Multi-laboratory evaluation of the reproducibility of polymer biodegradation assessments applying standardized and modified respirometry methods

This research evaluated the intra- and interlaboratory variability when applying OECD 301F and OECD 301B Ready Biodegradation respirometric test methods to quantify polymer biodegradation as well as the impact of method modifications including test duration, inoculum level and test substance concentration on results. This assessment synthesizes results of mineralization studies on 5 polymers of varying structural components, molecular weight, charge, and solubility, evaluated at 8 different laboratories in 4 different countries, providing significant geographic variation in inoculum source as well as lab to lab variations in test setup. Across all laboratories, intralaboratory variability was low (≤18 % absolute difference) indicating the reproducibility of results between replicates and uniformity of test setup in each laboratory. Interlaboratory variation was also low for all 5 polymers with extent of mineralization being comparable in all OECD 301F and 301B studies even when test methods were modified. Across all studies mean mineralization was 89 ± 5.5 % for polyethylene glycol 35,000, 85 ± 7.4 % for polyvinyl alcohol 18-88, 44 ± 13 % for carboxymethyl cellulose (DS 0.6), 48 ± 4.1 % for a modified guar gum, and 88 ± 6.2 % for microcrystalline cellulose (MCC) at study completion. Due to the lack of polymeric reference materials, MCC was evaluated and found to be a suitable reference material for polymers that biodegrade rapidly in screening studies. An additional respirometric study was conducted quantifying mineralization of the 5 polymers in river water to evaluate the relationship with OECD 301 results using activated sludge as the inoculum. A similar extent of mineralization was observed for all 5 polymers in the OECD 301 and river water studies but time to reach the maximum extent of mineralization was longer using river water as the inoculum source likely due to the lower microbial counts (106 CFU/L) in the test system.

281 Impact of Using Risk Communication Tools in Counselling Patients with Newly Diagnosed Non-Metastatic Prostate Cancer

Introduction

There have been substantial advances in risk communication tools that help patients understand prognosis associated with prostate cancer and the benefit/gain from treatment. Over the last three years, two tools; Cambridge Prognostic Groups (CPG), and Predict Prostate (https://prostate.predict.nhs.uk), along with decision-making consultations with clinical nurse specialists (CNS) have been integrated into the new diagnosis pathway in our unit.

Method

Treatment decisions for patients with new non-metastatic prostate cancer were audited after (2019–2020) and before (2016–2017) new risk communication tools were implemented. Data were compared between the two time periods and also benchmarked against national level data from the National Prostate Cancer Audit (NPCA) (Parry et al 2020; PMID: 32460859). The main outcome measured was comparison of rates of over and under-treatment of disease.

Results

168 and 95 patients were included in the 2019–2020 and 2016–2017 cohorts, respectively. Following implementation there was a reduction in over-treatment (use of radical surgery/radiotherapy) in patients with low risk/CPG1 (23% to 4%). These rates were also better than the national average from NPCA data (4% vs 11%). In parallel, there was an increase in use of radical treatment (reduced under-treatment) in high risk and very high-risk/CPG4-5 disease (84% vs 73%). Again, these rates were also superior to national level data from the NPCA (84% vs 76%).

Conclusions

Incorporating personalised risk-communication tools and dedicated CNS counselling in our unit has reduced over-treatment of early disease and under-treatment of advanced disease. Wider uptake could enhance risk-appropriate treatment of patients with a new prostate cancer diagnosis.

[Selection criteria for neoadjuvant chemoradiotherapy of rectal cancer : Neoadjuvant therapy even for locally advanced colon cancer?]

During the last two decades a neoadjuvant treatment concept has been established for an increasing number of malignant tumors of the gastrointestinal tract; however, these concepts are still subject to a constant change concerning the indications and type of treatment. A prime example for this is rectal cancer. The rate of local recurrence in particular was significantly reduced by neoadjuvant therapy but until now it has not been possible to validly show an improvement in overall or disease-free survival. At the beginning of the millennium it was recommended to treat every rectal carcinoma in UICC stages II and III with neoadjuvant therapy, independent of the height localization. In the meantime this has increasingly been relativized and only locally advanced tumors of the middle and lower thirds of the rectum should be pretreated, whereas tumors of the upper third of the rectum should basically be treated in the same way as colon cancer. It is to be expected that there will be further differentiation concerning the indications in this context in the future mainly based on a preoperative magnetic resonance imaging (MRI) examination. At the same time, initial studies for colon cancer show that neoadjuvant chemotherapy can be beneficial and that an optimized computed tomography (CT) scan can be a worthwhile tool with respect to pretherapeutic stratification of patients.

Nationwide in-hospital mortality rate following rectal resection for rectal cancer according to annual hospital volume in Germany

Background

The impact of hospital volume after rectal cancer surgery is seldom investigated. This study aimed to analyse the impact of annual rectal cancer surgery cases per hospital on postoperative mortality and failure to rescue.

Methods

All patients diagnosed with rectal cancer and who had a rectal resection procedure code from 2012 to 2015 were identified from nationwide administrative hospital data. Hospitals were grouped into five quintiles according to caseload. The absolute number of patients, postoperative deaths and failure to rescue (defined as in‐hospital mortality after a documented postoperative complication) for severe postoperative complications were determined.

Results

Some 64 349 patients were identified. The overall in‐house mortality rate was 3·9 per cent. The crude in‐hospital mortality rate ranged from 5·3 per cent in very low‐volume hospitals to 2·6 per cent in very high‐volume centres, with a distinct trend between volume categories (P < 0·001). In multivariable logistic regression analysis using hospital volume as random effect, very high‐volume hospitals (53 interventions/year) had a risk‐adjusted odds ratio of 0·58 (95 per cent c.i. 0·47 to 0·73), compared with the baseline in‐house mortality rate in very low‐volume hospitals (6 interventions per year) (P < 0·001). The overall postoperative complication rate was comparable between different volume quintiles, but failure to rescue decreased significantly with increasing caseload (15·6 per cent after pulmonary embolism in the highest volume quintile versus 38 per cent in the lowest quintile; P = 0·010).

