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51.
Sierra B Serrano N Larrañaga P Plasencia EJ Inza I Jiménez JJ Revuelta P Mora ML 《Artificial intelligence in medicine》2001,22(3):233-248
Combining the predictions of a set of classifiers has shown to be an effective way to create composite classifiers that are more accurate than any of the component classifiers. There are many methods for combining the predictions given by component classifiers. We introduce a new method that combine a number of component classifiers using a Bayesian network as a classifier system given the component classifiers predictions. Component classifiers are standard machine learning classification algorithms, and the Bayesian network structure is learned using a genetic algorithm that searches for the structure that maximises the classification accuracy given the predictions of the component classifiers. Experimental results have been obtained on a datafile of cases containing information about ICU patients at Canary Islands University Hospital. The accuracy obtained using the presented new approach statistically improve those obtained using standard machine learning methods. 相似文献
52.
Adrenergic therapy of bronchial asthma 总被引:2,自引:0,他引:2
53.
L-dopa stimulates the release of [3H]gamma-aminobutyric acid in the basal ganglia of 6-hydroxydopamine lesioned rats 总被引:1,自引:0,他引:1
J Aceves B Floran D Martinez-Fong A Sierra S Hernandez S Mariscal 《Neuroscience letters》1991,121(1-2):223-226
L-DOPA stimulated the K(+)-induced [3H]GABA (gamma-aminobutyric acid) release from slices of substantia nigra pars reticulata, entopeduncular nucleus, globus pallidus and caudate-putamen isolated from the ipsilateral side of 6-hydroxydopamine-lesioned rats, but the release from ipsilateral subthalamic slices was not affected. In substantia nigra, L-DOPA stimulation (EC50 = 1 microM) of [3H]GABA release was dose-dependently blocked (IC50 = 0.1 microM for the stimulation caused by 10 microM L-DOPA) by the D1 antagonist SCH 23390, but was not affected by (-)-sulpiride, a D2 antagonist. SCH 23390 also blocked the stimulation in the other nuclei. The DOPA decarboxylase inhibitor NSD-1015 (500 microM) did not prevent the stimulation induced by L-DOPA in all of the studied nuclei. The results suggest that L-DOPA is able to activate D1 receptors located on the terminals of striatal projections via the dopamine formed by a decarboxylation mediated by an NSD-1015-resistant enzyme. Activation of the presynaptic D1 receptors results in stimulation of GABA release. 相似文献
54.
Impaired signal transduction in mitogen activated rat splenic lymphocytes during aging 总被引:3,自引:0,他引:3
Mitogen activated protein kinases (MAPK) are activated by a wide variety of signals leading to cell proliferation and differentiation in different cell types. With aging, there is a marked decrease in proliferation of T-lymphocytes in response to a variety of mitogens. Several age-related changes in the activation of MAPK pathways in T-lymphocytes activated via the T-cell receptor (TCR) have been described in different species. This way, some TCR proximal defects in tyrosine kinase activity have been delineated. In this study, we have used rat splenic lymphocytes to measure the effect of aging on the activation of two MAP kinase families: ERK and JNK. In order to bypass the receptor-proximal age-dependent defects previously described, we used phorbol ester (PMA) and Ca2+ ionophore (A23187) as co-mitogens. Our results demonstrate that splenic lymphocytes from old rats have a disturbance in the activation of the ERK and JNK MAPK signal transduction pathways, that are located downstream of the receptor-proximal events. At least part of the age-related defect leading to decreased ERK activity appears to be located upstream of ERK itself, since activation of MEK is also impaired. On the other hand, the observed defects in MAPK activation do result in decreased activation of downstream events, such as c-Jun phosphorylation. Thus, we conclude that aging of splenic lymphocytes results in a functional decline in signal transduction, and at least some of these defects are located downstream of the receptor-proximal events previously described by others. The impaired activity of these two MAP kinase pathways is likely to play a role in the diminished lymphoproliferation observed in old individuals. 相似文献
55.
