适配子生物传感器对青霉素的快速检测

将玻碳电极进行阳极氧化和氨基化修饰,通过碳二亚胺盐酸盐(EDC)、N-羟基丁二酰亚胺(NHS)活化作用将青霉素适配子结合在电极表面。该适配子电化学生物传感器分子识别能力强、无放射性标记、检测速率快,青霉素类的最佳检测范围是2.81~281 nmol/L,最低检测限为2.81 nmol/L,检测时间为5 m in。     

Urinary detection of Streptococcus pneumoniae antigen for diagnosis of pneumonia

Streptococcus pneumoniae is one of most common causes of community-acquired pneumonia. We evaluated a newly available rapid immunochromatographic test to detect S. pneumoniae in urine samples verifying its importance in the diagnosis of pneumococcal pneumonia. Our data, obtained from 104 patients with community-acquired pneumonia, show that Now S. pneumoniae Urinary Test is characterized by a sensitivity value of 77.7%, a specifity of 98.8%: positive and negative predictive values are 93.3% and 95.5%, respectively. In conclusion, Now S. pneumoniae Urinary Test should be a useful test to establish the etiology of community-acquired pneumonia.     

Counter-immunoelectrophoresis for the detection of Brucella antigen and antibodies in the diagnosis of brucellosis in buffaloes

Counter-immunoelectrophoresis was employed for the detection of Brucella antigen in stomach contents of aborted buffalo fetuses and antibody in aborted as well as apparently healthy in contact buffaloes. Five of 16 aborted cases were serologically positive for brucellosis but isolation of Brucella abortus was successful in only two cases. By counter-immunoelectrophoresis, Brucella antigen was detected in the fetal stomach contents of four serologically positive cases. Of the 68 serum samples from in contact healthy buffaloes, 10 were positive with counter-immunoelectrophoresis: more than were detected by tube agglutination, Rose Bengal plate agglutination, complement fixation and agar gel precipitation test.     

Counter-immunoelectrophoresis for the detection of Brucella antigen and antibodies in the diagnosis of brucellosis in buffaloes

Counter-immunoelectrophoresis was employed for the detection of Brucella antigen in stomach contents of aborted buffalo fetuses and antibody in aborted as well as apparently healthy in contact buffaloes. Five of 16 aborted cases were serologically positive for brucellosis but isolation of Brucella abortus was successful in only two cases. By counter-immunoelectrophoresis, Brucella antigen was detected in the fetal stomach contents of four serologically positive cases.
Of the 68 serum samples from in contact healthy buffaloes, 10 were positive with counter-immunoelectrophoresis: more than were detected by tube agglutination, Rose Bengal plate agglutination, complement fixation and agar gel precipitation test.     

Detection of Epstein-Barr virus-associated antigen in fine needle aspiration smears from cervical lymph nodes in the diagnosis of nasopharyngeal carcinoma

Epstein-Barr virus (EBV) has consistently been shown to be associated with undifferentiated nasopharyngeal carcinoma, and an EBV-associated nuclear antigen (EBNA) has been detected in the cells of nasopharyngeal carcinoma. A study on the applicability of EBNA detection in fine needle aspiration (FNA) smears from cervical lymph nodes in the diagnosis of metastatic nasopharyngeal carcinoma was performed. All 11 cases (100%) with metastatic nasopharyngeal carcinoma showed EBNA-positive tumor cells, characterized by bright, granulated nuclear fluorescence. Three (50%) of six cases with other metastatic head and neck carcinomas also showed EBNA-positive tumor cells. These findings suggest that the presence of EBNA-positive tumor cells in FNA smears from cervical lymph nodes is not specific for metastatic nasopharyngeal carcinoma. On the other hand, a negative result in the presence of tumor cells may help to exclude it. A larger study is required to verify these preliminary findings.     

Roles of DNA cytometry and detection of EBERs in predicting a diagnosis of nasopharyngeal carcinoma.

OBJECTIVE: To analyze the suitability of DNA cytometry and detection of Epstein-Barr virus (EBV)-encoded RNAs (EBERs) on nasopharyngeal brushings for predicting a diagnosis of nasopharyngeal carcinoma (NPC). STUDY DESIGN: Cytologic preparations in 66 cases suspicious for NPC were evaluated for NPC diagnosis in comparison with the histologic diagnosis. Based on cytologic examination, 38 cases containing cytologically proven cancer and 8 cases interpreted as cytologically negative for cancer with adequate cellularity in the smear specimens were analyzed for DNA ploidy with an image analyzer and for EBER expression by in situ hybridization (ISH). RESULTS: Based on the cytologic diagnosis, DNA aneuploidy analysis, DNA nondiploidy analysis and EBER detection demonstrated a sensitivity of 50%, 84% and 92%, respectively, with the same specificity, 100%, for predicting a diagnosis of cancer. Their negative predictive values were 30%, 57% and 73%, respectively. There was a significant difference between DNA aneuploidy analysis and EBER analysis in sensitivity (P < .001) and in negative predictive value (P < .05) but not between DNA nondiploidy analysis and EBER analysis even though EBER analysis showed a slightly higher value in both parameters (P > .1 and P > .5, respectively). CONCLUSION: ISH for EBERs in cytologic smears showed a role superior to that of DNA aneuploidy analysis in the diagnosis of NPC. Considering its advantages of simple experimental conditions and lower cost as compared with DNA measurement, EBER detection can play a practical and important diagnostic role in patients suspected of having primary NPC.     

The detection of rotavirus RNA in nasopharyngeal smears by molecular hybridization]

Rotavirus RNA was detected in nasopharyngeal washings, obtained from patients with rotavirus gastroenteritis (76.3% of cases) and gastroenteritis of unknown etiology (34.7% of cases), by the method of molecular hybridization with the use of RNA of monkey virus SA11, labeled with 32P in the process of T4-ligase reaction. In 100% of cases this detection correlated with the presence of lesions of the upper respiratory ways and was probably indicative of the rotavirus nature of the catarrhal syndrome in rotavirus gastroenteritis.     

Value of Aspergillus galactomannan antigen detection in the diagnosis and follow-up of invasive aspergillosis in hematological patients

Serum galactomannan detection is considered to be a useful test for early diagnosis and follow-up of invasive aspergillosis. From February to September 2002, adult patients hospitalized in our Hematology Unit for receiving intensive chemotherapy and/or hematopoietic stem cell transplant were prospectively studied. We analyzed a total of 760 samples obtained from 100 patients. Eleven patients (11%) having a positive result (OD index >1.5 ng/ml) in two consecutive Platelia Aspergillus tests were considered galactomannan-positive cases. On the other hand, 12 patients (12%) were diagnosed of proven or probable invasive aspergillosis. Sensitivity (66.6%), specificity (95.5%), positive predictive value (72.7%) and negative predictive value (96.7%) were comparable to those of larger series. Galactomannan positivity allowed also to anticipate invasive aspergillosis diagnosis (from two to 17 days before radiographic findings and from two to 15 days before mycological culture). Moreover, kinetics of antigenemia could be useful for assessing therapeutic response. Once accepted galactomannan test as a diagnostic criterium for invasive aspergillosis knowing potential causes of false positive results is of paramount importance.     

Optimized detection of respiratory viruses in nasopharyngeal secretions

Nasopharyngeal secretions (NPS) from 121 (110 pediatric) patients with acute respiratory infections were examined for respiratory virus detection by: i) conventional virus isolation in cell cultures (CC) using HEp-2, LLC-MK2, and MDCK cells; ii) rapid virus isolation using shell vial cultures (SVC) of a mixture (MIX) of mink lung epithelial cells (Mv1Lu) and human lung carcinoma (A549) cells in comparison to LLC-MK2 and MDCK cells; iii) direct fluorescent antibody (DFA) assay on NPS cells. A pool of monoclonal antibodies (MAbs) to influenzavirus A and B, parainfluenzavirus types 1 to 3, adenoviruses and respiratory syncytial virus (RSV), as well as single MAbs to the same viruses, were used for virus identification in all three procedures. Results on 101 NPS examined in parallel showed a sensitivity of 89.5%, 73.7%, and 81.6% for CC, SVC, and DFA, respectively, with the relevant negative predictive values of 94.0%, 86.3%, and 90.0%. Specificity and positive predictive values were 100%. However, the combination of DFA and SVC gave best results in terms of sensitivity (94.7%) and negative predictive value (95.5%). Use of the new MIX cell culture system in the SVC procedure enhanced virus detection, while use of the MAb pool allowed prompt identification of negative samples and saving of reagents and time for all three procedures. The combination of DFA and SVC allows diagnosis of the large majority of viral respiratory infections within 48h, while conventional virus isolation on CC may be limited to laboratories involved in research and epidemiological studies.     

Epstein-Barr viral antigens used in the diagnosis of nasopharyngeal carcinoma

The major antigen complexes of Epstein-Barr virus (EBV) include the latent infectious proteins, early antigens, membrane antigens and viral capsid antigens. The various polypeptides within each antigen complex have been identified and isolated through gene-cloning technology. These polypeptides are exploited to be used as serological markers for the diagnosis of nasopharyngeal carcinoma (NPC) through enzyme-linked immunosorbent assay. This paper reviews the recent studies on the profile of antibodies in patients with NPC towards these EBV polypeptides of each antigen complex. The sensitivity and specificity of each polypeptide when used as serological markers to NPC patients' sera are summarized.     

Magnetic resonance tomography in the diagnosis of juvenile nasopharyngeal angiofibromas

This work is based upon the experience in the diagnosis of juvenile nasopharyngeal angiofibromas (JAF) in 14 patients using MR-tomography and routine x-ray examination. In all the patients MR-tomography made it possible to assess the topical position of a tumor, its spreading to the cranial, nasal, accessory sinusal and orbital cavities, and the pterygopalatine and infratemporal spaces. MR-tomographic diagnosis made it possible to differentiate between tumor invasion and inflammatory processes detecting JAF attending tubotitides. However MR-tomography cannot be used alone to assess the status of osseous tissue.