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1.
Occup Med (Lond) ; 70(6): 421-426, 2020 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-32740664

RESUMEN

BACKGROUND: While the potential buffering effects of spirituality are well established in the general population, how spirituality affects those in extremely high-stress occupations like the military and law enforcement is less clear. AIMS: This paper explores the possibility that spiritual influences may operate differently among military veterans than other people. It specifically proposes that attendance at religious services is an especially important buffer for combat veterans. METHODS: This study engaged in a secondary analysis of 74 480 respondents from the National Survey on Drug Use and Health for the years 2013-17. The respondents were split into four groups; veterans with combat experience before September 2001, veterans with combat experience since September 2001, veterans with no combat experience and non-veterans. RESULTS: The likelihood of mental illness decreased in the general population along three different measures of religion; the importance of religion, friendships that shared religious beliefs and attendance at religious services. The relationship was weak and disappeared when controls for non-religion variables were included. A major exception was combat veterans, for whom the religious effects were limited to attendance at services, and the effect survived with the addition of non-religion control variables. CONCLUSIONS: Mental health professionals, chaplains, pastoral counsellors and clergy need to recognize that among the therapeutic benefits of religious attendance and recognize the value of the religious rituals as ends in themselves.


Asunto(s)
Trastornos Mentales/epidemiología , Religión , Veteranos/psicología , Adulto , Conflictos Armados/estadística & datos numéricos , Amigos/psicología , Humanos , Masculino , Encuestas y Cuestionarios , Estados Unidos/epidemiología
2.
Am J Transplant ; 14(5): 1136-41, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24698537

RESUMEN

Chronic inflammation may contribute to human immunodeficiency virus (HIV) persistence through a number of potential pathways. We explored the impact of immunosuppressant therapy on peripheral blood measures of HIV persistence following kidney transplantation. Stored plasma and peripheral blood mononuclear cells prior to transplantation and at weeks 12, 26, 52 and 104 posttransplant were obtained from 91 transplant recipients. In a multivariate model, higher pretransplant plasma HIV RNA level (p < 0.0001) and a longer duration of follow-up posttransplant (p = 0.09) were associated with higher posttransplant plasma HIV RNA levels. A higher baseline HIV DNA (p < 0.0001) was significantly associated with higher HIV DNA levels posttransplant, while higher CD4+ T cell count (p = 0.001), sirolimus use (p = 0.04) and a longer duration of follow-up (p = 0.06) were associated with lower posttransplant HIV DNA levels. The association between sirolimus exposure and lower frequency of cells containing HIV DNA levels posttransplant suggest that the immune-modifying drugs may affect the level of HIV persistence during effect therapy. Future studies of sirolimus as a reservoir-modifying agent are warranted.


Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Supervivencia de Injerto/efectos de los fármacos , Infecciones por VIH/prevención & control , Inmunosupresores/uso terapéutico , Fallo Renal Crónico/cirugía , Trasplante de Riñón , Femenino , Estudios de Seguimiento , VIH/genética , VIH/aislamiento & purificación , VIH/metabolismo , Infecciones por VIH/inmunología , Infecciones por VIH/virología , Humanos , Fallo Renal Crónico/complicaciones , Fallo Renal Crónico/virología , Leucocitos Mononucleares/efectos de los fármacos , Leucocitos Mononucleares/inmunología , Leucocitos Mononucleares/virología , Masculino , Persona de Mediana Edad , Pronóstico , ARN Viral/sangre , Estudios Retrospectivos , Tasa de Supervivencia , Receptores de Trasplantes
3.
bioRxiv ; 2024 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-39386434

RESUMEN

Fireflies use bioluminescent signals to communicate with their mates. Luciferase has been thought to be the sole contributor to light color; however, populations of the Photinus pyralis firefly display variation in the color of their emitted signals yet have identical luciferase sequences. Here, we examined whether pigments could be present in the light organs of the twilight-active species P. pyralis and contribute to this variation. We detected patterns of expression that suggest ommochrome and pterin screening pigments are expressed in P. pyralis light organs and could filter light emitted by luciferase and play a role in signal tuning. There were no significant differences between the pigment gene expression of P. pyralis individuals with yellower and greener signals. Our study provides alternative mechanisms that could influence pigments in P. pyralis light organs that could also play a role in modifying signal color.

