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Biomedical subjects

Jin Xu

Publications and source records attributed to Jin Xu.

At least 91 records · Page 5Linked to original sources
PubMed2003

[Study on the effect of the growth and aflatoxin production by Aspergillus flavus parasiticus NRRL 2999 in the present of Lactobacillus plantarum ATCC 8014].

The effect of L. plantarum ATCC 8014 on growth and aflatoxin B1 production of A. flavus subsp. parasiticus NRRL 2999 was studied and determined. A spore suspension of Aspergillus flavus parasiticus NRRL 2999 is inoculated into MRS medium containing L. plantarum and incubated at 28 degrees C for 15 days. The pH of the medium, weight of mycelia and aflatoxin B1 production were determined on day 3, 6, 9, 12, 15 of incubation. The growth of A. flavus subsp. parasiticus NRRL 2999 was inhibited when spores were added to a 24 h L. plantarum ATCC8014 culture and when both organisms were added simultaneously. The inhibition of the growth of A. flavus subsp. parasiticus NRRL 2999 was probably due to inactivating the viability of spores. The spores of A. flavus subsp. parasiticus NRRL 2999 became swollen in the presence of L. plantarum ATCC8014 culture, at the same time, and A. flavus subsp. parasiticus NRRL 2999 also affected the shape of L. plantarum ATCC8014 cells, which became enlarged. However, when L. plantarum ATCC8014 was added to a 3-day A. flavus subsp. parasiticus NRRL 2999 culture, there was not effect on mold growth and aflatoxin B1 production. Lactic acid inhibited growth of A. flavus subsp. culture in the MRS medium with initial pH value of 4.5. However, the production of aflatoxin B1 was not affected.

Aflatoxin B1↗
PubMed2003

[Relationship between early enhanced helical CT and tumor angiogenesis in bladder cancer].

OBJECTIVE: To study the relationship between enhanced degree in the cancer lesion and angiogenesis in the tumor through early manifestations in enhanced helical CT in patients with bladder cancer. METHODS: Fifty-three patients with bladder carcinoma were examined by pelvic plain CT and helical CT scan at peak enhancement of cancer lesion. Histologic grade, vascular endothelial growth factor (VEGF) and micro-vascular density (MVD) were analyzed for each resected cancer lesion. Pearson and Spearman correlation tests were used to assess the relationship between CT enhancement and histologic grade, VEGF or MVD. RESULTS: In early enhancing phase of helical CT, different degrees of enhancement were observed in 73 bladder cancer lesions. The difference between average CT attenuation and MVD in different histologic grade cancer lesions was statistically significant (P < 0.001). A positive correlation was found between the CT enhancement and MVD (gamma = 0.936, P < 0.001), histologic grade (gamma = 0.75, P < 0.001), but VEGF of bladder cancer did not correlate with the CT enhancement or MVD. CONCLUSION: The early enhancement of helical CT enhancement of bladder cancer, showing a positive relation to MVD and histologic grade, can reflect the tumor angiogenesis and blood supply.

Adult↗
PubMed2003

[Molecular biology of aflatoxin biosynthesis].

This review provides several important breakthroughs on the molecular biology of aflatoxin biosynthesis and information on the regulation and evolution of the aflatoxin pathway, and the elimination of the toxin from the food chain as well.

Aflatoxin B1↗
PubMed2002

A comparison of safety, tolerability and immunogenicity of Oka/Merck varicella vaccine and VARILRIX in healthy children.

This study compared safety, tolerability, and immunogenicity of the Oka/Merck varicella vaccine and VARILRIX [Oka-RIT strain SmithKline Beecham Biologicals] in healthy children 12-24 months of age. Subjects were randomized in this double blind study to receive either a single dose of Oka/Merck varicella vaccine, (approximately 50,000 plaque forming units (PFU), Group A or approximately 16,000 PFU, Group B) or 1 dose of VARILRIX, (approximately 40,000 PFU/dose, Group C). Safety profiles in each treatment group were similar. The proportions of subjects achieving a 6-week postvaccination titer> or = 5 gpELISA units in Groups A, B or C were 97.1, 95.2 and 85.6%, respectively.

Antibodies, Viral↗
PubMed2002

Dynamic docking of myosin and actin observed with resonance energy transfer.

