ß-Hydroxybutyrate Improves Mitochondrial Function After Transient Ischemia in the Mouse.

ß-Hydroxybutyrate (BHB) is a ketone body formed in high amounts during lipolysis and fasting. Ketone bodies and the ketogenic diet were suggested as neuroprotective agents in neurodegenerative disease. In the present work, we induced transient ischemia in mouse brain by unilaterally occluding the middle cerebral artery for 90 min. BHB (30 mg/kg), given immediately after reperfusion, significantly improved the neurological score determined after 24 h. In isolated mitochondria from mouse brain, oxygen consumption by the complexes I, II and IV was reduced immediately after ischemia but recovered slowly over 1 week. The single acute BHB administration after reperfusion improved complex I and II activity after 24 h while no significant effects were seen at later time points. After 24 h, plasma and brain BHB concentrations were strongly increased while mitochondrial intermediates (citrate, succinate) were unchanged in brain tissue. Our data suggest that a single administration of BHB may improve mitochondrial respiration for 1-2 days but not for later time points. Endogenous BHB formation seems to complement the effects of exogenous BHB administration.

Insights into Nitrous Oxide Mitigation Strategies in Wastewater Treatment and Challenges for Wider Implementation.

Nitrous oxide (N2O) emissions account for the majority of the carbon footprint of wastewater treatment plants (WWTPs). Many N2O mitigation strategies have since been developed while a holistic view is still missing. This article reviews the state-of-the-art of N2O mitigation studies in wastewater treatment. Through analyzing existing studies, this article presents the essential knowledge to guide N2O mitigations, and the logics behind mitigation strategies. In practice, mitigations are mainly carried out by aeration control, feed scheme optimization, and process optimization. Despite increasingly more studies, real implementation remains rare, which is a combined result of unclear climate change policies/incentives, as well as technical challenges. Five critical technical challenges, as well as opportunities, of N2O mitigations were identified. It is proposed that (i) quantification methods for overall N2O emissions and pathway contributions need improvement; (ii) a reliable while straightforward mathematical model is required to quantify benefits and compare mitigation strategies; (iii) tailored risk assessment needs to be conducted for WWTPs, in which more long-term full-scale trials of N2O mitigation are urgently needed to enable robust assessments of the resulting operational costs and impact on nutrient removal performance; (iv) current mitigation strategies focus on centralized WWTPs, more investigations are warranted for decentralised systems, especially decentralized activated sludge WWTPs; and (v) N2O may be mitigated by adopting novel strategies promoting N2O reduction denitrification or microorganisms that emit less N2O. Overall, we conclude N2O mitigation research is reaching a maturity while challenges still exist for a wider implementation, especially in relation to the reliability of N2O mitigation strategies and potential risks to nutrient removal performances of WWTPs.

Fungal Infection in an Exenterated Orbit.

A 48-year-old man presented with an Aspergillus fumigatus complex infection of an exenterated orbit. The OS had been exenterated 7 months ago, together with total parotidectomy and neck dissection followed by irradiation due to a massive squamous cell carcinoma with orbital invasion and lymphatic metastasis. The patient was under permanent immunosuppression with oral prednisone and tacrolimus due to a kidney transplantation 5 years ago. The infected skin of the exenterated orbit was cleared using forceps. MRI ruled out any bone infiltration. After systemic treatment with oral voriconazole and topical therapy with bifonazole ointment for 6 weeks, the patient recovered completely.

Towards a standardization of biomethane potential tests: a commentary.

Inter-laboratory reproducibility of biomethane potential (BMP) is dismal, with differences in BMP values for the same sample exceeding a factor of two in some cases. A large group of BMP researchers directly addressed this problem during a workshop held in Leysin, Switzerland, in June 2015. The workshop resulted in a new set of guidelines for BMP tests published in 2016, which is the subject of the present commentary. The work has continued with two international inter-laboratory studies and one additional workshop held in Freising, Germany, in 2018. The dataset generated by the two inter-laboratory studies were used to refine the validation criteria for BMP tests. Based on these new results an update to the original guidelines is proposed here.

[Retrobulbar Haematoma - a Complication that May Impair Vision]. / Das retrobulbäre Hämatom ­ eine potenziell visusbedrohende Komplikation.

