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Biomedical subjects

X Jia

Publications and source records attributed to X Jia.

At least 55 records · Page 3Linked to original sources
PubMed2000

[A new strategy of gene therapy for hyperphenylalaninemia rats].

OBJECTIVE: To construct a recombinant vector which expresses active phenylalanine-amonia-lyase (PAL) in Lactococcus lactis (L. L.), and to convert phe into cinnamic acid in small intestine by the engineering L. L. to decrease the phe level in the peripheral blood, and to cure hyperphenylalaninemia rats. METHODS: PAL cDNA from Petroselinum crispum was subcloned into expression vector pMG36e and transformed L. L. The pMG36ePAL/L.L. was screened and characterized by using PCR and HPLC, and prepared as enteric-coated microcapsules and oral liquid type preparation that were given orally to hyperphenylalaninemia-rats. RESULTS: Engineering L. L. expressing PAL activity was obtained. The phe levels plasma of in the rats receiving preparations made from the engineering L. L. were significantly reduced compared with non-treated hyperphenylalaninemia rats. And the effects of different preparations were different from each other. CONCLUSION: The engineering L. L. expressing PAL activity can reduce the blood phe level of the hyperphenylalaninemia rats. This may be a potential way for PKU gene therapeutics.

Administration, Oral↗
PubMed2000

[Anisodamine in prevention and treatment of sepsis of severely burned patients].

OBJECTIVE: To observe the preventive effect of anisodamine on possible sepsis of patients with major burns and the effect of anisodamine on patients with sepsis. METHODS: Forty-two patients with extensive burn admitted to our burn institute from April 1998 to November 1999 were divided randomly into two groups: treatment group (T group) and control group (C group). In the T group, all 20 patients received fluid resuscitation regimen with anisodamine, and in the C group, 22 patients received the regimen with no anisodamine. A tonometry catheter was positioned in the stomach, connecting with the automatic gas analysis machine (Datex-Engstrom Corporation, Dutch) for determining gastric intramucosal pH (pHi). The plasma concentrations of diamine oxidase (DAO) and endotoxin were measured. Correlation analysis between pHi, DAO and endotoxin were made respectively during early stage of postburn. All the parameters in 7 patients with sepsis before and after administration of anisodamine were compared with those in 6 patients with sepsis without use of anisodamine. RESULTS: The incidence of sepsis in the T group was lower (20.0%) than that in C group (40.9%). The gastric pHi value in the early period of postburn was significantly higher in the T group than in the C group (P < 0.05). Concurrently, the plasma concentrations of DAO and endotoxin were significantly lower in the T group than in the C group (P < 0.05 or 0.01). A significant negative correlation was seen between the gastric pHi and respective values of DAO, endotoxin (P < 0.05 or 0.01). There were a decrease in gastric pHi, and an increase in plasma DAO and endotoxin level in patients with septic episode; however all the parameters after administration of anisodamine were improved compared with those in septic patients without use of anisodamine. CONCLUSIONS: Intestinal ischemic injury plays an important role in provoking sepsis during early postburn period. Anisodamine is effective in restoring intestinal circulation both in the shock phase and after the development of sepsis.

Adolescent↗
PubMed2000

[Clinical use of acellular allogenic dermis or acellular porcine dermis with split-thickness autologous skin graft in 119 cases].

