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M Kitajima

Publications and source records attributed to M Kitajima.

At least 91 records · Page 5Linked to original sources
PubMed2000

[Surgery using master-slave manipulators and telementoring].

Master-slave manipulators enhance surgeons' dexterity and improve the precision of surgical techniques by filtering out surgeons' tremors and scaling the movements of surgical instruments. Among clinically available master-slave manipulators, the epoch-making system called "da Vinci" developed by Intuitive Surgical Inc. (Mountain View, CA, USA), equipped with 2 articulated joints at the tip of the surgical instruments allowing 7 degrees of freedom, mimics the movements of surgeons' wrists and fingers in the abdominal or thoracic cavity. Today advanced telecommunications technology provides us excellent motion images using only 3-ISDN telephone lines. Experienced surgeons at primary surgical sites have been able to perform complex procedures successfully by consulting specialists at remote sites. Because telecommunications costs have become lower each year, telementoring will be come a routine surgical practice in the near future. The usefulness of surgical telementoring has been greatly enhanced by the development of a technique to illustrate on video images from two directions. Moreover, remote advisory surgeons will be able to provide the optimal operative field to operating surgeons using robotic camera holders with voice-recognition systems. In the near future, when master-slave manipulators will also be coupled with telementoring systems, remote experts could actually perform complex surgical procedures.

Humans↗
PubMed2000

[The validity of the sentinel node concept in gastrointestinal cancers].

Although the sentinel node concept has been validated and clinically applied to breast cancer and malignant melanoma, its clinical significance in other solid tumors has not been thoroughly investigated. With regard to gastrointestinal (GI) cancers in particular, our surgeons have been cautious because of the high frequency of skip metastasis and the complicated lymphatic system in the GI tract. We would like to emphasize that so-called skip metastasis has been defined according to anatomic classification of regional lymph nodes and that the lymphatic drainage route must be patient or lesion specific. To test the validity and feasibility of this concept in GI cancers, we have established a radio-guided intraoperative sentinel node navigation system using preoperative endoscopic submucosal injection of radioactive tracer followed by intra-operative gamma-probing. In 131 patients with GI cancers (esophagus: 22, stomach: 71, colorectum: 38), the detection rate of sentinel nades was 91% and overall diagnostic accuracy of lymph node metastasis by sentinel node status was 97%. Initial results suggest further investigation of this procedure as an accurate staging and a minimally invasive approach to early GI cancers.

Gastrointestinal Neoplasms↗
PubMed2000

[Laparoscopic surgery for esophageal achalasia].

Laparoscopic surgery for esophageal achalasia was first reported by Shimi et al. in 1991. Subsequently the procedure has been performed all over the world and laparoscopic Heller myotomy and Dor fundoplication (Heller and Dor operation) is now thought to be the operation of first choice. It is indicated for patients who are resistant to medical therapy (calcium blocker etc.) or have pneumatic dilatation and those with frequent aspiration at night. As Csendes et al. reported that surgical treatment was better than pneumatic dilatation and as laparoscopic surgery is less invasive, the indications for the laparoscopic Heller and Dor operation can include all achalasia patients except those who respond to medical therapy, do not accept surgery, or cannot tolerate surgery. We successfully performed the laparoscopic Heller and Dor operation on 22 patients, all of whom had an uneventful postoperative course. Manometric evaluation, endoscopic examination, and 24-hour pH monitoring showed good results. There are six important technical points: 1) flexible laparoscopy; 2) pneumoperitoneum; 3) gauze in the abdominal cavity to absorb blood; 4) laparosonic coagulating shears; 5) extracorporeal knot-tying technique; and 6) intracorporeal knot-tying technique. If an experienced surgeon is in charge, the laparoscopic Heller and Dor operation is an ideal, minimally invasive treatment for esophageal achalasia.

Esophageal Achalasia↗
PubMed2000

Activated factor XII levels are dependent on factor XII 46C/T genotypes and factor XII zymogen levels, and are associated with vascular risk factors in patients and healthy subjects.

