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Biomedical subjects

T C Li

Publications and source records attributed to T C Li.

At least 73 records · Page 4Linked to original sources

Association between serum uric acid and cardiovascular risk factors among elderly people in Taiwan.

In order to understand the distribution of serum uric acid and the relationship between serum uric acid and the cardiovascular risk factor among elderly people, a cross-sectional study was conducted in Chung-Shing-Shin-Tseun community in Taiwan in May 1998. All individuals aged 65 and over were collected. A total of 1123 persons, out of 1774 registered residents, were contacted by face-to-face interview. The response rate was 63.3%. However, only 586 respondents had blood tests and completed questionnaires. Analysis in this study was based on these 586 subjects. The mean uric acid values were 7.4 +/- 1.8 mg/dl in men and 6.3 +/- 1.6 mg/dl in women, respectively (p < 0.001). Multivariate linear regression showed that serum uric acid was significantly correlated with sex and body mass index. Simple correlation showed that serum uric acid was significantly correlated with diastolic pressure, total cholesterol, triglyceride and creatinine. Age, systolic pressure and fasting glucose were not related to serum uric acid. In our conclusion, the uric acid values are high among elderly people. The serum uric acid levels are significantly associated with the cardiovascular risk factors among elderly people.

Age Factors↗

Serum androgen levels in women who have recurrent miscarriages and their correlation with markers of endometrial function.

OBJECTIVE: To compare plasma androgen concentrations in women who have recurrent miscarriages and in fertile women, and to correlate the results with concentrations of the endometrial protein PP14 in uterine flushings and plasma from women who have recurrent miscarriages. DESIGN: Retrospective study. SETTING: Hospital research unit. PATIENT(S): Women attending a recurrent miscarriage clinic and normal fertile volunteers. Ten of the women with recurrent miscarriages had polycystic ovary disease (PCOD) as assessed by ultrasonography or increased follicular LH levels. INTERVENTION(S): Plasma samples were obtained from the women on days LH-7, LH-4, LH+0, and LH+7 or LH+10 of a cycle. An endometrial flushing sample and a biopsy specimen were taken from women with recurrent miscarriages on day LH+7 or LH+10. MAIN OUTCOME MEASURE(S): Androstenedione, testosterone, and sex hormone-binding globulin (SHBG) were measured in the plasma samples. The endometrial protein PP14 was measured in the uterine flushings and in the LH+7 or LH+10 plasma samples from the women with recurrent miscarriages. RESULT(S): Testosterone concentrations were higher in the women with recurrent miscarriages both with and without PCOD on days LH-7 and LH-4 of the cycle. Concentrations of androstenedione also were higher in the women with recurrent miscarriages, but without PCOD on day LH-7. Testosterone SHBG ratios were higher in the women with recurrent miscarriages, without PCOD compared with the controls on days LH-7, LH+0, and LH+7. Mean follicular testosterone concentrations were correlated negatively with both uterine (r = -0.47) and plasma (r = -0.49) PP14 levels on day LH+10. Mean luteal phase testosterone SHBG ratios were correlated negatively with uterine PP14 concentrations on day LH+7 of the cycle (r = -0.674). CONCLUSION(S): Androgen levels are higher in women who have recurrent miscarriages than in normal fertile controls. These high levels of androgens may have a detrimental effect on endometrial function.

Abortion, Habitual↗

The prevalence of continuing chronic pelvic pain following a negative laparoscopy.

This is a retrospective study to assess the prevalence of continuing symptoms in women following a negative laparoscopy for chronic pelvic pain. The case-notes of 347 laparoscopies were reviewed. Of the 189 laparoscopies in which the indication for the procedure was chronic pelvic pain, 67 were found to be negative. This group of patients were each sent a questionnaire asking about continuing symptoms. The results of the questionnaire show that 48% of patients remain dissatisfied with their clinical care, 53% continue to require regular analgesics for their pain, 43% feel that their quality of life had been affected in a major way and 30% admit to feeling depressed in a major way due to their symptoms. This data would suggest that despite a negative laparoscopy for chronic pelvic pain, a significant percentage of patients would benefit from continuing medical input in order to help deal with their symptoms.

Journal Article↗

Is the measurement of placental protein-14 and CA-125 in plasma and uterine flushings useful in the evaluation of peri-menopausal and post-menopausal bleeding?

