Delaying surgery to perform CT scans for suspected appendicitis decreases the rate of negative appendectomies without increasing the rate of perforation nor postoperative complications

PURPOSE

Negative appendectomies are costly and are embedded with unnecessary risks for the patients. A careful indication for surgery seems mandatory even more so, since conservative therapy emerges as a potential alternative to surgery. The aims of this population-based study were to analyze whether radiological examinations for suspected appendicitis decreased the rate of negative appendectomies without increasing the rate of perforation or worsening postoperative outcomes.

METHOD

This study is a retrospective analysis of a prospective population-based database. The data collection included preoperative investigations and intraoperative and postoperative outcomes.

RESULTS

Based on 2559 patients, the rate of negative appendectomies decreased significantly with the use of CT scan as compared to clinical evaluation only (9.3 vs 5 %, p = 0.019), whereas ultrasonography alone was not able to decrease this rate (9.3 vs 6.2 %, p = 0.074). Delaying surgery for radiological investigation did not increase the rate of perforation (18.1 vs 19.2 %; adjusted odds ratio (OR) 1.01; 0.8-1.3; p = 0.899). Postoperative complications (surgical reintervention, postoperative wound infection, postoperative hematoma, postoperative intra-abdominal abscess, postoperative ileus) were all comparable.

CONCLUSION

In this population-based study, CT scan was the only radiological modality that significantly reduced the rate of negative appendectomy. The delay induced by such additional imaging did not increase perforation nor complication rates. Abdominal CT scans for suspected appendicitis should therefore be more frequently used if clinical findings are unconclusive.

Air suctioning during colon biopsy forceps removal reduces bacterial air contamination in the endoscopy suite

BACKGROUND AND STUDY AIMS

Bacterial contamination of endoscopy suites is of concern; however studies evaluating bacterial aerosols are lacking. We aimed to determine the effectiveness of air suctioning during removal of biopsy forceps in reducing bacterial air contamination.

PATIENTS AND METHODS

This was a prospective single-blinded trial involving 50 patients who were undergoing elective nontherapeutic colonoscopy. During colonoscopy, endoscopists removed the biopsy forceps first without and then with suctioning following contact with the sigmoid mucosa. A total of 50 L of air was collected continuously for 30 seconds at 30-cm distance from the biopsy channel valve of the colonoscope, with time starting at forceps removal. Airborne bacteria were collected by an impactor air sampler (MAS-100). Standard Petri dishes with CNA blood agar were used to culture Gram-positive bacteria. Main outcome measure was the bacterial load in endoscopy room air.

RESULTS

At the beginning and end of the daily colonoscopy program, the median (and interquartile [IQR] range) bioaerosol burden was 4 colony forming units (CFU)/m (3) (IQR 3 - 6) and 16 CFU/m (3) (IQR 13 - 18), respectively. Air suctioning during removal of the biopsy forceps reduced the bioaerosol burden from a median of 14 CFU/m (3) (IQR 11 - 29) to a median of 7 CFU/m (3) (IQR 4 - 16) ( P = 0.0001). Predominantly enterococci were identified on the agar plates.

CONCLUSION

The bacterial aerosol burden during handling of biopsy forceps can be reduced by applying air suction while removing the forceps. This simple method may reduce transmission of infectious agents during gastrointestinal endoscopies.

Randomized clinical trial comparing venous cutdown with the Seldinger technique for placement of implantable venous access ports

Background

The aim of this randomized controlled study was to compare the primary success rate between venous cutdown and the Seldinger technique for placement of the totally implantable venous access port (TIVAP).

Methods

A total of 152 patients were randomized to receive TIVAP placement by either venous cutdown or the Seldinger technique. The main endpoint was the primary success rate. Secondary endpoints included overall success rate, procedure time and perioperative complication rates. Multiple logistic regression analysis was undertaken to assess the influence of different variables on primary success.

Results

The primary success rate was 71 per cent for venous cutdown and 90 per cent for the Seldinger technique (P = 0·007). The mean procedure time was significantly shorter for the Seldinger technique (48·9 versus 64·8 min; P < 0·001). The overall success rate was 97·4 per cent. The rate of perioperative complications was similar for the two approaches (5 per cent), but was higher when a procedure was converted. The variables sex, body mass index, implantation side and surgeon experience had no impact on the primary success rate.

Conclusion

The Seldinger technique was more effective and quicker than venous cutdown, and should be regarded as the method of choice for TIVAP placement. Registration number: NCT00272623 (http://www.clinicaltrials.gov).

Long-term follow-up of proximal versus distal laparoscopic gastric bypass for morbid obesity

BACKGROUND

Laparoscopic gastric bypass is the 'gold standard' for treatment of morbidly obese patients in many centres. There is debate regarding the optimal length for small bowel limbs. This study aimed to determine whether the proximal or distal approach is better.

