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PubMed2006

Preparation of a single prostate needle biopsy specimen for histological diagnosis and RNA analysis.

PURPOSE: When a prostate needle biopsy specimen is used for molecular study, a second specimen from the same area as the first one has previously been required for pathological diagnosis. However, we developed a method for obtaining substances such as RNA and we also made pathological diagnosis possible from a single needle biopsy specimen, improving reliability. MATERIALS AND METHODS: Prostate needle biopsy specimens from 118 patients were frozen in optimal cutting temperature compound. Tissue from the upper part of the frozen specimen was sectioned longitudinally for histopathological examination. The remainder of the specimen was placed in TRIzol reagent to extract total RNA for molecular biological investigation. RESULTS: Pathological diagnosis and total RNA extraction (1.6 to 32.7 microg) could be obtained from 1 needle biopsy specimen. When 2 specimens were obtained from the same area of the prostate, pathological diagnoses were discordant in 19% of the cases. CONCLUSIONS: We established a method for histopathological diagnosis in the prostate needle biopsy specimen used for molecular investigation. This single specimen method may facilitate molecular research in prostate cancer.

Aged↗

PubMed1992

Evaluation of culture and the Gen-Probe PACE 2 assay for detection of Neisseria gonorrhoeae and Chlamydia trachomatis in endocervical specimens transported to a state health laboratory.

The Gen-Probe PACE 2 assay (Gen-Probe Inc., San Diego, Calif.) was compared with culture for the detection of Neisseria gonorrhoeae in endocervical specimens that were mailed to the laboratory. During mail transport, the specimens were exposed to extremes of hot and cold weather for several days before arriving in the laboratory. Specimens on culture plates deteriorated during transport, as evidenced by many dead gonococcus-like colonies. The manufacturer's recommendation for reporting PACE 2 assay-positive results was modified to create a suspicious category for samples with relative light units near the positive cutoff value. Of a total of 4,869 specimens tested, 30 were positive by both methods and 102 were positive only by the PACE 2 assay. These additional 102 positive specimens were likely to be true positives, as indicated by several lines of indirect evidence, including detailed probe competition analysis, patient history, and the lack of false-positive results in hand-delivered specimens. Although Gen-Probe Inc. indicates that specimens are stable for up to 7 days, N. gonorrhoeae was easily detectable by the PACE 2 assay after 1 month of incubation at room temperature in the PACE 2 transport buffer. We also compared the Gen-Probe PACE 2 assay for Chlamydia trachomatis with culture on endocervical specimens delivered by same-day courier. Of 398 endocervical specimens tested, the PACE 2 assay detected 19 of 20 culture-positive samples. Although the assay failed to detect one culture-positive sample, it was able to detect two very weak culture-suspicious samples. Finally, PACE 2 assays for N. gonorrhoeae and C. trachomatis performed on the same samples indicated that the coinfection rate was 40% for women attending five family planning clinics. We concluded that the Gen-Probe PACE 2 assay system should be considered for use in testing those specimens that are transported to the laboratory through the mail.

Cervix Uteri↗

PubMed1998

Inhibition of PCR in genital and urine specimens submitted for Chlamydia trachomatis testing.

We determined the frequency of PCR inhibition in genital and urine specimens submitted for Chlamydia trachomatis testing using the internal control DNA provided with the COBAS AMPLICOR C. trachomatis test and assessed methods to remove it. Inhibition occurred in 65 of 906 (7%) cervical swabs, 23 of 51 (45%) urethral swabs, and 2 of 175 (1.1%) urine samples. Overall, inhibition was eliminated in processed specimens after storage at 4 degrees C in 77 of 90 specimens (86%), freezing at -70 degrees C in 59 of 82 specimens (72%), storage at 4 degrees C followed by either 1:100 dilution in 37 of 43 specimens (86%) or 1:10 dilution in 42 of 47 specimens (89%), and phenol-chloroform extraction in 79 of 80 specimens (99%). No positive specimens were missed due to inhibition. We conclude that PCR inhibition is rare with urine specimens and infrequent with endocervical swabs but occurs frequently with urethral swabs. The frequency of PCR inhibition may be significantly reduced by methods which can be easily incorporated into the processing of specimens.

