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Biomedical subjects

T C Li

Publications and source records attributed to T C Li.

At least 163 records · Page 9Linked to original sources
PubMed1990

A comparison of some clinical and endocrinological features between cycles with normal and defective luteal phases in women with unexplained infertility.

The luteal phase in a group of women (n = 49) with unexplained infertility was evaluated by improved methods, including the use of the LH surge for precise timing of measurements, quantitative techniques for histological dating of endometrial biopsy and determination of the integrated progesterone concentration in the luteal phase. Overall, 10 out of 49 (20%) women were considered to have a retarded endometrium. The prevalence of retarded endometrium in women with primary infertility (10/37, 27%) was found to be significantly higher (P less than 0.05) than in women with secondary infertility (0/12, 0%). Women with retarded endometrial development had a significantly (P less than 0.01) lower integrated P concentration than those with normal endometrial development; however, of the 10 cases with retarded endometrium, only four were associated with an integrated P concentration below the normal range, whereas the remaining six were associated with an integrated P concentration within the normal reference range, suggesting that an abnormal response of the endometrium is a likely cause of abnormality in these latter cases. There was no difference in age, duration of infertility, follicular phase length, magnitude of the oestrogen surge, magnitude of the LH surge, maximum follicular diameter and luteal phase length between women with a normal or defective luteal phase, defined either by endometrial morphology or integrated progesterone concentration.

Endometrium↗
PubMed1990

A quantitative study of endometrial development in the luteal phase: comparison between women with unexplained infertility and normal fertility.

This study compared endometrial development in the luteal phase of women with unexplained infertility (n = 30) with that in women with normal fertility (n = 70) by the use of quantitative histological techniques (morphometric analysis) on endometrial specimens which were precisely timed from the luteinizing hormone surge. When overall endometrial development (histological dating) was considered, the proportion of women with unexplained infertility who had retarded endometrial development (20%) was found to be significantly higher than for women with normal fertility (3%) (P less than 0.01). When individual histological features were considered, women with unexplained infertility were found to have significant deviation from the normal range established from fertile women in only five of the 14 histological features measured. All of these five features related to the glandular but not to the stromal component of the endometrium; four of these five features are related to glandular secretory activity.

Adult↗
PubMed1990

Ectopic pregnancy.

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Clinical Laboratory Techniques↗
PubMed1990

The interaction of parameters of male and female fertility in couples with previously unexplained infertility.

A prospective study was undertaken of the relationship between semen variables, serial endocrine and follicular ultrasound measurements in one complete menstrual cycle, and the treatment-independent chance of conception for couples who were referred with unexplained infertility. For the 91 couples studied, the mean length of infertility was 70 months. A 100% follow-up rate was achieved. When a stepwise analysis was performed examining semen variables and ultrasonographic and endocrine variables, the mean ratio of salivary progesterone/plasma estradiol between days +1 and +3, with respect to the luteinizing hormone surge and the Grade 2 motile sperm density, were the only variables that achieved the 5% level of significance. There was a highly significant relationship between the product of these two variables and the chance of conception. This study clearly demonstrates an interaction between parameters of male and female fertility.

Estradiol↗
PubMed1989

How precise is histologic dating of endometrium using the standard dating criteria?

Sixty-three endometrial biopsies were dated histologically by using the standard criteria on two separate occasions by the same observer. Overall, it was found that exact agreement occurred in 15 (24%), but disagreement of more than 2 days occurred in 6 (10%). The proportion of exact agreement in the first half of the luteal phase (32%) was found to be significantly higher (P less than 0.05) than that in the second half of the luteal phase (9%). In a separate part of the study, 27 women had two endometrial biopsies, each performed in a separate cycle. The within-subject between-cycle variation of the results of endometrial dating (exact agreement: 4%, disagreement of more than 2 days: 41%) was found to be significantly different from intraobserver variation (P less than 0.01 for both). The amount of intraobserver variation suggests that the traditional dating criteria are not precise enough to quantify corpus luteum function in the second half of the luteal phase, whereas the amount of within-subject between-cycle variation implies that the result of endometrial dating in one cycle cannot be used reliably to predict that of another cycle.

Adult↗
PubMed1989

The endometrial cycle: the expression of a secretory component correlated with the luteinizing hormone peak.

