Biomedical subjects

Q Li

Publications and source records attributed to Q Li.

At least 775 records · Page 43Linked to original sources

PubMed1996

[Clinical and experimental study of faeces trogopterus on protection of gastric mucosa].

The cure rate of Faeces Trogopterus in treating duodenal ulcer for six weeks was 70.59% and the total effective rate of which was 91.18%. The Shay model of rats was used. The result revealed that Faeces Trogopterus could protect the gastric mucosa. These results preliminarily indicated the mechanism of this drug was inhibiting gastric secretion and regulating gastric mucosal blood flow so as to enhance mucosal defense.

Adult↗

PubMed1996

[Experimental study on zhuanggu shengbao in preventing hormone-induced osteoporosis of rats].

Twenty four male Sprague-Dawley rats at 3 months of age were divided randomly into 3 groups. Prednisone acetate was given to the group B twice per weeks, Zhuanggu Shengbao (ZGSB) was added to the group C besides prednisone, the group A was control. The histomorphometric parameters of bone slides of proximal tibia were measured and calculated with image pattern analyser after 3 months of medication. Results showed that in comparing with group A, in group B the area and number of trabecula decreased, the intertrabecular space increased due to the bone resorption exceeded the bone formation, and the symptoms of osteoporosis revealed obviously. However, in group C, the bone resorption rate was markedly inhibited, and the formation of new bone accelerated so that the bone mass increased significantly. These results indicated the ZGSB could prevent the osteoporosis induced by prednisone acetate.

Animals↗

PubMed1996

Transformation of Pleurotus sapidus protoplasts by electroporation.

The total DNA of Pleurotus ostreatus was successfully transferred into the protoplasts of monokaryotic mycelia of Pleurotus sapidus by electroporation. The transformants were selected by their clamp connection of dikaryocyte, and the transformation frequency and transformation rate were 8.2 x 10(-5) and 3.6%, respectively. Analyzing the esterase isozyme, it was found that the transformants showed some isozyme bands of P. ostreatus and P. sapidus, and new non-parental bands. This proved that the recombination occurred between the DNAs of P. sapidus and P. ostreatus. The fruit bodies of the transformants showed morphological changes.

Electroporation↗

PubMed1996

Chronic fluoxetine induces a gradual desensitization of 5-HT1A receptors: reductions in hypothalamic and midbrain Gi and G(o) proteins and in neuroendocrine responses to a 5-HT1A agonist.

The time course of fluoxetine-induced desensitization of hypothalamic 5-hydroxytryptamine1A receptors was examined in rats. Daily injections of fluoxetine (10 mg/kg/day) for 0, 3, 7, 14 or 22 days gradually produced a shift to the right in the dose-response curve effects of 8-hydroxy-2-(dipropylamino)tetralin (8-OH-DPAT) on plasma adrenal corticotropic hormone, corticosterone and oxytocin. A partial reduction was observed for the adrenal corticotropic hormone and oxytocin responses to 8-OH-DPAT (50 micrograms/kg s.c.) after 3 days, and a maximum reduction of all hormone responses was observed after 14 days of fluoxetine injections, when the adrenal corticotropic hormone and oxytocin responses to the 50-micrograms/kg dose of 8-OH-DPAT were virtually blocked. To begin to examine the mechanism of 5-hydroxytryptamine1A receptor desensitization, we determined levels of Gi and G(o) proteins in the hypothalamus, midbrain and frontal cortex by using immunoblots. The hypothalamic levels of Gi1 and Gi3 proteins were significantly reduced after 7 and 14 days of fluoxetine injections. The levels of G(o) and Gi2 proteins in the midbrain were significantly decreased after 3 days and remained reduced for the duration of fluoxetine injections. Fluoxetine did not reduce the concentrations of Gi and G(o) proteins in the frontal cortex at any time. The similarity in time course between fluoxetine-induced reductions in hormone responses to 8-OH-DPAT and the reduction in hypothalamic levels of Gi1 and Gi3 proteins suggests that a reduction in hypothalamic levels of Gi3 and/or Gi1 proteins plays a role in the gradual desensitization of 5-hydroxytryptamine1A receptors induced by fluoxetine.

