2841. Progression, remission, regression of chronic renal diseases.
The prevalence of chronic renal disease is increasing worldwide. Most chronic nephropathies lack a specific treatment and progress relentlessly to end-stage renal disease. However, research in animals and people has helped our understanding of the mechanisms of this progression and has indicated possible preventive methods. The notion of renoprotection is developing into a combined approach to renal diseases, the main measures being pharmacological control of blood pressure and reduction of proteinuria. Lowering of blood lipids, smoking cessation, and tight glucose control for diabetes also form part of the multimodal protocol for management of renal patients. With available treatments, dialysis can be postponed for many patients with chronic nephropathies, but the real goal has to be less dialysis-in other words remission of disease and regression of structural damage to the kidney. Experimental and clinical data lend support to the notion that less dialysis (and maybe none for some patients) is at least possible.
2842. WHO systematic review of randomised controlled trials of routine antenatal care.
作者: G Carroli.;J Villar.;G Piaggio.;D Khan-Neelofur.;M Gülmezoglu.;M Mugford.;P Lumbiganon.;U Farnot.;P Bersgjø.; .
来源: Lancet. 2001年357卷9268期1565-70页
There is a lack of strong evidence on the effectiveness of the content, frequency, and timing of visits in standard antenatal-care programmes. We undertook a systematic review of randomised trials assessing the effectiveness of different models of antenatal care. The main hypothesis was that a model with a lower number of antenatal visits, with or without goal-oriented components, would be as effective as the standard antenatal-care model in terms of clinical outcomes, perceived satisfaction, and costs.
2844. Herpes simplex virus infections.
Herpes simplex virus (HSV) is a member of the herpesviridae family. Recognised since ancient Greek times, the virus frequently infects human beings, causing a range of diseases from mild uncomplicated mucocutaneous infection to those that are life threatening. In the past 50 years, substantial advances in our knowledge of the molecular biology of HSV have led to insights into disease pathogenesis and management. This review provides a contemporary interpretation of the biological properties, function, epidemiology, and treatment of HSV diseases.
2848. Effect of sex hormones on cardiac mass.
Increased left-ventricular mass is an important cardiovascular risk factor for morbidity and mortality. Apart from obvious differences in cardiac size, the changes in left-ventricular mass in response to age and hypertrophic stimuli are very different in men and women. Whereas left-ventricular mass increases with age in apparently healthy women, it remains constant in men. Under increased cardiac loading conditions, such as hypertension or aortic stenosis, this disparity between sexes is even more striking. Findings are especially pronounced in people aged 50 years or older, in whom reproductive hormone concentrations have fallen. Whether the differences in left-ventricular mass changes are related to endogenous sex-hormone concentrations has never been shown. Androgens have anabolic effects on cardiac cells, and oestrogens have antiproliferative properties, we therefore postulate that the normal decline in endogenous sex hormones with age has contrary effects on ventricular mass in men and women in normal and pathological states.
2849. Improving interpretation of clinical studies by use of confidence levels, clinical significance curves, and risk-benefit contours.
The process of interpreting the results of clinical studies and translating them into clinical practice is being debated. Here we examine the role of p values and confidence intervals in clinical decision-making, and draw attention to confusion in their interpretation. To improve result reporting, we propose the use of confidence levels and plotting of clinical significance curves and risk-benefit contours. These curves and contours provide degrees of probability of both the potential benefit of treatment and the detriment due to toxicity. Additionally, they provide clinicians with a mechanism of translating the results of studies into treatment for individual patients, thus improving the clinical decision-making process. We illustrate the application of these curves and contours by reference to published studies. Confidence levels, clinical significance curves, and risk-benefit contours can be easily calculated with a hand calculator or standard statistical packages. We advocate their incorporation into the published results of clinical studies.
