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Biomedical subjects

J Zhu

Publications and source records attributed to J Zhu.

At least 613 records · Page 34Linked to original sources
PubMed1996

Synthesis and antifungal activity of cinnamic acid esters.

Cinnamic, p-coumaric and ferulic acids were isolated from pineapple stems (Ananas comosus var. Cayenne). Twenty-four kinds of esters were prepared from these acids, alcohols and the components of Alpinia. Isopropyl 4-hydroxycinnamate (11) and butyl 4-hydroxycinnamate (12) were found to have almost the same effectiveness in antifungal activity against Pythium sp. at 10 ppm as that of the commercial fungicide iprobenfos (kitazin P).

Anti-Infective Agents↗
PubMed1996

Relationship between band sharing levels of DNA fingerprints and inbreeding coefficients and estimation of true inbreeding in turkey lines.

A regression analysis between band sharing of DNA fingerprints and calculated inbreeding coefficients was conducted using six experimental turkey lines. The DNA fingerprints were produced from 18 individual DNA samples per line representing different families. The DNA was digested with a HaeIII restriction enzyme and hybridized with Jeffreys' 33.6 probe. The band sharing within lines ranged from 0.42 to 0.62. The inbreeding coefficients of the lines were calculated based on population sizes and variation in family sizes. The inbreeding coefficients varied from 2.5 to 45%. Regression analysis between the two variables yielded a highly significant (P < or = 0.0001) linear model with a correlation coefficient of 0.992. The linear model was used to estimate the actual inbreeding in these lines.

Animals↗
PubMed1996

The influence of major histocompatibility complex genotypes on resistance to Pasteurella multocida and Newcastle disease virus in turkeys.

Sublines homozygous for each of four MHC haplotypes were developed from randombred control populations of turkeys and challenged with Pasteurella multocida (capsular serogroup a, somatic serotype 3, 4) at 6 wk of age or Newcastle disease virus (NDV; Texas GB strain) at 4 wk of age. In addition, individuals from a randombred control line (RBC2) and a subline (F) of RBC2 long-term selected for increased 16-wk BW were included in most of the challenge trials. The duration of the challenge trials was 2 wk for both organisms. Mortality following challenge with P. multocida or NDV was higher in the F line than in its randombred control. The MHC genotypes differed in mortality following exposure to both organisms but the rankings of the genotypes were not the same for P. multocida and NDV. The increased susceptibility of the F line to both organisms could not be explained by known changes in the frequency of the MHC haplotypes.

Animals↗
PubMed1996

Measurement of genetic parameters within and between turkey lines using DNA fingerprinting.

An experiment was conducted to estimate genetic parameters in six experimental and five commercial primary breeding turkey lines using DNA fingerprinting. Eighteen individual DNA samples per line were digested with an HaeIII restriction enzyme and hybridized with Jeffreys' 33.6 probe. The DNA fingerprints were analyzed with computer programs to measure band sharing (BS) and band frequencies. Within lines, BS ranged from 0.39 to 0.62 and reflected the history of the experimental lines. Among lines, BS ranged from 0.21 to 0.33 with an average of 0.26. The BS among the experimental lines reflected known relationships. All lines were subdivided based on indices of population subdivision. About 26 hypervariable loci were estimated from band frequencies. Average heterozygosity and genetic variability estimated from band frequencies were significantly different among lines and displayed a result very similar to the BS among lines. Genetic distance indices among lines were also significantly different and reflected known relationships between the experimental lines. The experimental selected lines displayed lower genetic diversity than did the other lines. The parameters measuring genetic diversity within lines had higher correlation coefficients among them than did the parameters between lines. The computer program used in this study made DNA fingerprinting easier to use in population analysis.

Animals↗
PubMed1996

Frequencies and genetic diversity of major histocompatibility complex class II haplotypes in commercial turkey lines.

The purpose of the present study was to estimate frequencies and diversity of MHC haplotypes in primary breeding lines of commercial turkeys. Restriction fragment length polymorphism analysis was used to assay MHC Class II haplotypes of blood samples from 11 primary breeding lines (comprised of both sire and dam lines) contributed by three major turkey breeding companies. Twenty-five blood samples obtained from wild turkeys were included for comparison. Seven haplotypes previously identified in experimental turkey lines were detected in the commercial lines. One haplotype, A, was predominant in all commercial lines with an average frequency of 76% and in the wild turkeys with a frequency of 46%. Diversity of MHC haplotypes was reduced in the commercial lines compared with the wild turkey. Seven commercial lines had no more than four haplotypes and loci in some lines were close to fixation. Haplotypic frequencies among sire and dam lines differed significantly, but genetic diversity was not different. Only Haplotype D was significantly more frequent in sire than in dam lines. The present data demonstrate that genetic diversity at MHC loci was low in commercial turkey lines.

