EUELC project: a multi-centre, multipurpose study to investigate early stage NSCLC, and to establish a biobank for ongoing collaboration

The European Early Lung Cancer (EUELC) project aims to determine if specific genetic alterations occurring in lung carcinogenesis are detectable in the respiratory epithelium. In order to pursue this objective, nonsmall cell lung cancer (NSCLC) patients with a very high risk of developing progressive lung cancer were recruited from 12 centres in eight European countries: France, Germany, southern Ireland, Italy, the Netherlands, Poland, Spain and the UK. In addition, NSCLC patients were followed up every 6 months for 36 months. A European Bronchial Tissue Bank was set up at the University of Liverpool (Liverpool, UK) to optimise the use of biological specimens. The molecular-pathological investigations were subdivided into specific work packages that were delivered by EUELC Partners. The work packages encompassed mutational analysis, genetic instability, methylation profiling, expression profiling utilising immunohistochemistry and chip-based technologies, as well as in-depth analysis of FHIT and RARbeta genes, the telomerase catalytic subunit hTERT and genotyping of susceptibility genes in specific pathways. The EUELC project engendered a tremendous collaborative effort, and it enabled the EUELC Partners to establish protocols for assessing molecular biomarkers in early lung cancer with the view to using such biomarkers for early diagnosis and as intermediate end-points in future chemopreventive programmes.

[Endobronchial ultrasound for diagnosis of the mediastinum]

The development of endobronchial ultrasound (EBUS) is one of the most important advances in bronchoscopy in recent years. Two different techniques are available which improve sonographic diagnostics of the mediastinum and staging in patients with lung and non-lung cancer. Radial EBUS and the technique of ultrasound-controlled transbronchial needle aspiration (TBNA) are now routine practice in many pulmonary centers. Their clinical application and diagnostic benefit have been established in many studies comparing them with conventional radiologic methods and other diagnostic procedures. Endobronchial ultrasound as a diagnostic tool is expected to gain importance in the near future. Especially the method combining EBUS and TBNA may replace more invasive methods such as mediastinoscopy for evaluating patients with unknown mediastinal lesions or for staging patients with lung cancer.

Lactate down-regulates cellular poly(ADP-ribose) formation in cultured human skin fibroblasts

BACKGROUND

Polyadenosine diphosphate-ribose (poly(ADP-ribose)) is a nuclear polymer which is derived from nicotinamide adenine dinucleotide (NAD(+)) catalysed by poly(ADP-ribose) polymerase 1 (PARP-1). Aside from the well known role of poly(ADP-ribosyl)ation (pADPR) in DNA repair, pADPR is also involved in other cellular processes such as apoptosis and gene expression. However, the factors that regulate the level of pADPR are not fully elucidated. In view of the fact that healing wounds contain high concentrations of lactate (10-15 mM) and exogenous lactate reduce the NAD(+) pool in cultured fibroblasts, we propose that high lactate lowers the level of nuclear pADPR.

MATERIALS AND METHODS

Neonatal human dermal fibroblasts (NHDF) were plated to subconfluence and allowed to adhere. Cells were treated with 15 mM l-lactate and pADPR production was assessed by immunofluorescence analysis using 10H antibody. Difference in pADPR production was determined by calculation of positively stained cells compared to total cell numbers. Inhibition of PARP activity was tested by treatment with 100 microM 3-aminobenzamide (3-AB). Specificity of the lactate effect on pADPR synthesis was verified by using the analogue d-lactate. The contents of nicotinamide adenine dinucleotide (NAD(+)) and its reduced form (NADH) in lactated and non-lactated cell cultures were quantified by the enzymatic cyclic assay.

RESULTS

We found that exogenous l-lactate (15 mM) can significantly depress pADPR content in cultured fibroblasts. PARP-1 activity was inhibited by 3-AB and analogue d-lactate showed no effect on pADPR synthesis. NAD(+)/NADH ratio was significantly lowered in lactated compared to non-lactated cell culture.

CONCLUSIONS

Exogenous l-lactate (15 mM) can depress pADPR content in cultured fibroblasts. In view of the fact that healing wounds contain such high concentrations of lactate, we propose that down regulation of pADPR is associated with elevated tissue repair via pADPR dependent gene expression. This observation is important in understanding the stimulation of lactate-mediated protein expression during wound healing.

Endobronchial ultrasound-guided transbronchial lung biopsy in fluoroscopically invisible solitary pulmonary nodules: a prospective trial

STUDY OBJECTIVES

Transbronchial biopsy (TBBX) for solitary pulmonary nodules (SPNs) is usually performed under fluoroscopic guidance, but the diagnostic yield depends on lesion size and varies widely. Nodules < 3 cm frequently cannot be visualized fluoroscopically. An alternative guidance technique, endobronchial ultrasound (EBUS), also allows visualization of pulmonary nodules. This study assessed the diagnostic yield of EBUS-guided TBBX in fluoroscopically invisible SPNs.

DESIGN

The study was a prospective trial using a crossover design.

PATIENTS AND METHODS

All patients with SPNs and indications for bronchoscopy were included in the study. An EBUS-guided examination was performed in patients with fluoroscopically invisible nodules. The EBUS probe was introduced through a guide catheter into the presumed segment. If a typical ultrasonic picture of solid tissue could be seen, the probe was removed and the catheter left in place. The biopsy forceps were introduced and specimens taken.

