Biomedical subjects
Publications and source records attributed to F Li.
The Rhizoma Atractylodis, Cortex Magnoliae Officinalis and Pericarpium Citri Reticulatae in Huoxiang-zhengqi Liquid were identified by TLC. The total contents of magnolol and honokiol were determined by HPLC to be no less than 1.9 mg/ml, with an average recovery of 104.4% and 103.3%, RSD 1.23% and 0.91% respectively.
This paper reports the characteristics of microscopic and physicochemical identifications, as well as the determination of amino acids and inorganic elements in Unguis Suillus of the crude drug Hog Nail of Sus scrofa domestica. The results show that the protein content of Unguis Suillus amounts to 80.65%. The amino acids in the drug consist of 7 essential amino acids and 9 nonessential amino acids. The main inorganic elements are Na, Mg, Al, Si, P, S, Cl, K, Ca, Fe and Zn.
Studies on the chemical constituents of Phyllanthus urinaria and its antiviral activity against hepatitis B virus were completed. Eleven compounds have been isolated. Two of them are new compounds methyl ester dehydrochebulic acid and methyl brevifolin carboxylate. Antiviral experiments on HBsAg in vitro and liver damage caused by CCl4 have shown that. Phyllanthus urinaria possesses antiviral activities against HBV.
Two kinds of Chinese mineral drug Limonitum (a special ore of Limonitum in egg type and a general ore of Limonitum) were identified. The results showed that the main chemical components and optical characters of the two drugs were similar, but there were considerable differences in properties, element contents and IR spectra.
The contents of the essential oil ferulic acid in different processed products of Rhizoma Chuanxiong were determined, and the changes of constituents in the essential oil before and after processing were compared. The results have provided a scientific basis for processing Rhizoma Chuanxiong.
OBJECTIVE: To search for new effective hypotensive components from the Chinese folk drug, the root of Pimpinella thellungiana. METHOD: A new compound was isolated from etheral extract of the drug by chromatographic method and identified by physical, chemical and spectroscopic methods. RESULT: The compound has been identified as 2-(1',2'-dihydroxy)propyl-4-methoxy phenol. CONCLUSION: The compound was obtained from the root of P. thellungiana for the first time.
OBJECTIVE: To determine if the bile salt induces hepatocyte apoptosis in vitro. METHOD: Hepatocytes were isolated by in situ collagenase perfusion and plated in 6 well flat bottom with DMEM/F12, 0.5 micro/ml insulin. Two hours later, glycochenodeoxcholate (GCDC) 25, 50, 100, 200, 300 micromol was added and cells evaluated by DNA-PI staining FACS and terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL) 3, 6, 9, 12, 18, 20, 24 hours later. Agarose gel electrophoresis of DNA extracted from hepatocytes after incubation with GCDC using various experimental conditions. RESULT: The hepatocytes treated with GCDC have a high apoptotic rate as compared with the controls. 100 micromol GCDC treated 24 hours, nearly 61.81% of hepatocytes were apoptotic by FACS evaluation. The TUNEL showed that apoptotic hepatocytes had less cell volume and stained with brown by Biotin-11-dUTP. DNA ladder of bile-salt treated hepatocytes were shown in agarose gel electrophoresis. CONCLUSION: The mechanism of hepatic injury during obstructive jaundice is related to bile salt caused hepatocyte apoptosis.
OBJECTIVE: To evaluate transcranial magnetic stimulation motor evoked potential (TMS-MEP) in the diagnosis of spinal cord injury. METHOD: 56 patients with injury of the spinal cord and cauda equina were examined using TMS-MEP and followed up. RESULT: In 21 patients with complete paralysis, TMS-MEP of bilateral tibialis anterior and gastrocnemius disappeared and paralysis did not recover. Abnormal was noted TMS-MEP and paralysis not recovered in 2 patients with injury of conus medullaris and cauda equina. Incomplete paralysis occurred in 35 patients. TMS-MEPs of more than one muscle in every patient were recorded. Paralysis and TMS-MEPs recovered in different degree in the 33 patients, in which the strength was 0 class and TMS-MEPs were abnormal in 25 target muscles before operation whereas their strength obviously recovered or even normalized after operation except two muscles. CONCLUSION: TMS-MEP is an effective method for diagnosis and prognosis of spinal cord injury.
OBJECTIVE: To study the normal value and clinical applications of blink reflex. METHODS: Using the clinical electrodiagnostic techniques, the orbital nerve was stimulated to elicit the blink reflex. RESULTS: In 20(40 sides) normal subjects, two components (R1 and R2) had been documented. The latencies were about 10.1 ms for R1, 30.4 ms and 30.7 ms separately for R2 and R2'. In 30 patients with trigeminal and facial nerve diseases and acoustic neuromas, the latencies on the affected sides were apparently longer or the reflex disappeared (P < 0.01). CONCLUSION: This study indicates that the simple, harmless electrodiagnostic measurements are of value in the initial investigation of trigeminal and facial nerve diseases and acoustic neuroma.