METHODS

Twenty-five patients undergoing primary distal gastric bypass in 2000-2002 were randomly matched for age, sex and preoperative body mass index (BMI) with 25 patients having a primary proximal bypass. All distal operations were performed laparoscopically; one proximal procedure was converted to open surgery.

RESULTS

Mean operating time was 170 min for proximal and 242 min for distal bypasses (P = 0.004); median hospital stay was similar in the two groups. There were no deaths and the overall complication rate was similar, as was weight loss at 4 years: BMI decreased from 45.9 to 31.7 kg/m2 for the proximal and from 45.8 to 33.1 kg/m2 for the distal approach. Co-morbidities decreased after surgery in both groups; the prevalence of diabetes, arterial hypertension and dyslipidaemia at all time points was similar in the two groups.

CONCLUSION

Proximal and distal laparoscopic gastric bypass operations are feasible and safe, with no differences in weight loss or reduction of co-morbidity in unselected morbidly obese patients.

High secondary failure rate of rebanding after failed gastric banding

BACKGROUND

Over the last decade, more than 130,000 laparoscopic adjustable gastric bandings (LAGB) have been performed for the treatment of morbid obesity. Nowadays, longer follow-up data are available in the literature and increasing numbers of late complications and treatment failures of gastric banding have been reported. The aim of the present study was the long-term evaluation of two different rescue operations after failed LAGB: conversion to laparoscopic Roux-en-Y bypass (LRYGB) versus laparoscopic gastric rebanding.

METHODS

Between January 1997 and November 2002, 74 consecutive patients underwent either laparoscopic gastric rebanding (n = 44) or LRYGB (n = 30) after failed LAGB. There were 14 men and 60 women, with a median age of 42 (23-60) years. The indication for reoperation was an increasing body mass index (BMI) and band-related complications such as pouch dilatation, band slippage, and penetration after LAGB. Rebandings were done by preference during the initial period of the study and LRYGB was the treatment of choice during the latter period. The success of the rescue operation was assessed by postoperative changes in the BMI, improvements of co-morbidities, and the need for further reoperations (secondary failure). The median follow-up was 36 months (range, 24-60 months).

RESULTS

Patients who underwent LRYGB had a significantly better weight loss than patients with a rebanding operation (mean -6.1 versus +1.5 BMI points). In addition, the LRYGB patients showed a significantly better control of serum cholesterol during the long term follow-up (-0.6 versus +0.1 mmol/l). Almost half of the patients (45%) in the rebanding group needed a further operative revision, whereas only 20% underwent reoperation after rescue LRYGB. Thus, the secondary failure rate in the rebanding group was significantly higher compared to the bypass group (p = 0.028).

CONCLUSIONS

The present long-term study confirms our previous finding that LRYGB is a better treatment than rebanding after failed laparoscopic gastric banding regarding weight loss and treatment of co-morbidities. During the long-term follow-up the reoperation rate due to secondary failure became significantly higher in the rebanding group. We therefore recommend that LRYGB should be preferred as rescue procedure after failed laparoscopic adjustable gastric banding.

[Evidential basis in bariatric surgery]

Bariatric surgery is currently considered the best treatment option for morbid obesity. With the rapid development of laparoscopic techniques, a significant increase in the number bariatric procedures in recent years can be observed. Various surgical techniques to treat morbid obesity have been described, but only few prospective studies compare the different procedures, leading to a lack of evidence for their use. However, from the available literature some general recommendations can be given: (a) preoperative workup in an interdisciplinary team is mandatory, (b) primary bariatric procedures should be performed laparoscopically, and (c) the combination of restrictive and malabsorptive techniques is more efficient than a purely restrictive method, which is also true for the treatment of comorbid diabetes and arterial hypertension. In this paper, we present recent developments in bariatric surgery, with special emphasis on the available evidence for the best treatment of morbidly obese patients.

Critical evaluation of the different staging systems for hepatocellular carcinoma

BACKGROUND

Diagnostic and therapeutic options for hepatocellular carcinoma (HCC) have improved substantially in recent years. A number of new palliative and potentially curative treatment strategies are now available. However, evaluation of the therapeutic modalities and assessment of the prognosis of HCC remain difficult owing to the lack of consensus on a single staging system and the availability of a number of new staging systems, each claiming to be the most appropriate.

METHODS

The most frequently used staging systems for HCC are presented here. Their ability to stratify patients into different treatment groups and to define prognosis are discussed. In addition, the advantages and disadvantages of each system are analysed.

RESULTS AND CONCLUSION

None of the currently used staging systems fulfils all the requirements for stratification of patients with HCC into groups of different prognosis and therapeutic recommendations. An international agreement on a single staging system is urgently needed in order to permit comparable randomized clinical trials. Only in this way will the outcome for those with HCC be improved.

