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1.
BMC Musculoskelet Disord ; 23(1): 366, 2022 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-35436907

RESUMEN

BACKGROUND: Musculoskeletal disorders are a leading cause of morbidity and the most prevalent source of disability among soldiers. Their high prevalence in armed forces and limited ressources have led to problems related to access to physical rehabilitation care. To increase access, supervised group-based exercise programs for the most prevalent musculoskeletal disorders (low back pain, patellofemoral pain, rotator cuff-related shoulder pain or lateral ankle sprain) have been developed at a Canadian Armed forces (CAF) base, but their effectiveness has not been evaluated. The primary objective of this randomized controlled trial is to evaluate the mid- and long-term effects of these group-based training programs on pain severity and functional limitations, in comparison with usual individual physiotherapy care. Secondary objectives include comparing both interventions in terms of health-related quality of life, pain-related fear, and patients' satisfaction. METHODS: One hundred and twenty soldiers with a new medical referral for physiotherapy services for one of the four targeted musculoskeletal disorders will be consecutively recruited. They will be randomly assigned to either group-based training program or usual individual physiotherapy care, and will take part in the assigned 12-week intervention. There will be four evaluation sessions over 26 weeks (baseline, week 6, 12 and 26). At each follow-up, functional limitations, pain severity, health-related quality of life and pain-related fears will be assessed. Patients satisfaction with treatment will also be evaluated at the end of the intervention period. Either two-way repeated measures ANOVA will be used to analyse and compare the effects of the interventions. DISCUSSION: This RCT will determine the effectiveness of group-based training programs compared to usual individual physiotherapy care. This new intervention model could represent an efficient, and more pro-active approach to manage a higher number of soldiers with musculoskeletal disorders. It could improve access to physical rehabilitation care and improve the health of soldiers. TRIAL REGISTRATION: ClinicalTrials.gov ( NCT05235152 ), February 11th 2022.


Asunto(s)
Personal Militar , Canadá , Terapia por Ejercicio/efectos adversos , Humanos , Modalidades de Fisioterapia , Calidad de Vida , Ensayos Clínicos Controlados Aleatorios como Asunto , Dolor de Hombro/terapia , Resultado del Tratamiento
3.
Diagn Interv Imaging ; 96(1): 73-8, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25466398

RESUMEN

BACKGROUNDS AND AIMS: Hepar lobatum carcinomatosum (HLC) is an exceptional acquired hepatic distortion which consists in irregularly lobulated hepatic contours seen in patients with known liver metastases, usually from breast carcinoma. We aimed to describe and analyze five similar cases of HLC resulting from metastatic mammary carcinoma in the liver and associated with rapid hepatic failure. METHODS: Five cases of HLC were investigated. Medical (including blood liver tests), radiological and histological data (2 cases) were collected and retrospectively analyzed. All patients were followed up for metastatic invasive ductal carcinoma of the breast and had a common pattern of treatment with combination of targeted therapies (bevacizumab, AVASTIN) and chemotherapy (paclitaxel, TAXOL). RESULTS: All the patients showed rapid hepatic failure after a mean of 9 courses of bevacizumab/paclitaxel. In all cases, liver imaging revealed liver capsule retraction and an irregular lobular margin. An apparent tumor regression of all liver metastases was showed in two cases. Biopsies were consistent with sinusoidal obstruction syndrome (SOS) and, surprisingly, no tumoral cells were found. CONCLUSION: Although rare, such an unusual pattern of liver metastasis may mimick acute cirrhosis and cause rapid hepatic failure in patients, despite possible apparent tumor regression on imaging. The etiology of this pathology is unclear, and may involve multiple pathogenic factors. Direct or indirect vascular injury plays an important role in the development of HLC.


