Search PubMed⌕ Search

Biomedical subjects

A Rodriguez

Publications and source records attributed to A Rodriguez.

At least 109 records · Page 6Linked to original sources
PubMed1998

Risk factors, treatment, and outcome of central nervous system recurrence in adults with intermediate-grade and immunoblastic lymphoma.

To evaluate the incidence, risk factors, and outcome of central nervous system (CNS) recurrence in adult patients with non-Hodgkin's lymphoma, we evaluated 605 newly diagnosed patients with large-cell and immunoblastic lymphoma who participated in prospective chemotherapy studies. The Kaplan-Meier estimate of probability of CNS recurrence at 1 year after diagnosis was 4.5% (95% confidence interval [CI], 4.4 to 4.6). Twenty-four patients developed CNS recurrence after a median of 6 months from diagnosis (range, 0 to 44 months). In univariate analysis, an increased risk for CNS recurrence was associated with an advanced disease stage (P = .0014), an increased LDH (P = .0000), the presence of B-symptoms (P = . 0037), involvement of more than one extranodal site (P = .0000), poor performance status (P = .0005), and B-cell phenotype (P = .008). Bone marrow involvement (P = .005), involvement of parenchymal organs (P = .03), and involvement of skin, subcutaneous tissue, and muscle (P = .002) were also associated with an increased risk for CNS disease. Multivariate logistic regression analysis identified only involvement of more than one extranodal site (P = .0005) and an increased LDH (P = .0008) as independent predictors of CNS recurrence. Established CNS recurrence had a poor prognosis. Only 1 of 24 patients remains alive and the Kaplan-Meier estimate of probability of survival at 1 year after the diagnosis of CNS recurrence is only 25.3% (95% CI, 6.9 to 43.7). Intrathecal treatment provided symptomatic benefit in only 1 of 6 patients. Radiation treatment provided symptomatic improvement in 6 of 9 patients treated. However, remissions were short and followed by systemic or CNS recurrence. Serum LDH and involvement of more than one extranodal site are independent risk factors for CNS recurrence in patients with large-cell lymphoma. The presence of both risk factors identifies a patient group at high risk for CNS recurrence. Established CNS recurrence can be rapidly fatal. Transient responses occur after radiation treatment.

Adult↗
PubMed1998

Current global status of carotid artery stent placement.

Our purpose was to review the current status of carotid artery stent placement throughout the world. Surveys were sent to major interventional centers in Europe, North and South America, and Asia. Information from peer-reviewed journals was also included and supplemented the survey. The survey asked various questions regarding the patients enrolled, procedure techniques, and results of carotid stenting, including complications and restenosis. Of the centers which were sent surveys, 24 responded. The total number of endovascular carotid stent procedures that have been performed worldwide to date included 2,048 cases, with a technical success of 98.6%. Complications that occurred during carotid stent placement or within a 30-day period following placement were recorded. Overall, there were 63 minor strokes, with a rate of occurrence of 3.08%. The total number of major strokes was 27, for a rate of 1.32%. There were 28 deaths within a 30-day postprocedure period, resulting in a mortality rate of 1.37%. Restenosis rates of carotid stenting have been 4.80% at 6 mo. Endovascular stent treatment of carotid artery atherosclerotic disease is growing as an alternative to vascular surgery, especially for patients that are at high risk for standard carotid endarterectomy. The periprocedural risks for major and minor strokes and death are generally acceptable at this early stage of development.

Angioplasty, Balloon↗
PubMed1998

Multiple analysis of a foodborne outbreak caused by infant formula contaminated by an atypical Salmonella virchow strain.

An outbreak of food poisoning involving most autonomous Spanish communities was detected in the first half of 1994. The causative food was infant formula milk contaminated by lactose-fermenting Salmonella virchow. It was not possible to isolate the causative strain from the manufacturer's facilities. During the same period of time, there was a significant increase in lactose-non-fermenting Salmonella virchow strains compared with the same period in previous years. Simultaneously, lactose-non-fermenting strains were recovered from clinical samples from children and from some milk samples that were involved in the outbreak. Therefore, it was speculated that the outbreak might be more extensive than initially thought. The following epidemiological markers were used for typing the Salmonella virchow strains involved in the outbreak: (i) phage typing: (ii) ribotyping, using a set of 20 different endonucleases: and (iii) pulsed-field gel electrophoresis, using three different endonucleases. The most useful markers for this serotype were phage typing and pulsed-field gel electrophoresis, since ribotyping was not able to distinguish all strains tested. The results obtained revealed that the outbreak was caused by at least two strains: one presenting phage type 4-4a and pulsed-field patterns A1 or A2 and L+ or L-, and another presenting phage type 2 and pulsed-field patterns A1 or A2 and L+ or L-. The results indicate that the outbreak was more extensive than initially thought and that the Virchow serotype is very clonal in Spain.