4.
J Cereb Blood Flow Metab ; 5(1): 79-85, 1985 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-3919037

RESUMEN

A group of 51 neurologically normal, middle-aged and elderly volunteers (aged 35-86 years; mean age 63.24 years) with and without risk factors for stroke were given annual tests of cerebral vasomotor reactivity to assess any changes in the cerebral vascular capacitance associated with advancing age that might alter cerebral vasomotor reactivity. Cerebral vasomotor reactivity was estimated as the difference in bihemisphere gray matter CBF measured by the 133Xe inhalation method in the steady state breathing room air, followed by a second measurement during inhalation of 100% oxygen. There were significant and progressive reductions in cerebral vasomotor reactivity during the 4-year longitudinal study. Positive linear correlations were apparent between initial steady-state mean bihemisphere gray matter CBF levels and degrees of vasomotor reactivity, suggesting that the Law of Initial Value plays an important role. This should be borne in mind when analyzing scores of cerebral vasomotor reactivity. In the present communication, analysis of covariance was used to correct for influences of initial CBF levels on vasomotor responses tested while breathing pure oxygen.


Asunto(s)
Envejecimiento , Encéfalo/fisiología , Circulación Cerebrovascular , Sistema Vasomotor/fisiología , Anciano , Dióxido de Carbono , Femenino , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Consumo de Oxígeno , Estudios Prospectivos
5.
J Cereb Blood Flow Metab ; 5(3): 376-85, 1985 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-4030916

RESUMEN

Nineteen patients with sudden onset of impaired recent memory, cerebellar ataxia, peripheral neuropathy, and other signs of Wernicke-Korsakoff syndrome (WKS) were treated and examined prospectively for 3 months. Serial studies included histories, neurological examinations, cognitive capacity screening examinations (CCSE), computed tomography (CT) scans, and measurements of regional CBF. Patients were detoxified and withdrawn from sedatives before CBF measurements were examined. Treatment included alcohol withdrawal, nutritious diet, and 300 mg thiamine daily. Before treatment CCSE scores and blood flow values of both white and gray matter were reduced, particularly within both temporoparietal regions. After treatment of compliant patients (n = 10), white and gray matter blood flow increased concurrently with improved CCSE scores. Abnormal eye signs, ataxia, peripheral neuropathy, and performance of activities of daily living also improved. Cerebral atrophy and ventricular enlargement measured by CT decreased. Early recognition and treatment of WKS in compliant patients permit rapid reversals of cognitive and neurological impairments associated with increased blood flow of gray and white matter and improvements of brain atrophy measured by CT scanning.


Asunto(s)
Trastorno Amnésico Alcohólico/terapia , Circulación Cerebrovascular , Adulto , Anciano , Trastorno Amnésico Alcohólico/dietoterapia , Trastorno Amnésico Alcohólico/tratamiento farmacológico , Trastorno Amnésico Alcohólico/fisiopatología , Alcoholismo/fisiopatología , Atrofia , Encéfalo/patología , Humanos , Masculino , Persona de Mediana Edad , Tiamina/uso terapéutico
6.
J Cereb Blood Flow Metab ; 6(1): 86-94, 1986 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-3944220

RESUMEN

Twenty severe chronic alcoholic patients with signs of neurotoxicity but without Wernicke-Korsakoff syndrome were treated by abstinence from alcohol and examined prospectively at intervals thereafter. Serial examinations included detailed medical histories, neurological examinations, cognitive capacity screening examinations, computed tomography scans with measurements of sulcal and ventricular volume, and measurements of regional CBF. All sedatives were withdrawn before CBF measurements were made. Before treatment, gray matter blood flow values were significantly reduced compared with those of age-matched normal volunteers, but white matter blood flow values were normal and the ventricles were enlarged. After abstinence from alcohol, mean gray matter blood flow values and brain volume both increased significantly.


