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Biomedical subjects

W Ji

Publications and source records attributed to W Ji.

At least 37 records · Page 2Linked to original sources
PubMed2001

[The clinical and pathological research of supraglottic carcinoma with bilateral cervical nodal metastasis].

OBJECTIVE: To evaluate clinical and pathological characteristics in patients with supraglottic carcinoma and bilateral cervical nodal metastasis. METHOD: 60 patients with supraglottic carcinoma treated in this hospital from 1985 to 1994 were retrospectively reviewed, including 30 cases with bilateral metastasis (experiment group) and 30 cases with unilateral metastasis (control group). The two groups were contrasted according to site of tumor, tumor diameter, surface morphology, clinical staging, the degree of invading the contralateral semilarynx, Border's grading, growth mode of tumor edge, the degree of invading preepiglottic space. RESULT: In stage T4 cases with low grading of cell differentiation made up 63.6% (7/11) in the bilateral metastasis group, while 10% in the ipsilateral metastasis group (P < 0.05). Significant differences lied between N0 group and N2 group (P < 0.05). Moderate and severe invasion of contralateral semilarynx in the bilateral group made up 87.5% (14/16), significantly higher than that in ipsilateral group 53.3% (16/30). CONCLUSION: Bilateral neck dissection should be used in T4 cases with low grading of cell differentiation in which the contralateral semilarynx was invaded. Bilateral neck dissection should be taken for the treatment of supraglottic carcinoma with N2.3 diseases. Bilateral neck dissection is recommended for the patients with moderate and severe invasion of the contralateral semilarynx.

Adult↗
PubMed2000

Effect of antibiotics on development in vitro of hamster pronucleate ova.

Antibiotics are commonly added to embryo culture media, but effects on embryo development have not been examined thoroughly. Hamster ova were used to investigate whether penicillin, streptomycin or gentamicin affect embryo development in vitro. Ova were collected 10 h post activation by spermatozoa in vivo and cultured in five treatments: 1) CONTROL: chemically-defined medium HECM-9 with no antibiotics; 2) HECM-9 with 100 IU/mL penicillin; 3) HECM-9 with 50 microg/mL streptomycin; 4) HECM-9 with 10 microg/mL gentamicin and 5) HECM-9 with both 100 IU/mL penicillin and 50 microg/mL streptomycin. Individually, penicillin, streptomycin and gentamicin did not affect embryo development to the 8-cell stage at 58 h post oocyte activation, or morula/blastocyst stages, or blastocysts alone at 82 h post activation. However, when penicillin and streptomycin were both present in the culture medium the percentages of 8-cell embryos at 58 h and blastocysts at 82 h were significantly lower than the control. No antibiotic treatment improved hamster embryo development in vitro. We caution against the use of penicillin and streptomycin together for hamster embryo culture, and show that it is not necessary to include any antibiotics in embryo culture media for up to 72 h if proper sterile technique is used with an oil overlay.

Animals↗
PubMed2000

Development of zona-free hamster ova to blastocysts in vitro.

The zona pellucida (ZP) enclosing the mammalian ovum is important for its protection and for initial stages of fertilization, but the role of the ZP during embryo development is less clear. This study was designed to investigate if the hamster ZP is needed for embryo development from 1-cell to blastocyst in vitro, and to compare methods for removing the ZP. A total of 395 hamster pronucleate ova were collected 10 h post activation from superovulated, mated female hamsters. The ZP was removed from some ova using either 0.05% pronase, 0.05% trypsin or acid Tyrode's solution. To prevent ZP-free ova from sticking together, they were cultured singly in 30-50 microL drops of HECM-6 culture medium together with ZP-intact ova as controls. There was no significant difference among treatment groups in embryo development to blastocyst: 36/87 (42%) in the ZP intact group; 35/75 (47%) in the pronase-treated ZP-free group; 37/74 (50%) in the trypsin-treated ZP-free group; and 37/71 (52%) in the acid-treated ZP-free group. These results indicate that 1) the ZP is unnecessary for hamster embryo development in vitro from the pronucleate ovum stage to blastocyst; 2) none of the three ZP-removal methods was detrimental to embryo development; 3) embryos do not need to be cultured in groups during in vitro development from 1-cell to blastocyst.

