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1.
Opt Express ; 30(12): 20943-20951, 2022 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-36224827

RESUMEN

Mode-locked vertical external-cavity semiconductor lasers (VECSELs) are a wavelength-versatile laser that relies on a semiconductor saturable absorber mirror (SESAM) to initiate pulsed emission while simultaneously significantly influencing the pulse's properties. A SESAM can be characterized using a nonlinear reflectivity setup, realized here in the red spectral range around 660 nm and achieving a moderate peak-to-peak variation of 0.17%. We use our home-built mode-locked VECSEL to reach a high maximum fluence up to 430 µJ/cm2 with strongly chirped 7.5 ps pulses. This allows the first-of-its-kind characterization of GaInP quantum well SESAMs, thereby revealing saturation fluences of 38 µJ/cm2 and 34 µJ/cm2 with modulation depths of 5% and 10.3% for SESAMs comprising one or two active quantum wells, respectively. For all structures, a nonsaturable loss of 2.8% is found and attributed to scattering loss.

2.
Diabet Med ; 37(2): 174-186, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31006133

RESUMEN

Epidemiological studies consistently demonstrate that lowered serum testosterone is not only common in men with established Type 2 diabetes, but also predicts future diabetic risks and increased mortality. Preclinical studies report plausible mechanisms by which low testosterone could mediate dysglycaemia. Exogenous testosterone treatment consistently reduces fat mass, increases muscle mass and improves insulin resistance in some studies, but the majority of currently available randomized controlled trials (RCTs) do not report a consistent glycaemic benefit. In men with diabetes, testosterone treatment effects on androgen deficiency-like clinical features are inconsistent, and effects on sexual dysfunction may be attenuated compared with men without diabetes. The long-term risks of testosterone treatment in older men without medical disease of the hypothalamic-pituitary-testicular axis are not known. Current RCTs are not definitive, owing to their small size, short duration and enrolment of men with mostly relatively good baseline glycaemic control not specifically selected for the presence of androgen deficiency symptoms. Although large, well-designed clinical trials are needed, given the benefit-risk ratio of testosterone treatment is not well understood, routine serum testosterone testing or testosterone treatment of asymptomatic men with Type 2 diabetes is currently not recommended. Carefully selected, symptomatic men with low testosterone who are informed of the lack of high-level evidence regarding the long-term benefits and risks of this approach may be offered a trial of testosterone treatment in combination with lifestyle measures, weight loss and optimization of comorbidities.


Asunto(s)
Diabetes Mellitus Tipo 2/metabolismo , Hipogonadismo/metabolismo , Resistencia a la Insulina , Obesidad/metabolismo , Testosterona/deficiencia , Tejido Adiposo/metabolismo , Andrógenos/uso terapéutico , Glucemia/metabolismo , Composición Corporal , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Disfunción Eréctil/complicaciones , Disfunción Eréctil/tratamiento farmacológico , Disfunción Eréctil/metabolismo , Terapia de Reemplazo de Hormonas , Humanos , Hipoglucemiantes/uso terapéutico , Hipogonadismo/complicaciones , Hipogonadismo/tratamiento farmacológico , Libido , Masculino , Obesidad/complicaciones , Medición de Riesgo , Testosterona/uso terapéutico , Resultado del Tratamiento
3.
Climacteric ; 22(6): 589-595, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-30896255

RESUMEN

Women with early, estrogen receptor-positive breast cancer are treated with adjuvant endocrine therapy, using aromatase inhibitors or selective estradiol receptor modulators such as tamoxifen, to deprive breast tissue from the deleterious effects of estradiol action, hence improving long-term prognosis. Aromatase inhibitors and, in premenopausal women, tamoxifen accelerate bone loss and increase fracture risk. Therefore, all women commencing endocrine therapy need a targeted work-up to assess the baseline fracture risk, and monitoring of bone health during endocrine therapy should be individualized based on this baseline risk. While high-level evidence specific to early breast cancer is lacking, non-pharmacologic measures to maintain optimal bone health such as weight-bearing exercise and calcium and vitamin D sufficiency should be implemented in all women. Antiresorptive treatment should be initiated in all women with preexisting fragility fractures (including vertebral morphometric fractures) and should be considered in women with areal bone mineral density (BMD) T-scores < -2.0 (or Z-scores in women aged <50 years) or those experiencing rapid bone loss (≥5% per year), taking into consideration the baseline BMD and other risk factors for fracture. Further clinical trial evidence is required to provide definitive guidance regarding criteria to initiate antiresorptive treatment, choice of agents, and duration of treatment, taking into account potential oncologic benefits of antiresorptive therapy on breast cancer-related outcomes.


