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Biomedical subjects

H Liang

Publications and source records attributed to H Liang.

At least 217 records · Page 12Linked to original sources
PubMed1993

Effect of the antioxidant TK 12627 (Irganox) on monodeiodination and on the levels of messenger ribonucleic acid of 5'-deiodinase type I and spot 14.

Until now, most potent inhibitors of monodeiodination are iodinated, propylthiouracil being an exception. We report here studies on a new non-iodinated substance, triethylene glycol bis-3-(3-tert-butyl-4-hydroxy-5-methyl-phenyl) propionate (TK 12627 or Irganox), which is used as a very efficient antioxidant in the chemistry of plastics. The studies were performed with 23 hypothyroid rats that received Irganox in their daily food (8 mg.day-1 x (100 g body wt)-1) for 3 weeks. Thyroxine (T4) metabolism was studied by implanting minipumps delivering 2.3 nmol T4.day-1 x (100 g body wt)-1 for 1 week. On day 1 before sacrifice, another minipump containing [125I]-3,5,3'-triiodothyronine (T3, 2.6 microCi/day) and [131I]-3,3',5'-triiodothyronine (rT3, 2.1 microCi/day) was implanted. The results showed that with Irganox treatment serum T4 concentrations were higher (p < 0.05). Serum T3 concentrations markedly decreased (1.07 +/- 0.07 vs 0.65 +/- 0.04 nmol/l), accompanied by a decrease of free T3 concentrations (p < 0.001). Serum rT3 concentrations increased by 50% (p < 0.001). Serum thyrotropin levels were mostly unmeasurable. The plasma clearance rate decreased slightly for T4 (19%, p < 0.05) and remarkably for rT3 (46.7%, p < 0.001). The conversion rate of T4 to rT3 did not change. Deiodinase type I (5'D-I) activity decreased in both liver and kidney tissues by 54% and 52%, respectively, and correlated with T3 (r2 = 0.79 and 0.65, respectively). Brain deiodinase type III (5D-III) was unchanged and type II (5'D-II) was unmeasurable.(ABSTRACT TRUNCATED AT 250 WORDS)

Actins↗
PubMed1993

[A discussion of jaws relation in complete denture restoration]

We studied jaws relation of 8 edentulous patients after complete denture restoration by using Digital Sirognathograph (D-SGG).The results indicated that the maximum intercuspation occlusion (i.e.CO or MCP) is not commonly coincident with the CRO,and the discrepancy is statistically significant.The CO is anterior to the CRO by 0.72+/-0.39mm,and it may vary significantly in different closures of the same patient. This implies that the termination of the occlusion with neuromusculature is not strictly precise and constant,but alters in a corresponding range.So,it seems reasonable to develop a "freedom of centric" in the range of 0.72+/-0.39mm anterior to the CRO.The physiological functional occlusion,therefore,is restricted to neither of the CO nor the CRO, but is guided between the two.

Journal Article↗
PubMed1993

[The effect on longevity of blood pressure and body mass index in a community of Kyoto].

To assess the combined influence of blood pressure and body mass index (BMI) on death from all-cause and circulatory diseases, a retrospective cohort study was performed in a community of Kyoto from 1978 to 1991. Between 1978 and 1982, 1,629 people (650 men and 979 women) aged 40-69 years, representing 76.6% of this age group in the community, were screened for entry into this study. A total of 134 deaths were observed and death by circulatory diseases was 36.6% of the all-cause deaths. The survival rate, calculated by the Kaplan-Meier method, was higher among normotensives [systolic blood pressure (SBP) < 140 mmHg and diastolic blood pressure (DBP) < 90] compared to borderline hypertensives (SBP = 140-159 and/or DBP = 90-94) and hypertensives (SBP > = 160 or DBP > = 95, or using antihypertensive medication) for subjects aged 50-69 years both males and females. The hazard ratio of all-cause and circulatory disease mortality for sex, age, blood pressure and BMI as covariables was estimated from the Cox proportional hazard model. The hazard ratio (95% confidence interval) was greater for circulatory disease mortality [2.76 (1.37-5.75) for borderline hypertensive and 2.53 (1.21-5.26) for hypertensive] than for all-cause mortality [1.86 (1.22-2.84) for borderline hypertensive and 2.03 (1.32-3.10) for hypertensive]. These results indicate that hypertension increases risk of circulatory disease mortality and decreases survival rate. While the effect of obesity was not as strong for circulatory disease mortality as blood pressure, an increase in hazard ratio with increasing BMI was suggested in this study.

