RESUMO
OBJECTIVE: Erionite is a naturally occurring fibrous mineral found in soils in some geographical regions. Known for its potency for causing mesothelioma in the Cappadocia region of Turkey, the erionite fiber has attracted interest in the United States due to its presence in a band of rock that extends from Mexico to Montana. There are few toxicology studies of erionite, but all show it to have unusually high chronic toxicity. Despite its high potency compared to asbestos fibers, erionite has no occupational or environmental exposure limits. This paper takes what has been learned about the chemical and physical characteristics of the various forms of asbestos (chrysotile, amosite, anthophyllite, and crocidolite) and predicts the potency of North American erionite fibers. MATERIALS AND METHODS: Based on the fiber potency model in Korchevskiy et al. (2019) and the available published information on erionite, the estimated mesothelioma potency factors (the proportion of mesothelioma mortality per unit cumulative exposure (f/cc-year)) for erionites in the western United States were determined. RESULTS AND DISCUSSION: The model predicted potency factors ranged from 0.19 to 11.25 (average â¼3.5), depending on the region. For reference, crocidolite (the most potent commercial form of asbestos) is assigned a potency factor â¼0.5. CONCLUSION: The model predicted mesothelioma potency of Turkish erionite (4.53) falls in this same range of potencies as erionite found in North America. Although it can vary by region, a reasonable ratio of average mesothelioma potency based on this model is 3,000:500:100:1 comparing North American erionite, crocidolite, amosite, and chrysotile (from most potent to least potent).
Assuntos
Amianto , Neoplasias Pulmonares , Mesotelioma Maligno , Mesotelioma , Zeolitas , Humanos , Asbesto Crocidolita/toxicidade , Asbestos Serpentinas/toxicidade , Amianto Amosita/toxicidade , Mesotelioma/induzido quimicamente , Mesotelioma/epidemiologia , Mesotelioma Maligno/complicações , Amianto/toxicidade , Montana , Neoplasias Pulmonares/epidemiologiaRESUMO
We explore explicit electron pair behaviour within the chemical bond (and lone pairs) by calculating the probability distribution for the center-of-mass (extracule) of an electron pair described by single localized orbitals. Using Edmiston-Ruedenberg localized orbitals in a series of 61 chemical systems, we demonstrate the utility of the extracule density as an interpretive tool in chemistry. By accessing localized regions of chemical space we simplify the interpretation of the extracule density and afford a quantum mechanical interpretation of "chemically intuitive" features of electronic structure. Specifically, we describe the localized effects on chemical bonds due to changes in electronegativities of bonded neighbours, bond strain, and non-covalent interactions. We show that the extracule density offers unique insight into electronic structure and allows one to readily quantify the effects of changing the chemical environment.
RESUMO
We present an application of the recently introduced Localized Pair Model (LPM) [Z. A. Zielinksi and J. K. Pearson, Comput. Theor. Chem., 2013, 1003, 7990] to characterize and quantify properties of the chemical bond in a series of substituted benzoic acid molecules. By computing interelectronic distribution functions for doubly-occupied Edmiston-Ruedenberg localized molecular orbitals (LMOs), we show that chemically intuitive electron pairs may be uniquely classified and bond strength may be predicted with remarkable accuracy. Specifically, the HF/u6-311G(d,p) level (where u denotes a complete uncontraction of the basis set) is used to generate the relevant LMOs and their respective interelectronic distribution functions can be linearly correlated to the well-known Hammett σp or σm parameters with near-unity correlation coefficients.
