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Biomedical subjects

Z Peng

Publications and source records attributed to Z Peng.

At least 91 records · Page 5Linked to original sources
PubMed1999

[Expression of heat shock protein (HSP70) in normal endometrium and endometrial carcinomas].

Expression of heat shock protein 70 (HSP70) in normal endometrium tissue and endometrial carcinoma was analyzed by the present authors to determine the relationship between HSP70 expression and the prognosis of endometrial carcinomas. The immunohistochemical reactivity of monoclonal antibodies against HSP70 was examined in 44 endometrial carcinomas and 40 normal endometria HSP70 respectively. HSP70 was expressed stronger in carcinomas than in normal. Expression of HSP70 was found in 56.82% of endometrial carcinomas and was well correlated with histological grade (P < 0.05). These results suggest that HSP70 may play a role in the prognosis of endometrial carcinomas.

Endometrial Neoplasms↗
PubMed1998

Immunoblot analysis of salivary allergens in 10 mosquito species with worldwide distribution and the human IgE responses to these allergens.

BACKGROUND: Most people develop skin reactions to mosquito bites, however, little is known about mosquito salivary allergens and the IgE responses to them. OBJECTIVES: We sought to identify these allergens and the specific IgE responses they elicit. METHODS: Saliva or salivary gland extracts were prepared from 10 mosquito species, including seven species with worldwide distribution: Aedes (Ae.) aegypti, Ae. vexans, Ae. albopictus, Ae. togoi, Ae. triseriatus, Culex (Cx.) quinquefasciatus, Cx. pipiens, Cx. tarsalis, Anopheles (An.) sinensis, and Culiseta (Cs.) inornata. Proteins from these preparations were separated by sodium dodecylsulfate-polyacrylamide gel electrophoresis and transferred to nitrocellulose membranes, which were immunoblotted by sequential incubations with human serum, monoclonal anti-human IgE, and enzyme-conjugated goat anti-mouse IgG. Salivary allergens were analyzed by using a pooled serum from subjects allergic to mosquitos. Individual IgE responses to each allergen were evaluated in 12 subjects allergic to mosquitos living in Canada, the United States, and China, as well as in five subjects not allergic to mosquito bites. To study species-shared allergens, the membranes were immunoblotted with two rabbit antibodies specific to recombinant mosquito salivary proteins. RESULTS: Three to sixteen salivary allergens with molecular masses ranging from 16 to 95 kd were found in each species. Both species-shared and species-specific allergens were identified by molecular masses, binding to the two rabbit antibodies, and individual IgE responses to species indigenous to and absent from the regions where the subjects lived. Salivary allergens, especially from Ae. aegypti, Ae. vexans, and Ae. albopictus, elicited higher IgE responses in subjects allergic to mosquitos than in nonallergic subjects. CONCLUSIONS: Species-shared and species-specific allergens that cause IgE responses in subjects allergic to mosquitos are immunologically identified. Species-shared allergens are the most important for potential use in diagnosis and immunotherapy.

Allergens↗
PubMed1998

Highly sensitive and specific ELISA with monoclonal antibody capture to measure Dermatophagoides farinae 1-specific IgE.

BACKGROUND: Dermatophagoides farinae (Der f) is a major allergen in Der f extract. Measurement of Der f I-specific IgE has not been commonly used, because of the difficulty in obtaining large amounts of purified Der f 1. OBJECTIVES: To improve the diagnosis of dust mite allergy, we wanted to develop an ELISA to measure Der f 1-specific IgE in which purified Der f 1 is not required. METHODS: Using a monoclonal antibody (mAb) against Der f 1, a mAb-capture ELISA was developed. Microplates coated with the mAb were sequentially incubated with crude Der f extract, serum samples, goat anti-human IgE, and conjugated rabbit anti-goat IgG. A conventional ELISA using purified Der f 1 as capture (Der f 1-ELISA) was developed to compare it with the mAb-capture ELISA. RESULTS: There was a significant correlation between the two ELISAs (r = 0.89, P < .001) with a sensitivity of 0.8 U/mL. Both the assays were inhibited by the crude Der f extract in a dose-dependent manner. Using the two ELISAs, serum Der f 1-specific IgE was evaluated in 12 allergic patients with positive skin tests to Der f extract, 14 allergic patients with negative skin tests to Der f extract, and 15 healthy subjects. The mean Der f 1-IgE and the positivity rate of Der f I-IgE were higher in the mite-allergic group and lower in the healthy group when the mAb-ELISA was used (P < .01) than when the Der f 1-ELISA was used (P < .05). CONCLUSIONS: Der f 1-specific IgE can be measured by mAb-capture ELISA using crude Der f extract. The mAb-ELISA is more sensitive and specific than the conventional Der f 1-capture ELISA in diagnosing dust mite allergy.

