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Biomedical subjects

T Reed

Publications and source records attributed to T Reed.

At least 91 records · Page 5Linked to original sources
PubMed1989

Lower extremity peripheral vascular disease. Part 1: Scanning electron microscopy.

The surgical loss of the foot or leg is vigorously resisted by podiatrists who are committed to the conservation of limbs at risk because of peripheral vascular disease. Pathologic changes in blood vessels may, however, progress to a point where no other option is available to the patient. This study assesses amputation of the extremities and investigates tissue alterations that can be identified in diseased blood vessels implicated in these circumstances. Gross pathology and scanning electron microscopy are examined in this, the first of a two-part study.

Amputation, Surgical↗
PubMed1989

Lower extremity peripheral vascular disease. Part 2: Light and transmission electron microscopy.

In spite of the most vigorous efforts to intervene medically and surgically when peripheral vascular disease threatens a patient, amputation of the extremity may be the only option left to arrest the progression of the disease. In a previous study, the authors assessed amputations, examined gross pathology, and identified scanning electron microscopic features associated with atherosclerotic disease. In the present study, the authors discuss this disease in terms of conventional light microscopy and transmission electron microscopy.

Arteriosclerosis↗
PubMed1988

Single- vs double-lumen central venous catheters in pediatric oncology patients.

Double-lumen central venous catheters (CVCs) have been introduced recently for use in pediatric patients. The objective of our study was to determine if double-lumen CVC usage increased the possibility of infectious and mechanical complications compared with that of traditional single-lumen CVCs in a population at high risk for infection (oncology patients). Thirty pediatric patients (2.5 +/- 3.0 years old; mean +/- SD) who received single-lumen CVCs were compared with 31 patients (5.9 +/- 4.7 years old) who received double-lumen CVCs. The incidence of infectious complications was compared while controlling for potential confounding variables. Fifty-seven percent (17/30) of patients in the single-lumen group experienced bacteremia or cellulitis that required removal of six catheters compared with a rate of 52% (16/31) and nine catheter removals in the double-lumen group. Fewer manipulations occurred in the single-lumen group compared with the double-lumen group, but the incidence of mechanical complications tended to be greater. When managed carefully, double-lumen CVCs were not associated with a greater risk of infection than single-lumen CVCs.

Bacterial Infections↗
PubMed1988

The effect of knowledge of the desired outcome on dental motor performance.

Knowledge of the desired outcome of a series of movements is a critical component of motor performance, since it is used to develop the appropriate motor program and to form a basis for understanding terminal extrinsic feedback and formulating subjective reinforcement. In dentistry, information about the desired outcome is almost always disseminated in a lecture and laboratory manual, and a demonstration often is provided. However, mastery by students usually is not given the importance it deserves. The purpose of this study was to evaluate an instructional strategy designed to increase the students' knowledge of the desired outcome by determining whether such knowledge had an effect on dental motor performance. Two intact groups of first-year dental students were randomly assigned to a control or experimental treatment. The control treatment included conventional written and oral descriptions of criteria and methods for completing the occlusal (n = 93) and mesio-occlusal (n = 99) amalgam preparations. The experimental treatment directed the students' attention to critical features of tooth anatomy, and the preparation and methods for assessing performance. Results indicated statistically significant differences (p less than .05) in favor of the experimental group for both performance and degree of agreement with the instructor's evaluation of the mesio-occlusal amalgam only.

Dental Amalgam↗
PubMed1987

Plasma cholesterol variation in the National Heart, Lung and Blood Institute Twin Study.

