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1.
Rev Sci Instrum ; 92(10): 103101, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34717390

RESUMO

X-ray polarization-splitting crystals separate incident x rays into two components with perpendicular polarization by Bragg reflections at 45° from paired sets of internal planes. Here, the polarization-splitting properties of a germanium crystal are verified using incompletely polarized synchrotron radiation. Cleaner data would have come from a beam with a higher degree of polarization, which is achievable with small changes in the experimental geometry.

2.
Colorectal Dis ; 22(10): 1263-1270, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32306516

RESUMO

AIM: Intra-operative fluorescence angiography (IOFA) with indocyanine green provides information on tissue perfusion that may help prevent an anastomotic leak (AL). The aim of this study was to assess the impact of IOFA on outcomes after left-sided colonic or low anterior resection with anastomosis for colorectal cancer. METHODS: All patients with left-sided colonic or rectal cancer, operated between June 2017 and December 2018, were prospectively included. IOFA has been routinely implemented since May 2018. Reproducibility of IOFA, after a 1:1 matching for relevant clinical risk factors of AL, was studied in patients with IOFA (IOFA+) and without IOFA (IOFA-). Outcomes were compared in terms of postoperative events such as clinically relevant AL as the primary end-point. RESULTS: In the IOFA+ group, changing of the initially planned colon transection due to inadequate perfusion occurred in five out of 46 patients (10.9%). Agreement between intra-operative assessment and postoperative blind review of IOFA was deemed strong (Cohen's kappa index 0.893, 95% CI 0.788-0.998, P < 0.001). Among 111 patients, 42 matched patients were included in each group. There was significantly more clinically relevant AL in the IOFA- group compared to the IOFA+ group (16.7% vs 2.4%, P = 0.026) involving significantly more anastomotic dehiscence which required re-intervention (19% vs 2.4%, P = 0.014). Additionally, more descending colon ischaemia/necrosis was observed in the IOFA- group compared with the IOFA+ group (9.5% vs 0%, P = 0.040). CONCLUSION: In this prospective case-matched study, IOFA decreased the occurrence of clinically relevant AL due to necrosis of the descending colon or anastomosis. Upon blind review, perfusion assessment using IOFA was reproducible.


Assuntos
Fístula Anastomótica , Neoplasias Retais , Anastomose Cirúrgica/efeitos adversos , Fístula Anastomótica/etiologia , Fístula Anastomótica/prevenção & controle , Colo/cirurgia , Angiofluoresceinografia , Humanos , Verde de Indocianina , Estudos Prospectivos , Reprodutibilidade dos Testes
3.
J Endocrinol Invest ; 43(6): 841-852, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31902058

RESUMO

OBJECTIVE: To present the sonographic follow-up of intrathyroidal ectopic thymus (IET) in children and adolescent patients. PATIENTS: Out of the 507 children referred to FNAB between 2006 and 2018, 30 (5.9%) pediatric patients (10 females), mean age 5.7 years (1.2-13.8, median 4.9 years) were diagnosed with IET. METHODS: A retrospective analysis of medical files of patients diagnosed with IET between 2006 and 2018. Assessed data included ultrasound characterisation, elastographic strain ratio (SR) results and hormonal evaluation. RESULTS: Analysis of thyroid US scans revealed that the mean age at the first thyroid ultrasound was 5.7 (1.2-13.8, median 4.9) years, and at the last US 10.7 (3.7-18, median 10.5) years. The mean time of the IET observation was 59.6 (2-148, median 53.5) months. On US, IET was hypoechoic with multiple linear and punctate echoes, hypovascular, fusiform on longitudinal plane and round or polygonal on an axial plane, more common in the right thyroid lobe (66.7%) and located in the posterior part of the lobes (54.5%), bilateral in two patients and multifocal in one patient. SR of IET was similar to the surrounding normal thyroid tissue. Complete regression of IET was observed in 12/30 patients after a mean time of 81.7 months (median 76.5), at the mean age of 13.7 (9.2-18, median 13.9) years. FNAB was performed in 10/30 and a hemithyroidectomy in 1/30 IET patients. In the FNAB (+) group, patients were younger (5.08 vs 6.08 years) and lesions were larger (0.12 ml vs 0.05 ml) than in the FNAB (-) group. All patients with IET were euthyroid with negative TPOAb and TgAb levels. CONCLUSION: The reproducibility of unique ultrasound features of IETs allows for safe long-term follow-up of these benign lesions in the majority of pediatric patients: not only monitoring the regression of IET but also screening towards the rare occurrence of a tumor arising from the IET.


