Translating surveillance data into incidence estimates

Monitoring a population for a disease requires the hosts to be sampled and tested for the pathogen. This results in sampling series from which we may estimate the disease incidence, i.e. the proportion of hosts infected. Existing estimation methods assume that disease incidence does not change between monitoring rounds, resulting in an underestimation of the disease incidence. In this paper, we develop an incidence estimation model accounting for epidemic growth with monitoring rounds that sample varying incidence. We also show how to accommodate the asymptomatic period that is the characteristic of most diseases. For practical use, we produce an approximation of the model, which is subsequently shown to be accurate for relevant epidemic and sampling parameters. Both the approximation and the full model are applied to stochastic spatial simulations of epidemics. The results prove their consistency for a very wide range of situations. The estimation model is made available as an online application. This article is part of the theme issue 'Modelling infectious disease outbreaks in humans, animals and plants: epidemic forecasting and control'. This theme issue is linked with the earlier issue 'Modelling infectious disease outbreaks in humans, animals and plants: approaches and important themes'.

Bariatric reduction system - BARS: device, technique and first clinical experience

BACKGROUND

Roux-en-Y gastric by-pass (RYGB) is one of the most effective bariatric procedures, but the rate of weight regain (WR) can reach 63% after the second year. Enlargement of the gastrojejunal anastomosis is one of the reported causes. A newly CE-marked flexible endoscopic system, Bariatric Anastomotic Reduction System (BARS) (Ovesco Endoscopy, Tuebingen, Germany), derivative of the well-established endoscopic over-the-scope-clip (OTSC) clipping system, has been recently developed. It was tested in pre-clinical and preliminary clinical use for feasibility and effectiveness in bariatric anastomotic reduction.

MATERIAL AND METHODS

Using a single-channel endoscope with external supplemental working channel, the BARS device captures the two limbs of the anastomosis, reducing its size, thus slowing food passage. After preclinical assessment, six patients with at least a 15% WR and the presence of an enlarged gastrojejunostomy > 20 mm were enrolled. The mean patient age was 49 years (range 24-67). Average interval between gastric bypass and BARS procedure: 8 years (4-13).

RESULTS

All procedures were safely performed without complications. Mean procedure time: 52 min (37 - 75). Preliminary results: mean weight loss 6 kg (4-9) at a 3-month FU.

CONCLUSIONS

BARS could be a promising endoscopic system in case of WR after gastric bypass due to enlargement of the anastomosis.

Efficacy of the OTSC System in the treatment of GI bleeding and wall defects: a PMCF meta-analysis

Since its market launch in 2007, the endoscopic OTSC clipping system has been the object of intensive clinical research. These data were systematically collected for post-market clinical follow-up (PMCF). The aim of the study was the systematic review of the efficacy and safety of the OTSC System. The PMCF database was systematically searched for clinical data on OTSC therapy of GI hemorrhage (H), acute leaks/perforations (AL) and chronic leaks/fistulae (CL). Major outcomes were successful clip application and durable hemostasis/closure of defects. Comprehensive pooled success proportions were established by meta-analytical methods. Four-hundred-fifty-seven publications were reviewed. Fifty-eight articles comprising 1868 patients fulfilled criteria to be included in the analysis. These consisted of retrospective analyses, prospective observational trials, one randomized-controlled trial (STING) and one quasi-controlled study (FLETRock). The pooled proportion analysis revealed high overall proportions of technical success: H - mean 93.0% [95%CI 90.2-95.4], AL-mean 89.7% [95%CI 85.9-92.9] and CL-mean 83.8% [95%CI 76.9-89.7]. Pooled durable clinical success proportions were: H-mean 87.5% [95%CI 80.5-93.2], AL-mean 81.4% [95%CI 77.0-85.3] and CL-mean 63.0% [95%CI 53.0-72.3]. By pooling all clinical data gained, we conclude that OTSC application in GI hemorrhage and closure of GI lesions is safe and effective in real clinical use.

