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1.
Vox Sang ; 106(2): 103-10, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23909571

RESUMEN

BACKGROUND: The ability of a new generation commercial, multiplex, multi-dye test from Roche, the cobas TaqScreen MPX test, version 2.0, to detect and identify occult HBV infections was evaluated using routine donor samples from Kaohsiung Blood Bank, Taiwan. STUDY DESIGN AND METHODS: A total of 5973 samples were tested by nucleic acid amplification technology (NAT); 5898 in pools of six, 66 in pools of less than six and nine samples individually. NAT-reactive samples were retested with alternative NAT tests, and follow-up samples from the donors were tested individually by NAT and for all the HBV serological markers. RESULTS: Eight NAT-only-reactive donors were identified, and follow-up samples were obtained from six of the donors. The results indicated that all eight donors had an occult HBV infection with viral loads <12 IU/ml. CONCLUSION: The cobas(®) TaqScreen MPX test, version 2.0, has an advantage over the current Roche blood screening test, the cobas TaqScreen MPX test, for screening donations in countries with a high prevalence of occult HBV infections since the uncertainty associated with identifying samples with very low viremia is removed by the ability of the test to identify the viral target in samples that are reactive with the cobas TaqScreen MPX test, version 2.0.


Asunto(s)
Donantes de Sangre , Virus de la Hepatitis B/aislamiento & purificación , Técnicas de Amplificación de Ácido Nucleico/métodos , ADN Viral/sangre , Virus de la Hepatitis B/genética , Humanos , Tamizaje Masivo/métodos , Pruebas Serológicas , Taiwán
2.
Transfus Med ; 21(2): 84-9, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21092013

RESUMEN

BACKGROUND AND OBJECTIVE: Individuals with p phenotype lack P1, P(k) and P antigens on red blood cells, presumably as a result of deficiency in the enzyme α(1,4)galactosyltransferase (A4GALT). The aim of this study was to explore the molecular background of a Taiwanese family with p phenotype. MATERIALS AND METHODS: Blood samples from two p siblings and seven family members were investigated. The coding region of the A4GALT gene was analysed by polymerase chain reaction and direct sequencing. The wild- and mutant-complementary DNAs (cDNAs) of A4GALT were cloned into an expression vector and transfected to Chinese hamster ovary (CHO) cells. P(k) expression on the transfected cells was analysed by flow cytometry and the activities of A4GALT were measured by high-performance liquid chromatography. RESULTS: The two individuals with p phenotype were homozygous for the complex mutation, which was caused by a combined deletion and insertion between nt 418 and 428. No expression of P(k) and no enzyme activity were observed in cells transfected with the mutant construct. CONCLUSION: The first case of p phenotype in Taiwan was caused by a non-functional allele resulting from a homozygous complex mutation of A4GALT gene.


Asunto(s)
Galactosiltransferasas/genética , Sistema del Grupo Sanguíneo P/genética , Alelos , Animales , Células CHO , Cricetinae , Cricetulus , Análisis Mutacional de ADN , ADN Complementario/genética , Femenino , Galactosiltransferasas/deficiencia , Humanos , Masculino , Mutagénesis Insercional , Linaje , Fenotipo , Eliminación de Secuencia , Taiwán , Transfección
3.
Transfus Med ; 21(5): 318-24, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21707797

RESUMEN

AIMS/OBJECTIVES: The purpose of this study was to explore the molecular basis of the K0 phenotype of a Taiwanese blood donor found to have anti-Ku alloantibodies. BACKGROUND: With respect to Kell blood group antigens, almost all Taiwanese have the (K-, k+) phenotype. MATERIALS AND METHODS: Alloantibody identification and KEL antigen typing were performed. Enzymatic function assays were carried out to detect the Kell glycoprotein on RBCs. The KEL genes were sequenced to detect genetic variation. To determine the origin of this novel allele, family studies were conducted. RESULTS: The alloantibody was identified as anti-Ku. The donor was typed K0 . The KEL gene-sequencing data revealed that this K0 donor is a compound heterozygote with two different null alleles. He bears a novel 730delG mutation in one allele. Family studies suggested that the donor inherited the 730delG mutation from his father. The endothelin-converting activity assay indicated that his RBCs had no functional Kell glycoprotein. Other family members who had only one null allele with the 730delG mutation had the phenotype (K-, k+). CONCLUSION: For blood transfusion safety, it is important to establish an effective screening algorithm to identify rare phenotypes, such as the K0 phenotype, and to establish a database of rare blood groups.


