Biomedical subjects

Y X Liu

Publications and source records attributed to Y X Liu.

At least 37 records · Page 2Linked to original sources

PubMed1999

Cloning of novel temperature-related expressed sequence tags in rat testis during spermatogenesis.

Spermatogenesis needs the relatively cool environment of the scrotum in most mammals, it would be arrested when the testis was exposed to abdominal temperature. In this study, we have used a differential display PCR technique (DD-PCR) to screen temperature-related ESTs during spermatogenesis (TRS) in scrotal testes through a unilateral cryptorchid rat model after in situ analysis of testis cell DNA fragmentation. We reported here the cloning and sequencing of three such ESTs: TRS1, TRS3, and TRS4. Northern blot analysis confirmed that they were expressed specifically in scrotal testes. In situ hybridization showed that TRS1 was mainly expressed in the spermatocytes and the round spermatids in scrotal testis. Homology searches revealed that TRS1 and TRS3 were unknown cDNA sequences, and TRS4 was identical to a known EST whose function had not been reported. TRS1, TRS2, and TRS3 were first found to be temperature-related during spermatogenesis.

Animals↗

PubMed1999

Anatomic basis of iliac crest flap pedicled on the iliolumbar artery.

This paper presents the anatomy and clinical applications of an iliac crest flap pedicled on the iliolumbar artery. 54 iliolumbar arteries were filled with pink plastic in 27 adult cadavers. Their origin, course and branches, and the surroundings were investigated, and the external diameter, length of segments and terminal distribution were measured. The iliolumbar artery was constant, but with a few variations. Its length was 7.0 +/- 3.9 cm, and the outer diameter 2.0 +/- 0.4 mm at the lateral edge of the psoas major muscle. Based on the anatomic findings, the surgical technique for a bone flap based on the iliolumbar artery was designed. Its clinical applications included both free bone grafting (in 2 patients) and pedicled bone transfer (in another 2 patients). The clinical results were satisfactory. The iliac crest flap pedicled on the iliolumbar artery is a reliable bone flap for clinical usage.

Adult↗

PubMed1999

Early linear growth retardation in Chongqing, China.

OBJECTIVES: The objectives of this study were to investigate early linear growth retardation and to identify potential risk factors for it. METHODOLOGY: A community-based prospective study was performed in Chongqing, China, with infants being examined at 12 and 15 months of age. A total of 101 infants were examined twice. Supine length, bodyweight, lower leg length, head circumference, middle upper arm circumference and biceps skinfold thickness were measured. RESULTS: The prevalence of short stature (length-for-age standard deviation score, < -2) was 22% and 23% at 12 and 15 months of age, respectively, while the incidence of growth stunting (low growth velocity) between 12 and 15 months of age was 24%, using the stunting screening method. A mother having a history of abortion and infants having current episodes of diarrhoea were identified as risk factors for growth stunting. CONCLUSIONS: We conclude that both short stature and growth stunting are common in the population studied. The stunting screening method used is applicable in developing communities.

Anthropometry↗

PubMed1999

Expression of tissue type and urokinase type plasminogen activators as well as plasminogen activator inhibitor type-1 and type-2 in human and rhesus monkey placenta.

