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A Güemes

Publications and source records attributed to A Güemes.

16 recordsLinked to original sources
PubMed2006

Lipid peroxidation in ischemia-reperfusion oxidative injury of the graft preserved in Celsior and University of Wisconsin solutions on a pig pancreas transplantation model.

BACKGROUND: Graft pancreatitis (GP) is one the main technical problems associated with pancreas transplant (PT). It occurs in 20% of patients representing a risk factor for thrombosis and cause of graft loss. GP is related to oxidative effects from oxygen-derived free radicals (OFR) in ischemia-reperfusion injury. We evaluated lipid peroxidation by the OFR in the PT of pig organs preserved with either Celsior or Wisconsin solutions. METHODS: In Landrace pigs we performed 24 pancreas allografts, which were preserved 18 or 24 hours: 12 with Celsior solution (CS) and 12 with Wisconsin solution (UW). No immunosuppression was administered. The oxidative effects were determined by quantification of malondialdehyde (MDA) and 4-hydroxyalkenals (4-HDA) and of the carbonyl groups of proteins in our pancreatic tissue samples and measured at different times: (A) baseline in the donor, (B) after perfusion of the graft, (C) after the ischemia period, and (D) 30 minutes after ischemia-reperfusion of the graft. RESULTS: The MDA and 4-HDA values were similar in conditions A, B, and C, but showed an extraordinary increase after ischemia-reperfusion in D, among both the 18- or 24-hour preserved grafts and in the same proportion with CS and UW. The carbonyl groups of the proteins rose in conditions B and C (cold ischemia), but less so in state D (reperfusion). CONCLUSIONS: The oxidative injury of a pancreatic graft preserved for 18 or 24 hours occurs during reperfusion, with an extraordinary intensity, but similarly with CS and UW, an observation that may help to explain graft pancreatitis.

Adenosine↗
PubMed2006

Preservation of the liver graft with Celsior solution.

INTRODUCTION: We studied the evolution of the liver graft with preservation in Celsior (CS) compared with University of Wisconsin solution (UW). MATERIAL AND METHODS: A randomized prospective clinical study in 80 liver transplants (OLTs) from May 2001 to October 2003, compared CS (group I; n = 40) and UW (group II; n = 40). The characteristics of the donors were homogeneous, with no significant differences in 15 variables. CS was perfused with 4 L through the aorta, 2 L through the portal vein, and 1 L, through the portal vein on the back table; and the UW, as 3 L, 2 L, and 1 L, respectively. All OLTs were performed using the piggyback technique. RESULTS: Group I experienced reperfusion syndrome (n = 2; 5.9%), primary graft nonfunction (n = 0); vascular complications (n = 0); biliary anastomosis stenosis (n = 8; 22.9%), intensive care unit (ICU) days (n = 4.1 +/- 1), death within 30 days (n = 1; 3.1%). The patient and graft survivals at 1, 3, 6, 12, and 24 months were 93.7%, 93.7%, 90.2%, 85.7%, 85.7%, and 94.3%, 88.5%, 85.2%, 78%, 78%, respectively. For group II; the reperfusion syndrome occured in 6 patients (17.6%); primary graft nonfunction (n = 0); vascular complications (n = 0), biliary anastomosis stenosis (n = 3; 8.6%), ICU days (n = 4.9 +/- 2.4) and death within 30 days (n = 1; 3.1%); The patient and graft survival at 1, 3, 6, 12, and 24 months were 96.9%, 93.5%, 89.8%, 79.8%, 79.8% and 94.3%, 88.3%, 84.9%, 75.5%, 66.1%, respectively. CONCLUSIONS: CS offers the similar safety to UW for preservation of liver grafts within these ischemia times.

Adenosine↗
PubMed2006

Liver transplant, in emergency 0 (UNOS Status 1).

INTRODUCTION: The emergency 0 (UNOS status 1) liver transplant (OLT) constitutes a challenge to the transplant team. The precarious condition of the patient and the use, sometimes forced by the instability of the patients, of marginal or different blood type grafts leads to worse results than in nonemergency OLT. Herein we have presented our experience with emergency 0 OLT in the first 5 years of our program. PATIENTS AND METHODS: Among the 167 OLTs performed in the first 5 years of our program, 10 were emergency 0 OLTs. The patients were transplanted within 72 hours of inclusion on the waiting list, seven within 24 hours. The indications for emergency OLT were fulminant liver failure (FLF) in six and graft failure in the first week post-OLT in four. RESULTS: All OLTs were performed with preservation of the vena cava (piggyback) and without venovenous bypass. There was 100% patient survival of those who required an emergency 0 OLT (follow-up period of 3 to 7 years). The graft survival in FLF was 50%. Emergency retransplant was necessary because of acute rejection due to ABO incompatibility in two patients, and due to arterial ischemia in another patient. The emergency retransplants were all successful. CONCLUSION: In our experience the emergency 0 OLT is a formidable challenge for the team, but we achieved a patient survival comparable to or even better than that of OLT for chronic liver disease.

