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Biomedical subjects

L C Tang

Publications and source records attributed to L C Tang.

At least 55 records · Page 3Linked to original sources
PubMed1985

The relationship between the human sperm hypoosmotic swelling test, routine semen analysis, and the human sperm zona-free hamster ovum penetration assay.

The functional integrity of sperm membranes of 270 semen samples collected from fertile men and the male partners in couples with infertile marriages was assessed by the hypoosmotic swelling test and the results correlated with routine semen analysis and the human sperm zona-free hamster ovum penetration assay. Semen samples with abnormal semen parameters had lower values of percentage of swollen sperm after hypoosmotic treatment in comparison with those with normal semen parameters. A weak positive correlation was observed between sperm swelling and sperm morphologic features (r = 0.32, P less than 0.05) and between sperm swelling and sperm motility (r = 0.22, P less than 0.05). Insignificant correlation was observed between sperm swelling and in vitro sperm fertilizing capacity, as assessed by the zona-free hamster ovum penetration assay. The results indicate that the sperm swelling test and the zona-free hamster ovum penetration assay are evaluating different functional qualities of sperm that are apparently not associated with each other.

Animals↗
PubMed1985

Cross-sectional study of semen parameters in a large group of normal Chinese men.

Testicular size, semen characteristics and serum reproductive hormone levels were studied in 1239 normal Chinese men. The mean testicular size of 17 ml in this group of subjects was similar to other reports in Orientals but was smaller than that reported in Caucasians. Semen volume, and the sperm count, motility and morphology were comparable to those described for Caucasian subjects. The cervical mucus penetration test (Kremer's test) and the zona-free hamster egg penetration test were also studied in some of the subjects. Age showed a positive correlation with the serum levels of FSH and LH, which were highly correlated with each other. Sperm concentration and the total sperm count were positively correlated with testicular volume, the length of abstinence, the % of sperm with an oval head, and the zona-free hamster egg penetration test, but were negatively correlated with serum FSH. Sperm motility was negatively correlated with the duration of abstinence but was positively correlated with the % normal sperm. The results constitute a normal data base from Chinese men for comparison with studies in male infertility and fertility regulation.

Adult↗
PubMed1985

Rapid urinary LH assay for prediction of ovulation.

The results of the cervical mucus score (CMS), basal body temperature (BBT) and a rapid urine luteinizing hormone (LH) assay by haemagglutination immunoassay were compared with plasma LH radioimmunoassay in 28 ovulatory cycles. There was good correlation of the CMS peak with the plasma LH peak while the urine LH peak usually occurred one day later. The first day when the CMS was greater than or equal to 8 occurred within +/- 1 day of the plasma LH peak in 89.3% of cycles. The first day when the urine LH was greater than or equal to 100 iu/l occurred within +/- 1 day of the plasma LH peak in all the cycles. BBT nadir could be identified in only 82% of cycles and it coincided with the plasma LH peak in only 28.6% of cases. These findings suggest that both the CMS and the rapid urine LH assay are acceptable methods for determining the time of ovulation while the BBT is not useful.

Body Temperature↗
PubMed1985

Aetiological factors in the genesis of pregnancy hydronephrosis.

In order to identify possible aetiological factors in the genesis of physiological hydronephrosis in pregnancy, the degree of pelvic-calyceal dilatation in 90 asymptomatic pregnant women was correlated with levels of plasma oestradiol, progesterone, 24-hour urinary oestriol, the site of the placenta, birthweight of the fetus, and pelvic inlet measurements. A grading system based on maximum calyceal diameter was used; 90% of the patients were found to have at least mild dilatation on the right side. No correlation was demonstrated between the degree of hydronephrosis and the levels of oestradiol, progesterone and 24-hour urinary oestriol excretion. The birth-weight of the fetus and its relationship with the pelvic inlet measurements also did not correlate with the occurrence of hydronephrotic changes in the kidneys. The only significant positive finding was a higher incidence of moderate and severe hydronephrosis occurring in patients with a right-sided placenta than compared with the left (x2 = 4.77; p less than 0.05), although the sensitivity and specificity in predicting hydronephrosis from a right-sided placenta is low (53% and 66% respectively). Our results support the hypothesis of a mechanical aetiology in the genesis of pregnancy hydronephrosis, where vascular compression on the ureters may be an important contributory factor. Our study has also shown that urinary tract infection and reduction of creatinine clearance were not more common in patients with moderate or severe pelvic-calyceal dilatation.

Bacteriuria↗
PubMed1985

Puerperal ovarian vein thrombophlebitis.

A 16 year old Chinese female with puerperal ovarian vein thrombophlebitis following uneventful vaginal delivery is reported. This infrequent, but potentially fatal, complication in the febrile postpartum patient may present as a surgical emergency. Non-invasive diagnostic procedures and conservative treatment with heparinization and antibiotics have been suggested. However, early exploratory laparotomy for ovarian vein or caval ligation may be life-saving if the diagnosis is in doubt or the response to conservative treatment is unsuccessful.

