive early surgical intervention for acute ICA thrombosis in carefully selected patients. In the previous decade we reported a 46% success rate for establishing antegrade flow in the ICA long term. Data from this decade show a 79% (P =.0114) success rate for establishing antegrade flow long term in all patients undergoing emergency CTEA. New and improved imaging modalities have allowed better patient selection, resulting in improved outcomes.

Acute Disease↗
PubMed2001

A clinical trial of chronic care diabetic clinics in general practice in the United Arab Emirates: a preliminary analysis.

Control of diabetes mellitus is a high priority for primary health care systems. One innovative method of diabetes care delivery is the use of structured diabetes care in primary care. This includes the use of chronic care diabetes clinics or mini-clinics operated by general practitioners in primary care. There is limited experience with this model in non-Western settings. This study sought to evaluate a multi-component structured approach to diabetes care in primary care including chronic care diabetes clinics in a newly developed country in the Arabian Gulf. The study design used was a controlled before-after methodology. Three primary health centers were chosen for the intervention with six of the remaining clinics in a Health District being used as controls. A multifaceted intervention was initiated in the intervention clinics composed of chronic care diabetes clinics, a diabetic flow chart, and educational programs for clinic nurses and doctors and patients. The study intervention took place over a period of 18 months with three diabetic outcomes (fasting blood glucose, blood pressure and cholesterol) and adherence to seven diabetes guidelines being compared for the year prior to the intervention and during the last 12 months of the intervention period. Knowledge and satisfaction questionnaires were also administered to intervention and control subjects at the end of the study. In this study, 219 subjects were enrolled (130 males and 89 females). They had a mean age of 51.6 years and a mean of 3.1 years of formal education. Of these 109 were enrolled in one of three clinics that had a chronic care diabetes clinic and 110 were enrolled in one of the six control clinics. Subjects had diabetes for a mean of 7.8 +/- 4.8 years and the majority was treated with pharmacological therapy. Baseline characteristics in the intervention and the control clinics were similar with the exception of younger age (p = 0.01) and a trend for more males (p = 0.06) in the intervention clinics. There was a statistically insignificant change noted with the intervention in the three clinical outcomes studied (fasting blood glucose, blood pressure and cholesterol) both in comparison to the control group before and after and within the intervention group. However most changes noted were in the expected direction of improvement; six of the seven guidelines were statistically improved in the intervention group when compared with the control group. Within the intervention group, adherence with five of seven guidelines was also statistically significantly increased with the remaining guidelines showing a trend in favor of improvement (fasting blood glucose measurements (p = 0.07) and urine determinations for protein (p = 0.07)). Knowledge questionnaire scores were similar between the intervention and control groups on completion of the study but 2 of 4 items on a satisfaction scale were statistically significantly higher in the intervention group. The intervention described in this setting was successful in improving adherence to diabetes guidelines and increased some aspects of satisfaction with diabetes care. The intervention did not result in a statistically significant improvement in clinical outcomes but changes noted were in the expected direction of improvement. The significant improvement in adherence to diabetes guidelines suggests that this intervention is a promising model for diabetes care for newly developed countries.

Blood Glucose↗
PubMed2000

Contemporary issues with bacterial infection in the intensive care unit.

Nosocomial infection in the critically ill results from defects in the intrinsic barriers to microbial invasion. The diagnosis is complicated by an inability to perform an adequate physical examination in a patient with several compounding findings, usually necessitating sophisticated technologies to aid in the diagnosis. Pneumonia, line sepsis, urosepsis, sinusitis, endocarditis, peritonitis, and acalculous cholecystitis are the more common infections that challenge the care of the critically ill. Antibiotic therapy is adjunctive to efforts to preserve the barrier, but should be started early, should be targeted as specifically as possible to the offending organisms, and should be dosed adequately to ensure an effective concentration in the infected tissue.

Anti-Bacterial Agents↗
PubMed1999

Managed care for older people: a primer for the geriatrician.

Managed care for older people is growing at a very rapid rate. Many geriatricians and primary care providers are interested in this area but have limited sources of information to guide their decision-making about whether to participate in these programs. This review provides a basic overview of managed care for older people, including plan types and roles that geriatricians may choose in participating in these programs. Risk and value are central concepts that impact managed care of this population. Several changes in Medicare Managed Care have occurred with the passage by Congress of the Balanced Budget Act of 1997. Geriatricians are strongly encouraged to participate in managed care as it offers the potential for improved models of care delivery for older adults.

Aged↗
PubMed1998

Glutathione measurement in human plasma. Evaluation of sample collection, storage and derivatization conditions for analysis of dansyl derivatives by HPLC.

Literature values for human plasma GSH vary over 10-fold despite the use of apparently valid analytical procedures for GSH measurement. The purpose of this study was to develop a procedure to minimize error in sample collection, processing and storage that could contribute to such differences. HPLC with fluorescence detection of dansyl derivatives was used for quantification. The results show that collection of blood with a butterfly needle and syringe reduces overestimation due to limited hemolysis and that use of a preservation solution designed to inhibit autooxidation and enzymatic degradation allows quantitative recovery of both GSH and GSSG. Stability tests showed that non-derivatized samples were stable for at least 2 months at - 80 degrees while dansyl derivatives were stable in the dark at 0-4 degrees for 12 months. Results from 59 healthy individuals (20-43 years) provided a mean (+/-1 SD) GSH value of 2.09+/-1.14 micromolar.

Blood Specimen Collection↗
PubMed1998

Glutathione in human plasma: decline in association with aging, age-related macular degeneration, and diabetes.

