Measurement and comparison of individual external doses of high-school students living in Japan, France, Poland and Belarus-the 'D-shuttle' project

Twelve high schools in Japan (of which six are in Fukushima Prefecture), four in France, eight in Poland and two in Belarus cooperated in the measurement and comparison of individual external doses in 2014. In total 216 high-school students and teachers participated in the study. Each participant wore an electronic personal dosimeter 'D-shuttle' for two weeks, and kept a journal of his/her whereabouts and activities. The distributions of annual external doses estimated for each region overlap with each other, demonstrating that the personal external individual doses in locations where residence is currently allowed in Fukushima Prefecture and in Belarus are well within the range of estimated annual doses due to the terrestrial background radiation level of other regions/countries.

Proximal bowel necrosis after high ligation of the inferior mesenteric artery in colorectal surgery

BACKGROUND AND AIMS

High ligation of the inferior mesenteric artery may jeopardize blood supply to the proximal bowel. We undertook this study to review the clinical features and outcomes of patients who developed proximal bowel necrosis after high ligation of the inferior mesenteric artery, and to assess the incidence and the risk factors for this complication.

MATERIALS AND METHODS

A retrospective analysis of patients undergoing high or low ligation for sigmoid colon and rectal cancer with a primary anastomosis between April 2004 and March 2009 was performed. Patient and tumor characteristics and the incidence of bowel necrosis were reviewed.

RESULTS

Four hundred and nine patients were included to the analysis. Six out of 302 patients (2.0%) with high ligation developed proximal bowel necrosis, while the remaining 107 patients with low ligation did not suffer from this complication. All patients who developed proximal bowel necrosis underwent secondary surgery with resection of necrotic bowel. The pathological examination of the resected specimen revealed mucosal to transmural ischemic necrosis without the evidence of vascular thrombosis or embolic occlusion. Univariate analysis revealed that advanced age, cerebrovascular disease, and hypertension were significantly associated with proximal bowel necrosis. Multivariate analysis demonstrated that cerebrovascular disease was an independent predictor of this complication. Of these six patients, two died from associated complications.

CONCLUSIONS

Proximal bowel necrosis after high ligation is potentially fatal, and this report provides a warning in clinical settings where high ligation is indicated. Further studies are warranted to evaluate its distinct relationship with high ligation and to clarify whether low ligation would be a safeguard.

The Endoscopic Surgical Skill Qualification System for gastric surgery in Japan

INTRODUCTION

Laparoscopic surgery has been increasing in popularity in recent years. In 2004, the Japan Society for Endoscopic Surgery developed its Endoscopic Surgical Skill Qualification System (ESSQS) to assess surgeons.

METHODS

To earn the ESSQS accreditation, applicants must submit an unedited operative video in which they perform either a distal gastrectomy or pylorus-preserving gastrectomy with lymph node dissection for gastric cancer. The videos are assessed by two separate judges based on detailed criteria for common and procedure-specific technical-grade slips. Common criteria from all fields of gastrointestinal and general surgery are used to evaluate the basic laparoscopic surgical skills and autonomy of the operator. The target organ determines the procedure-specific criteria are set to assess whether or not adequate oncological clearance has been achieved.

RESULTS

Between 2004 and 2009, 154 (44.6%) out of 345 applicant surgeons assessed under the ESSQS for gastric surgery have been accredited. Interrater agreement was acceptable and ranged between 0.21 and 0.59.

CONCLUSION

The ESSQS system may facilitate improvement in surgical technique and the standardization of laparoscopic surgery in Japan.

Laparoscopic adrenalectomy by general surgeons familiar with laparoscopic surgical skills: experiences of a single center

INTRODUCTION

Laparoscopic adrenalectomy (LA) is still considered an advanced procedure requiring a high level of skills with potentially lethal pitfalls. We report our clinical outcomes of 50 cases of LA, and discuss whether a general surgeon is suitable to perform LA, and the effect of mentor-initiated training on improving outcomes.

METHODS

Patients' age and sex, size of tumor, preoperative diagnosis, procedure details, intra- and postoperative complications, operation time, final histological diagnosis, and length of stay of 50 consecutive cases of LA were collected through a review of hospital charts. These cases were divided into two equal consecutive groups. The first 25 cases were named Group A, and the latter 25 cases were named Group B, and two groups were compared.

RESULTS

Median operation time in Group B (110 min) was significantly shorter than that in Group A (125 min) (P=0.021). Mean postoperative hospital stay in Group B (7.0 ± 2.8 days) was significantly shorter than that in Group A (10.9 ± 8.8 days) (P=0.019). Only one case (Group B) of 50 LA (2%) required a conversion to open adrenalectomy because of failure to control bleeding during dissection.

CONCLUSION

Under mentor-initiated training, general surgeons with experience of more than 50 cases of laparoscopic cholecystectomies can attain favorable clinical outcomes in LA.

Distribution of the first metastatic lymph node in colon cancer and its clinical significance

INTRODUCTION

The pattern of distribution of lymph node metastasis in resected specimens of colon cancer has been rarely reported in the English literature. The aim of this study was to determine the location of the first metastatic lymph node, giving insight into the drainage pattern of colon cancer lymphatics.

METHOD

All lymph nodes in the mesentery of the resected specimen were carefully harvested and their precise locations documented. Patients with a single metastatic node in the resected specimen were included in the study.

