Evaluation of bone texture imaging parameters on panoramic radiographs of patients with Sheehan's syndrome: a STROBE-compliant case-control study.

Sheehan's syndrome (SHS) is a rare condition related to the risk of osteoporosis and evaluation of bone texture imaging features on panoramic radiographs would be suitable for this condition, which was the aim of the present study. Fractal dimension, lacunarity, and trabecular morphologic aspects were significantly altered in these patients. INTRODUCTION: SHS is an important public health problem particularly in developing countries. It is characterized as postpartum hypopituitarism secondary to obstetric complications-related ischemic pituitary necrosis that shows significant systemic metabolic repercussions. Thus, this study aimed to evaluate bone texture parameters in digital panoramic radiographs of patients with SHS. METHODS: A case-control study was conducted with 30 SHS patients from an Endocrinology and Diabetology Service of reference in Brazil, and 30 age- and sex-matched healthy controls. A custom computer program measured fractal dimension, lacunarity, and some morphologic features in the following mandibular regions of interest (50 × 50 pixels): below the mental foramen (F1), between the first and second molars (M1), and at the center of the mandibular ramus (R1). RESULTS: The fractal analysis showed a statistically significant difference between the studied groups in all regions of interest. The fractal dimension in F1 (p = 0.016), M1 (p = 0.043), and R1 (p = 0.028) was significantly lower in SHS group, as well as lacunarity in R1 (p = 0.008). Additionally, several morphologic features were statistically significant in the SHS group (p < 0.05). CONCLUSION: Therefore, individuals with SHS showed altered imaging texture parameters on panoramic radiographs, which reflect a smaller spatial organization of the bone trabeculae and, possibly, a state of reduced mineral bone density.

Next generation sequencing in bleeding disorders: two novel variants in the F5 gene (Valencia-1 and Valencia-2) associated with mild factor V deficiency.

Inherited bleeding coagulation disorders (IBCDs) have a powerful diagnostic tool in next generation sequencing (NGS) that not only offers confirmation of diagnosis but also aids in genetic counselling, prenatal diagnosis and helps to predict the clinical course and follow-up of a disease. In our group, targeted-NGS using a Custom SureSelect QXT Panel (Agilent Technologies, Inc., Santa Clara, CA, USA) was designed to screen for causal variants in 40 genes related with the coagulation cascade. In this work, we used NGS for screening all the coding and intronic boundary regions of F5 gene in two patients affected by factor V (FV) deficiency (parahemophilia). Two new mutations were found: c.4745A>G (p.Tyr1582Cys, NM_000130.4) and c.1999_2002dupAATT (p.Ser668ter; NM_000130.4), both located in exon 13 of the F5 gene. We designated them Valencia-1 and Valencia-2 respectively. Valencia-1 could provoke loss of the fifth cupredoxin domain of the FV, and would be responsible for its defective activity. Valencia-2 prematurely stops the translation of mRNA, resulting in a truncated FV protein which lacks completely the B domain and the light chain. NGS has permitted to describe an increasing number of FV deficiency-causing mutations and a better understanding of FV's structure and function. The description of deficiency-causing mutations will continue to increase our knowledge of the functional residues of FV, as well as those which are involved in the correct folding of the protein. In this sense, NGS is a useful tool for studying IBCDs, as permits studying the whole coagulation cascade at once and gives a global view of the patient's genetic background.

Surface-Induced Near-Field Scaling in the Knudsen Layer of a Rarefied Gas.

We report on experiments performed within the Knudsen boundary layer of a low-pressure gas. The noninvasive probe we use is a suspended nanoelectromechanical string, which interacts with ^{4}He gas at cryogenic temperatures. When the pressure P is decreased, a reduction of the damping force below molecular friction ∝P had been first reported in Phys. Rev. Lett. 113, 136101 (2014)PRLTAO0031-900710.1103/PhysRevLett.113.136101 and never reproduced since. We demonstrate that this effect is independent of geometry, but dependent on temperature. Within the framework of kinetic theory, this reduction is interpreted as a rarefaction phenomenon, carried through the boundary layer by a deviation from the usual Maxwell-Boltzmann equilibrium distribution induced by surface scattering. Adsorbed atoms are shown to play a key role in the process, which explains why room temperature data fail to reproduce it.

Incorporation of photobiomodulation therapy into a therapeutic exercise program for knee osteoarthritis: A placebo-controlled, randomized, clinical trial.

