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Biomedical subjects

Y Zhao

Publications and source records attributed to Y Zhao.

At least 595 records · Page 33Linked to original sources
PubMed1998

[Autopsies of coal workers with chronic bronchitis].

OBJECTIVE: To study the pathological features of chronic bronchitis in coal miners. METHODS: Pathological specimens collected in postmortem examinations for 180 deceased coal miners were analyzed. RESULTS: Among the 180 deceased coal miners, there were 155 cases of chronic bronchitis, with a prevalence rate of 86.1%, mainly affecting bronchia and bronchiole. No correlation between chronic bronchitis and coal worker pneumoconiosis was found. The most apparent features of chronic bronchitis in coal miners include dust deposition and dust cell infiltration on the walls of bronchi at all levels, and dust fibrosis around the bronchial walls, with the most severe pathological change of dust deposition on the respiratory bronchiole. CONCLUSION: Most of the coal miners with chronic bronchitis (accounting for 80.0% of the total) manifested dust deposition and mixture of dust deposition and inflammation. Simple inflammatory bronchitis was rare.

Bronchi↗
PubMed1998

Primary Sjögren's syndrome and its lymphoid malignancy: a report of four cases.

OBJECTIVE: To evaluate the incidence and spectrum of malignancy of primary Sjögren's syndrome (pSS). METHODS: 250 pSS who were followed-up in Peking Union Medical College (PUMC) Hospital were analyzed. RESULTS: Four of them were diagnosed with histopathological findings of 2 non-Hodgkin Lymphoma, 1 AILD, 1 multiple myeloma. Two died of secondary infection while receiving chemotherapy for lymphoma, 2 remained remitted. CONCLUSIONS: The risk factors were persistent enlargement of major salivary glands, appearance of monoclonal serum lg, and disappearance of auto antibodies.

Adult↗
PubMed1998

[Study on the activity of fibroblast in hypertrophic scar].

To determine the state of fibroblast during the process of development of hypertrophic scar (HS), 40 specimens of HS in different periods were collected. The expressions of prolifrating cell nuclear antigen (PCNA) and Ag-protein in nucleolar organizer regions (Ag NORs) as well as the content of total amino acids in the tissues were examined. The hypertrophic scar of 1st and 3rd month old, the expression of PCND and Ag NORs were the highest. In the 9th and 12th month old, althrough PCNA was nearly negative, but the expression of Ag NORs was low. The content of total amino acid was increased gradually as HS developed but the increase of amount of hydroxyproline was markedly slowed down in 9 month old HS. It was suggested that: (1) in the developing process of HS the proecess of overproliferation of fibroblasts was short and limitted in 1-3 months period in the process of wound lealing; (2) the synthesis of collagen was nearly stopped at 6 months, but that of other extracellular matrix such as fibronectin and proteoglycan might be continued to aggregate after 12 months.

Adult↗
PubMed1998

In vivo color measurement of 410 maxillary anterior teeth.

OBJECTIVE: To make in vivo color measurements of maxillary anterior teeth. METHODS: A fiber-optic spectrophotometer (FMC-9204, Kunming, China) was used for in vivo color measurements of 410 healthy maxillary anterior teeth of 70 Kunming residents aged 18 to 70. The results were expressed by the CIE (Commission Internationale de L'Eclairage) L*A*B* system. RESULTS: The value of L* was positively correlated with L* = 42.74 + 0.14 x age; the value of A* was negatively correlated with age (A* = 1.73 - 0.03 x age). The color of the maxillary anterior teeth was related to tooth position: the central incisor had the highest value of L*, the canine had the lowest. The canine was also redder, yellower, and more saturated.

Adolescent↗
PubMed1998

[Dental fluorosis of brick tea type in rats].

To observe the dental fluorosis of brick tea type, 48 white rats were fed by 245 mg.L-1 of brick tea, respectively. The rat model of brick tea type fluorosis were successfully established after 90 days. Naked eye examination of rats' incisors showed that brick tea and sodium fluoride (as positive control) groups all suffered from dental fluorosis. Using the dissecting microscope, the scanning electron microscope, and the energy spectrum apparatus, we also proved that the high concentration of brick tea could cause dental fluorosis.

Animals↗
PubMed1998

[Relationship between ventricular arrhythmia and blood lipid in hypertensive patients with left ventricular hypertrophy].

The possible relationship among ventricular arrhythmia(VA), blood lipid(BL) and left ventricular hypertrophy(LVH) were investigated in 92 patients with essential hypertension(EH). The results showed that the incidence of VA and complex VA and ventricular tachycardia(VT) were significantly higher in EH with LVH than those in EH with non-LVH. The incidence of VA and complex VA and VT were highest in hypertensive patients with LVH accompanied with hyperlipemia(HL), and VA seemed closely related to left heart structure and BL. The results suggest that LVH and HL are the two additive risk factors of occurrence of VA in patients with EH.

