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1.
Ir Med J ; 108(7): 219-20, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26349356

RESUMO

The postnatal period offers an opportunity to provide information and education to new mothers. We analysed factors associated with unscheduled presentations of newborns to local primary care, maternity and paediatric services over a 3 week period to assess whether these could be targeted with discharge planning educational interventions. Data was collected prospectively from electronic databases and manually from patient records in the maternity hospital. Two hundred and seventy six patients under 6 weeks of age presented to the three services. Half of these visits were unscheduled 137 (49%). 40 (29%) of those that were unscheduled were felt to represent benign neonatal variants whilst 28 (20%) presented with feeding problems. Eighty one (59.3%) patients were discharged home, and this was unaffected by referrer patterns; GPs 19 (56%), Nurses 13 (57%) or parents77 (67%). At least 40 (29%) of reviews were felt to be inappropriate and could have been prevented. There is room for cost saving and quality improvement of the service through education.


Assuntos
Continuidade da Assistência ao Paciente/organização & administração , Educação não Profissionalizante , Mau Uso de Serviços de Saúde/prevenção & controle , Alta do Paciente/normas , Cuidado Pós-Natal , Adulto , Agendamento de Consultas , Educação não Profissionalizante/métodos , Educação não Profissionalizante/organização & administração , Feminino , Medicina Geral/estatística & dados numéricos , Maternidades/estatística & dados numéricos , Humanos , Recém-Nascido , Irlanda , Masculino , Enfermagem Neonatal/estatística & dados numéricos , Cuidado Pós-Natal/métodos , Cuidado Pós-Natal/organização & administração
2.
Int J Sports Med ; 36(5): 419-25, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25664998

RESUMO

In the management of sports-related concussion, little is known about the effect of wearing or not wearing a helmet (i. e., helmet status) on the acute outcomes of concussed athletes. We endeavored to assess acute neurocognitive and symptom changes after SRC in helmeted vs. unhelmeted athletes. In a retrospective study, 1 025 athletes from 2 regional databases sustained a SRC. Athletes were matched by age, gender, number of prior concussions, and days to post-concussion test, yielding a final cohort of 138 athletes. For each group of 69, differences in post-concussion neurocognitive and symptom scores were compared using group mean differences as well as reliable change index (RCI) scores set at the 80% confidence interval. With gender, prior concussions, and days to post-concussion test similar in each group, using group mean change scores and RCI methodology, we found no significant differences between the helmeted and unhelmeted groups in 4 neurocognitive tests and one total symptom score. In a cohort of carefully matched athletes from 2 regional concussion centers, helmet status was unrelated to neurocognitive scores and total symptoms in athletes after suffering a SRC. These findings suggest that acute outcomes in helmeted vs. unhelmeted sports are quite similar.


Assuntos
Traumatismos em Atletas/diagnóstico , Concussão Encefálica/diagnóstico , Dispositivos de Proteção da Cabeça , Adolescente , Feminino , Humanos , Masculino , Testes Neuropsicológicos , Prognóstico , Estudos Retrospectivos
3.
Nature ; 492(7429): 393-5, 2012 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-23257880

RESUMO

Globular star clusters that formed at the same cosmic time may have evolved rather differently from the dynamical point of view (because that evolution depends on the internal environment) through a variety of processes that tend progressively to segregate stars more massive than the average towards the cluster centre. Therefore clusters with the same chronological age may have reached quite different stages of their dynamical history (that is, they may have different 'dynamical ages'). Blue straggler stars have masses greater than those at the turn-off point on the main sequence and therefore must be the result of either a collision or a mass-transfer event. Because they are among the most massive and luminous objects in old clusters, they can be used as test particles with which to probe dynamical evolution. Here we report that globular clusters can be grouped into a few distinct families on the basis of the radial distribution of blue stragglers. This grouping corresponds well to an effective ranking of the dynamical stage reached by stellar systems, thereby permitting a direct measure of the cluster dynamical age purely from observed properties.