RESUMO
The sudden death of three calves, one diarrheic calf, and one aborted fetus from four farms in southern Brazil was investigated. Two Histophilus somni-associated syndromes were identified: systemic histophilosis (n = 4) and abortion (n = 1). The principal pathological findings included vasculitis, meningoencephalitis with thrombosis, necrotizing myocarditis, renal infarctions, hepatic abscesses, and bronchopneumonia. PCR assays were used to amplify specific amplicons of the ovine herpesvirus 2, bovine herpesvirus 1 and -5, Listeria monocytogenes, H. somni, and pestivirus; bovine group A rotavirus (BoRV-A) and bovine coronavirus (BCoV) were investigated in calves with diarrhea. H. somni DNA was amplified in tissues from all calves and the brain of the aborted fetus with pathological alterations consistent with histophilosis. All other PCR assays were negative; BoRV-A and BCoV were not identified. These findings confirm the participation of H. somni in the pathological alterations observed in this study and represent the first description of histophilosis in cattle from Brazil.
Assuntos
Aborto Animal/patologia , Doenças dos Bovinos/patologia , Infecções por Haemophilus/veterinária , Haemophilus somnus/genética , Meningite por Haemophilus/veterinária , Aborto Animal/microbiologia , Animais , Brasil , Bovinos , Doenças dos Bovinos/microbiologia , Infecções por Haemophilus/complicações , Infecções por Haemophilus/microbiologia , Infecções por Haemophilus/patologia , Haemophilus somnus/isolamento & purificação , Haemophilus somnus/metabolismo , Meningite por Haemophilus/microbiologia , Meningite por Haemophilus/patologia , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase/veterinária , RNA Bacteriano/genética , RNA Bacteriano/metabolismo , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/metabolismo , Alinhamento de Sequência/veterinária , Análise de Sequência de DNA/veterináriaRESUMO
To demonstrate thrombolytic efficacy of a tissue plasminogen activator (tPA)-loaded echogenic liposome (TELIP) formulation in a rabbit thrombotic stroke model (the most relevant animal model for evaluation of directed thrombolytic therapy for ischemic stroke), we sought to develop a means of monitoring thrombus dissolution quantitatively by ultrasound imaging methods. We hypothesized that a gas-free ultrasound contrast agent can be incorporated into blood clots at a concentration that does not affect the tPA-mediated clot dissolution rate, while enabling quantitative assessment of the clot dissolution rate. Clots were formed from a mixture of whole rabbit blood, 1 M calcium chloride, human thrombin and varying amounts of microcrystalline cellulose. Washed clots in tubes were weighed at 30, 60 and 90 minutes after addition of recombinant tPA (rtPA) in porcine plasma (100 µg/ml). Clot echogenicity at each time point was assessed using a Philips HDI 5000 ultrasound system using an L12-5 linear array probe. Recorded Images underwent videodensitometric analysis that converted image reflectivity to mean gray scale values (MGSV). We found that 1.12 mg/ml of microcrystalline cellulose in rabbit blood clots (0.2 ml) provided optimal echogenicity without affecting clot dissolution rates (0.3-0.6 mg/min.) caused by rtPA. The clot dissolution rate measured by videodensitometric analysis of the echogenic clots agreed well with that determined by mass loss measurements (0.28% 0-time value/minute). This method will be important for demonstrating in vivo efficacy with potentially decreased hemorrhagic effects provided by directed tPA vehicles relative to systemic administration of the free thrombolytic.
RESUMO
Bovine respiratory disease (BRD) is considered a major cause of morbidity and mortality in young calves and is caused by a range of infectious agents, including viruses and bacteria. This study aimed to determine the frequency of viral and bacterial pathogens detected in calves with BRD from high-production dairy cattle herds and to perform the molecular characterization of N and S1 genes in identified bovine coronavirus (BCoV) strains. Nasal swabs were collected from 166 heifer calves, namely, 85 symptomatic and 81 asymptomatic calves aged between 5 and 90 days, from 10 dairy cattle herds. Nasal swabs were evaluated using molecular techniques for the identification of viruses (BCoV, bovine alphaherpesvirus 1, bovine viral diarrhea virus, bovine parainfluenza virus 3, and bovine respiratory syncytial virus) and bacteria (Pasteurella multocida, Mannheimia haemolytica, Histophilus somni, and Mycoplasma bovis). In addition, five and two BCoV-positive samples were submitted to N and S1 gene amplification and nucleotide sequencing, respectively. The frequency of diagnosis of BCoV was higher (56%, 93/166) than the frequency of P. multocida (39.8%, 66/166) and M. haemolytica (33.1%, 55/166). The three microorganisms were identified in the calves of symptomatic and asymptomatic heifer calve groups. All other pathogens included in the analyses were negative. In the phylogenetic analysis of the S1 gene, the Brazilian strains formed a new branch, suggesting a new genotype, called # 15; from the N gene, the strains identified here belonged to cluster II. This study describes high rates of BCoV, P. multocida, and M. haemolytica in heifer calves from high-production dairy cattle herds with BRD. Additionally, the molecular characterization provides evidence that the circulating BCoV strains are ancestrally different from the prototype vaccine strains and even different BCoV strains previously described in Brazil.
