Long-term space missions' effects on the human organism: what we do know and what requires further research.

Space has always fascinated people. Many years have passed since the first spaceflight, and in addition to the enormous technological progress, the level of understanding of human physiology in space is also increasing. The presented paper aims to summarize the recent research findings on the influence of the space environment (microgravity, pressure differences, cosmic radiation, etc.) on the human body systems during short-term and long-term space missions. The review also presents the biggest challenges and problems that must be solved in order to extend safely the time of human stay in space. In the era of increasing engineering capabilities, plans to colonize other planets, and the growing interest in commercial space flights, the most topical issues of modern medicine seems to be understanding the effects of long-term stay in space, and finding solutions to minimize the harmful effects of the space environment on the human body.

Impact of Human Adenovirus 36 on Embryonated Chicken Eggs: Insights into Growth Mechanisms.

Human adenovirus 36 (HAdV-D36) is presently the sole virus identified to be associated with an elevated risk of obesity in both humans and animals. However, its impact on embryonated chicken eggs (ECEs) remains unexplored. This study endeavoured to examine the influence of HAdV-D36 on embryonic development by utilizing embryonated chicken eggs as a dynamic model. To simulate various infection routes, the allantoic cavity and the yolk sac of ECEs were inoculated with HAdV-D36. Subsequently, embryos from both the experimental (inoculated with virus) and control (inoculated with PBS) groups were weighed and subjected to daily histological examination. The daily embryo weights were assessed and compared between groups using the Shapiro-Wilk test. Histopathological changes in tissues were examined and compared between the tested and control groups to ascertain physiological alterations induced by the virus. Our study confirmed a significant increase in the body weight of ECEs. However, this phenomenon was not attributable to adipose tissue development; rather, it was characterized by an augmented number of cells in all observed tissues compared to control subjects. We posit that HAdV-D36 may impact developing organisms through mechanisms other than enhanced adipose tissue development. Specifically, our findings indicate an increased number of cells in all tissues, a phenomenon that occurs through an as-yet-unexplored pathway.

Liver Oxidative Status, Serum Lipids Levels after Bariatric Surgery and High-Fat, High-Sugar Diet in Animal Model of Induced Obesity.

Nutritional status is a major determinant of hepatocyte injuries associated with changed metabolism and oxidative stress. This study aimed to determine the relations between oxidative stress, bariatric surgery, and a high-fat/high-sugar (HFS) diet in a diet-induced obesity rat model. Male rats were maintained on a control diet (CD) or high-fat/high-sugar diet (HFS) inducing obesity. After 8 weeks, the animals underwent SHAM (n = 14) or DJOS (n = 14) surgery and the diet was either changed or unchanged. Eight weeks after the surgeries, the activity of superoxide dismutase isoforms (total SOD, MnSOD, and CuZnSOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), and lutathione S-transferase, as well as the thiol groups (-SH) concentration, total antioxidant capacity (TAC), total oxidative stress (TOS) levels, and malondialdehyde (MDA) concentration liver tissue were assessed. The total cholesterol, triglycerides (TG), and high-density lipoprotein (HDL) concentrations were measured in the serum. The total SOD and GPX activities were higher in the SHAM-operated rats than in the DJOS-operated rats. The MnSOD activity was higher in the HFS/HFS than the CD/CD groups. Higher CuZnSOD, GST, GR activities, -SH, and MDA concentrations in the liver, and the triglyceride and cholesterol concentrations in the serum were observed in the SHAM-operated rats than in the DJOS-operated rats. The CAT activity was significantly higher in the HFS-fed rats. Lower TAC and higher TOS values were observed in the SHAM-operated rats. Unhealthy habits after bariatric surgery may be responsible for treatment failure and establishing an obesity condition with increased oxidative stress.

A 21-Day Individual Rehabilitation Exercise Training Program Changes Irisin, Chemerin, and BDNF Levels in Patients after Hip or Knee Replacement Surgery.

Osteoarthritis (OA) is the most frequent worldwide cause of adult population disabilities. The study evaluated the effects of a 21-day individual rehabilitation exercise training program focused on improving patients' functional capacity. The study analyzed the changes in irisin, chemerin, and BDNF serum levels in 36 OA patients subjected to an individually-adjusted rehabilitation program 90 days after surgical hip or knee replacement. The changes in irisin, chemerin, and BDNF serum levels were measured using enzyme-linked immunosorbent assay (ELISA) kits. A 21-day individual rehabilitation exercise training program significantly increased irisin and BDNF, and decreased chemerin serum levels. The presented study indicates that individually-adjusted exercise training is an important modulator influencing serum levels of anti- and pro-inflammatory factors, leading to positive clinical outcomes in osteoarthritis therapy. Selected factors are considered potential markers of various pathophysiological conditions. The presented study brings new details to the discussion.

The Relationship between the Source of Dietary Animal Fats and Proteins and the Gut Microbiota Condition and Obesity in Humans.