Asunto(s)
Donantes de Sangre , Sistema del Grupo Sanguíneo de Kell/genética , Mutación , Transfusión Sanguínea/normas , Análisis Mutacional de ADN , Familia , Heterocigoto , Humanos , Isoanticuerpos/sangre , Fenotipo , Taiwán
4.
Transfus Med ; 21(1): 33-41, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-20726954

RESUMEN

OBJECTIVES: A look-back study was conducted to determine the clinical significance of occult hepatitis B virus (HBV) blood transfusion in an HBV hyperendemic area. AIM: To improve the blood transfusion safety. BACKGROUND: Occult HBV is transmissible through blood transfusion in HBV-naÏve recipients. However, its impact on recipients with prevalent HBV infection in HBV hyperendemic areas is unclear. METHODS/MATERIALS: In 2006, 12 occult HBV blood donors were found from 10 824 repository samples by nucleic acid testing. The 74 corresponding recipients were identified and their pre- and post-transfusion clinical information was gathered, and the living recipients were recalled for follow-up. From the available archival sera, the HBV DNA was examined and sub-genomic sequences between paired donor and recipient were compared using polymerase chain reaction-based assays. RESULTS: Among the 74 recipients, 18 were still alive and 12 returned to our clinic. From the available serological profiles, 76% of recipients had ongoing or recovered HBV infection before transfusion. Only 24 recipients had available post-transfusion serological profiles and none seroconverted to be hepatitis B surface antigen (HBsAg) positive. Moreover, except for the prior HBsAg carriers, the recipients' HBV DNA levels after transfusion were low (<20 IU/mL). One recipient had identical HBV surface gene sub-genomic sequence (384 nucleotides) to his donor. After transfusion, no recipient developed post-transfusion hepatitis (PTH) and the clinical outcome was good. CONCLUSION: In HBV hyperendemic areas, occult hepatitis B transfusion might not lead to HBsAg carriage or PTH. The risk of transfusion-transmitted HBV infection was probably lower than that in non-endemic areas because most recipients had already experienced HBV infection.


Asunto(s)
Enfermedades Endémicas , Virus de la Hepatitis B/aislamiento & purificación , Hepatitis B/transmisión , Reacción a la Transfusión , Adulto , ADN Viral/sangre , Femenino , Hepatitis B/epidemiología , Antígenos de Superficie de la Hepatitis B/sangre , Humanos , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Prevalencia , Estudios Retrospectivos , Taiwán
5.
Leukemia ; 20(1): 136-41, 2006 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-16281075

RESUMEN

To improve treatment results for children with de novo acute myeloid leukemia (AML), we introduced a novel protocol, Taiwan Pediatric Oncology Group-AML-97A, for AML other than acute promyelocytic leukemia (APL), for which modified conventional protocols were used. From January 1, 1997, to December 31, 2002, 141 children younger than 17 years old with de novo AML were enrolled. In total, 117 patients with non-APL AML were treated with induction therapy of idarubicin and cytarabine (Ara-C), postremission therapy with high-dose Ara-C - containing regimens for four monthly courses, and moderate-dose therapy with idarubicin and Ara-C for four monthly courses. The first 19 patients with APL were treated with all-trans retinoic acid, idarubicin and Ara-C, with the remaining five patients receiving all-trans retinoic acid and idarubicin, followed by maintenance therapy for 2 years. Stem cell transplantation was performed in 29 patients in first remission with a similar outcome as chemotherapy alone. The remission rate in the AML-97A study was 90%, the 5-year survival 51 +/- 5.3% (s.e.) and the 5-year event-free survival 50 +/- 4.8%; for APL, these were 100%, 86 +/- 7.0, and 75 +/- 9.8%. For the whole group, the 5-year survival was 57 +/- 4.7% and the 5-year event-free survival 54 +/- 4.4%. The AML-97A regimen was well tolerated.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Leucemia Mieloide Aguda/terapia , Leucemia Promielocítica Aguda/terapia , Trasplante de Células Madre , Adolescente , Niño , Preescolar , Supervivencia sin Enfermedad , Femenino , Estudios de Seguimiento , Humanos , Lactante , Recién Nacido , Masculino , Inducción de Remisión , Taiwán , Resultado del Tratamiento
6.
Leukemia ; 13(10): 1506-12, 1999 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-10516750