Asunto(s)
Encéfalo/fisiopatología , Circulación Cerebrovascular , Templanza , Adulto , Anciano , Trastorno Amnésico Alcohólico/fisiopatología , Etanol/efectos adversos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Enfermedades del Sistema Nervioso/inducido químicamente
7.
Arch Neurol ; 44(4): 418-22, 1987 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-3827697

RESUMEN

Possible effects of chronically elevated serum cholesterol and triglyceride levels on measurements of cerebral blood flow were investigated by between-group comparisons of individuals, with and without hyperlipidemia, among 56 neurologically normal elderly volunteers and among 102 age-matched patients with symptoms of transient ischemic attacks (TIAs). Results demonstrated significantly higher levels of serum cholesterol and triglyceride among the TIA patients compared with randomly selected age-matched normal controls of similar educational and environmental backgrounds. Cerebral blood flow levels were reduced among groups of TIA patients with elevated levels of either cholesterol or triglycerides compared with the TIA patients with normal lipid levels. Similar trends were seen among normal volunteers, but these did not reach levels of statistical significance because of the limited numbers available. Analysis of frequency distributions for risk factors other than hyperlipidemia indicated that hypertension, atherosclerotic heart disease, diabetes mellitus, and cigarette smoking were also more prevalent among TIA patients than among age-matched normal controls.


Asunto(s)
Trastornos Cerebrovasculares/etiología , Hiperlipidemias/complicaciones , Ataque Isquémico Transitorio/etiología , Anciano , Presión Sanguínea , Colesterol/sangre , Femenino , Humanos , Masculino , Persona de Mediana Edad , Riesgo , Triglicéridos/sangre
8.
Arch Neurol ; 47(1): 33-7, 1990 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-2294891

RESUMEN

Magnetoencephalography offers the possibility of localizing accurately and noninvasively the source of intracranial currents associated with normal and abnormal brain activity. The purpose of this study was to assess the validity and across-subject reliability of localization of cortical sources responding to ipsilateral and contralateral auditory stimulation. Magnetic evoked fields to both stimulation conditions were measured in eight consecutive normal subjects, and the cortical sources of these fields were estimated on the basis of these measurements. Subsequent projection of the source location coordinates onto magnetic resonance images showed that in all subjects the sources were accurately estimated to fall in the vicinity of the auditory cortex and that two separate sources may account for the response to ipsilateral and contralateral stimulation.


Asunto(s)
Encéfalo/fisiología , Potenciales Evocados Auditivos/fisiología , Imagen por Resonancia Magnética/métodos , Magnetoencefalografía/métodos , Estimulación Acústica/métodos , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Valores de Referencia , Reproducibilidad de los Resultados
9.
Arch Neurol ; 42(12): 1169-75, 1985 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-2933014

RESUMEN

Brain atrophy estimated by computed tomographic (CT) scanning and mean hemispheric and regional gray matter cerebral blood flow (CBF) values were measured in patients with mild to moderate Huntington's disease (HD) (N = 16) using the xenon Xe 133 inhalation method and in asymptomatic blood relatives at risk from HD (N = 6) using both the xenon Xe 133 inhalation and the stable xenon CT contrast CBF methods. Results were compared with measurements in two groups of age-matched normal volunteers (N = 48 and N = 42, respectively). Significant brain atrophy in the vicinity of both caudate nuclei was present in patients with HD but not in at-risk individuals. Mean hemispheric xenon Xe 133 CBF values were reduced in patients with HD but seemed to be normal in at-risk individuals. In HD, reductions in CBF were found in both frontotemporal regions. Correlations were found between severity of dementia estimated by reductions of Mini-Mental Status Questionnaire scores and reductions of either mean hemispheric or regional frontotemporal CBF values in HD. The CT estimates of brain atrophy and three-dimensional CBF by stable xenon-contrast measurements were normal in asymptomatic individuals at risk from HD.


