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Biomedical subjects

Z Liu

Publications and source records attributed to Z Liu.

At least 793 records · Page 44Linked to original sources
PubMed1998

[Biological responses of a Streptomyces strain producing-Nikkomycin to space flight].

In order to see biological responses to the production of Nikkomycins in general and Nikkomycin X and Z in particular by space conditions, Streptomyces ansochromogenus, a Nikkomycins-producing strain, was carried onboard a satellite for 15 d in 1996. Several strains were isolated from the treated sample and found that the productivity of Nikkomycins in all was increased by 13-18 percent, and the proportion of Nikkomycin X and Z increased correspondingly. Besides, some biological properties of the isolated strains varied markedly.

Aminoglycosides↗
PubMed1998

Yin Duanmo, the person in medical history.

Yin Duanmo (Weijie) was graduated from Beiyang Medical College and worked in Canton Hospital as a doctor during the Late Qing Dynasty period. He was the first Chinese doctor to edit medical journals and to translate English medical works into Chinese independently. He and Dr. Sun Yatsen served in the same private clinic. He supported democratic revolution led by Sun Yatsen consistently. He was the first one graduated in China medical school and became a practitioner in Hong Kong.

China↗
PubMed1998

[Perilunate progressive instability of the wrist: a study of wrist dynamics].

OBJECTIVE: To study the changes in dynamics of wrist motor tendons after perilunate instability of the wrist. METHODS: 14 cadaver upper extremities were used. Excursions of the principle wrist and finger motor tendons were measured during wrist flexion-extension and radiolunar deviation was determined. Data were collected in the intact wrist, then in the wrist with stage I, II and III perilunate instability. The average moment arms of the tendons during wrist motion were calculated. RESULTS: The moment arms of the wrist flexors increased and those of the finger flexors decreased after instability. Increase in the moment arms dominated changes of radial side wrist motors, while decrease in the moment arms dominated ulnar wrist motors. Moment arms of the flexor carpi radialis tendon showed a consistent increase during wrist motion. CONCLUSION: The changes in wrist dynamics play an important role in clinical manifestations of perilunate instability. The significance of kinetic information on principle of treatment of the instability is discussed.

Biomechanical Phenomena↗
PubMed1998

[Diagnosis and treatment of iaotrogenic pseudoaneurysm].

OBJECTIVE: To improve the diagnosis and treatment of iaotrogenic pseudoaneurysm, 22 cases of iaotrogenic pseudoaneurysm were evaluated. METHODS: There were 19 men and 3 women, aged from 20 to 78 years(average 43.6 years). The clinical courses ranged from 7 hours to 13 months with an average duration of 4.7 months. 16 elective, and 3 emergency operations were performed. RESULTS: 19 cases were treated successfully, and one who had had compression repair failed received operative treatment. CONCLUSIONS: Iaotrogenic injury is the main cause of traumatic pseudoaneurysm, and can be prevented. Its treatment should accord to individual cases. Compression repair can be considered the first step for the management of postcatheterization pseudoaneurysms.

Adult↗
PubMed1998

[Multiple subpial transection in surgical treatment of intractable epilepsy].

OBJECTIVE: To increase the effect of epilepsy surgery, we use multiple subpial transection (MST) clinically on the basis of experimental study. METHOD: We analyzed the seizure type and course of 116 intractable epilepsy patients treated with MST and surgical technique were modified. RESULT: 100 patients were followed up for 1 to 5 years. Complete control of seizure was obtained in 62 patients (62%), significant reduction (over 75%) in 20 (20%), reduction (over 50%) in 12 (12%), and no change in 6 (6%). The total effective rate was 94%, and the significant effective rate was 82%. No functional defect was found in any patients. CONCLUSION: MST is a effective in surgical treatment of intractable epilepsy and can replace conventional methods. Combined bilateral frontal lobe MST and anterior callosotomy is a good way to treat intractable generalized epilepsy.

Adolescent↗
PubMed1998

[Bone scintigraphy in evaluating revascularization of the heat-devitalised autografts in adult dogs].

