RESUMO
A defining pathological feature of most neurodegenerative diseases is the assembly of proteins into amyloid that form disease-specific structures1. In Alzheimer's disease, this is characterized by the deposition of ß-amyloid and tau with disease-specific conformations. The in situ structure of amyloid in the human brain is unknown. Here, using cryo-fluorescence microscopy-targeted cryo-sectioning, cryo-focused ion beam-scanning electron microscopy lift-out and cryo-electron tomography, we determined in-tissue architectures of ß-amyloid and tau pathology in a postmortem Alzheimer's disease donor brain. ß-amyloid plaques contained a mixture of fibrils, some of which were branched, and protofilaments, arranged in parallel arrays and lattice-like structures. Extracellular vesicles and cuboidal particles defined the non-amyloid constituents of ß-amyloid plaques. By contrast, tau inclusions formed parallel clusters of unbranched filaments. Subtomogram averaging a cluster of 136 tau filaments in a single tomogram revealed the polypeptide backbone conformation and filament polarity orientation of paired helical filaments within tissue. Filaments within most clusters were similar to each other, but were different between clusters, showing amyloid heterogeneity that is spatially organized by subcellular location. The in situ structural approaches outlined here for human donor tissues have applications to a broad range of neurodegenerative diseases.
Assuntos
Doença de Alzheimer , Peptídeos beta-Amiloides , Encéfalo , Microscopia Crioeletrônica , Tomografia com Microscopia Eletrônica , Placa Amiloide , Proteínas tau , Humanos , Masculino , Camundongos , Doença de Alzheimer/patologia , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/química , Peptídeos beta-Amiloides/metabolismo , Peptídeos beta-Amiloides/ultraestrutura , Autopsia , Encéfalo/metabolismo , Encéfalo/patologia , Encéfalo/ultraestrutura , Vesículas Extracelulares/metabolismo , Vesículas Extracelulares/química , Vesículas Extracelulares/ultraestrutura , Placa Amiloide/metabolismo , Placa Amiloide/patologia , Placa Amiloide/química , Placa Amiloide/ultraestrutura , Proteínas tau/química , Proteínas tau/metabolismo , Proteínas tau/ultraestruturaRESUMO
BACKGROUND: Docosahexaenoic acid (DHA) is a component of neural tissue. Because its accretion into the brain is greatest during the final trimester of pregnancy, infants born before 29 weeks' gestation do not receive the normal supply of DHA. The effect of this deficiency on subsequent cognitive development is not well understood. METHODS: We assessed general intelligence at 5 years in children who had been enrolled in a trial of neonatal DHA supplementation to prevent bronchopulmonary dysplasia. In the previous trial, infants born before 29 weeks' gestation had been randomly assigned in a 1:1 ratio to receive an enteral emulsion that provided 60 mg of DHA per kilogram of body weight per day or a control emulsion from the first 3 days of enteral feeds until 36 weeks of postmenstrual age or discharge home, whichever occurred first. Children from 5 of the 13 centers in the original trial were invited to undergo assessment with the Wechsler Preschool and Primary Scale of Intelligence (WPPSI) at 5 years of corrected age. The primary outcome was the full-scale intelligence quotient (FSIQ) score. Secondary outcomes included the components of WPPSI. RESULTS: A total of 1273 infants underwent randomization in the original trial; of the 656 surviving children who had undergone randomization at the centers included in this follow-up study, 480 (73%) had an FSIQ score available - 241 in the DHA group and 239 in the control group. After imputation of missing data, the mean (±SD) FSIQ scores were 95.4±17.3 in the DHA group and 91.9±19.1 in the control group (adjusted difference, 3.45; 95% confidence interval, 0.38 to 6.53; P = 0.03). The results for secondary outcomes generally did not support that obtained for the primary outcome. Adverse events were similar in the two groups. CONCLUSIONS: In infants born before 29 weeks' gestation who had been enrolled in a trial to assess the effect of DHA supplementation on bronchopulmonary dysplasia, the use of an enteral DHA emulsion until 36 weeks of postmenstrual age was associated with modestly higher FSIQ scores at 5 years of age than control feeding. (Funded by the Australian National Health and Medical Research Council and Nu-Mega Ingredients; N3RO Australian New Zealand Clinical Trials Registry number, ACTRN12612000503820.).
