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Biomedical subjects

J E Benson

Publications and source records attributed to J E Benson.

At least 19 recordsLinked to original sources
PubMed2004

Disseminated Acanthamoeba sp. infection in a dog.

Several species of free-living amoebae can cause encephalomyelitis in animals and humans. Disseminated acanthamoebiasis was diagnosed in pyogranulomatous lesions in brain, thyroid, pancreas, heart, lymph nodes, and kidney of a one-year-old dog. Acanthamoeba sp. was identified in canine tissues by conventional histology, by immunofluorescence, by cultivation of the parasite from the brain of the dog that had been stored at -70 degrees C for two months, and by PCR. The sequence obtained from the PCR product from the amoeba from the dog was compared to other sequences in the Acanthamoeba sp. ribosomal DNA database and was determined to be genotype T1, associated with other isolates of Acanthamoeba obtained from granulomatous amebic encephalitis infections in humans.

Acanthamoeba↗
PubMed2001

Effect of porcine reproductive and respiratory syndrome virus infection on the ovary and progesterone levels in third trimester pregnant sows.

Porcine reproductive and respiratory syndrome virus (PRRSV) is a common cause of reproductive failure and abortion in swine. The mechanism of abortion is not fully defined, and the effect of the virus on luteal function has not been explored. In this study, we exposed late-term pregnant swine to varied doses of PRRSV strain NADC-8 and evaluated effects on ovarian function by serial determination of plasma progesterone levels and by microscopic evaluation of ovarian pathologic alterations combined with immunohistochemistry and in situ hybridization to detect PRRSV antigen. We identified no specific trend in plasma progesterone level associated with PRRSV infection status and no microscopic ovarian lesions. PRRSV antigen was not demonstrated in ovarian tissues by immunohistochemistry or in situ hybridization at necropsy 21 days postexposure. Based on these findings, it does not appear that either a direct or an indirect effect on luteal function contributes to PRRSV-induced abortion.

Abortion, Veterinary↗
PubMed1999

The relationship in neonates between clinically measured head circumference and brain volume estimated from head CT-scans.

OBJECTIVE: To determine if the frontal-occipital head circumference correlates with brain volume on CT and to investigate correlations between the volumes of different brain subdivisions in live neonates. METHODS: Records were studied from 27 neonates with anatomically normal head CT-scans which were ordered for clinical reasons, and which were performed at Johns Hopkins Hospital. Clinical data were abstracted from medical records. Brain volumes were estimated by digitizing the structures of interest on each slice of head CT-scans. RESULTS: In this sample of 27 infants with a mean birth weight of 3000.4 +/- 668 g, mean head circumference of 33.5 +/- 1.8 cm, and mean gestational age of 37 weeks and 4 days +/- 24 days, the mean of total brain volume was 333.0 +/- 78.3 ml. The correlation between clinically measured head circumference and total brain volume was 0.55 (P < 0.003). Regression of total brain volume on head circumference and its second and third powers accounted for 43% of the variation in total brain volume. Other predictor variables, namely infant race, sex, gestational age, and maternal age, were not significant in this regression once head circumference was included. The slope of the cubic function of head circumference as a predictor of brain volume was greatest below the mean head circumference of 33.5 cm. Brain volume leveled off at head circumferences greater than the mean. CONCLUSION: Head circumference is a powerful predictor of total brain volume in the neonate: below the approximate head-circumference mean of 33.5 cm, smaller head circumference indicates smaller total brain volume.

Birth Weight↗
PubMed1999

Effect of antioxidant supplementation on urine and blood markers of oxidative stress during extended moderate-altitude training.

OBJECTIVE: To investigate the increase in oxidative stress during work at moderate altitudes due to additional energy expenditure, tissue anoxia, and UV light exposure. METHODS: Thirty US Marine Corps volunteers were divided into placebo (P) and antioxidant supplement (S) groups and tested for markers of oxidative stress before (t0), at the midpoint of (t1), and after (t2) 14 days of winter training at a moderate altitude (approximately 2700 m). The antioxidant supplement consisted of a daily dose of 20,000 IU beta-carotene, 400 IU vitamin E, 500 mg vitamin C, 100 micrograms selenium, and 30 mg zinc. The following markers of oxidative stress were measured: urine thiobarbituric acid reactive substances (TBARSs), urine hydroxynonenal (HNE), urine 8-hydrodeoxyguanosine (8-OHdG), plasma total peroxyl radical trapping potential (TRAP), and plasma lipid hydroperoxides (LPOs). Urine was collected on a 24-hr basis at t0, t1, and t2; blood samples were collected at t0 and t2. RESULTS: P group LPOs increased 30% (p < 0.05) between t0 and t2, whereas S group LPOs did not increase. Both groups exhibited significant increases in urine TBARSs, HNE, and 8-OHdG by t2. Urine TBARSs, HNE, and 8-OHdG increased between t0 and t1 in both groups, with the greater increase in the S group. The conflicting results between the plasma and urine markers of oxidative stress may be due to a time-phase relationship. CONCLUSIONS: The results of this study suggest that work in a moderate-altitude cold-weather environment is accompanied by increased oxidative stress, despite relatively high intakes of dietary and supplemental antioxidants.

