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2341. Are the clinical effects of homoeopathy placebo effects? Comparative study of placebo-controlled trials of homoeopathy and allopathy.

作者: Aijing Shang.;Karin Huwiler-Müntener.;Linda Nartey.;Peter Jüni.;Stephan Dörig.;Jonathan A C Sterne.;Daniel Pewsner.;Matthias Egger.
来源: Lancet. 2005年366卷9487期726-32页
Homoeopathy is widely used, but specific effects of homoeopathic remedies seem implausible. Bias in the conduct and reporting of trials is a possible explanation for positive findings of trials of both homoeopathy and conventional medicine. We analysed trials of homoeopathy and conventional medicine and estimated treatment effects in trials least likely to be affected by bias.

2342. Phaeochromocytoma.

作者: Jacques W M Lenders.;Graeme Eisenhofer.;Massimo Mannelli.;Karel Pacak.
来源: Lancet. 2005年366卷9486期665-75页
Phaeochromocytomas are rare neuroendocrine tumours with a highly variable clinical presentation but most commonly presenting with episodes of headaches, sweating, palpitations, and hypertension. The serious and potentially lethal cardiovascular complications of these tumours are due to the potent effects of secreted catecholamines. Biochemical testing for phaeochromocytoma is indicated not only in symptomatic patients, but also in patients with adrenal incidentalomas or identified genetic predispositions (eg, multiple endocrine neoplasia type 2, von Hippel-Lindau syndrome, neurofibromatosis type 1, and mutations of the succinate dehydrogenase genes). Imaging techniques such as CT or MRI and functional ligands such as (123)I-MIBG are used to localise biochemically proven tumours. After the use of appropriate preoperative treatment to block the effects of secreted catecholamines, laparoscopic tumour removal is the preferred procedure. If removal of phaeochromocytoma is timely, prognosis is excellent. However, prognosis is poor in patients with metastases, which especially occur in patients with large, extra-adrenal tumours.

2343. NAT2 slow acetylation, GSTM1 null genotype, and risk of bladder cancer: results from the Spanish Bladder Cancer Study and meta-analyses.

作者: Montserrat García-Closas.;Núria Malats.;Debra Silverman.;Mustafa Dosemeci.;Manolis Kogevinas.;David W Hein.;Adonina Tardón.;Consol Serra.;Alfredo Carrato.;Reina García-Closas.;Josep Lloreta.;Gemma Castaño-Vinyals.;Meredith Yeager.;Robert Welch.;Stephen Chanock.;Nilanjan Chatterjee.;Sholom Wacholder.;Claudine Samanic.;Montserrat Torà.;Francisco Fernández.;Francisco X Real.;Nathaniel Rothman.
来源: Lancet. 2005年366卷9486期649-59页
Many reported associations between common genetic polymorphisms and complex diseases have not been confirmed in subsequent studies. An exception could be the association between NAT2 slow acetylation, GSTM1 null genotype, and bladder-cancer risk. However, current evidence is based on meta-analyses of relatively small studies (range 23-374 cases) with some evidence of publication bias and study heterogeneity. Associations between polymorphisms in other NAT and GST genes and bladder-cancer risk have been inconsistent.

2344. Stem cells.

作者: A Vats.;R C Bielby.;N S Tolley.;R Nerem.;J M Polak.
来源: Lancet. 2005年366卷9485期592-602页
Stem cells derived from adult and embryonic sources have great therapeutic potential, but much research is still needed before their clinical use becomes commonplace. There is debate about whether adult stem cells can be used instead of those derived from embryos. Rationalisation is needed but can be exercised only once the various cells have been carefully compared and contrasted under appropriate experimental conditions. Some characteristics that might help resolve the issue of cell source can already be applied to the debate. Accessibility is important; some adult cells, such as neural stem cells, are difficult to obtain, at least from living donors. Other factors include the frequency and abundance of adult stem cells and their numbers and potency, which might decline with age or be affected by disease. For embryonic stem cells, ethical concerns have been raised, and the proposed practice of therapeutic cloning tends to be misrepresented in the lay media. For both adult and embryonic stem cells, stability, potential to transmit harmful pathogens or genetic mutations, and risk of forming unwanted tissues or even teratocarcinomas have yet to be fully assessed.