Assuntos
Coristoma/diagnóstico por imagem , Timo , Glândula Tireoide/diagnóstico por imagem , Ultrassonografia de Intervenção/tendências , Adolescente , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Lactente , Masculino
4.
J Physiol Pharmacol ; 70(4)2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31642814

RESUMO

Early weaning of ewe lambs strongly stimulates the hypothalamic-pituitary-adrenal axis and is associated with suppressed growth rate despite the increased food intake. At the same time, plasma leptin concentration increases only slightly or undetectably. To better understand this atypical interdependence among somatic stress, leptin, and lamb growth rate, we analyzed impact of leptin and/or adrenocorticotropic hormone (ACTH) on growth hormone (GH) secretion as well as the effect of ACTH on mRNA expression of two splice variants of leptin receptor (LEPRa, LEPRb) in pituitary cells isolated from early weaned ewe lambs. The GH secretion under the influence of leptin and/or ACTH depended on the timing of exposure and hormone concentration. After 6 - 30 h, GH secretion increased under 10-11 - 10-8 M leptin (P ≤ 0.05). However, after 24 - 30 h, GH secretion significantly increased only in cells exposed to both leptin and ACTH compared to culture with leptin only. Simultaneously, there was a significant (P ≤ 0.05) decrease in leptin receptor mRNA expression under the influence of ACTH at 10-8 - 10-6 M after 12 - 30 and 24 - 30 h for LEPRa and LEPRb, respectively. ACTH-related downregulation of LEPR mRNA was associated with a significant (P ≤ 0.05) reduction in leptin-stimulated GH secretion, also after 24 - 30 hours. Thus, the timing of ACTH exposure, followed by decreased leptin receptor mRNA, converged with the timing of decreased GH secretion under the influence of leptin with ACTH. The ACTH-induced downregulation of LEPR mRNA therefore may underlie the decrease in GH. These results show a direct role for leptin, ACTH, and leptin receptor expression in modulation of pituitary GH secretion in early weaned ewe lambs. During the early weaning-induced stress response, the ACTH-mediated decrease in sensitivity of pituitary cells to leptin may abolish a stimulatory effect of leptin on GH secretion and explain in part, the reduction in lamb growth rate.


Assuntos
Hormônio Adrenocorticotrópico/farmacologia , Hormônio do Crescimento/metabolismo , Leptina/farmacologia , Receptores para Leptina/genética , Animais , Feminino , Hipófise/citologia , Hipófise/metabolismo , RNA Mensageiro/metabolismo , Ovinos , Desmame
5.
J Endocrinol Invest ; 42(3): 261-270, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29872995

RESUMO

PURPOSE: To present the outcomes of ultrasound (US) follow-ups in children with autoimmune thyroid disease who did not have a thyroid nodule on admission but developed papillary thyroid carcinoma (PTC) and to characterize the parenchymal changes in the thyroid gland prior to the development of PTC. METHODS: A retrospective thyroid US scan review of 327 patients diagnosed with AIT was performed. Forty patients (40/327, 12.2%) presented nodular AIT variant with a normoechogenic background. Eleven patients (11/327, 3.4%, 11/40, 27.5%) presenting this variant were diagnosed with PTC (nine females-mean age 15.3 years; two males aged 11 and 13 years). In five of 11 patients, the suspicious nodule that was later confirmed to be PTC was detected on the initial US at presentation. For the remaining six females (6/11) who developed PTC during the follow-up, we retrospectively analysed their US thyroid scans and these patients were selected for analysis in this study. RESULTS: On admission, the US evaluation revealed an enlarged normoechogenic thyroid gland in three patients and a hypoechogenic thyroid gland with fibrosis as indicated by irregular, chaotic hyperechogenic layers in three patients. No thyroid nodules were identified. Ultrasound monitoring revealed increasing echogenicity of the thyroid parenchyma during the follow-up. PTC developed in a mean time of 4.6 years (1 9/12-7 4/12 years) since referral to the outpatient thyroid clinic and 2.9 years (6/12-6 9/12) since the last nodule-free US thyroid scan. CONCLUSIONS: Sonographic follow-up assessments warrant further exploration as a strategy to determine PTC susceptibility in the paediatric population.


