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At least 289 records · Page 16Linked to original sources
PubMed2003

Pathologic comparison of laparoscopic versus open radical retropubic prostatectomy specimens.

OBJECTIVES: To compare the pathologic evaluation of 60 sequential laparoscopic radical prostatectomy (LRP) specimens with 60 sequential and 60 stage and grade-matched open radical retropubic prostatectomy (RRP) cohort specimens. METHODS: Of 68 patients undergoing LRP, 3 requiring open conversion and 5 receiving neoadjuvant hormonal therapy were excluded, leaving 60 for analysis. Among 72 sequential open RRP specimens, 60 from patients not receiving neoadjuvant hormonal therapy and without nodal metastases were analyzed. A third cohort of 60 RRP specimens matched with the LRP specimens for clinical stage and biopsy grade was also evaluated. RESULTS: The specimen weight and preoperative serum prostate-specific antigen level were similar for each cohort, and approximately 75% of patients from each cohort were clinical Stage T1c. Forty-six LRP and matched open RRP (76.7%) and 39 sequential open RRP (65%) specimens were biopsy Gleason sum 6, and the remainder were primarily Gleason sum 7. The pathologic grade and stage distribution were similar for each cohort. Ten LRP (16.9%) and 12 open RRP (20%) specimens from each cohort had positive inked margins (P > 0.10). Positive apex margins were noted in 3, 7, and 7 and multiple positive margin sites in 0, 5, and 6 of the LRP, matched open RRP, and sequential open RRP specimens (P < 0.05), respectively. CONCLUSIONS: Pathologic evaluation of the LRP and open RRP specimens from patients not receiving neoadjuvant hormonal therapy demonstrated similar overall positive margin rates, but LRP had a lower rate of apex and multiple-site positive margins.

Biopsy, Needle↗
PubMed2004

The influence of interfacial surface roughness on bilayered ceramic specimen performance.

OBJECTIVES: The aim of the current study was to assess the influence of interfacial surface roughness on the performance of bilayered ceramic composite disc-shaped specimens. METHODS: Specific surface flaw distributions were introduced to a series of standard aluminous core porcelain disc specimens (12 mm diameter, 1.7 mm thickness) prior to bilayering with dentin porcelain. Mean flexure strengths, standard deviations and associated Weibull moduli (m) were determined using bi-axial flexure (ball-on-ring) for each series of 30 bilayered specimens. RESULTS: The mean bi-axial fracture strengths of bilayered specimens resulted in significant differences between specimen groups with the smoothest interfacial roughness recording the highest strength and fracture strength reliability. Specimen delamination was identified in five of the bilayered group with the smoothest interfacial roughness compared with no specimen delaminations in the rougher interface groups. However, fracture occurred in the weaker dentin layer rather than along the interface between the dentin and core porcelain for specimens in these rougher interface groups. CONCLUSIONS: A smoother interfacial surface roughness resulted in increased performance, namely increased strength and reliability amongst the bilayered dental ceramic composite specimens examined in the current investigation. The incidence of complete or partial delamination of the reinforcing core and aesthetic dentin was increased for these specimens since the reduced tortuosity of the interface between porcelain layers fails to restrict propagation of a crack front along the interface.

Aluminum↗
PubMed2003

Effect of test specimen cross-sectional shape on the in vitro fatigue life of acrylic bone cement.

Constant-amplitude uniaxial tension-compression fatigue tests were conducted on specimens fabricated from 12 sets of acrylic bone cements, covering cement formulations with three different viscosities (so-called "high-", "medium-" and "low-viscosity" varieties), two different methods of mixing the cement constituents (so-called "hand-" and "vacuum-mixed" methods) and two test specimen shapes (rectangular-cross-sectioned or "flat" and circular-cross-sectioned or "round"). The test results-namely, the number of fatigue stress cycles, N(f)-were analyzed using the linearized transformation of the three-parameter Weibull relationship, allowing the values of the Weibull mean, N(WM), to be determined for each set. Values ranged from 14,300 to 1,284,331 for the round specimen sets and from 2898 to 72,960 for the flat specimen sets. Statistical analysis of the ln N(f) data, together with an examination of the N(WM) values, showed that, for any combination of cement formulation and mixing method, round specimens had significantly longer fatigue lives compared to flat ones. These results are explained in terms of two factors. The first is the smaller surface area of the waisted zone in the round specimens compared to that in the flat specimens (nominal value of 157mm(2) versus nominal value of 185mm(2)), leading to the possibility of fewer crack initiation sites on the round specimens compared to the flat ones. Secondly, it is postulated that the crystallinity of the round specimens was higher than that of the flat ones, a consequence of the significantly lower measured residual liquid monomer contents of the former compared to the latter (3.40+/-1.28wt%/wt compared to 3.81+/-1.48wt%/wt). The significance of the present finding is that it indicates that, for a set of bone cement formulation and experimental conditions, discriminating fatigue test results are more likely to be obtained if flat, rather than round, test specimens are used.