Coagulation factor XII (FXII) is activated on contact with various biologic surfaces, including subendothelial tissues and lipoprotein particles. Thus, the plasma level of activated FXII (XIIa) might represent vascular lesions or be a marker of abnormal lipid metabolism. A 46C/T polymorphism was recently described in the FXII gene close to the ATG translation initiation codon, which was associated with inter-individual variation of plasma FXII zymogen levels. The present paper reports the association of the 46C/T polymorphism with plasma XIIa levels in apparently healthy subjects, and in patients with ischemic cerebrovascular disease (CVD) and arteriosclerosis obliterans (ASO). XIIa levels were not significantly different between patients and controls, but were strongly dependent on XII 46C/T genotypes (2.07 +/- 0.81, 1.65 +/- 0.63, and 0.93 +/- 0.41 ng/ml for C/C, C/T, and T/T genotypes, respectively; P < 0.0001). This association was evident for each group studied (P < 0.0001 for CVD and controls; P= 0.0007 for ASO). There were positive correlations between plasma FXII clotting activity and XIIa levels. In a univariate analysis, XIIa correlated with total cholesterol, triglycerides, plasminogen activator inhibitor-1, and C-reactive protein (CRP), although the presence of conventional cardiovascular risk factors (male sex, smoking, hypertension, hypercholesterolemia, diabetes) did not significantly increase XIIa. Stepwise regression analyses revealed that the XII clotting activity had the strongest association with XIIa. In conclusion, XIIa levels depended on XII 46C/T genotype and correlated with some cardiovascular risk factors. Thus, the FXII genotype should be taken into consideration for interpretation of plasma XIIa levels.

Aged↗
PubMed2000

Scarless endoscopic thyroidectomy: breast approach for better cosmesis.

An original technique for performing endoscopic thyroidectomy using a breast approach to avoid an operative scar in the neck was developed. The subcutaneous space in the breast area and the subplatysmal space in the neck were bluntly dissected through a 15-mm incision between the nipples, and CO2 was insufflated at 6 mm Hg to create the operative space. Three trocars were inserted at the breast, and dissection of the thyroid and division of the thyroid vessels and parenchyma were performed endoscopically using an ultrasonically activated scalpel. Four hemithyroidectomies and one partial resection of the thyroid for five female patients with thyroid adenomas 5 to 7 cm in diameter were successfully performed using this procedure. There were no conversions to open surgery or complications. No scars were apparent in the neck, and all patients were fully satisfied with the cosmetic results. Endoscopic thyroidectomy using a breast approach and low-pressure subcutaneous CO2 insufflation is a feasible and safe procedure, which results in satisfactory cosmetic results.

Adenoma↗
PubMed2000

Laparoscopic wedge resection of gastric submucosal tumors.

Minimally invasive surgery has revolutionized the treatment of gastrointestinal tumors. Submucosal tumors (SMTs) of the stomach can be resected using laparoscopic techniques. Between 1993 and 1997, laparoscopic wedge resection was performed in 34 patients with an SMT of the stomach. The tumors ranged from 8 to 60 mm in diameter. All surgical margins were clear. The average operative time was 131 minutes. Most of the patients began eating on the first postoperative day and were discharged within 5 to 7 days. Histopathologic examination of the tumors showed gastrointestinal stromal tumor (n = 14), ectopic pancreas (n = 7), leiomyosarcoma (n = 4), schwannoma (n = 3), carcinoid (n = 2), leiomyoma (n = 2), an inflammatory lesion caused by parasites (n = 1), and cyst (n = 1). No recurrences were observed over the 5-year follow-up period. A solid SMT of the stomach larger than 20 mm in diameter can be treated using laparoscopic wedge resection.

Adult↗
PubMed2000

[Three-dimensional cholangiography and angiography for hilar cholangiocarcinoma].

Cholangiography is the most fundamental and reliable examination for diagnosis of the extent of bile duct carcinoma. Hepatic angiography is also informative for diagnosis of vascular invasion. However, an accurate understanding of three-dimensional biliary and vascular anatomy at the hepatic hilum is not easily gained by conventional cholangiography and angiography. We have performed three-dimensional cholangiography and angiography (3D-CG & AG) using rotational DSA (Advantx ACT) and a 3D spinning digital imaging system in 29 patients with hilar cholangiocarcinoma, etc. 3D-CG & AD provides clear three-dimensional visualization of the biliary tract and blood vessels affected by bile duct cancer, and useful information on optimal resection. Of 13 patients with hilar cholangiocarcinoma undergoing resection, curative resection was carried out in 11 (85%). 3D-CG & AG is considered to be an indispensable imaging modality for evaluation of the extent and staging of hilar cholangiocarcinoma.