2850. The implantable cardioverter defibrillator.
Implantable cardioverter defibrillators (ICDs) have evolved from the treatment of last resort to the gold standard therapy for patients at high risk for ventricular tachyarrhythmias. High-risk patients include those who have survived life-threatening arrhythmias, and individuals with cardiac diseases who are at risk for such arrhythmias, but are symptomless. Use of an ICD will affect the patient's quality of life. Some drugs can substantially affect defibrillator function and efficacy, and possible drug-device interactions should be considered. Patients with ICDs may encounter cell phones, antitheft detectors, and many other sources of potential electromagnetic Interference. In addition to treating ventricular tachyarrhythmias, new defibrillators provide full featured dual chamber pacing, and could treat atrial arrhythmias, and congestive heart failure by means of biventricular pacing.
2851. Systemic lupus erythematosus.
This review covers major advances in clinical issues related to systemic lupus erythematosus (SLE) published between 1995 and 2000. The classification criteria for both SLE and antiphospholipid syndrome (APS) have been updated, and up to 19 different subsets of neuropsychiatric lupus have been defined. New epidemiological data show that the incidence of new cases and the survival of patients with SLE are both increasing. Several randomised controlled trials have defined the role of cyclophosphamide, methotrexate, antimalarials, and hormonal treatment in the management of SLE. New data are available for drugs such as ciclosporin and thalidomide. Finally, several new treatments for severe refractory cases, such as mycophenolate mofetil and stem-cell transplantation, are being increasingly used. New data also refer to management of thrombosis in APS and high-risk pregnancies in women with SLE or APS.
2852. Geographical differences in invasive pneumococcal disease rates and serotype frequency in young children.
The development of glycoconjugate vaccines for Streptococcus pneumoniae that are effective in very young children has renewed interest in identification of which among the more than 90 pneumococcal serotypes are most likely to cause invasive pneumococcal disease (IPD). Serotype distribution is thought to vary geographically, even between regions as socioeconomically similar as western Europe and North America. To explain these variations, we note the considerable variation that exists between reported rates of IPD in young children in the USA and west European countries. We postulate that this variation is attributable to different blood-culture rates and practices, and that mild IPD is probably underdiagnosed and under-reported in western Europe. On the basis of a comparison of serotype distributions between the two regions, we also postulate that those serotypes found at similar frequencies in both regions are virulent and rarely cause mild disease. As a result, reported distributions of IPD serotypes, especially when expressed as percentages, might be strongly skewed by the distribution of clinical presentations in a particular study population.
2853. Assessment of clinical competence.
Tests of clinical competence, which allow decisions to be made about medical qualification and fitness to practise, must be designed with respect to key issues including blueprinting, validity, reliability, and standard setting, as well as clarity about their formative or summative function. Multiple choice questions, essays, and oral examinations could be used to test factual recall and applied knowledge, but more sophisticated methods are needed to assess clincial performance, including directly observed long and short cases, objective structured clinical examinations, and the use of standardised patients. The goal of assessment in medical education remains the development of reliable measurements of student performance which, as well as having predictive value for subsequent clinical competence, also have a formative, educational role.
2855. Reliable assessment of the effects of treatment on mortality and major morbidity, II: observational studies.
Observational studies and randomised trials can contribute complementary evidence about the effects of treatment on mortality and on major non-fatal outcomes. In particular, observational studies have an important role in the identification of large adverse effects of treatment on infrequent outcomes (ie, rare, but serious, side-effects) that are not likely to be related to the indications for (or contraindications to) the treatment of interest. Such studies can also provide useful information about the risks of death and disability in particular circumstances that can help to generalise from clinical trials to clinical practice. But, due to their inherent potential for moderate or large biases, observational studies have little role in the direct assessment of any moderate effects of treatment on major outcomes that might exist. Instead, sufficiently large-scale evidence from randomised trials is needed to assess such treatment effects appropriately reliably. Wider appreciation of the different strengths and weaknesses of these two types of epidemiological study should increase the likelihood that the most reliable evidence available informs decisions about the treatments doctors use--and patients receive--for the management of a wide range of life-threatening conditions.
