Spontaneous rupture of a left gastroepiploic artery aneurysm in a patient with autosomal-dominant polycystic kidney disease.

Autosomal-dominant polycystic kidney disease (ADPKD) has been known to be associated with a variety of vascular diseases. We present a hemodialysis patient with ADPKD who died of a massive intraperitoneal hemorrhage caused by the spontaneous rupture of a left gastroepiploic artery aneurysm. A 64-year-old male was admitted to our hospital with acute upper abdominal pain and hemorrhagic shock. An abdominal angiography showed three aneurysms and the source of hemorrhage was assumed to be the left gastroepiploic artery aneurysm. The patient died of severe metabolic acidosis and disseminated intravascular coagulation (DIC) on the second hospital day. At autopsy, there was massive bleeding into the abdominal cavity, and pathological examination of the left gastroepiploic artery aneurysm revealed a dissecting aneurysm. This is the first case describing a rupture of a gastroepiploic aneurysm in a patient with ADPKD.

Case report: right subclavian artery pseudoaneurysm due to perforation of esophageal cancer.

A 51-year-old man presented with massive hematemesis. Perforation of upper esophageal cancer, which had already occurred at least six days earlier, progressed to upper mediastinitis. The mediastinitis contiguous to the right subclavian artery was considered to have caused a pseudoaneurysm. Rupture of the pseudoaneurysm into the esophagus resulted in massive hematemesis. Both enhanced computed tomography and angiography were diagnostic for the pseudoaneurysm. Transluminal endovascular stent-grafts placement was successful in preventing subsequent hemorrhage.

Gluteal muscle necrosis following transcatheter angiographic embolisation for retroperitoneal haemorrhage associated with pelvic fracture.

Transcatheter angiographic emobilisation has been used as an effective control of haemorrhage associated with pelvic fracture. Although few complications of this procedure have been reported, gluteal muscle necrosis occurs occasionally. We assessed the type of pelvic fracture, concomitant injury, embolic site, embolic materials, and outcome in cases of gluteal muscle necrosis associated with angiographic embolisation for pelvic fracture-related haemorrhage, and investigated the factors associated with the development of gluteal muscle necrosis, one of the fatal complications of transcatheter angiographic embolisation. Five out of the 151 patients (incidence, 3.3%) who underwent transcatheter angiographic embolisation for haemorrhagic shock due to pelvic fracture developed gluteal muscle necrosis after embolisation. The five cases had injury severity scores ranging from 26 to 59 (mean 46.4). Three patients died (mortality, 60%) of subsequent sepsis and disseminated intravascular coagulation. These cases showed that transcatheter angiographic embolisation with gelatin sponge and/or steel coil, while effectively controlling bleeding, may also result in gluteal muscle necrosis. Aggressive management including intraarterial antibiotic treatment may have a role, but our numbers are too small to confirm this.

Negative feedback regulation of activated macrophages via Fas-mediated apoptosis.

Apoptosis is a critical event for eliminating activated macrophages. Here we show that Fas-mediated apoptosis may participate in the mechanism of negative feedback regulation of activated macrophages. Cytokine-activated macrophages released high levels of nitric oxide (NO) that induced apoptosis in macrophages themselves. This NO-induced macrophage apoptosis was inhibited by a Fas-Fc chimeric molecule that binds to Fas ligand (FasL) and prevents its interaction with endogenous cell surface Fas. High levels of NO stimulated the release of the soluble form of FasL that was inhibited by a matrix metalloproteinase inhibitor KB-8301. High levels of NO also upregulated the expression of Fas mRNA in macrophages. In addition, macrophages isolated from Fas-lacking mice were resistant to NO-induced apoptosis. Finally, inhibition of apoptosis by a caspase inhibitor augmented peroxide production from activated macrophages. These findings suggest that high levels of NO released from activated macrophages may promote the Fas-mediated macrophage apoptosis that may be a negative feedback mechanism for elimination and the downregulation of activated macrophages in the vessel wall.

A giant intramural gastric hematoma successfully treated by transcatheter arterial embolization.