Adolescent↗
PubMed1985

Is fetal femur length a better indicator of gestational age in the growth-retarded fetus as compared with biparietal diameter?

The accuracy of gestational age prediction in 30 growth-retarded fetuses as derived from the fetal femur length (FL) was compared with that derived from the biparietal diameter (BPD). The mean difference between the actual and predicted gestational age was smaller when FL was used, but the difference did not reach statistical significance when compared with that associated with the use of the BPD. No consistent pattern of head/limb growth retardation was obvious. The femur length and BPD were both reduced in varying proportions in the growth-retarded fetuses. The significance of such findings in the assessment of intrauterine growth retardation is discussed.

Cephalometry↗
PubMed1985

Dextropreponderance of corpus luteum rupture. A clinical study.

A retrospective study of 55 consecutive patients with cystic corpora lutea, corpus luteum cysts or hematomas was undertaken to verify the observation of a right-side predominance in the incidence of rupture. Thirty-nine patients had a ruptured corpus luteum diagnosed surgically and confirmed histologically. No difference was observed in the overall distribution, the volume of hemorrhage or the size of the cysts between the two sides. A statistically significantly higher incidence of rupture was found on the right side (81.25%) as compared to the left (56.52%). We propose a working hypothesis of a difference in the ovarian venous architecture that causes a higher intraluminal pressure in the right corpus luteum and the dextropreponderance of ruptures.

Adolescent↗
PubMed1984

Cholinergic agonists stimulate calcium uptake and cGMP formation in human erythrocytes.

Human erythrocytes possess a muscarinic cholinergic receptor sensitive to cholinergic agonists which stimulate transient increases in calcium uptake and subsequent cyclic GMP formation. These phenomena can be blocked by atropine and EGTA. The cholinergic stimulation of cyclic GMP formation depends on Ca2+ uptake from external media. The effects of cholinergic agonists on the erythrocyte resemble their effect on calcium channels in nervous tissue. The cholinergic stimulation of Ca2+ uptake in erythrocytes may affect the calcium-sensitive mechanism involved in the shape, permeability and rigidity of these cells.

Atropine↗
PubMed1984

Atypical presentation of female genital tract tuberculosis.

Three patients with atypical presentation of female genital tract tuberculosis are reported. Tuberculous hydrosalpinx with abdominal peritonitis, concomitant ectopic gestation with active salpingitis and tuberculous endometritis presenting as postmenopausal vaginal discharge are uncommon clinical manifestations. The age distribution, the importance of careful histological examination and the available methods for follow-up are discussed in the appropriate cases.

Adult↗
PubMed1984

Effect of reserpine on fertilizing capacity of human spermatozoa.

The effect of reserpine at various concentrations (2 X 10(-6), 2 X 10(-7), 2 X 10(-8), 2 X 10(-9) and 2 X 10(-10) M) on the in vitro fertilizing capacity of human spermatozoa was studied. Spermatozoa collected from presumably fertile men were washed in BWW medium and incubated with different concentrations of reserpine for 5 hr before insemination of the zona-free hamster ova. The spermatozoal penetration of the zona-free hamster ova was scored 6 hr later and the results were analyzed statistically. Reserpine, at all the concentrations tested, caused a significant dose-dependent decrease in the penetration of the denuded hamster ova in comparison to the control (p less than 0.05). The percent motility of spermatozoa decreased as a function of time during the preincubation period to initiate spermatozoal capacitation but there were no significant differences in the values between the control and the reserpine - treated spermatozoa (p greater than 0.05). These findings indicate that reserpine can affect the fertilizing capacity of human spermatozoa in vitro and provide an additional evidence to suggest the prospective use of reserpine as a vaginal contraceptive.

Adult↗
PubMed1984

Relationships of seminal plasma prolactin with spermatozoal characteristics and fertilizing capacity in vitro.

Seminal plasma prolactin (PRL) levels were determined in 224 semen samples collected from fertile and suspected infertile men, and their relationships with spermatozoal characteristics and fertilizing capacity in vitro were evaluated. PRL concentrations were similar in normospermic and oligospermic samples, but were significantly lower in azoospermic samples. PRL concentrations were significantly higher in samples with high spermatozoal motility than in those with low spermatozoal motility. There were no significant differences in PRL concentrations between normal-morphology and abnormal-morphology samples, and between high-fertilizing capacity and low-fertilizing capacity samples. A low degree of positive correlation was observed between the PRL concentration and the spermatozoal motility. There were no significant correlations between the PRL levels, the other spermatozoal characteristics, and the spermatozoal fertilizing capacity in vitro. These findings indicate that the seminal plasma PRL levels are significantly depressed in azoospermic subjects and suggest that the seminal plasma PRL may play a role in the maintenance of spermatozoal motility. Whether there is a potential function of prolactin in semen on spermatozoal fertilizing capacity, however, cannot be inferred from the present study.

Animals↗