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Biomedical subjects

W Evans

Publications and source records attributed to W Evans.

At least 19 recordsLinked to original sources
PubMed1995

Reverse transcription-polymerase chain reaction detection of collagen transcripts in healing human wounds.

The aim of this study was to analyse the expression of COl1A1, COl1A2 and COl3A1 in 6 mm diameter punch biopsies obtained from human wounds. Total RNA was isolated from biopsies taken from Sacrococcygeal pilonidal sinus excision cavities at weekly intervals between surgery and clinical closure. cDNAs were generated from the RNA using reverse transcriptase and polymerase chain reaction (PCR) amplifications performed with oligonucleotide primer pairs specific for regions of the COl1A1, COl1A2 and COl3A1 genes. The expression of these three genes was demonstrated throughout the course of healing on 36 biopsies taken from nine patients between surgery and clinical closure. Amplification bands demonstrated on cDNAs generated from 6 mm diameter biopsies were comparable in intensity and specificity with those generated from 50 mg excised scar tissue and cultured fibroblasts. The RT-PCR technique described here allows the rapid 'routine' detection of specific gene expression in 6 mm biopsies obtained from healing wounds.

Biopsy↗
PubMed1991

Leucine metabolism during fasting and exercise.

Whole body leucine kinetics were examined in seven healthy young men while in a 14-h postabsorptive state (PAS) and after a 3.5-day fast (FS). Subjects received a primed constant intravenous infusion of L-[1-13C]leucine while resting for 3 h and then while exercising on a cycle ergometer at 45% maximal O2 uptake to exhaustion. Blood samples drawn during isotopic steady state were analyzed for 13C enrichment of leucine and alpha-ketoisocaproic acid, and expired gas samples were analyzed for 13CO2. Resting leucine flux was higher in the FS, and there was a slight increase in leucine oxidation. During exercise, leucine flux did not differ between PAS and FS but leucine oxidation rose markedly. In the FS, leucine oxidation was 25 +/- 7 (SD) mumol.kg-1.h-1 at rest and rose to 75 +/- 21 mumol.kg-1.h-1 during exercise; in the PAS, oxidation was 20 +/- 5 mumol.kg-1.h-1 at rest and 52 +/- 17 mumol.kg-1.h-1 during exercise. These data indicate that the high rate of leucine oxidation previously found during exercise was increased further by a 3.5-day fast.

Adult↗
PubMed1989

A cross-sectional prevalence study of lumbar disc degeneration in a working population.

The prevalence of lumbar degenerative discs (LDD) was determined in 38 ambulating and 21 sedentary employees of a Rocky Mountain company. Lumbar degenerative discs were identified by magnetic resonance imaging (MRI) performed with a sagittal T2 image of the lumbar spine using a .5 Tesla unit. The L5-S1 level was the most common disc with degenerative changes. Analysis of the two groups showed a significant association at the L5-S1 level between occupation and LDD, as evidenced by the ambulating females having no degenerative lumbar discs and sedentary females having a large number of degenerative discs. The males in the study did not demonstrate a significant difference in prevalence of LDD. Lumbar degenerative discs may be increased in less active females at the L5-S1 level.

Adult↗
PubMed1987

Controlled-release oral morphine sulfate in the treatment of cancer pain with pharmacokinetic correlation.

The bioavailability and clinical effects of an oral controlled-release morphine sulfate tablet, MS-contin (MSC; Purdue-Frederick, Norwalk, CT) in comparison to an immediate-release (IRMS) preparation were evaluated in normal subjects and cancer patients, respectively. The inherent slow-release character of MSC was confirmed by 2 1/2 X T1/2 absorption rate, one-half Cmax, and twice Tmax relative to IRMS. The T1/2 elimination of the two morphine preparations was similar, demonstrating insignificant risk of MSC accumulation. The difference in the mean number of side effects experienced by the control group per subject was significant (.70 for MSC and 1.26 for IRMS, P = .05) and was consistent with peak plasma morphine attenuation. The cancer patients were initially switched from their previous analgesic to four hourly IRMS and then to MSC at double the dose every eight hours. The majority had their MSC dosing interval lengthened to every 12 hours with a decrease in the total daily morphine requirement. While the mean duration on MSC was 20.5 days, many patients were followed poststudy for an extended period with no appreciable development of tolerance. Overall, MSC analgesia and side effects were perceived by the patients as superior compared with prestudy opioids. The advantage of less frequent dosing may lead to improvement of the quality of life of cancer patients.

Adult↗
PubMed1987

Ready, set, go. Wellness movement focuses business efforts on improved worker fitness, health.

