Search PubMed⌕ Search

Biomedical subjects

T C Li

Publications and source records attributed to T C Li.

At least 55 records · Page 3Linked to original sources
PubMed2000

Audit standards in ectopic pregnancy.

Due to a combination of increasing public awareness and improved diagnostic techniques, women now present to the clinician early in pregnancy. The majority of women with an ectopic pregnancy are haemodynamically stable. This enables the gynaecologist to consider several management options, such as expectant, medical or laparoscopic surgical treatment rather than just the conventional open surgical approach. This review article examines current literature on the management of ectopic pregnancy and proposes audit standards to be used in the diagnosis and optimal treatment of ectopic pregnancy. It is hoped that this would then enable meaningful audit and review of current clinical practice, leading to improved patient outcome.

Journal Article↗
PubMed2000

Augmentation of immune responses to hepatitis E virus ORF2 DNA vaccination by codelivery of cytokine genes.

DNA vaccines encoding a viral structural protein have been shown to induce antiviral immune responses and provide protection against subsequent viral challenge. In the present study we show that DNA immunization with a plasmid expressing the hepatitis E virus ORF2 structural protein (pcDNA-ORF2) induced low levels of long-lasting antibody responses in the murine model. The use of plasmids expressing interleukin-2 (IL-2) and granulocyte-macrophage colony-stimulating-factor (GM-CSF) in conjunction with pcDNA-ORF2 enhanced the antibody responses generated by pORF-2. We further show that the immune responses generated by plasmid pcDNA-ORF2 can be boosted with virus-like particles composed of the ORF2 protein expressed through a baculovirus expression system.

Animals↗
PubMed2000

Expression of nuclear factor kappa B in human endometrium; role in the control of interleukin 6 and leukaemia inhibitory factor production.

Expression of the rel-A component of nuclear factor kappa B (NFkappaB) by human endometrial cells was investigated by immunocytochemical analysis of cryostat sections cut from endometrial biopsy material and of cultured endometrial epithelial cells. In-vivo expression of rel-A was low in epithelial cells in endometrium obtained during the proliferative phase of the cycle, but increased in these cells during the secretory phase and was maximal at the time of implantation. In-vivo expression of rel-A by stromal cells did not vary greatly throughout the cycle, but showed a slight peak at the time of ovulation. In contrast similar expression of rel-A was seen in short-term cultures of epithelial cells prepared from both proliferative and secretory endometrium. Addition of the NFkappaB inhibitor SN50 (5 microg/ml) to confluent cultures of endometrial epithelial cells inhibited interleukin (IL)-1alpha (10 ng/ml) and tumour necrosis factor alpha (TNFalpha) (10 ng/ml) stimulated IL-6 (P < 0.001 and P < 0.01 respectively) and LIF (P < 0.01 and P < 0.05 respectively) production. The proteasome inhibitor MG132 (0.3 and 3 micromol/l) also caused a dose-dependent decrease in IL-1alpha and TNFalpha-stimulated IL-6 (P < 0.001 and P < 0.001 respectively) and leukaemia inhibitory factor (LIF) (P < 0. 001 and P < 0.001 respectively) production by endometrial epithelial cells. The results support the hypothesis that NFkappaB mediates signalling between IL-1 and TNFalpha receptors and the expression of LIF and IL-6 in endometrial epithelial cells.

Adult↗
PubMed2000

Endocrinological and endometrial factors in recurrent miscarriage.

OBJECTIVE: To investigate the endocrinological and endometrial factors in women with unexplained recurrent miscarriage DESIGN: Prospective, case study SETTING: Recurrent miscarriage clinic, Jessop Hospital for Women, Sheffield PARTICIPANTS: One hundred and forty-four women with unexplained recurrent (> or =3) miscarriages METHODS: A blood sample was obtained in early follicular phase (day 3-5) to measure follicle stimulating hormone, luteinising hormone, prolactin, androgens and thyroid function; daily blood/urine samples were obtained from mid-follicular phase to measure luteinising hormone until the luteinising hormone surge was identified; endometrial biopsy and a further blood sample for progesterone measurement were obtained in the mid-luteal phase. A transvaginal ultrasonography was performed to evaluate ovarian morphology. RESULTS: Hypersecretion of luteinising hormone or ultrasonographic features of polycystic ovarian disease was present in 8% and 7.8% of women, respectively. The free androgen index was elevated in 14.6% of subjects. In the mid-luteal phase, low progesterone level was found in 17.4% and delayed endometrial development was noted in 27.1% of women. Although women with recurrent miscarriage women and delayed endometrium had significantly lower progesterone levels than those with normal endometrial development, only 8/24 had mid-luteal progesterone levels below 30 nmol/L. Recurrent miscarriage was not associated with hyperprolactinaemia or abnormal thyroid function test. CONCLUSIONS: Endocrinological and endometrial abnormalities are present in about a quarter of women with unexplained recurrent miscarriage.

