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H S Liu

Publications and source records attributed to H S Liu.

At least 73 records · Page 4Linked to original sources
PubMed1996

Concurrent 5-fluorouracil, daily low-dose cisplatin, and radiotherapy in stage IIIB cervical cancer. A phase II prospective study.

Between June 1987 and May 1991, 30 patients with Stage IIIB cervical cancers were treated using synchronous radiotherapy, 5-fluorouracil (5-FU), and daily low-dose cisplatin. External radiotherapy (3,600-3,960 cGy) was given to the whole pelvis in 4 weeks. Two courses of intracavitary brachytherapy were given 2 weeks later. Parametrial boost was then given. Continuous infusion of 5-FU 750 mg/m2 was given for 5 days during the first and third week of pelvic irradiation. Cisplatin (6 mg/m2) was given 30 min before every irradiation in the second and fourth week. The complete response rate was 87%. The 3-year local control rate was 77%. The 3-year overall and disease-free survival rate was 66% and 56%, respectively. Distant metastases were the major causes of treatment failure. Toxicities were acceptable. Our preliminary results indicate that this synchronous combination treatment is feasible. Further follow-up is required to determine whether this regimen has a genuine favorable impact on survival and chronic toxicity.

Adenocarcinoma↗
PubMed1995

The dependence of glucan conformational dynamics on linkage position and stereochemistry.

The 13C NMR T1 relaxation times for the (1-->4)-linked maltooligomers (Mi) and the (1-->6)-linked isomaltooligomers (IMi) with i = 2, 4, 6, and 8 were measured in aqueous solution at 22 and 65 degrees C at a concentration (3%) low enough to have removed concentration-dependent effects on the measured T1 values. Separate T1 values were measured for each carbon in the residue at the reducing end of the oligosaccharide, in the residue at the non-reducing end, and in the interior, i.e., non-terminal, residue(s). Analogous data for the corresponding high polymers show that at 22 degrees C the relaxation times for the carbons of the interior residues of the oligomers have converged to their high chain length asymptotes at about i = 10. This observation suggests that at room temperature polymeric motions in the frequency domain effective for 13C NMR relaxation at a magnetic field strength of 11.7 T have a "wavelength" of the order of 10 residues. The relaxation times characterizing the two ends of the chain are different, with longer T1 values for the carbons of the reducing end than for those of the non-reducing end. Carbons of alpha-anomeric residues at the reducing end have shorter relaxation times than those of the corresponding beta-anomeric reducing sugars. Carbons of the interior residues have T1 values shorter than the carbons of either type of terminal residue. For oligomers of a given dp there is no T1 difference between oligomers of the Mi and IMi series at room temperature. This observation is seemingly at odds with the great differences in the inherent conformational freedom of the (1-->4)- and (1-->6)-linkages. At elevated temperatures the orientational relaxation behavior of the two series of oligomers measured by 13C T1 values show interesting differences, and in the case of the Mi series, structure develops in the chain length dependence of the T1 values.

Carbohydrate Conformation↗
PubMed1995

Suppression of natural killer cell activity in mouse spleen lymphocytes by several dopamine receptor antagonists.

The effects of dopaminergic receptor inhibitors such as thiothixine (D1/D2), fluphenazine (D1/D2), trifluoperazine (D1/D2), pimozide (D2), flupenthixol (D1/D2), (+/-)-SKF 83566 (D1), and spiperone (D2) on splenic natural killer (NK) cell cytotoxic activities were assessed in vitro using mouse spleen lymphocytes or enriched NK cells. Both the activities of the splenic NK cell cytotoxicity and the effector-target cell conjugation were suppressed by thiothixine, fluphenazine, and trifluoperazine at concentrations from 2.64 to 14.78 microM. In addition, the augmentation of the cytolytic activity of NK cells induced by interferon-alpha or interleukin-2 was antagonized by pretreatment with these neuroleptic compounds. However, neither the splenic NK cell cytotoxicity nor the effector-target cell conjugation were affected by treatment with other neuroleptic compounds such as pimozide, flupenthixol, (+/-)-SKF 83566, and spiperone. Thus, it appears that neuroleptic compounds such as thiothixine, fluphenazine, and trifluoperazine may act through the mechanisms other than a dopaminergic pathway to affect the NK cell-target cell interaction.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1995

Monitoring the cDNA synthesis of dengue-2 virus by RT PCR.

