Biomedical subjects

Z Peng

Publications and source records attributed to Z Peng.

At least 19 recordsLinked to original sources

PubMed1996

Cross-reactivity and molecular mass of the epsilon chains of the IgE antibodies in dogs, humans, rats, and mice.

We report the cross-reactivities and comparative molecular masses of the IgE epsilon chains in humans, rats, mice, and dogs. Monoclonal human, rat, and mouse IgE, and our purified polyclonal dog IgE were used in the study. IgE of the 4 species, separated by SDS-PAGE, were analyzed by immunoblotting with polyclonal and monoclonal antihuman IgE, polyclonal and monoclonal antimouse IgE, monoclonal antirat IgE, and polyclonal antidog IgE antibodies. The polyclonal antihuman and polyclonal antimouse IgE cross-reacted with the IgE of the other 3 species, while their monoclonal forms cross-reacted with dog IgE only. Polyclonal antidog IgE cross-reacted with human and mouse IgE, while the monoclonal antirat IgE did not cross-react with any other species. "Reverse' passive cutaneous anaphylaxis in ragweed-sensitized dogs revealed that polyclonal antihuman and polyclonal antimouse IgE were able to elicit positive skin responses, and monoclonal antihuman, antirat, and antimouse IgE antibodies were not. The molecular masses of the epsilon chains were 77 kDa for mice, 75 kDa for rats and dogs, and 70 kDa for humans.

Animals↗

PubMed1996

Immunoblot analysis of IgE and IgG binding antigens in extracts of mosquitos Aedes vexans, Culex tarsalis and Culiseta inornata.

Extracts of one globally distributed mosquito species (Aedes vexans) and two North American species (Culex tarsalis and Culiseta inornata) were prepared from heads and thoraxes. Proteins of the three extracts were separated by 12% SDS-PAGE and transferred to nitrocellulose membranes for immunoblotting. Immunoblotting was completed by sequential incubations of the membranes with a pooled human serum from subjects allergic to mosquito bites, monoclonal antibodies to human IgE or IgG, and goat antimouse IgG conjugate. Twelve to sixteen antigens with molecular masses ranging from 18.5 to 160 kDa were found in each extract. Nine antigens were shared by 3 species and 6 were shared by 2 species. Only 3 were species-unique. Most antigens bound to both IgE and IgG antibodies. IgE and IgG antibodies against A. vexans were studied by immunoblotting using individual serum from subjects with or without skin reactions to A. vexans bites. All 3 subjects with severe skin reactions had strong IgE and IgG antibodies to 32.5, 40, and 50 kDa proteins. The patterns and magnitudes of IgE and IgG antibodies to the antigens varied among individuals. Very faint IgE antibodies to these antigens were found in the 2 subjects with no skin reactions, suggesting that IgE plays a role in the development of mosquito allergy.

Aedes↗

PubMed1995

A rice HAL2-like gene encodes a Ca(2+)-sensitive 3'(2'),5'-diphosphonucleoside 3'(2')-phosphohydrolase and complements yeast met22 and Escherichia coli cysQ mutations.

A plant homolog of yeast HAL2 gene (RHL) was cloned from rice (Orizya sativa L.). The RHL cDNA complemented an Escherichia coli cysteine auxotrophic mutant, cysQ, and the yeast HAL2 mutant, met22. The latter is a methionine auxotroph and cannot use sulfate, sulfite, or sulfide as sulfur sources but exhibits wild-type activities of the enzymes necessary to assimilate sulfate and has normal sulfur uptake system. These results demonstrated that HAL2, cysQ, and RHL genes encode proteins with similar function in sulfur assimilatory pathway. The RHL cDNA expressed a 40-kDa protein that was shown to catalyze the conversion of adenosine 3'-phosphate 5'-phosphosulfate (PAPS) to adenosine 5'-phosphosulfate (APS) and 3'(2')-phosphoadenosine 5'-phosphate (PAP) to AMP. The enzyme activity is Mg(2+)-dependent, sensitive to Ca2+, Li+, and Na+ and activated by K+. The inhibition by Ca2+ depends on the Mg2+/Ca2+ ratio and is reversible by high Mg2+ concentration. The substrate specificity and kinetics of RHL enzyme are very similar to the Chlorella 3'(2'),5'-diphosphonucleoside 3'(2')-phosphohydrolase (DPNPase). Our evidence suggests that this enzyme regulates the flux of sulfur in the sulfur-activation pathway by converting PAPS to APS. Several residues that are essential for the activity of this enzyme were identified by site-directed mutagenesis, and the possible role of DPNPase in salt tolerance is discussed.