RESULTS

Ninety-three patients with only one metastatic lymph node found on histology were studied. The mean number of lymph nodes per specimen was 22.3 (range: 8-72). The patients' first metastatic node was not directly below the tumour in 48% of cases. The first metastatic node was found in the region either along the feeding vessels (skipping the pericolic nodes) or in the pericolic area outside 5 cm on either side of the tumour edge in 18% of cases. No factors were found to be predictive for lymph node metastasis occurring elsewhere other than in the pericolic region just below the tumour.

CONCLUSION

Although there has been recent resurgence of interest in using sentinel node biopsy to limit surgical dissection to facilitate minimally access and natural orifice surgery, the present study is a warning that this may compromise oncological clearance. Radical surgery should remain standard practice for colorectal cancer.

Multimedia article. Transanal endoscopic resection of the rectum with high ligation on a swine model--a novel type of natural orifice endoscopic surgery

We present the video of a transanal radical resection of the rectum on a swine model (see Video, Supplemental Digital Content 1, http://links.lww.com/DCR/A4). The equipment used included simple instruments used in perianal surgery and a flexible endoscope with diathermy. The equipment and skill set required for this technique is easily accessible and reproduced. The potential exists to further develop this procedure with the ultimate aim of performing an incisionless and painless radical resection of the rectum in humans.

Promoter hypermethylation of tumor-related genes in sporadic colorectal cancer in young patients

Sporadic colorectal cancer (SCRC) occurring in young patients represent a subset with a higher proportion of advanced tumors and a poor prognosis, however, the genetic basis of SCRCs has not yet been sufficiently studied. We assigned 16 SCRC patients aged 40 years or less to group 1, and 30 SCRCs patients aged 65 years or more to group 2. The methylation status in the promoter of 7 tumor suppressor genes regarding these two groups was then examined. The average number of hypermethylated tumor-related genes per sample in group 1 was 1.50 +/- 0.07, which was significantly lower than that in group 2 of 2.73 +/- 1.24 (p = 0.0040). The frequencies of the promoter hypermethylation of hMLH1, p15INK4b, p16INK4a, and RASSF1A in group 1 were 12.5%, 12.5%, 12.5%, 6.3%, and 0.0%, which were substantially less frequent than those same rates observed in group 2. In contrast, the frequencies of the promoter hypermethylation of APC, MGMT, p14ARF, in group 1 were 43.8%, 37.5%, and 31.3%, which were as frequent as those seen in group 2. The promoter hypermethylation of APC, MGMT, and pl4ARF is therefore considered to be closely related to the development of SCRCs in young patients, regardless of aging.

Frequent reduced expression of alpha-1B-adrenergic receptor caused by aberrant promoter methylation in gastric cancers

Recent studies have suggested that epigenetic inactivation of tumour-related genes by promoter methylation participates in the development of gastric cancer. We newly identified the frequently aberrant promoter methylation of alpha-1B-adrenergic receptor (ADRA1B) in colorectal cancer by methylation-sensitive representational difference analysis (MS-RDA) and examined the methylation status of the ADRA1B promoter in 34 paired samples of colorectal cancer and surrounding epithelial tissue, and 34 paired samples of gastric cancer and surrounding epithelial tissue. In colorectal cancers, only four of 34 (11.8%) tumours showed ADRA1B promoter methylation. In contrast, ADRA1B promoter methylation was detected in 24 of 34 (70.6%) gastric cancers and in 14 of 34 (41.2%) surrounding epithelial tissues. The frequency of ADRA1B promoter methylation was higher in gastric epithelial tissues with intestinal metaplasia (41.6%) than in those without intestinal metaplasia (25.0%). Reverse transcription–PCR detected reduced ADRA1B expression in 12 of 18 (66.7%) gastric cancers, and its promoter methylation was detected in 11 of these 12 (91.7%) gastric cancers with reduced ADRA1B expression. Thus, ADRA1B promoter is frequently methylated in gastric cancer. Our results suggest that the ADRA1B gene is an important tumour-related gene frequently involved in the development and progression of gastric cancer.

A multicenter study on laparoscopic surgery for colorectal cancer in Japan

BACKGROUND

Laparoscopic colectomy for malignant disease technically is feasible but not widely accepted because there are no large-series studies or data on long-term outcomes. A retrospective, multicenter study investigating a large series of patients was conducted in Japan to evaluate preliminary long-term results of laparoscopic surgery for colorectal cancer.

METHODS

The study group comprised 2,036 patients who underwent laparoscopic colorectal resection April 1993 to August 2002 in 12 participating surgical units (Japanese Laparoscopic Surgery Study Group).

RESULTS

Of the 1,495 patients with colon cancer, 781 (59%) had International Union Against Cancer (UICC) stage I, 248 (19%) had stage II, and 284 (22%) had stage III disease. Cancer recurred for 61 (4.1%) of 1,367 curatively treated patients (median follow-up period, 32 months; range, 6-125 months). The 5-year survival rate was 96.7% for stage I, 94.8% for stage II, and 79.6% for stage III disease. Of the 541 patients with rectal cancer, 220 (56%) had stage I, 62 had (16%) stage II, and 108 (28%) had stage III disease. Cancer recurred for 30 (5.6%) of 476 curatively treated patients (median follow-up period, 25 months; range 6-102 months). The 5-year survival rate was 95.2% for stage I, 85.2% for stage II, and 80.8% for stage III disease.

CONCLUSIONS

The findings indicate that laparoscopic surgery for colorectal cancer yields an oncological outcome as good as that reported for conventional open surgery in the Japanese Registry for all disease stages.

