3022. Heparin, cell adhesion, and pathogenesis of inflammatory bowel disease.
Tissue repair involves a close interplay between growth factors and cell adhesion molecules. The normal healing process may be disrupted by pathophysiological states such as inflammation, due to loss of growth factors, cell adhesion molecules, or both, which results in a reduced rate of healing. Such events may occur in inflammatory bowel disease during mucosal restitution. We postulate that the beneficial response to heparin observed in inflammatory bowel disease may result from mechanisms in addition to anticoagulation. These include the restoration of high-affinity receptor binding by antiulcerogenic growth factors, such as basic fibroblast growth factor, that normally rely on the presence of heparan sulphate proteoglycans, such as syndecan-1, as co-receptors. Loss of syndecan-1 has been observed in the ulcerated mucosa of patients with inflammatory bowel disease. This loss may lead to impaired binding of basic fibroblast growth factor and a reduced rate of ulcer healing. We suggest that heparin restores high-affinity receptor binding of basic fibroblast growth, and so increases the rate of mucosal recovery.
3024. Suffering: the contributions of persistent pain.
Pain is a perceived threat or damage to one's biological integrity. Suffering is the perception of serious threat or damage to the self, and it emerges when a discrepancy develops between what one expected of one's self and what one does or is. Some patients who experience sustained unrelieved pain suffer because pain changes who they are. At a physiological level, chronic pain promotes an extended and destructive stress response characterised by neuroendocrine dysregulation, fatigue, dysphoria, myalgia, and impaired mental and physical performance. This constellation of discomforts and functional limitations can foster negative thinking and create a vicious cycle of stress and disability. The idea that one's pain is uncontrollable in itself leads to stress. Patients suffer when this cycle renders them incapable of sustaining productive work, a normal family life, and supportive social interactions. Although patients suffer for many reasons, the physician can contribute substantially to the prevention or relief of suffering by controlling pain. Suffering is a nebulous concept for most physicians, and its relation to pain is unclear. This review offers a medically useful concept of suffering that distinguishes it from pain, accounts for the contributory relation of pain to suffering by describing pain as a stressor, and explores the implications of these ideas for the care of patients.
3025. Opioids in pain management.
Opioids are our most powerful analgesics, but politics, prejudice, and our continuing ignorance still impede optimum prescribing. Just over 100 years ago, opium poppies were still grown on the Cambridgeshire fens in the UK to provide oblivion for the working man and his family, but the brewing lobby argued on thin evidence that their potions were less dangerous. The restriction of opioid availability to protect society and the individual continues in many countries. In this review I focus on chronic and cancer pain, but many of the principles apply in acute pain. The justification for this focus is that patients with chronic pain may suffer longer and unnecessarily if we prescribe and legislate badly.
3026. Visceral pain.
Visceral pain is the most common form of pain produced by disease and one of the most frequent reasons why patients seek medical attention. Yet much of what we know about the mechanisms of pain derives from experimental studies of somatic not visceral nociception. The conventional view is that visceral pain is simply a variant of somatic pain, a view based on the belief that a single neurological mechanism is responsible for all pain. However, the more we learn about the mechanisms of somatic and visceral pain, the more we realise that although these two processes have much in common, they also have important differences. Although visceral pain is an important part of the normal sensory repertoire of all human beings and a prominent symptom of many clinical conditions, not much clinical research has been done in this field and there are few clinical scientists with expertise in the management of visceral pain. Instead, visceral pain is usually treated by a range of specialists who take quite different approaches to the management of this type of pain. Thus, the management of visceral pain is frequently unsatisfactory. In this review, we consider visceral pain as a separate form of pain and examine its distinct sensory properties from a clinical perspective. We describe recent research findings that may change the way we think about visceral pain and, more importantly, may help develop new procedures for its management.
3027. Acute pain.
Postanaesthesia care units used to echo with cries of patients in pain after general anaesthesia. Each as-needed dose of analgesia was given only after permission of the surgeon or anaesthesiologist. Once conscious, patients were required to request each subsequent analgesic dose until hospital discharge. Not surprisingly, nearly half the patients who have an operation experience moderate to severe pain after surgery. Acute pain control has advanced dramatically and is now a field with dedicated texts, journals, and research. Despite improved surgical techniques that have transformed many operations into same-day procedures, inadequately controlled pain may still extend the length of hospital stay and predispose to expensive, time-consuming complications such as pneumonia. Recognition of economic and humanitarian benefits of pain control has prompted worldwide attention from professional groups, insurers, and governments. This paper describes the process of acute pain and measures to control it with drugs or non-pharmacological interventions. Even brief intervals of acute pain can induce long-term neuronal remodelling and sensitisation ("plasticity"), chronic pain, and lasting psychologial distress. Hence, acute pain and other types of pain (cancer-related or chronic) that are classified as distinct actually have many similarities.
3028. Zidovudine, didanosine, and zalcitabine in the treatment of HIV infection: meta-analyses of the randomised evidence. HIV Trialists' Collaborative Group.
来源: Lancet. 1999年353卷9169期2014-25页
To assess the effects of zidovudine, didanosine, and zalcitabine on HIV disease progression and survival, we undertook meta-analyses of individual patient data and tabular data from all randomised trials that compared these agents.