Assuntos
Displasia Broncopulmonar , Cognição , Ácidos Docosa-Hexaenoicos , Recém-Nascido Prematuro , Inteligência , Criança , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Austrália , Displasia Broncopulmonar/prevenção & controle , Suplementos Nutricionais/efeitos adversos , Ácidos Docosa-Hexaenoicos/deficiência , Ácidos Docosa-Hexaenoicos/farmacologia , Ácidos Docosa-Hexaenoicos/uso terapêutico , Emulsões , Seguimentos , Recém-Nascido Prematuro/crescimento & desenvolvimento , Inteligência/efeitos dos fármacos , Nutrição Enteral , Escalas de Wechsler , Cognição/efeitos dos fármacosRESUMO
BACKGROUND: In 2009, the Australian government mandated the fortification of bread salt with iodine. In 2010, pregnant and lactating women were also advised to take an iodine-containing supplement. Our assessment of this policy in an iodine-sufficient population showed that children whose mothers were in the highest and lowest quartiles of iodine intake performed more poorly on early childhood tests of cognition and language than those in the second quartile. However, we did not quantify the iodine intake associated with optimal neurodevelopment. OBJECTIVES: The aim was to establish the iodine intake range in pregnancy associated with optimal child neurodevelopment. METHODS: A prospective cohort study of pregnant women and their young children (n = 699). Iodine intake was assessed by a validated food frequency questionnaire at 16 and 28 wk of gestation. Child neurodevelopment at 18 mo of age was measured using the Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III). The relationship between average iodine intake during pregnancy and child neurodevelopment was assessed using linear regression with fractional polynomials and adjustment for confounders. RESULTS: Mean (SD) iodine intake was similar at study entry and 28 wk, 308 (120) µg/d, with 82% of women taking iodine supplements at study entry. The relationship between iodine intake during pregnancy and Bayley-III cognitive and language scores was curvilinear (P = 0.001 and P = 0.004, respectively), with the lowest Bayley-III scores observed at lower and higher iodine intakes. The inflection point that drove the association between lower iodine intake in pregnancy and poorer child neurodevelopment scores was around 185 µg/d; for the higher pregnancy iodine intakes, language and cognitive scores were negatively affected from â¼350 µg/d to 370 µg/d, respectively. Higher iodine intakes were being driven by supplement use. CONCLUSIONS: Targeted, not blanket, iodine supplementation may be needed for pregnant women with low-iodine intake from food.
Assuntos
Iodo , Lactação , Lactente , Humanos , Feminino , Gravidez , Pré-Escolar , Estudos Prospectivos , Austrália , Suplementos NutricionaisRESUMO
BACKGROUND: Iron deficiency (ID) is the most common nutritional deficiency affecting young children. Serum ferritin concentration is the preferred biomarker for measuring iron status because it reflects iron stores; however, blood collection can be distressing for young children and can be logistically difficult. A noninvasive means to measure iron status would be attractive to either diagnose or screen for ID in young children. OBJECTIVES: This study aimed to determine the correlation between urinary and serum ferritin concentrations in young children; to determine whether correcting urinary ferritin for creatinine and specific gravity improves the correlation; and to determine a urine ferritin cut point to predict ID. METHODS: Validation study was conducted using paired serum and urine collected from 3-y-old children (n = 142) participating in a longitudinal birth cohort study: the ORIGINS project in Perth, Western Australia. We calculated the sensitivity, specificity, positive, and negative predictive values of urinary ferritin amount in identifying those with ID at the clinical cut point used by the World Health Organization (serum ferritin concentration of <12 ng/mL). RESULTS: Urine ferritin, corrected for creatinine, correlated moderately with serum ferritin [r = 0.53 (0.40-0.64)] and performed well in predicting those with ID (area under the curve: 0.85; 95% confidence interval: 0.75, 0.94). Urine ferritin <2.28 ng/mg creatinine was sensitive (86%) and specific (77%) in predicting ID and had a high negative predictive value of 97%; however, the positive predictive value was low (40%) owing to the low prevalence of ID in the sample (16%). CONCLUSIONS: Urine ferritin shows good diagnostic performance for ID. This noninvasive biomarker maybe a useful screening tool to exclude ID in healthy young children; however, further research is needed in other populations.
RESUMO
To obtain valid inference following stratified randomisation, treatment effects should be estimated with adjustment for stratification variables. Stratification sometimes requires categorisation of a continuous prognostic variable (eg, age), which raises the question: should adjustment be based on randomisation categories or underlying continuous values? In practice, adjustment for randomisation categories is more common. We reviewed trials published in general medical journals and found none of the 32 trials that stratified randomisation based on a continuous variable adjusted for continuous values in the primary analysis. Using data simulation, this article evaluates the performance of different adjustment strategies for continuous and binary outcomes where the covariate-outcome relationship (via the link function) was either linear or non-linear. Given the utility of covariate adjustment for addressing missing data, we also considered settings with complete or missing outcome data. Analysis methods included linear or logistic regression with no adjustment for the stratification variable, adjustment for randomisation categories, or adjustment for continuous values assuming a linear covariate-outcome relationship or allowing for non-linearity using fractional polynomials or restricted cubic splines. Unadjusted analysis performed poorly throughout. Adjustment approaches that misspecified the underlying covariate-outcome relationship were less powerful and, alarmingly, biased in settings where the stratification variable predicted missing outcome data. Adjustment for randomisation categories tends to involve the highest degree of misspecification, and so should be avoided in practice. To guard against misspecification, we recommend use of flexible approaches such as fractional polynomials and restricted cubic splines when adjusting for continuous stratification variables in randomised trials.
