Acute pancreatitis: a review of pathophysiology and nutrition management.

Acute pancreatitis (AP) is an acute inflammatory process of the pancreas that may involve peripancreatic tissue or remote organs. In its more severe forms, it is a significantly catabolic illness for which specialized nutrition support is required. This review summarizes the pathophysiology of AP, the severity grading systems used in its evaluation, and general treatment strategies, and reviews the value of enteral tube feeding and parenteral nutrition in supporting the patient with this common disease.     

The pathophysiology and treatment of cancer cachexia.

Cachexia in cancer patients is a major cause of morbidity and mortality. The syndrome of cachexia seems to be a facet of the inflammatory response to injury. This proinflammatory state is driven by an interdependent web of mediators such as cytokines, neurotransmitters, prostaglandins, neuroendocrine hormones, and tumor-derived catabolic factors. The resulting metabolic response to cancer prevents the effective use of calories provided and therefore blocks anabolism. The most promising interventions in cancer cachexia seem to depend on modulation of the inflammatory state (including nonsteroidal anti-inflammatory drugs and fish oil-based preparations). Suppression of the inflammatory milieu seems to allow nutrition to have an anabolic effect, resulting in gains in lean tissue with the potential to improve patient survival and quality of life.     

The pathophysiology of precocious puberty

Advances in understanding of normal puberty have clarified many of the mechanisms underlying precocity and led in several instances to better therapy. The essential diagnostic task is to determine if the normal process has been triggered prematurely or if an abnormal process (usually inappropriate sex steroid secretion) has circumvented the normal physiology.     

Physiology and pathophysiology of senescence.

Average life-span and maximum life-span are the two basic parameters by which the processes of ageing and senescence of individuals of a species are characterized. Although each individual of a species if affected by both parameters can only be studied in populations of individuals. The survival curve of a cohort of individuals reflects the different influences of constitutional and environmental factors on life expectancy. The intrinsic molecular and cellular mechanisms by which the physiological process of ageing and senescence is controlled and regulated are far from being understood although a large number of hypotheses have emerged over the decades. Stochastic and deterministic models of the ageing process have been developed but a theory unifying the large body of experimental, epidemiological and clinical findings is still lacking. In this contribution a brief review is presented on the different hypotheses aiming at explaining the physiology and pathophysiology of ageing and senescence.     

The pathophysiology of irritable bowel syndrome

The irritable bowel syndrome (IBS) is a frequent gastrointestinal disorder (10 -15% of the population).It is characterized by chronic abdominal pain with modification in the bowel habits. The diagnosis is based of ROME II criteria. The pathophysiology of the SII remains unknown . It result from visceral hypersensitivity with anomalies of the digestive motility. These anomalies are secondary of dysfunction of the brain - gut axis modulated by environmental and the psychosocial factors. The understanding of the pathophysiological mechanisms of the SII and in particular the function of the brain-gut axis will permit a better handling of the patients. Indeed, the present knowledge of the neurotransmitter implied in the communication between the central nervous system and the digestive tract are currently the basis of the new therapies aimed to modulate the mechanisms implicated in the causation of the several symptoms of IBS. These novel pharmacotherapy should reduce the indirect societal and costs of IBS.