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Biomedical subjects

G Esposito

Publications and source records attributed to G Esposito.

At least 271 records · Page 15Linked to original sources
PubMed1984

Effects of the stilbene derivatives SITS and DIDS on intestinal ATPase activities.

4-Acetamido-4'-isothiocyano-2,2'-disulfonic stilbene (SITS) and 4,4'-diisothiocyano-2,2'-disulfonic stilbene (DIDS) effects have been tested both in the basolateral membranes (BLMs) of jejunum enterocytes and in the same intestinal tract, everted and incubated "in vitro". Total and (Na,K)-ATPase activities of BLMs are inhibited in a similar way by the two disulfonic stilbenes as well as the fluid transintestinal transport in the everted intestine; on the contrary cell Na and K are unaffected. SITS and DIDS inhibition of (Na,K)-ATPase seems to take place at the cytoplasmic side of the BLM.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1984

Infected and ruptured urachal cyst causing peritonitis.

Urachal cysts are rare and usually as asymptomatic until they become infected. The route the infection follows is uncertain. A very unusual case is reported of a newborn female afflicted with a posteriorly ruptured urachal cyst causing incapsulated peritonitis, in which we obtained a visualization of the cyst during fistulography

Diagnosis, Differential↗
PubMed1984

The effects of an energy stimulator on blood electrolyte and lactate levels in athletes under training.

The effects of a mineral-vitamin-sugar preparation has been tested on a group of volley ball players under training. Plasma electrolytes (Na, K, Cl), erythrocyte electrolyte content, plasma lactate concentration and erythrocyte water content have been determined before and after a training session in three different experimental situations: a) controls; b) acute treatment with the energy stimulator; c) chronic treatment (8 days) with a similar preparation of the energy stimulator. The results are indicative of a significantly lower lactate production and a more stable electrolyte concentration after treatment with respect to the control data.

Chlorides↗
PubMed1983

Influence of the ionic environment on the conformation of aspartic acid and possible relevance to its neurotransmitter action.

The conformational changes of aspartic acid, a possible neurotransmitter, induced by increasing ionic strength were investigated by means of NMR spectroscopy. The effects of Li, Na, K, and Cs chlorides in basic and neutral conditions were characterized. The effects of the presence of both Ca2+ and Na+ or K+ were also examined. The results always showed a relative stabilization of the two conformers with gauche carboxylates at the expense of the anticonformer. The significant quantitative difference found between Na+ and K+ in basic solutions, as well as between calcium-free and calcium-containing solutions, may bear some relevance for the role of aspartate as a CNS neurotransmitter.

Aspartic Acid↗
PubMed1983

Bicarbonate uptake by basolateral membrane vesicles from rat jejunum.

Basolateral membranes from rat jejunal enterocytes have been obtained by self-orienting Percoll-gradient centrifugation. Bicarbonate and L-glucose uptake into osmotically active basolateral membrane vesicles has been studied by a rapid filtration technique. In closed vessels and at pH 8.2 the uptake kinetics of both [14C]bicarbonate and L[3H]glucose have been followed for 30 min at 18 degrees C. Bicarbonate uptake seems to be fast and in efflux experiments SITS and DIDS effect is negligible. This work demonstrates that it is possible to determine bicarbonate flux across basolateral membrane vesicles at pH and temperature values close to usual experimental conditions.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1983

Use of a dacron prosthesis for relief of superior vena cava obstruction in a child with thymoma.

A case of thrombosis of superior vena cava in a child with thymoma is reported and the necessity of an exact definition of vascular lesions in thymopathies underlined. The innominate veins and the superior vena cava should be visualized preoperatively to program an appropriate radical surgical treatment particularly when these vessels are affected by the tumor.

Blood Vessel Prosthesis↗
PubMed1983

Intestinal absorption. I - General principles of transintestinal transport.

The paper deals mainly with the principles and the basic mechanisms underlying the transport processes of molecules across biological membranes. The simple diffusion of electrolytes and non-electrolytes, the chemically-facilitated diffusion and the active transport are briefly discussed. These transport mechanisms are utilized also by substances moving through the intestinal epithelium even if this tissue has a rather complex structure.

