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1.
HIV Med ; 13(7): 387-97, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22257025

RESUMO

OBJECTIVES: Smoking is the most prevalent modifiable risk factor for cardiovascular diseases among HIV-positive persons. We assessed the effect on smoking cessation of training HIV care physicians in counselling. METHODS: The Swiss HIV Cohort Study (SHCS) is a multicentre prospective observational database. Our single-centre intervention at the Zurich centre included a half day of standardized training for physicians in counselling and in the pharmacotherapy of smokers, and a physicians' checklist for semi-annual documentation of their counselling. Smoking status was then compared between participants at the Zurich centre and other institutions. We used marginal logistic regression models with exchangeable correlation structure and robust standard errors to estimate the odds of smoking cessation and relapse. RESULTS: Between April 2000 and December 2010, 11 056 SHCS participants had 121 238 semi-annual visits and 64 118 person-years of follow-up. The prevalence of smoking decreased from 60 to 43%. During the intervention at the Zurich centre from November 2007 to December 2009, 1689 participants in this centre had 6068 cohort visits. These participants were more likely to stop smoking [odds ratio (OR) 1.23; 95% confidence interval (CI) 1.07-1.42; P=0.004] and had fewer relapses (OR 0.75; 95% CI 0.61-0.92; P=0.007) than participants at other SHCS institutions. The effect of the intervention was stronger than the calendar time effect (OR 1.19 vs. 1.04 per year, respectively). Middle-aged participants, injecting drug users, and participants with psychiatric problems or with higher alcohol consumption were less likely to stop smoking, whereas persons with a prior cardiovascular event were more likely to stop smoking. CONCLUSIONS: An institution-wide training programme for HIV care physicians in smoking cessation counselling led to increased smoking cessation and fewer relapses.


Assuntos
Aconselhamento Diretivo/métodos , Soropositividade para HIV/complicações , Capacitação em Serviço , Médicos/normas , Abandono do Hábito de Fumar/métodos , Fumar/terapia , Adulto , Fatores Etários , Idoso , Estudos de Coortes , Feminino , Humanos , Modelos Logísticos , Masculino , Transtornos Mentais/complicações , Pessoa de Meia-Idade , Motivação , Razão de Chances , Relações Médico-Paciente , Médicos/tendências , Estudos Prospectivos , Fatores de Risco , Fumar/efeitos adversos , Transtornos Relacionados ao Uso de Substâncias/complicações , Suíça/epidemiologia
2.
Geburtshilfe Frauenheilkd ; 77(1): 73-80, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28190892

RESUMO

Introduction The corpus luteum (CL) is dependent on luteal vascular permeability, which is controlled by human chorionic gonadotropin (hCG) via vascular endothelial growth factor (VEGF). In this study we investigated the role of a potential VEGF antagonist pathway - Slit2/Robo4 - and its influence on endothelial cell adhesion. Materials and Methods Luteinized granulosa cells (LGCs) were stimulated with hCG in the absence or presence of a VEGF inhibitor. The expression of VEGF and Slit2 were measured. Human umbilical vein endothelial cells (HUVECs) were stimulated with Slit2 or VEGF, and gene expressions of cadherin 5 (CDH5) and claudin 5 (CLDN5) were measured. Following Robo4 knockdown, CDH5, CLDN5 and endothelial permeability were measured. Results Stimulation of human LGCs with hCG significantly increased VEGF while Slit2 expression was significantly suppressed. Inhibition of VEGF action after hCG stimulation did not change Slit2 suppression. Slit2 knockdown did not affect VEGF expression. While VEGF stimulation of HUVECs significantly suppressed CDH5 and CLDN5 gene expression, stimulation of HUVECs with Slit2 resulted in a significant increase in CDH5 and CLDN5. Robo4 knockdown was done, leading to downregulation of CDH5 and CLDN5 which resulted in significantly increased permeability. Conclusions Our results indicate the existence of a VEGF-antagonist pathway in the CL that decreases vascular permeability. During the functional life of the CL the pathway is suppressed by hCG. It is possible that stimulation of this pathway could be used to treat ovarian hyperstimulation syndrome.