Retrobulbar haematoma (RBH) is a rare complication that may affect vision after a trauma or a surgical procedure. The diagnosis must be made promptly, as only early surgical intervention can adequately prevent irreversible visual impairment. Because of the bony orbital walls, there is hardly any room for the increasing intraorbital volume due to the retrobulbar haemorrhage. This leads to an increase in intraorbital pressure and subsequently to compression of the optic nerve. Symptoms include disorders in ocular motility, ophthalmoplegia, diplopia, conjunctival chemosis, subconjunctival haemorrhage, proptosis, increased intraocular pressure, deterioration in visual acuity, decreased direct pupillary reflex, and a relative afferent pupillary defect. If the cause is traumatic or iatrogenic, prompt lateral canthotomy with cantholysis is the treatment of choice, and successfully lowers pressure in most cases. It can be performed in the emergency room by an ophthalmologist and may even be indicated without previous imaging. As the reconstruction of cantholysis is generally uncomplicated, we recommend performing the procedure when RBH is suspected. If canthotomy with cantholysis does not lead to adequate improvement, surgical orbital decompression must be performed. Supportive treatment should always include systemic steroids.

Influence of COD/SO42- ratio on vinasse treatment performance by two-stage anaerobic membrane bioreactor.

Vinasse is sulfate-rich wastewater due to sulfuric acid dosage in some ethanol production steps. The vinasse sulfate concentration is subject to seasonal variations. A two-stage anaerobic membrane bioreactor (2S-AnMBR) was operated to evaluate the influence of COD/SO42- ratio on vinasse treatment performance by using a real vinasse sample under natural seasonal COD/SO42- variation. This ratio directly affects the sulfidogenesis efficiency, which is responsible for different forms of inhibition in the anaerobic treatment of sulfate-rich wastewater. The bioreactor presented a stable performance at the highest COD/SO42- ratios (50-94), with high removal of chemical oxygen demand (COD) (97.5 ± 0.4%) and volatile fatty acids (VFA) (98.0 ± 0.6%), but low removal of sulfate (69.9 ± 9.5%), indicating lower sulfate reducing bacteria (SRB) activity. In the lowest COD/SO42- ratios (9-20), a deterioration in the removal of organic matter (87.0 ± 1.3%) and VFA (69.8 ± 15.5%) was observed, accompanied by sulfate removal increase (92.9 ± 2.6%). A significant correlation between COD fractions removed via methanogenesis and sulfidogenesis and the COD/SO42- ratio was found, indicating that the increase of this ratio is beneficial to the methanogenic archaea activity. The occurrence of sulfidogenesis, favored by the lower COD/SO42- ratios, induced the microbial soluble products (SMP) and extracellular polymeric substances (EPS) release and protein/carbohydrate ratio increase in the mixed liquor, contributing to the filtration resistance increase.

[Intubation Systems in Lacrimal Drainage Surgery - a Current Overview]. / Intubationssysteme in der Tränenwegchirurgie ­ eine aktuelle Übersicht.

The development of microendoscopes in lacrimal drainage surgery has led to the introduction of novel surgical procedures that maintain transcanicular anatomy, including a variety of lacrimal drainage intubation systems. Depending on the location and extent of the lacrimal duct stenosis, bicanaliculoanular, monocanalicular, monocanaliculonasal, bicanalicular, and bicanaliculonasal intubation techniques and systems, as well as a combination of these, may be used. For isolated intubation of the puncta lacrimalia, perforated punctum plugs may be used, while pure monocanalicular intubation can be performed using a Mini-Monoka. The monocanaliculonasal intubation systems include the Monoka (Wide Collarette type), Monoka of Fayet (Crawford type), the self-threading Monoka (Ritleng type), the Masterka, and the LacriJet for the ophthalmic surgeon. The bicanaliculonasal intubation systems include various BIKA systems, the Ritleng intubation system, the Crawford intubation system, and the FCI Nunchaku. Indications for both monocanaliculonasal and bicanaliculonasal intubation systems are obstructions, stenoses or lacerations of all kinds, as well as obstructions and stenoses after opening or after a DCR. For a conjunctivodacryocystorhinostomy (CDCR), the classical Lester Jones Tube, Metaireau Tubes, and StopLoss Jones Tube may be used. Although the study situation is ambiguous and therefore lacrimal drainage intubation is not considered mandatory, most ophthalmic surgeons do not forego intubation - despite the higher costs and slightly more protracted surgery. The surgeons' selection of the intubation system depends on the chosen form of intubation, costs and personal preferences and experience.

