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G Saccomani

Publications and source records attributed to G Saccomani.

At least 19 recordsLinked to original sources
PubMed2005

Combined endoscopic treatment for cholelithiasis associated with choledocholithiasis.

BACKGROUND: The advent of endoscopic techniques changed surgery in many ways. For the management of cholelithiasis, laparoscopic cholecystectomy (LC) is the treatment of choice. This has created a dilemma in the management of choledocholithiasis. Today a number of option exist, including endoscopic sphinterotomy (ES) before LC in patients with suspected common bile duct (CBD) stones, laparoscopic bile duct exploration, open CBD exploration, and postoperative endoscopic retrograde cholangiopancreatography (ERCP). Also, the alternative technique of peroperative ES is emerging. METHODS: We report our experience of routine intraoperative cholangiography followed either by peroperative ERCP in one step or by transcystic drain and postoperative ERCP. In our technique, to facilitate Vater papilla cannulation we inserted a 450-cm transcystic guidewire that was caught by a duodenoscope. Papillotome was then inserted over the guidewire to ensure cannulation of the CBD. RESULTS: Twenty-eight patients were treated successfully in one step and 24 in two steps. The mean operative time was 181 +/- 41 min for patients treated in one step and 131 +/- 30 min for patients treated in two steps. The mean hospital stay was 4.8 +/- 3.3 days for patients treated in one step and 9.6 +/- 4.0 days for patients treated in two steps. Five patients (18%) with positive intraoperative cholangiography for stones for whom peroperative ERCP was not available showed a normal postoperative transcystic cholangiogram and therefore ERCP was canceled. Fourteen of 25 patients treated in one step and none of 17 treated in two steps had raised serum amylase, which resolved spontaneously with no symptoms. No patient developed postoperative pancreatitis. Three (10%) ERCP complications were observed, consisting of mild bleeding of the papilla. All cases were managed by endoscopic adrenaline injection. There was no mortality. CONCLUSION: We believe peroperative ERCP with the technique described should be considered as the treatment of choice for choledocholithiasis associated with cholelithiasis. When single-stage treatment is not possible, a two-step rendezvous technique should be preferred.

Adult↗
PubMed1997

[Preoperative colonic lavage and one-stage excision-anastomosis in obstruction of the left colon].

In a retrospective series of 95 patients requiring emergency surgery for distal colonic obstruction, primary bowel resection followed by immediate anastomosis after intraoperative colonic irrigation was performed. Carcinoma was the cause of obstruction in 81 cases (85%); 13 patients had diverticulitis, and 1 had sigmoid volvulus. The technique of on-table lavage was similar to that described by Dudley in 1980: a caecostomy tube was used in 86 patients (90%) and was removed on the tenth postoperative day. 4 patients died, none from complications of anastomotic leakage. There were three anastomotic leakages (3.1%) and 10 radiologic leaks were observed. 3 patients were reoperated. The mean hospital stay was 23 days. The results of this study suggest that intraoperative colonic irrigation is an effective method, enabling the surgeon to perform primary anastomosis with reasonable safety after emergency resection of selected distal colonic lesions.

Aged↗
PubMed1997

[Extended lymphadenectomy in carcinoma of the right colon].

The Authors report on a retrospective study concerning 49 patients treated for a modified Dukes' stage B, C or D right colon cancer. A potentially curative right hemicolectomy with extended lymphadenectomy was performed. Locally advanced disease was treated by "en bloc" resection. Two (4.1%) patients died after surgery, in other 2 (4.1%) cases major postoperative complications were registered. Microscopic examination of the surgical specimens showed lymph node metastases in 44.9% of the cases: in this subgroup a metastatic involvement of the main (III level) nodal groups was detected in 22.7% of the patients. The Authors conclude that extended lymph node dissection does not increase postoperative complications and may play a role in the treatment of right colon cancer. A not negligible group of patients may be understaged or receive inadequate surgical treatment when submitted to traditional right colectomy.

Aged↗
PubMed1994

LSA--a new liver-specific antigen in the rat. II: Immunological and biological properties.

