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1.
Ann Behav Med ; 52(10): 830-841, 2018 09 13.
Artículo en Inglés | MEDLINE | ID: mdl-30212844

RESUMEN

Background: Chronic stress plays a critical role in many of today's diseases and causes of death. Tobacco use reliably increases the likelihood of chronic disease development and premature death. In addition, habitual tobacco use elevates risk of chronic inflammatory diseases, and glucocorticoid therapy is often less effective in smokers compared with nonsmokers. Taken together, smokers may develop glucocorticoid insensitivity, thereby removing the body's greatest anti-inflammatory mechanism. Purpose: The purpose of this study was to examine glucocorticoid sensitivity among 24 smokers and 24 age-, sex-, and body mass index-matched never smokers who were clinically healthy individuals (i.e., no diagnosis or medication use for chronic diseases and normotensive). Method: Participants visited the lab after a 12 hr fast, provided a blood sample, and completed a series of psychosocial questionnaires. Smokers continued smoking ad libitum before the lab visit. Group differences in glucocorticoid sensitivity were examined using ANCOVA and repeated with linear mixed model to account for possible dependence among immune outcomes that matching participants on age, sex, and body mass index may have introduced. Results: Prior to clinical disease onset, smokers' peripheral blood mononuclear cells (PBMCs) exhibited reduced glucocorticoid sensitivity as well as a diminished inflammatory response to lipopolysaccharide compared with never smokers' PBMCs; results were identical regardless of statistical modeling used. Conclusions: Cigarette smoking, a self-initiated pharmacological chronic stressor, may provide a unique opportunity to examine early wear and tear on physiological functioning that may lead to chronic disease development. Additional research into PBMCs' intracellular changes must be examined as well as repeating this study in a larger, more heterogeneous population.


Asunto(s)
Fumar Cigarrillos/efectos adversos , Fumar Cigarrillos/inmunología , Glucocorticoides/farmacología , Leucocitos Mononucleares/efectos de los fármacos , Leucocitos Mononucleares/inmunología , Adulto , Enfermedad Crónica , Femenino , Humanos , Masculino
2.
Nature ; 454(7204): 622-5, 2008 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-18668105

RESUMEN

Partial melting in the Earth's mantle plays an important part in generating the geochemical and isotopic diversity observed in volcanic rocks at the surface. Identifying the composition of these primary melts in the mantle is crucial for establishing links between mantle geochemical 'reservoirs' and fundamental geodynamic processes. Mineral inclusions in natural diamonds have provided a unique window into such deep mantle processes. Here we provide experimental and geochemical evidence that silicate mineral inclusions in diamonds from Juina, Brazil, crystallized from primary and evolved carbonatite melts in the mantle transition zone and deep upper mantle. The incompatible trace element abundances calculated for a melt coexisting with a calcium-titanium-silicate perovskite inclusion indicate deep melting of carbonated oceanic crust, probably at transition-zone depths. Further to perovskite, calcic-majorite garnet inclusions record crystallization in the deep upper mantle from an evolved melt that closely resembles estimates of primitive carbonatite on the basis of volcanic rocks. Small-degree melts of subducted crust can be viewed as agents of chemical mass-transfer in the upper mantle and transition zone, leaving a chemical imprint of ocean crust that can possibly endure for billions of years.

