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Biomedical subjects

T T Hung

Publications and source records attributed to T T Hung.

At least 19 recordsLinked to original sources
PubMed2005

Investigating spiritual care perceptions and practice patterns in Hong Kong nurses: results of a cluster analysis.

AIM: Nurses' spiritual care perceptions and practices are explored by identifying profiles of nurses studying in a part-time baccalaureate course in a local Hong Kong university. Relationships between nurses' spiritual care perceptions and their practices are explored. RESEARCH METHOD: Hundred and ninety three nurses completed a structured questionnaire. OUTCOME MEASURES: Spiritual care perceptions and practices. RESULTS: Two-step cluster analysis yielded three clusters. Clusters A, B, and C consisted of 15.0% (n = 29), 44.6% (n = 86), and 40.4% (n = 78), respectively. Cluster A nurses were characterized by relatively negative spiritual care perceptions and practices. Cluster C nurses reported positive perceptions, but negative practices; they mainly chose 'uncertain' for most items on both scales. Cluster B was a large group of nurses holding both positive spiritual care perceptions and practices. Significant differences towards spiritual care were found among clusters. Nurses' perceptions were significant positively correlated with practices (r = 0.62). High positive correlations were found between the two scales (r = 0.83) for nurses in Cluster A, for nurses in Clusters B and C, low positive correlations (r = 0.37) were found. CONCLUSION: Three clusters of Hong Kong nurses were differentiated. They showed differences in the level of their spiritual care perceptions and practices. Despite their level of spiritual care perceptions, nurses seldom incorporated spiritual care practices into their daily nursing care, and the level of spiritual care awareness of some nurses was low. Findings may be used to improve support of nurses, to ensure sensitive spiritual care in their daily practices, and to enhance nursing curricula.

Adult↗
PubMed1996

Uterine polypoid hemangioendothelioma: conservative treatment.

BACKGROUND AND OBJECTIVE: A polypoid uterine hemangioendothelioma was treated by conservative means. STUDY DESIGN/MATERIALS AND METHODS: The diagnosis of hemangioendothelioma was confirmed by histopathology and angiography. The patient desired to retain her fertility; therefore, the hemangioendothelioma was treated by hysteroscopically guided Nd:YAG laser ablation. RESULTS: Five years of follow-up by hysteroscopy and dilation and curettage reveal no evidence of recurrence. The patient continues to have regular menses. CONCLUSION: Conservative management of a uterine hemangioendothelioma by Nd:YAG laser ablation was successful over 5 years of follow-up.

Adult↗
PubMed1996

Treating infertility. Controlled ovarian hyperstimulation using human menopausal gonadotropin in combination with intrauterine insemination.

OBJECTIVE: To determine the effectiveness of human menopausal gonadotropin (hMG) with intrauterine insemination (IUI) for the treatment of various causes of infertility and to identify prognostic factors for the success of this treatment. STUDY DESIGN: Retrospective chart analysis. RESULTS: Of the 271 cycles initiated, 247 were completed in 104 couples, and analysis of these cycles showed that the overall cycle fecundity rate was 10% and the pregnancy rate 22%. The miscarriage rate was 8% and the ectopic pregnancy rate 4%. The multiple pregnancy rate was 29%. For the various causes of infertility, we found that the cycle fecundity rate was 7% for male factor, 11% for oligoovulation, 8% for tubal/pelvic factor, 13% for minimal endometriosis, 18% for mild endometriosis, 17% for moderate endometriosis, 3% for women aged > or = 40 years, 75% for myoma, and 7% for idiopathic infertility. We also found that one IUI timed at 36-48 hours was as effective as two IUIs timed at 18-24 and 36-48 hours after human chorionic gonadotropin (hCG) administration. Poor prognostic factors that were elicited from this study were: (1) failure of pregnancy in three cycles of treatment, (2) female age > or = 40 years, (3) requirement of > 300 IU of hMG daily, and (4) presence of more than eight mature follicles at the time of hCG administration. CONCLUSION: HMC and IUI are effective treatment of some causes of infertility.

Adult↗
PubMed1992

Laboratory and clinical comparison of a rapid versus a classic progesterone radioimmunoassay for use in determining abnormal and ectopic pregnancies.

