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L Fang

Publications and source records attributed to L Fang.

At least 19 recordsLinked to original sources
PubMed2006

Unliganded and hormone-bound glucocorticoid receptors interact with distinct hydrophobic sites in the Hsp90 C-terminal domain.

Unlike most chaperones, heat-shock protein 90 (Hsp90) interacts with a select group of "client proteins" that regulate essential biological processes. Little is known about how Hsp90 recognizes and binds these proteins. The glucocorticoid receptor (GR) is a well characterized Hsp90 client protein, whose hormone binding, nuclear-cytoplasmic trafficking, and transcriptional activity are regulated by Hsp90. Here, we provide evidence that unliganded and hormone-bound GR interact with two distinct, solvent-exposed hydrophobic sites in the Hsp90 C-terminal domain that contain the sequences "MxxIM" (HM10) and "L/MxxIL" (HM9). Our results indicate that binding of Hsp90 HM10 to unliganded GR stabilizes the unliganded ligand-binding pocket of GR indirectly by promoting an intramolecular interaction between the C-terminal alpha-helix (H12) and a solvent-exposed hydrophobic groove in the GR ligand binding domain. In the presence of hormone, Hsp90 appears to bind the hydrophobic groove of GR directly by mimicking the interactions of GR with transcriptional coactivators. The identified interactions provide insights into the mechanisms that enable Hsp90 to regulate the activity of both unliganded and hormone-bound GR and to sharpen the cellular response to hormone.

Amino Acid Sequence↗
PubMed2006

Mutations in BMPR-IB and BMP-15 genes are associated with litter size in Small Tailed Han sheep (Ovis aries).

The Small Tailed Han is a prolific local sheep breed in China. The bone morphogenetic protein receptor IB (BMPR-IB) gene, which affects the fecundity of Booroola Merino sheep, and the bone morphogenetic protein 15 (BMP-15) gene, which affects the fecundity of Inverdale, Hanna, Belclare, Cambridge, and Lacaune sheep, were studied as candidate genes associated with the prolificacy of Small Tailed Han sheep. Single nucleotide polymorphisms of BMPR-IB and BMP-15 genes were detected in Small Tailed Han ewes (n = 188) by PCR-RFLP. The combined effect of the 2 genes on the prolificacy of Small Tailed Han sheep was studied. The results indicated that the same FecB mutation (Q249R) occurred in the BMPR-IB gene in Small Tailed Han ewes as found in Booroola Merino ewes. The Small Tailed Han ewes with genotypes FecB(B)/FecB(B) and FecB(B)/FecB(+) had 1.40 (P < 0.01) and 1.11 (P < 0.01) more lambs, respectively, than those with genotype FecB(+)/FecB(+). The same FecX(G) mutation (Q239Ter) of the BMP-15 gene was found in Small Tailed Han ewes as in Belclare and Cambridge ewes. The Small Tailed Han ewes with the heterozygous mutant FecX(G)/FecX(+) had 0.55 (P < 0.01) more lambs than those with the wild-type FecX(+)/FecX(+). The Small Tailed Han ewes carrying mutations in both BMPR-IB and BMP-15 genes had greater litter size than those with either mutation alone. In view of our results, marker-assisted selection using both BMPR-IB and BMP-15 genes is warranted to increase litter size in sheep and will be of considerable economic value to sheep producers.

Alleles↗
PubMed2006

Association between expression of reproductive seasonality and alleles of melatonin receptor 1A in goats.

To determine whether a link exists between reproductive seasonality and the structure of the melatonin receptor 1A (MTNR1A) gene, the latter was studied in year-round estrous breeds (Jining Grey and Boer goats) and seasonal estrous breeds (Liaoning Cashmere, Inner Mongolia Cashmere, Wendeng milk and Beijing native goats). A large fragment of exon 2 of MTNR1A gene was amplified by PCR using sheep sense and antisense primers in 260 does of six breeds. The uniform 824 bp PCR product was digested with restriction endonucleases MnII and RsaI, and checked for the presence of restriction sites. No polymorphism at the MnII cleavage sites was detected in all six goat breeds and no relationship could be established between the MnII cleavage sites of MTNR1A gene and reproductive seasonality in goats. For polymorphic RsaI cleavage site at base position 53, only genotype RR (267 bp/267 bp) was detected in Jining Grey goats, both genotype RR and genotype Rr (267 bp/320 bp) were found in all other goat breeds, no genotype rr (320 bp/320 bp) was detected in all six goat breeds. Frequency of genotype RR was obviously higher, and frequency of genotype Rr was obviously lower in year-round estrous goat breeds than in seasonal estrous goat breeds. Sequencing revealed one mutation (G52A) in genotype Rr compared with genotype RR. For polymorphic RsaI cleavage site, the differences of genotype distributions were significant (P<0.05) between year-round estrous goat breeds and seasonal estrous goat breeds. These results preliminarily showed an association between genotype RR and year-round estrus in goats, and an association between genotype Rr and seasonal estrus in goats.

