Effects Of Physiological Conditions Research Articles

Towards understanding respiratory particle transport and deposition in the human respiratory system: Effects of physiological conditions and particle properties

Fly ash is a common solid residue of incineration plants and poses a great environmental concern because of its toxicity upon inhalation exposure. The inhalation health impacts of fly ash is closely related to its transport and deposition in the human respiratory system which warrants significant research for health guideline setting and inhalation exposure protection. In this study, a series of fly ash transport and deposition experiments have been carried out in a bifurcation airway model by optical aerosol sampling analysis. Three types of fly ash samples of different morphologies were tested and their respiratory deposition and transport processes were compared. The deposition efficiencies were calculated and relevant transport dynamics mechanisms were discussed. The influences of physiological conditions such as breathing rate, duration, and fly ash physical properties (size, morphology, and specific surface area) were investigated. The deposition characteristics of respiratory particles containing SARS-CoV-2 has also been analyzed, which could further provide some guidance on COVID-19 prevention. The results could potentially serve as a basis for setting health guidelines and recommending personal respiratory protective equipment for fly ash handlers and people who are in the high exposure risk environment for COVID-19 transmission.

Association between bilirubin and nonalcoholic fatty liver disease in the non-obese Chinese population: a cross-sectional study.

BackgroundSerum bilirubin may play a role in preventing antioxidant and cytoprotective effects in physiological conditions. Serum bilirubin levels are inversely correlated with insulin resistance and the prevalence of cardiovascular diseases and diabetes mellitus. However, the correlation between serum bilirubin and nonalcoholic fatty liver disease (NAFLD) is unclear. NAFLD in non-obese participants may lead to serious health problems, calling for prompt recognition and early management. This study aimed at investigating the relationship between the serum bilirubin levels and NAFLD in non-obese Chinese adults.MethodsWe evaluated 4,900 non-obese subjects (body mass index <25 kg/m2) residing in Wuwei, China. The subjects received a baseline questionnaire, physical examination, abdominal ultrasonography, and laboratory check-ups. Fasting serum bilirubin was measured with an automated biochemical analyzer. NAFLD was diagnosed based on imaging findings of fatty liver disease on ultrasonography, without excessive alcohol intake and other known causes for chronic liver disease. A logistic regression model was applied to calculate the association between serum bilirubin level and NAFLD in non-obese subjects.ResultsNAFLD was diagnosed in 408 (203 men) of the subjects, and they had a mean age of 51-year-old. Non-obese NAFLD patients had lower serum direct bilirubin (DBIL) levels than control group did [2.50 (1.80–3.25) vs. 2.60 (1.90–3.50), P=0.004], but no significant differences in indirect bilirubin (IBIL) and total bilirubin (TBIL) levels of the two groups was seen (both P>0.05). After adjusting confounding factors such as age, gender, body mass index, blood glucose, and blood lipids, multivariate analysis showed serum DBIL (OR: 0.96, 95% CI: 0.83–1.11, P trend =0.6022), IBIL (OR: 1.02, 95% CI: 0.89–1.17, P trend =0.7756), and TBIL (OR: 1.00, 95% CI: 0.87–1.15, P trend =0.991) levels were not associated with NAFLD in the non-obese population. In addition, subgroup analyses (stratified according to age, gender, and medical histories of hypertension, and diabetes mellitus) suggested no independent association between NAFLD and DBIL, IBIL, or TBIL.ConclusionsOur data suggest that serum bilirubin levels are unlikely to be associated with NAFLD in non-obese subjects.

Towards Understanding Respiratory Particle Transport and Deposition in the Human Respiratory System: Effects of Physiological Conditions and Particle Properties

Towards Understanding Respiratory Particle Transport and Deposition in the Human Respiratory System: Effects of Physiological Conditions and Particle Properties

Serum ADMA levels were positively correlated with EDSS scores in patients with multiple sclerosis

Multiple sclerosis (MS) is an autoinflammatory, chronic central nervous system disease. In the pathogenesis of the disease increased nitric oxide (NO) levels play an important role. Nitric oxide (NO) has neuroprotective effects in physiological conditions, however, it is thought that excessive NO formation in MS may lead to demyelination and axonal damage. Derivatives of methylarginine including asymmetric dimethyl arginine (ADMA), L-N monomethyl arginine (L-NMMA), symmetric dimethyl arginine (SDMA) directly or indirectly reduce NO production. Our aim was to measure the levels of methylarginine derivatives and citrulline, ornithine, arginine, homoarginine levels, which are metabolites associated with NO metabolism, in MS subgroups.