Preclinical evaluation of a novel thermally sensitive co-polymer (LiftUp) for endoscopic resection

Introduction: Endoscopic resection techniques can successfully resect large lesions either in "en bloc" fashion or in "piece-meal" technique by using a submucosal injection solution. The aim of this study was to evaluate the safety of a novel injectable, containing thermally sensitive co-polymer from ethylenoxide and propylenoxide (LiftUp) used as submucosal injection solution.Material and methods: We conducted an in vivo animal trial in the porcine model to evaluate the LiftUp gel in a preclinical setting and to study the effectiveness of mucosal lifting and the safety of the new injectable. In seven animals a total of 63 injections and endoscopic resections were carried out in different anatomical locations (esophagus, stomach and rectum). The resection sites were controlled endoscopically one and four weeks after resection and a histopathological evaluation of the resection sites was performed after four weeks.Results: The application of LiftUp was safe and there were no negative effects on wound healing after injection and resection. A major procedural complication rate (defined as perforation and major haemorrhage) of 3.2% was registered, which undercuts the anticipated mean complication rate of 4-8%. Furthermore, there was no necessity of reinjection after the initial submucosal injection in 90.5% and no procedural complications in 98.8%. The histopathological examination of the tissue samples indicated normal wound healing with granulation tissue and epithelialisation.Conclusion: The use of LiftUp as submucosal injection solution was feasible for different endoscopic resection techniques, with high and long-lasting elevation and fewer procedural adverse events than expected at trial planning. The new injectable is a practical advancement over the current state-of-the-art of submucosal injection and could fasten up the resection procedure and make endoscopic 'en bloc' resection safer.

Efficacy and safety of the remOVE System for OTSC® and FTRD® clip removal: data from a PMCF analysis

INTRODUCTION

The remOVE System (Ovesco Endoscopy AG, Tuebingen, Germany) is a medical device for the endoscopic removal of OTSC or FTRD clips (Ovesco Endoscopy AG, Tuebingen, Germany). The aim of this paper is to assess the efficacy and safety of this system.

MATERIAL AND METHODS

A total of 74 patients underwent clip extraction. The standard removal procedure comprises fragmenting the clip by applying an electrical direct current pulse at two opposing sides of the clip.

RESULTS

Clip fragmentation was successful in 72 of 74 patients (97.3%). In two cases (2.7%) clip fragmentation was not possible. In nine cases (12.2%) a clip fragment could not be removed and was left in place. Complications occurred in three cases (4.1%): two minor bleedings near the clip removal site (2.7%), and one superficial mucosal tear resulting from clip fragment extraction (1.4%).

DISCUSSION

Based on this study, the use of the remOVE System for OTSC or FTRD clip removal can be considered safe and effective.

Volunteer Case Series of a New Telemetric Sensor for Blood Detection in the Upper Gastrointestinal Tract: The HemoPill

BACKGROUND

An acute upper gastrointestinal bleeding event is an emergency situation which requires immediate endoscopic assessment and treatment. A new telemetric real-time intracorporeal bleeding sensor can help in the timely diagnosis of an acute upper gastrointestinal bleeding event: The sensor capsule, HemoPill, is swallowed by the patient if gastrointestinal bleeding is suspected. Information about the bleeding status is displayed by telemetric communication of the capsule with an extracorporeal receiver. This is the first evaluation of the HemoPill to detect blood in the upper human gastrointestinal tract.

METHODS

A voluntary test person ate a defined meal with or without the adjunct of his own blood for a total of eight times and afterward swallowed the sensor capsule. The collected spectrometric receiver data were analyzed to assess whether the sensor system was capable of detecting blood and to evaluate the effect of stomach content as an artifact.

RESULTS

With its optical sensor, the HemoPill was able to reliably indicate the ingested blood in the stomach. The data transmission from the swallowed sensor capsule to the extracorporeal receiver was achieved consistently. The evaluation of diverse concentrations of ingested blood and the respective sensor signals led to an exponential relationship of these variables. This relationship allows to define thresholds for categories indicating the likelihood of blood presence in the gastrointestinal tract.

CONCLUSIONS

The HemoPill is a valuable tool to detect an acute upper gastrointestinal bleeding event without the need of endoscopy.

Porcine survival model to simulate acute upper gastrointestinal bleedings

The existing animal models used for the simulation of acute gastrointestinal bleedings are usually non-survival models. We developed and evaluated a new porcine model (domestic pig, German Landrace) in which the animal remains alive and survives the artificial bleeding without any cardiovascular impairment. This consists of a bleeding catheter which is implanted into the stomach, then subcutaneously tunnelled from the abdomen to the neck where it is exteriorized and fixed with sutures. Using the injection of porcine blood, controllable and reproducible acute upper gastrointestinal bleeding can be simulated while maintaining normal gastrointestinal motility and physiology. Depending on the volume of blood applied through the gastric catheter, the bleeding intensity can be varied from traces of blood to a massive haemorrhage. This porcine model could be valuable, e.g. for testing the efficacy of new bleeding diagnostics in large animals before human use.