Adolescent↗
PubMed1998

Comparison of three-point bending test and peripheral quantitative computed tomography analysis in the evaluation of the strength of mouse femur and tibia.

We compared the mechanical and densitometric testing methods in evaluating the mechanical strength of mouse cortical bones. The femora and tibiae of 10 male mice (weight 32.8 +/- 4.0 g) were utilized. Volumetric cortical bone mineral density (vCtBMD), cross-sectional cortical area at midshaft (CSA), cross-sectional moment of inertia (CSMI), and strength strain index (SSI) were measured by peripheral quantitative computed tomography (pQCT). The precision of pQCT expressed as a coefficient of variation (CV) was 1.1%, 2.7%, and 6.4% for vCtBMD, CSA, and CSMI, respectively. The mechanical properties were measured by a three-point bending test. The method error measured from paired bones was 7.3%-10.1% for breaking bending force, 15.0%-15.2% for stiffness, 2.0%-2.4% for vCtBMD, 5.2%-6.4% for CSA, 13.5%-17.6% for CSMI, and 8.9%-18.1% for SSI. CSMI and CSA were found to be the best explanatory variables for the breaking force of femur and tibia, respectively, while CSA and CSMI were the best predictors for the elastic modulus of femur and tibia, respectively. CSA had a higher correlation with mechanical parameters than vCtBMD. On the basis of this study, the mechanical tests and the pQCT measurements are relevant in biomechanical studies on mouse bones and justify the use of the murine model. High-resolution pQCT gives better precision than the three-point bending test in studies of mouse bones.

Animals↗
PubMed1998

Effect of clodronate treatment on established bone loss in ovariectomized rats.

The ability of clodronate to prevent bone loss and weakening of bone strength was studied in adult rats with established osteopenia. Six-month-old female Sprague Dawley rats were randomized into 13 groups. One group was killed at the start of the study, nine groups were ovariectomized (ovx), and three groups sham-operated (sham). After 4 months, the ovx rats were given either clodronate or vehicle subcutaneously (s.c.), once a week for 3 or 6 months, the cumulative doses of both dosing regimens being 36, 84, and 300 mg/kg. Clodronate reduced the increase in bone turnover as evidenced by serum osteocalcin and urinary deoxypyridinoline. Cancellous bone loss was more severe in distal femur than in lumbar vertebral body already at 4 months after ovx. Cortical osteopenia of femoral middiaphysis was significant at 7 and 10 months after operation and was in accordance with the impaired bending strength of the femoral shaft. In the tibia, the bending strength was, by contrast, increased at each timepoint after ovx. In distal femur, higher values of cancellous bone volume (BV/TV) were found after 6 months of clodronate treatment than in ovx/vehicle-treated rats. In lumbar vertebrae, only the lowest dose of clodronate slightly counteracted the ovx-induced further decrease in BV/TV, but reduced, at all dosages, the impairment of lumbar vertebral compression strength. The maximum load of femoral neck did not differ between vehicle-treated ovx and sham groups after clodronate treatment, but clodronate reduced the weakening of femoral shaft. A further increase in the bending strength of the tibia was found after clodronate treatment. There was a positive correlation between bending strength and ash weight in both the tibia and the femur. Histomorphometry further showed that long-term use of clodronate does not impair bone mineralization or affect modeling-dependent bone formation. In conclusion, clodronate treatment clearly slows down the progress of bone loss and prevents further weakening of bone strength in femoral shaft and vertebrae, even though it cannot completely reverse the effects of ovariectomy-induced changes in established osteopenia.

