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Biomedical subjects

Y Sun

Publications and source records attributed to Y Sun.

At least 559 records · Page 31Linked to original sources
PubMed1998

[Effect of tail suspension on mitochondrial Ca2+ and Mg2+ and parameters of electron microscopic morphometry in rats' skeletal muscle].

Changes of mitochondrial Ca2+, mitochondrial Mg2+ and parameters of electron microscopic morphometry in rats' skeletal muscle after 15 or 30 d tail suspension were observed. The results showed that mitochondrial Ca2+ [correction of Ma2+] mitochondrial Mg2+ increased and morphometry of mitochondrial in skeletal muscle showed that volume density (Vv), surface density (Sv), numerical density (Nv) increased. Mean volume (V) decreased. Specific surface increased in soleus muscle, while that parameter remain unchanged in gastrocnemus musles. It suggests that these changes may be denoted to the decrease of muscular contractive function in simulated weightlessness.

Animals↗
PubMed1998

[Application and characteristics of macroreticular resin in purification study of different effective ingredients in Chinese medicines].

OBJECTIVE: To evaluate the possibility of applying macroreticular resin to the purification of different effective ingredients in Chinese medicines and study its working characteristics. METHOD: Four samples (water extracts of four single Chinese medicinal materials) containing alkaloids, anthraquinones, water soluble phenols and inorganic salts were employed. RESULT: LD605 resin is able to adsorb different effective ingredients except inorganic salts. CONCLUSION: Purification of Chinese compound prescriptions can be achieved by means of macroreticular resin.

Adsorption↗
PubMed1998

[Compatible leaching effect of Concha Ostreae and some commonly-used Chinese medicinal materials].

OBJECTIVE: Based on a study of Concha Ostreae, to provide some reference for the rational approach to leaching mineral drugs. METHOD: Taking the change rates of compatible leaching and value of A as targets, the compatible leaching effect of Concha Ostreae with Radix et Rhizoma Rhei Praeparata, Radix Scutellariae, Pollen Typhae and Fructus Aurantii lmmaturus was studied. RESULT: If Concha Ostreae and the above cited medicinal herbs are decocted together, the yield of extract may be reduced to a certain extent, but the target composition of Radix et Rhizoma Rhei Praeparata and Fructus Aurantii lmmaturus remains intact, only the content of Radix Scutellariae baicalin may be influenced. CONCLUSION: The relationship of technology with preparation must be taken into consideration when making choice of the proper way to leach Concha Ostreae.

Animals↗
PubMed1998

[The relationship between severe burn injury and systemic inflammatory response syndrome].

OBJECTIVE: To study course of systemic inflammatory response syndrome (SIRS). METHODS: The relationship was observed between SIRS and the effect of burn injury on cellular and humoral immunity between survivors. Nonsurvivors were also compared. The gastric mucosal pHi was measured. RESULTS: The SIRS initiated 22 hours after burn injury and peaked 3 days to 7 days postburn. Compared to the survivors significan increase of content of TNF and decrease of content of G-CSF were detected in the nonsurvivors serum. Obvious immunosuppression could be found. In patients with SIRS accompanied with infection or organ failure, marked increase of mortality was seen. The value of pHi was very low. CONCLUSION: Severe burn injury can lead to the release of massive inflammatory mediators. The second insult such as infection can further amplify the process leading to a vicious cycle of inflammation which cause tissue damage and immunosuppression. To prevent MODS, early diagnosis and treatment including organ supply, use of antibacterial agents, oxygen supply and immunity therapy were necesary.

Adolescent↗
PubMed1998

[Isolation and observation of ciliated cells from guinea pig's nasal epithelium].

OBJECTIVE: To investigate nasal physiological function at a cellular level and to establish a method for isolating single ciliated cells from guinea pig's nasal epithelium. METHODS: The ciliated cells were isolated by means of mechanical dissociation after papain treatment and a differential interference contrast (DIC) microscope was used for 1000-fold observation (objective lens: 100-fold; eye piece: 10-fold). RESULTS: A total of 12,587 single ciliated cells could be isolated from nasal epithelium of each guinea pig. The criteria for good viability of isolated nasal ciliated cells include: (1) actively motile cilia; (2) a smooth cytoplasmic membrane; (3) cytoplasm in a state of translucence (birefringence); (4) cells neither swollen nor shrunk. With short term culture at room temperature, the isolated nasal ciliated cells retained a good viability for 2-9 hours or longer. The living ciliated cells showed swing motions of cilia with fast and slow phases at a rate of 51-119 times per minute. CONCLUSION: A method for isolating ciliated cells from guinea pig's nasal epithelium and a criteria for good viability of isolated ciliated cells have been established. Ciliary motion pattern and ciliary beating frequency were also studied.