The immunological and biological properties of a liver-specific antigen (LSA) from rat liver are described. LSA gave interspecies cross-reactions with liver extracts from several mammalian species, but no reaction of complete identify was observed. Moreover, no cross-reaction was found with chicken or frog livers, thus indicating the rather late appearance of LSA in the process of evolution. Experiments with fetal and neonatal liver extracts have indicated that LSA appears late in fetal development and is always present at birth. The biological properties of LSA were explored by several independent approaches. LSAg-Ab immunoprecipitates were stained positively with carbon naphthoxycholine iodide, an indirect evidence of choline esterase activity. LSA was also found to bind bile acids, thus suggesting organic anion properties. Finally, LSA was detected in the circulation of rats with acute carbon tetrachloride- and galactosamine-induced hepatocellular injury. This LSA is immunologically distinct from hepatitis B antigen, alpha-fetoprotein, carcino-embryonic antigen and, from each of several serum and liver proteins tested.

Animals↗
PubMed1993

Gastric parietal cell H(+)-K(+)-ATPase microsomes are associated with isoforms of ankyrin and spectrin.

Stimulation of HCl secretion by gastric parietal cells requires the fusion of cytoplasmic H(+)-K(+)-ATPase-bearing tubulovesicles with the apical membrane. This insertion of membrane results in a dramatic increase in apical surface area through the formation of microvilli. To elucidate the elements that may stabilize the newly inserted H(+)-K(+)-ATPase within the apical membrane, we searched for specific cytoskeletal proteins associating with the gastric enzyme. We document by immunoblot analysis that ankyrin, spectrin, and actin copurify with H(+)-K(+)-ATPase microsomes prepared from gastric parietal cells. Coprecipitation of 125I-labeled native erythrocyte ankyrin with the H(+)-K(+)-ATPase from gastric microsomes using anti-H(+)-K(+)-ATPase antibodies suggests that ankyrin associates with the H(+)-K(+)-ATPase. Indirect immunofluorescence and confocal microscopy show that ankyrin and H(+)-K(+)-ATPase cosegregate within resting and secreting parietal cells. Taken together, these data suggest that the association of the gastric H(+)-K(+)-ATPase with spectrin and actin is mediated by ankyrin and that this interaction contributes to the maintenance of the polarized distribution of the enzyme to the apical domain of gastric parietal cells during acid secretion.

Actins↗
PubMed1992

LSA: a new liver-specific antigen in the rat. I. Purification and characterization.

A liver-specific antigen (LSA) was purified to homogeneity from rat liver by conventional methods of protein chemistry. By consecutive 100,000 g centrifugation, ammonium sulfate precipitation, ion-exchange chromatography on DEAE-cellulose, gel filtration on Sephadex G-200, ion-exchange chromatography on CM-cellulose and affinity chromatography on concanavalin-Sepharose, it has been possible to isolate a preparation that migrated as a single band on SDS-PAGE. This preparation gave a complete identity pattern with the original crude rat liver extract when tested by double immunodiffusion. This antigen has a molecular weight of 72.5 kD with an electrophoretic mobility in the region of alpha 2-globulins. The LSA proved to be thermolabile since exposure to 55 degrees C completely destroyed the antigen. Exposure of the LSA to different pH ranging from 4 to 10 had no detrimental effect on its antigenic activity. The amino acid composition of the LSA revealed that the acidic amino acids out-number the basic amino acids, with glutamic acid being the most abundant of them. Failure of beta-mercaptoethanol to split the LSA molecule suggests the absence of sulfhydryl groups related to its antigenic activity. Subcellular fractionation of rat liver revealed most of the antigenic activity in the 100,000 g supernate, i.e. the soluble cytoplasmic fraction of the liver (cytosol). By contrast, the LSA was absent from isolated Kupffer cells from rat liver. The absence of any carbohydrate or lipid from the purified preparation of this antigen, in conjunction with the destructive effects of trypsin suggest that the LSA is a protein or a moiety closely associated with proteins.

Amino Acids↗
PubMed1991

Amiloride-sensitive sodium channel is linked to the cytoskeleton in renal epithelial cells.