Asunto(s)
Neoplasias de la Mama/tratamiento farmacológico , Supervivientes de Cáncer , Fracturas Óseas/prevención & control , Tamoxifeno/efectos adversos , Inhibidores de la Aromatasa/efectos adversos , Inhibidores de la Aromatasa/farmacología , Densidad Ósea/efectos de los fármacos , Conservadores de la Densidad Ósea/uso terapéutico , Femenino , Fracturas Óseas/inducido químicamente , Humanos , Factores de Riesgo , Tamoxifeno/farmacología
4.
Osteoporos Int ; 29(7): 1665-1670, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29666893

RESUMEN

A 74-year-old man presented to the Andrology Clinic for management of potential complications of androgen deprivation therapy for prostate cancer. He had a rising prostate-specific antigen with a concurrent rise in alkaline phosphatase and bone remodeling markers. This was despite treatment with a radical prostatectomy, androgen deprivation, and anti-resorptive therapy. A follow-up dual-energy X-ray absorptiometry scan revealed a marked increase in his bone mineral density at both the lumbar spine and femoral neck. This increase, especially in the context of rising bone remodeling markers, was unlikely due to the effect of anti-resorptive therapy alone. Subsequent whole-body bone scintigraphy demonstrated a "superscan" phenomenon which is characterized by uniform and avid tracer retention throughout the skeleton, in this case due to widespread skeletal metastasis, so that the usual physiological uptake in the kidneys is no longer observed and can be misinterpreted as a "normal" scan if the absence of the kidneys is not recognized. This case highlights the importance of considering diffuse metastatic disease when there is a rapid increase in bone mineral density, even in individuals treated with anti-resorptive therapy.


Asunto(s)
Conservadores de la Densidad Ósea/uso terapéutico , Densidad Ósea/fisiología , Osteoporosis/diagnóstico por imagen , Neoplasias de la Próstata/tratamiento farmacológico , Neoplasias de la Próstata/fisiopatología , Absorciometría de Fotón/métodos , Anciano , Antagonistas de Andrógenos/efectos adversos , Neoplasias Óseas/diagnóstico por imagen , Neoplasias Óseas/fisiopatología , Neoplasias Óseas/secundario , Cuello Femoral/fisiopatología , Humanos , Vértebras Lumbares/fisiopatología , Masculino , Osteoporosis/inducido químicamente , Osteoporosis/fisiopatología , Prostatectomía , Cintigrafía
5.
Int J Obes (Lond) ; 41(3): 420-426, 2017 03.
Artículo en Inglés | MEDLINE | ID: mdl-28028318

RESUMEN

BACKGROUND: Obese men commonly have reductions in circulating testosterone and report symptoms consistent with androgen deficiency. We hypothesized that testosterone treatment improves constitutional and sexual symptoms over and above the effects of weight loss alone. METHODS: We conducted a pre-specified analysis of a randomized double-blind, placebo-controlled trial at a tertiary referral center. About 100 obese men (body mass index (BMI)⩾30 kg m-2) with a repeated total testosterone level ⩽12 nmol l-1 and a median age of 53 years (interquartile range 47-60) receiving 10 weeks of a very-low-energy diet (VLED) followed by 46 weeks of weight maintenance were randomly assigned at baseline to 56 weeks of intramuscular testosterone undecanoate (n=49, cases) or matching placebo (n=51, controls). Pre-specified outcomes were the between-group differences in Aging Male Symptoms scale (AMS) and international index of erectile function (IIEF-5) questionnaires. RESULTS: Eighty-two men completed the study. At study end, cases showed significant symptomatic improvement in AMS score, compared with controls, and improvement was more marked in men with more severe baseline symptoms (mean adjusted difference (MAD) per unit of change in AMS score -0.34 (95% confidence interval (CI) -0.65, -0.02), P=0.04). This corresponds to improvements of 11% and 20% from baseline scores of 40 and 60, respectively, with higher scores denoting more severe symptoms. Men with erectile dysfunction (IIEF-5⩽20) had improved erectile function with testosterone treatment. Cases and controls lost the same weight after VLED (testosterone -12.0 kg; placebo -13.5 kg, P=0.40) and maintained this at study end (testosterone -11.4 kg; placebo -10.9 kg, P=0.80). The improvement in AMS following VLED was not different between the groups (-0.05 (95% CI -0.28, 0.17), P=0.65). CONCLUSIONS: In otherwise healthy obese men with mild to moderate symptoms and modest reductions in testosterone levels, testosterone treatment improved androgen deficiency symptoms over and above the improvement associated with weight loss alone, and more severely symptomatic men achieved a greater benefit.


Asunto(s)
Andrógenos/uso terapéutico , Dieta Reductora , Terapia de Reemplazo de Hormonas , Hipogonadismo/tratamiento farmacológico , Hipogonadismo/fisiopatología , Obesidad/fisiopatología , Testosterona/uso terapéutico , Envejecimiento , Andrógenos/sangre , Andrógenos/deficiencia , Australia/epidemiología , Depresión , Dieta Reductora/efectos adversos , Método Doble Ciego , Humanos , Hipogonadismo/etiología , Hipogonadismo/psicología , Libido/fisiología , Masculino , Persona de Mediana Edad , Obesidad/sangre , Obesidad/complicaciones , Obesidad/psicología , Calidad de Vida , Testosterona/sangre , Resultado del Tratamiento
6.
Int J Obes (Lond) ; 40(8): 1325-8, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27003112

