Biomedical subjects

Ji-Hong Liu

Publications and source records attributed to Ji-Hong Liu.

11 recordsLinked to original sources

PubMed2003

[Advance in calcium channel blockers relaxing corpus cavernosum smooth muscle].

Calcium channels exist extensively in the membrane of cardiac, skeletal, smooth muscle cell and neuron. Calcium channel blockers (CCB) were widely used for the treatment of cardiovascular diseases because they could relax vascular smooth muscle. Experimental researches on calcium channel blockers relaxing corpus cavernosum smooth muscle have been reported recently. Whether the blockers can be used for the clinical diagnosis and treatment of erectile dysfunction still need to be further investigated.

Animals↗

PubMed2003

[Genetic variation of Citrus calli revealed by the ploidy analyser].

The cell DNA content of forty-eight Citrus calli of different genotype were measured by using the Ploidy Analyser. The results showed that 93.8% out of forty-eight Citrus calli had double DNA content except that Ruby. Weizhang and Kinnow had little varied cells and did not show second peak. Moreover, Pineapple, Meiwa kumquat, Changsha, Russ navel, Guoqing No. 4 and Carter had DNA varied cells including triploids and aneuploids based on the DPAC software analyse. Among the forty-eight Citrus calli, Pineapple had the highest of the DNA varied cells, which was up to 18.57%, Anliucheng had the lowest, 4.07%. There existed significant difference in the variation among genotypes by Duncan Analyse. At the same subcultured medium and at the same subcultured period, the effect of cultural duration on the variation of calli was not significant.

Aneuploidy↗

PubMed2003

Influences of dibutyryl cyclic adenosine monophosphate and forskolin on human sperm motility in vitro.

AIM: To study the influences of dibutyryl cyclic adenosine monophosphate (dbcAMP) and forskolin on human sperm motility in vitro. METHODS: Semen samples, aseptically obtained by masturbation and prepared by swim-up technique from 20 fertile men, were incubated with different concentrations of dbcAMP and forskolin at 37 deg. Measurements were carried out after 10 min, 20 min, 30 min and 60 min incubation. Motility parameters were estimated by using an automatic analyzing system. RESULTS: Treatment with dbcAMP or forskolin resulted in a significant increase in sperm motility and progressive motility. The larger the concentrations of dbcAMP or forskolin, the greater the effect appeared. The straight linear velocity and curvilinear velocity were not affected by both agents. CONCLUSION: dbcAMP and forskolin increase the motility and progressive motility of human sperm in vitro.

Adult↗

PubMed2003

[The relaxation effects of tetrandrine on the corpus cavernosum tissue of rabbit in vitro].

OBJECTIVES: To study the relaxation effects of tetrandrine on the corpus cavernosum tissue of rabbit in vitro. METHODS: 1. The fluctuation of the dose-response relaxation curves for the contraction of KCl induced by tetrandrine was observed with isolated rabbit corpus cavernosum tissue. 2. Isolated strips of rabbit corpus cavernosum tissue were precontracted with 10 mumol/L phenylephrine(PE). Relaxation in response to cumulative doses of tetrandrine was determined in the absence and presence of nitric oxide synthase inhibitor (L-NNA) and soluble guanylate cyclase inhibitor (methylthioninium). RESULTS: 1. The dose-response curves of KCl were shifted to the right nonparallelly, and the maximal responses were depressed to (73.0 +/- 3.8)% and (41.5 +/- 3.4)%, respectively, in the presence of tetrandrine(10 mumol/L, 30 mumol/L). 2. On rabbit cavernosal muscle stripes precontracted with PE(10 mumol/L), increasing concentrations of tetrandrine (1 mumol/L, 10 mumol/L, 30 mumol/L and 100 mumol/L) showed dose dependent relaxation [(6.0 +/- 1.4)%, (21.3 +/- 2.2)%, (47.4 +/- 3.3)%, and (68.1 +/- 3.6)%, P < 0.01]. However, in the meantime, it was found that these relaxation effects were not affected by the presence of L-NNA and methylthioninium (P > 0.05). CONCLUSIONS: Tetrandrine was effective in relaxing rabbit corpus cavernosum tissue in vitro in a dose-dependent style. The mechanism might be related with its blocking effect on calcium channel, but not the NO-cGMP passage.

Alkaloids↗

PubMed2002

Influence of several uropathogenic microorganisms on human sperm motility parameters in vitro.

AIM: The effects of certain uropathogenic microorganisms (Neisseria gonorrhoeae, Staphylococcus aureus, Staphylococcus epidermidis and Mycobacterium tuberculosis) on human sperm motility characteristics were studied in vitro. METHODS: In 10 healthy fertile men, ejaculates were aseptically obtained by masturbation and with a swim-up technique, a sperm suspension of high motility and purity was obtained. Several uropathogenic bacteria were obtained from outpatients with genitourinary tract infections. The sperm suspension was incubated with the pathogens at a bacteria: sperm ratio of 50:1 at 37deg. The sperm mobility parameters were estimated with a computer-assisted sperm analyzer (CASA) provided with a multiple-exposure photography system (Madi Corp., Zhejiang, China). Measurements were carried out at 0, 2 and 4 hours of incubation. RESULTS: Staphylococcus aureus significantly decreased the sperm motility and viability, but Staphylococcus epidermidis, Mycobacterium tuberculosis and Neisseria gonorrhoeae did not. CONCLUSION: Staphylococcus aureus has an inhibitory effect on human sperm motility in vitro.