The distribution of mRNAs and antigens of tissue type (t) and urokinase type (u) plasminogen activators (PA) plus their corresponding inhibitors, type-1 (PAI-1) and type-2 (PAI-2) were studied in human and rhesus monkey placentae by in situ hybridisation and immunocytochemistry. Specific monkey cRNA and antibodies against human tPA, uPA, PAI-1 and PAI-2 were used as probes. The following results were obtained. (1) All the molecules tPA, uPA, PAI-1 and PAI-2 and their mRNAs were identified in the majority of the extravillous cytotrophoblast cells of the decidual layer between Rohr's and Nitabuch's striae and in cytotrophoblast cells of the chorionic plate, basal plate, intercotyledonary septae and cytotrophoblast cells of the chorionic villous tree. (2) Expression of uPA and PAI-2 was noted in villous trophoblast whereas tPA and PAI-1 were mainly concentrated where detachment from maternal tissue occurs. (3) No expression of tPA, uPA, PAI-1 and PAI-2 was observed in the basal plate endometrial stromal cells, chorionic plate connective tissue cells, septal endometrial stromal cells or villous core mesenchyme. (4) The distribution of probes observed following in situ hybridisation is generally consistent with the immunofluorescence pattern of the corresponding antigens and no significant interspecies differences were noted. It is possible that both decidual and extravillous trophoblast cells of placentae of human and rhesus monkey are capable of producing tPA, uPA, PAI-1 and PAI-2 to differing extents. Coordinated expression of these genes in the tissue may play an essential role in the maintenance of normal placentation and parturition. The differences in distribution we observed are consistent with the suggestion that coordinated expression of tPA and its inhibitor PAI-1 may play a key role in fibrinolytic activity in the early stages of placentation and separation of placenta from maternal tissue at term. On the other hand, uPA with its inhibitor PAI-2 appears mainly to play a role in degradation of trophoblast cell-associated extracellular matrix, and thus may be of greatest importance during early stages of placentation.

Animals↗

PubMed1999

Functionally inactive protein C inhibitor in seminal plasma may be associated with infertility.

Protein C inhibitor (PCI) has been found in seminal plasma and is considered to protect intact surrounding cells and seminal plasma proteins from possible proteolytic damage. In the present study, we showed that although the antigenic levels of PCI in two seminal plasma samples from patients with infertility were normal or slightly elevated, their inhibitory activities toward urokinase plasminogen activator (uPA) and tissue-type plasminogen activator (tPA) were absent. In contrast, uPA and tPA proteolytic activities in these two samples were 20-60-fold higher than that from normal volunteers. A time-course analysis of PCI-uPA complex formation showed that >80% of the complex had been formed within 15 min in normal seminal plasma in the presence of heparin, compared with the total complex formed after 150 min incubation, whereas no response to heparin stimulation was observed in the assays with the two patient samples. Similarly, >90% of PCI-tPA complex was formed after 30 min of heparin stimulation in normal seminal plasma but no response was observed in the two patient samples. Kinetic assays of PCI inhibitory function in the presence of activated protein C (APC) showed that PCI inhibitory activity in the two patient samples was absent and not stimulated by heparin. Western blotting also showed that most of the intact PCI molecules, in normal samples, formed complexes with either uPA or tPA but there was no complex formed in one of the two patient samples and very little complex was observed in the other, suggesting that PCI in the two patient samples is inactive. These results suggest that the presence of functionally inactive PCI in seminal plasma may be associated with infertility.

Adult↗

PubMed1999

Expression of the steroidogenic acute regulatory protein and luteinizing hormone receptor and their regulation by tumor necrosis factor alpha in rat corpora lutea.

