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  • Author: Agnieszka Pedrycz x
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Influence of hyperbaric oxygenation and its use in urinary tract diseases

Abstract

In this publication, we adduce examples of the use of hyperbaric oxygen therapy in urinary tract diseases. Hyperbaric oxygen therapy has been proved to have a positive influence on the kidneys of animals with diabetes, sepsis or undergoing chemotherapy. In the literature, we can also find many examples of the use of hyperbaric therapy with good clinical outcomes in human patients with prostatic hypertrophy, pyelonephritis, and hemorrhagic cystitis. The first trials of this kind of treatment of urinary tract diseases were started at the end of the twentieth century. In spite of the promising results, and numerous reports on the effectiveness of this non-invasive method of treatment, it is not currently used on a regular basis.

Because many factors such as time, multiple applications, the parameters used in the hyperbaric chamber as well as the medications taken by the patient affect the quality of the result, further studies are needed to make hyperbaric therapy more suitable and safer for each patient.

Open access
Adriamycin - efficacy and possible adverse effects

Abstract

Adriamycin (doxorubicin) is a chemical substance in the anthracycline class with a wide range of applications in oncology and hematology. The mechanism of action of Adriamycin is related to formation of irregular bonds between nucleobases of DNA and inhibition of key enzymes of DNA synthesis - topoisomerase I and II as well as to formation of free radicals damaging DNA.

A major limitation in the drug use is associated with its adverse effects such as cardiotoxicity and hepatotoxicity.

The mechanism of myocardial injury by Adriamycin is linked to an increase in oxidative stress associated with impaired mitochondrial function and structure.

Cardiotoxicity of anthracyclines is classified as: acute, chronic or late (delayed).

Hepatotoxicity of Adriamycin as a damage of the liver is associated with a dysfunction of this organ. Adriamycin studies have shown increased level of transaminase present in 40% of patients treated with Adriamycin. The state was transient and asymptomatic, returning to the initial level even when treatment continued.

Knowledge of cancer diseases contributed to a successive creation of two improved forms of Adriamycin (doxorubicin) – nonpegylated and pegylated formulas of the drug.

The mechanism of anticancer effects of liposomal Adriamycin is similar to the mechanism of conventional Adriamycin, but placement of the molecules of active substance in liposomes has significant influence on the distribution of the drug.

In order to increase the distribution of the drug, a special form of liposomal Adriamycin has been created by covering the surface of the liposomes with a hydrophilic polymer - (MPEG). This process, known as pegylation, decreases the interactions between the lipid bilayer membrane and the plasma components. Pegylated form of the drug is associated with a higher incidence of acute complications.

Open access
Mechanisms promoting and inhibiting the process of proteasomal degradation of cells

Abstract

Defects in the process of degradation of unneeded cellular proteins underlie many diseases. This article discusses one of the most important systems of removal of abnormal proteins. It describes the process of ubiquitination of proteins for proteasome degradation. It also describes the structure of the 26S and 20S proteasomes and the mechanism of ubiquitin-proteasome system. Proteasome proteolytic system is highly specialized and organized. Protease-proteasome 26S is particularly important for proper cell functioning. It recognizes and degrades marked proteins. Inhibition of proteasome pathway leads to cell cycle arrest and apoptosis.

Efficient degradation of cellular proteins by UPS (the ubiquitin - proteasome system) - is important for signal transduction, transcriptional regulation, response to stress and the activity control of cell receptors.

The development of many diseases has its origin in the dysfunction of the UPS route. This group includes diseases such as cancer, neurodegenerative disorders, immune-mediated diseases and infectious diseases. Development of effective methods for pharmacological intervention in the functioning of this system has become a great challenge. The use of specific, low molecular-weight proteasome inhibitors and enzymes catalyzing the ubiquitination gives hope for new, targeted therapies.

Open access
Reactive oxygen radicals – the therapeutic effectiveness of antioxidants

Abstract

Oxidative stress occurring in cells is a consequence of an excessive activity of reactive oxygen forms, resulting from an imbalance between the release of free oxygen radicals and their removal from the cell by antioxidant systems. 90% of reactive oxygen radicals emerge in mitochondrial respiratory chain during an incomplete four-electron oxygen reduction. The remaining 10% originate from different reactions occurring in the cell. The established compounds are characterised by a short half-life and are highly reactive. Sparse quantities of free oxygen radicals have a positive effect on cell functions. Oxidative stress leads to damage in cellular membranes, enzymatic and non-enzymatic proteins, as well as DNA. Therapy with antioxidants as exogenous dietary supplements aims at preventing or reducing the risk of development of diseases involving the presence of the oxygen radicals. Whether the antioxidant therapy will bring positive or negative effects depends on numerous factors that need to be considered before their inclusion in the applied treatment.

Open access
The impact of carbohydrate intake on the behavior and cognitive functions of children and adolescents

Abstract

Introduction. Although carbohydrates are the most commonly studied nutrients regarding their influence on cognitive functions, there is no unequivocal agreement on whether this influence really exists and what its manifestations are.

Aim. This study is a literature review of research on the association between sugar intake, behavior and cognitive functions in children population.

Material and methods. The analysis of the studies on the carbohydrate intake and its impact on behavior and cognitive functions of children and adolescents on the basis of MEDLINE database was conducted. The studies were found in PubMed Internet search engine. The following words were implemented in various combinations: “sugar”, “carbohydrate”, “glycemic index”, “GI”, “glucose” as well as “cognition”, “cognitive”, “learning”, “memory”, “attention”, “behavior”, “hyperactivity”. The number of 27 publications was chosen and the information they contained was analyzed.