Blood samples were analyzed for GSH and GSH redox state in 40 age-related macular degeneration (ARMD) patients (> 60 y), 33 non-ARMD diabetic patients (> 60 years), 27 similarly aged non-ARMD and nondiabetic individuals (> 60 years), and 19 younger individuals (< 60 years) without ARMD or diabetes. Results showed a significantly lower plasma GSH in older individuals (ARMD, diabetes, and controls) than in younger individuals (p < .01). Total GSH (GSHt) obtained following treatment with dithiothreitol was significantly lower only in diabetic cases (p < .05) but also approached significance for ARMD cases (p = .089). Estimation of redox potential indicated that the plasma GSH pool is considerably more oxidized in all of the older groups. Analyses of whole blood GSH showed that GSH was significantly lower in diabetic cases compared to the other groups, but did not reveal any difference associated with age or ARMD. In contrast, GSSG in whole blood was significantly higher in the older groups compared to the younger controls. The results suggest that in studies of age-related pathologies, oxidation of GSH may be a more important parameter than a decline in pool size, while in specific pathologies such as diabetes, both oxidation and a decline in pool size may be important.

Adult↗
PubMed1998

"The demographics of trauma in 1995" revisited: an assessment of the accuracy and utility of trauma predictions.

OBJECTIVE: In 1987, the article "The Demographics of Trauma in 1995" (DT95) attempted to predict the future needs of trauma centers based on changing population distributions. This article foresaw a relative increase in the number of injuries to the elderly and a relative decrease in total injuries. Based on these predictions, the paper recommended increasing the capabilities of existing trauma centers rather than developing new facilities. We compared these predictions to actual experience to validate this use of demographic data in trauma system planning. METHODS: The predictions of DT95 were compared with the available population and injury data from the U.S. Census Bureau and the Centers for Disease Control and Prevention using age-related cohort analysis. RESULTS: As predicted, the highest-growing segment was the population older than 65 years, which increased 18% to 33.5 million. Also, the rate of injury-related deaths per 100,000 decreased from 61.20 in 1985 to 57.98 in 1995. The number of fatal motor vehicle crashes decreased from 45,958 in 1985 to 43,484 in 1995. Against predictions, the number of firearm deaths in 1994 increased from 31,566 to 35,957. Accurate predictions were thus made for most trauma demographic categories using a combination of census predictions and existing trauma demographic patterns. The increase in firearm deaths, however, was not anticipated using these sources and suggested the potential development of a more violent society. CONCLUSIONS: Demographic projections assist in predicting the number and type of future injuries. Sociologic and economic factors also need to be considered in any predictive determinations of the true demand for trauma centers.

Adolescent↗
PubMed1998

Endoscopic placement of jejunal feeding catheters in critically ill patients by a "push" technique.

BACKGROUND: Enteral nutrition is less expensive and often preferred to parenteral nutrition in the critically ill or injured patient. Gastric feedings are poorly tolerated in some patients, however, and postpyloric access is frequently difficult to obtain. In this report, we describe our experience with a new technique for bedside endoscopic placement of small intestinal feeding tubes. METHODS: Using both prospective and retrospective analysis, we studied our results with endoscopically placed postpyloric feeding tubes in intensive care unit (ICU) patients. In this method, a 7F nasobiliary tube is passed via an endoscope into the proximal small bowel by a "push" technique. We recorded the demographic data of the patients, the feeding regimens subsequently used for these patients, and the overall feasibility and complications of the procedures themselves. RESULTS: The technique was performed on 71 occasions in 61 ICU patients. The entire procedure averaged 29 minutes in a prospectively evaluated subset of patients. Small intestinal cannulation was successful in every case, including cases in which fluoroscopic attempts had failed. No complications developed from placement of the feeding tubes. CONCLUSION: This report demonstrates that our bedside method of endoscopic placement of proximal small-bowel feeding tubes may be safely and expediently performed in ICU patients. Although not yet formally compared with other techniques, this procedure may have some advantages over traditional methods of small-bowel feeding tube placement.

Adolescent↗
PubMed1998

Blunt vascular injuries of the head and neck: is heparinization necessary?

BACKGROUND: Blunt vascular injuries to the head and neck (BHVI) represent some of the most devastating and morbid injuries seen by a trauma surgeon. This series reviewed the experience of a single institution to determine if diagnostic and therapeutic guidelines can be established for these uncommon injuries. In particular, the utility of anticoagulation in the treatment of these injuries is examined. METHODS: The institutional trauma registry of a single state-designated Level I trauma center was examined for patients with BHVI. Patients were identified and their charts reviewed individually with regard to multiple data points including the type of injury, its presentation, the treatment of the injury, and the functional outcome of the patient. RESULTS: Twenty-nine BHVI in 23 patients were reviewed from 1989 to 1997. No mortalities were noted. Among the injuries noted were 14 internal carotid artery dissections and 8 carotid artery tears. Thirteen patients had accompanying closed head injuries. Ten patients were diagnosed after an abnormal neurologic examination, and eight others were diagnosed after having carotid canal fractures. Heparin was started within 48 hours of injury in 4 patients (17%) and was used in a total of 12 patients (52%). No patient worsened neurologically after diagnosis independent of the use of heparin. Thirteen patients (57%) had no or minimal deficits upon discharge. CONCLUSION: BHVI represent a serious cause of morbidity in the patient with multiple injuries. Patients with closed head injuries and carotid canal fractures appear most at risk. A multicenter, randomized trial involving antiplatelet therapy, full systemic anticoagulation, or observation with a long-term functional assessment is indicated to determine the optimal management of these injuries.

Adolescent↗