RESUMO
An insertional mutagenesis system that uses transposons carrying unique DNA sequence tags was developed for the isolation of bacterial virulence genes. The tags from a mixed population of bacterial mutants representing the inoculum and bacteria recovered from infected hosts were detected by amplification, radiolabeling, and hybridization analysis. When applied to a murine model of typhoid fever caused by Salmonella typhimurium, mutants with attenuated virulence were revealed by use of tags that were present in the inoculum but not in bacteria recovered from infected mice. This approach resulted in the identification of new virulence genes, some of which are related to, but functionally distinct from, the inv/spa family of S. typhimurium.
Assuntos
Elementos de DNA Transponíveis , Genes Bacterianos , Mutagênese Insercional , Salmonelose Animal/microbiologia , Salmonella typhimurium/patogenicidade , Animais , Sequência de Bases , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Reação em Cadeia da Polimerase , Salmonella typhimurium/genética , Sitios de Sequências Rotuladas , Virulência/genéticaRESUMO
The purpose of this study was to develop and validate a self-report measure of body image and sexual adjustment in breast cancer patients: the Sexual Adjustment and Body Image Scale (SABIS). Three hundred and fifty three women diagnosed with primary breast cancer that had completed initial surgical treatment completed the SABIS and five measures of psychological, psychosocial, and sexual functioning. Psychometric properties of the SABIS were examined and it was found to be a reliable and valid means of assessing body image and sexuality in breast cancer patients following surgery.
Assuntos
Imagem Corporal , Neoplasias da Mama/psicologia , Qualidade de Vida/psicologia , Autoimagem , Disfunções Sexuais Psicogênicas/psicologia , Inquéritos e Questionários , Adulto , Atitude Frente a Saúde , Neoplasias da Mama/cirurgia , Feminino , Nível de Saúde , Humanos , Mastectomia/psicologia , Pessoa de Meia-Idade , Psicometria , Reprodutibilidade dos Testes , Disfunções Sexuais Psicogênicas/diagnóstico , Saúde da MulherRESUMO
The systemic-constructivist approach to studying and benefiting couples was derived from qualitative and quantitative research on distressed couples over the past 10 years. Systemic-constructivist couple therapy (SCCT) is the clinical intervention that accompanies the approach. SCCT guides the therapist to work with both the intrapersonal and the interpersonal aspects of marriage while also integrating the social-environmental context of the couple. The theory that underlies SCCT is explained, including concepts such as we-ness and interpersonal processing. The primary components of the therapy are described. Findings described previously in an inaugural monograph containing extensive research demonstrating the long-term utility of SCCT are reviewed. (PsycINFO Database Record (c) 2010 APA, all rights reserved).
RESUMO
Changes in partners' sense of self-in-relationship, which a systemic-constructivist couple therapy (SCCT) induced, led to robust improvement in satisfaction in 2 studies and a follow-up study. In each study, 13 referred couples completed measures of satisfaction, mutuality, similarities, and other-in-self construal pre-post 12 hours of SCCT. The authors reliably coded transcripts of 1st and final sessions for each partner's we-ness, the identity that each partner establishes in relationship to the other. Having met the criteria for the rigorous study of change in single group process-outcome design, changes in we-ness accompanied large posttherapy dyadic increments on all variables in each study. Therapeutic gains appeared at follow-up and correlated with increased we-ness obtained at end of therapy 2 years earlier. The authors raise theoretical implications for all types of couple therapies and explain clinical techniques.