OBJECTIVE: To observe the effect of acellular allogenic dermis or acellular porcine dermis together with split-thickness autologous skin graft on coverage of deep burn wound and the wound of scar excision. METHODS: Acellular allogenic dermis or acellular porcine dermis produced by our unit, with split-thickness autologous skin graft, were used in repairing various wounds in 119 cases. The take rate of various wounds was compared, and the take rate of wounds in which autologous skin from different sites was used to cover either acellular allogenic dermis or acellular porcine dermis was also compared. Histological examination and follow-up were made in some cases. RESULTS: After tangential excision, eschar excision and scar excision, the wounds were covered with either allogenic acellular dermis or porcine acellular dermis and autologous split-thickness skin. The take rate was found to be (93.4 +/- 3.4)%, (92.1 +/- 4.6)%, (94.5 +/- 3.5)%, respectively. There was no a significant difference in take rate (P > 0.05). No significant difference in take rate between the transplantation of allogenic acellular dermis with autologous split-thickness skin and transplantation of porcine acellular dermis with autologous split-thickness skin was found (P > 0.05). When autologous split-thickness skin harvested from the trunk or extremities was used, the take rate was (93.1 +/- 4.8)%, (89.0 +/- 6.2)%, respectively, whereas the take rate was only about 70% - 80% when skin harvested from the scalp was used. The take rate was only about 40% when acellular allogenic dermis and autologous micro-skin graft were used to cover the wound. Histological examination 19 months after the transplantation revealed normal structure. Collagenous fibers were orderly arranged. There was no apparent hyperplasia of collagenous fibers. Hair follicles, sweat glands and other skin appendages were not found in the healed area. Grossly, no obvious pigmentation was seen, the surface was smooth with slight wound contraction, and the consistency was flexible. CONCLUSION: Acellular allogenic split-thickness dermis or acellular porcine split-thickness dermis with autologous split-thickness dermis for coverage of deep burn wound and the wound of scar excision is an ideal material.

Adolescent↗
PubMed1999

Risk factors for meningioma in adults: a case-control study in northeast China.

A hospital case-control study of meningioma was conducted in Heilongjiang Province in northeast China between September 1989 and December 1996. It included 183 cases of newly diagnosed primary meningioma and 366 individually matched hospital controls with non-neoplastic and non-neurological disease selected from six major hospitals. Cases and controls were matched by sex, age and area of residence and interviewed in the hospital wards to obtain information on medical history, occupation and lifestyle. No association with liquor or beer consumption was apparent. Cigarette smoking was positively associated with meningioma risk in women but not in men. In women, compared with non-smokers, the adjusted OR for pack-years of smoking above the median (124) was 6.2 (CI 2.04-18.87). Both of these observations contrast with the results of a study of glioma in the same population, using similar methods. The risk of meningioma was positively associated with reported occupational exposure to lead, tin, cadmium and ionising radiation in both genders.

Adult↗
PubMed1999

Backbone dynamics of a short PU.1 ETS domain.

The resonance assignments, secondary structure and backbone dynamics of the ETS domain of the transcription factor PU.1 have been determined for the free protein in solution by NMR spectroscopy. The secondary structure for the free ETS domain is similar to that observed in the crystal structure of the PU.1 protein complexed with DNA, except that helix alpha2 and recognition helix alpha3 are shorter for the free protein in solution. Backbone dynamics of the protein have been examined using amide hydrogen-deuterium exchange and (15)N laboratory-frame spin relaxation measurements. A significant probability of local unfolding of helix alpha2, which precedes the loop-helix-loop DNA recognition domain, is inferred from the very fast hydrogen-deuterium exchange for amide protons in this helix. The (15)N relaxation measurements indicate that the protein is partially oligomerized at a concentration of 2.5 mM, but monomeric at a concentration of 0.3 mM. The (15)N relaxation data for the low concentration sample were interpreted, using the model-free formalism, to provide insight into protein dynamics on picosecond-nanosecond and microsecond-millisecond time scales. High flexibility of the protein backbone is observed for the residues in the loop between alpha2 and alpha3. This loop is variable in length and in structure within the class of winged helix proteins and is partially responsible for binding to DNA. The dynamic properties observed for alpha2, alpha3 and the intervening loop may indicate a correlation between protein plasticity in particular structural elements and recognition of specific DNA sequences.

Amino Acid Motifs↗
PubMed1999

Diet and brain cancer in adults: a case-control study in northeast China.

A hospital-based case-control study was conducted in the Heilongjiang Province of northeast China between May 1993 and May 1995. A total of 129 histologically confirmed brain cancer cases (73 gliomas and 56 meningiomas) and 258 matched controls were interviewed in 6 major hospitals to examine the influence of dietary factors in developing brain cancer. Information was obtained about frequency of consumption of 57 food items. Odds ratios (ORs) were obtained from conditional logistic regression, including allowance for socio-demographic factors, alcohol, tobacco and total energy intake. Consumption of fresh vegetables (OR = 0.29 for the highest quartile compared with the lowest one), and specifically of Chinese cabbage and onion, fruit (OR = 0.15), fresh fish (OR = 0.38) and poultry (OR = 0.16) was inversely related to the risk of developing brain cancer. A protective effect was also seen for vitamin E intake, calcium and, although non-significantly, beta-carotene and vitamin C. Risk of brain cancer increased with consumption of salted vegetables (OR = 2.54) and salted fish.

