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Biomedical subjects

M Tomikawa

Publications and source records attributed to M Tomikawa.

At least 109 records · Page 6Linked to original sources
PubMedDate not supplied

A prospective randomized trial comparing pneumoperitoneum and U-shaped retractor elevation for laparoscopic cholecystectomy.

Between April and August 1991, 83 Japanese patients with symptomatic gallstones underwent laparoscopic cholecystectomy in our clinics. A prospective randomized trial was carried out to examine the safety, efficacy, and complications of the two techniques, pneumoperitoneum vs an elevating method using a U-shaped retractor. Forty-two patients were randomly allocated to the pneumoperitoneum (P) group and 41 to the U-shaped retractor (U) group. These two groups were well matched with respect to age, sex, etiology, and the severity of the chronic cholecystitis. Laparoscopic resection was successful for 88.1% (37/42) in the P group and 100% (41/41) in the U group. In patients with a severe fibrotic gallbladder, the rate of success was significantly higher (P < 0.05) in the U group (100%, 6/6) than in the P group (11.8%, 1/6). In the moderately inflamed group, the operation time (mean +/- SD) was significantly (P < 0.01) less in the U group (58.7 +/- 22.7) than in the P group (87.3 +/- 18.3). With the U-shaped retractor the usual surgical instruments can be used, and a rapid and safer laparoscopic cholecystectomy can be carried out. We prefer this approach to a pneumoperitoneum for patients with an inflamed gallbladder as hospital stay and pain are minimal.

Cholecystectomy, Laparoscopic↗
PubMedDate not supplied

A safe and simple method to maintain a clear field of vision during laparoscopic cholecystectomy.

A clear field of vision during laparoscopic cholecystectomy was attained by using a newly designed retractor which elevates the abdominal wall and does not require high-pressure CO2 infusion into the peritoneal cavity. As the abdominal cavity is continuously ventilated, smoke from the cauterization is suctioned off through openings in the middle part of the retractor. There is no interference with placement of ports.

Cholecystectomy↗
PubMedDate not supplied

Antacid talcid activates in gastric mucosa genes encoding for EGF and its receptor. The molecular basis for its ulcer healing action.

In previous studies [Gut 35 (1994) 896-904], we demonstrated that antacid talcid (TAL) accelerates gastric ulcer healing and provides better quality of mucosal restoration within the scar than the omeprazole (OME). However, the mechanisms of TAL-induced ulcer healing are not clear. Since growth factors promote cell proliferation, re-epithelization, angiogenesis and ulcer healing, we studied whether TAL and/or OME affect expression of epidermal growth factor (EGF) and its receptors (EGF-R) in both normal and ulcerated gastric mucosae. Rats with or without acetic acid-induced gastric ulcers (n = 64) received i.g. twice daily 1 mL of either: A) placebo (PLA); B) TAL 100 mg; or C) OME 50 mg x kg(-1) for 14 d. Studies of gastric specimens: 1) ulcer size; 2) quantitative histology; 3) expression of EGF mRNAs was determined by RT/PCR; 4) gastric sections were immunostained with antibodies against EGF and its receptors. In non-ulcerated gastric mucosa of placebo or omeprazole treated group, EGF expression was minimal, while EGF-R was localized to few cells in the mucosal proliferative zone. Gastric ulceration triggered overexpression of EGF and its receptor in epithelial cells of the ulcer margin and scar. In ulcerated gastric mucosa TAL treatment significantly enhanced (versus PLA and omeprazole) expression of EGF and EGF-R. OME treatment reduced expression of EGF in ulcerated mucosa by 55 +/- 2% (P < 0.01). It is concluded that: 1) treatment with TAL activates genes for EGF and its receptor in normal and ulcerated gastric mucosae; 2) since EGF promotes growth of epithelial cells and their proliferation and migration, the above actions of TAL provide the mechanism for its ulcer healing action and improved (versus OME) quality of mucosal restoration.

Aluminum Hydroxide↗
PubMedDate not supplied

New insights into impairment of mucosal defense in portal hypertensive gastric mucosa.