We describe a case of intramural gastric hematoma with hemorrhagic shock caused by the formation of a large hematoma. Computed tomographic and angiographic examinations confirmed the presence of active bleeding into the hematoma. Transcatheter arterial embolization (TAE) was performed for hemostasis. To our knowledge, although 21 cases of intramural gastric hematoma have been reported in the literature, this is apparently the first case treated by TAE. We conclude that TAE is a safe and effective treatment option for intramural gastric hematoma confirmed to be associated with active bleeding into the hematoma.

Enhanced beta-receptor-mediated vasorelaxation in hypoxic porcine coronary artery.

To investigate the beta-adrenoceptor-mediated responses in hypoxic coronary arteries, we studied the effect of isoproterenol (Iso) on isolated porcine coronary arteries contracted with endothelin-1 in media aerated with 0, 5, 7.5, and 95% O(2). The concentration-response curve of Iso was significantly shifted to the left by hypoxia (0 and 5% O(2)). In oxygenated and hypoxic arteries, 3 x 10(-8), 10(-6), and 10(-5) M Iso significantly increased the contents of cAMP. However, there was no difference in the increases of cAMP content induced by 3 x 10(-8) M Iso between oxygenated and hypoxic arteries. The content of cAMP induced by high concentrations of Iso (10(-6) and 10(-5) M) was significantly larger in hypoxic than in oxygenated arteries. Furthermore, the potentiation by hypoxia of the Iso-induced vasorelaxation was inhibited by glibenclamide and depolarization by KCl, but not by removal of endothelium and indomethacin. The vasodilatory response to forskolin and dibutyryl cAMP was unaffected by hypoxia. We conclude that activation of the ATP-sensitive K(+) channel may account for the potentiation of the response to Iso in hypoxic coronary arteries.

[Progress in interventional radiology (IVR) in emergency medicine].

IVR has attracted much attention in Japan over the past decade, and it is expected to be rapidly developed and widely used. Not surprisingly, IVR has already become essential in emergency medicine. This paper addresses IVR of the thoracic and abdominal areas and the pelvis in emergency medicine, in particular the recent IVR focus on the vasculature. CO2-DSA, which enables extravasation and easy detection of a arteriovenous or portal shunt, is also useful in the detection of bleeding in emergency situations. In trauma cases, TAE, originating from an expanded concept of "damage control," is commonly used to stop bleeding in order to perform surgical treatment or used during surgery. Occasionally the two applications are combined when appropriate. TAE is effective in controlling retroperitoneal bleeding resulting from pelvic fracture and parenchymatous organ injuries in the abdominal area. Treatment with stent-grafts, originally used to treat true aneurysms, has recently been used for treatment of injuries of the aorta or arteries and for entry closure due to aortic dissection. Furthermore, stent placement is expected to become an effective cure for organ ischemia, resulting from acute dissections. Is addition, in order to cure rupture of esophagus or gastric varices, such new treatments as TIPS and BRTO have increasingly been used, coupled with the conventional PTO treatment. Continuous regional arterial infusion of protease inhibitor, in an attempt to cure severe acute pancreatitis, significantly reduced the infectious rate at the necrotic lesion, and its resulting mortality rate. It is certain that great progress has been made in emergency medicine. We also should realize that it is desirable to be well versed even in new IVR.

Stent grafting for aortic dissection.

We report the successful treatment of a patient with Stanford type B aortic dissection, "thrombosed" type with ulcer-like projections, by insertion of a stent-graft. The false lumen completely disappeared within 1 year after surgery. This maturing procedure is promising in the treatment of thrombosed, aggravated aortic dissection.

Endothelin-1 enhances nitric oxide-induced cell death in cultured vascular smooth-muscle cells.

Increased expression of endothelin-1 (ET-1) immunoreactivity is demonstrated in the active atherosclerotic plaque. Here we show that both ETA and ETB receptors are expressed in rat vascular smooth-muscle cells (VSMCs). ET-1 binding to ETB receptors enhances nitric oxide-induced cell death in VSMCs. These findings suggest that ET-1 may participate in the mechanism of cell death (apoptosis) in the plaque through activation of ETB-mediated pathways and that a selective ETB receptor antagonist could be useful in preventing acute plaque alterations, such as plaque rupture.

Interleukin-2 modulates the responsiveness to angiotensin II in cultured vascular smooth muscle cells.

