Characterization of Gastric Tissue-Resident T Cells in Autoimmune and Helicobacter pylori-Associated Gastritis

Data regarding the in-depth surface marker profiles of gastric tissue-resident lymphocytes in autoimmune and Helicobacter pylori-associated gastritis are lacking. In this study, we investigated potential differences in lymphocyte composition between these profiles. We enrolled patients with autoimmune (n = 14), active (current infection of H. pylori in the stomach; n = 10), and inactive gastritis (post-eradication of H. pylori; n = 20). Lymphocytes were isolated from the greater curvature of the stomach and lesser curvature of the body and analyzed using flow cytometry. The CD8⁺/CD3⁺ and CD4⁺/CD3⁺ ratios differed between the samples. Body CD4⁺/antrum CD4⁺, which is calculated by dividing the CD4⁺/CD3⁺ ratio in the body by that in the antrum, was significantly higher in autoimmune gastritis (3.54 ± 3.13) than in active (1.47 ± 0.41) and inactive gastritis (1.42 ± 0.77). Antrum CD8⁺/CD4⁺ in autoimmune gastritis (7.86 ± 7.23) was also higher than that in active (1.49 ± 0.58) and inactive gastritis (2.84 ± 2.17). The area under the receiver operating characteristic curve of antrum CD8⁺/CD4⁺ was 0.842, and the corresponding optimal cutoff point was 4.0, with a sensitivity of 71.4% and a specificity of 93.3%. We propose that an antrum CD8⁺/CD4⁺ ratio > 4.0 is a potential diagnostic marker for autoimmune gastritis.     

Effect of Microvilli on Lateral Diffusion Measurements Made by the Fluorescence Photobleaching Recovery Technique

To consider the effect of surface microvilli on measurements of lateral diffusion by fluorescence photobleaching recovery, we have measured the diffusion of the lipid probe 3,3′-dihexadecyl indocarbocyanine iodide on the villated main body and unvillated budding polar body of unfertilized mouse eggs. On the main body we found D = (6.41 ± 0.62) × 10^-9 cm²/s with (77.0 ± 2.1)% recovery, and on the budding polar body we found D = (7.05 ± 0.75) × 10^-9 cm²/s with (84.7 ± 1.3)% recovery. We thus find only slight differences in diffusion in the two regions.     

Clinical Significance of the Edema Index in Incident Peritoneal Dialysis Patients

Background

Proper monitoring for volume overload is important to improve prognosis in peritoneal dialysis (PD) patients. The association between volume status and residual renal function (RRF) remains an unresolved issue. The aim of the present study was to evaluate the association between the edema index and survival or RRF in incident PD patients.

Patients and Methods

We identified all adults who underwent PD. The edema index was defined as the ratio of extracellular fluid to total body fluid. Participants with available data regarding survivorship or non-survivorship during the first year after PD initiation were included in the area under the receiver operating characteristic curve analysis. The cutoff value of the edema index for 1-year mortality was >0.371 in men and >0.372 in women. Participants were divided into two groups according to the cutoff value of their baseline edema indices: High (>cutoff value) and Low (≤cutoff value). Survivors during the first year after PD initiation were divided into two groups according to the initial and 1-year edema index: Non-improvement (maintenance of criteria in the initial Low group during the year) and Other (all participants except those in the Non-improvement group).

Results

In total, 631 patients were enrolled in the present study. The cutoff value of the edema index for 1-year mortality was >0.371 in men and >0.372 in women. The respective mean initial RRF values (mL·min^-1·1.73 m^-2) in the Low and High groups, respectively, were 4.88 ± 4.09 and 4.21 ± 3.28 in men (P = 0.108), and 3.19 ± 2.57 and 2.98 ± 2.70 in women (P = 0.531). There were no significant differences between groups in either sex. The respective mean RRF values at 1 year after PD initiation in the Low and High groups, respectively, were 3.56 ± 4.35 and 2.73 ± 2.53 in men, and 2.80 ± 2.36 and 1.85 ± 1.51 in women. RRF at 1 year after PD initiation was higher in the Low group than in the High group (men: P = 0.027; women: P = 0.001). In men, the cumulative 5-year survival rates were 78.7% and 46.2% in the Low and High groups, respectively, whereas in women, rates were 77.2% and 58.8% in the Low and High groups, respectively. For survivors during the first year after PD initiation, the Non-improvement group was associated with a poor survival rate compared with the Other group for both sexes.