A rapid, solid-phase, nonextraction progesterone kit (n = 36) was compared with an established extraction method, liquid phase tritium radioimmunoassay for progesterone (n = 79). Logistic regression of the rapid method over the extraction method gave a correlation coefficient of r = 0.968. Logistic regression gave a discriminatory zone (abnormal vs normal pregnancy) of 22.58 ng/ml by the rapid method compared with 15 ng/ml for the extraction method (log Y = 0.253 + 0.936 log X). Similar sensitivity (100% and 100%), specificity (63% and 59%), and predictive values of positive and negative tests (positive predictive value = 91% and 75%, negative predictive value = 100% and 100%) were found using a discriminatory level of 15 and 20 ng/ml for the extraction method (n = 79) and rapid method (n = 76), respectively. Clinically, curettage for patients with values less than these discriminatory zones would have given unacceptable rates for termination of a potentially normal pregnancy (38%). Clinical comparison of abnormal (ectopic or abortion) and normal (term pregnancy) outcomes in two populations of women presenting with first-trimester bleeding revealed that progesterone levels would accelerate the workup in only a small percentage (27%, 15 of 56) of patients with ectopic pregnancies. The rate of ruptured ectopic pregnancies in the observed patients was similar (20%, 3 of 15) to studies using progesterone levels prospectively. Therefore in this retrospective analysis progesterone levels would have given no greater benefit than conventional management.

Abortion, Spontaneous↗
PubMed1989

Fibronectin in reproduction.

The fibronectin (FN) levels in human follicular fluids have been shown to correlate well with follicular size and oocyte maturity, suggesting a role of FN in oocyte maturation. When added to the culture medium, the synthetic peptide Gly-Arg-Gly-Asp-Ser (GRGDS), which specifically inhibits the cell-binding of FN, has been shown to inhibit both spontaneous resumption of meiosis and gonadotropin-releasing hormone-induced meiosis of the oocytes. In another set of experiments, GRGDS has been found to inhibit the in vitro cleavage of mouse embryos by a still unknown mechanism.

Animals↗
PubMed1989

Effects of fibronectin and its peptide fragment on preimplantation mouse embryo.

To investigate the involvement of fibronectin in the early development of mouse embryo, embryos at the two-cell stage were cultured in serum-free Ham F-10 medium with or without fibronectin-related substances. When antibody raised against fibronectin was added at concentrations of 0, 10(-3), 10(-2), and 2 X 10(-2) (vol:vol), the percentages of cells in the blastocyst stage at 72 hours were 88.5%, 67.2%, 48.1%, and 0%, respectively. No inhibitory effects were observed with nonspecific antibody. A low concentration of exogenous fibronectin (up to 0.2 mumol/L) slightly enhanced mouse embryo development after 48 hours. However, a higher concentration (greater than 0.4 mumol/L) of fibronectin inhibited mouse embryo development. A competitive blocker of cell membrane fibronectin receptors, oligopeptide (Gly-Arg-Gly-Asp-Ser), inhibited mouse embryo development in a dose-dependent manner. Meanwhile, control peptide (Gly-Arg-Gly-Glu-Ser-Pro), which does not contain the crucial cell binding sequence, did not show any inhibitory effects. These findings suggest the necessity of endogenous fibronectin-blastomere interaction in early mouse embryo development.

Animals↗
PubMed1989

Artificially induced menstrual cycle with natural estradiol and progesterone.

In order to study the feasibility and efficacy of using natural 17 beta-estradiol (E2) and progesterone (P) to induce endometrial changes, a group of patients with history of premature ovarian failure and bilateral oophorectomy, also interested in the embryo transfer program with donor ovum, were given transdermal E2 (Estraderm, Ciba Pharmaceutical Co., Summit, NJ), and vaginal progesterone suppositories. Serial serum E2, P, follicle-stimulating hormone, and luteinizing hormone were determined by radioimmunoassays. The dosages of E2 and P were adjusted according to the levels of E2 and P so that their changes could follow the same pattern as that of a normal spontaneous menstrual cycle. Serial ultrasonic evaluation of the endometrium and endometrial biopsy during the late luteal phase also was performed. Preliminary data indicated that transdermal E2 patches and vaginal P suppositories, while being as effective in inducing endometrial development for the embryo transfer procedure with donor ovum as synthetic steroids, can also provide a more physiologic approach that may conveniently and safely be extended into the second trimester of pregnancy.

Administration, Cutaneous↗
PubMed1988

The effects of corticotropin, opioid peptides and crude pituitary extract on the production of dehydroepiandrosterone and corticosterone by mature rat adrenal cells in tissue culture.

