[Evaluation of concomitant use of cyclosporin and percutaneous isolated liver perfusion under complete venous isolation and charcoal hemoperfusion]

It is difficult to administer an effective dose of cyclosporin A (CsA), a potent inhibitor of P-glycoprotein, to prevent multiple drug resistance due to its side effect. We herein evaluated the efficacy of concomitant use of this agent and complete hepatic venous isolation and charcoal hemoperfusion (HVI.CHP). Dogs were divided into two groups; group I (n = 4), intraarterial infusion of only adriamycin (ADM) and group II (n = 4), intraarterial infusion of CsA and ADM. In both groups, ADM was intraarterially administered for 10 minutes under HVI.CHP. In addition, in group II, CsA infusion (0.3 mg/min.kg) was initiated 20 min prior to the start of ADM infusion and maintained for 30 min. The AUC (micrograms.min/ml) of ADM were 21.2 +/- 8.6 (mean +/- SD) and 28.4 +/- 10.3 in groups I and II, respectively, at prefilter (hepatic venous level) and 8.1 +/- 4.6 and 4.8 +/- 3.8, respectively, at postfilter, showing an effective drug elimination in both groups. The Cmax (micrograms/ml) were 14.1 +/- 2.2 at prefilter, 2.4 +/- 0.5 at postfilter, and 3.4 +/- 1.2 in systemic level. These results indicated that HVI.CHP allowed the high-dose CsA infusion required for P-gp inhibition in the liver and could reduce extraregional CsA leakage.

[A case of advanced hepatoma cured by repeated percutaneous isolated liver perfusion using hepatic venous isolation and charcoal hemoperfusion]

We have reported the treatment results of percutaneous isolated liver perfusion using hepatic venous isolation and charcoal hemoperfusion (HVI.CHP) for unresectable liver cancers. This is a case of multiple advanced hepatoma cured completely by repeated per cutaneous isolated liver perfusion. The patient was a 58-year-old woman who was referred to our hospital for a hepatic tumor detected by abdominal computed tomograpy (CT). On admission, she showed HBs antigen positive, mild anemia and liver dysfunction, and elevation of tumor markers. Abdominal CT demonstrated nodular tumors in segment 4. In addition, hepatic angiography additionally revealed multiple bilobar metastases. We treated this case with high-dose intraarterial adriamycin (150 mg/body) using HVI.CHP. There after, the patient received intermittent intraarterial low-dose epirubicin infusions (30 mg/body, 5 times) via an implantable catheter system. Furthermore, she was given a second high-dose of adriamycin (130 mg/body) under HVI.CHP 7 months after the first treatment. Despite repeated high-dose treatments, she had no severe side effects. The levels of tumor markers, including AFP and PIVKA-II, decreased to normal range, and all tumor nodules have disappeared in abdominal CT studies at present, 20 months after the initial treatment. In conclusion, our experience suggests that advanced hepatoma with multiple bilobar lesions, as in this case, would be cured by repeated percutaneous isolated liver perfusion using HVI.CHP.

[A case of advanced cholangiocellular carcinoma treated successfully by percutaneous isolated liver perfusion with cisplatin]

Herein reported is a case with unresectable intrahepatic cholangiocellular carcinoma (CCC) treated successfully with high-dose cisplatin infusion under hepatic venous isolation and charcoal hemoperfusion (HVI.CHP). The patient was a 43-year-old woman, who was investigated for liver dysfunction and subsequently referred to our institution with a diagnosis of unresectable intrahepatic CCC. We gave this patient a total of 2 treatments of percutaneous isolated liver perfusion with HVI.CHP (a total dose of cisplatin, 400 mg and adriamycin 30 mg). Although she had a slight elevation of serum GOT levels, leukopenia and renal dysfunction did not occur throughout the posttreatment course. The level of DUPAN-2 after the first treatment showed a marked reduction to 910 U/ml, from a pretreatment level of 2,700 U/ml. Abdominal CT scan also demonstrated a remarkable regression of liver tumors (PR: volume reduction, 76%). In conclusion, in percutaneous isolated liver perfusion using HVI.CHP, we have safely accomplished a dose intensification of intraarterial cisplatin. The treatment resulted in a marked tumor regression. Therefore, we consider that this method offers an effective therapeutic option for unresectable CCC.