Assuntos
Ensaios Clínicos Controlados Aleatórios como Assunto , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto/estatística & dados numéricos , Simulação por Computador , Modelos Lineares , Interpretação Estatística de Dados , Modelos Logísticos , Distribuição AleatóriaRESUMO
The Cassini mission provided evidence for a global subsurface ocean and ongoing hydrothermal activity on Enceladus, based on results from Cassini's mass spectrometers. Laboratory simulations of hydrothermal conditions on icy moons are needed to further constrain the composition of ejected ice grains containing hydrothermally altered organic material. Here, we present results from our newly established facility to simulate the processing of ocean material within the temperature range 80-150°C and the pressure range 80-130 bar, representing conditions suggested for the water-rock interface on Enceladus. With this new facility, we investigate the hydrothermal processing of triglycine (GGG) peptide and, for the first time, analyse the extracted samples using laser-induced liquid beam ion desorption (LILBID) mass spectrometry, a laboratory analogue for impact ionization mass spectrometry of ice grains in space. We outline an approach to elucidate hydrothermally processed GGG in ice grains ejected from icy moons based on characteristic differences between GGG anion and cation mass spectra. These differences are linked to hydrothermal processing and thus provide a fingerprint of hydrothermal activity on extraterrestrial bodies. These results will serve as important guidelines for biosignatures potentially obtained by a future Enceladus mission and the SUrface Dust Analyzer (SUDA) instrument onboard Europa Clipper. This article is part of the theme issue 'Dust in the Solar System and beyond'.
RESUMO
BACKGROUND: Stillbirth rates remain a global priority and in Australia, progress has been slow. Risk factors of stillbirth are unique in Australia due to large areas of remoteness, and limited resource availability affecting the ability to identify areas of need and prevalence of factors associated with stillbirth. This retrospective cohort study describes lifestyle and sociodemographic factors associated with stillbirth in South Australia (SA), between 1998 and 2016. METHODS: All restigered births in SA between 1998 ad 2016 are included. The primary outcome was stillbirth (birth with no signs of life ≥ 20 weeks gestation or ≥ 400 g if gestational age was not reported). Associations between stillbirth and lifestyle and sociodemographic factors were evaluated using multivariable logistic regression and described using adjusted odds ratios (aORs). RESULTS: A total of 363,959 births (including 1767 stillbirths) were included. Inadequate antenatal care access (assessed against the Australian Pregnancy Care Guidelines) was associated with the highest odds of stillbirth (aOR 3.93, 95% confidence interval (CI) 3.41-4.52). Other factors with important associations with stillbirth were plant/machine operation (aOR, 1.99; 95% CI, 1.16-2.45), birthing person age ≥ 40 years (aOR, 1.92; 95% CI, 1.50-2.45), partner reported as a pensioner (aOR, 1.83; 95% CI, 1.12-2.99), Asian country of birth (aOR, 1.58; 95% CI, 1.19-2.10) and Aboriginal/Torres Strait Islander status (aOR, 1.50; 95% CI, 1.20-1.88). The odds of stillbirth were increased in regional/remote areas in association with inadequate antenatal care (aOR, 4.64; 95% CI, 2.98-7.23), birthing age 35-40 years (aOR, 1.92; 95% CI, 1.02-3.64), Aboriginal and/or Torres Strait Islander status (aOR, 1.90; 95% CI, 1.12-3.21), paternal occupations: tradesperson (aOR, 1.69; 95% CI, 1.17-6.16) and unemployment (aOR, 4.06; 95% CI, 1.41-11.73). CONCLUSION: Factors identified as independently associated with stillbirth odds include factors that could be addressed through timely access to adequate antenatal care and are likely relevant throughout Australia. The identified factors should be the target of stillbirth prevention strategies/efforts. SThe stillbirth rate in Australia is a national concern. Reducing preventable stillbirths remains a global priority.