Biological Transport, Active↗
PubMed1982

In vivo and in vitro sugar transport in frog intestine.

In the frog intestine, both in vitro and in vivo, experiments were carried out in order to increase knowledge of the mechanism of sugar exit across the basolateral membrane of the enterocyte. The frog intestine was chosen because it lacks crypt cells and, consequently, any external fluid circuit mechanism during sugar transport can be avoided. Therefore, the sugar concentration in the absorbate collected on the serosal side is likely to be similar to that present underneath the basolateral membrane of the enterocyte. Under this condition, cell and absorbate sugar concentrations are similar; yet there is a concomitant net transintestinal sugar transport. Moreover, in in vivo experiments a net transintestinal sugar transport takes place even against a concentration difference. These results suggest that sugar exit across the basolateral membrane is not simply due to a chemically facilitated diffusion.

3-O-Methylglucose↗
PubMed1982

d-Glucose balance in the enterocyte of rat jejunum "in vitro".

An everted sac of male albino rat jejunum (Wistar strain) incubated "in vitro" in used. Net d-glucose and Na+ transport together with d-glucose concentration in the emerging fluid [5], or in ths serosal fluid, and in the enterocytes are determined. Cell d-glucose concentration does not change significantly in a range between 20-200 mumoles or between 50-500 mumoles of net d-glucose transepithelial transport, depending on the experimental conditions. As far as cellular d-glucose and Na+ concentration is concerned, the enterocyte behaves as an homeostatic system. The mechanism involved in d-glucose extrusion is extensively discussed. Two hypothesis seem to be possible. First, the mechanism is an active metabolically dependent one, just as it is for sodium transport. Second, the metabolic activity favours d-glucose facilitated permeability through the basolateral membrane in such a way as to maintain a constant relationship between d-glucose and Na-extrusion, notwithstanding the fact that d-glucose concentration gradient across the basolateral membrane lowers by increasing Na and glucose extrusion rate.

Animals↗
PubMed1982

Congenital pulmonary arterio-venous fistula in childhood.

Pulmonary arterio-venous fistula is a rare congenital lesion of the pulmonary vasculature, causing cyanosis in children. The lesion can be solitary or multiple, usually involves the lower lobes and is often associated with the Rendu-Osler-Weber syndrome. The case of a 9-year-old boy is reported in whom diagnosis was made on pulmonary angiophotoscintigraphy and confirmed at angiography. The usual treatment of choice of these lesions is lobectomy which promptly relieves the symptoms.

Angiography↗
PubMed1982

ph-dependent, HCO-3-stimulated ATPase of rat jejunum.

Mucosal homogenates from rat jejunum were tested for both HCO-3-stimulated ATPase and anion-stimulated, SCN-inhibited ATPase in assay mixtures ungassed, gassed with pure oxygen or gassed with the appropriate gaseous phase. Experiments were performed at four different initial pHs (7.15; 7.45; 8.10; 8.55) with or without the presence of Triton X-100. Assay mixtures were tested for both pH and % CO2. Only at pH 7.15 and 7.45 anion-sensitive ATPase activities in ungassed conditions are different from those in mixtures gassed with the proper gaseous phase. Moreover, at cited pHs in ungassed mixtures the final pH is higher and % CO2 is lower than initial values. Therefore it seems possible to obtain the exact determination of anion-sensitive ATPases at all pH values only from mixtures gassed with the proper gaseous phase. Bicarbonate-stimulated ATPase activity is absent both at pH 7.15 and 7.45; this fact seems to exclude, at these pHs, an active transport of bicarbonate directly depending on this enzyme activity.

Adenosine Triphosphatases↗
PubMed1982

Recent advances in diagnostic techniques in Caroli's disease.

Preoperative diagnosis of congenital dilatation of the intrahepatic bile ducts (Caroli's disease) is difficult. The best techniques for this diagnosis are endoscopic retrograde cholangiopancreatography, abdominal ultrasonography and computerized tomography. The authors present a case of Caroli's disease diagnosed using ultrasonography and computerized tomography. They discuss the usefulness and the real possibilities of existing techniques in the diagnosis of intra- and extrahepatic bile duct disease.

Adult↗