Instructions for the use of L-PRF in different clinical indications.

Autologous platelet concentrates (APCs) have demonstrated clear benefits across various clinical applications, including alveolar ridge preservation, guided tissue regeneration, guided bone regeneration, sinus floor elevation (both lateral window approach and transcrestal technique), endodontic surgery, the treatment of medication-related osteonecrosis of the jaw bones, and periodontal plastic surgery. To ensure an optimal clinical outcome, clinicians must adhere strictly to the protocol to prepare the APCs and, especially follow evidence-based surgical guidelines, often simple but crucial, to minimize the likelihood of errors. The majority of clinical trials reported on second-generation APCs [the leukocyte- and platelet-rich fibrin (L-PRF) family, including its modifications (A-PRF, A-PRF+, CGF, T-PRF, H-PRF, etc.)]. These second-generation APCs offer additional benefits compared to the first-generation APCs, making them the preferred choice for the development of clinical recommendations. These recommendations have been formulated through a meticulous examination of the available clinical data and the clinical experience of the authors of this paper.

Pregnancy loss in major fetal congenital heart disease: incidence, risk factors and timing.

OBJECTIVE: Fetuses with congenital heart disease (CHD) are at increased risk of pregnancy loss compared with the general population. We aimed to assess the incidence, timing and risk factors of pregnancy loss in cases with major fetal CHD, overall and according to cardiac diagnosis. METHODS: This was a retrospective, population-level cohort study of fetuses and infants diagnosed with major CHD between 1997 and 2018 identified by the Utah Birth Defect Network (UBDN), excluding cases with termination of pregnancy and minor cardiovascular diagnoses (e.g. isolated aortic/pulmonary pathology and isolated septal defects). The incidence and timing of pregnancy loss were recorded, overall and according to CHD diagnosis, with further stratification based on presence of isolated CHD vs additional fetal diagnosis (genetic diagnosis and/or extracardiac malformation). Adjusted risk of pregnancy loss was calculated and risk factors were assessed using multivariable models for the overall cohort and prenatal diagnosis subgroup. RESULTS: Of 9351 UBDN cases with a cardiovascular code, 3251 cases with major CHD were identified, resulting in a study cohort of 3120 following exclusion of cases with pregnancy termination (n = 131). There were 2956 (94.7%) live births and 164 (5.3%) cases of pregnancy loss, which occurred at a median gestational age of 27.3 weeks. Of study cases, 1848 (59.2%) had isolated CHD and 1272 (40.8%) had an additional fetal diagnosis, including 736 (57.9%) with a genetic diagnosis and 536 (42.1%) with an extracardiac malformation. The observed incidence of pregnancy loss was highest in the presence of mitral stenosis (< 13.5%), hypoplastic left heart syndrome (HLHS) (10.7%), double-outlet right ventricle with normally related great vessels or not otherwise specified (10.5%) and Ebstein's anomaly (9.9%). The adjusted risk of pregnancy loss was 5.3% (95% CI, 3.7-7.6%) in the overall CHD population and 1.4% (95% CI, 0.9-2.3%) in cases with isolated CHD (adjusted risk ratio, 9.0 (95% CI, 6.0-13.0) and 2.0 (95% CI, 1.0-6.0), respectively, based on the general population risk of 0.6%). On multivariable analysis, variables associated with pregnancy loss in the overall CHD population included female fetal sex (adjusted odds ratio (aOR), 1.6 (95% CI, 1.1-2.3)), Hispanic ethnicity (aOR, 1.6 (95% CI, 1.0-2.5)), hydrops (aOR, 6.7 (95% CI, 4.3-10.5)) and additional fetal diagnosis (aOR, 6.3 (95% CI, 4.1-10)). On multivariable analysis of the prenatal diagnosis subgroup, years of maternal education (aOR, 1.2 (95% CI, 1.0-1.4)), presence of an additional fetal diagnosis (aOR, 2.7 (95% CI, 1.4-5.6)), atrioventricular valve regurgitation ≥ moderate (aOR, 3.6 (95% CI, 1.3-8.8)) and ventricular dysfunction (aOR, 3.8 (95% CI, 1.2-11.1)) were associated with pregnancy loss. Diagnostic groups associated with pregnancy loss were HLHS and variants (aOR, 3.0 (95% CI, 1.7-5.3)), other single ventricles (aOR, 2.4 (95% CI, 1.1-4.9)) and other (aOR, 0.1 (95% CI, 0-0.97)). Time-to-pregnancy-loss analysis demonstrated a steeper survival curve for cases with an additional fetal diagnosis, indicating a higher rate of pregnancy loss compared to cases with isolated CHD (P < 0.0001). CONCLUSIONS: The risk of pregnancy loss is higher in cases with major fetal CHD compared with the general population and varies according to CHD type and presence of additional fetal diagnoses. Improved understanding of the incidence, risk factors and timing of pregnancy loss in CHD cases should inform patient counseling, antenatal surveillance and delivery planning. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Increased H2O2 levels and p53 stabilization lead to mitochondrial dysfunction in XPC-deficient cells.