2345. Ectopic pregnancy.

作者: Cynthia M Farquhar.
来源: Lancet. 2005年366卷9485期583-91页
Ectopic pregnancy is an important cause of morbidity and mortality worldwide. Use of transvaginal ultrasonography and quantitative measurement of the beta subunit of human chorionic gonadotropin (beta-hCG) has led to a reduction in the need for diagnostic laparoscopy. Furthermore, with earlier diagnosis, medical therapy with methotrexate can be offered and surgery avoided in some women, though the best regimen remains unclear. In the surgical management of ectopic pregnancy, the benefits of salpingectomy over salpingostomy are uncertain. Although there have been advances in the management of ectopic pregnancy there are still questions to be answered.

2346. Endometrial cancer.

作者: Frederic Amant.;Philippe Moerman.;Patrick Neven.;Dirk Timmerman.;Erik Van Limbergen.;Ignace Vergote.
来源: Lancet. 2005年366卷9484期491-505页
Each year, endometrial cancer develops in about 142,000 women worldwide, and an estimated 42,000 women die from this cancer. The typical age-incidence curve for endometrial cancer shows that most cases are diagnosed after the menopause, with the highest incidence around the seventh decade of life. The appearance of symptoms early in the course explains why most women with endometrial cancer have early-stage disease at presentation. For all stages taken together, the overall 5-year survival is around 80%. There is a substantial prognostic difference between the histological types of endometrial cancers. The most common lesions (type 1) are typically hormone sensitive and low stage and have an excellent prognosis, whereas tumours of type 2 are high grade with a tendency to recur, even in early stage. The cornerstone of treatment for endometrial cancer is surgery, which not only is important for staging purposes but also enables appropriate tailoring of adjuvant treatment modalities that benefit high-risk patients only. We review current concepts about epidemiology, pathology, pathogenesis, risk factors and prevention, diagnosis, staging, prognostic factors, treatment, and follow-up of endometrial cancer.

2347. Treatment of menopausal symptoms: what shall we do now?

作者: Martha Hickey.;Susan R Davis.;David W Sturdee.
来源: Lancet. 2005年366卷9483期409-21页
During the past few years, many women and doctors have revised their opinions of hormone replacement therapy (HRT) for menopausal symptoms, and a substantial number of individuals have discontinued its use because of concerns about side-effects. Numerous alternatives to HRT are promoted, and assessment of the quality of evidence about the safety and effectiveness of these compounds can be difficult. In this Review, we summarise the data from studies addressing the efficacy, risks, and benefits of frequently prescribed treatments, and offer evidence-based clinical guidelines for the management of menopausal symptoms. Although few comparative studies exist, oestrogen alone or combinations of oestrogen and progestagen are likely to be the most effective treatments for menopausal hot flushes and vaginal dryness. Tibolone is as effective as HRT, however, and might also improve libido. For those who wish to avoid hormonal treatments, there are few effective options. Selective serotonin reuptake inhibitors might be effective in the very short term (less than 12 weeks) and are well tolerated. There is not enough evidence that any of the complementary therapies available are any better than placebo for menopausal vasomotor symptoms, and few safety data exist.

2348. Malignant mesothelioma.

作者: Bruce W S Robinson.;Arthur W Musk.;Richard A Lake.
来源: Lancet. 2005年366卷9483期397-408页
Malignant mesothelioma is an aggressive, treatment-resistant tumour, which is increasing in frequency throughout the world. Although the main risk factor is asbestos exposure, a virus, simian virus 40 (SV40), could have a role. Mesothelioma has an unusual molecular pathology with loss of tumour suppressor genes being the predominant pattern of lesions, especially the P16INK4A, and P14ARF, and NF2 genes, rather than the more common p53 and Rb tumour suppressor genes. Cytopathology of mesothelioma effusions or fine-needle aspirations are often sufficient to establish a diagnosis, but histopathology is also often required. Patients typically present with breathlessness and chest pain with pleural effusions. Median survival is now 12 months from diagnosis. Palliative chemotherapy is beneficial for mesothelioma patients with high performance status. The role of aggressive surgery remains controversial and growth factor receptor blockade is still unproven. Gene therapy and immunotherapy are used on an experimental basis only. Patterns identified from microarray studies could be useful for diagnosis as well as prognostication.