Gonorrhea↗

PubMed2002

Detection of Epstein-Barr virus in human colorectal cancer by in situ hybridazition.

OBJECTIVE: To investigate the relationship between Epstein-Barr virus (EBV) and the pathogenesis of human colorectal cancer. METHODS: The small-molecule RNA fragments of EBV was examined by in situ hybridization in colorectal cancer specimens obtained from 130 patients. RESULTS: EBV was found in the 6 of 130 colorectal cancer cases. EBV positivity was more prevalent in male patients (4/6), and the tumor tissues of the 4 EBV-positive cases were featured by obvious stromal infiltration by the lymphocytes (4/6). CONCLUSION: EBV infection might be related to the pathogenesis of some colorectal adenocarcinomas in China, and intensive lymphocyte infiltration in the stroma of the tumor tissues can be an important pathological indication of EBV infection in colorectal tumors.

Adult↗

PubMed2002

[Biological characteristics of rabbit corporal smooth muscle cells cultured in vitro].

OBJECTIVES: To study the biological characteristics of rabbit corporal smooth muscle cells (SMC) cultured in vitro. METHODS: In vitro tissue culture technique, morphological observation, cell counting, mitosis index and adhesion rate evaluation were applied to study the biological features of the SMC. RESULTS: 1. SMC were spindle-shaped and parallel along their longitudinal axis, showing obvious orientation. 2. The attachment and the proliferation of SMC in vitro were rapid. SMC cultured in vitro can grow and maintain their steady characteristics provided appropriate passage rate and culture condition. CONCLUSIONS: The SMC cultured in vitro are proved to be used to evaluate and investigate the effect of some medicine on penile erection.

Animals↗

PubMed2002

[Intercellular gap junctions in corporal smooth muscle].

The contractility of corporal smooth muscle plays a critical role in human penile erectile process. Understanding the initiation, maintenance and modulation of corporal smooth muscle tone is a prequisite to improve understanding, diagnosis and treatment of erectile dysfunction. Despite this fact, indentification of both the precise mechanistic basis by which various agents exert their effects on individual corporal smooth muscle cells, moreover, the process by which these signals are spread among the diverse array of parenchymal cells in the paired corporal, remain somewhat of a physiological enigma. Therefore, this article aims at: 1. to review current knowledge of the regulation of corporal smooth muscle tone at the cellular and molecular level; 2. to review various methods used in the study of gap junction channel.

Animals↗

PubMed2002

[Influence of protein kinase C on motility and acrosome reaction of sperm].

Protein kinase C (PKC) is localized in the equatorial segment and the principal piece of the tail of spermatozoa. Activator of PKC results in increasing flagellar motility of sperm that is blocked by PKC inhibitors such as staurosporine. A good correlation (r = 0.9, P < 0.001) is found between the content of PKC in sperm and sperm motility. Zona pellucida (ZP) stimulates the spermatozoa binding the acrosome reaction resulting in the release of hydrolytic enzymes and in the exposure of new membrane domains. ZP binding to receptors in the plasma membrane can regulate adenyl cyclase (AC) leading to elevation of cAMP and protein kinase A (PKA) activation. The PKA activates a voltage-dependent Ca2+ channel in the outer acrosomal membrane which releases Ca2+ from the interior of the acrosome to the cytosol. Activation of the PLC resulted from the rise in Ca2+ hydrolyze phosphatidyl inositol bisphosphate. The product activate PCK to open a voltage-dependent Ca2+ channel (L) in the plasma membrane, leading to the second (II) Ca2+ higher increase which result in membrane fusion and acrosome reaction. It is proposed that PKC would be involved in the regulation of motility and acrosome reaction of sperm.

Acrosome Reaction↗

PubMed2002

[Influence of dibutyryl cyclic adenosine monophosphate on motility of sperm].

OBJECTIVES: To investigate the influence of cAMP/PKA signal transduction on human sperm motility, and to study the effect of dibutyryl cyclic adenosine monophosphate dibutyryl cyclic adenosine monophosphate (dbcAMP) on human sperm motility in vitro. METHODS: Sperm aseptically obtained by masturbation and prepared by swim-up technique from 10 healthy fertile men were incubated with different concentrations of dbcAMP. Measurement of mobility were carried out at 20, 30, and 60 min in all specimens. RESULTS: The sperm treated with dbcAMP showed a significant increase in sperm progressive motility and the percentage of motile cells. The effect seemed enhanced with the increasing of dbcAMP concentration. VSL and VCL were not affected by dbcAMP. CONCLUSIONS: dbcAMP can activate the mobility of human sperm in vitro.

Adult↗

PubMed2002

[Influence of male genital bacterial infection on sperm function].

Male infertility is related to urogenital tract bacterial infection. The significance of bacteriosperimia for male infertility has been paid attention in recent years. Asymptomatic bacteriosperm may play an important role. However, litter is known about the adverse influence of some uropathogenic bacteria on sperm function. The article reviewed some uropathogenic bacteria in male urogential tract and several pathomechanisms of effect bacteria on sperm function.

Bacteria↗