Conclusion

Patients who had rectal cancer surgery in high‐volume hospitals showed better outcomes and reduced failure to rescue rates for severe complications than those treated in low‐volume hospitals.

Targeting bromodomain-containing protein 4 (BRD4) inhibits MYC expression in colorectal cancer cells

The transcriptional regulator BRD4 has been shown to be important for the expression of several oncogenes including MYC. Inhibiting of BRD4 has broad antiproliferative activity in different cancer cell types. The small molecule JQ1 blocks the interaction of BRD4 with acetylated histones leading to transcriptional modulation. Depleting BRD4 via engineered bifunctional small molecules named PROTACs (proteolysis targeting chimeras) represents the next-generation approach to JQ1-mediated BRD4 inhibition. PROTACs trigger BRD4 for proteasomale degradation by recruiting E3 ligases. The aim of this study was therefore to validate the importance of BRD4 as a relevant target in colorectal cancer (CRC) cells and to compare the efficacy of BRD4 inhibition with BRD4 degradation on downregulating MYC expression. JQ1 induced a downregulation of both MYC mRNA and MYC protein associated with an antiproliferative phenotype in CRC cells. dBET1 and MZ1 induced degradation of BRD4 followed by a reduction in MYC expression and CRC cell proliferation. In SW480 cells, where dBET1 failed, we found significantly lower levels of the E3 ligase cereblon, which is essential for dBET1-induced BRD4 degradation. To gain mechanistic insight into the unresponsiveness to dBET1, we generated dBET1-resistant LS174t cells and found a strong downregulation of cereblon protein. These findings suggest that inhibition of BRD4 by JQ1 and degradation of BRD4 by dBET1 and MZ1 are powerful tools for reducing MYC expression and CRC cell proliferation. In addition, downregulation of cereblon may be an important mechanism for developing dBET1 resistance, which can be evaded by incubating dBET1-resistant cells with JQ1 or MZ1.

[Incidental finding of mucinous neoplasia of the appendix : Treatment strategies]

Tumors of the appendix are not a uniform group but differ significantly in terms of their origin/histology and metastatic behavior. Furthermore, tumors of the appendix are often diagnosed as incidental findings after appendectomy for acute appendicitis. A subgroup of these neoplasms are low-grade appendiceal mucinous neoplasms (LAMN). These are mucus-forming tumors of the appendiceal lumen, which can lead to rupture of the appendix and seeding into the abdominal cavity. Therefore LAMN are considered precursors of pseudomyxoma peritonei (PMP). It is essential to clearly differentiate the subgroups of LAMN as well as the resection status. According to this it is determined whether (radical) appendectomy is a sufficient therapy or further treatment, such as ileocecal resection with hyperthermic intraperitoneal chemotherapy (HIPEC) or cytoreductive surgery (CRS) is necessary. There is no standardized concept regarding the follow-up after resection of LAMN. Generally, it is recommended to perform a computed tomography (CT) scan of the abdomen and determination of tumor markers 6 months postoperatively and then once a year. A recommendation regarding the duration of follow-up is difficult as there are case reports in which PMP has occurred more than 15 years after removal of LAMN.

Nationwide in-hospital mortality following colonic cancer resection according to hospital volume in Germany

Background

Colonic cancer is the most common cancer of the gastrointestinal tract. The aim of this study was to determine mortality rates following colonic cancer resection and the effect of hospital caseload on in‐hospital mortality in Germany.

Methods

Patients admitted with a diagnosis of colonic cancer undergoing colonic resection from 2012 to 2015 were identified from a nationwide registry using procedure codes. The outcome measure was in‐hospital mortality. Hospitals were ranked according to their caseload for colonic cancer resection, and patients were categorized into five subgroups on the basis of hospital volume.

Results

Some 129 196 colonic cancer resections were reviewed. The overall in‐house mortality rate was 5·8 per cent, ranging from 6·9 per cent (1775 of 25 657 patients) in very low‐volume hospitals to 4·8 per cent (1239 of 25 825) in very high‐volume centres (P < 0·001). In multivariable logistic regression analysis the risk‐adjusted odds ratio for in‐house mortality was 0·75 (95 per cent c.i. 0·66 to 0·84) in very high‐volume hospitals performing a mean of 85·0 interventions per year, compared with that in very low‐volume hospitals performing a mean of only 12·7 interventions annually, after adjustment for sex, age, co‐morbidity, emergency procedures, prolonged mechanical ventilation and transfusion.

Conclusion

In Germany, patients undergoing colonic cancer resections in high‐volume hospitals had with improved outcomes compared with patients treated in low‐volume hospitals.

Effects of anastomotic technique on early postoperative outcome in open right-sided hemicolectomy

Background

Despite recent improvements in colonic cancer surgery, the rate of anastomotic leakage after right hemicolectomy is still around 6–7 per cent. This study examined whether anastomotic technique (handsewn or stapled) after open right hemicolectomy for right‐sided colonic cancer influences postoperative complications.

Methods

Patient data from the German Society for General and Visceral Surgery (StuDoQ) registry from 2010 to 2017 were analysed. Univariable and multivariable analyses were performed. The primary endpoint was anastomotic leakage; secondary endpoints were postoperative ileus, complications and length of postoperative hospital stay (LOS).

Results

A total of 4062 patients who had undergone open right hemicolectomy for colonic cancer were analysed. All patients had an ileocolic anastomosis, 2742 handsewn and 1320 stapled. Baseline characteristics were similar. No significant differences were identified in anastomotic leakage, postoperative ileus, reoperation rate, surgical‐site infection, LOS or death. The stapled group had a significantly shorter duration of surgery and fewer Clavien–Dindo grade I–II complications. In multivariable logistic regression analysis, ASA grade and BMI were found to be significantly associated with postoperative complications such as anastomotic leakage, postoperative ileus and reoperation rate.

Conclusion

Handsewn and stapled ileocolic anastomoses for open right‐sided colonic cancer resections are equally safe. Stapler use was associated with reduced duration of surgery and significantly fewer minor complications.

