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Biomedical subjects

Q Hu

Publications and source records attributed to Q Hu.

At least 73 records · Page 4Linked to original sources
PubMed2000

Removal of nitrate from groundwater by cyanobacteria: quantitative assessment of factors influencing nitrate uptake.

The feasibility of biologically removing nitrate from groundwater was tested by using cyanobacterial cultures in batch mode under laboratory conditions. Results demonstrated that nitrate-contaminated groundwater, when supplemented with phosphate and some trace elements, can be used as growth medium supporting vigorous growth of several strains of cyanobacteria. As cyanobacteria grew, nitrate was removed from the water. Of three species tested, Synechococcus sp. strain PCC 7942 displayed the highest nitrate uptake rate, but all species showed rapid removal of nitrate from groundwater. The nitrate uptake rate increased proportionally with increasing light intensity up to 100 micromol of photons m(-2) s(-1), which parallels photosynthetic activity. The nitrate uptake rate was affected by inoculum size (i.e., cell density), fixed-nitrogen level in the cells in the inoculum, and aeration rate, with vigorously aerated, nitrate-sufficient cells in mid-logarithmic phase having the highest long-term nitrate uptake rate. Average nitrate uptake rates up to 0.05 mM NO(3-) h(-1) could be achieved at a culture optical density at 730 nm of 0.5 to 1. 0 over a 2-day culture period. This result compares favorably with those reported for nitrate removal by other cyanobacteria and algae, and therefore effective nitrate removal from groundwater using this organism could be anticipated on large-scale operations.

Biomass↗
PubMed2000

[Posttransplantation diabetes mellitus].

OBJECTIVE: To study the clinical rules of posttransplantation diabetes mellitus (PTDM). METHODS: 21 patients treated from Dec. 1992 to Sept. 1998 were analysed. RESULTS: The morbidity of PTDM was 16.3% of total patients in the corresponding period. Between the groups of PTDM and NON-PTDM, there was statistical significance in age, kidney function and family diabetic history. It was not related to CSA bottom concentration and acute rejection. In this group 2 cases were complicated by hyperosmolar nonketotic diabetic comas (9.5%) and 11 various infections (52.4%). CONCLUSIONS: PTDM as a secondary diabetes due to antirejection drugs and allograft kidney function may cause serious consequences if it is treated improperly.

Adult↗
PubMed2000

[Effects of culture conditions on callus growth and taxol formation of Taxus yunnanensis Cheng et L.K.Fu].

OBJECTIVE: To seek culture conditions suitable for the callus growth and taxol formation of Taxus yunnanensis. METHOD: Determining the growth index and taxol content in the callus cultured under different illumination conditions or on different media. RESULTS AND CONCLUSION: Darkness, the combination of 0.1 mg.L-1BAP and 2,4-D 1.0 mg.L-1, and B5, DCR or 6,7-V basal medium were favorable for the callus growth and taxol formation of Taxus yunnanensis; high NO3- concentration in the medium promoted callus growth, and high NH4+ concentration greatly inhibited callus growth, but dramatically increased taxol content.

Culture Media↗
PubMed2000

[Studies on single cell cloning of Ginkgo biloba L].

OBJECTIVE: To investigate the relations of the productivity stability of to the homogenization of Ginkgo biloba cells by single cell clones. METHOD: Using plant single cell plate culture technique. RESULTS: Adding 500 ml.L-1L-glutamine in the medium increased greatly the cell plating efficiency (PE), and within the range 0.5-5.0 x 10(4) Cell.ml-1 of the initial cell density, the PE increased with the increment of the cell density. Of the 48 cell clones obtained, the GKB content in G-22 clone reached 0.099%; and most of the clones remain stable in growth and GKB production during subcultures. CONCLUSION: During the cell and tissue culture of G. biloba, the application of plant single cell cloning technique helps to a certain extent solve the problem of productivity instability of ginkgolide.

Cell Line↗
PubMed2000

[Animal experimental study on endocrine factors affecting alveolar repair].

OBJECTIVE: To investigate the endocrine effects on activities of alkaline phosphatase (ALP) and acid phosphatase (ACP) and to obtain the mechanism of the resorption and regeneration of the alveolar bone. METHODS: 24 dog models with two-side osseous infrabony pocket were divided into 4 groups randomly and were studied by histologic examination, enzyme cytochemistry and image analysis system. RESULTS: The activities of ALP and ACP, except ACP in the sixth month significantly decreased in the group of thyroidism comparing with that of the control group (P < 0.01), but only the activities of ALP significantly decreased in groups of ovariectomy and diabetes (P < 0.05, P < 0.01), and there was close relationship between enzyme activities and histopathologic variations. CONCLUSION: Alveolar bone repair was regulated by systemic endocrine factors and was associated with the activities of ALP and ACP osteoblasts of and osteoclasts.

