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D Period (d + period)
Selected AbstractsBacillus subtilis strain deficient for the protein-tyrosine kinase PtkA exhibits impaired DNA replicationMOLECULAR MICROBIOLOGY, Issue 6 2007Dina Petranovic Summary Bacillus subtilis has recently come into the focus of research on bacterial protein-tyrosine phosphorylation, with several proteins kinases, phosphatases and their substrates identified in this Gram-positive model organism. B. subtilis protein-tyrosine phosphorylation system PtkA/PtpZ was previously shown to regulate the phosphorylation state of UDP-glucose dehydrogenases and single-stranded DNA-binding proteins. This promiscuity towards substrates is reminiscent of eukaryal kinases and has prompted us to investigate possible physiological effects of ptkA and ptpZ gene inactivations in this study. We were unable to identify any striking phenotypes related to control of UDP-glucose dehydrogenases, natural competence and DNA lesion repair; however, a very strong phenotype of ,ptkA emerged with respect to DNA replication and cell cycle control, as revealed by flow cytometry and fluorescent microscopy. B. subtilis cells lacking the kinase PtkA accumulated extra chromosome equivalents, exhibited aberrant initiation mass for DNA replication and an unusually long D period. [source] High-dose glucose-insulin-potassium treatment reduces myocardial apoptosis in patients with acute myocardial infarctionEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 3 2005L. Zhang Abstract Background, Several clinical trials have suggested that a metabolic cocktail of glucose-insulin-potassium (GIK) decreases mortality rates in patients with acute myocardial infarction (AMI). It has also been reported that Fas-mediated apoptosis plays an important role in ischaemic/reperfusion injury in the rat model. This study was designed to evaluate the interaction of ischaemic/reperfusion and reperfusion therapy coadministered with high-dose GIK treatment on soluble Fas/APO-1 (sFas) and Fas ligand (sFasL) plasma concentration in patients with AMI. Materials and methods, Seventy-four patients presenting with AMI who underwent reperfusion therapy were randomized into a GIK group (n = 35) receiving high-dose GIK for 24 h or a vehicle group (n = 39). Thirty-four control subjects were also enrolled in the present study. Strepavidin-biotin ELISA was used to determine the soluble sFas and sFasL plasma concentration at baseline, 24 h (h), 3 day (d), 7 d and 14 d. Results, Soluble Fas and sFas-L serum concentrations ([sFas] and [sFas-L]) of patients with AMI were significantly elevated at baseline as compared with normal controls (NCs; P < 0·01 vs. NC). The sFas in the GIK and vehicle groups markedly decreased 24 h after the GIK infusion (10·7,5·9 ng mL,1 and 9·7,6·5 ng mL,1; P < 0·01 vs. baseline) and then increased during the 3,7-d period (5·9,12·1 ng mL,1 and 6·5,11·1 ng mL,1; P < 0·01 vs. 24 h). The GIK group demonstrated reduced sFas (12·1,5·9 ng mL,1) at 14 d (P < 0·01 vs. 7 d), with no concomitant changes in the vehicle group. The sFas-L in the GIK and vehicle groups was not significant different during the 14-d period. Conclusions, These results indicate that the sFas and sFasL in patients with AMI increased significantly compared with NC. Owing to the cardioprotective effects reported here and by others, a high-dose GIK infusion co-administered with the timely re-establishment of nutritive perfusion should be strongly considered as a treatment of choice for AMI. Additionally, sFas may be a valuable marker of the physiological response to ischaemic/reperfusion injury and reperfusion associated with high-dose GIK treatment. [source] Tin-containing fluoride solutions as anti-erosive agents in enamel: an in vitro tin-uptake, tissue-loss, and scanning electron micrograph studyEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 4 2009Nadine Schlueter Tin-containing fluoride solutions can reduce erosive tissue loss, but the effects of the reaction between tin and enamel are still not clear. During a 10-d period, enamel specimens were cyclically demineralized (0.05 M citric acid, pH 2.3, 6 × 5 min d,1) and remineralized (between the demineralization cycles and overnight). In the negative-control group, no further treatment was performed. Three groups were