Biomedical subjects

C Zhou

Publications and source records attributed to C Zhou.

At least 73 records · Page 4Linked to original sources

PubMed2000

Identification of a novel mutation in patients with medium-chain acyl-CoA dehydrogenase deficiency.

A novel mutation was identified in two unrelated patients with medium-chain acyl-CoA dehydrogenase deficiency. First, a 19-year-old Caucasian female presented with a devastating illness, resulting in sudden death in adulthood which is unusual. The second patient, now a 3.5-year-old male, presented at 17 months of age with a hypoglycemic seizure and dehydration. Sequence analysis revealed a novel mutation G617T in exon 8 resulting in an arginine to leucine substitution at codon 206 (R206L). Both patients were compound heterozygous for this G617T and the common mutation A985G.

Acyl-CoA Dehydrogenase↗

PubMed2000

Construction and analysis of three-dimensional graphic model of single-chain Fv derived from an anti-human placental acidic isoferritin monoclonal antibody by computer.

A three-dimensional (3D) graphic model of a single-chain Fv (scFv) which was derived from an anti-human placental acidic isoferritin (PAF) monoclonal antibody (MAb) was constructed by a homologous protein-predicting computer algorithm on Silicon graphic computer station. The structure, surface static electricity and hydrophobicity of scFv were investigated. Computer graphic modelling indicated that all regions of scFv including the inker, variable regions of the heavy (VH) and light (VL) chains were suitable. The VH region and the VL region were involved in composing the "hydrophobic pocket". The linker was drifted away VH and VL regions. The complementarity determining regions (CDRs) of VH and VL regions surrounded the "hydrophobic pocket". This study provides a theory basis for improving antibody affinity, investigating antibody structure and analyzing the functions of VH and VL regions in antibody activity.

Amino Acid Sequence↗

PubMed2000

Splice variants of PAC(1) receptor during early neural development of rats.

The specific pituitary adenylate cyclase-activating polypeptide (PACAP) receptor, PAC(1)-R, consists of at least seven isoforms, and they are differentially coupled to signal transduction pathways by alternative splicing. We have found that the major splice variants of the PAC(1) receptor seen during development are the short splice isoform, PAC(1)-R-s (which does not contain either the "hip" or "hop" cassette), and another form, PAC(1)-R-hop (which contains the "hop" cassette). We also have applied an innovative molecular histochemical technique, in situ reverse transcription-polymerase chain reaction (RT-PCR), and determined that these two splice isoforms are colocalized in the neuroepithelia from the primitive streak stage.

Alternative Splicing↗

PubMed2000

Inhibition of interleukin-1beta (IL-1beta) production in human cells by ribozymes against IL-1beta and IL-1beta converting enzyme (ICE).

We and others have shown previously that hairpin ribozyme genes, when stably expressed in cells, can reduce the steady-state levels of target mRNA and their cognate proteins. Despite this capability, ribozymes have not been as widely used in knockdown experiments as one might expect, probably because specific rules governing the selection of ribozymes that will have high activity have not been described. In this report, we show that parallel screening of less than 10 ribozyme expression constructs, with no advanced knowledge of cleavage activity or preselection, can efficiently identify knockdown ribozymes. This empirical selection study, which used interleukin-1beta (IL-1beta) and IL-1beta converting enzyme (ICE) as example targets, resulted in (1) the rapid identification of ribozymes that can reduce the production of IL-1beta in THP-1 cultures by 10-fold and (2) the consequent direct generation of stable knockdown cell lines. We conclude, based on these and similar studies, that parallel screening of ribozyme constructs could be used in high throughput gene functional analysis programs as a means of rapidly generating specific knockdown cell lines.

Caspase 1↗

PubMed2000

Phase synchronization in coupled nonidentical excitable systems and array-enhanced coherence resonance

We study the dynamics of a lattice of coupled nonidentical Fitz Hugh-Nagumo system subject to independent external noise. It is shown that these stochastic oscillators can lead to global synchronization behavior without an external signal. With the increase of the noise intensity, the system exhibits coherence resonance behavior. Coupling can enhance greatly the noise-induced coherence in the system.

