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Biomedical subjects

H J Zhou

Publications and source records attributed to H J Zhou.

17 recordsLinked to original sources
PubMed2007

Observation of locomotor functional recovery in adult complete spinal rats with BWSTT using semiquantitative and qualitative methods.

STUDY DESIGN: Experimental rat model of spinal cord transection . SETTING: China rehabilitation research center. OBJECTIVE: To investigate locomotor functional recovery in spinal rats with BWSTT using semiquantitative and qualitative methods. METHODS: Five-day postoperative (dpo), adult female complete spinal rats (at T(8) level) received 40 days of body weight-supported treadmill training (BWSTT). Signs of functional recovery were examined with average combined scores (ACOS) and Basso Beattie and Bresnahan (BBB) scales at different time points. RESULTS: At 1-dpo, none of the spinal rats exhibited hindlimb movements. The spinal rats displayed functional progress with time, but the rare could recover to full weight-bearing hindlimb at 45-dpo. BBB and ACOS scores in the BWSTT group obtained better scores than those in the spinal cord injury (SCI) group at 30- and 45-dpo. Furthermore, all BBB and ACOS scores of spinal rats reached statistical significance between 7- and 30-dpo, and between 15- and 30-dpo. However, only ACOS but not BBB scores in the SCI and BWSTT groups showed statistics differences between 15- and 45-dpo, and between 30- and 45-dpo. The Spearman correlation coefficients of BBB and ACOS scores were 0.913 and 0.972 for the SCI and BWSTT groups, respectively. CONCLUSIONS: The results confirmed the existence of partial spontaneous hindlimb functional recovery in adult chronically spinal cord-transected rats, and that BWSTT can improve motor performance. In addition, our study suggests that qualitative and semiquantiative methods are strongly correlated with locomotor recovery in spinal rats, and the latter may be more sensitive in reflecting minor variance at different time points.

Analysis of Variance↗
PubMed2006

Refined techniques for intestinal transplantation in rat.

Intestinal transplantation (IT), unlike other solid-organ transplantations, such as liver, kidney, and heart, has relatively disappointing results in humans. Significant advances have been made during the past 40 years, but rejection, graft-versus-host disease (GVHD), and infection remain the major obstacles to successful IT. These aspects may be studied using a rat model of IT. Without a microscope and traditional suture for vascular reconstruction, we simplified the procedure using a "three cuffs" technique for orthotopic intestinal transplantation (OIT). Technical modifications of our OIT model that induced good results included (1) adopting a "double cuffs" technique on the graft aorta, (2) using a portal cuff anastomosis to reconstitute the natural and physiologic portal graft drainage with the cuff fixed to the recipient first, and (3) administering a large volume of crystalloid or whole blood to maintain blood pressure and reduce ischemic injury to the graft during operation. In our group, the survival rate of recipients was 87.5% (21 of 24 rats), the average volume of bleeding in the recipient operation was less than 1 mL, and the cold ischemic time, 50 +/- 11 minutes.

Animals↗
PubMed2006

Association of renal function and delta-aminolevulinic acid dehydratase polymorphism among Vietnamese and Singapore workers exposed to inorganic lead.