Conclusion

A high edema index was associated with mortality in incident PD patients at baseline and follow-up. The edema index may be used as a new marker for predicting mortality in PD patients.     

Dynamics of G6PD activity in patients receiving weekly primaquine for therapy of Plasmodium vivax malaria

BackgroundAcute Plasmodium vivax malaria is associated with haemolysis, bone marrow suppression, reticulocytopenia, and post-treatment reticulocytosis leading to haemoglobin recovery. Little is known how malaria affects glucose-6-phosphate dehydrogenase (G6PD) activity and whether changes in activity when patients present may lead qualitative tests, like the fluorescent spot test (FST), to misdiagnose G6PD deficient (G6PDd) patients as G6PD normal (G6PDn). Giving primaquine or tafenoquine to such patients could result in severe haemolysis.MethodsWe investigated the G6PD genotype, G6PD enzyme activity over time and the baseline FST phenotype in Cambodians with acute P. vivax malaria treated with 3-day dihydroartemisinin piperaquine and weekly primaquine, 0·75 mg/kg x8 doses.ResultsOf 75 recruited patients (males 63), aged 5–63 years (median 24), 15 were G6PDd males (14 Viangchan, 1 Canton), 3 were G6PD Viangchan heterozygous females, and 57 were G6PDn; 6 patients had α/β-thalassaemia and 26 had HbE.Median (range) Day0 G6PD activities were 0·85 U/g Hb (0·10–1·36) and 11·4 U/g Hb (6·67–16·78) in G6PDd and G6PDn patients, respectively, rising significantly to 1·45 (0·36–5·54, p<0.01) and 12·0 (8·1–17·4, p = 0.04) U/g Hb on Day7, then falling to ~Day0 values by Day56. Day0 G6PD activity did not correlate (p = 0.28) with the Day0 reticulocyte counts but both correlated over time. The FST diagnosed correctly 17/18 G6PDd patients, misclassifying one heterozygous female as G6PDn.ConclusionsIn Cambodia, acute P. vivax malaria did not elevate G6PD activities in our small sample of G6PDd patients to levels that would result in a false normal qualitative test. Low G6PDd enzyme activity at disease presentation increases upon parasite clearance, parallel to reticulocytosis. More work is needed in G6PDd heterozygous females to ascertain the effect of P. vivax on their G6PD activities.Trial registrationThe trial was registered (ACTRN12613000003774) with the Australia New Zealand Clinical trials (https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=363399&isReview=true).     

A Genetic Test of Sexual Size Dimorphism in Pre-Emergent Chinook Salmon

Sex differences in early development may play an important role in the expression of sexual size dimorphism at the adult stage. To test whether sexual size dimorphism is present in pre-emergent chinook salmon (Oncorhynchus tshawytscha), alevins were reared at two temperatures (10 °C and 15 °C) and sexed using the OtY1 marker on the Y-chromosome. Linear mixed models were used to test for sex differences in alevin size within families while controlling for the random effects of sire and dam nested within sire. Males and females did not differ in weight at 10 °C but males were heavier than females at 15 °C. Sex accounted for 2% of the within-family variance in weight. In addition, at 15°C, the relationship between weight and sex was greater in families with larger eggs. Whereas male-biased sexual size dimorphism was present at the juvenile stage, female-biased sexual size dimorphism was present at sexual maturity. Males were also younger than females at sexual maturity. A head start on growth by males may underlie their earlier maturation at a smaller size, thus leading to female-biased SSD at the adult stage.     

Affinity for phosphatidylinositol 4,5-bisphosphate determines muscarinic agonist sensitivity of Kv7 K+ channels

