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Biomedical subjects

W Y Li

Publications and source records attributed to W Y Li.

At least 19 recordsLinked to original sources
PubMed2007

Ethyl acetate extract of Chinese medicinal herb Sarcandra glabra induces growth inhibition on human leukemic HL-60 cells, associated with cell cycle arrest and up-regulation of pro-apoptotic Bax/Bcl-2 ratio.

Sarcandra glabra (Thunb.) Nakai, colloquially known as Caoshanhu, is a Chinese medicinal herb with reported anti-tumor, anti-inflammatory, anti-viral and non-specific immunoenhancing properties. Although the plant has been clinically used for treating a variety of diseases, its bioactive ingredients are largely unknown and its mode of action has never been investigated. In this study, the anti-tumor property of ethyl acetate (EA) extract of S. glabra was investigated by determining its in vitro growth-inhibitory effects on a panel of human cancer cell lines of different histotypes. Growth inhibition of the EA extract on the cancer cells seemed to be selective, and the leukemic HL-60 was found to be the most responsive after 48 h of treatment (IC50=58 microg/ml). Flow cytometric studies further illustrated that the extract might interfere with DNA replication and thus arrested the cell cycle at S phase in the leukemic cells, followed by DNA fragmentation and loss of phospholipid asymmetry in the plasma membrane after 72 h of treatment. Concurrently, the pro-apoptotic Bax/Bcl-2 ratio was also up-regulated by more than 178% of the control level. All these findings suggested that the extract had initiated apoptosis to kill the leukemic cells. Results from this pioneer study help to establish a scientific foundation for future research and development of the bioactive ingredients in EA extract of S. glabra as efficacious anti-cancer agents.

Acetates↗
PubMed2005

Local anesthesia for functional endoscopic sinus surgery employing small volumes of epinephrine-containing solutions of lidocaine produces profound hypotension.

BACKGROUND: Local anesthetic containing epinephrine is commonly used in many operations for the main purpose of hemostasis. A randomized, controlled, prospective clinical trial was designed to find out hemodynamic changes after local infiltration of different concentrations and/or different dosages of epinephrine during functional endoscopic sinus surgery (FESS) under general anesthesia. METHODS: One hundred and eight adult patients undergoing elective FESS under general anesthesia were randomly allocated into four groups. Group I received 2% lidocaine 2 ml with epinephrine (5 microg/ml); group II received 1% lidocaine 4 ml with epinephrine (2.5 microg/ml); group III received 1% lidocaine 4 ml with epinephrine (5 microg/ml); and group IV received 1% lidocaine 4 ml for local infiltration. Heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP) were monitored continuously in the radial artery and recorded in 6 min: before infiltration (baseline), 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 5, and 6 min after local infiltration. The lowest blood pressure (BP) in this period was also recorded. RESULTS: Significant hemodynamic changes, particularly a decrease in BP (P < 0.001) with a slight increase in HR (P < 0.001) at approximately 1.5 min and an increase in SBP at approximately 3 min (P < 0.01) after local infiltration, were observed in group I, group II and group III compared with the baseline, but not in group IV. No significant hemodynamic differences were observed between group I, group II and group III at the same time points (P > 0.05). CONCLUSION: Local infiltration of low-dose epinephrine causes temporary significant hemodynamic changes particularly a marked decrease in BP during FESS under general anesthesia.

Adolescent↗
PubMed2004

Ketamine inhibits LPS-induced calcium elevation and NF-kappa B activation in monocytes.

OBJECTIVE: To investigate whether ketamine could inhibit lipopolysaccharide (LPS)-induced intracellular calcium elevation and NF-kappa B activation in monocytes. MATERIALS AND METHODS: Isolated rat monocytes were challenged with 10 microg/ml LPS with or without the presence of various concentrations of ketamine (10, 100, 1000 microM). Intracellular calcium was monitored by laser confocal microscopy. NF-kappa B activity of the nuclear extracts of monocytes was analyzed by electrophoretic mobility shift assay (EMSA). RESULTS: LPS provoked a significant calcium elevation and enhanced NF-kappa B activity in monocytes. Ketamine above concentration of 100 microM inhibited endotoxin-induced intracellular calcium elevation and NF-kappa B activity. Ketamine itself had no effect on either of them. CONCLUSIONS: These findings suggest that ketamine could suppress NF-kappa B in monocytes exposed to endotoxin, and this anti-inflammatory effect might act through attenuating intracellular calcium elevation.

