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Biomedical subjects

S Zhao

Publications and source records attributed to S Zhao.

At least 505 records · Page 28Linked to original sources
PubMed1991

The role of oxygen free radicals in myocardial ischemia/reperfusion injury.

A series of experiments have been done to investigate the role of oxygen free radicals in ischemia/reperfusion injury. The following results were found: Myocardial MDA content increased significantly after post-ischemic reperfusion in vivo and in vitro. A blockade of the xanthine oxidase pathway for free radical generation could provide effective protection against ischemia/reperfusion injury. Exogenous reactive oxygen intermediates H2O2, .OH and O2- could induce changes in the contractility and electrophysiological properties of myocardial cells similar to those seen in ischemia/reperfusion. An outburst of free radical generation was detected by ESR spectroscopy at low temperature (-173 degrees C) and with the spin trapping technique during the very early phase of reperfusion. The authors emphasize the important role of free radicals in the pathogenesis of myocardial ischemia/reperfusion injury.

Action Potentials↗
PubMed1991

Synthesis of (+/-)-N-2-methylpropyl-N-1'-methylacetonyl-nitrosamine.

N-2-methylpropyl-N-1-methylacetonyl-nitrosamine (NMAMPA), first isolated from moldy and normal foods, was synthesized by chemical means. The structure and molecular weight of the synthetic NMAMPA were elucidated by spectrometry. A combination of spectral and chromatographic data indicated that the synthetic NMAMPA is identical to that obtained naturally. Synthetic NMAMPA is a racemic modification, and a carcinogen which can induce esophageal and forestomach cancer in rats.

Carcinogens↗
PubMed1991

[Effects of semen Ziziphis Spinosae oil and Ziziphis Spinosae extract on the decrease of serum lipoprotein and inhibiton of platelet aggregation].

Our experiments have shown that oral administration of Semen Ziziphis Spinosae oil(SZSO) or Ziziphis Spinosae extract (ZSE) given to quails for 53 days can significantly reduce their TC, LDL and TG and markedly subdue the fatty degeneration in their livers. Also, SZSO pressed into the stomach of rats for five days can conspicuously inhibit their platelet aggregation, while ZSE cannot.

Animals↗
PubMed1991

[Clinical and experimental research of the treatment of chronic renal failure with shenshuaifang].

33 cases of chronic renal failure (CRF) patients were treated by coloclysis with Chinese medicine Shenshuaifang (SSF). The effective rate was 60.61%, the total effective rate was 87.88%. It showed significant difference in the total effective rate compared with the control group (P less than 0.05). Animal experiments showed SSF could slow down the rising of the blood Cr and BUN of the mice which suffered with CRF, and reduce their urine protein. Conclusion. SSF had good effect on lowering the blood Cr and BUN of the CRF patients, so it could delay the progress of CRF, and it's effect was better than the general medical conservative treatment.

Administration, Rectal↗
PubMed1991

[AIDS surveillance in Yunnan Province in China (1986-1990)].

We have carried out surveillance on HIV/AIDS in Yunnan Province since 1986. Up to 1990 total of 13,417 people has been surveyed and 373 HIV-positives were found in five area of whom two AIDS cases were reported to GPA WHO. The persons with HIV were attribute to intravenous drug users (IVDUs) and their wives, most of them came from IVDUs of Dehong Dai Race and Jingpo Race Automous Region Located in the border between China and Burma. No positive has been found in prostitutes, STD patients and blood donors.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Structure of the rhsA locus from Escherichia coli K-12 and comparison of rhsA with other members of the rhs multigene family.