Kv7 K⁺-channel subunits differ in their apparent affinity for PIP₂ and are differentially expressed in nerve, muscle, and epithelia in accord with their physiological roles in those tissues. To investigate how PIP₂ affinity affects the response to physiological stimuli such as receptor stimulation, we exposed homomeric and heteromeric Kv7.2, 7.3, and 7.4 channels to a range of concentrations of the muscarinic receptor agonist oxotremorine-M (oxo-M) in a heterologous expression system. Activation of M₁ receptors by oxo-M leads to PIP₂ depletion through G_q and phospholipase C (PLC). Chinese hamster ovary cells were transiently transfected with Kv7 subunits and M₁ receptors and studied under perforated-patch voltage clamp. For Kv7.2/7.3 heteromers, the EC₅₀ for current suppression was 0.44 ± 0.08 µM, and the maximal inhibition (Inhib_max) was 74 ± 3% (n = 5–7). When tonic PIP₂ abundance was increased by overexpression of PIP 5-kinase, the EC₅₀ was shifted threefold to the right (1.2 ± 0.1 µM), but without a significant change in Inhib_max (73 ± 4%, n = 5). To investigate the muscarinic sensitivity of Kv7.3 homomers, we used the A315T pore mutant (Kv7.3^T) that increases whole-cell currents by 30-fold without any change in apparent PIP₂ affinity. Kv7.3^T currents had a slightly right-shifted EC₅₀ as compared with Kv7.2/7.3 heteromers (1.0 ± 0.8 µM) and a strongly reduced Inhib_max (39 ± 3%). In contrast, the dose–response curve of homomeric Kv7.4 channels was shifted considerably to the left (66 ± 8 nM), and Inhib_max was slightly increased (81 ± 6%, n = 3–4). We then studied several Kv7.2 mutants with altered apparent affinities for PIP₂ by coexpressing them with Kv7.3^T subunits to boost current amplitudes. For the lower affinity (Kv7.2 (R463Q)/Kv7.3^T) or higher affinity (Kv7.2 (R463E)/Kv7.3^T) channels, the EC₅₀ and Inhib_max were similar to Kv7.4 or Kv7.3^T homomers (0.12 ± 0.08 µM and 79 ± 6% [n = 3–4] and 0.58 ± 0.07 µM and 27 ± 3% [n = 3–4], respectively). The very low-affinity Kv7.2 (R452E, R459E, and R461E) triple mutant was also coexpressed with Kv7.3^T. The resulting heteromer displayed a very low EC₅₀ for inhibition (32 ± 8 nM) and a slightly increased Inhib_max (83 ± 3%, n = 3–4). We then constructed a cellular model that incorporates PLC activation by oxo-M, PIP₂ hydrolysis, PIP₂ binding to Kv7-channel subunits, and K⁺ current through Kv7 tetramers. We were able to fully reproduce our data and extract a consistent set of PIP₂ affinities.     

Unpredictable Feeding Impairs Glucose Tolerance in Growing Lambs

Irregular eating is associated with insulin resistance and metabolic disease in adults but may affect young, growing children differently. We investigated the metabolic effects of unpredictable feeding in female juvenile lambs randomly assigned to receive, for six weeks, maintenance feed given twice daily in equal portions (Control Group, C; n = 24) or the same weekly feed amount in aliquots of variable size at unpredictable times (Unpredictable Group, U; n = 21). Intravenous glucose tolerance tests (IVGTT), insulin tolerance tests (ITT), and measurement of diurnal plasma cortisol concentrations were performed pre and post the dietary intervention. Groups were compared using t test and RM ANOVA. Weight gain was similar in both groups (C 18±2%; U 16±2% of initial body weight). Glucose area under the curve (AUC) was unchanged in C (AUC pre 818±34, post 801±33 mmol.min.l⁻¹), but increased by 20% in U (pre 830±25, post 1010±19 mmol.min.l⁻¹; p<0.0001), with an inadequate insulin response to glucose load (log(AUC insulin first 40 minutes) post intervention C 1.49±0.04 vs U 1.36±0.04 ng.min.ml⁻¹; p = 0.03). Insulin tolerance and diurnal variation of plasma cortisol concentrations were not different between groups. Unpredictable feeding impairs insulin response to glucose in growing lambs despite high quality food and normal weight gain. Irregular eating warrants investigation as a potentially remediable risk factor for disordered glucose metabolism.     

Water transport in the midrib tissue of maize leaves : direct measurement of the propagation of changes in cell turgor across a plant tissue

Water movement across plant tissues occurs along two paths: from cell-to-cell and in the apoplasm. We examined the contribution of these two paths to the kinetics of water transport across the parenchymatous midrib tissue of the maize (Zea mays L.) leaf. Water relations parameters (hydraulic conductivity, Lp; cell elastic coefficient, ε; half-time of water exchange for individual cells, T_½) of individual parenchyma cells determined with the pressure probe varied in different regions of the midrib. In the adaxial region, Lp = (0.3 ± 0.3)·10⁻⁵ centimeters per second per bar, ε = 103 ± 72 bar, and T_½ = 7.9 ± 4.8 seconds (n = seven cells); whereas, in the abaxial region, Lp = (2.5 ± 0.9)·10⁻⁵ centimeters per second per bar, ε = 41 ± 9 bar, and T_½ = 1.3 ± 0.5 seconds (n = 7). This zonal variation in Lp, ε, and T_½ indicates that tissue inhomogeneities exist for these parameters and could have an effect on the kinetics of water transport across the tissue.