Effect of physiological conditions and biochemical factors of mussels Mytilus galloprovincialis in radioactivity monitoring programs along the Algerian coast.

A study was carried out to determine the activities of radionuclides (137Cs, 40K, 226Ra, 214Bi, 214Pb, and 210Pb) and the levels of biochemical components (lipids, carbohydrates, and proteins) in mussels (Mytilus galloprovincialis) along the Algerian coast. The goal was to evaluate the effect of mussels' biological parameters on radionuclide concentrations, through two coastal water biomonitoring programs. The mussels were taken from three study areas on the Algerian coast: Kristel (Oran), Surcouf (Alger), and Collo (Skikda), for the passive biomonitoring program and transplanted from each study area into the control site of Surcouf. Biochemical components were determined by means of UV-visible colorimetric assays, while the activity concentrations of radionuclides were measured by gamma-ray spectrometry. The results showed that carbohydrates were the most abundant biochemical components (40-60%) compared with proteins (20-40%) and lipids (15-20%). 137Cs activity concentrations were below the lower limit of detection (LOD) for all samples, while the high activities of 40K are the result of its behavior as stabile potassium K which is extensively used in the metabolism of mussels reflects the conditional state of mussels. 210Pb concentration reflects the conditional state of mussels (morphometric parameters and proteins content). The mussels' bioaccumulation capacity for radionuclides was found to be dependent on the growing site and the biomonitoring time period.

Effects of Physiological Condition on Aspects of Repeat Spawning in Female Steelhead Reconditioned in Captivity

AbstractPhysiological condition (hereafter shortened to “condition”) influences survival, spawning schedules, and reproductive effort in salmonids. In iteroparous females, the effects of first spawning on condition could result in trade‐offs with future reproduction, mediated by postspawning survival, repeat spawning schedule (i.e., consecutive or skip spawning), or reproductive effort. However, which aspects of condition affect these outcomes and when they are sensitive to condition are not well understood. These issues were examined in highly energy‐depleted hatchery‐origin female summer steelhead Oncorhynchus mykiss that were undergoing postspawning reconditioning in captivity. Measures of condition and reproductive characteristics (i.e., fecundity, egg size, and total egg mass [TEM]) at first spawning were examined for their effects on postspawning survival and future spawning schedules, and condition was tracked during reconditioning to examine effects on reproductive characteristics at repeat spawning. The levels of plasma osmolality and triglycerides measured at first spawning were positively correlated with survival probability, suggesting that survival depends on the ability to maintain homeostasis and access stored energy. Surprisingly, size‐standardized TEM measured at first spawning was positively correlated with the probability of consecutive spawning, providing no support for the hypothesized trade‐off between current and future reproduction. This finding instead suggests that both first‐spawning reproductive effort and consecutive spawning may be influenced by condition at earlier points. Plasma triglycerides and growth rates at sampling points 10–20 weeks after first spawning were strongly correlated with size‐standardized egg size and TEM at consecutive spawning, suggesting that reproductive effort and its allocation to egg size and fecundity depend on energetic status during early oogenesis. These results indicate that condition influences survival, repeat spawning schedules, and reproductive characteristics in female steelhead up to a year or more before repeat spawning. If more broadly applicable, these relationships could provide insight into the mechanisms that link environmental conditions with reproductive characteristics in salmonids and other species.

Interactions between Sclerostin and Glycosaminoglycans.