RESUMEN

Acute myeloid leukemia (AML) with minimal differentiation was usually referred to as acute undifferentiated leukemia in the past. With the help of immunophenotyping, this subtype of leukemia was shown to express myeloid antigens on the blasts and was designated AML-M0 by FAB Cooperative Study Group in 1991. Among the 423 consecutive newly diagnosed de novo AML at our institution, 12 (2.8%) were of M0 subtype. The proportion of M0 in AML was higher in children than in adults (8.2% vs 1.7%). Four other M0 patients referred from outside hospitals for immunophenotyping were also included in this study. There were two peaks in age distribution of these 16 patients: less than 3 years and between 51 and 70 years, respectively. Organomegaly was more common in patients with AML-M0 than in those with other subtypes (56.3% vs 29.2%, P = 0.025). The former patients had higher incidences of CD7 and CD34 expression on the leukemic cells than the latter ones (50% vs 16.9%, P = 0.003 and 69.2% vs 37.9%, P = 0.019, respectively). The patients with AML-M0 showed more frequent clonal chromosomal abnormalities in the leukemic cells than other AML patients (83.3% vs 53.9%, P = 0.039); the same is also true for complex cytogenetic aberrations (50% vs 11. 4%, P = 0.004). Adults with AML-M0 showed a lower complete remission (CR) rate and significantly poorer survival than those with non M0-AML. However there was no significant difference in outcome between the two groups of pediatric patients. In conclusion, AML-M0 is a unique subtype of leukemia that has distinct age distribution and shows different clinical and biological characteristics from other AML. Adult patients have poor prognosis. Whether pediatric patients had better outcome than adults needs to be clarified in further studies.


Asunto(s)
Leucemia Mieloide/patología , Enfermedad Aguda , Adolescente , Anciano , Diferenciación Celular/fisiología , Niño , Preescolar , Análisis Citogenético , Femenino , Reordenamiento Génico , Humanos , Inmunofenotipificación , Lactante , Leucemia Mieloide/genética , Masculino , Persona de Mediana Edad , Taiwán , Resultado del Tratamiento
7.
Leukemia ; 6(9): 907-14, 1992 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-1325582

RESUMEN

Philadelphia chromosome (Ph') was detected at presentation in 10 out of 110 patients with acute lymphoblastic leukemia (ALL) and five of 168 patients with acute myelogenous leukemia (AML). Two other ALL patients who had studies at relapse were also included in the analyses. One of the 12 Ph'-positive (Ph+) ALL patients had simultaneous expression of myeloid-associated antigen on the leukemic blasts, while all the five AML patients coexpressed markers of lymphoid cells. Double labeling of the cells with myeloperoxidase and CD10 on three Ph+ AML cases showed that most leukemic blasts expressed either myeloperoxidase activity or CD10 but not both. Cross-lineage gene rearrangements of T-cell receptor (TCR) beta-chain gene were detected in three of the eight Ph+ ALL patients tested. All the four Ph+ AML cases studied showed immunoglobulin heavy chain gene rearrangements, and three of them also had simultaneous rearrangements of TCR beta-chain gene. The results revealed that Ph+ acute leukemia in this study belonged either to ALL or mixed lineage leukemia, and none was pure AML. This finding is contrary to that of acute blast crisis of chronic myelogenous leukemia in which the majority of patients had myeloid transformation. Rearrangements of bcr were detected in four of the 10 Ph+ ALL and three of the four Ph+ AML patients tested. No significant difference was noted in the clinical or hematologic manifestations among Ph+ leukemia with or without bcr rearrangements.


Asunto(s)
Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Leucemia Mieloide Aguda/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Adulto , Anciano , Antígenos de Diferenciación/metabolismo , Antígenos de Neoplasias/metabolismo , Niño , Preescolar , Femenino , Reordenamiento Génico de Cadena Pesada de Linfocito B , Reordenamiento Génico de la Cadena beta de los Receptores de Antígenos de los Linfocitos T , Humanos , Inmunohistoquímica , Inmunofenotipificación , Cariotipificación , Leucemia Mielógena Crónica BCR-ABL Positiva/enzimología , Leucemia Mielógena Crónica BCR-ABL Positiva/inmunología , Leucemia Mieloide Aguda/enzimología , Leucemia Mieloide Aguda/inmunología , Masculino , Persona de Mediana Edad , Neprilisina , Peroxidasa/metabolismo , Cromosoma Filadelfia , Leucemia-Linfoma Linfoblástico de Células Precursoras/enzimología , Leucemia-Linfoma Linfoblástico de Células Precursoras/inmunología
8.
Leukemia ; 13(2): 155-60, 1999 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-10025887

