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1.
Am J Physiol Renal Physiol ; 320(6): F1106-F1122, 2021 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-33938239

RESUMEN

Ksp-cadherin (cadherin-16) is an atypical member of the cadherin superfamily of cell adhesion molecules that is ubiquitously expressed on the basolateral membrane of epithelial cells lining the nephron and the collecting system of the mammalian kidney. The principal aim of the present study was to determine if Ksp-cadherin played a critical role in the development and maintenance of the adult mammalian kidney by generating and evaluating a mouse line deficient in Ksp-cadherin. Ksp-null mutant animals were viable and fertile, and kidneys from both neonates and adults showed no evidence of structural abnormalities. Immunolocalization and Western blot analyses of Na+-K+-ATPase and E-cadherin indicated that Ksp-cadherin is not essential for either the genesis or maintenance of the polarized tubular epithelial phenotype. Moreover, E-cadherin expression was not altered to compensate for Ksp-cadherin loss. Plasma electrolytes, total CO2, blood urea nitrogen, and creatinine levels were also unaffected by Ksp-cadherin deficiency. However, a subtle but significant developmental delay in the ability to maximally concentrate urine was detected in Ksp-null mice. Expression analysis of the principal proteins involved in the generation of the corticomedullary osmotic gradient and the resultant movement of water identified misexpression of aquaporin-2 in the inner medullary collecting duct as the possible cause for the inability of young adult Ksp-cadherin-deficient animals to maximally concentrate their urine. In conclusion, Ksp-cadherin is not required for normal kidney development, but its absence leads to a developmental delay in maximal urinary concentrating ability.NEW & NOTEWORTHY Ksp-cadherin (cadherin-16) is an atypical member of the cadherin superfamily of cell adhesion molecules that is ubiquitously expressed on the basolateral membrane of epithelial cells lining the nephron and the collecting system. Using knockout mice, we found that Ksp-cadherin is in fact not required for kidney development despite its high and specific expression along the nephron. However, its absence leads to a developmental delay in maximal urinary concentrating ability.


Asunto(s)
Cadherinas/metabolismo , Capacidad de Concentración Renal/fisiología , Riñón/crecimiento & desarrollo , Animales , Acuaporina 2/genética , Acuaporina 2/metabolismo , Cadherinas/genética , Regulación del Desarrollo de la Expresión Génica , Riñón/fisiología , Capacidad de Concentración Renal/genética , Masculino , Ratones , Ratones Noqueados , ATPasa Intercambiadora de Sodio-Potasio/genética , ATPasa Intercambiadora de Sodio-Potasio/metabolismo
2.
J Surg Oncol ; 123(5): 1263-1273, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33524184

RESUMEN

BACKGROUND: The association between the imaging response (structural or metabolic) to neoadjuvant chemotherapy (neoCT) before colorectal liver metastasis (CRLM) and survival is unclear. METHOD: A total of 201 patients underwent their first CRLM resection. A total of 94 (47%) patients were treated with neoCT. A multivariable, Cox proportional hazard regression analysis was performed to compare overall survival (OS) and progression-free survival (PFS) between response groups. RESULTS: Multivariable regression analysis of the CT/MRI (n = 94) group showed no difference in survival (OS and PFS) in patients who had stable disease/partial response (SD/PR) or complete response (CR) versus patients who had progressive disease (PD) (OS: HR, 0.36 (95% CI: 0.11-1.19) p = .094, HR, 0.78 (95% CI: 0.13-4.50) p = .780, respectively), (PFS: HR, 0.70 (95% CI: 0.36-1.35) p = .284, HR, 0.51 (0.18-1.45) p = .203, respectively). In the FDG-PET group (n = 60) there was no difference in the hazard of death for patients with SD/PR or CR versus patients with PD for OS or PFS except for the PFS in the small CR subgroup (OS: HR, 0.75 (95% CI: 0.11-4.88) p = .759, HR, 1.21 (95% CI: 0.15-9.43) p = .857), (PFS: HR, 0.34% (95% CI: 0.09-1.22), p = .097, HR, 0.17 (95% CI: 0.04-0.62) p = .008, respectively). CONCLUSION: There was no convincing evidence of association between imaging response to neoCT and survival following CRLM resection.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Quimioterapia Adyuvante/mortalidad , Neoplasias Colorrectales/mortalidad , Neoplasias Hepáticas/mortalidad , Terapia Neoadyuvante/mortalidad , Recurrencia Local de Neoplasia/mortalidad , Tomografía de Emisión de Positrones/métodos , Neoplasias Colorrectales/diagnóstico por imagen , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/patología , Femenino , Estudios de Seguimiento , Humanos , Neoplasias Hepáticas/diagnóstico por imagen , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias Hepáticas/secundario , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/diagnóstico por imagen , Recurrencia Local de Neoplasia/tratamiento farmacológico , Recurrencia Local de Neoplasia/patología , Pronóstico , Estudios Retrospectivos , Tasa de Supervivencia
3.
Ann Oncol ; 30(9): 1472-1478, 2019 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-31250894