Adult↗
PubMed1998

[Study of ozonization effects on mineral water components].

The disinfection effects of ozonization and its influences on chemical components of mineral water were investigated. The results showed that ozone at the level of 0.5 mg/L and with the exposure time of 5 minutes effectively destroyed bacteria in mineral water. High level ozone showed no strong influences on some beneficial components, such as strontium and metasilicate and on some main components, such as bicarbonate, hardness and alkalinity, but slightly elevated pH value. Ozonization reduced the contents of total dissolved solids and oxygen demand, and decomposed some reductive contaminants such as ammonia, cyanide and phenols. Ozonization will convert part of the bromide into hypobromite and bromate.

Escherichia coli↗
PubMed1998

[A study of immobilized enzyme-assisted semisynthesis of human insulin].

In this paper, a study on preparation of human insulin by immobilized enzyme-assisted semisynthesis is reported for the first time in our country. Porcine insulin with Thr(Bu(t)OB(t) catalyzed by immobilized trypsin has been converted into human insulin via a two-step transpeptidation. With the systematic technique of optimization, the rate of transpeptidation is 66%-70%. PAGE photometry is used to determine the conversion rate of semisynthesis. PAGE and C-terminal analysis of protein are adopted to identify the semisynthesis human insulin.

Enzymes, Immobilized↗
PubMed1998

[Improving the bonding strength of castable ceramic crowns].

To study the influence of bonding agent on fracture strength of Plat-II castable ceramic crowns bonded to molars, we tested the specimens in vitro with Panavia 21 resin bonding agent and porcelite dual cure cement. The results showed that the fracture loading (845.8 +/- 137.1 N) of crowns bonded with Panavia 21 bonding agent was higher than that (534.0 +/- 58.7 N) of crows bonded with porcelite dual cure cement. The difference between the two agents was statistically significant (P < 0.05). The crowns bonded with Panavia 21 agent had higher strength than bite forces. These suggest that costable ceramic crowns could be bonded with Panavia 21 resin agent in clinical practice.

Crowns↗
PubMed1998

[A biodistribution experiment on 125 I-VIP in mice].

This experiment was designed to investigate the biodistribution characters of 125 I-vasoactive intestinal peptide (VIP) with high specific activity in normal mice and the effect of VIP on the distributive test. After intravenous injection of 125 I-VIP, the mice were killed during 180 min. Blood, lungs, liver, intestine and kidneys were collected respectively and measured in 7 counter, finally the measurements of their radioactivity (cpm) were converted into ID%/g tissue and the results were expressed as mean+/-s. The effect on VIP on distributive test was evaluated by simultaneously injection of 125 I-VIP (74kBq) which contained 10,20 and 40 microgram VIP respectively; the mice were killed at 5 and 20 min. respectively, the collection of tissues and the management of data were the same as above. Most of the 125 I-VIP was distributed in the lungs rapidly, the radioactivity was mainly eliminated through kindneys; the T1/2 of activity in blood was shorter than 20 min; the difference in activity between liver and blood was not significant after 20 min. (P >0.05); the activity intestine remained lower during the experiment. The uptake of 125 I-VIP in lungs, liver and intestine was inhibited by VIP in dose dependence. The rates of inhibitory effectiveness of 10, 20 and 40 microgram VIP in lungs were 45.12%, 56.64% and 68.12% respectively at 5 min., and 53.65%, 71.03% and 79.03% respectively at 20 min. The present study indicated that the uptake of 125 I-VIP in various tissues of the mice possesses the character mediated by VIP receptor, 125 I-VIP is mainly accumulated by lungs, eliminated through kidneys, and the hepatobiliary system cannot remove it. The biodistribution character of 125 I-VIP is helpful to 131I (123I)-VIP imaging in the detection of gastrointestinal tumor.

Animals↗
PubMed1998

[Research on bending strength and fracture toughness of alumina-glass composite].

To develop a new ceramic material that can be machined and infiltrated with glass, a porous alumina blank sintered at 1350 degrees C was made of high purity, super fine alpha-alumina and then infiltrated with glass in this study. The density, bending strength and fracture toughness of the partially sintered alumina and alumina-glass composite were determined. The results indicated that the porous alumina density was 2.12 g/cm3, the three point bending strength 102 MPa, the fracture toughness 1.61 MPam1/2; that the alumina-glass composite density was 3.85 g/cm3, the three point bending strength 385 MPa, and the fracture toughness 4.05 MPam1/2. By SEM and EDXA analysis, lanthanum boroslicate glass was completely infiltrated into the 3 mm thick porous alumina blank for 6 h at 1150 degrees C. These suggest that the new developed alumina blank is suited for clinical use.

Aluminum Oxide↗
PubMed1998

[Effect of crystalling temperatures on microstructure of dental glass-ceramic].