Angiography↗
PubMed2000

[Dynamic MRI and tumor angiogenesis of breast cancer].

The purpose of this study was to clarify the mechanism underlying early enhanced MR images of breast cancer by dynamic MR imaging from the aspect of tumor angiogenesis. The images depicted by dynamic MR imaging of breast cancer were divided into the following two groups: a marginal strong enhancement (MSE) pattern and a variable pattern without marginal strong enhancement (non-MSE). Twenty patients with invasive ductal carcinoma (maximum diameter < 2 cm) were examined by dynamic MR imaging, and the histological materials were submitted to two-dimensional computer image analysis with immunohistochemistry and histochemistry; morphological microvessel characteristics and microvessel density were examined; and the expression of vascular endothelial growth factor (VEGF) was investigated. In the MSE cases, vessel wall irregularity of capillaries and venules in the peripheral area adjacent to the tumor correlated (p < 0.001) with the enhancement pattern, and the total microvessel density (especially of arterioles with a maximum diameter less than 50 microns) of the peripheral area adjacent to the tumor was significantly higher than that of the tumor area. However, in the non-MSE cases, total microvessel density showed no significant difference between the peripheral area adjacent to the tumor and the tumor area, whereas the capillary density of the tumor area was four times greater than that of the peripheral area adjacent to the tumor. The expression of VEGF was strongly positive for the tumor nest adjacent to the capillaries. These results suggest that the enhanced images of the MSE pattern depend on abundant blood supply from arterioles and that the images of the non-MSE pattern might be reflective of angiogenic activity including variable VEGF expression of tumor cells. Thus the mechanism underlying early dynamic MR images of breast cancer was a complex result of tumor angiogenesis and the microcirculatory environment.

Adolescent↗
PubMed2000

[Chemo/endocrine therapy for breast cancer patients].

Standard adjuvant chemo/endocrine therapy for breast cancer patient is based upon St. Gallen's consensus 1998. Recent development in the field of adjuvant chemo/endocrine therapy is an usage of LH-RH analogue with tamoxifen for premenopausal hormone receptor positive women, and also an emerging role of taxans. Orally given 5-FU derivatives may work in adjuvant settings. The third generation aromatase inhibitors have established their role in second line hormone therapy for the advanced or recurrent breast cancer patients. High dose chemotherapy should not be used in outside clinical trials.

Anastrozole↗
PubMed2000

[Sensitivity of UCN-01 lies in the balance of CDK 2 kinase and p21].

Five human cancer cell lines (MKN 45, HT-29, WiDr, PAN-3-JCK, and CRL 1420) were used to evaluate the antitumor spectrum of UCN-01, which suppressed the growth of these digestive cancer cell lines. A human pancreatic cancer xenograft (CRL 1420) and breast cancer xenograft (MX-1) were used to determine their sensitivity to UCN-01, in nude mice. UCN-01 significantly suppressed the tumor growth of CRL 1420 at a dose of 10 mg/kg in a schedule of (qd x 5) x 2, but was ineffective for MX-1. While p21 protein expression was induced by UCN-01 in both CRL 1420 and MX-1, an accumulation of dephosphorylated ppRb was observed only in CRL 1420, resulting in G1 block as detected by flow cytometric analysis. The CDK 2 activity of MX-1 was almost 6 times higher than that of CRL 1420, which might account for the resistance of MX-1 to UCN-01 in spite of the induction of p21 in this strain. We conclude that the determinant of sensitivity to UCN-01 lies in the balance of CDK 2 kinase activity and p21 protein induction.

Alkaloids↗
PubMed2000

[Curative laparoscopic surgery for early gastric cancer: eight years experience].

