Biomedical subjects

H Wang

Publications and source records attributed to H Wang.

At least 253 records · Page 14Linked to original sources

PubMed2002

Expression of estrogen receptors (alpha, beta) and insulin-like growth factor-I in breast tissue from surgically postmenopausal cynomolgus macaques after long-term treatment with HRT and tamoxifen.

The novel estrogen receptor ERbeta could be a key factor for proliferation and breast cancer risk. In a primate model for long-term HRT, surgically postmenopausal cynomolgus macaques were treated for 35 months with conjugated equine estrogens (CEE), medroxyprogesterone acetate (MPA), CEE+MPA and tamoxifen (n=5 in all groups). The immunohistochemical expression of ERalpha, ERbeta and IGF-I in breast tissue was quantified by image analysis. Overall the levels of ERbeta were higher than for ERalpha. In untreated animals, the median area of positive cells was 58% and 21%. The lowest levels for ERbeta were seen during treatment with CEE/MPA (3%) and in this group the expression of ERbeta was lower than for ERalpha. Tamoxifen had effects similar to estrogen. ERbeta may have a role to modulate the proliferative response following activation of ERalpha. The results suggest that hormonal treatments have a different influence on the balance ERbeta/ERalpha in breast tissue.

Journal Article↗

PubMed2002

The increase in levels of interferon-inducible proteins p202a and p202b and RNA-dependent protein kinase (PKR) during myoblast differentiation is due to transactivation by MyoD: their tissue distribution in uninfected mice does not depend on interferons.

The murine 200 family proteins p202a, p202b, and p204, and also RNA-dependent protein kinase (PKR) are inducible by interferons (IFNs). p202a, p202b, and p204 modulate the activity of a large variety of transcription factors and also are involved in muscle differentiation. PKR is a multifunctional serine/threonine kinase, which is involved in antiviral defense and cell growth control and in the response to various stress signals. We reported earlier that the level of p204 increases during cultured C2C12 myoblast differentiation to myotubes in consequence of transactivation by the skeletal muscle-specific MyoD protein. The levels of p202a, p202b, and PKR also increase during the differentiation. We report here that these increased protein levels also are due to the transactivation of their genes by MyoD. This is made possible by the occurrence in each of these genes of at least six E boxes, which are recognition sites for MyoD. We also show that the distribution of the p204, p202a, p202b, and PKR proteins in five tissues of adult C129 mice is the same in wild-type mice and mice lacking the IFN-alpha, IFN-beta, and IFN-gamma receptors. This indicates that the synthesis and distribution of these proteins in uninfected adult mice are not affected by endogenous IFNs.

Animals↗

PubMed2002

Decreased interleukin-10 in tracheal aspirates from preterm infants developing chronic lung disease.

UNLABELLED: The inability to balance pulmonary injury with healing may predispose preterm infants to chronic lung disease (CLD). It is postulated that the production of interleukin (IL)-10, an anti-inflammatory cytokine, is gestationally influenced and that CLD-prone infants may have a reduced ability to produce IL-10. METHODS: Tracheal fluid (TF) was collected at least twice weekly from 48 mechanically ventilated infants within the first 7 d of life while intubated. RESULTS: A total of 87 TF specimens were obtained. None of the 11 CLD infants (24-31 wk of gestation) had TF IL-10 levels above 4 pg/ml (0/20 TF specimens), while 14 (70%) of the 20 non-CLD preterm infants (27-36 wk of gestation) had IL-10 levels above 5 pg/ml in one or more of their TF specimens (18/48 TF specimens, p < 0.001). Only the 5 term infants who were ventilated for severe lung disease had raised IL-10 levels (17 infants, 5/19 TF specimens). IL-10 levels, if detected, (range 6-938 pg/ml) tended to be higher with increasing gestation (Spearman's rho coefficient = 0.43; p = 0.003). TF IL-10 detection was not associated with hyaline membrane disease, antenatal steroids or influenced by TF sample volume. Overall IL-8 levels were wide ranging but towards the end of week 1 the levels were significantly higher in CLD infants (CLD: median 34 184 ng/ml, preterm non-CLD: median 699 ng/ml, p < 0.001, term: 2961 ng/ml, p = 0.028). CONCLUSION: A gestationally influenced low IL-10 may predispose preterm infants to persistent pulmonary inflammation of CLD.