Endoscopic full-thickness resection and clip defect closure in the colon with the new FTRD system: experimental study

BACKGROUND

The benefit of endoscopic full-thickness resection is the improved diagnostic work-up with an integral wall specimen which allows a precise determination of the tumor or its precursor and its infiltration depth into the wall.

MATERIALS AND METHODS

A new endoscopic full-thickness resection device (FTRD), which is a combination of a modified over-the-scope-clip (OTSC) system with an electrocautery snare, has been tested in an experimental setting. In eleven pigs, divided into three groups, endoscopic full-thickness resection was performed in the colon at one or two sites, respectively. Seven days (n = 7) or 28 days (n = 4) after the intervention, the animals were euthanized following endoscopic examination of the resection and clip application sites. Furthermore, two different clips were tested during these animal trials in order to evaluate the most effective clip design.

RESULTS

The average diameter of the tissue resected with the FTRD was 3.1, 3.6, and 5.4 cm in the three groups. On follow-up endoscopy 7 days after the intervention, fibrin coating and stool residues were found at all clips, causing minor inflammatory reactions. However, the colon wall under the clip was non-inflamed. After 28 days, the serosa had primarily healed in all cases. There were also stool residues at all clips; however, no acute inflammatory reactions were seen anymore, due to complete healing. Histological assessment did not show any signs of dehiscence in the region of the scar, or ischemia in the clip area. In addition, no wound infections, such as abscess formation, were observed.

CONCLUSIONS

This study demonstrates the safety and efficacy of the clip-and-cut technique using the new FTRD system. With the device, a local full-thickness colon resection can be easily created, and the resulting wall defect is reliably sealed by the endoluminal application of a modified OTSC clip.

Annulated and bridged tetrahydrofurans from alkenoxyl radical cyclization

4-Pentenoxyl radicals sharing two or more carbon atoms with a cycloalkane cyclize in a predictable manner stereoselectively and regioselectively to afford in solutions of bromotrichloromethane cycloalkyl-fused or -bridged 2-bromomethyltetrahydrofurans in up to 95% yield. Stereoselectivity in alkenoxyl radical ring closures arises from cumulative steric effects. The substituent positioned the closest to the alkene carbon, which is being attacked by the oxygen radical, exerts the strongest stereodirecting effect. This principal inductor guides 5-exo-cyclization 2,3-trans- or 2,4-cis-selectively. The substituent located further from the attacked π-bond is the secondary inductor. A secondary inductor in the relative trans-configuration enhances stereodifferentiation by the primary inductor; a cis-configured secondary inductor decreases this effect. A secondary inductor is not able to overrule the guiding effect of a similar sized primary inductor. Intramolecular 4-pentenoxyl radical additions to a cyclohexene-bound exo-methylene group or to endocyclic double bonds proceed cis-specifically, as exemplified by synthesis of a diastereomerically pure bromobicyclo[2.2.1]heptyl-annulated tetrahydrofuran from the verbenylethyloxyl radical. According to theory, the experimental 2,3-cis-specificity in alkoxyl radical cyclization to an endocyclic π-bond arises from strain associated with the 2,3-trans-ring closure.

Performance of the OTSC System in the endoscopic closure of iatrogenic gastrointestinal perforations: a systematic review

BACKGROUND

Reliable closure is a prerequisite for conventional and innovative endoscopic procedures, such as NOTES. The purpose of this study is the systematic evaluation of the procedural and clinical success rates in closure of iatrogenic gastrointestinal perforations and acute anastomotic leaks by means of the over-the-scope-clip system (OTSC(®)).

DESIGN

PubMed and other sources were searched systematically for clinical and preclinical research on the evaluation of the OTSC System for closure of gastrointestinal perforations and leaks. Appraisal of studies for inclusion and data extraction was performed independently by two reviewers using an a priori determined data extraction grid. Major endpoints to be extracted were data on procedural success (successful clip application) and clinical access (durable closure of defect without secondary adjunct therapy).

RESULTS

A total of 17 clinical research articles/abstracts and 22 preclinical research articles/abstracts were identified. The examined clinical studies comprised case series and clinical single-arm studies. The reviewed studies revealed a consistently high mean rate of procedural success of 80-100 % and durable clinical success of 57-100 %. An identified major drawback preventing successful clip application was occurrence of fibrotic or inflamed lesion edges. Usage of the OTSC System was accompanied by neither major clip-related nor application-related complication. In experimental settings, closure of larger perforations and gastric access sites of NOTES or endoscopic full-thickness resection were achieved with high rates of success.