Assuntos
Carcinoma Papilar/patologia , Tecido Parenquimatoso/patologia , Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/patologia , Tireoidite Autoimune/complicações , Adolescente , Adulto , Carcinoma Papilar/diagnóstico por imagem , Carcinoma Papilar/etiologia , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Masculino , Tecido Parenquimatoso/diagnóstico por imagem , Prognóstico , Estudos Retrospectivos , Glândula Tireoide/diagnóstico por imagem , Neoplasias da Glândula Tireoide/diagnóstico por imagem , Neoplasias da Glândula Tireoide/etiologia , Tireoidite Autoimune/diagnóstico , Tireoidite Autoimune/diagnóstico por imagem , Ultrassonografia , Adulto Jovem
6.
J Endocrinol Invest ; 41(3): 371-380, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28866751

RESUMO

BACKGROUND: The prevalence of autoimmune thyroiditis (AIT) and papillary thyroid carcinoma (PTC) is rising in children and adolescents, and the coincidence of AIT and PTC is as high as 6.3-43%. OBJECTIVE: To investigate the ultrasound manifestation of AIT in relation to PTC development in paediatric patients. PATIENTS: 179 paediatric patients (133 females), mean (SD) age: 13.9 (3.03) years diagnosed with AIT and referred for ultrasound evaluation. Eight patients were diagnosed with PTC (6 females). METHODS: Retrospective analysis of thyroid ultrasound scans of patients diagnosed with AIT. Thyroid and autoimmune status was assessed based on TSH, fT4, fT3 and increased aTPO and/or aTG and/or TRAB levels. In patients with PTC, total thyroidectomy was performed. RESULTS: Analysis of thyroid US scans revealed that the following five ultrasound variants of AIT were observed in 179 patients: the most common in 35.2%-diffuse thyroiditis with hypoechogenic background and normoechogenic parenchyma, in 30.2%-diffuse thyroiditis with irregular background, in 18.9% nodular variant with normoechogenic background, in 11.7%-micronodulations and in 3.9%-diffuse hypoechogenic background. Eight cases of PTC were diagnosed in nodular variant of AIT with normoechogenic irregular background. CONCLUSION: Patients with AIT and nodular variant with normoechogenic irregular background of the thyroid gland on US scans are in the risk group of developing PTC and should be followed up with regular neck US assessment.


Assuntos
Carcinoma Papilar/patologia , Neoplasias da Glândula Tireoide/patologia , Tireoidite Autoimune/complicações , Ultrassonografia/métodos , Adolescente , Carcinoma Papilar/diagnóstico por imagem , Carcinoma Papilar/etiologia , Criança , Feminino , Seguimentos , Humanos , Masculino , Prognóstico , Estudos Retrospectivos , Neoplasias da Glândula Tireoide/diagnóstico por imagem , Neoplasias da Glândula Tireoide/etiologia , Tireoidite Autoimune/diagnóstico , Tireoidite Autoimune/diagnóstico por imagem
7.
Sci Rep ; 7(1): 16438, 2017 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-29180637

