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Biomedical subjects

Z M Wang

Publications and source records attributed to Z M Wang.

At least 37 records · Page 2Linked to original sources
PubMed2001

Environmental impact of radionuclide migration in groundwater from a low-intermediate level radioactive waste repository.

The radionuclide migration from a certain Chinese repository with low-intermediate level radioactive solid waste is studied. The migration in groundwater is analyzed and computed in detail. Under presumption of normal releasing, or the bottom of the repository has been marinated for one month with precipitation reaching 600 mm once and a 6 m aerated zone exists, a prediction for 7 radionuclides is conducted. It shows that the aerated zone is the primary barrier for migration. The migration for radionuclides 60Co, 137Cs, 90Sr, 63Ni, etc. will be retarded in it within 500 years. The concentration of 239Pu will be decreased by amount of 6 order. Only 3H and 14C can migrate through the aerated zone. The radionuclides that go through the aerated zone and enter the aquifer will exist in spring, stream and sea. Based on this, the intake dose by residents in different age group resulting from drinking contaminated spring water, eating seafood is calculated. The results showed that the impact of the repository to the key resident group is lower than the limit in national repository regulation standard. This complies with the repository management target.

Air↗
PubMed2001

[Preliminary studies on process and ultramicro-pulverization on pharmacodynamics of Leech].

OBJECTIVE: To compare pharmacodynamics of decoction and powder of Leech; To identify effect of pharmacodynamics of Leech with new methods of process and ultrmicro-pulverization. METHOD: The size of ultramicor-powder of Leech and new method processed Leech is determined by BT-1500 size distributive instrument. It is compared that the pharmacodynamics of Leech decoction and powder as well as ultramicro-powder with new method processed of 1/2 decoction dose by anticoagulation and antithrombus action of mice. The safety of different samples is identified. RESULT: The pharmacodynamics of samples is as ultramicro-powder of Leech with new method processed > ultrmicro-powder of Leech > powder of Leech > decoction of Leech. CONCLUSION: The ultramicro-powder of Leech with new method processed has better pharmacodynamic effect and the smell of Leech is improved.

Animals↗
PubMed2001

[Studies on chemical constitutents from Penthorum chinense Pursh].

OBJECTIVE: To study the chemical constituents of Penthorum chinense. METHOD: Silica gel and macroporous resin were used as adsorbent for isolation and purification. The chemical structures were elucidated by spectral analysis and chemical methods. RESULT: Three compounds were isolated from the water-extract of P. chinense. The structures were identified as 5-hydroxy-flavanone-7-O-beta-D-glucoside (I), 2,4,6-trihydroxybenzoic acid (II) and quercetin(III), respectively. CONCLUSION: Compounds I and II were isolated from this plant for the first time.

Flavanones↗
PubMed2001

[Effects of anti-idiotypic antibody NP30 on modulation of egg granuloma formation and hepatic fibrosis of schistosomiasis].

OBJECTIVE: To study the effects of the monoclonal anti-idiotypic antibody NP30 active immunization on egg granuloma formation and hepatic fibrosis in Schistosoma japonicum infection. METHODS: ICR mice were actively immunized with NP30 100 micrograms x 3 i.p. every 10 days while the mice in control group were injected with SP2/0 ascites i.p. simultaneously. After cercariae challenging, the mice were killed at the 4th, 8th, 12th, 16th, 20th and 24th week, respectively. Mouse livers were removed and stained histochemically with VG and subjected to immunohistochemical assay of collagen type I, III and fibronectin(FN). The volume of egg granulomas and the content of collagen type I, III and FN were determined quantitatively by NYD-1000 Image Analysis System. RESULTS: The volume of egg granulomas in NP30 immunized group was much smaller than that of control group from the 12th week after cercariae challenge. The cellular components of egg granulomas in NP30 immunized group were significantly different from those of the control group, exhibiting two types of atypical egg granulomas were found. VG stain revealed that the average optical density of collagen in hepatic granulomas of experimental group was lower than that of control group. Immunohistochemical assay revealed that the contents of collagen type I, III and fibronectin in egg granulomas of experimental group were lower than those of control group. CONCLUSION: NP30 vaccination may induce both cellular and humoral protective immunity to modulate egg granulomas and suppress liver fibrosis of schistosomiasis japonica.

