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1.
Pediatr Surg Int ; 39(1): 191, 2023 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-37140693

RESUMO

PURPOSE: Preoperative evaluation of Image Defined Risk Factors (IDRFs) in neuroblastoma (NB) is crucial for determining suitability for upfront resection or tumor biopsy. IDRFs do not all carry the same weighting in predicting tumor complexity and surgical risk. In this study we aimed to assess and categorize a surgical complexity (Surgical Complexity Index, SCI) in NB resection. METHODS: A panel of 15 surgeons was involved in an electronic Delphi consensus survey to identify and score a set of shared items predictive and/or indicative of surgical complexity, including the number of preoperative IDRFs. A shared agreement included the achievement of at least 75% consensus focused on a single or two close risk categories. RESULTS: After 3 Delphi rounds, agreement was established on 25/27 items (92.6%). A severity score was established for each item ranging from 0 to 3 with an overall SCI range varying from a minimum score of zero to a maximum score of 29 points for any given patient. CONCLUSIONS: A consensus on a SCI to stratify the risks related to neuroblastoma tumor resection was established by the panel experts. This index will now be deployed to critically assign a better severity score to IDRFs involved in NB surgery.


Assuntos
Neuroblastoma , Humanos , Neuroblastoma/cirurgia , Neuroblastoma/patologia , Fatores de Risco , Cuidados Pré-Operatórios , Biópsia
2.
Med J Malaysia ; 76(4): 573-577, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34305122

RESUMO

Adult neuroblastoma (AN) is rare with an extremely poor prognosis. No standard therapy exists for this entity and treatment options are limited in recurrent or refractory disease. 131I-MIBG has been used in combination with myeloablative therapy before autologous bone marrow transplantation or in a salvage therapy setting. However, myelotoxicity is a dose-limiting factor in heavily pre-treated patients and response is not always sustained. Somatostatin receptor scintigraphy and theranostics with radiolabelled somatostatin receptor analogues are becoming more commonplace with the recognition of these receptors in over 90% of neuroblastoma cells. We describe three AN patients assessed for somatostatin receptor status and the novel use of 177Lu-based peptide recep-tor radionuclide therapy (PRRT) in two of them and a literature review.


Assuntos
Radioisótopos do Iodo , Neuroblastoma , 3-Iodobenzilguanidina/uso terapêutico , Adulto , Radioisótopos de Gálio , Humanos , Neuroblastoma/diagnóstico por imagem , Neuroblastoma/radioterapia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Cintilografia , Receptores de Somatostatina
3.
Anal Chem ; 90(23): 14063-14071, 2018 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-30398852

RESUMO

By combining DNA nanotechnology and high-bandwidth single-molecule detection in nanopipets, we demonstrate an electric, label-free hybridization sensor for short DNA sequences (<100 nucleotides). Such short fragments are known to occur as circulating cell-free DNA in various bodily fluids, such as blood plasma and saliva, and have been identified as disease markers for cancer and infectious diseases. To this end, we use as a model system an 88-mer target from the RV1910c gene in Mycobacterium tuberculosis, which is associated with antibiotic (isoniazid) resistance in TB. Upon binding to short probes attached to long carrier DNA, we show that resistive-pulse sensing in nanopipets is capable of identifying rather subtle structural differences, such as the hybridization state of the probes, in a statistically robust manner. With significant potential toward multiplexing and high-throughput analysis, our study points toward a new, single-molecule DNA-assay technology that is fast, easy to use, and compatible with point-of-care environments.


Assuntos
DNA/genética , Mycobacterium tuberculosis/genética , Nanotecnologia , Hibridização de Ácido Nucleico , Sequência de Bases , Eletrodos , Humanos
5.
Gesundheitswesen ; 74(7): 426-34, 2012 Jul.
Artigo em Alemão | MEDLINE | ID: mdl-21796590