3.
Clin Pharmacol Ther ; 49(3): 248-55, 1991 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-2007319

RESUMO

During this open, two-period crossover study in eight healthy volunteers, 1200 mg anhydrous theophylline was administered as a two-stage infusion during 24 hours on day 6. During one of the 8-day periods, 300 mg caffeine, t.i.d., was administered orally. After the start of the theophylline infusion, plasma concentrations of theophylline and caffeine and urinary excretion of theophylline and four metabolites were determined frequently during 60 hours. With caffeine administration theophylline steady-state concentration and area under the curve increased by 23% and 40%, respectively, whereas the volume of distribution at steady state seemed unchanged. The cumulative urinary excretion of 1-methyluric acid and 1-methylxanthine did not reach a plateau, suggesting a capacity-limiting factor in their formation. Notwithstanding the mutual interference of theophylline and caffeine metabolism, the reduction in apparent total body clearance and elimination rate constant of theophylline by 29% and 31%, respectively, indicated a pronounced influence of concomitant administration of realistic amounts of caffeine.


Assuntos
Cafeína/farmacologia , Teofilina/farmacocinética , Administração Oral , Adulto , Cafeína/administração & dosagem , Cafeína/sangue , Cafeína/urina , Esquema de Medicação , Humanos , Infusões Intravenosas , Masculino , Teofilina/administração & dosagem , Teofilina/sangue , Teofilina/urina
4.
J Med Chem ; 41(26): 5219-46, 1998 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-9857091

RESUMO

The structure-activity relationships in two series of hypoglycemic benzoic acid derivatives (5, 6) were investigated. Series 5 resulted from meglitinide (3) when the 2-methoxy was replaced by an alkyleneimino residue. Maximum activity was observed with the cis-3, 5-dimethyl-piperidino (5h) and the octamethyleneimino (5l) residues. Series 6 resulted from the meglitinide analogon 4 bearing an inversed amido function when the 2-methoxy, the 5-fluoro, and the alpha-methyl residue were replaced by a 2-piperidino, a 5-hydrogen, and a larger alpha-alkyl residue, respectively. An alkoxy residue ortho to the carboxy group further increased activity and duration of action in the rat. The most active racemic compound, 6al (R4 = isobutyl; R = ethoxy), turned out to be 12 times more active than the sulfonylurea (SU) glibenclamide (1). Activity was found to reside predominantly in the (S)-enantiomers. Compared with the SUs 1 and 2 (glimepiride), the most active enantiomer, (S)-6al (AG-EE 623 ZW; repaglinide; ED50 = 10 micro/kg po), is 25 and 18 times more active. Repaglinide turned out to be a useful therapeutic for type 2 diabetic patients; approval was granted recently by the FDA and the EMEA. From investigations on the pharmacophoric groups in compounds of type 5 and 6, it was concluded that in addition to the two already known-the acidic group (COOH; SO2NH) and the amidic spacer (CONH; NHCO)-the ortho residue R1 (alkyleneimino; alkoxy; oxo) must be regarded as a third one. A general pharmacophore model suitable for hypoglycemic benzoic acid derivatives, SUs, and sulfonamides is proposed (Figure 6). Furthermore, from superpositions of low-energy conformations (LECs) of 1, 2, and (S)-6al, it was concluded that a common binding conformation (LEC II; Figure 10B) may exist and that differences in binding to the SU receptor and in the mechanism of insulin release between repaglinide and the two SUs may be due to specific hydrophobic differences.


Assuntos
Transportadores de Cassetes de Ligação de ATP , Benzoatos/farmacologia , Carbamatos/farmacologia , Hipoglicemiantes/farmacologia , Piperidinas/farmacologia , Canais de Potássio Corretores do Fluxo de Internalização , Administração Oral , Animais , Benzoatos/síntese química , Benzoatos/química , Benzoatos/metabolismo , Glicemia/metabolismo , Carbamatos/síntese química , Carbamatos/química , Carbamatos/metabolismo , Cristalografia por Raios X , Feminino , Glibureto/química , Glibureto/metabolismo , Glibureto/farmacologia , Hipoglicemiantes/síntese química , Hipoglicemiantes/química , Hipoglicemiantes/metabolismo , Modelos Moleculares , Conformação Molecular , Piperidinas/síntese química , Piperidinas/química , Piperidinas/metabolismo , Canais de Potássio/metabolismo , Ratos , Ratos Wistar , Receptores de Droga/metabolismo , Estereoisomerismo , Relação Estrutura-Atividade , Compostos de Sulfonilureia/química , Compostos de Sulfonilureia/metabolismo , Compostos de Sulfonilureia/farmacologia , Receptores de Sulfonilureias
5.
AIDS Res Hum Retroviruses ; 12(3): 213-22, 1996 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-8835199

