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Biomedical subjects

Z S Wang

Publications and source records attributed to Z S Wang.

At least 19 recordsLinked to original sources
PubMed1992

Neurite branching pattern formation: modeling and computer simulation.

A model for nerve cell pattern formation is proposed in this paper. The model is based on some experimental results and an assumption that there is a kind of inhibitive interaction between growing neurites on the same nerve cell. In this paper, this interaction is termed lateral inhibition. A group of ordinary differential equations are used to describe the elongation of the terminal neurite segments of individual nerve cells. Computer simulation and comparison of it with in vitro studies are also made in this paper.

Animals↗
PubMed1992

Inhibition of cutaneous contact hypersensitivity in the mouse with systemic or topical spiperone: topical application of spiperone produces local immunosuppression without inducing systemic neuroleptic effects.

We tested the ability of the neuroleptic agent spiperone (8-[3-(p-fluorobenzoyl)propyl]-1-phenyl-1,3,8-triazaspiro-[4.5] decan-4- one) to influence the tissue swelling and leukocyte infiltration associated with T-cell--dependent immune responses, i.e., contact hypersensitivity reactions, in mice. Contact hypersensitivity reactions were elicited by applying the haptens oxazolone or dinitrofluorobenzene topically to one or both ears 5-8 d after epicutaneous sensitization. When spiperone was given subcutaneously at a dose of 30 or 150 mg/kg, 1 h after challenge with oxazolone, cutaneous contact hypersensitivity to this hapten was significantly diminished. When applied topically in concentrations as low as 0.08% (w/w), preparations of spiperone significantly suppressed both the tissue swelling and the leukocyte infiltration associated with the elicitation phase of contact hypersensitivity. Topical treatment with spiperone also suppressed the sensitization phase of contact sensitivity. However, mice treated topically with spiperone, unlike those treated systemically, exhibited no drowsiness or other evidence of central nervous system effects. Spiperone expresses both serotonin and dopamine receptor antagonist activity. However, unlike spiperone, the chemically unrelated serotonin antagonists, trazadone and mianserin, and the dopamine receptor antagonist, haloperidol, were not effective in suppressing contact hypersensitivity. Our results indicate that spiperone can have immunosuppressive effects on contact hypersensitivity reactions in the mouse, even when applied topically in doses that lack neuroleptic effects, and that the mechanism of action of spiperone on the immune response may be independent of its serotonin or dopamine receptor blocking properties.

Administration, Topical↗
PubMed1991

Serum sialic acid levels in patients with oral and maxillofacial malignancy.

Serum sialic acid levels were measured using the thiobarbituric acid method in 80 healthy subjects and in 40 patients with benign and 61 with malignant tumors in the oral and maxillofacial region. It was shown that the cancer group had statistically higher sialic acid levels than control group and the group with benign disease (P less than .05), but no significant difference was noted between the normal control group and the patients with benign tumor (P greater than .05). Serum sialic acid levels were significantly higher in the patients with stages III and IV cancer than in those individuals with stage I and II cancer, but no differences were seen between stages I and II, and between stages III and IV cancer patients (P greater than .05). There was also no difference when considering the anatomic site of the malignant lesion. Furthermore, during the serial sialic acid determination in cancer patients before and following treatment, the sialic acid levels usually declined with remission of the disease and increased with recurrence, metastasis, or a poor prognosis. We conclude from this study that the sequential measurement of sialic acid level is particularly useful in monitoring patients with oral cancer, and sialic acid may prove to be a valuable tumor marker in oral and maxillofacial malignancy.

Aged↗
PubMed1991

Recruitment of neutrophils during IgE-dependent cutaneous late phase reactions in the mouse is mast cell-dependent. Partial inhibition of the reaction with antiserum against tumor necrosis factor-alpha.