3.
Clin Oncol (R Coll Radiol) ; 35(6): e352-e361, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37031075

RESUMEN

AIMS: Clinical equipoise exists regarding early-stage lung cancer treatment among patients as trials comparing stereotactic body radiation therapy (SBRT) and surgical resection are unavailable. Given the potential differences in treatment effectiveness and side-effects, we sought to determine the associations between treatment type, decision regret and depression. MATERIALS AND METHODS: A multicentre, prospective study of patients with stage IA-IIA non-small cell lung cancer (NSCLC) with planned treatment with SBRT or surgical resection was conducted. Decision regret and depression were measured using the Decision Regret Scale (DRS) and Patient Health Questionnaire-4 (PHQ-4) at 3, 6 and 12 months post-treatment, respectively. Mixed linear regression modelling examined associations between treatment and decision regret adjusting for patient sociodemographics. RESULTS: Among 211 study participants with early-stage lung cancer, 128 (61%) patients received SBRT and 83 (39%) received surgical resection. The mean age was 73 years (standard deviation = 8); 57% were female; 79% were White non-Hispanic. In the entire cohort at 3 months post-treatment, 72 (34%) and 57 (27%) patients had mild and severe decision regret, respectively. Among patients who received SBRT or surgery, 71% and 46% of patients experienced at least mild decision regret at 3 months, respectively. DRS scores increased at 6 months and decreased slightly at 12 months of follow-up in both groups. Higher DRS scores were associated with SBRT treatment (adjusted mean difference = 4.18, 95% confidence interval 0.82 to 7.54) and depression (adjusted mean difference = 3.49, 95% confidence interval 0.52 to 6.47). Neither patient satisfaction with their provider nor decision-making role concordance was associated with DRS scores. CONCLUSIONS: Most early-stage lung cancer patients experienced at least mild decision regret, which was associated with SBRT treatment and depression symptoms. Findings suggest patients with early-stage lung cancer may not be receiving optimal treatment decision-making support. Therefore, opportunities for improved patient-clinician communication probably exist.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Radiocirugia , Humanos , Femenino , Anciano , Masculino , Carcinoma de Pulmón de Células no Pequeñas/radioterapia , Carcinoma de Pulmón de Células no Pequeñas/cirugía , Carcinoma de Pulmón de Células no Pequeñas/patología , Neoplasias Pulmonares/radioterapia , Neoplasias Pulmonares/cirugía , Neoplasias Pulmonares/patología , Estudios Prospectivos , Resultado del Tratamiento , Radiocirugia/efectos adversos , Emociones , Estadificación de Neoplasias
4.
Ann Oncol ; 23(2): 382-7, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21804051

RESUMEN

BACKGROUND: Integration of palliative care with standard oncologic care improves quality of life and survival of lung cancer patients. We surveyed physicians to identify factors influencing their decisions for referral to palliative care. METHODS: We provided a self-administered questionnaire to physicians caring for lung cancer patients at five medical centers. The questionnaire asked about practices and views with respect to palliative care referral. We used multiple regression analysis to identify predictors of low referral rates (<25%). RESULTS: Of 155 physicians who returned survey responses, 75 (48%) reported referring <25% of patients for palliative care consultation. Multivariate analysis, controlling for provider characteristics, found that low referral rates were associated with physicians' concerns that palliative care referral would alarm patients and families [odds ratio (OR) 0.45, 95% confidence interval (CI) 0.21-0.98], while the belief that palliative care specialists have more time to discuss complex issues (OR 3.07, 95% CI 1.56-6.02) was associated with higher rates of referral. CONCLUSIONS: Although palliative care consultation is increasingly available and recommended throughout the trajectory of lung cancer, our data indicate it is underutilized. Understanding factors influencing decisions to refer can be used to improve integration of palliative care as part of lung cancer management.


Asunto(s)
Neoplasias Pulmonares/terapia , Cuidados Paliativos/estadística & datos numéricos , Práctica Profesional , Derivación y Consulta/estadística & datos numéricos , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Análisis de Regresión , Encuestas y Cuestionarios
5.
Science ; 202(4365): 322-4, 1978 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-211589

RESUMEN

After 3 weeks of twice-daily administration of desipramine to rats, the frequency-response curve for field stimulation of adrenergic neurons in isolated left atrial strips was shifted markedly to the left and the efflux of [3H]norepinephrine was enhanced greatly. After 1 day of treatment, only slight shifts in the frequency-response curve and small increases in [3H]norepinephrine efflux occurred although inhibition of [3H]norepinephrine uptake was already maximal, and phenoxybenzamine caused a further shift to the left in the frequency-response curve similar to that which occurred after 3 weeks of desipramine treatment alone. A gradual decrease in the sensitivity of the presynaptic alpha receptor would explain the delay in the onset of the linical effect of the tricyclic antidepressants.


