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Biomedical subjects

E J Peters

Publications and source records attributed to E J Peters.

At least 37 records · Page 2Linked to original sources
PubMed1998

Acute bacterial meningitis in a developing country: diagnosis related mortality among paediatric patients.

OBJECTIVES: To evaluate the effect of late diagnosis and other factors on outcome of paediatric bacterial meningitis (BM) and recommend appropriate intervention. DESIGN: Case series. SETTING: University of Calabar Teaching Hospital, Calabar, Nigeria. SUBJECTS: 62 consecutive BM patients aged two months to 16 years admitted between 1991 and 1994. MAIN OUTCOME MEASURES: Mortality rate. RESULTS: Diagnostic difficulties experienced in 58% of cases and other factors resulted in delayed diagnosis and high mortality (20 to 47%). CONCLUSION: Only elimination of the identified inadequacies in management can significantly reduce the BM-related high mortality in developing countries.

Acute Disease↗
PubMed1998

Vibration perception threshold: are multiple sites of testing superior to single site testing on diabetic foot examination?

Vibration perception threshold (VPT) values, measured at different anatomic locations on the foot and ankle, and the time to assess VPT and sensory perception using two difference modalities in 102 diabetic patients were compared. VPT was evaluated at the great toe, fifth metatarsal and ankle. Differences in VPT at these three sites, in addition to differences in duration of testing comparing single site (great toe) to multiple sites, and to standard SWMF testing were assessed. No significant difference in VPT between the great toe and fifth metatarsal was found for patients both with and without loss of protective sensation (LOPS). Mean VPT was significantly higher at the ankle compared with both the great toes and fifth metatarsals. However, the difference between ankle and great toe was not significant between patients with and without LOPS [3.9 +/- 11.2 (12%) vs. 3.0 +/- 10.8 (16%) volts, respectively, p > 0.6]. Testing of one site took approximately half the time of Semmes-Weinstein 10-gram monofilament wire SWMF testing (40.5 +/- 16.9 vs. 22.3 +/- 9.1 seconds, p < 0.01) and less than one third the time of three-site VPT testing (10.5 +/- 26.1 vs. 22.3 +/- 9.1 seconds, p < 0.01). There may not be a significant practical benefit in multiple site VPT testing when compared with single site testing on the great toe alone. The value of multiple site testing is further called into question when one notes that the great toe VPT remains the only site tested for sensitivity and specificity for ulceration.

Diabetic Foot↗
PubMed1997

Current issues in living donor nephrectomy.

Of 96 consecutive renal transplants in 2 years, 50 (52%) were living donor grafts. Donor demographics, treatment plans, length of stay (LOS), charges, and complications were reviewed. Donors included 27 women and 23 men aged 22 to 61 (mean 42.2) years; 33 were living related and 17 living unrelated donors. Racial distribution included 1 Hispanic, 2 Asian, 8 black, and 39 white donors. Pretransplant evaluation defined renal anatomy and function (minimal creatinine clearance 75 cc/min). Hospital admission occurred the morning of donation. Nephrectomy under general anesthesia entailed an anterior flank, extra-retroperitoneal approach (no rib resection); and postoperative epidural pain control was standard. Progressive early ambulation and pulmonary self-care optimized recovery. The 50 donors were hospitalized for 2 (n = 7), 3 (n = 18), 4 (n = 15), 5 (n = 6), and 6-8 (n = 4) days (mean LOS: 3.74 +/- 0.17, range 2-8 days). The mean charge for donor hospitalization was $15,415 +/- $397 (range $10,808-$29,579). One major intraoperative hemorrhage required transfusion; 1 patient was readmitted for wound drainage and pneumonia treated medically. While 40 of 50 patients (80%) were hospitalized for 4 days or less, there was no readmission because of short hospital stay. One early graft loss (3 days) occurred from technical problems; all others gained excellent life sustaining function. Three additional kidneys failed from rejection, noncompliance, and systemic coagulopathy. One recipient died at 8 months (CVA) with normal renal function. Current strategies for successful living kidney donation are thorough patient and family education, ambulatory preoperative testing, morning of surgery admission, and discharge planning beginning before hospitalization. Excellent outcomes may be accompanied by a brief LOS, epidural pain management, and liberal use of willing and healthy related and unrelated living donors.

Adult↗
PubMed1994

Randomized placebo-controlled trial of isotretinoin in chemoprevention of bronchial squamous metaplasia.