Alleles↗
PubMed2006

The human papillomavirus type 11 E1/\E4 protein is not essential for viral genome amplification.

An abundant human papillomavirus (HPV) protein E1/\E4 is expressed late in the virus life cycle in the terminally differentiated layers of epithelia. The expression of E1/\E4 usually coincides with the onset of viral DNA amplification. However, the function of E1/\E4 in viral life cycle is not completely understood. To examine the role of E1/\E4 in the virus life cycle, we introduced a single nucleotide change in the HPV-11 genome to result in a truncation of E1/\E4 protein without affecting the E2 amino acid sequence. This mutated HPV-11 genome was introduced into a human foreskin keratinocyte cell line immortalized by the catalytic subunit of human telomerase, deficient in p16(INK4a) expression, and previously shown to support the HPV-11 life cycle when grown in organotypic raft culture. We have demonstrated that E1/\E4 is dispensable for HPV-11 viral DNA amplification in the late stages of the viral life cycle.

Cell Line↗
PubMed2006

Induction of productive human papillomavirus type 11 life cycle in epithelial cells grown in organotypic raft cultures.

The study of the human papillomavirus (HPV) life cycle was hampered for more than 50 years by the lack of a conventional cell culture system for propagating HPV. Considerable progress has been made in the production of several HPV types using either organotypic rafts or human epithelial xenografts in immunocompromised mice. In this study, we demonstrated episomal maintenance of HPV-11 DNA in N-Tert cells. HPV-11 episomal DNA containing cell populations grown in raft culture showed induction of the productive viral life cycle. HPV-11 DNA amplification and viral capsid antigen synthesis were detected in differentiated layers of epithelia. The viruses generated were able to infect keratinocytes in vitro, which indicate that viruses generated were infectious. The demonstration of the productive HPV-11 life cycle in raft culture from cloned HPV-11 DNA will facilitate genetic analyses of viral gene functions that was not possible using the human xenograft athymic mouse model.

Animals↗
PubMed2006

A slide latex agglutination test for the rapid detection of antibodies in serum against porcine parvovirus.

A slide latex agglutination test (LAT) was developed and evaluated to detect serum antibodies against porcine parvovirus. Porcine parvovirus antigen was obtained by 10% PEG-6000 and 0.5 mol/l sodium chloride precipitation, and inactivated by 0.1% methanal. Two per cent suspensions of latex particles (0.5-0.8 microm) were coated by adding an equal volume of porcine parvovirus antigen at 0.34 microg/ml. Repeatability of latex agglutination test was evaluated with a panel of 100 sera using the same and different antigen lots. A good agreement between LAT and haemagglutination inhibit assay was observed. Because of convenience and speed of performance, this method would be used widely in clinic examination.

Animals↗
PubMed2006

Obesity among individuals with serious mental illness.

OBJECTIVE: To study the distribution and correlates of body mass index (BMI) among individuals with serious mental illness. METHOD: A total of 169 participants were recruited from randomly selected out-patients receiving community-based psychiatric care and were interviewed with items from the National Health and Nutrition Examination Survey (NHANES) III. Their BMI was compared with that of 2404 matched individuals from the NHANES data set. RESULTS: The distribution of BMI in the psychiatric sample significantly differed from that of the comparison group; 50% of women and 41% of men were obese compared with 27% and 20% in the comparison group. Within the psychiatric sample, higher BMI was associated with current hypertension and diabetes, a wish to weigh less, and reduced health-related functioning. CONCLUSION: Obesity is more prevalent among individuals with serious mental illness than in demographically matched individuals from the US general population. Among persons with mental illness, obesity is associated with co-occurring health problems.

Adolescent↗
PubMed2004

Involvement of peripheral neuropeptide Y receptors in sympathetic modulation of acute cutaneous flare induced by intradermal capsaicin.

