Biomedical subjects

B Huang

Publications and source records attributed to B Huang.

At least 109 records · Page 6Linked to original sources

PubMed1998

Effect of intravesical capsaicin and vehicle on bladder integrity control and spinal cord injured rats.

PURPOSE: To determine the acute effect of intravesical capsaicin on bladder mucosal integrity in normal and spinal cord injured (SCI) rats. MATERIALS AND METHODS: Intravesical reagents were instilled in 5 groups of age and weight matched female rats: 1) control + normal saline solution (NSS), 2) control + ethanol (EtOH), 3) control + capsaicin/EtOH, 4) SCI + NSS, 5) SCI + capsaicin/EtOH. Intravesical instillations were performed 4 weeks after a standard T10 SCI. Intravesical capsaicin (1 mM.) was dissolved in 30% EtOH/NSS. The animals (n = 3 each group) were sacrificed at 30 minutes, 24 hours, 72 hours, and 7 days after intravesical instillation. Whole bladders were harvested, fixed in 10% buffered formalin, and paraffin embedded. Tissue blocks were blind coded and sectioned (5 microns thickness) for histopathological analysis. All sections were initially stained with hematoxylin and eosin (H & E). Specific staining for mucin carbohydrate moieties included periodic acid-Schiff (PAS) and alcian blue. Also, immunohistochemical staining for GP51 (a urinary glycoprotein) was performed. RESULTS: Control and SCI rats exhibited similar bladder mucosal histology by H & E and mucin specific stains. Instillation of saline demonstrated no effect on bladder histology, whereas instillation of intravesical capsaicin induced a profound acute effect of thinning of the epithelium, submucosal edema, and diminished presence of GP51. EtOH produced similar pathological findings, but to a lesser degree than capsaicin. Intravesical capsaicin demonstrated a similar effect in both control and SCI animals. The peak effect was seen after 30 minutes and continued for 24 hours. Partial recovery was noted after 72 hours and complete recovery was evident by 1 week. CONCLUSIONS: The control and SCI rats demonstrated a histologically similar mucosa and glycosaminoglycan layer. The effect of saline instillation on the mucosa was negligible. Intravesical capsaicin dissolved in 30% ethanol/NSS had a profound effect on the bladder urothelium submucosa that was more pronounced than that seen with the ethanol vehicle alone in normal animals.

Administration, Intravesical↗

PubMed1998

Integrated YAC contig map of the Prader-Willi/Angelman region on chromosome 15q11-q13 with average STS spacing of 35 kb.

Prader-Willi syndrome and Angelman syndrome are associated with parent-of-origin-specific abnormalities of chromosome 15q11-q13, most frequently a deletion of an approximately 4-Mb region. Because of genomic imprinting, paternal deficiency of this region leads to PWS and maternal deficiency to AS. Additionally, this region is frequently involved in other chromosomal rearrangements including duplications, triplications, or supernumerary marker formation. A detailed physical map of this region is important for elucidating the genes and mechanisms involved in genomic imprinting, as well as for understanding the mechanism of recurrent chromosomal rearrangments. An initial YAC contig extended from D15S18 to D15S12 and was comprised of 23 YACs and 21 STSs providing an average resolution of about one STS per 200 kb. To close two gaps in this contig, YAC screening was performed using two STSs that flank the gap between D15S18 and 254B5R and three STSs located distal to the GABRA5-149A9L gap. Additionally, we developed 11 new STSs, including seven polymorphic markers. Although several groups have developed whole-genome genetic and radiation hybrid maps, the depth of coverage for 15q11-q13 has been somewhat limited and discrepancies in marker order exist between the maps. To resolve the inconsistencies and to provide a more detailed map order of STSs in this region, we have constructed an integrated YAC STS-based physical map of chromosome 15q11-q13 containing 118 YACs and 118 STSs, including 38 STRs and 49 genes/ESTs. Using an estimate of 4 Mb for the size of this region, the map provides an average STS spacing of 35 kb. This map provides a valuable resource for identification of disease genes localized to this region as well as a framework for complete DNA sequencing.

Angelman Syndrome↗

PubMed1998

Case management and recidivism of mentally ill persons released from jail.