Animals↗
PubMed2000

Determination of diclofenac sodium by capillary zone electrophoresis with electrochemical detection.

Capillary zone electrophoresis was employed for the determination of diclofenac sodium using an end-column amperometric detection with a carbon fiber microelectrode, at a constant potential of 0.83 V vs. saturated calomel electrode. The optimum conditions of separation and detection are 4.90 x 10(-3) mol/l Na2HPO4-3.10 x 10(-3) mol/l NaH2PO4 (pH 7.0) for the buffer solution, 10 kV for the separation voltage, 5 kV and 10 s for the injection voltage and the injection time, respectively. The limit of detection is 2.5 x 10(-6) mol/l or 5.2 fmol (S/N=2). The relative standard deviation is 0.8% for the migration time and 4.7% for the electrophoretic peak current. The method was applied to the determination of diclofenac sodium in human urine.

Diclofenac↗
PubMed2000

Cryopreservation of rhesus macaque (Macaca mulatta) spermatozoa and their functional assessment by in vitro fertilization.

Although spermatozoa from several species of nonhuman primates have been cryopreserved, there has been no report of success with rhesus macaque spermatozoa as judged by functional assays. Two Tris--egg yolk freezing media, TEST and TTE, which have been successfully used for cynomolgus macaque (Macaca fascicularis) spermatozoa, were compared for cryopreservation of spermatozoa from four rhesus macaques (Macaca mulatta). The postthaw motility (percentage and duration) of spermatozoa cryopreserved in TTE was much higher than that for spermatozoa cryopreserved in TEST. The function of sperm cryopreserved in TTE was evaluated by in vitro fertilization of oocytes collected from gonadotropin-stimulated prepubertal rhesus macaques. Of the inseminated oocytes, 82 +/- 13% were fertilized and 63 +/- 22 and 39 +/- 21% of the resulting zygotes developed into morulae and blastocysts, respectively. These results indicate that rhesus macaque spermatozoa can be effectively cryopreserved in TTE medium. This finding will facilitate the application of in vivo and in vitro assisted reproductive technologies in this species.

Animals↗
PubMed2000

A 500-kb region on chromosome 16p13.1 contains the pseudoxanthoma elasticum locus: high-resolution mapping and genomic structure.

We have recently mapped the genetic defect underlying pseudoxanthoma elasticum (PXE), an inherited disorder characterized by progressive calcification of elastic fibers in skin, eye, and cardiovascular system, to chromosome 16p 13.1. Here we report further data on the fine-mapping and genomic structure of this locus. Haplotype analysis of informative PXE families narrowed the locus to an interval of less than 500 kb located between markers D16B9621 and D16S764. Three overlapping YAC clones were found to cover this region through YAC-STS content mapping. An overlapping BAC contig was then constructed to cover this interval and the surrounding region. About 80% of this chromosomal region has been fully sequenced using the BAC shotgun technique. Gene content and sequence analysis predicted four genes (MRP1, MRP6, PM5, and a novel transcript) and two pseudogenes (ARA and PKDI) within this interval. By screening a somatic cell hybrid panel we were able to precision-map the breakpoint of Cy185 and the starting point of a chromosomal duplication within 20 kb of BAC A962B4. The present data further refine the localization of PXE, provide additional physical cloning resources, and will aid in the eventual identification of the genetic defect causing PXE.

Adult↗
PubMed2000

Mutations of the gene encoding the transmembrane transporter protein ABC-C6 cause pseudoxanthoma elasticum.

We recently published the precise chromosomal localization on chromosome 16p13.1 of the genetic defect underlying pseudoxanthoma elasticum (PXE), an inherited disorder characterized by progressive calcification of elastic fibers in skin, eye, and the cardiovascular system. Here we report the identification of mutations in the gene encoding the transmembrane transporter protein, ABC-C6 (also known as MRP-6), one of the four genes located in the region of linkage, as cause of the disease. Sequence analysis in four independent consanguineous families from Switzerland, Mexico, and South Africa and in one non-consanguineous family from the United States demonstrated several different mis-sense mutations to cosegregate with the disease phenotype. These findings are consistent with the conclusion that PXE is a recessive disorder that displays allelic heterogeneity, which may explain the considerable phenotypic variance characteristic of the disorder.