Effects of Three Anti-Seizure Drugs on Cholinergic and Metabolic Activity in Experimental Status Epilepticus.

PURPOSE: Status epilepticus (SE) is characterized by recurrent seizure activity and can be drug- resistant. Knowledge of neuronal and metabolic activity of the brain during SE may be helpful to improve medical care. We here report the effects of three anti-seizure drugs on changes of acetylcholine energy metabolites and oxidative stress during SE. METHODS: We used the lithium-pilocarpine model in rats to induce SE and in vivo- microdialysis to monitor cholinergic and metabolic activity in the hippocampus. We measured extracellular concentrations of acetylcholine, glucose, lactate, pyruvate, glycerol and isoprostanes before and during SE, and after acute treatment with pregabalin, valproic acid, and levetiracteam. RESULTS: Upon onset of  SE, acetylcholine (ACh) release increased six- to eightfold. Glucose was increased only transiently by 30% but lactate levels rose four-fold, and extracellular concentrations of glycerol ten-fold. Isoprostanes are markers of oxidative stress and increased more than 20-fold. Two hours after pilocarpine adminstration, rats were treated with pregabalin (100 mg/kg), levetiracetam (200 mg/kg) or valproic acid (400 mg/kg) by i.p. injection. All three drugs stopped seizure activity in a delayed fashion, but at the doses indicated, only animals that received levetiracetam reached consciousness. All drugs reduced ACh release within 60-120 minutes. Lactate/pyruvate ratios, glycerol and isoprostanne levels were also reduced significantly after drug administration. CONCLUSIONS: Hippocampal ACh release closely follows seizure activity in SE and is attenuated when SE subsides. Pregabalin, valproic acid and levetiracetam all terminate seizures in the rat SE model and attenuate cholinergic and metabolic changes within two hours.

Reliability of periocular anthropometry using three-dimensional digital stereophotogrammetry.

PURPOSE: Non-invasive three-dimensional (3D) stereophotogrammetry is becoming increasingly popular in many fields. However, few studies have focused on its periocular application. We aimed to provide evidence for the periocular application of a novel anthropometric procedure using 3D stereophotogrammetry by evaluating its reliability. METHODS: Fifty-one Caucasians were recruited (102 eyes; mean age, 31.9 ± 13.6 years). Two sets of 3D images were acquired for each subject, and two measurement sessions were performed on each image by two raters. Fifty-two periocular landmarks were identified, and then 49 corresponding linear, curvilinear, and angular measurements were evaluated for intrarater, interrater, and intramethod reliability. RESULTS: Our findings showed highly reliable results for mean absolute difference (0.59 and 0.68 unit), relative error measurement (2.66% and 3.08%), technical error of measurement (0.59 and 0.66 unit), relative technical error of measurement (2.71% and 2.96%), and intraclass correlation coefficient (0.98) for intrarater 1 and intrarater 2 reliability; respectively 0.94 unit, 4.06%, 0.89 unit, and 3.94%, as well as 0.97 for interrater reliability; and respectively 0.98 unit, 4.66%, 0.96 unit, and 4.64%, as well as 0.96 for intramethod reliability. CONCLUSIONS: This imaging system and the landmark identification protocol are highly reliable. The collected measurements and their errors can be applied for the comparison of reliability among various 3D imaging systems and populations. It could be utilized for planning surgeries and evaluating treatment outcomes for physicians in ophthalmology, plastic and esthetic surgery, and in the maxillofacial field where periocular morphology alterations are made.

Cryolite glass prosthetic eyes-the response of the anophthalmic socket.