RESUMO

Human immunodeficiency virus (HIV) infection as seen in Europe and the United States has predominantly been contracted through male homosexual sex or intravenous drug abuse. In infected subjects, the brain is frequently affected both clinically and neuropathologically. The aim of this multicenter study has been to evaluate the value of single-voxel proton magnetic resonance spectroscopy (MRS) in the assessment of the neurological complications of acquired immunodeficiency syndrome (AIDS). MRS (voxel size = 8 ml, TR/TE = 1600/135 msec) was performed in 137 HIV-1-seropositive patients and 64 healthy controls without risk factors at three clinical MR sites operating at 1.5 T. The first result of this multicenter trial is that good reproducibility of results among participating sites was found. This demonstrates the reliability and robustness of MRS in the study of in vivo brain metabolism. In HIV patients, there was no significant correlation between metabolite ratios of brain detected by MRS and CDC grouping of patients or CD4 count. In contrast, the variations of brain metabolite ratios (NA/Cr, NA/Cho, and Cho/Cr) were related to the occurrence of encephalopathy, brain atrophy, or diffuse white matter lesions. There was no significant difference in brain metabolites between male homosexual AIDS patients and male intravenous drug user AIDS patients, whatever their neurological status (neurosymptomatic or neuroasymptomatic). Thus, the mode of transmission of HIV infection does not appear to affect the cerebral changes observed in the proton spectra from AIDS patients. Because of its ease of implementation and high information content, single-voxel proton MRS is likely to play a significant role in the evaluation of HIV-related encephalopathies.


Assuntos
Síndrome da Imunodeficiência Adquirida/patologia , Encéfalo/patologia , HIV-1 , Espectroscopia de Ressonância Magnética/métodos , Síndrome da Imunodeficiência Adquirida/diagnóstico , Síndrome da Imunodeficiência Adquirida/transmissão , Contagem de Linfócito CD4 , Feminino , Soropositividade para HIV/diagnóstico , Soropositividade para HIV/patologia , Soropositividade para HIV/transmissão , Humanos , Imageamento por Ressonância Magnética , Masculino , Imagens de Fantasmas
6.
J Neurol ; 217(3): 207-12, 1978 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-75956

RESUMO

Serum levels of IgA were found to be reduced in some patients with epilepsy. Further studies revealed that only epileptics with constitutional factors for seizures showed, if ever, IgA deficiency, particularly those treated with hydantoins (up to 25%). In order further to substantiate the association of immunoglobulin alterations with epilepsy nine families in whom the disease was clustered were investigated. An IgA deficiency was detected in 16 of the 19 epileptics (three without hydantoin medication), but in none of their 45 non-epileptic relatives. However, four of the relatives had a low IgM. Seven other families were tested in each of which only one IgA deficient epileptic was known. No other family members were found with a low IgA, but 24 of 58 such relatives had increased IgM serum concentrations. The association of IgA deficiency and epilepsy with IgM imbalances in relatives of IgA deficient epileptics gives additional support for the hypothesis that immune imbalances and certain forms of epilepsy might be linked.


Assuntos
Epilepsia/imunologia , Deficiência de IgA , Epilepsia/tratamento farmacológico , Epilepsia/genética , Feminino , Humanos , Hidantoínas/uso terapêutico , Imunoglobulina M/análise , Cadeias kappa de Imunoglobulina/análise , Cadeias lambda de Imunoglobulina/análise , Masculino , Linhagem
7.
J Magn Reson ; 134(2): 287-99, 1998 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9761704

