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Biomedical subjects

X Ke

Publications and source records attributed to X Ke.

32 records · Page 2Linked to original sources
PubMed1999

Evaluation of the use of a questionnaire to detect hearing loss in babies in China.

A questionnaire was used to screen hearing of 1020 babies 6-8 months in China. All babies failing the questionnaire and 10% of those who passed were tested using auditory brainstem audiometry (ABR). Babies with unilateral or bilateral hearing thresholds 30 dBnHL or more were investigated to determine the cause of the hearing impairment. Sixty-seven failing the questionnaire were tested and 23 were confirmed to have a hearing loss, 20 with bilateral hearing impairment. The causes were: 13 otitis media with effusion (OME), one hypoxia, one genetic and five unknown. One child with an OME related hearing loss passed the screen. The sensitivity of the questionnaire was estimated to be 70%, specificity 96%.

Acoustic Impedance Tests↗
PubMed1999

Double-blind intervention trial on modulation of ozone effects on pulmonary function by antioxidant supplements.

The aim of this study was to investigate whether the acute effects of ozone on lung function could be modulated by antioxidant vitamin supplementation in a placebo-controlled study. Lung function was measured in Dutch bicyclists (n = 38) before and after each training session on a number of occasions (n = 380) during the summer of 1996. The vitamin group (n = 20) received 100 mg of vitamin E and 500 mg of vitamin C daily for 15 weeks. The average ozone concentration during exercise was 77 microg/m3 (range, 14-186 microg/m3). After exclusion of subjects with insufficient compliance from the analysis, a difference in ozone exposure of 100 microg/m3 decreased forced expiratory volume in 1 second (FEV1) 95 ml (95% confidence interval (CI) -265 to -53) in the placebo group and 1 ml (95% CI -94 to 132) in the vitamin group; for forced vital capacity, the change was -125 ml (95% CI -384 to -36) in the placebo group and -42 ml (95% CI -130 to 35) in the vitamin group. The differences in ozone effect on lung function between the groups were statistically significant. The results suggest that supplementation with the antioxidant vitamins C and E confers partial protection against the acute effects of ozone on FEV1 and forced vital capacity in cyclists.

Adolescent↗
PubMed1999

[An analysis of autologous peripheral stem cell transplantation for hematological malignancies].

OBJECTIVE: To summarize the data of autologous peripheral stem cell transplantation (APBSCT) for 49 hematological malignancies patients. METHODS: Forty-nine patients, 18 with acute myeloid leukemia, (AML) 10 acute lymphoblastic leukemia(ALL), 14 multiple myeloma(MM), 6 non-Hodgkin's lymphoma(NHL) and 1 myelodysplastic syndrome(MDS RAEB-t) received APBSCT were retrospectively analyzed. RESULTS: Comparing to conventional chemotherapy, APBSCT can prolong the patients' disease-free survival(DFS) and overall survival (OS). The 3 and 5-year OS rates were 74.78% and 83.33% for AML/NHL; 38% and 19% for MM; 40% and 0 for ALL, respectively. The time of hematopoietic reconstitution was influenced by G-CSF administration significantly. The mean time of neutrophil recovering to 0.5 x 10(9)/L after APBSCT was +17.7 days in no G-CSF group, and +11.14 days in G-CSF group. Up to now, of the 49 patients, no APBSCT related death occur, 23 have died and 22 of them died of relapse. The most common transplantation related complications were fever, liver dysfunction and hypopotassemia, all of which can be cured by proper treatment. CONCLUSION: APBSCT can be safely performed in hematological malignancies.

Acute Disease↗
PubMed1999

[Aminoglycoside ototoxicity associated with mitochondrial DNA mutation].

OBJECTIVE: To confirm the effect of genetic susceptibility to aminoglycoside ototoxicity. METHOD: Mitochondrial DNA (mtDNA) from 62 members of 9 aminoglycoside induced deafness families was analysed by PCR-Restriction endonuclease digestion. RESULT: The nucleotide 1555A-->G mutation in 12S rRNA gene of mtDNA was identified in 20 members of 5 families. CONCLUSION: These findings indicate that this mutation is a molecular basis for genetic susceptibility to the ototoxic effect of aminoglycosides. The relationship between the audiovestibular changes and genetic susceptibility to aminoglycoside ototoxicity and the pathogenetic mechanism of susceptible deafness are discussed. The possibility that other gene mutations can also predispose to aminoglycoside ototoxicity is proposed.

