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Biomedical subjects

Z M Zhou

Publications and source records attributed to Z M Zhou.

14 recordsLinked to original sources
PubMed2006

Three dimensional reconstruction of the pancreas based on the virtual Chinese human--female number 1.

OBJECTIVE: To study the three dimensional (3D) reconstruction and 3D visualisation of the pancreas and create anatomy of the digitalised visual pancreas so as to construct a concrete basis for virtual operation and surgical operation on pancreas. METHODS: The digital imaging data of pancreas, duodenum, common bile duct, arteries, and veins were obtained from the virtual Chinese human--female 1 (VCH-F1). The image data were investigated and 380 images ascertained of pancreas picked up from images numbers 2617 to 2996. Finally, the images from number 2574 to 3017 were adopted to segment and processed using ACDSee and Photoshop so as to reconstruct 3D pancreas digitally. The data of pancreatic surfaces were transformed into Visualization Toolkit (VTK). The GUI program written with VC+ was used to display this VTK file and realise 3D visualisation of the pancreas. RESULTS: 3D reconstruction and visualisation of the pancreas and the peri-pancreatic structures (the duodenum, the common bile duct,the inferior vena cava, the portal vein vessels, the aorta, the coeliac trunk vessels) was successful. The 3D and visualised pancreas manifested itself with its complete structure as well as its adjacency to other tissues. CONCLUSION: The 3D reconstruction and 3D visualisation of the pancreas based on the digital data of VCH-F1 produces a digitally visualised pancreas, which promises a novel method for virtual operation on the pancreas, clinical operation on the pancreas, and anatomy of 3D visualised pancreas.

Arteries↗
PubMed2004

Level set based auto segmentation of the tagged left ventricle MR images.

To facilitate automatic segmentation, we adopt SVM (Support Vector Machine) to localize the left ventricle, and the segmentation is then carried out with narrow band level set. The method of generating the narrow band is improved such that the time used is reduced. Based on the imaging characteristics of the tagged left ventricle MR images, BPV (block-pixel variation) and intensity comparability are introduced to improve the speed term of level set and to increase the precision of segmentation. Our method can perform the segmentation of the tagged left ventricle MR images accurately and automatically.

Heart Ventricles↗
PubMed2002

Expression of a novel reticulon-like gene in human testis.

Identification of genes that are specifically expressed in the adult testis or the fetal testis is important for the study of genes related to the development of the testis. In this study, a human testis cDNA microarray was established. PCR products of 9216 clones from a human testis cDNA library were dotted on a nylon membrane; mRNA from adult and fetal testes were purified and probes were prepared by a reverse transcription reaction with testis mRNA as template. The microarray was hybridized with probes of adult and fetal testes, and 96.8 and 95.4% of clones were positive, respectively. In total, 731 clones were differentially expressed: 592 were highly expressed in adult testis and 139 were highly expressed in fetal testis. Among these genes, a new reticulon (Rtn)-like gene was detected and named Rtn-T. Rtn-T was highly expressed in adult human testis. The cDNA of Rtn-T contains 3491 bp and the putative protein had 968 amino acids. This protein is homologous to the six known members of the Rtn family (KIAA0886, Rtn xL, reticulon 4a, Nogo-A, Nogo-A short form, and brain my043) but was different at the 5' end. All homologues originate from one gene, and result from both different promotor regions and different splicing. Rtn-T lacks the first exon and contains a second exon that is lacking in the other homologues. Rtn-T is shorter than KIAA0886, Rtn xL, reticulon 4a and Nogo-A, but longer than the Nogo-A short form and brain my043. Sequence analysis showed that Rtn-T protein has two hydrophobic regions that may be membrane-spanning domains. Expression profiles showed that Rtn-T is specifically and strongly expressed in testis. The results of the present study indicate that the Rtn-T gene is differentially expressed in adult and fetal testes and encodes a membrane protein that may have a function in testis development.

Adult↗
PubMed2001

Determination of 14 chemical constituents in the traditional Chinese medicinal preparation Huangqin-Tang by high performance liquid chromatography.

The high performance liquid chromatographic (HPLC) method for the identification and determination of baicalin (BG), wogonoside (WG), oroxylin-A-glucoside (OG), baicalein (B), wogonin (W), orxylin-A (O), paeoniflorin (PF), glycyrrhizic acid (GL), glycyrrhetinic acid (GA), liquiritin (LG), isoliquirition (ILG), liquiritigenin (L), isoliquiritigenin (IL) and ononin (ON) in Huangqin-Tang [Chinese characters: see text] was established. The samples were separated with a Wakosil C18 column (4.6 x 150 mm) by linear gradient elution using A (MeOH-HAC 100:1, v/v)-B (Water-HAC 100:1, v/v) (0 min, 30:70; 15 min, 40:60; 30 min, 60:40; 45 min, 80:20; 60 min, 100:0) as the mobile phase at a flow-rate of 1.0 ml/min. The detection was by diode-array UV/Vis detector (DAD), and the wavelength was set at the range of 200-400 nm. Satisfactory results were obtained within 60 min for the simultaneous determination of the 14 constituents. The repeatability (RSD) of the method was generally less than 2% (n=5, interday and intraday). The recovery of BG was 96.9+/-1.71, WG was 98.9+/-2.99, PF was 99.7+/-0.52, LG was 95.3+/-2.67, GL was 96.7+/-3.44, and GA was 94.8+/-4.16, respectively.