RESUMEN

Quantification of abdominal visceral adipose tissue (VAT) is important to understand obesity-related comorbidities. We hypothesized that dual X-ray absorptiometry (DXA) measurements of VAT would correlate with traditional gold standards of magnetic resonance imaging (MRI) and computed tomography (CT) in older men. Deming regression and Bland-Altman plots were used to assess the agreement between VAT measured simultaneously by DXA and MRI (n=95) in a cohort of older males participating in a randomized trial of testosterone replacement for diabetes. We also correlated DXA with single-slice CT (n=102) in a cohort of older males undergoing testosterone deprivation for prostate cancer. Lunar Prodigy DXA scanners using enCORE software was used to measure VAT. DXA VAT volume strongly correlated with MRI VAT volume (r=0.90, P<0.0001) and CT VAT area (r=0.83, P<0.0001). As DXA assesses VAT volume in a smaller compartment than MRI, Bland-Altman analysis demonstrated DXA systematically underestimated VAT by an approximately 30% proportional bias. DXA VAT volume measured by Lunar Prodigy DXA scanners correlate well with gold standard MRI and CT quantification methods, and provides a low radiation, efficient, cost-effective option. Future clinical studies examining the effects of interventions on body composition and regional fat distribution may find DXA an appropriate volumetric method to quantify VAT.


Asunto(s)
Absorciometría de Fotón , Grasa Intraabdominal/diagnóstico por imagen , Imagen por Resonancia Magnética , Obesidad/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Adiposidad , Anciano , Australia/epidemiología , Índice de Masa Corporal , Comorbilidad , Estudios Transversales , Humanos , Grasa Intraabdominal/fisiopatología , Masculino , Obesidad/complicaciones , Obesidad/fisiopatología , Reproducibilidad de los Resultados
7.
Phys Rev Lett ; 115(7): 076402, 2015 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-26317735

RESUMEN

The origin of the martensitic transition in the magnetic shape memory alloy Ni-Mn-Ga has been widely discussed. While several studies suggest it is electronically driven, the adaptive martensite model reproduced the peculiar nonharmonic lattice modulation. We used femtosecond spectroscopy to probe the temperature and doping dependence of collective modes, and scanning tunneling microscopy revealed the corresponding static modulations. We show that the martensitic phase can be described by a complex charge-density wave tuned by magnetic ordering and strong electron-lattice coupling.

8.
Osteoporos Int ; 25(8): 2027-33, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24803329

RESUMEN

UNLABELLED: In this longitudinal case-control study, acute fracture was associated with low serum testosterone, which was transient in 43% of men. While assessment of gonadal status is part of the assessment of bone fragility, measurement of testosterone in the early period after fracture may overestimate the prevalence of androgen deficiency. INTRODUCTION: Measurement of circulating testosterone is recommended in the evaluation of bone fragility in men. Since acute illness can transiently decrease circulating testosterone, we quantified the association of acute fracture and serum testosterone levels. METHODS: A case-control study was conducted involving 240 men with a radiologically confirmed minimal trauma fracture presenting to a tertiary referral hospital and 89 age-matched men without a history of minimal trauma fracture serving as controls. Follow-up testosterone levels 6 months after baseline were available for 98 cases and 27 controls. Results were expressed as the median and interquartile (IQR) range. RESULTS: Compared to controls, cases had lower total testosterone [TT, 7.2 (3.5, 10.8) vs 13.6 (10.9, 17.1) nmol/L, p < 0.001]. The 143 cases treated as inpatients had lower testosterone levels than the 97 cases treated as outpatients [TT 4.7 (2.3, 8.1) vs 10.3 (7.5, 12.7) nmol/L, p < 0.001]. Group differences in calculated free testosterone (cFT) were comparable to the group differences in TT. At follow-up, in 98 cases, median TT increased from 6.5 nmol/L (3.2, 8.5) to 9.6 nmol/L (6.9, 12.0) p < 0.0001, and SHBG remained unchanged. Of cases with low testosterone, 43% with TT <10 nmol/L and/or cFT <230 pmol/L at presentation were reclassified as androgen sufficient at follow-up. TT was unchanged in the controls. CONCLUSIONS: Low testosterone levels in men presenting with an acute fracture may, at least in part, be due to an acute, fracture-associated, stress response. To avoid over diagnosis, evaluation for testosterone deficiency should be deferred until recovery from the acute event.


Asunto(s)
Fracturas Osteoporóticas/sangre , Testosterona/sangre , Absorciometría de Fotón/métodos , Enfermedad Aguda , Anciano , Anciano de 80 o más Años , Densidad Ósea/fisiología , Estudios de Casos y Controles , Comorbilidad , Estudios de Seguimiento , Articulación de la Cadera/fisiopatología , Humanos , Vértebras Lumbares/fisiopatología , Masculino , Persona de Mediana Edad , Fracturas Osteoporóticas/fisiopatología , Testosterona/deficiencia
9.
Phys Med ; 104: 101-111, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36395638