Asunto(s)
Neoplasias de la Mama/patología , Carcinoma Ductal de Mama/secundario , Neoplasias Hepáticas/patología , Neoplasias Hepáticas/secundario , Anciano , Femenino , Humanos , Persona de Mediana Edad
4.
Mol Plant Microbe Interact ; 27(2): 125-35, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24156770

RESUMEN

Fire blight caused by Erwinia amylovora is the major bacterial disease of tribe Maleae, including apple. Among the proteins secreted by this bacterium, HrpNEa, also called harpin, is known to induce hypersensitive response in nonhost plants and to form amyloid oligomers leading to pore opening in the plasma membrane and alteration of membrane homeostasis. To better understand the physiological effects of HrpNEa in the host plant, we produced transgenic apple plants expressing HrpNEa with or without a secretion signal peptide (SP). HrpNEa expressed with a SP was found to be associated within the membrane fraction, in accordance with amyloidogenic properties and the presence of transmembrane domains revealed by in silico analysis. Expression analysis of 28 apple defense-related genes revealed gene modulations in the transgenic line expressing membrane-targeted HrpNEa. While apple transgenic trees displaying a high constitutive expression level of SP-HrpNEa showed a slight reduction of infection frequency after E. amylovora inoculation, there was no decrease in the disease severity. Thus HrpNEa seems to act as an elicitor of host defenses, when localized in the host membrane.


Asunto(s)
Proteínas de la Membrana Bacteriana Externa/metabolismo , Erwinia amylovora/metabolismo , Regulación de la Expresión Génica de las Plantas , Malus/inmunología , Enfermedades de las Plantas/inmunología , Proteínas de la Membrana Bacteriana Externa/genética , Membrana Celular/metabolismo , Análisis por Conglomerados , Erwinia amylovora/genética , Erwinia amylovora/patogenicidad , Expresión Génica , Malus/genética , Malus/microbiología , Enfermedades de las Plantas/microbiología , Inmunidad de la Planta , Hojas de la Planta/genética , Hojas de la Planta/inmunología , Hojas de la Planta/microbiología , Plantas Modificadas Genéticamente , Señales de Clasificación de Proteína , Estructura Terciaria de Proteína , Transgenes
5.
Ann Pharm Fr ; 71(2): 84-94, 2013 Mar.
Artículo en Francés | MEDLINE | ID: mdl-23537409

RESUMEN

Nitric oxide (NO) is involved in the regulation of several physiological processes such as vascular homeostasis. Exogenous NO supply offers major therapeutic interest, especially in the treatment of coronary artery disease, ischemic syndromes and other cardiovascular pathologies. Nevertheless, the administration of NO itself is limited by its short half-life. NO prodrugs have been marketed for decades, e.g. organic nitrates for angina pectoris. These prodrugs display undeniable advantages such as angina crisis relief and preconditioning effect. Nevertheless, they suffer from several drawbacks: toxicity, tolerance, endothelial dysfunction exacerbation. These negative effects are related to massive production of reactive species derived from oxygen or nitrogen, which trigger oxidative and nitrosative stress. New NO donors are under development to overcome those disadvantages, among which the S-nitrosothiols family seems especially promising.


Asunto(s)
Enfermedades Cardiovasculares/tratamiento farmacológico , Óxido Nítrico/análogos & derivados , Óxido Nítrico/uso terapéutico , Vasodilatadores/uso terapéutico , Humanos , Óxido Nítrico/fisiología , Donantes de Óxido Nítrico/farmacología , Donantes de Óxido Nítrico/uso terapéutico , Profármacos
6.
Seizure ; 21(1): 51-4, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21996459

RESUMEN

We report a case of Takotsubo syndrome after epilepsy, and review the literature. We identified 59 cases of Takotsubo syndrome after focal or generalised epilepsy. As in Takotsubo syndrome in general, the patients were mostly female (84%), with a mean age of 63 years, and the evolution was generally favourable. There was one death and one stroke, and 4 cases were of relapsing Takotsubo after a new seizure. Takotsubo syndrome may induce cardiac arrhythmias. A near-SUDEP (sudden unexplained death in epilepsy) was reported in one patient. Animal models of SUDEP have shown similar cardiac lesions to those seen in Takotsubo syndrome, and strengthen the hypothesis of a link between these conditions. Takotsubo syndrome after epilepsy may be relatively common; we suggest measurement of serum troponin levels in high-risk patients and cardiac follow-up.


