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Biomedical subjects

Y Cui

Publications and source records attributed to Y Cui.

At least 217 records · Page 12Linked to original sources
PubMed1998

[A research for basic properties of distortion product otoacoustic emissions in normally hearing subjects].

With ILO-92 Otodynamics Analyzer, distortion product otoacoustic emissions (DPOAEs) at the 2 f1-f2 frequency were recorded from 86 normally hearing ears in response to four groups of different primary levels (L1 = L2 = 75 dB SPL; L1 = L2 = 65 dB SPL; L1 = L2 = 60 dB SPL; L1 = 65 dB SPL, L2 = 50 dB SPL). The average DPOAEs-gram demonstrated a bilobed contour with two peaks at approximately 1.5 kHz and 5 kHz and "notch" between 2.5 kHz and 3 kHz. Moreover, the contour of DPOAEs-gram had no obvious changes with sex, ear or primary stimulus levels differences. While the primary levels increased, the amplitude of DPOAEs gradually increased, which was about 55-65 dB SPL below the primary levels. At each frequency from 1-6 kHz, statistical analysis showed that there existed significantly different DPOAEs level under four groups of different primary stimulus levels.

Acoustic Stimulation↗
PubMed1998

[Effects of the leaf of Ginkgo biloba L. extract on blood rheology in animals].

OBJECTIVE: To observe the effects of the leaf of Ginkgo biloba extract(GBE) on viscosity and elasticity, coagulation of blood and aggregation of blood platelets. METHOD: The viscosity and elasticity of the whole blood in rats was determined using an in vitro method. The half inhibitory concentration of the drug inhibiting rabbit platelet aggregation was also determined using ADP as an inducer. The blood coagulation in mice was recorded with a coagulation analyser after GBE was administered by vein injection. RESULT: GBE significantly lengthened the recalcium time, lowered the increase ratios of viscosity and elasticity, and reduced the maximum viscosity and elasticity. At doses of 100 and 200 mg/kg administrated by vein injection GBE lengthened the coagulation time, reduced the fibriogenesis and clot retraction ratio significantly in mice. GBE can also inhibit rabbit platelet aggregation induced by ADP and promote the disband of the aggregated platelets. CONCLUSION: GBE is helpful in reducing viscosity and elasticity of the whole blood, slowing blood coagulation and inhibiting platelet aggregation.

Animals↗
PubMed1998

[Multiple subpial transection in surgical treatment of intractable epilepsy].

OBJECTIVE: To increase the effect of epilepsy surgery, we use multiple subpial transection (MST) clinically on the basis of experimental study. METHOD: We analyzed the seizure type and course of 116 intractable epilepsy patients treated with MST and surgical technique were modified. RESULT: 100 patients were followed up for 1 to 5 years. Complete control of seizure was obtained in 62 patients (62%), significant reduction (over 75%) in 20 (20%), reduction (over 50%) in 12 (12%), and no change in 6 (6%). The total effective rate was 94%, and the significant effective rate was 82%. No functional defect was found in any patients. CONCLUSION: MST is a effective in surgical treatment of intractable epilepsy and can replace conventional methods. Combined bilateral frontal lobe MST and anterior callosotomy is a good way to treat intractable generalized epilepsy.

Adolescent↗
PubMed1998

[The effects of Chinese medicine herb mixture on cell-mediated immune functions and four kinds of acute-phase reaction proteins in burn patients].

OBJECTIVE: To search for immunomodulators to improve postburn immune function disorder. METHOD: We studied the Chinese medicinal herbs. On the basis of previous data, we prepared a kind of Chinese medicinal herbal mixture and studied its effects in vivo and in vitro. RESULT: The mixture could restore the cell-mediated immune response such as the production of interleukin 2 and the T cell proliferative ability, and could also adjust the levels of serum acute-phase reaction proteins, i.e, haptoglobin, prealbumin, transferrin and alpha 1-acid glycoprotein. CONCLUSION: The Chinese herbal mixture showed immune regulatory effects on body defence imbalance and also on acute phase reaction proteins in burn patients.

Acute-Phase Proteins↗
PubMed1998

[The effects of graded spinal cord injuries on transcranial electric stimulation motor evoked potentials in the rat].