2-oxoacid:ferredoxin oxidoreductase from the thermoacidophilic archaeon, Sulfolobus sp. strain 7

The purified 2-oxoacid:ferredoxin oxidoreductase of a thermoacidophilic and aerobic crenarchaeote, Sulfolobus sp. strain 7, consists of 70-kDa alpha and 37-kDa beta subunits, and contains one thiamine pyrophosphate (TPP), one [4Fe-4S]2+.1+ cluster, and two magnesium atoms per alpha beta structure. It exhibits a broad substrate specificity toward 2-oxoacids such as 2-oxoglutarate, 2-oxobutyrate, and pyruvate. The gene encoding the archaeal oxidoreductase was cloned, and the two open reading frames encoding the alpha (632 amino acids) and beta subunits (305 amino acids), respectively, were sequenced. Careful sequence alignment revealed several consensus motifs of this enzyme family, as well as possible cofactor binding residues of the Sulfolobus enzyme. This new structural information also indicates that (i) several genetic fusions and reorganization of the early, possibly alpha beta gamma delta-type enzyme similar to those from hyperthermophiles have taken place during evolution of the 2-oxoacid:ferredoxin (flavodoxin) oxidoreductase superfamily, which might have occurred in different ways in early aerobic archaea and early anaerobic bacteria, and that (ii) enzymes with different subunit compositions should have an essentially similar catalytic mechanism with one TPP and at least one [4Fe-4S] cluster as the minimal set of redox centers.

[Evaluation of a single catheter technique for percutaneous isolated liver perfusion]

We have established a single catheter technique of percutaneous isolated liver perfusion using a 4-lumen-2-balloon (4L - 2B) catheter for treatment of unresectable malignant liver tumors. Herein reported are the technique, safety and pharmacokinetics of the system in comparison with the original double-balloon technique. This study included 19 patients with malignant liver tumors treated by adriamycin at a dose of 100 mg/m2. Seven patients had the double-balloon technique (group D), in which filtered hepatic effluent and the rest of the inferior vena caval blood were separately drawn and returned to the left axillary vein. The other 12 patients had single catheter technique (group S). In group S, hepatic effluent was solely isolated and directed to CHP filters. All patients except for one in group S showed good hemodynamic stability. The hepatic venous flow rate of group S was significantly higher than in group D (p < 0.05). Although the mean area under the time concentration curve at systemic serum was significantly lower in group S compared to group D, the rate of side effects was similar in both groups. A 4L. 2B single catheter allowed safe and repeated percutaneous isolated liver perfusion for technical simplification of the treatment.

[The effect of high-dose intraarterial chemotherapy with percutaneous hepatic venous isolation and charcoal hemoperfusion (HVI.CHP) for unresectable multiple hepatocellular carcinoma--comparison with other therapeutic modalities]

We evaluated the therapeutic effect of HVI.CHP in 11 patients with Stage III and IVA multiple hepatocellular carcinoma (group H) in comparison with conventional intraarterial chemotherapy (group S, 12 patients) and transarterial embolization (TAE; group T, 15 patients). The patients in each group had the same background as group H in terms of liver function tests. The Vp3 positive rates in group H (37%) and group S (47%) were significantly higher than group T (0%). One-year survival rates of groups H, S and T were 63. 6%, 8.3% and 46.7%, respectively, and 2-year survival rates were 63.6%, 0% and 20%, respectively. A significant difference was seen between the survival curves of groups H and S (p < 0.01), whereas no significant differences were detected between those of groups H and T. The survival rates for stage IVA patients in groups H, S and T were 55.6%, 10% and 40%, respectively, for 1 year and 55.6%, 0% and 10%, respectively, for 2 years. The difference of survival curves between Stage IVA patients of each group was analogous to those between overall patients of each group. Although 4 patients with Vp3 were included in group H but none in group T, the survival rates of group H were rather higher than in group T at 2 years. These data suggest that HVI.CHP could be the treatment of choice for unresectable multiple hepatocellular carcinoma.

