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1.
Nature ; 595(7866): 223-226, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34234332

RESUMO

Neutron-star mergers were recently confirmed as sites of rapid-neutron-capture (r-process) nucleosynthesis1-3. However, in Galactic chemical evolution models, neutron-star mergers alone cannot reproduce the observed element abundance patterns of extremely metal-poor stars, which indicates the existence of other sites of r-process nucleosynthesis4-6. These sites may be investigated by studying the element abundance patterns of chemically primitive stars in the halo of the Milky Way, because these objects retain the nucleosynthetic signatures of the earliest generation of stars7-13. Here we report the element abundance pattern of the extremely metal-poor star SMSS J200322.54-114203.3. We observe a large enhancement in r-process elements, with very low overall metallicity. The element abundance pattern is well matched by the yields of a single 25-solar-mass magnetorotational hypernova. Such a hypernova could produce not only the r-process elements, but also light elements during stellar evolution, and iron-peak elements during explosive nuclear burning. Hypernovae are often associated with long-duration γ-ray bursts in the nearby Universe8. This connection indicates that similar explosions of fast-spinning strongly magnetized stars occurred during the earliest epochs of star formation in our Galaxy.

2.
Ann Oncol ; 27(11): 2111-2117, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27742657

RESUMO

BACKGROUND: Inflammatory myofibroblastic tumors (IMTs) are rare sarcomas that can occur at any age. Surgical resection is the primary treatment for patients with localized disease; however, these tumors frequently recur. Less commonly, patients with IMTs develop or present with metastatic disease. There is no standard of care for these patients and traditional cytotoxic therapy is largely ineffective. Most IMTs are associated with oncogenic ALK, ROS1 or PDGFRß fusions and may benefit from targeted therapy. PATIENT AND METHODS: We sought to understand the genomic abnormalities of a patient who presented for management of metastatic IMT after progression of disease on crizotinib and a significant and durable partial response to the more potent ALK inhibitor ceritinib. RESULTS: The residual IMT was resected based on the recommendations of a multidisciplinary tumor sarcoma tumor board and analyzed by whole-genome mate pair sequencing. Analysis of the residual, resected tumor identified a chromoplectic TPM3-ALK rearrangement that involved many other known oncogenes and was confirmed by rtPCR. CONCLUSIONS: In our analysis of the treatment-resistant, residual IMT, we identified a complex pattern of genetic rearrangements consistent with chromoplexy. Although it is difficult to know for certain if these chromoplectic rearrangements preceded treatment, their presence suggests that chromoplexy has a role in the oncogenesis of IMTs. Furthermore, this patient's remarkable response suggests that ceritinib should be considered as an option after progression on crizotinib for patients with metastatic or unresectable IMT and ALK mutations.


Assuntos
Recidiva Local de Neoplasia/tratamento farmacológico , Receptores Proteína Tirosina Quinases/genética , Sarcoma/tratamento farmacológico , Tropomiosina/genética , Adulto , Quinase do Linfoma Anaplásico , Crizotinibe , Resistencia a Medicamentos Antineoplásicos , Humanos , Masculino , Miofibroblastos/efeitos dos fármacos , Miofibroblastos/patologia , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/patologia , Proteínas de Fusão Oncogênica/genética , Proteínas Tirosina Quinases/genética , Proteínas Proto-Oncogênicas/genética , Pirazóis/administração & dosagem , Piridinas/administração & dosagem , Pirimidinas/administração & dosagem , Receptor beta de Fator de Crescimento Derivado de Plaquetas/genética , Sarcoma/genética , Sarcoma/patologia , Padrão de Cuidado , Sulfonas/administração & dosagem
3.
J Neurol Sci ; 463: 123118, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-39024743

RESUMO

Data are limited on the impact of commencing antiplatelet therapy on von Willebrand Factor Antigen (VWF:Ag) or von Willebrand Factor propeptide (VWFpp) levels and ADAMTS13 activity, and their relationship with platelet reactivity following TIA/ischaemic stroke. In this pilot, observational study, VWF:Ag and VWFpp levels and ADAMTS13 activity were quantified in 48 patients ≤4 weeks of TIA/ischaemic stroke (baseline), and 14 days (14d) and 90 days (90d) after commencing aspirin, clopidogrel or aspirin+dipyridamole. Platelet reactivity was assessed at moderately-high shear stress (PFA-100® Collagen-Epinephrine / Collagen-ADP / INNOVANCE PFA P2Y assays), and low shear stress (VerifyNow® Aspirin / P2Y12, and Multiplate® Aspirin / ADP assays). VWF:Ag levels decreased and VWFpp/VWF:Ag ratio increased between baseline and 14d and 90d in the overall population (P ≤ 0.03). In the clopidogrel subgroup, VWF:Ag levels decreased and VWFpp/VWF:Ag ratio increased between baseline and 14d and 90d (P ≤ 0.01), with an increase in ADAMTS13 activity between baseline vs. 90d (P ≤ 0.03). In the aspirin+dipyridamole subgroup, there was an inverse relationship between VWF:Ag and VWFpp levels with both PFA-100 C-ADP and INNOVANCE PFA P2Y closure times (CTs) at baseline (P ≤ 0.02), with PFA-100 C-ADP, INNOVANCE PFA P2Y and C-EPI CTs at 14d (P ≤ 0.05), and between VWF:Ag levels and PFA-100 INNOVANCE PFA P2Y CTs at 90d (P = 0.03). There was a positive relationship between ADAMTS13 activity and PFA-100 C-ADP CTs at baseline (R2 = 0.254; P = 0.04). Commencing/altering antiplatelet therapy, mainly attributed to commencing clopidogrel in this study, was associated with decreasing endothelial activation following TIA/ischaemic stroke. These data enhance our understanding of the impact of VWF:Ag and VWFpp especially on ex-vivo platelet reactivity status at high shear stress after TIA/ischaemic stroke.