Frequent involvement of ras-signalling pathways in both polypoid-type and flat-type early-stage colorectal cancers

The development of colorectal neoplasms proceeds mainly via the adenoma-carcinoma sequence. BRAF and RASSF1A are members of Ras-signaling pathways, but the roles of their aberrations in colorectal carcinogenesis remain unclear. The authors studied mutations of the BRAF and K-ras genes, RASSF1A promoter methylation, and p53 overexpression in 43 polypoid-type and 30 flat-type early-stage colorectal cancers. No tumor simultaneously showed any combination of K-ras mutations, BRAF mutations, and RASSF1A promoter methylation. Three of the 73 tumors (4.1%) had BRAF mutations. All BRAF mutation-positive tumors were flat-type cancers, not associated with coexisting adenoma or p53 overexpression. RASSF1A promoter methylation was detected in 12 out of 73 tumors (16.4%), and the proportion of positive cases was similar in polypoid-type and flat-type cancers. BRAF mutations, K-ras mutations, and RASSF1A promoter methylation independently participate in early-stage colorectal carcinogenesis. BRAF mutations are involved only in flat-type cancers, whereas RASSF1A promoter methylation is involved in both polypoid-type and flat-type cancers. Thus, BRAF mutations most likely participate in de novo colorectal carcinogenesis, K-ras mutations in the adenoma-carcinoma sequence of colorectal carcinogenesis, and RASSF1A promoter methylation in both cascades.

Natural history of a patient with malignant nonfunctioning islet cell tumor associated with unresectable multiple liver metastases

Islet cell tumors of the pancreas are uncommon. Approximately 15% of islet cell tumors are nonfunctioning and have a higher malignancy rate than their functioning counterparts. Though, because of the rarity of malignant nonfunctioning islet cell tumors, the natural history of a patient with this tumor has not been clearly defined. We describe a young patient with unresectable malignant nonfunctioning islet cell tumor associated with multiple liver metastases. He was treated with palliative therapies to improve his quality of life, but did not undergo surgical removal of tumors or systemic chemotherapy. He survived for 46 months since laparotomy for histological diagnosis. Our findings may represent the natural history of patients with unresectable malignant nonfunctioning islet cell tumor, and suggest that palliative therapy may contribute not only to the improvement of a patients' quality of life but also the prolongation of survival.

Runme Shaw Memorial Lecture 2002. Modern management of colorectal polyps: Are they all premalignant?

There are various types of polyps in the colon and rectum. Most colorectal polyps in the colon and rectum are either adenomas or hyperplastic polyps. In general, adenomas are considered to be premalignant. Adenoma-carcinoma sequence is an established theory of carcinogenesis in the large bowel in Western countries. However, small adenomas are ubiquitous phenomena, and it is questionable whether they are actually precancerous. Most small adenomas did not become larger in our colonoscopic follow-up study of small adenomas measuring 5 mm or less. It was considered safe to leave such small adenomas behind, particularly in a situation in which follow-up examination is periodically performed, such as in patients who have undergone colorectal cancer surgery before. In Japan, small flat carcinomas have been reported as an important precursor of advanced colorectal carcinoma. They are also found in Western population. The malignancy rate of small flat and depressed lesions was significantly higher than that of polypoid lesions. Although small flat carcinomas are less frequently seen than polypoid-type carcinomas in the early stages, they are considered to be an important precursor of advanced colorectal cancer.

Flat and depressed lesions of the colon and rectum: Pathogenesis and clinical management

INTRODUCTION

It is not clear whether flat lesions play a role in the pathogenesis of colorectal carcinoma. Flat lesions are being increasingly recognised with new colonoscopic techniques.

MATERIALS AND METHODS

A total of 10,939 consecutive colonoscopies were performed over a 9-year period. After bowel preparation with polyethylene glycol electrolyte lavage solution, high-resolution video colonoscopy and indigocarmine spraying were performed to detect flat lesions. All lesions suggesting neoplastic change were removed by polypectomy or surgery. Cancers invading beyond the submucosal layer were excluded from this analysis. The gross appearance of flat-type lesions was classified as flat elevated type or flat depressed type based on the presence or absence of central depression.

RESULTS

A total of 5408 neoplastic lesions were index lesions, including 5035 adenomas and 373 carcinomas (124 with submucosal invasion). The prevalence of flat depressed and flat elevated lesions were 2.8% and 18.1%, respectively. Submucosal invasion rates were 17.1% in the flat depressed, 0.8% in the flat elevated, 1.6% in the sessile, 4.0% in pedunculated lesions and 9.3% in creeping lesions. The submucosal invasion rate in the flat depressed lesions was significantly higher than in any others, except for creeping lesions (P = 0.06). The percentage of flat elevated and flat depressed carcinomas among all carcinomas invading the submucosa was 6.5% and 21.0%, respectively.

CONCLUSION

Flat lesions were common during routine colonoscopy. One-quarter of colorectal cancers may be derived from flat lesions. Training in dye spray technique may result in a higher detection rate of flat colonic lesions.

A small leiomyosarcoma of the pancreas treated by local excision

BACKGROUND

Leiomyosarcoma of the pancreas is a very rare tumour; only 33 cases have been reported in the English literature. Because these tumours tend to be large and locally advanced, extended resection such as pancreatoduodenectomy or distal pancreatectomy has been advocated.

CASE OUTLINE

A 25-year-old woman with left-sided back pain had a small low-density lesion (2 x 2 cm) in the pancreatic body on computed tomography (CT). The tumour was initially diagnosed as a pseudocyst and was managed conservatively. A repeat CT scan 10 months later showed an increase in the size of the lesion (3.5 x 3.5 cm) with contrast enhancement of a high-density area. The diagnosis was therefore changed to papillary-cystic neoplasm. At laparotomy, the tumour seemed to be arising from the mid-body of the pancreas with no invasion into surrounding organs. Local excision of the tumour was performed. Pathological examination revealed a leiomyosarcoma of the pancreas.

