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Biomedical subjects

Y Zhou

Publications and source records attributed to Y Zhou.

At least 649 records · Page 36Linked to original sources
PubMed1997

[Clonning and sequencing of partial gene of hepatitis G virus (HGV) from Nanjing of China].

Partial gene of hepatitis G virus (HGV) was cloned and sequenced from the serum of a patient with post-transfusion hepatitis C in Nanjing of China by reverse transcription-polymerase chain reaction (RT-PCR). The sequence showed 89.09%, 92.12%, 87.27%, 93.94% nucleotide identity over the corresponding region of HGU44402, HGU45966, HGU36380 in America and HGV isolate in Hebei Province of China respectively. Forty patients with post-transfusion hepatitis C and thirty patients with hepatitis non A-E were detected for HGV RNA by RT-PCR, the HGV RNA positive rate were 10.00% and 6.67% respectively.

Base Sequence↗
PubMed1997

[Correlation between the serum levels of interleukin-2 and soluble interleukin-2 receptor and the response to immunosuppressive therapy in severe aplastic anemia patients].

OBJECTIVE: To explore factors influencing the effectiveness of immunosuppressive therapy in severe aplastic anemia (SAA). METHODS: The serum levels of interleukin-2 (IL-2) and soluble IL-2 receptor (sIL-2R) of 22 SAA patients and 15 normal controls were measured by immunoenzyme assay. RESULTS: Comparing with the normal controls, 40.9% and 63.6% of the SAA patients had higher serum levels of IL-2 (>840ng/L) and of sIL 2R (>320 x 10(3) U/L), respectively. Those who had higher IL-2 levels and higher sIL-2R levels got better responses to cyclosporin A(CsA) and CsA plus antilymphocyte globulin (ALG). CONCLUSION: The serum levels of IL-2 and sIL-2R were correlated with the responsiveness to immunosuppressive therapy in SAA patients and might be useful for directing treatment.

Adolescent↗
PubMed1997

[Study on ion chromatography (IC) for the low-molecular weight amines].

In this paper the retention behaviors of low-molecular weight amines (methylamine, dimethylamine, trimethylamine, ethylamine, propylamine sec-butylamine, n-butylamine, ethanolamine, diethanolamine, triethanolamine) on Ionpac CS12 column were for the first time studied with modern ion chromatograph. The column is usually used for routine analysis of inorganic cations and it strongly retains these organic amines. So they are difficult to be eluted by dilute aqueous HCl alone. The addition of acetonitrile (ACN) as a modifier can improve the peak shape and resolution. Influences of concentrations (ACN & HCl) on separation and detection were investigated separately and the chromatographic conditions were optimized. Aqueous solution of 20 mmol/L HCl containing 1% or 5% ACN (5% for higher molecular weight amines) was used as the eluant with a flow rate of 1.0 mL/min to optimize the column efficiency. In addition to methylamine, ethanolamine and diethanolamine, all other amines can well be separated from each other. According to the structure they may be divided into three classes: (a) methylamine, dimethylamine and trimethylamine; (b) diethanolamine and triethanolamine; (c) ethylamine, propylamine, sec-butylamine and n-butylamine. The three classes of mixtures were separately injected into the IC system and resolutions being obtained by the developed method were: (a) 1.25 and 1.52; (b) 1.20; (c) 2.45, 2.05 and 2.10 respectively. The new method is characterized by rapidity, convenience, sensitivity and simultaneous determination of some inorganic cations. It was separately used for determination of diethanolamine, triethanolamine, NH4+ in explosive samples and of Na+, K+, MgZ+, Ca2+ in water supply with satisfactory results. The retention mechanism of amines on CS12 column and effect of organic modifier were also preliminarily explored.

Biogenic Amines↗
PubMed1997

[New advances in liquid chromatography-chemiluminescence detection].

A review on the new development of chemiluminescence (CL) detection for liquid chromatography (LC) is presented. It covers CL detection systems (including luminol, peroxyoxalates, and other chemiluminescence reactions) combined with LC, the design of CL detectors, analytical methods for many kinds of inorganic, organic and biologic samples, applications and the trends of LC-CL in environmental, biomedical, life science and pharmaceutical analysis.

