Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “SPECIMENS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 613 records · Page 34Linked to original sources
PubMed1990

Binding of the blood group-reactive lectins to human adult kidney specimens.

The binding of a panel of blood group-reactive lectins to frozen sections of human kidney was studied with a special emphasis on reactivity with endothelia and basement membranes. The blood group A-reactive lectins, all specific for alpha-D-N-acetylgalactosamine (GalNAc), Helix aspersa (HAA), Helix pomatia (HPA), and Griffonia simplicifolia I-A4 (GSA-I-A4) agglutinins bound to the endothelium in specimens with blood groups A and AB. In other samples, these lectins reacted predominantly with tubular basement membranes, as well as with certain tubules. Both Dolichos biflorus (DBA) and Vicia villosa agglutinins (VVA), reported to react with blood group A1 substance, failed to reveal endothelia in most specimens, but bound differently to tubules in all blood groups. The blood group B-reactive lectins, specific for alpha-D-galactose (alpha-Gal) or GalNAc, respectively, GSA-I-B4 and Sophora japonica agglutinin (SJA), bound to the endothelia in specimens from blood group B or AB and in other specimens bound only to certain tubules. Among the blood group O-reactive lectins, specific for alpha-L-fucose (Fuc), Ulex europaeus I agglutinin (UEA-I) conjugates, but not other lectins with a similar nominal specificity, bound strongly to endothelia in specimens with blood group O. The UEA-I conjugates bound distinctly more faintly to endothelia in specimens of other blood groups. The present results indicate that lectins, binding to defined blood group determinants, react with endothelia in specimens of the respective blood group status. Furthermore, they suggest that basement membranes and some tubules in the human kidney show a distinct heterogeneity in their expression of saccharide residues, related to their blood group status.

Adult↗
PubMed2003

Epithelial lesions in prophylactic mastectomy specimens from women with BRCA mutations.

BACKGROUND: It has been suggested that BRCA-associated breast carcinoma may often lack a detectable preinvasive phase. To investigate this hypothesis, the authors compared the prevalence of histopathologic lesions in prophylactic mastectomy (PM) specimens from women with BRCA mutations and in mastectomy specimens obtained at autopsy from an age and race-matched comparison group without a known cancer predisposition. METHODS: All specimens from women with a deleterious BRCA1 or BRCA2 mutation who participated in an ongoing follow-up study and underwent PM at Memorial Sloan-Kettering Cancer Center between November 1, 1987 and May 31, 2001 were reviewed. For each case, breast tissue from two age and race-matched women without a known cancer predisposition was also reviewed. The prevalence of benign, premalignant, and cancerous lesions was compared. RESULTS: Mastectomy specimens from 24 cases and 48 comparison subjects were reviewed. Ductal carcinoma in situ (DCIS), atypical ductal hyperplasia (ADH), and atypical lobular hyperplasia (ALH) were all more common in PM specimens from women with BRCA mutations than in those from the comparison group. The odds ratio for the detection of any high-risk lesion (DCIS, lobular carcinoma in situ, ADH, or ALH) in specimens from BRCA mutation carriers was 12.7 (95% confidence interval, 3.1-52.4; P < 0.001). CONCLUSIONS: Lesions associated with an increased risk of subsequent malignancy are more common in PM specimens from women with BRCA mutations than in breast tissue obtained at autopsy from unaffected women without a known predisposition. This finding suggests that hereditary breast carcinoma has a preinvasive phase that may be detectable with aggressive surveillance.

Adult↗
PubMed2004

Pathologic evaluation of radical cystectomy specimens: a cooperative group report.

BACKGROUND: The authors evaluated the pathology of radical cystectomy and pelvic lymph node specimens from patients with bladder carcinoma who were enrolled in a cooperative group trial. Their objective was to determine whether current practices conform to suggested pathology practice guidelines for reporting on radical cystectomy and pelvic lymph node specimens. METHODS: Overall, 268 patients underwent radical cystectomy with pelvic lymph node dissection over 11 years in a total of 109 diverse geographic locations and types of institutions. Institutions included 50 community hospitals, 36 academic hospitals, and 23 Veterans Administration (VA)/military hospitals, which evaluated 84, 137, and 47 patients, respectively. The quality of pathology examination was assessed based on the original pathology reports of specimens that were submitted according to published practice guidelines. RESULTS: Among all types of institutions, pathologic evaluation of radical cystectomy specimens generally was complete for tumor histology, grade, size, location, pathologic stage, lymph node status, prostate involvement, and associated mucosal abnormalities, including ureters and urethra. Perivesical fat (soft tissue) margins were not recorded in 10% of specimens, and 18% of patients did not mention either the presence or the number of lymph nodes. These deficiencies were observed primarily at community and VA hospitals. CONCLUSIONS: The overall quality of pathologic examination of radical cystectomy specimens is high. Better reporting of soft tissue margin status and pelvic lymph node counts is needed to achieve compliance with the standards published by evolving practice protocols. Standardized pathologic evaluation and reporting of radical cystectomy specimens will optimize important prognostic information and foster better communication between the pathologist, surgeon, and interested oncologists to benefit patients.