Expression of both mRNA and protein of the steroidogenic acute regulatory protein (StAR), in correlation with progesterone (P) production and LH receptor (LHR) mRNA expression, was studied in the corpora lutea (CL) of gonadotropin-induced-pseudopregnant and pregnant rats at various stages of CL development. Immature female rats, 21-22 days old, were injected s.c. with 20 IU eCG to stimulate follicle growth and then with 20 IU hCG 48 h later to induce ovulation. The ovaries were removed at various stages of CL development; either CL were isolated and snap frozen for total RNA analysis, or whole ovaries were fixed in Bouin's fluid for paraffin sectioning. The results of in situ hybridization, immunohistochemistry, and Northern blotting showed that the increase in StAR mRNA and protein expression was well correlated with the increase in serum P concentration. StAR expression was restricted to the luteal cells or theca cells in antral follicles. Both StAR mRNA and protein in the CL of pseudopregnant rats increased steadily on Day 1 and Day 4, reached highest levels on Day 4, and then dropped sharply on Day 8 when luteolysis takes place. LHR mRNA content was high on Day 1 but dropped significantly on Day 2. LHR mRNA increased to high levels on Day 4 and 8 and then declined on Day 12. StAR mRNA and protein levels in the CL of pregnant rats were high during early luteal development (Day 2, 4), increased even further on Day 9, and decreased on Day 13 when luteolysis takes place. It is therefore suggested that the expression of StAR coincides well with the capacity of P production in the CL and that StAR expression can be used as a functional "marker" of CL development. To study the possible effect of cytokines on StAR expression, pseudopregnant rats on Day 5 were injected s.c. with 10 IU hCG plus 20 microg prolactin (PRL), with or without 500 IU tumor necrosis factor alpha (TNFalpha) 30 min later. TNFalpha significantly inhibited hCG/PRL-induced StAR and LHR mRNA expression at 1 and 3 h post-TNFalpha. It is suggested that the luteolytic effect of TNFalpha may be mediated by its direct inhibition on StAR expression or by an indirect decrease in LHR expression.

Animals↗

PubMed1998

Risk factors for impaired length growth in early life viewed in terms of the infancy-childhood-puberty (ICP) growth model.

A difference in length or height growth is observed between populations in developing and developed countries and, within a country, between well-off and poor subpopulations. The aim of this community-based study was to identify possible risk factors for growth stunting in early life using the infancy-childhood-puberty (ICP) growth model. A periurban slum, a village and an urban slum, plus a local control group in Lahore, Pakistan, were investigated. In total, there were 425 infants born from September 1984 to March 1987 in the study. Children were followed from birth to 24 months and anthropometric data were recorded at each examination. A well-designed questionnaire was used to collect background information to identify risk factors for growth faltering over this period. The age at onset of the childhood component was determined individually using the ICP growth model. A late onset was defined as onset after 12 months. Univariate odds ratio analysis identified 20 significant risk factors for a delayed childhood onset in the total sample. Backward logistical analysis showed that only six variables were significant, i.e. small number of rooms in a household, episode(s) of diarrhoeal diseases, poor house structure, low body mass index, early end of breastfeeding and birth in warm season. Stratified analysis showed that episode(s) of diarrhoeal diseases and birth in warm season were the only significant risk factors in the two poor areas. This study also found that the impact of diarrhoeal diseases on length growth persisted after allowing for birth season. Seasonal variation in length growth was seen in the age at onset of the childhood component. General socioeconomic status was found to be a risk factor for growth faltering in early life. Diarrhoeal diseases and being born in a warm season are particular risk factors for growth faltering in early life.

Adolescent↗

PubMed1998

Prolactin regulation of tissue type plasminogen activator and plasminogen activator inhibitor type-I gene expression in eCG-primed rat granulosa cells in culture.

The present study was designed to investigate the effect of prolactin (PRL) on plasminogen activator inhibitor-I (PAI-I) and tissue type plasminogen activator (tPA) gene expression in eCG-primed granulosa cells in vitro. At 46 h after the hormone treatment, ovaries were removed, and granulosa cells were prepared for culture. Cells were incubated for various times in serum-free medium in the presence or absence of LH and PRL alone or in combination. tPA and PAI-I activities in the media were assayed by fibrin overlay and reverse fibrin autograph, respectively. Cytoplasmic RNA from granulosa cells was prepared using the NP-40 method and was assayed for PAI-I and tPA mRNA levels. We demonstrated the following. 1) PRL increased PAI-I mRNA production in cultured granulosa cells. Inclusion of LH with PRL had a synergistic effect on increasing PAI-I mRNA levels. After 48-h culture, 3-fold increases in PAI-I mRNA levels were seen with LH in combination with PRL as compared with PRL alone. The synergistic increase in PAI-I mRNA levels occurred in a dose- and time-dependent manner. 2) The increase in PAI-I mRNA synthesis by PRL alone, or by PRL in combination with LH, was well correlated with the changes in PAI-I activity and antigen levels in the conditioned media. 3) PRL in the culture also dramatically decreased LH-induced tPA mRNA and activity in a dose- and time-dependent fashion. The decrease in the tPA activity by PRL was also correlated with an increase in the amount of PA-PAI-I complexes in the cell-conditioned media. 4) In situ hybridization of tPA and PAI-I mRNAs in the cultured granulosa cells also showed that PRL was capable of enhancing PAI-I mRNA while diminishing tPA mRNA production induced by LH. This suggests that the dose- and time-dependent decrease in the gonadotropin-induced tPA activity in the culture by the presence of PRL may be due to decreasing tPA mRNA synthesis on one hand and to neutralization of the tPA activity by the increased PAI-I activity on the other.