OBJECTIVE: To investigate the clinical effects of incorporation of phototherapy in a therapeutic exercise program for individuals with knee osteoarthritis (OA) when compared to a group that received exercise alone and to a group that received exercise + placebo phototherapy. MATERIALS AND METHODS: This is a randomized, blinded and placebo-controlled trial. Thus, sixty male and female individuals aged 40-80 years with knee pain in the previous 6 months participated of the study, with diagnosis of unilateral knee OA based on the criteria established by the American College of Rheumatology and radiographic confirmation and Grades 2 or 3 of the Kellgren-Lawrence Classification. The individuals were equally divided in the groups exercise alone, exercise + active phototherapy (nine-diode cluster device: one 905 nm super-pulsed diode laser, four 875 nm LED and four 640 nm LED; energy per quadrant: 7.85 J; total energy: 23.55 J per session), or exercise + placebo phototherapy. Treatments were performed twice a week for 5 consecutive weeks. Patients were evaluated before and after the sessions of treatment. The outcome measures were: Western Ontario and McMaster University Osteoarthritis Index (WOMAC), Lower Extremity Functional Scale (LEFS), Numerical Rating Pain Scale (NRPS), pressure pain threshold (PPT) in two points of knee, muscle strength, and the Functional Reach Test (FRT). RESULTS: Exercise + active phototherapy was significantly more effective than exercise alone (mean difference [MD] = 2.75, 95% confidence interval [CI] = 3.17 to 2.32) and exercise + placebo phototherapy (MD = 2.38, 95% CI = 2.79 to 1.96) only with regard to the NRPS, considering minimal clinically important difference. No clinical significant results were found for function, the pressure pain threshold, muscle strength or balance. CONCLUSIONS: The combination of phototherapy and an exercise program is effective at reducing pain intensity among individuals with knee osteoarthritis than exercise alone or exercise + placebo phototherapy in a short-term protocol. Lasers Surg. Med. 50:819-828, 2018. © 2018 Wiley Periodicals, Inc.

Stromal Growth Differentiation Factor 15 and Its Association with Ovarian Cancer.

BACKGROUND/AIMS: Growth differentiation factor 15 (GDF-15) is induced by pro-inflammatory cytokines. Higher levels of GDF-15 have been associated with malignancy. The aim of the study was to evaluate both tissue and serum levels of GDF-15 in ovarian neoplasms. METHODS: A cohort study evaluated 31 patients with benign ovarian tumors and 34 patients with ovarian cancer were evaluated in 2 years. The inclusion criterion was histopathological diagnosis of ovarian epithelial neoplasia. Exclusion criteria were secondary malignant ovarian neoplasia and preoperative treatment. Serum and tissue levels of GDF-15 were assessed by enzyme-linked immunosorbent assay and immunohistochemistry, respectively. Chi-square test and unpaired t test were performed. RESULTS: Serum levels were higher in the patients with malignant neoplasms than in the patients with benign tumors, yet the difference was not statistically significant. GDF-15 immunostaining was significantly more frequent in the stroma of the malignant tumors than in the stroma of the benign tumors (p = 0.0034). CONCLUSION: GDF-15 staining is elevated in the stroma of ovarian cancer, demonstrating that it may be a potential diagnostic and therapeutic target.

Dental status, salivary flow, and sociodemographic aspects in Sheehan Syndrome patients.

BACKGROUND: Sheehan's syndrome (SS) is one of the leading causes of hypopituitarism in developing countries. It occurs after postpartum necrosis of the pituitary gland, and it is considered a significant public health problem. This paper, apparently unpublished, aimed to perform an analysis on oral aspects in patients with SS. MATERIAL AND METHODS: A cross-sectional study was performed with 23 women diagnosed with SS at the Division of Endocrinology and Diabetes (Walter Cantidio University Hospital, Fortaleza, Brazil). RESULTS: Data on sociodemographic, dental and salivary flow aspects were collected through a clinical approach and a panoramic radiograph request. The mean age was 64 ± 11.5 years old, with the sample consisting mainly of married women (56.5%), socioeconomic class C2 or D / E (78.2%) and years of education up to 8 years (69.5%). The presence of horizontal bone loss (p<0.001) and bilateral pneumatization of the maxillary sinus (p=0.015) were significant data. The mean number of absent teeth considering all subjects was 23.17±9.7, being statistically significant (p<0.001). In relation to age, the mean number of missing teeth was higher in individuals over 65 years old (p=0.048). Reduced salivary flow was observed in 78.3% of the patients. In a bivariate analysis, considering the outcome variables missing teeth and reduced salivary flow, it was observed that economic class (p<0.001), family income (0.037) and maxillary sinus pneumatization (0.032) were statistically significant. CONCLUSIONS: In brief, patients with SS showed severe teeth loss, reduced salivary flow, and low educational status. This study addressed important aspects regarding oral findings in SS and highlighted the importance of researches in oral medicine.