Asunto(s)
Circulación Cerebrovascular , Cognición , Enfermedad de Huntington/fisiopatología , Pruebas Psicológicas , Adulto , Anciano , Atrofia , Encéfalo/patología , Femenino , Humanos , Enfermedad de Huntington/diagnóstico por imagen , Enfermedad de Huntington/patología , Enfermedad de Huntington/psicología , Masculino , Persona de Mediana Edad , Radiografía
10.
Neurology ; 44(7): 1283-6, 1994 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-8035931

RESUMEN

We studied evoked magnetic fields and electrical potentials following stimulation of the tibial nerve in a group of 24 normal subjects. Both magnetic and electrical recordings demonstrated a series of oscillatory patterns consisting of four peaks (two positive and two negative) occurring between 40 and 100 msec. Magnetic field source localization of all four peaks using a dipole-in-a-sphere model indicated that all four peaks emanated from the same cortical surface located within the longitudinal fissure, an area typically associated with somatosensory function.


Asunto(s)
Potenciales Evocados Somatosensoriales , Nervio Tibial/fisiología , Adulto , Encéfalo/anatomía & histología , Estimulación Eléctrica , Femenino , Humanos , Imagen por Resonancia Magnética , Magnetismo , Masculino , Persona de Mediana Edad , Oscilometría
11.
Neurology ; 36(1): 1-6, 1986 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-3941761

RESUMEN

A 7-year prospective study among 181 neurologically normal elderly volunteers (mean age, 70.6 years) revealed an incidence of 3.3%, or 0.47% new cases per year, for Alzheimer's disease (SDAT) and 5.5%, or 0.78% new cases per year, for multi-infarct dementia (MID). The unusually high incidence of MID is considered to reflect preselection of a large percentage of volunteers (48.6%) with risk factors for (but without symptoms of) atherothrombotic stroke. Of 88 volunteers at risk of stroke, 11.4% developed MID within 7 years. In MID patients, cerebral blood flow (CBF) values began to decline around 2 years before onset of symptoms, while in SDAT patients, CBF levels remained normal until symptoms of dementia appeared; thereafter, CBF declined rapidly.


Asunto(s)
Enfermedad de Alzheimer/fisiopatología , Circulación Cerebrovascular , Demencia/fisiopatología , Anciano , Enfermedad de Alzheimer/diagnóstico por imagen , Análisis de Varianza , Demencia/diagnóstico por imagen , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Riesgo , Tomografía Computarizada por Rayos X
12.
Neurology ; 34(7): 855-62, 1984 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-6539861

RESUMEN

Cross-sectional analysis of CBF values was carried out among 668 volunteers and patients. Subjects were subdivided according to age, gender, and degree of cerebrovascular disease, ranging from healthy volunteers with or without risk factors for stroke to patients with multi-infarct dementia. Four-year longitudinal analysis was also carried out on 230 individuals from the original sample. Decrements in CBF values were evidenced by both cross-sectional and longitudinal analysis in relation to advancing age, progressive cerebrovascular disease, and dementia. Regional, age-related CBF declines in healthy volunteers were heterogeneous, possibly related to changes in levels of functional activity within different brain regions.


Asunto(s)
Circulación Cerebrovascular , Trastornos Cerebrovasculares/fisiopatología , Ataque Isquémico Transitorio/fisiopatología , Anciano , Envejecimiento , Femenino , Humanos , Masculino , Persona de Mediana Edad
13.
J Am Geriatr Soc ; 36(1): 13-21, 1988 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-2961795

RESUMEN

In order to standardize and quantify diagnostic information derived from medical histories and case reports given by demented patients, their families or care-providers, a questionnaire has been developed containing 94 questions. The output is categorized by computer into graphic clinical scales which correlate and weigh information relating to seven of the most common causes of dementia. The present investigation assesses the validity of predictive diagnostic classifications derived from the clinical scales tested on admission by correlating them later with final diagnoses determined independently by thorough clinical evaluation including standard diagnostic tests, computed tomography and nuclear magnetic resonance scans. Results of 101 healthy, neurologically normal, age-matched volunteers and 140 patients representative of the more common forms of dementia indicate that correct diagnostic identification was: 75% for dementia secondary to Parkinson's disease, 100% for Huntington's disease, 90.2% for Alzheimer's disease, 82.4% for multi-infarct dementia, 90.0% for posttraumatic dementia, 77.8% for normal-pressure hydrocephalus and 85.7% for Wernicke-Korsakoff dementia. Correct diagnostic assignment was highly significant (P less than .0005). The screening questionnaire may prove to be a useful and standard diagnostic tool for clinicians and investigators concerned with epidemiology, prevention and treatment of dementia.