RESUMEN

The relative efficacy and toxicity of E. coli L-asparaginase and epidoxorubicin used in remission induction therapy for childhood acute lymphoblastic leukemia (ALL) were assessed in a randomized trial conducted in Taiwan. All patients had standard-risk ALL, defined as a leukocyte count <10 x 10(9)/l and were aged between 1 and 2 or 7 and 10 years, or a leukocyte count <50 x 10(9)/l and were aged between 2 and 7 years, without evidence of a T cell or mature B cell immunophenotype, central nervous system leukemia or expression of two or more myeloid-associated antigens. Ninety-three patients were randomized to receive E. coli L-asparaginase at 10,000 IU/m2 thrice weekly for nine doses and 108 to receive epidoxorubicin at 20 mg/m2 weekly for two doses during remission induction with daily prednisolone, weekly vincristine and, on day 22, a dose of etoposide plus cytarabine. Patients treated with L-asparaginase had a significantly higher rate of fatal infection with or without hemorrhage than did those who received epidoxorubicin during remission induction (six of 93 vs none of 108, P = 0.009), resulting in a lower rate of complete remission in the former group (93.6 vs 99.1%, P = 0.05). In addition, patients treated with L-asparaginase had a higher frequency of hyperglycemia and hypoalbuminemia. The overall rate of event-free survival was lower in patients treated with L-asparaginase than in other patients (P = 0.06); estimated 3-year rates were 72% (95% confidence interval, 55-89%) and 87.2% (78-96%), respectively. We conclude that L-asparaginase (Leunase) given at 10,000 IU/m2 for nine doses was poorly tolerated and resulted in excessive toxicity, both through its effects as a single agent and possibly through potentiation of etoposide.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Asparaginasa/efectos adversos , Escherichia coli/enzimología , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Inducción de Remisión/métodos , Adolescente , Niño , Preescolar , Epirrubicina/efectos adversos , Femenino , Humanos , Lactante , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidad , Taiwán/epidemiología
9.
Leukemia ; 14(6): 1025-30, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10865968

RESUMEN

MLL gene rearrangements are associated with coexpression of myeloid- and lymphoid-associated antigens on leukemic blasts and a dismal outcome in acute lymphoblastic leukemia (ALL). Whether the same conditions can apply to acute myeloid leukemia (AML) is not quite clear. Rearrangements of the MLL gene were analyzed on 113 patients with newly diagnosed de novo AML in a single institution. Sixteen (14%) of them showed rearranged bands by Southern blot analysis, including three (50%) of six infants, three (14%) of 21 children between 1 and 15 years and 10 (12%) of 86 adults. MLL rearrangements were not only detected in M5 (four of 12 patients, 33%) and M4 (six of 31, 19%) subtypes but also in other non-M4-M5 AML (six of 70, 9%), including M1, M2 and M7, but not M3 subtype. Seven patients had chromosomal abnormalities involving 11q23, but nine did not. The latter comprised three (6%) of 48 patients with normal karyotype, one with t(8;21), none with t(15;17), inv(16) or t(9;22), and four (15%) of 27 with cytogenetic aberrations other than those specific structural abnormalities. In contrast to ALL, AML patients with MLL rearrangements did not tend to coexpress lymphoid- and myeloid-associated antigens simultaneously on leukemic blasts and have similar outcome as those without the gene rearrangements.


Asunto(s)
Proteínas de Unión al ADN/genética , Reordenamiento Génico , Leucemia Mieloide/genética , Proto-Oncogenes , Factores de Transcripción , Enfermedad Aguda , Adolescente , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Niño , Preescolar , Reordenamiento Génico de la Cadena beta de los Receptores de Antígenos de los Linfocitos T , Genes de Inmunoglobulinas , N-Metiltransferasa de Histona-Lisina , Humanos , Inmunofenotipificación , Lactante , Leucemia Mieloide/tratamiento farmacológico , Leucemia Mieloide/inmunología , Proteína de la Leucemia Mieloide-Linfoide , Análisis de Supervivencia , Resultado del Tratamiento
10.
Diabetes Care ; 24(5): 850-4, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11347742

RESUMEN

OBJECTIVE: To study the prevalence of and risk factors for abnormal glucose tolerance in transfusion-dependent beta-thalassemic patients. RESEARCH DESIGN AND METHODS: A total of 89 transfusion-dependent beta-thalassemic patients were interviewed. Diabetes was previously diagnosed in 14 of them. In the remaining 75 patients, 68 participated in an oral glucose tolerance test. Potential risk factors were identified using the independent t test, chi2 test, and Fisher's exact test. Logistic regression analysis was used to select the independent risk factors that best predicted abnormal glucose tolerance A two-tailed P value of <0.05 was considered to be statistically significant. RESULTS: The prevalence of impaired glucose tolerance was 8.5% (7 of 82) and that of diabetes was 19.5% (16 of 82). Presentation with diabetic ketoacidosis was 31.1% (5 of 16). The risk factors for abnormal glucose tolerance found in transfusion-dependent beta-thalassemic patients were serum ferritin concentration and hepatitis C infection. CONCLUSIONS: The interaction of iron overload and hepatitis C infection worsened the prognosis of thalassemic patients. Aggressive iron-chelation therapy as well as prevention and treatment of hepatitis C infection should be mandatory in managing glucose homeostasis in transfusion-dependent beta-thalassemic patients in Taiwan.


