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Wyszukujesz frazę "growth factor" wg kryterium: Temat


Tytuł:
Mechanism of fatigue crack growth of bridge steel structures
Mechanizm rozwoju pęknięć zmęczeniowych stalowych konstrukcji mostów
Autorzy:
Zhu, H.
Powiązania:
https://bibliotekanauki.pl/articles/231146.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
współczynnik intensywności naprężenia
metoda elementów skończonych
metoda rozszerzona
symulacja
rozwój pęknięć
pęknięcie zmęczeniowe
most
stress intensity factor
extended method
finite element method
simulation
fatigue crack
crack growth
bridge
Opis:
This study was carried out on the background of Sutong Bridge project based on fracture mechanics, aiming at analyzing the growth mechanism of fatigue cracks of a bridge under the load of vehicles. Stress intensity factor (SIF) can be calculated by various methods. Three steel plates with different kinds of cracks were taken as the samples in this study. With the combination of finite element analysis software ABAQUS and the J integral method, SIF values of the samples were calculated. After that, the extended finite element method in the simulation of fatigue crack growth was introduced, and the simulation of crack growth paths under different external loads was analyzed. At last, we took a partial model from the Sutong Bridge and supposed its two dangerous parts already had fine cracks; then simulative vehicle load was added onto the U-rib to predict crack growth paths using the extended finite element method.
Ostatnimi laty, wraz z gwałtownym rozwojem chińskiego przemysłu transportowego, budowa mostów w Chinach weszła w nowy etap rozwoju robiąc duży krok naprzód i coraz więcej mostów rzecznych i morskich wyrasta z ziemi, a mosty te stały się niezastąpioną osią chińskiej sieci transportowej. Konstrukcja stalowa jest głównym komponentem budowy mostu; jednakże, może ulec zniszczeniu poprzez ciągłe obciążanie doprowadzając w ten sposób do pęknięć zmęczeniowych. Wraz ze wzrostem budowy mostów zwiększa się liczba fatalnych wypadków spowodowanych pęknięciami zmęczeniowymi, prowadząc do wysokich praktycznych wymagań dotyczących bezpieczeństwa i niezawodności konstrukcji. Współczynnik intensywności naprężenia (WIN) i kryteria rozwoju pęknięć to dwa kluczowe problemy w mechanice pęknięć. Metody obliczania WIN obejmują metodę analityczną i numeryczną, przy czym numeryczna metoda obejmuje metodę elementów skończonych, metodę objętości skończonej oraz metodę elementów brzegowych itd. Metoda elementów skończonych jest najczęściej stosowana do obliczania WIN, a metody obliczania WIN obejmują metodę zależną od przemieszczeń, wirtualną metodę zamykania szczelin, metodę całki J itd. Teoretyczny proces dedukcji WIN jest skomplikowany. Dla różnych modeli pęknięć zmiany warunków brzegowych spowodują brak przydatności pierwotnej metody obliczeniowej, tak więc należy wydedukować nową metodę obliczeniową. Dlatego symulacja elementów skończonych jest obecnie szeroko stosowana do modelowania obliczeń różnych modeli, ponieważ może znacząco skrócić czas tradycyjnych obliczeń, jak również poprawić ich wydajność. Na podstawie mechaniki pękania przestudiowano WIN oraz ścieżki rozwoju pęknięć biorąc za przykład model mostu „Sutong”, zasymulowano małe pęknięcia na dwóch niebezpiecznych częściach mostu oraz zastosowano obciążenie pojazdem względem ceownika, aby przewidzieć ścieżki rozwoju pęknięć.
