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M L Wang

Publications and source records attributed to M L Wang.

At least 73 records · Page 4Linked to original sources
PubMed1993

[Effects of lung- and liver-derived biomatrices on the attachment and growth of tumor cells].

The attachment and growth property of a human carcinoma cell line (Anip), which has high pulmonary metastatic potential, were investigated in vitro on the lung- or liver-derived biomatrix in culture medium supplemented with serum (SSM) or free of serum (SFM). Either in SFM or SSM, the carcinoma cells showed a higher rate of adhesion to the lung biomatrix than that to the liver biomatrix, In SFM, cells plated on plastic plates ceased proliferating and died; whereas those on the biomatrices, particularly the cells on the lung biomatrix survived and proliferated. Moreover, in SSM, carcinoma cells on the lung biomatrix had the highest clonal growth efficiency. These results indicate that biomatrices may provide conditions favourable for cell growth, and may compensate in part the deficiency of nutrition and growth factors when serum is absent in the culture medium. The different influences exerted on the growth and attachment rate of tumor cells by biomatrices derived from different organs also help to clarify the mechanism of organ specificity of tumor metastasis.

Adenocarcinoma↗
PubMed1993

Detection of renal allograft dysfunction with color Doppler flow ultrasound.

Thirty-six color Doppler flow (CDF) ultrasound studies were performed on 28 allograft kidneys to assess the capability of this technique in diagnosing transplant dysfunction through morphology and Doppler spectra. The composite score obtained from ultrasound images showed no statistical significance. Quantitative studies with Pulsatility Index (PI) and Resistive Index (RI) after localization of the arcuate, interlobar, segmental and main renal arteries by CDF revealed significant differences between normal functioning graft kidneys and the group of acute rejection, as well as the group of acute tubular necrosis (ATN) (P < 0.05). No apparent change was demonstrated in patients with chronic rejection. When PI was greater than 1.60 or RI was greater than 0.80, the transplant kidney was more likely to be rejected, though possibility of ATN should be considered. RI was easier to calculate, and correlated better than PI with the serum creatinine level. CDF expedited the Doppler spectrum study.

Adult↗
PubMed1992

Construction of a chromosome-enriched HpaII library from flow-sorted wheat chromosomes.

We report here the first successful generation of a chromosome-enriched library from flow sorted plant chromosomes. Chromosomes with a characteristic DNA content (a peak) were sorted from a synchronized cell culture (TaKB1, derived from Triticum aestivum). A HpaII library was constructed from the sorted chromosomes and half of the cloned DNA sequences analysed are unique or low copy. Approximately half of these sequences when used as probes detect sequences on wheat chromosome 4A. The generation and analysis of the chromosome library is described in detail and the prospects of using flow-sorted plant chromosomes discussed.

Cells, Cultured↗
PubMed1992

Vasorelaxing effect in rat thoracic aorta caused by fraxinellone and dictamine isolated from the Chinese herb Dictamnus dasycarpus Turcz: comparison with cromakalim and Ca2+ channel blockers.

The components of Dictamnus dasycarpus Turcz were tested for their vasorelaxing effect on the rat aorta, and fraxinellone and dictamine were shown to be effective vasorelaxants. In high K+ (60 mmol/l) medium, Ca2+ (0.03 to 3 mmol/l)-induced vasoconstriction was inhibited concentration-dependently by both agents. The IC50 for fraxinellone and dictamine were calculated to be about 25 mumol/l and 15 mumol/l (for Ca2+ concentration of 1 mmol/l), respectively. Cromakalim (0.2-10 mumol/l) relaxed aortic rings precontracted with 15 but not 60 mmol/l of K+. Fraxinellone and verapamil were more potent and effective in producing relaxation in 60 mmol/l than in 15 mmol/l K(+)-induced contraction. However, dictamine was more potent in producing relaxation in 15 mmol/l K(+)-induced contraction. Nifedipine (1 mumol/l), dictamine (100 mumol/l) and fraxinellone (100 mumol/l) relaxed the aortic contraction caused by KCl or Bay K 8644. The tonic contraction elicited by noradrenaline (NA, 3 mumol/l) was also relaxed by dictamine (500 mumol/l), but not by fraxinellone (500 mumol/l) in the nifedipine (1 mumol/l)-treated aorta. This relaxing effect of dictamine persisted in endothelium-denuded aorta. Glibenclamide (10 mumol/l) shifted the concentration-relaxation curve of cromakalim, but not that of dictamine, to the right in rat aortic rings precontracted with NA. Dictamine (500 mumol/l) did not affect tonic contraction of NA which are reduced by H-7 (1 mumol/l) in Ca(2+)-depleted medium. In conclusion, fraxinellone is a selective blocker of voltage-dependent Ca2+ channel, while dictamine relaxed the rat aorta by suppressing the Ca2+ influx through both voltage-dependent and receptor-operated Ca2+ channels.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1992

