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1.
Curr Hypertens Rep ; 17(6): 551, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25893475

RESUMEN

By eliminating glucose in the urine, the sodium-glucose-linked cotransporter-2 (SGLT2) inhibitors act as osmotic diuretics to lower blood pressure in addition to reducing plasma glucose and assisting with weight loss. While not approved as antihypertensive agents, the ability of this new class of antihyperglycemic agents to lower blood pressure is not insubstantial, and while not used primarily for this indication, they may assist diabetic individuals in attaining currently recommended blood pressure targets. In addition to lowering systemic pressure, preclinical and exploratory human studies suggest that SGLT2 inhibitors may also lower intraglomerular pressure, potentially reducing the rate of GFR decline in patients with diabetic nephropathy. However, given the lack of clinically meaningful endpoint data, the use of SGLT2 inhibitors, primarily, as either antihypertensive or renoprotective agents would, at present, be premature. Fortunately, further insight will be garnered from large, randomized controlled trials that will assess the effects of various SGLT2 inhibitors on cardiovascular and renal outcomes.


Asunto(s)
Antihipertensivos/farmacología , Citoprotección , Riñón/efectos de los fármacos , Inhibidores del Cotransportador de Sodio-Glucosa 2 , Antihipertensivos/uso terapéutico , Complicaciones de la Diabetes/metabolismo , Humanos , Hipertensión/tratamiento farmacológico , Transportador 2 de Sodio-Glucosa/metabolismo
2.
Am J Physiol Renal Physiol ; 297(3): F822-34, 2009 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-19605547

RESUMEN

Glomerular matrix accumulation is a hallmark of diabetic nephropathy. We have recently shown that epidermal growth factor receptor (EGFR) transactivation mediates high glucose (HG)-induced collagen I upregulation through PI3K-PKCbeta1-Akt signaling in mesangial cells (MC). Phospholipase Cgamma1 (PLCgamma1) interacts with activated growth factor receptors and activates classic PKC isoforms. We thus studied its role in HG-induced collagen I upregulation in MC. Primary rat MC were treated with HG (30 mM) or mannitol as osmotic control. Protein kinase activation was assessed by Western blotting and collagen I upregulation by Northern blotting. Diabetes was induced in rats by streptozotocin. HG treatment for 1 h led to PLCgamma1 membrane translocation and Y783 phosphorylation, both indicative of its activation. Mannitol was without effect. PLCgamma1 Y783 phosphorylation was also seen in cortex and glomeruli of diabetic rats. HG induced a physical association between EGFR and PLCgamma1 as identified by coimmunoprecipitation. PLCgamma1 activation required EGFR kinase activity since it was prevented by the EGFR inhibitor AG1478 or overexpression of kinase-inactive EGFR (K721A). Phosphoinositide-3-OH kinase inhibition also prevented PLCgamma1 activation. HG-induced Akt S473 phosphorylation, effected by PKCbeta1, was inhibited by the PLCgamma inhibitor U73122. PLCgamma1 inhibition or downregulation by small interference RNA also prevented HG-induced collagen I upregulation. Our results indicate that EGFR-PLCgamma1 signaling mediates HG-induced PKCbeta1-Akt activation and subsequent collagen I upregulation in MC. Inhibition of EGFR or PLCgamma1 may provide attractive therapeutic targets for the treatment of diabetic nephropathy.


Asunto(s)
Glucemia/metabolismo , Colágeno Tipo I/metabolismo , Diabetes Mellitus Experimental/complicaciones , Nefropatías Diabéticas/enzimología , Receptores ErbB/metabolismo , Células Mesangiales/enzimología , Fosfolipasa C gamma/metabolismo , Proteína Quinasa C/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Animales , Células Cultivadas , Diabetes Mellitus Experimental/enzimología , Nefropatías Diabéticas/etiología , Nefropatías Diabéticas/prevención & control , Activación Enzimática , Inhibidores Enzimáticos/farmacología , Receptores ErbB/antagonistas & inhibidores , Estrenos/farmacología , Femenino , Masculino , Fosfatidilinositol 3-Quinasas/metabolismo , Inhibidores de las Quinasa Fosfoinosítidos-3 , Fosfolipasa C gamma/antagonistas & inhibidores , Fosfolipasa C gamma/genética , Fosforilación , Proteína Quinasa C beta , Pirrolidinonas/farmacología , Quinazolinas , Interferencia de ARN , Ratas , Ratas Sprague-Dawley , Tirfostinos/farmacología , Regulación hacia Arriba
3.
Mem Inst Oswaldo Cruz ; 104(2): 312-5, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19430659

RESUMEN

The current treatment of ocular toxoplasmosis is controversial. The mainstay of treatment has been pyrimethamine and sulphonamides with or without systemic corticosteroids, but the actual evidence that antibiotics have a beneficial effect in recurrent toxoplasmic retinochoroiditis is unsupported by randomised placebo controlled trials. Thus far there have only been three studies looking at the efficacy of antibiotic treatment, all of which were methodologically weak and two of which were perfomed more than 30 years ago. All studies reported adverse effects from treatment. There is an urgent need for further randomised, double blind, placebo controlled studies for lesions in all parts of the retina and to test the efficacy of adjunctive corticosteroid treatment.