RESULTS

One hundred thirty-eight consecutive patients with SPNs were examined. Of those, 54 patients presented with SPNs that could not be visualized with fluoroscopy. The mean diameter of the nodules was 2.2 cm. In 48 patients (89%), the lesion was localized with EBUS, and in 38 patients (70%) the biopsy established the diagnosis. The 16 patients with undiagnosed SPNs were referred for surgical biopsy; 10 of those lesions were malignant and 6 were benign. The diagnosis in nine patients (17%) saved the patients from having to undergo a surgical procedure. The only complication was a pneumothorax in one patient.

CONCLUSIONS

EBUS-guided TBBX is a safe and very effective method for SPNs that cannot be visualized by fluoroscopy. The procedure may increase the yield of endoscopic biopsy in patients with these nodules and avert the need for surgical procedures.

Long-term outcome of conservative treatment in patients with diverticulitis of the sigmoid colon

INTRODUCTION

The indication for surgery after conservative treatment of acute diverticulitis is still under debate. This is partly as a result of limited data on the outcome of conservative management in the long run. We therefore aimed to determine the long-term results of conservative treatment for acute diverticulitis.

METHODS

The records of all patients treated at our institution for diverticulitis between 1985 and 1991 were reviewed (n=363, median age 64 years, range 29-93). Patients who received conservative treatment were interviewed in 1996 and 2002 [follow-up time 7 years 2 months (range 58-127 months) and 13 years 4 months (range 130-196 months).

RESULTS

A total of 252 patients (69%) were treated conservatively, whereas 111 (31%) were operated on. At the first follow-up, 85 patients treated conservatively had died, one of them from bleeding diverticula. A recurrence of symptoms was reported by 78 of the remaining 167 patients, and 13 underwent surgery. At the second follow-up, one patient had died from sepsis after perforation during another episode of diverticulitis. Thirty-one of the 85 patients interviewed reported symptoms and 12 had been operated on. In summary, at the second follow-up interview, 34% of patients treated initially had had a recurrence and 10% had undergone surgery. No predictive factors for the recurrence of symptoms or later surgery could be determined.

CONCLUSION

Despite a high rate of recurrences after conservative treatment of acute diverticulitis, lethal complications are rare. Surgery should thus mainly be undertaken to achieve relief of symptoms rather than to prevent death from complications.

[Design and use of patient pathways in general surgery]

BACKGROUND

Clinical pathways are a new initiative intended to reduce costs while maintaining or even improving the quality of care. Based on treatment guidelines, patient pathways display an optimal sequence of staff actions in the preoperative, operative, and postoperative in- and outpatient treatment.

METHODS

In this study, patient pathways were developed for selected elective general surgical disease entities following a new modular approach. All elements of care and their direct costs to the hospital were identified. Multidisciplinary teams of physicians, nurses, and administrative staff constructed and implemented the patient pathways.

RESULTS

In the 1-year pilot phase, we developed and implemented 7 pathways with 16 subpathways: open herniorrhaphy, laparoscopic cholecystectomy and fundoplication, thyroidectomy, surgical treatment of diverticulitis and colon carcinoma and kidney transplantation.

CONCLUSIONS

Patient pathways combine the management of care, hospital processes, and costs in a new integrated concept. Patient pathways streamline and standardize care, facilitate communication, and contribute to cost control efforts.

Encapsulation of islets in rough surface, hydroxymethylated polysulfone capillaries stimulates VEGF release and promotes vascularization after transplantation

The transplantation of encapsulated islets of Langerhans is one approach to treat type 1 diabetes without the need of lifelong immunosuppression. Capillaries have been used for macroencapsulation because they have a favorable surface-to-volume ratio and because they can be refilled. It is unclear at present whether the outer surface of such capillaries should be smooth to prevent, or rough to promote, cell adhesions. In this study we tested a new capillary made of modified polysulfone (MWCO: 50 kDa) with a rough, open-porous outer surface for islet transplantation. Compared with free-floating islets, encapsulation of freshly isolated rat islets affected neither the kinetics nor the efficiency of glucose-induced insulin release in perifusion experiments. Free-floating islets maintained insulin secretion during cell culture but encapsulated islets gradually lost their glucose responsiveness and released VEGF. This indicated hypoxia in the capillary lumen. Transplantation of encapsulated rat islets into diabetic rats significantly reduced blood glucose concentrations from the first week of implantation. This hypoglycaemic effect persisted until explantation 4 weeks later. Transplantation of encapsulated porcine islets into diabetic rats reduced blood glucose concentrations depending on the islet purity. With semipurified islets a transient reduction of blood glucose concentrations was observed (2, 8, 18, 18 days) whereas with highly purified islets a sustained normoglycaemia was achieved (more than 28 days). Explanted capillaries containing rat islets were covered with blood vessels. Vascularization was also observed on capillaries containing porcine islets that were explanted from normoglycaemic rats. In contrast, on capillaries containing porcine islets that were explanted from hyperglycemic rats a fibrous capsule and lymphocyte accumulations were observed. No vascularization on the surface of transplanted capillaries was observed in the absence of islets. In conclusion, encapsulated islets can release VEGF, which appears to be an important signal for the vascularization of the capillary material. The rough, open-porous outer surface of the polysulfone capillary provides a site well suited for vascular tissue formation and may allow a prolonged islet function after transplantation.

Stimulation of fibroblast proliferation by lactate-mediated oxidants

Lactate accumulation is a characteristic of wounds in which glycolysis, occurring both aerobically and anaerobically, contributes to its production. Cell proliferation is a critical component of healing wounds. Recently it has been shown that lactate can chelate iron and thus promotes production of hydroxyl radicals. We report here that exogenous lactate increases intracellular oxidants and that the oxidants promote cell growth in cultured dermal fibroblasts in a dose-dependent manner. The production of lactate-mediated oxidant requires iron and hydrogen peroxide and with increasing iron concentration oxidant production is raised as well. However, we found cell proliferation is retarded by 15 mM lactate in the presence of a high iron concentration (7.25 microM). The antioxidants catalase and mannitol abolish the inhibitory effect of high lactate. We conclude from these results that increased proliferation of cultured human fibroblasts by exogenous lactate is mediated by oxidant production.

