Solitary pulmonary nodules: CT assessment

Computed tomography (CT) was used to examine 634 solitary pulmonary nodules (SPNs). Each lesion was assessed as benign or indeterminate on the basis of CT criteria. Benign nodules made up 44% of all SPNs and 58% of the 431 that were 2 cm or less in diameter. All malignant SPNs were assessed as indeterminate, and adenocarcinoma (42%) was the most common primary malignancy. A total of 176 (63% of benign SPNs) were correctly assessed as benign by CT. Ninety SPNs assessed as diffusely calcified were not so identified by conventional tomography at outside institutions. An SPN can be reliably assessed by CT as benign if it exhibits high attenuation values, exceeding a critical level and distributed diffusely throughout a CT section through the center of the lesion and a well-defined edge. Although 38 of 283 (13.4%) primary lung cancers contained localized calcification, there was no significant overlap with the diffuse calcification of benign lesions. Central carcinoid tumors may contain focal ossification, but such lesions may be recognized by noting the proximity of larger bronchi. Assessment of SPNs by CT is most effective for lesions 2.0 cm or less in diameter. For larger lesions, the frequency of benign disease was decreased (14.3% of 203), as was the percentage of benign SPNs correctly assessed as benign by CT (37.9%).     

Mutational scanning of large genes by extensive PCR multiplexing and two-dimensional electrophoresis: application to the RB1 gene

With the rapid increase in the number of identified human disease genes, the development of accurate and cost-efficient mutation tests has become opportune. Here we present a combination of extensive PCR multiplexing and two-dimensional (2-D) DNA electrophoresis to screen for mutations in 26 exons of the retinoblastoma (RB1) tumor suppressor gene. In 2-D electrophoresis, fragments are separated according to size and base pair sequence in non-denaturing and denaturing gradient gels, respectively. All target fragments, designed to have optimal melting characteristics, were prepared in a two-step PCR (a 6-plex long-PCR pre- amplification and a subsequent 25-plex short-PCR) followed by heteroduplexing. The mixture of PCR amplicons was then subjected to 2-D electrophoresis under a single set of experimental conditions. With this design, 35 previously identified mutations in 18 different exons were detected in 33 bilateral retinoblastoma patients. These results suggest that 2-D electrophoresis in this format provides a generally applicable, practical and fast way to diagnose with high accuracy large genes for a broad spectrum of possible disease-causing mutations.      

Relationship between image quality and ultrasound exposure level in diagnostic US devices

Ultrasonographic B-mode images were obtained at various exposure levels with three real-time diagnostic scanners. Adult human and tissue-equivalent phantom images were compared in terms of diagnostic content and depth of penetration. For the exposure level settings used, spatial-peak pulse-average intensities ranged from approximately 10 to 500 W/cm2. At the 3.50-3.75-MHz nominal frequencies used in the study, images of the human abdomen showed little discernible change in quality with varying exposure levels. However, phantom tests confirmed that depth of penetration is a function of exposure level. The results suggest that a judicious use of exposure level and receiver gain controls can be a practical means for minimizing patient exposure to ultrasound without sacrifice of diagnostic effectiveness.     

男性不育症精浆中超氧化物歧化酶、锌、睾酮含量的研究

本文采用一种简便灵敏的改良邻苯三酚法测定了236例不育症患者和27例正常育龄男子精浆中铜锌超氧化物歧化酶(CuZn-SoD)含量,同时还测定了精浆锌(Zn)和睾酮(T)含量。结果表明:在不育症精浆中,CuZn-SOD、Zn、T与精子密度之间均有显著正相关(P<0.01);CuZn-SOD和Zn含量与精子活动度均有密切关系,含量高活动度也高(P<0.001);CuZn-SOD和Zn之间亦存在显著正相关(P<0.01). 在精子密度范围同60～100×10~6/ml时.不育组与生育组精浆中CuZn-SOD、Zn、T含量均无统计学差异(P<0.2).本究究提示.CuZn-SOD作为精浆保护因子,通过抑制类脂过氧化反应使精子免受损伤。精浆CuZn-SOD含量测定有可能作为衡量精液质量的新指标。应用SOD类制剂治疗男性不育症可能有裨益。     

Evaluation of an individualised asthma programme directed at behavioural change.