Preincubation with interleukin-2 (IL-2), a T cell-derived cytokine, enhanced the increase in intracellular Ca2+ ([Ca2+]i) induced by angiotensin II (AII) in vascular smooth muscle cells (VSMC). IL-2 itself did not affect the basal [Ca2+]i level or the maximal response of [Ca2+]i increase induced by AII. Furthermore, IL-2-induced enhancement was not observed in the absence of extracellular Ca2+, suggesting that IL-2 enhances Ca2+ influx induced by AII. IL-2 also enhanced the stimulation of DNA synthesis induced by AII, although IL-2 alone did not stimulate DNA synthesis. Genistein, an inhibitor of protein tyrosine kinases, significantly inhibited IL-2-induced enhancement of both Ca2+ influx and DNA synthesis induced by AII. A neutralizing antibody against heparin-binding epidermal growth factor-like growth factor (HB-EGF) partially inhibited IL-2-induced enhancement of DNA synthesis induced by AII. These findings suggest that autocrine HB-EGF is partially involved in the mechanism of IL-2-induced enhancement of DNA synthesis. On the other hand IL-2 stimulated both glycosaminoglycan (GAG) and prostacyclin syntheses and enhanced the stimulation of both GAG and prostacyclin syntheses induced by AII. Therefore, IL-2 may play important roles in the pathogenesis of atherosclerosis and vascular disease by modulating the responsiveness to AII in VSMC.

[Diagnostic accuracy of 201T1 SPECT.MRI in brain diseases and inter-reader variance of diagnostic performance].

Fifteen-four studies of 201T1 brain tumor SPECT were independently interpreted by 9 nuclear medicine physicians with and without reference magnetic resonance images in 2 separate sessions to define an effect of referring images, and inter-observer variations. The physicians were requested to detect foci of abnormal deposits, and to discriminate whether they were malignant or not according to 5-grade scaling of subjective diagnostic confidence. Receiver-operating characteristics (ROC) analysis was performed. Mean sensitivity for presence of lesions (SEP), and sensitivity and specificity for malignancy of 201T1 SPECT were 84, and 53 and 55%, which were changed to 94, and 74 and 55% after referring to the MR images. The SFP was significantly improved (p < 0.05), but sensitivity and specificity for malignancy, assessed by areas under the ROC curves, were not significantly improved. Inter-observer variation of the SFP was significantly reduced with addition of the referring MR images. Cerebral lobar localization of lesions by SPECT showed great inter-observer variations (true localization ranged from 30 to 68.4%). It is concluded that 201T1 brain tumor SPECT has moderate sensitivity and specificity for malignancy, which is not improved by addition of anatomical reference images, that additional MR images reduce inter-observer variation of confidence on lesion presence, and that SPECT localization of lesions has great inter-observer variations.

Anti-IRS-1 monoclonal antibody, 6G5, cross-reacts to IRS-2.

We previously reported the production of anti-IRS-1 monoclonal antibodies against human IRS-1 C-terminal portion. One of anti IRS-1 monoclonal antibodies, 6G5, was found to immunologically cross-react with IRS-2, which has been reported recently. The data presented here provide information arising from the use of the anti-IRS-1 MAb, 6G5; this MAb was found to be a useful reagent in studying the functional role of IRSs in the insulin-signaling system.

Ornithine decarboxylase induction during liver regeneration in IRS-1-deficient mice.

We investigated the induction of ornithine decarboxylase during liver regeneration after partial hepatectomy in IRS-1-deficient mice. There were no significant differences in ODC activity or the time course of changes in ODC activity between IRS-1-deficient mice and wild-type mice. PI 3'-kinase activity showed similar increases in both groups of mice. Furthermore, ODC induction in IRS-1 transfected CHO cells was studied after stimulation by addition of FCS. The maximal ODC activity was 2.5-fold greater in IRS-1-transfected CHO cells than in control CHO cells. Our results suggest that the IRS-1 pathway may be involved in ODC induction. The absence of a difference in ODC and PI 3'-kinase activity in the regenerating liver between IRS-1-deficient mice and wild-type mice may have been related to the compensatory effects of IRS-2/pp190 [Araki et al. Nature (1994) 372, 186-190; Tobe et al. J.Biol.Chem. (1995) 270, 5698-5701].

