Acute appendicitis: effect of increased use of CT on selecting patients earlier

PURPOSE: To explore the possibility of a relationship between increased use of computed tomography (CT) for diagnosis of appendicitis and increased occurrence of minimal or subtle CT and surgical findings. MATERIALS AND METHODS: Two groups, each with 50 consecutive patients who underwent CT before appendectomy in 1997 and 2000, were compared. CT scans and surgery-pathology reports were evaluated on a six-grade scale from normal to abscess or inflammatory mass. The demographics, surgical techniques, hospital stay, and grade distribution for the two groups were compared, and the CT results were correlated with surgical findings. RESULTS: In 1997, CT was performed in 33% (50 of 152) of patients undergoing appendectomy, as compared with 59% (50 of 85) 3 years later (P <.001). There was excellent correlation between surgical-pathologic and CT grades (weighted kappa, 0.75; P <.001; Spearman rank correlation, 0.83). There was no significant difference in demographics, rate of surgery, or surgical techniques used, but there was a significant decrease in the median surgical-pathologic grades, from 3.0 to 2.5 (P =.05) for all patients and from 3.5 to 2.6 (P =.003) for patients who underwent CT. Similarly, the median CT grade decreased from 4 to 3 (P <.001). Seven patients had subtle CT findings in 1997 compared with 16 in 2000 (P =.004), and there was a significant decrease in mean hospital stay, from 2.8 days +/- 4 (SD) to 1.5 days +/- 2 (P =.008). CONCLUSION: With increased CT use, there were less severe imaging findings, including absence of periappendiceal stranding, and a significant decrease in surgical-pathologic severity of appendiceal disease and hospital stay.     

Detection of pulmonary embolism: comparison of paddlewheel and coronal CT reformations--initial experience

In five patients with acute multilobar pulmonary embolism (PE) who were imaged with multi-detector row CT angiography, maximum intensity projection images were reformatted from axial images into rotated paddlewheel and coronal planes with three slab thicknesses and were reviewed for evidence of PE on a per-vessel basis with consensus of two readers. Paddlewheel reformations had a significantly higher percentage of overall detection of PE than did coronal reformations obtained with equivalent slab thickness (P <.0001). Paddlewheel reformations with 5.0-mm slab thickness had no significantly different percentage of overall detection of PE compared with that of axial images obtained with 2.5-mm collimation.     

Biotransformation of 3,5-dibromo-4-hydroxybenzonitrile under denitrifying,Fe(III)-reducing,sulfidogenic, and methanogenic conditions

Bromoxynil (3,5-dibromo-4-hydroxybenzonitrile) is a halogenated aromatic nitrile herbicide used on a variety of crops for the postemergence control of annual broad-leaved weeds. The anaerobic biodegradability of bromoxynil and its aerobic transformation product, 3,5-dibromo-4-hydroxybenzoate, were examined in enrichment cultures established with anaerobic sediment under denitrifying, Fe(III)-reducing, sulfidogenic, and methanogenic conditions. Bromoxynil (100 microM) was depleted in 20 to 30 d in the methanogenic, sulfidogenic, and Fe(IIi)-reducing enrichments but was stable under denitrifying conditions. The 3,5-dibromo-4-hydroxybenzoate (100 microM) was depleted within 20 to 35 d under all four anaerobic conditions. Both compounds were stable in sterile controls. Bromoxynil and 3,5-dibromo-4-hydroxybenzoate were readily utilized upon respiking of the cultures. During utilization of bromoxynil, stoichiometric release of bromide was observed with transient accumulation of metabolites identified as bromocyanophenol, cyanophenol, and phenol. Bromoxynil heptanoate and octanoate were rapidly hydrolyzed to bromoxynil, which was further degraded. These results indicate that bromoxynil and 3,5-dibromo-4-hydroxybenzoate are degraded under different anaerobic conditions. Anaerobic degradation of bromoxynil proceeds via reductive debromination to 4-cyanophenol, which is further transformed to phenol and can ultimately be degraded to carbon dioxide.     

Neuroblastoma,apoptosis, and growth factors

Neuroblastoma is the most common extracranial tumor of childhood. This tumor is associated with alterations in apoptosis and is affected by various growth factors and cytokines. In this short review we will discuss recent findings in our laboratory where we have been studying a cell culture model of neuroblastoma.     

Evidence-based medicine of the acute respiratory distress syndrome

Different therapeutic approaches have recently been developed for treatment of acute respiratory distress syndrome (ARDS) with the aim of improving the outcome. The clinical significance and success of these therapies is variable with respect to evidence based medicine. Lung protective ventilation is accepted as a proven therapy and the use of positive end-expiratory pressure as well as spontaneous breathing during controlled ventilation are common therapies. High frequency ventilation, partial liquid ventilation and pulmonary surfactant application are still in the experimental stage. The prone position is recommended for severe cases of ARDS and the application of inhaled nitric oxide and of extracorporeal membrane oxygenation is established in specialized centers for patients with imminent hypoxia. But for the routine use of these three therapies a clear improvement in outcome could not demonstrated. Recommended drug therapy is limited to the administration of stress doses of corticosteroids and a special anti-inflammatory enteral diet.     

Preoperative predictors of malignancy in pancreatic intraductal papillary mucinous neoplasms

HYPOTHESIS: Malignant intraductal papillary mucinous neoplasms (IPMNs) can be predicted before surgery. DESIGN: Retrospective review of a prospectively collected database. SETTING: Academic, urban, tertiary care hospital. PATIENTS: Sixty-four consecutive patients with a pathological diagnosis of IPMN. INTERVENTIONS: All 64 patients underwent surgical intervention for IPMN between December 8, 1988, and October 16, 2002. MAIN OUTCOME MEASURES: Reliable predictors of malignancy. RESULTS: The 64 patients underwent 69 operations: 39 pancreaticoduodenectomies, 18 distal pancreatectomies, 7 total pancreatectomies, 4 neck and/or body pancreatectomies, and 1 cystgastrostomy with pancreatic biopsy. Twenty-three of 69 specimens were malignant-12 in situ (high-grade dysplasia) and 11 invasive. In a univariate analysis of 12 clinical signs or symptoms recorded, diabetes mellitus and jaundice showed a significant association with malignancy of IPMN. Of 24 serum chemistry studies, hematologic studies, and tumor marker analyses (in serum, bile, and pancreatic fluid), elevation of serum alkaline phosphatase and glucose levels showed correlation with malignancy. Computed tomography, ultrasound, and endoscopic retrograde cholangiopancreatography findings did not distinguish between benign and malignant tumors. Atypia on preoperative cytologic analysis was specific for malignancy (93%) but lacked the same degree of sensitivity (40% in situ, 91% invasive, and 67% overall). CONCLUSIONS: Malignancy of IPMNs is suggested by new-onset diabetes mellitus, jaundice, and elevations in serum glucose or alkaline phosphatase levels. Atypia on preoperative cytologic testing is the finding most predictive of malignancy. The absence of these features does not predict benign disease. These findings may help guide patient and physician decision making.