Comparison of EUS-guided 19-gauge Trucut needle biopsy with EUS-guided fine-needle aspiration

BACKGROUND AND STUDY AIMS

The accuracy of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) depends on immediate specimen review by a cytopathologist. Stromal tumors, lymphoma, and well-differentiated pancreatic cancer are difficult to diagnose on the basis of cytology alone. To overcome these limitations, a 19-gauge Trucut needle has been developed to obtain histological samples at EUS. This pilot study compares the specimen adequacy and diagnostic accuracy of EUS-guided Trucut needle biopsy (EUS-TNB) with EUS-FNA.

PATIENTS AND METHODS

A total of 18 patients underwent EUS-TNB and EUS-FNA. The specimen adequacy and diagnostic accuracy of the two techniques was compared. The technical performance and safety profile of the Trucut needle were also evaluated.

RESULTS

The EUS-TNB specimen was adequate for evaluation in 15/18 patients compared with 18/18 with EUS-FNA (83 % vs. 100 %, not significant). The diagnostic accuracy of EUS-TNB was not significantly different from EUS-FNA (78 % vs. 89 %). Two complications were encountered: one patient developed mediastinitis and required surgery; another had immediate bleeding that was managed conservatively. One technical problem was encountered: the Trucut needle failed to deploy after two passes when a gastric stromal cell tumor was being biopsied.

CONCLUSION

The diagnostic accuracy of the new EUS-TNB is comparable to that of EUS-FNA. In our experience, the overall efficacy and safety profile of the Trucut needle appears modest.

[New modalities and concepts in the treatment of hemorrhoids]

The surgical treatment of haemorrhoids has significantly changed by introducing new techniques in the last years. Nowadays, low grade haemorrhoids, grade II and III, are easily and painfree treatable by a minimal invasive, Doppler transducer guided ligation of the haemorrhoidal arteries. In cases of circular protruding haemorrhoids, grade III and IV; the stapled mucosectomy described by Longo is also a new effective treatment. Both procedures can be performed for an outpatient or with short hospital stay and allows patients to return to work earlier compared to conventional techniques. Additionally, due to the new techniques the treatment of haemorrhoids is less painful and has increased patients' satisfaction. Therefore, the traditional haemorrhoidectomy, the Milligan-Morgan or the Ferguson procedure, has become less common and is only performed in a few special indications.

Influence of naloxone on gastric emptying of solid meals, myoelectrical gastric activity and blood hormone levels in young healthy volunteers

There is considerable evidence that opioid mechanisms are involved in the mediation of pyloric motor responses that in turn regulate gastric emptying. The purpose of this randomized, placebo-controlled crossover study was to investigate the effect of naloxone on gastric emptying of a solid meal, gastric myoelectrical activity and the postprandial release of gastrointestinal peptides and neuropeptides in 20 healthy volunteers. Naloxone was administered as an intravenous bolus, followed by continuous infusion according to an intravenous dosing nomogram. Gastric emptying time was evaluated by scintigraphy and gastric myoelectrical activity was evaluated by cutaneous electrogastrography. Naloxone did not significantly alter gastric half-emptying time and postprandial dominant gastric electrical frequency compared with placebo. It also did not significantly change the plasma levels of several peptide hormones with the exception of neuropeptide Y, which was significantly increased (P = 0.001). In conclusion, in doses that influence human intestinal motility, naloxone had no effect on gastric motility and release of several peptide hormones in healthy male volunteers. The importance of the isolated increased neuropeptide Y plasma level needs further investigation.

Neoadjuvant and adjuvant therapies for resectable hepatocellular carcinoma (HCC) and palliation strategies

Hepatocellular carcinoma (HCC) is the most common primary malignancy in the liver worldwide. The incidence of the tumor varies geographically. Thus, in the eastern area (China, Taiwan, and Japan) there are more than 20 cases per year per 100'000 population compared to less than 5 cases per 100'000 in most western countries [1]. The etiology of HCC is multifactorial. The two most important factors are the presence of cirrhosis and chronic hepatitis [2]. Early detection of HCC still remains a challenge. At the time of diagnosis, only 20-30% of all patients have tumors that are surgically resectable. Survival after curative resection is 30%-50% at five years. The poor outcome of the disease led to the development of different adjuvant and neoadjuvant therapies. There are numerous studies dealing with the treatment of HCC. Unfortunately, only few randomized controlled trials exist. In addition, there is no consensus on staging of HCC and no standardization of the outcome in the literature, which makes it difficult to compare the different procedures. This paper summarizes the current strategies in the treatment of HCC.