Adult↗
PubMed1999

Silicon bioavailability studies in young rapidly growing rats and turkeys fed semipurified diets: a comparative study.

Two experiments were conducted using completely randomized designs to study the bioavailability of Si from three sources to growing rats and turkeys fed semipurified diets. The basal diets were dextrose-egg albumin for rats and dextrose-casein for turkeys. The Si sources were tetraethylorthosilicate (TES), sodium silicate (NaSil), and sodium zeolite A (NaZA). Rats and turkeys were supplemented at 500 and 270 ppm Si, respectively, from each source. A control group of unsupplemented rats and turkeys was included in each experiment. In general, irrespective of Si source, Si supplementation slowed (p < 0.05 or p < 0.01) growth rates in both rats and turkeys. Although dietary Si supplementation reduced (p < 0.05) plasma Mg levels and liver Zn concentrations in rats, it increased (p < 0.05) plasma P and reduced (p < 0.05) plasma Cu levels in turkeys. Rats on TES had significantly slower (p < 0.05 or p < 0.01) growth rates (5-10%) than those on NaSil or NaZA. In rats, NaZA and TES reduced (p < 0.05) hemoglobin concentrations and plasma Zn, respectively. However, plasma Mg levels were higher (p < 0.05) in TES than NaSil- or NaZA-fed rats. The source of the dietary Si did not affect (p < 0.05) the organ weights of rats and their mineral concentrations. Turkeys on TES diets grew at a significantly faster (p < 0.05) rate (15%) than those on NaSil or NaZA diets during the first 2 wk of experimentation. However, after 4 wk, there were no significant(p > 0.05) differences in growth between the Si sources. In turkeys, NaZA increased (p < 0.05) hematocrit levels and plasma Mg levels. Turkeys on NaZA diets had larger (p < 0.05) hearts and livers than those on NaSil but not TES. Liver Mn content was higher (p < 0.05) in turkeys on NaSil than TES or NaZA. Heart Zn was lower (p < 0.05) in turkeys on NaSil than TES, but not NaZA.

Aluminum↗
PubMed1999

[Apoptosis in MT2 cells induced by HepG2.2.15 cells].

OBJECTIVE: To obtain the apoptosis in MT2 cells induced by HepG2.2.15 cells expressing Fas Ligand. METHODS: A human T-lymphotropic virus type I infected cell line MT2 was cultured overnight, then 0.5 ml serum contained hepatitis B virus DNA(HBV DNA), E antigen and S antigen was added to it together with 1 ml of fresh RPMI 1640 medium and incubated for 20-24 hours at 37 degrees C. The cells were washed three times with RPMI 1640 medium without serum, followed by continued incubation. The cells were harvested and Fas antigen were determined by immunohistochemistry. The cells expressed Fas antigen was added to HepG2.2.15 cells expressing Fas Ligand together with fresh RPMI 1640 medium and incubated for 48-72 hours at 37 degrees C. The apoptosis in MT2 cells was detected by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL). RESULTS: The Fas antigen was observed in MT2 cells harvested at 8-12 days post-infected, and the strong signals of apoptosis was observed in MT2 cells incubated together with HepG2.2.15 cells for 48-72 hours. CONCLUSION: MT2, a human T cell line infected with hepatitis B virus is able to express Fas antigen. The apoptosis in MT2 cells induced by HepG2.2.15 indicated that the T-lymphocyte in the quality of effective cell and the hepatocyte in the quality of target cell could be reversed in the pathogenesis of viral hepatitis.