RESUMO

AIM OF THE STUDY: A questionnaire was developed and validated which assesses factors influencing career choices of medical students and their perception of possibilities in general practice. METHODS: The first questionnaire version, which was developed based on a systematic literature review, was checked for comprehensibility and redundancy using concurrent think aloud. The revised version was filled out by a pilot sample of medical students and the factor structure was assessed using principal component analysis (PCA). The final version was filled out in an online survey by medical students of all 5 Medical Faculties in the federal state of Baden-Wuerttemberg. The factor structure was validated with a confirmatory factor analysis (CFA). Reliability was assessed as internal consistency using Cronbach's α. RESULTS: The questionnaire comprises 2 parts: ratings of (A) the individual importance and of (B) the possibilities in general practice on 5-point scales. The first version comprising 118 items was shortened to 63 items after conducting interviews using concurrent think aloud. A further 3 items giving no information were removed after piloting the questionnaire on 179 students. The 27 items of part A were structured in 7 factors (PCA): image, personal ambition, patient orientation, work-life balance, future perspectives, job-related ambition, and variety in job. This structure had a critical fit in the CFA applied to the final version filled out by 1 299 students. Internal consistency of the factors was satisfactory to very good (Cronbach's α=0.55-0.81). CONCLUSION: The questionnaire showed good psychometric properties. Further, not assessed factors influence career choice resulting in unexplained variance in our dataset and the critical fit of the model.


Assuntos
Escolha da Profissão , Comportamento de Escolha , Análise Fatorial , Psicometria/métodos , Estudantes de Medicina/estatística & dados numéricos , Inquéritos e Questionários , Adulto , Feminino , Alemanha , Humanos , Masculino , Adulto Jovem
6.
Allergy ; 64(8): 1172-8, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19254294

RESUMO

BACKGROUND: Genetic variants of the two adjacent genes, IL13 and IL4 have frequently been reported as being associated with susceptibility to atopy and asthma, both in adults and children, and some studies also suggest association with lung function and chronic obstructive pulmonary disease. METHODS: In this study, we examined for the first time the effect of these variants in 2918 adults in a longitudinal birth cohort, the British National Survey of Health and Development, where there are extensive life style, developmental and environmental data. We examine two IL13 single nucleotide polymorphisms (SNPs) IL13 rs20541 (R110Q) and rs1800925 (-1024C>T) and one IL4 SNP, rs2070874 (-33C>T) with likely function. RESULTS: We show that IL13 rs20541 and rs1800925 are each significantly associated with self-reported asthma and allergy, and that this association is not confounded by any of the known developmental and environmental risk factors for asthma and atopy, including in particular place of birth. IL13 rs20541 does however act as a confounder for the IL13 rs1800925 associations, meaning that there is no statistical support for rs1800925 having an independent effect. There is nevertheless evidence for interaction between smoking and rs1800925, with allergy as outcome. None of the SNPs showed association with measures of lung function, nor any interaction with the effect of smoking on lung function. CONCLUSION: In a longitudinal population cohort we have established a role for polymorphism of IL13 in determining susceptibility to both atopy and asthma.


Assuntos
Predisposição Genética para Doença , Hipersensibilidade/genética , Interleucina-13/genética , Adulto , Asma/genética , Feminino , Seguimentos , Humanos , Hipersensibilidade Imediata/genética , Interleucina-4/genética , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Rinite Alérgica Sazonal/genética , Fatores de Risco , Fumar , Reino Unido
7.
Science ; 191(4229): 852-4, 1976 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-1251197

RESUMO

A number of minor and trace elements including Be, C, Ca, Cr, K, Li, Mn, Na, P, Pb, S, Tl, V, and Zn present in coal fly ash are found to be preferentially concentrated on the particle surfaces. Environmentally effective concentrations of these elements are thus much higher than indicated by conventional bulk analyses.


Assuntos
Poluentes Atmosféricos/análise , Oligoelementos/análise , Propriedades de Superfície
8.
Infection ; 37(1): 34-8, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19139812

