Determination of total free and glucose-conjugated 3-phenoxybenzyl alcohol residues in foods by gas chromatography with electron capture detection.

A method was developed to determine the combined amounts of residual, free 3-phenoxybenzyl alcohol (permethrin alcohol) and its acetone-extractable glucosides in representative fruits and vegetables after application of pyrethyroid insecticides such as permethrin or cypermethrin. 3-Phenoxybenzyl glucoside was synthesized and used to spike food samples. Conditions were developed for extraction, enzymatic hydrolysis, derivatization with heptafluorobutyric anhydride, and cleanup prior to detection and quantitation by gas chromatography with electron capture detection. Limits of detection in various foods were < or = 0.01 ppm. In addition, 2 sets of field trial samples that were sprayed with permethrin and collected at intervals were also analyzed. In general, the amounts of total permethrin alcohol in foods were small.

Sonographic diagnosis of unsuspected gallbladder cancer: imaging findings in comparison with benign gallbladder conditions.

OBJECTIVE: Several sonographic findings were analyzed to determine their significance in distinguishing gallbladder cancer from benign conditions of the gallbladder. The analyzed findings were gallstone number and size; floating stones; displaced stones; wall thickening, irregularity, and echogenicity; mucosal plaque; intraluminal mass; gallbladder-replacing mass; invasive gallbladder mass; gallbladder mucosal discontinuity; hyperechoic gallbladder mucosa; and submucosal or transmural echolucency. MATERIALS AND METHODS: Sonograms of 20 patients with unsuspected, pathologically proven gallbaldder cancer and 65 patients with benign gallbladder conditions (predominantly acute or chronic cholecystitis) were retrospectively assessed by two observers who were unaware of experimental conditions. Gallstone number and size were assessed, and the presence of floating stone (neither settling nor wall-adherent), displaced stone (lifted from the gallbladder wall by mass or focal wall thickening), wall irregularity, mucosal plaque, intracystic mass, and gallbladder-replacing or invasive mass was evaluated. The echogenicity pattern of the gallbladder wall was characterized, and its thickness was measured and classified as normal/mildly thickened (< 7 mm) or moderately/severely thickened (> or = 7 mm). In addition, the gallbladder wall was evaluated for discontinuous mucosal echo, hyperechoic mucosa, submucosal or mural echolucency, and pericholecystic fluid collection. Sonographic findings were compared by the Mann-Whitney test for nonparametric variables and by Student's t test for continuous variables. RESULTS: Solitary gallstone, displaced stone, intraluminal mass, gallbladder-replacing or invasive mass, and discontinuity of the mucosal echo were all statistically significantly more common in patients with gallbladder cancer (.001 < p < .05). Mucosal plaque and wall irregularity were nonspecific findings. Gallbladder wall thickening by itself was nonspecific, although associated echolayering, transmural or submucosal edema, or a distinctly specular mucosal lining favored benign etiologies. CONCLUSION: Several sonographic findings were significantly more common in patients with gallbladder cancer compared with patients with benign gallbladder conditions. Assessment of these signs may be helpful in distinguishing gallbladder cancer from benign conditions of the gallbladder.

Preliminary studies on the bioavailability and disposition of bioincurred carrot residues of [14C] linuron and [14C]3,4-dichloroaniline in rats.

Carrots grown from seed in soils spiked with [14C = O]linuron or [14C-ring]3,4-dichloroaniline (DCA), were found to contain radioactivity equivalent to 0.73 ppm linuron or 0.60 ppm DCA. After exhaustive extraction with methanol these tubers still retained 35% and 67% of the original 14C-bioincurred residues, for linuron and DCA respectively. To examine the bioavailability of these residues, rats were dosed by gavage (water vehicle) with unextracted tubers and extracted tubers. For comparison purposes 14C-spiked carrot tubers and [14C] standards were also administered. Animals were maintained for 3 days in metabolism cages; urine, faeces, expired gases and several tissues were collected for radioassay. The following relative amounts of radioactivity (expressed as a percentage of the applied dose) were excreted (faeces/urine) for linuron or DCA dosing respectively: unextracted carrots, 28/31, 51/10; extracted carrots, 51/0, 73/3; spiked carrots, 11/43, 63/20; and linuron and DCA standards, 11/46, 26/81. The data demonstrated that approximately 31% and 10% of bioincurred 14C-residues (from linuron and DCA respectively) in unextracted carrot tubers were bioavailable to rats. 14C-Bound residues (extracted tubers) were much less bioavailable (0% and 3% respectively). The disposition of radioactivity in tissues, blood and expired gases was very low (less than or equal to 1.3% per sample) for any dose studied.

