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P Ruiz

Publications and source records attributed to P Ruiz.

At least 37 records · Page 2Linked to original sources
PubMed2005

Multifactorial snowball effect in the reduction of refusals for organ procurement.

Interviewing the family of a possible organ donor is a legal requirement in Spain, but it is the stage at which most potential donors are lost. Multiple factors influence the family's acceptance or rejection of this option, including awareness of the wishes of the deceased, personal preconceived attitudes of family members, as well as issues related to the hospital and its health care personnel, whose attitudes are a key factor in obtaining permission. We examined all 651 donation situations in a single hospital that included a family interview over the last 15 years. Among these 651 cases, 191 families refused donation (29.3%). The rate of donation refusal has fallen from 46.3% to 12.5% over these 15 years. To better understand the evolution of donor characteristics, interviewees, and the setting, we divided the sample into three 5-year periods to analyze key variables collected from the family interviews. The results showed that at the same time as the donor profile has changed, namely, fewer brain trauma cases and more victims of stroke as well as older mean age and more coexistent diseases, these has been an improvement in the factors related to the information and opinion of both the families and the donor about this process. The main reasons for refusal of donation have changed from negation of brain death, religious factors, and the desire to maintain the body intact during the 1990s, to sociocultural reasons in minority ethnic groups, to presumed refusal during life, and to family disagreements during the more recent years.

Adolescent↗
PubMed2005

The importance of clinical parameters when differentiating cholestatic hepatitis C virus from allograft rejection.

BACKGROUND: The exact cause and appropriate treatment for cholestasis following liver transplantation in recipients with hepatitis C virus recurrence (RHCV) are difficult to determine. Our objective was to determine the diagnostic accuracy of clinical and histological parameters in liver transplant recipients with RHCV and concurrent cholestasis. METHODS: A retrospective analysis from June 1996 to May 2003 was performed on adult liver transplant (OLT) recipients with hepatitis C virus. Patients with cholestasis (bilirubin >5 mg/dL, 6 months after OLT) were selected. Demographics, etiology, immune suppression, clinical and histologic outcomes, and virologic features were evaluated. Patients were divided into two groups based on clinical and histological criteria: (1) patients with parameters suggestive of cholestatic HCV; and (2) patients with parameters consistent with acute cellular rejection. RESULTS: Thirty-seven patients met study criteria (20 males). The average age was 54 years (range = 14-72), and time from transplant to jaundice was 769 days (range = 48-2981). The groups were comparable regarding HCV viral load, age, gender, time from transplant, and United Network of Organ Sharing status at time of transplant. Retransplantation was performed in two patients in group 1, neither of whom survived, and in three patients in group 2, all of whom survived. Clinical parameters correlated well with diagnosis of cholestasis (r = 0.85, P < .001) whereas histological evaluation did not (r = 0.11, P = .53). Mortality in group 1 was 78% (7 of 9) vs. 50% (13 of 26) in group 2. Median duration of survival following liver transplantation in group 1 was 132 days versus 435 days in group 2. CONCLUSION: Clinical diagnosis parameters for RHCV with cholestasis appear more accurate than histology parameters and should be the primary consideration in directing therapy. Despite timely diagnosis, cholestatic RHCV LTx recipients have a poor prognosis.

Adult↗
PubMed2005

Pegylated interferon and ribavirin for the recurrence of chronic hepatitis C genotype 1 in transplant patients.