Postoperative colonic motility increases after early food intake in patients undergoing colorectal surgery

BACKGROUND

Stimulation of colonic motility by the gastrocolonic response may help to reduce inhibition of gastrointestinal motility after colorectal surgery. We aimed to investigate whether postoperative colonic motility is increased after early food intake.

METHODS

Nineteen patients undergoing colorectal surgery and 7 healthy volunteers were investigated. Colonic motility was recorded with a combined manometry/barostat system, and the effect of a standard 500-kcal meal was evaluated once in healthy volunteers and in 15 patients on the first and second postoperative day. Four patients remained unfed, serving as controls.

RESULTS

In patients, the colonic motility index increased from 12 +/- 5 at baseline to 65 +/- 24 mm Hg after the meal on postoperative day 1 (mean +/- SEM; P < .01), while barostat bag volumes decreased, indicating a rise in colonic tone. On day 2, the motility index was 62 +/- 17 mm Hg at baseline and did not change after the meal. In unfed controls, no change was observed during colonic motility recordings on both postoperative days. In healthy volunteers, the colonic motility index increased from 98 +/- 52 at baseline to 151 +/- 58 mm Hg postprandially (P < .05).

CONCLUSIONS

As in healthy volunteers, there is a potential to stimulate colonic motility by early food intake in postoperative patients. This may help to improve prolonged colonic motility disorders after colorectal surgery.

Functional asymmetry of pelvic floor innervation and its role in the pathogenesis of fecal incontinence

While the regular and symmetric innervation of the pelvic floor has been regarded as "established" for many years, recent data indicate that asymmetry of innervation of the sphincters may exists and may contribute to the occurrence and severity of incontinence symptoms in case of pelvic floor trauma.

METHODS

A systematic review of published papers on asymmetry of sphincter innervation was performed including studies in healthy volunteers and patients with incontinence. 234 consecutive patients with fecal incontinence were investigated by means of side-separated mass surface EMG from the left and right side anal canal, these data were correlated to clinical and anamnestic findings.

RESULTS

The literature survey indicates that asymmetry of sphincter innervation exists in a subgroup of healthy male and female volunteers, and may be a risk factor to become incontinent in case of trauma. Patients with incontinence in whom asymmetry of sphincter innervation could be shown more frequently reported a history of pelvic floor trauma during childbirth. Childbirth per se but not the number of deliveries predicted sphincter asymmetry. Asymmetrically innervated sphincters show a compromised sphincter function in routine anorectal manometry.

CONCLUSION

Assessment of sphincter innervation asymmetry may be of value in clinical routine testing of patients with incontinence. However, a new technology is needed to replace mass surface EMG by multi-electrode arrays on a sphincter probe. This is one of the goals of the EU-sponsored research project OASIS.

Korrekturm�glichkeiten der gest�rten Wundheilung

Chronic wounds are long-term results of various diseases. Evaluation and therapy of the underlying disorder must be the first goal of a comprehensive wound care protocol. Treatment of local (i.e. wound infection, necrosis, or foreign body) or systemic (i.e. diabetes, immunosuppression, or patient compliance) disturbing factors is the second major step for appropriate wound care. The third major point is wound bed preparation (i.e. debridement, moist wound dressings, or VAC therapy), and wound stimulation. After appropriate wound bed preparation, wounds can be closed by plastic surgery or wound stimulation through various agents (i.e. protease inhibitors, growth factors, or tissue engineering).

[Endobronchial ultrasound in bronchial carcinoma]

Conventional imaging procedures proved to be insufficient for staging of lung cancer especially with respect of N-stage, infiltration of mediastinal structures and early lung cancer. As also the view of the endoscopist is restricted we developed the new method of endobronchial ultrasonography (EBUS) as adjunct to conventional bronchoscopy. The initial technical problems were solved by development of a balloon catheter for application of miniaturized 20 MHz probes. EBUS is a new technology that can be easily applied and is well tolerated. It improves the results of bronchoscopy in addition to conventional diagnostic procedures. Further developments will be made in future to improve the application of ultrasound in chest medicine.

Lactate and oxygen constitute a fundamental regulatory mechanism in wound healing

For many years, lactate has been known to accelerate collagen deposition in cultured fibroblasts and, without detailed explanation, has been presumed to stimulate angiogenesis. Similarly, hypoxia has been linked to angiogenic effects and collagen deposition from cultured cells. Paradoxically, however, wound angiogenesis and collagen deposition are increased by breathing oxygen and decreased by hypoxia. Lactate accumulates to 4-12 mM in wounds for several reasons, only one of which is the result of hypoxia. Oxygen in wounds is usually low but can be increased by breathing oxygen (without change in lactate). We have reported that lactate elicits vascular endothelial growth factor (VECF) from macrophages, as well as collagen, some heat shock proteins, and VECF from endothelial cells, and collagen from fibroblasts, even in the presence of normal amounts of oxygen. Hypoxia exerts many of these same effects in cultured cells. In this study, we elevated extracellular lactate in wounds by implanting purified solid-state, hydrolysable polyglycolide. A steady-state 2-3 mM additional elevation of lactate resulted. With it, there was a significant short-term elevation of interleukin-1beta, a long-term elevation of VECF (2x) and transforming growth factor-beta1 (2-3x), a 50% elevation in collagen deposition, and a large reduction of insulin-like growth factor-1 (- 90%). We propose that lactate induces a biochemical "perception" of hypoxia and instigates several signals that activate growth factor/cytokine signals while the continued presence of molecular oxygen allows endothelial cells and fibroblasts to reproduce and deposit collagen. The data are consistent with ADP-ribosylation effects and oxidant signaling. (WOUND REP REG 2003;11:504-509)