Assuntos
Estilo de Vida , Natimorto , Humanos , Natimorto/epidemiologia , Natimorto/etnologia , Estudos Retrospectivos , Feminino , Austrália do Sul/epidemiologia , Fatores de Risco , Gravidez , Adulto , Cuidado Pré-Natal/estatística & dados numéricos , Fatores Sociodemográficos , Adulto Jovem , Modelos Logísticos , Fatores Socioeconômicos , Acessibilidade aos Serviços de Saúde/estatística & dados numéricosRESUMO
BACKGROUND: Ideal target limb alignment remains a debated topic in total knee arthroplasty (TKA). We aimed to determine the effect of limb alignment correction on patient-reported outcomes and knee range of motion (ROM) following TKA. METHODS: In this retrospective analysis, patients (N = 409) undergoing primary TKA at a single institution were studied. Using full leg-length radiographs, limb alignment was measured preoperatively and postoperatively. Patients were categorized by preoperative (Preop) alignment (varus > 0°; valgus < 0°). Preop varus patients were then divided as follows based on postoperative alignment: neutral (VAR-NEUT, 0°± 2), remaining in varus (VAR-rVAR, ≥3°), and cross-over to valgus (VAR-CO, ≤-3°). Similarly, Preop valgus patients were divided as follows for postoperative alignment: neutral (VAL-NEUT, 0°± 2), remaining in valgus (VAL-rVAL, ≤-3°), and cross-over to varus (VAL-CO, ≥3°). The Knee Injury and Osteoarthritis Outcome Score for Joint Replacement survey scores were collected at preoperatively as well as at 6 weeks, 3, 6, and 12 months postoperatively. Knee ROM was collected at 2 weeks, 6 to 12 weeks, and >6 months postoperatively. An analysis of variance repeated on time followed by a Bonferroni post hoc test was used to compare outcomes for the postoperative alignment subgroups. RESULTS: Preop Varus patients: Those in the VAR-CO group (overcorrected to -4.03° ± 1.95valgus) were observed to have lower Knee Injury and Osteoarthritis Outcome Score for Joint Replacement scores at 3, 6, and 12 months postoperatively compared to those in the NEUT group (P < .05). This finding was paired with reduced ROM at 6 to 12 weeks postoperatively in the VAR-CO group compared to VAR-NEUT and VAR-rVAR (P < .05). Preop Valgus patients: Those in the VAL-rVal group (left in -4.39° ± 1.39valgus) were observed to have reduced knee flexion at 6 to 12 weeks postoperatively compared to VAL-NEUT and VAL-CO. CONCLUSIONS: These findings indicate that postoperative valgus alignment via either crossing over to valgus (VAR-CO) or remaining in valgus (VAL-rVAL) alignment may result in less preferable outcomes than correction to neutral or slightly varus alignment.
Assuntos
Artroplastia do Joelho , Articulação do Joelho , Amplitude de Movimento Articular , Humanos , Artroplastia do Joelho/métodos , Estudos Retrospectivos , Feminino , Masculino , Idoso , Pessoa de Meia-Idade , Articulação do Joelho/cirurgia , Articulação do Joelho/fisiopatologia , Articulação do Joelho/diagnóstico por imagem , Osteoartrite do Joelho/cirurgia , Mau Alinhamento Ósseo/prevenção & controle , Mau Alinhamento Ósseo/diagnóstico por imagem , Radiografia , Idoso de 80 Anos ou mais , Medidas de Resultados Relatados pelo Paciente , Resultado do TratamentoRESUMO
BACKGROUND: Intraosseous (IO) administration of vancomycin at the time of total knee arthroplasty (TKA) has been shown to be safer and more effective than intravenous (IV) administration at preventing early periprosthetic joint infection. Previous studies have relied on tourniquet inflation to enhance local tissue concentrations and mitigate systemic release. METHODS: A single-blinded, randomized clinical trial was performed on 20 patients (10 IV, 10 IO) undergoing primary TKA. The control (IV) group received weight-dosed vancomycin approximately 1 hour prior to the incision and weight-dosed cefazolin immediately prior to the incision. The interventional (IO) group received weight-dosed cefazolin immediately prior to the incision and 500 mg of vancomycin delivered via the IO technique at the time of the incision. Systemic samples for vancomycin levels were taken prior to the incision and at closure. During the procedure, tissue samples were taken from the distal femur, proximal tibia, and suprapatellar synovium. There were no differences in patient demographics or changes in serum creatinine from preoperative to postoperatively between groups. RESULTS: Significant differences in systemic vancomycin levels (ug/mL) were found at the start of the case (IV = 27.9 ± 4.9 versus IO = 0 ± 0, P = .0004) and at the end of the case (IV = 19.6 ± 2.6 versus IO = 7.8 ± 1.0, P = .001). No significant differences were seen in the average vancomycin concentration in the distal femur (IV = 61.0 ± 16.0 versus IO = 66.2 ± 12.3, P = .80), proximal tibia (IV = 52.8 ± 13.5 versus IO = 57.1 ± 17.0, P = .84), or suprapatellar synovial tissue (IV = 10.7 ± 5.3 versus IO = 9.0 ± 3.3, P = .80). There were no complications associated with vancomycin administration in either group. CONCLUSIONS: This study demonstrates the utility of IO vancomycin in tourniquetless TKA with similar local tissue and significantly lower systemic concentrations than IV administration. LEVEL OF EVIDENCE: Level 1 therapeutic randomized trial.
RESUMO
Pregnant women are advised to take folic acid (FA) supplements before conception and during the first trimester of pregnancy. Many women continue FA supplementation throughout pregnancy, and concerns have been raised about associations between excessive FA intake and adverse maternal and child health outcomes. Unmetabolized folic acid (UMFA) is found in serum after high FA intakes and is proposed as a biomarker for excessive FA intake. We aimed to determine if removing FA from prenatal micronutrient supplements after 12 weeks of pregnancy reduces serum UMFA concentrations at 36 weeks gestation. In this double-blind, randomized controlled trial conducted in South Australia, 103 women with a singleton pregnancy were randomly assigned at 12-16 weeks gestation to take a micronutrient supplement containing no FA or 800 µg/day FA from enrollment until 36 weeks gestation. Ninety women (0 µg/day FA n = 46; 800 µg/day FA n = 44) completed the study. Mean, UMFA concentration was lower in the women randomized to the 0 µg/day group compared to the 800 µg/day FA group, 0.6 ± 0.7 and 1.4 ± 2.7 nmol/L, respectively. The adjusted mean difference (95% CI) in UMFA between the groups was [-0.85 (-1.62, -0.08) nmol/L, p = 0.03]. Maternal serum and red blood cell folate concentrations were lower in the 0 µg/day FA group than in the 800 µg/day group (median 23.2 vs. 49.3 and 1335 vs. 1914 nmol/L, respectively; p < 0.001). Removing FA at 12-16 weeks gestation from prenatal micronutrient supplements reduced the concentration of UMFA at 36 weeks gestation.
