bluuebunny/crossref_metadata_2025_split huggingface dataset:
Alterations in histopathological features and brain acetylcholinesterase activity in stinging catfish Heteropneustes fossilis exposed to polluted river water
Authors: Rakhi Sharmin Ferdewsi , Reza Abdul Hakim Mohammad Mohsinul , Hossen Mohammad Shafaet , Hossain Zakir 
Published: May 2013

Abstract
Responses of stinging catfish (Heteropneustes fossilis) to pollution were studied in three freshwater rivers, namely Buriganga, Turag, and Shitalakkhya (Dhaka, Bangladesh), which are potentially affected by anthropogenic pollution originating from industrial and sewage dumping. Partial parameters about water quality (temperature, dissolved oxygen, and pH) and seasonal plankton fluctuation were recorded at wet and dry seasons. Histopathology and acetylcholinesterase (AChE) activity were used as biomarkers to assess water toxic effects in 7-and 10-day exposures of H. fossilis to three rivers waters, respectively. The lowest level of dissolved oxygen was recorded as 0.7 ± 0.1 mg/l, and the lowest count of plankton genera was 21 at lean period. Furthermore, the 7-day exposure of fish to polluted water abruptly altered the normal structure of various organs. Major structural damages were partial and total epidermal loss, dermis and muscle separation, melanin pigment and vacuole in skin muscle; missing of lamellae, clubbing, fungal granuloma, hyperplasia and hemorrhage in gills; hyperplasia, hemorrhage, pyknosis, vacuole, necrosis, nuclear alteration, fatty degeneration, lipid droplets in liver; degenerating glomerular and tubule, hemorrhage, pyknosis and vacuole in kidneys; and scattered spermatozoa and prominent interstitial space in the testis. After subsequent exposure to polluted water, a significant (P < 0.05) inhibition of AChE activity in the fish brain was observed with the following order of potency: 102.00 ± 5.00 nmol/min/mg protein (Turag) ≥ 104.00 ± 5.00 nmol/min/mg protein (Buriganga) > 130.67 ± 3.51 nmol/min/mg protein (Shitalakkhya). This study confirmed the utility of biomarkers in biomonitoring studies and reflected the potential hazards of pollution to aquatic biota.
Peripheral nervous system insulin resistance in ob/ob mice
Authors: Grote Caleb W , Groover Anna L , Ryals Janelle M , Geiger Paige C , Feldman Eva L , Wright Douglas E 
Published: May 2013

Abstract

Background
A reduction in peripheral nervous system (PNS) insulin signaling is a proposed mechanism that may contribute to sensory neuron dysfunction and diabetic neuropathy. Neuronal insulin resistance is associated with several neurological disorders and recent evidence has indicated that dorsal root ganglion (DRG) neurons in primary culture display altered insulin signaling, yet in vivo results are lacking. Here, experiments were performed to test the hypothesis that the PNS of insulin-resistant mice displays altered insulin signal transduction in vivo. For these studies, nondiabetic control and type 2 diabetic ob/ob mice were challenged with an intrathecal injection of insulin or insulin-like growth factor 1 (IGF-1) and downstream signaling was evaluated in the DRG and sciatic nerve using Western blot analysis.

Results
The results indicate that insulin signaling abnormalities documented in other “insulin sensitive” tissues (i.e. muscle, fat, liver) of ob/ob mice are also present in the PNS. A robust increase in Akt activation was observed with insulin and IGF-1 stimulation in nondiabetic mice in both the sciatic nerve and DRG; however this response was blunted in both tissues from ob/ob mice. The results also suggest that upregulated JNK activation and reduced insulin receptor expression could be contributory mechanisms of PNS insulin resistance within sensory neurons.

Conclusions
These findings contribute to the growing body of evidence that alterations in insulin signaling occur in the PNS and may be a key factor in the pathogenesis of diabetic neuropathy.
Incremental development & revolutions of E-learning software systems in education sector: a case study approach
Authors: Gupta Varun , Chauhan Durg Singh , Dutta Kamlesh 
Published: May 2013