Journal Article↗

PubMed2000

Symmetry-breaking on-off intermittency under modulation: robustness of supersensitivity, resonance, and information gain

Nonlinear dynamical systems possessing an invariant subspace in the phase space and chaotic or stochastic motion within the subspace often display on-off intermittency close to the threshold of stability of the subspace. In a class of symmetric systems, the intermittency is symmetry breaking [Ying-Cheng Lai, Phys. Rev. E 53, R4267 (1996)]. We report interesting and practically important universal behavior of robustness of supersensitivity, resonance, and information gain in this class of systems when subjected to a weak modulation. While intermittent loss of synchronization may be harmful to the application of high-quality synchronization of coupled chaotic systems, the features reported here may lead to interesting application of on-off intermittency.

Journal Article↗

PubMed2000

Overexpression of Na(+)-dependent myo-inositol transporter gene in mouse lens led to congenital cataract.

PURPOSE: Maintaining appropriate osmotic pressure is essential for maintaining lens transparency. This study was performed to investigate whether high levels of myo-inositol, one of the major organic osmolytes in the lens, would lead to cataract development. METHODS: Transgenic mouse lines carrying the bovine Na(+)-dependent myo-inositol transporter (bSMIT) cDNA under the control of the mouse alphaA-crystallin promoter were generated. RESULTS. Increased bSMIT expression was accompanied by increased myo-inositol level in the lens and increased uptake of (3H) myo-inositol by the lens in culture. The transgenic mice developed observable cataract under normal rearing conditions beginning at 2 to 8 weeks of age, and the severity of cataract development was correlated to the level of bSMIT gene expression and lens myo-inositol accumulation. For transgenic mouse line 3352, heterozygous mice did not develop cataract, whereas homozygous ones did. Prenatal feeding of heterozygous 3352 mice with high myo-inositol diet led to cataract development, indicating that cataract development was not merely due to a nonspecific effect of SMIT overexpression. Introducing aldose reductase overexpressing transgene into heterozygous 3352 mice also led to cataract development, indicating that this type of cataract is primarily due to osmotic stress. CONCLUSIONS: The present results indicate that high levels of myo-inositol and sorbitol in the lens contribute to cataract development. This is a useful model to study the role of osmotic stress in cataractogenesis during lens development.

Aldehyde Reductase↗

PubMed2000

Investigation on interaction between Streptococcus sanguis and Porphyromonas gingivalis in specific pathogen-free rats.

OBJECTIVE: To examine whether endogenous Streptococcus can prevent or reduce the colonization of the virulent Porphyromonas gingivalis strain. METHODS: Successful implantation of the endogenous strain of S. sanguis and P. gingivalis 381 within 14 days was demonstrated in the study rats following administration of doxycycline for 7 days. Thirty specific pathogen-free (SPF) rats were divided into 6 groups. After administration of doxycycline for 7 days, groups A and B were inoculated orally once a day for 5 days with P. gingivalis. Group C and E were inoculated orally once a day for 5 days with S. sanguis. Then, group A was inoculated for 5 days with S. sanguis, and rats in group C and D were inoculated for 5 days with P. gingivalis. Group F served as a negative control. After inoculation, the levels of S. sanguis and P. gingivalis in the mouths of the rats were determined at 12 hours, 24 hours, 36 hours, 7 days, and 14 days. RESULTS: Both precolonization of S. sanguis and superinfection with S. sanguis reduced the level of P. gingivalis in experimental rats. However, the reduction was maintained for only 24 to 36 hours. The level of S. sanguis remained stable during the 14-days observation period. CONCLUSION: S. sanguis to function as the effector strain, the successful implantation of S. sanguis and the antagonistic action efficiently produced in vivo by S. sanguis is required.

Animals↗

PubMed2000

[Treatment options of clomiphene-resistant polycystic ovary syndrome related infertility].

