Effects of eyestalk ablation on growth and food conversion efficiency of the freshwater prawn Macrobrachium lanchesteri (de Man)

Bilateral eyestalk ablation in the freshwater prawn Macrobrachium lanchesteri results in high mortality, while unilateral eyestalk ablated prawns exhibited a high survival rate. There was marked increase in the growth of bilateral eyestalk-ablated prawns (47.70 mg/prawn) as compared to those that were unilaterally ablated (19.19 mg/prawn).     

Effects of different feeding levels on moulting,growth and conversion efficiency of Palaemon lamarrei

Pigment analyses by TLC were carried out during and after the peak of a Peridinium bloom in Lake Kinneret (Israel). During the experimental period considerable changes occurred in the absolute and relative amounts of the various pigments, especially carotene, diadinoxanthine, peridinin, chlorophyll a and chlorophyl c. The ratio between total Carotenoid to total chlorophyll content is also followed. Our findings show that considerable changes in pigment composition in natural phytoplankton can occur while the species composition remains constant.     

Cajanus cajan shows multiple novel adaptations in response to regular mechanical stress

Journal of Plant Research - Cajanus cajan is one of the least studied crop plants regarding its responses to stress conditions. Regular mechanical stress suppresses plant physiology and growth at...     

Laminin-rich blood vessels display activated growth factor signaling and act as the proliferation centers in Dupuytren’s contracture

IntroductionDupuytren’s contracture (DC) is a chronic fibroproliferative disease of the hand, which is characterized by uncontrolled proliferation of atypical myofibroblasts at the cellular level. We hypothesized that specific areas of the DC tissue are sustaining the cell proliferation and studied the potential molecular determinants that might contribute to the formation of such niches.MethodsWe studied the expression pattern of cell proliferation marker Ki67, phosphorylated AKT (Ak mouse strain thymoma) kinase, DC-associated growth factors (connective tissue growth factor (CTGF), basic fibroblast growth factor (bFGF), insulin-like growth factor 2 (IGF-2)) and extracellular matrix components (laminins, fibronectin, collagen IV) in DC tissue and normal palmar fascia using immunofluorescence microscopy and quantitative real-time polymerase chain reaction (qPCR).ResultsWe found that proliferative cells in the DC nodules were concentrated in the immediate vicinity of small blood vessels and localized predominantly in the myofibroblast layer. Correspondingly, the DC-associated blood vessels contained increased levels of phosphorylated AKT, a hallmark of activated growth factor signaling. When studying the expression of potential activators of AKT signaling we found that the expression of bFGF was confined to the endothelium of the small blood vessels, IGF-2 was present uniformly in the DC tissue and CTGF was expressed in the DC-associated sweat gland acini. In addition, the blood vessels in DC nodules contained increased amounts of laminins 511 and 521, which have been previously shown to promote the proliferation and stem cell properties of different cell types.ConclusionsBased on our findings, we propose that in the DC-associated small blood vessels the presence of growth factors in combination with favorable extracellular matrix composition provide a supportive environment for sustained proliferation of myofibroblasts and thus the blood vessels play an important role in DC pathogenesis.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-015-0661-y) contains supplementary material, which is available to authorized users.     

Enhanced activity and stability of cellobiase (β-glucosidase: EC 3.2.1.21) produced in the presence of 2-deoxy-d-glucose from the fungus Termitomyces clypeatus

Generally less glycosylation or deglycosylation has a detrimental effect on enzyme activity and stability. Increased production and secretion of cellobiase was earlier obtained in the presence of the glycosylation inhibitor 2-deoxy-d-glucose in filamentous fungus Termitomyces clypeatus [Mukherjee, S.; Chowdhury, S.; Ghorai, S.; Pal, S.; Khowala, S. Biotechnol. Lett.2006, 28, 1773-1778]. In this study the enzyme was purified from the culture medium by ultrafiltration and gel-permeation, ion-exchange and high-performance liquid chromatography, and its catalytic activity was six times higher compared to the control enzyme. K_m and V_max of the purified enzyme were measured as 0.187 mM and 0.018 U mg⁻¹, respectively, using pNPG as the substrate. The enzyme had temperature and pH optima at 45 °C and pH 5.4, respectively, and retained full activity in a pH range of 5-8 and temperatures of 30-60 °C. Interestingly less glycosylated cellobiase was resistant towards proteolytic as well as endoglycosidase-H digestion and showed higher stability than native enzyme due to increased aggregation of the protein. The enzyme also showed higher specific activity in the presence of cellobiose and pNPG and less susceptibility towards salts and different chemical agents. The β-glucosidase can be considered as a potentially useful enzyme in various food-processing, pharmaceutical and fermentation industries.     

