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R Correa

Publications and source records attributed to R Correa.

At least 19 recordsLinked to original sources
PubMed2006

Improved survival with statins, angiotensin receptor blockers, and steroid weaning after heart transplantation.

Various immunosuppressive and adjunctive pharmacological regimens exist for cardiac transplantation, though the associations between these regimens and long-term survival are unclear. We reviewed demographic, clinical, and pharmacological data from 220 consecutive adult heart transplant recipients between 1986 and 2003 who survived beyond 3 months. Immunosuppression was cyclosporine-based (n=94) or tacrolimus-based (n=126), and 104 patients were weaned off steroids (all receiving tacrolimus). Covariates of mortality were assessed in a Cox proportional hazards analysis. The mean age was 5.2+/-13 years. Survival was 96%, 88%, and 81% at 1, 3, and 5 years, respectively. Significant covariates associated with mortality included pretransplant diabetes mellitus (hazard ratio [HR] 2.83, 95% confidence interval [CI] 1.45 to 5.04), black race (HR 1.41, 95% CI 1.01 to 1.94), higher pretransplant creatinine clearance (HR 0.99, 95% CI 0.98 to 1.00), steroid withdrawal (HR 0.60, 95% CI 0.39 to 0.85), and exposure to a statin (HR 0.53, 95% CI 0.40 to 0.70) or an angiotensin receptor blocker (HR 0.50, 95% CI 0.20 to 0.95) after transplantation. Treatment with a statin, an angiotensin receptor blocker, and steroid withdrawal were each associated with improved survival in heart transplant recipients. These findings warrant prospective study, with specific emphasis on identifying the clinical effects of these medications in transplant recipients.

Adrenal Cortex Hormones↗
PubMed2005

Development and efficiency of an acute knee trauma list.

Following acute knee trauma some patients will require urgent arthroscopy. Traditionally surgery is undertaken as in-patient on the general trauma list. This system leads to blockage of beds, repeated starving of the patient and out-of-hour's surgery in many cases. We introduced a dedicated Day Surgery knee trauma list (KTL) to reduce in-patient admissions, waiting time and cost. The typical indications for urgent knee arthroscopy are locked knees secondary to meniscal tears, loose bodies or cruciate ligament ruptures; acute osteochondral fractures; and children with acute meniscal tears. This retrospective review compares the study group: patients on the knee trauma list during the first 8 months following introduction, and the control group: patients on the general in-patient trauma list over a similar period immediately prior to implementation of the new list. There were 49 patients in the control group with an average stay in hospital of 2.5 days. Out-of-hour's operations were performed in 13 patients and 3 patients required a repeat arthroscopy. Fifty-three patients were treated in the knee study group. The significant operations were meniscal repair in 7, fixation of osteochondral fragments in 3. None of the patients required overnight stay. Control group patients were more likely to have surgery performed by inexperienced non-specialist knee surgeons, whereas specialist knee surgeons staffed the knee trauma list. Specialist surgeons were available to staff the knee trauma list. As the majority of the control group had spent an average of 2.2 nights in hospital, there has been considerable savings to the hospital. Introduction of the Day Surgical Knee trauma list has reduced unnecessary admissions per week; episodes of prolonged starving, cost and have improved patient satisfaction and management.

Adult↗
PubMed2005

Homeostatic role of IL-7 in HIV-1 infected children on HAART: association with immunological and virological parameters.