CONCLUSIONS

Because randomized, clinical trials are not available in this field of indication, the evaluation is based on small case series. Nevertheless, by pooling all experience gained, we conclude that endoscopic closure of iatrogenic gastrointestinal perforations and acute anastomotic leaks by means of the OTSC System is a safe and effective method.

The anal fistula claw: the OTSC clip for anal fistula closure

AIM

Surgical closure of high or complex anal fistulae is often a difficult challenge. A special Nitinol clip, the OTSC clip (Ovesco AG), was evaluated for fistula closure in a porcine model.

METHOD

A total of 20 fistulae were created in 10 animals by seton insertion. Four weeks after fistula induction the setons were removed: one internal fistula opening per animal was left untreated as control whereas the other opening was closed by the OTSC clip using a specially developed transanal clip applicator. The safety and technical feasibility of the clip application were tested. Another 4 weeks later, fistulae were macroscopically assessed for closure. For histological examination, the anorectum including the fistula tract was excised en bloc.

RESULTS

Four weeks after clip placement, all external and internal fistula openings were macroscopically closed. The clip application site presented with an increased scarring. Microscopically, 40% of residual tracts and a more intense chronic inflammation were seen in the untreated control fistulae. After clip placement, 10% of the fistulae persisted associated with a higher density of collagen fibres indicating a better fistula scarring and healing. No unexpected side-effects or complications caused by the clip were observed.

CONCLUSION

Fistula closure using the OTSC clip represents a promising sphincter-preserving minimally invasive procedure. This study demonstrated the safety and feasibility of the 'anal fistula claw' for fistula closure. In spite of limitations of the porcine model the results justify clinical applications and further investigations.

Performance of the OTSC System in the endoscopic closure of gastrointestinal fistulae--a meta-analysis

BACKGROUND

Conventional endoscopic treatment options for closure of gastrointestinal fistulae are impaired by several limitations and therefore yield high rates of recurrence. Aim of the study is the evaluation of the primary-technical and secondary-clinical success rates in closure of gastrointestinal fistulae by means of the OTSC System.

DESIGN/METHODS

The database Medline was systematically searched for primary research on the evaluation of the OTSC System in closure of gastrointestinal fistulae. Appraisal of studies for inclusion and data extraction were performed independently by two reviewers using an a priori determined data extraction grid.

RESULTS

A total of 19 primary research articles were identified. The examined studies comprised case reports as well as case series and clinical single-arm studies (n = 7) with a limited number of participants. Reviewed studies revealed a high rate of procedural success (mean 84.6%; 95% confidence interval 66.6 to 93.8%) and durable clinical success (mean 69.0%; 95% confidence interval 51.8 to 82.2%). Failed attempts and incomplete closures were mainly ascribed to the challenging effort of treating highly fibrotic chronic fistulae.

CONCLUSION

Endoscopic closure of gastrointestinal fistulae by means of the OTSC System is a safe and effective method.

Laser ion source development at Holifield Radioactive Ion Beam Facility

This report describes the efforts made to develop a resonant-ionization laser ion source based on tunable Ti:sapphire lasers for nuclear physics and astrophysics research at Holifield Radioactive Ion Beam Facility. Three Ti:sapphire lasers have been upgraded with individual pump lasers to eliminate laser power losses due to synchronization delays. Ionization schemes for 14 elements have been obtained. Off-line studies show that the overall efficiency of the laser ion source can be as high as 40%. TaC surface coatings have been investigated for minimizing surface and bulk trapping of the atoms of interest.

Beam purification by photodetachment (invited)

Ion beam purity is of crucial importance to many basic and applied studies in nuclear science. Selective photodetachment has been proposed to suppress unwanted species in negative ion beams while preserving the intensity of the species of interest. A highly efficient technique based on photodetachment in a gas-filled radio frequency quadrupole ion cooler has been demonstrated. In off-line experiments with stable ions, up to 10(4) times suppression of the isobar contaminants in a number of interesting radioactive negative ion beams has been demonstrated. For selected species, this technique promises new experimental possibilities in studies on exotic nuclei, accelerator mass spectrometry, and fundamental properties of negative atomic and molecular ions.

Endoluminal full-thickness resection of GI lesions: a new device and technique

Full-thickness resection techniques are of growing interest in the field of endoscopic removal of tumors or their precursors in the digestive tract. A new dedicated full-thickness resection device has been developed based on the combination of the OTSC clip, an enlarged resection cap and an integrated snare. The device prototype allows combined resection of all gastrointestinal organ wall layers in one maneuver, up to a size of 3 x 3 cm. The device has been pre-clinically tested to demonstrate feasibility of full-thickness resection in the colon. Two clinical cases have been performed successfully to date.