DISCUSSION

Complete surgical resection offers the only potential chance of cure for patients with leiomyosarcoma of the pancreas.The lack of evidence of recurrence at three-and-a-half years suggests that the less invasive surgical procedure in the present case has been curative. Careful and intraoperative exploration was important to determine the best surgical procedure.

Extensive methylation of hMLH1 promoter region predominates in proximal colon cancer with microsatellite instability

BACKGROUND & AIMS

Methylation of the hMLH1 promoter region has been suggested to cause microsatellite instability (MSI) in sporadic colorectal carcinoma (CRC). We studied the methylation profile in a wide region of the hMLH1 promoter and compared with the hMLH1 protein expression and MSI status in 88 cases of sporadic CRC.

METHODS

Na-bisulfite treatment and polymerase chain reaction single-strand conformation polymorphism analysis was performed using 5 sets of polymerase chain reaction primers spanning the promoter region of the hMLH1 to examine methylation status. Results were compared with immunostaining using anti-hMLH1 monoclonal antibody and MSI status of the tumor samples.

RESULTS

Methylation status was classified as full or partial methylation. Full methylation indicates the methylation of all CpG sites in the examined regions. Methylation of the hMLH1 promoter was observed in 88.9% (16 of 18) of CRCs showing high frequency MSI (MSI-H), among which 89% (14 of 16) had full methylation with reduced hMLH1 protein expression. All cases showing full methylation were proximal colon tumors with MSI-H. In cases with partial methylation, only the upstream region of the hMLH1 promoter was methylated. Partial methylation was also shown in 33.3% (6 of 18) of the normal mucosa of MSI-H cases. Frequencies of methylation were significantly correlated with female gender (P = 0.0009) and aging (P = 0.007).

CONCLUSIONS

Full methylation of the hMLH1 promoter region and subsequent gene inactivation may play a crucial role in the carcinogenesis of MSI-H CRCs in the proximal colon. Methylation upstream of the hMLH1 promoter appears to be an early event in the carcinogenesis of MSI-H tumors.

Cross-reactive mechanism for the false elevation of free triiodothyronine in the patients treated with diclofenac

We report three cases of patients exhibiting a false elevation of serum free triiodothyronine (FT3) as a result of a cross-reaction with diclofenac. The first case is a 66-yr-old woman with a long history of rheumatoid arthritis (RA). The patient was receiving diclofenac for the treatment of her RA. The patient was subsequently diagnosed as having thyroid papillary adenocarcinoma and received a subtotal thyroidectomy. After the operation, the patient exhibited postoperative hypothyroidism except for a gradual elevation of FT3. The other two patients also exhibited an elevated serum FT3 level after the administration of diclofenac. Serum FT3 levels in these patients decreased to normal or below normal after diclofenac administration was discontinued. In the first case, the elimination of immunoglobulin from the sera using polyethylene glycol precipitation did not reduce the FT3 level. In our hospital, Vitros ECi (enhanced chemiluminescence enzyme immunoassay) system and Vitros FT3 kit were used for FT3 assay. The patient's FT3 levels were normal or below normal when they were measured using other FT3 kits. FT3 was also detected when diclofenac was dissolved in a phosphate buffered saline. Therefore, we concluded that a cross-reaction between FT3 and diclofenac was the mechanism causing the false elevation of FT3 in these patients.

Detection of pinpoint tenderness on the appendix under ultrasonography is useful to confirm acute appendicitis

HYPOTHESIS

Ultrasonography can be efficiently performed using new criteria for the diagnosis of acute appendicitis.

DESIGN

Prospective trial.

PATIENTS

Eighty-nine patients admitted to the hospital with suspected appendicitis between March 1998 and November 2000.

INTERVENTION

At hospital admission, a staff surgeon evaluated each patient and determined whether the patient had appendicitis requiring immediate surgery or another disease. Patients then underwent ultrasonography. A sonographic transducer was placed on the area of maximal tenderness. When the pathological manifestation was depicted, the examiner slipped a fingertip between the transducer and the patient's skin and then pressed the area of depicted pathological manifestation to find pinpoint tenderness. When maximal pinpoint tenderness was noted on the appendix or on pathological manifestations contiguous to the appendix, we diagnosed the condition as appendicitis.

MAIN OUTCOME MEASURES

Sensitivity, specificity, positive and negative predictive values, and overall accuracy.

RESULTS

The diagnosis of appendicitis by this criteria had a sensitivity of 86.7%, a specificity of 89.7%, a positive predictive value of 94.5%, a negative predictive value of 76.5%, and overall accuracy of 87.6%. All 50 patients with pinpoint tenderness noted on the appendix had appendicitis. The surgeon's initial clinical impression had a sensitivity of 83.3%, a specificity of 44.8%, a positive predictive value of 75.8%, a negative predictive value of 56.5%, and overall accuracy of 70.8%.

CONCLUSIONS

The efficacy of ultrasonography using the simple criteria was superior to that of the surgeon's initial clinical impression (P<.001). Our ultrasonographic criteria for the diagnosis of appendicitis are simple to use and efficient.

Pelvic floor disturbance after childbirth: vaginal delivery damages the upper levels of sphincter innervation

PURPOSE

Vaginal delivery disturbs pelvic floor innervation, which has previously been studied as a single mechanism. The effects of childbirth on innervation at different levels of the anal sphincter system were studied after childbirth.

