Biomedical subjects

Bo Liu

Publications and source records attributed to Bo Liu.

At least 73 records · Page 4Linked to original sources

PubMed2006

[Auditory capability evaluation for children after cochlear implantation using meaningful auditory integration scale].

OBJECTIVE: To analyze the auditory capability of preschool children before and after cochlear implantation using meaningful auditory integration scale (MAIS) questionnaire. METHODS: Eighty-two prelingually deaf patients participated in this study. They received a cochlear implant at the age of 3 to 6 years and 11 months. The audiologists who were trained for the research used the MAIS questionnaire. Audiologists asked for the parents' answers and recorded all the information about the device using (Q1,2) and the patient's spontaneous auditory behavioural responses including spontaneous alerting to sound Q3 approximately 6 and deriving meaning from sound (Q7 approximately 10). The evaluation was performed before operation and 1 , 3, 6 months, 1, 1.5, 2 years after switch-on. RESULTS: The scores of question 1a and 1b were not significantly different among the different periods after switch-on. The scores of question 2 to 10 were significantly different among the different periods after switch-on. CONCLUSIONS: Considerable variability across subjects' auditory ability after cochlear implantation was noted. Most of the patients showed no consistent response to sound in everyday life before implantation. After cochlear implantation, a significant increase in auditory capability occurred. The children demonstrated faster development of device using relative to spontaneous alerting to sound and deriving meaning from sound.

Auditory Perception↗

PubMed2006

[Progress of the PCR amplification techniques for chromosome walking].

Various PCR-based methods are available for chromosome walking from a known sequence to an unknown region. It is promising in genome-related research for the following experiments: promoter cloning, obtaining non-conservative parts of genes in new species, identification of T-DNA or transposon insertion sites and filling in gaps or unknown chromosome regions in genome sequencing. These methods consisted of three types: inverse PCR, ligation-mediated PCR and specific primer PCR. In this review, we illustrated and compared the current techniques.

Animals↗

PubMed2006

[Cloning, expression and biochemical characterization of a novel diacetylchitobiose deacetylase from the hyperthermophilic archaeon Pyrococcus horikoshii].

Chitin is the second most abundant organic compound in nature and the degradation of this biomass is an important process in the recycling of nutrients in the environments. Several biodegradation pathway of chitin have been classified in eukaryotes and bacteria, and a unique chitin degradation pathway was proposed according to recent studies on hyperthermophilic archaeon Thermococcus kodakaraensis. In the genome of Pyrococcus horikoshii, several ORFs show high homology to the chitin-degrading related genes from T. kodakararaensis, therefore P. horikoshii is likely to have the same chitin degrading pathway as that of T. kodakaraensis. In order to further characterize the novel chitin degrading pathway in thermophilic archaea, a diacetylchitobiose deacetylase from P. horikoshii (Dacph) was studied in the present study. Dacph belongs to the LmbE-like protein family and the amino sequence is not related to the other deacetylases studied before (except that in T. kodakararaensis). The gene (Dacph, PH0499) from the hyperthermophilic archaeon P. horikoshii was amplified by polymerase chain reaction, cloned into expression vector pET15b, and expressed in E. coli BL21-codonPlus (DE3)-RIL. A soluble fraction of Dacph (31.6kDa) was obtained as shown by SDS-PAGE. TLC analysis showed that Dacph is able to deacetylate one acetyl group of GlcNAc2 and GlcNAc. By the concerted reaction with the Exo-beta-D-Glucosaminid-ase (BglAph), it is also able to convert GlcNAc2 into GlcN. It is concluded that PH0499 is a diacetylchit-obiose deacetylase. By reaction together with Exo-beta-D-Glucosaminidase in P. horikoshii, Dacph probably plays a key role in the new chitin degradation pathway in hyperthermophilic archaea (the genera Thermococcus and Pyrococcus).

Archaeal Proteins↗

PubMed2006

[Changes of immune function and nutrition state in pelagic fishermen].

OBJECTIVE: To investigate the effects of long time cruising on fishermen' immune function and nutrition state. METHODS: Thirty-two fishermen's lymphocyte subsets, immunoglobulin, alexin, prealbumin, albumin, blood fat, hemoglobin serum iron, transferrin were tested before and after cruising. RESULTS: The expression of CD-19 was significantly higher after cruising (P < 0.001) while other cell immune functions were not significantly changed. After cruising, the immunoglobulin IgG, IgA, alexin C3, B, prealbumin, albumin, transferrin were higher than before cruising (P < 0.001). HDL-C was higher (P < 0.05); Apo-B, and serum iron were lower (P < 0.01). CONCLUSION: The cruising fishermen' immune function is changed significantly; the nutrition state is good, but the serum iron is insufficient and in subclinical state.