Sub-differentiating equivocal PI-RADS-3 lesions in multiparametric magnetic resonance imaging of the prostate to improve cancer detection

PURPOSE

To evaluate sub-differentiation of PI-RADS-3 prostate lesions using pre-defined T2- and diffusion-weighted (DWI) MRI criteria, to aid the biopsy decision process.

METHODS

143 patients with PIRADS-3 index lesions on MRI underwent targeted transperineal-MR/US fusion biopsy. Radiologists with 2 and 7-years experience performed blinded retrospective second-reads using set criteria and assigned biopsy recommendations. Inter-reader agreement, Gleason score (GS), positive (PPV) predictive values (±95% confidence intervals) were calculated and compared by Fisher's exact test with Bonferroni-Hom correction.

RESULTS

43% (61/143) patients had GS 6-10 and 21% (30/143) GS≥3+4 cancer. For peripheral zone lesions, significant differences in any cancer detection were found for shape (0.26±0.13 geographical vs. 0.69±0.23 rounded; p=0.0055) and ADC (mild 0.21±0.12 vs marked 0.81±0.19; p=0.0001). For transition zone, significantly increased cancer detection was shown for location (anterior 0.63±0.15 vs. mid/posterior 0.31±0.14; p=0.0048), border (pseudo-capsule 0.32±0.14 vs. ill-defined 0.61±0.15; p=0.0092), and ADC (mild 0.35±0.12 vs marked restriction 0.68±0.17; p=0.0057). Biopsy recommendations had 62% inter-reader agreement (89/143). Experienced reader PPVs were significantly higher for any cancer with "biopsy-recommended" 0.61±0.11 vs. "no biopsy" 0.21±0.10 (p=0.0001), and for GS 7-10 cancers: 0.32±0.10 vs. 0.08±0.07, respectively (p=0.0003).

CONCLUSION

Identification of certain objective imaging criteria as well as a subjective biopsy recommendation from an experienced radiologist can help to increase the predictive value of equivocal prostate lesions and inform the decision making process of whether or not to biopsy.

The Prostate Health Index adds predictive value to multi-parametric MRI in detecting significant prostate cancers in a repeat biopsy population

Both multi-parametric MRI (mpMRI) and the Prostate Health Index (PHI) have shown promise in predicting a positive biopsy in men with suspected prostate cancer. Here we investigated the value of combining both tests in men requiring a repeat biopsy. PHI scores were measured in men undergoing re-biopsy with an mpMRI image-guided transperineal approach (n = 279, 94 with negative mpMRIs). The PHI was assessed for ability to add value to mpMRI in predicting all or only significant cancers (Gleason ≥7). In this study adding PHI to mpMRI improved overall and significant cancer prediction (AUC 0.71 and 0.75) compared to mpMRI + PSA alone (AUC 0.64 and 0.69 respectively). At a threshold of ≥35, PHI + mpMRI demonstrated a NPV of 0.97 for excluding significant tumours. In mpMRI negative men, the PHI again improved prediction of significant cancers; AUC 0.76 vs 0.63 (mpMRI + PSA). Using a PHI≥35, only 1/21 significant cancers was missed and 31/73 (42%) men potentially spared a re-biopsy (NPV of 0.97, sensitivity 0.95). Decision curve analysis demonstrated clinically relevant utility of the PHI across threshold probabilities of 5-30%. In summary, the PHI adds predictive performance to image-guided detection of clinically significant cancers and has particular value in determining re-biopsy need in men with a negative mpMRI.

Utilization of multiparametric prostate magnetic resonance imaging in clinical practice and focal therapy: report from a Delphi consensus project

Purpose

To codify the use of multiparametric magnetic resonance imaging (mpMRI) for the interrogation of prostate neoplasia (PCa) in clinical practice and focal therapy (FT).

Methods

An international collaborative consensus project was undertaken using the Delphi method among experts in the field of PCa. An online questionnaire was presented in three consecutive rounds and modified each round based on the comments provided by the experts. Subsequently, a face-to-face meeting was held to discuss and finalize the consensus results.

Results

mpMRI should be performed in patients with prior negative biopsies if clinical suspicion remains, but not instead of the PSA test, nor as a stand-alone diagnostic tool or mpMRI-targeted biopsies only. It is not recommended to use a 1.5 Tesla MRI scanner without an endorectal or pelvic phased-array coil. mpMRI should be performed following standard biopsy-based PCa diagnosis in both the planning and follow-up of FT. If a lesion is seen, MRI-TRUS fusion biopsies should be performed for FT planning. Systematic biopsies are still required for FT planning in biopsy-naïve patients and for patients with residual PCa after FT. Standard repeat biopsies should be taken during the follow-up of FT. The final decision to perform FT should be based on histopathology. However, these consensus statements may differ for expert centers versus non-expert centers.

Conclusions

The mpMRI is an important tool for characterizing and targeting PCa in clinical practice and FT. Standardization of acquisition and reading should be the main priority to guarantee consistent mpMRI quality throughout the urological community.

Electronic supplementary material

The online version of this article (doi:10.1007/s00345-016-1932-1) contains supplementary material, which is available to authorized users.

Standardization of definitions in focal therapy of prostate cancer: report from a Delphi consensus project

PURPOSE

To reach standardized terminology in focal therapy (FT) for prostate cancer (PCa).

METHODS

A four-stage modified Delphi consensus project was undertaken among a panel of international experts in the field of FT for PCa. Data on terminology in FT was collected from the panel by three rounds of online questionnaires. During a face-to-face meeting on June 21, 2015, attended by 38 experts, all data from the online rounds were reviewed and recommendations for definitions were formulated.