8-Hydroxy-2-(di-n-propylamino)tetralin↗

PubMed1996

Neuroendocrine pharmacology of three serotonin releasers: 1-(1,3-benzodioxol-5-yl)-2-(methylamino)butane (MBDB), 5-methoxy-6-methyl-2-aminoindan (MMAi) and p-methylthioamphetamine (MTA).

Serotonin (5-hydroxytryptamine, 5-HT)-releasing drugs are important experimental tools to examine the role of serotonergic nerve terminals in the secretion of hormones. The drugs 1-(1,3-benzodioxol-5-yl)-2-(methylamino)butane (MBDB), 5-methoxy-6-methyl-2-aminoindan (MMAI) and p-methylthioamphetamine (MTA) have been suggested to be 5-HT releasers. The present study characterized MBDB, MMAI and MTA by using their effects on the secretion of the hormones adrenal corticotrophin (ACTH), corticosterone, prolactin, oxytocin and renin. The time course of the effect of MBDB, MMAI and MTA (5 mg/kg, i.p.) showed that the peak effect on plasma ACTH occurred 10 min after the injection, whereas the prolactin response did not reach a maximum until 30 min after injection. MBDB increased plasma renin concentration within 10 min, whereas the effect of MTA was significant only at 30 min after injection. All three 5-HT releasers decreased HR (within 5 min) and blood pressure (at 15 min after injection). MBDB, MMAI and MTA increased plasma ACTH, corticosterone, prolactin and renin levels in a dose-dependent manner, whereas no changes were observed in plasma vasopressin concentrations. MTA and MMAI, but not MBDB, significantly increased plasma oxytocin concentrations in a dose-dependent manner. Pretreatment of rats with fluoxetine blocked the ACTH response to MBDB and MMAI, but not to MTA. The prolactin response to all three 5-HT releasers was blocked by fluoxetine. The oxytocin response to MTA and MMAI was inhibited by fluoxetine. The renin responses to all three 5-HT releasers were not significantly inhibited by fluoxetine. The results suggest that MBDB, MMAI and MTA can increase the secretion of several hormones, at least in part, through stimulation of serotonergic neurotransmission. However, these three 5-HT releasers seem to have effects on other (and as yet uncharacterized) mechanisms that can stimulate the secretion of some hormones.

3,4-Methylenedioxyamphetamine↗

PubMed1996

Topical cyclosporine inhibits mast cell-mediated conjunctivitis.

PURPOSE: Allergic conjunctivitis is a common condition caused by a mast cell-mediated hypersensitivity reaction to immunoglobulin E-bound allergens. The purpose of this study was to investigate the effect of topical cyclosporine A on the development of mast cell-mediated conjunctivitis in mice. METHODS: Allergic conjunctivitis was induced in C57BL/6 mice by topical applications of compound 48/80, a mast cell degranulating agent. In two separate experiments, mice were treated with topical cyclosporine A (0.05%, 0.2%, or 0.4%), prednisolone acetate 1%, or phosphate-buffered saline. Twenty-four hours after compound 48/80 instillation, the number of neutrophils, eosinophils, lymphocytes, macrophages, and the number of preserved goblet cells and undegranulated mast cells in the conjunctiva were counted by a masked observer. RESULTS: In both experiments, treatment with all three doses of cyclosporine A resulted in a statistically significant reduction in the number of infiltrating neutrophils and eosinophils compared to saline-treated controls. There was no significant difference in the treatment effect of cyclosporine and prednisolone acetate. In addition, there was increased preservation of goblet cells in the cyclosporine A-treated animals. Immunohistochemical staining showed a reduction in infiltrating lymphocytes and a smaller reduction in infiltrating macrophages in animals treated with cyclosporine compared to saline-treated controls. CONCLUSIONS: Topical cyclosporine A was effective in inhibiting the development of mast cell-mediated allergic conjunctivitis in mice. This study suggests that topical cyclosporine A may be effective in treating allergic conjunctivitis in humans.

Administration, Topical↗

PubMed1996

[The influence on prognosis of intraoperative chemotherapy for adenocarcinoma of gastric cardia].