Adult↗
PubMed1998

Retropsoas hernia as a cause of chronic abdominal pain: CT diagnosis.

Congenital retropsoas small bowel herniation is reported as the cause of long-standing recurrent abdominal pain in a teenage girl. Knowledge of this entity is important for differential diagnosis of abdominal pain, mass, or retroperitoneal gas and fluid, and for avoiding complications of percutaneous renal interventions.

Abdominal Pain↗
PubMed1997

Spinal abnormalities in classic bladder exstrophy.

OBJECTIVE: To determine the frequency and clinical sequelae of significant spinal malformations in children born with classic bladder exstrophy. PATIENTS AND METHODS: All patients evaluated or treated for classic bladder exstrophy at this institution were reviewed retrospectively. Radiographs or reports pertinent to the spine were retrieved and reviewed with a paediatric radiologist and all vertebral abnormalities categorized. Clinical charts of those with spinal anomalies were reviewed to determine any clinical neurological disorders associated with the radiographic findings. RESULTS: Of 423 patients with classic bladder exstrophy who were identified, 299 had radiographs or reports available for adequate review. Of these, 34 (11%) normal variants, e.g. spina bifida occulta and lumbarization or sacralization of vertebrae, were identified. Abnormalities of spinal curvature were identified in eight patients (2.7%), all with uncomplicated scoliosis. Spinal dysraphism was diagnosed in 12 patients (4%) and included myelomeningocele, lipomeningocele, scimitar sacrum, posterior laminal defects in two or more vertebrae, vertebral fusion and hemivertebrae. The one patient with myelomeningocele had clinical neurological dysfunction, giving an overall incidence of 0.3%. CONCLUSIONS: Spinal anomalies, excluding normal variants, occur in children born with classic bladder exstrophy at a rate of about 6.7%. The incidence of this association is much less than that for cloacal exstrophy. Although rare, neurological dysfunction can occur in the case of spinal dysraphism. Paediatric urologists and neurologists should be aware of this significant difference between patients with classic bladder and cloacal exstrophy to properly diagnose, evaluate and treat the attendant neurological problems.

Adolescent↗
PubMed1997

Ultrasound evaluation of piglet diaphragm function before and after fatigue.

Clinically, a noninvasive measure of diaphragm function is needed. The purpose of this study is to determine whether ultrasonography can be used to 1) quantify diaphragm function and 2) identify fatigue in a piglet model. Five piglets were anesthetized with pentobarbital sodium and halothane and studied during the following conditions: 1) baseline (spontaneous breathing); 2) baseline + CO2 [inhaled CO2 to increase arterial PCO2 to 50-60 Torr (6.6-8 kPa)]; 3) fatigue + CO2 (fatigue induced with 30 min of phrenic nerve pacing); and 4) recovery + CO2 (recovery after 1 h of mechanical ventilation). Ultrasound measurements of the posterior diaphragm were made (inspiratory mean velocity) in the transverse plane. Images were obtained from the midline, just inferior to the xiphoid process, and perpendicular to the abdomen. M-mode measures were made of the right posterior hemidiaphragm in the plane just lateral to the inferior vena cava. Abdominal and esophageal pressures were measured and transdiaphragmatic pressure (Pdi) was calculated during spontaneous (Sp) and paced (Pace) breaths. Arterial blood gases were also measured. Pdi(Sp) and Pdi(Pace) during baseline + CO2 were 8 +/- 0.7 and 49 +/- 11 cmH2O, respectively, and decreased to 6 +/- 1.0 and 27 +/- 7 cmH2O, respectively, during fatigue + CO2. Mean inspiratory velocity also decreased from 13 +/- 2 to 8 +/- 1 cm/s during these conditions. All variables returned to baseline during recovery + CO2. Ultrasonography can be used to quantify diaphragm function and identify piglet diaphragm fatigue.

Abdominal Muscles↗
PubMed1996

Nutritional aspects of amenorrhea in the female athlete triad.

Female athletes experience a high incidence of menstrual abnormalities. This has critical health consequences because amenorrheic athletes are at greater risk of developing osteopenia and bone injury compared to normally menstruating athletes or nonathletic normally cycling females. Female performers and athletes are also at risk for developing disordered eating behaviors. There appears to be a connection between menstrual dysfunction, athletic training, and disordered eating, but how they relate is not fully understood. In this paper we explore how low calorie intakes, nutritional inadequacies, vegetarianism, low body fat stores, and specific training behaviors may contribute to the abnormal menstrual patterns seen in this population. Recommendations for the detection and prevention of eating and training problems and consequent menstrual abnormalities are included.