RESUMO

Several pioneering studies have demonstrated that localized 31P NMR spectroscopy of the human heart might become an important diagnostic tool in cardiology. The main limitation is due to the low sensitivity of these experiments, allowing only crude spatial resolution. We have implemented a three-dimensional version of SLOOP ("spectral localization with optimal pointspread function") on a clinical instrument. SLOOP takes advantage of all available a priori information to match the size and the shape of the sensitive volumes to the anatomical structures in the examined subject. Thus, SLOOP reduces the contamination from adjacent organs and improves the sensitivity compared to conventional techniques such as ISIS or chemical shift imaging (CSI). Initial studies were performed on six healthy volunteers at 1.5 T. The good localization properties are demonstrated by the absence of resonances from blood in the heart spectra, and by PCr-free spectra from the liver. Compared to conventional CSI, the signal-to-noise ratio of the SLOOP heart spectra was improved by approximately 30%. Taking into account the varying excitation angle in the inhomogeneous B1 field of the surface coil, the SLOOP model computes the local spin saturation at every point in space. Therefore, no global saturation correction is required in the quantitative evaluation of local spectra. In this study, we found a PCr/gamma-ATP ratio in the left ventricular wall of 1.90 +/- 0.33 (mean +/- standard deviation).


Assuntos
Coração/anatomia & histologia , Espectroscopia de Ressonância Magnética , Fosfatos/análise , Trifosfato de Adenosina/análise , Adulto , Algoritmos , Feminino , Ventrículos do Coração/anatomia & histologia , Humanos , Processamento de Imagem Assistida por Computador/instrumentação , Fígado/anatomia & histologia , Espectroscopia de Ressonância Magnética/instrumentação , Masculino , Imagens de Fantasmas , Fosfocreatina/análise , Valores de Referência
8.
Med Phys ; 13(4): 510-3, 1986.
Artigo em Inglês | MEDLINE | ID: mdl-3736508

RESUMO

Nuclear magnetic resonance (NMR) spectroscopy of small lesions is restricted by the difficulties of localizing the surface coil with respect to the lesion and the problem of ensuring that signal is only obtained from the lesion and not from surrounding tissue. A double-tuned coil has been developed that permits NMR proton images to be obtained from a region of interest, prior to carrying out 31P spectroscopy of the same region with the same coil, without the need for further adjustment. The coil provides a means of accurately localizing the region from which the 31P signal is obtained, whilst offering a means of accurately applying 31P signal localization methods, and the possibility of making corrections for the nonuniform sensitivity of a given surface coil. The coil makes use of two parallel resonant circuits, with independent rf connections, but sharing a common coil. Simulated shorted and open circuit lambda /4 cables are used, respectively, to open circuit each circuit at the resonant frequency of the other circuit and ensure that the simulated lambda /4 line is short circuited for each circuit at the circuit's resonant frequency. At 63.6 MHz, the Q of the coil was 190 unloaded and 90 loaded, and at 25.7 MHz the Q was 210 unloaded and 140 loaded, for a 4-cm-diam coil. The coil has been used to obtain proton images and 31P spectra. A circuit employing only one input was also developed.


Assuntos
Espectroscopia de Ressonância Magnética/instrumentação , Humanos , Fósforo , Análise Espectral/instrumentação
9.
J Neurosurg ; 84(3): 449-58, 1996 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8609557

RESUMO

The authors represent a cooperative group of 15 institutions that examined the feasibility of using metabolic features observed in vivo with 1H-magnetic resonance (MR) spectroscopy to characterize brain tumors of the glial type. The institutions provided blinded, centralized MR spectroscopy data processing long with independent central review of MR spectroscopy voxel placement, composition and contamination by brain, histopathological typing using current World Health Organization criteria, and clinical data. Proton 1H-MR spectroscopy was performed using a spin-echo technique to obtain spectra from 8-cc voxels in the tumor and when feasible in the contralateral brain. Eighty-six cases were assessable, 41 of which had contralateral brain spectra. Glial tumors had significantly elevated intensities of choline signals, decreased intensities of creatine signals, and decreased intensities of N-acetylaspartate compared to brain. Choline signal intensities were highest in astrocytomas and anaplastic astrocytomas, and creatine signal intensities were lowest in glioblastomas. However, whether expressed relative to brain or as intratumoral ratios, these metabolic characteristics exhibited large variations within each subtype of glial tumor. The resulting overlaps precluded diagnostic accuracy in the distinction of low-and high-grade tumors. Although the extent of contamination of the 1H-MR spectroscopy voxel by brain had a marked effect on metabolite concentrations and ratios, selection of cases with minimal contamination did not reduce these overlaps. Thus, each type and grade of tumor is a metabolically hetero-geneous group. Lactate occurred infrequently and in all grades. Mobile lipids, on the other hand, occurred in 41% of high-grade tumors with higher mean amounts found in glioblastomas. This result, coupled with the recent demonstration that intratumoral mobile lipids correlate with microscopic tumor cell necrosis, leads to the hypothesis that mobile lipids observed in vivo in 1H-MR spectroscopy may correlate independently with prognosis of individual patients.