OBJECTIVE: The study tested the hypothesis that case management provided to mentally ill offenders both in jail and after release from jail would reduce their recidivism. METHODS: A total of 261 inmates of the Lucas County (Toledo, Ohio) jail who were diagnosed with a mental disorder were tracked for three years after their release. The relationships between recidivism and diagnostic, demographic, and case management variables were examined through event history analysis. RESULTS: Recidivism was associated with age, employment, previous arrests, and receipt of community-based case management. Receipt of jail-based case management, although not directly related to recidivism, significantly increased the probability of receiving community-based case management. Receipt of community case management was significantly associated with a lower probability of rearrest and a longer period before rearrest. CONCLUSIONS: This study found hopeful signs that expanding access to case management, both inside and outside jail, will help mentally ill people live in their communities and stay out of jail.

Adult↗

PubMed1998

Presence of growth hormone secretagogue receptor messenger ribonucleic acid in human pituitary tumors and rat GH3 cells.

A novel G11-protein-coupled receptor specific for synthetic GH-releasing peptides (GHRPs) has recently been cloned and sequenced. Two forms exist, types 1a and 1b, the latter of which is biologically inactive. Using RT-PCR, we looked for the presence in tumorous pituitary cells of messenger ribonucleic acid (mRNA) for this novel GH secretagogue receptor (GHS-R). Both subtypes of GHS-R mRNA were detected in all six human pituitary somatotropinomas removed from patients with acromegaly. In culture, four of the tumors exhibited strong responses to GHRP-2 in terms of both phosphatidylinositol (PI) hydrolysis and GH secretion, but two were resistant. There was no apparent difference in the type 1a and type 1b expression pattern, as judged by RT-PCR, between responsive and nonresponsive tumors. Similarly, the rat pituitary tumor cell line, GH3, was found to express GHS-R mRNA, although these cells also did not respond to GHRPs. RT-PCR failed to detect GHS-R mRNA in eight functionless human pituitary tumors. In contrast, prolactinomas were found to express the receptor and, in culture, significant stimulation of PRL secretion and PI hydrolysis occurred in two of three tumors tested. These results demonstrate that tumorous somatotrophs express the GHS-R gene and that the occasionally observed nonresponsiveness of somatotropinomas to GHRPs is not due to the absence of the biologically active type 1a receptor. Additionally, human pituitary prolactinomas also express GHS-R and are able to respond to GHRPs in terms of PI hydrolysis and PRL secretion. In contrast, GHS-R gene expression does not appear to be associated with human functionless pituitary tumors.

Animals↗

PubMed1998

[A new burn wound covering-fibroin membrane].

OBJECTIVE: This study was aimed at determining the physical and biological properties of fibroin membrane and evaluating its clinical effects. METHODS: 1. The physical and biological properties of fibroin membrane and partial thickness porcine skin were determined with various instruments. The determinations included water ratio, tensile strength, flexibility, water permeability, adhesive force and so on. 2. CLINICAL OBSERVATION: Two wounds with same depth in the same patient were selected. One was covered by fibroin membrane. The other one was treated with 1% SD-Ag cream. The changes in these wounds were observed and compared. RESULTS: This membrane had nearly same physical and biological properties compared with partial thickness porcine skin. It had no toxicity, irritation, and antigenicity. It possessed certain amount of water permeability and could adhere to the wound. Because of its good transparency, any change in underlying wound could be directly observed. It was helpful not only in local therapy but also in study of wound healing. CLINICAL OBSERVATIONs showed that this membrane had good protecting effect to wound. Its application could obviously relieve pain of wound and the healing time was 3-5 days ahead than that of the control wound. CONCLUSION: This membrane was an ideal wound covering and was worth being popularized.

Adolescent↗

PubMed1998

[The examination of EBV-DNase gene fragment in the paraffin embedded NPC, pre-cancerous and high risk population nasopharyngeal tissues].

OBJECTIVE: To examine if EB virus enters nasopharyngeal epithelial cells in the course of the tumorigenesis in nasopharyngeal carcinoma (NPC). METHODS: Based on the annual investigation of Si-Hui county, a cancer-prevention base of the Sun Yet-sen University of Medical Sciences and Tumour Hospital outpatient clinic, more than 450 paraffin-embedded tissues with NPC, and with pre-cancerous lesions in high risk populations were collected for the detection of EBV-DNase gene fragment by an optimized PCR method. RESULTS: In 145 of the 149(97.3%) cases with invasive NPC, and 2 of 4 cases with in situ NPC, EBV-DNase gene was detected. However, in Sihui, Canton, a high-risk county for NPC, only 2 of the 155 subjects with nasopharyngeal precancerous state was the gene positive, and none of the 47 cases examined in the out-patient department of the Tumor Hospital with precancerous lesions in the nasopharynx was positive. CONCLUSION: EBV is seldomly detected in the non-malignant and precancerous lesions in the nasopharynx in high-risk populations. It implies that EBV is probably not etiologically involved in the genesis of NPC.

