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Biomedical subjects

D Y Chen

Publications and source records attributed to D Y Chen.

At least 91 records · Page 5Linked to original sources
PubMed1990

Evaluation of mizoribine as an immunosuppressant in subrenal capsule assay using immunocompetent mice.

We studied the application of mizoribine (MZR) to normal immunocompetent mice in subrenal capsule assay (SRCA) by means of tumor growth curve determination, histological analysis and autoradiography. At 400 mg/kg, MZR prolonged the actual tumor growth and moderately reduced the host reaction. Doses below 200 mg/kg did not effectively suppress the host reaction. The maximal weight loss of mice in the 400 mg/kg group reached 29%, but did not exceed 10% within 8 days. Hence, we applied 400 mg/kg of MZR to SRCA for up to eight days for cancer chemotherapy testing. This dose of MZR did not affect the labeling index of tumor cells compared with the control.

Animals↗
PubMed1990

Dynamic changes of the cervical ligamental flavum in hyperextension---hyperflexion movement and their measurements.

Ten fresh cadaver cervical spine specimens were frozen and bisected through the median sagittal plane. The length, thickness of the ligamental flavum (LF) and its protruding depth into the cervical canal were measured in hyperextension, hyperflexion and mid-position. The results showed that LF was elongated and became thinner in hyperflexion and shortened, thickened, and protruded into the cervical canal in hyperextension. The protruding depth into the canal was 3.5 +/- 0.35 mm at C 5-6, 3.25 +/- 0.50 mm at C 4-5 and 2.96 +/- 0.35 mm at C 6-7 respectively. Segmental stenosis was observed at the level of intervertebral space in hyperextension.

Adult↗
PubMed1989

Study on in vitro sperm capacitation and egg-penetration of giant panda.

A preliminary report on in vitro sperm capacitation and egg-penetration of giant panda is briefly presented. The panda spermatozoon consists of head, neck and tail, just like the spermatozoa of other animals. Before capacitation sperm heads clustered together and dispersed after capacitation. They were then able to swim straight forward. During the time of in vitro capacitation the plasma membrane of the sperm head was first expanded to various degrees, then disintegrated, and finally became detached. The electro-dense material in the acrosome appeared in small clumps with high density. Extensive vesiculation occurred between the bi-layered acrosome membranes and thus led to disintegration. Vesiculation in panda sperm differs from that reported in hamsters. When the capacitated panda spermatozoa came into contact with the hamster eggs, the region between the acrosome collar and postacrosome cap first fused with the egg membrane followed by the penetration of the nucleus into the cortex of the egg. Some of the penetrating sperm nuclei became decondensed and some did not. The success of in vitro sperm capacitation and egg-penetration of giant panda is of great significance, suggesting that it is possible to carry out in vitro fertilization and embryo transplantation in this endangered species.

Acrosome↗
PubMed1988

Effects of cimetidine, progesterone, cannitracin and tolazoline on the weight and DNA content of the testosterone-induced hyperplastic prostate of the rat.

The antiandrogenic potency of cimetidine, progesterone, cannitracin and tolazoline was studied in intact immature rats by determination of the weight and DNA content of the ventral prostate. Cimetidine is a H-2-receptor histamine antagonist, cannitracin is an antifungal antibiotic derived from Strp-griseus and tolazoline is an alpha-adrenergic blocker similar to phentolamine. All rats (except the control group) received testosterone propionate (TP) 0.3 mg s.c. with the drugs above every day for one week. Cimetidine, progesterone and cannitracin, but not tolazoline, significantly decreased the weight and DNA content of the hyperplastic prostate induced by TP. The results indicate that cimetidine, progesterone and cannitracin have an antiandrogenic effect. This study provides the basis for investigating the effects of antiandrogen in men with symptomatic benign prostatic hyperplasia.

Androgen Antagonists↗
PubMed1988

Interstitial pneumonitis after allogeneic bone marrow transplantation. Nine-year experience at a single institution.

