Preoperative sequential short-course radiation therapy and FOLFOX chemotherapy versus long-course chemoradiotherapy for locally advanced rectal cancer: a multicenter, randomized controlled trial (SOLAR trial)

BACKGROUND

Preoperative (chemo)radiotherapy has been widely used as an effective treatment for locally advanced rectal cancer (LARC), leading to a significant reduction in pelvic recurrence rates. Because early administration of intensive chemotherapy for LARC has more advantages than adjuvant chemotherapy, total neoadjuvant therapy (TNT) has been introduced and evaluated to determine whether it can improve tumor response or treatment outcomes. This study aims to investigate whether short-course radiotherapy (SCRT) followed by intensive chemotherapy improves oncologic outcomes compared with traditional preoperative long-course chemoradiotherapy (CRT).

METHODS

A multicenter randomized phase II trial involving 364 patients with LARC (cT3-4, cN+, or presence of extramural vascular invasion) will be conducted. Patients will be randomly assigned to the experimental or control arm at a ratio of 1:1. Participants in the experimental arm will receive SCRT (25 Gy in 5 fractions, daily) followed by four cycles of FOLFOX (oxaliplatin, 5-fluorouracil, and folinic acid) as a neoadjuvant treatment, and those in the control arm will receive conventional radiotherapy (45-50.4 Gy in 25-28 fractions, 5 times a week) concurrently with capecitabine or 5-fluorouracil. As a mandatory surgical procedure, total mesorectal excision will be performed 2-5 weeks from the last cycle of chemotherapy in the experimental arm and 6-8 weeks after the last day of radiotherapy in the control arm. The primary endpoint is 3-year disease-free survival, and the secondary endpoints are tumor response, overall survival, toxicities, quality of life, and cost-effectiveness.

DISCUSSION

This is the first Korean randomized controlled study comparing SCRT-based TNT with traditional preoperative LC-CRT for LARC. The involvement of experienced colorectal surgeons ensures high-quality surgical resection. SCRT followed by FOLFOX chemotherapy is expected to improve disease-free survival compared with CRT, with potential advantages in tumor response, quality of life, and cost-effectiveness.

TRIAL REGISTRATION

This trial is registered at Clinical Research Information under the identifier Service KCT0004874 on April 02, 2020, and at Clinicaltrial.gov under the identifier NCT05673772 on January 06, 2023.

Laparoscopic D3 oncological resection in splenic flexure cancer: Technical details and its impact on long-term survival

AIM

The applicability of laparoscopic D3 oncological resection for splenic flexure cancer (SFC) surgery has not been fully explored due to technical difficulties and variations in surgical procedure. The aim of this work is to describe the feasibility of performing laparoscopic D3 resection in SFC and its impact on long-term survival.

METHOD

A retrospective study on 47 out of 52 consecutive patients who underwent elective laparoscopic colectomy for SFC from December 2006 until December 2019 at Korea University Anam Hospital was performed. Data on patients' demographic and clinical features, surgical procedures, intraoperative and postoperative complications, pathological features and follow-up were collected. Categorical data are expressed as frequencies (n) and percentages (%). Continuous data are expressed as mean ± standard deviation and median (range). The Kaplan-Meier test was used to determine the overall survival (OS), progression-free survival (PFS) and disease-free survival (DFS).

RESULTS

The median age of patients was 67.0 years (range 27-87 years) and 72.3% were men. Ten (21.3%) patients presented with an obstructing tumour and underwent an elective laparoscopic colectomy, while 68.1% of patients presented with Stage II and III disease. The conversion rate was 4.3% and the morbidity rate was 31.9%. There was one postoperative death secondary to splenic infarction and anastomotic leak leading to multi-organ failure. Four deaths occurred due to disease progression during a median follow-up of 63.8 months. The rate of recurrence was 20%, the 5-year OS was 89.6% and the 5-year PFS was 72.9%. After R0 resection, the 5-year OS was 91.5% and the 5-year DFS was 74.5%.

CONCLUSION

Laparoscopic D3 colectomy for SFC is feasible, with an acceptable morbidity and long-term oncological outcome when performed by highly skilled laparoscopic colorectal surgeons with knowledge of the complex anatomy around the splenic flexure. Further randomized trials should be performed to determine the advantage of laparoscopic D3 colectomy over conventional colectomy for SFC.

Lower Incidence of Postoperative Urinary Retention in Robotic Total Mesorectal Excision for Low Rectal Cancer Compared with Laparoscopic Surgery

INTRODUCTION

The incidence and clinical significance of postoperative urinary retention (POUR) remain high. This study aimed to evaluate the incidence of POUR and related risk factors in patients who underwent total mesorectal excision (TMR) for low rectal cancer.

METHODS

This study is a retrospective review of a prospectively collected colorectal database from a single center. Data from patients who underwent surgery for low rectal cancer between September 2006 and May 2017 were analyzed to assess the risk factors of POUR. POUR was considered inability to void after urinary catheter removal requiring catheter reinsertion and difficulty in bladder emptying requiring intermittent catheterization.

RESULTS

Of 555 patients with low rectal cancer, 78 (14.1%) developed POUR. Based on multivariate logistic regression analysis, laparoscopic TMR (odds ratio [OR]; 2.114, 95% confidence interval [CI]; 1.212-3.689, p = 0.008) and postoperative ileus (OR; 2.389, 95% CI; 1.282-4.450, p = 0.006) were independent risk factors of POUR. Male gender, advanced age, neoadjuvant chemoradiation, longer operative time, abdominoperineal resection, and lateral pelvic lymph node dissection were not associated with POUR. Advanced age over 65 years also failed to show statistical significance (OR; 1.604, 95% CI; 0.965-2.668, p = 0.068).

CONCLUSION

Laparoscopic approach and postoperative ileus are risk factors for POUR after low rectal cancer surgery. We postulate that the benefits of robotic surgical systems compared to a laparoscopic approach may reduce the incidence of POUR.

Risk factors for local recurrence and long term survival after minimally invasive intersphincteric resection for very low rectal cancer: Multivariate analysis in 161 patients

INTRODUCTION

Intersphincteric resection (ISR) is the ultimate anal-sparing technique as an alternative to abdominoperineal resection in selected patients. Oncological safety is still debated. This study analyses long-term oncological results and evaluates risk factors for local recurrence (LR) and overall survival (OS) after minimally-invasive ISR.

MATERIALS AND METHODS

Retrospective single-center data were collected from a prospectively maintained colorectal database. A total of 161 patients underwent ISR between 2008 and 2018. OS and local recurrence-free survival (LRFS) were assessed using Kaplan-Meier analysis (log-rank test). Risk factors for OS and LRFS were assessed with Cox-regression analysis.

RESULTS

Median follow-up was 55 months. LR occurred in 18 patients. OS and LRFS rates at 1, 3, and 5 years were 96%, 91%, and 80% and 96%, 89%, and 87%, respectively. Tumor size (p = 0.035) and clinical T-stage (p = 0.029) were risk factors for LRFS on univariate analysis. On multivariate analysis, tumor size (HR 2.546 (95% CI: 0.976-6.637); p = 0.056) and clinical T-stage (HR 3.296 (95% CI: 0.941-11.549); p = 0.062) were not significant. Preoperative CEA (p < 0.001), pathological T-stage (p = 0.033), pathological N-stage (p = 0.016) and adjuvant treatment (p = 0.008) were prognostic factors for OS on univariate analysis. Preoperative CEA (HR 4.453 (95% CI: 2.015-9.838); p < 0.001) was a prognostic factor on multivariate analysis.

CONCLUSIONS

This study confirms the oncological safety of minimally-invasive ISR for locally advanced low-lying rectal tumors when performed in experienced centers. Despite not a risk factor for LR, tumor size and, locally advanced T-stage with anterior involvement should be carefully evaluated for optimal surgical strategy. Preoperative CEA is a prognostic factor for OS.

Clinical Outcomes of Ileostomy Closure According to Timing During Adjuvant Chemotherapy After Rectal Cancer Surgery

PURPOSE

No guidelines exist detailing when to implement a temporary ileostomy closure in the setting of adjuvant chemotherapy following sphincter-saving surgery for rectal cancer. The aim of this study was to evaluate the clinical and oncological outcomes of ileostomy closure during adjuvant chemotherapy in patients with curative resection of rectal cancer.