Amino Acids↗
PubMed1998

Laparoscopic cholecystectomy using 2-mm instruments.

Today, laparoscopic cholecystectomy is the method of choice for treatment of symptomatic gallbladder disorders. It minimizes effects of the operation that are independent of the gallbladder, such as trauma to the abdominal wall and other soft tissue. The surgical wounds were even smaller when 2-mm trocars were used. Laparoscopic cholecystectomy using 2-mm instruments was performed in a consecutive series of 14 patients with symptomatic gallstones. The procedure was completed in 12 cases, with conversion to open surgery in two cases. Intraoperative cholangiography was always performed. The postoperative course was always uneventful. The cosmetic effect was highly satisfactory. The procedure using 2-mm instruments could be indicated in selected patients with uncomplicated gallstone disease.

Adult↗
PubMed1998

Characterization of functional regions in the Schizosaccharomyces pombe mei3 developmental activator.

The Schizosaccharomyces pombe mei3(+) gene is expressed only in diploid cells undergoing meiosis. Ectopic expression of mei3(+) in haploid cells causes meiotic catastrophe. Mei3 is an inhibitor of Ran1/Pat1 kinase and contains a nine-amino-acid motif, Mei3-RKDIII, that resembles two regions in the Ste11 substrate for Ran1/Pat1. Substitution of serine for Arg-81 within Mei3-RKDIII transforms the inhibitor into a substrate for Ran1/Pat1. Thus, it is likely that Mei3-RKDIII defines a pseudosubstrate sequence. In this study, we constructed a series of mei3 deletion mutations and assayed each for activity. This analysis indicates that the carboxy-terminal domain of Mei3 is sufficient for function in vivo. Alanine-scanning mutagenesis identifies critical residues within the inhibitory domain. Two mutations, SM1 and SM8, fail to cause meiotic catastrophe. The SM1 mutation contains alterations of amino acid residues in Mei3-RKDIII. Recombinant SM1 protein exhibits reduced ability to inhibit Ran1/Pat1 kinase in vitro and interacts inefficiently with the kinase in a two-hybrid assay. The SM8 protein binds to Ran1/Pat1 in a two-hybrid assay but fails to inhibit Ran1/Pat1 substrate phosphorylation in vitro. These findings provide evidence that Mei3-RKDIII defines a Ran1/Pat1-binding site that is necessary but not sufficient for inhibition of the kinase. Using fusions to green fluorescent protein, the cellular localization of Ran1 and Mei3 was examined in living cells. Ran1 is concentrated in the nucleus. Mei3 is also enriched in the nucleus and, consistent with the genetic and biochemical results, the inhibitory domain of Mei3 is sufficient for nuclear localization.

Amino Acid Sequence↗
PubMed1998

Forensic medicine in China.

Although China has a long history of forensic medicine, with the first standard text published in 1247, modern practices appeared only in the 1930s under Professor Lin Ji. After the founding of the People's Republic of China in 1949, there was a period of rapid development, which was later interrupted by the Cultural Revolution of 1966-1976. Today, China has about 10,000 experts in forensic medicine organized within the separate agencies of police, prosecutor's offices, courts, universities, and the Justice Ministry. Eight medical colleges, the Institute of Forensic Sciences of the Ministry of Justice in Shanghai which publishes the Journal of Forensic Medicine, and the Forensic Medicine Association of China which publishes the Chinese Journal of Forensic Medicine are key organizations.

China↗
PubMed1998

Expression and rapid purification of an Aedes aegypti salivary allergen by a baculovirus system.