RESUMO

BACKGROUND: The Hand Hygiene Liaison Group and Epic Projects (Pratt et al., J Hosp Infect 47[Suppl A], 2001) have asked specifically for further trials of educational interventions to improve hand decontamination compliance and infection control in the hospital setting. This study investigates the efficacy of a 'clean practice protocol' (CPP), derived from international guidelines, to improve compliance of infection-control practices by surgical teams in a large UK teaching hospital. METHODS: The key infection-control activities were summated to form the CPP presented here. An undisclosed infection-control audit of consultant-led ward-rounds from breast, gastrointestinal, vascular, urological, and intensive care departments was performed. The audit results were presented to the surgical teams, after which an education/awareness program was implemented. A repeat undisclosed audit was performed 3 months later. In both audits, infection-control activities were recorded together with consultation time and any patient infective complications. RESULTS: The surgical teams performed as follows in the initial audit: hand decontamination (28% of consultations), correct use of gloves (2%), instrument cleaning (0%), garment contamination (49%), and notes contamination (34%). Introduction of the CPP education program significantly improved hand decontamination to 87% (p < 0.0001), the correct use of gloves/aprons to 50% (p < 0.0001), and overall infection-control practice from 63% to 89% (p < 0.05). CONCLUSIONS: The introduction of the CPP significantly improved compliance of hand decontamination, correct usage of gloves and aprons, and overall infection-control in a large teaching hospital. The CPP is a highly effective auditing and educational tool that can be readily adapted for use in hospitals globally to monitor and improve infection-control practices.


Assuntos
Fidelidade a Diretrizes/estatística & dados numéricos , Desinfecção das Mãos/métodos , Pessoal de Saúde , Controle de Infecções/métodos , Atitude do Pessoal de Saúde , Infecção Hospitalar/prevenção & controle , Educação Profissionalizante , Luvas Protetoras/estatística & dados numéricos , Hospitais de Ensino , Humanos , Infecção da Ferida Cirúrgica/prevenção & controle , Reino Unido
9.
Br J Cancer ; 98(10): 1675-81, 2008 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-18475301

RESUMO

Alterations in epithelial mucin expression are associated with carcinogenesis, but there are few data in biliary tract cancer (BTC). In pancreatic malignancy, MUC4 is a diagnostic and prognostic tumour marker, whereas MUC5AC has been proposed as a sensitive serological marker for BTC. We assessed MUC4 and MUC5AC expression in (i) prospectively collected bile and serum specimens from 72 patients with biliary obstruction (39 BTC) by real-time reverse transcriptase-PCR (qPCR) and western blot analysis, and (ii) 79 archived biliary tissues (69 BTC) by immunohistochemistry. In bile, MUC4 protein was detected in 27% of BTC and 29% of primary sclerosing cholangitis (PSC) cases, but not in other benign and malignant biliary diseases (P<0.01 and P=0.06). qPCR revealed a 1.9-fold increased MUC4 mRNA expression in BTC patients' bile compared with benign disease. In archived tissues, MUC4 protein was detected in 37% of BTC but in none of the benign samples (P=0.03). In serum, MUC5AC was found exclusively in BTC and PSC sera (44% and 13%, respectively; P<0.001 for BTC vs non-BTC) and correlated negatively with BTC survival. Biliary MUC4 and serum MUC5AC are highly specific tumour-associated mucins that may be useful in the diagnosis and formulation of therapeutic strategies in BTC.


Assuntos
Bile/metabolismo , Neoplasias do Sistema Biliar/metabolismo , Biomarcadores Tumorais/metabolismo , Mucinas/sangue , Mucinas/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias do Sistema Biliar/sangue , Neoplasias do Sistema Biliar/patologia , Biomarcadores Tumorais/sangue , Western Blotting , Feminino , Seguimentos , Regulação Neoplásica da Expressão Gênica , Humanos , Imuno-Histoquímica , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Mucina-5AC , Mucina-4 , Estadiamento de Neoplasias , Valor Preditivo dos Testes , Estudos Prospectivos , Reação em Cadeia da Polimerase Via Transcriptase Reversa
10.
J Hum Hypertens ; 22(1): 63-70, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17728797

RESUMO

The prevalence of hypertension continues to rise across the world, and most patients who receive medical intervention are not adequately treated to goal. A Working Group including representatives of nine international health-care organizations was convened to review the barriers to more effective blood pressure control and propose actions to address them. The group concluded that tackling the global challenge of hypertension will require partnerships among multiple constituencies, including patients, health-care professionals, industry, media, health-care educators, health planners and governments. Additionally, health-care professionals will need to act locally with renewed impetus to improve blood pressure goal rates. The Working Group identified five core actions, which should be rigorously implemented by practitioners and targeted by health systems throughout the world: (1) detect and prevent high blood pressure; (2) assess total cardiovascular risk; (3) form an active partnership with the patient; (4) treat hypertension to goal and (5) create a supportive environment. These actions should be pursued with vigour in accordance with current clinical guidelines, with the details of implementation adapted to the economic and cultural setting.


