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Biomedical subjects

Y Zhong

Publications and source records attributed to Y Zhong.

At least 91 records · Page 5Linked to original sources
PubMed1999

[Intermittent-pulse treatment of onychomycosis with orally administered itraconazole].

Fifty-four patients received an intermittent regimen of itraconazole (26 of them were finger onychomycosis and 28 toe onychomycosis) and were followed-up for nine months. The result showed that the clinical cure rate of fingernails was 88.5% and the mycologic cure rate was 96.4%, while the clinical cure rate of toes was 82.1% and the mycologic cure rate was 96.4%. Few adverse events were observed by 7.4%, just like nausea, gastric discomfort etc. It suggests that the pulse administration system is highly effective and has a few side-effects.

Adolescent↗
PubMed1999

[Studies on chemical constituents of the roots of Gypsophila oldhamiana Miq].

OBJECTIVE: To separate compounds from the root of Gypsophila oldhamiana. METHOD: Chemical and chromatographic methods were used to separate the compounds. IR, MS, NMR were used to determine the structures of compounds. RESULT: Compound pentacosanoic acid, lacceroic acid, beta-sitosterol, alpha-spinasterol, daucosterol and sucrose were identified. CONCLUSION: All the above compounds were obtained from this genus for the first time.

Caryophyllaceae↗
PubMed1999

Microvascular changes in the retrobulbar optic nerve in idiopathic intracranial hypertension.

PURPOSE: To examine the microvascular changes in the retrobulbar optic nerve in idiopathic intracranial hypertension (PTC). METHODS: Both optic nerves from a 29-year-old man with a two year history of PTC were examined histologically and morphometrically. A semi-automated image analysis system and paraphenylenediamine (PPD) stain were employed to resolve sufficiently the microvascular images for counts and measurement. RESULTS: There were 150 vessels distributed in the optic nerves which revealed the following: The average lumen of the vessels in outer sectors were larger than those of the inner sector vessels (168.17 microns 2 vs. 46.99 microns 2; p = 0.0338; OD; and 251.96 microns 2 vs. 130.02 microns 2; p = 0.029; OS) while in the normal control optic nerve the outer and inner area lumens were reversed in size-differential, but this did not show a statistical difference. The thickness of the PTC optic nerve vessel walls in the outer sectors was also greater than that of the walls in the inner sectors (4.95 microns vs. 2.67 microns; p = 0.013; OD and 5.25 microns vs. 3.34 microns; p = 0.019; OS); the same measurements in the normal optic nerve showed a reversed ratio, which was opposite that of the experimental group and but not statistically different. CONCLUSION: This pattern of microvascular changes is consistent with the selective axonal loss in the peripheral area of each optic nerve as much more severe than that in the inner sectors.

Adult↗
PubMed1999

[The preliminary study of amniotic membrane on TGF-beta 1 expression after photorefractive keratectomy].

OBJECTIVE: To investigate the effect of amniotic membrane on TGF-beta 1 expression after photorefractive keratectomy(PRK). METHODS: PRK was performed bilaterally on 6 New Zealand white rabbits. One eye was randomly tranplanted with preserved human amniotic membrane, and the other eye served as the control. The expression of TGF-beta 1 mRNA was detected with in situ hybridization at the 4th weeks after PRK. RESULTS: TGF-beta 1 mRNA expression was present in the corneal epithelium and stroma at the 4th weeks after PRK. The cornea in amniotic membrane transplanted group had also TGF-beta 1 mRNA expression, and the expression extent was less than that in control group (P < 0.05). CONCLUSION: Amniotic membrane can reduce the expression of TGF-beta 1 mRNA in cornea after PRK.

Amnion↗
PubMed1998

Pharmacological and molecular characterization of P2X receptors in rat pelvic ganglion neurons.

