Acute hyperglycemia rapidly suppresses endothelium-dependent arterial dilation in first-degree relatives of type 2 diabetic patients

OBJECTIVE

Previous studies showed that endothelium-dependent arterial dilation is impaired in first-degree relatives of type 2 diabetes in the fasting state. In the present study, we examined whether endothelial dysfunction occurs when acute hyperglycemia is induced by oral glucose loading in this cohort.

PATIENTS AND METHODS

This study included 32 normal glucose tolerant subjects. Of them, 17 with a family history (FH) of type 2 diabetic parents (FH+) and 15 with no first-degree relative with diabetes or coronary artery disease (FH-). The examination of vascular function was performed in fasting state and repeated 1 and 2 hours after a 75-g oral glucose loading by high resolution ultrasound.

RESULTS

Endothelium- dependent arterial dilation in FH+ group were significantly lower than those in FH- before and after oral glucose loading (5.12+/-0.61% vs 6.03+/-0.56%, fasting; 4.0+/-0.65% vs 5.70+/-0.42%, 1 h; 4.43+/-0.61% vs 5.82+/-0.67% 2 h, p<0.05 each). In FH+ group, endothelium-dependent arterial dilation decreased significantly at 60 min (4.0+/-0.65% vs 5.12+/-0.61%, p<0.01) and increased markedly from 60 min at 120 min (4.43+/-0.61% vs 4.0+/-0.65%, p<0.05), which was still significantly lower than baseline (4.43+/-0.61% vs 5.12+/-0.61%, p<0.01) . In FH- group, however, the arterial dilation did not differ significantly among the three time points (p 0.05). In multiple regression analysis, endothelium-dependent arterial dilation was significantly correlated to FH+(r=-0.302, p<0.01). In addition, endothelium-dependent arterial dilation showed a correlation with plasma glucose (r=-0.460, p<0.01) and TBARS (r=-0.382, p<0.01) during OGTT in FH+ subjects.

CONCLUSION

Significant endothelial dysfunction is present in the fasting state, hyperglycemia in response to oral glucose loading rapidly suppresses endothelium-dependent arterial dilation in FH+ subjects, probably through increased production of oxygen-derived free radicals.

Observation of Y(2175) in J/psi --> etaphif0 (980)

The decays of J/psi --> etaphif(0)(980)[eta --> gammagamma, phi --> K(+) K(-), f(0)(980) --> pi(+)pi(-)] are analyzed using a sample of 5.8 x 10(7) J/psi events collected with the BESII detector at the Beijing Electron-Positron Collider. A structure at around 2.18 GeV/c(2) with about 5 sigma significance is observed in the phif(0)(980) invariant mass spectrum. A fit with a Breit-Wigner function gives the peak mass and width of m = 2.186+/-0.010(stat)+/-0.006(syst) GeV/c(2) and Gamma = 0.065+/-0.023(stat)+/-0.017(syst) GeV/c(2), respectively, which are consistent with those of Y(2175), observed by the BABAR Collaboration in the initial-state radiation process e(+)e(-) --> gamma(ISR) phif(0)(980). The production branching ratio is determined to be Br(J/psi --> etaY(2175))Br(Y(2175)- -> phif(0)(980))Br(f(0)(980) --> pi(+)pi(-)) = [3.23+/-0.75(stat)+/-0.73(syst)] x 10(-4), assuming that the Y(2175) is a 1(--) state.

Coherent combining technology of master oscillator power amplifier fiber arrays

Coherent beam combination of fiber laser array is an important technology of realize high-power, high-radiance fiber laser system. In this paper, Master Oscillator-Power Amplifier scheme is used to realize phase controlling of three ytterbium fiber amplifiers, the experiment results of both two and three fiber amplifiers are given and compared. Far-field patterns with different fill factor are studied experimentally. We perform optical phase-noise measurements of a commercial 1-W ytterbium fiber amplifier using our phase control electronics, the dominant phase noises of the 1-W fiber amplifier are at frequencies below one kilohertz.

Effect of the reversal of coenzyme specificity by expression of mutated Pichia stipitis xylitol dehydrogenase in recombinant Saccharomyces cerevisiae

AIMS

To determine the effects on xylitol accumulation and ethanol yield of expression of mutated Pichia stipitis xylitol dehydrogenase (XDH) with reversal of coenzyme specificity in recombinant Saccharomyces cerevisiae.

METHODS AND RESULTS

The genes XYL2 (D207A/I208R/F209S) and XYL2 (S96C/S99C/Y102C/D207A/I208R/F209S) were introduced into S. cerevisiae, which already contained the P. stipitis XYL1 gene (encoding xylose reductase, XR) and the endogenously overexpressed XKS1 gene (encoding xylulokinase, XK). The specific activities of mutated XDH in both strains showed a distinct increase in NADP(+)-dependent activity in both strains with mutated XDH, reaching 0.782 and 0.698 U mg(-1). In xylose fermentation, the strain with XDH (D207A/I208R/F209S) had a large decrease in xylitol and glycerol yield, while the xylose consumption and ethanol yield were decreased. In the strain with XDH (S96C/S99C/Y102C/D207A/I208R/F209S), the xylose consumption and ethanol yield were also decreased, and the xylitol yield was increased, because of low XDH activity.

CONCLUSIONS

Changing XDH coenzyme specificity was a sufficient method for reducing the production of xylitol, but high activity of XDH was also required for improved ethanol formation.

SIGNIFICANCE AND IMPACT OF THE STUDY

The difference in coenzyme specificity was a vital parameter controlling ethanolic xylose fermentation but the XDH/XR ratio was also important.

High prevalence of pineal cysts in healthy adults demonstrated by high-resolution, noncontrast brain MR imaging

BACKGROUND AND PURPOSE

Although the prevalence of pineal cysts in autopsy series has been reported as being between 25% and 40%, MR studies have documented their frequency to range between 1.5% and 10.8%. The purpose of this high-resolution brain MR imaging study at 1.9T was to determine the prevalence of pineal cysts in healthy adults.

MATERIALS AND METHODS

Brain MR images of 100 healthy young volunteers were randomly selected from our International Consortium for Brain Mapping project data base. Cysts were detected as circular areas of isointensity relative to CSF on both 3D gradient-echo T1-weighted and 2D fast spin-echo T2-weighted images. The inner diameters of all visualized pineal cysts were measured, and a criterion of 2.0 mm of the largest inner cross-sectional diameter was used to categorize cysts as being either small cystic changes (<2.0-mm diameter) or pineal cysts (>2.0-mm diameter).