METHODS

Both anal manometry and motor latencies were measured in 67 females. Twenty-nine females (30.8 +/- 4.4 years) were examined four days after vaginal delivery. Eleven of these 29 females were re-examined five months after vaginal delivery. Nineteen females (33.6 +/- 4.6 years) who were examined five to nine days after undergoing an elective cesarean section and 19 asymptomatic, nonpregnant females (26.8 +/- 6.9 years) served as controls. Motor latencies were bilaterally measured within the anal sphincter system at 5, 3.8, 2.6, and 1.5 cm from the perineal skin by using a concentric needle electrode after sacral magnetic stimulation. Means of the bilateral latencies were analyzed.

RESULTS

In postpartum females who gave birth vaginally, motor latencies at 5 and 3.8 cm, although not those at 2.6 and 1.5 cm, from the perineal skin were significantly prolonged, and anal pressure monitored by maximum resting and squeeze pressures was significantly decreased compared with that in control females. The decreased anal pressure normalized spontaneously. The prolonged motor latencies at the upper two levels of the anal sphincter system persisted in these females for five months after vaginal delivery.

CONCLUSIONS

The disturbance of innervation of the upper anal sphincter system after vaginal delivery may last for a long time, whereas the decreased anal pressure normalizes in a short time. The protracted disturbance of innervation of the upper anal sphincter system may be associated with later development of fecal incontinence.

Microsatellite instability in inflamed and neoplastic epithelium in ulcerative colitis

BACKGROUND

Several genetic alterations have been documented in dysplasia and cancer developing in ulcerative colitis (UC). However, the microsatellite instability (MSI) status has rarely been described, especially in the inflamed epithelium of UC.

AIMS

To study MSI status during neoplastic and inflammatory changes in UC.

METHODS

Seventy five surgically resected samples of colorectal mucosa, taken from 16 colectomy specimens of patients with UC were examined: five patients had a long duration with dysplasia or cancer (UC-LD with neoplasm), seven patients had a long duration without neoplastic changes (UC-LD without neoplasm), and four patients had a short duration without neoplastic changes (UC-SD). In addition to MSI status examined by six microsatellite markers, p53 expression was compared among the three groups.

RESULTS

With regard to non-neoplastic inflamed epithelium, MSI in two or more loci (MSI> or =2) was seen more frequently in the UC-LD without neoplasm group than in the UC-SD group (six of 14 v one of 12; p = 0.060), and significantly more often than in the UC-LD with neoplasm group (six of 14 v two of 23; p = 0.016). In the UC-LD without neoplasm group, MSI> or =2 was detected significantly more frequently in patients with severe inflammation than in those with mild inflammation (six of nine v none of five; p = 0.028). With regard to neoplastic epithelium in the UC-LD with neoplasm group, MSI in two or more loci was found in three of 17, and p53 overexpression was seen in 11 of 17 of the neoplastic lesions.

CONCLUSIONS

A high incidence of MSI in long standing UC with severe inflammation probably reflects genomic instability caused by repeated inflammatory stress. Thus, the influence of inflammation should be considered when estimating MSI in UC. It is possible that changes in p53 expression are important in the development of cancer in UC.

Allelotype frequency of the thiopurine methyltransferase (TPMT) gene in Japanese

Polymorphisms at three loci in the thiopurine methyltransferase (TPMT) gene are known to be responsible for azathioprine and 6-mercaptopurine (6MP) toxicity. Among them, only TPMT*3C variant allele with A719G mutation was found in 15/522 (2.9%; 17/1044 alleles; 1.6%) Japanese individuals including two homozygotes. The allele frequency was different from that in Caucasians, and investigation of TPMT polymorphisms with consideration of ethnic differences before administration of azathioprine or 6MP may provide clinically useful information.

Absence of endothelial cells, central necrosis, and fibrosis are associated with aggressive inflammatory breast cancer

We recently established a new human inflammatory breast cancer (IBC) xenograft (WIBC-9) originating from a patient with IBC. The graft was transplantable in BALB/c nude and severe combined immunodeficient (SCID) mice. WIBC-9 was frequently accompanied by lung metastasis and exhibited erythema of the overlying skin, reflecting its human counterpart. Histological study of the original tumor and WIBC-9 revealed invasive ductal carcinoma with a hypervascular structure of solid nests and marked lymphatic permeation in the overlying dermis. In the central part of the solid nests, absence of endothelial cells, central necrosis, and fibrosis were observed. In vitro, WIBC-9 formed tube-like structures and loops, reflecting its in vivo feature and its human counterpart. WIBC-9 exhibited aneuploidy, ErbB-2 gene amplification, and an absence of estrogen receptor and progesterone receptor, which is consistent with IBC. Comparative studies of WIBC-9, three established non-IBC xenografts, and a human breast cancer cell line (SK-BR3) by reverse transcription-PCR, ELISA, and immunohistochemistry indicated that certain human genes (interleukin 8, vascular epidermal growth factor, basic fibroblast growth factor, angiopoietin 13, Flt-1, Tie-2, and Tie-1) and certain murine genes (integrin alpha(v)beta3, flt-1, tie-2, vascular epidermal growth factor, and CD31) were overexpressed in exposure to tumor cells. The molecular basis and these unique histological features may be associated with aggressive IBC on angiogenic and nonangiogenic pathways.

