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1.
Osteoarthritis Cartilage ; 23(4): 661-70, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25600960

RESUMO

OBJECTIVE: To investigate the in vivo role of the IRE1/XBP1 unfolded protein response (UPR) signaling pathway in cartilage. DESIGN: Xbp1(flox/flox).Col2a1-Cre mice (Xbp1(CartΔEx2)), in which XBP1 activity is ablated specifically from cartilage, were analyzed histomorphometrically by Alizarin red/Alcian blue skeletal preparations and X-rays to examine overall bone growth, histological stains to measure growth plate zone length, chondrocyte organization, and mineralization, and immunofluorescence for collagen II, collagen X, and IHH. Bromodeoxyuridine (BrdU) and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) analyses were used to measure chondrocyte proliferation and cell death, respectively. Chondrocyte cultures and microdissected growth plate zones were analyzed for expression profiling of chondrocyte proliferation or endoplasmic reticulum (ER) stress markers by Quantitative PCR (qPCR), and of Xbp1 mRNA splicing by RT-PCR to monitor IRE1 activation. RESULTS: Xbp1(CartΔEx2) displayed a chondrodysplasia involving dysregulated chondrocyte proliferation, growth plate hypertrophic zone shortening, and IRE1 hyperactivation in chondrocytes. Deposition of collagens II and X in the Xbp1(CartΔEx2) growth plate cartilage indicated that XBP1 is not required for matrix protein deposition or chondrocyte hypertrophy. Analyses of mid-gestation long bones revealed delayed ossification in Xbp1(CartΔEx2) embryos. The rate of chondrocyte cell death was not significantly altered, and only minimal alterations in the expression of key markers of chondrocyte proliferation were observed in the Xbp1(CartΔEx2) growth plate. IRE1 hyperactivation occurred in Xbp1(CartΔEx2) chondrocytes but was not sufficient to induce regulated IRE1-dependent decay (RIDD) or a classical UPR. CONCLUSION: Our work suggests roles for XBP1 in regulating chondrocyte proliferation and the timing of mineralization during endochondral ossification, findings which have implications for both skeletal development and disease.


Assuntos
Calcificação Fisiológica/fisiologia , Cartilagem Articular/patologia , Condrócitos/patologia , Proteínas de Ligação a DNA/genética , Deleção de Genes , Osteocondrodisplasias/patologia , Transdução de Sinais/fisiologia , Fatores de Transcrição/genética , Animais , Apoptose/fisiologia , Cartilagem Articular/fisiopatologia , Proliferação de Células/fisiologia , Proteínas de Ligação a DNA/fisiologia , Modelos Animais de Doenças , Estresse do Retículo Endoplasmático/fisiologia , Lâmina de Crescimento/patologia , Lâmina de Crescimento/fisiopatologia , Proteínas de Membrana/genética , Proteínas de Membrana/fisiologia , Camundongos , Camundongos Transgênicos , Osteocondrodisplasias/fisiopatologia , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/fisiologia , Fatores de Transcrição de Fator Regulador X , Transdução de Sinais/genética , Fatores de Transcrição/fisiologia , Proteína 1 de Ligação a X-Box
2.
Br J Cancer ; 93(1): 98-106, 2005 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-15970923

RESUMO

The vascular effects of the endothelin B (ET(B)) receptor agonist IRL 1620 were investigated in the rat P22 carcinosarcoma and a range of normal tissues in BDIX rats. Tissue blood flow rate was calculated from measurements of tissue uptake of radiolabelled iodoantipyrine. A comparison of vascular effects in the P22 tumour and the HSN sarcoma growing in CBH/CBi rats was made using laser Doppler flowmetry, showing similar effects of IRL 1620, with red cell flux rapidly decreasing by 50-60% and then returning to control levels within approximately 30 min. This corresponded to similar levels but different spatial organisation of ET(B) binding sites in the two tumours, as measured by autoradiography. The decrease in tumour blood flow and an increase in vascular resistance suggest that the vascular component of ET(B) receptors in the P22 tumour is localised on contractile elements rather than on endothelial cells. ET(A) receptors were also identified. Vasoconstriction occurred uniformly throughout the P22 tumour mass, consistent with a measured homogeneous distribution of ET(B) receptors. IRL 1620 caused vasoconstriction in normal skeletal muscle, kidney and small intestine of the BDIX rat as well as in tumour, but did not affect blood flow in other tissues. These effects could be useful for limiting toxicity of certain chemotherapeutic agents. Fully functional ET(B) receptors are clearly expressed on tumour vasculature and IRL 1620 shows promise for short-term modification of tumour blood flow. Expression levels of ET(B) receptors on the tumour vasculature could be useful for predicting which tumours are likely to respond to IRL 1620.