Apoptosis↗
PubMed1999

[Studies of improving the frequency of wheat transformation by biolistic bombardment] [In Process Citation]

In the present study immature embryos of spring wheat Zhong-60634 were bombarded with gold particles coated with pAHC25 containing Bar and GUS genes. A total of 17 bialaphos-tolerant plants were obtained from 342 immature embryos which were first cultured for 3-4 days and then bombarded and selected. Integration of the introduced genes into the genome of transgenic wheat plants was shown by PCR and Southern analysis and transformation frequency was 0.88%. Furthermore, the present study showed that calli regeneration ability was improved while the embryo culture medium was supplemented with 2 mg/L dicamba instead of 2 mg/L 2,4-D. Meanwhile, in order to keep the calli differentiation ability calli should be transferred to differentiation medium supplemented with 3 mg/L bialaphos from calli selection medium with 5 mg/L bialaphos within a month.

Journal Article↗
PubMed1999

[Detection of alien chromatins introgressed into wheat in mitotic interphase] [In Process Citation]

Fluorescent in situ hybridization of biotin labelled total genomic DNA from alien species as probes was applied to illustrate chromatin behaviors of Secale cereale L., Thinopyrum intermedium Host., Avana fatua L., and Dasypyrum villosum (L.) Candagy introgressed into wheat (Triticum aestivum L.) in interphase cells. A pair of 1RS chromosome arms in 1BL/1RS translocations were visible as discrete domains traversing through the interphase nucleolus. The substitution and addition 1R chromosomes as well as the translocated chromosome segments of Th. intermedium and A. avena appeared as bright spots in interphase. In callli derived from immature embryos of a hybrid between T. durum-D. villosum amphidiploid and T. aestivum, seven D. villosum originated chromatins presented nearly consecutive trend from spots to domains. Chromatins from both parents did not tend to mix with each other at interphase of the hybrid calli. It is feasible to count the number of alien chromosomes and chromosome segments in the case of addition, substitution and/or translocation at interphase. As far as more alien chromosomes are considered, it seems not reliable to analyze the interphase nucleolus alone because some of the signals might be overlapped by chromatins of wheat. Neither S. cereale satellited chromosome 1R nor D. villosum 1V chromosome involving within the envelop of interphase nucleolus were associated with nucleoli, suggesting that their functions in the formation of nucleoli are inhibited in the wheat background.

Journal Article↗
PubMed1999

[Molecular identification and marker-assisted selection of Pm21 gene conferring resistance to powdery mildew in wheat] [In Process Citation]

RAPD marker (OPH17(1400)) and SCAR markers (SCAR1400 and SCAR1265) as well as fluorescence in situ hybridization (FISH) technique were used to detect wheat powdery mildew resistance gene Pm21 derived from Haynaldia villosa (6AL/6VS) in different genetic background of wheat breeding program. Among a total of 372 RAPD amplification reactions, 28 reactions (7.53%) yield no amplification products, and the amplification products of 21 reactions (5.64%) were difficult to interpret the presence or absence of the OPH17(1400), indicating that RAPD marker OPH17(1400) is less reproducible and reliable, so that its usage in breeding program is limited. However, SCAR markers, SCAR1400 and SCAR1265, were amplified in all 488 PCR reactions, suggesting that SCAR markers are highly reproducible and reliable, and can be used in breeding program. The specific SCAR1265 made it possible to screen a large number of genotypes reliably and rapidly in practical breeding programs for the presence/absence detection between the resistant and susceptible plants. After backcrossed with common wheat lines for several times, no recombination between the 6VS chromosome of Haynaldia villosa and any of the wheat chromosomes was detected by using FISH.

Journal Article↗
PubMed1999

Relationship of vascular remodeling and restenosis after interventional therapy: an experimental study on rabbit atherosclerotic iliac artery model.