Mosquito salivary proteins cause allergic reactions in humans. Recombinant salivary allergens will facilitate both the diagnosis and immunotherapy of mosquito allergy. The Aed a 1, a 68-kD apyrase in the saliva of Aedes aegypti, has been demonstrated to be an allergen which binds to the IgE of mosquito-allergic subjects. The baculovirus expression vector pBlueBacHis C equipped with an N-terminal histidine tag was used to express the Aed a 1 protein. The cDNA coding for the 3' significant portion of Aed a 1 (Aed a 1 3') (150-562 amino acid residues) was cloned into pBlueBacHis C. The rAed a 1 3' protein expressed by recombinant baculovirus was verified by immunoblot using anti-Aed a 1 and anti-histidine antibodies, respectively. The histidine-tagged fusion protein was purified to apparent homogeneity from infected Sf9 cells by Ni2+ resin affinity chromatography. Both immunoblot and ELISA showed that the purified rAed a 1 3' binds to the IgE and IgG in mosquito allergic sera, indicating that the antigenicity of the rAed a 1 3' is identical to the native Aed a 1 of Aedes aegypti saliva.

Aedes↗
PubMed1998

A mouse model of mosquito allergy for study of antigen-specific IgE and IgG subclass responses, lymphocyte proliferation, and IL-4 and IFN-gamma production.

To date, there are no ideal animal models for study of natural sensitization leading to IgE- and lymphocyte-mediated hypersensitivities. We established such a model in which four BALB/c mice were each sensitized by exposure to at least 16 mosquito Aedes aegypti bites, twice a week for 4 weeks. Four non-exposed control mice were also studied. Mosquito A. aegypti head and thorax extract, saliva, and two recombinant salivary allergens (rAed a 1 and rAed a 2) were used in vitro as antigens. Intradermal tests were performed. Serum mosquito antigen-specific IgG, IgG1, IgG2a, and total IgE were measured by ELISA; specific IgE was measured by passive cutaneous anaphylaxis (PCA). IgE responses to each antigen in the saliva were analyzed using Western blotting. Spleen lymphocyte proliferation assays were performed to determine the cell-mediated hypersensitivity response. Antigen-induced IL-4 and IFN-gamma production in the spleen lymphocytes were evaluated using ELISA. After 4 weeks, all 4 mosquito-sensitized mice developed a positive immediate wheal 20 min after skin tests with mosquito antigens, and a positive delayed papule 24 h later, while control mice did not. Also, the sensitized mice had a positive PCA response, which correlated significantly with total IgE levels (r = 0.84, p<0.05), confirming the presence of antigen-specific IgE, while none of control mice had a positive response. Antigen-specific IgG1, but not IgG2a, was increased in the sensitized mice (p<0.01). Western blotting showed that 5 of the 8 antigens which elicited mouse IgE responses, including 2 major antigens, also elicited human IgE responses. The mean lymphocyte proliferation response to mosquito antigens also elicited human IgE responses. The mean lymphocyte proliferation response to mosquito antigens was significantly increased in the sensitized mice (p<0.05). IL-4 production was significantly increased and IFN-gamma production was decreased, further suggesting that a Th2 immune response predominates despite the development of the delayed skin reaction. This new model of natural sensitization without using an adjuvant is potentially useful for the study of other allergic disorders as well as mosquito allergy.

Allergens↗
PubMed1998

Clodronate prevents osteopenia and loss of trabecular connectivity in estrogen-deficient rats.