AIM: To investigate the role of IL-7 in HIV-infected children on highly active antiretroviral therapy (HAART) and its association with laboratory parameters related to disease progression. PATIENTS AND METHODS: A cross-sectional study in 31 vertically HIV-infected children (median age 8.4 y) treated with HAART, and a longitudinal study in four of those same children was carried out. In both studies, viral load, CD4+ T-cell counts, thymic production of T cells by TCR rearrangement excision circles (TRECs), IL-7 plasma levels and viral phenotype were determined. RESULTS: IL-7 levels were higher in HIV-infected children than in age-matched, uninfected controls. In addition, HIV children with CD4+ T cells between 200 and 500 T cells/mm3 had higher IL-7 levels and lower TREC values than HIV-infected children with CD4+ T cells >500 T cells/mm3. IL-7 levels were higher in children with syncytium-inducing (SI) phenotype than in those with non-syncytium-inducing (NSI) variants. During the follow-up of four HIV children, the decrease in viral load after HAART was always associated with a recovery of CD4+ T cells and TRECs, which was followed by a decrease in IL-7 returning to the levels present prior to the drop in CD4+ T cells. The four HIV-infected children had SI/X4 isolates in PBMC before HAART, and the viral phenotype switched to NSI/R5 after HAART. CONCLUSION: Our data suggest that IL-7 plays a key role in the maintenance of T-cell homeostasis in HIV-infected children on HAART, both through peripheral expansion and through a thymus-dependent mechanism.

Adolescent↗
PubMed2004

Can initial tacrolimus trough levels be predicted from clinical variables?

In eligible patients, cardiac transplantation has become the definitive treatment for end-stage heart failure. The initial posttransplantation course is marked by many potential difficulties, including renal insufficiency, hemodynamic instability, and perioperative bleeding. It is important to prevent early rejection; calcineurin inhibitors, such as tacrolimus or cyclosporine, are integral parts of such management. However, these drugs are associated with renal toxicity in some patients. Previous work suggests that limiting the increase in tacrolimus levels is associated with less renal insufficiency. The hypothesis of the current study was that a combination of clinical or laboratory variables could identify patients at risk for rapid changes in tacrolimus target levels. No single variable was strongly associated with high resultant trough levels following a standard 1-mg oral "test dose" of tacrolimus. However, the combination of 2 indices of liver metabolism (alanine aminotransferase and total bilirubin) along with serum creatinine did identify patients who tended toward elevated levels of tacrolimus (> or =4.5 ng/dL). Other variables, such as demographics, and even functional variables, such as right ventricular function by echocardiography, did not enhance the predictive value of this simple scoring system.

Adult↗
PubMed2004

Refractory humoral cardiac allograft rejection successfully treated with a single dose of rituximab.

Despite improvements in immunosuppression over the last two decades, the risk of allograft rejection is still high in the early postoperative period. Cellular rejection accounts for the majority of these episodes. However, humoral rejection is a distinct phenomenon that carries a high rate of graft loss and mortality. The currently available treatments for this serious clinical problem include anti-lymphocyte antibodies, immune globulin infusions, as well as plasmapheresis, all of which have limitations. We describe a case of refractory humoral cardiac rejection successfully treated with a single dose of rituximab (375 mg/m2). No further episodes occurred with 2 years of follow-up.

Adult↗
PubMed2003

Cardiac transplantation in the older recipient: excellent long-term survival based on pretransplant screening.

BACKGROUND: Cardiac transplantation has become the established treatment of choice for eligible patients with end-stage congestive heart failure. Older recipients (over the age of 60) are sometimes regarded as too high risk for transplant. Because chronological age is frequently disparate from physiologic age, we hypothesized that with careful selection after a comprehensive screening evaluation we would be able to achieve comparable survival and quality of life in an older population. METHODS: Between January 1989 and December 2002, 240 de novo adult cardiac transplants were performed for 74 female and 176 male patients. Prior to listing for cardiac transplantation, the patients were evaluated to exclude significant comorbidities that would limit survival or functional capacity postsurgery. In patients over the age of 60, particularly rigorous testing was conducted to eliminate significant extracardiac disease. RESULTS: The patients are divided in this analysis into three groups based on age at transplant (age 18 to 45, 46 to 59, and 60 years or older). Older recipients experienced similar rates of moderately severe cellular rejection (ISHLT grade 3A/ B). Survival as derived by Kaplan-Meier analysis was equivalent for all groups by Mantel-Cox logrank test (P = NS). The survival for patients older than age 60 was 83.1%, 73.7%, 67.7%, 57.4%, and 43.1% at 1,3, 5, 7, and 10 years posttransplant, respectively. CONCLUSION: We conclude that chronological age over 60 years old should not exclude a patient from the potential long-term benefit of cardiac transplant, ensuring added longevity and excellent quality of life.

