Association of systemic antibody response against polyethylene terephthalate with inflammatory serum cytokine profile following implantation of differently coated vascular prostheses in a rat animal model

Experimental studies demonstrated antibodies against matrix and coating of polyester-based vascular prostheses. Thus, this study examined associations of these antibodies with serum cytokines (IL-2, IL-4, and IL-10) and local inflammatory reactions. Rats (n = 8/group) intramuscularly received prosthesis segments [PET-C, PET-G, and PET-A groups: polyethylene terephthalate (PET)-based prostheses coated with bovine collagen and gelatin or human serum albumin, respectively; uncoated polytetrafluoroethylene-based (PTFE) prosthesis], with sham-operated controls. Blood was drawn pre-operatively and weekly until day 22. Polymer-specific or coating-specific antibodies and cytokines were detected by enzyme immunoassays, inflammatory reactions were immunohistochemically evaluated on day 23. Polymer-specific antibodies were detected in all PET-groups using uncoated PET as antigenic target, but not for PTFE or controls, coating-specific antibodies only for PET-A. IL-10 was increased in all PET-groups and correlated with polymer-specific antibodies for PET-G and PET-A. IL-2 was increased for PET-A, but overall correlated with PET-specific antibodies. IL-4 remained unchanged in all groups. Intense local inflammatory reactions (ED1⁺ /ED2⁺ macrophages and T lymphocytes) were found within all PET-groups, but only minor for PTFE or controls. In conclusion, PET-specific antibodies were associated with increased IL-10 and along with concurrent coating-specific antibodies also with increased IL-2, indicating a specific T cell response. Thus, matrix and/or coating of polymeric vascular prostheses elicit distinct systemic immune reactions, probably influencing local inflammatory reactions.

OP0196-PARE #ARTHRITISATWORK: USING TWITTER TO ENGAGE THE INTERNATIONAL ARTHRITIS COMMUNITY

Background:

In 2019, EULAR launched the #Time2Work campaign [1] to raise awareness of the impact of rheumatic and musculoskeletal diseases on individuals, society, and the economy. Building on this theme, the Canadian Arthritis Patient Alliance (CAPA) developed a social media campaign and Twitter chat in collaboration with international patient advocates and organizations. The Twitter chat built upon CAPA’s successful development of workplace resources for people living with arthritis [2].

Objectives:

To deliver an international #ArthritisAtWork social media campaign on Twitter, in support of the #Time2Work campaign.

Methods:

A one-hour Twitter Chat was held on World Arthritis Day (October 12, 2019) on arthritis in the workplace (#ArthritisAtWork) from 18:00 to 19:00 UTC. The chat was hosted by CAPA and co-hosted by Simon Stones, a patient advocate from the United Kingdom (UK) and CreakyJoints, patient-driven arthritis organization in the United States (US). The Twitter Chat questions were co-developed in advance by the hosts, and blog posts were shared from CAPA’s website. Each host also promoted the Twitter Chat through their websites, newsletters and online communities. A social media analytical tool, Symplur, was used to measure audience engagement using the hashtag #ArthritisAtWork. In addition, pertinent Tweets before, during, and after the chat were obtained. The analysis of themes was undertaken to identify common issues and questions.

Results:

One hundred and ten users participated in the Twitter chat between 17:20 and 19:20 UTC. Participants included people living with arthritis, researchers, patient organizations, health information outlets and academic institutions. During this period, 565 tweets were shared between participants in Australia, Canada, Ireland, Spain, UK and US. There were 3.352 million Twitter impressions. This represents the number of times a tweet appears to users in either their timeline or search results. Emergent themes of the analysis include:

Conclusion:

The social media campaign was successful in reaching a diverse audience and supporting the #Time2Work campaign. Social media tools can provide an important social support for people living with arthritis as they navigate workplace challenges. It also offers a more contemporary platform to engage the international community on issues of common interest. Working together, internationally helps expand reach and reduce barriers in communication. Research can be conducted to measure potential behavior change that leverages digital social support for people living with arthritis.

References:

[1]EULAR (2019). Press release “EULAR launches Time2Work campaign to highlight the importance of keeping people with rheumatic and musculoskeletal diseases in work. Available from:https://www.eular.org/sysModules/obxContent/files/www.eular.2015/1_42291DEB-50E5-49AE-5726D0FAAA83A7D4/time2work_campaign_press_release_final.pdf2. CAPA (2019). Arthritis in the Workplace: Resources for Patients by Patients. Available from:http://arthritispatient.ca/arthritis-in-the-workplace-resources-for-patients-by-patients/

Disclosure of Interests:

Laurie Proulx Grant/research support from: Sources of grants and support received by the Canadian Arthritis Patient Alliance (including in-kind support) in the last two years include: AbbVie Canada, Alliance for Safe Biologic Medicines, Amgen Canada, Arthritis Alliance of Canada, The Arthritis Society, Best Medicines Coalition, CADTH, Canadian Rheumatology Association, Eli Lilly Canada, European League Against Rheumatism, Janssen Canada, Manulife, Novartis Canada, Ontario Rheumatology Association, Pfizer Canada (including Pfizer Hospira), Purdue Pharma Canada, Sanofi, and UCB Pharma., Speakers bureau: I have provided speaking services to Sanofi and Eli Lilly. These engagements do not relate to this abstract., Simon Stones Consultant of: I have been a paid consultant for Envision Pharma Group and Parexel. This does not relate to this abstract., Speakers bureau: I have been a paid speaker for Actelion and Janssen. These do not relate to this abstract., Joseph Coe: None declared, Dawn Richards Grant/research support from: Sources of grants and support received by the Canadian Arthritis Patient Alliance (including in-kind support) in the last two years include: AbbVie Canada, Alliance for Safe Biologic Medicines, Amgen Canada, Arthritis Alliance of Canada, The Arthritis Society, Best Medicines Coalition, CADTH, Canadian Rheumatology Association, Eli Lilly Canada, European League Against Rheumatism, Janssen Canada, Manulife, Novartis Canada, Ontario Rheumatology Association, Pfizer Canada (including Pfizer Hospira), Purdue Pharma Canada, Sanofi, and UCB Pharma., Consultant of: Dawn has done small consulting projects on patient engagement for companies., Speakers bureau: Dawn has been a paid speaker for several companies., Linda Wilhelm Grant/research support from: Sources of grants and support received by the Canadian Arthritis Patient Alliance (including in-kind support) in the last two years include: AbbVie Canada, Alliance for Safe Biologic Medicines, Amgen Canada, Arthritis Alliance of Canada, The Arthritis Society, Best Medicines Coalition, CADTH, Canadian Rheumatology Association, Eli Lilly Canada, European League Against Rheumatism, Janssen Canada, Manulife, Novartis Canada, Ontario Rheumatology Association, Pfizer Canada (including Pfizer Hospira), Purdue Pharma Canada, Sanofi, and UCB Pharma., Nathalie Robertson Grant/research support from: Sources of grants and support received by the Canadian Arthritis Patient Alliance (including in-kind support) in the last two years include: AbbVie Canada, Alliance for Safe Biologic Medicines, Amgen Canada, Arthritis Alliance of Canada, The Arthritis Society, Best Medicines Coalition, CADTH, Canadian Rheumatology Association, Eli Lilly Canada, European League Against Rheumatism, Janssen Canada, Manulife, Novartis Canada, Ontario Rheumatology Association, Pfizer Canada (including Pfizer Hospira), Purdue Pharma Canada, Sanofi, and UCB Pharma., Janet Gunderson Grant/research support from: Sources of grants and support received by the Canadian Arthritis Patient Alliance (including in-kind support) in the last two years include: AbbVie Canada, Alliance for Safe Biologic Medicines, Amgen Canada, Arthritis Alliance of Canada, The Arthritis Society, Best Medicines Coalition, CADTH, Canadian Rheumatology Association, Eli Lilly Canada, European League Against Rheumatism, Janssen Canada, Manulife, Novartis Canada, Ontario Rheumatology Association, Pfizer Canada (including Pfizer Hospira), Purdue Pharma Canada, Sanofi, and UCB Pharma., Alexandra Sirois Grant/research support from: Sources of grants and support received by the Canadian Arthritis Patient Alliance (including in-kind support) in the last two years include: AbbVie Canada, Alliance for Safe Biologic Medicines, Amgen Canada, Arthritis Alliance of Canada, The Arthritis Society, Best Medicines Coalition, CADTH, Canadian Rheumatology Association, Eli Lilly Canada, European League Against Rheumatism, Janssen Canada, Manulife, Novartis Canada, Ontario Rheumatology Association, Pfizer Canada (including Pfizer Hospira), Purdue Pharma Canada, Sanofi, and UCB Pharma., Annette McKinnon Grant/research support from: Sources of grants and support received by the Canadian Arthritis Patient Alliance (including in-kind support) in the last two years include: AbbVie Canada, Alliance for Safe Biologic Medicines, Amgen Canada, Arthritis Alliance of Canada, The Arthritis Society, Best Medicines Coalition, CADTH, Canadian Rheumatology Association, Eli Lilly Canada, European League Against Rheumatism, Janssen Canada, Manulife, Novartis Canada, Ontario Rheumatology Association, Pfizer Canada (including Pfizer Hospira), Purdue Pharma Canada, Sanofi, and UCB Pharma.

Occurence of microplastics in the hyporheic zone of rivers

Although recent studies indicate that fluvial systems can be accumulation areas for microplastics (MPs), the common perception still treats rivers and streams primarily as pure transport vectors for MPs. In this study we investigate the occurrence of MPs in a yet unnoticed but essential compartment of fluvial ecosystems - the hyporheic zone (HZ). Larger MP particles (500–5,000 µm) were detected using attenuated total reflectance (ATR) - Fourier-transform infrared (FTIR) spectroscopy. Our analysis of MPs (500–5,000 µm) in five freeze cores extracted for the Roter Main River sediments (Germany) showed that MPs were detectable down to a depth of 0.6 m below the streambed in low abundances (≪1 particle per kg dry weight). Additionally, one core was analyzed as an example for smaller MPs (20–500 µm) with focal plane array (FPA)- based µFTIR spectroscopy. Highest MP abundances (~30,000 particles per kg dry weight) were measured for pore scale particles (20–50 µm). The detected high abundances indicate that the HZ can be a significant accumulation area for pore scale MPs (20–50 µm), a size fraction that yet is not considered in literature. As the HZ is known as an important habitat for invertebrates representing the base of riverine food webs, aquatic food webs can potentially be threatened by the presence of MPs in the HZ. Hyporheic exchange is discussed as a potential mechanism leading to a transfer of pore scale MPs from surface flow into streambed sediments and as a potential vector for small MPs to enter the local aquifer. MPs in the HZ therefore may be a potential risk for drinking water supplies, particularly during drinking water production via river bank filtration.

Corrigendum to 'In vivo evaluation of copper release and acute local tissue reactions after implantation of copper-coated titanium implants in rats'

In the "Materials and methods" chapter of the article given above, in section 2.1 titled "Implant samples and preparation" on page 2 (top paragraph of the right column), an incorrect value of 1 μg mm-2 for the average Cu load of the surface was inadvertently specified. This was due to an accidental mix-up of electronic data sets from examination of different implant series. The correct value is 0.2 μg mm-2. No other data given in the article are affected. The authors kindly apologize for this mistake.

In vivo evaluation of copper release and acute local tissue reactions after implantation of copper-coated titanium implants in rats

Copper (Cu) based coatings can reduce infections for titanium (Ti) implants. However, Cu is also cytotoxic. To examine the balance of antibacterial versus adverse tissue effects, this study aimed at evaluating a Cu coating regarding in vivo Cu release and local inflammatory reactions for 72 h. TiAl6V4 plates received either plasma electrolytic oxidation only (Ti), or an additional galvanic Cu deposition (Ti-Cu). No Staphylococcus aureus were found in vitro on Ti-Cu after 24 h. Following simultaneous intramuscular implantation of two Ti and two Ti-Cu plates into nine rats, serum Cu was elevated until 48 h and residual Cu on explanted samples reduced accordingly after 48 h. Total and tissue macrophages around implants increased until 72 h for both series, and were increased for Ti-Cu. As numbers of total and tissue macrophages were comparable, macrophages were probably tissue-derived. MHC-class-II-positive cells increased for Ti-Cu only. T-lymphocytes had considerably lower numbers than macrophages, did not increase or differ between both series, and thus had minor importance. Tissue reactions increased beyond Cu release, indicating effects of either surface-bound Cu or more likely the implants themselves. Altogether, Ti-Cu samples possessed antibacterial effectiveness in vitro, released measurable Cu amounts in vivo and caused a moderately increased local inflammatory response, demonstrating anti-infective potential of Cu coatings.