Automation↗

PubMed2001

Clinical Evaluation of the Gen-Probe amplified mycobacterium tuberculosis direct test for rapid detection of Mycobacterium tuberculosis in select nonrespiratory specimens.

The performance of the Amplified Mycobacterium Tuberculosis Direct Test (MTD; Gen-Probe, Inc., San Diego, Calif.) for rapid diagnosis of extrapulmonary tuberculosis was evaluated by testing 178 nonrespiratory specimens from 158 patients. Criteria for specimen inclusion were (i) a positive smear for acid-fast bacilli (n = 54) and (ii) the source if the smear was negative (tissue biopsies and aspirates and abscess material were tested; n = 124). Results were compared to those of mycobacterial culture; clinical history was reviewed when MTD and culture results disagreed. Forty-eight specimens (27.0%) were positive for mycobacteria, including 23 Mycobacterium tuberculosis complex specimens; of which 21 were smear positive. Twenty-five specimens were MTD positive; 20 of these grew M. tuberculosis complex. All of the five MTD-positive, M. tuberculosis complex culture-negative specimens were considered truly positive, based on review of the medical record. Of the three MTD-negative, M. tuberculosis complex culture-positive specimens, two contained inhibitory substances; one of the two was smear positive. Excluding the latter specimen from analysis, after chart review, the sensitivity, specificity, and positive and negative predictive values of the MTD were 92.6, 100, 100, and 98.7%, respectively, by specimen and 89.5, 100, 100, and 98.6% by patient. Given the few smear-negative samples from patients with extrapulmonary tuberculosis in our study, additional similar studies that include more smear-negative, M. tuberculosis complex culture-positive specimens to confirm our data are desirable.

Abscess↗

PubMed2003

Increased sectioning of pathologic specimens with ductal carcinoma in situ of the breast: are there clinical consequences?

To assess if there has been increased sectioning of pathologic specimens with ductal carcinoma in situ (DCIS), identify sources of this change, and consider the clinical consequences, pathologic data from patients who underwent initial excisional biopsies at our institution and were referred to the radiation oncology department with DCIS from 1992-2002 were retrospectively reviewed. One hundred forty-four of 480 patients with DCIS were eligible for review. Specimen size was recorded as length, to the nearest 0.1 cm, in 3 dimensions. Specimen volume was approximated by the product of the 3 dimensions of the specimen. The primary endpoint was the number of microscopic sections taken from gross specimens, corrected for specimen size. Other analysis included margin status, use of a previous stereotactic needle biopsy, and whether a subsequent repeat excision was performed. Over time, there was an increase in size of the excisional biopsy specimens (mean of 49 cm3 from 1992 to 1994 and 90 cm3 from 2001 to 2002; P = 0.045). Mean numbers of slides per centimeter of specimen were 2.5, 2.7, 3.9, and 5.8 for the intervals 1992-1994, 1995-1997, 1998-2000, and 2001-2002, respectively (P < 0.001 for 1992-1997 vs. 1998-2002). Adjusting for volume, the increase over time in the number of slides per specimen was statistically significant (parameter significance, P < 0.001). For a given volume, the number of slides increased approximately 9.1% per year, on average, during the study period. The positive margin rates were 52%, 46%, 23%, and 25% from 1992 to 1994, from 1995 to 1997, from 1998 to 2000, and from 2001 to 2002, respectively. The degree of sectioning, corrected for specimen length and volume, increased over time.

Biopsy↗

PubMedDate not supplied

Statistical comparison of aerosol-induced and spontaneous sputum specimens in the Tyler Asbestos Workers Program.

More than 10,000 sputum specimens, including both aerosol-induced and three-day pooled spontaneous specimens, were processed within a five-year period from a surveillance program of a cohort of 858 former asbestos workers and 188 controls. During the first two years, slides were prepared by the "pick and smear" method; thereafter, the Saccomanno technique was used. Each specimen was examined for both the degree of cellular atypia and the number of ferruginous bodies. Data analysis revealed that the number of ferruginous bodies in the spontaneous specimens showed a higher correlation with chest X rays and pulmonary function tests than did those in aerosol-induced specimens. Consequently, a study was undertaken to compare the results of all aerosol-induced and spontaneous cough specimens prepared by the pick and smear and Saccomanno methods. Matched pairs of specimens from the same individuals were also compared. More specimens with atypias were obtained from the spontaneous sputa using the Saccomanno technique. More ferruginous bodies were found in the aerosol-induced specimens using the pick and smear method. The pick and smear method was more effective for detecting ferruginous bodies in both induced and spontaneous specimens.

