RESUMO
We describe a new method to broaden the frequency spectrum of a femtosecond oscillator in the continuous-wave (CW) domain. The method relies on modulating the femtosecond laser using four-wave mixing inside a Raman-based optical modulator. We prepare the modulator by placing deuterium molecules inside a high-finesse cavity and driving their fundamental vibrational transition using intense pump and Stokes lasers that are locked to the cavity modes. With the molecules prepared, any laser within the optical region of the spectrum can pass through the system and be modulated in a single pass. This constitutes a CW optical modulator at a frequency of 90 THz with a steady-state single-pass efficiency of â¼10-6 and transient (10 µs-time-scale) single-pass efficiency of â¼10-4. Using our modulator, we broaden the initial Ti:sapphire spectrum centered at 800 nm and produce upshifted and downshifted sidebands centered at wavelengths of 650 nm and 1.04 µm, respectively.
RESUMO
A multidisciplinary German expert group met in 2012 to discuss the current status and prospects of health care of geriatric patients with urinary incontinence in Germany. The purpose of this position paper is to raise awareness among health care providers for the challenges associated with adequate management of urinary incontinence in frail elderly. The experts agree that a multidisciplinary collaboration is essential for the successful treatment of urinary incontinence symptoms which are often associated with loss of autonomy and social isolation. For most geriatric patients, usually the general practitioner is the first contact when seeking help. Hence, the general practitioner plays a crucial role in the coordination of diagnosis and treatment. The involved health care providers should have adequate education and training in their respective disciplines and should be networked allowing quick turnaround times. Non-pharmacological treatments (e.g. behavioural interventions) should have been tried before any pharmacotherapy is initiated. If pharmacological treatment of urinary incontinence involves the use of anticholinergic agents, cognitive performance should be monitored regularly. If indicated, anticholinergic agents with a documented efficacy and safety profile, explicitly assessed in the elderly population, should be preferred.
Assuntos
Terapia Comportamental/métodos , Antagonistas Colinérgicos/uso terapêutico , Guias de Prática Clínica como Assunto , Melhoria de Qualidade/normas , Incontinência Urinária/diagnóstico , Incontinência Urinária/terapia , Urologia/normas , Idoso de 80 Anos ou mais , Feminino , Idoso Fragilizado , Avaliação Geriátrica/métodos , Alemanha , Humanos , MasculinoRESUMO
Despite limited evidence from clinical studies, anticoagulant drugs such as vitamin K antagonists (VKA) (e.g., warfarin or phenprocoumon) are widely used in the background treatment of patients with pulmonary arterial hypertension (PAH). According to current guidelines, they are generally accepted as efficacious drugs, although their efficacy is neither supported by randomised controlled trials, nor formally approved by regulatory agencies for use in the specific PAH indication. The use of these drugs is not without problems, as a paradoxical situation has to be managed in the treatment of this condition. On one hand, thrombosis is one of the key pathophysiologic features of PAH (besides vasoconstriction, proliferation and inflammation). On the other hand, the incidence of bleeding events is increased in PAH patients. This applies particularly to PAH that is related to connective tissue diseases, congenital heart disease and chronic thromboembolic pulmonary hypertension. In patients receiving VKA, caution must be observed in particular when concomitantly using prostanoids or sildenafil. Similarly, VKA doses have to be adjusted according to the labelling when using sitaxentan concomitantly. Regular International Normalized Ratio monitoring contributes to the safety of PAH patients on VKA.