The diffusivity of the tissue to water (D_t) obtained from the sorption kinetics of rehydrating tissue was D_t = (1.1 ± 0.4)·10⁻⁶ square centimeters per second (n = 6). The diffusivity of the cell-to-cell path (D_c) calculated from pressure probe data ranged from D_c = 0.4·10⁻⁶ square centimeters per second in the adaxial region to D_c = 6.1·10⁻⁶ square centimeters per second in the abaxial region of the tissue. D_t D_c suggests substantial cell-to-cell transport of water occurred during rehydration. However, the tissue diffusivity calculated from the kinetics of pressure-propagation across the tissue (D_t′) was D_t′ = (33.1 ± 8.0)·10⁻⁶ square centimeters per second (n = 8) and more than 1 order of magnitude larger than D_t. Also, the hydraulic conductance of the midrib tissue (Lp_m per square centimeter of surface) estimated from pressure-induced flows across several parenchyma cell layers was Lp_m = (8.9 ± 5.6)·10⁻⁵ centimeters per second per bar (n = 5) and much larger than Lp.

These results indicate that the preferential path for water transport across the midrib tissue depends on the nature of the driving forces present within the tissue. Under osmotic conditions, the cell-to-cell path dominates, whereas under hydrostatic conditions water moves primarily in the apoplasm.

     

Direct Determination of Carbon and Nitrogen Contents of Natural Bacterial Assemblages in Marine Environments

In order to better estimate bacterial biomass in marine environments, we developed a novel technique for direct measurement of carbon and nitrogen contents of natural bacterial assemblages. Bacterial cells were separated from phytoplankton and detritus with glass fiber and membrane filters (pore size, 0.8 μm) and then concentrated by tangential flow filtration. The concentrate was used for the determination of amounts of organic carbon and nitrogen by a high-temperature catalytic oxidation method, and after it was stained with 4′,6-diamidino-2-phenylindole, cell abundance was determined by epifluorescence microscopy. We found that the average contents of carbon and nitrogen for oceanic bacterial assemblages were 12.4 ± 6.3 and 2.1 ± 1.1 fg cell⁻¹ (mean ± standard deviation; n = 6), respectively. Corresponding values for coastal bacterial assemblages were 30.2 ± 12.3 fg of C cell⁻¹ and 5.8 ± 1.5 fg of N cell⁻¹ (n = 5), significantly higher than those for oceanic bacteria (two-tailed Student’s t test; P < 0.03). There was no significant difference (P > 0.2) in the bacterial C:N ratio (atom atom⁻¹) between oceanic (6.8 ± 1.2) and coastal (5.9 ± 1.1) assemblages. Our estimates support the previous proposition that bacteria contribute substantially to total biomass in marine environments, but they also suggest that the use of a single conversion factor for diverse marine environments can lead to large errors in assessing the role of bacteria in food webs and biogeochemical cycles. The use of a factor, 20 fg of C cell⁻¹, which has been widely adopted in recent studies may result in the overestimation (by as much as 330%) of bacterial biomass in open oceans and in the underestimation (by as much as 40%) of bacterial biomass in coastal environments.     

Extreme home range sizes among Eurasian lynx at the northern edge of their biogeographic range

Eurasian lynx (Lynx lynx) have a wide distribution across Eurasia. The northern edge of this distribution is in Norway, where they reach up to 72 degrees north. We conducted a study of lynx space use in this region from 2007 to 2013 using GPS telemetry. The home range sizes averaged 2,606 (± 438 SE) km² for males (n = 9 ranges) and 1,456 (± 179 SE) km² for females (n = 24 ranges). These are the largest home ranges reported for any large felid, and indeed are only matched by polar bears, arctic living wolves, and grizzly bears among all the Carnivora. The habitat occupied was almost entirely treeless alpine tundra, with home ranges only containing from 20% to 25% of forest. These data have clear implications for the spatial planning of lynx management in the far north as the current management zones are located in unsuitable habitats and are not large enough to encompass individual lynx movements.     