In this prospective study, we examined the possible diagnostic value of the measurement of two endometrial proteins, placental protein-14 (PP14) and CA-125, in the evaluation of pre- and post-menopausal bleeding. Concentrations of these two proteins were measured in plasma and uterine flushings obtained from 139 pre- and post-menopausal women with bleeding problems, and 26 normal post-menopausal control women without bleeding. Endometrial biopsy samples were also obtained for histological study. Concentrations of PP14 in both the plasma and uterine flushings in post-menopausal women were significantly lower (P < 0.001) than those of control pre-menopausal women. In post-menopausal women, the concentrations of PP14 (mean +/- SEM) in both plasma and flushing were significantly higher (P < 0.001) in women with endometrial adenocarcinoma (46.9+/-7.5 ng/ml plasma; 3350+/-1711 ng/ml flushing) than in the controls (7.6+/-1.3 ng/ml plasma; 125+/-27 ng/ml flushing) or in women with post-menopausal bleeding and atrophic endometrium (20.4+/-2.1 ng/ml plasma; 453+/-167 ng/ml flushing). In contrast CA-125 concentrations in plasma and flushings were similar in post-menopausal and pre-menopausal women. Plasma concentrations of CA-125 were higher in post-menopausal women with adenocarcinoma (29.1+/-7.4 IU/ml) than in those with post-menopausal bleeding and atrophic endometrium (21.8+/-2 IU/ml) (P < 0.05) or control post-menopausal subjects (16.1+/-2.1 IU/ml) (P < 0.01). CA-125 concentrations in uterine flushings were not significantly different in any group of post-menopausal women. The results show that concentrations of PP14 are correlated more strongly to endometrial histopathology than those of CA-125 in pre- and post-menopausal women. Elevated PP14 concentrations are also associated with the presence of endometrial adenocarcinoma and may have a potential to be used as a marker for this disease.

Adenocarcinoma↗

Endometrial protein PP14 and CA-125 in recurrent miscarriage patients; correlation with pregnancy outcome.

The concentrations of endometrial proteins PP14 and CA-125 were measured in uterine flushings taken on days LH+10 and LH+12 (10 and 12 days after luteinizing hormone surge) of the menstrual cycle from 15 normal, fertile women and 49 women who suffered recurrent miscarriage. The concentration of PP14 was significantly lower in the flushings from the recurrent miscarriage patients than in those from fertile controls on both day LH+10 (median: 1300, range: 3-10 300 ng/ml versus median: 13 933, range: 2174-40 404 ng/ml; P < 0.01) and LH+12 (median: 1560, range: 820-12 100 ng/ml versus median: 14 047, range 1402-62 108 ng/ml; P < 0.05). Similarly concentrations of CA-125 were significantly lower in flushings from recurrent miscarriage women compared to controls on both day LH + 10 (median: 1555, range: 47-6710 U/ml versus median: 6385.5, range 2884-27 731 U/ml, P < 0.01) and LH+12 (median: 2892, range: 956-9974 U/ml versus median: 7127.5, range: 1591-21 343 U/ml; P < 0.05). In contrast there was no significant difference in the concentration of PP14 in plasma samples taken on the same days as the flushings from recurrent miscarriage patients and fertile controls. The concentrations of PP14 in uterine flushings obtained on day LH + 10 or LH + 12 from recurrent miscarriage women during a pre-pregnancy investigative cycle were significantly lower (P < 0.05) in patients who went on to miscarry (median: 1000, range: 9-2900 ng/ml) than those who went on to have a live birth (median: 1440, range: 4-12 100 ng/ml) during a subsequent pregnancy. In contrast there was no significant difference in uterine CA-125 or plasma PP14 concentrations between these two groups of recurrent miscarriage patients. The results suggest that measurements of uterine PP14 and CA-125 may be useful in the assessment of endometrial development in recurrent miscarriage patients and suggest the importance of PP14 in preparing the endometrium for embryo implantation. In addition pre-pregnancy uterine PP14 measurements may be useful in predicting subsequent pregnancy outcome.

Abortion, Habitual↗

The value of biochemical and ultrasound measurements in predicting pregnancy outcome in women with a history of recurrent miscarriage.

