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1.
J Stroke Cerebrovasc Dis ; 33(4): 107635, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38342272

RESUMEN

BACKGROUND AND AIMS: Moyamoya is a chronic brain vasculopathy involving the distal intracranial internal carotid artery (ICA) or proximal middle cerebral artery (MCA). Moyamoya patients can be divided into those with primary moyamoya disease (MMD) and those with moyamoya secondary to other known causes such as intracranial atherosclerosis (moymoya syndrome [MMS]). Our aim was to compare the characteristics of MMD patients to those of MMS patients in a sample of Israeli patients seen over the course of 20 years at a tertiary referral center. METHODS: Included patients were diagnosed with either MMD or MMS based on typical imaging findings and the presence or absence of known concomitant vascular risk factors or associated disorders and vascular disease. Patients with MMS were compared to those with MMD. Demographics, symptoms, signs, and radiological data were compared between the groups. Treatment options and long-term rates of recurrent stroke and functional outcome were also studied. RESULTS: Overall, 64 patients were included (25 MMD, 39 MMS). Patients with MMD were significantly younger (median IQR 20 (7-32) vs. 40 (19-52); p=0.035). Patients with MMS more often had vascular risk factors but there were no significant differences in clinical presentations or long-term disability rates between the groups and a similar proportion of patients underwent surgical interventions to restore hemispheric perfusion in both groups (48% vs. 44% MMS vs. MMD; p=0.7). Almost one in four patient had a recurrent stroke after the initial diagnosis in both groups. Most recurrences occurred in the pre-surgery period in the MMS group and in the post-surgery period in the MMD group. CONCLUSIONS: There were no statistically significant differences in clinical or radiological presentations between the MMS and MMD patients. The course is not benign with recurrent stroke occurring in as many as 25%. More data is needed in order to identify those at high risk for stroke occurrence and recurrence.


Asunto(s)
Enfermedad de Moyamoya , Accidente Cerebrovascular , Humanos , Enfermedad de Moyamoya/complicaciones , Enfermedad de Moyamoya/diagnóstico por imagen , Enfermedad de Moyamoya/epidemiología , Israel/epidemiología , Estudios Retrospectivos , Accidente Cerebrovascular/epidemiología , Infarto Cerebral/complicaciones
2.
J Stroke Cerebrovasc Dis ; 32(9): 107288, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37542761

RESUMEN

BACKGROUND: Large vessel occlusions (LVO) stroke is associated with cancer. Whether this association differs among patients with LVO that undergo endovascular thrombectomy (EVT) according to cancer type remains unknown. PATIENTS AND METHODS: Data from consecutive patients that underwent EVT for LVO at three academic centers were pulled and analyzed retrospectively. Patients with LVO and solid tumors were compared to those with hematological tumors. Associations of cancer type with 90-day functional outcome and mortality were calculated in multivariable analyses. RESULTS: Of the 154 patients with cancer and LVO that underwent EVT (mean age 74±11, 43% men, median NIHSS 15), 137 had solid tumors (89%) and 17 (11%) had hematologic tumors. Patients with solid cancer did not significantly differ from those with hematological malignancy in demographics, risk factor profile, stroke severity and subtype, and procedural variables. Outcome parameters including rates of favorable target recanalization and favorable outcome or mortality at discharge and 90 days post stroke were similar. Safety parameters including rates of symptomatic intracranial hemorrhage also did not differ between the groups. On regression analyses, controlling for various prognostic variables cancer type was not associated with mortality or favorable outcomes. CONCLUSIONS: Our study suggests that the safety and efficacy of EVT in patients with malignancy does not depend on cancer type. Patients with malignancy should be considered for EVT regardless of cancer type.


Asunto(s)
Isquemia Encefálica , Procedimientos Endovasculares , Accidente Cerebrovascular Isquémico , Neoplasias , Accidente Cerebrovascular , Lesiones del Sistema Vascular , Masculino , Humanos , Persona de Mediana Edad , Anciano , Anciano de 80 o más Años , Femenino , Estudios Retrospectivos , Resultado del Tratamiento , Procedimientos Endovasculares/efectos adversos , Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular/etiología , Accidente Cerebrovascular/terapia , Trombectomía/efectos adversos , Accidente Cerebrovascular Isquémico/etiología , Lesiones del Sistema Vascular/etiología , Neoplasias/complicaciones , Neoplasias/diagnóstico , Neoplasias/terapia , Isquemia Encefálica/etiología
3.
Eur J Neurol ; 27(6): 1039-1047, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32149450

