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Biomedical subjects

A Rodriguez

Publications and source records attributed to A Rodriguez.

At least 73 records · Page 4Linked to original sources
PubMed1999

Allogeneic bone marrow transplantation vs chemotherapy for the treatment of childhood acute lymphoblastic leukaemia in second complete remission (revisited 10 years on).

In 1989 we carried out a trial comparing allogeneic BMT to chemotherapy (CT) in 76 children with relapsed acute lymphoblastic leukaemia (ALL). Ten years on we have clinically revised outcome to firmly establish the role of each treatment, to analyse the importance of length of first remission and to provide long-term actuarial results for disease-free survival (DFS) and relapse rate in each group. For 21 patients within the transplantation group, probability of DFS and relapse are 42.8 +/- 10.8% and 40.2 +/- 11.7% (s.e.), respectively. In the chemotherapy group, probability of DFS is 10.0 +/- 4.74% (P = 0.001) and probability of relapse 87.5 +/- 5.2% (P = 0.0004). These results strongly reflect those at initial analysis, confirming a key role of BMT in the management of ALL in second remission. Moreover, on univariate analysis only two factors influenced DFS: treatment group and length of first complete remission (less or more than 30 months from first CR). Thus, it seems clear that the best therapeutic option in early relapse is BMT, whereas DFS in late relapse is at the limit of significance (P = 0.07), with a higher relapse rate in the CT group. Although encouraging results using intensified rotational combination chemotherapy have been published, prospective randomised studies are needed to assess with certainty the best therapeutic option in these patients.

Adolescent↗
PubMed1999

The re-emergence of American visceral leishmaniasis in an old focus in Venezuela. II. Vectors and parasites.

As part of an epidemiological study in an old focus of American Visceral Leishmaniasis (AVL) in Venezuela (Guayabita, Aragua State), a longitudinal entomological survey (January 1993-June 1994) was carried out. A total of 3,239 males and 6,043 females belonging to 11 phlebotomine sandfly species were collected. The two recognised vectors of AVL in the New World, Lutzomyia evansi and Lu. longipalpis were found to be sympatric. Lutzomyia evansi was the dominant species (86.4%), almost ten fold times more abundant than Lu. longipalpis (10.6%). The two species alternated seasonally: Lu evansi peaked at the end of the rainy season while Lu. longipalpis, almost virtually absent during such period, increased in the dry season. This species seems more greatly influenced by the temperature. Seven of 4,559 Lutzomyia evansi (0.15%) and one of 353 Lu. longipalpis (0.28%) were found positive for suprapyloric promastigotes. Using the polymerase chain reaction (PCR) with universal primers, all isolates were identified as Leishmania spp. Two cultures from Lu. evansi, IEVA/VE/93/UCNA-2 and IEVA/VE/93/UCNA-3, were established. k-DNA restriction analysis showed high homologies between these isolates and Leishmania chagasi. High hybridization signal with L. chagasi specific kDNA confirmed these results. These findings suggest that Lu. evansi may play a role as vector of visceral leishmaniasis in this area. The identity of the parasite carried by Lu. longipalpis needs to be confirmed.

Animals↗
PubMed1999

A Colombian family with X-linked juvenile retinoschisis with three affected females finding of a frameshift mutation.

X-linked retinoschisis (XLRS) is a vitreoretinal disease responsible for most cases of juvenile macular degeneration in males. Retinoschisis carrier females generally manifest no pathological symptoms. However, a large affected family from Colombia presented three affected females with typical RS phenotype similar to their 27 affected male relatives. Fundus examination as well as electroretinograms (ERG) indicate that the disease in these three affected females is as severe as in their affected male counterparts. DNA sequence analysis of the XLRS1 gene in the affected members of this family indicates a single base (G) deletion at the 639 base position (639delG). This deletion causes a frameshift during translation and results in a larger (235 amino acids) than normal peptide (224 amino acids) with grossly altered discoidin domain, which is considered critical for the cellular function of the protein. The co-segregation of this gene mutation with the RS phenotype and the RS carrier status as well as its complete absence in normal controls indicates that this genetic change is responsible for the RS pathology in this family. This (639delG) is a novel RS mutation and reported here for the first time. Furthermore, the analysis of the three affected females indicates that the RS pathology in affected females (a very rare occurrence) is due to XLRS1 mutations carried on both of their X chromosomes.