OBJECTIVE: To evaluate the relative contribution of every part of vascular wall to lumen area loss after angioplasty. METHODS: Angioplasty was performed on rabbits iliac atherosclerosis model. Histomorphometric results of histological cross-sectional areas from target vessels of animals killed immediately after angioplasty (acute group, n = 20) were compared with those of the same areas from animals killed 4 weeks after the procedure (chronic group, n = 23), when restenosis occurred in this model. If taking 30% diameter decrease as restenosis criteria, the chronic group was further divided into two subgroups (nonrestenosis subgroup [NRS, n = 9] and restenosis subgroup [RS, n = 14]) and their histomorphometric results were also compared. RESULTS: The lumen area decreased by 0.48 mm2 from acute group to chronic group (acute group 0.86 +/- 0.23 mm2 vs chronic group 0.38 +/- 0.20 mm2, P < 0.001). Over the same period intimal area increased by 0.12 mm2 and the area circumscribed by inner elastic lamina (IEL area) decreased by 0.36 mm2. Intimal hyperplasia could only explain 25% of the later lumen area loss. We further found a more significant IEL area decrease in RS subgroup than in NRS subgroup (0.68 +/- 0.35 mm2 vs 0.94 +/- 0.14 mm2, P < 0.05), despite the same intimal area (0.39 +/- 0.16 mm2 vs 0.41 +/- 0.31 mm2, P = NS). The different lumen area between RS subgroup and NRS subgroup (0.27 +/- 0.10 mm2 vs 0.55 +/- 0.10 mm2, P < 0.001) was predominantly due to the greater IEL shrinking in RS subgroup. CONCLUSION: Our data indicate that later lumen area loss after angioplasty results from both intimal hyperplasia and arterial shrinking (remodeling), but the latter plays a much greater role.

Angioplasty, Balloon, Coronary↗
PubMed1999

[Experimental condition for WST-1 assay of skin viability].

OBJECTIVE: To investigate a new tetrazoliium salt assay (WST-1) of detecting tissue and cells of preserved skin. METHODS: With WST-1, viability of porcine and human skin split were assessed. The experimental condition such as dosage of agents, thickness of skin split, time of reaction, area of skin split and weight of skin split were determined. RESULTS: Optimal experimental condition of skin split should be 10 mm diameter and 0.3 mm thick, incubation for 3 hours at 37 degrees C, and reagent dosage of 20 microl. CONCLUSIONS: As a reagent for detecting cell viability, WST-1 is successfully applied to the assessment of skin viability.

Animals↗
PubMed1999

[Longitudinal observation on a schistosome-infected snail spot as a source of infection in a mountainous village of Dali city].

AIM: To observe longitudinally the changes in survival and infection rate of Oncomelania snails in a positive snail spot in Yunnan. METHODS: A positive snail spot in a ditch in Shalimuzhuang Village, Dali City, was continually observed on the changes in the density of snail population and natural infection rate of the snails by random environmental sampling for 8 times in 4 successive years. RESULTS: During the 8 times of snail survey, living snails were found relatively stable in the ditch, in which positive snails were obtained in 6 occasions, the average infection rate being 3.99%. CONCLUSION: The density and the positive rate of snails in the mountain region remains relatively stable as a source of human infection. Elimination of the positive snail spots is necessary for controlling schistosomiasis.

Animals↗
PubMed1999

Differential gene expression in retina of myopic chicken eyes using mRNA differential display.

PURPOSE: To study differentially expressed genes in retina of experimental myopic chicken. METHODS: Experimental myopia in chicken was induced by form-deprivation. The mRNA in chicken retina was analyzed by using differential display. RESULTS: Experimental myopia was successfully induced in chicken through form-deprivation. Differentially expressed gene fragments were detected in retina of chicken with myopic development and recovery as compared with normal controls. CONCLUSION: The differential display of mRNA may be a useful way in cloning myopic-related genes.

Animals↗
PubMed1999

[Study on the catalytic spectrophotometric determination of trace manganese].

A new catalytic spectrophotometric method for determining trace amounts of manganese has been developed. The method is based on catalytic oxidation of morin by hydrogen peroxide. Manganese has catalytic effect. The detection limit for manganese is 0.004 microg/mL. The linear range of the determination is 5-80 ng/mL of manganese. The method has been used to determine trace manganese in wine.

Catalysis↗
PubMed1999

[Anharmonicity of local vibrational mode of carbon acceptor in GaAs and its effect on main absorption band].

A sideband on the low energy side of the local-vibrational-mode main absorption band of carbon acceptor in GaAs was observed. The difference between the peak frequency of the main absorption band and that of the sideband is 3.5 cm(-1). The integrated absorption of the sideband varies with temperature and has an effect on the temperature dependence of the main absorption band. It is likely that the sideband originates from the anharmonicity of the local vibrational mode itself.

English Abstract↗