Asunto(s)
Demencia/diagnóstico , Diagnóstico por Computador , Adulto , Anciano , Enfermedad de Alzheimer/complicaciones , Demencia/etiología , Femenino , Humanos , Enfermedad de Huntington/complicaciones , Masculino , Persona de Mediana Edad , Enfermedad de Parkinson/complicaciones , Autoevaluación (Psicología) , Encuestas y Cuestionarios
14.
J Am Geriatr Soc ; 38(2): 123-8, 1990 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-2299115

RESUMEN

Among neurologically normal volunteers approaching age 65 with an option for retirement, a four-year prospective longitudinal study was designed to examine effects of different levels of physical activity on cerebral perfusion by between-group comparisons. After the fourth year, cognitive performance was also tested. Three groups were compared, each composed of 30 elderly volunteers, assigned as follows: Group 1, who continued to work; Group 2, who retired but participated in regular physical activities; and Group 3, who retired but did not participate in regular, planned physical activities. Retirees who elected to become physically inactive exhibited significant declines in cerebral blood flow (CBF) throughout four years of follow-up. Those who continued to work or retirees who elected to participate in regular activities sustained more constant CBF levels. Active retirees and those who continued to work also scored better on cognitive testing after the fourth year of follow-up compared to inactive retirees.


Asunto(s)
Circulación Cerebrovascular , Cognición , Ejercicio Físico , Jubilación , Anciano , Empleo , Femenino , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Estudios Prospectivos
15.
J Am Geriatr Soc ; 33(6): 413-21, 1985 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-3998351

RESUMEN

Local cerebral blood flow (LCBF) and local tissue:blood partition, coefficient (L lambda) values were measured during CT scanning while patients with different types of Parkinson's syndrome (N = 14) inhaled a contrast mixture of 35-37 per cent stable xenon gas in oxygen. Single-compartment analysis fitted to infinity was used to calculate L lambda and LCBF values. Results were compared with results from normal age-matched volunteers (N = 24). Mean hemispheric (p less than 0.05) and subcortical (p less than 0.05) gray matter LCBF values were reduced in idiopathic Parkinson's disease (N = 11), compared to values from age-matched normals. Regionally, LCBF reductions included frontal (p less than 0.001), parietal cortex (p less than 0.05), caudate (p less than 0.05), lentiform nuclei (p less than 0.001) and thalamus (p less than 0.05) reductions. L lambda values were normal. Unilateral tremor and/or rigidity correlated directly with reduced LCBF in contralateral lentiform (p less than 0.01) and caudate (p less than 0.01) nuclei. In postencephalitic Parkinsonism (N = 1) LCBF reductions were diffuse, with normal L lambda values. In the akinetic form of Parkinsonism (N = 1) associated with lacunar infarcts, LCBF and L lambda reductions were patchy. In Parkinsonism following carbon monoxide poisoning (N = 1), LCBF values of gray and white matter were diffusely reduced and L lambda values were reduced in both pallidal regions. When dementia was present together with Parkinsonism (N = 3), LCBF reductions were more diffuse and severe. Dopaminergic deficiency correlated directly with reduced LCBF values, reflecting the severity of Parkinsonism.


Asunto(s)
Envejecimiento , Circulación Cerebrovascular , Enfermedad de Parkinson/fisiopatología , Tomografía Computarizada por Rayos X , Adulto , Anciano , Encéfalo/fisiopatología , Intoxicación por Monóxido de Carbono/fisiopatología , Núcleo Caudado/irrigación sanguínea , Núcleo Caudado/fisiopatología , Corteza Cerebral/irrigación sanguínea , Corteza Cerebral/fisiopatología , Demencia/fisiopatología , Dopamina/fisiología , Femenino , Lateralidad Funcional , Humanos , Masculino , Persona de Mediana Edad , Rigidez Muscular/fisiopatología , Tálamo/irrigación sanguínea , Tálamo/fisiopatología , Temblor/fisiopatología , Xenón
16.
J Am Geriatr Soc ; 37(6): 549-55, 1989 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-2654259