Asunto(s)
Muerte Súbita/etiología , Epilepsia/complicaciones , Cardiomiopatía de Takotsubo/etiología , Antagonistas de Receptores Adrenérgicos beta 1/uso terapéutico , Anticonvulsivantes/uso terapéutico , Aspirina/uso terapéutico , Bisoprolol/uso terapéutico , Epilepsia/tratamiento farmacológico , Epilepsia/fisiopatología , Femenino , Fibrinolíticos/uso terapéutico , Humanos , Lamotrigina , Persona de Mediana Edad , Perindopril/uso terapéutico , Cardiomiopatía de Takotsubo/tratamiento farmacológico , Cardiomiopatía de Takotsubo/fisiopatología , Triazinas/uso terapéutico , Ácido Valproico/uso terapéutico
7.
Ann Pharm Fr ; 65(3): 195-202, 2007 May.
Artículo en Francés | MEDLINE | ID: mdl-17489076

RESUMEN

In a rat model of human essential hypertension (SHR), the chronic increase in cerebral arteriolar blood pressure is accompanied by remodelling with wall hypertrophy and a fall in diameter. The latter produces an increase in cerebrovascular resistance which maintains cerebral blood flow autoregulation at high systemic blood pressure levels, but accentuates hypoperfusion at low arterial pressures such as those observed during and following cerebral ischemia. Using ACE inhibitors and AT1 blockers we have shown that the normalisation of wall thickness is pressure-dependent but that the normalisation of arteriolar diameter relates to a pressure-independent mechanism involving aldosterone. This raises the possibility of new drug targets for arteriolar remodelling involving intracellular sodium-dependent modulation of protein metabolism.


Asunto(s)
Circulación Cerebrovascular/efectos de los fármacos , Trastornos Cerebrovasculares/tratamiento farmacológico , Sistema Renina-Angiotensina/efectos de los fármacos , Bloqueadores del Receptor Tipo 1 de Angiotensina II/uso terapéutico , Animales , Antihipertensivos/uso terapéutico , Trastornos Cerebrovasculares/fisiopatología , Trastornos Cerebrovasculares/prevención & control , Humanos , Hipertensión/complicaciones , Hipertensión/fisiopatología , Antagonistas de Receptores de Mineralocorticoides/uso terapéutico
9.
Phytopathology ; 93(12): 1496-504, 2003 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18943613

RESUMEN

ABSTRACT This study reports the combination of a transgene-mediated defense mechanism with a conventionally bred resistance in order to improve apple scab resistance. Two cultivars of apple (Galaxy, scab-susceptible, and Ariane, carrying the Vf resistance gene) were transformed with endochitinase and exochitinase genes derived from the biocontrol fungus Trichoderma atroviride. The obtained transgenic lines were analyzed for the expression of both genes and resistance to two races of the pathogen Venturia inaequalis: the common race 1 and race 6 which overcomes the resistance conferred by the Vf gene. A negative correlation between growth of transgenic lines and endochitinase activity was observed. Reduced growth appeared to be associated with high lignin content and high peroxidase as well as glucanase activity, suggesting that endochitinase activity may disturb the metabolism of the plant. Scab inoculation with races 1 and 6 performed in a growth chamber on 14 lines of normal vigor identified 6 lines with significantly enhanced resistance. Ten lines with reduced vigor were tested in vitro with a bioassay on rooted shoots. All lines expressing high endochitinase activity exhibited a significant reduction of scab symptoms.

10.
Cell Mol Life Sci ; 59(8): 1366-76, 2002 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-12363039

RESUMEN

Animal prion proteins (PrPs) form at the sequence level a very homogenous and 'closed' family. Therefore, few of their structural and functional features can be gleaned from sequence comparison as is now possible on a wide scale for other protein families. To detect putatively related proteins (at the structural and/or functional level), we used a battery of sequence analysis tools. This analysis resulted in (i) the identification of a putative 'prion-like' domain within the envelope of foamy retroviruses, (ii) the detection of putative similarities between prions and an interferon-inducible membrane protein, and (iii) the proposal that of the TATA-box-binding protein is a structural scaffold, which might allow understanding of a key event leading to the structural conversion from PrP(C) (normal cellular prion structure) towards PrP(Sc) (pathogenic structure).


