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1.
Public Health ; 193: 48-56, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33735693

RESUMO

OBJECTIVES: The COVID-19 pandemic in Wales and the UK has highlighted significant and historic inequalities in health between social groups. To better understand the composition of these inequalities and inform planning after the pandemic, we undertook a decomposition of life expectancy inequalities between the most and least deprived quintiles for men and women by age and cause of death and explored trends between 2002 and 2018. STUDY DESIGN: Statistical decomposition of life expectancy inequalities by age and cause of death using routine population mortality datasets. METHODS: We used routine statistics from the Office for National Statistics for the period 2002-2018 on population and deaths in Wales stratified by age, gender, Welsh Index of Multiple Deprivation (WIMD) 2019 quintile and cause of death, categorised by International Classification of Disease, version 10, code into 15 categories of public health relevance. We aggregated data to 3-year rolling figures to account for low numbers of events in some groups annually. Next, we estimated life expectancy at birth by quintile, gender and period using life table methods. Lastly, we performed a decomposition analysis using the Arriaga method to identify the specific disease categories and ages at which excess deaths occur in more disadvantaged areas to highlight potential areas for action. RESULTS: Life expectancy inequalities between the most and least WIMD quintiles rose for both genders between 2002 and 2018: from 4.69 to 6.02 years for women (an increase of 1.33 years) and from 6.34 to 7.42 years for men (an increase of 1.08 years). Exploratory analysis of these trends suggested that the following were most influential for women: respiratory disease (1.50 years), cancers (1.36 years), circulatory disease (1.35 years) and digestive disease (0.51 years). For men, the gap was driven by circulatory disease (2.01 years), cancers (1.39 years), respiratory disease (1.25 years), digestive disease (0.79 years), drug- and alcohol-related conditions (0.54 years) and external causes (0.54 years). Contributions for women from respiratory disease, cancers, dementia and drug- and alcohol-related conditions appeared to be increasing, while among men, there were rising contributions from respiratory, digestive and circulatory disease. CONCLUSIONS: Life expectancy inequalities in Wales remain wide and have been increasing, particularly among women, with indications of worsening trends since 2010 following the introduction of fiscal austerity. As agencies recover from the pandemic, these findings should be considered alongside any resumption of services in Wales or future health and public policy.


Assuntos
Disparidades nos Níveis de Saúde , Expectativa de Vida/tendências , Adolescente , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , COVID-19 , Causas de Morte/tendências , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Fatores Socioeconômicos , País de Gales/epidemiologia , Adulto Jovem
2.
Epidemiol Infect ; 140(9): 1714-20, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22115422

RESUMO

The objective of this research was to assess current patterns of hospital antibiotic prescribing in Northern Ireland and to determine targets for improving the quality of antibiotic prescribing. A point prevalence survey was conducted in four acute teaching hospitals. The most commonly used antibiotics were combinations of penicillins including ß-lactamase inhibitors (33·6%), metronidazole (9·1%), and macrolides (8·1%). The indication for treatment was recorded in 84·3% of the prescribing episodes. A small fraction (3·9%) of the surgical prophylactic antibiotic prescriptions was for >24 h. The results showed that overall 52·4% of the prescribed antibiotics were in compliance with the hospital antibiotic guidelines. The findings identified the following indicators as targets for quality improvement: indication recorded in patient notes, the duration of surgical prophylaxis and compliance with hospital antibiotic guidelines. The results strongly suggest that antibiotic use could be improved by taking steps to address the identified targets for quality improvement.


Assuntos
Antibacterianos/administração & dosagem , Prescrições de Medicamentos , Revisão de Uso de Medicamentos , Idoso , Idoso de 80 Anos ou mais , Prescrições de Medicamentos/normas , Prescrições de Medicamentos/estatística & dados numéricos , Feminino , Fidelidade a Diretrizes/estatística & dados numéricos , Pesquisas sobre Atenção à Saúde , Hospitais de Ensino , Humanos , Masculino , Pessoa de Meia-Idade , Irlanda do Norte
3.
Ann R Coll Surg Engl ; 104(1): e4-e5, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34730434

RESUMO

Biliary obstruction from metastatic deposits in the pancreas is rare. We present a case of primary testicular lymphoma (PTL) with pancreatic metastasis. A 56-year-old man presented to the general surgical department with signs and symptoms of obstructive jaundice. A computed tomography scan revealed multiple pancreatic metastases and a right primary testicular malignancy. Histology and positron emission tomography scanning subsequently confirmed PTL with pancreatic metastases. Metastasis to the pancreas from primary testicular malignancy is extremely rare. There is variation in prognosis between primary and secondary pancreatic malignancies and therefore in atypical cases of malignant biliary obstruction consideration must be given to the rarer secondary malignancies.