Aerosols↗

PubMed1996

Surgical pathology specimen identification and accessioning: A College of American Pathologists Q-Probes Study of 1 004 115 cases from 417 institutions.

OBJECTIVE: To examine and suggest improvements for deficiencies occurring in the specimen identification and accessioning process in the surgical pathology laboratory. DESIGN: Using the College of American Pathologists' and the Joint Commission for Accreditation of Healthcare Organizations' requirements as the standard, each laboratory was asked to prospectively document deficiencies in specimen identification and accessioning for 4 months, or until a maximum of 4000 cases or 400 deficiencies were accrued. PARTICIPANTS: Four hundred seventeen laboratories in the College of American Pathologists' voluntary quality improvement program, Q-Probes, participated in this study. RESULTS: Identification and accessioning deficiencies were found in 60 042 (6%) out of a total 1 004 115 cases accessioned (median deficiency rate of 3.4%). Errors related to specimen identification accounted for 9.6% of these deficiencies, discrepant or missing information items were present in 77%, and 3.6% involved specimen handling. The most common deficiency was "no clinical history or diagnosis present on the requisition slip," which represented 40% of all deficiencies. Deficiencies were most often detected by the person assigned to accessioning duties or by histology personnel. In 66% of cases, no action was taken to remedy the deficiency, but this varied dramatically according to the specific type of deficiency. An action was taken to remedy deficiencies in 69% of cases involving specimen identification errors, in 58% of specimen handling errors, and in 27% of cases with discrepant or missing information. Peer group stratifiers were associated with a lower deficiency rate. Laboratories with lower numbers (<15 000) of accessioned cases and laboratories with a formal written plan for the detection of errors in accessioning and specimen identification reported lower rates of deficiencies. Factors that correlated with a higher rate of deficiencies included submitting the specimen container and requisition slip in a unique secondary container (P<.005) and labeling the specimen container with only a patient's name or unique patient identification number (as opposed to both identifiers). CONCLUSIONS: The majority of deficiencies occurring in surgical pathology specimen identification and accessioning are related to missing or inaccurate clinical information. Deficiencies are detected in multiple locations, including areas not typically thought of as quality check points, such as transcription. A variable amount of effort occurs to rectify deficiencies; this effort is largely dependent on the type of deficiency involved. Finally, laboratories with a formal error detection plan had fewer deficiencies.

Humans↗

PubMed1989

Ethanol fixation of bladder irrigation specimens for flow cytometric analysis. A multiinstitutional study from the bladder cancer flow cytometry network.

Ethanol preservation of voided and catheterized urine has long been the standard for urinary cytologic study. In this report ethanol preservation of bladder irrigation specimens was evaluated for flow cytometric analysis in a multiinstitutional study requiring specimen transport. Specimens from ten patients obtained at one center were preserved for varying periods of time in 50% ethanol, then distributed by express mail to four other participating centers, up to 3000 miles distant. On receipt, from 1 to 3 weeks after collection, the samples were processed and examined by flow cytometric study using propidium iodide as the fluorochrome. Forty-six of the 50 (92%) analyzed specimens gave satisfactory histograms. In 41 of the 46 adequate samples (89%), an aneuploid peak in the alcohol preserved (propidium iodide stained) specimen correlated well with the fresh (acridine orange stained) specimen. However, there was variable loss of DNA stainability with a broadening of the coefficient of variation in some alcohol-preserved specimens and an increase in cellular debris so that measurements of DNA index and percent hyperdiploid cells were considered unreliable. The authors conclude that ethanol preservation of bladder irrigation specimens for short periods of time may be a feasible alternative when flow cytometric analysis cannot be carried out on fresh specimens, but that this is not optimal fixation for specimens that must be transported and further studies of other fixatives are recommended.

Aneuploidy↗

PubMed2005

Pineal gland lesions: a cytopathologic study of 20 specimens.