Assuntos
Proteína ADAMTS13 , Ataque Isquêmico Transitório , AVC Isquêmico , Inibidores da Agregação Plaquetária , Fator de von Willebrand , Humanos , Fator de von Willebrand/metabolismo , Proteína ADAMTS13/sangue , Masculino , Feminino , Inibidores da Agregação Plaquetária/uso terapêutico , Idoso , Pessoa de Meia-Idade , Ataque Isquêmico Transitório/sangue , Ataque Isquêmico Transitório/tratamento farmacológico , AVC Isquêmico/sangue , AVC Isquêmico/tratamento farmacológico , Projetos Piloto , Clopidogrel/uso terapêutico , Precursores de Proteínas
4.
J Neurol Sci ; 441: 120334, 2022 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-36030623

RESUMO

BACKGROUND: Data are limited on the ability of dipyridamole to additionally inhibit platelet function/reactivity in ischaemic cerebrovascular disease (CVD) patients on aspirin. AIMS: To assess inhibition of platelet function/reactivity and platelet activation with dipyridamole in CVD. METHODS: This prospective, observational study assessed TIA/ischaemic stroke patients before (baseline; N = 60), at 14 ±7 days (14d, N = 39) and ≥ 90 days (90d, N = 31) after adding dipyridamole to aspirin. Platelet function/reactivity at high shear stress (PFA-100® C-ADP) and low shear stress (VerifyNow® P2Y12 and Multiplate® ADP assays), and platelet activation status (% expression of CD62P, CD63 and leucocyte-platelet complexes on whole blood flow cytometry) were quantified. 'Dipyridamole-high on-treatment platelet reactivity (HTPR)' was defined as failure to inhibit ADP-induced platelet aggregation +/- adhesion compared with the patient's baseline on aspirin monotherapy by more than twice the coefficient-of-variation of the assay after adding dipyridamole to aspirin. RESULTS: Dipyridamole-HTPR was identified in 71.4-75% of patients on PFA-100 C-ADP, 83.9-86.8% of patients on VerifyNow P2Y12, and 81.5-83.3% of patients on Multiplate ADP assays. There were no changes in CD62P/CD63 expression (P ≥ 0.18), or consistent changes in leucocyte-platelet complexes in CVD patients overall at 14d or 90d vs. baseline after commencing dipyridamole. Monocyte-platelet complexes increased in the patient subgroup with dipyridamole-HTPR at 14d and 90d on PFA-100, and at 14d on VerifyNow (P ≤ 0.04), but not in those without dipyridamole-HTPR. DISCUSSION: Additional antiplatelet effects of dipyridamole are detectable under high and low shear stress conditions with user-friendly platelet function/reactivity tests ex vivo. Increasing circulating monocyte-platelet complexes over time are associated with dipyridamole-HTPR.


Assuntos
Isquemia Encefálica , Ataque Isquêmico Transitório , AVC Isquêmico , Acidente Vascular Cerebral , Difosfato de Adenosina/metabolismo , Difosfato de Adenosina/farmacologia , Aspirina/farmacologia , Aspirina/uso terapêutico , Plaquetas , Isquemia Encefálica/metabolismo , Dipiridamol/metabolismo , Dipiridamol/farmacologia , Dipiridamol/uso terapêutico , Humanos , Ataque Isquêmico Transitório/tratamento farmacológico , Ativação Plaquetária , Inibidores da Agregação Plaquetária/farmacologia , Inibidores da Agregação Plaquetária/uso terapêutico , Estudos Prospectivos
5.
J Neurol ; 267(1): 168-184, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31606758