Assuntos
Icterícia Obstrutiva/etiologia , Linfoma não Hodgkin/diagnóstico por imagem , Neoplasias Pancreáticas/complicações , Neoplasias Pancreáticas/secundário , Neoplasias Testiculares/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios X
4.
J Neonatal Perinatal Med ; 15(4): 845-849, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35988227

RESUMO

We report the case of a 35-week gestation infant girl born by emergent cesarean section for fetal distress in a woman with recent coronavirus disease 2019 (COVID-19). Tests for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using polymerase chain reaction (PCR) on the infant at 24 and 48 hours of life were negative. However, at 72 hours of life, the infant's respiratory status worsened, and a repeat SARS-CoV-2 PCR was positive. The infant developed leukopenia, thrombocytopenia, and progressive respiratory failure, and died on the ninth day of life. Pathologic examination of the placenta revealed findings consistent with COVID-19 placentitis, and SARS-CoV-2 RNA staining was positive, suggesting intrauterine transmission of the infection.


Assuntos
COVID-19 , Complicações Infecciosas na Gravidez , Recém-Nascido , Lactente , Gravidez , Humanos , Feminino , SARS-CoV-2 , Cesárea , RNA Viral , Complicações Infecciosas na Gravidez/diagnóstico , Transmissão Vertical de Doenças Infecciosas , Placenta
5.
J Am Coll Cardiol ; 17(2): 355-62, 1991 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-1991891

RESUMO

To assess the extent of jeopardized myocardium in patients with single vessel coronary artery disease of variable severity and location, quantitative exercise thallium-201 single photon emission computed tomography was performed in 158 consecutive patients with angiographically proved single vessel coronary artery disease. The extent of abnormal left ventricular perfusion was quantified from computer-generated polar maps of three-dimensional myocardial radioactivity. Patients with only a moderate (51% to 69%) stenosis tended to have a small perfusion defect irrespective of the coronary artery involved. Whereas a perfusion defect measuring greater than or equal to 10% of the left ventricle was found in 78% of patients with no prior infarction and severe (greater than or equal to 70%) stenosis, this was observed in only 24% of patients with moderate stenosis. Perfusion defect size increased with increasing severity of stenosis for the entire group without infarction and for those with left anterior descending, right and circumflex coronary artery stenosis. However, the correlation between stenosis severity and perfusion defect size was at best only modest (r = 0.38, p = 0.0001). The left anterior descending artery was shown to be the most important of the three coronary arteries for providing left ventricular perfusion. Proximal stenosis of this artery produced a perfusion defect approximately twice as large as that found in patients with a proximal right or circumflex artery stenosis. However, marked heterogeneity in perfusion defect size existed among all three vessels despite comparable stenosis severity. This was most apparent for the left anterior descending coronary artery, where mid vessel stenosis commonly produced a perfusion defect similar in size to that found in proximally stenosed vessels.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Doença das Coronárias/diagnóstico por imagem , Coração/diagnóstico por imagem , Radioisótopos de Tálio , Tomografia Computadorizada de Emissão de Fóton Único , Doença das Coronárias/patologia , Vasos Coronários/patologia , Teste de Esforço , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Miocárdio/patologia
6.
J Am Coll Cardiol ; 18(3): 736-45, 1991 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1869737