Animals↗

PubMed1998

Induction of an intronic enhancer of the human ciliary neurotrophic factor receptor (CNTFRalpha) gene by the TR3 orphan receptor.

A hormone response element, CNTFRalpha-NBRE (5'-AAAGGTCA-3') has been identified in the fifth intron of the alpha component of ciliary neurotrophic factor receptor gene (CNTFR-15) for the human TR3 orphan receptor (TR3). A specific binding between in vitro expressed TR3 and CNTFRalpha-NBRE was demonstrated by using electrophoretic mobility shift assay. A reporter gene assay using chloramphenicol acetyl-transferase (CAT) showed that CNTFR-15 has an enhancer activity that could be induced by TR3 in a dose-dependent manner. This induction was significantly reduced in the absence of CNTFRalpha-NBRE. Together, these results indicate CNTFRalpha-NBRE is sufficient to mediate TR3 action in inducing the enhancer activity of CNTFR-15. Our finding may, therefore, suggest CNTFRalpha is a target gene regulated by TR3 and expand the role of TR3 in the nervous system.

Ciliary Neurotrophic Factor↗

PubMed1998

[Effects of stimulation at different areas of nucleus raphe dorsalis on genioglossus and diaphragm activities].

Effects of electrical and chemical stimulation of the dorsal and ventral areas of the nucleus raphe dorsalis (dNRD and vNRD) on genioglossus and diaphragm activities were observed in 48 urethane-anaesthetized and vagotomized rabbits. (1) Long train electrical stimulation at the dNRD facilitated genioglossus and diaphragm activities. (2) Long train electrical stimulation delivered to the vNRD excited genioglossus activity but inhibited diaphragm activity. (3) Effects of microinjection of glutamate at the dNRD and vNRD were similar to the effects of electrical stimulation. The above results suggest that excitation of nucleus raphe dorsalis (NRD) increases genioglossus activity and reduces upper airway resistance. The dNRD and vNRD play different roles in modulating diaphragm activity.

Animals↗

PubMed1998

Prolactin inhibition of FSH-induced tissue type plasminogen activator expression in cultured rat granulosa cells.

This study was designed to investigate whether prolactin (PRL) affects coordinated regulation of tissue plasminogen activator (tPA) and plasminogen activator inhibitor type-I(PAI-I) gene expression in rat granulosa cells in vitro. Several methods, such as SDS-PAGE, immunoblot etc. were used to detect the effect of PRL on tPA and PAI-I gene expression. The results demonstrated: (1) PRL increases PAI-I mRNA production in cultured granulosa cells. Inclusion of follicle stimulating hormone (FSH) with PRL has a synergistic effect on the increase of PAI-I mRNA levels. After 48 h culture in the presence of FSH with PRL, a 7.8-fold increase in PAI-I mRNA levels is observed as compared with PRL alone. The synergistic increase in PAI-I mRNA levels occurs in a dose- and time-dependent manner; (2) the increase in PAI-I mRNA synthesis in the cells by PRL alone, or PRL in combination with FSH, is well correlated with the changes of PAI-I activity levels in the conditioned media; (3) PRL in culture also decreases FSH-induced tPA activity level in a dose-dependent fashion. The decrease in FSH-induced tPA activity level by PRL is correlated with an increase in the amount of PA-PAI-I complexes in the conditioned media. This suggests that the decline of tPA activity is related to neutralization of tPA by the increased PAI-I activity in the media.

