PubMed Health⌕ Search

Biomedical subjects

M Hashizume

Publications and source records attributed to M Hashizume.

At least 55 records · Page 3Linked to original sources
PubMed2000

Laparoscopic hepatectomy: new approach for hepatocellular carcinoma.

This article presents the rationale for the laparoscopic approach to liver surgery, showing the technique of fully endoscopic and endoscopic-assisted formal and wedge hepatic resections. The early results are comparable to those of conventional surgery, with the benefits derived from minimal access surgery. Laparoscopic liver resections are technically feasible, with an acceptable morbidity and mortality rate, but extensive experience in conventional liver surgery, advanced laparoscopic surgery, and the availability of all requested technologies are indispensable prerequisites.

Carcinoma, Hepatocellular↗
PubMed2000

Effectiveness of gastric devascularization and splenectomy for patients with gastric varices.

BACKGROUND: Bleeding from gastric varices is difficult to control and has a high mortality rate. Recently, newly developed treatments for this serious lesion have been used, but surgical intervention is still advocated by several studies. We report our experience with gastric devascularization and splenectomy and its effectiveness for patients with gastric varices. STUDY DESIGN: Gastric devascularization and splenectomy was successfully performed to treat patients with isolated gastric varices (n = 42). The patients included 27 men and 15 women who ranged from 29 to 73 years of age (average 53.7 years). We analyzed the findings of gastric varices using endoscopy, the results of gastric devascularization and splenectomy, and survival after the operation. RESULTS: No patient had tortuous varices (F1). Twenty-seven patients (64.3%) had nodular varices (F2) and 15 (35.7%) had tumorous varices (F3). Twenty-five patients (59.5%) had large varices that occupied two or more areas. Twenty-nine patients (69.0%) had varices with a positive red color sign. No major complications during or after the operation were observed, and peri-operative death did not occur. Gastric varices were eradicated in all 42 patients. Survival rates were 97.6% after 1 year, 88.1% after 3 years, 76.2% after 5 years (mean followup period, 46 months). CONCLUSIONS: This study showed that gastric devascularization and splenectomy provides satisfactory results for patients with gastric varices that are likely to bleed and that it can be performed even on patients who have had other treatments.

Adult↗
PubMed2000

Role of endothelin-1 in congestive gastropathy in portal hypertensive rats.

BACKGROUND: The aim of this study was to determine the role of endothelin (ET)-1 in portal hypertensive gastropathy (PHG) under portal hypertension, in order to investigate whether the ET(A/B) receptor inhibitor improves the permeability of gastric mucosal microvessels in PHG. METHODS AND RESULTS: Portal hypertensive rats (PVL) and sham-operated rats (CTR) were prepared and then the concentration of plasma ET-1 was measured and the vasopressor response to ET-1 was compared between the two groups. The plasma ET-1 levels in PVL increased significantly compared with CTR; however, the vasopressor response to ET-1 in PVL decreased more than in CTR. Next, the portal venous pressure was measured in both CTR and PVL pretreated with or without a nitric oxide (NO) synthase inhibitor, N(G)-nitro-L-arginine methyl ester (L-NAME), before the injection of ET-1. The portal venous pressure of PVL after receiving ET-1 and being pretreated with L-NAME significantly increased in comparison to the pressure of PVL treated with ET-1 alone (without L-NAME). Moreover, Evans-Blue was injected into each rat and the absorbancy of the gastric contents was measured. The absorbancy of Evans-Blue in PVL increased significantly compared with CTR; however, the absorbancy in PVL+ ET(A/B) receptor inhibitor (Ro47-0203) decreased significantly more than in PVL. CONCLUSIONS: This study showed that ET-1 is a potent vasoconstrictive substance that also has a transitory vasodilative response through NO induced by ET-1 in portal hypertension. In addition, it was found that the vascular permeability of the gastric mucosa increased in portal hypertension and that Ro47-0203 inhibited the hyper-permeability. Accordingly, ET-1 may, thus, play an important role in the development of PHG through NO induced by ET-1. Ro47-0203 may, therefore, be a useful substance for improving PHG in portal hypertension.

Animals↗
PubMed2000

Role of nitric oxide and endothelin-1 in a portal hypertensive rat model.