Animals↗
PubMed1998

Fatty acid desaturase activities and polyunsaturated fatty acid composition in human liver between the seventeenth and thirty-sixth gestational weeks.

OBJECTIVE: The aim of the study was to characterize n-3 and n-6 fatty acid delta5- and delta6-desaturase activities and their time course variations in human fetal liver between the 17th and 36th gestational week. STUDY DESIGN: Twenty-one biologic samples were obtained after legally approved medical abortion, according to French law. The desaturase activities were measured in the 21 liver samples by a radiochemical method by means of reverse-phase high-performance liquid chromatography. The fatty acid composition (percentage by weight) of liver phospholipids was assessed in 16 samples by gas-liquid chromatographic analysis. RESULTS: Both delta5- and delta6-desaturase activities were significantly expressed between the 17th and 36th gestational weeks. During the second trimester n-6 fatty acid delta5- and delta6-desaturase activities showed opposite patterns of variation; both then remained stable between the 25th and 36th weeks. Delta6-desaturation was higher in n-3 than n-6 fatty acids and peaked at the 18th gestational week. The percentages of linoleic and docosahexaenoic acids in liver microsomes were positively correlated with the gestation age (P < .01), whereas arachidonic acid remained stable. CONCLUSION: Significant n-3 and n-6 delta5- and delta6-desaturase activities are expressed in human fetal liver as early as the 17th gestational week and are stable throughout the third trimester. Their theoretic capacity evaluated from in vitro measurements appears lower than polyunsaturated fatty acid requirements and is not directly related to liver microsomal membrane fatty acid composition.

Arachidonic Acid↗
PubMed1998

Outcomes in anterior uveitis associated with the HLA-B27 haplotype.

OBJECTIVE: This study aimed to test the hypothesis that patients presenting with anterior uveitis who are HLA-B27 positive, either with or without associated systemic disease, have a less-favorable outcome than do patients with idiopathic anterior uveitis who are HLA-B27 negative. DESIGN: Retrospective case-controlled series. PARTICIPANTS: Ninety-seven patients who were HLA-B27 positive with no systemic disease, 94 patients who were HLA-B27 positive with systemic disease, and 72 patients who were HLA-B27 negative who presented with anterior uveitis were studied. MAIN OUTCOME MEASURES: Ocular complications (e.g., secondary glaucoma, cataract formation, pupillary synechiae, vitritis, cystoid macular edema, and optic disc edema), medical and surgical treatment, number of recurrent attacks, and final visual acuity were recorded for all patients. RESULTS: The patients who were HLA-B27 positive, either with or without systemic disease, experienced a greater number of complications than did the patients who were HLA-B27 negative. Periocular corticosteroids, systemic corticosteroids, and systemic immunosuppressive chemotherapy were required in a far greater number of HLA-B27-positive patients than in HLA-B27-negative patients (60% vs. 11%, 53% vs. 7%, and 18% vs. 1%, respectively; P < 0.001). The percentage of legally blind eyes was significantly greater in the HLA-B27-positive group, both with and without systemic disease, when compared with the HLA-B27-negative group (11% vs. 2%; P < 0.005). CONCLUSIONS: The prognosis of anterior uveitis associated with the HLA-B27 haplotype, either with or without associated systemic disease, is less favorable when compared with that of HLA-B27-negative patients with idiopathic anterior uveitis.

Adolescent↗
PubMed1998

Chromosomal sublocalization of the transcribed human telomere repeat binding factor 2 gene and comparative mapping in the mouse.

Telomere repeat binding factor 2 (TERF2) is one of two recently cloned mammalian telomere binding protein genes. TERF2 binds as a dimer with high affinity to the double-stranded TTAGGG telomeric repeat through an evolutionarily conserved myb-type DNA binding domain. TERF2 prevents telomere end-to-end fusion and may be important in maintaining genomic stability. We localized the transcribed TERF2 gene to human chromosome 16q22.1, tightly linked to the EST HUM000S343. The mouse Terf2 gene is situated by itself in a newly defined "bin" on chromosome 8 one crossover distal to Psm10 and Sntb2. Human TERF2 and mouse Terf2 are therefore part of a large evolutionarily conserved linkage group comprised of at least 25 known paralogous genes between human chromosome 16q and mouse chromosome 8.