Animals↗

PubMed1998

[Localization and expression of TR3 orphan receptor in mouse testis].

By means of in situ hybridization and immunohistochemistry, the expression and cellular localization of orphan receptor TR3 and its mRNA were observed. The results showed that both TR3 and its mRNA were expressed in a significant amount in mouse testis, and the expression level of TR3 mRNA was different in different seminiferous tubules. TR3 mRNA was specifically expressed in germ cells, mainly in spermatogonia and less advanced primary spermatocytes, whereas TR3 receptor protein was mainly localized in germ cells. It is suggested that TR3 may play an important role in regulating the early stage of germ cell development in mice.

Animals↗

PubMed1998

[An animal experiment and clinical investigation on the protective effect of selenium on the microcirculation induced by free radical damaged RBCs].

UNLABELLED: Fluorescent labeling image analysis was used to evaluate the changes in cerebral arteriole and veinlet diameters (D), circulation velocities (FV) and permeability (VP) in rats; while in clinics, a laser-doppler device was used for assessing changes of skins and muscles microcirculation. The results show that in control rats, equal volume perfusion of free radical damaged RBCs resulted in decreases of D and FV significantly but VP was increased, whereas in the case when free radical damaged RBCs were perfused together with selenium, no disturbances in the D and VP were observed with FV even improved. In the human control group, either average skin microcirculative perfusions (ASMP) at 25 degrees C or maximal skin microcirculative perfusions (MSMP) at 42 degrees C were evidently decreased during myocardial ischemia/reperfusion period, while ASMP at 24th hour of post-surgery was kept reducing. At the same time, the changes in muscles microcirculative perfusions (MMP) tended to be similar to the skin, but overloaded than the pre-surgery levels at 24th hour of post-surgery period. In the selenium group before surgery, the ratio of MSMP to ASMP was obviously increased than the control group (3.95 in Se group vs 1.74 in control group, P < 0.05), but did not have significantly differences in ASMP, MSMP and MMP between the two groups during surgery period. RBC deformabilities were not changed. At 24th hour post-surgery, the ASMP were almost restored to pre-surgery levels. However, MMP were still lower than the pre-surgery levels. CONCLUSIONS: (1) free radical damaged RBC perfusion leads to damage of microcirculation; (2) selenium is highly efficient in protecting microcirculation from free radical damaged RBC disturbance; and (3) Oral administration of selenium may improve pre-surgery maximal skin microcirculative perfusion and promote recovery of the worsened skin microcirculation in addition to prevent the occurrence of RBC deformability.

Adolescent↗

PubMed1997

Temporal expression of urokinase type plasminogen activator, tissue type plasminogen activator, plasminogen activator inhibitor type 1 in rhesus monkey corpus luteum during the luteal maintenance and regression.

Proteolytic activity generated by the plasminogen activator (PA) system has been associated with many biological processes. Using a pregnant mare serum gonadotropin (PMSG)/human chorionic gonadotropin (hCG)-induced rhesus monkey corpus luteum (CL) model, we have studied how urokinase-type plasminogen activator (uPA), tissue-type plasminogen activator (tPA), and plasminogen activator inhibitor type 1 (PAI-1), are temporally expressed in CL of rhesus monkey at the luteotropic and luteolytic periods. Slot blot analysis and in situ hybridization were performed to analyze the expression and distribution of uPA and PAI-1 messenger RNA (mRNA). Fibrin overlay was used to detect uPA and tPA activities. We found that uPA is the dominating PA in luteotropic CL in the monkey. Abundant expression of PAI-1 mRNA was detected. The highest expression of uPA and PAI-1 mRNA was observed at the luteotropic period, while their expression decreased approximately 50% at early luteal regression defined by considerably decreased serum progesterone levels, and remained at very low levels at the late stage of luteal regression. We also observed an increased tPA activity at the time of luteal regression. Moreover, the exogenous tPA could inhibit the progesterone production in cultured luteal cells from 13-day-old monkey CL. We also used LH receptor mRNA expression as a mark for the luteal phases. A highly expressed, evenly distributed LH receptor mRNA was detected in CL during the luteotropic phase, while its expression decreased at day 13 coinciding with the reduction of progesterone production. We conclude that proteolysis mediated by uPA and regulated by PAI-1 may play a role in the luteal maintenance, while tPA may participate in the luteal regression in the rhesus monkey.