Removal of textile dyes and metallic ions using polyelectrolytes and macroelectrolytes containing sulfonic acid groups.

This work reports the removal of textile dyes and metallic ions by means of adsorption and coagulation-flocculation using two polyelectrolytes and two macroelectrolytes containing sulfonic acid groups. The adsorption of textile dyes was studied in aqueous solutions containing cationic dyes and in wastewater containing a vat dye. Also, removal of vat and naphthol dyes was studied using the process of coagulation-flocculation. The results show these materials possess elevated adsorption capacity, and they accomplished removal rates above 97% in aqueous solutions. The removal of the vat dye improved the quality of the wastewater notably, and an uncolored effluent was obtained at the end of the treatment. The treatment using adsorption decreased the values for coloration, conductivity, suspended solids, and pH. The removal of vat and naphthol dyes by means of coagulation-flocculation was studied as well, and removal rates of 90% were obtained. The polyelectrolytes and macroelectrolytes also proved effective in the adsorption of metallic ions in wastewater. The treatment using adsorption accomplished high removal rates of metallic ions, and it showed greater selectivity towards Cu(2+), Fe(3+) and Pb(2+). A decrease in the content of solids as well as the values for COD and conductivity was observed in the wastewater as well. The analyses of FT-IR indicated that cationic dyes and metallic ions were chemisorbed by means of ionic exchange.

Practical application of brief cognitive tests.

INTRODUCTION: Brief cognitive tests (BCT) may help detect cognitive impairment (CI) in the clinical setting. Several BCT have been developed and/or validated in our country, but we lack specific recommendations for use. DEVELOPMENT: Review of studies on the diagnostic accuracy of BCT for CI, using studies conducted in Spain with BCT which take less than 20 min. We provide recommendations of use based on expert consensus and established on the basis of BCT characteristics and study results. CONCLUSION: The Fototest, the Memory Impairment Screen (MIS) and the Mini-Mental State Examination (MMSE) are the preferred options in primary care; other BCT (Clock Drawing Test [CDT], test of verbal fluency [TVF]) may also be administered in cases of negative results with persistent suspected CI or concern (stepwise approach). In the specialised care setting, a systematic assessment of the different cognitive domains should be conducted using the Montreal Cognitive Assessment, the MMSE, the Rowland Universal Dementia Assessment, the Addenbrooke's Cognitive Examination, or by means of a stepwise or combined approach involving more simple tests (CDT, TVF, Fototest, MIS, Memory Alteration Test, Eurotest). Associating an informant questionnaire (IQ) with the BCT is superior to the BCT alone for the detection of CI. The choice of instruments will depend on the patient's characteristics, the clinician's experience, and available time. The BCT and IQ must reinforce - but never substitute - clinical judgment, patient-doctor communication, and inter-professional dialogue.

Hypolipidemic effects of Solidago chilensis hydroalcoholic extract and its major isolated constituent quercetrin in cholesterol-fed rats.

CONTEXT: Despite several studies on the effects of Solidago chilensis Meyen (Asteraceae), the phytochemical and hypolipidemic properties remain underappreciated. OBJECTIVE: This study evaluates the hypolipidemic and antioxidant effects of hydroalcoholic extract (HE) and quercetrin from S. chilensis aerial parts in cholesterol-fed rats. MATERIALS AND METHODS: The HE was analyzed by high-performance liquid chromatography, followed by quercetrin isolation. Hypercholesterolemic rats (1% cholesterol and 0.5% cholic acid for 15 d) were treated with HE (150, 300, and 600 mg/kg p.o.; n = 6), simvastatin (4 mg/kg p.o.; n = 6), or quercetrin (10 mg/kg p.o.; n = 6) once a day for 30 d. During this period, a high-cholesterol diet was maintained until the 30th day of treatment. RESULTS: Rats treated with HE (150, 300, and 600 mg/kg) and quercetrin showed decreased serum levels of total cholesterol (-19.9, -27.5, -31.0, and -39.4%), lipoprotein-cholesterol (-36.0, -37.5, -43.3, and -59.4%), and triacylglycerides (-15.6, -23.5, -29.8, and -27.2%) when compared with the control group similar to simvastatin. Moreover, treatment with HE and quercetrin decreased hepatic 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase activity (35.1% on average) and increased fecal cholesterol levels (38.2% on average). DISCUSSION AND CONCLUSIONS: Our results suggest that hypolipidemic effects of HE are associated with it modulating the activity of HMG-CoA reductase and its interference in the reabsorption and/or excretion of intestinal lipids. Solidago chilensis and its main constituent, quercetrin, may thus be effective as cholesterol-lowering agents and in preventing atherosclerosis.