Results. Despite multiple studies on the impact of carbohydrate intake and their glycemic index on cognitive functions, there is still no agreement on this issue. Multiple studies indicate the association between glycemic index and cognitive processes. The positive impact of low GI breakfast intake on the concentration and memory is relatively frequently emphasized. The concept that indicates the association between sugar intake and hyperactive behavior among children also has not been unequivocally confirmed in the analyzed studies – contrarily – some of them indicated lack of such relationship. The placebo effect may be the explanation for the above concept. The association between the number of carbohydrates in diet and sleep disorders also has not been proved.

Conclusions. Although there are no unequivocal scientific foundations to limit the intake of simple sugars and consume polysaccharides with low GI to improve behavior and cognitive functions, such actions are consistent with a healthy diet and should be recommended for children and adolescents.

Open access
Autophagy - Adaptive Molecular Mechanisms in Condition of Starvation

Abstract

Autophagy is an extremely old process during which long-lived proteins and cellular organelles are removed by means of lysosomes. Autophagy may be caused by cellular stress mechanisms. Research has proven that autophagy plays a key role in obtaining nutrients and adapting to the conditions of starvation. Owing to this, it takes part in maintaining homeostasis in cytoplasm and cell nucleus. This objective may be achieved through a number of ways. Depending on the manner in which a substrate connects with the lysosome, we can talk about macroautophagy and microautophagy. Additionally, some authors also distinguish a chaperone-mediated autophagy. The article presented below describes molecular mechanisms of each type of autophagy and focuses particularly on macroautophagy, which is the best understood of all the autophagy types.

Open access
Assessment of L-Arginine as an Effect of Exogenous Nitric Oxide (No) on Expression of Markers of Cellular Stress in Rats’ Hepatocytes

Abstract

The aim of this study was immunohistochemical evaluation of heat shock protein (Hsp70) and p-53 proteins in the Larginine- induced cellular stress in hepatocytes of rats. Sixteen white Wistar female rats were divided into two equal groups. The rats from the experimental group received per os 40 mg/kg b.w. of L-arginine every day for 2 weeks and were decapitated after 3 weeks of the experiment. The rats from the control group received in the same manner 2 ml of distilled water and were decapitated after 3 weeks of the experiment. After decapitation specimens from the liver were collected, fixed in 10% formalin, and then embedded in paraffin blocks. Proteins Hsp70 and p-53 were detected on slides using the standard three step immunohistochemical method. The quantitative evaluation of Hsp70 and p-53 expression showed that the area of positive staining in the liver of the experimental rats (Hsp70 305,763.00 μm² +/-58,289.66, p-53 9,551.42 μm² +/-1,078.86) was comparable to that in the control groups (Hsp70 291,636.80 μm² +/-34,492.31, p-53 14,104.67 μm² +/-3,571.35). Our experiment showed, that L-arginine as a precursor of exogenous nitric oxide given to rats in dose similar to that used in pregnant women treated for hypertension did not exhibit an influence on hepatocytes.

Open access
The possibilities of stem cell application in regenerative medicine

Abstract

Stem cells are characterized by their ability to self-renew and differentiate into various cell types. They offer great potential for a wide range of applications, however, medical studies on the use of embryonal stem cells are largely limited to bioethical issues searching for alternative sources of stem cells, which include isolating cells from adult organisms or inducing pluripotentiality of somatic cells by administration of transcription factors. Nowadays, stem cells are used to study the mechanisms of cell differentiation and treat diseases that are commonly considered to be incurable, such as diabetes and neurodegenerative diseases, as well as enable regeneration of skin damage and myocardium. This review introduces the subject of stem cells, their sources and application in regenerative medicine.

Open access
Ultrastructure of Renal Tubular Epithelial Cells Of Rat’s Kidneys after Administration of L-Arginine

Abstract

Sixteen white Wistar female rats were divided into two equal groups. Experimental group received per os 40 mg/kg b.w. of L-arginine, every other day for 2 weeks and were decapitated after 3 weeks of the experiment. Control rats received in the same manner 2 ml of distilled water and were decapitated after 3 weeks of the experiment. The renal lesions observed under electron microscope were of focal character and concerned only the experimental group. The tubules with necrotic cells were observed among normal tubules or single normal epithelial cells of the tubular wall. The boundaries between epithelial cells of the tubule wall were blurred. The mitochondria indicated abnormal structure. Numerous lysosomes and peroxysomes with dark, homogenous content were observed. The rough endoplasmic reticulum had widened channels and was focally completely destroyed. The nucleus of damaged cells was most commonly located in one of the cell poles; its shape was changed and visibly smaller than the nuclei of normal cells. Condensation and peripherally located chromatin were noticed. The lesions observed were characteristic for apoptotic cells.

Open access
Assessment of the Effects of Rehabilitation on Balance Impairment in Patients After Ischemic Stroke According to Selected Tests and Scales

Abstract

Cerebral stroke is one of the most important issues for modern medicine. Despite the fact that numerous activities have been undertaken for the purpose of raising awareness and significance of prevention, this condition still remains one of the main reasons behind disability. The objective of the work was to assess the effects of the type of therapy, age and period from the incident occurrence, on the progress of rehabilitation of imbalance and body stability observed in a group of researched patients, on the basis of results obtained according to the Berg Balance Scale, tandem balance test, Kwolek’s loading symmetry index and Timed Up and Go test. The test group comprised of 55 post-stroke patients. The group consisted of 29 women (52.73%) and 26 men (47.27%). The average age of the subjects was 61.02 years (age range between 33-85 years). A number of the patients were subjected to rehabilitation with the use of classic kinesitherapy, whereas the remaining group underwent rehabilitation based on the proprioceptive neuromuscular facilitation method (PNF).

Open access