Transient left ventricular dysfunction in ischaemic myocardium after stress: comparative study with exercise and pharmacological stress gated myocardial single photon emission computed tomography

In ischaemic heart disease patients, transient left ventricular dysfunction is observed due to post-exercise stunning. The aim of this study was to determine whether transient left ventricular dysfunction could also be seen after short-acting pharmacological stress (adenosine triphosphate). A 1 day rest/stress gated myocardial single photon emission computed tomography was performed on 362 patients suspected of having ischaemic heart disease by exercise (n=199) or short-acting pharmacological stress (n=163). Left ventricular ejection fraction were estimated both at rest and stress. Based on perfusion findings, patients were subdivided into ischaemia, fixed defect and normal group. For the ischaemia and fixed defect group, left ventricular ejection fraction after stress was significantly decreased compared with the resting value by exercise stress (ischaemia group, 57.5+/-11.0 vs 60.4+/-10.4; fixed defect group, 47.7+/-16.7 vs 49.6+/-16.8; P<0.01), but not by pharmacological stress (ischaemia group, 55.8+/-13.4 vs 57.1+/-13.8; fixed defect group, 50.8+/-13.5 vs 50.6+/-13.1; P=NS). In the normal group, left ventricular ejection fraction after stress was not significantly changed by either exercise (65.7+/-10.4 vs 66.8+/-10.2; P=NS) or pharmacological stress (63.0+/-11.7 vs 64.0+/-12.1; P=NS). It is concluded that a transient decrease in left ventricular ejection fraction after stress was observed following post-exercise, not following a short-acting pharmacological stress in patients showing perfusion abnormalities. Transient left ventricular dysfunction may be the result of post-exercise stunning, not from subendocardial hypoperfusion induced by short-acting pharmacological stress.

Inhibitory effect of Y-27632, a ROCK inhibitor, on progression of rat liver fibrosis in association with inactivation of hepatic stellate cells

BACKGROUND/AIMS

Activation of hepatic stellate cells (HSCs) is a final common pathway of liver fibrosis. Recently, it has been demonstrated that the small GTPase Rho is involved in HSCs activation, and that Y-27632, an inhibitor of Rho-kinase which is an effector that acts downstream of Rho, inhibits Rho-associated effects. The objective of the current study was to investigate the inhibitory effects of Y-27632 on the activation of HSCs and the progression of liver fibrosis.

METHODS

Y-27632 (1, 10, 100 microM) was added to HSCs isolated from normal rat liver.

RESULTS

HSCs maintained the 'star-like' configuration of the quiescent stage in the presence of Y-27632, as well as inhibition of the expression of Na+/Ca2+ exchanger mRNA which was reported to be an indicator of HSCs activation. In addition, when Y-27632 (30 mg/kg body weight) was administered to rats with carbon tetrachloride-induced liver fibrosis, collagen deposition was inhibited, the hepatic hydroxyproline content was decreased, and the serum hyaluronic acid level was reduced. Moreover, Y-27632 reduced the number of smooth muscle alpha-actin-positive cells and transforming growth factor-beta1-positive cells, and inhibited the expression of Na/Ca2+ exchanger mRNA.

CONCLUSIONS

These findings indicate that Y-27632 may be useful for the clinical management of liver fibrosis.

Stereocontrolled synthesis of the northern part of potent proteasome inhibitor TMC-95A

[reaction: see text]. A protected version of the northern part of TMC-95A, a potent and selective proteasome inhibitor, was synthesized with full stereochemical control. Highlights of this synthesis include (i) a (Z)-selective Mizoroki-Heck reaction to construct the oxyindole portion, (ii) a diastereoselective epoxidation, (iii) a 6-endo selective epoxide opening by Boc carbonyl group to establish the stereochemistry of C6, and (iv) a 1,3-elimination reaction of the L-allo-threonine derivative under Mitsunobu conditions to afford the (Z)-1-propenylamine.