BACKGROUND: Pineal gland lesions are rare, with only a few cytologic descriptions occurring in the literature, according to the authors' knowledge. The current article describes the cytopathologic characteristics of 20 such lesions with discussion of differential diagnoses. METHODS: Cytologic material was obtained either by fine-needle aspiration biopsy (FNAB) under stearotactic radiologic guidance or by touch imprinting (TI) at the time of frozen sectioning. The 20 specimens include pineoblastoma (five specimens), pineocytoma (four specimens), astrocytoma (three specimens), germ cell tumor (three specimens), meningioma (one specimen), epidermoid cyst (three specimens), and pineal cyst (one specimen). Smears were stained with Diff-Quik and with Papanicolaou and hematoxylin and eosin stains. In selected specimens, immunoperoxidase (IPOX) stains were performed on cell block sections using synaptophysin, neuron-specific enolase, placental alkaline phosphatase, glial fibrillary acidic protein, leukocyte common antigen, cytokeratins, and human chorionic gonadotropin antibodies. RESULTS: Several cytomorphologic characteristics unique to each lesional category with occasional overlapping features were observed. The unique features included the following: small, hyperchromatic, round to oval cells with frequent rosetting (pineocytoma), with a few specimens in addition showing hypercellularity, crowding, mitoses, and necrosis (pineoblastoma); pleomorphic round cells in a fibrillary background (astrocytoma); large polygonal cells with prominent nucleoli and clear cytoplasm (germ cell tumor); spindled fibroblastic cells (meningioma); anucleate squames and mature squamous cells (epidermoid cyst); and small uniform polygonal cells (pineal cyst). When necessary, IPOX studies supported the morphologic diagnoses. CONCLUSIONS: FNAB and TI cytology were found to provide a rapid and reliable diagnosis of pineal lesions. This is particularly important when dealing with minute amounts of tissue material. Both techniques appeared to provide equally good cytomorphology on smears. IPOX studies played an important complementary role in difficult cases when performed on cell blocks.

Adolescent↗

PubMed2026

Diagnostic utility of high-risk HPV polymerase chain reaction-based testing in head and neck FNA specimens with indeterminate cytomorphology.

BACKGROUND: Fine-needle aspiration (FNA) is critical in the initial diagnosis of many high-risk human papillomavirus (HR-HPV)-associated, metastatic oropharyngeal squamous cell carcinomas. Updated guidelines recommend HR-HPV-specific polymerase chain reaction (PCR) analysis over p16 immunohistochemistry on FNA specimens because p16 performs poorly on cytology material. PCR-based assays on liquid cytology material have demonstrated excellent analytic performance; however, the diagnostic utility of a positive HR-HPV PCR result in specimens with indeterminate cytomorphology remains uncharacterized. METHODS: The authors retrospectively identified 279 head and neck FNA specimens that had paired HR-HPV PCR testing on residual liquid cytology material over a 5-year period. The positive predictive value for histopathologically confirmed squamous cell carcinoma on surgical follow-up was calculated within each cytologic interpretive category. RESULTS: The HR-HPV PCR results were positive in 50.2% of specimens, negative in 40.9%, and indeterminate in 9.0%. The HR-HPV positivity rate ranged from 0% in specimens categorized as negative for malignancy to 57.3% in cytologically positive specimens, with 19.0%, 41.2%, and 50.0% positivity in the atypical, suspicious, and nondiagnostic categories, respectively. Among cytologically indeterminate specimens with positive HR-HPV PCR results (n = 14), the positive predictive value was 100% (95% confidence interval, 78.5%-100.0%). Blinded slide review additionally identified 15 cytologically positive specimens in which the definitive malignant interpretation depended substantially on HR-HPV positivity; all 15 were confirmed as squamous cell carcinoma. CONCLUSIONS: A positive HR-HPV PCR result on liquid cytology material carries a positive predictive value of 100% for malignancy in cytologically indeterminate head and neck FNA specimens. These findings support integrating HR-HPV PCR analysis into routine cytologic interpretation with the potential to upgrade some indeterminate specimens to malignant when HR-HPV is detected, expediting definitive treatment and sparing patients additional, invasive sampling.

Humans↗

PubMed2006

Utility of reflex Gomori methenamine silver staining for Pneumocystis jirovecii on bronchoalveolar lavage cytologic specimens: a review.

