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Biomedical subjects

S A Greene

Publications and source records attributed to S A Greene.

At least 55 records · Page 3Linked to original sources
PubMed1993

Metabolic effects of growth hormone treatment: an early predictor of growth response?

Fourteen children receiving one year of recombinant human growth hormone (rhGH) treatment underwent measurement of serial changes in body composition (measured by skinfold thickness, bioelectrical impedance, and H2(18)O dilution), resting energy expenditure (REE, estimated by ventilated hood indirect calorimetry), and total free living daily energy expenditure (TEE, measured by the doubly labelled water technique). Mean height velocity increased from 4.9 to 8.6 cm/year after six months of treatment. Fat free mass (FFM) increased more during the first six weeks (24.4 g/day) than from six to 26 weeks of treatment (6.8 g/day); fat mass decreased by 7.2 g/day and 1.1 g/day respectively. The six week increase in REE (kJ/day) was maintained after six months of treatment, though expressed per kilogram FFM (kJ/kgFFM/day), returned to pretreatment values by three months. Height velocity increases at six months correlated with six week changes in fat mass measured by skinfold thickness and REE, though use of this relationship to predict growth response in individuals is limited by the wide 95% prediction intervals. No significant changes in growth, body composition, or energy expenditure were observed between six and 12 months of treatment, in either patients who had initially responded well to treatment or those who were poor initial responders to treatment and who had their dose of rhGH doubled after six months.

Adolescent↗
PubMed1993

Antagonism by flumazenil of midazolam-induced changes in quantitative electroencephalographic data from isoflurane-anesthetized dogs.

Quantitative electroencephalography (QEEG) was assessed in 5 dogs anesthetized with 1.6% end-tidal concentration of isoflurane and after subsequent administration of the benzodiazepine midazolam (0.2 mg/kg of body weight, IV). Ventilation was controlled to maintain normocapnia. Effect of the benzodiazepine antagonist, flumazenil (0.04 mg/kg, IV), on QEEG in midazolam-isoflurane-anesthetized dogs was determined. Heart rate, arterial blood pressure, esophageal temperature, arterial pH and blood gas tensions, end-tidal CO2 concentration, and end-tidal isoflurane concentration were monitored throughout the study. A 21-lead linked-ear montage was used for recording the EEG data. Quantitative EEG data were stored on an optical disk for later analysis. Values for absolute power of EEG were determined for delta-, theta-, alpha-, and beta-frequencies. Cardiovascular variables remained stable throughout the study. Midazolam administration was associated with decreased absolute power in all frequencies of EEG at all electrode sites. Administration of flumazenil antagonized midazolam-induced decreased absolute power of EEG in all frequencies at all electrode sites. We conclude that QEEG provides a noninvasive, objective measure of midazolam- and flumazenil-induced changes in cortical activity during isoflurane anesthesia.

Anesthesia, General↗
PubMed1992

Effects of oral testosterone undecanoate on growth, body composition, strength and energy expenditure of adolescent boys.

OBJECTIVE: We determined the effect of 3 months of daily, 40 mg oral testosterone undecanoate on growth, body composition, hand grip and quadriceps muscle strength, and total free-living daily energy expenditure in boys with constitutionally delayed puberty. DESIGN: Double blind, placebo controlled study. PATIENTS: Eighteen boys with constitutionally delayed puberty, mean (SD) age 13.2 (1.6) years. MEASUREMENTS: Body composition measurements were made by skinfold thickness, bioelectrical impedance and stable isotope dilution (H2(18)O) methods. Energy expenditure was assessed by the doubly-labelled water (2H2(18)O) technique. RESULTS: Height velocity increased from 5.4 (0.8) to 8.1 (0.6) cm/year (P < 0.05) in the 3 months after active therapy. Fat-free mass increased more with therapy (2.7 (0.3) kg) over the 6-month study period than with placebo (1.7 (0.4) kg, P < 0.5). Height velocity increases correlated with daily increases in fat-free mass (r = 0.68, P = 0.005) in the study group as a whole. Energy expenditure and muscle strength increased similarly in both groups. Predicted adult height decreased in the group which was treated with testosterone undecanoate. CONCLUSIONS: Testosterone undecanoate (40 mg daily for 3 months) significantly increased height velocity and fat-free mass velocities after 6 months but not muscle strength, endurance or total daily energy expenditure.

Administration, Oral↗
PubMed1992

Quantitative electroencephalography for measurement of central nervous system responses to diazepam and the benzodiazepine antagonist, flumazenil, in isoflurane-anaesthetized dogs.