2349. Sjögren's syndrome.

作者: Robert I Fox.
来源: Lancet. 2005年366卷9482期321-31页
Sjögren's syndrome is a chronic autoimmune disorder of the exocrine glands with associated lymphocytic infiltrates of the affected glands. Dryness of the mouth and eyes results from involvement of the salivary and lacrimal glands. The accessibility of these glands to biopsy enables study of the molecular biology of a tissue-specific autoimmune process. The exocrinopathy can be encountered alone (primary Sjögren's syndrome) or in the presence of another autoimmune disorder such as rheumatoid arthritis, systemic lupus erythematosus, or progressive systemic sclerosis. A new international consensus for diagnosis requires objective signs and symptoms of dryness including a characteristic appearance of a biopsy sample from a minor salivary gland or autoantibody such as anti-SS-A. Exclusions to the diagnosis include infections with HIV, human T-lymphotropic virus type I, or hepatitis C virus. Therapy includes topical agents to improve moisture and decrease inflammation. Systemic therapy includes steroidal and non-steroidal anti-inflammatory agents, disease-modifying agents, and cytotoxic agents to address the extraglandular manifestations involving skin, lung, heart, kidneys, and nervous system (peripheral and central) and haematological and lymphoproliferative disorders. The most difficult challenge in diagnosis and therapy is patients with symptoms of fibromyalgia (arthralgia, myalgia, fatigue) and oral and ocular dryness in the presence of circulating antinuclear antibodies.

2350. Stem cells of the alveolar epithelium.

作者: Mark J D Griffiths.;Dominique Bonnet.;Sam M Janes.
来源: Lancet. 2005年366卷9481期249-60页
Elucidation of the biology of stem cells of the lung parenchyma could revolutionise treatment of patients with lung disorders such as cancer, acute respiratory distress syndrome, emphysema, and fibrotic lung disease. How close is this goal? Despite remarkable observations and ensuing advances, more questions than answers have been generated. Progenitors of the alveolar epithelium remain largely mysterious, so the prospect of isolating enough of these cells and delivering them effectively to cure disease remains remote. Similarly, the bone-marrow-derived cell that might most effectively engraft the lung remains unknown. If this mechanism is an important process for lung repair, why will the administration of additional cells be more effective? Finally, there is an issue of control of multipotent cells to avoid the generation of multiple teratomas, longevity of the graft, and possible immunological reactions to gene products inserted to replace a deficiency. The biology is exciting but not yet well enough understood to support therapeutic advances.

2351. Attention-deficit hyperactivity disorder.

作者: Joseph Biederman.;Stephen V Faraone.
来源: Lancet. 2005年366卷9481期237-48页
Attention-deficit hyperactivity disorder (ADHD) is a disorder of inattention, impulsivity, and hyperactivity that affects 8-12% of children worldwide. Although the rate of ADHD falls with age, at least half of children with the disorder will have impairing symptoms in adulthood. Twin, adoption, and molecular genetic studies show ADHD to be highly heritable, and other findings have recorded obstetric complications and psychosocial adversity as predisposing risk factors. Converging evidence from animal and human studies implicates the dysregulation of frontal-subcortical-cerebellar catecholaminergic circuits in the pathophysiology of ADHD, and molecular imaging studies suggest that abnormalities of the dopamine transporter lead to impaired neurotransmission. Studies during the past decade have shown the safety and effectiveness of new non-stimulant drugs and long-acting formulations of methylphenidate and amfetamine. Other investigations have also clarified the appropriate role of targeted psychosocial treatments in the context of ongoing pharmacotherapy.