Atomic models of myosin subfragment-1 (S1) and the actin filament are docked together using resonance energy-transfer data from both pre- and postpowerstroke conditions. The quality of the resulting best fits discriminated between neck-region orientations of the S1 for a given set of experimental conditions. For measurements of the postpowerstroke states in the presence of ADP, resonance energy-transfer data alone are sufficient to dock the atomic models and provide evidence that S1 exists with at least two neck-region orientations under these conditions. To dock the prepowerstroke state, resonance energy-transfer data were used in combination with previous chemical cross-linking data to determine that a neck-region orientation similar to that of a proposed prepowerstroke state best fit the data. The resulting models determined independently from electron microscopy compare favorably with micrographs from the recent literature. The docking models by resonance energy transfer suggest that the larger movements in the light-chain binding domain are accompanied by twisting and rotating movements of the catalytic domain, causing a tilt of approximately 30 degrees during the weak-to-strong transition. This transition provides the displacement necessary to support motility and force generation.

Actins↗
PubMed2002

A multichannel scala tympani electrode array incorporating a drug delivery system for chronic intracochlear infusion.

We have developed a novel scala tympani electrode array suitable for use in experimental animals. A unique feature of this array is its ability to chronically deliver pharmacological agents to the scala tympani. The design of the electrode array is described in detail. Experimental studies performed in guinea pigs confirm that this array can successfully deliver various drugs to the cochlea while chronically stimulating the auditory nerve.

Animals↗
PubMed2002

Isolation of streptonigrin and its novel derivative from Micromonospora as inducing agents of p53-dependent cell apoptosis.

Streptonigrin (1) and its novel natural derivative 7-(1-methyl-2-oxopropyl)streptonigrin (2) were isolated from an actinomycete strain, Micromonospora sp. IM 2670. The inductions for 1 and 2 are more potent in the human neuroblastoma SH-SY5Y cells that contain wild-type p53 than in SH-SY5Y-5.6 cells that overexpress a dominant negative mutant of p53, thus suggesting that they induce apoptosis through a p53-dependent pathway.

Apoptosis↗
PubMed2002

Dopamine-dependent neurotoxicity of alpha-synuclein: a mechanism for selective neurodegeneration in Parkinson disease.

The mechanism by which dopaminergic neurons are selectively lost in Parkinson disease (PD) is unknown. Here we show that accumulation of alpha-synuclein in cultured human dopaminergic neurons results in apoptosis that requires endogenous dopamine production and is mediated by reactive oxygen species. In contrast, alpha-synuclein is not toxic in non-dopaminergic human cortical neurons, but rather exhibits neuroprotective activity. Dopamine-dependent neurotoxicity is mediated by 54 83-kD soluble protein complexes that contain alpha-synuclein and 14-3-3 protein, which are elevated selectively in the substantia nigra in PD. Thus, accumulation of soluble alpha-synuclein protein complexes can render endogenous dopamine toxic, suggesting a potential mechanism for the selectivity of neuronal loss in PD.

14-3-3 Proteins↗
PubMed2002

[The status of auditory function in auditory neuropathy].

OBJECTIVE: To study the status of auditory function and the site of lesion in auditory neuropathy. METHOD: The data of 65 patients were analyzed including the clinic signs, pure tone audiometry, auditory brainstem response(ABR), 40 Hz auditory event related potential(40 Hz AERP) and otoacoustic emissions (OAEs). RESULT: The low frequency hearing loss in auditory neuropathy arose from the lesion of retrocochlear auditory afferent and efferent nerve and auditory brainstem, presented at the abnormality of acoustic reflex, efferent suppreSsion, ABR and the unparallel relationship between evoked OAE amplitude and pure tone threshold. To corresponding, the outer hair cells in low frequency region were out of suppression, presented at the strong response of SOAE, TEOAE and DPOAE in low frequency region. The high frequency hearing loss in auditory neuropathy arose from the lesion of cochlear outer hair cells, presented at the parallel relationship between DPOAE amplitude and pure tone threshold in high frequency region. The intermediate frequency hearing loss in auditory neuropathy was damaged gently or close to normal, presented at both pure tone threshold and DPOAE amplitude nearby 2 kHz were close to normal. CONCLUSION: The dysfunction in differ degree lied in the afferent and efferent nervous systems and cochlear level in auditory neuropathy, the main site of lesion was in the cochlear afferent and efferent nerve, up to the brainstem and down to the cochlea.