Does intravenous ondansetron affect gastric emptying of a solid meal, gastric electrical activity or blood hormone levels in healthy volunteers?

BACKGROUND

In previous studies, tropisetron has been shown to accelerate gastric emptying of a solid meal. However, it is uncertain whether other specific 5-hydroxytryptamine-3 receptor antagonists, such as ondansetron, also have a gastroprokinetic effect in humans.

AIM

To evaluate the effect of ondansetron on gastric half-emptying time (T1/2) of a solid meal, gastric myoelectrical activity and hormone levels in 14 healthy volunteers.

METHODS

In a placebo-controlled, randomized, crossover study, we investigated the effects of ondansetron (8 mg intravenously) on the gastric emptying of solids (by scintigraphy), gastric myoelectrical activity (by electrogastrography) and the post-prandial release of cholecystokinin, gastrin, human pancreatic polypeptide, gastric inhibitory polypeptide, vasoactive intestinal polypeptide, motilin, substance P and galanin.

RESULTS

The average T1/2 values were 86 min and 85.5 min without lag time (P=0.082) and 92 min and 93 min with lag time (P=0.158) for the placebo and ondansetron treatments, respectively. The average T1/2 of female volunteers was significantly longer than that of male volunteers. The dominant gastric electrical frequency and hormone plasma concentrations were not altered by ondansetron.

CONCLUSIONS

Ondansetron did not affect the gastric emptying of solids, the dominant gastric electrical frequency or the plasma concentrations of the analysed gastrointestinal peptides.

Overexpression of activin A in stage IV colorectal cancer

BACKGROUND AND AIMS

Activins and inhibins are dimeric polypeptides that belong to the transforming growth factor beta (TGF-beta) superfamily and that bind to transmembrane receptors with serine/threonine kinase activity. The aim of this study was to characterise, in colon cancer cell lines and in normal and malignant human colon tissues, levels of expression of inhibin subunits that are involved in activin/inhibin dimer formation, and of the type I and II activin receptors (actRI and actRII).

METHODS

Expression of inhibin subunits and activin receptors was analysed by northern blot analysis. Inhibin betaA and activin receptor expression were also assessed by use of polymerase chain reaction (PCR). In addition, activin A/inhibin betaA localisation in human colon samples was assessed by immunohistochemistry and in situ hybridisation.

RESULTS

Inhibin betaA mRNA was expressed in CaCo2 cells but not in SW 837 or SW 1463 cells whereas inhibin betaB and inhibin alpha were below the level of detection. In contrast, all four activin receptors were present in the three cell lines. Colon cancers overexpressed inhibin betaA mRNA in comparison with normal colon, and this overexpression was greatest in stage IV tumours. ActRIb mRNA levels were slightly higher in the normal colon than in cancer tissues. By immunohistochemistry and in situ hybridisation, activin A and inhibin betaA mRNA were present in the mucosal epithelial cells in normal tissues from patients with stage I disease but were either absent or weakly present in normal tissues from patients with stage IV disease. Conversely, they were present at weak to moderate levels in stage I cancers but at high levels in stage IV cancers.

CONCLUSIONS

Our findings indicate that activin A is overexpressed in human colorectal tumours, especially in stage IV disease, raising the possibility that activin A may have a role in advanced colorectal cancer.

Efficacy and safety of weight-adapted nadroparin calcium vs. heparin sodium in prevention of clinically evident thromboembolic complications in 1,190 general surgical patients

AIMS

In a prospective, randomized, single, general surgery center trial, comparison of the safety and efficacy of two low molecular weight heparin (LMWH; anti-Xa heparin sodium and weight-adapted nadroparin calcium) regimens was made.

PATIENTS AND METHODS

Eleven hundred and ninety patients undergoing various elective and emergency operations were randomized to receive daily either a fixed dose of 3,000 IU anti-Xa heparin sodium or a variable body weight-dependent dose of nadroparin calcium (weight <50 kg, 2,050 IU anti-Xa (WHO); 51-80 kg, 3,075 UI; 81-100 kg, 4,100 UI, and >100 kg, 6,150 UI) once until discharge. The first injection was administered 2.5-6 h before elective and emergency operations, respectively. Patients with clinical suspicion of deep venous thrombosis (DVT) underwent phlebography. Patients with signs of pulmonary embolism (PE) were further investigated by a ventilation-perfusion scan.

RESULTS

Statistically, there were no significant differences in the incidence of clinically evident DVT, PE or LMWH-related complications between both prophylactic regimens. Only 4 of the total of 15 hemorrhagic complications (4 wound hematomas in the nadroparin calcium group) were not classified as clearly surgically related, Two DVTs were confirmed by phlebography (both in the nadroparin calcium group). PE was confirmed by ventilation-perfusion scans (1 fatal, 1 on autopsy) in 1 patient with heparin sodium and in 6 patients with nadroparin calcium.