GISELE: a resonant ionization laser ion source for the production of radioactive ions at GANIL

SPIRAL2 is the new project under construction at GANIL to produce radioactive ion beams and in particular neutron rich ion beams. For the past 10 yr SPIRAL1 at GANIL has been delivering accelerated radioactive ion beams of gases. Both facilities now need to extend the range of radioactive ion beams produced to condensable elements. For that purpose, a resonant ionization laser ion source, funded by the French Research National Agency, is under development at GANIL, in collaboration with IPN Orsay, University of Mainz (Germany) and TRIUMF, Vancouver (Canada). A description of this project called GISELE (GANIL Ion Source using Electron Laser Excitation) is presented.

Ion production from solid state laser ion sources

Laser ion sources based on resonant excitation and ionization of atoms are well-established tools for selective and efficient production of radioactive ion beams. Recent developments are focused on the use of the state-of-the-art all solid-state laser systems. To date, 35 elements of the periodic table are available from laser ion sources based on tunable Ti:sapphire lasers. Recent progress in this field regarding the establishment of suitable optical excitation schemes for Ti:sapphire lasers are reported.

Time profile of ion pulses produced in a hot-cavity laser ion source

The time spreads of Mn ions produced by three-photon resonant ionization in a hot-cavity laser ion source are measured. A one-dimensional ion-transport model is developed to simulate the observed ion time structures. Assuming ions are generated with a Maxwellian velocity distribution and are guided by an axial electric field, the predictions of the model agree reasonably well with the experimental data and suggest that the ions are radially confined in the ion source and a substantial fraction of the ions in the transport tube are extracted.

The laser ion source trap for highest isobaric selectivity in online exotic isotope production

The improvement in the performance of a conventional laser ion source in the laser ion source and trap (LIST) project is presented, which envisages installation of a repeller electrode and a linear Paul trap/ion guide structure. This approach promises highest isobaric purity and optimum temporal and spatial control of the radioactive ion beam produced at an online isotope separator facility. The functionality of the LIST was explored at the offline test separators of University of Mainz (UMz) and ISOLDE/CERN, using the UMz solid state laser system. Ionization efficiency and selectivity as well as time structure and transversal emittance of the produced ion beam was determined. Next step after complete characterization is the construction and installation of the radiation-hard final trap structure and its first online application.

Emittance characterization of a hot-cavity laser ion source at Holifield Radioactive Ion Beam Facility

The first investigation of the transverse emittance of a hot-cavity laser ion source based on all-solid-state Ti:sapphire lasers is presented. The emittances of (63)Cu ion beams generated by three-photon resonant ionization are measured and compared with that of the (69)Ga and (39)K ion beams resulting from surface ionization in the same ion source. A self-consistent unbiased elliptical exclusion method is adapted for noise reduction and emittance analysis. Typical values of the rms and 90% fractional emittances of the Cu ion beams at 20 keV energy are found to be about 2 and 8 pi mm mrad, respectively, for the ion currents of 2-40 nA investigated. The emittances of the laser-produced Cu ion beams are smaller than those of the surface-ionized Ga and K ion beams.

Effective relief of malignant ascites in patients with advanced ovarian cancer by a trifunctional anti-EpCAM x anti-CD3 antibody: a phase I/II study

PURPOSE

Malignant ascites in ovarian carcinoma patients is associated with poor prognosis and reduced quality of life. The trifunctional antibody catumaxomab (anti-EpCAM x anti-CD3) enhances the antitumor activity by redirecting T cells and Fcgamma receptor I/III--positive accessory cells to the tumor. This multicenter phase I/II dose-escalating study investigated tolerability and efficacy of i.p. catumaxomab application in ovarian cancer patients with malignant ascites containing epithelial cell adhesion molecule (EpCAM)--positive tumor cells.

EXPERIMENTAL DESIGN

Twenty-three women with recurrent ascites due to pretreated refractory ovarian cancer were treated with four to five i.p. infusions of catumaxomab in doses of 5 to 200 microg within 9 to 13 days.

RESULTS

The maximum tolerated dose was defined at 10, 20, 50, 200, and 200 microg for the first through fifth doses. Side effects included transient fever (83%), nausea (61%), and vomiting (57%), mostly CTCAE (Common Terminology Criteria for Adverse Events) grade 1 or 2. A total of 39 grade 3 and 2 grade 4 treatment-related adverse events (AE), 9 of them after the highest dose level (200 microg), were observed in 16 patients. Most AEs were reversible without sequelae. Treatment with catumaxomab resulted in significant and sustained reduction of ascites flow rate. A total of 22/23 patients did not require paracentesis between the last infusion and the end of study at day 37. Tumor cell monitoring revealed a reduction of EpCAM-positive malignant cells in ascites by up to 5 log.