Portal hypertension (PHT) increases susceptibility of the gastric mucosa to injury. The aim of this study was to investigate whether PHT affects rat gastric mucosal defense mechanisms in vivo at the pre-epithelial, epithelial, and/or post-epithelial levels. PHT was produced in rats by staged portal vein ligation and sham-operated (SO) rats served as controls. The gastric mucosa was exposed, chambered, and continuously superfused with buffers under in vivo microscopy. We measured gastric mucosal gel layer thickness, surface epithelial cell intracellular pH (pHi), mucosal blood flow, and mucosal/serosal oxygenation. In PHT rats, gastric mucosal gel layer thickness was significantly reduced (88 +/- 16 microm in PHT rats vs. 135 +/- 25 microm in SO rats; P <0.0001), and the surface epithelial cell pHi was significantly decreased (6.80 +/- 0.11 in PHT rats vs. 7.09 +/- 0.21 in SO rats; P <0.01). Although total gastric mucosal blood flow was significantly increased in PHT rats by 72% (P <0.05), the oxygenation of the gastric mucosal surface was decreased by 42% (P <0.05) compared with SO rats. PHT impairs pre-epithelial (mucosal gel layer thickness), epithelial (pHi), and post-epithelial (maldistribution of blood flow) components of the gastric mucosal barrier. These findings can explain the increased susceptibility of portal hypertensive gastric mucosa to injury.

Animals↗
PubMedDate not supplied

Preventive effect of argatroban on ellagic acid-induced cerebral thromboembolism in rats.

The preventive effect of argatroban, a synthetic thrombin inhibitor, on cerebral infarction was evaluated with ellagic acid (EA)-induced cerebral thromboembolism in rats. Platelet-rich thrombi containing fibrin and EA crystal were formed in the microarteries in the affected hemisphere by the injection of EA suspension into the cerebral arteries. The mortality in saline control was over 80% 6 h after the EA injection. Argatroban decreased the mortality to 0% at a dose of 3 mg/kg/h, and significantly reduced the ischemic area in the affected cerebral hemisphere. Heparin also decreased the mortality to 30% at a dose of 600 U/kg/h, but marked bleeding was observed at the incised wound. These findings suggest that argatroban is a more effective and safer anticoagulant than heparin for the prevention of ischemic damage on cerebral thrombosis.

Animals↗
PubMedDate not supplied

Characterization and tissue distribution of liposomes containing lactose mono-fatty acid derivatives.

In this study we characterized liposomes containing the synthetic glycolipids, lactose mono-fatty acid esters (LFEs), whose structures were the most simple ones compared to the other synthetic glycolipids. Gel filtration chromatography was used to confirm that 78 per cent of lactose monostearic acid ester (LSE) or 85 per cent of lactose monoarachidic acid ester (LAE) existed in the liposomal fraction. The size distribution of liposomes containing LFEs was similar to that of the control liposomes which did not contain LFEs. Liposomes containing LFEs were aggregated by Ricinus communis agglutinin from caster bean (RCA120) while the control liposomes were not, with the agglutinability of the liposomes containing LAE being greater than that of those containing LSE. These findings therefore suggested that the LFEs were incorporated into the liposomal membrane with the galactose residues exposed to the outer aqueous phase. Next, the tissue distribution of liposomes containing LAE at 30 min after intravenous administration was compared to that of the control liposomes in rats. Hepatic uptake was 2-fold higher than that of the control liposomes. These results thus demonstrate that liposomes containing LFEs represent potential drug carriers to the liver.

Animals↗
PubMedDate not supplied

Selective uptake of liposomes containing lactose mono-fatty acid derivatives by hepatic parenchymal cells.