RESUMO

The self-face has a prioritized status in the processing of incoming visual inputs. As the self-face changes over the lifespan, this stimulus seems to be well-suited for investigation of the self across time. Here, steady-state visual evoked potentials (SSVEP, oscillatory responses to periodic stimulation with a frequency that mirrors the frequency of stimulation) were used to investigate this topic. Different types of faces (present self, past self, close-other's, unknown, scrambled) flickered four times per second in two types of stimulation ('identical', with the same image of a given type of face; 'different', with different images of the same type of face). Each of the 10 stimulation sessions lasted 90 seconds and was repeated three times. EEG data were recorded and analyzed in 20 participants. In general, faces evoked higher SSVEP than scrambled faces. The impact of identical and different stimulation was similar for faces and scrambled faces: SSVEP to different stimuli (faces, scrambled faces) was enhanced in comparison to identical ones. Present self-faces evoked higher SSVEP responses than past self-faces in the different stimulation condition only. Thus, our results showed that the physical aspects of the present and past selves are differentiated on the neural level in the absence of an overt behavior.


Assuntos
Potenciais Evocados Visuais/fisiologia , Reconhecimento Facial , Autoimagem , Adulto , Eletroencefalografia , Feminino , Humanos , Masculino , Estimulação Luminosa
8.
Appl Radiat Isot ; 126: 165-167, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28161104

RESUMO

First measurements of natural surface and bulk 210Po specific activities for metals are reported. If covered with protective foils, the surfaces did not show indications of 210Po and the obtained upper limits are in the range of single mBqm-2. Weak bulk activities, in the range of 50 - 280mBqkg-1, were registered for Stainless Steel and Copper, while significant amounts of 210Po, ∼1.5Bqkg-1, were detected in Titanium. One special Teflon sample was investigated with respect to its bulk 210Po.

9.
Bioprocess Biosyst Eng ; 39(8): 1319-23, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27066801

RESUMO

A new method for determination of the optimum temperature and activation energies based on an idea of the average rate of enzymatic reaction has been developed. A mathematical model describing the effect of temperature on a dimensionless activity for enzyme deactivation following the first-order kinetics has been derived. The necessary condition for existence of the function extreme of the optimal temperature has been applied in the model. The developed method has been verified using the experimental data for inulinase from Kluyveromyces marxianus.


Assuntos
Enzimas/metabolismo , Temperatura , Cinética , Modelos Teóricos
10.
Angiology ; 67(5): 471-7, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26198473

RESUMO

Patients with familial hypercholesterolemia (FH) are at increased risk of premature cardiovascular disease. We compared factors associated with the presence of carotid plaques and carotid intima-media thickness (cIMT), markers of subclinical atherosclerosis, in 241 patients with FH (98, 40.7% men; mean age 41 ± 18.4 years). Patients with FH having carotid plaques (36.5%) had mean age, apolipoprotein (apo) B, glucose, apoA1, systolic blood pressure (SBP) and diastolic BP, waist/hip ratio (WHR), and body mass index higher than patients without plaques. Logistic regression revealed that apoB (odds ratio [OR] per 1 unit change 1.03,P= .005), high-density lipoprotein cholesterol (HDL-C; OR per 1 standard deviation [SD] change 0.59,P= .015), and non-HDL-C (OR per 1SD change 1.53,P= .04) were significantly associated with the presence of plaques. The cIMT correlated with obesity parameters, BP, apoB, glucose, high-sensitivity C-reactive protein, creatinine, γ-glutamyl transpeptidase, and alanine transaminase (P< .001). Regression analysis revealed that cIMT was significantly associated with apoB, SBP, and WHR. These results confirm the role of apoB-containing lipoproteins and low HDL-C with the presence of carotid plaques and apoB, BP, and WHR with cIMT.


Assuntos
Apolipoproteínas B/sangue , Aterosclerose/complicações , Espessura Intima-Media Carotídea , HDL-Colesterol/sangue , Hiperlipoproteinemia Tipo II/complicações , Lipoproteínas HDL/metabolismo , Adulto , Idoso , Aterosclerose/sangue , Pressão Sanguínea/fisiologia , Feminino , Humanos , Hiperlipoproteinemia Tipo II/diagnóstico , Hiperlipoproteinemia Tipo II/metabolismo , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Adulto Jovem
11.
Pol J Vet Sci ; 18(2): 407-13, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26172192

