Review of Eukaryote Cellular Membrane Lipid Composition, with Special Attention to the Fatty Acids.

Biological membranes, primarily composed of lipids, envelop each living cell. The intricate composition and organization of membrane lipids, including the variety of fatty acids they encompass, serve a dynamic role in sustaining cellular structural integrity and functionality. Typically, modifications in lipid composition coincide with consequential alterations in universally significant signaling pathways. Exploring the various fatty acids, which serve as the foundational building blocks of membrane lipids, provides crucial insights into the underlying mechanisms governing a myriad of cellular processes, such as membrane fluidity, protein trafficking, signal transduction, intercellular communication, and the etiology of certain metabolic disorders. Furthermore, comprehending how alterations in the lipid composition, especially concerning the fatty acid profile, either contribute to or prevent the onset of pathological conditions stands as a compelling area of research. Hence, this review aims to meticulously introduce the intricacies of membrane lipids and their constituent fatty acids in a healthy organism, thereby illuminating their remarkable diversity and profound influence on cellular function. Furthermore, this review aspires to highlight some potential therapeutic targets for various pathological conditions that may be ameliorated through dietary fatty acid supplements. The initial section of this review expounds on the eukaryotic biomembranes and their complex lipids. Subsequent sections provide insights into the synthesis, membrane incorporation, and distribution of fatty acids across various fractions of membrane lipids. The last section highlights the functional significance of membrane-associated fatty acids and their innate capacity to shape the various cellular physiological responses.

Effects of Surface Treatment with Thymol on the Lipid Oxidation Processes, Fatty Acid Profile and Color of Sliced Salami during Refrigerated Storage.

The oxidation of unsaturated fatty acids and the adverse transformation of pigments from meat and spices are the primary causes of chemical degradation in processed meat products. Thymol is found in a variety of plant extracts that have been proven to effectively inhibit or slow down oxidative processes. The objective of our study was to determine whether thymol treatment of the surface of sliced paprika salami could be applied to inhibit lipid oxidation and color change during refrigerated storage. During eight weeks of storage, the malondialdehyde (MDA) levels and the ratios of saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), polyunsaturated fatty acids (PUFAs), and n6/n3 in thymol-treated salami remained unchanged (p ≥ 0.05), whereas in the controls, the MDA levels increased by approximately twelvefold and the ratio of SFAs in the lipid fraction increased (p < 0.001), while the ratio of PUFAs decreased (p < 0.001). The application of thymol prevented decrease in yellowness (b*) of the slices and reduced decreases in redness (a*) and brightness (chroma).

Micro-Encapsulated Microalgae Oil Supplementation Has No Systematic Effect on the Odor of Vanilla Shake-Test of an Electronic Nose.

In this study, we aimed to carry out the efficient fortification of vanilla milkshakes with micro-encapsulated microalgae oil (brand: S17-P100) without distorting the product's odor. A 10-step oil-enrichment protocol was developed using an inclusion rate of 0.2 to 2 w/w%. Fatty acid (FA) profile analysis was performed using methyl esters with the GC-MS technique, and the recovery of docosahexaenoic acid (C22:6 n3, DHA) was robust (r = 0.97, p < 0.001). The enrichment process increased the DHA level to 412 mg/100 g. Based on this finding, a flash-GC-based electronic nose (e-nose) was used to describe the product's odor. Applying principal component (PC) analysis to the acquired sensor data revealed that for the first four PCs, only PC3 (6.5%) showed a difference between the control and the supplemented products. However, no systematic pattern of odor profiles corresponding to the percentages of supplementation was observed within the PC planes. Similarly, when discriminant factor analysis (DFA) was applied, though a classification of the control and supplemented products, we obtained a validation score of 98%, and the classification pattern of the odor profiles did not follow a systematic format. Again, when a more targeted approach such as the partial least square regression (PLSR) was used on the most dominant sensors, a weak relationship (R2 = 0.50) was observed, indicating that there was no linear combination of the qualitative sensors' signals that could accurately describe the supplemented concentration variation. It can therefore be inferred that no detectable off-odor was present as a side effect of the increase in the oil concentration. Some volatile compounds of importance in regard to the odor, such as ethylacetate, ethyl-isobutarate, pentanal and pentyl butanoate, were found in the supplemented product. Although the presence of yeasts and molds was excluded from the product, ethanol was detected in all samples, but with an intensity that was insufficient to cause an off-odor.