Challenges and opportunities in polymer technology applied to veterinary medicine.

An important frontier in the administration of therapeutic drugs to veterinary species is the use of different polymers as drug delivery platforms. The usefulness of polymers as platforms for the administration of pharmaceutical and agricultural agents has been clearly recognized in the recent decades. The chemical versatility of polymers and the wide range of developed controlled-release strategies enhance the possibilities for the formulation of active molecules. In particular, the veterinary area offers opportunities for the development of novel controlled-release drug delivery technologies adapted to livestock or companion animal health needs. In some cases, it also allows to improve profitability in meat production or to meet the safety criteria related to drug residues. A number of factors affect the selection of polymers and subsequent properties of the controlled-release drug delivery system. However, their selection also dictates the release kinetics of the drug from the delivery system. Such choices are therefore crucial as they affect the success and potential of the delivery system for achieving the therapeutic goals of the veterinarian. It is the intention of this review to give an overview of the most relevant polymers, which are used or have been tested as drug delivery release rate modifiers in the veterinary field. The article highlights some recent developments focusing on their advantages and applications and analyzes the future direction of the scientific and technological advancements in this area.

Comparison of a new chemiluminescent immunoassay for von Willebrand factor activity with the ristocetin cofactor-induced platelet agglutination method.

Measuring von Willebrand factor (VWF) activity is essential for the diagnosis of von Willebrand disease (VWD). The VWF activity is usually assessed based on measurement of the ristocetin cofactor (VWF:RCo). However, that test is technically challenging and has high intra- and inter-assay variabilities. A new automated chemiluminescent immunoassay VWF activity has recently become commercially available (HemosIL AcuStar von Willebrand Factor Ristocetin Cofactor Activity). The main objective of this study was to evaluate this new method and to compare it with the VWF:RCo assay as the reference method. We studied 91 samples, 18 healthy volunteers samples and 73 samples from patients (VWF:RCo level <50 IU dL(-1) ): 29 type 1 VWD, 13 type 2A, 5 type 2B, 5 type 2M, 3 type 2N, 5 type 3, 4 type 3 under treatment, 5 type 3 carriers and 4 samples with other pathologies. The HemosIL AcuStar VWF:RCo assay was 96% sensitive and 100% specific for detecting VWF abnormalities. The good analytical performance, and the sensitivity and specificity of HemosIL AcuStar VWF:RCo to detect VWF deficiency renders it a suitable method for VWD screening.

Textile dyes removal from aqueous solution using Opuntia ficus-indica fruit waste as adsorbent and its characterization.

For this research, three different adsorbents, one untreated and two chemically activated, were prepared from Opuntia ficus-indica fruit waste. By the construction of adsorption isotherms, its adsorption capabilities and the viability of its use in the removal of textile basic and direct type dyes were determined. It was found that the adsorbent with the most adsorption capacity for basic dyes was the one activated with NaClO, and, for direct dyes, it was the one activated with NaOH. Langmuir and Freundlich equations isotherms were applied for the analysis of the experimental data. It was found that the Freundlich model best described the adsorption behavior. The adsorption capacity was improved when the pH of the dye solution had an acid value. The specific surface area of the adsorbents was calculated by means of methylene blue adsorption at 298 K to stay within a range between 348 and 643 m(2) g(-1). The FTIR spectroscopic characterization technique, the SEM, the point of zero charge, and the elemental analysis show the chemical and physical characteristics of the studied adsorbents, which confirm the adsorption results obtained.

Tuberculosis: finding a new potential antimycobacterium derivative in a aldehyde-arylhydrazone-oxoquinoline series.