XPC deficiency is associated with mitochondrial dysfunction, increased mitochondrial H2O2 production and sensitivity to the Complex III inhibitor antimycin A (AA), through a yet unclear mechanism. We found an imbalanced expression of several proteins that participate in important mitochondrial function and increased expression and phosphorylation of the tumor suppressor p53 in Xeroderma pigmentosum complementation group C (XP-C) (XPC-null) cells compared with an isogenic line corrected in locus with wild-type XPC (XPC-wt). Interestingly, inhibition of p53 nuclear import reversed the overexpression of mitochondrial proteins, whereas AA treatment increased p53 expression more strongly in the XP-C cells. However, inhibition of p53 substantially increased XP-C cellular sensitivity to AA treatment, suggesting that p53 is a critical factor mediating the cellular response to mitochondrial stress. On the other hand, treatment with the antioxidant N-acetylcysteine increased glutathione concentration and decreased basal H2O2 production, p53 levels and sensitivity to AA treatment in the XPC-null back to the levels found in XPC-wt cells. Thus, the results suggest a critical role for mitochondrially generated H2O2 in the regulation of p53 expression, which in turn modulates XP-C sensitivity to agents that cause mitochondrial stress.

Cross-cultural validation of the Portuguese from Portugal version of the Test for Respiratory and Asthma Control in Kids (TRACK) questionnaire.

SUMMARY: Introduction. The Test for Respiratory and Asthma Control in Kids (TRACK) is a tool to assess asthma control in preschool children. This study aims to validate the Portuguese from Portugal version of the TRACK questionnaire. Methods. A prospective cohort study was carried out to assess their psychometric characteristics. Caregivers of 141 children under age 5 with asthma symptoms were enrolled. Results. Internal reliability was close to 0.70 (Cronbach's α). The test-retest reliability was 0.87. TRACK scores were different between well, partially, and non-controlled asthma groups (p less than 0.001). Patients rated as having better control showed an increase in TRACK scores. Conclusions. The Portuguese version of the TRACK questionnaire is accurate and reliable for monitoring asthma control. Its use may help to overcome challenges with the management of this age group.

Short and extended provocation tests have similar negative predictive value in non-immediate hypersensitivity to beta-lactams in children.

INTRODUCTION AND OBJECTIVES: Drug provocation tests (DPTs) are the gold-standard method to diagnose non-immediate hypersensitivity reactions (NIHSR) to beta-lactam antibiotics (BL) in children. Our aim was to compare the negative predictive value (NPV) of one-day (short) DPT versus 3-7 days (extended) DPT for the diagnosis of NIHSR to BL in paediatric age. A secondary aim was to compare confidence on drug re-exposure after short and extended negative DPTs. METHODS: The occurrence of HSR on drug re-exposure and drug refusal after negative diagnostic DPTs were evaluated in children/adolescents with a history of NIHSR to BL using a questionnaire performed six months to ten years after DPT. Patients were divided into two groups according to the protocol performed: short DPT vs. extended DPT. RESULTS: We enrolled 212 children and adolescents (86 females, 126 males, mean age at DPT 5.52 years, p25=3 years, p75=7.25 years): 69 tested with short DPT, and 143 with extended DPT. The NPV of both types of DPT together was 95.2%. The NPV of short DPT was 97.5% and the NPV of extended DPT was 93.8% (p=0.419). After negative DPT, beta-lactams were refused by carers in 14.75% of the children requiring subsequent treatment, 6.98% in the short DPT group and 18.99% in the extended DPT group (p=0.074). CONCLUSIONS: In our paediatric sample, prolonging drug administration did not increase the NPV of diagnostic DPT for NIHSR to BL or reduce drug refusal. Altogether, the data here reported suggest that, however intuitive, prolonging DPT is not beneficial in the parameters analysed.