Deoxyribonucleases↗

PubMed1998

Detection of filarial larvae in mosquitoes with oligonucleotide probe.

OBJECTIVE: To investigate a new way to detect filarial larvae in mosquitoes and apply it to the surveillance of filariasis. METHODS: An oligonucleotide probe that was species-specific to W. malayi was synthesized and marked with 32P using molecular biological technique. Then the probe was tested with dot hybridization in detection of W. malayi filarial larvae from mosquitoes. RESULTS: The minimal detectable limit was found to be 2 ng DNA of filarial larvae or microfilaria (Mf.), with no cross reaction with other animal filariae. A single larva can be detected when infected mosquitoes were tested one by one. One infected mosquito can be detected from a group of 20 mosquitoes tested together. CONCLUSIONS: Our probe is sensitive and specific. It is practical to apply our probe to mosquito surveillance in Brug's filariasis endemic areas.

Animals↗

PubMed1998

[Interleukin-6 gene cloning, expression and purification].

OBJECTIVE: The main purpose of this paper is to study the batch production of recombinant human interleukin-6(rhIL-6). METHODS: The cloned rhIL-6 gene is under the control of T7 promoter of pET30a vector and expressed in E. coli. RESULTS: The ratio of expressed recombinant protein to total cell protein is more than 50%. The rhIL-6 molecular weight is 21,000, isoelectric point is 6.7. The purity of the rhIL-6 is more than 95%, and the activity of rhIL-6, determined by IL-6 dependent mice hybridoma cell line 7TD1 and MTT assay, is 0.35 ng/ml. CONCLUSIONS: All results mentioned show that rhIL-6 meets the request of the middle scale production.

Cloning, Molecular↗

PubMed1998

[RP-HPLC method for determination of isorhynchophylline in plasma and its pharmacokinetics in rabbits].

A reversed phase HPLC method for determination of isorhnchophylline (IRHY) in rabbit plasma was developed. A Shimadzu LC-10A liquid chromatograph equipped with a Shimadzu SPD-10A multiwavelength detector and a Chromatopac LC-10A data processor were used. The analytical column was a 4.6 mm x 150 mm CLC-ODS. The mobile phase was a mixture of methanol-water (95:5), the flow rate was 1 ml.min-1. Detection was performed at UV 254 nm. The calibration curve was linear in the range from 0.016 to 16 micrograms.ml-1 with gamma = 0.9990. The lowest detection limit was 0.016 microgram.ml-1. The precision and accuracy of within-day and day-to-day ranged from 3.8% to 6.9%. The recoveries were 80.5% to 85.1%. The drug concentrtion-time curves of IRHY in rabbits after i.v. of 2 mg.kg-1 and 5 mg.kg-1 were shown to fit a two-compartment open model with half-times of 1.32 +/- 0.6 h and 1.25 +/- 0.09 h respectively. The absorption was fast after intraduodenal administration of IRHY (2 mg.kg-1 and 5 mg.kg-1) to rabbits with half-times of 1.75 +/- 0.18 h and 1.26 +/- 0.20 h, respectively. The bioavailability of IRHY was about 42.4% to 69.4%. The results showed that the method was simple and fast. The absorption and elimination were fast atfer intraduodenal administration or i.v. of IRHY to rabbits.

Alkaloids↗

PubMed1998

[Correction of spectral interferences by ICP-AES primary expert system].

A subpackage for spectral interference correction has been set up in ICP-AES primary expert system. Some numerical recipes have been applied in this subpackage, such as curve smoothing, derivative spectrum, FFT technique, spectral resolving etc. A comprehensive method for spectral interference correction is presented. All these numeric recipes have been tested with simulated data and also utilized in several typical examples of real spectra. Results are satisfactory.

English Abstract↗

PubMed1998

[Study of spectral interferences of REEs with the matrix of dy for a high resolution ICP-AES].

The spectral interferences of the matrix of Dy on other REEs have been studied for a high resolution ICP-AES with a grating of 3600 grooves/mm. 66 analytical lines of 14 REEs have been selected as the prominent lines in the spectral interference studies. Three kinds of databases for Dy lines have been established for the spectra search and recognition. Thus, these databases can provide information of Dy lines accurately and conveniently.