Animals↗
PubMed2004

Interrelationship between methionine and cystine of early Peking ducklings.

A 4 x 5 factorial experiment containing 4 cystine levels (0.325, 0.406, 0.487, or 0.568%) and 5 methionine levels (0.285, 0.385, 0.485, 0.585, or 0.685%) was conducted to evaluate the interrelationship between methionine and cystine in corn-peanut meal diet for Peking ducklings from hatch to 21 d of age. Eight hundred 1-d-old male white Peking ducklings were assigned to 20 experimental treatments. All treatments were replicated 4 times using 10 ducklings per pen. As dietary methionine level increased, weight gain and feed intake increased and then decreased; the quadratic response of weight gain was significant (P < 0.05). The methionine requirement for maximum efficiency of feed utilization (0.585%) was higher than for maximum weight gain (0.485%). According to the quadratic model, the optimal methionine requirement of Peking ducklings from hatch to 21 d of age was 0.481% (95% of the level at maximum response). The plasma uric acid concentration was very low (P < 0.05) when dietary methionine was 0.485%. When dietary methionine was excessive (0.685%), the plasma homocysteine concentration increased (P < 0.05). On the other hand, the cystine requirement of ducklings from hatch to 21 d of age was not more than 0.325%. A high level of cystine (0.568%) depressed weight gain and feed intake (P < 0.05), but cystine supplementation in the diets lowered the plasma homocysteine concentration (P < 0.05). There were no significant interactions between methionine and cystine on growth performance, plasma uric acid, and plasma homocysteine.

Animal Feed↗
PubMed2004

Candida tropicalis-associated bilateral renal papillary necrosis and emphysematous pyelonephritis.

Although the kidney is often involved in disseminated and localized candidiasis, bilateral emphysematous pyelonephritis (EPN) is infrequently reported. Renal papillary necrosis (RPN) caused by fungi is also rare. We describe a patient with bilateral RPN and EPN caused by Candida tropicalis, who suffered from recurrent hematuria, flank pain, acute fulminant renal failure, and obstruction by a sloughed papilla. He was treated successfully with antifungal therapy and percutaneous nephrostomy (PCN). This is the first case report of C. tropicalis-associated EPN and RPN.

Adult↗
PubMed2003

Reliability of pre-operative biopsies in the histological grading of colorectal adenocarcinomas.

BACKGROUND: Management of colorectal cancer depends on many patient and tumour variables. Decisions are sometimes based on the histological grade of tumour as assessed by initial biopsy. This retrospective study looked at the reliability of grading colorectal cancer from pre-operative biopsies. METHODS: 118 patients with a diagnosis of colorectal cancer, who had adequate pre-operative biopsies, were included in the study. A single consultant histopathologist re-examined all the preoperative biopsy slides, but was blinded to the final grading of the resection specimen. RESULTS: Of the 118 resection specimens, 41 were graded well-differentiated, 52 moderately differentiated and 25 poorly differentiated. When compared with postoperative grading, 37 (31%) initial biopsies were undergraded, 49 (43%) were correctly graded and 32 (26%) were overgraded. CONCLUSIONS: These results suggest that the histological grading of pre-operative specimens is inaccurate and should be used with caution to determine treatment. The difficulty with grading pre-operative biopsies in colorectal cancer may be owing to a lack of specific criteria such as is used in, for example, breast cancer.

Adenocarcinoma↗
PubMed2003

Microdochectomy in women aged over 50 years.

Management of a spontaneous single duct nipple discharge without associated mass and normal mammography remains controversial. Our study examined the pathological results of 52 women of all ages treated with microdochectomy for single duct nipple discharge. Malignant or premalignant lesions were identified in 1 patient under 50 years of age and 2 patients over 50 years. Papilloma was the most frequently identified pathology in both age groups (60% of patients under 50 years and 73% over or equal to 50 years of age). Our results suggest that microdochectomy is a safe effective treatment in women aged over 50 years.