RESUMO

Deleterious response to road transport is an important problem in equine practice. It determines different physiological, immunological and metabolic changes which lead to increased susceptibility to several disorders such as pneumonia, diarrhea, colics, laminitis, injuries and rhabdomyolisis. The aim of our study was to look for possible relationships between transportation of female young and older horses over a long and short distance and an inflammatory state reflected by an increase of acute phase protein concentration, oxidative stress and muscle injury. The study was conducted on 24 cold-blooded female horses divided into four groups. Six fillies aged 6-18 months and six mares aged 10-12 years were transported over the distance of about 550 km, six fillies aged 6-18 months and six mares aged 10-12 years were transported over the distance of about 50 km. Plasma and serum were obtained from blood samples taken before transportation (T0), immediately after transportation (T1) and at an abattoir during slaughter (T2). In these samples fibrinogen, MDA, AST and CK were assessed. Fibrinogen increased in all studied groups especially in fillies after long distance transportation, where it reached 205±7.07 mg/dl before transportation, 625±35.35 mg/dl after transportation, and 790±14.14 mg/dl during slaughter. MDA concentrations rose after transportation and reached the maximal level during slaughter. CK activity was more elevated after short transportation in younger horses, whereas initial activity of AST was higher in older horses. We estimated that intensified responses from acute phase, oxidative stress and muscle injury parameters indicated an inflammatory state.


Assuntos
Doenças dos Cavalos/etiologia , Cavalos/fisiologia , Inflamação/veterinária , Envelhecimento/fisiologia , Animais , Biomarcadores/sangue , Creatina Quinase/sangue , Creatina Quinase/metabolismo , Feminino , Fibrinogênio/metabolismo , Inflamação/etiologia , Malondialdeído/sangue , Malondialdeído/metabolismo
12.
Exp Clin Endocrinol Diabetes ; 123(4): 252-9, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25868061

RESUMO

OBJECTIVES: The assessment of the health consequences associated with obesity in young children is challenging. The aims of this study were: (1) to compare insulin resistance indices derived from OGTT in obese patients and healthy control (2) to analyze central obesity and Type 2 Diabetes genes expression in obese children, with special attention to the youngest group (< 10 years old). PATIENTS AND METHODS: The study included 49 children with obesity (median age 13.5 years old), and 25 healthy peers. Biochemical blood tests and expression of 11 central obesity and 33 Type 2 Diabetes genes was assessed. RESULTS: A significant difference in insulin resistance between obese and non-obese adolescents was observed in all studied indices (mean values of the insulin levels: 24.9 vs. 9.71 mIU/L in T0, 128 vs. 54.7 mIU/L in T60 and 98.7 vs. 41.1 mIU/L in T120 respectively; AUC: 217 vs. 77.2 ng/ml*h, mean values of B% (state beta cell function), S% (insulin sensitivity), and IR were 255 (±97) vs. 135 (±37.8), 46.6 (±37.3) vs. 84.2 (±29.6) and 3 (±1.55) vs. 1.36 (±0,56); HIS, WBIS and ISIBel median 3.89, 44.7, 0.73 vs. 8.57, 110, 2.25. All comparisons differed significantly p<0.001). Moreover, insulin sensitivity was significantly better in the older obese group (>10 years old): median AUC 239 vs. 104 ng/ml*h, and HIS, WBIS and ISIBel 3.57, 38, 0.67 vs. 6.23, 75.6, 1.87 respectively in the obese older compared to the obese younger subgroup, p<0.05. The expression of 64% of the central obesity genes and 70% of Type 2 Diabetes genes was higher in the obese compared to control groups. The differences were more pronounced in the younger obese group. CONCLUSION: Insulin resistance may develop in early stage of childhood obesity and in very young children may be associated with higher expression of the central obesity and Type 2 Diabetes genes.