treated (2 × 2 min d,1) with tin-containing fluoride solutions (400, 1,400 or 2,100 ppm Sn2+, all 1,500 ppm F,, pH 4.5). Three additional groups were treated with test solutions twice daily, but without demineralization. Tissue loss was determined profilometrically. Energy-dispersive X-ray spectroscopy was used to measure the tin content on and within three layers (10 ,m each) beneath the surface. In addition, scanning electron microscopy was conducted. All test preparations significantly reduced tissue loss. Deposition of tin on surfaces was higher without erosion than with erosion, but no incorporation of tin into enamel was found without demineralization. Under erosive conditions, both highly concentrated solutions led to the incorporation of tin up to a depth of 20 ,m; the less-concentrated solution led to small amounts of tin in the outer 10 ,m. The efficacy of tin-containing solutions seems to depend mainly on the incorporation of tin into enamel. [source] Treatment of a Chromate-Contaminated Soil Site by in situ Gaseous ReductionGROUND WATER MONITORING & REMEDIATION, Issue 1 2007E.C Thornton A proof-of-concept field test for the treatment of hexavalent chromium in the vadose zone using in situ gaseous reduction was successfully completed by the U.S. Department of Energy and U.S. Department of Defense in a joint demonstration conducted at White Sands Missile Range, New Mexico. The test involved injecting hydrogen sulfide, diluted in air, into contaminated vadose zone sediment to reduce Cr(VI) to Cr(III). The gaseous mixture was injected directly into the contaminated sediment through a central injection well and vacuum extracted through the flow field with six boreholes at the site periphery over a 76-d period. Comparison of soil samples taken before and after the test indicated 70% of the total mass of hexavalent chromium originally present at the site was reduced and immobilized. The zone of highest contamination was nearly completely treated, with average Cr(VI) concentrations decreasing in this interval from an average of 8.1 mg/kg before treatment to 1.1 mg/kg after treatment. Treatment was best in higher permeability clean gypsum sands and less effective in zones containing greater amounts of silt and clay and a slightly higher iron content. All hexavalent chromium concentrations measured in the posttest samples, however, were well below the remedial goal and regulatory limit of 30 mg/kg. In addition, the field test demonstrated that vadose zone treatment of contamination can be safely conducted using diluted hydrogen sulfide gas mixtures. Ongoing development of the technology is being directed toward addressing the limitations of gaseous treatment arising from variations in sediment permeability and iron content and assessing the relationship between hydrogen sulfide consumption and reaction kinetics. [source] Flavor Fade in Peanuts During Short-term StorageJOURNAL OF FOOD SCIENCE, Issue 3 2006Jodi E Williams ABSTRACT: Flavor characteristics of roasted peanuts over short-term storage were explored through sensory and chemical analyses. The volatiles from freshly roasted peanuts were evaluated over short-time (21 d) storage using gas chromatography, chemosensory techniques, and a sensory panel to quantify and identify pyrazines and hexanal over a 21-d storage period. A significant decrease (P < 0.05) was noted in 2,3-diethylpyrazine, 2-methoxypyrazine, 2,3-dimethylpyrazine, 2-ethyl-3-methylpyrazine, and 2,3,5-trimethylpyrazine concentrations over a 21-d period. No significant difference (P > 0.05) was noted in the 2-methylpyrazine and 2-ethylpyrazine concentrations. The hexanal concentration significantly increased (P < 0.05) over the 21-d period. The peroxide values and sensory analysis agreed with these results. A significant increase (P < 0.05) in peroxide value was seen at days 14 and 21, and a significant decrease (P < 0.05) in fresh roasted peanuty flavor from day 0 to 21 and significant increases (P < 0.05) in painty, cardboardy, and bitter flavors from day 7 to 21 with the sensory analysis. The electronic nose successfully separated day 0 and 21 samples from day 7 and 14 samples, which were also separated but with some overlap. [source] Changes of Volatile Compounds, Lactic Acid Bacteria, pH, and Headspace Gases in Kimchi, a Traditional Korean Fermented