METHODS

This retrospective study investigated 220 patients with rectal cancer undergoing sphincter-saving surgery with protective loop ileostomy from January 2007 to August 2016. Patients were divided into 2 groups: group 1 (n = 161) who underwent stoma closure during adjuvant chemotherapy and group 2 (n = 59) who underwent stoma closure after adjuvant chemotherapy.

RESULTS

No significant differences were observed in operative time, blood loss, postoperative hospital stay, or postoperative complications in ileostomy closure between the 2 groups. No difference in overall survival (P = 0.959) or disease-free survival (P = 0.114) was observed between the 2 groups.

CONCLUSION

Ileostomy closure during adjuvant chemotherapy was clinically safe, and interruption of chemotherapy due to ileostomy closure did not change oncologic outcomes.

Oncologic outcomes in rectal cancer patients with a ≤1-cm distal resection margin

PURPOSE

Recently, common application of sphincter-saving resection in rectal cancer has led to acceptance of a 1-cm distal resection margin (DRM). The aim of this study was to evaluate oncologic outcomes of a DRM ≤1 cm in sphincter-saving resection for rectal cancer. The outcomes of a DRM ≤0.5 cm was also evaluated.

METHODS

We reviewed prospectively collected data from 415 patients who underwent sphincter-saving resection for mid and low rectal cancer between September 2006 and December 2012 at Korea University Anam Hospital. Patients were divided into two groups according to DRM measured in a formalin fixed specimen: ≤1 cm (n = 132) and >1 cm (n = 283). The DRM ≤1 cm group was divided into two subgroups: ≤0.5 cm (n = 45) and >0.5, ≤1 cm (n = 87).

RESULTS

Median follow-up periods were 47.2 months. The 5-year local recurrence rate was 8.8% in the DRM ≤1 cm group and 8.5% in the DRM >1 cm group (p = 0.630). The 5-year disease-free survival rate was 75.1 and 76.3% (p = 0.895), and the 5-year overall survival rate was 82.6 and 85.9% (p = 0.401), respectively. In subanalysis of the DRM ≤1 cm group, there was also no significant difference in the local recurrence and survival.

CONCLUSIONS

There was no significant difference in local recurrence and survival based on DRM length. We found that DRM length less than 1 cm was not a prognostic factor for local recurrence or survival.

Safety and Efficacy of Single-Incision Laparoscopic Totally Extraperitoneal Inguinal Hernia Repair: Comparative Study with Conventional Laparoscopic Totally Extraperitoneal Inguinal Hernia Repair

BACKGROUND

Inguinal hernia is a common disease treated with diverse methods. Nowadays, laparoscopic totally extraperitoneal approach is gaining its validity and shows favorable outcomes. However, single-incision laparoscopic surgery is also widening its applicable fields as a new technique. This study aimed to find whether single-incision laparoscopic total extraperitoneal inguinal hernia repair (SILTEP) is applicable compared to conventional laparoscopic total extraperitoneal hernia repair (CLTEP).

METHODS

We retrospectively reviewed 120 cases of SILTEP and 60 cases of CLTEP in Yonsei University Severance Hospital from January 2012 to December 2013. Each group was compared with patients' characteristics, operative details, and postoperative complications.

RESULTS

There were no statistical difference in patient age, sex, body mass index, American Society of Anesthesiologists score, hernia type, or location between SILTEP and CLTEP. In operative details, operation time (61.77 ± 16.48 minutes versus 77.83 ± 35.15 minutes, P = .001) was shorter in SILTEP. Postoperative complication rate has shown no statistical difference in SILTEP compared to CLTEP (n = 20, 16.7% versus n = 16, 26.7%, P = .114).

CONCLUSIONS

SILTEP is feasible and provides comparable postoperative outcomes compared to CLTEP. Although SILTEP has its own challenges for mastering the procedure, with some experiences, it is possible to operate as well as CLTEP.

Robotic rectal cancer surgery: literature review and perspective

Surgical treatment of patients with rectal cancer is challenging. The concept of robotic surgery is attractive and has earned considerable interest after its successful implementation in the fields of urology and gynecology. Recently, robotic surgery for rectal cancer with total mesorectal excision (TME) has also obtained an increasing amount of attention in the colorectal field. In this review, we introduce the commonly performed methods of robotic rectal surgery and discuss results to date and future perspectives.

NAG-1/GDF15 accumulates in the nucleus and modulates transcriptional regulation of the Smad pathway

Protein dynamics, modifications, and trafficking are all processes that can modulate protein activity. Accumulating evidence strongly suggests that many proteins play distinctive roles dependent on cellular location. Nonsteroidal anti-inflammatory drug activated gene-1 (NAG-1) is a TGF-β superfamily protein that plays a role in cancer, obesity, and inflammation. NAG-1 is synthesized and cleaved into a mature peptide, which is ultimately secreted into the extracellular matrix (ECM). In this study, we have found that full-length NAG-1 is expressed in not only the cytoplasm and ECM, but also in the nucleus. NAG-1 is dynamically moved to the nucleus, exported into cytoplasm, and further transported into the ECM. We have also found that nuclear NAG-1 contributes to inhibition of the Smad pathway by interrupting the Smad complex. Overall, our study indicates that NAG-1 is localized in the nucleus and provides new evidence that NAG-1 controls transcriptional regulation in the Smad pathway.

Short and long-term outcomes of robotic versus laparoscopic total mesorectal excision for rectal cancer: a case-matched retrospective study

The true benefits of robotic surgery are controversial, and whether robotic total mesorectal excision (R-TME) can be justified as a standard treatment for rectal cancer patients needs to be clarified. This case-matched study aimed to compare the postoperative complications and short- and long-term outcomes of R-TME and laparoscopic TME (L-TME) for rectal cancer.Among 1029 patients, we identified 278 rectal cancer patients who underwent R-TME. Propensity score matching was used to match this group with 278 patients who underwent L-TME.The mean follow-up period was similar between both groups (L-TME vs R-TME: 52.5 ± 17.1 vs 51.0 ± 13.1 months, P = 0.253), as were patient characteristics. The operation time was significantly longer in the R-TME group than in the L-TME group (361.6 ± 91.9 vs 272.4 ± 83.8 min; P < 0.001), whereas the conversion rate, length of hospital stay, and recovery of pain and bowel motility were similar between both groups. The rates of circumferential resection margin involvement and early complications were similar between both groups (L-TME vs R-TME: 4.7% vs 5.0%, P = 1.000; and 23.7% vs 25.9%, P = 0.624, respectively), as were the 5-year overall survival, disease-free survival, and local recurrence rates (93.1% vs 92.2%, P = 0.422; 79.6% vs 81.8%, P = 0.538; 3.9% vs 5.9%, P = 0.313, respectively).The oncologic quality, short- and long-term outcomes, and postoperative morbidity in the R-TME group were comparable with those in the L-TME group.

Reduced-port laparoscopic surgery for a tumor-specific mesorectal excision in patients with colorectal cancer: initial experience with 20 consecutive cases

Purpose

Single-port plus one-port, reduced-port laparoscopic surgery (RPLS) may decrease collisions between laparoscopic instruments and the camera in a narrow, bony, pelvic cavity while maintaining the cosmetic advantages of single-incision laparoscopic surgery. The aim of this study is to describe our initial experience with and to assess the feasibility and safety of RPLS for tumor-specific mesorectal excisions (TSMEs) in patients with colorectal cancer.

Methods

Between May 2010 and August 2012, RPLS for TSME was performed in 20 patients with colorectal cancer. A single port with four channels through an umbilical incision and an additional port in the right lower quadrant were used for RPLS.

Results

The median operation time was 231 minutes (range, 160-347 minutes), and the estimated blood loss was 100 mL (range, 50-500 mL). We transected the rectum with one laparoscopic stapler in 17 cases (85%). The median time to soft diet was 4 days (range, 3-6 days), and the length of hospital stay was 7 days (range, 5-45 days). The median total number of lymph nodes harvested was 16 (range, 7-36), and circumferential resection margin involvement was found in 1 case (5%). Seven patients (35%) developed postoperative complications, and no mortalities occurred within 30 days. During the median follow-up period of 20 months (range, 12-40 months), liver metastasis occurred in 1 patient 10 months after surgery, and local recurrence was nonexistent.