English Abstract↗

PubMed1998

[Study of the excitation and diffusion processes of sample atoms in a microwave boosted microsecond-pulse glow discharge source with optical emission spectrometry].

The excitation and diffusion processes of brass sample atoms in a GD-MIP tandem source have been studied with a home-made MIP boosted micros-pulse GD device. Experimental results show that under relatively low discharge pressure (< 180Pa), the micros-pulse GD can couple quite well with MIP and emit strong radiation of analytical lines. When the GD source is operated under a pressure higher than 200Pa, two emission peaks appear independently in time for a given resonant atomic line, because sample atoms are structurally excited separately first by the micros-pulse GD and then by the MIP. According to the two emission peaks, the diffusing velocities of copper atoms and zinc atoms can be calculated, yielding values of 150 and 129m/s, respectively, and the most excited area in-the micros-pulse GD is about 1.94-2.25mm away from the sputtering surface of the sample cathode. The effects of discharge parameters on emission intensities have been also investigated.

English Abstract↗

PubMed1997

Synthetic strategies for the preparation of precursor polymers and of microcapsules suitable for cellular entrapment by polyelectrolyte complexation of those polymers.

The production of microcapsules suitable for the entrapment of mammalian cell by means of polyelectrolyte complexation has, of a necessity, led to the development of novel strategies for the preparation of relatively bioinert polymers which complex efficiently under unique conditions to produce a mechanically resilient membrane with efficient transport properties. In this communication we relate a brief overview of capsule-membrane forming systems for the immunoisolation (or potential immunoisolation) of mammalian cells, which are based upon the complexation of polyelectrolyte (PE) polymers; with emphasis on precursor synthesis and relationships between precursor polymer structure and capsule membrane stability.

Animals↗

PubMed1997

Cloning and characterization of a gene encoding an actin-related protein in Chlamydomonas.

The genomic sequence of an actin-related gene in Chlamydomonas reinhardtii has been determined. The deduced amino acid sequence of this gene shares a 63.9% identity with that of a recently reported conventional actin-encoding gene in C. reinhardtii. Phylogenetic analysis shows that the product of this actin-related gene does not fit into conventional actin or any major actin-related protein categories. The actin-related gene in C. reinhardtii contains seven introns in the coding region and, as described for the conventional actin gene, it contains several sequences similar to the 'tub box' sequence motif in its 5'-upstream region. Southern blot analysis of the gene shows a hybridization pattern different from that of the conventional actin gene, indicating that these genes are distinct from one another. Northern blot analysis of poly(A)+RNA shows the messages of the two genes to be very similar in size, yet the message level of the actin-related gene is significantly lower than that of the conventional actin gene.

Actins↗

PubMed1997

Analysis of the contact sites on the CD4 molecule with class II MHC molecule: co-ligand versus co-receptor function.

The CD4 molecule interacts with the alpha2 and beta2 domains of the MHC class II molecules. However, the class II contact sites on CD4 are less clear. Involvement of different regions throughout D1, D2, and D3 domains have been suggested. To further delineate the class II MHC contact sites on CD4, a crystal structure-informed mutagenesis was performed. Alanine scan mutants were generated for exposed residues located throughout D1 and the FG loop of D2, and in the "hinge-like" region, a short and flexible region between D2 and D3. Mutants were tested in a co-ligand (Dd stimulation) and a co-receptor (staphylococcal enterotoxin B stimulation) assay. In the co-ligand assay, TCR and CD4 interact with two distinct ligands (Dd or HLA-DR), while in the co-receptor assay both molecules interact with the same ligand, namely HLA-DR. Results show that residues from both lateral faces of D1 and the FG loop of D2 are implicated in interaction with class II, although a bigger surface of CD4 was involved in co-receptor compared with co-ligand function. The potential involvement of residues on both the top and two side faces of CD4 is consistent with a bivalent model, which involves the interaction between a single CD4 and two class II molecules. Alternatively, our results can be interpreted with a model of a specifically organized CD4 and/or class II oligomerization event. Finally, results from the hinge region mutants revealed a very important role in maintaining the overall structural integrity of CD4, its topology, and function.

CD4 Antigens↗

PubMed1997

Molecular sequences of two minisatellites in blacklip abalone, Haliotis rubra.