In this study, the potential prognostic value of serial ultrasonographic, endocrinological and biochemical measurements in the early pregnancy of women with a history of unexplained recurrent miscarriage was examined. A total of 113 pregnancies among 93 women were studied, of which 77 (68%) resulted in live birth, whereas 36 (32%) ended in a miscarriage. The normal range (5-95th centile) of various measurements was derived from pregnancies which resulted in a live birth. Among the 36 failed pregnancies, 42% had one or more human chorionic gonadotrophin (HCG) measurements, 35% had one or more gestation-sac diameter measurements, 33% had one or more embryonic heart rate measurements, 20% had one or more crown-rump length measurements and 9% had one or more placental protein 14 measurements below the normal range, a week or more prior to the confirmation of miscarriage. Altogether, 22/36 = 61% of the failed pregnancies could have been predicted on the basis of one or more of the measurements below the normal range.

Abortion, Habitual↗

Recurrent miscarriage: principles of management.

Recurrent miscarriage is a heterogeneous condition which has many possible underlying causes. Ideally, couples with the problem should be managed in a dedicated miscarriage clinic, with thorough investigations according to a protocol, with structured history and investigation sheets. Counselling is an important feature and may be provided by a specially trained counsellor, or specialized nurse appropriately trained in counselling. Counselling should include an explanation of the possible underlying causes of the condition, and of the prognosis of each of the conditions. There is no definite cause of miscarriage in approximately half of the patients. No treatment is needed in this group, apart from reassurance and tender loving care. Treatment of unproven value, for example progesterone support in early pregnancy, should not be offered. Treatment offered empirically or as part of a research project should have a sound scientific and statistical basis, and should include careful counselling with informed consent of the patient. There are many controversial issues in the management of recurrent miscarriage; consequently, there is a need for locally agreed guidelines for management. Women who conceive again should be offered regular monitoring, including serial ultrasonography in the first trimester of pregnancy. An active audit programme to review regularly the various outcome measures set against defined targets should be established in the clinic.

Abortion, Habitual↗

A prospective randomized controlled study comparing the morphological and biochemical responses of the endometrium to two different forms of 'period-free' hormone replacement therapy.

Thirty postmenopausal women were randomized to receive either continuous combined (cc) 2 mg oestradiol valerate and 0.7 mg norethisterone acetate hormone replacement therapy (HRT) daily (15 women) or tibolone 2.5 mg daily (15 women) and were monitored to determine the relationship between the two biochemical markers placental protein 14 (PP14) and the glycoprotein CA125, endometrial histology and occurrence of irregular bleeding after 12 months of treatment. The concentrations of PP14 and CA125 in plasma and uterine flushings before and after therapy were measured and their concentrations were associated with the histology of endometrial biopsies obtained on the same day as venesection and endometrial flushing. The levels of PP14 in uterine flushings were significantly increased after the administration of both types of HRT (P < 0.05 for tibolone and P < 0.001 for ccHRT). However, the concentrations of PP14 found in flushings after ccHRT were considerably greater than those found in flushings after tibolone; levels were increased about 150-fold by ccHRT and 6-fold by tibolone (P < 0.001). Plasma concentration of PP14 after both types of HRT were also significantly raised to a similar degree (P < 0.01). In contrast, the concentration of plasma and uterine CA125 were unchanged by either treatment. Histological analysis of the endometrium from women after 12 months of HRT treatment showed that 86% (6/7) of women on ccHRT had secretory activity as compared to 44% (4/9) women on tibolone (P < 0.05). Women with higher post-HRT uterine PP14 concentration were more likely to have irregular bleeding (P < 0.05). Our studies have shown that endometrial PP14 but not CA125 concentrations are raised to a significant degree by two different forms of period-free HRT regimens. Increased PP14 concentrations in uterine flushing may suggest endometrial stimulation of some form and predict the predilection to irregular bleeding. Thus uterine PP14 concentrations may be used to monitor endometrial responses in women on HRT.

CA-125 Antigen↗

Profile of cytokine mRNA expression in peri-implantation human endometrium.