Adolescent↗
PubMed1999

Focused Assessment with Sonography for Trauma (FAST): results from an international consensus conference.

OBJECTIVE: To assemble an international panel of experts to develop consensus recommendations on selected important issues on the use of ultrasonography (US) in trauma care. SETTING: R Adams Cowley Shock Trauma Center, University of Maryland Medical System, Baltimore, Md. The conference was held on December 4, 1997. PARTICIPANTS: A committee of two co-directors and eight faculty members, in the disciplines of surgery and emergency medicine, representing four nations. Each faculty member had made significant contributions to the current understanding of US in trauma. RESULTS: Six broad topics felt to be controversial or to have wide variation in practice were discussed using the ad hoc process: (1) US nomenclature and technique; (2) US for organ-specific injury; (3) US scoring systems; (4) the meaning of positive and negative US studies; (5) US credentialing issues; and (6) future applications of US. Consensus recommendations were made when unanimous agreement was reached. Majority viewpoints and minority opinions are presented for unresolved issues. CONCLUSION: The consensus conference process fostered an international sharing of ideas. Continued communication is needed to advance the science and technology of US in trauma care.

Certification↗
PubMed1999

Entrapment and obstruction of the esophagus from thoracic spine hyperextension-dislocation injury.

We have reported a unique case of esophageal entrapment and obstruction from a thoracic spine hyperextension-dislocation injury after a motor vehicle crash. Because the risk for esophageal injury is not typically associated with thoracic spine injury, a heightened sensitivity for developing symptoms and signs is at least necessary. As with any injury to the gastrointestinal tract, optimal therapy requires resuscitation and prompt operative intervention.

Accidents, Traffic↗
PubMed1999

Characteristics of cartilage engineered from human pediatric auricular cartilage.

In the repair of cartilage defects, autologous tissue offers the advantage of lasting biocompatibility. The ability of bovine chondrocytes isolated from hyaline cartilage to generate tissue-engineered cartilage in a predetermined shape, such as a human ear, has been demonstrated; however, the potential of chondrocytes isolated from human elastic cartilage remains unknown. In this study, the authors examined the multiplication characteristics of human auricular chondrocytes and the ability of these cells to generate new elastic cartilage as a function of the length of time they are maintained in vitro. Human auricular cartilage, harvested from patients 5 to 17 years of age, was digested in collagenase, and the chondrocytes were isolated and cultured in vitro for up to 12 weeks. Cells were trypsinized, counted, and passaged every 2 weeks. Chondrocyte-polymer (polyglycolic acid) constructs were created at each passage and then implanted into athymic mice for 8 weeks. The ability of the cells to multiply in vitro and their ability to generate new cartilage as a function of the time they had been maintained in vitro were studied. A total of 31 experimental constructs from 12 patients were implanted and compared with a control group of constructs without chondrocytes. In parallel, a representative sample of cells was evaluated to determine the presence of collagen. The doubling rate of human auricular chondrocytes in vitro remained constant within the population studied. New tissue developed in 22 of 31 experimental implants. This tissue demonstrated the physical characteristics of auricular cartilage on gross inspection. Histologically, specimens exhibited dense cellularity and lacunae-containing cells embedded in a basophilic matrix. The specimens resembled immature cartilage and were partially devoid of the synthetic material of which the construct had been composed. Analyses for collagen, proteoglycans, and elastin were consistent with elastic cartilage. No cartilage was detected in the control implants. Human auricular chondrocytes multiply well in vitro and possess the ability to form new cartilage when seeded onto a three-dimensional scaffold. These growth characteristics might some day enable chondrocytes isolated from a small auricular biopsy to be expanded in vitro to generate a large, custom-shaped, autologous graft for clinical reconstruction of a cartilage defect, such as for congenital microtia.

Absorbable Implants↗
PubMed1999

Genetic dissection of cell growth arrest functions mediated by the Epstein-Barr virus lytic gene product, Zta.

