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Biomedical subjects

H M Zheng

Publications and source records attributed to H M Zheng.

16 recordsLinked to original sources
PubMed2001

The POU homeodomain protein Oct-1 binds Cis-regulatory element essential for the human GnRH upstream promoter activity in JEG-3 cells.

In previous studies, we have localized four specific nuclear protein-binding elements in the human GnRH upstream promoter. To test whether these four elements are reproductive tissue specific, we placed the four elements upstream to a thymidine kinase (TK) promoter/luciferase reporter gene, and transfected the constructs into human placental choriocarcinoma (JEG-3) cells. The 272-bp fragment (-994 to -723) containing the four elements can drive heterologous TK promoter expression in JEG-3 cells about 15 times more than that of basal TK promoter activity. Deletion of element 4 (E4, -987/-968) significantly decreased (4-fold) the luciferase activity. Further deletion of the other elements (E3 individual, -960/-940 or E3 and E2 in combination, -919/-896) only slightly decreased the luciferase activity. In contrast, deletion of element 1 (E1, -876/-851) caused a 2-fold loss of luciferase activity and elimination of E2 and E3 only lost less than 2-fold of the luciferase activity. Study performed with 5' end deletion of this region confirmed these observations. Furthermore, E4 DNA-protein complex can be supershifted by Oct-1 antibody, indicating that Oct-1 binds to E4. These results clearly demonstrated that all four elements are required to confer tissue-specific expression of the hGnRH gene in JEG-3 cells. However, the E4 is the most important for the tissue-specific expression of the hGnRH gene in JEG-3 cells. Oct-1 factor binds with E4 element and may be involved in the mediation of the human GnRH upstream promoter activity.

DNA-Binding Proteins↗
PubMed2000

A 10-year follow-up study of contraceptive Norplant implants.

OBJECTIVES: To evaluate the long-term efficacy and health problems associated with Norplant implants and re-implants after 5 full years of first implants. METHOD: From 1984 to 1988, 1657 women accepted first implants of Type I and Type II of Norplant, and 394 first acceptors had a re-implant, at a clinic for study. The clinical records and annual follow-up data of acceptors were analyzed. The life-table technique was the main method used. RESULTS: The continuation rates were very high. The cumulative pregnancy rates at 1, 3 and 5 full years of use were 0.0%, 0.1% and 0.7%, respectively. Users with heavier body weight had higher pregnancy rates. The rate of menstrual disturbances peaked at 73% after 3 months and consistently decreased to 20% at 5 years of use. Rates of menstrual disturbances associated with re-implants were much lower. CONCLUSION: Norplant is extremely effective and safe for long-term use.

Adult↗
PubMed1999

Estrogen receptor-mediated repression of gonadotropin-releasing hormone (gnRH) promoter activity in transfected CHO-K1 cells.

To examine the transcriptional regulation of gonadotropin-releasing hormone (GnRH) gene in reproductive tissues, the expression of human GnRH gene promoter in cultured human granulosa cells and a Chinese hamster ovary-derived CHO-K1 tumor cells was studied. Transfection of luciferase reporter gene construct containing either upstream (hU) or downstream (hD) human GnRH gene promoter into both human granulosa and CHO-K1 cells showed that the upstream promoter, hU, was more active than hD in directing luciferase expression in these ovarian tissues. CHO-K1 cells transfected with either hU or hD construct showed insignificant changes in luciferase activity in response to 17beta-estradiol and GnRH. However, cotransfection of hU construct with a vector expressing a human estrogen receptor-alpha (ER-alpha) cDNA results in dose-dependent decreases in luciferase activity in response to both 17beta-estradiol and a GnRH agonist. By functional analysis of a series of deletion constructs, the ER-mediated suppression of GnRH promoter activity by 17beta-estradiol was localized to a region between -169 and -548 bp 5' of the upstream transcription start site of the human GnRH gene. Results of this study demonstrated that estrogen receptor can mediate the negative feedback regulation of human GnRH upstream promoter activity by both estrogen and GnRH in the ovary.

Animals↗
PubMed1999

A randomized multicenter study comparing the efficacy and bleeding pattern of a single-rod (Implanon) and a six-capsule (Norplant) hormonal contraceptive implant.

