MR imaging of hypervascular liver tumors: timing optimization during the arterial phase

To analyze the optimal timing strategy for the detection of hypervascular liver tumors during the arterial phase of magnetic resonance (MR) imaging, a test examination after injection of 2 mL of gadopentetate dimeglumine was performed in 47 patients. The time course of the tumor-to-liver contrast-to-noise ratio (CNR) for all studies together was determined relative to the start of injection, the time of peak aortic enhancement, and the time of peak enhancement in the tumor. All studies were grouped together and the highest CNR was transiently observed at the time of peak tumor enhancement. This CNR was significantly higher than those observed at fixed delays after peak aortic enhancement. However, the CNRs at peak tumor enhancement+/-1.5 seconds did not differ significantly from those obtained after peak aortic enhancement. Finally, the CNRs obtained at fixed delays after the start of injection remained significantly lower. In hypervascular liver tumors, a higher CNR can be obtained during the arterial phase when the MR imaging delay is determined relative to the time of peak enhancement in the tumor or the aorta rather than being fixed after the start of contrast material injection. Timing based on the enhancement profile in the tumor rather than in the aorta should be performed only if rapid MR imaging is available with a time resolution of about 1.5 seconds to image the whole liver.     

Cardiopulmonary resuscitation: effect of CPAP on gas exchange during chest compressions

BACKGROUND: Conventional cardiopulmonary resuscitation (CPR) includes 80-100/min precordial compressions with intermittent positive pressure ventilation (IPPV) after every fifth compression. To prevent gastric insufflation, chest compressions are held during IPPV if the patient is not intubated. Elimination of IPPV would simplify CPR and might offer physiologic advantages, but compression-induced ventilation without IPPV has been shown to result in hypercapnia. The authors hypothesized that application of continuous positive airway pressure (CPAP) might increase CO2 elimination during chest compressions. METHODS: After appropriate instrumentation and measurement of baseline data, ventricular fibrillation was induced in 18 pigs. Conventional CPR was performed as a control (CPR(C)) for 5 min. Pauses were then discontinued, and animals were assigned randomly to receive alternate trials of uninterrupted chest compressions at a rate of 80/min without IPPV, either at atmospheric airway pressure (CPR(ATM)) or with CPAP (CPR(CPAP)). CPAP was adjusted to produce a minute ventilation of 75% of the animal's baseline ventilation. Data were summarized as mean +/- SD and compared with Student t test for paired observations. RESULTS: During CPR without IPPV, CPAP decreased PaCO2 (55+/-28 vs. 100+/-16 mmHg) and increased SaO2 (0.86+/-0.19 vs. 0.50+/-0.18%; P < 0.001). CPAP also increased arteriovenous oxygen content difference (10.7+/-3.1 vs. 5.5+/-2.3 ml/dl blood) and CO2 elimination (120+/-20 vs. 12+/-20 ml/min; P < 0.01). Differences between CPR(CPAP) and CPR(ATM) in aortic blood pressure, cardiac output, and stroke volume were not significant. CONCLUSIONS: Mechanical ventilation may not be necessary during CPR as long as CPAP is applied. Discontinuation of IPPV will simplify CPR and may offer physiologic advantage.     

Perineal one-stage pull-through for Hirschsprung's disease

PURPOSE: The aim of this study was to present the strategy of a one-stage repair of Hirschsprung's Disease (HD) performed via a transanal approach. METHODS: Ten consecutive neonates and one toddler underwent transanal repair for biopsy-proven HD. A rectosigmoid transition zone was suggested by contrast enema in all patients. The mean age at operation for the neonates was 4 days. A mucosal dissection was begun 0.5 cm proximal to the dentate line. Once the correct plane was established, up to 15 cm of bowel can be resected without ligating vessels or performing a transabdominal dissection. The proximal extent of dissection was delineated by the presence of ganglion cells seen on frozen section analysis. RESULTS: The mean operating time was 105 minutes. There were no intraoperative or postoperative complications. All children had the presence of ganglion cells confirmed postoperatively on permanent sections. The mean hospital stay was 2 days. All children averaged three to six bowel movements per day without oral or enema therapy. CONCLUSIONS: The perineal one-stage operative pull-through (POOP) procedure for Hirschsprung's disease is a quick and easy adaptation of a well-described technique of transanal mucosectomy. Long-term follow-up will be required to determine whether bowel function is better that that seen after traditional staged repairs.     

Development and evaluation of an abridged, 5-item version of the International Index of Erectile Function (IIEF-5) as a diagnostic tool for erectile dysfunction

An abridged five-item version of the 15-item International Index of Erectile Function (IIEF) was developed (IIEF-5) to diagnose the presence and severity of erectile dysfunction (ED). The five items selected were based on ability to identify the presence or absence of ED and on adherence to the National Institute of Health's definition of ED. These items focused on erectile function and intercourse satisfaction. For 1152 men (1036 with ED, 116 controls) analyzed, a receiver operating characteristic curve indicated that the IIEF-5 is an excellent diagnostic test. Based on equal misclassification rates of ED and no ED, a cutoff score of 21 (range of scores, 5-25) discriminated best (sensitivity=0.98, specificity=0. 88). ED was classified into five severity levels, ranging from none (22-25) through severe (5-7). Substantial agreement existed between the predicted and 'true' ED classes (weighted kappa=0.82). These data suggest that the IIEF-5 possesses favorable properties for detecting the presence and severity of ED.     