Assuntos
Diabetes Mellitus Tipo 2/genética , Expressão Gênica , Resistência à Insulina/genética , Obesidade Abdominal/genética , Adolescente , Criança , Pré-Escolar , Feminino , Teste de Tolerância a Glucose , Humanos , Masculino
13.
J Endocrinol Invest ; 38(3): 345-9, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25304095

RESUMO

PURPOSE: An increased risk of insulin resistance, hypertension and liver dysfunction is related to obesity (Ob), but may be also present in normal-weight Turner syndrome (TS) patients. The aim of the study was to compare metabolic risk in adolescents with TS and Ob. METHODS: The study included 21 non-obese with TS (all receiving human recombinant growth hormone, 17/21 estrogen/estrogen-progesterone), and 21 age-matched Ob girls (mean age 13.9 years). Glucose and serum insulin levels were assessed fasting and in 120' of standard oral glucose tolerance test. Levels of triglycerides (TG), total cholesterol (TC), low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol, alanine aminotransferase (ALT), FGF19, FGF21 and FGF23 levels were measured fasting. RESULTS: Mean BMI SDS was significantly lower in TS patients (0.1 vs 4.8 SD, p < 0.001). The mean systolic and diastolic blood pressure was significantly lower in TS patients (102.6 vs 124.2 mmHg, p < 0.001 and 67.1 vs 76.5 mmHg, p = 0.02). There were no differences concerning mean fasting, and post-load glucose (4.5 vs 4.3, 5.1 vs 5.8 mmol/L), and insulin (14.97 vs 17.19 and 69.3 vs 98.78 µIU/mL) levels, HOMA-IR (3.02 vs 3.4), TC (4.05 vs 4.4 mmol/L), TG (1.25 vs 1.37 mmol/L), ALT (26.9 vs 28.3 IU/L), FGF19 (232.8 vs 182.7 pg/mL), and FGF23 (12.3 vs 17.5 pg/mL) levels. Mean LDL (2.05 vs 2.7 mmol/L, p = 0.003) and FGF21 (293.9 vs 514.7 pg/mL, p = 0.007) levels were significantly lower, and HDL (1.7 vs 1.2 mmol/L, p < 0.001) level higher in TS group. CONCLUSIONS: Insulin resistance in adolescents with TS on growth hormone treatment is comparable to Ob patients, but overall metabolic risk factors seem to be lower.


Assuntos
Glicemia/metabolismo , Resistência à Insulina/fisiologia , Insulina/sangue , Obesidade/metabolismo , Síndrome de Turner/metabolismo , Adolescente , Criança , Feminino , Fator de Crescimento de Fibroblastos 23 , Fatores de Crescimento de Fibroblastos/sangue , Teste de Tolerância a Glucose , Hormônio do Crescimento Humano/uso terapêutico , Humanos , Lipídeos/sangue , Obesidade/sangue , Fatores de Risco , Síndrome de Turner/sangue , Síndrome de Turner/tratamento farmacológico
14.
Phys Chem Chem Phys ; 16(30): 16067-74, 2014 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-24964926

RESUMO

Systematic studies on three dimensionally ordered liquid crystalline phases of different cubic and tetragonal symmetries are presented. The structures of the phases are determined by reconstruction of the electron density distribution from the X-ray diffraction patterns. The known models for electron densities in cubic structures were used whereas a new theoretical model for the structure of the tetragonal phase, which shows good agreement with the experimentally obtained electron densities, was proposed. For the first time a continuous phase transition between three dimensional phases with tetragonal and monoclinic symmetries was observed for an optically pure compound.

15.
Scanning ; 36(1): 105-14, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-23804490

RESUMO

The surface functionality of interacting components is determined by evaluating geometric surface structure. Hence, the ceramic femoral heads originated from precision machining were subject to measurement and analysis with regard to roughness, surface damages and deviation from roundness. A variety of measurement techniques were applied in order to thoroughly examine the product quality. The obtained results proved in accordance with the specification: Ra was not greater than 0.05 µm, whereas Δ was less than 10 µm (5 µm) when ceramic balls were used in conjunction with a polyethylene (ceramic) socket. Additionally, the surface damages which can affect the life of a friction pair were analyzed.


