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NAD+-Dependent 15-Hydroxyprostaglandin Dehydrogenase from Swine Kidney: Characterization and Kinetic Mechanism
Cytoplasmic 15-hydroxyprostaglandin dehydrogenase from swine kidney was purified to specific activity of 1.2 U per mg protein, by chromatographic techniques. Native molecular weight of enzyme was estimated at 45,000. Enzyme was inhibited by sulfhydryls, diuretics, and various fatty acids. Substrate studies indicated NAD+ specificity and ability to catabolize prostaglandins, except prostaglandin B and thromboxane B. Initial velocity studies gave intersecting plots conforming to a sequential mechanism. 15-keto-prostaglandin exhibited linear noncompetitive production inhibition with respect to either prostaglandin or NAD+; NAD yielded linear competitive production inhibition with respect to NADH. Results, and those of dead-end inhibition and alternated substrate studies, are consistent with an ordered Bi-Bi mechanism: NAD+ is added first, then prostaglandin; then 15-keto-rostaglandin is released, then NADH
Comparison of laparoscopic versus open surgery in a three-stage operation for obstructive left-sided colorectal cancer
AbstractBackgroundTreatment for obstructive left-sided colorectal cancer (OLCC) typically consists of a three-staged procedure. During the first stage, the obstruction is managed with diversion colostomy. Traditionally in the second stage, we perform open resection for the primary tumor. In this study, we evaluated the feasibility of laparoscopic resection of OLCC with diversion colostomy in terms of operative results and short-term outcomes.MethodsA total of 20 patients underwent laparoscopic resection for OLCC (study group), 48 patients underwent open resection for OLCC (control group 1), and 53 patients underwent laparoscopic resection for non-OLCC (control group 2). Afterwards, results from the procedures were obtained and clinical data were analyzed.ResultsThe operative time was significantly longer in the study group than in the control group 1 (153 minutes vs. 126 minutes, p = 0.041), and the length of hospitalization was shorter in the study group than in the control group 1 (5.3 days vs. 7.6 days, p = 0.032). Regarding the operative results and short-term outcomes, there were no significant differences between the study group and control group 2. Colostomy retraction was a specific morbidity which occurred in two patients of the study group.ConclusionLaparoscopic resection of OLCC with diversion colostomy is feasible. Abdominal cavity adhesion is only limited. We strongly recommend that laparoscopic resection should be performed at least 2 weeks after diversion colostomy, and the plastic rod should be left in place during the pneumoperitoneum to reduce the risk of colostomy retraction
Direct Determination of ECD in ECD Kit: A Solid Sample Quantitation Method for Active Pharmaceutical Ingredient in Drug Product
Technetium-99m ethyl
cysteinate dimer (Tc-99m-ECD) is an essential
imaging agent used in evaluating the regional
cerebral blood flow in patients with
cerebrovascular diseases. Determination of
active pharmaceutical ingredient, that is,
L-Cysteine, N, NâČ-1,2-ethanediylbis-, diethyl ester, dihydrochloride (ECD) in ECD Kit is a relevant requirement for the pharmaceutical
quality control in processes of mass fabrication. We here
presented a direct solid sample determination method of ECD in ECD
Kit without sample dissolution to avoid the rapid degradation of
ECD. An elemental analyzer equipped with a nondispersive infrared
detector and a calibration curve of coal standard was used for the
quantitation of sulfur in ECD Kit. No significant matrix effect
was found. The peak area of coal standard against the amount of
sulfur was linear over the range of 0.03â0.10âmg,
with a correlation coefficient (r) of 0.9993. Method validation
parameters were achieved to demonstrate the potential of this
method
Interfacial Properties of Polyethylene Glycol/Vinyltriethoxysilane (PEG/VTES) Copolymers and their Application to Stain Resistance
In this study, polyethylene glycol (PEG) and vinyltriethoxysilane (VTES) were used in different proportions to produce a series of PEGâVTES copolymers. The copolymer molecular structures were confirmed by FTIR spectroscopy. In addition, their surface activities were evaluated by evaluating the surface tension, contact angle, and foaming properties. The results showed that these surfactants exhibited excellent surface activities and wetting power, as well as low foaming. Consequently, the application of a series of PEG/VTES copolymers can make cotton fabrics stain resistant
Strategically examining the full-genome of dengue virus type 3 in clinical isolates reveals its mutation spectra
BACKGROUND: Previous studies presented the quasispecies spectrum of the envelope region of dengue virus type 3 (DENV-3) from either clinical specimens or field-caught mosquitoes. However, the extent of sequence variation among full genomic sequences of DENV within infected individuals remains largely unknown. RESULTS: Instead of arbitrarily choosing one genomic region in this study, the full genomic consensus sequences of six DENV-3 isolates were used to locate four genomic regions that had a higher potential of sequence heterogeneity at capsid-premembrane (C-prM), envelope (E), nonstructural protein 3 (NS3), and NS5. The extentof sequence heterogeneity revealed by clonal sequencing was genomic region-dependent, whereas the NS3 and NS5 had lower sequence heterogeneity than C-prM and E. Interestingly, the Phylogenetic Analysis by Maximum Likelihood program (PAML) analysis supported that the domain III of E region, the most heterogeneous region analyzed, was under the influence of positive selection. CONCLUSION: This study confirmed previous reports that the most heterogeneous region of the dengue viral genome resided at the envelope region, of which the domain III was under positive selection pressure. Further studies will need to address the influence of these mutations on the overall fitness in different hosts (i.e., mosquito and human) during dengue viral transmission
Climatology and Change of Extreme Precipitation Events in Taiwan Based on Weather Types
Taiwan\u27s most significant natural hazards are caused by hydrological extremes resulting from excessive precipitation. The threat of extreme precipitation is posed by several different types of weather patterns that affect Taiwan. This study examined the biâdecadal changes in rainfall by defining an extreme precipitation occurrence (EPO) for a range of event durations from 1 to 24âhr. Three major weather types affecting EPO in Taiwan were identified from 1993 to 2015: the front type consisting of either a frontal zone or convective systems developing with an apparent Meiyu cloudband, diurnal rainfall events when no apparent synoptic features are present, and a tropical cyclone (TC) type according to the maximum sustained wind radius of a TC. Results show that TCâtype events have the greatest overall contribution to EPO at longer (\u3e6 hr) durations. Diurnal/afternoon convection events contribute most to the shorter (\u3c3 hr) duration EPO, while frontal/Meiyu systems prevail in the medium (3â6 hr) duration. EPO of almost all durations have experienced an increase, with the 3â and 12âhr EPO having increased by 4.6 days each over the 23âyears. However, apparent decadalâscale variability exists in these EPO associated with the decreasing tendency of EPO after the midâ2000s, particularly the longer duration (\u3e6 hr) EPO associated with the TCâtype events in summer. The distinction between EPO trends for the entire island of Taiwan and for the Taipei metropolitan area alone (northern Taiwan, population of 7 million) were compared, and an intriguing interannual variation is reported in the TCâtype EPO associated with the TC season 1âyear to a year and half just before an El NiñoâSouthern Oscillation event. The analysis here provides refined statistical distributions of extreme rainfall, and these can contribute to the revision of governmental definitions for weather disasters that are used in mitigation and response strategies
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