Biomedical subjects

Q Li

Publications and source records attributed to Q Li.

At least 325 records · Page 18Linked to original sources

PubMed2000

[Analysis of the long-term results of late hand function reconstruction in patients with severe electrical injury of the wrists].

OBJECTIVE: To evaluate and analyze the long-term results of all the operation mordalities practised at present of late hand function reconstruction in patients with severe electrical injury of the wrists. METHODS: Forty-seven cases with late electrical injury of the wrists were followed up and comprehensively analyzed in terms of the long-term results of morphological reconstruction and functional restoration. RESULTS: In addition to cutaneous tissue repair and functional training of the joints of the wrists, the flexor digitorum reconstruction with auto free tendon grafting gave a poor result (only 33.4% of the cases with function above medium level). In one case, the wrist function was rebuilt by compound plantaris tendon free flap with leg deep facia and posterior tibial artery, resulting in the restoration of thumb flexor function, with shorter treating time and less postoperative adhesion. Median and ulnar nerves were repaired with free auto nerve grafting with no obvious effects. Two cases were repaired by compound tissue grafting of sural nerve and deep facia carried by small saphenous veins with uncertain result. In another 3 cases, with the aid of retrograde evoked potential (REP), a proximal anastomosis of nerves was done with fairly good result. CONCLUSION: Insufficient blood supply and scar formation were the major causes of poor results of the tendon and nerve grafting. It was recommended that the graft should carry sufficient blood supply to improve the blood supply of the recipient bed in order to improve the therapeutic effects. The selection of proximal nerve segment should include the functional examination.

Adolescent↗

PubMed2000

[Umbilical cord blood stem cells transplantation from an unrelated donor into an adult with severe aplastic anemia].

OBJECTIVE: To evaluate the availability of the treatment of adult severe aplastic anemia with unrelated allo-cord blood stem cell transplantation (CBSCT). METHODS: HLA-matched unrelated cord blood transplantation has been successfully performed for an adult severe aplastic anemia patient. A unit of cord blood provided by Guangzhou Cord Blood Bank containing 1.89 x 10(7)/kg mononucleated cells, 1.8 x 10(4)/kg CFU-GM and of CD(34) positive cells was 0.009. The patient was conditioned with CTX (60 mg/kg) and anti-lymphocyte globulin (ALG, 120 mg/kg). GVHD prophylaxis consisted of both MTX and CsA. The CsA had been given for 8 months. RESULTS: The lowest ANC was 0.6 x 10(9)/L post-transplantation. The patient achieved an ANC of greater than 0.5 x 10(9)/L at 10 days, and the platelet of greater than 50.0 x 10(9)/L at day 20 after transplantation. He developed Grade 1 GVHD in the tenth month after grafting. Microsatellite DNA fingerprinting indicated a stable donor-recipient mixed chimerism, whilst the circulating red cells remained host origin. CONCLUSION: It is the first report in China on successful treatment of adult severe aplastic anemia by unrelated allo-CBSCT.

Adult↗

PubMed2000

[Effects of muscle spindle afferents on the regulation of respiration in rabbit].

Effect of muscle spindle afferent invoked by intraarterial injection of succinylcholine (Sch) on respiration was assessed by changes in unit discharge of respiration related neurons and phrenic nerve of 63 anesthetized, bilaterally vagotomized and artificially ventilated rabbits. The results are as follows. (1) Intra~arterial injection of Sch prolonged inspiratory duration (Ti) or decreased expiratory duration (Te) and augmented respiratory frequency (RF). (2) 66% (37/56) of the medullary inspiratory neurons were excited and 10/17 of the expiratory neurons were inhibited by intraarterial injection of Sch, reaching maximum respectively at 1 2 and 2 3 min after injection, while non-respiration related neurons were not affected. (3) This effect of Sch was suppressed or abolished when muscle spindles were destroyed by intramuscular injection of bupivacaine.

Afferent Pathways↗

PubMed2000

GABAergic neurons in Kölliker-Fuse nucleus and Bötzinger complex with axons projecting to phrenic nucleus.