OBJECTIVE: To establish an animal model of microwave hyperthermic devitalization of long bones and compare bone scintigraphy of the devitalised bone with pathologic examination. METHOD: 16 Mongrel adult dogs were used. Enght 8 cm of one femur of each dog was exposed and isolated by heat-proof material. Two microwave antennas were inserted into the medullary cavity at a distance of 2.5 cm, and the bone was heated intermittently to maintain a surface temperature of 50 degrees C to 60 degrees C for 30 minutes. Bone scintigraphy was carried out at different postoperative time, combined with tetracycline labeling, microangiography with Indian ink and HE staining. RESULT: About 5 cm - 6 cm of segmental femur was deprived of blood supply after devitalization which was confirmed by microangiography and negative labeling of tetracyclines. At two weeks, the devitalised bone demonstrated a cold region on the scintiscan and no revascularization in microangiography. 12 - 16 weeks after the operation, partial devitalised bone was revascularized and HE staining showed widel bone resorption and minimum formation of new bone. However, the radionuclide uptakes of the devitalised segments were greater than those of the normal femurs. At one year, the devitalised segment was well (not completely) revascularised and showed evident appositional new bone formation. The scintigraphic bone-imaging was slightly lower than that of the normal femur. CONCLUSION: A strong positive scintiscan in early stage might demonstrate a good potential of revascularization of the heat-devitalised cortical bone rather than its viability. And the scintiscans of long-term follow-up more than one year should be more informative.

Angiography↗
PubMed1998

[Cellular apoptosis, proliferation and bcl-2 Bax expression in colorectal carcinoma and their association with tumor prognosis].

OBJECTIVE: To investigate the relationship between cellular apoptosis, proliferation and bcl-2/bax expression in the tissue of colorectal carcinoma and biological behavior of the tumor. METHOD: The apoptotic cells index (AI) in situ were identified by the terminal deoxynucleotidyl transfer-mediated dUTP-biotin nick end labeling (TUNEL) and immunohistologic staining for Ki-67 proliferation index (KI), bcl-2/bax protein expression was performed on archival material from 77 adenocarcinomas. RESULT: The mean AI and KI were 5.3/45.4 in early stage cancer, 5.6/48.7 in non-metastatic cancer, 6.6/55.3 in advanced cancer and 8.9/60.1 in cancer with distant metastasis respectively. There was a positive relationship between the AI and KI in each specimen. bcl-2 and bax was expressed as 54.5%, 74% in carcinoma and highly differentiated carcinoma. In the univariate analysis, significantly longer survival time was observed in the subgroup of bcl-2 positive carcinoma with low AI. In the multivariate analysis, tumor stage, tumor type, KI, and bcl-2 expression were independent risk factors for prognosis. CONCLUSION: The data indicate that abnormally exchanged AI/KI, bcl-2/bax expression appears to be an event associated with tumor progression and apoptosis might also reflect the proliferative activity of human colorectal carcinoma.

Apoptosis↗
PubMed1998

[Temporary keratoprosthesis for surgery of severe injuries of ocular anterior and posterior segments].

OBJECTIVE: To evaluate the treatment of severe ocular injuries of anterior and posterior segments with temporary keratoprosthesis used in combined operations. METHODS: With temporary keratoprosthesis a combined operation including pars plana vitrectomy, air-fluid exchange, silicone oil fill in, use of perfluorocarbon liquid, foreign body removal and partial penetrating keratoplasty was performed on 18 eyes of 18 patients with severe ocular injuries, and the postoperative changes and recovery were observed. RESULTS: All eyes were rescued, the visual acuity was increased in 12 eyes, above 0.1 being in 5 eyes, retinal detachment recurred in 3 of 10 eyes, vitreous opacity was present in 1 eye, secondary glaucoma in 1 eye, and atrophy in 1 eye as its preoperative status. CONCLUSION: Temporary keratoprosthesis used in the combined surgeries of anterior and posterior ocular segments is an effective method for treatment of severe ocular injuries.

Adolescent↗
PubMed1998

[Antiviral activity of antisense oligonucleotides to human cytomegalovirus].

Human cytomegalovirus(HCMV) is one of the important pathogens to human being. At present there is no specific antiviral drugs. In order to find an effective antisense phosphorothioate deoxyoligonucleotide(ASON) against--HCMV, the antiviral activity was observed in this study. Three ASON complementary to UL36 gene were synthesized according to immediate early gene sequence of HCMV, and the antiviral activity was evaluated in vitro using human embryonic lung cells as targeted cells of virus infections. The result showed that ASON targeting to splice donor had fairly strong antiviral activity. The specific ASON has sure antiviral activity. As a new means, it may be used to prevent and treat human CMV infections.

Antiviral Agents↗
PubMed1998

[Identificating of Actinomycetes producting activity of herbicide].

14 strains of Actinomycetes were isolated from soil samples collected in Yunnan, China. Experiments showed that they had activity of herbicide. In this paper, the morphological and chemotaxonomic characters of these strains were studied and they were identified as three genera of Actinomycetales respecitively, such as Streptomyces, Micromonospora and Nocardia.

Actinobacteria↗
PubMed1998

[Study on immobilized cells for producing alpha-amylase by using polyving alcohol as the carrier(II): The effect of fermentating conditions on the ability producing alpha-amylase of the cells immobilized with polyving alcohol as the corrier and continuous fermentation of the immobilized cells in CSTR].