Body Fluids↗

PubMed2002

Logistics of referral, diagnostic assessment and treatment of patients with breast symptoms and signs.

BACKGROUND AND AIMS: The logistics of diagnosis and treatment in a hospital with slightly above 400 new cases of breast cancer per year is analysed. MATERIALS AND METHODS: The patient flow from referral, through the diagnostic procedures and through surgical treatment is described. RESULTS AND CONCLUSIONS: The basic principle of the diagnostic assessment is the triple diagnostic procedure including mammography supplemented by ultrasonography, fine needle aspiration cytology and clinical examination. The radiologist and pathologist are working together in the breast diagnostic centre and are thus able to give a "single visit diagnosis" in most cases. The surgeon sees the patient either the same day or the next. A "consensus meeting" held each week with representatives for all specialities present has an important function in quality assurance and education. If one or more of the triple diagnostic components reach conclusion level "suspicious lesion", surgery is indicated. In hospital management is based on day surgery for all biopsies, wide excisions with or without sentinel node and some ablatio simplex mammae. For wide excision and ablation with complete axillary node clearance, the patients are transferred from the day surgery unit to a patient hotel after 3-4 hours of observation and stay till the drain can be removed. Only in rare case of high cardiopulmonary risk, beds in ordinary wards are used. This is a highly cost efficient logistic saving the hospital approximately 400,000 EUR a year compared to ordinary in hospital treatment.

Breast Neoplasms↗

PubMed2002

The effect of long-term treatment with steroid hormones or tamoxifen on oestrogen receptors (alpha and beta) in the endometrium of ovariectomized cynomolgus macaques.

The effects of oestrogen are mediated by two specific intracellular receptors, oestrogen receptors (ER) alpha and beta, which function as ligand-activated transcriptional regulators. Ovariectomized macaques (Macaca fascicularis) were used to study the regulation of ERalpha and ERbeta in the endometrium by immunohistochemistry and in situ hybridization after long-term hormone treatment. Animals were treated continuously for 35 Months with either conjugated equine oestrogen (CEE), medroxyprogesterone acetate (MPA), combined CEE/MPA, or tamoxifen (TAM). Treatment with CEE/MPA down-regulated ERalpha in the superficial glands. In the superficial stroma the ERalpha level was lower in the CEE/MPA group than in the CEE and MPA groups. ERbeta immunostaining was faint with minor variation in response to treatment, but increased in the superficial stroma after MPA treatment. The ratio of ERbeta/ERalpha increased in superficial stroma and gland after CEE/MPA treatment, and also in stroma after MPA and TAM. Cystic endometrial hyperplasia was observed in TAM-treated animals, in combination with a high level of ERalpha protein expression. The present data show that long-term hormone treatment affects the ERalpha and ERbeta protein levels in the endometrium. The balance between ERalpha and ERbeta seems to be important for the proliferative response to oestrogen.

Animals↗

PubMed2002

Efficient method to generate homologous recombinant baculovirus genomes in E. coli.

Here we describe a convenient method to generate homologous recombinant baculoviral genomes in E. coli. The recombination takes place with the aid of recombination enzymes provided by the phage lambda Red system between a bacmid (a baculoviral genome that can replicate in bacteria) and a linear fragment. Proof of concept was provided when the cathepsin gene (v-cath) of the Helicoverpa armigera single nucleocapsid nucleopolyhedrovirus (HaSNPV) was replaced by the chloramphenicol resistance gene (CmR). First, CmR was inserted between the flanking sequences of the HaS-NPV v-cath. Each of the flanking regions was about 1 kb. The fragment was linearized and electroporated into bacteria containing both the HaSNPV bacmid and the lambda Red system. Recombinant bacmids resistant to chloramphenicol were selected. In comparison to the standard co-transfection/plaque assays, this method significantly reduces the time required to construct baculovirus knockout mutants. It may also be useful in the manipulation of other large viral genomes.