RESULTS

Consensus was attained on 23 of 27 topics; Targeted FT was defined as a lesion-based treatment strategy, treating all identified significant cancer foci; FT was generically defined as an anatomy-based (zonal) treatment strategy. Treatment failure due to the ablative energy inadequately destroying treated tissue is defined as ablation failure. In targeting failure the energy is not adequately applied to the tumor spatially and selection failure occurs when a patient was wrongfully selected for FT. No definition of biochemical recurrence can be recommended based on the current data. Important definitions for outcome measures are potency (minimum IIEF-5 score of 21), incontinence (new need for pads or leakage) and deterioration in urinary function (increase in IPSS >5 points). No agreement on the best quality of life tool was established, but UCLA-EPIC and EORTC-QLQ-30 were most commonly supported by the experts. A complete overview of statements is presented in the text.

CONCLUSION

Focal therapy is an emerging field of PCa therapeutics. Standardization of definitions helps to create comparable research results and facilitate clear communication in clinical practice.

Development of a novel injectable drug delivery system for subconjunctival glaucoma treatment

In this study we present the development of an injectable polymeric drug delivery system for subconjunctival treatment of primary open angle glaucoma. The system consists of hyaluronic acid sodium salt (HA), which is commonly used in ophthalmology in anterior segment surgery, and an isocyanate-functionalized 1,2-ethylene glycol bis(dilactic acid) (ELA-NCO). The polymer mixtures with different ratios of HA to ELA-NCO (1/1, 1/4, and 1/10 (v/v)) were investigated for biocompatibility, degradation behavior and applicability as a sustained release system. For the latter, the lipophilic latanoprost ester pro-drug (LA) was incorporated into the HA/ELA-NCO system. In vitro, a sustained LA release over a period of about 60days was achieved. In cell culture experiments, the HA/ELA-NCO (1/1, (v/v)) system was proven to be biocompatible for human and rabbit Tenon's fibroblasts. Examination of in vitro degradation behavior revealed a total mass loss of more than 60% during the observation period of 26weeks. In vivo, LA was continuously released for 152days into rabbit aqueous humor and serum. Histological investigations revealed a marked leuko-lymphocytic infiltration soon after subconjunctival injection. Thereafter, the initial tissue reaction declined concomitantly with a continuous degradation of the polymer, which was completed after 10months. Our study demonstrates the suitability of the polymer resulting from the reaction of HA with ELA-NCO as an injectable local drug delivery system for glaucoma therapy, combining biocompatibility and biodegradability with prolonged drug release.

A prospective 10-year study of metal ceramic single crowns and fixed dental prosthesis retainers in private practice settings

STATEMENT OF PROBLEM

Metal ceramic restorations are widely used in prosthodontics, but long-term data on their clinical performance in private practice settings based on prospective trials are sparse.

PURPOSE

This clinical trial was designed to provide realistic long-term survival rates for different outcomes related to tooth loss, crown loss, and metal ceramic defect.

MATERIAL AND METHODS

Ninety-five participants were provided with 190 noble metal ceramic single crowns and 138 participants with 276 fixed dental prosthesis retainer crowns on vital posterior teeth. Follow-up examinations were scheduled 2 weeks after insertion, annually up to 8 years, and after 10 years. Kaplan-Meier survival analyses, Mantel-Cox logrank tests, and Cox regression analyses were conducted.

RESULTS

Because of variations in the time of the last examinations, the maximum observation period was 12.1 years. For the primary outcome 'loss of crown or tooth', the Kaplan-Meier survival rate was 94.3% ±1.8% (standard error) at 8.0 years (last outcome event) for single crowns and 94.4% ±1.5% at 11.0 years for fixed dental prosthesis retainer crowns. The difference between the survival functions was not significant (P>.05). For the secondary outcome 'metal ceramic defect', the survival rate was 88.8% ±3.2% at 11.0 years for single crowns and 81.7% ±3.5% at 11.0 years for fixed dental prosthesis retainer crowns. In Cox regression models, the only significant covariates for the outcome event 'metal ceramic defect' were bruxism in the medical history (single crowns) and signs and symptoms of bruxism (fixed dental prosthesis retainer crowns) with hazard ratios of 3.065 (95% CI 1.063 - 8.832) and 2.554 (95% CI 1.307 - 4.992).

CONCLUSIONS

Metal ceramic crowns provided in private practice settings show good longevity. Bruxism appears to indicate a risk for metal ceramic defects.

Ocular fibroblast types differ in their mRNA profiles--implications for fibrosis prevention after aqueous shunt implantation

PURPOSE

For an aqueous shunt draining from the anterior chamber into the choroidal space, fibroblasts from the choroidea and/or the sclera are most likely responsible for a fibrotic response around the outflow region of such a shunt. The prevention of fibrosis should extend the operating life of the shunt. A detailed characterization of fibroblasts derived from choroidea and sclera should provide information about whether a fibrosis reaction can be inhibited by cell type-specific agents.

METHODS

We generated mRNA profiles of fibroblasts from the choroidea, sclera, and Tenon's space by gene array hybridization to provide a basis on which to search for potential pharmacological targets for fibrosis prevention. Hybridization data were analyzed by the Rosetta Resolver system and Limma to obtain mRNA profiles of the three fibroblast types.

RESULTS

The three fibroblast types investigated shared fibroblast-specific gene expression patterns concerning extracellular matrix proteins as collagens and fibronectin, but also showed distinct mRNA patterns.

CONCLUSIONS

Individual mRNA species overexpressed in one of the fibroblast types might serve as markers for the identification of the fibroblast type in histological analyses. Future in-depth analyses of the gene expression patterns might help identify pharmacological targets for fibrosis prevention.

Light inhibits spore germination through phytochrome in Aspergillus nidulans

Aspergillus nidulans responds to light in several aspects. The balance between sexual and asexual development as well as the amount of secondary metabolites produced is controlled by light. Here, we show that germination is largely delayed by blue (450 nm), red (700 nm), and far-red light (740 nm). The largest effect was observed with far-red light. Whereas 60 % of the conidia produced a germ tube after 20 h in the dark, less than 5 % of the conidia germinated under far-red light conditions. Because swelling of conidia was not affected, light appears to act at the stage of germ-tube formation. In the absence of nutrients, far-red light even inhibited swelling of conidia, whereas in the dark, conidia did swell and germinated after prolonged incubation. The blue-light signaling components, LreA (WC-1) and LreB (WC-2), and also the cryptochrome/photolyase CryA were not required for germination inhibition. However, in the phytochrome mutant, ∆fphA, the germination delay was released, but germination was delayed in the dark in comparison to wild type. This suggests a novel function of phytochrome as far-red light sensor and as activator of polarized growth in the dark.