Is the outcome of in-vitro fertilization and embryo transfer treatment improved by spontaneous or surgical drainage of a hydrosalpinx? 总被引:4,自引:7,他引:4
Sowter MC; Akande VA; Williams JA; Hull MG 《Human reproduction (Oxford, England)》1997,12(10):2147-2150
A pilot study was designed to examine whether the outcome of embryo
transfer in women with a hydrosalpinx might be improved by surgical
drainage of the hydrosalpinx at the time of oocyte collection for in- vitro
fertilization treatment. A comparative, controlled but retrospective
analysis of the results was performed of all women with infective tubal
damage aged <40 years old, who had ovulatory cycles, a normal uterus and
a partner with normal spermatozoa. A standardized treatment regimen was
used. A maximum of three embryos were transferred. Hydrosalpinx was defined
by prior hysterosalpingography and/or laparoscopy with transcervical dye
injection. A total of 237 embryo transfer cycles in women with
hydrosalpinges (tubal distension not visible in 151, visible but not
drained in 30 and drained in 56) were compared with 705 embryo transfer
cycles in women with tubal disease but no hydrosalpinx. Results were
analysed in the first three cycles but also separately in the first cycle
to check for bias. Success rates were higher in the first cycle, but did
not significantly influence overall differences. Implantation rates were
significantly reduced overall in the hydrosalpinx group (8.0 versus 13.2%
for controls; P < 0.001), being 8.3% (P < 0.01) in the subgroup
without evident tubal distension and 7.5% (not significant) in the drained
hydrosalpinx group. This study shows that tubal damage with distal
occlusion is associated with a marked reduction in embryo implantation,
even in the absence of obvious fluid distension. Surgical drainage of
distended hydrosalpinges appears to offer no benefit.
相似文献
56.
Iván Alvarez Anna Sureda Maria D Caballero Alvaro Urbano-Ispizua Josep M Ribera Miguel Canales Javier García-Conde Guillermo Sanz Reyes Arranz Maria T Bernal Javier de la Serna José L Díez José M Moraleda Daniel Rubió-Félix Blanca Xicoy Carmen Martínez Marivi V Mateos Jorge Sierra 《Biology of blood and marrow transplantation》2006,12(2):172-183
We report the results of reduced-intensity conditioning allogeneic stem cell transplantation (allo-RIC) in patients with advanced Hodgkin lymphoma (HL). Forty patients with relapsed or refractory HL were homogeneously treated with an RIC protocol (fludarabine 150 mg/m(2) intravenously plus melphalan 140 mg/m(2) intravenously) and cyclosporin A and methotrexate as graft-versus-host disease (GVHD) prophylaxis. Twenty-one patients (53%) had received >2 lines of chemotherapy, 23 patients (58%) had received radiotherapy, and 29 patients (73%) had experienced treatment failure with a previous autologous stem cell transplantation. Twenty patients (50%) were allografted in resistant relapse, and 38 patients received hematopoietic cells from an HLA-identical sibling. Five patients (12%) died from early transplant-related mortality (before day +100 after allo-RIC). One-year transplant-related mortality was 25%. Acute GVHD developed in 18 patients (45%). Chronic GVHD developed in 17 (45%) of the 31 evaluable patients. The response rate 3 months after the allo-RIC was 67% (21 [52%] complete remissions and 6 [15%] partial remissions). Eleven patients received donor lymphocyte infusions (DLIs) for disease relapse. The response rate after DLI was 54% (3 complete remissions and 3 partial remissions). Overall survival (OS) and progression-free survival (PFS) were 48% +/- 10% and 32% +/- 10% at 2 years, respectively. Refractoriness to chemotherapy was the only adverse prognostic factor for both OS (63% +/- 12% versus 35% +/- 13%; P = .05) and PFS (55% +/- 16% versus 10% +/- 9%; P = .006). For patients with failure of a prior autologous hematopoietic stem cell transplantation, results were especially good for those who experienced late relapses (>/=12 months: 2-year OS and PFS were 75% +/- 16% and 70% +/- 18%, respectively). These data suggest that allo-RIC is feasible in heavily pretreated HL patients and has an acceptable early transplant-related mortality. Results are better in patients allografted in sensitive disease. Both responses observed after the development of GVHD and DLI may suggest a graft-versus-HL effect. Allo-RIC has to be considered an effective therapeutic approach for patients who have had treatment failure with a previous autologous hematopoietic stem cell transplantation. 相似文献
57.