Animals↗
PubMed1998

[The study on the acoustic-phonetic features of marginal velopharyngeal closure].

OBJECTIVE: To study the acoustic-phonetic features of the cleft patients with marginal velopharyngeal closure. METHODS: The acoustic-phonetic features of 17 cleft patients with marginal velopharyngeal closure were analyzed with USSA sound spectrograph, contrasted by the features of 28 cleft patients with velopharyngeal incompetence and 18 patients with velopharyngeal competence. RESULTS: The manifestations of single vowel spectrum differ from that of the same vowel in sentence for MVPC patients. There are extra formants or strong nasal formants in a number of vowels spectrums in sentence, while they do not occur on single vowel spectrum. The spike and stop gap in the spectrograms of stops and affricatives may be absent or existing occasionally, and the noise energy in the lowest frequency area in the spectrograms of aspirated consonants may be watched or not. CONCLUSION: Acoustic analysis is very valuable to evaluate the state of marginal velopharyngeal closure. Analyzing the acoustic features of multiple vowels and consonants, and comparing the resonance characteristics of single vowel with the same vowel in continuous speech simultaneously are emphasized.

Acoustics↗
PubMed1998

[A study on the characteristics of articulation for functional speech problem after cleft palate surgery].

OBJECTIVE: To analyze the characterisctics of articulatory errors for the patients with speech problem and whose anatomic or physiologic defect such as velopharyngeal insufficiency were not indicated after cleft palate surgery. METHODS: Fifty patients with functional speech problem outlined above were tested using articulation test in chinese. The frequency of articulatory errors of all consonants was calculated. The interrelativity of the rate of affricates and plosives errors was analyzed. RESULTS: The frequency of affricates (j. z. ch. zh. et al) errors was higher than plosive's (b.d.g.k. et al). The difference of the rate of affricates and plosives errors was significant, statiscally (P < 0.001). CONCLUSION: It is suggested that the frequency of affricates errors was principal in this type of patients. They will be cured by speech training.

Adolescent↗
PubMed1998

[Inhalation sedation with nitrous oxide in dental extraction].

OBJECTIVE: To study the advantages of nitrous oxide sedation in teeth extraction. METHODS: 112 patients were randomly allocated to four groups: 1) 60 mmol/L nitrous oxide, 2) 60 mmol/L nitrous oxide with estazolam, 3) 40 mmol/L nitrous oxide, 4) 40 mmol/L nitrous oxide with estazolam. The nitrous oxide was used for conscious sedation as an adjunct to local anaesthesia. 53 patients of control group underwent dental extraction with local anaesthesia only. RESULTS: The postoperative MDAS scores of experimental group decreased and was significantly superior to control group (P < 0.01). The patients of experimental group showed a certain levels of sedation and partial amnesia. 97 of the 112 patients (86.62%) preferred inhalation sedation with nitrous oxide. There was no difference between the anxiolytic effects, sedative effects, amnestic effects of the four groups (P > 0.05). Estazolam as preoperative medieation did not show obvious coeffect with nitrous oxide. CONCLUSION: Inhalation sedation with nitrous oxide can provide effects of goodquality antianxiery, sadation, amnesia in dental extraction.

Adult↗
PubMed1998

[Clinical application of transesophageal intraluminal ultrasonography to the esophageal carcinoma].