Assuntos
Saúde Global , Hipertensão/prevenção & controle , Guias de Prática Clínica como Assunto , Atenção à Saúde/normas , Diretrizes para o Planejamento em Saúde , Humanos , Cooperação do Paciente , Medição de Risco
12.
Orbit ; 27(3): 207-9, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18569831

RESUMO

BACKGROUND: Mazabraud's syndrome was first described, by Mazabraud et al. as a rare disease, associated with single or multiple intramuscular myxomas with monostotic or polyostotic forms of fibrous dyplasia, PURPOSE: Reports of this syndrome is rare and usually associated with myoxomatas. The authors would want to report the occurrence of this rare case associated with a hamartoma as basis for record and future studies. METHOD: An adult male came to the institution 4 years ago complaining of a right unilateral proptosis that he had since childhood. However, proptosis progressed in a month's time accompanied by right eye redness. Right eye was congested with a palpable firm mass on the right lower lid. Best corrected visual acuity was 6/15-2. Pupillary examination revealed the presence of RAPD on the right eye. Exophthalmometry revealed a 10 mm proptosis. EOMS were restricted on the right eye and diplopia was noted in all gazes. Ishihara test showed 14/15 for the right eye. CT SCAN and MRI confirmed a mild inflammatory extraconal or intramuscular mass in the right obito-retrobulbar region. Bony changes seen in the right zygoma, sphenoid bone and squamous part of the temporal bone with extensive bone mineralization. The patient underwent a right lateral orbitotomy with biopsy and debulking of the inferior orbital mass. Histopathology revealed a hamartomatous lesion. CONCLUSION: Due to the associated soft tissue lesion with multiple craniofacial bone changes, this case may be considered a variant of Mazabraud's Syndrome. The associated hamatomatous lesion may be a rare occurrence that should be noted.


Assuntos
Displasia Fibrosa Óssea/patologia , Hamartoma/diagnóstico , Doenças Orbitárias/diagnóstico , Neoplasias de Tecidos Moles/diagnóstico , Biópsia por Agulha , Exoftalmia/diagnóstico , Exoftalmia/etiologia , Displasia Fibrosa Óssea/diagnóstico , Displasia Fibrosa Óssea/cirurgia , Seguimentos , Hamartoma/prevenção & controle , Hamartoma/cirurgia , Humanos , Imuno-Histoquímica , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Doenças Orbitárias/patologia , Doenças Orbitárias/cirurgia , Medição de Risco , Neoplasias de Tecidos Moles/patologia , Neoplasias de Tecidos Moles/cirurgia , Síndrome , Tomografia Computadorizada por Raios X , Resultado do Tratamento
13.
J Hosp Infect ; 100(2): 183-189, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29649558

RESUMO

BACKGROUND: Various technologies have been developed to improve hand hygiene (HH) compliance in inpatient settings; however, little is known about the feasibility of machine learning technology for this purpose in outpatient clinics. AIM: To assess the effectiveness, user experiences, and costs of implementing a real-time HH notification machine learning system in outpatient clinics. METHODS: In our mixed methods study, a multi-disciplinary team co-created an infrared guided sensor system to automatically notify clinicians to perform HH just before first patient contact. Notification technology effects were measured by comparing HH compliance at baseline (without notifications) with real-time auditory notifications that continued till HH was performed (intervention I) or notifications lasting 15 s (intervention II). User experiences were collected during daily briefings and semi-structured interviews. Costs of implementation of the system were calculated and compared to the current observational auditing programme. FINDINGS: Average baseline HH performance before first patient contact was 53.8%. With real-time auditory notifications that continued till HH was performed, overall HH performance increased to 100% (P < 0.001). With auditory notifications of a maximum duration of 15 s, HH performance was 80.4% (P < 0.001). Users emphasized the relevance of real-time notification and contributed to technical feasibility improvements that were implemented in the prototype. Annual running costs for the machine learning system were estimated to be 46% lower than the observational auditing programme. CONCLUSION: Machine learning technology that enables real-time HH notification provides a promising cost-effective approach to both improving and monitoring HH, and deserves further development in outpatient settings.