Asunto(s)
Desipramina/farmacología , Norepinefrina/metabolismo , Receptores Adrenérgicos alfa/efectos de los fármacos , Receptores Adrenérgicos/efectos de los fármacos , Transmisión Sináptica/efectos de los fármacos , Animales , Técnicas In Vitro , Cinética , Unión Neuromuscular/efectos de los fármacos , Norepinefrina/farmacología , Fenoxibenzamina/farmacología , Ratas , Receptores Adrenérgicos beta/efectos de los fármacos , Membranas Sinápticas/efectos de los fármacos , Factores de Tiempo
6.
Science ; 170(3962): 1106-8, 1970 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-5475637

RESUMEN

Morphine sulfate increased the incorporation of carbon-14-labeled tyrosine into labeled catecholamines in the mouse brain. Tolerance was manifested by a shift to the right in the dose-response curve for morphine after mice were treated repeatedly with morphine. Naloxone, a specific morphine antagonist, also shifted the dose-response curve for morphine to the right.


Asunto(s)
Química Encefálica/efectos de los fármacos , Catecolaminas/biosíntesis , Tolerancia a Medicamentos , Morfina/farmacología , Animales , Isótopos de Carbono , Inyecciones Intraperitoneales , Ratones , Antagonistas de Narcóticos/farmacología , Tirosina/metabolismo
7.
Science ; 205(4407): 723-5, 1979 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-462184

RESUMEN

Physiological stimulation of the hypothalamo-neurohypophysial system by salt loading of rats resulted in a dramatically increased glucose utilization in the posterior pituitary but not in the paraventricular or supraoptic nuclei. The good correlation between glucose utilization and neural activity in the posterior pituitary (that is, nerve terminals) contrasted with the lack of correlation in the paraventricular and supraoptic nuclei (that is, the sites of the cell bodies of the same neurons). This difference in the metabolic response to functional activity between the two regions of these neurons can be explained by the differences in surface-to-volume ratios of these regions.


Asunto(s)
Metabolismo Energético , Sistema Hipotálamo-Hipofisario/metabolismo , Animales , Axones/metabolismo , Desoxiglucosa/metabolismo , Metabolismo Energético/efectos de los fármacos , Masculino , Terminaciones Nerviosas/metabolismo , Núcleo Hipotalámico Paraventricular/metabolismo , Fenoxibenzamina/farmacología , Neurohipófisis/metabolismo , Ratas , Núcleo Supraóptico/metabolismo , Privación de Agua , Equilibrio Hidroelectrolítico
8.
Science ; 365(6454): 692-694, 2019 08 16.
Artículo en Inglés | MEDLINE | ID: mdl-31416962

RESUMEN

Isotope compositions of basalts provide information about the chemical reservoirs in Earth's interior and play a critical role in defining models of Earth's structure. However, the helium isotope signature of the mantle below depths of a few hundred kilometers has been difficult to measure directly. This information is a vital baseline for understanding helium isotopes in erupted basalts. We measured He-Sr-Pb isotope ratios in superdeep diamond fluid inclusions from the transition zone (depth of 410 to 660 kilometers) unaffected by degassing and shallow crustal contamination. We found extreme He-C-Pb-Sr isotope variability, with high 3He/4He ratios related to higher helium concentrations. This indicates that a less degassed, high-3He/4He deep mantle source infiltrates the transition zone, where it interacts with recycled material, creating the diverse compositions recorded in ocean island basalts.