Assuntos
Terapia de Casal , Relações Interpessoais , Casamento/psicologia , Satisfação Pessoal , Cônjuges/psicologia , Adulto , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Psicologia Clínica , AutoimagemRESUMO
The published literature on depression in multiple sclerosis (MS) is reviewed quantitatively. The authors report mean effect sizes for 20 studies comparing depression scores of MS patients with those of healthy participants (d=1.07) and 21 studies comparing depression scores of MS patients with those of patients who have other chronic conditions (d=-0.14). The confidence interval for the mean overall MS-medical comparison included 0. However, subgroups of patients with chronic fatigue and spinal-neuromuscular conditions were more and less depressed than MS patients, respectively. Results indicate that a majority of MS patients with mild to moderate disability levels are distinguishable from healthy people in terms of depressive symptoms. However, the depression-disease link is complex and not specific to this form of demyelinating illness.
Assuntos
Depressão/etiologia , Depressão/psicologia , Esclerose Múltipla/complicações , Esclerose Múltipla/psicologia , Doença Crônica/psicologia , Intervalos de Confiança , Avaliação da Deficiência , Humanos , MEDLINE , Metanálise como Assunto , Inventário de Personalidade/estatística & dados numéricos , Escalas de Graduação Psiquiátrica/estatística & dados numéricos , Viés de Publicação/estatística & dados numéricos , Índice de Gravidade de DoençaRESUMO
In a prospective study, we evaluated familial aggregation of blood pressure in a sample of 175 normotensive families with children 3 to 6 yr old. Systolic and diastolic blood pressure measurements of parents and children were correlated at 1, 2, and 3 yr intervals. Spearman rank-order correlation coefficients between parents and children were significant for mother-son pairs. In particular, mother-son blood pressure correlation coefficients were significant for systolic blood pressure across all 3 yr and for diastolic blood pressure during yr 2. Further analyses were performed adjusting for body mass index (BMI), age, physical activity, sodium intake, potassium intake, and parental smoking status, and alcohol use. The Spearman correlation coefficients for mother-son pairs remained significant for yr 1 and 3 after adjusting for these blood pressure correlates. These results are consistent with cross-sectional studies and suggest that both genetic and environmental contributions to blood pressure status are important in young children.
Assuntos
Pressão Sanguínea/genética , Pais , Adulto , Fatores Etários , Consumo de Bebidas Alcoólicas , Determinação da Pressão Arterial , Índice de Massa Corporal , Pré-Escolar , Ingestão de Alimentos , Feminino , Variação Genética , Humanos , Masculino , Atividade Motora , Estudos Prospectivos , Análise de Regressão , Fatores Sexuais , Fumar , Inquéritos e QuestionáriosRESUMO
The decrease of glutamic acid decarboxylase (GAD) has been reported as an important neurochemical alteration of the inhibitory GABAergic interneurons in schizophrenia. To our knowledge no studies have investigated the genetic variants influencing GAD expression. To search for markers contributing to the genetic susceptibility of schizophrenia, we typed two polymorphisms by polymerase chain reaction-restriction fragment length polymorphism in both GAD1 and GAD2 genes in 112 triad families and 46 case-controls. We used the Transmission Disequilibrium Test to perform the qualitative family-based analyses and found negative results (GAD1, chi2 = 0.273, 1 degree of freedom, P = 0.60; GAD2, chi2 = 0, 1 degree of freedom, P = 1). In addition there were no associations with GAD1 and GAD2 and quantitative measures of suicide behaviour in this sample. Although our results are negative, this was the first study to investigate GAD genes in schizophrenia, and further studies of these genes, particularly with schizophrenia subtypes, may prove valuable.