Assuntos
Hemorragia/etiologia , Hipertensão Pulmonar/complicações , Anticoagulantes/efeitos adversos , Anticoagulantes/uso terapêutico , Anti-Hipertensivos/uso terapêutico , Antagonistas dos Receptores de Endotelina , Humanos , Hipertensão Pulmonar/tratamento farmacológico , Trombose/etiologia , Vitamina K/antagonistas & inibidoresRESUMO
The spontaneous natural killer (NK) and lymphokine-activated killer (LAK) cytotoxicity of highly purified CD56+CD3- NK cells (90 to 95%) against NK-sensitive and NK-insensitive target cells was drastically enhanced when a rhamnogalacturonan contained in a commercially available Viscum album extract was present during 4-h cytotoxicity assays. This enhancement correlated strictly with an increased formation of NK cell or LAK cell/tumor cell conjugate formation. Information on the chemical specificity of NK cell and LAK cell interaction with target cells and with the rhamnogalacturonan was obtained from inhibition studies. The most efficient inhibitors (100% inhibition at 5 mg/ml) were acetylated D-mannose and acetylated L-mannonic acid gamma-lactone. They specifically inhibited in a dose-dependent manner: (a) the cytotoxicity of NK cells against K562 cells and the formation of NK cell/K562 cell conjugates; (b) the cytotoxicity of LAK cells against K562 cells and Daudi cells as well as the formation of LAK cell/K562 cell and of LAK cell/Daudi cell conjugates; and (c) the synergistic effects of the rhamnogalacturonan in the cytotoxicity assays and the target cell-conjugate formation assays with NK cells and LAK cells. The inhibitory effects observed after pretreatment of NK cells or LAK cells with acetylated mannose were completely reversible, but that obtained with acetylated mannonic acid gamma-lactone was only partly reversible, and the degree of reversibility depended on the inhibitor concentration applied during pretreatment. Nonacetylated mannose or mannose derivatives up to concentrations of 20 mmol showed no inhibitory effects. A mechanistic model representing the interaction of NK cells and LAK cells with target cells and with rhamnogalacturonan is proposed.
Assuntos
Galactanos/farmacologia , Células Matadoras Naturais/imunologia , Polissacarídeos/farmacologia , Antígenos de Diferenciação de Linfócitos T/imunologia , Complexo CD3 , Antígeno CD56 , Humanos , Interleucina-2/imunologia , Interleucina-2/farmacologia , Células Matadoras Ativadas por Linfocina/efeitos dos fármacos , Células Matadoras Ativadas por Linfocina/imunologia , Células Matadoras Naturais/efeitos dos fármacos , Receptores de Antígenos de Linfócitos T/imunologiaRESUMO
To examine the "serotonin hypothesis" of obsessive-compulsive disorder (OCD), we studied the behavioral and neuroendocrine effects of metachlorophenylpiperazine (mCPP), a serotonergic agonist, in patients with OCD and healthy controls. Twelve patients and 20 controls were given a single dose of 0.5 mg/kg of mCPP, administered orally under double-blind, placebo-controlled, random-assignment conditions. Following mCPP, but not following placebo, patients with OCD experienced a transient but marked exacerbation of obsessive-compulsive symptoms. Moreover, compared with healthy controls, patients exhibited greater other behavioral (but not endocrinologic or thermal) changes after mCPP. These findings are consistent with a special role for the neurotransmitter serotonin in OCD psychopathology.
Assuntos
Transtorno Obsessivo-Compulsivo/metabolismo , Piperazinas/farmacologia , Serotonina/metabolismo , Adulto , Afeto/efeitos dos fármacos , Idoso , Comportamento/efeitos dos fármacos , Temperatura Corporal/efeitos dos fármacos , Feminino , Humanos , Masculino , Metergolina/farmacologia , Pessoa de Meia-Idade , Transtorno Obsessivo-Compulsivo/sangue , Transtorno Obsessivo-Compulsivo/psicologia , Piperazinas/sangue , Prolactina/sangue , Antagonistas da Serotonina/farmacologiaRESUMO
We compared the cognitive and behavioral responses to three intravenous doses of scopolamine (0.1, 0.25, and 0.5 mg) and placebo of ten patients with dementia of the Alzheimer type (DAT) and ten age- and sex-matched elderly control subjects. The patients with DAT showed significant behavioral and cognitive but not physiologic changes at a lower scopolamine dose (0.25 mg) than did the normal elderly controls. Cognitive tests of new learning and semantic knowledge revealed significant impairments at the 0.25-mg scopolamine dose in the patients with DAT, while the responses of the control population were essentially unchanged. Behaviorally, mild euphoria, motor incoordination, and hostility occurred in the patients with DAT but not the controls at the 0.25-mg dose. These differences were unrelated to peripheral physiologic changes produced by the different scopolamine doses. These results indicate that central nervous system functions such as cognition and certain elements of behavior are more sensitive to temporary cholinergic blockade in patients with DAT than in normal age-matched controls. We review implications concerning the status of central cholinergic function in patients with DAT in light of neuropathologically demonstrated cholinergic system lesions in DAT.
