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Biomedical subjects

C Marco

Publications and source records attributed to C Marco.

At least 19 recordsLinked to original sources
PubMed1999

Laparoscopic ultrasound guidance for laparoscopic resection of benign gastric tumors.

Laparoscopic excision of gastric leiomyoma is technically feasible and safe, but it may fail to localize the exact placement of the lesion because of the lack of tactile sensitivity. The authors present two cases of small gastric leiomyomas that were resected by a totally laparoscopic approach, assisted with intraoperative laparoscopic ultrasonography because the lesions could not be palpated. A gastric wedge resection with tumor-free margins was performed with an endostapler device. Use of a harmonic scalpel to divide the gastroepiploic vessels facilitated the laparoscopic procedure.

Aged↗
PubMed1998

Incorporation of exogenous precursors into neutral lipids and phospholipids in rat hepatocytes: effect of ethanol in vitro.

We studied the incorporation of different radioactively labeled exogenous substrates into the lipids of rat hepatocytes previously incubated with ethanol. Glycerol, oleate, and serine were all incorporated into neutral lipids to a significantly greater degree in the presence of ethanol, the increase in radioactivity in the triacylglycerol fraction being quite substantial. A similar ethanol-induced increase was found in the incorporation of these substrates into the various phospholipids. This lipogenic activity did not occur when the metabolism of ethanol was blocked by 4-methylpyrazole, an inhibitor of hepatic ADH (alcohol:NAD+ oxidoreductase, EC 1.1.1.1) activity, thus demonstrating that one of the initial effects of ethanol on lipid biosynthesis was mediated by some products of its metabolism in the liver. The only alteration that persisted in the presence of 4-methylpyrazole was an inhibitory effect on the esterification of free cholesterol from oleate, suggesting that ethanol specifically inhibits hepatic ACAT (acyl CoA:cholesterol O-acyltransferase, EC 2.3.1.26) activity.

Alcohol Oxidoreductases↗
PubMed1998

How, when, and why bile duct injury occurs. A comparison between open and laparoscopic cholecystectomy.

BACKGROUND: Bile duct injury (BDI) is a severe complication of laparoscopic cholecystectomy (LC). There is general agreement about the increase of this complication after LC vs open cholecystectomy (OC), but comparative studies are scarce. The aim of this paper has been to compare the incidence and clinical features of BDI after LC vs open procedures. MATERIALS AND METHODS: 3,051 OC, performed from June 1977 to December 1988 were retrospectively analyzed and compared with 1,630 LCs performed from June 91 to August 96, for which data were prospectively recorded. Age, sex, type of BDI, performance of intraoperative cholangiography (IOC), underlying biliary pathology, morbidity, mortality, and late morbidity were all analyzed. RESULTS: BDI incidence was higher in group II (LC) (N: 16, 0.95%) than in group I, (OC, N: 19. 0.6%). BDI incidence was also higher in the group of patients in which it was necessary to convert to an open procedure (3/109, 2.7%, p < 0.05). BDIs were more frequently diagnosed intraoperatively in group I (OC, 18/19) than in group II (LC, 12/16). In both groups, BDI was more prevalent in cases operated by staff surgeons than residents, mainly in complicated gallbladder patients, with a bile duct of less than 7-mm diameter. Morbidity, postoperative stay, mortality, and late morbidity were similar after a BDI in both types of approach. CONCLUSIONS: (1) BDI increases with LC. (2) BDI after LC carries a similar postoperative morbidity and mortality to those after OC. (3) Incidence of BDI in converted cases increases significantly and this constitutes a high-risk group.

Aged↗
PubMed1998

Retroperitoneal liposarcomas. Study of 10 cases.

INTRODUCTION: Retroperitoneal liposarcomas are unusual tumors. Their biological and clinical features different from other retroperitoneal sarcomas. AIM: To analyze our series of retroperitoneal liposarcomas. PATIENTS AND METHODS: Retrospective study of 10 patients with retroperitoneal liposarcoma diagnosed in the last 16 years at our institution. Symptoms, diagnosis, treatment and prognosis were analyzed. RESULTS: Radical resection was done in all cases. Postoperative mortality was 10%. Complementary treatment was considered in each patient. Recurrent disease occurred in 8 patients (14 recurrences), during follow up. In 42% of them recurrences were resected. Actuarial 5-year survival rate was 44%. CONCLUSION: Poor prognosis of retroperitoneal liposarcoma is due to its high recurrence rate.

Adult↗
PubMed1996

Nocturnal rise of leptin in lean, obese, and non-insulin-dependent diabetes mellitus subjects.