Abortion, Habitual↗
PubMed2000

Analgesic effect of electric stimulation of peripheral nerves with different electric frequencies using the formalin test.

Although electroacupuncture (EA) has been widely used to treat pain, the optimal frequency of EA therapy remains unclear. The study sought to determine the effect of different EA frequencies in a Sprague-Dawley (SD) rat model of pain. Electric stimulation (ES) at frequencies of 2 Hz, 15 Hz or 100 Hz was applied to the ipsilateral or contralateral sciatic nerve of the injected hindpaw of SD rats. Formalin (50 microl, 5%) was subcutaneously injected into the plantar surface of the left hindpaw to induce a nociceptive response. Behavior, including licking and biting, was observed to have two distinct periods, an early phase during the first 5 mins and a late phase from 21-35 mins after injection. The total biting or licking count served as an Indicator of nociceptive response. Our results indicate that ES of the ipsilateral sciatic nerve at a frequency of 2 Hz or 15 Hz reduced the nociceptive responses in both the early and the late phases of the formalin test, whereas ES at 2 Hz had greater antinociceptive effect than ES at 15 Hz in the early phase. No similar analgesic effect in the early phase was observed for ES at 100 Hz. Both pretreatment with ES at 2 Hz and naloxone (3 mg/kg, s.c.) produced a greater antinociceptive response in the late phase than when ES at 2 Hz was delivered immediately after formalin administration. In addition, ES of the neck muscle or contralateral sciatic nerve at a frequency of 2 Hz also decreased licking and biting activity in both phases. The results of this study indicate that different analgesic mechanisms are involved in the response to ES at frequencies of 2 Hz, 15 Hz and 100 Hz, and that ES at 2 Hz has a greater analgesic effect on formalin-induced nociceptive response, especially when it is delivered prior to the onset of pain. The analgesic effect of ES may be mediated via a central origin in the supraspinal level. These findings suggest that 2 Hz may be a good frequency selection for clinical EA applications in analgesia, and that pretreatment with EA at 2 Hz may be an effective method to treat post-operative pain.

Analgesia↗
PubMed2000

The effect of fasting on the pulse spectrum.

Nutrition is the major source of bioenergy. The present study investigated the physiological response to fasting by analyzing the effect of fasting on the pulse spectrum of the radial artery. Sixteen subjects were allowed to take only mineral water for 24 hours, and the pulse was measured at intervals during fasting and after eating resumed. Data were analyzed using one-way analysis of variance (ANOVA) with Scheffe's test for pairwise comparisons. The results indicate the second harmonic of the radial pulse increased and the sixth harmonic decreased significantly after 24 hours of fasting. The proportions of the second harmonic then decreased significantly and those of the sixth harmonic increased significantly 12 hours after eating resumed. These findings suggest that a rhythm exists in physiological changes and the distribution of bioenergy, which ensures that the overall heart load will remain unchanged during the fasting and re-feeding periods, maintaining a stable overall balance in body function.

Adult↗
PubMed2000

A pilot survey of orthodontic awareness among a group of young people in Singapore.

A questionnaire survey was conducted in 1995 on a group of students and their teachers (n = 80) from 3 Independent Schools in Singapore, to assess their orthodontic need, demand, attitude and awareness. Motivational factors and barriers to treatment were also analysed. 36% had orthodontic experience, another 49% perceived need but did not elect to have treatment. Parents and dentists remain the main motivational force behind orthodontic demand. The survey demonstrated high orthodontic utilisation in this group of subjects.