Frequent activation of the beta-catenin-Tcf signaling pathway in nonfamilial colorectal carcinomas with microsatellite instability

It has been reported that wild-type APC protein forms a complex with beta-Catenin and GSK3beta, inducing degradation of beta-Catenin in normal cells. Both beta-Catenin and APC gene mutations have recently been shown to activate the same signaling pathway. Frequent mutations of beta-Catenin in hereditary nonpolyposis colorectal carcinomas have also been reported. It was, however, controversial whether the mutation of the beta-Catenin gene was frequent in nonfamilial colorectal carcinomas with high-frequency microsatellite instability (MSI-H). We analyzed the mutations of the APC and beta-Catenin genes in 56 nonfamilial colorectal carcinomas stratified according to the presence or absence of microsatellite instability (MSI). APC mutations were identified in 11 of 22 (50%) cases of MSI-H and 14 of 34 (41%) cases of microsatellite-stable (MSS)/low-frequency microsatellite instability (MSI-L). In contrast, the frequency of beta-Catenin mutations was significantly higher in MSI-H (6/22; 27%) than in MSS/MSI-L (1/34; 3%) (P = 0.01). beta-Catenin mutations were not detected in carcinomas with APC mutation. APC mutation occurred irrespective of MSI status. beta-Catenin mutation, however, occurred frequently in MSI-H carcinomas. Our data suggest that activation of the beta-Catenin-Tcf signaling pathway, through either beta-Catenin or APC mutation, frequently contributes to MSI-H nonfamilial colorectal carcinomas (17/22; 77%).

Exaggerated vascular and renal pathology in endothelin-B receptor-deficient rats with deoxycorticosterone acetate-salt hypertension

BACKGROUND

Endothelin (ET)-1 plays an important role in the pathogenesis of deoxycorticosterone acetate (DOCA)-salt-induced hypertension. We evaluated the pathological role of ET(B) receptors in DOCA-salt-induced hypertension, cardiovascular hypertrophy, and renal damage by using the spotting-lethal (sl) rat, which carries a naturally occurring deletion in the ET(B) receptor gene.

METHODS AND RESULTS

Homozygous (sl/sl) rats exhibit abnormal development of neural crest-derived epidermal melanocytes and the enteric nervous system, and they do not live beyond 1 month because of intestinal aganglionosis and intestinal obstruction. The dopamine ss-hydroxylase (DssH) promoter was used to direct ET(B) transgene expression in sl/sl rats to support normal enteric nervous system development. DssH-ET(B) sl/sl rats live into adulthood and are healthy, expressing ET(B) receptors in adrenal glands and other adrenergic neurons. When homozygous (sl/sl) and wild-type (+/+) rats, all of which were transgenic, were treated with DOCA-salt, homozygous rats exhibited earlier and higher increases in systolic blood pressure than did wild-type rats. Chronic treatment with ABT-627, an ET(A) receptor antagonist, completely suppressed DOCA-salt-induced hypertension in both groups. Renal dysfunction and histological damage were more severe in homozygous than in wild-type rats. Marked vascular hypertrophy was observed in homozygous rats than in wild-type rats. Renal and vascular injuries were significantly improved by ABT-627. In DOCA-salt-treated homozygous rats, there were notable increases in renal, urinary, and aortic ET-1, all of which were normalized by ABT-627.

CONCLUSIONS

ET(B)-mediated actions are protective in the pathogenesis of DOCA-salt-induced hypertension. Enhanced ET-1 production and ET(A)-mediated actions are responsible for the increased susceptibility to DOCA-salt hypertension and tissue injuries in ET(B) receptor-deficient rats.

Analyses of segmental lymph node metastases and intrapulmonary metastases of small lung cancer

BACKGROUND

Curativity and indications for limited resection of small peripheral lung cancer remain controversial.

METHODS

Pathologic investigations of segmental lymph node metastases and intrapulmonary metastases in the resected lobe were performed for 94 small peripheral lung cancers (3.0 cm or less in diameter).

RESULTS

Nine patients had segmental lymph node metastases, 1 had intrapulmonary metastases, and 1 had both. Of these 11 patients, 5 had metastases limited to the primary tumor-bearing segments, 2 had metastases in nonprimary tumor-bearing segments, and 4 had metastases in both. Of the 10 patients with segmental lymph node metastases, 7 had metastases in both lobar-hilar and mediastinal lymph nodes, and 3 of 8 with adenocarcinoma had a tumor 2.0 cm or less.

CONCLUSIONS

Segmentectomy seems more favorable than wedge resection, but the risk of remnant tumor remains as compared with lobectomy. Evaluation of lobar-hilar or mediastinal lymph nodes is helpful to determine the presence or absence of segmental lymph node metastases. Limited resection can be undertaken with smaller tumors to allow preservation of more lung function while accepting a somewhat enhanced risk of recurrence.

Pathogenesis of non-familial colorectal carcinomas with high microsatellite instability

AIMS

Microsatellite instability (MSI) was first observed in hereditary non-polyposis colorectal carcinoma (HNPCC) and was subsequently seen in non-familial colorectal carcinoma. The relation between MSI and cancer associated genes in non-familial colorectal carcinomas has yet to be evaluated. To clarify this matter, changes in cancer associated genes were examined in non-familial colorectal carcinomas.

METHODS

Alterations in the adenomatous polyposis coli (APC), p53, and Ki-ras genes were analysed in 24 MSI high (alterations in four to seven of seven loci), nine MSI low (alterations in one to three of seven loci), and 31 MSI negative non-familial carcinomas. The hMSH2 and hMLH1 genes were also analysed in 24 MSI high carcinomas.

