No abstract

Objective: Despite evidence demonstrating that riskfactor management is effective in reducing recurrent cerebrovascular disease, there are very few structured care programmes for stroke survivors. The aim was to implement and evaluate an integrated care programme in stroke. Methods: 186 patients with stroke were randomised to either the treatment (integrated care) or control (usual care) group and were followed up over 12 months. The Integrated Care for the Reduction of Secondary Stroke (ICARUSS) model of integrated care involved collaboration between a specialist stroke service, a hospital coordinator and a patient's general practitioner. The primary aim was to promote the management of vascular risk factors through ongoing patient contact and education. Results: In the 12 months poststroke, systolic blood pressure (sBP) decreased in the treatment group but increased in controls. The group difference was significant, and remained so when age, sex, disability and sBP at discharge were accounted for (p = 0.04). Treatment patients also exhibited better modification of body mass index (p = 0.007) and number of walks taken (p,0.001) than controls. Rankin scores indicated significantly reduced disability in treatment patients relative to controls in the year poststroke (p = 0.003). Conclusions: Through an integrated system of education, advice and support to both patient and GP, the ICARUSS model was effective in modifying a variety of vascular risk factors and therefore should decrease the likelihood or recurrent stroke or vascular event.Stroke recurrence is a consistent and independent predictor of disability, institutionalisation and death, often resulting in a stepwise decline into dependency in stroke survivors.1 The burden of stroke is expected to increase in future years with the rapid rise in older people and the decline in stroke mortality.2 Secondary prevention of stroke, therefore, is of paramount importance. It has been estimated that the successful management of recognised vascular risk factors can reduce stroke incidence by 70-80%. [3][4][5]

The mechanisms for the association of old age with post-prandial hyperlipidemia and atherosclerosis are not well understood. Post-prandial hyperlipidemia has emerged as a significant risk for atherosclerosis. The liver is the central organ for lipoprotein metabolism. The initial step in the hepatic uptake of post-prandial lipoproteins is their transfer from the hepatic sinusoidal capillary lumen across the hepatic sinusoidal endothelium into the space of Disse. Here, they access hepatocytes for receptor-mediated uptake. We proposed that fenestrations (pores) within the hepatic sinusoidal endothelium filter lipoproteins on the basis of size. Recently we discovered age-related changes in the sinusoidal endothelium (pseudocapillarization), including reduction in the porosity of the endothelium. Using the impulse response technique in perfused rat livers, we found that aging is associated with impaired hepatic transendothelial transfer of chylomicrons with diameters smaller than those of fenestrations. In conclusion, age-related pseudocapillarization of the hepatic sinusoidal endothelium provides a novel mechanism for the association of old age with impaired hepatic lipoprotein metabolism and with atherosclerosis.

Age-related changes in liver function are important because they may promote susceptibility to adverse drug reactions, neurotoxicity, atherosclerosis, and other important diseases in older people. Age-related changes in the rat hepatic sinusoidal endothelium, termed pseudocapillarization, have been described recently and these may contribute to hepatic impairment. The present study has examined surgical and post-mortem specimens with immunohistochemistry and transmission electron microscopy to determine whether pseudocapillarization also occurs in older humans. The age of the subject, independent of systemic disease or hepatic pathology in surgical and post-mortem samples of human liver, was associated with increased peri-sinusoidal expression of von Willebrand's factor, collagen I, collagen IV, and staining with Masson's trichrome. Electron microscopy revealed significant age-related thickening of the sinusoidal endothelium (young 165 +/- 17 nm, middle age 222 +/- 11 nm, older 289 +/- 9 nm, p < 0.001) with loss of fenestrations (young 7.7 +/- 0.7 per 10 micro m, middle age 3.6 +/- 0.5 per 10 micro m, older 1.5 +/- 0.4 per 10 micro m, p < 0.001), and age-related deposition of basal lamina and collagen. In conclusion, ageing in humans is associated with morphological changes in the sinusoidal endothelium and space of Disse which are presumptively related to the ageing process and potentially represent an important link between the ageing process and disease susceptibility.

No abstract

No abstract

The effects of liver disease on pharmacokinetics and pharmacodynamics are highly variable, and difficult to predict as the mechanisms of these effects are not well understood. Since the majority of the published literature is concerned with cirrhotic liver disease, this review also focuses mainly on this area. Four different theories have been proposed to account for the effects of chronic liver disease with cirrhosis on hepatic drug elimination: the sick cell theory; the intact hepatocyte theory; the impaired drug uptake theory; and the oxygen limitation theory. While some data in support of each of the first 2 theories have been published recently, a large amount of clinical data would appear to refute both of these theories. These clinical data are substantially consistent with the latter 2 theories, which regard the decreased permeability of the capillarised sinusoid as the critical feature in cirrhosis. Further work is required to determine the applicability of each of these theories. In cirrhosis, drug glucuronidation is spared relative to oxidative drug metabolism; however, in advanced cirrhosis this pathway may also be impaired substantially. There is evidence that in cirrhosis other conjugation pathways may also be impaired to variable degrees. Growing evidence suggests that biliary drug excretion is impaired in cirrhosis. Recent studies with several racemic drugs indicate that the disease can have different effects on the hepatic elimination of individual enantiomers, which may lead to a change in the concentration-response relationships of racemic drugs in cirrhosis. A major finding which has emerged in recent years is that, even with moderate degrees of hepatic impairment, there is a decrease in clearance of drugs or active metabolites normally cleared by the kidney. The effect on renal clearance of unbound drug may be masked if there is a concomitant decrease in plasma protein binding of the drug. Neither serum creatinine levels nor creatinine clearance are useful markers of the renal dysfunction associated with cirrhosis. Both may greatly overestimate renal function in patients with cirrhosis due to increased fractional renal tubular secretion of creatinine. Altered receptor sensitivity has been observed with some drugs in cirrhosis, while for other drugs there is no change in pharmacodynamics. Precise determination of drug dosage in cirrhosis requires information on changes in pharmacodynamics and plasma protein binding in addition to changes in drug elimination. Pharmacokinetic investigations in a variety of chronic liver diseases without cirrhosis (e.g. carcinoma, schistosomiasis and viral hepatitis) suggest that in the absence of cirrhosis, impairment of drug elimination is not sufficient to warrant reduction of drug dosage. However, if cirrhosis is present, 'safe' drug use requires an awareness of the possibility of multiple interactions between changes in hepatic and renal disposition and pharmacodynamics. In chronic liver disease with cirrhosis, dosage reduction is the general rule regardless...

Abstract-The management of stroke in rural and regional areas is variable in both the developed and developing world.Informed by best-practice guidelines and recommendations for systems of stroke care, adaptable models of care that are appropriate for local needs should be devised for rural and regional settings. This review addresses the issue of the provision of appropriate services in rural and regional settings, with particular attention to the barriers involved, according to the classification of Low Human Development Country (LHDC), Medium Human Development Country (MHDC) and High Human Development Country (HHDC). We discuss the need and feasibility of developing implementing stroke care in rural settings according to best-practice recommendations, within models of care adapted to local conditions.