AbstractAdvancement in the area of software engineering, mobile computing together with web technologies have paved way for myriad range of applications, including good quality E-learning software’s, delivering online classes in real time to unlimited number of students across the world, on a personalized E-learning space for every student. These E-learning software systems have virtually made the whole world as a single campus education hub. However, development of these software’s has been a challenge for industry, as the requirement of various stakeholders–learner, educator, institutional management, accreditation bodies, has to be handled in the software effectively. Software systems developed for E-learning applications should implement all the requirements of its diverse stakeholders and must be delivered well in time. Delays, incomplete software and faulty modules could be a big failure for educational institute. To be able to deliver the software within deadline, software’s are delivered in increments. In order to support incremental delivery, paper proposes a new requirement prioritization method that selects those requirements for implementation that are essentially required by stakeholders and has a lower regression count associated with them, thereby reducing regression testing effort.This paper reports the advantages reaped from E-learning software project of “Virtual Classroom” employed in teaching “Multimedia Technologies” course to undergraduate students of sixth semester. Total 50 students, enrolled under both distance education and full time education (25 in each category), were asked a set of questions. Results indicate that E-learning system would bring revolution in the field of education, whether study program is full time, part time or a distance education program. Students found augmenting classroom teaching with the use of E-learning software systems as an enriching experience.
Chaperone Properties of Pdia3 Participate in Rapid Membrane Actions of 1α,25-Dihydroxyvitamin D3
Authors: Chen Jiaxuan , Lobachev Kirill S. , Grindel Brian J. , Farach-Carson Mary C. , Hyzy Sharon L. , El-Baradie Khairat B. , Olivares-Navarrete Rene , Doroudi Maryam , Boyan Barbara D. , Schwartz Zvi 
Published: May 2013

AbstractProtein disulfide isomerase family A, member 3 (Pdia3) mediates many of the plasma membrane (PM)-associated rapid responses to 1α,25-dihydroxyvitamin D3 (1α,25[OH]2D3). It is not well understood how Pdia3, which is an endoplasmic reticulum (ER) chaperone, functions as a PM receptor for 1α,25(OH)2D3. We mutated 3 amino acids (K214 and R282 in the calreticulin interaction site and C406 in the isomerase catalytic site), which are important for Pdia3's ER chaperone function, and examined their role in responses to 1α,25(OH)2D3. Pdia3 constructs with and without the ER retention signal KDEL were used to investigate the PM requirement for Pdia3. Finally, we determined whether palmitoylation and/or myristoylation were required for Pdia3-mediated responses to 1α,25(OH)2D3. Overexpressing the Pdia3 R282A mutant in MC3T3-E1 cells increased PM phospholipase A2-activating protein, Rous sarcoma oncogene (c-Src), and caveolin-1 but blocked increases in 1α,25(OH)2D3-stimulated protein kinase C (PKC) seen in cells overexpressing wild-type Pdia3 (Pdia3Ovr cells). Cells overexpressing Pdia3 with K214A and C406S mutations had PKC activity comparable to untreated controls, indicating that the native response to 1α,25(OH)2D3 also was blocked. Overexpressing Pdia3[−KDEL] increased PM localization and augmented baseline PKC, but the stimulatory effect of 1α,25(OH)2D3 was comparable to that seen in wild-type cultures. In contrast, 1α,25(OH)2D3 increased prostaglandin E2 in Pdia3[±KDEL] cells. Although neither palmitoylation nor myristoylation was required for PM association of Pdia3, myristoylation was needed for PKC activation. These data indicate that both the chaperone functional domains and the subcellular location of Pdia3 control rapid membrane responses to 1α,25(OH)2D3.
Preventing p38 MAPK-Mediated MafA Degradation Ameliorates β-Cell Dysfunction under Oxidative Stress
Authors: El Khattabi Ilham , Sharma Arun 
Published: May 2013

Abstract
The reduction in the expression of glucose-responsive insulin gene transcription factor MafA accompanies the development of β-cell dysfunction under oxidative stress/diabetic milieu. Humans with type 2 diabetes have reduced MafA expression, and thus preventing this reduction could overcome β-cell dysfunction and diabetes. We previously showed that p38 MAPK, but not glycogen synthase kinase 3 (GSK3), is a major regulator of MafA degradation under oxidative stress. Here, we examined the mechanisms of this degradation and whether preventing MafA degradation under oxidative stress will overcome β-cell dysfunction. We show that under oxidative and nonoxidative conditions p38 MAPK directly binds to MafA and triggers MafA degradation via ubiquitin proteasomal pathway. However, unlike nonoxidative conditions, MafA degradation under oxidative stress depended on p38 MAPK-mediated phosphorylation at threonine (T) 134, and not T57. Furthermore the expression of alanine (A) 134-MafA, but not A57-MafA, reduced the oxidative stress-mediated loss of glucose-stimulated insulin secretion, which was independent of p38 MAPK action on protein kinase D, a regulator of insulin secretion. Interestingly, the expression of proteasomal activator PA28γ that degrades GSK3-phosphorylated (including T57) MafA was reduced under oxidative stress, explaining the dominance of p38 MAPK over the GSK3 pathway in regulating MafA stability under oxidative stress. These results identify two distinct pathways mediating p38 MAPK-dependent MafA degradation under oxidative and nonoxidative conditions and show that inhibiting MafA degradation under oxidative stress ameliorates β-cell dysfunction and could lead to novel therapies for diabetes.
Absolute requirement of cholesterol binding for Hedgehog gradient formation in Drosophila
Authors: Ducuing Antoine , Mollereau Bertrand , Axelrod Jeffrey D. , Vincent Stephane 
Published: May 2013