From its conception in the mid-1970s to the present, attention to fitness and education regarding preventive measures has increased at a phenomenal rate. Companies are involved in the attempt to keep employees healthy and health care cost-efficient. Reduced absenteeism, less turnover, more positive work attitudes, less strain and tension, improved work performance and health-related savings are but a few of the benefits cited by those involved in maintaining healthy lifestyles. At a time when the health care industry is undergoing major cost containment efforts, it seems most reasonable to adopt a preventive mindset and be concerned with employee fitness and lifestyle programs that lead to a decrease in immediate health care utilization.

Health Promotion↗
PubMed1987

Neoplastic angioendotheliosis.

Neoplastic angioendotheliosis is a rare disease in which malignant cells are found within numerous blood vessels throughout the body in the absence of any detectable extravascular primary malignancy. The disorder has a propensity for clinical neurological involvement despite pathological evidence of systemic spread. To date 23 patients with neurological involvement have been described. This report adds a further 3 cases. There was no definite evidence to support the theory that the malignancy arises in endothelial cells; no primary extravascular tumour was found. At present a definite conclusion about the cause of the disease cannot be made.

Aged↗
PubMed1986

Metabolic and ventilatory responses to steady state exercise relative to lactate thresholds.

The metabolic and ventilatory responses to steady state submaximal exercise on the cycle ergometer were compared at four intensities in 8 healthy subjects. The trials were performed so that, after a 10 min adaptation period, power output was adjusted to maintain steady state VO2 for 30 min at values equivalent to: (1) the aerobic threshold (AeT); (2) between the aerobic and the anaerobic threshold (AeTAnT); (3) the anaerobic threshold (AnT); and (4) between the anaerobic threshold and VO2max (AnTmax). Blood lactate concentration and ventilatory equivalents for O2 and CO2 demonstrated steady state values during the last 20 min of exercise at the AeT, AeAnT and AnT intensities, but increased progressively until fatigue in the AnTmax trial (mean time = 16 min). Serum glycerol levels were significantly higher at 40 min of exercise on the AeAnT and the AnT when compared to AeT, while the respiratory exchange ratios were not significantly different from each other. Thus, metabolic and ventilatory steady state can be maintained during prolonged exercise at intensities up to and including the AnT, and fat continues to be a major fuel source when exercise intensities are increased from the AeT to the AnT in steady state conditions. The blood lactate response to exercise suggests that, for the organism as a whole, anaerobic glycolysis plays a minor role in the energy release system at exercise intensities upt to and including the AnT during steady state conditions.

Adult↗
PubMed1985

The effect of intravenous hyperalimentation on the dietary intake of patients with small cell lung cancer. A randomized trial.

In a randomized trial of 119 patients with small cell cancer of the lung, the effects of a 30-day course of central intravenous hyperalimentation (IVH) on dietary intake were evaluated. All patients underwent the same aggressive chemotherapy and radiation therapy; 57 patients received IVH and 62 served as controls. Median caloric intake prior to antineoplastic therapy was less than 1.2 times basal energy expenditure, below the maximum necessary to maintain weight. While receiving IVH, patients had increased caloric and protein intake. Once the IVH was stopped, oral intake was transiently depressed and thereafter similar to control patients. Baseline nutritional parameters, age, sex, and immediate toxicity from chemotherapy did not predict subsequent caloric insufficiency. Direct estimation of dietary intake is likely the most valuable measure in selecting patients who will need adjunctive nutritional support.

Adult↗
PubMed1985

Effects of intravenous hyperalimentation during treatment in patients with small-cell lung cancer.

One hundred nineteen patients were entered onto a randomized trial of the role of intravenous hyperalimentation (IVH) in patients with small-cell lung cancer. IVH was given during the first 30 days of induction chemotherapy to 54 patients. IVH did not effect any improvement in response or survival from therapy. In view of the lack of benefits from IVH, an analysis was made of the toxicities suffered by the 54 patients receiving IVH as well as any effects IVH might have made on chemotherapy-induced toxicity. Toxicities observed included mechanical difficulties with the catheter leading to temporary or permanent discontinuation of the IVH (11 patients), subclavian vein thrombosis (one patient), sepsis in nine patients v none of the 62 control patients, fluid overload (27 patients), hyponatremia (25 patients), and hyperglycemia requiring insulin (13 patients). Patients receiving IVH had higher granulocyte counts on days 14 and 21 of the first cycle of chemotherapy. Analysis shows that this difference is likely caused by fever and infection associated with IVH rather than any nutritional effect on granulopoiesis. In this population of patients, IVH had significant complications but did not ameliorate chemotherapy-induced toxicity and it did not effect any clinical benefit. Future studies of adjunctive nutritional therapy must consider the significant risk in this older population and must limit IVH volume or exclude patients with even mild compromise in cardiovascular functions. Further, any new trial must have a significant rationale for adjunctive use to justify the potential risks.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1984

Pharmacokinetics of etoposide (VP16) in children and adolescents with refractory solid tumors.