RESULTS

Twenty-three percent (23/100) of the volunteers had pineal cysts with a mean largest inner cross-sectional diameter of 4.3 mm (range, 2-14 mm); 13% (13/100) demonstrated cystic changes involving the pineal gland with the largest inner cross-sectional diameter of less than 2.0 mm. There was a slight female predominance. Two subjects with long-term follow-up scans showed no symptoms or changes in the size of their pineal cysts.

CONCLUSION

On high-resolution MR imaging, the prevalence of pineal cysts was 23% in our healthy group of adults, which is consistent with previous autopsy studies. Long-term follow-up studies of 2 cases demonstrated the stability of the cysts.

Measurement of psi2S radiative decays

Using 14 x 10(6) psi(2S) events accumulated at the BESII detector, we report first measurements of branching fractions or upper limits for psi(2S) decays into gammapp, gamma2(pi+pi-), gammaKS0K+pi-+c.c., gammaK+K-pi+pi-, gammaK*0K-pi++c.c., gammaK*0K*0, gammapi+pi-pp, gamma2(K+K-), gamma3(pi+pi-), and gamma2(pi+pi-)K+K- with the invariant mass of hadrons below 2.9 GeV/c2. We also report branching fractions of psi(2S) decays into 2(pi+pi-)pi0, omegapi+pi-, omegaf2(1270), b1+/-pi-/+, and pi02(pi+pi-)K+K-.

Vandetanib in metastatic hereditary medullary thyroid cancer: Follow-up results of an open-label phase II trial

6018

Background: Medullary thyroid cancer (MTC) is the most common cause of death in patients with hereditary syndromes caused by activating mutations in the RET protooncogene. RET activation is the initial oncogenic event, with the activity of other receptor tyrosine kinases, including VEGFR and EGFR, likely to contribute to tumor growth and metastasis. Vandetanib (ZD6474) is a once- daily oral agent that selectively targets RET, VEGFR and EGFR tyrosine kinases. Methods: Eligible patients had unresectable, measurable, locally advanced or metastatic hereditary MTC and a RET germline mutation. Patients received vandetanib 300 mg/day until disease progression or any other withdrawal criteria. The primary objective was to assess the objective tumor response (RECIST every 3 months). Secondary assessments included disease control rate, biochemical response (determined by decrements in plasma levels of calcitonin, a tumor marker for MTC) and safety and tolerability. Results: Thirty patients (21 female; median age 50 years) received initial treatment with vandetanib 300 mg. At data cut-off (20 Nov 2006), the median duration of treatment was 172 days. Based on site investigator assessments, 20% (6/30) of patients experienced a partial response (duration of response 59–260 days) and another 30% (9/30) of patients experienced stable disease =24 weeks, yielding a disease control rate of 50% (15/30). Centralized independent confirmation of response is planned. In 19 patients, plasma calcitonin levels showed a =50% decrease from baseline that was maintained for at least 6 weeks. Adverse events (AEs) occurring in >50% of patients were rash (73%), diarrhea (67%), fatigue (57%) and nausea (53%). Most AEs were grade 1 or 2; grade 3 AEs included asymptomatic QTc prolongation (n=5), rash and diarrhea (both n=3), all of which were manageable. Conclusions: Vandetanib has demonstrated clinical activity in this phase II study in metastatic hereditary MTC, and the safety profile is generally consistent with previous vandetanib monotherapy studies. Accrual is now complete (30 patients), and an updated analysis will be performed in April 2007. An international, randomized, placebo-controlled phase II trial of vandetanib in MTC is now recruiting patients. #

No significant financial relationships to disclose.

Predictive significance of bone sialoprotein and osteopontin for bone metastases in respectable non-small cell lung cancer: A retrospective study

7666

Background: Bone sialoprotein (BSP) and osteopontin (OPN) have been demonstrated predictive of bone metastases in breast and prostate carcinoma, consistent with the proposed role of BSP as a stimulator of bone mineralization and OPN in differentiation and activation of osteoclasts. Bone metastasis (BM) is often developed in non-small-cell lung cancer (NSCLC), but no predictive biomarker was identified for high risk of metastatic bone dissemination. Methods: 180 completely resected NSCLC patients were included in this study. 38 patients subsequently developed BM. Paraffin embedded primary tumor tissue of patients were supplied to produce a tissue microarray, and immunohistochemistry method was used for evaluation the expression of BSP and OPN. Different expressions of these two biomarkers among BM group and non-BM group were estimated by χ2 test. Bone metastasis-free survival was analyzed by Kaplan-Meier method. The prognostic impact of clinicopathologic parameters and biomarker expression was evaluated by Cox propotional hazards model. Results: BSP expression was associated with BM (P=0.027), while OPN expression could not reach statistical significance (P=0.495). Univariate analysis demonstrated that expression of BSP (P=0.036), N stage (P=0.000) and clinical stage (P=0.001) were associated with time interval to BM. Multivariate analyses showed BSP expression (RR=1.779, P=0.012) and clinical stage (RR=1.620, P=0.005) were independent prognostic factors for BM. Conclusions: BSP protein expression in the primary resected NSCLC is strongly associated with BM and could be used to identify high-risk patients. Correlation of OPN protein expression and bone metastasis need further investigation.

No significant financial relationships to disclose.

Distribution and characteristics of hepatitis B virus genotype C subgenotypes in China

Genetic diversity within the same hepatitis B virus (HBV) genotype indicates the presence of several subgenotypes. We have found that genotype C is the most common in China, and this study aimed to determine the geographical distribution and characteristics of HBV-C subgenotypes in the country. A cohort of 534 patients with chronic HBV genotype C infection, collected across China, was analysed by nucleotide sequencing or polymerase chain reaction-restriction fragment length polymorphism. HBV-C1/Cs (n = 112, 21%) and HBV-C2/Ce (n = 397, 74%) were the most common HBV-C subgenotypes and showed different geographical distribution in China. No significant differences were found between patients infected with HBV-C1 and HBV-C2 when comparing liver function tests, hepatitis B e antigen positive rate and clinical manifestations. We identified two other types of HBV-C provisionally designated as HBV-CD1 and HBV-CD2, which have particular virological features and clustered in one geographic area. These two types of C/D hybrids have emerged through recombination with genotype D and encode serotype ayw2 hepatitis B surface antigen. In conclusion, there are at least four subtypes of HBV genotype C: subgenotypes C1, C2 and two types of C/D recombinants CD1 and CD2 in China, which have a distinct geographic distribution. Whether HBV-C subgenotypes differ in their impact on liver disease progression requires prospective studies.

