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M Tomikawa

Publications and source records attributed to M Tomikawa.

At least 19 recordsLinked to original sources
PubMed2002

Early experiences of endoscopic procedures in general surgery assisted by a computer-enhanced surgical system.

We performed a variety of complete total endoscopic general surgical procedures, including colon resection, distal gastrectomy, and splenectomy, successfully with the assistance of the da Vinci computer-enhanced surgical system. The robotic system allowed us to manipulate the endoscopic instruments as effectively as during open surgery. It enhanced visualization of both the operative field and precision of the necessary techniques, as well as being less stressful for the endoscopic operating team. This technological innovation can therefore help surgeons overcome many of the difficulties associated with the endoscopic approach and thus has the potential to enable more precise, safer, and more minimally invasive surgery in the future.

Adult↗
PubMed2001

Despite activation of EGF-receptor-ERK signaling pathway, epithelial proliferation is impaired in portal hypertensive gastric mucosa: relevance of MKP-1, c-fos, c-myc, and cyclin D1 expression.

Portal hypertensive (PHT) gastric mucosa has increased susceptibility to injury and impaired mucosal healing. Our previous study demonstrated increased ERK activation and MAP kinase phosphatase-1 (MKP-1) overexpression in PHT gastric mucosa. However, it remains unknown which tyrosine kinase receptors are involved in ERK activation and whether ERK activation results in increased cell proliferation. We examined whether EGF receptor (EGF-R) is involved in ERK activation and whether ERK activation triggers epithelial proliferation in PHT gastric mucosa. In gastric mucosa of PHT and sham-operated (SO) rats we studied: (1) EGF-R mRNA and protein expression as well as phosphorylation and membrane protein tyrosine kinase (PTK) activity; (2) ERK2 phosphorylation and activity; (3) MKP-1 mRNA and protein; (4) c-fos, c-myc and cyclin D1 mRNAs, and gastric epithelial proliferation. In PHT gastric mucosa: (1) EGF-R mRNA, protein and phosphorylation and membrane PTK activity were all significantly increased by 38%, 49%, 43% and 49%, respectively; (2) ERK2 phosphorylation and activity were significantly increased by 40% and 50 %, respectively; (3) MKP-1 mRNA and protein expression were significantly increased by 27% and 34%, respectively. In contrast, (4) c-fos, c-myc, and cyclin D1 mRNAs expression were all significantly decreased in PHT gastric mucosa by 36%, 33%, and 49%, respectively, and cell proliferation was significantly lower that in SO rats (11% in PHT vs. 18% in SO). These results suggest that in PHT gastric mucosa, ERK activation is mediated through EGF-R upregulation, but the gastric epithelial proliferation is impaired, possibly by MKP-1 overexpression, leading to reduction of c-fos, c-myc and cyclin D1.

Animals↗
PubMed2001

Portal hypertensive gastric mucosa has reduced activation of MAP kinase (ERK2) in response to alcohol injury: a key to impaired healing?

Portal hypertensive (PHT) gastric mucosa has increased susceptibility to injury and impaired mucosal healing. Because our previous study showed that ulcer-induced activation of mitogen-activated protein (MAP) kinase (ERK) plays a pivotal role in gastric mucosal healing, we investigated whether ERK activation is altered in PHT gastric mucosa following alcohol injury. We studied ERK2 phosphorylation and activity and expression of MAP kinase phosphatase-1 (MKP-1) in gastric mucosa of PHT and sham-operated (SO) normal rats both at baseline and following alcohol injury. In SO gastric mucosa, ERK2 phosphorylation and activity were significantly increased time-dependently following alcohol injury: by 221% and 137%, respectively at 24 h vs. baseline. In contrast, in PHT gastric mucosa following alcohol injury, neither ERK2 phosphorylation nor activity was increased versus baseline. In PHT gastric mucosa, MKP-1 mRNA and protein expression were increased at baseline versus SO rats and were increased further following alcohol injury with values higher by 20%-40% at each study time versus SO rats. Because ERK2 is crucial for mucosal healing, reduced ERK2 activation resulting from the overexpression of MKP-1 might be the basis for the impaired mucosal healing in PHT gastric mucosa.

Alcohols↗
PubMed2001

Human mast cell progenitors in peripheral blood from atopic subjects with high IgE levels.

