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J Bueno

Publications and source records attributed to J Bueno.

At least 19 recordsLinked to original sources
PubMed2006

Melting curve of 4He: no sign of a supersolid transition down to 10 mK.

We have measured the melting curve of 4He in the temperature range from 10 to 400 mK with the accuracy of about 0.5 micro bar. Crystals of different quality show the expected T4 dependence in the range from 80 to 400 mK without any sign of the supersolid transition, and the coefficient is in excellent agreement with available data on the sound velocity in liquid 4He and on the Debye temperature of solid 4He. Below 80 mK, we have observed a small deviation from T4 dependence, which, however, cannot be attributed to the supersolid transition, because instead of decrease the entropy of the solid rather remains constant, about 2.5 x 10(-6) R.

Journal Article↗
PubMed2005

Adverse prognostic impact of CD36 and CD2 expression in adult de novo acute myeloid leukemia patients.

BACKGROUND AND OBJECTIVES: A consecutive series of acute myeloid leukemias (AML) patients was analyzed in conditions which reduce the inter-assay variations (the same flow cytometer, the same observers and the same panel of monoclonal antibodies) in order to investigate the prognostic information provided by flow cytometry. DESIGN AND METHODS: Two hundred and sixty-six bone marrow (BM) samples from 326 patients enrolled in the LMA-99 protocol from the CETLAM group were studied by multiparametric flow cytometry. Immunophenotyping studies were performed on erythrocyte-lysed BM samples. Antigen expression of leukemic cells was analyzed using triple stainings with fluorochrome-conjugated combinations of monoclonal antibodies. RESULTS: CD2 was positive in 21 cases (8%); an associated inv(16) was detected in eight CD2+ cases (38%). Two-year overall survival (OS) rate for CD2+/inv(16)+ patients was 75%, whereas it was 0% for CD2+/inv(16)- patients and 47% for CD2- patients (p=0.0001). CD36 was expressed in 37% of patients (n=98). Two-year leukemia-free survival (LFS) rate was 34% for CD36+ patients and 55% for CD36- patients (p=0.001). In the multivariate analysis, CD2+ (RR=8.4; p=0.0001) and adverse karyotype (RR=10.2; p=0.0001) were associated with a lower CR rate, CD36+ (RR=1.5; p=0.03), CD2+ (RR=2; p=0.04) and adverse karyotype (RR=4; p=0.0001) were associated with a lower OS and CD36+ (RR=2; p=0.002) and adverse karyotype (RR=3.5; p=0.005) predicted a lower LFS. CONCLUSIONS: CD2+ patients had a very poor OS when CD2/inv(16)+ cases were excluded. CD36 and CD2 expression at diagnosis can provide prognostically important information in adult de novo AML.

Acute Disease↗
PubMed2005

Analysis of discarded livers for transplantation.

The aims were to study the causes of nonacceptance of a liver for transplantation after exploration by the donor surgical team and to compare donor characteristics of transplanted and discarded livers. All donor harvesting procedures performed by our unit from 1988 to 2004 were retrospectively studied. Donors were divided in those accepted and transplanted and those discarded by the donor surgical team. The causes of rejection were classified as hepatic and nonhepatic. Donor characteristics of accepted, transplanted livers were compared with those rejected for hepatic reasons. Seven hundred fifty four donor liver procurements were performed: 628 livers were accepted and transplanted (TL), 126 (17.5%) were discarded owing to extrahepatic (n = 16) or hepatic causes (n = 110). Extrahepatic causes were: technical (5.6%), and incidental tumors infection (7.2%). Hepatic causes were: chronic disease or cirrhosis (26.4%), ischemic or septic liver (16.8%), and steatosis (44%). Univariate analysis of donor characteristics showed a significant difference in older age, diabetes, alcohol intake, arterial hypertension, abnormal liver ultrasound (US) exam, and abnormal liver function tests in the group of discarded livers. Obesity and the finding of steatosis in US exam were the only two factors that maintained statistical significance upon multivariate analysis.