Animal Husbandry↗
PubMed1996

Influence of growth selection in turkeys on resistance to Pasteurella multocida.

Four lines of turkeys, a randombred control (RBC2) started in 1966 and three sire lines (F, A, and B), were challenged with a field isolate of Pasteurella multocida (capsular serogroup A, somatic serotype 3, 4) at 6 wk of age. Line F, a subline of the RBC2 line, was selected for 28 generations for increased 16-wk BW and Lines A and B were primary breeding sire lines from two commercial breeders. Each bird was inoculated subcutaneously in the back of the neck with 1.2 x 10(7) washed bacteria. Mortality following challenge with P. multocida was higher in the sire lines (54 to 65%) than in the RBC2 line (26%). There was no significant difference in mortality among sire lines following challenge. These results suggest that the increased susceptibility to P. multocida in the F line in comparison to its control may be due to genetic changes resulting from selection for increased BW in this line.

Aging↗
PubMed1996

[Sixty years of society of medical history, Chinese Medical Association].

Being the earliest special Society under the CMA, the Society of Medical History was founded in 1935. The history of the 60 years since its establishment can be divided into 4 stages: the stage of foundation (1935-1952) in which solid works on academic exchanges, publications of monographs and Journal of Medical History, founding of museum and library, laid down the foundation for the later stages; the stage of continuous development (1952-1965) saw the moving of th Society office from Shanghai to Peking. The works in the 2 branch Societies in Peking and Shanghai were very active, with only little activity carried out at the national level; the third stage (1966-1979) was a stage of stagnation; the last stage (1979-1995) is a stage of rejuvenation and development. During this last stage, 8 national conferences, 1 international congress were sponsored, 16 local branches established, 500 members were included. Under the Society, there is a Head Group, under which there are 3 academic titles, viz. Society of Medical History, CMA, Group Membership of Chinese Association for History of Science and Technology, and Socieity of History of Chinese Medicine under the China Association of Traditional Chinese and Pharmacy.

China↗
PubMed1996

Pharmacokinetics and efficacy of low-dose all-trans retinoic acid in the treatment of acute promyelocytic leukemia.

A clinical trial was conducted in order to evaluate the therapeutic effect and side-effects of low-dose ATRA in the treatment of acute promyelocytic leukemia (APL). We compared the pharmacokinetic features in normal individuals with single oral ATRA at 15 mg/m2 and 45 mg/m2, respectively. The results showed that maximal plasma concentration (Cpmax) with oral 15 mg/m2 ATRA was high enough (10(-6) M) to induce APL cell differentiation. Based on these results, 27 cases of de novo APL patients were treated with continuous oral ATRA at the dose of 15-20 mg/m2/day and 24/26 evaluable cases (92%) achieved clinical CR after 13 to 67 days of ATRA treatment. No patient experienced RAS and DIC. The Cpmax with a single dose of ATRA on day 1 of treatment and immediately at CR obtained with continuous ATRA in three cases demonstrated similar values in one patient and an approximately two-fold decrease in two patients. More importantly, compared with a relatively well-matched historic group of 20 APL patients treated with high-dose ATRA, our results suggest that low-dose ATRA is as effective as high-dose in treating APL patients and may provide advantages through decreased hyperleukocytosis and other side-effects.

Administration, Oral↗
PubMed1996

[Analytic methods for seed models with genotype x environment interactions].

Genetic models with genotype effect (G) and genotype x environment interaction effect (GE) are proposed for analyzing generation means of seed quantitative traits in crops. The total genetic effect (G) is partitioned into seed direct genetic effect (G0), cytoplasm genetic of effect (C), and maternal plant genetic effect (Gm). Seed direct genetic effect (G0) can be further partitioned into direct additive (A) and direct dominance (D) genetic components. Maternal genetic effect (Gm) can also be partitioned into maternal additive (Am) and maternal dominance (Dm) genetic components. The total genotype x environment interaction effect (GE) can also be partitioned into direct genetic by environment interaction effect (G0E), cytoplasm genetic by environment interaction effect (CE), and maternal genetic by environment interaction effect (GmE). G0E can be partitioned into direct additive by environment interaction (AE) and direct dominance by environment interaction (DE) genetic components. GmE can also be partitioned into maternal additive by environment interaction (AmE) and maternal dominance by environment interaction (DmE) genetic components. Partitions of genetic components are listed for parent, F1, F2 and backcrosses. A set of parents, their reciprocal F1 and F2 seeds is applicable for efficient analysis of seed quantitative traits. MINQUE(0/1) method can be used for estimating variance and covariance components. Unbiased estimation for covariance components between two traits can also be obtained by the MINQUE(0/1) method. Random genetic effects in seed models are predictable by the Adjusted Unbiased Prediction (AUP) approach with MINQUE(0/1) method. The jackknife procedure is suggested for estimation of sampling variances of estimated variance and covariance components and of predicted genetic effects, which can be further used in a t-test for parameter. Unbiasedness and efficiency for estimating variance components and predicting genetic effects are tested by Monte Carlo simulations.