Emergencies↗
PubMed2005

Prognostic factors in maxillary sinus and nasal cavity carcinoma.

AIMS: The aim of the present study is to define prognostic factors, particularly the impact of treatment on paranasal sinus and nasal cavity malignancies. MATERIAL AND METHODS: Retrospective study of patients with maxillary antrum and nasal fossae malignancies. A maxillectomy classification as performed to treat malignancies in our institution is described. Multivariate analysis of prognostic factors was done using the Cox's model. RESULTS: One hundred and nine patients were evaluated. Squamous cell carcinoma was found in 62 cases and in 95 patients the epicentre of the tumour was located in the maxillary antrum. Ten patients were treated with surgery only, 39 patients with surgery and adjuvant radiation therapy, 37 cases received only radiotherapy, and 18 received radiotherapy followed by surgery; in five cases a combination of chemo-radiotherapy was used. Multivariate analysis identified T classification, orbit invasion, N classification, site of origin of tumour in nasal fossae, and no surgical resection as independent prognostic factors (p=0.0001). CONCLUSION: T4 tumours with orbit invasion present bad prognosis as compared to other T4 tumours. Surgical resection should be included in the treatment strategy. Because of the high frequency of lymph-node metastasis, neck treatment should be considered in T4 tumours.

Adenocarcinoma↗
PubMed2002

Apoptosis and CD8 and CD54 cell expression in rat small bowel transplantation.

The importance of activated CD8 cells expressing IL-2R in small bowel and other organ rejection has been reported. Some authors even consider that a positive correlation might be demonstrated between the number of apoptotic enterocytes and the degree of graft rejection. In addition, moderate to intense activation of endothelial molecules in small bowel allograft in rats has been reported in chronic rejection. The aim of the present paper is to ascertain, in a heterotopic small bowel transplantation (HSBT) in rats, whether CD3, CD4, CD8, and CD54 cell expression in the allograft infiltrates shows some relationship with allograft enterocyte apoptosis when rejection is present. Wistar Furth male rats were allotted to two groups: group A was the control group without transplantation; group B received a heterotopic small bowel allograft from Fisher rats and an im dose of FK506 (0.25 mg/kg/day). A significant increase of CD8, CD54 cell receptor expression, and apoptosis in the group undergoing HSBT showed rejection. No significant differences have been observed in the variables under study between the control and HSBT without rejection groups or in CD3 and CD4 among the three groups. We observed a significant correlation between apoptosis and rejection, between CD8 and CD54 with apoptosis and with rejection, and between CD8 and CD54. This indicates that the activation of endothelial molecules and cells may play an important role in established HSBT chronic rejection. We consider that this study may contribute to the knowledge of small bowel allograft chronic rejection and its immunomodulation.

Animals↗
PubMed2000

Autologous blood transfusion as an immunomodulator in experimental sepsis.

BACKGROUND: Homologous blood transfusion is associated with immunosuppressive consequences. Some clinical and experimental studies have suggested an immunostimulating action of autologous blood transfusion. The aim of this paper is to ascertain the effects of either homologous blood transfusion or autologous blood transfusion on the lymphocyte subsets and cytokines in a model of intra-abdominal sepsis. MATERIALS AND METHODS: There were three study groups. Group A: 10 Wistar-Furth (WF) rats underwent cecal ligation and puncture (CLP) aimed at causing an intra-abdomial sepsis; Group B: 10 WF rats underwent CLP plus 1 ml homologous blood perioperative transfusion obtained from Fisher-344 rat while Group C: 10 WF rats underwent CLP plus 1 ml autologous blood perioperative transfusion. Changes of peripheral lymphocyte subsets, percentages of total T-lymphocytes (CD3), Helper T-lymphocytes (CD4), supressor/cytotoxic T-lymphocytes (CD8), CD4/CD8 ratio, Interleukin-2 receptor expression (IL-2R) and cytokines IL-1 and TNF-alpha were measured in peripheral blood on the preoperative, 1st, 3rd and 7th postsepsis (PO) days. RESULTS: Rats in homologous transfused group showed a decrease of %CD4 on the 3rd PO (from preoperative to 3rd PO;p < 0.01; and from 1st to 3rd PO; p < 0.05) and on the 7th PO (from preoperative to 7th PO; p < 0.05); %CD8 increased from preoperative to 3rd PO (p < 0.05), from 1st to 3rd PO (p < 0.01) and from 1st to 7th PO (p < 0.05). An initial decrease on day 1 (p < 0.01) followed by an increase on the 3rd PO (p < 0.01) with regard to IL-2R and a significant increase of IL-1 levels within the first 24h (p < 0.01). Rats in autologous transfused group showed an increase of %CD3 from preoperative to 7th PO (p < 0.05), and from 3rd to 7th PO (p < 0.01). CONCLUSIONS: We observed that homologous blood transfusions induce a greater alteration in the cellular immune response and of the cascade of cytokines than autologous transfusions. This modulates the variations of the immune response induced by sepsis.