Pneumocystis jiroveci (Pj; formerly Pneumocystis carinii) is an opportunistic pathogen causing life-threatening pneumonia (Pneumocystis pneumonia) in immunosuppressed individuals. Its diagnosis is dependent on identification in bronchoalveolar lavage (BAL) specimens. Gomori's methenamine silver nitrate (GMS) stain has been advocated to highlight the organisms in BAL specimens. This study was performed to determine the utility of reflex GMS staining on all BAL specimens for identifying Pj.All BAL specimens from years 2000 to 2004 were processed as cytospins and stained with Papanicolaou (Pap) and GMS stains. A total of 2,984 BAL specimens were identified. A total of 116 (3.9% of total BAL) BAL specimens were diagnostic of Pj. The diagnostic specimens were grouped as follows: 103 (88.8% of total positive cases) Pj identified with both Pap and GMS staining; 11 (9.5% of total positive cases) Pj identified only with Pap staining; and 2 (1.7% of total positive cases) Pj identified only with GMS staining. In conclusion, the prevalence of Pj in BAL specimens is 3.9%, which can be attributed to improved management of immunocompromised patients. Performing reflex GMS staining on all BAL specimens does not improve the diagnostic identification of Pj since the majority (98.3%) of diagnoses can be rendered on Pap stained slides. A cost analysis for GMS staining on 2,879 GMS-negative BAL specimens was estimated at $143,950. Thus, from diagnostic and cost benefit perspectives, GMS staining can be recommended only on cases where Pap stain is negative, and the clinical presentation is consistent with Pneumocystis pneumonia.

Adolescent↗

PubMed1992

The detection in urine specimens of IgG and IgM antibodies to hepatitis A and hepatitis B core antigens.

The use of urine as a noninvasive specimen for the diagnosis of hepatitis A (HAV) and hepatitis B (HBV) virus infections was investigated. Specimens of urine were collected at the same time as blood or saliva specimens, or singly in cases of previously serologically confirmed recent infection. The specimens were tested for IgG and IgM anti-HAV and anti-HBc by immunoglobulin class-specific capture radioimmunoassays (GACRIA and MACRIA). On the basis of assays on urine specimens it was possible to distinguish between individuals who were susceptible or immune to HAV or who had recently been infected with HAV. Using assays on 327 corresponding saliva specimens as reference tests, the observed sensitivity and specificity of tests on urine specimens by anti-HAV GACRIA were 98.9% and 99.1%, respectively, and by anti-HAV MACRIA were 95.8% and 99.6%, respectively. IgM and IgG anti-HBc were detected readily in the urine of 35 acute or recent cases of hepatitis B but were not found in the urine of seronegative individuals. Of the urine specimens from 52 individuals who were HBsAg carriers or who had had long past HBV infections, 49 contained detectable IgG anti-HBc. Of urine specimens from 42 HBsAg carriers, 11 contained raised IgM anti-HBc levels. Urine, which is a convenient specimen to collect, can be used to study outbreaks of hepatitis A, to ascertain the HAV immune status of individuals, to differentiate hepatitis A from hepatitis B, and to identify individuals who have been naturally exposed to HBV.

Hepatitis A↗

PubMed2006

The significance of the P504S expression pattern of high-grade prostatic intraepithelial neoplasia (HGPIN) with and without adenocarcinoma of the prostate in biopsy and radical prostatectomy specimens.

Diagnosis of prostatic adenocarcinoma is usually not difficult in biopsy specimens. Problems may occur in biopsy specimens, containing only a few suspicious lesions. Recently, P504S has been tested as a new marker for prostatic carcinoma. When over-expressed in atypical glands without basal cells, it establishes the diagnosis of prostatic carcinoma. We analysed the staining intensity of P504S in 208 biopsy specimens from prostates (1) with adenocarcinoma (n=132), (2) with high-grade prostatic intraepithelial neoplasia (HGPIN) with adenocarcinoma (n=36), (3) with HGPIN alone (n=40) and in radical prostatectomy specimens with HGPIN adjacent to (n=54) or distant from adenocarcinoma (n=64). P504S expression was negative to weakly positive in biopsy specimens showing HGPIN without carcinoma and weakly positive in radical prostatectomy specimens revealing HGPIN distant from adenocarcinoma. In biopsy specimens with a combination of HGPIN and adenocarcinoma and in radical prostatectomy specimens with HGPIN adjacent to adenocarcinoma, P504S was strongly expressed. The same findings were made in radical prostatectomy specimens containing adenocarcinoma and HGPIN adjacent to or distant from adenocarcinoma and in preoperative biopsies revealing adenocarcinoma and HGPIN. These results suggest that moderate to strong P504S expression in HGPIN of biopsy specimens is indicative of an associated adenocarcinoma and may be helpful in the choice of therapy.