Effect of carrier tunneling on the structure of Si nanowires fabricated by metal assisted etching.

The metal assisted etching mechanism for Si nanowire fabrication, triggered by doping type and level and coupled with choice of metal catalyst, is still very poorly understood. We explain the different etching rates and porosities of wires we observe based on extensive experimental data, using a new empirical model we have developed. We establish as a key parameter, the tunneling through the space charge region (SCR) which is the result of the reduction of the SCR width by level of the Si wafer doping in the presence of the opposite biases of the p- and n-type wafers. This improved understanding should permit the fabrication of high quality wires with predesigned structural characteristics, which hitherto has not been possible.

Toxocara canis: anthelmintic activity of quinone derivatives in murine toxocarosis.

Human toxocarosis is a chronic tissue parasitosis most often caused by Toxocara canis. The seroprevalence can reach up to 50%, especially among children and adolescents. The anthelmintics used in the treatment have moderate efficacy. The aim of this study was to evaluate the in vitro and in vivo anthelmintic activity of quinones and their derivatives against T. canis larvae and the cytotoxicity of the larvicidal compounds. The compounds were evaluated at 1 mg mL(-1) concentration in microculture plates containing third stage larvae in an Roswell Park Memorial Institute (RPMI) 1640 environment, incubated at 37 °C in 5% CO2 tension for 48 h. Five naphthoxiranes were selected for the cytotoxicity analysis. The cell viability evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and lactate dehydrogenase assays using murine peritoneal macrophages isolated from C57BL/6 mice revealed that the naphthoxiranes (1 and 3) were less cytotoxic at a concentration of 0.05 mg mL(-1). The efficacy of naphthoxiranes (1 and 3) was examined in murine toxocarosis also. The anthelmintic activity was examined by evaluating the number of larvae in the brain, carcass, liver, lungs, heart, kidneys and eyes. Compound (3) demonstrated anthelmintic activity similar to that of albendazole by decreasing the number of larvae in the organs of mice and thus could form the basis of the development of a new anthelmintic drug.

Characterization and complete genome sequence analysis of two Myoviral bacteriophages infecting clinical carbapenem-resistant Acinetobacter baumannii isolates.

AIMS: The aim of this study was to characterize phenotypical properties, to analyse whole genomes of novel Acinetobacter baumannii phages infecting carbapenem-resistant Ac. baumannii (CRAB) and to evaluate their potential as antimicrobial alternatives to control Ac. baumannii in clinical settings. METHODS AND RESULTS: The Ac. baumannii phages, Βϕ-R1215 and Βϕ-R2315, were isolated from sewage samples. These phages were characterized by transmission electron microscopy, host spectrum, the thermal/pH stability test, the bacterial lysis assay and the whole genome analysis. Both phages lysed 21 of 45 CRAB hosts, and showed high stability at various pH (pH 4-10) and temperature (25-60°C), and were strongly active against host bacteria in vitro. The genomes of Βϕ-R1215 and Βϕ-R2315 are linear double-strands of DNA with 44·866 and 44·846 bp respectively. These two genomes revealed high similarity at the DNA level, but the organization and direction of open reading frames were different. CONCLUSIONS: The Ac. baumannii phages, Βϕ-R1215 and Βϕ-R2315, are novel lytic phages lysing CRAB strains which were isolated from respiratory samples of patients. SIGNIFICANCE AND IMPACT OF THE STUDY: In vitro and in silico data showed that these novel Ac. baumannii phages, Βϕ-R1215 and Βϕ-R2315, have potential as antimicrobial alternatives to control CRAB in healthcare settings.

B-cell epitopes of antigenic proteins in Leishmania infantum: an in silico analysis.

Serodiagnosis of visceral leishmaniasis is often hindered by cross-reactions to other parasitic diseases. Identifying specific B-cell epitopes in proteins is therefore important for immunodiagnostics, as well as for disease control by vaccines. This study aimed to identify linear and conformational B-cell epitopes and to evaluate the secondary structure of antigen proteins in Leishmania infantum using in silico analysis. Linear epitopes were predicted using the Immune Epitope Database and Analysis Resource (IEDB), BepiPred and BcePred programs. The conformational B-cell epitopes were identified using the CBTOPE server. The combination of the predictions using IEDB, BepiPred and BcePred generated 148 linear epitopes from the calpain-like cysteine peptidase (CP), thiol-dependent reductase 1 (TDR1) and HSP70 proteins. In total, 164 conformational epitopes were predicted, mostly located in the linear epitope region. The predicted epitopes are located in α helix and random coil regions in the thiol-dependent reductase 1 and HSP70 proteins. New linear and conformational B-cell epitopes of L. infantum proteins were identified in silico, and the prediction using various programs ensures greater accuracy of the results, as suggested by confirmation of previously identified HSP70 epitopes.