RESUMEN

BACKGROUND AND PURPOSE: We investigated the effectiveness of intravenous thrombolysis (IVT) in acute ischaemic stroke (AIS) patients with large vessel or distal occlusions and mild neurological deficits, defined as National Institutes of Health Stroke Scale scores < 6 points. METHODS: The primary efficacy outcome was 3-month functional independence (FI) [modified Rankin Scale (mRS) scores 0-2] that was compared between patients with and without IVT treatment. Other efficacy outcomes of interest included 3-month favorable functional outcome (mRS scores 0-1) and mRS score distribution at discharge and at 3 months. The safety outcomes comprised all-cause 3-month mortality, symptomatic intracranial hemorrhage (ICH), asymptomatic ICH and severe systemic bleeding. RESULTS: We evaluated 336 AIS patients with large vessel or distal occlusions and mild stroke severity (mean age 63 ± 15 years, 45% women). Patients treated with IVT (n = 162) had higher FI (85.6% vs. 74.8%, P = 0.027) with lower mRS scores at hospital discharge (P = 0.034) compared with the remaining patients. No differences were detected in any of the safety outcomes including symptomatic ICH, asymptomatic ICH, severe systemic bleeding and 3-month mortality. IVT was associated with higher likelihood of 3-month FI [odds ratio (OR), 2.19; 95% confidence intervals (CI), 1.09-4.42], 3-month favorable functional outcome (OR, 1.99; 95% CI, 1.10-3.57), functional improvement at discharge [common OR (per 1-point decrease in mRS score), 2.94; 95% CI, 1.67-5.26)] and at 3 months (common OR, 1.72; 95% CI, 1.06-2.86) on multivariable logistic regression models adjusting for potential confounders, including mechanical thrombectomy. CONCLUSIONS: Intravenous thrombolysis is independently associated with higher odds of improved discharge and 3-month functional outcomes in AIS patients with large vessel or distal occlusions and mild stroke severity. IVT appears not to increase the risk of systemic or symptomatic intracranial bleeding.


Asunto(s)
Isquemia Encefálica , Accidente Cerebrovascular , Administración Intravenosa , Anciano , Isquemia Encefálica/tratamiento farmacológico , Femenino , Fibrinolíticos/uso terapéutico , Humanos , Hemorragias Intracraneales , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Accidente Cerebrovascular/tratamiento farmacológico , Trombectomía , Terapia Trombolítica , Resultado del Tratamiento
4.
Neuroradiology ; 62(10): 1335-1340, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32556423

RESUMEN

BACKGROUND AND AIMS: Clot extraction is associated with favorable outcome in patients with large vessel occlusions (LVO) undergoing endovascular thrombectomy (EVT). However, whether revascularization becomes futile or harmful with an increasing number of passes remains unknown. METHODS: We performed a retrospective analysis of 271 consecutive patients with LVO who underwent stentriever-based EVT as the primary recanalization strategy. Primary outcomes including favorable recanalization, survival, and favorable functional outcomes were compared according to a dichotomized number of stentriever passes utilized with a cutoff of 4. RESULTS: In the entire cohort, 234 (86%) patients reached favorable recanalization and 46 (17%) patients had ≥ 5 passes (range 5-40). Patients that had ≤ 4 passes had significantly higher rates of favorable recanalization and favorable outcomes and a trend towards lower mortality rates compared with those that had ≥ 5 stentriever passes (92% vs. 61%; p < 0.001, 52% vs. 30%; p = 0.009 and 12% vs. 22%, p = 0.098). Among patients that received ≥ 5 stentriever passes, 30% reached favorable outcomes. Patients who achieved recanalization after ≥ 5 passes had higher rates of favorable outcome in comparison with those who did not (p = 0.009). Among patients that had ≥ 5 stentriever passes favorable recanalization (OR 97.3, 95%CI 2.8-3399.3) and admission NIHSS (OR 0.77, 95%CI 0.60-0.99) remained independent predictors of favorable outcome, whereas the number of passes did not. CONCLUSIONS: A substantial proportion of patients reach favorable outcomes even when ≥ 5 stentriever passes are performed. Treatment choices should be individualized based on personal preferences and expertise as well as on patient and clot-specific characteristics.