Asunto(s)
Priones/química , Secuencia de Aminoácidos , Animales , Proteínas de Unión al ADN/genética , Proteínas Ligadas a GPI , Humanos , Interferones/metabolismo , Proteínas de la Membrana/genética , Datos de Secuencia Molecular , Priones/genética , Estructura Terciaria de Proteína , Alineación de Secuencia , Análisis de Secuencia de Proteína , Spumavirus/química , Spumavirus/genética , Proteína de Unión a TATA-Box , Factores de Transcripción/genética
11.
Cell Mol Life Sci ; 59(12): 2144-54, 2002 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-12568340

RESUMEN

Prion diseases are neurodegenerative disorders associated with a conformational conversion of the prion PrP protein, in which the beta strand content increases and that of the a helix decreases. However, the structure of the pathogenous form PrP(Sc), occurring after conformational conversion of the normal cellular form PrP(C), is not yet known. From sequence analysis, we have previously proposed that helix H2 of the prion PrP(C) structure might be a key region for this structural conversion. More recently, we identified the TATA box-binding protein fold as a putative scaffold that may locally satisfy the predicted secondary-structure organisation of PrP(Sc). In the present analysis, we detail the schematic construction of PrP(Sc) monomeric and dimeric models, based on this hypothesis. These models are globally compatible with available data and therefore may provide further insights into the structurally and functionally elusive PrP protein. Some comments are also devoted to a comparison of the yeast Ure2p prion and animal prions.


Asunto(s)
Proteínas PrPSc/química , Análisis de Secuencia de Proteína , Secuencia de Aminoácidos , Animales , Dimerización , Glutatión Peroxidasa , Humanos , Ratones , Modelos Moleculares , Datos de Secuencia Molecular , Proteínas PrPSc/metabolismo , Priones/química , Conformación Proteica , Pliegue de Proteína , Estructura Cuaternaria de Proteína , Estructura Secundaria de Proteína , Estructura Terciaria de Proteína , Proteínas de Saccharomyces cerevisiae/química
12.
Am J Physiol Heart Circ Physiol ; 281(4): H1476-80, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11557535

RESUMEN

We examined cerebral arteriolar structure and autoregulation of cerebral blood flow (CBF) in control (n = 8), sham-operated (n = 8), pinealectomized (n = 10), and pinealectomized plus melatonin-treated (0.51 +/- 0.01 mg x kg(-1) x day(-1) in drinking water, n = 9) young Wistar rats. The lower limit of CBF autoregulation (LLCBF) was determined by measurement of CBF (in arbitrary units, laser Doppler) during stepwise hypotensive hemorrhage; the arteriolar internal diameter (ID; in microm, cranial window) was also measured. Measurements of ID were repeated during a second stepwise hypotension after smooth muscle cell deactivation (67 mmol/l EDTA). The cross-sectional area (CSA) was measured by histometry. CSA and EDTA-induced vasodilatation decreased after pinealectomy (517 +/- 21 vs. 819 +/- 40 microm(2) in sham and 829 +/- 55 microm(2) in control, P < 0.05, and 81 +/- 4 vs. 102 +/- 5 microm in sham and 104 +/- 4 microm in control, P < 0.05, respectively) and were restored by melatonin (924 +/- 39 microm(2) and 102 +/- 5 microm, respectively). These results suggest that melatonin deprival makes the arteriolar wall thinner and stiffer. However, these changes had little effect on LLCBF. In conclusion, pinealectomy of young rats induces atrophy and decreases distensibility of the cerebral arteriolar wall; these effects are prevented by melatonin. They do not modify LLCBF.


Asunto(s)
Circulación Cerebrovascular/fisiología , Glándula Pineal/fisiología , Animales , Arteriolas/anatomía & histología , Arteriolas/fisiología , Arteriolas/fisiopatología , Homeostasis/fisiología , Hipotensión/fisiopatología , Masculino , Melatonina/fisiología , Ratas , Ratas Wistar , Valores de Referencia , Vasodilatación
13.
Blood Cells Mol Dis ; 26(5): 427-36, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11112380