Four hundred and four patients underwent surgical treatment for adenocarcinoma of the gastric cardia in our hospital between January 1980 to June 1990. Of 342 resected cases, 231 cases were treated with surgery alone, their 1-, 3-, and 5-year survival rates were 83.8%, 38.5% and 20.8%, respectively. Since January 1987, postoperative chemotherapy was given in 47 patients, their 1-, 3-, and 5-year survival rates were 89.4%, 46.8%, 29.8%, respectively, while intraoperative chemotherapy in 54 cases, had 1-, 3-, and 5-year survival rates of 87.1%, 63.0% and 38.9%, respectively. The result showed that the 3- and 5-year survival rates were higher in postoperative chemotherapy cases than in cases with operation alone, but there was no statistical significance between the two groups. However, intraoperative chemotherapy group had much higher 3- and 5-year survival rates than operation alone (P < 0.01). Intra-operative chemotherapy is recommended especially in patients beyond stage I with lymph node metastasis.

Adenocarcinoma↗

PubMed1996

The central distribution of adrenomedullin and its effects on blood pressure and heart rate in rats.

The present study was designed to make certain whether there exists adrenomedullin (ADM) in the rat central nervous system and evaluated the hemodynamic actions of intracerebroventricular administration (ICVA) of human ADM[13-52]. By immunohistochemistry (ABC method). We found that there was a discrete localization of ADM-positive immunoreactivity in the rat central system including cerebral cortex, paraventricular tissues, hypothalamus, cerebella cortex, mesencephalon and medulla oblongata. By reverse transcription-polymerase chain reaction (RT-PCR) analysis, rat ADM mRNA was found to be expressed in rat brain. These above results of immunohistochemistry and RT-PCR suggest that ADM exists in the rat brain. We also found that centrally administered ADM[13-52] in a dose of 0.4 to 3.2 nmol/kg provoked marked, prolonged and dose-dependent increases in mean arterial blood pressure (MABP) and heart rate (HR). To clarify the mechanisms of the hemodynamic changes induced by centrally administered ADM [13-52], the effect of centrally administered ADM[13-52] on renal sympathetic nerve activity (RSNA) was studied. The result showed that centrally administered ADM [13-52] (1.6 nmol/kg) provoked a marked increase in RSNA, therefore, the increases in MABP and HR induced by centrally administered ADM [13-52] might be due to the stimulation of central sympathetic mechanism. In addition, we also compared the relationship of activity and structure among the different fragments of ADM. In conclusion, ADM exists in the rat brain, and it may play an important role in the central control of cardiovascular system.

Adrenomedullin↗

PubMed1996

Surgical treatment of coronary artery fistulae associated with other cardiovascular anomalies.

OBJECTIVE: To evaluate retrospectively our surgical experience, techniques and long-term results in 11 patients with coronary artery fistulae associated with other cardiovascular anomalies. METHODS: From January 1980 to April 1995, 11 patients with coronary artery fistulae associated with other cardiovascular anomalies were found among 20,000 open-heart procedures and treated surgically. Besides closure of the fistulae, coronary artery bypass grafting was performed in 5 patients with atherosclerotic coronary artery disease, and aneurysm angioplasty was done in 4 patients with coronary artery aneurysm. Ventricular septal defect and patent ductus arteriosus were closed in one patient and mitral valve replacement was performed in another patient. RESULTS: There were no surgical deaths, but one late death due to acute myocardial infarction occurred 6 months after surgery. The mean follow-up time was 75.7 months and all patients' functional status improved by an average 1.4 judged by the New York Heart Association functional classification. CONCLUSIONS: Coronary artery fistula associated with other cardiovascular anomalies will aggravate symptoms and cause deterioration of heart function. Therefore, evaluation and surgical intervention should be done as soon as possible to restore coronary blood flow and correct concomitant cardiovascular anomalies. The surgical results are excellent with a low operative risk and good long-term results.

Adult↗

PubMed1996

Rat as an animal model carrying human hepatitis B virus in hepatocytes.