RESULTS

Both the frequencies and types of alterations in the APC and p53 genes in MSI high carcinomas were the same as those in MSI low and MSI negative carcinomas; however, they were different from those seen in HNPCC. The frequency of Ki-ras mutation was significantly lower in the MSI high cases (two of 24; 8%) than in the others (15 of 38; 39%). Somatic mutation of hMSH2 or hMLH1 was detected in six of 24 (25%) of the MSI high cases.

CONCLUSIONS

These results suggest that APC and p53 alterations occur irrespective of microsatellite instability status in non-familial colorectal carcinomas, and that Ki-ras mutation is not involved in MSI high non-familial colorectal carcinoma. The pathogenesis of these carcinomas may differ from both the usual adenoma-carcinoma sequence and HNPCC carcinogenesis.

Increased susceptibility to deoxycorticosterone acetate-salt-induced hypertension in endothelin-B-receptor-deficient rats

We evaluated the role of endothelin-B- (ET(B)) receptor-mediated action in the development and maintenance of deoxycorticosterone acetate (DOCA)-salt-induced hypertension, cardiovascular hypertrophy and renal damage, using the spotting lethal (sl) rat which carries a naturally occurring deletion in the ET(B)-receptor gene. Homozygous (sl/sl) rats exhibit abnormal development of the neural crest-derived epidermal melanocytes and the enteric nervous system (ENS), and do not live beyond 1 month because of intestinal aganglionosis and resulting intestinal obstruction. Therefore, the dopamine-beta-hydroxylase (D betaH) promoter was used to direct ET(B) transgene expression in sl/sl rats to support normal ENS development. D betaH-ET(B) sl/sl rats live into adulthood and are healthy, expressing ET(B)-receptor in adrenals and other adrenergic neurons. When homozygous (sl/sl) and wild-type (WT) (+/+) rats, all of which were transgenic, were treated with DOCA and salt for 4 weeks, the homozygous rats exhibited significantly earlier and higher increases in systolic blood pressure than WT rats. The daily oral administration of ABT-627, a selective ET(A)-receptor antagonist, almost completely suppressed the DOCA-salt-induced hypertension in both groups. Renal dysfunction and histological damage induced by DOCA-salt treatment were more severe in homozygous than in WT rats. Increased and marked vascular hypertrophy of the aorta was also observed in homozygous rats, compared with WT rats. Renal and vascular injuries induced by DOCA and salt were significantly improved by ABT-627 administration. We propose that ET(B)-receptor-mediated actions are protective factors in the pathogenesis of DOCA-salt-induced hypertension. ET(A)-mediated actions are at least partly responsible for the increased susceptibility to DOCA-salt-induced hypertension and related tissue injuries in ET(B)-receptor-deficient rats.

Predictive factors for detecting colorectal carcinomas in surveillance colonoscopy after colorectal cancer surgery

PURPOSE

The aim of this study was to identify the high-risk groups for metachronous colorectal carcinoma among patients who undergo colorectal cancer surgery.

METHODS

Three hundred forty-one patients undergoing colorectal cancer surgery who had undergone surveillance colonoscopy at least twice during a period of more than three years were analyzed. A metachronous colorectal carcinoma was defined as a new colorectal carcinoma detected by surveillance colonoscopy after surgery.

RESULTS

Surveillance colonoscopy was performed 4.6 times per patient during an average of 6.2 years. Twenty-two metachronous colorectal carcinomas in 19 patients were detected, and 14 (64 percent) of 22 were detected within five years of surgery. The cumulative incidence of developing colorectal carcinomas during a five-year period was 5.3 percent. Seventeen (77 percent) of 22 carcinomas were 10 mm or less in size. Ten (71 percent) of the 14 carcinomas in early stages showed a flat appearance. Univariate analysis showed that extracolonic malignancy, coexistence of adenoma, and synchronous multiple colorectal carcinoma were significant predictive factors for detecting colorectal carcinomas in surveillance colonoscopy and that family history of colorectal carcinoma was a possible predictive factor. Multivariate analysis performed with Cox proportional hazards regression model showed that extracolonic malignancy and the coexistence of adenoma were significant predictive factors.

CONCLUSION

We recommend that patients with the above predictive factors receive surveillance colonoscopy meticulously and regularly.

Apoptosis and its regulation in flat-type early colorectal carcinoma: comparison with that in polypoid-type early colorectal carcinoma

PURPOSE

The aim of this study was to investigate the relationship among apoptotic cell death, proliferative activity, and the expression of apoptosis-regulating proteins (p53, p21 (WAF1/CIP1), and bax) in flat-type early colorectal carcinoma and to compare these factors with those in polypoid-type early colorectal carcinoma.

METHODS

Formalin-fixed, paraffin-embedded tissues of 11 flat-type early colorectal carcinomas and 17 polypoid-type early carcinomas were studied. The histologic diagnosis was either well-differentiated adenocarcinoma or carcinoma in adenoma, and the depth of invasion was limited to mucosa or submucosa. Apoptotic cells were detected by terminal deoxynucleotide transferase-mediated deoxyuridine triphosphate-biotin nick end-labeling method, and proliferative activity was determined by Ki-67 immunohistochemistry using monoclonal antibody MIB-1. Apoptosis-regulating proteins were determined by immunohistochemistry using antibody DO-7 (p53), Cip1 (p21 (WAF1/CIP1)), and Bax (bax).