OBJECTIVE: To investigate the treatment options of clomiphene(CC)-resistant polycystic ovary syndrome (PCOS) related infertility. METHODS: Fifty-nine PCOS patients with CC resistant-anovulation were accepted and treated by the following three protcols: (1) follicle-stimulating hormone (FSH) group, 49 cycles; (2) FSH + pulsatile gonadotropin-releasing hormone(GnRH) group, 13 cycles; (3) conventional in vitro fertilization (IVF)-embryo transfer (ET) group, 19 cycles. Suppressive treatment on serum luteinising hormone (LH) and testosterone (T) levels was given in the first and second groups in advance. Serum estradiol level; pregnancy rate; miscarriage rate, ovarian hyperstimulation syndrome (OHSS) and multiple pregnancy rate were compared among the three groups. RESULTS: The pregnancy rate in FSH group, FSH + GnRH group and IVF-ET group were 37%, 54% and 22% respectively. The highest rate and multiple pregnancy rate was found in IVF-ET group. CONCLUSION: The rationale treatment options for CC-resistant PCOS related infertility was the addition pre-suppressive treatment, low-dose FSH stimulated regimen subsequent pulsatile GnRH infusion. IVF were only accepted after failure with gonadotropin therapy.

Adult↗

PubMed2000

[Recurrence, metastasis and complications of stage I and II endometrial neoplasms treated by different therapeutic modalities].

OBJECTIVE: To make an approach to the relationship between recurrence, metastasis and complication of stage I and II endometrial carcinoma treated by 4 different therapeutic modalities. METHODS: To compare the rates of recurrence, metastasis and complication in 4 treatment groups (surgery, full-dose preoperative intracavitary irradiation, non-full dose preoperative intracavitary irradiation and radiation alone). RESULTS: Recurrence and metastasis in surgery, full-dose preoperative intracavitary irradiation, non full-dose preoperative intracavitary and radiotherapy alone groups were 19.8%, 8.1%, 22.2% and 34.6%, respectively. The recurrent rates of vaginal stump were 6.2%, 1.6%, 11.1% and 11.5%, respectively. The rates of proctitis and cystitis in full dose preoperative intracavitary irradiation group were 3.2% and 3.2%, 2.8 and 0.0% in non-full dose preoperative intracavitay irradiation group, and 0.0% and 3.8% in radiotherapy alone group. CONCLUSIONS: The rates of recurrence and metastasis in full-dose preoperative intracavitary irradiation group were the lowest compared with other groups and incidence of complication was also low. This therapeutic method is the optimal choice for the treatment of endometrial carcinoma with stage I and II.

Endometrial Neoplasms↗

PubMed2000

[In vitro study of prolactin secretion by ectopic endometrial stromal cells].

OBJECTIVE: To investigate the relationship between prolactin (PRL) secretion by ectopic endometrial stromal cells and elevated PRL concentrations of peritoneal fluid in patients with endometriosis. METHODS: Twelve samples of each ectopic endometrium and normal endometrium were separated and cultured in vitro. After stimulated with progesterone(10(-8) mol/L) for 6 days, PRL levels in the media of cultured stromal cells from both tissue types were measured by enzyme-labeled immunosorbent assay(ELISA). A study of correlation between PRL level in culture supernatant of stromal cells from ectopic endometrium and American Fertility Society (AFS) classification of endometriosis score was performed. The expression of PRL protein of stromal cells from both tissue types were determined by immunocytochemical method. RESULTS: PRL was secreted in similar concentrations by stromal cells from both tissue types. The mean levels of PRL in ectopic and normal endometria were (21.8 +/- 8.0) and (24.5 +/- 7.9) micrograms.L-1.6 d-1 per, respectively (P > 0.05). There is significant positive correlation between PRL secretion by ectopic endometrial stromal cells and the scoring of endometriosis (P < 0.05). There were no significant difference in the immunostaining integral score of PRL between the two groups. CONCLUSION: Production of PRL by ectopic implants of endometriosis is likely to be a contributing factor of the elevated peritoneal fluid PRL in patients with endometriosis.

Adult↗

PubMed2000

Preclinical trials of human erythrocyte superoxide dismutase injection.