Reverse transcriptase polymerase chain reaction (RT PCR) was utilized to observe the complementary DNA (cDNA) synthesis from the 10723 base dengue-2 virus template by in vitro reverse transcription. The PCR product amplified from 5'-end of the genome (PCR primers N1A-E1) indicates the completeness of the cDNA synthesis because the cDNA primer D8B was located at 3'-end and the cDNA synthesized encompassed the entire RNA template. The integrity of the dengue virus RNA was also determined by the cDNA primer extension from 3'-end and the PCR amplification at various regions from 5'-end of the RNA template. In conclusion, RT PCR could be applied to monitor cDNA synthesis by in vitro reverse transcription and measure the integrity of viral RNA template. Moreover, it is demonstrated that at least 10.7 kilobases of the cDNA could be synthesized from dengue-2 virus RNA by in vitro reverse transcription.

Aedes↗
PubMed1995

Detection of Y-chromosome sequences in patients with X-chromosome abnormalities.

The polymerase chain reaction was used to test 18 adults and eight fetuses with numerical or structural X-chromosome abnormalities for the presence of nine Y-specific loci. Y-chromosomal DNA was detectable in one adult patient with X-chromosome mosaicism. This study and previous reports provide evidence to support further screening of patients with X-chromosome abnormalities for the presence of Y-chromosomal DNA sequences. Long-term follow-up of patients with Y-chromosomal sequences is required to determine the risk of gonadal neoplasms and other abnormal phenotypes.

Adolescent↗
PubMed1995

The preemptive effect of regional anesthesia on post-cesarean section pain.

BACKGROUND: The treatment of post-cesarean section (C/S) pain is very important. Since no previous report discussed the preemptive effect of regional anesthesia on post-C/S pain, the present study was undertaken to evaluate the efficacy of the preemptive effect of regional anesthesia on post-C/S pain. METHODS: Ninety parturients scheduled for C/S were enrolled into one of the three groups (n = 30, per each group). The parturients in group 1 and 2 received spinal anesthesia and epidural anesthesia, respectively, while those in group 3 received general anesthesia for C/S. Postoperative patient-controlled analgesia, by means of intravenous morphine, was used for all paturients to relieve post-C/S pain. The VAS of pain and total morphine consumption were evaluated in all 3 groups of patients. RESULTS: The results showed that groups 1 and 2 consumed less morphine than that of group 3. Also, there was no difference between groups 1 and 2 in the amount of morphine consumed. The incidence of side effects was significantly higher in group 3 than in groups 1 and 2. CONCLUSIONS: We demonstrated that spinal or epidural anesthesia reduced the need of parenteral morphine postoperatively when compared with general anesthesia. We suggest that the use of regional anesthesia may provide a better preemptive effect for post-C/S pain.

Adult↗
PubMed1994

E5a gene of human papillomavirus type 11 is required for initiation but not for maintenance of transformation in NIH 3T3 cells.

We have previously shown that the E5a gene of human papilloma virus type 11 (HPV-11/HPV-6c) is a transforming oncogene. In order to dissect the biological consequences of E5a gene expression we utilized the lac operator/repressor system to manipulate E5a gene expression. Cells were cotransfected with the lac repressor gene and the E5a gene that had been inserted downstream of a simian virus 40 (SV40) promoter containing the lac operator sequence. The expression of E5a gene could therefore be repressed by binding of lac repressor to the lac operator sequence in proximity to this SV40 regulatory region. The transfected cells were cultured in the presence of the inducer IPTG and under G418 selection. IPTG derepressed E5a gene expression by binding to the repressor and reducing its affinity for the lac operator sequence. In these studies, we found that E5a-transformed cells still maintained the transformed phenotype as judged by growth density, cell morphology and anchorage-independent growth when E5a gene expression was repressed. We also found that c-jun expression was induced 3 h after E5a expression was induced by IPTG and c-jun expression was not shut down after repression of E5a expression. This is the first demonstration that the E5a gene of HPV-11 initiates transformation of NIH 3T3 cells but is dispensable for maintenance of the transformed phenotype.

3T3 Cells↗
PubMed1994

The induction of multidrug resistance in human cervical carcinoma cell lines by estrogenic hormones.