Baculoviridae↗

PubMed2002

Non-linear transform-based robust adaptive latency change estimation of evoked potentials.

OBJECTIVES: To improve the latency change estimation of evoked potentials (EP) under the lower order alpha-stable noise conditions by proposing and analyzing a new adaptive EP latency change detection algorithm (referred to as the NLST). METHODS: The NLST algorithm is based on the fractional lower order moment and the nonlinear transform for the error function. The computer simulation and data analysis verify the robustness of the new algorithm. RESULTS: The theoretical analysis shows that the iteration equation of the NLST transforms the lower order alpha-stable process en (k) into a second order moment process by a nonlinear transform. The simulations and the data analysis showed the robustness of the NLST under the lower order alpha-stable noise conditions. CONCLUSIONS: The new algorithm is robust under the lower order alpha-stable noise conditions, and it also provides a better performance than the DLMS, DLMP and SDA algorithms without the need to estimate the alpha value of the EP signals and noises.

Algorithms↗

PubMed2001

Elevated levels of connective tissue growth factor, WISP-1, and CYR61 in primary breast cancers associated with more advanced features.

To gain insight into the role of the CCN genes in human breast carcinomas, we quantified connective tissue growth factor (CTGF), WISP-1, CYR61, and human NOV (NOVH) mRNA expression levels in samples from 44 primary breast tumors and seven normal breasts using quantitative real-time PCR assay. Overexpression of CTGF, WISP-1, CYR61, and NOVH was found in 55 (24 of 44), 46 (20 of 44), 39 (17 of 44), and 11% (5 of 44) primary breast tumors, respectively. Statistical univariate analysis was performed to explore the links between expression of the CCN genes and clinical and pathological parameters. Interestingly, significant associations were found between CTGF expression versus stage, tumor size, lymph node status, and age at diagnosis; WISP-1 mRNA levels versus stage, tumor size, lymph node, and HER-2/neu overexpression; and CYR61 expression with stage, tumor size, lymph node, age, and estrogen receptor expression. In contrast to CTGF, WISP-1, and CYR61, no significant correlation was found between NOVH expression and any of the clinical and pathological factors. Furthermore, multivariate classification tree model analysis showed that stage and lymph node involvement were important for predicting CTGF expression in breast cancers; the stage, age, and HER-2/neu status were key factors for WISP-1 expression; and the stage, age, and estrogen receptor were valuable predictors for CYR61 expression. In summary, these results suggest that CTGF, WISP-1, and CYR61 may play a role in the progression of breast cancer and might serve as a valuable tool for monitoring tumor status of breast cancer patients.

Breast Neoplasms↗

PubMed2001

Destruction of the global phase coherence in ultrathin, doubly connected superconducting cylinders.

In doubly connected superconductors, such as hollow cylinders, the fluxoid is known to be quantized, allowing the superfluid velocity to be controlled by an applied magnetic flux and the sample size. The sample-size-induced increase in superfluid velocity has been predicted to lead to the destruction of superconductivity around half-integer flux quanta. We report transport measurements in ultrathin Al and Au0.7In0.3 cylinders verifying the presence of this destructive regime characterized by the loss of the global phase coherence and reveal a phase diagram featuring disconnected phase coherent regions, as opposed to the single region seen in larger superconducting cylinders studied previously.

Journal Article↗

PubMed2001

Large nondipole effects in the angular distributions of K-shell photoelectrons from molecular nitrogen.

Measurements of angular distributions of K-shell electrons photoejected from molecular nitrogen are reported which reveal large deviations at relatively low photon energies (Planck's omega < or = 500 eV) from emission patterns anticipated from the dipole approximation to interactions between radiation and matter. A concomitant theoretical analysis incorporating the effects of electromagnetic retardation attributes the observed large nondipole behaviors in N2 to bond-length-dependent terms in the E1 [multiply sign in circle] (E2,M1) photoelectron emission amplitudes which are indicative of a potentially universal nondipole behavior in molecular photoionization.