Quantitative EEG was assessed in six dogs anaesthetized with 1.8% end-tidal isoflurane concentration and following diazepam (0.2 mg/kg i.v.) administration. Ventilation was controlled to maintain normocapnia. Five dogs were subsequently given the benzodiazepine antagonist, flumazenil (0.04 mg/kg i.v.), and quantitative EEG was recorded. One dog received a saline injection following diazepam (as a control) and quantitative EEG was recorded for an additional 2.5 h. Heart rate, arterial blood pressure, esophageal temperature, arterial pH and blood gas tensions, end-tidal CO2 tension and end-tidal isoflurane concentration were monitored throughout the study. A 21 lead linked-ear montage was used for recording EEG. Quantitative EEG data were stored on an optical disc for analysis at a later date. Values for absolute power of EEG were determined for theta, delta, alpha, and beta frequencies. Cardiovascular parameters remained stable throughout the study. Diazepam administration was associated with decreased absolute power in all frequencies of EEG at all electrode sites. The duration of diazepam-induced decreased absolute power of EEG was at least 3 h in one dog. Administration of flumazenil antagonized diazepam-induced decreased absolute power of EEG in all frequencies at all electrode sites. We conclude that quantitative EEG provides a relatively non-invasive, objective measure of diazepam- and flumazenil-induced changes in cortical activity during isoflurane anaesthesia.

Anesthesia, Inhalation↗
PubMed1992

Body fat and overweight among children and adolescents with diabetes mellitus.

Body composition was assessed in 68 children and adolescents with diabetes mellitus. Body fat was measured by skinfold thickness and the results were compared with those obtained by bioelectrical impedance methods (r = 0.76, p less than 0.001). Percentage body fat from skinfold thickness estimations was 12-38%. Girls appeared to be most at risk of obesity during puberty with mean body fat 31%, significantly greater than in prepubertal girls (22%, p = 0.001) and pubertal boys (21%, p less than 0.001). Body fat increased progressively through puberty in girls, with those in late puberty (stages 4 and 5) having significantly more percentage body fat than those in earlier puberty (stages 2 and 3, p less than 0.001). Those in late puberty also received significantly more insulin per kilogram body weight (p = 0.05) and had higher HbA1 levels (p less than 0.05) than prepubertal girls.

Adipose Tissue↗
PubMed1991

Increased proximal tubular reabsorption of sodium in childhood diabetes mellitus.

Type 1 diabetes mellitus is associated with an increase in total exchangeable body sodium. To delineate a site of possible altered sodium handling, proximal tubular sodium reabsorption (PTRNa) was measured in 30 diabetic children, age 12.0 (range 7-16) yr, duration of diabetes 4.5 (range 0.2-12) yr, and compared with 10 non-diabetic children, age 10.0 (range 8.6-12.5) yr. PTRNa was calculated from the fractional clearance of lithium, which was determined from a single blood sample and a random untimed urine sample, taken between 0700 and 0830 h at home, fasting, before insulin therapy. PTRNa was significantly increased in the diabetic children compared with the non-diabetic children (81.6(SE 1.0) vs 74.2(2.6)%, p = 0.014). There was no relationship of PTRNa with age, duration of diabetes, metabolic control (glycosylated haemoglobin, plasma and urinary glucose, plasma lactate), or urinary protein excretion (albumin, N-acetyl-beta-D-glucosaminidase). Elevated sodium reabsorption in the proximal renal tubule may account for the high total exchangeable body sodium found in Type 1 diabetic patients.

Adolescent↗
PubMed1991

Body water measurement in growth disorders: a comparison of bioelectrical impedance and skinfold thickness techniques with isotope dilution.

Total body water was estimated as part of the assessment of body composition in children with growth disorders, using the newly commercially available method of bioelectrical impedance. This was undertaken to compare the precision and accuracy of the results with those derived from skinfold thickness against measurement of stable isotopically labelled water (H2(18)O) dilution as a standard. The comparisons were carried out to see to what extent the impedance method could be applied with confidence to assessment of children with growth disorders. Total body water was derived from impedance (I) using an association with height (Ht2/I). Impedance and skinfold thickness estimates of total body water were equally precise when compared with values obtained from H2(18)O dilution (limits of agreement -1.9 to +1.3 and -1.7 to +2.0 kg respectively). The mean intraobserver coefficient of variation for repeat measurements of impedance was 0.9% compared with 4.6% for skinfold thickness with an interobserver coefficient of variation for impedance of 2.8%. Bioelectrical impedance estimation of body composition is likely to be of value in the growth clinic when expertise in measurement of skinfold thickness is limited or repeated measurements are to be undertaken by different observers.

Body Composition↗
PubMed1991

Changes in body composition and energy expenditure after six weeks' growth hormone treatment.