Adolescent↗
PubMed1999

Application of FTA sample collection and DNA purification system on the determination of CTG trinucleotide repeat size by PCR-based Southern blotting.

Myotonic dystrophy (DM) is caused by a CTG trinucleotide expansion mutation at exon 15 of the myotonic dystrophy protein kinase gene. The clinical severity of this disease correlates with the length of the CTG trinucleotide repeats. Determination of the CTG repeat length has been primarily relied on by Southern blot analysis of restriction enzyme-digested genomic DNA. The development of PCR-based Southern blotting methodology provides a much more sensitive and simpler protocol for DM diagnosis. However, the quality of the template and the high (G+C) ratio of the amplified region hamper the use of PCR on the diagnosis of DM. A modified PCR protocol to amplify different lengths of CTG repeat region using various concentrations of 7deaza-dGTP has been reported (1). Here we describe a procedure including sample collection, DNA purification, and PCR analysis of CTG repeat length without using 7-deaza-dGTP. This protocol is very sensitive and convenient because only a small number of nucleate cells are needed for detection of CTG expansion. Therefore, it could be very useful in clinical and prenatal diagnosis as well as in prevalence study of DM.

Blood Specimen Collection↗
PubMed1999

Structural elements common to mitosis and apoptosis.

Both mitotic and apoptotic cells display hypercondensation of the chromatin and loss of the nuclear envelope (Lazebnik et al., 1993). Herein, we describe a third similarity between the two processes. We have observed, initially in apoptotic cells of the PC-12 lineage clusters of 40-60 (approximately 50) nm vesicles adjoined by a minor contingent of tubule vesicular elements of 100-200 nm which are indistinguishable from their vesicular counterparts in mitotic PC-12 cells. The clusters of approximately 50 nm vesicles were subsequently observed in all studied rat tissue cells in apoptosis (plasma cells and macrophages, secretory epithelial cells from pancreatic acini, ventral lobe of prostate and mammary gland). Clusters of approximately 50 nm vesicles comparable to those of the PC-12 cells were found in HeLa cells treated with human alfa TNF, in WEHI-3 cells exposed to VM 26 (a teneposide) (Sesso et al., 1997) and in HL-60 cells treated with thapsigargin. PC-12 and HeLa cells affixed to coverslips were double labelled and examined with the fluorescence microscope to reveal simultaneously the disposition of the chromatin with Hoechst stain and the distribution of the fluorescence of Golgi or of Golgi-associated proteins. A common pattern of fluorescence was observed in a minor proportion of apoptotic cells using three different antibodies used. The label frequently appeared as finely dispersed granules in the cytoplasm. In some apoptotic cells, relatively coarse granules were observed. This pattern of label distribution is compatible with the disposition of vesicular clusters we have encountered in apoptotic PC-12 cells sectioned serially or semi serially. In such sections of both mitotic and apoptotic PC-12 cells, we noticed that the conglomerates of 50 nm vesicles were frequently associated with cisternae of the rough ER. Vesicles of similar size were also noted pinching off from the extremities of Golgi cisternae reduced in size. These cisternae diminish in length and width when they are in the process of disassembling at the very beginning of mitosis and in apoptosis.

Animals↗
PubMed1999

The advisability of implementing cholesterol screening in school-age children and adolescents with a family history of cardiovascular disease and hyperlipidaemia.

BACKGROUND: The family basis of coronary heart disease is well recognized and it is important for family physicians to assess whether children have elevated cholesterol levels. OBJECTIVES: We aimed to evaluate the advisability of implementing cholesterol screening in children with a family history of cardiovascular disease and hyperlipidaemia. METHODS: We conducted a cross-sectional study in Taiwan from February to June 1996. There were 47,800 students in the population. A total of 4520 students were recruited by two-stage sampling. All the participants were required to fill out a structured questionnaire. RESULTS: The response rate was 92.5%. Our results show that 16-18% of the children had a positive family history of cardiovascular disease or hyperlipidaemia. Children with a family history of hyperlipidaemia were significantly more likely to have elevated total cholesterol and low-density lipoprotein cholesterol than those without such a history (both odds ratios: 1.4, P < 0.05). Positive predictive values of hyperlipidaemia were less than 13% based on family history. More than 75% of children with abnormal lipid levels would be missed. CONCLUSIONS: The data suggest that parents' self-reported family history is an ineffective means of identifying children with elevated serum lipid levels in Taiwan. Further research and modification of current National Cholesterol Education Program Panel guidelines for selective cholesterol screening in children may be warranted.

