Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
1.
Acta Chir Belg ; : 1-6, 2024 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-38954403

RESUMEN

BACKGROUND: Pericardial cysts are infrequent lesions. Most of these are asymptomatic and incidental findings during investigations for unrelated conditions. When they are symptomatic, they demonstrate most of the time a benign clinical course. Yet, treatment is sometimes necessary. Besides a (temporary) treatment as percutaneous aspiration, there is surgery as a definite treatment. The aim of the paper is to motivate the safety and efficacy of uniportal video assisted thoracoscopy (UVATS) for the excision of (giant) pericardial cysts and describe their (peri-)operative technique. METHODS: In this retrospective, single center-based case series, we report all cases with a pericardial cyst who underwent a surgical excision by uniportal VATS (UVATS) between March 2022 and April 2023. Detailed patient characteristics, operation details, hospital length of stay and follow-up data were collected. RESULTS: A total of 4 patients underwent excision of a pericardial cyst by UVATS. The follow-up ranged from 10 to 20 months. The mean diameter of the pericardial cyst was 124 mm. Median procedure time was 94 min. No per- and postoperative complications occurred. The median length of postoperative hospital stay was 2 days. All patients showed a clinically relevant improvement of the pre-operative symptoms. CONCLUSIONS: Uniportal VATS excision for pericardial cysts is a safe and effective surgical procedure with good outcomes on symptom relief. Though, future comparative studies are urged to elucidate its value among other treatment options.

2.
Acta Chir Belg ; 123(4): 430-435, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35037823

RESUMEN

BACKGROUND: Mycotic aortic aneurysms (MAA) arise due to infection of a pre-existent aneurysm or aneurysmal degeneration of an infected vascular wall. MAA of the thoracic aorta are relatively rare. Treatment is mainly guided by clinical experience as there are no large randomized trials available. CASE PRESENTATION: A 79-year-old patient was hospitalized with staphylococcus aureus sepsis and MAA originating from the ostium of the left common carotid artery (CCA). Initial treatment consisted of high-dose antibiotics and blood pressure control. After 48 hours, a CT-angiography revealed rapid growth of the MAA with imminent rupture. Various treatment options were considered: a covered stent in the left CCA, a carotid-subclavian bypass with ligation of the left CCA ostium or arch replacement, or an extra-anatomical transposition of the supra-aortic vessels combined with a thoracic endoprosthesis. The last option was selected and, combined with six weeks of antibiotics, proved successful in controlling the impending rupture and treating the MAA. CONCLUSIONS: Endovascular techniques are used if open surgery is refused, when surgical risks are prohibitively high (as definitive or palliative treatment), or as an emergency temporary treatment until definitive surgical treatment is feasible. Our high-risk patient underwent endovascular treatment for MAA as a definitive treatment. Endovascular treatment is increasingly becoming the treatment of choice due to the high morbidity and mortality of open surgical repair. Although the main concern using endovascular treatment is absence of debridement, recent studies show that combining endovascular treatment and long-term antibiotic therapy represents a potentially durable treatment and viable alternative to open surgical repair.


Asunto(s)
Aneurisma Infectado , Hemoptisis , Sepsis , Infecciones Estafilocócicas , Staphylococcus aureus , Infecciones Estafilocócicas/diagnóstico , Infecciones Estafilocócicas/tratamiento farmacológico , Sepsis/diagnóstico , Humanos , Masculino , Anciano , Aneurisma Infectado/diagnóstico , Antibacterianos , Procedimientos Endovasculares
3.
Acta Chir Belg ; 123(1): 81-84, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33820491

RESUMEN

Since December 2019, the outbreak of the novel coronavirus disease (COVID-19) in China has rapidly spread throughout the world. During the course of the COVID-19 pandemic, thrombotic complications have emerged as an important issue. We present two cases of symptomatic arterial thrombosis in patients with confirmed COVID-19. The first patient presented with digital ischemia due to distal embolization from a floating thrombus in the proximal left subclavian artery, and the second one with bilateral acute limb ischemia due to thrombosis of the right popliteal artery and left tibioperoneal trunk. This case report illustrates that arterial thrombosis associated with COVID-19 can occur even in the absence of severe respiratory disease and clinically relevant peripheral arterial disease.