4.
Nature ; 462(7276): 1028-31, 2009 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-20033041

RESUMO

Stars in globular clusters are generally believed to have all formed at the same time, early in the Galaxy's history. 'Blue stragglers' are stars massive enough that they should have evolved into white dwarfs long ago. Two possible mechanisms have been proposed for their formation: mass transfer between binary companions and stellar mergers resulting from direct collisions between two stars. Recently the binary explanation was claimed to be dominant. Here we report that there are two distinct parallel sequences of blue stragglers in M 30. This globular cluster is thought to have undergone 'core collapse', during which both the collision rate and the mass transfer activity in binary systems would have been enhanced. We suggest that the two observed sequences are a consequence of cluster core collapse, with the bluer population arising from direct stellar collisions and the redder one arising from the evolution of close binaries that are probably still experiencing an active phase of mass transfer.

5.
Clin Dysmorphol ; 16(3): 197-201, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17551338

RESUMO

Primary hypertrophic osteoarthropathy is a condition characterized by clubbing, arthropathy and periostosis of long tubular bones. Three variants of primary hypertrophic osteoarthropathy are distinguished: pachydermoperiostosis, which shows as additional symptom pachydermia; cranio-osteoarthropathy, which has a decreased neurocranium ossification as additional feature; and a secondary form. Primary hypertrophic osteoarthropathy is also genetically heterogeneous, with evidence for both autosomal dominant and autosomal recessive inheritance. We describe two sibs with cranio-osteoarthropathy and briefly review previously reported cases. The present cases demonstrate the phenotypic variability of the condition. The consanguinity in the present family and analysis of previously described cases support autosomal recessive inheritance for cranio-osteoarthropathy.


Assuntos
Osteoartropatia Hipertrófica Primária/patologia , Irmãos , Crânio/anormalidades , Pré-Escolar , Feminino , Mãos/diagnóstico por imagem , Humanos , Lactente , Masculino , Radiografia , Crânio/diagnóstico por imagem
6.
Pharm Res ; 18(7): 899-906, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11496947

RESUMO

PURPOSE: The purpose of our study was to develop an injectable polymeric system for the long-term localized delivery of bioactive interleukin-2 for antitumor immunotherapy. METHODS: IL-2 was encapsulated into gelatin and chondroitin-6-sulfate using an aqueous-based complex coacervation. CTLL-2 cells were used to measure the bioactivity of released IL-2 and radiolabeled IL-2 was used for release studies in the rat brain and mouse liver. Antitumor efficacy studies were carried out in primary (9L gliosarcoma) and metastatic (B16-F10 melanoma) brain tumor models in rats and mice, respectively, as well as a murine liver tumor model (CT26 carcinoma). Survivors of the metastatic brain tumor challenge were rechallenged with tumor in the opposite lobe of the brain to confirm that antitumor immunologic memory had developed. RESULTS: Bioactive IL-2 was released for over 2 weeks in vitro and in vivo IL-2 release showed significant IL-2 levels for up to 21 days. Polymeric IL-2 microspheres injected intratumorally were statistically more effective in protecting animals challenged with fatal tumor doses in the brain and the liver than placebo or autologous tumor cells genetically engineered to secrete IL-2. Immunologic memory was induced following IL-2 microsphere therapy in the B16-F10 brain tumor model that was capable of protecting 42% of animals from a subsequent intracranial tumor challenge, suggesting that tumor destruction was mediated by the immune system. CONCLUSIONS: Local IL-2 therapy using novel polymeric carriers. aimed at stimulating long-lasting antitumor immunity, may provide an improved method of treating a variety of cancers.