Chromatography, Liquid↗
PubMed1997

[Spectral study on the self-polymerizing reaction of N-diisopropyl phosphoryl amino acids].

By using polarization sensitive CARS method, five kinds of N-diisopropyl phosphoryl-alpha-amino acids are investigated. They polymerize themselves to form peptide at 55 degrees C for 40 hours. The vibration mode spectra prior and after the reaction are recorded. With the help of theoretical calculation, the configuration of these peptides are inferred to be trans form and the specificities vibration modes are assigned.

Amino Acids↗
PubMed1997

[Investigation and application of auto-circulative washing and sterilization cabinet for catheters].

The structure, working principle, and operation of a sterilizing cabinet with autocircle washing for catheters was introduced in this article, 100 catheters were tested. The result revealed that no incrustation, rusty spot or thrombus existed after washing, and that hepatitis virus had been killed thoroughly. This cabinet can save the operator's time, make the operation easy, and prevent cross infection.

Catheters, Indwelling↗
PubMed1997

Expression of testis angiotensin-converting enzyme is mediated by a cyclic AMP responsive element.

Testis angiotensin-converting enzyme (testis ACE), an ACE isozyme that plays an important role in male fertility, is transcribed from a unique promotor active only in developing spermatids. In vitro analysis suggests the importance of a cyclic AMP response element (CRE)-like region within the testis ACE promoter, and similar DNA motifs are important in the expression of a variety of testis-specific genes. In the present study, we examined the effects of mutations in the CRE-like element on testis ACE promoter activity in vivo using transgenic mice. Disruption of this element reduced reporter gene expression to near background levels. In contrast, conversion of the CRE-like element to a consensus CRE-binding site resulted in high level expression of the reporter gene specifically in the testis. These experiments prove that the CRE-like element is essential for testis ACE promoter activity, although it does not appear to be responsible for its tissue specificity. These data provide insight into how a phenotypically differentiated tissue, ie, male gem cells, regulate tissue-specific gene expression.

Animals↗
PubMed1997

Human cytotrophoblast differentiation/invasion is abnormal in pre-eclampsia.

During human placental development, cytotrophoblast stem cells differentiate and invade the uterus. Simultaneously, the cells modulate their expression of several classes of stage-specific antigens that mark transitions in the differentiation process and play a role in either uterine invasion (integrin cell-extracellular matrix receptors and matrix metalloproteinase-9) or immune interactions (HLA-G). The pregnancy disease pre-eclampsia is associated with shallow cytotrophoblast invasion. Previously we showed, by immunofluorescence localization on placental tissue, that in pre-eclampsia invasive cytotrophoblasts fail to properly modulate their integrin repertoire. This finding suggests possible abnormalities in the differentiation pathway that leads to uterine invasion. Here we used a culture system that supports this differentiation process to compare the differentiative and invasive potential of cytotrophoblasts obtained from control (n = 8, 22 to 38 weeks) and pre-eclamptic (n = 9, 24 to 38 weeks) placentas. In culture, the cells from pre-eclamptic placentas failed to properly modulate alpha1 integrin and matrix metalloproteinase-9 expression at the protein and mRNA levels. Their invasive potential was also greatly reduced. Likewise, the cells failed to up-regulate HLA-G protein and mRNA expression. These results suggest that defective cytotrophoblast differentiation/invasion can have significant consequences to the outcome of human pregnancy (ie, development of pre-eclampsia) and that, by the time delivery becomes necessary, the defect is not reversed by removing the cells from the maternal environment.

Adult↗
PubMed1997

[Study on the recognition and evolutionary genetics of the courtship song of species in Drosphila nasuta species subgroup].