3034. Neuropathic pain: aetiology, symptoms, mechanisms, and management.
We highlight current theories about peripheral neuropathic pain and show that progress in management is contingent on targeting treatment not at the aetiological factors or the symptoms but at the mechanisms that operate to produce the symptoms. This approach will require substantial progress in our understanding of the pathophysiology of neuropathic pain, the development of accurate diagnostic tools to discover what mechanisms contribute to the pain syndrome in an individual, and effective treatments aimed specifically at the mechanisms.
3035. Human T-lymphotropic virus type I infection.
Human T-cell lymphotropic virus type I (HTLV-I) is the first human retrovirus to be associated with malignant disease--namely, adult T-cell leukaemia/lymphoma. HTLV-I has also been associated with several non-malignant conditions, notably the chronic neurodegenerative disorder, HTLV-I associated myelopathy (also known as tropical spastic paraparesis), infective dermatitis of children and uveitis. More recent evidence points to disease associations not previously linked to HTLV-I. Thus, the disease spectrum of HTLV-I is not fully known. HTLV-I has a worldwide distribution with major endemic foci in the Caribbean and southern Japan. The public health importance is confirmed by the major routes of transmission, which are mother-to-child, blood transfusion, and sexual activity. Unfortunately, no vaccine is available yet and there is no proven treatment for advanced HTLV-I disease.
3036. Management of chronic pain.
Chronic pain is a common condition for which patients seek care from various health-care providers. This type of pain causes much suffering and disability and is frequently mistreated or undertreated. Patients who present for evaluation for chronic pain should undergo a careful assessment before therapy. Patients with chronic pain commonly experience depression, sleep disturbance, fatigue, and decreased overall physical and mental functioning. They frequently require an interdisciplinary model of care to allow care givers to address the multiple components of the patient's pain experience. After a careful evaluation, therapy may include medication, nerve blocks, active physical therapy, behavioural interventions, and assistance with vocational evaluation and training. Less frequently therapy may include placement of implantable devices to alter the pain experience. These patients suffer from a chronic condition and often require long-term care, with frequent reassessment and adjustment of therapy. Although cure is possible, it is also infrequent. Therefore, therapy is provided with the aim of decreasing pain and suffering while improving physical and mental functioning.
3037. The fetal insulin hypothesis: an alternative explanation of the association of low birthweight with diabetes and vascular disease.
Low birthweight is associated with insulin resistance, hypertension, coronary-artery disease, and non-insulin-dependent diabetes (NIDDM). A suggested explanation for this association is intrauterine programming in response to maternal malnutrition. We propose, however, that genetically determined insulin resistance results in impaired insulin-mediated growth in the fetus as well as insulin resistance in adult life. Low birthweight, measures of insulin resistance in life, and ultimately glucose intolerance, diabetes, and hypertension could all be phenotypes of the same insulin-resistant genotype. There is evidence to support this hypothesis. Insulin secreted by the fetal pancreas in response to maternal glucose concentrations is a key growth factor. Monogenic diseases that impair sensing of glucose, lower insulin secretion, or increase insulin resistance are associated with impaired fetal growth. Polygenic influences resulting in insulin resistance in the normal population are therefore likely to result in lower birthweight. Abnormal vascular development during fetal life and early childhood, as a result of genetic insulin resistance, could also explain the increased risk of hypertension and vascular disease. The predisposition to NIDDM and vascular disease is likely to be the result of both genetic and fetal environmental factors.
3038. Assessment of patients' reporting of pain: an integrated perspective.
A common assumption about pain is that it always results from the presence of underlying organic pathology. In the absence of objective pathology, an individual's report of pain may be ascribed to psychological causes. There is a wide variation in patient's experience of pain and organic factors alone cannot explain individual differences in patients' reports. Assessment of patients who report pain requires attention to psychosocial, behavioural, and organic factors. We describe a comprehensive approach to the assessment of psychological and behavioural variables that affect patients' reports of pain. We counter the duality of the somatogenic versus psychogenic perspective and suggest a more integrated assessment that encompasses not only the severity of pain and related physical pathology but also the person who is reporting the presence of pain.
3039. Lichen sclerosus.
Lichen sclerosis is a chronic inflammatory skin disease that causes substantial discomfort and morbidity, most commonly in adult women, but also in men and children. Any skin site may be affected (and, rarely, the oral mucosa) but lichen sclerosus is most common in the anogenital area, where it causes intractable itching and soreness. In children, the disorder may be confused with changes seen in sexual abuse. Progression to destructive scarring is common. There is increased risk of developing vulval cancer, and there are links with penile cancer. Patients should be kept under long-term review. Lichen sclerosus can occur without symptoms, and the exact prevalence is uncertain. It occurs most commonly in women at times of low sex hormone output. The underlying cause is unknown, but there seems to be a genetic susceptibility and a link with autoimmune mechanisms. The wart virus and the spirochaete borrelia have been suggested but not substantiated as infective triggers. The Koebner phenomenon is known to occur (lichen sclerosus occurs in skin already scarred or damaged), so trauma, injury, and sexual abuse have been suggested as possible triggers of symptoms in genetically predisposed people. The treatment of choice for anogenital lichen sclerosus is potent topical corticosteroid ointment for a limited time. Circumcision may be indicated in men, and surgery may be considered in women, to relieve effects of scarring or to treat coexisting carcinoma. Current research aims to identify a treatable cause of lichen sclerosus, to identify patients at risk of scarring and of malignant disorders, and to find target pathways for therapeutic intervention.
|