Assuntos
Carcinossarcoma/irrigação sanguínea , Endotelinas/farmacologia , Fragmentos de Peptídeos/farmacologia , Receptor de Endotelina B/agonistas , Vasoconstritores/farmacologia , Animais , Pressão Sanguínea , Carcinossarcoma/patologia , Frequência Cardíaca , Masculino , Ratos , Resistência Vascular
3.
Int Orthop ; 29(3): 160-3, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15864590

RESUMO

The aim of this prospective study was to determine the effect of screening for methicillin-resistant Staphylococcus aureus (MRSA), in patients undergoing total hip and knee replacements, on reducing hospital-acquired infections and the length of hospital stay. We included 395 patients admitted to the elective orthopaedic ward for hip and knee replacements (knee 210; hip 185) from 16 October 2000 to 15 October 2001. Group 1 included 164 admissions before 16 April 2001 when MRSA swabs were not compulsory. Group 2 included 231 admissions after 16 April 2001 when axillary, nasal and groin swabs had to be negative for MRSA. Four patients in group 1 had post-operative MRSA infection compared with none in group 2. The mean length of hospital stay decreased significantly from 10.43 days +/- SD 4.2 days in group 1 to 9.47 days +/- SD 2.6 days in group 2. There was a significant reduction in the incidence of hospital-acquired infections following the introduction of pre-admission screening.


Assuntos
Artroplastia de Substituição , Programas de Rastreamento/métodos , Resistência a Meticilina , Infecções Estafilocócicas/diagnóstico , Staphylococcus aureus/isolamento & purificação , Idoso , Infecção Hospitalar/prevenção & controle , Feminino , Humanos , Tempo de Internação , Masculino , Técnicas Microbiológicas , Pessoa de Meia-Idade , Isolamento de Pacientes , Estudos Prospectivos , Resultado do Tratamento
4.
Hum Genet ; 106(3): 269-76, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10798354

RESUMO

Members of the SOX gene family encode proteins with homology to the HMG box DNA-binding domain of SRY, the Y-linked testis-determining gene. SOX genes are expressed during embryogenesis and are involved in the development of a wide range of different tissues. Mutations in SRY, SOX9 and SOX10 have been shown to be responsible for XY sex reversal, campomelic dysplasia and Waardenburg-Hirschsprung disease, respectively. It is likely that mutations in other SOX genes are responsible for a variety of human genetic diseases. SOX14 has been identified from a human genomic library and the mouse and chicken sequences obtained by polymerase chain reaction amplification. The SOX14 amino acid sequence is highly conserved across these species, suggesting an important role for this protein in vertebrate development. SOX14 is expressed in the neural tube and apical ectodermal ridge of the developing chicken limb. This is the only SOX gene known to be expressed in the apical ectodermal ridge, a structure that directs outgrowth of the embryonic limb bud. Human SOX14 is localised to a 1.15-Mb yeast artificial chromosome on chromosome 3q23, close to loci for BPES (blepharophimosis, ptosis, epicanthus inversus syndrome) and Mobius syndrome. Although SOX14 maps outside these loci, its expression pattern and chromosomal localisation suggest that it is a candidate gene for the limb defects frequently associated with these syndromes.


Assuntos
Blefarofimose/genética , Blefaroptose/genética , Proteínas de Grupo de Alta Mobilidade/genética , Deformidades Congênitas dos Membros/genética , Síndrome de Möbius/genética , Sequência de Aminoácidos , Animais , Embrião de Galinha , Mapeamento Cromossômico , Cromossomos Artificiais de Levedura , Cromossomos Humanos Par 3 , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Hibridização In Situ , Masculino , Camundongos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Fatores de Transcrição SOXB2 , Homologia de Sequência de Aminoácidos
5.
Int J Cancer ; 80(2): 295-302, 1999 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-9935213

