This study contributes to basic knowledge on the development of larval digestive enzyme activities of Seriola rivoliana, a carnivorous species that has shown high mortality in larval stage. The study was conducted under laboratory-controlled conditions until larvae reached 30 days after hatching (DAH). The specific activity of amylase and pepsin was analysed by spectrophotometric methods, and lipase, trypsin, chymotrypsin and alkaline phosphatase by fluorometry. The results showed that S. rivoliana larvae had different enzyme patterns depending on their developmental stage, and also when exogenous food was administered (rotifers and Artemia). At hatching (2.98 ± 0.14 mm SL), lipase, alkaline phosphatase, trypsin and chymotrypsin activities were detected, but the last two enzymes showed an activity close to zero. Trypsin, chymotrypsin, lipase and alkaline phosphatase sharply increased their activities after starting the first feeding. Amylase activity was not detected until 5 DAH (3.51 ± 0.18 mm SL) and had a peak on day 15 (4.59 ± 0.39 mm SL); no activity was observed from then on. Pepsin activity was detected approximately at 15 DAH, showing a constant increase onwards. Trypsin had a peak on day 15 and then decreased on the following days. Chymotrypsin had the highest peak at 5 DAH, then a sharp decrease on day seven (3.88 ± 0.11 mm SL), and it increased gradually until day 30 (11.71 ± 1.59 mm SL). Lipase showed the highest activity at 15 DAH and then decreased its value. Finally, alkaline phosphatase showed the highest value at 3 DAH (3.62 ± 0.06 mm SL); then, a severe decrease was observed with activity stability on the following days. In conclusion, S. rivoliana larvae had a similar pattern as that observed in other marine-carnivorous fish larvae, so it could be considered as juvenile at 20 DAH in terms of digestive physiology; based on our results and previous study, the weaning process could start after this age, which would allow establishing a co-feeding protocol using inert diet.

Diabetes mellitus has been a menace to mankind from time immemorial. However, a natural product such as U. chamae P. Beauv (Annonaceae) offers alternative treatment for diabetes mellitus. The study aimed at evaluating antidiabetic activity of the ethanolic root extract of U. chamae in alloxan-induced diabetic rats. Diabetes was induced in Sprague Dawley rats after overnight fast with 150 mg/kg alloxan intraperitoneally. After 72 h, those with plasma glucose levels >200 mg/dl were classified as diabetic. Five diabetic rats in each group were treated daily for 14 days orally with 100, 250, and 400 mg/kg of the extract, glibenclamide (71 µg/kg) and pioglitazone (429 µg/kg), respectively, while another group was untreated. Control received 0.5 ml of Acacia senegal. Effects of extract on glucose, other biochemical, and hematological parameters were evaluated. α-amylase and α-glucosidase inhibitory activities of extract and its fractions were also evaluated. Percentage inhibition and IC50 values were determined. Diabetic control was achieved on the 7th day of the study with 100, 250, and 400 mg/kg of the extract showing glucose reduction of 72.14%, 78.75%, and 87.71%, respectively. The HDL-cholesterol levels of diabetic rats treated with extracts were significantly increased. Extract and its fractions caused α-amylase and α-glucosidase inhibition. Histologically, pancreas of diabetic rats treated with extract showed regenerated islet cells which were not seen in rats treated with glibenclamide and pioglitazone. This study showed that U. chamae has antidiabetic activity which may be through α-amylase and α-glucosidase inhibition and regeneration of pancreatic beta cells. Also, it may reduce the risk of cardiovascular disease by increasing HDL-cholesterol levels.

Because the application of Bisphenol A (BPA) was restricted, many substitutes, such as Bisphenol F (BPF) and Bisphenol S (BPS), were developed as BPA substitutes. Therefore, environmental impacts of BPA and its substitutes on aquatic organisms should be concerned, especially their combined toxicity. In this study, the impacts of BPA, BPF, BPS and their mixture on the feeding behavior, reproduction and physiological function of daphnids were synthetically evaluated, involving the duration and mode of exposure. In short-term exposure tests, feeding rates of D. magna decreased after exposure to BPA, BPF, BPS and their mixture, while the inhibition reversed into stimulation in the recovery period. It may benefit from overcompensation of D. magna. In long-term exposure tests, the inhibition effect on the reproduction and growth of the exposed D. magna was difficult to recover, and only some experimental groups have a certain recovery. In conclusion, environmental risk of BPA, BPF, BPS and their mixture on the behavior of D. magna increased with prolonged exposure time. Moreover, relative activities of trypsin, amylase (AMS), acetylcholinesterase (AChE), carbonic anhydrase (CA), glutathione peroxidase (GPx) and super oxidase dimutase (SOD) of the exposed daphnids decreased in most treatment groups, indicating the disorder of digestive, nervous and antioxidative system of D. magna. Interestingly, inhibition of enzymes activities decreased with the increase of the exposure time, which implied the tolerance may be occurred.