Adenosine Phosphosulfate↗

PubMed1995

Doppler echocardiographic characteristics of sinus of valsalva aneurysms.

This study evaluated the efficacy of a comprehensive transthoracic Doppler echocardiographic examination for correct detection of SVA and its associated lesions of VSD and aortic insufficiency. A consecutive series of 36 patients was obtained; all had surgical confirmation of the anatomic defects. The location of the SVA was correctly determined in 97% of patients, and the associated presence of a VSD was correctly determined in 79% of the studies. In the cases in which Doppler was available, all 11 patients with associated aortic insufficiency were detected. In this series 32 patients had right SVA, 3 had noncoronary sinus SVA, and 1 had a left SVA. Relative frequency of the rupture site location corresponded closely to that in previous necropsy studies. It is concluded that transthoracic Doppler echocardiography can correctly localize SVAs and most associated lesions.

Adult↗

PubMed1995

Identification of a dog IgD-like molecule by a monoclonal antibody.

IgD has not been identified in dogs. We produced a monoclonal antibody (mAb) designated 9B during the production of hybridomas to dog IgE. Using Western blot analysis under non-reducing conditions, the mAb (9B) recognized a predominant protein band of 185 kDa which was also recognized by anti-dog IgG F(ab')2, suggesting that this 185 kDa protein is an immunoglobulin (Ig) containing light chains. Under reducing conditions, the mAb (9B) recognized only one protein band of 55 kDa which presented a distinct molecular weight (MW) and immunoreactivity from the dog tau, mu, alpha, and epsilon chains. The 55 kDa band did not react with anti-dog IgE, IgM, IgA, and IgG, but did react with the mAb (9B). The MW was 75 kDa for the epsilon chain, 77.5 kDa for the mu chain, 58 kDa for the alpha chain, and 52 kDa for the tau chain. Further, by immunofluorescent staining, this Ig recognized by the mAb (9B) was found on the surface of dog lymphocytes. Studies of this dog Ig with the mAb revealed that this Ig bound to protein A and protein G-Sepharose, and that its enzyme-linked immunosorbent assay (ELISA) activity as measured by the mAb (9B) did not change after heating at 56 degrees C for 2 h. Ragweed-specific IgG, IgE, and this newly defined Ig significantly increased when dogs were immunized with ragweed extract. These data suggest that this Ig is a previously unrecognized IgD-like molecule in dogs.

Allergens↗

PubMed1995

A novel amber mutation in a beta zero-thalassaemia gene (beta 37TGG-->TAG), with direct detection by mapping the restriction fragments in amplified genomic DNA.

A novel amber mutation, a G to A substitution at the second position of codon 37 in the beta-globin gene that changes the tryptophan coding triplet (TGG) to a termination codon (TAG), was found in a Chinese beta-thalassaemia carrier. The mutant gene creates an additional Dde I recognition site and eliminates the Ava II site, so this point mutation can be directly identified by restriction enzyme analysis.

Adult↗

PubMed1995

Applicability of prostaglandin E1 indirect portal vein angiography in patients with portal hypertension.

The imaging quality of the portal vein was obviously improved with prostaglandin E1 (PGE1) indirect portal vein digital subtraction angiography (DSA) in 23 cases. The time-density curve showed that the occurrence rate of opposite hepatic blood flow of splenic vein (SV) was the highest (17.4%). The total visualization rate of the left gastric vein (LGV) was 78.3%, and the visualization rate of the short gastric vein (SGV) was 36.4%. 38.9% of the LGV and all the SGV were visualized with indirect portal vein DSA through SA. Indirect portal vein angiography through superior mesenteric artery and that through splenic artery were of equal importance. In portal hypertension patients with hemorrhage of the digestive tract, when LGV and SGV could not be visualized in PGE1 indirect portal vein DSA, the possibility of non-varices vein bleeding should be considered. When opposite hepatic blood flow with obvious dilation appeared in LGV and SGV, devascularization of the pericardial blood vessels would be justifiable.