Assuntos
Neoplasias Encefálicas/metabolismo , Glioma/metabolismo , Adolescente , Adulto , Idoso , Análise de Variância , Astrocitoma/metabolismo , Encéfalo/metabolismo , Criança , Pré-Escolar , Colina/metabolismo , Creatina/metabolismo , Estudos de Viabilidade , Feminino , Glioblastoma/metabolismo , Humanos , Espectroscopia de Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Prótons
10.
Anticancer Res ; 16(3B): 1533-8, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8694522

RESUMO

Fifteen institutions cooperated to examine the ability of 1H MRS to characterize metabolism in vivo in 102 primary brain tumors. Spectra were acquired from single 8 cc voxels in the tumor using a spin-echo method with an echo time of 135 ms. The most intense lipid signal was that of fatty acyl methylene protons at 1.3 ppm. Intratumoral lipid signals were not detected in oligodendrogliomas, ependymomas, or meningiomas and were evident in only 1 of 6 primitive neuroectodermal tumors. Among 75 astrocytic tumors, lipid signals occurred in 16% of low grade astrocytomas (AS), 36% of anaplastic astrocytomas (AA), and 44% of glioblastomas (GB). The amount of lipids, expressed as a ratio of the intensity of the methylene signal to that of choline, increased progressively with histopathological grade (p = 0.05). Greater amounts of mobile lipids in vivo in GB, which usually contain necrosis, is in accord with the recently discovered correlation between the fraction of microscopic necrosis and the intensity of the mobile lipid signal observed ex vivo using 1H MRS. The observation of lipid signals in AA, which do not contain necrosis, suggests that mobile fatty acids may appear at a stage of metabolic insult that precedes microscopic signs of cell death, and raises the possibility of an independent correlation between 1H MRS-detectable lipids and prognosis in patients with astrocytic tumors.


Assuntos
Neoplasias Encefálicas/metabolismo , Metabolismo dos Lipídeos , Astrocitoma/metabolismo , Glioblastoma/metabolismo , Humanos , Lactatos/metabolismo , Ácido Láctico
11.
Hear Res ; 48(3): 241-6, 1990 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-2272933

RESUMO

Otic capsule osteogenesis is a common finding in temporal bones from autoimmune disease individuals. However, the underlying cellular mechanisms are poorly understood. Therefore, to better understand this relationship of autoimmune disease and otic capsule pathology, inner ear sclerotic lesions of the Palmerston North autoimmune disease mouse were histochemically stained to identify their content and potential osteogenic processes. Lesions stained positive for calcium, amyloid, fibrinoid, and glycoproteins (PAS), but negative for collagen, calcium oxalate, reticular fibers and glycosaminoglycans (Alcian Blue). Amyloid and fibrinoid deposition are associated with other immune disease, which suggests these local processes may provide a protein substructure that calcifies in lesion progression. Similar cellular mechanisms may underlie certain types or phases of human autoimmune otic capsule disease.


Assuntos
Doenças Autoimunes/patologia , Orelha Interna/patologia , Camundongos Mutantes/metabolismo , Amiloide/metabolismo , Animais , Doenças Autoimunes/genética , Doenças Autoimunes/metabolismo , Cálcio/metabolismo , Colágeno/metabolismo , Orelha Interna/metabolismo , Fibrina/metabolismo , Glicoproteínas/metabolismo , Glicosaminoglicanos/metabolismo , Histocitoquímica , Camundongos , Esclerose
12.
Magn Reson Imaging ; 7(4): 425-35, 1989.
Artigo em Inglês | MEDLINE | ID: mdl-2682116

RESUMO

Comparative phosphorus-31 magnetic resonance spectroscopy (MRS) and magnetic resonance imaging (MRI) of 15 patients with superficial masses such as sarcoma, carcinoma, lymphoma, adenoma, and tuberculosis revealed significant increased concentrations of phosphomonoester, phosphodiester, and inorganic phosphorus in the lesion, whereas the concentration of the phosphocreatine was lower in comparison to muscle tissue. In nearly all masses, pH showed a slight alkaline shift. Existence of necrotic regions detected by MRI was marked by an increase of inorganic phosphorous in the spectra. Tumor growth was characterized by raised concentrations of phosphomonoester. Follow-up studies in a case of lymphoma showed a six-fold decrease of the tumor, while the spectra indicated a gradual transition of tumor values to muscle values. A follow-up study during irradiation of a squamous cell carcinoma revealed a considerable decrease of inorganic phosphate and a subsequent increase of phosphodiester.


