With recent technologic developments, the role of computed tomography (CT) in the diagnosis of bowel obstruction has expanded. CT is recommended when clinical and initial radiographic findings remain indeterminate or strangulation is suspected. This modality clearly demonstrates pathologic processes involving the bowel wall as well as the mesentery, mesenteric vessels, and peritoneal cavity. CT should be performed with intravenous injection of contrast material, and use of thin sections is recommended to evaluate a particular region of interest. CT is reported to have a sensitivity of 78%-100% for the detection of complete or high-grade small bowel obstruction but may not allow accurate diagnosis in cases involving incomplete obstruction. In such cases, the use of adjunct enteroclysis is indicated. Furthermore, multiplanar reformatted imaging may help identify the site, level, and cause of obstruction when axial CT findings are indeterminate. CT can also demonstrate findings that indicate the presence of closed-loop obstruction or strangulation, both of which necessitate emergency exploratory laparotomy. Unfortunately, these pathologic conditions may be missed, and patients with suspected severe obstruction or bowel ischemia in whom CT and clinical findings are widely disparate must also undergo laparotomy. In general, however, CT allows appropriate and timely management of these emergency cases.

Madin-Darby canine kidney cells behave like the renal medulla and accumulate small organic solutes (osmolytes) in a hypertonic environment. The accumulation of osmolytes is primarily dependent on changes in gene expression of enzymes that synthesize osmolytes (sorbitol) or transporters that uptake them (myo-inositol, betaine, and taurine). The mechanism by which hypertonicity increases the transcription of these genes, however, remains unclear. Recently, it has been reported that yeast mitogen-activated protein (MAP) kinase and its activator, MAP kinase-kinase, are involved in osmosensing signal transduction and that mutants in these kinases fail to accumulate glycerol, a yeast osmolyte. No information is available in mammals regarding the role of MAP kinase in the cellular response to hypertonicity. We have examined whether MAP kinase and MAP kinase-kinase are regulated by extracellular osmolarity in Madin-Darby canine kidney cells. Both kinases were activated by hypertonic stress in a time-and osmolarity-dependent manner and reached their maximal activity within 10 min. Additionally, it was suggested that MAP kinase was activated in a protein kinase C-dependent manner. These results indicate that MAP kinase and MAP kinase-kinase(s) are regulated by extracellular osmolarity. (J. Clin. Invest. 1994. 93:2387-2392

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III.

Expanding hematoma of the abdominal wall is a rare example of acute abdominal disease. We report two cases of lateral abdominal wall hematoma caused by the rupture of a deep circumflex iliac artery, which is a rare cause of an abdominal wall hematoma. Both patients experienced severe abdominal pain after sneezing or coughing. In both cases, computed tomography (CT) findings suggested that active bleeding was continuing. Emergent angiography was therefore performed, and the hematoma was embolized using Spongel or Microcoils. Ultrasound examinations were repeatedly used to monitor the size of the hematoma. The size of the hematoma and patient's pain gradually decreased after embolization. Ultrasound and CT examinations provided useful information for the differential diagnosis of this disease. We conclude that emergent angiography should be performed to control bleeding and avoid any unnecessary surgical procedures in patients with hematoma of the abdominal wall.

Excellent E-selectivity was observed in the HornerWadsworth-Emmons (HWE) reactions of ethyl 2-fluoro-2-diethylphosphonoacetate 1 with alkyl aryl ketones 2a-f using Sn(OSO 2 CF 3 ) 2 and N-ethylpiperidine. Mg(II)-promoted HWE reactions of 1 with aldehydes 2h,i afforded α-fluoro-α,β-unsaturated esters 3h,i in a Z-selective manner depending on the reaction temperatures.α-Fluoro-α,β-unsaturated esters play an important role in the preparation of biologically active fluorine compounds, and various synthetic methods have been developed. 1 Most of the construction methods for the α-fluoro-α,β-unsaturated esters have shown Zselectivity. 2 However, Horner-Wadsworth-Emmons (HWE) reactions of aldehydes with ethyl 2-fluoro-2-diethylphosphonoacetate 1 can preferentially furnish E-α-fluoro-α,β-unsaturated esters. 3-5 There have been a few reports on the HWE reactions with ketones in the presence of some base but the stereoselectivity is not clear or poor. 6 Recently, we have developed a new reaction mode of the HWE reaction using Sn(OSO 2 CF 3 ) 2 and N-ethylpiperidine to obtain excellent Z-selectivity in the reactions of methyl bis(trifluoroethyl)phosphonoacetate with l alkyl aryl ketones. 7 We now wish to report highly E-selective HWE reactions of ethyl 2-fluoro-2-diethylphosphonoacetate 1 with alkyl aryl ketones 2a-f using Sn(OSO 2 CF 3 ) 2 and N-ethylpiperidine as shown in Scheme 1. A tendency to afford Z-alkenes in the Mg(II)-mediated HWE reactions of fluorophosphonate 1 with aldehydes is also described. All reaction conditions and results are summarized in Tables 1-3. Scheme 1The HWE reactions of alkyl aryl ketones 2a-f with 1 in the presence of sodium hydride in THF 0 °C gave the corresponding α-fluoro-α,β-unsaturated esters 3a-f with modest E-selectivity (Table 1, entries 1-6). On the other hand, treatment of 2a-f with 1 in the presence of Sn(OSO 2 CF 3 ) 2 and N-ethylpiperidine in CH 2 Cl 2 at 0 °C afforded alkenes 3a-f in a highly E-selective manner, respectively (Table 2, Downloaded by: University of Pittsburgh. Copyrighted material.

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Aiming application of the high hole drift mobility in organopolysilanes, the organopolysilane-based organic layered photoreceptors for electrophotography have been developed with phthalocyanine pigments as a photo-generating material. The photoreceptor combined with titanylphthalocyanine exhibited the high sensitivity of 1.8 cm2 (μJ)−1 at 780 nm and fairly good stability, suggesting the possibility for practical use of organopolysilanes.