Biomedical subjects

Z Yu

Publications and source records attributed to Z Yu.

At least 163 records · Page 9Linked to original sources

PubMed1999

[Survey on traditional medicinal resources of Uncaria distributed in China].

OBJECTIVE: To make clear the botanical origin of medicinal Uncaria distributed in China and the situation of its use in folk medicines. METHODS: Collecting data and making on-the-spot investigation. RESULTS: There are thirteen medicinal plants which belong to Uncaria genus, and ten of them are commercially available. A clear idea was obtained of their geographical distribution, distribution features and practical experiences in folk application. CONCLUSION: This investigation is helpful in further researching and exploring the resources of Uncaria for medical use, as well as provides a scientific basis for production, management and safe use of crude drugs.

China↗

PubMed1999

[Morphological changes of external eyes before and after blepharoplasty].

OBJECTIVE: To discuss the morphological changes of external eyes before and after blepharoplasty. METHODS: A survey of 92 patients treated by blepharoplasty was carried out to compare the external eye morphology of pre-operation with that of post-operation. RESULTS: It was found significant differences in the post-operative patients, including the increased length and height of eyelids, and obvious changes of the length and angle of the exposed eyelashes. CONCLUSION: Blepharoplasty makes the eyelashes exposed and held up, and increases the up-to-low distance of eyelids. These changes promote the beauty of eyes.

Adolescent↗

PubMed1999

[Ectopic meningiomas of the head and neck (report of 10 cases)].

OBJECTIVE: To study the diagnosis and treatment of ectopic meningiomas of the head and neck. METHOD: A retrospective review was made of 10 patients with ectopic meningiomas of the head and neck, the pathological diagnosis was as follows: 2 case epithelial type, 2 case psammomatous type, 1 case transitional type, 1 case malignant meningioma and types of another 4 cases were unknown. RESULT: All patients were treated surgically, 4 patients with local recurrence were operated secondarily and no signs were observed with the follow-up of many years. CONCLUSION: Surgery was the choice of ectopic meningiomas of the head and neck.

Adolescent↗

PubMed1999

[Chiral separation of thio-glycidyl ether on amylose-chiral stationary phase by high performance liquid chromatography].

In the present study, we synthesized amylose-tris(phenylcarbamate), and used it as chiral stationary phase based on silica gel. This stationary phase offered a practically useful chiral separation medium. Amylose was allowed to react with an excess of phenylisocyanate in pyridine for 48 h. The obtained carbamate was dissolved in DMF and adsorbed on silica gel previously treated with 3-aminopropyltriethoxysilane. The mass ratio of the carbamate to the silica gel was 0.45/2.55. The four thio-glycidyl ethers were resolved on the amylose tris(phenylcarbamate) chiral stationary phase. Separation was carried out with a hexane/2-propanol mixture as mobile phase at a flow rate of 1.0 mL/min at room temperature. The effects of 2-propanol concentration on the retention and resolution have been investigated.

Amylose↗

PubMed1999

[Gas chromatographic method for estimating chemical stability of nitroquanidine propellant].

This paper describes a GC analytical method for nitroquanidine propellant instead of the tranditional methylviolet method. Operating conditions were as follows: TDX-01 packed column, 150-200 mesh, 800 mm x 3 mm i.d., at 150-170 degrees C with TCD. Released gases, CO2 and N2O contents in a sealed vessel packed with nitroquanidine were calculated according to the normalization of corrected peak areas of air, CO2 and N2O. Thus, the change in the chemical stability of nitroquanidine during the period of storage and thermal aging could be observed.

English Abstract↗

PubMed1999

[Chiral separation of thioglycidyl ether and glycidylselenide on cyclodextrin bonded stationary phase via high performance liquid chromatography].

beta- Cyclodextrin bonded chiral stationary phases (CD-CSP) were prepared after the method of Armstrong (CD-CSP I) and of Huang Tianbao (CD-CSP II). With the separation of o-, m- p-nitroaniline, it was found that the chromatographic properties of CD-CSP II was superior to that of CD-CSP I. Three racemes of thioglycidyl ethers and two racemes of glycidylselenides were resolved on CD-CSP II via high performance liquid chromatography. The mobile phase consisted of different volume ratios of methanol/0.3% triethylammonium acetate buffer solution(pH 5), and the eluate was detected with a UV-visible detector at a wavelength of 254 nm. With the increase of methanol volume ratio in the mobile phase, the retention time decreased rapidly, but within the range of methanol valume ratio 40/100 to 50/100, the separation factor only decreased slightly. The racemes examined contained aromatic groups and hydroxy groups which can form inclusion complexes and hydrogen bonding interactions with beta-cyclodextrin. The chiral separation of the racemes is successful with the mobile phase of V(methanol):V(buffer) = 40:60.