Cost-effectiveness of prenatal screening strategies for congenital heart disease.

OBJECTIVE: The economic implications of strategies to improve prenatal screening for congenital heart disease (CHD) in low-risk mothers have not been explored. The aim was to perform a cost-effectiveness analysis of different screening methods. METHODS: We constructed a decision analytic model of CHD prenatal screening strategies (four-chamber screen (4C), 4C + outflow, nuchal translucency (NT) or fetal echocardiography) populated with probabilities from the literature. The model included whether initial screens were interpreted by a maternal-fetal medicine (MFM) specialist and different referral strategies if they were read by a non-MFM specialist. The primary outcome was the incremental cost per defect detected. Costs were obtained from Medicare National Fee estimates. A probabilistic sensitivity analysis was undertaken on model variables commensurate with their degree of uncertainty. RESULTS: In base-case analysis, 4C + outflow referred to an MFM specialist was the least costly strategy per defect detected. The 4C screen and the NT screen were dominated by other strategies (i.e. were more costly and less effective). Fetal echocardiography was the most effective, but most costly. On simulation of 10 000 low-risk pregnancies, 4C + outflow screen referred to an MFM specialist remained the least costly per defect detected. For an additional $580 per defect detected, referral to cardiology after a 4C + outflow was the most cost-effective for the majority of iterations, increasing CHD detection by 13 percentage points. CONCLUSIONS: The addition of examination of the outflow tracts to second-trimester ultrasound increases detection of CHD in the most cost-effective manner. Strategies to improve outflow-tract imaging and to refer with the most efficiency may be the best way to improve detection at a population level.

A randomized clinical trial of adjuvant chemotherapy with doxorubicin, ifosfamide, and cisplatin followed by radiotherapy versus radiotherapy alone in patients with localized uterine sarcomas (SARCGYN study). A study of the French Sarcoma Group.

BACKGROUND: There is no proven benefit of adjuvant treatment of uterine sarcoma (US). SARCGYN phase III study compared adjuvant polychemotherapy followed by pelvic radiotherapy (RT) (arm A) versus RT alone (arm B) conducted to detect an increase ≥ 20% of 3-year PFS. METHODS: Patients with FIGO stage ≤ III US, physiological age ≤ 65 years; chemotherapy: four cycles of doxorubicin 50 mg/m² d1, ifosfamide 3 g/m²/day d1-2, cisplatin 75 mg/m² d3, (API) + G-CSF q 3 weeks. Study was stopped because of lack of recruitment. RESULTS: Eighty-one patients were included: 39 in arm A and 42 in arm B; 52 stage I, 16 stage II, 13 stage III; 53 leiomyosarcomas, 9 undifferenciated sarcomas, 19 carcinosarcomas. Gr 3-4 toxicity during API (/37 patients): thrombopenia (76%), febrile neutropenia (22%) with two toxic deaths; renal gr 3 (1 patient). After a median follow-up of 4.3 years, 41/81 patients recurred, 15 in arm A, 26 in arm B. The 3 years DFS is 55% in arm A, 41% in arm B (P = 0.048). The 3-year overall survival (OS) is 81% in arm A and 69% in arm B (P = 0.41). CONCLUSION: API adjuvant CT statistically increases the 3 year-DFS of patients with US.

A systematic evaluation of normalization methods and probe replicability using infinium EPIC methylation data.

BACKGROUND: The Infinium EPIC array measures the methylation status of > 850,000 CpG sites. The EPIC BeadChip uses a two-array design: Infinium Type I and Type II probes. These probe types exhibit different technical characteristics which may confound analyses. Numerous normalization and pre-processing methods have been developed to reduce probe type bias as well as other issues such as background and dye bias. METHODS: This study evaluates the performance of various normalization methods using 16 replicated samples and three metrics: absolute beta-value difference, overlap of non-replicated CpGs between replicate pairs, and effect on beta-value distributions. Additionally, we carried out Pearson's correlation and intraclass correlation coefficient (ICC) analyses using both raw and SeSAMe 2 normalized data. RESULTS: The method we define as SeSAMe 2, which consists of the application of the regular SeSAMe pipeline with an additional round of QC, pOOBAH masking, was found to be the best performing normalization method, while quantile-based methods were found to be the worst performing methods. Whole-array Pearson's correlations were found to be high. However, in agreement with previous studies, a substantial proportion of the probes on the EPIC array showed poor reproducibility (ICC < 0.50). The majority of poor performing probes have beta values close to either 0 or 1, and relatively low standard deviations. These results suggest that probe reliability is largely the result of limited biological variation rather than technical measurement variation. Importantly, normalizing the data with SeSAMe 2 dramatically improved ICC estimates, with the proportion of probes with ICC values > 0.50 increasing from 45.18% (raw data) to 61.35% (SeSAMe 2).