OBJECTIVE: To study the effects of graded spinal cord injury (SCI) on the motor evoked potentials (MEP) characteristics and the prognostic value of MEP for the motor function. METHOD: Modified Allen's method was used by weight drop force of 30 gcf, 50 gcf, 80 gcf and 100 gcf on the T(8 - 9) spinal cord of 40 SD rats in order to make SCI models. MEP was recorded continuously at L(1 - 2) epidurally and bilateral gastrocnemius muscles before and after the spinal cord lesion was produced (followed up for 1 month). The inclined plane and Tarlov technique were used to assess clinical neurological function. RESULT: The amplitude of rat's MEP changed significantly with graded SCI, the more sever the lesion, the lower the potentials. mMEP was more sensitive than scMEP, though the abolishment of mMEP soon after SCI didn't indicate that the animals could not regain ambulation. Changes in amplitude of scMEP recorded early after SCI were collaborate significantly with inclined plane (gamma = 0.9665, P < 0.01) and Tarlov scale (gamma = 0.8893, P < 0.01) assessed 1 month later, and can be used as a chronic measure parameter of motor function prognosis. scMEP still existed 1 month after SCI in 3 of 11 rats (27.3%) without any voluntary movement in bilateral hindlimbs, suggesting that some parts of conductive function still existed in the spinal cord. So it should be called "discomplete SCI". CONCLUSIONS: scMEP can be used as a reliable parameter for motor function prognosis, because it reflects objectively and sensitively the severity of central motor neurol fiber injury.

Animals↗
PubMed1998

The changes and significance of c-kit expression in the irradiated bone marrow of mice.

There have been only a few studies on the expression of c-kit in bone marrow after radiation and radiation-induced apoptosis of hematopoietic cells. LACA mice were examined after irradiation with a dose of 60Co gamma-rays. Using a light microscope, electron microscope, and immunohistochemistry, we studied radiation-induced apoptosis of hematopoietic cells and the expression of c-kit. We found that 5.5 Gy total body irradiation was a sublethal dose for LACA mice, induced suppression of leukocytes in blood, and of nucleated cells in bone marrow. Apoptosis of the hematopoietic cells occurred within 1 day after irradiation. The expression of c-kit was related to the recovery of hematopoiesis and played an important role in early hematopoiesis.

Animals↗
PubMed1998

Interleukin-3 gene expression in irradiated mouse bone marrow.

The expression of endogenous interleukin-3 (IL-3) gene in mouse bone marrow after whole body irradiation was assessed by immunocytochemistry, in situ hybridization (ISH), and in situ reverse transcription PCR (IS RT-PCR). The results showed obvious injury to the bone marrow followed by recovery 4 weeks after radiation. IL-3 protein was increased in the cytoplasm of recovering hematopoietic cells, especially at 21 days after radiation, while the mRNA was negative, except at 15 days when the mRNA was weakly positive by ISH. IS RT-PCR showed that IL-3 mRNA was strongly positive in the cytoplasm of recovering hematopoietic cells, especially at 10 to 15 days after radiation. We postulate that endogenous IL-3 gene may accelerate hematopoietic recovery in irradiated bone marrow and that IS RT-PCR may objectively report the regulation of IL-3 gene expression.

Animals↗
PubMed1997

Alteration of acidic lipids in human sera during the course of pregnancy: characteristic increase in the concentration of cholesterol sulfate.

In this study, we determined the concentrations of acidic lipids, including cholesterol sulfate (CS), sulfatide and GM3 ganglioside, in human sera of non-pregnant state and during the course of pregnancy. In human sera of non-pregnant women, GM3 was present at a concentration of 8 nmol/ml and the concentrations of CS and sulfatides were less than 20% of that of GM3. The concentration of sulfatides in sera at the second trimester of gestation was decreased, but CS gradually increased from the first to the third trimester of gestation with a correlation coefficient of 0.66, and a correlation between the concentration of CS and weeks of gestation (p<0.01). CS was also contained in the placental villi, and its concentration increased from the first to the third trimester of gestation, suggesting that placental CS is one of the source of CS in the blood by shedding.

Cholesterol Esters↗
PubMed1997

Loss of protein kinase C inhibition in the beta-T594M variant of the amiloride-sensitive Na+ channel.

We previously reported the presence of a novel variant (beta-T594M) of the amiloride-sensitive Na+ channel (ASSC) in which the threonine residue at position 594 in the beta-subunit has been replaced by a methionine residue. Electrophysiological studies of the ASSC on Epstein-Barr virus (EBV)-transformed lymphocytes carrying this variant showed that the 8-(4-chlorophenylthio) adenosine 3':5'-cyclic monophosphate (8cpt-cAMP)-induced responses were enhanced when compared to wild-type EBV-transformed lymphocytes. Furthermore, in wild-type EBV-transformed cells, the 8cpt-cAMP-induced response was totally blocked by the phorbol ester, phorbol 12-myristate 13-acetate (PMA). This inhibitory effect of PMA was blocked by a protein kinase C inhibitor, chelerythrine. We now have identified individuals who are homozygous for this variant, and showed that PMA had no effect on the 8cpt-cAMP-induced responses in the EBV-transformed lymphocytes from such individuals. Cells heterozygous for this variant showed mixed responses to PMA, with the majority of cells partially inhibited by PMA. Our results demonstrate that an alteration in a single amino acid residue in the beta-subunit of the ASSC can lead to a total loss of inhibition to PMA, and establish the beta-subunit as having an important role in conferring a regulatory effect on the ASSC of lymphocytes.