Serum profile of pro- and anti-inflammatory cytokines in rats following implantation of low-temperature plasma-modified titanium plates

Surface modification of Titanium (Ti) by low-temperature plasma influences cell-material interactions. Therefore, this study aimed at examining serum cytokine levels and associations after intramuscular implantation (n = 8 rats/group) of Ti-plates with Plasma Polymerized Allyl Amine (Ti-PPAAm), Plasma Polymerized Acrylic Acid (Ti-PPAAc), and without such layers (Ti-Controls). Pro-inflammatory (IL-2, IFNγ, IL-6) and anti-inflammatory (IL-4, IL-10, IL-13) cytokines were measured weekly for 56 days. Ti-PPAAm caused increased IL-2 (d7-14, d35), increased IFNγ (d35) and decreased IL-10 (d35, d49-56). Ti-PPAAc induced divergent anti-inflammatory cytokine changes with increased IL-4 (d28-56) and decreased IL-10 (d42-56). Ti-Controls elicited increased IL-2 (d42) and IFNγ (d35-42, d56). IL-6 was not detected and IL-13 only in three samples, thus they do not influence the response against these Ti implants. Correlation analysis revealed surface-dependent associations between cytokines indicating the involvement of different inflammatory cell populations. Concluding, different plasma modifications induce specific serum cytokine profiles and associations indicating distinct inflammatory responses.

The 'equals sign': a novel marker in the diagnosis of fetal isolated cleft palate

OBJECTIVES

To determine the feasibility of visualization of the uvula and the soft palate during routine two-dimensional (2D) ultrasound examination and to develop a sonographic procedure that facilitates prenatal detection of isolated fetal cleft palate.

METHODS

We examined 667 consecutive patients with a singleton pregnancy between 20 and 25 weeks of gestation who were referred to our practice for a detailed fetal anomaly scan. The uvula was visualized either in a frontal section through the neck and pharynx or via a transverse section with subsequent slight tilting of the transducer. The soft palate was visualized in a median sagittal section through the head. To test whether the techniques described are suitable for inclusion in routine examinations, the time allowed for a normal ultrasound scan was not changed from 30 min.

RESULTS

A normal uvula could be visualized with a typical echo pattern (the 'equals sign') in 90.7% of the cases and the soft palate could be completely visualized in a median sagittal section in 85.3% of the cases. Visualization of at least one of the two structures (either the uvula or the soft palate) was successful in 98.4% of the cases. In one case an isolated cleft palate (in an otherwise normal fetus) was diagnosed; in one case with a cleft lip and palate, the cleft palate and the completely split uvula were detected. In 1.2% of the cases the examination did not provide sufficient information on either the uvula or the soft palate.

CONCLUSIONS

In a high percentage of cases, relevant soft palate structures can be visualized successfully with 2D ultrasound, permitting cleft palate to be ruled out in routine examinations. Visualization of the equals sign proves an intact palate. Absence of the equals sign indicates cleft palate and should prompt further examination of the soft palate in a median sagittal section. Cleft palate can be confirmed when the soft palate cannot be visualized. This technique also facilitates evaluation of the soft palate in the event of a cleft lip and palate.

Time course of fibronectin in the peri-implant tissue and neointima formation after functional implantation of polyester-based vascular prostheses with different porosity in pigs

Intima hyperplasia, resulting from extracellular matrix (ECM) secretion, can lead to vascular prosthesis occlusion and is a major problem in vascular surgery. Fibronectin might contribute to ongoing ECM secretion. However, the exact role of fibronectin and its influence on neointima formation remains unclear. This study was aimed at investigating the time course of the fibronectin area fraction and neointima formation following the functional implantation of three different polyester vascular prostheses into pigs. The infrarenal aorta from 15 animals (n = 5/group) was replaced by prosthesis segments with low, medium and high primary porosity. After 7, 14, 21, 28 and 116 days, the prostheses were morphometrically examined. Overall, the fibronectin area fraction was inversely correlated with the neointima thickness, demonstrating high fibronectin levels in the early phase (days 7 and 14) and low levels in the later phase with almost complete neointima formation (days 21-116). Throughout the study, fibronectin levels were highest at the proximal anastomosis region. The low porosity prosthesis had the highest fibronectin area fraction and a delayed neointima formation in the middle phase (days 21 and 28) but the highest neointima lining on day 116. The results indicate a relationship between fibronectin and neointima formation with the prosthesis porosity, demonstrating the importance of the textile design for tissue reactions following implantation.

Morphometric immunohistochemical examination of the inflammatory tissue reaction after implantation of calcium phosphate-coated titanium plates in rats

Calcium phosphate (CaP) preparations are established coatings for titanium-based medical implants used for bone reconstruction. However, biodegradation of the coating can result in microparticles that subsequently cause inflammatory reactions. The present study was therefore aimed at investigating the inflammatory response to two series of CaP-coated titanium plates: Ti-brushite (Ti-B) and Ti-hydroxyapatite (Ti-H) implants. Fifteen male LEW.1A rats received one plate of each series and a pellet (5 x 2 mm) of sol-gel derived silica/CaP (SCP implants) implanted into the back musculature. After 7, 14 and 28 days, five rats were killed and the implants were removed with the surrounding tissue. Quantitative immunohistochemistry was performed on frozen sections. Total monocytes/macrophages, tissue macrophages, T-cells, MHC-class-II-positive cells and proliferating cells were counted. For the Ti-B implants, the number of monocytes/macrophages remained constant while the other cell populations increased. In contrast, for the Ti-H implants the number of monocytes/macrophages decreased while the other cell populations remained constant. The SCP implants demonstrated degradation and scattering into smaller particles with an increase for all cell populations except the proliferating cells. Human mesenchymal stem cells demonstrated adherence and a flat morphology on Ti-B and Ti-H implants and no remarkable difference between both implants. Taken together, the in vivo data demonstrate that the short-term inflammatory response against a hydroxyapatite coating is lower in comparison to a brushite coating, and that the morphology of cells growing in vitro is similar on both layers.

