Biomedical subjects

Z M Luo

Publications and source records attributed to Z M Luo.

11 recordsLinked to original sources

PubMed2000

[Chemical synthesis and characterization of R20A-HWTX-I, a mutant of huwentoxin-I with single residue replacement].

Huwentoxin-I (HWTX-I) is a polypeptide neurotoxin purified from the venom of the spider Selenocosmia huwena. R20A-HWTX-I, a mutant of HWTX-I in which the Arg was replaced by Ala, was synthesized on solid support by using Fmoc chemistry. The synthetic mutant was oxidatively renatured in glutathione-containing buffer, and then isolated by reversed phase and specially designed ion-exchange HPLC. The chemical structure of R20A-HWTX-I was confirmed by amino acid analysis, Edman degradation and MALDI-TOF mass analysis. Physiological experiment showed that the replacement of R20 by a decreased the bioactivity of the HWTX-I by 92%, indicating that R20 is a key residue closely related to the bioactivity of the HWTX-I.

Animals↗

PubMed1997

A fast numerical algorithm for electron mean energy calculation in radiation therapy.

A numerical algorithm for calculating the mean energy of radiotherapy electron beams has been developed. This algorithm is fast and accurate which makes it suitable for routine clinical use. First, a Gaussian distribution of the electron energy spectrum is derived from the linear Boltzmann equation. Based on this Gaussian spectrum, and after introducing a correction to the CSDA mean energy, a recursive-iterative algorithm for the mean energy calculation is developed. The multiple-scattering correction is taken into account using Yang's pathlength distribution theory. Numerical results of the present algorithm are compared with the results obtained through Monte Carlo simulation as well as Harder's formula. Good agreement with Monte Carlo simulation is achieved. Also the new algorithm is much more accurate than the commonly-used empirical formula of Harder.

Algorithms↗

PubMed1992

[Serum beta 2-microglobulin determination in nasopharyngeal carcinoma patients. An analysis of 139 cases].

Serum beta 2-microglobulin (beta 2-M) was determined in normal adults, patients with chronic nasopharyngeal inflammation and nasopharyngeal carcinoma (NPC) by the radioimmunoassay (RIA). The mean value in normal adults was 2023.85 +/- 454.32 micrograms/L, that in patients with chronic nasopharyngeal inflammation was 3294.65 +/- 1320.89 micrograms/L. The mean value in patients with NPC was significantly higher than those in patients with chronic nasopharyngeal inflammation and normal adults (P < 0.01). But there was not significant difference between mean values of patients with chronic nasopharyngeal inflammation and normal adults (P > 0.05). It is suggested that the RIA of beta 2-M is a useful assay in the diagnosis of NPC.

Adult↗

PubMed1990

[Inhibition of demand pacemakers by myopotentials and its clinical significance].

Unipolar demand pacemaker myopotential inhibition by 5 different provocative maneuvers was studied in 48 patients with stable pacing rhythm out of 82 patients with unipolar pacemakers from 3 manufacturers implanted over the right pectoralis major to evaluate the incidence of inhibiting phenomenon and its clinical significance. Transient pacing inhibition occurred in 19 (39.6%) of the 48 patients. Among them 3 (30.0%) of 10 patients with Model 28 (EDWARDS), 6 (31.6%) of 19 patients with Model 30 (EDWARDS), 10 (71.4%) of 14 patients with Model 7550 (ELAMEDICAL), and none of the 5 patients with Model P101 (QINMING). The effective maneuvers were the right hand-to-left shoulder press (63.2% positivity), the uprising from a supine position (21.0% positivity) and the hand-to-hand press (15.8% positivity). No pacemaker myopotential inhibition had been induced by Valsalva maneuver and the left hand-to-right shoulder press. 19 patients with positive myopotential inhibition had pauses of pacemaker function lasting from 1.2 to 3.9 seconds, 13 of them with pauses more than 2 seconds. Of all 48 patients, 9 (18.7%) experienced symptoms of cerebral ischemia due to pacemaker myopotential inhibition during test, among whom 8 had ventricular standstill more than 2 seconds. This showed a close relation between symptoms and duration of the pacing inhibition. The causes of the phenomenon and its prevention were briefly discussed.

Adult↗

PubMed1989

[Serum lipids and apolipoproteins AI, B100, CI and CII in patients with apoplexy].

Serum triglycerides, cholesterol, HDL-cholesterol and apolipoproteins (apo) AI, B100. CI and CII were determined and analyzed in 72 apoplectic patients and 64 age-matched normal subjects. Significantly increased triglycerides, low HDL-C and slightly decreased cholesterol levels were found in the apoplectics. Apo AI was slightly decreased and apo B100 slightly increased in the apoplectics compared with normal subjects. Apo CI and CII levels were significantly decreased in the apoplectics. The results are discussed.

Adult↗

PubMed1989

[Plasma CK-MB activity and QRS score in estimating acute myocardial infarct size].

Comparison of the peak value of plasma isoenzyme MB of creatine kinase (CK-MB) and the modified Selvester QRS score system from the standard 12-lead electrocardiogram in estimating acute myocardial infarct size and predicting hospital prognosis was performed in 52 patients with initial acute myocardial infarction (AMI). A correlation coefficient (C.C.) of 0.51 in all these patients was found. The C.C. in the patients with anterior AMI (n = 22, r = 0.64) is larger than that in inferior AMI (n = 30, r = 0.34). The prognostic value of the two methods are different. Peak CK-MB activity could predict hospital mortality and morbidity (serious arrhythmia or/and Killip AMI classification more than class III) for both anterior and inferior AMI; however, the QRS score system was significant only for anterior AMI. The clinical significance of a high ratio of peak CK-MB activity to QRS score was discussed briefly.

Adult↗

PubMed1987