Vegetable ProductJOURNAL OF FOOD SCIENCE, Issue 3 2003J.H. Kang ABSTRACT Headspace volatiles of Kimchi stored at 5 °C increased over a 7 d period by 20.0% and then decreased from 7 to 27 d by 8.3%. Forty volatile compounds including 18 sulfur compounds were identified in Kimchi. Lactic acid bacteria in Kimchi increased from 3.1 to 4.5 (1 × 108cfu/mL) over a 17-d period and decreased by 40% from 17 to 27 d. As the storage time increased from 2 to 27 d, pH decreased from 4.3 to 3.8, headspace oxygen decreased from 14.3 to 1.3%, and headspace carbon dioxide increased from 27.7 to 45.3%. Enzymatic reactions and chemical oxidations in Kimchi explained the changes of volatile compounds, lactic acid bacteria, pH, headspace oxygen and carbon dioxide. [source] PULSES OF PHOSPHATE PROMOTE DOMINANCE OF THE TOXIC CYANOPHYTE CYLINDROSPERMOPSIS RACIBORSKII IN A SUBTROPICAL WATER RESERVOIR,JOURNAL OF PHYCOLOGY, Issue 3 2009Amanda J. Posselt The role of dissolved inorganic phosphorus (DIP) in promoting dominance of the toxic nitrogen (N)-fixing cyanobacterium Cylindrospermopsis raciborskii (Wo,osz.) Seenayya et Subba Raju was examined in a subtropical water reservoir, Lake Samsonvale (=North Pine reservoir). A novel in situ bioassay approach, using dialysis tubing rather than bottles or bags, was used to determine the change in C. raciborskii dominance with daily additions of DIP. A statistically significant increase in dominance of C. raciborskii was observed when DIP was added at two concentrations (0.32 ,M and 16 ,M) in a daily pulse over a 4 d period in three separate experiments in the summer of 2006/2007. There was an increase in both C. raciborskii cell concentrations and biovolume in two DIP treatments, but not in the ammoniacal N + DIP treatment. In addition, overall phytoplankton cell concentrations increased with DIP addition, indicating that Lake Samsonvale was DIP limited at the time of experiments. Given the bioassay response, it is likely that dominance of C. raciborskii could increase in Lake Samsonvale with periodic injections of DIP such as inflow events. [source] Effects of Periodic Feed Deprivation on Growth, Feed Efficiency, Processing Yield, and Body Composition of Channel Catfish Ictalurus punctatusJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 4 2005Menghe H. Li Two studies were conducted in 110-L flow-through aquaria and 0.4-ha ponds to evaluate effects of periodic feed deprivation on the growth performance of channel catfish Ictalurus punctatus. Fish were deprived of feed 0, 1, 2, or 3 consecutive d/wk, l d per 5-d period, or 3 consecutive d per 10-d period and fed to satiation on days fish were fed. In Experiment 1, fish fed less frequently than daily consumed significantly less feed (over the experimental period) and gained significantly less weight than fish fed daily, except that feed consumption of fish deprived of feed 1 d/wk was not significantly different from that of fish fed daily. Compared with fish fed daily, fish deprived of feed 2 d/wk had significantly lower feed conversion ratio (FCR). Visceral fat of fish deprived of feed 1 or 2 d/wk was similar to that of fish fed daily, but fish deprived of feed for longer periods had significantly lower visceral fat than fish fed daily. Regression analysis indicated that feed consumption, weight gain, and visceral fat increased linearly as the number of days that fish were fed increased. In Experiment 2, there were no significant differences in the amount of feed fed between fish deprived of feed 1 d/wk and those fed daily. Net production of fish deprived of feed 1 or 2 d/wk or 1 d per 5-d period was not significantly different from that of fish fed daily, but fish deprived of feed for longer periods had significantly lower net production than fish fed daily. Visceral fat of fish deprived of feed 1 d/wk or 1 d per 5-d period was similar to that of fish fed daily, but fish on other treatments had significantly lower visceral fat than fish fed daily. Regression analysis showed that as the number of days fed increased the amount of feed fed and net production increased quadratically. Feed conversion ratio, carcass yield, visceral fat, and fillet fat increased, while fillet moisture decreased linearly as the number of days fed increased. Although feeding less frequently than daily may improve feed efficiency, and