RESUMEN

BACKGROUND: In early-stage pancreatic cancer, there are currently no biomarkers to guide selection of therapeutic options. This prospective biomarker trial evaluated the feasibility and potential clinical utility of circulating tumor DNA (ctDNA) analysis to inform adjuvant therapy decision making. MATERIALS AND METHODS: Patients considered by the multidisciplinary team to have resectable pancreatic adenocarcinoma were enrolled. Pre- and post-operative samples for ctDNA analysis were collected. PCR-based-SafeSeqS assays were used to identify mutations at codon 12, 13 and 61 of KRAS in the primary pancreatic tumor and to detect ctDNA. Results of ctDNA analysis were correlated with CA19-9, recurrence-free and overall survival (OS). Patient management was per standard of care, blinded to ctDNA data. RESULTS: Of 112 patients consented pre-operatively, 81 (72%) underwent resection. KRAS mutations were identified in 91% (38/42) of available tumor samples. Of available plasma samples (N = 42), KRAS mutated ctDNA was detected in 62% (23/37) pre-operative and 37% (13/35) post-operative cases. At a median follow-up of 38.4 months, ctDNA detection in the pre-operative setting was associated with inferior recurrence-free survival (RFS) [hazard ratio (HR) 4.1; P = 0.002)] and OS (HR 4.1; P = 0.015). Detectable ctDNA following curative intent resection was associated with inferior RFS (HR 5.4; P < 0.0001) and OS (HR 4.0; P = 0.003). Recurrence occurred in 13/13 (100%) patients with detectable ctDNA post-operatively, including in seven that received gemcitabine-based adjuvant chemotherapy. CONCLUSION: ctDNA studies in localized pancreatic cancer are challenging, with a substantial number of patients not able to undergo resection, not having sufficient tumor tissue for analysis or not completing per protocol sample collection. ctDNA analysis, pre- and/or post-surgery, is a promising prognostic marker. Studies of ctDNA guided therapy are justified, including of treatment intensification strategies for patients with detectable ctDNA post-operatively who appear at very high risk of recurrence despite gemcitabine-based adjuvant therapy.


Asunto(s)
Biomarcadores de Tumor/sangre , ADN Tumoral Circulante/sangre , Neoplasias Pancreáticas/sangre , Proteínas Proto-Oncogénicas p21(ras)/sangre , Anciano , Anciano de 80 o más Años , Quimioterapia Adyuvante/métodos , Desoxicitidina/administración & dosificación , Desoxicitidina/análogos & derivados , Supervivencia sin Enfermedad , Femenino , Humanos , Biopsia Líquida , Masculino , Persona de Mediana Edad , Mutación , Recurrencia Local de Neoplasia/sangre , Recurrencia Local de Neoplasia/tratamiento farmacológico , Recurrencia Local de Neoplasia/patología , Neoplasias Pancreáticas/tratamiento farmacológico , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/cirugía , Pronóstico , Gemcitabina
4.
Eur Radiol ; 29(6): 3100-3107, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30506214

RESUMEN

METHODS: We applied multiparametric MRI to assess changes in liver composition, perfusion and blood flow in 17 patients before direct-acting antiviral (DAA) therapy and after treatment completion (within 12 weeks of last DAA tablet swallowed). RESULTS: We observed changes in hepatic composition indicated by a reduction in both liver longitudinal relaxation time (T1, 35 ± 4 ms), transverse relaxation time (T2, 2.5 ± 0.8 ms; T2* 3.0 ± 0.7 ms), and liver perfusion (28.1 ± 19.7 ml/100 g/min) which we suggest are linked to reduced pro-inflammatory milieu, including interstitial oedema, within the liver. No changes were observed in liver or spleen blood flow, splenic perfusion, or superior mesenteric artery blood flow. CONCLUSION: For the first time, our study has shown that treatment of HCV with DAAs in patients with cirrhosis leads to an acute reduction in liver T1, T2 and T2* and an increase in liver perfusion measured using MR parameters. The ability of MRI to characterise changes in the angio-architecture of patients with cirrhosis after intervention in the short term will enhance our understanding of the natural history of regression of liver disease and potentially influence clinical decision algorithms. KEY POINTS: • DAAs have revolutionised the treatment of hepatitis C and achieve sustained virological response in over 95% of patients, even with liver cirrhosis. • Currently available non-invasive measures of liver fibrosis are not accurate after HCV treatment with DAAs, this prospective single-centre study has shown that MRI can sensitively measure changes within the liver, which could reflect the reduction in inflammation with viral clearance. • The ability of MRI to characterise changes in structural and haemodynamic MRI measures in the liver after intervention will enhance our understanding of the progression/regression of liver disease and could potentially influence clinical decision algorithms.


Asunto(s)
Antivirales/uso terapéutico , Hepatitis C Crónica/diagnóstico por imagen , Hepatitis C Crónica/tratamiento farmacológico , Hígado/diagnóstico por imagen , Adulto , Progresión de la Enfermedad , Femenino , Hepacivirus/aislamiento & purificación , Hepatitis C Crónica/complicaciones , Hepatitis C Crónica/virología , Humanos , Circulación Hepática , Cirrosis Hepática/virología , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Respuesta Virológica Sostenida
5.
Perfusion ; 31(1): 78-86, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25987551

RESUMEN

The high velocity jet from aortic arterial cannulae used during cardiopulmonary bypass potentially causes a "sandblasting" injury to the aorta, increasing the possibility of embolisation of atheromatous plaque. We investigated a range of commonly available dispersion and non-dispersion cannulae, using particle image velocimetry. The maximum velocity of the exit jet was assessed 20 and 40 mm from the cannula tip at flow rates of 3 and 5 L/min. The dispersion cannulae had lower maximum velocities compared to the non-dispersion cannulae. Dispersion cannulae had fan-shaped exit profiles and maximum velocities ranged from 0.63 to 1.52 m/s when measured at 20 mm and 5 L/min. Non-dispersion cannulae had maximum velocities ranging from 1.52 to 3.06 m/s at 20 mm and 5 L/min, with corresponding narrow velocity profiles. This study highlights the importance of understanding the hydrodynamic performance of these cannulae as it may help in selecting the most appropriate cannula to minimize the risk of thromboembolic events or aortic injury.