RESUMEN

PURPOSE: To characterize an experimental setup for ultra-high dose rate (UHDR) proton irradiations, and to address the challenges of dosimetry in millimetre-small pencil proton beams. METHODS: At the PSI Gantry 1, high-energy transmission pencil beams can be delivered to biological samples and detectors up to a maximum local dose rate of âˆ¼9000 Gy/s. In the presented setup, a Faraday cup is used to measure the delivered number of protons up to ultra-high dose rates. The response of transmission ion-chambers, as well as of different field detectors, was characterized over a wide range of dose rates using the Faraday cup as reference. RESULTS: The reproducibility of the delivered proton charge was better than 1 % in the proposed experimental setup. EBT3 films, Al2O3:C optically stimulated luminescence detectors and a PTW microDiamond were used to validate the predicted dose. Transmission ionization chambers showed significant volume ion-recombination (>30 % in the tested conditions) which can be parametrized as a function of the maximum proton current density. Over the considered range, EBT3 films, inorganic scintillator-based screens and the PTW microDiamond were demonstrated to be dose rate independent within ±3 %, ±1.8 % and ±1 %, respectively. CONCLUSIONS: Faraday cups are versatile dosimetry instruments that can be used for dose estimation, field detector characterization and on-line dose verification for pre-clinical experiments in UHDR proton pencil beams. Among the tested detectors, the commercial PTW microDiamond was found to be a suitable option to measure real time the dosimetric properties of narrow pencil proton beams for dose rates up to 2.2 kGy/s.


Asunto(s)
Protones , Reproducibilidad de los Resultados
10.
Clin Endocrinol (Oxf) ; 74(3): 377-83, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21118287

RESUMEN

OBJECTIVE: Androgen deprivation therapy (ADT) for prostate cancer is associated with increases in fat mass and risk of type 2 diabetes; however, the relationship between sex steroid deficiency and abdominal fat distribution remains controversial. DESIGN: We conducted a 12-month prospective observational study at a tertiary referral centre. PATIENTS AND MEASUREMENTS: We investigated changes in abdominal fat distribution and insulin resistance in 26 men (70.6±6.8 years) with nonmetastatic prostate cancer during the first year of ADT. RESULTS: Twelve months of ADT increased visceral abdominal fat area by 22% (from 160.8±61.7 to 195.9±69.7 cm(2) ; P<0.01) and subcutaneous abdominal fat area by 13% (from 240.7±107.5 to 271.3±92.8 cm(2) ; P<0.01). Fat mass increased by 14% (+3.4 kg; P<0.001) and lean tissue mass decreased by 3.6% (-1·9 kg; P<0.001). Insulin resistance (HOMA-IR) increased by 12% (2.50±1.12 to 2.79±1.31, P<0.05). There was no change in fasting glucose or glycated haemoglobin levels. Total testosterone (TT) was inversely associated with visceral fat area independent of oestradiol (E2), but E2 was not associated with visceral fat area independent of TT. Visceral fat area, not TT or E2, was independently associated with insulin resistance. CONCLUSIONS: ADT for prostate cancer results in accumulation of both visceral and subcutaneous abdominal fat. Increased visceral fat area appears more closely linked to testosterone than oestradiol deficiency. Increased insulin resistance may arise secondary to visceral fat accumulation, rather than as a direct result of sex steroid deficiency.


Asunto(s)
Antagonistas de Andrógenos/efectos adversos , Grasa Intraabdominal/efectos de los fármacos , Neoplasias de la Próstata/tratamiento farmacológico , Grasa Subcutánea Abdominal/efectos de los fármacos , Análisis de Varianza , Antagonistas de Andrógenos/uso terapéutico , Estradiol/sangre , Humanos , Inmunoensayo/métodos , Resistencia a la Insulina , Grasa Intraabdominal/metabolismo , Modelos Lineales , Masculino , Estudios Prospectivos , Neoplasias de la Próstata/sangre , Neoplasias de la Próstata/metabolismo , Medición de Riesgo , Factores de Riesgo , Grasa Subcutánea Abdominal/metabolismo , Testosterona/sangre , Factores de Tiempo
11.
Thorac Cardiovasc Surg ; 59(1): 21-4, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21243567

RESUMEN

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus epidermidis (MRSE) are an increasing problem in deep sternal wound infections (DSWI) after cardiac surgery. METHODS: Between 2005 and 2009, recalcitrant methicillin-resistant Staphylococcus was found in 21 patients with complicated DSWI, and a transposition of the greater omentum (TGO) was finally performed. A positive microbial culture at the time of procedure was present in all patients. The hospital course was reviewed discretely for MRSA and MRSE. RESULTS: Median patient age was 72.3 years (range 60.8-79.7); 76 % of patients were male. Time from the first sternal revision until consecutive open wound therapy due to re-infection and total hospital stay was longer for MRSA compared to MRSE (38 vs. 14 days, P = 0.003, and 141 vs. 91 days, P = 0.007, respectively). The period from cardiac surgery to TGO was likewise prolonged for MRSA (78 vs. 55 days, P = 0.045), whereas in-hospital mortality and one-year mortality rate did not differ. CONCLUSION: TGO remains a good treatment option for DSWI type IV. Microbial findings determine the clinical course; nevertheless in-hospital mortality remains low for both MRSA and MRSE infection.