Źródło:
Archives of Civil Engineering; 2016, 62, 4/I; 153-169
1230-2945
Pojawia się w:
Archives of Civil Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effects of adenoidectomy of serum insulin-like growth factor-1 (IGF-1) and ghrelin in hypertrophied adenoids in children with otitis media with effusion
Autorzy:
Żelazowska-Rutkowska, Beata
Jacewicz, Klaudia
Kasprzycka, Edwina
Skotnicka, Bożena
Cylwik, Bogdan
Powiązania:
https://bibliotekanauki.pl/articles/1397400.pdf
Data publikacji:
2020
Wydawca:
Index Copernicus International
Tematy:
ghrelin
hypertrophied adenoid
insulin-like growth factor-1 (IGF-1)
Opis:
Aim: The aim of the current study was to assess the serum levels of insulin-like growth factor-1 (IGF-1) and ghrelin in hypertrophied adenoids in children suffering with or without otitis media with effusion before and after adenoidectomy. Material and methods: Serum IGF-1 and ghrelin concentrations were measured with specific enzyme-linked immunoassay (ELISA) methods. The study was carried out in 20 children with otitis media with effusion. The reference group comprised 24 children with hypertrophied adenoid, while control group included 19 children. Results: This mean values of IGF-1 in children with otitis media with effusion and children with hypertrophied adenoid before adenoidectomy were significantly lower than those found in healthy children. Serum levels of IGF-1 were higher after adenoidectomy. There was a significant difference of serum ghrelin levels between both examined groups and the control group. Conclusion: Our results suggest that adenoidectomy in children with hypertrophied adenoids and in children with otitis media with effusion significantly increases the level of IGF-1 in serum compared to before surgery through the effect of the GH-IGF-1 axis, which could contribute to children’s growth.
Źródło:
Polish Journal of Otolaryngology; 2020, 74, 4; 13-17
0030-6657
2300-8423
Pojawia się w:
Polish Journal of Otolaryngology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zaburzenia kaskady transformujących czynnikow wzrostu typu β w wybranych patologiach człowieka
Aberrations in the signalling cascade of transforming growth factor β type in selected human pathologies
Autorzy:
Zakrzewski, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/1032754.pdf
Data publikacji:
2012
Wydawca:
Łódzkie Towarzystwo Naukowe
Tematy:
transformujące czynniki wzrostu typu β - tgfβ
sygnalizacja
komórkowa
patofizjologia
polimorfizm
mutacje
transforming growth factor β type - tgfβ
cellular signalling
pathophysiology
polymorphism
mutations
Opis:
A transforming growth factor β type (TGFβ) cascade is a multifactorial signalling pathway, which controls the plethora of cellular processes responsible for human organism homeostasis. The importance of alterations of TGFβ-induced signalling remains unknown. Up till now, impaired TGFβ signalling has been observed in pathologies of the musculoskeletal, cardiovascular and reproductive systems. Abnormalities in the TGFβ pathway can be either genetically determined or appear as spontaneous disorders which emerged during embryonic development. Understanding the role of the TGFβ pathway in the aetiology of various diseases appears to be necessary as it may serve in developing new strategies for therapeutic or diagnostic methods.
Kaskada sygnalizacyjna transformujących czynników wzrostu typu β (TGFβ) stanowi indukowany przez wiele cytokin szlak przekazywania sygnału w komórce, pod kontrolą którego znajduje się szereg procesów komórkowych odpowiedzialnych za prawidłowe funkcjonowanie ludzkiego organizmu. Znaczenie zaburzeń sygnalizacji indukowanej czynnikami TGFβ pozostaje nadal nie do końca poznane. Niemniej jednak już na obecnym etapie badań stwierdzić można ich bezsprzeczny udział w patologiach układu kostno-mięśniowego, układu krwionośnego czy układu rozrodczego.