RESUMEN

The influence of lipoxygenase metabolites of arachidonic acid on proliferation and differentiation of CD34(+) cells was studied. Their effects on the CFU-GM and BFU-E progenitors were investigated by culture of CD34(+) cells in liquid or semisolid medium. Only 12-HETE (1 microM) stimulated the [(3)H]thymidine as well as BrdU incorporation and increased the number of cell divisions (PKH2 tracking). Addition of 12-HETE and 15-HETE but not of LXA(4), LXB(4), LTB(4), and LTC(4) to liquid cultures of CD34(+) cells for 3 and 8 days reduced in a time-dependent manner the number of CFU-GM and BFU-E. Both HETEs also increased the percentage of glycophorin A(+) cells while they reduced the percentage of CD34(-)/CD33(+) cells after 3 and 5 days of liquid cultures. These results show that HETE treatment stimulates proliferation and accelerates the differentiation of CD34(+) cells, mostly toward the erythroid lineage.


Asunto(s)
Antígenos CD34/análisis , Ácidos Araquidónicos/farmacología , División Celular/efectos de los fármacos , Células Madre Hematopoyéticas/efectos de los fármacos , Lipoxinas , Lipooxigenasa/metabolismo , Ácido 12-Hidroxi-5,8,10,14-Eicosatetraenoico/farmacología , Antígenos de Diferenciación/biosíntesis , Antígenos de Diferenciación/efectos de los fármacos , Ácidos Araquidónicos/metabolismo , Recuento de Células , Ensayo de Unidades Formadoras de Colonias , Medios de Cultivo/farmacología , Relación Dosis-Respuesta a Droga , Células Precursoras Eritroides/citología , Células Precursoras Eritroides/efectos de los fármacos , Eritropoyetina/farmacología , Células Madre Hematopoyéticas/química , Células Madre Hematopoyéticas/citología , Humanos , Ácidos Hidroxieicosatetraenoicos/farmacología , Leucotrieno B4/farmacología , Metilcelulosa , Soluciones , Timidina/metabolismo , Factores de Tiempo
14.
Ann Dermatol Venereol ; 127(1): 29-32, 2000 Jan.
Artículo en Francés | MEDLINE | ID: mdl-10717559

RESUMEN

OBJECTIVE: Meningeal involvement is frequent in metastatic melanoma, approximately 30% in autopsy series. Functional signs may be misleading and the neurological examination may be normal. Certain diagnosis requires identification of tumor cells in the cerebrospinal fluid. CSF cytology is however sometimes negative and magnetic resonance imaging (MRI) with gadolinium injection may provide the diagnosis. The aim of this retrospective study was to assess the role of imaging in the diagnosis of leptomeningeal carcinomatosis. PATIENTS AND METHODS: The diagnosis of leptomeningeal carcinomatosis was made in 8 patients between 1992 and 1998. All had signs of neurological function impairment, but the neurology examination was abnormal in only 2. RESULTS: Cytology examination of the cerebrospinal fluid provided the diagnosis of leptomeningeal carcinomatosis in 5 patients. One out of 5 brain CT scans were positive, showing meningeal enhancement confirmed by brain MRI. The spinal tap was not contributive in 2 cases and was not done in 1. In these three cases, the brain CT did not provide any diagnostic element while the brain MRI with gadolinium injection confirmed the diagnosis of leptomeningeal carcinomatosis. DISCUSSION: Forty-one percent of patients with autopsy proven leptomeningeal carcinomatosis have a normal ante mortem spinal tap. Brain MRI with gadolinium injection has better sensitivity than brain CT scan. All patients with nonspecific neurological signs and a normal spinal tap should be explored with a brain MRI.


Asunto(s)
Encéfalo/patología , Imagen por Resonancia Magnética , Melanoma/secundario , Neoplasias Meníngeas/secundario , Meningitis/diagnóstico , Adolescente , Adulto , Anciano , Encéfalo/diagnóstico por imagen , Neoplasias Encefálicas/líquido cefalorraquídeo , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/patología , Neoplasias Encefálicas/secundario , Femenino , Estudios de Seguimiento , Humanos , Neoplasias Pulmonares/secundario , Masculino , Melanoma/líquido cefalorraquídeo , Melanoma/diagnóstico , Melanoma/patología , Neoplasias Meníngeas/líquido cefalorraquídeo , Neoplasias Meníngeas/diagnóstico , Neoplasias Meníngeas/patología , Meningitis/líquido cefalorraquídeo , Persona de Mediana Edad , Tabique Nasal , Neoplasias Nasales/patología , Estudios Retrospectivos , Sensibilidad y Especificidad , Neoplasias Cutáneas/patología , Factores de Tiempo , Tomografía Computarizada por Rayos X
15.
Neuroreport ; 11(18): 4087-92, 2000 Dec 18.
Artículo en Inglés | MEDLINE | ID: mdl-11192633

