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Biomedical subjects

Makoto Hashizume

Publications and source records attributed to Makoto Hashizume.

At least 37 records · Page 2Linked to original sources
PubMed2003

Abnormal PTEN expression in portal hypertensive gastric mucosa: a key to impaired PI 3-kinase/Akt activation and delayed injury healing?

Phosphatase and tensin homologue deleted on chromosome ten (PTEN) is a dual-specificity phosphatase that has activity toward both phosphorylated peptides and phospholipids. PTEN inhibits activation of Akt, the downstream effector of PI 3-kinase, which is integral to cell proliferation, migration, survival, and angiogenesis essential for tissue injury healing. PTEN expression and activation during injury healing remain unexplored. Portal hypertensive (PHT) gastric mucosa has impaired injury healing, but the underlying mechanisms remain unknown. We investigated whether impaired healing of injured PHT gastric mucosa is due to abnormal PTEN expression/activation that leads to decreased Akt activation. We also investigated the possible involvement of Egr-1, which regulates PTEN in some cells (e.g., fetal kidney epithelial cells), and TNF-alpha, which can induce Egr-1 expression. In PHT gastric mucosa 6 h after injury, PTEN protein levels were increased by 2.7-fold; unphosphorylated PTEN (reflecting activated PTEN) was increased by 2.4-fold; Akt phosphorylation (reflecting Akt activation) was reduced by 2-fold; and Egr-1 expression was increased by 3.3-fold vs. normal gastric mucosa. TNF-alpha neutralization reversed all of the above abnormalities in PHT gastric mucosa, reduced mucosal injury, and enhanced healing. We conclude that, in injured PHT gastric mucosa, overexpressed/activated PTEN leads to the reduced activation of the PI 3-kinase/Akt pathway that results in impaired injury healing.

Animals↗
PubMed2003

Accurate preoperative estimation of liver-graft volumetry using three-dimensional computed tomography.

BACKGROUND: The aim of this study was to clarify the value of three-dimensional computed-tomography (3D-CT) volumetry for size matching in living-donor liver transplantation (LDLT). METHODS: 3D-CT volumetry was applied to 25 donors who underwent hepatectomy for a living relative needing an orthotopic liver transplantation. Fifteen patients underwent extended left lobectomy, one patient an extended left lateral lobectomy, and nine patients right lobectomy. 3D-CT imaging was performed with the workstation ZIO M900 (Zio Software Inc., Tokyo, Japan). The estimated volume of the grafts in two-dimensional (2D) and 3D images were compared, and an error ratio was calculated. RESULTS: 3D-CT imaging revealed the anatomy of the hepatic vein bifurcation and the shape of the graft. The error ratio was 12.8+/-2.3% in 3D, compared with 19.4+/-2.5% in 2D. As such, 3D-CT volumetry appears to be more exact than conventional 2D-CT volumetry, but volumetry by 3D-CT still produces an error ratio of approximately 13%. The weight transition of the rats' livers under preservation in University of Wisconsin (UW) solution indicated that the graft volume seems to decrease during perfusion with UW solution. Mismatch of the cutting line and volume reduction by dehydration (approximately 5% reduction 1 hour after perfusion) seems to cause the error in 3D-CT volumetry. CONCLUSIONS: Three-dimensional CT volumetry is useful for size matching in cases of living-related orthotopic liver transplantation.

Adult↗
PubMed2003

Robot-assisted gastric surgery.

In conclusion, robot-assisted gastric surgery is now considered to be feasible in patients with Stage IA (T1N0) and Stage IB (T1N1, T2N0) early gastric cancer. The optimal treatment modalities have yet to be identified, however, and therefore clinical trials are called for. The authors believe that this new technology will markedly increase the survival rate of such patients all over the world in the near future, while also helping to significantly decrease the complication rates and hospital stay of the patients, which will thus result in a major beneficial socioeconomic impact.

Endoscopy↗
PubMed2003

A robotic surgery system (da Vinci) with image guided function--system architecture and cholecystectomy application.

We have developed a data fusion system for the robotics surgery system "da Vinci". The data fusion system is composed of an optical 3D location sensor and a digital video processing system. The 3D location sensor is attached to the da Vinci's laparoscope and measures its location and direction. The digital video processing system captures the laparoscope's view and superimposes 3D patient's organ models onto the captured view in real-time. We applied the system to "da Vinci" and examined this system during a cholecystectomy. In this experiment, the surgeon was able to observe the inner conditions of the organs with a stereo view.