Assuntos
Instituições de Assistência Ambulatorial , Infecção Hospitalar/prevenção & controle , Fidelidade a Diretrizes , Higiene das Mãos , Aprendizado de Máquina , Custos e Análise de Custo , Humanos , Projetos Piloto , Fatores de Tempo
14.
Patient Educ Couns ; 63(3): 319-27, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16872793

RESUMO

OBJECTIVE: Due to a lack of valid German instruments measuring shared decision-making (SDM), a theory-driven questionnaire (SDM-Q) to measure the process of SDM was developed and validated. METHODS: As a theoretical basis steps of the SDM process were defined in an expert panel. Item formulation was then conducted according to the Delphi method. For the first validation on a mixed sample Rasch analysis was used to eliminate items not fitting the construct thus receiving a unidimensional scale. RESULTS: After eliminating 4 items the remaining 11 form a unidimensional scale with an acceptable reliability for person measures (0.77) and very good reliability for item difficulties (0.95). Analysis of subgroups revealed a different use of items in different conditions. Furthermore the scale showed high ceiling effects. CONCLUSION: A new theory-driven instrument to measure the process of SDM has been developed and validated by use of a rigorous method revealing first promising results. Yet the ceiling effects require the addition of more discriminating items, and the different use of items in different conditions demands an in depth analysis. PRACTICE IMPLICATIONS: While the concept of SDM is constantly receiving more attention in medical practice, its valid and reliable measurement remains challenging.


Assuntos
Tomada de Decisões , Participação do Paciente , Inquéritos e Questionários , Feminino , Alemanha , Humanos , Masculino , Pessoa de Meia-Idade , Psicometria , Reprodutibilidade dos Testes
15.
J Clin Endocrinol Metab ; 49(5): 663-71, 1979 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-158599

RESUMO

PIP: 25 young women, 13 of whom on oral contraception (OC), were observed to study the effects of exercise and of OC on the blood fibrinolytic and renin systems. It appeared very clearly that exercise would activate the fibrinolytic system, and that renin activity was also stimulated, suggesting a relationship between the 2 systems. The connection between exercise, fibrinolysis and prorenin activity was evidenced by an exercise-induced drop in the proportion of inactive renin and fibrinolytic activity, and in the presence of contraceptive-induced activation of fibrinolysis. OC did not seem to raise plasma prorenin above the control value, but it did raise active-renin, especially late in the menstrual cycel.^ieng


Assuntos
Anticoncepcionais Orais , Precursores Enzimáticos/sangue , Fibrinólise , Esforço Físico , Renina/sangue , Adulto , Angiotensina I/sangue , Pressão Sanguínea , Ativação Enzimática , Feminino , Fibrinogênio/metabolismo , Fibrinolisina/metabolismo , Congelamento , Frequência Cardíaca , Humanos , Masculino , Plasminogênio/análise , Trombina/metabolismo
16.
J Nucl Med ; 39(3): 484-9, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9529296

RESUMO

UNLABELLED: A model that describes the pharmacokinetic distribution of 131I-labeled G250 antibody is developed. METHODS: Previously collected pharmacokinetic data from a Phase I-II study of 131I-G250 murine antibody against renal cell carcinoma were used to develop a mathematical model describing antibody clearance from serum and the whole body. Survey meter measurements, obtained while the patient was under radiation precautions, and imaging data, obtained at later times, were combined to evaluate whole-body clearance kinetics over an extended period. RESULTS: A linear two-compartment model was found to provide good fits to the data. The antibody was injected into Compartment 1, the initial distribution volume (Vd) of the antibody, which included serum. The antibody exchanged with the rest of the body, Compartment 2, and was eventually excreted. Data from 13 of the 16 patients fit the model with unique parameters; the maximum, median and minimum values for model-derived Vd were 6.3, 3.7 and 2.11, respectively. The maximum, median and minimum values for the excretion rate were 8 x 10(-2), 2.4 x 10(-2) and 1.3 x 10(-2) hr(-1), respectively. Parameter sensitivity analysis showed that a change in the transfer rate constant from serum to the rest of the body had the greatest effect on serum cumulative activity and that the rate constant for excretion had the greatest effect on whole-body cumulative activity. CONCLUSION: A linear two-compartment model was adequate in describing the serum and whole-body kinetics of G250 antibody distribution. The median initial distribution volume predicted by the model was consistent with the nominal value of 3.81. A wide variability in fitted parameters was observed among patients, reflecting the differences in individual patient clearance and exchange kinetics of G250 antibody. By selecting median parameter values, such a model may be used to evaluate and design prolonged multiple administration radioimmunotherapy protocols.