Adult↗
PubMed2002

Improving glandular coverage during prostate biopsy using a long-core needle: technical performance of an end-cutting needle.

OBJECTIVE: To compare the technical performance of a 33-mm core-length biopsy needle with that of the standard 18 mm needle, as many prostate cancers are isoechoic and in large prostates the tissue coverage with the 18 mm needle is inadequate. PATIENTS AND METHODS: A 33-mm core length BioPince VSL disposable needle (Amedic, Sweden) and a standard TruCut 18 mm needle (Medical Device Technology Inc., FL, USA) were used to take prostatic biopsies in two groups of 15 patients. The following variables were assessed for each group: mean core length, core quality, capsular coverage (one or both capsules within the specimen), and side-effects in the first week after biopsy (for the BioPince group, surveyed using a self-completed questionnaire). The results were compared with historical data from a group of 30 patients biopsied using the standard needle. RESULTS: For the BioPince and standard groups the mean (sd) core length was 19.4 (8.9) and 14.9 (5.1) mm, respectively. Four needles in the BioPince group failed to capture a sample, requiring needle replacement. The samples were fragmented in 15 of 90 (17%) and 41 of 90 (46%) biopsies in the BioPince and standard groups, respectively (P < 0.05). Specimens had both capsules present in five of 90 (6%) and four of 90 (4%), respectively. Within 7 days minor bleeding was the most common side-effect. Pain after biopsy was the only symptom showing a significant difference between the groups, at six of 15 and none (P = 0.001), respectively. The incidence of haematuria, haematospermia and rectal bleeding was similar in the two groups (P > 0.05), but fever more common (three vs none) in the BioPince group (P = 0.06). CONCLUSION: When set at a 33-mm stroke length, the BioPince needle increases the mean core length by 30%, with less fragmentation than a standard 18 mm needle. However, it has a significant failure rate for capture (27% needle replacement rate), slightly greater morbidity (pain and possibly fever) and shows no advantage in capsular coverage. Therefore, there are shortcomings with this end-cutting needle when used at 33 mm core length.

Aged↗
PubMed2002

Medullary thyroid carcinoma: a rare presentation as a hypervascular tumour.

Sporadic medullary thyroid carcinoma (MTC) usually presents with a thyroid mass, cervical lymphadenopathy or other local cervical symptoms. Often the diagnosis is unsuspected pre-operatively. We report a unique case of a mixed follicular medullary thyroid carcinoma presenting as a tumour with extreme vascularity. The management of hypervascular thyroid tumours is discussed together with current controversies regarding persistent hypercalcitoninaemia.

Arteries↗
PubMed2001

Functional gamma-secretase inhibitors reduce beta-amyloid peptide levels in brain.

Converging lines of evidence implicate the beta-amyloid peptide (Ass) as causative in Alzheimer's disease. We describe a novel class of compounds that reduce A beta production by functionally inhibiting gamma-secretase, the activity responsible for the carboxy-terminal cleavage required for A beta production. These molecules are active in both 293 HEK cells and neuronal cultures, and exert their effect upon A beta production without affecting protein secretion, most notably in the secreted forms of the amyloid precursor protein (APP). Oral administration of one of these compounds, N-[N-(3,5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester, to mice transgenic for human APP(V717F) reduces brain levels of Ass in a dose-dependent manner within 3 h. These studies represent the first demonstration of a reduction of brain A beta in vivo. Development of such novel functional gamma-secretase inhibitors will enable a clinical examination of the A beta hypothesis that Ass peptide drives the neuropathology observed in Alzheimer's disease.

Administration, Oral↗
PubMed2000

Suppression of an amyloid beta peptide-mediated calcium channel response by a secreted beta-amyloid precursor protein.