The human embryo and subsequent fetus is a semi-allograft and immunologically foreign to the mother. Successful embryonic implantation and maintenance of normal pregnancy depends on intricate interactions between the invading embryo, maternal endometrium and maternal immune response. Cytokines are pivotal in determining the type of maternal T-helper immune response, which can be divided into T-helper 1 (TH1)-mediated delayed hypersensitivity and T-helper 2 (TH2)-mediated humoral immunity. We examined the pattern of TH1 [interleukin (IL)-2, IL-12 and interferon-gamma] and TH2 (IL-4 and IL-6) cytokine expression in the peri-implantation endometrium of 10 fertile, multiparous women. Endometrial samples were timed to the mid-cycle luteinizing hormone (LH) surge, with collection on days LH+7 to LH+9. Analysis for cytokine mRNA was by mRNA extraction and reverse transcription-polymerase chain reaction. The results show a lack of TH1 and predominant TH2 cytokine expression. We postulate that endometrial cytokines may contribute to the local modulation of maternal adaptive immune response in peri-implantation endometrium, to facilitate successful embryonic implantation and maintenance of pregnancy.

Adult↗

Factors affecting the outcome of laparoscopic ovarian drilling for polycystic ovarian syndrome in women with anovulatory infertility.

OBJECTIVE: To describe and analyse the factors affecting the pregnancy rate of laparoscopic ovarian drilling for polycystic ovarian syndrome in women with anovulatory infertility. DESIGN: A retrospective study. SETTING: A specialist infertility clinic based at a teaching hospital in England. POPULATION: One hundred and eighteen women, for whom hospital records and follow up data were available, with polycystic ovarian syndrome who underwent laparoscopic ovarian surgery for anovulatory infertility over a five year period, between January 1991 and December 1995. MAIN OUTCOME MEASURES: Ovulation and pregnancy rate. RESULTS: The cumulative conception rate 12 months after the treatment was 54%. Women who conceived following the surgery had a shorter duration of infertility, were treated with diathermy (rather than laser), had higher pre-operative luteinising hormone levels, were younger and were more likely to have ultrasonographic evidence of polycystic ovarian disease. Logistic multiple regression analysis showed that the duration of infertility, modality used in treatment (laser or diathermy) and the pre-operative levels were the main determinants of the outcome. CONCLUSION: Women with polycystic ovarian syndrome respond favourably to laparoscopic ovarian drilling. The success rate in women with infertility duration of less than three years, treated with diathermy, in whom the pre-operative level was more than 10 IU/L reached 79%.

Adult↗

Cerebral cortex participation in the physiological mechanisms of acupuncture stimulation: a study by auditory endogenous potentials (P300).

Although acupuncture has traditionally used the acupoints formula to treat diseases, the physiological mechanisms involved and the effectiveness of therapy remain unclear. This study investigated the physiological mechanism(s) and response to acupuncture stimulation using the acupoints formula. Scalp-recorded potentials P300 were evoked by auditory stimulation of non-target and target in 13 normal adult volunteers. Latencies and amplitudes were measured. Three assessments were performed in each subject over a period of at least one week. Each assessment was divided into a control period with no acupuncture stimulation, followed by an acupuncture period and then a post-acupuncture period. Acupuncture needles were inserted into the body as follows: 1) non-acupoint: acupuncture needles were inserted 2 cm lateral to both Zusanli acupoints; 2) acupoint: acupuncture needles were inserted into both Zusanli acupoints; 3) acupoints formula: acupuncture needles were inserted into both Zusanli and Shousanli acupoints. Our results showed that both acupoint and acupoints formula assessments resulted in a significant decrease of P300 amplitudes during the acupuncture and post-acupuncture periods. However, there was significant difference in P300 amplitudes in the non-acupoint assessment during these periods. P300 changes in latencies and amplitudes were not significantly different between the acupoint assessment and the acupoints formula assessment. We concluded that acupuncture stimulation of both Zusanli acupoints resulted in a decrease of P300 amplitudes, suggesting the involvement of the cerebral cortex in sensory interaction when simultaneous sensations of the two types are received. No similar changes were observed in the non-acupoint assessment, which have been suggested to be related to so-called acupoint specificity. Results obtained using the acupoints formula were not significantly different from those using acupoints alone. These findings suggested that neuropsychological effects from stimulation of Zusanli acupoints and Shousanli acupoints are different.

Acoustic Stimulation↗

[Changes of mitogen-activated protein kinase activity in cardiac tissues, Ang II and cardiac hypertrophy in spontaneously hypertensive rats].