The efficacy of pegylated interferon (p-IFN) and ribavirin (RB) in transplant patients is not well known. Chronic hepatitis C evolves in a more aggressive form after transplantation, causing a worse survival. Twenty-one naïve patients with recurrent chronic hepatitis C demonstrated by biopsy were treated for 48 weeks with p-IFN alpha2b (1.5 microg/kg/wk) and RB (>10.6 mg/kg/d). Quantification of RNA was performed (Amplicor Cobas 2.0 Roche) at baseline, 4, 12, 24, 48, and 72 weeks. A qualitative technique was used when quantitative levels were undetectable. At more than 1 year since liver transplantation we did not detect coinfection with human immunodeficiency virus or use steroid treatment. Among the cohort there were 16 men (76.2%). The mean overall age was 52 +/- 12 years. Time from liver transplant to treatment was 1637 +/- 1030 days. They were all infected with genotype 1. Eight patients received cyclosporine and the others tacrolimus. One patient was coinfected with hepatitis B virus and was receiving lamivudine. The mean initial histological activity index was 6.9 +/- 1.5 and fibrosis, 2.52 +/- 1.8 (Ishak). Two patients needed spleen embolization before the treatment. Two patients had to stop the treatment: one due to clinical intolerance, and the other one due to a cholangitis. In 14%, p-IFN doses were adjusted. In 32% RB was adjusted. Five (23.8%) did not respond at 24 weeks. Fourteen (66.7%) showed end-treatment responses but four relapsed at 72 weeks. A sustained viral response was achieved in 9 (42.8%). One patient died due to arterial thrombosis just after completing the treatment.

Adult↗
PubMed2004

Trends in serum citrulline and acute rejection among recipients of small bowel transplants.

A test for detecting acute cellular rejection (ACR) of small intestinal transplants (ITx) would be a major advance. Small preliminary studies suggest that serum citrulline levels correlate with ACR. The results for a group of 26 isolated intestinal and multivisceral transplant recipients are summarized here. Serum citrulline concentrations were determined by ion exchange chromatography and compared to biopsy-based grade of ACR. Other factors considered included patient and donor age and sex, ischemia time, and serum creatinine. Straight-line fits were employed to describe how each patient's citrulline levels changed over time. Estimated times to achieve normal citrulline (>or=30 micromol/L) ranged from 1 to 730 days posttransplant for 21 patients demonstrating increasing citrulline levels over time. Using stepwise linear regression, patients' ranks for time required to achieve normal citrulline levels were the only independent predictors of both maximum ACR (P <.0001) and average ACR (P =.0059) after 14 days posttransplant. The rate and direction of change in citrulline over time may be an indicator of the risk of acute rejection. We plan to further examine the use of citrulline as a marker for rejection in larger prospective studies.

Adult↗
PubMed2004

Viral interleukin-10 gene therapy to induce tolerance to solid organ transplants in mice.

In this study, a novel gene therapy approach to prolong allograft survival was designed. Autologous (syngeneic) hematopoietic stem cell-enriched bone marrow cells (HSC; lin(-)) engineered with the vIL-10 gene (vIL-10-HSC) were injected (4 to 6 x 10(6) cells, i.v.) into lethally (9.5 Gy) or sublethally (4 Gy) irradiated CBA/J mice 6 weeks prior to allogeneic heart (C57BL/6) transplantation (Tx). Cardiac allograft survival was significantly (P <.004) prolonged in lethally (71 +/- 40 days) and sublethally (114 +/- 15 days) irradiated mice that received vIL-10-HSC compared to controls that received no HSC (11 +/- 1 days), unengineered HSC, or vector-DNA-engineered HSC (12 to 16 days). Tolerant graft histopathology demonstrated mild arteritis/venulitis (grade 0.7) and rejection (grade 1.0). Intragraft expression of costimulatory molecules (B7.1, B7.2), cytokines (IL-2, IL-4, mIL-10, IFN-gamma), and iNOS molecules were markedly lower in tolerant grafts that survived for >100 days; recipient T lymphocytes demonstrated hyporeactivity to donor and third-party antigens in mixed lymphocyte cultures. These findings have important implications and potential therapeutic applications in transplantation and autoimmune diseases.

Animals↗
PubMed2004

Histological criteria for the identification of acute cellular rejection in human small bowel allografts: results of the pathology workshop at the VIII International Small Bowel Transplant Symposium.

Acute cellular rejection remains a serious and frequent complication during the posttransplant course of small bowel allograft recipients. Currently, small bowel biopsies are the optimal method to identify this form of rejection. The morphological criteria for this diagnosis have been known for some time; however, no consensus study has classified these changes. To address issues in bowel transplant pathology, several pathologists experienced in this particular subdiscipline participated in a Pathology Workshop preceding the VIIIth International Small Bowel Transplant Symposium in Miami, Florida. Among the results of this workshop was the development a standardized grading scheme for acute cellular rejection in small bowel transplants.

