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Biomedical subjects

T Serrano

Publications and source records attributed to T Serrano.

At least 19 recordsLinked to original sources
PubMed2006

Kinetics of antibodies in sera, saliva, and urine samples from adult patients with primary or secondary dengue 3 virus infections.

OBJECTIVES: The kinetics of three serological markers (IgM, IgA, and IgG) in serum, saliva, and urine samples from adult patients with primary or secondary dengue infection were studied. DESIGN: Serum, saliva, and urine samples were collected from 22 patients with clinical and confirmed dengue 3 virus infection during the outbreak in Havana City in 2001. They were tested by capture IgM (MAC-ELISA), IgA (AAC-ELISA), and IgE (EAC-ELISA) and IgG ELISA inhibition method (EIM) to detect specific dengue antibodies. RESULTS: Similar kinetics were observed in IgM, IgA, and IgG antibodies in saliva and IgA and IgG in urine samples from secondary cases compared with kinetics in serum samples, although the values were lower. No IgG antibody was detected in saliva and urine samples in primary cases and IgM antibody was not detected in urine samples from either primary or secondary infection. All secondary cases were positive for IgG in saliva and urine samples at day 7. The kinetics of specific IgE antibodies in primary and secondary cases were different. CONCLUSIONS: The kinetics of three serological markers (IgM, IgA, and IgG) in serum, saliva, and urine samples from adult patients with primary or secondary dengue 3 virus infection were studied for the first time, showing its behavior and usefulness in dengue virus diagnosis. The specific IgE could play a role as a serological marker in secondary infections.

Adult↗
PubMed2005

Clinical and virological effects during two years of ongoing adefovir dipivoxil in the treatment of lamivudine-resistant chronic hepatitis B infection.

OBJECTIVE: Our aim was to evaluate the efficacy and safety of adding adefovir to lamivudine therapy for hepatitis B virus (HBV)-infected patients resistant to Ramivudine. PATIENTS AND METHODS: Among 17 studied patients, 7 had chronic active HBV infection and 10 were posttransplant with HBV infection (9 with de novo HBV). They received lamivudine plus adefovir therapy for 2 years. We assessed reductions in serum HBV-DNA and alanine aminotransferase (ALT) levels, loss of HBeAg (in HBeAg+ cases), and HBsAg clearance. RESULTS: A virological response, as defined by HBV-DNA below the cut off by hybridization, was observed in 12 (70.6%) patients and loss of HBeAg in 4 (44.4%) of the 9 initially HBeAg-positive cases. A biochemical response, defined as a decreased serum ALT to the normal range, occurred in 4 (26.7%) patients. Median serum creatinine increased in 3 of 15 (20%) patients, excluding those on hemodialysis. There were two noteworthy cases of sustained HBsAg seroconversion with adefovir (11.8%): one patient with de novo HBV infection posttransplantation and positive hepatitis C virus-RNA serology, and one patient with decompensated HBV cirrhosis in whom viral replication ceased, making him eligible for transplantation. CONCLUSIONS: Currently, adefovir is an effective rescue therapy that broadens the existing range of options for patients with lamivudine-resistant chronic hepatitis B infection, particularly those with decompensated cirrhosis awaiting a liver graft, and those with recurrent posttransplantation HBV. The relatively small biochemical response seen in these patients may be attributable to the high prevalence of concomitant hepatitis C virus infection (41%).

Adenine↗
PubMed2004

Serological markers during dengue 3 primary and secondary infections.

BACKGROUND: The detection of the IgM antibody for the dengue virus in serum by ELISA has become one of the most important and useful methods for diagnosis of dengue using a single acute-phase serum sample. Currently, this system is an invaluable tool for the surveillance of dengue fever (DF) and dengue hemorrhagic fever (DHF). The usefulness of other serological markers such as IgA and IgE have been less studied. OBJECTIVE: To study the IgM, IgA and IgE specific antibody response in dengue 3 infected patients with different clinical picture and type of infection. STUDY DESIGN: One hundred and twenty-seven serum samples collected on days 5-7 at the onset of fever from clinically and serologically confirmed dengue cases were studied. Forty-two were classified as primary dengue fever cases, 48 as secondary dengue fever cases and 37 as secondary dengue hemorrhagic fever cases. All samples were tested by capture ELISA in order to detect dengue IgM, IgA and IgE antibodies. RESULTS AND CONCLUSIONS: In this study, significant differences were observed in the IgM, IgA and IgE response between the study groups. High IgA and IgE OD ratios in secondary dengue cases were found. The usefulness of serotype specific IgM antibody detection is also analyzed and discussed. A priority for future dengue research in terms of protection, recovery of infection and immunopathogenesis is to elucidate the role of these immunoglobulins. The cross reactivity response to IgM between dengue virus serotypes in primary and secondary cases should also be more studied.

Antibodies, Viral↗
PubMed2001

A phase I clinical trial of a multi-epitope polypeptide TAB9 combined with Montanide ISA 720 adjuvant in non-HIV-1 infected human volunteers.