Analysis of Variance↗
PubMed1999

Myomectomy: a retrospective study to examine reproductive performance before and after surgery.

The aim of this retrospective study was to establish the impact of myomectomy on pregnancy outcome with particular reference to its effect on the incidence of pregnancy loss. Myomectomy was performed using microsurgical procedures upon 51 women who had intramural or subserosal fibroids and wished to conceive. Overall, the conception rate following myomectomy was 57%. Multiple regression analysis showed that age was the only factor which influenced conception rate: </=35 years, 74% (23/31); >/=36 years, 30% (6/20; P < 0.005). The pregnancy loss rate prior to myomectomy was 60% (24/40), which was reduced to 24% (8/33) after myomectomy (P < 0.001). There was no instance of premature labour or scar rupture among 25 live births. This retrospective study suggests that myomectomy for intramural and subserosal fibroids may significantly improve the reproductive performance of women presenting with infertility or pregnancy loss.

Abortion, Spontaneous↗
PubMed1999

Epidemiology of hepatitis B, C, E, and G virus infections and molecular analysis of hepatitis G virus isolates in Bolivia.

Prevalence of hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis G virus (HGV), and hepatitis E virus (HEV) was investigated among 574 healthy blood donors in Bolivia. HCV RNA and HGV RNA in the serum were identified by a nested reverse transcription-PCR using primers derived from the 5' untranslated region (5' UTR). We also tested for hepatitis B surface antigen (HBsAg) and for the antibody to HEV. The results revealed that HGV RNA was present in 84 of 574 (14.6%) tested blood donors, whereas HBsAg was detected in only 2 (0.3%) donors, and no individuals positive for HCV RNA were found. Anti-HEV immunoglobulin G (IgG) was detected in 93 (16.2%) individuals and anti-HEV IgM was found in 10 (1.7%) individuals among the same population. Phylogenetic analysis of 44 HGV isolates in the 5' UTR showed that 27 (61%) isolates were genotype 3 (Asian type) and the remaining 17 (39%) isolates were genotype 2 (United States and European type). Moreover, we obtained a full-length nucleotide sequence of the HGV genome (designated HGV-BL230) recovered from a Bolivian blood donor. The BL230 was composed of 9,227 nucleotides and had a single open reading frame, encoding 2,842 amino acid residues. Interestingly, the BL230 belonged to genotype 2 of HGV at the level of a full-length sequence, although this was classified as genotype 3 by a phylogenetic analysis based on the 5' UTR sequence. The BL230 differed from previously reported HGV/hepatitis GB virus type C isolates by 12 to 13% of the nucleotide sequence and 4% of the amino acid sequence. Our data indicate a high prevalence of HGV in native Bolivians, and the major genotype of HGV was type 3.

Adolescent↗
PubMed1999

Changes of pulse rate and skin temperature evoked by electroacupuncture stimulation with different frequency on both Zusanli acupoints in humans.

The purpose of this study was to investigate the effect of electroacupuncture stimulation (EA) of different frequency on pulse rate and skin temperature. Sixteen healthy male medical student volunteers received EA of 2 Hz, and 100 Hz, respectively on the both Zusanli acupoints (St-36) while resting. Their pulse rates were measured on the middle finger, and skin temperature was taken between the thumb and index finger before, during, and after EA stimulation. Each test took 35 minutes. The initial 10 min were defined as baseline period (no EA), the following 15 min as the EA period and the last 10 min as the post-EA period. Three assessments were performed on each subject as follows: A) control assessment: no EA was done throughout the test; B) 2 Hz EA assessment: 2 Hz EA was applied to both Zusanli acupoints during the EA period; and C) 100 Hz EA assessment: 100 Hz EA was applied to both Zusanli acupoints during the EA period. Our results indicate that both 2 Hz EA and 100 Hz EA decreased pulse rates during the EA period, and these changes remained throughout the post-EA period in 2 Hz EA assessment, but not in 100 Hz EA assessment. Both 2 Hz and 100 Hz EA resulted in decreases of skin temperature during the EA period. Our conclusions are that 2 Hz EA and 100 Hz EA applied to both Zusanli acupoints resulted in the decrease of pulse rate, which possibly evoked greater parasympathetic nerve activity on heart beats. 2 Hz EA had a more sustained effect on heart beats than 100 Hz EA. Decreased skin temperatures in the EA period may have resulted from cutaneous vasoconstriction caused by EA induced sympathetic stress response, suggesting EA at least remains for 15 min in clinical application.