PURPOSE: Retinoids have proven chemopreventive efficacy in both preclinical and clinical studies. This trial was designed to confirm the finding of an earlier uncontrolled trial that the synthetic retinoid etretinate had major activity in reversing squamous metaplasia found in the bronchial epithelium of chronic smokers. PATIENTS AND METHODS: We prospectively evaluated 152 smokers with bronchoscopy and obtained biopsies from six sites. Subjects with dysplasia and/or a metaplasia index of greater than 15% were randomly assigned to receive either 1 mg/kg isotretinoin or placebo daily for 6 months. Of 86 subjects randomized (41 isotretinoin, 45 placebo), 69 were reevaluated at the completion of treatment. RESULTS: In the group as a whole, the metaplasia index decreased over time from a mean +/- SE of 35.8% +/- 2.7% at baseline to 28.1% +/- 3.3% at the completion of treatment (P = .01) by repeated measures analysis of variance [ANOVA]); a reduction in the metaplasia index (> 8%) was noted in both isotretinoin and placebo groups (19 of 35 [54.3%] and 20 of 34 [58.8%], respectively). Complete reversal of squamous metaplasia was noted in nine subjects from each group. However, the magnitudes of the mean metaplasia index changes did not differ significantly in the two treatment groups. In both groups, smoking cessation resulted in significant declines in the extent of squamous metaplasia, whereas no significant change in metaplasia index was found among those who continued to smoke. CONCLUSION: Squamous metaplasia was frequently observed in bronchial biopsy samples from chronic smokers. From this study, we conclude that isotretinoin has no effect on squamous metaplasia, a potential intermediate end point of bronchial carcinogenesis. Although determining the exact role of isotretinoin in lung cancer prevention requires further study, the finding that there was a significant decrease in squamous metaplasia in the placebo group emphasizes the critical importance of a placebo-controlled study design in chemoprevention trials using intermediate end points.

Adult↗
PubMed1993

Squamous metaplasia of the bronchial mucosa and its relationship to smoking.

We performed flexible fiberoptic bronchoscopy (FFB) on 106 heavy cigarette smokers. Six bronchial biopsy specimens, obtained from the carina and five major bronchi, were screened for squamous metaplasia. Individual biopsy specimens were sectioned into 4-microns sections, and a metaplasia index (MI), or percentage of sections containing squamous metaplasia, was determined. Metaplasia was noted at one or more biopsy sites in 66 of 99 subjects (seven were excluded from the analysis). Twenty-five percent of the subjects showed metaplasia at three or more biopsy sites, and one subject had metaplasia on all six biopsy specimens. The presence of squamous metaplasia varied from 40.4 percent in the right lower lobe to 15.3 percent in the left upper lobe. The subjects were grouped into simple categories based on the number of packs smoked per day and the pack-year history of smoking. Subjects who smoked more than two packs per day (n = 11) had the highest MI (37.4 +/- 4.9 percent, mean +/- SEM). Fifty-seven subjects smoked more than one pack per day but fewer than or equal to two packs per day, and they had a mean MI of 22.3 +/- 2.9 percent. Subjects who smoked one pack per day or less (n = 31) had a mean MI of only 12.9 +/- 2.8 percent. The MI of those who smoked more than two packs per day was significantly greater than the MI of those who smoked one pack per day or less (p < or = 0.003). While the MI varied from 12.9 +/- 3.5 percent in subjects who had smoked less than 20 pack-years to a maximum of 29.1 +/- 4.5 percent in those who had smoked greater than 60 pack-years, no statistically significant difference was detected between these two groups. Thus, we conclude that heavy tobacco use is associated with important alterations of bronchial mucosa. Furthermore, the intensity of tobacco use (packs per day) rather than the number of pack-years appears to be the more important factor in promoting squamous metaplasia of the bronchial mucosa.

Adult↗
PubMed1992

Micronuclei in bronchial biopsy specimens from heavy smokers: characterization of an intermediate marker of lung carcinogenesis.

Bronchial micronuclei, small fragments of extra-nuclear DNA formed during cell division, provide a non-specific but quantifiable marker of DNA damage. Micronuclei have been used to assess carcinogen exposure and as an intermediate endpoint in chemoprevention trials. As part of an ongoing chemoprevention trial, heavy smokers underwent screening bronchoscopy, with biopsies taken at 6 standardized sites. Micronuclei counts were obtained for each site in each of the 40 volunteers found to have squamous metaplasia. Unlike squamous metaplasia, the average micronuclei counts among these heavy smokers were not associated with smoking history. Micronuclei counts were also not associated with the presence or extent of metaplasia. A striking degree of intra-individual variability was observed by comparing the micronuclei counts from different biopsy sites within individuals. The findings suggest that use of micronuclei from single sites may be misleading as a marker of carcinogen exposure or as an estimate of cancer risk. Serial measurements in individuals may provide the most useful information concerning carcinogenic exposure and the impact of chemopreventive agents.