Immune response induction and new effector mechanisms possibly involved in protection conferred by the Cuban anti-meningococcal BC vaccine 下载免费PDF全文
Pérez O Lastre M Lapinet J Bracho G Díaz M Zayas C Taboada C Sierra G 《Infection and immunity》2001,69(7):4502-4508
This report explores the participation of some afferent mechanisms in the immune response induced by the Cuban anti-meningococcal vaccine VA-MENGOC-BC. The induction of delayed-type hypersensitivity in nursing babies and lymphocyte proliferation after immunization is demonstrated. The presence of gamma interferon IFN-gamma and interleukin-2 (IL-2) mRNAs but absence of IL-4, IL-5, and IL-10 mRNAs were observed in peripheral blood mononuclear cells from immunized subjects after in vitro challenge with outer membrane vesicles. In addition, some effector functions were also explored. The presence of opsonic activity was demonstrated in sera from vaccinees. The role of neutrophils as essential effector cells was shown. In conclusion, we have shown that, at least in the Cuban adult population, VA-MENGOC-BC induces mechanisms with a T-helper 1 pattern in the afferent and effector branches of the immune response. 相似文献
58.
Bacino CA Stockton DW Sierra RA Heilstedt HA Lewandowski R Van den Veyver IB 《American journal of medical genetics》2000,94(2):102-112
We describe a new syndrome of distal limb anomalies and pigmentary skin defects in 10 females of a large, four-generation pedigree. The family was ascertained through a 4-month-old infant girl with multiple anomalies, including hypertelorism, iris colobomas, low-set ears, midface hypoplasia, punched-out pigmentary abnormalities over the face and scalp, generalized brachydactyly, and digital fibromatosis. No affected males were identified in this pedigree. Affected females had a lower than normal male-to-female ratio of liveborn offspring, and some of them also had a history of several miscarriages. These findings, together with a significant variability in the phenotype of the affected females, suggest that this condition is inherited in an X-linked dominant fashion, with prenatal male lethality, and that X-inactivation plays an important role in the phenotypic expression of the disease. The syndrome has been described twice in the literature, but only in sporadic cases; it was therefore not recognized as a mendelian entity. Because the most consistent findings are anomalies of the distal skeleton of the limbs and localized pigmentary abnormalities of the skin, we named the syndrome "terminal osseous dysplasia with pigmentary defects." This condition, though rare, can be added to the small group of male lethal X-linked dominant disorders in humans. 相似文献
59.
A natural dual infection of inclusion body hepatitis and pox was confirmed in pigeons by histopathological and electron-microscopical examination. Poxvirus particles were observed in epithelial cells and intranuclear adeno-like virus particles were found in the liver of two pigeons. However, no single cell was found with both viruses. 相似文献
60.
Canfield MC; Tamarappoo BK; Moses AM; Verkman AS; Holtzman EJ 《Human molecular genetics》1997,6(11):1865-1871
Congenital nephrogenic diabetes insipidus (NDI) is a rare disease caused
most often by mutations in the vasopressin V2 receptor (AVPR2). We studied
a family which included a female patient with NDI with symptoms dating from
infancy. The patient responded to large doses of desmopressin (dDAVP) which
decreased urine volume from 10 to 4 I/day. Neither the parents nor the
three sisters were polyuric. The patient was found to be a compound
heterozygote for two novel recessive point mutations in the aquaporin-2
(AQP2) gene: L22V in exon 1 and C181W in exon 3. Residue Cys181 in AQP2 is
the site for inhibition of water permeation by mercurial compounds and is
located near to the NPA motif conserved in all aquaporins. Osmotic water
permeability (Pf) in Xenopus oocytes injected with cRNA encoding C181W-AQP2
was not increased over water control, while expression of L22V cRNA
increased the Pf to approximately 60% of that for wild-type AQP2.
Co-injection of the mutant cRNAs with the wild-type cRNA did not affect the
function of the wild-type AQP2. Immunolocalization of AQP2-transfected CHO
cells showed that the C181W mutant had an endoplasmic reticulum-like
intracellular distribution, whereas L22V and wild-type AQP2 showed endosome
and plasma membrane staining. Water permeability assays showed a high Pf in
cells expressing wild-type and L22V AQP2. This study indicates that AQP2
mutations can confer partially responsive NDI.
相似文献