Economic evaluation of treatments for respiratory disease

Considerable quantities of health service resources are being devoted to tackling the problems posed by respiratory diseases and this can be expected to continue as the prevalence of such diseases increases. This paper provides an assessment of the most efficient use of these healthcare resources by reviewing the literature on economic evaluation relating to interventions in the field of respiratory medicine. Currently, this literature largely comprises cost-minimisation studies of both management and educational interventions. Asthma educational interventions, whether targeted at adults or children, appear to be effective in improving patient self-management and adherence to medications, and appear to be associated with a lower overall use of healthcare resources. In terms of management interventions the overall picture is rather less clear although there is some support for the greater efficiency of patient administration of beta-adrenergic agonists by metered dose inhalers over therapist-administered up-draft nebulisation. Two features of respiratory disease make evaluation in this field somewhat unusual: there are alternative methods of delivering therapy to patients, which makes patient compliance an important issue, and since most respiratory diseases are chronic conditions the long-term effectiveness of interventions must be assessed. The scarcity of cost-effectiveness and cost-utility studies in this field may, in part, reflect the difficulties of measuring outcomes in respiratory disease.     

The magnetic resonance imaging appearances of the brain in acute carbon monoxide poisoning

AIMS: To describe the magnetic resonance imaging (MRI) appearances of the brain in acute carbon monoxide poisoning, the commonest cause of accidental poisoning in Europe and the U.S.A. To attempt to correlate the imaging findings with patient outcome as an aid to prognosis. MATERIALS AND METHODS: Brain MRI was performed on 19 consecutive patients, who had sustained acute carbon monoxide poisoning, as soon as possible after their referral to the regional Hyperbaric Unit at the Royal Hospital, Haslar. All patients were unconscious on arrival, and had received at least one treatment with hyperbaric oxygen by the time of first MR. The imaging findings were analysed independently by two experienced MR radiologists, with a third radiologist arbitrating on discrepant results. RESULTS: Thirteen male and six female patients, age range 21-70 years (mean 38.7 years) underwent MR an average of 35.6 h (range 6-126 h) following presentation at the referring centre. MR (at 0.5T) revealed abnormalities in the following areas: globus pallidus (n = 12); other basal ganglia [ n = 5: entire lentiform (globus pallidus and putamen), putamen alone, caudate nucleus, thalamus]; white matter (n = 6: periventricular, subcortical, other); cerebral cortex (n = 5), either localized or general; medial temporal lobe in the region of the hippocampus (n = 4). The majority of the patients with hyperintensity in the region of the hippocampus (n = 3) had no other area of cortical involvement. Two patients showed abnormalities in the cerebellum. Normal appearances were seen on the initial MR in seven patients. CONCLUSION: The appearances of the brain following acute CO poisoning are varied, and have previously been the subject of case reports or small studies, most of which have have addressed the delayed sequelae of this condition. This study, the first large series undertaken in the acute phase, confirms that, although the globus pallidus is the commonest site of abnormality in the brain, the effects of CO poisoning are widespread. The extent of damage correlates with clinical outcome, and therefore aids management and prognosis.     

Outcome of children with respiratory symptoms without objective evidence of asthma: a two-year, prospective, follow-up study

This study evaluated the outcome of 33 children with asthma-like symptoms without objective evidence of asthma, and the role of certain factors in predicting the development of clinical asthma in these children. Data on symptom histories, lung functions (flow-volume spirometry, free running test and methacholine inhalation challenge test) and atopic sensitization (skin prick tests and markers of eosinophilic inflammation) were collected twice with an interval of 2 y, and the diagnoses were re-evaluated after the follow-up period. Based on the results, it was concluded that one-third of the children with prolonged or recurrent lower airway symptoms, such as cough or wheeze, either have mild asthma or will develop asthma in the near future. Children who had a significant response [≥ 10% fall in forced expiratory volume in 1 s (FEV1)] in the free running test formed a risk group for active asthma, whereas other baseline characteristics seemed not to predict the outcome.     