Conclusion

RPLS for TSME in patients with colorectal cancer is technically feasible and safe without compromising oncologic safety. However, further studies comparing RPLS with a conventional, laparoscopic low-anterior resection are needed to prove the advantages of the RPLS procedure.

Minimally invasive versus open total mesorectal excision for rectal cancer: Long-term results from a case-matched study of 633 patients

BACKGROUND

This study compared the long-term oncologic outcomes of patients with rectal cancer who underwent either laparoscopic or robotic total mesorectal excision (TME) via minimally invasive surgery (MIS) to those patient who underwent open TME.

METHODS

This study was a retrospective, case-control study; patients in the 2 groups were matched according to age, sex, MIS vs open operation, body mass index, tumor location, pathologic TNM stage (ie, tumor-node-metastasis), neoadjuvant treatment, and adjuvant treatment.

RESULTS

A total of 633 patients (MIS, n = 211; open, n = 422) were assessed. The median follow-up period was 64 (2-124) months. Patient characteristics did not differ between the groups. Overall postoperative complication rates did not differ between the groups (16.0% [MIS]; 17.0% [open]; P = .76). Rates of the involvement of the circumferential resection margin did not differ between the groups (4.0% [MIS]; 5.0% [open]; P = .84). The 5-year overall survival, disease-specific survival, disease-free survival, and local recurrence rates were not different between the MIS and open groups (overall survival = 88.4% vs 85.3%, P = .23; disease-specific survival = 88.8% vs 87.4%, P = .53, disease-free survival = 80.7% vs 78.4%, P = .74; local recurrence = 5.7% vs 5.1%, P = .95). In subgroup analysis, no differences were found in terms of the long-term, oncologic outcomes, oncologic adequacy, and postoperative complications among 3 groups.

CONCLUSION

We found no differences in the oncologic outcomes between MIS and open surgery, suggesting that MIS for rectal cancer is a safe option for rectal cancer that does not increase the risk of serious complications.

Clinical implications from a single-center study of colorectal adenocarcinoma in transplant recipients

BACKGROUND

With the increasing burden of organ transplant recipients and improvements in allograft outcome, the incidence of neoplasms rising from these patients is an important issue.

OBJECTIVE

In this study, we investigated transplant recipients with colorectal cancer to determine its incidence, clinicopathological characteristics, and prognosis.

METHODS

The database of Severance Hospital was queried for all cases of colorectal adenocarcinoma among transplant recipients from August 2005 to January 2013.

RESULTS

A total of 29 patients were diagnosed with colorectal adenocarcinoma after transplantation, and the median age at diagnosis was 58.6 years. As for primary tumor stage, 17 (58.6%) patients had stage ≥3, and distant metastasis was found in 10 (34.4%) patients. The mean time from transplantation to tumor detection was 13.7 years. The median disease-free survival was 11.0 months and the median overall survival (OS) was 18.1 months. In multivariate analysis of prognostic factors for OS, surgical resection was a positive prognostic factor (HR 1.357, p = 0.010) and the presence of distant metastasis at diagnosis was a negative prognostic factor (HR 1.047, p = 0.006).

CONCLUSION

The behavior of colorectal cancer in posttransplant patients is more aggressive and refractory to treatment. A separate guideline for the colorectal screening program for the posttransplant patients needs to be established.

Oncologic outcomes of single-incision versus conventional laparoscopic anterior resection for sigmoid colon cancer: a propensity-score matching analysis

BACKGROUND

The aim of this study was to investigate oncologic outcomes, as well as perioperative and pathologic outcomes, of single-incision laparoscopic anterior resection (SILAR) compared with conventional laparoscopic anterior resection (CLAR) for sigmoid colon cancer using propensity-score matching analysis.

METHODS

From July 2009 through April 2012, a total of 407 patients underwent laparoscopic anterior resection for sigmoid colon cancer. Data on short- and long-term outcomes were collected prospectively and reviewed. Propensity-score matching was applied at a ratio of 1:2 comparing the SILAR (n = 60) and CLAR (n = 120) groups.

RESULTS

There was no difference in operation time, estimated blood loss, time to soft diet, and length of hospital stay; however, the SILAR group showed less pain on postoperative day 2 (mean 2.6 vs. 3.6; p = 0.000) and shorter length of incision (3.3 vs. 7.7 cm; p = 0.000) compared with the CLAR group. Morbidity, mortality, and pathologic outcomes were similar in both groups. The 3-year overall survival rates were 94.5 versus 97.1% (p = 0.223), and disease-free survival rates were 89.5 versus 87.4% (p = 0.751) in the SILAR and CLAR groups, respectively.

CONCLUSION

The long-term oncologic outcomes, as well as short-term outcomes, of SILAR are comparable with those of CLAR. Although SILAR might have some technical difficulties, it appears to be a safe and feasible option, with better cosmetic results.

Robotic left colon cancer resection: a dual docking technique that maximizes splenic flexure mobilization

BACKGROUND

Techniques for robotic resection of the left colon are not well defined and have not been widely adopted due to limited range of motion of the robotic arms. We have developed a dual docking technique for both the splenic flexure and the pelvis. We report our initial experience of robotic left colectomy using this technique for left-sided colon cancer.

METHODS

The study group comprised 61 patients who underwent robotic left colon cancer resection using our dual docking technique between July 2008 and January 2013. Operations comprised two stages: colon mobilization (stage 1) followed by pelvic dissection (stage 2). After completion of stage 1, the robot arms were undocked and the operating table was rotated 60° counterclockwise until a 45° angle was created between the patient cart and the operating table.

RESULTS

All 61 procedures were technically successful without the need for conversion to laparoscopic or open surgery. Median total operation, 1st docking, and 2nd docking times were 227 min (range, 137-653 min), 4 min (range, 3-8 min), and 3 min (range, 3-9 min), respectively. Estimated blood loss was 20 ml (range, 20-2,000 ml). Median time to soft diet was 2 days (range, 2-12 days) and median length of hospital stay was 7 days (range, 4-20 days). Median total number of lymph nodes harvested was 17 (range, 3-61). According to the Clavien-Dindo classification, the numbers of complications for grades 1, 2, 3a, 3b, and 4 were 10, 2, 3, 3, and 1. There was no mortality within 30 days.

CONCLUSIONS

Robotic left colon cancer resection using our dual docking technique is safe and feasible. This procedure can maximize splenic mobilization in robotic colorectal surgery.

The clinical features and optimal treatment of anorectal malignant melanoma

Anorectal malignant melanoma (AMM) is a very rare and aggressive disease. The purpose of this article is to review the clinical features of AMM, to understand treatment options, and optimal therapy by reviewing pertinent literature. Traditionally an abdominoperineal resection (APR) sacrificing the anal sphincter has been performed for radical resection of cancer, but recently, wide excision of AMM is attempted since quality of life after surgery is an important issue. Some authors reported that there was no difference in five-year survival between the patient who underwent an APR and wide excision. The goal of both APR and wide excision was to improve survival with R0 resection. Adjuvant chemoradiation therapy can be performed to achieve an R0 resection. AMM shows very poor prognosis. At this time, research on AMM is insufficient to suggest a treatment guideline. Thus, treatment options, and a therapeutic method should be selected carefully.

Sarcopenia and sarcopenic obesity and their association with dyslipidemia in Korean elderly men: the 2008-2010 Korea National Health and Nutrition Examination Survey

BACKGROUND

Recently, aging has been shown to be associated with sarcopenic obesity (SO), of which decreased muscle mass and increased fat mass are features. Sarcopenia and obesity alone are known to be associated with abnormal lipid metabolism. However, it remains unclear whether SO has greater adverse effects on dyslipidemia than on sarcopenia or obesity alone.

AIM

We aimed to investigate the association between SO and dyslipidemia in elderly Koreans.

SUBJECTS AND METHODS

This study was based on data collected during the 2008-2010 Korea National Health and Nutrition Examination Survey. We included 1,466 men and 2,017 women aged 65 years and over. Sarcopenia was indicated in participants with height- or weight-adjusted appendicular skeletal muscle that was 1 standard deviation below the sex-specific mean for the young reference group, and obesity was defined as a body mass index ≥ 25 kg/m(2). Dyslipidemia was defined according to the National Cholesterol Education Program-Adult Treatment Panel III.