Adult↗
PubMed1993

[Association between participation in health check and visiting medical facilities in residents in a rural town].

Participants in a community secondary prevention action sponsored by the local government were compared with non-participants with respect to utilization of medical facilities for medical examinations. The study sample consisted of 1,013 males and 1,042 females aged 40 years or over, in a rural town in Kyoto prefecture, who were members of the National Health Insurance. Data from National Health Insurance records, such as date of consultation and type of medical examinations, were analyzed. The secondary prevention action sponsored by the town consisted of a multiphasic health check for circulatory or other chronic diseases, and screenings for tuberculosis and cancers of the stomach, lung, breast and cervix. Medical examinations included urine test, blood cell count, electrocardiography, laboratory tests for serum transaminases, serum glucose, and fecal occult blood, X-ray or endoscopy of the stomach, chest X-ray, mammography, and cervical cytology. Results of the study showed that those who attended the town sponsored secondary prevention action were more likely to utilize local medical facilities, and those who did not participate were likely to visit facilities outside the town. Medical facilities, both local and outside the town, had a larger proportion of examinations corresponding to health examinations or stomach cancer screening than the town office, however, the town office had a larger proportion of lung or cervical cancer screening. The health examination and stomach cancer screening in the town office, and in the medical facilities appeared to be redundant while lung and cervical cancer screening were complemented tests at medical facilities. When these examinations are targeted as modifying factors in the natural history of diseases, consideration should be given to both the records of secondary prevention actions as well as medical records of other medical facilities that may be utilized.

Adult↗
PubMed1993

[Studies on the triterpenoids from roots of Glycyrrhiza squamulosa Franch].

A new triterpenoid, squasapogenol (S-11), was isolated from the hydrolytic products of dilute ethanol (10%) extract of the roots of Glycyrrhiza squamulosa Franch, along with four known triterpenoids. The structure of S-11 was elucidated as olean-11,13(18)-diene-3 beta, 22 beta-diol on the basis of chemical and spectroscopic data. The four known compounds were identified as betulinic acid(S-8), methyl ester of macedonic acid(S-9), soyasapogenol B (S-10) and olean-13(18)-ene-22 alpha-Cl-3 beta, 24-diol(S-12).

Drugs, Chinese Herbal↗
PubMed1992

Optical trapping in animal and fungal cells using a tunable, near-infrared titanium-sapphire laser.

We have compared two different laser-induced optical light traps for their utility in moving organelles within living animal cells and walled fungal cells. The first trap employed a continuous wave neodymium-yttrium aluminum garnet (Nd-YAG) laser at a wavelength of 1.06 micron. A second trap was constructed using a titanium-sapphire laser tunable from 700 to 1000 nm. With the latter trap we were able to achieve much stronger traps with less laser power and without damage to either mitochondria or spindles. Chromosomes and nuclei were easily displaced, nucleoli were separated and moved far away from interphase nuclei, and Woronin bodies were removed from septa. In comparison, these manipulations were not possible with the Nd-YAG laser-induced trap. The optical force trap induced by the tunable titanium-sapphire laser should find wide application in experimental cell biology because the wavelength can be selected for maximization of force production and minimization of energy absorption which leads to unwanted cell damage.

Aluminum Oxide↗
PubMed1992

Comparison of hematopoietic and immune recovery after autologous bone marrow or blood stem cell transplants.

We studied hematopoietic and immune recovery in 40 subjects receiving autologous bone marrow (ABMT) or blood stem cell transplants (ABSCT). Supportive care, transplant-related morbidity, duration of hospitalization and cost were also considered. ABSCT was associated with more rapid recovery of all hematopoietic lineages than was ABMT. However, kinetics of immune recovery were similar between the groups. In the ABSCT group, there was a correlation between numbers of blood progenitor cells infused and the rate of hematopoietic recovery. The accelerated hematopoietic recovery following ABSCT correlated with less morbidity, fewer transfusions, briefer hospitalization and lower cost than ABMT.

Adolescent↗
PubMed1992

[Clinical and experimental study on its regulatory function of yi xin decoction (heart-nourishing decoction) to lipids metabolic disturbance in coronary heart disease].