Hungarian consensus recommendation on the role of vitamin D in disease prevention and treatment / Magyarországi konszenzusajánlás a D-vitamin szerepérol a betegségek megelozésében és kezelésében

Nine Hungarian medical societies have developed a consensus recommendation on the preferred normal range of vitamin D, the dose of vitamin D supplementation and the method of administration. They summarized the clinical conditions and diseases the development of which may be associated with vitamin D deficiency (VDD). VDD is extremely common in Hungary, especially in late winter. The lower limit of the recommended normal range is 75 nmol/l, although the clinical significance of deficiency is evident mainly at values below 50 nmol/l, but since vitamin D supplementation at the recommended dose is safe, it is worthwhile for everyone to reduce the health risk associated with VDD. The aim of vitamin D supplementation is to prevent deficiency. The recommended normal range is 75­125 nmol/l, above which there is no clear benefit of vitamin D supplementation. To maintain the normal range, a daily intake of 2000 IU in adults is recommended during the UV-B radiation-free period. Vitamin D supplementation is also recommended for children during the same periods and conditions as for adults, but the dose varies with age. In adults, vitamin D3 supplementation at daily, weekly and monthly intervals is equally effective and safe. In severe deficiency, a loading dose is recommended, followed by maintenance supplementation. In addition to the wellknown skeletal, immunological and oncological effects of VDD, more and more data support unfavorable gyneco- logical and obstetric effects. The process of building the consensus has met the requirements of the latest Delphi criteria.

A 65-Day Fumonisin B Exposure at High Dietary Levels Has Negligible Effects on the Testicular and Spermatological Parameters of Adult Rabbit Bucks.

A 65-day study was undertaken to test the effects of two doses (10 and 20 mg/kg) of dietary fumonisin Bs (FB) on the rabbit male reproduction system. Body and testicular weight was not affected by the intoxication, neither the fatty acid composition of the testicular total phospholipids; the testis histological analysis failed to reveal any toxic effect. The FBs increased the testicular concentration and activity of reduced glutathione and glutathione peroxidase and decreased initial phase lipid peroxidation (conjugated dienes and trienes) in a dose dependent manner. Sperm morphology and chromatin condensation were monitored on Feulgen-stained smears. No significant differences were observed between the treatment groups and between sampling time points. The live cell ratio in the sperm (as assessed with flow cytometry) was not different among groups at any of the five sampling timepoints and was also identical within groups. Similarly, the spermatozoa membrane lipid profile was also identical in all three groups after the total intoxication period. In summary, it was demonstrated that FBs in an unrealistic and unjustified high dose still do not exert any drastic harmful effect on the leporine, male reproduction system, meanwhile slightly augmenting testicular antioxidant response.

Examining the Vitamin D Status of Children With Solid Tumors.

Objective: Our aims were to compare the vitamin D status of children with and without cancer and to examine the possible correlation between vitamin D levels in children with cancer before initiating treatment and prognosis.Method: We compared the data of 173 children with cancer with those of 569 children without cancer.Results: We measured a significant difference (p = 1.34E-08) between the vitamin D levels of children with cancer before treatment and children without cancer. There was a significant correlation between the initial vitamin D levels of children with cancer and the prognosis (p = 0.016, odds ratio = 51.33) at 5% significance.Conclusions: The average vitamin D level was 19.76% lower in the population with cancer compared with the average of the control group, and we found a correlation between the lower vitamin D levels in children with cancer and the adverse prognosis. We suggest that supplying vitamin D is reasonable and a prospective study of vitamin D in pediatric patients with cancer is recommended.