Animals↗
PubMed1998

dRGS7 encodes a Drosophila homolog of EGL-10 and vertebrate RGS7.

We identified a Drosophila gene encoding a homolog of the regulator of G-protein signaling (RGS) protein family. This gene (dRGS7) is expressed in neurons of the embryo and adult fly and is predicted to encode a 428-amino acid protein with >55% overall amino acid sequence identity with the vertebrate protein RGS7 and the C. elegans EGL-10. The dRGS7 protein is 50% conserved in the C-terminal RGS domain with RGS7 and EGL-10 but, remarkably, displays much greater conservation with the N-terminal regions of these proteins. This finding implies a conserved function for these homologs from divergent species involving domains outside the RGS domain. The dRGS7 protein also has a domain of similarity with Dishevelled and pleckstrin, raising the possibility that these proteins interact with common signaling components.

Amino Acid Sequence↗
PubMed1998

Use of spiral computed tomography for the assessment of blunt trauma patients with potential aortic injury.

PURPOSE: The purpose of this study was to prospectively examine the accuracy of contrast-enhanced spiral thoracic computed tomography (CEST-CT) for direct detection of traumatic aortic injury resulting from blunt thoracic trauma. METHODS: During a 25-month period, all blunt trauma patients who had abnormal mediastinal contours on admission chest radiographs underwent CEST-CT. The presence and location of mediastinal blood and any direct signs of aortic injury, such as pseudoaneurysm, were recorded. Computed tomographic results were compared with results of aortography, when performed, surgery, or clinical status at discharge. RESULTS: There were 7,826 patients classified as having blunt trauma admitted during the study. Of these, 1,104 (14.3%) had CEST-CT performed. Mediastinal hemorrhage was detected on 118 (10.7%) of all thoracic computed tomographic scans. Direct evidence of aortic injury was detected in 24 patients (20.3%) with mediastinal hemorrhage and 2.2% of all patients undergoing CEST-CT. In this prospective series, CEST-CT was 100% sensitive based on clinical follow-up; it was 99.7% specific, with 89% positive and 100% negative predictive values and an overall diagnostic accuracy of 99.7%. CONCLUSION: CEST-CT is a valuable ancillary study for the detection of traumatic aortic injury. Spiral computed tomography is accurate for the detection and localization of both hemomediastinum and direct signs of aortic injury.

Acute Disease↗
PubMed1998

Comparative study of the use of poly(glycolic acid), calcium alginate and pluronics in the engineering of autologous porcine cartilage.

New cartilage formation has been successfully achieved by technology referred to as tissue engineering. Polymers and hydrogels such as poly(glycolic acid), calcium alginate, and poly(ethylene) and poly(propylene) hydrogels have been used as cell carriers to regenerate cartilage in the nude mouse model. The next step toward human applications of engineered cartilage is to demonstrate their potential in immunocompetent animal models. This study compared the suitability of three polymers for generating tissue engineered elastic cartilage using autologous cells in an immuno-competent porcine animal model. Auricular cartilage was obtained from pigs. Chondrocytes were isolated onto fiber based poly(glycolic acid) (PGA) scaffolds or suspended in calcium alginate or pluronic F127 gel at constant concentrations. Chondrocyte-polymer constructs were either implanted (PGA) or injected (calcium alginate and pluronic) as autologous implants subcutaneously into the pigs from which the cells had been isolated. Specimens were harvested and analyzed grossly and historically after 6 weeks in vivo. All explants demonstrated cartilage formation to a variable degree. When using PGA or calcium alginate, the overall histological appearance of the tissue formed is that of fibrocartilage with thick bundles of collagen dispersed in the tissue. When using pluronics as scaffold, histologic features resemble those of native elastic cartilage, showing a more organized arrangement of the cells, which seems to correlate to functional properties as elastin presence in the tissue engineered cartilage. Elastic cartilage engineered in an immunocompetent animal model varies with the type of polymer used. The behavior of the cell-polymer constructs is not fully understood and outcome seems to be related to several factors, including inflammatory reaction. Further studies with similar models are needed to determine the feasibility of engineering tissue generated from different cell-polymer constructs prior to human application.

Alginates↗
PubMed1998

High-dose chemotherapy for relapsed and refractory diffuse large B-cell lymphoma: mediastinal localization predicts for a favorable outcome.