Experiments were made on 6 adult cats. Brainstem neurons that project to the phrenic nucleus were retrogradely labeled by microinjection of WGA-HRP into phrenic nucleus. The brainstem sections were doubly processed for HRP histochemical staining with the TMB-Co-DAB method, and GABA immunohistochemical staining with anti-GABA primary antibody and FITC conjugated immunofluorescent secondary antibody. HRP-FITC double-labeled neurons were observed in the pontine Kölliker-Fuse nucleus and areas around the retrofacial nucleus (Bötzinger complex). Double-labeled neurons were also observed in the raphe nucleus, the lateral paragigantocellular nucleus, and the vestibular nucleus. The results show that brainstem GABAergic neurons in these structures, especially those in the Kölliker-Fuse nucleus and the B?t.C, send axonal projections to the phrenic nucleus.

Animals↗

PubMed2000

[Studies on technology of supercritical-CO2 fluid extraction for volatile oils and saikosaponins in Bupleurum chinense DC].

OBJECTIVE: To study the technology of supercritical-CO2 fluid extraction (SFE-CO2) for the volatile oils and saikosaponins in Bupleurum chinense. METHOD: Exploring the effects of pressure, temperature, extraction time, flow rate of CO2 and entrainers on the yield of the oils and saikosaponin-contained extracts; determining the optimum conditions for SFE-CO2; analyzing the oils by GC/MS and comparing the technology of SFE-CO2 with that of traditional steam distillation. RESULT: The optimum extraction conditions turned out to be--for volatile oils: pressure (EP) = 20 MPa, temperature (ET) = 30 degrees C, isolator I pressure (1P-I) = 12 MPa, temperature(1T-I) = 65 degrees C, isolator II pressure (1P-II) = 6 MPa, temperature (1T-II) = 40 degrees C, extraction time = 4 hours, and CO2 flow rate = 10-20 kg.(h.kg)-1 crude drug; for saikosaponins: EP = 30 MPa, ET = 65 degrees C, 1P I = 12 MPa, 1T I = 55 degrees C, 1P II = 6 MPa, 1T II = 43 degrees C, extraction time = 3 hours, entrainer = 60% ethanol, and CO2 flow rate = 20-25 kg.(h.kg)-1 crude drug. CONCLUSION: SFE-CO2 excels the traditional steam distillation in raising yield and reducing extraction time. The oils are composed of 22 constituents including caproaldehyde, and the saikosaponins can only be extracted with the help of entrainers under higher pressure and temperature.

Bupleurum↗

PubMed2000

[Analysis of maxillary dental-arch dimensions in adult unoperated cleft palate patients].

OBJECTIVE: Analysis of maxillary dental-arch development in adult unoperated cleft palate patients. METHODS: Dental casts was studied in 20 cases of adult unoperated cleft palate (UCP) patients, and 20 cases of normal adults were as a control group. RESULTS: The UCP group showed smaller dental-arch widths than a control group in the canine region (P < 0.05) and these was no significant difference on upper-arch depth and posterior dental arch widths between the UCP group and a control group (P > 0.05). CONCLUSION: In the UCP group major deformity were in incisor and canine region, and smaller interfere to posterior dental-arch widths and depth. Operation for cleft lip can interfere maxillary dental-arch development.

Adolescent↗

PubMed2000

[Measuring and analyzing of otoacoustic emission tests of a family with genetic progressive sensorineural hearing loss].

OBJECTIVE: To study the diagnostic significance of otoacoustic emission in patients with genetic progressive sensorineural hearing loss. METHOD: To analyse the cochlear function pure tone audiometry Transient Evoked Otoacoustic Emission (TEOAE) and distortion Products Otoacoustic Emission (DPOAE) were measured in 54 members of a six-generation family with genetic progressive sensorineural hearing loss (108 cases) and 50 normal people. RESULT: The family was autosomal dominant heritage. In the group with pure tone thresholds more than 20 dB HL, the amplitudes of TEOAE descended or disappeared in 84% cases and the amplitudes of DPOAE declined or vanished in 82% cases. In the group with normal pure tone thresholds, the amplitudes of TEOAE descended in 75% cases and the amplitudes at one of the frequencies of DPOAE dropped or disappeared in 64% cases. But the incidence of TEOAE and DPOAE in normal people was 100%. CONCLUSION: OAE had important significance in the diagnosis of genetic hearing loss at early stage.