Assuntos
Anticorpos Monoclonais/farmacocinética , Antineoplásicos/farmacocinética , Carcinoma de Células Renais/radioterapia , Radioisótopos do Iodo/uso terapêutico , Neoplasias Renais/radioterapia , Radioimunoterapia , Adulto , Idoso , Anticorpos Monoclonais/uso terapêutico , Antineoplásicos/uso terapêutico , Carcinoma de Células Renais/metabolismo , Feminino , Humanos , Neoplasias Renais/metabolismo , Masculino , Pessoa de Meia-Idade , Modelos Teóricos , Distribuição Tecidual
17.
Biochem Pharmacol ; 31(4): 553-9, 1982 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-6895995

RESUMO

Analgesia and brain and plasma concentrations of (-)-3-phenoxy-N-methylmorphinan (PMM) and its metabolites were determined in rats administered 50 mg/kg of 3H-labeled PMM p.o., an approximate ED50. Unchanged PMM and two active metabolites, levorphanol and a different phenol, p-hydroxylated on the 3-phenoxy group (pOH-PMM), were present in brain at concentrations greater than in plasma. Analgesia was observed from 1 to 6 hr and was associated with brain concentrations of 400-1400 ng/g of PMM, 190-300 ng/g of pOH-PMM, and 16-27 ng/g of levorphanol. The presence of 58% of the administered dose as unchanged PMM in the gastrointestinal tract at 6 hr may reflect slow absorption and explain the persisting brain concentrations of PMM and its metabolites as well as the prolonged analgesia. Analgesia may have been due to the presence in brain of only PMM, pOH-PMM or levorphanol, or to the combined activity of two or three of these substances. Administration of the approximate ED50 of 3H-labeled levorphanol (0.1 mg/kg, s.c., or 6 mg/kg, p.o.) resulted in brain levorphanol concentrations (11-18 ng/g) close to those observed when PMM was administered p.o. at 50 mg/kg. After administration of an approximate subcutaneous ED50 of [3H]pOH-PMM of 24 mg/kg, the brains contained pOH-PMM (1500-4100 ng/g) and levorphanol (60-100 ng/g); these levorphanol concentrations were higher than those found after administration of the approximate ED50 of PMM or levorphanol. The findings indicate that brain levorphanol concentrations resulting from administration of PMM or pOH-PMM to rats may account for the analgesic activity observed, i.e. that PMM and pOH-PMM may act as prodrugs for levorphanol


Assuntos
Analgésicos/farmacologia , Encéfalo/metabolismo , Levorfanol/análogos & derivados , Analgésicos/sangue , Analgésicos/metabolismo , Animais , Relação Dose-Resposta a Droga , Mucosa Intestinal/metabolismo , Levorfanol/sangue , Levorfanol/metabolismo , Levorfanol/farmacologia , Masculino , Ratos , Ratos Endogâmicos
18.
J Neurol Sci ; 122(1): 117-24, 1994 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8195797

RESUMO

We describe a validation study of a new technique for detecting circulating pathological cerebral emboli. Theoretically one would expect solid emboli to be detectable as high intensity signals on the Doppler waveform, and such signals have been reported in humans with potential embolic sources. Pathological cerebral emboli (thrombi, platelet aggregates and atheroma) were introduced into the proximal carotid artery of an in vivo sheep model, and their passage detected in the cerebral circulation using Doppler ultrasound. All of 74 emboli, with a maximum dimension as small as 0.24 mm, were detected as short duration high intensity signals. Smaller pathological emboli could not be made but glass microspheres as small as 5-20 micron resulted in high intensity signals. A significant positive correlation was found between embolus size and relative intensity increase of the embolic signal. A significant positive correlation was also found between embolus size and duration of embolic signal. This study demonstrates that detection of circulating cerebral emboli is possible in vivo. This technique may allow selection of patients at particularly high risk of cerebral embolisation so that they can be given specific prophylactic treatment. Analysis of the Doppler signal may give information on the size of the embolus, although using current signal analysis it is impossible to distinguish between the signals produced by say a larger platelet embolus or a smaller thrombus embolus.