Acrylic Resins↗
PubMed2003

High prevalence of 6-acetylmorphine in morphine-positive oral fluid specimens.

Identification of 6-acetylmorphine, a specific metabolite of heroin, is considered to be definitive evidence of heroin use. Although 6-acetylmorphine has been identified in oral fluid following controlled heroin administration, no prevalence data is available for oral fluid specimens collected in the workplace. We evaluated the prevalence of positive test results for 6-acetylmorphine in 77,218 oral fluid specimens collected over a 10-month period (January-October 2001) from private workplace testing programs. Specimens were analyzed by Intercept immunoassay (cutoff concentration=30 ng/ml) and confirmed by GC-MS-MS (cutoff concentrations=30 ng/ml for morphine and codeine, and 3 ng/ml for 6-acetylmorphine). Only morphine-positive oral fluid specimens were tested by GC-MS-MS for 6-acetylmorphine. A total of 48 confirmed positive morphine results were identified. An additional 107 specimens were confirmed for codeine only. Of the 48 morphine-positive specimens, 32 (66.7%) specimens were positive for 6-acetylmorphine. Mean concentrations (+/-S.E.M.) of morphine, 6-acetylmorphine and codeine in the 32 specimens were 755+/-201, 416+/-168 and 196+/-36 ng/ml, respectively. Concentrations of 6-acetylmorphine in oral fluid ranged from 3 to 4095 ng/ml. The mean ratio (+/-S.E.M.) of 6-acetylmorphine/morphine was 0.33+/-0.06. It is suggested that, based on controlled dose studies of heroin administration, ratios >1 of 6-acetylmorphine/morphine in oral fluid are consistent with heroin use within the last hour before specimen collection. The confirmation of 6-acetylmorphine in 66.7% of morphine-positive oral fluid specimens indicates that oral fluid testing for opioids may offer advantages over urine in workplace drug testing programs and in testing drugged drivers for recent heroin use.

Codeine↗
PubMed2003

Evaluation of the BDProbeTec ET system as screening tool in the direct detection of mycobacterium tuberculosis complex in respiratory specimens.

We evaluated the BDProbeTec ET System (Becton Dickinson) for the routine detection of Mycobacterium tuberculosis complex (MTC) in respiratory specimens and pleural fluids, comparing with microscopy (Ziehl Neelsen stain, ZN) and culture in liquid (BACTEC MGIT 960, MGIT) and solid (Löwenstein Jensen, LJ) media. Five hundred and two specimens, collected from 266 patients, of which 257 with suspected tuberculosis and 9 receiving anti-tuberculosis treatment, were investigated. Thirty-nine specimens were positive by any method, including false positives. Mycobacteria were isolated from 33 specimens (32 Mycobacterium tuberculosis and 1 Mycobacterium chelonae). Thirty-six specimens were BDProbeTec ET positive, 33 specimens were MGIT positive, 27 were LJ positive and 22 were ZN positive. With BDProbeTec ET, 2 specimens were false negative (culture positive), and 2 specimens from non-treated patients were false positive (culture negative). The overall sensitivity, specificity, and positive and negative predictive values for BDProbeTec ET compared to culture were 93.7, 98.7, 83.3, and 99.5%, respectively, while with smear-positive and smear-negative specimens the sensitivities were 100% and 81.5% respectively. In five treated patients the disappearance of MTC could be monitored using BDProbeTec ET in parallel with culture. The overall inhibition rate was 0.2%. BDProbeTec ET can be very useful for rapid detection of MTC, especially in smear-negative respiratory specimens.