Aerial photogrammetry and tag-derived tissue density reveal patterns of lipid-store body condition of humpback whales on their feeding grounds

Monitoring the body condition of free-ranging marine mammals at different life-history stages is essential to understand their ecology as they must accumulate sufficient energy reserves for survival and reproduction. However, assessing body condition in free-ranging marine mammals is challenging. We cross-validated two independent approaches to estimate the body condition of humpback whales (Megaptera novaeangliae) at two feeding grounds in Canada and Norway: animal-borne tags (n = 59) and aerial photogrammetry (n = 55). Whales that had a large length-standardized projected area in overhead images (i.e. whales looked fatter) had lower estimated tissue body density (TBD) (greater lipid stores) from tag data. Linking both measurements in a Bayesian hierarchical model to estimate the true underlying (hidden) tissue body density (uTBD), we found uTBD was lower (−3.5 kg m⁻³) in pregnant females compared to adult males and resting females, while in lactating females it was higher (+6.0 kg m⁻³). Whales were more negatively buoyant (+5.0 kg m⁻³) in Norway than Canada during the early feeding season, possibly owing to a longer migration from breeding areas. While uTBD decreased over the feeding season across life-history traits, whale tissues remained negatively buoyant (1035.3 ± 3.8 kg m⁻³) in the late feeding season. This study adds confidence to the effectiveness of these independent methods to estimate the body condition of free-ranging whales.     

Correlation of Perfusion MRI and 18F-FDG PET Imaging Biomarkers for Monitoring Regorafenib Therapy in Experimental Colon Carcinomas with Immunohistochemical Validation

ObjectivesTo investigate a multimodal, multiparametric perfusion MRI / ¹⁸F-fluoro-deoxyglucose-(¹⁸F-FDG)-PET imaging protocol for monitoring regorafenib therapy effects on experimental colorectal adenocarcinomas in rats with immunohistochemical validation.ResultsRegorafenib significantly (p<0.01) suppressed PF (81.1±7.5 to 50.6±16.0 mL/100mL/min), PV (12.1±3.6 to 7.5±1.6%) and PS (13.6±3.2 to 7.9±2.3 mL/100mL/min) as well as TTB (3.4±0.6 to 1.9±1.1) between baseline and day 7. Immunohistochemistry revealed significantly (p<0.03) lower tumor microvascular density (CD-31, 7.0±2.4 vs. 16.1±5.9) and tumor cell proliferation (Ki-67, 434.0 ± 62.9 vs. 663.0 ± 98.3) in the therapy group. Perfusion MRI parameters ΔPF, ΔPV and ΔPS showed strong and significant (r = 0.67-0.78; p<0.01) correlations to the PET parameter ΔTTB and significant correlations (r = 0.57-0.67; p<0.03) to immunohistochemical Ki-67 as well as to CD-31-stainings (r = 0.49-0.55; p<0.05).ConclusionsA multimodal, multiparametric perfusion MRI/PET imaging protocol allowed for non-invasive monitoring of regorafenib therapy effects on experimental colorectal adenocarcinomas in vivo with significant correlations between perfusion MRI parameters and ¹⁸F-FDG-PET validated by immunohistochemistry.     

Photobacterium angustum and Photobacterium kishitanii,Psychrotrophic High-Level Histamine-Producing Bacteria Indigenous to Tuna

Scombrotoxin fish poisoning (SFP) remains the main contributor of fish poisoning incidents in the United States, despite efforts to control its spread. Psychrotrophic histamine-producing bacteria (HPB) indigenous to scombrotoxin-forming fish may contribute to the incidence of SFP. We examined the gills, skin, and anal vents of yellowfin (n = 3), skipjack (n = 1), and albacore (n = 6) tuna for the presence of indigenous HPB. Thirteen HPB strains were isolated from the anal vent samples from albacore (n = 3) and yellowfin (n = 2) tuna. Four of these isolates were identified as Photobacterium kishitanii and nine isolates as Photobacterium angustum; these isolates produced 560 to 603 and 1,582 to 2,338 ppm histamine in marine broth containing 1% histidine (25°C for 48 h), respectively. The optimum growth temperatures and salt concentrations were 26 to 27°C and 1% salt for P. kishitanii and 30 to 32°C and 2% salt for P. angustum in Luria 70% seawater (LSW-70). The optimum activity of the HDC enzyme was at 15 to 30°C for both species. At 5°C, P. kishitanii and P. angustum had growth rates of 0.1 and 0.2 h⁻¹, respectively, and the activities of histidine decarboxylase (HDC) enzymes were 71% and 63%, respectively. These results show that indigenous HPB in tuna are capable of growing at elevated and refrigeration temperatures. These findings demonstrate the need to examine the relationships between the rate of histamine production at refrigeration temperatures, seafood shelf life, and regulatory limits.     