The complete nucleotide sequence of the rhsA locus and selected portions of other members of the rhs multigene family of Escherichia coli K-12 have been determined. A definition of the limits of the rhsA and rhsC loci was established by comparing sequences from E. coli K-12 with sequences from an independent E. coli isolate whose DNA contains no homology to the rhs core. This comparison showed that rhsA comprises 8,249 base pairs (bp) in strain K-12 and that the Rhs0 strain, instead, contains an unrelated 32-bp sequence. Similarly, the K-12 rhsC locus is 9.6 kilobases in length and a 10-bp sequence resides at its location in the Rhs0 strain. The rhsA core, the highly conserved portion shared by all rhs loci, comprises a single open reading frame (ORF) 3,714 bp in length. The nucleotide sequence of the core ORF predicts an extremely hydrophilic 141-kilodalton peptide containing 28 repeats of a motif whose consensus is GxxxRYxYDxxGRL(I or T). One of the most novel aspects of the rhs family is the extension of the core ORF into the divergent adjacent region. Core extensions of rhsA, rhsB, rhsC, and rhsD add 139, 173, 159, and 177 codons to the carboxy termini of the respective core ORFs. For rhsA, the extended core protein would have a molecular mass of 156 kilodaltons. Core extensions of rhsB and rhsD are related, exhibiting 50.3% conservation of the predicted amino acid sequence. However, comparison of the core extensions of rhsA and rhsC at both the nucleotide and the predicted amino acid level reveals that each is highly divergent from the other three rhs loci. The highly divergent portion of the core extension is joined to the highly conserved core by a nine-codon segment of intermediate conservation. The rhsA and rhsC loci both contain partial repetitions of the core downstream from their primary cores. The question of whether the rhs loci should be considered accessory genetic elements is discussed but not resolved.

Amino Acid Sequence↗
PubMed1990

[Study on Ha-ras RFLPs in gastric carcinoma and normal tissue DNAs of Chinese individuals].

By using recombinant plasmid PHS-49 as a probe, BamHI restriction fragment length polymorphisms (RFLPs) was studied in tumour DNAs of 36 gastric carcinoma patients and normal tissue DNAs of 25 unaffected Chinese individuals. Ten alleles and eighteen genotypes for Ha-ras gene were found. Four "rare" restriction fragments of size less than 6 kilobase pairs (kb) are first reported for Ha-ras locus in present paper, we inferred that these alleles might be one of the characteristics of genetic polymorphisms in Chinese population. Moreover, the frequency of some "rare" alleles and genotypes occurred in gastric carcinoma samples is significantly higher than that occurred in normal individuals. The results of pedigree analysis for two patients showed that some heterozygotes carried three or four alleles. It suggested that there may be more than one copy of Ha-ras gene sequence existed in a chromosome. The possible causes of the phenomenon mentioned above were discussed.

Alleles↗
PubMed1990

[Studies of rapid detection of drug-resistance of Mycobacterium by gas chromatography].

This test is based on the physiologic character of mycobacterium, which produces carbon dioxide (CO2) during its growth, Löwenstein-Jensen media CO2 contents-were measured by gas chromatography for determining drug-resistance of mycobacteria. This was compared with the routine method. Seventy-eight mycobacteria were isolated from suspected tuberculosis patients for the experiment. Our data suggested that the accordance rates of both methods were 83.3%. Gas chromatography is a simple, rapid and accurate method for detecting drug-resistance. The results can be obtained twenty days earlier than by the routine method.

Antitubercular Agents↗
PubMed1989

10-year survival rate for patient with nasopharyngeal carcinoma after radiation therapy. Clinical analysis of 367 cases.

Of 1,344 patients with nasopharyngeal carcinoma treated during 1961-1965 at the Shanghai Cancer Hospital, 367 who survived over 10 years after radiation therapy, were analysed. The results showed that the patients with stage I, II nasopharyngeal carcinoma and those with stage III, IV, the 10-year survival rates were 41.5% and 22.8% respectively, the overall 10-year survival rate being 27.3%. The 10-year survival rate was higher for female patients than for males, and was not related to the age of the patients and the pathological type of this carcinoma. The optimal tumor dosage was thought to be 60-70 Gy 350(95.4%) out of the 367 patients received radiotherapy only once. The rest received repeated irradiation for recurrence. For the reirradiated patients, the 10-year survival rate was 13.5%. Most recurrences occurred 5 years after radiotherapy (12/17), and only 5 within 3 years.