Summary
How morphogen gradients are shaped is a major question in developmental biology, but remains poorly understood. Hedgehog (Hh) is a locally secreted ligand that reaches cells at a distance and acts as a morphogen to pattern the Drosophila wing and the vertebrate neural tube. The proper patterning of both structures relies on the precise control over the slope of Hh activity gradient. A number of hypotheses have been proposed to explain Hh movement and hence graded activity of Hh. A crux to all these models is that the covalent binding of cholesterol to Hh N-terminus is essential to achieve the correct slope of the activity gradient. Still, the behavior of cholesterol-free Hh (Hh-N) remains controversial: cholesterol has been shown to either increase or restrict Hh range depending on the experimental setting. Here, in fly embryos and wing imaginal discs, we show that cholesterol-free Hh diffuses at a long-range. This unrestricted diffusion of cholesterol-free Hh leads to an absence of gradient while Hh signaling strength remains uncompromised. These data support a model where cholesterol addition restricts Hh diffusion and can transform a leveled signaling activity into a gradient. In addition, our data indicate that the receptor Patched is not able to sequester cholesterol-free Hh. We propose that a morphogen gradient does not necessarily stem from the active transfer of a poorly diffusing molecule, but can be achieved by the restriction of a highly diffusible ligand.
Heart rate and estimated energy expenditure of flapping and gliding in black-browed albatrosses
Authors: Sakamoto Kentaro Q. , Takahashi Akinori , Iwata Takashi , Yamamoto Takashi , Yamamoto Maki , Trathan Philip N. 
Published: May 2013

SummaryAlbatrosses are known to expend only a small amount of energy during flight. The low energy cost of albatross flight has been attributed to energy-efficient gliding (soaring) with sporadic flapping, although little is known about how much time and energy albatrosses expend in flapping versus gliding during cruising flight. Here, we examined the heart rates (used as an instantaneous index of energy expenditure) and flapping activities of free-ranging black-browed albatrosses (Thalassarche melanophrys) to estimate the energy cost of flapping as well as time spent in flapping activities. The heart rate of albatrosses during flight (144 beats min-1) was similar to that while sitting on the water (150 beats min-1). In contrast, heart rate was much higher during takeoff and landing (ca. 200 beats min-1). Heart rate during cruising flight was linearly correlated with the number of wing flaps per minute, suggesting an extra energy burden of flapping. Albatrosses expend only 4.6% ± 1.4% of their time in flapping during cruising flight, which was significantly lower than those during and shortly after takeoff (9.8% ± 3.5%). Flapping activity, which amounted to just 4.6% of the time in flight, accounted for 13.3% of the total energy expenditure during cruising flight. These results support the idea that albatrosses achieve energy-efficient flight by reducing the time spent in flapping activity, which is associated with high energy expenditure.
Aluminum exposure impacts brain plasticity and behavior in Atlantic salmon (Salmo salar)
Authors: Grassie Cairsty , Braithwaite Victoria A. , Nilsson Jonatan , Nilsen Tom O. , Teien Hans-Christian , Handeland Sigurd O. , Stefansson Sigurd O. , Tronci Valentina , Gorissen Marnix , Flik Gert , Ebbesson Lars O. E. 
Published: May 2013

Summary
Aluminum (Al) toxicity occurs frequently in natural aquatic ecosystems as a result of acid deposition and natural weathering processes. Detrimental effects of Al toxicity on aquatic organisms are well known and can have consequences for survival. Fish exposed to Al in low pH waters will experience physiological and neuroendocrine changes that disrupt homeostasis and alter behavior. To investigate the effects of Al exposure to both brain and behavior, Atlantic salmon (Salmo salar) kept in water treated with Al (pH 5.7, 0.37±0.04 µmol 1-1 of Al) for 2 weeks were compared to fish kept in a control condition (pH 6.7, &lt;0.04 µmol 1-1 of Al). Fish exposed to Al and acidic conditions had increased Al accumulation in the gills and decreased gill Na+, K+-ATPase activity, which impaired osmoreguatory capacity and caused physiological stress, indicated by elevated plasma cortisol and glucose levels. Here we show for the first time that exposure to Al in acidic conditions also impaired learning performance in a maze task. Al toxicity reduced the expression of NeuroD1 transcript levels in the forebrain of exposed fish. As in mammals, these data show that exposure to chronic stress, such as acidified Al, can reduce neural plasticity during behavioral challenges in salmon, and may impair coping ability to new environments.
The effects of caudal fin loss and regeneration on the swimming performance of three cyprinid fish with different swimming capacities
Authors: Fu Cheng , Cao Zhen-Dong , Fu Shi-Jian 
Published: May 2013