Adult↗
PubMed2004

Thrombotic thrombocytopenic purpura and pregnancy: a review of ten cases.

BACKGROUND AND OBJECTIVES: A series of women with pregnancy-associated thrombotic thrombocytopenic purpura, is presented. This study will focus on the relationship between thrombotic thrombocytopenic purpura and pregnancy and on maternal and neonatal outcomes. MATERIALS AND METHODS: Among forty-six consecutive patients with thrombotic thrombocytopenic purpura, nine pregnant patients were identified. RESULTS: Seven patients presented an acute single episode associated with pregnancy and two patients had a chronic relapsing form of the disease. None of these two patients were diagnosed during pregnancy or in the postpartum period. There was one maternal death. Fetal mortality was 33%. CONCLUSIONS: The recurrence is rare in women who had the prior episode related to pregnancy. The risk of death for these patients seems not higher than that of the remaining patients in the series. Preterm delivery and intrauterine fetal death were frequent complications of these pregnancies.

Adolescent↗
PubMed2004

[Experimental model of auxiliary heterotopic liver-intestinal transplantation].

In pigs, orthotopic liver-intestine transplantation (LITX) has high per operative morbidity and mortality. It is due to hemodynamic, coagulation and metabolism disorders during native liver hepatectomy (total hepatic vascular exclusion) and the postoperative diarrhea secondary to initial dysfunction of the graft and enterectomy of native intestine. To avoid those disturbances and to increase the survival, we have developed a porcine model of auxiliary heterotopic LITX. The allograft was harvested in-bloc, containing the liver, duodenum, pancreas, and jejunum. In the recipient, the liver and intestine were left intact. The allograft was implanted heterotopically, caudal to the native liver. Venous drainage was achieved with anastomosis of donor (D) to recipient (R) infrahepatic cava; and arterialization with anastomosis of D aortic conduit containing the celiac axis and SMA to infra-renal R aorta. The D jejunum was hooked-up to R jejunum. The experiment was performed in 16 animals without intraoperative deaths, hemodynamic stability and no blood requirements. Four animals were left alive 7 days with functioning grafts, suggesting the model viability.

Animals↗
PubMed2003

[Success of endoscopic management in vesicoureteral reflux, conditioned by ureteral dilatation].

INTRODUCTION: Endoscopic management has become an important alternative in the treatment of vesicoureteral reflux in children. Since 1995 we indicate it in our Hospital in children with grade II VUR (vesicoureteral reflux) after 1 year of medical management, in all children with grade III VUR and in children with grade IV VUR without reflux nephropathy. According to International Classification of reflux (IRSC), grade IV VUR differ to grade III mainly by the blunting of the calyces and the obliteration of sharp angle of the fornices. There may be seen in the high grades of reflux, important differences in the ureteral dilatation. AIM: The aim of this work is to study the influence of ureteral dilatation in the success of endoscopic management VUR. MATERIAL AND METHODS: A number of 245 refluxing renal units (URR) were treated endoscopically in our Hospital from 1995. We review the first 3.5 years (58 patients with 90 RRU). In a double blind study with the voiding cystourethrographies we graduated the ureteral dilatation in slight-normal, moderate and severe. The success rate after the first injection was compared between the 3 grades of ureteral dilatation. RESULTS: 3 patients had grade I VUR, 10 grade II, 54 grade III and 23 grade IV. After double blind study 39 patients had slight-normal ureteral dilatation, 39 moderate and 12 severe. There were statistical differences between the 3 grades of ureteral dilatation when we consider: all the patients, considering only grade III and IV reflux and studying only the patients with grade III reflux. However there wasn't statistical differences between grade III and IV VUR of the International Classification. CONCLUSIONS: The results show that ureteral dilatation is an important prognostical factor of the success rate in the endoscopic management of vesicoureteral reflux in children.