In order to study the steroidogenic response to pituitary factors, a technique of monolayer tissue culture of mature female rat adrenal cells was used. During the first 24 h, rat adrenal cells produced dehydroepiandrosterone (DHEA) and small amount of corticosterone but in the absence of corticotropin (ACTH), the release of these two steroids were reduced to very low levels. The addition of synthetic alpha-ACTH-(1-24) [0.01-100 ng/ml] elicited a marked increase in the production of both steroids. This stimulating effect was not observed when synthetic methionine and leucine-enkephalins (1-100 ng/ml), human beta-endorphin (1-100 ng/ml) or human beta-lipotropin (1 ng/ml), were added to the culture medium. When these peptides were added concomitantly with alpha-ACTH (1-24) at half of the maximum response dose (1 ng/ml), no synergistic effect upon DHEA and corticosterone production was shown. The addition of crude extract from rat pituitary gland (1-100 ng/ml) with or without alpha-ACTH-(1-24) definitely showed both a stimulatory and synergistic effect upon the production of these two steroids. Furthermore, the ratio between DHEA production and corticosterone production was significantly higher when crude extract of the pituitary gland was given alone or concomitantly with alpha-ACTH(1-24) than when alpha-ACTH(1-24) was given alone. These data suggest the existence of a still undefined pituitary adrenal androgen stimulating which may preferentially stimulate DHEA production over corticosterone production.

Adrenal Glands↗
PubMed1988

Steroid profiles of follicular fluids from a patient with the empty follicle syndrome.

Steroid profiles of follicular fluid obtained from a patient during a cycle in which no oocytes were recovered in 12 follicular aspirates were compared with those of fluid obtained both from cycles of the same patient and from cycles of other patients when oocytes were recovered. Follicles aspirated in the cycle when no oocytes were recovered were shown to be neither atretic follicles, follicular cysts, nor prematurely luteinized follicles. The steroid profile of follicular fluid from the index cycle was characterized by a markedly increased estradiol-to-progesterone ratio and an increased androstenedione level. This, together with a comparison to the steroid profiles of fluid from follicles containing either fertilizable or nonfertilizable oocytes, suggests that the empty follicle syndrome may reflect a dysfunctional ovulation induction.

Androstenedione↗
PubMed1988

Fibronectin and glycosaminoglycans in human preovulatory follicular fluid and their correlation to follicular maturation.

The purpose of this study was to investigate the involvement of two extracellular matrix constituents--fibronectin (FN) and glycosaminoglycans (GAG)--in the development of human ovarian follicles. One-hundred-and-one samples of human follicular fluid (HFF) aspirated from patients participating in an IVF-ET programme were assayed for FN, GAG, protein, progesterone (P) and oestradiol (E2). FN/protein and FN/GAG ratios increased significantly with volume of HFF and with follicular P levels. In contrast, GAG/protein ratios decreased significantly with HFF volume, follicular P and E2. Ratios of FN/protein correlated positively with maturity of oocytes; 3.1 +/- 0.5 with dysmature, 4.2 +/- 0.5 with immature, 8.5 +/- 1.0 with intermediate and 7.8 +/- 0.5 with mature oocytes. Ratios of GAG/protein were inversely correlated with maturity of oocytes; 11.0 +/- 1.0 with dysmature, 12.5 +/- 1.4 with immature, 8.9 +/- 0.9 with intermediate and 9.2 +/- 0.5 with mature oocytes. Ratios of FN/GAG correlated with maturity of oocytes; 0.3 +/- 0.02 with dysmature, 0.4 +/- 0.1 with immature, 1.2 +/- 0.2 with intermediate and 1.1 +/- 0.1 with mature oocytes. Furthermore, follicles leading to oocytes which fertilized showed significantly higher FN/protein and FN/GAG ratios than those yielding oocytes which remained unfertilized. In contrast, GAG/protein ratios were significantly lower in follicles with which oocytes fertilized than in those with oocytes which did not fertilize. These results suggest that FN and GAG can be useful markers for follicular development and the potential of the oocyte to be fertilized.

Adult↗
PubMed1985

Comparison of the effect of 4-hydroxy-4-androstene-3,17-dione on aromatase activity in granulosa cells from preovulatory follicles of rats, rabbits, and humans.