Assuntos
Glutamato Descarboxilase/genética , Isoenzimas/genética , Polimorfismo Genético , Esquizofrenia/genética , Idade de Início , Alelos , Substituição de Aminoácidos , Estudos de Casos e Controles , Desoxirribonucleases de Sítio Específico do Tipo II , Feminino , Predisposição Genética para Doença , Hospitalização/estatística & dados numéricos , Humanos , Masculino , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Esquizofrenia/classificação , Esquizofrenia/epidemiologia , SuicídioRESUMO
HYPOTHESIS: Tactile imaging can accurately document the palpable extent of breast masses. DESIGN: Prospective nonrandomized interventional trial, comparing mass size estimates from preoperative physical examination, ultrasound, and tactile imaging with postoperative measurements of the resected masses. SETTING: A community ambulatory surgical center and a university hospital tertiary care center. PATIENTS: Twenty-three women undergoing surgical excision of breast masses. All subjects had a single, palpable, dominant mass, 0.5 to 3 cm in diameter. INTERVENTION: Prior to surgery, the size of each mass was estimated from tactile imaging using an array of pressure sensors that is stroked over the mass. Size was also estimated by ultrasound and physical examination. Immediately following resection of the mass, it was bisected, and the palpable extent was measured with a caliper. MAIN OUTCOME MEASURE: Maximum mass diameter estimates from ultrasound, physical examination, and tactile imaging, compared with the resected measurement. RESULTS: Tactile imaging estimates were repeatable (7.5% mean SD for multiple estimates of the same mass) and show good agreement with the resected measurements. Mean absolute error was 13%, and linear regression with zero intercept had a slope of 0.94, r(2) = 0.51. Physical examination and ultrasound estimates had respective mean absolute errors of 46% and 34%, regression slopes of 1.27 and 0.89, and r(2) = 0.28 and 0.37. CONCLUSIONS: Tactile imaging can provide accurate and reproducible estimates of the size of breast masses. This capability can enhance cancer surveillance for patients with benign masses (eg, due to scarring or fibrocystic changes) because previous work suggests that reliable detection of a difference in mass size by physical examination requires a 40% change in diameter. In contrast, this study suggests tactile imaging requires only a 15% change (95% confidence interval).
Assuntos
Neoplasias da Mama/diagnóstico , Diagnóstico por Imagem/métodos , Diagnóstico por Imagem/instrumentação , Feminino , Humanos , Modelos Lineares , Pessoa de Meia-Idade , Palpação , Estudos Prospectivos , Ultrassonografia MamáriaRESUMO
The epidemiology of infections in the puerperium (post partum period) is not well understood and remains underestimated because surveillance systems are often limited to the acute care setting. The most common source of persistent fever after delivery is genital tract infection for which diagnosis remains mostly clinical and antibiotic treatment empiric. This review will emphasize surgical site infections (SSIs) and endometritis. Septic thrombo-phlebitis, mastitis, urinary tract infections and rare infections will be covered in less detail. Puerperal sepsis will not be reviewed.
RESUMO
BACKGROUND: The Acute Respiratory Distress Syndome (ARDS) Network low tidal volume (VT) trial paved the ground for mechanically ventilating ARDS patients with a VT of 6 mL/kg ideal body weight (IBW). Although there is no consensus that a low VT is advantageous in non-ARDS patients,it is accepted that high VT should be avoided. Because compliance rates with ventilator recommendations are 30%, there is a need for process improvement. We postulated that a computerized screen prompt that recommended VT based on height would improve compliance with low VT.During ventilator order entry, the computerized decision tool prompts the clinician and encourages ventilation of patients at 8 mL/kg IBW, and 6 mL/kg IBW for patients with ARDS. METHODS: A retrospective review was performed on patients who required volume controlled mechanical ventilation over a 3-y period. Subjects were chosen randomly from the respiratory records of 6 different ICUs at a single tertiary care academic center. Half of the charts selected were before intervention of on-screen prompt, and the other half were after implementation of the computerized decision tool. RESULTS: The initial set VT ranged from 6.26 to 13.45 mL/kg IBW, with a mean of 8.92 mL/kg. After implementation of the on-screen prompt, mean VT decreased by 0.84 mL/kg to 8.07 mL/kg (P= .001) with a lower range of 4.73-11.56 mL/kg IBW. We also noted a significant decrease in the number of subjects placed on an initial VT > 10 mL/kg IBW from 20% to 4% (P= .003). CONCLUSIONS: A computerized clinical decision tool with the preferred initial VT settings based on the patients' sex and height is a safe and reliable way to increase low VT strategy compliance across multiple ICUs. Its limitations are similar to those shared by other computer-generated prompts.