Cholecystectomy↗
PubMed2002

Anatomic resection for severe blunt liver trauma in 100 patients: significant differences between young and elderly.

The liver is the organ most commonly injured during blunt abdominal trauma. As our society ages, emergency surgery for active elderly patients increases, but data on aggressive emergency hepatic resection remain scarce in the literature. The purpose of this study was to determine whether the elderly (70 years of age or older) can tolerate major liver injury and subsequent hepatic resection. We investigated 100 patients who were treated by an anatomic resection for severe blunt liver trauma (29 elderly patients who were 70 years of age or older and 71 young patients who were younger than 70 years of age) in a retrospective study. The elderly patients were more severely injured as demonstrated by a higher Injury Severity Score, a lower Glascow Coma Scale, and lower survival (80.3% vs. 65.5%; p < 0.05). The total number of associated injuries was greater in elderly patients. Motor vehicle accidents were responsible for 71.8% of the injuries in the young group, and the predominant mechanism in the elderly patients was also motor vehicle accidents (51.7%). The 71 anatomic hepatic resections performed on the young patients included right hemihepatectomy (n = 45), left lateral segment resection (n = 14), bisegmentectomy (n = 5), and others. The 29 anatomic hepatic resections performed for the elderly patients were right hemihepatectomy (n = 15), left lateral segment resection (n = 5), left hemihepatectomy (n = 4), and others. Pneumonia, subphrenic abscess, and urosepsis occurred at a significantly higher frequency in elderly patients than in young patients. Our data clearly indicated that (1) the mechanism of injury, grade of associated intraabdominal injuries, distribution of surgical procedures, and complications differ significantly between young and elderly patients; and (2) the survival rate (65.5%) in elderly patients may be sufficient to consider anatomic hepatic resection to be a useful, safe procedure.

Accidents, Traffic↗
PubMed2002

Video-assisted thoracoscopic extirpation of a posterior mediastinal mass using the da Vinci computer enhanced surgical system.

A 28-year-old woman presented a left posterior mediastinal mass surrounded by the intercostal vein, hemiazygos vein, sympathetic nerve, and descending aorta. We successfully resected the mass, that was revealed to be a bronchogenic cyst, by a totally thoracoscopic procedure using the da Vinci computer-enhanced system (Intutive Surgical, Mountain View, CA) without injuring the neighboring structures or the capsule of the mass.

Adult↗
PubMed2002

Effects of splenectomy on liver volume and prognosis of cirrhosis in patients with esophageal varices.

BACKGROUND: Several previous studies have shown that hepatic regeneration after partial hepatic resection accelerates over time once a splenectomy has been performed. This was a retrospective study investigating whether a splenectomy has some beneficial effects for cirrhotic patients with esophageal varices. METHODS: Ninety-three patients underwent either esophageal transection, including splenectomy (splenectomy group), or endoscopic injection sclerotherapy (controls) for esophageal varices. No patient had hepatocellular carcinoma and the grades of their hepatic function were from mild to moderate. The changes in hepatic and splenic functions and liver volume were evaluated, as well as the probability of survival. RESULTS AND CONCLUSIONS: Both plasma white blood cell and platelet counts significantly increased in the splenectomy group compared to the controls (P < 0.05). The proportion of liver volume 1 year after the treatments compared to the volume before the treatments (which was 100%) was 96.4% in splenectomy group and 94.4% in controls. No patient had serious complications, such as severe infection caused by the splenectomy. The two groups showed no statistically significant differences in survival rates throughout this study. Although hypersplenism significantly was improved by splenectomy, no difference in changes in liver volume nor survival probability between the two groups was found. Further studies, such as those with a large number of patients, long-term volumetric analysis, or histopathological examination, are needed to clarify fully the effects of splenectomy on cirrhotic patients.

Adult↗
PubMed2002

Role of the spleen in liver fibrosis in rats may be mediated by transforming growth factor beta-1.