OBJECTIVE: To assess the quality of human erythrocyte superoxide dismutase (SOD) injection reaching the official standard for its clinical uses. METHODS: Human erythrocyte SOD injection prepared by McCord-Fridovich's method without column chromatography but with some modifications was used in preclinical trials, to observe the general pharmacology and pharmacodynamics of the product. RESULTS: The quality of human erythrocyte SOD injection conformed to the official standard of a biological product, which was found to be non-toxic and did not have any effects on the central and autonomic nervous systems as well as cardiovascular and respiratory systems. The efficacy of anti-inflammation and promotion of immuno-regulation especially on carrageenan and adjuvant-induced polyarthritis were shown in animals. CONCLUSION: Human erythrocyte SOD injection is appropriate for prophylactic and therapeutic uses in clinical trials.

Animals↗

PubMed2000

[Reinsemination by intracytoplasmic sperm injection 24-hour after conventional in vitro fertilization failure].

OBJECTIVE: To examine the efficacy of intracytoplasmic sperm injection (ICSI) for rescue of conventional in vitro fertilization (IVF) failure. METHODS: From June 1997 to October 1998, 17 women with non-male factor infertility undergoing conventional ovarian hyper-stimulation protocol and IVF in our center, with fertilization failure were reinseminated by ICSI. RESULTS: Intracytoplasmic sperm injection of 130 unfertilized mature oocytes resulted in degeneration in 25 oocytes, successful fertilization occurred in 100 (76.9%) of the survival oocytes, and embryo transfer were done in 18 cycles. Two viable pregnancies resulted. CONCLUSION: If chromosome abnormalities of embryos arising from reinsemination were ignored, our results suggest that ICSI is a successful means of rescuing conventional IVF failure.

Adult↗

PubMed2000

[The effect of antisense hsp90 beta on the malignant phenotype and sensitivity of HeLa cells to chemotherapeutic drugs].

OBJECTIVE: To study the effects of hsp90 beta on tumorigenesis and sensitivity of HeLa cells to chemotherapeutic drugs. METHODS: A recombinant plasmid expressing either sense or antisense hsp90 beta RNA, and a vector pLXSN were transfected into HeLa cell line by lipofectin method. The transfected cells were screened by G418. The growth rates of the transfected HeLa cells and their sensitivity to adriamycin(ADM) and cisplatin (CDDP) were examined by cell count and MTT uptake. Colony formation in soft agar was used to embody the malignant phenotype in vitro. RESULTS: There was little difference between HeLa cells transfected with sense RNA plasmids and pLXSN vector. The growth rate of HeLa cells transfected with antisense RNA declined, and their ability to form colony in soft agar was decreased. The sensitity of the antisense hsp90 beta transfected HeLa cells to ADM and CDDP increased 2.1-5.8 fold; the LD50 decreased to 1/2-1/5 that of the wild-type HeLa cells. CONCLUSION: Hsp90 beta is involved in the maintenance of malignant phenotype and drug resistance in HeLa cells.

Antineoplastic Agents↗

PubMed2000

[Experiment study of guiding bone tissue regeneration by frozen homologous periosteum].

OBJECTIVE: Explores the feasibility of guiding bone tissue regeneration by frozen homologous periosteum. METHODS: Rabbit's cranial periosteum was taken and refrigerated. In thirty-one white Japanese big ear rabbits, defects of the mandible were created. Defect at one side was covered with the membrane, another side not. The rabbits were sacrificed on four, eight, twelve, sixteen weeks. Specimens were examined by naked eye, X-ray, and histology. RESULTS: The frozen homologous periosteummet the requirement of guiding bone tissue regeneration There was no rejection, and could be kept 8 for 12 weeks in the body. It had the favorable efficacy of obstructing the fiber tissue from filling into bone defects and had an efficacy of guiding bone tissue regeneration. CONCLUSIONS: Frozen homologous periosteum is a perfect guiding bone tissue regeneration membrane.

Animals↗

PubMed2000

[Using testicular sperm to provide fertility for azoospermia men].