Asunto(s)
Resistencia a la Meticilina , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Epiplón/trasplante , Procedimientos de Cirugía Plástica/métodos , Infecciones Estafilocócicas/complicaciones , Esternotomía/efectos adversos , Infección de la Herida Quirúrgica/microbiología , Procedimientos Quirúrgicos Torácicos , Anciano , Procedimientos Quirúrgicos Cardíacos/efectos adversos , Femenino , Humanos , Tiempo de Internación , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Estudios Retrospectivos , Infecciones Estafilocócicas/mortalidad , Infecciones Estafilocócicas/cirugía , Staphylococcus epidermidis/aislamiento & purificación , Infección de la Herida Quirúrgica/mortalidad , Infección de la Herida Quirúrgica/cirugía , Análisis de Supervivencia , Procedimientos Quirúrgicos Torácicos/métodos , Resultado del Tratamiento
12.
Hum Reprod ; 25(9): 2316-27, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20634189

RESUMEN

BACKGROUND: Sister chromatid cohesion is essential for ordered chromosome segregation at mitosis and meiosis. This is carried out by cohesin complexes, comprising four proteins, which seem to form a ring-like complex. Data from animal models suggest that loss of sister chromatid cohesion may be involved in age-related non-disjunction in human oocytes. Here, we describe the distribution of cohesins throughout meiosis in human oocytes. METHODS: We used immunofluorescence in human oocytes at different meiotic stages to detect cohesin subunits REC8, STAG3, SMC1 beta and SMC3, [also synaptonemal complex (SC) protein 3 and shugoshin 1]. Samples from euploid fetuses and adult women were collected, and 51 metaphase I (MI) and 113 metaphase II (MII) oocytes analyzed. SMC1 beta transcript levels were quantified in 85 maturing germinal vesicle (GV) oocytes from 34 women aged 19-43 years by real-time PCR. RESULTS: At prophase I, cohesin subunits REC8, STAG3, SMC1 beta and SMC3 overlapped with the lateral element of the SC. Short cohesin fibers are observed in the oocyte nucleus during dictyate arrest. All four subunits are observed at centromeres and along chromosomal arms, except at chiasmata, at MI and are present at centromeric domains from anaphase I to MII. SMC1 beta transcripts were detected (with high inter-sample variability) in GV oocytes but no correlation between SMC1 beta mRNA levels and age was found. CONCLUSIONS: The dynamics of cohesins REC8, STAG3, SMC1 beta and SMC3 suggest their participation in sister chromatid cohesion throughout the whole meiotic process in human oocytes. Our data do not support the view that decreased levels of SMC1 beta gene expression in older women are involved in age-related non-disjunction.


Asunto(s)
Proteínas de Ciclo Celular/metabolismo , Proteoglicanos Tipo Condroitín Sulfato/metabolismo , Proteínas Cromosómicas no Histona/metabolismo , Aberraciones Cromosómicas , Meiosis , Proteínas Nucleares/metabolismo , Oocitos , Adulto , Envejecimiento , Proteínas de Ciclo Celular/genética , Núcleo Celular/metabolismo , Centrómero/metabolismo , Cromátides/genética , Proteínas Cromosómicas no Histona/genética , Proteínas de Unión al ADN , Femenino , Feto , Humanos , Oocitos/química , Oocitos/metabolismo , ARN Mensajero/metabolismo , Complejo Sinaptonémico/metabolismo , Adulto Joven , Cohesinas
13.
Intern Med J ; 40(4): 300-3, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20529040

RESUMEN

Carbimazole is a drug that is widely used for hyperthyroid disorders, such as Graves' disease. Agranulocytosis is a rare idiosyncratic adverse reaction to the drug which is potentially fatal. This report describes a patient with a history of successfully treated pyoderma gangrenosum, who developed agranulocytosis 3 weeks after commencement of carbimazole for Graves' disease. It may give credence to the theory that implicates antineutrophil cytoplasmic antibodies in the pathogenesis of agranulocytosis induced by antithyroid drugs.


Asunto(s)
Agranulocitosis/diagnóstico , Anticuerpos Anticitoplasma de Neutrófilos/fisiología , Adulto , Agranulocitosis/inducido químicamente , Agranulocitosis/inmunología , Anticuerpos Anticitoplasma de Neutrófilos/biosíntesis , Anticuerpos Anticitoplasma de Neutrófilos/sangre , Carbimazol/efectos adversos , Femenino , Humanos
14.
Vet Pathol ; 47(2): 202-13, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20124008

RESUMEN

In recent years, obesity has been identified as a risk factor for the development of breast cancer in postmenopausal women, and it has been associated with a poor outcome. Many factors appear to be important in the mechanism of this increased risk, including estrogen, estrogen receptors, and the adipokines leptin and adiponectin. Estrogen, a potent mitogen for mammary cells, has long been implicated in the development of mammary tumors. Because adipose-associated aromatase activity increases the conversion of androgen to estrogen, mammary adipose tissue is thought to be an important source of local estrogen production. Leptin, which increases in the circulation in proportion to body fat stores, has been demonstrated in vitro to promote breast cancer cell growth. Animal models have also identified leptin as an important factor for the development of mammary tumors. In contrast to leptin, serum adiponectin concentrations are inversely related to body fat stores, and the addition of adiponectin to human breast cancer cells reduces cell proliferation and enhances apoptosis. This review explores the relationship between these factors and the development of mammary cancer in humans and mouse models.