RESUMO

The diagnostic value of maximal pharmacologic coronary vasodilation with intravenously administered adenosine in conjunction with thallium-201 single-photon emission computed tomography (SPECT) for detection of coronary artery disease was investigated in 101 consecutive patients who had concomitant coronary arteriography. Tomographic images were assessed visually and from computer-quantified polar maps of the thallium-201 distribution. Significant coronary artery disease, defined as greater than 50% luminal diameter stenosis, was present in 70 patients. The sensitivity for detecting patients with coronary artery disease using quantitative analysis was 87% in the total group, 82% in patients without myocardial infarction and 96% in those with prior myocardial infarction; the specificity was 90%. The sensitivity for diagnosing coronary artery disease in patients without infarction with single-, double-and triple-vessel disease was 76%, 86% and 90%, respectively. All individual stenoses were identified in 68% of patients with double-vessel disease and in 65% of those with triple-vessel disease. The extent of the perfusion defects, as quantified by polar maps, was directly related to the extent of coronary artery disease. In conclusion, quantitative thallium-201 SPECT during adenosine infusion has high sensitivity and specificity for diagnosing the presence of coronary artery disease, localizing the anatomic site of coronary stenosis and identifying the majority of affected vascular regions in patients with multivessel involvement.


Assuntos
Adenosina , Doença das Coronárias/diagnóstico por imagem , Vasos Coronários/efeitos dos fármacos , Coração/diagnóstico por imagem , Tomografia Computadorizada de Emissão de Fóton Único , Circulação Coronária/efeitos dos fármacos , Dipiridamol , Estudos de Avaliação como Assunto , Teste de Esforço , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Radioisótopos de Tálio
7.
J Am Coll Cardiol ; 20(2): 265-75, 1992 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1634661

RESUMO

OBJECTIVES: The study was designed to compare pharmacologic and exercise stress during thallium-201 single-photon tomography in a multicenter prospective crossover trial. BACKGROUND: Both exercise and adenosine myocardial perfusion imaging have high sensitivity and specificity for detection of coronary artery disease. However, few data are available comparing these two stress tests in the same patients. METHODS: The study group consisted of 175 subjects: 55 healthy volunteers and 120 patients with suspected coronary artery disease. All subjects underwent two thallium tomographic tests performed 30 days apart, one during intravenous administration of adenosine (140 micrograms/kg per min for 6 min) and one during exercise stress. All images were computer quantified and interpreted without knowledge of the stress test performed. Interpretation agreement was assessed by kappa and Z statistics. RESULTS: Agreement on the presence of normal or abnormal tomograms by adenosine and exercise scintigraphy was 82.8% by visual analysis with kappa and Z statistics of 0.65 (p less than 0.0001) and 11.1 (p less than 0.00001), respectively. The agreement by computer quantification was 86% with kappa and Z statistics of 0.709 (p less than 0.0001) and 12.2 (p less than 0.00001), respectively. Agreement on localization of the perfusion defect to a specific coronary vascular territory varied from 82.7% to 91.4% with highly significant kappa and Z statistics (p less than 0.0001). There was a good correlation between quantified perfusion defect size by adenosine and exercise (r = 0.80, p less than 0.0001), but the values for defect size were significantly greater by adenosine scintigraphy (p = 0.0073). Adenosine side effects were frequent but transient and ceased spontaneously in most subjects within 1 to 2 min after the infusion was discontinued. CONCLUSIONS: Adenosine thallium-201 scintigraphy provides diagnostic information similar to that of exercise scintigraphy, although values for defect sizes are greater with adenosine.


Assuntos
Adenosina , Doença das Coronárias/diagnóstico por imagem , Teste de Esforço , Coração/diagnóstico por imagem , Radioisótopos de Tálio , Tomografia Computadorizada de Emissão de Fóton Único , Doença das Coronárias/epidemiologia , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Sensibilidade e Especificidade
8.
J Am Coll Cardiol ; 18(3): 730-5, 1991 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1869736

