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Biomedical subjects

H C Liu

Publications and source records attributed to H C Liu.

At least 235 records · Page 13Linked to original sources
PubMed1992

Spinal dural arteriovenous anomalies.

The clinical data, radiologic findings, and treatment in 14 cases of spinal dural arteriovenous (AV) anomaly were reviewed. All patients had typical findings of feeding artery, nidus, and draining vein on spinal angiograms. Radiologic diagnosis of spinal AV malformation was first made after myelography in 13 cases and after magnetic resonance (MR) imaging in one case. Thirteen patients underwent embolization; one patient underwent repeat embolization 14 months after the first procedure. The other patient underwent surgical ligation. All patients had clinical improvement after treatment. A high index of clinical suspicion, a complete myelographic examination or an MR image of good quality, and a properly performed complete spinal angiographic study are important for early diagnosis. Embolization may be the treatment of choice. For best results, the feeding artery next to the nidus and the draining vein close to the nidus should be occluded, and the nidus itself should be obliterated.

Adult↗
PubMed1992

Evaluation of Vero cell co-culture system for mouse embryos in various media.

Our objective was to evaluate and compare the efficacy and mechanisms of co-culturing mouse embryos with Vero cells in both Dulbecco's modified Eagle's medium/Ham's F12 (DMEM/F12) and human tubal fluid (HTF) culture medium. Two-cell CB6F1 mouse embryos were cultured either in the presence of Vero cells (group A) or in culture medium alone (group B). In DMEM/F12 significantly more morulae developed in group A than in group B on day 3 (91 versus 23%; P less than 0.01). In contrast, the mouse embryos grew rapidly in HTF and significant differences were noted only in later embryonic stages (on day 5; 86% and 50%, P less than 0.01 of group A and B respectively, hatching or hatched). Similar experiments using DF1 and ICR mouse strains also revealed enhanced embryo development in the presence of Vero cells. To determine whether the embryo-enhancing effects of Vero cells were due to the removal of toxins or to the secretion of embryotrophic factors, ICR mouse embryos were cultured in fresh media with cells (group A), without cells (group B) and in cell-free conditions using cell-conditioned media which were obtained in the presence (group C) or absence (group D) of embryos. These results demonstrated that completion of hatching was highest (52%; P less than 0.01) in group A after 6 days in culture. There were no significant differences between groups B, C and D (rates of total hatching 18, 17 and 17%, respectively). It is concluded that Vero cells improve the development of mouse embryos and this is likely to be due to removal of substances inhibitory to development.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Oxytocin and bovine parturition: a steep rise in endometrial oxytocin receptors precedes onset of labor.

Oxytocin receptors were measured in myometrium and intercaruncular endometrium of cows during pregnancy and parturition. Concentrations of estradiol-17 beta, estrone, and progesterone in peripheral blood were also measured. Receptor concentrations in the endometrium rose almost 200-fold from Day 20 to term (p < 0.0001, ANOVA), from 40 +/- 11 to 7300 +/- 1430 fmol/mg protein. Myometrial receptor concentrations increased 10-fold from 180 +/- 36 fmol/mg on Day 20 to 1850 +/- 360 fmol/mg protein at term (p < 0.0001, ANOVA). During labor, endometrial receptors (6600 +/- 1300 fmol/mg) remained at prelabor values, whereas myometrial receptor concentrations had decreased to 1190 +/- 316 fmol/mg (not significant) and declined further postpartum. Plasma concentrations of progesterone declined from 4-5 ng/ml to about 2 ng/ml between Days 250 and 282 and dropped to < 0.2 ng/ml shortly before delivery. Plasma concentrations of estrone and estradiol-17 beta were below 10-20 pg/ml until Day 230. Estrone concentrations were significantly (p < 0.05) increased by Day 250 and estradiol-17 beta by Day 270, and then both rose rapidly. During labor, plasma estrone was 1135 +/- 245 pg/ml and plasma estradiol-17 beta was 226 +/- 131 pg/ml. The molar ratio of estrone and estradiol-17 beta to progesterone rose from less than 0.01 to 4.4 during labor, and was correlated with oxytocin receptor concentrations in endometrium (r = 0.5160, p < 0.001), but not those in myometrium (r = 0.0122). The regulation of oxytocin receptors by ovarian hormones in the two tissues may therefore differ.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Single photon emission computed tomography using 99Tcm-HMPAO in Alzheimer's disease.