RECK gene expression in hepatocellular carcinoma: correlation with invasion-related clinicopathological factors and its clinical significance. Reverse-inducing--cysteine-rich protein with Kazal motifs

The RECK (reversion-inducing-cysteine-rich protein with Kazal motifs) gene was initially isolated as a transformation suppressor gene. It encodes a membrane-anchored glycoprotein with multiple serine protease inhibitor-like domains. The RECK gene is expressed widely in normal organs but is undetectable in many tumor-derived cell lines. When artificially expressed in such cell lines, RECK suppresses their invasive and metastatic activities. Clinical implications of these findings, however, remained undefined because of the lack of studies using fresh human tumor samples. In the present study, we have addressed this issue by analyzing the levels of RECK gene expression in hepatocellular carcinoma (HCC). RECK mRNA was detectable by RNA blot hybridization in all the tumorous and contiguous nontumorous tissues obtained from 64 patients with HCC. In 26 cases, the RECK expression in tumorous tissues was higher than that in nontumorous tissues. The expression of RECK protein in these tissues could also be demonstrated by immunohistochemistry. Patients with high RECK mRNA expression in tumorous tissues tended to show better survival (P =.02), and such tumors had a tendency to be less invasive. Univariate and multivariate analysis revealed that the RECK mRNA expression is a novel and independent variable affecting overall survival (P =.01). These findings support the hypothesis that RECK has negative effects on the invasiveness of HCC cells and suggest the feasibility of RECK mRNA as a promising prognostic molecular marker for HCC.

Role of E-cadherin in peritoneal dissemination of the pancreatic cancer cell line, panc-1, through regulation of cell to cell contact

The present study was designed to clarify the molecules responsible for peritoneal dissemination of cancer cells. We established sublines with high (HP cells) and low (LP cells) passing activity through the membrane of a transwell chamber. The cell lines were established from the human pancreatic cancer cell line, Panc-1. LP cells demonstrated an octagonal shape and tight adhesion, whereas HP cells exhibited a spindle shape and grew with less cell-cell contact in vitro. It was found that HP cells demonstrated a high degree of peritoneal dissemination in nude mice following peritoneal injection of these cells compared to LP cells. We subsequently investigated the expression of certain adhesion molecules. Consequently, we found that LP cells exhibited a stronger expression of E-cadherin than HP cells. On the other hand, there was no difference in the expression of CD44H and beta1 integrin between these two sublines. Passing activity of LP cells through the membrane of the invasion chamber increased to nearly equal levels with HP cells following treatment with anti-human E-cadherin antibody. Moreover, transfection of mouse E-cadherin cDNA into HP cells reduced both passing activity through the membrane of the invasion chamber and peritoneal dissemination in nude mice to levels similar to that of LP cells. In conclusion, these results indicated that loss of E-cadherin facilitates both passing activity in an invasion chamber and peritoneal dissemination, playing a causative role in peritoneal dissemination of cancer cells.

Soluble Flt-1 gene therapy for peritoneal metastases using HVJ-cationic liposomes

Many studies have reported a close association between VEGF and tumor angiogenesis. The aim of the present study was to evaluate the effectiveness of gene therapy against cancer, including peritoneal metastasis, using a cDNA encoding a soluble type of Flt-1, one of the VEGF receptors. In a peritoneal metastasis model of MKN45 human gastric cancer cells, mice repetitively treated with intraperitoneal injections of HVJ-Fex, a type of HVJ-cationic liposome encapsulating a plasmid expressing soluble mFlt-1, exhibited smaller disseminated foci with fewer microvessels, thus resulting in a significantly longer survival period than the control mice. In another peritoneal metastasis model using HT1080S cells, a clone of HT1080 human fibrosarcoma cells stably transfected with hVEGF, treatments with HVJ-Fex also reduced the growth of disseminated foci without ascites formation. In conclusion, this study demonstrated that the peritoneal metastases of some cancers were largely dependent on VEGF, and that the repeated intraperitoneal transduction of a soluble flt-1 gene using HVJ-cationic liposomes suppressed peritoneal metastases, thereby contributing to a longer survival period.