A phase I clinical trial was performed to examine the safety and immunogenicity of a multi-epitope polypeptide comprising the central 15 amino acids of the V3 loop from six HIV-1 isolates. This protein called TAB9 was emulsified in Montanide ISA720 (Seppic, Paris) and administered intramuscularly at doses of 0, 0.2 and 1 mg to 24 healthy, HIV-1 seronegative adult males. Three immunisations were given at months 0, 1 and 6 in a randomised, double blind, placebo controlled clinical trial. The placebo was generally well tolerated. However, severe local reactions were observed in TAB9 vaccinated subjects after the second and third inoculations. Seven out of eight volunteers from the lower dose group showed moderate or severe local inflammation, while four out of eight subjects from the higher dose group developed granulomas and sterile abscesses. In general, the reactogenicity depended on the number of inoculations given and the dose of TAB9. Both doses were immunogenic, all immunised volunteers seroconverted and antibodies were broadly reactive against the V3 peptides included in the protein. All vaccine's sera reacted against gp120 in Western blot and 50% of them also neutralised at least one out of five laboratory isolates tested. No differences between doses were found. Anti TAB9 lymphoproliferative responses were observed, being more intense in the high dose group. Due to the strong local reactions that were found in this study, a change in the formulation will be required for further trials with this vaccine candidate in humans.

AIDS Vaccines↗
PubMed2001

Heart and liver xenotransplantation under low-dose tacrolimus: graft survival after withdrawal of immunosuppression.

BACKGROUND: The hamster-to-rat xenotransplantation model is a useful model to investigate the features of extended host response to long-surviving xenografts. Early xenoantibody responses are T-cell independent and resistant to tacrolimus. Treatment with the combination of mofetil mycophenolate plus FK506 avoids acute xenograft rejection completely, but after withdrawal of immunosuppression hamster grafts are rejected by a process called late xenograft rejection (LXR). METHODS: Hamster hearts and livers were transplanted into Lewis rats. Grafted rats were treated with mofetil mycophenolate (25 mg/kg/day) for 8 days and FK506 (0.2 mg/kg/day) for 31 days. Serum IgM and IgG levels were determined by flow cytometry and interferon-gamma levels by ELISA. IgM, IgG, and C3 deposits were measured in tissue by immunofluorescence, and leukocyte infiltration was measured by immunoperoxidase staining. Results. Survival of heart and liver xenografts in the rats was 48+/-4 days and 63+/-8 days, respectively. After cessation of all immunosuppression, hearts were rejected in 18+/-4 days and livers in 33+/-8 days. Production sequences of xenoantibodies in the two organs differed substantially, especially 7 days after transplantation and at the moment of rejection. Quantification of interferon-gamma levels indicated that there were no significant changes after transplantation. Histological and immunohistochemical studies showed signs of humoral mechanism of LXR in rats undergoing heart transplantation and cellular mechanism of LXR in those that received a liver transplant. Conclusions. These observations suggest that rejection in the hamster-to-rat heart xenotransplantation model is mediated by a T cell-independent B-cell response to which a T cell-dependent B-cell response is added in LXR. In the liver xenotransplantation model, our hypothesis is that LXR is mediated by a mixed cell mechanism, involving lymphocytes CD4+ CD45RC+, macrophages, and cytotoxic T lymphocytes. In summary, we have demonstrated and compared the peculiar features of LXR in two different organs.

Animals↗
PubMed2001

Safety and preliminary immunogenicity of the recombinant outer membrane protein P64k of Neisseria meningitidis in human volunteers.

P64k is a meningococcal protein from Neisseria meningitidis that has been obtained by recombinant DNA technology. Recombinant P64k has been extensively characterized by physicochemical and immunological methods. Lately this protein has been found to act as a versatile immunological carrier for weak antigens in mice. In the present work, a Phase I clinical trial was carried out in healthy volunteers who received three inoculations of either placebo or recombinant P64k (20 or 50 microg). No severe adverse events occurred during the trial. Only mild adverse events in ten volunteers were observed. At 1 month after the third dose, 15 out of 18 volunteers (83.3%) who received the recombinant antigen had a P64k-specific antibody titre > or =1:100, as detected by ELISA. A fourth dose, given 9 months after the third one, elicited a potent booster immune response in P64k vaccinees. Accordingly, these P64k formulations were considered safe and immunogenic in healthy human volunteers.

Adult↗
PubMed2001

Postreperfusion biopsies are useful in predicting complications after liver transplantation.

Biliary complications after orthotopic liver transplantation (OLT) may occur because of preservation injury (PI). In this study, we examine findings on routine reperfusion biopsy specimens in relation to the occurrence of biliary complications and graft outcome. From 1997 to 2000, a total of 193 OLTs were performed in our center. Postreperfusion biopsy specimens were analyzed and histological lesions were graded. For analysis, grafts were grouped into 2 categories: the presence or absence of PI (severe to moderate lesions versus mild or no lesions). Histological evidence of PI was present in 17% of the biopsy specimens. The incidence of grafts with PI and ischemia time longer than 12 hours was 38% compared with 14% in PI and short ischemia time (P =.02). Biliary complications were also more frequent in the PI group (28% v 14%; P =.03). Study of risk factors by means of logistic regression analysis confirmed that the PI group had a greater risk for biliary complications (relative risk, 2.8; 95% confidence interval, 1 to 7.4; P =.03). Moreover, moderate macrovesicular steatosis was found in 6% of the grafts, resulting in a 40% graft loss rate. We found that an increased presence of neutrophilic infiltrates in the postreperfusion biopsy specimen, indicating PI, was related to an increased incidence of biliary complications. Moreover, moderate macrovesicular steatosis was associated with increased graft loss. Therefore, postreperfusion biopsies are useful in anticipating post-OLT complications.

