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Biomedical subjects

W J Zhou

Publications and source records attributed to W J Zhou.

14 recordsLinked to original sources
PubMed2006

Semen quality in a residential, geographic and age representative sample of healthy Chinese men.

BACKGROUND: Population-based study of semen quality is rare in literature. METHODS: Healthy men aged 20-60 years from six Chinese provinces were invited to participate in the study between December 2000 and November 2002. Posters were distributed in the participating counties to enroll 200 subjects from each province. Medians, percentiles, and proportions below lower threshold of the WHO criteria for semen parameters were calculated. Generalized linear models were used to examine the determinants of semen quality. RESULTS: Semen samples from 1191 healthy Chinese men were collected and analysed. The medians (5th and 95th percentiles) were 2.3 ml (1.0-4.5) for semen volume, 65 x 10(6)/ml (20-150) for semen concentration, 154 x 10(6)/ejection (29-421) for sperm count, 19% (5-32) for rapid progressive motility, 46% (29-66) for progressive motility, 67% (47-81) for total motile spermatozoa, 70% (48-88) for sperm viability and 39% (23-76) for normal morphology. Many healthy Chinese men had semen parameter values below the lower threshold of the WHO criteria. Region, age, abstinence duration and season were important determinants of semen quality. CONCLUSIONS: Chinese men have lower values of semen parameters according to WHO standard, and a lower threshold for normal semen parameters for Chinese men should be considered.

Adult↗
PubMed2004

In vitro infection of host roots by differentiated calli of the parasitic plant Orobanche.

Root parasites of the genus Orobanche are serious weeds in agriculture. An aseptic infection system of host roots using calli of three Orobanche species was developed for the study of host-parasite interaction. The response of calli to various hormonal combinations was studied, because a requirement for infection is the differentiation of root-like protrusions, which are capable of producing haustorial connections to the host. Infectious root-like protrusions develop under the influence of 0.5-1.0 mg l(-1) IAA, and under the combination of 0.2 mg l(-1) NAA with 5.0 mg l(-1) kinetin. These protocols produced root protrusions with pad-like structures that resembled attachment organs of Orobanche seedlings, and proved effective in parasitizing host roots. Direct contact with the medium inhibited haustorium development and prevented infection. To overcome this problem, certain root portions were isolated from the medium by inserting thin glass plates underneath. Calli were then placed on the raised root portions and successfully infected the roots and developed young Orobanche tubercles with vascular system that directly connected to the host.

Brassica napus↗
PubMed2001

Polymerized lyotropic liquid crystal assemblies for materials applications.

The development of functional materials with nanometer-scale architectures and the effect of these architectures on their chemical and physical properties are currently of great interest in materials design. Polymerizable lyotropic liquid crystal (LLC) assemblies provide a facile entry into this area by allowing one to fix the inherent order in these systems using covalent bonds to create robust, nanostructured materials. The use of the cross-linked inverted hexagonal phase in templated nanocomposite formation and heterogeneous catalysis has been demonstrated. Additionally, the polymerization of LLC mesogens in the regular hexagonal and bicontinuous cubic phases is being targeted for future developments in functional materials. Future directions for new applications of these materials are also discussed.

Journal Article↗
PubMed2001

[The creation of 1H chromosome-specific CAPs and ASA markers of barley].

Sequence-Tagged Site(STS) marker is a kind of important marker for identifying heterogeneous chromosome on account of its simplicity, speediness and specificity. There are many STS markers in use, which changed from the RFLP and RAPD markers. But some of those from RFLP markers cannot directly be used for identifying the specific chromosomes, such as MWG913. Amplified wheat genome by MWG913, a STS marker of barley's 1H chromosome, then cloned the products. These clones were classified by restricted enzyme Taq I and then sequenced. On the basis of the results of these sequences compared with barley's (obtained from the GenBank)., two restricted enzyme specifying on 1H chromosome, EcoR I and Pvu I, were chosen to digest the PCR products of T. aestivum, Secale cereale, Hordeum vulgare, Agropyron intermedium, Haynaldia villosa, Thinopyrum elongatum and identified their specilization to Hordeum vulgare genome. Furthermore, according to the difference of Pvu I recognition site, the second PCR primers were designed and identified its specificity to Hordeum vulgare genome by PCR. Thus 1H chromosomespecific CAPs and ASA markers of barley were obtained.

Base Sequence↗
PubMed2001

[Evolution study of wheat (Tritium aestivum L.) A, B and D genome based on DNA sequence similarity].

Tritium aestivum L., and its four potential origin species T. urartu T., T. monococcum L., Ae. squarrosa L. and T. dicoccum S., were amplified with MWG913, a STS marker located in 1H chromosome of barley. Those products are cloned and sequenced. By the discrepancies of these sequences, we have obtained some evidences about the origin of wheat A, B, D genomes at molecular level. The results showed that the studied sequence in A genomes of Tritium aestivum L. was identical with that of T. urartu T., T. monococcum L. and T. dicoccum S.; that in D genome of Tritium aestivum L. was as same as that of Ae. squarrosa L.; that in B genome of Tritium aestivum L. differed from that of T. dicoccum S. in 0.61%. The results also suggested that A, B and D genome have the different evolution speed.