Secreted isoforms of the beta-amyloid precursor protein potently enhance neuronal survival in cell cultures exposed to toxic amyloid beta peptide. Lowering of intracellular calcium levels to offset the increases in intraneuronal calcium caused by amyloid beta peptide is thought to underly this neuroprotection. Because we have shown previously that an amyloid beta peptide-mediated potentiation of calcium channel currents may contribute to this cytosolic calcium overload, the present study examined the effects of a secreted beta-amyloid precursor protein on the calcium channel response to amyloid beta peptide. When compared with untreated cultured rat hippocampal neurons, cells that underwent a 24 h preincubation with beta-amyloid precursor protein 751 displayed decreases in the relative size of the calcium channel response to amyloid beta peptide. A membrane-permeable analog of cyclic GMP, a second messenger believed to be involved in the calcium regulation process mediated by beta-amyloid precursor proteins, also attenuated the modulatory calcium channel response. Co-application of beta-amyloid precursor protein 751 with amyloid beta peptide did not alter calcium channel response to amyloid beta peptide. Taken together, these findings suggest that secreted beta-amyloid precursor proteins can suppress a calcium channel response to amyloid beta peptide that is potentially injurious to the cell, and as such, may define a neuroprotective mechanism that is specific for amyloid beta toxicity.

Amyloid beta-Peptides↗
PubMed2000

Mollusc-algal chloroplast endosymbiosis. Photosynthesis, thylakoid protein maintenance, and chloroplast gene expression continue for many months in the absence of the algal nucleus.

Early in its life cycle, the marine mollusc Elysia chlorotica Gould forms an intracellular endosymbiotic association with chloroplasts of the chromophytic alga Vaucheria litorea C. Agardh. As a result, the dark green sea slug can be sustained in culture solely by photoautotrophic CO(2) fixation for at least 9 months if provided with only light and a source of CO(2). Here we demonstrate that the sea slug symbiont chloroplasts maintain photosynthetic oxygen evolution and electron transport activity through photosystems I and II for several months in the absence of any external algal food supply. This activity is correlated to the maintenance of functional levels of chloroplast-encoded photosystem proteins, due in part at least to de novo protein synthesis of chloroplast proteins in the sea slug. Levels of at least one putative algal nuclear encoded protein, a light-harvesting complex protein homolog, were also maintained throughout the 9-month culture period. The chloroplast genome of V. litorea was found to be 119.1 kb, similar to that of other chromophytic algae. Southern analysis and polymerase chain reaction did not detect an algal nuclear genome in the slug, in agreement with earlier microscopic observations. Therefore, the maintenance of photosynthetic activity in the captured chloroplasts is regulated solely by the algal chloroplast and animal nuclear genomes.

Algal Proteins↗
PubMed2000

Clinical significance of serum soluble interleukin 2 receptor-alpha in esophageal squamous cell carcinoma.

Although the serum level of soluble interleukin-2 receptor alpha (sIL-2Ralpha) has been shown to correlate with progression and prognosis of several cancers, data to support its clinical significance to esophageal squamous cell carcinoma (ESCC) are limited. This study was conducted to assess the prognostic value and source of sIL-2Ralpha in patients with ESCC. From January 1986 to June 1997, 125 patients with histopathologically confirmed ESCC were enrolled for study. Ninety-three patients underwent en bloc esophagectomy, and 32 patients with unresectable tumor underwent palliative surgery. Four (4.3%; 4 of 93) patients died of surgical complications. Serum levels of sIL-2Ralpha were measured by ELISA. Expression of IL-2Ralpha, IL-2Rbeta, and IL-2Rgamma in the pathological section was determined, respectively, by immunohistochemistry (IHC) and in situ hybridization (ISH). Compared with the healthy control group (1020 +/-476 pg/ml, n = 103), ESCC patients tended to have significantly higher serum sIL-2Ralpha concentrations (1424 +/- 798 pg/ml, n = 121). The sIL-2Ralpha level was correlated with age, Tumor-Node-Metastasis classification, tumor stage, reading score of the IHC staining, and survival but not with the pathological grade or lymphovascular invasion. Prognosis was worse for patients with high sIL-2Ralpha levels (> or =1500 pg/ml) than for those with low serum sIL-2Ralpha levels (< 1500 pg/ml; P = 0.0209). It can be used as an independent prognostic factor of ESCC. In the pathological sections, expression of IL-2Ralpha, IL-2Rbeta, and IL-2Rgamma was detected in 17 (18.1%), 83 (89.2%), and 83 (89.2%) cases, respectively, by IHC, and the message of IL-2Ralpha was identified in tumor cells by ISH in 30.1% (28 of 93) of the cases. Serum concentrations of sIL-2Ralpha are frequently elevated in ESCC patients and are correlated with disease progression and survival. These data indicate that, in addition to activated T cells, cancer cells could be an important source of sIL-2Ralpha in ESCC patients.