To compare the contraceptive efficacy, tolerability, and bleeding patterns, 200 healthy female volunteers received, in an open, comparative, randomized, multicenter study in China, either a single-rod (Implanon) or a six-capsule (Norplant) contraceptive implant for 2 years with an optional extension of up to 4 years. Women were exposed to Implanon for 341.6 woman-years and Norplant for 329.1 woman-years. There were no pregnancies during the study. Per 90-day reference period, the median number of bleeding/spotting days with Implanon decreased from 33.5 in the first period to 19.0-21.5 days in the last year. Similarly, with Norplant, the median number of bleeding/spotting days decreased from 34.5 to 18.0-23.0 days, respectively. The number of bleeding/spotting episodes during year 1 was 2.0 per 90-day reference period with Implanon and 3.0 per period with Norplant (p < 0.05 for periods 1-4). For the remaining 90-day periods, there was no statistical difference between the two groups. In general, there was less frequent bleeding with Implanon compared with Norplant, whereas the incidences of amenorrhea and infrequent bleeding were higher with Implanon than with Norplant. The mean overall incidence of prolonged bleeding fell markedly during the study, from 66.0% in reference period 1 to 27.3% in period 16 with Implanon and from 69.0% to 21.7% with Norplant, respectively. The most common adverse events were related to disturbed bleeding patterns, which were also the major reasons for discontinuation (Implanon n = 8; Norplant n = 14). Normal menses returned in almost all subjects within 3 months after removal of the implants. Implanon was inserted in a mean time of 0.61 min and Norplant in 3.90 min (p < 0.001). Similarly, the mean time required to remove the implant was significantly shorter for Implanon than for Norplant (2.18 min vs 11.25 min, p < 0.001). The maximum time required for removal of the implant was 10 min for the Implanon group and 60 min for the Norplant group. In both groups, blood pressure and hemoglobin were not affected, whereas body weight tended to increase. It can be concluded that both contraceptive systems demonstrated excellent contraceptive efficacy and were well tolerated. Compared with Norplant, there was less frequent bleeding with Implanon, whereas the incidence of infrequent bleeding and amenorrhea was higher. Implanon was significantly quicker to insert and to remove than was the multiple capsule system.

Adult↗
PubMed1999

A long-term study of the efficacy and acceptability of a single-rod hormonal contraceptive implant (Implanon) in healthy women in China.

OBJECTIVE: To investigate the contraceptive efficacy, cycle control and acceptability of Implanon, a new single-rod, progestogen-only contraceptive implant. METHODS: In a non-comparative, open, multicenter study, a contraceptive implant containing the progestogen etonogestrel was inserted into 200 healthy women. The study duration was 2 years, with an optional extension up to 4 years. RESULTS: Women were exposed to Implanon for 644.6 woman-years. There were no pregnancies during the study. Per 90-day reference period, the median number of bleeding-spotting days ranged between 18 and 21 and the median number of bleeding-spotting episodes was two. The mean overall incidence of prolonged bleeding fell markedly during the study, from 69% in the first reference period to 26% in the 16th period. The most common adverse events were related to disturbed bleeding pattern and amenorrhea. Heavy or prolonged bleeding caused 18 subjects to withdraw from the study. Only a few subjects discontinued the study early due to irregular bleeding (2%) or amenorrhea (2%). A slight increase in mean body weight was observed. The implant was removed in an average time of 2.9 min. CONCLUSIONS: Implanon demonstrated excellent contraceptive efficacy for 4 years of use and was well tolerated. The incidences of prolonged bleeding and amenorrhea both fell markedly with continued implant use. Because of its single-rod design, Implanon was quickly removed with few complications and proved to be a highly acceptable method of contraception.

Adult↗
PubMed1994

Viral induction of low frequency interferon-alpha producing cells.