PURPOSE: To investigate mucoid discharge and the inflammatory response of anophthalmic sockets to cryolite glass prosthetic eye wear. PATIENTS AND METHODS: A total of 101 cryolite glass prosthetic eye wearers used visual analog scales (0-10) to measure frequency, color, volume, and viscosity of mucoid discharge associated with their prosthesis. Standardized photographs of the conjunctiva of their anophthalmic sockets were taken and conjunctival inflammation was semi-quantitatively graded (0-4). All characteristics of discharge and conjunctival inflammation were correlated to eye loss cause, hand washing behavior, and cleaning regimes as explanatory variables. RESULTS: Mean mucoid discharge characteristics (0-10 scale) were frequency 5.3 ± 2.8, color 4.8 ± 3.2, volume 4.9 ± 3.0, and viscosity 5.1 ± 3.2. The mean conjunctival inflammation score (0-4 scale) was 2.1 ± 1.0. There was a positive correlation between the grade of conjunctival inflammation and the frequency (p = 0.018), color (p = 0.001), volume (p = 0.003), and the viscosity of mucoid discharge (p = 0.005). More conjunctival inflammation was associated with higher frequency of cleaning (p < 0.001) and lower frequency of hand washing before removal (p = 0.001). Higher frequency, color, volume, and viscosity of discharge were associated with higher frequency of cleaning (p ≤ 0.001). CONCLUSIONS: Discharge severity associated with prosthetic eye wear was positively correlated with more conjunctival inflammation, higher cleaning frequency, and less hand washing before handling. The results suggest that cryolite glass eyes should not be removed daily for cleaning and that further research should be undertaken to develop a standardized treatment protocol for managing inflammation and mucoid discharge. This protocol would advise hand washing before handling cryolite glass eyes and recommend a minimum period of wear between cleaning sessions.

[Rehabilitation of Anophthalmic Patients with Prosthetic Eyes in Germany Today - Supply Possibilities, Daily Use, Complications and Psychological Aspects]. / Augenprothetische Rehabilitation in Deutschland heute ­ Versorgungsmöglichkeiten, Handhabung, Komplikationen und psychologische Aspekte.

BACKGROUND: A smooth supply with a visually appealing prosthetic eye after enucleation is not just a cosmetic solution, it is also a key factor in successful social and psychological rehabilitation. OBJECTIVES: This article provides an overview of the current state of medical and ocular care regarding prosthetic eyes in Germany. It focuses mainly on the newest clinical results, daily care, complications, and psychological aspects of wearing prosthetic eyes. METHODS: The study is comprised of the newest clinical results and a current PubMed literature review. RESULTS: In Germany, enucleated patients normally get a double-walled, hollow prosthetic eye made of cryolite glass, and patients with a microphthalmic or phthisic eye receive a thin single-walled prosthesis. Anophthalmic patients wearing cryolite glass prosthetic eyes seem to be more satisfied with their appearance and the look of their prostheses than polymethylmethacrylate (PMMA) prosthetic eye wearers. Cryolite glass prosthetic eyes must be renewed at least each year, while PMMA prostheses need to be polished once a year and renewed after five years of wearing. Among children, the fit of the prosthetic eye must be checked, based on growth, semi-annually. A slightly higher risk of breakage of cryolite glass prostheses is, for most patients, not a great disadvantage in everyday life. Ocularists and ophthalmologists should determine an individual cleaning regime, together with the patient, that is dependent on the material of the ocular prosthesis and other external factors. Complications, such as allergic, giant papillary, viral and bacterial conjunctivitis and blepharoconjunctivitis sicca must be treated at an early stage to allow for a prosthetic eye. In the case of inflammation-caused socket shrinkage or post-enucleation socket syndrome, surgical interventions are needed to re-enable the use of a prosthetic eye. Since the health of the remaining eye is the major psychological burden of prosthetic eye wearers, good ophthalmological care and medical screenings are essential elements. CONCLUSIONS: A smooth supply with a prosthetic eye, adequate and early treatment of possible complications and attention to psychological aspects is essential for successful long-term rehabilitation of enucleated patients.

Preexisting epiretinal membrane is associated with pseudophakic cystoid macular edema.

PURPOSE: The purpose of the present study was to evaluate whether preexisting epiretinal membrane (ERM) is a significant risk factor for developing pseudophakic cystoid macular edema (PCME). METHODS: Two hundred four consecutive eyes and 153 consecutive eyes without preexisting epiretinal membranes were retrospectively compared regarding PCME development following phacoemulsification with posterior chamber lens implantation. Patients with vascular retinal diseases, uveitis, trauma, neovascular macular degeneration, chronic inflammatory conditions, diabetic retinopathy, endophthalmitis, eventful cataract surgery, and combination of cataract surgery and vitrectomy during the observation period were excluded. Macular examination was performed using spectral-domain optical coherence tomography (SD-OCT) before as well as at 4, 8, 12, 16, 24, and 36 weeks after cataract surgery. Univariate and multivariate logistic regression analyses were calculated. RESULTS: PCME occurred in 32 of 204 eyes with preexisting ERM (15.7%), whereas 9 of 153 eyes without preexisting ERM (5.9%) developed PCME. The risk of PCME was significantly increased in eyes with ERM (p = 0.007). By multivariate logistic regression analysis, factors predictive of PCME included the history of previous pars plana vitrectomy for retinal detachment (odds ratio (OR) 3.619 [95% confidence interval (CI) 1.242 to 10.258]; p = 0.016) as well as the preexistence of ERM (OR 3.885 [95% CI 1.162 to 17.762]; p = 0.04). CONCLUSION: Preexisting ERM seems to be associated with an increased risk of PCME following cataract surgery. Therefore, this risk should be considered in surgery planning, preoperative medication, and follow-up care after surgery.