Asunto(s)
COVID-19 , Trombosis , Humanos , COVID-19/complicaciones , Pandemias , Trombosis/etiología , Pierna/irrigación sanguínea , Isquemia
4.
Mediators Inflamm ; 2016: 6467375, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27051078

RESUMEN

Atherosclerosis remains the leading cause of death and disability in our Western society. To investigate whether the dynamics of leukocyte (sub)populations could be predictive for plaque inflammation during atherosclerosis, we analyzed innate and adaptive immune cell distributions in blood, plaques, and lymphoid tissue reservoirs in apolipoprotein E-deficient (ApoE(-/-)) mice and in blood and plaques from patients undergoing endarterectomy. Firstly, there was predominance of the CD11b(+) conventional dendritic cell (cDC) subset in the plaque. Secondly, a strong inverse correlation was observed between CD11b(+) cDC or natural killer T (NKT) cells in blood and markers of inflammation in the plaque (including CD3, T-bet, CCR5, and CCR7). This indicates that circulating CD11b(+) cDC and NKT cells show great potential to reflect the inflammatory status in the atherosclerotic plaque. Our results suggest that distinct changes in inflammatory cell dynamics may carry biomarker potential reflecting atherosclerotic lesion progression. This not only is crucial for a better understanding of the immunopathogenesis but also bares therapeutic potential, since immune cell-based therapies are emerging as a promising novel strategy in the battle against atherosclerosis and its associated comorbidities. The cDC-NKT cell interaction in atherosclerosis serves as a good candidate for future investigations.


Asunto(s)
Aterosclerosis/inmunología , Aterosclerosis/metabolismo , Antígeno CD11b/metabolismo , Células Dendríticas/metabolismo , Inflamación/metabolismo , Células T Asesinas Naturales/metabolismo , Anciano , Animales , Apolipoproteínas E/deficiencia , Apolipoproteínas E/metabolismo , Células Cultivadas , Progresión de la Enfermedad , Femenino , Humanos , Tejido Linfoide/citología , Masculino , Ratones , Ratones Noqueados , Placa Aterosclerótica
5.
J Endovasc Ther ; 18(4): 497-500, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21861736

RESUMEN

PURPOSE: To present a case of penetrating aortic ulcer with extraordinary etiology. CASE REPORT: A 57-year-old man was admitted with acute retrosternal and interscapular pain. He was a demolition worker and often used a pneumatic drill to which he pressed his chest as he drilled. Clinical examination showed previously undiagnosed hypertension. Computed tomographic angiography disclosed a penetrating aortic ulcer in the descending thoracic aorta without any sign of atherosclerosis. Initial treatment consisted of blood pressure control. However, due to progression of the lesion, endovascular treatment was performed to implant a covered endoprosthesis. CONCLUSION: We hypothesize that the etiology of the ulcer was the shear forces developed by incorrect, repetitive use of the pneumatic hammer in combination with the untreated hypertension. This is analogous to the hypothenar hammer syndrome, and we propose naming this the "aortic hammer syndrome."


Asunto(s)
Enfermedades de la Aorta/etiología , Industria de la Construcción , Hipertensión/complicaciones , Enfermedades Profesionales/etiología , Úlcera/etiología , Antihipertensivos/uso terapéutico , Enfermedades de la Aorta/diagnóstico por imagen , Enfermedades de la Aorta/cirugía , Aortografía/métodos , Implantación de Prótesis Vascular , Dolor en el Pecho/etiología , Procedimientos Endovasculares , Hematoma/etiología , Humanos , Hipertensión/diagnóstico , Hipertensión/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Enfermedades Profesionales/diagnóstico por imagen , Enfermedades Profesionales/cirugía , Estrés Mecánico , Síndrome , Tomografía Computarizada por Rayos X , Resultado del Tratamiento , Úlcera/diagnóstico por imagen , Úlcera/cirugía
6.
NanoImpact ; 23: 100337, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-35559838

