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Biomedical subjects

W Li

Publications and source records attributed to W Li.

At least 649 records · Page 36Linked to original sources
PubMed1999

[Studies on immunoprotection of monoclonal antibodies against Cryptosporidium parvum].

AIM: To explore the immune protection of the monoclonal antibody (McAb) against Cryptosporidium parvum. METHODS: On the basis of Madin-Darby canine kidney (MDCK) cell culture, the immunoprotection of McAb against C. parvum was screened by means of neutralization test in vitro, and verified by rat model and transmission electron microscopy of infected MDCK cells. RESULTS: The number of C. parvum sporozoites recovered on the surface of rat intestinal epithelial cells and the mean output of oocyst were significantly reduced by McAb Z3D2 (P < 0.001, P < 0.05). The decreased Cryptos poridium at each development phase within infected MDCK cells and less damage of cell ultrastructure caused by Cryptosporidium were found in Z3D2 treated group. CONCLUSION: McAb Z3D2 possesses highly effective protection against C. parvum.

Animals↗
PubMed1999

[Pharyngoscopic observation during sleep in patients with obstructive sleep apnea syndrome].

OBJECTIVE: To analyse collapse sites of pharynx and their anatomical causes during sleep in patients with obstructive sleep apnea syndrome(OSAS), and compared with the results of Muller's maneuver. METHODS: The pharynges in 43 sleeping patients with OSAS were examined endoscopically. The area changes at each segment(velo-, oro- and hypopharynges) were calculated during the episodes of apnea. A site having greater than 75% narrowing of airway lumen was defined as a narrowing or obstructive site. RESULTS: 1. All patients had obstruction at velopharynx during asleep. Airway collapses at multiple sites in 79% of cases(28% at velo- and oropharynx; 21% at velo- and hypopharynges; and 30% at velo-, oro- and hypopharynges). 2. At each segment the anatomical factors causing obstruction were variable among patients. The common abnormalities were posterior displacement of soft palate or uvula, enlarged tonsil, thicken or posterior displacement of tongue base, collapse of pharyngeal wall, redundant mucosa or lateral bands of pharynx etc. 3. The positivity of pharyngeal obstruction was higher in this study as compared with of Muller's maneuver the latter was taken place while the patient was awaken. Comparison of the positive rate of the narrowing sites determined between sleep observation and Muller's maneuver in same patients: at velopharynx(100% vs 91%), at oropharynx (58% vs 42%) and at hyperpharynx (51% vs 28%). CONCLUSION: Multiple obstructions in the pharynx are common. Examination of the pharynx during asleep may be more accurate then while the patient was awaken.

Female↗
PubMed1999

[Laryngotracheobronchial involvement in relapsing polychondritis].

OBJECTIVE: To investigate the clinical cause, treatments and prognosis of laryngotracheobronchial involvement in relapsing polychondritis (RP). METHODS: Thirteen patients of RP with laryngotracheobronchial involvement were review retrospectively. RESULTS: From 1983 to 1998, 20 patients with RP were managed in this hospital. Of them, 13 (65%) involving the laryngotracheobronchial region were observed. Respiratory tract lesions might be diffuse or localized and occurred in larynx (46%), trachea (69%) and bronchus (69%). Corticosteroids, immunosuppressive agents and dapsone were used in these patients. Tracheotomy was performed in 4 patients with airway obstruction. Montgomery T-tube or self-expanding metal stent were used in 2 patients with tracheal collapse. Of 13 case, 2 died from respiratory complications. The 5-years survival rate was 78.6%. CONCLUSION: Respiratory tract involvement is the most severe manifestation of the relapsing polychondritis and the main cause of death despite aggressive medical therapy or tracheotomy.

Adrenal Cortex Hormones↗
PubMed1999

[The manufacture and clinical use of the auto-sialographic instrument by remote controlling]

OBJECTIVE:The purpose of this article is to realize the auto-control of the injection of radiographic drugs in terms of the principle in remote controlling.METHODS:30 cases of sialaden diseases was studied using the auto sialographic instrument by remote controlling,compared to 67 cases studied using sialography by hand-controlling.RESULTS:The auto-sialographic instrument by remote controlling realize the telecontrol of the injection of the sialographic drugs and auto-injection,simplify the working procedure,and prevent medical staffs from X-ray radiation at work.CONCLUSION:The auto sialographic instrument by remote controlling can not only bring much convenience to medical staffs,but also improve the conformation to clinical diagnosis.

Journal Article↗
PubMed1999

[Determination of 14 rare earth impurities in Y2O3 by petroleum sulfoxide extraction chromatography].

Petroleum sulfoxide-NH4SCN extraction chromatography was developed for the separation of Y from other rare earth elements. Some chromatographic parameters were chosen and separation factors between Y and other rare earth elements were determined. A column of resin coated with petroleum sulfoxide was used. The Y in the sample was eluted with NH4SCN, then titrated with EDTA. The recovery was 67%-120% and relative standard deviation +/- 4.0%-19.4%. This method can be applied to the determination of trace amounts of rare earth impurities in Y2O3 with a purity of 99.9999%-99.99999%.

