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Biomedical subjects

M Liu

Publications and source records attributed to M Liu.

At least 613 records · Page 34Linked to original sources
PubMed1991

Monoclonal gammapathies in long-term surviving rhesus monkeys after lethal irradiation and bone marrow transplantation.

Late effects of total body irradiation and subsequent autologous bone marrow transplantation on the development of age-related monoclonal gammapathies (MG) were studied in 14 long-term surviving Rhesus monkeys. Together with 27 untreated control monkeys, they have been followed up for more than 20 years. In contrast with the control group, the experimental monkeys developed MG with aging in higher frequencies, earlier and mainly of the benign MG category. One experimental monkey developed a multiple myeloma, the first observed in the nonhuman primates so far. These results indicate an accelerated senescence of the immune system in the experimental monkeys as a late consequence of tissue or cell damage during irradiation.

Animals↗
PubMed1991

Radical-promoting "free" iron level in the serum of rats treated with ferric nitrilotriacetate: comparison with other iron chelate complexes.

Iron plays a critical role in the production of activated oxygen species and the activity of chelated iron in the biological system depends on the chemical forms of the chelators. In the present study, we used ferric nitrolotriacetate (Fe-NTA, molar ratio of iron to chelators = 1:3), ferric ethylenediaminetetraacetate (Fe-EDTA, 1:3 complex) and ferric Desferal (Fe-Des, 1:1.1 complex) to see their "free" iron content in aqueous solutions in vitro and in the serum obtained after a single intraperitoneal injection of the chelates to rats (7.5 mg of iron/kg). "Free" iron was measured by the bleomycin-assay system. When Fe-NTA was dissolved in water, "free" iron increased linearly with total iron concentration up to 10 microM, whereas Fe-EDTA and Fe-Des showed no "free" iron with corresponding iron concentrations. When these three ferric chelates were dissolved in normal rat serum, "free" iron in Fe-NTA increased abruptly between 40 microM and 60 microM iron concentrations, then increased slowly up to 100 microM. Fe-Des did not show any "free" iron at comparable iron concentrations. Fe-EDTA had an intermediate "free" iron level in the serum. Among the ferric chelate complexes, Fe-NTA showed a much faster increase of and a higher content of "free" iron in the serum than the other two complexes after a single injection of the chelates into rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

[Normal full-term pregnancy after allogeneic bone marrow transplantation for severe aplastic anemia: a case report].

A 27 year-old woman had a normal full-term delivery 4 years after bone narrow transplantation for severe aplastic anemia. She had received combination regimens of systemic high-dose cyclophosphamide and one fraction of total body irradiation for 300cGy as pre-BMT conditioning regimens. This case illustrates that after regimens incorporating total body irradiation and high-dose cyclophosphamide, recovery of ovarian function and normal pregnancy are still possible.

Adult↗
PubMed1991

[The analgesic effect of red nucleus and strengthening effect thereof to the acupuncture analgesia].

The modulation of red nucleus (RN) to pain sense was researched with the latent period of radiant-heat tail flick of rats as standard of the pain threshold. The pain threshold of tail flick reflex was raised significantly by bilateral injection of glutamic acid into RN. Simultaneous injecting glutamic acid into RN and lidocaine into nucleus raphe magnus (NRM) could attenuate the raising effect of pain threshold of RN. This showed that the activated RN has analgesic effect and the NRM plays an important role in the descending inhibitory pathway of RN. The discharges of neurons in caudal part of nucleus spinalis tract nervi trigemini (cNST) evoked by stimulating nerve alveolaris inferior (nAI) with strong pulse were recorded with microelectrode. The nAI-evoked discharges might be inhibited by stimulating contralateral or ipsilateral RN. The RN inhibitory time course on nAI-evoked discharges were shortened after injecting lidocaine into NRM. This demonstrated that the inhibitory effect of RN on neurons in cNST is mediated by NRM. The electrical stimulation of acupoint "Jiache" could inhibit the pain-evoked discharges of neurons in cNST. The inhibitory time course of electrical acupuncture were prolonged by stimulating RN. This result revealed that the activated RN can strengthen the analgesic effect of acupuncture.

Acupuncture Analgesia↗
PubMed1991

[Investigation on high risk factors of neonatal necrotizing enterocolitis].

In order to evaluate the factors in high-risk neonatal necrotizing enterocolitis (NEC) and predict the prognosis of NEC, a retrospective analysis of 32 factors was made in 42 neonates with NEC. The cases were divided into a low-risk (survival) group and a high-risk (death) group. Of 32 factors compared between these two group, eight were found to be of significance in evaluating the severity of NEC, and six of them were used in the development of a NEC scores (1) number of days before beginning of artificial feeding; (2) neonatal asphyxia or distress; (3) immature form in WBC differential; (4) CO2 combining power; (5) abdominal tenderness; (6) presence of portal vein air (PVA). All laboratory values and physical and radiographic signs were collected during initial presentation of NEC. Neonates with a score of 3 or more are at an increased risk of developing severe NEC with a 83% mortality.

