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Biomedical subjects

J Quiroga

Publications and source records attributed to J Quiroga.

At least 37 records · Page 2Linked to original sources
PubMed2001

Influence of tumor characteristics on the outcome of liver transplantation among patients with liver cirrhosis and hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) may recur after liver transplantation (LT), mainly in patients with multinodular and large tumors. However, factors predictive of outcome after LT in patients with small tumors remain ill defined. We investigated which factors were related to mortality or tumor recurrence among 47 liver transplant recipients with liver cirrhosis and HCC and compared them with 107 patients with liver cirrhosis without tumor who underwent LT in the same period. Patients with HCC were older (P <.001), more frequently had cirrhosis of a viral origin (P <.001), and had lower Child-Pugh scores (P <.001) than patients without tumor. Survival of patients with and without tumor was not significantly different (P =.20). Among patients with HCC, those with lower recurrence-free survival rates had liver cirrhosis of a viral origin, vascular invasion, bilobar disease, and tumor-node-metastasis (TNM) stage IV. At multivariate analysis, the only factor associated with mortality or recurrence was TNM stage IV (P =.02). Our results suggest that in patients with HCC and TNM stage IV, LT might be contraindicated.

Adult↗
PubMed2001

Mobile technologies in the management of disasters: the results of a telemedicine solution.

Nowadays a great number of applications are used to compile and transmit casualties and disasters information but there are many troubles associated with the technology as can be the communications reliability and the size and weight of the devices medical staff has to carry with. Telecommunication infrastructures support information movement among geographically dispersed locations. Recently a large family of little devices has appeared in the buyer's market. They are called Personal Digital Assistants and because of their physic and technical features, they are very useful in the emergency field. As for the communications reliability, many technologies have been developed in the last years but it is necessary to find a solution that can be used in whatever situation independently of the emergency circumstances. Facing this reality, the Spanish government funded REMAF, an ATYCA (Initiative of Support for the Technology, Security and Quality in the Industry) project. REMAF joined research groups (UPM), phone operators (Fundación Airtel Móvil) and end users (SAMUR) to build a disaster data management system conceived to use modern telemedicine systems to optimize the management in these situations, taking the advantage of the above mentioned mobile communication tools and networks.

Disasters↗
PubMed2000

Insulin-like growth factor-I reverts testicular atrophy in rats with advanced cirrhosis.

The pathogenesis of hypogonadism in cirrhosis is not completely understood. The levels of insulin-like growth factor-I (IGF-I), an anabolic factor with trophic actions on testes, are reduced in cirrhosis. This study was undertaken to evaluate whether rats with advanced cirrhosis develop hypogonadism and whether the administration of IGF-I exerts beneficial effects on testicular structure and function. Wistar rats with ascitic cirrhosis induced with CCl(4) were allocated into 2 groups (n = 10, each) to receive recombinant IGF-I (20 microg x kg(-1) x d(-1), subcutaneously) or vehicle for 3 weeks. Healthy rats receiving vehicle were used as the control group (n = 10). At baseline, both cirrhotic groups showed similar deterioration of liver function tests. Compared with controls, nontreated cirrhotic rats showed decreased serum levels of IGF-I (P <.05), reduced testicular size and weight (P <.001), and intense histopathological testicular abnormalities, including reduced tubular diameters (P <.001), loss of the germinal line (P <. 001), and diminutions in cellular proliferation, spermatogenesis (P <.001), and testicular transferrin expression (P <.001). In addition, low serum testosterone (P <.01) and high serum LH (P <.01) were present in untreated cirrhotic animals. Cirrhotic rats that received IGF-I showed full recovery of testicular size and weight and of all histopathological abnormalities (P <.001 to <.01 vs. nontreated cirrhotic rats; P = ns vs. controls). Serum levels of sex hormones tended to normalize. In conclusion, IGF-I deficiency may play a pathogenetic role in hypogonadism of cirrhosis. Low doses of IGF-I for a short period of time revert testicular atrophy and appear to improve hypogonadism in advanced experimental cirrhosis.

Animals↗
PubMed2000

Hyperhomocysteinemia in liver transplant recipients: prevalence and multivariate analysis of predisposing factors.