9.
J Clin Invest ; 58(3): 613-22, 1976 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-956390

RESUMEN

The possibility that lymphocytes from patients with rheumatoid arthritis (RA) might be sensitized to RA synovial cell antigens was investigated with a 51Cr release cytotoxicity assay. Peripheral blood lymphocytes from rheumatoid and normal donors were tested for cytotoxic activity against their own synovial cells and against allogeneic rheumatoid and nonrhemuatoid synovial cells. In the allogeneic studies, the degree of cytotoxicity was significantly influenced by the age in culture (passage number) of the synovial target cells (P less than 0.001). When the passage number of the target cells was considered in the analysis, rheumatoid lymphocytes were found to have greater cytotoxic activity than normal lymphocytes against young cultures (low passage number) of both RA and non-RA synovial cells (P = 0.0042). Differences in susceptibility to lysis between RA and non-RA synovial cells were more susceptible to both RA and normal lymphocyte-induced lysis than were non-RA synovial cells (P = 0.0048). No evidence of cytotoxicity was detected when lymphocytes from nine RA patients and two osteoarthritis patients were reacted against their own synovial cells. Although the data demonstrated an increased cytotoxic activity of peripheral blood lymphocytes from some RA patients against allogeneic synovial cells, the fact that this reactivity was seen against both non-RA and RA synovial cells and was not demonstrated against autologous synovial cells argues against the presence of an immunospecific response of RA lymphocytes to RA synovial cell antigens.


Asunto(s)
Artritis Reumatoide/sangre , Linfocitos/inmunología , Membrana Sinovial/patología , Adulto , Anciano , Reacciones Antígeno-Anticuerpo , Antígenos , Línea Celular , Radioisótopos de Cromo/metabolismo , Técnicas de Cultivo , Pruebas Inmunológicas de Citotoxicidad , Femenino , Fibroblastos/inmunología , Humanos , Inmunidad , Masculino , Persona de Mediana Edad , Membrana Sinovial/inmunología
10.
Curr Opin Neurobiol ; 6(3): 365-71, 1996 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-8794083

RESUMEN

From the secretion of neurotransmitters via synaptic vesicles to the expulsion of cellular waste via contractile vacuoles, exocytosis and its sequel, endocytosis, are being explored with a variety of new optical tools. Fluorescent markers, especially styryl dyes such as FM1-43 (which reversibly labels endosomal membranes), have been used to follow exo- and endocytic events in many cell types. Even though the development of new dyes is still largely empirical, some theoretical principles have emerged to guide future dye chemistry. Moreover, advances in optical imaging technology that augment conventional fluorescence microscopy are appearing. For example, interference reflection microscopy (which requires no flurophore) and total internal reflection microscopy have recently been used to observe single exocytic events at the contact point between a glass coverslip and the plasma membrane.


Asunto(s)
Endocitosis , Exocitosis , Óptica y Fotónica , Animales , Electrofisiología/métodos , Colorantes Fluorescentes , Compuestos de Piridinio , Compuestos de Amonio Cuaternario
11.
Arch Gen Psychiatry ; 41(12): 1144-8, 1984 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-6095785

RESUMEN

Specific binding of tritiated clonidine, an alpha 2-adrenergic receptor agonist, and tritiated yohimbine, an alpha 2-adrenergic receptor antagonist, to platelet membranes was measured in persons with panic attacks or major depression and in normal subjects. Plasma catecholamine levels were measured in patients with panic attacks and in normal subjects. The number of binding sites in patients with panic attacks, as measured with tritiated clonidine, was lower than in depressed persons and was the same as in normal subjects. The number in patients with panic attacks, as measured with tritiated yohimbine, was lower than in either depressives or normal subjects. Catecholamine levels were somewhat higher in patients with panic attacks than in normal subjects. Treatment with imipramine hydrochloride decreased the number of sites, as measured with either ligand, in both patient groups and increased catecholamine levels in patients with panic attacks.