China↗
PubMed1991

[Efficacy evaluation of measles vaccine in fields].

The result of determining the effectiveness of measles vaccine is reported. It included 196 samples of measles vaccine from 1986 to 1989 in Xiangfang City. There were 14 samples found unqualified. Thus we took the relevant measures and the result was rather good. The investigation confirmed that the cold-chain equipment now available had played a guarantee role for the quality of vaccines. In addition, we analysed the cause of the measles vaccine with low titre. The influences of different districts and seasons on the stability of vaccine had been studied. Some measles vaccine were of low titre but rather high level in HIAb. This problem was investigated and discussed theoretically.

Antibodies, Viral↗
PubMed1991

[Dynamic variation of saikosaponin contents].

In this paper both the cultivated and wild Bupleurum chinense and B. scorzonerifolium from northeast China of different growing periods and ages were analyzed for the contents of saikosaponins a and d by HPLC and total saikosaponins by spectrophotometry. The results indicated that the saikosaponin content of B. chinense was higher than that of B. scorzonerifolium, and that the saikosaponin contents of the cultivated species were higher than or almost equal to those of the wild ones. It was also found that both the cultivated and wild B. chinense and B. scorzonerifolium featured the highest contents of saikosaponins in the nutrition-growing period.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1991

[Transglottic carcinoma: a histopathological study of 64 cases].

Sixty-four cases of the transglottic carcinoma treated with surgical operations at our hospital were reviewed. The anatomical sites and the serial sections of the tumour specimens were observed. It indicated that 42 cases were proved to be supraglottic carcinomas; 7 glottic; 5 subglottic. Ten cases had no definite primary sites. There was no T1 lesion and only one pT2 lesion. 98.4% of the specimens showed pT3-pT4. 75% specimens lesions greater than or equal to 2 cm. Thus we suggest that the so called transglottic carcinoma should be regarded as an advanced lesion of the laryngeal cancers. The advanced cancers can spread into the paraglottic space and invade the laryngeal frame-works as a special pathological features. The paper also discussed the primary site of the transglottic lesion. We think that it is reasonable to classify the laryngeal cancers into supraglottic, glottic and subglottic categories. The idea to classify tumours that originate in the ventricle into an independent type, i.e. transglottic carcinoma, will wait for further discussions.

Adult↗
PubMed1991

[The amount of IgG synthesized within the central nervous system in patients with multiple sclerosis].

IgG-Alb ratio, IgG index and IgG synthesis rate were determined in 40 patients with multiple sclerosis (MS group), 20 patients with other neurologic diseases (OND group) and 22 normal persons (normal group) by using Beckman Immunochemistry System II. The results showed the average values and abnormal frequencies of the three parameters in MS group were significantly higher than those in the normal group and OND group (P less than 0.01), indicating the synthesis of IgG within the central nervous system (CNS) in MS. These parameters were increased in most of the MS patients. Therefore, they could be used in the diagnosis of MS. It was also found that the amount of IgG synthesized within CNS was decreased in patients treated with corticosteroids.

Adolescent↗
PubMed1991

[A study on components and compound prescription of huangqin decoction].

The results obtained from the pharmacological experiments have preliminarily demonstrated that the compound prescription is better than its individual component drug in the range and potency of pharmacological activities. In the prescription Radix Scutellariae plays a principal role in pharmacological effects. Radix Scutellariae and Radix Paeoniae Alba can potentiate each other. Radix Glycyrrhizae and Fructus Jujubae in the compound prescription also exhibit biological activities to some extent. The relieving effect of the prescription for spasm and pain may result from the synergistic interaction between Radix Paeoniae Alba and Radix Glycyrrhiza, and the heat clearing and diarrhea stopping action is due to the biological activity of Radix Scutellariae.

Animals↗
PubMed1990

Failure of (SJL/J x PL/J)F1 hybrid mice to develop immunologic tolerance to V beta 17a+ T cells results in F1 anti-SJL mixed lymphocyte reaction.

It has been reported previously that spleen cells from (SJL x PL) F1 hybrid mice are not tolerant to SJL parental cells as assessed by a one-way MLR. The possibility that the F1 anti-SJL reaction was due to the effect of lymphokines produced by the irradiated SJL T cells in response to I-Eu expressed on the F1 hybrid cells was eliminated since inclusion of anti-I-E mAb was without effect. Cell separations showed the responder cells to be plastic and nylon wool nonadherent Ia- T cells. Separation of the SJL spleen cells showed that the stimulator cells were nonadherent, passed through a nylon wool column, and were Ia-. the F1-anti-SJL MLR was blocked 70 to 90% by inclusion of mAb KJ23a in the culture medium that indicated that the stimulatory cell population was V beta 17a+ T cells. This was confirmed by the use of V beta 17a+ and V beta 17a-T cell clones as stimulators. To determine whether failure to develop tolerance to this T cell subset in F1 hybrid mice might be responsible for the F1-anti-parent MLR, (SJL x PL)F1 mice were treated at birth and 48 h thereafter with anti-I-E mAb for 7 wk. Spleen cells from antibody-treated F1 mice were nonreactive with irradiated SJL parental cells in contrast to spleen cells from control mice which indicated that V beta 17a+ T cells were eliminated by negative selection before the development of tolerance.