Adult↗

PubMed2006

[Optimized culture medium and fermentation conditions for lipid production by Rhodosporidium toruloides].

Culture medium and fermentation conditions for lipid production by Rhodosporidium toruloides were optimized with single factor and uniform design experiment. The best medium recipe was found with 70 g/L glucose, 0.1 g/L (NH4)2SO4, 0.75 g/L yeast extract, 1.5 g/L MgSO4. 7H2O, 0.4g/L KH2PO4, sterilized at 121 degrees C for 15 min, and then supplemented with ZnSO4 1.91 x 10(-6) mmol/L, CaCl2 1.50 mmol/L, MnCl2 1.22 x 10(-4) mmol/L and CuSO4 1.00 x 10(-4) mmol/L. The optimal fermentation conditions were as follows: 50 mL of medium (pH 6.0) in 250 mL Erlenmeyer flask with 10% inoculum (28h) under orbital shaking at 200 r/min for 120h at 30 degrees C. Under these conditions, yeast biomass accumulated lipids up to 76.1%.

Basidiomycota↗

PubMed2006

[Experimental study on the effect of tiangui gengnian capsule on the aged female rats ostepoprosis].

OBJECTIVE: To study the therapeutic action of Seabuckthorn Fatty Acid on the aged female rats osteoporosis, and explore the corresponding mechanism related in hormone and cytokine. METHODS: The change of bone density (BMD), biomechanics and bone morphology were measured and E2, TGF-beta1, IGF-1 level in plasma were determined respectively for the young female rats, aged female rats (Seabuckthorn Fatty Acid 0.72, 1.8, 4.5 g/kg, E2 0.02 g/kg) after they were administrated corresponding drugs for 45 days. RESULTS: The bone density (BMD), bone biomechanics, bone morphology for female rats aged 22-months all decreased. The BMD, bone biomechanics, the number of bone trabeculas and cortical thickness in Seabuckthorn Fatty Acid treated groups (1.8 g/kg, 4.5 g/kg) were upgraded (P < 0.05). The TGF-beta1, IGF-1 level in plasma were increased, too (P < 0.05). CONCLUSION: Seabuckthorn Fatty Acid can meliorate bone metabolism in post-menopause and heighten the bone density. The adjustment mechanism may be based on the function of estrogen and cell cytokine.

Animals↗

PubMed2006

[Effects on biomechanical properties of hip articular cartilage degeneration following the femoral neck fracture in rabbits].

Osteotomies were performed through post-lateral approach under the base of femoral neck on 60 New Zealand white rabbits. The changes of the thickness and biomechanical properties of acetabular cartilage following the cartilage degeneration and the relationship to the postoperative time 2, 4, 6, 8, 12, 16 weeks later were measured respectively. The cartilage specimens were harvested and measured by the automated creep indentation apparatus to obtain the thickness and biomechanical properties. The cartilage became thicker within 6 weeks after operation, cartilage degeneration developed critically from the surface with the lost of the biomechanical properties. The degeneration progressed till the eartilage became thinner and thinner and the to be torn out into pieces at last. The matrix of articular cartilage degraded markedly for the absence of normal stress load following the femoral neck fracture, led to the decline of the biomechanical properties and kept the degeneration progress to osteoarthritis.

Animals↗

PubMed2006

[Establishment of model with inner ear mimetic aging and mtDNA 4834 bp deletion in rats].

OBJECTIVE: To explore the establishment of the mimetic aging effect in the inner ear of the rat. METHOD: Twenty-four Wistar rats were randomly divided into two groups: group A (D-galactose group, n = 14), which were treated with hypodermic 5% D-galactose (150 mg x kg(-1) x d(-1)) for 8 weeks and then with intraperitoneal saline for 10 days, and group B (control group, n = 10), which were given saline only. Auditory brainstem response(ABR) was used to detect the hearing threshold of rats, and colorimetry was used to analyze the activity of the glutathione peroxidase (GSH-PX). The inner ear tissue was harvested and mitochondrial DNA was amplified to identify the 4 834 bp deletion mutation by nested primer polymerase chain reaction (nested PCR) technique. RESULT: The incidence of mitochondrial DNA 4 834 bp deletion of group A was 100% (28/28), while the deletion of group B was 0. The activity of the GSH-PX in group A (59.07 +/- 8.70 U) was lower than that in group B (142.10 +/- 7.02 U). The difference between group A and group B was significant (t-test, P < 0.01). Variation in ABR threshold of (5.36 +/- 3.08) dB peSPL was observed in group A, and (6.50 +/- 3.37) dB peSPL in group B. The difference in shift of ABR threshold between group A and group B was not significant (P > 0.05). CONCLUSION: The mimetic aging effect in the inner ear of the rat can be induced by D-galactose, and this rat model presents high incidence of mtDNA4834 deletion. But no hearing loss was found in this model.