RESUMEN

We have used event-related potentials (ERP) to assess cerebral activity following mild traumatic brain injuries in 20 college athletes practising contact sports. Concussion victims showed a striking decrease in P300 amplitude, an effect presumed to reflect alterations in attentional-cognitive processes. Moreover, the degree of impairment was strongly related to the severity of post-concussion symptoms. Our data suggest that concussions cause objectively measurable changes in the electrophysiological markers of brain activity and hence in the functions of the structures from which they originate. ERPs may thus constitute a reliable method to accurately monitor the clinical course and recovery of head injuries in athletes.


Asunto(s)
Traumatismos en Atletas/fisiopatología , Conmoción Encefálica/fisiopatología , Encéfalo/fisiopatología , Potenciales Relacionados con Evento P300/fisiología , Adulto , Traumatismos en Atletas/complicaciones , Encéfalo/patología , Conmoción Encefálica/complicaciones , Electroencefalografía , Humanos , Masculino
17.
Mediators Inflamm ; 7(1): 31-3, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-9839696

RESUMEN

The effects of various lipoxygenase metabolites of arachidonic acid (AA) were investigated on the growth of freshly isolated human bone marrow mononuclear cells and marrow stromal cell cultures. LTB4, LXA4, LXB4, 12-HETE and 15-HETE (1 microM) decreased [3H]-thymidine incorporation on marrow stromal cell cultures without affecting cell number. Only 12-HETE showed a dose-response effect on [3H]-thymidine incorporation. While LTB4 (1 microM) decreased thymidine incorporation on marrow mononuclear cells, LTC4, LXA4, LXB4, 12-HETE and 15-HETE had no effect. The lipoxygenase inhibitor NDGA had no effect on both cell types suggesting no role of endogenous lipoxygenase metabolites on cell growth. These results suggest no important role of lipoxygenase metabolites of AA on the proliferation of human marrow mononuclear cells and marrow stromal cell cultures.


Asunto(s)
Ácido Araquidónico/metabolismo , Células de la Médula Ósea/citología , Lipooxigenasa/metabolismo , Células de la Médula Ósea/metabolismo , División Celular , Células Cultivadas , Humanos , Leucocitos Mononucleares/citología , Células del Estroma/citología
18.
Mediators Inflamm ; 7(2): 99-103, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-9836496

RESUMEN

We have assessed the effect of platelet-activating factor (PAF), a biologically active phospholipid present in the human marrow, on the growth of human marrow and blood CD34+ progenitors. While the metabolization rate of PAF by CD34+ cells is low (weak acetylhydrolase and acylation processes) it is readily catabolized by the acetylhydrolase activity present in the growth medium (10% fetal calf serum + 10% 5637-conditioned medium). Treatment of marrow CD34+ cells with the non-metabolizable PAF agonist C-PAF (1 nM to 100 nM) immediately before semi-solid culture significantly (P < 0.01) decreased the number of BFU-E but not of CFU-GM colonies. Treatment of marrow or blood CD34+ cells with C-PAF (10-100 nM) for 3 days in liquid medium before semi-solid culture significantly (P < 0.01) decreased the number of BFU-E and CFU-GM colonies. Treatment of blood CD34+ cells with the two PAF receptor antagonists CV 3988 and BN 52021 (1 microM) had no significant effect on the number of BFU-E and CFU-GM colonies suggesting no role of endogenous PAF in these processes. These results show that exogenous PAF downregulates human erythropoiesis and myelopoiesis, a result that might be of importance during inflammatory states.