OBJECTIVE: To establish an experimental animal model of rat carrying human hepatitis B virus in the hepatocytes using a simple and reproducible method. MATERIALS AND METHODS: Human serum rich in hepatitis B virus was injected into portal veins and caudalis veins of young male Wistar rats. One and two months after the injection, liver biopsies were done. In situ hybridization and immunohistochemical study of liver specimens were carried out. Sera were also examined for HBV DNA by polymerase chain reaction. RESULTS: All of seven rats in this experiment were HBV DNA and HBV surface antigen (HBsAg) positive in their hepatocytes. Most HBV positive hepatocytes were distributed around the central vein and scattered in the liver lobules, and HBV DNA and HBsAg were located in cytoplasm. HBsAg exists mainly as the forms of diffuses and inclusion body. No hepatocytic damage or inflammation was observed. Neither viremia nor antigenemia was detected. CONCLUSIONS: Our studies showed for the first time that natural human HBV can enter Wistar rat liver cells through intravenous injection efficiently and express for a long period. This animal model can be used in the studies of HBV molecular biology, therapeutic regimens and prophylaxis against HBV. A possible mechanism of HBV entering rat hepatocytes is also proposed.

Animals↗

PubMed1996

[The protective effect of nicotinamide on interleukin-1 beta induced damage to rat islets of Langerhans and its mechanism].

OBJECTIVE: To investigate the protective effects of nicotinamide (NA) on newborn rat islets of Langerhans. METHODS: Newborn rat islets were isolated by digestion of collagenase V. The effects of IL-1 beta and/or NA on insulin release and nitric oxide (NO) production and 3H-thymidine incorporation were studied. RESULTS: NA had no effects on both accumulated insulin release and insulin release at an acute glucose challenge, but increased 3H-thymidine incorporation. 25 mmol/L of NA reduced the inhibition of accumulated insulin release and 3H-thymidine incorporation induced by 40/ml of IL-1 beta. However. NA was not able to reverse the reduced ability of IL-1 beta-treated islets to respond to an acute glucose challenge. NA dose-dependently reduced NO production induced by IL-1 beta. CONCLUSION: There is the protective effect of NA on IL-1 beta-induced damage to islets of Langerhans. The mechanism of this effect might be related to that NA stimulates islet cells replication and reduces NO production induced by IL-1 beta.

Animals↗

PubMed1996

[Application of the thoraco-umbilical flap for the repair of large infected wounds on the limb].

We have repaired large infected wounds on the limb in 18 cases using the thoraco-umbilical flap. Of them, 6 were island flaps and 12 were free flaps. The size of the flap ranged from 10 cm x 12 cm, to 10 cm x 40 cm. All flaps survived. The advantages of the flap were (1) rich blood supply providing good anti-infection property; (2) the muscle carried by the flap could be used to fill a bone cavity, aiding to cure osteomyelitis; (3) the flap could be made rather big and has long vascular pedicle that was flexible for transferring.

Adolescent↗

PubMed1996

[Different proteins in NRCF (nerve regeneration conditioned fluid) from the proximal and distal nerve stump].

80 SD rats were randomly divided into four groups of 20 each; electrostimulation of myeloneure (Group N); electrostimulation of the denervated muscle (Group M); Group C1; and Goup C2. The left lateral sciatic nerve of rats was exercised 2mm in length, and the distal nerve stump of the goup C2 and M and proximal nerve stamp of the Group C1 and N were each sulured into the silcon chamber with the opposile end ligated so that a 10mm was left between the stump and the blind end of chamber. At 3rd, 7th, 14th, 21th and 28th day after nerve transection and tube implantation, the fluid in the silicon tube was aspirated. The samples of fluid were spun and 4 microliters aliguots were taken from the super ratant. Then subjected to the aliquots were taken by phase system and assayed by Gel scan system. The results showed that the Group C2 and M had highly increase in the protein amount. Than that of group C1 and N in the range of 6-10 KD molecular weight. In 29-47 KD molecular weight range, the variety of protein molecular weight in aliguots of the Group N had and obvious increase compared with the group C1. In 16-29 KD, the protein amount in the Group M was more than that in the Group C2.

Animals↗

PubMed1996

[Subcellular location of blood group substances ABH using transmission electron microscopical immunocytochemistry technique].