Areal density measurement is a convenient method for the determination of porcine islet equivalents without counting and sizing individual islets

The determination of islet mass is important for the normalization of islet experiments in the laboratory and for the precise dosing of islets for transplantation. The common microscopical analysis is based on individual islet sizing, calculation of the frequency distribution, and conversion into islet equivalents (IEQ), which is the volume of a spherical islet with a diameter of 150 microm. However, islets are of irregular form, which makes this determination user dependent, and the analysis is irreproducible once the original sample is discarded. This routine technique of islet quantification was compared with the analysis of areal density measurements. It was assumed that the entire area occupied by islets can be expressed in IEQ without sizing and counting individual islets. Porcine islets were isolated by continuous digestion/filtration and purified by gradient centrifugation. Purified islets were stained with dithizone and were repeatedly pictured under the microscope with random area selection. A total of 51 pictures was taken from 11 different purifications and stained islets were detected by digital image analysis. The correlation coefficient (r) between bothanalyses was 0.977 with an underestimation of islet yield by areal density detection (slope: 0.75 +/- 0.03). Areal density analysis per picture took about 1 min, which is about 10 times faster than the traditional method without increasing the method error (CV 2.1% vs. 2.7%). In summary, areal density measurements allow a rapid and reproducible estimation of IEQ without counting individual islets. It can be performed in a single step analysis without computer programming and is valuable for online determinations of islet yield preceding transplantation.

Postoperative colonic motility in patients following laparoscopic-assisted and open sigmoid colectomy

Clinical reports on laparoscopic-assisted sigmoid colectomy (LASC) suggest that the period of postoperative inhibition of gastrointestinal motility is shortened as compared to open sigmoid colectomy (OSC). We aimed to specifically investigate whether colonic motility increases more rapidly following LASC compared to OSC. LASC was performed in 11 patients and OSC in nine patients for recurrent diverticulitis or carcinoma. During surgery a manometry catheter was inserted into the colon via the anus, and the tip was placed in the splenic flexure. Continuous manometric recordings were performed from the day of surgery until postoperative day 3 with a four-channel microtransducer manometry system combined with a portable data logger. The postoperative colonic motility index was 101+/-18, 199+/-30, and 163+/-27 mm Hg/min on days 1, 2, and 3 after LASC, respectively, which was increased compared to indexes of 53+/-15, 71+/-18, and 76+/-23 following OSC (mean+/-standard error of the mean; P<0.05). The amplitude but not the frequency of contractions was higher following LASC compared to OSC. Following LASC, patients requested a similar amount of pain medication but resumed oral food more rapidly on postoperative days 2 and 3 (P<0.05), and they were discharged from the hospital earlier (P<0.05). Colonic motility in particular and the patient's condition in general seem to improve more rapidly following LASC compared to the open procedure.

Treatment of advanced rectal cancer in a patient after combined pancreas-kidney transplantation

BACKGROUND

Organ transplantation is a standard procedure today. Due to immunosuppressive drugs and increasing survival after organ transplantation, patients with transplanted organs carry an increased risk of developing malignant tumours. Accordingly, more patients with malignant tumours after transplantation will be faced by general or oncology surgeons. We report the case of a 48-year-old patient with advanced rectal cancer 6.5 years after pancreas-kidney-transplantation for type I diabetes.

METHOD

The patient was treated with neo-adjuvant radio-chemotherapy, followed by low anterior rectal resection with total mesorectal excision. Consecutively, a solitary hepatic metastasis, a solitary pulmonary metastasis and a chest wall metastasis were resected over the course of 13 months.

RESULT

The patient eventually died of metastasized cancer 32 months after therapy had been initiated, his organ grafts functioning well until his death.

CONCLUSION

Our case report provides evidence that transplantation patients should receive standard oncology treatment, including neo-adjuvant treatment, so long as their general condition and organ graft functions allow us to do so, although a higher degree of morbidity might be encountered.

Autofluorescence Bronchoscopy – A Comparison of Two Systems (LIFE and D-Light)

BACKGROUND

Autofluorescense (AF) bronchoscopy is an established method to detect dysplasia and carcinoma in situ (CIS). Several different systems are currently available.

OBJECTIVES

This study aimed to directly compare the LIFE system (Xillix Technologies, Vancouver, Canada) and the D-light system (Storz, Tuttlingen, Germany).

METHODS

In a prospective study performed between May 1999 and October 2000, we examined patients with risk factors for lung cancer that underwent bronchoscopy with both (LIFE and D-light) systems in a crossover design. The findings were classified into normal, abnormal and suspicious lesions by independent investigators and then compared.

RESULTS

This study comprised 332 patients (220 males, 112 females, mean age 62.7 years, range 40-85); 1,117 biopsies were studied (mean biopsy rate 3.4/patient). In 817 biopsies, mucosal areas were classified as normal with respect to control biopsy specimens, 113 as abnormal and 187 as suspicious using AF bronchoscopy. The histological examination showed normal tissue in 850 cases, in 55 cases scarring or inflammation, in 62 meta- or dysplasias, in 11 carcinomas in situ and in 127 invasive tumors. In only 5 cases, classifications were found to be different between the two systems (2 normal, 2 dysplasias, 1 invasive tumor). The mean time for the LIFE system examination amounted to 11.7 min (range 6.2-19.5) and for the D-light system to 7.4 min (range 4.3-11.9). This difference was statistically significant (p < 0.001).