Asunto(s)
Trastornos de Ansiedad/sangre , Plaquetas/metabolismo , Catecolaminas/sangre , Miedo , Pánico , Receptores Adrenérgicos alfa/metabolismo , Adolescente , Adulto , Trastornos de Ansiedad/tratamiento farmacológico , Trastornos de Ansiedad/metabolismo , Clonidina/metabolismo , Dopamina/sangre , Epinefrina/sangre , Miedo/efectos de los fármacos , Femenino , Humanos , Imipramina/farmacología , Imipramina/uso terapéutico , Masculino , Norepinefrina/sangre , Pánico/efectos de los fármacos , Ensayo de Unión Radioligante , Yohimbina/metabolismo
12.
Arch Gen Psychiatry ; 38(12): 1327-33, 1981 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-6274267

RESUMEN

The specific binding of tritiated (3H)-clonidine, an alpha 2-adrenergic receptor agonist, to platelet membranes was measured in normal subjects and in patients with major depressive disorder. The number of platelet alpha 2-adrenergic receptors from the depressed group was significantly higher than that found in platelets obtained from the control population. Treatment with tricyclic antidepressant drugs led to significant decreases in the number of platelet alpha 2-adrenergic receptors. These results support the hypothesis that the depressive syndrome is related to an alpha 2-adrenergic receptor supersensitivity and that the clinical effectiveness of tricyclic antidepressant drugs is associated with a decrease in the number of these receptors.


Asunto(s)
Plaquetas/metabolismo , Clonidina/metabolismo , Trastorno Depresivo/sangre , Receptores Adrenérgicos alfa/efectos de los fármacos , Receptores Adrenérgicos/efectos de los fármacos , Adolescente , Adulto , Anciano , Amitriptilina/farmacología , Trastorno Depresivo/tratamiento farmacológico , Femenino , Humanos , Hidrocortisona/sangre , Imipramina/farmacología , Masculino , Persona de Mediana Edad , Tritio
13.
J Clin Endocrinol Metab ; 63(4): 906-12, 1986 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-3018030

RESUMEN

Platelet adrenergic receptors were studied in normal subjects and diabetic patients with autonomic neuropathy to determine the relationship between adrenoreceptor status and orthostatic hypotension. The binding of [3H]clonidine and [3H]yohimbine to platelet membranes was measured in diabetic patients with autonomic neuropathy and orthostatic hypotension (n = 12) and without orthostatic hypotension (n = 11), diabetic patients without autonomic neuropathy (n = 12), and normal subjects (n = 9). Mean basal and standing plasma norepinephrine levels were not different in the four groups, and there was no relationship between orthostasis and norepinephrine responses. The diabetic patients with orthostatic hypotension had a significantly greater fall in mean blood pressure [31 +/- 2.8 (+/- SE) mm Hg] than any of the other three groups. Diabetic patients with diabetic autonomic neuropathy and orthostatic hypotension had a 30-40% decrease in number of platelet alpha 2-adrenergic receptors, as demonstrated by [3H]clonidine and [3H]yohimbine binding. The maximum number of binding sites for clonidine was 34 +/- 2.8 (+/- SE) fmol/mg protein in normal subjects, 27.4 +/- 3.4 in diabetic patients with neuropathy, 26 +/- 2.5 in diabetic patients with autonomic neuropathy without orthostatic hypotension, and 20.4 +/- 3.8 fmol/mg protein in diabetic patients with autonomic neuropathy with orthostatic hypotension (P less than 0.001). The maximum number of binding sites for yohimbine was 112 +/- 12.6 in normal subjects, 127 +/- 10 in diabetic patients without orthostatic hypotension, and 87 +/- 12.4 fmol/mg protein in patients with diabetic autonomic neuropathy with orthostatic hypotension (P less than 0.001). Reduced platelet alpha 2-receptors are associated with postural hypotension in diabetic autonomic neuropathy. If applicable to the postjunctional alpha 2-adrenergic receptor on sympathetic neurons, reduced vascular responses to changes in posture would be expected despite normal or enhanced norepinephrine secretion.


