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Biomedical subjects

R Teixeira

Publications and source records attributed to R Teixeira.

At least 19 recordsLinked to original sources
PubMed2002

Brassica napus lines with rearranged Arabidopsis mitochondria display CMS and a range of developmental aberrations.

Numerous Brassica napus (+) Arabidopsis thaliana somatic hybrids were screened for male sterility and aberrant flower phenotypes. Nine hybrids were selected and backcrossed recurrently to B. napus. The resulting lines displayed stable maternal inheritance of flower phenotypes. Nuclear and organellar genomes were characterized molecularly using RFLP analysis. No DNA from A. thaliana was found in the nuclear genome after six back-crosses, whilst the mitochondrial genomes contained rearranged DNA from both A. thaliana and B. napus. Each line tested had a unique RFLP pattern of the mitochondrial DNA (mtDNA) that remained unchanged between the BC(3) and BC(6) generation. The plastid genomes consisted of B. napus DNA. Five lines of the BC(5) generation were subjected to more comprehensive investigations of growth, morphology and fertility. On the basis of these investigations, the five CMS lines could be assigned to two groups, one represented by three lines displaying reduced vegetative development, complete male sterility, and homeotic conversions of stamens into feminized structures. The second group, represented by the other two lines, were not completely male-sterile but still displayed severely affected flower morphologies. These two lines did not display any reduction in vegetative development. For both groups only stamens and petals suffered from the morphological and functional aberrations, while the sepals and pistils displayed normal morphology. All plants were fully female-fertile. Different rearrangements of the mitochondrial genome disturbed nuclear-mitochondrial interactions and led to various types of aberrant growth and flower development. The existence of numerous CMS lines with different mitochondrial patterns involving a species with a sequenced genome offers new opportunities to investigate the genetic regulation of CMS and its associated developmental perturbations.

Arabidopsis↗
PubMed2001

The role of different immunosuppression in the long-term histological outcome of HCV reinfection after liver transplantation for HCV cirrhosis.

BACKGROUND: The effect of the type of immunosuppression on the course of posttransplant hepatitis C virus (HCV) infection is unclear. The aim of this study was to evaluate the histological outcome of posttransplant HCV infection with respect to initial immunosuppressive therapy in a cohort of 59 of 65 HCV positive transplant patients who survived at least 12 months. METHODS: Initial immunosuppressive therapy was triple (cyclosporine or tacrolimus and azathioprine and prednisolone) in 41, double (cyclosporine and prednisolone) in 5, and single (cyclosporine or tacrolimus) in 13 patients. There was blinded histological evaluation, based on necroinflammatory activity (grading score:0-18) and fibrosis (staging score: 0-6). The median histological follow-up was 36 (12-72) months. RESULTS: In the last liver biopsy, high necroinflammatory activity indicating chronic hepatitis (grading score > or =4) was found in 42 (71%) and severe fibrosis or cirrhosis (staging score > or =4) in 18 (30.5%) patients. High necroinflammatory activity was associated significantly with absence of pretransplant alcohol abuse (P=0.01) and relatively with occurrence of posttransplant acute lobular hepatitis C (P=0.055). Development of severe fibrosis or cirrhosis was significantly associated only with the type of initial immunosuppressive therapy. In particular, severe fibrosis or cirrhosis developed significantly more frequently in patients treated with triple or double (17/46 or 37%) than with single initial immunosuppressive therapy (1/13 or 7.7%) (adjusted for biopsy time: P=0.045). CONCLUSIONS: Severe fibrosis or cirrhosis appears to develop in 30% of HCV transplant patients in a median of 3 years and to be associated with heavier initial immunosuppression.

Adult↗
PubMed2001

Immunohistochemical detection of p53 protein expression as a prognostic indicator in Wilms tumor.