Amiloride↗
PubMed1997

Xwnt-8 and lithium can act upon either dorsal mesodermal or neurectodermal cells to cause a loss of forebrain in Xenopus embryos.

When Xenopus gastrulae are made to misexpress Xwnt-8, or are exposed to lithium ions, they develop with a loss of anterior structures. In the current study, we have characterized the neural defects produced by either Xwnt-8 or lithium and have examined potential cellular mechanisms underlying this anterior truncation. We find that the primary defect in embryos exposed to lithium at successively earlier stages during gastrulation is a progressive rostral to caudal deletion of the forebrain, while hindbrain and spinal regions of the CNS remain intact. Misexpression of Xwnt-8 during gastrulation produces an identical loss of forebrain. Our results demonstrate that lithium and Wnts can act upon either prospective neural ectodermal cells, or upon dorsal mesodermal cells, to cause a loss of anterior pattern. Specifically, ectodermal cells isolated from lithium- or Wnt-exposed embryos are unable to form anterior neural tissue in response to inductive signals from normal dorsal mesoderm. In addition, although dorsal mesodermal cells from lithium- or Wnt-exposed embryos are specified properly, and produce normal levels of the anterior neural inducing molecules noggin and chordin, they show a greatly reduced capacity to induce anterior neural tissue in conjugated ectoderm. Taken together, our results are consistent with a model in which Wnt- or lithium-mediated signals can induce either mesodermal or ectodermal cells to produce a dominant posteriorizing morphogen which respecifies anterior neural tissue as posterior.

Animals↗
PubMed1997

Focal segmental glomerulosclerosis in primates infected with a simian immunodeficiency virus.

Focal and segmental glomerulosclerosis (FSG) with endothelial tubuloreticular inclusions (TRIs) is the typical lesion of human HIV-associated glomerulopathy. Autopsy studies showed the presence of FSG in 3 of 15 macaques dying 15-120 weeks after experimental infection with a simian immunodeficiency virus (SIVMne). Ultrastructural studies generally revealed numerous endothelial TRIs (also present in normals), mesangial expansion, and evidence of mesangial cell injury. One additional animal had a small-vessel polyarteritis with a proliferative and focally crescentic glomerulonephritis; seven animals had mild, multifocal interstitial nephritis. All animals had documented viremia after infection; 14 of 15 developed antibodies to SIV postinoculation. Additional postmortem findings included severe enterocolitis, encephalitis, and opportunistic infections. In contrast, autopsy studies of macaques infected with a type D simian retrovirus (SAIDS-D/Washington, SRV-2) for similar periods of time (n = 40) showed no evidence of FSG. One SRV-infected animal had a mild proliferative glomerulonephritis. These studies indicate SIV-infected primates may provide a relevant model for study of human HIV-associated nephropathy. They also indicate the variable pathology that can be seen in primate infections of distinct retrovirus types, each of which produces a simian immunodeficiency state that resembles human AIDS.

AIDS-Associated Nephropathy↗
PubMed1997

Autoradiographic determination of changes in opioid receptor binding in the limbic system of the Columbian ground squirrel at different hibernation states.

To localize and quantify the state-dependent changes in various opioid receptor subtypes in the limbic system of non-hibernating and hibernating Columbian ground squirrels, quantitative receptor-binding autoradiography was used. Compared to the non-hibernating animals, the binding density of [3H]-[D-Pen2,5]-enkephalin (DPDPE) to the delta receptor in the lateral septum, CA3, and the hippocampal fissure of the hippocampal formation was significantly decreased in the hibernating ground squirrels. A significant reduction in the binding density of [3H]-[D-Ala2,N-Me-Phe4,Gly-ol5]-enkephalin (DAGO) to mu receptor was also observed in the medial septum and the CA3 region of the hippocampus of the hibernating animals. In contrast, a decrease in [3H]ethylketocyclazocine (EKC) binding to the kappa receptor was only observed in the claustrum and CA3 of the hippocampus during hibernation. The differential changes in binding to various opioid receptors suggest that different opioid subtypes may exert different physiological roles in regulating the specific states (entrance, maintenance and arousal) of a hibernation bout.

Animals↗
PubMed1997

Distribution of cholesterol sulfate and its anabolic and catabolic enzymes in various rabbit tissues.