In this research, 74 patients with coronary heart disease (CHD) were grouped in matched-pair, one group took orally Inositol and Mai Tong as the control group, the other group took orally Yi Xin Decoction as the tested group. Indices, i. e. serum levels of apolipoprotein A-1 (Apo A-1), apolipoprotein B (Apo-B), high density lipoprotein cholesterol (HDL-c), high density lipoprotein subcomponent cholesterol (HDL2-c), B-lipoprotein (B-LP), total cholesterol (Tch), triglyceride (TG) were measured before and after treatment for 28 days; the results showed that the patients with CHD have prominent derangement of lipid metabolism, which is similar to previous reports. Yi Xin Decoction modified according to Syndrome Differentiation, produced the effect of decreasing the serum Apo-B levels and TG. It also increased Apo-A-1, HDL-c and HDL2-c respectively. Moreover the effect of lowering Apo-B and raising HDL-c in the Yi Xin Decoction group was better than that in the control group. There was no side effect at all; all these indicated that Yi Xin Decoction has a remarkable function of regulating the disturbance of lipid metabolism in CHD patients. In order to further investigate the curative effect of Yi Xin Decoction and elucidate its mechanism, the authors have also investigated Yi Xin Decoction on the experimental mice with hyperlipemia. The result Showed that Tch and TG in atromid and Yi Xin Decoction group reduced after medication, P < 0.01. In comparing with control group, the HDL-c and acidic cholesterol in stool Yi Xin Decoction group rose, P < 0.05. The above study has provided reliable basis for the clinical application of Yi Xin Decoction and also a new medicine to regulate disturbance of lipid metabolism for CHD patients.

Animals↗
PubMed1991

Reversible denaturation of the gene V protein of bacteriophage f1.

The guanidine hydrochloride (GuHCl)-induced denaturation of the gene V protein of bacteriophage f1 has been studied, using the chemical reactivity of a cysteine residue that is buried in the folded protein and the circular dichroism (CD) at 211 and 229 nm as measures of the fraction of polypeptide chains in the folded form. It is found that this dimeric protein unfolds in a single cooperative transition from a folded dimer to two unfolded monomers. A folded, monomeric form of the gene V protein was not detected at equilibrium. The kinetics of unfolding of the gene V protein in 3 M GuHCl and the refolding in 2 M GuHCl are also consistent with a transition between a folded dimer and two unfolded monomers. The GuHCl concentration dependence of the rates of folding and unfolding suggests that the transition state for folding is near the folded conformation.

Coliphages↗
PubMed1991

Micromanipulation of mitotic chromosomes in PTK2 cells using laser-induced optical forces ("optical tweezers").

To study the potential use of optical forces to manipulate chromosome movement, we have used a Nd:YAG laser at a wavelength of 1.06 microns focused into a phase contrast microscope. Metaphase and anaphase chromosomes were exposed while being monitored by video microscopy. The results indicated that when optical forces were applied to late-moving metaphase chromosomes on the side closest to the nearest spindle pole, the trapped chromosomes initiated movement to the metaphase plate. The chromosome velocities were two to eight times the normal rate depending on the chromosome size, geometry, and trapping site. At the initiation of anaphase, a pair of chromatids could be held by the optical trap and kept motionless throughout anaphase while the other pairs of chromatids separated and moved to opposite spindle poles. As a result, the trapped chromosome either was incorporated into one of the daughter cells or was lost in the cleavage furrow, or the two chromatids eventually separated and moved to their respective daughter cells. If the trap was removed at the beginning of anaphase B, the chromosome moved back to the poles. Our experiments demonstrate that the laser-induced optical force trap is a potential new technique to study noninvasively the mitotic spindle of living cells.

Analysis of Variance↗
PubMed1990

New type of X-linked progressive muscular dystrophy involving shoulder girdle and back.

A new type of X-linked muscular dystrophy is described in a family in which 7 men had boyhood onset of progressive dystrophy involving muscles of the shoulder and back but not the calves or face. The scapula-back muscles are affected, but the calf muscles are normal. All patients are still able to walk. The oldest patient is now 37 years old. The muscular dystrophy has been specified by electromyography, pathologic tissue microscopic examination, electron microscopic study, and elevated CK. This type of muscular dystrophy has not been reported previously.

Adolescent↗
PubMed1990

[Rapid identification of Mycobacterium tuberculosis and other mycobacteria with Mycobacterium tuberculosis whole chromosomal DNA probe].

The dot-blots containing DNA isolated from nonmycobacterial and mycobacterial microorganisms were hybridized with 32P-labeled M. tuberculosis whole chromosomal DNA at the various temperatures. The probe did not cross-hybridize to DNA of nonmycobacterial microorganisms (E. coli, Plasmid pUC19, Nocardia asteriodes), nor with DNA from all mycobacteria tested except M. bovis BCG under the higher temperature conditions. Microorganisms could also be directly spotted and lysed on nitrocellulose filters and used for hybridization thus making this technique suitable for clinical diagnosis.