RESULTS

After adjusting for confounding factors, the SO group had a higher risk for dyslipidemia [odds ratio (OR) 2.82 (95 % confidence interval 1.76-4.51)] than the obese group [2.12 (1.11-4.07)] and sarcopenic group [1.46 (1.01-2.11)] (p < 0.001) only in men. Furthermore, the SO group in men had the highest OR for hypercholesterolemia, hypertriglyceridemia, hypo-high-density lipoprotein cholesterolemia, hyper-low-density lipoprotein cholesterolemia, and a high ratio of triglyceride to high-density lipoprotein cholesterol even after further adjustments.

CONCLUSIONS

In Korean elderly men, SO was associated with an increased risk for dyslipidemia compared with sarcopenia or obesity alone.

NAG-1/GDF-15 prevents obesity by increasing thermogenesis, lipolysis and oxidative metabolism

Objective

Obesity is a major health problem associated with high morbidity and mortality. NSAID activated gene, (NAG-1) is a TGF-β superfamily member reported to alter adipose tissue levels in mice. We investigated whether hNAG-1 acts as a regulator of adiposity and energy metabolism.

Design/Subjects

hNAG-1 mice, ubiquitously expressing hNAG-1, were placed on a control or high fat diet (HFD) for 12 weeks. hNAG-1 expressing B16/F10 melanoma cells were used in a xenograft model to deliver hNAG-1 to obese C57BL/6 mice.

Results

As compared to wild-type littermates, transgenic hNAG-1 mice have less white fat and brown fat despite equivalent food intake, improved glucose tolerance, lower insulin levels and are resistant to dietary- and genetic-induced obesity. hNAG-1 mice are more metabolically active with higher energy expenditure. Obese C57BL/6 mice treated with hNAG-1 expressing xenografts show decreases in adipose tissue and serum insulin levels. hNAG-1 mice and obese mice treated with hNAG-1 expressing xenografts show increased thermogenic gene expression (UCP1, PGC1α, ECH1, Cox8b, Dio2, Cyc1, PGC1β, PPARα, Elvol3) in brown adipose tissue (BAT) and increased expression of lipolytic genes (Adrb3, ATGL, HSL) in both white adipose tissue (WAT) and BAT, consistent with higher energy metabolism

Conclusion

hNAG-1 modulates metabolic activity by increasing the expression of key thermogenic and lipolytic genes in BAT and WAT. hNAG-1 appears to be a novel therapeutic target in preventing and treating obesity and insulin resistance.

Comparative study of oncologic outcomes for laparoscopic vs. open surgery in transverse colon cancer

Purpose

Laparoscopic resection for transverse colon cancer is a technically challenging procedure that has been excluded from various large randomized controlled trials of which the long-term outcomes still need to be verified. The purpose of this study was to evaluate long-term oncologic outcomes for transverse colon cancer patients undergoing laparoscopic colectomy (LAC) or open colectomy (OC).

Methods

This retrospective review included patients with transverse colon cancer who received a colectomy between January 2006 and December 2010. Short-term and five-year oncologic outcomes were compared between these groups.

Results

A total of 131 patients were analyzed in the final study (LAC, 84 patients; OC, 47 patients). There were no significant differences in age, gender, body mass index, tumor location, operative procedure, or blood loss between groups, but the mean operative time in LAC was significantly longer (LAC, 246.8 minutes vs. OC, 213.8 minutes; P = 0.03). Hospital stay was much shorter for LAC than OC (9.1 days vs. 14.5 days, P < 0.01). Postoperative complication rates were not statistically different between the two groups. In terms of long-term oncologic data, the 5-year disease-free survival and overall survival were not statistically different between both groups, and subgroup analysis according to cancer stage also revealed no differences.

Conclusion

LAC for transverse colon cancer is feasible and safe with comparable short- and long-term outcomes.

Feasibility and safety of laparoscopic resection following stent insertion for obstructing left-sided colon cancer

Purpose

The aim of this study was to assess the feasibility and safety of laparoscopic resection following the insertion of self-expanding metallic stents (SEMS) for the treatment of obstructing left-sided colon cancer.

Methods

Between October 2006 and December 2012, laparoscopic resection following SEMS insertion was performed in 54 patients with obstructing left-sided colon cancer.

Results

All 54 procedures were technically successful without the need for conversion to open surgery. The median interval from SEMS insertion to laparoscopic surgery was 9 days (range, 3-41 days). The median surgery time was 200 minutes (range, 57-444 minutes), and estimated blood loss was 50 mL (range, 10-3,500 mL). The median time to soft diet was 4 days (range, 2-8 days) and possible length of stay (hypothetical length of stay according to the discharge criteria) was 7 days (range, 4-22 days). The median total number of lymph nodes harvested was 23 (range, 8-71) and loop ileostomy was performed in 2 patients (4%). Six patients (11%) developed postoperative complications: 2 patients with anastomotic leakages, 1 with bladder leakage, and 3 with ileus. There was no mortality within 30 days.

Conclusion

The present study shows that the presence of a SEMS does not compromise the laparoscopic approach. Laparoscopic resection following stent insertion for obstructing left-sided colon cancer could be performed with a favorable safety profile and short-term outcome. Large-scale comparative studies with long-term follow-up are needed to demonstrate a significant benefit of this approach.

Virtual reality training improves da Vinci performance: a prospective trial

INTRODUCTION

The DV-Trainer™ (a virtual reality [VR] simulator) (Mimic Technologies, Inc., Seattle, WA) is one of several different robotic surgical training methods. We designed a prospective study to determine whether VR training could improve da Vinci(®) Surgical System (Intuitive Surgical, Inc., Sunnyvale, CA) performance.

SUBJECTS AND METHODS

Surgeons (n=12) were enrolled using a randomized protocol. Groups 1 (VR training) and 2 (control) participated in VR and da Vinci exercises. Participants' time and moving distance were combined to determine a composite score: VR index=1000/(time×moving distance). The da Vinci exercises included needle control and suturing. Procedure time and error were measured. A composite index (DV index) was computed and used to measure da Vinci competency. After the initial trial with both the VR and da Vinci exercises, only Group 1 was trained with the VR simulator following our institutional curriculum for 3 weeks. All members of both groups then participated in the second trial of the VR and da Vinci exercises and were scored in the same way as in the initial trial.

RESULTS

In the initial trial, there was no difference in the VR index (Group 1 versus Group 2, 8.9 ± 3.3 versus 9.4 ± 3.7; P=.832) and the DV index (Group 1 versus Group 2, 3.85 ± 0.73 versus 3.66 ± 0.65; P=.584) scores between the two groups. At the second time point, Group 1 showed increased VR index scores in comparison with Group 2 (19.3 ± 4.5 versus 9.7 ± 4.1, respectively; P=.001) and improved da Vinci performance skills as measured by the DV index (5.80 ± 1.13 versus 4.05 ± 1.03, respectively; P=.028) and by suturing time (7.1 ± 1.54 minutes versus 10.55 ± 1.93 minutes, respectively; P=.018).

CONCLUSIONS

We found that VR simulator training can improve da Vinci performance. VR practice can result in an early plateau in the learning curve for robotic practice under controlled circumstances.

Intraoperative near infrared fluorescence imaging in robotic low anterior resection: three case reports

The recent introduction of an intraoperative near infrared fluorescence (INIF) imaging system installed on the da Vinci Si® robotic system has enabled surgeons to identify intravascular NIF signals in real time. This technology is useful in identifying hidden vessels and assessing blood supply to bowel segments. In this study, we report 3 cases of patients with rectal cancer who underwent robotic low anterior resection (LAR) with INIF imaging for the first time in Asia. In September 2012, robotic- assisted rectal resection with INIF imaging was performed on three consecutive rectal cancer patients. LAR was performed in 2 cases, and abdominoperineal resection was performed in the third case. INIF imaging was used to identify the left colic branch of the inferior mesenteric artery and to assess blood supply to the distal rectum. We evaluated the utility of INIF imaging in performing robotic-assisted colorectal procedures. Our preliminary results suggest that this technique is safe and effective, and that INIF imaging may be a useful tool to colorectal surgeons.