Mouse macrophage metalloelastase gene transfer into a murine melanoma suppresses primary tumor growth by halting angiogenesis

Mouse macrophage metalloelastase (MME) has been associated with the generation of angiostatin, an internal fragment of plasminogen, which inhibits angiogenesis. To clarify whether tumor cells that consistently generate MME can suppress angiogenesis and, therefore, inhibit the growth of primary tumors in vivo, we transfected a cDNA coding for MME into murine B16-BL6 melanoma cells that grow rapidly and are MME deficient. The generation of active MME in MME-transfected clones was confirmed by immunoprecipitation followed by in vitro cleavage of plasminogen. Subcutaneous implantation of these stable clones in C57BL/6 mice inhibited primary tumor growth by an average of 73% (P = 0.00002), which directly correlated with a significant reduction of blood vessel formation (approximately 76%) in such tumors. Microangiography revealed massive angiogenesis in control tumors (mock and vector); however, in MME-transfected primary tumors it demonstrated a decreased and disrupted vascular network. Western blot analysis using a specific anti-mouse angiostatin antibody demonstrated a strong 38-kDa immunoreactive band in MME-transfected tumors and in the serum of mice bearing those tumor cells. These results show that placing MME gene directly into B16-BL6 melanoma cells is an effective approach to suppress primary tumor growth in vivo because it halts angiogenesis. Our data provide a feasible and promising strategy for gene therapy of cancer by targeting tumor vasculature.

Protection by vascular endothelial growth factor against sinusoidal endothelial damage and apoptosis induced by cold preservation

BACKGROUND

It is well known that sinusoidal endothelial cell (SEC) damage during cold preservation of liver tissue is closely involved in early graft failure. The objective of this study was to investigate the involvement of apoptosis in the SEC damage induced by cold preservation and to demonstrate the protective effect of vascular endothelial growth factor (VEGF) on SEC injury, including apoptotic changes.

METHODS

Isolated SECs and liver tissue of Wistar rats were cold-preserved in University of Wisconsin (UW) solution, and the protective effect of VEGF was then investigated. Isolated SECs were cultured for 24 hr, and divided into the following 3 groups: Group A, in which the cells were cultured for an additional 27 hr, Group B, in which the cells were cold-preserved in UW solution for 3 hr, and then recultured for 24 hr, and Group C, in which 20 ng/ml of VEGF was added to both the culture medium and the UW solution of cells cultured according to the Group B protocol. Each group of SECs was morphologically examined using the phase contrast microscopic method and the transmission electron microscopic method (TEM), and quantitatively analyzed using the WST-1 assay. Rat livers were cold-preserved in UW solution and divided into the VEGF(+) group and the VEGF(-) group, depending on whether VEGF was added or not. Each group of livers were analyzed by scanning electron microscopic method (SEM) after 24 hr of preservation. The hyaluronic acid uptake rate (HUR) was also determined after 6 hr of preservation. After 24 hr of preservation and 6 hr of reperfusion, tissues were examined by TEM and by the terminal deoxynucleotidyl transferase d-uridine triphosphate nick end labeling (TUNEL) assay.

RESULTS

The phase contrast microscopic method and the WST-1 assay showed a protective effect of VEGF against the injury to isolated SECs during cold preservation and subsequent reculturing. Apoptosis was detected immediately by TEM after isolation of SECs, and the number of apoptotic cells increased with the incubation time. This increase was accelerated after cold preservation. The scanning electron microscopic method and the hyaluronic acid uptake rate showed a protective effect of VEGF against SEC damage in the cold-preserved livers. In the liver tissue, the TEM and the TUNEL assay detected apoptosis of SECs only after cold preservation and subsequent reperfusion. VEGF suppressed the apoptosis of SECs induced by cold preservation in both isolated cells and liver tissue.

CONCLUSIONS

We demonstrated that SEC damage in the cold preservation of liver tissue was caused mainly by apoptosis, which required subsequent reperfusion. Moreover, isolated SECs showed spontaneous occurrence of apoptotic changes during culture, and these changes were accelerated by the preceding cold preservation. This is the first report to demonstrate the apoptotic changes of SECs seen here were inhibited by VEGF.