Źródło:
Folia Medica Lodziensia; 2012, 39, 2; 265-292
0071-6731
Pojawia się w:
Folia Medica Lodziensia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Elevated level of ambient glucose stimulates the synthesis of high-molecular-weight hyaluronic acid by human mesangial cells. The involvement of transforming growth factor β1 and its activation by thrombospondin-1
Autorzy:
Yevdokimova, Natalia
Powiązania:
https://bibliotekanauki.pl/articles/1041253.pdf
Data publikacji:
2006
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
mesangial cells
high glucose
transforming growth factor β1
hyaluronic acid
thrombospondin-1
Opis:
The dysregulation of the metabolism of glycosaminoglycan and protein components of extracellular matrix (ECM) is a typical feature of diabetic complications. High glucose-induced enrichment of ECM with hyaluronan (HA) not only affects tissue structural integrity, but influences cell metabolic response due to the variety of effects depending on the HA polymer molecular weight. TSP-1-dependent activation of TGFβ1 axis is known to mediate numerous matrix disorders in diabetes, but its role concerning HA has not been studied so far. In this work we demonstrated that 30 mM D-glucose increased the incorporation of [3H]glucosamine in high-molecular-weight (> 2000 kDa) HA of medium and matrix compartments of human mesangial cultures. Simultaneously, the synthesis of HA with lower molecular weight and HA degradation were not altered. The cause of the increased high-molecular-weight HA synthesis consisted in the up-regulation of hyaluronan synthase (HAS) 2 mRNA without alterations of the expression of HAS3, which generates HA of lower molecular weight. D-Glucose at 30 mM also stimulated the production of transforming growth factor β1 (TGFβ1), the excessive activation of which was determined by the up-regulation of thrombospondin-1 (TSP-1). The blockage of TGFβ1 action either by neutralizing anti-TGFβ1 antibodies or by quenching the TGFβ1 activation (with TSP-1-derived synthetic GGWSHW peptide) abolished the effect of high glucose on HAS2 mRNA expression and normalized the synthesis of HA. Exogenous human TGFβ1 had the same effect on HAS2 expression and HA synthesis as high glucose treatment. Therefore, we supposed that TSP-1-dependent TGFβ1 activation is involved in the observed high glucose effect on HA metabolism. Since high-molecular-weight HA polymers, unlike middle- and low-molecular weight HA oligosaccharides, are known to possess anti-inflammatory and anti-fibrotic functions, we suppose that the enrichment of mesangial matrix with high-molecular-weight HA may represent an endogenous mechanism to limit renal injury in diabetes.
Źródło:
Acta Biochimica Polonica; 2006, 53, 2; 383-393
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pentoxifylline and its active metabolite lisofylline attenuate transforming growth factor β1-induced asthmatic bronchial fibroblast-to-myofibroblast transition
Autorzy:
Wójcik-Pszczoła, Katarzyna
Hińcza, Kinga
Wnuk, Dawid
Kądziołka, Dominika
Koczurkiewicz, Paulina
Sanak, Marek
Madeja, Zbigniew
Pękala, Elżbieta
Michalik, Marta
Powiązania:
https://bibliotekanauki.pl/articles/1038759.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
theophylline
pentoxifylline
lisofylline
transforming growth factor type β
fibroblast-to-myofibroblast transition
asthma
Opis:
Bronchial asthma is characterized by persistent airway inflammation and airway wall remodeling. Among many different cells and growth factors triggering changes in bronchi structure, transforming growth factor β1-induced fibroblast to myofibroblast transition is believed to be very important. The aim of this study was to evaluate whether theophylline (used in asthma therapy) and two other methylxanthines (pentoxifylline and its active metabolite lisofylline), may affect transforming growth factor β1-induced fibroblast to myofibroblast transition in bronchial fibroblasts derived from asthmatic patients. We show here for the first time that selected methylxanthines effectively reduce transforming growth factor β1-induced myofibroblast formation in asthmatic bronchial fibroblast populations. PTX was found to be the most effective methylxanthine. The number of differentiated myofibroblasts after PTX, LSF and THEO administration was reduced at least twofold. Studies on the use of methylxanthines opens a new perspective in the development of novel strategies in asthma therapy through their two-pronged, anti-inflammatory and anti-fibrotic action. In the future they can be considered as promising anti-fibrotic drugs.