New concepts for glaucoma implants--controlled aqueous humor drainage, encapsulation prevention and local drug delivery

Glaucoma is a common cause of blindness in industrialized countries and is the most frequent cause of irreversible blindness worldwide. Since raised intraocular pressure (IOP) has been implicated as the major risk factor, the main goal of all glaucoma treatment is to reduce IOP sufficiently to prevent continuous irreversible retinal ganglion cell damage and progression of visual field loss. Pharmacological reduction of IOP is first-line therapy, followed by laser treatment of the trabecular meshwork and filtering glaucoma surgery, and cyclophotocoagulation of the ciliary body or allogenic implants. The most important glaucoma implants are presented (MOLTENO, AHMED, BAERVELDT, KRUPIN) together with more recent developments (Ex-Press, Eyepass, iStent, Gold micro shunt). Drainage into the suprachoroidal space is a promising option, but is also limited by scarring of the new created outflow route due to proliferation and adhesion of fibroblasts. A deeper understanding of fibroblasts in the related eye compartments is required. Characterization of scleral, choroidal, and, as a reference, Tenon fibroblast subtypes, is possible based on gene expression patterns. Alongside mitomycin C and 5-fluorouracil, newer drugs to prevent fibrosis have been proposed, offering effects that are more specific and more physiological. Effectors involved in wound healing phases and signaling pathways are potential targets for pharmaceutical intervention. Downregulation of growth factors like TGF-ß and their downstream effectors may suppress proliferation and differentiation of fibroblasts, extracellular matrix deposition, wound contraction, and neovascularization. Furthermore, current approaches to local drug delivery in glaucoma implant technology are briefly summarized.

Different fibroblast subpopulations of the eye: a therapeutic target to prevent postoperative fibrosis in glaucoma therapy

The aim of this study is the characterization of fibroblasts mainly responsible for fibrosis processes associated with trabeculectomy or microstent implantation for glaucoma therapy. Therefore we isolated human primary fibroblasts from choroidea, sclera, Tenon capsule, and orbital fat tissues. These fibroblast subpopulations were analysed in vitro for expression of the extracellular matrix components which are responsible for postoperative scarring in glaucoma therapy. For scarring the proteins of the collagen family are predominant and so we focused on the expression of collagen I, collagen III and collagen VI in every fibroblast subpopulation. Also, the extracellular matrix protein fibronectin which crosslinks collagen fibres or other extracellular matrix components and cell surfaces, was analyzed. Collagen I, III and VI were prominent in every fibroblast subpopulation. The highest amounts of collagen III were found in hCF and hOF, whereas the signal in hSF and hTF was negligible. Additionally, there is a link between scarring processes and proliferating potential of fibroblasts, in case of microstent implantation triggered through the infiltration of inflammatory cells. Thus we analyzed fibroblast subpopulations for the presence of TGF-β1 which is one of the most important cytokines involved in proliferation processes. TGF-β1 was prominent in all fibroblast subpopulations with lowest expression in hCF cultures. To prevent postoperative fibroblast proliferation we analyzed in vitro the proliferation-inhibitors paclitaxel and mitomycin C which are potential candidates in drug eluting drainage systems on ocular fibroblast subpopulations. These inhibitors arrest fibroblast proliferation and viability, being, however, not very specific and have a cytotoxic potential also on healthy tissues surrounding the microstent outflow area. Significant differences in protein synthesis of fibroblasts subpopulations which could be specific targets for inhibition may help to find out fibroblast specific inhibitors to prevent postoperative scarring and could prevent patients from secondary surgery after microstent implantation.

Fungi, hidden in soil or up in the air: light makes a difference

Light is one of the most important environmental factors for orientation of almost all organisms on Earth. Whereas light sensing is of crucial importance in plants to optimize light-dependent energy conservation, in nonphotosynthetic organisms, the synchronization of biological clocks to the length of a day is an important function. Filamentous fungi may use the light signal as an indicator for the exposure of hyphae to air and adapt their physiology to this situation or induce morphogenetic pathways. Although a yes/no decision appears to be sufficient for the light-sensing function in fungi, most species apply a number of different, wavelength-specific receptors. The core of all receptor types is a chromophore, a low-molecular-weight organic molecule, such as flavin, retinal, or linear tetrapyrrols for blue-, green-, or red-light sensing, respectively. Whereas the blue-light response in fungi is one of the best-studied light responses, all other light-sensing mechanisms are less well studied or largely unknown. The discovery of phytochrome in bacteria and fungi in recent years not only advanced the scientific field significantly, but also had great impact on our view of the evolution of phytochrome-like photoreceptors.

Hexaminolevulinate-induced fluorescence colonoscopy versus white light endoscopy for diagnosis of neoplastic lesions in the colon

BACKGROUND AND STUDY AIMS

To compare the rate of detection of colorectal neoplastic lesions using the selective photosensitizer precursor hexaminolevulinate (HAL) combined with a new fluorescence video endoscope system against that of standard white light endoscopy, and secondarily, to evaluate the safety profile of HAL-induced fluorescence colonoscopy.

PATIENTS AND METHODS

This prospective phase II clinical pilot study from two hospital study centers included 25 patients with known or highly suspected colorectal neoplasia. They underwent sensitization with locally applied 500 ml HAL enemas at a concentration of 1.6 mmol/L. At 60 minutes after enteral HAL administration, fluorescence imaging was done using a special light source capable of delivering either white light or blue excitation light. Red fluorescence induced by illumination with blue light was detected via a prototype fluorescence video colonoscope. Biopsies were taken from suspicious areas found with white or blue light.