Determination of fluazifop-butyl and fluazifop acid in soybeans and soybean oil using liquid chromatography with oxidative amperometric detection.

A new method is described for the determination of the herbicide fluazifop-butyl, and its metabolite fluazifop acid, in soybeans and soybean oil as fluazifop acid. Liquid chromatography with amperometric detection (LC/AD) is used to determine fluazifop acid produced from the metabolism or base hydrolysis of fluazifop-butyl in soybeans and soybean oil. These foods were spiked with fluazifopbutyl at 0.05, 0.10, and 0.50 ppm and hydrolyzed with 0.2N NaOH in methanol. The hydrolysate (adjusted to pH less than or equal to 1) is extracted with dichloromethane and the extract is washed with 1.0% NaHCO3. The NaHCO3 is acidified to pH less than or equal to 1 and extracted with dichloromethane; the partitioning is repeated 2 more times. The dichloromethane is removed, mobile phase solvent is added, and aliquots are injected onto a PRP-1 liquid chromatographic column; fluazifop acid is separated from coextracted compounds and detected at an applied potential of + 1.25 V, using an amperometric electrochemical detector in the oxidation mode. Recoveries ranged from 69 +/- 6.5 to 101 +/- 18% and from 72 +/- 7.5 to 88 +/- 11% for soybeans and soybean oil, respectively. Accuracy of these recoveries was confirmed by use of 14C-radiolabeled fluazifop-butyl and by liquid scintillation spectrometry of the 14C-fluazifop acid released.

Body computed tomography findings in systemic lupus erythematosus.

Fifty-five computed tomography scans in 27 patients with systemic lupus erythematosus were reviewed. The most frequent indication for scanning was suspected intraabdominal sepsis, and the most frequent finding was mild lymphadenopathy. Renal abnormalities were: subcapsular hematoma, focal defects, overall enlargement, and diminution of size. Other findings included serositis, bowel wall thickening with pneumatosis intestinalis, pancreatic pseudocyst, and hepatic and splenic enlargement. Five abscesses were found that were indistinguishable from other fluid collections. Computed tomography was helpful in clinical evaluation and in some cases changed management.

Determination of naptalam and its metabolite in foods, as 1-naphthylamine, using liquid chromatography with oxidative electrochemical detection.

A new method is described for the determination of the herbicide naptalam and its metabolite 1-naphthylamine in several foods. The method is sensitive, selective, and extremely rapid compared with previously reported methods. Liquid chromatography with electrochemical detection (LC/ECD) is used to determine 1-naphthylamine produced from the metabolism or base hydrolysis of naptalam in asparagus, peaches, and cranberries. These foods were spiked with naptalam at 0.05 and 0.11 ppm and hydrolyzed with 30% NaOH with concomitant distillation of 1-naphthylamine. Aliquots of the distillate were injected onto a reverse-phase PRP-1 LC column for separation of 1-naphthylamine from coextractives near the solvent front and detection at an applied potential of +0.83 V using an amperometric electrochemical detector in the oxidation mode. Recoveries ranged from 89% +/- 2% to 97% +/- 8% for all foods at both spiking levels. Accuracy of these recoveries was confirmed by use of 14C-radiolabeled naptalam and radioassay by liquid scintillation spectrometry of the 14C-1-naphthylamine released.

Embolization of blunt trauma in the pediatric patient.

The use of embolization for control of hemorrhage following blunt trauma is well accepted in the adult population. This paper describes 2 cases in which embolization techniques were used successfully to control hemorrhage following blunt trauma in pediatric patients.

Magnetic resonance imaging of lesions of synovial origin.

Three patients with histologically differing lesions of synovial origin and two with synovial cysts, one of which was a dissecting popliteal cyst, were examined by magnetic resonance imaging (MR) and computerized tomography (CT). The three histologically proven synovial lesions were synovial sarcoma, diffuse giant cell tumor of tendon sheath, and synovial chondromatosis. In two of the five patients MR provided better anatomic and morphologic appreciation than CT, while in the others they were of equal value. CT demonstrated calcification in two of the lesions while on MR calcification could be identified in only one patient where it outlined the mass. MR did not demonstrate calcification in the substance of the diffuse giant cell tumor of tendon sheath. Coronal, transverse, and sagittal images of magnetic resonance graphically demonstrated the extent of the soft tissue masses and their relationship to bone, vessels, and soft tissue structures. Synovial sarcoma had a shorter T1 than diffuse giant cell tumor of tendon sheath (these two lesions being of comparable size) and also had a uniformly longer T2. The dissecting popliteal cyst showed the most intense signals on the T1 weighted images, while the uncomplicated synovial cyst showed a long T1. On the T2 weighted images, each type of cyst showed a long T2. The variance and overlap of intensity of MR signals suggest limited specificity in predicting the histologic nature of the synovial lesion.

