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Biomedical subjects

M Niimi

Publications and source records attributed to M Niimi.

At least 19 recordsLinked to original sources
PubMed2003

Vascular anatomy for right colon lymphadenectomy.

Since the superior mesenteric artery (SMA) mostly originates on the left side of the superior mesenteric vein (SMV), the ileocolic artery (ICA) and the right colic artery (RCA) cross the SMV. Understanding the three-dimensional relation of these vessels is important for dissecting these arteries to their origin. Hence, we conducted a study of the vascular anatomy of the right colon in 27 cadavers. The RCA was separate from the SMA in eight cases (30%). The RCA passed the SMV either anteriorly (5 cases, 63%) or posteriorly (3 cases, 38%). In seven (88%) of these eight cases, the ICA was posterior to the SMV. The ICA was identified in all 27 cases, and passed the SMV anteriorly in nine cases (33%) and posteriorly in 18 cases (67%). Thus, the ICA and the RCA may pass on either side of the SMV. The surgeon must dissect the arteries with the SMV, being aware of both possibilities.

Aged↗
PubMed2002

Comparative study of thyroidectomies. Endoscopic surgery versus conventional open surgery.

BACKGROUND: We have performed endoscopic thyroidectomy by an anterior chest approach and by an axillary approach. In this study, we evaluate the efficacy of these two types of endoscopic procedures and conventional open surgery. METHODS: Each procedure was performed in 15 patients. The degree of surgical invasiveness and the nature of patients' complaints after surgery were compared using results of the operation and a questionnaire. RESULTS: Although the mean operating time for the endoscopic procedure was significantly longer than for open surgery, there was no postoperative pain difference in the three groups. Three months after surgery, the incidence of swallowing discomfort was higher in the open surgery group than in endoscopic surgery group. All of the patients treated using the axillary approach were satisfied with the cosmetic results. However, three patients (20%) treated using the anterior chest approach and 11 patients (73%; p < 0.01) who underwent open surgery complained about the cosmetic results. CONCLUSIONS: The incidence of postoperative complaints after endoscopic surgery is significantly lower than after open surgery. Patients treated using the axillary approach can obtain cosmetic results superior to those achieved with other procedures.

Adenoma↗
PubMed2002

Total endoscopic parathyroidectomy.

During the last five years, minimally invasive procedures have been adopted for the surgical treatment of hyperparathyroidism, because preoperative localization studies such as high-resolution ultrasonography and sestamibi scintigraphy, guidance by intraoperative scans, and the use of quick, intraoperative parathyroid hormone assay have improved. Endoscopic parathyroidectomy was performed by Gagner in 1996, and surgical procedures using endoscopy have been devised. The endoscopic procedures range from the "pure" endoscopic approach characterized by constant gas insufflation to video-assisted gasless techniques. We adopted the "pure" endoscopic approach, because a small incision can be made far from the neck and the cosmetic result is excellent. We report our technique with no scars in the neck region for endoscopic unilateral neck exploration with primary hyperparathyroidism and for endoscopic bilateral neck exploration with renal hyperparathyroidism.

Adult↗
PubMed2002

Total endoscopic thyroidectomy: axillary or anterior chest approach.

We have developed endoscopic thyroidectomy by an anterior chest approach and an axillary approach. In this study, we evaluate the efficacy of these two types of endoscopic procedures and conventional open surgery. The degree of surgical invasiveness and the nature of patients' complaints after surgery were compared using the results of the operation and a questionnaire. The mean operating time for the endoscopic procedure was significantly longer than that for open surgery; however, there was no difference in postoperative pain in the three groups. Three months after surgery, the incidence of discomfort while swallowing in open surgery was higher than that in endoscopic surgery. All the patients who were treated using the axillary approach were satisfied with the cosmetic results. However, five patients (25%) who were treated using the anterior chest approach and 15 patients (75%; P < 0.01) who underwent open surgery complained abut the cosmetic results. The incidence of postoperative complaints after endoscopic surgery is significantly lower than that after open surgery. Patients who were treated using the axillary approach can obtain superior cosmetic results, compared with those who received other procedures.

Adult↗
PubMed2002

Laparoscopic partial adrenalectomy.

Since corticosteroids are indispensable hormones, partial or cortical-sparing adrenalectomies may be adopted for the surgical treatment of adrenal diseases. In this article, we describe the technique and results of these procedures. Laparoscopic partial or cortical-sparing adrenalectomy has been performed in 10 patients. Seven cases had an aldosterone-producing adenoma (APA) and three had a pheochromocytoma. Three cases with an APA and a case with a pheochromocytoma had tumors located far from the adrenal central vein, and the vein could be preserved. Four cases with an APA and two with a pheochromocytoma had tumors located close to the adrenal central vein, and it was necessary to section the central vein to resect them. All endoscopic procedures were performed successfully. There were no postoperative complications. At follow-up, adrenal 131I-adosterol scintigrams showed the preservation of remnant adrenal function in all patients. Laparoscopic partial or cortical-sparing adrenal surgery was safely performed, and adrenal function was preserved irrespective of whether the adrenal central vein could be preserved or not. We consider this to be a useful operative technique for selected cases.