BACKGROUND: Portal hypertension is often accompanied by a hyperdynamic circulation state. Some reports have suggested that nitric oxide (NO) plays an important role in this hyperdynamic state. On the other hand, although endothelin (ET)-1, a powerful vasoconstrictor, was recently identified, little is known about its role in portal hypertension or about the interaction between NO and ET-1. The aim of this study was therefore to investigate whether or not the inhibitor of NO synthase (NOS) might improve portal hypertension, and also to clarify the relationship between NO and ET-1. METHODS: Portal hypertensive (PHT) rats, in which hypertension was induced by a two-step ligation of the portal vein (PVL), were used. The mean arterial pressure (MAP), portal pressure (PP), visceral blood flow volume (BFV), and serum levels of NO and ET-1 were determined in PVL rats treated with two NOS inhibitors with different functions: N(G)-nitro-L-arginine methyl ester (L-NAME) and aminoguanidine (AG). Control (CTR) rats. treated by a sham operation (SO), were also studied. RESULTS: Two-step PVL treatment induced a significant increase in the serum level of NO3-and ET-1 in the portal vein. L-NAME and AG administration significantly decreased PP at doses of 50 mg/kg in PHT rats after 60 min administration, while no inhibitor effected any modification in the CTBR rats. Both NOS inhibitors increased MAP and decreased PP and BFV in the portal vein, gastric mucosa, and spleen, in addition to decreasing the serum levels of NO3- and ET-1 in the PHT rats, while neither blockade modified any parameters in the CTR rats. In PHT rats, L-arginine, a NO substance, reversed the effect of L-NAME, while it did not induce any recovery from the AG effect. CONCLUSIONS: In PHT rats, NO seems to contribute to portal hypertension. PVL increases not only the serum level of NO3-, but also that of ET-1 in the portal vein. Both L-NAME and AG reduce PP and BFV of the portal vein, spleen, gastric mucosa. and liver. In addition, the inhibition of NOS diminishes the serum level not only of NO, but also of ET-1. Use of an appropriate NOS inhibitor may therefore positively affect the hyperdynamic state in portal hypertension.

Animals↗
PubMed2000

Endoscopic ligation of oesophageal varices compared with injection sclerotherapy in primary biliary cirrhosis.

BACKGROUND AND AIMS: Oesophageal varices are an important complication in primary biliary cirrhosis (PBC). However, there have yet to be any studies made on treatment of oesophageal varices in PBC. We therefore studied the efficacy and related complications of endoscopic variceal ligation (EVL) and endoscopic injection sclerotherapy (EIS) as an initial treatment in primary biliary cirrhotic patients. METHODS: From December 1985 to March 1999, 29 biliary cirrhotic Japanese patients with portal hypertension and oesophageal varices were treated in our clinics. Eleven patients were treated with EVL and EIS, and 18 patients underwent EIS only. The liver function, renal function and respiratory function were studied before and after endoscopic treatment and any complications were also examined. RESULTS: In stages III and IV, significant differences were observed in the serum levels for total bilirubin and gamma-glutamic pyruvic transaminase only in the EIS group. Significant differences were observed in the rate of appearance of pyrexia, retrosternal pain and pleural effusion between the EIS and EVL groups. CONCLUSION: EVL significantly reduced the adverse effects associated with EIS at the initial session in primary biliary cirrhotic patients.

Esophageal and Gastric Varices↗
PubMed2000

Role of vascular endothelial growth factor in portal hypertensive gastropathy.