Adolescent↗
PubMed1998

Position 120-123, a potential active site of trichosanthin.

Trichosanthin (TCS) is a type-I ribosome-inactivating protein (RIP) with wide spectrum of biological and pharmacological activities. In the present study, a potential site on the TCS molecule (position 120-123) is identified which may be important for the biological activities of TCS. By using site-directed mutagenesis, position 120-123 of TCS was either deleted or changed from Lys-Ile-Arg-Glu (hydrophilic) to Ser-Ala-Gly-Gly (hydrophobic). Deletion of these residues rendered a TCS molecule completely deprived of ribosome inactivating activity, while hydrophobic replacement caused 4000-fold decrease in ribosome inactivating activity. The abortifacient activity of these two mutants was retained with decreased potency. This implies that position 120-123 of the native TCS molecule plays a critical role in maintaining its biological activity.

Abortifacient Agents, Nonsteroidal↗
PubMed1998

A solid-state NMR study of protein hydration and stability.

PURPOSE: The mobility of protein in powders at different hydration levels was studied in relation to aggregation and activity. METHODS: Magic angle spinning 13C, 15N, 1H, 2H, and 17O NMR techniques were used to determine changes in the mobility of surface residues in proteins as a function of hydration and related to changes in activity. NMR relaxation measurements of high frequency (omega0, T1) and low frequency (omega1,T1p) motions have been carried out on lyophilized DNase, insulin and lysozyme stored at different relative humidities. Moisture-induced aggregation and enzymatic activity of the lyophilized proteins was determined by high performance size exclusion chromatography and bioassays. RESULTS: There was little change in T1p observed with increasing humidity. The results show, however, that there is a decrease in T1 for DNase, insulin and lysozyme at relative humidities ranging from 0-98%, and we propose that the reduction in T1 is related to the aggregation susceptibility of proteins during storage at different humidities. The water mobility was determined directly using 17O NMR experiments. We found that as the amount of weakly-bound water increases, the protein surface mobility decreases and is coupled with increased aggregation. Aggregation measurements at different humidities were correlated with bioassays for lysozyme and found to be consistent with the hydration data. CONCLUSIONS: Mobility of protein molecules was determined by solid-state NMR over a wide range of % RH and it was found that water content leads to a change in mobility of protein molecules. The aggregation and activity of proteins were strongly correlated to change in molecular mobility.

Carbon Isotopes↗
PubMed1998

Role of the Ped gene and apoptosis genes in control of preimplantation development.

PURPOSE: The properties of the mouse Ped gene and the genes that mediate apoptosis in mediating preimplantation embryonic survival were reviewed. METHODS: Preimplantation mouse oocytes and embryos were evaluated microscopically and biochemically for rate of development, degree of fragmentation, and gene expression to correlate these characteristics with embryo mortality, Biochemical assays included PCR for DNA analysis, RT-PCR for mRNA analysis, immuno-PCR for protein analysis, and TUNEL assay for assessment of apoptosis. RESULTS: Using the mouse as a model system we have identified a gene that controls the rate of development, the Ped gene. The Ped gene product is a class Ib major histocompatibility complex protein called the Qa-2 antigen. Research to understand the molecular mechanisms of Ped gene action and to identify the human homologue of the Ped gene is under way. We have also shown using the mouse model, that fragmented embryos show the morphological and biochemical characteristics of apoptosis. Genes in the two major gene families that regulate apoptosis, the caspase and Bcl-2 families, are expressed in mouse oocytes and preimplantation embryos. CONCLUSIONS: Preimplantation embryonic survival depends on two major morphological parameters: rate of development and degree of fragmentation. A fast rate of development and a low degree of fragmentation lead to a better chance of producing live offspring. Both rate of development and degree of fragmentation are genetically controlled, the former by the Ped gene and the latter most likely by genes that mediate apoptosis. It seems probable that regulation of apoptosis will prove to be a major mechanism that mediates oocyte and preimplantation embryonic survival.

Animals↗
PubMed1998

[Changes in serum levels of total amino acids in young children with congenital heart diseases].

OBJECTIVE: To study the implication of early surgical operation on the improvement of protein malnutrition in young children with congenital heart diseases. METHODS: Sixteen kinds of serum free amino acids were determined with an automatic analyzer for 72 cases with congenital heart diseases before and after surgical operation and 51 healthy children. RESULTS: Serum total amount of essential amino acids reduced in children with congenital heart diseases, mainly of branch-chained amino acids, especially significant in young ones. Serum amino acids restored to normal level one month after surgical operation. CONCLUSION: There existed protein malnutrition in children with congenital heart diseases, especially in young ones. Surgical operation for them in a suitable time will improve their protein nutritional status.