Child↗
PubMed2002

Two groups of chronic myelomonocytic leukaemia: myelodysplastic and myeloproliferative. Prognostic implications in a series of a single center.

The clinical records of 70 patients seen at our hospital between 1976 and 1998 and diagnosed as suffering from chronic myelomonocytic leukaemia (CMML) were reviewed in order to confirm the validity of the classification into two forms of disease that the French-American-British Co-operative Leukaemia Group (FAB) proposed in 1994: myelodysplastic (MD) and myeloproliferative (MP), depending on the peripheral white blood cell count (WBC) (less or more than 13 x 10(9)/l, respectively). After the rejection of incomplete records and lost to follow up patients, our study population consisted of 49 records. Our results confirm that, even though this classification is useful in order to separate two classes of patients, it is not enough to predict the prognosis in an accurate manner. A lot of studies have tried to find some prognostic factors, but the results have been discordant. The multivariate analysis of our group of patients showed three prognostic factors: serum lactate dehydrogenase (LDH) >1.5 times normal level, blasts in bone marrow >5%, and peripheral blood leukocytes >10 x 10(9)/l. A second multivariate analysis led us to distinguish two groups: high risk (2-3 risk factors) and low risk (0-1 risk factors) (median survival 7 and 44 months, respectively) with a very high statistic significance (P<0.0001). This score should be applied to other series of CMML patients in order to confirm its validity.

Adult↗
PubMed2002

CsA-based post-graft immunosuppression: the main factor for improving outcome of allografted patients with acquired aplastic anemia. A retrospective survey by the Spanish Group of Hematopoietic Transplantation.

A retrospective multicenter study was performed to assess the clinical results in patients with acquired aplastic anemia (AA) allografted over a 19 year period and to identify prognostic factors influencing survival. From April 1978 to December 1997, 176 patients were transplanted. Records from 160 receiving related matched bone marrow transplantation (BMT) were reviewed. Fifty-two percent of the patients were older than 20 years, 5% older than 40; 6.3% were untransfused at BMT and 56.2% had received prior treatments. Conditioning regimens were with chemotherapy in 43.7% of the procedures and with additional irradiation in 56.3%. Graft-versus-host disease (GVHD) prophylaxis was based on cyclosporin A (CsA) in 58.1% of the patients while methotrexate (MTX) was administered to 41.9%. Transplantation earlier on, a longer interval from diagnosis to BMT, GVHD prophylaxis with MTX, graft failure/rejection and acute severe GVHD were adverse factors for survival. The use of CsA emerged as the main factor for the improvement, inducing a significant decrease in graft failure/rejection rate and severe acute GVHD when compared with MTX alone. Radiation-containing regimens decreased the graft failure/rejection rate without improving survival due to the increased risk of acute GVHD. Age and number of transfusions pretransplant did not influence outcome. Survival achieved since 1991 is 79.79%, and graft failure and acute severe GVHD rates are 6.0% and 11.8%, respectively. In conclusion, CsA-based post-graft immunosuppression has been crucial in achieving improved survival in patients with acquired AA up to 40 years of age. Regardless of CsA use, further improvement in survival was apparent with time, probably due to better skills in patient care.

Adolescent↗
PubMed2002

[Comparison of efficacy and complications of 27G and 29G Sprottte needles for subarachnoid anesthesia].