Sclerostin (SOST) is a glycoprotein having many important functions in the regulation of bone formation as a key negative regulator of Wnt signaling in bone. Surface plasmon resonance (SPR), which allows for a direct quantitative analysis of the label-free molecular interactions in real-time, has been widely used for the biophysical characterization of glycosaminoglycan (GAG)-protein interactions. In the present study, we report kinetics, structural analysis and the effects of physiological conditions (e.g., salt concentrations, Ca2+ and Zn2+concentrations) on the interactions between GAGs and recombinant human (rh) and recombinant mouse (rm) SOST using SPR. SPR results revealed that both SOSTs bind heparin with high affinity (rhSOST-heparin, KD~36nM and rmSOST-heparin, KD~77nM) and the shortest oligosaccharide of heparin that effectively competes with full size heparin for SOST binding is octadecasaccharide (18mer). This heparin binding protein also interacts with other highly sulfated GAGs including, disulfated-dermatan sulfate and chondroitin sulfate E. In addition, liquid chromatography-mass spectrometry was used to characterize the structure of sulfated GAGs that bound to SOST.

Synthesis and characterization of new branched magnetic nanocomposite for loading and release of topotecan anti-cancer drug

The purpose of this study is to synthesize the new branched magnetic nanocomposite to carry the therapeutic agents and bio-macromolecules. Although topotecan (TPT) has significant antitumor activity to lung, ovarian, breast, pancreas, and stomach cancers, lactone ring opening causes a reduction in cytotoxic activity and severe side effects in physiological conditions. In order to contribute to the removal of the handicap (lactone ring opening), magnetic dextran branched with NαNα-Bis (carboxymethyl)-l-lysine hydrate (NTA) nanoparticles (MD3) were prepared. The characterization of the resulting MD3 material was done by using multi-pronged analyses. The stability and release of TPT with synthesized and characterized new material of the MD3 was studied using various essential factors like concentration, dosage, pH, and time. The entrapment efficiency and loading capacity of TPT onto MD3 was calculated as 32.2% and 1.44 mg/g, respectively, at pH 5. Release studies were performed with drug-loaded MD3 at different pH values. It was seen that the best release was obtained at the cancerous site pH. Initial drug concentration was measured as 0.118 mM. The loaded drug concentration was calculated as 0.0380 mM at pH 5 and 0.00092 mM of drug was released after 90 min at pH 5.8. Percentage released of drug was found as 2.42% during 90 min.Graphical abstract

Molecular Alterations and Effects of Acute Dehydroepiandrosterone Treatment Following Brief Bilateral Common Carotid Artery Occlusion: Relevance to Transient Ischemic Attack

Transient ischemic attack (TIA) represents brief neurological dysfunction of vascular origin without detectable infarction. Despite major clinical relevance characterization of post-TIA molecular changes using appropriate experimental model is lacking and no therapeutic agent has been established yet. Neurosteroid dehydroepiandrosterone (DHEA) arose as one of the candidates for cerebral ischemia treatment but its effects on TIA-like condition remain unknown. Seeking an animal model applicable for investigation of molecular alterations in mild ischemic conditions such as TIA, 15-min bilateral common carotid artery occlusion with 24-h reperfusion was performed to induce ischemia/ reperfusion (I/R) injury in adult male Wistar rats. Additionally, effects of 4-h post-operative DHEA treatment (20 mg/kg) were investigated in physiological and I/R conditions in hippocampus (HIP) and prefrontal cortex (PFC). The study revealed absence of sensorimotor deficits, cerebral infarcts and neurodegeneration along with preserved HIP and PFC overall neuronal morphology and unaltered malondialdehyde and reduced glutathione level following I/R and/or DHEA treatment. I/R induced nitric oxide burst in HIP and PFC was accompanied with increased neuronal nitric oxide synthase protein level exclusively in HIP. DHEA had no effects in physiological conditions, while increase of Bax/Bcl2 ratio and dissipation of mitochondrial membrane potential in treated I/R group suggested DHEA-mediated exacerbation of post-ischemic changes that might lead to pro-apoptotic events in HIP. Interestingly, DHEA restored I/R-induced NO to the control level in PFC. Obtained results indicated that I/R may serve as an appropriate model for investigation of molecular changes and treatment outcome following mild ischemic conditions such as TIA.

Strategies Targeting DNA Topoisomerase I in Cancer Chemotherapy: Camptothecins, Nanocarriers for Camptothecins, Organic Non-Camptothecin Compounds and Metal Complexes.