Asunto(s)
Enfermedades del Sistema Nervioso Autónomo/sangre , Plaquetas/metabolismo , Neuropatías Diabéticas/sangre , Hipotensión Ortostática/sangre , Receptores Adrenérgicos alfa/metabolismo , Adulto , Anciano , Catecolaminas/sangre , Clonidina/sangre , Femenino , Humanos , Masculino , Persona de Mediana Edad , Renina/sangre , Yohimbina/sangre
14.
Biol Psychiatry ; 20(5): 539-45, 1985 May.
Artículo en Inglés | MEDLINE | ID: mdl-2985130

RESUMEN

The specific binding to platelet membranes (Bmax) of 3H-clonidine, an alpha-2 agonist, and 3H-yohimbine, an alpha-2 antagonist, was measured in nine drug-free male schizophrenic patients and repeated after 2 weeks of chlorpromazine (CPZ) treatment. Patients with a lower pretreatment Bmax for 3H-clonidine showed a significantly smaller change in Bmax after treatment, less improvement in their clinical state, as indicated by the change in the Global Assessment Scale (GAS), and a lower posttreatment GAS. Also, they had a significantly higher score for negative symptoms on the Affect Rating Scale both before and after treatment. These findings suggest that schizophrenic patients with relatively subsensitive platelet alpha-2-adrenergic receptors, as measured by 3H-clonidine binding, tend to have more negative symptoms and a diminished alpha receptor binding response and diminished clinical response to CPZ. There were no clinical correlations to 3H-yohimbine binding.


Asunto(s)
Plaquetas/metabolismo , Clonidina/sangre , Receptores Adrenérgicos alfa/metabolismo , Esquizofrenia/sangre , Plaquetas/efectos de los fármacos , Clorpromazina/uso terapéutico , Humanos , Cinética , Escalas de Valoración Psiquiátrica , Receptores Adrenérgicos alfa/efectos de los fármacos , Esquizofrenia/tratamiento farmacológico , Psicología del Esquizofrénico , Yohimbina/sangre
15.
Biol Psychiatry ; 28(1): 3-20, 1990 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-2165422

RESUMEN

In order to evaluate adrenergic function in anxiety disorders, platelet alpha 2-adrenergic binding parameters and supine and standing blood pressure, pulse, and venous plasma epinephrine and norepinephrine were determined in patients with panic attacks or generalized anxiety disorder and in normal subjects. The maximum number of binding sites (Bmax) for the partial agonist tritiated clonidine was significantly lower for both patient groups than for normal subjects, and the Bmax for the antagonist tritiated yohimbine was significantly lower for panic patients. There were no other substantive differences across groups. Prior exposure to psychotropic drugs might account for the results for clonidine binding, but not for yohimbine. The Bmax for clonidine was correlated with norepinephrine increases upon standing and, for panic patients, with the severity of full unexpected panic attacks. These data provide further evidence of adrenergic receptor abnormalities in people with anxiety disorders.


Asunto(s)
Agorafobia/fisiopatología , Trastornos de Ansiedad/fisiopatología , Nivel de Alerta/fisiología , Plaquetas/metabolismo , Epinefrina/sangre , Miedo/fisiología , Norepinefrina/sangre , Pánico/fisiología , Receptores Adrenérgicos/fisiología , Adulto , Agorafobia/diagnóstico , Trastornos de Ansiedad/diagnóstico , Presión Sanguínea/fisiología , Clonidina/farmacocinética , Femenino , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Yohimbina/farmacocinética
16.
Biol Psychiatry ; 27(10): 1083-93, 1990 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-2160292

RESUMEN

Ten patients with obsessive-compulsive disorder (OCD) and 13 normal control subjects received intravenous infusions of 2 X 10(-6) g/kg of clonidine and normal saline on separate days. Responses to the drug relating to plasma growth hormone (GH), 3-methoxy-4-hydroxyphenylglycol (MHPG), heart rate, blood pressure, and several symptoms were determined. Additionally, platelet alpha 2-adrenoreceptor binding was measured in most of the subjects. GH, MHPG, blood pressure, and heart rate responses to clonidine did not differ between groups. As expected, patients reported more symptoms than normal subjects, and clonidine was sedating for both groups. Patients did not differ from normal subjects in the symptom response to clonidine. The maximum number of binding sites (Bmax) for tritiated clonidine was significantly greater in OCD patients than in normals. This pattern of alpha 2-adrenoreceptor status is different than the patterns in major depression and panic anxiety.