Animals↗

PubMed1997

Prolactin delays gonadotrophin-induced ovulation and down-regulates expression of plasminogen-activator system in ovary.

This study was conducted to determine whether prolactin (PRL) suppresses gonadotrophin-induced ovulation and disturbs the co-ordinated gene expression of tissue type plasminogen activator (tPA) and plasminogen activator inhibitor type-1 (PAI-1) in rat ovary. Immature female rats were injected with 10 IU pregnant mare's serum gonadotrophin to stimulate follicle growth, and 48 h received different doses of prolactin followed by 7 IU human chorionic gonadotrophin (HCG). The oviducts were examined for the presence of ova, and the amounts of tPA and PAI-1 mRNA present in the ovary were measured at various times after the hormone treatment. PRL had no significant effect on ovarian weight but caused a dose-dependent decrease in ovulation number. In the control animals receiving HCG alone, 13.3 +/- 1.3 (mean +/- SEM) ova/oviduct were found; while in animals receiving HCG plus 50, 100 or 200 microg PRL, the ovulation number was dose-dependently suppressed by 53.6, 66.9 and 76% respectively at 18 h after treatment. PRL suppression of HCG-induced ovulation was time-dependent. By 24 h after treatment, the number of ova in the oviducts in HCG- and HCG plus PRL-treated groups was not significantly different. PRL also suppressed HCG-induced tPA gene expression in a dose- and time-dependent manner. At all time points examined, tPA mRNA content of whole ovaries and granulosa cells (GC) in PRL-treated groups was lower than in the HCG-treated controls. The activities of PAI-1 in ovarian extracellular fluid (OEF) and PAI-1 mRNA in the theca-interstitial cells (TI) in the PRL-treated groups were higher than in the HCG-treated controls. The highest stimulation by PRL of PAI-1 activity in OEF and of PAI-1 mRNA in TI was observed at 9 h and 6 h after HCG treatment respectively. The localization of tPA and PAI-1 antigens in the ovaries was consistent with changes in the mRNA and activity levels. These data suggest that PRL temporarily delays, but does not completely inhibit, HCG-induced ovulation, which may be caused by a suppression of PA-mediated proteolysis.

Animals↗

PubMed1997

Localization of plasminogen activator and inhibitor, LH and androgen receptors and inhibin subunits in monkey epididymis.

Epididymis is a site of sperm maturation and storage. Limited and directed-proteolysis regulated by plasminogen activator (PA), plasminogen activator inhibitor type-1 (PAI-1) and other related factors may play an essential role in these processes. Our previous studies have demonstrated that rat epididymis expressed luteinizing hormone receptor (LHR), tissue type (t) and urokinase type (u)PA, mRNAs, and tPA activity was stimulated in vitro by human chorionic gonoadotrophin (HCG). In the present study we further examined localization of mRNAs for tPA, uPA, LHR, androgen receptor (AR), as well as inhibin subunits alpha, betaA and betaB in rhesus monkey epididymis. Using in-situ hybridization with digoxygenin-labelled cRNA probes, we have demonstrated that tPA and PAI-1 mRNAs were localized in epithelial cells of adult monkey epididymis. uPA mRNA was localized in the same areas, but to a much smaller extent. tPA, uPA and PAI-1 mRNAs were greatly expressed in the caput and corpus of adult epididymis than in other regions. In-vitro experiments showed that both tPA and uPA activities in epididymal cells were dramatically stimulated by HCG, but not by follicle stimulating hormone (FSH). LHR (but not FSH receptor) and AR mRNAs were localized in the epithelial cells of the epididymis. However, LHR mRNA was detected in both adult and immature infant monkeys, whereas AR was found only in the adult. Inhibin alpha, betaA and betaB mRNAs were also detected in this organ, betaA mRNA being more strongly expressed in the caput than in other regions of the epididymis. We suggest that LH and androgen may be the key hormones in coordination with the PA-PAI-1 system in regulating epididymal differentiation and sperm maturation.