Topoisomerase I (Topo I) is a nuclear enzyme engaged in adjustment of DNA topological structure during cell cycle by cleaving and reannealing one of the two strands of the DNA double helix. Inhibition of this enzyme results in DNA strand breaks, ultimately leads to apoptosis and cell death; additionally it is in raised level in solid tumors contrasted with healthy tissues. Consequently, Topo I has a great potential as a target for the treatment of tumors. Although significant anti-tumor activity of first Topo I inhibitor, camptothecin (CPT), was observed on colon, lung, ovarian, breast, liver, pancreas and stomach cancers, CPT and its clinical derivatives (topotecan and irinotecan) have several restrictions. In addition to their low water solubility and cell resistance to CPTs, lactone ring opening causes a reduction in cytotoxic activity and severe side effects in physiological conditions (pH: 7.4, 37°C). Although numerous efficient nano drug delivery systems were developed for CPT and its derivatives to compensate the handicaps of these compounds, none of them has been approved so far. On the other hand, organic non-CPT compounds have been searched; indolocarbazoles, indenoisoquinolines and dibenzonaphthyridines have been applied to clinical development. Especially, indenoisoquinolines and dibenzonaphthyridines have favorable characteristics compared to CPTs: They are chemically stable; they have the ability to overcome cell resistance; they stabilize enzyme-DNA cleavage complexes more persistently. In addition to the approaches based on organic compounds, recently some metal complexes (e.g., platinum, gold, copper, cobalt, zinc, vanadium, ruthenium) have also been reported as inhibitors of Topo I. This review will discuss the whole aspects of strategies targeting Topo I in cancer chemotherapy from past to the recent progresses.

Kinetic and Structural Studies of Interactions between Glycosaminoglycans and Langerin.

Langerin, a C-type lectin, is expressed in Langerhans cells. It was reported that langerin binds sulfated glycans, which is an important initial step for its role in blocking human immunodeficiency virus (HIV) transmission by capturing HIV pathogens and mediating their internalization into Birbeck granules for their elimination. It is fundamentally important to understand these interactions at the molecular level for the design of new highly specific therapeutic agents for HIV. Surface plasmon resonance (SPR), which allows for the real-time, direct, quantitative analysis of the label-free molecular interactions, has been used successfully for biophysical characterization of glycosaminoglycan (GAG)-protein interactions. In this study, we report kinetics, structural analysis, and the effects of physiological conditions (e.g., pH, salt concentration, and Ca(2+) and Zn(2+)concentrations) on the interactions between GAGs and langerin using SPR. SPR results revealed that langerin binds to heparin with high affinity (KD ∼ 2.4 nM) and the oligosaccharide length required for the interactions is larger than a tetrasaccharide. This heparin/heparan sulfate-binding protein also interacts with other GAGs, including dermatan sulfate, chondroitin sulfates C-E and KS. In addition, liquid chromatography-mass spectrometry analysis was used to characterize the structure of sulfated glycans that bound to langerin.

Camptothecin Anticancer Drug Loaded Iron Oxide Micro and Nanoparticles: Tuning Targeted and Sustained Release of the Drug in Bioactive Form#

Although Camptothecin (CPT) has significant antitumor activity to lung, ovarian, breast, pancreas, and stomach cancers; lactone ring opening causes a reduction in cytotoxic activity and severe side effects in physiological conditions (pH: 7.4, 37°C) due to decreased cell membrane binding, membrane diffusibility, and intrinsic potency against the topoisomerase target. Taken into consideration the targeted delivery advantage of biocompatible magnetic particles, in order to contribute to the removal of the handicap (lactone ring opening), the current study investigated stability, release, and in vitro bioactivity of CPT in oleic acid (OA)-pluronic F127 (PL) coated iron oxide micro and nanoparticles. CPT encapsulated magnetite micro (~10 μm) and nano (~30 nm) formulations were synthesized without changing their magnetic properties. Analysis of encapsulated CPT illustrated that over 99% of the lactone form was protected in the magnetic particle formulations and release of CPT from the magnetic micro and nanoparticles lasted for 9 and 4 days respectively. In addition, in a representative in vitro cytotoxicity study, CPT encapsulated OA-PL stabilized magnetite microparticles were approximately 65% more effective than free CPT to inhibit 100% cell growth on three different human liver carcinoma cell lines. Therefore, the OA-PL stabilized iron oxide formulation is ideal for achieving targeted and sustained CPT delivery in bioactive lactone form to overcome its handicaps in clinical conditions.