CT characteristics of aortic atherosclerotic aneurysm versus aortic dissection.

In an attempt to better define criteria for the diagnosis of atherosclerotic aneurysm (AA) and aortic dissection (AD) using CT the scans of 60 documented aortic lesions were reviewed. Hyperdensity of the aortic wall at multiple levels was found to be specific for AD. Central displacement of atheromatous calcification and deformity of the residual aortic lumen were more common in AD than in AA. Peripheral location of aortic wall calcification and a round aortic lumen in cross section were more common in AA than in AD. Central calcification in AA appeared to be associated with a serious short-term prognosis in several cases. A thickened aortic wall of low density was more common in AA than in acute AD, but this relationship was not significant when acute and chronic ADs were considered as a single group. Wall thickness correlated with cross-sectional size of the aortic lesion in AA but not in AD. The mean maximum wall thickness exceeded 1 cm for both AA and AD and was not significantly different between the two; contrary statements have been made in the angiographic literature.

CT findings in leukemia.

Review of 84 computed tomographic (CT) scans in leukemic patients demonstrated a wide spectrum of abnormalities. Findings caused by leukemia were lymphadenopathy, visceral enlargement, focal defects, and tissue infiltration. Hemorrhage was by far the most common complication and could usually be characterized on the noncontrast CT scan. The distinction between old hematomas, foci of infection, and leukemic infiltration could not be made with certainty without CT-guided aspiration. Unusual instances of sepsis, such as microabscesses of the liver and typhlitis, were seen.

Hyperdensity of recent hemorrhage at body computed tomography: incidence and morphologic variation.

Body computed tomographic (CT) scans were reviewed in 73 patients with hematomas of recent onset. The incidence, extent, and morphologic variation of regions of hyperdensity on precontrast scans were assessed. Hyperdensity was also sought in the scans of 80 control subjects with a mass due to neoplasm or abscess demonstrated at CT. Of the 73 hematomas 55 (75%) exhibited regions of localized or diffuse hyperdensity. Only one of the 80 (1.25%) control lesions showed relative hyperdensity that could not be explained by obvious calcification, bone fragments, or diminished density of the organ of origin. Predominant hyperdensity throughout the lesion was present in 35 (48%) of the hematomas and in 16 (22%) of these was homogenous in texture. Other patterns of hyperdensity included linear shadows, hyperdense filling defects surrounded by fluid, dependent position of hyperdense fragments, and fluid fluid levels with dependent hyperdensity. Hyperdensity at CT was due to the high hemoglobin content of retracted clot or sedimented blood. The various patterns seen can be related to sequential changes occurring in blood following hemorrhage. Relative hyperdensity and its variations seen on precontrast scans are useful diagnostic signs of recent hemorrhage.

CT in aortic trauma.

A diagnosis of aortic transection was made at computed tomography (CT) in four of 10 patients with acute multiple trauma suspected of having thoracic aortic injuries. There were no false-negative or false-positive examinations. The CT findings of an injured aorta were (1) false aneurysm, (2) linear lucency within the opacified aortic lumen caused by the torn edge of the aortic wall, (3) marginal irregularity of the opacified aortic lumen, (4) periaortic or intramural aortic hematoma, and (5) dissection. The extent of associated mediastinal hemorrhage and the amount of blood in the pleural space were not useful as indicators of aortic injury. Similarly, shift of the trachea and esophagus or absence thereof was found in patients with or without aortic tear.

Carotid atherosclerosis: high-resolution real-time sonography correlated with angiography.

The merits of high-resolution real-time sonography in detection of plaque and estimation of stenoses were compared with angiography in 97 carotid bifurcations from 50 consecutive patients. For flow-reducing lesions, that is, stenosis greater than or equal to 50% or complete occlusion, sonographic accuracy was 86% and the mean difference in percentage narrowing was 17% (SD, 21.6%). For detection of normal or non-flow-reducing lesions, that is, less than 50% stenosis, sonographic accuracy was 89% and the mean difference in percentage narrowing was 8% (SD, 10.2%). Errors occurred mainly in severely diseased vessels and were often related to calcification in lesions and/or plaque of low echogenicity. Accuracy was lowest in predicting complete vessel occlusion (36%). Greatest accuracy was found in assessment of minimal disease. The technique is a useful supplement to the battery of noninvasive tests used to screen patients at risk for stroke and in defining those requiring angiography before surgery.