OBJECTIVE: To study the value of transesophageal echo probe (TEEP) in preoperative staging of esophageal carcinoma. METHOD: Between September 1996 and August 1997, 32 patients (22 men and 10 women) with esophageal carcinoma, aged 49 to 72 years (mean age, 55.2 years), underwent surgery. Preoperative examinations included upper gastrointestinal series, endoscopy, and TEEP. Seven of these patients also received CT scan. Resected specimens of the esophagus and lymph nodes were examined histopathologically, and the results of TEEP and CT were compared with intraoperative macroscopic findings and pathologic results. RESULT: The tumor length measured by gastroscopy, TEEP and pathology was 4.524 +/- 1.806 cm, 5.269 +/- 1.916 cm, and 5.345 +/- 1.901 cm, respectively. There was a significant difference between the results of gastroscopy and those of pathology (P < 0.05), but no significant difference was seen between the results of TEEP and those of pathology (P > 0.05). The accuracy of TEEP for predicting T and N staging was 80.6% (25/31) and 77.3% (34/44), respectively. The accuracy of CT for predicting T staging was only 42.9%. CONCLUSION: TEEP is a reliable method for the preoperative TN-staging of esophageal carcinoma and it is more accurate than CT. TEEP is more accurate than gastroscopy in measuring the length of esophageal cancer. In our experience, the procedure is safe without any complications.

Aged↗
PubMed1998

[Myopic regression after photorefractive keratectomy].

OBJECTIVE: To investigate myopic regression after excimer laser photorefractive keratectomy (PRK) in patients with myopia. METHODS: 103 eyes with regression (>or= -1.00 D) found in the follow-up for more than 1 year were included in this study. The preoperative spherical equivalent was -4.00 - -14.50 D (-8.72 +/- 2.65 D). Patients were divided into two groups: (1) moderate myopia (-4.00 - -7.90 D) and (2) high myopia (>or= -8.00 D). RESULTS: A significant positive correlation was found between regression and the extent of attempted correction, the rate of regression in high myopia group was 6.93% and that in moderate group, 1.17%. The rate of regression in older age group was higher than that in younger cases. (P < 0.01). Relatively severe haze under the corneal epithelium often accompanies the regression, and decrease of the dosage of topical corticosteroid application or its withdrawal because of the development of corticosteroid ocular hypertention could lead to the regression. The stability of the refraction is not related to the difference in sex. The regression is often accompanied by the increase in K value. CONCLUSION: The regression is significantly related to the extent of attempted correction, patients' age, corneal haze and topical application of corticosteroid.

Adrenal Cortex Hormones↗
PubMed1998

[The coinfection of hepatitis C virus with hepatitis G virus and its reaction to interferon treatment].

HGV RNA was detected in 60 cases of hepatitis C patients and its positive rate was 23.3%, also the HGV infection was more frequent in chronic hepatitis C patients than in acute hepatitis C, and was only detected in hepatitis C patients who experienced transfusion of blood or blood products. These results indicated that transfusion was the main transmission route for HGV infection. HGV infection could shorten the incubation period of post-transfusion hepatitis C, but it would not worsen the status of the disease. The coinfection of HCV and HGV did not interfere the effect of interferon treatment on hepatitis C patients either in normalization of ALT or the elimination of HCV.

Adult↗
PubMed1998

Electroretinographic oscillatory potentials in different aged rats: an analysis in the domains of time and frequency.

OBJECTIVES: Electroretinographic Oscillatory Potentials (Ops) are considered to be the optimal parameter to study the retinal circulation disturbances the present we compared parameters of OPs between different aged rats under dark adaptation. METHODS: The scotopic ERG were performed in anaesthetized rats aged 3, 12, 24 months. According a window of collective power spectrum field of the OPs was isolated by using the FFT and IFFT of the spectrum analysis program. The parameters in the time and frequency domains were calculated. RESULTS: Results showed that the amplitudes of wavelets and the summed amplitudes of OPs declined with the increase of age. A reduction of the total power and dominated power of OPs was also found after the FFT. But implicit time of each OP and dominant frequency did not change obviously. CONCLUSIONS: The present study indicated that change of OPs of rat might be related to senile degeneration of the retina and circulative deficiency in retina in elder rats.

Aging↗
PubMed1998

[A correlate study on the first cervical vertebra and mandibular growth:A comparison of Shanghai females between 12 and 15 years old]

OBJECTIVE:To study the correlation between the cervical vertebra and mandibular growth and to reveal the intrinsic rule of the progress of individual growth, especially the trend of craniofacial development.METHODS:The morphological features of the first cervical vertebra and certain variables of craniofacial in lateral cephalometric radiographs from Shanghai females between 12 and 15 years old were measured and correlated. A set of normal values of the atlas vertebra shape of Shanghai 12 and 15 years old females were established.RESULTS:There was a significant correlation between D1 and AP of the first cervical vertebra and the direction of mandibular growth at the age of 12. But the association between atlas size ratio (AP/D1) and the mandibular growth is more notable than either AP or D1. When the atlas size ratio increased, a reduction of the amount of mandibular horizontal growth was showed, and the mandibular rotated backward; on the contrary, when the atlas size ratio decreased, the amount of mandibular horizontal growth increased and the mandibular rotated forward. CONCLUSION: The first cervical vertebra can be used as an indicator to predict the mandibular growth.