Study of the Effects of Changing Physiological Conditions on Dielectric Properties of Breast Tissues

This paper addresses the changes in the physical characteristics (temperature and water/blood content) of breast tissue under different physiological conditions. We examined ex vivo specimens of breast tissue excised at the time of surgery to study the effects of physiological conditions on dielectric properties. We observed that the dielectric properties strongly depend on tissue physiological state. When the biological tissues undergo physiological changes, such as those due to disease or those induced by external changes such as variations in the environmental temperature, the microscopic processes deviate from their normal state and impact the overall dielectric properties. This suggests that microwave imaging might be used to monitor the physiological conditions of the body.

The effect of physiological conditions on the surface structure of proteins: Setting the scene for human digestion of emulsions

Understanding and manipulating the interfacial mechanisms that control human digestion of food emulsions is a crucial step towards improved control of dietary intake. This article reports initial studies on the effects of the physiological conditions within the stomach on the properties of the film formed by the milk protein (β-lactoglobulin) at the air-water interface. Atomic force microscopy (AFM), surface tension and surface rheology techniques were used to visualize and examine the effect of gastric conditions on the network structure. The effects of changes in temperature, pH and ionic strength on a preformed interfacial structure were characterized in order to simulate the actual digestion process. Changes in ionic strength had little effect on the surface properties. In isolation, acidification reduced both the dilatational and the surface shear modulus, mainly due to strong repulsive electrostatic interactions within the surface layer and raising the temperature to body temperature accelerated the rearrangements within the surface layer, resulting in a decrease of the dilatational response and an increase of surface pressure. Together pH and temperature display an unexpected synergism, independent of the ionic strength. Thus, exposure of a pre-formed interfacial β-lactoglobulin film to simulated gastric conditions reduced the surface dilatational modulus and surface shear moduli. This is attributed to a weakening of the surface network in which the surface rearrangements of the protein prior to exposure to gastric conditions might play a crucial role.

2P218 分子ものさしを用いた核小体内の微環境とその生理条件の影響の解析(細胞生物的課題(接着・運動・骨格・伝達・膜)))

2P218 分子ものさしを用いた核小体内の微環境とその生理条件の影響の解析(細胞生物的課題(接着・運動・骨格・伝達・膜)))

Home-range Size and Habitat Selection of Female Wild Turkeys (Meleagris gallopavo) in Arkansas

Eastern wild turkeys (Meleagris gallopavo silvestris) in the Ouachita Highland Province of westcentral Arkansas have some of the largest reported home ranges for this subspecies. Previous research on wild turkeys has generally attributed large home-range size to forage abundance or quality. However, limitations in reproduction by wild turkeys in the Ouachitas may influence home-range size and habitat selection. To discern factors governing home-range size, I examined habitat use by 54 female wild turkeys from 1993 to 1996. Shortleaf pine (Pinus echinata) and mixed pine–hardwood sawtimber were selected over other overstory cover types, whereas blackgum (Nyssa sylvatica), red maple (Acer rubrum) and white oak (Quercus alba) were favored in the understory. Mean fixed kernel home-range size during the breeding season was 18.9 km2, the largest reproductive period home range reported for the eastern subspecies. Home-range size varied as a function of age, body mass, reproductive status and the structure of selected habitats. Subadult females occupied larger home ranges (x̄ = 32.0 km2, se = 7.0) than adult females (16.3 ± 1.7 km2) and moved greater distances between nest sites in subsequent years (8.9 ± 1.8 km vs. 2.4 ± 1.1 km, respectively). After removing effects of age, heavier females occupied smaller home ranges than lighter females. Nesting individuals occupied less area than non-nesters, and female turkeys that occupied smaller areas avoided stands of seedlings and saplings in favor of mature poletimber. Taken together, effects of physiological condition and experience influenced home-range size in female wild turkeys in westcentral Arkansas.