The human peripheral blood mononuclear cells responsible for IFN-alpha production in response to viral stimuli have been most often described as either monocytes (as typified by the response to Sendai virus) or as a light density, HLA-DR+ population which is negative for most cell surface markers characteristic of mature T cells, B cells, monocytes, or natural killer cells (as typified by the response to Herpes simplex virus (HSV)). The frequency of IFN-alpha-producing cells (IPC) responding to Sendai virus is typically 10-fold or more higher than those responding to HSV. In the current study, we have used ELISpot assays to determine the frequency of IPC responding to DNA and RNA viruses including HSV, Sendai, vesicular stomatitis virus, cytomegalovirus, adenovirus, SV40, influenza, measles, mumps, Newcastle disease virus (NDV) and human immunodeficiency virus (HIV). The enveloped viruses but not the nonenveloped viruses (adenovirus and SV40) elicited an IFN-alpha response. The frequency of IPC for each of the other viruses was more similar to the low frequency HSV-responding population than to the higher frequency Sendai virus response. These included several viruses in the same family as Sendai virus, namely the paramyxo viruses measles, mumps, and NDV. IPC were also tested for sensitivity to the lysosomotropic drug chloroquine, which diminishes IFN-alpha produced in response to HSV but not Sendai virus. With the exception of Sendai virus, chloroquine treatment abrogated the majority of IFN-alpha produced and IPC against each of the viruses. We conclude that low frequency, nonmonocytic NIPC account for the majority of IFN-alpha production in response to different viruses.

Cell Line↗
PubMed1993

[Experimental study of Ligusticum wallichii on cerebrovascular hemodynamic parameters].

The model of experimental atherosclerosis was established by means of dietary hyperlipidemia and repeated intravenous injection of heterologous serum to make the immunologic injuries of arterial endothelium, in which the effect of Ligusticum wallichii (LW) on the cerebrovascular hemodynamic parameters (CVHP) was observed. All CVHP indexes in LW group were near that of normal group, and there was no significant difference between these two groups. The carotid arteries' mean flow (Qmean), mean velocity (Vmean), maximal velocity (Vmax), cerebrovascular peripheral compliance for zero pressure and cerebrovascular peripheral resistance (R) in LW group were significantly better than that of atherosclerotic control group (P < 0.05-0.01). The results showed that LW had protective effects on cerebral vessels.

Animals↗
PubMed1990

Study of Norplant implants in Shanghai: three-year experience.

A clinical follow-up study conducted in Shanghai, China confirmed earlier reports that the Norplant implants, Norplant-1 and Norplant-2, are both highly effective with high continuation rates. The implants, however, tend to cause menstrual disturbance, spotting and bleeding. The mean hemoglobin value, however, did not change and the blood pressure remained stable. The report of 8 cases of thrombocytopenia among 301 Norplant-2 users is a source of concern.

Adult↗
PubMed1989

[Changes in serum FSH, LH and ovarian follicular growth during electroacupuncture for induction of ovulation].

Changes in serum FSH, LH and follicular sizes were observed in chronically anovulatory patients during electroacupuncture treatment (EAT) for induction of ovulation. 7 cases were diagnosed as PCOD, 3 as dysfunctional uterine bleeding, and 1 as hypogonadotropic amenorrhea. Among them 8 cases complained of infertility for 2.7 years on average. Ovulation was confirmed by pregnancy or the combination of biphasic BBT and ultrasonographic evidence. During one cycle with 3-day EAT on acupoints Ren 3, 4, Extra 16 and Sp 6, ovulation resulted in 5 patients (ovulatory group) and among the 5 cases, 3 of 4 infertile cases became pregnant. The other 5 cases remained in anovulation (anovulatory group); of them 3 cases got biphasic BBT, but no typical ovulatory signs were found on ultrasonography; 2 cases remained in monophasic BBT. Serum FSH, LH values were elevated in ovulatory group, and FSH pulsatile frequency increased significantly during EAT (from 2.10 +/- 0.42/4h to 3.70 +/- 1.64/4h), but not in anovulatory group. No apparent changes were found in serum LH pulsatile frequency and pulsatile amplitudes of FSH and LH in this study. In ovulatory group diameters of ovarian follicles increased markedly, while diameters of anovulatory group stopped to grow at 14-16 mm. It is suggested that ovulation may be induced by EAT via a regulation on hypothalamic-pituitary function leading to normal secretion of FSH and LH.

Acupuncture Therapy↗
PubMed1989

Rigid spine syndrome. Report of 4 cases.

Four cases of rigid spine syndrome are reported for the first time in China. They are 2 males and 2 females. One girl has a positive family history. Limitation of flexion of the cervical and dorsolumbar spine, contractures of joints, especially the elbow joints, extreme flattening of the chest and scoliosis are the prominent symptoms of this syndrome. The clinical criteria for this rigid spine syndrome tally with those described by Dubowitz (1965). Symptomatology, diagnosis, differential diagnosis and genetics are discussed. However, the question whether rigid spine syndrome is a single, well defined disease entity remains to be explored.

Adolescent↗