Bacterial Typing Techniques↗
PubMed2003

Successful HCV genotyping of previously failed and low viral load specimens using an HCV RNA qualitative assay based on transcription-mediated amplification in conjunction with the line probe assay.

BACKGROUND: Hepatitis C virus (HCV) genotyping is a critical part of the diagnostic work-up for chronic hepatitis C. The VERSANT HCV line probe assay (LiPA) marketed by Bayer Corporation requires PCR-derived amplicons for genotyping usually obtained from commercial assays, including Amplicor HCV 2.0 (Amplicor 2.0), Amplicor HCV Monitor 2.0, or SuperQuant. Occasionally, PCR-based methods in conjunction with LiPA fail to give a genotyping result. Although most genotyping failures occur among low viral load specimens, some occur in specimens with relatively high viral loads. The Bayer HCV RNA Qualitative assay (HCV TMA), with a limit of detection of approximately 5-10 IU/ml, is more sensitive than other commercial assays. OBJECTIVES: An HCV genotyping protocol using HCV TMA linked with LiPA (TMA-LiPA) was developed and tested for ability to genotype samples that had previously failed genotyping by PCR-based methods in conjunction with LiPA. STUDY DESIGN: Clinical specimens were obtained from eight independent laboratories in Canada and the US and tested with TMA-LiPA at the Bayer Reference Testing Laboratory. Specimens included those that failed to produce a genotype result when a PCR-based assay was used in conjunction with LiPA and specimens for which genotyping was not attempted because the viral load was below the validated cut-off determined in the laboratory of origin. RESULTS AND CONCLUSIONS: TMA-LiPA successfully genotyped 68 of 75 (90.7%) specimens that had failed genotyping by PCR-based methods used in conjunction with LiPA and 36 of 40 (90.0%) specimens that were rejected for genotyping due to low viral load. Moreover, TMA-LiPA assigned subtype for 79 of 107 (73.8%) specimens. Our TMA-LiPA results reflected the distribution of HCV genotypes found in North America, and were 100% concordant with those of Amplicor 2.0 in conjunction with LiPA for control specimens genotyped by both assays. TMA-LiPA may prove useful both in optimizing LiPA performance and genotyping patient specimens.

Genotype↗
PubMed2002

Characterization of tissue components in the temporomandibular joint disc and posterior disc attachment region: internal derangement and control autopsy specimens compared by morphometry.

PURPOSE: Our aim was to morphologically investigate the occurrence of fibroblasts, chondrocytes, and blood vessels in the tissue of the temporomandibular joint (TMJ) disc, the intermediate zone, and the posterior disc attachment region in control autopsy specimens and to compare the results with those observed in corresponding tissues from patients with TMJ internal derangement. PATIENTS AND METHODS: First, 20 bilateral TMJ disc specimens from selected autopsy cases were analyzed by conventional morphometry. Thus, the volume density of fibroblasts, chondrocytes, and blood vessels was determined. Second, the obtained results from the right joint of the autopsy disc specimens were compared with 12 TMJ disc specimens obtained at surgery from patients with internal derangement. RESULTS: The tissue compartments of interest (disc, intermediate zone, and posterior disc attachment region) were identified unequivocally in all specimens. None of the autopsy cases showed any significant difference between the right and left joints or related to gender. The only variable that differed between autopsy and patient specimens was volume density of blood vessels, which was higher in patient specimens. CONCLUSIONS: We found that the volume density of blood vessels was significantly higher in the posterior disc attachment region in patient specimens than in autopsy controls. Whether this reflects a role for vessels in the pathogenesis of TMJ internal derangement or merely is a reaction to another type of injury remains to be settled. In both the autopsy control and patient specimens, chondrocytes and fibroblasts were characteristic for disc respective posterior disc attachment region. Thus it appears that the occurrence of these cells can be used to distinguish TMJ disc from posterior disc attachment in small biopsy specimens.