Expression of the Epstein-Barr virus (EBV) latency-associated genes activates cell cycle progression and drives immortalization of the infected cell. In contrast, progression of the EBV replication program occurs most efficiently in growth-arrested cells. Previous studies showed that the EBV-encoded immediate-early transcription factor, Zta, can induce expression of the cyclin-dependent kinase inhibitors, p21 and p27, the tumor suppressor, p53, and cell growth arrest. Moreover, Zta-mediated induction of growth arrest occurs independently of its transcriptional transactivation function. Here we show that substitution of Zta's basic DNA binding domain with the analogous region of the Zta homologue, c-Fos, abrogates Zta's ability to induce growth arrest and to induce p21, p27, or p53 expression, suggesting that protein-protein interactions between this region of Zta and key cell cycle control proteins are involved in signaling cell cycle arrest. We also show that despite the crucial role for Zta's basic domain in eliciting cell growth arrest, its amino terminus is required for efficient induction of p27 and it modulates the level of p53 induction. Last, we provide evidence that Zta-mediated inductions of p21, p27, and p53 occur, at least in part, through distinct pathways. Therefore, Zta interacts with multiple growth arrest pathways, a property which may have evolved partly as a means to ensure that lytic replication occurs in a growth-arrested setting in multiple different tissues in various states of differentiation.

Amino Acid Sequence↗
PubMed1999

Hemoperitoneum as the sole indicator of abdominal visceral injuries: a potential limitation of screening abdominal US for trauma.

PURPOSE: To determine, at screening ultrasonography, the prevalence, severity, and clinical outcome of clinically important abdominal visceral injuries, without associated hemoperitoneum, that result from blunt abdominal trauma. MATERIALS AND METHODS: Computed tomography (CT) was performed at admission in 466 patients with visceral injury. A retrospective review was performed of findings from surgery and contrast material-enhanced spiral and conventional CT performed to verify abdominal visceral injuries in 467 (4%) of 11,188 patients with blunt trauma. These patients were admitted to a level 1 trauma center over 33 months to determine the presence of hemoperitoneum and to identify the grade of injury. Medical records of patients with abdominal visceral injury without hemoperitoneum were reviewed for the management required and for results of focused abdominal sonography for trauma (FAST). RESULTS: A total of 575 abdominal visceral injuries were identified at CT and/or surgery. Findings of CT at admission (n = 156) and of surgery (n = 1) revealed no evidence of hemoperitoneum in 157 (34%) patients with abdominal visceral injury; 26 (17%) of whom also had negative FAST studies. Abdominal visceral injuries diagnosed in patients without hemoperitoneum included 57 (27%) of 210 splenic injuries, 71 (34%) of 206 hepatic injuries, 30 (48%) of 63 renal injuries, four (11%) of 35 mesenteric injuries, and two (29%) of seven pancreatic injuries. Surgical and/or angiographic intervention was required in 26 (17%) patients without hemoperitoneum. CONCLUSION: Reliance on the presence of hemoperitoneum as the sole indicator of abdominal visceral injury limits the value of FAST as a screening diagnostic modality for patients who sustain blunt abdominal trauma.

Abdominal Injuries↗
PubMed1999

Secondary glaucoma in patients with uveitis.

PURPOSE: To evaluate the prevalence of secondary glaucoma (SG), clinical forms of uveitis more frequently associated with glaucoma, and describe the treatment and complications encountered in a cohort of patients with glaucoma and uveitis during a 10-year period. METHODS: The hospital records of patients with uveitis referred to the Immunology Service of the Massachusetts Eye and Ear Infirmary for a decade were reviewed for cases of SG. RESULTS: One hundred and twenty of the 1,254 patients (9.6%) with uveitis developed SG. SG was more frequent in anterior uveitis (67%) but was also associated with posterior uveitis (13%) and pars planitis (4%). Herpetic keratouveitis (22%), Fuchs' iridocyclitis (19%), juvenile rheumatoid arthritis-associated iridocyclitis (16%), syphilis (14%), and sarcoidosis (12%) were the leading types of uveitis associated with SG. Despite aggressive medical and surgical therapy, SG was associated with progressive visual field loss and optic nerve damage in 39 patients (33%). CONCLUSION: SG is an underappreciated, vision-threatening complication in patients with uveitis. Increased vigilance for emergence of this complicating problem during the care of patients with uveitis is warranted, and medical and surgical treatment for reducing IOP should be especially aggressive in these patients. We hypothesize that earlier, more aggressive treatment of uveitis will reduce the presence of glaucoma as an additional vision-robbing complication of uveitis.