Pretreatment with soluble thrombomodulin prevents intrasinusoidal coagulation and liver dysfunction following extensive hepatectomy in cirrhotic rats

The major cause of posthepatectomy liver dysfunction is supposed to be microcirculatory disturbance caused by imbalance of intrasinusoidal coagulation equilibrium. Thrombomodulin (TM) is a potent anticoagulant expressed on the endothelial cell surface that regulates the coagulation system by binding thrombin and accelerating the thrombin-catalyzed activation of protein C. Therefore, we examined the effect of soluble TM purified from human urine (UTM) on intrasinusoidal coagulation in cirrhotic rats. Dimethylnitrosamine-induced cirrhotic rats underwent 70% hepatectomy and received endotoxin 48 h after. UTM or vehicle alone was intravenously administered to each rat 30 min before endotoxin injection. UTM treatment attenuated the increases in cytosolic enzymes and serum hyaluronic acid level. The UTM supply improved the survival rate of the rats at 12 h after endotoxin challenge. Histologically, intrasinusoidal fibrin depositions and massive hepatocellular necrosis observed in control rats were scarcely found in UTM-treated rats. Immunohistochemical examination revealed that marked TM stains in sinusoidal endothelial cells were well preserved in UTM-treated rats. In conclusion, UTM administration prevented intrasinusoidal fibrin depositions and attenuated posthepatectomy liver dysfunction in cirrhotic rats.

Protective effects of prophylaxis with a protease inhibitor and a free radical scavenger against a temporary ischemia model of pancreatitis

OBJECTIVE

To evaluate the protective effects of combined prophylaxis with 4-sulfamoylphenyl, 4-guanidinobenzoate methanesulfonate (E3123), potent new protease inhibitor, and superoxide dismutase (SOD), a free radical scavenger, against the multifactor-related pancreatic injuries that occur in acute pancreatitis.

DESIGN

Controlled experimental study in rats with pancreatitis induced by a temporary ischemic model of pancreaticobiliary-duct (PBD) obstruction.

SETTING

A university-affiliated hospital.

EXPERIMENTAL SUBJECTS

Seventy-eight male Wistar rats, weighing approximately 300 g each.

INTERVENTIONS

In 18 rats the PBD was occluded with a metal clip, and cerulein was infused for 30 minutes at an hourly rate of 0.2 microgram/kg. After 1 hour the metal clip was removed and the abdomen closed (PBD obstruction group). In 21 rats the same protocol was followed, but ischemia was induced by occlusion of celiac and caudate mesenteric arteries for 30 minutes (ischemia group). In 24 rats the same protocol was followed as for the ischemia group, but 1 hour before and throughout the experiment, E3123 was infused at an hourly rate of 5 mg/kg, and before occlusion of the PBD and immediately after release of the occlusions of the PBD and arteries, SOD, 1 mg/kg, was injected intravenously (treatment group). Fifteen rats underwent laparotomy and gentle manipulation of the pancreatobiliary duct and celiac and caudate mesenteric arteries only (control group).

MAIN OUTCOME MEASURES

Serum amylase levels and pancreatic water and amylase levels, histologic changes in pancreas, subcellular amylase and cathepsin-B activities and in-vivo amylase and cathepsin-B outputs.

RESULTS

Serum amylase levels and pancreatic water and amylase content were significantly (p < 0.05) reduced in the treatment group (mean [+/- standard error] 13 [2] U/mL, 77 [2] % of wet weight and 503 [56] U/mg of DNA respectively) compared with the ischemia group (25 [3] U/mL, 83 [2] % of wet weight and 731 [52] U/mg of DNA respectively). PBD obstruction and ischemia also caused a significant (p < 0.05) subcellular redistribution of cathepsin B from the lysosomal to the zymogen fraction and impaired output of amylase and cathepsin B into pancreatic juice, which was compensated for in the treatment group.

CONCLUSIONS

Temporary pancreatic ischemia and oxygen-derived free radicals appear to play an important role in the pathogenesis of acute pancreatitis. E3123 and SOD may be useful in the prophylaxis of clinical pancreatitis.