Asunto(s)
Corticoesteroides/uso terapéutico , Antiprotozoarios/uso terapéutico , Medicina Basada en la Evidencia , Toxoplasmosis Ocular/tratamiento farmacológico , Coriorretinitis/prevención & control , Ensayos Clínicos como Asunto , Humanos
4.
J Public Health (Oxf) ; 30(4): 479-86, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18765405

RESUMEN

BACKGROUND: Since 1997, UK guidance has advocated limiting antibiotic prescribing for otitis media. It is not known whether this has influenced general practitioner prescribing practice. Aims and objectives To investigate the trends in diagnoses and antibiotic prescribing for otitis media in children in relation to guidance. METHODS: We used the General Practice Research Database to conduct time-trend analyses of diagnoses and antibiotic prescribing for otitis media in 3 months to 15 years old, between 1990 and 2006. RESULTS: A total of 1 210 237 otitis media episodes were identified in 464 845 children; two-thirds (68%; 818 006) received antibiotics. Twenty-two percent (267 335) were classified as acute, 85% (227 335) of which received antibiotics. Overall, antibiotic prescribing for otitis media declined by 51% between 1995 and 2000. Much of this reduction predated guidance. During this period, prescribing for otitis media coded as acute increased by 22%. Children diagnosed with acute otitis media were more likely to receive antibiotics than otitis media not coded as acute (P < 0.05). From 2000 prescribing plateaued, despite publication of further guidance. Otitis media diagnoses consistently paralleled prescribing. CONCLUSIONS: The reduction in antibiotic prescribing for otitis media predated guidance. The simultaneous decrease in prescribing for non-acute otitis media and increase for acute otitis media suggest diagnostic transfer, possibly to justify the decision to treat.


Asunto(s)
Antibacterianos/uso terapéutico , Medicina Familiar y Comunitaria/estadística & datos numéricos , Adhesión a Directriz/estadística & datos numéricos , Otitis Media/tratamiento farmacológico , Guías de Práctica Clínica como Asunto , Pautas de la Práctica en Medicina/estadística & datos numéricos , Adolescente , Amoxicilina/economía , Amoxicilina/uso terapéutico , Antibacterianos/economía , Niño , Preescolar , Intervalos de Confianza , Bases de Datos como Asunto , Eritromicina/economía , Eritromicina/uso terapéutico , Femenino , Humanos , Lactante , Masculino , Otitis Media/economía , Otitis Media/epidemiología , Reino Unido/epidemiología
5.
Cardiovasc Res ; 76(2): 280-91, 2007 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-17716638

RESUMEN

OBJECTIVE: Diabetic cardiomyopathy is an increasingly recognized cause of cardiac failure despite preserved left ventricular systolic function. Given the over-expression of angiotensin II in human diabetic cardiomyopathy, we hypothesized that combining hyperglycaemia with an enhanced tissue renin-angiotensin system would lead to the development of diastolic dysfunction with adverse remodeling in a rodent model. METHODS: Homozygous (mRen-2)27 rats and non-transgenic Sprague Dawley (SD) rats were randomized to receive streptozotocin (diabetic) or vehicle (non-diabetic) and followed for 6 weeks. Prior to tissue collection, animals underwent pressure-volume loop acquisition. RESULTS: Diabetic Ren-2 rats developed impairment of both active and passive phases of diastole, accompanied by reductions in SERCA-2a ATPase and phospholamban along with activation of the fetal gene program. Structural features of diabetic cardiomyopathy in the Ren-2 rat included interstitial fibrosis, cardiac myocyte hypertrophy and apoptosis in conjunction with increased activity of transforming growth factor-beta (p<0.01 compared with non-diabetic Ren-2 rats for all parameters). No significant functional or structural derangements were observed in non-transgenic, SD diabetic rats. CONCLUSION: These findings indicate that the combination of enhanced tissue renin-angiotensin system and hyperglycaemia lead to the development of diabetic cardiomyopathy. Fibrosis, and myocyte hypertrophy, a prominent feature of this model, may be a consequence of activation of the pro-sclerotic cytokine, transforming growth factor-beta, by the diabetic state.


Asunto(s)
Diabetes Mellitus Experimental/complicaciones , Diástole , Insuficiencia Cardíaca/fisiopatología , Miocardio/patología , Renina/genética , Animales , Animales Modificados Genéticamente , Apoptosis , Modelos Animales de Enfermedad , Insuficiencia Cardíaca/genética , Insuficiencia Cardíaca/patología , Masculino , Ratas , Ratas Sprague-Dawley , ATPasas Transportadoras de Calcio del Retículo Sarcoplásmico/análisis , Estreptozocina , Factor de Crecimiento Transformador beta/análisis
6.
J Clin Invest ; 99(5): 1016-27, 1997 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-9062360

RESUMEN

The accelerated formation of advanced glycation end products (AGEs) and the overexpression of transforming growth factor beta (TGF-beta) have both been implicated in the pathogenesis of diabetic microvascular and macrovascular complications. Previous studies in our laboratory have demonstrated that the vascular changes in diabetes include hypertrophy of the mesenteric vasculature. To examine the role of AGEs in this process, streptozotocin-induced diabetic rats and control animals were randomized to receive aminoguanidine, an inhibitor of AGE formation, or no treatment. Animals were studied at 7 d, 3 wk, and 8 mo after induction of diabetes. When compared with control animals, diabetes was associated with an increase in mesenteric vascular weight and an increase in media wall/lumen area. By Northern analysis, TGF-beta1 gene expression was increased 100-150% (P < 0.01) and alpha1 (IV) collagen gene expression was similarly elevated to 30-110% compared to controls (P < 0.05). AGEs and extracellular matrix were present in abundance in diabetic but not in control vessels. Treatment of diabetic rats with aminoguanidine resulted in significant amelioration of the described pathological changes including overexpression of TGF-beta1 and alpha1 (IV) collagen. These data implicate the formation of AGEs in TGF-beta overexpression and tissue changes which accompany the diabetic state.