Biopsy↗
PubMed2004

Study of the development and evolution of neointestine in a rat model.

The implantation of fragmented rat intestinal epithelium into the omentum of syngeneic animals results in the formation of a cyst containing neointestine. The purpose of our project was to study the evolution of this neointestine-containing cyst over time. Harvested jejunum and ileum of neonatal DA rats (6 to 8 days old) was digested with collagenase type XI and dispase at room temperature. The resulting organoid units, containing clusters of intestinal epithelium with stem cells were seeded onto a polyglactin polymer mesh (100000 units per mesh). The absorbable mesh was implanted in the omentum or peritoneal wall of an adult syngeneic animal. Animals were sacrificed at weekly intervals to harvest the neointestinal cysts. The lumen of the neointestine cysts was full of mucous while the wall of the cyst was covered by intestinal mucosa. H&E staining of the cyst demonstrated the morphology of intestinal epithelium; PAS staining identified goblet cells. The size of the cyst was maximal between 4 and 8 weeks postimplantation tending to regress thereafter. Neointestinal cysts are a consistent finding after implantation of intestinal epithelium organoids into the omentum or peritoneal wall in the rat model. The cysts reach a maximal size at 4 to 8 weeks postimplantation, tending to regress thereafter.

Animals↗
PubMed2004

Immunoenzymatic and morphological detection of epithelial cell apoptotic stages in gastrointestinal allografts from multivisceral transplant patients.

Acute allograft rejection (AR) is a major contributor to morbidity and mortality among patients who undergo multivisceral transplantation. Critical to the assessment of AR is detection of apoptosis in the glandular epithelium of the gastrointestinal allograft. We utilized the TUNEL stain (TdT-mediated biotin 16-dUTP nick-end labeling) to test whether this method improved detection of apoptosis compared to standard slide evaluation. TUNEL and H&E stains were performed on paraffin-embedded tissue sections to estimate the number of apoptotic bodies per 10 high power fields, as determined by independent pathologists in blinded fashion. Both methodologies showed similar numbers and distributions of apoptotic foci present among the epithelial cells. There was a correlation between the number of apoptosis and the grade of rejection (P <.001). This is the first use of the TUNEL stain in gastrointestinal allograft biopsies to our knowledge. The similarity in pattern and sensitivity of TUNEL with standard morphology confirms that biopsy assessment with routine H&E staining allows an accurate appraisal of epithelial cell apoptosis. Therefore, current staining protocols for endoscopically derived mucosal biopsies of gastrointestinal allografts are sufficiently accurate to enumerate the critical feature of epithelial apoptosis as a determinant of the grade of acute rejection.

Apoptosis↗
PubMed2004

Lymphoplasmacytic hyperplasia (possibly pre-PTLD) has varied expression and appearance in intestinal transplant recipients receiving Campath immunosuppression.

Posttransplant lymphoproliferative disorders (PTLD) are a frequent complication in bowel transplant recipients. Histological changes in PTLD range from expansile lymphoplasmacytic (LP) hyperplasia to frank lymphoma. Small bowel allograft biopsies obtained in the first 250 days posttransplant were retrospectively graded after patients had received induction immunosuppression with either anti-CD52 (Campath) or anti-CD25 (Zenapax) monoclonal antibodies. The biopsies were analyzed with respect to the onset intensity of lymphoplasmacytic infiltrates and presence of in situ EBV hybridization (EBER) positivity. We observed that lymphoplasmacytic infiltrates were a frequent change in all bowel transplant patients over the examined period. Campath-treated patients developed earlier LP infiltrates of mild to moderate intensity between day 1 and 100 posttransplant, thereafter decreasing to mild. No EBER positivity was detected in this group. Zenapax-treated patients presented with LP infiltrates later of mild to moderate intensity through day 100 posttransplant. However, more persistent and intense LP infiltrates was observed after day 101 in this group, including a case of lymphoma and two cases of EBER positivity. We conclude that Campath immunosuppression results in an earlier appearance of LP lesions that are generally less intense than those evident with Zenapax. We attribute these findings to the more profound immunodeficiency and cell targeting following Campath treatment.