[The role of p53 gene in the switch of U937 leukemic cells from growth into differentiation].

The expression of p53 gene has been found to be regulated during the induction of differentiation of U937 leukemic cells into mature macrophages by recombinant human granulocyte- macrophage colony stimulating factors (rhGM-CSF) We showed here that the increased expression of p53 seemed to be necessary for the differentiation of U937 cells induced by rh-GM-CSF. The inhibition of p53 expression by a p53 antisense oligodeoxynucleotide lead to the significant decrease of formation of mature macrophages from U 937 cells in the presence of rhGM-CSF. By contrast, the p53 sense oligodeoxynucleotide had no any effect. Furthermore, we have analysed the growth of U937 cells in the presence or absence of rhGM-CSF. The results showed that rhGM-CSF dramatically inhibited the growth of U 937 cells in the cultures. At the same time, the antisense inhibition experiment demonstrated that the inhibition of p53 expression partially diminished the growth-inhibitory effect of rhGM-CSF on U 937 cells. These results suggested that the p53 was required for the initiation of rhGM-CSF-induced differentiation of U 937 cells on one hand, and the inhibition of cell growth on the other hand. Thus we deduce that the increased expression of p53 induced by rhGM-CSF may be a coupling event of switch of U 937 cells from growth into differentiation.

Cell Differentiation↗
PubMed1992

[Mouse embryos co-cultured with various generations of human ampullary cells].

The pregnancy rates for the gamete intra-fallopian transfer (GIFT) and tubal embryo transfer (TET) methods have been shown to be high. The oviductal environment appears to be suitable for fertilization and subsequent cleavage. Many authors have reported that when co-cultured with human ampullary cells, the embryos can develop in vitro as well as in vivo. Thus, significantly more embryos reach the early blastocyst stage, and more successful implantation may be obtained. However, the characteristics of the ampullary cells may change after a series of sub-cultures. In this study, we compared the first and the seventh sub-culture ampullary cell co-cultured systems with a control group. There were significantly more embryos cleaved to blastocysts in these two co-cultured systems than in the control group, but no significant difference between these two co-cultured systems. Detoxification of the medium by co-cultured cells may play an important role in improving embryo quality.

Animals↗
PubMed1992

Ovum donation program at Chang Gung Memorial Hospital, Taipei.

The ovum donation program at Chang Gung Memorial Hospital currently confronts the difficulty of limited oocyte resources. The oocytes might be donated from the surplus oocytes of IVF patients. However, after the successful introduction of embryo cryopreservation, patients preferred to have their surplus embryos cryop-reserved and thus, few surplus oocyts were available for donation from IVF program. In addition, official policies discourage use of oocytes donated by consanguineous relatives of either one of the recipient couple or for financial rewards. Among the first three oocytes recipients, with ovarian failure, one chemical pregnancy resulted. Oral premarin and transvaginal and intramuscular progesterone were administered as hormone replacement. The fourth recipient, who had had bilateral oophorectomy, received transdermal estradiol patch (Estraderm) and transvaginal progesterone (Utrogestan) as hormone replacement. The Estraderm/Utrogestan protocol became standard in later cases since the first ongoing pregnancy was achieved in patient 4. We feel this protocol satisfies the required ample levels of hormone replacement for ovum donation.