OBJECTIVE: To investigate the effect of intracytoplasmic sperm injection (ICSI) on providing fertility for obstructive and non-obstructive azoospermia men after testicular spermatozoa extraction (TESE). METHODS: TESE and ICSI were performed at the day of ovum pick up. RESULTS: TESE and ICSI were performed successfully for 11 cycles in obstructive azoospermia men; The fertilization rate (FR) and clinical pregnancy rate (PR) were 67.0% (69/103) and 18.2% (2/11), respectively. In non-obstructive azoospermia group (21 cycles) including 3 cases of severe oligozoospermia, only in 13 cycles could sperm be found to perform ICSI, with the FR of 59.0% (72/112); 11 cycles had embryo transfer, and the average embryo number for transfer was 2.8. Three cases got clinical pregnancy. In 8 cycles, TESE were failed. The first case delivered a normal boy in June 1998. CONCLUSIONS: Using testicular sperm for ICSI is relatively difficult, but it is a practical method to provide fertility for obstructive or non-obstructive azoospermia men. Its efficacy, however, is needed to be improved.

Female↗

PubMed2000

[A study on incidence of injury and its socio-economic loss in children and young adults].

OBJECTIVES: To study the current status of incidence of injury among children and young adults and the causes of common injuries, and to estimate its socio-economic loss and extent of harmfulness. METHODS: Pupils in 19 primary and middle schools aged 7 to 18 years, totaling 14,533, were recruited with stratified cluster sampling during 1998 to 1999 in Guangzhou, Maoming, Jiangmen and Shantou. Judgement for injury was based on the following criteria: (1) diagnosed and treated in hospitals or school clinics, (2) a half-day off or more due to injury, and (3) emergency management by pupils' parents or teachers. RESULTS: There were 6 941 pupils suffered from varied injures during the year, with an incidence rate of 47.76% (50.08% for boys and 45.02% for girls). Incidence rate of injury was higher in the middle school pupils (13 - 18 years old, 58.49%) than that in the primary school pupils (7 - 12 years old, 40.08%). The incidence increased significantly with age, with a peak at ages of 13 - 15. Major causes of injuries resulted from falls, injury by sharp articles, collision, traffic injuries and burn/scalds, etc, which usually occurred due to carelessness in sports, playing, walking, bike-riding and working. Frequency of multiple injuries related to the educational level of parents and depended on whether or not an only-child in family. There were 2,173 injured pupils (accounting for 31.3% of the total) visited clinics or emergency department in hospitals and 627 (9.0%) hospitalized for treatment. Twenty-eight percent of the injured pupils were absent from school, with an average absenteeism of 5.6 days. There were 154 injured pupils with transient disability and 53 with permanent disability, with a disability rate of 410.47 per 100,000. Cost for their medical care averaged 81.5 yuan RMB per injured pupil. CONCLUSIONS: Injury was a common and frequently-happened incident among children and young adults and could seriously affect their health, development and growth, studying and their future of children and young adults. Health education, safety-promotion and removing hidden danger for injury are the major measures to prevent from injury, and the government and the whole society should pay great attention to injury issues in children and young adults.

Accidents↗

PubMed2000

[A comprehensive evaluation on intervention measures for injuries in primary and middle school students].

OBJECTIVE: To explore the intervention measures for prevention and control of injuries and evaluation for their effectiveness in students of middle and primary schools. METHODS: Effectiveness of intervention was evaluated by comparison of incidence of injury before and after intervention in 3,896 students of nine middle and primary schools and comparison with a non-intervention group in 651 students of four primary schools in Jiangmen City, Guangdong Province during January to December, 1999. RESULTS: Incidence of injury dropped to 11.78% after intervention from 50.55% before intervention in the intervention group, with 76.70% of reduction. Proportion of severe injury dropped to 0.65% after intervention from 7.84% before intervention. Incidence of multiple injuries dropped to 3.15% from 19.16%, with 83.56% of reduction. But, in the control group, incidence of injury dropped to 49.00% from 52.67%, with 6.97% of reduction only, with a ratio of reduction of intervention to control of 11.02% and a ratio of cost to benefit of 1:13.9. CONCLUSION: Intervention measures focusing on health promotion can prevent and control the occurrence of injury in students of middle and primary schools cost-effectively.

Accident Prevention↗