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1

The effect of fasting on the ultrastructure of the hypothalamic arcuate nucleus in young rats

100%
Kubasik-Juraniec J., Knap N.
Folia Morphologica
|
2009
|
tom 68
|
nr 3
In the present study, we described ultrastructural changes occurring in the neurons of the hypothalamic arcuate nucleus after food deprivation. Young male Wistar rats (5 months old, n = 12) were divided into three groups. The animals in Group I were used as control (normally fed), and the rats in Groups II and III were fasted for 48 hours and 96 hours, respectively. In both treated groups, fasting caused rearrangement of the rough endoplasmic reticulum forming lamellar bodies and membranous whorls. The lamellar bodies were rather short in the controls, whereas in the fasting animals they became longer and were sometimes participating in the formation of membranous whorls composed of the concentric layers of the smooth endoplasmic reticulum. The whorls were often placed in the vicinity of a very well developed Golgi complex. Some Golgi complexes displayed an early stage of whorl formation. Moreover, an increased serum level of 8-isoprostanes, being a reliable marker of total oxidative stress in the body, was observed in both fasting groups of rats as compared to the control. (Folia Morphol 2009; 68, 3: 113–118)
2

Ultrastructural observations on the hypothalamic arcuate nuclei of aged rats in the fasting/refeeding model

100%
Kubasik-Juraniec J., Knap N.
Folia Morphologica
|
2009
|
tom 68
|
nr 2
The arcuate nucleus of the hypothalamus (ARH) is involved in the control of energy homeostasis. This is the first study on the ultrastructural response of ARH neurons in aged rats after short-term fasting and subsequent refeeding. Male Wistar rats (24 weeks old) were fasted for 48 or 96 hours and were then refed for 24 hours. The controls were normally fed. The rats received water ad libitum. In both groups of fasting animals, we observed a rearrangement of the arcuate rough endoplasmic reticulum (RER) and Golgi complexes to form membranous whorls. Moreover, refeeding for 24 hours did not reverse this process. The RER was frequently found to be well organized into lamellar bodies composed of several cisternae. The membranous whorls were composed of concentric layers of endoplasmic reticulum and Golgi complexes. In addition, multiform lipofuscin granules were observed in close relationship with Golgi complexes and membranous whorls. Lipofuscin granules within the neurons of the arcuate nucleus are assumed to be a morphological manifestation of oxidative stress phenomena, which are presumably implicated in the formation of membranous whorls in both fasting and fasting/refed animals. This observation correlates with a significant increase in 8-isoprostane serum levels in the fasting and fasting/refed animals as compared to the fed control rats. (Folia Morphol 2009; 68, 2: 79–83)
3

Determination of nucleotides and its metabolic products in human saliva

80%
Kochanska B., Smolenski R. T., Knap N.
Cellular and Molecular Biology Letters
|
1999
|
tom 04
|
nr 3
4

Determination of adenine nucleotides and their metabolites in human saliva

80%
Kochanska B., Smolenski R. T., Knap N.
Acta Biochimica Polonica
|
2000
|
tom 47
|
nr 3
The profile and normal concentrations of nucleotide metabolites in human saliva and reproducibility of these determinations were analyzed. Samples of human saliva collected from healthy individuals at weekly intervals, were deproteinized and analysed for the content of adenine nucleotides and their metabolites by reversed-phase HPLC. Initial ATP, hypoxanthine and uric acid concentrations were 0.52 0.15 µM, 1.91 0.37 µM and 184 22 µM respectively. A substantial individual variation persisted within 3 weeks of sampling excepted hypoxanthine which showed some unrelated variations. Determination of nucleotides and their catabolites in saliva due to its simplicity and reproducibility, may be of clinical value in diagnosis of local or systemic disorders.
5
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Rhizoctonia solani AG5 and its offspring – morphology and sensitivity to fungicides

71%
Hendel P., Moliszewska E., Nabrdalik M., Kudrys P., Knap N.
Acta Mycologica
|
2022
|
nr 57
6

Effect of gallic acid and its lauryl derivative on physical state of cell membrane lipids and cell cycle of human osteosarcoma 143B cell line