Barriers to prenatal detection of congenital heart disease: a population-based study.

OBJECTIVE: To evaluate the extent and determinants of missed prenatal detection of congenital heart disease (CHD) in a population-based setting. METHODS: This was a retrospective cohort study of cases with CHD, excluding minor defects, identified between 1997 and 2007 by a statewide surveillance program. We examined a comprehensive list of potential risk factors for which data were available in the surveillance database from abstracted medical charts. We analyzed the association of fetal, maternal and encounter factors with 1) whether a prenatal ultrasound was performed and 2) prenatal detection of CHD. RESULTS: CHD was detected prenatally in only 39% of 1474 cases, with no improvement in detection rate over the 10-year period. Among the 97% (n = 1431) of mothers who underwent one or more ultrasound examinations, 35% were interpreted as abnormal; fetal echocardiography was performed in 27% of the entire cohort. Maternal and encounter factors increasing the adjusted odds of prenatal detection included: family history of CHD (OR, 4.3 (95% CI, 1.9-9.9)), presence of extracardiac defects (OR, 2.7 (95% CI, 1.9-3.9)) and ultrasound location i.e. high risk clinic vs clinic (OR, 2.1 (95% CI, 1.3-3.1)). Defects that would be expected to have an abnormal outflow-tract view were missed more often (64%) than were those that would be expected to have an abnormal four-chamber view (42%). CONCLUSION: The majority of CHD cases over the 10-year study period were missed prenatally and detection rates did not increase materially during that time. The failure to detect CHD prenatally was related to encounter characteristics, specifically involving screening ultrasound examinations, which may be targeted for improvement.

Bacillus spp. toxicity against Haemonchus contortus larvae in sheep fecal cultures.

The gastrointestinal nematode Haemonchus contortus is a major productivity constraint in sheep. In this study, the nematicidal effects of Bacillus circulans, Bacillus cereus, Bacillus thuringiensis var. israelensis, Bt. var. osvaldocruzi, Bt. var. morrisoni, and Bt. var. kurstaki were assessed in free-living larval stages of H. contortus. A spore-crystal suspension containing approximately 2×10(8)UFC/mL of each strain was added to sheep feces that were naturally infected with H. contortus eggs, and the presence of larvae was then evaluated. We observed a significant (p>0.05) reduction in larval development when using B. circulans, B. thuringiensis var. israelensis, Bt. var. osvaldocruzi and Bt. var. kurstaki, and these effects were proportional with the amount of bacteria added to the feces. However, no effect was observed when Bt. var. morrisoni or B. cereus was added. These observations suggest that these bacteria might be effective as nematicides and may allow for the development of integrated biological control of zooparasitic nematodes.

Current intraoperative storage and handling practices of autologous bypass conduit: A survey of the royal australasian college of surgeons.

During bypass surgery for peripheral arterial occlusive disease and ischaemic heart disease, autologous graft conduit including great saphenous veins and radial arteries are frequently stored in solution. Endothelial damage adversely affects the performance and patency of autologous bypass grafts, and intraoperative graft storage solutions have been shown to influence this process. The distribution of storage solutions currently used amongst Cardiothoracic and Vascular Surgeons from Australia and New Zealand is not well defined in the literature. The aim of this study was to determine current practices regarding autologous graft storage and handling amongst this cohort of surgeons, and discuss their potential relevance in the context of early graft failure. From this survey, the most frequently used storage solutions were heparinized saline for great saphenous veins, and pH-buffered solutions for radial arteries. Duration of storage was 30-45 min for almost half of respondents, although responses to this question were limited. Further research is required to investigate whether ischaemic endothelial injury generates a prothrombotic state, whether different storage media can alter this state, and whether this is directly associated with clinical outcomes of interest such as early graft failure.

