[Atherectomy in patients with arteriosclerosis obliterans: angiographic follow-up study of 186 lesions in 146 patients]

Atherectomy (ATE) is a new catheter-mediated technique for the removal of atheroma in patients with arteriosclerosis obliterans (ASO). ATE was performed using 7-10 Fr. Simpson Peripheral Athero Track catheters at 186 sites in 146 patients, whose lesions involved 49 common iliac arteries, 66 external iliac arteries, 68 femoral arteries and three other arteries. The initial success rate was 94.1%. The mean percent of the diameter stenosis was reduced from 79.0 +/- 1.2% (mean +/- SD) to 22.7 +/- 1.0%. There were two cases of perforation that required surgical treatment (1.1%). The complication rate was 4.4%. The 0.5-, 1-, 2- and 3-year patency rates were 87.6%, 79.6%, 62.5% and 62.5%, respectively. The rate of long-term patency in each segment of arterial lesions revealed that the patency rate in the common iliac artery was significantly higher than the rates in the external iliac artery (p < 0.05) and femoral artery (p < 0.01). The patency rates for long lesions (> or = 2.0 cm) and occluded lesions were significantly (p < 0.01) lower than those for short lesions (< 2.0 cm). Diabetic patients had a higher re-stenosis rate than nondiabetic patients (p < 0.05). In conclusion, ATE is an effective new method for the treatment of patients with ASO.

(+)-cis-3,5-dimethyl-2-(3-pyridyl) thiazolidin-4-one hydrochloride (SM-12502) as a novel substrate for cytochrome P450 2A6 in human liver microsomes

(+)-cis-3,5-dimethyl-2-(3-pyridyl)thiazolidin-4-one hydrochloride (SM-12502) was oxidized by human liver microsomes to produce the S-oxide as a sole metabolite. Indirect evidence suggested that the S-oxidation was catalyzed by cytochrome P450 (CYP). Eadie-Hofstee plots showed biphasic pattern, suggesting that at least two enzymes were involved in the S-oxidation in human liver microsomes. Kinetic parameters of the S-oxidase with high-affinity showed Km and Vmax values of 20.9 +/- 4.4 microM and 0.111 +/- 0.051 nmol/min/mg microsomal protein, respectively. The S-oxidase activity was inhibited by coumarin and anti-CYP2A antibody. Among the contents of forms of CYP 20 samples of human liver microsomes, the content of CYP2A6 correlated with S-oxidase activity measured with 50 microM SM-12502 (r = .808, P < .0005). A close correlation (r = .908, P < .0001) was observed between activities of SM-12502 S-oxidase and coumarin 7-hydroxylase. Microsomes from genetically engineered human B-lymphoblastoid cells expressing CYP2A6 metabolized SM-12502 to the S-oxide efficiently. The results indicate that CYP2A6 isozyme is a major form of CYP responsible for the S-oxidation of SM-12502 in human liver microsomes. Thus, SM-12502 will be a useful tool in further research to analyze a human genetic polymorphism of CYP2A6.

Effects of serotonin on the release of thyrotropin-releasing hormone from the rat retina in vitro

Effects of serotonin on the release of thyrotropin-releasing hormone (TRH) from the rat retina were studied in vitro. The retina was incubated in medium 199 (pH 7.4) with 1.0 mg/ml of bacitracin and 100 micrograms/ml of ascorbic acid (medium) for 20 min. The amount of TRH release into the medium was measured by radioimmunoassay. The TRH release from the rat retina was inhibited significantly in a dose-related manner with the addition of serotonin and enhanced with cyproheptadine. The inhibitory effect of serotonin on TRH release from the retina was blocked with the addition of cyproheptadine. The elution profile of methanol extract of the rat retina was identical to that of synthetic TRH. The findings suggest that the serotonergic system inhibits TRH release from the rat retina in vitro.

[Clinical features of anterior inferior cerebellar artery territory infarcts--a study of ten patients]

Clinical features of the anterior inferior cerebellar artery (AICA) territory infarcts were investigated in ten patients, ranging in age from 38 to 76 years. In all patients, there were MR images of infarction located in the area supplied by the AICA. The lesion was on the left side in 6 patients and right side in 4. The lesion of brain stem including the middle cerebellar peduncle was found in 7 patients and that extended to the cerebellum was in 3 patients. The main ipsilateral neurological signs were the VII and VIII cranial nerves palsy and cerebellar ataxia. The V and VI cranial nerves palsy. Horner's syndrome, and dysphagia were also present. The main contralateral sign was superficial sensory disturbance, but no hemiplegia. The underlying pathology included chiefly hyperlipidemia, hypertension, and diabetes mellitus. Cerebral angiography was performed in 8 patients, most of which was observed severe arteriosclerosis suggesting poor hemodynamics in the vertebral and basilar arteries. The prognosis was relatively good, but the VII, VIII, and V cranial nerves palsy and contralateral superficial sensory disturbance remained as the sequelae. As mentioned above, there were various neurological findings and MR images in AICA territory infarcts. Especially there were some patients whose lesion extended to the upper medulla and neurological findings were similar to the Wallenberg syndrome. It is important that one investigates not only axial slices but also coronal slices of MR image to estimate the extension of AICA territory infarct.