The subgroup of Drosophila nasuta consists of 14 species, subspecies and taxa. It has a wide distribution in area of Indo-Pacific Ocean. The courtship song of species in nasuta subgroup is recorded for the first time in the paper. Some parameters of temporal pattern of pulse song were measured: the inter burst interval (IBI), the interpulse interval (IPI), the length of a pulse train (PTL), the number of pulses in a train (PN), the length of a pulse (PL) and the length of a cycle (CL). Computer analysis techniques were used to make spectral analysis of sine song. A three-dimensional power spectra of the sound was made. In this subgroup, the male of D. pulauna and Taxon-F didn't produce any sound signals during courtship, suggesting that the visual stimuli play an important role in mating process. By analysing the courtship sound signals of other species, subspecies and taxa, the sounds produced by courting male could be described as pulse song or as sine song. By studying the sounds of intra- or interspecific F1 hybrids we have found that the parameters of the temporal pattern of pulse song, for example, the mean value of IPI is controlled by X-linked and autosomal polygene and the sine song frequency is predisposed to the maternity. The phylogenetic tree of the subgroup is constructed based on the temporal pattern of the pulse sounds in different species, subspecies and taxa. The relationship within the members of the Drosophila nasuta subgroup is discussed.

Animals↗
PubMed1997

Evolutionary regularity of acetabular dysplasia after reduction of developmental dislocation of the hip.

OBJECTIVE: To observe the developmental changes of the acetabulum after reduction of developmental dislocation of the hip and require evolutionary regularity of acetabular dysplasia. METHODS: A follow-up in an average of 7.4 years was carried out in 117 patients (161 hips) with developmental dislocation of the hip after reduction. By the series of X-ray films, acetabular index, acetabular-head index, Sharp's angle, ACM angle (Idelberger's angle) and anteversion were observed. At the same time, centre-head distance discrepancy was measured. RESULTS: Acetabular index returned to normal gradually as the time went by and significantly within one year after the reduction of developmental dislocation of the hip. The process of recovery was nearly stable three years later. Acetabular index in the dysplasia group was above 39 degrees before reduction and decreased slowly after the reduction. However, it was still up to 30 degrees after 3 years observation. The value of centre-head distance discrepancy decreased gradually as the years went by after reduction. CONCLUSIONS: If acetabular index before reduction is above 39 degrees and is still up to 30 degrees three years after reduction, acetabular dysplasia can be diagnosed.

Acetabulum↗
PubMed1997

[Gastric mucosal hemodynamics of prehepatic portal hypertensive rat model].

OBJECTIVE: To observe the changes of gastric mucosal hemodynamics and discuss the possible regulatory factors of prehepatic portal hypertensive rat. METHOD: Prehepatic portal hypertensive (PHT) rat model was produced by various degree of portal vein constriction, and gastric mucosal hemodynamics was measured by radioactive microsphere technique. Statistical analysis was performed by ANOVA, the student t test, and linear correlation. RESULT: The gastric mucosal blood flow was significantly reduced in PHT rats, whereas the blood flow in submucosa, muscular layer prominently increased. The resistance of mucosal vasculature was elevated in PHT rats, however, that of submucosa and muscular layer was decreased remarkably. There was a negative correlation between the gastric mucosal blood flow and portal pressure. CONCLUSION: The gastric mucosa of prehepatic portal hypertensive rat model is poorly perfused prominently. It may be due to the increased mucosal vascular resistance and elevated portal pressure.

Animals↗
PubMed1997

[Influence of antisense N-ras 1 gene on smooth muscle cell proliferation after arterial injury].

OBJECTIVES: To develop a new way to prevent the process of restenosis after arterial injury, we transfered the recombinant antisense N-ras 1 gene to the iliac arteries of rabbits after injury and studied the influence of gene therapy with antisense N-ras 1 on the vascular segment. METHODS: The constructed recombinant antisense N-ras 1 gene to deliver into the iliac arteries of rabbits after injury. The rabbits were randomly divided into gene therapy group, vector group, and sense N-ras 1 control. The segments of treatment rabbits were analysed by angiography of vessels, pathological study, Northern blotting, and Western blotting technique. RESULTS: The minimum angiographic lumen diameter measured during gene therapy and at follow-up, for the gene therapy group (at 4 weeks) was 0.80 +/- 0.10mm and the vector control 0.35 +/- 0.13mm (P < 0.01). Histologically, the area of neointima measured, for gene the therapy group (at 4 weeks) was 0.43 +/- 0.05mm2, and the vector control group 0.82 +/- 0.03mm2 (P < 0.01). By using Northern blotting and Western blotting technique, we found that cell's ras mRNA of the vessel segments of gene local delivery was significantly lower than that of the control. Cell's p21 was significantly lower than that of the control. CONCLUSIONS: The antisense N-ras 1 inhibites VSMC proliferation. The result implicates the potential value in future gene therapy of restenosis.