OBJECTIVE: Post-dural puncture headache and lumbar backache are related to needle gauge and type of point used. We aimed to determine whether the incidence of post-dural puncture headache and lumbar backache could be reduced by using fine gauge pencil-point Sprotte 27G and 29G needles. We also studied increases in technical difficulty with these needles and whether or not reducing needle gauge affected anesthetic quality. PATIENTS AND METHOD: Three hundred eighty-nine patients undergoing orthopedic or lower abdominal surgery were randomly assigned to two groups for dural puncture using two Sprotte needles: 27G or 29G. We recorded time to perform puncture, number of re-insertations of the needle, number of times the technique was abandoned and anesthetic efficacy. On the second and seventh days, the patients were interviewed by telephone to check for the presence and severity of post-dural puncture headache or lumbar backache. RESULTS: The technical difficulty was greater with the Sprotte 29G needle, as shown by significant differences in time taken to perform the puncture and the number of re-insertions (p < 0.05). Anesthetic quality was the same in both groups and the percentage of failures was 0.5% for both. Five percent of patients in the 27G group and 3% in the 29G group experienced slight or moderate headache on the second day. No cases of severe cephalea were reported. Lumbar backache was reported on the second day by 26% and 18.5% of the patients in the 27G and 29G groups, respectively, but the rates decreased to 4.5% and 0.5% on the seventh day. The differences were significant, favoring the 29G needle. CONCLUSIONS: The use of 29G pencil-point needles can be recommended to reduce the incidence of headache and lumbar backache in the postoperative period, in spite of the greater technical difficulty involved, given that quality of anesthesia is maintained.

Adult↗
PubMed2001

Results of simultaneous and sequential pediatric liver and kidney transplantation.

BACKGROUND: The indications for simultaneous and sequential pediatric liver (LTx) and kidney (KTx) transplantation have not been well defined. We herein report the results of our experience with these procedures in children with end-stage liver disease and/or subsequent end-stage renal disease. PATIENTS AND METHODS: Between 1984 and 1995, 12 LTx recipients received 15 kidney allografts. Eight simultaneous and seven sequential LTx/KTx were performed. There were six males and six females, with a mean age of 10.9 years (1.5-23.7). One of the eight simultaneous LTx/KTx was part of a multivisceral allograft. Five KTx were performed at varied intervals after successful LTx, one KTx was performed after a previous simultaneous LTx/KTx, and one KTx was performed after previous sequential LTx/KTx. Immunosuppression was with tacrolimus or cyclosporine and steroids. Indications for LTx were oxalosis (four), congenital hepatic fibrosis (two), cystinosis (one), polycystic liver disease (one), A-1-A deficiency (one), Total Parenteral Nutrition (TPN)-related (one), cryptogenic cirrhosis (one), and hepatoblastoma (one). Indications for KTx were oxalosis (four), drug-induced (four), polycystic kidney disease (three), cystinosis (one), and glomerulonephritis (1). RESULTS: With a mean follow-up of 58 months (0.9-130), the overall patient survival rate was 58% (7/12). One-year and 5-year actuarial patient survival rates were 66% and 58%, respectively. Patient survival rates at 1 year after KTx according to United Network of Organ Sharing (liver) status were 100% for status 3, 50% for status 2, and 0% for status 1. The overall renal allograft survival rate was 47%. Actuarial renal allograft survival rates were 53% at 1 and 5 years. The overall hepatic allograft survival rate was equivalent to the overall patient survival rate (58%). Six of seven surviving patients have normal renal allograft function, and one patient has moderate chronic allograft nephropathy. All surviving patients have normal hepatic allograft function. Six (86%) of seven sequentially transplanted kidneys developed acute cellular rejection compared with only two (25%) of eight simultaneously transplanted kidneys (P<0.04). CONCLUSIONS: Simultaneously transplanted kidneys were less likely to develop rejection than sequentially transplanted kidneys in this series. This did not have any bearing on patient or graft survival rates. Mortality correlated directly with the severity of United Network of Organ Sharing status at the time of kidney transplantation. Candidates for simultaneous or sequential LTx/KTx should be prioritized based on medical stability to optimize distribution of scarce renal allografts.

Adolescent↗
PubMed2001

Analysis of patients with longitudinal intestinal lengthening procedure referred for intestinal transplantation.