Adult↗
PubMed2001

Risk factors for development of de novo neoplasia after liver transplantation.

Liver transplant recipients are at greater risk for de novo neoplasia, especially lymphoma and nonmelanoma skin cancer; however, risk factors for this complication have not been well studied. Clinical and pathological records of 137 consecutive liver transplant recipients who had survived for at least 1 year were reviewed to register de novo neoplasia. Ten variables were analyzed for their association with the development of de novo malignancies by means of a log-rank test and stepwise selection in a multivariate analysis using the Cox proportional hazard model. Thirty de novo neoplasias appeared in 22 of 137 transplant recipients between 12 and 104 months after orthotopic liver transplantation (OLT; median follow-up, 69 months): 14 patients had 21 skin cancers, 6 patients had solid-organ cancer, and 3 patients developed a lymphoproliferative disease. Probabilities of de novo neoplasia were 13% at 5 years post-OLT and 26% at 8 years post-OLT. The only associated risk factor for any neoplasia was age. Age and hepatocarcinoma were independent risk factors associated with skin cancer. That hepatocarcinoma in the explanted liver is an independent risk factor for skin cancer suggests there is individual susceptibility to both neoplasias.

Adolescent↗
PubMed2001

Hepatic metastases from colorectal cancer: preoperative detection and assessment of resectability with helical CT.

PURPOSE: To prospectively evaluate helical computed tomography (CT) in the preoperative detection of hepatic metastases and assessment of resectability with surgical, intraoperative ultrasonographic (US), and histopathologic correlation. MATERIALS AND METHODS: Between October 1995 and December 1998, preoperative staging with helical CT (5-mm collimation; reconstruction interval, 5 mm) was performed in 157 patients with hepatic metastases. Iodinated contrast material was injected intravenously (160-170 mL; rate, 2.5-3.0 mL/sec); acquisition began at 60-70 seconds. Four radiologists prospectively assessed the metastatic involvement of the liver by indicating the number and location of the lesions; resection was indicated in 113 patients (119 instances). Helical CT findings were correlated with pathologic and surgical findings on a lesion-by-lesion basis. RESULTS: Intraoperative US, palpation, and histopathologic examination revealed 290 liver metastases; helical CT correctly depicted 247. Helical CT results were the following: overall detection rate, 85.1% (95% CI: 80.8%, 89.3%); positive predictive value, 96.1% (95% CI: 92.9%, 98.1%); and false-positive rate, 3.9% (10 of 257 findings; 95% CI: 1.9%, 7.1%). False-positive findings were related to hemangioendothelioma, hemangioma, hepatic peliosis, biliary adenoma, centrilobar hemorrhage, biliary hamartoma, periportal fibrosis, and normal liver parenchyma. Curative resection was performed in 112 instances with a resectability rate of 94.1%. Four-year patient survival rate was 58.6%. CONCLUSION: Helical CT is a noninvasive, reliable, and accurate technique for imaging the liver and should be considered as the standard preoperative work-up of hepatic metastases from colorectal cancer.

Adult↗
PubMed2001

Influence of donor post-reperfusion changes on graft evolution after liver transplant.

INTRODUCTION: The increase in indications for liver transplantation has meant that waiting lists are growing ever longer. For this reason, broadening the donor pool is a priority for most groups. OBJECTIVE: The objective of this study was to analyze the predictive value of post-reperfusion biopsy in the evolution of graft function after liver transplantation. PATIENTS: One hundred and forty-eight liver biopsies, obtained after graft reperfusion, were analyzed. Eight pathological variables and thirty-seven clinical variables of the donors were recorded. Risk factors for presenting primary graft non-function or dysfunction were studied with logistic regression models. Factors associated to the long-term graft failure were studied using Cox analysis and actuarial survival curves. RESULTS: Microvesicular steatosis greater than 50% was the only risk factor associated to graft dysfunction in the multivariate logistic regression model. Microvesicular steatosis greater than 30%, severe hepatocyte necrosis and presence of abundant neutrophilic leukocytes were risk factors associated to graft failure in the univariate study. Only steatosis remained as an independent risk factor in the multivariate study. These grafts also presented poorer long-term survival. Abundant polymorphonuclear infiltrate was associated to a higher frequency of biliary complications. CONCLUSIONS: Microvesicular steatosis implies a better evolution than macrovesicular steatosis. Neutrophilic infiltrate and hepatocellular necrosis lead to poorer initial graft function and reduced long-term survival.

Actuarial Analysis↗