Aging, Premature↗

PubMed2006

[Effects of cropping system and cultivation pattern on bacterial populations and anti-fusarium wilt bacteria in melon soils].

A total of 132 soil samples were collected from Xinjiang, Fujian and Zhejiang provinces to study the effects of different cropping system and cultivation pattern on the amount of bacterial populations and the distribution of anti-fusarium wilt bacteria in melon soils. The results of plate counting showed that the amount of culturable bacteria was 15.2 times higher in melon soils than in uncultivated soil, 1.0 times higher in rhizosphere than in non-rhizosphere, 2.5 times higher in the soil with rotation than in that with monoculture, and 0.5 times higher in the soil with non-graft than in that with graft. The Biolog determination of anti-fusarium wilt bacteria in melon soils showed that the soil with water-drought rotation or graft had more antagonistic bacteria, and more than 80% of them were classified as fluorescent Pseudomonas spp.

Antifungal Agents↗

PubMed2005

[Preoperative diagnosis and microsurgery of the optic gliomas:retrospective analysis of 7 patients].

OBJECTIVE: To summarize the clinical characteristics and therapeutic experience of optic gliomas. METHODS: The clinical data of 7 patients of our department in the past 3 years were analyzed. RESULTS: In this series of optic glioma patients, the average age was 18.7 years, the ratio of men to women was 4:3, and 100% of the tumors were sub-totally removed. Diabetes inspidus was the most comman postoperative complication. CONCLUSION: The optic glioma is benign intracranial tumor with good prognosis. The key point of treatment is surgical resection combined with proper postoperative radiotherapy.

Adolescent↗

PubMed2005

Spectral signatures and structural motifs in isolated and hydrated monosaccharides: phenyl alpha- and beta-l-fucopyranoside.

The conformation and structure of phenyl-alpha-l-fucopyranoside (alpha-PhFuc), phenyl-beta-L-fucopyranoside (beta-PhFuc) and their singly hydrated complexes (alpha,beta-PhFuc.H(2)O) isolated in a molecular beam, have been investigated by means of resonant two photon ionization (R2PI) spectroscopy and ultraviolet and infrared ion-dip spectroscopy. Conformational and structural assignments have been based on comparisons between their experimental and computed near IR spectra, calculated using density functional theory (DFT) and their relative energies, determined from ab initio (MP2) calculations. The near IR spectra of "free" and hydrated alpha- and beta-PhFuc, and many other mono- and di-saccharides, provide extremely sensitive probes of hydrogen-bonded interactions which can be finely tuned by small (or large) changes in the molecular conformation. They provide characteristic "signatures" which reflect anomeric, or axial vs. equatorial differences, both revealed through comparisons between alpha/beta-PhFuc and alpha/beta-PhXyl; or similarities, revealed through comparisons between fucose (6-deoxy galactose) and galactose; or binding motifs, for example, "insertion" vs. "addition" structures in hydrated complexes. At the monosaccharide level (the first step in the carbohydrate hierarchy), these trends appear to be general. In contrast to the monohydrates of galactose (beta-PhGal) and glucose (beta-PhGlc), the conformations of alpha- and beta-PhFuc are unaffected by the binding of a single water molecule though changes in the R2PI spectra of multiply hydrated alpha-PhFucW(n) however, may reflect a conformational transformation when n> or = 3.

Carbohydrate Conformation↗

PubMed2005

[Accuracy of CT-based navigation of pedicle screws implantation in the cervical spine compared with X-ray fluoroscopy technique].