BACKGROUND AND AIMS: Portal hypertensive gastropathy (PHG) is now recognized as a distinct entity; however, the angiogenesis in the portal hypertensive gastric mucosa has yet to be elucidated. Vascular endothelial growth factor (VEGF) is a potent angiogenic factor involved in both physiological and pathological angiogenesis. The aim of this study was thus to examine the function of VEGF in the portal hypertensive and non-portal hypertensive gastric mucosa. METHOD: Forty-five cirrhotic patients were divided into 3 groups as follows. Group I included 15 patients without PHG who were treated with 1.5 g teprenone/day for 8 weeks: PHG(-)-t. Group II included 15 patients with PHG who were not treated with teprenone: PHG(+)-n. Group III included 15 patients with PHG who were treated with teprenone for 8 weeks: PGH(+)-t. The gastric mucosal blood flow (GMBF), the concentration of gastric mucosal VEGF and hexosamine and the endoscopic findings were studied both before and after medication. RESULTS: Before teprenone treatment, the GMBF in the antrum, fundus, fornix were significantly higher in PHG(+)-n than PHG(-)-t. After treatment, the GMBF in the fundus and fornix significantly decreased more than before treatment in the PHG(+)-t. After treatment, the GMBF in the antrum increased significantly more than before treatment in PHG(-)-t. The gastric VEGF and hexoxamine concentration in the antrum were significantly higher in PHG(+)-n than in PHG(-)-t. After treatment, the gastric VEGF and hexosamine concentration in the antrum significantly decreased in PHG(+)-t while no change in concentration was recognized in PHG(+)-n. In the endoscopic findings, a decrease in the PHG score was recognized in 2 patients in PHG(+)-t. CONCLUSION: Portal hypertensive gastric mucosal change was thus found to trigger a high concentration of VEGF and hexosamine. Such increased activity of VEGF and hexosamine may thus account for the presence of active congestion in PHG.

Adult↗
PubMed1999

Leiomyosarcoma of the thyroid gland with rapid growth and tracheal obstruction: A partial thyroidectomy and tracheostomy using an ultrasonically activated scalpel can be safely performed with less bleeding.

Primary leiomyosarcoma of the thyroid gland is rare, and to the best of our knowledge only nine well-documented cases have been previously reported in the world literature. We herein report a 90-year-old female patient with primary leiomyosarcoma of the thyroid gland who showed a rapid tumor growth and tracheal obstruction. The patient was successfully treated by a partial resection of the thyroid gland using an ultrasonically activated scalpel and emergency tracheostomy. Immunohistochemically, the tumor cells showed positive reactivity to smooth muscle actin and negative reactivity to thyroglobin. Palliative surgery successfully allowed the patient to recover from the symptoms of dyspnea related to this rare disease. The use of an ultrasonically activated scalpel and tracheostomy thus allowed us to safely perform a thyroidectomy with substantially less bleeding than normal.

Aged↗
PubMed1999

The author replies

Explore the source record for details and available documents.

Journal Article↗
PubMed1999

Results of laparoscopic splenectomy for immune thrombocytopenic purpura.

BACKGROUND: Laparoscopic splenectomy has been demonstrated to be technically feasible and safe for the treatment of immune thrombocytopenic purpura (ITP), hereditary spherocytosis, and Hodgkin's disease. PATIENTS AND METHODS: The study comprised 76 consecutive patients with chronic ITP who were admitted to our hospital from 1968 to 1997 and underwent splenectomy; 35 patients underwent a laparoscopic splenectomy, and 41 had open surgery. RESULTS: Laparoscopic splenectomy involved minimal incision, and a significantly lower frequency of analgesia was required for postoperative abdominal pain (1.4 versus 3.3); postoperative hospital stay was shorter (9.6 versus 20.1 days, P <0.05). Operative time was significantly longer for the laparoscopic surgery (204.5 versus 99.8 minutes, P <0.01), but blood loss was less (154.4 versus 511.7 g, P <0.01). During the present study (range 3.8 to 80 months), accumulative nonrecurrence rate was 67.9% in 5 years after surgery, which is similar to that of the previous open splenectomy. CONCLUSIONS: Laparoscopic splenectomy can become an alternative therapeutic modality in the treatment of ITP.

Adult↗
PubMed1999

A selective cyclo-oxygenase-2 inhibitor, NS-398, may improve portal hypertension without inducing gastric mucosal injury.