RESUMEN

The coming years are expected to bring rapid changes in the nanotechnology regulatory landscape, with the establishment of a new framework for nano-risk governance, in silico approaches for characterisation and risk assessment of nanomaterials, and novel procedures for the early identification and management of nanomaterial risks. In this context, Safe(r)-by-Design (SbD) emerges as a powerful preventive approach to support the development of safe and sustainable (SSbD) nanotechnology-based products and processes throughout the life cycle. This paper summarises the work undertaken to develop a blueprint for the deployment and operation of a permanent European Centre of collaborating laboratories and research organisations supporting safe innovation in nanotechnologies. The proposed entity, referred to as "the Centre", will establish a 'one-stop shop' for nanosafety-related services and a central contact point for addressing stakeholder questions about nanosafety. Its operation will rely on significant business, legal and market knowledge, as well as other tools developed and acquired through the EU-funded EC4SafeNano project and subsequent ongoing activities. The proposed blueprint adopts a demand-driven service update scheme to allow the necessary vigilance and flexibility to identify opportunities and adjust its activities and services in the rapidly evolving regulatory and nano risk governance landscape. The proposed Centre will play a major role as a conduit to transfer scientific knowledge between the research and commercial laboratories or consultants able to provide high quality nanosafety services, and the end-users of such services (e.g., industry, SMEs, consultancy firms, and regulatory authorities). The Centre will harmonise service provision, and bring novel risk assessment and management approaches, e.g. in silico methodologies, closer to practice, notably through SbD/SSbD, and decisively support safe and sustainable innovation of industrial production in the nanotechnology industry according to the European Chemicals Strategy for Sustainability.


Asunto(s)
Nanoestructuras , Nanotecnología , Industrias , Medición de Riesgo
7.
J Immunol Methods ; 417: 76-85, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25527343

RESUMEN

Different immune cell types are present within atherosclerotic plaques. Dendritic cells (DC) are of special interest, since they are considered as the 'center of the immuniverse'. Identifying inflammatory DC subtypes within plaques is important for a better understanding of the lesion pathogenesis and pinpoints their contribution to the atherosclerotic process. We have developed a flow cytometry-based method to characterize and isolate different DC subsets (i.e. CD11b(+), Clec9A(+) and CD16(+) conventional (c)DC and CD123(+) plasmacytoid (p)DC) in human atherosclerotic plaques. We revealed a predominance of pro-inflammatory CD11b(+) DC in advanced human lesions, whereas atheroprotective Clec9A(+) DC were almost absent. CD123(+) pDC and CD16(+) DC were also detectable in plaques. Remarkably, plaques from distinct anatomical locations exhibited different cellular compositions: femoral plaques contained less CD11b(+) and Clec9A(+) DC than carotid plaques. Twice as many monocytes/macrophages were observed compared to DC. Moreover, relative amounts of T cells/B cells/NK cells were 6 times as high as DC numbers. For the first time, fluorescent activated cell sorting analysis of DC subsets in human plaques indicated a predominance of CD11b(+) cDC, in comparison with other DC subsets. Isolation of the different subsets will facilitate detailed functional analysis and may have significant implications for tailoring appropriate therapy.


Asunto(s)
Aterosclerosis/inmunología , Separación Celular/métodos , Células Dendríticas/inmunología , Citometría de Flujo/métodos , Placa Aterosclerótica/inmunología , Anciano , Anciano de 80 o más Años , Linfocitos B/citología , Antígeno CD11b/metabolismo , Femenino , Proteínas Ligadas a GPI/metabolismo , Humanos , Inflamación/inmunología , Subunidad alfa del Receptor de Interleucina-3/metabolismo , Células Asesinas Naturales/citología , Lectinas Tipo C/metabolismo , Macrófagos/citología , Masculino , Persona de Mediana Edad , Monocitos/citología , Receptores de IgG/metabolismo , Receptores Mitogénicos/metabolismo , Linfocitos T/citología
8.
Kidney Int ; 63(5): 1697-707, 2003 May.
Artículo en Inglés | MEDLINE | ID: mdl-12675845