RESUMO

BACKGROUND: Assessment of 'high on-treatment platelet reactivity (HTPR)' could enhance understanding of the pathophysiology of first or recurrent vascular events in carotid stenosis patients on antiplatelet therapy. METHODS: This prospective, multi-centre study assessed antiplatelet-HTPR status and its relationship with micro-emboli signals (MES) in asymptomatic vs. symptomatic ≥ 50-99% carotid stenosis. Platelet function/reactivity was assessed under 'moderately high shear stress' with the PFA-100® and 'low shear stress' with VerifyNow® and Multiplate® analysers. Bilateral 1-h transcranial Doppler ultrasound of the middle cerebral arteries classified patients as MES + ve or MES - ve. RESULTS: Data from 34 asymptomatic patients were compared with 43 symptomatic patients in the 'early phase' (≤ 4 weeks) and 37 patients in the 'late phase' (≥ 3 months) after TIA/ischaemic stroke. Median daily aspirin doses were higher in early symptomatic (225 mg; P < 0.001), but not late symptomatic (75 mg; P = 0.62) vs. asymptomatic patients (75 mg). There was a lower prevalence of aspirin-HTPR in early (28.6%; P = 0.028), but not late symptomatic (38.9%; P = 0.22) compared with asymptomatic patients (56.7%) on the PFA-100®, but not on the VerifyNow® or Multiplate® (P ≤ 0.53). Early symptomatic patients had a higher prevalence of aspirin-HTPR on the PFA-100® (28.6%) vs. VerifyNow® (9.5%; P = 0.049), but not Multiplate® assays (11.9%, P = 0.10). There was no difference in aspirin-HTPR prevalence between any symptomatic vs. asymptomatic MES + ve or MES - ve subgroup. DISCUSSION: Recently symptomatic moderate-severe carotid stenosis patients had a lower prevalence of aspirin-HTPR than their asymptomatic counterparts on the PFA-100®, likely related to higher aspirin doses. The prevalence of antiplatelet-HTPR was positively influenced by higher shear stress levels, but not MES status.


Assuntos
Aspirina/farmacologia , Plaquetas , Estenose das Carótidas/tratamento farmacológico , Embolia Intracraniana/tratamento farmacológico , Inibidores da Agregação Plaquetária/farmacologia , Idoso , Aspirina/administração & dosagem , Plaquetas/efeitos dos fármacos , Plaquetas/fisiologia , Isquemia Encefálica/tratamento farmacológico , Estenose das Carótidas/diagnóstico por imagem , Feminino , Humanos , Embolia Intracraniana/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Artéria Cerebral Média/diagnóstico por imagem , Inibidores da Agregação Plaquetária/administração & dosagem , Estudos Prospectivos , Acidente Vascular Cerebral/tratamento farmacológico , Ultrassonografia Doppler Transcraniana
6.
Gut ; 57(6): 734-9, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18025067

RESUMO

OBJECTIVE: A number of studies have shown an inverse association between infection with Helicobacter pylori and oesophageal adenocarcinoma (OAC). The mechanism of the apparent protection against OAC by H pylori infection and, in particular, the role of gastric atrophy is disputed. The relationship between all stages of the oesophageal inflammation, metaplasia, adenocarcinoma sequence and H pylori infection and gastric atrophy was explored. METHODS: A case-control study involving 260 population controls, 227 OAC, 224 Barrett's oesophagus (BO) and 230 reflux oesophagitis (RO) patients recruited within Ireland was carried out. H pylori and CagA (cytotoxin-associated gene product A) infection was diagnosed serologically by western blot, and pepsinogen I and II levels were measured by enzyme immunoassay. Gastric atrophy was defined as a pepsinogen I/II ratio of <3. RESULTS: H pylori seropositivity was inversely associated with OAC, BO and RO; adjusted ORs (95% CIs), 0.49 (0.31 to 0.76), 0.35 (0.22 to 0.56) and 0.42 (0.27 to 0.65), respectively. Gastric atrophy was uncommon (5.3% of all subjects), but was inversely associated with non-junctional OAC, BO and RO; adjusted ORs (95% CIs), 0.34 (0.10 to 1.24), 0.23 (0.05 to 0.96) and 0.27 (0.08 to 0.88), respectively. Inverse associations between H pylori and the disease states remained in gastric atrophy-negative patients. CONCLUSION: H pylori infection and gastric atrophy are associated with a reduced risk of OAC, BO and RO. While use of the pepsinogen I/II ratio as a marker for gastric atrophy has limitations, these data suggest that although gastric atrophy is involved it may not fully explain the inverse associations observed with H pylori infection.


Assuntos
Adenocarcinoma/complicações , Neoplasias Esofágicas/complicações , Gastrite Atrófica/complicações , Infecções por Helicobacter/complicações , Helicobacter pylori/isolamento & purificação , Idoso , Anticorpos Antibacterianos/sangue , Antígenos de Bactérias/sangue , Proteínas de Bactérias/sangue , Esôfago de Barrett/complicações , Estudos de Casos e Controles , Esofagite Péptica/complicações , Feminino , Helicobacter pylori/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Lesões Pré-Cancerosas/complicações , Medição de Risco
7.
Psychooncology ; 17(12): 1196-201, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18470954