We have applied two different laparoscopic surgical techniques for early gastric cancer and have successfully treated 111 patients since March 1992. The indications are: 1) preoperative diagnosis of mucosal cancer; 2) lesion size of < 25 mm if the protruding type; and 3) lesion size < 15 mm and UI (-) if the depressed type. The first technique is laparoscopic wedge resection of the stomach using a lesion-lifting method (n = 93). The gastric wall around the cancerous lesion is exposed laparoscopically. The abdominal wall and gastric wall in the vicinity of the lesion are pierced using a 12-G sheathed needle. A small metal rod with a fine wire is introduced into the stomach through the outer sheath. By retracting the metal rod, the lesion can be lifted precisely (i.e., lesion-lifting method). Wedge resection at a sufficient distance from the metal rod is carried out using an endoscopic stapler. The second technique is referred to as laparoscopic intragastric mucosal resection (n = 18). Three balloon trocars are placed in the stomach laparoscopically. The stomach is then insufflated with CO2, and surgical instruments are introduced. The mucosal and submucosal layers around the lesion are resected with sufficient surgical margins. The selection of the laparoscopic technique depends on the site of the cancerous lesion. In our series of 111 patients, sufficient horizontal (mean 15 +/- 5 mm and 8 +/- 4 mm, respectively, using the first and second technique) and vertical surgical margins were achieved. There was no mortality and no major complications in patients undergoing either surgical technique. There have been two recurrences, both mucosal lesions found 2 years after the initial surgery, which were successfully treated with gastrectomy and laser irradiation. All patients have survived for 3 to 96 months, and there has been no trocar site recurrence. In conclusion, these laparoscopic procedures are curative and minimally invasive treatments for early gastric cancer.

Gastric Mucosa↗
PubMed2000

Laparoscopic-assisted hepatectomy (LAH) for the treatment of hepatocellular carcinoma.

The treatment of hepatocellular carcinoma associated with liver cirrhosis necessitates local therapy in some patients because of severe hepatic dysfunction. Percutaneous ethanol injection therapy, the local therapy for such cancer of the liver, and percutaneous microwave coagulation therapy are detailed. The significant disadvantages of these procedures is their inability to evaluate precisely whether the tumor will develop complete necrosis after treatment because the cancer tissue cannot be excised with use of these procedures. Conversely, laparoscopic hepatectomy, which is minimally invasive surgery, has a disadvantage, that is, its difficulty in complex maneuvers, including hemostasis, ligation, and suture. The authors developed laparoscopic-assisted hepatectomy, which is hepatectomy by small incision during laparotomy with the use of laparoscopic observation. This report describes laparoscopic-assisted hepatectomy, which may allow the solving of problems with percutaneous ethanol injection therapy, percutaneous microwave coagulation therapy, and laparoscopic hepatectomy.

Aged↗
PubMed1999

Induction of heme oxygenase-1 suppresses venular leukocyte adhesion elicited by oxidative stress: role of bilirubin generated by the enzyme.

This study aimed to examine whether an elevated activity of heme oxygenase (HO)-1 in the tissue attenuates endothelial cell-leukocyte interactions microvessels in vivo. When rats were pretreated with an intraperitoneal injection of hemin, an HO-1 inducer, mesenteric tissues, including their microvessels, displayed a marked induction of HO-1 concurrent with an increase in plasma concentrations of bilirubin-IXalpha, the product of HO-catalyzed degradation of protoheme IX. In these rats, oxidative stress such as superfusion with H(2)O(2) and ischemia-reperfusion of the tissues neither induced rolling nor exhibited adherent responses of leukocytes in venules. In contrast, the oxidative stresses evoked marked rolling and adhesion of leukocytes in the control rats without HO-1 induction. The HO-1 induction also downregulated leukocyte adhesion elicited by other pro-oxidant stimuli such as N(omega)-nitro-L-arginine methyl ester. The decreases in the oxidant-elicited leukocyte adhesive responses under HO-1-inducing conditions were restored by perfusion with zinc protoporphyrin-IX, an HO inhibitor, but not with copper protoporphyrin-IX, which did not inhibit the enzyme. Furthermore, the effects of zinc protoporphyrin-IX were repressed by superfusion with bilirubin or biliverdin at the micromolar level, but not by the same concentration of carbon monoxide, another product of HO. These results indicate that induction of the HO-1 activity serves as a potential stratagem to prevent oxidant-induced microvascular leukocyte adhesion through the action of bilirubin, a product of HO reaction.