RESUMO

Activation of endothelin receptors on the vasculature can produce a variety of responses from potent vasoconstriction to mild vasodilation, depending on the receptor complement within the tissue. To elucidate the potential role of endothelin analogues as tumour blood flow modifiers, we have evaluated the effect of the ET(B) receptor agonist, IRL 1620 ([Suc-(Glu9, Ala(11,15))-ET-1(8-21)]) in CBH/CBi rats bearing an HSN fibrosarcoma. Tissue blood flow and vascular resistance were determined, 20 min following administration of IRL 1620 (bolus intravenous), using the uptake of radiolabelled iodoantipyrine (125I-IAP). Blood flow was unchanged in most tissues. However, at doses > or = 1.0 nmol kg(-1) IRL 1620, blood flow in the brain and heart was increased, whereas in the small intestine it was reduced. Blood flow in the skeletal muscle was reduced at 1.0 nmol kg(-1) only. Tumour blood flow was significantly reduced at 3.0 and 5.0 nmol kg(-1). Vascular resistance was unchanged in most tissues although it was increased in the skeletal muscle at 1.0 nmol kg(-1), in the kidney at 1.0 and 3.0 nmol kg(-1) and in the brain and heart, it was reduced at 5.0 nmol kg(-1) IRL 1620. Vascular resistance was significantly increased in the tumour and the small intestine at doses > or = 1 nmol kg(-1) IRL 1620. Pretreatment of rats with BQ-788, an ET(B) receptor antagonist, selectively attenuated the tumour vascular response to 3 nmol kg(-1) IRL 1620 with no changes observed in the normal tissue responses. Our results demonstrate that the HSN tumour vasculature is selectively responsive to IRL 1620 at doses > 1 nmol kg(-1) compared with the majority of normal tissues with the exception of the small intestine, and that only the tumour response is highly sensitive to BQ-788 antagonism, under the experimental dosing regime investigated. These differences may be exploitable for therapeutic benefit.


Assuntos
Endotelinas/farmacologia , Fibrossarcoma/tratamento farmacológico , Fragmentos de Peptídeos/farmacologia , Receptores de Endotelina/agonistas , Análise de Variância , Animais , Antipirina/análogos & derivados , Antipirina/metabolismo , Pressão Sanguínea/efeitos dos fármacos , Fibrossarcoma/irrigação sanguínea , Frequência Cardíaca/efeitos dos fármacos , Oligopeptídeos/farmacologia , Piperidinas/farmacologia , Ratos , Ratos Endogâmicos , Valores de Referência , Fluxo Sanguíneo Regional , Resistência Vascular/efeitos dos fármacos
6.
Can J Physiol Pharmacol ; 76(3): 325-33, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9673796

RESUMO

The opioid binding profile and in vitro activity of the endogenous opioid peptide dynorphin A(1-8) have been studied. At opioid receptors in guinea-pig brain dynorphine A(1-8) was nonselective, although with some preference for the delta receptor (Ki 4.6 nM) over mu (Ki 18 nM) and kappa (Ki 40 nM) receptors. However, a high degree of metabolism was observed, with less than 10% of added dynorphin A(1-8) remaining at the end of the binding assay. In the presence of peptidase inhibitors to prevent breakdown of the N- and C-termini and the Gly3-Phe4 bond the major metabolite was [Leu5]enkephalin (representing 49% recovered material). This was reduced by inclusion of an inhibitor of endopeptidase EC 3.4.24.15. In the presence of all the peptidase inhibitors the affinity for kappa receptors (Ki 0.5 nM) relative to mu and delta receptors increased, but no selectivity of binding was observed. This lack of selectivity was confirmed using membranes from C6 glioma cells expressing rat opioid receptors. The agonist effect of dynorphin A(1-8) in the mouse vas deferens (EC50 116 nM) and guinea-pig ileum (EC50 38 nM) was mediated through the kappa receptor as evidenced by the rightward shifts afforded by the kappa-selective antagonist norbinaltorphimine. In the presence of peptidase inhibition potency was improved 2-fold in the mouse vas deferens and 20-fold in the guinea-pig ileum, but this agonist activity was mediated through delta receptors in the vas deferens and mu receptors in the ileum, as a result of the formation and stabilization of [Leu5]enkephalin. The results confirm the absence of receptor selectivity of dynorphin A(1-8) in binding assays but show that its agonist effects, at least in vitro, are mediated exclusively through the kappa opioid receptor.


Assuntos
Dinorfinas/metabolismo , Peptídeos Opioides/metabolismo , Fragmentos de Peptídeos/metabolismo , Receptores Opioides kappa/metabolismo , Animais , Ligação Competitiva , Estabilidade de Medicamentos , Encefalinas/metabolismo , Cobaias , Masculino , Camundongos , Músculos/efeitos dos fármacos , Músculos/metabolismo , Plexo Mientérico/efeitos dos fármacos , Plexo Mientérico/metabolismo , Ratos , Receptores Opioides kappa/agonistas , Células Tumorais Cultivadas , Ducto Deferente/efeitos dos fármacos , Ducto Deferente/metabolismo
7.
Semin Radiat Oncol ; 8(3): 151-63, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9634492