ATP-Binding Cassette Transporters↗
PubMed2000

Preservation of gene expression ratios among multiple complex cDNAs after PCR amplification: application to differential gene expression studies.

Comparative gene expression studies are often limited by low availability of tissue and poor quality of extractable mRNA. Collective PCR amplification of minute quantities of mRNA has great potential for overcoming these limitations. However, there remains significant concern about the effects of amplification on the absolute and relative abundance of individual mRNAs that could complicate subsequent gene expression studies. To address this problem, we systematically compared the relative abundance of many specific mRNAs from complex cDNA preparations (from tissue and cultured cells) both before and after amplification by PCR. Our results demonstrated that, as expected, the absolute abundance of different mRNAs in a cDNA library is altered in an unpredictable manner by PCR amplification. However, we found that the concentration ratios of specific mRNAs among different cDNA preparations were routinely well conserved after PCR amplification. Thus, for the purpose of comparative expression studies for specific mRNAs in two (or more) complex cDNAs, PCR-amplified cDNA is equally useful as unamplified cDNA. These results provide a rigorous experimental validation and offer a theoretical treatment to support the utility of PCR amplified cDNA for differential gene expression studies. We conclude that the inherent difficulties in performing differential screening studies such as gene chip and array analyses on limited amounts of biological materials can be overcome by a PCR amplification step without compromising data quality.

Base Sequence↗
PubMed2000

Molecular ecology and biological control: the mating system of a marsupial pest.

Many studies in molecular ecology have focused on the use of repeat DNA markers to determine the nature of mating systems in a wide variety of animal species. Whilst these studies typically have focused on important issues such as the evolutionary consequences of fitness variation among males, genetic studies of mating systems are potentially also important because they can generate information of significance to wider issues in wildlife management. For example, genetically modified, sexually transmitted viral diseases have been suggested as potential agents for the control of vertebrate pest species. An understanding of the epidemiology of such agents requires an intimate knowledge of the sexual contact rates between individuals of the target species. Here, we report the use of minisatellite DNA profiling to reveal the mating system in two New Zealand populations of the introduced Australian brushtail possum. The brushtail possum is New Zealand's most important mammalian pest and a species for which control by a sexually transmitted immunocontraceptive has been proposed. Encouragingly, we report considerable variation in the reproductive success of males at both study sites, with one male siring offspring from four females in one year (mean no. of offspring/reproductively successful male/year at the two sites is 1.95-2.15), while many sired none. This bias in the pattern of reproductive success among males will probably facilitate the spread of an immunocontraceptive agent and thereby increase the power of this approach to biological control.

Animals↗
PubMed2000

[Study on the extraction of isofavones in rhizoma belamcandae].

In orthogonal tests, five factors were evaluted which were ethanol concentration, ethanol quantity, diameter of drug powder, reflux time and repetition times. Consideration of industrial produce, the optimal extraction was A2B2C3D2E2. That is 4-20 meshes drug powder refluxed with 70% ethanol which was 6 times weight of powder for 1 hour, repeated 2 times.

Analysis of Variance↗
PubMed2000

[Horizontal-vertical hemilaryngectomy for advanced laryngeal cancer].

OBJECTIVE: To evaluate the adequacy of horizontal-vertical partial laryngectomy in the treatment of advanced laryngeal cancer. METHODS: We retrospectively reviewed 57 patients with advanced laryngeal cancer (T3 or T4 on the primary site) treated by horizontal-vertical hemilaryngectomy. Fifty-six patients underwent neck dissections. RESULTS: The overall 3- and 5-year survival rates were 70% (40/57) and 64% (32/50), respectively. All patients had good phonation and resumed mouth-feeding after surgery. Among all the deaths, 4 died of recurrence of laryngeal cancer, 4 cervical metastasis, 4 distant metastasis, 2 intercurrent disease and 3 unknown. Of 36 patients with N0 neck, fifteen cases (15/36, 41.6%) had lymph node metastases pathologically. CONCLUSION: Horizontal-vertical hemilaryngectomy is satisfactory for the treatment of selected advanced laryngeal cancers. It also preserves laryngeal functions in most cases.