In this study we investigated the hepatic uptake of liposomes containing a novel synthetic glycolipid, lactose mono-arachidic acid amide (LAA). Liposomes containing LAA were aggregated by Ricinus communis agglutinin from caster bean, while the control liposomes were not, and the results suggested that the galactose residues of LAA were exposed to the outer surface of the liposomes. Next, the blood clearance and hepatic uptake of liposomes containing LAA after intravenous administration were compared with those of the control liposomes in rat. Hepatic uptake of liposomes containing LAA was greater than that of the control liposomes, rising significantly with dose. As a result of separation of the parenchymal and non-parenchymal cells, it was shown that the increase in hepatic uptake was mostly accounted for by a greater uptake by parenchymal cells. The inhibitory activity of asialofetuin on the hepatic uptake of liposomes containing LAA suggested that a galactose-specific recognition is involved in this uptake. These results demonstrate that the lactose mono-fatty acid amides (LFAs) are promising novel compounds for the introduction of carbohydrate residues onto the liposomal surface and that liposomes containing LFAs are potential carriers for the selective delivery of drugs to specific cells.

Amides↗
PubMedDate not supplied

Distribution of liposomes containing mannobiose esters of fatty acid in rats.

The biodistribution of liposomes modified by mannobiose residues was studied in rat. The purpose of the modification was to target the liposomes to macrophages. Mannobiose mono arachidic acid esters (MAEs) were synthesized and used to modify the surface of liposomes. It was shown by gel permeation chromatography that the MAE was preferentially incorporated into the membrane of the liposomes. After intravenous administration, mannobiose-modified liposomes were eliminated from the systemic circulation more rapidly than control liposomes without the modification. Whilst the modification did not affect the distribution of liposomes to kidney, lung, or thymus, it increased the distribution to liver and spleen. The uptake in the hepatic parenchymal cell fraction was not influenced by MAE incorporation. Taking into account the fact that endothelial cells do not take up particles whose size is > 100 nm, the increase in the distribution to liver were ascribed to an increase in uptake by Kupffer cells. These results suggest that mannobiose mono fatty acid esters are useful in the targeting of liposomes to Kupffer cells and other macrophages.

Animals↗
PubMedDate not supplied

Systemic effects of ethanolamine oleate in analbuminemic rats.

BACKGROUND/AIMS: The present study was an attempt to clarify whether only serum albumin inactivates ethanolamine oleate (EO) in vivo and whether EO has an adverse effect on the lung, kidney, and liver in the presence of analbuminemia. METHODOLOGY: Fifty-five female Nagase Analbuminemia Rats (NAR) and 55 female Sprague-Dawley Rats (SDR) were injected with 5% EO in the left femoral vein. Changes in respiratory, renal, and hepatic function and the extent of hemolysis following the injection of the EO were examined. RESULTS: In both groups, a transient but significant increase was seen in serum hemoglobin at up to 1 hour after injection of EO. No significant changes in PaO2, PaCO2, blood urea nitrogen, or serum creatinine following injection of EO were seen in either group. The total bilirubin significantly increased within 30 min in the SDR group, but this increase was prolonged for 5 days in the NAR group. Glutamic pyruvic transaminase (GPT) increased for 12 hours in the NAR group, while no change was seen in the SDR group. CONCLUSIONS: These observations suggest that EO may have hepatotoxic effects, that serum albumin may afford protection, and that other humoral substances which inactivate EO, including serum globulin, may be present.

Alanine Transaminase↗
PubMedDate not supplied

Laparoscopic splenectomy: the latest modern technique.

BACKGROUND/AIMS: Recent advances in technical instruments have resulted in increased safety and simplicity in laparoscopic surgery. The purpose of this article is to introduce our latest operative techniques for laparoscopic splenectomy. METHODOLOGY: The patient is placed in the right semidecubitus position and the gastrosplenic ligament including the short gastric vessels was performed by using an ultrasonically activated scalpel. The splenic artery and vein were resected at the splenic hilum with an autosuture device. The electromechanical morcellator was used to remove the spleen. RESULTS: The laparoscopic splenectomy was successfully performed in all 74 patients from 1992-1997. There was no deaths related to the operation. Conversion to open surgery with a small incision of 5 cm was required in one patient with advanced liver cirrhosis and portal hypertension and 45 patients with portal hypertension. CONCLUSIONS: A laparoscopic splenectomy is considered to be a safe and feasable modality for the treatment for hematologic disorders of both the spleen and other benign tumors.