Źródło:
Acta Biochimica Polonica; 2016, 63, 3; 437-442
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The potential impact of the hypovitaminosis D on metabolic complications in obese adolescents - preliminary results
Autorzy:
Wójcik, Małgorzata
Janus, Dominika
Kalicka-Kasperczyk, Anna
Sztefko, Krystyna
Starzyk, Jerzy B.
Powiązania:
https://bibliotekanauki.pl/articles/986678.pdf
Data publikacji:
2017
Wydawca:
Instytut Medycyny Wsi
Tematy:
obesity
hypovitaminosis d
uric acid
arterial hypertension
fibroblast growth factor 23
fibroblast growth factor 19
adolescents
Opis:
Introduction and objective. Vitamin D deficiency is common in obesity; however, its contribution in the development of metabolic complications remains uncertain. The aim of the study was to examine the relationships between vitamin D status and metabolic complications. Materials and method. The results of blood pressure measurements, biochemical tests and ultrasound of the liver were compared in both groups. The study was conducted at the Children’s University Hospital in Krakow, Poland. 30 obese adolescents (mean 13.23y.o.); 18 with 25OHD levels <20ng/mL, 12 with 25OHD>20 ng/mL. Results. The vitamin D deficient group presented with significantly higher values of the diastolic blood pressure (125.9vs.115mmHg), uric acid level (384.7vs.301.5umol/L) and lower phosphorus level (1.4vs.1.65mmol/L), higher prevalence of arterial hypertension (44vs.8.3%), and liver steatosis (25vs.8.3%); lower, but not significantly, levels of fibroblast growth factor 23 and fibroblast growth factor 19. Conclusions. Hypovitaminosis D in obese adolescents is associated with higher prevalence of arterial hypertension, liver steatosis, elevated serum uric acid and low phosphorus levels. The potential contribution of the fibroblast growth factor 23 and fibroblast growth factor 19 in these complications development needs further investigation.
Źródło:
Annals of Agricultural and Environmental Medicine; 2017, 24, 4
1232-1966
Pojawia się w:
Annals of Agricultural and Environmental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The associations between the growth hormone/insulin-like growth factor-1 axis, adiponectin, resistin and metabolic profile in children with growth hormone deficiency before and during growth hormone treatment
Autorzy:
Witkowska-Sędek, Ewelina
Rumińska, Małgorzata
Stelmaszczyk-Emmel, Anna
Majcher, Anna
Pyrżak, Beata
Powiązania:
https://bibliotekanauki.pl/articles/1038412.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
adiponectin
resistin
metabolic profile
growth hormone/insulin-like growth factor-1 axis
growth hormone deficiency
children
Opis:
This study investigated associations between the growth hormone/insulin-like growth factor-1 (GH/IGF-1) axis, adiponectin, resistin and metabolic profile in 47 GH-deficient children before and during 12 months of GH treatment. 23 short age-matched children without growth hormone deficiency (GHD) or any genetic or chronic disorders were recruited as controls at baseline. Metabolic evaluation included measurements of adiponectin, resistin, IGF-1, total cholesterol (total-C), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), glucose, insulin, glycated haemoglobin (HbA1c), thyroid stimulating hormone (TSH) and free thyroxine (free T4) concentrations. The GH-deficient children had significantly higher adiponectin (p<0.05) and total cholesterol (p<0.05) levels, and a significantly lower level of resistin (p<0.05) than the controls. Resistin at 6 months of GH treatment significantly correlated with changes in height SDS in that period (r=0.35) and with the level of fasting insulin (r=0.50), the HOMA-IR (r=0.56) and the QUICKI (r=-0.53) at 12 months of therapy. Adiponectin level at 12 months of GH treatment was significantly associated with changes in HDL-C within the first 6 (r=0.73) and within 12 (r=0.56) months of therapy, while resistin significantly correlated with an increment in IGF-1 within 12 months of treatment (r=0.49) and with total-C at 12 months (r=0.56). Untreated GH-deficient children had higher adiponectin and lower resistin levels than healthy short children without GHD. Adiponectin and resistin levels did not change significantly during the first 12 months of GH therapy. Good responders to GH treatment had a tendency for higher resistin level during GH therapy, which positively correlates with the insulin resistance parameters.