Asunto(s)
Diabetes Mellitus Experimental/complicaciones , Diabetes Mellitus Experimental/genética , Regulación de la Expresión Génica , Productos Finales de Glicación Avanzada/genética , Productos Finales de Glicación Avanzada/metabolismo , Arterias Mesentéricas/metabolismo , Arterias Mesentéricas/patología , Factor de Crecimiento Transformador beta/genética , Factor de Crecimiento Transformador beta/metabolismo , Animales , Northern Blotting , Peso Corporal , Colágeno/genética , Colágeno/inmunología , Colágeno/metabolismo , Sondas de ADN/genética , Diabetes Mellitus Experimental/metabolismo , Matriz Extracelular/metabolismo , Glucosa/análisis , Productos Finales de Glicación Avanzada/inmunología , Guanidinas/farmacología , Hipertrofia/genética , Inmunohistoquímica , Hibridación in Situ , Masculino , ARN Mensajero/genética , ARN Mensajero/metabolismo , Radioinmunoensayo , Ratas , Ratas Sprague-Dawley
7.
Circ Res ; 87(12): 1133-40, 2000 Dec 08.
Artículo en Inglés | MEDLINE | ID: mdl-11110770

RESUMEN

Vascular disease often involves vessel hypertrophy with underlying cellular hypertrophy or hyperplasia. Experimental diabetes stimulates hypertrophy of the rat mesenteric vasculature, and we investigated the hypothesis that this hypertrophy is associated with activation of Na(+)-H(+) exchange (NHE) activity. We measured the NHE activity in isolated, intact blood vessels from control and streptozotocin-induced diabetic adult rats using concurrent myography and fluorescence spectroscopy. The role of inhibiting NHE activity in preventing the development of the mesenteric hypertrophy in streptozotocin-diabetic rats was investigated by administration of cariporide (100 mg/kg body weight per day in 3 doses by gavage) after induction of diabetes and subsequently determining vessel weight and structure. The weight of the mesenteric vasculature was not increased 1 week after streptozotocin treatment but was significantly increased by an average of 56% at 3 weeks. NHE activity in mesenteric arteries showed an enhanced maximal velocity (V:(max)) in diabetic vessels at 1 and 3 weeks (0.246+/-0.006 and 0. 238+/-0.007 versus 0.198+/-0.007 pH U/min) with no change in the apparent K:(m). Moreover, NHE-1 mRNA in mesenteric arterioles at 3 weeks after streptozotocin treatment was increased by >60% (55.8+/-6. 4 versus 91.3+/-12.3 fg). Administration of cariporide significantly reduced mesenteric vascular weight, the wall/lumen ratio, and mesenteric extracellular matrix accumulation in the diabetic animals. Our study shows that diabetes in vivo correlates with elevated NHE activity and mRNA in the mesenteric vasculature and furthermore that inhibition of this system prevents the hypertrophic response. These data suggest that NHE may be a target for therapeutic modulation of vascular changes in diabetes.


Asunto(s)
Diabetes Mellitus Experimental/complicaciones , Hipertrofia/etiología , Intercambiadores de Sodio-Hidrógeno/metabolismo , Animales , Antiarrítmicos/farmacología , Vasos Sanguíneos , Diabetes Mellitus Experimental/inducido químicamente , Diabetes Mellitus Experimental/metabolismo , Modelos Animales de Enfermedad , Guanidinas/farmacología , Concentración de Iones de Hidrógeno , Hipertrofia/metabolismo , Masculino , Arterias Mesentéricas/efectos de los fármacos , Arterias Mesentéricas/metabolismo , Músculo Liso Vascular/metabolismo , Ratas , Ratas Sprague-Dawley , Estreptozocina , Sulfonas/farmacología
8.
Circ Res ; 86(2): 158-65, 2000 Feb 04.
Artículo en Inglés | MEDLINE | ID: mdl-10666411

RESUMEN

Vascular hypertrophy, a feature of experimental and human diabetes, has been implicated in the pathogenesis of the microvascular and macrovascular complications of the disease. In the present study, we sought to examine the role of endogenous endothelin and its relation to vascular growth factors in the mediation of vascular hypertrophy in experimental diabetes and to examine the contribution of mast cells to this process. Vessel morphology, endothelin, growth factor gene expression, and matrix deposition were studied in the mesenteric arteries of control and streptozotocin-induced diabetic Sprague-Dawley rats treated with or without the dual endothelin(A/B) receptor antagonist bosentan (100 mg x kg(-1) x d(-1)) during a 3-week period. Compared with control animals, diabetic animals had significant increases in vessel weight, wall-to-lumen ratio, mast cell infiltration, extracellular matrix deposition, and gene expression of epidermal growth factor (EGF) and transforming growth factor-beta(1). In diabetic, but not control, vessels, not only were EGF mRNA and endothelin present in endothelial cells, but also their expression was observed in adventitial mast cells. Immunoreactive endothelin was present in the media of mesenteric vessels of diabetic, but not control, animals. Bosentan treatment significantly reduced mesenteric weight, wall-to-lumen ratio, mast cell infiltration, matrix deposition, and EGF mRNA but did not prevent the overexpression of transforming growth factor-beta(1) mRNA in diabetic rats. These findings suggest that endogenous endothelin and EGF may play a role in diabetes-induced vascular hypertrophy and that mast cells may be pathogenetically involved in this process.