Asunto(s)
Aorta/lesiones , Enfermedades de la Aorta , Puente Cardiopulmonar/efectos adversos , Catéteres/efectos adversos , Hidrodinámica , Tromboembolia , Aorta/fisiopatología , Enfermedades de la Aorta/etiología , Enfermedades de la Aorta/fisiopatología , Enfermedades de la Aorta/prevención & control , Humanos , Reología , Tromboembolia/etiología , Tromboembolia/fisiopatología , Tromboembolia/prevención & control
6.
Br J Surg ; 102(13): 1726-32, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26492418

RESUMEN

BACKGROUND: Patients presenting with emergency surgical conditions place significant demands on healthcare services globally. The need to improve emergency surgical care has led to establishment of consultant-led emergency surgery units. The aim of this study was to determine the effect of a changed model of service on outcomes. METHODS: A retrospective observational study of all consecutive emergency general surgical admissions in 2009-2012 was performed. A 2-year time frame before and after the establishment of the emergency general surgery (EGS) service was used to determine the number of admissions and operations, emergency department and hospital length of stay, as well as complication rates. RESULTS: The study included 7233 acute admissions. The EGS service managed 4468 patients (61·6 per cent increase) and performed 1804 operations (41·0 per cent increase). The most common diagnoses during the EGS period included acute appendicitis (532, 11·9 per cent), biliary disease (361, 8·1 per cent) and abdominal pain (561, 12·6 per cent). Appendicectomy (536, 29·7 per cent), cholecystectomy (239, 13·2 per cent) and laparotomy (226, 12·5 per cent) were the most commonly performed procedures. In the EGS period, time in the emergency department was reduced (from 8·0 to 6·0 h; P < 0·001), as was length of hospital stay (from 3·0 to 2·0 days; P < 0·001). The number of complications was reduced by 46·8 per cent, from 172 (6·2 per cent) to 147 (3·3 per cent) (P < 0·001), with a 53 per cent reduction in the number of deaths in the EGS period, from 29 (16·9 per cent) to seven (8 per cent) (P = 0·039). CONCLUSION: The establishment of a consultant-led emergency surgical service has been associated with improved provision of care, resulting in timely management and improved clinical outcomes.


Asunto(s)
Dolor Abdominal/cirugía , Consultores , Urgencias Médicas , Servicio de Urgencia en Hospital/organización & administración , Tratamiento de Urgencia/métodos , Procedimientos Quirúrgicos Operativos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos
7.
Br J Surg ; 101(1): e141-6, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24272668

RESUMEN

BACKGROUND: Appendicectomy is a common general surgical emergency procedure and may be used as a surrogate marker to evaluate quality in surgical management. The aim of this study was to assess the outcomes of appendicectomy before and after the introduction of a consultant-led emergency general surgery (EGS) service at a large metropolitan tertiary referral centre. METHODS: A retrospective historical control study was performed that included all adult patients undergoing appendicectomy during two 18-month periods, before and after the introduction of the EGS service. Data collected included patient demographics, use of radiological investigations, time to surgery, length of hospital stay and histopathology findings. Outcome measures were time to surgery, hospital length of stay, use of radiological investigations, negative appendicectomy rate and perforation rate. RESULTS: A total of 675 patients were identified of whom 276 had an appendicectomy before the EGS service was introduced (2008-2009) and 399 after its introduction (2011-2012). The EGS service resulted in an increase in time to surgery (15 versus 18 h; P < 0.001) with no increase in length of hospital stay (3 days for both periods; P = 0.424). An increase in the rate of appendicectomies performed within office hours was seen (54.3 versus 64.4 per cent; P < 0.001), with no significant increase in negative appendicectomy (13.0 versus 15.8 per cent; P = 0.322) or perforation (8.3 versus 5.5 per cent; P = 0.149) rates. The use of preoperative computed tomography reduced from 38.4 to 26.6 per cent (P = 0.001). CONCLUSION: The introduction of a consultant-led EGS service resulted in a decrease in the use of computed tomography and a greater proportion of appendicectomies performed within office hours, with no increase in length of stay. Overall negative appendicectomy and perforation rates did not change.


Asunto(s)
Apendicectomía/métodos , Apendicitis/cirugía , Tratamiento de Urgencia/métodos , Enfermedad Aguda , Adulto , Diagnóstico por Imagen , Urgencias Médicas , Servicio de Urgencia en Hospital/organización & administración , Femenino , Humanos , Tiempo de Internación , Masculino , Estudios Retrospectivos , Tiempo de Tratamiento
8.
Clin Exp Immunol ; 174(2): 265-73, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23841802

RESUMEN

Mannan binding lectin (MBL)-associated serine protease type 1 (MASP-1) has a central role in the lectin pathway of complement activation and is required for the formation of C3 convertase. The activity of MASP-1 in the peripheral blood has been identified previously as a highly significant predictor of the severity of liver fibrosis in hepatitis C virus (HCV) infection, but not in liver disease of other aetiologies. In this study we tested the hypotheses that expression of MASP-1 may promote disease progression in HCV disease by direct activation of hepatic stellate cells (HSCs) and may additionally be up-regulated by HCV. In order to do so, we utilized a model for the maintenance of primary human HSC in the quiescent state by culture on basement membrane substrate prior to stimulation. In comparison to controls, recombinant MASP-1 stimulated quiescent human HSCs to differentiate to the activated state as assessed by both morphology and up-regulation of HSC activation markers α-smooth muscle actin and tissue inhibitor of metalloproteinase 1. Further, the expression of MASP-1 was up-regulated significantly by HCV infection in hepatocyte cell lines. These observations suggest a new role for MASP-1 and provide a possible mechanistic link between high levels of MASP-1 and the severity of disease in HCV infection. Taken together with previous clinical observations, our new findings suggest that the balance of MASP-1 activity may be proinflammatory and act to accelerate fibrosis progression in HCV liver disease.