RESUMEN

Seventy multi-infarct dementia patients were randomized into an aspirin-treated group and an untreated control group for an exploratory investigation to determine any effects of 325 mg aspirin daily on cognitive performance. The control group did not receive placebo but evaluations were carried out in a blinded manner. The index group (N = 37, mean age 67.1 years) received 325 mg of aspirin by mouth once daily while the control group (N = 33, mean age 67.6 years) was followed and treated in a similar manner except that they received no aspirin. Both groups had comparable risk factors for stroke, which were treated similarly, as well as comparable initial cerebral blood flow values, as measured by the 133xenon inhalation method, and initial scores on Cognitive Capacity Screening Examination testing. Patients were evaluated at intervals of one year. Significant improvements were demonstrated for cerebral perfusion values (P less than .0001) and cognitive performance scores (P less than .0001) among aspirin-treated patients compared to untreated controls at each of three annual follow-up evaluations. Both men and women benefited from aspirin therapy and their quality of life and independence appeared to be improved, which was not apparent in the control group. Daily aspirin appears to improve or stabilize declines in cerebral perfusion and cognition among patients with multi-infarct dementia.


Asunto(s)
Aspirina/uso terapéutico , Demencia por Múltiples Infartos/tratamiento farmacológico , Anciano , Circulación Cerebrovascular/efectos de los fármacos , Ensayos Clínicos como Asunto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Proyectos Piloto , Distribución Aleatoria , Factores de Riesgo
17.
J Am Geriatr Soc ; 32(2): 114-20, 1984 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-6693696

RESUMEN

Regional cerebral blood flow values were measured utilizing the 133Xe inhalation method in patients with multi-infarct dementia (MID) (n = 22, age 67.4 +/- 9.8 years), in patients with senile dementia of Alzheimer type (SDAT) (n = 36, age 63.8 +/- 8.0) and in age-matched normal healthy volunteers (n = 50, age 67.5 +/- 9.3). Mean hemispheric gray matter flow values were significantly reduced in MID (P less than 0.01) and SDAT (P less than 0.01) patients compared with age-matched normal volunteers. In normal volunteers, mean flow values showed gradual declines with advancing age (r = -0.44, P less than 0.005). In MID patients there were significant decreases in flow values with advancing age (r = -0.43, P less than 0.05), but flow values were consistently lower than in age-matched normals. Reductions of flow were most evident in the distribution of both middle cerebral arteries. Unlike MID patients, patients with SDAT had diffusely reduced flow values over all age ranges without correlation with advancing age. Reductions of mean flow values in both dementia groups were significantly correlated with severity of dementia (P less than 0.05 for both groups). Cerebral blood flow reductions related to the aging process also contribute to decreased cerebral perfusion in patients with MID. This is not true in SDAT, where the disease process itself pre-empts cerebral blood flow reductions attributable to aging.


Asunto(s)
Envejecimiento , Circulación Cerebrovascular , Demencia/fisiopatología , Factores de Edad , Anciano , Isquemia Encefálica/fisiopatología , Infarto Cerebral/fisiopatología , Femenino , Humanos , Masculino , Persona de Mediana Edad
18.
J Am Geriatr Soc ; 32(6): 415-20, 1984 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-6427316

RESUMEN

Effects of chronic cigarette smoking on cerebrovascular responsiveness of volunteers at risk for stroke and not at risk for stroke were evaluated by serial measurements of cerebral blood flow using the 133Xe inhalation method. Resting gray matter blood flow values (Fg) measured while breathing room air were compared with Fg values measured during inhalation of either 5 per cent CO2 in air or 100 per cent O2. Changes in Fg values during inhalation of 5 per cent CO2 were used to estimate cerebral vasodilator capacitance, and those during inhalation of 100 per cent O2 were used to estimate cerebral vasoconstrictor capacitance. Results indicated that chronic cigarette smokers have both reduced vasodilator (P less than 0.01) and reduced vasoconstrictor (P less than 0.02) capacitance when compared with nonsmokers of the same ages regardless of whether or not other risk factors for stroke were present. Vasodilator capacitance to 5 per cent CO2 inhalation was reduced among smokers compared with nonsmokers of the same age by 48 per cent in non-risk subjects and 56 per cent in risk-factored subjects, while vasoconstrictor capacitance to 100 per cent O2 inhalation among smokers was decreased by 24 per cent in non-risk subjects and 34 per cent in risk-factored subjects. In risk-factored subjects, combined effects of smoking and other risks appeared to be additive.