Robotic versus laparoscopic coloanal anastomosis with or without intersphincteric resection for rectal cancer

Robotic surgery is increasingly used in the field of rectal cancer surgery. This study aimed to compare the short- and long-term outcomes between robotic and laparoscopic ultralow anterior resection (uLAR) and coloanal anastomosis (CAA). Between January 2007 and December 2010, a retrospective chart review was performed for all patients with low rectal cancer who underwent curative uLAR and CAA with or without intersphincteric resection using either a robotic or a laparoscopic approach. The study excluded patients with tumors invading the levator ani or external sphincter, patients with T4 cancers invading the prostate or vagina, and patients for whom an open approach was used. Patients' short- and long-term outcomes were evaluated. This study enrolled 84 consecutive patients (47 in the robotic group and 37 in the laparoscopic group). The patient characteristics and operative data did not differ significantly between the groups except for the rate of conversion to open surgery (robot, 2.1 % vs laparoscopy, 16.2 %; p = 0.02). The postoperative outcomes also were similar in the two groups, but the hospital stay was shorter in the robotic group than in the laparoscopic group (robot, 9 days vs laparoscopy, 11 days; p = 0.011). No postoperative mortality occurred. The median follow-up period was 31.5 months. No difference was shown in local recurrence, 3-year overall survival, or disease-free survival between the two groups. Robotic uLAR and CAA with or without ISR is a safe and feasible surgical approach with a lower conversion rate, a shorter hospital stay, and similar oncologic outcomes compared with a laparoscopic approach. Further prospective and case-control cohort studies with longer follow-up periods are required.

Relationship between diversion colitis and quality of life in rectal cancer

AIM: To investigated the incidence of diversion colitis (DC) and impact of DC symptoms on quality of life (QoL) after ileostomy reversal in rectal cancer.

METHODS: We performed a prospective study with 30 patients who underwent low anterior resection and the creation of a temporary ileostomy for the rectal cancer between January 2008 and July 2009 at the Department of Surgery, Korea University Anam Hospital. The participants totally underwent two rounds of the examinations. At first examination, endoscopies, tissue biopsies, and questionnaire survey about the symptom were performed 3-4 mo after the ileostomy creations. At second examination, endoscopies, tissue biopsies, and questionnaire survey about the symptom and QoL were performed 5-6 mo after the ileostomy reversals. Clinicopathological data were based on the histopathological reports and clinical records of the patients.

RESULTS: At the first examination, all of the patients presented with inflammation, which was mild in 15 (50%) patients, moderate in 11 (36.7%) and severe in 4 (13.3%) by endoscopy and mild in 14 (46.7%) and moderate in 16 (53.3%) by histology. At the second examination, only 11 (36.7%) and 17 (56.7%) patients had mild inflammation by endoscopy and histology, respectively. There was no significant difference in DC grade between the endoscopic and the histological findings at first or second examination. The symptoms detected on the first and second questionnaires were mucous discharge in 12 (40%) and 5 (17%) patients, bloody discharge in 5 (17%) and 3 (10%) patients, abdominal pain in 4 (13%) and 2 (7%) patients and tenesmus in 9 (30%) and 5 (17%) patients, respectively. We found no correlation between the endoscopic or histological findings and the symptoms such as mucous discharge, bleeding, abdominal pain and tenesmus in both time points. Diarrhea was detected in 9 patients at the second examination; this number correlated with the severity of DC (0%, 0%, 66.7%, 33.3% vs 0%, 71.4%, 23.8%, 4.8%, P = 0.001) and the symptom-related QoL (r = -0.791, P < 0.001).

CONCLUSION: The severity of DC is related to diarrhea after an ileostomy reversal and may adversely affect QoL.

Robotic vs laparoscopic resection of rectal cancer: short-term outcomes of a case-control study

PURPOSE

Few data are available to compare robotic and laparoscopic techniques for rectal cancer resection. This study aimed to compare short-term outcomes with these procedures performed by a single surgeon.

METHODS

Using data from a prospective database of all operations performed in our department, we retrospectively analyzed data from 117 robotic and 102 laparoscopic rectal cancer resections performed by one surgeon between July 2007 and October 2009. Robotic resection was offered as a treatment option to all patients, and laparoscopic resection was performed for those who refused. This analysis was a case-control study in which patients in the 2 groups were matched according to tumor location, staging, age, and gender.

RESULTS

A total of 118 patients (59 matched pairs) were included in the study. No differences were found between robotic and laparoscopic resection regarding number of lymph nodes harvested (median, 20; interquartile range, 12-27 vs 21; 14-28; P = .702) or distal resection margin (median, 2.2 cm; interquartile range, 1.5-3.0 cm vs 2.0; 1.2-3.5 cm; P = .865). The circumferential margin was positive (≤ 2 mm) in 1 patient in the robotic group but in none of the laparoscopic group (P > .999). Operating time was longer in the robotic group than in the laparoscopic group (P < .0001). No conversions were necessary in the robotic group, but 2 cases (3.4%) were converted to open surgery in the laparoscopic group (P = .496). No differences were observed between groups regarding postoperative complications. Operative mortality was zero in both groups. During a median follow-up of 15.0 months, 2 cases of distant metastases and 1 case of local recurrence were observed in each group.

CONCLUSIONS

Robotic rectal cancer resection can be safely performed by experienced laparoscopic surgeons, with acceptable short-term outcomes comparable to those for laparoscopic resection.

Activating transcription factor 2 (ATF2) controls tolfenamic acid-induced ATF3 expression via MAP kinase pathways

Tolfenamic acid (TA) is a non-steroidal anti-inflammatory drug associated with anti-tumorigenic and pro-apoptotic properties in animal and in vitro models of cancer. However, the underlying cellular mechanisms by which TA exerts its effects are only partially understood. Activating transcription factor 3 (ATF3) is a member of the ATF/CREB subfamily of the basic region-leucine zipper family and has been known as a tumor suppressor in human colorectal cancer cells. The present study was performed to observe whether ATF3 mediates TA-induced apoptosis and to elucidate the molecular mechanism of ATF3 transcription induced by TA. TA treatment and ectopic expression of ATF3 increased apoptosis whereas knockdown of ATF3 resulted in significant repression of TA-activated apoptosis. The TA treatment also induced ATF3 promoter activity. Internal deletion and point mutation of the predicted ATF/C/EBP binding site in ATF3 promoter abolished luciferase activation by TA. Overexpression of ATF2 resulted in significant increase of ATF3 promoter activity, and electrophoretic mobility shift assay identified this region as a core sequence to which ATF2 binds. TA treatment resulted in an increase of ATF2 phosphorylation, which was followed by a subsequent increase of ATF3 transcription. Knockdown of ATF2 abolished TA-induced ATF3 expression. We further provide evidence that TA leads to increases of phospho-p38 MAPK, JNK, and ERK levels. Inhibition of these pathways using selective inhibitors and dominant negative constructs ameliorated TA-induced ATF3 expression and promoter activities. The current study demonstrates that TA stimulates ATF3 expression and subsequently induces apoptosis. These pathways are mediated through phosphorylation of ATF2, which is mediated by p38 MAPK, JNK, and ERK-dependent pathways.

Evaluation of eicosanoids and NSAIDs as PPARgamma ligands in colorectal carcinoma cells

The activation of peroxisome proliferator activated receptor gamma (PPARgamma) may play a role in the control of colorectal carcinogenesis. The expression of PPARgamma was examined by Western blotting in human colorectal tumors and matched normal adjacent tissues, as well as in various colorectal carcinoma cell lines. In the tissues, the expression of PPARgamma was elevated in tumors relative to the adjacent normal tissues. Each colorectal carcinoma cell line expressed PPARgamma. The ability of various eicosanoids to bind PPARgamma in colorectal carcinoma cells was investigated using luciferase reporter assays. The well-known PPARgamma ligands, troglitazone and 15-deoxy-Delta(12,14)-prostaglandin J(2) strongly induced PPARgamma binding activity. Products of lipoxygenases displayed moderate binding activity, while other prostaglandins and fatty acids displayed little or no reporter activation. The activation of PPARgamma by 13(S)-HODE, the major metabolite of 15-lipoxygenase-1 from linoleic acid, was concentration dependent reaching maximum at 10 micro M (35-fold activation). The endogenous production of 13(S)-HODE by expression of 15-LO-1 did not activate PPARgamma. The ability of various nonsteroidal anti-inflammatory drugs (NSAIDs) to induce PPARgamma activation was also evaluated. The conventional NSAIDs that inhibit both cyclooxygenases (COX-1 and COX-2) also induced PPARgamma binding activity. In general, however, neither COX-1- nor COX-2-specific inhibitors induced the activation of PPARgamma. Taken together, the metabolites of 15-lipoxygenase and the conventional NSAIDs were confirmed as exogenous ligands for PPARgamma in colorectal carcinoma cells.