The effect of the aromatase inhibitor 4-hydroxy-4-androstene-3,17-dione (4-OH-A) on the synthesis of estradiol (1,3,5 (10)-estratriene-3,17 beta-diol) by granulosa cells from preovulatory follicles of rats, rabbits and humans was examined. Granulosa cells from all three species were incubated for 4 h without treatment (control) or in the presence of androstenedione (4-androstene-3,17-dione, 0.5 microM), 4-OH-A (5 microM), or both compounds together. Estradiol levels were determined in the medium and cells by radioimmunoassay. In all three species, estradiol synthesis was markedly increased by androstenedione and this increase was blocked by 4-OH-A. In the rabbit, however, 4-OH-A alone caused a small but significant increase in radioimmunoassayable estradiol. The apparent increase seen with 4-OH-A alone may be due to a metabolite of 4-OH-A that cross-reacts in the estradiol radioimmunoassay. With granulosa cells from humans, in which 4-OH-A is of potential therapeutic importance, no similar effect of 4-OH-A alone was observed.

Androstenedione↗
PubMed1985

Inhibition of mouse embryo cleavage by a factor present in the human preovulatory follicular fluid.

Human follicular fluids (hFF) inhibited the in vitro cleavage of mouse embryo and fertilized oocytes. This inhibitory effect occurred at all stages of embryonal development and was reversible at low concentrations of FF. Gel chromatography of FF revealed inhibitory activity in two fractions, corresponding to mol wt of 20,000 and 50,000 daltons. This factor(s) might contain peptide components, since it was activated by heat treatment and trypsin digestion. In spontaneous cycles, late follicular phase hFF had significantly higher inhibitory activity than early follicular phase hFF. There was no significant difference in inhibitory activity of hFF aspirated from patients treated with clomiphene citrate alone, a combination of clomiphene citrate and gonadotropins, or gonadotropins alone. There was a positive correlation between hFF inhibitory activity and hFF estradiol and a negative correlation with progesterone in individual FF samples. These findings suggest that the hFF inhibitory activity of mouse embryo cleavage correlates with the differentiation state of the granulosa cells.

Animals↗
PubMed1984

Plasma beta-endorphin concentrations prior to and during pregnancy, in labor, and after delivery.

Beta-Endorphin was measured by radioimmunoassay in peripheral plasma of nonpregnant women (58 +/- 2.4 pg/ml, n = 17, mean +/- SE), during the first trimester (47 +/- 2.4 pg/ml, n = 11), the second trimester (33 +/- 1.9, n = 11), and the third trimester (49 +/- 2.7 pg/ml, n = 10) of pregnancy, during early (202 +/- 32 pg/ml, n = 12) and advanced labor (389 +/- 78 pg/ml, n = 10), and 30 to 60 minutes post partum (177 +/- 22 pg/ml, n = 12). Mean plasma levels of beta-endorphin were significantly lower in each trimester of gestation than the levels in nonpregnant control subjects. During labor and the early postpartum period, maternal plasma levels of beta-endorphin were significantly elevated. Furthermore, peripheral plasma levels of beta-endorphin during labor fell from 189 +/- 31 to 97.6 +/- 12 pg/ml (n = 13, p = 0.015) in response to epidural anesthesia, as compared to peripheral plasma concentrations of beta-endorphin of 223 +/- 71 and 193 +/- 47 pg/ml prior to and after injection of saline solution into epidural catheters, respectively, in 10 control subjects. Mean plasma levels of beta-endorphin in patients immediately prior to elective repeat cesarean section who were not in labor (151 +/- 23 pg/ml, n = 15) were significantly higher (p less than 0.005) than the levels in third-trimester control subjects. These data indicate that the pain associated with labor and the psychological stress of anticipating an operation are potent stimuli for the pituitary release of beta-endorphin.

Anesthesia, Epidural↗
PubMed1984

Beta-endorphin in pregnancy.

Concentrations of maternal plasma beta-endorphin (beta-EP) as measured by radioimmunoassay decline during pregnancy, reaching a nadir during the second trimester, rise during labor, remain elevated during the early postpartum period and are increased prior to elective cesarean section in the absence of labor. They decline in response to epidural anesthesia during labor and increase during induction of general but not regional anesthesia for cesarean section. Umbilical venous plasma beta-EP levels are not affected by the route or mode of delivery nor the presence or absence of labor, but rise in conjunction with fetal distress. In the presence of fetal distress, umbilical arterial plasma beta-EP levels appear to rise faster than umbilical venous beta-EP concentrations. Amniotic fluid beta-EP levels are higher during the second than third trimester. These data indicate that peripheral plasma beta-EP concentrations reflect stress in both mother and fetus. In the mother, pregnancy itself does not appear to be stressful, whereas pain associated with labor rather than uterine contractions as such increase plasma beta-EP levels. In the fetus, hypoxia and acidosis effectively raise plasma beta-EP concentrations. The origin and physiologic significance of amniotic fluid beta-EP, which appears to be unrelated to fetal maturity, remain to be established.

