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Biomedical subjects

X Tian

Publications and source records attributed to X Tian.

At least 127 records · Page 7Linked to original sources
PubMed1996

[The effect of cytokines on the liver necrosis].

OBJECTIVE: To investigate the effect of cytokines on liver necrosis. METHODS: We injected IL-1, IL-6, IFN gamma, TNF alpha with or without D-galactosamine (D-GAL) into the abdominal cavity of mice separately. RESULTS: There was no effect on hepatocyte of normal mice after injection of IL-1, IL-6, IFN gamma alone or together. The serum total bilirubin (TBIL) and liver necrosis of mice increased more markedly by using of TNF alpha, IL-6 or IFN gamma separately with D-GAL (TBIL: 46.2 +/- 10.6 micromol/L, 44.6 +/- 12.9 micromol/L, 41.9 +/- 14.9 micromol/L), then by D-GAL alone (TBIL: 27 +/- 11 micromol/L) also the serum TBIL of mice and liver necrosis also increased after injection of IL-1, IL-6 with D-GAL and TNF alpha. CONCLUSION: Cytokines like IL-1, IL-6, IFN gamma and TNF alpha joined the process of hepatocyte necrosis. They can enhance the degree of liver necrosis induced by D-GAL.

Animals↗
PubMed1995

Reduced densities of sodium-dependent [3H] hemicholinium-3 binding sites in hippocampus of developmental rats following perinatal low-level lead exposure.

We investigated the effect of perinatal, low-level lead exposure on [3H]hemicholinium-3 (HC-3) binding in the hippocampus of postnatal rat. Rat pups were maternally lead-exposed from gestational day 16 through postnatal day 28 (PN28). In control animals, the [3H]HC-3 binding sites increased from 7 fmol/mg protein at postnatal day 1 (PN1) to 14 and 35 fmol/mg protein at PN7 and PN14, respectively, and reached adult values of 50 fmol/mg protein, at PN21 and PN28. In lead-exposed litters, the [3H]HC-3 binding was reduced by 30-40% throughout the early postnatal development and remained 40% below control values in PN60 animals, one month after termination of lead exposure. The Pb-induced reduction in HC-3 binding was associated with a similar decrease in ChAT activity and was comparable to the effect of localized lesion of medial septum. Septal cell counts in the lead-exposed PN21 rats indicated a 22% reduction in the number of ChAT-immunoreactive cells in the medial septum/vertical diagonal band (MS/vDB) complex although cell numbers in the horizontal limb of the diagonal band (hDB) were not altered. These results suggest that perinatal, low-level lead exposure results in a reduced density of cholinergic nerve terminals in the hippocampus, either due to impaired development or degeneration of the cholinergic projection neurons in the MS/vDB complex.

Aging↗
PubMed1995

Biochemical and biophysical characteristics of mitochondria in the hypertrophic hearts from hypertensive rats.

A comparative study of the biochemical and biophysical characteristics of myocardial mitochondria was conducted in 16-weeks-old male stroke-prone spontaneously hypertensive rats (SHRsp) and normotensive Wistar-Kyoto control rats (WKY) (n = 6-12). Cardiac and ventricular weights of SHRsp were significantly higher than those of the WKY group. The average amounts of mitochondria (Mit) and sarcoplasmic reticulum (SR) proteins isolated from the ventricle of SHRsp were 37% and 25% greater, respectively, when compared with those of WKY. Mit cytochrome c oxidase activities (mumol/min/mg) were 4.63 +/- 0.71 for SHRsp and 5.55 +/- 0.50 for WKY myocardium (mean +/- s), so that the activity of the former was significantly reduced by 17% (P < 0.01). Mit Ca2+, Mg(2+)-ATPase activity (mumol/min/mg) of SHRsp was 24% lower than that of WKY myocardium (P < 0.01). The fluorescence polarization of myocardial Mit membrane labelled with DPH (1, 6-diphenyl-1, 3, 5-hexatriene) in hypertensive rats was not different from that in control rats. The spectra of intrinsic protein fluorescence in 300-380 nm at an excitation wavelength of 290 nm were also identical in the Mit or SR between SHRsp and WKY myocardium. An ultrastructural analysis showed that there were more new-born Mit with smaller volumes and an increased number of isolated Mit in vitro from SHRsp myocardium, while there were larger Mit volumes isolated from WKY myocardium. These results demonstrated the disorder of mitochondrial energy metabolism in hypertrophied myocardium from SHRsp, which may be involved in the abnormality of myocardial calcium metabolism.