RESULTS

Using histology as the gold standard, 55 / 93 of neoplastic lesions were detected with white light endoscopy, 53 / 93 with both white and blue light, 38 / 93 with blue light and second-pass white light, and 27/93 with blue light only. Of all neoplastic lesions, 91 / 93 revealed red fluorescence under fluorescence imaging ( P < 0.0001). Fluorescence mode showed 38.7 % (36 / 93) more neoplasms than did white light endoscopy. An isolated slight elevation of bilirubin, by a factor of 1.5, was noted after the administration of HAL.

CONCLUSIONS

Administration of HAL as enema induces selective lesion fluorescence and increases lesion detection rate in patients with colorectal neoplasia, especially of flat, nonvisible adenomas.

Effects of receptor-mediated endocytosis and tubular protein composition on volume retention in experimental glomerulonephritis

Human glomerulonephritis (GN) is characterized by sustained proteinuria, sodium retention, hypertension, and edema formation. Increasing quantities of filtered protein enter the renal tubule, where they may alter epithelial transport functions. Exaggerated endocytosis and consequent protein overload may affect proximal tubules, but intrinsic malfunction of distal epithelia has also been reported. A straightforward assignment to a particular tubule segment causing salt retention in GN is still controversial. We hypothesized that 1) trafficking and surface expression of major transporters and channels involved in volume regulation were altered in GN, and 2) proximal tubular endocytosis may influence locally as well as downstream expressed tubular transporters and channels. Effects of anti-glomerular basement membrane GN were studied in controls and megalin-deficient mice with blunted proximal endocytosis. Mice displayed salt retention and elevated systolic blood pressure when proteinuria had reached 10-15 mg/24 h. Surface expression of proximal Na(+)-coupled transporters and water channels was in part [Na(+)-P(i) cotransporter IIa (NaPi-IIa) and aquaporin-1 (AQP1)] increased by megalin deficiency alone, but unchanged (Na(+)/H(+) exchanger 3) or reduced (NaPi-IIa and AQP1) in GN irrespective of the endocytosis defect. In distal epithelia, significant increases in proteolytic cleavage products of alpha-epithelial Na(+) channel (ENaC) and gamma-ENaC were observed, suggesting enhanced tubular sodium reabsorption. The effects of glomerular proteinuria dominated over those of blunted proximal endocytosis in contributing to ENaC cleavage. Our data indicate that ENaC-mediated sodium entry may be the rate-limiting step in proteinuric sodium retention. Enhanced proteolytic cleavage of ENaC points to a novel mechanism of channel activation which may involve the action of filtered plasma proteases.

Functional and physical interaction of blue- and red-light sensors in Aspergillus nidulans

Light sensing is very important for organisms in all biological kingdoms to adapt to changing environmental conditions. It was discovered recently that plant-like phytochrome is involved in light sensing in the filamentous fungus Aspergillus nidulans[1]. Here, we show that phytochrome (FphA) is part of a protein complex containing LreA (WC-1) and LreB (WC-2) [2, 3], two central components of the Neurospora crassa blue-light-sensing system. We found that FphA represses sexual development and mycotoxin formation, whereas LreA and LreB stimulate both. Surprisingly, FphA interacted with LreB and with VeA, another regulator involved in light sensing and mycotoxin biosynthesis. LreB also interacted with LreA. All protein interactions occurred in the nucleus, despite cytoplasmic subfractions of the proteins. Whereas the FphA-VeA interaction was dependent on the presence of the linear tetrapyrrole in FphA, the interaction between FphA and LreB was chromophore independent. These results suggest that morphological and physiological differentiations in A. nidulans are mediated through a network consisting of FphA, LreA, LreB, and VeA acting in a large protein complex in the nucleus, sensing red and blue light.

Early detection of premalignant conditions in the colon by fluorescence endoscopy using local sensitization with hexaminolevulinate

BACKGROUND AND STUDY AIMS

We aimed to determine the feasibility of obtaining selective fluorescence of precancerous/cancerous lesions in the colon with a new fluorescence video endoscope system in combination with the selective photosensitizer precursor hexaminolevulinate (HAL), and to carry out a dose-finding study with evaluation of the optimal dose and application time.

PATIENTS AND METHODS

12 patients with colorectal lesions underwent sensitization with locally applied HAL enemas in two concentrations (0.8 mmol and 1.6 mmol). The examination was conducted either 30 or 60 minutes after rectal administration of the sensitizer, using a special light source capable of delivering either white or blue excitation light. Red fluorescence induced by illumination with blue light was detected via a prototype fluorescence video colonoscope. Biopsies were taken from suspicious areas found with white or blue light. Corresponding endoscopic, fluorescence, and microscopic findings were compared.

RESULTS

Using histological findings as the gold standard, 52/53 of the premalignant/malignant lesions showed red fluorescence under the photodynamic diagnosis (PDD) examination; 38/53 were detected with white-light endoscopy. The PDD mode showed 28 % more polyps than did white-light endoscopic imaging. The greatest fluorescence intensity in precancerous lesions was found with retention for 60 minutes of 500 ml of 1.6 mmol HAL.

CONCLUSIONS

Administration of HAL enema induces selective lesion fluorescence and increases the lesion detection rate in patients with colorectal adenoma and early carcinoma.

Seeing the rainbow: light sensing in fungi

Light is essential for photosynthetic organisms, but also serves as an important environmental cue for non-photosynthetic species; thus, light sensing is evolutionarily conserved throughout the kingdoms, from archaea and fungi to humans. Light sensors are chromoproteins, the low-molecular weight compound of which absorbs specific wavelengths and induces a reaction from the protein. In fungi, three light-sensing systems have been described at the molecular level. Blue-light sensing is achieved by a flavin-based photoreceptor, which itself acts as a transcription factor, and red-light sensing is achieved by a phytochrome, a molecule until recently thought to be confined to plants. A retinal-based opsin-system was discovered recently, although a biological function remains to be determined. The challenge for future research will be the identification of further components of signalling cascades, the identification of light-regulated genes and the unravelling of possible functional interplays between the different light control systems.