In the cloning and sequencing of growth-promoting genes of the blacklip abalone, Haliotis rubra (Leach, 1814), two DNA variable number of tandem repeats (VNTRs) were identified in abalone cDNA libraries. One contained a 33 bp repeat unit (5'-CCCAAGGTCCCCAAGGTCAGGGAGGCGAAGGCT-3') located in the 3' untranslated region of a putative growth hormone (GH) gene, and the repeat was designated as GHR. The other contained an 18 bp repeat unit (5'-ACCCGGCGCTTATTAGAG-3') located in the 3' untranslated region of a putative molluscan insulin-related peptides (MIP) gene, and was designated as MIPR. Primers flanking the two VNTR repeat regions were derived from sequence information. One hundred blacklip abalones were collected along the Victorian coastline and used in a preliminary population study. The range of GHR alleles containing the 33 bp basic unit repeat motif included 7 to 20 repeats, with allele GHR 8 not being identified. The most frequent alleles contained GHR 16 and 17 repeats (56.0% and 16.5%, respectively). Four types of alleles were identified in MIPR, viz 4, 5, 6 and 7 repeats. The alleles containing 6 and 5 repeats were the most frequent (50.0% and 41.5%, respectively). Overall, the results indicate that these two DNA minisatellites have use in abalone studies, including paternity resting, triploid testing, population genetic structure, and gene flow.

Alleles↗

PubMed1997

Effects of the medium conditioned by endothelial cells under hypoxic condition on the phenotype of porcine pulmonary arterial smooth muscle cells.

The effects of the medium conditioned by endothelial cells under hypoxic condition on the phenotype modulation of pulmonary artery smooth muscle cells (PASMCs) were investigated by using cell culture and morphometrical analysis. The results showed that the number of diploid cells and alpha-sm-actin of PASMCs in the hypoxic endothelial cell conditioned medium group (HECCM) was lower and the myofibrilles were even less than that in normal endothelial cell conditioned medium group (NECCM). On the contrary, the volume density of rough endoplasmic reticulum (RER) and mitochondria of PASMCs in the HECCM group was higher than that in the NECCM group, i.e. altering from a contractile type to a synthetic type. However, under direct hypoxic condition for 24 h, the phenotype of cultured PASMCs remained unchanged, i.e. retained contractile type. It suggests that the HECCM can induce phenotype modulation of PASMCs, may be mediated by the pulmonary artery endothelial cells (PAECs) which can secrete some cytokins affecting the PASMCs.

Animals↗

PubMed1997

Refined molecular characterization of the breakpoints in small inv dup(15) chromosomes.

Inv dup(15) is the most common supernumerary marker chromosome in humans. To investigate the mechanism responsible for this frequent chromosome rearrangement, we characterized the breakpoints in 18 individuals with small inv dup(15) chromosomes [i.e., negative for the Prader-Willi (PWS)/Angelman syndrome (AS) critical region]. Since two proximal breakpoint regions ("hotspots") for PWS/AS deletions have been previously identified with the most proximal 15q markers D15S541/S542 and S543, we hypothesized that formation of the small inv dup(15) chromosomes may involve one or both of these breakpoint hotspots. By analysis with S542, both breakpoint regions were found to be involved in approximately equal frequencies. In ten cases, the inv dup(15) was negative for S542 (Class I), indicating the breakpoint is between the centromere and the most proximal marker on chromosome 15. For the other eight cases, S542 was positive by fluorescence in situ hybridization (5/5) and/or microsatellite analysis (7/7), but S543 was negative (Class II). These two breakpoint regions appear to be the same as the two proximal breakpoints reported in the common PWS/AS deletions. To initiate cloning and sequencing of the Class II breakpoint, the gap in the yeast artificial chromosome (YAC) contig between S541/S542 and S543 was filled by screening the CEPH YAC and mega-YAC libraries. YACs 705C2 and 368H3 were found to bridge this gap, and therefore contain the more distal breakpoint region. The finding of consistent breakpoints in small inv dup(15), like that found in PWS/AS deletions, provides strong evidence for hotspots for chromosome breakage in this region. In addition, our results show that two extra copies (tetrasomy) of the region from 15cen to the euchromatic region containing S542 are present in individuals with Class II breakpoints. Since most individuals carrying a small inv dup(15) are phenotypically normal, the euchromatin region included in the small inv dup(15) chromosomes does not appear to contain genes with clinically significant dosage effects.

Adolescent↗