Adult↗

PubMed1995

[Protective effect of semen Ziziphi spinosae on superoxide dismutase reduction in mice with endotoxin fever].

An animal model with decreasing SOD was established by fever from intravenous injection of endotoxin. The SOD level was measured by RIA in the animal serum and liver tissues. The results indicated that the SOD level of the model group was obviously lower than that of the normal group (P < 0.05), but the level of the group treated with Semen Ziziphi Spinosae was higher than that of the model group. The study shows that Semen Ziziphi Spinosae can protect mice with endotoxin fever from SOD decrease.

Animals↗

PubMed1995

[Clinical evaluation of the vulva reconstruction with myocutaneous flap transposition after radical vulvectomy].

Thirty-three cases with carcinoma of vulva were treated in the division of gynecologic oncology from July, 1989 to April, 1994. Out of 33 cases, 18 with stage II or III underwent radical vulvectomy, pelvic and inguinal lymphadenectomy. These were divided into 3 groups based on the different methods of vulval reconstruction: (1) simple suture group (6 cases); (2) cutaneous flap group (4 cases); (3) myocutaneous flap transposition group (8 cases). The large defect area left by radical vulvectomy and inguinal lymphadenectomy was reconstructed by myocutaneous flap, tensor fascia latae flap, in 6 cases and musculus gracilis myocutaneous flap in 2 cases. All the cases in group 1, 2 suffered from breakdown of wounds, infection or necrosis, resulting in long term hospitalization (mean duration 36.3 days), delayed scar pains, and problems in walking or sexual activity. Primary wound-healing was observed in the 6 cases of group 3, wound infection occurred in one case with diabetes and one case of relapse cancer after radiation therapy. The mean duration of hospitalization in group 3 was 20 days, and neither scar pains nor problems in sexual activity was found after a follow up of 6 months to 4 years. One case in this group died of brain metastases of cancer of vulva. The indications and advantages of myocutaneous flap transposition are discussed. It is suggested that myocutaneous flap transposition surgery is clinically one of the best and safest methods for reconstruction of the vulva and it can improve the quality of life.

Adult↗

PubMed1995

[Epidemiologic studies on three episodes of acute bacillary dysentery outbreak].

Three episodes of illness outbreak, with major symptoms of acute abdominal pain and diarrhea, occurred in 1990 to 1991 in the army forces stationed in Beijing. Bacillary dysentery outbreak caused by Shigella dysentariae were confirmed with epidemiological investigations and pathogen identification. Drug sensitivity tests with Kirby-Bauer method for the strain isolated showed it had obvious resistance to 13 of 14 kinds of antibiotics tested. Detection of plasmid with Birnboim method showed most of the strains had R-plasmid of 120-140 Md and few had small plasmid. It suggested inherent connection between drug-resistance of the strains and plasmid.

China↗

PubMed1995

Measurement of mosquito Aedes vexans salivary gland-specific IgE and IgG antibodies and the distribution of these antibodies in human sera.

BACKGROUND: Lack of sensitive, reproducible, and specific immunoassays has hampered the evaluation and immunotherapy of mosquito allergy. OBJECTIVE: We wanted to develop ELISAs for measurement of mosquito-specific IgE and IgG using salivary glands from the mosquito Aedes vexans. METHODS: Microplates coated with the salivary gland antigen were sequentially incubated with serum samples or reference serum, goat antibody to human IgE or IgG, and enzyme-conjugated rabbit anti-goat IgG. RESULTS: The specificity of the assays was demonstrated by the successful inhibition of the ELISA reactions with the mosquito antigens. Reproducible results were obtained; mean coefficients of variation between assays were 0.200 +/- 0.002 for the IgE measurement and 0.114 +/- 0.001 for the IgG measurement. The sensitivity of each assay was 0.39 U/mL. Using these assays, sera from 50 subjects with skin reactions to mosquito bites ranging from negative to strongly positive were analyzed for mosquito-specific IgE and IgG. The mean mosquito-specific IgE and IgG were significantly higher in subjects with skin reactions to mosquito bites than in those without skin reactions (P < .005), higher in females than males (P < .031), and slightly higher in atopics than nonatopics (P > .05). Also, there was a significant correlation between mosquito-specific IgE and IgG levels (r = .77, P < .001). CONCLUSIONS: Specific, reproducible, and sensitive ELISAs have been developed for measurement of antibodies to Aedes vexans. Mosquito-specific IgE and IgG may involved in the development of sensitivity to mosquito bites.