CONCLUSION

Both systems yielded comparable results. The examination time was significantly shorter with the D-light system, which may be explained by the more comfortable handling and the direct switch between white light and AF imaging. Different trials using either methodology could be compared directly.

[The role of a radical surgical debridement and mesh graft tissue transfer for treatment of venous ulcers]

Many studies are published demonstrating remarkable results of skin grafting in venous ulcers, but only a few controlled randomised trials including a low number of patients are available. A review based on two controlled randomised trials concludes that there is no significant benefit for mesh graft tissue transfer compared to standard treatment. However, in all studies no adequate initial radical surgical debridement including fasciectomy for wound bed preparation has been performed. In a prospective study on 57 patients with venous ulceration we found significant lower recurrence rates after mesh graft tissue transfer and radical surgical debridement. In clinical practice the results of mesh graft tissue transfer following surgical debridement in the management of larger chronic venous ulcers have been encouraging, although the evidence-based recommendation is lacking. It may not be the treatment of first choice and should be preserved for large ulcers of long duration or history of recurrence. There is need for more randomised controlled studies comparing also cost effectiveness while ensuring baseline comparability.

Comparison of inflammatory and systemic sources of growth factors in acute and chronic human wounds

Inflammatory cells are generally assumed to be the primary source of most growth factors/cytokines that participate in wound healing. Correspondingly, most attempts to enhance wound healing have been directed at the wound itself. However, certain key factors such as insulin-like growth factor-I (IGF-I) and related proteins are present in blood in sufficient quantities to suggest significant contributions from outside the wound. Because little is known of the dynamics of IGF family members in wounds, particularly in human wounds, we serially measured the mRNAs and proteins of the IGF family in fluid and tissues taken from acute as well as chronically inflamed human wounds and compared them to their corresponding concentrations in blood. We also measured transforming growth factor-beta1 and -beta3, vascular endothelial growth factor, interleukin-1beta, matrix metalloproteinases and selected isomers/receptors, all of which are associated with inflammation. All IGF proteins reached their highest concentrations immediately after injury. No difference between IGF-I mRNA expression between acute and inflamed wounds was found. As a group, IGF-related proteins, in contrast to transforming growth factor-beta, vascular endothelial growth factor, and interleukin-1beta, are highly correlated to and are generally below their concentrations in blood and are not elevated by inflammation. The IGF family therefore appears to enter wounds, even inflamed wounds, mainly from blood. If blood IGF-I is low, wound levels are lower. This data suggests that healing impairment due to IGF-I deficiency can be readily detected and is, at least in part, easily and safely correctable.

Evaluation of the barostat for recordings of gastrointestinal motility

BACKGROUND

The barostat has been used to investigate gastrointestinal motility. No detailed technical evaluation to characterize the properties of this device for motility recordings has been reported. We, therefore, aimed to test the barostat in vitro under standardized conditions.

METHODS

Barostat and manometry recordings were performed using a combined catheter in a pressure chamber. Some of the experiments were made in pig sigmoid colon in order to mimic recordings in a hollow organ. Data are mean +/- SD.

RESULTS

Baseline changes of the bag volume under constant conditions were 3.9 +/- 2.0%. The bag volume increased by 4.5 +/- 1.1% with a temperature increase from 22 to 37 degrees C (p < 0.05). At external pressures above the bag operating pressure, the barostat bag collapsed, while only minimal volume reductions occurred at external pressures below the bag pressure. Barostat recordings of pressure events were delayed when compared with manometry and not linearly related to the pressure increases.

CONCLUSION

The influence of temperature changes on barostat recordings is small. The volume decrease in the barostat bag is not linearly related to the external pressure increase and influenced by the operating pressure in the bag. This experimental study provides insight and caveats for those planning to use the barostat device for motility recordings of the gastrointestinal tract.

[Postoperative ileus: part II (Clinical therapy)]

To avoid or reduce postoperative ileus, the operative trauma should be minimized and epidural anesthesia for spinal inhibition of the sympathetic nervous system or i. v. lidocaine should be used, all of which probably act by reducing visceral afferent nerve fiber activity. Recent data suggest that perioperative fluid restriction might reduce postoperative ileus. Epidural anesthesia with local anesthetics and replacing opioids by non-steroidal anti-inflammatory drugs (NSAIDs) for postoperative pain treatment improve the recovery of gastrointestinal motility disturbances. Prior to the operation, the patient should be informed regarding postoperative motility disorders, its length and the presumed resumption of oral food intake, which has been shown to shorten hospital stay. Early postoperative food intake stimulates small and large bowel motility via interenteric reflex arches, avoids i. v. lines and renders discharge acceptable for the patient. Treatment of postoperative ileus includes osmotic laxatives and prokinetic drugs like erythromycine and acetylcholinesterase inhibitors. By combining epidural anesthesia and the sparse use of i. v. opioids with early food intake and, if necessary, laxatives or prokinetics, postoperative ileus should be coped adequately. Nevertheless, the development of new specific prokinetic drugs with minimal or no side effects should remain a target for drug companies to further improve treatment of postoperative ileus.