RESUMO

Suboptimal drug distribution and hypoxia, which can contribute to treatment failure, are a direct consequence of the spatial and temporal heterogeneity in perfusion that occurs in solid tumors. Therefore, improvements in tumor blood flow have wide-ranging therapeutic importance. Paradoxically, controlled decreases in tumor blood flow can also be exploited and, if permanent, induce extensive tumor cell death on their own. We review the current knowledge of the factors controlling tumor blood flow with emphasis on the roles of the endogeneous vasodilator nitric oxide and the endogenous vasoconstrictor endothelin-1. The potential importance and application of approaches that irreversibly damage vascular function, so-called vascular targeting, are also discussed. Emphasis is given to the drug-based approaches to vascular targeting that are now entering clinical evaluation. There is no doubt that increased understanding of the processes that determine blood flow in tumors, coupled with the availability of techniques to monitor blood flow noninvasively in the clinic, will enable strategies for selectively modifying tumor blood flow to be transferred from the laboratory to the clinical setting.


Assuntos
Neoplasias/irrigação sanguínea , Antineoplásicos/farmacocinética , Vasos Sanguíneos/efeitos dos fármacos , Morte Celular , Hipóxia Celular , Endotelina-1/fisiologia , Humanos , Neoplasias/tratamento farmacológico , Óxido Nítrico/fisiologia , Fluxo Sanguíneo Regional/fisiologia , Distribuição Tecidual , Falha de Tratamento , Vasoconstritores/farmacologia , Vasodilatadores/farmacologia
8.
J Cardiovasc Pharmacol ; 31 Suppl 1: S537-40, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9595536

RESUMO

Endothelin-1 (ET-1) is produced by some tumor cells, but the dependence of this production on pO2 and pCO2, conditions relevant within the tumor microenvironment, has not been described. HT29 colon adenocarcinoma cells and DU145 prostate carcinoma cells produce similar amounts of ET-1 in vitro under normal cell culture conditions of 21% O2/5% CO2 (normoxia). Exposure of HT29 cells to either 2% O2 or 0.2% O2 significantly reduced ET-1 production compared to cells in normoxia. In contrast, production of ET-1 by DU145 cells was usually unaffected by hypoxia and was even slightly increased in cells exposed to 2% O2 in HEPES-buffered EMEM (HEPES-EMEM). Exposure of cells to either 2.2% CO2 or 7.1% CO2 had no effect on the production of ET-1 by cells in bicarbonate-buffered EMEM (EMEM). However, in HEPES-EMEM, ET-1 production by both cell lines was reduced in 7.1% CO2. A slight reduction in ET-1 produced by DU145 cells was also observed in 2.2% CO2. These results illustrate that changes in ET-1 production by tumor cells in response to hypoxia and hypercapnia are tumor-dependent. It is clear that the production of ET-1 by tumor cells under normal culture conditions may not accurately reflect production within the tumor microenvironment. A greater insight into the in vivo situation, however, may be possible by modifying the cell culture conditions.


Assuntos
Dióxido de Carbono/farmacologia , Endotelina-1/biossíntese , Oxigênio/farmacologia , Adenocarcinoma/metabolismo , Neoplasias do Colo/metabolismo , Células HT29/metabolismo , Humanos , Células Tumorais Cultivadas
9.
Hum Mutat ; 11(4): 340-2, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9554756

RESUMO

Kallmann syndrome is an inherited disease which is characterised by anosmia (inability to smell) and hypogonadotropic hypogonadism both of which are thought to occur as a result of a failure of correct neuronal migration. To date the only genetic lesions identified are mutations in the X-linked gene, KAL. We conducted a mutation screen of the KAL gene in a family with Kallmann syndrome. This identified a new mutation in the KAL gene which removed an acceptor site at the junction of exon 6/intron 5. Exon 6 of the KAL gene encodes the C-terminal portion of a fibronectin type III domain may be involved in axonal pathfinding. We presume that the described mutation would result in the removal of exon 6 resulting in a frame shift which terminates the protein prematurely. It has been proposed that both mental illness and vesico-ureteric reflux are associated with mutations in the KAL gene. However, results from the family presented here do not show an association between either trait and the KAL gene mutation.