Genotype↗
PubMed1996

A continuous intracerebral gene delivery system for in vivo liposome-mediated gene therapy.

Using a minipump combined with stereotaxic techniques allows continuous delivery of therapeutic genetic materials into the brain. We investigated the therapeutic efficacy of liposome-mediated HSVtk gene transfer of experimental brain F98 glioma followed by treatment with ganciclovir. A single injection of DNA-liposome complexes showed a therapeutically significant decrease in the tumor volume. Continuous intracerebral delivery of DNA-liposome complexes using an osmotic minipump led to complete tumor regression in 36.4% of the treated animals. The safety and toxicity of this gene delivery system were also assessed. No organ pathology was observed in the experimental animals. The continuous gene delivery system could be a useful means of achieving higher doses with less toxicity and without the need for frequent injections.

Animals↗
PubMed1996

Activation of conventional mammalian protein kinase C isoforms expressed in budding yeast modulates the cell doubling time--a potential in vivo screen for protein kinase C activators.

Conventional mammalian protein kinase C (PKC) isoforms alpha, beta 1, and gamma were expressed in Saccharomyces cerevisiae and resulted in a differential increase in the yeast doubling time in response to distinct classes of PKC activators. Mutants were created in the regulatory domain of PKC alpha to map the interaction with the different activators. The macrocyclic lactone bryostatin 5 preferentially regulated PKC alpha activity through the second cysteine-rich sequence (CYS2) of Cl, while regulation by the diterpene ester mezerein displayed strong preference for the first cysteine-rich sequence (CYS1) of Cl. The phorbol esters phorbol-12-myristate-13-acetate (PMA) and 12-deoxyphorbol 13-phenylacetate 20-acetate (dPPA) regulated PKC enzymatic activity equally potently via CYS1 or CYS2 albeit at reduced levels compared with native PKC alpha. For the diterpene ester ingenol-3, 20-dibenzoate and the indol alkaloids (-)-7-octyl-indolactam V and (-)-indolactam V, no responses were observed for mutants lacking either CYS1 or CYS2 whereas native PKC alpha activity was regulated. These in vivo results were complemented by in vitro binding and catalytic assays which showed correlation between PKC enzymatic activity and the cell growth characteristics. The observed phenotype can be exploited to screen natural compounds in vivo for their PKC regulatory potential and to map the underlying interactions.

Animals↗
PubMed1996

Expression of biologically active human granulocyte-macrophage colony-stimulating factor in the silkworm (Bombyx mori).

Using virus derived from Bombyx mori (silkworm) nuclear polyhedrosis virus (BmNPV), we constructed an infectious recombinant virus carrying the human granulocyte-macrophage colony-stimulating factor (hGM-CSF) cDNA placed downstream from the polyhedrin promoter. The BmN cells infected with the recombinant baculovirus BmNPV-GM-CSF expressed recombinant (r)hGM-CSF up to 3.9 x 10(5) colony-formation units/ml in the medium. The maximum activity of rhGM-CSF was 4.3 x 10(6) colony-formation units/ml in the haemolymph of silkworm (Bombyx mori) larvae infected with BmNPV-GM-CSF. Three distinct species of GM-CSF of molecular masses 15, 18 and 20 kDa were detected by immunoblotting. The specific activity of rhGM-CSF purified from the haemolymph was up to 2.92 x 10(7) colony-formation units/mg. The isoelectric point of the purified rhGM-CSF was 5.5-5.7.

Animals↗
PubMed1996

Neurotrophic effects of Schwann cells in culture on spinal anterior horn neurons.