Animals↗
PubMed1995

[Study on the relationship between uterine bleeding with intrauterine device and viral infection].

OBJECTIVE: To study the relationship between uterine bleeding with intrauterine device (IUD) and virus infection. METHODS: Virus isolation from endometrium samples both with IUD and without IUD was performed with rabbit kidney cell. The cell pathogen effect (CPE) directed the positive isolation. All isolated viruses were further identified by polymerase chain reaction (PCR) for human cytomegalovirus (HCMV) and by neutralizing test for herpes simplex virus type II (HSV-II). RESULTS: The endometrial samples were obtained from four groups: 113 patients with uterine bleeding with IUD; 109 healthy women, without uterine bleeding with IUD; 24 healthy women without IUD and 11 patients with uterine bleeding without IUD. The rates of virus isolation in four groups mentioned above were 59.29%, 19.27%, 16.67% and 63.64% respectively. The positive rates for HCMV and HSV-II in the four groups were 38.81%, 19.05%, 1/4, 3/7 and 23.88%, 23.87%, 1/4, 0.00% respectively. The unidentified viruses were 37.31%, 57.14%, 2/4 and 4/7 respectively. CONCLUSIONS: These results showed that some endometrial samples from both the bleeding groups and the controls were infected by HCMV and HSV-II. The incidence of virus infection in women with uterine bleeding with IUD was much higher than that of the controls, but similar to that is the patients with uterine bleeding without IUD. The results suggested that IUD could activate latent viruses (HCMV, HSV-II) infection and induce bleeding in certain conditions.

Adult↗
PubMed1995

Morphology and morphogenesis of hepatitis E virus (strain 87A).

The morphology and morphogenesis of isolated hepatitis E virus (HEV, strain 87A) were observed by electron microscopy (EM) and immune electron microscopy (IEM). Progressively developing local vesicles, virions accumulation in crystalline arrays and viroplasmic focus were seen in cytoplasm of infected cells. Replication and assembly of the new generation viruses were closely associated with rough endoplasmic reticulum (RER), inclusion body (IB) and microfibrils. Condensation and margination of chromatin, dispersion of nucleolar material, nuclear membrane alteration and masses of threads, granular material, and fibrillar component of the nucleus were frequently found. These changes revealed that this strain virus was confirmed as a RNA virus. The shape of the virus particles appeared approximately spherical whether the specimens were from the tissue culture crude suspension or purified highly concentrated preparations. The size of the virion was about 30 nm in diameter. The viral particles appeared unsmooth and irregular in outline. The spike-like structures may be occasionally observed on the surface of some viral capsides. The diameter of the strain 87 A virus is larger than the picornavirus and smaller than the calicivirus. This strain virus is different from classical calicivirus in without the cup-shaped surface depressions. The new genus, heparnavirus genus of caliciviridae family should be proposed for HEV.

Hepatitis E virus↗
PubMed1995

Morphometric evaluation on myocardial protection of cold crystalloid versus warm blood cardioplegia.