Adolescent↗
PubMed2004

[Real-time PCR assay for rapid detection of clarithromycin-resistant helicobacter pylori in gastric biopsy specimens].

The main cause for failure of Helicobacter pylori eradication therapy is resistance to clarithromycin which is due to point mutations. The use of real-time PCR allows the detection of these mutations directly on biopsy specimens within a few hours. In our routine laboratory, we compared LightCycler PCR to conventional detection and susceptibility testing of H. pylori by culture. PCR showed a positive result for H. pylori in 74 specimens. PCR was confirmed by culture in 69 specimens. In five specimens which were positive by PCR but negative on culture the (13)C urea breath test confirmed the PCR results. Sensitivity and specificity of our LightCycler assay for the detection of H. pylori in biopsy specimens were both 100 %. In 26 out of 68 specimens conventional susceptibility testing yielded resistance to clarithromycin. Corresponding point mutations were found in 24 of these specimens. Compared to culture, PCR gave a false-resistant, respectively, a false sensitive result in one specimen each. In another specimen, culture yielded a resistant strain whereas PCR detected both a resistant mutant and the wild-type strain. From two other specimens clarithromycin-sensitive strains were cultured but both a wild-type strain and a mutant were detected by PCR. Sensitivity and specificity of LightCycler PCR for resistance to clarithromycin were 96.2 % and 97.6 %, respectively. This assay had an accuracy comparable to culture and could be performed within 3 hours, allowing it to be used before the administration of H. pylori eradication therapy.

Adult↗
PubMed1992

Predictive value of specimen histology after preoperative radiotherapy in the treatment of bulky/barrel carcinoma of the cervix.

One hundred thirty-four patients with bulky and barrel-shaped cervix cancers were treated with preoperative radiation to 40-45 Gy, intracavitary therapy using Cs-137 or Cf-252 and extrafascial total abdominal hysterectomy and bilateral salpingo-oophorectomy (TAHBSO) 4-6 weeks after radiotherapy. Outcome of therapy was traced for patients with residual tumor (positive) in the hysterectomy specimen and those who had no residual tumor (negative) in the specimens. All specimens were studied by a set protocol to carefully evaluate the TAHBSO specimen for gross or residual tumor. Ninety-two percent of the patients with negative specimens survived 5 years, but this dropped to 71% if the specimen was positive. These findings were observed in both the Cs-137- and Cf-252-treated patients. Patients with negative specimens failed mainly in distant sites, whereas those with positive specimens failed locally and distantly. Patient survival was less in patients with positive specimens. There was no difference in outcomes for adenocarcinoma and squamous cell carcinomas. The specimen histological findings have predictive value in patients treated with preoperative radiation and surgery.

Actuarial Analysis↗
PubMedDate not supplied

Relationships between young modulus of elasticity, ash density, and MRI derived effective transverse relaxation T2* in tibial specimens.

OBJECTIVE: It has been hypothesized that the MR relaxation time T2* of bone marrow present in the intertrabecular spaces may be related to the density of the trabecular network and may be a predictor of trabecular bone properties. MATERIALS AND METHODS: To derive a relationship between the marrow relaxation time T2* and biomechanical properties of trabecular bone, we studied two sets of trabecular bone specimens from human tibiae. The first set consisted of 12 specimens that were defatted and immersed in saline; the second set consisted of 18 specimens with marrow in the trabecular spaces. The MR studies were conducted on a 1.5 T imaging system. In the first set of specimens, a GE sequence (TR = 70 ms; TE = 5, 10, 15, 20, 25 ms) was used to obtain images in the axial plane. In the second set, a water suppression pulse was used prior to an asymmetric SE sequence (TR = 300 ms; TE = 4, 8, 12, 16, 20, 24 ms) to obtain images in the axial, coronal, and sagittal planes. The T2* of the intertrabecular saline of the marrow fat was calculated assuming a monoexponential decay. In both sets, the elastic moduli were measured in three orthogonal directions (superoinferior, anteroposterior, and mediolateral). The ash density was determined after the completion of the experiments. RESULTS: Our results indicate a moderate significant negative correlation between T2* and ash density or elastic modulus (E) in both sets of specimens. The correlation coefficients were slightly improved between the transverse relaxation rate 1/T2* and bone density or E. We found a good correlation between T2* and the reciprocal ash density (r = 0.88) and between T2* and the reciprocal elastic modulus 1/E (r = 0.87 to r = 0.95) in the first set, while in the second set the correlation remained moderate. With use of a multiple linear regression model (1/E = a x T2* + b x 1/T2* + n), the reciprocal elastic moduli 1/E were predicted to > 90% by T2* and 1/T2* in the first set of specimens. This finding was not replicated with the second set of specimens. In the second set of specimens, we found poor to moderate correlation coefficients between the T2* times in the three orthogonal planes (r = 0.45 to r = 0.71). CONCLUSION: Trabecular bone properties such as density and strength may potentially be assessed with quantitative MR techniques. However, especially for in vitro studies, specimen preparation, acquisition parameters, and specimen geometry may have a significant impact on the obtained results.