Harmonic Analysis of the Fluorescence Response of Bimane Adducts of Colicin E1 at Helices 6, 7, and 10

The pre-channel state of helices 6, 7, and 10 (Val⁴⁴⁷–Gly⁴⁷⁵ and Ile⁵⁰⁸–Ile⁵²²) of colicin E1 was investigated by a site-directed fluorescence labeling technique. A total of 44 cysteine variants were purified and covalently labeled with monobromobimane fluorescent probe. A variety of fluorescence properties of the bimane fluorophore were measured for both the soluble and membrane-bound states of the channel peptide, including the fluorescence emission maximum, fluorescence anisotropy, and membrane bilayer penetration depth. Using site-directed fluorescence labeling combined with our novel helical periodicity analysis method, the data revealed that helices 6, 7, and 10 are separate amphipathic α-helices with a calculated periodicity of T = 3.34 ± 0.08 for helix 6, T = 3.56 ± 0.03 for helix 7, and T = 2.99 ± 0.12 for helix 10 in the soluble state. In the membrane-bound state, the helical periodicity was determined to be T = 3.00 ± 0.15 for helix 6, T = 3.68 ± 0.03 for helix 7, and T = 3.47 ± 0.04 for helix 10. Dual fluorescence quencher analysis showed that both helices 6 and 7 adopt a tilted topology that correlates well with the analysis based on the fluorescence anisotropy profile. These data provide further support for the umbrella model of the colicin E1 channel domain.     

Fatty acid and very low density lipoprotein metabolism in obese African American and Caucasian women with type 2 diabetes

Type 2 diabetes mellitus (T2DM) is associated with increased plasma triglyceride (TG) concentrations, but African Americans (AA) have lower plasma TG than Caucasians (CC). We evaluated the hypothesis that obese AA women have lower plasma TG than obese CC women do because of differences in lipid kinetics. Eleven AA and 11 CC obese women with T2DM, matched on body mass index (BMI) (AA = 37 ± 1, CC = 37 ± 1 kg/m²), age, duration of diabetes, percentage body fat, and insulin sensitivity (S_I, determined by an intravenous glucose tolerance test), were studied. Plasma TG concentration (AA = 1.14 ± 0.11, CC = 1.88 ± 0.18 mmol/l), FFA rate of appearance (R_a) into plasma (AA = 419 ± 27, CC = 503 ± 31 µmol·min⁻¹), and total VLDL-TG secretion rate (AA = 18 ± 2, CC = 29 ± 4 µmol·min⁻¹) were lower in AA than CC women (all P < 0.05). In contrast, plasma total apolipoprotein (apo)B-100 concentration (AA = 1,542 ± 179, CC = 1,620 ± 118 nmol/l) and VLDL-apoB-100 secretion rate (AA = 1.3 ± 0.1, CC = 1.3 ± 0.1 nmol·min⁻¹) were similar in both groups, so the molar ratio of VLDL-TG secretion rate to VLDL-apoB-100 secretion rate was lower in AA women than in CC women. VLDL-TG concentration was lower in AA women due to lower total VLDL-TG secretion rate. However, the VLDL-apoB-100 secretion rate was the same in both groups, demonstrating that AA women secrete smaller VLDL particles containing less TG than do CC women.     

A comparison of two commercially available ELISA methods for the quantification of human plasma heat shock protein 70 during rest and exercise stress

This study compared resting and exercise heat/hypoxic stress-induced levels of plasma extracellular heat shock protein 70 (eHSP70) in humans using two commercially available enzyme-linked immunosorbent assay (ELIS)A kits. EDTA plasma samples were collected from 21 males during two separate investigations. Participants in part A completed a 60-min treadmill run in the heat (HOT70; 33.0 ± 0.1 °C, 28.7 ± 0.8 %, n = 6) at 70 % V̇O_2max. Participants in part B completed 60 min of cycling exercise at 50 % V̇O_2max in either hot (HOT50; 40.5 °C, 25.4 relative humidity (RH)%, n = 7) or hypoxic (HYP50; fraction of inspired oxygen (F_IO₂) = 0.14, 21 °C, 35 % RH, n = 8) conditions. Samples were collected prior to and immediately upon termination of exercise and analysed for eHSP70 using EKS-715 high-sensitivity HSP70 ELISA and new ENZ-KIT-101 Amp’d™ HSP70 high-sensitivity ELISA. ENZ-KIT was superior in detecting resting eHSP70 (1.54 ± 3.27 ng·mL⁻¹; range 0.08 to 14.01 ng·mL⁻¹), with concentrations obtained from 100 % of samples compared to 19 % with EKS-715 assay. The ENZ-KIT requires optimisation prior to running samples in order to ensure participants fall within the standard curve, a step not required with EKS-715. Using ENZ-KIT, a 1:4 dilution allowed for quantification of resting HSP70 in 26/32 samples, with a 1:8 (n = 3) and 1:16 (n = 3) dilution required to determine the remaining samples. After exercise, eHSP70 was detected in 6/21 and 21/21 samples using EKS-715 and ENZ-KIT, respectively. eHSP70 was increased from rest after HOT70 (p < 0.05), but not HOT50 (p > 0.05) or HYP50 (p > 0.05) when analysed using ENZ-KIT. It is recommended that future studies requiring the precise determination of resting plasma eHSP70 use the ENZ-KIT (i.e. HSP70 Amp’d® ELISA) instead of the EKS-715 assay, despite additional assay development time and cost required.     