BACKGROUND AND AIMS: Prostacyclin has been shown to play a role in hyperdynamic circulation in portal hypertension. Recently, a new subtype of cyclo-oxygenase (COX), COX-2, which acts as an inducible synthase in response to various stimuli. The aim of this study was to investigate whether COX-2 contributes to portal hypertension and whether a COX-2 blockade induces the same sort of gastric mucosal injury as a COX-1 blockade. METHODS: Portal hypertension (PHT) in rats was induced by a two-step ligation of the portal vein. The mean arterial pressure (MAP), portal pressure (PP), visceral blood flow volume (BFV), serum levels of 6-keto-prostaglandin F1alpha (PGF1alpha), thromboxane B2 (TXB2) and gastric mucosal injury induced by pure ethanol were all measured in PHT rats receiving different inhibitors (indomethacin, a highly selective COX-1 inhibitor; NS-398, a highly selective COX-2 inhibitor). Control rats treated by a sham operation were also studied. RESULTS: The NS-398 administration significantly decreased PP to the same extent as indomethacin at doses of 5 and 10 mg/kg in PHT rats after a 60 min administration, while neither inhibitor affected the control rats. Both inhibitors significantly increased PP after a 30 min administration in the PHT and control rats at a dose of 5 mg/kg while both inhibitors significantly decreased PP after 60 min administration only in the PHT rats. Portal vein ligation treatment induced a significant increase in PP and BFV of the portal vein, gastric mucosa, oesophageal mucosa and the serum levels of 6-keto-PGF1alpha and TXB2, while portal vein ligation treatment induced a significant decrease in BFV of the liver. Both blockades increased MAP and decreased PP and BFV in the splanchnic area and decreased the serum level of 6-keto-PGF1alpha and TXB2 in the PHT rats, while neither blockade modified any parameters in the control rats, except that indomethacin administration significantly decreased the BFV of the gastric mucosa. Indomethacin administration significantly increased the ulcer index (UI). The NS-398 had no effect on UI in either the PHT or control rats. Only indomethacin significantly increased the number of rats demonstrating gastric mucosal long lesions (> 2 cm) in the PHT rats. CONCLUSION: In the PHT rats, prostaglandin seemed to contribute to portal hypertension. Both COX blockades reduced PP and BFV of the portal vein and gastric mucosa. NS-398, a selective COX-2 inhibitor, may, therefore, improve portal hypertension without inducing gastric mucosal injury.

6-Ketoprostaglandin F1 alpha↗
PubMed1999

The effect of carbon dioxide pneumoperitoneum on the portal hemodynamics in a portal-hypertensive rat model.

As use of laparoscopic surgery grows, various complications with pneumoperitoneum have been reported. However, there are no reports on the relation between the carbon dioxide (Co2) pneumoperitoneum and portal hemodynamics. The purpose of this study was to determine how the pneumoperitoneum affects the portal hypertensive state. Portal-hypertensive rats, control rats, and sham operation rats were studied. The mean arterial pressure, portal venous pressure, central venous pressure, red blood flow volume of the viscera, and liver and renal function were investigated. The findings of this study suggest that Co2 pneumoperitoneum at less than 10 mm Hg does not present any undue risk to the portal hemodynamics in portal-hypertensive rats; however, more attention should be paid to the IAP in PHT patients undergoing surgery.

Animals↗
PubMed1998

The development of extrahepatic portal obstruction after undergoing multiple operations for a congenital dilatation of the bile duct: report of a case.

As a long-term complication after undergoing a cystenterostomy for a congenital dilatation of the bile duct, liver cirrhosis due to stenosis of the anastomosis or reflux cholangitis has been reported in conjunction with subsequent portal hypertension. We treated a 48-year-old Japanese woman who developed both portal hypertension and pancytopenia after undergoing multiple operations for a congenital dilatation of the bile duct. She underwent a Hassab's operation in July 1994, when an occlusion of the extrahepatic portal vein, which resulted in portal hypertension, was first noted; the liver was microscopically normal. The etiology of the extrahepatic portal obstruction in our patient was most likely due to either repeated inflammation or adhesion at the hepatic hilus. Based on these findings, the differential diagnosis of portal hypertension after an operation for a congenital dilatation of the bile duct should therefore include an extrahepatic portal obstruction in addition to liver cirrhosis.

Anastomosis, Surgical↗
PubMed1998

Laparoscopic repair of a perforated duodenal ulcer in two patients.

The laparoscopic repair of a perforated duodenal ulcer was effectively done in two patients both of whom were poor risks for surgery. One was a 39-year-old woman with a history of bronchial asthma since she was 20 years of age, while the other was a 76-year-old man with hepatocellular carcinoma, lung cancer, and diabetes mellitus. The postoperative course of these patients was uneventful. Based on these findings, the laparoscopic repair of a perforated duodenal ulcer should thus be considered as a first choice of treatment for a perforated duodenal ulcer, even in poor-risk patients.