Bone Density↗
PubMed1996

The need for standardized pathologic staging of pancreaticoduodenectomy specimens.

A standardized method for pathologic evaluation and staging of pancreaticoduodenectomy (PD) specimens is critical for accurate reporting of the number and location of lymph nodes and margins of resection. We examined the impact of standardized pathologic evaluation (SPE) of PD specimens on the identification of regional lymph nodes and describe our detailed system for the pathologic analysis of the PD specimen. Forty consecutive patients underwent PD for histologically confirmed adenocarcinoma of the pancreatic head between April 1990 and August 1993. Fifteen consecutive specimens were examined before the introduction of the SPE, and 25 consecutive specimens underwent SPE. Resection margins were evaluated by frozen-section analysis, and then the specimen was divided into six regions on an anatomic dissection board for lymph node identification. The 25 specimens examined according to the SPE had a significantly increased number of lymph nodes identified (P = 0.0001) compared with the 15 specimens examined without the SPE. Twelve of the 25 specimens contained positive lymph nodes, 6 of which were confined to the pancreaticoduodenal region. No positive nodes were found in the periaortic region. There were no differences in pathologic variables between patients found to have negative and those with positive regional lymph nodes. SPE of PD specimens provides a method for improved lymph node identification, ensures accurate prospective evaluation of margins of resection, and provides a complete analysis of potentially important pathologic variables. We offer this system as a standardized model for groups engaged in protocol-based clinical research examining innovative multimodality treatment strategies for patients with resectable pancreatic cancer.

Adenocarcinoma↗
PubMedDate not supplied

Detection of Chlamydia trachomatis in genitourinary tract specimens using an automated enzyme-linked fluorescent immunoassay.

BACKGROUND AND GOAL: The VIDAS Enzyme Linked Fluorescent Assay is a fully automated assay for the detection of Chlamydia trachomatis in clinical specimens. Because there is an increasing demand for automated assays for large volume laboratories and there is little performance data available, the authors evaluated the performance of the VIDAS enzyme linked fluorescent assay by comparing it with Chlamydiazyme and polymerase chain reaction. STUDY DESIGN: Endocervical swabs from 330 women attending a hospital based obstetrics/gynecology clinic and 100 first void urine specimens from males attending a sexually transmitted disease clinic were tested by enzyme linked fluorescent assay, Chlamydiazyme, and polymerase chain reaction. RESULTS: Fourteen of 330 endocervical specimens and 14 of 100 first void urine specimens were positive by Chlamydiazyme. Enzyme linked fluorescent assay detected 12 of 14 endocervical and 11 of 14 first void urine specimens. Compared with Chlamydiazyme, enzyme linked fluorescent assay had a sensitivity of 85.7% (12 of 14) for endocervical swabs and 76.9% (11 of 14) for first void urine specimens. Polymerase chain reaction detected an additional five endocervical and two first void urine specimens that had negative results by both enzyme linked fluorescent assay and Chlamydiazyme. All 7 were confirmed positive by polymerase chain reaction using a second primer set. Using an expanded gold standard of blocked Chlamydiazyme and confirmed polymerase chain reaction, enzyme linked fluorescent assay had a sensitivity of 63.2% (12 of 19) for endocervical swabs and 68.8% (11 of 16) for first void urine specimens compared with 73.7% (14 of 19) and 87.5% (14 of 16) for Chlamydiazyme. Polymerase chain reaction had a sensitivity of 100% (19 of 19) and 93.8% (15 of 16) for endocervical swabs and first void urine specimens, respectively. The specificity of enzyme linked fluorescent assay and Chlamydiazyme was 100%. CONCLUSIONS: The VIDAS enzyme linked fluorescent assay for the detection of Chlamydia trachomatis in genitourinary specimens is highly specific but is not sufficiently sensitive for use as a routine diagnostic test.