Mid-third forearm fractures in children: an unorthodox treatment

Twenty children with fractures of both bones in the middle third of the forearm were immobilized in extension after closed reduction. Unlike distal-third fractures, these fractures are prone to develop rotary and angular deformities that may lead to permanent functional impairment and visible deformity. Mid-third forearm fractures with the radius fracture proximal to the ulnar fracture are even more troublesome. Nineteen patients had no clinical deformity at cast removal, and by 1 year, there was no difference in forearm rotation. Extension casting can be used initially for proximal fractures or to salvage forearms that lost reduction in flexed elbow casts. Extension cast application is easy while the reduction is maintained, whereas the problems are often encountered while applying a flexed elbow cast. This unorthodox treatment is safe and effective and may alleviate the need for surgical intervention.     

Why does postpsychotic IQ decline in childhood-onset schizophrenia?

OBJECTIVE: The authors' goal was to examine whether the postpsychotic decline in full scale IQ during adolescence for patients with childhood-onset schizophrenia is due to a dementing process or simply failure to acquire new information and skills. METHOD: Linear regression was used to determine the rate of change for scaled and raw scores on subtests of 31 patients with childhood-onset schizophrenia. The resulting slopes were examined and related to changes in the patients' brains determined by magnetic resonance imaging. RESULTS: Three postpsychotic subtest scaled scores declined significantly: picture arrangement, information, and block design. In contrast, there was no decline in the non-age-corrected (raw) scores for any subtest. A significant correlation was found between decrease in hippocampal volume and a smaller increase in raw score on the information subtest. CONCLUSIONS: The decline during adolescence in the full-scale IQ of patients with childhood-onset schizophrenia does not reflect dementia but, rather, an inability to acquire new information and abilities.     

MRI volumes of the hippocampus and amygdala in adults with Down's syndrome with and without dementia

OBJECTIVE: This study sought to determine whether volumes of the hippocampus and amygdala are disproportionately smaller in subjects with Down's syndrome than in normal comparison subjects and whether volume reduction is greater in Down's syndrome subjects with dementia. METHOD: The subjects were 25 adults with Down's syndrome (eight with dementia) and 25 cognitively normal adults who were individually matched on age, sex, and race. Magnetic resonance imaging measures included volumes of the hippocampus, amygdala, and total brain. Nineteen of the Down's syndrome subjects had follow-up scans (interscan interval = 9-41 months). RESULTS: Nondemented Down's syndrome subjects had significantly smaller volumes of the hippocampus, but not the amygdala, than their comparison subjects, even when total brain volume was controlled for. Volumes of both the hippocampus and the amygdala were smaller in the demented Down's syndrome subjects than in their comparison subjects, even when total brain volume was controlled for. Age was not correlated with volume of the hippocampus or amygdala among the nondemented Down's syndrome subjects and the comparison subjects; age was correlated with volume of the amygdala, but not the hippocampus, among the Down's syndrome subjects with dementia. Changes in volume over time were not statistically significant for either the demented or the nondemented subjects. CONCLUSIONS: Hippocampal volume, while disproportionately small for brain size in individuals with Down's syndrome, remains fairly constant through the fifth decade of life in those without dementia. All subjects over age 50 who had Down's syndrome demonstrated volume reduction in the hippocampus as well as clinical signs of dementia. Dementia was also associated with volume reductions in the amygdala that exceeded reductions in total brain volume.     

Symptomatic relapse in bulimia nervosa following acute tryptophan depletion

BACKGROUND: Preclinical and clinical studies suggest that lowered brain serotonin neurotransmission may contribute to the pathophysiology of bulimia nervosa (BN). The aim of our study was to test this hypothesis by examining the psychological effects of a dietary-induced impairment in serotonin activity in subjects known to be at risk for manifestation of the clinical syndrome of BN. METHODS: An 85.8 g amino acid mixture lacking the serotonin precursor tryptophan and a balanced mixture were administered to 10 clinically recovered, medication-free female subjects with a history of BN in a double-blind, crossover design. Twelve healthy female subjects with no history of psychiatric disorder were studied as a comparison group. Observer and self-rated measures of mood and eating disorder cognitions were made for the 7 hours following administration of each amino acid mixture. RESULTS: Compared with healthy controls, subjects with a history of BN had significant lowering of mood, increases in ratings of body image concern, and subjective loss of control of eating following the tryptophan-free mixture. CONCLUSIONS: Our results suggest that diminished serotonin activity may trigger some of the cognitive and mood disturbances associated with BN. Our findings support suggestions that chronic depletion of plasma tryptophan may be one of the mechanisms whereby persistent dieting can lead to the development of eating disorders in vulnerable individuals.