Asunto(s)
Hepacivirus/inmunología , Células Estrelladas Hepáticas/inmunología , Hepatitis C/inmunología , Cirrosis Hepática/inmunología , Serina Proteasas Asociadas a la Proteína de Unión a la Manosa/metabolismo , Actinas/genética , Actinas/metabolismo , Diferenciación Celular , Células Cultivadas , Lectina de Unión a Manosa de la Vía del Complemento/inmunología , Progresión de la Enfermedad , Hepatitis C/complicaciones , Humanos , Cirrosis Hepática/etiología , Lectina de Unión a Manosa/metabolismo , Serina Proteasas Asociadas a la Proteína de Unión a la Manosa/genética , Serina Proteasas Asociadas a la Proteína de Unión a la Manosa/inmunología , Proteínas Recombinantes/inmunología , Inhibidor Tisular de Metaloproteinasa-1/genética , Inhibidor Tisular de Metaloproteinasa-1/metabolismo , Regulación hacia Arriba
9.
Clin Transplant ; 27(6): E709-14, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24138529

RESUMEN

Delayed graft function (DGF) in kidney transplantation affects adverse outcomes. It remains unclear whether the post-transplant dialysis modality alters perioperative or long-term graft outcomes. We performed a retrospective observational quality initiative at two Canadian renal transplant centers, in which DGF occurred in the recipient, necessitating one of peritoneal dialysis (PD) or hemodialysis (HD). There was no difference in baseline factors between patients with post-transplant PD (n = 14) or HD (n = 63). The use of PD was associated with an increased risk of wound infection/leakage (PD 5/14 vs. HD 6/63, p = 0.024), shorter length of hospitalization (13.7 vs. 18.7 d, p = 0.009) and time requiring dialysis post-operatively (6.5 vs 11.0 d, p = 0.043). There were no differences in readmission to hospital within 6 months (4/14 vs. 23/63, p = 0.759), graft loss (0/14 vs. 2/63, p = 1.000) or acute rejection episodes (1/14 vs. 4/63, p = 1.000) at one yr, and GFR did not differ between the PD or HD groups at 30 d (35.7 vs. 33.8 mL/min/m(2), p = 0.731), six months (46.9 vs. 45.5 mL/min/m(2), p = 0.835) or one yr (46.6 vs. 44.5 mL/min/m(2), p = 0.746). Further research is needed to determine which transplant patients are most appropriate to undergo PD catheter removal at the time of transplantation.


Asunto(s)
Funcionamiento Retardado del Injerto/terapia , Fallo Renal Crónico/cirugía , Trasplante de Riñón , Diálisis Peritoneal , Diálisis Renal , Femenino , Estudios de Seguimiento , Tasa de Filtración Glomerular , Rechazo de Injerto/prevención & control , Supervivencia de Injerto , Humanos , Pruebas de Función Renal , Masculino , Persona de Mediana Edad , Pronóstico , Factores de Riesgo
10.
Nephron Clin Pract ; 124(1-2): 113-8, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24192796

RESUMEN

BACKGROUND: Nephrologists need effective screening tools to identify hemodialysis patients at elevated risk for sudden cardiac death, the leading cause of death in this population. QTc intervals longer than 450 ms in males and 470 ms in females, measured by the gold standard tangent method (trueQTc), are prolonged and increase sudden cardiac death in healthy populations and patients with long QT syndrome. METHODS: We performed a retrospective ECG and chart review of hemodialysis patients. Our first objective was to determine if machine-measured QTc intervals (macQTc) could be used to identify dialysis patients with prolonged trueQTc. Our second objective was to determine at what macQTc could prolonged trueQTc be confidently diagnosed. RESULTS: macQTc differed from the trueQTc by an average of 16.54 ms, and by at least 20 ms in 46.8, 36.1, 53.6, 50.0 and 57.1% of all, short-hours daily hemodialysis, intermittent conventional hemodialysis, frequent nocturnal hemodialysis and intermittent nocturnal hemodialysis patients, respectively. The positive predictive value, negative predictive value, sensitivity and specificity of prolonged macQTc predicting prolonged trueQTc was 57.6, 92.6, 79.1 and 81.8%, respectively. Thus, macQTc is inaccurate at predicting the gold standard trueQTc in hemodialysis patients. macQTc greater than 480 ms in hemodialysis patients predicts trueQTc prolongation with a positive predictive value of 95.2%, but with a low sensitivity of 32.3%. CONCLUSION: In hemodialysis patients, ECG macQTc intervals are insufficiently sensitive or specific to predict prolonged trueQTc intervals, unless >480 ms.