RESUMEN

BACKGROUND: After ischemia/reperfusion (I/R), as well as after toxic insults, there is significant infiltration of leukocytes in the kidney. It is well known that antibodies against adhesion molecules [e.g., intercellular adhesion molecule-1 (ICAM-1)] protect the kidney against acute ischemic injury. In contrast, same antibody treatment did not protect the rat kidney against toxic acute renal failure (ARF) induced by HgCl2. Protection obtained by anti-adhesion treatment in I/R injury is an early phenomenon, since delaying the administration of anti-ICAM-1 for 8 hours did not protect the kidney anymore. The aim of this study was to compare the early ICAM-1 expression and leukocyte accumulation in different zones of ischemic and toxic injury. METHODS: Male Lewis rats were injected with HgCl2 (2 mg/kg, subcutaneously) or uninephrectomized Lewis rats were submitted to 30 degrees C warm ischemia (I/R injury). Rats were sacrificed at 2, 6, 12 and 24 hours. ICAM-1 (1A29) expression in kidney was evaluated morphometrically. Different subsets of leukocytes were stained by immunohistochemistry and counted in cortex, the outer stripe of the outer medulla (OSOM) and the level of the inner stripe of the outer medulla (ISOM). RESULTS: Although the functional and morphologic damage was comparable between the I/R and toxic ARF group, different ICAM-1 expression could be observed early after injury. ICAM-1 expression in the ISOM started already 2 hours after the onset of I/R injury, and was increased after 12 hours in the cortex and after 24 hours in the OSOM. In contrast, during the first 24 hours after injury, ICAM-1 expression in HgCl2-injured kidneys was not different from noninjured kidneys in the ISOM and the cortex, whereas in the OSOM, ICAM-1 expression increased. The number of polymononuclear cells (PMNs) was low in noninjured kidneys and did not increase in time after both I/R injury and after HgCl2-induced ARF. In the ISOM, significant monocyte and T-cell accumulation was observed early after I/R but not after HgCl2. There was no significant T-cell accumulation in the cortex or in the OSOM. CONCLUSION: After HgCl2, almost no leukocyte accumulation and up-regulation of ICAM-1 was observed the first 12 hours after injury. In contrast, very early after I/R injury, increased expression of ICAM-1 goes along with monocyte and T-cell accumulation in the ISOM, endorsing this particular zone as critical in renal I/R injury. These observations contribute to the understanding why anti-ICAM-1 treatment in acute I/R injury is successful, but fails in acute toxic injury induced by HgCl2.


Asunto(s)
Lesión Renal Aguda/metabolismo , Molécula 1 de Adhesión Intercelular/metabolismo , Isquemia/metabolismo , Leucocitos/citología , Lesión Renal Aguda/inducido químicamente , Lesión Renal Aguda/patología , Animales , Adhesión Celular , Isquemia/patología , Corteza Renal/metabolismo , Corteza Renal/patología , Médula Renal/metabolismo , Médula Renal/patología , Macrófagos/citología , Masculino , Cloruro de Mercurio , Monocitos/citología , Neutrófilos/citología , Ratas , Ratas Endogámicas Lew , Linfocitos T/citología , Regulación hacia Arriba
9.
Am J Transplant ; 3(5): 570-80, 2003 May.
Artículo en Inglés | MEDLINE | ID: mdl-12752313