To know well the effect of crystalling temperature on the microstructure of dental glass-ceramic, the parameters of microstructure such as the type of crystal, crystal percentage, crystal size and crystal form were investigated by altering crystalling temperatures and using scanning electronic microscope, energy dispersive X-ray analysis and X-ray diffraction techniques. The results showed that the crystalline phase was identified to be tetrasilicic fluromica, and the promotion of crystalling temperature contributed to the increased crystal percentage, crystal size and the transformation of crystal form from 830 degrees C to 950 degrees C.

Crystallization↗
PubMed1998

[The changes of plasma calcitonin gene-related peptide level in women with normal pregnancy and pregnancy induced hypertension].

OBJECTIVE: To study the change of calcitonin gene-related peptide (CGRP) concentrations in maternal plasma of the normal pregnant women and patients with pregnancy induced hypertension (PIH) and relationship with CGRP and pathogenesis of PIH. METHODS: The plasma levels of CGRP in 59 cases of normal pregnant women (normal pregnancy group), 57 cases of PIH (PIH group), and 10 cases of nonpregnant women (control group) were determined with a sensitive radioimmunoassay. RESULTS: Plasma CGRP levels in normal pregnancy group increased with advance for the gestational week, reached the peak value (76.84 +/- 27.75 ng/L) in late trimester; plasma CGRP levels in PIH group decreased with series degree of PIH, levels of CGRP in moderate (49.76 +/- 23.11 ng/L) and severe PIH (46.35 +/- 22.32 ng/L) were significantly lower than that in mild PIH (71.28 +/- 21.98 ng/L) and the normal late pregnancy, the differences were significant (P < 0.005). There was no correlation between CGRP levels and the mean arterial pressure (MAP). CONCLUSIONS: The change of CGRP may play an important role in the pathogenic mechanism of PIH.

Adult↗
PubMed1998

[Clinical study on reduction of postpartum bleeding in cesarean section by misoprostol].

OBJECTIVE: To observe the effects of misoprostol on reduction of postpartum bleeding in cesarcan section. METHODS: One hundred and eighty-two cesarean sections were randomized into three groups: misoprostol group (n = 60), 600 micrograms misoprostol was given orally when peritoneum was incised; misoprostol and oxytocin group (n = 64), 600 micrograms misoprostol was given orally and 20 IU oxytocin was injected into uterine muscle immediately after delivery of baby. Oxytocin group (n = 58), 20 IU oxytocin was injected into uterine muscle and 20 IU intravenous injection immediately after delivery of baby. The amount of bleeding within 2 hours after delivery was measured. RESULTS: The mean amount of bleeding in misoprostol group was 212 +/- 56.0 ml, in misoprostol and oxytocin group was 208 +/- 55.4 ml, oxytocin group was 345 +/- 64.7 ml, respectively. The difference was significant P < 0.01 between misoprostol group and oxytocin group, there was no differences between misoprostol group and misoprostol plus oxytocin group. CONCLUSION: Misoprostol is more effective in reduction of postpartum bleeding than that of oxytocin.

Abortifacient Agents, Nonsteroidal↗
PubMed1998

[Expression of endothelial nitric oxide synthase gene in placental villus of preeclampsia].

OBJECTIVE: To investigate the expression of endothelia nitric oxide synthase (eNOS) mRNA in the villus of preeclampsia and the relationship between eNOS and preeclampsia. METHODS: Dot blot, using DIG-labeled human eNOS cDNA probe, had been used to examine the expression of eNOS gene in placental tissues of 9 normotensive pregnancy and 9 preeclampsia women. By using Leica QWIN image disposal and analysis system Mean OD of every dot was assessed. RESULTS: The level of eNOS mRNA in placental villus was significantly lower in preeclampsia woman than that of control group (P < 0.001). CONCLUSION: The decrease of eNOS in placental villus of preeclampsia may be one of the causes for human placental dysfunction and high impedance of fetoplacental circulation in preeclampsia. It may play an improtant role in the genesis of pregnancy induced hypertension.

Adult↗
PubMed1998

[Study on gene of YRRM in azoospermia].

OBJECTIVE: To detect the abnormal YRRM gene in azoospermia and to explore the pattern of YRRM gene in Chinese men. METHODS: With the special primer for YRRM, the YRRM gene was analyzed using the PCR method. Extracting the testis total RNA, we performed the RT-PCR. The part of YRRM gene was sequenced. RESULTS: No amplification band of YRRM gene was noted in 4 of 74 Chinese men with azoospermia (5.4%). The YRRM gene was obviously expressed in the testis of man and showed a 500 bp cDNA fragment. The cDNA and genomic DNA were different because the intron. We found that Chinese people only have YRRM1 pattern of gene, and the sequence of YRRM gene of Chinese men shows that the composition of the nucleotide is same as YRRM1 gene. CONCLUSION: These cases of abnormal YRRM gene may result in male infertility, YRRM gene and azoospermia is the YRRM1 gene is polymouphase of racial.

Adult↗