Źródło:
Acta Biochimica Polonica; 2018, 65, 2; 333-340
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Acromegaly: the effect of somatostatin analogues on tumour volume shrinkage
Autorzy:
Witek, Przemysław
Gutowska, Marta
Powiązania:
https://bibliotekanauki.pl/articles/1064786.pdf
Data publikacji:
2016
Wydawca:
Medical Education
Tematy:
acromegaly
growth hormone
insulin-like growth factor 1
lanreotide
long-acting somatostatin analogues
octreotide
pasireotide
somatotroph pituitary adenoma
tumour volume reduction
Opis:
Acromegaly is a rare disease, caused by growth hormone (GH) hypersecretion and secondarily elevated insulin-like growth factor 1 (IGF-1) level. Nearly all patients with acromegaly suffer from somatotroph pituitary adenoma. The main goal of treatment is to normalise both GH and IGF-1 levels, which reduces symptoms, complications and mortality. Transsphenoidal selective adenomectomy performed by an experienced neurosurgeon is the first-line therapy. Therapy with somatostatin analogues (SSA) is used as a neoadjuvant treatment prior to surgery and in a persistent disease following the surgery. The long-acting somatostatin analogues reduce serum GH/IGF-1 levels and tumour volume. In this clinical review, mechanisms and role of 1st and 2nd generation somatostatin analogues in the treatment of patients with acromegaly are presented, with particular emphasis on the effects on somatotroph pituitary adenoma volume reduction.
Źródło:
OncoReview; 2016, 6, 4; A162-168
2450-6125
Pojawia się w:
OncoReview
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Endocrine Responses to Physical Training and Tribulus Terrestris Supplememtation in Middle-Age Men
Autorzy:
Wilk, Michał
Michalczyk, Małgorzata
Chycki, Jakub
Czuba, Miłosz
Roczniok, Robert
Gołaś, Artur
Zając, Adam
Maszczyk, Adam
Powiązania:
https://bibliotekanauki.pl/articles/1054899.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Szczeciński. Wydawnictwo Naukowe Uniwersytetu Szczecińskiego
Tematy:
growth hormone
insulin-like growth factor
steroidal saponins
supplementation
testosterone
Opis:
The aim of this study was to evaluate the effects of steroidal saponin supplementation on blood concentration of T, GH and IGF-1. The research involved 14 men between the age of 45 and 60 years. The duration of the experiment was 12 weeks. There were two series of laboratory tests. Independent tests were conducted at the beginning and after 12 weeks of the intervention. A two-way repeated measures ANOVA revealed a statistically significant effect of the intervention on the following variables: T-Ch (η2 = 0.542), HDL-Ch (η2 = 0.522), LDL-Ch (η2 = 0.587), T (η2 = 0.603), IGF-1 (η2 = 0.512) and GH (η2 = 0.621). Thus, FFM significantly increased while TBF and BM decreased in comparison to pre-intervention levels. The analyzed results indicate that treatment or supplementation of individual hormone deficiencies can be a successful form of counteracting the aging process. Nevertheless, the effects of TT supplementation on the concentration of T as well as GH and IGF-1, requires further studies, especially in middle-aged and older subjects, along with different exercise programs. The analyzed results indicate that treatment or supplementation of individual hormone deficiencies can be a major form of counteracting the aging process.