Acid Phosphatase↗
PubMed2000

[The contrast study of preoperative flash visual evoked potential test and the postoperative resumed visual acuity in senile cataract patients].

PURPOSE: To study the using value of flash visual evoked potentials (FVEP) in predicting the resumed visual acuities in senile cataract patients. METHODS: Forty-three eyes with senile cataract had been conducted extracapsular cataract extraction combined with posterior chamber intraocular lens implantation. The contrast study had been carried out in this research between preoperative FVEP, light projection and color discrimination tests with the postoperative regained visual acuities. RESULTS: There were significant correlations between the regained visual acuities and the amplitudes of FVEP (X1), the latencies of P1 wave (X2) as well as color discriminations (P < 0.01). The coefficients were 0.7277, -0.5678 and 0.4302 in sequence. There was no correlation between the resumed visual acuities and the light projection test before operation. The formula of linear regression between the visual acuities (Y) and the indexes of FVEP was Y = 0.2255 +0.047X1 -0.0026X2. CONCLUSION: FVEP is an effective method to evaluate the visual function before the cataract operation. It may predict the resumed visual acuity.

Aged↗
PubMed1999

Alternatively spliced isoforms of FE65 serve as neuron-specific and non-neuronal markers.

FE65 is predominantly expressed in brain and is especially rich in the regions with the highest densities of neurons. The FE65 protein binds to an intracellular domain of the beta-amyloid precursor protein (betaPP) and may modulate the production of beta-amyloid peptide (AP). One of FE65 exons, a mini-exon (exon 9, 6 bp), is alternatively spliced, giving rise to two isoforms varying only in 6 base pairs. We quantitated the two isoforms by a sensitive reverse transcription-competitive polymerase chain reaction technique, and characterized their expressions in various tissues and cell cultures, and the kinetics of expression of the two isoforms in P19 embryonal carcinoma cell lines during neuronal differentiation. Our results show that the exon 9-inclusive (E9) form, the more abundant form in brain, was exclusively expressed in neurons, while the exon 9-exclusive (DeltaE9) form was widely expressed in all non-neuronal cells, but was not expressed in differentiated neurons. When P19 cells were differentiated to neurons, expression of FE65 was significantly up regulated ( approximately 30-fold) and the splicing pattern of the FE65 pre-mRNA was switched from the DeltaE9 pattern to the E9 form. Based upon their distinctive expression patterns, these two isoforms may serve as neuronal and non-neuronal markers, and determination of their ratios may have applications in neuropathological diagnosis.

Aged↗
PubMed1999

[Ca(2+)](i) oscillation frequency regulates agonist-stimulated NF-kappaB transcriptional activity.

In nonexcitable cells, stimulation by high agonist concentrations typically produces a biphasic increase in cytosolic Ca(2+) ([Ca(2+)](i)). This response is characterized by a transient initial increase because of intracellular Ca(2+) release followed by a sustained elevation which varies in amplitude depending on the nature of the stimulus. In contrast, low-level stimulation often evokes oscillatory changes in [Ca(2+)](i). The specific information provided by repetitive [Ca(2+)](i) spikes appears to be encoded in the frequency rather than in the amplitude of [Ca(2+)](i) oscillations. The specific, membrane-permeable inositol 1,4, 5-trisphosphate (Ins-1,4,5-P(3)) receptor blocker Xestospongin C (XeC, 2-20 microM) was used to affect [Ca(2+)](i) signaling in human aortic endothelial cells (HAEC) during an established response to low-level (1 microM) histamine stimulation. XeC produced a dose-dependent decrease in the frequency of [Ca(2+)](i) oscillations during histamine stimulation without affecting oscillation amplitude. Histamine stimulated a 14-fold increase in NF-kappaB-chloramphenicol acetyltransferase reporter gene activity that was dose-dependently decreased by XeC. Thus, during low-level agonist stimulation, [Ca(2+)](i) oscillation frequency regulates nuclear transcription in HAEC.