The role of estrogenic hormones on the induction of drug resistance was studied in cervical cancer cell lines, SiHa and Caski. After the cells were inoculated with estradiol (E2) or diethylstilbestrol (DES) in various dosages, the cell survival rates with adriamycin treatment were examined by MTT (3-[4,5-dimethyl-thiazole-2-yl]-2,5-diphenyl-tetrazolium-bromide) test and the intracellular accumulation of adriamycin was evaluated by flow cytometry. In the same condition, the expression of multidrug resistance gene-1 (mdr-1 gene) was detected either by Northern blot hybridization for mdr-1 mRNA or by immunoblot for P-glycoprotein 170. The data in this study indicated that estrogenic hormones had the capacity to induce drug resistance in cervical carcinoma cell lines. When cells were treated with estrogenic hormones and adriamycin simultaneously, the intracellular accumulation of adriamycin declined and corresponded with the drug resistance. Since the expression of the mdr-1 gene induced by E2 or DES results in drug resistance, it is suggested that the mdr-1 gene in SiHa cells may contain the estrogenic responsive element (ERE) in its regulatory region. However, the mechanism of drug resistance induced by estrogenic hormones in Caski cells is different from SiHa cells due to the absence of mdr-1 gene expression. Despite that, this experiment may provide a model to investigate the relationships between estrogenic hormones and drug resistance in other female genital cancers.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1994

Establishment and characterization of the transfectable golden hamster embryo fibroblast cell line.

A diploid, continuous cell line, Golden Hamster Embryo Fibroblast-III (GHEF-III), which had been passaged for one year, was established essentially by a 3T3 protocol from primary culture of 14-day-gestation Golden Hamster embryo fibroblast cells. The cultured fibroblast exhibited monolayer growth and had contact inhibition. In morphological identification by light microscope (LM), transmission electron microscope (TEM) and immunofluorescence examination (IF), these multipolar and spindle-shaped cells had a large ovoid nucleus, enriched rER and mitochondria in the cytoplasm. On the other hand, the vimentin presented in the cell with a random network and capped around the nucleus. The results indicated that the cultured GHEF-III cells were fibroblast in origin. The cells were free of bacterial and mycoplasma contamination. The doubling time in GHEF-III was about 15 hours. Chromosomal analysis of GHEF-III presented a diploid stem cell line with a modal number of 44. No evidence of transformation of GHEF-III was shown by properties of contact inhibition, no colony formation in soft agar, and no tumor growth in nude mice. The transformation of GHEF-III after transfection with pT24-C3, an oncogenic plasmid, was shown by the evidence of loss of contact inhibition, growth in low serum medium, colony formation in soft agar and tumor growth in nude mice. In vitro transformation testing of these cells may provide valuable data in studying the role of tumor transforming genes in carcinogenesis. Owing to the genetic stability and less spontaneous transformation, this GHEF-III cell line can be utilized as a source of recipient cells in transfection assay.

3T3 Cells↗
PubMed1994

Using a radioactive and non-radioactive exchangeable labeling system for laboratory diagnosis.

In this communication a safe and simple molecular diagnosis strategy was described, which can be applied for the identification of pathogens or oncogenes in clinical studies. In Southern or Northern analysis, we demonstrated the feasibility to exchange labeling probes from non-radioactive to radioactive or vice versa in a single membrane simply by stripping. We chose non-radioactive labeling because it is safe and easy to operate, but when the sensitivity is insufficient, it can be replaced by radioactive labeling. Our data show that radioactive or non-radioactive labeling is exchangeable in a single membrane and the sensitivity was comparable by either method under optimal conditions. The clinical implication is that for general hybridization starts with non-radioactive labeling, radioactive labeling is not needed unless the signals cannot be detected by non-radioactive labeling. Moreover, one membrane can be labeled repeatedly by different probes.

Blotting, Northern↗
PubMed1993

Reinduction of the hypnotic effects of thiopental with NSAIDs by decreasing thiopental plasma protein binding in humans.