OBJECTIVES: To investigate the effect of delta-aminolevulinic acid dehydratase (ALAD) polymorphisms on the association between blood lead and renal function among Vietnamese and Singaporean workers who were exposed to low to medium levels of inorganic lead, and to study the distribution of ALAD polymorphism among Vietnamese, Chinese, Malays and Indians. METHODS: A total of 459 male and female workers were studied. Blood and urine were collected for each worker in order to determine ALAD genotype, blood lead, and urinary delta-aminolevulinic acid (ALAU). Renal function tests included urine albumin (Ualb), urine beta2 microglobulin (Ubeta2m), urinary alpha1 microglobulin (Ualpha1m), N-acetyl-glucosaminidas (NAG), and urine retinol blinding protein (RBP). A multiple regression model with interaction term was applied to fit the entire data and to explore the modifying effect of ALAD polymorphism on the relation of blood lead to each renal function parameter. RESULTS: ALAD1-1 was the predominant genotype for all the ethnic groups while ALAD2-2 was the rarest. The frequency of ALAD2 allele was higher among Malays (8.8%) and Indians (10.6%) compared to the Chinese (5.0%) and Vietnamese (4.3%). The geometric mean of blood lead for all workers was 19.0 microg/dl. The models for Ubeta2m, Ualpha1m, and NAG showed that the ALAD1-2/2-2 group had higher beta coefficients than the ALAD1-1 group. Corresponding to 10 microg/dl blood lead, ALAD1-1 homozygotes had an increment of 1.288 microg/g Cr, 1.175 mg/g Cr, and 1.995 U/g Cr for Ubeta2m, Ualpha1m, and NAG, respectively. ALAD1-2/2-2 subjects had higher increments of 3.802 microg/g Cr, 2.138 mg/g Cr, and 3.89 U/g Cr for Ubeta2m, Ualpha1m, and NAG, respectively. CONCLUSION: The frequency of the ALAD2 allele is as low in Vietnamese workers as in Chinese. Workers with the ALAD2 allele appeared more susceptible to the effects of lead (especially at higher levels) on renal function.

Acetylglucosaminidase↗
PubMed2005

Rabi oscillation damped by exciton leakage and Auger capture in quantum dots.

The decoherence of Rabi oscillation (RO) caused by biexciton, population leakage to the wetting layer (WL), and Auger capture in semiconductor quantum dots is theoretically analyzed with multilevel optical Bloch equations. The corresponding effects on the quality factor of RO are also discussed. We have found that the biexciton effect is relatively trifling, as the pulse duration is longer than 5 ps. The population leakage to the WL leads to a decrease of the RO average even though the damping rate is similar to that observed in the experiment. Auger capture in quantum dots results in RO damping that is consistent with the experimental data, which implies that Auger capture is an important decoherence process in quantum dots.

Journal Article↗
PubMed2005

Coherent control of a V-type three-level system in a single quantum dot.

In a semiconductor quantum dot, the IIx and IIy transitions to the polarization eigenstates, |x> and |y>, naturally form a three-level V-type system. Using low-temperature polarized photoluminescence spectroscopy, we have investigated the exciton dynamics arising under strong laser excitation. We also explicitly solved the density matrix equations for comparison with the experimental data. The polarization of the exciting field controls the coupling between the otherwise orthogonal states. In particular, when the system is initialized into \Y>, a polarization-tailored pulse can swap the population into |x>, and vice versa, effectively operating on the exciton spin.

Journal Article↗
PubMed2001

Inhibition of LZIP-mediated transcription through direct interaction with a novel host cell factor-like protein.

Host cell factor 1 (HCF-1) is a cellular transcriptional coactivator which coordinates the assembly of enhancer complex through direct interactions with viral and cellular trans-activators such as VP16, Oct-1, LZIP, and GA-binding protein. These interactions are mediated by the beta-propeller domain comprising the first 380 residues of HCF-1 with six kelch repeats. Here we describe the identification and characterization of a novel HCF-like kelch repeat protein, designated HCLP-1. HCLP-1 is a ubiquitously expressed nuclear protein which is composed almost entirely of a six-bladed beta-propeller. HCLP-1 selectively interacts with LZIP but not with VP16. The physical interaction between HCLP-1 and LZIP leads to the repression of the LZIP-dependent transcription. The HCLP-1-binding domain of LZIP maps to residues 109-315, which contain the bZIP DNA-binding motif. Electrophoretic mobility shift assay demonstrates that HCLP-1 indeed interferes with the binding of LZIP to its DNA target. Thus, HCLP-1 serves a transcriptional co-repressor function mediated through its inhibitory interaction with the LZIP transcription factor. Our findings suggest a new mechanism for transcriptional regulation by HCF-like proteins.

Amino Acid Sequence↗
PubMed2001

[Effects of artesunate on progestrone estrogen content and decidua in rats].

