Delay in Renal Hemodynamic Response to a Meat Meal in Severe Obesity.

BACKGROUND/AIMS: Little information is available about the tubular functions and the renal adjustments that take place in obese subjects after a protein meal. How the excess fat may affect renal response to dietary proteins is currently only partially understood. This paper aims to address (i) whether severe obesity, in the absence of other comorbidities, is responsible of kidney dysfunction at either the glomerular or the tubular level and (ii) whether it compromises renal adaptations to a large protein meal. METHODS: Twenty-eight obese subjects without albuminuria, along with 20 control subjects, age and gender matched, have been studied. The glomerular filtration rate (GFR; inulin clearance), renal plasma flow (p-aminohippurate clearance), the proximal tubular function (lithium clearance), the fractional excretion of sodium (FPRNa) have been measured at the basal level (steady state) and after a protein meal (perturbation). RESULTS: Under steady state conditions, filtration fraction, proximal tubular sodium handling and the FPRNa were not significantly different in non proteinuric obese subjects compared with controls. However, a protein meal led to a delayed glomerular hyperfiltration in obese patients compared with controls. CONCLUSION: This study shows that obese patients, in the absence of significant comorbidities, have a normal proximal tubule Na+ absorption at basal; conversely, these subjects showed a different response to a protein meal compared with normal subjects in terms of changes of GFR. Overall, these results suggest that the modified hemodynamic response to a protein meal might be the earliest hallmark of future kidney dysfunction in obese subjects.

Coagulation disorders in uremia.

In patients with end-stage renal disease on maintenance hemodialysis, coagulation abnormalities such as hypercoagulability and thrombosis are common. Thrombotic complications in uremic patients are frequent and include those occurring at the vascular access and in the coronary, cerebral, and retinal arteries. Data do not entirely clarify the mechanisms involved and further investigations are necessary. Here we show a summary of coagulation and fibrinolytic disorders in uremia and the novelties foreseen in molecular biology.

Constructing clinical science.

Clinical practice became clinical science in the years 1720-1820. There were many reasons for this transformation. The discoveries by Santorio Santorio, William Harvey, Marcello Malpighi, Giovanni Alfonso Borelli, Lorenzo Bellini, Thomas Sydenham, Giovanni Maria Lancisi, were perceived by students who asked for changes in the medical curriculum. In 1761 Morgagni centered the study of diseases on morbid anatomy, a way to control at autopsy the validity of diagnosis. J.P. Frank who worked on public health and John Locke who supported a method of scientific reasoning based on asking questions were also instrumental for changes. Hospitals, formerly hospices for the poor, became places for curing and healing. Military hospitals represented models to be followed. In Vienna Marie Therese inaugurated the Allegemein Krankenhaus in 1785. In revolutionary France Fourcroy with the law Frimaire An III, 1794 gave a new rationale. Medicine and surgery were unified in the curriculum. Basic sciences were introduced. Dissection became compulsory, practical teaching became the rule. But it was with John Hunter, Domenico Cotugno and P. Joseph Desault that the great advancement was achieved. They were anatomists and therefore they made the knowledge of human body the core of medical curriculum. However experimentation on animals, as well as practical bedside teaching at the hospital also became important. Through their work hospitals and universities were associated in a common goal.

Renal function in space: the link between osteoporosis, hypercalciuria, and aquaporins.

This article reviews bone adaptation to microgravity, during manned space missions, in humans undergoing Head Down Tilt (HDT) and in Hind-Limb-Suspended Rats. Under microgravity conditions, bone loss occurs in association with hypercalciuria, which in turn modulates Aquaporin 2 (AQP2) excretion in urine, thus avoiding stone forming in space. This report discloses the need to prevent bone loss in order to prepare for long stays at lunar bases or voyages to Mars.

Anasarca caused by Cryptococcus neoformans after heart transplantation.

Cryptococcosis is an opportunistic infection caused by the yeast-like fungus Cryptococcus neoformans. The infection predominantly strikes patients with cell-mediated immunodeficiency, that is, patients with organ transplants, leukemia, lymphoma, AIDS, and those receiving steroids or immunosuppressants. We describe a patient with skin lesions and anasarca secondary to intestinal infection from Cryptococcus neoformans after heart transplantation. We based diagnosis on histologic examination of the cutaneous lesions and of the duodenal mucosa. This case demonstrates that in immunosuppressed patients with anasarca of unknown origin, a diagnosis of intestinal opportunistic infection also should be considered.