BORRELIA BURGDORFERI DNA IN BIOLOGICAL SAMPLES FROM PATIENTS WITH SARCOIDOSIS USING THE POLYMERASE CHAIN REACTION TECHNIQUE

Polymerase chain reaction (PCR) was used to detect the presence of Barrelia burgdoferi DNA in biological samples from patients with sarcoidosis. The target DNA sequence was of chromosomal origin. The amplified DNA sequence was analyzed by agarose gel electrophoresis, PAGE with silver staining, and the identity of amplified DNA was confirmed by restriction enzyme cleavage and DNA-DNA hybridization with a 32P-labelled probe. The assay was sensitive to fewer than two copies of B. burgdorferi genome, even in the presence of a 104-fold excess of human eukaryotic DNA , and was also specific to different B. burgdorferi strains tested. Sera serologically positive to B. burgdcrferi (n=26), bronchoalveolar lavage fluid and supernatant of BALF (n=26) and peripheral blood (n=9) from sarcoidosis patients were tested. The positive rate was low (4/26, 2/26. and 0/9, respectively). It was considered that DNA from B. burgdor ferimay be identified in a minority of patients with sarcoidosis, and it may play a pathogenetic role in such cases. More studies need to be done before advancing the hypothesis of an etiologic role of B. burgdorferi in sarcoidosis.

A quantitative polymerase chain reaction assay for the enumeration of brown tide algae Aureococcus anophagefferens in coastal waters of Qinhuangdao

Aureococcus anophagefferens, a small pelagophyte algae, has caused brown tide blooms in coastal waters of Qinhuangdao in recent years, presenting significant negative impacts on the shellfish mariculture industry. Under standard light microscopy, it is visually indistinguishable from other small algae in field samples due to its extremely small size. In this study, quantitative polymerase chain reaction（q PCR） based on 18 S r DNA sequences was developed and used to detect and enumerate A. anophagefferens. A linear regression（R2 = 0.91） was generated based on cycle thresholds value（Ct） versus known concentrations of A. anophagefferens. Twenty-two field samples collected in coastal waters of Qinhuangdao were subjected to DNA extraction and then analyzed using q PCR. Results showed that A. anophagefferens had a wide distribution in coastal waters along Qinhuangdao. Elevated A. anophagefferens abundance, category 3 brown tide blooms（〉200 000 cells/m L） occurred at Dongshan Beach and Tiger-stone Beach in August in 2013. In shellfish mariculture areas along coastal waters of Qinhuangdao, 4 stations had category 3 blooms, and 6 stations had category 2 blooms（35 000–200 000 cells/m L） in August and all stations had category 1 blooms（〉0 to ≤35 000 cells/m L） in October. Quantitative PCR allows for detection of A. anophagefferens cells at low levels in filed samples, which is essential to effective management and prediction of brown tide blooms.

Primary application of a real-time quantitative polymerase chain reaction for the detection of human breast cancer related novel gene-Metadherin expression

Objective:The aim of this study was to detect the expression level of Metadherin (MTDH) in peripheral blood of the breast cancer patients by real-time fluorescence quantitative polymerase chain reaction (PCR),and to explore the relationship between expression of Metadherin gene in the patients peripheral blood and the clinic-pathological features in breast cancer. Methods:Real-time fluorescence quantitative polymerase chain reaction was employed to determine the expression level of Metadherin gene in 80 peripheral blood samples of breast cancer patients and healthy donors. Results:The expression of Metadherin gene in breast cancer patients peripheral blood were positive,in which 34 breast cancer patients were highly expressed,accounting for 55.7%,while the expression of Metadherin gene in normal females peripheral blood were negative,there was statistical significance (Ratio = 2.02±0.81,P < 0.05); Ratio of the Metadherin expression in breast cancer patients peripheral blood and the glyceraldehyde-3-phosphate dehydrogenase expression was 1.15 ± 0.36. REST software analysis showed that the expression of Metadherin gene was significantly up-regulated in breast cancer. Conclusion:The SYBR Green I quantitative real-time polymerase chain reaction method can successfully detect the expression level of Metadherin gene. Expression level of Metadherin gene in breast cancer patients peripheral blood is closely related to survival,and it maybe involved in the development of breast cancer and used as an indicator of prognosis.