RESUMEN

The influence of chronic renal failure on renal susceptibility to an acute ischemic insult was evaluated. Recipient Lewis rats were randomly assigned to undergo 5/6 nephrectomy (chronic renal failure, CRF) or sham operation (normal renal function, NRF). After 11 weeks, normal kidneys of Lewis donor rats were transplanted in the recipients. The outcome of the isografts was assessed. Filtration capacity of the isografts in the CRF rats was preserved to approximately one-quarter of its normal capacity on the 1st day post-transplantation, whereas it fell to 0 in the NRF rats. This was reflected by a significantly higher increase in serum creatinine in the latter group. The isografts in the CRF rats had a significantly lower degree of acute tubular necrosis and no increase in the number of macrophages and T lymphocytes in the first 24 h in contrast to the NRF rats. Epithelial regeneration and repair started earlier in the CRF group. In conclusion, the present study indicated that CRF blunted ischemia/reperfusion injury of a transplanted kidney, and that its regeneration capacity was certainly not hampered by the presence of chronic uremia. These results will be the basis for studies on modulation of early leukocyte-endothelial interactions resulting from immunological disturbances inherent to the uremic environment.


Asunto(s)
Fallo Renal Crónico/terapia , Trasplante de Riñón/efectos adversos , Daño por Reperfusión/prevención & control , Trasplante Isogénico/métodos , Animales , Peso Corporal , Supervivencia de Injerto , Inmunohistoquímica , Isquemia , Riñón/metabolismo , Riñón/fisiología , Leucocitos/metabolismo , Macrófagos/metabolismo , Neutrófilos/metabolismo , Ratas , Ratas Endogámicas Lew , Circulación Renal , Linfocitos T/metabolismo , Factores de Tiempo
10.
J Am Soc Nephrol ; 15(8): 2219-28, 2004 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-15284308

RESUMEN

Adequate control of phosphate levels remains an important issue in patients with chronic renal failure (CRF). Lanthanum carbonate has been proposed as a new phosphate binder. Previous studies have shown a high phosphate binding capacity (>97%) and low gastrointestinal absorption of lanthanum, without serious toxic side effects in the presence of a normal renal function (NRF). Because of lanthanum's physicochemical resemblance to calcium, the possible effects of it on bone have to be considered. The aim of this study was to investigate the effects of lanthanum carbonate on bone histology in NRF and CRF rats after oral administration of the compound with doses of 100, 500, or 1000 mg/kg per d for 12 wk. Bone histomorphometry showed that CRF animals that received vehicle developed secondary hyperparathyroidism. Urinalysis of lanthanum-loaded CRF animals showed a dose-dependent decrease in urinary phosphorus excretion, which was clearly more pronounced in the CRF groups compared with NRF animals. Phosphatemia, however, remained normal. Lanthanum carbonate administration induced a dose-dependent decrease in bone formation rate and increase in osteoid area in CRF animals. Three of seven animals in the CRF-1000 group and one of eight animals in the NRF-100 group were classified as having a mineralization defect. The number of cuboidal osteoblasts, however, was not affected, indicating that bone changes were not due to a toxic effect of lanthanum on the osteoblast. Furthermore, lanthanum concentrations in the femur remained low and did not correlate with histomorphometric parameters. These findings suggest that the administration of high doses of phosphate binder (1000 mg/kg per d lanthanum carbonate), in combination with decreased 25-(OH) vitamin D(3) in the uremic state, resulted in phosphate depletion and followed by an increased mobilization of phosphorus out of bone and/or reduced incorporation into bone. There was no evidence that lanthanum had a direct toxic effect on osteoblasts.


Asunto(s)
Enfermedades Óseas/tratamiento farmacológico , Remodelación Ósea/efectos de los fármacos , Fallo Renal Crónico/complicaciones , Lantano/farmacocinética , Fosfatos/metabolismo , Fosfatasa Alcalina/sangre , Animales , Enfermedades Óseas/sangre , Enfermedades Óseas/patología , Huesos/efectos de los fármacos , Huesos/metabolismo , Huesos/patología , Calcio/sangre , Creatinina/sangre , Ingestión de Alimentos , Lantano/sangre , Masculino , Osteoblastos/efectos de los fármacos , Osteocalcina/sangre , Hormona Paratiroidea/sangre , Fósforo/sangre , Ratas , Ratas Wistar , Vitamina D/sangre
11.
Kidney Int ; 66(2): 491-6, 2004 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-15253695

