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Biomedical subjects

E Bartoli

Publications and source records attributed to E Bartoli.

At least 181 records · Page 10Linked to original sources

Volume reabsorption by the loop of Henle: a micropuncture study.

The observed extension of glomerulo-tubular beyond the proximal tube is thought to be due either to flow dependent reabsorption by non-accessible proximal segments and pars recta, or to osmotic volume flow out of the descending limb of the loop of Henle.

Animals↗

Blunting of furosemide diuresis by aspirin in man.

Experiments were performed on humans to study the blunting on the diuretic action of furosemide by prostaglandin synthetase inhibitors. Maximal water diuresis was instituted. At the peak of urine flow, clearance periods were performed during baseline conditions and repeated after the injection of aspirin and, subsequently, of furosemide. Control subjects did not receive aspirin. Urine flow rate (V), Cosm, and Na excretion (UNa) . V were significantly lower when the administration of the diuretic had been preceded by that of aspirin. In the absence of furosemide, however, aspirin did not influence renal hemodynamics nor Na and water reabsorption. Therefore, the same experimental protocol was repeated in paired experiments where each normal subject served as his own control, being studied twice, in the presence and absence of aspirin, respectively. The average changes in water and Na excretion induced by furosemide were not different when the patients were pretreated with aspirin as compared with those measured in the absence of prostaglandin inhibition. Changes occurring in individual experiments were significantly correlated (r = 0.95, P less than 0.01) with those in calculated furosemide clearance. Since aspirin, indomethacin, and meclophenamate are secreted by the organic acid transport system of the proximal tubule, competition for a common secretory mechanism, rather than prostaglandin inhibition, could mediate the blunting of furosemide diuresis.

Aspirin↗

Multicentric giant lymph node hyperplasia. A hyperimmune syndrome with a rapidly progressive course.

A patient who had diffuse lymph node enlargement, fever, skin rashes, anemia and polyclonal hypergammaglobulinemia is described. Histologic examination of lymph nodes taken from different sites (cervical, axillary and inguinal) revealed the presence of giant lymph node hyperplasia. The liver and bone marrow showed a moderate lymphocytic and plasma cell infiltration. The clinical presentation of a multicentric variety of giant lymph node hyperplasia in the reported case is similar to the clinical features usually associated with angio-immunoblastic lymphadenopathy with dysproteinemia, indicating that these two disorders may be related and may affect the same organs and systems. Alternatively, this histologic reactive giant lymph node hyperplasia progressing with a rapid declivitous course can be considered distinctive of a separate entity.

Aged↗

Acute agnogenic myeloid metaplasia with chromosomal abnormalities.

A case of a 37-year-old woman presenting with acute agnogenic myeloid metaplasia (AAMM) is described. The disease had a stormy course and was characterized by moderate splenomegaly, persistently depressed WBC counts, extramedullary hemopoiesis and presence of a high percentage of atypical myeloblasts in the peripheral smear. Platelets were persistently low, reticulocytes significantly below normal, notwithstanding anemia. Hot tended to fall progressively to intolerably low values in the absence of transfusion. The chromosomal mapping of peripheral blood revealed the presence of a trisomy of chromosome No. 8. This abnormality already demonstrated in two previous cases of acute myelofibrosis and the clinical course of the disease suggest that acute myelofibrosis and AAMM could be the same disease while chronic myelofibrosis should be considered a separate entity. Also, it is possible that AAMM with trisomy of chromosome No. 8 and stormy clinical course may be a different entity from the acute myeloproliferative disorders associated with other chromosomal abnormalities.

Acute Disease↗

Acute hepatitis with bridging necrosis due to hydralazine intake. Report of a case.

A 59-year-old woman was admitted to the hospital for evaluation of her hypertension. She was treated with hydralazine; two days later a severe acute hepatitis supervened. On discontinuation of the agent, the liver damage disappeared, relapsed during inadvertent rechallenge, and healed following permanent withdrawal from the drug. Histologic study of the liver showed severe acute hepatitis with bridging necrosis (so-called subacute hepatitis). Six months after discontinuation of hydralazine, a second liver biopsy specimen showed a complete remission of the disease. This hydralazine-induced hepatitis appears to be fully reversible and to differ both on clinical and histological grounds from two previous reports documenting a granulomatous liver disease.

Acute Disease↗

Reabsorption of sodium in the proximal renal tubule in cirrhosis of the liver.

Proximal tubular reabsorption was examined in patients with liver cirrhosis and ascites by a variety of indirect methods. Maximal diluting ability, urine flow rate, and free water clearance were reduced. During frusemide administration V/GFR was lower than in normal control subjects, indicating that proximal fractional reabsorption is enhanced in liver cirrhosis. This, by reducing Na delivery to the loop of Henle, impairs maximal urine osmolality. Mannitol, by reducing proximal reabsorption, restores availability of Na to the loop and urine concentrating ability during osmotic diuresis, whereas volume expansion with dextran was ineffective. This could be due to a persistent increase in renal vascular resistance preventing the rise in interstitial pressure responsible for driving fluid back into the proximal tubular lumen.

Absorption↗

A study in vivo of peritubular oncotic pressure and proximal tubular reabsorption in the rat.

1. Peritubular capillary microperfusion was used to examine the effects of protein-free and hyperoncotic homologous plasma on fluid reabsorption by proximal convoluted tubules in the hydropenic rat. 3H-labelled p-aminohippurate was added to perfusates for the purpose of estimating the extent to which tubules under study were bathed by the perfusates. [14C]Mannitol was added to perfusates in order to detect contamination of collected tubular fluid by perfusates. 2. Hydrostatic pressures were monitored in the peritubular microvasculature and adjacent proximal tubules during perfusion. Evidence for secretion of p-aminohippurate from perfusate into tubules under study was determined by collecting tubular fluid from both early and late puncture site. Fractional and absolute reabsorption were not affected by either the protein-free or the hyperoncotic plasma. 3. When acetazolamide was added to the perfusate both fractional and absolute reabsorptive rates decreased by an average of 36%, indicating that the techniques were capable of detecting a decrease in proximal tubular reabsorption. 4. It is concluded that under the conditions of this study changes in peritubular capillary protein concentrations have no detectable effect on the rate of proximal convoluted tubule fluid reabsorption.

Absorption↗

Effect of intraluminal flow on proximal tubular reabsorption.

Micropuncture techniques in the rat were used to reinvestigate the possibility that intraluminal flow rate per se may influence net volume reabsorption by the proximal tubule. An experimental design was devised which lowered intraluminal flow without affecting filtration rate of the nephron under study or without directly affecting other renal hemodynamics. In 11 rats flow of tubular fluid between early and late proximal tubular sites was reduced by partially collecting tubular fluid at the early puncture site. In 42 nephrons the rate of flow of tubular fluid was reduced an average of 45% without changing nephron filtration rate and there was an associated reduction in reabsorption between the two sites which averaged 29%. This indicated 63% balance between delivery of tubular fluid and the rate of reabsorption between two sites along proximal tubules. The results of these studies indicate that a reduction in delivery of normal filtrate along the proximal tubule is associated with a concordant reduction in the absolute rate of reabsorption. Since this relationship occurred in the absence of changes in renal hemodynamics or even a change in filtration rate of the nephron under study it is concluded that changes in intraluminal load per se play an important role in the phenomenon of glomerulotubular balance.

Absorption↗