Detection of Human Papillomavirus DNA in Oral Cancer Tissue Using Polymerase Chain Reaction

Using polymerase chain reaction (PCR), 25 specimens from 22 patients with oral carcinomas were examined by 6 selected primers of human papillomavirus (HPV). Eighteen of the 22 patients (18/22) gave positive reaction with a positive rate of 81.8%. The positive rates of HPV 6, 11, 16 and 18 were 27.3%, 18.2%, 63.6% and 40.9% respectively. 13.6% positive for mixed infection of HPV 16 and 18 (3/22) and 18.2% positive for mixed infection of HPV, 6, 11, 16 and 18 (4/22). Examining enlarged cervical lymph nodes in three cases with suspecting metastases to cervical lymph nodes from oral carcinomas. It revealed HPV DNA 16 and 18 in two cases and HPV DNA 18 in one case. These results suggested that there was a tendency for HPV 16 and 18 to metastasinze via lymphatics. Only one case of the three had a pathologic diagnosis of lymph node metastasis. Of the 30 non tumor controls, HPV DNA positivity was 10%, all being HPV 18. χ 2 test gave a P<0.005. It strongly indicated that HPV 16 and 18 were related to oral carcinomas.

Investigation on detection of Haemophilus ducreyi by Polymerase Chain Reaction

Objective:To investigate the application of polymerase chain reaction (PCR) detection of Haemophilus ducreyi in clinical diagnosis of chancroid. Methods: Nucleotide sequences of 16srRNA gene specific for H. dureyi were used to develop primer sets for amplification of two strains. The amplified products were tested via PCR and sequenced by electrophoresis in a 1.5% gel.These products were compared with those of heterogeneous species or related bacteria to test the specificity of the PCR assay. PCR amplification with different concentrations of H.ducreyi was performed to test its sensitivity. Results: PCR amplification of two strains of H. ducreyi produced a single band of expected 438bp length. The sequence was identified with genomic DNA. None of the other 19 reference species amplified under the same conditions gave this result. The highest sensitivity of PCR assay in the present test was 10ng/L. Conclusions: PCR assay for detection of H. ducreyi is a rapid, specific, and sensitive detection method. If laboratory conditions are strictly controlled, PCR assay is a potentially useful laboratory test for H. ducreyi infection diagnosis.

Sperm Mediated Transfer of Genes into Goldfish and Detection by Polymerase Chain Reaction

Goldfish sperms were mixed with eggs for fertilization after incubation with antifreeze protein gene(AFP)from ocean pout for 30 min.A number of embryos and 145 adult goldfish were obtained.DNA from adult goldfish and embryos was extracted separately.Results of the amplification by PCRand Southern blot molecular hybridization indicate the integration of exogenous antifreeze gene intothe genome of a part of the recipient goldfish.Of the 45 samples detected by PCR,twelve showedpositive reaction with distinct hybridization band.The positive rate was 26%.

Development and Clinical Application of a Single-tube Nested PCR Method to Amplify the DNA Polymerase Ⅰ Gene of Treponema Pallidum

Objective: To develop a sensitive, specific and simple method for detection of extremely low numbers of T. pallidum in clinical specimens, as a significant addition to the serologic tests for syphilis diagnosis. Methods: Double-tube nested PCR(DN-PCR) and single-tube nested PCR(SN-PCR) assays were performed to amplify specific fragments of the DNA poly-merase I gene(polA) of T. pallidum. Sensitivity and specificity of the two PCR assays were tested. Eighty-six whole blood specimens from persons with suspected syphilis were detected by the two nested PCR methods. The TPPA test was used as a comparison for detecting syphilis in sera from corresponding patients. Results: Only specific amplicons could be obtained during amplification of the T. pallidum polA gene and the detection limit was approximately 1 organism when analyzed on gel by the two PCR methods. Of 86 clinical specimens, 62 were positive by TPPA. Of these, 54 and 51 were positive by the DN-PCR and SN-PCR, respectively, which does not represent a statistically significant difference between the two PCR tests. Of 24 TPPA-negative specimens, 5 were positive by both DN-PCR assay and SN-PCR assay. Conclusion: The SN- polA PCR method is extremely sensitive, specific and easy to perform for detecting low numbers of T. pallidum in clinical blood specimens as a complementary to serology for syphilis diagnosis.