RESUMO

Adenosine thallium-201 myocardial scintigraphy is a promising test for coronary artery disease detection, but its safety has not been reported in large patient cohorts. Accordingly, the tolerance and safety profile of adenosine infusion were analyzed in 607 patients (351 men, 256 women, mean age 63 +/- 11 years) undergoing this test either because of suspected coronary artery disease (Group I, n = 482) or for risk stratification early (5.2 +/- 2.8 days) after myocardial infarction (Group II, n = 125). Adenosine increased the heart rate from 74.5 +/- 14.0 to 91.8 +/- 15.9 beats/min (p less than 0.001) and decreased systolic blood pressure from 137.8 +/- 26.8 to 120.7 +/- 26.1 mm Hg (p less than 0.001). Side effects were frequent and similar in both groups. Flushing occurred in 35%, chest pain in 34%, headache in 21% and dyspnea in 19% of patients. Only 35.6% of Group I patients with chest pain during adenosine infusion had concomitant transient perfusion abnormalities, compared with 60.7% of Group II patients (p less than 0.05). First- and second-degree AV block occurred in 9.6% and 3.6% of patients, respectively, and ischemic ST changes in 12.5% of cases. Concomitance of chest pain and ischemic ST depression was uncommon (6%) but, when present, predicted perfusion abnormalities in 73% of patients. Most side effects ceased rapidly after stopping the adenosine infusion. The side effects were severe in only 1.6% of patients and in only six patients (1%) was it necessary to discontinue the infusion. No serious adverse reactions such as acute myocardial infarction or death occurred.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Adenosina , Doença das Coronárias/diagnóstico por imagem , Vasos Coronários/efeitos dos fármacos , Coração/diagnóstico por imagem , Hemodinâmica/efeitos dos fármacos , Adenosina/toxicidade , Dor no Peito/induzido quimicamente , Eletrocardiografia , Estudos de Avaliação como Assunto , Feminino , Bloqueio Cardíaco/induzido quimicamente , Humanos , Masculino , Pessoa de Meia-Idade , Cintilografia , Radioisótopos de Tálio
9.
J Am Coll Cardiol ; 15(2): 318-29, 1990 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-2405036

RESUMO

The clinical utility of exercise thallium-201 single photon emission computed tomography was investigated in 360 consecutive patients who had concomitant coronary arteriography. Tomographic images were assessed visually and from computer-quantified polar maps. Sensitivity for detecting coronary artery disease was comparably high using quantitative and visual analysis, although specificity tended to improve using the former method (87% versus 76%, p = 0.09). Quantitative analysis was superior to the visual method for identifying left anterior descending (81% versus 68%, p less than 0.05) and circumflex coronary artery (77% versus 60%, p less than 0.05) stenoses and detected most patients (92%) with multivessel coronary artery disease. Multivessel involvement was correctly predicted in 65% of the patients with more than one critically stenosed vessel. Exercise variables in patients with significant coronary artery disease were similar whether the tomographic images were normal or abnormal. However, patients with coronary stenoses and normal versus abnormal tomograms had a trend toward more single vessel disease (79% versus 62%, p = 0.07) and moderate coronary stenosis (66% versus 28%, p less than 0.001), but had less proximal left anterior descending artery involvement (8% versus 34%, p = 0.05). Computer-quantified perfusion defect size was directly related to the extent of coronary artery disease. Intra- and interobserver agreement for quantifying defects were excellent (r = 0.98 and 0.97, respectively). In conclusion, quantitative thallium-201 tomography offers improved detection of coronary artery disease, localization of the anatomic site of coronary stenosis, prediction of multivessel involvement and accurate determination of perfusion defect size, while maintaining a high specificity. Quantification of perfusion defects with single photon tomography may become important for assessing the effects of coronary reperfusion and prognostically stratifying patients with coronary artery disease.


Assuntos
Doença das Coronárias/diagnóstico por imagem , Teste de Esforço , Radioisótopos de Tálio , Tomografia Computadorizada de Emissão/normas , Idoso , Angiografia , Angiografia Coronária , Doença das Coronárias/diagnóstico , Vasos Coronários/diagnóstico por imagem , Eletrocardiografia , Estudos de Avaliação como Assunto , Feminino , Previsões , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Análise de Regressão , Sensibilidade e Especificidade
10.
J Am Coll Cardiol ; 12(6): 1573-81, 1988 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2973483