Aorta↗
PubMed1999

Molecular structure, localization and function of biliproteins in the chlorophyll a/d containing oxygenic photosynthetic prokaryote Acaryochloris marina.

We investigated the localization, structure and function of the biliproteins of the oxygenic photosynthetic prokaryote Acaryochloris marina, the sole organism known to date that contains chlorophyll d as the predominant photosynthetic pigment. The biliproteins were isolated by means of sucrose gradient centrifugation, ion exchange and gel filtration chromatography. Up to six biliprotein subunits in a molecular mass range of 15.5-18.4 kDa were found that cross-reacted with antibodies raised against phycocyanin or allophycocyanin from a red alga. N-Terminal sequences of the alpha- and beta-subunits of phycocyanin showed high homogeneity to those of cyanobacteria and red algae, but not to those of cryptomonads. As shown by electron microscopy, the native biliprotein aggregates are organized as rod-shaped structures and located on the cytoplasmic side of the thylakoid membranes predominantly in unstacked thylakoid regions. Biochemical and spectroscopic analysis revealed that they consist of four hexameric units, some of which are composed of phycocyanin alone, others of phycocyanin together with allophycocyanin. Spectroscopic analysis of isolated photosynthetic reaction center complexes demonstrated that the biliproteins are physically attached to the photosystem II complexes, transferring light energy to the photosystem II reaction center chlorophyll d with high efficiency.

Amino Acid Sequence↗
PubMed1999

[Construction and characterization of non-replicating recombinant vaccinia virus expressing rabies glycoprotein].

OBJECTIVE: To improve the safety of recombinant vaccinia rabies virus, the non-replicating recombinant vaccinia rabies virus VTKRG delta CK was constructed. METHODS: The rabies glycoprotein(RG) gene was introduced into the TK locus of Chinese Tiantan strain of vaccinia virus (VTKRG), and a fragment between fragment C and fragment K involving vaccinia virus virulence and host-range related genes were deleted by homologous recombinant. RESULTS: The ability to replicate in primary chick chick embryo fibroblast(CEF) and dramatically reduced replicating capability in mammalian cells of the virus were observed, whereas VTKRG delta CK could express high level of RG efficiently. The expression of RG could be detected in CEF by indirect immunofluorescence assay and Western blot analysis. The VTKRG delta CK could elicit neutralizing antibody against CVS rabies virus and protect the animals from lethal rabies virus challenge in inoculated mice. CONCLUSION: VTKRG delta CK possesses immunogenicity and higher safety.

Antigens, Viral↗
PubMed1999

[Test for the performance of BL3 safety laboratory in prevention the diffusion of aerosol].

The performance of BL3 safety laboratory in preventing experimental aerosol diffusion and sterilizing microbe aerosols through high efficiency filter in a ventilation system was tasted. Aerosols of uranin, vibrio phage and Bacillus subtilis var. niger spores were used for the test. The results showed that the safety cabinets and the negative pressure room in the BL3 safety laboratory were effective. The sterilization efficiency by the combination of ozone, ultraviolet and high efficiency filter in a ventilation system of the laboratory was satisfactory. However, the position of fan and the leakage of ventilation ducts must be improved.

Aerosols↗
PubMed1999

The expression of GABA(A) receptor alpha2 subunit is upregulated by testosterone in rat cerebral cortex.

The GABAergic system is sexually dimorphic in certain brain regions and can be regulated by testosterone (T). However, the contribution of T to sex-specific developmental processes in the brain is less clear. We have examined whether T regulates expression of GABA(A) receptor alpha2 subunit in the cerebral cortex of embryonic and postnatal female rats using in situ hybridization and Western blotting. We found that both alpha2 mRNA and protein levels are significantly increased by T treatment at embryonic day 20 (E20) and birth (P0). The observed modulation of the expression of GABA(A) receptor alpha2 subunit by T may be translated into changes in the levels or composition of GABA(A) receptor, either of which would be expected to alter neuronal functional response to GABA activation. As the effects of T are developmental-stage-specific, they may have an organizational impact on brain development.

Analysis of Variance↗
PubMed1999

New system for image analysis in nailfold capillaroscopy.