Transcriptional silencing of the TMS1/ASC tumour suppressor gene by an epigenetic mechanism in hepatocellular carcinoma cells

DNA methylation and histone modifications have emerged as key mechanisms in transcriptional regulation. The target of methylation-induced silencing 1 (TMS1) is a bipartite protein. Recent studies have indicated that methylation-associated silencing of TMS1 occurs in many cancers. However, whether and how TMS1 is regulated by epigenetic mechanisms in cancers remains unknown. In this study we showed that methylation of the TMS1 promoter occurred in five of six hepatocellular carcinoma (HCC) cell lines. TMS1 expression was reduced in four HCC cell lines and correlated with methylation status. Furthermore, the TMS1 promoter was completely methylated and mRNA expression was undetectable. TMS1 expression could be restored by 5-aza-2'-deoxycitidine (5-Aza-dC) (a DNA methyltransferase inhibitor) or trichostatin A (TSA) (a histone deacetylase inhibitor) alone and the promoter methylation was partially reversible. TSA was more efficient than 5-Aza-dC in inducing TMS1 expression, and the combination of 5-Aza-dC and TSA resulted in markedly synergistic reactivation of the gene and completely reversed promoter methylation. Interestingly, TMS1 promoter methylation-associated gene silencing was accompanied by histone H3 Lysine 9 (H3K9) hypoacetylation and trimethylation. 5-Aza-dC and/or TSA also had some effect on conversion of methylated to acetylated H3K9 in restoring TMS1. This conversion was dynamic at the TMS1 promoter and a decrease in H3K9 trimethylation preceded an increase in H3K9 acetylation after 5-Aza-dC and/or TSA treatment. Our results thus suggest that epigenetic inactivation of TMS1 expression is regulated by promoter hypermethylation and H3K9 modifications in a coordinated way.

A phase II trial of ZD6474 in patients with hereditary metastatic medullary thyroid cancer

5533

Background: Medullary thyroid carcinoma (MTC) is the most common cause of death in patients with hereditary syndromes caused by specific mutations in the RET protooncogene. RET activation is the oncogenic event, which results in intrinsic RET receptor tyrosine kinase activity, but other pathways, such as VEGFR- and EGFR-dependent signaling, also participate in tumor growth and development. ZD6474 is a once-daily oral agent that selectively targets RET, VEGFR and EGFR tyrosine kinases. The clinical activity of ZD6474 was evaluated in patients with hereditary MTC. Methods: In this open-label Phase II study, patients with unresectable, measurable, locally advanced or metastatic hereditary MTC and a RET germline mutation received once-daily oral doses of ZD6474 300 mg. The primary objective was to assess the objective tumor response (RECIST). Secondary objectives included assessments of biochemical response (determined by changes in plasma levels of calcitonin [CTN]) and safety/tolerability of ZD6474. An exploratory objective was to measure plasma levels of carcinoembryonic antigen (CEA). Results: As of 30 November 2005, 16 patients (6 male/10 female; median age 50 years, range 22–77) had entered the study and received initial treatment with ZD6474 300mg. The median duration of treatment was 136 days (range 16–353). Fifteen patients were evaluable for tumor response, CTN, and CEA. Objective tumor assessments have demonstrated partial responses in 3 patients (n = 2 confirmed; n = 1 unconfirmed), stable disease in 10 patients (n = 8, ≥8 and <24 weeks; n = 2, ≥24 weeks) and progressive disease in 2 patients. A >50% decrease from baseline in plasma CTN levels has been maintained for at least 4 weeks in 12/15 patients; a decrease in plasma CEA levels of the same magnitude and duration has been observed in 6/15 patients. Common adverse events (AEs) were diarrhea (n = 12) and nausea, rash and fatigue (each n = 11). CTC grade 3 AEs attributable to ZD6474 were QTc interval prolongation (n = 3), and diarrhea, skin rash and hypertension (each n = 2). Conclusions: ZD6474 shows promising evidence of clinical activity in patients with hereditary MTC. These are preliminary data and patients are still being recruited to this ongoing study.

[Table: see text]

A phase II trial of ZD6474 plus docetaxel in patients with previously treated NSCLC: Follow-up results

7016

Background: ZD6474, a once-daily oral agent, targets key signaling pathways in cancer by inhibiting VEGF, EGF and RET receptor tyrosine kinases. ZD6474 in combination with docetaxel (Doc) was assessed in patients (pts) with refractory non-small-cell lung cancer (NSCLC). Methods: Pts eligible for this randomized, double-blind study had locally advanced or metastatic (stage IIIB/IV) NSCLC after failure of 1st-line platinum-based chemotherapy. The primary objective was to determine whether once-daily oral ZD6474 (100 or 300 mg) + Doc (75 mg/m2 i.v. infusion every 21 days) prolonged progression-free survival (PFS) vs Doc alone (80% power to detect 50% prolongation at P<0.2). Overall survival was a secondary objective. Results: A total of 127 pts (73 male/54 female; median age 59 yrs, range 29–82) received ZD6474 100 mg + Doc (n=42), ZD6474 300 mg + Doc (n=44) or Doc (n=41). The study met its primary objective of PFS prolongation with the addition of ZD6474: median PFS was 19 wks for ZD6474 100 mg + Doc (HR=0.64; P=0.074); 17 wks for ZD6474 300 mg + Doc (HR=0.83; P=0.461); and 12 wks for Doc. A total of 64 pts (50%) presented with histology other than adenocarcinoma, including 37 with squamous, and 13 pts (10%) entered with CNS metastases. Exploratory subgroup analyses suggest advantages in PFS for ZD6474 + Doc vs Doc both for adenocarcinoma and for other lung cancer histologies. Common adverse events (AEs) included diarrhea, rash and asymptomatic QTc prolongation, all responded to standard management or dose interruption/reduction. Four pts with squamous experienced hemoptysis (ZD6474 100 mg + Doc, n=2 CTC grade 1/2; Doc, n=2 CTC grade 3/4). No fatal episodes of hemoptysis or any CNS hemorrhage AEs were reported in pts receiving ZD6474. Overall survival data were immature at the time of PFS analysis, and a mature survival analysis will be conducted at ∼75% of deaths (anticipated April 2006, and will be presented at the meeting). As of December 2005, 40/127 (31%) pts were alive, 5 of whom continue to receive ZD6474. The minimum follow-up of pts still alive was 17 months. Conclusions: ZD6474 + Doc prolonged PFS vs Doc alone, and these promising data have led to the initiation of Phase III evaluation of ZD6474 + Doc in 2nd-line NSCLC.