Assuntos
Doença de Alzheimer/fisiopatologia , Sistema Nervoso Parassimpático/fisiopatologia , Escopolamina/farmacologia , Fatores Etários , Doença de Alzheimer/psicologia , Pressão Sanguínea/efeitos dos fármacos , Cognição/efeitos dos fármacos , Relação Dose-Resposta a Droga , Feminino , Frequência Cardíaca/efeitos dos fármacos , Humanos , Masculino , Memória/efeitos dos fármacos , Pessoa de Meia-Idade , Sistema Nervoso Parassimpático/efeitos dos fármacos , Escalas de Graduação Psiquiátrica , Testes Psicológicos , Desempenho Psicomotor/efeitos dos fármacosRESUMO
Preclinical and clinical evidence supports a theory of serotonin (5-hydroxytryptamine [5-HT]) dysregulation in bulimia. We therefore studied the prolactin (PRL) and cortisol responses following challenges with the postsynaptic 5-HT receptor agonist m-chlorophenylpiperazine (m-CPP), 0.5 mg/kg orally, the 5-HT precursor L-tryptophan, 100 mg/kg intravenously, and placebo in a group of 28 normal weight bulimic patients and 16 healthy controls. Patients with bulimia, regardless of the presence of major depression, had significantly blunted PRL responses following m-CPP administration compared with those in controls. In contrast, only bulimic patients with concurrent major depression had significantly blunted PRL responses following L-tryptophan administration compared with those in nondepressed bulimic patients and controls. Cortisol responses following m-CPP were not significantly different for bulimic patients vs controls, although there was a trend toward blunted cortisol responses following L-tryptophan administration in the depressed bulimic patients. These differences in neuroendocrine responses were not related to differences in age, percent of average body weight, medications, time of day, peak plasma drug levels, or baseline estradiol levels. Seasonal variations in PRL responses to both agents were identified, although covariation for season did not alter the group differences. The PRL responses following m-CPP administration were inversely correlated to baseline cortisol levels in the bulimic patients, but not in the controls, suggesting a dampening effect by hypothalamic-pituitary-adrenal axis dysfunction on postsynaptic 5-HT receptor sensitivity. The reasons for the differing hormonal responses to these two serotonergic agents may relate to differential involvement of presynaptic and postsynaptic mechanisms, 5-HT receptor subtypes, and anatomical loci of action. The blunted PRL responses to m-CPP administration suggest that postsynaptic 5-HT receptor sensitivity is altered in bulimia nervosa, and that similar alterations in 5-HT receptors at or above the level of the hypothalamus may contribute to binge eating and other behavioral symptoms.