Metal-ceramic failure in noble metal crowns: 7-year results of a prospective clinical trial in private practices

PURPOSE

The aim of this study was to evaluate the clinical performance of metal-ceramic crowns placed in 10 private practices.

MATERIALS AND METHODS

In this prospective clinical trial, 95 patients were provided with 190 noble-metal metal-ceramic single crowns.

RESULTS

The 7-year survival rates of the crowns were 95.5% (target event: any removal), 99.5% (target event: removal because of defective veneer), and 92.4% (target event: metal-ceramic complication of any kind). No significant explanatory variables for metal-ceramic complications could be detected by bivariate and multivariate testing. The consequences resulting from metal-ceramic defects were of minor clinical significance in most cases.

CONCLUSION

The findings support previous claims that metal-ceramic restorations perform very well clinically, including in practices outside academic environments.

The Charlson comorbidity score: a superior comorbidity assessment tool for the prostate cancer multidisciplinary meeting

INTRODUCTION

Multidisciplinary team (MDT) meetings use precise prognostic factors to select treatment options for patients with prostate cancer. Comorbidity is judged subjectively. Recent publications favour the Charlson comorbidity score (CS) for the use in the management of prostate cancer. We assess the feasibility of using the CS by our MDT in planning the treatment of patients with prostate cancer.

PATIENTS AND METHODS

Patients from the histopathology database aged less than 75 years and with a diagnosis of localized prostate cancer between 1993 and 1995 were included in a notes audit. A second group consisted of patients recommended for curative treatment for localized prostate cancer by the local MDT in 2004. Data on comorbidity, prostatic malignancy and survival up to 10 years was collected. The prognostic accuracy of the CS was assessed for those patients offered radical treatment between 1993 and 1995.

RESULTS

Of 1043 patients initially assessed, 37 patients with localized prostate cancer were identified. Using Cox regression, we found the CS to be a statistically significant predictor of survival, following radical treatment for localized prostate cancer (P=0.005). Current practice in 2004 (56 patients) shows a mean (range) Charlson probability of 10-year survival for radical prostatectomy of 0.823 (0.592-0.923) and for radical radiotherapy of 0.653 (0.07-0.936).

CONCLUSIONS

Our results support the findings of recent research. We also found the CS easy to calculate and therefore feasible to use in our MDT setting. We propose the introduction of the Charlson score by prostate cancer MDTs to assess age and comorbidity.

Measurement of immunoglobulins in seminal fluid with modified nephelometry--an alternative diagnostic tool for chronic prostatitis

The objectives of the study were to investigate the feasibility of the modified nephelometry technique to measure immunoglobulin G and A in seminal fluid and to evaluate their use in diagnosis and follow-up of chronic prostatitis.IgG and A in seminal fluid of healthy individuals (HI) and chronic prostatitis patients (CP) were measured with modified nephelometry. The literature values were confirmed. IgG reflects the long-term healing process of chronic prostatitis. IgA was significantly increased in patients with exacerbation of the disease. Nephelometry proves to be a reliable and inexpensive test to obtain IgG and IgA in seminal fluid. IgG and IgA are useful as objective parameters to confirm subjective symptom scores in a chronic prostatitis research setting.

Improving the effectiveness of the emergency management of renal colic in a district general hospital: a completed audit cycle

OBJECTIVES

To assess the current practice of emergency management of renal colic in a district hospital, review literature, implement new guidelines, and assess them.

METHODS

Data were collected about the use of analgesia, waiting time for intravenous urography (IVU), and admission status of patients presenting to the hospital with symptoms of renal colic over the period of three months. A literature search into the use of analgesia, imaging, and treatment was performed. Members of the involved departments were consulted and new guidelines developed and implemented. This was followed by further data collection over three months.

RESULTS

Seven of 14 patients were admitted. Five to wait for their IVU. Their average waiting time was 12.3 (SD 2.2) hours. Mainly intramuscular opioid analgesia was used. Literature recommended the use of diclofenac. Although computed tomography was favoured it was decided to continue to use IVU because of circumstances within the hospital. The literature recommended a cut off between conservative and surgical treatment at a calculus size of >4 mm. Existing policies of the relevant departments were obeyed and a training system for the junior doctors was introduced. Emergency department staff were encouraged to perform 3-film IVUs. After this, of 5 of 19 patients were admitted, only one of those to wait for an IVU. The average waiting time for an IVU was 4.1 (SD 0.96) hours. Rectal diclofenac was noted to be the drug of choice.

CONCLUSION

Coordination of efforts, interdepartmental communication, and a practical application of available literature has resulted in a significant improvement of effectiveness without affecting medical standards, workload, or resources. Accident and emergency senior house officers felt highly satisfied at being able to complete management from presentation to diagnosis and treatment. Interdisciplinary communication has to be continued to maintain smooth operation of the guidelines.

Analysis of pregnancy and other factors on detection of human papilloma virus (HPV) infection using weighted estimating equations for follow-up data

Generalized estimating equations have been well established to draw inference for the marginal mean from follow-up data. Many studies suffer from missing data that may result in biased parameter estimates if the data are not missing completely at random. Robins and co-workers proposed using weighted estimating equations (WEE) in estimating the mean structure if drop-out occurs missing at random. We illustrate the differences between the WEE and the commonly applied available case analysis in a simulation study. We apply the WEE and reanalyse data of a longitudinal study of pregnancy and human papilloma virus (HPV) infection. We estimate the response probabilities and demonstrate that the data are not missing completely at random. Upon use of the WEE, we are able to show that pregnant women have an increased odds for an HPV infection compared with non-pregnant women after delivery (p=0.027). We conclude that the WEE are useful for dealing with monotone missing data due to drop-outs in follow-up data.

Effect of posterior crown margin placement on gingival health

STATEMENT OF PROBLEM

The clinical impact of posterior crown margin placement on gingival health has not been thoroughly quantified.

PURPOSE

This study evaluated the effect of posterior crown margin placement with multivariate analysis.