Asunto(s)
Neoplasias de la Mama/metabolismo , Transformación Celular Neoplásica/metabolismo , Obesidad/metabolismo , Adiponectina/metabolismo , Animales , Neoplasias de la Mama/patología , Transformación Celular Neoplásica/patología , Modelos Animales de Enfermedad , Estrógenos/metabolismo , Femenino , Humanos , Leptina/metabolismo , Ratones , Obesidad/patología , Receptores de Estrógenos/metabolismo
15.
Obes Res Clin Pract ; 14(6): 514-518, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33132075

RESUMEN

BACKGROUND: As the number of individuals with obesity increases, so too will the demand for a precise, cost-effective and safe method to better risk-stratify this heterogenous population. Visceral adipose tissue (VAT) area, a body composition measurement has been associated with the many facets of the metabolic syndrome. AIM: To determine the precision of dual energy X-ray absorptiometry (DXA) in providing body composition measurements, including VAT area, using the Hologic Horizon A scanner. METHOD: Thirty participants (mean age 64 years, 47% male), underwent two sequential body composition scans. The coefficient of variation (CV) and least significant change (LSC) were calculated for android/gynoid ratio, appendicular lean/height2, lean/height2, total body fat and lean mass, total body mass, and subcutaneous adipose tissue (SAT) and VAT area. Participants were stratified according to age (<70 or ≥70 years), body mass index (BMI) (≤30 kg/m2 or >30 kg/m2) and sex (male or female). The CV was calculated for each parameter and then analysed for differences between groups. RESULTS: The CV for all parameters was <3% with the exception of SAT (3.86%). The CV of VAT area was 2.63% with a LSC at 95% confidence of 7.28%. Apart from the CV differences between males and females for android/gynoid ratio (male: 3.56% vs. female: 1.74%, p = 0.01) and SAT area (5.04% vs. 2.46%, p = 0.01), there were no significant differences identified between the calculated CV for all other body composition parameters when participants were stratified by age, BMI and sex. CONCLUSION: DXA scanning, using the Hologic Horizon A system, is capable of providing precise body composition measurements.


Asunto(s)
Composición Corporal , Absorciometría de Fotón , Anciano , Índice de Masa Corporal , Femenino , Humanos , Grasa Intraabdominal , Masculino , Persona de Mediana Edad , Obesidad
16.
Andrology ; 8(6): 1519-1529, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-31502758

RESUMEN

BACKGROUND: Obesity and dysglycemia (comprising insulin resistance, the metabolic syndrome and type 2 diabetes), that is diabesity, are associated with reduced circulating testosterone and, in some men, clinical features consistent with androgen deficiency. OBJECTIVE: To review the metabolic impact of late-onset hypogonadism. METHODS: Comprehensive literature search with emphasis on recent publications. RESULTS: Obesity is one of the strongest modifiable risk factors for late-onset hypogonadism, and coexisting diabetes leads to further hypothalamic-pituitary-testicular axis suppression. The hypothalamic-pituitary-testicular axis suppression is functional and hence potentially reversible, and occurs predominantly at the level of the hypothalamus. While definitive mechanistic data are lacking, the evidence suggests that hypothalamic-pituitary-testicular axis suppression is mediated by dysregulation of pro-inflammatory cytokines leading to hypothalamic inflammation. Dysregulation of central leptin and insulin signaling may also contribute. In contrast, recent data challenge the paradigm that estradiol excess is a major contributor to hypothalamic-pituitary-testicular axis suppression. Instead, relative estradiol signaling deficiency may contribute to metabolic dysregulation in men with diabesity. While weight loss and optimization of comorbidities can reverse functional hypothalamic-pituitary-testicular axis suppression, testosterone treatment leads to metabolically favorable changes in body composition and to improvements in insulin resistance. DISCUSSION: The relationship between diabesity and late-onset hypogonadism is bidirectional. Preliminary evidence suggests that, in carefully selected men, lifestyle measures and testosterone treatment may have additive effects. CONCLUSIONS: While recent research has provided new insights into mechanistic and clinical aspects of diabesity-associated late-onset hypogonadism, more evidence from well-designed large trials is needed to guide the optimal clinical approach to such men.


Asunto(s)
Metabolismo Energético , Hipogonadismo/metabolismo , Síndrome Metabólico/metabolismo , Testosterona/deficiencia , Edad de Inicio , Animales , Biomarcadores/sangre , Diabetes Mellitus Tipo 2/epidemiología , Diabetes Mellitus Tipo 2/metabolismo , Terapia de Reemplazo de Hormonas , Humanos , Hipogonadismo/diagnóstico , Hipogonadismo/tratamiento farmacológico , Hipogonadismo/epidemiología , Resistencia a la Insulina , Masculino , Síndrome Metabólico/diagnóstico , Síndrome Metabólico/tratamiento farmacológico , Síndrome Metabólico/epidemiología , Obesidad/epidemiología , Obesidad/metabolismo , Pronóstico , Medición de Riesgo , Factores de Riesgo , Testosterona/sangre , Testosterona/uso terapéutico
17.
Int J Clin Pharmacol Ther ; 47(12): 761-9, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19954715