Adult↗
PubMed1992

[IL-2 potentiates the IL-3 production by ConA activated mouse splenic T cells].

In addition to the regulation of T cell growth, IL-2 exerts effects on the induction of certain lymphokines. We show here that IL-2 synergizes with 5 micrograms/ml of ConA to promote the production of IL-3 in mouse splenic T cell cultures. IL-3 was measured as CFU-GEMM-inducing activity on mouse bone marrow progenitor cells in the supernatant of the stimulated mouse splenic T cells (TCM). The resting T cells produced no CFU-GEMM-inducing activity, but could be induced to produce low level of CFU-GEMM-inducing activity in the presence of ConA. In vitro exposure to IL-2 markedly increased CFU-GEMM-inducing activity production (nearly up to 8-fold) by the ConA-activated T cells. Optimal stimulation was observed when 80 u/ml IL-2 was used for 48 h incubation. Anti-mouse IL-3 monoclonal antibody inhibited the CFU-GEMM inducing activity of TCM. Moreover, the TCM stimulated the proliferation of IL-3 dependent cell line FDC-P1. We also show that IL-2 and ConA-treated T cells expressed high level of IL-3 mRNA through dot blot analysis. These results confirmed the nature of CFU-GEMM-inducing activity of TCM as IL-3. The capacity of IL-2 to promote the production of IL-3 may represent an important mechanism by which it mediate the communication between the immune and hematopoietic systems.

Animals↗
PubMed1991

Determination of trace iodine in food and biological samples by cathodic stripping voltammetry.

This paper describes a sensitive and selective method for the determination of iodine in food and biological samples. The method involves treatment of samples by combustion in an oxygen flask and determination of iodide by cathodic stripping voltammetry of the solid phase formed with the quaternary ammonium salt Zephiramine as the ionic associating agent; Br- is used as the complexing agent in the preconcentration process. We have studied the effect of concentration of Zephiramine, Br-, I-, and some other elements presented, deposition potential, preelectrolysis time, and scan rate, on the stripping curve shape and maximum stripping current. Determinations of trace iodine in table salt, laver, and eggs were demonstrated as practical examples.

Eggs↗
PubMed1991

A clinical pregnancy after a simple method of zona cutting, cryopreservation, and zygote intrafallopian transfer.

A 30-year-old nulliparous woman, who was infertile for greater than 3 years, conceived after the procedures of a simple method of zona cutting, cryopreservation, and ZIFT. This case illustrates: (1) acid medium, chymotrypsin, or sucrose are not needed for the procedure of zona cutting; (2) the zygotes resulting from zona cutting survive through freezing and thawing; and (3) oocyte retrieval can be done concomitant with conservative surgery for endometriosis.

Adult↗
PubMed1991

Influenza virus RNA in the lung and lymphoid tissue of immunologically intact and CD4-depleted mice.

The distribution and clearance of viral RNA (vRNA) and mRNA has been analysed for the acute and recovery stages of the pneumonia induced by intranasal infection of C57BL/6J mice with H3N2 influenza A viruses. Amplification of viral genomic material by the polymerase chain reaction showed that the influenza haemagglutinin (HA) gene was eliminated from the lungs of immunologically intact mice by day 14 post-infection, whereas in vitro depletion of the CD4+ T cells delayed clearance by at most 4 days. Viral RNA encoding the HA gene was first demonstrated in the regional mediastinal lymph nodes at 48 h, and continued to be present until day 6 or day 10 after infection of the intact and CD4-depleted mice, respectively. Evidence for the presence of vRNA in the thymus, but not in the mesenteric lymph nodes or the spleen, was found in some situations. Otherwise, the distribution and clearance of vRNA was as would be predicted from earlier studies using virus isolation procedures to monitor localization patterns, and shows a lack of long-term persistence of the influenza virus genome.