Acute and long-term effects of corticosteroid therapy on bone metabolism in patients with kidney diseases.

AIM: The aim of our study was to examine parameters of bone metabolism during pulse and long-term methylprednisolone (MP) treatment in patients with kidney diseases. METHODS: In 13 patients with RPGN, treated with intravenous MP pulses, followed by tapering oral doses, osteocalcin (OC) and ß-CrossLaps (ß-CL) were measured before treatment, after the 3rd pulse, then 1 and 3 months later ("acute study"). In a separate set of analyses serum markers of bone metabolism and bone mineral density (BMD) were studied in 40 patients on maintenance MP therapy ("chronic study"). RESULTS: Immediately after the 3rd MP pulse serum OC decreased to 38 ± 23%, ß-CL increased to 200 ± 121% of the baseline (p = 0.002 for OC and p = 0.003 for ß-CL, respectively), and the OC/ß-CL ratio decreased from 55 ± 35 to 9 ± 7 (p = 0.002). OC remained below and ß-CL above baseline even at 3 months post pulse steroid treatment. Patients in the "chronic study" who were on maintenance oral steroid therapy received 13,844 ± 7,454 mg MP over 53 ± 47 months. BMD at the end of follow-up revealed reduced bone mineral density in 72.5% of the participants. Z-scores both at the hip and at the lumbar spine were significantly correlated with duration of steroid treatment and also with the cumulative steroid dose. CONCLUSION: MP pulse causes immediate, profound suppression of osteoblast function, and significant increase of osteoclast activity, suggesting uncoupling of bone formation and resorption. Prolonged high dose steroid treatment causes significant bone loss in patients with chronic kidney disease. Appropriate systematic follow up of bone metabolism, preventive measures and therapy when needed would be important for the bone health of this patient population.

[Skeletal and extra-skeletal consequences of vitamin D deficiency]. / A D-vitamin-hiány csontrendszeri és csontrendszeren kívüli következményei.

Vitamin D is obtained from cutaneous production when 7-dehydrocholesterol is converted to vitamin D(3) (cholecalciferol) by ultraviolet B radiation or by oral intake of vitamin D. Rickets appeared to have been conquered with vitamin D intake, and many health care professionals thought the major health problems resulting from vitamin D deficiency had been resolved. However, rickets can be considered the tip of the vitamin D deficiency iceberg. In fact, vitamin D deficiency remains common in children and adults. An individual's vitamin D status is best evaluated by measuring the circulating 25-hydroxyvitamin D (25(OH)D3) concentration. There is increasing agreement that the optimal circulating 25(OH)D3 level should be approximately 30 ng/mL or above. Using this definition, it has been estimated that approximately three-quarters of all adults have low levels. In utero and during childhood, vitamin D deficiency can cause growth retardation and skeletal deformities and may increase the risk of hip fracture later in life. Vitamin D deficiency in adults can exacerbate osteopenia and osteoporosis, cause osteomalacia and muscle weakness, and increase the risk of fracture. More recently, associations between low vitamin D status and increased risk for various non-skeletal morbidities have been recognized; whether all of these associations are causally related to low vitamin D status remains to be determined. The discovery that most tissues and cells in the body have vitamin D receptors and that several possess the enzymatic machinery to convert the 25-hydroxyvitamin D3, to the active form, 1,25-dihydroxyvitamin D3, has provided new insights into the function of this vitamin. Of great interest is its role in decreasing the risk of many chronic illnesses, including common cancers, autoimmune diseases, infectious diseases, and cardiovascular disease. In this review I consider the nature of vitamin D deficiency, discuss its role in skeletal and non-skeletal health, and suggest strategies for prevention and treatment.

[Low vitamin D levels among patients at Semmelweis University: retrospective analysis during a one-year period]. / Alacsony D-vitamin-szint a Semmelweis Egyetem betegei körében: a központi laboratóriumban egy év alatt meghatározott D-vitamin-szintek retrospektív értékelése.