Biological Evolution↗
PubMed2001

[Chromosomal location and molecular marker of resistance gene to Puccinia striiformis west. in Leymus mollis Trin. Hara].

The hybrid wheat line, 93784 is a stable line selected from progenies of Leymus molli Trin. Hara x common wheat, which shows a very high level of resistance to yellow rust. The results of GISH using genomic DNA of Leymus mollis as probe indicated that the 93784 was a wheat-Leymus mollis small segment translocation line, and the translocated alien chromosome fragment were located on a pair of short arm terminals of what chromosomes. Using this translocation line, we established F2 segregation population and identified its yellow rust resistance in adult stage. Genetic analysis suggested that the yellow rust resistance of 93784 was controlled by a single gene. The gene was located on the translocated chromosome segments of Leymus mollis. We called it YrLm. By AFLP analysis with Taq I (T1-T4)/Pst I (P1-P6) primes in individuals of F2 segregation population and their susceptive and resistant parents, we screened a molecular marker that linked to yellow rust resistance gene YrLm. We also cloned and sequenced the molecular marker. The length of the marker is 205 bp, named P1T(3)205.

Chromosome Mapping↗
PubMed2000

[The chromosome-specific PCR marker's screening and identification of barley 6H chromosome].

Two barley 6H chromosome specific RAPD markers were obtained by screening DNA of barley Hordeum vulgare (Betzes) and wheat-barley 6H addition line with 200 primers, then the RAPD markers were changed into specific PCR markers. Checking different plant materials by the PCR markers, it revealed that there was a specific band in those materials containing 6H chromosome such as Betzes, Igri, CS6H, and there was no specific band if the material did not contain 6H chromosome, such as Triticum aestivum, Secale cereale, Agropyron intermedium, Haynaldia villosa, Thinopyrum elongatum. Therefore, those PCR markers specific to chromosome 6H of barley are established. Southern hybridization indicated that the two cloned DNA fragments belong to barley genomic specific high-copy repeat sequence and low-copy sequence in wheat and barley genomes respectively.

Base Sequence↗
PubMed1996

[Effect of acute hypoxia on the change of hippocampal NE content and plasma cortisol level].

The effect of acute hypoxia on the changes of plasma cortisol level and hippocampus NE level of cat during inhalation of 21%, 10.4% or 7.9% O2 were investigated. It was found that both 10.4% and 7.9% O2 inhalation caused a gradual increase in plasma cortisol level reaching a plateau in 30-45 min time. While the contents of NE in VHIP and DHIP showed significant decrease 30 min after hypoxia. The degree of both these changes are not related to the hypoxic level of the inhaled O2. The results show that acute hypoxic stress would induce some increase in plasma cortisol level and some decrease in hippocampus NE content.

Animals↗
PubMed1995

[Participation of septum on the increase of plasma cortisol level induced by stimulation of the greater splanchnic nerve of cats].

Experimens were performed on 36 cats, showing that stimulation of the central end of the left major splanchnic nerve induced an increase of the plasma cortisol level. The centripetal effect was abolished by lesioning the septal nuclei, just as the same as injection of propranolol into the nuclei; but phentolamine had no such preventive action. All the findings show that it is the noradrenergic beta-receptor system of the septal nuclei that exerts a considerable effect on cortisol secretion.

Adrenergic Antagonists↗
PubMed1992

[Alpha-receptor mediated effect of injection of norepinephrine into hippocampus on plasma cortisol level in cats].

In the present experiment, the effect of injection of NE into the different areas of hippocampus on the plasma cortisol level and the kind of NE receptor involved were studied in 83 cats anesthetized with Nembutal. The plasma cortisol level was increased following injection of NE into the ventral hippocampus (VHIP), however, there was no significant change when injection was made into dorsal hippocampus. The NE-VHIP effect can be blocked by injection of phentolamine, yohimbine or prazosin but not by propranolol. Thus, these results show that, in the regulation of the plasma cortisol level, the alpha-receptor system of VHIP is more specifically involved.

Animals↗
PubMed1989

[Studies on enhancement of nonspecific resistance to infection by leptospiral lipopolysaccharide. II. The mechanisms of the nonspecific protective activity of the LPS].

Leptospiral lipopolysaccharide can enhance the nonspecific resistance of host to infection. By researching its mechanism, we found: (1) The phagocytic function of peritoneal macrophages of guinea pigs was strengthened by E-LPS and L-LPS; (2) L-LPS and E-LPS activated peritoneal macrophages of mice then enlarging the cell raji, and increase the quantity and activity of intracellular acid phosphatase. Relatively, the L-LPS might have a greater action in synthesis of the enzyme, while the E-LPS mainly enhanced the activity of the enzyme; (3) L-LPS and E-LPS appeared to be immunomodulant. When they were injected 3d after immunizing the mice with SRBC, immune adjuvant effect developed; however, if the injection of LPS was made 24h prior to the immunization, it would result in immunosuppression.

Acid Phosphatase↗