Bacterial Community Structure in a Mollisol Under Long-Term Natural Restoration, Cropping, and Bare Fallow History Estimated by PCR-DGGE

Soil microbial biomass and community structures are commonly used as indicators for soil quality and fertility. A investigation was performed to study the effects of long-term natural restoration, cropping, and bare fallow managements on the soil microbial biomass and bacterial community structures in depths of 0-10, 20 30, and 40-50 cm in a black soil （Mollisol）. Microbial biomass was estimated from chloroform fumigation-extraction, and bacterial community structures were determined by analysis of 16S rDNA using polymerase chain reaction-denaturing gradient gel electrophoresis （PCR- DGGE）. Experimental results showed that microbial biomass significantly declined with soil depth in the managements of restoration and cropping, but not in the bare fallow. DGGE profiles indicated that the band number in top 0-10 cm soils was less than that in depth of 20-30 or 40-50 cm. These suggested that the microbial population was high but the bacterial community structure was simple in the topsoil. Cluster and principle component analysis based on DGGE banding patterns showed that the bacterial community structure was affected by soil depth more primarily than by managements, and the succession of bacterial community as increase of soil depth has a similar tendency in the three managements. Fourteen predominating DGGE bands were excised and sequenced, in which 6 bands were identified as the taxa of Verrueomicrobia, 2 bands as Actinobacteria, 2 bands as α-Proteobacteria, and the other 4 bands as 8-Proteobacteria, Aeidobacteria, Nitrospira, and unclassified bacteria. In addition, the sequences of 11 DGGE bands were closely related to uncultured bacteria. Thus, the bacterial community structure in black soil was stable, and the predominating bacterial groups were uncultured.

Cloning, sequencing and analyzing of the heavy chain V region genes of human polyreactive antibodies

The heavy chain variable region genes of 5 human polyreactive mAbs generated in our laboratory have been cloned and sequenced using polymerase chain reaction (PCR) technique. We found that 2 and 3 mAbs utilized genes of the VHIV and VHIII families, respectively. The former 2 VH segments were in germline configuration. A common VH segment, with the best similarity of 90.1 % to the published VHIII germline genes, was utilized by 2 different rearranged genes encoding the V regions of other 3 mAbs. This strongly suggests that the common VH segment is a unmutated copy of an unidentified germline VHIII gene. All these polyreactive mAbs displayed a large NDN region (VH-D-JH junction). The entire H chain V regions of these polyreactive mAbs are unusually basic. The analysis of the charge properties of these mAbs as well as those of other poly- and mono- reactive mAbs from literatures prompts us to propose that the charged amino acids with a particular distribution along the H chain V region,especially the binding sites (CDRs), may be an important structural feature involved in antibody polyreactivity.

Characterization by PCR of Escherichia coli from Beef and Chicken Used in Restaurants in YaoundéCameroon

Meat constitutes the main source of protein and occupies an important place in our diet. Indeed, the production of poultry and beef has increased. However, the hygienic quality of meat is not always guaranteed. Microorganisms such as Escherichia coli can be found in meat and can cause various infections including diarrhea, dysentery, food poisoning, gastroenteritis or typhoid fever. Thus, the present study was designed to characterize Escherichia coli (E. coli) from beef and chicken consumed in restaurants in Yaoundé Cameroon. A total of 105 meat samples (60 beef and 45 chickens) were subjected to microbial culture for E. coli isolation and further confirmed by Polymerase Chain Reaction (PCR) using primers EC-F and EC-R that are specific to E. coli 16S rRNA gene. The supplier source, storage, and transport conditions were taken into consideration during sample analysis and data processing. This study revealed that 77/105 samples (73.33%) were positive for E. coli following microbial culture and 35 (33.33%) were positive for E. coli following molecular examination. A statistically significant difference was observed when PCR and microbial culture were used to assess for E. coli in beef and a non-statistically significant difference was observed in the case of chicken meat. Also, a statistically significant difference was noticed with the different transport conditions, but this wasn’t the case with the supplier source as well as the storage conditions where a non-statistically significant difference was seen. This study revealed that PCR-based methods are fast and reliable in the identification and characterization of Escherichia coli in meats (beef and chicken) as well as in assessing the prevalence of pathogenic E. coli, in Cameroon.

One-Pot Polymerase Chain Reaction with Gold Nanoparticles for Rapid and Ultrasensitive DNA Detection

We report a novel method for rapid,colorimetric detection of a specific deoxyribonucleic acid(DNA)sequence by carrying out a polymerase chain reaction in the presence of gold nanoparticles functionalized with two primers.Extension of the primers when the target DNA is present as a template during the polymerase chain reaction process affords the complementary sequences on the gold nanoparticle surfaces and results in the formation of gold nanoparticle aggregates with a concomitant color change from red to pinkish/purple.This method provides a convenient and straightforward solution for ultrasensitive DNA detection without any further post-treatment of the polymerase chain reaction products being necessary,and is a promising tool for rapid disease diagnostics and gene sequencing.