Assuntos
Cerâmica/química , Prótese de Quadril , Substitutos Ósseos/química , Cabeça do Fêmur/química , Dureza , Humanos , Teste de Materiais , Microscopia Eletrônica de Varredura , Propriedades de Superfície
16.
Pol J Vet Sci ; 17(4): 703-11, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25638985

RESUMO

Ketogenic diet (KD) is considered in the context of its anti-epileptic effects, but its influence on liver dysfunction has not been elucidated yet. The study was aimed to investigate the activity of hepatocytes (Hep) and hepatic stellate cells (HSC) isolated from rats fed with KD, in respect of NO and superoxide generation by these cells as well as their proliferative activity in vitro. We also sought to characterize the plasma FFA profiles in control and ketogenic rats. Hep and HSC were isolated by the collagenase perfusion method and separated by the Percoll gradient centrifugation. After the 4th, 8th and 12th day of incubation, the media were collected for further analysis. NO generation increased within the time of incubation both in Hep and HSC isolated from KD-rats. In HSC group NO production raised significantly from 2.65 ± 0.07 µM/10(6) cells on 4th day of incubation to 5.49 ± 1.2 µM/10(6) cells on 12th day of incubation. In respect to O2⁻· generation experimental Hep and HSC provide considerably higher quantities of this free radical until 12th day of incubation (2.5 ± 0.07 and 3.2 ± 0.3 nM/10(6) cells, respectively). Although KD exerts anti-proliferative effect on hepatocytes, in respect to HSC it intensifies their proliferative activity. Furthermore, as we estimated on the basis of NO and O2⁻. generation both Hep and HSC exposed to KD are the source of free radicals.


Assuntos
Dieta Cetogênica/efeitos adversos , Células Estreladas do Fígado/efeitos dos fármacos , Hepatócitos/efeitos dos fármacos , Animais , Proliferação de Células , Feminino , Ratos , Ratos Wistar
17.
Appl Radiat Isot ; 81: 146-50, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23628514

RESUMO

Results of alpha spectrometric measurements performed deep underground and above ground with and without active veto show that the underground measurement of thick samples is the most sensitive method due to significant reduction of the muon-induced background. In addition, the polonium diffusion requires for some samples an appropriate selection of an energy region in the registered spectrum. On the basis of computer simulations the best counting conditions are selected for a thick lead sample in order to optimize the detection limit.


Assuntos
Algoritmos , Partículas alfa , Artefatos , Polônio/análise , Radiometria/métodos , Análise Espectral/métodos , Doses de Radiação , Reprodutibilidade dos Testes , Espalhamento de Radiação , Sensibilidade e Especificidade
18.
J Physiol Pharmacol ; 64(1): 19-26, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23568967

RESUMO

The discrepancy about the role of estrogens in hepatic fibrogenesis and lack of studies addressed of ketogenic diet (KD) on hepatic stellate cells (HSC), prompted us to investigate the activity of HSC in control, KD- and thioacetamide (TAA)-administrated rats with different plasma concentration of estradiol (E2). HSC were isolated by the collagenase perfusion methods and separated by the Percoll gradient centrifugation. After the 4(th) and 8(th) day of incubation, lysates of HSC and the media were collected for further analysis. The HSC derived from KD-rats released remarkably more transforming growth factor (TGF)-ß1 than cells obtained from animals fed with a standard diet. The ovariectomy of KD-rats markedly intensified the secretion of this fibrogenic cytokine on the 8(th) day of incubation (201.33 ±1 7.15 pg/ml). In HSC of rats exposed to E2, the TGF-ß1 concentration did not exceed 157 ± 34.39 pg/ml. In respect to the collagen type I, the HSC obtained from ovariectomised KD-rats released an augmented amount of this ECM protein after the 8(th) day of culture (1.83 ± 0.14 U/ml). In the same time, higher quantities of ASMA appeared in the KD rats (1.41 ± 0.3 pg/mg protein). Exposition of rats to E2 did not markedly decrease the amount of ASMA. In summary, KD was able to induce morphological and functional changes in HSC, especially derived from rats deprived of ovarian estrogens. However, the preservation of E2 in ovariectomised rats didn't substantially alter the activation of HSC.