Effects of chronic hypertension and left ventricular hypertrophy on the extent of infarct expansion in rats

Left ventricular hypertrophy is an adaptive response to long standing hypertension. However, the influence of left ventricular hypertrophy with hypertension on extent of infarct expansion has not been studied. We compared the effects of left ventricular hypertrophy with hypertension on infarct expansion in spontaneously hypertensive rats (SHR, n = 76), Wistar-Kyoto rats (WKY; n = 46) and spontaneously hypertensive rats treated with delapril, an angiotensin converting enzyme (ACE) inhibitor (SHRD; n = 39). The survival rates at 7 days after myocardial infarction were 41%, 24%, and 46% for WKY, SHR, and SHRD. The survival rate of SHR was significantly lower than those of both SHRD and WKY (P < .05). In the surviving rats (18 SHR, 19 WKY, 18 SHRD), both left ventricular cavity area (LCVA) and the infarct segment length per the noninfarct segment length (FW/IVS), measured as indices of left ventricular dilation, were significantly less in SHR and SHRD than in WKY, and the thickness of the left ventricular free wall (Wth), used as an index of left ventricular thinning, was significantly higher in both SHR and SHRD than in WKY (P < .01). However, there was no significant difference in FW/IVS, LCVA, and Wth between SHR and SHRD. Hemodynamic findings 1 week after coronary occlusion demonstrated that all rats were in heart failure, and there were no significant differences in hemodynamics among the three groups. In conclusion, our findings showed that hypertrophy with hypertension reduced infarct expansion, but that reduction of blood pressure by ACE inhibitor did not reduce infarct expansion more than hypertrophy did. However, this finding suggest that an ACE inhibitor may improve the rate of survival of patients with left ventricular hypertrophy with hypertension.

Myocardial infarction in rats: high-resolution single-photon emission tomographic imaging with a pinhole collimator

The purpose of this study was to evaluate the accuracy of myocardial imaging by means of high-resolution single-photon emission tomography (SPET) with a pinhole collimator in rats with experimental infarction. Myocardial infarctions were induced in male Wistar rats by ligation of the left coronary artery for 30 min, followed by reperfusion. Two days after the reperfusion, pinhole SPET was performed after the intravenous administration of 111 MBq of thallium-201 chloride, using a rotating gamma camera equipped with a pinhole insert (2.0-mm aperture) in a low-energy pinhole collimator. SPET projection data were collected at 6 degrees increments over 360 degrees using a 4-cm radius of rotation to reconstruct the short- and long-axis images. Projection data were acquired in 15 or 30 s, the SPET imaging being accomplished within 40 min after the injection of 201Tl. After SPET, the rats were sacrificed to remove the hearts for autoradiography (ARG) and nitroblue tetrazolium (NBT) staining as a visual correlative study. Quantitative correlative studies between pinhole SPET and ARG were performed with linear regression analysis for infarct size and distribution properties (relative counts on SPET images and relative density on autoradiographs) on the short-axis sections. All infarcts (4 mm in minimum diameter) in seven rats were detected by pinhole SPET. The SPET images in rats with or without myocardial infarction were consistent with the findings of ARG and NBT staining. There were significant correlations between pinhole SPET and ARG with respect to the infarct size (r=0.933, P <0.001; n=15) and the relative radiotracer distribution (r=0.931, P <0.001; n=68). This study therefore confirmed the accuracy of myocardial pinhole SPET imaging in rats with myocardial infarction. This method may partially substitute for ARG and prove useful for assessing new myocardial imaging agents in vivo in small laboratory animals.

Novel selective PDE IV inhibitors as antiasthmatic agents. Synthesis and biological activities of a series of 1-aryl-2,3-bis(hydroxymethyl)naphthalene lignans

A series of 1-aryl-2,3-bis(hydroxymethyl)naphthalene lignans have been synthesized and evaluated for their ability to selectively inhibit PDE IV isolated from guinea pig. Replacement of the 1-phenyl ring by a pyridone ring led to marked improvement of their selectivity for PDE IV over PDE III. The compounds that were most potent and selective involved those bearing an N-alkylpyridone ring at C-1. These compounds also showed potent antispasmogenic activity without causing significant changes in heart rate in the guinea pig. The most potent compound was 6,7-diethoxy-2, 3-bis(hydroxymethyl)-1-[1-(2-methoxyethyl)-2-oxo-pyrid-4-yl]nap hth alene (17f), ED50 values of histamine-induced and antigen-induced bronchoconstriction in the guinea pig being 0.08 and 2.3 mg/kg iv, respectively. This compound was chosen as a candidate for further pharmacological evaluation.