Aniline Compounds↗

PubMed1999

[Preliminary study of P19 gene from Bacillus thuringiensis subsp israelensis].

The P19 gene and cyt1A gene were obtained by PCR with 9.7 kb HindIII fragment containing P19 gene and cyt1A gene from 72 MD plasmid of Bt as a template. Digested PCR products were ligated to expression vector pUHE24 and transformed into E. coli XL-1. Three clones, LZ19 harboring P19 gene, LZcyt1A harboring cyt1A gene, LZ19A harboring P19 gene and cyt1A gene, were screened. The growth cure of cloned strains were determined under IPTG induction. The result showed that pLZ19 did not affect the growth of E. coli, pLZcyt1A is typically Lethal for E. coli, Lethal initial efficiency of pLZ19A is much higher than that of pLZcyt1A. Probably, this was a result that P19 gene enhanced initial expression of cyt1A gene in E. coli.

Bacillus thuringiensis↗

PubMed1999

[The effect of N+ implantation on SOD activity of Deinococcus radiodurans and induction of Mn-SOD].

The induction of Mn-SOD and effect of N+ of 20 keV implantation on SOD activity of D. radiodurans were investigated. The results were as follows: (1) SOD activity of D. radiodurans had a little change when implantation dose was less than 8 x 10(14) N+/cm2, and increased gradually from 8 x 10(14) to 60 x 10(14) N+/cm2, and then decreased rapidly; (2) the test of adding H2O2 and CHCl3-CH3CH2OH which could inhibit different types of SOD showed that most SOD activity of D. radiodurans was constituted by Fe-SOD in general physiology and less then 8 x 10(14)N+/cm2 dose, and higher implantation dose induced increase of Mn-SOD activity.

Deinococcus↗

PubMed1999

[Effects of the water-soluble extracts from the single herb of ganduqing against hepatitis B virus in vitro].

Comparing with Ara-Amp, the effects of the water-soluble extracts from the single herb of the formula for Ganduqing on HBeAg and HBsAg expression in 2.2.15 cells were studied. The results showed that the extracts of Serissa serissoides (DC) Druce, Hibiseus mutabilis Linn, Paedeuia scangens (Lour) Merr var tomentosa (BL) Hand-Mazz, Plumbago zeylanica L, Garcinia oblougifolia Champ and Begpnia edulia Levl had marked inhibition effects on HBeAg and HBsAg which expressed by 2.2.15 cells.

Antiviral Agents↗

PubMed1999

[Inhibiting effects of the ethanol-soluble extracts from the dried rhizoma of Garcinia oblougififolia on hepatitis B virus in vitro].

Comparing with Ara-Amp, the effects of the ethano-soluble extracts from the dried rhizoma of Garcinia oblougififolia Champ (GOC) on HBeAg and HBsAg expression in 2.2.15 cells, which came from transfected HepG2 cells with coloned HBV DNA, were studied. The results showed that the extracts of GOC had a marked inhibition effects on HBeAg adn HBsAg which expressed by 2.2.15 cells, the effective concentration was range from 195 to 780 micrograms/ml.

Antiviral Agents↗

PubMed1999

[Preservation of laryngeal function in surgical treatment of hypopharyngeal carcinoma].