BACKGROUND/PURPOSE: Longitudinal intestinal lengthening procedures (LILP) in patients with short gut syndrome (SGS) enhances small intestinal peristalsis and decreases bacterial overgrowth without reducing absorptive surface. Therefore, patients theoretically may be easily weaned off TPN. The aim of this study was to evaluate the impact of failed LILP in SGS patients referred for intestinal transplantation. METHODS: Twenty-seven (11%) of 230 children with SGS and total parenteral nutrition (TPN) dependency evaluated for intestinal transplantation at our institution had undergone LILP. This was performed at a mean age of 1.7 years (range, 1 day to 14.7 years); the mean age at the time of evaluation was 3.3 years (range, 0.4 to 17 years). Two patients underwent LILP immediately after birth. The principle diagnoses producing SGS were gastroschisis (n = 8), intestinal atresia (n = 11), neonatal volvulus (n = 7) and necrotizing enterocolitis (n = 1). Before LILP, the mean length of intestine was 32 cm (range, 8 to 70 cm). Fifteen (56%) patients had jaundice at the time of evaluation. RESULTS: All but one child were considered candidates for intestinal transplantation. The mean intestinal length achieved after LILP was 48 cm (range, 16 to 100). The mean follow-up from the date of LILP was 876 days (range, 109 to 4,109 days). After LILP, only 9 (33%) patients increased their caloric intake through the enteral route by > or =50%, and only 1 patient could be weaned off TPN. In the patients with liver dysfunction at the time of LILP, none recovered. Most of the patients had multiple episodes of sepsis after LILP. Fourteen (52%) of 27 patients underwent intestinal transplantation, 7 combined with a liver allograft because of TPN-induced end-stage liver disease. Six of the transplanted patients are alive and TPN free. Of the remaining 13 (48%) nontransplanted patients, 9 patients died. The main cause of death was TPN-induced liver failure. Three patients are on partial TPN, and only 1 patient was weaned off TPN. The presence of an ileocecal valve did not impact on outcome. Surprisingly, patients with > or =50% of colon at the time of LILP had poorer survival than those with less. Twelve (44%) of 27 patients had surgical complications, and in both patients with LILP performed in the neonatal period it failed immediately with acute complications. There were no differences in patient survival rate for patients with SGS without LILP (n = 203) and those with LILP (n = 27). CONCLUSION: Based on patients with unsuccessful LILP referred for intestinal transplantation, we believe this procedure should be avoided in the neonatal period, in those patients with liver dysfunction, and when intestinal length is <50 cm.

Adolescent↗
PubMed2000

Predictive negative value of persistent low Epstein-Barr virus viral load after intestinal transplantation in children.

BACKGROUND: The correlation between an elevated Epstein-Barr virus (EBV) viral load in the peripheral blood and the subsequent development of EBV-associated posttransplant lymphoproliferative disease (PTLD) is the basis for strategies using serial measurements of the EBV viral load to guide preemptive therapy (PT). Neither the frequency, duration of monitoring, nor the predictive negative value of viral load monitoring for asymptomatic patients with persistent low or nondetectable viral loads against the development of PTLD has been established. METHODS: Since April 1994, children undergoing intestinal transplantation (ITx) underwent serial monitoring of the EBV viral load in their peripheral blood using a quantitative competitive EBV polymerase chain reaction assay (PCR). Samples were obtained every 2 weeks for the first 3 months and then every 1-3 months depending on the patients clinical condition. EBV viral loads > or =40 (for patients who were EBV seronegative pre-ITx) and > or =200 (for those who were seropositive) genome copies/10(5) peripheral blood lymphocytes were felt to identify patients at increased risk for PTLD and generally prompted PT. RESULTS: A total of 30 ITx recipients were compliant with our monitoring protocol; 23/30 are alive 6-59 months post-ITx. A total of 12/30 never had a viral load >40 and did not receive PT. In contrast, 18/30 had > or =1 high viral load (> or =200); the first high viral load was measured a median of 59 days post-ITx (range 1-440). A late rise (>6 months post-ITx) was seen in only 2/18 children. A total of 0/12 patients with persistently low viral loads received PT and none developed PTLD. In contrast, 5/18 with > or =1 one high viral load (including 2/14 who received and 3/4 who did not receive PT) developed PTLD. All five children with PTLD were EBV seropositive pre-ITx and experienced their first high EBV PCR within the first 3 months after ITx. CONCLUSIONS: The predictive negative value of persistently low or nondetectable EBV viral loads was 100% in this study. Patients with nondetectable or low viral loads for the first 6 months after ITx did not develop PTLD regardless of their pretransplant EBV serological status. The frequency of viral load monitoring can be safely decreased for patients whose viral loads remain low for the first 6 months ITx.