Adrenal Gland Neoplasms↗
PubMed2002

Randomized phase II study of biweekly CHOP and dose-escalated CHOP with prophylactic use of lenograstim (glycosylated G-CSF) in aggressive non-Hodgkin's lymphoma: Japan Clinical Oncology Group Study 9505.

BACKGROUND: CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone) is accepted as the best available standard treatment for first-line chemotherapy in aggressive non-Hodgkin's lymphoma (NHL). However, the therapeutic efficacy of CHOP remains unsatisfactory, particularly in high-intermediate risk and high risk patients, and a new strategy is warranted in this patient population. The aim of the present study was to explore a suitable therapeutic-intensified regimen for the treatment of aggressive NHL. PATIENTS AND METHODS: Between May 1995 and July 1998, a total of 70 patients with high-intermediate risk or high risk aggressive NHL, according to the International Prognostic Index, were enrolled and randomly assigned to receive either eight cycles of standard CHOP (cyclophosphamide 750 mg/m(2), doxorubicin 50 mg/m(2), vincristine 1.4 mg/m(2) and prednisolone 100 mg for 5 days) every 2 weeks, or six cycles of dose-escalated CHOP (cyclophosphamide 1500 mg/m(2), doxorubicin 70 mg/m(2), vincristine 1.4 mg/m(2) and prednisolone 100 mg for 5 days) every 3 weeks. Lenograstim (glycosylated rHuG-CSF), at a dose of 2 micro g/kg/day s.c., was administered daily from day 3 until day 13 with biweekly CHOP and until day 20 with the dose-escalated CHOP. The primary endpoint was complete response rate. RESULTS: The complete response rate was 60% [21 of 35; 95% confidence interval (CI) 42% to 76%] with biweekly CHOP and 51% (18 of 35; 95% CI 34% to 69%) with dose-escalated CHOP. The major toxicity was grade 4 neutropenia and was more frequent in the dose-escalated CHOP arm (86%) than in the biweekly CHOP arm (50%). Grade 4 thrombocytopenia was also more frequent in the dose-escalated CHOP arm (20%) than the biweekly CHOP arm (3%). Non-hematological toxicities were acceptable in both arms. One treatment-related death (due to cardiac arrhythmia) was observed in a dose-escalated CHOP patient. Progression-free survival at 3 years was 43% (95% CI 27% to 59%) in the biweekly CHOP arm and 31% (95% CI 16% to 47%) in the dose-escalated CHOP arm. Although seven patients were deemed ineligible by central review of the pathological diagnosis, the results for both eligible and all enrolled patients were similar. CONCLUSIONS: Similar complete response rates and progression-free survival rates, but lower toxicity, indicated that biweekly CHOP was superior to dose-escalated CHOP in the treatment of aggressive NHL. Based on these results, the Lymphoma Study Group of the Japan Clinical Oncology Group is conducting a randomized phase III study comparing biweekly CHOP with standard CHOP in newly diagnosed patients with advanced-stage aggressive NHL.

Adult↗
PubMed2002

The multiple endocrine neoplasia type 1 gene product, menin, inhibits the human prolactin promoter activity.

Menin is a protein encoded by the gene mutated in multiple endocrine neoplasia type 1 (MEN1) characterized by multiple endocrine tumors of the parathyroid glands, pancreatic islets and the anterior pituitary, especially prolactinoma. In this study, we examined the effects of menin on human prolactin (hPRL) expression. In rat pituitary GH3 cells stably expressing menin, both PRL gene expression/secretion and thymidine incorporation into DNA were inhibited as compared with mock-transfected cells. The transcriptional activity of PRL promoter in GH3 cells co-transfected with menin was significantly decreased. A deletion mutation (569 delC), which we identified in a Japanese MEN1 family, was introduced into menin. When GH3 cells were transfected with a mutant menin expression vector, inhibition of hPRL promoter activity was partially reversed. These observations suggest that menin inhibits hPRL promoter activity and cell proliferation, raising the possibility that menin might play an important role in the tumorigenesis of prolactinoma.

Animals↗
PubMed2001

Operational tolerance induced by pretreatment with donor dendritic cells under blockade of CD40 pathway.