Adult↗
PubMed1998

Early experience of endoscopic extirpation of benign breast tumors via an extra-mammary incision.

The early results of 6 patients with a benign breast mass who underwent an endoscopic extirpation via an extra-mammary incision were presented. Under general anesthesia in either a lateral or supine position, a 12-mm and two 5-mm incisions in the infra-mammary line in 2 patients and in the mid-axillary line in the remaining 4 patients were made. The tumors were then endoscopically extirpated. Preoperative aspiration needle cytology revealed six fibroadenomas in 5 patients and one intraductal papilloma in the other patient. All patients were single females with a mean age of 22.5 years. The maximal size of the masses was 5 cm on average. The average operation time was 3 hours 20 minutes. Regarding postoperative complications, subcutaneous emphysema extending to the neck due to CO2 gas inflation and a burn in the skin were seen in 1 patient each; however, no further treatment was required in these cases. The postoperative hospital stay was 1.7 days on average, and all patients were extremely satisfied with the cosmetic results of the procedure. The cosmetic results are drastically improved by the application of endoscopic removal via extra-mammary approaches, which are newly introduced, for benign breast tumors.

Adolescent↗
PubMed1998

Laparoscopic gastric devascularization and splenectomy for sclerotherapy-resistant esophagogastric varices with hypersplenism.

BACKGROUND: The combination of sclerotherapy with surgical salvage for sclerotherapy-resistant esophagogastric varices has recently received much attention, however, the longterm results after such an operation have yet to be reported. This is a preliminary report of a laparoscopic adaptation of a previously described surgical procedure for the treatment of refractory esophagogastric varices. STUDY DESIGN: Laparoscopic gastric devascularization and splenectomy (Hassab's operation) was successfully performed to treat recurrent sclerotherapy-resistant giant esophageal varices (n=4) and recurrent rebleeding gastric varices (n=6). The patients included 8 men and 2 women who ranged in age from 35 to 67 years (average, 54.2 years). The procedure and clinical results were evaluated from various viewpoints. RESULTS: The duration of the operation ranged from 200 to 400 minutes (mean+/-standard deviation; 287.5+/-66.0 minutes) and blood loss from 10 to 1,500 mL (average, 515.5+/-507.9 mL). The weight of the spleen ranged from 500 to 850 g (average 608.0+/-126.6 g). Conversion to minimal open operation with a gasless lifting method was done in 1 patient because of uncontrolled bleeding from the splenic vein. There were no other major complications either intraoperatively or postoperatively. All patients had hypersplenism; preoperative platelet counts ranged from 1.6 to 6.8 x 10(4)/microL (average, 4.5+/-2.7 x 10(4) microL) and the postoperative count was from 5.9 to 36.0 x 10(4)/microL (average, 21.7+/-11.5 x 10(4) microL). Postoperative endoscopy revealed that varices disappeared, and no patient had recurrence of the varices after operation during the mean followup period of 12.8+/-4.1 months (average, 8 to 20 months). CONCLUSIONS: The combination of laparoscopic gastric devascularization and splenectomy for sclerotherapy-resistant esophagogastric varices is considered a feasible and relatively safe surgical method for patients with hypersplenism.

Adult↗
PubMed1998

Morphology and proliferation of B16 melanoma cells in the presence of lanthanoid and Al3+ ions.

The effects of trivalent metal ions such as lanthanoid (La3+, Ce3+, Nd3+, Sm3+, Gd3+, Er3+, Yb3+, Lu3+) and Al3+ ions on the morphological change and proliferation of B16 melanoma cells in culture are discussed. These metal ions induced morphological transformations and decreased growth rates at doses of 1 mM. B16 melanoma cells treated with La3+, Ce3+, Nd3+, Sm3+, and Gd3+ showed polyhedrical spreading. Elongation of axones was dependent on the metal ions. B16 melanoma cells treated with Er3+, Yb3+, Lu3+, and Al3+ showed a long slender shape. Growth rates of melanoma cells in the presence of 1 mM of metal ions (La3+, Ce3+, Nd3+, Sm3+, Gd3+, Yb3+, Al3+) were significantly lower than that of control cells. Measurements of cell cycle indicated that the metal ions arrested the transitions from G0/G1 to S state.

Aluminum↗