Animals↗
PubMed2001

[Analysis and detection of abnormal ECG signal: ventricular tachycardia and fibrillation].

This paper, utilizing signal power spectrum and L-Z complexity measure, analyzes the abnormal ECG: ventricular tachycardia (VT) and ventricular fibrillation (VF). And on the base of linear and nonlinear dynamics, the paper forwards a new definition of information complexity rate, deduces some relative properties and applies it to complexity analysis in irregular ECG. By means of biological experiments and computer simulations, the reasonability of information complexity and complexity rate is confirmed. At last, objective analysis and explanations of the mechanism of VT and VF are reported. The results indicate: with the help of power spectrum, complexity measure and complexity rate, the recognition of VT and VF can attain 100%.

Algorithms↗
PubMed2001

[Study on the structure of epimerides of cycloclausenamide].

AIM: To study the structures of the epimerides of cycloclausenamide. METHODS: The structures of compound I, extracted from Clausena lansium (Lour.) Skeels, and synthesized compound III were determined by single crystal X-ray diffraction analysis. The stereo-structures of compound II and IV were also built up through Tripos force field based on crystal structures of compound I and III. RESULTS: The molecular formula and molecular weight were found to be C18H17O2N and 279.34 respectively. Compound I crystallized in monoclinic system, space group P2(1) with a = 0.5928(1), b = 1.5014(1), c = 1.6190(1) nm, V = 1.4410(3) nm3, Z = 4, Dx = 1.288 g.cm-3, Rf = 0.075, Rw = 0.073(w = 1/sigma 2|F|), S = 3.983; compound III crystallized in triclinic system, space group P1 with a = 0.5667(1), b = 1.2934(1), c = 2.1119 (1) nm, alpha = 102.17(1), beta = 90.25(1), gamma = 102.65(2) degrees, V = 1.4770(5) nm3, Z = 4, Dx = 1.224 g.cm-3, Rf = 0.047, Rw = 0.051(w = 1/sigma 2|F|), S = 0.467. CONCLUSION: These results showed that compound I and III both are cycloclausenamide except that the directions of the phenyl group on C6 are different. Cycloclausenamide can form 4 pairs of epimerides but the directions of the phenyl group does not affect their energy in free state.

Bridged Bicyclo Compounds, Heterocyclic↗
PubMed2000

Intracellular labeling study of neurons in the superficial part of the magnocellular layer of the medullary dorsal horn of the rat.

Morphology and electrical membrane properties of neurons in the superficial part of the magnocellular layer of the rat medullary dorsal horn (MDH: caudal subnucleus of the spinal trigeminal nucleus) were examined by using horizontal slice preparations. Intracellular recording and biocytin-injection combined with histochemical and immunohistochemical staining were done. Twenty-four neurons were examined successfully and classified into projection neurons (PNs) and intrinsic neurons (INs). The PNs were further divided into type I PNs (I-PNs) and type II PNs (II-PNs). The I-PNs sent axons to the medullary reticular formation; the II-PNs sent axons to the interpolar subnucleus of the spinal trigeminal nucleus but had no axons extending to the medullary reticular formation. The INs that sent no axons to the brain regions outside the MDH were also divided into small INs with spiny dendrites (INSSs) and large INs with aspiny dendrites (INLAs). The dendritic fields of the PNs extended to laminae I and II of the MDH and occasionally further to the spinal tract of the trigeminal nerve, whereas those of the INs were confined within the magnocellular layer of the MDH. The axonal branches of each IN formed a dense axonal mesh around the cell body of the parent neuron. Although the main bodies of the axonal fields of the INs were located in the magnocellular layer, some axonal branches extended to laminae I and II of the MDH. Immunoreactivity for NK1 receptor (substance P receptor) was found in approximately half of the PNs but not in the INs. Although no strong correlation was found between morphology and electrical membrane properties, there were some differences in electrical properties among the morphologically classified neuron groups, e.g., hyperpolarizing sag was observed in some PNs but not in the Ins; inward rectification was observed in some of the INSSs and INLAs but not in the PNs; the slow ramp depolarization and the slow afterdepolarization were observed in all INSSs examined but not in the PNs or INLAs.