Asunto(s)
Remoción de Dispositivos , Accidente Cerebrovascular Isquémico/diagnóstico por imagen , Accidente Cerebrovascular Isquémico/cirugía , Stents , Trombectomía/métodos , Anciano , Femenino , Humanos , Masculino , Pronóstico , Estudios Retrospectivos , Factores de Riesgo
5.
J Stroke Cerebrovasc Dis ; 29(8): 104948, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32689630

RESUMEN

BACKGROUND: Atrial fibrillation (AF) often leads to large vessel occlusions (LVO) which may necessitate endovascular thrombectomy (EVT). Whether the adequacy of treatment with oral anticoagulants (OAC) prior to LVO modifies outcomes remains unknown. PATIENTS AND METHODS: Consecutive EVT-treated LVO patients were recruited and the data was analyzed retrospectively. We combined patients with known AF that were untreated with OAC or inadequately treated with those with new-onset AF to form a group of undertreated-AF patients and compared them to adequately treated AF patients. RESULTS: Of the 230 patients included, 109 (47%) had AF (86 known AF, 23 new-onset AF). AF patients were significantly older and more often reached favorable recanalization but less often had favorable outcomes compared to those without AF. Most patients with known AF (76%) were inadequately treated at stroke onset. Patients with undertreated-AF more often received tPA prior to EVT (26% vs. 4% p=0.009), more often had favorable collaterals (65% vs. 33% p<0.001) and more often reached favorable outcomes (28% vs. 9%, p=0.047) compared to adequately treated AF patients. On multivariate analyses adequately treated AF did not impact survival (Odds Ration [OR] 0.89 95% Confidence Interval [CI] 0.23-3.43), chances for favorable recanalization (OR 0.57 95%CI 0.15-2.13) or favorable outcome (OR 5.95 95%CI 0.62-57.39). CONCLUSIONS: Treatment adequacy does not affect the rates of favorable functional outcome or survival in AF patients with LVO.


Asunto(s)
Anticoagulantes/administración & dosificación , Fibrilación Atrial/tratamiento farmacológico , Procedimientos Endovasculares , Trombosis Intracraneal/terapia , Accidente Cerebrovascular/terapia , Trombectomía , Administración Oral , Anciano , Anciano de 80 o más Años , Anticoagulantes/efectos adversos , Fibrilación Atrial/complicaciones , Fibrilación Atrial/diagnóstico , Procedimientos Endovasculares/efectos adversos , Femenino , Humanos , Trombosis Intracraneal/diagnóstico , Trombosis Intracraneal/etiología , Masculino , Persona de Mediana Edad , Sistema de Registros , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular/etiología , Trombectomía/efectos adversos , Resultado del Tratamiento
6.
Public Health ; 172: 40-42, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31158567

RESUMEN

OBJECTIVES: Nationally representative studies suggest 1-2% of Indonesian women (2.3 million) smoke various tobacco products daily; however, in recent years, there has been concern that the tobacco industry has successfully increased female smoking. Our objective was to describe current cigarette smoking behaviors, past quit attempts, and intention to quit of female daily smokers in Surabaya, Indonesia. STUDY DESIGN: Survey. METHODS: Female daily smokers (n = 112) in Surabaya, Indonesia, the country's second largest city, were recruited to participate in a survey during 2018. Convenience sampling was utilized in two malls. Potential participants were intercepted in or near designated smoking areas and invited to the nearby data collection site. Survey items from Global Adult Tobacco Survey and the International Tobacco Control Policy Evaluation Project were utilized. RESULTS: Participants self-reported smoking 13.8 cigarettes per day (7.3 white machine-rolled cigarettes per day, 4.2 kreteks per day, and 2.4 roll-your-own cigarettes per day). Over 75% smoked their first cigarette within 30 min of waking. Over 53% had a heaviness of smoking index score suggesting moderate or high addiction. Approximately half (51%) did not attempt to quit smoking in the previous 12 months, and 55% planned to quit beyond 6 months or not at all. CONCLUSIONS: Our sample smoked five to six more cigarettes per day than female daily smokers in previous national surveys. Relative to previous studies, our data suggest an unexpected preference for white machine-rolled cigarettes and that there could be, at a minimum, pockets of increased smoking and addiction among female daily smokers in Indonesia.