AIM: To observe the effect of artesunate on content of progesterone, estrogen and decidua of pregnant rats and study the efficacy and mechanism of artesunate for termination of early pregnancy. METHODS: Serum content of progesterone, estrogen and TNF-alpha were measured with RIA. The effects of artesunate on the ovary, decidua and fetus of pregnant rats were studied using histochemistry techniques. Decidual cells were estimated using cell culture. RESULTS: Artesunate 40 mg.kg-1 s.c. on day 6-10 of gestation significantly decreased the concentration of serum progesterone in early pregnant rats; decidual cells and fetus of treated groups were found to be degenerated at d 11. Artesunate was shown to directly damage the decidual cells. Cultured human decidual cells were exposed to artesunate for 48 h, the LC50 was found to be 25 +/- 3 mL.L-1. CONCLUSION: The damage of artesunate on decidua and placenta may be the mechanisms of its contragestational action.

Abortifacient Agents↗
PubMed2000

Termination of early pregnancy in the mouse, rat and hamster with DL111-IT and RU486.

The effectiveness of DL111-IT and RU486 given alone and in combination for terminating early pregnancy was tested in the rat, mouse, and hamster. In the mouse and rat, the combination of RU486 and DL111-IT is much more effective in terminating pregnancy than either of the two compounds used alone (single or multiple treatment). A low-effective dose of DL111-IT in combination with a non-effective or a sub-effective dose of RU486, exerted additive or synergistic effects resulting in resorption of embryos and termination of pregnancy. The serum progesterone concentrations were significantly suppressed by these combinations when pregnancy was terminated. In the hamster, single treatment with DL111-IT plus RU486 exhibited a strong effect on interrupting early pregnancy. The ED50 of RU486 in combination of a non-effective dose of DL111-IT was decreased to 163-fold lower dose than RU486 given alone. It is concluded that in mouse, rat, and hamster, the synergistic action between DL111-IT and RU486 not only greatly enhances efficacy in terminating pregnancy but also reduces substantially the dose required to produce this effect.

Abortifacient Agents, Nonsteroidal↗
PubMed1999

Intrathecal injection of corticotropin inhibited nitric-oxide synthase-positive neuron increase in rat spinal cord after formalin-induced hyperalgesia.

AIM: To study the effects of corticotropin (Cor) on formalin-induced hyperalgesia and the change of nitric-oxide synthase (NOS)-positive neurons in spinal dorsal horn in rats. METHODS: Measurement of pain intensity rating (PIR), NADPH-d histochemistry, and Fos immunohistochemistry were adopted. RESULTS: The increases of NOS-positive neurons, Fos, NOS/Fos double labelling neurons of the spinal dorsal horn and the PIR after formalin injection were markedly inhibited by intrathecal injecting (ith) Cor (0.5-1.5 U), which were obviously attenuated by L-arginine (Arg, 5-15 nmol, ith), the substrate of NOS. CONCLUSION: Cor inhibits formalin-induced hyperalgesia by the decrease of NOS-positive neurons in the spinal dorsal horn of rats.

Adrenocorticotropic Hormone↗
PubMed1991

Embryotoxicity and teratogenicity of DL111-IT, an early pregnancy-terminating agent, in the subsequent gestation following administration in rats.

DL 111-IT is a new non-hormonal early pregnancy-terminating agent. The subsequent embryotoxic and teratogenic effects of DL111-IT were studied in the rats whose first pregnancy had been terminated by the agent. The secondary pregnancy of the treated rats were allowed to initiate at 30-, 45-, and 90-day intervals, respectively, after the termination of the first pregnancy. The toxicities primed with DL111-IT, such as resorbed embryos and nephrohydrosis fetuses, were found to be 8.0% and 8.5%, respectively, in the rats with pregnancy at 30-day interval. This is significantly different from 4.0% resorbed embryos and 2.4% nephrohydrosis fetuses in vehicle control (P less than 0.05). However, the rate of resorbed embryos decreased to 7.0% or 6.0% in the rats with pregnancy at 45- or 90-day intervals, respectively. No other significant embryotoxicity and teratogenicity were observed in those rats initiating their pregnancy 45 days later after first-pregnancy termination by DL111-IT. Thus, DL111-IT appears to have very low subsequent toxicity in the course of rat pregnancy cycles.