Liver transplant recipients have an increased risk for cardiovascular disease because of a high incidence of obesity, arterial hypertension, diabetes mellitus, and hyperlipidemia. Hyperhomocysteinemia has been found to be an important risk factor for cardiovascular disease in large studies. Fasting serum levels of homocysteine were measured in 105 liver transplant recipients, and hyperhomocysteinemia was defined as a fasting serum homocysteine level greater than 13 micromol/L. Patients with versus without hyperhomocysteinemia were compared. The possible association of hyperhomocysteinemia with age, sex, cause of liver disease, time elapsed since liver transplantation, immunosuppressive therapy, folic acid level, liver function test results, renal function, and other cardiovascular risk factors was investigated. Patients with serum homocysteine levels greater than 15 micromol/L were treated with folic acid, 10 mg/d, and serum homocysteine levels were measured again 1 to 3 months later in 10 patients. Hyperhomocysteinemia was detected in 28 patients (27%). In univariate analysis, it was associated with hepatitis C virus infection, treatment with mycophenolate mofetil, and greater serum levels of alkaline phosphatase, gamma-glutamyl transpeptidase, urea, and creatinine. In multivariate analysis, only greater serum levels of creatinine (P =.006) were associated with hyperhomocysteinemia. Treatment with folic acid resulted in a decrease in fasting serum homocysteine levels in 9 of the 10 patients tested (P =.01). Hyperhomocystinemia, associated with renal dysfunction, is a frequent finding in liver transplant recipients. Treatment with folic acid may reduce fasting homocysteine levels.

Creatinine↗
PubMed2000

Weak and strong hydrogen-bonding patterns in the structure of 2, 4-bis(2-hydroxybenzoyl)-2,3-dihydro-1H-pyrido

The title compound, C(25)H(19)NO(4)S, (IV), was produced by a cyclocondensation reaction similar to that which had previously produced an unexpected product, thus giving a novel route for such reactions. The structure of (IV) contains two S(6) motifs formed by strong intramolecular O-H.O hydrogen bonds. Weak C-H.O hydrogen bonds form primary C(11), R(1)(2)(7) and R(2)(2)(8) motifs which combine to form a complex three-dimensional network.

Journal Article↗
PubMed2000

Altered intestinal transport of amino acids in cirrhotic rats: the effect of insulin-like growth factor-I.

The intestine is an important target organ for insulin-like growth factor-I (IGF-I), an anabolic hormone synthesized in the liver upon growth hormone (GH) stimulation. Levels of IGF-I are reduced in cirrhosis, and altered GH/IGF-I axis may contribute to malnutrition in cirrhotic patients. Our aim was to study Na(+)-dependent jejunal transport of amino acids (L-leucine, L-proline, L-glutamic acid, and L-cysteine) in cirrhotic rats and to analyze the effect of IGF-I on this function. IGF-I or saline was administered for 2 wk to rats with CCl(4)-induced cirrhosis and saline was administered to healthy control rats. Transport of amino acids was assessed in brush-border membrane vesicles (BBMV) using (14)C- or (35)S-labeled amino acids, and the kinetic constants V(max) and K(t) were determined. Na(+)-independent uptake of L-leucine, L-proline, L-glutamic acid, and L-cysteine by BBMV was similar in all groups. Na(+)-dependent uptake of all four amino acids was significantly diminished in cirrhotic rats compared with both controls and IGF-I-treated cirrhotic rats. The latter two groups exhibited similar V(max) and K(t), whereas untreated cirrhotic rats had reduced V(max) and increased K(t) compared with normal controls and IGF-I-treated cirrhotic animals. In conclusion, the transport of all four tested amino acids by BBMV is impaired in cirrhotic rats, and low doses of IGF-I can correct this defect.

Amino Acids↗
PubMed2000

Aortic valve replacement with bioprostheses in liver transplant recipients.

Three cases of aortic valve replacement with porcine bioprostheses are reported in liver transplant recipients at two to six years after transplantation. Indications for aortic valve replacement (AVR) were aortic stenosis (n = 2) and aortic regurgitation (n = 1). The use of bioprostheses was recommended because of patient age, the need for multiple liver biopsies, and contraindication to the use of anticoagulation therapy. The patient who underwent AVR because of aortic regurgitation developed structural valve deterioration (SVD) during the next five years after surgery, and thus replacement of the bioprosthetic valve was required. Recipients of liver transplant who undergo valve replacement with tissue valves should be carefully followed up because of the risk of early SVD. AVR may be performed safely after liver transplantation.

Adult↗
PubMed1999

Conversion of liver transplant recipients on cyclosporine with renal impairment to mycophenolate mofetil.