Adenocarcinoma↗

PubMed2004

Application of a polymerase chain reaction enzyme immunoassay in peripheral whole blood and serum specimens for diagnosis of acute human brucellosis.

A simple polymerase chain reaction-enzyme immunoassay (PCR-EIA) was employed for the rapid laboratory diagnosis of human brucellosis directly from peripheral blood. Whole blood and serum specimens were collected from 243 patients with acute brucellosis as determined by blood culture, serological tests, and the patients' clinical characteristics and from a control group of 50 healthy individuals. Diagnosis of brucellosis was established in 179 cases by isolation of Brucella spp. in blood culture and in 64 cases by clinical signs and serological investigation. Following the amplification of a 223-bp sequence of a gene that codes for the synthesis of an immunogenic membrane protein specific for the Brucella genus, the amplified product was detected in a microtiter plate by hybridization. Two hundred forty-one of the 243 patients tested had detectable Brucella DNA in either whole blood or serum specimens: 149 (61.3%) patients were positive in both whole blood and serum specimens, 43 (17.7%) were positive in serum specimens only, and 49 (20.2%) were positive in whole blood specimens only. The diagnostic specificity of the PCR-EIA assay for both specimen categories was 100%, while the sensitivity was 81.5% for whole blood specimens, 79% for serum specimens, and 99.2% for whole blood and serum specimens combined. The results suggest that the detection of Brucella DNA in whole blood and serum specimens by PCR-EIA assay is a sensitive and specific method that could assist the rapid and accurate diagnosis of acute human brucellosis.

Acute Disease↗

PubMed2026

Clinical performance of the Abbott RealTime Mycobacterium tuberculosis (MTB) PCR on bronchoscopic specimens for diagnosing pulmonary tuberculosis.

PURPOSE: We evaluated the performance of the Abbott RealTime Mycobacterium tuberculosis (MTB) PCR (RT MTB) on bronchoscopic specimens using conventional culture as the reference standard in a low-Tuberculosis (TB) prevalence setting. METHODS: A total of 6,988 specimens (4,682 bronchial aspirates [BAS] and 2,306 bronchoalveolar lavages [BAL]) from 4,118 patients with suspected pulmonary TB were included. When BAS and BAL specimens from the same bronchoscopy procedure were available, these were mixed 1:1 prior to culture inoculation and PCR testing. Following processing, specimens were inoculated into a Löwenstein-Jensen and a Bactec MGIT 960 tube and incubated at 37 °C for 3 months and at 35 °C for 8 weeks, respectively. RT MTB was performed as indicated by the manufacturer. RT MTB targets the insertion sequence IS6110 and the protein antigen B (PAB) gene, both highly conserved within the Mycobacterium tuberculosis complex. Whole genome Next generation sequencing of clinical MTBC isolates was performed when indicated. RESULTS: Among the 104 culture-positive specimens, 84 (1.2%) were detected by PCR. Additionally, 16 specimens (0.3% of all samples), from 16 patients, were PCR-positive despite negative culture results. Conversely, 20 specimens (0.4% of all samples), from 19 patients, were culture-positive but not detected by PCR. No significant differences were found between PCR-positive and PCR-negative specimens with respect to the number of IS6110 copies per isolate or PAB gene sequences (P = 0.69). Finally, there were 4,683 specimens (97.4%) from the remaining 4,014 patients tested PCR-negative/Culture-negative. Following the resolution of discrepancies based on clinical grounds the sensitivity and specificity of RT MTB were 83.9% (CI 95%, 76.0-90.0) and 99.9% (CI 95%, 99.9-99.9), respectively. These results exceed the minimum performance requirements defined in the WHO Target Product Profiles for molecular TB diagnostics. Although RT MTB is not a point-of-care test but rather a moderate-complexity automated NAAT, it is recommended by WHO as part of the Abbott RealTime MTB/MTB RIF-INH testing algorithm, in which MTBC detection by RT MTB is followed by reflex testing with the MTB RIF/INH assay for detection of rifampicin and isoniazid resistance. CONCLUSION: RT MTB shows a good performance on bronchoscopic specimens.