Effect of administration of serum thymic factor (FTS) in calves and rabbits infected with bovine immunodeficiency-like virus

The effect of serum thymic factor (FTS) administration in bovine immunodeficiency-like virus (BIV)-infected calves and rabbits was examined. We previously found that some of the macrophage functions were depressed and humoral immune responses against foreign proteins were delayed in BIV-infected calves compared to uninfected calves. After FTS administration, however, no delay of antibody responses against foreign proteins was observed in BIV-infected calves. Though the chemiluminescence (CL) responses of macrophages in BIV-infected calves were significantly depressed (p < 0.05), FTS administration resulted in the recovery of the CL responses in the BIV-infected calves comparable to those in the control calves. Antibody responses against foreign proteins in BIV-infected rabbits were significantly depressed (p < 0.025) as compared with those in uninfected rabbits, though the depression became no significant after FTS administration.

[Posterior proctomucosectomy and ileal pull-through reconstruction: a new restorative procedure after total proctocolectomy]

We reported a new method of restorative proctocolectomy using posterior approach and pull-through reconstruction. This method obviated transanal manipulation, a major factor causing damage to the internal sphincter, thus preventing fecal incontinence due to sphincter dysfunction. Also, temporary ileostomy was not necessary because the spout of an S-pouch was pulled down below the anal verge and its distal free end acted as a diverting stoma while the more proximal, healing zone (future anastomotic line) was kept from fecal contamination. This method was applied to a 32-year-old woman with familial polyposis coli and a 50-year-old woman with ulcerative colitis. Their bowel movements steadily decreased to three times and five times a day, respectively. There was no fecal leakage or perianal excoriation. The advantages as well as disadvantages of this method compared with the conventional techniques were discussed.

[Huge leiomyosarcoma of the mesentery: a case report]

A patient, a 63 year-old-man, was admitted suffering from discomfort in the left abdominal area; this proved to be a case of leiomyosarcoma of the mesentery. An upper gastrointestinal series revealed stenosis in the 3rd portion of the duodenum, and shift of the entire intestine to the right side. Computed tomography showed a giant mass lesion with a central necrosis. Selective arterial angiography showed a heterogeneous tumor stain with several feeders and drainage veins. A partial resection of the intestine around the Treitz's ligament and left hemicolectomy was required due to the tumor's invasion of the intestinal wall and transverse colon. The operation was successfully performed supported by the angiographic findings. The resected tumor was 23 cm in diameter, 2330 g in weight, and was filled with blood. The histological diagnosis was leiomyosarcoma of the mesentery. The patient has been doing well during the 6 months postoperative period.

DNA sequencing directly from a mixture using terminal-base-selective primers

DNA cloning is often used to select and amplify one DNA species from a mixture. However, the cloning process is complex and labor-intensive. We have developed a new two-step method for DNA sequencing directly from a mixture. The first is the introduction of a known oligonucleotide (common part) into the terminus of unknown DNA by ligation. The second is selective DNA sequencing using primers with two additional nucleotides at the 3' terminus in addition to the common part (terminal-base-selective primers). The primers work only for templates on which the primers perfectly hybridized. This method was found to be effective for the HindIII digestion products of lambda phage.

Infection and dysfunction of monocytes induced by experimental inoculation of calves with bovine immunodeficiency-like virus

Three calves were experimentally inoculated with bovine immunodeficiency-like virus (BIV) to examine BIV pathogenesis. Inoculated calves produced specific antibody that could be detected from 3 to 5 weeks up to 1 year postinoculation (pi). Virus was isolated from peripheral blood mononuclear cells (PBMC) 3-4 weeks pi by syncytia assay. Thereafter, the virus could be continually isolated. BIV could be isolated from monocytes but not from T cells. Likewise, monocytes could be infected with BIV in vitro. Various monocyte functions of these BIV-infected calves and age-matched uninfected calves were tested; superoxide anion release, phagocytic activity, and chemotactic responsiveness of monocytes were depressed in BIV-infected calves compared with control calves. A slight delay in the humoral immune response against mouse serum protein was also evident. During the observation period of approximately 1 year, no significant clinical symptoms could be observed. One calf, however, was killed at 15 months pi. At the time of necropsy, BIV could be isolated from PBMC as well as from cells of the spleen, liver, and lymph nodes.