The guanine nucleotide-binding regulatory proteins (G proteins) in myocardium with ischemia

Guanine nucleotide-binding regulatory proteins (G proteins) play a major role in the regulation of a number of physiological processes, such as stimulation or Inhibition of adenylate cyclase activity or gaiting of ionic channels. Myocardial ischemia could induce the changes in receptor-G protein signal transduction system in the heart. Therefore, this article will focus on the role and alterations of G proteins (especially, Gs and Gi) in myocardial ischemia. The Gi protein rapidly loses functional activity during very early myocardial ischemia. In contrast to Gi protein, the function of Gs protein during this phase has not been evaluated. Moreover, the changes in Gs protein after 30 min of ischemia are contradictory. However, the sensitization of the adenylate cyclase activity in the very early phase of acute ischemia is gradually replaced by a decrease in adenylate cyclase activity with prolonged ischemia. The decrease in the function and amount of Gs protein may be one of the factors that induce these changes. The function of Gs protein was also decreased in the canine hearts with ischemia and reperfusion. In contrast to ischemia and reperfusion, there are no significant alterations in G proteins and modulation of adenylate cyclase in the stunned myocardium. It has become increasingly evident that Gi protein may play an important role in the cardioprotective effects of preconditioning. When beta-adrenoreceptor densities are reduced in chronic myocardial ischemia, decreased in the amount and function of Gi protein and increased amount of Gs protein may play the role in preservation of the adenylate cyclase activity. These alterations in G proteins may play the important role in the myocardial function during myocardial ischemia.

Hair follicle involvement in herpes zoster: pathway of viral spread from ganglia to skin

Herpes zoster is caused by reactivation of varicella-zoster virus (VZV) persisting in dorsal root or trigeminal ganglia. To clarify the pathway of viral spread from the ganglia to skin, 16 biopsy specimens of early skin lesions of herpes zoster obtained from the face and trunk of 13 patients were studied histologically and immunohistochemically using monoclonal antibodies to the structural proteins of VZV. VZV-infected cells were detected in the hair follicles in 10 of the 16 specimens and in the epidermis in 2 specimens. Infected cells were localized in the isthmus of every involved follicle (12/12), frequently in the stem (8/10) and infundibulum (6/10), and never in the bulb. The high frequency of follicular involvement in herpes zoster suggests that VZV spreads to the area of skin innervated by myelinated nerves, which end around the isthmus of hair follicles and sebaceous glands.

A rare case of serous cystadenoma of the pancreas presenting with left-sided portal hypertension

We herein report the case of a 63-year-old woman with a serous cystadenoma of the pancreas presenting with left-sided portal hypertension secondary to isolated splenic vein occlusion. She was admitted to our hospital for sudden hematemesis. Emergency upper gastrointestinal endoscopy revealed hemorrhagic erosive gastritis and isolated varices in the gastric fundus. An abdominal angiographic study disclosed a large hypervascular tumor of the pancreatic tail which caused isolated splenic vein occlusion by tumor compression and formed large hepatopetal collaterals via the gastric varices. The patient underwent tumor resection with splenectomy and, as a result, the gastric varices disappeared and the postoperative course was uneventful. Left-sided portal hypertension secondary to splenic vein occlusion is an uncommon complication mostly associated with pancreatitis and pancreatic carcinoma. Although benign pancreatic neoplasms only rarely cause such a condition, the possibility of gastrointestinal bleeding due to this condition should be carefully taken into consideration when treating pancreatic disease.

Effect of substrate on indirect immunofluorescence test for canine pemphigus foliaceus

The effect of substrate on indirect immunofluorescence (IIF) tests for the detection of circulating autoantibodies was studied by examining sera from 14 canine pemphigus foliaceus patients, six sera with non-pemphigus dermatoses and ten normal dog sera against five different substrates from three species. These substrates included bovine esophagus, bovine nose, bovine tongue, monkey esophagus, and canine nose skin. Nine out of 14 (64.3%) sera from patients with canine pemphigus foliaceus showed intercellular space staining by indirect immunofluorescence using bovine esophagus as substrate. However, sera from nonpemphigus dermatoses and normal dog did not react with bovine esophagus. In other substrates, only bovine tongue showed 1/8 (12.5%) positive reaction at the intercellular space by sera from canine pemphigus foliaceus. Dog nose skin showed the intercellular space staining against ten of ten (100%) normal dog serum. Monkey esophagus showed the fluorescent deposit at the intercellular space in four of nine (44.4%) of pemphigus foliacues dog sera, however, four of ten (40%) of normal dog sera revealed nonspecificity intercellular staining. These results indicate that the sensitivity and the specifity of IIF test in canine pemphigus foliaceus depend on the substrate. The best substrate for detecting circulating autoantibody in canine pemphigus foliaceus patients among five different substrates was bovine esophagus because of its sensitivity and high specificity. The diagnosis of canine pemphigus foliaceus should be made on the basis of a combination of clinical signs, histopathology, direct immunofluorescence, and the detection of circulating autoantibody.