BACKGROUND: It remains unclear whether the number of circulating mast cell progenitors is increased in patients with atopic diseases. Distinct genotypes are reported to affect mast cell/basophil activation. OBJECTIVE: We compared the number and function of mast cell progenitors present in the peripheral blood from donors with normal IgE (IgE < 400 U/mL) and those with atopic dermatitis accompanied by high serum IgE (IgE > 5000 U/mL). METHODS: Purified peripheral blood cells were cultured in serum-free methylcellulose containing stem cell factor (SCF), IL-6 plus IL-3. Fresh methylcellulose containing the cytokines was layered over every 2 weeks. The cultured mast cells were retrieved from the methylcellulose and were functionally analysed. RESULTS: Mast cell colonies were distinguished at 6 weeks of culture as other colony types had been degenerated. The number of mast cell colony-forming cells varied depending on donors and was not significantly increased in peripheral blood from the hyper-IgE atopic patients. A significant inversed correlation was found between the number of mast cells per one colony and the ages of donors. The cultured mast cells derived from atopic patients and those from normal IgE donors equally expressed Fc epsilon RI and released histamine through Fc epsilon RI, although IL-4 priming in vitro markedly enhanced the function of mast cells regardless of donors. CONCLUSIONS: These results indicate that the number of circulating mast cell progenitors may be regulated by unknown individual factors unrelated to IgE levels. Mast cell function may be regulated largely by environmental factors, such as IL-4, but not determined by their progenitors' genotypes.

Adolescent↗
PubMed2001

Immunohistochemical localization of vascular endothelial growth factor in the rat portal hypertensive gastropathy.

BACKGROUND AND AIMS: Portal hypertensive gastropathy (PHG) is now recognized to be a distinct entity. Recently, angiogenesis has been noticed as a key factor in clarifying the pathophysiology of various diseases. Angiogenesis in the PHT of explored gastric mucosa has yet to be explored. Vascular endothelial growth factor (VEGF) is a potent angiogenic factor. The aim of the present study was thus to investigate whether the hypoxic state exists in PHG, and whether VEGF appears more strongly in PHG than in normal gastric mucosa and, if so, what exactly is the role of the hypoxic state and VEGF in PHG. METHODS: At 1, 3, 7 and 14 days after either a portal ligation or sham operation, the portal venous pressure, the gastric mucosal blood flow volume and the blood gas were measured and, the expression of VEGF and antiproliferating cell nuclear antigen (PCNA) in gastric mucosal specimens was immunohistochemically assessed. RESULTS: The portal pressure (PP) and the gastric mucosal blood flow (GMBF) in the PHT rats were significantly greater than in the control (CTR). Both the SaO2 and PaO2 of the arterial blood gas were lower in the PHT rats than in the control rats. The percentage of VEGF expression in the PHG was found to be higher than that in the control gastric mucosa. The percentage of PCNA expression in the PHG was higher than that in the control gastric mucosa. CONCLUSION: The levels of SaO2 and PaO2 were lower in the PHT rats. There is a possibility that a kind of portal hypertensive gastric change may trigger an enhanced histochemical expression of VEGF. The increased activity of VEGF may have a possibility of the hypoxic gastric mucosal state caused by the presence of active congestion. This damaged mucosal state 'PHG' may thus facilitate the fragility in PHG and such lesions may be slow and insidious, which may therefore lead to sudden and severe anemia, thus causing massive and sometimes fatal hemorrhaging.

Animals↗
PubMed2001

Defective mitogen-activated protein kinase (ERK2) signaling in gastric mucosa of portal hypertensive rats: potential therapeutic implications.

Portal hypertensive (PHT) gastropathy is a frequent, serious complication of liver cirrhosis. PHT gastric mucosa has numerous abnormalities such as reduced mucosal potential differences, reduced surface oxygenation, and increased susceptibility to injury caused by alcohol, aspirin, and other noxious factors. Because such mucosal injury is initially mediated by oxygen free radicals, and because mitogen-activated protein (MAP) kinase (ERK2) protects against cellular stress and induces cell proliferation, we postulated that oxidative stress-induced ERK2 activation is defective in PHT gastric mucosa. Here we show that in PHT gastric mucosa, ERK2 activation by oxidative stress is impaired. This impairment is mediated by overexpression of MAP kinase phosphatase-1 (MKP-1), which results from the underlying and continual oxidative state associated with portal hypertension, and is ameliorated by inhibiting MKP-1. Furthermore, we found that supplementing vitamin E, a free radical scavenger, reduces the oxidative state in PHT gastric mucosa, normalizes MKP-1 expression, and thereby reverses impairment of oxidative stress-induced ERK2 activation. Finally, we show that orally administered vitamin E completely reverses the increased susceptibility of PHT gastric mucosa to alcohol injury. Our findings point to a new molecular and mechanistic basis for PHT gastropathy and provide a new therapeutic modality for protection of PHT gastric mucosa.