Adolescent↗
PubMed1988

Antigenic analysis of three strains of Mycoplasma meleagridis of varying pathogenicity.

Three strains of Mycoplasma meleagridis of varying pathogenicity were characterized by conventional serologic methods and by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The three strains (RY-39A, MC-25B, and RY-39C) did not differ by cross agglutination, immunofluorescence and immunodiffusion tests. However, the strains differed in their protein patterns as determined by SDS-PAGE.

Animals↗
PubMed1987

Involvement of a nucleolar component, perichromonucleolin, in the condensation and decondensation of chromosomes.

A component of the nucleolar material, perichromonucleolin (PCN), was identified by a specific antiserum against nucleoli obtained from a scleroderma patient. The distribution and changes of PCN during the mitotic cycle were followed using this antiserum and indirect immunofluorescence microscopy. Based upon the behavior of PCN during mitosis, it could be differentiated into chromosomal and nonchromosomal portions. During prophase the former gradually associates with the surface of the condensing chromosomes and forms the coat or pellicle around the metaphase and anaphase chromosomes. This pellicle PCN is carried by the anaphase chromosomes to the daughter nuclei. During the time from telophase to interphase, the pellicle PCN dissociates from the decondensing chromosomes and is incorporated into the new nucleoli. The nonchromosomal PCN, after the breakdown of the nuclear membrane, distributes in the cytoplasmic region around the condensed chromosomes and diffuses into the cytoplasm during anaphase. Preliminary biochemical analysis by immunoblotting showed that the PCN consists of two main proteins with molecular masses of 36 kDa and 30 kDa.

Animals↗
PubMed1983

Long term survival of radiotherapy for esophageal cancer: analysis of 1136 patients surviving for more than 5 years.

One thousand one hundred and thirty-six patients surviving for more than five years after radiotherapy were studied. The important prognostic factors are: lesion less than 5 cm in length, lesion located in the upper-third segment and lesion that is radiosensitive. The radiation dose given to long term survivors varies greatly, i.e., 2700 to 9300 rad. Yet, for the sensitive type of lesion, doses lower than 5000 rad could also effect a cure. The delivery of an optimum dose determined by serial examinations during radiotherapy could improve the result of treatment. For local recurrent lesions, the value of a second course of radiation is extremely limited and surgery is the only means to offer a cure. For metastasis in the lymph nodes, radiation offers some hope of cure, although the long term outcome may not be satisfactory. For second primary cancer of the esophagus, aggressive radiation still gives encouraging results.

China↗
PubMedDate not supplied

Ultrasmall superparamagnetic iron oxide particles (AMI 227) as a blood pool contrast agent for MR angiography: experimental study in rabbits.

The purpose of this study was to evaluate the contribution of an ultrasmall superparamagnetic iron oxide particles (USPIOs) based contrast agent (AMI 227), in a transverse three-dimensional time-of-flight TONE MR angiography sequence of abdominal aorta in rabbits. The main goal was to assess improvement in the visualization of small arteries such as renal arteries, when using such a sequence. Imaging experiments were performed on a 1.5 T magnet, using a transverse 3D time-of-flight (TOF) tilted optimized nonsaturating excitation (TONE) sequence with magnetization transfer suppression. The contrast media used were composed of a USPIO core surrounded by a dextran-surfactant (AMI 227). Different concentrations of AMI 227 were evaluated in 12 rabbits. Concentrations varied within the range 8.5-34 micromol Fe/kg - bw: 8.5 micromol Fe/kg (three rabbits); 17 micromol Fe/kg (three rabbits); 25.5 micromol Fe/kg (three rabbits); 34 micromol Fe/kg (three rabbits). A visual analysis based on the improvement of visualization of small arteries (renal arteries) on MIP images and a quantitative analysis based on the percentage of contrast enhancement of the aorta plotted against distance in the slab from the top edge of the acquisition volume were obtained. A signal-to-noise ratio enhancement of the distal part of the aorta and only improvement in the delineation of the renal arteries were noted when using low concentrations of the contrast media. A loss of signal-to-noise ratio of the aorta and a decrease in arterial visualization were respectively noted with higher concentration of contrast media. In this experimental study, using a transverse three-dimensional TOF TONE MR angiography sequence of renal arteries, in which sequence the saturation effect is minimized, the use of AMI 227 allows only improvement in the delineation of small arteries when using low concentrations of contrast media.