Asunto(s)
Plaquetas/metabolismo , Clonidina , Glicoles/sangre , Hormona del Crecimiento/sangre , Metoxihidroxifenilglicol/sangre , Trastorno Obsesivo Compulsivo/fisiopatología , Receptores Adrenérgicos/fisiología , Adulto , Nivel de Alerta/fisiología , Encéfalo/fisiopatología , Femenino , Humanos , Masculino , Trastorno Obsesivo Compulsivo/diagnóstico , Trastorno Obsesivo Compulsivo/psicología , Pruebas de Personalidad
17.
J Cereb Blood Flow Metab ; 13(6): 1006-12, 1993 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-8408308

RESUMEN

The quantitative autoradiographic L-[1-14C] leucine method for the determination of regional rates of cerebral protein synthesis (lCPSleu) requires knowledge of the degree of recycling of leucine derived from protein degradation into the precursor pool for protein synthesis, which can be evaluated by measuring lambda i, the steady-state ratio of the leucine-specific activity in the precursor amino acid pool (tRNA-bound leucine) to that of the arterial plasma. To define the changes in lCPSleu during regeneration of the hypoglossal nerve, we examined the effects of axotomy on the value of lambda i. Because the concentration of tRNA-bound leucine in the hypoglossal nucleus is too low to measure, we measured the equivalent ratio for the total acid-soluble pool (psi i) and applied the linear relationship between lambda and psi found in the whole brain to calculate a value of lambda i in the ipsilateral and contralateral hypoglossal nuclei of 22 adult female rats 2, 18, 35, and 60 days after unilateral hypoglossal axotomy. Statistically significant but quantitatively inconsequential effects of axotomy on values of psi i and lambda i were found. Therefore, the mean value for lambda i (0.64) of the left and right hypoglossal nuclei in all 22 axotomized rats was used to calculate lCPSleu. In a separate group of 15 unilaterally axotomized rats, lCPSleu was determined by the autoradiographic technique; lCPSleu was increased on the axotomized side by 23% on day 2, 30% on day 18, and 13% on day 35. By postaxotomy day 60, lCPSleu had returned to normal.


Asunto(s)
Axones/fisiología , Nervio Hipogloso/fisiología , Leucina/metabolismo , Proteínas del Tejido Nervioso/biosíntesis , Animales , Autorradiografía , Desnervación , Femenino , Nervio Hipogloso/cirugía , Cinética , Ratas , Ratas Sprague-Dawley
18.
J Cereb Blood Flow Metab ; 20(1): 192-200, 2000 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-10616808

RESUMEN

The relationship between local rates of cerebral glucose utilization (ICMRglc) and glucose transporter expression was examined during physiologic activation of the hypothalamoneurohypophysial system. Three days of water deprivation, which is known to activate the hypothalamoneurohypophysial system, resulted in increased ICMRglc and increased concentrations of GLUT1 and GLUT3 in the neurohypophysis; mRNA levels of GLUT1 and GLUT3 were decreased and increased, respectively. Water deprivation also increased ICMRglc in the hypothalamic supraoptic and paraventricular nuclei; mRNA levels of GLUT1 and GLUT3 appeared to increase in these nuclei, but the changes did not achieve statistical significance. Restoration of water for 3 to 7 days reversed all observed changes in GLUT expression (protein and mRNA): restoration of water also reversed changes in ICMRglc in both the neurohypophysis and the hypothalamic nuclei. These results indicate that under conditions of neural activation and recovery, changes in ICMRglc and the levels of GLUT1 and GLUT3 are temporally correlated in the neurohypophysis and raise the possibility that GLUT1 and GLUT3 transporter expression may be regulated by chronic changes in functional activity. In addition, increases in the expression of GLUT5 mRNA in the neurohypophysis after dehydration provide evidence for involvement of microglial activation.