Assuntos
Bulimia/diagnóstico , Hidrocortisona/sangue , Piperazinas , Prolactina/sangue , Triptofano , Adulto , Fatores Etários , Peso Corporal , Bulimia/complicações , Bulimia/fisiopatologia , Ritmo Circadiano , Transtorno Depressivo/sangue , Transtorno Depressivo/complicações , Transtorno Depressivo/diagnóstico , Diagnóstico Diferencial , Estradiol/sangue , Humanos , Piperazinas/farmacologia , Placebos , Receptores de Serotonina/efeitos dos fármacos , Receptores de Serotonina/fisiologia , Estações do Ano , Serotonina/fisiologia , Triptofano/farmacologiaRESUMO
Since monoamine neurotransmitter disturbances exist in some cases of dementia of the Alzheimer's type (DAT), monoamine-enhancing drugs may ameliorate some symptoms of DAT. L-Deprenyl is a monoamine oxidase (MAO) inhibitor that is generally free of undesired effects. At low doses (10 mg/d) it selectively inhibits MAO-B, an enzyme whose level is elevated in the brains of patients with DAT who are studied post mortem. At higher doses it has more complex effects, including inhibition of MAO-A plus MAO-B. We administered 10 mg/d and 40 mg/d of L-deprenyl to 17 patients with DAT in a double-blind, placebo-controlled, serial treatment. Total Brief Psychiatric Rating Scale scores decreased significantly during 10-mg/d treatment, with decreases in measures of anxiety/depression, tension, and excitement. Approximately one half of the patients' conditions were judged to be improved clinically, with evidence of increased activity and social interaction along with reduced tension and retardation. Similar but smaller changes were observed during 40-mg/d treatment. The behavioral changes were associated with improvement in performance on a complex cognitive task requiring sustained effort. There were minimal physiologic and side effects. The greater effect of low-dose L-deprenyl therapy suggests that it is the inhibition of MAO-B, and not MAO-A, that may be important in the behavioral effects of L-deprenyl administration to patients with DAT.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Fenetilaminas/uso terapêutico , Selegilina/uso terapêutico , Adulto , Idoso , Doença de Alzheimer/psicologia , Pressão Sanguínea/efeitos dos fármacos , Ensaios Clínicos como Assunto , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inibidores da Monoaminoxidase , Placebos , Escalas de Graduação Psiquiátrica , Pulso Arterial/efeitos dos fármacos , Selegilina/administração & dosagem , Selegilina/farmacologiaRESUMO
BACKGROUND: We examined the effect of high-dose selegiline in 16 treatment-resistant older depressive patients. We hypothesized that selegiline, at a dosage of 60 mg/d, would be at least partially effective but that the higher doses would not maintain the monoamine oxidase B selectivity observed with the lower doses of selegiline. METHODS: Sixteen treatment-resistant subjects (mean [+/- SD] age, 65.6 +/- 9.3 years) entered a double-blind, randomized, crossover study of placebo vs 3 weeks of selegiline at a dosage of 60 mg/d. Objective measures of mood and behavior were obtained in all subjects, and 10 of the subjects underwent repeated lumbar punctures for analysis of monoamine metabolites in the cerebrospinal fluid. RESULTS: Objective measures of mood and behavior revealed significant improvement in the Hamilton Depression Rating Scale score (37.4% decrease), the Global Depression score (22.7% decrease), and the Brief Psychiatric Rating Scale score (19.3% decrease); subjective behavioral measures, however, did not show significant improvement during the 3-week medication trial. Cerebrospinal fluid values revealed a statistically significant drop in 3-methoxy-4-hydroxyphenylglycol (51%) and 5-hydroxyindoleacetic acid (17%) levels, and there was a significant lowering of systolic blood pressure on standing (15%), but these changes were not accompanied by clinical side effects. CONCLUSIONS: Our results suggest that high-dose selegiline can be an effective antidepressant in treatment-resistant older depressive patients. While the selegiline dose required has nonselective monoamine oxidase effects and thus would not be free of possible tyramine interactions, other advantages suggest that further investigations with selegiline are warranted in this population.