BACKGROUND: Mutations of the tumor suppressor gene p53 are commonly found in several kinds of human cancer. In some types of neoplasms, accumulation of p53 protein has been reported to correlate with more aggressive clinical behavior. The role of p53 expression in Wilms tumors (WT) is not clear yet, but most studies have confirmed its correlation with anaplasia and advanced stage disease. PROCEDURE: Ninety-seven WT were evaluated for p53 expression by immunohistochemistry in formalin-fixed paraffin-embedded tissue and correlated with outcome. Tumors were classified as p53-Negative (p53-N) when no positivity was observed or only few cells showed weak positivity (0/1+) and p53-Positive (p53-P) when there was a diffuse and strong nuclear positivity (2+/3+). RESULTS: p53-P was detected in 13 out of 97 tumors and was associated with disease relapse (39 vs.17%; P = 0.06) but not with anaplasia. Among p53-N patients only 5% had metastatic disease compared with 31% of the p53-P sample. (P = 0.038). Overall survival was 94% for patients with p53-N vs. 85% for patients with p53-P at 1 year (P = 0.34). CONCLUSIONS: p53 expression in Wilms tumor detected by immunohistochemistry seems to be associated with advanced disease and relapse.

Biomarkers, Tumor↗
PubMed2001

Management of recurrent hepatitis C after liver transplantation.

Hepatitis C virus (HCV) reinfection is almost universal in patients transplanted for HCV-related cirrhosis. The medium-term survival after orthotopic liver transplantation (OLT) is similar to other transplanted patients, but the long-term survival remains uncertain. The prevention and an effective treatment of progressive liver disease are the primary aims in HCV recurrence. Interferon and ribavirin, as monotherapy or in combination, have been tried to treat or prevent HCV recurrence. Preliminary studies suggest a better chance of initial HCV clearance and better results in preventing HCV recurrence with combination therapy. IFN or ribavirin, as monotherapy, may normalize liver enzymes, but only gives rise to a transient virological response, without histological improvement. Combination IFN and ribavirin may be able to prevent progression of HCV-related graft disease, but indications and duration of treatment need further evaluation. No clear association between type and dose of immunosuppressive and outcome of post-transplant HCV recurrence has been found. Strategies to minimize the effects of immunosuppressive drugs include dose reduction of all agents and the selective discontinuation of individual agents. Initial immunosuppression with a single drug may inhibit or delay the severe fibrosis, and further investigation with a single immunosuppressive regimen to evaluate the outcome of recurrent hepatitis C should be performed. The recent evidence that mycophenolate may have an antiviral effect needs a clinical confirmation. Retransplantation survival is better with early retransplantation, and for indications not directly related to viral recurrence.

Adrenal Cortex Hormones↗
PubMed2001

Hepatic artery thrombosis after orthotopic liver transplantation: a review of nonsurgical causes.

Hepatic artery thrombosis (HAT) is one of the principal causes of morbidity and graft loss following liver transplantation. There are several risk factors for the development of HAT; technical aspects of the arterial anastomosis are important particularly for early thrombosis, but the improvement of surgical technique has lessened this problem. Apart from technical causes, other risk factors include a variety of conditions such as low donor/recipient age ratio, immunologic factors, clotting abnormalities, tobacco use, and infections. In particular, cytomegalovirus (CMV) infection of endothelial cells has been recently suggested as an infective cause of HAT, as it is known to be followed by a rapid procoagulant response. Thus, latent CMV in an allograft may become activated and promote or contribute to vascular thrombosis. This review evaluates these aspects, focusing on data relating CMV infection or viremia to HAT following liver transplantation.

Blood Coagulation Disorders↗
PubMed2001

Midline nasal mass in infancy: a nasal glioma case report.

Congenital midline nasal masses are rare anomalies that occur in about one in 20,000-40,000 live births. The most common are dermoid/epidermoid tumors, nasal cerebral heterotopias (nasal gliomas), and nasal encephaloceles; some have an actual or potential central nervous system connection. Nasal gliomas are CNS masses of neurogenic origin which have lost their intracranial connections and present as an obvious external or intranasal mass at birth without associated surgical symptoms. Careful evaluation is required to confirm the diagnosis and appropriate management. The interpretation of CT and MR images can be difficult but is useful in differentiating nasal gliomas from other congenital nasal masses. The presence of a fibrous stalk may be associated with cranial defects and CSF leak. Excisional biopsy allows histopathologic diagnosis and is the definitive treatment. They are benign lesions, and recurrences are rare, so conservative cosmetic surgical techniques should be chosen for gliomas where there is no proven intracranial extension. The authors report an illustrative nasal glioma case in a one-year-old male infant with extranasal and intranasal components, and discuss the therapeutic options.