RESUMO

Myocardial imaging with technetium-99m hexakis 2-methoxyisobutyl isonitrile was investigated as a means to assess myocardial infarct size during coronary occlusion and to quantify the extent of salvaged myocardium after coronary occlusion followed by reperfusion. Open chest dogs underwent either a permanent coronary artery occlusion (Group 1, n = 16) or a 2 h occlusion followed by reperfusion (Group 2, n = 15). Animals in both groups were killed 48 h after occlusion. During coronary occlusion, 23 of the 25 dogs that survived the coronary occlusions had abnormal myocardial scintigrams. The scintigraphic perfusion defect size correlated well with the pathologic infarct size (r = 0.85 and 0.95 by planar and tomographic imaging, respectively). The planar scintigraphic defect size, but not the tomographic defect size, overestimated the pathologic size. The planar scintigraphic defect size observed during coronary occlusion was markedly reduced 48 h after reperfusion (24.8 +/- 12.8% to 10.6 +/- 9.7% of the left ventricle, p less than 0.003). The uptake of technetium-99m hexakis 2-methoxyisobutyl isonitrile in the ischemic myocardium increased significantly 48 h after reperfusion (p less than 0.003) and correlated with the increase in regional myocardial blood flow, as assessed by radioactive microspheres (r = 0.83, p less than 0.01). Thus, myocardial imaging with technetium-99m hexakis 2-methoxyisobutyl isonitrile allows reliable demonstration of the presence of acute infarction, estimation of infarct size and quantification of the extent of salvaged myocardium after coronary reperfusion.


Assuntos
Arteriopatias Oclusivas/complicações , Doença das Coronárias/complicações , Infarto do Miocárdio/diagnóstico por imagem , Traumatismo por Reperfusão Miocárdica/diagnóstico por imagem , Compostos Organometálicos , Animais , Cães , Feminino , Masculino , Infarto do Miocárdio/patologia , Cintilografia , Tecnécio Tc 99m Sestamibi
11.
Genetics ; 123(4): 825-36, 1989 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2612897

RESUMO

Mitochondrial DNA of higher animals has been described as an example of extreme efficiency in genome structure and function. Where exceptionally large size molecules have been found (greater than 20 kb), most have occurred as rare variants within a species, suggesting that these variants arise infrequently and do not persist for long periods in evolutionary time. In contrast, all individuals of at least three species of bark weevil (Curculionidae: Pissodes) possess a mitochondrial genome of unusually large size (30-36 kb). The molecule owes its large size to a dramatically enlarged A + T-rich region (9-13 kb). Gene content and order outside of this region appear to be identical to that found in Drosophila. A series of 0.8-2.0-kb repeated sequences occur adjacent to the large A + T rich region and have perhaps played a role in the generation of the large size as well as an unprecedented frequency of size variant heteroplasmy. Every weevil sampled in all three species (n = 219) exhibits anywhere from two to five distinct size classes of mtDNA. The persistence of this large amount of size polymorphism through two speciation events combined with the abundant size variation within individuals suggests that these molecules may not be subject to strong selection for small overall size and efficiency of replication. This pattern of variation contrasts strongly with the conservation of gene content and arrangement in the coding region of the molecule.


Assuntos
DNA Mitocondrial/genética , Insetos/genética , Animais , Evolução Biológica , Mapeamento Cromossômico , Sequências Repetitivas de Ácido Nucleico , Mapeamento por Restrição , Seleção Genética , Simbiose
12.
Bone ; 14(5): 769-78, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8268051