Adult↗
PubMed2000

[Long-term follow-up result of partial laryngectomy].

OBJECTIVE: To study the long-term follow-up result of partial laryngectomy and reservation of laryngeal function. METHODS: Three hundred and seventy-nine patients who underwent partial laryngectomy from 1986 to 1995 were summarized (male 290 cases, female 89 cases). Among them, 184 cases were supraglottic carcinomas (T1 8 cases, T2 115, T3 48, T4 13, according to UICC in 1992), 192 cases were glottic carcinomas (T1 115, T2 63, T3 13, T4 1), 3 cases were transglottic carcinomas (T2 1, T3 2). In common 8 kinds of operations were performed: 26 cases underwent cordectomy, 138 vertical laryngectomy, 7 frontolateral laryngectomy, 12 horizontal glottic laryngectomy (middle part of the larynx), 58 supraglottic laryngectomy, 95 horizontovertical (3/4) laryngectomy, 24 subtotal laryngectomy with cricoglossoepiglottic anastomosis, 19 near-total laryngectomy with cricoglossal anastomosis (with reservation of unilateral arytenoid cartilage). 193 cases underwent concurrent neck dissection(121 unilateral, 72 bilateral). RESULTS: All cases restored their phonation and overcame aspiration with removing nasal feeding from 7 to 23 days after operations. 362 cases were decannulated from 9 days to 3 months after operations. Another 8 cases were decannulated after a secondary plastic operation. Decannulation rate was 97.6%. The three, five and ten year survival rates were 86.8% (329/379), 81.3% (266/327) and 69.4% (120/173) respectively. CONCLUSION: Partial laryngectomy is a kind of radical operation with reservation of laryngeal function. Mastering indications strictly, correct operation choices, excellent surgical skills and perfect repairing technique are bases of improving life qualities and curative effect.

Adult↗
PubMed2000

[Clinical characteristics of different cordectomy types with potassium titanium phosphate laser].

OBJECTIVE: To study the clinical characteristics of different potassium titanium phosphate(KTP) laser types and surgical the recuperating course of cordectomy under suspension laryngoscope. METHOD: Follow-up observation were applied on 76 patients with cordectomy. Restoration of laryngeal structure and change of the quality of voice were observed and recorded. RESULTS: Type 1, normal laryngeal structure and function were restored postoperatively after 3 months; Type 2, a fold like vocal cord (new vocal cord) appeared 3 months later. Laryngeal structure was basically restored; Type 3, a mucosal fold appeared postoperatively after 6 months in most patients, but it lost motion function. Recurrence time was mainly found 2-4 months. Recurrence rate was 6.7%. Two and 5-year survival rate were 100%. CONCLUSIONS: Cordectomy with KTP laser can result in good effect and less injury. Type 2, 3 can retain thyroarytenoid muscle as much as possible on the basis of radical cure.

Adult↗
PubMed2000

[Study of mechanisms of lightening aspiration and increasing decannulation rate in anastomosis of cricoid cartilage and base of tongue (epiglottis)].