Acute Disease↗
PubMed1991

[A random sample study of therapeutic effect of beta-receptor blocking agents in patients with subarachnoid hemorrhage].

The Study on the treatment of 50 cases of subarachnoid hemorrhage (by applying beta-receptor blocking drug propranolol) and the control group of 55 cases revealed that the mortalities of the therapeutic group and the control group were respectively 4% and 9.2% (P less than 0.05) the incidences of the cerebral vasospasm were 2% and 10.6% (P less than 0.01) and those of the abnormal electrocardiograms were 6% and 21.8% (P less than 0.01). The differences between the two group were significant. The function of propranolol may be associated with the sudden increase of catecholamine after subarachnoid haemorrhage and there for the drug has the function of protection of the cardiac muscle and prevention of the cerebral vasospasm.

Adolescent↗
PubMed1991

[Synthesis of dihydroindoline compounds and their anticholinesterase activity].

A series of dihydroindoline compounds were synthesized. The N-alkylation and O-acylation were controlled selectively by the presence or absence of phase transfer catalyst. The structure of compounds synthesized were ascertained by elemental analyses, 1HNMR, MS, and IR. The anticholinesterase activity was determined by modified Hestrin method and their pCI50 were calculated by Hill's pharmacodynamic formula. The structure-activity relationship was briefly discussed. (1) 5-carbamoyl group is the important factor for the anticholinesterase activity. If cyclic phosphoryl or sulfonyl group is used instead of the carbamoyl group, the inhibiting activity drops sharply. (2) Compounds in which C-3 of the indoline nucleus is quaternary are more potent than those in which C-3 is tertiary or secondary. So the methyl group at C-3 plays an important role in combining the inhibitor with the active center of cholinesterase by the hydrophobic bond. (3) When the indolines are changed into 2-indolinones the inhibiting activity drop steeply.

Cholinesterase Inhibitors↗
PubMed1991

31P magnetic resonance spectroscopy (MRS) of experimental orbital myositis.

We described a model of orbital myositis that was induced by 12-0-tetradecanoyl-phorbol-13-acetate (TPA) injection into the superior rectus muscle of New Zealand white rabbits. In this study, in vivo 31P magnetic resonance spectroscopy (MRS) was performed with a 4.7 Tesla Oxford (Oxford Instruments, Oxford, England) magnet to monitor the evolution of muscle inflammation in control animals and the response of this model to external beam radiation. 31P MRS showed a dramatic increase in high-energy phosphorus and phospholipid metabolites 48 hr after TPA injection. These spectra were similar to those from implanted allogenic fibroblasts. Within 18-48 hr after a single dose (400 cGy) or sequential doses (3 days at 400 cGy) of orbital irradiation, reduced extraocular muscle swelling and a significant decrease of all 31P metabolites occurred. A decrease (63 +/- 6%) in the signal-to-noise (S/N) ratio of the control inflamed muscle 31P MR spectra increased by 28 days after inflammation. Two days after single-dose radiation, 31P MR metabolites were significantly lower (58 +/- 5%, P less than 0.012) than control spectra. These postradiation spectra mirror the 28-day control spectra and are consistent with previous histologic data that show decreased fibroblastic activity. Change in 31P MRS was a sensitive indicator of treatment response latency.

Animals↗
PubMed1990

Coding properties of the S and the M genome segments of Sapporo rat virus: comparison to other causative agents of hemorrhagic fever with renal syndrome.