Mitogen-activated protein kinases (MAPKs) are thought to be critical components in signal transduction pathways in regulation of cell growth and differentiation. The purpose of the present investigation is to study possible involvement of MAPKs in the progress of cardiac hypertrophy in spontaneously hypertensive rats (SHRs) and effects of age on Angiotensin II (Ang II), MAPK activity and cardiac hypertrophy. The animals were divided into three groups: 4 months old WKY rats (n = 8), 4 month old SHRs (n = 8) and 15 month old SHRs (n = 6). Ratio of heart to body weight was measured. Ang II was determined by RIA. MAPK activity in cardiac tissue was assayed by the "in-gel" myelin basic protein phosphorylation. The results show that in comparison with 4 month old WKY rats, Ang II in plasma and cardiac tissues were elevated (216.4%, P < 0.01; 101.2%, P < 0.01) in 4 months old SHRs, while the MAPK activity was increased 107.0% (P < 0.01) with a parallel cardiac hypertrophy (P < 0.01). In comparison with 4 month old SHRs, Ang II and MAPK activity in cardiac tissue of the 15 months old SHRs were decreased (31.3%, P < 0.01; 29.7%, P < 0.05) but the cardiac hypertrophy increased by 38.5% (P < 0.01). MAPK may be involved in the progress of cardiac hypetrophy in SHR and the increased MAPK activity may be partly induced by Ang II.

Angiotensin II↗

Reversal of sterilisation vs. IVF: a cost-benefit analysis.

A consecutive series of 132 cases of reversal of sterilisation carried out in a teaching hospital in England between 1982 and 1995 was analysed. Follow-up data was obtained on 112 patients. The overall cumulative conception rate was 47% at 12 months and 55% at 24 months. Among the 71 pregnancies there were seven miscarriages (9%) and 11 ectopic pregnancies (15%). Factors affecting the outcome of surgery were examined. The pregnancy rate achieved with microsurgical techniques was significantly higher than the conventional (macrosurgical) techniques (61% v. 40%, P = 0.05). The method of sterilisation also has a significant impact on the outcome; Filshie clips 69%; Fallope ring 46%; Pomeroy technique 31% (P < 0.05). Age, associated infertility factors and the interval between sterilisation and reversal operation did not appear to have a significant impact on the outcome. When compared with IVF, reversal of sterilisation is associated with a higher ectopic rate, lower multiple pregnancy rate and a lower miscarriage rate. We conclude that reversal of sterilisation carries a higher overall success rate than IVF and is more cost effective when the method of sterilisation is by the clip or ring and when the reversal operation is carried out with microsurgical techniques.

Journal Article↗

The production of leukaemia inhibitory factor by human endometrium: presence in uterine flushings and production by cells in culture.

The concentration of leukaemia inhibitory factor (LIF) was measured in uterine flushings obtained from normal fertile women, from women with unexplained infertility and from women who suffered recurrent miscarriage. In normal fertile women, LIF was not detected in flushings obtained on days luteinizing hormone (LH)+0 to LH+6 of the cycle, but concentrations gradually increased from day LH+7 to a maximum at day LH+12. The amount of LIF in flushings obtained from women with unexplained infertility was significantly lower than in those from normal fertile women on day LH+10 (P < 0.05). The production of LIF by cultured human epithelial and stromal cells was also investigated. LIF was not detectable in the supernatants of cultured stromal cells. Basal LIF production by epithelial cells varied according to the stage in the cycle at which the biopsy was taken. Significantly more LIF was produced by epithelial cells from late proliferative and early secretory endometrium compared with amounts produced by cells from early proliferative (P < 0.001) and late secretory (P < 0.01) endometrium. High doses of progesterone and oestradiol caused a small decrease in epithelial cell LIF production: the combined effect of progesterone and oestradiol (P < 0.01) was greater than the effect of either steroid alone (P < 0.05). The results show, for the first time, the capability of human endometrium to produce LIF in vivo. The fact that maximum LIF concentrations are present at implantation and that decreased concentrations occur in women with unexplained infertility suggest the importance of this cytokine in embryo implantation.

Cells, Cultured↗

The effect of a single dose of mifepristone (RU486) on the fine structure of the human endometrium during the early luteal phase.