BACKGROUND: The effect of the spleen on the cirrhotic liver is unknown. Transforming growth factor-beta 1 (TGF-beta 1), which plays a crucial role in the matrix production during liver fibrosis, is an inhibitory factor regarding the regeneration of hepatocytes. In this study, we investigated the TGF-beta 1 production in the spleen of cirrhotic rats and the effects of a splenectomy on the healing process from liver fibrosis. METHODS: Thirty-six Wistar male rats were used. Thioacetamide (TAA) was administered intraperitoneally for 24 weeks. The rats underwent either a sham operation (TAA + Sham) or a splenectomy (TAA + SPL). The improvements in liver fibrosis and liver regeneration were investigated 10, 30 and 60 days after the operations in each group. The effect of a splenectomy on the plasma concentration of TGF-beta 1 in the portal vein was investigated by ELISA. The TGF-beta 1 expressions in the spleen were measured using immunohistochemical staining and the degree of such expression was measured using RT-PCR. The activity of TGF-beta 1 in the portal vein of TAA + Sham and TAA + SPL was assessed by the inhibiting effect of rat parenchymal hepatocyte proliferation in primary culture. RESULTS: Liver regeneration (PCNA-labeling index) in the TAA + SPL rats was stimulated more at 10 and 30 days after the operation (P < 0.05) than in the TAA + Sham rats, and the improvement of liver fibrosis (fibrosis rate) in the TAA + SPL rats was higher at 60 days (P < 0.05) than in the TAA + Sham rats. The plasma concentration of TGF-beta1 of the portal vein in TAA + SPL rats was significantly lower than in the TAA + Sham rats for each period. Immunohistochemically, TGF-beta1-positive stained cells were recognized in the spleen macrophages in the red pulp of cirrhotic rats. The plasma of the TAA + Sham rats at 10 and 30 days after the operation was significantly stronger than that of the TAA + SPL rats in inhibiting the proliferation of rat hepatocytes of primary culture. Inhibitory effects were then dose-dependently neutralized by monoclonal TGF-beta 1 antibody. CONCLUSION: Spleen-derived TGF-beta 1 may thus play an inhibitory role in the healing of liver cirrhosis by inhibiting the regeneration of the damaged liver.

Animals↗
PubMed2002

Endoscopic injection sclerotherapy in the management of 2105 patients with esophageal varices.

BACKGROUND: The objective of this study is to examine the overall clinical results of endoscopic injection sclerotherapy (EIS) for patients with esophageal varices in our institution. METHODS: From January 1982 to May 2001, 2105 patients with esophageal varices were treated with EIS, which included prophylactic injections for patients with risky varices according to our criteria. Follow-up endoscopy was performed every 3 months, and recurrent varices were treated with additional EIS. RESULTS: Acute variceal bleeding was controlled in 468 of 473 patients (98.9%). Esophageal varices were completely eradicated in 1757 of 2105 patients (83.5%) with 3.8 +/- 1.6 sessions of EIS. The cumulative recurrence rates were 32.2% at 5 years, 36.5% at 10 years, and 37.8% at 15 years. The cumulative nonbleeding rates were 92.3% at 5 years, 90.1% at 10 years, and 89.5% at 15 years. The survival rate of acute bleeders was significantly lower than for both elective and prophylactic cases (P <.05). The overall cumulative survival rate was 28.2% at 10 years. CONCLUSIONS: EIS is the first choice of treatment for esophageal variceal bleeding, and rebleeding was shown to be well controlled in a long-term follow-up with endoscopy and additional EIS. The lower survival rate observed in acute bleeders may therefore justify the use of prophylactic EIS.

Acute Disease↗
PubMed2002

Long-term results of endoscopic Histoacryl injection sclerotherapy for gastric variceal bleeding: a 10-year experience.