RESUMEN

OBJECTIVE: To assess bioequivalence between Equasym Retard and Medikinet retard containing 20 mg methylphenidate (MPH) hydrochloride in a fed state. MATERIALS: Equasym Retard 20 mg capsules (UCB, Monheim, Germany) and Medikinet retard 20 mg capsules (Medice, Iserlohn, Germany). METHODS: This was an open, single-center, randomized, 2-period, 2-sequence, balanced cross-over study with a wash-out period of 1 week between administrations in 14 healthy male and female volunteers, aged 18 - 45 years. Blood samples were collected over 24 hours and methylphenidate plasma concentration-time data were used to calculate pharmacokinetic metrics for both formulations. The main metrics were AUC0-t and Cmax. Bioequivalence was concluded if the 90% confidence interval (CI) for the ratio between test and reference was 80 - 125% (AUC0-t, Cmax). RESULTS: All dosed subjects finished both treatment periods and were included in pharmacokinetic and safety analyses. The adverse events observed, mainly nervous system disorders (headache), were all mild or moderate in intensity and resolved without any action taken. The adverse event profile was consistent with the currently applicable SmPCs (Summaries of Product Characteristics) for Equasym Retard and Medikinet retard. Geometric means +/- SD for AUC0-t and Cmax were 35.5 +/- 10.1 ng x h/ml and 4.05 +/- 0.96 ng/ml (Equasym Retard) and 39.2 +/- 13.8 ng x h/ml and 5.26 +/- 2.11 ng/ml (Medikinet retard). The 90% geometric confidence interval for AUC0-t (extent of absorption) was within limits accepted for bioequivalence. Bioequivalence could not be demonstrated for the rate of bioavailability (Cmax); both the lower confidence limit and the point estimate were below 80% of the reference. The study has shown that both formulations lead to a similar pattern of absorption and elimination following single dose administration in the fed state, although the test formulation shows a somewhat slimmer profile, where the first peak is less pronounced. No bioequivalence could be shown within the first 4 hours. The second peak of the test was also lower than the one of the reference (both lower confidence limit and point estimate below 80%). CONCLUSIONS: The two formulations are not bioequivalent, especially if the rate and values within the first four hours after administration are taken into account.


Asunto(s)
Estimulantes del Sistema Nervioso Central/administración & dosificación , Estimulantes del Sistema Nervioso Central/farmacocinética , Preparaciones de Acción Retardada/farmacocinética , Metilfenidato/administración & dosificación , Metilfenidato/farmacocinética , Adolescente , Adulto , Estimulantes del Sistema Nervioso Central/efectos adversos , Preparaciones de Acción Retardada/efectos adversos , Femenino , Humanos , Masculino , Metilfenidato/efectos adversos , Persona de Mediana Edad , Equivalencia Terapéutica
18.
J Nutr Health Aging ; 23(1): 105-110, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30569078

RESUMEN

BACKGROUND: Globally there are several operational definitions for sarcopenia, complicating clinical and research applications. OBJECTIVE: The objective of the Australian and New Zealand Society for Sarcopenia and Frailty Research (ANZSSFR) Task Force on Diagnostic Criteria for Sarcopenia was to reach consensus on the operational definition of sarcopenia for regional use by clinicians and researchers. METHOD: A four-Phase modified Delphi process was undertaken in which 24 individuals with expertise or a recognised interest in sarcopenia from different fields across Australia and New Zealand were invited to be Task Force members. An initial face-to-face meeting was held in Adelaide, South Australia, in November 2017, followed by two subsequent online Phases conducted by electronic surveys. A final Phase was used to approve the final statements. Responses were analysed using a pre-specified strategy. The level of agreement required for consensus was 80%. RESULTS: In Phase 2, 94.1% of Task Force respondents voted in favour of adopting an existing operational definition of sarcopenia. In Phase 3, 94.4% of respondents voted in favour of adopting the European Working Group on Sarcopenia in Older People (EWGSOP) definition as the operational definition for sarcopenia in Australia and New Zealand. CONCLUSION: With consensus achieved, the ANZSSFR will adopt, promote and validate the EWGSOP operational definition of sarcopenia for use by clinicians and researchers in Australia and New Zealand.


Asunto(s)
Sarcopenia/diagnóstico , Anciano , Anciano de 80 o más Años , Australia , Consenso , Femenino , Humanos , Masculino , Nueva Zelanda , Encuestas y Cuestionarios
19.
Oncogene ; 26(19): 2759-68, 2007 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-17086212

RESUMEN

Pancreatic ductal adenocarcinoma (PDAC) is characterized by rapid tumor progression, high metastatic potential and profound chemoresistance. We recently reported that induction of a chemoresistant phenotype in the PDAC cell line PT45-P1 by long-term chemotherapy involves an increased interleukin 1 beta (IL1beta)-dependent secretion of nitric oxide (NO) accounting for efficient caspase inhibition. In the present study, we elucidated the involvement of L1CAM, an adhesion molecule previously found in other malignancies, in this NO-dependent chemoresistance. Chemoresistant PT45-P1res cells, but not chemosensitive parental PT45-P1 cells, express high levels of L1CAM in an ILbeta-dependent fashion. PT45-P1res cells subjected to short interfering RNA (siRNA)-mediated L1CAM knock-down exhibited reduced inducible nitric oxide synthase expression and NO secretion, as well as a significant increase of anti-cancer drug-induced caspase activation, an effect reversed by the NO donor S-nitroso-N-acetyl-D,L-penicillamine. Conversely, overexpression of L1CAM in PT45-P1 cells conferred anti-apoptotic protection to anti-cancer drug treatment. Interestingly, L1CAM ectodomain shedding, in example, by ADAM10, as reported for other L1CAM-related activities, seemed to be dispensable for anti-apoptotic protection by L1CAM. Neither the shedded L1CAM ectodomain was detected in chemoresistant L1CAM-expressing PT45-P1 cells nor did the administration of various metalloproteinase inhibitors affect L1CAM-dependent chemoresistance. Immunohistochemical analysis revealed L1CAM expression in 80% of pancreatic cancer specimens, supporting a potential role of L1CAM in the malignancy of this tumor. These findings substantiate our understanding of the molecular mechanisms leading to chemoresistance in PDAC cells and indicate the importance of L1CAM in this scenario.