For quantitative evaluation of human TV nailfold capillary microscopy a new semi-automated image-analyzing system called "CapiShape" is presented. Skeletons and boundaries of capillaries are obtained by a special image processing algorithm to describe the shape of capillaries. In addition to conventional parameters such as diameters and loop widths for the size of single capillaries, new non-size parameters related to surface area and the skeletons are calculated. To describe capillary distribution in a nailfold, the ratio of distance between capillaries to its projection in the X axis, and area percentage are indicated. With different operators and different orientations of the camera, the measured differences in diameters and loop widths are smaller than 1.5 microm, and in area percentage smaller than 1.0%. As practical examples, applications of CapiShape to patients with scleroderma showed marked, significant differences in capillary size between patients and controls, patients with diabetes differed significantly in non-size parameters from controls. CapiShape is specially designed for clinical applications, and besides the usual measures new parameters for describing nailfold images may be developed. CapiShape is safe and easy to use for diagnosis, routine examination, and quantitative follow-up studies.

Adult↗
PubMed1999

[Postoperative infection outbreak of M. chelonae subsp. abscessus].

OBJECTIVE: To study the pathogen of postoperative infection outbreak in a hospital in Shenzhen. METHODS: According to the Laboratory Science Procedure of Diagnostic Bacteriology in Tuberculosis published by Chinese Antituberculosis Association, Bergey's Manual of Determinative Bacteriology (ninth edition), and the Clinical Bacteriology Examination & Development, 97 wound exudates were cultivated by the traditional bacteriologic method. The strains were identified with three standard strains of M. chelonae subsp. chelonae, M. chelonae subsp. abscessus and M. fortuitum as controls. RESULTS: 26 fast-acid positive and fast growth nontuberculous mycobacterium were isolated from 97 exudates, then 41 strains including other 15 strains which were collected from the hospital were identified as M. chelonae subsp. abscessus. CONCLUSION: The outbreak of the postoperative infection happened in the hospital was caused by M. chelonae subsp. abscessus.

Adult↗
PubMed1999

[Identification of postoperative M. chelonae infection outbreak by polymerase chain reaction of 16s-23s ribosomal DNA spacer sequence].

OBJECTIVE: To determine the pathogen of the infection outbreak in a hospital in Shenzhen at gene level with molecular biological technique, and to establish a rapid identification method of M. chelonae subsp. abscessus by polymerase chain reaction technique. METHODS: A single pair of primers and oligonucleotides probe of M. chelonae subsp. abscessus were designed, according to the sequence of mycobacterium of 16s-23s ribosomal DNA spacer sequences. 53 clinical strains were amplified by polymerase chain reaction, then dot-blot hybridization of PCR product was made. On the basis of this study, 259 lesion, tissue and normal tissue were amplified by 16s-23s rDNA PCR. RESULTS: 380 bp PCR product for 53 clinical strains was yielded by 16s-23s rDNA PCR, in the meantime, the specific hybridization dot appeared. The PCR positive rate of 259 specimens was 60.6%. CONCLUSIONS: The PCR products and dot-blot hybridization showed that the pathogen of the infection outbreak was M. chelonae subsp. abscessus at gene level. The 16s-23s rDNA PCR investigative system is sensitive and specific, which can identify M. chelonae subsp. abscessus.

DNA, Ribosomal Spacer↗
PubMed1999

[Spontaneous renal rupture].

OBJECTIVE: To study clinical regularity of spontaneous renal rupture. METHODS: 16 cases of this disease were reviewed. Renal carcinoma was found in 4, angiomyolipoma in 2, undetermined etiology in 3, and invasive colic cancer, kidney cyst, nephrolithiasis, SLE with nephritis, polycythemia vera, renal tuberculosis, portal hypertension in 1 each. RESULTS: CT demonstrated a sensitivity of 87.5% in identifying the underlying kidney mass, which was higher than that (25%) of B-type ultrasound and (0) KUB + IVU. Radical nephrectomy was carried out in 6 cases, renal-reserved operation in 5, and conservative treatment in 5. CONCLUSIONS: 60% of spontaneous renal rupture are due to kidney neoplasia. CT scanning is the most valuable diagnostic procedure. If the primary cause has not been clarified, close follow-up with periodic CT scanning might be mandatory.

Adult↗
PubMed1999

[Development of air microbe sampler with micropore filter membrane].

Dual head air microbe sampler with a large flow capacity of 100 liters per minute was manufactured. The sampler possesses simple structures, light weight, convenient operation and higher sampling efficiency, equal to 77%-96% of the grade six Anderson sampler. Sampling time is a main factor affecting sampling efficiency. This device is suitable for the determination of degree of biological clean air in clean environment and the detection of the pathogenic microbes in ward and public places and also microbes in ordinary environment.

Air Microbiology↗