Plasma cholesterol was measured in the fifth decade of the life of 249 pairs of monozygotic (MZ) and 262 pairs of dizygotic (DZ) World War II veteran twins and 70% of the same cohort 10 years later. There were no significant differences between the mean cholesterol values for MZ and DZ twins, and the within DZ pair mean squares were significantly larger than the within MZ pair mean squares for all of the cholesterol variables measured. However, the DZ twins were found to have greater total variance, positive skewness, and leptokurtosis than the MZ twins for total and high-density lipoprotein cholesterol, and the total/high-density ratio. Comparisons with published data revealed that the variance of DZ twins was similar to that of singletons while the MZ twins have smaller total variance, perhaps owing to a missing component of variation. Hypotheses for the source of the differences in the zygosity distributions are proposed including environmental influences (pre- or post-natal and within- or among-families), genetic differences, and selection at the time of induction into the armed services. Because of the differences in total variance of the two zygosities it is difficult to know which estimates of genetic variance or heritability have the least bias. However, these data provide clues that may lead to further understanding of sources of plasma cholesterol variation that could be important to the future understanding of risk for coronary heart disease.

Cholesterol↗
PubMed1987

Effects of indomethacin and (+/-)-propranolol on the cardiovascular and renin responses to vasoactive intestinal polypeptide (VIP) infusion in man.

The mechanisms of the cardiovascular and renin responses to vasoactive intestinal polypeptide (VIP) are unclear. Rabbit studies suggest that VIP-induced tachycardia is largely beta-adrenoceptor mediated, but that the renin response may be partially prostaglandin-dependent. To examine the relative importance of prostaglandins and reflex sympathetic activation in the haemodynamic and renin responses to VIP infusion in man, we completed two randomised single-blind crossover studies in two groups of six healthy male volunteers (aged 24-35 years). We recorded the effects of indomethacin and propranolol pretreatment on VIP-related changes in heart rate (HR), blood pressure (BP), forearm vascular resistance (FVR), plasma renin activity (PRA), plasma noradrenaline (PNA) and plasma arginine vasopressin (AVP) concentrations. Intravenous VIP (calculated dose: 6 pmol kg-1 min-1) produced cutaneous flushing, increased HR and PRA, decreased FVR, but did not alter mean arterial BP or AVP levels. Indomethacin (375 mg over 3 days) lowered basal PRA and propranolol (circa 40 mg i.v. over 60 min) decreased resting HR and increased FVR. Although indomethacin and propranolol reduced the absolute rise in PRA and HR, respectively, during VIP infusion, the percentage changes were no different from control. Neither drug altered the flush response to VIP and propranolol did not affect the fall in FVR. We conclude that the measured cardiovascular responses to VIP infusion in man are probably direct and do not involve a significant contribution from reflex sympathetic stimulation, nor prostaglandin release.

Adult↗
PubMed1986

Sudden cardiac death in Air Force recruits. A 20-year review.

We reviewed the clinical and autopsy records of the 19 sudden cardiac deaths that occurred among the 1,606,167 US Air Force healthy, medically screened recruits (90% male; 17 to 28 years old) during a 42-day basic training period between 1965 and 1985. Sixteen (all male) died suddenly of underlying structural heart disease, whereas no anatomic cause of death was identified in the remaining three. Thirty-two nonsudden, noncardiac deaths occurred during the same period, and only two had structural heart disease. Strenuous physical exertion was associated with sudden death in 17 of 19 cases (0.017 deaths per 50,000 exercise-hours), and the most frequent underlying etiology was myocarditis. Sudden cardiac death, a rare event in healthy young adults, is usually associated with exertion.

Adolescent↗
PubMed1986

Family history of cancer related to cholesterol level in young adults.

Cancer family history was quantified in 229 subjects (122 female, 107 male) screened for total serum cholesterol as seventh graders in 1972-1973 and repeated nine years later as young adults. Division of the subjects on the basis of cholesterol quintile resulted in significantly lower cancer family history scores in participants with persistently low total serum cholesterol levels and a significant excess of cancer mortality in parents and grandparents of young adult males with high-density lipoprotein (HDL) levels in the upper quintile. A trend toward increased cancer in families of young adults who were smokers was independent of the cholesterol levels. It is suggested that such a quantification of family history score will be more useful than simply designating the family history as positive or negative in future modeling schemes for predicting risk.