Assuntos
Neoplasias de Cabeça e Pescoço/diagnóstico , Espectroscopia de Ressonância Magnética/métodos , Adulto , Idoso , Meios de Contraste , Feminino , Seguimentos , Gadolínio DTPA , Humanos , Espectroscopia de Ressonância Magnética/instrumentação , Masculino , Pessoa de Meia-Idade , Compostos Organometálicos , Ácido Pentético , Fósforo
13.
Int J Clin Pharmacol Ther ; 32(4): 168-73, 1994 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8032575

RESUMO

In a multiple-dose crossover study in 18 healthy male volunteers the steady-state pharmacokinetics of Euphylong, which has been designed for once-daily evening administration, was investigated after conventional twice-daily administration. Under both modes of administration 2 plasma level profiles over 24-hours each were taken during steady-state (day 5/6 and day 8/9, respectively), in order to assess the reproducibility from day to day. The extent of absorption (AUC) was equivalent for both dosing schemes. The intentional differences in pharmacokinetic profiles between the once-daily and twice-daily administration were reflected in the maximum concentrations (15.0 vs 12.1 mg/l), the plateau time T75% Cmax (11.5 vs 17.1 hours), the percent peak-trough fluctuation (94 vs 47%) and the nocturnal excess (37 vs 4%). Results are given for day 8/9, but were practically identical on day 5/6. Thus, the twice-daily administration provides very smooth plasma levels over 24 hours, however, at the expense of the loss of the nocturnal excess which is of clinical relevance in the treatment of nocturnal asthma.


Assuntos
Teofilina/farmacocinética , Absorção , Administração Oral , Adulto , Cromatografia Líquida de Alta Pressão , Preparações de Ação Retardada , Esquema de Medicação , Meia-Vida , Humanos , Infusões Intravenosas , Masculino , Taxa de Depuração Metabólica , Teofilina/administração & dosagem , Teofilina/sangue
14.
Int J Clin Pharmacol Ther ; 33(6): 311-4, 1995 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7582380

RESUMO

Grapefruit juice inhibits the biotransformation of several drugs, including caffeine (23% clearance reduction), which is metabolized by the cytochrome P450 isoform CYP1A2. Since CYP1A2 also participates in theophylline biotransformation, a randomized change-over study on a possible interaction between grapefruit juice and theophylline was conducted. Twelve healthy young male nonsmokers were included (median 26 (range 23-30) years, weight 73 (65-85) kg). Theophylline was given as a single dose of 200 mg in solution (Euphyllin 200), diluted by 100 ml of either water or grapefruit juice (751 mg/l naringin). Subsequently, additional fractionated 0.91 of water or juice were administered until 16 hours postdose. Theophylline concentrations in plasma withdrawn up to 24 hours postdose were measured by HPLC, and its pharmacokinetics were estimated using compartment model independent methods. To compare between the 2 treatments, ANOVA based point estimates and 90% confidence intervals (given in parentheses) were calculated for the test (= grapefruit coadministration) to reference (= water coadministration) ratios (Tmax: differences). These were: Cmax 0.90 (0.81-1.00), AUC 1.02 (0.95-1.11), Cmax/AUC 0.88 (0.81-0.95), T 1/2el 1.03 (0.98-1.09), Tmax 0.15 h (-0.11h-0.41 h). Thus, no pharmacokinetic interaction between grapefruit juice and theophylline was observed. This finding is in contrast to the effect of grapefruit juice reported on caffeine metabolism and may be due to the contribution of enzymes other than CYP1A2 to primary theophylline metabolism or to differences in naringin and/or naringenin kinetics between studies.