Hepatic release of endothelin-1 after warm ischemia. Reperfusion injury and its hemodynamic effect

This study investigated the release of endothelin (ET)-1 from the liver after warm ischemia/reperfusion (I/R) injury. Wistar rats were subjected to 120 min of warm hepatic ischemia by clamping the hepatic hilum under porto-jugular shunting. Reperfusion was performed by unclamping. The rats were divided into 2 groups receiving intravenous treatment with an anti-ET-1 mAb before ischemia (AET group) and with mouse immunoglobulin G (sham group). Hepatic blood flow was assessed by laser-Doppler flowmetry and reflectance spectrophotometry and was compared between the 2 groups along with the bile flow rate. The ET-1 concentrations of hepatic venous and portal blood were determined in the sham group, and the portal blood endotoxin levels were assayed in both groups. Both groups developed transient hypotension after reperfusion, but hepatic blood flow subsequently showed a significant improvement in the AET group. Hepatic congestion was detected in the sham group by both reflectance spectrophotometry and histological examination. After reperfusion, bile flow was significantly greater in the AET group. The portal endotoxin concentration showed no increase in both groups, and the hepatic venous blood ET-1 level in the sham group was significantly higher until 3 hr after reperfusion compared to the portal blood level. The 30-day survival rate was 50% in the AET group, whereas all the sham rats died within 12 hr. ET-1 was released from the liver after I/R injury and apparently participated in systemic and local hemodynamic changes that affected survival.

High levels of serum lipoprotein(a) in patients with ischemic heart disease with normal coronary angiogram and thromboangiitis obliterans

To determine whether lipoprotein(a) (Lp(a)) contributes to the acceleration of cardiovascular diseases without atherosclerotic lesion, we have measured serum Lp(a) level in male subjects aged 40-69 years with thromboangiitis obliterans (n = 40) and ischemic heart disease (IHD) with normal coronary angiogram (n = 35) in addition to subjects with arteriosclerosis obliterans (n = 123) and IHD with atherosclerotic coronary lesion (n = 203). Cases who had no IHD, arteriosclerosis obliterans or thromboangiitis obliterans were selected as a control group (n = 316). Subjects without any diseases or abnormal findings in physical examination and laboratory data were selected from the control group as the healthy control group (n = 156). The Lp(a) levels of arteriosclerosis obliterans and IHD with atherosclerotic coronary lesion were significantly higher (17.0 mg/dl and 13.1 mg/dl; median) than those of control and healthy control groups (9.9 mg/dl and 9.4 mg/dl, respectively) (P < 0.01), in agreement with previous reports. Furthermore, the Lp(a) level of IHD with normal coronary angiogram group was significantly higher (18.9 mg/dl) than those of the control and healthy control groups (P < 0.05). The Lp(a) level of thromboangiitis obliterans group was also much higher (21.3 mg/dl) than that of the healthy control group (P < 0.05). The current study suggests that Lp(a) is one of the independent risk factors for the development of atherosclerotic diseases such as arteriosclerosis obliterans and IHD with atherosclerotic coronary lesion.(ABSTRACT TRUNCATED AT 250 WORDS)

The role of endothelin in the pathophysiology of renal impairment during acute liver rejection

We assessed the role of endothelin in the development of renal dysfunction during acute rejection by examining the effect of a selective endothelin A (ETA) receptor antagonist BQ-123 in rats with acute liver rejection. Serum endothelin levels and endogenous creatinine clearance (Ccr) were monitored on days 1, 3, 5, 7, and 9 postoperatively. As indicators of renal hemodynamics, the estimated hemoglobin concentration of renal tissue (IHb) and the oxygen saturation of hemoglobin in renal blood (ISO2) were determined by reflectance spectrophotometry. In addition, the clearance of inulin and P-aminohippurate were determined, and the renal tissue blood flow was estimated by laser-Doppler flowmetry (LDF). As a model of allograft rejection, Lewis rats were transplanted orthotopically with DA rat livers. The serum endothelin level of allografted rejectors was significantly (P < 0.05) higher than that of isografted controls (Lewis rats with Lewis livers) on postoperative day 5, and it increased to a maximum of 5.38 +/- 0.95 pg/ml on day 9 (versus 1.23 +/- 0.18 pg/ml preoperatively). The values of Ccr, IHb, and ISO2 were all significantly (P < 0.05) lower in allografted rejectors than in isografted controls on day 5, and subsequently declined to a minimum on day 9 (P < 0.01). Treatment of allografted rejectors with BQ-123 markedly improved the renal parameters to levels similar to those in the isografted controls. These results strongly suggest that endogenous endothelin may play an important role in the development of renal impairment during acute liver rejection by reducing renal blood flow through binding with ETA receptor.

