Longitudinal in vivo effects of growth hormone overexpression on bone in transgenic mice.

In this study we examined the effect of systemic overexpression of GH on bone in transgenic mice longitudinally in vivo over a period of 9 months. We observed substantially increased BMC in GH transgenic mice and a significant reduction in serum osteocalcin. GH effects on bone were strongly dependent on gender and developmental stage. INTRODUCTION: State-of-the-art bone marker and microimaging technology was applied in this longitudinal study to examine bone metabolism, BMC, bone density, and cortical bone structure over the life span of growth hormone (GH) transgenic (tg) mice. MATERIALS AND METHODS: Thirty-eight mice from four genetic groups (male, female, tg, and controls) were examined with DXA, and their femur and tibia were examined with peripheral QCT (pQCT). Osteocalcin (formation) and collagen cross-links (resorption) from serum and urine were also measured at postnatal weeks 3, 6, 9, 12, 18, 26, and 38. RESULTS: GH tg mice displayed a significant increase in body weight (up to 50%) and BMC (up to 90%), but serum osteocalcin was significantly reduced compared with controls. GH tg females (but not males) displayed increased trabecular density over controls up to week 12. In contrast, male (but not female) GH tg mice displayed a higher cortical cross-sectional area than controls. Cortical density was significantly lower in both male and female GH tg mice compared with control mice. CONCLUSIONS: The increase in BMC in GH tg mice is associated with reduced serum osteocalcin levels, indicating that bone turnover may be lower than in the control mice. On a structural level, bone responds to GH excess in a gender-specific manner, with alterations varying substantially between different developmental stages.     

External duodenal fistula following closure of duodenal perforation.

AIM: Retrospective analysis of experience with management of external duodenal fistula (EDF) without using total parenteral nutrition (TPN). METHOD: Medical records of 31 patients with EDF following closure of duodenal ulcer perforation, treated over a 7-year period (1994-2001), were studied. Twenty-one patients (68%) had evidence of sepsis at presentation or during the course of treatment. None could afford TPN for optimum time. All patients received hospital-based enteral nutrition through nasojejunal tube, besides supportive medical treatment and/or surgery. Peritonitis or failure to insert nasojejunal tube for enteric alimentation led to early surgery. RESULTS: Two patients died of septicemia and multi-organ failure within 48 hours of admission. Fourteen patients (48.3%) initially received conservative treatment (Group I); six of them later required surgery. Fifteen patients (51.7%) underwent early surgery due to peritonitis (n=9) or failure to establish enteral feeding (n=6) (Group II); wound infection, intra-abdominal abscess and septicemia were more common in these patients than those in Group I. Survival rate was higher in Group I than in Group II (86% versus 40%; p< 0.05). Septicemia and gastrectomy were the independent factors associated with high mortality. CONCLUSIONS: EDF can be satisfactorily managed without TPN. Successful placement of enteral feeding line, supportive treatment and delayed surgery can achieve survival in 85% of patients. Minimum intervention is recommended when early surgery is performed in peritonitis or to establish enteral feeding line.     

Brain abscess in Saudi Arabia

There are significant variations among countries in the incidence of brain abscess. We report here 26 cases of brain abscess treated at the Neurosurgery Department of King Faisal University and Dammam Central Hospital Saudi Arabia over a six year period (1982–1988). This is 2.3% of total admissions to the two neurosurgery departments serving a population of approximately 1.2 million in the same period.Young males were most often affected (M/F ratio 3.3:1; 31% were less than 15 years old, 46% aged between 15–39 years, and 23% older than 40 years). Streptococcus was found to be the most common microorganism (38.4%). Mixed infection was seen in 15.3%, and sterile abscesses were found in 11.5% of the patients after aerobic and anaerobic cultures of the pus. Chronic otitis media and paranasal sinusitis predisposed the patients to abscess formation in 57.6% of the cases. The temporo-parietal area was the commonest site. Epilepsy was a complication in 30.7% of our patients, and the mortality rate was 15.3%.     

Measured visual field extent varies with peripheral stimulus flicker rate in very young children.

PURPOSE: The purpose of this article is to describe measured visual field extent in very young children in response to variation in peripheral stimulus flicker rate. METHODS: Binocular visual field extent was measured using a black, double-arc perimeter and an LED static perimetry procedure in 120 11-month-old, 120 17-month-old, and 120 30-month-old children and 40 adults. Each subject was tested with one of four flicker rates: 1 Hz, 10 Hz, 20 Hz, or 40 Hz. An interpolated estimate of the eccentricity at which 50% of subjects detected the peripheral stimulus and the mean of the farthest eccentricity at which subjects detected the peripheral stimulus were calculated for each flicker rate for each age group. RESULTS: In 11-, 17-, and 30-month-old children, but not in adults, measured visual field extent (eccentricity at which the stimulus was detected) varied significantly with rate of stimulus flicker. The largest measured visual field extent was produced by a 10-Hz stimulus and the smallest was produced by 1-Hz and 40-Hz stimuli. Measured visual field extent in children was similar to that of adults for 10-Hz flicker, but smaller than that of adults for 1-Hz, 20-Hz, and 40-Hz flicker. CONCLUSIONS: These results underscore the importance of standardizing stimulus parameters when developing tests for clinical assessment of visual fields in children. Furthermore, for longitudinal assessment of young patients, use of a 10-Hz flicker rate, in combination with the other parameters used in the present study, would help to avoid difficulties in interpretation that could arise from an interaction between age-related and disease-related changes that might occur if other stimulus flicker rates were used.