Randomized trial examining cerebral haemodynamics following artificial or animal surfactant

To determine the effects of animal and artificial surfactants on cerebral haemodynamics, 20 premature babies receiving mechanical ventilation were randomized to receive Curosurf or Exosurf surfactant. Anterior cerebral artery blood flow velocity (CABFV) was measured using Doppler ultrasound before and up to 2 h after treatment. Following animal surfactant there was a rapid reduction in CABFV (median -36%, range -43% to +8%, p < 0:01), whereas artificial surfactant resulted in a slower rise which was less marked (median +20%, range -7% to +62%, p < 0:05). There were no significant changes in blood pressure. Two hours after administration, the oxygenation index (OI) improved significantly only in babies receiving animal surfactant. In this group there was a significant association between the change in CABFV at 1 min and the change in OI at 2 h ( r = 0:66, p < 0:05). Animal surfactant produces rapid improvements in ventilation which are associated with marked alterations in cerebral haemodynamics.     

Allosteric effectors of hemoglobin as modulators of chemotherapy and radiation therapy in vitro and in vivo

Introduction: A series of molecules designed to be allosteric effectors of hemoglobin were examined for their potential as radiation sensitizers in vitro and in vivo and for their potential as chemosensitizers in vivo as well as for their antimetastatic effect. Results: At a concentration of 100 μM for 1 h prior to, during and for 1.5 h after radiation exposure, the allosteric effectors decreased the shoulder of the radiation survival curve of normally oxygenated EMT-6 cells and increased the slope of the radiation survival curves of hypoxic EMT-6 cells resulting in dose-modifying factors of 1.8 to 2.1. In vivo the allosteric effectors had antitumor activity against the Lewis lung carcinoma and produced primarily additive tumor growth delay when administered along with fractionated radiation therapy. When administered on days 4 through 18 after tumor implantation, the allosteric effectors, especially JP-7, RSR-13 and RSR-4, were highly effective antimetastatic agents in animals bearing Lewis lung carcinoma. In cell culture, simultaneous exposure to the allosteric effectors (at 100 μM ) effectively sensitized EMT-6 cells to the effects of 4-hydroperoxycyclophosphamide, thiotepa and carboplatin. The allosteric effectors were not very cytotoxic toward EMT-6 tumor cells from tumors treated in vivo with single doses of each molecule nor were these agents very cytotoxic toward bone marrow CFU-GM taken from the same animals. Conclusions: It is likely that the allosteric effectors have a molecular target in addition to hemoglobin. Other possible targets include hydroxymethyl-glutaryl-CoA reductase or microsomal cytochrome b₅. Received: 27 June 1997 / Accepted: 8 October 1997     

Postremission therapy for children with acute myeloid leukemia: the children's cancer group experience in the transplant era.

We reviewed consolidation therapy results and analyzed postremission outcomes for 1464 children less than 21 years old at diagnosis in five consecutive Children's Cancer Group acute myeloid leukemia trials between 1979 and 1996. Children in remission were allocated to allogeneic bone marrow transplantation (BMT) (N=373) in first remission, if a matched family donor was available. Remaining children were assigned consolidation chemotherapy (N=688) or autologous purged BMT (N=217), or withdrew from study before assignment, or with unknown data (N=186). Overall and disease-free survival were superior for children assigned allogeneic transplants. High (>50,000/microl) diagnostic white blood cell (WBC) count was prognostic for inferior outcome, but French-American-British (FAB) subtypes were not. Inv(16) is a favorable karyotypic feature for children in first remission and t(8;21) is not. Allogeneic transplantation benefit was evident in most children, including those with high or low diagnostic WBC count, each FAB subtype, and t(8;21), but was not seen in children with inv(16). Therefore, these data suggest reserving matched related donor allogeneic transplantation for children with inv(16) for second remission, but not those with t(8;21).     

海风藤的原植物——腺鳞蒟与山药的比较研究

本文对模式产地的山药Piper haneei Maxim, var, hancei Maxim,和腺鳞蒟P. kancei Maxim var. squamiglanduferum Fan var. nov.进行了原植物形态特征和花序轴、花序梗、茎、叶的显微特征以及化学成分的TLC及UV比较。挥发油的GC—MS研究共鉴定出38个成分,其中28个是胡椒属植物中首次报道的成分。结果证明了在福建长期以来被认为是山药的腺鳞蒟与模式产地的山药有较大差别,尤其是腺鳞蒟叶上表面有腺鳞,是迄今为止第1个发现具有腺鳞的胡椒属植物。据此把腺鳞蒟作为新变种从山药中分出。腺鳞药是福建南部海风藤主要来源之一。