Assuntos
Transtorno Depressivo/tratamento farmacológico , Selegilina/administração & dosagem , Fatores Etários , Idoso , Pressão Sanguínea/efeitos dos fármacos , Transtorno Depressivo/líquido cefalorraquidiano , Transtorno Depressivo/psicologia , Relação Dose-Resposta a Droga , Método Duplo-Cego , Esquema de Medicação , Feminino , Humanos , Ácido Hidroxi-Indolacético/líquido cefalorraquidiano , Hipotensão Ortostática/induzido quimicamente , Masculino , Metoxi-Hidroxifenilglicol/líquido cefalorraquidiano , Pessoa de Meia-Idade , Placebos , Escalas de Graduação Psiquiátrica , Selegilina/uso terapêutico , Resultado do TratamentoRESUMO
M-Chlorophenylpiperazine (m-CPP) produces effects on the central serotonergic system in animals compatible with direct agonist activity on postsynaptic serotonin receptors. Although it is a metabolite of the antidepressant trazodone, m-CPP has not previously been given to humans. To evaluate the neuroendocrine, behavioral, and physiological effects of m-CPP, 15 normal subjects were given 0.5 mg/kg m-CPP, orally. Administered acutely under double blind, placebo-controlled conditions, m-CPP was well tolerated by 14 of the 15 subjects; it produced significant increases in plasma PRL and cortisol and in body temperature, without changing pulse or blood pressure. The mean (SD) maximal increases over baseline for PRL, cortisol and temperature were 13.4 (9.9) ng/ml, 10.1 (6.7) micrograms/100 ml, and 0.4 (0.2) C, respectively. A small but significant increase in self-rated activation-euphoria and anxiety was noted by some subjects, whereas there were no significant effects on ratings of depression, dysphoria, altered self-reality, or functional impairment. These results are similar to those for other serotonin agonists and, thus, suggest that m-CPP merits further study as a pharmacological probe of serotonergic responsivity in humans. The results also support the hypothesis that serotonin plays a role in the regulation of PRL, cortisol, body temperature, and mood.
Assuntos
Comportamento/efeitos dos fármacos , Sistemas Neurossecretores/efeitos dos fármacos , Piperazinas/farmacologia , Receptores de Serotonina/efeitos dos fármacos , Adulto , Idoso , Pressão Sanguínea/efeitos dos fármacos , Temperatura Corporal/efeitos dos fármacos , Feminino , Humanos , Hidrocortisona/sangue , Masculino , Pessoa de Meia-Idade , Prolactina/sangue , Pulso Arterial/efeitos dos fármacosRESUMO
Reports of the antiobsessional efficacy of clomipramine have led to a "serotonin hypothesis" of obsessive-compulsive disorder (OCD). To test this hypothesis, 16 outpatients with DSM-III OCD were studied using several measures of serotonergic function. Platelet 3H-imipramine binding and serotonin uptake were not significantly different between the OCD patients and a normal, age-matched control group. The level of the metabolite 5-hydroxyindoleacetic acid (5-HIAA) in cerebrospinal fluid (CSF) was significantly higher in a small cohort of obsessionals compared with healthy volunteers, possibly reflecting increased brain serotonin turnover. In a direct test of the role of serotonin uptake in clomipramine's antiobsessional effects, the serotonin uptake inhibitor zimelidine was compared with the noradrenergic uptake inhibitor desipramine in a double-blind, controlled study. Zimelidine reduced CSF 5-HIAA, but was clinically ineffective in this group. Desipramine had weak but significant clinical effects. Nonresponders to zimelidine or desipramine improved significantly during a subsequent double blind trial of clomipramine. These findings demonstrate that pharmacological blockade of serotonin reuptake alone is not sufficient for an antiobsessional response.