Animals↗
PubMed2001

Carcinoma of the colon metastatic to the lower gingiva.

A case of carcinoma of the colon that metastasized to the lower gingiva is described. The patient who had carcinoma of the colon developed a proliferating lesion at the site of a recent tooth extraction. A few days later, the primary site of the malignancy appeared. The clinical features in such cases were reviewed in studies by others, most of which were of oral and dental surgery. Thus, because of our case, gastroenterologists should consider the possibility of gingival metastasis from malignant disease such as colorectal cancer.

Aged↗
PubMed2001

[A boy diagnosed SLE after Staphylococcus aureus infection over a long period].

We encountered a 13-year-old boy with SLE who showed specific pathophysiology. The affected child was hospitalized because of long-standing cutaneous empyesis considered to be Staphylococcus aureus infection, followed by manifestation of meningoencephalitis-like symptoms. On a close check up, the patient was diagnosed as having SLE complicated with interstitial lupus nephritis and verrucosis of the left ventricle. Besides the findings, the blastogenesis of the patient's lymphocyte was low against stimulation of sac-1 which connects with the Fc portion of lgG, one of the constituent proteins of Staphylococcus. Moreover, anti-phospholipid antibodies turned positive during immunosuppressive therapy and subcutaneous abscess due to Pseudomonas aeruginosae developed concurrently at about the same time, which posed difficulties in the treatment. The affected child had had Staphylococcus aureus infections over a long period of time before diagnosis of SLE and was susceptible to bacterial infections due to Pseudomonas aeruginosae during the treatment. The clinical course of this case was considered important in presuming the complex immunologically abnormal condition of SLE in childhood.

Adolescent↗
PubMed2001

A comparison of an open and laparoscopic appendectomy for patients with liver cirrhosis.

Liver cirrhosis is a critical factor contributing to morbidity and mortality in abdominal surgery, because patients with cirrhosis have a particularly high risk of developing bleeding, infection, and ascites. Laparoscopic appendectomy (LA) recently has gained a lot of attention around the world; however, comparisons between the benefits of LA and those of conventional open appendectomy (OA) for patients with liver cirrhosis have yet to be sufficiently compiled. In the present retrospective study, 40 patients with liver cirrhosis who were diagnosed with acute appendicitis before surgery underwent an appendectomy (OA in 25 patients and LA in 15 patients). This study focused on the operative time, amount of postoperative pain, use of analgesics, the restart of a normal diet, number of complications, length of hospital stay, and cost-effectiveness of the procedure in such patients. The amount of postoperative pain and the length of hospital stay were significantly smaller in the LA group. The mean values of the serum C-reactive protein on postoperative days 1, 3, and 7 were significantly less in the LA group. The number of wound infections and wound bleeding was also less in the LA group. The difference in the total cost of hospitalization was not significant. The cost of the operation was greater in the LA group than in the OA group, whereas the hospitalization cost in the LA group was less than that in the OA group. The results of this study suggest that LA may be superior to OA for the treatment of postoperative pain and postoperative complications for patients with liver cirrhosis. Long-term follow-up studies are still necessary, however, to determine any possible decrease in the number of late complications.

Aged↗
PubMed2001

[Current status and future of surgical robotic systems].

In this review, we are commenting the current status and the future of surgical robotic systems. AESOP is a voice-controlled laparoscope manipulator that enables the "Solo-surgery". ZEUS is a master-slave manipulator that is characterized by its simplicity and lightness. da Vinci is another master-slave manipulator that has more range of freedom, therefore a surgeon can perform the operation with fewer difficulties. The technological development of high-quality and real-time 3D simulation, minimization of scopes and power saving techniques made these surgical robots realized. Although many pending matters such as lack of safety guideline or lack of accuracy of sensor/monitor have been raised in current surgical robotics, the development of the technologies may promise to resolve such matters in the future.