Androgens↗

PubMed1997

Expression of plasminogen activator and inhibitor, urokinase receptor and inhibin subunits in rhesus monkey testes.

The expression and localization of mRNA's for tissue plasminogen activator (tPA), urokinase PA (uPA), uPA receptor (uPAR) and inhibin subunits, alpha, beta A and beta B in monkey testes was investigated. Using in-situ hybridization with digoxigenin-labelled cRNA probes (dig-cRNA), we demonstrated that tPA and plasminogen activator inhibitor type 1 (PAI-1) were expressed in testes of both immature and mature rhesus monkeys. tPA mRNA was localized predominantly in Sertoli cells. Expression level was low in immature testis, increased dramatically in the adult and varied with seminiferous cycle. PAI-1 mRNA was localized mainly in germ cells except late spermatids. uPA mRNA was expressed stage-specifically in Sertoli cells of adult testis. uPA receptor mRNA was localized in germ cells of mature testis but not in spermatogonia or late spermatids. Assayed by fibrin overlay technique, PA activity in conditioned media of purified Sertoli cells (Sc) was negligible, PA activity in media obtained from co-cultured Sertoli and Leydig cells (LS), however, was significantly increased, although Leydig cells alone were not capable of producing any PA activity. Addition of follicle stimulating hormone (FSH) to the incubation medium remarkably increased PA secretion in both Sc and LS cultures. Human chronic gonadotrophin (HCG) had no significant effect on PA activity in the Sc culture but dramatically stimulated PA activity in the co-culture system. Dihydrotestosterone (DHT) did not mimic the effect of HCG. PAI-1 activity was secreted mainly by germ cells and did not differ between the two culture systems. FSH and forskolin inhibited PAI-1 secretion. Inhibin alpha, beta A and beta B subunit mRNAs were localized in Sertoli cells of adult monkey testes, with no obvious difference in the expression levels. These data suggest that PA/PAI-1 and other related factors are expressed in rhesus monkey testis under the control of various hormones, seminiferous cycle and cell-cell interactions through paracrine or autocrine regulation. Locally generated fibrinolysis may play an important role in the process of spermatogenesis.

Animals↗

PubMed1997

Dextromethorphan metabolic phenotyping in a Chinese population.

AIM: To establish a phenotyping of dextromethorphan (DM) oxidation polymorphism in a native Chinese population. METHODS: The urine concentrations of DM and its metabolite dextrophan (DX) were assayed by HPLC and metabolic ratios (MR) were calculated in 120 unrelated native Chinese subjects after ingestion of DM 20 mg. RESULTS: The incidence of poor metabolizers was 0.8% (one in 120 subjects). There were distinct dimodal distributions which divided extensive metabolizers into 43 intermediate metabolizers and 76 very extensive metabolizers. The 0-8 h urinary recoveries of DM and DX were 0.4% +/- s 0.5% and 26% +/- s 13%, respectively. There was no difference in 0-8 h urinary recoveries between male and female subjects. CONCLUSION: DM metabolic phenotyping provides a new information for debrisoquine 4-hydroxylation (CYP2D6) polymorphism in native Chinese.

Adolescent↗