Evaluation of the biocompatibility of a new vascular prosthesis coating by detection of prosthesis-specific antibodies

In recent experimental studies, we could demonstrate the occurrence of antibodies against the prosthesis matrix and coating following implantation of polyester-based vascular grafts. Therefore, this study aimed at evaluating the biocompatibility of a new absorbable polymer coating by detection of antibodies against the coating and the polyester matrix. Two polyester vascular prostheses coated either with the polymer (PP-prosthesis) or with gelatine (PG-prosthesis) were functionally implanted into sheep (n = 22 per group). Blood was drawn on days 1 (pre-OP) and 7, 14, 28, 56, 84, 140 (post-OP). Homogenates from both prostheses (PP-target or PG-target) or from an uncoated prosthesis (P-target) were used as assay targets in a particle-based immunoassay. The antibody binding against the P-target was significantly higher in the PP-group than in the PG-group on days 7-56, but not on days 84 and 140. Within both groups, no significant differences but a significant correlation between the binding against the P-target and the coated target was found. Therefore, the absorbable polymer did not induce a specific humoral immune response. In conclusion, the overall immunogenicity of the polymer-coated graft was comparable to the gelatine-coated graft. The detection of prosthesis-specific antibodies seems to be useful for in vivo biocompatibility testing.

Immune response against polyester implants is influenced by the coating substances

The aim of this study was to evaluate the influence of the coating of polymer implants upon the individual humoral immune response to the polymer matrix. Intramuscular implantation and explantation of samples from three different polyester vascular prostheses coated with collagen, gelatin, or human serum albumin was performed in LEW.1A rats and subsequently compared to sham operated control animals. Antibodies in serum samples were detected by means of enzyme immunoassays employing particles of pure polyester and the respective prosthesis, or solid phase bound coating substances as targets. In contrast to the controls, all animals with implants demonstrated a high antipolyester antibody response with a broad individual variability graduated according to the prosthesis coatings: gelatin > albumin > collagen. This was further significantly increased after the second implantation/first explantation and declined following the last explantation. Only animals with albumin-coated implants revealed specific antibodies to the coating as well as the strongest overall immunological reaction against the prosthesis already on day 8. Specificity of polymer antibodies was demonstrated by competitive inhibition of median antibody binding. Our results showed a specific immune reaction as a result of the applied polymer, which varied due to the surface-coating and individual factors.

Preoperative application of selective angiographic embolization in the treatment of focal nodular hyperplasia

A focal nodular hyperplasia (FNH) rarely requires surgical intervention unless complications or clinical symptoms come into play. In 2 female patients, ages 35 and 44, with symptomatic tumors of that entity (10 and 14 cm, respectively, in size) we performed a laparoscopic liver resection. Directly before undergoing this operation they underwent a selective angiographic embolization of the arterial inflow for control of hemorrhage by application of polyvinyl alcohol particles to the afferent arteries. This procedure led to a complete interruption in arterial inflow and the subsequent laparoscopic resection itself could be carried out as planned with minimal blood loss as well an uncomplicated postoperative course. The patients demonstrated a high degree of subjective satisfaction with the procedure. A reduction in arterial inflow through selective embolization is a useful tool in the preparation for laparoscopic resection of large, well-vascularized liver tumors.

Digital image analysis for morphometric evaluation of tissue response after implanting alloplastic vascular prostheses

The aim of this study was to examine the suitability of digital image analysis, using the KS400 software system, for the morphometric evaluation of the tissue response after prosthesis implantation in an animal model. Twenty-four female pigs aged 10 weeks were implanted with infrarenal Dacron(R) prostheses for 14, 21, 28, and 116 days. Following the explantation and investigation of the neointima region, the expression of beta-1-integrin, the proliferation rate by means of Ki-67 positive cells, and the intima thickness were evaluated as exemplary parameters of the tissue response after implantation. Frozen tissue sections were immunohistochemically stained and subsequently examined using computer-aided image analysis. A maximum expression of 32.9% was observed for beta-1-integrin 14 days after implantation, gradually declining over time to 9.8% after 116 days. The proliferation rate was found to be 19% on day 14, increasing to 39% on day 21 with a subsequent gradual decline to 5% after 116 days. The intima thickness increased from 189.9 microm on day 14 to 1228.0 microm on day 116. In conclusion, digital image analysis was found to be an efficient and reproducible method for the morphometric evaluation of a peri-prosthetic tissue response.

Antibody response to collagen after functional implantation of different polyester vascular prostheses in pigs

Besides inflammation, specific immune responses are seen also after implantation of biomaterials. The aim was to investigate the humoral response to bovine collagen type I following implantation of various polyester (Dacron) prostheses into pigs. In 24 randomized pigs, the infrarenal aorta was replaced with a segment of collagen-impregnated, woven polyester prosthesis of low, medium, or high porosity. IgG antibodies were detected by immunoassay using native and denatured collagen type I as a target for blood samples taken on day 1 (implantation), 10, 17, 24, 62, and 116. As generally observed, antibodies to native and denatured collagen are of low titer and were significantly correlated with enhanced binding to the denatured form (p < 0.001). The highest overall antibody prevalence to native and denatured collagen was obtained on day 116 with 68% and on day 62 with 59%, respectively. Prostheses with high porosity induced an early immune response on day 10; those with low and medium porosity induced the highest antibody levels later after 2 months. Collagen antibodies neither correlated with serum IgG contents nor with antibodies to the prosthesis polyester matrix. Thus, humoral immune response against implant components may provide a further parameter in describing biocompatibility but also a potential marker that may facilitate monitoring of individual perigraft reaction.

[Vaccination for stab and bite injuries in the facial region]

In cases of stab and bite injuries to the face there is a risk of general infection and the necessity for an active and/or passive immunization must be considered by the first treating physician. In Central Europe tetanus, rabies, hepatitis B and C as well as HIV must be taken into account as possible consequences of such injuries. With regard to a tetanus immunization the indication for the post-exposition prophylaxis (PEP) should generally be as wide as possible. For other protective vaccinations a differentiated decision in co-operation with other fields of activity and public health authorities should be realized. The current recommendations for the systemic infections relevant in Central Europe are described.