The relationship between gut microbiota and obesity is well documented in humans and animal models. Dietary factors can change the intestinal microbiota composition and influence obesity development. However, knowledge of how diet, metabolism, and intestinal microbiota interact and modulate energy metabolism and obesity development is still limited. Epidemiological studies show a link between consuming dietary proteins and fats from specific sources and obesity. Animal studies confirm that proteins and fats of different origins differ in their ability to prevent or induce obesity. Protein sources, such as meat, dairy products, vegetables, pulses, and seafood, vary in their amino acid composition. In addition, the type and level of other factors, such as fatty acids or persistent organic pollutants, vary depending on the source of dietary protein. All these factors can modulate the intestinal microbiota composition and, thus, may influence obesity development. This review summarizes selected evidence of how proteins and fats of different origins affect energy efficiency, obesity development, and intestinal microbiota, linking protein and fat-dependent changes in the intestinal microbiota with obesity.

Duodenojejunal Omega Switch Surgery Reduces Oxidative Stress Induced by Cafeteria Diet in Sprague-Dawley Rats.

Over-nutrition with cafeteria diet leads to glycemic control failure and subsequent obesity. Bariatric surgery remains the ultimate treatment option, and when complemented with specific dietary protocol, it may mitigate the effects of oxidative stress induced by a cafeteria diet. The study measured antioxidant marker activity: superoxidase dismutase (SOD) and ceruloplasmin (CER), total antioxidant capacity (TAC), and lipid peroxidation marker concentrations: lipofuscin (LS) and malondialdehyde (MDA), in the plasma of 56 Sprague-Dawley rats fed with a cafeteria (HFS) or a control (CD) diet and subjected to duodenojejunal omega switch (DJOS) or control (SHAM) surgery. The diet change after the surgery (CD/HFS or HFS/CD) strongly influenced SOD activity in DJOS- and SHAM-operated rats, but SOD activity was always higher in SHAM-operated rats. Every dietary protocol used in the study increased CER activity, except for the CD/CD combination. Cafeteria diet consumed before or after either of surgeries led to decrease in TAC levels. DJOS and no change in diet reduced MDA levels. DJOS reduced LS levels, but its beneficial effect was deteriorated by selected dietary protocols. The cafeteria diet negatively affected the positive impact of DJOS surgery, but SOD, CER, MDA, and LS were significantly lower in rats that underwent DJOS, suggesting that eight weeks of dietary treatment before and after the surgery did not totally dilapidate the effects of the bariatric treatment.

Digestive enzymes activity in subsequent generations of Cameraria ohridella larvae harvested from horse chestnut trees after treatment with imidacloprid.

In the present study we describe the effect of chloronicotinoid pesticide (imidacloprid) on the digestive enzymes activity of the Cameraria ohridella larvae after lasting 1 year sublethal exposure to imidacloprid pesticide. Caterpillars - L4 stage (fourth instar, hyperphagic tissue-feeding phase) - were collected from chemically protected white horse chestnut trees 1 year after imidacloprid treatment, and compared with caterpillars collected from non-treated trees in a previous study. Enzymes activity of α-amylase, disaccharidases, glycosidases and proteases was assayed. The presence of pesticide in ingested food changed the digestive enzymes profile of caterpillars. The analysis of correlations between different digestive enzymes showed many significant correlations (P<0.05) among glycolytic activities like ß-glucosidase and α-galactosidase activities. Statistically significant correlations for proteolytic activity were found between trypsin and chymotrypsin activity and aminopeptidase activity that occurred only in the 1st generation. PCA distinguished five primary components with eigenvalues higher than 1, from which the first two explain almost 59% of analyzed results. Surprisingly, in the pesticide treated groups significantly higher activities of sucrase and lactase in relation to control were found. In general, glycosidase (α-glucosidase, ß-glucosidase and ß-galactosidase) activities showed a similar pattern of activity in different generations. These results contrast with those obtained with control larvae, where significant differences in activities of α-glucosidase, ß-glucosidase and ß-galactosidase may result from the different quantity and quality food intake by subsequent generations of larvae. No inter-generation differences in total proteolytic activity were observed in treated larvae. The absolute value of total proteolytic activity was higher than that in the control group. The pesticide present in the vascular system of the horse chestnut tree significantly affected some of the digestive enzymes activities and - in consequence - also interrelationships between enzymes, what may affect the food digestion.

Within and between seasonal changes of detoxifying capabilities of Cameraria ohridella (Lepidoptera : Gracillariidae) larvae.

Cameraria ohridella is an invasive leaf miner, a severe pest of horse chestnut trees. Chemical control needs recognition of intrinsic metabolic capability to cope with external stressing factors. Our tasks were to check annual effects of generation, and host tree age on detoxifying abilities of the last larval stage. Activities of CAT, SOD, GSTPX, GST CarE and AChE were assayed in the midgut of larvae from two localities during 3 years and three generations, annually. Activities of GSTPX and GST were high, but CAT and SOD were low in relation to other lepidopteran larvae. In general, the second generation larvae had the highest activity, indicating an effective defence against allelochemicals produced by the host. Effects of host tree age were significant for SOD, GSTPX and CarE activities. Significant annual differences on enzyme profiles of CAT, SOD, CarE and AChE reflected differences of temperature and precipitation between consecutive years.

