Role of growth hormone in regulating lipolysis, proteolysis, and hepatic glucose production during fasting

CONTEXT: Fasting is associated with suppressed insulin and augmented GH secretion. The involvement of each mechanism in the regulation of fuel mobilization during fasting is unknown. OBJECTIVE: To ascertain the role of GH in the regulation of the rates of lipolysis, proteolysis, and hepatic glucose production (HGP) during the physiological daily feed/fast cycle and after 2 d of complete fasting, we used a model of selective GH suppression by the administration of GHRH receptor antagonist (GHRH-A). DESIGN AND SETTING: We conducted an open label in-patient study in the General Clinical Research Center at the University of Michigan. PARTICIPANTS: Six healthy, nonobese volunteers participated. MAIN OUTCOME MEASURES: We assessed 24-h plasma GH concentration and rates of lipolysis, proteolysis, and HGP using stable isotope techniques after an overnight fast and after 2 d of fasting. RESULTS: GHRH-A suppressed plasma GH by about 65% during the fed state (P = 0.015) but did not alter the rates of lipolysis, proteolysis, or HGP. Fasting for 2 d suppressed plasma insulin concentration by about 80% and elevated plasma GH about 4-fold (both P < 0.01). This was accompanied by a doubling in the rate of lipolysis, an approximately 40% increase in proteolysis, and an approximately 30% decline in HGP (all P < 0.05). Preventing the fasting-induced increase in GH with GHRH-A largely abolished the increase in the rate of lipolysis. GHRH-A also augmented the fasting-induced reduction in HGP but did not alter proteolysis. CONCLUSIONS: Endogenous GH plays a very limited metabolic role during the daily feed/fast cycle but is essential for the increased lipolytic rate found with more prolonged fasting.     

Many people admitted to hospital with a provisional diagnosis of nonserious back pain are subsequently found to have serious pathology as the underlying cause

Clinical Rheumatology - To determine the proportion of patients admitted to the hospital for back pain who have nonserious back pain, serious spinal, or serious other pathology as their final...     

A single pentylenetetrazole-induced clonic-tonic seizure episode is accompanied by a slowly developing cognitive decline in rats

According to different studies, between 5% and 10% of people suffer a single isolated seizure episode at some time in their life. However, little is known about the effects of a single seizure episode on cognitive function, and clinical investigations of this issue are not easy to perform. In this situation, animal models may be a reasonable choice. The aim of our study was to follow the time course of delayed effects of generalized clonic-tonic convulsions on learning and memory functions in rats. A clonic-tonic seizure episode was induced by a single i.p. injection of pentylenetetrazole (70 mg/kg). Different behavioral tests were performed between days 10 and 100 after the convulsant administration. A single seizure episode resulted in a gradual decline in short-term memory function as assessed by novel object recognition and social recognition tests. The seizure episode induced a quick increase in hippocampal cell proliferation; however, the excessive newly generated cells seemed to be eliminated by the time of obvious cognitive impairment. These observations are indicative of a slowly developing and long-lasting influence of a single seizure episode on cognitive function. A rather long time period between the seizure episode and the manifestations of cognitive decline provides a window for a possible therapeutic intervention, and an elaboration of such “post-conditioning” treatments may be a promising opportunity to prevent subsequent mental impairments in patients.     

Probiotics in the critically ill patient: a double blind, randomized, placebo-controlled trial

Purpose  

Probiotics have been shown to be able to restore a non-pathogenic digestive flora, to prevent digestive colonization by pathogenic bacteria, and to modulate immunity. The aim of this study was to assess the effects of prophylactic probiotic administration in patients ventilated for up to 2 days.