An individualised asthma programme directed at behavioural change was evaluated in asthmatic subjects who reported complaints and impairment, despite adequate medical treatment. Mild-to-moderate asthma patients (n=23) were randomly assigned to a programme or waiting list condition. Outcome measures were: McMaster Asthma Quality of Life Questionnaire, Asthma Symptom Checklist, Negative Emotionality Scale, Knowledge, Attitude and Self-Efficacy Asthma Questionnaire, Adherence Scale, and peak flow measurements. Both groups were evaluated at three consecutive moments, each separated by 3 months; the programme was delivered between the first two evaluations. At onset the patient received a workbook containing information, exercises and homework assignments. Psycho-education, behavioural and cognitive techniques were introduced during six 1-h individual sessions. Compared with controls the programme group reported less symptoms (obstruction, fatigue), better quality of life (activity, symptoms, emotions), decreased negative affectivity, and increased adherence, immediately after finishing the programme and at 3 months follow-up. All three cognitive variables (knowledge, attitude towards asthma, self-efficacy) and day and night peak flow ratings improved in the programme group but not in the waiting list group. Participation in an individualised programme resulted in improvement of asthma morbidity, and asthma-related behaviour and cognitions, in subjects reporting symptoms and impairment despite adequate medical therapy.     

UK childbirth delivery options in 2001–2002: alternatives to consultant unit booking and delivery

BACKGROUND: Government policy advocates maternal choice in pregnancy care. Two key issues are place of birth and type of lead professional. Anecdotal evidence suggests there is variation in both these issues across the UK, but there has been no recent national assessment of whether maternal options are in line with government policy. AIM: To establish the range of women's childbirth delivery options, degree of midwife autonomy, and supporting training and governance mechanisms. DESIGN: Two postal questionnaires. SETTING: UK maternity units. METHOD: Questionnaires were sent to maternity services managers. MAIN OUTCOME MEASURES: number and type of units and births, transfers and care types; midwifery procedures; clinical governance and training activities. RESULTS: Completed questionnaires were received from 301 out of 308 (97.7%) units in 2002 and from 258 out of 309 (83.5%) units in 2001. Midwife-led care is available in 186 English (76.9%), 15 Welsh (78.9%), 18 Scottish (48.6%) and three Northern Ireland (30.0%) units. There are 73 (24.3%) stand-alone, 22 (7.3%) alongside, 127 (42.2%) integrated and 79 (26.2%) consultant units (for definitions of unit types, see main text), with a median 2215 hospital, 25 home and 210 midwife-led births. The median antenatal and labour transfers from midwife-led units are 25.5% (interquartile range [IQR] = 18.5-36.5%) and 18.0% (IQR = 13.4-24.8%) respectively; transfers are independent of distance to nearest consultant unit, country and unit type. CONCLUSIONS: Despite government policy promoting greater parental choice, this is not in evidence in many parts of the UK. The wide variations in home birth, midwife-led care and maternity-unit types merit further exploration. If more midwife-led units are to be established as a way of promoting parental choice and dealing with junior doctor rota problems, then such units must have adequate governance and training activities in place.     

Epstein-Barr virus-associated hemophagocytic syndrome: virological and immunopathological studies

The virus-associated hemophagocytic syndrome (VAHS) is a disorder characterized by a benign, generalized histiocytic proliferation, with marked hemophagocytosis associated with systemic viral infections. We have studied the virological and immunopathological events occurring in two children experiencing Epstein-Barr VAHS. Neither of the patients had an underlying immunodeficiency and both recovered from their disease and are completely well one year after follow-up. In each patient, evidence for primary Epstein-Barr virus (EBV) infection was documented with a typical humoral immune response, including IgM antibody directed against virus capsid antigen. EBV was demonstrated in lymphoreticular tissues by electron microscopy and molecular hybridization studies. Permissive EBV infection was suggested by the finding of mature virus particles and linear viral DNA in lymphoreticular tissues. Immunopathological studies demonstrated complete effacement of lymph node architecture by a marked proliferation of immunoblasts in patient 1 and infiltration and effacement of the lymph node architecture with benign-appearing histiocytes in patient 2. Atypical lymphocytes characteristic of acute EBV infection were notably absent in the peripheral blood of both patients and cytotoxic T cells, which normally lyse EBV-infected B cells, were also absent from the peripheral circulation. Our observations suggest that EBV-induced VAHS may be the result of an increased virus burden in the face of immunoregulatory cell imbalances.