Journal Article↗

PubMed2001

[Monitoring and intervention of infant mortality rate and fetal and infant mortality rate in Beijing, 1992-2000].

OBJECTIVE: To monitor the changing trend of infant mortality rate (IMR) and fetal and infant mortality rate (FIM) in Beijing and to develop proper measures to decrease these two rates. METHODS: Dynamic series analysis was used to analyze the monitoring data of 590,833 cases of live birth, 5,835 cases of infant death, and 10,499 cases of stillbirth in Beijing during 1992-2000. The interventional measures in different phases were analyzed too. RESULTS: The IMR and FIMR in Beijing were 12.42% and 19.43% respectively in 1992 and were reduced to 6.84% and 15.79% respectively in 2000. The IMR and FIMR were declining significantly during the periods of 1992-1994, 1995-1997, and 1998-2001 (P < 0.01). The decrease of IMR by 48% was more remarkable than that of FIMR by 19%. The IMR I rural areas was higher than that in urban area. Pneumonia dropped from the position of the first death cause for infants to the fourth cause and congenital heart disease became the first cause. CONCLUSION: FIMR helps more comprehensively evaluate the effect of maternal and child health care. Monitoring and intervention of congenital heart diseases is very important.

Cause of Death↗

PubMed2001

[Relationship between serum 1,25-dihydroxyvitamin D and bone loss in postmenopausal women].

OBJECTIVE: To study the correlations between loss of activity and/or amont of serum 1,25-dihydroxyvitamin D(1,25(OH)2D) and 25-dihydroxyvitamin D(1,25(OH)2D) and bone loss in postmenopausal women, in order to reveal the possible pathophysiology of postmenopausal osteoporosis. METHODS: The serum levels of 1,25 (OH)2D, 25 (OH) D, PTH, and E2 in 57 postmenopausal women with osteoporosis and 37 postmenopausal women without osteoporosis were measured by radioimmunology. Their Dpd/Cr in urine was measured by ELISA. The bone mineral density (BMD) at lumbar spine (L2-4) was measured in each subject by DEXA. RESULTS: The serum 1,25(OH)2D in postmenopausal oeteoporotic women and non-osteoporotic women were 18 pg/ml +/- 6 pg/ml and 31 pg/ml +/- 14 pg/ml respectively (P < 0.01) The serum 25 (OH)2D in postmenopausal oeteoporotic women and non-osteoporotic women were 32 ng/ml +/- 9 ng/ml and 46 ng/ml +/- 17 ng/ml respectively (P < 0.01). Postmenopausal osteoporotic women had a lower estrogen concentration (P < 0.01), higher serum parathyroid hormone (PTH) (P < 0.01) and higher urinary Dpd/Cr level (P < 0.01). The level of serum 1,25(OH)2D was highly correlated with BMD in L2-4 for postmenopausal women (r = 0.693, P < 0.001). There was a close relationship between the serum level of 1,25(OH)2D and serum level of 25(OH)2D, suggesting an association between the two factors. CONCLUSION: The lower bone mass density was associated with lower level of serum 1,25-dihydroxyvitamin D, accompanied by reduced serum estrogen and elevated serum PTH in postmenopausal women. Those may be among the important pathphysiological changes of postmenopausal osteoporosis.

Aged↗

PubMed2001

Pleureryn, a novel protease from fresh fruiting bodies of the edible mushroom Pleurotus eryngii.

A protease designated pleureryn, with an N-terminal sequence dissimilar from previously reported mushroom metalloendopeptidases and showing only limited resemblance to aspartic proteinases, albeit considerable homology to DNA replication licensing factor, was isolated from fresh fruiting bodies of the edible mushroom Pleurotus eryngii. The purification protocol entailed ion exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel Blue gel, ion exchange chromatography on CM-Sepharose, and FPLC-gel filtration on Superdex 75. The protease was unadsorbed on DEAE-cellulose but adsorbed on Affi-gel Blue gel and CM-Sepharose. It demonstrated a single band with a molecular weight of 11.5 kDa in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Pleureryn demonstrated a protease activity of 9364 U/mg toward casein. It exhibited a pH optimum of 5.0 and a temperature optimum of 45 degrees C, with substantial activity remaining at high temperatures and pH 4 and 12. The activity of the protease was adversely affected by pepstatin A, indicating that it is an aspartic protease. PMSF, trypsin inhibitor, and EDTA exerted no striking effect, suggesting that it is neither a serine protease nor a metalloprotease. It inhibited translation in a rabbit reticulocyte lysate system with an IC(50) of 20 nM. Pleureryn also exhibited some inhibitory activity against HIV-1 reverse transcriptase, reminiscent of a suppressive action of HIV-1 protease on its homologous reverse transcriptase but was devoid of ribonuclease, deoxyribonuclease, and antifungal activities.

Amino Acid Sequence↗

PubMed2001

1,3-dichloro-1,1-dimethyl-3,3-diisopropyldistannoxane.

The title compound, [Sn4(CH3)4(C3H7)4Cl4O2] or [Cl[(CH3)2CH]2SnOSn(CH3)2Cl]2, obtained by the reaction of [(CH3)2CH]2SnO and (CH3)2SnCl2, exists as centrosymmetric dimers in the solid state. It contains a central planar four-membered Sn2O2 ring. The coordinate geometry about the Sn atoms is distorted trigonal pyramidal.

Journal Article↗

PubMed2001

Tomato yellow leaf curl China virus: monopartite genome organization and agroinfection of plants.

The complete DNA sequence (2734 nucleotides) of the monopartite genome of tomato yellow leaf curl China virus (TYLCCNV), a begomovirus transmitted by the whitefly Bemisia tabaci, was determined. The circular genomic DNA contains six open reading frames (ORFs) encoding proteins of molecular weights >10 kDa, of which two (V1 and V2) are located on the virion-sense strand and four (C1, C2, C3 and C4) on the complementary-sense strand. The ORFs are comparable to those of other whitefly-transmitted begomoviruses with a monopartite genome and to those encoded by DNA-A of bipartite begomoviruses. Sequence comparisons with other geminiviruses showed that TYLCCNV belongs to Begomovirus from the Old World. No putative DNA-B genome was found. Nicotiana species and tomato plants agroinoculated with the TYLCCNV monopartite genome developed typical yellowing and leaf-curling symptoms. The cloned molecule carried all the information needed for virus replication and systemic infection of plants.

China↗

PubMed2001

Long-term urinary function after transperineal brachytherapy for patients with large prostate glands.

PURPOSE: To summarize longer-term postbrachytherapy morbidity in patients with prostate glands >50 cm3. METHODS AND MATERIALS: From 1997 to 1998, 33 patients with a transrectal ultrasound-based prostate volume >50 cm3 were treated at the University of Washington by 125I (144 Gy) or 103Pd (115 Gy) implantation for prostate carcinoma. These 33 patients comprised 7% of the total implant patient population. Twelve patients were treated with neoadjuvant androgen ablation before implantation. The (125)I source strength ranged from 0.34 to 0.5 mCi and the 103Pd source strength ranged from 1.1 to 1.4 mCi (pre-NIST-99). The total number of sources implanted was 94-223 (median 155). Despite the typical implant-related volume increase, the postimplant CT-defined prostate volumes were generally well-covered by the prescription isodose (median coverage 92%, range 80-100%). The preimplant urinary obstructive symptoms were quantified by the criteria of the American Urological Association. RESULTS: Of the 33 patients, 12 developed acute postimplant urinary retention, all presenting within 24 h of implantation. Patients who developed postimplant retention lasting >1 week were generally treated with intermittent self-catheterization. By 1 month, 85% of patients were catheter free. By 1 year, only 1 patient (4%) remained in urinary retention; the remainder of cases had resolved spontaneously. With follow-up of 1.7-2.6 years, the last American Urological Association scores were higher than the pretreatment scores in 15 patients and lower in 7 patients. No patient developed permanent urinary incontinence. Long-term changes in the American Urological Association scores were unrelated to whether the patient had been in urinary retention after implantation. Two patients developed rectal fistulas; they had preimplant transrectal ultrasound prostate volumes of 53 and 59 cm3, in the low range for this group of patients. No other patient had persistent rectal bleeding suggestive of clinically significant proctitis. The pretreatment serum prostate-specific antigen level was 3.3-15 ng/mL (median 7.2) and the last serum prostate-specific antigen level 0.1-1.6 ng/mL (median 0.2). CONCLUSION: Patients with larger prostate volumes appear to have moderate morbidity and a satisfactory technical outcome with brachytherapy. We do not believe the occurrence of two severe rectal complications was related to the prostate volume per se. Our experience and that of others calls into question the validity of using prostate volume as a criterion for patient suitability for prostate brachytherapy.

Brachytherapy↗

PubMed2001

Replication protein A2 phosphorylation after DNA damage by the coordinated action of ataxia telangiectasia-mutated and DNA-dependent protein kinase.

Replication protein A (RPA, also known as human single-stranded DNA-binding protein) is a trimeric, multifunctional protein complex involved in DNA replication, DNA repair, and recombination. Phosphorylation of the RPA2 subunit is observed after exposure of cells to ionizing radiation (IR) and other DNA-damaging agents, which implicates the modified protein in the regulation of DNA replication after DNA damage or in DNA repair. Although ataxia telangiectasia-mutated (ATM) and DNA-dependent protein kinase (DNA-PK) phosphorylate RPA2 in vitro, their role in vivo remains uncertain, and contradictory results have been reported. Here we show that RPA2 phosphorylation is delayed in cells deficient in one of these kinases and completely abolished in wild-type, ATM, or DNA-PK-deficient cells after treatment with wortmannin at a concentration-inhibiting ATM and DNA-PK. Caffeine, an inhibitor of ATM and ATM-Rad3 related (ATR) but not DNA-PK, generates an ataxia-telangiectasia-like response in wild-type cells, prevents completely RPA2 phosphorylation in DNA-PKcs deficient cells, but has no effect on ataxia-telangiectasia cells. These observations rule out ATR and implicate both ATM and DNA-PK in RPA2 phosphorylation after exposure to IR. UCN-01, an inhibitor of protein kinase C, Chk1, and cyclin-dependent kinases, has no effect on IR-induced RPA2 phosphorylation. Because UCN-01 abrogates checkpoint responses, this observation dissociates RPA2 phosphorylation from checkpoint activation. Phosphorylated RPA has a higher affinity for nuclear structures than unphosphorylated RPA suggesting functional alterations in the protein. In an in vitro assay for DNA replication, DNA-PK is the sole kinase phosphorylating RPA2, indicating that processes not reproduced in the in vitro assay are required for RPA2 phosphorylation by ATM. Because RPA2 phosphorylation kinetics are distinct from those of the S phase checkpoint, we propose that DNA-PK and ATM cooperate to phosphorylate RPA after DNA damage to redirect the functions of the protein from DNA replication to DNA repair.

Androstadienes↗

PubMed2001

Analysis of terpene compounds in Cimicifuga foetida L. by reversed-phase high-performance liquid chromatography with evaporative light scattering detection.

An RP-HPLC method with evaporative light scattering detection (ELSD) was developed for the analysis of terpene compounds in traditional Chinese medicine. Actein, 27-deoxyactein and cimicifugoside in a typical Chinese medicine of Cimicifuga foetida L. were quantitatively analyzed. Comparing ELSD with UV detection under the same eluent conditions, the former showed better sensitivity and a more stable baseline. The ELSD responses versus sample size of three terpenes and those in double logarithmic were investigated. The good calibration curves in double logarithmic coordinator for actein, 27-deoxyactein and cimicifugoside were obtained. Three solutions for the extraction of the terpene compounds were also compared, the results indicated that methanol-water (80:20) is the best among them. The method was applied to quantify actein, 27-deoxyactein and cimicifugoside in Cimicifuga foetida L. from Hunan, China. It was shown that ELSD is an effective detection method for the analysis of the non-volatile terpenes in traditional Chinese medicine.

Calibration↗