Alemtuzumab↗
PubMed2004

Campath-1H immunosuppressive therapy reduces incidence and intensity of acute rejection in intestinal and multivisceral transplantation.

Campath-1H, an anti-CD52 antibody, is being used at our institution as immunosuppression in multivisceral and intestinal transplantation. We reviewed the pathologic findings of 1696 small bowel allograft biopsies obtained in the first 250 days posttransplant from 78 patients who underwent isolated intestinal or multivisceral transplantation and received induction immunosuppression with Campath (n = 30) or Zenapax (n = 57). We found an overall reduced incidence of acute cellular rejection (ACR) in patients receiving Campath (19.1%) compared with those on Zenapax (32.8%). The majority of Campath patients showed no rejection or was indeterminate for rejection over the period of measurement. The frequencies of mild and moderate ACR were approximately twice and three times more common, respectively, in Zenapax-treated patients. The mean grade of ACR in Campath patients compared with Zenapax patients was significantly lower (P <.01) during the first 6 weeks posttransplant. Thereafter, the grade of rejection in both patient groups showed fluctuation, with Zenapax patients sometimes having lower values (eg, at 2 to 4 months) than Campath patients. Patient and graft survival was not significantly different between the two groups. These data suggest that the incidence of ACR is significantly reduced with Campath during the first 2 months posttransplant, when compared with Zenapax. However, the incidence and intensity of ACR following this initial time period shows vacillation with both types of immunosuppression.

Alemtuzumab↗
PubMed2004

Epithelial and hematopoietic cell chimerism in intestinal allografts.

BACKGROUND: In intestinal transplantation recipient lymphocytes infiltrate the allograft soon after reperfusion. Recently, it has been demonstrated that long-surviving small bowel transplants bear enterocytes of recipient origin. We investigated whether epithelial cells (enterocytes) persisted in long-term allografts based on studies of biopsies. METHODS: The biopsies of four male intestinal transplant recipients of female grafts with a previous graft biopsy positive for recipient enterocytes were examined at least 6 months after previous positive assessment. Using the FISH technique, we searched for Y-chromosome-positive enterocytes in the female allograft. RESULTS: Recipient male enterocytes were identified in all biopsies at low percentages ranging from 0.18 to 0.26. The lymphocytes within the graft were of both recipient (male) and donor (female) origin. CONCLUSION: The four types of cells-enterocytes and lymphocytes of recipient and donor origin-coexist in long-term graft biopsies.

Biopsy↗
PubMed2004

Rat enterocyte cultures on human amniotic membranes.

BACKGROUND: Rat enterocytes were cultured on human amniotic membranes. METHODS: Intestine of neonatal DA rats was digested using collagenase and dispase according to the technique developed by Evans. The harvested enterocytes were cultured on human amniotic membranes using standard cell culture techniques. RESULTS: After the second day of culture, some intestinal epithelial units started to gradually detach from the membrane, dispersing as single cells and disappearing within a few days. On the contrary, other units showed signs of cell proliferation. The cultured cells underwent morphologic changes, survived, and remained attached to the amniotic membrane for 3 weeks. Paraffin sections of the membrane showed cultured cytokeratin-positive cells attached to the membrane as a monolayer. CONCLUSIONS: Human amniotic cell membranes help to maintain rat enterocytes in culture for a long time period (3 weeks), possibly via secretion of trophic factors. This technique may provide a valuable tool to study the development and the properties of these epithelial cells in a culture environment.

Amnion↗
PubMed2004

The long-term effects of immune suppression on liver transplant recipients with recurrent hepatitis C viral infection.