Adolescent↗
PubMed2003

Preserved immune system in long-term asymptomatic vertically HIV-1 infected children.

The objective of this study was to study immune system status in long-term asymptomatic (LTA) HIV-1-infected children. A cross-sectional study was used, involving HIV-1-infected children over 7 years of age who were rated into two groups according to their clinical and immunological classification: (a) LTA: 7 asymptomatic HIV-1-infected children in A1; (b) Rapid progressor (RP): 14 age-matched C3 HIV-1-infected children. The control group consisted of 17 age-matched uninfected children. The characterization of CD4+ T-cell subsets was determined by three-colour flow cytometry. The proliferative response and cytokine production by activated peripheral blood T-cells were also measured. IL-7 levels were measured in serum. Thymic production of T-cells was quantified by TCR rearrangement excision circles (TRECs). The LTA children showed similar proliferative responses to PHA, PWM and anti-CD3+ anti-CD28, but lower responses to tetanus toxoid and streptokinase, in comparison with the controls but always higher responses in comparison with the RP group. The production of TNF-alpha and IFN-gamma was similar in the LTA and control groups, and both were higher than the levels in the RP group. The LTA group showed a lower percentage of memory CD4+ T-cells (CD4+ CD45RO+, CD4+ CD45RA-CD62L+) than the control and RP groups. The LTA group also showed lower percentages of CD4+ CD7- cells than the controls. As for naïve CD4+ T-cells (CD4+ CD45RA+ CD62L+), CD4+ CD45RA+ and CD4+ CD62L+ cells, the LTA group showed higher values than the control and RP groups. The LTA group showed higher percentages of CD4+ HLA-DR+ CD38+ than the controls, but lower values than the RP group. In contrast, the LTA group had percentages of CD4+ HLA-DR-CD38+ T-cells higher than both the control and RP groups, whereas CD4+ CD38+ levels were only higher in the LTA group in comparison with the controls. CD4+ HLA-DR+ CD38- and CD4+ HLA-DR+ cell numbers were lower in the LTA group in comparison with the RP group. We found almost normal values of TRECs and IL-7 in the LTA group, but lower values in the RP group. Moreover, we found an inverse relation between TREC levels and IL-7 in plasma from HIV-infected children. Asymptomatic HIV-1 infected children have a well preserved immune system similar to that of control uninfected children in spite of HIV-infection for more than 7 years. Moreover, our results identified new markers of HIV disease, such as TRECs and IL-7, that could be used to monitor disease.

Antiretroviral Therapy, Highly Active↗
PubMed2001

Viral phenotype affects the thymic production of new T cells in HIV-1-infected children.

OBJECTIVE: To determine whether viral phenotype has any effect on thymic production of new T cells in HIV-1-infected children. DESIGN: Differences in CD4+ T-cell counts and a marker of thymic output [T-cell antigen receptor (TCR) rearrangement excision circles (TRECs)], between HIV-1-infected children with non-syncytium-inducing (NSI) and syncytium-inducing (SI) viral strains were determined. PATIENTS AND METHODS: A cross-sectional study in 90 samples from vertically HIV-1-infected-children (median age 4.9 years) treated with combination therapy, and a longitudinal study in three children that underwent a change from NSI to SI phenotype were carried out. Viral load, viral phenotype, CD4+ T-cell counts, and quantification of TRECs values were determined. RESULTS: Children with SI virus showed significant lower levels of CD4+ T cells and a lower thymic production of new T cells than children with NSI. These reductions were independent of the treatment and the age of the children. However, there were no differences in viral load with the phenotype between those groups. In children with both NSI and SI viral phenotype, there was a significant correlation between CD4+ T-cell counts and TRECs values. CONCLUSION: The decrease of CD4+ T cells in presence of T-tropic viruses would be mainly due to a lower production of new CD4+ T cells as consequence of the inhibitory effect of these T-tropic strains on thymic function. This effect is not due either to the amount of circulating virus or to the replication kinetics of those strains, but rather depends on the ability of T-tropic viruses to infect T-cell precursors using CXCR4 receptors, which are highly expressed in immature thymocytes.

