The Relevance of Academic Libraries in the Twenty-First Century

The biggest challenge facing the library profession in the twenty-first century is staying relevant to its users. It is often stated that the Internet and Google have changed librarianship. This challenge, while significant, does not mean that libraries will go away. It is causing us to re-evaluate what we do, how we do it, and what role libraries have in the academy and in our culture at large. This column addresses some of the ways in which academic libraries can stay relevant throughout the twenty-first century

Predictors of weight loss and reversal of comorbidities in malabsorptive bariatric surgery

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Insulin clearance in obesity

Insulin uptake and degradation is a complex and not yet completely understood process involving not only insulin sensitive tissues. The most important degradative system is insulin degrading enzyme which is a highly conserved metalloendopeptidase requiring Zn(++) for its proteolytic action, although protein disulfide isomerase and cathepsin D are also involved in insulin metabolism. The liver and the kidney are the principal sites for insulin clearance. In obese subjects with hyperinsulinemia and high levels of free fatty acids, insulin hepatic clearance is impaired, while the glomerular filtration rate, renal plasma flow and albumin excretion are increased, suggesting a state of renal vasodilatation leading to an abnormally transmitted arterial pressure to the glomerular capillaries through a dilated afferent arteriole. Insulin can be cleared also by muscle, adipocytes, gastrointestinal cells, fibroblasts, monocytes and lymphocytes which contain insulin receptors and internalization and regulation mechanism for insulin metabolism

Main physiopathologic mechanisms involved in hepatic drug reactions

The liver has a pivotal role in drug metabolism and hepatic drug reactions are frequent events, accounting for 5% of cases of jaundice or acute hepatitis in the community. The importance of hepatic drug reactions lies not only in their frequency, but also in the great number of molecules that can cause this type of lesions and in their variable gravity. This review will show the main factors implicated in drug metabolism which can explain the different susceptibility in developing hepatic drug reaction, the possibility that it may manifest as a wide spectrum of clinical syndromes or that a single agent may cause more than one lesion (a relevant problem not only for the clinician, but also for the pathologist)

Enteral diet in Crohn's disease. Nutritional and therapeutic implications in patient's management

Inflammatory bowel diseases (IBD) are often characterized by impairment of nutritional status. Crohn's disease (CD) patients, especially in the active phase of disease, show a reduced body weight, due to the reduction of lipid stores, in spite of lean mass depletion. Fat mass reduction has been correlated to an increased utilization of lipids as fuel substrate. The alterations of nutritional status are able, in turn, to influence, as independent factors, the disease course and patient prognosis. A disease's treatment based only on pharmacologic therapy, especially on corticosteroid use in the active phases, often does not take into account the relevant need for preserving a normal nutritional status. In this connection, enteral nutrition has been shown to be able to improve nutritional status and induce and maintain remission. We present some of the possible mechanisms of efficacy of enteral feeding and some rules to attempt to treat patients with IBD, especially those with Crohn's disease

Wasting in gastrointestinal tract cancers: clinical and etiologic aspects

One of the major complications found in patients affected by malignancy of the gastrointestinal tract is represented by an alteration of nutritional status, up to real cachexia. The factors responsible for the severe nutritional deficiencies are: metabolic alterations, which involve carbohydrate, lipid and protein metabolism; the reduced availability of nutritional substrates, due to neoplastic growth that, by expanding locally or destroying the affected organ, determines alterations of deglutition, digestion and food absorption; the effects of surgical therapy, radiotherapy and chemotherapy, which are able to cause temporary or permanent nutritional deficiencies; the effects of immunological mediators, and above all of tumor necrosis factor-alpha (TNF-alpha). In fact, TNF-alpha is considered the main mediator of cancer cachexia as it is responsible for different metabolic alterations, both directly and by the activation of other mediators, such as lipid mobilizing factor (LMF) and protein mobilizing factor (PMF). In addition, a negative energy balance in cancer patients could occur as a consequence of increased energy requirements. In this connection, patients with different neoplasia localisation, show high or within the normal range energy expenditure values. These data indicate that the increase in energy metabolism is not likely to represent the main determining factor in neoplastic cachexia. In conclusion, since patients affected by malignancy of the gastrointestinal tract showed a reduction in body weight, fat and fat-free mass, accurate evaluation of nutritional status should be useful in the management and follow-up of these patients

Alterations of nutritional status in the main gastrointestinal pathologies

An impairment of nutritional status up to real malnutrition can frequently be associated to gastrointestinal diseases. The diseases of the gastrointestinal tract can be divided into five groups: those hampering the nutrient physiological transit (especially neoplastic diseases); those affecting the intestinal mucosa (such as chronic inflammatory bowel disease); those determining intraluminal maldigestion; the hepato-biliary diseases and finally, the diseases of the pancreas. In order to correctly evaluate the nutritional status of an individual, besides the determination of the common biochemical parameters, body composition by direct and indirect techniques and energy metabolism by indirect calorimetry should be measured. Patients affected by Crohn's disease showed a lower fat mass content along with higher lipid oxidation compared to patients affected by ulcerative colitis. Patients with coeliac disease at diagnosis had a reduction in both fat and fat-free mass content along with an increased utilisation of carbohydrates as fuel substrate. There are many factors potentially leading to severe malnutrition in pancreatic diseases, especially in the acute form. Due to the primary role played by the liver in the metabolism of energy substrates, an impaired nutritional status might be commonly found in cirrhotic patients. In this connection, our group reported an increased energy expenditure and lipid oxidation, and an insulin-resistant state in compensated liver cirrhotic patients. These alterations seemed to precede and probably to lead to liver-disease-related malnutrition