CONCLUSIONS

Both regimens were equally safe and the risk of clinically evident DVT and PE was similar.

[The role of intravenous cholangiography in the era of laparoscopic cholecystectomy: is there a renaissance?]

BACKGROUND AND OBJECTIVE

The preoperative investigation for choledocholithiasis in patients undergoing elective laparoscopic cholecystectomy is still a matter of debate.

PATIENTS AND METHODS

In a prospective clinical trial the accuracy of intravenous cholangiography (IVC), ultrasonography and liver function tests in the preoperative diagnosis of choledocholithiasis was assessed in 98 patients undergoing elective cholecystectomy. Only patients with uncomplicated cholecystolithiasis considered to be at low risk for having bile duct stones were investigated. A 2-year follow-up clinical survey (mean) was performed in 92 of the 98 patients to investigate the occurrence of postoperative choledocholithiasis (gold standard: clinically manifest choledocholithiasis).

RESULTS

In this patient cohort the incidence of choledocholithiasis was found to be 5.1%. Among the three diagnostic tests IVC proved to be more accurate with higher sensitivity and a better positive predictive value than ultrasonography and liver function tests. The sensitivity for IVC was 100% compared to 20% for ultrasonography and 40% for liver function tests, respectively. The positive predictive value for IVC was 83.3% in comparison to 20% for ultrasonography and 25% for liver function tests. Mild side effects caused by intravenous contrast media were observed in 2.0%. During a mean postoperative follow-up of 2 years no clinically manifest and initially overlooked choledocholithiasis could be detected in the 92 investigated patients.

CONCLUSION

IVC is a reliable method to detect unsuspected common bile duct stones and should be used in the preoperative diagnosis prior to elective laparoscopic cholecystectomy. IVC may play a role in decreasing the rate of preoperative ERCP or intraoperative cholangiography in these patients.

Characterization of cytokeratin 20 expression in pancreatic and colorectal cancer

Cytokeratin 20 belongs to the epithelial subgroup of the intermediate filament family. Because of its restricted range of expression in humans, it has become an important tool for detecting and identifying metastatic cancer cells by immunohistochemistry and by PCR analysis. Despite its widespread diagnostic use in colorectal cancer and occasional use in pancreatic cancer, little is known about the expression of CK 20 in these tumors in vivo. Therefore, in the present study we characterized CK 20 expression in pancreatic and colorectal cancer by comparison with its expression in the normal pancreas and colon. Tissue samples from 24 patients with pancreatic cancer and from 41 patients with colorectal cancer were examined for CK 20 expression by Northern blot analysis, immunohistochemistry, and in situ hybridization. CK 20 expression was observed in the cancer cells of both cancer types. A subgroup of the pancreatic cancers exhibited a 3.2-fold increase in CK 20 mRNA by comparison with respective normal controls. In contrast, colon cancers underexpressed CK 20 mRNA by comparison with the respective controls. In the normal tissues, CK 20 immunoreactivity was relatively faint and sparse in the pancreatic ductal cells but intense and abundant in the apical portions of the colonic mucosa. CK 20 immunoreactivity was also evident in the ductal cells from the chronic pancreatitis-like lesions adjacent to the cancer cells. Furthermore, distant metastases from pancreas carcinomas exhibited strong CK 20 immunoreactivity. It is concluded that CK 20 is overexpressed in pancreatic cancer and that it can serve as an excellent marker for metastatic pancreatic cancer.

Stable transfection of a glypican-1 antisense construct decreases tumorigenicity in PANC-1 pancreatic carcinoma cells

Glypican-1 belongs to a family of glycosylphosphatidylinositol (GPI)-anchored heparan sulfate proteoglycans (HSPGs) that affect cell growth, invasion, and adhesion. Cell-surface HSPGs are believed to act as co-receptors for heparin-binding mitogenic growth factors. It was reported that glypican-1 is strongly expressed in human pancreatic cancer, and that it may play an essential role in regulating growth-factor responsiveness in pancreatic carcinoma cells. In this study we investigated the effects of decreased glypican-1 expression in PANC-1 pancreatic cancer cells. To this end, PANC-1 cells were stable transfected with a full-length glypican-1 antisense construct. The glypican- antisense transfected clones displayed markedly reduced glypican- protein levels and a marked attenuation of the mitogenic responses to heparin-binding growth factors that are commonly overexpressed in pancreatic cancer: fibroblast growth factor-2 (FGF2), heparin-binding epidermal growth factor (EGF)-like growth factor (HB-EGF), and hepatocyte growth factor (HGF). In addition, glypican-1 antisense-expressing PANC-1 cells exhibited a significantly reduced ability to form tumors in nude mice in comparison with parental and sham-transfected PANC-1 cells. These data suggest that glypican-1 plays an important role in the responses of pancreatic cancer cells to heparin-binding growth factors, and documents for the first time that its expression may enhance tumorigenic potential in vivo.