Anti-HIV Agents↗
PubMed2001

Tacrolimus monotherapy in adult cardiac transplant recipients: intermediate-term results.

BACKGROUND: Tacrolimus (FK506) is a macrolide antibiotic that inhibits T-cell activation and proliferation. To date, all published trials have used tacrolimus and steroids in combination with either azathioprine or mycophenolate mofetil. Previous experience with pediatric cardiac transplant patients at our institution suggested that use of tacrolimus alone provides an adequate level of immunosuppression and that withdrawal of steroids is readily achieved in most recipients. Between January 1, 1996, and July 7, 1999, we performed 77 adult cardiac transplants. Forty-three of these patients received tacrolimus and prednisone as primary immunosuppression, without azathioprine or mycophenolate mofetil. Thirty-two of the 43 patients started on tacrolimus have been weaned off steroids and are maintained on monotherapy. These latter patients form the basis of this report. The mean time for achieving monotherapy was 246 +/- 127 days (range, 106 to 730). Grade > or = 2 rejection occurred at 0.40 episodes per patient in the first 90 days (a combination of Grades 2 and 3A/3B rejections). The freedom from treated rejection (includes all 3A/3B and Grade 2 rejection in the first 90 days) was 69% at 90 days and 52% at 1 year. One patient (of 32) had documented cytomegalovirus infection (gastritis) diagnosed at 8 months post-transplant. We observed 1 case of transplant vasculopathy and 1 case of post-transplant lymphoproliferative disorder during the follow-up period. Our results show that use of tacrolimus alone after steroid weaning provides effective immunosuppression with low incidence of rejection, cytomegalovirus infection, transplant arteriopathy, or post-transplant lymphoproliferative disease.

Adult↗
PubMed2001

Compliance with postoperative instructions: a telephone survey of 750 day surgery patients.

Patients undergoing day surgical procedures are given postoperative instructions not to drink alcohol, drive vehicles or make important decisions for 24 h. They are also advised to have a responsible adult stay with them at home overnight. Seven hundred and fifty patients were telephoned at 24 h postoperatively to determine their compliance with these instructions. Four per cent of patients drove vehicles, 1.8% consumed alcohol, while one patient made an important decision. A higher proportion of patients (5%) drove after general anaesthesia than regional anaesthesia or intravenous sedation (2.4%). The percentage of patients consuming alcohol was similar in both groups (1.8% vs. 1.9%). Four per cent of patients had no one staying with them overnight despite being accompanied out of the hospital. Patient compliance with instructions to not drink alcohol, drive or make important decisions may be improved by physician reinforcement of instructions and patient education.

Aged↗
PubMed2001

Post-operative recovery: day surgery patients' preferences.

Due to the growing importance of quality assurance and cost containment in healthcare, eliciting patients' preferences for post-operative outcomes may be a more economical and reliable method of assessing quality. Three hundred and fifty-five day surgery patients completed a pre-operative written questionnaire to identify patients' preferences for avoiding 10 particular post-operative symptoms: pain, nausea, vomiting, disorientation, shivering, sore throat, drowsiness, gagging on the tracheal tube, thirst and a normal outcome. The two scoring methods used to evaluate preferences were priority ranking and relative value scores. The effects of age, gender, previous health status, type of surgery and previous experience of anaesthesia on patients' preferences were also examined. Avoiding post-operative pain, gagging on the tracheal tube and nausea and vomiting are major priorities for day-case patients. Anaesthetists should take patients' preferences into consideration when developing guidelines and planning anaesthetic care.

Adolescent↗
PubMed2001

Molecular determinants of peptide binding to two common rhesus macaque major histocompatibility complex class II molecules.

