41 research outputs found
The role of vitamin C in skin care and health
Background. The effect of vitamin C on the skin. The skin is a protective barrier against harmful factors from the external environment, which is due to its unique structure. The skin contains vitamin C in various concentrations depending on the individual layers. Skin keratinocytes have the capacity to accumulate high concentrations of vitamin C, which may reduce inflammation caused by excessive exposure to UV irradiation.
Aim of the study. The aim of the study was to systematize knowledge about the topical use of vitamin C in the care or treatment of skin defects based on a literature review and to indicate potential benefits in damages related to the overproduction of reactive oxygen species (ROS) and the skin aging process.
Materials and methods. The literature review was performed by searching scientific databases: PubMed and Google Scholar. The search for relevant articles on the role of vitamin C in the skin was carried out using the following keywords: “vitamin C", "ascorbic acid", "magnesium ascorbyl phosphate", "ascorbyl-6-palmitate", "skin", "photoprotection", "photoaging". In order to increase the efficiency of work, the authors developed a concept of the publication that included division into subchapters that were assigned to individual authors in order to avoid duplicating information while editing the manuscript. The described methodology allowed for obtaining reliable information.
Results. Vitamin C protects the keratinocyte from apoptosis and increases cell survival. It acts as an antioxidant that plays an important role by stimulating collagen synthesis and assisting in antioxidant protection against UV-induced photodamage. Vitamin C also influences gene expression of antioxidant enzymes, the organisation and accumulation of phospholipids, and promotes the formation of the stratum corneum and the differentiation of the epithelial cells in general. The provision of vitamin C to the skin greatly assists wound healing and minimises raised scar formation.
Vitamin C supplementation for nutritional purposes is also important and can be combined with topical application. The effect of the comprehensive action of vitamin C is to protect tissues against oxidative damage by removing free radicals that damage the most important structures of the body: cell membranes, DNA and proteins.
Conclusions. The effectiveness of vitamin C affects the condition of the skin and the rate of its aging. This study contains examples of research methods for reconstructed human epidermis or keratinocytes, but the literature review shows that these models lack other skin components such as fibroblasts, Langerhans cells, melanocytes and hair follicles. The human skin model has been developed in laboratories and is currently limited by the lack of many critical biological and structural features of the skin. Engineering a human skin equipped with, among others, into immune cells and capable of generating all components, including appendages, is a major challenge. Therefore, further research is needed to elucidate the exact mechanisms of action of vitamin C using a human skin model that containing other skin components
Primary sclerosing cholangitis - an insidious enemy of the liver - case report
Background and introduction
Primary sclerosing cholangitis (PSC) is a chronic liver disease with features of cholestasis as a result of inflammation and damage to the bile ducts, which can eventually lead to liver fibrosis and parenchymal failure at an advanced stage.
Case Report
A 22-year-old man was admitted urgently to the Department of Gastroenterology for complaints of abdominal pain, weakness and tarry stools. A panel of detailed examinations was performed to establish the diagnosis. An abdominal ultrasound scan showed significant enlargement of the liver and spleen. Gastroscopy revealed variceal columns of II degree in the lower esophagus, which were cauterized. Laboratory tests confirmed anemia, reduced platelet and white blood cell counts, increased activity of ALT, ASP, GTP, ALP and slight elevation of total bilirubin in the blood. Based on the clinical disease manifestation and the results of diagnostic tests, cirrhosis of unknown origin was suspected. Subsequent magnetic resonance cholangiopancreatography (MRCP) revealed the presence of multiple strictures in the intra- and extrahepatic bile ducts and gave rise to the diagnosis of PSC. Pharmacological treatment was administered. Currently, the patient remains under the close care of the Transplant Clinic, where he undergoes regular checks of liver function, and endoscopic variceal ligation (EVL) as required.
Discussion with conclusions
The case presented here shows that the course of PSC can be insidious and asymptomatic. Despite the absence of clinical symptoms, the disease can lead to the development of advanced cirrhosis even in patients of young age and be diagnosed as late as at the decompensated stage, when the only treatment option remains organ transplantation
Proton pump inhibitor (PPI) administration and Clostridioides difficile infection - is this a real clinical problem? A critical review of the literature
Background: Proton pump inhibitors (PPIs) are widely used drugs that reduce gastric acid secretion. In recent years, there has been a gradual increase in their use. The safety of prolonged PPI therapy and the potential for cumulative side effects of these drugs raise legitimate concerns. An association between PPI administration and the risk of Clostridioides difficile infection has been suggested. The findings regarding this phenomenon require further unequivocal verification.
Material and methods: A review of publications obtained from the PubMed database and published between 2016-2023. Based on the keywords "proton pump inhibitor", "PPI" and "Clostridium", 132 articles were selected. Finally, 6 meta-analyses were included in the analysis.
Results: Studies conducted in recent years have shown a statistically significant increase in the risk of C. difficile infection in patients taking PPIs compared to those who avoid this therapy. The aforementioned relationship was observed in both adults and pediatric patients. One study proved that the risk remained high even up to 1 year after the end of treatment. The described relationship is still a matter of debate due to the fact that patients using antacids are usually elderly, have several comorbidities and a higher risk of developing C. difficile infection regardless of PPI use.
Conclusions: The relationship between the use of PPIs and the risk of developing C. difficile infection is still controversial, which justifies the need for continued clinical trials to objectively resolve this issue. PPIs exert high efficacy in the treatment of acid-dependent diseases, but due to the many ambiguities surrounding possible side effects, caution in their administration seems warranted, especially for long-term therapy in elderly patients with polypharmacy
The role of probiotics in the treatment of depressive disorders. A critical review
Depressive disorders are a widespread problem in modern medicine. According to current data from the World Health Organisation, an estimated 280 million people worldwide suffer from depression. In recent years, there have been reports of a correlation between the composition of the gut microbiota and the development of depressive disorders and attempts to modify it through the use of psychobiotics.