The effects of 14 non-steroidal anti-inflammatory drugs (NSAIDs)--naproxen, ibuprofen, mefenamic acid, ketoprofen, indomethacin, fenoprofen, diclofenac sodium, aspirin, salicylic acid, piroxicam, sulindac, fenbufen, flurbiprofen and benzydamine, on the plasma protein binding of thiopental and the clinical consequences of such interactions were studied. Four of them, naproxen, ibuprofen, salicylic acid and aspirin, very significantly decreased the protein binding of thiopental in vitro in human plasma (P < 0.005). Structurally, they were salicylates and propionic acid derivatives among the six classes of NSAIDs studied. The aspirin study demonstrated that the protein-displacing phenomenon was temperature-dependent, and concentration-dependent. Clinically, aspirin administered intravenously resulted in a significant increase in the percentage of plasma free thiopental from 16.01 +/- 3.59% to 22.27 +/- 3.96% (P < 0.001, n = 10) in patients undergoing surgery, and resulted in three of seven patients sleeping again during recovery from thiopental-induced anesthesia. Although the effect of chronic use of NSAIDs before anesthesia is uncertain, studies should be carried out to find out if naproxen, ibuprofen, and aspirin influence the depth of anesthesia, time of recovery and duration of action of thiopental.

Adult↗
PubMed1993

[Malignant transformation of multiple gastric adenomatous polyps in a teenage girl: a case report].

A 14-year-old female was found to have gastric polyposis by gastroscopy and barium meal study. During operation, multiple polyps in different sizes were noted over the whole stomach, the largest one measured 6 x 6 x 4 cm. The pathological report was adenomatous polyps. After 4 years, the polyps finally transformed to multifocal gastric adenocarcinoma. The relationship between gastric polyps and gastric adenocarcinoma, and the management of gastric polyposis were discussed.

Adenocarcinoma↗
PubMed1992

Control of Ha-ras-mediated mammalian cell transformation by Escherichia coli regulatory elements.

Inducible eukaryotic promoters, particularly those responsive to glucocorticoids or heavy metals, have been extensively used to study the consequences of induction of a target gene in mammalian cells. An alternative approach, intended to improve the selectivity of gene induction and to minimize perturbation of chromatin structure, is to utilize elements from prokaryotic regulatory systems that are unlikely to be shared by mammalian cells. We and others previously have shown that the lac repressor can function in mammalian cells and repress expression of a reporter gene controlled by a eukaryotic promoter containing a lac operator sequence. The reporter gene can be specifically activated by administration of the lactose analogue isopropyl beta-D-thiogalactoside. The target genes tested so far encode the biochemical and histochemical markers, chloramphenicol acetyltransferase and beta-galactosidase. As a model system to establish whether or not the lactose regulatory system can also be used to effectively modulate a cellular phenotype, NIH 3T3 cells were made transgenic for a constitutively expressed lacI gene, encoding lac repressor, and an activated human Ha-ras gene directed by a simian virus 40 promoter within which a lac operator sequence had been embedded. In the absence of inducer, cells were phenotypically untransformed. Consequent to isopropyl beta-D-thiogalactoside administration, four biological end points characteristic of a transformed phenotype were observed. Consistent with transformation, the cells assumed an altered morphology; they displayed a reduced density inhibition of growth; they acquired the capacity to grow in soft agar; and they were released from a G0 block following serum deprivation. The data demonstrate that regulation of gene expression in mammalian cells by the lactose regulatory system affords a sensitive means for modulating cellular phenotype.

3T3 Cells↗
PubMed1991

Reproductive performance following ectopic pregnancy.

The reproductive performance subsequent to operative removal of ectopic pregnancy was examined in 132 women. They represent 44.6% of 296 women admitted for ectopic pregnancy between 1981 and 1989. The follow-up period ranged from 6 months to 9 years, averaging 3.6 years. During the follow-up period, 69 (52.3%) pregnancies occurred. Among them, 60 (87%) were intrauterine and 9 (13% of the pregnant women) were repeated ectopic pregnancies. Full-term delivery was obtained in 73.9% of the pregnant patients. Forty of the 132 patients received conservative surgery and 92 patients received radical surgery for ectopic pregnancy. The operation method had no influence on subsequent fertility in women with an intact contralateral tube, who had significantly higher pregnancy (p less than 0.005) rate (3.8%) than women with an affected contralateral tube (39.5%, 47% and 41%, respectively). Compared with parous women (13.3%), the risk of repeated ectopic pregnancy was similar to nulliparous women (12.5%), but the nulliparous women had a slightly lower conception rate (40%) than parous women (54.8%). Unruptured ectopic pregnancies comprised 41.6% of our cases. There was no significant difference in fertility rate between ruptured and unruptured ectopic pregnancies in our study.