RESUMEN

Inflammation has been established to contribute substantially to the pathogenesis of ischemia/reperfusion (I/R) with a central role for particular cells, adhesion molecules, and cytokines. Until recently, most of the research trying to unravel the pathogenesis of I/R injury has been focused on the role of neutrophils. However, recent studies have brought evidence that T cells and macrophages are also important leukocyte mediators of renal and extrarenal (liver) I/R injury. In vivo depletion of CD4+ cells but not CD8+ cells in wild-type mice was protective in I/R of the kidney. A marked preservation of liver function was also found after I/R in T-cell deficient athymic mice. Blocking the b130/CD28 costimulatory pathway by CTLA-4 Ig (recombinant fusion protein) ameliorated renal dysfunction and decreased mononuclear cell infiltration in I/R of the kidney. b130-1 expression was found limited to the membrane of the endothelial cells of the ascending vasa recta, resulting in trapping of CD28-expressing CD4 T cells. This trapping of leukocytes results in the upstream congestion in the ascending arterial vasa recta, generating the since more than 150 years described medullary vascular congestion of the kidney soon after ischemic injury. It seems worthwhile to study a combination therapy using anti-inflammatory/anti-adhesion molecules in the early phase of I/R.


Asunto(s)
Lesión Renal Aguda/inmunología , Daño por Reperfusión/inmunología , Linfocitos T/inmunología , Lesión Renal Aguda/patología , Lesión Renal Aguda/fisiopatología , Animales , Humanos , Daño por Reperfusión/patología , Daño por Reperfusión/fisiopatología
12.
Kidney Int ; 64(3): 864-73, 2003 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-12911536

RESUMEN

BACKGROUND: Post-ischemia/reperfusion (I/R) damage, accompanied by leukocyte infiltration, is unavoidable in renal transplantation, as is the need for immunosuppressive treatment. Influence of immunosuppressive treatment on post-I/R renal damage, nonalloimmune cellular infiltration, and regeneration is not well studied. METHODS: Uninephrectomized inbred LEW rats were submitted to warm renal ischemia of 45 minutes/60 minutes, and received different immunosuppressive regimens: cyclosporine (CsA) 10 mg/kg/day subcutaneously in the neck daily, or mycophenolate mofetil (MMF) 20 mg/kg/day by daily oral gavage. Control animals underwent sham operation (unilateral nephrectomy) with immunosuppressive treatment or ischemia with vehicle administration. In addition the effect of MMF/mycophenolic acid (MPA) on renal tubule cell proliferation in culture was studied with bromodeoxyuridine incorporation. RESULTS: The post-I/R interstitial cellular infiltration/proliferation consisted mainly of mononuclear leukocytes [first monocytes/macrophages (Mo/MPhi) followed by CD4+ cells]. This mononuclear cell infiltration became apparent 24 hours after injury at the time of acute tubular necrosis, and was most prominent during the phase of regeneration. Severe I/R combined with CsA aggravated morphologic damage and dysfunction, without effect on tubular cell proliferation and tubular regeneration. Early leukocyte infiltration was qualitatively and quantitatively comparable to control animals, yet decreased moderately later in time. In contrast, MMF in combination with severe I/R did not influence initial morphologic damage and dysfunction. Although the initial leukocyte infiltration was comparable to control animals, the subsequent mononuclear cell accumulation, especially CD4 T cells decreased dramatically during MMF treatment. This was concomitant with a decrease of tubular cell proliferation and hence tubular regeneration. Increasing MPA concentrations in renal tubular cell culture caused a significant decrease in total cell number, and an almost arrest of bromodeoxyuridine incorporation, as measurement of cell proliferation. CONCLUSION: Immunosuppressive treatment with CsA or MMF affected significantly and in a different manner post-I/R renal morphologic damage, interstitial leukocyte, accumulation and regeneration.