Animals↗
PubMed2000

Chemokines are the main proinflammatory mediators in human monocytes activated by Staphylococcus aureus, peptidoglycan, and endotoxin.

It is widely believed that the cytokines tumor necrosis factor (TNF)-alpha, interleukin (IL)-1, and IL-6 are the main proinflammatory mediators induced in the host by bacteria and their cell wall components. To test this hypothesis, we compared the level of expression of 600 genes activated in human monocytes by Staphylococcus aureus, peptidoglycan, endotoxin, and interferon-gamma. These stimulants induced expression of over 120 genes, as identified by cDNA arrays. The highest activated genes for proinflammatory mediators induced by all three bacterial stimulants were chemokine genes (IL-8 and macrophage inflammatory protein (MIP)-1alpha), whereas cytokine genes (TNF-alpha, IL-1, and IL-6) were induced to a lower extent. Genes for other chemokines (MIP-2alpha, MIP-1beta, and monocyte chemoattractant protein-1) were also induced higher than the cytokine genes by peptidoglycan, and as high or higher than the cytokine genes by S. aureus and endotoxin. This high induction of chemokine genes was confirmed by quantitative RNase protection assay, and high secretion of chemokines was confirmed by enzyme-linked immunosorbent assays. Although genes for chemokines were the highest and genes for cytokines were the second highest induced genes by all three bacterial stimulants, each stimulus induced a unique pattern of gene expression. By contrast, expression of a completely different gene pattern was induced by a nonbacterial stimulus, interferon-gamma. These results establish chemokines as the main mediators induced by both Gram-positive and Gram-negative bacteria and are consistent with the highly inflammatory nature of bacterial infections.

Adult↗
PubMed2000

ATP facilitates spontaneous glycinergic IPSC frequency at dissociated rat dorsal horn interneuron synapses.

1. The ATP action on spontaneous miniature glycinergic inhibitory postsynaptic currents (mIPSCs) was investigated in rat substantia gelatinosa (SG) neurons mechanically dissociated from the 2nd layer of the dorsal horn in which their presynaptic glycinergic nerve terminals remained intact. 2. ATP reversibly facilitated the frequency of the mIPSCs in a concentration-dependent manner without affecting their amplitude distribution. The ATP agonist, 2-methylthioATP (2MeSATP), mimicked the ATP action, while another ATP receptor agonist, alphabeta-methylene-ATP (alpha,beta-meATP), had no effect on mIPSCs. 3. The ATP receptor antagonists, suramin (1 x 10-6 M) and pyridoxal-5-phosphate-6-azophenyl-2',4'-disulphonic acid (PPADS) (1 x 10-5 M), completely blocked the facilitatory effect of ATP on glycine release (102.0 +/- 11.2 % and 99.3 +/- 16.2 %, n = 6, respectively) without altering the current amplitude distributions. 4. N-Ethylmaleimide (NEM), a sulphydryl alkylating agent, suppressed the inhibitory effect of adenosine on mIPSC frequency (111.2 +/- 13. 3 %, n = 4) without altering the current amplitude distribution. However, ATP still facilitated the mIPSC frequency (693.3 +/- 245.2 %, n = 4) even in the presence of NEM. 5. The facilitatory effect of ATP (1 x 10-5 M) on mIPSC frequency was not affected by adding 1 x 10-4 M Cd2+ to normal external solution but was eliminated in a Ca2+-free external solution. 6. These results suggest that ATP enhances glycine release from nerve terminals, presumably resulting in the inhibition of SG neurons which conduct nociceptive signals to the CNS. This presynaptic P2X-type ATP receptor may function to prevent excess excitability in SG neurons, thus preventing an excessive pain signal and/or SG cell death.