Assuntos
Sistema Nervoso Central/metabolismo , Desipramina/uso terapêutico , Transtorno Obsessivo-Compulsivo/metabolismo , Serotonina/metabolismo , Zimeldina/uso terapêutico , Adulto , Plaquetas/metabolismo , Ensaios Clínicos como Assunto , Feminino , Humanos , Ácido Hidroxi-Indolacético/líquido cefalorraquidiano , Masculino , Transtorno Obsessivo-Compulsivo/tratamento farmacológicoRESUMO
The behavioral effects of a 2 mg/kg iv bolus infusion of naloxone were compared with a placebo infusion using a double-blind design in a small group of inpatient depressives (n = 6) and normals (n = 8). Naloxone produced consistent and significant worsening in the rated signs and subjective symptoms of depression in the patients. In the normals, lesser changes in Hamilton depression and BPRS total scores were observed while none of the subjective scales were significantly altered. The data suggest that depressives manifest a more marked and subjectively more intense response to naloxone compared to normals. Further studies are required to confirm this preliminary finding and to clarify its relationship to the pathogenesis of depression.
Assuntos
Transtorno Depressivo/tratamento farmacológico , Naloxona/uso terapêutico , Adulto , Transtorno Bipolar/tratamento farmacológico , Transtorno Bipolar/psicologia , Transtorno Depressivo/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Escalas de Graduação PsiquiátricaRESUMO
Six patients (mean age 62.5 +/- 7.6 years) with major depression were treated for 2 weeks with the serotonin agonist m-chlorophenylpiperazine (m-CPP), 80 mg/day in a double-blind, placebo-controlled, crossover-design pilot study. Two patients showed clinically significant improvement in depressive symptoms during active drug treatment, whereas two others showed modest effects. All patients tolerated the drug, with no major side effects and no changes in vital signs or in liver, renal, thyroid, or hematological function. Further studies are needed to determine the characteristics of the possible antidepressant effects of m-CPP; such work may yield greater understanding of the role of serotonin in affective and other psychiatric disorders.
Assuntos
Antidepressivos/uso terapêutico , Transtorno Depressivo/tratamento farmacológico , Piperazinas/uso terapêutico , Idoso , Encéfalo/efeitos dos fármacos , Transtorno Depressivo/psicologia , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Escalas de Graduação Psiquiátrica , Receptores de Serotonina/efeitos dos fármacosRESUMO
In a study of serotonin (5-HT) function in patients with eating disorders and healthy control subjects, severe headaches with features of common migraine occurred unexpectedly in 28 of 52 subjects (54%) 8 to 12 hours after receiving a single oral dose of the 5-HT receptor agonist m-chlorophenylpiperazine (m-CPP), 0.5 mg/kg. None of the same subjects developed similar late-occurring headaches after placebo or the 5-HT precursor, L-tryptophan, 100 mg/kg given intravenously. The frequency of these migrainelike headaches was not significantly different between patients with bulimia or anorexia nervosa and control subjects, but incidence of headaches was significantly greater in subjects with a personal or family history of migraine, with almost all predisposed individuals (18 of 20, 90%) developing severe symptoms. Headache ratings were also significantly correlated (rho = 0.70; p less than 0.0001) with peak concentrations of m-CPP in plasma. These observations indicate that m-CPP may provide a novel probe for studies of the pathophysiology of migraine headaches.
Assuntos
Transtornos de Enxaqueca/induzido quimicamente , Piperazinas/farmacologia , Receptores de Serotonina/efeitos dos fármacos , Adulto , Feminino , Humanos , Transtornos de Enxaqueca/etiologia , Piperazinas/sangueRESUMO
Somatostatin-like immunoreactivity was measured in the CSF of 12 patients with Alzheimer's disease, 15 age-matched control subjects, and 20 older depressed subjects. Patients with dementia or depression were found to have lower CSF somatostatin concentrations than control subjects despite markedly different clinical presentations. Severity of depression was clearly different in all three groups but showed no significant correlation with CSF concentration of somatostatin. There was a significant positive correlation between CSF somatostatin-like immunoreactivity and cognitive functioning in all 47 subjects, but this association was not statistically significant within individual diagnostic groups. These data raise interesting questions about possible biological links between Alzheimer's disease and depression in older patients.