Much of the clinically important pathology associated with IgE-dependent disorders is thought to reflect the actions of the blood-borne leukocytes recruited during these responses. To evaluate the extent to which mast cells are responsible for the leukocyte infiltration associated with IgE-dependent cutaneous reactions, we attempted to elicit these responses in normal mice, genetically mast cell-deficient W/Wv mice, and in W/Wv mice selectively repaired of their mast cell deficiency by the intradermal injection of cultured mast cells derived from the congenic normal (+/+) mice. We found that the tissue swelling associated with IgE-dependent passive cutaneous anaphylaxis reactions developed rapidly and diminished markedly from 2 to 4 h after antigen challenge, but remained detectable for at least 24 h after elicitation of the responses. Infiltration of leukocytes (predominantly neutrophils) also occurred at these sites, but reached maximal levels 6-12 h after antigen challenge, persisted at high levels for 24 h, and largely waned by 48 h. Virtually all of the tissue swelling and leukocyte infiltration associated with IgE-dependent cutaneous reactions was mast cell dependent. Intradermal injection of 40 U of recombinant murine TNF-alpha (rmTNF-alpha) elicited neutrophil infiltration similar in magnitude and kinetics to that observed after IgE-dependent mast cell degranulation. A rabbit anti-rmTNF-alpha (R anti-rmTNF-alpha) antiserum, which was able to inhibit 84% of the neutrophil infiltration observed after i.d. injection of rmTNF-alpha, inhibited IgE-, and mast cell-dependent leukocyte infiltration by 47 +/- 7% in three separate experiments. These findings indicate that TNF-alpha contributes to mast cell-dependent recruitment of leukocytes during IgE-dependent cutaneous late phase reactions, but suggest that other mast cell-associated mediators probably also contribute to this response.

Animals↗
PubMed1991

Studies on the mutagenicity of hair dyes made in China.

A total of 13 commercial hair dye products made in China were tested for mutagenicity in 2 short-term bioassays, the histidine-requiring mutants of Salmonella typhimurium (strains TA98 and TA100) and the micronucleus test with mouse bone-marrow polychromatic erythrocyte cells in vivo. The results showed that the 13 hair dyes were not mutagenic in strains TA98 and TA100 with and without S-9. In the micronucleus test, no mutagenic effect was observed.

Animals↗
PubMed1991

[High resolution chromosome G-banding pattern of domestic pig of China].

Lising methotrexate or thymidine treatment to induce synchronous division, combined with GTG technique, the high resolution banded chromosomes of seven domestic pig breeds of China were investigated. No distinct difference was found among then. Hence, in line with The International System for Human Cytogenetic Nomenclature, a standard idiogram of high resolution G-banded karyotype of domestic pig is suggested in this paper. In the idiogrammatic presentation of G-banding pattern, all the regions and bands of each pair of chromosomes are designated and described with slight modifications for the landmark system. Up to 444 bands were detected per haploid set, including the X and Y chromosomes, a number nearly two times as much as that in banded metaphase chromosomes.

Animals↗
PubMed1990

Gastroesophageal anastomotic leakage following resection of carcinoma of the esophagus and gastric cardia: analysis of ten cases.

Postoperative anastomotic leakage is one of the most dangerous and, unfortunately, most frequent complications. Many methods have been tried to prevent such leakage. The incidence of leakage has decreased to 3.84% in our hospital in recent years. Ten cases of gastroesophageal anastomotic leakage following resection of carcinoma of the esophagus and gastric cardia are analyzed and a new tool, the three-leaf clamp, which reduced the anastomotic leakage, is introduced.

Anastomosis, Surgical↗
PubMed1990

Flow cytometric DNA-ploidy as a prognostic indicator in oral squamous cell carcinoma.

In an attempt to evaluate the significance of DNA-ploidy as an objective prognostic indicator of oral squamous cell carcinoma, a retrospective analysis of 70 paraffin-embedded specimens using flow cytometry was performed. Forty-one patients (58.6%) had aneuploid tumors and 29 patients (41.4%) had diploid DNA distribution patterns. There was a significant difference in 5-year disease-free survival rates between patients with aneuploid and diploid tumors. The difference in cervical metastatic rates between aneuploid and diploid group approximated statistical significance. No obvious correlation was observed between DNA indices and histologic grade, clinical stage or tumor size. It is concluded that patients with aneuploidy primary tumors have a significantly poorer prognosis and higher risk for regional metastases than those with diploid tumors.