Percutaneous hepatic venous isolation and extracorporeal charcoal hemoperfusion for high-dose intraarterial chemotherapy in patients with colorectal hepatic metastases

The results of treating 12 consecutive patients with unresectable colorectal hepatic metastases with a hepatic arterial infusion of high-dose Adriamycin, 100-120 mg/m2, using hepatic venous isolation (HVI) and charcoal hemoperfusion (CHP) are reported herein. Adriamycin was administered over 5-15 min under extracorporeal drug elimination by HVI-CHP. HVI was percutaneously accomplished by either the double-balloon technique using a Fogarty occlusion catheter (8/22F) or a balloon-tipped catheter (16F). During the infusion, isolated hepatic venous blood was filtered by CHP and pumped into the left axillary vein. There were no lethal complications, and good hemodynamic tolerance to HVI-CHP was confirmed. Tumor liquefaction accompanied by a sharp decrease in serum carcinoembryonic antigen levels by more than 50% of pretreatment levels was observed in 6 of the 12 patients 1 month after treatment. Apart from chemical hepatitis, which developed in 11 (92%) of the patients, the Adriamycin toxicities were well controlled following the development of nausea and vomiting in 2 patients (17%), leukopenia < 2,000/mm3 in 3 (25%), and gastric ulcer in 1 (8%). These results indicate that this method is a safe and useful procedure for otherwise hazardous high-dose intra-arterial chemotherapy in patients with unresectable hepatic tumors.

The role of guanine nucleotide binding proteins in hamsters with myocardial hypertrophy

To clarify the role of the guanine nucleotide binding proteins (G-proteins) in the pathogenesis of myocardial hypertrophy, we investigated the alterations in myocardial G proteins in 20-week-old F1b hamsters with pressure overload induced for 3 days (3-day AS), 7 days (7-day AS) and 14 days (14-day AS) by the stenosis of the abdominal aorta, and in 4- and 20 week-old BIO 14.6 Syrian hamsters (4-wk and 20-wk BIO) with genetic myocardial hypertrophy. The hearts of 7-day AS, 14-day AS and 20-wk BIO with left ventricular hypertrophy exhibited a decrease in the mRNA levels detected by Northern blot analysis and protein levels of G protein detected by Western blot analysis as compared with sham-operated and age-matched F1b hearts. The function of Gs or Gi showed a concomitant reduction in both models of myocardial hypertrophy. The hearts of 3-day AS and 4-wk BIO without myocardial hypertrophy showed no changes in G proteins as compared with sham-operated and age-matched F1b hearts. These results suggest that a decrease in G proteins is not involved in the pathogenesis of myocardial hypertrophy, but that myocardial hypertrophy reduced the G proteins.

Immunohistochemical demonstration of S-phase cells by anti-bromodeoxyuridine monoclonal antibody in cattle tissues

Bromodeoxyuridine (BrdU), a non-radioactive thymidine analogue, was administered to 15 cattle at a dosage of 1-10 mg/kg intravenously or intraperitoneally to demonstrate S-phase cells in the tissues. The organs and tissues were fixed in 10% neutral buffered formalin or in 70% ethanol, sectioned, denatured with hydrochloric acid, and treated with monoclonal antibody against BrdU. Immunohistochemical methods were used to "visualize" BrdU-labelled nuclei. BrdU-positive cells were satisfactorily demonstrated in both formalin- and ethanol-fixed tissues of animals given doses of 2 mg/kg or over, by either route of administration. Large numbers of BrdU-positive cells indicative of active cell production were found in the basal region of the stratified squamous epithelium, the neck between gastric pits and gastric glands in the abomasum, and the crypts of Lieberkühn of the small and large intestines. Moderate numbers of positive cells were observed amongst inflammatory cells in cases of nephritis and in granulation tissue. Numerous positive cells were detected in leukaemia cells. The study showed that BrdU can be used to measure proliferative S-phase cells in cattle, as in human beings, mice and rats.

