Clinical applications of retrograde autologous priming in cardiopulmonary bypass in pediatric cardiac surgery.

Retrograde autologous priming (RAP) has been routinely applied in cardiac pediatric cardiopulmonary bypass (CPB). However, this technique is performed in pediatric patients weighing more than 20 kg, and research about its application in pediatric patients weighing less than 20 kg is still scarce. This study explored the clinical application of RAP in CPB in pediatric patients undergoing cardiac surgery. Sixty pediatric patients scheduled for cardiac surgery were randomly divided into control and experimental groups. The experimental group was treated with CPB using RAP, while the control group was treated with conventional CPB (priming with suspended red blood cells, plasma and albumin). The hematocrit (Hct) and lactate (Lac) levels at different perioperative time-points, mechanical ventilation time, hospitalization duration, and intraoperative and postoperative blood usage were recorded. Results showed that Hct levels at 15 min after CPB beginning (T2) and at CPB end (T3), and number of intraoperative blood transfusions were significantly lower in the experimental group (P<0.05). There were no significant differences in CPB time, aortic blocking time, T2-Lac value or T3-Lac between the two groups (P>0.05). Postoperatively, there were no significant differences in Hct (2 h after surgery), mechanical ventilation time, intensive care unit time, or postoperative blood transfusion between two groups (P>0.05). RAP can effectively reduce the hemodilution when using less or not using any banked blood, while meeting the intraoperative perfusion conditions, and decreasing the perioperative blood transfusion volume in pediatric patients.

Relaxation dynamics of a single DNA molecule.

The relaxation of a single DNA molecule is studied. The experimental system consists of optical tweezers and a micron-sized bead that is tethered to the bottom of the sample by a single double-stranded DNA molecule. The bead slows down the DNA relaxation from a strongly stretched configuration such that it is passing through stretched equilibrium states. This allows for a theoretical description of the relaxation trajectory, which is in good agreement with experiment.

Effect of verapamil on acute coxsackievirus B3 murine myocarditis.

The effect of verapamil (Ver) on CVB3 murine myocarditis was investigated. It was found that Ver could aggravate the myocardial inflammation, increase the viral replication in myocardium, and raise mortality in mice with viral myocarditis when the drug was injected within the first 6 days after the CVB3 inoculation.

[Studies on the synthesis and activities of RGD related peptides].

In the binding of Fgn to GP IIb/IIIa, RGD is the key sequence. In the present paper, RGDS, RGDV and RGDF were synthesized by use of solution method. Bioassay indicated that the C-terminal amino acid residues were very important for their antithrombosis effects. Conformational studies showed that their antithrombosis potency may depend on their total energies. The observation of their vasodilation effects suggests that this kind of function is worthy to be further studied.

Study on the mechanism of interferon action (XI)--Effect of pppA2'p5'A on the level of cAMP and cGMP in macrophages.

In this paper, the increase of cellular cAMP and cGMP levels in macrophages induced by ppA2'p5' A2'p5'A (briefly 2'-5'P3A3) is first reported. The optimal concentration of 2'-5' P3A3 for the elevation of cellular cGMP to the highest level is 10(-7)-10(-6) mol/L, while that for cAMP is 10(-7) mol/L. The time for cGMP to reach its peak value is 15 min and that for cAMP is 2 h, when the cells are treated with 2'-5' P3A3 at 10(-7) mol/L, which is the optimal concentration for developing biological effect of macrophages (phagocytosis). These results suggest that cGMP and cAMP may be related to, or may be the mediators for, 2'-5'P3A3 action.

Development of an alternating integrator for magnetic measurements for experimental advanced superconducting tokamak.

A high-performance integrator is one of the key electronic devices for reliably controlling plasma in the experimental advanced superconducting tokamak for long pulse operation. We once designed an integrator system of real-time drift compensation, which has a low integration drift. However, it is not feasible for really continuous operations due to capacitive leakage error and nonlinearity error. To solve the above-mentioned problems, this paper presents a new alternating integrator. In the new integrator, the integrator system of real-time drift compensation is adopted as one integral cell while two such integral cells work alternately. To achieve the alternate function, a Field Programmable Gate Array built in the digitizer is utilized. The performance test shows that the developed integrator with the integration time constant of 20 ms has a low integration drift (<15 mV) for 1000 s.

Clinical applications of retrograde autologous priming in cardiopulmonary bypass in pediatric cardiac surgery

Retrograde autologous priming (RAP) has been routinely applied in cardiac pediatric cardiopulmonary bypass (CPB). However, this technique is performed in pediatric patients weighing more than 20 kg, and research about its application in pediatric patients weighing less than 20 kg is still scarce. This study explored the clinical application of RAP in CPB in pediatric patients undergoing cardiac surgery. Sixty pediatric patients scheduled for cardiac surgery were randomly divided into control and experimental groups. The experimental group was treated with CPB using RAP, while the control group was treated with conventional CPB (priming with suspended red blood cells, plasma and albumin). The hematocrit (Hct) and lactate (Lac) levels at different perioperative time-points, mechanical ventilation time, hospitalization duration, and intraoperative and postoperative blood usage were recorded. Results showed that Hct levels at 15 min after CPB beginning (T2) and at CPB end (T3), and number of intraoperative blood transfusions were significantly lower in the experimental group (P<0.05). There were no significant differences in CPB time, aortic blocking time, T2-Lac value or T3-Lac between the two groups (P>0.05). Postoperatively, there were no significant differences in Hct (2 h after surgery), mechanical ventilation time, intensive care unit time, or postoperative blood transfusion between two groups (P>0.05). RAP can effectively reduce the hemodilution when using less or not using any banked blood, while meeting the intraoperative perfusion conditions, and decreasing the perioperative blood transfusion volume in pediatric patients.