BACKGROUND: Dendritic cells can mount immune response as competent antigen presenting cells. Recently, it has been reported that immature dendritic cells induce prolongation of allograft survival. However, the ability of mature dendritic cells to induce operational tolerance is unclear. Therefore, in this study, we examined the ability of splenic mature dendritic cells to induce operational tolerance to fully allogeneic antigens using mouse heterotopic heart transplantation model. METHODS: CBA (H2k) mice received i.v. injections with donor splenic dendritic cells or B cells in the absence or presence of monoclonal antibody (mAb) specific for CD40 ligand or CD80/CD86 2 weeks before transplantation of a C57BL/10 (H2b) heart. RESULTS: When donor dendritic cells were injected i.v. 2 weeks before transplantation, rejection response was accelerated compared with that of naive mice [median survival time (MST) = 7 and 8 days, respectively]. However, when CD40 pathway was blocked by anti-CD40 ligand mAb, i.v. injection of donor dendritic cells but not B cells induced indefinite graft survival (MST >100 and 20 days, respectively). Mice treated with anti-CD40 ligand mAb alone rejected their grafts with a MST of 18 days. Intravenous injection of donor dendritic cells and B cells in combination with anti-CD80/CD86 mAbs was less effective to induce graft prolongation (MST = 9.5 and 13 days, respectively). CONCLUSIONS: Therefore, under blockade of CD40 pathway, mature dendritic cells were tolerogens in vivo independent of CD80/86 pathways.

Adoptive Transfer↗
PubMed2001

Endoscopic total parathyroidectomy by the anterior chest approach for renal hyperparathyroidism.

BACKGROUND: During the past 3 years, minimally invasive procedures have been adopted for the surgical treatment of primary hyperparathyroidism, and we have tried to perform endoscopic total parathyroidectomy for renal hyperparathyroidism. METHODS: Five 5-mm trocars were inserted through the skin of the anterior chest under a general anesthesia. Carbon dioxide was then insufflated up to 4 mmHg, and the endoscopic surgery was performed. RESULTS: Endoscopic procedure was successfully performed in five patients. The mean duration of total parathyroidectomies was 236 min. No evidence of injury to the recurrent laryngeal nerve was observed in any cases. At follow-up, the serum calcium and parathyroid hormone levels had returned to within the normal range in all patients. Postoperative cosmetic status was excellent. CONCLUSION: We believe that endoscopic total parathyroidectomy by the anterior chest approach will find a role in the treatment of renal hyperparathyroidism.

Female↗
PubMed2001

Endoscopic thyroidectomy and parathyroidectomy by the axillary approach. A preliminary report.

BACKGROUND: The use of endoscopic procedures leads to a reduction in the size of the surgical scar, making it more inconspicuous. In this paper, we evaluated the merits and limits of endoscopic neck surgery. METHODS: Between August 1999 and July 2000, 102 patients underwent neck surgery in our department for thyroid or parathyroid disease. Twenty-eight of them were treated by the axillary. A 12-mm and two 5-mm trocars were inserted through the skin of the axilla. Carbon dioxide was then insufflated up to 4 mmHg, and the endoscopic surgery was performed. RESULTS: Endoscopic procedures were performed successfully in 26 cases (19 thyroidectomies and seven parathyroidectomies). There were two conversions to open procedures. The mean operating times for the thyroidectomies and parathyroidectomies were 212 and 171 min, respectively. No evidence of injury to the recurrent laryngeal nerve was observed in any of the cases. The postoperative cosmetic status of the patients was excellent. CONCLUSION: We believe that endoscopic thyroidectomy and parathyroidectomy by the axillary approach will find a role in the treatment of endocrine diseases in the neck.

Adenocarcinoma, Follicular↗
PubMed2001

Superficialization of hemodialysis access using a video-assisted procedure.

Brachiocephalic fistula is one of the main options to gain blood access for hemodialysis. Although the fistula is easy to establish, puncture becomes increasingly difficult because the cephalic vein runs deep and fibrous tissue is being continually deposited over the cephalic vein. Although superficialization-i.e., the removal of fibrous tissue along the basilic vein-has been performed with conventional surgery, the long incision along the cephalic vein induces the buildup of hard fibrous tissue so that puncture may remain difficult even after the operation. To avoid this problem, we tried superficialization of hemodialysis access using a video-assisted procedure and obtained a good result.

Arm↗
PubMed2001

Endoscopic thyroidectomy by the axillary approach.

Neck surgery has recently become one of the newest fields for the application of endoscopic surgery because the resultant scar is small and inconspicuous. Still, some patients feel even a small scar on the neck is not cosmetically acceptable. We therefore have developed a new technique of endoscopic thyroidectomy by the axillary approach that leaves no scar on the neck at all. When this method is used, the small scar in the axilla is completely covered by the patient's arm in a natural manner. The cosmetic result is excellent, and sensory loss in the neck is negligible because the area of surgical dissection is small. We believe that endoscopic thyroid surgery by the axillary approach will find a role in the treatment of thyroid disease.

Axilla↗