OBJECTIVE: To evaluate the feasibility and accuracy of cervical spine pedicle screw fixation assisted by X-ray fluoroscopy and CT-based navigation system. METHODS: 145 cervical pedicle screws were placed assisted by X-ray fluoroscopy and 159 cervical pedicle screws were placed assisted by CT-based navigation system. Screw positions were evaluated by postoperative CT scans or C-arm X-ray 3 dimensional reconstruction. RESULTS: In the computer- assisted group, 155 (97.5%) screws were found completely within their pedicles compared with 133 (91.7%) correctly placed screws in the X-ray assisted group (P < 0.05). The process of navigation investigated in twenty patients showed that the mean time for registration and surface matching was 3.5 (range from 2 to 8 minutes) minutes and the mean time for screw-marker insertion was 2 (range from 1 to 3.5 minutes) minutes with the mean position deviation 0.31 mm (0.12-0.56 mm) per screw. Only twice C-arm fluoroscopy were performed to verify the accuracy of one screw position intraoperatively. No severe complications like neurovascular lesion occurred in both groups. CONCLUSION: CT-based navigation system can increase the accuracy of cervical pedicle screw implantation significantly.

Adult↗

PubMed2005

Multiply-charged negative clusters of adenosine-5'-monophosphate in the gas phase.

Multiply-charged noncovalent cluster anions of adenosine-5'-monophosphate (AMP) were formed by electrospray ionization (ESI). Ions in higher charge states were observed when the ions were accumulated in an ion trap with helium buffer gas before detection. We determined the smallest size (n(a)) or appearance size as a function of charge state (q), i.e., n(a) = 4 for q = 2, n(a) = 8 for q = 3, and n(a) = 13 for q = 4. The relation between n(a) and q can be described by a charged droplet model. When the size is larger than n(a) for a given q, the fragmentation pathway of an anion cluster is dominated by loss of neutral fragments. In contrast, when the size approaches the appearance size, only charged fragments are formed.

Adenosine Monophosphate↗

PubMed2005

Simple reporter gene-based assays for hairpin poly(amide) conjugate permeability and DNA-binding activity in living cells.

Hairpin poly(amide)s (HPs) are sequence specific DNA-binding compounds that have engendered considerable interest as potential pharmacological agents to manipulate the expression of specific genes. However, recent reports have indicated that the ability of HP conjugates to pass through cell membranes is sensitive to the cell type employed and the nature of the conjugate. Furthermore, while binding of HPs to DNA sequences in vitro is relatively well understood, packing of DNA into chromatin in living cells makes predicting the efficiency with which a given poly(amide) will bind its cognate site less certain. Previous methods to evaluate HP permeability and binding in vivo, while effective, are somewhat tedious and qualitative. We report here two related reporter gene-based assays that provide a more convenient and quantitative measure of poly(amide) permeability and DNA binding activity in living cells. We anticipate that these methods will complement existing tools and facilitate the development of HP conjugates with the desired biological activity.

Base Sequence↗

PubMed2005

Protein kinase C delta induces apoptosis of vascular smooth muscle cells through induction of the tumor suppressor p53 by both p38-dependent and p38-independent mechanisms.

Apoptotic death of vascular smooth muscle cells (SMCs) is a prominent feature of blood vessel remodeling. In the present study, we examined the novel PKC isoform protein kinase C delta (PKCdelta) and its role in vascular SMC apoptosis. In A10 SMCs, overexpression of PKCdelta was sufficient to induce apoptosis, whereas inhibition of PKCdelta diminished H2O2-induced apoptosis. Moreover, evidence is provided that the tumor suppressor p53 is an essential mediator of PKCdelta-induced apoptosis in SMCs. Activation of PKCdelta led to accumulation as well as phosphorylation of p53 in SMCs; this induction correlated with apoptosis. Furthermore, blocking p53 induction with small interference RNA or targeted gene deletion prevented PKCdelta-induced apoptosis, whereas restoring p53 expression rescued the ability of PKCdelta to induce apoptosis in p53 null SMCs. We also establish that PKCdelta regulates p53 at both transcriptional and post-translational levels. Specifically, the transcriptional regulation required p38 MAPK, whereas the post-translational modification, at least for serine 46, did not involve MAPK. Additionally, PKCdelta, p38 MAPK, and p53 co-associate in cells under conditions favoring apoptosis. Together, our data suggest that SMC apoptosis proceeds through a pathway that involves PKCdelta, the intermediary p38 MAPK, and the downstream target tumor suppressor p53.

Adenoviridae↗

PubMed2005

Observer-based online compensation of inner filter effect in monitoring fluorescence of GFP-expressing plant cell cultures.