Daily oral clodronate treatment was evaluated in Sprague-Dawley rats for its ability to inhibit estrogen-deficiency-induced changes in femoral neck, femoral diaphysis, and lumbar vertebrae (L4-L5). Six-month-old ovariectomized (OVX) rats were administered by gavage a vehicle (Veh) or clodronate (100 or 500 mg/kg/day). Sham-operated (SHAM) control rats received the vehicle (n = 15/group). Treatment was started on the day of operation and continued for 3 months. Trabecular bone volume (BV/TV) and structural variables (trabecular number, Tb.N; thickness, Tb.Th; separation, Tb.Sp; and trabecular bone pattern factor, Tb.Pf) were assessed on secondary spongiosa of the right femoral neck Furthermore, cantilever bending test of the left femoral neck and compression test of L4, ash weight of L5, and morphometric studies of femoral diaphysis were carried out, and serum and urinary markers of bone turnover were determined. The OVX/Veh group had higher levels of serum osteocalcin and alkaline phosphatase and higher urinary excretion of deoxypyridinoline/creatinine than the SHAM/Veh group at 3 months postsurgery, and clodronate reduced these changes. BV/TV of femoral neck, bone mass of L5, and the maximum loads of the femoral neck and L4 were lower after OVX than SHAM operation. Although clodronate prevented trabecular bone loss in the femoral neck and preserved Tb.Pf at the SHAM control level, it failed to preserve the mechanical strength at the femoral neck However, in lumbar vertebrae, clodronate prevented the loss of bone mass and mechanical properties. Furthermore, there was a good positive correlation between maximum load of L4 and the ash weight of L5 (n = 58, r = 0.69, p < 0.001). In the femoral neck (n = 55), Tb.Pf correlated negatively with BV/TV and Tb.N (r = -0.59 and r = -0.55;p < 0.001, respectively) and positively with Tb.Sp (r = 0.61, p < 0.001). In femoral mid-diaphysis, there were no significant changes in cortical bone geometry in any of the groups. We conclude that orally administered clodronate suppresses the enhanced bone turnover in adult OVX rats and preserves trabecular bone volume and connectivity in the femoral neck In the axial skeleton, clodronate has a beneficial effect on lumbar vertebral bone mass and strength.

Administration, Oral↗
PubMed1998

[Epidemiologic and experimental studies on epidemic haemorrhagic fever virus in pigs].

In order to study the roles of pigs with epidemic haemorrhagic fever virus, epidemiologic and experimental studies were carried out in pigs. Aetiological, serological and polymerase chain reaction (PCR) techniques were performed. Results showed that not only pigs could be infected with EHFV under natural or experimental conditions but susceptible to EHFV as well. Virus may disseminate to many organs of the animals through blood and cause transient pathologic changes. EHFV duplicates inside the animal bodies and be excreted to cause pollution of environment. It is possible that pigs serve as sources of EHF infection. Our research data also showed for the first time that EHEV were vertically transmitted through the placenta of pigs. There was no evidence showing that people raising pigs were symptomatically sick due to EHF infection.

Animals↗
PubMed1998

[Analysis of HLA-DRB1 allele in patients with chronic bronchitis].

OBJECTIVE: To study the difference in HLA-DRB1 allele frequencies between patients with simple chronic bronchitis and with coal worker's pneumoconiosis (CWP) complicated with chronic bronchitis. METHODS: HLA-DRB1 allele frequencies were measured in 37 patients with simple chronic bronchitis and 33 with CWP complicated with chronic bronchitis of Han ethnicity in Shanxi Province using polymerase chain reaction with sequence specific primer, in comparison with those in normal population of the same province. RESULTS: Allele frequency of HLA-DRB1 * 120X was 24.32% in those with simple chronic bronchitis, and that of HLA-DRB1 * 040X was 22.73% in those with CWP complicated with chronic bronchitis, significantly increased than that in normal people with both P < 0.01. There was no significant difference in other alleles between the three groups. CONCLUSION: It suggests that in Han ethnicity of Shanxi Province HLA-DRB1 * 120X allele frequency is associated with simple chronic bronchitis and that of HLA-DRB1 * 040X is associated with CWP complicated with chronic bronchitis.

Alleles↗
PubMed1998

[Gamma knife treatment of meningiomas].

From October 1995 to July 1997, 52 cases of meningioma were treated with gamma knife radiosurgery. Twenty-eight cases were followed up by CT or MR. The follow-up period was from 2 to 22 months. Follow-up imaging evaluation showed tumor size shrinkage in 8 cases, central density decrease in 10 cases, no change in 8 cases and tumor volume increase in 2 cases. The actual 1-year tumor growth control rate was 92%. Radiation-induced edema was noted in 9 cases, including 7 cases of the nonbasal tumor and 2 cases of basal one. The indications and efficacy of gamma knife treatment of the meningioma were discussed. Our preliminary experience suggests that gamma knife is an effective and safe technique for carefully selected patients with meningiomas.