1. The presence and characteristics of P2X receptors on neurons of the rat major pelvic ganglia (MPG) have been studied using whole cell voltage-clamp, in situ hybridization and immunohistochemistry. 2. Rapid application of ATP (100 microM) to isolated rat MPG neurons induced moderately large inward currents (0.33-5.3 nA) in 39% of cells (108/277). The response to ATP occurred very rapidly, with an increase in membrane conductance, and desensitized slowly. 3. The concentration-response curve for ATP yielded an EC50 of 58.9 microM. The agonist profile was ATP> or =2MeSATP=ATPgammaS>BzATP, while alpha,beta-MeATP, beta,gamma-MeATP, UTP and ADP were all inactive at concentrations up to 100 microM. 4. The response to ATP was antagonized by suramin (pA2=5.6), reactive blue-2 (IC50=0.7 microM) and pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (PPADS). 5. Lowering the pH from 7.4 to 6.8 produced a marked potentiation (to 339% of control) of the responses to ATP (30 microM), while raising the pH to 8.0 attenuated the responses (to 20% of control). The EC50s for ATP were 28.8, 58.9 and 264 microM at pH 6.8, 7.4 and 8.0, respectively. 6. Co-application of ATP with Zn2+ produced a marked enhancement of the responses to ATP, with an EC50 of 9.55 microM. In the presence of Zn2+ (30 microM), the EC50 for ATP was decreased to 4.57 microM. 7. In situ hybridization revealed that the P2X receptor transcripts levels in rat MPG neurons are P2X2>P2X4>P2X1, P2X3, P2X5 and P2X6. The immunohistochemical staining revealed a small number of neurons with strong P2X2 immunoreactivity. 8. In conclusion, our results indicate that there are P2X receptors present on MPG neurons. The pharmacological characteristics of these receptors, the in situ hybridization and immunohistochemical evidence are consistent with them being of the P2X2 subtype, or heteromultimers. with P2X2 being the dominant component.

Adenosine Triphosphate↗
PubMed1998

[One stage repair of old Achilles tendon rupture accompanied by skin defect].

Old achilles tendon rupture accompanied by skin defect was a common & annoying problem in clinic. From June, 1985 to June, 1996, 18 cases with this kind of injury were treated by one stage repair of the tendon and skin defect. In this series, there were 15 males and 3 females, the length of tendon defects were ranged from 4 cm-6.1 cm, and the area of skin defect were ranged from 5.9 cm x 3 cm to 8.2 cm x 6 cm. The procedures were: (1) to debridement of the wound thoroughly; (2) to repair the achilles tendon; (3) to repair the skin defect with kinds of pedicle flap; (4) immobilization of ankle and knee for 6 weeks. No infection was occured after the operation. The flaps survived in all cases. After follow-up for one year in 15 cases, 12 patients went back to their work. It was concluded that (1) achilles tendon rupture should be treated carefully and properly during the emergency operation; (2) different methods should be selected according to the length of tendon defect; (3) because of its high survival and retained sensation after operation, the flap pedicled with posterior lateral malleolar artery is the best choice for repairing the skin defect.

Achilles Tendon↗
PubMed1998

[Study on the health of cotton mill workers].

A group of 110 workers in a cotton mill was investigated by questionnaire, skin testing, and the measurement of airway responsiveness through forced expiratory volume for one second(FEV1) by spirometry. The workers were examined before starting work, 10 weeks and one year after exposure. Decreases in FEV1 over shifts were small at 10 weeks and one year, and were slightly higher among people with positive skin reactions to cotton dust extracts. Airway responsiveness, defined as the average decrease in FEV1 after 1.25 mg methacholin, was increased at 10 weeks. It remained about the same after one year, except in the workers with positive skin test. Subjective symptoms of chest tightness and cough with phlegm increased progressively at 10 weeks and one year. Nasal irritation remained unchanged and dry cough decreased in one year. The results suggest that the airway inflammation caused by cotton dust increases with the exposure time and that the changes are more notable in workers with reactivity to cotton dust extract.

Adolescent↗
PubMed1998

[Experimental study of Yishou tiaozhi tablet on inhibiting hyperlipemia and atherosclerosis].

OBJECTIVE: To observe the effect of Yishou Tiaozhi tablet on lipid-metabolism and aortic intimal atherosclerotic plaque coverage in rabbit's model of experimental hyperlipemia and atherosclerosis. METHODS: Thirty-two rabbits were divided randomly into four groups, group A, B, C and D, 8 in each group. Forage with cholesterol and lipid plus 1.59 g/kg of Yishou Tiaozhi tablet was fed to the group A every day; to the group B, 22.54 mg/kg gypenoside tablet was added to forage with cholesterol and lipid; to the group C, forage with cholesterol and lipid was fed; and to the group D, ordinary forage only. Biochemical parameters were measured and pathomorphological examination were carried out 6 weeks later. RESULTS: (1) Yishou Tiaozhi tablet obviously lowered the levels of serum TC, TG, AI, ApoB, LP (a), ox-LDL, HYP, plasma Ca2+, TXB2 and increased the levels of serum HDL-ch, ApoA1, ApoA1/APoB, plasma 6-keto-PGF1 alpha(P < 0.01). (2) Pathomorphological examination showed that in the group A aortic intimal atherosclerotic plaque area and arterial intima thickness obviously reduced, smooth muscle cell hyperplasia and elastic fibers were not seen. CONCLUSION: Yishou Tiaozhi tablet can inhibit experimental hyperlipemia and atherogenesis. It is an ideal and effective medicine in preventing and treating hyperlipemia and atherosclerosis.