Alteration of carbohydrates metabolism and midgut glucose absorption in Gromphadorhina portentosa after subchronic exposure to imidacloprid and fenitrothion.

This study was undertaken to test the hypothesis that following exposure to insecticides, changes take place in the metabolism of carbohydrates and absorption in the midgut of insects. The Madagascar hissing cockroach (Gromphadorhina portentosa) was chosen for the experiment as a model organism, due to it being easy to breed and its relatively large alimentary tract, which was important when preparing the microperfusion midgut bioassay. In each group of cockroaches treated with imidacloprid and fenitrothion, absorption of glucose, expressed as the area under the curve (AUC), was elevated compared to the control group. Glucose in the hemolymph of the examined insects was present in a vestigial amount, often below the threshold of determination, so the determinable carbohydrate indices were: hemolymph trehalose concentration and fat body glycogen content. The level of trehalose found in the hemolymph of insects when exposed to fenitrothion, and irrespective of the level of concentration mixed into food, were significantly lower when comparing to the control samples. Imidacloprid acted analogically with one exception at the concentration of 10 mg·kg(-1) dry food where trehalose concentration did not differ from the control values. Coupling with fat body glycogen concentration was less visible and appeared only at the concentrations of 5 and 10 mg imidacloprid·kg(-1) dry food. As described in this study changes in the sugar distribution and midgut glucose absorption indicate that insects cover the increased energy needs induced by insecticides; also at the gastrointestinal tract level. The result indicates that the midgut glucose absorption parameters could be considered as a non-specific biomarker of insecticide toxicity.

Digestive enzymes activity in larvae of Cameraria ohridella (Lepidoptera: Gracillariidae).

This article presents the activity of carbohydratases and proteases in the midgut of Cameraria ohridella larvae--an oligophagous pest whose preferred feeding is horse chestnuts leaves. Optimal media pH of the assayed enzymes were similar to those of other Lepidopterans. Relatively high amylase activity, as well as maltase and sucrase activities, indicates that starch and sucrose are the main digested saccharides. Trehalase activity was similar to that described in other Lepidopterans. Activities of glycosidases were significantly lower than those of disaccharidases what suggests that neither cellulose nor glycosides are important for C. ohridella. Trypsin is the main endoprotease of this pest. Like in other leaf-eaters carboxypeptidase activity was higher than that of aminopeptidase. The activity of the majority of examined enzymes increased in the following successive pest generations, which could be explained by the decreased nutritional value of older leaves. Probably this phenomenon in hydrolases activity in Cameraria is a nonspecific mechanism present at this stage of co-evolution of the horse chestnut and its pest.

Midgut protease activities in monophagous larvae of Apollo butterfly, Parnassius apollo ssp. frankenbergeri.

We assayed the relative activities of midgut proteolytic enzymes in individuals of the fourth (L(4)) and fifth (L(5)) instar of Apollo larvae, inhabiting Pieniny Mts (southern Poland). The comparisons between midgut tissue with glicocalyx (MT) and liquid midgut contents with peritrophic membrane (MC) were made. Optimal media pHs of the assayed proteolytic enzymes in P. apollo midgut samples were similar to those of other lepidopteran species. Endopeptidases, as well as carboxypeptidases, digested effectively in alkaline environment, while aminopeptidases were active in a broad pH range. Trypsin is probably the main endoprotease (correlation with caseinolytic activity in MC of L(5) larvae: r=0.606; p=0.004); however, its activity was low as compared with that in other leaf-eating Lepidoptera. This suggests a minor role of trypsin and chymotrypsin in protein digestion in Apollo larvae, probably due to limited availability of the leaf proteins. Instead, due to very high carboxypeptidase A activity in midgut tissue, the larvae obtain exogenous amino acids either directly or from oligopeptides and glycoproteins. High and significant positive correlations between the enzyme activity and glucosidase as well as galactosidase activities strongly support this opinion.

Midgut glycosidases activities in monophagous larvae of Apollo butterfly, Parnassius apollo ssp. frankenbergeri.

Parnassius apollo (Lepidoptera, Papilionidae) declines on numerous localities all over Europe. Its local subspecies frankenbergeri, inhabiting the Pieniny Mts (southern Poland) and successfully recovered from extinction, is monophagous in larval stage. In natural conditions, it completes development on the orpine Sedum telephium ssp. maximum. Since proper quality and quantity of necessary nutritional compounds of the food plant ensure developmental success, the digestive processes in the insect midgut should reflect adaptation to a specific food source. The paper presents, for the first time, the activity of detected glycolytic enzymes in midgut tissue and liquid gut contents of the L4 and L5 instars of P. apollo larvae. alpha-Amylase plays the main role in utilization of carbohydrates, contrary to cellulase activity. Saccharase seems to be the main disaccharidase, and high activity of beta-glycosidase enables hydrolysis of the plant glycosides. Trehalase activity was unexpectedly low and comparable to those of cellobiase and lactase. alpha-Amylolytic and other glycolytic activities indicate that larvae utilize starch and other carbohydrate compounds as energy sources. Possible use of some plant allelochemicals as energy sources by Apollo larvae is discussed.