[Table: see text]

Geographic distribution, virologic and clinical characteristics of hepatitis B virus genotypes in China

The significance of hepatitis B virus (HBV) genotypes for the heterogeneity of chronic HBV infection and severity of liver disease is not well understood. The aim of this study was to determine the distribution and virologic characteristics of HBV genotypes in China and possible association with the diversity of liver disease. The study includes 1096 chronic HBV carriers from nine provinces in China. We collected clinical and laboratory data and analysed the HBV strains in sera by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and nucleotide sequencing techniques. The most common HBV genotypes were B (41%) and C (53%), while genotypes A and D were also found. A North-South divide was identified in genotype B and C distribution - genotype C was predominant in northern China, while genotype B was more prevalent in southern provinces. Patients with genotype B were younger than those with genotype C, and had a lower prevalence of HBeAg - 65%vs 72%, respectively (P = 0.03). However, the severity of liver disease did not differ significantly between patients infected with genotype B or C - neither when comparing liver function tests (1024 patients), nor hepatic inflammation and fibrosis (264 patients). Amongst 47 patients with genotype D (by PCR-RFLP), 37 (79%) were infected with a new subtype (designated Dc), having a recombination fragment from genotype C precore/core region. This is the first large-scale HBV genotype study from China and convincing documentation of the North-to-South gradient of genotypes C vs B in this country. HBV DNA recombination over the surface and precore/core genes increases the diversity of HBV strains and may have diagnostic and clinical implications.

Resonance contributions to anti-Stokes/Stokes ratios under surface enhanced Raman scattering conditions

Anti-Stokes/Stokes asymmetries under surface enhanced Raman scattering (SERS) conditions are studied for a wide variety of SERS-active media and different analytes. Evidence is provided for the existence of underlying resonances that create these asymmetries. We show here that these resonances are associated with the electromagnetic coupling between the analyte (probe) and the metal. The work demonstrates the use of the anti-Stokes/Stokes ratio as a tool to understand the hierarchy of resonances in the SERS problem, which is essential for quantification purposes.

Hot-spot mutations in hepatitis B virus core gene: eliciting or evading immune clearance?

The biological implications of substitutions L60V and I97L in the core (c) gene of hepatitis B virus (HBV) were investigated in order to determine whether they could change the immunogenicity of HBcAg or influence the immune response in mice. Three strains of recombinant adenoviruses--AdHBV-WT, AdHBV-L60V and AdHBV-I97L--containing wild-type or mutant HBV genomes were constructed using the AdEasy system and used to infect BALB/c mice intranasally. Infected mice produced anti-HBc efficiently to comparable levels. IgG1 and IgG2a specific for HBcAg were present in mice sera, and the response was dominated by IgG2a. The lymphocyte proliferative response specific for HBcAg was assessed by [3H]-thymidine uptake. We found that AdHBV-WT induced a stronger T-cell proliferation response than AdHBV-L60V and AdHBV-I97L. In conclusion, the L60V and I97L substitutions had no influence on humoral immune responses, but could downregulate T-cell responses to HBcAg, suggesting that L60V and I97L were immune escape mutants.

DNA methylation patterns in in vitro-fertilised goat zygotes

Recent studies have shown that zygote demethylation patterns in mammals are variable among species. However, the methylation patterns of goat zygotes have not yet been reported on. In the present study, using immunofluorescence staining with an antibody against 5-methylcytosine, the methylation patterns of in vitro-derived goat zygotes were studied. The results indicate that goat zygotes do not undergo active global demethylation during pronuclei development, which is similar to the situation in ovine, but not in murine or bovine zygotes. This is believed to be the first report regarding methylation in goat zygotes.

Expression and characterization of a serine protease that preferentially cleaves insulin-like growth factor binding protein-5

Insulin-like growth factor binding proteins (IGFBPs) play important roles in regulating the functions of insulin-like growth factors (IGFs). Because IGFBPs have very high affinity for IGF-I and IGF-II, they can regulate the amount of each growth factor that is able to bind to cell surface receptors, therefore, factors that alter IGFBP affinity have the capacity to regulate IGF actions. Protease activities that are present in cell culture systems and physiologic fluids have been shown to degrade IGFBP-5. Previously, a region of sequence in a serine protease was identified that was homologous with the N-terminal 90 amino acids of members of the IGFBP family and with members of the CCN family of proteins. In a prior study, the protease was expressed in human kidney cultured cells and the cell culture supernatants were shown to cleave IGFBP-5, however, it is unknown whether the purified protease would cleave IGFBP-5 and whether it would also cleave other specific forms of IGFBPs. In this study, we expressed this protease in an insect cell expression system, purified it to homogeneity and tested its capacity to cleave IGFBP-5. The expressed protease preferentially cleaved IGFBP-5, and it had minimal activity toward other forms of IGFBPs. The proteolytic activity of this IGFBPase is inhibited by serine protease inhibitors including PMSF and 3,4-dichloroisocoumarin, as well as by divalent metal ions such as, Zn and Cu. Mutation of the active site serine resulted in a major reduction in IGFBP-5 cleavage. The protease binds to heparin and its ability to degrade IGFBP-5 is blocked in the presence of heparin. Inhibition of the activity of the protease following its secretion by B104 cells resulted in inhibition of IGFBP-5 proteolysis and IGF-I stimulation of protein synthesis. Northern blotting revealed that the transcript was expressed in multiple human tissues, including placenta, uterus, prostate, testis, spinal cord, brain, liver, small intestine, thyroid, and spleen. The highest expression was in uterus and placenta, suggesting a possible role of sex steroids in regulating its expression. Understanding the mechanism of how cleavage of IGFBP-5 by this protease alters its activity will help to further our understanding of the biologic actions of the IGFs.

Surgical treatment for cancer of the oesophagus and gastric cardia in Hebei, China

BACKGROUND

Southern Hebei Province has one of the highest incidences of oesophageal cancer in the world. This study describes a single-centre experience with oesophagectomy for this condition.

METHODS

The reported articles on surgical treatment for cancer of the oesophagus and gastric cardia from a single department between September 1952 and December 2000 were summarized and the results compared.