Assuntos
Antineoplásicos/administração & dosagem , Materiais Biocompatíveis/administração & dosagem , Neoplasias Encefálicas/tratamento farmacológico , Sistemas de Liberação de Medicamentos/métodos , Interleucina-2/administração & dosagem , Neoplasias Hepáticas Experimentais/tratamento farmacológico , Animais , Materiais Biocompatíveis/metabolismo , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/prevenção & controle , Neoplasias Hepáticas Experimentais/prevenção & controle , Melanoma Experimental , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Microesferas , Polímeros/administração & dosagem , Polímeros/metabolismo , Ratos , Ratos Endogâmicos F344 , Células Tumorais Cultivadas
7.
J Immunother ; 23(4): 438-48, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10916753

RESUMO

To explore the potential efficacy of local cytokine delivery against tumors in the central nervous system (CNS), C57BL6 mice were simultaneously given intracranial injections of tumor challenge and of irradiated B16F10 melanoma cells transduced to secrete interleukin-2 (IL-2). Intracranial IL-2 therapy generated antitumor responses capable of extending the survival of animals that received simultaneous intracranial tumor challenge either locally or at distant sites in the brain. Nontransduced melanoma cells had little effect. Animals that survived intracranial IL-2 therapy and tumor challenge showed prolonged survival compared with controls when challenged with a second tumor dose 70 days after initial treatment. In addition, animals that rejected intracranial tumors were also protected from tumor growth upon rechallenge at sites outside the CNS (i.e., subcutaneous tumor challenge). Conversely, identical or 10-fold larger doses of IL-2-transduced cells administered by subcutaneous injection failed to generate protection against intracranial tumor challenges. Elimination of T-cell and natural killer (NK) subsets using gene knockout mice and antibody-depletion techniques demonstrated that NK cells were most important for the initial antitumor response, whereas CD4+ T-cells were not necessary. These studies demonstrate that local IL-2 therapy in the brain not only generates an immediate local antitumor immune response, but also establishes long-term immunologic memory capable of eliminating subsequent tumor challenges within and outside of the CNS. Furthermore, the antitumor response to paracrine IL-2 in the brain differed significantly from that in the flank, suggesting that the intrinsic CNS cells involved in initiating immunity within the brain have different cytokine requirements from their peripheral counterparts.


Assuntos
Neoplasias Encefálicas/imunologia , Neoplasias Encefálicas/terapia , Interleucina-2/administração & dosagem , Interleucina-2/imunologia , Melanoma Experimental/imunologia , Melanoma Experimental/terapia , Adjuvantes Imunológicos/administração & dosagem , Adjuvantes Imunológicos/genética , Animais , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Antígenos CD4/genética , Antígenos CD4/imunologia , Vacinas Anticâncer/imunologia , Vacinas Anticâncer/uso terapêutico , Feminino , Memória Imunológica , Injeções Intralesionais , Injeções Subcutâneas , Interleucina-2/genética , Células Matadoras Naturais/imunologia , Depleção Linfocítica , Melanoma Experimental/genética , Melanoma Experimental/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Comunicação Parácrina , Neoplasias Cutâneas/imunologia , Neoplasias Cutâneas/terapia , Subpopulações de Linfócitos T/imunologia , Transdução Genética
8.
Commun Dis Public Health ; 3(1): 43-5, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10743318

RESUMO

Interviews with four apparently sporadic cases of legionnaires' disease identified by laboratory reporting in one health district revealed that three of the four cases had been exposed to a new design of spa pool on display at a retail outlet. The fourth case had been exposed to the same design of spa pool in a private home. None had bathed in the spa pool. Legionella pneumophila serogroup 1 mAB subgroup 'Philadelphia' was isolated from samples taken from both spa pools. The display pool had not been maintained as recommended for a public spa pool in use by bathers. Revised maintenance instructions were issued to all purchasers of these spa pools in the United Kingdom (UK) and overseas. Patients may not remember specific exposures; scrutiny of activity diaries helped to identify exposure to a common location. Even when not in use by bathers, spa pools on display can be a source of legionella infection and should be maintained according to current hygiene guidelines.