Automation↗
PubMed1999

Evaluation of lymphoid cell populations in cytology specimens using flow cytometry and polymerase chain reaction.

Differential diagnosis between lymphomas and reactive lymphoid proliferations often requires ancillary techniques and morphologic evaluation. Flow cytometry (FCM) and polymerase chain reaction (PCR) can aid the detection of monoclonal B-cell populations. In the present study, the sensitivity and specificity of these two methods in the study of cytology specimens were compared. Eighty-six cytologic specimens from 81 patients (lymph nodes, solid organs, and body cavities) were evaluated. These specimens were taken from three groups of patients: those who underwent an initial evaluation for suspected lymphoma; those who were previously diagnosed with B-cell lymphoma and were now evaluated for possible disease recurrence; and those who were diagnosed with a nonhematologic malignancy. Histologic diagnosis was available for 51 samples. All samples were tested by FCM for the detection of monoclonality using kappa:lambda ratio and for clonal immunoglobulin heavy chain (IgH) gene rearrangements using a single-round PCR after cytologic evaluation. Tissue morphology, FCM and PCR results, and clinical findings in specimens without histologic diagnosis were correlated. Histologic evaluation (N = 51) revealed 44 specimens with B-cell malignancy. Twenty of the 44 lymphoma specimens (45%) were accurately diagnosed in cytologic smears, 18 (41%) were classified as suspicious of lymphoma, and 6 (14%) were diagnosed as reactive. FCM had superior sensitivity compared with PCR (77% vs. 64%). Fifty-six percent of specimens with B-cell malignancy were FCM+/PCR+, 23% were FCM+/PCR-, 14% were FCM-/PCR+, and 7% were FCM-/PCR-. The combined use of FCM and PCR resulted in a diagnosis of B-cell lymphoma in 41 (93%) of 44 B-cell lymphoma specimens and increased the sensitivity of fine needle aspiration by 48%. Both FCM and PCR aid in the diagnosis of lymphoid lesions in cytology specimens, and both can detect monoclonal B-cell populations that may be interpreted in cytology smears as reactive, even by experienced cytologists. Although FCM had higher sensitivity than PCR test in the present study, their combined use should be considered because of a relatively large number of specimens that were detected as monoclonal only with PCR.

Biopsy, Needle↗
PubMed2004

Immunohistochemical stains fail to increase the detection rate of micrometastatic melanoma in completion regional lymph node dissection specimens.

In melanoma patients, examination of tissue sections stained for immunohistochemical markers as an adjunct to examination of haematoxylin and eosin (H&E)-stained sections has been shown to increase the detection rate of micrometastatic disease in sentinel lymph nodes (SLNs). However, immunohistochemical stains are not routinely performed on completion regional lymph node dissection (CLND) specimens in most centres and it is not known whether their use would increase the detection of micrometastatic disease in these specimens. This study was performed to determine whether the application of immunohistochemical stains for S100 and HMB45 (in addition to H&E stains) increases the detection of micrometastatic disease in CLND specimens of melanoma patients and whether their use would be cost-effective in routine pathological practice. Forty-nine CLND specimens from patients with a prior positive SLN biopsy were examined by performing H&E stains and immunohistochemical stains for S100 protein and HMB-45 on each node, and the detection rate of melanoma metastases using H&E-stained sections was compared with that using immunohistochemically stained sections. The number of nodes in the CLND specimens ranged from 4 to 37 (median 14, mean 14.7). Nodal deposits of melanoma cells were detected in 12 of 49 cases (24%). Among these 12 positive cases, the mean number of positive nodes per CLND specimen was 2.2 (range, 1-14). The total number of positive nodes in the 12 CLND specimens was 27, accounting for 3.8% of the 720 nodes removed in the study group of 49 cases. Melanoma cells in all 27 positive nodes were identified both on the H&E-stained slides and the slides stained immunohistochemically for S100. The melanoma cells were positive for HMB45 in 24 of the 27 lymph nodes that contained metastatic melanoma (the metastatic melanoma cells were negative for HMB45 in three positive nodes from one specimen). No further positive lymph nodes were detected with the immunostains that had not been identified on the H&E-stained sections. This study suggests that the use of immunostains does not increase the detection rate of metastatic melanoma in CLND specimens, and that their routine use would not be cost-effective. We therefore recommend only H&E staining on sections of all lymph nodes in CLND specimens from melanoma patients.