Motor Performance Assessment in Parkinson’s Disease: Association between Objective In-Clinic,Objective In-Home,and Subjective/Semi-Objective Measures

Advances in wearable technology allow for the objective assessment of motor performance in both in-home and in-clinic environments and were used to explore motor impairments in Parkinson’s disease (PD). The aims of this study were to: 1) assess differences between in-clinic and in-home gait speed, and sit-to-stand and stand-to-sit duration in PD patients (in comparison with healthy controls); and 2) determine the objective physical activity measures, including gait, postural balance, instrumented Timed-up-and-go (iTUG), and in-home spontaneous physical activity (SPA), with the highest correlation with subjective/semi-objective measures, including health survey, fall history (fallers vs. non-fallers), fear of falling, pain, Unified Parkinson''s Disease Rating Scale, and PD stage (Hoehn and Yahr). Objective assessments of motor performance were made by measuring physical activities in the same sample of PD patients (n = 15, Age: 71.2±6.3 years) and age-matched healthy controls (n = 35, Age: 71.9±3.8 years). The association between in-clinic and in-home parameters, and between objective parameters and subjective/semi-objective evaluations in the PD group was assessed using linear regression-analysis of variance models and reported as Pearson correlations (R). Both in-home SPA and in-clinic assessments demonstrated strong discriminatory power in detecting impaired motor function in PD. However, mean effect size (0.94±0.37) for in-home measures was smaller compared to in-clinic assessments (1.30±0.34) for parameters that were significantly different between PD and healthy groups. No significant correlation was observed between identical in-clinic and in-home parameters in the PD group (R = 0.10–0.25; p>0.40), while the healthy showed stronger correlation in gait speed, sit-to-stand duration, and stand-to-sit duration (R = 0.36–0.56; p<0.03). This suggests a better correlation between supervised and unsupervised motor function assessments in healthy controls compared to PD group. In the PD group, parameters related to velocity and range-of-motion of lower extremity within gait assessment (R = 0.58–0.84), and turning duration and velocity within iTUG test (R = 0.62–0.77) demonstrated strong correlations with PD stage (p<0.01).     

Single-trait and antagonistic index selection for litter size and body weight in mice

Individual selection based on female performance only was conducted in four lines of mice: L⁺ for increased litter size, W⁺ for increased 6-week body weight, L^-W⁺ for a selection index aimed at decreasing litter size and increasing 6-week body weight and L⁺W^- for a selection index aimed at increasing litter size and decreasing 6-week body weight. A fifth line (K) served as an unselected control. All litters were standardized to eight mice at one day of age. Expected heritability was based on twice the regression of offspring on dam (h²_d), which contains additive genetic variance due to direct (σ²_Ao) and maternal (σ²_Am) effects and their covariance (σ_AoAm). Responses and correlated responses were measured either deviated (method 1) or not deviated (method 2) from the control line. Realized heritabilities (h²_R) for litter size were 0.19 ± 0.04 (1) and 0.16 ± 0.03 (2), which were similar to h ²_d of 0.17 ± 0.04. The h² _R for 6-week body weight of 0.55 ± 0.07 (1) and 0.44 ± 0.07 (2) agreed with h²_d of 0.42 ± 0.02. Realized genetic correlations (r*_GR) between litter size and 6-week body weight calculated from the double-selection experiment were 0.52 ± 0.10 (1) and 0.52 ± 0.13 (2), which were not significantly different from the base population estimate of r* _Gd = 0.63 ± 0.14. Divergence (L^-W ⁺ minus L⁺W^-) in the antagonistic index selection lines was 0.21 ± 0.01 index units (I = 0.305 P_W - 0.436 P_L, where P _W and P_L are the phenotypic values for 6-week body weight and litter size, respectively.). The h² _R of index units of 0.14 ± 0.02 calculated from divergence agreed with h²_d of 0.14 ± 0.04. Divergences in litter size (-0.19 ± 0.07) and 6-week body weight (0.46 ± 0.10) were in the expected direction. Antagonistic index selection yielded about one-half the expected divergence in litter size, while divergence in 6-week body weight was only slightly less than expected. Realized genetic correlations indicated that litter size, 6-week body weight and index units each showed positive pleiotropy with 3-week body weight, postweaning gain and weight at vaginal introitus and negative pleiotropy with age at vaginal introitus. Sex ratio and several components of fitness (days from joining to parturition, percent fertile matings and percent perinatal survival) did not change significantly in the selected lines.     