Adult↗
PubMed1998

[Investigation of the Zeta reference values by Chinese-built Zetafuge and preliminary application].

We determined the Zeta sedimentation ratio (ZSR) for 326 normal subjects and 106 inpatients by Chinese-built Zetafuge. The mean ZSR for normal subjces was 52.5 +/- 5.05% and that for inpatients 68.52 +/- 5.54% (P < 0.001). ZSR can be determined by using directly the blood sample with the anticoagulant EDTA-K2; the determination is faster and requires less volume of blood sample; it is not affected by anemia and need not be corrected for age and sex. The results of ZSR are expressed in a new unit, %, not in mm/h. The reference value we established is: < or = 62%. We also discussed the problem of reproducibility, the speed of centrifuge, the height of blood, and compared this method with the westergren method. The agreement between the two methods is 86.6%.

Adult↗
PubMed1998

[Distribution of K5, K10 in transgenic mouse with lac Z reporter gene].

OBJECTIVE: To detect the distribution of K5, K10 in live mouse. METHODS: lacZ gene, which encodes beta-galactosidase, as a reporter gene, bovine K5, K10 as promoter, containing Sal I fragment, was inserted into the Sal I sites of PLGZ and PLBS-2, respectively. The constructs were microinjected into the mice fertilized eggs, and then PCR positive ones were kept. The next generations could be used for experiments. Frozen sections of transgenic mice skin, tail were stained with 0.1% X-gal solution at 37 degrees C overnight and counterstained with nuclear fast red. RESULT: In sguamous epidermis, K5 was distributed in basal and outer root sheath, K10 in suprabasal and inner root sheath. K5 and K10 were also distributed in some other organs except heart. No K5 was seen in the brain. CONCLUSION: lacZ transgenic animal is helpful in the study of gene mutation and treatment. The recognition of K5 and K10 distribution could be a primary step to probe the mechanism of some related diseases and cancers.

Animals↗
PubMed1998

[Simultaneous determination of creatinine, pseudouridine and uric acid in serum and urine by high performance liquid chromatography].

In this paper a sensitive, rapid and simple HPLC method for the simultaneous determination of creatinine (Cr), pseudouridine (Pu) and uric acid(UA) has been established. We have evaluated clinical value of the method in the early diagnosis of diabetic nephropathy (DN). Separation was obtained using Shim-pack CLC-ODS 15 x 0.6 cm column and mobile phase of buffer solution of phosphate (pH 3.0, 0.02 mol/L) with flow rate of 1 mL/min. Detection was performed with UV detector at an automatic adjustment of wavelength. The recoveries of Cr, Pu and UA were 101.4%, 104.9% and 105.0% respectively. The calibration curves were linear within the concentration range of 8.6-274.6 mumol/L for Cr, 0.72-22.93 mumol/L for Pu and 19.1-612.7 mumol/L for UA (n = 6, r > 0.999, p < 0.01). The CV for within day and between day measurements were < 2.5% and < 5.0% respectively. In addition, Pu, Cr and UA were simultaneously determined in serum and urine of 39 patients with diabetic mellitus (DM). 15 patients with nephrotic syndrome (NS) and 53 normal subjects by the method. Results include: 1. the levels of serum Pu in all DM patients (100%) with microalbuminuria (MiAU) and macroalbuminuria (MaAU) were greater than maximum of normal subjects (X + 2S). In addition, in 9 DM patients (41%) with normal albuminuria (NAU) the levels were also greater than the maximum. 2. In patients with DM, there was no correlation between the serum Pu and the urinary albumin excretion (UAE), whereas the serum Pu correlated closely with the serum Cr. However, the incidence for serum Pu increase was significantly greater in patients. 3. The levels of serum Pu in patients with NS were greater than those in control subjects and patients with DM. Conclusion is that the determination of serum Pu could be used as sensitivity index for the early diagnosis of DN.

Chromatography, High Pressure Liquid↗