Źródło:
Central European Journal of Sport Sciences and Medicine; 2016, 13, 1; 65-71
2300-9705
2353-2807
Pojawia się w:
Central European Journal of Sport Sciences and Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mikologiczne skazenia zywnosci
Autorzy:
Wieczorek, C
Powiązania:
https://bibliotekanauki.pl/articles/825985.pdf
Data publikacji:
2003
Wydawca:
Polskie Towarzystwo Technologów Żywności
Tematy:
plesnie
przemysl spozywczy
zywnosc
zanieczyszczenia mikrobiologiczne
mikotoksyny
czynniki wzrostu
skazenie zywnosci
mould
food industry
food
microbiological contamination
mycotoxin
growth factor
food contamination
Opis:
W artykule opisano zanieczyszczenie żywności pleśniami i omówiono warunki sprzyjające wytwarzaniu mikotoksyn. Wzrost pleśni powoduje pogorszenie jakości lub zepsucie produktów spożywczych, co może prowadzić do zmiany wyglądu, nieprzyjemnego zapachu, obniżonej zdolności kiełkowania nasion, skażenia mikotoksynami i/lub alergii i infekcji u ludzi. Wysoka toksyczność metabolitów pleśni jest dużym zagrożeniem dla konsumentów. Tworzenie mikotoksyn następuje wyłącznie w wyniku wzrostu pleśni toksynotwórczych. Szczególny wpływ na rodzaj występujących pleśni ma skład żywności. Natomiast rozwój i wzrost pleśni w znaczącym stopniu uwarunkowane są: aktywnością wody (aw), temperaturą, wartością pH, zawartością O2 i CO2, rodzajem substratu i składem mikoflory.
The article describes results of food contamination by molds and conditions fostering mycotoxin contamination of foods. The molds growth leads to quality deterioration or spoiling of different kind of foodstuffs. It may result in an unpleasant odour and appearance of the product, reduced seed germination, mycotoxin pollution and/or human allergy and infection. The highly toxic fungal metabolites are particulary dangerous for consumers. Mycotoxins formation in foodstuffs takes place only as a result of growth of toxin-creating molds. Substrates composition influences specially the mold spectrum in foods. Whereas the mold growth and expansion are considerably determined by aw, temperature, pH, atmosphere and microbial competition.
Źródło:
Żywność Nauka Technologia Jakość; 2003, 10, 3; 119-129
1425-6959
Pojawia się w:
Żywność Nauka Technologia Jakość
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Transcriptional pattern of TGF-beta1 inhibitory effect on mouse C2C12 myoblasts differentiation
Autorzy:
Wicik, Z.
Sadkowski, T.
Jank, M.
Motyl, T.
Powiązania:
https://bibliotekanauki.pl/articles/30377.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
transforming growth factor-beta 1
myogenesis
microarray
DNA microarray
differentiation
myoblast
mouse
mice
muscle cell
myosin heavy chain
Opis:
The aim of the present study was to define the effect of TGF-β1 on C2C12 myoblasts myogenesis. TGF-β1 together with its receptor is a negative auto-paracrine regulator of myogenesis, which influences the proliferation, differentiation, and functions of muscle cells. TGF-β1 exerts highly significant inhibitory effect on differentiation of C2C12 mouse myoblasts manifested by the impairment of cell fusion and very low expression of myosin heavy chain. The study of differentiating C2C12 mouse myoblasts treated with TGF-β1 revealed 502 genes (436 down-regulated and 66 up-regulated) with statistically different expression. TGF-β1-regulated genes were identified to be involved in 29 biological processes, 29 molecular functions groups and 59 pathways. The strongest inhibiting effect of TGF-β1 was observed in the cadherin and Wnt pathways. The key-genes that could play the role of TGF-β1 targets during myoblasts differentiation was identified such as: Max, Creb1, Ccna2, Bax, MdfI, Tef, Tubg1, Cxcl5, Rho, Calca and Lgals4.
Źródło:
Polish Journal of Veterinary Sciences; 2010, 13, 4
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Local effect of progesterone infusion into ovarian artery on activin A and inhibin alpha-subunit secretion during the middle luteal phase in gilts
Autorzy:
Wasowska, B
Stefanczyk-Krzymowska, S.