Asunto(s)
Encéfalo/metabolismo , Ingestión de Líquidos/fisiología , Glucosa/metabolismo , Proteínas de Transporte de Monosacáridos/metabolismo , Proteínas del Tejido Nervioso , Privación de Agua/fisiología , Animales , Transportador de Glucosa de Tipo 1 , Transportador de Glucosa de Tipo 3 , Masculino , Proteínas de Transporte de Monosacáridos/genética , Núcleo Hipotalámico Paraventricular/metabolismo , Neurohipófisis/metabolismo , ARN Mensajero/metabolismo , Ratas , Ratas Sprague-Dawley , Núcleo Supraóptico/metabolismo
19.
Neurobiol Aging ; 15(5): 657-61, 1994.
Artículo en Inglés | MEDLINE | ID: mdl-7824059

RESUMEN

Beginning at 4 weeks of age normal, male, Sprague-Dawley rats were reared on Purina Laboratory Chow and drinking water containing 100 microM AlCl3. After 2 years, local rates of cerebral glucose utilization were determined with the autoradiographic [14C] deoxyglucose method in the brain as a whole and in 25 brain regions in 6 treated rats and 4 age-matched controls. The results indicate that any effects of chronic aluminum in the diet on rates of cerebral glucose utilization are small. In the brain as a whole, the mean rate of glucose utilization in the aluminum-treated rats was 6% lower than that of the controls (p = 0.09). In 21 of the 25 brain regions examined mean rates of glucose utilization were generally lower in the aluminum-treated rats but in none of the region were the effects statistically significant.


Asunto(s)
Envejecimiento/metabolismo , Aluminio/farmacología , Química Encefálica/efectos de los fármacos , Glucosa/metabolismo , Animales , Autorradiografía , Cromatografía de Gases , Desoxiglucosa/metabolismo , Dieta , Masculino , Ratas , Ratas Sprague-Dawley
20.
Am J Psychiatry ; 154(3): 349-54, 1997 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-9054782

RESUMEN

OBJECTIVE: This study examined the validity of four psychiatric utilization management criteria sets: the 1992 and 1993 InterQual Intensity, Severity, and Discharge (ISD) criteria, the Managed Care Appropriateness Protocol, and an instrument developed by the Department of Veterans Affairs (VA). METHOD: The appropriateness of acute care admission and continued stay for 70 randomly selected VA psychiatric inpatients was retrospectively assessed with each criteria set. The sensitivity and specificity of each instrument were evaluated by comparing its assessments to the consensus of judgments of a panel of expert psychiatrists who reviewed the same cases. Sensitivity was defined as the proportion of admissions or continued-stay days the panel found appropriate for acute care that the criteria judged to be appropriate for acute care; specificity was the proportion the panel found inappropriate for acute care that the criteria judged to be inappropriate for acute care. RESULTS: For admissions, there were only minor differences in the validity of the four criteria sets as assessed by agreement with the panel's judgments. For each of 4 continued-stay days studied, either the sensitivity or specificity of the 1993 InterQual ISD criteria was below 0.30. The specificity of the 1992 InterQual ISD criteria was below 0.60 for 2 days. In contrast, for the Managed Care Appropriateness Protocol, sensitivity was 0.73-0.93 and specificity was 0.78-0.88 over the 4 days. CONCLUSIONS: The findings raise major concerns about the validity of the widely used InterQual ISD psychiatry criteria, suggest that the Managed Care Appropriateness Protocol may be a useful tool for psychiatric utilization management, strongly underline the need to validate all criteria used to assess medical care, and support the appropriateness of the procedures used to perform these assessments.


Asunto(s)
Programas Controlados de Atención en Salud/normas , Trastornos Mentales/terapia , Garantía de la Calidad de Atención de Salud/normas , Revisión de Utilización de Recursos/estadística & datos numéricos , Adulto , Anciano , Femenino , Hospitalización/estadística & datos numéricos , Humanos , Masculino , Persona de Mediana Edad , Revisión por Expertos de la Atención de Salud , Distribución Aleatoria , Reproducibilidad de los Resultados , Estudios Retrospectivos
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