RESUMO

OBJECTIVE: To investigate strain and mental health among family caregivers of oesophageal cancer patients and possible factors associated with caregiver mental health and strain. METHODS: Patients with oesophageal adenocarcinoma in Ireland were recruited into the FINBAR study (the main aim of which was to investigate factors influencing the Barrett's adenocarcinoma relationship). Carers completed the 13-item Caregiver Strain Index and the General Health Questionnaire-30 (GHQ) in the context of a brief interview with trained research staff that was undertaken separately from the interview with each cancer patient. RESULTS: Two hundred and twenty-seven patients participated in the FINBAR study. A total of 39 patients did not have a family carer or the carer could not be identified. Fifty percent (94/188) of carers completed the questionnaires. Mean (SD) scores for strain (6.65, SD=3.63) and mental health status (10.21, SD=7.30) were high and 71% of carers scored >5 on the GHQ indicating psychological distress. There was a statistically significant positive relationship between level of strain experienced by caregivers and the severity of their mental health status and whether or not carers scored >5 on the GHQ. Relatives were 1.70 (95% CI 1.34-2.15) times more likely to be defined as high scorers with each unit increase in the CSI score. CONCLUSIONS: A significant proportion of caregivers experienced high levels of strain and psychological distress. There is a need to provide appropriate support and services targeted specifically at reducing the considerable strain of caring for patients with oesophageal cancer, particularly for carers of patients from lower socioeconomic groups.


Assuntos
Cuidadores/psicologia , Cuidadores/estatística & dados numéricos , Neoplasias Esofágicas , Estresse Psicológico/epidemiologia , Estresse Psicológico/psicologia , Idoso , Demografia , Feminino , Nível de Saúde , Humanos , Irlanda , Masculino , Apoio Social , Fatores Socioeconômicos , Estresse Psicológico/diagnóstico , Inquéritos e Questionários
8.
J Neurol ; 265(5): 1037-1049, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29476243

RESUMO

BACKGROUND: The pathophysiological mechanisms responsible for the disparity in stroke risk between asymptomatic and symptomatic carotid stenosis patients are not fully understood. The functionally important reticulated platelet fraction and reticulocytes could play a role. OBJECTIVES: We performed a prospective, multi-centre, observational analytical study comparing full blood count parameters and platelet production/turnover/activation markers in patients with asymptomatic versus recently symptomatic moderate (≥ 50-69%) or severe (≥ 70-99%) carotid stenosis. PATIENTS/METHODS: Data from 34 asymptomatic patients were compared with 43 symptomatic patients in the 'early phase' (≤ 4 weeks) and 37 of these patients in the 'late phase' (≥ 3 months) after TIA/ischaemic stroke. Reticulated platelets were quantified by whole blood flow cytometry and reticulated platelets and red cell reticulocytes by 'automated assays' (Sysmex XE-2100™). Bilateral simultaneous transcranial Doppler ultrasound monitoring classified patients as micro-embolic signal (MES)+ve or MES-ve. RESULTS: Mean platelet count was higher in early (216 × 109/L; P = 0.04) and late symptomatic (219 × 109/L; P = 0.044) than asymptomatic patients (194 × 109/L). Mean platelet volume was higher in early symptomatic than asymptomatic patients (10.8 vs. 10.45 fl; P = 0.045). Automated assays revealed higher % reticulated platelet fractions in early (5.78%; P < 0.001) and late symptomatic (5.11%; P = 0.01) than asymptomatic patients (3.48%). Red cell reticulocyte counts were lower in early (0.92%; P = 0.035) and late symptomatic (0.93%; P = 0.036) than asymptomatic patients (1.07%). The automated % reticulated platelet fraction was also higher in early symptomatic than asymptomatic MES-ve patients (5.7 vs. 3.55%; P = 0.001). DISCUSSION: The combination of increased platelet counts and a shift towards production of an increased population of larger, young, reticulated platelets could contribute to a higher risk of first or recurrent cerebrovascular events in recently symptomatic versus asymptomatic carotid stenosis, including those who are MES-ve.


Assuntos
Plaquetas , Estenose das Carótidas/sangue , Idoso , Automação Laboratorial , Estenose das Carótidas/tratamento farmacológico , Feminino , Citometria de Fluxo , Seguimentos , Humanos , Estudos Longitudinais , Masculino , Inibidores da Agregação Plaquetária/uso terapêutico , Contagem de Plaquetas , Estudos Prospectivos , Índice de Gravidade de Doença
9.
Mol Biol Cell ; 15(6): 2853-62, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15075369

RESUMO

Epithelial cells in vivo form tight cell-cell associations that spatially separate distinct apical and basolateral domains. These domains provide discrete cellular processes essential for proper tissue and organ development. Using confocal imaging and selective plasma membrane domain activation, the type I and type II transforming growth factor-beta (TGFbeta) receptors were found to be localized specifically at the basolateral surfaces of polarized Madin-Darby canine kidney (MDCK) cells. Receptors concentrated predominantly at the lateral sites of cell-cell contact, adjacent to the gap junctional complex. Cytoplasmic domain truncations for each receptor resulted in the loss of specific lateral domain targeting and dispersion to both the apical and basal domains. Whereas receptors concentrate basolaterally in regions of direct cell-cell contact in nonpolarized MDCK cell monolayers, receptor staining was absent from areas of noncell contact. In contrast to the defined basolateral polarity observed for the TGFbeta receptor complex, TGFbeta ligand secretion was found to be from the apical surfaces. Confocal imaging of MDCK cells with an antibody to TGFbeta1 confirmed a predominant apical localization, with a stark absence at the basal membrane. These findings indicate that cell adhesion regulates the localization of TGFbeta receptors in polarized epithelial cultures and that the response to TGFbeta is dependent upon the spatial distribution and secretion of TGFbeta receptors and ligand, respectively.