Asunto(s)
Fumar Cigarrillos/psicología , Intención , Fumadores/psicología , Cese del Hábito de Fumar/psicología , Adolescente , Adulto , Fumar Cigarrillos/epidemiología , Femenino , Humanos , Indonesia/epidemiología , Fumadores/estadística & datos numéricos , Encuestas y Cuestionarios , Adulto Joven
7.
Health Educ Res ; 31(6): 738-748, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-27923863

RESUMEN

Smoke-free laws, which ban smoking in public venues, can be effective in protecting public health, but it has been difficult to achieve compliance with these laws in low- and middle-income countries. This study was conducted to understand the social norms around public smoking and learn how to improve compliance in Bogor, the first Indonesian city to pass a comprehensive smoke-free law. Eleven stratified focus groups were conducted (n = 89). Data were analyzed using the theory of normative social behavior, which posits that the influence of descriptive norms (perceptions about what other people do) on behavior is moderated by injunctive norms (perceptions about what one is expected to do), outcome expectations and group identity. The findings showed that participants perceived smoking in public to be common for men (descriptive norm). Public smoking is acceptable except in places with air conditioning and around children or pregnant women (injunctive norms). Men smoke without penalty of social or legal sanctions (outcome expectations) and may feel affiliation with other smokers (group identity). Together, these factors support public smoking and inhibit compliance with the smoke-free law. Theory-based communication and policy remedies are suggested that may bolster compliance with Bogor's smoke-free law given the current pro-smoking norms.


Asunto(s)
Política para Fumadores/legislación & jurisprudencia , Conducta Social , Teoría Social , Adolescente , Adulto , Actitud Frente a la Salud , Países en Desarrollo , Femenino , Grupos Focales , Humanos , Indonesia , Masculino , Fumar/psicología , Adulto Joven
8.
J Neurol Sci ; 444: 120515, 2023 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-36493703

RESUMEN

BACKGROUND: Thrombotic complications including stroke were previously described following Covid-19. We aim to describe the clinical and radiological characteristics of Covid-19 related with acutely symptomatic carotid stenosis (aSCS). METHOD: All patients presenting with an aSCS were prospectively enrolled in an ongoing institutional database. Inclusion criteria for the Covid-19-aSCS group were a combination of both antigen test and a positive reverse-transcriptase (PCR) test for Covid-19 upon admission. Patients with additional potential etiologies for stroke including cardioembolism, carotid dissection or patients with stenosis of <50% on CTA were excluded. A cohort of non-Covid-19 related aSCS patients admitted to the same institution before the pandemic during 2019 served as controls. RESULTS: Compared to controls (n = 31), Covid-19-aSCS (n = 8), were younger (64.2 ± 10.7 vs 73.5 ± 10, p = 0.027), and less frequently had hypertension (50% vs 90%, p = 0.008) or hyperlipidemia (38% vs 77%, p = 0.029) before admission. Covid-19-aSCS patients had a higher admission NIHSS score (mean 9 ± 7 vs 3 ± 4, p = 0.004) and tended to present more often with stroke (88% vs 55%, p = 0.09) rather than a TIA. Covid-19-aSCS patients had higher rates of free-floating thrombus and clot burden on CTA (88% vs 6.5%, p = 0.002). Covid-19 patients also less often achieved excellent outcomes, with lower percentage of mRS score of 0 after 90-days (13% vs 58%, p = 0.022). CONCLUSION: Covid-19- aSCS may occur in a younger and healthier subpopulation. Covid-19- aSCS patients may have higher tendencies for developing complex clots and less often achieve excellent outcomes.


Asunto(s)
COVID-19 , Estenosis Carotídea , Endarterectomía Carotidea , Accidente Cerebrovascular , Trombosis , Humanos , Estenosis Carotídea/complicaciones , Estenosis Carotídea/diagnóstico por imagen , Factores de Riesgo , COVID-19/complicaciones , Accidente Cerebrovascular/complicaciones , Accidente Cerebrovascular/diagnóstico por imagen , Trombosis/etiología , Trombosis/complicaciones , Resultado del Tratamiento , Endarterectomía Carotidea/efectos adversos , Estudios Retrospectivos , Stents/efectos adversos
9.
Cardiovasc Intervent Radiol ; 45(6): 826-833, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35296934