Sprague Dawley rats were chosen to prepare immature and soft enamel tissue. The authors used a sequential dissociative extraction scheme in which the enamel matrix proteins were extracted first in guanidine HCl and then in guanidine HCl-EDTA, just as the method described by Termine, et al. The first step completely extracted amelogenins and the second step got enamelin. These two groups of protein were further purified by Sephadex-G200 gel filtration chromatography and analysed by polyacrylamide gel electrophoresis. The results showed: amelogenins were resolved into three fractions eluted from the column, and expressed as A1, A2, A3, respectively. The main fraction A1, which had a molecular weight range from 18 kD to 29 kD, had a main protein band of 23 kD when estimated by SDS-PAGE. Enamelin was eluted into two fractions called E1 and E2. The main fraction E1 had a single band of 44 kD on the SDS-PAGE gel. PAGE showed that amelogenins had many subunits. The authors also observed that the amelogenins would aggregate and precipitate reversibly when pH value, ionic strength or protein concentration changed.
AIM: To study the sensitivity and specificity of nested polymerase chain reaction for detection of Plasmodium vivax in infected mosquitoes. METHODS: Two pairs of primers specific to small subunit ribosomal DNA of P. vivax were used to amplify the specific SSUrDNA 121 bp fragment of P. vivax for detecting P. vivax-infected mosquitoes with nested PCR. RESULTS: Nested PCR could detect as few as 3 sporozoites in one mosquito or 1 infected mosquito mixed with a group of 99 normal ones. In contrast, no such specific 121 bp DNA band was detected in P. falciparum, P. cynomolgi, P. yoelii yoelii infected samples, nor in normal mosquito. CONCLUSION: The nested PCR technique we established showed high sensitivity and specificity.
AIM: To observe the effect of dihydro qinghaosu (DQHS) on the development of Plasmodium yoelii yoelii in Anopheles stephensi and to explore the possibility of whether DQHS has preventive effect against malaria. METHODS: Plasmodium yoelii yoelii-infected mice that had been administered with a single dose of different dosages (60 mg/kg, 120 mg/kg, 180 mg/kg and 240 mg/kg) of DQHS were exposed to mosquitoes to suck blood. The development of malaria parasites in the mosquitoes of the control group and the treated group were observed by light microscopy (LM) and transmission electron microscopy (TEM). RESULTS: DQHS exhibited certain inhibitory effect on the infectivity of gametocyte. The degree of inhibition was related to the developmental stages of gametocyte and the drug dosage. Immature gametocytes were more sensitive to DQHS than the mature gametocytes. With the increases in dosage, the positive rate and the density of oocyst and sporozoite decreased. However, the difference in the density of sporozoite between 180 mg/kg and 240 mg/kg treated groups was insignificant. TEM result showed damage of the membrane system and vacuolation in the cytoplasm of the oocysts (12-13 d) on mosquito midgut of 60 mg/kg 16 h treated group. The oocysts in the mosquitoes continued to develop after treated with 120 mg/kg of DQHS for 16 h on 3-day-instar. There was no significant difference (P > 0.05) in the density of oocyst and sporozoite between the control group and the treated group. CONCLUSION: DQHS can affect the infectivity of gametocyte and decrease the malaria transmission but cannot inhibit the sorogonic stage directly.
Plasmid-derived expression of the human CyPA in E. coli would make it possible to obtain ample protein quantities and to avoid difficult task of obtaining human tissues for protein purification. The cDNA encoding human CyPA from MT4 lymph cell line has been cloned and an expression vector (pET11/CyPA) has been constructed under control of the T7 promoter for efficient expression in E. coli. The recombinant CyPA is produced at 41% of total soluble cell protein, and showed the peptidyl-prodyl cis-trans isomerase activity.
A suicide plasmid pHNC3 which contains Tn5-luxAB was transferred into Rhizobium fredii HN01 by the help of pRK2013. Then Tn5-luxAB inserted on the genome of HN01 and gave luminescence activity. The luminescence colonies were picked up and the Eckhardt gel was performed for plasmids profile detection. The location of Tn5-luxAB on the genome was determined using the luxAB as probe. The colonies which were marked by Tn5-luxAB on the chromosome and different plasmids of HN01 were chosen for pot experiment, and a chromosome labelled strain HN01LC02 was detected by soil pot experiment. The detections included the nodulation occupancy and the luminescent nodules distribution on the root system formed by the luxAB-marked rhizobia.
In this paper, a facilitated cell model has been built to analyze the electromagnetic pulses (EMP) induced transmembrane potentials. The analysis shows that the athermal biological effects are caused by micropores on the membrance, not directly by transmembrane potentials. These micropores are enlarged by weak transient EMP and finally lead to membrane openings to make ions cross. The electroporation effects are used to explain the specific response of biological cells to transient EMP.
Four compounds were isolated from the roots of Pimpinella thellungiana Wolff., their structures were identified as palmitic acid(I), 4-propenylphenol(II), pinoresinol(III), 2-methyl-2-hydroxy-5-methoxy berzo(d) hydrofuran-3-one(IV) by physicochemical constants and spectral analysis (UV, IR, MS, 1HNMR, 13CNMR, 13C-1HCOSY, DEPT), IV of them is a new compound, Pharmacological tests showed IV has a hypotensive effect.
In this paper, 8 groups 16 kinds of mineral drugs were identified by fluorescence spectra. The results showed that the fluorescence spectra method in identifying mineral drugs is not only exact, sensitive, but also using little experimental materials and better repealability. This method can specially be used to identify the mineral drugs which have similar natrues and difficult to be distinguished from thim.
The recent development of the research of the spectral interferences and non-spectral interferences, and the application of correction methods for interferences in ICP-AES were reviewed.