Adult↗
PubMed1992

Exercise testing in the evaluation of patients at high risk for complications from lung resection.

Exercise testing was performed on 37 patients with resectable lung lesions who were deemed inoperable because of any of the following risk factors: (1) FEV1 less than or equal to 40 percent of predicted; (2) radionuclide calculated postlobectomy FEV1 less than or equal to 33 percent of predicted; or (3) arterial PCO2 greater than or equal to 45 mm Hg. The patients who reached a peak level of oxygen consumption during exercise (VO2Peak) of greater than or equal to 15 ml/kg/min were offered surgical treatment. Patients with a VO2Peak of less than 15 ml/kg/min were referred for nonsurgical management and excluded from the study. Eight patients underwent lung resection. Their pulmonary function revealed a severe obstructive lung defect with a group mean predicted FEV1 of 40 +/- 6 percent, an FEV1/FVC ratio of 47 +/- 10, a radionuclide calculated postlobectomy FEV1 of 31 +/- 4 percent, and a mean arterial PCO2 of 44 +/- 6 mm Hg. No relationship was found between each patient's exercise performance and spirometric function. Six of the patients had an uncomplicated postoperative course. Two patients had complications but no patient died as a result of surgery or postoperative complications. All patients were discharged from the hospital within 22 days (mean = 9.8 days). We conclude that exercise testing is a useful complement to conventional cardiopulmonary evaluation used in selecting patients for lung resection.

Aged↗
PubMed1991

Estimating energy requirements in burned children: a new approach derived from measurements of resting energy expenditure.

We examined the determinants of resting energy expenditure (REE) in 127 observations in 56 burned children. Predicted basal energy expenditure (PBEE), body surface area (BSA), and body weight correlated significantly with REE (r2 = 0.76). Days postburn and burn size (% BSA burned) only accounted for 21%, and 24% of the variation in the elevation in REE above PBEE. The single most powerful predictor of REE was PBEE (REE = 1.29 x PBEE); addition of other variables did not improve the prediction. When our recently described activity factor of 1.2 for burn patients is used, the data predict that the average energy requirement to maintain energy balance is 1.55 x PBEE, which is significantly lower than commonly used recommendations, especially for larger burns. The energy required to ensure that 95% of patients achieve energy balance was (1.55 x PBEE) + (2.39 xoff+PBEE0.75), approximately equal to 2 x PBEE. Because the equations presented are derived from measurements of energy expenditure, they represent the most valid approach to estimating energy requirements.

Adolescent↗
PubMed1991

Lipolytic response to metabolic stress in critically ill patients.

OBJECTIVE: To measure whole-body lipolysis and fatty acid re-esterification in critically ill patients. DESIGN: The rates of appearance of glycerol and palmitic acid in blood plasma were measured by infusing stable isotope tracers [2H5]glycerol and [1-13C]palmitic acid, respectively. Energy expenditure was measured by indirect calorimetry. SETTING: Medical ICU of The University of Texas Medical Branch Hospital, a university-based referral center. PATIENTS: Five uninjured critically ill patients. Four patients were hospitalized because of respiratory insufficiency and one because of myocardial infarction. Three patients died during their hospitalization. INTERVENTIONS: Metabolic studies were performed in each patient after an overnight (12-hr) fast. MEASUREMENTS AND MAIN RESULTS: Mean +/- SE glycerol and fatty acid rates of appearance were 4.5 +/- 1.0 and 11.5 +/- 0.8 mumol/kg.min, respectively. The ratio of fatty acid to glycerol rate of appearance was 2.9 +/- 0.5. Resting energy expenditure was 132 +/- 6% of predicted. CONCLUSIONS: An accelerated rate of lipolysis is part of the metabolic response to severe stress, regardless of its etiology. Because the rate of fatty acid release far exceeded energy requirements, fatty acids that were not oxidized as fuel were re-esterified to triglyceride, presumably in the liver.

Acute Disease↗
PubMed1991

Effect of short-term fasting on the lipolytic response to theophylline.