Biopsy↗
PubMed2001

Schistosomiasis mansoni is associated with pyogenic liver abscesses in the state of Minas Gerais, Brazil.

The association between pyogenic liver abscesses and schistosomiasis has been confirmed by clinical and experimental studies. In this retrospective study of 78 patients with pyogenic liver abscesses the association with schistosomiasis has been investigated. Pyodermitis, a known focus of bacteremia, was observed in 19 patients (24%). Blood eosinophilia was observed in 30 patients (39%). Staphylococcus aureus was cultured from abscesses in 17 out of 38 patients (45%). Forty-one out of 57 patients (53%) had stool examination. Schistosoma mansoni was the main parasite identified. Eggs of S. mansoni were also identified in liver biopsies in 7 out of 19 patients who did the exam. The large number of young patients with liver abscesses described here is different from what has been observed in developed countries. This clinical study provide support for the concept that granulomas of S. mansoni in the liver are foci for colonization with S. aureus, which in presence of staphylococcal bacteremia can form liver abscesses.

Adolescent↗
PubMed2001

The 2000 election and the future of U.S. politics.

After presenting data on how various ethnic/racial and income groups cast their votes in the 2000 presidential election, this article addresses the question of why Al Gore did well enough to beat George W. Bush in the popular vote but not well enough to prevent Bush from achieving a virtual tie. The author challenges some arguments put forward--Gore's being "too much of a populist" and not running on the achievements of the Clinton administration--and, based on poll data, suggests that more important to voters were problems of trust, cultural conservatism, and generic anti-government sentiment. These findings on the 2000 election suggest a number of possibilities about the political future and some ways in which the Democratic Party might develop its program to win back voters.

Attitude to Health↗
PubMed2000

The influence of cytomegalovirus viraemia on the outcome of recurrent hepatitis C after liver transplantation.

BACKGROUND: Several interrelated host and hepatitis C virus (HCV) associated factors have been proposed to explain the variable outcomes in HCV recurrence. Recent evidence suggests that cytomegalovirus (CMV) infection not only is co-factor in progression of HCV recurrence but may precipitate allograft rejection. We investigated whether short-term CMV viremia influences HCV recurrence, the number and grade of acute rejection episodes, and the histological course of HCV recurrence during the first year after orthotopic liver transplantation (OLT) for HCV-related cirrhosis. METHODS: A cohort of 39 patients transplanted for cirrhosis HCV-related was analyzed. Patients were evaluated twice weekly for CMV infection by a blood polymerase chain reaction (PCR) assay. Triple therapy with cyclosporine or tacrolimus, azathioprine and prednisolone was the initial immunosuppressive regimen. Preemptive treatment with ganciclovir was started when two consecutive PCRs for CMV were positive. Liver biopsies were performed on day 7 after OLT or when indicated. A 3-day IV 1 g methilprednisolone was given to patients with moderate or severe rejection. Ishak's score was used to grade inflammation and to stage fibrosis. RESULTS: Neither CMV viremia nor CMV disease after OLT for HCV-related cirrhosis adversely influenced the incidence and grade of acute rejection episodes nor the histological outcome of post transplant HCV recurrence, during the first year after liver transplantation. CONCLUSION: CMV viremia as detected by PCR does not affect the progression of HCV recurrence in liver grafts.

Adult↗
PubMed2000

Schistosoma mansoni: assessment of morbidity before and after control.