Assuntos
Bebidas , Citrus/metabolismo , Flavanonas , Interações Alimento-Droga , Teofilina/farmacocinética , Absorção , Administração Oral , Adulto , Análise de Variância , Antioxidantes/farmacocinética , Antioxidantes/farmacologia , Biotransformação , Fracionamento Químico , Cromatografia Líquida de Alta Pressão , Estudos Cross-Over , Citocromo P-450 CYP1A2 , Sistema Enzimático do Citocromo P-450/metabolismo , Relação Dose-Resposta a Droga , Flavonoides/farmacocinética , Flavonoides/farmacologia , Meia-Vida , Humanos , Masculino , Oxirredutases/metabolismo , Valores de Referência , Teofilina/administração & dosagem , Teofilina/sangue
15.
Int J Clin Pharmacol Ther ; 36(3): 133-8, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9562228

RESUMO

UNLABELLED: Extent and rate of absorption of acetylsalicylic acid (ASA) from rapidly dispersing (Acesal Extra) and plain tablets (Acesal) relative to reference 1 (plain tablets, Aspirin) and from microcapsuled tablets (Micristin) relative to comparable listed tablets (reference 2, Colfarit) were assessed in 2 single-dose (0.5 g ASA), open, randomized, crossover studies with intervals of 14 days between 2 periods. Both studies were performed in 24 male and female healthy volunteers each (age 18-32 years, body weight 48-90 kg, body height 161-190 cm). ASA and its metabolite salicylic acid (SA) were measured with an HPLC method validated for ASA between 0.2 and 20 microg/ml and for SA between 0.4 and 40 microg/ml. The test tablets were considered bioequivalent with reference in extent of absorption if the 90% confidence limits of the AUC0 to infinity ratio were within the range of 0.80-1.25, and in rate of absorption if the confidence limits of the Cmax/AUC0 to infinity ratios were within 0.70-1.43. RESULTS: Geometric means and 90% confidence limits for the test/reference ratios of the comparisons Acesal vs reference 1, Acesal Extra vs reference 1 and Micristin vs reference 2 were 1.05 (0.97-1.13), 1.13 (1.05-1.22), 1.02 (0.92-1.14) for ASA AUC0 to infinity and 1.02 (0.96-1.07), 1.05 (0.99-1.11), 0.98 (0.91-1.04) for SA AUC0 to infinity, respectively. The results for Cmax/AUC of ASA were 1.16 (1.00-1.34), 1.72 (1.49-1.99), 0.83 (0.73-0.94) and of SA 1.02 (0.98-1.07), 1.07 (1.02-1.12), 0.93 (0.88-0.97). CONCLUSION: Acesal and Micristin were bioequivalent with the respective references in both extent and rate of absorption. Acesal Extra and reference 1 were bioequivalent with regard to extent only. Acesal Extra was absorbed faster.


Assuntos
Anti-Inflamatórios não Esteroides/farmacocinética , Aspirina/administração & dosagem , Aspirina/farmacocinética , Adulto , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/sangue , Área Sob a Curva , Aspirina/sangue , Disponibilidade Biológica , Estudos Cross-Over , Formas de Dosagem , Portadores de Fármacos , Composição de Medicamentos , Feminino , Humanos , Absorção Intestinal , Masculino , Valores de Referência , Equivalência Terapêutica
16.
Int J Clin Pharmacol Ther ; 33(8): 427-30, 1995 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8556220

RESUMO

Bioequivalence studies are usually performed as crossover studies and, therefore, information on the intrasubject coefficient of variation is needed for sample size planning. However, this information is usually not accessible in publications on bioequivalence studies, and only the pooled inter- and intrasubject coefficient of variation for either test or reference formulation is reported. It is the purpose of the present communication to provide reference values of the intrasubject coefficient of variation for various previously investigated drugs. The presentation includes pertinent pharmacokinetic characteristics for immediate- and extended-release formulations in single- and multiple-dose crossover studies.


Assuntos
Preparações Farmacêuticas/administração & dosagem , Padrões de Referência , Equivalência Terapêutica , Administração Oral , Estudos Cross-Over , Preparações de Ação Retardada , Formas de Dosagem , Guias como Assunto , Humanos , Injeções Intravenosas , Variações Dependentes do Observador , Valores de Referência
17.
Rofo ; 145(1): 43-8, 1986 Jul.
Artigo em Alemão | MEDLINE | ID: mdl-3016819

RESUMO

Chemical shift imaging permits separate demonstration of water and fat-bound protons in a selected plane. Compared with normal spin-echo sequences, specific information can be obtained in the investigation of internal joint structures. A pilot study was carried out on the possibility of showing normal and abnormal structures, using normal controls, and 16 patients with various joint abnormalities.