[Usefulness and limitation of digital rectal examination and imaging studies in staging prostate cancer].

The diagnostic usefulness of digital rectal examination (DRE), transrectal ultrasonography (TRUS), magnetic resonance imaging (MRI) and computed tomography (CT) was compared in the differentiation of stage B from stage C prostate cancer. Eighteen patients who had undergone radical retropubic prostatectomy were included in this study. Overall, the positive predictive values (PPV) for detecting extraprostatic disease (extracapsular extension, seminal vesicle invasion) were 100% for DRE, 88.9% for TRUS and 80.0% for MRI, respectively. Corresponding figures for accuracy in detecting extraprostatic spread were 55.6%, 66.7% and 61.1%, respectively. The PPV and accuracy for detecting extraprostatic disease in 13 patients with localized cancer (< stage B) were 75.0%, 53.8% for TRUS and 66.7%, 53.8% for MRI, respectively. Both of these examinations appeared to be superior to DRE alone. The PPV and accuracy increased when findings on TRUS and MRI coincided. Computed tomography was less accurate than MRI in diagnosing nodal involvement because of the higher incidence of false positives. Further efforts should be focused on enhancing preoperative diagnostic precision in staging prostate cancer because of the limited usefulness of the current imaging techniques. Development of more reliable diagnostic modalities or designing ideal combination of these studies are desperately needed.

[Phase analysis of gated blood pool scintigraphy in traumatic myocardial contusion].

It is not easy to make a diagnosis of myocardial contusion following blunt chest trauma, because most patients have many other concurrent injuries with diverse symptoms. The usefulness of phase analysis of gated blood pool scintigraphy (GBPS) for myocardial contusion following blunt chest trauma was evaluated. Thirty-eight patients who had been strongly suspected of having myocardial contusion from clinical symptoms and electrocardiograms underwent phase analysis of GBPS. The results of phase analysis were compared with those of two-dimensional echocardiography (2-D Echo) and CPK-MB fraction measurement in all patients, with those of 201TlCl myocardial scintigraphy in 35 patients and with those of 99mTc-pyrophosphate scintigraphy in 10 patients. In 29 patients (76.3%), the results of phase analysis matched those of 2-D Echo. Two patients (5.3%) who were judged as positive by 2-D Echo and as negative by phase analysis had only rupture of the chordae. Only one of two other patients who were judged as negative by 2-D Echo and as positive by phase analysis was judged as positive by 201TlCl myocardial scintigraphy. The results of both 2-D Echo and phase analysis were not well correlated with those of CPK-MB fraction measurement and 99mTc pyrophosphate scintigraphy. It is concluded that phase analysis of GBPS, as well as 2-D Echo, is useful for diagnosing myocardial contusion, and that phase analysis is most useful for diagnosing myocardial contusion in patients who cannot be examined by 2-D Echo because of the presence of pneumothorax and/or subcutaneous emphysema in the anterior chest wall.

[Clinical evaluation of hepatic scintigraphy using 99mTc-GSA].

Functional hepatic imaging was performed using 99mTc-DTPA-galactosyl human serum albumin (99mTc-GSA), a radiolabeled ligand that reacts specifically to the asialoglycoprotein receptor that resides at the plasma membrane of hepatocytes, in 21 patients: five with chronic active hepatitis (CAH), 14 with compensative liver cirrhosis (LC), one with chronic inactive hepatitis and one with acute hepatitis. The former two diseases were mainly investigated. Serial liver images were acquired at the rates of 10 sec/frame for 0-5 min and 2 min/frame for 6-30 min after the injection of 99mTc-GSA, and the images were compared with 99mTc-phytate images in 2 patients with CAH and 11 with LC, and those with portal scintigrams using 123I-iodoamphetamine (IMP) in 3 patients with LC. The images using 99mTc-GSA were in better agreement with hepatic function than those using 99mTc-phytate, and with the findings of portal scintigraphy using 123I-IMP. LHL15 (liver/liver and heart radioactivities at 15 min after the injection of 99mTc-GSA) correlated with the hepaplastin test (r = 0.978 in CAH, and r = 0.544 in LC), indicators of hepatic reserve. These results suggest that liver scintigraphy using 99mTc-GSA might be a useful method for evaluating liver function.