Amiloride-sensitive sodium channels are localized to the microvillar domain of apical membranes in sodium-transporting renal epithelial cells. To elucidate the elements that maintain sodium channel distribution at the apical membrane, we searched for specific proteins associating with the channel. Triton X-100 extraction of A6 epithelial cells reveals that sodium channels are associated with detergent-insoluble and assembled cytoskeleton. Indirect immunofluorescence and confocal microscopy show that sodium channels are segregated to the apical microvillar membrane and colocalize with ankyrin, fodrin, and actin. We document by immunoblot analysis that ankyrin and fodrin remain associated with sodium channels after isolation and purification from bovine renal papillae. 125I-labeled ankyrine can be precipitated by anti-sodium-channel antibodies only in the presence of purified bovine sodium-channel complex. Direct binding of 125I-labeled ankyrin shows ankyrin binds to the 150-kDa subunit of the channel. Fluorescence photobleach lateral-diffusion measurements indicate sodium channels are severely restricted in their lateral mobility. We conclude that ankyrin links the amiloride-sensitive sodium channel to the underlying cytoskeleton and this association may sequester sodium channels at apical microvilli and maintain their polarized distribution in renal epithelial cells.

Amiloride↗
PubMed1991

Synergistic intrarenal actions of angiotensin on tubular reabsorption and renal hemodynamics.

There is a growing awareness that the direct intrarenal actions of angiotensin II (ANG II) on both tubular and vascular structures contribute to sodium conservation. Even very low concentrations of ANG II (10(-1)) mol/L) stimulate proximal reabsorption rate. Recent studies indicate that this stimulatory action is due to an enhanced activity of the sodium/hydrogen exchanger of the luminal membrane. Elevated ANG II levels in the renal interstitium, effected either through increased delivery of ANG II via the circulation or as a consequence of conversion of angiotensin I (ANG I) generated locally, can also enhance proximal reabsorption rate. One consequence of enhanced proximal reabsorption rate is reduced distal volume delivery, which would be expected to elicit arteriolar vasodilation mediated by the tubuloglomerular feedback (TGF) mechanism. It has been observed, however, that peritubular capillary infusions of either ANG I or ANG II, at doses sufficiently low to be without obvious direct effects on glomerular dynamics, can increase the sensitivity of the TGF mechanism. This enhanced TGF sensitivity serves to minimize or prevent TGF mediated increases in glomerular filtration rate in the face of reduced distal delivery. With greater increases in interstitial ANG II concentration, reductions in glomerular pressure have been observed, demonstrating a powerful action on preglomerular arterioles that predominates over the well known effects on efferent arterioles. At these higher doses, the direct hemodynamic actions of ANG II, plus the effects on the glomerular filtration coefficient, will directly reduce filtered sodium load. Through these synergistic effects on both tubular reabsorptive and hemodynamic function, ANG II can elicit sustained decreases in distal nephron sodium delivery which contribute greatly to its efficacy as a regulator of sodium excretion.

Absorption↗
PubMed1991

Histamine-induced chloride channels in apical membrane of isolated rabbit parietal cells.

The electrical properties of the apical membrane of isolated rabbit parietal cells were studied using the patch-clamp technique. The apical membrane of the parietal cells plated on Matrigel and maintained in culture conditions was identified by lectin-binding studies. Cell-attached and excised inside-out patches from 10(-4) M cimetidine-treated parietal cells infrequently contained Cl- channels (9% of the patches). A single class of voltage-dependent outwardly rectifying Cl- channels with 24 +/- 1-pS conductance was observed in 75% of the patches from cells stimulated (acid secreting) by 10(-4) M histamine. Other anions passed through these channels with a permeability sequence of I- (1.2) greater than Br- (1.1) greater than or equal to Cl- (1.0) greater than NO3- (0.7) greater than SO4(2-) (0.1), but there was a very low permeability for Na+ or K+ (PCl-/PNa+ or PCl-/PK+ greater than 5). In inside-out patch configurations the Cl- channel was insensitive to Ba2+ and stilbene derivatives but was inhibited by diphenylamine-2-carboxylic acid in a manner characteristic of a reversible open-channel blocker. It is concluded that H2-receptor agonist stimulation of acid secretion by rabbit parietal cells activates Cl- channels in the apical cell membrane.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1991

[Malignant neoplasms of the male breast. Our clinical contribution].

A survey of literature data on male breast cancer is reported: on this basis the authors report their experience of five cases observed between 1980 and 1989 at Ospedale "S. Corona" Pietra Ligure, out of 500 female breast cancers treated in the same period. Epidemiological data and follow-up records are analysed, reporting survival rate similar to that of larger series.