Die intraoperative laparoskopische Cholangiografie - Wann ist sie sinnvoll?

Since the introduction of laparoscopic cholecystectomy (LC), a decrease in the practice of intraoperative cholangiography (IOC) has been reported. Are there actually reasons for carrying on IOC during LC? Depending on the management of common bile duct (CBD) stones treatment a different IOC regime is recommended. If the single-stage laparoscopic extraction of ductal calculi during LC is preferred, routine IOC is generally necessary to detect all CBD stones for desobstruction via ductus cysticus or choledochotomy. When therapeutic splitting is favoured, including two-stage management with endoscopic desobstruction and later LC, routine IOC can be foregone. However, selective practice of IOC can help to reduce the rates of unnecessary preoperative investigations from 40-60 % to 20 % when postoperative endoscopic desobstruction demonstrates similar success rates of about 95 %. Regarding the preventive character of laparoscopic IOC to CBD injuries, a routine investigation should be adopted by institutions with injury rates > 0.4 % and in the learning phase of young surgeons. For all other institutions a selective practice should be recommended when difficult intraoperative conditions render recognition of the anatomical situation more difficult or for identification of dissected non-bleeding ducts near the triangle of Calot.

The influence of antimicrobial treatments on the cytocompatibility of polyurethane biosensor membranes

The cytocompatibility of polyurethane membranes was tested following ultraviolet or gamma irradiation as well as treatment with hydrogen peroxide or glutaraldehyde containing solutions. Despite the fact that all of the methods had been recommended for antimicrobial treatment of glucose biosensors, the treatments investigated significantly influenced cytocompatibility characteristics. Cytotoxicity of membrane eluates was not observed following irradiation treatments. This was also the case when the membranes were repeatedly washed following chemical treatment. Cell growth upon the membranes was stimulated to a different extent after gamma and UV irradiation as well as following hydrogen peroxide treatments. Residues of an urea-based hydrogen peroxide inclusion compound caused a restriction in cell growth upon the membranes as was similarly observed with 2 and 4% glutaraldehyde solutions acting over 2 and 4 h, respectively. It is concluded that cytocompatibility in vitro reflecting the host response against a biomaterial in vivo does not only depend upon the material itself but also upon antimicrobial treatments which could have consequences for its bioperformance characteristics.

[Minimally invasive options for gastric tumors]

INTRODUCTION

Depending on the origin of the tumor tissue, gastric tumors may be more or less accessible for biopsy diagnostics. However, especially submucous tumors present a diagnostic problem. Entity and dignity may remain unclear particularly in larger tumors and may not be clarified before operative excision via gastrotomy and frozen section diagnostics. Similar problems may occur in the diagnostics of epithelial tumors, if a reliable appraisal of the dignity based on forceps biopsy is impossible. To clarify their entity and dignity, tumors can be completely extirpated with minimally invasive techniques.

PATIENTS AND METHODS

Apart from the endoscopic mucosa resection (EMR), laparoscopic intragastric tumor resection and laparoscopic wedge resection were performed, especially in larger tumors. In the period from December 1999 to December 2001, we saw an indication for minimally invasive procedures in 22 patients. There were 5 cases of submucous tumors of unclear entity and 17 epithelial lesions. The epithelial lesions included 12 patients with tumors of unclear dignity and five cases with early gastric carcinomas.

RESULTS

The EMR was performed without complications in all 14 cases. One of the three cases with wedge resection was followed by a gastrectomy for oncological reasons. One early postoperative bleeding occurred, which was controlled laparoscopically. Conversion to open surgery due to technical problems was necessary in two cases of laparoscopic intragastric resection, and in one case a gastrectomy was required for oncological intention.

CONCLUSION

Beside the diagnostic aspect, the mentioned techniques also enable a minimally invasive therapy of locally excisable gastric tumors. In addition to benign and low grade malignant lesions, early gastric carcinomas of the intestinal type present an indication.

Pathophysiological measurement and results after laparoscopic fundoplication for gastroesophageal reflux disease

PURPOSE

Both surgical and conservative treatments for gastroesophageal reflux disorder (GERD) are controversial. The aim of this prosepective study was to examine outcomes after laparoscopic antireflux surgery.

METHODS

The subjects were 143 patients who underwent laparoscopic antireflux surgery. Following diagnostic procedures 126 patients were allocated to a total fundoplication group (360 degrees C, Nissen-DeMeester) and 17, to a posterior semifundoplication group (250-270 degrees, Toupet). All complications were registered, and pathophysiological and outcome data were examined 3, 6, and 9 months after surgery.

RESULTS

By 6 months after surgery the mean lower esophageal sphincter (LES) pressure had improved significantly, to 14.8 mmHg in the Nissen-DeMeester group, and to 12.1 mmHg in the Toupet group, corresponding to successful prevention of esophageal reflux in both groups. Dysphagia was more common in the early postoperative period after total fundic wrap (17% vs12%), but this difference disappeared in time. All patients reported complete relief of reflux symptoms, although two of those who underwent the Nissen-DeMeester fundoplication experienced relapse of GERD and required open reconstruction (1.4%). The laparoscopic procedure was converted to open surgery in three patients (2%). There were no associated deaths and the perioperative complication rate was 4.2%.

CONCLUSION

Laparoscopic antireflux surgery is an effective treatment for GERD. More than 93% of the patients in this series rated their outcome as good to excellent following the operation.

Laparoscopic-endoscopic rendezvous resection of gastric tumors

BACKGROUND

Submucosal and mucosal tumors of the stomach display a wide spectrum of histopathologic and prognostic characteristics. Biopsies obtained using endoscopic techniques often do not provide the representative histologic sample needed for further therapeutic decisions.

METHODS

From 1999 to 2002, 18 patients with gastric tumors underwent a combined endoscopic-laparoscopic local resection of the tumors using two different procedures and were prospectively analyzed. Tumors of the posterior wall were resected using laparoscopic intragastral resection (LIR). Tumors located in the anterior wall were resected using lesion-lifting or the laparoscopic wedge resection (LWR) approach.