RESUMEN

PURPOSE: Hemorrhagic transformation (HT) following cerebral endovascular thrombectomy (EVT) for large vessel occlusion (LVO) in acute ischemic stroke is associated with poor outcome. Recent studies have shown that EVT can be efficacious in imaging-selected patients as late as 6-24 h from onset (late time window; LTW). We sought to determine predictors and prognostic implications of HT following EVT in LTW. METHODS: Consecutive patients undergoing EVT for LVO were recruited into a prospective multicenter database. HT was divided into petechial hemorrhagic-infarction and parenchymal hematoma (PH) type 1 or 2 defined as confluent hemorrhage covering < or > than 1/3 of the infarct volume, respectively. Multivariate analyses were performed to determine variables associated with HT subtypes. RESULTS: Among 611 patients included (mean age 70.5 ± 12.5 years; median NIHSS 16), 115 (18.8%) had HT and 33 of them (5.4%) had PH2. Independent PH2 predictors included failed recanalization (OR 7.0, 95% CI 2.3-21.6), longer time from symptom onset to admission (OR 1.002 per minute 95% CI 1.001-1.003) and hyperlipidemia (OR 3.12; 95%CI 1.12-8.7). HT was not associated with outcome. In contrast, PH2 patients had lower favorable outcome rates (14.3 vs 41.6%, p = 0.004) and higher mortality rates (39 vs 17%, p = 0.001). Patients who underwent EVT in the late versus early window had similar PH2 rates (4.5 vs 6.7%, p = 0.27). In multivariate models, PH2 tripled the odds of both 90-day poor outcome (OR 3.1, 95% CI 1.01-9.5) and 90-day mortality (OR 3.2, 95% CI 1.4-7.3). CONCLUSIONS: PH2 following EVT is associated with increased mortality and unfavorable outcome rates. Rates of PH2 are not different between LTW patients and those treated < 6 h from symptom onset.


Asunto(s)
Isquemia Encefálica , Procedimientos Endovasculares , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Anciano , Anciano de 80 o más Años , Isquemia Encefálica/complicaciones , Isquemia Encefálica/diagnóstico por imagen , Isquemia Encefálica/cirugía , Procedimientos Endovasculares/efectos adversos , Hemorragia/etiología , Humanos , Accidente Cerebrovascular Isquémico/diagnóstico por imagen , Accidente Cerebrovascular Isquémico/cirugía , Persona de Mediana Edad , Pronóstico , Estudios Prospectivos , Estudios Retrospectivos , Accidente Cerebrovascular/complicaciones , Accidente Cerebrovascular/diagnóstico por imagen , Accidente Cerebrovascular/cirugía , Trombectomía/efectos adversos , Resultado del Tratamiento
10.
J Neurol Sci ; 432: 120081, 2022 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-34920158

RESUMEN

BACKGROUND: Patients with stroke secondary to occlusions of the anterior cerebral artery (ACA) often have poor outcomes. The optimal acute therapeutic intervention for these patients remains unknown. METHODS: Patients with isolated ACA-stroke were identified from 10 centers participating in the EndoVascular treatment And ThRombolysis in Ischemic Stroke Patients (EVATRISP) prospective registry. Patients treated with endovascular thrombectomy (EVT) were compared to those treated with intravenous thrombolysis (IVT). Odds ratios with 95% confidence intervals (OR; 95%CI) were calculated using multivariate regression analysis. RESULTS: Included were 92 patients with ACA-stroke. Of the 92 ACA patients, 55 (60%) were treated with IVT only and 37 (40%) with EVT (±bridging IVT). ACA patients treated with EVT had more often wake-up stroke (24% vs. 6%, p = 0.044) and proximal ACA occlusions (43% vs. 24%, p = 0.047) and tended to have higher stroke severity on admission [NIHSS: 10.0 vs 7.0, p = 0.054). However, odds for favorable outcome, mortality or symptomatic intracranial hemorrhage did not differ significantly between both groups. Exploration of the effect of clot location inside the ACA showed that in patients with A1 or A2/A3 ACA occlusions the chances of favorable outcome were not influenced by treatment allocation to IVT or EVT. DISCUSSION: Treatment with either IVT or EVT could be safe with similar effect in patients with ACA-strokes and these effects may be independent of clot location within the occluded ACA.


Asunto(s)
Isquemia Encefálica , Procedimientos Endovasculares , Accidente Cerebrovascular , Isquemia Encefálica/complicaciones , Isquemia Encefálica/tratamiento farmacológico , Estudios de Cohortes , Fibrinolíticos/uso terapéutico , Humanos , Reperfusión , Accidente Cerebrovascular/tratamiento farmacológico , Trombectomía , Terapia Trombolítica , Resultado del Tratamiento
11.
J Neurol Sci ; 425: 117450, 2021 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-33878658