Asunto(s)
Errores Diagnósticos , Electrocardiografía/métodos , Síndrome de QT Prolongado/diagnóstico , Síndrome de QT Prolongado/etiología , Diálisis Renal , Insuficiencia Renal Crónica/complicaciones , Insuficiencia Renal Crónica/terapia , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Insuficiencia Renal Crónica/diagnóstico , Reproducibilidad de los Resultados , Estudios Retrospectivos , Sensibilidad y Especificidad
11.
Gen Comp Endocrinol ; 171(1): 39-45, 2011 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-21187096

RESUMEN

Brushtail possums exhibit a distinct preovulatory pattern of prolactin (Prl) secretion suggesting that Prl is involved in normal reproductive function. In some mammals, Prl is essential for corpus luteum (CL) function and/or modulation of steroidal effects on hypothalamic-pituitary activity. The aim of this study was to test the effects of biologically active recombinant possum Prl (recPosPrl) on both pituitary gland and CL function in possums. To confirm biological activity, administration of recPosPrl-N2C1 (10 µg) resulted in an 18-fold stimulation (P<0.05) of progesterone (P(4)) production by possum granulosa cells in vitro. Based on these findings, minipumps containing either recPosPrl-N2C1 (n=10) or saline (n=8) were inserted into lactating female possums. The expression levels of pituitary-derived PRL, LHB, FSHB and GNRHR and CL-derived LHR mRNA were quantified. Following a resumption of reproductive activity, no differences in ovulation incidence or plasma Prl concentrations were observed. Plasma Prl levels were less variable (P<0.001) in Prl-treated possums, confirming a self-regulatory role for Prl in this species. There was a marked down-regulation (P<0.001) of FSHB mRNA at the mid-luteal stage in Prl-treated possums, whereas mean PRL, LHB, GNRHR and LHR mRNA expression levels were not different between experimental groups. Plasma P(4) concentrations were not different (P=0.05) in Prl-treated possums, although tended to be higher in the peri-ovulatory and early-luteal phase. We conclude in the brushtail possum that Prl is self-regulated via a short-feedback loop common to all mammals studied and is able to modulate FSHB expression probably at the level of the hypothalamus and/or pituitary gland.


Asunto(s)
Hormona Folículo Estimulante/genética , Sistema Hipotálamo-Hipofisario/efectos de los fármacos , Sistema Hipotálamo-Hipofisario/metabolismo , Hipófisis/metabolismo , Prolactina/farmacología , Trichosurus/metabolismo , Animales , Cuerpo Lúteo/efectos de los fármacos , Cuerpo Lúteo/metabolismo , Femenino , Hormona Liberadora de Gonadotropina/genética , Células de la Granulosa/efectos de los fármacos , Células de la Granulosa/metabolismo , Hormona Luteinizante de Subunidad beta/genética , Hipófisis/efectos de los fármacos , Reacción en Cadena de la Polimerasa , Progesterona/genética , Radioinmunoensayo , Receptores de HL/genética , Trichosurus/genética
12.
J Exp Med ; 164(1): 104-12, 1986 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-3487611

RESUMEN

A monocyte-derived factor with IL-1-like properties has recently been shown to cause resorption of bone in organ culture. We have investigated the action of IL-1 on disaggregated populations of osteoclasts, incubated alone or in the presence of osteoblastic cells, in an attempt to identify the target cell for IL-1 in bone, and to elucidate the mechanism by which IL-1 induces osteoclastic resorption. Osteoclasts were disaggregated from neonatal rat long bones and incubated on slices of human femoral cortical bone. Under these conditions, the majority of osteoclasts form distinctive excavations in the bone surface within 24 h, the volume of which can be quantified by computer-assisted morphometric and stereophotogrammetic techniques. IL-1 had no effect on bone resorption by osteoclasts alone, but when incubated in the presence of calvarial cells or cloned osteosarcoma cells, it induced a 3.8 (+/- 0.38)-fold increase in osteoclastic bone resorption, with significant enhancement at concentrations of greater than or equal to 30 pg/ml. The osteoblastic populations themselves did not resorb bone. The mechanism by which osteoblastic cells stimulate osteoclasts did not appear to depend upon PG synthesis; nor could we detect a diffusible substance in the medium of stimulated cocultures. These results indicate that IL-1 stimulates bone resorption through a primary action on osteoblasts, which are induced by IL-1 to transmit a short-range signal that stimulates osteoclastic bone resorption.


Asunto(s)
Resorción Ósea , Interleucina-1/fisiología , Osteoblastos/fisiología , Osteoclastos/fisiología , Animales , Agregación Celular , Células Cultivadas , Femenino , Fibroblastos/fisiología , Ratas , Ratas Endogámicas , Cráneo
13.
J Toxicol Environ Health A ; 73(16): 1075-89, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20574910

RESUMEN

Studies suggested that exposure to agricultural pesticides may affect male fertility. Pyrethroids are widely used pesticides due to their insecticidal potency and low mammalian toxicity. A recombinant yeast assay system incorporating the human alpha-estrogen receptor was used to analyze the estrogenicity of a range of readily available pyrethroid pesticides. The commercial product Ripcord Plus showed estrogenic activity by this assay. To determine whether pyrethroid compounds might exert an effect on male fertility, mouse Sertoli cells were exposed in vitro to the endogenous estrogen, 17beta-estradiol, and selected estrogenic pyrethroids. Following exposure, transcript levels of the alpha- and beta-estrogen receptors were assessed. Exposure of Sertoli cells to the pyrethroid compounds, both at high and at low published serum concentrations, affected the expression of the two estrogen receptors; however, the influence on estrogen receptor gene expression was different from the effect from exposure to 17beta-estradiol. These results from our model systems suggest that (1) estrogenic pyrethroid pesticides affect the estrogen receptors, and therefore potentially the endocrine system, in a different manner from that of endogenous estrogen, and (2) should cells in the male testes be exposed to pyrethroid pesticides, male fertility may be affected through molecular mechanisms involving estrogen receptors.