Adult↗
PubMed1983

Amniotic fluid beta-endorphin and beta-lipotropin concentrations during the second and third trimesters.

Amniotic fluid beta-endorphin (beta-EP) and beta-lipotropin (beta-LPH) were measured by radioimmunoassay after silicic acid extraction and gel chromatographic separation of the two peptides in uncomplicated second-trimester and term pregnancies, in diabetic patients at term, and in pregnancies complicated by Rh-isoimmunization, premature labor, and intrauterine growth retardation. Furthermore, the lecithin/sphingomyelin (L/S) ratios as well as the dehydroepiandrosterone sulfate (DHEA-S) and cortisol levels were determined in most of the amniotic fluid specimens. Both the mean (+/- SE) beta-EP (65.3 +/- 9.1 fmol/ml) and beta-LPH (150 +/- 15.8 fmol/ml) concentrations were significantly higher in the 20 patients with normal pregnancies of 16 to 21 weeks' duration than those found in 21 patients with uncomplicated term pregnancies of 38 weeks' gestation, averaging 42.6 +/- 6.0 and 80.1 +/- 10.7 fmol/ml, respectively. The mean amniotic fluid beta-EP and beta-LPH concentrations measured in the latter subjects were similar to those observed in 23 diabetic patients with otherwise uncomplicated term pregnancies. The mean amniotic fluid beta-EP and beta-LPH levels found in the limited number of patients with Rh-isoimmunization (N = 9), premature labor (n = 8), and intrauterine growth retardation (n = 5) with pregnancies of 24 to 36, 24 to 36, and 34 to 38 weeks' gestation, respectively, were not significantly different from the mean amniotic fluid beta-EP and beta-LPH concentrations of uncomplicated term pregnancies. In all patients but those with Rh-isoimmunization, beta-EP concentrations exhibited a positive correlation with beta-LPH levels. However, the molar beta-LPH:beta-EP ratio was significantly lower at term than during the early second trimester. Neither beta-EP nor beta-LPH correlated with the amniotic fluid L/S ratio and only beta-LPH exhibited a significant inverse correlation with amniotic fluid DHEA-S. The latter was significantly higher in uncomplicated term than second-trimester pregnancies. These results confirm that immunoassayable beta-EP is present in amniotic fluid and declines toward term. These data demonstrate that immunoassayable beta-LPH is present in amniotic fluid and show a more pronounced decrease toward the end of pregnancy than beta-EP. Neither peptide, at least on account of the amniotic fluid levels, appears to be associated with fetal maturation. The physiologic significance of amniotic fluid beta-EP and beta-LPH and their possible role as markers of fetal response to stress remain to be elucidated.

Amniotic Fluid↗
PubMed1983

Evaluation of androgen antagonism of estrogen effect by dihydrotestosterone.

The antagonism of estrogen effect on the immature rat uterus by dihydrotestosterone (DHT) was evaluated in vivo. One-hundred micrograms of DHT which has been shown by previous workers [4] to saturate the androgen receptor but not bind or translocate estrogen receptor was injected daily into immature rats with or without 5 micrograms of 17 beta estradiol (E2) for three consecutive days. The animals were sacrificed on the fourth day, the uteri were excised and the uterine wet weight, cytosol protein content, [3H]-leucine and [3H]-UTP incorporation into TCA-precipitable material, and cytosol and nuclear levels of estrogen and progesterone receptors were measured. When DHT was given in conjunction with estradiol, estrogen induced uterine growth as measured by increases in uterine weight, cytosol protein content, and [3H]-leucine incorporation was significantly reduced. However, cytosol and nuclear concentrations of estrogen receptors and cytosol progesterone receptor concentration were not significantly affected, whereas progesterone treatment significantly reduced estrogen and progesterone receptor concentrations in both the cytosol and the nucleus. DHT administration did not change the binding affinity of the estrogen receptor populations and the ratio between the higher (Kd = 10(-10) M) and lower (Kd = 10(-9) M) affinity components of estrogen receptor remained unchanged. DHT treatment was also shown to significantly reduce estrogen-induced [3H]-UTP incorporation. These findings suggest that the mechanism of DHT antagonism of estrogen effect in this organ system does not involve inhibition of synthesis of estrogen receptor as has been shown for progesterone, but appears to occur by decreasing estrogen-induced RNA transcription at a point subsequent to estrogen receptor binding.

Androgens↗