Forecasting↗
PubMed2001

Surgical strategy and outcomes for epileptic patients with focal cortical dysplasia or dysembryoplastic neuroepithelial tumor.

PURPOSE: The purpose of this study was to clarify and compare the influence of surgical strategy on relief from seizures in patients with focal cortical dysplasia (FCD) and those with dysembryoplastic neuroepithelial tumor (DNT). METHODS: Six patients with FCD and five patients with DNT, all of whom underwent surgical resection for medically intractable epilepsy, were compared in terms of presurgical seizure types and frequency, location of lesions, magnetic resonance imaging (MRI), single-photon emission computed tomography (SPECT) with 99mTc-ECD, scalp electroencephalogram (EEG), and long-term video-EEG recording. Prolonged subdural recordings and intraoperative electrocorticograms (ECoG) were analyzed. The influences of surgical strategies on seizure outcomes were retrospectively analyzed. RESULTS: In all the FCD patients, ictal SPECT revealed hyperperfusion in the regions where MRI showed FCD. Interictal epileptiform activity and ictal seizure onset on ECoG performed with subdural electrodes were localized on the FCD itself. In contrast, the tumors of all the DNT patients were depicted as hypoperfuse areas on interictal SPECT scans. Ictal SPECT in one DNT patient showed hyperperfusion in the area enclosing the tumor. Interictal spiking in all DNT patients and ictal seizure onset in two DNT patients were not in the lesions themselves but in an area enclosing the lesion. All but one patient with FCD who underwent total lesionectomy became seizure free. All DNT patients who underwent resection of the epileptogenic cortex associated with lesionectomy became seizure free or achieved a 90% reduction in seizures. CONCLUSIONS: FCD has intrinsic epileptogenicity, whereas DNT is encompassed by epileptogenic cortical areas. Therefore, total lesionectomy is an essential strategy for FCD, whereas resection of the epileptic focus associated with lesionectomy of a DNT lesion is necessary to control seizures.

Adolescent↗
PubMed2001

Neuropsychological changes after surgical treatment for temporal lobe epilepsy.

PURPOSE: The effect of unilateral temporal lobectomy on seizure frequency is well recognized, but little is known about the neuropsychological changes that occur after surgical treatment. We assessed neuropsychological status in 26 patients with an average age of 35 years before and after unilateral temporal lobectomy for medically intractable TLE. METHODS: Neuropsychological examination to assess cognitive function, memory, attention, visuospatial analysis, language, and emotional functions was performed preoperatively and at 1 month and 1 year after the surgery. RESULTS: At both 1 month and 1 year after the surgery, the patients had improved scores, compared with the preoperative scores, on the Wechsler Adult Intelligence Scale-Revised (WAIS-R: verbal IQ, performance IQ, and full-scale IQ), Wechsler Memory Scale-Revised (WMS-R: verbal, general, and delayed paired associates memory), and Raven Colored Progressive Matrices. In the Minnesota Multiphasic Personality Inventory (MMPI), significant decreases were observed at 1 year after the surgery in the scores for infrequency, hypochondriasis, psychasthenia, and schizophrenia. Patients in whom the seizures had been relieved postoperatively also had improved scores on the WAIS-R, WMS-R, and Raven Colored Progressive Matrices. CONCLUSIONS: These data suggest that neuropsychological improvement postoperatively is influenced by the reduction in the frequency of seizures after surgery.

Adult↗
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

Sequential expression of adrenomedullin and its receptor during gastric ulcer healing in rats.

Adrenomedullin (AM) is a potent vasodilatory peptide. While its growth-regulating action in some cultured cells has been recognized, expression of AM and its receptor during gastric ulcer healing has not been explored. Specimens of gastric walls from control rats or gastric ulcers were obtained at 1, 3, 7, and 14 days after gastric ulcer induction. AM and its receptor mRNAs expression were determined by reverse transcription-polymerase chain reaction (RT-PCR) and in situ hybridization. By RT-PCR, AM mRNA was increased by 167% at three days, while AM receptor mRNA was increased by 234% at seven days (both P < 0.05). By in situ hybridization, AM and AM receptor mRNAs were increased at ulcer margin from three days after ulcer induction. By immunohistochemistry, AM was increased in the ulcer margin at three and seven days. In separate in vitro studies using a rat gastric epithelial (RGM1) cell line, AM treatment significantly increased transforming growth factor-alpha mRNA expression and cell proliferation.

Adrenomedullin↗
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↗