Assuntos
Hidroterapia , Legionella pneumophila/isolamento & purificação , Doença dos Legionários/transmissão , Biofilmes , Surtos de Doenças , Humanos , Legionella pneumophila/classificação , Doença dos Legionários/epidemiologia , Doença dos Legionários/microbiologia , Doença dos Legionários/prevenção & controle , Reino Unido/epidemiologia , Microbiologia da Água
9.
Vaccine ; 17(7-8): 904-14, 1999 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-10067697

RESUMO

This phase I clinical trial was designed to determine the feasibility of using rBCG as a live bacterial vaccine vector for the outer surface protein A (OspA) of Borrelia burgdorferi and as model for other vaccines based on a rBCG vector. To construct the vaccine, a signal peptide derived from a mycobacterial lipoprotein was used to direct the export, and membrane-associated surface expression, of OspA in a standard strain of BCG (Connaught). The rBCG OspA vaccine was safe and immunogenic in several animal species, and protective in a mouse model of Lyme borreliosis. An intradermal injection (0.1 ml) of rBCG OspA was administered to 24 healthy adult volunteers sequentially at one of four dose levels, ranging from 2.0 x 10(4) CFU to 2 x 10(7) CFU, using a dose-escalation design. All volunteers were initially PPD-skin test and OspA antibody negative, and they were monitored for 2 years after immunization. Three volunteers had mild flu-like reactions 1-2 days after vaccination. Local ulceration and drainage at the site of injection, which occurred in 50% and 83% of volunteers in the two highest dose groups, persisted for 1-70 days before the ulcers healed. Most of the drainage samples yielded rBCG colonies that contained the OspA plasmid. Thirteen of 24 vaccinees, principally in the two highest dose groups, converted their PPD skin tests from negative to positive. None of the 24 volunteers developed OspA antibody. In conclusion, the current rBCG vaccine construct, the first such construct tested in humans, had a safety profile comparable to that of licensed BCG, but it did not elicit primary humoral responses to the vectored antigen.


Assuntos
Antígenos de Superfície/efeitos adversos , Antígenos de Superfície/imunologia , Vacina BCG/efeitos adversos , Vacina BCG/imunologia , Proteínas da Membrana Bacteriana Externa/efeitos adversos , Proteínas da Membrana Bacteriana Externa/imunologia , Grupo Borrelia Burgdorferi/imunologia , Lipoproteínas , Doença de Lyme/prevenção & controle , Vacinas Sintéticas/efeitos adversos , Vacinas Sintéticas/imunologia , Adolescente , Adulto , Animais , Antígenos de Superfície/genética , Vacina BCG/genética , Proteínas da Membrana Bacteriana Externa/genética , Vacinas Bacterianas , Grupo Borrelia Burgdorferi/crescimento & desenvolvimento , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Camundongos , Teste Tuberculínico , Vacinas Sintéticas/genética
10.
Neuroradiology ; 41(1): 35-9, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9987766

RESUMO

We report an intracranial leiomyosarcoma in the pontine cistern of a 34-year-old woman infected with the human immunodeficiency virus (HIV). The clinical, radiological and pathological data are reviewed. The tumor was Epstein-Barr virus (EBV) positive by in situ hybridization. This case emphasizes that smooth muscle neoplasms arising in the setting of immunocompromise can occur intracranially, and corroborates a hypothesis that EBV coinfection may have a role in development of these tumors.


Assuntos
Síndrome da Imunodeficiência Adquirida/complicações , Neoplasias Encefálicas/complicações , Leiomiossarcoma/complicações , Adulto , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/virologia , Infecções por Vírus Epstein-Barr/complicações , Feminino , Herpesvirus Humano 4/isolamento & purificação , Humanos , Leiomiossarcoma/diagnóstico , Leiomiossarcoma/patologia , Leiomiossarcoma/virologia , Imageamento por Ressonância Magnética , Tomografia Computadorizada por Raios X
11.
Cancer Res ; 58(13): 2784-92, 1998 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-9661892

RESUMO

The novel aminosterol, squalamine, inhibits angiogenesis and tumor growth in multiple animal models. This effect is mediated, at least in part, by blocking mitogen-induced proliferation and migration of endothelial cells, thus preventing neovascularization of the tumor. Squalamine has no observable effect on unstimulated endothelial cells, is not directly cytotoxic to tumor cells, does not alter mitogen production by tumor cells, and has no obvious effects on the growth of newborn vertebrates. Squalamine was also found to have remarkable effects on the primitive vascular bed of the chick chorioallantoic membrane, which has striking similarities to tumor capillaries. Squalamine may thus be well suited for treatment of tumors and other diseases characterized by neovascularization in humans.