OBJECTIVE: To study the neurotrophic effects of Schwann cells in culture on damaged spinal anterior horn neurons. MATERIALS AND METHODS: Dissociated from rat sciatic nerves undergoing Wallerian degeneration by trypsin-collagenase. Schwann cells were cultured for 96 hours to form a trophoblast, onto which embryonic day 14 rat spinal anterior horn neurons plated on glass coverslip and cultured for 4 hours were transferred for cocultivation without cell-cell contact between Schwann cells and spinal anterior horn neurons. The effect of survival and neurite outgrowth activity promoting factors secreted from Schwann cells on spinal anterior horn neurons were examined under phase-contrast microscope at 24, 48, 72 and 96 hours after cocultivation. RESULTS: When cultured for 24 hours, almost all the spinal anterior horn neurons, that had been damaged in the course of dissociation from spinal nervous tubes, survived, and some of them grew with short neurites. 96 hours after cocultivation, about 1/3-1/2 of the neurons survived and their bodies enlarged with neurites by more than six times of their body diameters. Contrarily, none of the neurons in the control group (no Schwann cell trophoblast) survived simultaneously. CONCLUSIONS: By the model of Schwann cell-spinal anterior horn neuron cocultivation separated by glass coverslip, it was well confirmed that Schwann cell can secrete a neuron survival promoting factor and a neurite outgrowth promoting factor, which undoubtedly play a crucial role in peripheral nerve regeneration.

Animals↗
PubMed1996

[Epidemiology of gastroschisis in China].

OBJECTIVE: To study the clinical and epidemiologic characteristics of perinates with gastroschisis (GA) in China. METHODS: The birth defects monitoring program was undertaken in 945 hospitals from 29 provinces, cities and autonomous regions of China. Data about perinates including intrauterine death and stillbirth from 28 weeks of gestation to a period of 7 days after birth was collected through the medical records between October 1986 and September 1987. RESULTS: A total of 194 cases with GA was found in 1243284 perinates monitored. The incidence of GA in China varied from 0.4 to 3.4 with a mean of 1.6 per 10,000. The highest prevalence was in Shandong province (3.4/10,000) which was significantly higher than the average (P < 0.01). The prevalence of GA perinates with low birth weight was higher than that with normal birth weight (1.6 vs 0.6 per 10,000, P < 0.01), as well as that in the rural area higher than in the urban area (2.5 vs 1.1 per 10,000, P < 0.01). 70.6% of the cases with GA were accompanied with other major defects. The overall perinatal mortality rate (PMR) of GA was 91.8%. PMR of GA with other birth defects (95.6%) was significantly higher than that of GA only (82.5%, P < 0.01). Only 15% of GA were diagnosed before birth. CONCLUSIONS: GA was a serious malformation. Cases with GA had high PMR and low detection rates in prenatal diagnosis, and most often accompanied with multiple defects.

Abdominal Muscles↗
PubMed1996

[Expression of protooncogene bcl-2 in thyroid tumors].

OBJECTIVE: To determine the expression of protooncogene bcl-2 in thyroid tumors and its relationship to the development and prognosis of the tumor. METHODS: 124 cases of thyroid tissues (41 thyroid carcinomas, 53 thyroid adenomas, 20 thyroid tissues adjacent to cancer and 10 normal thyroid tissues) were immunohistochemically stained for bcl-2, by using bcl-2 protein monoclonal antibody. The positive-staining rates in different thyroid tissues were compared statistically. RESULTS: Bcl-2 immunoreactivity was found in thyroid carcinomas (43.9%), thyroid adenomas (22.6%), and thyroid tissues adjacent to cancer (15.0%). The positive-staining rate in thyroid carcinomas was higher than that in thyroid adenomas (P = 0.0439) and that in thyroid tissues adjacent to cancer (P = 0.0430). In thyroid carcinoma, the higher positive-staining rates were found in the cases of undifferentiated carcinoma and follicular carcinoma, as well as in the cases of positive lymph nodes or at tumor stage II and IV. CONCLUSION: The results suggest that the over-expression of bcl-2, a possible prognostic marker of thyroid cancer, may be related to the development of thyroid tumor.

Adenoma↗
PubMed1996

[Morphological effects of ammonia on cultured fetal rat neurons].

The effects of ammonia on cultured fetal rat neurons and the possible relation between morphologic changes of neurons and the pathogenesis of hepatic encephalopathy were studied on dissociated fetal rat neuronal cultures, using light microscopy, transmission electron microscopy and immunohistochemistry methods. The neurons exhibited cellular swelling, chromatolysis, vacuolization and granulation, followed by segmental enlargement and fragmentation of cellular processes, detachment of neurons with pyknotic nuclei. Electron microscopic examination displayed dilation of mitochondria and endoplasmic reticulum, degranulation of rough endoplasmic reticulum, accumulation of dense bodies together with swelling of the process with loss of neurofilaments. The expression of neurofilament and synaptophysin became weak and even negative. The data therefore suggests that ammonia may exert a toxic effect on cultured neurons, disturbing their normal function and facilitating the development of hepatic encephalopathy.

Ammonium Chloride↗