RESUMO
BACKGROUND: The meningococcal group B vaccine 4CMenB is a new, recombinant protein-based vaccine that is licensed to protect against invasive group B meningococcal disease. However, its role in preventing transmission and, therefore, inducing population (herd) protection is uncertain. METHODS: We used cluster randomization to assign, according to school, students in years 10 to 12 (age, 15 to 18 years) in South Australia to receive 4CMenB vaccination either at baseline (intervention) or at 12 months (control). The primary outcome was oropharyngeal carriage of disease-causing Neisseria meningitidis (group A, B, C, W, X, or Y) in students in years 10 and 11, as identified by polymerase-chain-reaction assays for PorA (encoding porin protein A) and N. meningitidis genogroups. Secondary outcomes included carriage prevalence and acquisition of all N. meningitidis and individual disease-causing genogroups. Risk factors for carriage were assessed at baseline. RESULTS: A total of 237 schools participated. During April through June 2017, a total of 24,269 students in years 10 and 11 and 10,220 students in year 12 were enrolled. At 12 months, there was no difference in the prevalence of carriage of disease-causing N. meningitidis between the vaccination group (2.55%; 326 of 12,746) and the control group (2.52%; 291 of 11,523) (adjusted odds ratio, 1.02; 95% confidence interval [CI], 0.80 to 1.31; P = 0.85). There were no significant differences in the secondary carriage outcomes. At baseline, the risk factors for carriage of disease-causing N. meningitidis included later year of schooling (adjusted odds ratio for year 12 vs. year 10, 2.75; 95% CI, 2.03 to 3.73), current upper respiratory tract infection (adjusted odds ratio, 1.35; 95% CI, 1.12 to 1.63), cigarette smoking (adjusted odds ratio, 1.91; 95% CI, 1.29 to 2.83), water-pipe smoking (adjusted odds ratio, 1.82; 95% CI, 1.30 to 2.54), attending pubs or clubs (adjusted odds ratio, 1.54; 95% CI, 1.28 to 1.86), and intimate kissing (adjusted odds ratio, 1.65; 95% CI, 1.33 to 2.05). No vaccine safety concerns were identified. CONCLUSIONS: Among Australian adolescents, the 4CMenB vaccine had no discernible effect on the carriage of disease-causing meningococci, including group B. (Funded by GlaxoSmithKline; ClinicalTrials.gov number, NCT03089086.).
Assuntos
Portador Sadio/prevenção & controle , Infecções Meningocócicas/prevenção & controle , Vacinas Meningocócicas/imunologia , Neisseria meningitidis Sorogrupo B/isolamento & purificação , Neisseria meningitidis/isolamento & purificação , Adolescente , Austrália/epidemiologia , Portador Sadio/epidemiologia , Feminino , Humanos , Masculino , Neisseria meningitidis/genética , Razão de Chances , Prevalência , Fatores de Risco , Sorogrupo , Método Simples-CegoRESUMO
BACKGROUND: Preterm infants suffer higher morbidity and mortality rates compared to full-term infants, but little is known about how changes to oral and respiratory tract microbiota may impact disease development. METHODS: Here, very preterm neonates (n = 50) were selected to study oral and respiratory microbiota development during the first few months post-birth, where 26 individuals were diagnosed with BPD and/or sepsis. These infants were compared to 14 healthy full-term infants and 16 adults. Microbiota diversity, composition, and species abundances were calculated from 16S ribosomal RNA gene sequences in buccal swabs and tracheal aspirates at two time points (within a week and 1-3 months post-birth). RESULTS: Collection time point was the biggest factor to significantly influence the preterm oral microbial diversity and composition. In addition, BPD and sepsis were linked to distinct preterm oral microbiota diversity and composition, and opportunistic pathogens previously associated with these diseases were identified in the initial sample for both healthy preterm neonates and those with the disease. Compared to the full-term infant and adult dataset, preterm infant diversity and composition was initially significantly different, but resembled full-term infant diversity and composition over time. CONCLUSION: Overall, consequences of microbiota development need further examination in preterm infant infections and later development. IMPACT: Non-gut microbiota research on preterm infants is limited. At one week post-birth, preterm infants harbor distinct oral microbiota that are not shared with full-term children or adults, eventually becoming similar to full-term infants at 36 weeks postmenstrual age. DNA from potential opportunistic pathogens was observed in the mouth and lungs of preterm infants within a week of birth, and microbes associated with BPD were identified in the lungs. Oral microbiota in preterm infants over the first 2-3 months is unique and may be connected to short- and long-term health outcomes in these children.