2856. Cushing's syndrome.
During the past 30 years, there have been advances in understanding of the pathogenesis of Cushing's syndrome and in differential diagnosis of its various forms. Improved diagnostic tests and procedures have increased the ability to recognise even mild hypercortisolism and have provided the means to obtain an accurate diagnosis. Despite these advances, the occurrence of unusual clinical presentations and laboratory shortcomings may produce diagnostic problems and challenge clinical intuition. This article reviews recent pathogenic views, new tests, and new diagnostic problems in the evaluation of Cushing's syndrome. Atypical clinical presentations of hypercortisolism and some laboratory shortcomings that may confuse the diagnosis of Cushing's syndrome are also reported.
2857. Influence of context effects on health outcomes: a systematic review.
Throughout history, doctor-patient relationships have been acknowledged as having an important therapeutic effect, irrespective of any prescribed drug or treatment. We did a systematic review to determine whether there was any empirical evidence to support this theory.
2858. Inflammation and cancer: back to Virchow?
The response of the body to a cancer is not a unique mechanism but has many parallels with inflammation and wound healing. This article reviews the links between cancer and inflammation and discusses the implications of these links for cancer prevention and treatment. We suggest that the inflammatory cells and cytokines found in tumours are more likely to contribute to tumour growth, progression, and immunosuppression than they are to mount an effective host antitumour response. Moreover cancer susceptibility and severity may be associated with functional polymorphisms of inflammatory cytokine genes, and deletion or inhibition of inflammatory cytokines inhibits development of experimental cancer. If genetic damage is the "match that lights the fire" of cancer, some types of inflammation may provide the "fuel that feeds the flames". Over the past ten years information about the cytokine and chemokine network has led to development of a range of cytokine/chemokine antagonists targeted at inflammatory and allergic diseases. The first of these to enter the clinic, tumour necrosis factor antagonists, have shown encouraging efficacy. In this article we have provided a rationale for the use of cytokine and chemokine blockade, and further investigation of non-steroidal anti-inflammatory drugs, in the chemoprevention and treatment of malignant diseases.
2859. Uterine fibroids.
Uterine leiomyomas (fibroids or myomas), benign tumours of the human uterus, are the single most common indication for hysterectomy. They are clinically apparent in up to 25% of women and cause significant morbidity, including prolonged or heavy menstrual bleeding, pelvic pressure or pain, and, in rare cases, reproductive dysfunction. Thus, both the economic cost and the effect on quality of life are substantial. Surgery has been the mainstay of fibroid treatment, and various minimally invasive procedures have been developed in addition to hysterectomy and abdominal myomectomy. Formation of new leiomyomas after these conservative therapies remains a substantial problem. Although medications that manipulate concentrations of steroid hormones are effective, side-effects limit long-term use. A better approach may be manipulation of the steroid-hormone environment with specific hormone antagonists. There has been little evidence-based evaluation of therapy. New research into the basic biology of these neoplasms may add new treatment options for the future as the role of growth factors and genetic mutations in these tumours are better understood.
2860. Neuropsychological effects of epilepsy and antiepileptic drugs.
Epilepsy and its treatment can have deleterious cognitive and behavioural consequences. Affected individuals have a higher prevalence of neuropsychological dysfunction than the general population because of complex interactions among several multifaceted and overlapping influences--for example, underlying neuropathologies, ictal and interictal neuronal discharges, a plethora of antiepileptic drugs, and numerous psychosocial issues. Research into the clinical relevance of these factors has been dogged by a range of methodological pitfalls including lack of standardisation of neuropsychological tests, small numbers and multiple testing, and statistical failure to appreciate differential effects of interactive elements in individual patients. Although antiepileptic drugs can impair neuropsychological functioning, their positive effect on seizure control might improve cognition and behaviour. Each person should be assessed individually with respect to factors unique to his or her seizure disorder and its treatment.
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