Adolescent↗
PubMed1999

Novel effects of the acyl-coenzyme A:Cholesterol acyltransferase inhibitor 58-035 on foam cell development in primary human monocyte-derived macrophages.

We examined the effect of acyl-coenzyme A:cholesterol acyltransferase (ACAT) inhibitors on intracellular cholesterol stores in primary human monocyte-derived macrophages (HMMs) during foam cell formation. HMMs were exposed to acetylated low density lipoprotein (acLDL, 500 microg protein per mL) with or without 58-035 (1 to 10 microg/mL) or CI-976 (2 microg/mL) for 2 to 48 hours. Total cholesterol (TC) and esterified cholesterol (EC) mass was significantly lower while unesterified cholesterol (UC) increased slightly in cells incubated with acLDL plus ACAT inhibitors. Sterol mass was also measured in cells coincubated with acLDL (500 microg protein per mL) with or without 58-035 (2 microg/mL), high density lipoprotein (HDL, 400 microg protein per mL), or HDL+58-035 for 48 hours. TC and EC were 23% and 55% lower, respectively (P<0.0004), while UC was 11% higher (P<0.04) in cells incubated with acLDL plus 58-035. In contrast, coincubation with HDL alone did not significantly affect TC, EC, or UC mass compared with acLDL alone. The effect of 58-035 could not be explained by cytotoxicity, because adenine release, secreted lactate dehydrogenase, glucose utilization, and cell protein were similar in cells exposed to acLDL regardless of the presence of 58-035. We investigated several potential mechanisms for the decreased TC mass, including increased UC efflux and decreased acLDL binding and uptake. Efflux was measured in cells exposed to [1,2-(3)H]cholesteryl oleate-labeled acLDL, unlabeled control acLDL, and native untreated acLDL (500 microg protein per mL) with or without 58-035 (5 microg/mL) for 24 or 48 hours. UC efflux increased in a time-dependent manner from cells exposed to acLDL plus 58-035 compared with cells exposed to acLDL alone (P<0. 04). High-affinity binding was measured in cells exposed to (125)I-acLDL (5 microg protein per mL) with or without excess unlabeled acLDL (100 or 500 microg protein per mL) for 4 hours at 4 degrees C. Specific acLDL binding, uptake, and total degradation were significantly lower when 58-035 was present during cholesterol enrichment compared with cells exposed to acLDL alone (P<0.001). Unlike the effects of ACAT inhibitors on foam cell formation in rodent macrophages, these compounds lowered TC accumulation in HMMs during foam cell formation by limiting the uptake of acLDL and enhancing UC efflux. They may offer promise as drug therapies for atherosclerosis.

Amides↗
PubMed1999

Paediatric life support instructors courses in Spain. Spanish Paediatric and Neonatal Resuscitation Group.

Between October 1996 and February 1998 we have provided five PLS instructors courses for 127 physicians. The instructor course takes 20-24 h over in 3 days, with 20-36 students per course. Theory classes last 5 h and practical stations between 14 and 18 h. Theory classes include: types and organisation of paediatric courses, resuscitation material, methodology of education, didactic methods, and methods of evaluation. The practical classes include techniques of oral expression, resuscitation material, and methodology, and evaluation of basic life support, airway and ventilation, venous and intraosseous access, diagnosis and treatment of arrythmias, neonatal resuscitation and advanced resuscitation. At the end of the course the students perform an anonymous written evaluation of the course with scores between 1 (very bad), 2, 3, 4 and 5 (very good). Theoretical aspects practical classes, methodology, and organisation of the PLS instructors courses are considered satisfactory by the students. We conclude that PLS instructors courses are important for assuring the uniformity and quality of paediatric life support courses.

Cardiopulmonary Resuscitation↗
PubMed1998

Comparison between a lyse-and-then-wash method and a lyse-non-wash technique for the enumeration of CD34+ hematopoietic progenitor cells.