BACKGROUND: The long-term efficacy and safety of endoscopic injection of N-butyl-2-cyanoacrylate (Histoacryl) were evaluated as the initial treatment for bleeding gastric varices. PATIENTS AND METHODS: Fifty-two patients with bleeding gastric varices underwent endoscopic injections of Histoacryl for hemostasis over a 10-year period. Histoacryl was injected intravariceally. Among these 52 patients, 32 had active bleeding and 20 had recent bleeding. Most of the varices were large (F2 or F3, 48 cases). After Histoacryl injection, the patients were followed endoscopically with retreatment administered as necessary. The patients were followed for a mean 28.1 months. RESULTS: The rate of initial hemostasis (no bleeding occurred for 48 hours after sclerotherapy) was 96.2%. Cumulative nonbleeding rates were 64.7%, 52.7%, and 48.2% at 1, 5, and 10 years, respectively. When rebleeding occurred, 80.0% was within 1 year after initial injection. Recurrent bleeding was easily stopped with the reinjection of Histoacryl in most patients. The treatment failure-related mortality rate was 4.0% (2 of 52). The cumulative survival rates were 66.9%, 60.4%, and 55.5% at 1, 5, and 10 years, respectively. The mortality depended on either malignancy or liver function (Child-Pugh classification). CONCLUSIONS: These results suggest that Histoacryl injection sclerotherapy is highly effective for the treatment of bleeding gastric varices, with rare complications occurring both acutely and long-term. Therefore, Histoacryl injection sclerotherapy is considered to be the first choice of treatment for bleeding gastric varices, but the rate of recurrent bleeding is so high that further methods or devices still need to be developed in order to prevent gastric variceal rebleeding.

Adolescent↗
PubMed2002

A new era of robotic surgery assisted by a computer-enhanced surgical system.

Computer-enhanced robotic surgery has now been introduced into general surgical practice. The robotic system enables us to manipulate endoscopic instruments, as well as instruments during open surgical intervention, regarding both the operative field and operation techniques. This technologic innovation should therefore help surgeons overcome various difficulties and allow them to perform more precise, safer, and more minimally invasive surgery in the coming era.

General Surgery↗
PubMed2002

Early results of an endoscope-assisted subcutaneous mastectomy and reconstruction for breast cancer.

BACKGROUND: Subcutaneous mastectomy and reconstruction (SMR) is well established; however, most incisions are made directly on the breast, and the majority of patients care about visible scars even if they are satisfied with the reconstructed breast. METHODS: From August 1998 to March 2001, a total of 46 patients (including 2 bilateral cases) with breast cancer underwent SMR using a saline-filled prosthesis by lateral axillary incision. There were 25 patients who received previous SMR without endoscopic assistance (group A) and 21 patients who underwent an endoscope-assisted SMR (E-SMR) (group B). These 2 groups were compared for curability, morbidity, and cosmesis. RESULTS: The median follow-up period was 19.2 + 9.8 months (range, 5.8 - 35.2 months). No significant difference was found in clinicopathologic data between the 2 groups. The operation time was 176 minutes in group A and 237 minutes in group B, and the estimated blood loss was 189 mL vs 356 mL, respectively. No critical complications were seen in either group. The average length of incision was 10 cm in group A and 5.7 cm in group B. As for the patients' satisfaction, the incidence of "excellent" plus "good" ratings was 76% in group A and 90.4% in group B. CONCLUSIONS: E-SMR is a new option that can provide an improved operative view and better cosmetic results for the treatment of breast cancer than with SMR. The operation time is longer than for SMR, but the incision is drastically shorter, resulting in better cosmesis and increased patient satisfaction.

Adult↗
PubMed2002

Laparoscopic splenectomy for hematologic diseases.

BACKGROUND: Laparoscopic splenectomy has been demonstrated to be technically feasible and safe for the treatment of hematologic diseases. METHODS: The study comprised 64 consecutive patients with chronic immune thrombocytopenia purpura (ITP) who were admitted to our hospital from 1992 to 2000 and underwent laparoscopic splenectomy. Forty-one consecutive patients with ITP who underwent open splenectomy performed at the same hospital by the same surgical team between 1986 and 2000 were selected as the control group. RESULTS: We performed laparoscopic splenectomies for ITP, hereditary spherocytosis (HS), malignant lymphoma, autoimmune hemolytic anemia, and cryoglobulinemia. Laparoscopic surgery as compared with open surgery in ITP revealed a significantly lower pain medication requirement, an earlier resumption of oral intake, and a shorter hospital stay, but a longer operative time. During the present study (range: 3.8-80 months), the cumulative rate of nonrecurrence was 67.9% at 5 years after surgery, which was similar to the rate for the previous open splenectomy. CONCLUSIONS: Laparoscopic splenectomy is considered to be a suitable alternative therapeutic modality in the treatment of hematologic diseases.