Dual-tracer autoradiography with thallium-201 and iodine-125-metaiodobenzylguanidine in experimental myocardial infarction of rat

Dual-isotope scintigraphic studies with 201Tl and radioiodinated metaiodobenzylguanidine (MIBG) suggest that acute myocardial infarction causes extensive regional myocardial denervation beyond the infarcted area. We therefore investigated the histopathological and biochemical significance of the discrepancy between 201Tl and 125I-MIBG distribution determined by dual-tracer autoradiography in experimental myocardial infarction.

METHODS

Left coronary arteries of 12 male Wistar rats were ligated for 30 min followed by reperfusion. Dual-tracer autoradiography of infarcted heart sections was performed with 201Tl and [125I]MIBG 4 hr or 2 days after coronary reperfusion, followed by immunohistochemical staining with myoglobin monoclonal antibody to determine the area of myocardial infarction. Ultrastructural alterations and myocardial norepinephrine (NE) content in the region determined by dual-tracer autoradiography and myglobin immunostaining were studied.

RESULTS

Thirty-minute coronary ligation with 4-hr reperfusion produced myocardial infarction associated with discrepant region in the peri-infarcted myocardium characterized by decreased [125I]MIBG uptake and normal 201Tl distribution (discrepant region), as determined by dual-tracer autoradiography. In the discrepant region, which disappeared after 2 days, the nerve terminals showed loss of granular cores, with normal structures between normal myocytes. The mean myocardial NE level in the discrepant region was significantly lower than that in the nonischemic region (255.2 +/- 85.9 versus 549.5 +/- 82.5 ng/mg).

CONCLUSION

The uptake discrepancy of 201Tl and [125I]MIBG observed in the infarcted heart represents a transient functional denervation of the regional cardiac sympathetic nerve terminals in the noninfarcted myocardium.

Protective effect of teprenone on blood flow and incidence of histologic lesions in rat gastric mucosa after hemorrhage and retransfusion

BACKGROUND

The effects of teprenone (6,10,14,18-tetramethyl-5,9,13, 17-nonadecatetraen-2-one) on changes in gastric mucosal blood flow, adenosine triphosphate (ATP) content, and incidence of histologic lesions were evaluated in rat gastric mucosa after hemorrhage and retransfusion.

METHODS

Teprenone (100 mg/kg) was administered orally once a day for 3 consecutive days. On the 3rd day hemorrhage was induced, withdrawn blood (retransfusion) was returned, and the above variables were determined.

RESULTS

Teprenone significantly inhibited the decreases in blood flow and index of mucosal oxygen saturation (ISO2) during hemorrhage in the corpus and antral mucosa. However, no effect of teprenone was observed on systemic blood pressure and ATP levels after hemorrhage and retransfusion. Teprenone significantly (p < 0.05) decreased both the incidence of ischemic lesions and the increase in the severity of lesions after retransfusion in both mucosal regions.

CONCLUSION

From these results, it is concluded that the protective effect of teprenone on blood flow was partly responsible for its inhibitory effect on the incidence of lesions in the rat stomach in this hypovolemic shock model, although the former effect might be not a direct effect on systemic vascular tone.

Life span and tumours in the first-generation offspring of the gamma-irradiated male mouse

C57BL/6 male mice were exposed to 3 Gy 60Co gamma-rays and mated with unirradiated females after 15 days to produce F1 progeny produced following irradiation of the spermatids. After weaning the offsprings were allowed to live their normal life span. The mean litter size of the irradiated group significantly decreased from 7.1 to 4.9 (p < 0.01), but the sex ratio was not altered by the irradiation. No significant differences in the survival curve and mean life-span between the irradiated and control groups were noted. The only radiation effect in tumour incidence was a decrease of histiocytic sarcoma in female offspring of irradiated males. Except for this, there were no significant differences between the irradiated group and the control group in the incidence or age distribution of tumours.

rho-Mediated protein tyrosine phosphorylation in lysophosphatidic-acid-induced tumor-cell invasion