Adolescent↗

PubMed2000

[The identification of Bungarus multicinctus multicinctus and its confused species by SDS-PAGE].

The comparative study of the proteins of Bungarus multicinctus multicinctus and Natrix annularis was carried out by SDS-PAGE. The results showed that there were significant differences between their SDS-PAGE figures. On the basis of the study the molecular weights of their characteristic proteins were determined. The results could be regarded as a reference for identification of Bungarus multicinctus multicinctus and its confused species.

Animals↗

PubMed2000

The effects of triptolide on HLA antigens expression of corneal epithelial cells induced by interferon-gamma in vitro.

OBJECTIVE: To observe the effects of immunosuppressants triptolide (TL) and cyclosporine A (CSA) on HLA antigens expression induced by interferon-gamma(INF-gamma) in vitro. METHOD: By using an indirect immunofluorescent method and analysing with ACAS-570, the abnormal HLA antigen expression of cultured corneal epithelial cells was induced by INF-gamma. After incubation with one of the immunosuppressants (CSA, TL) for 72 hrs, the amount of HLA-A BC and HLA-DR antigens was measured. RESULT: There was no significant difference (P > 0.05) between the group with CSA and the positive control group without CSA. In contrast to CSA, TL dramatically inhibited INF-gamma induced expression of HLA antigens of corneal epithelial cells (P < 0.001), compared with the control group without TL. CONCLUSION: TL had direct inhibition on the expression of HLA-ABC and HLA-DR antigens induced by INF-gamma in vitro, while CSA had no obvious inhibition.

Cells, Cultured↗

PubMed2000

[Value of preservation of uvula in uvulopalatopharyngoplasty].

OBJECTIVE: To explore the effect of the modified Uvulopalatopharyngoplasty (UPPP) where uvula is preserved in the operation, and whether the postoperative complications are diminished. METHODS: Thirty consecutive patients with the obstructive sleep apnea syndrome (29 men, 1 woman) were analyzed by questionnaire, polysomnography and oral cavity measurement before and 6 months after uvulopalatopharyngoplasty to assess the surgical outcome and value of preservation of uvula in the operation. RESULTS: Eighty-seven percent of patients reported improvement of snoring and daytime sleepiness. Fifty-three percent of patients showed a decrease of at least 50% in the apnea and hypopnea indices. Among the mild and moderate obstructive sleep apnea (AHI < 50), 73.3% of them showed a decrease of at least 50% in the AHI. No velopalatal insufficiency occurred. The result of oral cavity measurement showed that the uvula, which was preserved completely during the operation, began to contract 2 weeks after the operation. Three to six month after operation, uvula contracted to the normal length and the anatomical shape of the pharyngeal cavity became normal. CONCLUSIONS: The results of the uvula preserving UPPP indicate that this approach not only improves the effect of the UPPP, but also avoids the postoperative complications. The uvula that preserved completely during the operation will contract to the normal length progressively.

Adult↗

PubMed2000

[Investigation of connective tissue growth factor's gene cloning].

OBJECTIVE: The human connective tissue growth factor(CTGF), as the responsive product of immediate early gene, was cloned for the investigation of cellular primary gene responded and healing repairing. METHODS: RT-PCR was performed with the mRNA of HUVE cell stimulated, the three clones of CTGF, via mutational modified, were ligated to a complete gene that identified with sequencing. RESULTS: The sequencing indicated that this CTGF gene contains complete coding region and the 3'-noncoding region which is difference with the reported sequence. CONCLUSION: A new human CTGF gene was cloned.

Base Sequence↗

PubMed2000

[Distinctive infrared spectral features in human breast cancer].

Substantial differences were found in the spectral properties of surgical samples from 20 women patients with histologically normal and cancerous breast tissue. The most striking changes in the spectra were observed in the symmetric and asymmetric stretching bands of phosphodiester groups, which shifted to short wavenumber about 3 cm-1 in nu s PO2-, and to long wavenumber about 2 cm-1 in nu s PO2-. The ratio of A1,173/A1,163 increased and that of A1,025/A1,082 decreased, the intensity of symmetric and asymmetric stretching bands of CH3 decreased and those of CH2 increased in all of breast cancer tissues. Our findings indicated that in breast cancer tissue, the degree of hydrogen-bonding of oxygen atoms in the backbone of nucleic acid increased; the content of glycogen decreased; the degree of hydrogen-bonding of OH groups in serine, tyrosine, and threonine residues of cell proteins decreased; and also there were changes in the packing and the conformational structure of the methylene chains of membrane lipids.