Changes in body composition and energy expenditure were assessed in 15 children after six weeks of human growth hormone (hGH) treatment. Body composition measurements were made by stable isotope labelled water (H2(18)O) dilution, bioelectrical impedance, and skinfold thickness techniques. Energy expenditure was assessed both by indirect ventilated hood calorimetry (resting energy expenditure) and the stable isotope doubly labelled water (2H2(18)O) technique (free living daily total energy expenditure). Mean increases in weight of 0.96 kg and fat free mass of 1.37 kg and a mean decrease in fat mass of 0.41 kg were observed. Significant increases both in resting energy expenditure and free living daily energy expenditure were detected. Absolute changes in fat mass and resting energy expenditure were correlated. The data suggest (i) that the increase in the fat free mass is the most significant early clinical measure of hGH response and (ii) that hGH increases the metabolic activity of the fat free mass. Monitoring such changes may be predictive of the efficacy of hGH in promoting growth.

Adolescent↗
PubMed1991

Expansion of clinical pharmacy services through staff development.

A program that trains and uses staff pharmacists for clinical services is described. A position was created that is filled by staff pharmacists on six-week rotations. All full-time pharmacists may participate; they work under the direction and supervision of clinical pharmacists. Basic responsibilities in the rotation include responding to drug information requests, assisting with drug-use evaluation and adverse drug experience programs, assisting with research, writing and editing for newsletters, participating in staff development programs, and reviewing and clarifying drug orders for the skilled-nursing facility. About 60% of eligible pharmacists have participated in this program. The pharmacists have gained new practice skills, greater opportunity for career enhancement, and improved attitudes toward work and colleagues, and the department has been able to provide more clinical services. The focus of the rotation is now being changed from performing clinical tasks to assuming more responsibility for patient outcomes related to drug therapy. A rotating clinical position has enabled staff pharmacists to gain additional nondispensing skills and contribute to the development and maintenance of clinical services.

Education, Pharmacy, Continuing↗
PubMed1991

Cardiovascular effects of halothane anesthesia after diazepam and ketamine administration in beavers (Castor canadensis) during spontaneous or controlled ventilation.

Fourteen adult beavers (Castor canadensis) weighing 16.5 +/- 4.14 kg (mean +/- SD) were anesthetized for surgical implantation of radio telemetry devices. Beavers were anesthetized with diazepam (0.1 mg/kg) and ketamine (25 mg/kg) administered IM, which provided smooth anesthetic induction and facilitated tracheal intubation. Anesthesia was maintained with halothane in oxygen via a semiclosed circle anesthetic circuit. Values for heart rate, respiratory rate, esophageal temperature, direct arterial blood pressure, end-tidal halothane concentration, and end-tidal CO2 tension were recorded every 15 minutes during the surgical procedure. Arterial blood samples were collected every 30 minutes to determine pH, PaO2, and PaCO2. Values for plasma bicarbonate, total CO2, and base excess were calculated. Ventilation was spontaneous in 7 beavers and controlled to maintain normocapnia (PaCO2 approx 40 mm of Hg) in 7 others. Vaporizer settings were adjusted to maintain a light surgical plane of anesthesia. Throughout the surgical procedure, all beavers had mean arterial pressure less than 60 mm of Hg and esophageal temperature less than 35 C. Mean values for arterial pH, end-tidal CO2, PaO2, and PaCO2 were significantly (P less than 0.05) different in spontaneously ventilating beavers, compared with those in which ventilation was controlled. Respiratory acidosis during halothane anesthesia was observed in spontaneously ventilating beavers, but not in beavers maintained with controlled ventilation. All beavers recovered unremarkably from anesthesia.

Acid-Base Equilibrium↗
PubMed1991

Quantitative electroencephalography in dogs anesthetized with 2.0% end-tidal concentration of isoflurane anesthesia.

Quantitative electroencephalography was assessed in dogs under controlled, 2% end-tidal isoflurane anesthetic conditions, and each variable at each electrode site was tested for normal distribution. With the quantitative electroencephalographic system used, 16 values for each of 21 electrode sites were evaluated. Absolute power ratios also were evaluated. The methods for quantitative electroencephalographic recording and analysis appear to be readily adaptable to the dog. Most of the data do not conform to a normal distribution. Therefore, distribution-free nonparametric statistics should be used when looking for differences under experimental or clinical conditions. Quantitative electroencephalography appears to be a sensitive noninvasive method that could be used to evaluate brain function under anesthetic, clinical, and experimental settings.

Acid-Base Equilibrium↗
PubMed1990

Oxandrolone for delayed puberty in boys taking long-term steroid therapy for renal disease.