Assuntos
Polaridade Celular , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Junções Aderentes/metabolismo , Animais , Adesão Celular , Linhagem Celular , Membrana Celular/metabolismo , Polaridade Celular/efeitos dos fármacos , Cães , Humanos , Ligantes , Transporte Proteico , Receptores de Fatores de Crescimento Transformadores beta/química , Receptores de Fatores de Crescimento Transformadores beta/genética , Deleção de Sequência/genética , Transfecção , Fator de Crescimento Transformador beta/farmacologia
10.
J Gen Physiol ; 90(5): 625-50, 1987 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-3500998

RESUMO

Both regional differences in mucosal sensitivity and a gas chromatography-like process along the mucosal sheet have been separately proposed in two sets of earlier studies to produce different odorant-dependent activity patterns across the olfactory mucosa. This investigation evaluated, in one study, whether and to what degree these two mechanisms contribute to the generation of these activity patterns. Summated multiunit discharges were simultaneously recorded from lateral (LN) and medial (MN) sites on the bullfrog's olfactory nerve to sample the mucosal activity occurring near the internal and external nares, respectively. Precisely controlled sniffs of four odorants (benzaldehyde, butanol, geraniol, and octane) were drawn through the frog's olfactory sac in both the forward (H1) and reverse (H2) hale directions. By combining the four resulting measurements, LNH1, LNH2, MNH1, and MNH2, in different mathematical expressions, indexes reflecting the relative effects of the chromatographic process, regional sensitivity, and hale direction could be calculated. Most importantly, the chromatographic process and the regional sensitivity differences both contributed significantly to the mucosal activity patterns. However, their relative roles varied markedly among the four odorants, ranging from complete dominance by either one to substantial contributions from each. In general, the more strongly an odorant was sorbed by the mucosa, the greater was the relative effect of the chromatographic process; the weaker the sorption, the greater the relative effect of regional sensitivity. Similarly, the greater an odorant's sorption, the greater was the effect of hale direction. Other stimulus variables (sniff volume, sniff duration, and the number of molecules within the sniff) had marked effects upon the overall size of the response. For strongly sorbed odorants, the effect of increasing volume was positive; for a weakly sorbed odorant, it was negative. The reverse may be true for duration. In contrast, the effect of increasing the number of molecules was uniformly positive for all four odorants. However, there was little evidence that these other stimulus variables had a major influence upon the effects of the chromatographic process and regional sensitivity differences in their generation of mucosal activity patterns.


Assuntos
Odorantes , Mucosa Olfatória/fisiologia , Nervo Olfatório/fisiologia , Monoterpenos Acíclicos , Animais , Benzaldeídos , Butanóis , Octanos , Rana catesbeiana , Terpenos
11.
Ir J Med Sci ; 184(3): 557-8, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25618171

RESUMO

In recent years, more attention has been given to Charles Lucas's medical career, in its own way just as interesting and important as his better-known political campaigns. Lucas's first concentrated period of medical activity was in the 1730s, when he had qualified as an apothecary, the second in the 1750s, following his flight from Ireland and achievement of qualifications in medicine. Having been prominently involved in the campaign which led to the 1735 drugs regulation act, in 1741 Lucas published a pamphlet, Pharmacomastix, which detailed abuses common in the apothecary's trade and pressed for more radical controls. His most substantial medical work, An Essay on Waters, was published in London in 1756, being devoted to analysis of European spas and the promotion of hydrotherapy. Lucas was able to return to Ireland in 1761 and was elected MP for Dublin city. While politics occupied most of his time until his death in 1771, Lucas maintained his interest in matters medical, securing the passage of another drugs regulation act in 1761, which remarkably is still on the Irish statute book.


Assuntos
Balneologia/história , Hidroterapia/história , Escrita Médica/história , Educação Médica/história , História da Farmácia , História do Século XVIII , Higiene/história , Irlanda , Legislação de Medicamentos/história , Política
12.
Stroke ; 31(12): 3041-6, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11108769