Assuntos
Proteínas da Matriz Extracelular , Síndrome de Kallmann/genética , Mutação , Proteínas do Tecido Nervoso/genética , Criança , Éxons , Feminino , Humanos , Masculino , Transtornos Mentais/genética , Linhagem , Fenótipo , Splicing de RNA/genética , Refluxo Vesicoureteral/genética
10.
Int J Cancer ; 73(2): 283-9, 1997 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-9335456

RESUMO

Modification of blood flow by endothelin-1 (ET-1) was examined in the s.c. HSN fibrosarcoma and compared to normal tissues of anaesthetised CBH/CBi rats. The ET receptor subtypes involved in the response were investigated using the ET(A) and ET(B) receptor antagonists BQ-610 and BQ-788, respectively. Blood flow and vascular resistance were determined using the uptake of radiolabelled iodo-antipyrine (125I-IAP). BQ-610 or BQ-788 was infused for 30 min prior to blood flow determination. ET-1 was administered 15 min into the infusion time. BQ-610 and BQ-788 infused alone did not modify any vascular parameters. Tumour blood flow increased slightly following ET-1, contrasting with most normal tissues, in which blood flow was reduced. Vascular resistance increased in all tissues, including the tumour. Neither antagonist significantly modified the ET-1-induced changes in tumour blood flow or vascular resistance, whereas in the majority of normal tissues BQ-610 attenuated and BQ-788 potentiated the vascular resonse to ET-1. Our results show that the HSN tumour vasculature is only weakly responsive to ET- 1 and antagonism of its effects by BQ-610 and BQ-788. This contrasts with the majority of normal tissues, in which ET- 1 induces an intense vasoconstriction.


Assuntos
Antagonistas dos Receptores de Endotelina , Endotelina-1/farmacologia , Fibrossarcoma/irrigação sanguínea , Hemodinâmica/efeitos dos fármacos , Neoplasias Experimentais/irrigação sanguínea , Animais , Velocidade do Fluxo Sanguíneo/efeitos dos fármacos , Pressão Sanguínea/efeitos dos fármacos , Feminino , Fibrossarcoma/tratamento farmacológico , Frequência Cardíaca/efeitos dos fármacos , Neoplasias Experimentais/tratamento farmacológico , Oligopeptídeos/farmacologia , Piperidinas/farmacologia , Ratos , Receptor de Endotelina A , Receptor de Endotelina B , Resistência Vascular/efeitos dos fármacos
11.
Br J Cancer ; 74(12): 1955-60, 1996 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8980396

RESUMO

The effect of nitric oxide-dependent vasodilators on vascular resistance of tumours and normal tissue was determined with the aim of modifying tumour blood flow for therapeutic benefit. Isolated preparations of the rat P22 tumour and normal rat hindlimb were perfused ex vivo. The effects on tissue vascular resistance of administration of sodium nitroprusside (SNP) and the diazeniumdiolate (or NONO-ate) NOC-7, vasodilators which act via direct release of nitric oxide (NO), were compared with the effects of acetylcholine (ACh), a vasodilator which acts primarily via receptor stimulation of endothelial cells to release NO in the form of endothelium-derived relaxing factor (EDRF). SNP and NOC-7 effectively dilated tumour blood vessels after preconstriction with phenylephrine (PE) or potassium chloride (KCl) as indicated by a decrease in vascular resistance. SNP also effectively dilated normal rat hindlimb vessels after PE/KCl constriction. Vasodilatation in the tumour preparations was accompanied by a significant rise in nitrite levels measured in the tumour effluent. ACh induced a significant vasodilation in the normal hindlimb but an anomalous vasoconstriction in the tumour. This result suggests that tumours, unlike normal tissues are incapable of releasing NO (EDRF) in response to ACh. Capacity for EDRF production may represent a difference between tumour and normal tissue blood vessels, which could be exploited for selective pharmacological manipulation of tumour blood flow.


Assuntos
Carcinossarcoma/irrigação sanguínea , Óxido Nítrico/biossíntese , Óxido Nítrico/fisiologia , Vasodilatação/fisiologia , Acetilcolina/fisiologia , Animais , Carcinossarcoma/metabolismo , Membro Posterior/irrigação sanguínea , Membro Posterior/efeitos dos fármacos , Masculino , Neoplasias Experimentais/metabolismo , Nitratos/análise , Nitritos/análise , Nitroprussiato/farmacologia , Perfusão , Ratos , Resistência Vascular/efeitos dos fármacos , Resistência Vascular/fisiologia , Vasodilatação/efeitos dos fármacos
12.
Int J Cancer ; 67(5): 730-8, 1996 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-8782666