A method for the determination of octa- and nonachloro-2-phenoxyphenols in chicken tissue.

A gas-liquid chromatographic method was developed capable of determining octa- and nonachloro-2-phenoxyphenols in chicken liver or muscle at 0.25 ppb and fat at 2.5 ppb. The method involves extraction with acidified acetone:hexane, cleanup with concentrated H2SO4 and Florisil column chromatography, methylation with diazomethane, and quantitation by capillary column gas-liquid chromatography with electron capture detection. Fortification of liver and muscle at 0.25 or 0.5 ppb and fat at 2.5 or 5.0 ppb and subsequent analysis yielded recoveries averaging 91% for octa- and 97% for nonachlorophenoxyphenol.

Comparison of computed tomography with high-resolution real-time ultrasound in the localization of the impalpable undescended testis.

Localization of an undescended testis was attempted in 23 instances in 20 patients using both computed tomography (CT) and high-resolution real-time ultrasonography. The testis was identified and correctly localized 16 times by CT and 15 times by ultrasound. There was one false-negative diagnosis by CT and two by ultrasound. False-positive diagnoses were not made with either modality in the six cases in which the testis was not found during exploratory surgery. CT showed 94% sensitivity, 100% specificity, and 96% accuracy; ultrasound resulted in 88% sensitivity, 100% specificity, and 91% accuracy. The authors recommend high-resolution real-time ultrasound as the modality of choice for this procedure because it is simple, accurate, and avoids the use of ionizing radiation. CT may be used when ultrasound findings are negative or equivocal. Angiography should rarely be required.

Comparison of double indicator thermodilution measurements of extravascular lung water (EVLW) with radiographic estimation of lung water in trauma patients.

The availability for clinical use of a simple reliable method of determining extravascular lung water (EVLW) provided us with the opportunity to evaluate the accuracy of the plain chest roentgenogram in estimating EVLW in patients with severe trauma. Twelve patients who sustained blunt trauma in motor vehicular accidents were studied. Interval measurements of EVLW were made utilizing the thermal-green dye, double-indicator dilution technique and the results compared in a blind manner to estimation of lung water content on standard chest roentgenograms. The results indicate a significant correlation was present when EVLW was compared to roentgenographic density grade. Considerable overlap existed in quantitative EVLW content between radiographic grades except when extensive consolidation was present on the chest radiograph which was associated with EVLW measurements of greater than 10 ml/kg. The random comparison of a change in measured EVLW with a change in radiographic density indicated that there were opposite changes in 23% of the comparisons. However, in selected patients with progressive improvement (decrease) in EVLW or gradual deterioration (increase) in EVLW over time there was good correlation between improvement or deterioration in the chest radiographic appearance with the decrease or increase in EVLW. There is some ability to ascertain in trauma patients interstitial fluid accumulation from chest radiographs, but attempts at quantitation would be fraught with considerable error.

Utility of CT-guided abdominal aspiration procedures.

Over 200 consecutive diagnostic needle aspiration procedures of the abdomen were performed under computed tomographic (CT) guidance. Biopsies were done of the liver in 88 patients, the pancreas in 28, the kidney in 20, and the retroperitoneum in 32; 30 underwent an aspiration procedure for characterization of an intraabdominal fluid collection. Accuracy of diagnosis was very high for hepatic (99%) and renal (100%) biopsies and in characterization of fluid collections (100%). Accuracy for retroperitoneal biopsy was 87.5% and for pancreatic biopsy 82%. Overall accuracy for all sites was 95%. There were one false-negative diagnosis for the liver and five false-negative diagnoses for the pancreas. Insufficient material was obtained for diagnosis in four instances of retroperitoneal biopsy. There were no false positives. The technique is facilitated by rapid CT scan time, large aperture gantry, and rapid CT image reconstruction. Twenty gauge needles were used more frequently than 22 gauge needles because of their greater rigidity and ease of control. CT-guided diagnostic aspiration procedures are particularly useful for diagnosis of small, deep-seated lesions and in evaluation of lesions found in severely ill patients. An experienced cytologist is essential to the success of the technique.