Assuntos
Dieta Cetogênica/métodos , Células Estreladas do Fígado/metabolismo , Células Estreladas do Fígado/fisiologia , Animais , Autoanticorpos/metabolismo , Colágeno Tipo I/metabolismo , Citocinas/metabolismo , Estradiol/metabolismo , Feminino , Células Estreladas do Fígado/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Ovariectomia/métodos , Ratos , Ratos Wistar , Tioacetamida/administração & dosagem , Fator de Crescimento Transformador beta1/metabolismo
19.
J Radioanal Nucl Chem ; 296(2): 639-645, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-26224934

RESUMO

Deposition of 226Ra from water on nylon was investigated. Measurements performed for different pH and different radium concentrations in the water gave similar absolute activities deposited on the foil surface. Obtained results were used to estimate the amount of 226Ra plated-out on the nylon scintillator vessel in the solar neutrino experiment BOREXINO during filling of the detector. Another problem studied in the frame of BOREXINO was the removal of 210Pb from its organic liquid scintillator by applying distillation and water extraction. After several tests had been performed for both methods it was found that after the water extraction the initial lead content in the scintillator sample was reduced only accordingly to the ratio of the volumes of the applied liquids (simple dilution). In contrast to this, distillation was very effective providing in the best case a 210Pb reduction factor higher than 100. Removal efficiencies of the long-lived 222Rn daughters during etching from surfaces of standard and high purity germanium were investigated in the frame of the GERDA experiment, which aims to search for neutrino-less double beta decay of 76Ge. The standard etching procedure of Canberra used during production of high purity n-type germanium diodes was applied to germanium discs, which had been exposed earlier to a strong 222Rn source for its progenies deposition. In contrast to copper and stainless steel, 210Pb, 210Bi and 210Po was removed from germanium very efficiently. An evidence of a reverse process was also observed-the isotopes were transferred from the etchant to the clean germanium surface.

20.
J Physiol Pharmacol ; 63(6): 669-76, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23388483

RESUMO

Since numerous studies indicate that 2-methoxyestradiol (2-ME) as a metabolite of 17beta estradiol (17ß-E(2)) may exert antitumor activity by unclear mechanism, we undertake the study to elucidate the effect of 2-ME on oval cells (OC) activated by a carcinogenic choline deficient ethionine supplemented diet (CDE diet). Isolated OC were treated with different concentrations of 2-ME for 24, 48 and 72 hours. In these periods of time phenotypic studies, apoptosis detection and proliferative activity of cells were performed. A marked inhibition of OC proliferation was observed at the presence of 1.0 µM of 2-ME, with the lowest value obtained after 48 h. However, at the end of the cells' incubation, maximally reduced proliferative response of OC was attributed to 2.0 µM of 2-ME. Simultaneously with the time of incubation the amount of Thy-1-positive cells decreased slightly from 50.5±1.4% to 31.5±3.6%. Contrary to 1.0 and 2.0 µM of 2-ME, its lowest value (0.5 µM) reduced Thy-1 positive cells after 48 hours. The same 2-ME concentration resulted in the elevation of the cell number expressing CK-19. In turn, the marked increase of albumine-positive cells was observed under 1.0 µM of 2-ME and reaching 21.5±6.2 % and 23.9±5.7% after 48 and 72 hours, respectively. Although the presence of 1.0 µM of 2-ME dramatically intensified apoptosis within 24 h of cell culture, the percentage of apoptotic cells remained unchanged under 2.0 µM of 2-ME. When subjected to the carcinogenic effect of CDE, 2-ME exerts anti-proliferative, proapoptotic, and differentiation effects in OC.


Assuntos
Apoptose/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Deficiência de Colina/patologia , Dieta , Estradiol/análogos & derivados , Etionina/administração & dosagem , Fígado/efeitos dos fármacos , 2-Metoxiestradiol , Animais , Biomarcadores/metabolismo , Células Cultivadas , Deficiência de Colina/metabolismo , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Estradiol/farmacologia , Feminino , Fígado/metabolismo , Fígado/patologia , Ratos , Ratos Wistar , Fatores de Tempo
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