Asunto(s)
Diabetes Mellitus Experimental/patología , Antagonistas de los Receptores de Endotelina , Endotelio Vascular/patología , Factor de Crecimiento Epidérmico/genética , Mastocitos/inmunología , Animales , Antihipertensivos/farmacología , Northern Blotting , Bosentán , Diabetes Mellitus Experimental/tratamiento farmacológico , Angiopatías Diabéticas/tratamiento farmacológico , Angiopatías Diabéticas/patología , Endotelio Vascular/inmunología , Matriz Extracelular/patología , Expresión Génica/fisiología , Hipertrofia , Hibridación in Situ , Masculino , Arterias Mesentéricas/patología , ARN Mensajero/análisis , Ratas , Ratas Sprague-Dawley , Sulfonamidas/farmacología
9.
Br J Ophthalmol ; 90(12): 1464-7, 2006 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-16899532

RESUMEN

AIM: To compare the clinical findings in children with symptomatic toxoplasmic ocular lesions attributable to infection acquired before or after birth. METHODS: Cases were prospectively ascertained for 24 months through national surveillance units and reference laboratories in the British Isles. Age and presenting symptoms, site of lesion and visual impairment in children who were classified as acquiring infection either before or after birth on the basis of clinical and serological findings were compared. RESULTS: 31 children had toxoplasmic retinochoroiditis, 15 had congenital infection and all but three of these presented before the age of 4 years. The remaining 16 children acquired toxoplasmosis postnatally, and 14 of 16 presented after the age of 10 years. A further four children had retinochoroiditis due to other causes. The presence of bilateral, multiple or posterior pole lesions did not distinguish between the two groups, but most children (16/19; 84%) presenting with acute ocular symptoms had postnatally acquired infection. Unilateral visual impairment (Snellen < or =6/18) was equally prevalent in the two groups (4/9 before birth v 7/16 after birth; p>0.5). Only two children had bilateral visual impairment, both of whom had congenital infection. No child was blind. CONCLUSIONS: About 50% of children with ocular lesions due to toxoplasmosis had postnatal infection. Retinochoroidal lesions due to infection before and after birth were indistinguishable. The prognosis for bilateral visual function was good, regardless of when infection was acquired.


Asunto(s)
Coriorretinitis/parasitología , Complicaciones Parasitarias del Embarazo , Toxoplasmosis Ocular/transmisión , Trastornos de la Visión/parasitología , Adolescente , Edad de Inicio , Niño , Preescolar , Coriorretinitis/patología , Femenino , Humanos , Lactante , Recién Nacido , Transmisión Vertical de Enfermedad Infecciosa , Embarazo , Pronóstico , Estudios Prospectivos , Toxoplasmosis Ocular/complicaciones , Toxoplasmosis Ocular/congénito , Toxoplasmosis Ocular/patología
10.
Diabetes ; 43(5): 649-55, 1994 May.
Artículo en Inglés | MEDLINE | ID: mdl-8168641

RESUMEN

This study describes patterns of progression of albuminuria and renal function in a subgroup of 40 patients from a total cohort of 211 diabetic patients (118 type I, 93 type II) followed over a period of 8-14 years. Forty patients (18 with type I diabetes, 22 with type II diabetes) showed progressive increases in albumin excretion rate (AER) and/or decreases in creatinine clearance (CC) during the study period. Of these, AER alone increased in 15 patients, AER increased and CC decreased in 13 patients, and CC alone decreased in 12 patients, with a similar distribution of type I and type II diabetic patients in each group. Of the 28 patients who showed an increase in albuminuria, AER increased at an annual rate of 30-40%, resulting in a 4- to 8-fold increase in AER to > 20 micrograms/min during the study. Of the 25 patients who showed a decrease in renal function, CC decreased at an annual rate of 4-5 ml/min, resulting in an approximate halving of CC to < 90 ml/min during the study. The rate of fall in CC was not related to the presence or absence of concomitant increases in albuminuria. However, a significant preponderance of women in the group showed a decline in CC alone. The decline in CC was associated with an increase in plasma creatinine as well as a progressive decrease in urinary creatinine excretion, but the underlying mechanisms remain unexplained. These data support the concept that a subgroup of diabetic patients may show a decline in renal function in the absence of significant increases in AER.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Albuminuria , Diabetes Mellitus Tipo 1/fisiopatología , Diabetes Mellitus Tipo 2/fisiopatología , Nefropatías Diabéticas/fisiopatología , Riñón/fisiopatología , Adulto , Presión Sanguínea , Peso Corporal , Creatinina/metabolismo , Diabetes Mellitus Tipo 1/sangre , Diabetes Mellitus Tipo 1/orina , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/orina , Nefropatías Diabéticas/sangre , Nefropatías Diabéticas/orina , Femenino , Estudios de Seguimiento , Tasa de Filtración Glomerular , Humanos , Hipertensión/fisiopatología , Masculino , Persona de Mediana Edad , Factores Sexuales , Factores de Tiempo
11.
Diabetes ; 47(3): 414-22, 1998 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-9519748