RESULTS

Laparoscopic resections were performed in 18 patients. The mean age of the patients was 64.4 years (range, 38-81 years). Preoperative preparation included endoscopy with biopsies and histologic examination, ultrasound examination, computed tomography scan, and endoscopic ultrasonography. We performed the LWR on 10 patients and the LIR on 8 patients. After resection, the final immunohistologic examination of the specimens showed gastrointestinal stroma cell tumors in nine cases, neurinomas or benign neurofibrotic tumors in four cases, and one leiomyoma. Four additional patients with mucosal early gastric cancer and high comorbidity risks also underwent a limited full-thickness wedge resection. In all the patients, the surgical margins were tumor free, and no lymphatic or venous invasion was encountered in pathologic specimens. Method-specific complications occurred in one case (perforation of the stomach wall). No fatal outcome had to be registered.

CONCLUSIONS

When selected properly, the laparoscopic-endoscopic approach is considered to be curative and minimally invasive for resection of localized gastric tumors. In cases of histopathologically unknown tumors preoperatively, definitive examination of the complete specimen provides the basis for further therapeutic decisions.

Immunogenicity of polymeric implants: long-term antibody response against polyester (Dacron) following the implantation of vascular prostheses into LEW.1A rats

Implanted biomaterials trigger acute and chronic inflammatory responses directly correlated to the central role of phagocytic cells at the host-implant interface. This study was designed to evaluate specific humoral immune responses following repeated intraperitoneal implantations of collagen-impregnated polyester (Dacron) prosthetic segments into LEWIS rats. Serum antibody detection was performed by enzyme immunoassay with the prosthetic segments as a target. Cutoff values for antibody positivity were greater than or equal to the 99th percentile for control rats. Polymer immunoglobiulin G (IgG) antibodies were significantly increased (p < 0.05) by repeated implantation and were subsequently followed until experimental day 293. Antibody formation was significantly enhanced through the application of complete Freund's adjuvant in combination with the first implantation. All rats within this group were antibody-positive on day 53, but only 6 of 10 animals that received the prosthesis without the adjuvant were. After preincubation of sera with bovine collagen type I (solid phase adsorbed or in solution), polymer antibody binding was discovered not to be diminished, indicating that the IgG antibodies detected were not directed against the prosthesis impregnation. Furthermore, a significant correlation was obtained between polymer antibody binding to collagen-impregnated and nonimpregnated prostheses (r(s) = 0.797, p < 0.001). There was no substantiated correlation between antibody binding to polyester and to an irrelevant polymer (Tecoflex EG 80). We conclude that specific polymer antibodies may indeed provide an additional parameter for biocompatibility testing as well as a possible serological marker of an inflammatory response to implants.

Caustic acid burn of the upper gastrointestinal tract: first use of endosonography to evaluate the severity of the injury

Judging the severity of an injury after erosions of the upper gastrointestinal tract has been exclusively based on endoscopic inspection. For the first time, we used minimal probe endosonography during initial endoscopy and endoscopical progress observations to improve assessment of injury depth determining the therapy. Nine hours after admitting a patient after acid ingestion, the initial endoscopy and simultaneous endosonography with a 12-MHz minimal endosonographical probe took place. The affected wall sections with macroscopical coagulation necrosis regularly showed a richer echo, broadened first layer, and a low-echo wall edema that had developed under the necrosis. Differences existed between the breadth of the first echo-rich layer and the breadth of the edema below it. The indiscriminability of single wall layers correlated with the intensity of the edema. The initial injury depth was defined based on the depth extension of the wall edema and the discriminability of the layers. In the control examinations, a complete wall edema with limited assessability developed independently of the injury's initial severity. The assessment of injury depth was only possible during a short time span. Differences existed in the regression time of the wall edema. The initial endosonography and diagnostic findings over time showed differences between superficial and deep wall injuries after erosion. In this way, the injury depth could be correctly estimated, thus directly influencing therapy planning.

[Prospective study on patients outcome following laparoscopic vs. open cholecystectomy]

AIMS OF THE STUDY

Differences in outcome between patients undergoing laparoscopic (LC) vs. open cholecystectomy (OC) should be examined under objective and subjective aspects.

METHODS

We prospectively evaluated the postoperative course of 135 patients who underwent LC or OC in 1999. In the first step we examined the recover period with the help of the modified McPeek-Index. In the second phase during a 35 postoperative days-spanned analysis all patients noted there physical, emotional and social well-being in a circulating standard questionnaire, based on the modified Gastrointestinal Quality Life Index (GIQLI).

RESULTS

Responses were obtained from 103 patients (76.3 %) undergoing 29 OC and 74 LC. 21.4 % of the patients aged 70 and older or had perioperative risks > II in ASA-Classification (LC 19.8 vs. OC 30.1 %). The (objective) McPeek-Outcome was similar in both groups, with no statistical advantage for LC (best score: 69 % LC vs. 62 % OC). The subjective assessment of the patients showed that patients having LC felt fully fit 10.2 days earlier than patients after OC (23.9 vs. 34.1 days). Patients in the LC-group returned to work after an average of 24.7 days, compared with 42.2 days following OC. The main finding of the postal questionnaire was a significantly earlier recruitment in physical, emotional and social status following LC in the group of aged > 70 and > ASA II-Score-patients, in contrast to control-OC-group.

CONCLUSION

The study suggests an additional advantage in surgical outcome after LC, in comparison to OC. The laparoscopic approach is the preferable procedure to treat especially older and comorbide patients, when local or anesthesiological contraindications are absent.

Endocrine effects of dopexamine vs. dopamine in high-risk surgical patients

OBJECTIVES

To compare the endocrine effects of dopexamine and dopamine on prolactin (PRL), dihydroepiandrosterone sulfate (DHEAS), cortisol, thyrotropin (TSH), and peripheral thyroid hormone serum concentrations in surgical patients at risk of developing postoperative complications because of hypoperfusion of various organ systems.

DESIGN AND SETTING

A prospective, randomized, placebo-controlled, blinded clinical trial in an adult surgical intensive care unit in a university hospital.