We studied 24-h profiles of circulating leptin levels using a sensitive and specific RIA in lean controls and obese subjects with or without non-insulin-dependent diabetes mellitus (NIDDM) during normal routine activity. Serum leptin levels were significantly higher in obese (41.7 +/- 9.0 ng/ml; n = 11) and obese NIDDM (30.8 +/- 6.7; n = 9) subjects compared with those in lean controls (12.0 +/- 4.4, n = 6). In all the three groups, serum leptin levels were highest between midnight and early morning hours and lowest around noon to midafternoon. The nocturnal rise in leptin levels was significant when data were analyzed by ANOVA (lean: F = 3.17, P < 0.0001, n = 4; obese: F = 2.02, P < 0.005, n = 11; and obese NIDDM: F = 4.9, P < 0.0001, n = 5). The average circadian amplitude between acrophase and nadir was 75.6% in lean, 51.7%, in obese and 60.7% in obese NIDDM groups, respectively. No significant correlations (P > 0.05) were observed between circulating levels of leptin and either insulin or glucose levels in any of the 20 subjects studied for 24-h profiles. The nocturnal rise in leptin observed in the present study resembles those reported for prolactin, thyroid-stimulating hormone, and free fatty acids. We speculate that the nocturnal rise in leptin could have an effect in suppressing appetite during the night while sleeping.

Adult↗
PubMed1996

Studies on phospholipid biosynthesis in hepatocytes from alcoholic rats by using radiolabeled exogenous precursors.

We have studied the synthesis of phospholipids in hepatocytes isolated from chronically ethanol-treated rats by using isotopically labelled serine, ethanolamine, and choline as exogenous precursors. Our results demonstrate that ethanol induces specific effects on the biosynthesis of phosphatidylethanolamine and phosphatidylcholine via CDP-derivatives and also on the synthesis of phosphatidylserine via the Ca(++)-dependent base-exchange reaction. Thus, the synthesis of phosphatidylethanolamine from [3-H]ethanolamine and the incorporation of [3H]serine into phosphatidylserine were clearly higher in hepatocytes from ethanol-treated rats compared to controls. The synthesis of phosphatidylcholine from [methyl-14C]choline, on the other hand, decreased markedly, suggesting a specific inhibition of cholinephosphotransferase activity. We have also demonstrated that the phosphatidylcholine levels are markedly decreased in hepatocytes isolated from chronically ethanol-treated rats as a consequence of the lower phosphatidylcholine biosynthesis. The decrease in the incorporation of radioactivity from choline to betaine, which we also found, is interpreted as being the result of a higher use of betaine as methyl donor instead of methionine to maintain the hepatic S-adenosylmethionine levels in chronic alcoholism.

Alcoholism↗
PubMed1996

Evidence of differential effects produced by ethanol on specific phospholipid biosynthetic pathways in rat hepatocytes.

1. The aim of the present study was to investigate the effects of ethanol in vitro on the phospholipid biosynthetic pathways in hepatocytes isolated from the rat. We have used [methyl-14C]-choline, [1-3H]-ethanolamine and L-[3-3H]-serine as exogenous precursors of the corresponding phospholipids, phosphatidylcholine (PC), phosphatidylethanolamine (PE) and phosphatidylserine (PS). 2. Incubation of hepatocytes in the presence of ethanol significantly alters the incorporation of radiolabel from [14C]-choline and [3H]-ethanolamine into the metabolic intermediates and the final products of the CDP-choline and CDP-ethanolamine pathways. Radioactivity in the metabolic intermediates of both pathways was significantly decreased and the amount of label in PE was reduced whilst that of PC was not modified. 3. In the presence of 4-methylpyrazole, an inhibitor of alcohol dehydrogenase (ADH) activity, ethanol produces a reduction in the label of choline phosphate, ethanolamine phosphate and a significant decrease in the amount of PC and PE radiolabel. 4. On the other hand, ethanol increases the incorporation of serine into phosphatidylserine, phosphatidylethanolamine and phosphatidylcholine, although this effect is observed only in the absence of 4-methylpyrazole, indicating that this alteration is produced by some metabolite generated as a consequence of hepatic alcohol metabolism. 5. Ethanol also interferes with the methylation of phosphatidylethanolamine produced via the CDP-ethanolamine pathway but it does not alter phosphatidylethanolamine methylation when this phospholipid is produced by mitochondrial phosphatidylserine decarboxylation, suggesting the existence of different intramembrane pools of phosphatidylethanolamine, which may exhibit different sensitivity to alcohol. 6. Our results indicate that ethanol exerts two different effects on phospholipid metabolism in hepatocytes: a stimulatory effect on the incorporation of exogenous substrates into different phospholipids probably related to an alteration in the availability of lipogenic substrates as a consequence of ethanol metabolism, and another inhibitory effect produced by ethanol per se, which can be observed only when ethanol metabolism is inhibited by the presence of a specific inhibitor of alcohol dehydrogenase activity.