Asunto(s)
Estradiol/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Plaguicidas/farmacología , Piretrinas/farmacología , Receptores de Estrógenos/genética , Células de Sertoli/efectos de los fármacos , Transcripción Genética/efectos de los fármacos , Animales , Bioensayo , Receptor alfa de Estrógeno/metabolismo , Fertilidad/efectos de los fármacos , Fertilidad/fisiología , Humanos , Masculino , Ratones , Plaguicidas/toxicidad , Piretrinas/toxicidad , Ratas , Células de Sertoli/citología , Células de Sertoli/metabolismo , Testículo/efectos de los fármacos , Testículo/metabolismo , Células Tumorales Cultivadas , Levaduras/metabolismo
14.
J Laryngol Otol ; : 1-5, 2020 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-33016256

RESUMEN

BACKGROUND: Post-tonsillectomy bleeding is the most frequent complication of tonsillectomy. Inherited platelet function disorders have an estimated prevalence of 1 per cent. Any association between post-tonsillectomy bleeds and undiagnosed inherited platelet function disorders has not been investigated before. OBJECTIVES: To assess the prevalence of inherited platelet function disorders in a cohort of post-tonsillectomy bleed patients. METHODS: An observational cohort study was conducted using hospital digital records. Platelet function analyser 100 ('PFA-100') closure time was tested on post-tonsillectomy bleed patients who presented to hospital. RESULTS: Between 2013 and 2017, 9 of 91 post-tonsillectomy bleed patients who underwent platelet function analyser 100 testing (9.89 per cent) had positive results. Five patients (5.49 per cent) had undiagnosed inherited platelet function disorders. Four patients had false positive results secondary to a non-steroidal anti-inflammatory drug effect (specificity of 95.3 per cent) proven by repeat testing six weeks later, off medication. The false negative rate was 0 per cent. CONCLUSION: The prevalence of inherited platelet function disorders in our post-tonsillectomy bleed cohort is five-fold higher than in the general population. Platelet function analyser 100 testing when patients present with a post-tonsillectomy bleed allows management of their inherited platelet function disorder.

15.
Reproduction ; 137(1): 129-40, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18818271

RESUMEN

In eutherian mammals, the gonadotrophins (LH and FSH) are synthesized and stored in gonadotroph cells under the regulation of multiple mechanisms including GnRH. Very little is known about the regulation of gonadotrophin secretion and storage in pituitary glands of marsupials. This study revealed, using quantitative PCR and heterologous RIA techniques, that LHB mRNA expression levels remained constant over the oestrous cycle, regardless of the presence of a preovulatory LH surge, which is characteristic of a hormone secreted under regulation. Our sampling regime was unable to detect pulses of LH during the follicular phase, although GNRHR mRNA levels had increased at this time. Pulses of LH were, however, detected in the luteal phase of cycling females, in anoestrus females and in males. There was a positive correlation between gene expression of FSHB and plasma levels of FSH at different stages of the oestrous cycle and no pulses of FSH were detected at any time; all characteristics of a hormone secreted via the constitutive pathway. Using in situ hybridisation and immunohistochemistry methods, we determined that mRNA expression of LHB and FSHB, and protein storage of gonadotrophins exhibited a similar pattern of localisation within the pituitary gland. Additionally, sexual dimorphism of gonadotroph populations was evident. In summary, these findings are similar to that reported in eutherians and considering that marsupial evolution diverged from eutherians over 100 million years ago suggests that the regulation of gonadotrophins is highly conserved indeed.


Asunto(s)
Evolución Biológica , Hormona Folículo Estimulante de Subunidad beta/genética , Hormona Luteinizante de Subunidad beta/genética , Hipófisis/metabolismo , Receptores LHRH/genética , Trichosurus/metabolismo , Animales , Femenino , Hormona Folículo Estimulante de Subunidad beta/análisis , Fase Folicular , Expresión Génica , Hormona Liberadora de Gonadotropina/metabolismo , Inmunohistoquímica , Fase Luteínica , Hormona Luteinizante de Subunidad beta/análisis , Hipófisis/química , ARN Mensajero/análisis , Radioinmunoensayo/métodos , Receptores LHRH/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos
16.
Science ; 286(5447): 2134-7, 1999 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-10591640

RESUMEN

High-resolution altimetric data define the detailed topography of the northern lowlands of Mars, and a range of data is consistent with the hypothesis that a lowland-encircling geologic contact represents the ancient shoreline of a large standing body of water present in middle Mars history. The contact altitude is close to an equipotential line, the topography is smoother at all scales below the contact than above it, the volume enclosed by this contact is within the range of estimates of available water on Mars, and a series of extensive terraces parallel the contact in many places.