RESUMO

Tumour blood flow modification following i.v. administration of angiotensin II (AT II, 0.19 nmol kg-1 min-1) or endothelin-1 (ET-1, 1 nmol kg-1) was compared in the P22 carcinosarcoma-bearing BD9 rat and the HSN fibrosarcoma-bearing CBH/CBi rat using the tissue uptake of radiolabelled iodoantipyrine. Results were compared with a range of normal tissues. HSN tumour blood flow was unmodified by either peptide, whereas P22 tumour blood flow was unmodified by ET-1 but was reduced to 80% of the control flow by AT II. Both peptides reduced absolute blood flow in the skin overlying the tumour, in contralateral skin, skeletal muscle, kidney and small intestine, whereas blood flow to the brain and heart was significantly increased by ET-1 and unmodified by AT II. Both peptides significantly increased vascular resistance (mean arterial blood pressure / tissue blood flow) in all normal tissues and both tumours, thus demonstrating the existence of vascular receptors for these 2 vasomodifiers, and the capacity of the vessels to respond to receptor activation. Dependency of response on tumour size was examined in the P22 tumour. In contrast to that in small P22 tumours (1.22 +/- 0.06 g), blood flow to large P22 tumours (7.18 +/- 0.25 g) was unmodified by AT II. Vascular resistance was equally increased in both tumour groups, thus illustrating little difference in the vascular response to AT II in the size range examined. Results show that the 2 rat tumours responded directly to ET-1 and AT II, but do not indicate any advantage of ET-1 over AT II in tumour blood flow modification. However, the existence of tumour vascular endothelin receptors suggests that the advent of less toxic and more controllable receptor ligands may make endothelin receptors of value in the modification of tumour blood flow.


Assuntos
Angiotensina II/farmacologia , Carcinossarcoma/irrigação sanguínea , Endotelinas/farmacologia , Fibrossarcoma/irrigação sanguínea , Animais , Velocidade do Fluxo Sanguíneo , Pressão Sanguínea , Encéfalo/irrigação sanguínea , Carcinossarcoma/patologia , Vasos Coronários/fisiologia , Fibrossarcoma/patologia , Intestino Delgado/irrigação sanguínea , Rim/irrigação sanguínea , Músculo Esquelético/irrigação sanguínea , Ratos , Pele/irrigação sanguínea , Resistência Vascular , Vasoconstrição
13.
Br J Cancer Suppl ; 27: S161-3, 1996 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8763871

RESUMO

Modification of tissue blood flow and tissue vascular resistance was examined in the female CBH rat, bearing a HSN fibrosarcoma, following bolus intravenous administration of 1 nM kg-1 endothelin-1 (ET-1) or 1 nM kg-1 sarafotoxin S6c (SX6c), selective agonists for endothelin A (ETA) and B (ETB) receptors respectively. Blood flow was measured 15 min after drug administration by the tissue uptake of 125I-labelled-iodoantipyrine. ET-1 and SX6c produced increases in mean arterial blood pressure (MABP) of 52 mmHg and 42 mmHg respectively. Blood flow to the tumour was unaffected by ET-1 treatment, whereas blood flow to normal tissues was reduced, the exception being the heart and the brain in which flow was increased. In contrast, tumour blood flow following SX6c was significantly increased, whereas blood flow in normal tissues was either unaltered or reduced. Vascular resistance was increased in all tissues and the tumour by ET-1 demonstrating that the tumour vasculature was constricting via ETA receptor activation. SX6c however, did not modify tumour vascular resistance, whereas it increased vascular resistance in all normal tissues, suggesting that the tumour lacks a functional population of ETB receptors. This discrepancy may provide a means for selectively modifying tumour blood flow.


Assuntos
Endotelina-1/farmacologia , Fibrossarcoma/irrigação sanguínea , Venenos de Víboras/farmacologia , Animais , Pressão Sanguínea/efeitos dos fármacos , Feminino , Ratos , Fluxo Sanguíneo Regional/efeitos dos fármacos , Resistência Vascular/efeitos dos fármacos
14.
Int J Cancer ; 65(5): 658-63, 1996 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-8598318

RESUMO

Angiotensin II (ATII) has potential for improving delivery of blood-borne anti-cancer agents to tumours by increasing tumour blood flow. However, ATII-induced hypertension is not always accompanied by an increase in tumour blood flow due to significant constriction of the tumour vasculature. Such unpredictability in tumour response to ATII limits the clinical usefulness of this approach. In this study, the potential of assessing numbers of binding sites for ATII as a predictor of tumour blood flow response to intravenous administration of ATII was investigated. The distribution of ATII receptors in the rat P22 carcinosarcoma was related to tumour blood flow distribution and blood flow response to ATII using an autoradiographic approach. ATII (0.2 microgram x kg-1 x min-1) increased mean arterial blood pressure of anaesthetized BD9 rats from 92.2 +/- 1.4 mmHG to 145.6+- 1.3 mmHg. Despite this increase in perfusion pressure, overall tumour blood flow to viable regions decreased by 20%, indicating significant constriction of tumour blood vessels. Autoradiographic localisation of tumour blood flow showed that the decrease in flow was confined to the tumour periphery, with no change at the tumour centre. This pattern was consistent with 10% more binding sites for ATII at the tumour periphery than at the tumour centre. Maximum number of binding sites (BLmax) for the P22 tumour was 0.38 +/- 0.09 fmol x mg-1, which is approximately a factor of 10 lower than published values for various normal tissues. The dissociation constant Kd was l.16 +/- 0.18 nM. These results encourage the development of techniques for analysis of receptor binding characteristics for predicting the response of individual tumours to blood flow manipulation using vasoactive agents.