Humans↗
PubMedDate not supplied

Laparoscopic splenectomy for splenic artery aneurysm.

Two cases undergoing a laparoscopic splenectomy for the treatment of a splenic artery aneurysm are herein reported. This lesion is relatively rare. Surgical treatment is indicated for such cases since approximately 10% of these aneurysms tend to rupture which thus results in fatal hemorrhaging. Both cases demonstrated aneurysms measuring more than 2 cm in diameter based on the ultrasonography, computed tomography and celiac angiography findings and, as a result, a laparoscopic splenectomy was thus prophylactically performed. This procedure is the preferred technique for high risk patients, such as those with chronic renal failure, as observed in case 1, since patients can be spared the disadvantages of undergoing a laparotomy.

Aneurysm↗
PubMedDate not supplied

5-fluorouracil sensitivity and dihydropyrimidine dehydrogenase activity in advanced gastric cancer.

BACKGROUND: Dihydropyrimidine dehydrogenase (DPD) is the rate-limiting enzyme of 5-fluorouracil (5-FU) catabolism. Several studies have demonstrated the clinical importance of DPD in cancer patients, suggesting that the efficacy of 5-FU may be related to DPD activity in tumor tissue. In the present study, DPD activity and chemosensitivity to 5-FU were evaluated in advanced gastric cancer. MATERIALS AND METHODS: Thirty-four gastric cancers from 32 patients were studied and chemosensitivity to 5-FU was evaluated by histoculture drug response assay. RESULTS AND CONCLUSION: DPD activity and tumor inhibition of 5-FU among all cases showed no significant correlation, but among 14 histologically differentiated cases significant correlation was observed. DPD activity may be useful in determining the 5-FU sensitivity of differentiated gastric cancer.

Antimetabolites, Antineoplastic↗
PubMedDate not supplied

The therapeutic strategies in performing emergency surgery for gastroduodenal ulcer perforation in 130 patients over 70 years of age.

BACKGROUND/AIMS: Gastroduodenal ulcer is a very common illness in Japan. As the number of elderly persons in Japan increases the same as in Europe and America, the number of such patients requiring a gastroduodenal emergency operation has also increased. Regarding the complications of peptic ulcer, a perforation remains the most important fatal complication. The aim of this study is to investigate the operative risk factors and the long-term recurrence rates and to define the optimal surgical procedures in emergency situations in elderly patients. METHODOLOGY: From April 1988 through March 1997, 130 patients over 70 years of age with a perforated gastroduodenal ulcer (a duodenal ulcer perforation in 50 patients and a gastric ulcer perforation in 80 patients) were operated on in an emergency situation in our clinic. We investigated the following items; medical illness, preoperative risk factor, optimal surgical procedure, postoperative organ failure and the cumulative recurrence-free rates after surgical treatment. RESULTS: A significant correlation with mortality was observed in patients with established comorbidity in the following organs: lung (P = 0.03), heart (P = 0.02), kidney (P = 0.04), and diabetes (P = 0.03). The highest postoperative mortality rate was recorded in patients who underwent a simple closure of a duodenal ulcer perforation (4 patients; 26.7%), while the lowest postoperative mortality rate was recorded in patients who underwent a simple closure and vagotomy of a duodenal ulcer perforation (3 patients; 12.5%). In gastric ulcers, the mortality rate in patients with a gastrectomy was significantly higher than in patients with a simple closure. The practical application of the three risk factors (preoperative shock, delay to surgery over 24 hours, and medical illness) was shown by the progressive rise in the mortality rate with the increasing number of risk factors. Based on the 5 postoperative years after treating a perforated duodenal ulcer, the cumulative recurrence rate after a simple closure (63.6%) was significantly higher than that after a simple closure and vagotomy (38.1%) (n = 0.02) or after gastrectomy (0%) (P < 0.001). At 5 years postoperatively, the cumulative recurrence rate after a simple closure (41.2%) was significantly higher than that after a gastrectomy (15.9%) (P < 0.01). CONCLUSIONS: In conclusion, in an emergency situation, elderly patients are in a highly unfavorable prognostic condition due to their advanced age, and comorbidity, which thus leads to poorer results, not only worldwide, but also in Japan. Based on our findings, in duodenal ulcer cases, a simple closure and vagotomy is recommended because of its low mortality and minimal stress, except for cases with a giant perforation measuring over 20 mm in diameter at the perforation hole or with severe duodenal stenosis. In stomach ulcer cases, a gastrectomy may be recommended because of its low recurrence rate.