Assuntos
Embolia e Trombose Intracraniana/diagnóstico por imagem , Animais , Encéfalo/patologia , Artérias Carótidas/diagnóstico por imagem , Circulação Cerebrovascular , Modelos Animais de Doenças , Ecoencefalografia/instrumentação , Embolia e Trombose Intracraniana/patologia , Embolia e Trombose Intracraniana/fisiopatologia , Microesferas , Ovinos
19.
Life Sci ; 54(26): PL483-90, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-8208055

RESUMO

Ro 24-4736, a new platelet activating factor antagonist, is currently under preclinical and clinical development. The tissue distribution of the 14C-label in male rats following a single intravenous dose of 1.0 mg/kg of 14C-Ro 24-4736 indicated appreciable uptake by the liver, kidney, heart and gastrointestinal tract. Peak plasma and tissue concentrations were seen at 5 minutes after dosing except for the small intestine (4 hrs) and abdominal fat, stomach and large intestine (4 hrs). Thereafter, the 14C-label rapidly declined in all tissues. At 48 hours, only 3.5% of the dose was present in the tissues, and 6.1% in the lumen of the gastrointestinal tracts. The excretion of 14C was essentially completed; 94% of the administered 14C was excreted in the feces and 4.0% in the urine. Overall recoveries of the administered 14C label ranged from 96 to 116%. The purified major 14C-labelled component in the fecal extracts yielded essentially the same NMR spectrum as authentic Ro 24-4736 which accounted for 11% of the dose. In vitro incubations of Ro 24-4736 with rat liver 9S supernatant in an NADPH generating system produced two metabolites. NMR spectra indicated that one metabolite was hydroxylated at carbon-1 while the other one contained a hydroxyl at carbon-10 of the parent molecule. Interestingly, the sites of hydroxylation were at carbons C1, and C10 bearing the protons guarding the bay area of the phenanthrenoid ring, rather than carbons of the phenyl-methyl-thienotriazolodiazepine moiety.


Assuntos
Fígado/metabolismo , Fenantridinas/metabolismo , Fator de Ativação de Plaquetas/antagonistas & inibidores , Triazinas/metabolismo , Animais , Biotransformação , Radioisótopos de Carbono , Injeções Intravenosas , Fígado/efeitos dos fármacos , Espectroscopia de Ressonância Magnética/métodos , Masculino , Espectrometria de Massas , Fenantridinas/administração & dosagem , Fenantridinas/farmacocinética , Fenobarbital/farmacologia , Técnica de Diluição de Radioisótopos , Ratos , Ratos Sprague-Dawley , Distribuição Tecidual , Triazinas/administração & dosagem , Triazinas/farmacocinética
20.
J Pharm Sci ; 67(8): 1138-41, 1978 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-671253

RESUMO

A radiochemical GLC analysis was developed for 3H-labeled ethinyl estradiol in human urine. The technique was applied to the unconjugated and aglycone fractions of urine collected from women who were dosed orally with: (a) single capsules containing 2.0 mg of 3H-quinestrol (900 muCi) and 2.5 mg of unlabeled quingestanol acetate dissolved in sesame oil and (b) single tablets containing 100 microgram of 3H-quinestrol (86 muCi). Unconjugated ethinyl estradiol in Day 1 urine collections represented means of 0.02% of the high quinestrol dose and 0.12% of the low dose. Ethinyl estradiol glucuronide in the same collections represented means of 0.55% of the high drug dose and 1.35% of the low dose. The method could detect 1-ng quantities of 3H-ethinyl estradiol and 3H-quinestrol.


Assuntos
Etinilestradiol/urina , Adulto , Cromatografia Gasosa , Feminino , Humanos , Métodos , Pessoa de Meia-Idade , Quinestrol/urina
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