Asunto(s)
Transfusión Sanguínea , Intolerancia a la Glucosa/epidemiología , Talasemia beta/sangre , Talasemia beta/terapia , Adolescente , Adulto , Niño , Diabetes Mellitus/epidemiología , Femenino , Ferritinas/sangre , Hepatitis B/epidemiología , Hepatitis C/epidemiología , Humanos , Quelantes del Hierro/uso terapéutico , Masculino , Cooperación del Paciente , Prevalencia , Factores de Riesgo , Taiwán , Talasemia beta/complicaciones
11.
Bone Marrow Transplant ; 1(2): 115-20, 1986 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-3332127

RESUMEN

Ten patients with homozygous beta thalassemia, aged from 1 year 7 months to 13 years, underwent bone marrow transplantation from siblings or parents. The first case received 12 mg/kg busulfan, 120 mg/kg cyclophosphamide, and 300 cGy total body irradiation before transplantation; he survives, with a graft, more than 680 days after transplantation. The other nine patients received 16 mg/kg busulfan and 200 mg/kg cyclophosphamide. Two died of transplantation-related complications on days 30 and 55. Seven survive 170 to 580 days after transplantation. Three of the seven surviving patients have durable engraftment (greater than 230 to greater than 550 days) while four patients have autologous hematopoietic recovery. Four of five patients who had less than 50 prior transfusions achieved engraftment. Only one of five patients who had more than 50 prior transfusions achieved engraftment (P less than 0.05). The six-month actuarial survival was 80%; six-month actuarial disease-free survival was 40%. These data demonstrate that bone marrow transplantation may cure thalassemia, but engraftment may be jeopardized among patients who have been heavily transfused or have received marrow from a donor who is not HLA-identical.


Asunto(s)
Trasplante de Médula Ósea , Talasemia/cirugía , Análisis Actuarial , Adolescente , Niño , Preescolar , Femenino , Rechazo de Injerto , Supervivencia de Injerto , Humanos , Lactante , Masculino , Quimera por Radiación , Factores de Riesgo , Relaciones entre Hermanos , Talasemia/genética , Talasemia/mortalidad
12.
Am J Clin Pathol ; 96(2): 171-6, 1991 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-1650532

RESUMEN

Ten cases of pediatric fulminant hemophagocytic syndrome, encountered between 1986 and 1989, are described. They occurred in the summer, and the patients presented with fever, jaundice, hepatosplenomegaly, pancytopenia, coagulopathy, and abnormal liver function. Bone marrow studies revealed infiltration by atypical T-lymphoid cells, rare B immunoblasts, and mature histiocytes with hemophagocytosis. Initially, histiocytic medullary reticulosis was suspected in six cases. The clinical course was characterized by rapid deterioration, with a mean period of 16 days from onset of fever to death. The main causes of death were coagulopathy with multiple organ failure and opportunistic infection. In seven of eight cases studied by serologic assay and Southern blot hybridization, acute or active Epstein-Barr virus (EBV) infection was documented. It is suggested that an atypical or fulminant form of primary EBV infection distinct from classic infectious mononucleosis was prevalent in previously healthy children in Taiwan. Younger age involvement and seasonal clustering were characteristic of the disorder described.


Asunto(s)
Herpesvirus Humano 4 , Sarcoma Histiocítico/diagnóstico , Histiocitosis de Células no Langerhans/diagnóstico , Infecciones Tumorales por Virus/clasificación , Recuento de Células Sanguíneas , Southern Blotting , Médula Ósea/patología , Diagnóstico Diferencial , Femenino , Histiocitosis de Células no Langerhans/clasificación , Histiocitosis de Células no Langerhans/patología , Humanos , Lactante , Hígado/patología , Masculino , Pruebas Serológicas , Infecciones Tumorales por Virus/diagnóstico
13.
J Biomed Sci ; 1(1): 13-18, 1994 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11725002

