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Biomedical subjects

H Evans

Publications and source records attributed to H Evans.

At least 91 records · Page 5Linked to original sources

Bone and muscle atrophy with suspension of the rat.

A modification of the Morey tail suspension model was used to determine atrophic responses of rat bone and muscle with 14-90 days unloading of the hindlimbs. Bone uptake of methylene diphosphonate followed a phasic pattern similar to changes in bone formation rate in immobilized dogs and rats. Increased uptake at 60 days (P = 0.01, femur) indicated an increased bone metabolism. Regional densitometry demonstrated a preferential loss of bone mineral in the trabecular mass (P = 0.02) at 30 days and in the cortical shaft by 90 days (P = 0.03). Maximal muscle atrophy occurred within 14-30 days. The gastrocnemius was less severely affected by suspension than by immobilization techniques, whereas the soleus atrophied (by weight) similarly, suggesting that muscle atrophy in the suspension model is distinctly different from immobilization atrophy. One significant response of skeletal muscle to suspension was an altered blood distribution. Muscle blood distribution changes reflect the hypodynamic state of muscle that continues to contract but probably at an altered rate in response to altered functional demands.

Animals↗

Prevention of bronchopulmonary dysplasia by administration of bovine superoxide dismutase in preterm infants with respiratory distress syndrome.

The effectiveness of bovine superoxide dismutase (SOD) in the prevention of bronchopulmonary dysplasia was evaluated in a prospective double-blind controlled study in 45 neonates (mean gestational age 28.7 weeks, mean weight 1154 gm) with severe respiratory distress syndrome. All were ventilator dependent with FiO2 greater than or equal to 0.7 at 24 hours of age. Either bovine SOD (0.25 mg/kg) or saline solution was administered subcutaneously every 12 hours according to random selection until patients could be maintained in room air without ventilatory or continuous positive airway pressure (CPAP) support. SOD levels were detected in all patients given treatment. Mean peak values at 4 hours after dose ranged from 0.15 micrograms/ml (dose 1) to 0.45 micrograms/ml (dose 10). The drug was well tolerated, and no side effects were detected. Among the 31 survivors (SOD 14, placebo 17) radiologic evidence of BPD was significantly less in patients given SOD (3/14 vs 12/17, P = 0.008). Clinical signs of bronchopulmonary dysplasia (wheezing, pneumonia) were less in patients given SOD (3/14 vs 11/17, P = 0.019). Patients given SOD required fewer days of CPAP (P less than 0.003). There were no differences in days of O2 therapy, intermittent positive pressure breathing, or incidence and severity of patent ductus arteriosus or intraventricular hemorrhage. This preliminary study suggests that SOD may be helpful in reducing the severity of bronchopulmonary dysplasia in infants with respiratory distress syndrome.

Animals↗

High resolution bone mineral densitometry with a gamma camera.

A technique is described by which the regional distribution of bone mineral can be determined in bone samples from small animals. The technique employs an Anger camera interfaced to a medical computer. High resolution (less than 1 mm) imaging is possible by producing magnified images of the bone samples. Regional densitometry of femurs from oophorectomised and bone grafted rats demonstrated significant heterogenity of bone mineral loss.

Animals↗

Partial duplication for the short arm of chromosome 2 : the 2p23 to pter syndrome.

A 32 week, small for gestational age neonate was found to have partial duplication of the short arm of chromosome 2 (2p23 to pter). This duplication was due to a paternal balanced translocation [46,XY,t(2;20)(p23;q13)]. Peculiar facies with prominent eyes, low set ears and anteverted nostrils was apparent. A PDA with congestive heart failure occurred in the first weeks of life. The patient also had a marked diastasis recti, hemivertebrae, long tapering fingers and rocker bottom feet. The propositus was similar to the 14 cases of 2p duplication previously reported. It appears that duplication of the distal end of 2p (2p23 to pter), with or without deletion, should be classified as duplication (2p) syndrome.

Abnormalities, Multiple↗

Safety and plasma concentrations of bovine superoxide dismutase administered to human premature infants.

The safety and plasma concentrations of bovine superoxide dismutase (SOD), potentially useful in prevention of bronchopulmonary dysplasia, were evaluated in 19 prematures with severe IRDS. All were respirator dependent and required FiO2 greater than 0.7 at 24 h of age. Subcutaneous tests (0.1 mg/kg) and treatment doses (0.25 mg/kg) did not induce wheal and flare or systemic reactions. No abnormalities in serum electrolytes, calcium, glucose, creatinine concentrations, complete blood and platelet counts were noted. Following dose 1, SOD was detectable in all patients at 1 1/2 h and rose slowly to a peak at 4-8 h. Mean levels remained between 0.2 and 0.36 micrograms/ml during the 12-hour interval between doses. Similar responses resulted following doses 2-5 with mean levels between 0.36 and 0.68 micrograms/ml. SOD levels varied directly with serum creatinine levels obtained at the time of SOD administration but other factors such as skin perfusion were not controlled. The present study demonstrates that SOD at a dose of 0.25 mg/kg s.c. can be administered safely to prematures with severe IRDS and resulted in levels associated with therapeutic effects in adults.

Animals↗

Evaluation of modified gowning procedures in a neonatal intensive care unit.

The effect of modified gowning techniques in a neonatal intensive care unit was evaluated. During alternate two-month intervals, no gowns were worn over street clothes in patient care areas by staff or visitors. Mortality and infections rates during these "modified" gowning intervals were the same as during the gowning periods. However, the incidence of necrotizing enterocolitis was significantly greater in the modified gowning periods (7/353) than in the gowning periods (1/371). An expansion of this one-year study to include another year showed an even greater effect. The prevalence of bacteria at three anatomic sites (nares, umbilicus, and groin) on days 2, 4, 7, 10, 14, 21, and 28 of hospitalization was comparable between those studied during modified gowning and gowning intervals. Exceptions were the significantly increased prevalence of Staphylococcus epidermidis in the groin (days 21 and 28) during gowning and S aureus in the nares (day 28) during modified gowning periods.

Bacterial Infections↗

Duplication 3q: severe manifestations in an infant with duplication of a short segment of 3q.

A patient with duplication of a short segment of 3q (3q21 leads to 26) without apparent deletion of 3 or of other chromosomes provided a further opportunity to study manifestations of this abnormality. The proposita had a broad nasal bridge, anteverted nostrils, webbed neck, and clinodactyly V in addition to congenital heart disease, limb abnormalities, cleft palate, and severe developmental delay. The infant did not have the hirsutism and synophrys present in other cases.

Abnormalities, Multiple↗