Angioplasty, Balloon↗
PubMed1997

Preliminary study of the effects of metoprolol and propafenone on ventricular arrhythmia with positive ventricular late potential.

OBJECTIVE: To compare the effects of metoprolol and propafenone in patients with ventricular arrhythmia (VA) of positive ventricular late potential (VLP) and to discuss the effect of medicine on high risk VA. METHODS: 30 A total of 128 patients (78 males and 50 females) with VA of positive VLP were randomly divided into 3 groups. Groups A and B were given metoprolol and propafenone respectively, group C was given vitamin C as placebo. Twenty-four hours dynamic electrocardiogram and VLP were examined before treatment and 4 weeks after treatment. RESULTS: Propafenone could effectively control VA but could not reverse positive VLP to negative meanwhile it had proarrhythmia effect (2/40), metoprolol could effectively control VA (38/46) and reverse positive VLP to negative (39/46) with no obvious side effects. The dosage from 50 to 100 mg/day made no difference. VA and VLP had no significant changes in group C. CONCLUSIONS: Metoprolol is superior to other medicine for VA of positive VLP when the patients have no contraindication of preceptor blocking agents.

Adult↗
PubMed1997

[Spectral analysis of R-R intervals in adolesent persons during mental stress].

In this study, power spectrum analysis of the autoregressive model was used to quantitatively estimate the power spectrum of R-R intervals in adolesent during the state of the mental stress. The power spectrum density of the lower frequency (HF: 0.05-0.15 Hz) and the high frequency (HF: 0.15-0.5 Hz) component were acquired. The results showed that during the mental stress the HF component decreased significantly (P < 0.001) while the LF component increased relatively and the center frequency of the HF increased remarkably (P < 0.001). This suggests that the spectral analysis of heart rate variability (R-R interval) offers an efficient non-invasive method to assess the autonomic nerve activity of cardiovascular system during the stress condition.

Adult↗
PubMed1997

[A study on familial aggregation of hepatitis virus infection in Fujian province].

In nine disease surveillance points of Fujian Province, positive serum antibody against hepatitis A virus (anti-HAV), hepatitis B surface antigen (HBsAg), antibody against hepatitis Cvirus (anti-HCV) and antibody against hepatitis E virus (anti-HEV) in people of 1,237 families were determined and their distribution was analyzed to study familial aggregation of hepatitis virus infection by fitting to binomial distribution. Results showed that chi 2 of goodness-of-fit to binomial distribution was 49.89, 217.91 and 27.39 for anti-HAV, HBsAg and anti-HEV respectively, all with P < 0.001, indicating very obvious familial aggregation in HAV, HBV and HEV infection, with aggregation rates of 84.13%, 34.83% and 35.23% respectively. It suggests that familial aggregation is mainly caused by mother to infant transmission and horizontal transmission in families, and HEV infection can be transmitted through sex.

Binomial Distribution↗
PubMed1997

[Effects of perindopril on hypertension, serum angiotensin-I-converting enzyme activity and urine level of N-acetyl-beta-D-glucosaminidase].

Perindopril 4 mg once daily was given to 40 hypertensives for 4 weeks. The results showed that systolic and diastolic blood presure were decreased by 3.2 kPa (22.2 +/- 2.21-19.0 +/- 1.92 kPa) and 1.87 kPa (13.4 +/- 1.21-11.5 +/- 1.27 kPa), respectively. The total effective rate was 80%. Serum Angiotensin-I-converting enzyme activity in 30 patients was significantly decreased from 58.5 +/- 29.5 U to 18.2 +/- 16.2 U (P < 0.01). The urine level of N-acetyl-beta-D-glucosaminidase (NAG) in 27 patients significantly decreased from a prior level of 13.66 +/- 7.81 U.gCr-1 to 10.12 +/- 5.57 U.gCr-1 (P < 0.01). The side effects of perindopril were cough (7.5%), constipation (10%), dizziness (7.5%), flatulence (7.5%) and diarrhea (5%). We conclude that perindopril is a potent antihypertensive drug with significant prevention on hypertension-induced early renal damage.

Acetylglucosaminidase↗