Superconducting, metallic, and insulating phases in a model of CuO2 layers.
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Journal Article↗
Biomedical subjects
J Ye
Publications and source records attributed to J Ye.
Long-term high-titer neutralizing activity induced by octameric synthetic HIV-1 antigen.
A titer for homologous viral neutralization activity (greater than 1:19,683) was observed after a 3.5-year immunization period with an octameric, branching peptide representing the principal neutralizing determinant (PND) of the human immunodeficiency virus-1IIIB envelope protein. Booster immunizations elicited persistent and potent antibodies in guinea pigs, exceeding responses produced by a conventional bovine serum albumin conjugate by 100-fold. Peptide length, central presentation of a conserved sequence, and inclusion of an upstream sequence contributed to immunogenicity. Titers (greater than 1:1,000) of heterotypic neutralizing antibodies also developed. Octameric PND peptides are a promising approach for an acquired immunodeficiency syndrome (AIDS) vaccine.
AIDS Vaccines↗
Improved serodiagnosis of hepatitis C virus infection with synthetic peptide antigen from capsid protein.
Cloning and expression of hepatitis C virus have allowed the development of immunoassays to detect hepatitis C virus infection. However, currently available recombinant fusion protein C100-3 assays, based on a nonstructural protein of the virus, are limited in sensitivity, particularly for detecting acute infection. In this report seroconversion panels showed that an assay based on synthetic peptides, derived from immunodominant regions of both capsid and nonstructural proteins, accelerated hepatitis C virus antibody detection by 4-10 weeks. In screening, this enzyme immunoassay increased detection from 47% to 64% in plasmapheresis donors with elevated alanine aminotransferase levels (greater than 100 international units per liter), from 15% to 24% in anti-hepatitis B core antigen-positive blood donors, and from 28% to 42% in renal dialysis patients when compared with nonstructural peptide-based assays. The screening assay was repeatedly reactive for 27 of 2902 volunteer blood donor samples (0.93%); four sera reacted only with the capsid antigen. The peptide test distinguished true from false positive results in agreement with recombinant immunoblot assay in 96% of blood donor samples repeatably reactive on a recombinant hepatitis C virus enzyme immunoassay.
Animals↗
Bioactivity of plasma prolactin in ovariectomized, diethylstilbestrol-treated Long-Evans and Holtzman rats after thyrotropin-releasing hormone or bromocriptine administration.
The objective of this study was to determine the effects of thyrotropin-releasing hormone (TRH) and bromocriptine on plasma levels of biologically active prolactin in ovariectomized, diethylstilbestrol (DES)-treated rats. Female Long-Evans and Holtzman rats were ovariectomized and each was given a subcutaneous implant of diethylstilbestrol (DES). One week later, groups of DES-treated rats were fitted with indwelling intra-atrial catheters, and 2 days later blood samples were withdrawn before and at 1, 2, 5, 10, and 20 min after intravenous administration of TRH (250, 500, or 1000 ng/rat). Blood samples were obtained from other groups at 4 weeks of DES treatment by orbital sinus puncture under ether anesthesia before and at 30, 60, and 120 min after bromocriptine administration (2.5 mg/rat sc). Plasma was assayed for prolactin by conventional radioimmunoassay (RIA) and by Nb2 lymphoma bioassay (BA). Holtzman rats released significantly more prolactin following TRH than did Long-Evans rats when the RIA was used to measure prolactin. However, when the BA was used to assay prolactin in the same samples, the Long-Evans rats released more prolactin than did the Holtzman rats. In addition, the ratio of the BA to RIA values was significantly increased in both strains following TRH, but the greatest increase was observed in the Long-Evans rats, in which the ratio was 4.5 at the peak of the TRH-induced rise in plasma prolactin. Gel filtration chromatography of plasma obtained at 5 min after TRH treatment in Long-Evans rats revealed large molecular forms of prolactin with BA to RIA ratios of 4-5. In addition, monomeric prolactin had a BA to RIA ratio of 2. Bromocriptine treatment reduced prolactin levels in both strains, but the effect was more rapid in Holtzman than in Long-Evans rats. In addition, bromocriptine treatment of Holtzman, but not Long-Evans, rats significantly reduced the BA to RIA ratio of plasma prolactin. The results indicate that TRH and bromocriptine affect the release of biologically active prolactin to a greater extent than prolactin detected by antibody in the RIA, and that Long-Evans and Holtzman rats respond to these secretagogues differently with regard to BA to RIA comparisons.