Animals↗
PubMed1998

[Chemical constituents of Phyllanthus urinaria L. and its antiviral activity against hepatitis B virus].

Studies on the chemical constituents of Phyllanthus urinaria and its antiviral activity against hepatitis B virus were completed. Eleven compounds have been isolated. Two of them are new compounds methyl ester dehydrochebulic acid and methyl brevifolin carboxylate. Antiviral experiments on HBsAg in vitro and liver damage caused by CCl4 have shown that. Phyllanthus urinaria possesses antiviral activities against HBV.

Animals↗
PubMed1998

[Degradation of phytic acid in rapeseed meal by two strains of molds].

By using selective media, two strains of molds which are able to degrade phytic acid were isolated from soil samples. These molds are able to use inositol as the sole carbon and energy sources for growth. In broth cultures, the degradation rates of phytic acid by these molds were 74.4% and 95.0%, respectively. However, in solid-state fermentation which used rapeseed meal as a raw material, the degradation rate was about 40%. Several metal ions tested were able to enhance the degradation rate of phytic acid. Factors such as temperature, pH and moisture content which affect the growth of molds were also explored. These two strains of molds were initially identified as Paecilomyces sp. and Penicillium sp.. They do not produce any detectable amount of aflatoxins.

Biodegradation, Environmental↗
PubMed1998

Serotonin-sensitive leakage channel in Drosophila central neurons.

This article reports the analysis of a novel serotonin (5-HT)-sensitive leak channel. The 5-HT responses were recorded in acutely dissociated Drosophila adult and larval central nervous system (CNS) neurons by the patch-clamp method, in an attempt to establish a model preparation suitable for the genetic study of signal transduction underlying central neurotransmission. Focal perfusion or iontophoresis of 5-HT onto some patched neurons induced either an apparent inward or outward current. This apparent outward current is able to cause a strong hyperpolarization of the neuron. This article focuses on the predominant hyperpolarizing response, which is observed in a significant fraction of larger CNS neurons and in different developmental stages. The hyperpolarizing response is in fact mediated by inhibiting an inward leak current, which has a reversal potential around 0 mV. This 5-HT-sensitive leak current appears to be mediated mainly by one type of newly identified leak channel with a similar reversal potential of 0 mV and a conductance of 24 pS. In addition, it was also demonstrated that neurotransmitter-induced responses in both larval and adult Drosophila CNS neurons can be analyzed in this acutely dissociated preparation.

Animals↗
PubMed1998

Development of a highly polymorphic STR marker for identity testing purposes at the human androgen receptor gene (HUMARA).

We developed a non-isotopic method which improves the technical quality of the X-linked HUMARA locus typing process. The use of formamide and a low concentration of acrylamide increased resolution and sharpness of HUMARA alleles in silver-stained polyacrylamide gels. In addition, the construction of an allelic ladder containing amplified sequence of 9 alleles (even-numbered alleles) of the HUMARA locus, allows confident, rapid and precise assignment of discretely defined alleles. Allele and genotype frequencies for the HUMARA locus were determined in a French Canadian population sample. Observed genotype frequencies in females conformed to Hardy-Weinberg expectations. Furthermore, the HUMARA locus is highly polymorphic with 18 observed alleles and an heterozygosity value of 89.3%. Also, this locus has average powers of discrimination of 97.8% and 88.7% for testing samples of female and male origin, respectively. In the French Canadian population, the average probability of excluding a random man as the father in paternity analysis when both mother and daughter are tested for this locus is 88.0%. Together, the results indicate that the HUMARA locus provides a highly discriminatory system that is appropriate for the purposes of forensic identification and paternity testing involving a female child.

Alleles↗
PubMed1997

Rescue of a Drosophila NF1 mutant phenotype by protein kinase A.