In a recent study, we have demonstrated that the dorsal root reflex (DRR)-mediated acute cutaneous neurogenic inflammation following intradermal injection of capsaicin (CAP) is sympathetically dependent and subject to modulation by peripheral alpha(1)-adrenoceptors. Postganglionic sympathetic neurons contain not only adrenergic neurotransmitters, but also non-adrenergic substances, including neuropeptide Y (NPY). In this study, we examined if peripheral NPY receptors participate in the flare following CAP injection. Different NPY receptor subtypes were studied by using relatively specific agonists and antagonists for the Y(1) and Y(2) subtypes. Changes in cutaneous blood flow on the plantar surface of the foot were measured using a laser Doppler flowmeter. Following CAP injection, cutaneous flare spread more than 20 mm away from the site of CAP injection. Removal of the postganglionic sympathetic nerves by surgical sympathectomy reduced dramatically the CAP-evoked flare. If the foot of sympathectomized rats was pretreated with either NPY or Y(2) receptor agonists by intra-arterial injection, the spread of flare induced by CAP injection could be restored and prolonged. However, if the spinal cord was pretreated with a GABA(A) receptor antagonist, bicuculline, to prevent DRRs, NPY or an Y(2) receptor agonist no longer restored the CAP-evoked flare. A Y(1) receptor agonist did not affect the CAP-evoked flare in sympathectomized rats. In sympathetically intact rats, blockade of either peripheral NPY or Y(2) receptors with [D-Trp(32)]-NPY or BIIE0246 markedly reduced the flare induced by CAP injection, whereas blockade of peripheral Y(1) receptors by BIBP3226 did not obviously affect the flare. It is suggested that NPY is co-released with NE from the postganglionic sympathetic terminals to activate NPY Y(2) and alpha(1) receptors following CAP injection. Both substances are involved, at least in part, in modulation of the responses of CAP sensitive afferents thereby affecting their ability to evoke the release of inflammatory agents from primary afferents.

Animals↗
PubMed2004

Association between PCR-SSCP of growth differentiation factor 9 gene and high prolificacy in Small Tail Han sheep.

Small Tail Han sheep that has significant characteristics of high prolificacy and nonseasonal ovulatory activity is an excellent local sheep breed in P.R. China. The lambing percentage averaged 260% in Small Tail Han sheep. Growth differentiation factor 9 (GDF9) gene, which was essential for growth and differentiation of early ovarian follicles, was considered as a possible candidate gene for litter size in Small Tail Han sheep. The genetic polymorphism of a part of the GDF9 gene was detected in 130 ewes of Small Tail Han sheep by PCR-SSCP. The results indicated that there were two genotypes (AA and AB) detected by two primer pairs. In both exon 1 and exon 2 of the GDF9 gene in Small Tail Han sheep, frequencies of AA genotype were 0.846 and 0.908, frequencies of AB genotype were 0.154 and 0.092, frequencies of A allele were 0.923 and 0.954, and frequencies of B allele were 0.077 and 0.046, respectively. The results of chi2 fitness test indicated that both exon 1 and exon 2 of the GDF9 gene were in Hardy-Weinberg equilibrium (p > 0.05) in Small Tail Han sheep. Least squares means of litter size in the first and the second parity for genotype AA were 0.30 (p <0.05) and 0.77 (p <0.0001) more than those for genotype AB detected in exon 1 of the GDF9 gene in Small Tail Han sheep, respectively. Fragments detected in exon 2 of the GDF9 gene had no significant effect (p > 0.05) on litter size in both the first and the second parity in Small Tail Han sheep. Litter size in sheep is lowly heritable, expressed only in females, and manifested relatively late in life. Access to genetic markers would thus be advantageous in selection programs.

Alleles↗
PubMed2004

Impact of indoor air temperature and humidity in an office on perceived air quality, SBS symptoms and performance.

UNLABELLED: Perceived air quality (PAQ), sick building syndrome (SBS) symptoms and performance of office work were studied in a real office space at three levels of air temperature and humidity and two levels of ventilation rate (20 degrees C/40%, 23 degrees C/50%, 26 degrees C/60% RH at 10 l s(-1) p(-1) outside air, and 20 degrees C/40% RH at 3.5 l s(-1) p(-1) outside air). Thirty female subjects participated in the experiment. They were exposed to each environmental condition for 280 min. Thermal comfort was maintained at different thermal environments by self-adjustment of clothing. The subjects performed simulated office work throughout each exposure and repeatedly marked a set of visual-analog scales to indicate their perception of environmental conditions and of the intensity of SBS symptoms at the time. The study confirmed the previously observed impact of temperature and humidity on perceived air quality and the linear correlation between acceptability and enthalpy. The impact on perceived air quality of decreasing the ventilation rate from 10 to 3.5 l s(-1) per person could be counteracted by a decrement of temperature and humidity from 23 degrees C/50% RH to 20 degrees C/40% RH. Performance of office work was not significantly affected by indoor air temperature and humidity. However, several SBS symptoms were alleviated when the subjects worked at low levels of air temperature and humidity, which implies that a longer term exposure to low indoor air temperature and humidity might help to improve the performance of office work. PRACTICAL IMPLICATIONS: The findings of this study indicate the importance of indoor air temperature and humidity on perceived air quality and SBS symptoms. In practice, the required ventilation rate for comfort and health should no longer be independent of indoor air temperature and humidity.