Cholesterol sulfate (CS) recently has been shown to be involved in signal transduction pathway. To evaluate its functional significance, we determined the concentration of CS, and the specific activities of cholesterol sulfotransferase and CS sulfatase in various tissues of rabbit, and compared them with the concentration of sulfoglycolipids in rabbit tissues. CS was present in the epithelia and mucosa, but not in the tunica muscularis, of the digestive tract, trachea, uterine endometrium and uterine cervix. It was also present in lung, spleen, kidney, prostate, skin, hair, and nail at relatively high concentrations. Its concentration in the uterine endometrium was nine times higher in pseudopregnant rabbits than in nonpregnant rabbits because of activation of cholesterol sulfotransferase and inhibition of CS sulfatase in the pseudopregnant rabbits. Sulfoglycolipids were not detected in the uterine endometria of either non-pregnant- or pseudopregnant rabbits. However, sulfoglycolipids were detected at relatively high concentrations in the cerebrum, cerebellum, stomach, duodenum, jejunum, testis, and kidney of rabbits and thus the tissues in which both sulfolipids were detected were the gastrointestinal tract and kidney. In the digestive tract, the concentration of CS decreased in the order esophagus, stomach, duodenum, and jejunum, but that of sulfatide increased in the same order, indicating distribution of CS in the squamous epithelium. In addition, both CS and sulfatide were detected in the serum. On the other hand, CS sulfatase activity was detected in all tissues examined, even in hair, from which the enzyme was liberated by brief sonication, and its highest specific activity was detected in the liver. The specific activity of cholesterol sulfotransferase varied among the tissues examined and was found to be significantly high in the esophageal epithelium and the uterine endometrium of pseudopregnant rabbit, indicating involvement of cholesterol sulfation in the formation of epithelium.

Animals↗
PubMed1997

Acute myelogenous leukaemia with t(8;21) translocation of normal cell origin in mosaic Down's syndrome with isochromosome 21q.

We report a 13-year-old girl with Down's syndrome (DS) having a mosaic karyotype of 46,XX/46,XX, -21,+i(21q), who developed acute myelogenous leukaemia (AML) (FAB M1). The t(8;21) translocation generating a AML1/MTG8 chimaeric gene of her blasts was demonstrated by cytogenetic analysis and reverse transcription-polymerase chain reaction. Interestingly, the leukaemic clone with t(8;21) did not have isochromosome 21q, indicating that the blasts were of normal cell origin. These findings suggest that, in older patients with DS, 21 trisomy cells have no greater predisposition to develop AML than normal karyotypic cells.

Adolescent↗
PubMed1997

Molecular characterization and expression of the Erwinia carotovora hrpNEcc gene, which encodes an elicitor of the hypersensitive reaction.

The nucleotide sequence of hrpNEcc DNA, cloned from Erwinia carotovora subsp. carotovora strain Ecc71, reveals a coding region of 1,068 bp which matches the size of hrpNEcc transcripts. hrpNEcc is predicted to encode a glycine-rich protein of approximately 36 kDa. Like the elicitors of the hypersensitive reaction (HR) produced by E. chrysanthemi (HarpinEch) and E. amylovora (HarpinEa), the deduced 36-kDa protein does not possess a typical signal sequence, but it contains a putative membrane-spanning domain. In Escherichia coli strains overexpressing hrpNEcc, the 36-kDa protein has been identified as the hrpNEcc product by Western blot analysis using anti-HarpinEch antibodies. The 36-kDa protein fractionated from E. coli elicits the HR in tobacco leaves. Moreover, a HrpN- and RsmA- double mutant (RsmA = regulator of secondary metabolites) does not produce this 36-kDa protein or elicit the HR, although this strain, like the RsmA- and HrpN+ bacteria, overproduces extracellular enzymes and macerates celery petioles. These observations demonstrate that hrpNEcc encodes the elicitor of the HR, designated HarpinEcc. The levels of hrpNEcc transcripts are affected in both RsmA+ and RsmA- strains by media composition and carbon sources, although the mRNA levels are substantially higher in the RsmA- strains. The expression of hrpNEcc in Ecc71 is cell density dependent and is activated by the quorum-sensing signal, N-(3-oxohexanoyl)-L-homoserine lactone (OHL). By contrast, hrpNEcc expression in an RsmA- strain is independent of cell density, and substantial expression occurs in the absence of OHL. The effects of cultural conditions and the occurrence of putative cis-acting sequences, such as consensus sigma 54 promoters and an hrp promoter upstream of the transcriptional start site, indicate that the production of HarpinEcc in wild-type RsmA+ E. carotovora subsp. carotovora is tightly regulated. These observations, taken along with the finding that the HR is caused by RsmA- mutants but not by RsmA+ strains (Cui et al., 1996, Mol. Plant-Microbe Interact. 9:565-573), strongly support the idea that the inability of the wild-type pectolytic E. carotovora subsp. carotovora to elicit the HR is due to the lack of a significant level of HarpinEcc production.

4-Butyrolactone↗