Animals↗
PubMedDate not supplied

A device for subjecting vascular endothelial cells to both fluid shear stress and circumferential cyclic stretch.

The proposal of the role of mechanical forces as a localizing factor of atherosclerosis has led many researchers to investigate their effects on vascular endothelial cells. Most previous efforts have concentrated on either the fluid shear stress, which results from the flow of blood, or the circumferential "hoop" stretch, which results from the expansion of the artery during the cardiac cycle. In fact, arterial endothelial cells are subjected to both fluid shear stress and cyclic hoop stretch in vivo. Therefore, a more complete investigation of mechanical phenomena on endothelial cell behavior should include both kinds of mechanical stimuli. This study was undertaken to design an experimental apparatus that could subject cultured vascular endothelial cells to simultaneous physiologic levels of both shear stress and cyclic hoop stretch. The experimental apparatus consists of four cylindrical elastic tubes so that the following conditions may be studied: (a) static conditions: (b) shear stress only; (c) hoop stretch only; and (d) shear stress and hoop stretch. In order to establish the functional capabilities of the apparatus, bovine pulmonary artery endothelial cells were cultured in the tubes, and their morphology and f-actin structure were observed with confocal microscopy. The cells remained healthy and attached to the walls throughout the 24 hr experiment. Preliminary results indicated that the alignment of endothelial cells subjected to shear stress was significantly enhanced by the addition of hoop strain.

Actins↗
PubMedDate not supplied

Reliability and clinical validity of UM-CIDI DSM-III-R generalized anxiety disorder.

This is the first in a series of reports on the long-term test-retest reliability and procedural validity of the UM-CIDI, a modified version of the Composite International Diagnostic Interview used in the US National Comorbidity Survey (NCS). This report focuses on DSM-III-R Generalized Anxiety Disorder (GAD). The NCS administered the UM-CIDI to a nationally representative sample of 8098 respondents in the age range 15-54. A subsample of 36 respondents was subsequently selected for clinical reappraisal of GAD, consisting of reinterviewing by a clinical reappraisal interviewer who blindly readministered the GAD section of the UM-CIDI followed by an expanded version of the GAD section of the Structured Clinical Interview for DSM-III-R (SCID). The test-retest reliability of UM-CIDI/DSM-III-R lifetime GAD is Kappa = .53. When the requirement that the worries be excessive or unrealistic (A2) is removed, as in ICD-10 and partially in DSM-IV, reliability increases to Kappa = .78. The concordance between the baseline UM-CIDI diagnosis and the SCID diagnosis is Kappa = .35, while the cross-sectional concordance is Kappa = .47 (.66 when the Criterion A2 requirement is removed). Item-level analysis shows that lack of concordance between the UM-CIDI and the SCID is due largely to Criteria A2 and D. The A2 problem could be addressed either by deemphasizing the cognitive-evaluative component of GAD as in ICD-10, or by removing consideration of the term "unrealistic" from the criterion as in DSM-IV and more clearly specifying the meaning of the term "excessive". These options require further research on similarities and differences in risk factors, course, family history, and treatment response of more narrowly and broadly defined GAD. The Criterion D problem is due to lack of clarity in what constitutes a symptom occurring "often". This is clarified in DSM-IV. It is likely that this clarification will make it possible to develop more precisely structured questions to evaluate Criterion D in subsequent revisions of the UM-CIDI, resulting in improved reliability and validity.

Adolescent↗