RESULTS

Between September 1952 and December 2000, the resectability rate increased from 78.8 to 96.0 per cent for oesophageal cancer and from 69.6 to 94.8 per cent for cancer of the cardia. The surgical mortality rate decreased from 4.6 to 1.1 per cent. There was little change in the overall 5-year survival rate; it increased from 21.2 to 23.9 per cent for patients with oesophageal cancer and from 15.2 to 17.6 per cent for those with cancer of the cardia.

CONCLUSION

The rate of postoperative complications and deaths following oesophagectomy for cancer has fallen steadily over the past five decades but long-term survival remains disappointing. Improved survival is likely to be dependent on earlier diagnosis and adjunctive therapies.

Transgenic twin lambs cloned by granulosa cells

The development potential of transgenic adult cells after nuclear transfer (NT) was evaluated. Primary ovine granulosa cells (GC(S)) from a slaughter ovary were transfected with pEGFP-N1 plasmid DNA. Three G418-resistance cell lines (A2, B2 and B4) were used as donor cells in NT. A total of 162 NT blastocysts were then frozen with ethylene glycol solution and stored for five months before transplanted into recipients. Twenty-nine frozen thawed NT blastocysts were transferred into 15 synchronized recipients. Twin lambs (6.9%) derived from B2 line were delivered by cesarean section on day 143 but died after birth. A tumor consisting of lung tissues was found on the surface of left lung of the 4-kg lamb and histological analysis indicated that it resembles a hamartoma. DNA analysis confirmed that two lambs were genetically identical to B2 donor cells. Gene insertion and expression have been detected in fibroblasts cells derived from muscle tissues of the lambs. This study indicates that granulosa cell is a suitable cell type for producing transgenic animals by nuclear transfer. Offspring were produced after long-term storage of NT blastocysts.

A gene therapy for cancer based on the angiogenesis inhibitor, vasostatin

The growth and persistence of solid tumors and their metastasis are angiogenesis-dependent. Vasostatin, the N-terminal domain of calreticulin inclusive of amino acids 1-180, is a potent angiogenesis inhibitor. To investigate whether intramuscular administration of vasostatin gene has the antitumor activity in mouse tumor models, we constructed a plasmid DNA encoding vasostatin and a control vector. Production and secretion of vasostatin protein by COS cells transfected with the plasmid DNA encoding vasostatin (pSecTag2B-vaso) were confirmed by Western blot analysis and ELISA. Conditioned medium from vasostatin-transfected COS cells apparently inhibited human umbilical vein endothelial cell (HUVEC) and mouse endothelial cell (SVEC4-10) proliferation, compared with conditioned medium from the COS cells transfected with control vector or non-transfected cells. Treatment with pSecTag2B-vaso twice weekly for 4 weeks resulted in the inhibition of tumor growth and the prolongation of the survival of tumor-bearing mice. The sustained high level of vasostatin protein in serum could be identified in ELISA. Angiogenesis was apparently inhibited in tumor by immunohistochemical analysis. Angiogenesis was also inhibited in the chicken embryo CAM assay and mouse corneal micropocket assay. The increased apoptotic cells were found within the tumor tissues from the mice treated with plasmid DNA encoding vasostatin. Taken together, the data in the present study indicate that the cancer gene therapy by the intramuscular delivery of plasmid DNA encoding vasostatin, is effective in the inhibition of the systemic angiogenesis and tumor growth in murine models. The present findings also provide further evidence of the anti-tumor effects of the vasostatin, and may be of importance for the further exploration of the application of this molecule in the treatment of cancer.

[Immunohistochemical study on ANP in the atria of electrocution]

By the immunohistochemical staining for ANP with LSAB method and the analysis of areas and grays of ANP with computer image analysis, it was found that the ANP granulus in right atria of electrocution were obviously depleted, compared with that in the control groups. The results showed that depletion of ANP granules in right atria could be used as a reference for the forensic diagnosis of electrocution and might benefit for the clinical therapy to the patients suffering from electric injuries.

Thymosin-alpha1 and famciclovir combination therapy activates T-cell response in patients with chronic hepatitis B virus infection in immune-tolerant phase

We examined whether combination therapy with thymosin-alpha1 and famciclovir would induce hepatitis B e antigen seroconversion in patients with chronic hepatitis B infection in the immune-tolerant phase without inducing significant hepatic necro-inflammation. We studied 32 hepatitis B e antigen positive patients in the immune-tolerant phase of infection, treated with 26-weeks combination therapy of famciclovir and thymosin-alpha1 (group 1). Thirty-two patients who received 26-weeks famciclovir monotherapy (group 2) and another 32 patients who received no treatment (group 3), served as controls. Peripheral blood mononuclear cell proliferation and cytokine secretion in response to recombinant HBV core and surface antigen and serial serum HBV-DNA, were assayed. No significant difference in adverse events were observed among the three groups. By week 26, the median reduction in group 1 (0.94 log10 copies/mL) was greater than group 2 (0.70 log10 copies/mL, P < 0.001). Five (15.6%) patients in group 1 at 52 weeks (median range 13-78 weeks) and none in group 2 or 3 experienced hepatitis B e antigen seroconversion (P = 0.053). Sustained serological clearance of hepatitis B e antigen was associated with activation of CD4 positive HBV-specific T-cell reactivity and were of T-helper 1. Hence combination therapy with immunomodulatory agents and nucleoside analogues should be explored.

Prevalence of naturally occurring surface gene variants of hepatitis B virus in nonimmunized surface antigen-negative Chinese carriers

Previous studies have suggested that hepatitis B virus (HBV) variants may account for the presence of HBV DNA in hepatitis B surface antigen (HBsAg)-negative patients (occult HBV infection). However, it is not known how widespread these variants are and how they influence the course of liver disease. To determine the prevalence of variants within the major hydrophilic region (MHR) of HBsAg, we investigated 2,565 subjects, including subjects with chronic hepatitis, cryptogenic cirrhosis, hemodialysis patients, and blood donors. Fifty-one of them had occult HBV infection. The entire S gene from 46 of these patients was sequenced from amplified serum HBV DNA. Forty-three percent (20 of 46) had mutations in the MHR of HBsAg. Thirty-two amino acid substitutions between positions 100-160 of the MHR of HBsAg were detected in 18 patients, and these ranged from 1 to 4 per patient. These changes involved 11 positions inside and 5 outside of the historical first and second loops of the "a" determinant, and included the following: Q101K, T115A, K122N, T123A, T126N, Q129N, G130R, T131I, M133T, F134L, C138Y, K141E, P142S, G145R, N146S, and C147F/R. Combinations of mutations were detected in 9 patients, and 7 of these have not been described before. Two further patients had insertion mutations immediately before the "a" determinant. Monoclonal antibody binding tests with the Royal Free hepatitis B surface (RFHBs) panel of antibodies revealed decreased immunoreactivity in 6 novel variants of HBsAg. The existence of patients with occult HBV infection caused by HBsAg variants, therefore, has implications for their possible transmission through sexual contact and by blood transfusion.