Adolescent↗
PubMed1997

[The application of transmeatal exploratory tympanotomy].

Transmeatal exploratory tympanotomy has been used traditionally for the surgical treatment of conductive deafness. With 8 cases of the middle and inner ear diseases diagnosed and surgical managed successfully with this approach, the extended applications of this procedure were illustrated, which included: 1. conductive deafness with cause undetermined, 2. post traumatic conductive deafness with intact tympanic membrane, 3. suspected primary space occupying lesion of tympanum. 4. perilymphatic fistula, and 5. cerebrospinal fluid otorrhea. The key consideration and advantage of this approach were also discussed in this paper.

Adolescent↗
PubMed1997

[Effects of breakfast quality on blood glucose level in students].

Thirty freshmen were randomly enrolled and their blood glucose levels in fasting and one, two and three and a half hours after breakfast with three different kinds of calorie allocation were determined to explore the effects of breakfast quality on their blood glucose levels. Results showed that changes of blood glucose level curve in fasting students was low and horizontal. Blood glucose level after breakfast with carbohydrate as major composition increased significantly one hour after breakfast but could not last for a long time, and decreased rapidly one hour later and down to approximately normal three and a half hours after breakfast. Blood glucose level after breakfast with higher lipid and protein composition increased gradually and maintained at a medium level, and was still higher three and a half hours after breakfast than that with other breakfast; and blood glucose level one hour after breakfast with reasonable calorie allocation increased more rapidly and was kept at a higher and more stable level, and still approximated to that with higher lipid and protein composition three and a half hours after breakfast. It suggests that reasonable allocation of nutrients in breakfast plays an important role in maintaining blood glucose level in the morning, and unhealthy fasting habit in the morning should be abandoned.

Adolescent↗
PubMed1995

CTLA4 mediates antigen-specific apoptosis of human T cells.

The regulation of T cell-mediated immune responses requires a balance between amplification and generation of effector function and subsequent selective termination by clonal deletion. Although apoptosis of previously activated T cells can be induced by signaling of the tumor necrosis factor receptor family, these molecules do not appear to regulate T-cell clonal deletion in an antigen-specific fashion. We demonstrate that cross-linking of the inducible T-cell surface molecule CTLA4 can mediate apoptosis of previously activated human T lymphocytes. This function appears to be antigen-restricted, since a concomitant signal T-cell receptor signal is required. Regulation of this pathway may provide a novel therapeutic strategy to delete antigen-specific activated T cells.

Abatacept↗
PubMed1995

[Vibratory acoustic stimulation test in fetal hearing monitor].

In order to seek an antepartum diagnosis of hearing impairment in fetus, a vibratory acoustic stimulation test (VAST) was carried out with 57 women who were pregnant 27 weeks and an ABR test was carried out with their 57 newborn babies. The results showed: (1) On or after the 27th week the fetus would have the function of hearing. (2) The reliability of VAST was high (two positive rates were 87.7% and 89.5%) and the VAST was safe. (3) There was a correlation between fetal VAST and newborn ABR (P < 0.05). We consider that VAST is a simple, safe and effective measure for fetal hearing screening.

Acoustic Stimulation↗
PubMed1993

[Deficiency and excess syndrome of chronic atrophic gastritis].

In this study, Syndrome of Deficiency revealed that gastric acid secretion, cellular immunity, hematopoietic and synthetic metabolism were all decreased. The RBC, Hb, TG, HDL-C, CD8, infection rate of HP, the degree of atypical hyperplasia and the staining intensity of PNA were different for Spleen-Kidney-Deficiency syndrome from spleen-Deficiency syndrome, the former was lower than the latter, while LPO was higher and ESR was faster for the former. Syndrome of Excess revealed that the serum gastrin level was higher, humoral immunity and catabolic metabolism were increased, its blood was in hyperviscosity and hypercoagulation state. The Qi Stagnation with Blood Stasis was different from the Qi stagnation alone which including the atrophic degree of the former was severer, the ESR was faster than that of the later. The Heat Stagnation (HS), retention of Dampness (RD) and Damp-Heat (DH) have some difference. First, for secretion of gastric acid. HS was the lowest, DH the next, RD the third. Second, for the level of LPO, HS was the highest.

Adult↗