OBJECTIVE: To study laryngopharyngeal anastomosis and fixing methods of super-cricoid laryngectomy with reconstruction of functions in lightening aspiration and increasing decannulation rate. METHODS: Recovering conditions of laryngeal functions in 66 patients who underwent supracricoid laryngectomy and anastomosis of cricoid cartilage and base of tongue (epiglottis) in recent eight years were summarized. Some relevant caliber distances in 21 residual larynges were measured. RESULTS: All cases restored their phonation. In 36 cases that underwent anastomosis of cricoid cartilage and base of tongue, 15 cases without aspiration, 18 with mild aspiration, 3 moderates. Decannulation rate is 94.4%. In 30 cases who underwent anastomosis of cricoid cartilage and base of tongue, 10 with mild aspiration, 17 moderate, 3 serious. All cases overcame aspiration within 3 weeks. 7 cases were cannulated. 3, 5, 10 year survival rates were 80.3%, 74.4%, and 3/7. The longitudinal and transverse calibers of epiglottis were 1.5-2.0 times longer than that of the entrance of cricoid cartilage. After anastomosis of cricoid cartilage and base of tongue (epiglottis), the epiglottis can exactly cover the entrance of cricoid cartilage to prevent aspiration fully and increase decannulation rate. Previously the cricoid cartilage was anatomized and fixed under the hyoid bone. Because some spaces exist between cricoid cartilage, base of tongue and epiglottis, aspiration is likely to occur. That hyoid bone covers the entrance of cricoid cartilage will bring constriction of the new laryngeal orifice and make decannulation difficult. Hyoidectomy and anastomosis of cricoid cartilage and base of tongue (epiglottis) overcame the two shortcomings and had good effects. CONCLUSION: Cricoid-hyoid-anastomosis was the main reason of severe aspiration and low decannulation rate. The ideal methods to lighten aspiration and increase decannulation rate are hyoidectomy and anastomosis of cricoid cartilage and base of tongue (epiglottis).

Adult↗
PubMed1999

Synthesis of 5-(carboranylalkylmercapto)-2'-deoxyuridines and 3-(carboranylalkyl)thymidines and their evaluation as substrates for human thymidine kinases 1 and 2.

Derivatives of thymidine containing o-carboranylalkyl groups at the N-3 position and derivatives of 2'-deoxyuridine containing o-carboranylalkylmercapto groups at the C-5 position were synthesized. The alkyl spacers consist of 4-8 methylene units. The synthesis of the former compounds required 3-4 reaction steps in up to 75% overall yield and that of the latter 9-10 reaction steps with significantly lower overall yield. Derivatives of thymidine substituted with carboranylalkyl substituents at the N-3 position and short spacers were phosphorylated by both recombinant and purified cytosolic thymidine kinase (TK1) to a relatively high degree. None of the tested 2'-deoxyuridine derivatives possessing carboranyl substituents at the C-5 position were phosphorylated by either recombinant or purified TK1. The amounts of phosphorylation product detected for some of the C-5-substituted nucleosides with recombinant mitochondrial thymidine kinase (TK2) were low but significant and decreased with increasing lengths of the alkyl spacer. The data obtained in this study do not seem to support the tether concept applied in the synthesis of the new C-5- and N-3-substituted carboranyl nucleosides intended to reduce possible steric interference in the binding of carboranyl nucleosides with deoxynucleoside kinases. Instead, it appeared that a closer proximity of the bulky carborane moiety to the nucleoside scaffold resulted in better substrate characteristics.

Boron Compounds↗
PubMed1999

Synthesis and biological evaluation of boron-containing polyamines as potential agents for neutron capture therapy of brain tumors.

New boron-containing spermidine/spermine (SPD/SPM) analogues have been synthesized: N5-[4-(2-aminoethyl-o-carboranyl)butyl] and N5-{4-[(2,3-dihydroxypropyl)-o-carboranyl]butyl} SPD/SPM derivatives (ASPD-5, ASPM-5, DHSPD-5, and DHSPM-5) as well as N5-{[4-(dihydroxyboryl)phenyl]methyl}spermidine (BBSPD-5). These boronated polyamines retain their ability to displace ethidium bromide from calf thymus DNA and are rapidly taken up in vitro by F98 rat glioma cells. The in vitro toxicities of ASPD-5, ASPM-5, DHSPD-5, and DHSPM-5 are lower than those previously reported for N5-[4-(o-carboranyl)butyl] SPD/SPM derivatives (SPD-5 and SPM-5) but similar to those of native SPD and SPM. Very low toxicity was also observed for BBSPD-5. In vivo studies of ASPD-5 and BBSPD-5 were performed in mice bearing intracerebral implants of the GL261 glioma and subcutaneous implants of the B16 melanoma. The biodistribution data found in both tumor models suggest that the polyamines synthesized to date do not appear to be suitable boron agents for BNCT.

Animals↗