RESUMEN

In adult male Sprague-Dawley rats anesthetized with pentobarbital sodium, we elucidated the molecular consequence of central alpha(2)-adrenoceptor activation. The hypotensive and negative chronotropic and inotropic actions of the alpha(2)-adrenoceptor agonist guanabenz were used as our experimental index. Intracerebroventricular administration of pertussis toxin (2.5 &mgr;g) significantly attenuated the cardiovascular suppressant effects of the aminoguanidine compound (100 &mgr;g/kg i.v.). However, application of N-ethylmaleimide (0.125 or 0.250 &mgr;g), phorbol 12-myristate 13-acetate (1.25 or 2.50 &mgr;g), cholera toxin (1.25 or 2.50 &mgr;g) or forskolin (12.5 or 25.0 &mgr;g) into the lateral cerebral ventricle elicited no appreciable blunting effect on the circulatory depression produced by guanabenz. These results were essentially duplicated when pertussis toxin (0.125 or 0.250 &mgr;g), N-ethylmaleimide (0.0125 or 0.05 &mgr;g), phorbol 12-myristate 13-acetate (0.125 or 0.25 &mgr;g), cholera toxin (0.125 or 0.25 &mgr;g) or forskolin (1.25 or 2.50 &mgr;g) was microinjected bilaterally to the nucleus reticularis gigantocellularis, a medullary site believed to be intimately related to the antihypertensive action of guanabenz. These findings suggest that stimulation of the alpha(2)-adrenoceptors in the medulla oblongata may result in the activation of a pertussis toxin-sensitive GTP-binding regulatory protein. They further suggest that the biologic signals subsequent to this action may not be linked to Gs, Gi or Gp but possibly Go. Copyright 1994 S. Karger AG, Basel

14.
Regul Pept ; 37(2): 167-80, 1992 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-1539113

RESUMEN

We evaluated the molecular mechanism that may underlie the suppressive effect of neurotensin (NT) on the baroreceptor reflex (BRR), using Sprague-Dawley rats that were anesthetized with sodium pentobarbital (50 mg/kg, i.p.). Intracerebroventricular (i.c.v.) application of NT (15 nmol) significantly inhibited the BRR response. Such an inhibition was appreciably antagonized by pretreating animals with i.c.v. injection of pertussis toxin (10 or 20 pmol), N-ethylmaleimide (1 or 2 nmol), forskolin (30 or 60 nmol) or phorbol 12-myristate 13-acetate (2 or 4 nmol), but not by cholera toxin (15 or 30 pmol). More specifically, pretreatments with bilateral microinjection into the nucleus tractus solitarius (NTS) of pertussis toxin (80 or 160 fmol), N-ethylmaleimide (80 pmol), forskolin (480 pmol) or phorbol 12-myristate 13-acetate (16 or 32 pmol) also blunted the NT-induced suppression of BRR, although cholera toxin (120 or 240 fmol), or 1,9-dideoxyforskolin (480 pmol) had no appreciable effect. These results suggest that a pertussis toxin-sensitive guanine nucleotide-binding regulatory protein(s), which is not likely to be Gs, possibly Gi or Gp, may be involved in the transmembrane signaling process that underlies the suppression of BRR response by NT at the NTS.


Asunto(s)
Proteínas de Unión al GTP/fisiología , Neurotensina/farmacología , Toxina del Pertussis , Presorreceptores/efectos de los fármacos , Reflejo/efectos de los fármacos , Factores de Virulencia de Bordetella/farmacología , Animales , Toxina del Cólera/farmacología , Colforsina/administración & dosificación , Colforsina/análogos & derivados , Colforsina/farmacología , Etilmaleimida/farmacología , Masculino , Neurotensina/administración & dosificación , Neurotensina/antagonistas & inhibidores , Ratas , Ratas Endogámicas , Acetato de Tetradecanoilforbol/farmacología
15.
Neurosci Lett ; 90(1-2): 172-6, 1988 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-3412638

RESUMEN

We evaluated the participation of endogenous brain angiotensin III (AIII) in central cardiovascular regulation, using the intracerebroventricular injection technique in Sprague-Dawley rats anesthetized with pentobarbital sodium (50 mg/kg, i.p.). AIII (100 pmol) promoted an elevation in systemic arterial pressure and a reduction in the baroreceptor reflex (BRR) response. Its specific antagonist, Ile7-AIII (100 nmol), and the aminopeptidase inhibitor, bestatin (200 nmol), on the other hand, augmented the response of the same reflex. The suppressive action of AIII (100 pmol) on the BRR was attenuated, and the enhancing effect of Ile7-AIII (100 nmol) was potentiated, however, when these two peptides were administered simultaneously with bestatin (200 nmol). All these events were significantly different from their controls during the first 10-15 min following injection, parallel to the time course of a discernible action of AIII on systemic arterial pressure. We discussed that the endogenous AIII in the central nervous system may participate in cardiovascular control by tonically inhibiting the BRR, in concert with other brain neuropeptides.