RESUMO
Many trials use stratified randomisation, where participants are randomised within strata defined by one or more baseline covariates. While it is important to adjust for stratification variables in the analysis, the appropriate method of adjustment is unclear when stratification variables are affected by misclassification and hence some participants are randomised in the incorrect stratum. We conducted a simulation study to compare methods of adjusting for stratification variables affected by misclassification in the analysis of continuous outcomes when all or only some stratification errors are discovered, and when the treatment effect or treatment-by-covariate interaction effect is of interest. The data were analysed using linear regression with no adjustment, adjustment for the strata used to perform the randomisation (randomisation strata), adjustment for the strata if all errors are corrected (true strata), and adjustment for the strata after some errors are discovered and corrected (updated strata). The unadjusted model performed poorly in all settings. Adjusting for the true strata was optimal, while the relative performance of adjusting for the randomisation strata or the updated strata varied depending on the setting. As the true strata are unlikely to be known with certainty in practice, we recommend using the updated strata for adjustment and performing subgroup analyses, provided the discovery of errors is unlikely to depend on treatment group, as expected in blinded trials. Greater transparency is needed in the reporting of stratification errors and how they were addressed in the analysis.
Assuntos
Projetos de Pesquisa , Humanos , Modelos Lineares , Simulação por Computador , Distribuição AleatóriaRESUMO
INTRODUCTION: Clinical trial designs based on the assumption of independent observations are well established. Clustered clinical trial designs, where all observational units belong to a cluster and outcomes within clusters are expected to be correlated, have also received considerable attention. However, many clinical trials involve partially clustered data, where only some observational units belong to a cluster. Examples of such trials occur in neonatology, where participants include infants from both singleton and multiple births, and ophthalmology, where one or two eyes per participant may need treatment. Partial clustering can also arise in trials of group-based treatments (e.g. group education or counselling sessions) or treatments administered individually by a discrete number of health care professionals (e.g. surgeons or physical therapists), when this is compared to an unclustered control arm. Trials involving partially clustered data have received limited attention in the literature and the current lack of standardised terminology may be hampering the development and dissemination of methods for designing and analysing these trials. METHODS AND EXAMPLES: In this article, we present an overarching definition of partially clustered trials, bringing together several existing trial designs including those for group-based treatments, clustering due to facilitator effects and the re-randomisation design. We define and describe four types of partially clustered trial designs, characterised by whether the clustering occurs pre-randomisation or post-randomisation and, in the case of pre-randomisation clustering, by the method of randomisation that is used for the clustered observations (individual randomisation, cluster randomisation or balanced randomisation within clusters). Real life examples are provided to highlight the occurrence of partially clustered trials across a variety of fields. To assess how partially clustered trials are currently reported, we review published reports of partially clustered trials. DISCUSSION: Our findings demonstrate that the description of these trials is often incomplete and the terminology used to describe the trial designs is inconsistent, restricting the ability to identify these trials in the literature. By adopting the definitions and terminology presented in this article, the reporting of partially clustered trials can be substantially improved, and we present several recommendations for reporting these trial designs in practice. Greater awareness of partially clustered trials will facilitate more methodological research into their design and analysis, ultimately improving the quality of these trials.
Assuntos
Projetos de Pesquisa , Humanos , Lactente , Análise por Conglomerados , Ensaios Clínicos como AssuntoRESUMO
BACKGROUND: Literature shows that intraosseous (IO) infusions are capable of providing increased local concentrations compared to those administered via intravenous (IV) access. Successes while using the technique for antibiotic prophylaxis administration in total knee arthroplasty (TKA) prompted consideration for use in total hip arthroplasty (THA) however; no study exists for the use of IO vancomycin in THA. METHODS: This single-blinded randomized control trial was performed from December 2020 to May 2022. Twenty patients were randomized into 1 of 2 groups: IV vancomycin (15 mg/kg) given routinely, or IO vancomycin (500 mg/100cc of NS) injected into the greater trochanter during incision. Serum vancomycin levels were collected at incision and closure. Soft tissue vancomycin levels were taken from the gluteus maximus (at start and end of case), and acetabular pulvinar tissue. Bone vancomycin levels were taken from the femoral head, acetabular reamings, and intramedullary bone. Adverse local/systemic reactions, 30-day complications, and 90-day complications were also tracked. RESULTS: A statistically significant reduction in serum vancomycin levels was seen when comparing IO to IV vancomycin at both the start and at the end of the procedure. All local tissue samples had higher concentrations of vancomycin in the IO group. Statistically significant increases were present within the acetabular bone reamings, and approached significance in intramedullary femoral bone. CONCLUSION: This study demonstrates the utility of IO vancomycin in primary THA with increased local tissue and decreased systemic concentrations. With positive findings in an area without tourniquet use, IO may be considered for antibiotic delivery for alternative procedures.