UNLABELLED: Even in developed countries the prevalence of subjects with suboptimal vitamin D levels is high. The aim of this retrospective data analysis was to evaluate the prevalence of severe and moderate vitamin D deficiencies (defined as vitamin D levels<15 ng/ml and 15-30 ng/ml, respectively) among patients evaluated at Semmelweis University during a period between April, 2009 and March, 2010. METHODS AND RESULTS: The average vitamin D level of 5808 subjects (3936 women and 1872 men) was 25.5 ± 10.9 ng/ml. The prevalence of moderate and severe vitamin D deficiency in whole population was 72% and 12%, respectively. Higher than normal vitamin D levels were measured in 0.8% of subjects. Female gender, older age and winter season were independent risk factors for vitamin D deficiency. Vitamin D levels were measured repeatedly in 1307 subjects. Interestingly, vitamin D levels measured later were lower compared to those measured at the first time (27.07±13.2 vs. 25.9±9.11 ng/ml, p<0.001). The prevalence of severe and moderate vitamin D deficiency was 8.1 and 71.5 per cent when vitamin D levels were measured at the second time. Of the 110 patients with severe vitamin D deficiency measured repeatedly only 11 patients (10%) presented with normal vitamin D levels at the second time. CONCLUSIONS: These data indicate that severe and moderate vitamin D deficiencies are common in patients evaluated at Semmelweis University. Repeated measurements of vitamin D levels raise the notion that the efficacy of supplementation used for correction of vitamin D levels is not optimal.

20-Hydroxyecdysone increases fiber size in a muscle-specific fashion in rat.

20-Hydroxyecdysone (20E) is an ecdysteroid hormone that regulates moulting in insects. Interestingly, 20E is also found most abundantly in plant species and has anabolic effects in vertebrates, i.e. increasing muscle size without androgen influence. The effect of 20E on slow and fast fiber types of skeletal muscle has not been reported yet. Here we present that 20E affects the size (cross-sectional area, CSA) of the different fiber types in a muscle-specific manner. The effect on fiber size was modified by the distance from the site of the treatment and the presence of a regenerating soleus muscle in the animal. Besides the fiber size, 20E also increased the myonuclear number in the fibers of normal and regenerating muscles, suggesting the activation of satellite cells. According to our results 20E may provide an alternative for substitution of anabolic-androgenic steroids in therapeutic treatments against muscle atrophy.

Effect of inhibition of neuronal nitric oxide synthase and L-arginine supplementation on renal ischaemia-reperfusion injury and the renal nitric oxide system.

The role of nitric oxide synthases (NOS) and the nitric oxide (NO) substrate l-arginine in renal ischaemia-reperfusion (I/R) has been studied extensively. However, the results reported are often controversial. In the present study, we examined the effects of the neuronal (n) NOS inhibitor 7-nitroindazole (7-NI) and L-arginine administration on renal I/R injury and the renal NO system in rats. Following 7 days pretreatment with 7-NI (50 mg/kg per day), L-arginine (2 g/kg per day) or vehicle (dimethylsulphoxide : sesame oil, 1 : 9), the left renal vascular pedicles were clamped for 50 min in male Sprague-Dawley rats and kidneys were removed 24 h after reperfusion (n = 7/group). Neither 7-NI nor L-arginine had any effect on parameters of renal function, the grade of tissue injury or the number of terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick end-labelling (TUNEL)-positive tubular cells compared with vehicle-treated rats. 7-Nitroindazole decreased nNOS mRNA expression and inducible (i) NOS protein levels, but had no effect on endothelial NOS expression. L-arginine supplementation increased mRNA expression of all NOS isoforms, but only increased protein expression of iNOS. The results of the present study demonstrate that selective inhibition of nNOS has no effect on renal injury, indicating that nNOS does not play a central role in the pathophysiology of renal I/R. In addition, although L-arginine has no effect on renal I/R injury in the model used in the present study, its administration increases the mRNA expression of NOS isoforms.