Dose estimation by chromosome aberration analysis and micronucleus assays in victims accidentally exposed to (60)Co radiation.

The objective of this study was to assess the radiation exposure levels in victims of a (60)Co radiation accident using chromosome aberration analysis and the micronucleus assay. Peripheral blood samples were collected from three victims exposed to (60)Co 10 days after the accident and were used for the chromosome aberration and micronucleus assays. After in vitro culture of the lymphocytes, the frequencies of dicentric chromosomes and rings (dic+r) and the numbers of cytokinesis blocking micronuclei (CBMN) in the first mitotic division were determined and used to estimate radiation dosimetry. The Poisson distribution of the frequency of dic+r in lymphocytes was used to assess the uniformity of the exposure to (60)Co radiation. Based on the frequency of dic+r in lymphocytes, estimates of radiation exposure of the three victims were 5.61 Gy (A), 2.48 Gy (B) and 2.68 Gy (C). The values were estimated based on the frequencies of CBMN, which were 5.45 Gy (A), 2.78 Gy (B) and 2.84 Gy (C). The estimated radiation dosimetry demonstrated a critical role in estimating the radiation dose and facilitating an accurate clinical diagnosis. Furthermore, the frequencies of dir+r in victims A and B deviated significantly from a normal Poisson distribution. Chromosome aberration analysis offers a reliable means for estimating biological exposure to radiation. In the present study, the micronucleus assay demonstrated a high correlation with the chromosome aberration analysis in determining the radiation dosimetry 10 days after radiation exposure.

Protective effects of Ginkgo biloba extract on gastric mucosa.

AIM: To study the protective effects of Ginkgo biloba extract (GbE) on gastric mucosa. METHODS: By means of restaint-cold stress (RCS) in rats and 100% ethanol gavage in mice, the index of gastric mucosal injury was evaluated. The gastric juice was collected using pyloric ligation, and the volume and acidity of juice, and activity of pepsin were determined. The content of malondialdehyde (MDA) was measured by thiobarbituric acid (TBA) method. RESULTS: GbE (25, 50, and 100 mg/kg, bid x 5 d, ig) inhibited dose-dependently the gastric mucosal injury induced by RCS and 100% ethanol gavage. The index of gastric mucosal injury after RCS in groups pretreated with GbE was 58%, 43%, and 31% of control group respectively. The index of gastric mucosal injury induced by ethanol in groups pretreated with GbE was 62%, 36%, and 26% of the control group, respectively. And GbE enhanced the protective effects of cimetidine (Cim) on gastric mucosa. But it did not obviously influence the volume and acidity of gastric juice as well as the activity of pepsin. One hour after the administration of ig 100% ethanol, the contents of MDA in gastric mucosa and serum in mice increased (P < 0.01) vs the control group. But pretreatment with GbE (25, 50, and 100 mg/kg, ig) could inhibit this increase of MDA both in gastric mucosa and in serum. CONCLUSION: GbE had protective effects on gastric mucosa and GbE plus Cim possessed the synergism in the treatment of acute gastric mucosal lesions.

7S(1/2) ? 9S(1/2) two-photon spectroscopy of trapped francium.

We report on the spectroscopic measurement of the (210)Fr 9S(1/2) energy obtained by two-photon excitation of atoms confined and cooled in a magneto-optic trap. The resonant intermediate level 7P(3/2) is the upper state of the trapping transition. We have measured the energy difference between the 9S(1/2) state and the 7S(1/2) ground state to be 25 671.021 +/- 0.006 cm(-1).

Nonresonant third harmonic generation and the parametric process in Zn vapor.

Nonresonant third harmonic generation with tuning range between 157.0-158.8 nm and 210.4-214.0 nm in zinc vapor is reported. Using two-photon excitation of Zn 4s4d(1)D(2), 4s6s(1)S(0), and 4s6d(1)D(2) states, parametric processes with signal waves 213.8 nm, 159.0 nm, and 145.8 nm are also investigated.

Relaxation dynamics of semiflexible polymers.

We study the relaxation dynamics of a semiflexible chain by introducing a time-dependent tension. The chain has one of its ends attached to a large bead, and the other end is fixed. We focus on the initial relaxation of the chain that is initially strongly stretched. Using a tension that is self-consistently determined, we obtain the evolution of the end-to-end distance with no free parameters. Our results are in good agreement with single molecule experiments on double stranded DNA.