Aedes↗

PubMed1995

Synthesis and evaluation of a new bifunctional chelating agent for the preparation of radioimmunoconjugates.

The conjugation of radiometals to monoclonal antibodies results in agents for radioimmunoimaging and other medical applications. Due to remarkable ability to form stable metal complexes with a great number of metal ions in different oxidation states, polyaminocarboxylate chelates are useful tools for this purpose. Bifunctional chelators that can hold radiometals with high stability under physiological conditions are essential to avoid radiation damage to non-target organs. We have synthesized a new bifunctional chelate 2-(p-aminobenzyl)-1,3-propylenediamine-N,N,N',N'-tetraacetic acid by a simple method and studied the rate of loss of radioactivity from the radiolabeled (111In, 90Y) chelates to serum proteins in human serum at 37 degrees C. The relative stability constant of this new bifunctional chelate was found to be very similar to the underivated form. This chelate was conjugated to murine monoclonal antibody (B43) and immunoreactivity of the conjugated was determined by competitive binding analysis, which showed no significant change in its immunological activity. Biodistribution of the 111In radioconjugate was examined in conventional Balb/c and tumor-bearing (-OVCAR-3) athymic Balb/c mice.

Aniline Compounds↗

PubMed1994

Exercise can provide protection against bone loss and prevent the decrease in mechanical strength of femoral neck in ovariectomized rats.

The effect of treadmill exercise on bone loss in ovariectomized (OVX) rats was studied in two different sets of experiments. In the first experiment rats were either ovariectomized (n = 38) or sham operated (n = 18) at the age of 12 weeks. Half the OVX rats were trained twice a day for 30 minutes by running at 10 m/minute for 7 or 17 weeks. In the second experiment 40 female rats, aged 12 weeks, were divided into five groups (n = 8). One group of rats was sacrificed on day 0 for the baseline data. Other rats were sham operated or ovariectomized for 9 weeks. Half of both groups were trained using the same training program as in the first experiment. OVX reduced trabecular bone volume (TBV) in the distal femur to 42.7 and 48.3% in 8 and 18 weeks, respectively. Exercise opposed this effect significantly but could not prevent it totally. Exercise did not have any significant effect on sham-operated animals. OVX induced a 17.7 and 30.7% decrease in maximal failure load of femoral neck in 8 and 18 weeks, respectively. A corresponding decrease was also observed in the torque capacity of tibia. Exercise was able to prevent almost totally the decrease in bone strength of femoral neck, tibia, and humerus. In conclusion, our results suggest that the measurement of bone strength in aging female rat femoral neck can be used as a useful indicator of the deleterious effect of OVX in bone. These results further indicate that exercise can overcome a significant part of the decrease in trabecular bone volume and maintain the mechanical strength of femoral neck and tibial shaft in the OVX rats.

Analysis of Variance↗

PubMed1994

Effect of running exercise on the bone loss induced by orchidectomy in the rat.