Eleven boys, mean age 15.3 years (range 13.2-17.5), with pubertal delay in association with steroid therapy for steroid-sensitive nephrotic syndrome and following renal transplantation were treated with oxandrolone 2.5 mg daily for a mean of 0.50 years (range 0.34-0.61). Mean growth velocity increased from 3.9 cm/year (range 1.1-6.3) to 6.1 cm/year (range 2.0-14.4) and was maintained at 6.1 cm/year (range 0.4-10.2) (P less than 0.05). However, there was no significant difference in growth between the treated boys and age- and puberty-matched controls. Elevation of blood cyclosporin A and creatinine levels occurred in the transplant patients. Oxandrolone may initiate a pubertal growth spurt in patients taking steroid therapy for renal disease, but should be used with extreme caution because of potential side-effects.

Adolescent↗
PubMed1990

Cerebral oedema complicating diabetic ketoacidosis.

Four children presented with cerebral oedema secondary to diabetic ketoacidosis, each of whom had a different clinical picture and time of onset of neurological deterioration. No single factor emerged as the cause of the cerebral oedema, but disturbances in brain water balance appeared to be already operative at the time of presentation with ketoacidosis. Irregularities in treatment may exacerbate these disturbances, leading to frank cerebral oedema. Diagnosis of this dangerous complication of diabetic ketoacidosis depends on clinical awareness; the diagnosis may be confirmed by CT scan. Management remains empirical.

Adolescent↗
PubMed1990

Procedural compliance and clinical outcome associated with therapeutic interchange of extended-spectrum penicillins.

The degree of procedural compliance and the clinical outcome associated with a therapeutic interchange of extended-spectrum penicillins were assessed. Pharmacists conducted a concurrent chart review on all patients receiving mezlocillin as a therapeutic alternative for piperacillin or ticarcillin over a five-month period. The pharmacists assessed whether (1) the pharmacy appropriately dispensed mezlocillin when orders were written for piperacillin or ticarcillin, (2) physicians and nurses were properly notified of the therapeutic interchange, and (3) the bacterial isolates were susceptible to mezlocillin. Pharmacists and physicians evaluated clinical outcomes of all patients receiving mezlocillin through a retrospective chart review and classified the responses as "success," "failure," or "indeterminate." Fifty-one orders for piperacillin were written during the study period, and mezlocillin was selected as a therapeutic alternative in all cases. No orders for ticarcillin were written. Proper notification was made to nurses and physicians in 98% and 65% of cases, respectively. No mezlocillin-resistant gram-negative bacteria were found. Eighty-three courses of therapy were reviewed for clinical outcome; 68 were classified as successes, 0 were failures, and 15 were indeterminate. The cost savings after nine months of therapeutic interchange of mezlocillin for piperacillin was $6600. This study indicates that the pharmacy made a proper therapeutic interchange of mezlocillin for piperacillin and followed the correct procedure for notification of the nursing staff. However, more effort is needed to ensure communication with the prescribing physicians.

Bacteria↗
PubMed1990

Cardiovascular effects of butorphanol in halothane-anesthetized dogs.

Cardiovascular effects of butorphanol (0.2 mg/kg of body weight, IV) and responses associated with subsequent administration of naloxone (0.04 mg/kg, IV) were studied in halothane (1.2% end-tidal concentration)-anesthetized dogs. Transient, but statistically significant (P less than 0.05), decreases in heart rate, mean and diastolic arterial blood pressures, and rate-pressure product were observed after butorphanol administration. Cardiac index, stroke volume, and systemic vascular resistance did not change significantly. Except for the decrease in heart rate, changes in the values of the cardiovascular variables measured after butorphanol administration did not appear to be clinically relevant. Sixty minutes after butorphanol administration, naloxone was given. Statistically significant (P less than 0.05) increases in heart rate, arterial blood pressures, cardiac index, and rate-pressure product, along with dysrhythmias were observed. Stroke volume and systemic vascular resistance remained unchanged after administration of naloxone. Naloxone administration was associated with changes indicative of increased myocardial oxygen consumption.

Anesthesia, Inhalation↗
PubMed1989

Cardiovascular effects of butorphanol administration in isoflurane-O2 anesthetized healthy dogs.

Cardiovascular consequences of butorphanol tartrate (0.2 mg/kg of body weight, IV) administration during isoflurane (1.7% end-tidal concentration) anesthesia were determined in mechanically ventilated healthy dogs. Butorphanol administration caused significant (P less than or equal to 0.05) reductions in mean, systolic, and diastolic arterial blood pressures; cardiac output; and rate-pressure product.

Acid-Base Equilibrium↗