Adult↗
PubMed1990

Angiotensin II stimulation of Na(+)-H+ exchange in proximal tubule cells.

Experiments were performed to evaluate the effect of angiotensin II (ANG II) on the sodium transport activity of isolated intact rabbit proximal tubule cells. Initial rates of 22Na(+) uptake were measured in Na+-depleted and ouabain-treated cells in the presence of an opposing H+ gradient (pHin less than pHout). ANG II (10(-12)-10(-9) M) stimulated the initial rate of 22Na+ uptake by 33 +/- 2%, whereas amiloride (0.5 mM) inhibited both basal and ANG II-stimulated 22Na+ uptake. ANG II-stimulated rate of 22Na+ uptake was inhibited by the receptor antagonist saralasin. Additional experiments were performed to evaluate the effect of ANG II on the rate of recovery of pHin in acid-loaded proximal tubule cells. Cells were acid loaded by an NH4Cl pulse in the presence of the pH-sensitive fluorescent dye 2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein. ANG II increased the initial rate of intracellular alkalinization, and this effect was inhibited by amiloride (1.0 mM). ANG II stimulation increased the Vmax of H+ efflux (from 0.53 +/- 0.02 to 0.64 +/- 0.04 pH units/min) without changing the Km for extracellular Na+. The present findings indicate that physiological concentrations of ANG II stimulate an amiloride-sensitive Na+-H+ antiport in proximal tubule cells.

Alkalies↗
PubMed1989

On-table colonic irrigation in the treatment of left-sided large-bowel emergencies.

In a series of 27 patients who required surgery for distal colonic lesions, primary bowel resection with immediate anastomosis after intraoperative antegrade colonic irrigation was performed. The technique of on-table lavage was similar to that described by Dudley and Radcliffe in 1980; however, some new technical details are introduced to minimize fecal contamination. There were 17 men and 10 women (mean age, 68.5 years). Twenty patients were admitted for obstructing carcinoma of the left colon; 11 underwent immediate surgery, while the remaining 9 underwent delayed surgery after 12 hours of intravenous fluids and nasogastric suction. Of the remaining seven patients, five had perforated sigmoid diverticula and diffuse peritonitis and two had obstructing diverticular disease of the left colon with remarkable bowel distention. One hospital mortality occurred secondary to a ruptured aortic aneurysm. The radiologic anastomotic leakage rate was 14.8 percent. Clinical anastomotic dehiscence was not observed.

Aged↗
PubMed1989

Interaction of anti-ulcer drugs with the gastric proton pump.

In this review consideration is given to anti-ulcer drugs interaction with the gastric H(+)-K+ ATPase. The review has been divided into three sections. First, properties of the gastric proton pump are described in terms of structure, biological activity and ions transport activity, followed by an account of interactions involving antisecretory agents. Emphasis is given to a new class of drugs (substituted benzimidazole) that shows a unique antisecretory action and is safe and effective for short-term treatment of patients with duodenal or gastric ulcers. The final section briefly examines future directions for the production of more selective inhibitors of the gastric proton pump.

Adenosine Triphosphatases↗
PubMed1987

The epithelial sodium channel. Subunit number and location of the amiloride binding site.

Sodium dodecyl sulfate gel electrophoresis of the radioiodinated native amiloride-sensitive epithelial sodium channel protein isolated from bovine renal papilla and cultured amphibian A6 cells under denatured and nonreduced conditions revealed an 125I-labeled protein band of Mr approximately 730,000. Upon reduction, this protein was resolved into five major polypeptide bands with apparent average Mr values of 315,000, 149,000, 95,000, 71,000, and 55,000. The amiloride analog [3H]methylbromoamiloride has been used as a photoaffinity label to determine the location of the binding site for amiloride on the epithelial sodium channel protein. [3H]Methylbromoamiloride binds covalently to the sodium channel at high affinity binding sites with a half-maximal binding concentration of 0.2 microM. [3H]Methylbromoamiloride was specifically photoincorporated into the Mr approximately 150,000 polypeptide and this incorporation was blocked by addition of excess amiloride. These data suggest that the epithelial sodium channel protein is composed of at least five nonidentical polypeptide subunits, only one of which specifically binds amiloride.

Affinity Labels↗
PubMed1987

Papain fragmentation of the gastric (H+ + K+)-ATPase.