Tuberculosis (TB) is a contagious disease caused by Mycobacterium tuberculosis, which remains a serious public health problem. The emergence of resistant bacterial strains has continuously increased and new treatment options are currently in need. In this work, we identified a new potential aldehyde-arylhydrazone-oxoquinoline derivative (4e) with interesting chemical structural features that may be important for designing new anti-TB agents. This 1-ethyl-N'-[(1E)-(5-nitro-2-furyl)methylene]-4-oxo-1,4-dihydroquinoline-3-carbohydrazide (4e) presented an in vitro active profile against M. tuberculosis H37Rv strain (minimum inhibitory concentration, MIC = 6.25 µg/mL) better than other acylhydrazones described in the literature (MIC = 12.5 µg/mL) and close to other antitubercular agents currently on the market. The theoretical analysis showed the importance of several structural features that together with the 5-nitro-2-furyl group generated this active compound (4e). This new compound and the analysis of its molecular properties may be useful for designing new and more efficient antibacterial drugs.

Magnetic refrigeration material operating at a full temperature range required for hydrogen liquefaction.

Magnetic refrigeration (MR) is a key technique for hydrogen liquefaction. Although the MR has ideally higher performance than the conventional gas compression technique around the hydrogen liquefaction temperature, the lack of MR materials with high magnetic entropy change in a wide temperature range required for the hydrogen liquefaction is a bottle-neck for practical applications of MR cooling systems. Here, we show a series of materials with a giant magnetocaloric effect (MCE) in magnetic entropy change (-∆Sm > 0.2 J cm-3K-1) in the Er(Ho)Co2-based compounds, suitable for operation in the full temperature range required for hydrogen liquefaction (20-77 K). We also demonstrate that the giant MCE becomes reversible, enabling sustainable use of the MR materials, by eliminating the magneto-structural phase transition that leads to deterioration of the MCE. This discovery can lead to the application of Er(Ho)Co2-based alloys for the hydrogen liquefaction using MR cooling technology for the future green fuel society.

Acetylcholinesterase inhibitory activity of uleine from Himatanthus lancifolius.

Application of acetylcholinesterase (AChE) inhibitors is the primary treatment for Alzheimer's disease. Alkaloids, such as physostigmine, galanthamine, and huperzine A, play an important role as AChE inhibitors. The aim of this work was to evaluate Himatanthus lancifolius (Muell. Arg.) Woodson, a Brazilian species of Apocynaceae, and its main indole alkaloid uleine, in order to identify new AChE inhibitors. The plant fluid extract, fractions, and uleine were tested for AChE inhibitory activity using Ellman's colorimetric method for thin-layer chromatography (TLC), 96-well microplates, and also Marston's TLC colorimetric method. Both TLC assays showed similar results. At 5 mg/mL, the fluid extract inhibited the AChE enzyme by (50.71 +/- 8.2)%. The ethyl acetate fraction exhibited the highest level of AChE inhibition, followed by the dichloromethane fraction. The isolated alkaloid uleine displayed an IC50 value of 0.45 microM.

Factors associated with the desire for orthodontic treatment among Brazilian adolescents and their parents.

BACKGROUND: In the period of adolescence physical appearance takes on significant importance in the construction of personal identity, including one's relationship with one's own body. A variety of social, cultural, psychological and personal factors influences the self-perception of dental appearance and the decision to undergo orthodontic treatment. Adolescents who seek orthodontic treatment are concerned with improving their appearance and social acceptance. The aim of the present study was to determine factors associated to the desire for orthodontic treatment among Brazilian adolescents and their parents. METHODS: The sample consisted of 403 subjects aged 14 to 18 years, selected randomly from a population of 182,291 schoolchildren in the same age group. The outcome variable "desire for orthodontic treatment" was assessed through a questionnaire. Self-perception of dental aesthetics was assessed using the Oral Aesthetic Subjective Impact Scale (OASIS) and the Dental Aesthetic Index (DAI) was used for clinical assessment. Statistical analysis involved the chi-square test as well as both simple and multiple logistic regression analyses. RESULTS: The majority (78%) of the Brazilian adolescents desired orthodontic treatment and 69% of the parents reported that their children were not in orthodontic treatment due to the high costs involved. There was significant association (p < or = 0.05) between the desire for orthodontic treatment and most types of malocclusion. However, there was no significant association between the desire for orthodontic treatment and the variables gender and age. CONCLUSIONS: The following were considered factors associated to the desire for treatment: upper anterior crowding > or = 2 mm and parents' perception of their child's need for treatment.

Aesthetic impact of malocclusion in the daily living of Brazilian adolescents.