The literature from the PubMed database published between 2018-2023 has been explored. 596 articles were selected based on the keywords "probiotics" and "depression". Six randomized clinical trials were finally included in the analysis.
As defined elsewhere, psychobiotics are probiotic bacteria which supplemented in adequate amounts, interact with the gut-brain axis and show beneficial effects on patients' mental health. Results from recent RCTs suggest that daily probiotic supplementation significantly reduces the severity of depression compared to placebo (p<0.05). Additionally, this effect may be enhanced by the combined use of a probiotic with a prebiotic. Furthermore, some researchers indicate that probiotics may lead to significant improvements in cognitive function in patients suffering from depressive disorders.
In conclusion, intestinal dysbiosis may be an important factor leading to the development of mental illness. Results of recent studies suggest that specific strains of probiotic bacteria may offer therapeutic benefits in the treatment of the aforementioned disorders. However, further clinical studies are needed to objectively confirm the relationship between gut microbiota composition and the development of depression
The role of probiotics in the treatment of depressive disorders. A critical review
Depressive disorders are a widespread problem in modern medicine. According to current data from the World Health Organisation, an estimated 280 million people worldwide suffer from depression. In recent years, there have been reports of a correlation between the composition of the gut microbiota and the development of depressive disorders and attempts to modify it through the use of psychobiotics.
The literature from the PubMed database published between 2018-2023 has been explored. 596 articles were selected based on the keywords "probiotics" and "depression". Six randomized clinical trials were finally included in the analysis.
As defined elsewhere, psychobiotics are probiotic bacteria which supplemented in adequate amounts, interact with the gut-brain axis and show beneficial effects on patients' mental health. Results from recent RCTs suggest that daily probiotic supplementation significantly reduces the severity of depression compared to placebo (p<0.05). Additionally, this effect may be enhanced by the combined use of a probiotic with a prebiotic. Furthermore, some researchers indicate that probiotics may lead to significant improvements in cognitive function in patients suffering from depressive disorders.
In conclusion, intestinal dysbiosis may be an important factor leading to the development of mental illness. Results of recent studies suggest that specific strains of probiotic bacteria may offer therapeutic benefits in the treatment of the aforementioned disorders. However, further clinical studies are needed to objectively confirm the relationship between gut microbiota composition and the development of depression
Analysis of heat transfer coefficient for variable spatial orientation of a minichannel with an enhanced surface at incipience of boiling
The paper presents flow boiling heat transfer of FC-72 in 1 mm depth, 40 mm width minichannel where a foil with evenly distributed recesses on one side acts as a heating surface. The minichannel is set at various angles, i.e. 0, 45, 90, 135 and 180 degrees inclinations in relation to the horizontal plane. The plain side of the foil is observed to determine the surface temperature by liquid crystal thermography. Two heat transfer models: one- and two-dimensional are proposed to calculate local heat transfer coefficients. In the two-dimensional approach the inverse problem in the heating wall is solved by the semi-analytical method based on Trefftz functions in subareas, abbreviated to the nodeless Trefftz method. Local values of heat transfer coefficient on the surface between the heating foil and boiling liquid were calculated on the basis of the third-kind boundary condition. The influence of minichannel orientation on heat transfer coefficient at boiling incipience region values were analyzed. The same tendencies in the results were observed for the two applied methods. The one-dimensional approach seems to be less sensitive to measurement errors. The polynomial smoothing of the results applied in the two-dimensional method can affect the rounding values of coefficient
Heat transfer coefficient determination for flow boiling in vertical and horizontal minichannels
Heat transfer coefficient determination for flow boiling in vertical and horizontal minichannels
The paper presents the results of boiling heat transfer research during FC-72 laminar flow along a minichannel of 1 mm depth, positioned vertically and horizontally, with an enhanced heating surface. One glass pane allows to determine the temperature of the heating wall by liquid crystal thermography. Calculations are aimed at the evaluation of one- and two-dimensional heat transfer approaches to determine the local heat transfer coefficient. In the one-dimensional approach only the direction of the flow in the channel is considered. In the two-dimensional approach the inverse problem in the heating wall and the direct problem in the glass barrier were solved by the finite element method with Trefftz functions as shape functions (FEMT). The developed flow boiling area was studied. Heat transfer coefficient values obtained for the horizontal minichannel were higher than those obtained for the vertical one. When the heat flux supplied to heating wall grows, the share of gas-phase increases leading to the heat transfer coefficient decreases. The same courses of the experiment were observed for the two applied methods, but the results obtained in the one-dimensional approach are considerably higher than in the two-dimensional one. One-dimensional approach seems to be less sensitive to measurement errors
Heat transfer coefficient determination using the FEM with time-dependent Trefftz-type basis functions in subcooled flow boiling in a minichannel
Results concerning flow boiling heat transfer in a vertical minichannel of 1.7 mm depth were shown. The channel was asymmetrically heated by a thin foil. Its surface temperature was recorded continuously in points by thermocouples. Measurements were carried out in 0.01 s intervals. The objective of the numerical calculations was to determine the heat transfer coefficient on the heated foil–fluid contact surface in the minichannel from the Robin boundary condition. Both the foil and fluid temperatures were the result of solving the nonstationary two-dimensional problem in the foil and flowing fluid. The problem was solved by using the FEM combined with Trefftz-type basis functions. The values of the time-dependent local heat transfer coefficient were presented and discussed