Functional characterization of cyclooxygenase-2 polymorphisms

Cyclooxygenases (COX)-1 and -2 are the key enzymes in the conversion of arachidonic acid to prostaglandins. COX-2 appears to play an emerging role in inflammation and carcinogenesis. Nonsteroidal anti-inflammatory drugs (NSAIDs) are used for the treatment of numerous diseases and reduce the risk of developing colorectal cancer. Polymorphisms in the COX-2 gene could alter enzyme expression, function, and/or the response to NSAIDs. Therefore, they could modify individual risks for developing cancer and other diseases or the occurrence of side effects or sensitivity toward selective or nonselective COX inhibitors. We sequenced the COX-2 gene of 72 individuals and identified rare polymorphisms in the promoter and the coding region. A COX-2 molecular model was used to locate the coding region polymorphisms relative to functional sites in the protein, and the COX-2 V511A polymorphism was very near to the active site. This variant protein was expressed, and function was evaluated, but no difference was detected in metabolism of the COX-2 substrates, arachidonic acid, linoleic acid, and 2-arachidonyl glycerol, compared with the wild type. The Km values for arachidonic acid showed no differences between the COX-2 wild type and V511A mutant. Inhibition with selective or nonselective COX inhibitors was essentially the same for the two enzymes. The absence of functionally important polymorphisms in the COX-2 gene may suggest that there has been selective pressure against those single nucleotide polymorphisms because of the critical role of this enzyme in maintenance of homeostasis.

Expression of Gab1 lacking the pleckstrin homology domain is associated with neoplastic progression

An in vitro transformation system of carcinogen-treated Syrian hamster embryo (SHE) cell cultures represents multistep genetic and nongenetic changes that develop during the neoplastic progression of normal cells to tumor cells in vivo. During this neoplastic progression, SHE cells demonstrate an altered response to epidermal growth factor (EGF). In the present report, we examined the role of the adapter protein Gab1 (Grb2-associated binder-1) in the neoplastic progression of SHE cells. We used two asbestos-transformed SHE cell clones in different neoplastic stages: a 10W+8 clone, which is immortal and retains the ability to suppress the tumorigenicity of tumor cells in cell-cell hybrid experiments, and a 10W-1 clone, which has lost this tumor suppressor ability. 10W+8 cells expressed full-length 100-kDa Gab1 and associated 5.2-kb mRNA. Upon repeated cell passaging, 10W-1 cells showed increasing expression of a novel 87-kDa form of Gab1 as well as 4.6-kb mRNA with diminishing expression of the original 100-kDa Gab1. cDNA encoding the 87-kDa Gab1 predicts a form of Gab1 lacking the amino-terminal 103 amino acids (Gab1(Delta1-103)), which corresponds to loss of most of the pleckstrin homology (PH) domain. Gab1(Delta1-103) retains the ability to be phosphorylated in an EGF-dependent manner and to associate with the EGF receptor and SHP-2 upon EGF stimulation. The endogenous expression of Gab1(Delta1-103) in 10W-1 cells appeared closely related to EGF-dependent colony formation in soft agar. Moreover, transfection and expression of Gab1(Delta1-103), but not Gab1, in 10W+8 cells enhanced their EGF-dependent colony formation in soft agar. These results demonstrate that Gab1 is a target of carcinogen-induced transformation of SHE cells and that the expression of a Gab1 variant lacking most of the PH domain plays a specific role in the neoplastic progression of SHE cells.

Molecular cloning and characterization of human nonsteroidal anti-inflammatory drug-activated gene promoter. Basal transcription is mediated by Sp1 and Sp3

Nonsteroidal anti-inflammatory drug-activated gene (NAG-1) is known to be associated with anti-tumorigenic activity and belongs to the transforming growth factor-beta superfamily. In the present study, we cloned the promoter region (-3500 to +41) and investigated the transcriptional regulatory mechanisms of the basal expression of the human NAG-1 gene. Several potential transcription factor-binding sites in this region were identified. Based on the results from clones of nested deletions, the construct between -133 and +41 base pairs contains three Sp1-binding sites (Sp1-A, Sp1-B, and Sp1-C), which confer basal transcription specific activity of NAG-1 expression. When the Sp1-C site was mutated (GG to TT), a 60-80% decrease in promoter activity was observed in HCT-116 cells. Gel shift, co-transfection, and chromatin immunoprecipitation assays showed that the Sp transcription factors bind to the Sp1-binding sites and transactivate NAG-1 expression. In addition, chicken ovalbumin upstream promoter-transcription factor 1 can interact with the C-terminal region of Sp1 and Sp3 proteins and induce NAG-1 promoter activity through Sp1 and Sp3 transcription factors. These results identify the critical regulatory regions for the human NAG-1 basal promoter. Furthermore, the results suggest that the level of expression of the NAG-1 gene will depend on the availability of Sp proteins and on co-factors such as chicken ovalbumin upstream promoter-transcription factor 1.

Inhibition of lipid peroxidation and oxidative DNA damage by Ganoderma lucidum

Reactive oxygen species (ROS), such as superoxide anions and hydroxyl radicals, are associated with carcinogenesis and other pathophysiological conditions. Therefore, elimination or inactivation of ROS or inhibition of their excess generation may be beneficial in terms of reducing the risk for cancer and other diseases. Ganoderma lucidum has been used in traditional oriental medicine and has potential antiinflammatory and antioxidant activities. In the present study, we tested the amino-polysaccharide fraction (designated as 'G009') from Ganoderma lucidum for the ability to protect against oxidative damage induced by ROS. G009 significantly inhibited iron-induced lipid peroxidation in rat brain homogenates and showed a dose-dependent inactivation of hydroxyl radicals and superoxide anions. It also reduced strand breakage in phiX174 supercoiled DNA caused by UV-induced photolysis of hydrogen peroxide and attenuated phorbol ester-induced generation of superoxide anions in differentiated human promyelocytic leukaemia (HL-60) cells. These findings suggest that G009 from Ganoderma lucidum possesses chemopreventive potential.

Effect of PPAR activators on cytokine-stimulated cyclooxygenase-2 expression in human colorectal carcinoma cells

Cyclooxygenase-2 (COX-2) expression is up-regulated in colorectal cancer tissue. Peroxisome proliferator-activated receptors (PPARs) are expressed in human colorectal tissue and activation of PPARs can alter COX-2 expression. In macrophages, activation of PPARs down-regulates COX-2 expression. We examined the effect of PPARalpha and PPARgamma ligands on untreated and TNF-alpha-induced COX-2 expression in the human colorectal epithelial cell line HT-29. The expression of PPARalpha and PPARgamma was confirmed in these cells. TNF-alpha, an inflammatory cytokine, increased COX-2 expression via the NFkappaB pathway. In the absence of TNF-alpha, WY14643 (PPARalpha activator) caused an increase, while BRL49653 (PPARgamma activator) did not alter COX-2 expression. When HT-29 cells were incubated with TNF-alpha and WY14643, a further increase in COX-2 expression was detected. Incubation with TNF-alpha and BRL49653 caused an additional twofold increase in COX-2 expression. Our results suggest that both PPARalpha signaling and TNF-alpha signaling increase COX-2 expression by independent pathways, while PPARgamma stimulates COX-2 expression by up-regulation of the TNF-alpha pathway.