RESUMO

Clinical imaging techniques cannot consistently identify individuals at risk for hip fracture. Individual differences in falling likelihood partly account for these inconsistencies, but it is also thought that microscopic bone changes may play a role. In this study, subcapital, mid-neck, and trochanteric sites from eight young adult (26 +/- 7 years) and nine older (63 +/- 3 years) males were studied using backscattered electron imaging to identify age-related microscopic structural and mineral changes around the cortex. Cortical bone volume (BV(Ct)/TV), cortical void volume (Vd.V(Ct)/TV), hypermineralized bone volume (BV(H-min)/TV), the number of osteons/mm2 (N.On/B.Ar), lacunae/mm2 (N.Lc/B.Ar(Ct)) in the cortex, lacunae/mm2 (N.Lc/B.Ar(H-min)) in the hypermineralized phase, and cortical thickness (Ct.Th) were measured at subcapital, mid-neck, and trochanteric levels. Cortical void volume showed no differences (P = 0.26) between levels in the younger group, but differences (P < 0.05) were observed in the older group, indicating locational osteopenic differences. Cortical thickness differences were greater at the subcapital (27.7%) and mid-neck (25.2%) levels than at the trochanteric level (10.5%). Both age (P = 0.0022) and level-location interaction (P < 0.0001) influenced the hypermineralized bone volume present, with larger hypermineralized regions generally occurring at the thinner superior locations. Significant (P < 0.05) lacunar differences with aging in the hypermineralized phase suggest a necrotic origin. Artifactual cracks occurred preferentially within the hypermineralized phase, indicating localized reductions in fracture toughness, which may provide a site for crack initiation following an impact.


Assuntos
Envelhecimento , Densidade Óssea , Fraturas do Colo Femoral/etiologia , Colo do Fêmur/anatomia & histologia , Adulto , Idoso , Fenômenos Biomecânicos , Calcificação Fisiológica , Colo do Fêmur/fisiologia , Humanos , Masculino , Microscopia Eletrônica , Pessoa de Meia-Idade , Necrose , Fatores de Risco
13.
Bone ; 15(2): 147-52, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-8086231

RESUMO

Age-related mineral changes are associated with material property changes in cortical bone, which may affect its ability to transmit loads and resist fracture from falling. Aging changes in the mineral content of the femoral neck cortical bone are partly determined by osteonal remodeling events. The objective of this study was to measure mineral differences within the osteonal unit in the human femoral neck. In this study, cadaveric femora from male caucasians of two age groups (25 +/- 7, n = 6; 64 +/- 4, n = 6) were sectioned at the midfemoral neck. Using backscattered electron imaging, osteons from each of eight circumferential cortical regions were analyzed to determine osteonal mineral differences between regions, between the two age groups, and due to radial location within the osteons. Graylevel values from the backscattered electron imaging method were calibrated in equivalent ash content (wt%) units to provide a better understanding of the magnitude of differences observed. A pattern (p < 0.05) of decreasing osteonal mineralization was observed with distance from the central Haversian canal. Additionally, osteonal mineralization was highest in the superior (most lateral) regions of the femoral neck from both age groups, indicating that circumferential location is an influencing factor. The average overall equivalent ash content of osteons from the 17-35-yr group was 59.4 +/- 0.4% (mean +/- SE) by weight, while osteons of the group aged 60-71 measured 52.0 +/- 0.4% equivalent ash content, a decrease of 12.4%.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Envelhecimento/patologia , Calcificação Fisiológica , Colo do Fêmur/patologia , Adulto , Idoso , Análise de Variância , Densidade Óssea/fisiologia , Colo do Fêmur/diagnóstico por imagem , Humanos , Masculino , Microscopia Eletrônica de Varredura , Pessoa de Meia-Idade , Osteoporose/patologia , Radiografia
14.
Bone ; 23(3): 275-81, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9737350

RESUMO

Intracortical remodeling in the adult skeleton removes and replaces areas of compact bone that have sustained microdamage. Although studies have been performed in animal species in which there is an existing baseline of remodeling activity, laboratory rodents have been considered to have limited suitability as models for cortical bone turnover processes because of a lack of haversian remodeling activity. Supraphysiological cyclic axial loading of the ulna in vivo was used to induce bending with consequent fatigue and microdamage. Right ulnae of adult Sprague-Dawley rats were fatigue-loaded to a prefailure stopping point of 30% decrease in ulnae whole bone stiffness. Ten days after the first loading, left ulnae were fatigued in the same way. Ulnae were harvested immediately to allow comparison of the immediate response of the left ulna to the fatigue loads, and the biological response of the right leg to the fatigue challenge. Histomorphometry and confocal microscopy of basic fuchsin-stained bone sections were used to assess intracortical remodeling activity, microdamage, and osteocyte integrity. Bone microdamage (linear microcracks, as well as patches of diffuse basic fuchsin staining within the cortex) occurred in fatigue-loaded ulnar diaphyses. Ten days after fatigue loading, intracortical resorption was activated in ulnar cortices. Intracortical resorption occurred in preferential association with linear-type microcracks, with microcrack number density reduced almost 40% by 10 days after fatigue. Resorption spaces were also consistently observed within areas of the cortex in which no bone matrix damage could be detected. Confocal microscopy studies showed alterations of osteocyte and canalicular integrity around these resorption spaces. These studies reveal that: (1) rat bone undergoes intracortical remodeling in response to high levels of cyclic strain, which induce microdamage in the cortex; and (2) intracortical resorption is associated both with bone microdamage and with regions of altered osteocyte integrity. From these studies, we conclude that rats can initiate haversian remodeling in long bones in response to fatigue, and that osteocyte death or damage may provide one of the stimuli for this process.