Amenorrhea↗
PubMed1995

Effect of oral sensorimotor treatment on measures of growth, eating efficiency and aspiration in the dysphagic child with cerebral palsy.

Twenty-seven children (mean age 5.1 years) with cerebral palsy and moderate eating impairment were studied to determine frequency of aspiration and the effect of 10 and 20 weeks of oral sensorimotor therapy on eating efficiency and measures of growth (weight, skinfold thickness). The eating efficiency of the children did not change markedly in response to oral sensorimotor therapy. Children maintained their centile rank in weight-for-age and skinfold-for-age measurements. However, there was no catch-up growth. The findings suggest that eating efficiency is not a good estimator of treatment outcome, but rather a diagnostic indicator of the severity of eating impairment. Monitoring of these children's growth is essential in order to provide nutritional rehabilitation as soon as their eating skills can no longer keep up with growth demands.

Cerebral Palsy↗
PubMed1993

Radiology, surgery, and the pediatric chest.

Preoperative imaging of the tracheobronchial tree should focus on identifying the location, severity, and extent of tracheal narrowing, as well as possible causes of extrinsic compression. Plain film radiography and esophagography can be supplemented with CT or MR imaging for the evaluation of mediastinal masses or vascular abnormalities impinging on the airway. Surgical planning for the removal of intrathoracic tumors or cysts requires a detailed evaluation of the location and extent of the lesion, identification of encasement or compression of vital structures, and intraspinal extension to determine resectability and the need for neurosurgical consultation. Precise preoperative histologic diagnosis in most patients is not essential for surgical planning. Although the anatomic information provided by CT and MR imaging is comparable, MR offers the advantage of multiple imaging planes and allows the identification of intraspinal involvement of posterior mediastinal tumors or neuroenteric cysts without the use of intrathecal contrast agents. Conversely, MR imaging has little role in the assessment of pulmonary parenchymal abnormalities. These are best imaged with radiography and CT. Plain film radiography and contrast esophagography are often sufficient for the identification and delineation of postoperative complications in the chest. Complex air or fluid collections, however, may require further study with CT or ultrasonography for better characterization.

Child↗
PubMed1990

Eating problems and calorie intake levels in Swiss adolescent athletes.

The purpose of this study was to investigate the incidence of eating disorders (ED), calorie intake levels and body fat measures in Swiss female athletes. Thirty athletic and 34 non-athletic adolescent Swiss females were assessed for tendencies toward eating disorders and weight preoccupation using the Eating Disorders Inventory (EDI). Calorie intakes were calculated from 7-day intake records. Body compositions were determined using skin-fold measures. The athletes were divided into two groups: Those whose activities emphasize leanness (12 gymnasts, means age = 12.5 +/- 1.1 yrs), and those whose activities do not emphasize leanness (18 swimmers, mean age = 12.8 +/- 0.9 yrs). The non-athletic school-girls (mean age = 13.4 +/- 1.2 yrs) served as controls. ANOVA indicated that the gymnasts had lower body fat levels (p less than 0.01) and consumed fewer total calories (p less than 0.05) than swimmers or controls, but all groups consumed similar calories per kg/body weight. Chi square analysis indicated that similar numbers of swimmers (11%), gymnasts (1%) and controls (6%) were exceptionally preoccupied with weight (p greater than 0.05). However, more swimmers (38%) scored high on the body dissatisfaction subscale of the EDI than the gymnasts (1%) or control (9%) (p less than 0.01). In fact, more swimmers scored high on 3 subscales of the EDI compared to the other groups (p less than 0.05). It appears that disturbances in eating behaviors are not limited to sports that emphasize leanness.

Adolescent↗
PubMed1989

Relationship between nutrient intake, body mass index, menstrual function, and ballet injury.

The effects of inadequate nutrition, menstrual dysfunction, and low body weight on the injury rate of ballerinas were studied. Forty-nine female ballet dancers, mean age 18.7 years, completed food frequency and injury questionnaires. Subjects were placed in one of two groups: those with an intake less than 70% of the Recommended Dietary Allowances (RDA) for key nutrients and those with an intake greater than 70% of the RDA for key nutrients. Sixty-nine percent of the dancers had intakes less than 70% of the RDA and were randomly assigned to either a vitamin/mineral supplement or to placebo for 6 months. The remaining dancers with diets adequate (greater than 70% RDA) in key nutrients received no treatment. All groups were questioned monthly about the incidence, severity, and nature of ballet injuries. Information regarding menses and height and weight was obtained. There were no significant differences in the severity or type of injuries among the dancers in the supplement, placebo, or no treatment groups. Dancers with abnormal menses had more bone injuries (mean = 15.00) than normally menstruating dancers (mean = 4.97) (p less than .05). Dancers with a Body Mass Index less than 19.0 spent more days with a low-grade injury (mean = 24.05) than dancers with a greater BMI (mean = 11.63) (p less than .05). There appears to be a relationship between dance injuries and both BMI and menstrual function.

Adolescent↗