SummaryIn nature, the caudal fins of fish species are frequently lost to some extent by aggressive behaviour, predation and diseases. To test whether the swimming performance of fish with different swimming capacities would be differentially affected due to caudal fin loss and regeneration, we investigated the critical swimming speed (Ucrit), the swimming metabolic rate (MO2), the tail beat frequency (TBF) and the tail beat amplitude (TBA) after caudal fin loss and regeneration (20 days) in juveniles of three cyprinid fish species: the qingbo (Spinibarbus sinensis) (strong swimmer), the common carp (Cyprinus carpio) (intermediate) and the goldfish (Carassius auratus) (poor swimmer). The Ucrits of the caudal-fin-lost qingbo, common carp and goldfish were 49%, 32% and 35% significantly lower than those of the control groups, respectively. The maximum tail beat amplitude (TBAmax) (all three fishes), the maximum tail beat frequency (TBFmax) (only the common carp and the goldfish) and/or the active metabolic rate (MO2active) (only the common carp) of the caudal-fin-lost fish were significantly higher than those of the control groups. After 20 days of recovery, the caudal fins recovered to 41%, 47% and 24% of those of the control groups for the qingbo, the common carp and the goldfish, respectively. However, the Ucrit values of the fin-regenerated qingbo, common carp and goldfish recovered to 86%, 91% and 95% of those of the control group, respectively. The caudal-fin-regenerated qingbo and common carp showed a significantly higher TBAmax and TBFmax, respectively, compared with those of the control groups. The qingbo had a higher TBFmax but a lower TBAmax than the common carp and the goldfish, which suggested that a strong swimmer may maintain swimming speed primarily by maintaining a greater TBFmax, for which the caudal fin plays a more important role during swimming, than a poor swimmer. The MO2active of fish (common carp) with a redundant respiratory capacity could increase due to caudal fin loss to meet the increase in energy expenditure required by an increase in TBFmax. In addition, the sustain swimming performance may not be the only selective pressure acting on caudal fin size in the qingbo, the common carp and the goldfish and the present caudal fin size of these three fish species may be a trade-off between sustain swimming performance and other factors (e. g. sexual selection; escape responses).
Modulation of Rh glycoproteins, ammonia excretion and Na+ fluxes in three freshwater teleosts when exposed chronically to high environmental ammonia
Authors: Sinha Amit K. , Liew Hon J. , Nawata C. Michele , Blust Ronny , Wood Chris M. , De Boeck Gudrun 
Published: May 2013

Summary
We investigated relationships among branchial unidirectional Na+ fluxes, ammonia excretion, urea excretion, plasma ammonia, plasma cortisol, and gill transporter expression and function in three freshwater fish differing in their sensitivity to high environmental ammonia (HEA). The highly ammonia-sensitive salmonid Oncorhynchus mykiss (rainbow trout), the less ammonia-sensitive cyprinid Cyprinus carpio (common carp) and the highly ammonia-resistant cyprinid Carassius auratus (goldfish) were exposed chronically (12 h to 168 h) to 1 mM ammonia (as NH4HCO3; pH 7.9). During HEA, carp and goldfish elevated ammonia excretion (Jamm) and Na+ influx rates (JNain) while trout experienced higher plasma ammonia (Tamm) and were only able to restore control rates of Jamm and JNain. All three species exhibited increases in Na+ efflux rate (JNaout). At the molecular level, there was evidence for activation of a "Na+/NH4+ exchange metabolon” likely in response to elevated plasma cortisol and Tamm, though surprisingly, some compensatory responses preceded molecular responses in all three species. Rhbg, Rhcg (Rhcg-a and Rhcg-b), H+-ATPase (V-type, B-subunit) and Na+/K+-ATPase (NKA) mRNA expressions were up-regulated in goldfish, Rhcg-a and NKA in carp, and Rhcg2, NHE-2 (Na+/H+ exchanger) and H+-ATPase in trout. Branchial H+-ATPase activity was elevated in goldfish and trout, and NKA activity in goldfish and carp, but NKA did not appear to function preferentially as a Na+/NH4+-ATPase in any species. Goldfish alone increased urea excretion rate during HEA, in concert with elevated urea transporter mRNA expression in gills. Overall, goldfish showed more effective compensatory responses towards HEA than carp, while trout were least effective.
Effects of medical therapies for acromegaly on glucose metabolism
Authors: Urbani C , Sardella C , Calevro A , Rossi G , Scattina I , Lombardi M , Lupi I , Manetti L , Martino E , Bogazzi F 
Published: May 2013