Adolescent↗
PubMed1986

Young adult cholesterol as a predictor of familial ischemic heart disease.

Family history for ischemic heart disease (IHD) was quantified from 229 questionnaires returned by the parents of young adults who had their total serum cholesterol levels determined as seventh graders in 1972-1973 and again 9 years later. The participants were divided into low- or high-cholesterol groups using quintiles. There were nonsignificant trends for higher prevalence of IHD in the families of individuals, principally the male participants, with persistently high total serum cholesterol levels; an excess of IHD in families of young adults with reduced high-density lipoprotein cholesterol (HDL); and a deficit of IHD in families of high-HDL participants. There was a significant interaction in family history scores between HDL and total cholesterol, such that there was an excess of IHD prevalence in families of individuals with high total cholesterol and low HDL levels, and significantly lower IHD prevalence in families of young adults with high total cholesterol and high HDL levels. Among individuals with low total cholesterol, lower family history scores were found in those with lower HDL levels.

Adult↗
PubMed1986

Protein deficiency in premature infants receiving parenteral nutrition.

A classical finding of protein deficiency is hair depigmentation, or the flag sign. To determine the clinical conditions that predispose ill premature infants to the development of protein deficiency, we compared the clinical courses and nutritional histories of premature infants receiving parenteral nutrition who developed the flag sign (group F), with those of a matched control group (Group C). Occurrences of necrotizing enterocolitis (NEC) and consequent surgery were significantly higher in group F than in group C (p less than 0.002 and p less than 0.005, respectively). No differences were found in the mean (+/- SD) administration of amino acids (group F, 2.5 +/- 0.2 g X kg X day vs group C, 2.4 +/- 0.4) and total energy (83.4 +/- 13.4 kcal X kg X day vs 83.6 +/- 11.1, respectively). Mean serum albumin levels (2.6 +/- 0.4 g/dL vs 2.6 +/- 0.5, respectively) also were similar. Because infants in both groups received recommended amounts of protein, results suggest that infants who have NEC, and surgery as a consequence of NEC, require more protein than is presently recommended.

Enteral Nutrition↗
PubMed1986

The comparison of myocardial dysfunction in three forms of experimental septic shock.

A rabbit model of septic shock was used to determine if myocardial dysfunction is a common component of shock due to diverse neonatal pathogens, and prostaglandins modulate septic myocardial dysfunction. The infusion of heat-killed Escherichia coli (group I), Haemophilus influenzae (group II), or Staphylococcus epidermidis (group III) produced significant decreases in the first derivative of left ventricular pressure with respect to time (p less than 0.05). Each organism also produced significant changes in mean arterial pressure, cardiac output, and heart rate, while pulmonary artery pressure was altered in groups I and III. Saline-infused control animals (group IV) exhibited no significant changes in any hemodynamic variable. Blood gas variables were not significantly changed in any group. These cardiovascular changes appeared dependent on arachidonic acid metabolism since indomethacin pretreatment prevented the cardiovascular changes induced by bacterial infusion. These results suggest that septic myocardial dysfunction is a common component of gram-negative and gram-positive septic shock, and that myocardial dysfunction is modulated by prostaglandin products.

Animals↗
PubMed1986

Continuous knowledge of results and psychomotor skill acquisition.

In preclinical dentistry, precise terminal knowledge of results (KR) typically is provided by an instructor when the student has completed all or a portion of a preparation. A contemporary model of psychomotor learning implies that performance can be improved if continual precise KR also is available. This investigation compared a traditional instructional format that provided instructor-generated terminal KR with one that also trained students to generate continual KR using two sections of an operative laboratory (n = 55 each). The dependent variable was student performance on occlusal and mesio-occlusal amalgam preparations. Students in the experimental group significantly outperformed those in the control group on both preparations.

Dental Amalgam↗