The role of mitochondrial DNA damage in the citotoxicity of reactive oxygen species.

Mitochondria contain their own genome, a small circular molecule of around 16.5 kbases. The mitochondrial DNA (mtDNA) encodes for only 13 polypeptides, but its integrity is essential for mitochondrial function, as all 13 proteins are regulatory subunits of the oxidative phosphorylation complexes. Nonetheless, the mtDNA is physically associated with the inner mitochondrial membrane, where the majority of the cellular reactive oxygen species are generated. In fact, the mitochondrial DNA accumulates high levels of oxidized lesions, which have been associated with several pathological and degenerative processes. The cellular responses to nuclear DNA damage have been extensively studied, but so far little is known about the functional outcome and cellular responses to mtDNA damage. In this review we will discuss the mechanisms that lead to damage accumulation and the in vitro models we are establishing to dissect the cellular responses to oxidative damage in the mtDNA and to sort out the differential cellular consequences of accumulation of damage in each cellular genome, the nuclear and the mitochondrial genome.

Pharmacokinetics of amikacin in plasma and selected body fluids of healthy horses after a single intravenous dose.

REASONS FOR PERFORMING STUDY: No studies have determined the pharmacokinetics of low-dose amikacin in the mature horse. OBJECTIVES: To determine if a single i.v. dose of amikacin (10 mg/kg bwt) will reach therapeutic concentrations in plasma, synovial, peritoneal and interstitial fluid of mature horses (n=6). METHODS: Drug concentrations of amikacin were measured across time in mature horses (n=6); plasma, synovial, peritoneal and interstitial fluid were collected after a single i.v. dose of amikacin (10 mg/kg bwt). RESULTS: The mean±s.d. of selected parameters were: extrapolated plasma concentration of amikacin at time zero 144±21.8 µg/ml; extrapolated plasma concentration for the elimination phase 67.8±7.44 µg/ml, area under the curve 139±34.0 µg*h/ml, elimination half-life 1.34±0.408 h, total body clearance 1.25±0.281 ml/min/kg bwt; and mean residence time (MRT) 1.81±0.561 h. At 24 h, the plasma concentration of amikacin for all horses was below the minimum detectable concentration for the assay. Selected parameters in synovial and peritoneal fluid were maximum concentration (Cmax) 19.7±7.14 µg/ml and 21.4±4.39 µg/ml and time to maximum concentration 65±12.2 min and 115±12.2 min, respectively. Amikacin in the interstitial fluid reached a mean peak concentration of 12.7±5.34 µg/ml and after 24 h the mean concentration was 3.31±1.69 µg/ml. Based on a minimal inhibitory concentration (MIC) of 4 µg/ml, the mean Cmax:MIC ratio was 16.9±1.80 in plasma, 4.95±1.78 in synovial fluid, 5.36±1.10 in peritoneal fluid and 3.18±1.33 in interstitial fluid. CONCLUSIONS: Amikacin dosed at 10 mg/kg bwt i.v. once a day in mature horses is anticipated to be effective for treatment of infection caused by most Gram-negative bacteria. POTENTIAL RELEVANCE: Low dose amikacin (10 mg/kg bwt) administered once a day in mature horses may be efficacious against susceptible microorganisms.

Impact of g force and timing on the characteristics of platelet-rich fibrin matrices.

Recently, new centrifugation protocols for the preparation of platelet-rich fibrin (PRF) have been introduced in an attempt to further improve the beneficial impact of these 2nd generation platelet concentrate membranes. This in-vitro study aimed to compare the biological and physical characteristics of three types of PRF membranes using two different centrifuges with adapted relative centrifugal forces (RCF): leucocyte- and platelet-rich fibrin, advanced platelet-rich fibrin, and advanced platelet-rich fibrin+. Release of growth factors, macroscopic dimensions, cellular content and mechanical properties of the respective membranes, prepared from blood of the same individual were explored. Furthermore, the impact of timing (blood draw-centrifugation and centrifugation-membrane preparation) was assessed morphologically as well as by electron microscopy scanning. No statistically significant differences amongst the three PRF modifications could be observed, neither in their release of growth factors or the cellular content, nor in clot/membrane dimensions. The difference between both centrifuges were negligible when the same g-force was used. A lower g-force, however, reduced membrane tensile strength. Timing in the preparation process had a significant impact. Adaptation of RCF only had a minimal impact on the final characteristics of PRF membranes.