Assuntos
Doença de Alzheimer/líquido cefalorraquidiano , Transtorno Depressivo/líquido cefalorraquidiano , Somatostatina/líquido cefalorraquidiano , Fatores Etários , Doença de Alzheimer/psicologia , Transtorno Depressivo/psicologia , Feminino , Humanos , Masculino , Memória , Pessoa de Meia-Idade , Peptídeos/líquido cefalorraquidiano , Escalas de Graduação Psiquiátrica , Fatores Sexuais , Escalas de WechslerRESUMO
Twenty-one subjects with clinically diagnosed dementia of the Alzheimer type were rated on the Dementia Mood Assessment Scale, a new instrument intended to measure the severity of depressed mood in cognitively impaired patients. Ratings were based on direct observation and a semistructured interview of the patient. Interrater reliability was established. There were highly significant correlations between patients' scores on the instrument's 17-item depression subscale and their scores on global measures of depression and sadness. The potential usefulness of this new scale in assessing the severity of depression in demented patients longitudinally or under drug treatment conditions is discussed.
Assuntos
Doença de Alzheimer/complicações , Depressão/diagnóstico , Escalas de Graduação Psiquiátrica , Adulto , Idoso , Depressão/complicações , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , PsicometriaRESUMO
OBJECTIVE: To determine which brain regions lose volume with aging over time in healthy, nondemented elderly. BACKGROUND: Cross-sectional studies suggest widespread loss of brain volume with aging. These studies may be biased by significant numbers of preclinically demented elderly in the oldest comparison groups. Longitudinal studies may allow closer determination of the effect of aging unaffected by dementia. METHODS: Quantitative volumetric MRI was performed annually on 46 healthy subjects older than age 65 who had maintained cognitive health a mean of 5 years. Comparisons (analysis of variance) were made of rates of volume loss (slopes) divided into 11 young-old (mean age, 70 years), 15 middle-old (mean age, 81 years), and 20 oldest-old (mean age, 87 years) subjects. Regions of interest included CSF spaces, lobar regions, and limbic-subcortical regions. RESULTS: There were significant differences between groups in intracranial, total brain, left hemisphere, right hemisphere, temporal lobe, basilar-subcortical region, and hippocampus volumes, with oldest-old subjects showing the smallest volumes, followed by middle-old and young-old subjects. Oldest-old subjects had significantly greater subarachnoid volumes than the younger groups. There were no significant differences in rates of change of regions of interest across age groups. CONCLUSIONS: After age 65 there is minimal brain volume loss observed over time in healthy elderly. Brain volume differences seen cross-sectionally, at any age, likely reflect small, constant rates of volume loss with healthy aging. Healthy oldest-old subjects do not show greater rates of brain loss compared with younger elderly, suggesting that large changes seen in cross-sectional studies reflect the presence of preclinical dementia in older groups.
Assuntos
Envelhecimento/patologia , Encéfalo/patologia , Idoso , Idoso de 80 Anos ou mais , Atrofia , Feminino , Humanos , Masculino , Entrevista Psiquiátrica Padronizada , Testes Neuropsicológicos , Tamanho do ÓrgãoRESUMO
The isolation from human peripheral blood lymphocytes of natural killer (NK) cell populations by a novel magnetic cell sorting (MACS) procedure yielded large amounts of viable cells with active cytotoxic function. Non-adherent B cell-depleted lymphocytes were sequentially labelled with specific monoclonal antibodies, biotin-conjugated second antibody, FITC-conjugated streptavidin and biotin-conjugated magnetic particles (diameter 50-150 nm). In the magnetic field of a permanent magnet, positively labelled cells were retained on columns with a ferromagnetic matrix. When OKT3 was used for the depletion, 96-99% of the T cells were removed. The resulting non-labelled NK cell population contained 78-89% Leu11b+ and 87-96% Leu19+ cells. Magnetic retention of NK cells mediated by anti-Leu19 yielded about 81% and retention mediated by anti-Leu11b about 80% of total cells as determined by positive fluorescence. The resulting labelled and unlabelled cell subpopulations maintained their full NK activity as determined in 4 h cytotoxicity assays against human K562 tumor cells. The viability of non-labelled cells was fully preserved, whereas that of labelled cells slowly decreased with increasing numbers of preparative cycles. Furthermore, the ability of the isolated NK cells to show enhancement of their NK cytotoxicity after preincubation with IL-2 was maintained. The cytotoxic function of NK cells was also preserved when two or more MACS cycles using the same or different antibodies were carried out. The saving of time and the physiological condition of the isolated cells offer valuable advantages over FACS procedures.