Arginase acts as an alternative pathway of L-arginine metabolism in experimental colon anastomosis

L-Arginine is the substrate for the nitric oxide synthase (NOS) pathway that is essential for gastrointestinal wound healing. L-Arginine is also the substrate for the enzyme arginase which metabolizes L-arginine to ornithine and subsequently to proline and polyamines both known to interact in cell proliferation and collagen synthesis. Two distinct isoforms of arginase exist. The temporal expression of the L-arginine metabolism in experimental colon anastomosis was investigated. Male Lewis rats underwent laparotomy. A left-sided colotomy was performed and the colon reanastomosed using 6-0 prolene. Sham operation was performed in controls. On days 2, 5, 10, 14, and 28 after the surgery the anastomosis was excised. The tissue at the anastomosis (ANAST) as well as above and below the anastomosis (PDC) and from sham colon was harvested and analyzed for distinct arginase isoform I (AI) and arginase isoform II (AII) activity, protein and mRNA expression as well as immunohistochemistry. iNOS protein and mRNA expression were investigated in parallel. A mean of 3 to 4 separate rats were analyzed per time point. Statistical analysis was performed by student's t-test, significance was reached when P < 0.05. AI activity, protein, and mRNA expression were significantly upregulated at the anastomosis compared to sham controls and PDC colons at all time points. The maximum was achieved at days 10 to 14 after wounding, and decreased to baseline levels thereafter. Inflammatory cells stained positive for AI. AII protein was not detectable. However RT-PCR showed low baseline expression. iNOS expression was upregulated early but for a shorter time period after wounding and reverted quickly to undetectable levels. In anastomotic healing, AI upregulation suggests a prolonged metabolism of arginine via arginase to polyamines and proline to provide substrate for collagen synthesis and cell proliferation. The functional implication of this arginase pathway further needs to be elucidated.

Xanthogranulomatous cholecystitis resembling carcinoma with extensive tumorous infiltration of the liver and colon

BACKGROUND

Xanthogranulomatous cholecystitis is a macrophage-rich inflammatory condition of the gallbladder that occasionally presents with tumorlike appearance.

CASE PRESENTATION

In the present case the inflammation involved all the layers of the gallbladder, the surrounding connective tissue, and part of the right lobe of the liver and right transverse colon. The clinical and radiological findings were suggestive of advanced carcinoma of the gallbladder. However, intraoperative frozen section investigation revealed xanthogranulomatous cholecystitis, for which simple cholecystectomy is the treatment of choice.

CONCLUSIONS

The original cause of the condition is unclear in most cases. In the present case it is possible that rupture of the gallbladder in association with the patient's known history of trauma have initiated the process.

Transthoracic ultrasound

Sonography (US) has inherent limitations for thoracic imaging because sound waves are reflected by bone and air space (such as in lung parenchyma). However, US is less expensive and more convenient than computed tomography (CT) or magnetic resonance imaging (MRI); it provides immediate information with real-time imaging, and can give information not available from a standard radiograph. This review describes the utility and limitations of US and compares US with radiography.

Aspirin does not increase bleeding complications after transbronchial biopsy

STUDY OBJECTIVES

The present study was performed to determine whether the risk of bleeding after transbronchial lung biopsy is increased in patients taking aspirin.

DESIGN

Prospective cohort study.

PATIENTS AND INTERVENTIONS

After excluding patients with other coagulation problems, 1,217 patients who had undergone transbronchial lung biopsy during a prospective 1.5-year study period were included in this study. The use of aspirin was not discontinued before the procedure. Two hundred eighty-five patients (23%) had consumed aspirin within 24 h of the procedure, and most of them (82%) used aspirin on a daily basis. Transbronchial biopsies were performed, and the bleeding incidence was compared between the groups.

RESULTS

A total of 57 patients (4.7%) experienced procedure-related bleeding. Minor bleeding occurred in 5 of 285 patients (1.8%) taking aspirin and in 27 of 932 control patients (2.9%; not significant). Moderate bleeding was seen in 3 of 285 patients (1.1%) in the aspirin group and in 13 of 932 patients (1.4%) in the control group (not significant). Major bleeding occurred in only 9 patients, 2 of 285 (0.9%) in the aspirin group and 7 of 932 (0.8%) in the control group (not significant). All bleeding was controlled by endoscopic means, and there were no fatalities and no need for blood transfusions.

CONCLUSIONS

We conclude that the risk of severe bleeding after transbronchial lung biopsy is small (ie, < 1%) and that the use of aspirin is not associated with any increased risk of bleeding.

Cultivation of porcine hepatocytes in polyurethane nonwovens as part of a biohybrid liver support system

Many patients suffering from end-stage liver disease cannot be transplanted within reasonable time due to the shortage of donor organs. Bioartificial liver support systems may contribute to the liver regeneration or bridging the time until a liver graft for transplantation becomes available. Nonwovens with integrated oxygenation capacity have been developed and manufactured by melt blow technology using thermoplastic polyurethane. Capillary membranes for oxygenation were integrated into the nonwoven during the processing. The polyurethane nonwoven structures with adapted pore size and high pore volume allow high cell densities in the hepatocyte culture. The three-dimensional cell culture was housed by a flow bioreactor system and was integrated in a closed loop circulation with monitoring possibilities for pressure, pH, temperature, ammonia, and oxygen. Hepatocytes were isolated from rats or pigs by collagenase perfusion and infused into the medium-perfused circulation. Cells showed high viability and hepatocyte specific cytochrome P450-dependent metabolic function in culture (MEGX test).