PATIENTS

Thirty-two male surgical risk patients undergoing elective major abdominal surgery.

INTERVENTIONS

Patients were randomized to receive placebo ( n=8), dopexamine (0.5 microg kg(-1) min(-1), n=8), dopexamine (1 microg kg(-1) min(-1), n=8) or dopamine (5 microg kg(-1) min(-1), n=8) on the first postoperative day.

MEASUREMENTS AND RESULTS

All patients received either a placebo or catecholamine infusion for 24 h. Blood samples were obtained every 2 h for the next 2 days. PRL, DHEAS, cortisol, TSH, triiodothyronine, thyroxin, free triiodothyronine, and free thyroxin serum concentrations were determined by radioimmunoassay or luminescence immunoassay. Dopexamine (0.5 microg kg(-1) min(-1)) had no effects on serum concentrations of PRL or TSH. Higher doses of dopexamine (1 microg kg(-1) min(-1)) suppressed PRL secretion significantly, but not TSH. In contrast, infusion of dopamine (5 microg kg(-1) min(-1)) completely inhibited PRL and TSH secretion. DHEAS, cortisol, and thyroid hormone serum concentrations were not affected by either dopexamine or dopamine infusion. Measurements of hemodynamic parameters, peripheral oxygen saturation, diuresis, blood gases, and standard laboratory parameters were repeated hourly. Significant differences were not found between placebo, dopexamine (0.5 microg kg(-1) min(-1)) and dopamine (5 microg kg(-1) min(-1)) group. Dopexamine at 1 microg kg(-1) min(-1) increased the heart rate significantly.

CONCLUSIONS

Routine postoperative optimizing of men undergoing abdominal surgical procedures with dopexamine at higher doses or dopamine induces at least partial hypopituitarism, which may possibly affect postoperative morbidity.

Conservative treatment of ectopic pregnancy in a cesarean section scar with methotrexate: a case report

Ectopic pregnancies sited in dehiscent cesarean section scars have a high risk of rupture and bleeding. Attempts at operative therapy frequently end in loss of the uterus. A connection with the cavum uteri justifies an attempt at dilatation and curettage. We describes a patient with combined systemic and local intra-amniotic methotrexate (MTX). The uterus was preserved.

Antigenicity of Polyester (Dacron) Vascular Prostheses in an Animal Model

Objectives to investigate the specific humoral immune response to three different polyester (Dacron) prostheses in pigs. Design, materials and methods twenty-four growing pigs were randomly divided into three groups. The infrarenal aorta was replaced by a segment of collagen-impregnated woven polyester prosthesis (low, medium and high porosity). Serum antibodies were detected by modified enzyme immunoassay using non-impregnated prosthesis as the target for the blood samples taken on experimental days 1, 10, 17, 24, 62 and 116 of the 22 pigs followed over the whole observation period. Results significantly enhanced (p <0.05) mean IgG antibody binding against polyester was detected on experimental days 10, 17, 24 and 62 with antibody prevalences of 41%, 41%, 32% and 37%, respectively. Antibody positive pigs were divided into early responders (n =9) and late responders ( n =5) with antibody detection on day 10 and/or 17 vs day 62 and/or 116. No significant differences between the three different prostheses were found. The formation of specific IgG antibodies against polyester in the animals investigated demonstrates a broad individual variability. Conclusions polyester is an antigenic polymer. Specific antibodies, reflecting the inflammatory response, might be not only a parameter for testing biomaterials but also for determining individual bio(in)compatibility for long-term biomaterial function.

[Examination of resistance of the lens capsule against the waterjet]

BACKGROUND

Although cataract surgery is highly developed today, there are still problems such as secondary cataract. In polishing the posterior capsule lens, epithelial cells often remain, causing secondary cataracts. Additionally, there are the problems of tissue heating and endothelial cell loss during phacoemulsification by ultrasound. This could be another field for improvement of cataract surgery by using the waterjet.

METHODS

After removing the cornea of freshly enucleated porcine bulbs, we used the water jet from 4 to 12 bar. The hit angel on the capsule varied between 45 degrees and 90 degrees.

RESULTS

Rupture of the posterior capsule occurred at a mean of 8.5 bar using the jet at 45 degrees and a mean of 8.6 bar using the jet at 90 degrees.

CONCLUSION

The waterjet pressure should not be over 4 bar during polishing of the posterior capsule.

Aetiological findings and associated factors in children with severe mental retardation

The purpose of this study, through a retrospective epidemiological survey carried out over three geographical areas in France, was to characterize the aetiological factors involved in severe mental retardation (SMR) within a geographically defined population of children with disabilities aged between 7 and 16 years. The inclusion criteria for SMR (IQ<50) were met by 1150 children born between 1976 and 1985. Of these children, aetiology was known in 25%, suspected (or unclear) in 26%, and unknown in 49%. These rates of known and suspected aetiology varied between the groups of children with CP and those without CP. An analysis of factors associated with SMR was undertaken among the 144 subjects with SMR, of suspected or unknown aetiology, who had been referred to a neonatal care unit with or without intensive care (NCU) during their neonatal period. These subjects with SMR were compared with 864 children without SMR (control children) who were also referred to an NCU during their neonatal period. The main specific associated factors were a prolonged intubation of more than 24 hours, a very low birthweight (<1500 g) for children with an associated clinical feature of CP, and the presence of isolated neonatal fits and a time of transfer to the NCU of more than 4 hours after birth for children without an associated clinical feature of CP. Although common associated factors were encountered in the children with SMR with CP and the children with SMR without CP, the results of this study suggest differences in the underlying pathogenic factors.