INTRODUCTION: Adequate immune suppression following liver transplantation in recipients with recurrence of hepatitis C virus (HCV) is not standardized. The aim of this study was to evaluate the association between immune suppression protocol and the clinical/histological parameters in HCV transplant recipients with an HCV recurrence. METHODS: A retrospective analysis was performed on recipients of liver transplants from June 1998 to October 2003 who experienced HCV recurrence. Only patients with liver biopsies at 3 to 5 years following liver transplantation were included in the analysis. The data set included: patient demographics, immune suppression, antiviral therapies, as well as histology to evaluate ductopenia and chronic rejection. Patients divided into groups of high, medium, and low immune suppression were subdivided by treatment with versus without interferon. A control group with similar demographics suffering from cryptogenic cirrhosis was used for comparison. RESULTS: During this period 45 patients had liver biopsies at 3 to 5 years posttransplantation. Their mean age was 56.5 years and mean time from transplant to biopsy was 1543 days. Their average posttransplant survival was 1964 days. There was no difference among the three groups with respect to HCV RNA levels (log(10) IU/mL), age, gender, time from transplant, donor age, and UNOS status. Median HCV RNA levels within the three groups were comparable at various time periods pre- and posttransplant. CONCLUSION: The development of chronic allograft damage following transplantation in recipients with recurrent HCV tended to be worse among patients with low levels of immune suppression, suggesting the importance of therapy to maintain allograft function.

Antiviral Agents↗
PubMed2004

Activity of rifampin against Mycobacterium tuberculosis in a reference center.

Rifampin is a bactericidal antibiotic that acts both on extra- and intracellular bacilli. It inhibits RNA synthesis by binding to the beta-subunit in the RNA polymerase. A study was conducted on rifampin resistance from 1993 to 2002 with 1,794 Mycobacterium tuberculosis strains submitted to Mycobacteria Reference Center, Córdoba, Spain. A total of 1,460 of these strains came from pulmonary specimens and 235 from extrapulmonary specimens. All strains were identified by conventional morphological, bacteriological, biochemical, genetic, and chromatographic methods. For 99 strains, the source was not indicated. Initially, the BACTEC 460 TB system was used for antibiotic sensitivity testing. Since 1996, the ESP II system was also used. The strains ATCC27294 (sensitive to streptomycin, rifampin, ethambutol, and isoniazid) and ATCC38838 (resistant to rifampin) were used as controls. The resistance degree detected was 10.03%, of which 1.2% and 8.7% corresponded to primary and secondary resistances, respectively. A total of 137 strains showed multiresistance. The surveillance of resistance and of the potential factors that may lead to an increase in resistance is thus warranted.

Antibiotics, Antitubercular↗
PubMed2004

[Guidelines on hemodialysis-associated viral infections].

The viric infections influence morbi-mortality in Chronic kidney Disease patients in hemodialysis therapy and can affect to the Staff of the Units. The guides considered the most relevant virus at the present moment: C Virus, B Virus and HIV. To prevent horizontal nosocomial transmission is necessary the observance always the universal precautions in the HD units, although sometimes can appeared seroconversions and epidemic bud when exist a break of these. Is analyzed different situations with special focus in units for acute patients. The following steps under the suspicious of the epidemic bud appeared in one of the annexes together with legislation according to this case. Respect to the staff in every one of the virus is shown prevention patterns, serologic markers to perform when an accident with infected blood occur, also is considered when treatment is indicated. The guides considered too the conditions necessary for include these patients on waiting list for kidney transplantation.

Ambulatory Care Facilities↗
PubMed2003

Sclerosing mesenteritis in small bowel transplantation: possible manifestation of acute vascular rejection.

BACKGROUND: Acute rejection of human small bowel allografts is characterized by clinical symptoms combined with characteristic morphologic alterations. The typical geographic distribution of acute rejection in the bowel is involvement of the intestinal parenchyma, which can be transmural, particularly when the rejection is more severe. However, little is known concerning the potential for donor-derived soft tissue adjacent to the bowel to become involved by the host alloimmune response. METHODS: We describe a male patient who, several weeks after combined small bowel and liver transplantation, demonstrated sclerosing mesenteritis with vasculitis and acute rejection of the bowel. RESULTS: The vascular lesions in the mesentery demonstrated increased IgG deposition and the patient developed an alloantibody to the donor. CONCLUSIONS: The changes described herein may represent a novel presentation of acute vascular rejection.

Acute Disease↗