Asunto(s)
Angiotensina III/análogos & derivados , Angiotensina III/fisiología , Angiotensina II/análogos & derivados , Fenómenos Fisiológicos Cardiovasculares , Leucina/análogos & derivados , Presorreceptores/fisiología , Angiotensina III/farmacología , Animales , Presión Sanguínea/efectos de los fármacos , Sistema Cardiovascular/efectos de los fármacos , Inyecciones Intraventriculares , Leucina/farmacología , Masculino , Fenilefrina/farmacología , Presorreceptores/efectos de los fármacos , Ratas , Ratas Endogámicas , Factores de Tiempo
16.
J Chromatogr A ; 879(2): 197-210, 2000 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-10893036

RESUMEN

The influences of buffer pH, buffer concentration and buffer electrolyte on the migration behavior and separation of 12 cephalosporin antibiotics in capillary zone electrophoresis using three different types of buffer electrolyte, including phosphate, citrate, and 2-(N-morpholino)ethanesulfonate (MES), were investigated. The results indicate that, although buffer pH is a crucial parameter, buffer concentration also plays an important role in the separation of cephalosporins, particularly when cefuroxime and cefazolin, cephalexin and cefaclor, or cefotaxime and cephapirin are present as analytes at the same time. The electrophoretic mobility of cephalosporins and electroosmotic mobility measured in citrate and MES buffers are remarkably different from those measured in phosphate buffer. With citrate buffer, optimum buffer concentration is confined to a small range (35-40 mM), whereas buffer concentrations up to 300 mM can be used with MES buffer. Complete separations of 12 cephalosporins could be satisfactorily achieved with these three buffers under various optimum conditions. However, the separability of 12 cephalosporins with citrate or MES buffer is better than that with phosphate buffer. As a consequence of a greater electrophoretic mobility of cephalosporins than the electroosmotic mobility with citrate buffer at pH below about 5, some cephalosporins are not detectable. The cloudiness of the peak identification and of the magnitudes of the electrophoretic mobility of cefotaxime and cefuroxime reported previously are clarified. In addition, the pKa values of cephradine, cephalexin, cefaclor, and cephapirin attributed to the deprotonation of either an amino group or a pyridinium group are reported, and the migration behavior of these cephalosporins in the pH range studied is quantitatively described.


Asunto(s)
Cefalosporinas/aislamiento & purificación , Electroforesis Capilar/métodos , Ácidos Alcanesulfónicos/química , Tampones (Química) , Cefalosporinas/química , Electrólitos , Concentración de Iones de Hidrógeno , Morfolinas/química
17.
Nucl Med Commun ; 15(4): 294-7, 1994 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-8072744

RESUMEN

An attempt was made to use 99Tcm-ethyl cysteinate dimer (99Tcm-ECD) (Neurolite, Du Pont Merck, N. Billerica, MA) to label leukocytes. The radiochemical purity of 99Tcm-ECD, labelling efficiency of leukocytes, cell viability of labelled leukocytes and stability of 99Tcm-ECD-labelled leukocytes were calculated. Compared with the commercial cell-labelling agent, 99Tcm-hexamethylpropyleneamine oxime (99Tcm-HMPAO): (1) the radiochemical purity of 99Tcm-ECD was higher than that of 99Tcm-HMPAO and at immediately, 1, 2, 4, 6, 8 and 24 h after 99Tcm labelling; (2) the labelling efficiency of 99Tcm-ECD-labelled leukocytes was lower than that of 99Tcm-HMPAO; (3) the viability of the labelled white blood cells (WBC) was high for both agents; and (4) the stability of 99Tcm-ECD-labelled leukocytes was worse than that of 99Tcm-HMPAO at 1, 2, 4, 6, 8 and 24 h. It is concluded that although 99Tcm-ECD is more stable than 99Tcm-HMPAO, because of the lower labelling efficiency and power stability of 99Tcm-ECD-labelled leukocytes, 99Tcm-ECD is not a good choice as a leukocyte-labelling agent to replace commercial 99Tcm-HMPAO.