Assuntos
Artroplastia de Quadril , Distinções e Prêmios , Infecções Relacionadas à Prótese , Ferida Cirúrgica , Humanos , Vancomicina , Artroplastia de Quadril/efeitos adversos , Antibacterianos/uso terapêutico , Antibioticoprofilaxia/métodos , Ferida Cirúrgica/complicações , Infecções Relacionadas à Prótese/etiologia , Infecções Relacionadas à Prótese/prevenção & controle , Infecções Relacionadas à Prótese/tratamento farmacológicoRESUMO
CONTEXT: Hispanic or Latino men who have sex with men (HLMSM) are disproportionately affected by the HIV/AIDS epidemic in New York State (NYS) and nationally. In 2019, HLMSM comprised 13% of all new diagnoses and 21% of new diagnoses among men who have sex with men (MSM) in NYS excluding New York City. HIV home testing programs are effective methods for increasing HIV testing. OBJECTIVE: This pilot sought to determine whether the NYS HIV Home Test Giveaway (HHTG) can effectively reach priority populations, specifically HLMSM/transgender/gender nonconforming persons who have sex with men, to increase uptake of HIV home testing services and identify new HIV infections. DESIGN/SETTING: We recruited participants using media campaigns linked to a brief self-administered eligibility survey. Eligible participants provided their e-mail address to receive a code for a free HIV home test and were sent a self-administered follow-up survey 4 to 11 weeks after eligibility survey completion. PARTICIPANTS: The 2018 and 2019 NYS HHTG reached 1214 and 1340 participants, respectively. A total of 606 participants in 2018 and 736 participants in 2019 were eligible to receive the HHTG home test kit. MAIN OUTCOME MEASURES: HHTG utilization and test results. RESULTS: Hispanic or Latino persons participated at higher rates (34.8% and 25.4% in 2018 and 2019, respectively) than the percentage of Hispanic men in prioritized zip codes (15.7% and 15.6% in 2018 and 2019, respectively). The majority of participants who received HHTG test kits used them to test themselves (87.5% in 2018 and 90.6% in 2019). Across both rounds, 4 participants reported new HIV-positive results, for a seropositivity rate of approximately 1%. CONCLUSION: Geospatial prioritization was successful in reaching Hispanic or Latino priority populations for HIV testing. HIV self-testing programs such as the HHTG are beneficial methods to reach priority populations for state and national Ending the HIV Epidemic initiatives.
Assuntos
Infecções por HIV , Teste de HIV , Autoteste , Minorias Sexuais e de Gênero , Humanos , Masculino , Hispânico ou Latino , Infecções por HIV/diagnóstico , Infecções por HIV/epidemiologia , Infecções por HIV/prevenção & controle , Homossexualidade Masculina , Cidade de Nova Iorque/epidemiologiaRESUMO
BACKGROUND: Recombinant protein-based vaccines targeting serogroup B meningococci protect against invasive disease but impacts on carriage are uncertain. This study assessed carriage prevalence of disease-associated meningococci in 2018-2020 as the proportion of vaccinated adolescents increased following introduction of a school-based 4CMenB immunization program. METHODS: Eligible participants who completed high school (aged 17-25) in South Australia in the previous year had an oropharyngeal swab taken and completed a risk factor questionnaire. Disease-associated meningococci (genogroups A, B, C, W, X, Y) were detected by meningococcal and genogroup-specific polymerase chain reaction. RESULTS: The analysis included 4104 participants in 2018, 2690 in 2019, and 1338 in 2020. The proportion vaccinated with 4CMenB increased from 43% in 2018, to 78% in 2019, and 76% in 2020. Carriage prevalence of disease-associated meningococci in 2018 was 225/4104 (5.5%). There was little difference between carriage prevalence in 2019 (134/2690, 5.0%; adjusted odds ratio [aOR], 0.82; 95% confidence interval [CI], .64-1.05) and 2020 (68/1338, 5.1%; aOR, 0.82; 95% CI, .57-1.17) compared to 2018. CONCLUSIONS: Increased 4CMenB uptake in adolescents was not associated with decline in carriage of disease-associated meningococci. 4CMenB immunization programs should focus on direct (individual) protection for groups at greatest risk of disease. CLINICAL TRIALS REGISTRATION: NCT03419533.