Animals↗
PubMed1990

Comparison of the effects of intra-arterial and locally applied vasoactive agents on pulpal blood flow in dog canine teeth determined by laser Doppler velocimetry.

The vasoactive agents norepinephrine, 5-hydroxytryptamine, isoproterenol and bradykinin, at concentrations which changed local arterial pressure without changing systemic arterial pressure significantly, were injected intra-arterially (i.a.) into the maxillary artery or applied directly in a deep dentinal cavity on the buccal surface of canine teeth. The probe of a laser Doppler velocimeter was placed in the cavity to monitor pulpal blood flow. Bolus i.a. injections of the vasoconstrictors norepinephrine and 5-hydroxytryptamine produced a statistically significant (p less than 0.05) reduction in pulpal blood flow, 21.1 +/- 3.7 and 30.7 +/- 15.2%, and the local arterial pressure from the lateral nasal artery increased with norepinephrine but decreased with 5-hydroxytryptamine. The i.a. injections of the vasodilators isoproterenol and bradykinin were found to decrease both local arterial pressure and pulpal blood flow, 17.7 +/- 6.0 and 22.7 +/- 4.2%, respectively (p less than 0.05). However, local application of isoproterenol and bradykinin caused a biphasic response: an increase in pulpal blood flow, 8.6 +/- 1.6 and 9.4 +/- 1.1% (p less than 0.05), followed by a decrease, 19.1 +/- 11.9 and 5.3 +/- 2.1% (p greater than 0.005). Local application of norepinephrine and 5-hydroxytryptamine caused a decrease in pulpal blood flow, 23.7 +/- 5.2% (p less than 0.05) and 9.3 +/- 5.2% (p less than 0.05), respectively. These findings were in accordance with those from other reliable methods, such as injections of radioisotope-labelled 15 microns microspheres and the 133Xe washout technique, making laser Doppler flowmetry a reliable alternative. In addition, the biphasic response to the locally applied vasodilators and the reduction of pulpal blood flow after i.a. injection of vasodilators suggest that regulation of pulpal blood flow is determined by the combined effects of the low compliance environment and the stealing of perfusion to the pulp by the neighbouring tissues.

Administration, Topical↗
PubMed1990

Comparison of pulpal blood flow in dog canine teeth determined by the laser Doppler and the 133xenon washout methods.

Pulpal blood flow measurements by laser Doppler flowmetry were compared with those made simultaneously and on the same teeth by the 133Xe washout method. Pulpal method flow in the resting state was 82.4 ml/min per 100 g as calculated from the fast component of the 133Xe washout, whereas laser Doppler flowmetry recorded 263 mV. The close intra-arterial (i.a.) injection of the vasoconstrictor norepinephrine (10(-2)-10(-1) micrograms/kg) caused a reduction of pulpal blood flow by 20.2% with the 133Xe washout and by 9.7% with the laser Doppler flowmetry in 6 observations in 4 dogs. The laser Doppler flowmetry measurements of these norepinephrine-induced changes correlated significantly with changes measured by the 133Xe washout method as analysed by linear regression (p = 0.004).

Animals↗
PubMed1990

[Synthesis of zinc chlorophyllin a and its preliminary clinical application].

A method for synthesis of zinc chlorophyllin a (I), a promising drug for clinical application, is presented. Taking silkworm faeces as a raw material. Chlorophyll was extracted with ethyl alcohol. After concentration the solid formed was dissolved in petroleum ether and the solution was subjected to column chromatography to separate pheophytin a and chlorophyll a. The products were dissolved in ethyl ether and the Mg in the products was stripped off with concentrated hydrochloric acid. The excess hydrochloric acid in the solution was neutralized with ammonia solution and the mixture was hydrolyzed with diluted hydrochloric acid to obtain pheophorbide a, then (I) was synthesized with pheophorbide a and zinc salt. The characteristics of (I) and pheophorbide a were checked by IR, UV and elemental analyses. All results of pheophorbide a coincided with those values reported in literature. The acute toxicity of (I) was tested in mice and the LD50 of (I) was 324 +/- 40 mg/kg. (I) has been applied in several hospitals for several months. It has been found that (I) has outstanding effects on burns and oral sepsis and that it increases the growth of granulation tissue and epithelium remarkably.

Animals↗