The literature on the assessment of morbidity due to Schistosoma mansoni infection is updated. Imaging techniques such as ultrasonography, echodoppler cardiography, computerized tomography (CT scan) and magnetic resonance imaging (MRI) introduced a new perspective, and expanded our knowledge on morbidity. Three well-defined syndromes caused by schistosomiasis mansoni have been described: the stage of invasion, acute schistosomiasis (Katayama fever), and chronic schistosomiasis. Complications of the acute and chronic syndromes have also been reported: pulmonary hypertension, neuroschistosomiasis, association with Salmonella, association with Staphylococci, viral hepatitis B, glomerulonephritis. In most individuals with hepatosplenic schistosomiasis the spleen is increased in size. Hepatosplenic schistosomiasis can, however, occur without splenomegaly. The definition of hepatosplenic schistosomiasis in endemic areas as the finding of S. mansoni eggs in the stools in an individual with hepatosplenomegaly is not satisfactory anymore. Many aspects of morbidity are expected to change after schistosomiasis control. Some are expected to change quickly (worm burden, Salmonella bacteremia, hepatosplenic schistosomiasis in children) whereas others shall remain for years (pulmonary hypertension, glomerulonephritis, neuroschistosomiasis). Intestinal schistosomiasis in individuals with low worm burdens is very difficult to diagnose and therefore laborious to control.

Brazil↗
PubMed2000

Recurrent hepatitis C after liver transplantation.

Cirrhosis due to hepatitis C is now the commonest indication for liver transplantation in Western Europe and in the United States. Graft reinfection is almost universal. The natural history of recurrent hepatitis C ranges from minimal damage to cirrhosis in a few months or years. Different virus and host immune factors are involved in the pathogenesis of hepatitis and are determinants of the outcome. The association between immunosuppression and severity of HCV recurrence is conflicting and remains to be evaluated fully. The treatment of recurrent HCV disease with IFN or ribavirin, as monotherapy, is ineffective. Preliminary results from combination therapy, however, are encouraging. Currently, a reasonable approach would be to treat patients with histological and clinical disease progression. New approaches for the prophylaxis of recurrent hepatitis C are under evaluation but whether this treatment will influence the severity of liver disease or the outcome of recurrence is still unknown.

Antiviral Agents↗
PubMed2000

Happy with health care?

The American Association of Health Plans (the main HMO trade association), in making the case against patients' rights legislation, points to polling data that show Americans are basically satisfied with managed care plans. Although large majorities, including those with HMOs, do say they are "satisfied" with their health care plans, HMO members are less satisfied than members of other types of plans. And if we look beyond personal-satisfaction ratings, we find plenty of evidence for public concern about HMOs in particular and the health care system in general. Americans are supportive of HMO regulation, and despite their willingness to say they are "satisfied" with their health care plans, they harbor a lot of worries about the future--treatment that could be denied them, costs that could ruin them, and loss of coverage. The public sees the need for major change not just in HMOs but in the health care system as a whole. As HMO lobbyists scramble for new arguments against legislation, they will likely persist in misrepresenting and misusing polling data to make their case.

Costs and Cost Analysis↗
PubMed2000

Popular opinion on tax cuts and Social Security.

A review of recent opinion polls reveals the U.S. public's views on budget priorities and Social Security. The public wants more spending on Social Security, Medicare, and other domestic programs, chiefly education and health care, and prefers these spending priorities--by up to a 70 percent majority--to paying down the national debt and cutting taxes. The public supports the Social Security system but doubts it can continue to deliver the goods. To remedy this problem, it is willing not only to use part of the surplus but to raise the cap on payroll taxes. The public does not support benefit cuts or an increase in the retirement age. And the public remains unsure to hostile about the role of the stock market, whether in individual accounts or in the Social Security trust fund.

Humans↗
PubMed1998

Schistosomiasis and associated infections.

In hospital-based series viral hepatitis B has been frequently described in association with schistosomiasis whilst in field-based studies the association has not been confirmed. The association between schistosomiasis and Salmonella bacteraemia has been well documented. More recently, acute schistosomiasis has been shown to be a facilitating factor in the genesis of pyogenic liver abscesses caused by Staphylococcus aureus. New evidences indicate an interaction between the acquired immunodeficiency syndrome (AIDS) and schistosomiasis. In this paper, data on the association of schistosomiasis with other infections are updated.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Co-Infection by HTLV-I/II is Associated With Increased Viral Load in PBMC of HIV-1 Infected Patients in Bahia, Brazil.