The effects of fermentating conditions on the ability of immobilized cells with PVA as carrier for producing alpha-amylase were studied. The continuous fermentation with the immobilized cells were tested in continuous flow stirred tank reactor (CSTR). The results showed that the adaptability of the immobilized Bacillus substilis to pH increased after immobilization. In CSTR, the immobilized cells can be fermentated continuously for 360 hrs and the activity of alpha-amylase can be kept on the level of about 170 u/ml.

Bacillus↗
PubMed1998

[Expression characteristic of Bacillus thuringiensis cry1 gene in Pseudomonas fluorescens Pfx-18].

The plasmids of lepidopteran-specific Bacillus thuringiensis strain from our laboratory were hybridized with RNA probe of cry 1Aa EcoR I-F fragment labelled using DIG. Cry1 gene was located in 39.3 MD plasmid. The plasmid was digested with Hind III and analysed by southern blot. It appeared both 7.1 kb and of 6.5 kb positive bands. The 7.1 kb fragment was ligated to broad-host-range vector pSUP106 and transformed into Pseudomonas fluorescens Pfx-18. The cloned strain, LZP-1 was obtained. The plasmids of LZP-1 were analysed by PCR. The results showed that gene-type is cry1Ab. SDS-PAGE analysis demonstrated that LZP-1 could express 66 kD insecticidal crystal protein and some small molecular weight peptides. Bioassay showed that motality of 1000-fold diluted fermentation broth was 33% to 3rd instar plulella xyloslelly larvae.

Animals↗
PubMed1998

[The effect of pressure on the morphology of superior mesenteric vein in rabbits].

The effect of pressure on the morphology of the superior mesenteric vein of rabbits (SMV) was researched with the method of constant pressure fixation. The results indicate the morphology of SMV is similar to human umbilical cord vein. It looks like the structure of femoral artery of vein in many ways. Under constant pressure fixation (4 kPa), the internal elastic membrane of SMV is straightened, and the wall of SMV becomes thin, with its media thinning from 51.680 microns to 32.3260 microns. The long diameter of nucleus of the smooth muscles decreases from 1.9146 microns to 3.4980 microns, the short diameter of nucleus of the smooth muscles becomes from 0.7884 micron to 0.5228 micron. The direction of the tension on the smooth muscles is mainly longitudinal.

Animals↗
PubMed1998

[The effect of activity of smooth muscles on the relationship of circumferential stress-strain of superior mesenteric veins in rabbits].

The superior mesenteric veins (SMV) of 14 rabbits were divided into two groups for experiment of inflation pressure, namely the normal group and the inactivated smooth muscles group. The results showed that the relationship of circumferential stress-strain of SMV could be expressed with the exponential equation. Constant X2 is effected by the active condition of smooth muscles. The difference of the material constant X2 between the two groups was statistically significant (P < 0.05), but the difference of the material constant X1 between the two groups was not statistically significant (P > 0.05). These suggest that X2 is the parameter concerning the activity of smooth muscles.

Animals↗
PubMed1998

[Studies on the chemical constituents of the root of Pimpinella thellungiana].

Four compounds were isolated from the roots of Pimpinella thellungiana Wolff., their structures were identified as palmitic acid(I), 4-propenylphenol(II), pinoresinol(III), 2-methyl-2-hydroxy-5-methoxy berzo(d) hydrofuran-3-one(IV) by physicochemical constants and spectral analysis (UV, IR, MS, 1HNMR, 13CNMR, 13C-1HCOSY, DEPT), IV of them is a new compound, Pharmacological tests showed IV has a hypotensive effect.

Furans↗
PubMed1998

[The expression of human leukocyte antigen from peripheral blood of patients with herpetic keratitis].

PURPOSE: To understand the correlation between the expression of human leukocyte antigen from peripheral blood and herpetic keratitis so as to find the pathogenesis of HSK. METHODS: The expression of HLA-ABC, HLA-DR, HLA-DP, HLA-DQ from peripheral blood of 32 cases with herpes simplex keratitis (the stromatic and ulcer herpetic keratitis are 16 cases respectively), comparing with the normal people, were investigated by flow cytometry. RESULTS: The expression rate of HLA-ABC from peripheral blood of patients with herpetic keratitis (both the stromatic and ulcer groups) was lower, and the expression of HLA-DR and HLA-DP was higher than normal people. No difference was found between the stromatic and the ulcer herpetic keratitis in the expression of HLA-ABC, HLA-DR, HLA-DP, HLA-DQ. CONCLUSION: The immune model in patients with herpetic keratitis is different from normal people. The individual with this kind of immune model can not destroy the infected virus effectively, also show autoimmunization to cornea.

Adult↗