Assuntos
Separação Celular/métodos , Células Matadoras Naturais/fisiologia , Anticorpos Monoclonais , Citotoxicidade Imunológica , Humanos , Interleucina-2/fisiologia , MagnetismoRESUMO
The steady-state pharmacokinetics and tolerability of a microemulsion formulation of cyclosporine (Sandimmune Neoral) were compared with Sandimmune in 18 clinically stable renal allograft recipients. In study period I (2 weeks duration), patients entered the study on a stable, individualized twice-daily dosage regimen of Sandimmune. Two approaches were assessed for changing patients over from Sandimmune to Sandimmune Neoral. In period II (2 weeks), doses were converted based on the area under the curve ratio derived from a relative bioavailability study comparing the two formulations in healthy volunteers. In period III (2 weeks), doses were titrated to provide comparable steady-state trough concentrations as at study entry. Sandimmune was reinstituted during period IV (2 weeks). Safety and tolerability were assessed at weekly clinic visits and the steady-state pharmacokinetics of cyclosporine in whole blood were characterized at the end of each study period. Dose conversion in period II based on the AUC ratio derived from healthy volunteers was inadequate for achieving comparable cyclosporine exposure as assessed by steady-state AUC and troughs. The concentration-controlled approach (period III) indicated that maintaining the same cyclosporine dose when changing between formulations yields comparable steady-state trough concentrations. Concomitant with this conversion, steady-state peak concentration and AUC increased on average by 39% and 15%, respectively, due to absorption-related differences between the formulations. These increases were not associated with adverse events or changes in blood pressure or clinical laboratory parameters. Furthermore, they were not detrimental to the transplanted kidney as monitored by ultrasound examination. The pharmacokinetic profiles from Sandimmune Neoral exhibited less variability and yielded a stronger correlation between trough concentration and systemic exposure (AUC) compared with Sandimmune.
Assuntos
Ciclosporina/administração & dosagem , Ciclosporina/farmacocinética , Transplante de Rim/fisiologia , Administração Oral , Adulto , Idoso , Cápsulas , Química Farmacêutica , Tolerância a Medicamentos , Emulsões , Feminino , Humanos , Masculino , Microquímica , Pessoa de Meia-IdadeRESUMO
A microemulsion formulation of CsA, which was anticipated to be independent of bile for oral absorption, was compared with the currently marketed formulation in liver transplant patients with external biliary drainage. Eleven patients aged 47.6 +/- 13.1 years and weighing 75.8 +/- 5.7 kg received single 400-mg oral doses of each formulation in a randomized, crossover protocol on days 4 and 6 after transplant. Serial venous blood samples were collected over a 12-hr period after each administration and whole blood CsA concentrations were determined by a validated RIA specific for the parent compound. Systemic exposure to CsA was consistently higher from the microemulsion formulation in all patients, as judged by the peak concentration and the area under the curve. Specifically, the area under the concentration-time curve was 943 +/- 400 vs. 2378 +/- 911 ng.hr/ml, indicating an average 156% higher bioavailability from the microemulsion compared with the currently marketed formulation in liver transplant patients in the absence of bile.