RESUMEN

BACKGROUND: Clopidogrel is commonly used for secondary stroke prevention in patients with large vessel stenosis. Reduced Clopidogrel high on treatment platelet reactivity (CR) can lead to Clopidogrel underactivity (CU) causing acute thrombosis. However, the prevalence of CU among patients with acute symptomatic carotid disease remains unknown. Therefore, we aimed to find the prevalence and identify the predictors for CU among patients with acutely symptomatic carotid stenosis. PATIENTS AND METHODS: Over the span of 14 months, CR was measured at the time of endovascular procedure in all patients undergoing angiography and stenting because of acute symptomatic carotid stenosis. Only patients treated per institutional protocol with a combination of Clopidogrel and Aspirin were included. CR was measured with VerifyNowP2Y12 reaction units (PRU) and CU was defined as PRU > 208. Patients with CU were compared to those without CU. RESULTS: Thirty-five patients were included (mean age 71.3 ± 10, 76% men) and twelve (34.3%, mean age 71.8 ± 8.4, 58% men) had CU at the time of endovascular intervention. On univariate analysis more severe carotid stenosis was seen in CU patients (92.6 ± 6.5% vs 81.6 ± 13.6%, p = 0.013) and percent stenosis was independently associated with CU on multivariate analysis (p = 0.023). CONCLUSIONS: CU is present in 1 of every 3 patients with acutely symptomatic carotid disease. The current results suggest that CR testing should become part of routine care in patients with acutely symptomatic carotid disease.


Asunto(s)
Estenosis Carotídea , Accidente Cerebrovascular , Anciano , Anciano de 80 o más Años , Aspirina , Estenosis Carotídea/complicaciones , Estenosis Carotídea/diagnóstico por imagen , Estenosis Carotídea/tratamiento farmacológico , Clopidogrel/uso terapéutico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Inhibidores de Agregación Plaquetaria/uso terapéutico , Stents , Accidente Cerebrovascular/diagnóstico por imagen , Accidente Cerebrovascular/tratamiento farmacológico , Accidente Cerebrovascular/epidemiología , Resultado del Tratamiento
12.
J Exp Med ; 144(1): 259-65, 1976 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-932640

RESUMEN

To determine the extent and nature of individual variation in the development of specific antigen-binding cells, the numbers of cells specific for each of two antigens in the spleens of individual random-bred Swiss-L and inbred CBA/J and BALB/c fetal mice were measured as a function of spleen size. For Swiss-L fetuses, the ratio of antigen-binding cells to nucleateated cells varied more than would arise from sampling fluctuation. For each inbred strain, however, the number of cells specific for a given antigen was a constant proportion of the total number of nucleated cells within sampling error. These proportions varied from antigen to antigen, and from strain to strain. The ratio of the proportions of cells specific for the two antigens, however, differed no more from CBA/J to BALB/c mice than would be expected in repeated samples of cells from the spleen of a single fetus. These results confirm at the level of the individual fetus the uniform pattern of development seen for populations of fetuses. They reveal a surprising precision in the proliferation of specific antigen-binding cell populations and suggest that the development of these cells may be subject to strong genetic controls.


Asunto(s)
Antígenos , Bazo/inmunología , Animales , Sitios de Unión , Eritrocitos/inmunología , Ratones , Ratones Endogámicos , Nitrobencenos/inmunología , Bazo/embriología
13.
J Exp Med ; 146(2): 394-411, 1977 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-69000

RESUMEN

In order to analyze the genetic and physiological basis of controls affecting the generation of the repertoire of antigen-binding cells in fetal mice, we have measured the numbers of spleen cells specific for each of four antigens as a function of the total numbers of nucleated and Ig-bearing cells in inbred, hybrid, and random bred fetuses. For each of the two inbred strains BALB/c and CBA/J, the proportion of nucleated cells specific for a given antigen was the same for all individuals of the strain at the 18th day of gestation. The proportion did vary from antigen to antigen, however, and for each antigen the proportion of specific cells observed in CBA/J fetuses was approximately four times that observed in BALB/c fetuses. This difference appeared to be due to a difference between the two strains in the relative size of the repertoire of antigen-binding spleen cells at this stage of development, inasmuch as the frequency of Ig-bearing spleen cells in CBA/J fetuses was likewise approximately four times that observed in BALB/c fetuses. In random bred Swiss-L fetal mice at the 18th day of gestation, the proportion of cells specific for a given antigen varied significantly from one individual to the next. The ratio of proportions of the two antigens observed was constant from individual to individual, however, and this constant ratio differed significantly from the ratio observed for the same two antigens in fetal BALB/c and CBA/J inbred mice. These data suggest that the ontogeny of the repertoire of antigen-binding cells in fetal mice is subject to at least two independent sets of controls, one affecting the relative size of the repertoire in the spleen, and the other affecting the distribution of antigen-binding specificities within that repertoire. Analysis of repertoire size and composition in the spleens of hybrid fetuses confirmed the observation that the two parameters are controlled independently, and suggested further that the control of repertoire size in these fetuses is due to the action of one or a few closely-linked autosomal Mendelian genes. These data are consistent with models for the origin of antibody diversity in which the genes coding for the full repertoire of antibodies are generated somatically from a small number of germ-line genes early in development and in the absence of any strong positive or negative selection with respect to antigenic specificity.