Adenosine Triphosphate↗
PubMed2000

Total synthesis of gigantetrocin A.

A highly efficient synthetic method for the trans-tetrahydrofuran (THF) ring building block was established and the title compound was synthesized in 19 steps from trans-1,4-dichloro-2-butene via a convergent route with a Wittig reaction as the key step.

Aldehydes↗
PubMed2000

Complexity measure and complexity rate information based detection of ventricular tachycardia and fibrillation.

On the basis of non-linear dynamics, the paper uses a Lempel-Ziv complexity measure and presents a new definition of the information complexity rate: cc(n). Using such a definition, relative properties are obtained to help identify chaotic process accurately. Applying complexity analysis to abnormal ECGs recorded from patients with an implantable cardioverter defibrillator, the reasonableness of this information complexity and complexity rate approach are confirmed by means of biological experiments and computer simulations. Finally, objective analysis and explanations of the mechanisms of VT and VF are reported. The results indicate that, with the help of the complexity measure and complexity rate, recognition of ventricular tachycardia (VT) and ventricular fibrillation (VF) signals can be achieved with accuracy up to 100% (VT: 100%; VF: 98.7%).

Computer Simulation↗
PubMed2000

L-Type Ca(2+) channel charge movement and intracellular Ca(2+) in skeletal muscle fibers from aging mice.

In this work we tested the hypothesis that skeletal muscle fibers from aging mice exhibit a significant decline in myoplasmic Ca(2+) concentration resulting from a reduction in L-type Ca(2+) channel (dihydropyridine receptor, DHPR) charge movement. Skeletal muscle fibers from the flexor digitorum brevis (FDB) muscle were obtained from 5-7-, 14-18-, or 21-24-month-old FVB mice and voltage-clamped in the whole-cell configuration of the patch-clamp technique according to described procedures (Wang, Z.-M., M. L. Messi, and O. Delbono. 1999. Biophys. J. 77:2709-2716). Total charge movement or the DHPR charge movement was measured simultaneously with intracellular Ca(2+) concentration. The maximum charge movement (Q(max)) recorded (mean +/- SEM, in nC microF(-1)) was 53 +/- 3.2 (n = 47), 51 +/- 3.2 (n = 35) (non-significant, ns), and 33 +/- 1.9 (n = 32) (p < 0.01), for the three age groups, respectively. Q(max) corresponding to the DHPR was 43 +/- 3.3, 38 +/- 4.1 (ns), and 25 +/- 3.4 (p < 0.01) for the three age groups, respectively. The peak intracellular [Ca(2+)] recorded at 40 mV (in microM) was 15.7 +/- 0. 12, 16.7 +/- 0.18 (ns), and 8.2 +/- 0.07 (p < 0.01) for the three age groups, respectively. No significant changes in the voltage distribution or steepness of the Q-V or [Ca(2+)]-V relationship were found. These data support the concept that the reduction in the peak intracellular [Ca(2+)] results from a larger number of ryanodine receptors uncoupled to DHPRs in skeletal muscle fibers from aging mammals.

Aging↗
PubMed2000

Skeletal muscle mass and distribution in 468 men and women aged 18-88 yr.

We employed a whole body magnetic resonance imaging protocol to examine the influence of age, gender, body weight, and height on skeletal muscle (SM) mass and distribution in a large and heterogeneous sample of 468 men and women. Men had significantly (P < 0.001) more SM in comparison to women in both absolute terms (33.0 vs. 21.0 kg) and relative to body mass (38.4 vs. 30.6%). The gender differences were greater in the upper (40%) than lower (33%) body (P < 0.01). We observed a reduction in relative SM mass starting in the third decade; however, a noticeable decrease in absolute SM mass was not observed until the end of the fifth decade. This decrease was primarily attributed to a decrease in lower body SM. Weight and height explained approximately 50% of the variance in SM mass in men and women. Although a linear relationship existed between SM and height, the relationship between SM and body weight was curvilinear because the contribution of SM to weight gain decreased with increasing body weight. These findings indicate that men have more SM than women and that these gender differences are greater in the upper body. Independent of gender, aging is associated with a decrease in SM mass that is explained, in large measure, by a decrease in lower body SM occurring after the fifth decade.