Chromatography, High Pressure Liquid↗
PubMed2001

Extraction kinetics of phenol with N, N-di (1-methyl-heptyl) acetamide-kerosene using hollow fiber membrane extractor.

Extraction kinetics of phenol with N,N-di(1-methyl-heptyl) acetamide-kerosene using hollow fiber membrane extractor has been studied. The rate regularities and kinetic types of forward and backward extraction were obtained respectively by determining the forward and backward extraction rate under various experimental conditions. The mass transfer mechanism was discussed. Both the forward and backward extraction of phenol might be controlled by diffusion processes, and the diffusion resistance for both forward and backward extraction mainly exists in aqueous phase. In addition, ways to optimize the extraction process of phenol were discussed as well.

Acetamides↗
PubMed2000

Spatial-temporal correlations in the process to self-organized criticality.

A different type of spatial-temporal correlation in the process approaching the self-organized criticality is investigated for the two simple models for biological evolution. The changed behaviors of the position with minimum barrier are shown to be quantitatively different in the two models. Different results of the correlation are given for the two models. We argue that the correlation can be used, together with the power-law distributions, as criteria for self-organized criticality.

Biological Evolution↗
PubMed1998

Effects of aluminum potassium sulfate on learning, memory, and cholinergic system in mice.

AIM: To study the relationship between aluminum potassium sulfate (APS) and memory deficits of mice. METHODS: 30, 60, or 90 d after the mice were given daily APS i.g., the step-through latency (STL) was determined with a passive avoidance task. Aluminum (Al) contents in brain and blood were assayed with atomic absorption spectrophotometry. Acetylcholine (ACh) content in brain was determined with chemiluminescent method and choline acetyltransferase (ChAT) activity was measured radiochemically. RESULTS: APS 1 g.kg-1 increased blood-Al only after 30 d. After 60 d, STL, ACh content and ChAT activity decreased by 46.4%, 8.5%, and 22.6%, respectively. These parameters decreased by 50%, 11.1%, and 27.8%, respectively, with increased Al in blood and brain, after 90 d. APS 0.25 g.kg-1 had no effects on mice except blood-Al. In ethylcholine mustard aziridium chloride (AF64A) treated mice, APS 1 g.kg-1 only increased blood and brain-Al. CONCLUSION: The intake of APS 1 g.kg-1.d-1 for 60 d induced learning and memory deficits in mice.

Acetylcholine↗
PubMed1991

Rat ribophorin II: molecular cloning and chromosomal localization of a highly conserved transmembrane glycoprotein of the rough endoplasmic reticulum.

We report here the complete nucleotide sequence of rat ribophorin II. The predicted amino acid sequence is highly homologous to the corresponding human protein and consists of 631 amino acid residues, including a 22 amino acid N-terminal cleavable signal sequence, and a single 23 amino acid putative transmembrane domain. Northern blot analysis reveals a single -2.4 kb message expressed in a number of rat cell lines and in adult liver. The gene was mapped to mouse chromosome 2, close to the Src proto-oncogene.

Alleles↗
PubMed1987

Analysis of artesunic acid and dihydroqinghaosu in blood by high-performance liquid chromatography with reductive electrochemical detection.

A new high-performance liquid chromatography (HPLC) method using reductive electrochemical detection has been developed for the analysis of the antimalarial drugs artesunic acid (ARTS) and dihydroqinghaosu (DQHS) in blood. Presently, this method has been validated to 4 micrograms/ml for ARTS and 200 ng/ml for DQHS. Pharmacokinetic studies in the rabbit show that after intravenous administration (100 mg/kg) ARTS is metabolized rapidly to DQHS and has a t1/2 of 1.7 min in blood. DQHS data were fit to non-linear regression models consisting of the sum of two exponential terms. For phases 1 and 2, t1/2 values of 3.0 +/- 0.4 and 29 +/- 2 min were calculated, respectively. In vitro studies in which ARTS was incubated with blood from various species show that rabbit blood hydrolyzes ARTS at a much greater rate than rat or human blood. Incubation of ARTS with rabbit blood in the presence or absence of diisopropylfluorophosphate suggested that this hydrolysis reaction is catalyzed by plasma and red blood cell esterases. These results suggest that future pharmacokinetic studies in both animals and man should focus on the measurement of DQHS rather than ARTS.

Animals↗
PubMed1987

Determination of artemether in plasma and whole blood using HPLC with flow-through polarographic detection.

An HPLC method with polarographic detection for the trace determination of artemether in plasma and whole blood was developed and applied to pharmacokinetic and clinical pharmacological studies. The method showed high sensitivity and selectivity because of the easy reduction of the peroxide linkage of artemether at the mercury drop electrode. The detection limit was 10 ng and the detector response was linear over the range of 10 ng to 1 microgram artemether injected onto the column. The largest relative standard deviation of 10 replicate measurements of standard solutions (concentrations of 10 ng/mL-1 microgram/mL) was 8%. The recovery from whole blood and plasma of added drug (concentrations of 15-480 ng/mL) was 71-100%.

Animals↗