Powiązania:
https://bibliotekanauki.pl/articles/30684.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
dimeric glycoprotein
activin
inhibin
growth factor-beta
progesterone infusion
ovarian artery
alpha-subunit
secretion
exogenous progesterone
local feedback
gilt
middle luteal phase
Opis:
The present study was undertaken to elucidate whether an increased, but physiological, amount of progesterone (P4) supplied to the porcine corpus luteum affects luteal secretion of activin A and inhibin a-subunit (Inha) in freely moving gilts. On day 9 of the estrous cycle (EC), both ovarian arteries and both ovarian veins of gilts (n=5) were cannulated. Progesterone was infused into the right ovarian arteries in gilts on days 10, 11 and 12 of the EC at a rate adequate to its physiological retrograde transfer found during the middle luteal phase of the EC. The P4 infusion rate was 0.62 μg/min (day 10), 2x0.62 μg/min (day 11) and 3x0.62 μg/min (day 12). The left ovarian arteries were infused with saline (control). Blood samples were collected from both ovarian veins on days 10-12 of the EC before and after P4 or saline infusion. The mean plasma activin A level in the ovarian vein ipsilateral to the P4-infused ovary was higher (PcO.OOOl) on days 10-12 of the EC than this found in the contralateral ovarian vein. The level of activin A in the ovarian vein ipsilataral to the infusion of P4 was higher on days 11 (PcO.Ol) and 12 (P<0.0001) and tended to be higher (P<0.07) on day 10 of the EC than this in contralateral ovarian vein. The level of Inha in the ovarian vein ipsilateral to the P4-infused ovary on days 10-12 of the EC was not significantly different (P>0.05) than this found in the contralateral ovarian vein. The results of the present study indicate that a local elevation of P4 concentration in blood supplying the ovary during the middle luteal phase of the porcine EC affects ovarian secretion of activin A. The effect of P4 on the secretion of activin A suggested the existence of a short regulatory loop of a positive feedback between P4 being retrogradely transferred into the ovary and the secretion of this peptide.
Źródło:
Polish Journal of Veterinary Sciences; 2010, 13, 1; 97-104
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rape glucosinolates and alfalfa saponins as allelopathic factors for lettuce seeds germination
Autorzy:
Waligora, D
Powiązania:
https://bibliotekanauki.pl/articles/66032.pdf
Data publikacji:
1997
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
glucosinolate
allelopathic factor
development
root hair
allelopathy
seed
germination
seed germination
oilseed rape
alfalfa
saponin
seedling growth
lettuce
Opis:
Secondary plant substances - glucosinolates and saponins reduced seed germination and seedling growth of lettuce. Saponins showed greater inhibitory effect on both germination and growth of lettuce seedlings than glucosinolates. The effect depended on the concentration of these compounds in the ground. Tested compounds caused abbreviation of roots, browning their tips and prevented root hair development.
Testowano wpływ roślinnych metabolitów wtórnych: saponin lucerny i glukozynolanów rzepaku na kiełkowanie nasion sałaty. Stwierdzono hamujący wpływ obu badanych związków na kiełkowanie. Znacznie silniejsze działanie wykazywały saponiny, przy czym efekt ten zależny był od ich stężenia w podłożu. Badane związki wpływały nie tylko na liczbę skiełkowanych nasion, ale również na wygląd siewek (skrócenie korzonków, brunatnienie ich końców, brak włośników).
Źródło:
Journal of Plant Protection Research; 1997, 37, 1-2
1427-4345
Pojawia się w:
Journal of Plant Protection Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Histopathologic and immunohistochemical lesions in liver of mink infected with Aleutian disease virus
Autorzy:
Valdovska, A.
Pilmane, M.