Assuntos
Anticarcinógenos/farmacologia , Neovascularização Fisiológica/efeitos dos fármacos , Animais , Divisão Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Embrião de Galinha/efeitos dos fármacos , Colestanóis/farmacologia , Colágeno , Córnea , Neovascularização da Córnea/prevenção & controle , Combinação de Medicamentos , Fatores de Crescimento Endotelial/metabolismo , Fatores de Crescimento Endotelial/farmacologia , Endotélio Vascular/efeitos dos fármacos , Neoplasias Oculares/prevenção & controle , Fator 2 de Crescimento de Fibroblastos/farmacologia , Glioma/tratamento farmacológico , Glioma/patologia , Laminina , Linfocinas/efeitos dos fármacos , Linfocinas/metabolismo , Linfocinas/farmacologia , Camundongos , Camundongos Endogâmicos BALB C , Fator de Crescimento Derivado de Plaquetas/farmacologia , Proteoglicanas , Coelhos , Ratos , Ratos Endogâmicos F344 , Transplante Heterólogo , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio Vascular
12.
Cancer Res ; 58(4): 672-84, 1998 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-9485020

RESUMO

Polymeric interstitial chemotherapy increases survival of humans with recurrent gliomas and animals with transplanted tumors in the brain, but the relationship between rates of drug release from polymer implants and drug concentration in brain tissue is unknown. This work presents a pharmacokinetic framework for application of this new modality of chemotherapy delivery in primates. Either [3H]carmustine, 4-hydroperoxycyclophosphamide (4-HC), or paclitaxel was encapsulated in a polyanhydride pellet (28-41 microCi/animal, 40 mg/animal), which was implanted intracranially in cynomolgus monkeys (Macaca fascicularis); (n = 17) for up to 30 days. Drug concentrations in the brain, blood, and cerebrospinal fluid were measured by quantitative autoradiography, TLC, and scintillation counting. High drug concentrations (0.5-3.5 mM for carmustine, 0.3-0.4 mM for 4-HC, and 0.2-1.0 mM for paclitaxel) were measured within the first 3 mm from the polymer implant; significant (0.4 microM for carmustine, 3 microM for 4-HC, and 0.6 microM for paclitaxel) concentrations were measured up to approximately 5 cm from the implant as long as 30 days after implantation. Pharmacokinetic analysis indicated that tissue exposure to carmustine area under concentration-time curve achieved by polymeric delivery was 4-1200 times higher than that produced by i.v. administration of a higher dose.


Assuntos
Antineoplásicos/farmacocinética , Encéfalo , Carmustina/farmacocinética , Ciclofosfamida/análogos & derivados , Implantes de Medicamento , Paclitaxel/farmacocinética , Animais , Antineoplásicos/administração & dosagem , Biodegradação Ambiental , Cápsulas , Carmustina/administração & dosagem , Ciclofosfamida/administração & dosagem , Ciclofosfamida/farmacocinética , Macaca fascicularis , Masculino , Paclitaxel/administração & dosagem , Polímeros
13.
Neurosurgery ; 41(2): 453-60; discussion 460-1, 1997 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9257314