Animals↗
A comparison of plasma prolactin levels in young female Long-Evans and Holtzman rats as measured by Nb2 lymphoma bioassay and radioimmunoassay.
This study was conducted to determine the plasma levels of prolactin in prepubertal and young, postpubertal, proestrus rats of mammary tumor-susceptible (Sprague-Dawley) and tumor-resistant (Long-Evans) strains using a sensitive bioassay-Nb2 lymphoma cell replication. Prepubertal Long-Evans rats had significantly higher levels of prolactin than did Holtzman Sprague-Dawley rats of the same age. Likewise, Long-Evans rats secreted significantly more prolactin into the blood on the afternoon and evening of proestrus than did Holtzman rats. Finally, ovariectomized Long-Evans rats released more prolactin into the blood at 1 day, but not at 8 or 15 days, of treatment with diethylstilbestrol. Prolactin levels determined by conventional radioimmunoassay and by bioassay were similar except on the afternoon of proestrus, when, in both strains of rats, the bioassay to radioimmunoassay ratio increased significantly above 1.0 during the late evening. In addition, the ratio was significantly less than 1.0 in the early and late afternoon in the Holtzman rats, but not Long-Evans rats. These data indicate that a strain of rats that is resistant to experimentally induced mammary cancer has higher prolactin levels in the blood than does a strain that is susceptible to mammary cancer at a time when mammary gland growth is rapid. Furthermore, there are times during the proestrus prolactin surge when the bioassay yielded higher and lower values of prolactin than radioimmunoassay of the same samples, suggesting functional heterogeneity of prolactin that may impact on mammary gland or other target tissue function.
Animals↗
Electronic structures of FeB, Fe2B, and Fe3B compounds studied using first-principles spin-polarized calculations.
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Journal Article↗
Reduction of Chloroplast DNA Content in Solanum nigrum Suspension Cells by Treatment with Chloroplast DNA Synthesis Inhibitors.
Suspension cell cultures of Solanum nigrum were grown in the presence of six different chloroplast DNA synthesis inhibitors in order to determine whether the pool size of chloroplast DNA (cpDNA) could be selectively reduced relative to the nuclear DNA content. One of the effects of the inhibitors was a reduction in cell growth and viability. Cell growth (fresh weight) was reduced 50% (in 8 day cultures) by: 100 micromolar bisbenzimide, 8 micromolar ethidium bromide, 0.3 micromolar 5-fluordeoxyuridine (Fudr), 200 micromolar nalidixic acid, 30 micromolar novobiocin, or 10 micrograms per milliliter rifampicin. At these concentrations, three of the inhibitors, ethidium bromide, Fudr, and rifampicin, also substantially reduced the viability of the cultures. Analyses of the chloroplast and nuclear DNA content per gram fresh weight by dot blot hybridizations indicated that the reduction of cpDNA content was greatest at inhibitor concentrations which reduced cell growth by more than 50% but this depended on the culture conditions. For example, the two DNA gyrase inhibitors, nalidixic acid and novobiocin, were more effective in lowering cpDNA content in cultures which were transferred (2 x 4 days) once during the eight day incubation. Because several inhibitors were toxic to cell growth, the DNA content of treated cells was also determined on the basis of cell (protoplasts) number. Analyses of nuclear and cpDNA content per cell for each treatment indicated that only the DNA gyrase inhibitors, nalidixic acid, and novobiocin reduced cpDNA content. Neither inhibitor reduced nuclear DNA content. These results suggest that DNA gyrases participate in cpDNA replication. The selective reduction of cpDNA content in regeneratable cultures may facilitate the generation and selection of cpDNA mutants or transformants from higher plants.