Powiązania:
https://bibliotekanauki.pl/articles/30104.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Aleutian disease
Aleutian mink disease parvovirus
animal infection
beta-defensin-2
histopathology
immunohistochemistry
liver
liver parenchyma
mink
nerve growth factor receptor
metalloproteinase
Opis:
Parvovirus of Aleutian disease causes mainly damage to kidneys, but immune complexes deposition and damage may occur also in other organs. In mink farms of Latvia the liver dystrophy or hepatic lipidosis of mink is widely distributed. The goal of this study was to examine probability of liver damage and regeneration of mink infected with Aleutian disease virus. Liver injury was assessed histologically. The mink liver demonstrated inflammation of liver parenchyma and foci of fatty liver. In immunohistochemistry, during liver regeneration the matrix metalloproteinases MMP-9, vascular endothelial growth factor and β-defensin 2 expressions were lower, but MMP-2 and nerve growth factor receptor p75 expression was increased.
Źródło:
Polish Journal of Veterinary Sciences; 2011, 14, 1
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Clinical usefulness of assessing VEGF and soluble receptors sVEGFR-1 and sVEGFR-2 in women with breast cancer
Autorzy:
Thielemann, A.
Baszczuk, A.
Kopczynski, Z.
Kopczynski, P.
Grodecka-Gazdecka, S.
Powiązania:
https://bibliotekanauki.pl/articles/50027.pdf
Data publikacji:
2013
Wydawca:
Instytut Medycyny Wsi
Tematy:
clinical usefulness
vascular endothelial growth factor
soluble receptor
woman
breast cancer
patient
human disease
tumour metastasis
Opis:
Introduction. The biological activity of VEGF depends on the presence of its specific receptors on the endothelial surface: VEGFR-1, VEGFR-2, and on their soluble forms sVEGFR-1 and sVEGFR-2. The binding of the membrane-bound receptors with VEGF affects the permeability, proliferation and migration of vascular endothelial cells. This creates the necessary conditions for the vascularisation of solid tumours and for the spread of remote metastases. The sVEGFR-1 and sVEGFR-2 receptors are believed to be natural inhibitors of VEGF. Objective. To determine the clinical usefulness of VEGF and the sVEGFR-1 and sVEGFR-2 receptors level assay in women with primary breast cancer. The assessment also took into account: patient’s age, stage of the disease, histological grade, status of the axillary lymph nodes and size of the primary tumour. Material and methods. The concentrations of VEGF, sVEGFR-1 and sVEGFR-2 were ascertained in 103 women with primary breast cancer. The concentrations of VEGF in the plasma, and those of the soluble receptors sVEGFR-1 and sVEGFR-2 in the serum, were assessed by ELISA, R&D Systems. Results. The study found significantly raised concentrations of VEGF, sVEGFR-1 and sVEGFR-2 in the serum of women with breast cancer, relative to the values obtained from the control group. It was found that with increasing clinical stages of the disease, the levels of VEGF and concentrations of sVEGFR-1 and sVEGFR-2 also increased. Similar findings were noted when assessing the degree of the histological grade of the tumours. Significantly higher values of VEGF protein and the assessed receptors were obtained from women with metastases to the axillary lymph nodes. A positive relationship, though without statistical significance, was noted between the concentration of sVEGFR-2 and the size of the tumour. Conclusions. The high concentrations of the VEGF cytokine and the sVEGFR-1 and sVEGFR-2 receptors in women with breast cancer are responsible for giving rise to the processes of tumour angiogenesis. The concentrations of the VEGF protein and the soluble forms of the receptors sVEGFR-1 and sVEGFR-2 in the serum of breast cancer patients showed positive correlations with the clinical stage of the disease. These results point to the usefulness of VEGF assessment and its soluble receptors in the clinical evaluation of patients with breast cancer.
Źródło:
Annals of Agricultural and Environmental Medicine; 2013, 20, 2
1232-1966
Pojawia się w:
Annals of Agricultural and Environmental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł

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