RESUMO

OBJECTIVE: The exposure of large intracranial arteries to blood after an aneurysmal subarachnoid hemorrhage leads to a cascade of morphological and physiological changes in the vessels, a condition generally described as vasospasm. This response to the periadventitial deposition of blood is mediated in part by the endothelial layer of the vessel. This study was undertaken to examine the role of endothelial cell expression of intercellular adhesion molecule 1 (ICAM-1) in the initiation and regulation of this response. METHODS: The femoral artery model of vasospasm was used in rats (65 animals, 130 arteries). In each rat, one artery was exposed to blood and the contralateral vessel was exposed to saline, so that each animal served as its own control. Animals were perfused and killed at sequential time points, from 1 hour to 20 days after blood exposure. The vessels were examined immunohistochemically and histologically for the presence of ICAM-1 and morphological features of vasospasm, respectively. RESULTS: Endothelial cell ICAM-1 immunoreactivity was extensively increased in only the blood-exposed vessels, beginning 3 hours after clot placement and persisting for 24 hours. ICAM-1 immunoreactivity returned to baseline by 48 hours after blood exposure. The influx of inflammatory cells correlated directly with the time and location of increased ICAM-1 expression. Peak arterial remodeling was observed on the blood-exposed side 8 to 12 days after clot placement, as quantified by measurements of increased wall thickness, decreased lumen size, and increased collagen content. CONCLUSION: Endothelial cell ICAM-1 expression seems to be an early and specific signal used by a vessel in response to the deposition of blood periadventitially. This molecule may be a marker for vessels likely to undergo subsequent morphological remodeling and vasospasm.


Assuntos
Endotélio Vascular/metabolismo , Artéria Femoral , Hemorragia/fisiopatologia , Molécula 1 de Adesão Intercelular/metabolismo , Vasoconstrição , Animais , Arterite/patologia , Movimento Celular , Endotélio Vascular/patologia , Artéria Femoral/metabolismo , Artéria Femoral/patologia , Artéria Femoral/fisiopatologia , Imuno-Histoquímica , Ratos , Ratos Endogâmicos F344
15.
J Appl Physiol (1985) ; 71(6): 2168-72, 1991 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1778908

RESUMO

Studies were performed to determine the pH relationships among the extracellular, intracellular, and arterial blood compartments in the brain in vivo. Resolution of the extracellular monophosphate resonance peak from the intracellular peak in 31P nuclear magnetic resonance (NMR) spectra of sheep brain with the calvarium intact enabled pH measurement in these respective compartments. Sheep were then subjected to both hyper- and hypoventilation, which resulted in a wide range of arterial PCO2 and pH values. Linear regression analysis of pH in these compartments yielded slopes of 0.56 +/- 0.05 for extracellular pH (pHe) vs. arterial pH, 0.43 +/- 0.078 for intracellular pH (pHi) vs. pHe, and 0.23 +/- 0.056 for pHi vs. arterial pH. These data indicate that CO2 buffering capacity is different and decreases from the intracellular to extracellular to arterial blood compartments. Separation of the extracellular space from the vascular space may be a function of the blood-brain barrier, which contributes to the buffering capability of the extracellular compartment. A marked decrease in the pH gradient between the extracellular and intracellular space occurs during hypercarbia and may influence mechanisms of central respiratory control.


Assuntos
Encéfalo/metabolismo , Hipercapnia/metabolismo , Hipocapnia/metabolismo , Animais , Espaço Extracelular/metabolismo , Concentração de Íons de Hidrogênio , Líquido Intracelular/metabolismo , Espectroscopia de Ressonância Magnética , Ovinos
16.
J Neurosurg ; 74(6): 956-61, 1991 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-2033457