Of 386 patients with allogeneic bone marrow transplants (BMT) treated during a 9-year interval, 166 developed interstitial pneumonitis (IP). Idiopathic and cytomegalovirus (CMV) IP constituted 90% of the 113 cases in which tissue was examined. Risk factors for IP overall were acute graft-versus-host disease (AGVHD), remote transplant date, the diagnosis of leukemia, and GVHD prophylaxis with agents other than cyclosporine. Risk factors for CMV IP were pre-transplant CMV seropositivity, CMV excretion, age greater than 10 years, AGVHD, GVHD prophylaxis with agents other than cyclosporine, and a remote transplant date. Patients transplanted for aplastic anemia were at lower risk for idiopathic IP than those transplanted for leukemia. The incidence of IP in patients given busulfan plus cyclophosphamide was equivalent to that in patients receiving cyclophosphamide plus total body irradiation. The incidence of idiopathic IP remained constant over this 9-year period while CMV IP declined significantly.

Adult↗
PubMed1988

The Sino-MONICA-Beijing Study: report on results between 1984 and 1986.

The Beijing Heart Lung and Blood Vessel Medical Center has participated in the World Health Organisation MONICA project since 1981. Our study, named Sino-MONICA-Beijing, has been carried out in Beijing and covers a population approximately of 700,000. After a 2-year pilot study, the project started formally January 1, 1984. This paper presents the organization and methodology of the study, with emphasis on the monitoring system and on how events were found. The main results of the cardiovascular disease (CVD) event monitoring are as follows: average annual mortality from all causes, for the 3-year period of 1984-86 was 319/100,000 for men and 238/100,000 for women aged 25-64; from CVD 119/100,000 for men and 101/100,000 for women; from ischemic heart disease 29/100,000 for men and 14/100,000 for women; and from cerebrovascular disease 59/100,000 for men and 52/100,000 for women. Preliminary experience has shown that Sino-MONICA-Beijing is a well-standardized project of long-term surveillance of CVD in the communities of Beijing.

Adult↗
PubMed1988

Cytomegalovirus infection after autologous bone marrow transplantation with comparison to infection after allogeneic bone marrow transplantation.

Cytomegalovirus (CMV) infection was detected in 65 of 143 (45%) autologous bone marrow transplant (BMT) patients. CMV pneumonitis occurred in only 2% of the patients and CMV retinitis occurred in none. Infection occurred in half of the 40 initially seronegative patients and 47% of the 94 initially seropositive patients. Among initially seropositive patients, platelet recovery was slower in infected patients than in those not infected (97 v 35 days median, P = .003), and neutrophil recovery was slightly delayed in infected patients (31 days v 24 days, P = .02). Although the incidence of CMV infection was comparable in autologous and allogeneic BMT patients, CMV pneumonitis was less frequent in autologous BMT patients (2% v 12%, P less than .001). The risk for CMV pneumonitis in autologous BMT patients was comparable with that in allogeneic BMT patients without graft-v-host disease (GVHD) (2% v 6%), but significantly lower than the risk in allogeneic BMT patients with GVHD (2% v 23%, P less than .001).

Bone Marrow Transplantation↗
PubMed1988

[An experimental study on SRCA (subrenal capsule assay)--comparison of the test between normal and nude mice].

Six-day SRCA using normal mice developed by Bogden et al. is a promising in vivo chemosensitivity test. However, this method has a problem on the influence of the host reaction. We compared the tumor growth kinetics and host reaction between normal and nude mice. The tumor diameter increased until day 6 in normal and day 16 in nude mice, but the histological finding revealed many host reactive cells and few viable tumour cells on day 6 in normal mice, and well preserved tumour cells on day 16 in nude mice. These results were supported by flow cytometrical analysis. Autoradiogram using 3H-TdR showed a recovery of labeling index to the steady label by day 1. This index was similar between normal and nude mice. When antitumor activity of adriamycin, cisplatin or mitomycin C was compared with nude mice system, the order of effectiveness was the same as the system using nude mice implanted tumor cells subcutaneously and given the drugs intraperitoneally, but different in normal mice.

Adenocarcinoma↗