Assuntos
Remodelação Óssea/fisiologia , Fraturas de Estresse/fisiopatologia , Ulna/fisiologia , Animais , Reabsorção Óssea , Microscopia Confocal , Ratos , Ratos Sprague-Dawley , Ulna/ultraestrutura , Suporte de Carga
15.
J Nucl Med ; 29(3): 293-301, 1988 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-3346739

RESUMO

A portable multiwire gamma camera (MWGC) with enhanced imaging characteristics relative to conventional sodium iodide camera has been evaluated with 178Ta, a short-lived, generator-produced radioisotope (half-life 9.3 min). First-pass radionuclide angiography (FPRA) was performed and results were compared to those obtained with FPRA using a multicrystal camera (MCC) and 99mTc in 38 patients. The overall left ventricular count sensitivity (counts/mCi/sec/millisteradians [msr]) was significantly higher with MWGC/178Ta (176 +/- 132 versus 108 +/- 49, p less than 0.001) yielding images of higher statistics with higher resolution collimation (31 versus 63 msr). Left ventricular ejection fraction was 0.54 +/- 0.18 by MWGC and 0.54 +/- 0.18 by MCC with an excellent correlation between the two techniques (r = 0.94, s.e.e. = 0.06). The detection of wall motion abnormality was virtually identical with the two techniques. Intra- and interobserver reproducibility by MWGC was excellent (r = 0.99 and 0.99, respectively). Thus, this new technology provides first-pass studies of higher statistical quality and improved resolution, affording more precise assessment of left ventricular performance and likelihood of further substantial improvement by use of even higher doses of 178Ta.


Assuntos
Radioisótopos , Angiografia Cintilográfica/instrumentação , Tantálio , Adulto , Idoso , Idoso de 80 Anos ou mais , Doença das Coronárias/diagnóstico por imagem , Doença das Coronárias/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Contração Miocárdica , Volume Sistólico , Tecnécio
16.
Insect Biochem Mol Biol ; 26(3): 235-47, 1996 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8900595

RESUMO

All or part of the alpha-esterase gene cluster in Drosophila melanogaster has been isolated by screening a YAC clone that spans cytological region 84D3-10 with consensus carboxyl/cholinesterase oligonucleotides. The cluster encompasses 11 putative esterase genes within 65 kb of genomic DNA and is one of the largest clusters of related protein-coding genes yet reported in Drosophila. The cluster must include the gene encoding the major alpha-esterase isozyme, EST9, which has previously been mapped to 84D3-5. It probably also includes the genes encoding the EST23, MCE and ALI esterases that have previously been mapped to 84D3-E2. The latter three are homologs of genes involved in organophosphate insecticide resistance in the sheep blowfly, Lucilia cuprina and the housefly, Musca domestica. Sequencing of one of the putative esterase genes in the Drosophila cluster, alpha E1, shows that it would encode features characteristic of an active carboxyl/cholinesterase, including the so-called catalytic triad, the nucleophilic elbow and oxyanion hole. It also shows that the closest relative of alpha E1 amongst previously published esterase sequences is ESTB1, which confers organophosphate resistance in Culex mosquitoes. We argue that we have cloned the D. melanogaster version of a major cluster of esterase genes which have variously mutated to confer organophosphate resistance in diverse Diptera.