Rat ascites hepatoma cell (MM1) invade a mesothelial cell monolayer in vitro in assay medium containing serum, but not in serum-free medium. Serum could be completely replaced by 1-oleoyl lysophosphatidic acid (LPA) in inducing invasion. LPA-induced invasion was inhibited by genistein, a tyrosine-kinase inhibitor. Protein tyrosine phosphorylation in response to LPA was thus analyzed in order to determine the molecular mechanism of invasion. LPA of invasion-inducible concentrations evoked a transient increase in tyrosine phosphorylation, mainly of 110- to 130-kDa proteins in MM1 cells but not in mesothelial cells. These concentrations of LPA were over 10 times higher (10 to 25 micron) than those necessary to produce a variety of biological actions, such as tyrosine phosphorylation in fibroblasts, neurite retraction and platelet aggregation. Protein tyrosine phosphorylation and invasion by MM1 cells induced by LPA are largely regulated by rho p21, because both were inhibited by Clostridium botulinum C3 exo-enzyme, which is known to specifically inactivate rho p21. Invasion of MCL by MM1 cells induced by serum and that by B16FE7 cells induced by LPA were inhibited by genistein or C3 as well. By immunoprecipitation, we detected p 125 focal adhesion kinase (FAK) as a major protein of 110- to 130-kDa tyrosine phosphorylated in response to LPA. Tyrosine phosphorylation of paxillin by LPA was also detected.

Comparative accuracy of various Tl-201 reinjection imaging protocols to detect myocardial viability

The conventional exercise-3 hours-redistribution thallium-201 [201Tl] imaging protocol has been recognized to be suboptimal for reliable detection of myocardial viability. Although 201Tl rest-injection after exercise has improved detection of viable myocardium, it is still underestimated in some patients. The present study was designed to compare detection of viable myocardium in five separate imaging steps: step 1: initial-exercise imaging, step 2: delayed-exercise imaging, step 3: Tl-201 reinjection imaging after delayed-exercise imaging, step 4: separate day rest-injection imaging, and step 5: separate day delayed-rest imaging. The study group consisted of 22 patients scheduled for coronary revascularization (either percutaneous transluminal coronary angioplasty or coronary bypass surgery). Pre- and postintervention echocardiographic wall motion and thickness served as independent markers of myocardial viability.

RESULTS

Accuracy in identifying myocardial viability gradually improved incrementally from 201Tl imaging step 1 to step 5. The positive predictive value, negative predictive value and overall accuracy were best for the separate day delayed-rest study (step 5) at 90%, 33% and 78%, respectively. Myocardial segments had fixed defects on separate day delayed-rest 201Tl imaging (step 5), but nevertheless echocardiographic evidence of myocardial viability indicated less severe defects than segments judged nonviable by echocardiography (p = 0.021). The overall accuracy of separate day delayed-rest imaging (step 5) in predicting viability improved to 88% when segments with moderate or mild defects were considered viable. In conclusion, the most reliable predictor of myocardial viability with 201Tl imaging is defect severity on separate day delayed-rest images.

Ethanol-induced state-dependent learning is mediated by 5-hydroxytryptamine3 receptors but not by N-methyl-D-aspartate receptor complex

Involvement of N-methyl-D-aspartate (NMDA) receptor complex and 5-hydroxytryptamine3 (5-HT3) receptors in state-dependent learning (SDL) induced by ethanol (EtOH) was investigated in the step-through passive avoidance task in rats. Pre-training injections of EtOH or MK-801 reduced step-through latency in the test session conducted 24 h after the training session. Pre-test as well as pre-training injections of EtOH failed to reduce the latency, while pre-training and pre-test injections of MK-801 reduced the latency. These results show that EtOH but not MK-801 produces SDL. SDL induced by EtOH was blocked by ICS205-930 injected before either the training or test session. However, ICS205-930 failed to block SDL induced by diazepam and muscimol. These results suggest that NMDA receptor complex may not be involved in SDL, and that 5-HT3 receptors may contribute to SDL induced by EtOH but not by diazepam and muscimol.

Active and passive avoidance learning in rats neonatally treated with intraventricular 6-hydroxydopamine

To clarify the behavioral characteristics of rats neonatally treated with 6-hydroxydopamine (6-OHDA), their performance on 4 aversive learning tasks, 3 active (shuttle, one-way, and rearing) avoidance tasks and one passive (step-through) avoidance task, was examined. On days 2 and 4 after birth, each rat of F344/Du strain received bilateral intraventricular injections of 6-OHDA (35 micrograms x 2) or vehicle solution following desmethylimipramine (20 mg/kg, s.c.) pretreatment. From day 90, each rat was trained in one of the 4 avoidance tasks. 6-OHDA-treated rats showed significantly less avoidance responses in the shuttle and the one-way avoidance tasks, but their performance on the rearing and the step-through passive avoidance tasks was not significantly different from that of control rats. The differential impairment of avoidance suggests that 6-OHDA treatment does not cause a general learning deficit, but facilitates rearing and/or jumping responses in aversive situations, which results in inappropriate escape responses.