71%
Nowak J., Trzmiel A., Zgoda W., Knap N., Wozniak M.
Acta Biochimica Polonica
|
2003
|
tom 50
|
nr Supplement 1
7

Changes in mitochondrial superoxide ion production in osteosarcoma 143B cells after dihydroorotate dehydrogenase inhibitors treatment

71%
Spodnik J., Wozniak M., Karbowski M., Knap N., Wakabayashi T.
Acta Biochimica Polonica
|
2003
|
tom 50
|
nr Supplement 1
8

Ultrastructural response of arcuate nucleus neurons to fasting in aged rats

71%
Kubasik-Juraniec J., Zauszkiewicz-Pawlak A., Kotlarz G., Wozniak M., Knap N.
Folia Morphologica
|
2009
|
tom 68
|
nr 4
218-223
The arcuate nucleus of the hypothalamus (ARH) is involved in the control of energy homeostasis. Leptin — an adipocyte derived hormone — is known to act on the hypothalamic nuclei and thus to control body weight by food intake reduction. Oxidative stress is believed to be implicated in leptin signalling. However, its relevance for leptin-induced signal transduction within ARH remains unclear. The goal of the study was to investigate the effect of fasting on morphological alterations of the neuronal endoplasmic reticulum/Golgi network as well as on the expression of leptin receptors in the arcuate nucleus of aged rats. Male Wistar rats, aged 24 months, were fasted for 96 hours. The control animals were fed ad libitum. Membranous whorls in the ARH neurons were visualized using the electron microscopy technique. Leptin receptors in the membranes of ARH neurons were determined immunohistochemically (IHC), and soluble leptin receptors in the plasma as well as plasma isoprostanes were quantified immunochemically (ELISA). An intense formation of membranous whorls was observed, directly associated with the cisternae of the rough endoplasmic reticulum, as well as lamellar bodies. Interestingly, the whorls were often localized near a well-developed Golgi complex. Moreover, some Golgi complexes displayed an early stage of whorl formation. Groups of residual lipofuscin granules were found in the immediate proximity of the whorls. An increased immunoreactivity with neuronal leptin receptors suggests that hypersensitive neurons may still effectively respond to the fasting serum levels of leptin, mediating ultrastructural transformation of ARH neurons during short- -term fasting. Having observed a significant accumulation of lipofuscin granules and a marked increase of total 8-isoprostane serum level in the fasting rats, we hypothesize that signal transduction within the neurons of ARH is dependent on oxidative stress phenomena. (Folia Morphol 2009; 68, 4: 218–223)
9

Białkowe fosfatazy tyrozynowe – endogenne marker stresu oksydacyjnego

61%
Kuban-Jankowska A., Gorska M., Debicki A., Popowska U., Knap N., Wozniak M.
Postępy Biochemii
|
2010
|
tom 56
|
nr 3
10

Localized changes within membrane of neuroblastoma SN56 cells induced by amyloid (25–35) peptide

61%
Swirydowicz S., Madziar B., Jankowska A., Bielarczyk H., Kulawiak-Galaska D., Knap N., Wozniak M.
Acta Biochimica Polonica
|
2003
|
tom 50
|
nr Supplement 1
11

Dual effect of 2-methoxyestradiol on cell cycle events in human osteosarcoma 143B cells

61%
Golebiewska J., Rozwadowski P., Spodnik J. H., Knap N., Wakabayashi T., Wozniak M.
Acta Biochimica Polonica
|
2002
|
tom 49
|
nr 1
We have demonstrated for the first time that the steroid metabolite, 2-methoxy- estradiol (2-ME) is a powerful growth inhibitor of human osteosarcoma 143 B cell line by pleiotropic mechanisms involving cell cycle arrest at two different points and apoptosis. The ability of 2-ME to inhibit cell cycle at the respective points has been found con­centration dependent. 1 uM 2-ME inhibited cell cycle at G1 phase while 10 uM. 2-ME caused G2/M cell cycle arrest. As a natural estrogen metabolite 2-ME is expected to perturb the stability of microtubules (MT) in vivo analogously to Taxol — the MT bind­ing anticancer agent. Contrary to 2-ME, Taxol induced accumulation of osteosarcoma cells in G2/M phase of cell cycle only. The presented data strongly suggest two differ­ent mechanisms of cytotoxic action of 2-ME at the level of a single cell.
12