Antibacterial Responses by Peritoneal Macrophages Are Enhanced Following Vitamin D Supplementation

Patients with chronic kidney disease (CKD), who usually display low serum 25-hydroxyvitamin D (25D) and 1,25-dihydroxyvitamin D (1,25D), are at high risk of infection, notably those undergoing peritoneal dialysis (PD). We hypothesized that peritoneal macrophages from PD patients are an important target for vitamin D-induced antibacterial activity. Dialysate effluent fluid was obtained from 27 non-infected PD patients. Flow cytometry indicated that PD cells were mainly monocytic (37.9±17.7% cells CD14⁺/CD45⁺). Ex vivo analyses showed that PD cells treated with 25D (100 nM, 6 hrs) or 1,25D (5 nM, 6 hrs) induced mRNA for antibacterial cathelicidin (CAMP) but conversely suppressed mRNA for hepcidin (HAMP). PD cells from patients with peritonitis (n = 3) showed higher baseline expression of CAMP (18-fold±9, p<0.05) and HAMP (64-fold±7) relative to cells from non-infected patients. In 12 non-infected PD patients, oral supplementation with a single dose of vitamin D₂ (100,000 IU) increased serum levels of 25D from 18±8 to 41±15 ng/ml (p = 0.002). This had no significant effect on PD cell CD14/CD45 expression, but mRNA for HAMP was suppressed significantly (0.5-fold, p = 0.04). Adjustment for PD cell CD14/CD45 expression using a mixed linear statistical model also revealed increased expression of CAMP (mRNA in PD cells and protein in effluent) in vitamin D-supplemented patients. These data show for the first time that vitamin D supplementation in vitro and in vivo promotes innate immune responses that may enhance macrophage antibacterial responses in patients undergoing PD. This highlights a potentially important function for vitamin D in preventing infection-related complications in CKD.     

Acute effects of different external compression with blood flow restriction on force-velocity profile during squat and bench press exercises

The aim was to compare the acute effects of bench press (BP) and squat (SQ) exercises with blood flow restriction (BFR) (40%, 60%, 80% and 100% of the complete arterial occlusion pressure (AOP)) and without BFR (CON) on the mean propulsive (Vel_MED) and maximum (Vel_MAX) bar velocity. Fourteen healthy, physically active males (age, 23.6 ± 4.1 years; height, 1.85 ± 0.11 m; body weight 85.4 ± 4.1 kg) took part in the study. There was one set for each testing condition (CON, 40%, 60%, 80% and 100%) with 6 repetitions for BP and 6 repetitions for SQ, at 60% of 1RM, and 3 minutes of recovery between sets. The results showed statistically significant differences of the sets with 80% BFR vs. CON (mean difference [MD] = 0.035 m · s^-1, p < 0.05, ES = 0.52 [1.02–0.03]) and 100% BFR sets vs. CON (MD = 0.074, p < 0.001, ES = 1.08 [1.79–0.38]) for BP. In the SQ exercise, statistically significant differences were found between 100% BFR vs. CON (DM = 0.031 m · s^-1, p < 0.05), vs. 100% BFR 40% (MD = 0.04 m · s^-1, p < 0.05). Trend analysis showed a statistically significant linear trend (F[1,9] = 34.9, p < 0.001, F[1,13] = 27.32, p < 0.001) for the Vel_MED in relation to the different levels of BFR. In conclusion, our results showed that BFR levels above ˜80% AOP (BP) and ˜100% AOP (SQ) produce a Vel_MED improvement at 60% 1RM.