A new bubble oxygenator (OCVC oxygenator): Development and clinical application

A new bubble oxygenator, designed for simple operation and clinical efficacy in intracardiac surgery, has been developed and clinically evaluated. This device is characterized by an oxygenating chamber with controllable blood-volume, integral heat exchanger and two-stage microfilter of gravity drainage system, an apparatus for creating and uniformly distributing oxygen bubbles, and construction materials of the device known to be minimally traumatic to the blood. Clinical experience in 132 infantile and pediatric open heart procedures has demonstrated its effectiveness as measured by embolic complications and simplicity in maintaining physiologic blood gas levels.     

Supracondylar Femoral Nail in the management of non-union of humeral shaft fractures

We reviewed seven patients with established non-union of a shaft of humerus fracture, treated by locked intramedullary nailing using the Intramedullary Supracondylar Nail (IMSC Nail; Smith & Nephew Richards, Memphis TN). The mean age of the patients was 65 years (range 48-78 years). Three of the fractures involved the proximal third of the diaphysis while the remaining four involved the middle third. Six of the original fractures were closed and one was an open fracture. The time interval between the original injury and final surgery averaged 9.3 months. All the nailings were done by the ante-grade approach with static locking. Six of the patients had closed nailing and one had open nailing with bone grafting. The mean follow-up was 8 months and osseous union was achieved in all seven cases at a mean of 5.6 months. We conclude that the Supracondylar Femoral Nail is a useful alternative implant in the management of non-union of fractures of the humeral shaft with wide medullary canals.     

Identification of BVT.2938 metabolites by LC/MS and LC/MS/MS after in vitro incubations with liver microsomes and hepatocytes

The metabolism of the 5HT2c agonist BVT.2938, 1-(3-{2-[(2-ethoxy-3-pyridinyl)oxy]ethoxy}-2-pyrazinyl)-2(R)-methylpiperazine, was studied in vitro by incubation with rat, monkey and human liver microsomes as well as cryopreserved hepatocytes, followed by liquid chromatography/mass spectrometry (LC/MS) and LC/MS/MS analysis on a quadrupole-time of flight mass spectrometer for structural elucidation. Deuterium exchange on column was used to differentiate between hydroxylation and N-oxidation. Liver microsomes were incubated in two different buffer systems with optimum conditions for cytochrome P450 activity or UDP-glucuronosyltransferase activity. The major phase I metabolites of BVT.2938 originated from O-deethylation of the pyridine ring, O-dealkylation of the ethylene bridge, pyrazine ring hydroxylation, hydroxylation of pyridine ring and piperazine ring N-hydroxylation. When a hydrogen carbonate buffer system was supplemented with UDPGA, the piperazine carbamoyl-glucuronide from the parent compound was identified together with several glucuronides of the phase I metabolites. The metabolite pattern in hepatocytes was similar to microsomes except that the sulphate at the N-position of the piperazine ring of BVT.2938 was identified, while the carbamoyl-glucuronide was missing. Excellent correlation was obtained between radioactivity detection and the chemiluminescent nitrogen detector when the nitrogen content of the analytes was taken into account.     

Foreperiod duration and motor preparation during childhood

To assess the role of brain-derived neurotrophic factor (BDNF) in nociceptive processing after chronic lateral spinal cord hemisection injury (SCI) at T13, we studied the effects of BDNF on evoked activity of dorsal horn wide dynamic range (WDR) neurons. Evoked responses of WDR cells (n=34 total) at L3–L5 were characterized electrophysiologically after spinal administration of vehicle, or BDNF (10 μg). In hemisected animals, application of BDNF to the surface of the cord resulted in reductions in evoked activity in 24 of 32 cells (75%), and enhancement of evoked activity in eight of 32 (25%) cells. Phosphate-buffered saline-receiving animals demonstrated evoked response rates of between 75 and 93 Hz, while BDNF(−) cells had evoked rates from between 20 and 41 Hz, and BDNF(+) activities were between 80 and 119 Hz, significant changes of 76 and 124%, respectively. Effects were bilateral and differences in sidedness were not observed. These results further implicate BDNF in nociceptive processing, but suggest a complex role after chronic SCI.     

Influence of gravity on radiographic contrast material-based measurements of regional blood flow distribution

RATIONALE AND OBJECTIVES: Radiographic measurement of regional blood flow distribution in the lungs is potentially biased because the contrast material used to track flow is denser than blood. The authors performed this study to evaluate the effect of gravity on flow estimates by using an experimental test phantom and numeric simulations. MATERIALS AND METHODS: Cross-sectionally uniform boluses of radiopaque contrast material were delivered at the upstream end of a horizontal inlet tube connected to a downstream axisymmetric bifuration attached to collecting tubing spirals. The phantom was imaged by using both planar angiography and dynamic multi-detector row computed tomography (CT) during the passage of the bolus through the phantom. The images were analyzed to determine the relative amounts of contrast material traveling through the top and bottom branches of the bifurcation by using varying Reynolds numbers and ratios of inlet tube volume to bolus volume. Numeric simulations of flow within a straight channeL with use of a dispersion operator intended to simulate settling of the bolus due to gravity, were performed under conditions representative of those in the experiments. RESULTS: When the plane of the bifurcation was vertical and actual flow through the two branches was equal, the fraction of contrast material passing through the downward-directed branch increased with decreasing Reynolds number and increasing inlet tube-bolus volume ratio. This occurred in both the experiments and the simulations. CONCLUSION: Because in the circulation Reynolds number decreases and pathway length increases with decreasing vessel diameter, the accuracy of regional flow measurements obtained with angiography or CT within the lungs may be limited by density differences between contrast material and blood.     