Mitoxantrone combined with paclitaxel as salvage therapy for platinum-refractory ovarian cancer: laboratory study and clinical pilot trial

This report describes preclinical and early clinical investigations of the mitoxantrone/paclitaxel combination (NT) for patients with platinum-refractory ovarian cancer. The preclinical activity of NT was studied ex vivo, evaluating native tumor specimens with the ATP tumor chemosensitivity assay. Of 24 tumors tested, 20 (83%) were sensitive to NT, whereas 7 (29%) responded to mitoxantrone and 8 (33%) responded to paclitaxel. In the majority of tumors assayed (19 of 24), potentiating or major independent effects between both agents were found. Subsequently, a clinical pilot trial of NT was initiated for patients with platinum-refractory ovarian cancer. Patients had failed one to four (median, two) prior chemotherapy regimens. In 11 cases, NT was administered every three weeks with 8 mg/m2 mito-xantrone and 180 mg/m2 paclitaxel (NT-I). Seven patients were treated biweekly with 6 mg/m2 mitoxantrone and weekly with 100 mg/m2 paclitaxel (NT-II). During 92 NT courses, myelosuppression with leucopenia, anemia, and thrombocytopenia was the limiting toxicity, occurring more frequently with NT-II. No patient required hospitalization due to any life-threatening complication. Five complete and nine partial remissions were observed with both NT-I and NT-II, accounting for an overall 78% response rate, with a median progression-free survival of 40 weeks. One patient showed early progression during therapy. Currently, three patients (NT-I, two; NT-II, one) have died due to progressive relapsed ovarian cancer, so that the median overall survival is not reached after a median follow-up of 40.5+ weeks. Both schedules were found to be equal in terms of response rate and overall survival. NT is highly active and practical for salvage treatment of ovarian cancer. NT-II may be preferred due to both clinical activity and patients' acceptance. However, NT-I seems to be a less myelotoxic alternative. Both schedules warrant further clinical investigation.

[Simultaneous long-term measurement of duodenogastric reflux and gastroduodenal motility]

We combined a newly developed ambulatory fiberoptic system for detecting intragastric bilirubin (Bilitec 2000, Synectics Medical Inc., Sweden) with prolonged measurement of gastroduodenal motility in 10 healthy volunteers and 10 patients followed BI resection. Circadian intragastric bilirubin exposure and the total number of tremendous changes of bilirubin absorption (more than 20%, over a period of at least 5 min) were significantly increased in the BI-resected patients (P < 0.05). In patients the interdigestive motility cycle (IMC) was characterized by the appearance of several types of abnormally propagated phase III activity fronts. Of the tremendous increases of bilirubin absorption in the patient group, 90.1% were associated with abnormally propagated phase III activity fronts. In cases of increased duodenogastric reflux, the combination of ambulatory intragastric bilirubin measurement and long-term manometry seems to be feasible to assess motility and reflux simultaneously.

[Modification of phagocytic microbicide function by antifungal agents--measuring luminol enhanced chemoluminescence in full blood]

Fungus infections are becoming more important in surgical intensive medicine, and various preparations are now available to treat them. The goal of our investigations was to determine the influence of the antimycotics in current use on the microbicide phagocytic function by measuring chemiluminescence. To this end the luminol-enhanced chemiluminescence in whole blood samples from a total of 29 healthy donors was measured with a LKB 1251 Luminometer after stimulation with zymosan or a Canadida albicans preparation. We tested the substances amphotericin B, flucytosin (Ancotil), fluconazol (Diflucan) and itraconazol (Sempera), each in three different concentrations within the recommended dose range and compared the results with those in an untreated sample. For the insertions of amphotericin B or intraconazol after zymosan stimulation no significant differences in the measurements were found (50.84 vs 47.99 mV and 46.10 vs 47.89 mV) compared with the blank test. Similar situations revealed by the tests with C. albicans administration (15.21 vs 12.35 mV and 11.16 vs 11.91 mV). However, the tests with flucytosin in the higher concentration range, after stimulation with either zymosan or C. albicans, evidenced a significant reduction in the measurements (34.70 vs 52.74 mV, P<0.005, and 10.98 vs 14.57 mV, P<0.01). The tests with fluconazol showed a decrease of the chemiluminescence exclusively for the highest concentration in the C. albicans group (14.36 vs 17.20 mV, P<0.005). Our results indicate a negative influence of the phagocytes on the oxidative metabolism especially with flucytosin in the higher concentrations. This emphatically confirms demands for exact indications and dosage of antimycotics and their correct administration.

[Child health in the states of Ceará, Rio Grande do Norte and Sergipe, Brazil: description of a methodology for community diagnosis]

No reliable data are available from most Brazilian states for a number of child health indicators, such as nutritional status, breast feeding, vaccine coverage, incidence and management of infectious diseases, and coverage of antenatal and perinatal services. However a methodology has been developed for state-wide, community-based health surveys for the obtaining of such information, which was recently applied in studies of representative samples of children from the states of Ceará, Sergipe and Rio Grande do Norte in Northeastern Brazil. The present report describes the key aspects of this methodology and some of the main findings. These results point out to the need for promoting breast feeding, increasing vaccine coverage, improving diarrhoea management with oral rehydration therapy and investing in antenatal and perinatal care, as well as in growth monitoring. They also show that child survival activities are paradoxically concentrated on higher-income, lower risk children. Besides contributing to the planning and evaluation of health programs, community-based child health surveys provide baseline data against which future progress may be ascertained.

Effects of interleukin 2 and large envelope glycoprotein (gp 120) of human immunodeficiency virus (HIV) on lymphocyte proliferative responses to cytomegalovirus

Lymphocytes from many HIV-infected asymptomatic individuals or patients with AIDS-related conditions (ARC) and from all AIDS patients were unable to proliferate in vitro in response to UV-inactivated cytomegalovirus (CMV). The addition of recombinant IL2 (rIL2) restored proliferative responses of lymphocytes from most HIV-infected asymptomatic individuals and ARC patients to levels similar to those of HIV-seronegative (HIV-) CMV-seropositive (CMV+) individuals. In contrast, rIL2 augmented CMV-specific lymphocyte proliferation of only 33% (6/18) of AIDS patients. Proliferative responses to CMV with or without rIL2 did not correlate well with the levels of CD4+ lymphocytes, HIV antigen levels or ratios of CD4+ and CD8+ lymphocytes. Proliferative responses to CMV were inhibited by relatively high concentrations (greater than or equal to 10 micrograms/ml) of recombinant HIV envelope glycoprotein (rgp120) and this immunosuppression was completely overcome by rIL2. These results indicate that defects in antigen-driven lymphocyte responses of HIV-infected individuals are not simply the result of reduced numbers of CD4+ lymphocytes but are influenced by defects in IL2 pathways and by immunosuppressive effects of HIV gp120.