To evaluate the viral load in peripheral blood mononucler cells (PBMC) of patients infected by HIV-1 we performed 96 quantitative cultures in 74 patients infected by HIV-1, using the co-culture method. The viral load was expressed in tissue culture infectious doses (TCID), and the results were analyzed according to gender, age and clinical stage of patients, duration of previous antiretroviral therapy, detectable p24 antigenemia, CD4(+)/CD8(+) cell counts, co-infection by HTLV-I/II and viral subtype. We detected a statistically significant association between co-infection by HTLV-I/II and viral load higher than >50 TCID (p=0.003). We also found a significant association between co-infection by HTLV-I/II and p24 antigenemia (p=0.028). CD4(+) cell counts were significantly higher for patients presenting negative cultures, but there was no detectable association between lower CD4(+) cell counts and higher TCID. The majority of patients were infected by subtype B virus. The observation in this study that co-infection with HTLV-I/II was significantly associated with higher viral load raises the possibility that these agents act as co-factors of AIDS progression, in doubly-infected patients.

Journal Article↗
PubMed1997

Efficacy and Tolerability of Liposomal Amphotericin B (Ambisome) in the Treatment of Visceral Leishmaniasis in Brazil.

Thirty-two patients were enrolled in an open-label, dose/schedule ranging clinical trial to evaluate the efficacy and tolerability ofliposomal amphotericin B (Ambisome) in the treatment of visceral leishmaniasis. All patients received a dose of 2mg/kg daily for the first 4 days, followed by a single repeat dose of 2mg/kg at day 10 in 4 patients (total dose 10mg/kg); repeat doses on days 5, 6, and 10 in 13 patients (total dose 14mg/kg); or daily doses were continued on days 5 through 10 in 15 patients (total dose 20mg/kg). Patients had a mean age of 9 years, ranging between 3 and 26 years. Their mean weight was 25.9kg, ranging between 9.5kg and 75kg. All patients had splenomegaly, 31/32 had hepatomegaly, and 20 patients tested had leishmania documented on splenic aspirate. Six of the 32 patients were treated after relapse following antimony therapy. The duration of illness prior to therapy was a mean of 2 months, ranging between 2 weeks and 23 months. During and after treatment, there were significant reductions in liver and spleen sizes, and significant increases in body weight, hemoglobin levels and white blood cell counts. All patients showed initial cure at the 1 month follow-up. Seven patients relapsed between 2 and 6 months after the start of treatment. There was no dose relationship to the occurrence of relapse. The relapse rate in children 5 years of age or less was 7/15 (47%). Associated causes of relapse were refractory disease (i.e., previous relapses) in 2, severe malnutrition in 1, and concurrent disease (meningococcal meningitis) in 1. In the other 2 cases, no associated event was observed except young age (ages 3 and 5 years). One relapsed patient was treated successfully with 14 days of lipid amphotericin B, and the others were cured by use of antimony for 20 to 30 days. There were no dose related adverse events. The most common event was fever which occurred in 13/32 patients (41%); 3/4 patients in the 10mg dose group, 7/13 in the 14mg dose group, and 3/15 in the 20mg dose group. Three patients had cardiac arrhythmia, one also with myocarditis diagnosed 2 weeks after therapy was discontinued. One patient developed hepatitis after dose 3 and the drug was discontinued. We concluded that liposomal amphotericin B is effective in a daily dose of 2mg/kg given for 5-10 doses as an initial cure, but that relapse occurs in young children, particularly those with documented treatment resistant disease or concurrent malnutrition or infection. Patients should be carefully monitored for these risk factors before and during the months alter therapy, and for the occurrence of arrhythmia, cardio-pulmonary effects or hepatotoxicity. This treatment provides an important advance over previously used antimony therapy and appears to be more effective and well-tolerated than non-lipid amphotericin B.

Journal Article↗
PubMed1997

Leprosy and AIDS: Report of a Fatal Case and Literature Review.

We report a severe fatal lepromatous leprosy case in an adult homosexual male 2 years after AIDS class IV was diagnosed. Multidrug therapy including thalidomide for erythema nodosum leprosum (ENL) was ineffective. The patient died with multiple large skin ulcerations due to multibacillary leprosy. Leprosy in AIDS patients may present as a severe uncontrolled disease, with extensive ENL unresponsive to therapy.

Journal Article↗