The flow cytometric enumeration of CD34+ hemopoietic precursor cells (HPC) present in samples used for transplantation of HPC has proven to be the most powerful single parameter for prediction of engraftment. At present, several different methodological approaches are used for the flow cytometric enumeration of CD34+ HPC. In the present study we have compared two of these methods as regards enumeration of CD34+ HPC and their CD34+/CD19- and CD34+/CD19+ subsets: a lyse-non-wash procedure based on the use of a recently commercialized red cell lysing solution (Quicklysis, Cytognos, Salamanca, Spain) and a lyse-and-then-wash method in which the Becton Dickinson (San Jose, CA) FACS Lysing Solution was used. For that purpose a total of 52 samples corresponding to 20 G-CSF mobilized peripheral blood (PB) samples and 21 PB-derived leucapheresis products from patients undergoing autologous PB stem cell harvest, together with 11 bone marrow (BM) samples from healthy volunteers were analyzed. Our results show that for each of the three types of samples analyzed the use of the lyse-and-then-wash method is associated with significantly lower numbers of both total CD34+ HPC (P < or = 0.003) and its major CD34+/CD19- subset (P < or = 0.01) while no significant changes are detected in the number of CD34+/CD19+ HPC in BM samples (P > 0.05). The use of an internal standard (reference beads) added just prior to data acquisition, showed that the differences between both methods are due to a selective loss of CD34+ HPC and its major CD34+/CD19- subset in BM (P=0.002 and P=0.003), PB (P < 0.0001 and P < 0.0001) and PB-derived leucapheresis products (P < 0.0001 and P=0.0001). Finally, addition of a centrifugation and washing step to a group of 11 leucapheresis samples lysed with Quicklysis showed that they did not significantly affect the overall number of total CD34+, CD34+/CD19- and CD34+/CD19+ HPC obtained. In line with these findings elimination of centrifugation and washing steps when FACS Lysing Solution was used to lyse mature red cells almost corrected for the selective loss of CD34+ HPC. In spite of these differences a significant degree of correlation (r > 0.83 in all cases) was found between both methods regarding the total number of CD34+, CD34+/CD19- and CD34+/CD19+ HPC present in the BM, PB and PB-derived leucapheresis samples analyzed in this study.

Antigens, CD19↗
PubMed1998

Application of gas and liquid chromatography-mass spectrometry to the evaluation of pirimiphos methyl degradation products in industrial water under ozone treatment.

The organophosphorus compound pirimiphos methyl was oxidized in water under ozonolysis in the presence of formulating agents. A rapid sample handling procedure was developed based on liquid-solid extraction with nonporous carbon cartridges. This sorbent material allowed recovery of the polar degradation products (DPs). Analysis of oxidized solutions was performed with both GC-ion trap (IT)-MS using either electron impact or chemical ionization as ionization modes and LC-atmospheric pressure ionization (API)-MS using either an ionspray (ISP) or an atmospheric pressure chemical ionization (APCI) interface in order to confirm the presence of DPs. The performances of both technologies were evaluated for structure elucidation and quantitation by using pirimiphos methyl, 2,4-aminophenol and cyanuric acid as external standards of DPs. LC-API-MS techniques allowed the detection of six DPs, of which two were not detected by GC-IT-MS techniques, even after a derivatization procedure with BF3-MeOH reagent. ISP was the most suitable ionization method for identifying the DPs, because sodium or potassium adduct ions were of great help in confirming the molecular mass of unknowns. APCI provided more fragmentation patterns than ISP. However unequivocal identification of all DPs was impossible and only a tentative degradation pathway of pirimiphos methyl in water under ozone is proposed. At the end of the reaction time, DPs accounted for between 70 and 85% of the initial concentration of methyl pirimiphos.

Chromatography, Liquid↗
PubMed1998

Dredd, a novel effector of the apoptosis activators reaper, grim, and hid in Drosophila.