The clinical pharmacokinetics of etoposide were studied in eight pediatric patients with refractory solid tumors. The alpha-phase half-life, beta-phase half-life, volume of distribution, and elimination rate constant averaged 0.82 hr, 6.5 hr, 4.0 liters/sq m, and 0.25 hr-1, respectively. Noncompartmental parameters such as systemic clearance, mean residence time, and volume of distribution at steady-state averaged 20.9 ml/min/sq m, 7.8 hr, and 7.2 liters/sq m, respectively. A significant relationship between serum glutamic pyruvic transaminase and systemic clearance was observed, with patients having elevated serum glutamic pyruvic transaminase showing slower systemic clearance of etoposide. Systemic clearance, mean residence time, and beta-phase half-life of etoposide were significantly lower in those patients who had received cisplatin prior to their Phase II etoposide trial. The average pharmacokinetic values derived from these eight pediatric patients with solid tumors did not differ significantly from those previously reported in children with leukemia administered similar dosages and in adults given radioactively labeled etoposide.

Adolescent↗
PubMed1983

Clinical algorithms for prehospital cardiac care.

Algorithms for the prehospital management of cardiac arrhythmias were developed and their use by and value to paramedics evaluated. The algorithms, in booklet form, were distributed to half of the Philadelphia paramedic platoons; paramedics in the other platoons followed a narrative protocol that reflected identical contents. An arrhythmia recognition test given 18 months after the algorithm booklets were introduced showed that paramedics who received the booklets scored significantly higher in identifying life-threatening arrhythmias (p = 0.029) than did their counterparts without the booklets. Survival data for 459 patients in ventricular fibrillation treated by paramedics were collected 1 year before and 7 months after the introduction of the algorithm booklets. The paramedics using the algorithms improved their survival rate from 11.25 to 15.1 per cent, while the survival rate for patients treated by paramedics using the narrative protocols decreased from 12.4 to 7.7 per cent. The likelihood of obtaining a ratio of survival odds of this magnitude when there is no true difference is 0.092. Time-to-death was significantly different (p = 0.04) for the two groups of patients. Thus, the use of algorithm booklets as an inexpensive educational aid for paramedics is recommended.

Allied Health Personnel↗
PubMed1981

Normal computed tomograms of the brain in osteosarcoma patients treated with high-dose methotrexate.

Eighteen patients with osteosarcoma, most of whom were adolescents, were examined for abnormalities of the brain by use of computed axial tomography. These studies were performed at 15-60 months (median 47 months) after the completion of adjuvant chemotherapy, which included high-dose methotrexate, cyclophosphamide, and Adriamycin. No abnormalities were found. The results of this study, together with the absence of brain lesions in published reports in children receiving high-dose methotrexate but no cranial irradiation, indicate that delayed neurotoxicity is not a major complication of this form of therapy in older children.

Adolescent↗
PubMed1981

Recovery of left ventricular function following discontinuation of anthracycline chemotherapy in children.

Echocardiographic evaluation of left ventricular (LV) performance was performed in 41 children during and following anthracycline chemotherapy. Prior to treatment LV function was normal in all patients; LV shortening fraction was 35.2 +/- 0.7% and percent of predicted velocity of circumferential fiber shortening was 110 +/- 20%. However, the indices measured concurrent with the final anthracycline dose (mean = 308 +/- 16 mg/sq m) demonstrated a significant decline in LV function. The LV shortening fraction had decreased to 29.5 +/- 0.8% and percent of predicted velocity of circumferential fiber shortening decreased to 94 +/- 4% (P less than .01). Four of the eight patients with evidence of significant LV dysfunction had received thoracic or upper abdominal irradiation. Following cessation of anthracycline therapy, LV function improved within one to six months and had returned to normal in all but two patients, both of whom received irradiation. Echocardiography is useful for the identification of anthracycline-induced LV dysfunction. With discontinuation of further anthracycline administration the functional decline in LV performance appears to be reversible.

Adolescent↗
PubMed1979

Severity indices and their implications for emergency medical services research and evaluation.

The present paper explores the rationale for the development of severity indices and the role such indices can play in various research and evaluation situations. Concrete examples from Emergency Medical Services research and evaluation settings are used to illustrate the potential shortcomings of designs that fail to incorporate measures of severity. A short critical review of existing indices is presented, and the ways that the indices can be refined and improved, and better used to evaluate emergency care, are summarized.

Emergency Medical Services↗