永久起搏器在预防心房颤动中的作用

本文总结了用于预防和终止心房颤动的起搏器的类型。窦房结功能异常的病人,心室起搏与较高的心房颤动的发生率相关。有鉴于此,有心房颤动病史、因心动过缓而需要安装起搏器的病人,应该安装双腔或心房起搏生理性起搏器,而不应安装单腔的心室起搏器。     

Role of negative pressure wound therapy in total hip and knee arthroplasty

Negative-pressure wound therapy(NPWT) has been a successful modality of wound management which is in widespread use in several surgical fields. The main mechanisms of action thought to play a role in enhancing wound healing and preventing surgical site infection are macrodeformation and microdeformation of the wound bed, fluid removal, and stabilization of the wound environment. Due to the devastating consequences of infection in the setting of joint arthroplasty, there has been some interest in the use of NPWT following total hip arthroplasty and total knee arthroplasty. However, there is still a scarcity of data reporting on the use of NPWT within this field and most studies are limited by small sample sizes, high variability of clinical settings and end-points. There is little evidence to support the use of NPWT as an adjunctive treatment for surgical wound drainage, and for this reason surgical intervention should not be delayed when indicated. The prophylactic use of NPWT after arthroplasty in patients that are at high risk for postoperative wound drainage appears to have the strongest clinical evidence. Several clinical trialsincluding single-use NPWT devices for this purpose are currently in progress and this may soon be incorporated in clinical guidelines as a mean to prevent periprosthetic joint infections.     

Measuring psychological well-being. The Adapted General Well-being Index in a primary care setting: a test of validity

The measurement of health outcomes is central to the developmentof health services. Many acute and chronic illnesses and healthinterventions have implications for mental health. This studytests the validity of a 22 item measure of psychological well-being,the adapted general well-being index (AGWBI). A postal healthsurvey, including the AGWBI, was sent to a 10% random sampleof patients aged 16 or over drawn from the computerized listof one general practice. Two hundred and sixty-six respondentsreturned questionnaires (a response rate of 76%). The AGWBIwas fully completed by 94% (249) of the respondents who returnedtheir questionnaires. Only respondents who fully completed theAGWBI are included in the analysis. The AGWBI significantlydiscriminated people with a limiting long term illness, thosereporting suffering from anxiety, depression or bad nerves,users of general practitioner services over the previous twoweeks and respondents reporting taking antidepressants, tranquillizersor sleeping tablets. It was also able to discriminate respondentswith psychosocial difficulties in a small sub-sample who reportedthat they were in excellent health and did not have a limitinglong term health problem or psychological illness. The resultsare broadly supportive of the validity of the AGWBI and suggestit may be appropriate for use in the evaluation of several developingareas of primary care. Further research is needed to test concurrentvalidity, responsiveness and to establish population norms.     

T2 estimates in healthy and diseased brain tissue: a comparison using various MR pulse sequences

Fourteen patients and five healthy individuals underwent magnetic resonance (MR) imaging to determine an effective multiple spin echo pulse sequence for estimating T2. Lesions examined included infarction, glioma, multiple sclerosis, and acute hematoma. A pulse repetition time (TR) of 1,500 msec and echo delays (TEs) of 25, 50, 75, and 100 msec were used. Computed T2 images were derived from all four echoes, the first two echoes, and the first and fourth echoes. T2 values were obtained from specific brain locales using region-of-interest analysis. Use of either the first two echoes or the first and fourth in the T2 fit provided T2 estimates which closely correlated with that of the four-echo analysis. The noise level in T2 maps constructed from the 25- and 100-msec echoes was modestly (typically 10%) higher than that from four echoes; noise level from the 25- and 50-msec echoes was markedly higher, typically 60%. This behavior is remarkably consistent with that predicted from theory. All 19 subjects displayed consistent relative T2 values for specific brain structures; in 13, the absolute T2 values fell within a limited range. Despite the high sensitivity of T2 images, their specificity in the detection of most brain disease appears limited except in acute intracerebral hematoma, which exhibited a decreased T2 relaxation time using high-field-strength MR imaging.     

The Inter-Regional, Epidemiological Study of Childhood Cancer (IRESCC): case-control study in children with germ cell tumours

In 1980–1983 members of IRESCC interviewed parents of555 children with newly diagnosed cancer on topics of possibleaetiological significance. Identical questions were asked ofthe parents of 1100 control children chosen from hospital admissionsand general practitioner lists. Medical information was confirmedwhenever possible by cross-checking with NHS records. Data forthe 41 children with germ cell tumours and their 82 controlsare reported here. The cases had more major congenital malformationsthan controls, including one neural tube defect. More case thancontrol mothers and fathers reported occupational exposure tochemicals. Nine close relatives of cases had multiple primarytumours, which were often benign or of low-grade malignancy,compared with 1 hospital control and 3 general practitionercontrol relatives. Cases and controls differed with respectto birth weight and paternal age. No case-control differenceswere shown for: birth rank, maternal age, chronic illnessesand smoking, mothers' reproductive histories and oral contraceptiveusage. In index pregnancies there were no case-control differencesfor maternal illness, infections, alcohol intake and X-ray andultrasound exposure. There was no difference between cases andcontrols for the frequency of twinning the families.     

Community characteristics associated with elevated blood lead levels in children

OBJECTIVES: To identify community characteristics associated with children having elevated blood lead levels (> or = 10 micrograms/dL) and examine whether these characteristics can be used to identify children with elevated blood lead levels. PARTICIPANTS AND SETTING: A total of 20,296 children in Monroe County, New York (< 6 years old) who had blood lead testing in the first 12 months after statewide mandated reporting of blood lead tests began. DESIGN: A logistic regression analysis was conducted to examine the association of children's blood lead levels and community characteristics by using community characteristics of 653 census block groups. RESULTS: The following community level variables were associated with increased risk of elevated blood lead levels in children: residence within the city [odds ratio (OR), 2.0; 95% confidence interval (CI), 1.6, 2.7]; block groups with a higher proportion of individuals of Black race (OR, 1.6; CI, 1.4, 2.0); higher screening rate (OR, 1.9; CI, 1.6, 2.4); lower housing value (OR, 1.6; CI, 1.2, 2.0); housing built before 1950 (OR, 1.5; CI, 1.3, 1.8); higher population density (OR, 1.5; CI, 1.3, 1.8); higher rates of poverty (OR, 1.4; CI, 1.2, 1.8); lower percent of high school graduates (OR, 1.3; CI, 1.1, 1.6), and lower rates of owner-occupied housing (OR, 1.2; CI, 1.0, 1.4). Community characteristics were comparable with clinic-based individual risk assessment to identify children with elevated blood lead levels. CONCLUSIONS: These data demonstrate that community characteristics can be used to develop screening strategies to identify children who have elevated blood lead levels and shift our efforts toward identifying houses containing lead hazards before occupancy and before children are unduly exposed.     

Immunoradiometric assay of thyrotropin as a "first-line" thyroid-function test in the routine laboratory

We compared the utility of a sensitive immunoradiometric assay for serum thyrotropin as a "first-line" thyroid-function test with a strategy based on first measuring total thyroxin in serum. The immunoradiometric assay appears to distinguish primary hypothyroidism and hyperthyroidism from euthyroidism in "new" patients. The role of this test in monitoring antithyroid treatment or thyroxin-replacement therapy is not yet established, there being particular difficulty in interpreting low thyrotropin concentrations in such patients. Nevertheless, because a normal thyrotropin concentration in most, if not all, situations signifies the euthyroid state, thyrotropin determination by immunoradiometric assay merits consideration as an initial test by laboratories performing thyroid-function tests.