This paper reports the pattern of production and secretion of a secretory phase epitope in the endometrium of 44 normal fertile women. Peroxidase immunochemistry was used to detect the monoclonal antibody D9B1, which binds to a peptide-associated sialylated oligosaccharide, in endometrial biopsies all chronologically dated from the luteinizing hormone (LH) peak. During the proliferative phase, the epitope was shown to be absent from tissue sections. It first made its appearance within gland cells 2 days after the LH peak. By LH+3 a rapid accumulation of the D9B1 epitope was noted in the base of the cell, below the nucleus. On subsequent days, increasing amounts of the antigen were detected in the apical cytoplasm, apparently in a more concentrated form than in the basal cell zone. On day LH+6, around the time of implantation, secretory vesicles in the cell apex were discharged into the gland lumen where the glycoconjugate finally accumulated. This immunohistochemical approach introduces a new parameter for evaluation of endometrial function and could be used to improve the accuracy of histological assessment of the endometrial cycle.

Adolescent↗
PubMed1989

The relation between daily salivary progesterone profile and endometrial development in the luteal phase of fertile and infertile women.

This study analysed the relation between daily salivary progesterone profiles in the luteal phase and endometrial development as assessed by morphometric studies of endometrial biopsies that were timed by luteinizing hormone surge. Among 34 fertile women studied, a threshold relation was noted between cumulative salivary progesterone concentration and 11 of the 17 morphometric features measured, as well as the results of the histological dating. Above the observed threshold, a significant linear correlation was found between cumulative salivary progesterone and the results of histological dating. Among 55 women, progesterone profile in the first half of the luteal phase, but not the second half, was found to be significantly lower in those with retarded endometrial development than in those with normal development. Overall, 50% of retarded endometrial development was associated with a subnormal progesterone profile, but the other 50% was associated with a normal progesterone profile, in keeping with an abnormal response of the endometrium due to progesterone receptor deficiency. Retarded endometrial development was more likely to be associated with a subnormal progesterone profile in the first half of the luteal phase than in the second half.

Adult↗
PubMed1988

Why does RU486 fail to prevent implantation despite success in inducing menstruation?

The administration of RU38486 (RU486) in the luteal phase may induce menstruation, but it may not be associated with shedding of the functional layer of the endometrium. This provides an explanation why, in some cases of successful menstrual induction by RU486, pregnancy continues undisturbed. The ability of RU486 to interrupt a very early pregnancy is more likely to be related to its ability to cause shedding of the endometrium than its ability to induce menstruation.

Adult↗
PubMed1988

A new method of histologic dating of human endometrium in the luteal phase.

Morphometric analysis was performed on 70 endometrial biopsy specimens collected from a population of fertile women. Of the 17 morphometric measurements that were performed on each endometrial biopsy, only 5 were required to achieve a highly significant correlation with chronologic dating based on luteinizing hormone surge (R = 0.99). The result of histologic dating, based on morphometric analysis of endometrial biopsies collected from a separate, unbiased population, correlated strongly and significantly with chronologic dating (r = 0.98, P less than 0.0001). The correlation was better than that achieved when histologic dating was performed according to the conventional dating criteria (r = 0.88, P less than 0.001).

Endometrium↗
PubMed1988

The effects of progesterone receptor blockade in the luteal phase of normal fertile women.

The effects of a single, variable dose (5 to 200 mg) of RU38486 (RU486) (Roussel-Uclaf, Paris, France) in the first half of the luteal phase of the menstrual cycle were studied in 30 normal fertile volunteers. Quantitative histologic techniques were employed, and the results were compared with normal ranges derived from a separate, normal, fertile population. It was found that RU486 inhibited glandular secretory activity, accelerated degenerative changes, induced various vascular changes, increased stromal but not glandular mitotic activity, and did not affect the predecidual reaction. The superiority of morphometric analysis over traditional dating criteria was demonstrated in this study of endometrial responses to an exogenously administered agent. In addition, it was found that temperature drop occurred in 56%, menstrual induction in 43%, luteolysis in 24%, mood change in 23%, and thirst sensation in 3% of women studied. Both menstrual induction and changes in hypothalamic function after the administration of RU486 occurred independently of luteolysis and so were likely to be the direct result of progesterone receptor blockade in these organs. Menstrual induction was significantly related to the dose given and the day on which RU486 was administered. Mood change was significantly related to the day on which RU486 was given. Most of the effects of RU486 occurred around 48 hours after its administration.

Adolescent↗
PubMed1988

An examination of the variation in timed endometrial biopsies.