Antiviral Agents↗
PubMed2000

A simple scoring system to reduce intraabdominal septic complications after laparoscopic appendectomy.

BACKGROUND: The development of intraabdominal abscess (IAA) following laparoscopic appendectomy (LA) is associated with significant morbidity. The aim of the present study was to validate an IAA risk score constructed from a previous review of 156 consecutive LA. METHODS: The score was tested in 250 subsequent consecutive LA and in patients with a positive risk score. Broad-spectrum antibiotics were administered in order to avoid IAA. RESULTS: Factors related to IAA included clinically complicated appendicitis, leucocytosis >15,000/microl, a difference of >1 degrees C between axillary and rectal temperature, intraoperative findings such as (gangrenes and perforation), and intraoperative perforation of the appendix. In this series, broad-spectrum antibiotic therapy in patients with a positive IAA risk score reduced the incidence of IAA from 7.05% to 1.60%. CONCLUSION: This policy of identifying high-risk patient via the scoring system and instituting subsequent antibiotic therapy in patients at risk reduces the incidence of IAA following LA.

Abdominal Abscess↗
PubMed2000

Split-liver transplantation: a comparison of ex vivo and in situ techniques.

BACKGROUND/PURPOSE: The expanding applicability of liver transplantation as treatment for end-stage liver disease has fostered a disproportionate increase in liver transplant candidates in the face of an unchanging pool of donor organs. This has resulted in disparities in pretransplant waiting times and deaths. The splitting of a liver allograft allows for the transplantation of 2 recipients, usually an adult and a child, thus providing a means to expand the cadaveric donor pool. METHODS: The authors present their results on the performance of an ex vivo (back table) split and in situ (in a hemodynamically stable cadaveric donor) split to evaluate safety, applicability, and effectiveness. Between November 1989 through April 1998, 54 split-liver transplant recipient operations were performed (24 pediatric and 30 adult). Thirty donors were procured: the ex vivo splitting yielded 25 grafts from 13 donors (donor age, 24.6+/-11 years), and the in-situ technique yielded 29 grafts from 17 donors (mean donor age of 25.5+/-10.4 years). Five donors involved interinstitutional sharing for which the left side of the graft was kept at the host hospital and the right side grafts were utilized at our center. RESULTS: Overall 1-year patient survival was 85%, with a graft survival of 72%. Patient survival was similar with ex vivo (74%) as compared with the in situ splitting group (96%; P = .06), as was graft survival in ex vivo (61 %) versus in situ (81%) splitting (P = .15). The pediatric population benefited most from the in situ technique, with a 1-year patient survival rate of 100% with the in situ technique versus the ex vivo technique survival rate of 64% at 1 year (P = .02). The 1-year graft survival comparing these 2 techniques was 83% for the in situ group versus 45% for the ex vivo group. Analysis of the program evolution of split-liver transplantation suggested a time-dependent learning curve, which was applicable to surgical splitting technique, implantation, and recipient selection. CONCLUSIONS: The principle of splitting livers from cadaveric donors is fundamentally sound and technically feasible. The authors' outcomes analysis using 2 different procurement techniques suggests that the in situ technique is clinically efficacious, can be used alternatively with the ex vivo technique, and is comparable to whole-liver allograft transplantation.

Adult↗