The green fluorescent protein (GFP) isolated from the jellyfish Aequorea victoria is a very useful reporter for real-time bioprocess sensing. GFP culture fluorescence is a composite signal that can be influenced by factors such as culture autofluorescence, inner filter effect (IFE), and photobleaching. These factors complicate accurate estimation of GFP concentrations from the culture fluorescence. IFE is especially problematic when using GFP in monitoring transgenic plant cell suspension cultures, due to the aggregated nature of the cells and the high biomass concentration in these culture systems. Reported approaches for online compensation of IFE in monitoring culture NADH fluorescence or bioluminescence require online measurement of biomass density or culture turbidity/optical density, in addition to fluorescence/bioluminescence measurement. In this study, culture GFP fluorescence was used successfully to estimate GFP concentration and other important states in bioreactor culture of transgenic tobacco cells, while the influences of IFE and culture autofluorescence were rectified without the need for an additional biomass sensor. This was achieved by setting up a novel model-based state observer. First, we developed an improved model for a backscatter fluorescence probe that takes into account the influence of IFE and autofluorescence on reporting culture GFP concentration from online fluorescence. The state observer was then established using the extended Kalman filter (EKF), based on the fluorescence probe model, a dynamic state model of the plant cell bioreactor, and online GFP fluorescence measurement. Several versions of the observer were introduced to address practical requirements associated with monitoring GFP fluorescence of plant cell cultures. The proposed approach offers an effective means for online compensation of IFE to enable quantitative interpretation of the culture fluorescence signals for accurate reporting of GFP or GFP-fusion protein expression.

Algorithms↗

PubMed2005

[Human adipose derived stem cells suppress lymphocyte proliferation induced by cellular or nonspecific mitogenic stimuli].

OBJECTIVE: To study immunological properties of adipose derived stem cells (ADSC) and their in vitro immunomodulatory effects on lymphocytes. METHODS: ADSC was isolated from fat tissue by liposuction and culture expanded. Cells at passage 2 were observed for the expression of HLAI, HLAII by FACs analysis. Peripheral blood lymphocytes (PBL) were cultured with allogeneic ADSCs at dose of 1 x 10(5). A third-party ADSCs at dose of 1 x 10(2), 1 x 10(3), 1 x 10(4), 1 x 10(5) were added to the ongoing two-way mixed lymphocyte reactions (MLR) for 6 days. Value of CPM (count per minute) was calculated with luminescence counter. RESULTS: Flow cytometry showed that undifferentiated ADSCs express HLA class I but not class II. Addition of interferon gamma (IFN-gamma) for 48 hours induced greater than 90% of cells to express HLA class II. No lymphocyte response was induced by allogeneic ADSCs as stimulators. Results were similar using ADSCs pretreated with IFN-gamma. ADSCs elicited inhibit function of mixed lymphocyte cultures in a dose dependent way. Even if ADSCs were pretreated with IFN-gamma, the suppression ability was maintained. CONCLUSION: Undifferentiated ADSCs do not elicit alloreactive lymphocyte proliferative responses and could modulate immune responses in vitro.

Adipocytes↗

PubMed2005

[Relationship between LAPTM4B gene polymorphism and susceptibility of lung cancer].

OBJECTIVE: To investigate the possible association between the allelic variation of LAPTM4B and the genetic susceptibility of lung cancer. METHODS: The genotype of LAPTM4B was analyzed in 134 unrelated healthy adult individuals and 166 patients with lung cancer by utilizing polymerase chain reaction based on special primers. The genotypical distribution of LAPTM4B was analyzed by chi2 test. RESULTS: The allelic frequencies of the *2 were 40.1% and 28.0% in the lung cancer group and the healthy control group respectively, which was significantly different between the two groups (P=0.002). There was a significant difference in the overall genotypical distribution between the patients and the controls (P=0.005). The risk of suffering from lung cancer was increased 1.91 times in the individuals of the *1/2 genotype (95%CI: 1.178-3.110) and 3.26 times in the individuals of the *2/2 genotype of LAPTM4B (95%CI: 1.338-7.929) compared with the *1/2 genotype. No association was observed between the genotypical distribution of LAPTM4B and the clinical information on patients of lung cancer such as gender, age, pathological type, differentiation classification of TNM and infection of HBV. CONCLUSION: This study suggests that the allele *2 of LAPTM4B might be the risk factor of lung cancer, which could be associated with genetic susceptibility of lung cancer.

Adenocarcinoma↗