Performance of Web-based image distribution: client-oriented measurements

The aim of this study was to define a clinically suitable personal computer (PC) configuration for Web-based image distribution and to assess the influence of different hard- and software configurations on the performance. Through specially developed software the time-to-display (TTD) for various PC configurations was measured. Different processor speeds, random access memory (RAM), screen resolutions, graphic adapters, network speeds, operating systems and examination types (computed radiography, CT, MRI) were evaluated, providing more than half a million measurements. Processor speed was the most relevant factor for the TTD; doubling the speed halved the TTD. Under processor speeds of 350 MHz, TTD mostly remained above 5 s for 1 CR or 16 CT images. Here Windows NT with lossy compression were superior. Processor speeds of 350 MHz and over delivered TTD <5 s. In this case Windows 2000 and lossless compression were preferable. Screen resolutions above 1280×1024 pixels increased the TTD mainly for CR images. The RAM amount, network speed and graphic adapter did not have a significant influence. The minimum threshold for clinical routine is any standard off-the-shelf PC better than Pentium II 350 MHz, 128 MB RAM; hence, high-end PC hardware is not required.     

顶空气相色谱法测定化妆品中甲醇

目的：本文采用顶空气相色谱法测定化妆品中甲醇的含量.方法：用氢火焰离子化检测器检测.结果：化妆品中甲醇的最低浓度为1.5 mg/kg,在样品中加标量分别为20 mg和40 mg时,回收率为91.9%～95.2%,依本法取两份样品分别测6次,变异系数为1.6%～2.8%.结论：该方法具有简便、快速、灵敏度高、准确性好等优点.     

石榴皮中乌索酸和齐墩果酸含量的反相高效液相色谱测定

目的建立反相高效液相色谱法同时测定石榴皮中乌索酸和齐墩果酸的含量,并进行方法学考察。方法色谱柱为Kromasil C18分析柱(4.6 mm×250 mm,5μm),流动相为甲醇-水-磷酸(88∶12∶0.1),流速0.8 ml.min-1,光电二极管阵列检测器(PAD),检测波长210 nm,柱温28℃。结果在选定色谱条件下线性范围良好,乌索酸和齐墩果酸的样品加样回收率分别为99.3%和98.5%,RSD为2.20%和1.78%。结论方法测定快速,结果准确、可靠,可用于石榴皮中乌索酸和齐墩果酸含量的定量分析。     

HPLC-ELSD法测定青葙子中青葙苷A和青葙苷B的含量

目的:测定青葙子中青葙苷A和青葙苷B的含量. 方法:HPLC-ELSD法,色谱柱(4.6mm×250mm,5 μm),流动相为乙腈-0.1%冰乙酸水溶液梯度洗脱,以蒸发光散射检测器(ELSD)检测. 结果:青葙苷A在2.5～30.0 μg范围内与峰面积呈良好的线性关系,回收率为99.89%,RSD为1.85% (n=6);青葙苷B在1.25～15.0 μg范围内与峰面积呈良好的线性关系,回收率为98.98%,RSD为1.78% (n=6).8个市售青葙子样品中青葙苷A和青葙苷B的含量存在显著差异,分别在(0.051 2±0.001 6)%～(0.114 3±0.000 8)%和(0.010 9±0.001 9)%～(0.081 5±0.000 9)%范围内. 结论:本研究首次建立了用HPLC-ELSD法测定青葙子有效成分的方法,该方法定量准确、操作简便.     

Kidney and liver distribution of ochratoxin A in male and female F344 rats

The impact of age and gender on Ochratoxin A (OTA) distribution in kidney and liver were studied. OTA was quantified in kidney and liver of young and mature rats of both sexes. Data was fit simultaneously using the population approach with NONMEM program. Fed and fasted mature males showed a 30% decrease and an 11% increase in relative bioavailability, respectively, in comparison with the rest of the groups. The OTA concentrations reached in kidney and liver were very similar between both organs. The models that best fit to data were the ones that considered that distribution of OTA to kidney and liver occurs from the central compartment and that elimination occurs mainly from the liver compartment. The kinetic analysis revealed that both, the apparent volume of distribution of the central compartment (V/F) and the apparent volume of distribution of the liver and kidney compartments (V_L,K/F) increased significantly with body weight. Thus, the sex differences observed in organs distribution are a reflection of the differences in relative bioavailability observed in adult males, as a consequence of the fed and fasted conditions and to the significant higher body weight of mature males which directly affected the V/F and V_L,K/F.