Acupuncture Points↗
PubMed1999

Anticonvulsant effect of Uncaria rhynchophylla (Miq) Jack. in rats with kainic acid-induced epileptic seizure.

This study investigated the anticonvulsant effect of Uncaria rhynchophylla (UR) and the physiological mechanisms of its action in rats. A total of 70 male Sprague-Dawley (SD) rats were selected for study. Thirty four of these rats were divided into 5 groups as follows: 1) CONTROL GROUP (n = 6): received intraperitoneal injection (i.p.) of kainic acid (KA, 12 mg/kg); 2) UR1000 group (n = 10), 3) UR500 group (n = 6) 4) UR250 group, received UR 1000, 500, 250 mg/kg i.p. 30 min prior to KA administration, respectively; 5) Contrast group: received carbamazepine 20 mg/kg i.p. 30 min prior to KA administration. Behavior and EEG were monitored from 15 min prior to drug administration to 3 hours after KA administration. The number of wet dog shakes were counted at 10 min intervals throughout the experimental course. The remaining 36 rats were used to measure the lipid peroxide level in the cerebral cortex one hour after KA administration. These rats were divided into 6 groups of 6 rats as follows: 1) Normal group: no treatment was given; 2) CONTROL GROUP: received KA (12 mg/kg) i.p.; 3) UR1000 group, 4) UR500 group, 5) UR250 group, received UR 1000, 500, 250 mg/kg i.p. 30 min prior to KA administration, respectively; 6) Contrast group: received carbamazepine 20 mg/kg i.p. 30 min prior to KA administration. Our results indicated that both UR 1000 and 500 mg/kg decreased the incidence of KA-induced wet dog shakes, no similar effect was observed in the UR 250 mg/kg and carbamazepine 20 mg/kg group. Treatment with UR 1000 mg/kg, 500 mg/kg, or 250 mg/kg and carbamazepine 20 mg/kg decreased KA-induced lipid peroxide level in the cerebral cortex and was dose-dependent. These findings suggest that the anticonvulsant effect of UR possibly results from its suppressive effect on lipid peroxidation in the brain.

Animals↗
PubMed1999

Metalloproteinases and tissue inhibitor of metalloproteinase 1 (TIMP-1) in endometrial flushings from pre- and post-menopausal women and from women with endometrial adenocarcinoma.

The presence of metalloproteinase activity in endometrial flushings obtained from premenopausal women, during the proliferative and secretory phases of the menstrual cycle, control post-menopausal women and women with post-menopausal bleeding (PMB) with or without adenocarcinoma was analysed by zymography. In addition, quantitative measurements of matrix metalloproteinase 2 (MMP-2), MMP-3, MMP-9 and tissue inhibitor of metalloproteinase 1 (TIMP-1) in the flushings were obtained by ELISA. The zymography results showed eight bands of activity, with molecular weights ranging from 51 to 208 kDa in the flushings from pre-menopausal women and post-menopausal women, particularly those with adenocarcinoma. Both zymography and ELISA showed that MMP-2 and MMP-9 were the major metalloproteinases found in the flushings and only low concentrations of MMP-3 were found. Concentrations of MMP-2 in pre-menopausal women were higher in flushings obtained during the secretory phase of the menstrual cycle than those obtained in the proliferative phase (P < 0.05), suggesting that it may play a role in embryo implantation. Concentrations of MMP-2 (P < 0.001), MMP-9 (P < 0.05) and TIMP-1 (P < 0.001) in the flushings from post-menopausal control women were lower than those from pre-menopausal women. Concentrations of MMP-2 (P < 0.05) and TIMP-1 (P < 0.05) were higher in flushings from women with PMB without carcinoma compared with post-menopausal controls and concentrations of MMP-9 (P < 0.01) and TIMP-1 (P < 0.05) in flushings from women with adenocarcinoma were higher than in post-menopausal controls. Among subjects with PMB, concentrations of MMP-9 in women with adenocarcinoma were higher than those without carcinoma (P < 0.05). Our results show that concentrations of MMP-2, MMP-9 and TIMP-1, but not MMP-3, are associated with endometrial activity and, therefore, may have a role in the breakdown of endometrial tissue. In addition, the increased concentrations of MMP-9 in flushings of women with adenocarcinoma indicate that this particular proteinase is associated with the presence of endometrial neoplastic cells.