Progress of Microbial Enhanced Oil Recovery in Laboratory Investigation

This paper describes a simple, easy process for screening microorganisms, and introduces a laboratory simulation device and process of microbial enhanced oil recovery (MEOR) , which is a necessary research step for trial in oilfields. The MEOR mechanism and the influence of adsorption, diffusion, metabolism, nutrition, porosity, and permeability are analyzed. The research indicates that different microbes have different efficiencies in EOR and that different culture types play different roles in EOR. The effect of syrup is better than that of glucose, and larger porosity is favorable to the reproduction and growth of microbes, thereby improving the oil recovery. Using crude oil as a single carbon source is more appreciable because of the decrease in cost of oil recovery. At the end of this paper, the development of polymerase chain reaction (PCR) for the future is discussed.

Extraction of Total DNA from Populus euphratica Oliv. and Populus pruinosa Schrenk. by Improved CTAB Method

This study presented an improved CTAB method for extracting DNA from leaves of Populus euphratica Oliv. and Populus pruinosa Schrenk. based on the conventional CTAB method. The results showed that preventing DNA from browning is a key step to obtain the high-quality DNA during DNA extraction, and under the condition of grinding in the presence of liquid nitrogen, adding such three antioxidants as PVP dry powder, Vc and β-mercaptoethanol could prevent DNA from browning effectively. The total DNA extracted by the improved CTAB method was subjected to PCR detection which proved that it totally satisfied the requirements of subsequent study.

Clinical significance of serum miR-21 in breast cancer compared with CA153 and CEA

Objective： MicroRNA-21 （miR-21） has been shown to be a key regulator of carcinogenesis. There were few reports about the comparison of serum miR-21 with conventional tumor markers. This study aimed to explore the diagnostic value of circulating miR-21 as a tumor marker in breast cancer （BC） and compare it with CA15 3 and carcinoembryonic antigen （CEA）. Methods： Circulating miR-16 and miR-21 were amplified and quantitatively detected by real-time PCR in 89 BC patients and 55 healthy controls. The levels of CA153 and CEA were measured through assays. Then the sensitivity in diagnosis of BC was compared among miR-21, CA153 and CEA. Results： The level of serum miR-21 was significantly higher in BC patients than controls （P〈0.001）. The sensitivity and specificity of miR-21 were 87.6% and 87.3%, respectively, whereas the sensitivities of CEA and CA153 were only 22.47% and 15.73%. Con^lusions： Compared with CEA and CA153, serum miR-21 has a higher sensitivity in diagnosis of BC. Although not correlated with the status of ER, PR and clinical stages, serum miR-21 may be a potential diagnostic indicator for BC, especially for the early stage.

Laboratory Detection and Diagnosis of Filoviruses

Ebola virus(EBOV) and Marburg virus(MARV),belonging to the Filoviridae family,emerged four decades ago and caused severe viral hemorrhagic fever in human and other primates.As high as 50-90% mortality,filoviruses can cause significant threats to public health.However,so far no specific and efficient vaccine has been available,nor have other treatment methods proved to be effective.It is of great importance to detect these pathogens specific,rapidly and sensitively in order to control future filovirus outbreaks.Here,recent progresses in the development of detection and diagnosis methods for EBOV and MARV are summarized.

Bacterial Translocation and Change in Intestinal Permeability in Patients after Abdominal Surgery

The purpose of this study was to investigate bacterial translocation and change in intestinal permeability in patients after abdominal surgery. Sixty-three patients undergoing elective abdominal surgery were enrolled in the study. Blood samples were collected prior to operation and 2, 24, 48 h after surgery for bacterial culture, microbial DNA extraction, plasma D-lactate and endotoxin measurement. PCR analysis was performed after DNA extraction, with β-lactosidase gene of E. coli and 16S rRNA gene as target genes. All patients were observed for a period of 30 days for infectious complications. Our results showed that no bacterial DNA was detected before surgery, but after operation it was found in 12 patients （19.0%）. Bacterial DNA was detected in 41.7% （10/24） of SIRS patients and 5.1% （2/39） of non-SIRS patients （P〈0.01）. About 83.3% of PCR-positive patients developed systemic inflammatory response syndrome （SIRS）, but only 27.5% of PCR-negative patients did so （P〈0.01）. Two thirds of PCR-positive patients developed infectious complications, while none of PCR-negative patients did （P〈0.01）. The blood culture was positive only in 3 patients （4.8%）, who were all PCR-positive. E. coli DNA was found in 66.7% of the PCR-positive patients. The plasma levels of D-lactate and endotoxin were elevated significantly 2, 24 and 48 h after operation in PCR-positive patients, with a significant positive correlation found between them （r=0.91, P〈0.01）. It is concluded that increased intestinal permeability was closely related with bacterial translocation. Intestinal bacterial translocation （most commonly E. coli） might occur at early stage （2 h） after abdominal surgery. Postoperative SIRS and infection might bear a close relationship with bacterial translocation.