Journal Article↗
PubMed1998

[Study on the maturation of cervical vertebra for 208 cases Shanghai adolescents growth]

OBJECTIVE:To establish a set of normal values of maturation stages of cervical vertebra for Shanghai adolescents and to provide valid reference index for assessing skeletal age while making diagnosis and treatment plan.METHODS:208 Shanghai adolescents from 11 to 15 years of age were investigated by lateral cephalometric radiographs. The growth status and the relationship of C2-C5 cervical vertebra were observed. RESULTS:The anterior and posterior vertical heights and areas of C2-C5 cervical vertebra increased progressively along with the age, the shapes of cervical vertebra bodies varied regularly. Although female goes into the young quick growing period 2 years earlier than male, the shape changes have no difference between gender. The established standard values of maturation stages of cervical vertebra for Shanghai 11-15 years old adolescents revealed that the growth and development of Shanghai adolescents are getting earlier when comparing with that of GuangDong province. CONCLUSION: The morphological variation of cervical vertebra can be used as an indicator of skeletal age to determine adolescents' growth and development status.

Journal Article↗
PubMed1998

[Three-dimensional volumetric display--a new application of frequency up-conversion].

This paper discusses the present research situation and the application prospect of 3-D volumetric display technology. The possible usability and science significance of frequency up-conversion in 3-D volumetric display field are also demonstrated systematically. In ZBLAN: Pr, Yb glasses, we primarily demonstrated and achieved a new application of frequency up-conversion three dimensional volumetric display, using the two-frequency up-conversion of the rare earth ions. The efficiency of luminescence of Pr was enhanced much by the energy transfer between Pr and Yb ions.

English Abstract↗
PubMed1998

[Indirect sensitized upconversion in Tm3+ and Yb3+ codoped non-crystal pentaphosphate].

We report the blue upconversion luminescence of Tm3+ and Yb3+ codoped non-crystal pentaphosphate pumped by -798nm laser diode. The samples were directly excited to 3F4 level of Tm3+ ion. Two energy transfer processes between Tm3+ and Yb3+ contribute mainly to the population of 1G4 level of Tm3+. Phonon plays an important role in the upconversion process.

English Abstract↗
PubMed1998

CG island methylation changes near the GSTP1 gene in prostatic intraepithelial neoplasia.

Prostate intraepithelial neoplasia (PIN) is a purported prostate cancer precursor lesion and a candidate biomarker for efficacy assessment in prostate cancer chemoprevention trials. Loss of expression of the pi-class glutathione S-transferase enzyme GSTP1, which is associated with the hypermethylation of deoxycytidine residues in the 5'-regulatory CG island region of the GSTP1 gene, is a near-universal finding in human prostate cancer. GSTP1 expression was assessed by immunohistochemistry in 60 high-grade PIN samples adjacent to and distant from prostate adenocarcinoma. Whereas abundant enzyme polypeptide expression was evident in all normal prostatic tissues, all samples of high-grade PIN and adenocarcinoma were completely devoid of GSTP1. DNA from 10 high-grade PIN lesions was analyzed for GSTP1 CG island methylation changes using a PCR technique targeting a polymorphic (ATAAA)n repeat sequence in the promoter region of the GSTP1 gene. Somatic GSTP1 CG island methylation changes were detected in DNA from 7 of the 10 PIN lesions. Allele discrimination was possible for 5 of the 10 DNA samples: 2 of the 5 samples exhibited DNA methylation changes at both alleles; whereas 3 samples displayed no DNA methylation changes at either allele. GSTP1 CG island methylation changes were present in each of the five homozygous samples. Hypermethylation of the 5'-regulatory region of the GSTP1 gene may serve as an important molecular genetic biomarker for both prostate cancer and PIN. The finding of frequent GSTP1 methylation changes in PIN and prostate cancer supports a role for PIN lesions as a prostate cancer precursor and may provide insight to the molecular pathogenesis of prostate cancer.

Adenocarcinoma↗