The subcellular location of blood group substances ABH was studied by using transmission electron microscopical immunocytochemistry. The cells were the epithelial cells of both mucous membranes and glands of normal human stomach, duodenum and transverse colon. Both cellular ultrastructure and antigens should be well preserved in transmission electron microscopical immunocytochemistry. In this paper, various fixatives, embedding media and immunostaining methods were investigated and compared. The results indicate that the solution containing 2% paraformaldehyde and 0.2% glutaraldehyde (2PG) is the best fixative and Epon 812 medium is the best embedding medium for preserving ABH antigens and protecting cellular ultrastructure. Post-embedding immunogold staining technique is superior to pre-embedding immunoperoxidase staining.

ABO Blood-Group System↗

PubMed1996

Clinical observation on correcting malposition of fetus by electro-acupuncture.

Forty-eight cases of malposition of fetus were treated by electro-acupuncture, using Zhiyin (UB 67) points. 39 cases were corrected with a rate of 81.3%, the average session of treatment being 1.41. Two control groups were set up: moxibustion and blank control group. Statistical analysis shows that efficacy of electro-acupuncture is markedly superior to that of the blank. Sessions of electro-acupuncture were less than that of moxibustion and the difference was statistically significant, though there is no significant difference of efficacy between the two groups.

Acupuncture Points↗

PubMed1996

[Experimental studies of segmental bone defects treated by skeletal external fixation].

Bony tissue of an average of 13.6% of the original length (OL) was resected from the tibia shaft in 26 mature goats. The fracture ends were compressively fixed with skeletal external fixation (SEF). Simultaneously, upper metaphysiotomy was performed to lengthen the tibia with a lengthening rate of 1.0 mm/d and a total lengthening 20.14% of OL. The restoration of blood circulation and the hemodynamic changes during the repair process of the compressively fixed bone ends and the metaphysiotomy site were studied with angiography, microvascular cast, Chinese ink permeated transparent thick slide, and radioactive microsphere measurement of regional blood flow (RBF). It was found that there were abundant vascular networks in the lengthened zone. The blood vessels not only could keep up with the same lengthening rate of growing, but also were gradually converted into the Haversian system in the newly formed cortex of the lengthened area. In the 2nd week after the cessation of bone lengthening, the RBF of the lengthened zone reached the maximum (54.56 +/- 8.53 ml/mm/100 g). It was also found that in the 7th postoperative week, the vessels of the cortex of the osteotomy shortening ends could grow across the space between them and anastomose with each other. The RBF at this time was 31.82 +/- 2.85 ml/mm/100 g. In the 12th week after operation, the RBF was still 2 times higher than that of the normal cortex (3.02 +/- 0.13 ml/mm/100 g). The primary healing could be observed under the wellreduction and stable compressive external fixation. These findings provide a theoretical basis for the clinical application of SEF for the treatment of tibial shaft defects or nonunion associated with limb shortening.

Animals↗

PubMed1996

[Therapeutic effect of THAM on lactic acidosis of severe brain injury].

The presence of lactic acidosis in the cerebral spinal fluid of 50 patients with severe head injury was studied. The GCS scores of these patients were < or = 8. The patients were divided into two groups. We treated 25 patients with a dose of 4 to 5 ml/kg of THAM infused intravenously 2 to 3 times for daily administration. Other 25 patients who were not treated with THAM served as a control group. In each case, a ventricular pressure monitoring device was installed. The ICP was the contineously recorded. In addition, laboratory study, including lactate, pH, HCO-3 and BE in CSF was performed. THAM infusion was associated with improved survival, decreased ICP as compared to that in the control group. We believe that THAM treatment may significantly improve the prognosis of presence of lactic acidosis as a result of severe head injury.

Acidosis, Lactic↗

PubMed1996

[Immunogenicity of recombinant S. typhimurium ex. pressing a hybrid antigen of Plasmodium falciparum].

We have expressed a 74-peptide hybrid Plasmodium falciparum antigen as fusion protein in attenuated Salmonella typhimurium SL3261. Live organisms were orally immunized Rabbits with a dose of 2 x 10(9)cfu. Specific anti-serum were detected by ELISA after immunization. Obvious Delayed type hypersensitivity (DTH) could be induced by PfAg and GZ-C antigen. The recombinant vaccine had no evident side-effects to the hosts. Our studies indicate that attenuated Salmonella typhimurium SL3261 can express synthetic P. falciparum antigen with several epitopes and live organisms can activate special cell-mediated immunity and humoral immunity.

Animals↗