2352. Acute rheumatic fever.

作者: Jonathan R Carapetis.;Malcolm McDonald.;Nigel J Wilson.
来源: Lancet. 2005年366卷9480期155-68页
Acute rheumatic fever (ARF) and its chronic sequela, rheumatic heart disease (RHD), have become rare in most affluent populations, but remain unchecked in developing countries and in some poor, mainly indigenous populations in wealthy countries. More than a century of research, mainly in North America and Europe, has improved our understanding of ARF and RHD. However, whether traditional views need to be updated in view of the epidemiological shift of the past 50 years is still to be established, and improved data from developing countries are needed. Doctors who work in populations with a high incidence of ARF are adapting existing diagnostic guidelines to increase their sensitivity. Group A streptococcal vaccines are still years away from being available and, even if the obstacles of serotype coverage and safety can be overcome, their cost could make them inaccessible to the populations that need them most. New approaches to primary prevention are needed given the limitations of primary prophylaxis as a population-based strategy. The most effective approach for control of ARF and RHD is secondary prophylaxis, which is best delivered as part of a coordinated control programme.

2353. Role of leptin in energy-deprivation states: normal human physiology and clinical implications for hypothalamic amenorrhoea and anorexia nervosa.

作者: Jean L Chan.;Christos S Mantzoros.
来源: Lancet. 2005年366卷9479期74-85页
Leptin is an adipocyte-secreted hormone that plays a key part in energy homoeostasis. Advances in leptin physiology have established that the main role of this hormone is to signal energy availability in energy-deficient states. Studies in animals and human beings have shown that low concentrations of leptin are fully or partly responsible for starvation-induced changes in neuroendocrine axes, including low reproductive, thyroid, and insulin-like growth factor (IGF) hormones. Disease states such as exercise-induced hypothalamic amenorrhoea and anorexia nervosa are also associated with low concentrations of leptin and a similar spectrum of neuroendocrine abnormalities. We have recently shown in an interventional, proof-of-concept study that leptin can restore ovulatory menstrual cycles and improve reproductive, thyroid, and IGF hormones and bone markers in hypothalamic amenorrhoea. Further studies are warranted to establish the safety and effectiveness of leptin for the infertility and osteoporosis associated with hypothalamic amenorrhoea, and to clarify its role in anorexia nervosa.

2354. Pemphigus.

作者: Jean-Claude Bystryn.;Jennifer L Rudolph.
来源: Lancet. 2005年366卷9479期61-73页
Pemphigus is a rare autoimmune disease that results in blistering of the skin and oral cavity. It is caused by autoantibodies directed against cell-surface antigens on keratinocytes, which when targeted lose their cellular adhesion properties and separate from one another to form blisters within the epidermis. Differences in the particular antigens targeted by the antibodies and in the distribution of these antigens in the different regions of the body and in the separate layers of the epidermis result in different clinical manifestations of the disease. The disease is diagnosed based on its clinical manifestations (flaccid blisters and erosions on skin and oral mucosa), histology (epidermal acantholysis), and immunological abnormalities (circulating and tissue-fixed antibodies against keratinocyte surface antigens). Pemphigus, which if left untreated is almost always fatal, is generally managed with topical, oral, or intralesional corticosteroids. Other options include plasmapheresis and intravenous immunoglobulin (IVIg), coupled with cytotoxic drugs. Immunosupressants, anti-inflammatory drugs, and antibiotics are used as adjuvants, but apart from IVIg, these therapy options are non-specific and more research is needed to develop treatments with improved side-effect profiles.

2355. Calcimimetics and calcilytics--fooling the calcium receptor.

作者: Simon J Steddon.;John Cunningham.
来源: Lancet. 2005年365卷9478期2237-9页
Just a decade after the the calcium-sensing receptor (CaR) was identified, pharmacological manipulation of the CaR is about to enter routine practice. For hyperparathyroid states, calcimimetics, which increase activation of the CaR, have been licensed in Europe and the USA. Calcilytics, which decrease CaR function and increase secretion of parathyroid hormone (PTH), might allow the anabolic effects of PTH on bone to be harnessed for the prevention and treatment of osteoporosis.