Asunto(s)
Dióxido de Carbono/fisiología , Circulación Cerebrovascular , Oxígeno/fisiología , Respiración , Fumar , Anciano , Trastornos Cerebrovasculares/diagnóstico , Trastornos Cerebrovasculares/fisiopatología , Humanos , Persona de Mediana Edad , Riesgo , Vasoconstricción , Vasodilatación
19.
J Am Geriatr Soc ; 31(9): 540-3, 1983 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-6886280

RESUMEN

Neurotoxic effects of habitual alcohol consumption were investigated by correlating the subjects' estimates of abstinence or frequency and amount of alcohol consumed with measurements of gray matter blood flow utilizing the 133Xe inhalation method. Two hundred and twenty-two subjects were studied, including 136 healthy subjects, 82 subjects with well-established risk factors for stroke (hypertension, hyperlipidemia, heart disease, and diabetes mellitus), and four subjects with chronic alcoholic dementia of the Wernicke-Korsakoff type. Subjects were classified according to average quantitative amounts of alcohol consumed per day, week, or month for the past five years. Comparisons of mean values for hemispheric gray matter blood flow indicated significant inverse relationships with the average amounts of alcohol consumed. This linear relationship occurred regardless of whether or not other risk factors were present and indicated that alcohol itself was a risk factor reducing gray matter blood flow and had additive effects of reducing cerebral blood flow further when combined with other risk factors. Patients who had chronic Wernicke-Korsakoff syndrome had the most severely reduced blood flow levels, as might be predicted from extrapolation of the regression line comparing cerebral blood flow values with the degree of chronic alcohol consumption.


Asunto(s)
Consumo de Bebidas Alcohólicas , Intoxicación Alcohólica , Circulación Cerebrovascular/efectos de los fármacos , Anciano , Demencia/inducido químicamente , Relación Dosis-Respuesta a Droga , Etanol , Femenino , Humanos , Masculino , Persona de Mediana Edad , Flujo Sanguíneo Regional , Factores de Tiempo
20.
J Am Geriatr Soc ; 34(5): 355-60, 1986 May.
Artículo en Inglés | MEDLINE | ID: mdl-3958410

RESUMEN

Cerebral blood flow (CBF) was measured by the 133Xe inhalation method in patients with multi-infarct dementia (MID, N = 26), Alzheimer's dementia (AD, N = 19), and among age-matched, neurologically normal, healthy volunteers (N = 26). Cognitive performance was assessed in all subjects using the Cognitive Capacity Screening Examination (CCSE). Cerebral vasomotor responses were calculated from differences in values of mean hemispheric gray matter blood flow (Delta CBF) measured during inhalation of 100% oxygen (hyperoxia) compared with CBF measured while breathing room air. Significant correlations were found between CCSE performance and vasomotor responsiveness in patients with MID (P less than .01), but not in patients with AD or in neurologically normal volunteers. Loss of vasomotor responsiveness is an indicator of cerebrovascular disease with rigidity and/or loss of reactivity of cerebral vessels, which impairs cerebrovascular responses to situational demands and predisposes to cerebral ischemia. Loss of cerebral vasomotor responsiveness among MID patients, which is a biologic marker of cerebrovascular disease, provides confirmatory evidence of the vascular etiology of MID and assists in separating MID from AD patients.


Asunto(s)
Circulación Cerebrovascular , Trastornos del Conocimiento/diagnóstico , Demencia/fisiopatología , Anciano , Enfermedad de Alzheimer/fisiopatología , Enfermedad de Alzheimer/psicología , Trastornos del Conocimiento/etiología , Trastornos del Conocimiento/fisiopatología , Demencia/psicología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Oxígeno , Escalas de Valoración Psiquiátrica , Vasoconstricción , Radioisótopos de Xenón
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