Mycobacterium tuberculosis↗

PubMed1989

Compressive axial strain distributions in cancellous bone specimens.

The compressive axial strain distribution in cylindrical trabecular bone specimens was studied using digitized images of the specimen surface. Specimens were tested with strain rate 0.00015 s-1. Images were taken at 0, 1, 2, 3, 4, 6, 8 and 10% strain. Using an optical illusion of movement by rapidly changing succeeding images, failures were classified as transverse (33%) or oblique collapses (67%). The location of failure was not determined by the specimen density gradient. Local axial strain in the distal, intermediate and proximal third was measured throughout the compression in the transversely failing specimens, whereas local strain in the obliquely failing specimens was measured in the pre-failure phase only. Axial strain inhomogeneity was observed in the pre-failure as well as in the post-failure phase. In the pre-failure phase the intermediate third was strained significantly less than the thirds near the ends. In the post-failure phase specimen strain occurred solely in the collapsed part. Ultimate strain of the transversely failing specimens was 2.5% and ultimate strain of the failing third was 3.7%. At failure less than 1% strain was observed in the intermediate third and at 10% specimen strain 1.5% local strain was found in the intermediate third. The results indicate unreliability of conventional stiffness and strain measurements in trabecular bone specimens probably due to lack of trabecular constraint at the end surfaces. Conventional measurements tend to underestimate stiffness and, by giving an average value of strain in spite of considerable strain inhomogeneity, to underestimate failure strain.

Bone Density↗

PubMed2004

Comparison of the BDProbeTec ET system with the roche COBAS AMPLICOR System for detection of Mycobacterium tuberculosis complex in the respiratory and pleural fluid specimens.

The new BDProbeTec ET System (BDET; BD Biosciences, Sparks, MD) was compared with the Roche COBAS AMPLICOR System (CAS) and culture for Mycobacterium tuberculosis (MTB). A total of 253 specimens (152 respiratory and 101 pleural fluid specimens) collected from 240 patients were tested in parallel with the 3 assays. After resolving the discrepancies, the sensitivity, specificity, and positive and negative predictive values of the BDET for detecting MTB was 76.9%, 93.7%, 71.4%, and 95.2% for the respiratory specimens and 88.9%, 92.4%, 53.3%, and 98.8% for the pleural fluid specimens, respectively. The corresponding values of the CAS were 69.2%, 100%, 100%, and 94% for the respiratory specimens and 33.3%, 100%, 100%, and 93.9% for the pleural fluid specimens, respectively. No significant differences in sensitivities were observed between the results of both assays for the respiratory specimens. However, statistically significant differences in sensitivities were found between the BDET and CAS for the pleural fluid specimens (P =.02). Although the BDET was less specific than the CAS (P =.007), the BDET has an excellent sensitivity for detecting MTB in the pleural fluid specimens. Considering the low sensitivity of other available tests, the BDET can be a useful diagnostic tool for excluding MTB, particularly in the pleural fluid specimens.

Bacteriological Techniques↗

PubMed1998

Effect of blood on rapid urease testing of gastric mucosal biopsy specimens.

BACKGROUND: The effect of blood on rapid urease tests is uncertain. We assessed the effect of soaking gastric biopsy specimens in blood on the results of both agar gel (CLOtest) and strip (Pyloritek) rapid urease tests. METHODS: One hundred patients undergoing endoscopy had four adjacent biopsy specimens taken from normal appearing mucosa in the antrum. Two biopsies were soaked in blood for 1 minute; one specimen was placed on a CLOtest and one on a Pyloritek. The other two biopsy specimens were placed on CLOtest and Pyloritek without soaking in blood. The same process was performed with four adjacent biopsy specimens from the gastric body. CLOtests were read at 1, 4, and 24 hours; Pyloritek results were read at 1 hour. RESULTS: The number of positive tests for the blood-soaked and standard biopsy specimens were comparable at all times for both rapid urease tests. Discordant results between the blood-soaked and standard specimens were seen in 17 of 400 test comparisons (4%): in 8 of these only the blood-soaked specimen was positive, and in 9 only the standard specimen was positive. CONCLUSIONS: "Contamination" of biopsy specimens with blood does not alter rapid urease test results.

Biopsy↗