Asunto(s)
Adenocarcinoma/tratamiento farmacológico , Apoptosis/fisiología , Carcinoma Ductal Pancreático/tratamiento farmacológico , Resistencia a Antineoplásicos , Molécula L1 de Adhesión de Célula Nerviosa/metabolismo , Neoplasias Pancreáticas/tratamiento farmacológico , Adenocarcinoma/metabolismo , Adenocarcinoma/patología , Antineoplásicos Fitogénicos/farmacología , Apoptosis/efectos de los fármacos , Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/patología , Inhibidores de Caspasas , Caspasas/metabolismo , Adhesión Celular , Línea Celular Tumoral , Etopósido/farmacología , Humanos , Interleucina-1beta/metabolismo , Molécula L1 de Adhesión de Célula Nerviosa/efectos de los fármacos , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa de Tipo II/antagonistas & inhibidores , Óxido Nítrico Sintasa de Tipo II/metabolismo , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patología , Células Tumorales Cultivadas
20.
J Cardiovasc Surg (Torino) ; 49(4): 533-7, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18665118

RESUMEN

AIM: Valuable models of chronic heart failure to perform histological studies are scarce. The authors aimed at investigating histological changes of the heart, lung, liver and kidneys in a stable and reproducible animal model of chronic heart failure in sheep. METHODS: In 8 sheep (N.=8, 77+/-2 kg) chronic heart failure was induced by multiple sequential microembolization through bolus injection of polysterol microspheres (90 microm, N=25 000) into the left main coronary artery. Microembolization (ME) was repeated up to three times in two to three week intervals until animals started to develop stable signs of heart failure. Therefore, clinical and hemodynamic parameters were measured (Troponin T, heart and respiratory rate, cardiac output) after each embolization. Clinical examination was carried out by a veterinarian. All animals were followed for 3 months after first microembolization and then euthanized for histological examination. Histological data of the heart, lung, liver and the kidneys were analyzed in hematoxylin-eosin (HE) stains (10x, 25x, 100x) at baseline (control group) and at 3 months after first ME. Additionally preparations of heart tissue were stained with Picro-Sirius-Red (PSR) for planimetric quantification. A score from 0 to 4 according to Rassler et al. (2005) was used to assess the degree of lung injury. RESULTS: All animals developed histological signs of heart failure as indicated by island-like, patchy fibrosis of the heart. Planimetric quantification (PSR stain) of the heart revealed a significant increase of the total amount of fibrosis from 8+/-2% (base) to 21+/-4% (3 months) (P<0.05), which was distributed homogeneously throughout the left ventricle (20+/-3% left ventricular [LV] anterior wall, 21+/-4% LV posterior wall, 20+/-4% septum). Histologic analysis of the lung demonstrated a moderate degree of interstitial edema and pronounced peribronchial processes of inflammation with beginning proliferation of fibrotic tissue. Liver tissue showed histological changes in terms of pericentral adiposis as sign of hypoxia in course of lacking perfusion. Signs of liver congestion could be detected histological in form of central-venous accumulation of erythrocytes and dissolution of liver tissue in proximity of the central veins. Kidney preparations illustrated loss of endothelial function and vascular occlusions, caused by microspheres, with decline of renal parenchyma particularly of the tubules. CONCLUSION: Multiple sequential intracoronary microembolization can effectively induce myocardial dysfunction with histological signs of chronic ischemic cardiomyopathy and pathological changes of lung, liver and kidney, which can directly be coursed by chronic heart failure. Thus, the present model may be suitable in experimental work on heart failure and LV assist devices, e.g. for studying the impact of mechanical unloading, mechanisms of recovery and reverse remodeling.


Asunto(s)
Enfermedad de la Arteria Coronaria/complicaciones , Embolia/complicaciones , Insuficiencia Cardíaca/etiología , Miocardio/patología , Animales , Enfermedad Crónica , Enfermedad de la Arteria Coronaria/etiología , Enfermedad de la Arteria Coronaria/patología , Enfermedad de la Arteria Coronaria/fisiopatología , Modelos Animales de Enfermedad , Embolia/etiología , Embolia/patología , Embolia/fisiopatología , Insuficiencia Cardíaca/patología , Insuficiencia Cardíaca/fisiopatología , Inyecciones Intraarteriales , Riñón/patología , Hígado/patología , Pulmón/patología , Microesferas , Poliestirenos/administración & dosificación , Reproducibilidad de los Resultados , Ovinos
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