The neurofibromatosis type 1 (NF1) tumor suppressor protein is thought to restrict cell proliferation by functioning as a Ras-specific guanosine triphosphatase-activating protein. However, Drosophila homozygous for null mutations of an NF1 homolog showed no obvious signs of perturbed Ras1-mediated signaling. Loss of NF1 resulted in a reduction in size of larvae, pupae, and adults. This size defect was not modified by manipulating Ras1 signaling but was restored by expression of activated adenosine 3', 5'-monophosphate-dependent protein kinase (PKA). Thus, NF1 and PKA appear to interact in a pathway that controls the overall growth of Drosophila.

Amino Acid Sequence↗
PubMed1997

Requirement of Drosophila NF1 for activation of adenylyl cyclase by PACAP38-like neuropeptides.

The human neurofibromatosis type 1 (NF1) tumor suppressor protein functions as a Ras-specific guanosine triphosphatase-activating protein, but the identity of Ras- mediated pathways modulated by NF1 remains unknown. A study of Drosophila NF1 mutants revealed that NF1 is essential for the cellular response to the neuropeptide PACAP38 (pituitary adenylyl cyclase-activating polypeptide) at the neuromuscular junction. The peptide induced a 100-fold enhancement of potassium currents by activating the Ras-Raf and adenylyl cyclase-adenosine 3',5'-monophosphate (cAMP) pathways. This response was eliminated in NF1 mutants. NF1 appears to regulate the rutabaga-encoded adenylyl cyclase rather than the Ras-Raf pathway. Moreover, the NF1 defect was rescued by the exposure of cells to pharmacological treatment that increased concentrations of cAMP.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1997

A general method for tree-comparison based on subtree similarity and its use in a taxonomic database.

A number of metrics for comparing the branching structure of trees have been used as important tools in the quantitative analysis of evolutionary trees. Less attention has been paid to developing a general comparison methodology for different leaf-labeled N-trees such as classification trees and various types of dendrograms. In this paper a method for measuring overall similarity based on subtree similarity is proposed. Association coefficients can be used to measure the similarity between each pair of subtrees in two trees, and an algorithm called the 'webbing matrix method' is outlined in order to calculate the overall similarity in this method. In addition, the use of this method for tree searching and tree comparison in a taxonomic database is introduced.

Animals↗
PubMed1997

Interactions between loreclezole, chlormethiazole and pentobarbitone at GABA(A) receptors: functional and binding studies.

1. Interactions were investigated between loreclezole, chlormethiazole and pentobarbitone as potentiators of depolarization responses mediated by gamma-aminobutyric acid(A) (GABA(A)) receptors on afferent nerve terminals in the rat cuneate nucleus in vitro. These drugs were also compared as modulators of [3H]-flunitrazepam (FNZ) binding to synaptic membranes prepared from rat whole brain homogenate. 2. In rat cuneate nucleus slices, the drugs shifted muscimol log dose response lines to the left in an approximately parallel fashion with the result that 200 microM chlormethiazole potentiated muscimol responses by 0.567 +/- 0.037 log unit (mean +/- s.e.mean, n = 4) while loreclezole gave a maximal potentiation at 10 microM of only 0.121 +/- 0.037 (n=6) log unit and 0.071 +/- 0.039 (n=22) at 50 microM. 3. While 50 microM chlormethiazole and 30 microM pentobarbitone showed no significant interactions between each other when potentiating muscimol responses in combination, 50 microM loreclezole in combination with either chlormethiazole or pentobarbitone attenuated their potentiating effects, possibly by inducing desensitization of GABA(A) receptors. 4. In the [3H]-FNZ binding studies on well-washed membranes, loreclezole enhanced binding to a maximum of 47.3 +/- 2.83% of control (mean +/- s.e.mean, n = 3) at 300 microM. Scatchard analysis revealed no change in Bmax but a decrease in K(D) for [3H]-FNZ from 3.9 +/- 0.29 nM to 2.7 +/- 0.10 nM (mean +/- s.e.mean, n=4) in the presence of 100 microM loreclezole. In contrast, 100 microM chlormethiazole caused no potentiation. A small component of the enhancement by loreclezole could be blocked by 100 microM bicuculline and could also be blocked by 100 microM chlormethiazole. It seems likely that the effects on [3H]-FNZ binding are due predominantly to direct actions of the drugs on the GABA(A) receptor and are separate from the GABA-potentiating effects. 5. The results indicate distinctly different profiles of action for loreclezole, chlormethiazole and pentobarbitone on GABA(A) receptors.

Animals↗