We investigated the hypothesis that the increase in lipolysis that occurs in short-term (86-h) fasting is due to a decreased inhibitory influence of adenosine. In normal volunteers who fasted for 14 and 86 h, the response to adenosine receptor blockade was assessed by the infusion of theophylline at a rate sufficient to produce plasma concentrations (30 microM) that blocked adenosine receptors but that were well below the threshold for inhibition of phosphodiesterase. Lipolysis was assessed by determining the rate of appearance of glycerol using D-5-glycerol infusion. Fatty acid flux was also determined by means of [1-13C]palmitate infusion, and total fatty acid oxidation was determined by indirect calorimetry. There was a mild stimulatory effect of theophylline on lipolysis at 14 h. After the subjects fasted for 86 h, theophylline infusion caused a much greater increase in both lipolysis and fatty acid oxidation. These results suggest that the inhibitory effect of adenosine on lipolysis is increased during short-term fasting.

Adult↗
PubMed1991

Miliary pulmonary infection caused by Mycobacterium terrae in an autologous bone marrow transplant patient.

A 64-year-old woman with ovarian carcinoma that had been treated with high-dose chemotherapy and autologous bone marrow transplantation presented with a maculopapular rash on the extremities and miliary infiltrates evident on chest roentgenogram. Transbronchial biopsy specimens revealed caseating granulomas, and cultures grew Mycobacterium terrae. Six weeks after therapy with isoniazid, rifampin, and pyrazinamide was begun, her rash and pulmonary infiltrates had cleared, despite the in vitro resistance to these drugs and continued spread of her carcinoma. This case suggests that spontaneous resolution may be part of the natural history of M terrae infections.

Bone Marrow Transplantation↗
PubMed1990

Bronchial micronuclei as a marker of an early stage of carcinogenesis in the human tracheobronchial epithelium.

In the bronchial epithelium, smoking initiates a multistep process that first appears histologically as premalignant squamous metaplasia/dysplasia, a biological predecessor of squamous-cell lung cancer. Reflecting chromosomal damage from a carcinogenic insult, micronuclei may reveal earlier events in the carcinogenic sequence. We prospectively evaluated and correlated micronucleus count, histology (index of metaplasia) and smoking exposure in 35 consecutive subjects (9 active smokers, 10 previous smokers and 16 never-smokers) undergoing diagnostic bronchoscopy. Samples for micronuclei and histological evaluation were taken from the main carinal mucosa in each subject for site-specific comparisons. The median and mean micronucleus counts per 1,000 cells were significantly higher in active smokers than in non-smokers (subjects who had never smoked and previous smokers): median counts were 3.7 vs. 1.4, p = 0.03; mean counts were 4.7 vs. 1.9, p = 0.01. There was no significant difference, however, in micronucleus counts between subjects who had never smoked and previous smokers. Bronchial metaplasia and smoking history were not associated. Our findings suggest that micronuclei are a readily quantitated, early intermediate-endpoint marker for detecting tobacco-initiated tracheobronchial carcinogenesis.

Adult↗
PubMed1990

Effect of dietary protein on bed-rest-related changes in whole-body-protein synthesis.

To determine whether increasing dietary protein could exert a beneficial effect on bed-rest-related protein catabolism, two groups of normal subjects were subjected to 7 d of bed rest while taking isocaloric diets containing either 0.6 or 1.0 g protein.kg body wt-1.d-1. Whole-body-leucine turnover, leucine oxidation, and nonoxidative leucine disappearance were measured by use of a constant infusion of 1-13C-leucine. Before bed rest, the higher-protein diet resulted in a 14% decrease in whole-body-leucine turnover and a 28% decrease in leucine oxidation, but net nonoxidative leucine disappearance was not different on the two diets. A 24% decrease in nonoxidative leucine disappearance was seen in subjects assigned to the lower-protein diet, who had been on bed rest, but on the higher-protein diet, leucine kinetics were unchanged by bed rest. Bed rest does not cause an increase in whole-body-protein breakdown, but decreased whole-body-protein synthesis is demonstrable when dietary protein is low. This decrease is prevented by a higher dietary amount of protein.

Adult↗
PubMed1990

The relationship between gluconeogenic substrate supply and glucose production in humans.

The relationship between gluconeogenic precursor supply and glucose production has been investigated in 14-h and 86-h fasted humans. In protocols 1 and 2 [6,6-2H]glucose and [15N2]urea were infused to measure glucose and urea production rates (Ra) in response to infusions of glycerol and alanine. In protocol 3 first [15N]alanine, [3-13C]lactate, and [6,6-2H]glucose were infused before and during administration of dichloroacetate (DCA) to determine the response of glucose Ra to decreased fluxes of pyruvate, alanine, and lactate, then alanine was infused with DCA and glucose Ra measured. After a 14-h fast, neither alanine nor glycerol increased glucose Ra. Basal glucose Ra decreased by one-third after 86 h of fasting, yet glycerol and alanine infusions had no effect on glucose Ra. Glycerol always reduced urea Ra (P less than 0.05), suggesting that glycerol competitively inhibited gluconeogenesis from amino acids. DCA decreased the fluxes of pyruvate, alanine (P less than 0.01), and glucose Ra (P less than 0.01), which was prevented by alanine infusion. These findings suggest that 1) the reduction in glucose Ra after an 86-h fast is not because of a shortage of gluconeogenic substrate; 2) nonetheless, the importance of precursor supply to maintain basal glucose Ra is confirmed by the response to DCA; 3) an excess of one gluconeogenic substrate inhibits gluconeogenesis from others.