Asunto(s)
Antígenos , Genes , Bazo/inmunología , Animales , Formación de Anticuerpos , Peso Corporal , Recuento de Células , Mapeo Cromosómico , Epítopos , Feto/inmunología , Hibridación Genética , Técnicas In Vitro , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos CBA , Receptores de Antígenos de Linfocitos B , Bazo/citología , Bazo/embriología
14.
Nicotine Tob Res ; 12(1): 43-52, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19955339

RESUMEN

INTRODUCTION: Discrete classification of smokers by intention to quit is desirable in many public health and clinical settings. METHODS: Two methodological studies examine measurement properties of measures of discrete-time intention to quit smoking used in population-based tobacco surveillance surveys: an ecological comparison of rates of positive intention in relation to the form of measure used and a prospective analysis examining predictive validity of self-reported quit intentions using multiple possible points of dichotomization of an ordinal measure of intention to quit. The prospective analysis used a repeated measures design and follow-up to 1 year for 2,047 smokers in the Ontario Tobacco Survey cohort. RESULTS: The estimated percent of smokers intending to quit was significantly higher using the Stages of Change intention measure, relative to another single question measure. Significant dose-response effects were found. The sooner one intended to quit the more likely one was to make an attempt or achieve at least 30 days abstinence in the next 6 months. Intending to quit in a month or later was not associated with cessation during follow-up among respondents without prior attempts. Examination of cutpoints revealed no value, which maximized both positive and negative prediction. Regardless of quit attempt history, greatest predictive validity was found where respondents stated that they had no intention at all. DISCUSSION: Measures of intentions quit smoking in specific time periods and expressed as dichotomies have limited psychometric properties but utility in applied research. Our findings suggest a possible measurement effect warranting caution in comparisons across studies.


Asunto(s)
Intención , Cese del Hábito de Fumar/psicología , Humanos , Modelos Logísticos , Ontario , Vigilancia de la Población
15.
J Neurol Sci ; 419: 117189, 2020 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-33070002

RESUMEN

BACKGROUND: Cardiac emboli secondary to atrial fibrillation (AF) commonly cause large vessel occlusions (LVO) that require endovascular thrombectomy (EVT) to restore cerebral circulation. Whether the outcome of patients with AF diagnosed after the index stroke (newAF) differs from that of AF-patients in which AF was known before stroke (kAF) remains unknown. PATIENTS AND METHODS: Consecutive LVO patients treated with EVT were recruited and the data was analyzed retrospectively. We compared patients with newAF to those with kAF and those without AF. RESULTS: Among 230 patients included, 109 (47%) had AF (86 kAF, 23 newAF). Patients with kAF more often had prior strokes compared with those with newAF (20% vs. 4% p = 0.04) but other parameters did not differ between the groups. Both AF groups were significantly older, more often reached favorable recanalization and less often had favorable outcomes compared to those without AF. On multivariate analyses, timing of AF detection did not influence survival (Odds Ration [OR] 0.89 95% Confidence Interval [CI] 0.28-1.90), chances for favorable recanalization (OR 1.2 95% CI 0.44-3.26) or favorable outcome 1.32 (95% CI 0.57-3.05). CONCLUSIONS: Timing of AF diagnosis does not appear to influence outcome in patients with LVO that underwent EVT.


Asunto(s)
Fibrilación Atrial , Procedimientos Endovasculares , Accidente Cerebrovascular , Fibrilación Atrial/complicaciones , Fibrilación Atrial/diagnóstico , Fibrilación Atrial/cirugía , Humanos , Estudios Retrospectivos , Accidente Cerebrovascular/complicaciones , Accidente Cerebrovascular/cirugía , Trombectomía , Resultado del Tratamiento
16.
Science ; 269(5222): 341-6, 1995 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-7618100

RESUMEN

Earth's capacity to support people is determined both by natural constraints and by human choices concerning economics, environment, culture (including values and politics), and demography. Human carrying capacity is therefore dynamic and uncertain. Human choice is not captured by ecological notions of carrying capacity that are appropriate for nonhuman populations. Simple mathematical models of the relation between human population growth and human carrying capacity can account for faster-than-exponential population growth followed by a slowing population growth rate, as observed in recent human history.