Asunto(s)
Terapia de Inmunosupresión , Leucocitos/patología , Ácido Micofenólico/análogos & derivados , Regeneración , Circulación Renal , Daño por Reperfusión/patología , Daño por Reperfusión/fisiopatología , Animales , División Celular , Ciclosporina/farmacología , Inmunosupresores/farmacología , Riñón/efectos de los fármacos , Riñón/patología , Riñón/fisiopatología , Necrosis Tubular Aguda/etiología , Necrosis Tubular Aguda/patología , Necrosis Tubular Aguda/fisiopatología , Masculino , Ácido Micofenólico/farmacología , Ratas , Ratas Endogámicas Lew , Daño por Reperfusión/complicaciones , Índice de Severidad de la Enfermedad
13.
Kidney Int ; 63(3): 927-35, 2003 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-12631073

RESUMEN

BACKGROUND: We previously reported on increased bone strontium (Sr) levels in dialysis patients with osteomalacia versus those presenting other types of renal osteodystrophy. A causal role of strontium in the development of osteomalacia was established in a chronic renal failure (CRF) rat model. METHODS: In the present study we investigated whether the effect of Sr on bone was related to dosage. Four groups of CRF rats were studied: a control group (control-CFR; N=6) not receiving strontium and three groups of animals loaded orally with Sr during 18 weeks by adding the element as the SrCl2. H20 compound to the drinking water at concentrations of 0.03 g/100mL (Sr-30; N=6), 0.075 g/100mL (Sr-75; N=6), or 0.15 g/100mL (Sr-150; N=6) respectively. A fifth group consisting of seven animals with intact renal function (control-NRF), not receiving Sr served as controls for the effect of CRF on bone histology. RESULTS: As compared to the control-NRF and control-CRF groups, Sr administration resulted in a dose-dependent increase in bone and serum Sr levels. No difference in body weight and biochemical serum and urinary parameters [i.e., calcium (Ca), phosphorus (P), and creatinine] was noted between the various CRF groups. At sacrifice, intact parathyroid hormone (iPTH) levels of CRF groups were significantly (P < 0.05) higher than the values measured in the control-NRF group indicating the development of hyperparathyroidism secondary to the installation of the CRF. This is further supported by the differences in bone histomorphometry between the control-CRF and control-NRF animals, which, respectively, showed an increased amount of osteoid (mean +/- SEM 3.4 +/- 1.2% vs. 0.37 +/- 0.14%, P < 0.05) in combination with a distinct osteoblastic activity (35 +/- 11% vs. <2%, P < 0.05) and an increased bone formation rate [(BFR), 677 +/- 177 microm 2/mm2/day vs. 130 +/- 50 microm 2/mm2/day, P < 0.05]. Bone surface area and erodic perimeter did not differ between the various study groups. In the Sr-30 group, Sr loading went along with a dramatic reduction of the BFR as indicated by the total absence of double tetracyclin labels and osteoblastic activity, which in the presence of a low to normal amount of osteoid (2.7 +/- 1.9%) points to the development of the adynamic type of renal osteodystrophy. Interestingly, compared to the control-CRF group, histodynamic and histologic parameters of the Sr-75 group did not differ significantly and a substantial osteoblastic activity (7.6 +/- 4.0%) was seen also. In the Sr-150 group, the various osteoid parameters were significantly (P < 0.05) increased vs. all other groups and were accompanied by a reduced BFR and mineral apposition rate (MAR) and an increased mineralization lag time (MLT), indicating a mineralization defect and the development of osteomalacia. CONCLUSIONS: Our findings indicate that the role of Sr in the development of bone lesions in renal failure is complex and that, depending on the dose, the element may act via multiple pathways.


Asunto(s)
Fallo Renal Crónico/complicaciones , Osteomalacia/tratamiento farmacológico , Osteomalacia/etiología , Estroncio/farmacología , Animales , Calcificación Fisiológica/efectos de los fármacos , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Masculino , Nefrectomía , Osteoblastos/fisiología , Ratas , Ratas Wistar
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA