[Recent research on mycobacteremia].
Explore the source record for details and available documents.
AIDS-Related Opportunistic Infections↗
Biomedical subjects
G Huang
Publications and source records attributed to G Huang.
[Construction of a subtracted cDNA library of differentially expressed genes in human normal liver tissue and primary hepatocellular carcinoma tissue].
OBJECTIVE: To construct a subtracted cDNA library of differentially expressed genes in human normal liver tissue and primary hepatocellular carcinoma (HCC) tissue. METHODS: Using the suppression subtractive hybridization (SSH), a novel technique has been described recently. cDNA fragments of missing or low expressing tumor suppressor genes in HCC tissue were isolated using paracancerous normal liver tissue and HCC tissue as targets. Then these cDNA fragments were directly inserted into T/A cloning vector to set up the subtractive library. Amplification of the library was carried out with transformation of E.coli by high voltage electroperforation. One hundred positive bacteria clones were randomly picked and identified using enzyme restriction method. RESULTS: The amplified library contained more than 4,000 positive bacteria clones. Random analysis of 100 clones with enzyme restriction method showed that all clones contained 200-600 bp inserts. CONCLUSIONS: A subtracted cDNA library of differentially expressed genes in human normal liver tissue and HCC tissue is constructed successfully with SSH and T/A cloning techniques. The library is efficient and lays solid foundation for screening and cloning new and specific missing or low expressing tumor suppressor genes of HCC.
Carcinoma, Hepatocellular↗
[mRNA expression and mutation of MTA1 and nm23H1 genes in ovarian carcinoma in relation to lymph node metastasis].
OBJECTIVE: To investigate mRNA expression and mutation of MTA1 and nm23H1 genes in ovarian carcinoma (OC) in relation to lymph node (LN) metastasis. METHODS: A panel of eight normal ovarian tissues, twenty primary OC specimens and twenty corresponding LNs was examined for mRNA expression and mutation of MTA1 and nm23H1 genes by using RT-PCR and RT-PCR-SSCP. The level of expression was determined by the relative optic density (ROD) of the PCR products. RESULTS: The frequency of MTA1 overexpression was 100% (7/7) in primary OC with metastasis but only 38.5% (5/13) in those without metastasis (P = 0.0103). Overexpression of MTA1 was observed in 87.5% (6/7) of LNs with metastasis but in only 23% (3/13) of LNs without metastasis (P = 0.0118). In contrast with MTA1, low expression of nm23H1 mRNA was seen in 7 of 7 OC with metastasis but only in 4 of 13 (30%) of those without metastasis (P = 0.0043). Low nm23H1 expression was also seen in 7 of 7 LNs with metastasis but only in 5 of 13 (38.5%) nonmetastatic LNs (P = 0.0102). The ROD ratio of MTA1 to nm23H1 increased with the development of metastasis. No mutation of MTA1 and nm23H1 was found by SSCP analysis. CONCLUSION: The mRNA expression of MTA1 and nm23H1 is positively and negatively correlated with LN metastasis, respectively. Expression abnormalities but not mutation of the two genes are frequent events related to LN metastasis of ovarian cancer.
Down-Regulation↗
[A prospective, randomized controlled study comparing the effects of gonadotropin-releasing hormone agonist long and short protocols for in vitro fertilization].
OBJECTIVE: To compare the effects of gonadotropin-releasing hormone agonist (GnRH-a) long and short protocols as part of in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) treatment. METHODS: One hundred and nine infertile couples accepted a prospective, randomized comparative study for IVF or ICSI treatment were divided into GnRH-a long protocol group (55 cases) and GnRH-a short protocol group (54 cases). GnRH-a long protocol group: GnRH-a was taken by nasal spray 0.9 mg/day starting on day 21 of the previous menstrual cycle. Once the patient was down regulated, gonadotropin (Gn) injection was started. GnRH-a short protocol group: GnRH-a was taken by nasal spray 0.45 mg/day starting on day 2 of the menstrual cycle, and Gn was started on the same day. Two groups had human chorionic gonadotrophin (hCG) administered when the leading follicle was at least 18 mm in diameter. Oocytes were retrieved 36 hours after hCG administration guided by transvaginal ultrasounography. IVF/ICSI were performed as routine. RESULTS: Serum follicle stimulating hormone and luteinizing hormone (LH) levels on the day of starting Gn were lower in the long protocol group comparing with the short protocol group [(4.4 +/- 1.2) IU/L Vs (6.3 +/- 1.7) IU/L, (2.7 +/- 1.5) IU/L Vs (4.4 +/- 2.8) IU/L, P < 0.01 respectively]. The levels of serum estradiol (E2), LH and E2 per oocyte on the day of hCG injection were lower in the long protocol group comparing with the short protocol group [(7,119 +/- 3,584) pmol/L Vs (9,523 +/- 3,587) pmol/L, (1.0 +/- 1.0) IU/L Vs (4.0 +/- 3.4) IU/L, (610 +/- 315) pmol/L Vs (935 +/- 450) pmol/L, P < 0.01 respectively]. Patients treated with short protocol were stimulated for a shorter period, required fewer Gn ampoules than the long protocol group [(10.1 +/- 1.5) d Vs (11.1 +/- 1.2) d, (23.4 +/- 8.7) Amps Vs (28.0 +/- 8.6) Amps, P < 0.01 respectly]. There are no statistically differences between the two groups in the numbers of oocytes retrieved, metaphase of second meiosis oocytes, fertilized oocytes, cleaved embryos, high quality embryos and pregnancy rates. CONCLUSIONS: The GnRH-a long and short protocols have equal effects on controlled ovarian hyperstimulation for in vitro fertilization. Patients who received GnRH-a short protocol required fewer ampoules of gonadotrpins and shorter period of treatment than those who received the GnRH-a long protocol.
Adult↗
Outcome prediction in severe traumatic brain injury with transcranial Doppler ultrasonography.
OBJECTIVE: To investigate the value of transcranial Doppler (TCD) ultrasonography in evaluating the outcome of severe traumatic brain injury and to correlate the TCD values with intracranial pressure (ICP) and cerebral perfusion pressure (CPP) monitoring. METHODS: A prospective study was conducted to evaluate the contribution of TCD ultrasonography to neurological outcome in a series of 96 severe traumatic brain injury patients. The quantitative variables of TCD ultrasonography included the mean blood flow velocity of the middle cerebral artery (MCA) and pulsatility index within the first 24 hours of admission. The ICP and CPP values were a lso recorded. Outcome in 6 months postinjury was evaluated using the Glasgow Outcome Scale (GOS 4-5 was considered as "good" and GOS 1-3 as "poor"). RESULTS: The mean blood flow velocity of the MCA was larger than 40 cm/s in 30 (51%) patients with good outcome whereas it was less than 40 cm/s in 27 (73%) patients with poor outcome (P<0.025). The mean PI in cases of good outcome (34 patients, 57%) was lower than 1.5 whereas in poor outcome (30 patients, 83%) was higher than 1.5 (P<0.001). The correlations of ICP and CPP to pulsatility index were statistically significant (P<0.01). CONCLUSIONS: TCD ultrasonography is valid in predicting the patient's outcome of 6 months and correlates significantly with ICP and CPP values when it is performed in the first 24 hours of severe traumatic brain injury.
Adolescent↗
[Study of peak expiratory flow in normal young, middle-aged and old persons in Chengdu area].
OBJECTIVE: To build the normal ranges and regression equations of peak expiratory flow (PEF) in normal young, middle-aged and old persons. METHODS: PEF, FVC, V75, V50, V25 were measured in 393 normal young, middle-aged and old persons with the youngest aged 20 years and the eldest 84 years. Regression equations of PEF were built for younger group (20 yr-49 yr) and elder group (50 yr-84 yr) respectively. RESULTS: PEF, FVC, V75, V50, V25 were decreased with increase of age. The regression equations showed that both in younger and elder groups, PEF was negatively correlated with age in male (P < 0.0001-0.002, r = 0.32-0.39) and positively correlated with FVC in female (P < 0.0001-0.0005, r = 0.32-0.59). PEF was highly correlated to V75 with r = 0.87-0.94 in male and r = 0.93-0.96 in female. The coefficient of variation (CV) of PEF was in normal range (16%-24%) for all age groups except male and female above 70 years old with CV of 30% and 27% respectively. This confirmed the data was reliable. CONCLUSION: The normal ranges and regression equations of PEF constructed as a result of this study for normal humans of 20-84 years old can be put to use in clinical work and public health.
Adult↗
[Study of peak expiratory flow in 728 normal adolescents in Chengdu area].
OBJECTIVE: This study was carried out to build the normal values and regression equations of peak expiratory flow (PEF) in normal adolescents. METHODS: PEF and routine ventilatory functions, FVC, V75, V50, V25 were measured in 728 normal adolescents aged 8-19. RESULTS: The PEF and FVC, V75, V50, V25 rose with the increase of age. The regression equations showed that PEF was highly positively correlated with age and FVC both in male and female adolescents, and also positively correlated with body weight in males; the coefficients of multiple correlation were 0.85 and 0.78 in male and female ones respectively. Correlations of PEF with V75, V50, V25 were also high, especially with V75 of which the correlation coefficients came up to 0.98 both in male and female adolescents. The coefficients of variation were 15%-20% both in male and female adolescents, and were in normal ranges. CONCLUSION: The normal ranges and regression equations of PEF provided for normal adolescents can be used to evaluate the pulmonary functions of patients who are in the same age-group suffering from bronchial asthma and other respiratory diseases.
Adolescent↗
[Determination of puerarin in three traditional Chinese patent medicines by high performance liquid chromatography].
A simple and accurate reversed-phase high performance liquid chromatographic method to determine puerarin in three traditional Chinese patent medicines, namely "Xiao'er qingganling" tablet, "Buchang xinnaoxintong" capsulae and "Ganmao qingre" granule is described. "Xiao'er qingganling" tablet and "Buchang xinnaoxintong" capsulae were extracted with methanol in an ultrasonic bath and "Ganmao qingre" granule was extracted with water and ethanol. After being centrifuged and filtered, the samples were separated on an ODS column with a mobile phase of 100 mmol/L ammonium acetate buffer (pH 5.0)-methanol(75:25, volume ratio). The flow rate was 0.8 mL/min, and the detection wavelength was 250 nm. The calibration curve was linear in the range of 2 mg/L-20 mg/L puerarin (r = 0.9999). The average recoveries were 99.0%, 93.4% and 97.5% for "Xiao'er qingganling" tablet, "Buchang xinnaoxintong" capsulae, "Ganmao qingre" granule respectively. The average contents of puerarin in the medicines were 3.48 mg/g, 1.08 mg/g and 1.52 mg/g (sucrose), and the relative standard deviations were 1.9%, 1.4% and 1.4% respectively.
Chromatography, High Pressure Liquid↗
[Changes of tangent time constant in the transformation of F-V curve configuration in COPD and cor pulmonale patients and clinical implications].
OBJECTIVE: To explore the changes of tangent time constant (tau t) in the transformation of F-V curve configuration in COPD and cor pulmonale patients and clinical implications. METHODS: We determined the F-V curves in 90 COPD patients (43 with chronic bronchitis, 47 with emphysema) and 31 complicated with cor pulmonale; all patients were in the ameliorated period. The tau t at high, mid and low lung volumes, tau t75, tau t50, tau t25, were measured on each F-V curve. RESULTS: 1. Normal ranges: F-V curve configuration with plateau, linear, convex and concave types; |tau t75| > ls or < ls; tau t25 < ls; tau t relationship with "adolescent fashion" or "old fashion". 2. Light and moderate abnormality: With convex type; |tau t75| < ls; tau t25 approximately = ls or > ls; "trumpet fashion" changes. 3. Serious abnormality: With hyperbolic type; |tau t75| < ls; tau t25 = 4s-10s; "tower fashion" changes. CONCLUSION: Hyperbolic type, extreme prolongation of tau t25 and "tower fashion" changes can be assigned as 3 important indices to assess the severity of disease. The convenience and correctness of the method may be available for clinical application.
Adult↗
[On the characteristics of velocity modulation laser spectroscopy].
The technical properties of velocity modulation laser spectroscopy were investigated using the spectrum of A2 pi u-X2 sigma g+ (2-0) band of Meinel system of N2+. The dependence of spectral intensity on discharge current, the pressure of the gas mixture and the pump velocity of the vacuum pump were studied. Making uses of the results of these studies, the sensitivity and resolution of the spectrometer are improved by above 3 times, and economized the experimental expenses can be reduced to as 3/4 time as normal, which confirms that the results of this paper is of considerable uses.
Lasers↗
[Assignments of FIR-LMR spectra of CF X 2Pi (nu = 1) and MIR-LMR spectra of NO X 2Pi (nu = 1<--0)].
According to the theories of Zeeman effect and the principle of laser magnetic resonance (LMR), a method and model for the analysis of the laser magnetic resonance spectra were developed and successfully employed to assign the FIR-LMR spectra of CF X2 Pi (nu = 1) and the MIR-LMR spectra of NO X 2Pi (nu = 1<--0). This work provided an efficient and accurate approach for primary analysis of the LMR spectra of novel radicals.
English Abstract↗
[The effect of monocarboxylate transporter gene on the regulation of pHi and growth character in cancer cells].
OBJECTIVE: To study the influence of the first subtype of monocarboxylate transporter (MCT1) gene on pHi regulation, lactate transport and cell growth in tumor cells. METHODS: (1) With RT-PCR technique, MCT1 cDNA fragment was cloned from human lung cancer cells A549, and the cloned fragment MCT1 was reversely inserted into the vector pLXSN to acquire antisense expression recombinant vector pLXSN-MCT1. (2) pLXSN, pLXSN-MCT1 were respectively introduced into the A549 cells by electroporation. The transfected A549 cell resistant to G418 drug was selected as positive clones and proved by PCR. The changes of intracellular pH and lactate in the transfected A549 cells were detected by spectrophotometric method. Cell growth was studied by cell growth curve. RESULTS: (1) The cloned fragment was in the length of 640 bp and successfully bound to pLXSN. It was also proved to be the objective one by DNA sequencing. (2) Intracellular pH and lactate were remarkably decreased in the cells transfected pLXSN-MCT1, comparing to A549 cells without transfection (P < 0.001). The growth of A549 cells transfected pLXSN-MCT1 was also inhibited remarkably. CONCLUSION: MCT1 gene could play an important role in pHi regulation, lactate transport and cell growth in tumor cells.
Adenocarcinoma↗
[Recent advances of molecular abnormalities in lung cancer].
Explore the source record for details and available documents.
Adenocarcinoma↗
Characterization of the acyl carrier protein gene and the fab gene locus in Xanthomonas albilineans.
A genomic region containing the fatty acid biosynthetic (fab) genes was isolated from the sugarcane leaf-scald pathogen Xanthomonas albilineans. The order and predicted products of fabG (beta-ketoacyl reductase), acpP (acyl carrier protein), fabF (ketoacyl synthase II) and downstream genes in X. albilineans are very similar to those in Escherichia coli, with one exception. Sequence analysis, confirmed by insertional knockout and specific substrate feeding experiments, shows that the position occupied by pabC (encoding aminodeoxychorismate lyase) in other bacteria is occupied instead by pabB (encoding aminodeoxychorismate synthase component I) in X. albilineans. Downstream of pabB, X. albilineans resumes the arrangement common to characterized Gram-negative bacteria, with three transcriptionally coupled genes, encoding an ORF340 protein of undefined function, thymidylate kinase and delta' subunit of DNA polymerase III holoenzyme (HolB). Different species may obtain a common advantage from coordinated regulation of the same biosynthetic pathways using different genes in this region.
Acyl Carrier Protein↗
Albicidin antibiotic and phytotoxin biosynthesis in Xanthomonas albilineans requires a phosphopantetheinyl transferase gene.
Xanthomonas albilineans produces a family of highly potent antibiotics and phytotoxins called albicidins, which are key pathogenesis factors in the systemic development of leaf scald disease of sugarcane. A gene (xabA) required for albicidin biosynthesis encodes a peptide of 278 amino acids, including the signature sequence motifs for phosphopantetheinyl transferases (PPTases) that activate polyketide and non-ribosomal peptide synthetases. The Escherichia coli entD gene, which encodes a PPTase involved in biosynthesis of enterobactin (a siderophore), restored biosynthesis of albicidin (a DNA replication inhibitor) in X. albilineans Tox- LS156 (xabA::Tn5). We conclude that XabA is a PPTase required for post-translational activation of synthetases in the albicidin biosynthetic pathway. This is the first antibiotic or toxin biosynthesis gene characterized from the genus Xanthomonas, and the first demonstration that antibiotic synthetases in the Pseudomonadaceae, like those in the Enterobacteriaceae and in Gram-positive bacteria, can require activation by a PPTase. Coupled with the recent demonstration of a separate albicidin biosynthetic gene cluster, the results indicate the possibility for overproduction of albicidins,which allows better understanding and application of these potent inhibitors of prokaryote DNA replication.
Amino Acid Sequence↗
Analysis of the genes flanking xabB: a methyltransferase gene is involved in albicidin biosynthesis in Xanthomonas albilineans.
Transposon mutagenesis and complementation studies previously identified a gene (xabB) for a large (526kDa) polyketide-peptide synthase required for biosynthesis of albicidin antibiotics and phytotoxins in the sugarcane leaf scald pathogen Xanthomonas albilineans. A cistron immediately downstream from xabB encodes a polypeptide of 343aa containing three conserved motifs characteristic of a family of S-adenosyl-L-methionine (SAM)-dependent O-methyltransferases. Insertional mutagenesis and complementation indicate that the product of this cistron (designated xabC) is essential for albicidin production, and that there is no other required downstream cistron. The xabB promoter region is bidirectional, and insertional mutagenesis of the first open reading frame (ORF) in the divergent gene also blocks albicidin biosynthesis. This divergent ORF (designated thp) encodes a protein of 239aa displaying high similarity to several IS21-like transposition helper proteins. The thp cistron is not located in a recognizable transposon, and is probably a remnant from a past transposition event that may have contributed to the development of the albicidin biosynthetic gene cluster. Failure of 'in trans' complementation of thp indicates that a downstream cistron transcribed with thp is required for albicidin biosynthesis.
Amino Acid Sequence↗
A RUNX2/PEBP2alpha A/CBFA1 mutation displaying impaired transactivation and Smad interaction in cleidocranial dysplasia.
Cleidocranial dysplasia (CCD), an autosomal-dominant human bone disease, is thought to be caused by heterozygous mutations in runt-related gene 2 (RUNX2)/polyomavirus enhancer binding protein 2alphaA (PEBP2alphaA)/core-binding factor A1 (CBFA1). To understand the mechanism underlying the pathogenesis of CCD, we studied a novel mutant of RUNX2, CCDalphaA376, originally identified in a CCD patient. The nonsense mutation, which resulted in a truncated RUNX2 protein, severely impaired RUNX2 transactivation activity. We show that signal transducers of transforming growth factor beta superfamily receptors, Smads, interact with RUNX2 in vivo and in vitro and enhance the transactivation ability of this factor. The truncated RUNX2 protein failed to interact with and respond to Smads and was unable to induce the osteoblast-like phenotype in C2C12 myoblasts on stimulation by bone morphogenetic protein. Therefore, the pathogenesis of CCD may be related to the impaired Smad signaling of transforming growth factor beta/bone morphogenetic protein pathways that target the activity of RUNX2 during bone formation.
3T3 Cells↗
Conformational specificity of trigger factor for the folding intermediates of alpha-lactalbumin.
To understand the structural features of polypeptides recognized by trigger factor, a number of conformational derivatives of alphaLA were prepared and their effects on the trigger factor assisted refolding of GAPDH were investigated. It was found that the conformers of alphaLA that efficiently reduce the trigger factor assisted reactivation of guanidine-denatured GAPDH by competitively binding with trigger factor are those derivatives that have loose structure. This suggests that trigger factor binds mainly to intermediates formed early during folding of GAPDH.
Animals↗