Caspases are widely conserved proteases considered to be essential effectors of apoptosis. We identified a novel Drosophila gene, dredd, which shares extensive homology to all members of the caspase gene family. Cells specified for programmed death in development exhibit a striking accumulation of dredd RNA that requires signaling by the death activators REAPER, GRIM, and HID. Furthermore, directed misexpression of each activator was sufficient to drive ectopic accumulation of dredd RNA. Heterozygosity at the dredd locus suppressed apoptosis in transgenic models of reaper- and grim-induced cell killing, demonstrating that levels of dredd product can modulate signaling triggered by these death activators. Finally, expression of REAPER, GRIM, and HID was found to trigger processing of DREDD protein precursor through a mechanism that is insensitive to, and upstream of, known caspase inhibitors. Taken together, these observations establish mechanistic connections between activators of apoptosis and a new downstream death effector in Drosophila.

Amino Acid Sequence↗
PubMed1998

9-Hydroxy-9-(3-methylbut-3-en-1-ynyl)-9H-fluorene-1-carbonitrile.

The N atom in the title compound, C19H13NO, lies -0.0365 (14) A from the plane formed by the fluorene system, and the C [symbol: see text] N distance is 1.143 (2) A. The C [symbol: see text] C distance is 1.191 (2) A, and the ethynyl group deviates slightly from linearity, with C-C [symbol: see text] C-C bond angles of 172.0 (1) and 176.1 (2) degrees. Terminal CH2 and CH3 groups are 50:50 disordered, with equal C-C distances of 1.408 (3) and 1.406 (3) A.

Crystallography, X-Ray↗
PubMed1998

Strategies to decrease costs associated with GBS prophylaxis in preterm gestations.

Objective: 1) To evaluate the costs associated with a practice of routinely culturing women for Group B beta-Streptococcus (GBS) who are at risk for preterm delivery. 2) To evaluate the charges associated with a policy of empiric antibiotic therapy in women suspected of imminent delivery prior to 37 weeks gestation.Methods: In our hospital, women who present with preterm contractions (PTC), preterm labor (defined as uterine contractions resulting in cervical change, PTL), and preterm rupture of the membranes (PROM) were cultured for GBS. Women with PTL and PROM received parenteral antibiotic therapy pending availability of culture results (48 hours). We reviewed the records of women who participated in a study to determine the sensitivity and specificity of a rapid test for GBS (Am J Obstet Gynecol 1997;176:S35). Results of the Lim broth culture, our gold standard, were used for this analysis. The charges for performing cultures ($32/culture) and administering intravenous ampicillin ($54/dose) were calculated.Results: There were 118 women with PTC, 52 women with PTL, and 64 with PROM. Thirty-four (14.5%) of the cultures were positive. The results are presented below.In women with PTC, the incidence of GBS was 12.7%. The culture results were available and guided care in only the 6 women who delivered between 2 and 7 days. In women with PTL the incidence of positive cultures was 11.5%. All of the women received antibiotics pending results of cultures. The majority of the women had delivery delayed 48 hours until results were available. Care was modified in the 7 women who delivered between 2 and 7 days. In women with PROM the incidence of GBS was 20.3%. The culture results were available and guided therapy in 11 women.Conclusions: Our findings suggest that GBS cultures have limited clinical value in women with PTC. Only 6 women, 5.5%, had their care modified as a result of the cultures, at a cost of $3776. In women with PTL, we over-treated the majority of women with antibiotics, most of whom delivered after culture results were available. Cultures had minimal impact on management. Antibiotics should be reserved for women whose labor is progressing on tocolysis. In women with PROM, most delivered prior to availability of culture results. We would have saved $2048 had no cultures been obtained. These results are probably irrelevant, if routine antibiotic administration is utilized in PROM to prolong latency intervals regardless of GBS status.

Journal Article↗
PubMed1998

4-Nitro-1-(trimethylsilylethynyl)benzene.

The title molecule, C11H13NO2Si, lies on a mirror plane, with only one methyl group lying out of plane. The C[symbol: see text]C triple bond has a length of 1.199 (4) A. Bond angles Si-C[symbol: see text]C and C[symbol: see text]C-C(Ar) are 177.9 (3) and 178.0 (3) degrees, respectively. The Si-Csp3 bond lengths are 1.831 (4) and 1.838 (3) A, while the Si-Csp distance is 1.839 (3) A.

Crystallography, X-Ray↗