Aged↗
PubMed2000

[Nasopharyngeal stenosis following uvulopalatopharyngoplasty].

OBJECTIVE: To report nasopharyngeal stenosis following UPPP and our treatment experience. METHOD: Two clinical cases were analysised. RESULT: In this paper, the complications were attributed to excessive excision palapharyngeal arches, which juried mucous membrane of nasopharyngeal inlet during the long management time as bleeding and the laser used. Surgical management was performed in two cases. One failed. One was treated successfully by rotation palato-pharyngeal flap and prolonged nasopharyngeal stent, Follow-up 20 months there was no recurrence of stenosis. CONCLUSION: Surgical correction of nasopharyngeal stenosis following UPPP is challenging and the best treatment is prevention.

Constriction, Pathologic↗
PubMed2000

[Application of capillary chromatography in benzene boiling range analysis].

The experimental data were analyzed by regression analytical method and the relation between the quantity of impurities and the boiling range of benzene was demonstrated. It was proved that when the quantity of hydrocarbon impurities was within certain limits, the quality of benzene fractions can be determined by analyzing the hydrocarbon impurities in it. So the distillation method for analyzing benzene boiling range may be replaced by capillary chromatography for analyzing the hydrocarbon impurities. The practical applications support the above suggestion.

English Abstract↗
PubMed2000

[Revision endoscopic sinus surgery for recurrent nasal polyps].

OBJECTIVE: To study the surgical effect and experience of revision endoscopic sinus surgery for the patients with recurrent nasal polyps. METHOD: From Jul. 1997 to Oct. 1998, a subset of 21 cases with recurrent nasal polyps had been operated by the way of revision endoscopic sinus surgery. All the patients were operated bilaterally at the same time. The operation type included: total ethmoidectomy or sub-total ethmoidectomy, maxillary natural orifice enlargement and maxillary sinus pathological changes tissue eliminated by canine fossa access. RESULT: We have followed these patients for 6-12 months and evaluated surgical effect: 7 cases of 21 were cured, 8 were improved, 6 were of no effect, and the total effective rate was 71.4%. There are not any heavy complications in this subset. CONCLUSION: Revision endoscopic sinus surgery is an effective way for recurrent nasal polyps patients, six anatomic marks proposed by May will do good for us to resect the pathological changes tissue thoroughly and prevent heavy complications as could as possible.

Adolescent↗
PubMed1999

Phase I study of AG 331, a novel thymidylate synthase inhibitor, in patients with refractory solid tumors.

PURPOSE: This was a phase I study of AG 331 to determine systemic tolerance and pharmacokinetics following single and multiple escalating intravenous doses. METHODS: The study was an open-label phase I trial that was divided into two components. In phase IA (single dose), six dose levels from 12.5 to 225 mg/m2 were administered to 18 patients (3 at each dose level) and serial blood samples were collected for 72 h. Upon achieving satisfactory pharmacologic parameters, the multiple dosing component (phase IB) was initiated. Six dose levels from 50 to 800 mg/m2 per day were administered for 5 consecutive days to 18 patients. Pre- and postdose blood samples were obtained on days 1-4 and serial blood samples were collected over 24 h following dose 5. Nonhematologic and hepatic toxicities were assessed, serum AG 331 concentrations were measured and pharmacokinetic parameters determined. RESULTS: Other than fatigue, no severe toxicities were encountered in phase IA. Liver toxicity was manifested by elevations in transaminase first noted at multiple doses of 200 mg/m2 per day for 5 days. Fever and malaise but no myelosuppression were noted. The mean terminal t1/2 following single doses was significantly shorter than the t1/2 following multiple dosing (6.8 vs 9.9 h) and clearance was significantly faster following single doses than following multiple dosing (81.7 vs 30.4 l/h), but no significant difference in Vd was noted. CONCLUSIONS: The dose-related toxicity profile precludes further clinical development at this time. The pharmacokinetics of AG 331 following single and multiple doses showed significant differences.

Adult↗