Journal Article↗
Prognostic significance of general immune competence in acute leukemia.
The prognostic significance of lymphocyte transformation rate, E-RFC%, 29 degrees C E-RFC%, serum IgG, IgA, IgM and C3 levels were studied in 286 patients with acute leukemia. In acute lymphoblastic leukemia (ALL), the pretreatment immunological parameters were not related to whether the patients could achieve complete remission (CR), but the patients with E-RFC% greater than 30% before treatment or E-RFC% restored to normal after treatment had a significantly longer survival time. In acute nonlymphocytic leukemia (ANLL), pretreatment LTR and E-RFC% were significantly higher in patients who could achieve CR subsequently, the patients with higher pretreatment levels of LTR, E-RFC% or 29 degrees C E-RFC% survived significantly longer than patients with lower levels of these parameters, and the patients whose LTR could return to normal after treatment had a significantly higher CR rate and longer survival times. Except that the pretreatment IgM level was related to the survival of ANLL patients, serum levels of immunoglobulins and C3 had no prognostic value for both ALL and ANLL. In both ALL and ANLL, the immunological parameters changed significantly when relapse occurred.
Adolescent↗
The effects of radiotherapy on the immune system of patients with nasopharyngeal carcinoma.
We report on 123 patients with nasopharyngeal carcinoma whose immune status was measured at the time of diagnosis, the day radiotherapy was completed, and then 2-3 months and 6-8 months after completion of radiotherapy. Immunological tests performed included the lymphocyte transformation test, the erythrocyte-rosette formation test (ERFT), the 29 degrees C erythrocyte-rosette formation test (29 degrees C ERFT), lymphocyte counts (lymphocytes/mm3 and percentage of lymphocytes), levels of serum immunoglobulins (IgG, IgA, IgM), complement (C3) and circulating immune complexes (CIC), the antinuclear antibody test and a skin test using phytohaemagglutinin (PHA). There were statistically significant differences in all tests (except C3) between patients and normal controls. Marked differences were seen in the lymphocyte count, ERFT, and 29 degrees C ERFT after radiotherapy (p less than 0.01). The diameters of induration of the PHA skin tests were less than those before radiotherapy (p less than 0.01). There were higher incidences of recurrence and metastases in the patients with high levels of CIC and low numbers of lymphocytes in the peripheral blood after radiotherapy. Cellular immunity remained at a low level 8 months after radiotherapy.
Antibodies, Antinuclear↗
Synthetic peptide-based vaccine and diagnostic system for effective control of FMD.
We have designed synthetic peptides corresponding to two different regions of the genome of foot-and-mouth disease virus (FMDV) that are effective as (a) a vaccine or (b) a diagnostic reagent which differentiates convalescent from vaccinated animals, respectively. The peptide vaccine is based on a sequence from the prominent G-H loop of VP1, one of the four capsid proteins. The sequence was optimized by the inclusion of a cyclic constraint and adjoining sequences, and broader immunogenicity was obtained by the incorporation of consensus residues at hypervariable positions. The peptide also included a promiscuous T-helper epitope for effective immunogenicity in outbred populations of large animals.The diagnostic reagent, a peptide based on non-structural (NS) protein 3B, is used in immuno-assays for the detection of antibodies. Antibodies to this NS protein are present in the sera of infected animals but not in the sera of vaccinated animals. The VP1 peptide can be used in complementary immuno-assays for confirmation of NS test results and to monitor for vaccination. This system for differential diagnosis is important to establish the disease-free status of a country.
Amino Acid Sequence↗
The dynamic gene expression from different genetic systems for protein and lysine contents of indica rice.