Animals↗
PubMed1999

Hepatic lesion ablation with bipolar saline-enhanced radiofrequency in the audible spectrum.

RATIONALE AND OBJECTIVES: The authors' purpose was to create larger and more regular liver lesions in vitro by testing a new hyperthermia approach that uses a bipolar saline-enhanced electrode for radiofrequency (RF) in the audible spectrum and a greater power supply. MATERIALS AND METHODS: The authors' hyperthermia approach (group A, n = 23) was used in excised porcine livers, and the results were compared with those of a previously described monopolar saline-enhanced electrode procedure (group B, n = 23). In each set of experiments, RF in the audible spectrum current (50 Hz) was provided for 15 minutes with a similar ablation protocol. Electrical variables (impedance, current, voltage, power, and energy), temperatures in the lesions, volume size, regularity ratio of the lesion, and microscopic findings were measured. RESULTS: In group A, the mean volume size and the mean regularity ratio values were 144.8 cm3 +/- 59.8 and 0.78 +/- 0.1, respectively. In group B, the mean volume size and regularity ratio values were 62.1 cm3 +/- 36.4 and 0.62 +/- 0.1, respectively. The values in group B were thus significantly lower than those in group A (P < .01). The lesions in group A were also more homogeneous. No significant differences were found in electrical variables. CONCLUSION: The new bipolar saline-enhanced electrode produced larger, more regular, and more homogeneous lesions ex vivo than the previously used monopolar saline-enhanced electrode method. Using a greater power supply increased the amount of coagulative necrosis.

Animals↗
PubMed1999

Primary hydatid disease in lumbar muscles.

The authors report a case of primary hydatid disease in the lumbar muscles of a 40-year-old male patient. The rarity of this disease in our regions and the low incidence of this location make primary diagnosis difficult. The tumor had been treated elsewhere five years previously by means of simple excision. Recurrence of the lesion was diagnosed five years after the first surgery. Wide excision of the cyst and pericyst with a 3.5-cm security margin was performed. Six years after the last surgery, no recurrence has been detected.

Adult↗
PubMed1996

Changes in blood lymphocyte populations in experimental bowel allograft rejection.

The aim of this study is to measure percentages of lymphocyte populations and IL-2R cellular expression in peripheral blood during the rejection of a small bowel allograft (SBA) in the rat. Thirty rats were allotted to three groups: A, control, no transplantation (Tx); B, rats receiving an orthotopic SBA; C, similar SBA but with thymostimulin (TP-1) administered before Tx, aimed at increasing the intensity of and accelerating rejection. The percentages of CD19, CD5, CD4 and CD8 cells and of IL-2R were determined when rejection was present. Rejection appeared in rats in group B between days 11 and 26 post-Tx and in group C between days 6 and 7 post-Tx (P < 0.001). In both B and C groups, CD5 and CD4 cells decreased (P < 0.005) and CD8 cells increased (P < 0.001). A correlation between CD8 and IL-2R content was found (P < 0.05). In group C, earliness of rejection correlated with the percentage of CD8 cells (P < 0.05) and the intensity of rejection with numbers of CD8 and CD19 cells (P < 0.05).

Animals↗
PubMedDate not supplied

Immunorestorative effect of thymostimulin on surgery immunodepression: experimental model.

The purpose of the present study is to ascertain the immunorestorative effect of two different drugs on immunodepression induced by small bowel surgical resection in an experimental model. The potential immunorestorative effect has been measured by the ability of the drug to avoid the delay of skin allograft rejection induced by surgery and the inhibition of CD4/CD8 index changes induced by surgery in spleen tissue. 120 Wistar-Furth rats (age 12-16 weeks) anesthetized with a single intramuscular dose of ketamine (25 mg), diazepine (4 mg) and atropine (0.1 mg) were allotted to two main groups. One group received a skin graft (SG) from Fisher 344 rats and was treated with placebo, Inmunoferón (AM-3 polypeptidic drug) or TP-1 (thymostimulin) before the experiment (groups I, II, III) or treated with placebo, Inmunoferón or TP-1 before the experiment and underwent enterectomy and anastomosis (groups IV, V, VI). On the 2nd, 5th and 8th postoperative days, biopsies of the SG were taken and the signs of rejection were microscopically studied and evaluated by a pathologist as zero, incipient, moderate or massive. The other group was treated similarly, but the animals did not receive a SG and were splenectomized 5 days later. CD4 and CD8 lymphocyte subpopulations were identified by means of immunoperoxidase technique and monoclonal antibodies. Thymostimulin is able to stimulate the presence of SG rejection signs on the 2nd postoperative day in nonenterectomized animals and on the 8th postoperative day in nonenterectomized animals and on the 8th postoperative day in enterectomized rats and is able to avoid the decrease of the CD4/CD8 index in spleen tissue after surgical immunodepression.(ABSTRACT TRUNCATED AT 250 WORDS)

Adjuvants, Immunologic↗