Humans↗
PubMed1995

Detection of Mycobacterium tuberculosis in clinical specimens other than sputum by a specific DNA probe with amplification of the ribosomal RNA.

OBJECTIVE: To evaluate the Gen-Probe Amplified Mycobacterium tuberculosis Direst Test (MTD) for detection of Mycobacterium tuberculosis in clinical specimens other than sputum, especially cerebrospinal fluid (CSF) and pleural fluid (PF) specimens. DESIGN: Six CSF, 17 PF and 23 bronchoalveolar lavage fluid (BALF) specimens that were submitted to our clinical laboratory for detection of mycobacteria were subjected to MTD and conventional smear and culture examinations. RESULTS: Of 6 smear-negative CSF specimens, two were positive in MTD and culture examination. In PF specimens, two of 15 smear- and culture-negative specimens were positive in MTD, while one smear-negative but culture-positive specimen was MTD negative. Three of 20 smear- and culture-negative BALF specimens were positive in MTD. Three BALF specimens in which mycobacteria other than the M. tuberculosis complex detected by culture were negative in MTD. CONCLUSION: MTD is very useful for rapid detection of M. tuberculosis in clinical specimens other than sputum as well as sputum, and should be especially valuable for rapid diagnosis of tuberculous meningitis which requires prompt initiation of appropriate anti-tuberculosis drug treatment.

Bronchoalveolar Lavage Fluid↗
PubMed1988

Detection of respiratory syncytial virus in clinical specimens by viral culture, direct and indirect immunofluorescence, and enzyme immunoassay.

We evaluated prospectively the detection of respiratory syncytial virus (RSV) by culture and by direct antigen detection using an indirect immunofluorescence assay (IFA), a direct monoclonal immunofluorescence assay (DFA), and a monoclonal enzyme immunoassay (EIA). Of 221 specimens, 95 (43%) were culture positive for RSV, 4 (1.8%) contained more than one virus, and 17 (7.6%) contained a virus other than RSV. Overall, HEp-2 and Flow 6000 cells grew significantly more RSV isolates (82 and 72%, respectively) than A549 cells, which grew only 29% of the isolates. The mean time for RSV detection with HEp-2 cells was 2.9 days. This was significantly less than the mean time for RSV detection with either Flow 6000 cells (6.1 days) or A549 cells (6.4 days). Of 221 specimens, 129 were tested simultaneously by culture, IFA, and DFA. Of these 129 specimens, 62 (48%) were positive by culture, 69 (53%) were positive by IFA, and 70 (54%) were positive by DFA. For 92 specimens screened simultaneously by culture, IFA, and EIA, positive results were obtained for 33 (36%) of the specimens by both culture and IFA and for 29 (32%) of the specimens by EIA. Of 126 culture-negative specimens, 21 (17%) were positive for RSV when determined by IFA. Conversely, 14 (15%) of 95 RSV culture-positive specimens were negative by IFA, whereas DFA missed 19% of the culture-positive specimens. Compared with culture, the Kallestad EIA kit had a sensitivity and specificity of 73 and 92% respectively, but missed 9 (27%) of 33 culture-positive specimens. These data demonstrate that isolation by culture continues to be important for viral diagnosis of REV infections and that for valid comparative studies between viral isolations and rapid detection methods, both sensitive host cells and appropriate test conditions are required.