Adult↗
PubMed2003

Suppression of human papillomavirus gene expression in vitro and in vivo by herpes simplex virus type 2 infection.

Recent epidemiological studies have found that women infected with both herpes simplex virus type 2 (HSV-2) and human papillomavirus (HPV) type 16 or HPV-18 are at greater risk of developing cervical carcinoma compared to women infected with only one virus. However, it remains unclear if HSV-2 is a cofactor for cervical cancer or if HPV and HSV-2 interact in any way. We have studied the effect of HSV-2 infection on HPV-11 gene expression in an in vitro double-infection assay. HPV transcripts were down-regulated in response to HSV-2 infection. Two HSV-2 vhs mutants failed to reduce HPV-16 E1;E4 transcripts. We also studied the effect of HSV-2 infection on preexisting experimental papillomas in a vaginal epithelial xenograft model. Doubly infected grafts demonstrated papillomatous transformation and the classical cytopathic effect from HSV-2 infection. HPV and HSV DNA signals were mutually exclusive. These studies may have therapeutic applications for HPV infections and related neoplasms.

Animals↗
PubMed2003

Pharmacokinetics of a new sustained-release formulation of theophylline sodium glycerinate in healthy subjects with a new asymmetric dosage regimen.

Pharmacokinetics of a new sustained-release formulation of theophylline sodium glycerinate in healthy subjects was studied. In this study, a new asymmetric dosage regimen was presented to achieve a better accordance with the chronotherapy of asthma. Each of 10 subjects was administered one tablet (equivalent to 0.1 g anhydrous theophylline) in the morning and four tablets in the evening for a consecutive 6 days and blood samples were collected at the predetermined time and analyzed by a validated HPLC method. This new regimen produced a steady and effective level of theophylline in plasma for the whole day, especially in the evening. A lower dose in the morning could reach the effective level (C(min)4.97 +/- 1.60 microg/mL and C(max)10.68 +/- 1.80 micro g/mL over the a.m. dosing interval) and a higher dose in the evening did not result in toxic levels but led to a reasonable concentration range (C(max)9.72 +/- 1.56 microg/mL over p.m. dosing interval), which could maintain a higher plasma theophylline concentration without the risk of serious adverse events and control asthmatic symptoms probably occurring during the night or early in the morning. The results suggested that the proposed asymmetric regimen was necessary, practicable and safe for twice daily sustained-release tablets of theophylline sodium glycerinate and also provides the basis for the clinical dosage regimen of other theophylline formulated products.

Adult↗
PubMed2003

Increased phosphorylation of the GluR1 subunit of spinal cord alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate receptor in rats following intradermal injection of capsaicin.

Ionotropic glutamate receptors are ligand-gated ion channels that help mediate rapid excitatory neurotransmission in the CNS. alpha-Amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) receptors are critical for synaptic plasticity in central nociceptive transmission. The current study was designed to investigate the role of the AMPA receptor subunit, GluR1, and its phosphorylated forms (at Ser-831 and Ser-845) in central sensitization in rat spinal cord. Western blots and immunohistochemistry were performed to examine the expression and localization of GluR1 and the phosphorylated forms of GluR1 (phospho-GluR1) at Ser-831 and Ser-845 with specific antibodies. Results showed that immunolabeling of GluR1 protein in rat spinal cord can be detected at 110 kD, and two phospho-GluR1 proteins were found at 106 kD. A significant upregulation of phospho-GluR1 both at Ser-831 and Ser-845 was found by 5 min after capsaicin treatment, and this increase lasted at least 60 min. Immunostaining showed that GluR1 and its phosphorylated forms were localized in the superficial laminae of dorsal horn and quantitative image analysis supported the immunoblotting results. Our findings are consistent with the suggestions that AMPA receptors show increased responsiveness because of their phosphorylation and that this may contribute to central sensitization following intradermal injection of capsaicin.

Animals↗
PubMed2002

Dose range study of pharmacokinetics, safety, and preliminary antiviral activity of emtricitabine in adults with hepatitis B virus infection.