Assuntos
Artropatias/diagnóstico , Espectroscopia de Ressonância Magnética , Artrite Reumatoide/diagnóstico , Articulação do Quadril/anatomia & histologia , Humanos , Traumatismos do Joelho/diagnóstico , Articulação do Joelho , Espectroscopia de Ressonância Magnética/métodos , Osteoartrite/diagnóstico
18.
Rofo ; 143(6): 623-34, 1985 Dec.
Artigo em Alemão | MEDLINE | ID: mdl-3001851

RESUMO

Magnetic resonance tomography (MRI = magnetic resonance imaging) can provide sectional images of the petrous bones in all planes. It is complementary to computed tomography (CT) and can demonstrate inflammatory changes in the petrous bones and mastoids, and cholesteatomas, with accuracy and without artifacts. MRI is inferior to CT for the demonstration of bone destruction and this this limits its use in the diagnosis of glomus tumours. The use of special surface coils combined with thin sections and a gradient-zoom technique provides high resolution images which approach the quality of modern CT examinations. This opens new possibilities for the diagnosis of small acoustic neuromas; because of the excellent tissue contrast, they can be well demonstrated without using intravenous contrast media or intrathecal air (CT-air meatography).


Assuntos
Colesteatoma/diagnóstico , Neoplasias de Cabeça e Pescoço/diagnóstico , Espectroscopia de Ressonância Magnética , Mastoidite/diagnóstico , Adulto , Otopatias/diagnóstico , Feminino , Tumor do Glomo Jugular/diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade , Neuroma Acústico/diagnóstico , Otite Média/diagnóstico , Estudos Prospectivos , Tomografia Computadorizada por Raios X
19.
Rofo ; 143(1): 1-8, 1985 Jul.
Artigo em Alemão | MEDLINE | ID: mdl-2991996

RESUMO

Proton nuclear resonance tomography, also called magnetic resonance imaging, is a new imaging procedure which makes it possible to obtain tomographic cuts of the petrous bone in three planes. It is complementary to CT and is able to demonstrate the small structures of the inner ear and of the cerebello-pontine angle, without bone artefacts and without overlap or distortion. By using special surface coils combined with thin sections and a gradient-zoom technique, it is possible to obtain high resolution images which equal those of modern CT. By choosing suitable exposure parameters and a multi-echo technique, one can obtain excellent tissue contrast without using positive or negative contrast media.


Assuntos
Ângulo Cerebelopontino/anatomia & histologia , Espectroscopia de Ressonância Magnética , Osso Petroso/anatomia & histologia , Ângulo Cerebelopontino/diagnóstico por imagem , Humanos , Espectroscopia de Ressonância Magnética/métodos , Osso Petroso/diagnóstico por imagem , Tomografia Computadorizada por Raios X
20.
Rofo ; 157(4): 371-7, 1992 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-1327273

RESUMO

Twenty-two patients with intracranial tumours were examined by MR images and in vivo proton-MR-spectroscopy. The changes of relative concentrations of NAA, PCr/Cr, Cho, and Ins were measured spectroscopically and the amount of these metabolites were related to different tumour groups. Analysis of the results has shown that the spectra from all the tumours differed from normal spectra. All cerebral tumours showed marked reduction of the Pcr/Cho quotient and the NAA/Cho quotient was also reduced. The Ins/Cho quotient for meningiomas and metastases was also lower than in normals; in gliomas of low malignancy the quotient was slightly raised and in gliomas of greater malignancy it was significantly higher than normal. The spectra of cerebral metastases showed unusual high lipid signals of 0.9 ppm and 1.25 ppm. The only common feature for meningiomas was marked reduction of NAA concentration. In summary, localised in vivo proton-MR-spectroscopy can be used clinically to obtain valuable information for the differential diagnosis of gliomas and intracerebral metastases.


Assuntos
Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/secundário , Glioma/diagnóstico , Espectroscopia de Ressonância Magnética , Neoplasias Meníngeas/diagnóstico , Meningioma/diagnóstico , Diagnóstico Diferencial , Estudos de Avaliação como Assunto , Humanos , Espectroscopia de Ressonância Magnética/instrumentação , Espectroscopia de Ressonância Magnética/métodos , Prótons , Controle de Qualidade
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