RESUMO

BACKGROUND AND PURPOSE: The impact of postmenopausal estrogen replacement therapy on stroke prevention and stroke severity remains controversial. Previously we have shown that cerebral tissue infarction volume sustained after middle cerebral artery (MCA) occlusion is smaller in female than in male animals. This protection is lost after ovariectomy but is restored by 17ss-estradiol replacement. However, the therapeutic range for estradiol is suboptimal, since only doses resulting in a narrow range of plasma levels are protective in brain. The present study tested the hypothesis that a benzothiophene analogue and selective estrogen receptor modulator, LY353381.HCl (LY), reduces tissue infarction after MCA occlusion in estrogen-deficient, ovariectomized female rats. METHODS: Ovariectomized female Wistar rats received LY 10 mg/kg (n=16) or an equivalent volume of vehicle (n=14) by gavage for 5 to 8 days. Subsequently, each animal was anesthetized with halothane (1.2%) and treated with 2 hours of MCA occlusion by the intraluminal filament technique and 22 hours of recovery. Infarction volumes in the cerebral cortex and caudoputamen were determined by 2, 3,5-triphenyltetrazolium chloride staining and digital image analysis. End-ischemic regional cerebral blood flow (CBF) was measured in separate animal cohorts by quantitative [(14)C]iodoantipyrine autoradiography. RESULTS: Caudoputamen infarction was reduced by LY treatment (49+/-6% versus 64+/-4% of ipsilateral caudoputamen in LY and vehicle groups, respectively; P:<0.05). Cerebral cortical infarction was not different in the LY compared with vehicle group (7+/-3% versus 13+/-4% of ipsilateral cerebral cortex, respectively). Intra-ischemic blood pressure, arterial blood gases, and temporalis muscle temperature were controlled and equivalent between treatment groups. Averaged laser-Doppler flow during MCA occlusion was 36+/-3% of baseline in the LY group versus 29%+/-2% in the vehicle group. However, end-ischemic CBF or blood flow distribution within the MCA territory was not altered by LY treatment. Cortical or caudoputamen tissue volumes with end-ischemic CBF <20 mL/100 g per minute were similar in both groups. CONCLUSIONS: We conclude that LY confers neuroprotection from focal cerebral ischemia in caudoputamen in ovariectomized female rats. The mechanism of protection is not linked to preservation of ischemic cerebral blood flow, as determined by end-occlusion quantitative autoradiography.


Assuntos
Antipirina/análogos & derivados , Infarto Cerebral/prevenção & controle , Antagonistas de Estrogênios/uso terapêutico , Piperidinas/uso terapêutico , Tiofenos/uso terapêutico , Animais , Autorradiografia , Isquemia Encefálica/prevenção & controle , Radioisótopos de Carbono , Infarto Cerebral/diagnóstico , Circulação Cerebrovascular/efeitos dos fármacos , Circulação Cerebrovascular/fisiologia , Modelos Animais de Doenças , Antagonistas de Estrogênios/farmacologia , Terapia de Reposição de Estrogênios , Feminino , Humanos , Ovariectomia , Piperidinas/farmacologia , Ratos , Ratos Wistar , Receptores de Estrogênio/efeitos dos fármacos , Tiofenos/farmacologia
13.
Pediatrics ; 92(5): 666-9, 1993 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-8414852

RESUMO

OBJECTIVE: To determine the incidence of cardiotoxicity in infants and children who receive continuous nebulized albuterol (CNA) for bronchospasm. DESIGN: Prospective, case series. SETTING: A university pediatric intensive care and pediatric subacute units. PATIENTS: Nineteen infants and children who received CNA for at least 24 hours. INTERVENTIONS: None. MEASUREMENTS: Creatinine phosphokinase (CK) was measured at the time of admission and then at 12, 24, 48, and 72 hours while the patient received CNA. Isoenzyme CK-MB fractions were measured if CK concentration was > or = 250 IU/L. One electrocardiogram was obtained for each patient during CNA treatment. All patients had continuous cardiac monitoring during continuous nebulization therapy. MAIN RESULTS: Creatinine phosphokinase levels remained within normal limits for 16 patients during CNA treatment. Three patients had elevated CK and in two CK-MB fractions were elevated at one measurement. None of the electrocardiograms showed evidence of ischemia and no arrhythmias were noted during CNA therapy, even in the patients with elevated CK-MB fractions. CONCLUSIONS: Continuous albuterol therapy appears to be safe in our patient population as there was no significant evidence of cardiotoxicity. The significance of the transient elevation of CK-MB without other evidence of cardiotoxicity remains to be determined.


Assuntos
Albuterol/efeitos adversos , Espasmo Brônquico/tratamento farmacológico , Cardiopatias/induzido quimicamente , Doença Aguda , Albuterol/administração & dosagem , Asma/complicações , Asma/tratamento farmacológico , Espasmo Brônquico/etiologia , Bronquiolite/complicações , Bronquiolite/tratamento farmacológico , Displasia Broncopulmonar/complicações , Displasia Broncopulmonar/tratamento farmacológico , Pré-Escolar , Creatina Quinase/sangue , Eletrocardiografia , Feminino , Cardiopatias/diagnóstico , Humanos , Lactente , Recém-Nascido , Isoenzimas , Masculino , Nebulizadores e Vaporizadores , Estudos Prospectivos
14.
Brain Res ; 727(1-2): 145-52, 1996 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-8842392