Concerns of anophthalmic patients-a comparison between cryolite glass and polymethyl methacrylate prosthetic eye wearers.

PURPOSE: To compare the concerns of experienced cryolite glass and (poly)methyl methacrylate (PMMA) prosthetic eye wearers. METHODS: One hundred six experienced cryolite glass and 63 experienced PMMA prosthetic eye wearers completed an anonymous questionnaire regarding general and specific prosthetic eye concerns at least 2 years after natural eye loss. From these independent anophthalmic populations, we identified 34 case-control pairs matched for the known influencing demographic variables of gender, occupation, age, and time since natural eye loss. RESULTS: The levels of concern were significantly lower in the cryolite glass group than those in the PMMA group for the following: loss of balance (p < 0.001), phantom sight vision (p < 0.001), pain (p < 0.001), receiving good advice (p = 0.001), fullness of orbit (p = 0.001), size (p = 0.007), direction of gaze relative to the healthy fellow eye (p = 0.005), eye lid contour (p = 0.037), comfort of the prosthetic eye (p < 0.001), colour relative to the healthy fellow eye (p < 0.001), and retention of the prosthetic eye (p < 0.001). Concerns about watering, crusting, discharge, visual perception, appearance, movement of the prosthetic eye, and health of the remaining eye were not significantly different between both groups. CONCLUSIONS: The results of this study showed that many general and specific levels of concern were significantly lower for cryolite glass prosthetic eye wearers than for PMMA prosthetic eye wearers. The question of why there are significant differences and to what extent the material of the prosthesis (cryolite glass or PMMA) has an impact on various concerns remains unanswered and should be addressed in a prospective comparative multicentre trial.

Concerns of Anophthalmic Patients Wearing Cryolite Glass Prosthetic Eyes.

PURPOSE: To identify the main concerns of patients experienced in wearing cryolite glass prosthetic eyes and to investigate how these have changed over time. METHODS: One hundred six patients experienced in wearing prosthetic eyes for at least 2 years were asked to complete an anonymous questionnaire regarding prosthetic eye concerns at the time of initial eye loss and at the present time. Main outcome measures included changes in levels of concern over time. RESULTS: Initially, the participants were mainly concerned about their appearance, health of the fellow eye, and coping with monocularity. Over time, there was a significant increase of the level of concern regarding the health of the remaining eye (p < 0.001) and regarding watering, crusting, and discharge (p < 0.001). Loss of balance did not change significantly (p = 0.302). All other concerns decreased significantly over time (p < 0.001), with levels of concern about appearance decreasing the most. The current leading concern was the health of the remaining eye followed by concerns about watering, crusting, and discharge. Length of time since natural eye loss was the most important explanatory variable, with significant impact on the concerns about appearance (p = 0.013), retention of the prosthetic eye (p = 0.002), and eyelid contour (p = 0.004). CONCLUSIONS: Health of the remaining eye is the most common current concern of anophthalmic patients, acknowledging the need of good ophthalmologic follow up after losing an eye. The second most important concern is with watering, crusting, and discharge, suggesting further research for establishing an evidence-based protocol for cryolite glass prosthetic eye maintenance and supportive treatment.

[Diagnosis and Therapy of Iris Lesions]. / Diagnostik und Therapie von Irisläsionen.