Adolescent↗
PubMed2000

Huperzine A ameliorates the impaired memory of aged rat in the Morris water maze performance.

AIM: To determine the memory-improving properties of huperzine A in aged rats with memory impairments naturally occurring or induced by scopolamine. METHODS: Morris water maze was used to investigate the effects of huperzine A on the acquisition and memory impairments. RESULTS: During 7-day acquisition trials, aged rats took longer latency to find the platform. Huperzine A (0.1-0.2 mg/kg, s.c.) could significantly reduce the latency. In the probe trials on the eighth day, huperzine A (0.1, 0.2 and 0.4 mg/kg, s.c.) significantly increased the time in the quadrant where plateform had disappeared in aged rats. In the acute experiment, scopolamine (0.1 mg/kg, i.p.) significantly impaired spatial memory in the trained aged rats. Huperzine A (0.4 mg/kg, s.c.) significantly reversed the memory deficits induced by scopolamine. CONCLUSION: Huperzine A ameliorates the impaired memory naturally occurring or induced by scopolamine in aged rats.

Aging↗
PubMed2000

Synthesis, characterization and cytotoxicity of lanthanum(III) complexes with novel 1,10-phenanthroline-2,9-bis-alpha-amino acid conjugates.

Eight lanthanum(III) complexes with novel 1,10-phenanthroline-2,9-bis-alpha-amino acid conjugates were synthesized and characterized by elemental analyses, IR, MS, 1H-NMR, thermal analysis and conductance measurement. All lanthanum(III) complexes and the corresponding soluble ligand in water have been assayed for antitumor activity in vitro against HL-60 (human leukocytoma) cells, HCT-8 (human coloadenocarcinoma) cells, BGC-823 (human stomach carcinoma) cells, BeL-7402 (human liver carcinoma) cells and KB (human nasopharyngeal carcinoma) cells. The results show that several complexes have relative activity against different cell lines. In particular, the complexes La(L2) and La(L5) show relatively high activity against the BeL-7402 cell line. Moreover, they are slightly more effective than cisplatin. DNA binding studies indicate that the complex La(L2) possibly interacts with calf thymus DNA by both intercalative and covalent binding.

Amino Acids↗
PubMed2000

[Tissue engineering of skin].

OBJECTIVE: To review the recent progresses on tissue engineering of skin. METHODS: Recent original articles about tissue engineering of skin were extensively reviewed, which focused on the progresses and major problems concerning the epidermal substitutes, dermal substitutes, cultured-epidermal composite skin graft. RESULTS: Most investigators had come to conclusion that the optimal skin substitute should provide for immediate reconstruction of both the lost epidermis and dermis. The research was mainly focused on how to transplant epidermal cells immediately, preserve their activity and function, and develop the extracellular matrix which could effectively accelerate the function of transplanted cells, induce vascular growth from the wound bed, could be biodegradable, no toxicity and no danger of carrying pathogen. CONCLUSION: The major research trends of tissue engineering of skin should be focused on the study of immediate transplantation of epidermal cells, accelerate wound healing and developing extracellular matrix of dermis.

Cell Transplantation↗
PubMed2000

[Chemical approaches to the research & development of modern traditional Chinese pharmacy].

OBJECTIVE: To study chemical approaches to the research and development of modern traditional chinese pharmacy. METHOD: To put forward several views on the aspects that concerns chemical approaches to the research and development of modern traditional chinese pharmacy. RESULT AND CONCLUSION: Dactyloscopic system should be set up for the quality control of traditional chinese medicinal materials and preparations. In the research of effective components in traditional chinese medicines proper treatment should be given to the new compounds that arise in the process of decocting compound prescriptions.

Animals↗