Identification of epidermal growth factor receptor- Grb2-associated binder-1-SHP-2 complex formation and its functional loss during neoplastic cell progression

The adaptor protein Grb2-associated binder-1 (Gab1) is known to bind to the SHP-2 tyrosine phosphatase on epidermal growth factor (EGF) receptor stimulation. To clarify the roles of these two proteins in EGF receptor (EGFR) signaling and determine their possible alteration during neoplastic cell progression, we studied these proteins in a Syrian hamster embryo (SHE) cell line model of neoplastic progression. Specifically, we used asbestos-transformed SHE fibroblasts: the 10W+8 clone, which is immortal but nontumorigenic; and the 10W2T clone, which is tumorigenic. Gab1 was detected, and the EGF-dependent formation of the EGFR-Gab1-SHP-2 complex was observed in 10W+8 cells. After cloning hamster Gab1 cDNA, exogenous expression of Gab1 significantly enhanced EGF-dependent mitogenic activity in 10W+8 cells. On the other hand, Gab1 was not detected in 10W2T cells, and the EGF-dependent association of SHP-2 with EGFR was also absent. Exogenous Gab1 expression in transfected 10W2T cells restored the EGF-dependent association of SHP-2 with EGFR, although it only showed a marginal effect on EGF-dependent mitogenic activity. Thus, Gab1 plays a pivotal role in the EGFR signaling pathway via the formation of the EGFR-Gab1-SHP-2 complex, and alteration in the expression and function of Gab1 is implicated in the neoplastic progression of SHE cells.

Subgrouping persons with snoring and/or apnea by using anthropometric and cephalometric measures

Craniofacial and anthropometric characteristics are identified risk factors for obstructive sleep apnea syndrome (OSAS). Phase 1 of this study used cephalometric radiographs to record craniofacial measurements from 60 OSAS subjects with a respiratory disturbances index (RDI) of 20 or greater (group A) and 60 subjects with a history of loud snoring and an RDI less than 20 (group B). From this data set, a craniofacial risk index (CRI) was constructed using age, body mass index (BMI), and 14 cephalometric measures previously reported to be associated with OSAS. A separating boundary (CRIS) was established by using discriminant analysis to differentiate between the two groups. All measurements were determined by an investigator who was blinded to the subjects' RDI score. Phase 2 used a second sample of 19 group A and 47 group B subjects to test the ability of the CRI derived from the first sample to classify subjects in this second sample into the correct age group. The CRI was able to classify correctly 72.3% (34 of 47) of the group A subjects when all variables were used in the discriminant model. Using only four variables (age, BMI, hyoid mandibular plane distance, and tongue length) selected by the stepwise method, 72.3% (34 of 47) of the group B subjects and 78.7% of group A subjects were classified correctly. These results suggest that a stepwise CRI could be used to classify heterogeneous groups of individuals with increased RDI into subgroups with varying degrees of anatomic risk for disease. Such subgrouping by anatomic risk could be important in determining the pathophysiology of OSAS because it is likely that differences in upper airway anatomy among individuals interacts with a variety of other factors to produce clinical illness.

Cyclooxygenase inhibitors regulate the expression of a TGF-beta superfamily member that has proapoptotic and antitumorigenic activities

The antitumorigenic activity of nonsteroidal anti-inflammatory drugs (NSAIDs), cyclooxygenase (COX) inhibitors, is well established, but responsible molecular mechanisms are not fully understood. NSAIDs stimulate apoptosis by COX dependent and independent mechanisms in colorectal cells in culture. Identification of genes regulated by COX inhibitors could lead to a better understanding of their proapoptotic and anti-neoplastic activities. Using subtractive hybridization, a cDNA which was designated as NSAID activated gene (NAG-1) was identified from NSAID-treated HCT-116, human colorectal cells. NAG-1 has an identical sequence with a novel member of the TGF-beta superfamily that has 5 different names. In the HCT-116 cells, NAG-1 expression is increased and apoptosis is induced by treatment with some NSAIDs in a concentration and time-dependent manner. NAG-1 transfected cells exhibited increased basal apoptosis, increased response to NSAIDs and reduced soft agar cloning efficiency. Furthermore, transplantable tumors derived from NAG-1 transfected HCT-116 cells showed reduced tumorigenicity in athymic nude mice compared with vector-transfected HCT-116 cells. The increased NAG-1 expression by NSAIDs provides a suitable explanation for COX-independent apoptotic effects of NSAIDs in cultured cells. These data demonstrate that NAG-1 is an antitumorigenic and proapoptotic protein, and its regulation by COX inhibitors may provide new clues for explaining their proapoptotic and antitumorigenic activities.

Lack of cyclooxygenase-2 activity in HT-29 human colorectal carcinoma cells

Induction of cyclooxygenase-2 (COX-2) is an early event in the sequence of polyp formation to colon carcinogenesis. COX-2 is at elevated levels in human colorectal cancers and in tumors and polyps of mouse models of colorectal cancer. Mutation of the adenomatous polyposis coli (APC) gene is the initial event leading to colorectal cancer. Colorectal cells in culture which express mutant APC are often used to examine the association of COX-2 expression and apoptosis. The expression of full-length APC in HT-29 cells, a human colorectal carcinoma cell line which normally expresses truncated APC and highly expresses COX-2, inhibits cell growth through increased apoptosis and results in a down-regulation of COX-2 protein. In this report, we examine whether down-regulation of COX-2 is directly linked to the increase in apoptosis observed in these HT-29-APC cells. We present evidence that COX-2 and apoptosis are not linked since COX-2, although expressed, is catalytically inactive. Interestingly, the COX-2 cloned from HT-29 cells is catalytically active when transfected into HCT-116 cells, a colorectal cell line which normally does not express COX-2, but is not active in the HT-29 cell line itself.

The synaptic vesicle protein SV2 is complexed with an alpha5-containing laminin on the nerve terminal surface

Interactions between growing axons and synaptic basal lamina components direct the formation of neuromuscular junctions during nerve regeneration. Isoforms of laminin containing alpha5 or beta2 chains are potential basal lamina ligands for these interactions. The nerve terminal receptors are unknown. Here we show that SV2, a synaptic vesicle transmembrane proteoglycan, is complexed with a 900-kDa laminin on synaptosomes from the electric organ synapse that is similar to the neuromuscular junctions. Although two laminins are present on synaptosomes, only the 900-kDa laminin is associated with SV2. Other nerve terminal components are absent from this complex. The 900-kDa laminin contains an alpha5, a beta1, and a novel gamma chain. To test whether SV2 directly binds the 900-kDa laminin, we looked for interaction between purified SV2 and laminin-1, a laminin isoform with a similar structure. We find SV2 binds with high affinity to purified laminin-1. Our results suggest that a synaptic vesicle component may act as a laminin receptor on the presynaptic plasma membrane; they also suggest a mechanism for activity-dependent adhesion at the synapse.

Comparison of two dental devices for treatment of obstructive sleep apnea syndrome (OSAS)

Previous case reports have indicated dental devices can be an effective nonsurgical treatment for snoring and obstructive sleep apnea. This pilot study evaluated the effectiveness of two intraoral devices in reducing the Respiratory Disturbance Index (RDI) and Epworth Sleepiness Scale (ESS) scores in a group of 24 adult volunteers with a history of loud snoring. Subjects were randomly assigned to two groups. Twelve subjects were fitted with a dental device designed to increase vertical dimension and protrude the mandible (device A). The other 12 subjects received a different device designed to minimally increase vertical opening without protruding the mandible (device B). Unattended home sleep monitoring (Edentrace II Digital Recorder, Edentech Corp.) was used to compute RDI at two time periods: (T0) before using any dental device and (T1) while using a dental device 2 weeks after the initial delivery date. The mean RDI and ESS scores at T0 for subjects in the device A group were 35.6 +/- 28.4 and 12.0 +/- 3.9, respectively. Means for the same measures at T1 were 21.1 +/- 21.4 and 8.2 +/- 4.0. For subjects in the device B group, means for RDI and ESS scores at T0 were 36.5 +/- 43.7 and 13.0 +/- 4.5, the means at T1 were 46.8 +/- 47.0 and 12.5 +/- 5.7. The effectiveness of the two devices was estimated by comparing the difference in RDI scores from T0 to T1 for the 10 subjects who were using device A and completed the study and the 8 subjects who were using device B and completed the study. Six subjects withdrew for various reasons. From T0 to T1, device A reduced RDI scores in 9 of 10 subjects, with a mean reduction in RDI of 14.5 (p < or = 0.05) and in ESS score of 3.8 (p < or = 0.005). Device B showed no change or an increased RDI score in 8 of 8 subjects. Seven of the eight subjects who showed no improvement in RDI with device B were then fitted with device A. Four of these seven subjects showed a reduction in RDI and five showed a reduction in ESS after using device A for 2 weeks. The mean reduction in RDI and ESS was 2.4 +/- 19.8 and 2.4 +/- 3.0, respectively. Hence, we conclude that a dental device that advances the mandible and increases the vertical dimension to open the upper airway is more effective in reducing the number of apneic and snoring events during sleep than one which does not.