OBJECTIVE: The aim of the present study was to determine the biopsychosocial impact of malocclusion on the daily living of Brazilian adolescents (14 to 18 years of age) through normative and subjective records and identify factors directly involved in the self-perception of malocclusions. DESIGN: Cross-sectional. SETTING: Public and private schools in the city of Belo Horizonte, Brazil. SUBJECTS AND METHODS: The sample was made up of 403 adolescents, with no prior history of orthodontic treatment, who were selected randomly from a population of 182,291 students in the same age range. The oral impact of malocclusion was assessed using the Oral Impact on Daily Performance (OIDP), whereas clinical criteria were assessed using the Dental Aesthetic Index (DAI). Self-perception of dental aesthetics was assessed using the Oral Aesthetic Subjective Impact Scale (OASIS) and self-esteem was assessed using the Global Negative Self-Evaluation (GSE) scale. Other variables were assessed using questionnaires. The chi-square test, simple and multiple logistic regression analyses were used for the statistical analysis. RESULTS: Ninety five adolescents (24%) reported feeling embarrassed to smile (aesthetic impact). A logistic regression suggested that the following variables were directly involved in the self-perception of malocclusion: upper anterior crowding > or = 2 mm (P=0.009), median diastema > or = 2 mm (P=0.040), normative treatment need (highly desirable) (P<0.001) and low economic level (P<0.001). CONCLUSION: Negative repercussions on daily living were found in Brazilian adolescents with malocclusions affecting anterior dental aesthetics.

Geodesic Distances in Probabilistic Spaces for Patch-Based Ultrasound Image Processing.

Many recent ultrasound image processing methods are based on patch comparison, such as filtering and segmentation. Identifying similar patches in noise-corrupted images is a key factor for the performance of these methods. While the Euclidean distance is ideal to handle the patch comparison under additive Gaussian noise, finding good measures to compare patches corrupted by multiplicative noise is still an open research. In this paper, we deduce several new geodesic distances, arising from parametric probabilistic spaces, and suggest them as similarity measures to process RF and log-compressed ultrasound images in patch-based methods. We provide practical examples using these measures in the fields of ultrasound image filtering and segmentation, with results that confirm the potential of the technique.

Patch similarity in ultrasound images with hypothesis testing and stochastic distances.

Patch-based techniques have been largely applied to process ultrasound (US) images, with applications in various fields as denoising, segmentation, and registration. An important aspect of the performance of these techniques is how to measure the similarity between patches. While it is usual to base the similarity on the Euclidean distance when processing images corrupted by additive Gaussian noise, finding measures suitable for the multiplicative nature of the speckle in US images is still an open research. In this work, we propose new stochastic distances based on the statistical characteristics of speckle in US. Additionally, we derive statistical measures to compose hypothesis tests that allow a quantitative decision on the patch similarity of US images. Good results with experiments in denoising, segmentation and selecting similar patches confirm the potential of the proposed measures.

Bayesian pharmacokinetic-guided prophylaxis with recombinant factor VIII in severe or moderate haemophilia A.

INTRODUCTION: Personalised pharmacokinetics (PK) using Bayesian analysis with limited sampling is assumed to help to optimise prophylaxis in haemophilia A (HA) patients. MATERIALS AND METHODS: Our prospective, observational study analysed the influence of PK parameters on clinical variables (bleeding rates, joint status, adherence, and consumption) using myPKFiT® in a cohort of twenty-one severe and moderate HA patients on prophylaxis with recombinant FVIII (Advate®) in two periods of one year, the first before PK-based tailoring and the second after PK-guided prophylaxis. Intra-individual and inter-individual coefficients of variation (CV) of half-life (t1/2) were calculated. RESULTS: A total of 73 PK estimations were performed in both periods, resulting in 17.2% inter-individual CV in mean t1/2, and 4.9% intra-individual CV. Before PK-based tailoring a significant association between joint bleeds and t1/2 was found (P = 0.010), especially in patients with short t1/2. This finding was reproduced (P = 0.013) after withdrawal of two patients with bleeding phenotype related to their advanced arthropathy but normal t1/2 and trough levels. Patients with joint bleeds weighed less (P = 0.039) and required higher doses (P = 0.032) than patients with zero joint bleeds. These associations were not observed in the second period after the adoption of PK-guided prophylaxis. There were no differences between the two periods, although a tendency to fewer spontaneous bleeds was suggested after PK-based tailoring. CONCLUSIONS: PK-guided prophylaxis facilitates an adequate level of bleeding control in patients with HA, maintaining clinical variables and patient convenience in an integrative manner, without increasing FVIII consumption.