Distribution characteristics and its controlling facters of isoprene dissolved in surface seawater in the Southern Ocean

第2回極域科学シンポジウム/第34回気水圏シンポジウム 11月17日（木） 統計数理研究所 セミナー室

Optimum mean ionospheric height in total electron content observations

In order to obtain an accurate TEC (Total Electron Content) from the differential Doppler frequency measurements of two coherent signals transmitted from NNSS (Navy Navigation Satellite System) satellites received at a pair of ground stations, it is necessary to solve an integral constant which depends greatly on the assumed mean ionospheric height h_s. We propose here a novel method which enables us to determine h_s in a reasonable way as follows. By examining the rms sum of the calculated difference of TEC_v\u27s ("composite difference" of the vertically corrected TEC) from six pairs of the four stations, Kokubunji, Sendai, Ebetsu, and Wakkanai, located in the northern part of Japan in the North-South direction, with various assumed h_s values, we select the combinations of neighboring nearest stations, Kokubunji-Sendai and Ebetsu-Wakkanai only, for which we obtain suitable h_s\u27s with which the composite difference takes a single minimum for each pair of the stations. Then, we determine the latitudinal dependence of h_s by least-squares fit to a straight line for these locally deduced values. The mean ionospheric height h_s as a function of latitude thus derived should be optimum. In practice, we examined the data set during the period from November 11 to 18,and from 21 to 25,1994,throughout which magnetic activity remained low with K_p index in the range of 0_+～3_+, and we found 13 events to apply the present method effectively.After showing a possible signature of medium-scale TID (Traveling Ionospheric Disturbance) observed at the time of K_p=4_ on May 4,1994,we give some comments on the observations of the medium-scale TID in the polar region

A case of clear cell adenocarcinoma arising from endometriosis of the rectum treated by laparoscopic surgery

INTRODUCTION: Malignant transformation of intestinal endometriosis occurring in the extraovarian sites is extremely rare. We report a very rare case of clear cell adenocarcinoma arising from endometriosis of the rectum. PRESENTATION OF CASE: An 83-year-old woman was admitted with the complaint of hematochezia. Colonoscopy revealed a tumor around about half of the rectal circumference. Biopsy of the tumor revealed a well-differentiated adenocarcinoma. Low anterior resection was undergone laparoscopically under the diagnosis of rectal carcinoma. Histopathological examination revealed clear cell adenocarcinoma, invading the sub-serosa of the rectum, but no metastasis of the lymph nodes. Immunohistochemical staining showed strong positivity for cytokeratin 7, but no staining for cytokeratin 20 and CDX2. The tumor existed adjacent to the endometrial glands, which were stained positive for Estrogen receptor. Ultimately, the patient was diagnosed with clear cell adenocarcinoma arising from endometriosis. Eighteen months after surgery, there are no signs of tumor recurrence. DISCUSSION: Clear cell adenocarcinoma arising from intestinal endometriosis has been reported in 7 cases, including our case. Careful observation is required because the prognosis of endometriosis after malignant transformation remains poor. CONCLUSION: We report a very rare case of clear cell adenocarcinoma arising from endometriosis of the rectum treated by laparoscopic surgery

Laparoscopic intersphincteric resection using needlescopic instruments

Intersphincteric resection (ISR) is a procedure designed to preserve anal function in cases with very low rectal cancer. We report our clinical experience with laparoscopic ISR (Lap ISR) performed using needlescopic instruments. First, a camera port is created at the umbilicus. Two 5-mm ports are then inserted at the right upper and lower quadrants. Two needlescopic forceps (Endo-Relief™ Hope Denshi Co., Chiba, Japan) are inserted at the left upper and lower quadrants. We then perform the following procedures; ligation of the inferior mesenteric artery and vein, total mesorectal excision and dissection of the intersphincteric space. After the transanal intersphincteric dissection, the specimen is extracted through the anus and a hand -sewn coloanal anastomosis is performed. The covering ileostomy is finally created at the right upper port. We performed Lap ISR using needlescopic forceps in two patients with very low rectal cancer. In both cases, we were able to perform this procedure without insertion of an additional port or to change the needlescopic forceps to conventional 5-mm forceps. Lap ISR with needlescopic instruments is a feasible procedure for minimally invasive surgery

Repeated laparoscopic resection of extra-regional lymph node metastasis after laparoscopic radical resection for rectal cancer

Here, we report a case of repeated laparoscopic resection of extra-regional lymph node metastases in a patient after laparoscopic surgery for rectal cancer. A 72-year-old woman was diagnosed with upper rectal cancer and underwent laparoscopic low anterior resection and D3 dissection. The pathological stage was considered as T3, N2b, M0, Stage IIIC. Six months after the operation, positron emission tomography-computed tomography (PET-CT) showed fluorodeoxyglucose (FDG) accumulation in the infra-renal para-aortic lymph nodes (PALNs). Systemic chemotherapy was administered; however, chemotherapy was discontinued due to hemoptysis related to her pulmonary disease. Therefore, we performed laparoscopic PALN resection. Pathologically, one lymph node was diagnosed with a metastasis. Three months after the second operation, PET-CT identified FDG accumulation in the left lateral pelvic lymph nodes (LPLNs) and a PALN. Laparoscopic LPLN dissection and PALN resection through minilaparotomy were performed. Pathologically, lymph node metastases were diagnosed in both fields. Sixteen months after the 3rd operation, there is no recurrence

A case of total laparoscopic sigmoidectomy involving the use of needle forceps and transanal specimen extraction for sigmoid colon cancer

A 76-year-old male underwent endoscopic mucosal resection for a stage T1 tumour of the sigmoid colon. We performed laparoscopic sigmoidectomy through 5 ports using needlescopic instruments. The resected specimen was extracted from the abdominal cavity transanally. After attaching an anvil to the sigmoidal stump, the rectal stump was reclosed using an endoscopic linear stapler, and then, colorectal anastomosis was conducted using the double stapling technique. Performing transanal specimen extraction using needlescopic forceps improves aesthetic outcomes and reduces post-operative pain and the risk of abdominal incisional hernias. This method is an easy to introduce a form of reduced-port surgery because of its feasibility and conventional port arrangement. Hence, we consider that it is an option for minimally invasive surgery