Alcohol Dehydrogenase↗
PubMed1996

Responses of leptin to short-term fasting and refeeding in humans: a link with ketogenesis but not ketones themselves.

We investigated the response of leptin to short-term fasting and refeeding in humans. A mild decline in subcutaneous adipocyte ob gene mRNA and a marked fall in serum leptin were observed after 36 and 60 h of fasting. The dynamics of the leptin decline and rise were further substantiated in a 6-day study consisting of a 36-h baseline period, followed by 36-h fast, and a subsequent refeeding with normal diet. Leptin began a steady decline from the baseline values after 12 h of fasting, reaching a nadir at 36 h. The subsequent restoration of normal food intake was associated with a prompt leptin rise and a return to baseline values 24 h later. When responses of leptin to fasting and refeeding were compared with that of glucose, insulin, fatty acids, and ketones, a reverse relationship between leptin and beta-OH-butyrate was found. Consequently, we tested whether the reciprocal responses represented a causal relationship between leptin and beta-OH-butyrate. Small amounts of infused glucose equal to the estimated contribution of gluconeogenesis, which was sufficient to prevent rise in ketogenesis, also prevented a fall in leptin. The infusion of beta-OH-butyrate to produce hyperketonemia of the same magnitude as after a 36-h fast had no effect on leptin. The study indicates that one of the adaptive physiological responses to fasting is a fall in serum leptin. Although the mediator that brings about this effect remains unknown, it appears to be neither insulin nor ketones.

3-Hydroxybutyric Acid↗
PubMed1996

[Endorectal echography. Its usefulness in the study of neoplasms of the rectum].

OBJECTIVE: To analyze prospectively the results of the first endorectal ultrasonographies performed at the Coloproctology Unit of the Hospital Mutua de Terrassa in patients with rectal tumors. METHODS: During the period between September 94 to June 95, 27 endorectal ultrasonographies were performed to patients with rectal tumors. The echographies were performed with a 360 degrees transducer. The ultrasound findings were compared to the histological results. RESULTS: Three patients were not treated surgically, and were excluded from the analysis. In addition, three patients with perianastomotic recurrence were excluded. Of the remaining 21 patients the level of penetration in the rectal wall was correctly identified in 17 (81%). The presence of metastatic nodes was correctly assessed in 19 of the 24 patients explored (78%). CONCLUSION: For the preoperative assessment of rectal tumors, endorectal ultrasonography offers a good accuracy even during the learning curve.

Adult↗
PubMed1995

Persistence of the effects of ethanol in vitro on the lipid order and enzyme activities of chick-liver membranes.

Results demonstrate for the first time that ethanol exerts two different effects on the lipid order of chick-liver mitochondria and microsomes: a fluidizing effect both in the core and at the surface of the membrane, which depends on its physical presence, and a rigidization of the surface of these membranes which occurs after its removal. In addition, and directly related to the reduction in fluidity produced in the membrane surface after ethanol removal, we have detected a persistent alteration in different enzyme activities involved in the hepatic mitochondrial and microsomal electron-transport systems. The persistence of the alterations in the lipid order and enzyme activities may result from a structural rearrangement of the lipid and protein components produced in the lipid bilayer surface when ethanol is no longer present in the membrane.

Animals↗
PubMed1995

[The endoscopic treatment of postcholecystectomy biliary leakage].

Although there is a decrease in the total number of complications observed on performance of laparoscopy cholecystectomy (LC) there does appear to be an increase in biliary tract lesions. Seven cases of postcholecystectomy biliary leakage treated with endoscopic methods are presented. These cases include 4 patients with leakage from the cystic canal stump and 3 with leakage from the common bile duct. In 5 cases the biliary tract lesion occurred following LC, 1 after conventional cholecystectomy and in 1 reconverted LP. CPRE identified the site of the leakage in the 7 patients and in 2 residual choledocholithiasis. In 5 cases treatment consisted in endoscopic papillotomy and placement of biliary endoprosthesis while only papillotomy was performed in 2 patients. In one of these cases CPRE was repeated and the sphincterotomy widened due to persistence of the leakage at 5 days, with the same finally closing at 15 days of the second CPRE. Closure of the biliary leakage was obtained in the other 6 cases in less than 72 hours post-CPRE. No complications secondary to the technique were observed. It was concluded that CPRE together with endoscopic papillotomy and placement of biliary prostheses is an effective and safe treatment for postcholecystectomy biliary leakages of the common bile duct or cystic duct.

Aged↗