English Abstract↗
PubMed1999

[Determination of rare-earth impurities in ultra-highly pure Er2O3 and Ho2O3 by [HEH(HEP)] extraction chromatography-atomic emission spectrometry].

This article applied [HEH(HEP)] (2-ethyhexyldrogen-2-ethylhexyl phosphonate) extraction chromatography to separate 14 rare earth impurities from ultra-highly pure Er2O3 and Ho2O3, and then the impurities were determined by atomic emission spectrometry. The average percentage recovery for each element is in the range of 70%-140%. The relative standard deviations of the determination are +/- 3.3%-2.2%. This method can be applied to the determination of the trace amounts of rare eath impurities in Er2O3 and Ho2O3 with a purity of 99.9999%-99.99999%.

English Abstract↗
PubMed1999

[Interatomic distances of molecule for orthohydrogen and parahydrogen].

The determination of rotational Raman spectra for hydrogen gas at 354.9, 587.4, 814.7 and 1035.1 cm(-1) by FT-Raman spectrometry is described in this paper. The Raman bands at 354.9 and 814.7 cm(-1) were assigned to rotational levels J = 0 --> J = 2 and J = 2 --> J = 4 for parahydrogen, and those at 587.4 and 1035.1 cm(-1) were assigned to rotational levels J = 1 --> J = 3 and J = 3 --> J = 5 for orthohydrogen. The interatomic distances determined for orthohydrogen and parahydrogen molecules with nonrigid rotator model are 75.03 and 74.98 pm, respectively.

English Abstract↗
PubMed1999

[Synthesis and characterization of lanthanum(III) with O-chlorophenoxyacetic acid].

This work has synthesized a binary solid complex using rare earth ion La3+ with the ligand HL (HL = O-chlorophenoxyacetic acid). The chemical formula of the complex was determined to be LaL3 x H2O by elemental analysis. The composition, structure and properties of this type of complex were tentatiovely investigated by the analysis of molar conductivity, IR, UV, TG-DTA and 1H NMR. The center ion in the complex was considered to be chelated by a bidentate ligand HL.

English Abstract↗
PubMed1999

[Study of conformation of serum albumin by FTIR].

This paper used the FTIR method to study the spectra of bovine serum albumin (BSA) and its solution. The secondary structure and conformation was assigned by FTIR-deconvolution analysis. The result indicated that BSA secondary structure in solid is different from in aqueous solution. As the decrease of BSA concentration from 3.241 x 10(-1) to 4.032 X 10(-2) g X mL(-1), the amide I band components at 1 609.84, 1 633.85,1 653.69, 1 681.16 and 1 694.88 cm(-1) shifted to 1 608. 24, 1 638.36, 1 656.10, 1 674.87 and 1 690.78 cm(-1), respectively, the component at 1 621.50 cm(-1) unchanged.

Animals↗
PubMed1999

[Synthesis and characterization of complex La(C5O3H3)3 x C12H8N2 x H2O].

The title ternary complex La(C5O3H3)3 x C12H8N2 x H2O was synthesized by reaction of lanthanum nitrate with alpha-furoic acid (C5O3H4) and 1,10-phenanthroline (C12H8N2) as ligand in the alcohol solvent. The composition of the complex was determined by element analysis. Its structure and properties were characterized by IR, 1H NMR, UV and TG-DTA. IR, 1H NMR, UV spectra showed that the ligand alpha-furoic acid coordinate to the center ion La (III) with the deprotonized form, and 1, 10-10phenanthroline with the bidentate form using its two N atoms. The TG-DTA analysis exhibited that the complex is stable in the range of room temperature and undergo the disassociation of water and oxygenized decomposition of the organic ligands in order with the rising of temperature, and the final oxide obtained is La2O3. The quantitative analysis of TG-DTA was coincided with the structural composition of the title complex.

English Abstract↗
PubMed1999

Crowding in central and eccentric vision: the effects of contour interaction and attention.

PURPOSE: To quantify the crowding effect with eccentric stimuli and to determine the relative contribution of neural interaction and attention to crowding in central and eccentric vision. METHODS: Monocular visual acuity was measured with computer-generated tumbling E and Landolt C targets presented centrally or at 2 degrees in the right visual field. Crowding distractors were designed to cause increasing contour interaction or increasing need for focused attention. A four-alternative forced-choice method of constant stimuli was used. In experiment 2 the distance between the target and the distractors was varied. RESULTS: Data are presented in terms of normalized visual acuity. Crowding in central vision was minimal, mainly caused by contour interaction, and did not occur with distractors more than four stroke widths distant. Crowding in eccentric vision was far greater in magnitude and extent (occurring for distractors as far as 16 stroke widths distant) and was caused by contour interaction and attentional factors. CONCLUSIONS: The results indicate that eccentric vision differs quantitatively and qualitatively from central vision. The extent of contour interaction effects are consistent with the proposed size of cortical processing zones. The results are discussed with reference to current theories of preattentive and attentive tasks and with reference to subjects with low vision due to central scotoma who use an eccentric retinal locus for fixation.

Adult↗
PubMed1998

Systemic administration of anti-interleukin-10 antibody prolongs organ allograft survival in normal and presensitized recipients.