Id-1 and Id-2 are overexpressed in pancreatic cancer and in dysplastic lesions in chronic pancreatitis

Id proteins antagonize basic helix-loop-helix proteins, inhibit differentiation, and enhance cell proliferation. In this study we compared the expression of Id-1, Id-2, and Id-3 in the normal pancreas, in pancreatic cancer, and in chronic pancreatitis (CP). Northern blot analysis demonstrated that all three Id mRNA species were expressed at high levels in pancreatic cancer samples by comparison with normal or CP samples. Pancreatic cancer cell lines frequently coexpressed all three Ids, exhibiting a good correlation between Id mRNA and protein levels, as determined by immunoblotting with highly specific anti-Id antibodies. Immunohistochemistry using these antibodies demonstrated the presence of faint Id-1 and Id-2 immunostaining in pancreatic ductal cells in the normal pancreas, whereas Id-3 immunoreactivity ranged from weak to strong. In the cancer tissues, many of the cancer cells exhibited abundant Id-1, Id-2, and Id-3 immunoreactivity. Scoring on the basis of percentage of positive cells and intensity of immunostaining indicated that Id-1 and Id-2 were increased significantly in the cancer cells by comparison with the respective controls. Mild to moderate Id immunoreactivity was also seen in the ductal cells in the CP-like areas adjacent to these cells and in the ductal cells of small and interlobular ducts in CP. In contrast, in dysplastic and atypical papillary ducts in CP, Id-1 and Id-2 immunoreactivity was as significantly elevated as in the cancer cells. These findings suggest that increased Id expression may be associated with enhanced proliferative potential of pancreatic cancer cells and of proliferating or dysplastic ductal cells in CP.

Ligand induced upregulation of the type II transforming growth factor (TGF-beta) receptor enhances TGF-beta responsiveness in COLO-357 cells

The effects of transforming growth factor (TGF)-beta 1 on type I and type II TGF-beta receptor (T beta RI and T beta RII) expression were examined in five pancreatic cancer cell lines. In contrast to its actions in COLO-357, a TGF-beta-sensitive pancreatic cancer cell line, TGF-beta 1 did not significantly alter TGF-beta receptor expression in either the TGF-beta-sensitive BXPC-3 and PANC-1 cells or in the TGF-beta-resistant CAPAN-1 and T3M4 cells. Neutralizing anti-T beta RII antibodies blocked TGF-beta 1-dependent signaling in COLO-357 cells but exhibited an attenuated effect in COLO-357 cells preincubated with TGF-beta 1 for 48 h. Basal T beta RII expression levels were comparable in all five cell lines examined. In contrast, COLO-357 cells and BX-PC-3 cells expressed relatively high basal levels of T beta RI. However, COLO-357 cells harbored a normal Smad4 gene, whereas BX-PC-3 cells exhibited a complete deletion of this gene. We conclude that the TGF-beta 1-induced T beta RII upregulation serves to enhance TGF-beta 1 responsiveness in COLO-357 cells, and that this upregulation requires the presence of adequate levels of T beta RI and T beta RII, and a functional Smad4 gene product. Our findings also indicate that TGF-beta 1 may inhibit pancreatic cancer cell growth via a Smad4-independent pathway.

A novel colon pouch and its comparison with a straight coloanal and colon J-pouch--anal anastomosis: preliminary results in pigs

BACKGROUND

Early functional results after complete rectal resection and straight coloanal anastomosis are often characterized by frequent bowel movements, urgency, and varying degrees of stool incontinence. The formation of a colon reservoir improves early and long-term function. We evaluated the feasibility of a novel, modified design of a colon pouch--anal anastomosis in pigs and compared the results with those of pigs with straight coloanal anastomosis and colon J-pouch.

METHODS

Complete rectal resection followed by either a straight coloanal anastomosis, a colon J-pouch, or a novel design of a colon pouch was performed in equal numbers in 15 pigs. By transversely closing a longitudinal colotomy, the new, technically simpler pouch is formed. Functional results were assessed during a period of 6 weeks.

RESULTS

All 15 procedures were successful. The novel colon pouch required less surgical time than the colon J-pouch, and the formation of the pouches did not reduce tissue perfusion as assessed by laser Doppler flowmetry. The mean volume of the novel colon pouch was significantly smaller than the volume of the colon J-pouch. All the pigs with the novel colon pouch had normal stool frequency and consistency during a period of 6 weeks. In the group with straight coloanal anastomosis, two pigs had increased frequency of defecation, one pig showed signs of urgency and perianal dermatitis, and three had substantially reduced stool consistency. Of the four pigs with colon J-pouch, three had signs of impaired pouch evacuation and two had reduced stool frequency.