Assuntos
Infecções Meningocócicas , Vacinas Meningocócicas , Neisseria meningitidis Sorogrupo B , Neisseria meningitidis , Adolescente , Estudos Transversais , Humanos , Infecções Meningocócicas/epidemiologia , Infecções Meningocócicas/prevenção & controleRESUMO
BACKGROUND: Hip abductor complex tears remain an injury without a clear consensus on management. Surgical treatment has been recommended after unsuccessful nonoperative management. This study evaluates both tenodesis and bone trough techniques, with treatment choices guided by previously described tear classification. METHODS: This is a retrospective cohort study of 45 hips in 44 patients who underwent surgical treatment for symptomatic, chronic hip abductor tear unresponsive to nonoperative treatment. Demographics and preoperative and postoperative values (including visual analog scale pain scores, gait assessment, and muscle strength) were evaluated. Type I tears were treated using tendon tenodesis. Type II tears were treated through a bone trough repair. RESULTS: Forty-five hips (44 patients) were operated on with a minimum of 6-month follow-up. There were 27 type I and 18 type II tears. Eighty-seven percent of patients were female. Twenty-eight percent of type II patients (5/18) had a preexisting arthroplasty in place. Significant improvements in pain (P < .001), gait (P < .001), and muscle strength (P < .001) were achieved in both the tear types. Type I repairs showed superior results to type II repairs. However, both showed significant improvements. Postoperative magnetic resonance imaging at 6 months showed healed tenodesis in 81% (17/21) of type I tears and 50% (5/10) of type II tears. CONCLUSION: Our study shows improvement in pain and function after surgical repair of hip abductor tendon injuries in both simple and complex tears. This improvement is seen even during ongoing surgical site healing. Magnetic resonance imaging findings may remain abnormal for more than 1 year after surgery and do not clearly denote repair failure.
Assuntos
Lesões do Quadril , Tenodese , Artrodese , Nádegas/cirurgia , Feminino , Lesões do Quadril/cirurgia , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Músculo Esquelético/cirurgia , Dor/cirurgia , Estudos Retrospectivos , Ruptura/cirurgiaRESUMO
BACKGROUND: Intraosseous (IO) infusion of medication is a novel technique for total knee arthroplasty (TKA) antibiotic prophylaxis. To decrease postoperative pain in TKA patients, we investigated addition of morphine to a standard IO antibiotic injection. METHODS: A double-blind, randomized controlled trial was performed on 48 (24 each) consecutive patients undergoing primary TKA. The control group received an IO injection of antibiotics as per the standard protocol. The experimental group received an IO antibiotic injection with 10 mg of morphine. Pain, nausea, and opioid use were assessed up to 14 days postoperatively. Morphine and interleukin-6 serum levels were obtained 10 hours postoperatively in a subgroup of 20 patients. RESULTS: The experimental group had lower Visual Analog Scale pain score at 1, 2, 3, and 5 hours postoperatively (P = .0032, P = .005, P = .020, P = .010). This trend continued for postoperative day 1, 2, 8, and 9 (40% reduction, P = .001; 49% reduction, P = .036; 38% reduction, P = .025; 33% reduction, P = .041). The experimental group had lower opioid consumption than the control group for the first 48 hours and second week postsurgery (P < .05). Knee Injury and Osteoarthritis Outcome Score for Joint Replacement scores for the experimental group showed significant improvement at 2 and 8 weeks postsurgery (P < .05). Serum morphine levels in the experimental group were significantly less than the control group 10 hours after IO injection (P = .049). CONCLUSION: IO morphine combined with a standard antibiotic solution demonstrates superior postoperative pain relief immediately and up to 2 weeks. IO morphine is a safe and effective method to lessen postoperative pain in TKA patients. LEVEL OF EVIDENCE: Therapeutic, Level 1.
Assuntos
Artroplastia do Joelho , Morfina , Analgésicos Opioides/uso terapêutico , Antibacterianos/uso terapêutico , Artroplastia do Joelho/efeitos adversos , Método Duplo-Cego , Humanos , Morfina/uso terapêutico , Dor Pós-Operatória/tratamento farmacológico , Dor Pós-Operatória/prevenção & controleRESUMO
BACKGROUND: From 2017, a statewide cluster randomized trial was conducted in South Australia to assess the impact of the meningococcal B vaccine 4CMenB on pharyngeal Neisseria meningitidis carriage in adolescents. Senior schools were randomized to receive the vaccine in 2017 (intervention) or 2018 (control). In this study we report the vaccine impact of 4CMenB on serogroup B invasive meningococcal disease (IMD) in 16- to 19-year-old adolescents in South Australia. METHODS: This observational time series analysis of serogroup B IMD cases compares the 14 years prior to the commencement of the trial (2003-2016) with the 2 years following 4CMenB vaccination of the 2017 adolescent cohort. RESULTS: Approximately 62% of year 10 and 11 students (15-16 years old) in South Australia enrolled in the trial. A total of 30â 522 year 10-12 students received at least 1 dose of 4CMenB. The number of serogroup B IMD cases in 16- to 19-year old adolescents in South Australia increased on average by 10% per year from 2003 to 2016 (95% confidence interval [CI], 6%-15%, Pâ <â .001), peaking with 10 cases in 2015. Serogroup B IMD cases reduced to 5 in 2017-2018 and 1 in 2018-2019, below the expected numbers of 9.9 (95% prediction interval [PI], 3.9-17.5) and 10.9 (95% PI, 4.4-19.1), respectively. This translated to an overall reduction in the number of serogroup B IMD cases of 71% (95% CI, 15%-90%, Pâ =â .02). There were no serogroup B IMD cases in vaccinated adolescents. CONCLUSIONS: Vaccinating adolescents with 4CMenB was associated with a reduction in group B meningococcal disease in South Australia. CLINICAL TRIALS REGISTRATION: NCT03089086.