Aneuploidy↗
PubMed1990

[Expression of constitutive heterochromatin by AluI restriction endonuclease treatment and CA3/DA/DAPI staining of domestic pig chromosome].

The heterogeneity of constitutive heterochromatin in two domestic pigs has been studied by restriction endonuclease AluI banding, CA3/DA/DAPI banding and C-banding techniques. The results show that the centromere constitutive heterochromatin can be subdivided into three types, which located in different chromosomes. It is found that there is correspondence between No. 13--18 chromosomes in pigs and No. 1, 9, 16, Y chromosome in human by comparing the banding patterns of AluI and CA3/DA/DAPI. Therefore, it is revealed that satellite DNAs in constitutive heterochromatin of chromosomes mentioned above are similar.

Animals↗
PubMed1989

Reduction of enteric infectious disease in rural China by providing deep-well tap water.

Enteric infectious disease (EID), defined here as bacillary dysentery, viral hepatitis A, El Tor cholera, or acute watery diarrhoea, is an important public health problem in most developing countries. This study assessed the impact on EID of providing deep-well tap water (DWTW) through household taps in rural China. For this purpose, we compared the incidence of EID in six study villages (population, 10,290) in Qidong County that had DWTW with that in six control villages (population 9397) that had only surface water. Both the bacterial counts and chemical properties of the DWTW met established hygiene standards for drinking water. The incidence of EID in the study region was 38.6% lower than in the control region; however, the introduction of DWTW supplies did not significantly affect the incidence of bacillary dysentery. These results indicate that the construction and use of DWTW systems with household taps is associated with decreased incidences of El Tor cholera, viral hepatitis A, and acute watery diarrhoea. Since high construction costs have led many authorities to question the value of DWTW, we carried out a cost-benefit analysis of the programme. The cost of constructing a DWTW system averaged US $36,000 at 1983 prices, or US $10.50 per capita. The combined capital and operating costs of a DWTW system were US $1.46 per capita per annum over its 20-year estimated life. The benefits derived from reductions in cost of illness and savings in time to fetch water were 2.2 times the costs at present values Capital outlays were recouped in a 3.6-year payback period and the provision of DWTW proved highly beneficial in both economic and social terms.

Adolescent↗
PubMed1989

[Cryosurgery in rectal carcinoma--report of 41 cases].

Fourty-one patients with rectal carcinoma treated by cryosurgery in our hospital from 1973 to 1982 are presented. The 5, 4, 3, 2, and 1-year survival rates were 34.1%, 41%, 56%, 66% and 90%, respectively Eighteen patients who underwent radical cryosurgery gave a 5-year survival rate of 66%. The results showed that cryosurgery inhibited the multiplication of cancer cells and improved immune response through observing the changes of DNA content, ultrastructures, anti-bodies (IgG, A, M), T-cell subpopulations (OKT3, OKT4, OKT8) and so on. Cryosurgery could avert colostomy when used for rectal carcinoma.

Adenocarcinoma↗
PubMed1987

Effect of cooling of the culmen of the cerebellar vermis on chemically induced stepping in guinea pigs.

A regular 'stepping automatism' was induced via our recently reported SIS (substances capable of inducing stepping) in guinea pigs. Reversible cooling (5-0 degrees C) or partial ablation of the culmen of the cerebellar vermis could facilitate SIS-induced stepping, whereas electrical stimulation (300 microA up) of the same region could attenuate or abolish stepping. Cooling could only facilitate, but not trigger stepping movements. The above-mentioned facilitation was most prominent in those guinea pigs that exhibited a weak stepping automatism. Cooling of the lateral part of the culmen of the cerebellar vermis and hemisphere mainly facilitated stepping of the ipsilateral forelimb. When the interfacial temperature between the cooling probe and tentorium cerebelli was appropriate (5-0 degrees C), cooling could mimic the effects of ablation to a great extent.

Animals↗