This study examined the fine structure of the human endometrial glandular epithelium after the administration of a single dose of RU486 (mifepristone), given in the early luteal phase. The drug was administered on days 2, 3, 5 and 6 after the luteinizing hormone peak (LH + 0). Biopsies were performed on days LH + 5, 6, 8 and 9. These were compared with control biopsies taken on corresponding days. Qualitatively, the main cytological effect of the RU486 was on the secretory apparatus and on the polarity of the cell. The formation of the nuclear channel system was also affected by the drug. A two-way analysis of variance on cell and nuclear volume data revealed no significant effect of day of biopsy, condition or interaction. Mitochondrial volume and secretory apparatus volume data revealed a significant effect of day of biopsy and interaction term; mitochondrial volume at LH + 5 was 95.9 +/- 25.3 microm3 (mean +/- SD) for control and 57.7 +/- 31.9 microm3 for RU486-treated epithelium. The volume of the secretory apparatus in the treated group was smaller on days LH + 5 and 6 (14.6 +/- 4.2 microm3, 6.41 +/- microm3) when compared to day-matched control biopsies (35.9 +/- 10.5 microm3, 41.7 +/- 26.4 microm3). RU486 administration in the early luteal phase disrupted the secretory activity of the cells. These findings provide an insight into the cellular mechanisms of progesterone receptor blockade in the peri-implantation period.

Adolescent↗

Stability of serum interleukin-10 levels during the menstrual cycle.

PROBLEM: Menstrual cycle-associated variability in the circulating levels of several cytokines can be a confounding factor in measurements of in vivo cytokine levels in clinical studies. Since pregnancy-associated increases in interleukin-10 (IL-10) levels are well documented, we have investigated the variability in serum levels of IL-10 in healthy women at different stages of the menstrual cycle to ascertain whether this is a problem in comparative studies of circulating IL-10 levels. METHOD OF STUDY: We obtained fifty-four successive serum samples at points in the menstrual cycles of 12 healthy fertile women, precisely timed by measurement of the luteinizing hormone surge, and measured the interleukin-10 levels. RESULTS: Levels of IL-10 in successive serum samples from each woman taken on days LH - 7 (that is seven days prior to LH surge), LH - 4, LH + 1, LH + 7, and LH + 10 showed that IL-10 does not vary in a systematic way during the menstrual cycle. CONCLUSION: These results validate the sampling of women in studies of IL-10 levels in various clinical situations and establish that these levels are not dependent on menstrual cycle dates. They also suggest that menstrual cycle-related changes in IL-1 are not mediated by IL-10. The rise in progesterone in the luteal phase of the menstrual cycle is not mirrored by a rise in the circulating IL-10 level, which implies either that the pregnancy-associated rise is not related to progesterone or that it is only observed at the higher progesterone levels in pregnancy.

Adult↗

Expression and self-assembly of empty virus-like particles of hepatitis E virus.

Hepatitis E virus (HEV) is a pathogenic agent that causes fecally-orally transmitted acute hepatitis. The genome, a single-stranded positive-sense RNA, encodes three forward open reading frames (ORFs), in which an approximately 2-kb structural protein is located in the 3' end. To produce HEV-like particles the structural protein, with its N terminus truncated (amino acid residues 112 to 660 of ORF2), was expressed in insect Tn5 cells by a recombinant baculovirus. In addition to the primary translation product with a molecular mass of 58 kDa, a large amount of a further-processed molecule with a molecular mass of 50 kDa was generated and efficiently released into the culture medium. Electron microscopic observation of the culture medium revealed that the 50-kDa protein self-assembled to form empty virus-like particles (VLPs). The buoyant density of the VLPs in CsCl was 1.285 g/cm3 and their diameter was 23.7 nm, a little smaller than the 27 nm of native HEV particles secreted into the bile or stools of experimentally infected monkeys. The yield of the VLPs was 1 mg per 10(7) cells as a purified form. The particles possess antigenicity similar to that of authentic HEV particles and, consequently, they appear to be a good antigen for the sensitive detection of HEV-specific immunoglobulin G (IgG) and IgM antibodies. Furthermore, the VLP may be the most promising candidate yet for an HEV vaccine, owing to its potent immunogenicity.

Animals↗