Asunto(s)
Evolución Planetaria , Medio Ambiente Extraterrestre , Marte , Agua , Océanos y Mares
17.
Intern Med J ; 39(1): 32-7, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18422561

RESUMEN

BACKGROUND: Endoscopic ultrasound (EUS) with fine-needle aspiration (FNA) is increasingly being used in the staging algorithm for pancreatic carcinoma. This allows for a tissue diagnosis, which was previously difficult to obtain. The aim of this study is to assess the utility of EUS-FNA in establishing the diagnosis of solid pancreatic mass lesions in an Australian population. METHODS: A retrospective review of the EUS databases of St Vincent's Hospital Melbourne and Western Hospital, Melbourne from November 2002 to May 2006 was undertaken. The focus was on patients with a solid pancreatic mass who underwent EUS-FNA. Surgical pathology or long-term follow up was used to identify false-positive or false-negative results. RESULTS: EUS was undertaken to investigate a solid pancreatic or distal common bile duct mass lesion in 155 patients. Seventy-two of these underwent EUS-guided FNA. Mean age was 68 years. A positive tissue diagnosis of malignancy could be made in 55 (76%). Nine (13%) had benign histology, with 8 (11%) having inadequate tissue obtained from FNA. A later tissue diagnosis of carcinoma was made in eight of those with either benign or inadequate histology, although in all cases there were EUS features diagnostic of malignancy, with FNA limited by technical difficulties. The overall utility of EUS-FNA showed a sensitivity of 87%, specificity 100%, positive predictive value 100%, negative predictive value 52% and overall accuracy 89%. CONCLUSION: EUS-FNA gives a high return for histological diagnosis of solid pancreatic mass lesions and should be part of the standard management algorithm for pancreatic carcinoma.


Asunto(s)
Biopsia con Aguja Fina/métodos , Endosonografía , Neoplasias Pancreáticas/patología , Adenocarcinoma/patología , Anciano , Neoplasias del Conducto Colédoco/patología , Femenino , Humanos , Masculino , Estudios Retrospectivos , Sensibilidad y Especificidad
18.
Can J Kidney Health Dis ; 6: 2054358119887154, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31798926

RESUMEN

BACKGROUND: Chronic kidney disease (CKD) associates with a significant health care burden with a disproportionate impact on indigenous persons or people living in remote areas. Although screening programs have expanded in these communities, there remains a paucity of evidence-based interventions to enhance clinical renal outcomes in these populations. OBJECTIVE: The objective of this study was to identify evidence-based interventions to enhance renal outcomes in these populations. DESIGN: A scoping review was conducted for studies in the Cochrane, MEDLINE, and Embase databases and from major nephrology meetings. SETTING: Chronic kidney disease, including those on dialysis. PATIENTS: Remote or indigenous populations. MEASUREMENTS: Studies that performed an intervention that was followed by measurement of renal outcomes or patient-centered outcomes (ie, quality of life) were included. METHODS: All studies were described by study type, intervention, and clinical outcome, and trends were identified by both authors. Meta-analysis was not conducted due to study heterogeneity. RESULTS: Thirty-two studies met inclusion criteria, only 2 (6.3%) of which were randomized controlled trials. Intervention types included multidisciplinary (34.4%), satellite (32.3%), telehealth (25.0%), or other (9.4%). All multidisciplinary interventions were performed in the CKD (non-dialysis) setting and reported improved patient travel time, waiting time, quality of life, kidney function, proteinuria, and blood pressure. Telehealth interventions improved program cost, patient attendance, hospitalization, and quality of life. Satellite interventions were performed in the hemodialysis setting, with 1 study evaluating acute hemodialysis. Satellite interventions improved patient travel time, dialysis clearance, quality of life, and survival, but increased program costs. LIMITATIONS: The study was restricted to interventional trials assessing clinical outcomes and to studies in developed countries, which likely excluded some research contributing to this field. CONCLUSIONS: There is significant heterogeneity among studies of interventions for patients with CKD who are indigenous or live remotely. Interventions were more likely to be successful when the remote or indigenous community was included in program development, with a culturally safe approach. More large, high-quality studies are needed to identify effective interventions to enhance clinical renal outcomes in indigenous or remote populations. TRIAL REGISTRATION: This trial is registered under PROSPERO, Registration Number 128453.


CONTEXTE: L'insuffisance rénale chronique (IRC) s'accompagne d'un fardeau de santé dont les répercussions touchent de façon disproportionnée les populations autochtones et les résidents des régions éloignées. Bien que les programmes de dépistage se soient répandus dans ces communautés, peu d'interventions fondées sur des données probantes et visant l'amélioration des issues rénales sont en place dans ces populations. OBJECTIF: Répertorier les interventions fondées sur des données probantes et visant l'amélioration des issues rénales dans ces populations. TYPE D'ÉTUDE: Une revue de cadrage menée dans les bases de données Cochrane, Medline et Embase, et à partir des principales conférences en néphrologie. CADRE: L'insuffisance rénale chronique, incluant les patients dialysés. SUJETS: Des patients autochtones ou résidents de régions éloignées. MESURES: Ont été incluses les études qui avaient procédé à une intervention suivie de la mesure des issues rénales ou des résultats axés sur le patient (ex. qualité de vie). MÉTHODOLOGIE: Les études ont été définies par le type d'étude, l'intervention et les résultats cliniques. Les tendances ont été déterminées par les auteurs. L'hétérogénéité des études n'a pas permis de procéder à une méta-analyse. RÉSULTATS: Trente-deux études satisfaisaient les critères d'inclusion, dont seulement deux (6,3 %) étaient des essais contrôlés à répartition aléatoire. L'intervention était multidisciplinaire (34,4 %), satellite (32,3 %), en télésanté (25,0 %) ou autre (9,4 %). Toutes les interventions multidisciplinaires avaient été faites en contexte d'IRC (sans dialyse) et avaient amélioré le temps de déplacement, le temps d'attente, la qualité de vie, la fonction rénale, la protéinurie et la pression artérielle du patient. Les interventions en télésanté avaient permis de réduire les coûts du programme et le nombre d'hospitalisations, tout en améliorant la participation du patient et sa qualité de vie. Les interventions satellites avaient été menées en contexte d'hémodialyse, et l'une d'elles évaluait l'hémodialyse aigüe. Les interventions satellites avaient amélioré la clairance par dialyse, ainsi que le temps de déplacement, la qualité de vie et la survie du patient, mais occasionnaient des coûts plus élevés. LIMITES: L'étude se limitait à des essais sur le terrain analysant les résultats cliniques et à des études en pays développés, ce qui a probablement exclu certaines études contribuant à ce domaine. CONCLUSION: On observe une importante hétérogénéité dans les études analysant les interventions en IRC tournées vers les patients d'origine autochtone ou de régions éloignées. Les interventions avaient plus de chances de réussite si les populations visées participaient à l'élaboration du programme, et si elles s'inscrivaient dans une approche respectueuse des valeurs culturelles. Des études robustes et de plus grande envergure sont nécessaires pour cibler les interventions qui permettent d'améliorer les issues rénales cliniques chez les populations autochtones ou éloignées.