RESULTS

There was no significant difference in terminal deoxynucleotide transferase-mediated deoxy-uridine triphosphate-biotin nick end-labeling index between flat-type early colorectal carcinoma and polypoid-type early carcinoma, at 1.9 vs. 1.1, respectively. In flat-type carcinoma terminal deoxynucleotide transferase-mediated deoxyuridine triphosphate-biotin nick end-labeling index in the p53 protein overexpression group was significantly smaller than that in the p53 protein-negative group (P < 0.05). The Ki-67 labeling index/terminal deoxynucleotide transferase-mediated deoxyuridine triphosphate-biotin nick end-labeling index ratio in the p53 protein overexpression group was significantly higher than that in the p53 protein-negative group (P < 0.05). In polypoid-type carcinoma, the terminal deoxynucleotide transferase-mediated deoxyuridine triphosphate-biotin nick end-labeling index and Ki67/terminal deoxynucleotide transferase-mediated deoxyuridine triphosphate-biotin nick end-labeling index ratio showed no significant difference between the p53 protein overexpression group and p53 protein-negative group.

CONCLUSION

p53-dependent apoptosis may contribute to the development of flat-type early colorectal carcinoma. Apoptosis and its regulation in flat-type early colorectal carcinoma may differ from those in polypoid-type carcinoma.

[Laparoscopic colectomy for colorectal carcinoma]

Laparoscopic-assisted colectomy is considered to be a less invasive technique, and patients experience less pain and more rapid postoperative recovery. This operation has been indicated for large sessile adenomas or for early invasive carcinomas in Japan. The indications for this procedure in more advanced colorectal carcinomas is controversial. However, based on our experience with 130 cases, laparoscopic-assisted colectomy can be as curative as open colectomy provided that the patients are properly selected. In this review, the technical difficulties of this procedure are also discussed.

Variations in motor evoked potential latencies in the anal sphincter system with sacral magnetic stimulation

PURPOSE

The anal sphincter system of the skeletal musculature consists of various parts but functions as a single unit. The motor latencies measured at the puborectalis, deep external anal sphincter, superficial external anal sphincter, and subcutaneous external anal sphincter have yet to be clearly elucidated. This study was designed to measure the motor latencies of these sphincters separately and to investigate the electrophysiologic heterogeneity of the anal sphincter system.

METHODS

In 20 preoperative patients with colon cancer without either neurologic or anorectal diseases, motor evoked potentials were taken separately bilaterally at levels measuring approximately 5, 3.8, 2.6, and 1.5 cm from the perineal skin using a concentric needle electrode after magnetic stimulation on the sacral region. These latencies were considered to be separately measured at the puborectalis, deep, superficial, and subcutaneous external anal sphincter.

RESULTS

The motor latencies (median (95 percent confidence interval)) were 4.33 (4.1-4.93; right) and 4.24 (3.97-5.22; left) ms at the 5 cm level; 5.96 (5.45-7.32; right) and 6.44 (5.49-8.20; left) ms at the 3.8 cm level; 9.28 (7.99-11.21; right) and 8.88 (7.68-10.93; left) ms at the 2.6 cm level; and 11.06 (9.69-14.13; right) and 9.18 (8.09-10.31; left) ms at the 1.5 cm level. Significant differences were seen in the latencies between the 5 cm level and the other levels and between the 3.8 cm level and the other levels.

CONCLUSIONS

The motor latencies in the anal sphincter system significantly varied depending on the distance from the skin. The latency may be shortest in the puborectalis and increasingly longer in the deep, superficial, and subcutaneous EAS, in that order.

[Recent advances in colorectal cancer surgery]

Recent advances in colorectal cancer surgery have been made in improving the cure rate after surgery, the preservation of postoperative function, and the development of minimally invasive procedures. Indication for wide lymph node dissection in rectal cancer surgery is now limited to a smaller number of cases. Functional outcome is being improved thanks to the introduction of autonomic nerve preserving operations as well as the increasing number of sphincter preserving operations. Laparoscopic colectomy for cancer has been practiced for 7-8 years, and the advantages and disadvantages of this procedure are being clarified. Transanal endoscopic microsurgery (TEM) is a minimally invasive surgery for rectal tumors in early stages. The procedure is now overtaking the posterior surgical approach, which is used less and less in recent years. Future goals in colorectal cancer surgery are further improvements in the cure rate and the functional results. Minimally invasive surgery may become the established procedure after a careful assessment of its cure rate compared to the open surgical procedure.

Cytokine and hormonal responses in laparoscopic-assisted colectomy and conventional open colectomy

Interleukin-6 (IL-6) is an important mediator of the acute phase response and a sensitive marker of tissue damage. This study was conducted to investigate the fluctuation of serum cytokine and hormonal levels during the perioperative period after laparoscopic-assisted colectomy (LAC), and the data were compared with those after conventional open colectomy (OPEN). The subjects comprised eight patients who underwent OPEN and eight who underwent LAC. Blood samples were obtained by peripheral vein puncture before the induction of anesthesia, then 2, 4, 6, 8, 24, 48, and 72 h after skin incision to measure the levels of serum IL-6, adrenocorticotropic hormone (ACTH), cortisol, and antidiuretic hormone (ADH). The level of serum IL-6 increased significantly during the perioperative course in both groups; however, the level 4 h after the commencement of surgery and the peak level were significantly lower in the LAC group than in the OPEN group (P < 0.05). Plasma ACTH, cortisol, and ADH rapidly increased in both groups, but there was no significant difference between them. The IL-6 levels in collected ascites samples were not significantly different between the two groups. The changes in serum IL-6 levels indicate that LAC is less invasive than conventional open colectomy. These findings corresponded well with the clinical courses of the patients who underwent the two types of operations.