The management of liver transplant recipients with renal function impairment remains controversial because cyclosporine withdrawal from triple immunosuppression regimens may be followed by graft rejection. A nonnephrotoxic and powerful immunosuppressant such as mycophenolate mofetil (MMF) could allow a reduction of cyclosporine dosage or its withdrawal and an improvement in renal function in these patients. Eleven patients with serum creatinine levels greater than 1.5 mg/dL, normal graft function, and a rejection-free period of at least 1 year started MMF at a dose of 2000 mg/d (reduced in case of adverse events) while cyclosporine dosage was slowly reduced. At last follow-up (63 +/- 5 weeks), 7 patients remained free of cyclosporine (6 of those patients are also free of steroids), 2 patients reduced their cyclosporine dose, and 2 patients developed mild acute rejection that responded to a switch to tacrolimus therapy. Serum creatinine and urea levels in the 7 patients free of cyclosporine decreased from 2.22 +/- 0.13 to 1.90 +/- 0.19 mg/dL (P =.05) and 0.95 +/- 0.10 to 0.60 +/- 0.10 g/L (P <.001), respectively. Creatinine clearance increased from 38.16 +/- 5.60 to 47.01 +/- 6. 76 mL/min (P =.005). Control of arterial hypertension also improved. Tolerance to MMF was good, but 6 patients required dose reductions, mainly because of asymptomatic anemia. In conclusion, in liver transplant recipients with stable graft function, MMF may allow cyclosporine dose reduction or discontinuation, thus improving renal function and the control of arterial hypertension. This change of treatment must be carefully monitored because of the frequent need for MMF dose reduction and the risk for rejection.

Aged↗
PubMed1999

Effect of insulin-like growth factor I on in vivo intestinal absorption of D-galactose in cirrhotic rats.

Insulin-like growth factor I (IGF-I) bioavailability is reduced in liver cirrhosis, a condition frequently associated with malnutrition. We have analyzed in vivo absorption of D-galactose by jejunal loops in rats with CCl4-induced liver cirrhosis and the influence of IGF-I on intestinal sugar transport in this disease. Two different study protocols were followed. In protocol 1, healthy control rats or cirrhotic rats received saline or IGF-I (2 micrograms . 100 g body wt-1. day-1) for 2 wk. In protocol 2, control and cirrhotic rats received saline or IGF-I as a bolus injection of 1 microgram/100 g body wt followed by continuous infusion of the same dose for 100 min. In vivo D-galactose absorption was reduced in cirrhotic rats compared with healthy controls. IGF-I, as both a chronic (protocol 1) and acute treatment (protocol 2), was able to improve sugar transport in cirrhotic rats but had no effect on sugar absorption in healthy rats. A significant elongation of enterocyte microvilli was observed in cirrhotic animals; this alteration was totally or partially corrected by chronic or acute IGF-I administration. Our results show that in vivo jejunal sugar transport and microvilli structure are altered in liver cirrhosis and that IGF-I, among other effects, may correct these changes by modulating cytoskeletal organization in enterocytes.

Animals↗
PubMed1998

Risk factors for recurrence of hepatitis C after liver transplantation.

Recurrent hepatitis C is a frequent complication after liver transplantation for hepatitis C virus-related cirrhosis, but risk factors related to its development remain ill defined. Twenty-three patients receiving a primary liver graft for hepatitis C virus-related cirrhosis and with an assessable biopsy performed at least 6 months after liver transplantation were studied retrospectively. The end point of this study was to look for risk factors associated with the development of histologic hepatitis C in the graft. Thirty-six major variables were studied, and those reaching significance by univariate analysis were included in a multivariate analysis. Eighteen patients (78%) developed posttransplant hepatitis C. On univariate analysis, six variables showed significant predictive value: increased immunosuppression for treatment of acute rejection; pretransplant hepatocellular carcinoma; cumulative doses of prednisone at 3, 6, and 12 months after transplantation; and mean blood trough levels of cyclosporine in the first 6 months posttransplantation. On multivariate analysis, two variables retained independent statistical significance as predictors of hepatitis C recurrence, namely receipt of antirejection therapy (P = .0087) and lower mean cyclosporine levels in the first 6 months after transplantation (P = .0134). Therefore, recurrence of hepatitis C after liver transplantation seems to be at least partially related to posttransplantation immunosuppressive therapy.

Adult↗
PubMed1998

Circulating adrenomedullin in cirrhosis: relationship to hyperdynamic circulation.