Adolescent↗
PubMed2002

[Repair of the facial tissue defects with reversed narrow pedicle lateral maxillocervical fasciocutaneous flap].

OBJECTIVE: To introduce a method of repairing facial tissue defects caused by various factors. METHODS: The reverse narrow pedicle lateral maxillocervical fasciocutaneous flap was designed with its pedicle located in front of auricle. The size of the flaps ranged from 5 cm x 6 cm to 10 cm x 11 cm. The length and width of the pedicle ranged 2 cm-5 cm and 1 cm-1.5 cm. RESULTS: This fasciocutaneous flap was used in 21 cases. All flaps survived except 1 flap showing distal skin necrosis. CONCLUSION: This fasciocutaneous flap didn't include any major blood vessel. The ratio of the pedicle width to flap length broke that of traditional flap and was reverse transfer. The transposition of the narrow pedicle flap was easy. The postoperative appearance (color, texture, cosmetic aspect) was satisfactory. This method was a new design and was ideal for large facial tissue defect repair.

Adolescent↗
PubMed2002

[Usages of some common words and expressions in English medical papers].

This article deals with frequent errors and misuses of the words and expressions in English medical paper by Chinese authors. According to the frequency of appearance in English medical literature, the usage of certain frequent words and expressions is given, which may facilitate English medical paper writing of Chinese authors.

Publishing↗
PubMed2002

[Biological synthesis and application of bacteriocins].

Bacteriocins produced by lactic acid bacteria are a heterogeneous group of peptide inhibitors. Most of bacteriocins have relatively narrow inhibitory spectra. A few of them have wider inhibitory spectra, being active against a wide range of gram-positive bacteria. Bacteriocins can be divided into three types. There are small heat-stable peptides, large heat-labile proteins, and lantibiotics. Their physico-chemical nature, genetic behavior and application are reviewed.

Bacteriocins↗
PubMed2002

[A simple method for screening of highly inhibitory Lactic acid bacteria on Aspergillus flavus growth].

A simple and rapid method for screening of Lactic acid bacteria with high inhibitory power is developed. The methodology employed was the agar-diffusion assay, which was standardized for medium composition, and incubation conditions. The assay was composed of two layers of medium, MRS agar at the bottom of plate, PDA at the top of MRS agar. Lactic acid bacteria culture was inoculated to the media between MRS and PDA, then a known number of mold spores was surface plated on PDA plates, and incubated at 25 degrees C for 72 h.

Aspergillus flavus↗
PubMed2002

[Inhibition of Lactobacillus species on the germination of Aspergillus flavus spore].

Actively growing Lactobacillus plantarum CGMCC 1.1856 cells totally inhibited the germination of mold spores. Cell-free supernatant broth from the fermentation of Lactobacillus plantarum could not destroy the viability of mold spore. While the pH of the culture broth and supernatant were about 4.0, and the acidification of non-fermented broth to pH 4.0 with lactic acid could not cause a similar inhibition on spore germination. This experiment discounted the possibility that the inhibitory effect on mold growth was due to the lactic acid produced by Lactobacillus, and suggested that the effect was because of both low pH and microbial competition.

Aspergillus flavus↗
PubMedDate not supplied

DNA computation model to solve 0-1 programming problem.

0-1 programming problem is an important problem in opsearch with very widespread applications. In this paper, a new DNA computation model utilizing solution-based and surface-based methods is presented to solve the 0-1 programming problem. This model contains the major benefits of both solution-based and surface-based methods; including vast parallelism, extraordinary information density and ease of operation. The result, verified by biological experimentation, revealed the potential of DNA computation in solving complex programming problem.

Algorithms↗
PubMedDate not supplied

DNA solution of a graph coloring problem.

The graph-theoretic parameter that has probably received the most attention over the years is the chromatic number. As is well-known, the coloring problem is an NP-Complete problem. In this paper, it has been solved by means of molecular biology techniques. The algorithm is highly parallel and has satisfactory fidelity. This work shows further evidence for the ability of DNA computing to solve NP-Complete problems.

Base Sequence↗