Age Factors↗
PubMedDate not supplied

Hyperbilirubinemia induced by endoscopic variceal ligation for esophageal varices in a patient with primary biliary cirrhosis: a case report.

We describe the case of a 51-year-old woman with primary biliary cirrhosis who developed hyperbilirubinemia with transient liver dysfunction after undergoing endoscopic variceral ligation to control hemorrhaging from esophageal varices. After undergoing a variceal ligation, the serum total bilirubin increased from 4.0 mg/dL to 9.5 mg/dL, and the degree of liver failure worsened. She finally had to undergo a liver transplant. We discuss the mechanism of hyperbilirubinemia after endoscopic variceal ligation.

Endoscopy↗
PubMedDate not supplied

Sclerotherapy-resistant esophageal varices with enormously enlarged cephalad collateral vessels predictable using portography.

BACKGROUND/AIMS: The most common cause of failure of sclerotherapy is recurrent bleeding before eradication is complete. We investigated factors which would make feasible prediction of cases where esophageal varices would be more difficult to eradicate. PATIENTS AND METHODS: Seven hundred and seventy patients underwent endoscopic injection sclerotherapy at Kyushu University Hospital from January, 1982 to June, 1989. For 580 of these patients we used the same sclerosant and a transparent overtube. For 19 of 580 patients over two months were needed to eradicate the varices (group 2), while eradication was complete in less than one month in 64 patients (group 1). RESULTS: There was a tendency toward a lower platelet count and a higher indocyanine green retention rate in group 2, but with no statistically significant difference. The number of sessions required for eradication of the varices was 8.1 +/- 2.5 and the total volume of sclerosant used was 98.2 +/- 62.3 ml in group 2, and 3.0 and 47.0 +/- 10.9 ml, respectively, in group 1 (p < 0.01). There was no significant difference in the number of sessions between the patients with large-sized and moderate-sized varices. Based on the extent of cephalad collateral vessels on the venous phase of celiac or superior mesenteric angiography, the vascular pattern could be classified into three types; Grade III, the most developed type was present in 100% and 57.1% on celiac and superior mesenteric angiography in group 2, while the rates were 11.1% and 5.6% in group 1 (p < 0.05). CONCLUSIONS: This retrospective study shows that in patients with enormously enlarged cephalad collateral vessels it may be difficult to eradicate the varices, and in such cases, preoperative portography is most useful to predict whether or not esophageal varices can be eradicated.

Collateral Circulation↗
PubMedDate not supplied

A safe technique for laparoscopic cholecystectomy for incarcerated gallbladder stone.

BACKGROUND/AIMS: We present our new laparoscopic technique for treating incarcerated stones in either the cystic duct or the neck of the gallbladder. PATIENTS AND METHODS: One hundred sixteen patients who underwent laparoscopic cholecystectomy were studied. RESULTS: In all, 18 patients (16%) were found to have incarcerated stones in gallbladder or cystic duct. Eleven patients were drip infusion cholangiography (DIC) negative. The length of the operative time for these patients was significantly longer than that in non-incarcerated stone cases. We present our new laparoscopic technique for treating incarcerated stones in either the cystic duct or neck of the gallbladder and this procedure includes a needle aspiration of the bile juice, the transsection and removal of the incarcerated stone and an extracorporeal ligation. CONCLUSIONS: This above procedure was successfully performed on a series of 4 patients. Our procedure is therefore considered to allow us to complete a laparoscopic cholecystectomy even in extremely hypertrophic cases with incarcerated stones either in the cystic duct or Hartmann's pouch.

Adult↗