Adult↗
PubMed1990

Total energy expenditure in burned children using the doubly labeled water technique.

Total energy expenditure (TEE) was measured in 15 burned children with the doubly labeled water technique. Application of the technique in burned children required evaluation of potential errors resulting from nutritional intake altering background enrichments during studies and from the high rate of water turnover relative to CO2 production. Five studies were discarded because of these potential problems. TEE was 1.33 +/- 0.27 times predicted basal energy expenditure (BEE), and in studies where resting energy expenditure (REE) was simultaneously measured, TEE was 1.18 +/- 0.17 times REE, which in turn was 1.16 +/- 0.10 times predicted BEE. TEE was significantly correlated with measured REE (r2 = 0.92) but not with predicted BEE. These studies substantiate the advantage of measuring REE to predict TEE in severely burned patients as opposed to relying on standardized equations. Therefore we recommend that optimal nutritional support will be achieved in convalescent burned children by multiplying REE by an activity factor of 1.2.

Adolescent↗
PubMed1989

Prevalence of acanthosis nigricans in an unselected population.

PURPOSE: The intent of this study was to determine, in an unselected population, the prevalence of the hyperinsulinemia-associated skin lesion, acanthosis nigricans. SUBJECTS AND METHODS: The posterior neck of every child in the sixth and eighth grades of the public schools of Galveston, Texas, was personally examined by the investigators during a state-mandated school health survey. A total of 1,412 children were examined. RESULTS: The data for each child examined included the absence or presence of acanthosis nigricans, height, weight, age, sex, and ethnic background. A subset of the children with the skin lesion also had fasting plasma insulin levels measured. Acanthosis nigricans was present in 7.1% of the 1,412 children examined. The skin lesion was equally distributed between boys and girls and was most common among children with severe obesity. The condition was present in two of 440 white non-Hispanics, 19 of 343 Hispanics, and 80 of 601 blacks examined. The fasting plasma insulin concentrations measured in some of these children and in previously evaluated subjects strongly correlate with the presence and severity of the acanthosis nigricans skin lesion. CONCLUSIONS: This skin lesion is much more common than previously believed and has a dramatic ethnic predisposition. We conclude that the high prevalence of this skin lesion further suggests that insulin resistance and hyperinsulinemia, with all of their serious medical implications, are also highly prevalent.

Acanthosis Nigricans↗
PubMed1989

Effect of short- and long-term beta-adrenergic blockade on lipolysis during fasting in humans.

Stable isotope tracers and indirect calorimetry were used to evaluate the importance of beta-adrenergic stimulation of lipolysis and triglyceride-fatty acid cycling during fasting in healthy human volunteers. Each subject was studied after 12 and 84 h of fasting both with and without propranolol infusion (protocol 1) and when oral propranolol treatment was given throughout fasting (protocol 2). In protocol 1, the rates of appearance of glycerol and palmitic acid increased from 3.04 +/- 0.19 and 1.78 +/- 0.17 mumol.kg lean body mass-1.min-1, respectively, after 12 h of fasting to 5.28 +/- 0.31 and 3.47 +/- 0.15 mumol.kg lean body mass-1.min-1, respectively, after 84 h of fasting (P less than 0.005). The rate of triglyceride-fatty acid cycling increased from 97 +/- 8 to 169 +/- 5 mumol/min (P less than 0.005). Intravenous propranolol infusion decreased the rate of lipolysis after both 12 and 84 h of fasting, but the magnitude of the antilipolytic effect was much greater after 84 h (P less than 0.005). In protocol 2, the rate of lipolysis and triglyceride-fatty acid cycling was still increased by fasting despite beta-adrenergic blockade with oral propranolol. This study demonstrates that beta-adrenergic stimulation contributes to the mobilization of fat during fasting. However, other mechanism(s) can increase lipolysis and triglyceride-fatty acid cycling when beta-adrenergic receptors are continuously blocked.

Adult↗