Brain single photon emission computed tomography (SPET) using 99mTcm-hexamethylpropyleneamine oxime (HMPAO) was performed in 37 patients satisfying the standard clinical criteria of Alzheimer's disease (AD), correlating results with patient's age of onset, duration of illness, severity of dementia, neuropsychological impairment, computed tomography (CT) and EEG findings. All patients had abnormal SPET: 23 were bilaterally symmetric, 10 were bilaterally asymmetric and four showed unilateral low regional cerebral perfusion. Low perfusion in bilateral parietal regions was the most consistent finding and was present alone or with other abnormal regions in 31 patients (84%). The only significant clinical correlation was found between asymmetric SPET changes and onset of disease before the age of 65 years. Fifty per cent of patients with presenile onset, but only 19% with senile onset had asymmetric low regional cerebral perfusion. Fifteen of the 36 patients had normal brain CT scans, and 9 of 31 patients receiving EEG examination had normal results. Although clinical evaluation is the most valuable diagnostic tool, brain SPET is a sensitive test for physiological investigation in AD.

Aged↗
PubMed1992

Cerebral infarction in young men with nephrotic syndrome.

BACKGROUND AND PURPOSE: Thrombosis is one of the main complications of nephrotic syndrome; however, cerebral infarction associated with nephrotic syndrome has been rarely reported. SUMMARY OF REPORT: We describe acute cerebral infarction in two young men with nephrotic syndrome. Both had a hypercoagulable state based on hemostatic studies. By retrospectively reviewing the medical records of the past 10 years at our hospital, we found an additional five cases of cerebral infarction with nephrotic syndrome. Two of the patients were found to have nephrotic syndrome during admission for stroke. CONCLUSIONS: Hypercoagulability may be the major contributing factor of cerebral infarction in patients with nephrotic syndrome.

Acute Disease↗
PubMed1992

The application of immunocytochemistry in diagnosis of meningeal carcinomatosis in a patient with unknown primary site.

A 55-year-old female with meningeal signs was suspected to have carcinomatosis meningitis based on cytospin cytology study of cerebrospinal fluid (CSF) with Wright stain. There was no primary site of any malignancy which could be identified as the source of metastasis. Immunochemical staining for cytokeratin and carcinoembryonic antigen on suspicious large immature cells in the CSF gave positive results and confirmed the malignant nature of her disease. Intrathecal chemotherapy with methotrexate and whole brain irradiation then eradicated the symptoms rapidly. Immunocytochemistry was considered to be a very powerful diagnostic tool in management of this patient.

Adenocarcinoma↗
PubMed1992

Tailgut cyst with carcinoid: a case report.

Tailgut cyst, an unusual presacral lesion, is lined by a variety of epithelial types including squamous, columnar, transitional and cuboidal epithelium. Disorganized fascicles of smooth muscle may be seen in the cystic wall. Tailgut cysts are usually multiloculated, and often afflict adult women. In rare cases, adenocarcinoma arises within the tailgut cyst. We present a carcinoid tumor developing from the tailgut cyst. The tumor cells grow in ribbon and festoon patterns and are positive for argyrophilic granules. Immunostains for neuron-specific enolase are also positive. Ultrastructurally, dense-core, membrane-bounded neurosecretory granules are present.

Adolescent↗
PubMed1992

[Squamous cell carcinoma of the gallbladder associated with adenocarcinoma in situ: a case report].

Squamous cell carcinoma of the gallbladder associated with adenocarcinoma in situ of the mucosal columnar epithelium is extremely rare. The case presented here is the first to be documented at the Veterans General Hospital-Taipei. In this case, dysplastic columnar epithelium was discovered alongside with squamous cell carcinoma and squamous metaplasia. Focal adenocarcinoma in situ was also identified. The significance of these associated lesions and the histogenesis of squamous metaplasia and squamous cell carcinoma in gallbladder are discussed.

Adenocarcinoma↗
PubMed1992

Interinstitutional variability of follicle-stimulating hormone and estradiol levels.

OBJECTIVE: To evaluate the variability of follicle stimulating hormone (FSH) and estradiol (E2) results from different laboratories. DESIGN: Prospective analyses of sera separated and frozen, obtained from 15 female patients in the follicular phase. All kits used for radioimmunoassay (RIA) for FSH were from the Second International Reference Preparation (IRP). Four different kits were used for FSH and three for E2. SETTING: Sera obtained from each patient were separated into five test tubes and frozen. Analysis of all samples was done on the same day in each one of five participating hospital-based RIA laboratories (North Shore, Cornell, Yale, Mount Sinai, and Norfolk). PARTICIPANTS: Fifteen consecutive patients from the assisted reproductive technology program at North Shore University Hospital participated in the study. MAIN OUTCOME MEASURES: After FSH and E2 levels were tabulated for each laboratory, mean levels were calculated. RESULTS: Using the Bonferroni adjusted pairwise multiple comparisons analysis, significant differences were found between three groups of laboratories within the FSH results and three different groups within the E2 results. CONCLUSIONS: [1] Different results may be obtained on the same sera for FSH and E2 at different laboratories; [2] for FSH, even though the same IRP is used, different results are reached; [3] for E2, even when the same kits are used, results may be significantly different. These results suggest that specific FSH and E2 levels used to predict chances for achieving a viable pregnancy through in vitro fertilization should be interpreted with caution across institutions.