The job demands-resources model (JD-R) has shown an ability to predict worker engagement and exhaustion, yet to our knowledge, research has not been conducted that assesses the JD-R model with physiological indicators of chronic stress and burnout. Using the JD-R model, we assessed if occupational stress and burnout were related to dysregulated cortisol and salivary alpha-amylase awakening responses (sAA-AR). Professional apprentice jockeys comprising of males (n = 14) and females (n = 18) provided morning saliva samples and completed self-report measures relating to job demands and resources, burnout, and perceived mental and physical health. Data was collected at two time points coinciding with naturally occurring 'low' and 'high' stress periods during the racing calendar. The jockeys reported good physical and mental health but had elevated levels of the burnout subtypes cynicism and exhaustion. Regression analyses suggested that those jockeys presenting with reduced professional efficacy in the high stress period produced a 'flattened' sAA-AR indicative of reduced autonomic nervous system (ANS) arousal, which has been associated with burnout. Further, decreases in professional efficacy explained the relationship between increased workplace stress and decreased ANS activity in the high stress period. Our findings suggest that assessments of psychological stress or physiology in isolation are not as useful as looking at both in combination, and extend previous findings on the sAA-AR.

Research or diagnostic conditions may require the storage of salivary samples for long periods before analysis is processed. The aim of this study was to evaluate the stability of canine salivary α-amylase, lysozyme, lactate dehydrogenase (LDH), and total calcium and phosphorus after storage for 1, 3 and 6 months at -20°C. Available saliva samples were 75 immediately after collection (T0) and 46 at 1 month (T1), 31 at 3 months (T3) and 18 at 6 months (T6) of storage, according to the number of aliquots collected from each saliva sample. Compared to T0, LDH declined by 92.3% after 1 month of storage (P<0.001), whereas lysozyme concentration significantly decreased as storage time increased (-29.3%, -43.4% and -59.1% at T1, T3, and T6 respectively, P<0.001). Amylase maintained basically the same concentration for the entire experimental period, whereas total calcium and phosphorus concentration decreased over time (calcium, P<0.001). Assessing the long-term stability of canine salivary analytes stored at -20°C may have important implications in diagnosis and research.

Previous studies have demonstrated that the genetic modification of basal salicylic acid (SA) level changed Arabidopsis plant response to cadmium (Cd) stress, but the mechanisms remain evaluated. In this study, Arabidopsis wild type (WT) and its SA-reducing transgenic line nahG (naphthalene hydroxylase G), SA-accumulating mutant snc1 (suppressor of nonexpressor of PR gene, constitutive 1) were exposed to 50 μM Cd2+ for 48 h or 7 d (just for assessing plant growth). The Cd treatment increased the expression levels of SA biosynthesis-related genes leading to enhanced SA accumulations in plant leaves, which was further confirmed by the expression patterns of SA marker genes. Cadmium accumulation was much higher in the Cd-exposed roots than in leaves, but was not affected by SA levels. Exposure to Cd inhibited plant growth of both aerial parts and roots, to a greater degree in snc1, and a lesser extent in nahG as compared with WT. Although Cd treatment increased plant antioxidative capacity, oxidative damage happened, especially to snc1 plants. Photoinhibition occurred in Cd-stressed plants leading to a decrease in photosynthetic activity, with a greater degree in snc1, while a lesser in nahG, as indicated by the changes of several key photosynthetic parameters. We comprehensively analyzed the expression profiles of photosynthesis-related genes, and observed a positive correlation between Cd tolerance and gene expression levels, wherein the transcription levels of two electron transport-related genes and two amylase-encoding genes were all up-regulated in nahG plants after Cd treatment, implying a significance of the related processes in this genotype against Cd stress.

Previous studies have demonstrated that exercise increases whole body and skeletal muscle insulin sensitivity that is linked with increased GLUT4 at the plasma membrane following insulin stimulation and associated with muscle glycogen depletion. To assess the potential direct association between muscle glycogen and GLUT4, seven untrained, male subjects exercised for 60 min at ~75% VO2 peak, with muscle samples obtained by percutaneous needle biopsy immediately before and after exercise. Exercise reduced muscle glycogen content by ~43%. An ultracentrifugation protocol resulted in a ~2-3-fold enriched glycogen fraction from muscle samples for analysis. Total GLUT4 content was unaltered by exercise and we were unable to detect any GLUT4 in glycogen fractions, either with or without amylase treatment. In skinned muscle fiber segments, there was very little, if any, GLUT4 detected in wash solutions, except following exposure to 1% Triton X-100. Amylase treatment of single fibers did not increase GLUT4 in the wash solution and there were no differences in GLUT4 content between fibers obtained before or after exercise for any of the wash treatments. Our results indicate no direct association between GLUT4 and glycogen in human skeletal muscle, before or after exercise, and suggest that alterations in GLUT4 translocation associated with exercise-induced muscle glycogen depletion are mediated via other mechanisms.