Major histocompatibility complex class II molecules encoded by two common rhesus macaque alleles Mamu-DRB1*0406 and Mamu-DRB*w201 have been purified, and quantitative binding assays have been established. The structural requirements for peptide binding to each molecule were characterized by testing panels of single-substitution analogs of the two previously defined epitopes HIV Env242 (Mamu-DRB1*0406 restricted) and HIV Env482 (Mamu-DRB*w201 restricted). Anchor positions of both macaque DR molecules were spaced following a position 1 (P1), P4, P6, P7, and P9 pattern. The specific binding motif associated with each molecule was distinct, but largely overlapping, and was based on crucial roles of aromatic and/or hydrophobic residues at P1, P6, and P9. Based on these results, a tentative Mamu class II DR supermotif was defined. This pattern is remarkably similar to a previously defined human HLA-DR supermotif. Similarities in binding motifs between human HLA and macaque Mamu-DR molecules were further illustrated by testing a panel of more than 60 different single-substitution analogs of the HLA-DR-restricted HA 307-319 epitope for binding to Mamu-DRB*w201 and HLA-DRB1*0101. The Mamu-DRB1*0406 and -DRB*w201 binding capacity of a set of 311 overlapping peptides spanning the entire simian immunodeficiency virus (SIV) genome was also evaluated. Ten peptides capable of binding both molecules were identified, together with 19 DRB1*0406 and 43 DRB*w201 selective binders. The Mamu-DR supermotif was found to be present in about 75% of the good binders and in 50% of peptides binding with intermediate affinity but only in approximately 25% of the peptides which did not bind either Mamu class II molecule. Finally, using flow cytometric detection of antigen-induced intracellular gamma interferon, we identify a new CD4(+) T-lymphocyte epitope encoded within the Rev protein of SIV.

Amino Acid Sequence↗
PubMed2000

Changes in macrophage and lymphocyte functions in guinea-pigs after different amounts of vitamin E ingestion.

Vitamin E is the main biological lipid-soluble antioxidant and plays a crucial role in the maintenance of the immune system. In the present work, twenty-one guinea-pigs (3-weeks-old) were distributed into three groups, which during 5 weeks ingested different amounts of vitamin E (/kg diet): 15 mg (low vitamin E diet), 150 mg (medium vitamin E diet; control) or 1500 mg (high vitamin E diet). The function of lymphocytes and macrophages were then studied. In macrophages obtained from the peritoneum several steps of the phagocytic process (chemotaxis, ingestion and superoxide anion production) were assayed, as well as chemotaxis and proliferation of peritoneal and spleen lymphocytes. The results indicate that with respect to the medium vitamin E diet, low ingestion of vitamin E causes a decrease in chemotaxis and production of superoxide anion by macrophages and an increase in the phagocytic capacity. With the high vitamin E diet an increase in macrophage and lymphocyte chemotaxis, superoxide anion production and lymphoproliferative capacity, as well as a decrease in phagocytosis, were observed. Therefore, diet supplementation with higher than usual levels of vitamin E appears to be beneficial for the immune system.

Animals↗
PubMed1999

Changes in several functions of murine peritoneal macrophages by N-acetylcysteine and thioproline ingestion. Comparative effect between two strains of mice.

The administration of the thiol compounds, N-acetylcysteine (NAC) and in particular thioproline (thiazolidine-4-carboxylic acid) at 0.1% w/w concentration in the diet, improves lymphocyte functions in old female Swiss mice, as has been shown in our previous studies. In the present work, adult mice from two different strains, namely BALB/c (an inbred strain) and OF1-Swiss (noninbred strain), were fed a diet supplemented with the above dose of each thiol compound jointly for five weeks. At 28 weeks of age, peritoneal cell suspensions were obtained and different steps of the phagocytic process, the most representative activity of macrophages, as well as interleukin-1beta (IL-1beta) production, were studied. Thus, adherence to substrate, mobility directed to a chemoattractant gradient (chemotaxis), ingestion of inert particles and superoxide anion production were analysed. The results show that diet supplementation with NAC plus thioproline increased all macrophage functions studied with the exception of superoxide anion production, which was decreased. These effects were more evident in macrophages from Swiss mice, whereas in BALB/c mice the stimulation of phagocytosis and IL-1beta production was lower and no differences were seen after treatment in adherence and superoxide anion production. These data suggest that immune function can be improved in adult mice by administration of the above thiol compounds, especially in the noninbred strain of OF1-Swiss mice.

Acetylcysteine↗