Hepatopancreatoduodenectomy for advanced gallbladder carcinoma

OBJECTIVE

To assess the effectiveness of hepatopancreatoduodenectomy (HPD) in patients with advanced gallbladder carcinoma directly invading the liver and pancreas, generally considered to be nonresectable.

PATIENTS AND METHODS

Sixty patients with gallbladder carcinoma admitted to our hospital from 1978 to 1992, of whom 55 had Nevin stage V carcinoma and 21 had resectable tumors. Of these patients, seven underwent HPD. The remaining 34 patients had nonresectable tumors. The outcomes of patients undergoing HPD and those with nonresectable tumors were compared and the effect on their quality of life was also analyzed.

RESULTS

Postoperative complications occurred in five of the seven patients after HPD, but there were no operative deaths. The 1- and 2-year survival rates were 57% and 28.6%, respectively, with a median survival time of 12 months. In contrast, the 1- and 2-year survival rates of the 34 patients with nonresectable tumors were both 5.8%, and the median survival time was 2 months. The median and mean durations of home stay after HPD were 6 and 10.5 months, respectively.

CONCLUSION

Hepatopancreatoduodenectomy has the potential to improve both survival and the quality of life for carefully selected patients with advanced gallbladder carcinoma.

[Spectrophotometric determination of uric acid in serum using a titanium (IV)-porphyrin complex]

Aqueous solution of oxo[5,10,15,20-tetra(4-pyridyl)porphyrinato]titanium (IV) complex, a Ti-TPyP reagent, was found to be very useful for the spectrophotometric determination of hydrogen peroxide. The reagent (lambda max 432 nm) reacts with hydrogen peroxide to form a monoperoxocomplex, resulting in a significant decrease of the absorbance at 432 nm. The decrease (delta A) in absorbance was proportional to the concentration of hydrogen peroxide. The Ti-TPyP reagent was successfully applied to the assay of uric acid in the serum, using uricase to produce hydrogen peroxide through enzymatic oxidation. Using only 5 microliters serum, a linear relationship was obtained between delta A and uric acid concentration in the serum ranging from 5 x 10(-6) to 1 x 10(-3) M. The apparent molar delta A of uric acid was 2.2 x 10(5) M-1 cm-1. The relative standard deviation of repeated runs (n = 8) was 2.8% at 3.77 x 10(-4) M uric acid. The analytical recovery of uric acid (5 x 10(-4) M) added to the serum was 96.8 to 105.0%. No pre-concentration and deproteinization were required to determine uric acid in the serum by the present method because of the high sensitivity and selectivity of the Ti-TPyP reagent for hydrogen peroxide.

Functional abnormalities of sinusoidal endothelial cells in rats with acute liver rejection

The purpose of this study was to determine the changes of hepatic sinusoidal endothelial cell (SEC) function in acute liver rejection with respect to receptor-mediated endocytosis. Orthotopic rat liver transplantation was performed in Lewis rats grafted with DA livers and in Lewis rats grafted with Lewis livers as rejectors and controls, respectively. Animals were killed at 1, 3, 5, 7, and 10 days after the operation. Fc receptors (FcRs) were histochemically stained on frozen liver sections by applying peroxidase-antiperoxidase IgG complex as a ligand, and the FcR activity, i.e., capacity of binding the ligands represented by the FcR staining intensity, was semiquantitatively analyzed as an indicator of SEC function. The serum level of hyaluronic acid, which is specifically cleared from the circulation by receptor-mediated SEC endocytosis, was also assayed, along with the total serum bilirubin. Three days after the operation, the SECs of rejectors showed a significantly weaker FcR staining intensity of about half the value of that seen in the controls (P < 0.05), and staining disappeared after 5 days (P < 0.01). The decrease of FcR staining intensity, i.e., FcR activity, showed a correlation with elevation of the serum hyaluronic acid level (r = -0.77; P < 0.001). Histological evidence of endothelialitis and a significant elevation of total serum bilirubin (P < 0.01) were also present at 3 and 5 days, respectively. These results suggest that impairment of the endocytic function of SECs occurs at an earlier phase of acute liver rejection when compared with development of abnormalities of traditional indicators. Determination of receptor-mediated SEC endocytic functions may thus provide useful information for the early diagnosis of acute rejection.