Assuntos
Técnicas de Apoio para a Decisão , Respiração Artificial/métodos , Síndrome do Desconforto Respiratório/terapia , Interface Usuário-Computador , Adulto , Idoso , Estatura , Peso Corporal , Cuidados Críticos , Feminino , Fidelidade a Diretrizes , Humanos , Masculino , Pessoa de Meia-Idade , Respiração Artificial/instrumentação , Estudos Retrospectivos , Fatores Sexuais , Volume de Ventilação Pulmonar , Ventiladores MecânicosRESUMO
OBJECTIVE: To determine the proportion of patients with rheumatoid arthritis (RA) under rheumatologic care treated with disease-modifying antirheumatic drugs (DMARD) within 6 months from symptom onset and the components of time to treatment and its predictors. METHODS: A historical inception cohort of 339 patients with RA randomly selected from 18 rheumatology practices was audited. The proportion that initiated DMARD treatment within 6 months from symptom onset was estimated using Kaplan-Meier analysis. Time to each component of the care pathway was estimated. Multivariable modeling was used to determine predictors of early treatment using 12 preselected variables available in the clinical charts. Bootstrapping was used to validate the model. RESULTS: Within 6 months from symptom onset, 41% (95% CI 36%-46%) of patients were treated with DMARD. The median time to treatment was 8.4 (interquartile range 3.8-24) months. Events preceding rheumatology referral accounted for 78.1% of the time to treatment. The most prominent predictor of increased time to treatment was a concomitant musculoskeletal condition, such as osteoarthritis or fibromyalgia. The significance of other variables was less consistent across the models investigated. Included variables accounted for 0.69 ± 0.03 of the variability in the model. CONCLUSION: Fewer than 50% of patients with RA are treated with DMARD within 6 months from symptom onset. Time to referral to rheumatology represents the greatest component delay to treatment. Concomitant musculoskeletal condition was the most prominent predictor of delayed initiation of DMARD. Implications of these and other findings warrant further investigation.
Assuntos
Antirreumáticos/uso terapêutico , Artrite Reumatoide/tratamento farmacológico , Gerenciamento Clínico , Adulto , Artrite Reumatoide/epidemiologia , Canadá , Estudos de Coortes , Comorbidade , Feminino , Fibromialgia/epidemiologia , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Osteoartrite/epidemiologia , Estudos Retrospectivos , Fatores de TempoRESUMO
OBJECTIVE: To describe early rheumatologic management for newly diagnosed rheumatoid arthritis (RA) in Canada. METHODS: A retrospective cohort of 339 randomly selected patients with RA diagnosed from 2001-2003 from 18 rheumatology practices was audited between 2005-2007. RESULTS: The most frequent initial disease-modifying antirheumatic drugs (DMARD) included hydroxychloroquine (55.5%) and methotrexate (40.1%). Initial therapy with multiple DMARD (15.6%) or single DMARD and corticosteroid combinations (30.7%) was infrequent. Formal assessment measures were noted infrequently, including the Health Assessment Questionnaire (34.6%) and Disease Activity Score for 28 joints (8.9%). CONCLUSION: Initial pharmacotherapy is consistent with guidelines from the period. The infrequent reporting of multiple DMARD combinations and formal assessment measures has implications for current clinical management and warrants contemporary reassessment.