Cell Line↗
PubMed1990

Effect of endocervical specimen quality on detection of Chlamydia trachomatis and on the incidence of false-positive results with the Chlamydiazyme method.

Duplicate endocervical swabs were collected from 1,675 patients to assess the effects of variations in specimen quality on Chlamydiazyme (Abbott Laboratories) detection of Chlamydia trachomatis and the incidence of false-positive results. One swab (at random) from each patient was tested for C. trachomatis antigen by using the standard Chlamydiazyme procedure. A 200-microliter volume of 0.9% saline was added to the other swab from each patient. After vortexing, 20 microliters was smeared on a slide for Papanicolaou (Pap) staining and the remaining specimen was then tested with the Chlamydiazyme assay. The Chlamydiazyme result was positive for 170 (10.1%) and 165 (9.8%) of the stained and unstained duplicate specimens, respectively (no significant difference). Pap stains on smears from 1,536 (91.7%) of the patients were analyzed, and endocervical and/or metaplastic (E-M) cells were detected in 789 (51.4%) smears. Of these 1,536 stained and analyzed specimens, 150 (9.8%) were Chlamydiazyme positive but only 132 (88.0%) of the positive results were confirmed by repeating the test and using a monoclonal blocking antibody (Abbott). Confirmed Chlamydiazyme-positive results were obtained from only 34 (4.6%) of 747 specimens lacking E-M cells but from 98 (12.4%) of 789 specimens containing the cells (P less than 0.001). Of the 150 initially Chlamydiazyme-positive results obtained with Pap-stained, analyzed specimens, 12 (26.1%) of 46 were falsely positive from specimens lacking E-M cells but only 6 (5.8%) of 104 were falsely positive from specimens containing E-M cells (P less than 0.01). C. trachomatis antigen was detected significantly more frequently and false-positive results were significantly less common from specimens in which E-M cells were detected.

Adolescent↗
PubMed1996

Rapid colorimetric hybridization assay for detecting amplified Helicobacter pylori DNA in gastric biopsy specimens.

A very simple, practical, sensitive, and specific colorimetric hybridization assay for detecting amplified Helicobacter pylori DNA is described. This assay, which combines a sensitive sandwich DNA hybridization reaction and a colorimetric protocol similar to those used in conventional enzyme immunoassays, was shown to be suitable for detecting H. pylori-infected gastric biopsy specimens and for monitoring the eradication of the pathogen after treatment. The specificity and sensitivity of the colorimetric hybridization assay were tested by assaying 27 H. pylori strains (4 reference and 23 clinical isolates), 9 strains of other Helicobacter spp. or Campylobacter spp., and 11 clinical isolates of other urease-positive bacteria. The likelihood of H. pylori detection in gastric biopsy specimens by the colorimetric hybridization assay was evaluated with 23 H. pylori-positive and 41 H. pylori-negative biopsy specimens on the basis of positive and negative results, respectively, of culture, rapid urease test, histological examination, and PCR. Biopsy specimens from 33 treated patients, endoscopied 4 to 8 weeks after the end of treatment, were also tested. All H. pylori strains showed positive results in the colorimetric hybridization assay, presenting optical densities at 450 nm (OD450S) of > or = 3.0. None of the other Helicobacter spp., Campylobacter spp., or the clinical isolates of other urease-positive bacteria showed OD450S equal to or greater than the cutoff (mean OD450 cutoff, 0.208). The colorimetric hybridization assay detected all 23 H. pylori-positive biopsy specimens (mean OD450, 2.910 +/- 0.295), while none of the H. pylori-negative biopsy specimens was shown to be positive in the assay (mean OD450, 0.108 +/- 0.025). H. pylori was considered to be not eradicated from three of the posttreatment biopsy specimens by culture, rapid urease test, histological examination, and PCR. They were all positive by the colorimetric hybridization assay, and their OD450S were > or = 3.0. The colorimetric hybridization assay also detected two other H. pylori-positive patients. Specimens from these two patients had negative culture, rapid urease test, and histology results, and a specimen from one of them also tested negative by PCR. These results indicate that the colorimetric hybridization assay is a suitable method both for the diagnosis of H. pylori in biopsy specimens and for the follow-up of patients after the end of treatment.

Base Sequence↗