The dynamic expression of genes for protein and lysine contents of rice grain under different environments was carried out with time-dependent measures by using the developmental genetic models for quantitative traits of triploid endosperm in cereal crops. The results showed that the genetic effects, especially genotype x environment (GE) interaction effects from the genes expression of different genetic systems including triploid endosperm, cytoplasm and diploid maternal plant were important for the performance of both nutrient quality traits at all developmental times/stages of rice grain. The conditional genetic variance analysis found that the activation of quantitative genes especially from endosperm and maternal plant genetic systems for protein and lysine contents was gradually carried through the developmental process of rice grain. The net genetic effects showed that the new expression of quantitative genes for protein and lysine contents was more active at late filling stage (15-21 days after flowering) and maturity stage (22-28 days) of rice grain. Also the sequential expression of cytoplasmic genes cannot be ignorable for the development of nutrient quality traits. The phenomena that some genes could continuously express for several developmental stages or the genes expression could be interrupted among developmental stages of rice grain was detected especially for net endosperm additive main effects or maternal additive main effects. The differences of genetic relationships from different genetic systems were found for protein and lysine contents among developmental times of rice grain.
Diploidy↗
Regulation of carbohydrate transport in Lactococcus and Lactobacillus.
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Antigens, Bacterial↗
Surveillance for low-level malaria.
Due to good detection and control, malaria has reached very low levels in China with the result that existing methods of surveillance, taking blood slides from all fever cases and those with a common cold, are finding very few malaria cases among the millions of persons examined. Passive case detection agents in areas of moderate and low endemicity in Hubei Province, China, were instructed to indicate on the form associated with each slide whether the patient was considered to be a clinical case of malaria (group 1), was thought to have malaria but did not have all the features (group 2), had fever alone and was not thought to be a case of malaria (group 3), or merely had a common cold (group 4). In the low endemic area (slide positivity rate 0.23%), only 5 cases in group 3 and 4 in group 2 were detected per 10,000 examinations. It is recommended that these categories be discontinued in malarious areas of low endemicity, to encourage greater efficiency in detecting cases in groups 1 and 2. In the moderately endemic area, with a slide positivity rate of 4.19%, all categories, including group 4, were considered valuable for detecting malaria cases.
Adolescent↗
Phenotype and genotype variation in primary carnitine deficiency.
PURPOSE: Primary carnitine deficiency is an autosomal recessive disorder of fatty acid oxidation resulting from defective carnitine transport. This disease is caused by mutations in the carnitine transporter gene SLC22A5. The objective of this study was to extend mutational analysis to four additional families with this disorder and determine whether recurrent mutations could be found. METHODS: The SLC22A5 gene encoding the OCTN2 carnitine transporter was sequenced, and the missense mutations identified were expressed in Chinese hamster ovary (CHO) cells. RESULTS: DNA sequencing revealed four novel mutations (Y4X; dup 254-264, 133X; R19P; R399Q). Alleles introducing premature STOP codons reduced the levels of OCTN2 mRNA. Carnitine transport in CHO cells expressing the R19P and R399Q mutations was reduced to < 5% of normal. The 133X mutation was found in two unrelated European families. Two patients within the same family, both homozygous for the same mutation (R399Q) had completely different clinical presentation. CONCLUSIONS: Heterogeneous mutations in the SLC22A5 gene cause primary carnitine deficiency. Different presentations are observed even in children with identical mutations.
Animals↗
Circuit model-based analysis of the impedance rheopneumogram.
Impedance rheopneumography, like other applications of electrical bio-impedance, is receiving increasing attention as a simple, non-invasive tool for clinical diagnosis of the pulmonary circulation. However, one major drawback of this method lies in the difficulty in computing accurately the time domain parameters therefrom for diagnostic purposes. This paper presents a model-oriented analysis technique based on physiological consideration of both the arterial and venous pathways of the pulmonary circulatory system. The technique involves a combination of a two-segment model and a modified form of the 'Windkessel' model, the summed response of which is curve-fitted to measurement data via the non-linear method of Marquardt to obtain the system parameters. A simple illustrative application is also given to explain the changes in wave morphology for a subject under measurement in the supine and sit-up positions. The result suggests that this technique shows promise of providing useful physiological information and better insight of system behaviour than existing technique.
Algorithms↗