The effect of exercise on castration-induced osteoporosis in 3-month-old male rats weighing 264 +/- 4 g at the beginning of the experiment was studied. A testosterone deficiency was induced by orchidectomy (ORC), and the exercise group ran 10 m/minute for 1 hour a day on a treadmill at 0% grade. There were seven groups of eight rats (n = 56) randomized into a control group killed at time 0, and sham, ORC and ORC and exercise groups killed at 4 and 8 weeks. ORC reduced body weight gain (with analysis of variance (ANOVA) P < 0.001), and at 4 weeks the body weight was 343 +/- 14 g in ORC group and 301 +/- 4 g in the ORC and exercise group (P < 0.01). The increase in femoral length was slower in the ORC+exercise groups. The ash weight of the tibia did not decrease significantly after ORC or ORC+exercise. ORC did not affect 45Ca incorporation, but exercise slightly increased it in the whole tibia 8 weeks after ORC (with ANOVA P = 0.057). ORC had significantly lowered the trabecular bone volume in the secondary spongiosa of the distal femur at 4 and 8 weeks, and exercise did not prevent this. This is an opposite finding to our previous study with ovariectomized female rats [12]. ORC also significantly had reduced the osteoblast-lined trabecular bone surface and the number of osteoclasts by 8 weeks after the operation. Exercise increased the osteoblast-lined surface and the number of osteoclasts.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗

PubMed1994

Occupational allergy after exposure to caddis flies at a hydroelectric power plant.

A cross sectional survey was conducted in a hydroelectric power plant in which the workforce was exposed to large numbers of caddis flies. 28 of 57 employees participated. About 50% of the participants reported work related eye, nose, and sinus symptoms and wheezing. Working in locations with greater exposure to caddis flies was significantly associated with work related symptoms. 17 workers (61%) were skin prick positive to a laboratory prepared caddis fly antigen (LCFA) made from the remains of caddis flies present in the plant and 11 (39%) had positive reactions to a commercial caddis fly antigen (CCFA). Workers stationed in heavily exposed areas were 3.7 times as likely to have a positive response to the LCFA (p = 0.009) and 5.3 times as likely to have a positive response to the CCFA (p = 0.036). 13 (46%) of survey respondents reported three or more work related symptoms. 10 (91%) CCFA positive workers reported three or more work related symptoms. Pulmonary function studies revealed slight, but not significantly decreased forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and FEV1/FVC ratios in workers who were skin test positive to either caddis fly preparation when compared with those who were negative. One worker who was skin test positive to both antigens had a cross shift fall in FEV1 of 20% predicted. Occupational allergy to caddis flies proved to be a significant health problem at this work site.

Adult↗

PubMed1994

Binding properties of protein A and protein G for human IgE.

We studied the binding of protein A and protein G to human monoclonal and polyclonal IgE. An ELISA was used to measure human IgE. Protein A-Sepharose did not bind to monoclonal IgE, but bound to 12-14% of serum polyclonal IgE and to -3% of the polyclonal IgE purified from the serum. No difference in binding to protein A was found between IgE from an allergic patient and that from a non-allergic subject. Protein G bound to neither polyclonal IgE nor monoclonal IgE. Thus, protein G is better than protein A with respect to separation of IgE from IgG.

Humans↗

PubMed1994

Antitumor activity of immunoconjugates composed of boanmycin and monoclonal antibody.

Boanmycin (bleomycin A6, BM), an antitumor antibiotic, was conjugated to monoclonal antibodies including R19, H111 and CCT2. The immunoconjugates exhibited selective cytotoxicity to related target cells including cecum cancer Hce-8693 cells, liver cancer BEL-7402 cells and leukemia CEM cells. They were highly effective against related human tumor xenografts in nude mice, and the inhibition rates by the conjugates were much higher than those by free BM. The inhibition rate by R19-BM conjugate against human cecum cancer xenografts reached 90%. BY immunoelectron microscopy, CCT2-BM conjugate showed specific binding and internalization in leukemia CEM cells. The results indicate that boanmycin-monoclonal antibody immunoconjugates are highly active both in vitro and in vivo.

Adenocarcinoma↗

PubMed1994

The sex ratio of suicide rates in China.

Suicide is the leading cause of non-natural deaths in China. Female suicide rates are higher than male rates, and the rural suicide rate is 2.8 times higher than the urban rate. In 16,568 cases of suicide, the male to female ratios observed were 0.92 and 0.81 in urban and rural areas, respectively. The male to female ratio of the suicide rates in China is close to that of other Asian countries (1.2-1.5), but much lower than that in 26 European countries. In about two-thirds of all suicides, family disputes and love disappointments are the precipitants. The higher rate of suicide among women probably reflects the fact that Chinese women are of low social and economic position, and have few social resources to protect them, especially in remote areas.

Cause of Death↗