Twenty patients undergoing open-heart valve replacement were divided randomly into two groups in this study; intermittent perfusion of cold crystalloid (St. Thomas Hospital solution) with hypothermic cardiopulmonary bypass (CPB) (hypothermic group) and continuous administration of warm blood cardioplegia with normothermic CPB (normothermic group) respectively. Tissue samples were taken from the right atrium before weaning from CPB and from the right appendage 30 minutes after removal of the cross-clamp. The results of pathological study in these two groups were as follows: the structural alterations were most severe during the ischemic period in the hypothermic group. Damages of the myocardial mitochondria examined with transmission electron microscope were found more severe in the hypothermic group than in the normothermic group, and in the reperfusion period than in the ischemic period. Loss of integrity of the mitochondrial membrane could be noted during reperfusion in the hypothermic group. The surface to volume ratios of mitochondria of each period of the two groups were calculated by computerizing the microphotographs of the myocardium. It was shown that the average of the surface to volume ratios was smallest in the reperfusion period in the normothermic group. It seemed that the volumes of the mitochondria were larger in the warm group than in the cold one. Probably the results were due to more severe damages of the mitochondrial membranes in the hypothermic group, which led to the release of the contents out of the mitochondria while in the normothermic group, the sodium-pump was disordered and it made the mitochondria swell. Pathologically, blood cardioplegic perfusion with the use of normothermic CPB is a feasible method for myocardial protection in open-heart surgery.

Bicarbonates↗
PubMed1995

[An experimental study on homoharringtonine and glaucoma surgery].

PURPOSE: To test the inhibiting effect of a Chinese herbal drug. Homoharringtonine (HH) on the wound healing process at the filtering site in an experimental model. METHODS: Posterior sclerectomies were performed in 20 rabbits. Postoperatively one eye of each rabbit received subconjunctival injections of HH and fellow eye received saline injections in a randomized masked fashion. RESULTS: 14 days after operation, intraocular pressure decreased significantly compared with that of control (P < 0.05). The number of filtration blebs was greater than that of control (14/6). On pathological examination, the number of fibroblasts per square measure of cross section of tissue cut from filtration region that was diminished significantly compared with that of control (P < 0.01). There were no serious and permanent ocular toxic and side effects. CONCLUSIONS: The study suggests that the HH can inhibit cicatrization at the glaucoma filtering site, promote the formation of filtering blebs and provide a sufficient evidence for the further clinical use of HH.

Animals↗
PubMed1994

A parathyroid hormone antagonist stimulates epidermal proliferation and hair growth in mice.

The biologic action of parathyroid hormone (PTH)-related peptide (PTHrP) in normal skin was investigated in cultured human keratinocytes and in SKH-1 hairless mice. The results indicate that the PTHrP agonists human PTHrP-(1-34) and PTH(1-34) are potent inhibitors of epidermal cell proliferation. [Nle8,18,Tyr34]bovine PTH-(7-34)-amide, an antagonist of the PTH/PTHrP receptor, blocked the inhibitory effect of PTH-(1-34) in cultured keratinocytes. In the SKH-1 mice, PTH-(7-34) caused a 244% increase of [3H]thymidine incorporation into isolated epidermal DNA and 246% and 180% increases in the number and length of hair shafts, respectively. Thus, PTH and PTHrP may play an important role in the normal physiology of skin, and their agonists and antagonists have potentially wide therapeutic applications in the treatment of hyperproliferative skin disorders and aging skin and could also be effective in stimulating and maintaining hair growth.

Animals↗
PubMed1994

Neurite degeneration elicited by apolipoprotein E peptides.

Apolipoprotein E (apoE) has been localized to the neurofibrillary tangles and beta-amyloid-containing plaques found in the cortex of patients with Alzheimer's disease (AD) (14, 28), suggesting that apoE may play a role in this disorder. Recently, synthetic peptides containing a sequence within apoE (amino acids 141-155) were found to be cytotoxic to T lymphocytes in culture. In the present study, tandem presentation of the apoE sequence E141-155, as well as longer monomeric peptides that include this domain, was found to cause extensive and specific degeneration of neurites from embryonic chick sympathetic ganglia in vitro. These results, together with the observation of strong beta A4/apoE binding in vitro and the disproportionate occurrence of the epsilon 4 allele in both familial and sporadic AD patients, suggest that peptide sequences associated with apoE may contribute directly to neurodegenerative processes.