RESUMO

The present study has shown that hypoxia leads to expression of heat-shock protein in the brain of newborn piglets and this process is almost completely abolished by depletion of catecholamines prior to the hypoxic episode. The piglets were anesthetized and mechanically ventilated. One hour of hypoxia was generated by decreasing the oxygen fraction in the inspired gas (FiO2) from 22% to 6%-10%. FiO2 was then returned to the control value for a period of 2 h. Following the 2 h of reoxygenation, regional expression of the 72-kDa heat-shock protein (hsp72) mRNA was determined using in situ hybridization and autoradiography. The hypoxic insult (cortical pO2 = 3-10 mmHg) induced expression of hsp72 mRNA in regions of both white and gray matter, with strong expression occurring in the cerebral cortex of individual animals. Depleting the brain of catecholamines prior to hypoxia, by treating the animals with alpha-methyl-p-tyrosine (AMT), resulted in a major change in the hsp72 mRNA expression. In the catecholamine depleted group of animals, the intensity of hsp72 mRNA expression was greatly decreased or almost completely abolished relative to the nondepleted hypoxic group. These results suggest that the catecholamines play a significant role in the expression of the hsp72 gene in response to hypoxic insult in neonatal brain.


Assuntos
Encéfalo/metabolismo , Proteínas de Choque Térmico/biossíntese , Hipóxia Encefálica/metabolismo , Metiltirosinas/farmacologia , Transcrição Gênica , Tirosina 3-Mono-Oxigenase/antagonistas & inibidores , Animais , Animais Recém-Nascidos , Córtex Cerebral/metabolismo , Inibidores Enzimáticos/farmacologia , Proteínas de Choque Térmico HSP72 , Hibridização In Situ , Oxigênio/análise , RNA Mensageiro/análise , RNA Mensageiro/biossíntese , Valores de Referência , Suínos , Fatores de Tempo , Transcrição Gênica/efeitos dos fármacos , alfa-Metiltirosina
15.
Adv Exp Med Biol ; 471: 155-63, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10659143

RESUMO

The present study examined the effect of hypoxia on expression of 72-kDa heat shock protein (hsp72) mRNA in the newborn brain. The studies were carried out in anesthetized and mechanically ventilated newborn piglets, age 3-5 days. Hypoxic insult was induced by decreasing the fraction of inspired oxygen (FiO2) from 21% to 6% or 10% for 1 h. Oxygen pressure in the microvasculature of the cortex (cortical pO2) was measured by oxygen dependent quenching of the phosphorescence of phosphor dissolved in blood. Following the two hours of normoxic recovery, regional expression of the 72-kDa heat shock protein (hsp72) mRNA was determined using in situ hybridization and autoradiography. Two grades of hypoxia were studied. Mild hypoxia (cortical pO2 = 10-30 mm Hg) induced the expression of hsp72 mRNA predominantly in the subcortical white matter. In individual animals of this group, the extent of expression varied from isolated regions to widespread involvement of the white matter. Severe hypoxia (cortical pO2 = 3-10 mm Hg) induced the expression of hsp72 mRNA in both white and gray matter regions, with strong expression occurring in the cerebral cortex of individual animals. The present results indicate that immature white matter is more sensitive than gray matter to the hypoxia induced expression of hsp72 mRNA. Further, increased expression of hsp72 mRNA may be an indicator of a pathologic degree of hypoxic stress, and the observed increase may indicate that in the newborn brain the immature white matter is particularly sensitive to injury by hypoxia-ischemia and reperfusion.


Assuntos
Encéfalo/metabolismo , Proteínas de Choque Térmico/genética , Hipóxia Encefálica/metabolismo , Animais , Animais Recém-Nascidos , Encéfalo/patologia , Expressão Gênica , Proteínas de Choque Térmico HSP72 , Hipóxia Encefálica/genética , Hipóxia Encefálica/fisiopatologia , Oxigênio , RNA Mensageiro/metabolismo , Suínos
16.
Monaldi Arch Chest Dis ; 50(6): 453-8, 1995 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8834956

RESUMO

Primary immunodeficiency (ID) has an incidence of 1 in 10,000 and may have significant morbidity and mortality if not diagnosed and treated early. Children with signs and symptoms suggestive of immunodeficiency are often seen first by their paediatrician or family medical practitioner. For these reasons, it is essential that primary care physicians both of children and adults should be able to recognize the signs and symptoms of immunodeficiency and be knowledgeable about the screening procedures useful in the diagnosis of these diseases. However, this process is often complicated by the diverse presentations of immunodeficiency and the lack of specificity and relative inaccessibility of screening tests. The purpose of this paper is to address the major problems in diagnosis of immunodeficiency, including: 1) Which patients to seriously consider for diagnosis? 2) How to begin the work-up for primary immunodeficiency? 3) Which procedures are useful in the diagnosis of the various forms of immunodeficiency? and 4) What is the relative importance of immunoglobulin (IgG) subclasses?