19.
J Viral Hepat ; 15(4): 271-8, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18086181

RESUMEN

Evidence for efficacy of established treatment guidelines for chronic hepatitis C virus (HCV) disease is based on multinational randomized controlled trials (RCTs). Strategies for managing HCV, however, require an assessment of the effectiveness of intervention in routine clinical practice. We report the outcomes of combination therapy in a large cohort of HCV-infected individuals in the UK. A total of 347 (113 genotype 1, 234 genotype non-1) patients were treated with pegylated interferon and ribavirin according to current guidelines. Forty-two (37.2%) of those with genotype 1 infection and 164 (70.1%) with genotype non-1 infection achieved sustained viral response (SVR). Thirty-nine (11%) patients withdrew from treatment. In addition to viral genotype, factors predictive of a response to therapy were age at start of treatment and disease stage on pretreatment liver biopsy. Multivariate regression analysis demonstrated that the effects of age [odds ratio 0.5; 95% confidence interval (0.31-0.82) per 10-year increment (P = 0.006)] were confined to genotype 1 disease. In order to further inform the management of the individual patient, a multivariate logistic model was used to predict the probability of SVR for subgroups defined by disease stage, genotype and age at commencement of therapy. This model revealed striking differences in predicted response rates between subgroups and provided a strong rationale for early treatment, particularly for those with genotype 1 disease. Our study demonstrates that results comparable with those of RCTs can be achieved in clinical practice, and suggests that prediction of response rates based on probability modelling will provide a valuable adjunct to individual patient management.


Asunto(s)
Antivirales/uso terapéutico , Hepatitis C Crónica/tratamiento farmacológico , Interferón-alfa/uso terapéutico , Polietilenglicoles/uso terapéutico , Ribavirina/uso terapéutico , Adulto , Factores de Edad , Quimioterapia Combinada , Femenino , Predicción , Genotipo , Hepacivirus/clasificación , Hepacivirus/genética , Hepacivirus/aislamiento & purificación , Hepatitis C Crónica/patología , Hepatitis C Crónica/virología , Humanos , Interferón alfa-2 , Hígado/patología , Masculino , Persona de Mediana Edad , Proteínas Recombinantes , Resultado del Tratamiento , Reino Unido , Viremia
20.
Xenobiotica ; 38(12): 1500-17, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18989830

RESUMEN

Induction of cytochrome P450 (CYP) 1A2, CYP2B6, and CYP3A4 by 22 prototypical inducers was evaluated in the Fa2N-4 immortalized human hepatic cell line. To facilitate this a duplex one-step quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) assay for CYP1A2 and CYP3A4 and a substrate cassette allowing simultaneous monitoring of CYP1A2, CYP2B6, CYP2C9, and CYP3A4 activity were developed. CYP1A2 messenger RNA (mRNA) and activity were induced by the prototypical aryl hydrocarbon receptor (AhR) ligand beta-naphthoflavone (E(max) = 217- and 11-fold, respectively, and EC(50) = 8 microM). CYP3A4 mRNA and activity were induced by the prototypical pregnane X receptor (PXR) ligands, rifampicin (E(max) = 36- and 6-fold, respectively, and EC(50) = 4 microM) and phenobarbital (E(max) = 12- and 4-fold, respectively, and EC(50) = 205 microM). No induction of CYP2B6 was detected with several prototypical constitutive androstane receptor (CAR) ligands. A large mRNA-activity E(max) ratio was observed for some time-dependent inhibitors of CYP3A4, whereas EC(50) determinations appeared to be independent of the endpoint. In conclusion, Fa2N-4 cells are a good surrogate for primary human hepatocytes for assessing AhR and PXR-mediated CYP1A2 and CYP3A4 induction, respectively, but not for CAR-mediated CYP2B6 induction. The sensitive and selective methodologies presented in this paper afford maximal data generation and enhanced throughput capability and are readily transferable to primary human hepatocytes or alternate cellular systems.


Asunto(s)
Sistema Enzimático del Citocromo P-450/genética , Hidrocarburo de Aril Hidroxilasas/genética , Hidrocarburo de Aril Hidroxilasas/metabolismo , Línea Celular , Citocromo P-450 CYP1A2/genética , Citocromo P-450 CYP1A2/metabolismo , Citocromo P-450 CYP2B6 , Citocromo P-450 CYP2C9 , Citocromo P-450 CYP3A/genética , Citocromo P-450 CYP3A/metabolismo , Sistema Enzimático del Citocromo P-450/metabolismo , Hepatocitos/metabolismo , Humanos , Hígado/metabolismo , Oxidorreductasas N-Desmetilantes/genética , Oxidorreductasas N-Desmetilantes/metabolismo , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
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