RESUMEN

Transforming growth factor-beta (TGF-beta) and the renin-angiotensin system (RAS) have both been implicated in the pathogenesis of glomerulosclerosis in diabetic kidney disease. However, tubulointerstitial pathology may also be an important determinant of progressive renal dysfunction in diabetic nephropathy. In the present study, we investigated tubulointerstitial injury, TGF-beta1 expression, and the effect of blocking the RAS by inhibition of ACE. We randomized 36 male SD rats to control and diabetic groups. Diabetes was induced in 24 rats by administration of streptozotocin; 12 diabetic rats were further randomized to receive the ACE inhibitor ramipril (3 mg/l drinking water). At 6 months, experimental diabetes was associated with tubulointerstitial damage, a 70% increase in expression of TGF-beta1 (P < 0.05 vs. control), and a 120% increase in alpha1 (IV) collagen gene expression (P < 0.01 vs. control). In situ hybridization demonstrated a diffuse increase in both TGF-beta1 and alpha1 (IV) collagen mRNA in renal tubules. In addition, intense expression of both transcripts was noted in regions of focal tubular dilatation. Administration of the ACE inhibitor ramipril prevented tubulointerstitial injury and the overexpression of TGF-beta1 and alpha1 (IV) collagen mRNA. Changes in gene expression were accompanied by parallel changes in immunostaining for TGF-beta1 and type IV collagen. The observed beneficial effects of ramipril on the tubulointerstitium in experimental diabetes suggest that this mechanism may contribute to the therapeutic effect of ACE inhibitors in diabetic nephropathy.


Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Colágeno/genética , Diabetes Mellitus Experimental/complicaciones , Nefropatías Diabéticas/patología , Túbulos Renales/química , Ramipril/farmacología , Factor de Crecimiento Transformador beta/genética , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Animales , Estudios de Cohortes , Colágeno/biosíntesis , Colágeno/clasificación , Nefropatías Diabéticas/tratamiento farmacológico , Regulación del Desarrollo de la Expresión Génica/genética , Inmunohistoquímica , Hibridación in Situ , Túbulos Renales/efectos de los fármacos , Túbulos Renales/patología , Masculino , ARN Mensajero/análisis , ARN Mensajero/genética , Ramipril/uso terapéutico , Distribución Aleatoria , Ratas , Ratas Sprague-Dawley , Sistema Renina-Angiotensina/efectos de los fármacos , Factor de Crecimiento Transformador beta/biosíntesis
12.
Diabetes ; 48(11): 2229-39, 1999 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-10535459

RESUMEN

It has been suggested that the cytokine vascular endothelial growth factor (VEGF) has an important role in the pathogenesis of diabetic retinopathy, but its role in nephropathy has not been clearly demonstrated. Assessment of VEGF, 125I-VEGF binding, and vascular endothelial growth factor receptor-2 (VEGFR-2) in the kidney was performed after 3 and 32 weeks of streptozotocin-induced diabetes. Gene expression of both VEGF and VEGFR-2 was assessed by Northern blot analysis and the localization of the ligand and receptor was examined by in situ hybridization. VEGF and VEGFR-2 protein were also evaluated by immunohistochemistry. Binding of the radioligand 125I-VEGF was evaluated by in vitro and in vivo autoradiography. Diabetes was associated with increased renal VEGF gene expression. VEGF mRNA and protein were localized to the visceral epithelial cells of the glomerulus and to distal tubules and collecting ducts in both diabetic and nondiabetic rats. Renal VEGFR-2 mRNA was increased after 3 weeks of diabetes but not in long-term diabetes. In situ hybridization and immunohistochemical studies revealed that glomerular endothelial cells were the major site of VEGFR-2 expression. In addition, VEGFR-2 gene expression was detected in cortical and renomedullary interstitial cells and on endothelial cells of peritubular capillaries. There was an increase in 125I-VEGF binding sites after 3 but not 32 weeks of diabetes. The major VEGF binding sites were in the glomeruli. 125I-VEGF binding was also observed in medullary rays and in the renal papillae. These studies indicate an early and persistent increase in renal VEGF gene expression in association with experimental diabetes. In addition, an early and transient increase in renal VEGF receptors was also observed in diabetic rats. These findings are consistent with a role for VEGF in mediating some of the changes observed in the diabetic kidney.


Asunto(s)
Diabetes Mellitus Experimental/metabolismo , Factores de Crecimiento Endotelial/genética , Regulación de la Expresión Génica , Riñón/metabolismo , Linfocinas/genética , Proteínas Tirosina Quinasas Receptoras/genética , Receptores de Factores de Crecimiento/genética , Animales , Glucemia/metabolismo , Presión Sanguínea , Northern Blotting , Peso Corporal , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/fisiopatología , Factores de Crecimiento Endotelial/metabolismo , Inmunohistoquímica , Hibridación in Situ , Linfocinas/metabolismo , ARN Mensajero/genética , Ratas , Ratas Sprague-Dawley , Proteínas Tirosina Quinasas Receptoras/metabolismo , Receptores de Factores de Crecimiento/metabolismo , Receptores de Factores de Crecimiento Endotelial Vascular , Transcripción Genética , Factor A de Crecimiento Endotelial Vascular , Factores de Crecimiento Endotelial Vascular
13.
Curr Opin Pharmacol ; 1(2): 183-9, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11714094

RESUMEN

Diabetes and hypertension are major contributors to the increasing incidence of progressive renal disease. In addition to more potent antihypertensive agents that block the renin-angiotensin system, drugs that modulate other pathogenetic pathways are also in development. Recent preclinical studies indicate that compounds that interfere with the formation and action of advanced glycation end products may have a role in the treatment and prevention of diabetic nephropathy, as may agents targeting the activity of protein kinase C.