BACKGROUND/AIMS: Peripheral arterial vasodilation may be the key factor in the sodium and water retention of cirrhosis. The mechanism responsible for this vasodilation remains to be fully elucidated. Adrenomedullin is a novel peptide, highly expressed in cardiovascular tissues, with potent and long-lasting vasodilating activity. METHODS: The possible implication of adrenomedullin in the hemodynamic changes of cirrhosis has been investigated. We measured the plasma concentration of adrenomedullin in 20 cirrhotic patients and 11 healthy subjects. In addition, systemic, portal and renal hemodynamics, hormonal factors and renal function parameters were evaluated in the same patients. RESULTS: Circulating adrenomedullin was significantly higher in the group of patients with cirrhosis (72.1; 46-100 vs 21.6; 11-34 fmol/dl, respectively; p<0.02) and was directly correlated with the Pugh score (r: 0.6; p: 0.01), inversely correlated with the creatinine clearance (r: -0.6; p<0.01) and tended to inversely correlate with systemic vascular resistance index (r: -0.46; p: 0.07). There were no portal-peripheral differences in adrenomedullin levels. Transjugular intrahepatic portosystemic shunt insertion did not induce changes in the peripheral concentration of adrenomedullin, but baseline values of this hormone predicted the degree of hyperdynamic circulation after TIPS. CONCLUSIONS: Circulating adrenomedullin is increased in cirrhosis. These levels increase with the severity of the disease, especially in patients with hepatorenal syndrome. This peptide may contribute to vasodilation of cirrhosis.

Adrenomedullin↗
PubMed1998

Osteopenia in rats with liver cirrhosis: beneficial effects of IGF-I treatment.

BACKGROUND/AIMS: Liver cirrhosis is associated with osteopenia and also with low levels of IGF-I. This hormone has been reported to stimulate bone formation in states of undernutrition and low bone turnover. Our aims were to evaluate whether osteopenia develops in male Wistar rats with CCl4-induced cirrhosis and whether IGF-I is effective in the restoration of bone mass in these animals. METHODS: Cirrhotic rats were distributed into two groups: group CI (n = 12) which received placebo and group CI + IGF (n = 12) which was treated with human recombinant IGF-I (2 microg/100 g bw/day, s.c., 21 days). Twelve normal animals which received placebo constituted the control group. On the 22nd day, the animals were sacrificed, and bone parameters were analyzed in femur and/or tibia. RESULTS: Posterior-anterior and latero-medial diameters were similar in all groups. Also, no significant differences were observed in bone contents of calcium, total proteins, collagen and hydroxyapatite in CI rats as compared with controls. However, CI rats showed significant reductions in bone weight (-13.5%, p < 0.001), total bone density (-9.28%, p < 0.001), and increased perimedullar bone resorption and urinary levels of deoxypyridinoline (a marker of bone resorption). In CI + IGF rats these parameters improved significantly as compared with CI animals. CONCLUSIONS: Osteopenia characterized by loss of bone mass and preserved bone composition is found in rats with CCl4-induced cirrhosis. This bone disorder is partially corrected by treatment with low doses of IGF-I. Since osteoporosis seems to be the predominant form of osteopenia in patients with cirrhosis, IGF-I should be considered as a possible therapy for this disorder.

Alanine Transaminase↗
PubMed1998

Concurrent clarithromycin and cyclosporin A treatment.

Although macrolides have been associated with significant pharmacokinetic interactions, clarithromycin is considered to have a low interaction capacity. In this study, six transplant recipients treated with cyclosporin A also received clarithromycin. In all patients, the dose of cyclosporin A had to be reduced by a mean of 33% per day depending on the macrolide dose. Normalization of the dosage parameters began on the fourth day after stopping clarithromycin treatment. Co-administration of cyclosporin A and clarithromycin may lead to increases in whole blood cyclosporin levels, and appropriate dose reductions should be considered.

Anti-Bacterial Agents↗
PubMed1998

Liver transplantation in cirrhotic patients over 60 years of age.

Although life expectancy in Spain is above seventy years, age over sixty is considered a relative contraindication for liver transplantation (LT) in most centers. The aim of this study was to assess the outcome of LT in patients over sixty years of age comparing them to patients under that age. From January 1992 to August 1995, 61 cirrhotic patients underwent LT at our institution; of them, 43 (group I) were younger than 60 years (mean +/- SEM: 51.9 +/- 0.9 years, range: 37-59) and 18 patients (group II) were 60 years or older (64.1 +/- 0.7, range: 60-71). Main pre-transplant variables (sex, etiology of liver disease, presence of hepatocarcinoma, Child-Pugh's score and renal function) were similar in both groups. The follow-up (median and range) for group I was 28 and 3-47 months, and for group II 16.5 and 3-48 months. Actuarial survival rates at one and four years post-LT were respectively 88.3% and 85.6% for group I, and 87.8% and 87.8% for the group II (p = n.s.). There were no differences between both groups regarding the incidence of rejection, major infections, neurologic complications, renal failure, pathological bone fractures, diabetes mellitus or hypertension. Nevertheless, cardiovascular complications were significantly more frequent in group II (p = 0.002) although they were not the cause of death. In conclusion, our results show that the outcome of LT in patients over sixty years old is comparable to that observed in patients under that age. LT should not be contraindicated on the only basis of an age greater than 60 years.

Adult↗