Cellobiase from Termitomyces clypeatus: activity and secretion in presence of glycosylation inhibitors

In presence of the glycosylation inhibitors, 2-deoxy-d-glucose (1 mg/ml), tunicamycin (30 μg/ml), 1-deoxynojirimycin (30 μg/ml) and d-glucono-δ-lactone (1 mg/ml), total cellobiase activity, in the extracellular, intracellular and cell bound fractions, of the fungus Termitomyces clypeatus grown in 20 ml cellobiose medium (1%, w/v) increased by 50-, 1.8-, 2.4-, 1.3-fold, respectively, with respect to control medium (16.3 U). The inhibitors also stimulated secretion of 95% of the total protein in culture medium, except d-glucono-δ-lactone which released 60% of the total protein. 2-Deoxy-d-glucose (1 mg/ml) led to production of extracellular cellobiase up to 40 U/ml, whereas in absence of the inhibitors only 0.59 U/ml enzyme was detected.     

Factors associated with delays in treatment initiation after tuberculosis diagnosis in two districts of India

Background

Excessive time between diagnosis and initiation of tuberculosis (TB) treatment contributes to ongoing TB transmission and should be minimized. In India, Revised National TB Control Programme (RNTCP) focuses on indicator start of treatment within 7 days of diagnosis for patients with sputum smear-positive PTB for monitoring DOTS implementation.

Objectives

To determine length of time between diagnosis and initiation of treatment and factors associated with delays of more than 7 days in smear-positive pulmonary TB.

Methods

Using existing programme records such as the TB Register, treatment cards, and the laboratory register, we conducted a retrospective cohort study of all patients with smear-positive pulmonary TB registered from July-September 2010 in two districts in India. A random sample of patients with pulmonary TB who experienced treatment delay of more than 7 days was interviewed using structured questionnaire.

Results

2027 of 3411 patients registered with pulmonary TB were smear-positive. 711(35%) patients had >7 days between diagnosis and treatment and 262(13%) had delays >15 days. Mean duration between TB diagnosis and treatment initiation was 8 days (range = 0–128 days). Odds of treatment delay >7 days was 1.8 times more likely among those who had been previously treated (95% confidence interval [CI] 1.5–2.3) and 1.6 (95% CI 1.3–1.8) times more likely among those diagnosed in health facilities without microscopy centers. The main factors associated with a delay >7 days were: patient reluctance to start a re-treatment regimen, patients seeking second opinions, delay in transportation of drugs to the DOT centers and delay in initial home visits. To conclude, treatment delay >7 days was associated with a number of factors that included history of previous treatment and absence of TB diagnostic services in the local health facility. Decentralized diagnostic facilities and improved referral procedures may reduce such treatment delays.     

Alteration of testicular biochemistry during protein restriction in nickel treated rats

Nickel sulfate (2.0 mg/100 g.b.wt) dissolved in double-distilled water was administered (ip) on alternate days for ten doses to normal protein-fed and protein-restricted Wister strain albino rats (b.wt. 160 ± 5 g). Two groups were used: one with normal protein diet, whereas the other with protein-restricted diet served as control. Twenty-four hours after the last treatment, the animals were sacrificed by decapitation. Tissues such as the testes, seminal vesicles, epididymis (Cauda and Caput) and prostate were dissected out, wiped clean, and stored at -20‡C until analysis. Lactate dehydrogenase (LDH) activities, glutamate oxaloacetate transaminase (GOT) activities, glycogen content, cholesterol content, and total protein content of the testes were estimated. Nickel sulfate administration significantly decreased the body weight of both normal protein-fed and proteinrestricted groups of animals; the organ weights were also decreased. Significant decrease of LDH activity was observed, but GOT activity was not altered significantly. Testicular glycogen and cholesterol increased significantly in both experimental groups, but total protein content decreased. Nickel sulfate seems to have an adverse effect on the male reproductive system in both groups of animals fed with normal protein (18% casein) diet and protein restricted (5% casein) diet.     

Ligand Binding Turns Moth Pheromone-binding Protein into a pH Sensor: EFFECT ON THE ANTHERAEA POLYPHEMUS PBP1 CONFORMATION*

In moths, pheromone-binding proteins (PBPs) are responsible for the transport of the hydrophobic pheromones to the membrane-bound receptors across the aqueous sensillar lymph. We report here that recombinant Antheraea polyphemus PBP1 (ApolPBP1) picks up hydrophobic molecule(s) endogenous to the Escherichia coli expression host that keeps the protein in the “open” (bound) conformation at high pH but switches to the “closed” (free) conformation at low pH. This finding has bearing on the solution structures of undelipidated lepidopteran moth PBPs determined thus far. Picking up a hydrophobic molecule from the host expression system could be a common feature for lipid-binding proteins. Thus, delipidation is critical for bacterially expressed lipid-binding proteins. We have shown for the first time that the delipidated ApolPBP1 exists primarily in the closed form at all pH levels. Thus, current views on the pH-induced conformational switch of PBPs hold true only for the ligand-bound open conformation of the protein. Binding of various ligands to delipidated ApolPBP1 studied by solution NMR revealed that the protein in the closed conformation switches to the open conformation only at or above pH 6.0 with a protein to ligand stoichiometry of ∼1:1. Mutation of His⁷⁰ and His⁹⁵ to alanine drives the equilibrium toward the open conformation even at low pH for the ligand-bound protein by eliminating the histidine-dependent pH-induced conformational switch. Thus, the delipidated double mutant can bind ligand even at low pH in contrast to the wild type protein as revealed by fluorescence competitive displacement assay using 1-aminoanthracene and solution NMR.