Asunto(s)
Dinámica Poblacional , Crecimiento Demográfico , Cultura , Ecología , Ambiente , Abastecimiento de Alimentos , Humanos , Matemática , Modelos Estadísticos , Densidad de Población , Abastecimiento de Agua
17.
Science ; 238(4829): 956-60, 1987 Nov 13.
Artículo en Inglés | MEDLINE | ID: mdl-3672136

RESUMEN

In 113 community food webs from natural communities, the average and maximal lengths of food chains are independent of primary productivity, contrary to the hypothesis that longer food chains should arise when more energy is available at their base. Environmental variability alone also does not appear to constrain average or maximal chain length. Environments that are three dimensional or solid, however, such as a forest canopy or the water column of the open ocean, have distinctly longer food chains than environments that are two dimensional or flat, such as a grassland or lake bottom.


Asunto(s)
Ambiente , Abastecimiento de Alimentos , Modelos Biológicos , Animales
18.
Science ; 293(5530): 694-8, 2001 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-11474111

RESUMEN

American trypanosomiasis, or Chagas disease, caused by the protozoan parasite Trypanosoma cruzi and transmitted by blood-feeding triatomine bugs, is a chronic, frequently fatal infection that is common in Latin America. Neither adequate drugs nor a vaccine is available. A mathematical model calibrated to detailed household data from three villages in northwest Argentina shows that householders could greatly reduce the risk of human infection by excluding domestic animals, especially infected dogs, from bedrooms; removing potential refuges for bugs from walls and ceilings; and using domestically applied insecticides. Low-cost, locally practicable environmental management combined with intermittent use of insecticides can sustainably control transmission of T. cruzi to humans in rural Argentina and probably elsewhere.


Asunto(s)
Enfermedad de Chagas/transmisión , Enfermedades de los Perros/epidemiología , Vivienda , Insectos Vectores/fisiología , Modelos Biológicos , Triatoma/fisiología , Animales , Argentina , Sangre , Enfermedad de Chagas/epidemiología , Enfermedad de Chagas/prevención & control , Enfermedad de Chagas/veterinaria , Pollos , Perros , Conducta Alimentaria , Humanos , Insectos Vectores/parasitología , Insecticidas , Matemática , Estaciones del Año , Triatoma/parasitología , Trypanosoma cruzi/fisiología
20.
J Neurol Sci ; 405: 116418, 2019 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-31421309

RESUMEN

BACKGROUND: Cerebral amyloid angiopathy (CAA) typically involves the cerebral cortex but whether it affects the cerebellum remains uncertain. METHODS: Patients with intracerebral hemorrhage (ICH) who underwent magnetic resonance imaging were prospectively enrolled. Patients were diagnosed with CAA according to the Boston criteria and their hemorrhage types were categorized as macro-hematoma (MH) or microbleeds (MB). Patients with CAA and cerebellar involvement were compared with CAA patients without cerebellar involvement. RESULTS: Out of 614 patients with ICH, 85 (14%) had a post-ICH MRI. Of those, 41 (48%) were diagnosed with possible (n = 19), probable (n = 21) or definite (n = 1) CAA. Cerebellar involvement was seen in 14/41 (34%) patients with CAA. Most cerebellar lesions were of the MB type (35%) and most patients had several cerebellar MB typically involving the cerebellar cortex (85%). Patients with cerebellar involvement had larger numbers of lobar MB but clinical variables including age, gender, risk factor profile, mRS scores at 90 days or survival did not differ between those with and without cerebellar involvement. CONCLUSIONS: Cerebellar involvement may be common in CAA. Most patients have multiple superficial cerebellar MB. Clinical characteristics do not differ between CAA patients with or without cerebellar involvement. Patients presenting with cerebellar ICH should be screened for CAA with MRI.


Asunto(s)
Cerebelo/irrigación sanguínea , Cerebelo/diagnóstico por imagen , Angiopatía Amiloide Cerebral/diagnóstico por imagen , Hemorragias Intracraneales/diagnóstico por imagen , Anciano , Estudios de Casos y Controles , Angiopatía Amiloide Cerebral/complicaciones , Femenino , Humanos , Hemorragias Intracraneales/complicaciones , Masculino , Estudios Prospectivos
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