ObjectiveAbnormalities of glucose metabolism are common findings of acromegaly. However, robust evidence on whether therapy with somatostatin analogs (SSAs) or pegvisomant (PEG) differently affects glucose metabolism is lacking. The purpose of this study was to evaluate the effects of therapy with SSAs, PEG, or their combination on glucose metabolism in a large series of acromegalic patients.DesignThis was a historical–prospective study. Among 50 consecutive acromegalic patients under SSA therapy, acromegaly in 19 patients was controlled. PEG used in combination with SSA therapy allowed the control of acromegaly in the remaining 31 patients and was then continued as monotherapy in 18 patients.MethodsThe following parameters were evaluated at the diagnosis of acromegaly and during different treatments: fasting plasma glucose (FPG) and insulin concentrations, insulin sensitivity (QUICK-I), homeostasis model assessment of insulin resistance (HOMA2-IR), and plasma glucose and insulin concentrations during the oral glucose tolerance test (OGTT). Comparison was made using analysis for paired data.ResultsInsulin resistance improved when acromegaly was controlled with therapy with SSAs, PEG, or SSA+PEG. However, FPG concentrations were higher during SSA therapy (alone or combined with PEG) than at the diagnosis of acromegaly, even when corrected for disease activity, whereas they were reduced during PEG therapy. Mean glucose concentrations during the OGTT were higher in patients receiving SSA therapy than in those receiving PEG therapy. In addition, the prevalence of diabetes or impaired glucose tolerance was higher during SSA therapy than at diagnosis or during PEG therapy and was not influenced by disease control.ConclusionsMedical therapies for acromegaly reduce insulin resistance and increase insulin sensitivity; on the contrary, glucose indexes may be differently affected by SSA or PEG therapy.
Simultaneous expression analysis of vitamin D receptor, calcium-sensing receptor, cyclin D1, and PTH in symptomatic primary hyperparathyroidism in Asian Indians
Authors: Varshney Shweta , Bhadada Sanjay Kumar , Saikia Uma Nahar , Sachdeva Naresh , Behera Arunanshu , Arya Ashutosh Kumar , Sharma Sadhna , Bhansali Anil , Mithal Ambrish , Rao Sudhaker D 
Published: May 2013

BackgroundTo explore underlying molecular mechanisms in the pathogenesis of symptomatic sporadic primary hyperparathyroidism (PHPT).Materials and methodsForty-one parathyroid adenomas from patients with symptomatic PHPT and ten normal parathyroid glands either from patients with PHPT (n=3) or from euthyroid patients without PHPT during thyroid surgery (n=7) were analyzed for vitamin D receptor (VDR), calcium-sensing receptor (CASR), cyclin D1 (CD1), and parathyroid hormone (PTH) expressions. The protein expressions were assessed semiquantitatively by immunohistochemistry, based on percentage of positive cells and staining intensity, and confirmed by quantitative real-time PCR.ResultsImmunohistochemistry revealed significant reductions in VDR (both nuclear and cytoplasmic) and CASR expressions and significant increases in CD1 and PTH expressions in adenomatous compared with normal parathyroid tissue. Consistent with immunohistochemistry findings, bothVDRandCASRmRNAs were reduced by 0.36- and 0.45-fold change (P<0.001) andCD1andPTHmRNAs were increased by 9.4- and 17.4-fold change respectively (P<0.001) in adenomatous parathyroid tissue.PTHmRNA correlated with plasma PTH (r=0.864;P<0.001), but not with adenoma weight, whileCD1mRNA correlated with adenoma weight (r=0.715;P<0.001). There were no correlations betweenVDRandCASRmRNA levels and serum Ca, plasma intact PTH, or 25-hydroxyvitamin D levels. In addition, there was no relationship between the decreases inVDRandCASRmRNA expressions and the increases inPTHandCD1mRNA expressions.ConclusionsThe expression of both VDR and CASR are reduced in symptomatic PHPT in Asian Indians. In addition,CD1expression was greatly increased and correlated with adenoma weight, implying a potential role for CD1 in adenoma growth and differential clinical expression of PHPT.