Endobronchial ultrasound-guided transbronchial lung biopsy in solitary pulmonary nodules and peripheral lesions

Transbronchial biopsy (TBBX) for peripheral lung lesions is usually performed with the help of fluoroscopy, but the yield varies widely. This feasibility study aimed to assess the ability of endobronchial ultrasound (EBUS) to provide imaging guidance for TBBX. In a prospective study, 50 consecutive patients referred for TBBX for peripheral lesions underwent fluoroscopy-guided and EBUS-guided TBBX in random order. Diagnostic yields were compared for both modalities and feasibility was assessed for EBUS. Diagnostic material was obtained in 80% of patients with EBUS and 76% of patients with fluoroscopy. There was a nonsignificant trend for EBUS to be better than fluoroscopy for lesions <3 cm in diameter. Four lesions could not be visualised with EBUS. There were no significant complications associated with the use of EBUS. Endobronchial ultrasound-guided transbronchial biopsy is feasible. It appears to be at least equivalent to fluoroscopy without the accompanying radiation exposure. Further large-scale studies are indicated to assess the possible role of endobronchial ultrasound as a potential imaging method of choice for the biopsy of peripheral lung lesions.

Anorectal functional disorders in the absence of anorectal inflammation in patients with Crohn's disease

BACKGROUND

Histological alterations in the enteric nervous system (ENS) have been described in patients suffering from Crohn's disease (CD). The aim of this study was to investigate whether patients with CD without rectal inflammation have abnormal anorectal function compared with healthy volunteers.

METHODS

Fifty-four patients with CD and 26 healthy volunteers were examined by anorectal manometry and answered a standardized questionnaire. No patient had active CD in the rectum as determined by endoscopy.

RESULTS

Maximum anal resting and squeeze pressures did not differ between patients and healthy volunteers. The rectoanal inhibitory reflex was absent in 24 of 54 patients and two of 26 healthy volunteers (P < 0.05). The first sensation to distension of the rectal balloon was reported at mean(s.e.m.) 57.9(4.4) ml by patients and 37.5(2.2) ml by healthy volunteers (P < 0.01). The standardized interview revealed additional disorders of anorectal function in patients with CD.

CONCLUSION

Anorectal function appears to be altered in many patients with CD even in the absence of macroscopic anorectal disease. This may be due to a disorder of the ENS.

[Endobronchial ultrasound for local tumour and lymph node staging in patients with centrally growing lung cancer]

AIM

Lung cancer is a common disease and exact staging is of extreme importance in order to plan therapy. A frequent problem in assessing the extent of tumour spread is the question of infiltration versus compression of central airways by central tumours and a correct lymph node staging. Chest CT as the general imaging procedure of choice is often not helpful with these questions. Endobronchial ultrasound (EBUS) has been available for several years, and we were interested to find out if the addition of EBUS to regular bronchoscopy can help to differentiate between airway infiltration and external compression and improves the yield of transbronchial needle aspiration (TBNA).

METHOD

Patients with central tumour growth and enlarged lymph nodes were examined with EBUS and CT, classified according to local tumour invasion, and a needle biopsy of the lymph nodes was performed after EBUS detection.

RESULTS

50 patients were examined and subsequently operated. Relative to the local T-staging EBUS resulted in a sensitivity of 89 % and a specificity of 100 %. The results were highly improved statistically compared to the CT results (sensitivity 25 %, specificity 80 %). With EBUS-guided TBNA the results of correct N-staging could be improved to 86 %.

CONCLUSION

Our study suggests that EBUS, if performed by experienced endoscopists for the detection of airway wall infiltration or compression is highly accurate and superior to chest CT in assessing potential airway infiltration by a malignant tumour. Furthermore, the results of the lymph node staging could be improved through the additional use of EBUS. It is easily performed within the context of a standard bronchoscopy and may spare many patients unnecessary surgical biopsies.

Serotonin receptor blockade increases food intake and body weight after total gastrectomy in rats

BACKGROUND

Total gastrectomy often results in early satiety and loss of body weight. Serotonin inhibits food intake, and postprandial serotonin release is increased after total gastrectomy. Serotonin might contribute to early satiety and loss of body weight after total gastrectomy.

METHODS AND MATERIALS

Food intake and body weight were investigated with an automated recording system in gastrectomized rats 1-12 months postoperatively. Rats were treated with metergoline, a 5-hydroxytryptamine (5-HT)(1/2) receptor antagonist, two different 5-HT(3) receptor antagonists, a combination of metergoline and devazepide, a cholecystokinin (CCK) a receptor antagonist, or vehicle. In addition, metergoline or vehicle was applied continuously by an intraperitoneal osmotic minipump for 7, 28, or 84 days after total gastrectomy.

RESULTS

Metergoline treatment resulted in a dose-dependent increase in food intake in gastrectomized rats. 5-HT(3) receptor antagonist treatment had no effect, and devazepide in addition to metergoline did not further stimulate food intake. Metergoline increased food intake at 1, 3, and 6 months postoperatively by up to 45% (24-h cumulative food intake [FI], 6 months: vehicle 3.83 +/- 0.10, metergoline 5.52 +/- 0.15 g/100 g body weight (BW), P < 0.0001). Chronic metergoline treatment for 7, 28, or 84 days significantly increased food intake after total gastrectomy compared to vehicle treatment (FI 7 days: vehicle 30.83 +/- 0.71, metergoline 36.27 +/- 0.85 g/100 g BW; P < 0.0002; average weekly FI during 28 days; vehicle 31.23 +/- 0.22, metergoline 36.83 +/- 0.33 g/100 g BW, P < 0.0001; average weekly FI during 84 days: vehicle 33.02 +/- 0.59, metergoline 35.07 +/- 0.48 g/100g BW, P < 0.008), and there was a significant body weight increase compared to vehicle treatment (7 days: DeltaBW vehicle -0.7 +/- 1.2 g vs DeltaBW metergoline 9.0 +/- 2.1 g, P < 0.001; 28 days: DeltaBW vehicle 0.3 +/- 2.2 vs DeltaBW metergoline 13.0 +/- 2.3, P < 0.001; 84 days: DeltaBW vehicle 25.7 +/- 10.2 vs DeltaBW metergoline 49.5 +/- 7.2, P < 0.04). Treatment for 84 days resulted in a significant body weight gain, while vehicle treatment had no effect (vehicle: 438 +/- 11 g vs 464 +/- 12 g, P < 0.2, n.s.; metergoline: 448 +/- 9 g vs 498 +/- 10 g, P < 0.007).