Abnormalities, Drug-Induced↗
PubMed1990

[Latin square vs twin crossover design for mouse blood glucose assay to estimate insulin potency].

According to parallel line analysis, a Latin square design was used for estimating insulin potency in mouse blood glucose assay. Four to six groups of 4 x 4 Latin squares were used to estimate 80%, 100% and 120% standard preparations and the recovery rates were 95-106%. Meanwhile, in comparison with twin crossover design, 13 batches of variant preparations including some beyond expiry dates were checked by Latin square design. The results showed that the potencies were about the same in two designs. The average fiducial limit rates were still less than 25% but 40% or so of animal numbers were saved. Therefore, Latin square design in a precise and accurate assay for the estimation of insulin.

Animals↗
PubMed1989

[Fibro-osseous lesions of the jaw and facial bones: a clinico-histologic-radiologic study of 138 cases].

A clinical-histologic-radiologic study of 138 cases of fibro-osseous lesions of the jaw and facial bones is presented. In this series, all were monostotic lesions except 8 polyostotic fibrous dysplasia. In the 130 monostotic lesions, 59 occurred in maxilla, 66 in mandible, 4 in zygoma and one in ethmoid bone. Clinically, a painless enlargement of the involved bone was the main sign. Histologically, these lesions were composed of proliferating fibrous connective tissues and various amounts of calcified tissues, but different lesion has different feature. Radiologically, fibrous dysplasia was characterized by lesions with diffuse blending. The other three tumors including ossifying fibroma, cementifying fibroma and fibro-osteoma were all represented by lesions with well delineated borders. In this article, Diagnosis of the fibro-osseous lesions and some questions about fibro-osteoma of the jaw and facial bones and osteofibrous dysplasia of long bones are discussed.

Adolescent↗
PubMed1989

[Multivariate twin crossover design parallel line assay for estimating potency of insulin].

Based on twin crossover design, a multivariate assay design was used in parallel line analysis to estimate the potency of insulin. This paper describes how to make the experimental design. After the analysis of variance according to assay, the potency and fiducial limits were calculated by the method (2.2). It has been applied by multivariate assay to estimate 80, 100 and 120% standard preparation and the recovery rate were between 94 and 108%. We also tested various batches and agent products. The average fiducial limits rates were less than 20%. In comparison with twin crossover analysis as usual, multivariate assay appeared to provide a more efficient utilization of experimental data, to increase weight of every animal for a more accurate estimation of potencies and to save on animal numbers 30-40%.

Animals↗
PubMedDate not supplied

The changes of gene expression profiles in hydatidiform mole and choriocarcinoma with hyperplasia of trophoblasts.

The purpose of this study is to investigate changes of gene expression profiles in hydatidiform moles (HM) and choriocarcinoma and to explore causes of trophoblastic hyperplasia. Using cDNA microarray, 4,096 genes were analyzed in two pairs of the tissues of HM versus normal villi and in two pairs of normal primary culture trophoblasts versus JAR cell line of choriocarcinoma. The expressions of two genes in normal villi and HM, as well as in JAR and JEG-3, were examined with the help of immunohistochemistry, immunoblot, and reverse transcriptase-polymerase chain reaction in order to confirm the findings of cDNA microarray. Twenty-four genes were upregulated and 65 genes were downregulated in all HM. Four hundred thirty-three genes were upregulated and 380 genes were downregulated in JAR. Forty-six genes were upregulated in both HM and choriocarcinoma, whereas 13 genes were downregulated. Genes associated with the inhibition of cell proliferation were significantly downregulated, whereas genes associated with cell proliferation, malignant transformation, metastasis, and drug resistance were upregulated. Thymidine kinase-1 (TK-1) and small subunit ribonucleotide reductase (RRM-2) were overexpressed in HM, JAR, and JEG-3. The expressions of TK-1 and RRM-2 in moles were positively correlated with proliferative index of trophoblasts. Our results suggest that altered expression of genes exist in HM and choriocarcinoma. Trophoblastic hyperplasia may be involved in the overexpression of DNA synthetic enzymes.

Adult↗