DNA Probes↗
PubMed1990

Effects of pulse length and pulse strength on transfection by electroporation.

The relative importance of pulse field strength E and pulse length tau 1/2 (half decay time of an exponential decay pulse) on the stable transfection frequency for HeLa or HUT-78 cells was investigated. Cells were transfected with plasmids containing the promoter and drug resistant genes pRSVgpt or pRSVneo by electroporation. The stable transfection frequency was assayed using the marker rescue technique. The transfection frequency increases with increasing values of E tau 1/2. For a given pulse length, the transfection frequency is proportional to the power of the pulse (E2 tau 1/2). Pulses with half decay times of 2.2 to 4.6 ms appear to be more efficient than 0.275 to 0.31 ms for stable transfection of HeLa cells.

DNA↗
PubMed1989

An estradiol-dependent protein from chicken liver binds single-stranded DNA and RNA.

We have identified two estradiol-dependent single-stranded DNA binding proteins in the nucleus and cytoplasm of chicken hepatocytes that bind the sequence 5'TCACCTTCGCTATG3' in the first exon of the chicken vitellogenin gene. As judged by chromatography on heparin-Sepharose and by proteolytic clipping bandshift assay, the two proteins are different. Furthermore, they only bind to the oligonucleotide corresponding to the upper strand. Depurination and depyrimidination interference experiments with the cytoplasmic protein show that the bases CCTT-G are involved in the protein-DNA interaction. An RNA corresponding to the upper strand of the gene between nucleotide positions -73 and +53 competes for binding to the single-stranded DNA. UV cross-linking experiments performed with bromouridine-substituted single-stranded RNA reveal that an estradiol-dependent hepatocyte cytoplasmic protein with a Mr of 71,000 binds to the mRNA-like single-stranded RNA.

Animals↗
PubMed1989

Study on mechanism of micronucleoli formation by laser microirradiation.

In the male rat kangaroo cell line PTK2, argon laser (514.5 nm) microirradiation of both nucleoli in interphase cells 30, 23, and 12 h before mitosis, and nucleoli in early prophase cells resulted in the formation of micronucleoli, i.e., several small nucleolus-like bodies, in daughter cells. The irradiated cells were stained with methylene blue, which indicated that the nucleolar RNA was destroyed by laser microirradiation. Feulgen staining was applied to the irradiated cells in combination with the measurements of an MPV-II model microphotometer. Irradiated nucleoli were negative for DNA-Feulgen stain, which indicated that nucleolar DNA was destroyed by laser irradiation, so the nucleolar organizer gene was destroyed. After the nucleoli had been irradiated, the cells were continuously incubated at 37 degrees C for 12 and/or 24 h, then fixed and stained with AgNO3. Most of the nucleoli irradiated silver-stained negative that demonstrated that when the nucleoli were irradiated, rDNA was destroyed and transcription stopped. However, some silver grains were found in the nucleoplasm, whereas the nucleoli were silver-stained negative. The results suggest that subsidiary nucleolar organizer loci might exist scattered throughout the genome.

Animals↗
PubMed1989

[The relationship between coronary artery stenosis and myocardial metabolism of oxygen demand in dogs].

In open chest dogs, a micrometer constrictor was used to produce three different coronary artery stenosis (AS) on left circumflex coronary artery, and hemodynamics, blood gas and coronary sinus pH, lactate were then measured. In mild coronary AS, resting coronary artery flow (CBF) did not decrease; but lactate increased. In critical coronary AS, CBF slightly decreased, MVO2 decreased and lactate increased. There was a decrease in CBF, O2 supply/consumption ratio, coronary sinus pH and an increase in oxygen extraction and lactate with severe coronary AS. The percent area stenosis (%AS) was highly correlated with O2 supply (r = -0.92), poorly correlated with MVO2 (r = -0.58) when it was higher than 75%.

Animals↗
PubMed1988

Balanced X;15 translocation 46,X,t(X;15)(q21;q23) associated with primary amenorrhea.

Cytogenetic studies on a woman with primary amenorrhea showed an X;15 translocation, karyotype 46,X,t(X;15)(q21;q23). Fifteen percent of the buccal cells showed a normal-sized sex chromatin body. The normal X chromosome was uniformly inactivated. Many balanced X;15 translocations have been reported; however, breakpoints in our patient differ from those reported previously. This case also supports earlier evidence that ovarian development fails when the breakpoint of the X chromosome is in the region X q13-q25 or q13-q27.

Adult↗