PURPOSE: This study was performed to evaluate the outcome of high-dose chemotherapy and autologous transplantation in patients with diffuse B-cell large-cell lymphoma, and, specifically, to evaluate the impact of primary mediastinal localization on the outcome of high-dose chemotherapy. PATIENTS AND METHODS: A retrospective review was performed of all patients with diffuse large B-cell lymphoma who underwent autologous marrow or peripheral-blood stem-cell transplantation at our institution between January 1 986 and December 1995. RESULTS: Ninety patients were identified, of whom 31 (34%) had a primary mediastinal B-cell large-cell lymphoma (PML). Cumulative probabilities of disease-free survival, overall survival, and disease progression are 40% (95% confidence interval [CI], 29 to 51), 42% (95% CI, 31 to 53), and 52% (95% CI, 40 to 64), respectively. By univariate analysis, low lactate dehydrogenase (LDH) level and low Ann Arbor stage at transplant were associated with improved survival and disease-free survival. There was a trend for improved disease-free survival and survival for patients with PML. Multivariate stepwise Cox regression analysis showed that LDH level, Ann Arbor stage, and primary mediastinal localization were independent favorable prognostic factors for disease-free survival and survival. LDH level and Ann Arbor stage were also predictive for the risk of disease progression. CONCLUSION: Our results indicate that patients with PML may display an increased susceptibility to high-dose chemotherapy compared with other types of B-cell large-cell lymphoma. These findings, if confirmed, may have implications for the initial management of patients with PML.

Adolescent↗
PubMed1998

Hyper-CVAD and high-dose methotrexate/cytarabine followed by stem-cell transplantation: an active regimen for aggressive mantle-cell lymphoma.

PURPOSE: Diffuse and nodular forms of mantle-cell lymphoma (MCL) are consistently associated with poor prognosis. In an effort to improve the outcome, we adopted a treatment plan that consisted of four courses of fractionated cyclophosphamide (CY) 1,800 mg/m2 administered with doxorubicin (DOX), vincristine (VCR), and dexamethasone (Hyper-CVAD) that alternated with high-dose methotrexate (MTX) and cytarabine (Ara-C). After four courses, patients were consolidated with high-dose CY, total-body irradiation, and autologous or allogeneic blood or marrow stem-cell transplantation. PATIENTS AND METHODS: Forty-five patients were enrolled; 25 patients were previously untreated, 43 patients had Ann Arbor stage IV disease, and 42 patients had marrow involvement. Forty-one patients had diffuse histology, two patients had nodular, and two patients had blastic variants. RESULTS: Hyper-CVAD/MTX-Ara-C induced a response rate of 93.5% (complete response [CR], 38%; partial response [PR], 55.5%) after four cycles of pretransplantation induction chemotherapy. All patients who went on to undergo transplantation achieved CRs. For the 25 previously untreated patients, the overall survival (OS) and event-free survival (EFS) rates at 3 years were 92% (95% confidence interval [CI], 80 to 100) and 72% (95% CI, 45 to 98) compared with 25% (95% CI, 12 to 62; P = .005) and 17% (95% CI, 10 to 43; P = .007), respectively, for the previously treated patients. When compared with a historic control group who received a CY, DOX, VCR, and prednisone (CHOP)-like regimen, untreated patients in the study had a 3-year EFS rate of 72% versus 28% (P = .0001) and a better OS rate (92% v 56%; P = .05). Treatment-related death occurred in five patients: all were previously treated and two received allogeneic transplants. CONCLUSION: The Hyper-CVAD/MTX-Ara-C program followed by stem-cell transplantation is a promising new therapy for previously untreated patients with MCL.

Adult↗
PubMed1998

Earlier onset of Alzheimer's disease in men with Down syndrome.

BACKGROUND: Virtually all individuals with Down syndrome (DS) have neuropathologic changes characteristic of Alzheimer's disease (AD) beginning at 40 years of age. Few studies have examined factors that influence age at onset of AD in DS. We investigated whether sex differences in age at onset and risk of AD among adults with DS are similar to those observed in the general population and whether the effect of sex on risk of AD is modified by apolipoprotein E (APOE) genotype. METHODS: A community-based sample of 111 adults with cytogenetically confirmed DS (34 to 71 years of age) was ascertained through the New York State Developmental Disabilities system. A semistructured interview with caregivers and review of medical records was used to ascertain the presence or absence of AD. APOE genotyping was carried out without knowledge of the subject's medical history or clinical diagnosis. RESULTS AND CONCLUSIONS: Both male gender and the presence of an APOE epsilon4 allele were associated with an earlier onset of AD. Compared with women, men with DS were three times as likely to develop AD. Compared with those with the APOE 3/3 genotype, adults with DS with the 3/4 or 4/4 genotypes were four times as likely to develop AD. No individual with an APOE epsilon2 allele developed AD. No evidence of interaction of sex and APOE genotype was found in risk of AD. The higher risk of AD in men may be related to differences in hormonal function between men and women with DS that are distinct from those in the general population.