Adenocarcinoma↗
PubMed1999

Serum leptin levels during the menstrual cycle of healthy fertile women.

Leptin is a protein, produced by adipose tissue, which has cytokine and hormonal properties. Serum leptin levels can be considered as a measure of body fat mass, and are involved in regulation of body weight. Previous studies suggest that leptin may have an additional role in reproduction, and there is also evidence for involvement in the hypothalamic-pituitary-gonadal axis. In this study, we investigate the possible changes in serum leptin concentration throughout the menstrual cycle. Samples were collected from apparently healthy, fertile women at different stages in their menstrual cycle, timed precisely according to the luteinising hormone (LH) surge. Mean serum leptin levels were significantly higher in the luteal phase (median 11.4 ng/mL) than in the follicular phase (median 10.0 ng/mL) (P < 0.001). In addition, mean serum leptin levels correlated with body mass index (r = 0.54, P < 0.05), but showed no correlation with luteal-phase progesterone levels. Results showed that levels of serum leptin vary during the menstrual cycle, and add to the mounting evidence that leptin has a role in reproduction. These fluctuations should be taken into account whenever studies are performed using female subjects.

Adult↗
PubMed1999

Serum cholesterol levels and prevalence of hypercholesterolemia in school-aged Taiwanese children and adolescents: the Taichung Study.

BACKGROUND: Atherosclerosis has become one of the leading causes of death in Taiwan. Hypercholesterolemia is a major risk factor for coronary atherosclerosis. To evaluate the mean total cholesterol values and the prevalence of hypercholesterolemia in school-aged Taiwanese children and adolescents, an epidemiologic survey was conducted. METHODS: After two-stage sampling of 52 primary schools and 26 junior high schools in Taichung City, we randomly selected 3,924 children (2,070 boys and 1,854 girls). Blood total cholesterol (TC), triglyceride (TG) and high-density lipoprotein (HDL)-cholesterol were measured. Response rate was 86.8%. Subjects' ages ranged from seven to 14 years old. RESULTS: From this cross-sectional survey, the following characteristics (mean +/- SD) were documented for boys and girls, respectively: TC, 162 +/- 28 and 165 +/- 29 mg/dl; TG, 74 +/- 33 and 80 +/- 32 mg/dl; HDL-cholesterol, 61 +/- 13 and 59 +/- 12 mg/dl; and low-density lipoprotein (LDL)-cholesterol, 87 +/- 24 and 90 +/- 25 mg/dl. The mean TC across all age groups ranged from 149 to 172 mg/dl for boys and 157 to 170 mg/dl for girls. In boys, the TC concentration was highest at age 11 (172 mg/dl), and in girls was highest at age 7 (170 mg/dl). Borderline hypercholesterolemia (TC > 170 mg/dl) was found in 36.5% of boys (13.5-53.1%) and 39.7% of the girls (28.3-48.6%). Hypercholesterolemia (TC > 200 mg/dl) was found in 9.7% of males (3.1-16.6%) and 10.3% of the females (5.0-14.9%). CONCLUSIONS: The prevalence of borderline hypercholesterolemia was 38.0% for TC and 17.2% for LDL-C, and for hypercholesterolemia, it was 9.9% for TC and 5.8% for LDL-C. The higher TC levels in Taiwanese children were primarily due to higher HDL-C and TG levels.

Adolescent↗