Effects of physiological condition and experience on oviposition behaviour of Trichogramma australicum Girault (Hymenoptera: Trichogrammatidae) on eggs of Helicoverpa armigera Hübner (Lepidoptera: Noctuidae)

We produced an ethogram for and investigated effects of physiological condition and experience on oviposition behaviour for Trichogramma australicum on Helicoverpa armigera eggs. The data, coupled with the ethogram, have enabled the establishment of standard behavioural categories which can be used to assess acceptability of H. armigera eggs to T. australicum reared in vitro or in eggs of other species. Physiological and experiential conditions were investigated using females of three different ages (0–24, 24–48 and 48–72 h old), two types of sexual states (mated and unmated) and two types of ovipositional experience (naive and experienced). Durations of host finding, host examination, and post‐ovipositional re‐examination were reduced by oviposition experience and were shorter in younger females (0–48 h old). Oviposition experience reduces the duration of the drilling and percentage of females host‐feeding. Being mated and young reduces the host examination time in subsequent oviposition bouts. Only ovipositionally inexperienced females host‐feed before oviposition and host‐fed more frequently than experienced individuals after oviposition. Host‐feeding needs consideration for optimal culture.

Recent Increase in Male House Finch Plumage Variation and Its Possible Relationship to Avian Pox Disease

Male House Finches (Carpodacus mexicanus) in southern California show a large range of plumage variation, with individuals varying along a continuum from yellow to orange to red. This extreme variation is largely unrelated to age and is likely to have fitness consequences (e.g. Hill 1990, 1991; Belthoff 1994; Thompson et al. 1997). New analyses based on museum specimens, a literature review, and recently captured individuals indicate that the high level of variation is a new phenomenon because most males were red prior to the 1950s, whereas half or more are currently orange or yellow. The change toward orange and yellow plumage may be related to a high incidence of avian pox that was first noted in the early 1970s but probably began earlier. In addition to a temporal link between pox and plum- age variation in California, there is also a geographic link. Pox is very common in Hawaii, where most males are orange or yellow, but rare or absent on San Nicolas Island off the coast of southern California and in eastern North America. At least 90% of the males are red in each of these two latter areas. The link between pox and plumage color may occur as an effect of physiological condition, pathogen virulence, or host resistance among populations,

Distribution of Free D-Amino Acids in Bivalve Mollusks and the Effects of Physiological Conditions on the Levels of D- and L-Alanine in the Tissues of the Hard Clam, &lt;i&gt;Meretrix lusoria&lt;/i&gt;

Distribution of Free D-Amino Acids in Bivalve Mollusks and the Effects of Physiological Conditions on the Levels of D- and L-Alanine in the Tissues of the Hard Clam, &lt;i&gt;Meretrix lusoria&lt;/i&gt;

Effect of physiological conditions on the autolysis ofStaphylococcus aureus strains

The effect of physiological conditions on autolysis and autolytic activity in various strains of Staphylococcus aureus was determined. The rate of whole cell autolysis of S. aureus was growth phase dependent and a maximum rate was observed in early stationary phase cultures. However, the autolysins extracted by the freeze-thaw method (cell-wall bound autolytic activity) did not show any significant increase in activity. The addition of NaCl to the growth medium enhanced the rate of autolysis with the highest rate being displayed by cultures grown in 1.5 M NaCl. However, lower autolytic activity was found in the freeze-thaw extracts of cultures grown at higher concentrations of NaCl. The rate of autolysis of cultures grown at 30 degrees C was higher than cultures grown at 37 or 43 degrees C. Thus, the rate of autolysis seems to be independent of the bacterial growth rate. Cultures grown in slightly acidic conditions showed a faster rate of autolysis compared to cultures grown under alkaline conditions. SDS-polyacrylamide gel containing 0.2% crude cell-wall of S. aureus did not show any obvious correlation with the appearance of any particular lytic band in the zymogram to autolytic activity or rate of autolysis of cultures grown under various environmental conditions. A nonhemolytic phenotype, mutations in the accessory gene regulator, and lysogeny (phages phi 11, phi 12, phi 13) had no obvious effect either on the rate of autolysis or on the pattern of lytic bands in the zymograms.