Detection of FLT3/ITD gene mutations in patients with hematologic malignancy and their clinical significance

Objective： To analyze Fms-like tyrosine kinase 3 （FLT3）/internal-tandem duplications （ITD） mutations in various kinds of hematologic malignancy patients. Methods： FLT3/ITD gene mutations were detected by polymerase chain reaction （PCR） in 103 acute myeloid leukemia （AML） cases, 63 acute lymphocytic leukemia （ALL） cases, 53 chronic myelogenous leukemia （CML） cases in chronic phase （CML-CP）, 34 CML cases in blast crisis （CML-BC）, 11 chronic lymphatic leukemia （CLL） cases, 36 myelodysplastic syndrome （MDS） cases, 9 multiple myeloma （MM） cases and 13 non-hodgkin＇s lymphoma （NHL） cases with marrow infiltration. Results： The expressions of FLT3/ITD gene mutations were detected in 22.3% AML cases, in 6.5% CML-BC cases, in 5.6% MDS cases and in 2.6% ALL cases. The two ALL cases with FLT3/ITD mutation were diagnosed as ALL-L2 with morphology and both with myeloid antigen expression, but finally were diagnosed as acute mixed-lineage leukemia after immunology examination. FLT3/ITD gene mutations were not detected in CML-CP, MM, NHL and CLL cases. In the 23 AML patients with FLT3/ITD gene mutation, including 2 of 8 M1 （2.5%）, 8 of 33 M2 （24.2%）, 7 of 24 M3 （29.3%）, 2 of 11 M4 （18.2%）, 3 of 21 M5 （14.3%）, 1 of 5 M6 （20%）, and 0 of 1 M7 cases, and there were no significant differences in the positive rates of FLT3/ITD mutations between the FAB subtypes （P 〉 0.05）. Statistical analyses showed that in AML patients, FLT3/ITD was associated with a higher peripheral blood white cell （WBC） counts [（41.23 ± 32.56） x 109/L vs （11.36 ± 9.89） × 10^9/L （P 〈 0.01 ）], higher percentage of bone marrow blast cells [（72.78 ± 21.79）% vs （51.26 ± 20.78）% （P 〈 0.05）], and higher cumulative relapse rates （63.6% vs 27.7%, P 〈 0.025） than those negative. Conclusion： FLT3/ITD gene mutation mainly occurred in AML patients, and might be a strong prognostic factor which was associated with high peripheral WBC counts, bone marrow blast cell proportion and a increased relapse risk in AML. Detection of FLT3/ITD gene mutation might provide insights to explore a more accurate genotyping of leukemia, differential diagnosis between AML and ALL, subdivide risk level in AML and estimate prognosis of leukemia.

dC14 CAN INHIBIT THE INCIDENCE AND GROWTH OF MOUSE SRS ASCITIC TUMOR

The antiretroviral action of dC14 in vitro has been proven in previous experiments. This paper deals with the effect of dC14 in vivo.Intraperitoneal inoculation of tumor cells into mice without dC14 treatment induced ascitic tumors after a latency of 6 days and death of the mice after 11 days. Both incidence and mortality of disease were 100%. In animals receiving dC14 treatment, the incidence and mortality were less, latency and survival periods were longer. Viral sequences could be detected in tumor cells and in spleens of tumor cell inoculated animals, receiving dC14 treatment or not but could not be detected in normal animals. Studied suggest that the suppressive action of dC14 on the development of mouse SRS ascitic tumor may be through blocking gene expression of virus.

CLONING AND SEQUENCING OF MATURED FRAGMENT OF HUMAN NEVER GROWTH FACTOR GENE

Objective Molecular cloning and sequencing of the human matured fragment of human nerve growth factor(NGF) gene. Methods Extracting the human genomic DNA from the white blood cells as templates, the gene of NGF was cloned by using PCR and T vector cloning method. Screening the positive clones and identified by the restriction enzymes, and then the cloned amplified fragment was sequenced and analyzed. Results DNA sequence comparison the cloned gene of NGF with the GenBank (V01511) sequence demonstrated that both of sequences were identical, 354bp length. Conclusion Cloning the NGF gene from the human genomic DNA has paved the way for further study on gene therapy of nerve system injury.