Breast Neoplasms↗

PubMed2000

[Experimental study on using mGTR and silicone gel tube connection to repair facial nerve defect in rabbits].

OBJECTIVE: To observe and compare the effects of using mGTR or Silicone tube to repair the defect of facial nerve. METHODS: mGTR and Silicone tube methods were performed on three groups of rabbits. Then physical and histological examination was carried out to get the results of these two repair methods. RESULTS: Both the two methods can induce regeneration of facial nerve. The mGTR was more effective and faster in repairing the nerve defect. Three months after operation, the distance of NCV between the two sides of facial nerve in mGTR group was 2.33+/-1.2 m/s, 10.21+/-1.5 m/s in Silicone tube group, and 2.16+/-1.6 m/s in autogeneous nerve transplantation group. CONCLUSION: The mGTR is more effective than Silicone tube method in repair facial nerve. mGTR has some other advantages, it is likely to be a new method of nerve repair on clinical domain.

English Abstract↗

PubMed1999

Insulin-like growth factor binding protein 2 is a growth inhibitory protein conserved in zebrafish.

Fish serum contains several specific binding proteins for insulin-like growth factors (IGFBPs). The structure and physiological function of these fish IGFBPs are unknown. Here we report the complete primary sequence of a zebrafish IGFBP deduced from cDNA clones isolated by library screening and rapid amplification of cDNA ends. The full-length 1,757-bp cDNA encodes a protein of 276 aa, which contains a putative 22-residue signal peptide and a 254-residue mature protein. The mature zebrafish IGFBP has a predicted molecular size of 28,440 Da and shows high sequence identity with human IGFBP-2 (52%). The sequence identities with other human IGFBPs are <37%. Chinese hamster ovary cells stably transfected with the zebrafish IGFBP-2 cDNA secreted a 31-kDa protein, which bound to IGF-I and IGF-II with high affinity, but did not bind to Des(1-3)IGF-I or insulin. Northern blot analyses revealed that the zebrafish IGFBP-2 transcript is a 1.8-kb band expressed in many embryonic and adult tissues. In adult zebrafish, IGFBP-2 mRNA levels were greatly reduced by growth hormone treatment but increased by prolonged fasting. When overexpressed or added to cultured zebrafish and mammalian cells, the zebrafish IGFBP-2 significantly inhibited IGF-I-stimulated cell proliferation and DNA synthesis. These results indicate that zebrafish IGFBP-2 is a negative growth regulator acting downstream in the growth hormone-IGF-I axis.

Amino Acid Sequence↗

PubMed1999

Function of the c-Myc oncogenic transcription factor.

The c-myc gene and the expression of the c-Myc protein are frequently altered in human cancers. The c-myc gene encodes the transcription factor c-Myc, which heterodimerizes with a partner protein, termed Max, to regulate gene expression. Max also heterodimerizes with the Mad family of proteins to repress transcription, antagonize c-Myc, and promote cellular differentiation. The constitutive activation of c-myc expression is key to the genesis of many cancers, and hence the understanding of c-Myc function depends on our understanding of its target genes. In this review, we attempt to place the putative target genes of c-Myc in the context of c-Myc-mediated phenotypes. From this perspective, c-Myc emerges as an oncogenic transcription factor that integrates the cell cycle machinery with cell adhesion, cellular metabolism, and the apoptotic pathways.