CONCLUSIONS

The novel colon pouch is feasible in pigs and technically simpler than the colon J-pouch. These preliminary results indicate that the smaller capacity of this pouch seems sufficient for normal defecation. Its short-term functional results were better than those after reconstruction with a colon J-pouch or a straight coloanal anastomosis.

A novel colon pouch and its comparison with a straight coloanal and colon J-pouch--anal anastomosis: preliminary results in pigs

BACKGROUND

Early functional results after complete rectal resection and straight coloanal anastomosis are often characterized by frequent bowel movements, urgency, and varying degrees of stool incontinence. The formation of a colon reservoir improves early and long-term function. We evaluated the feasibility of a novel, modified design of a colon pouch--anal anastomosis in pigs and compared the results with those of pigs with straight coloanal anastomosis and colon J-pouch.

METHODS

Complete rectal resection followed by either a straight coloanal anastomosis, a colon J-pouch, or a novel design of a colon pouch was performed in equal numbers in 15 pigs. By transversely closing a longitudinal colotomy, the new, technically simpler pouch is formed. Functional results were assessed during a period of 6 weeks.

RESULTS

All 15 procedures were successful. The novel colon pouch required less surgical time than the colon J-pouch, and the formation of the pouches did not reduce tissue perfusion as assessed by laser Doppler flowmetry. The mean volume of the novel colon pouch was significantly smaller than the volume of the colon J-pouch. All the pigs with the novel colon pouch had normal stool frequency and consistency during a period of 6 weeks. In the group with straight coloanal anastomosis, two pigs had increased frequency of defecation, one pig showed signs of urgency and perianal dermatitis, and three had substantially reduced stool consistency. Of the four pigs with colon J-pouch, three had signs of impaired pouch evacuation and two had reduced stool frequency.

CONCLUSIONS

The novel colon pouch is feasible in pigs and technically simpler than the colon J-pouch. These preliminary results indicate that the smaller capacity of this pouch seems sufficient for normal defecation. Its short-term functional results were better than those after reconstruction with a colon J-pouch or a straight coloanal anastomosis.

Over-expression of ICAM-1, VCAM-1 and ELAM-1 might influence tumor progression in colorectal cancer

Adhesion molecules might play a role in tumor progression. We investigated expression of the adhesion molecules ICAM-1, VCAM-1 and ELAM-1 in 24 primary colorectal carcinomas using immuno-histochemistry and Northern blot analysis. Normal colonic tissue from the same patients served as controls. ICAM-1 immunostaining was restricted to the intercellular matrix and vascular endothelial cells. The vast majority of normal tissue samples revealed only faint ICAM-1 immunoreactivity. However, moderate to strong immunostaining was found in 86% of cancerous sections. The ICAM-1 immunoreaction was more intense in well-differentiated carcinomas as well as in the adenomatous parts and transition zones of cancers. Similarly, the cancers exhibited markedly enhanced VCAM-1 and ELAM-1 immunostaining in the endothelial cells of small blood vessels. The intense vascular immunostaining by ICAM-1 and VCAM-1 was associated with a strong presence of CD3-positive T lymphocytes, whereas ELAM-1 immunoreactivity did not correlate with round cell infiltration. On Northern blot analysis, ICAM-1, VCAM-1 and ELAM-1 mRNA levels were increased in 67%, 57% and 63% of carcinomas, respectively, in comparison with normal tissue samples. Densitometric analysis of Northern blots revealed an increase in ICAM-1 by 2.1-fold, an increase in VCAM-1 by 3.4-fold and an increase in ELAM-1 by 2.2-fold in cancerous tissues compared to normal controls. Over-expression of ICAM-I might prevent cell-cell disruption and, hence, tumor dissemination. Furthermore, over-expression of ICAM-1 and VCAM-1, but not ELAM-1, might favor host anti-tumor defense by trafficking of lymphocytes.

Superselective microcoil embolization: treatment of choice in high-risk patients with extrahepatic pseudoaneurysms of the hepatic arteries

BACKGROUND

Only a few isolated case reports of extrahepatic pseudoaneurysms of the hepatic arteries have been published. We present the first documented series of patients with extrahepatic pseudoaneurysms treated at a single institution, and discuss the etiology and management of this condition.

STUDY DESIGN

A retrospective review of all cases of extrahepatic pseudoaneurysms of the hepatic arteries between 1989 and 1997.