CONCLUSIONS

Inhibition of food intake by serotonin might contribute to early satiety and loss of body weight after total gastrectomy.

Total gastrectomy severely alters the central regulation of food intake in rats

OBJECTIVE

To investigate the central regulation of food intake by quantifying neuron activation of the nucleus of the solitary tract (NTS) after injection of cholecystokinin (CCK) or food intake in gastrectomized rats.

SUMMARY BACKGROUND DATA

Total gastrectomy is followed by early satiety, low calorie intake, and weight loss in the majority of patients. The etiology of these effects is unknown. Sixty percent to 70% of patients remain underweight after total gastrectomy, the weight loss averaging 25% of preoperative body weight. About two thirds of gastrectomized patients report early satiety, and about 60% do not reach the recommended daily calorie intake. The NTS is a brain stem center involved in the regulation of food intake; thus, the extent and pattern of neuronal activation provide information on the process involved in the initiation of satiation and the regulation of food intake.

METHODS

The authors investigated neuronal activation in the NTS using c-fos immunohistochemistry following CCK injection or food intake in healthy control rats, sham-operated control rats, age-matched control rats, weight-matched control rats, and vagotomized or gastrectomized rats.

RESULTS

Neuronal activation in the NTS after CCK injection was significantly decreased 21 days after total gastrectomy, but increased by up to 51% 3 months and by up to 102% 12 months after surgery compared to age-matched unoperated control rats. Neuronal activation in the NTS in response to feeding was markedly increased up to fivefold in gastrectomized rats. This increase was early in onset and sustained, and occurred despite significantly reduced food intake. Administration of MK329, a CCK-A receptor antagonist, significantly reduced the number of postprandially activated neurons in both gastrectomized and control rats.

CONCLUSIONS

The early postprandial activation of NTS neurons after total gastrectomy in rats may correspond to early satiety reported by patients, while the sustained activation of NTS neurons after a meal could contribute to a reduced daily calorie intake. These data suggest that a disturbed central regulation of food intake might contribute to early satiety, reduced food intake, and weight loss after total gastrectomy.

Endobronchial ultrasound in therapeutic bronchoscopy

Endobronchial ultrasound (EBUS) has been introduced as an adjunct to diagnostic bronchoscopy as it allows evaluation of the submucosal and parabronchial structures. Its use in therapeutic bronchoscopy has not been assessed. A large observational study of the value of EBUS in therapeutic bronchoscopy is presented here. From January 1998-January 2001 all patients undergoing therapeutic bronchoscopy and EBUS were evaluated prospectively. Patient demographics, indication for bronchoscopy, interventional treatments used and changes in therapy as influenced by the use of EBUS were documented. A total 2,446 therapeutic bronchoscopies were performed. In 1,174 cases EBUS was used (29% mechanical tumour debridement, 20% airway stenting, 13% Neodymium:yttrium aluminium garnet (Nd:YAG) laser use, 23% argon plasma coagulation, 11% brachytherapy, 2% foreign body removal and 2% endoscopic abscess drainage). EBUS guided or changed therapy significantly in 43% of cases. Changes included adjustment of stent dimensions, termination of tumour debridement when nearing vessels, and referral for surgical interventions rather than endoscopic treatment. Complications associated with EBUS use were minimal. No patient undergoing EBUS guided tumour destruction experienced severe bleeding or fistula formation. In summary, endobronchial ultrasound was easily performed and changed or guided therapeutic decisions during therapeutic bronchoscopic procedures in a substantial number of cases. As this may result in better outcomes, it has become a standard adjunct in the authors practice.

Genomics and the evolution of aminoacyl-tRNA synthesis

Translation is the process by which ribosomes direct protein synthesis using the genetic information contained in messenger RNA (mRNA). Transfer RNAs (tRNAs) are charged with an amino acid and brought to the ribosome, where they are paired with the corresponding trinucleotide codon in mRNA. The amino acid is attached to the nascent polypeptide and the ribosome moves on to the next codon. Thus, the sequential pairing of codons in mRNA with tRNA anticodons determines the order of amino acids in a protein. It is therefore imperative for accurate translation that tRNAs are only coupled to amino acids corresponding to the RNA anticodon. This is mostly, but not exclusively, achieved by the direct attachment of the appropriate amino acid to the 3'-end of the corresponding tRNA by the aminoacyl-tRNA synthetases. To ensure the accurate translation of genetic information, the aminoacyl-tRNA synthetases must display an extremely high level of substrate specificity. Despite this highly conserved function, recent studies arising from the analysis of whole genomes have shown a significant degree of evolutionary diversity in aminoacyl-tRNA synthesis. For example, non-canonical routes have been identified for the synthesis of Asn-tRNA, Cys-tRNA, Gln-tRNA and Lys-tRNA. Characterization of non-canonical aminoacyl-tRNA synthesis has revealed an unexpected level of evolutionary divergence and has also provided new insights into the possible precursors of contemporary aminoacyl-tRNA synthetases.