Endometrial biopsies were obtained from fertile women, aged 20-40 years, with regular cycles of 25-35 days. Chronological dating of the material was carried out by determination of the luteinizing hormone (LH) peak by daily LH assay. Tissue was taken from three or four sites along the biopsy and processed for electron microscopy. Half micron thick sections were analysed by light microscopy and a morphometric examination of the glandular epithelium carried out. Nuclear size was assessed using an unbiased measuring technique and the volume density of the nucleus in the cell was also measured. A series of 12 women was examined, four at each of days LH + 2, 4 and 5. An attempt was made to control a variety of factors which contribute to the variability in the histological dating of the endometrial biopsy. In doing so it was possible to analyse the relative contributions of each sampling level to the overall variance. In contrast to earlier studies there is a relatively small intersubject variation with a correspondingly large within-biopsy variation. These results may indicate that the cellular events in the glandular epithelium, between ovulation and the middle of the luteal phase, are precisely regulated.

Adult↗
PubMed1988

The ultrastructure of the glandular epithelium in the timed endometrial biopsy.

This paper reports the electron microscopic appearance of the uterine glandular epithelium in a group of 25 women of known fertility who underwent endometrial biopsies at known times after the luteinizing hormone (LH) surge between LH + 2 and LH + 6. The use of these well-timed endometrial biopsies enables one to gain a clearer insight into the cellular dynamics of the glandular cells, between ovulation and the middle of the luteal phase. Under the influence of progesterone, the cells are transformed from relatively inactive cells full of free ribosomes to very active polarized cells, containing giant mitochondrial profiles, intracellular deposits of glycogen/glycoprotein-rich material and a complex intranuclear channel system. Intimate associations between organelles develop, the most notable being that between a semi-rough endoplasmic reticulum and the mitochondria. By taking biopsies that are accurately timed, relative to the LH surge, from a group of women of known fertility, the sequences of changes in ultrastructure are established with considerably more precision than was previously available.

Adult↗
PubMed1988

Fetomaternal macrotransfusion in the Yorkshire region. 1. Prevalence and obstetric factors.

The prevalence of fetomaternal macrotransfusion (FMMT), defined as fetomaternal haemorrhage (FMH) greater than or equal to 10 ml, was calculated in a series of 15,724 postpartum Kleihauer tests recorded in six hospitals. The mean prevalence in this retrospective survey, the largest published to date, was 0.83% (SEM 0.22) but values varied according to the technique used to quantify the volume of FMH. A number of obstetric factors that have been suggested as influencing the occurrence and extent of FMMT were examined. The frequencies of these factors in cases with FMMT were compared with those in a control group without FMMT selected from the same population. Manual removal of the placenta (P less than 0.0001) and fetal distress in labour (P less than 0.0001) occurred significantly more frequently in the case group. We are unable to confirm previous reports that other obstetric factors may influence the occurrence and extent of FMMT.

Cross-Sectional Studies↗
PubMed1988

Fetomaternal macrotransfusion in the Yorkshire region. 2. Perinatal outcome.

The perinatal outcome associated with fetomaternal macrotransfusion (FMMT), defined as fetomaternal haemorrhage greater than or equal to 10 ml, was investigated in a study group of 179 cases of FMMT and compared with the outcome in 322 controls selected from the same population. Perinatal mortality and morbidity occurred more frequently in the case group (P less than 0.01). The mean Apgar score at 1 min and the cord haemoglobin level differed significantly between the case and control groups (P less than 0.01) and showed a significant inverse correlation with the estimated volumes of FMMT (P less than 0.0001). There was no significant difference in birthweight between the case and control groups. The mean estimated volumes of FMMT associated with perinatal mortality and with low cord haemoglobin (less than or equal to 9.0 g/dl) were significantly higher than the mean volume in the case group as a whole, which suggests the possibility of adapting these observations to a screening procedure.

Apgar Score↗
PubMed1987

A comparison between two methods of chronological dating of human endometrial biopsies during the luteal phase, and their correlation with histologic dating.

This prospective study was performed on 61 infertile women to examine the correlation between histologic dating using the same criteria by two independent observers and chronological dating by two different methods: (1) determination of luteinizing hormone (LH) peak by daily LH assay, (2) calculation based on the onset of the next menstrual period (NMP). The correlation between histologic dating and chronological dating was found to be significantly better if the LH peak was used to determine the chronological date than if the NMP was used (r = 0.70 and 0.37, respectively).

Biopsy↗