Capase-3 activation in human osteosarcoma 143B cells proceeds through an early cell membrane fluidity perturbation

51%
Gil A., Trzmiel A., Niemczyk E., Kedziora J., Spodnik J., Knap N., Wakabayashi T., Swirydowicz S., Wozniak M.
Acta Biochimica Polonica
|
2003
|
tom 50
|
nr Supplement 1
13

Effect of pentoxifylline on proteinuria, markers of tubular injury and oxidative stress in non-diabetic patients with chronic kidney disease - placebo controlled, randomized, cross-over study

51%
Renke M., Tylicki L., Rutkowski P., Knap N., Zietkiewicz M., Neuwelt A., Aleksandrowicz E., Lysiak-Szydlowska W., Wozniak M., Rutkowski B.
Acta Biochimica Polonica
|
2010
|
tom 57
|
nr 1
119-123
 Background: Inhibition of the renin-angiotensin-aldosterone system (RAAS) with angiotensin converting enzyme inhibitors (ACEI) and/or angiotensin II subtype 1 receptor antagonists (ARB) is a common strategy used in the management of patients with chronic kidney disease (CKD). However, there is no universal therapy that can stop progression of CKD. Pentoxifylline (PTE) is a non-specific phosphodiesterase inhibitor with anti-inflammatory properties. It has been reported to have promising effects in CKD treatment. Methods: In a placebo-controlled, randomized, cross-over study we evaluated the influence of PTE (1200 mg/day) added to RAAS blockade on proteinuria, surrogate markers of tubular injury and oxidative stress-dependent products in 22 non-diabetic patients with proteinuria (0.4-4.3 g per 24 h) with normal or declined kidney function [eGFR 37-178 mL/min]. In an eight-week run-in period, therapy using ACEI and/or ARB was adjusted to achieve a blood pressure below 130/80 mm Hg. Next, patients were randomly assigned to one of two treatment sequences: PTE/washout/placebo or placebo/washout/PTE. Clinical evaluation and laboratory tests were performed at the randomization point and after each period of the study. Results: The PTE therapy reduced proteinuria (by 26 %) as compared to placebo. There were no differences in α1-microglobulin, urine excretion of N-acetyl-β-d-glucosaminidase (NAG), hsCRP, the urinary excretion of 15-F2t-isoprostane, blood pressure (BP), eGFR and serum creatinine between the PTE and placebo groups. Conclusion: Pentoxifylline may decrease proteinuria in non-diabetic patients with CKD.
14

Dynamics of estrogen-induced oxidative stress

42%
Kobiela J., Stefaniak T., Krajewski J., Kalinska-Blach B., Zurawa-Janicka D., Lachinski A., Gackowski D., Olinski R., Nowak J., Knap N., Lipinska B., Sledzinski Z., Wozniak M.
Acta Biochimica Polonica
|
2007
|
tom 54
|
nr 2
The objective of this study was to assess the dynamics of oxidative damage to cellular macromolecules such as proteins, lipids and DNA under conditions of oxidative stress triggering early stages of estrogen-dependent carcinogenesis. A rodent model of carcinogenesis was used. Syrian hamsters were sacrificed after 1, 3, 5 h and one month from the initial implantation of estradiol. Matching control groups were used. Kidneys as target organs for estradiol-mediated oxidative stress were excised and homogenized for biochemical assays. Subcellular fractions were isolated. Carbonyl groups (as a marker of protein oxidation) and lipid hydroxyperoxides were assessed. DNA was isolated and 8-oxodGuo was assessed. Electron paramagnetic resonance spectroscopy was used to confirm the results for lipid peroxidation. Exposition to estradiol in the rodent model leads to damage of macromolecules of the cell, including proteins and DNA, but not lipids. Proteins appear to be the primary target of the damage but are closely followed by DNA. It has previously been speculated that protein peroxides can increase DNA modifications. This time sequence was observed in our study. Nevertheless, the direct relation between protein and DNA damage still remains unsolved.
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