Animals↗
PubMed1999

An interaction between human colon carcinoma cells and hepatocytes activates transforming growth factor-beta1 in vitro.

We established in vitro heterotypic co-cultures of a human colon carcinoma cell line, HT-29, and a human hepatocyte line, tPH5CH, using transwells to investigate possible interactions between colon carcinoma cells and hepatocytes during the metastatic process. Co-culture, but not HT-29 conditioned medium, inhibited tPH5CH cell proliferation, and this inhibition was blocked by an anti-TGF-beta1 antibody. Significantly more activated TGF-beta1 was released by co-culture than by each cell line cultured alone, whereas there were no significant differences between the total TGF-beta1 released by the individual cultured cell lines and that released by co-culture. These data indicate that an interaction between human colon carcinoma cells and hepatocytes activates TGF-beta1 in vitro.

Carcinoma↗
PubMed1999

Cloning, expression, and characterization of a novel UDP-galactose:beta-N-acetylglucosamine beta1,3-galactosyltransferase (beta3Gal-T5) responsible for synthesis of type 1 chain in colorectal and pancreatic epithelia and tumor cells derived therefrom.

The sialyl Lewis a antigen is a well known tumor marker, CA19-9, which is frequently elevated in the serum in gastrointestinal and pancreatic cancers. UDP-galactose:N-acetylglucosamine beta1, 3-galactosyltransferase(s) (beta3Gal-Ts) are required for the synthesis of the sialyl Lewis a epitope. In the present study, a novel beta3Gal-T, named beta3Gal-T5, was isolated from a Colo205 cDNA library using a degenerate primer strategy based on the amino acid sequences of the four human beta3Gal-T genes cloned to date. Transfection experiments demonstrated that HCT-15 cells transfected with the beta3Gal-T5 gene expressed all the type 1 Lewis antigens. In gastrointestinal and pancreatic cancer cell lines, the amounts of beta3Gal-T5 transcripts were quite well correlated with the amounts of the sialyl Lewis a antigens. The beta1,3Gal-T activity toward agalacto-lacto-N-neotetraose was also well correlated with the amounts of beta3Gal-T5 transcripts in a series of cultured cancer cells, and in Namalwa and HCT-15 cells transfected with the beta3Gal-T5 gene. Thus, the beta3Gal-T5 gene is the most probable candidate responsible for the synthesis of the type 1 Lewis antigens in gastrointestinal and pancreatic epithelia and tumor cells derived therefrom. In addition, beta3Gal-T5 is a key enzyme that determines the amounts of the type 1 Lewis antigens including the sialyl Lewis a antigen.

Amino Acid Sequence↗
PubMed1999

Biochemical characterization and functional analysis of two type II classic cadherins, cadherin-6 and -14, and comparison with E-cadherin.

Classic cadherins can be grouped based on their deduced primary structures. Among them the type I cadherins have been well characterized; however, little is known about non-type I cadherins. In this study we characterized two human type II cadherins, cadherin-6 and cadherin-14, using a cDNA transfection system. They were each detected as two bands electrophoretically, were expressed on the external cell surface at cell-cell contact sites, and were associated with caten- ins. Direct sequencing of the N-terminal amino acids showed that the two bands of cadherin-14 corresponded to precursor and mature forms, whereas the two bands of cadherin-6 both had the N-terminal sequence of the mature form. Unlike type I cadherins, both cadherin-6 and -14 were not protected from trypsin degradation by Ca2+. We evaluated their adhesive functions by a long term cell aggregation method. The results suggest that both cadherin-6 and -14 have cell-cell binding strengths virtually equivalent to that of E-cadherin and that their binding specificities are distinct from that of E-cadherin. Cadherin-6 and -14 interacted with each other in an incomplete manner. They have a QAI tripeptide in the first extracellular subdomain instead of the HAV motif that is characteristic of type I cadherins and is intimately involved in the adhesive function. The QAI tripeptide, however, appeared not to be involved in the adhesive functions of cadherin-6 and -14.

Amino Acid Sequence↗