Assuntos
Angiotensina II/farmacologia , Carcinossarcoma/irrigação sanguínea , Receptores de Angiotensina/fisiologia , Animais , Humanos , Ratos , Fluxo Sanguíneo Regional/efeitos dos fármacos , Resistência Vascular
15.
J Cardiovasc Pharmacol ; 26 Suppl 3: S222-5, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-8587370

RESUMO

The modification of tumor blood flow resulting from administration of endothelin-1 (ET-1) and sarafotoxin S6c (SX6c) was examined in female CBH rats. Blood flow in subcutaneous HSN tumors and normal tissues was measured by tissue uptake of 125I-labeled iodoantipyrine ([125I])IAP). A 75% increase in tumor blood flow was observed after 1 nM/kg ET-1, contrasting with flow in normal tissue, which was unaffected or reduced. The exception to this was the brain, in which blood flow was increased by 30%, resulting from a rise in mean arterial blood pressure (MABP) and the absence of vasoconstriction. Paradoxically, a significant drop in the tumor vascular resistance was observed after 1 nM/kg ET-1, whereas in all other tissues the vascular resistance was significantly increased. Vascular responses to SX6c differed from those observed with ET-1. At 1 nM/kg SX6c, blood flow in the tumor was increased to 175% of the control as a result of the increase in MABP, which was similar to ET-1. However, unlike ET-1, there was no associated vasodilatation. Vascular resistance was increased in all normal tissues with 1 nM/kg SX6c, corresponding to decreases in blood flow in the contralateral skin, skeletal muscle, and small intestine. This study therefore demonstrates that the vascular responses to ET-1 and SX6c are unique in the HSN tumor compared to normal tissues. This atypical response of the tumor vasculature may therefore be exploitable to improve the delivery of blood-borne anti-cancer agents in therapy.


Assuntos
Endotelinas/farmacologia , Sarcoma Experimental/irrigação sanguínea , Venenos de Víboras/farmacologia , Animais , Pressão Sanguínea/efeitos dos fármacos , Feminino , Fibrossarcoma/irrigação sanguínea , Ratos , Fluxo Sanguíneo Regional/efeitos dos fármacos , Resistência Vascular/efeitos dos fármacos
16.
Acta Oncol ; 34(3): 373-7, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-7540023

RESUMO

Acetylcholine and sodium nitroprusside, which vasodilate via release of NO by endothelium-dependent and endothelium-independent mechanisms respectively, had little effect on tumour vascular resistance when administered to tissue-isolated tumours perfused in their normal state. However, under phenylephrine-induced vasoconstriction, sodium nitroprusside induced vasodilation whilst acetylcholine induced a small vasoconstriction. Phenylephrine itself induced an oscillatory change in tumour perfusion pressure. The nitric oxide synthase (NOS) inhibitor N omega-nitro-L-arginine (L-NNA) caused a dose-dependent increase in vascular resistance in ex vivo perfused tumours which was greater than that in normal perfused hindlimbs. Systemic administration of L-NNA caused a 50% decrease in tumour blood flow which was a larger effect than in any of the normal tissues studied except spleen and skeletal muscle. Modification of NOS activity in tumours is a promising means for selective tumour blood flow modification. Investigation of endothelium-dependent versus endothelium-independent methods for modifying tumour blood flow may provide methods for further selectivity.