The most common iris lesions are iris nevi, iris melanomas and iris pigment epithelium cysts. However, there is an abundance of rare differential diagnoses that have to be considered, including other melanocytic and non-melanocytic lesions. Diagnostic tools include the slit lamp examination, gonioscopy, tonometry, transillumination, ultrasound biomicroscopy (UBM), optical coherence tomography, fluorescein angiography and standardized photography-assisted documentation. The timely identification of malignant lesions (i.e. iris melanoma) is paramount. To assess malignancy criteria of iris nevi, the ABCDEF rule (age young, blood, clock hour inferior, diffuse growth, ektropion uveae, feathery margins) can be applied. Statistically, up to 11% of iris nevi may develop into iris melanomas within 20 years. TNM Staging follows the 2010 AJCC cancer staging manual and helps determine the optimal treatment strategy. Treatment options include radiotherapy, such as plaque brachytherapy and proton beam radiation therapy, as well as surgical excision. Both the surgical and the radiotherapeutic approaches show comparable local tumor control rates. However, the spectrum of therapy-related side effects and complications may differ amongst treatment modalities. After initial treatment, patients should be followed up every 3 - 6 months. Tumor-related mortality ranges between 0 - 11% and is significantly lower than in other uveal melanomas. A prognostic value of common genetic alterations, which have been identified as significant prognostic factors in posterior uveal melanoma, could not be shown for iris melanoma.

[Minimally invasive Therapy of lacrimal Drainage System Stenosis]. / Minimalinvasive Therapie von Tränenwegstenosen.

Epiphora is one of the most common symptoms for clinical ophthalmological consultation. This symptom is mostly caused by stenosis of the lacrimal drainage system. Over a century, external dacryocystostomy according to Toti was the treatment of choice. Today, new very encouraging minimally invasive techniques for recanalisation of the lacrimal drainage system, such as microdrilldacryoplasty or laserdacryoplasty, as well as bypass-based techniques, such as transcanalicular laser-assisted dacryocystorhinostomy, become more important in the treatment of dacryostenosis.

Characterization of sulfur oxidizing bacteria related to biogenic sulfuric acid corrosion in sludge digesters.

BACKGROUND: Biogenic sulfuric acid (BSA) corrosion damages sewerage and wastewater treatment facilities but is not well investigated in sludge digesters. Sulfur/sulfide oxidizing bacteria (SOB) oxidize sulfur compounds to sulfuric acid, inducing BSA corrosion. To obtain more information on BSA corrosion in sludge digesters, microbial communities from six different, BSA-damaged, digesters were analyzed using culture dependent methods and subsequent polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE). BSA production was determined in laboratory scale systems with mixed and pure cultures, and in-situ with concrete specimens from the digester headspace and sludge zones. RESULTS: The SOB Acidithiobacillus thiooxidans, Thiomonas intermedia, and Thiomonas perometabolis were cultivated and compared to PCR-DGGE results, revealing the presence of additional acidophilic and neutrophilic SOB. Sulfate concentrations of 10-87 mmol/L after 6-21 days of incubation (final pH 1.0-2.0) in mixed cultures, and up to 433 mmol/L after 42 days (final pH <1.0) in pure A. thiooxidans cultures showed huge sulfuric acid production potentials. Additionally, elevated sulfate concentrations in the corroded concrete of the digester headspace in contrast to the concrete of the sludge zone indicated biological sulfur/sulfide oxidation. CONCLUSIONS: The presence of SOB and confirmation of their sulfuric acid production under laboratory conditions reveal that these organisms might contribute to BSA corrosion within sludge digesters. Elevated sulfate concentrations on the corroded concrete wall in the digester headspace (compared to the sludge zone) further indicate biological sulfur/sulfide oxidation in-situ. For the first time, SOB presence and activity is directly relatable to BSA corrosion in sludge digesters.

Towards a standardization of biomethane potential tests.

Production of biogas from different organic materials is a most interesting source of renewable energy. The biomethane potential (BMP) of these materials has to be determined to get insight in design parameters for anaerobic digesters. Although several norms and guidelines for BMP tests exist, inter-laboratory tests regularly show high variability of BMPs for the same substrate. A workshop was held in June 2015, in Leysin, Switzerland, with over 40 attendees from 30 laboratories around the world, to agree on common solutions to the conundrum of inconsistent BMP test results. This paper presents the consensus of the intense roundtable discussions and cross-comparison of methodologies used in respective laboratories. Compulsory elements for the validation of BMP results were defined. They include the minimal number of replicates, the request to carry out blank and positive control assays, a criterion for the test duration, details on BMP calculation, and last but not least criteria for rejection of the BMP tests. Finally, recommendations on items that strongly influence the outcome of BMP tests such as inoculum characteristics, substrate preparation, test setup, and data analysis are presented to increase the probability of obtaining validated and reproducible results.