Adult↗
PubMed1998

Prevalence of chronic medical conditions in adults with mental retardation: comparison with the general population.

We interviewed caregivers and reviewed medical records of 278 adults with mental retardation with and without Down syndrome, 45 to 74 years of age. Standardized morbidity ratios were used to compare frequency of medical disorders in these adults to frequency in the general population. In adults with mental retardation, the frequency of common age-related disorders was comparable to that in the general population, but there was an increased frequency of thyroid disorders, nonischemic heart disorders, and sensory impairment. Surveillance of health status and increased access to health care for screening and treatment of age-related disorders that are more frequent in adults with mental retardation would be important to prevent the development or delay the impact of these conditions and to promote healthy aging.

Adult↗
PubMed1998

Delta6- and delta5-desaturase activities in the human fetal liver: kinetic aspects.

Delta6- and delta5-desaturase activities were studied in human fetal liver microsomes obtained after legally approved therapeutic abortion. Enzyme activities were measured by a radiochemical method using reverse-phase high performance liquid chromatography (HPLC). Free and phospholipid fatty acids were assessed in each liver sample by a combination of thin-layer chromatography (TLC) and gas-liquid chromatography (GLC) procedures. The kinetic measurements showed higher delta6-desaturase activity for the n-3 series than for the n-6 series. Apparent Km of 6.5, 3.9, and 24.5 microM and Vm of 7.5, 9.1, and 24.4 pmol x min(-1) x mg(-1) were obtained, respectively, for 18:2n-6 delta6-, 20:3n-6 delta5-, and 18:3n-3 delta6-desaturases. Beyond 30, 20, and 60 microM of 18:2n-6, 20:3n-6, and 18:3n-3 concentration, respectively, the enzyme activity deviated from Michaelis-Menten kinetics, suggesting an inhibition by excess substrate which is unlikely to occur in vivo as endogenous substrate concentration is much lower. We observed a breakdown in linearity between desaturase activity and microsomal protein concentration beyond 4-5 mg microsomal protein, whatever the enzyme or substrate. Both this phenomenon and the inhibition due to excess substrate should be taken into account in the determination of delta6- and delta5-desaturase activities. Comparison of concentrations of the respective endogenous substrates and the kinetic constants of each enzyme suggested that the higher delta6-desaturase activity observed for the n-3 series than for the n-6 series is not physiologically relevant in human fetal liver.

Delta-5 Fatty Acid Desaturase↗
PubMed1997

The 18-wheeler mutation reveals complex antibacterial gene regulation in Drosophila host defense.

Mammals and insects employ similar Rel/NF-kappaB signaling cascades in their humoral immune responses. The mammalian interleukin-1 type I receptor (IL-1R) is one way of activating this cascade. The Drosophila Toll protein, whose cytoplasmic domain shows striking similarity to that of the IL-1R, acts in the humoral antimicrobial response. Here we demonstrate that a second IL-1R-related Drosophila protein, 18-Wheeler (18W), is a critical component of the humoral immune response. 18-wheeler is expressed in the larval fat body, the primary organ of antimicrobial peptide synthesis. In the absence of the 18W receptor, larvae are more susceptible to bacterial infection. Nuclear translocation of the Rel protein Dorsal-like immunity factor (Dif) is inhibited, though nuclear translocation of another Rel protein, Dorsal, is unaffected. Induction of several antibacterial genes is reduced following infection, relative to wild-type: attacin is reduced by 95%, cecropin by 65% and diptericin by 12%. Finally, 18-wheeler (18w) expression is induced in response to infection and, in addition to the receptor form, four immune-specific transcripts and proteins are produced.

Animals↗
PubMed1997

A diiodo-substituted 9-anthracenone.

The central ring of the anthrone system in 1,8-diiodo-10-hydroxy-10-(3-methylbut-3-en-1-ynyl)anthrac en-9(10H)-one, C19H12I2O2, has a boat conformation and the two outer rings form a dihedral angle of 41.1 (2) degrees. The I-C bond lengths are 2.094 (4) and 2.083 (4) A. The hydroxyl and carbonyl groups form an intermolecular hydrogen bond having an O...O distance of 2.853 (4) A.

Anthracenes↗