fish deprived of feed may demonstrate compensatory growth when a full feeding regime is resumed, it may be difficult to provide enough feed to satiate all size-classes of fish under a multiple-batch cropping system without causing water quality problems. Under normal economic conditions, fish should be fed daily to apparent satiation without waste and without causing water quality problems. However, during periods of unfavorable economic conditions, channel catfish raised from advanced fingerlings to market size may be fed less frequently than daily to reduce production cost. Results from the present study indicated that feeding channel catfish to satiation 5 or 6 d/wk (not feeding on one or two weekend days) could provide some benefits in reducing production cost through reduced feed and labor costs for food-sized channel catfish during periods of low fish prices and high feed prices. [source] Changes in Plasma Cortisol, Glucose, and Selected Blood Properties in the Summer Flounder Paralichthys dentatus Associated with Sequential Movement to Three Experimental ConditionsJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 3 2003James A. Sulikowski To determine the changes in blood chemistry associated with sequential transfer of summer flounder Paralichthys dentatus (320,480 g), 300 hatchery-reared fish were moved to three different environmental conditions during a 20-d period. Fish were transferred in progression from a recirculating seawater system (22 ppt, 22.5 C) to a flow-thru seawater system (31 ppt, 20.0 C), to three small coastal net pens (33 ppt, 15.5 C), and finally to a large open ocean net pen (33 ppt, 16.0 C). For this study, eight random fish were captured at each progressive step (environmental condition), anesthetized (MS222), and bled from the caudal vein (2 mL). Transferred flounder were bled every 12 h for 48 h to collect plasma cortisol and glucose samples. Fish were bled 24 h after transport and every 3 d thereafter for osmolarity, hematocrit, hemoglobin concentration, mean corpuscular hemoglobin content, glucose, cortisol, and the electrolytes Cl - Na+, K+ and Ca+. The most significant perturbations to blood chemistry (P < 0.05) occurred within 24 h of initial transfer from the recirculating to flow-thru seawater systems, suggesting an osmoregulatory rather than handling or transfer related stress. Osmolarity, electrolyte, and hematological parameters fluctuated and then recovered to stable levels by day 8 in the flow-thru seawater system. However, unlike the initial transfer, successive movement to the coastal and then the open ocean net pens produced transient increases in both plasma cortisol and glucose levels, suggesting a high level of stress associated with extended flounder handling and transfer. [source] Chronic cystic ovarian disease in a Holstein cowAUSTRALIAN VETERINARY JOURNAL, Issue 1-2 2005AM PADULA Cystic ovarian follicles are commonly found during rectal examination of early postpartum dairy cows, usually presenting with anoestrus and occasionally nymphomania. Most cases self cure with time, or respond to exogenous hormonal treatment. This case report describes a refractory case in a Holstein cow in which a novel treatment approach was used. A gonadotrophin releasing hormone agonist implant was inserted for 180 d in an attempt to suppress pituitary gonadotrophin output, arrest abnormal ovarian follicle growth and prevent steroidogenesis. Frequent serial blood samples were collected before and after implant insertion to monitor changes in pulse release of luteinising hormone. Follow up ultrasound scans and blood samples were done to monitor ovarian structures; progesterone and oestradiol were collected at various times over the 180 d period. A normal, cycling herdmate was enrolled as a control. Prior to implant insertion, high frequency and low amplitude luteinising hormone pulses were detected in the cystic cow. Insertion was followed by a sustained surge in the release of luteinising hormone in both cows, but ovulation was not induced in the cystic cow. Plasma oestradiol levels remained consistently elevated and signs of oestrous behaviour were observed. Long term gonadotrophin releasing hormone agonist treatment failed to suppress either ovarian steroid production or cause regression of the cysts by 180 d. [source] | |||||||||||||