[Study on structure change and hypermethylation of p16 gene in multiple myeloma]

OBJECTIVE

To illustrate the role of structure and hypermethylation of p16 gene in the pathogenesis of multiple myeloma(MM).

METHODS

By using PCR-single strand conformation polymorphisms(PCR-SSCP) and methylation-specific PCR(MSP) techniques, the structure and hypermethylation status of p16 gene in MM cell lines and patients were analysed.

RESULTS

Homozygous deletion of p16 exon 2 was found in KM3 cells. The completely methylated p16 gene and hypermethylation of CPG island were observed in U266, LP1 cell lines and 55.56% of MM patients.

CONCLUSION

Methylation of p16 gene is important in the pathogenesis of MM and may provide a new drug target for the treatment of MM.

[Influences of rearing style on the intellectual development of infants]

The factors causing the imbalance on intellectual development of infants in the early period after birth were studied and some better styles of rearing infants were found. The developmental quotient in 68 infants of 3-months-old was tested with Gesell Developmental Schedules and the style for rearing infants was obtained by inquiring their parents. The results showed that: (1) the development of adaptive behavior, language and personal--social behavior was better than that of gross motor and fine motor; (2) giving infants opportunity to move could make the development of adaptive behavior, gross motor and fine motor better. The development of fine motor could be hampered if a pair of mitten was put on hands to avoid scratching infant own face. Out doors activities were more important on the development of adaptive behavior, gross motor, fine motor and personal--social behavior; (3) in addition to the mother, with the cooperation of grandparents or father to look after infants was better. The higher education level of parents always associated with a better mental development of infants; (4) the complex structure with more people in a family make the development of language better. It is suggested that if parents have more knowledge on caring infants, give infants more opportunity to move and communicate with other people, it would be beneficial to the development of infants.

[A preliminary study on translocation of the immunoglobulin heavy chain gene in KM3 myeloma cell line]

OBJECTIVE

To identify the IgH translocation in KM3 myeloma cell line established from a Chinese patients.

METHODS

Southern blotting was performed with dig-labeled probes specific for IgH switch regions to identify and distinguish IgH switch recombination events.

RESULTS

Besides a 10.0 kb Hind III fragment being able to hybridize with both 5' S mu and 3' S mu probes as that in placenta genome DNA. There was a 5.6 kb Hind III fragment in KM3 genome DNA could only hybridize with the 3' S mu probe.

CONCLUSION

There was an illegitimate switch recombination fragment containing 3' S mu region in the KM3 myeloma cell line, which was caused by the IgH translocation involving the IgH S mu region.

Novel HLA-B alleles identified in potential marrow donors: B*3917, B*1405 and B*3528

Sequence-specific oligonucleotide probe hybridization and sequence-specific primer polymerase chain reaction (PCR) typing of volunteer bone marrow donors suggested the presence of variants of known HLA-B alleles in five individuals. PCR products encompassing HLA-B locus exons 1 through 3 were prepared and subcloned. Three African-American individuals had a novel HLA-B*39 allele (B*3917), and another African-American was found to have a novel HLA-B*14 allele (B*1405). In a third individual of Hispanic origin, a novel HLA-B*35 allele (B*3528) was identified. These findings further illustrate the substantial genetic variation present at the HLA-B locus within human populations.

[Purification feasibility of malodorous waste gas contained H2S and CS2 by DBD technique]

Dielectric barrier discharge(DBD) technique was applied to remove H2S and CS2 in industrial waste gas. In the research of laboratory, when the voltage between two electrodes was 12 kV, 4 x 10(3) Pa H2S was discharged in air for 5 seconds, about 100% of H2S was transformed into H2O and SO2; 1.33 x 10(3) Pa CS2 was discharged in air for 15 seconds, about 80% of CS2 was transformed into CO2, CO and SO2. When the concentration of H2S and CS2 increased, the decomposition of them decreased. Based on the results, a DBD purification apparatus which can dispose 420 m3/h, 10 m/s waste gas was designed and manufactured, the removal rate of H2S can reach 89% and the energy consumption was 5.2 W.h/m3. It was concluded that the DBD technique is worth disposing malodorous industrial waste gases contained H2S and CS2.

Th1/Th2 type cytokines in hepatitis B patients treated with interferon-alpha

OBJECTIVE

To investigate the relationship between the expression of Th1/Th2 type cytokines and the effect of interferon-alpha therapy.

METHODS

Th1/Th2 type cytokines were assayed by enzyme-linked immunosorbent assay (ELISA) and reverse transcription polymerase chain reaction (RT-PCR) on 23 patients with chronic hepatitis B who were treated with interferon-alpha.

RESULTS

Levels of IFN-gamma in the supernatant of peripheral blood mononuclear cells (PBMC) cultures from the patients with hepatitis B were slightly lower than those of controls (P = 0.07). However, the levels of IL-4 were higher than those of controls (P = 0.01). Cytokines measurements during IFN-alpha treatment showed a trend to decreasing levels of IL-4 at 4, 12, and 24 weeks. Levels of IFN-gamma were slightly increased following IFN-alpha treatment (P = 0.09). In patients with a complete response to IFN-alpha, the levels of IFN-gamma were higher at 24 weeks following IFN-alpha treatment than that of pre-treatment (P = 0.04), and the levels of IL-4 decreased markedly at 12 and 24 weeks (P = 0.02, 0.03, respectively). mRNA expression positively correlated with the level of Th1/Th2 type cytokines in the supernatant.

CONCLUSION

The expression of Th2 type cytokines is predominant in patients with chronic hepatitis B. Interferon-alpha therapy can modulate the balance of Th1/Th2 type cytokines, and this is related to its clinical effect. Levels of Th1/Th2 type cytokines could be a predictor of clinical response during Interferon-alpha treatment.

Neural correlates of response inhibition for behavioral regulation in humans assessed by functional magnetic resonance imaging

To identify the specific frontal and cingulate regions involved in response inhibition, five Chinese right-handed male volunteers with an attention span reaching or exceeding a 7-digit level participated in this blocked design functional magnetic resonance imaging study. Each block represented one of the two experimental conditions, the Correct Matching or the Incorrect Matching condition. In the Correct Matching condition, the subjects were required to make correct judgement of whether the two 3-digit numbers presented in succession were the same or not; whereas in the Incorrect Matching condition, the participants were instructed to inhibit the correct responses. Bilateral activations of the prefrontal and anterior cingulate as well as the left posterior cingulated cortex were observed while the subjects were exercising response inhibition. The roles of these activations in response inhibition were discussed.

Cold adaptive thermogenesis in small mammals from different geographical zones of China

The mechanisms of thermogenesis and thermoregulation were studied in the tree shrew (Tupaia belangeri) and greater vole (Eothenomys miletus) of the subtropical region, and Brandt's vole (Microtus brandti), Mongolian gerbil (Meriones unguiculatus), Daurian ground squirrel (Spermophilus dauricus) and plateau pika (Ochotona curzoniae) of the northern temperate zone. Resting metabolic rate (RMR) and non-shivering thermogenesis (NST) increased significantly in T. belangeri, E. miletus, M. brandti and M. unguiculatus after cold acclimation (4 degrees C) for 4 weeks. In T. belangeri, the increase in RMR and thermogenesis at liver cellular level were responsible for enhancing the capacity of enduring cold stress, and homeothermia was simultaneously extended. Stable body temperature in M. brandti, E. miletus, M. unguiculatus and O. curzoniae was maintained mainly through increase in NST, brown adipose tissue (BAT) mass and its mitochondrial protein content, and the upregulation of uncoupling protein (UCP1) mRNA, as well as enhancement of the activity of cytochrome C oxidase, alpha-glycerophosphate oxidase and T(4) 5'-deiodinase in BAT mitochondria. The RMR in O. curzoniae and euthermic S. dauricus was not changed, while NST significantly increased during cold exposure; the former maintained their stable body temperature and mass, while body temperature in the latter declined by 4.8 degrees C. The serum T(3) concentration or ratio of T(3)/T(4) in all the species was enhanced after cold acclimation. Results indicated that: (1) the adaptive mechanisms of T. belangeri residing in the subtropical region to cold are primarily by increasing RMR and secondly by increasing NST, and the mechanisms of thermogenesis are similar to those in tropical mammals; (2) in small mammals residing in northern regions, the adaptation to cold is chiefly to increase NST; (3) the mechanism of cold-induced thermogenesis in E. miletus residing in subtropical and high mountain regions is similar to that in the north; (4) a low RMR in warm environments and peak RMR and NST in cold environments enabled M. unguiculatus to tolerate a semi-desert climate; (5) O. curzoniae has unusually high RMR and high NST, acting mainly via increasing NST to adapt to extreme cold of the Qinghai-Tibet Plateau; (6) the adaptation of euthermic S. dauricus to cold is due to an increase in NST and a relaxed homeothermia; and lastly (7) the thyroid hormone is involved in the regulation of cold adaptive thermogenesis in all the species studied.

Concordant p53 and mdm-2 protein expression in vulvar squamous cell carcinoma and adjacent lichen sclerosus

To determine if carcinogenic events in vulvar skin precede the onset of morphologic atypia, the authors investigated for derangements in DNA content, cell proliferation, and cell death in vulvar carcinomas and surrounding skin in 140 samples of tumor and surrounding skin collected from 35 consecutive vulvectomy specimen for squamous cell carcinoma (SCC) or vulvar intraepithelial neoplasia (VIN) 3. Vulvar non-cancer excisions were used as controls. Investigations consisted of histologic classification and measurement of 9 variables--epidermal thickness (acanthosis and rete ridge length), immunolabeling index (LI) for 3 proteins (p53 protein, Ki-67, and mdm-2), pattern of p53 expression (dispersed vs. compact), DNA content index, and presence of aneuploidy by image analysis and apoptotic rate by Apotag labeling. Significant positive correlations were found for all nine variables studied versus increasing histologic severity in two proposed histologic stepwise models of vulvar carcinogenesis (lichen sclerosus (LS) and VIN 3 undifferentiated associated SCC groups). High p53 LI (>25) and the compact pattern of p53 expression (suspected oncoprotein) significantly correlated with LS and its associated vulvar samples compared with samples not associated with LS (P < or = 0.001). Furthermore, p53 LI, mdm-2 LI, and pattern of p53 expression were concordant between patient matched samples of LS and SCC. In addition, mdm-2 LI significantly correlated with dispersed pattern p53 LI suggesting a response to wild-type p53 protein accumulation. These findings support the hypothesis that neoplastic transformation occurs in sequential steps and compromises proteins involved in the cell cycle control. Concordance of p53 and mdm-2 protein expression in LS and adjacent SCC provides evidence that LS can act as a precursor lesion in the absence of morphologic atypia. Overexpression of mdm-2 with stabilization and inactivation of p53 protein may provide an alternate pathway for vulvar carcinogenesis.

[Simultaneous determination of trace cadmium and arsenic in grains using atomic absorption spectrophotometry]

Simultaneous determination of two components in single wavelength using interferencing effect and atomic absorption spectrophotometry assisted by simulated annealing-back propagation of error-artificial neural networks algorithm was realized, and simultaneous determination of trace cadmium and arsenic in grains was studied. The results obtained are satisfactory. The recoveries found by standard addition method are 91%-98% and 87%-92% respectively. Relative standard deviations for 7 times of determinations are all less than 4%. This method is fast and simple.

[Genotype polymorphism and its implications of mannose-binding protein allele in 5 Chinese nationalities]

OBJECTIVE

To detect the genotypes and sequences of the exon 1 of human mannose-binding protein (MBP) allele in 5 Chinese nationalities.

METHODS

The genotypes of MBP gene of 5 Chinese nationalities were detected by polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP). The exon 1 of the MBP gene of 22 Chinese Hans was analyzed by using ABI 310 genetic analyzer.

RESULTS

The DNA sequences of exon 1 of Chinese MBP gene were acquired. The allele frequencies of the codon 54 of the MBP gene (MBP-54) of 5 Chinese nationalities were 0.181(Hans), 0.128(Uygurs), 0.181(Mongols), 0.179(Tibetans) and 0.181(Yis). The allele distribution for MBP-54 mutation of 5 Chinese nationalities was in good agreement with Hardy-Weinberg equilibrium. Compared with the Hans, Uygurs had a lower MBP-54 mutation rate. There were no differences in the allele frequencies between the chronic hepatitis B patients and health controls in Chinese Hans. The mutations of the codons 52 and 57 were not detected in this study.