CONCLUSION

I.p. immunotherapy with catumaxomab prevented the accumulation of ascites and efficiently eliminated tumor cells with an acceptable safety profile. This suggests that catumaxomab is a promising treatment option in ovarian cancer patients with malignant ascites.

Microwave-assisted generation of alkoxyl radicals and their use in additions, β-fragmentations, and remote functionalizations

Microwave irradiation (2.45 GHz, 300-500 W) of N-(alkoxy)thiazole-2(3H)-thiones in low-absorbing solvents affords alkoxyl radicals, which were identified by (i) spin adduct formation (EPR-spectroscopy) and (ii) fingerprint-type selectivities in intramolecular additions (stereoselective synthesis of disubstituted tetrahydrofurans), beta-fragmentations (formation of carbonyl compounds), and C,H-activation of aliphatic subunits, by delta-selective hydrogen atom transfer. C-Radicals formed from oxygen-centered intermediates were trapped either by Bu(3)SnH, L-cysteine ethyl ester, the reduced form of glutathione (reductive trapping), or by bromine atom donor BrCCl(3) (heteroatom functionalization) The results suggest that microwave activation is superior to UV/Vis-photolysis and conductive heating for alkoxyl radical generation from N-(alkoxy)thiazolethiones. It offers by far the shortest reaction times along with the option to reduce the amount of trapping reagent significantly.

Human monocyte-derived neohepatocytes: a promising alternative to primary human hepatocytes for autologous cell therapy

BACKGROUND

There is growing interest in new therapeutic options for the treatment of end-stage liver diseases. In addition to mechanical devices supporting liver function, such as bioreactors, the transplantation of hepatocyte-like cells derived from (adult) stem cells offer great perspectives. We have generated hepatocyte-like (NeoHep) cells from terminally differentiated peripheral blood monocytes and, in this study, have evaluated these cells as a possible tool for autologous cell therapy.

METHODS

Peripheral blood monocytes were cultured under conditions that promote hepatocyte-like differentiation and were characterized for hepatocyte marker expression by reverse-transcriptase polymerase chain reaction, immunohistochemistry, and immunoblotting and for specific secretory and metabolic functions with the appropriate biochemical assays.

RESULTS

NeoHep cells resembled primary human hepatocytes with respect to morphology, expression of hepatocyte markers (albumin, cytochrome P450 isoenzymes, asialoglycoprotein receptor, coagulation factor VII), various secretory and metabolic functions (albumin secretion, urea production, lactate formation, and lactate dehydrogenase and aspartate transaminase release), and drug detoxification activities (phase I metabolization of ethoxycoumarin into 7OH-coumarin after stimulation with 3-methylcholanthren, induction of CYP3A4 activity, and phase II metabolization through UDP-glucuronidation of 4-methyl-umbelliferone).

CONCLUSIONS

These data convincingly show that NeoHep cells display a phenotype and specific in vitro metabolic functions that are quantitatively and qualitatively comparable in part with those of primary human hepatocytes. These cells could thus be clinically applied in an autologous setting for the treatment of end-stage liver diseases or for improving liver function in patients who have undergone critical liver-mass resection.

Sphincter-saving treatment in epidermoid anal cancer: cooperative analysis of 142 patients in five German university surgical centers

Five southern German university centers cooperated in comparing the effect of surgical vs. nonsurgical therapy strategies on survival and sphincter preservation in the treatment of anal cancer. A standardized questionnaire was used to evaluate retrospectively (mean follow-up 30 months) treatment strategy and outcome (survival, colostomy rate, colostomy-free survival) in patients treated between 1987 and 1996. Of the 142 patients 65% had squamous cell, 20% basaloid, 6% adeno-, and 1% undifferentiated carcinoma (8% histology not recorded); 9% were classified in UICC stage I, 37% in stage II, 25% in stage III, and 4% in stage IV (25% not recorded). Primary treatment consisted of local excision (10%), excision plus radio- and/or chemotherapy (17%), radiotherapy (20%), radiochemotherapy (28%), or colostomy with or without resection, radiotherapy, and chemotherapy (23%). We observed no difference between these treatment groups in overall (P = 0.43) or colostomy-free survival (P = 0.14, log-rank). Primary colostomy was prevented in 77% of cases and decreased over the years. Mean overall survival (in months) was 42 in stage I, 38 in stage II, and 25 in stage III (P = 0.0013); mean colostomy-free survival was 36 in stage I, 26 in stage II, and 16 in stage III (P = 0.0021, log-rank). Outcome was not significantly related to therapeutic strategy (surgery or radio-chemotherapy. Primary surgical and nonsurgical strategies in treating anal cancer thus produced similar results, although radiochemotherapy is usually recommended for sphincter-endangering anal cancer. Challenges to be met in the future include the prevention of metastasis and long-term preservation of anal sphincter function.