Asunto(s)
Cisteína/análogos & derivados , Leucocitos , Compuestos de Organotecnecio/química , Oximas/química , Supervivencia Celular , Estabilidad de Medicamentos , Humanos , Marcaje Isotópico/métodos , Leucocitos/citología , Leucocitos/metabolismo , Compuestos de Organotecnecio/aislamiento & purificación , Oximas/aislamiento & purificación , Radioquímica , Exametazima de Tecnecio Tc 99m
18.
Respir Care ; 24(4): 321-7, 1979 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10315053

RESUMEN

The dilution of acid glutaraldehyde solution and its effect on microbiological effectiveness were investigated using Sonacide and the Cidematic Decontamination System under normal use conditons at 18 hospitals over a 4-week period. The dilution of Sonacide was found to follow first-order kinetics and is described by the equation, ln C = ln Co-KT, where K is the apparent dilution-rate constant. The average dilution-rate constant under normal use conditions was 0.015/day. It takes an average of 47 days under normal hospital-use conditions to reduce its potency to half its original strength. The average glutaraldehyde concentration after 28 days' use was found to be approximately 66% of the initial concentration. The AOAC use-dilution test was employed to evaluate the microbiological effectiveness of the Sonacide samples collected weekly for four weeks. Results showed that all the Sonacide samples from 18 hospitals passed the AOAC use-dilution test for Pseudomonas aeruginosa (ATCC 15442). Based on this study, it is apparent that Sonacide can be used to disinfect various anesthesia and respiratory therapy equipment for up to 4 weeks in the Cidematic machine.


Asunto(s)
Aldehídos/normas , Anestesiología/instrumentación , Desinfección/métodos , Glutaral/normas , Hospitales , Terapia Respiratoria/instrumentación , Esterilización/métodos , Estudios de Evaluación como Asunto , Humanos , Estándares de Referencia , Estadística como Asunto , Estados Unidos
19.
Chemosphere ; 40(4): 383-7, 2000 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-10665403

RESUMEN

Behavior of Br in pyrolysis of the printed circuit board waste with valuable copper and oil recycling has been studied in the present work. Experimentally, pyrolysis of the printed circuit board waste generated approximately 40.6% of oils, 24.9% of noncondensible gases and 34.5% of solid residues that enriched in copper (90-95%). The cuts of the oils produced from pyrolysis of the printed circuit board waste into weighted boiling fraction were primarily light naphtha and heavy gas oil. Approximately 72.3% of total Br in the printed circuit board waste were found in product gas mainly as HBr and bromobenzene. However, by extended X-ray absorption fine structural (EXAFS) spectroscopy, Cu-O and Cu-(O)-Cu species with bond distance of 1.87 and 2.95 A, respectively, were observed in the solid residues. Essentially, no Cu-Br species was found.


Asunto(s)
Bromo , Residuos Industriales , Administración de Residuos/métodos , Cobre/análisis , Electrónica , Calor , Hidrólisis , Aceites/análisis
20.
J Environ Qual ; 30(4): 1392-401, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11476518

RESUMEN

Proper disposal of construction and demolition wastes (CDW) has received wide attention recently due to significantly large quantities of waste streams collected from razed or retrofitted buildings in many metropolitan regions. Burning the combustible fractions of CDW (CCDW) and possibly recovering part of the heat content for economic uses could be valuable for energy conservation. This paper explores the oxidation kinetics of CCDW associated with its ash characterization. Kinetic parameters for the oxidation of CCDW were numerically calculated using thermal gravimetric analysis (TGA) and the resultant rate equations were therefore developed for illustrating the oxidation processes of CCDW simultaneously. Based on three designated heating rates, each of the oxidation processes can be featured distinctively with five different stages according to the rate of weight change at the temperature between 300 K and 923 K. In addition, Fourier transform infrared (FTIR) spectroscopy was employed, associated with a lab-scale fixed-bed incinerator for monitoring the composition of flue gas. Carbon dioxide (CO2) was found as a major component in the flue gas. The fuel analysis also included an ash composition analysis via the use of X-ray powder diffraction (XRD), atomic absorption (AA) spectroscopy, inductively coupled plasma-atomic emission spectroscopy (ICP-AES), and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDX). The ash streams were identified as nonhazardous materials based on the toxicity characteristic leaching procedure (TCLP). Overall, the scientific findings gained in this study will be helpful for supporting a sound engineering design of real-world CCDW incineration systems.


Asunto(s)
Contaminantes Atmosféricos/análisis , Conservación de los Recursos Naturales , Materiales de Construcción , Eliminación de Residuos , Dióxido de Carbono/análisis , Ingeniería , Gases/química , Incineración , Cinética , Oxidación-Reducción , Espectrofotometría Atómica , Espectroscopía Infrarroja por Transformada de Fourier , Difracción de Rayos X
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