2356. Alpha1-antitrypsin deficiency.

作者: James K Stoller.;Loutfi S Aboussouan.
来源: Lancet. 2005年365卷9478期2225-36页
Alpha1-antitrypsin deficiency is a genetic disorder that affects about one in 2000-5000 individuals. It is clinically characterised by liver disease and early-onset emphysema. Although alpha1 antitrypsin is mainly produced in the liver, its main function is to protect the lung against proteolytic damage from neutrophil elastase. The most frequent mutation that causes severe alpha1-antitrypsin deficiency arises in the SERPINA 1 gene and gives rise to the Z allele. This mutation reduces concentrations in serum of alpha1 antitrypsin by retaining polymerised molecules within hepatocytes: an amount below the serum protective threshold of 11 micromol/L increases risk for emphysema. In addition to the usual treatments for emphysema, infusion of purified alpha1 antitrypsin from pooled human plasma represents a specific treatment and raises the concentrations in serum and epithelial-lining fluid above the protective threshold. Evidence suggests that this approach is safe, slows the decline of lung function, could reduce infection rates, and might enhance survival. However, uncertainty about the cost-effectiveness of this expensive treatment remains.

2357. Recognition and management of complications of new recreational drug use.

作者: George A Ricaurte.;Una D McCann.
来源: Lancet. 2005年365卷9477期2137-45页
Use of illicit drugs in clubs and large dance parties (so-called raves) is a burgeoning cultural trend. Such recreational drug use is associated with several medical complications, both acute and longlasting. Although few, if any, of the drugs currently used in recreational venues are truly new, their patterns and context of use have changed (a great deal in some instances). For some of these substances, this cultural repackaging of the drug experience has resulted in various medical disorders that have previously gone undocumented. This review aims to help treating physicians recognise and manage complications associated with the use of new drugs in clubs, including methylenedioxymethamfetamine, ephedrine, gamma-hydroxybutyrate; gamma-butyrolactone, 1,4-butanediol, flunitrazepam, ketamine, and nitrites. We also alert researchers to specific toxic effects of club-drugs on which more basic information is needed.

2358. Congenital adrenal hyperplasia.

作者: Deborah P Merke.;Stefan R Bornstein.
来源: Lancet. 2005年365卷9477期2125-36页
Congenital adrenal hyperplasia (CAH) due to deficiency of 21-hydroxylase is a disorder of the adrenal cortex characterised by cortisol deficiency, with or without aldosterone deficiency, and androgen excess. Patients with the most severe form also have abnormalities of the adrenal medulla and epinephrine deficiency. The severe classic form occurs in one in 15,000 births worldwide, and the mild non-classic form is a common cause of hyperandrogenism. Neonatal screening for CAH and gene-specific prenatal diagnosis are now possible. Standard hormone replacement fails to achieve normal growth and development for many children with CAH, and adults can experience iatrogenic Cushing's syndrome, hyperandrogenism, infertility, or the development of the metabolic syndrome. This Seminar reviews the epidemiology, genetics, pathophysiology, diagnosis, and management of CAH, and provides an overview of clinical challenges and future therapies.

2359. Antiviral medications to prevent cytomegalovirus disease and early death in recipients of solid-organ transplants: a systematic review of randomised controlled trials.

作者: Elisabeth M Hodson.;Cheryl A Jones.;Angela C Webster.;Giovanni F M Strippoli.;Peter G Barclay.;Kathy Kable.;Dushyanthi Vimalachandra.;Jonathan C Craig.
来源: Lancet. 2005年365卷9477期2105-15页
Antiviral prophylaxis is commonly used in recipients of solid-organ transplants with the aim of preventing the clinical syndrome associated with cytomegalovirus infection. We undertook a systematic review to investigate whether this approach affects risks of cytomegalovirus disease and death.

2360. Nasopharyngeal carcinoma.

作者: William I Wei.;Jonathan S T Sham.
来源: Lancet. 2005年365卷9476期2041-54页
Incidence of nasopharyngeal carcinoma has remained high in endemic regions. Diagnosing the disease in the early stages requires a high index of clinical acumen and, although most cross-sectional imaging investigations show the tumour with precision, confirmation is dependent on histology. Epstein-Barr virus (EBV)-encoded RNA signal is present in all nasopharyngeal carcinoma cells, and early diagnosis of the disease is possible through the detection of raised antibodies against EBV. The quantity of EBV DNA detected in blood indicates the stage and prognosis of the disease. Radiotherapy with concomitant chemotherapy has increased survival, and improved techniques (such as intensity-modulated radiotherapy), early detection of recurrence, and application of appropriate surgical salvage procedures have contributed to improved therapeutic results. Screening of high-risk individuals in endemic regions together with developments in gene therapy and immunotherapy might further improve outcome.
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