Estradiol↗
PubMed1992

Cognition and 99Tcm-HMPAO SPECT in Parkinson's disease.

99Tcm-hexamethylpropyleneamine oxime (HMPAO) single photon emission computed tomography (SPECT) of brain was performed in 43 unselected patients with Parkinson's disease to evaluate whether low cerebral perfusion on SPECT correlated with cognitive impairment in the patients. All patients received neurological, Mini-Mental State Examination and a neuropsychological assessment. Eighteen (41.9%) of the 43 patients were demented. Thirty patients (69.8%) had abnormal SPECT: 17 had perfusion defects in cortical regions, eight in basal ganglia and five in both regions. Of the 22 patients with abnormal cortical perfusion, 15 (68.2%) were demented; only three (14.3%) of the 21 patients without cortical defect were demented (P < 0.01). Twelve of the 15 demented patients had low perfusion in the parietal region alone or in parietal and occipital regions. The cortical perfusion defects, present in 22 (51.2%) Parkinson's patients, are highly correlated with cognitive impairment. The pattern of SPECT abnormality in most demented patients with Parkinson's disease is similar to that seen in Alzheimer's disease, suggesting that the underlying pathophysiology for dementia in patients with Parkinson's disease may be similar to that in Alzheimer's disease.

Adult↗
PubMed1991

Choroid plexus tumors in childhood. Histopathologic study and clinico-pathological correlation.

Choroid plexus tumors are rare and account for only 2.3% (8/352) of primary childhood intracranial neoplasms in our series. Most of our patients were under 2 years of age. The tumors had a predilection for the lateral ventricle. Calcification was found in half of these tumors, and ossification was seen in 1 case. Histological features of malignancy including invasion, loss of differentiation, and severe nuclear pleomorphism pointed to a poor prognosis. Such features were found in 2 cases. Neither a large number of mitoses nor necrosis was a constant feature in cases of malignancy. Transthyretin, a marker for choroid plexus tumors, was positive in all cases. However, negative S-100 or positive carcinoembryonic antigen was not necessarily associated with a more aggressive histological pattern. All the papillomas could be totally resected without recurrence, and all the patients with carcinoma died within a few months.

Adolescent↗
PubMed1991

Early pregnancy wastage in IVF (in vitro fertilization) patients.

Human in vitro fertilization is characterized by a low efficiency of implantation. Possible mechanisms for pregnancy loss are discussed. Embryo viability or quality, abnormal implantation, and delayed or absent corpus luteum rescue may all play a role in pregnancy wastage. Defining the possible mechanism for these losses may allow hormonal treatment to correct specific abnormalities.

Abortion, Spontaneous↗
PubMed1991

Effect of aging on phosphate metabolites of rat brain as revealed by the in vivo and in vitro 31P NMR measurements.

Changes of phosphate metabolism in brains of neonate, weaning and adult rats were compared using both in vivo and in vitro nuclear magnetic resonance spectra. Ratios of phosphocreatine/nucleoside triphosphate (PCr/NTP) were the same in neonatal brain in both in vivo and in vitro studies, but not in weaning and adult brains. This discrepancy may have resulted from extended cerebral hypoxia due to slowed freezing of the brain by the increased skull thickness and brain mass in the weaning and adult rats. Variations in in vitro extraction condition for this age-related study may lead to systematic errors in the adult rats. Nevertheless, the phosphomonoester/nucleoside triphosphate (PME/NTP) ratios in extracts of brain from neonatal rats were higher than those obtained in vivo. In addition, the glycerophosphorylethanolamine plus glycerophosphorylcholine/nucleoside triphosphate (GPE+GPC/NTP) ratios, which were not measurable in vivo, showed age-dependent increase in extracts of rat brain. Some of the phosphomonoester and phosphodiester molecules in rat brain may be undetectable in in vivo NMR analysis because of their interaction with cellular components. The total in vitro GPE and GPC concentration in brain from neonatal rat was estimated to be 0.34 mmole/g wet tissue.

Aging↗
PubMed1991

Tumor necrosis factor is present in maternal sera and embryo culture fluids during in vitro fertilization.