Asunto(s)
Enfermedades Renales/tratamiento farmacológico , Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Animales , Ensayos Clínicos como Asunto , Nefropatías Diabéticas/complicaciones , Nefropatías Diabéticas/tratamiento farmacológico , Nefropatías Diabéticas/prevención & control , Productos Finales de Glicación Avanzada/antagonistas & inhibidores , Productos Finales de Glicación Avanzada/metabolismo , Humanos , Hipertensión/complicaciones , Hipertensión/tratamiento farmacológico , Hipertensión/prevención & control , Enfermedades Renales/etiología , Enfermedades Renales/prevención & control , Fallo Renal Crónico/tratamiento farmacológico , Fallo Renal Crónico/epidemiología , Fallo Renal Crónico/etiología , Neprilisina/antagonistas & inhibidores , Proteína Quinasa C/antagonistas & inhibidores , Receptor para Productos Finales de Glicación Avanzada , Receptores Inmunológicos/antagonistas & inhibidores , Sistema Renina-Angiotensina/efectos de los fármacos , Transducción de Señal
14.
BMC Pediatr ; 5: 21, 2005 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-15998464

RESUMEN

BACKGROUND: We aimed to determine how response to a parent-completed postal questionnaire measuring development, behaviour, impairment, and parental concerns and anxiety, varies in different European centres. METHODS: Prospective cohort study of 3 year old children, with and without congenital toxoplasmosis, who were identified by prenatal or neonatal screening for toxoplasmosis in 11 centres in 7 countries. Parents were mailed a questionnaire that comprised all or part of existing validated tools. We determined the effect of characteristics of the centre and child on response, age at questionnaire completion, and response to child drawing tasks. RESULTS: The questionnaire took 21 minutes to complete on average. 67% (714/1058) of parents responded. Few parents (60/1058) refused to participate. The strongest determinants of response were the score for organisational attributes of the study centre (such as direct involvement in follow up and access to an address register), and infection with congenital toxoplasmosis. Age at completion was associated with study centre, presence of neurological abnormalities in early infancy, and duration of prenatal treatment. Completion rates for individual questions exceeded 92% except for child completed drawings of a man (70%), which were completed more by girls, older children, and in certain centres. CONCLUSION: Differences in response across European centres were predominantly related to the organisation of follow up and access to correct addresses. The questionnaire was acceptable in all six countries and offers a low cost tool for assessing development, behaviour, and parental concerns and anxiety, in multinational studies.


Asunto(s)
Conducta Infantil , Desarrollo Infantil , Discapacidades del Desarrollo/diagnóstico , Padres , Encuestas y Cuestionarios , Toxoplasmosis Congénita/complicaciones , Preescolar , Discapacidades del Desarrollo/etiología , Europa (Continente) , Femenino , Humanos , Análisis Multivariante , Pruebas Neuropsicológicas , Embarazo , Complicaciones Parasitarias del Embarazo , Estudios Prospectivos
15.
Diabetes Care ; 19(7): 730-4, 1996 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-8799628

RESUMEN

OBJECTIVE: To determine the extent of interlaboratory variation and accuracy in the measurement of glycated hemoglobin (GHb). RESEARCH DESIGN AND METHODS: All laboratories that measure glycated hemoglobin in the State of Victoria, Australia, were invited to participate, and positive responses were received from 27 to 30 laboratories. An aliquot of blood drawn from three patients with diabetes and varied glycemia and from one nondiabetic subject was sent to each participating laboratory. Distribution of results was analyzed according to the reported results and their variance from an assigned reference value and were expressed as differing from this latter value as percentage bias and in absolute terms. A bias > or = 10% or an absolute difference of > or = 1% HbA1c from the reference value was considered significant. RESULTS: Reported results for the same blood sample ranged from 4.1 to 5.8%, 5.1 to 8.2%, 6.7 to 9.3%, and 10.1 to 14.7% for the specimens from the nondiabetic subject and the diabetic patients with good, moderate, and poor glycemic control, respectively. The proportion of laboratories with results that differed by > or = 10% bias from the reference value were 39% (12 of 30), 29% (9 of 30), 16% (5 of 30), and 32% (10 of 30), and the proportion reporting results that differed by > or = 1% HbA1c in absolute terms from the reference values were 3% (1 of 30), 6% (2 of 30), 16% (5 of 30), and 23% (7 of 30) for the specimens from the nondiabetic subject and the diabetic patients with good, moderate, and poor glycemic control, respectively. CONCLUSIONS: A substantial degree of interlaboratory variation for GHb measurement exists in Victoria, Australia. This may lead to difficulties in interpretation when GHb is assayed by different laboratories in the same patient over time. Interlaboratory standardization may be achievable by calibration to a standard assigned by a reference laboratory and distributed to all laboratories measuring GHb.


Asunto(s)
Hemoglobina Glucada/análisis , Diabetes Mellitus/sangre , Estudios de Evaluación como Asunto , Humanos , Valores de Referencia , Reproducibilidad de los Resultados , Manejo de Especímenes , Victoria
16.
J Hypertens ; 16(11): 1603-9, 1998 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-9856360

RESUMEN

OBJECTIVE: The purpose of this study was to assess the role of transforming growth factor (TGF)-beta1 in the development of diabetes-associated mesenteric vascular hypertrophy and in the antitrophic effect of angiotensin converting enzyme inhibitors. DESIGN AND METHODS: Streptozotocin-induced diabetic and control Sprague-Dawley rats were randomly allocated to treatment with the angiotensin converting enzyme inhibitor ramipril or to no treatment and were killed 1 or 3 weeks after the streptozotocin injection. Blood was collected and mesenteric vessels removed. Mesenteric vascular weight was measured and TGF-beta1 and alpha1 (type IV) collagen messenger (m)RNA levels were analysed by Northern analysis. Immunohistochemical analyses for TGF-beta1 and type IV collagen were also performed. RESULTS: The diabetic rats had increased mesenteric vessel weight at 3 weeks but not at 1 week and a concomitant rise in mesenteric TGF-beta1 and in alpha1 (type IV) collagen mRNA levels. Ramipril treatment attenuated mesenteric vessel hypertrophy and prevented the increase in TGF-beta1 and alpha1 (type IV) collagen mRNA levels after 3 weeks of diabetes. The immunohistochemical analysis revealed that diabetes was associated with increased TGF-beta1 and type IV collagen protein and extracellular matrix accumulation in mesenteric vessels, and this increase was reduced by ramipril treatment. CONCLUSIONS: These results support the concept that TGF-beta is involved in the changes associated with diabetic vascular disease, and suggest a mechanism by which angiotensin converting enzyme inhibitors exert their antitrophic effects.


Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Colágeno/genética , Angiopatías Diabéticas/genética , Ramipril/farmacología , Factor de Crecimiento Transformador beta/genética , Animales , Glucemia/efectos de los fármacos , Presión Sanguínea/efectos de los fármacos , Northern Blotting , Peso Corporal/efectos de los fármacos , Diabetes Mellitus Experimental/complicaciones , Angiopatías Diabéticas/complicaciones , Angiopatías Diabéticas/metabolismo , Expresión Génica/efectos de los fármacos , Inmunohistoquímica , Masculino , ARN Mensajero/análisis , ARN Mensajero/genética , Ratas , Ratas Sprague-Dawley , Enfermedades Vasculares/complicaciones , Enfermedades Vasculares/genética , Enfermedades Vasculares/metabolismo
17.
Transplantation ; 72(11): 1826-9, 2001 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-11740395

RESUMEN

Cyclosporine nephropathy (CyAN) is a major limiting factor in the otherwise successful widespread use of cyclosporine in solid organ transplant. Transforming growth factor-beta1 (TGF-beta1) has been implicated as an important fibrogenic cytokine in the development of this disease. TGF-beta-inducible gene-H3 (beta(ig)-H3) is a TGF-beta1- induced gene product, which acts as a marker for biologically active TGF-beta1. This study reports TGF-beta1 gene expression and beta(ig)-H3 tissue distribution in non-renal allograft CyAN. Renal tissue from nine patients who had developed CyAN after successful heart or heart-lung transplantation and from four kidneys removed for tumour were analyzed for TGF-beta1 gene expression beta(ig)-H3 protein with reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry, respectively. TGF-beta1 gene expression was increased in CyAN compared to nephrectomy (P<0.0001). Beta(ig)-H3 protein expression was identified in distal convoluted tubular epithelium and parietal glomerular epithelium in CyAN, and not in nephrectomy samples. Expression of TGF-beta1 mRNA was significantly higher in renal tissue from patients not receiving angiotensin converting enzyme inhibitor (ACEI) therapy for hypertension (P<0.05). These findings support the hypothesis that TGF-beta1 is an important cytokine in the development of CyAN, independent of its role in chronic rejection in renal allografts.


Asunto(s)
Ciclosporina/efectos adversos , Proteínas de la Matriz Extracelular , Trasplante de Corazón , Trasplante de Corazón-Pulmón , Inmunosupresores/efectos adversos , Enfermedades Renales/inducido químicamente , Enfermedades Renales/metabolismo , Proteínas de Neoplasias/metabolismo , Factor de Crecimiento Transformador beta/metabolismo , Adulto , Humanos , Riñón/metabolismo , Túbulos Renales Distales/metabolismo , Persona de Mediana Edad , ARN Mensajero/metabolismo , Factor de Crecimiento Transformador beta/genética , Factor de Crecimiento Transformador beta1
18.
Pediatrics ; 94(4 Pt 1): 456-61, 1994 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-7936852

RESUMEN

OBJECTIVE: To compare postnatal growth preceding the sudden infant death syndrome (SIDS) with that of age matched controls. DESIGN: Retrospective case-control study. Each SIDS victim was matched with two controls on date of parental interview, postnatal age, and neighborhood. Clinical and demographic data were collected by parental interview and by review of medical records, and interval body weights were obtained from health visitors' records. STUDY POPULATION: All infants dying of SIDS between 1 May, 1987 and 30 April, 1989 in a geographically defined region consisting of four health districts in Avon and North Somerset in southwest England. Seventy-eight of the 99 SIDS victims and 139 of 156 control infants were included in the final analysis. RESULTS: There was no significant difference between SIDS victims and the controls in either of the two indices of postnatal growth which were analyzed. The mean growth rates (+/- 1 SEM) between birth and the last live weight (age equivalent weight for control infants) were 27.1 +/- 1.0 g/day for the SIDS cases and 28.3 +/- 1.5 g/day for the control infants. The mean growth rate (+/- 1 SEM) between the last two live weights were 31.5 +/- 2.9 and 24.9 +/- 2.1 g/day for the SIDS and control infants, respectively. Stratification of the infants by sex, gestational age, maternal smoking during pregnancy, breast versus bottle feeding, or age at death, did not result in any significant differences between SIDS and controls in either of the indices of postnatal growth rate. The 20 SIDS cases which were excluded from the final analysis did not differ from 78 whose data was analyzed, with regard to established SIDS risk factors, age at death, or postmortem weight. CONCLUSIONS: No difference was found between the postnatal growth of SIDS victims and that of age matched control infants.