Fallopian Tubes↗
PubMed1991

Neuroendocrine carcinomas associated with squamous cell carcinomas of the uterine cervix: light and electron microscopic observations in two cases.

Small cell carcinomas are rare in cervical cancers and appear to be a heterogeneous group of tumors. Neuroendocrine carcinoma of the cervix, one subtype of small cell carcinomas of the cervix, can be identified by characteristic light and electron microscopic criteria. Two cases of neuroendocrine carcinomas associated with squamous cell carcinomas of the uterine cervix are reported in which electron microscopic studies were performed. The presence of small dense-core membrane-bound granules (120 to 160 nm) in cytoplasmic process under electron microscopic observation confirmed the diagnosis of neuroendocrine carcinoma of the cervix. The coexistence of electron dense-core membrane-bound granules, abundant tonofibrils, and desmosomes within the cancer cells, suggests that these tumors may have derived from the multipotential precursor cells with neuroendocrine and squamous differentiation. Because neuroendocrine carcinomas appear to have the highest incidence of recurrence and the poorest prognosis, it is necessary to distinguish these neoplasms from squamous cell carcinomas of the cervix. Literature about neuroendocrine carcinomas of the cervix is also reviewed.

Carcinoma, Small Cell↗
PubMed1991

[Effect of succinylcholine on recovery of atracurium-induced neuromuscular blockade].

If muscle relaxation is inadequate at the end of surgery, a transient increase in neuromuscular (NM) blockade should be needed to facilitate closure. Succinylcholine is the only agent of short duration available currently and could be used in the just mentioned circumstance. Therefore, the study was designed to investigate the effects of succinylcholine on the recovery of atracurium-induced NM blockade. Sixty-four female patients who underwent elective surgery under general anesthesia were allocated into 6 groups. Before anesthesia, no patient had received drugs which affect NM transmission. In all patients anesthesia was induced with thiopental, diazepam and fentanyl and maintained with 50% nitrous oxide in oxygen and 0.5-1.5% isoflurane. During anesthesia, blood pressure and electrocardiogram were monitored and end-tidal CO2 was maintained at 30-40 mmHg. Control records of the integrated electromyography responded to train-of-four supramaximal stimulation using a Datex Relaxograph were obtained after induction of anesthesia before a block was produced with an initial dose of succinylcholine 1.0 mg in group I (n = 8) or atracurium 0.4 mg/kg in groups II-VI. On first twitch (T1) recovering to 50% of control, 0.4 mg/kg, 0.6 mg/kg, 0.8 mg/kg, 1.0 mg/kg and 1.2 mg/kg of succinylcholine were given in groups II (n = 11), III (n = 14), IV (n = 11), V (n = 10), VI (n = 10) respectively. It was seen that succinylcholine 0.4 mg/kg antagonized NM blockade by atracurium but at 0.6 mg/kg, 0.8 mg/kg, 1.0 mg/kg, 1.2 mg/kg it enhanced that.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Infected cell specific protein and viral DNA synthesis in productive and abortive infections of Spodoptera frugiperda nuclear polyhedrosis virus.

This study examines viral protein and DNA synthesis in Spodoptera frugiperda multicapsid nuclear polyhedrosis virus (SfMNPV) infections of S. frugiperda and Trichoplusia ni cells. A total of 28 infected cell specific polypeptides (ICSPs) were detected in the productive S. frugiperda cells. Of these, 14 were identified as structural polypeptides. Based on the change in their rate of synthesis during the replication cycle, these ICSPs were grouped into four classes. Only a 97k and a 29k ICSP were detected in SfMNPV infections of T. ni cells. Inhibition of host protein synthesis occurred in productive infections only, beginning at 10 h postinfection (p.i.) and reaching maximal levels by 20 h p.i. The rate of viral DNA synthesis in the productive cells was maximal between 8 to 16 h postinfection, and only low levels of viral DNA were synthesized in T.ni cells. The data suggest that the productive SfMNPV/S.frugiperda cell infection has a gene expression program similar but not identical to that of Autographa californica MNPV infections. The SfMNPV/T.ni cell infection is nonpermissive and is restricted at the earliest phase of the viral gene expression program.

Animals↗