A multicenter, open-label study was performed to evaluate the safety, anti-hepatitis B virus (anti-HBV) activity, and pharmacokinetics of emtricitabine therapy administered once daily for 8 weeks to patients infected with HBV. Clinical and virologic evaluations were completed at the baseline; at 7, 14, 28, 42, and 56 days during treatment; and at 24, 48, and 28 days posttreatment. Forty-nine patients were enrolled in five dose cohorts (doses of 25, 50, 100, 200, and 300 mg, all of which were administered once daily [q.d.]). Peak plasma emtricitabine concentrations occurred within 1.5 h following dosing. Plasma emtricitabine concentrations (maximum concentrations of drug in plasma and areas under the concentration-time curves) increased nearly dose proportionally over the 25- to 300-mg dose range, with relatively small intersubject variabilities. The plasma half-life of emtricitabine ranged from 6 to 9 h. HBV DNA levels were measured by the Digene HBV Hybrid Capture II assay. Viral suppression (reduction in log(10) serum HBV DNA levels) occurred in all dose cohorts. All doses demonstrated potent and rapid antiviral activities, with a trend toward a greater suppression with daily doses of 100 mg or greater. At 2 months, the median change in the serum HBV DNA level from the baseline level ranged from -1.7 log(10) for the 25-mg dose administered q.d. to -3.3 log(10) for the 300 mg dose administered q.d. Emtricitabine was well tolerated over the 2-month dosing period. These results support further clinical development of emtricitabine for the treatment of chronic hepatitis B infection.

Adolescent↗
PubMed2001

Signal amplification by rolling circle amplification on DNA microarrays.

While microarrays hold considerable promise in large-scale biology on account of their massively parallel analytical nature, there is a need for compatible signal amplification procedures to increase sensitivity without loss of multiplexing. Rolling circle amplification (RCA) is a molecular amplification method with the unique property of product localization. This report describes the application of RCA signal amplification for multiplexed, direct detection and quantitation of nucleic acid targets on planar glass and gel-coated microarrays. As few as 150 molecules bound to the surface of microarrays can be detected using RCA. Because of the linear kinetics of RCA, nucleic acid target molecules may be measured with a dynamic range of four orders of magnitude. Consequently, RCA is a promising technology for the direct measurement of nucleic acids on microarrays without the need for a potentially biasing preamplification step.

Alleles↗
PubMed2001

Genotype analysis of the NF1 gene in the French Canadians from the Québec population.

We genotyped 19 NF1 families from the French Canadians of the Québec population with six intragenic polymorphic markers including 2 RFLPs (EcoRI and RsaI) and 4 microsatellites (IVS26-2.3, IVS27AC28.4, IVS27AC33.1, and IVS38GT53.0). Genotype analysis indicated families 7610 and 7473 bear deletions. In Family 7610 the deletion removed the entire NF1 gene except exons 1 to 4b. The breakpoint of the deletion is located between exons 4a and 4b. The deletion 7473 was derived from the maternal chromosome and exons 1 to 5 were deleted. The breakpoint of the deletion is located between exons 7 and 13. Their phenotypes are reported. The allele frequencies of microsatellites IVS27AC28.4 and IVS38GT53.0 are compared to previously reported data from Caucasians, including Spanish and Italians. The difference is statistically significant (P < 0.0036) for marker IVS27AC28.4 between the Québec French Canadian and the Italian population.

Alleles↗
PubMed2001

p202, an interferon-inducible negative regulator of cell growth, is a target of the adenovirus E1A protein.

Studies have revealed that human adenovirus-encoded E1A protein promotes cell proliferation through the targeted interaction with cellular proteins that act as key negative regulators of cell growth. The targets of E1A protein include the retinoblastoma tumor suppressor protein (pRb). Because p202, an interferon (IFN)-inducible murine protein (52-kDa), negatively regulates cell growth in part through the pRb/E2F pathway, we tested whether the p202 is a target of the adenovirus-encoded E1A protein for functional inactivation. Here we report that the expression of E1A protein overcame p202-mediated inhibition of cell growth and this correlated with an alleviation of p202-mediated inhibition of the transcriptional activity of E2F. Furthermore, E1A protein relieved p202-mediated inhibition of the specific DNA-binding activity of E2F complexes, including those containing the pocket proteins. Additionally, the E1A protein bound to p202 both in vitro and in vivo and a deletion of four amino acids in the conserved region 2 (CR2) of E1A protein significantly reduced the binding of E1A to p202. Interestingly, ectopic expression of p202 under reduced serum conditions significantly reduced E1A-mediated apoptosis. Taken together, our observations provide support to the idea that the p202 and adenovirus E1A protein functionally counteract each other and E1A protein targets p202 to promote cell proliferation.

Adenovirus E1A Proteins↗