Asunto(s)
Trastornos del Crecimiento/epidemiología , Recién Nacido/crecimiento & desarrollo , Vigilancia de la Población , Muerte Súbita del Lactante/epidemiología , Aumento de Peso , Factores de Edad , Inglaterra/epidemiología , Femenino , Trastornos del Crecimiento/complicaciones , Humanos , Lactante , Masculino , Análisis por Apareamiento , Estudios Retrospectivos , Factores de Riesgo , Muerte Súbita del Lactante/etiología
19.
Am J Kidney Dis ; 37(5): 890-9, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11325669

RESUMEN

The aim of this study is to compare the efficacy of an angiotensin-converting enzyme inhibitor with a dihydropyridine calcium channel blocker in preventing progression to macroalbuminuria and/or a decline in renal function in normotensive patients with type 1 diabetes and microalbuminuria. Forty-two patients were randomized to treatment with either perindopril, slow-release nifedipine, or placebo. In the first 3 months, drug dosage was titrated to achieve a decrease in diastolic blood pressure of at least 5 mm HG: Thirty-three patients had a minimum of 24 months' data, and 25 patients were followed up beyond 36 months (mean, 67 +/- 4 months). Patients were studied every 3 months and at the end of the treatment period; those who remained normotensive discontinued therapy and were followed up for an additional 3 months. Baseline geometric mean albumin excretion rates (AERs) were as follows: perindopril, 66 microg/min; nifedipine, 59 microg/min; and placebo, 66 microg/min. During the first 3 years, 7 of the perindopril-treated but none of the placebo or nifedipine-treated patients reverted to normoalbuminuria (P < 0.01). Median AERs at 3 years of treatment in each group were 23 microg/min for perindopril, 122 microg/min for nifedipine, and 112 microg/min for placebo patients (P < 0.01). In patients with more than 3 years' follow-up, median AERs decreased by 45% in the first year and then stabilized in the perindopril group, but increased by 17.6% in the nifedipine group and 27.6% in the placebo group (P < 0.03) in the first year, then increased progressively. In these same patients, there was a significant decline in glomerular filtration rate in the nifedipine group (-7.8 +/- 1.8 mL/min/1.73 m(2)/y), but not in the other two groups (perindopril, -1.0 +/- 1.2 mL/min/1.73 m(2)/y; placebo, -1.3 +/- 1.1 mL/min/1.73 m(2)/y; P = 0.004). At the end of the study, cessation of treatment for 3 months was associated with a doubling of AERs in the perindopril-treated group, but no change in the other two groups (P < 0.001). In conclusion, long-term perindopril therapy is more effective than nifedipine or placebo in delaying the progression of diabetic nephropathy and reducing AER to the normoalbuminuric range (<20 microg/min) in normotensive patients with type 1 diabetes and microalbuminuria.


Asunto(s)
Albuminuria/prevención & control , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Antihipertensivos/uso terapéutico , Bloqueadores de los Canales de Calcio/uso terapéutico , Diabetes Mellitus Tipo 1/complicaciones , Nefropatías Diabéticas/prevención & control , Nifedipino/uso terapéutico , Perindopril/uso terapéutico , Adolescente , Adulto , Anciano , Presión Sanguínea/efectos de los fármacos , Diabetes Mellitus Tipo 1/orina , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Estadística como Asunto
20.
Int J Epidemiol ; 30(6): 1309-13, 2001 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11821335

RESUMEN

BACKGROUND: Hydrocephalus, intracranial calcification and retinochoroiditis are the most common manifestations of tissue damage due to congenital toxoplasmosis, but the effect of prenatal treatment on these outcomes is unclear. We aimed to determine the effect of prenatal treatment for toxoplasmosis on the risk of intracranial and ocular lesions in congenitally infected children at 3 years of age. METHODS: A cohort of mothers identified during pregnancy with toxoplasma infection and their 181 liveborn children with confirmed congenital toxoplasmosis was retrospectively analysed to determine the presence of intracranial and ocular lesions. As few women are not treated, we compared the effects of the treatment potency (pyrimethamine-sulfadiazine versus spiramycin or no treatment), and the timing of treatment, on the risks of intracranial lesions, time to detection of ocular lesions, and detection of any lesions (intracranial or ocular) by 3 years of age. Analyses took account of the gestation at maternal seroconversion. RESULTS: There was no evidence for an effect of pyrimethamine-sulfadiazine on intracranial, ocular or any lesions by 3 years: odds ratio (OR) for any lesions 0.89 (95% CI : 0.41, 1.88). There was no evidence of an effect of delayed treatment on ocular lesions (hazard ratio = 0.69, 95% CI : 0.28, 1.68) or any lesions by 3 years of age (OR = 0.44, 95% CI : 0.16, 1.19). CONCLUSIONS: Our study failed to detect a beneficial effect of early or more potent anti toxoplasma treatment on the risks of intracranial or ocular lesions in children with congenital toxoplasmosis. However, larger, prospective studies, which determine the effect of prenatal treatment on long-term developmental outcomes are required to justify changes in clinical practice.


Asunto(s)
Transmisión Vertical de Enfermedad Infecciosa/prevención & control , Toxoplasmosis Congénita/complicaciones , Antibacterianos/uso terapéutico , Antiprotozoarios/uso terapéutico , Preescolar , Quimioterapia Combinada , Femenino , Humanos , Modelos Logísticos , Macrólidos , Masculino , Atención Posnatal , Embarazo , Complicaciones Parasitarias del Embarazo/tratamiento farmacológico , Complicaciones Parasitarias del Embarazo/epidemiología , Atención Prenatal , Estudios Prospectivos , Riesgo , Toxoplasmosis Cerebral/epidemiología , Toxoplasmosis Cerebral/prevención & control , Toxoplasmosis Congénita/tratamiento farmacológico , Toxoplasmosis Congénita/epidemiología , Toxoplasmosis Ocular/epidemiología , Toxoplasmosis Ocular/prevención & control , Resultado del Tratamiento
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