CONCLUSION

A higher prevalence of MBP-54 mutation was found in 5 Chinese nationalities, MBP-54 mutation was not associated with the persistence of hepatitis B.

[High expression of rabbit sperm membrane protein rSP10 in Escherichia coli and preparation of its specific antisera]

To study the position and immunogenicity of rSP10, the rabbit rsp10 gene which did not include sequences coding for signal peptides was inserted into expression vector pET30a. An in-frame fusion protein was made such that a His6 stretch was produced at the N terminus of re-rSP10. High expression was obtained, the amount of re-rSP10 up to 67% in the total bacterial protein. The re-rSP10 was purified by DEAE chromatography and the yield of purified re-rSP10 was approximately 50 micrograms/mL of culture. Western blotting analysis of re-rSP10 with rabbit polyclonal sera raised against rabbit sperm membrane protein showed that the synthesized antigen possessed immunogenicity of rSP10. Specific antisera against re-rSP10 was induced using purified re-rSP10 as an antigen. The motility of capacitated sperms were affected but no aggregation was observed.

Effect of smoking on serum concentrations of total homocysteine and B vitamins in mid-pregnancy

There are conflicting findings in the literature on the effect of smoking on total homocysteine (tHcy) concentrations in non-pregnant subjects. We evaluated the effect of smoking on serum concentrations of tHcy, folate, vitamin B-12 pyridoxal 5'-phosphate (PLP, a coenzyme form of vitamin B-6) in 196 women at 18 and 30 weeks' gestation. The smokers were defined as those who self-reported cigarette smoking and had serum concentrations of thiocyanate, a biomaker of smoking, in the highest quartiles of the population. Mid-pregnancy serum tHcy concentrations were not significantly different between smokers and non-smokers. Folate, vitamin B-12 and PLP concentrations were generally lower in smokers than non-smokers. In smokers, tHcy concentrations had significant negative correlations with folate at both time points. The multiple regression analyses indicated that serum folate concentration was the most significant factor associated with tHcy concentrations among smokers, whereas thiocyanate concentrations showed no such effect. We conclude that serum tHcy concentrations were most strongly associated with the nutritional status of folate among the B vitamins tested during mid-pregnancy in our subjects. We suggest that it is essential to consider the nutritional status of folate, vitamin B-12 and vitamin B-6 in evaluating the effect of smoking on homocysteine metabolism.

Perfusion-weighted imaging of interictal hypoperfusion in temporal lobe epilepsy using FAIR-HASTE: comparison with H(2)(15)O PET measurements

To detect perfusion abnormalities in areas of high magnetic susceptibility in the brain, an arterial spin-labeling MRI technique utilizing flow-sensitive alternating inversion recovery (FAIR) and half-Fourier single shot turbo spin-echo (HASTE) for spin preparation and image acquisition, respectively, was developed. It was initially tested in a functional study involving visual stimulation, and was able to detect significant activation with an increase (approximately 70%) in relative cerebral blood flow. Subsequently, it was applied in a clinical situation in eight patients with temporal lobe epilepsy (TLE). The perfusion-weighted images obtained showed no susceptibility artifacts even in the region of the inferior temporal lobe and were able to detect interictal hypoperfusion in TLE. The results were compared with those derived from H(2)(15)O PET perfusion imaging in each patient. A statistically significant correlation (r = 0.75, P < 0.05) was found between results acquired from these two modalities. Magn Reson Med 45:431-435, 2001.

[Exploration of high expressions of retroviral vectors containing hFIX minigene in murine myoblast cells]

OBJECTIVE

To explore the effect of different vector structure on hF IX protein expression in murine myoblasts in order to construct more efficient expression vector for my oblast-mediated gene therapy for hemophilia B.

METHODS

Three types of retroviral vectors pLMe2 IX m(2)SN (forward Me2: Me2 inserted into enhancer region of 3'LTR in forward orientation), pLMe2 IX m(2)SN (reversed Me2) and pL IX m(2)SN which contained intron m(2) and two copies of MCK enhancer (Me2) were transferred into packaging cell line PA317. The hFIX expression level in selected single and mixed clones of stably transfected myoblasts were determined by ELISA and PCR.

RESULTS

There was statistically significant difference in hFIX expression levels among the four vectors tested. The expression order was LMe2 IX m(2)SN (forward) > LMe2 IX m(2)SN (reversed) > L IXm(2)SN > L IX SN. The hF IX expression level of forward Me2 vector was higher than that of reversed one, because of one or two copies of reversed Me in the 5'LTR being deleted in the genome of myoblasts, but the orientation of Me or Me2 remained unchanged.

CONCLUSIONS

To select a tissue-specific enhancer and optimize FIX minigene construction are effective methods for increasing the expression level. Forward Me2 vector can express hFIX more stably than the reversed one.

[Antigen sandwiched ELISA for detection of total HIV antibodies]

OBJECTIVE

To establish a sensitive antigen sandwiched ELISA(AS) for detection of the total antibodies to HIV-1/2.

METHODS

Based on the gene sequence of HIV-1/2 type and its coded amino acid structure, 5 polypeptides were synthesized as coated antigens using solid-phase method. These polypeptides were labelled with horseradish peroxidase. And the total antibodies of HIV-1/2 were detected with the same method.

RESULTS

These reagents were detected by three batches of HIV panel from The National Institute for the Control of Pharmaceutical and Biological Products (NICPBP). The results indicated that the corresponding rate was 100%. The variant coefficient rate was less than 10%. A comparison of antigen sandwiched ELISA with indirect ELISA in detection of a panel(20 positive sera and 20 negative sera) from the NICPBP showed that the general coincident rate of indirect ELISA was 92.5% and the sandwiched system was 100%. The HIV-AS diagnostic reagent kits have passed the quality examination of NICPBP. A comparison of antigen sandwiched ELISA with Yapei reagents in detection of 90 normal sera and 88 positive sera for HIV-1/2 showed that the coincident rate was 100%. The reagents were stable at 37 degrees C for 4 days. This indicated that our reagents were highly specific, sensitive and stable.

CONCLUSION

Our antigen sandwiched ELISA reagent for total antibodies of HIV has a merit of sensitivity specificity and stability. It can be clinically used for detection of HIV-1/2 infection and in blood bank for the screening of blood donors.