RESUMO

Controlled-release polymers have facilitated the interstitial delivery of drugs within the central nervous system. In the present study, dexamethasone was incorporated into ethylene-vinyl acetate polymers, which were then implanted adjacent to a 9L gliosarcoma in the brain of Fischer 344 rats. The effect of interstitial delivery of dexamethasone on peritumoral edema was assessed and compared to the effect of dexamethasone delivered systemically. Eighty-five rats underwent intracranial implantation of the 9L gliosarcoma. Five days later, the animals were randomly assigned to one of four treatment groups: Group 1 received intracranial implantation of controlled-release polymers containing dexamethasone; Group 2 received intraperitoneal implantation of controlled-release polymers containing dexamethasone; Group 3 received serial intraperitoneal injections of dexamethasone; and Group 4 received sham treatment. The animals were sacrificed 3 days after initiation of therapy and their brains were removed for measurement of the water content (edema) in the tumor-bearing and contralateral hemispheres. Brain and plasma samples were analyzed by reverse-phase high-performance liquid chromatography to determine the tissue and plasma concentrations of dexamethasone. Measurement of the release kinetics of dexamethasone from the ethylene-vinyl acetate polymers in an in vitro system showed that the drug was released in a controlled, tapering fashion. During the first 3 days of controlled release in vitro, 330 micrograms of a total content of 7.5 mg of dexamethasone was released into the medium. Analysis of tissue for drug levels demonstrated, however, that the interstitial delivery of this fractional amount of dexamethasone within the brain resulted in levels 19 times higher than those achieved by administering the full dose of 7.5 mg systemically over a 3-day period. Conversely, the systemic administration of dexamethasone resulted in plasma levels 16 times higher than those measured in the interstitial delivery of dexamethasone in the brain. Brain-water content determinations showed that the interstitial controlled release of the fractional amount of dexamethasone within the brain was as effective in controlling peritumoral edema as systemic administration of the full dose by serial intraperitoneal injections. The study demonstrates the following: 1) controlled-release polymeric carriers deliver biologically active dexamethasone in a sustained fashion; 2) very high concentrations of dexamethasone in brain tissue can be achieved using interstitial polymer-mediated drug delivery while minimizing plasma concentrations of this drug which are sometimes associated with serious systemic side effects; and 3) peritumoral brain edema can be effectively treated by the interstitial delivery of dexamethasone directly within the tumor bed.


Assuntos
Edema Encefálico/prevenção & controle , Neoplasias Encefálicas/complicações , Dexametasona/administração & dosagem , Animais , Água Corporal/efeitos dos fármacos , Química Encefálica , Edema Encefálico/etiologia , Cromatografia Líquida de Alta Pressão , Preparações de Ação Retardada , Dexametasona/farmacocinética , Implantes de Medicamento , Masculino , Ratos , Ratos Endogâmicos F344
19.
Appl Environ Microbiol ; 48(4): 813-7, 1984 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-6508289

RESUMO

An enrichment procedure after ethyl methanesulfonate mutagenesis and exposure to the fungicide benomyl yielded mutants auxotrophic for several amino acids from two polyploid Saccharomyces spp. Benomyl treatment was found to have a marked morphological effect on polyploid Saccharomyces cerevisiae, causing cells to adopt a characteristic doublet cell morphology in which buds are nearly as large as the parent cells. Experiments in which nuclear division was monitored in benomyl-induced doublet cells by Giemsa nuclear staining demonstrated an unusual sequence of cytological events which culminated in the formation of binucleate parental and mononucleate bud components. The frequency of formation of doublet and binucleate parent cells was found to depend on the strain employed and the benomyl concentration administered.


Assuntos
Benomilo/farmacologia , Carbamatos/farmacologia , Saccharomyces/efeitos dos fármacos , Benzimidazóis/farmacologia , Divisão Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Mutação , Poliploidia , Saccharomyces/citologia , Saccharomyces/genética
20.
Laryngoscope ; 89(4): 646-54, 1979 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-431264

RESUMO

The usefulness of rotatory testing (impulsive and sinusoidal) as an indicator of impaired horizontal semicircular canal function was evaluated in 63 patients with unilateral and bilateral decreased caloric responses. The rotatory stimuli were precisely controlled over a large magnitude range and EOG recorded nystagmus responses were quantified using digital analysis techniques. Rotatory testing was consistently abnormal in patients with complete unilateral caloric paralyses but was normal in over one-half of the patients with significant but less than complete unilateral caloric paralyses. The difference in maximum slow component velocity (SVMX) of induced nystagmus after the largest rotatory stimuli was the best indicator of unilateral impaired function. The patients with bilateral decreased caloric responses demonstrated three categories of rotatory response: 1. normal at all magnitudes of stimulation, 2. decreased but present after large magnitude stimuli, and 3. absent responses. It is concluded that although rotatory testing cannot replace caloric testing it can provide useful clinical information particularly in patients suspected of having bilateral vestibular disease.


Assuntos
Canais Semicirculares/fisiopatologia , Testes de Função Vestibular , Testes Calóricos , Eletroculografia , Movimentos Oculares , Humanos
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