RESULTS

A total of seven patients with extrahepatic pseudoaneurysms of the hepatic arteries all had upper abdominal pain; five patients were also in shock secondary to a gastrointestinal bleeding from ruptured pseudoaneurysms. The most common factor of the pseudoaneurysms was previous pancreatobiliary surgery in five patients with blunt truncal trauma and chronic pancreatitis in the remaining two patients. Initial endoscopy and ultrasonography were unrevealing, whereas dynamic computed tomography (CT) scan and angiography were diagnostic. The median size of the pseudoaneurysms was 3.6 cm (range 2.1-5.7). Treatment consisted of superselective transcatheter microcoil embolization in five hemodynamically unstable patients and surgical resection of the pseudoaneurysms with vascular reconstruction in the two stable patients. Mortality and morbidity were 0% and 43%, respectively. In a median followup of 35 months (range 2-96), no recurrence of pseudoaneurysm has been found.

CONCLUSIONS

A high index of suspicion combined with appropriate diagnostic modalities are required for the diagnosis of extrahepatic pseudoaneurysms. In high-risk patients, superselective transcatheter microcoil embolization should be considered the treatment of choice.

Over-expression of ICAM-1, VCAM-1 and ELAM-1 might influence tumor progression in colorectal cancer

Adhesion molecules might play a role in tumor progression. We investigated expression of the adhesion molecules ICAM-1, VCAM-1 and ELAM-1 in 24 primary colorectal carcinomas using immuno-histochemistry and Northern blot analysis. Normal colonic tissue from the same patients served as controls. ICAM-1 immunostaining was restricted to the intercellular matrix and vascular endothelial cells. The vast majority of normal tissue samples revealed only faint ICAM-1 immunoreactivity. However, moderate to strong immunostaining was found in 86% of cancerous sections. The ICAM-1 immunoreaction was more intense in well-differentiated carcinomas as well as in the adenomatous parts and transition zones of cancers. Similarly, the cancers exhibited markedly enhanced VCAM-1 and ELAM-1 immunostaining in the endothelial cells of small blood vessels. The intense vascular immunostaining by ICAM-1 and VCAM-1 was associated with a strong presence of CD3-positive T lymphocytes, whereas ELAM-1 immunoreactivity did not correlate with round cell infiltration. On Northern blot analysis, ICAM-1, VCAM-1 and ELAM-1 mRNA levels were increased in 67%, 57% and 63% of carcinomas, respectively, in comparison with normal tissue samples. Densitometric analysis of Northern blots revealed an increase in ICAM-1 by 2.1-fold, an increase in VCAM-1 by 3.4-fold and an increase in ELAM-1 by 2.2-fold in cancerous tissues compared to normal controls. Over-expression of ICAM-I might prevent cell-cell disruption and, hence, tumor dissemination. Furthermore, over-expression of ICAM-1 and VCAM-1, but not ELAM-1, might favor host anti-tumor defense by trafficking of lymphocytes.

[Tumor staging and follow-up care in rectosigmoid carcinoma: colonoscopic endosonography compared to CT, MRI and endorectal MRI]

BACKGROUND AND STUDY AIMS

Endosonography has become the best available method for local staging of primary rectal cancer and diagnosing recurrent local tumor. The aim of this prospective study is to compare the accuracy of endoscopic ultrasound (EUS), using an echo colonoscope (CF-UM 3, CF-UM 20, Olympus optical) to computed tomography (CT), body coil magnetic resonance imaging (MRI) and endorectal coil magnetic resonance imaging (EMRI).

PATIENTS AND METHODS

From February 1991 to July 1993 90 patients with primary rectosigmoidal tumors (n = 32: 9 women, 23 men, mean age 68 years [range 37 to 84]) or follow-up examinations for recurrent local cancer (patients: n = 58, examinations: n = 93; 41 women, 52 men, mean age 61 years [range 31 to 84]) were investigated. The results of preoperative examinations were compared to histopathological findings regarding T and N stages.

RESULTS

In T staging, accuracy of EUS (78%) was superior to CT (50%) and equivalent to both MRI (75%) and EMRI (80%). The accuracy of EUS (84%) in assessing transmural tumor infiltration was superior to CT, MRT and EMRT (50%, 75% and 80%, resp.); however, CT (77%) and MRI (86%) were more accurate than EUS (64%) and EMRI (33%) in assessing N stages. Recurrent local cancer was found in 22 patients. All but one were detected by EUS. Sensitivity, specificity and accuracy in follow-up examinations for recurrent disease for EUS were 95%, 94% and 95%, for CT 75%, 73% and 74%, for MRI 57%, 100% and 70%, and for EMRI 83%, 100% and 90% resp.

CONCLUSIONS

Endoscopic ultrasound proved to be a safe and accurate method of preoperative staging and early diagnosis of recurrent rectal cancer and was superior or at least equivalent to CT, MRI and EMRI.