[Yamakawa prosthesis with prolonged placement as a therapy concept exemplified by benign biliary stricture]

AIM

As an alternative method to the operative revision of benign bile duct strictures, we report the use of a large-bore bile duct prosthesis (Yamakawa prosthesis) in one patient.

METHODS

Bilateral percutaneous transhepatic implantation of Yamakawa prostheses (14 F right side, 12 F left side) was performed without adjunctive balloon dilatation. The prostheses were exchanged every 8 weeks under continuous antibiotic treatment and were finally removed after 8 months.

RESULTS

Control cholangiography showed a normal intrahepatic biliary system on the right side and a 50% stenosis at the orifice of the left hepatic duct. Follow-up over 18 months showed no signs of recurrent disease.

CONCLUSIONS

In comparison to balloon dilatation and implantation of metallic stents, prolonged bilateral splinting with large-bore Yamakawa prostheses seems to be an alternative for the treatment of benign bile duct strictures.

Diagnosis and management of metastatic gastrinoma by multimodality treatment including liver transplantation: report of a case

Neuroendocrine tumors of the pancreas are being recognized with increasing frequency, not because the incidence has increased, but as a result of improvements in diagnostic tools such as radioimmunoassays for a variety of circulating peptides, and imaging methods that include positron emission tomography (PET) and immunoscintigraphy. Nevertheless, establishing the diagnosis of a neuroendocrine tumor is always a challenge to the clinician from both diagnostic and therapeutic perspectives. Liver transplantation as the ultimate therapeutic, or at least palliative, option for hepatic metastases has produced contradictory results over the past decade. We report herein the case of a 23-year-old woman who, after being diagnosed with gastrinoma in 1989, underwent the complete therapeutic array including liver transplantation for hepatic metastases in 1991. Although an extrahepatic tumor recurred 2 years later, for which double chemotherapy with 5-FU and streptozotocin was given, she is currently leading a normal life with a full-time job. This case prompted a critical review of the current literature on diagnosis and medical and surgical treatment.

The mast cell-nerve axis in wound healing: a hypothesis

Beyond their classic roles in allergic reactions and defence against parasites, mast cells can now be viewed as key players in regulating connective tissue homeostasis. There is good evidence that mast cells are in close morphological and functional contact with the peripheral nervous system. Although substantial differences exist between mast cells of different tissues and different species, they produce a wide range of agents, including cytokines, growth factors, and other regulatory molecules, and they respond to an equally wide range of substances, including neuropeptides. At our current level of understanding wound healing, inflammation plays a central role in this process, with macrophages being central protagonists at the cellular level. There is now increasing evidence that mast cells are also involved in wound healing, in health and disease. They produce and secrete histamine, heparin, and multifunctional cytokines and growth factors, which represent important agents in the wound-healing process. Reviewing the recent literature supporting this hypothesis, we also outline the clinical importance of this work to help close the gap between basic research and clinical application.

Effect of truncal vagotomy and capsaicin on mast cells and IgA-positive plasma cells in rat jejunal mucosa

Immunocompetent cells, including mast cells and plasma cells (PC), in the intestinal mucosa are closely apposed to nerve fibres. Recent work has shown that vagal afferent nerves penetrate the jejunal mucosa and contact intestinal mucosal mast cells (IMMC); and that electrical stimulation of the vagus results in increased IMMC histamine content. To determine if the vagus nerve exerts a trophic effect on immunocompetent cells in the gut mucosa, the effects of truncal vagotomy and neonatal capsaicin treatment on IMMC and IgA containing PC in the lamina propria of rat jejunum were investigated. Three weeks after vagotomy, microdensitometric assessment of Alcian blue stained sections revealed 25% fewer IMMC in vagotomized animals than in controls (P < 0.05). Three months after neonatal capsaicin administration 28% fewer IMMC were found in treated rat jejunum, compared with littermate controls (P < 0.05). Three weeks post-surgery, IgA-PC densities were increased in both vagotomized animals (that also underwent pyloroplasty) and pyloroplasty controls, compared to animals subjected to laparotomy only. The proportion of lamina propria areas remained stable, indicating that the observations reflected real reductions in the numbers of IMMC. We also determined the densities of B-50 (a nerve growth-associated protein, also called GAP-43) immunoreactive nerve fibres in the lamina propria, as well as nerve profile areas, three weeks after vagotomy, and these parameters were unchanged. Taken together, these findings support the hypothesis that the vagus exerts a trophic effect on IMMC; and that capsaicin-sensitive nerves also affect the IMMC population. These data add to the growing body of evidence for a functional connection between IMMC and the nervous system.