Basic Helix-Loop-Helix Leucine Zipper Transcriptio↗

PubMed1999

Cloning and uterus/oviduct-specific expression of a novel estrogen-regulated gene (ERG1)

The steroid hormone estrogen profoundly influences growth and differentiation programs in the reproductive tract of cycling and pregnant mamals. It is thought that estrogen exerts its cellular effects by regulating the expression of specific target genes. We utilized a messenger RNA differential display method to identify the genes whose expression is modulated by estrogen in the preimplantation rat uterus. Here we report the cloning of a novel gene (ERG1) that is tightly regulated by estrogen in two key reproductive tissues, the uterus and oviduct. Spatio-temporal analyses reveal that ERG1 mRNA is expressed in a highly stage-specific manner in the uterus and oviduct, and its expression is restricted to the surface epithelium of both of these tissues. Nucleotide sequence analysis of the full-length ERG1 cDNA indicates that it has an open reading frame of 1821 nuceotides encoding a putative protein of 607 amino acids with a single transmembrane domain and a short cytoplasmic tail. The extracellular part of the protein contains several distinct structural motifs. These include a zona pellucida binding domain, which is present in a number of proteins such as the zona pellucida sperm binding proteins, and uromodulin, In addition, there is a repeat of a motif called CUB domain, which exists in a number of genes involved in development and differentiation such as bone morphogenetic protein 1 (BMP1). Although the precise function of ERG1 eludes us presently, its unique pattern of expression in the uterus and oviduct and its regulation by estrogen, a principal reproductive hormone, lead us to speculate that this novel gene plays an important role in events during the reproductive cycle and early pregnancy.

Amino Acid Sequence↗

PubMed1999

Molecular analysis of the klarsicht gene and its role in nuclear migration within differentiating cells of the Drosophila eye.

BACKGROUND: The temporally regulated, cell-type-specific transport of organelles has great biological significance, yet little is known about the regulation of organelle transport during development. The Drosophila gene klarsicht is required for temporally regulated lipid droplet transport in developing embryos and for the stereotypical nuclear migrations in differentiating cells of the developing eye. Klarsicht is thought to coordinate the function of several molecular motors bound to a single lipid droplet or to facilitate the attachment of dynein to the cargo, but it is not known whether Klarsicht affects motors directly or indirectly. RESULTS: Here, we have cloned the klarsicht gene and shown that it encodes a unique large protein. Drosophila klarsicht null mutants were viable, with obvious defects only in adult eye morphology. Epitope-tagged Klarsicht expressed in the eye from a transgene was perinuclear. In flies carrying transgenes that express markers for microtubule plus and minus ends, microtubules in differentiating cells of the eye were oriented with their plus ends apical and their minus ends at the nucleus. CONCLUSIONS: Drosophila klarsicht null mutants were viable and fertile, demonstrating that klarsicht is essential only for specific motor protein functions. Perinuclear localization of Klarsicht protein indicates that Klarsicht has a direct mechanical role in nuclear migration. Taken together with the finding that the minus ends of the microtubules are associated with the photoreceptor nuclei, the observation that Klarsicht is largely perinuclear supports the idea that Klarsicht associates with dynein, consistent with a model in which Klarsicht assists dynein in 'reeling in' the nucleus.

Animals↗

PubMed1999

Glucocorticoid receptor expression in the spinal cord after traumatic injury in adult rats.

Methylprednisolone (MP), a glucocorticoid, is the only effective therapeutic agent used in the clinical treatment of acute spinal cord injury (SCI). MP given within 8 hr after SCI significantly improves neurological function. Although the glucocorticoid receptor (GR) is suggested to mediate MP actions, limited knowledge is available on its expression and possible function after SCI. Presently, the expression of GR was studied in a weight-drop SCI model in adult rats. Immunohistochemistry and Western blot analysis revealed an increase in GR protein expression as early as 15 min after injury. GR expression sharply increased at 4 hr (22-fold), peaked at 8 hr (56-fold), rapidly declined at 1 d, and returned to the baseline level at and after 3 d. During its peak expression, GR was localized in neural somata and dendrites but not in axons and their terminals. GR immunoreactivity was also found in oligodendrocytes and astrocytes. Interestingly, other cell types, such as endothelial cells, were GR-negative. An increase in the binding activity of nuclear proteins to the glucocorticoid responsive element was also observed after SCI, demonstrating a functional element of GR activation. Finally, colocalization of GR and tumor necrosis factor alpha (TNF-alpha), an inflammatory cytokine, was observed in neurons and glial cells, consistent with MP regulation of TNF-alpha in this model. Thus, the transient expression of high levels of GR after SCI may provide new insights into the anti-inflammatory action of MP.

Animals↗