Multiple factors regulating the expression of human thromboxane synthase gene

Characterization of the 5.5 kb promoter of human thromboxane synthase (TS) gene revealed a proximal positive regulatory sequence (PPRS, -90 to -25 bp) and several distal repressive elements. The maximal promoter activity was found to reside within the first 285 bp, approximately 75% of which was contributed by the PPRS. The sequence between -365 and -665 bp exerted a strong repressive effect (approximately 55%) on reporter gene expression independent of orientation and position, consistent with properties expected for a silencer. The sequence upstream of -665 bp to -5.5 kb contains mainly repressive elements which further reduce the promoter activity by 30%. The 65 bp PPRS worked in an orientation-independent, but position-dependent, manner and could be further divided into two independent elements, PPRS1 (-90 to -50 bp) and PPRS2 (-50 to -25 bp). While similar nuclear factor(s) from different cell types interact with PPRS2, those interacting with PPRS1 exhibit cell specificity. Internal sequence deletion and oligonucleotide competition established that a binding sequence for NF-E2 in PPRS1 (-60 tgctgattcat -50) was important for enhancing TS promoter activity in HL-60 cells. The presence of NF-E2 mRNA in HL-60 cells was demonstrated by reverse-transcription PCR amplification of the cDNA and Northern blot analysis. A 9-fold transactivation of luciferase (luc) reporter gene expression had been detected when NF-E2 cDNA was co-expressed with a TS promoter/luc construct. Despite the fact that NF-E2 and the cis-elements could alter the efficiency of TS transcription, they were not sufficient for restricting cell-specific TS expression. Analysis of the methylation status at the TS promoter in several human cell lines reveals cell-specific patterns of methylation that might correlate with TS expression. Taken together, these results suggest that the expression of human TS gene is modulated by multiple factors including cis-elements, trans-activator(s), and possibly genomic methylation.

Genomic structure and polymorphism of the human thromboxane synthase-encoding gene

Thromboxane synthase (TS) is a cytochrome P-450 (CYP450) enzyme catalyzing the conversion of prostaglandin endoperoxide (PGH2) into thromboxane A2 (TxA2) which plays a crucial role in hemostasis and cardiovascular diseases. Twelve genomic clones containing the DNA encoding the human TS gene (hTS) were isolated and characterized to determine the exon/intron boundaries and restriction maps of the nearly contiguous structure of the gene. The hTS contains 13 exons spanning more than 150 kb. Its first five exons, divided by relatively large introns, spread over 100 kb, but encode less than one third of the full-length TS transcript. Southern analysis indicates that the human haploid genome contains a single copy of the TS gene. Although multiple transcription start points (tsp) are utilized, transcription of hTS is primarily TATA-independent, as determined by promoter-directed reporter gene expression in transfected cells. A dinucleotide (CA) repetitive sequence identified in the ninth intron of the gene exhibits allelic polymorphism. At least four distinctive alleles, containing from 13 to 20 copies of the CA repeats, have been detected.

Cloning and characterization of the human thromboxane synthase gene promoter

A genomic phage clone hybridized to the 5' end of human thromboxane synthase (TS) cDNA was isolated. Sequencing analysis of a 1.7 kb subfragment revealed that it contained the entire 5' untranslated region and 46 bp of the coding sequence of TS cDNA, an upstream canonical TATA box (TATAAA), and several binding sites for transcription factors (AP1, PEA3, PU.1, and GR), indicative of a promoter/first exon region of the TS gene. RNase protection assay mapped the transcription start site of the human TS gene to the nucleotide A 30 bp downstream from the TATA box. The authenticity of the promoter was further confirmed by its ability to direct expression of a CAT reporter gene in transfected HL60 cells.

The porcine thromboxane synthase-encoding cDNA: sequence, mRNA expression and enzyme production in Sf9 insect cells

A full-length cDNA encoding porcine thromboxane synthase (TS) was isolated and sequenced. The open reading frame encodes a 534-amino acid (aa) protein (M(r) 60,451) which shares more than 75% identity with TS from other species and is 30% homologous to several enzymes of the cytochrome P-450 III family. Sequence comparison among porcine (p), human (h), and murine (m) TS indicated conservation of eight Cys residues and one putative N-glycosylation site. Several highly conserved regions were identified at the near N terminus, middle and C terminus. The most divergent region lies at aa residues 290-325, within which a Lys308 residue was unique to pTS. Between aa residues 70 and 90, considerable divergence was observed in mTS. Northern analysis showed that the pTS gene was expressed as a 2.3-kb transcript primarily in lung, kidney and thymus. A high-titer recombinant (re-) baculovirus containing pTS cDNA was developed to conduct a time course study of enzyme production in Spodoptera frugiperda (Sf9) cells. TS activity was detectable in the microsomes of Sf9 cells 12-h post-infection and reached maximum by 48 h. The produced TS resembles purified pTS in catalysis, as well as inhibition by a substrate analog inhibitor.

Expression of two different forms of cDNA for thromboxane synthase in insect cells and site-directed mutagenesis of a critical cysteine residue

cDNA coding for human placental thromboxane synthase (EC 5.3.99.5) was amplified by PCR from a human placental cDNA library and sequenced. This cDNA and a shorter cDNA isolated from a human lung cDNA library with a deletion of 163 bp near the 3' end were expressed in Spodoptera frugiperda (Sf9) insect cells using a baculovirus expression system. The cDNA from human placenta was expressed as an active enzyme (60 kDa) with a specific activity higher than those reported from other cell types, whereas the shorter cDNA was expressed in an inactive form (52 kDa). The active recombinant enzyme appeared to be unglycosylated as the molecular mass and the enzyme activity were not altered in the presence of tunicamycin. Site-directed mutagenesis was performed to convert a cysteine at position 480 in thromboxane synthase to a serine. This cysteine is found to be highly conserved in related cytochrome P-450 enzymes. The mutant enzyme was found to be inactive, although Western blot, immunoprecipitation and SDS/PAGE analysis indicated that the mutant enzyme was expressed at a level comparable with the wild-type enzyme. These results suggest that Cys-480 is essential for the enzyme catalytic activity and that the short-form cDNA may be a non-functional transcript.

Mapping of the human thromboxane synthase gene (TBXAS1) to chromosome 7q34-q35 by two-color fluorescence in situ hybridization

Thromboxane synthase (TS) catalyzes the conversion of the prostaglandin endoperoxide into thromboxane A2 (TxA2), a potent vasoconstrictor and inducer of platelet aggregation. In concert with prostacyclin TxA2 plays a pivotal role in the maintenance of hemostasis. Deficiency of platelet TS activity has been shown to result in bleeding disorders. The potent effect of TxA2 on platelet function and vascular activity suggests a possible involvement of TS in normal and pathophysiological conditions such as cardiovascular disease. To aid in establishing the correlation of TS to disease states, we localized the human TS gene (TBXAS1) to chromosome 7q34-q35 using dual-color fluorescence in situ hybridization.

Cloning and nucleotide sequence of the Lactobacillus casei lactate dehydrogenase gene

An allosteric L-(+)-lactate dehydrogenase gene of Lactobacillus casei ATCC 393 was cloned in Escherichia coli, and the nucleotide sequence of the gene was determined. The gene was composed of an open reading frame of 981 bp, starting with a GTG codon and ending with a TAA codon. The sequences for the promoter and ribosome binding site were identified, and a sequence for a structure resembling a rho-independent transcription terminator was also found.