The incidence of tumor necrosis factor alpha (TNF) in sera of women undergoing in vitro fertilization (IVF) and in embryo culture fluids was evaluated using an enzyme-linked immunosorbent assay. Just prior to embryo transfer to the uterus, 24 of 49 maternal sera (49.0%) contained TNF. The incidence and range of TNF concentrations (84-920 pg/ml) did not differ between women with eventual successful pregnancies and women who subsequently suffered preclinical or clinical abortions. At 8 days post-embryo transfer, 24 of 56 sera (42.9%) contained TNF. Again, the occurrence of TNF was of no predictive value for the eventual outcome of the pregnancy. TNF was also detected in culture fluids from the in vitro fertilized eggs of 12 of 49 women (24.5%). In 9 women, TNF was detected in each of the embryo culture fluids tested. As was the case for sera, the presence or absence of TNF in the culture fluids was unrelated to pregnancy outcome. In 21 patients, paired sera and culture fluids were analyzed. In 9 of 10 women with TNF in their culture fluids, TNF was also present in the corresponding serum. Of 12 women with serum TNF, 9 also had TNF in their culture fluids. Since the culture fluids contained 10% maternal sera, it appeared that in most cases TNF in the culture fluids was derived, at least in part, from the serum. However, in 6 of 9 women TNF levels in the cultures exceeded levels in the corresponding sera. TNF was also identified in 2 of 10 culture fluids in which Plasmanate was substituted for serum.(ABSTRACT TRUNCATED AT 250 WORDS)

Culture Media↗
PubMed1991

The window of embryo transfer and the efficiency of human conception in vitro.

Women with ovarian failure transferred with donated oocytes provide a unique in vivo model for the elucidation of the window of implantation and efficiency of reproduction in the human. Throughout 52 ovum donation cycles, the temporal window of endometrial receptivity was tested by replacing 2- to 12-cell embryos between days 16 and 24 of hormonally and histologically defined cycles. Of 37 transfers within days 17 to 19, 15 (40.5%) conceptions occurred. Twelve (32.4%) have reached viability. Of 11 patients transferred on days greater than or equal to 20, none conceived. Likewise, no pregnancies were achieved with 4 transfers on cycle day 16. Analysis of multiple embryo transfers within the suggested window of endometrial receptivity (days 17 to 19) revealed 14 of 24 (58.3%) to be conception cycles. considering only transfers with two or more embryos, at least one of which is of high quality (grades 1 to 2), yielded a 63.2% pregnancy rate. The results indicate a very high efficiency for in vitro fecundity provided optimal conditions are attained. The concepts leading to success in the ovum donation model should set the course for continued research toward improving results in other forms of assisted reproduction.

Abortion, Spontaneous↗
PubMed1991

Late luteal estradiol patterns are a better prognosticator of pregnancy outcome than serial beta-human chorionic gonadotropin concentrations.

OBJECTIVE: Since the corpus luteum (CL) is known to play an important role in early pregnancy, its activity could possibly be a marker for pregnancy outcome. DESIGN: The late estradiol (E2) concentration in 48 viable pregnancies and 39 pregnancies which resulted in spontaneous abortions after in vitro fertilization and embryo transfer were used to evaluate such predictability. SETTING: All patients studied were of the Center for Reproductive Medicine at Cornell University Medical College. PATIENTS, PARTICIPANTS: Eighty-seven patients. INTERVENTIONS: None. MAIN OUTCOME MEASURE: Serum E2 and human chorionic gonadotropin (hCG) concentrations on day +11, +13, +15 (day +1 = day of ovum pick-up) were measured and studied. RESULTS: The late luteal CL activity after rescue had a positive correlation with the number and quality of the implanted embryos. Reduced CL activity was indicative of abortion. The late luteal E2 pattern when compared with hCG doubling time had a better abortion predictability (37.8% versus 63.9%, respectively). CONCLUSION: Corpus luteum activity demonstrated to be a better prognosticator of abortion than serial beta-hCG titers.

Chorionic Gonadotropin↗
PubMed1991

A human in vivo model for the luteoplacental shift.

OBJECTIVE: To study the onset of early placental steroidogenesis in humans. DESIGN: Ovarian failure patients who were administered a constant dosage of exogenous estradiol (E2) and progesterone (P) during the luteal phase and early gestation and who conceived after transfer of donated oocytes were used to assess serum hormonal changes throughout early pregnancy. SETTING: Hormonally replaced ovarian failure patients undergoing an egg donation program in an academic research environment. PATIENTS, PARTICIPANTS: Nine human volunteers desiring egg donation. INTERVENTIONS: Replacement of E2 and P. MAIN OUTCOME MEASURE: Serum E2 and P concentrations were measured weekly throughout the patients' gestations. RESULTS: Serum E2 and P levels of these patients remained low in early gestation but significantly increased 25 +/- 1.6 and 34 +/- 1.6 days post embryo transfer, respectively. Regression lines of E2 (r = 0.99; P less than 0.01) and P (r = 0.95; P less than 0.005), intersected basal hormonal levels approximately 3 weeks after transfer. CONCLUSION: This estimate of the onset of placental steroidogenesis is equal to the 5th gestational week as calculated by the patients' last menses, approximately 3 weeks earlier than previously reported.

Corpus Luteum↗