Assuntos
Síndromes de Imunodeficiência/diagnóstico , Criança , Pré-Escolar , Proteínas do Sistema Complemento/deficiência , Granulócitos/imunologia , Humanos , Deficiência de IgG/diagnóstico , Síndromes de Imunodeficiência/epidemiologia , Síndromes de Imunodeficiência/genética , Testes Imunológicos , Incidência , Lactente , Exame Físico , Atenção Primária à Saúde , Linfócitos T/imunologia
17.
Contemp Top Lab Anim Sci ; 40(2): 9-12, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11300680

RESUMO

We examined retrospectively the effects of brief halothane anesthesia during daily gavage administration of vehicle on gavage-related complications and body weight in ovariectomized female Wistar rats. The number of gavage-related deaths or animals requiring euthanasia due to gavage problems was dramatically reduced, but the occurrence of incomplete vehicle retention during gavage was increased appreciably in halothane-anesthetized animals. Halothane-anesthetized rats maintained daily body weight for a longer period than did awake animals. Our observations suggest that the use of brief inhalational anesthesia reduces gavage-associated death and euthanasia due to esophageal trauma and minimizes stress-related weight loss.


Assuntos
Anestesia/veterinária , Anestésicos Inalatórios/administração & dosagem , Halotano/administração & dosagem , Intubação Gastrointestinal/efeitos adversos , Intubação Gastrointestinal/veterinária , Animais , Peso Corporal/efeitos dos fármacos , Esôfago/lesões , Feminino , Longevidade/efeitos dos fármacos , Ovariectomia , Ratos , Ratos Wistar , Estudos Retrospectivos , Estresse Fisiológico , Redução de Peso
18.
Percept Mot Skills ; 84(3 Pt 1): 835-47, 1997 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9172191

RESUMO

Previous research has shown that both vertical and lateral eye movements occur during mental tasks, although the neuropsychological basis for such movements remains unclear. Vertical and lateral eye movements were recorded from 24 right-dominant subjects as they performed three different mental tasks: a mental arithmetic task, a visuospatial imagery task, and a proverb interpretation task. Significant upward biases in the direction of the initial eye movement were observed as subjects answered a series of arithmetic and visuospatial questions along with a nonsignificant upward bias following a series of proverbs that subjects had to interpret. By contrast, no consistent lateral eye movement biases were found during any task. The results are interpreted according to Previc's recent theory linking processing in the upper and lower visual fields to ventral versus dorsal posterior cortical activation, respectively.


Assuntos
Movimentos Oculares , Lateralidade Funcional , Orientação , Resolução de Problemas , Adolescente , Adulto , Atenção/fisiologia , Córtex Cerebral/fisiologia , Dominância Cerebral/fisiologia , Movimentos Oculares/fisiologia , Feminino , Humanos , Individualidade , Masculino , Pessoa de Meia-Idade , Orientação/fisiologia , Resolução de Problemas/fisiologia
19.
Oncogene ; 33(29): 3776-83, 2014 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-24037524

RESUMO

ASCL1 is an important regulatory transcription factor in pulmonary neuroendocrine (NE) cell development, but its value as a biomarker of NE differentiation in lung adenocarcinoma (AD) and as a potential prognostic biomarker remains unclear. We examined ASCL1 expression in lung cancer samples of varied histologic subtype, clinical outcome and smoking status and compared with expression of traditional NE markers. ASCL1 mRNA expression was found almost exclusively in smokers with AD, in contrast to non-smokers and other lung cancer subtypes. ASCL1 protein expression by immunohistochemical (IHC) analysis correlated best with synaptophysin compared with chromogranin and CD56/NCAM. Analysis of a compendium of 367 microarray-based gene expression profiles in stage I lung adenocarcinomas identified significantly higher expression levels of the RET oncogene in ASCL1-positive tumors (ASCL1(+)) compared with ASCL1(-) tumors (q-value <10(-9)). High levels of RET expression in ASCL1(+) but not in ASCL1(-) tumors was associated with significantly shorter overall survival (OS) in stage 1 (P=0.007) and in all AD (P=0.037). RET protein expression by IHC had an association with OS in the context of ASCL1 expression. In silico gene set analysis and in vitro experiments by ASCL1 shRNA in AD cells with high endogenous expression of ASCL1 and RET implicated ASCL1 as a potential upstream regulator of the RET oncogene. Also, silencing ASCL1 in AD cells markedly reduced cell growth and motility. These results suggest that ASCL1 and RET expression defines a clinically relevant subgroup of ∼10% of AD characterized by NE differentiation.


Assuntos
Adenocarcinoma/genética , Adenocarcinoma/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Expressão Gênica , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Células Neuroendócrinas/metabolismo , Proteínas Proto-Oncogênicas c-ret/genética , Adenocarcinoma/mortalidade , Adenocarcinoma/patologia , Adenocarcinoma de Pulmão , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Biomarcadores/metabolismo , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/metabolismo , Proliferação de Células , Análise por Conglomerados , Seguimentos , Perfilação da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Imuno-Histoquímica , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/patologia , Estadiamento de Neoplasias , Proteínas Proto-Oncogênicas c-ret/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fatores de Risco , Fumar
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