Animals↗
PubMed1994

Infection of human endothelial cells by Rickettsia rickettsii causes a significant reduction in the levels of key enzymes involved in protection against oxidative injury.

The activities of glucose-6-phosphate dehydrogenase, catalase, and glutathione peroxidase were significantly decreased in human endothelial cells infected with the obligate intracellular bacterium Rickettsia rickettsii, the causative agent of Rocky Mountain spotted fever. This observation lends additional support to our hypothesis implicating oxidative damage in endothelial cell injury caused by this microorganism.

Catalase↗
PubMed1994

[Laser suture lysis following trabeculectomy].

Trabeculectomies with tightly sutured scleral flap was performed on 49 eyes of 45 patients with angle closure or open angle glaucomas, the experimental group, of which 41 eyes underwent laser suture lysis subsequently. After a mean period of follow-up 14.7 months (12-36 months), the average intraocular pressure was decreased from pre-operative 5.93 kPa (44.5 mmHg) to post-operative 1.96 kPa (14.7mmHg). The experimental group of patients was compared with the control group, 41 eyes of 39 cases at the same period randomly undergoing trabeculectomy without laser suture lysis. The control rate of intraocular pressure is higher (89.8%:73.2%) and the incidence of ocular complications (such as, shallow anterior chamber, choroid detachment, hyphema, lens opacity) is significantly lower in the former group, showing that trabeculectomy with following laser suture lysis is a safe and effective anti-glaucoma surgery. The advantages, points for attention and experiences of laser suture lysis have been introduced in the paper.

Glaucoma↗
PubMed1994

[Mapping of full-length murine renin-2 gene].

A 24kb fragment containing full-length renin-2 gene and its flanking sequence was obtained by digesting the pKG-R2D with XhoI. This fragment was cleaved with single enzyme (EcoRI, KpnI and BamHI), and combined enzymes (EcoRI/KpnI, KpnI/BamHI and BamHI/EcoRI), respectively. The digests were electrophoresed on 0.8% agarose plates and transferred onto NC membranes. Radioactive probes of 735bp and 1400bp, templates of which were from half and full-length of renin-1 cDNA, respectively were used for Southern hybridization. On the basis of electrophoresis and hybridization patterns, a restriction map was constructed in this paper.

Animals↗
PubMed1993

[An observation on immunization reaction and serological effect of adsorbed purified pertussis vaccine].

An observation on immunization reaction and serological effect of adsorbed purified pertussis vaccine for the first time in China had been carried out in Zhengzhou. Phase I field trial had been conducted in 8 adults and 20 children in whom there was no local reaction and temperature reaction in adults and only mild temperature reaction (37.6 degrees C-38 degrees C) in 4 children. Phase II field trial showed that the adsorbed purified pertussis vaccine manifested trivial reaction, none developed severe temperature reaction (39.1 degrees C), and 8 person-times of moderate temperature reaction (38.1 degrees C-39.1 degrees C) occurred in 100 children after 3 doses. Whereas 2 person-times of severe reaction and 39 person-times of mild reaction occurred in 101 children after receiving the whole cell pertussis vaccine. None showed local severe reaction (5.1 cm) and 1 person-time of mild local reaction appeared at 48 hours after each of 3 doses of adsorbed purified pertussis vaccine (102, 102, 98 children, respectively); Whereas, 3 person-times of severe local reaction and 17 person-times of mild local reaction occurred after each of 3 doses of whole cell pertussis vaccine (97, 100, 97 children, respectively). Satisfactory immunogenicity of the adsorbed purified pertussis vaccine was confirmed. The high serum hemagglutinin titer was achieved in 90 children, the GMT reached 817 (9.16 for preimmunization), and titers reaching 1:320 and over (a level protecting human from being infected) accounted for 84.4 percent. The average levels of anti-LPF and anti-FHA antibodies in 60 and 53 persons attained to 24.17 +/- 3.9421 EU/ml and 38.85 +/- 7.2466 EU/ml, respectively.

Adhesins, Bacterial↗