Anemia, Hemolytic↗
PubMed2002

Sevoflurane and bradykinin-induced calcium mobilization in pulmonary arterial valvular endothelial cells in situ: sevoflurane stimulates plasmalemmal calcium influx into endothelial cells.

Kinins locally synthesized in the cardiovascular tissue are believed to contribute to the regulation of cardiovascular homeostasis by stimulating the endothelial cells to release nitric oxide, prostacyclin, or a hyperpolarizing factor via autocrine-paracrine mechanisms. This study was designed to investigate the action of sevoflurane on bradykinin-induced Ca2+ mobilization in endothelial cells in situ. Utilizing fura-2-loaded rat pulmonary arterial valve leaflets, the effects of sevoflurane were examined on bradykinin-induced increases in intracellular Ca2+ concentration ([Ca2+]i) in endothelial cells in situ. In the presence of extracellular Ca2+ (1.5 mM), bradykinin (3-30 microM) produced an initial phasic and a subsequent tonic increase in [Ca2+]i in a concentration-dependent manner. However, it produced only the phasic increase in [Ca2+]i in the absence of extracellular Ca2+. Sevoflurane (5%, 0.67 mM) inhibited both the phasic and tonic responses to bradykinin. In these experiments, sevoflurane (3-5%) generated sustained increases (approximately 20-40% of the bradykinin-induced maximal increase in [Ca2+]i) in the resting [Ca2+]i level. Sevoflurane still increased [Ca2+]i after depletion of the intracellular Ca stores with ionomycin (0.1 microM ). However, the sevoflurane-induced increase in [Ca2+]i was eliminated by removal of the extracellular Ca and attenuated by NiCl (1-3 mM). In conclusion, in the pulmonary arterial valvular endothelial cells, sevoflurane inhibits both bradykinin-induced Ca2+ release from the intracellular stores and bradykinin-induced plasmalemmal Ca2+ influx. In addition, sevoflurane appears to stimulate the plasmalemmal Ca2+ influx and thereby increase the endothelial [Ca2+]i level. Sevoflurane might influence the pulmonary vascular tone through its direct action on the pulmonary arterial valvular endothelial cells.

Anesthetics, Inhalation↗
PubMed2002

[Long-term prognosis and satisfaction after percutaneous endoscopic gastrostomy in a general hospital].

Although percutaneous endoscopic gastrotomy (PEG) has been widely acknowledged as a safer method for enteral feeding, its long-term impact on prognosis and quality of life (QOL) in elderly patients is not sufficiently understood. Regarding the indications of PEG, there still exist issues to be studied due to lack of convincing evidence for reduction of expected complications such as aspiration pneumonia or for improvement of prognosis in patients with severe dementia. In this study we investigated the survival rate after PEG placement and family satisfaction retrospectively in 78 elderly inpatients who underwent PEG, by sending questionnaires to the patients or their caregivers. The results of 68 cases (88%) recovered showed that the 1-year survival rate was 64.0%, and the 2-year survival rate was 55.5%. Fifty-three percent of families of patients showed overall satisfaction regarding the induction of PEG. The survival rate was relatively higher than that from previously reported studies. The differences we observed may be attributed to variations in patients' backgrounds (clinical, socio-economic, cultural) in therapeutic interventions. We recognized the importance of clarifying factors which would affect the prognosis and QOL in elderly patients who undergo PEG. The indication for PEG can be made based on comprehensive assessment of the relevant factors in individual cases, taking patient's or caregiver's wishes into consideration.

Aged↗
PubMed2002

Thoracoscopic treatment of Bochdalek hernia in the adult: report of a case.

Bochdalek hernia is a type of congenital diaphragmatic hernia that mainly occurs in childhood, but is extremely rare in adults. A case report of Bochdalek hernia in a 17-year-old woman, complaining of left lateral upper abdominal pain is herein reported with a brief review of the literature. The herniated organs into the thoracic cavity in this case were the as stomach, large intestine, spleen and greater omentum which was diagnosed using computed tomography, an upper gastrointestinal double contrast study and irrigography. The patient was successfully treated by video-assisted thorachoscopic surgery (VATS) with a pushback method. The post-operating course was uneventful with minimal pain of the surgical wound. This case demonstrated the efficacy of the VATS repair for Bochdalek hernia.

Adolescent↗