Assuntos
Acetilcolina/farmacologia , Carcinossarcoma/irrigação sanguínea , Endotélio Vascular/fisiopatologia , Óxido Nítrico/fisiologia , Nitroprussiato/farmacologia , Resistência Vascular/efeitos dos fármacos , Vasoconstrição/efeitos dos fármacos , Vasodilatação/efeitos dos fármacos , Aminoácido Oxirredutases/antagonistas & inibidores , Animais , Arginina/análogos & derivados , Arginina/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Relação Dose-Resposta a Droga , Endotélio Vascular/efeitos dos fármacos , Masculino , Óxido Nítrico Sintase , Nitroarginina , Fenilefrina/farmacologia , Ratos , Ratos Endogâmicos , Fluxo Sanguíneo Regional/efeitos dos fármacos
17.
Acta Neurol Scand Suppl ; 154: 15-8, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-7941961

RESUMO

INTRODUCTION: The relationship between plasma levels of S-adenosylmethionine (SAMe), an endogenous methyl donor, and clinical response were studied in patients with a DSM-III-R diagnosis of major depression. MATERIAL AND METHODS: A double-blind randomized protocol comparing oral SAMe with oral desipramine, involving a total of 26 patients, was employed. RESULTS: At the end of the 4-week trial, 62% of the patients treated with SAMe and 50% of the patients treated with desipramine had significantly improved. Regardless of the type of treatment, patients with a 50% decrease in their Hamilton Depression Scale (HAM-D) score showed a significant increase in plasma SAMe concentration. CONCLUSION: The significant correlation between plasma SAMe levels and the degree of clinical improvement in depressed patients regardless of the type of treatment suggests that SAMe may play an important role in regulating mood.


Assuntos
Transtorno Depressivo/sangue , Transtorno Depressivo/tratamento farmacológico , S-Adenosilmetionina/sangue , S-Adenosilmetionina/uso terapêutico , Adulto , Transtorno Depressivo/diagnóstico , Desipramina/sangue , Desipramina/farmacologia , Desipramina/uso terapêutico , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Humanos , Masculino , Metionina Adenosiltransferase/metabolismo , Pessoa de Meia-Idade , Escalas de Graduação Psiquiátrica , S-Adenosilmetionina/metabolismo , Resultado do Tratamento
18.
Clin Infect Dis ; 18 Suppl 1: S21-3, 1994 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8148447

RESUMO

Chronic fatigue syndrome (CFS) and primary juvenile fibromyalgia syndrome (PJFS) are illnesses with a similar pattern of symptoms of unknown etiology. Twenty-seven children for whom CFS was diagnosed were evaluated for fibromyalgia by the presence of widespread pain and multiple tender points. Eight children (29.6%) fulfilled criteria for fibromyalgia. Those children who met fibromyalgia criteria had a statistically greater degree of subjective muscle pain, sleep disturbance, and neurological symptoms than did those who did not meet the fibromyalgia criteria. There was no statistical difference between groups in degree of fatigue, headache, sore throat, abdominal pain, depression, lymph node pain, concentration difficulty, eye pain, and joint pain. CFS in children and PJFS appear to be overlapping clinical entities and may be indistinguishable by current diagnostic criteria.


Assuntos
Síndrome de Fadiga Crônica/diagnóstico , Fibromialgia/diagnóstico , Adolescente , Criança , Diagnóstico Diferencial , Síndrome de Fadiga Crônica/fisiopatologia , Feminino , Fibromialgia/fisiopatologia , Humanos , Articulações/fisiopatologia , Masculino , Músculos/fisiopatologia , Sistema Nervoso/fisiopatologia , Dor/fisiopatologia , Transtornos do Sono-Vigília/fisiopatologia
19.
J Bone Joint Surg Br ; 74(4): 558-62, 1992 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-1624516

RESUMO

We report the results of locked Seidel nailing for 30 fractures of the humerus. There were frequent technical difficulties at operation especially with the locking mechanisms. Protrusion of the nail above the greater tuberosity occurred in 12 cases, usually due to inadequate locking, and resulted in shoulder pain and poor function. Poor shoulder function was also seen in five patients with no nail protrusion, presumably because of local rotator cuff damage during insertion. Our results suggest that considerable modifications are required to the nail, and possibly to its site of insertion, before its use can be advocated.


Assuntos
Pinos Ortopédicos , Fraturas do Úmero/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Fraturas do Úmero/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/etiologia , Desenho de Prótese , Radiografia , Amplitude de Movimento Articular , Articulação do Ombro/fisiologia
20.
J Bone Joint Surg Br ; 74(3): 400-2, 1992 May.
Artigo em Inglês | MEDLINE | ID: mdl-1587887

RESUMO

We discuss the role of primary knee arthroplasty in supracondylar and intercondylar fractures of the femur in elderly patients with reference to 13 cases. This method of treatment is shown to be effective and to have good results. It is recommended for all type C and some type A supracondylar fractures in old people.


Assuntos
Fraturas do Fêmur/cirurgia , Prótese do Joelho , Idoso , Idoso de 80 Anos ou mais , Deambulação Precoce , Feminino , Fraturas do Fêmur/diagnóstico por imagem , Humanos , Articulação do Joelho/diagnóstico por imagem , Tempo de Internação , Radiografia
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