Asunto(s)
Antígenos CD34 , Células Precursoras Eritroides/efectos de los fármacos , Factor de Activación Plaquetaria/farmacología , División Celular/efectos de los fármacos , Células Cultivadas , Humanos
19.
Eur J Clin Invest ; 28(10): 856-63, 1998 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-9793000

RESUMEN

BACKGROUND: The tetrapeptide acetyl-Ser-Asp-Lys-Pro (AcSDKP), a physiological inhibitor of the proliferation of haematopoietic stem cells, is degraded by the angiotensin-I-converting enzyme (ACE). Whereas synthetic AcSDKP (Goralatide) protects normal mice from the haematological toxicity of chemotherapy, it has a lower beneficial effect in humans. This discrepancy could be dependent on Goralatide administration schedules, as well as on the endogenous concentrations of AcSDKP and ACE, which vary during chemotherapy. METHODS: We investigated the effect of one myelotoxic dose of 5-fluorouracil (5-FU, 200 mg kg-1) administered without or with Goralatide on blood, bone marrow (BM) and spleen AcSDKP concentrations, ACE activity, nucleated cell counts and survival of the primitive haematopoietic progenitors high proliferative potential colony-forming cells (HPP-CFCs). RESULTS: The 5-FU treatment dramatically decreased the BM concentrations of AcSDKP by 73% and increased the ACE activity in plasma by 50% during the period of active BM regeneration. Repeated injections of Goralatide from 24 h before to 36 h after the i.p. injection of 5-FU spared BM HPP-CFCs. As an injection of 10 mg of Goralatide induced a short peak of plasma AcSDKP without modifying its BM concentrations, we suggest that its protective effect on HPP-CFCs could be mediated by its interference with other plasma molecules targeting to the BM. CONCLUSION: By improving our knowledge of the biology of AcSDKP in vivo during chemotherapy, our results could help to better define the therapeutic use of Goralatide.


Asunto(s)
Antimetabolitos Antineoplásicos/toxicidad , Fluorouracilo/toxicidad , Hematopoyesis/efectos de los fármacos , Oligopéptidos/metabolismo , Oligopéptidos/farmacología , Animales , Médula Ósea/efectos de los fármacos , Recuento de Células , Femenino , Células Madre Hematopoyéticas/efectos de los fármacos , Ratones , Peptidil-Dipeptidasa A/metabolismo , Bazo/efectos de los fármacos
20.
J Lipid Mediat Cell Signal ; 16(3): 117-25, 1997 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-9246601

RESUMEN

Freshly isolated human marrow mononuclear cells produce lipidic compounds such as PAF and leukotrienes. These lipidic molecules act on human marrow myelopoiesis and erythropoiesis by modulating the growth of committed progenitors (CFU-GM and BFU-E) in vitro. Nanomolar concentrations of leukotriene B4 and C4 stimulate the growth of human marrow CFU-GM. In contrast, micromolar concentrations of lipoxygenase inhibitors (NDGA and BW755C) decrease their growth suggesting a role for endogenous lipoxygenase metabolites in this process. Micromolar concentrations of prostaglandin E2 up-regulate and down-regulate the growth of marrow BFU-E and CFU-GM, respectively. In contrast, the other cyclooxygenase metabolites have no effect. Recent studies indicate that nanomolar concentrations of PAF decrease the growth of CFU-GM and BFU-E from purified marrow CD34+ cells. Together these results indicate that lipidic mediators act on human myelopoiesis and erythropoiesis. However at this time the mechanisms and molecular signals mediating the effects of lipidic molecules on human marrow cells are unexplored.


Asunto(s)
Células de la Médula Ósea , Eicosanoides/farmacología , Células Precursoras Eritroides/efectos de los fármacos , Hematopoyesis/efectos de los fármacos , Células Madre Hematopoyéticas/efectos de los fármacos , Lípidos/farmacología , Factor de Activación Plaquetaria/farmacología , Médula Ósea/efectos de los fármacos , Médula Ósea/metabolismo , División Celular/efectos de los fármacos , Células Precursoras Eritroides/citología , Granulocitos/citología , Granulocitos/efectos de los fármacos , Granulocitos/metabolismo , Células Madre Hematopoyéticas/citología , Humanos , Lipooxigenasa/metabolismo , Factor de Activación Plaquetaria/metabolismo , Prostaglandina-Endoperóxido Sintasas/metabolismo
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