BACKGROUND: Systemic administration of cellular interleukin (IL)-10 at a dose of 100 microg/day for 1 week after transplantation accelerates mouse cardiac allograft rejection across MHC barriers. This effect is associated with enhancement of donor-specific cytotoxic T lymphocyte and alloantibody (alloAb) titers. To further evaluate the in vivo role of IL-10, we tested the influence of a neutralizing anti-IL-10 monoclonal antibody (mAb) in both normal and donor (skin) presensitized mouse organ allograft recipients. METHODS: Heart or liver transplants were performed from B10 (H2b) donors to C3H (H2k) recipients. Anti-IL-10 mAb (SXC.I) was administered intravenously in a single injection or repeated once daily injections. Cytotoxic activity of graft-infiltrating cells was determined by 51Cr-release assay. Circulating alloAb levels were quantified by complement-dependent cytotoxicity and flow cytometry. RESULTS: Survival of vascularized B10 cardiac allografts in normal recipients was prolonged significantly in the mAb-treated groups. A single injection of 1 mg of anti-IL-10 mAb immediately after heart transplantation gave a similar graft median survival time to repeated injections of lower dose mAb (0.5 mg/day for 6 days after transplantation) (Ig isotype control 11 days; single mAb injection 18 days; multiple injection 20 days). In presensitized recipients, anti-IL-10 mAb from days 0 to 6 significantly prolonged survival of both cardiac and orthotopic liver grafts. Graft median survival time was extended from 5 to 10 days and from 4 to 11 days, respectively. Prolongation of liver allograft survival in presensitized recipients was associated with suppression of circulating alloAb levels and with significant reductions in the incidence of B220+ cells in both grafts and recipient spleens. CONCLUSIONS: The data support an adverse role of anti-IL-10 in allograft rejection; it seems that by reducing alloAb responses, anti-IL-10 mAb may have potential for use as a therapeutic immunosuppressant, particularly in presensitized organ allograft recipients.

Animals↗
PubMed1998

Promotion of NCI-Black-Reiter male rat bladder carcinogenesis by dimethylarsinic acid an organic arsenic compound.

Dimethylarsinic acid (DMAA) is a major metabolite of inorganic arsenicals in mammals. In the present study, we investigated its promoting effects on urinary bladder carcinogenesis in NCI-Black-Reiter (NBR) rats, which lack alpha2u-globulin synthesizing ability. Male 9-14-week-old NBR rats were treated sequentially with 0.05% N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN) for 4 weeks and then given 100 ppm DMAA in their drinking water (group 1) for 32 weeks. Induction of preneoplastic lesions (papillary or nodular hyperplasia) in this DMAA-treated group was significantly increased as compared to the carcinogen alone control group (P < 0.01). The development of carcinomas was also enhanced and a significant increase in the 5-bromo-2'-deoxyuridine (BrdU) labeling index of the urinary bladder epithelial cells was observed for the DMAA treatment group. These results indicate that DMAA has promoting effects on urinary bladder carcinogenesis even in NBR rats, so its effects are not dependent on the presence of alpha2u-globulin.

Alpha-Globulins↗
PubMed1998

The murine fem1 gene family: homologs of the Caenorhabditis elegans sex-determination protein FEM-1.

The pathway controlling sex determination in the nematode Caenorhabditis elegans is a model for the genetic control of cell-fate determination. We report here the cloning and characterization of a new mouse gene family with homology to FEM-1, a signal-transducing regulator in the C. elegans sex-determination pathway. This gene family consists of two known members, designated Fem1a and Fem1b. The highest degree of homology between the two mouse proteins and the nematode protein is in a domain that encodes seven sequential ANK repeats. The Fem1a gene localizes to chromosome 17 and is highly expressed in adult heart and skeletal muscle. The Fem1b gene localizes to chromosome 9 and is highly expressed in adult testis. Both genes are expressed during embryogenesis. The existence of FEM-1 homologs in the mouse raises the possibility that evolutionary conservation of ancient FEM-1 signaling interactions may play a role in vertebrate cell-fate determination.

Amino Acid Sequence↗
PubMed1998

[Preventive and therapeutic effects of calcium lactate on osteoporosis in aged ovariectomized rats].

Twelve-month-old rats were ovariectomized (OVX), remained untreated for one month. Calcium lactate was given daily by gavage at the dose of 125, 250 and 750 mg/kg(Ca125, Ca250, Ca750) for 3 months. The results showed that compared with OVX rats, Ca250 could markedly increase the bone mineral density (BMD) at right femur. Both Ca250 and Ca750 could markedly enhance the ash weight, ratio of ash weight to dry weight of left femur and ratio of 24-hour urinary Ca/Cr. Ca125 could markedly decrease serum ALP concentration. Both Ca125 and Ca250 could decrease the ratio of 24-hour urinary Hop/Cr. All doses of calcium lactate groups could elevate serum Ca, and were no influence on the volume, wet and dry weight of the left femur and serum OC levels. In conclusion, the administration of calcium lactate to aged OVX rats prevents bone resorption, and its mechanism may be relating to the supplement of calcium properly.

Animals↗