OBJECTIVE: To study of the feasibility, the surgical techniques and the results of laryngeal function preservation in surgical treatment of hypopharyngeal carcinoma. METHODS: A retrospective review of 305 (279 males, 26 females, ages ranging from 14 to 77 years) cases with malignant neoplasms of the hypopharynx that were treated from 1978 to 1996 were accomplished. Of the 305 (stage I, 6; II, 12; III, 82; IV, 205) cases, 234 were originated from pyriform sinus, 21 from postcricoid, 35 from posterior pharyngeal wall and 15 from superior hypopharynx. Two hundred and eighty-five patients received 55-75 Gy postoperative radiotherapy. RESULTS: The overall 5 year survival rate of 305 patients was 44.8%; for stage I, the survival rate was 83%; stage II, 71%; stage III, 58% and stage IV, 36.5%. Of the 305 patients, 206 cases (67.54%, stage I, 6; II, 12; III, 65; IV, 123) were surgically treated with laryngeal functions preserved and 99 (32.46%, stage III, 17; IV, 82) total laryngectomy. There were no significant differences in 5-year survival between the functionally preserved group and none functional group. Among the 206 functional preserved patients, 139(67.5%) had all functions preserved (voice, respiration and deglutition) and 67(32.5%) partially preserved (voice and deglutition). CONCLUSION: Only a few patients (31/305, 10%) of hypopharyngeal carcinomas require total laryngectomy, and the preservation of the normal part of the larynx is feasible for the eradication of tumor and preservation of laryngeal function.

Adolescent↗

PubMed1999

[Immunohistochemical evaluation of micrometastases to cervical lymph nodes in supraglottic cancer].

OBJECTIVE: Supraglottic carcinomas of larynx tends to metastasize to cervical lymph nodes. The regular pathological method of diagnosis is easy to have the micrometastasis missed, and serial-sectioning is too difficult be used in the regular pathological examinations. The aim of this study was to evaluate the value of immunohistochemical assay in the detection of micrometastasis. METHODS: Monoclonal antibodies against cytokeratin (AE1/AE3) were used to detect the cervical lymph nodes of 46 cases (50 sides of neck) of supraglottic carcinoma with pathologically negative findings (pN0). RESULTS: Micrometastases were identified in 13 lymph nodes of 11 cases. CONCLUSION: It is suggested that the detection of lymph node micrometastases with immunohistochemical method is more sensitive than that of regular pathologic method. It is comparable to serial sectioning. Therefore, It is a valuable clinical method to detect the early lymph node metastasis.

Adult↗

PubMed1998

Abrupt climate oscillations during the last deglaciation in central north america

Evidence from stable isotopes and a variety of proxies from two Ontario lakes demonstrate that many of the late glacial-to-early Holocene events that are well known from the North Atlantic seaboard, such as the Gerzensee-Killarney Oscillation (also known as the Intra-Allerod Cold Period), Younger Dryas, and Preboreal Oscillation, also occurred in central North America. These results thus imply that climatic forcing acted in the same manner in both regions and that atmospheric circulation played an important role in the propagation of these events.

Journal Article↗

PubMed1998

Effects of pentachlorophenol, pentylenetetrazol and carnitine on mitochondria.

Pentachlorophenol (PCP) increased oxygen consumption and lowered the respiratory control ratio (RCR) in mitochondria from rat liver. These effects of PCP were lessened by 1 mM L-carnitine but not by D-carnitine. In contrast, up to 150 mM of pentylenetetrazol (PTZ) added at state 4 of respiration did not accelerate oxygen consumption. When mitochondria were incubated with 3.3 mM of PTZ, oxygen consumption, RCR and ADP/O ratio were all decreased. Moreover, these could not be suppressed even by high concentrations (-20 mM) of L-carnitine. Thus, while L-carnitine could suppress effects of PCP, it could not counteract PTZ in mitochondria. It appears that anticonvulsive effects of carnitine in PTZ-induced seizures may not be due to mitochondrial protection.

Animals↗

PubMed1998

Supersensitivity to serotonin- and histamine-induced arterial contraction following ovariectomy.

The modulating role of estrogens and ovariectomy on coronary artery and thoracic aortic rings was examined in female rabbits. Three treatment groups were studied: (1) control, (2) ovariectomy, and (3) ovariectomy + 17beta-estradiol acetate (40 microg/kg per day, i.m. for 7 days). Coronary artery reactivity was studied in the isolated retrogradely perfused heart. Aortic reactivity was studied using endothelium intact and denuded aortic rings. Concentration-response curves were performed to serotonin (5-HT) and histamine. A 21-fold, a 4.7-fold, and a 5.2-fold increase in sensitivity to 5-HT-induced contraction were observed in the ovariectomy group compared to the control group for coronary artery, intact aortic, and denuded aortic preparations, respectively (P < 0.05 for each comparison). Similarly, 34-fold, 4.9-fold, and 5.0-fold increases in sensitivity to histamine-induced contraction were observed in the ovariectomy group compared to control group for coronary artery, intact aortic, and denuded aortic preparations, respectively (P < 0.05 for each comparison). 17beta-Estradiol administration reversed the supersensitivity to serotonin- and histamine-induced vascular contraction observed following ovariectomy. No differences in EC50 or maximal contraction were noted between control and ovariectomy + estrogen groups. Baseline nitric oxide release and maximal 5-HT- and histamine-induced nitric oxide release from the perfused heart were decreased (P < 0.05) in ovariectomy rabbits compared to control and ovariectomy + estrogen treatment groups. The data demonstrate that (1) reduced autacoid-induced nitrous oxide release following ovariectomy and (2) direct effects upon the vascular smooth muscle contractility, which are probably mediated by altered receptor sensitivity by ovariectomy and estrogen replacement therapy. The information obtained from this study provides additional information regarding possible beneficial actions of estrogen replacement therapy in post-menopausal women.