MATERIAL AND METHODS

Ten general dentists reviewed 240 patients with 480 metal-ceramic crowns in a prospective clinical trial. The alloy was randomly selected from 2 high gold, 1 low gold, and 1 palladium alloy. Variables were the alloy used, oral hygiene index score before treatment, location of crown margins at baseline, and plaque index and sulcus bleeding index scores recorded for restored and control teeth after 1 year. The effect of crown margin placement on sulcular bleeding and plaque accumulation was analyzed with regression models (P<.05).

RESULTS

The probability of plaque at 1 year increased with increasing oral hygiene index score before treatment. The lingual surfaces demonstrated the highest probability of plaque. The risk of bleeding at intrasulcular posterior crown margins was approximately twice that at supragingival margins. Poor oral hygiene before treatment and plaque also were associated with sulcular bleeding. Facial sites exhibited a lower probability of sulcular bleeding than lingual surfaces. Type of alloy did not influence sulcular bleeding.

CONCLUSION

In this study, placement of crown margins was one of several parameters that affected gingival health.

Bone metabolism during the perimenopausal transition: a prospective study

OBJECTIVE

Changes in biochemical markers of bone formation and resorption were followed over the course of 1 year in premenopausal, perimenopausal and early postmenopausal women.

METHODS

Sixty-four subjects were analyzed, grouped according to their menstrual pattern, menopausal complaints and endocrinological parameters to be premenopausal (n=20), perimenopausal (n=24) or early postmenopausal (n=20). The parameters studied at four visits during the 12-month study period were the urinary pyridinium cross-links pyridinoline (PYD) and deoxypyridinoline (DPD), and N-terminal telopeptide (NTX) as bone resorption markers, as well as osteocalcin (OC) and bone-specific alkaline phosphatase (BAP) in serum, representing bone formation. The longitudinal changes over time as well as intergroup differences were analyzed using generalized estimating equations (GEE) in connection with Wald statistics.

RESULTS

Over the course of 1 year BAP levels decreased in the late premenopausal group (P<0.05). The perimenopausal group exhibited significant changes of PYD, DPD and OC (P<0.01), NTX levels were higher than in premenopause. Postmenopausal subjects had elevated NTX values, while PYD and DPD levels remained close to the perimenopausal range. Only for OC a time effect was seen during postmenopause.

CONCLUSIONS

Changes in bone turnover already begin in late premenopause, when decreased bone formation may precede increased bone resorption. The rise of NTX from late premenopause through early postmenopause indicates diagnostic sensitivity of this parameter to changes in bone metabolism induced by estrogen withdrawal. PYD and DPD do not follow this pattern, but change significantly with time during perimenopause to then remain largely unchanged in early postmenopause.

Familial associations of lipid profiles: a generalized estimating equations approach

Elevated plasma levels of apolipoproteins A1 (apoA1) and B (apoB) are important protective factors and risk factors, respectively, for atherosclerosis and coronary heart disease. It is well known that both apoA1 and apoB reveal strong familial aggregation. Our goal was to investigate whether exogenous variables influence these associations. We used marginal regression models for the mean and association structure (generalized estimating equations 2; GEE2) to analyse data from 1435 family members within 469 families of different sizes included in the Donolo-Tel Aviv Three-Generation Offspring Study. The usual robust variance matrix was approximated by extensions of jack-knife estimators of variance to GEE2 models. Estimation of standard errors in models with quite complex correlation structures was possible using this approach. All analyses were easily carried out using a menu-driven stand-alone software tool for marginal regression modelling. We demonstrate that a variety of hypotheses can be tested using Wald statistics by modelling regression matrices for the association structure. We show that correlation for apoB between parent-offspring pairs increased with decreasing age difference and that pairs with individuals of the same gender had more similar apoA1 levels than individuals of different gender. Associations between different relative pairs did not all agree with those expected from differences in kinship coefficients. The analysis using GEE2 models revealed structures that would not have been detected by other models and should therefore be used in addition to traditional approaches of analysing family data. GEE2 should be considered a standard method for the investigation of familial aggregation.

Fibrin specificity and procoagulant effect related to the kallikrein-contact phase system and to plasmin generation with double-bolus reteplase and front-loaded alteplase thrombolysis in acute myocardial infarction

This study was undertaken to compare the effects of reteplase and alteplase regimens on hemostasis and fibrinolysis in acute myocardial infarction (AMI). Thrombolytic treatment in patients with AMI is hampered by paradoxical procoagulant effects that favor early reocclusion. In vivo data comparing this effect and the fibrin specificity of double-bolus reteplase and front-loaded alteplase regimens are not available. In a prospective, randomized study, 50 patients with AMI were either treated with double bolus (10 + 10 U) reteplase or with front-loaded alteplase (up to 100 mg) within 6 hours of symptom onset. Thirty apparently healthy persons served as controls. Molecular markers of coagulation and fibrinolysis were serially examined for up to 5 days. Paradoxical thrombin activation at 3 hours after initiation of therapy was comparable between reteplase and alteplase. Reteplase (65 +/- 5 U/L) and alteplase (72 +/- 8 U/L) caused significantly elevated kallikrein activity at 3 hours after adminstration (p <0.01 vs controls 30 +/- 1 U/L). Fibrin specificity was less for reteplase (p <0.05) with a decrease in fibrinogen at 3 hours to 122 +/- 27 mg/dl versus 224 +/- 28 mg/dl for alteplase (p <0.01 and p <0.05 vs controls). D-Dimer levels at 3 hours were higher (p <0.05) after reteplase (5,459 +/- 611 ng/ml) versus alteplase (3,445 +/- 679 ng/ml) (both p <0.01 vs controls 243 +/- 17 ng/ml). Plasmin generation (plasmin-antiplasmin complexes) was significantly (p <0.01) increased at 3 hours with both regimens to 27,079 +/- 3,964 microg/L (reteplase) and 19,522 +/- 2,381 microg/L (alteplase). The data from 3 hours after start of thrombolytic therapy proved less marked fibrin specificity of the reteplase regimen (in vivo) compared with front-loaded alteplase. Both regimens have a moderate procoagulant effect without differences in activation of the kallikrein system.