Assuntos
Mapeamento Cromossômico , Drosophila melanogaster/enzimologia , Drosophila melanogaster/genética , Esterases/genética , Genes de Insetos/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Passeio de Cromossomo , Cromossomos , Cromossomos Artificiais de Levedura , Clonagem Molecular , Dados de Sequência Molecular , Família Multigênica , Homologia de Sequência de Aminoácidos
17.
Science ; 252(5007): 763, 1991 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-17744249
18.
J Orthop Res ; 16(3): 322-9, 1998 May.
Artigo em Inglês | MEDLINE | ID: mdl-9671927

RESUMO

When compact bone is subjected to fatigue loading, it develops matrix microdamage, which reduces the tissue's ability to resist fracture. The relative influence of different strain modes on damage and strength in compact bone has not been characterized, to our knowledge. In this study, the nonuniform strain field produced by four-point bending was used to introduce fatigue damage into tibial bending beam specimens from men 40-49 years old. The specimens were then bulk-stained with basic fuchsin to mark damage surfaces and were examined histologically and with confocal microscopy to describe damage morphologies and position relative to tension and compression-strained regions of the specimen. Histomorphometric methods were used to quantify the amounts of different types of bone microdamage. Three major types were observed. In regions subjected to tensile strains, the bone had focal regions of diffusely increased basic fuchsin staining (i.e., diffuse microdamage). Confocal microscopy of these regions showed them to be composed of extensive networks of fine, ultrastructural-level cracks. In compressive strain regions, the tissue developed linear microcracks in interstitial areas similar to those originally described by Frost. Fine, tearing-type (wispy-appearing) cracks were observed near and in the plane of the neutral axis. The paths of these fine cracks were not influenced by microstructural boundaries. Other minor damage morphologies (sector-stained osteons, delamination of regions of lamellae, and intraosteonal cracking) were observed, but their distribution was unrelated to local strain field. Thus. in fatigue of human compact bone, the principal mechanisms of matrix failure (i.e., linear microcrack, diffuse damage foci, and tearing-type damage) are strongly dependent on local strain type.


Assuntos
Osso e Ossos/patologia , Fraturas de Estresse/patologia , Adulto , Fraturas de Estresse/etiologia , Humanos , Masculino , Pessoa de Meia-Idade
19.
Am Psychol ; 49(1): 15-24, 1994 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8122813

RESUMO

Socioeconomic status (SES) is consistently associated with health outcomes, yet little is known about the psychosocial and behavioral mechanisms that might explain this association. Researchers usually control for SES rather than examine it. When it is studied, only effects of lower, poverty-level SES are generally examined. However, there is evidence of a graded association with health at all levels of SES, an observation that requires new thought about domains through which SES may exert its health effects. Variables are highlighted that show a graded relationship with both SES and health to provide examples of possible pathways between SES and health end points. Examples are also given of new analytic approaches that can better illuminate the complexities of the SES-health gradient.


Assuntos
Comportamentos Relacionados com a Saúde , Nível de Saúde , Fatores Socioeconômicos , Humanos , Estilo de Vida , Transtornos Psicofisiológicos/psicologia , Estresse Psicológico/complicações
20.
Biomed Pharmacother ; 54(4): 210-8, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10872719

RESUMO

Despite the availability of inactivated influenza vaccines, influenza continues to cause considerable mortality in the elderly, and morbidity in all age groups. Cold-adapted, live-attenuated, intranasally administered influenza vaccines, first developed in the 1960s, have been tested in more than 10,000 volunteers and have been shown to be safe, well-tolerated, and immunogenic. Recent trials suggest that efficacy in children may be superior to that of inactivated vaccines, and efficacy in healthy adults may be similar to that of inactivated vaccines, although there are limited data comparing the two vaccines directly. Advantages of the live-attenuated vaccines include acceptability, ease of administration, and the potential for mass immunization. The possibility of substantially higher vaccination rates across all age groups brings promise for the development of herd immunity and greatly improved control of influenza in the future.


Assuntos
Vacinas contra Influenza/imunologia , Administração Intranasal , Humanos , Vacinas contra Influenza/administração & dosagem , Vacinas contra Influenza/efeitos adversos , Vacinas Atenuadas/imunologia
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