Three serologically distinct groups of hantaviruses have been associated with severe, moderate, and mild forms of hemorrhagic fever with renal syndrome (HFRS). To gain a better understanding of the genetic variation among these viruses, we cloned and sequenced the M and the S genome segments of Sapporo rat virus, an etiologic agent of moderate HFRS, and compared the predicted gene products to those of Hantaan virus, and the Hällnäs strain of Puumala virus, which are etiologic agents of severe and mild HFRS, respectively. The SR-11 S segment consisted of 1769 nucleotides and had an open reading frame (ORF) in the virus-complementary sense RNA with a coding capacity of 429 amino acids. Deduced amino acids from the SR-11 S segment ORF displayed 83% homology with those of Hantaan nucleocapsid (N) protein. Comparison of the S segment ORFs of all three viruses revealed 58% homology. No evidence for additional nonstructural protein(s) encoded by the SR-11 S segment was obtained. The SR-11 M segment consisted of 3651 nucleotides and had an ORF in the virus-complementary sense RNA with a coding capacity of 1134 amino acids. Amino acid sequences predicted from the SR-11 M segment ORF were 75% homologous with those encoding Hantaan G1 and G2 envelope glycoproteins. Comparison of the deduced amino acid sequences of the M segment ORFs of SR-11, Hantaan, and Hällnäs viruses revealed a 43% homology for amino acids constituting the G1 proteins and a 55% homology for amino acids constituting the G2 proteins of the three viruses. The envelope proteins of SR-11 virus were localized within the M segment ORF by amino-terminal sequence analysis of purified G1 and G2. G1 initiated at amino acid 17 and G2 at amino acid 647 within the ORF. Five potential asparagine-linked glycosylation sites were identified in the SR-11 G1 coding sequences, four of which were conserved between Hantaan and SR-11 viruses and three of which were conserved among all three viruses. One potential glycosylation site was identified in the SR-11 G2 coding sequences and was conserved among Hantaan, SR-11 and Hällnäs viruses. Cysteine residues were highly conserved within the M segment ORFs of all three viruses, suggesting a similar structure and function of the G1 and G2 proteins.

Amino Acid Sequence↗
PubMed1990

Cerebral cysticercosis.

We studied 143 cases of cerebral cysticercosis over a 30-year period. In 46 there was hydrocephalus due to cysts obstructing the cerebrospinal fluid pathways, with signs of hydrocephalus and cerebellar dysfunction. In 97 there were cysts in the cerebral parenchyma, causing symptoms of intracranial hypertension alone in 22 cases, with additional neurological deficits in the remainder. Before 1980 diagnosis was made by pneumoencephalography and ventriculography, but since then it has mostly been done by computed tomography. In 28 cases scanned, typical abnormalities were present in 25. Complement fixation tests were positive in serum in 74% of cases and in cerebrospinal fluid in 73%, and the enzyme-linked immunosorbent assay test was positive in serum in 90% and in cerebrospinal fluid in 92%. Treatment of cases with hydrocephalus was by removal of the cysts at craniotomy, with placement of a shunt where necessary. Intracranial hypertension caused by parenchymal cysts was treated with steroids and osmotic agents, if possible. In resistant cases subtemporal decompression was needed, unilateral in 55 cases and bilateral in eight. Mortality in the acute stage was 11%, with a further 20% at follow up.

Brain Diseases↗
PubMed1990

[Comprehensive study of percutaneous transhepatic aspiration bile culture and cholangiography].

In this study, the results of transhepatically aspirated bile culture, and cholangiography done in 220 cases with biliary tract diseases were presented. Aerobes and anaerobes were found in 76.4% and 64.7% of all samples respectively. Patients with partial common bile duct obstruction from stricture and choledocholithiasis had markedly higher positive cultures than that with simple gallbladder stones and complete common duct obstruction secondary to carcinomas of the pancreas or ampulla. Bile culture from patients with symptomatic cholangitis was much more often positive than those with asymptomatic cholangitis. It was also found that patients with positive bile cultures were more prone to after-PTC acute cholangitis. This study suggested that bile organisms are mainly from the gut, bile organisms and bile duct obstruction are two major causes of acute cholangitis, abrupt elevation of bile pressure during PTC procedure was also a causing factor of acute cholangitis. The authors advocate the comprehensive and prophylactic use of antibiotics both effective to aerobes and anaerobes in the treatment of biliary tract infection.

Adolescent↗