Acetylcholine↗

PubMed1998

Electrochemical analysis of protein nitrotyrosine and dityrosine in the Alzheimer brain indicates region-specific accumulation.

HPLC with electrochemical array detection (HPLC-ECD) was used to quantify 3,3'-dityrosine (diTyr) and 3-nitrotyrosine (3-NO2-Tyr) in four regions of the human brain that are differentially affected in Alzheimer's disease (AD). DiTyr and 3-NO2-Tyr levels were elevated consistently in the hippocampus and neocortical regions of the AD brain and in ventricular cerebrospinal fluid (VF), reaching quantities five- to eightfold greater than mean concentrations in brain and VF of cognitively normal subjects. Uric acid, a proposed peroxynitrite scavenger, was decreased globally in the AD brain and VF. The results suggest that AD pathogenesis may involve the activation of oxidant-producing inflammatory enzyme systems, including nitric oxide synthase.

Aged↗

PubMed1998

Tight-binding streptavidin ligands from a cyclic peptide library.

During the screening of a soluble library of cyclo(AXXXXXAE)K-CONH2, a cyclic peptide cyclo(AHPQFPAE)K-CONH2 was identified as a tight-binding ligand (IC50 = 128 nM) and found to bind 1000-fold more tightly than its linear peptide to streptavidin. The results of this study suggest that library screening of conformationally constrained cyclic peptides can be an effective means for the discovery of high affinity ligands.

Amino Acid Sequence↗

PubMed1998

A chemically modified tetracycline inhibits streptozotocin-induced diabetic depression of skin collagen synthesis and steady-state type I procollagen mRNA.

Wasting of connective tissues including skin, bone, and cartilage have been closely associated with elevated matrix metalloproteinase (MMP) activity and depressed collagen content in the streptozotocin (STZ)-induced diabetic rat, while tetracyclines have been reported to normalize total body weight, skin hydroxyproline and collagen content in this model, in part through inhibition of MMPs. In the present study, we report the effect of CMT-1, a chemically modified tetracycline that lacks antimicrobial properties but retains divalent cation binding and MMP inhibitory activity, on diabetic skin collagen synthesis and steady-state levels of procollagen alpha 1(I) mRNA. Male, 4-month old Sprague-Dawley rats received a single injection of 75 mg/kg STZ or citrate vehicle alone and diabetic status was confirmed by positive glucosuria. Some diabetic animals received 10 mg/day of CMT-1 by oral gavage and, 28 days after STZ treatment, body weight, blood glucose values and the in vivo rates of skin collagen production were measured using the pool-expansion technique. Steady-state levels of procollagen alpha 1(I) mRNA were analyzed 21 days after STZ treatment by hybridization of total RNA with a 32P labelled cDNA to rat type I procollagen alpha 1(I) mRNA in a dot-blot assay. STZ treatment was found to significantly depress body weight, skin collagen hydroxyproline content, the in vivo rate of collagen production, and hybridizable levels of type I procollagen alpha 1(I) mRNA. CMT-1 administered daily to STZ-treated rats inhibited the diabetic depression of these parameters but had little or no effect on non-diabetic controls or on STZ-induced hyperglycemia. Thus, in addition to the inhibition of MMP mediated extracellular collagen degradation, these results suggest CMT-1 also acts to inhibit diabetic connective tissue breakdown in STZ-induced diabetes by increasing both steady-state levels of type I procollagen mRNA and collagen synthesis through mechanism(s) that are independent of the antibacterial properties of tetracyclines.

Animals↗