Membrane-bound (H+ + K+)-ATPase purified from hog gastric mucosa was exposed to limited papain digestion. Such treatment resulted in a rapid inhibition of the K+-stimulated adenosine triphosphatase and p-nitrophenyl phosphatase activities, with about 90% of these activities lost after 3 min incubation at 37 degrees C with 0.1 units of papain per mg of enzyme protein. Parallel to the inhibition of the enzyme activities, there was a production of a 77 kDa membrane-bound fragment containing the aspartyl phosphate residue of the phospho-intermediate. This fragment accounted for about 45% of the total enzyme protein after the 3 min papain treatment. The digestion barely affected the steady-state level of phosphorylation, allowed the aspartyl phosphate of the 77 kDa fragment to undergo the transition to the E2P form, and did not significantly alter the fraction of ADP-sensitive phosphoenzyme. The presence of KCl, however, depressed the steady-state level of phosphoenzyme formed from [gamma-32P]ATP considerably less than that of the control enzyme. With further exposure to papain the 77 kDa peptide became fragmented into a 28 kDa soluble peptide that retained the phosphorylating site. Binding of fluorescein 5'-isothiocyanate (FITC) to the native enzyme did not affect the sites of papain hydrolysis because the same peptide fragments were obtained. The FITC reaction site was also in the 28 kDa soluble peptide fragment.

Adenosine Diphosphate↗
PubMed1986

Purification and characterization of the amiloride-sensitive sodium channel from A6 cultured cells and bovine renal papilla.

The amiloride-binding Na+ channel protein of high electrical resistance epithelia was solubilized and purified from cultured A6 toad kidney cells and bovine renal papilla. Purification was assessed by enrichment in [3H]methylbromoamiloride specific binding. Chromatography of 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS)-solubilized plasma membrane vesicles on agarose-immobilized wheat-germ agglutinin provided a 130-fold enrichment of the amiloride-binding component compared to the cell homogenate. Further purification was achieved by either amiloride-affinity chromatography or size-exclusion HPLC. When the HPLC and amiloride affinity-purified material was injected into a second higher molecular weight exclusion HPLC column, only a single peak with Mr 800,000 was found. Further HPLC separation of the Mr 800,000 material at low ionic strength resolved two peaks with apparent Mrs 800,000 and 700,000. Only the 700-kDa component displayed specific [3H]methylbromoamiloride binding activity. The final binding specific activity achieved was 1300 pmol/mg of protein, corresponding to 91% homogeneity of the protein.

Amiloride↗
PubMed1985

Structural relatedness of three ion-transport adenosine triphosphatases around their active sites of phosphorylation.

Three membrane-bound adenosine triphosphatases were investigated for homology in the sequence of four amino acids about the active site of phosphorylation. The ATPases were as follows: sodium-potassium-dependent ATPase from dog kidney, Na,K-ATPase; hydrogen-potassium-dependent ATPase from hog gastric mucosa, H,K-ATPase, an ATPase similar to Na,K-ATPase; and an ATPase activity in the plasma membrane of corn, Zea mays, roots (CR-ATPase), a higher plant ATPase. A membrane preparation containing an ATPase of Acholeplasma laidlawii, a prokaryote, (AL) was also investigated. For most of the experiments, the preparations were phosphorylated from [gamma-32P]ATP, denatured in acid, and subjected to proteolytic digestion. Radioactive phosphopeptides were separated by high voltage paper electrophoresis and characterized by sensitivity to chemical reagents. In gastric H,K-ATPase, the aspartate residue at the active site was determined directly by labeling with [3H]borohydride. A common sequence around the active site was found for Na,K-ATPase, H,K-ATPase, and CR-ATPase. This sequence, -Cys-(Ser/Thr)-Asp(P)-Lys-, is similar to that in the calcium ion-transport ATPase of sarcoplasmic reticulum. The AL membrane preparation showed an acylphosphate that turned over rapidly after a chase of labeled membranes with unlabeled ATP. The corresponding sequence was different from that of the three ATPases. An acylphosphate was on two polypeptides with molecular weights of about 80,000 and 60,000; these appear not to correspond to subunits of a Na+-stimulated ATPase in this organism (Lewis, R. N. A. H., and McElhaney, R. N. (1983) Biochim. Biophys. Acta 735, 113-122).

Adenosine Triphosphatases↗