[Sex differences in neuromodulation of mucosal mast cells in the rat jejunum]

The effect of electrical stimulation of both cervical vagal nerves on mucosal mast cells in the jejunum was investigated in an in vivo animal model with rats of both sexes. Males showed a significant increase of mast cell densities after electrical stimulation (1.0 mA, 5 Hz, 5 ms, 12 min) in the lamina propria. Simultaneously, we observed a significant increase of tissue histamine levels (ANOVA: P < 0.05), whereas serum levels remained unchanged. However, even though females had significantly higher levels throughout compared to males (ANOVA: P < 0.05), they did not show any significant reaction to electrical stimulation. These in vivo data support morphological and in vitro data from other investigators, who hypothesized a functional interaction between mucosal mast cells and nerves. However, degranulation seems to be a poor in situ indicator for mast-cell stimulation, as mast-cell densities increased in males, while the percentage of degranulated cells remained the same in all groups (about 40%). Instead, electrical stimulation of the vagal nerve seems to trigger histamine synthesis, or simply stabilization of mast cells. Interestingly, this phenomenon seems to be sex-dependent, suggesting a regulatory role for sex hormones in this scenario.

Brief clinical report: glutamine-enriched total parenteral nutrition in a patient with radiation-induced renal and intestinal fibrosis

This brief clinical report illustrates the case of a 50-y-old male patient with severe radiation-induced renal and intestinal fibrosis who received glutamine-enriched total parenteral nutrition (TPN). The patient had end-stage renal disease and, therefore, underwent a kidney transplant. In the postoperative course the patient developed signs of bowel obstruction and cachexia. He received two courses of glutamine-enriched TPN before he underwent surgery for small bowel stenosis. Postoperatively, the patient received a third course of glutamine-enriched TPN. During the patient's hospital course the following indexes were monitored: patient's weight, serum concentrations of protein, albumin, and trialglycerol. Intestinal permeability was assessed with the lactulose-mannitol sugar test (L-M test). We measured changes in the patient's weight and the L-M test. We hypothesize that glutamine-enriched TPN may have been beneficial in the hospital course of this critically ill patient and may have influenced the patient's intestinal function and permeability.

Fibre is an essential ingredient of enteral diets to limit bacterial translocation in rats

OBJECTIVE

To assess the effect of six different enteral diets on the gut barrier.

DESIGN

Laboratory study.

SETTING

University hospital, Germany.

MATERIAL

70 Specific pathogen free female Crl:CDR BR rats.

INTERVENTIONS

For 7 days, 6 groups of rats were fed orally with standard chow (n = 15); total parenteral nutrition solution (oral TPN, n = 15); elemental diet (ED, n = 10); nutrient-defined diet (NDD, n = 10); or the NDD supplemented with uracil (NDD+uracil, n = 10), or fibre (NDD+fibre, n = 10).

MAIN OUTCOME MEASURES

Bacterial translocation to mesenteric lymph nodes, numbers of Gram negative enterobacteria and total aerobic bacteria in the caecum, and intestinal concentrations of secretory IgA.

RESULTS

The incidence of bacterial translocation was significantly increased in the groups given oral TPN, ED, NDD, and NDD+uracil compared with the group given chow. Only NDD+fibre resulted in a similar degree of translocation to that in the chow group. All groups in which there was increased translocation had a highly significant overgrowth of aerobic bacteria in the caecum, mainly by Gram negative enteric organisms. The secretory IgA concentration was reduced in the group that had been given oral TPN, and that in the ED and NDD+uracil groups was similar to that in the chow group. NDD and NDD+fibre were associated with higher intestinal concentrations of secretory IgA than chow.

CONCLUSION

Fibre-free enteral diets do not protect the gut antimicrobial barrier whatever else is in them. The superiority of early enteral as opposed to parenteral nutrition after injury may, therefore, not be the result of a specific protective effect on the gut barrier. The supplementation of commercial enteral diets with bulk fibre should be tested in clinical trials.