Aged↗
PubMed2005

The utility of interphase fluorescence in situ hybridization for the detection of the translocation t(11;14)(q13;q32) in the diagnosis of mantle cell lymphoma on fine-needle aspiration specimens.

BACKGROUND: Mantle cell lymphoma can be difficult to differentiate cytologically from other small cell non-Hodgkin lymphomas. Nevertheless, the distinction is important, because mantle cell lymphoma is more aggressive than other small cell non-Hodgkin lymphomas. The purpose of this study was to determine whether fluorescence in situ hybridization (FISH) is helpful in diagnosing mantle cell lymphoma on fine-needle aspiration (FNA) specimens by detecting the t(11;14)(q13;q32) translocation that is characteristic of this tumor. METHODS: Fifty-five lymph node FNA specimens from 53 patients were analyzed using FISH. A 2-color FISH assay that employed probes at the 14q32 (immunoglobulin H) and 11q13 (dual-colored, directly labeled cyclin D1) loci was used. The number of single-fusion and double-fusion signals in 200 cells was counted. If > or = 14% single-fusion signals or > or = 1.5% double-fusion signals or both were present, then the sample was considered FISH positive. The findings were correlated with the cytologic, histologic, and immunophenotypic findings in each specimen. RESULTS: Of the 55 cytology specimens, 17 were mantle cell lymphomas, and 38 were nonmantle cell lymphomas, including 16 small lymphocytic lymphomas (9 of 16 in an accelerated phase), 5 large cell lymphomas, 5 follicular lymphomas, 7 transformed large cell lymphomas (Richter syndrome), 3 atypical lymphoid proliferations, and 2 low-grade B-cell lymphomas. All 17 mantle cell lymphomas were positive by FISH. In addition, there were six small lymphocytic lymphomas (two in accelerated phase), one transformed large cell lymphoma, and one large cell lymphoma of follicular origin positive by FISH. The mean number of single-fusion and double-fusion signals, respectively, was 36 and 33 in mantle cell lymphoma specimens and 19 and 3 in positive nonmantle cell lymphoma specimens. CONCLUSIONS: The detection of the t(11;14)(q13;q32) translocation by FISH analysis was helpful in diagnosing mantle cell lymphoma on FNA specimens. Double-fusion signals were more specific for mantle cell lymphoma than single-fusion signals. In rare instances, other non-Hodgkin lymphomas also showed increased numbers of single-fusion signals that were not necessarily indicative of the t(11;14)(q13;q32) translocation. Therefore, in an initial diagnosis of mantle cell lymphoma, significant numbers of double-fusion FISH signals should be identified and interpreted in conjunction with the cytologic and immunologic studies.

Biopsy, Fine-Needle↗
PubMed1994

Bladder irrigation specimens assayed by fluorescence in situ hybridization to interphase nuclei.

Bladder irrigation specimens provide a sampling of the entire bladder urothelium and are the most practical sample for longitudinally monitoring patients. This study presents cross-sectional fluorescence in situ hybridization (FISH) analyses with correlated DNA cytometry data on 76 patients monitored for recurrent bladder tumors. FISH probes complementary to centromeric satellite sequences for chromosomes 1, 7, 9, 11, 15, and 17 were used. Aberrations in copy number were observed for chromosomes 1, 7, 11, and 17 principally in patients with aneuploid tumors. Monosomy of chromosome 9 was observed in 39% of the diploid and 31% of the specimens with high hyperdiploid fraction. Significantly, 24% of patients with a history of bladder cancer but with no clinical evidence of disease exhibited monosomy of chromosome 9. This suggests a persistent and significantly large population of abnormal cells in the absence of clinical evidence of disease. Loss of chromosome 9 relative to DNA ploidy was observed in 24% of patients with no evidence of disease, in 59% of patients with tumor, and in 79% of patients with histologically confirmed transitional cell carcinoma, grades 1-3. Loss of chromosome 15 was also observed in a large percentage of patients. Loss of chromosome 15 was observed in 41% of specimens from patients in whom no tumor was seen, in 38% of specimens from patients with tumor, and in 67% of specimens from patients with histologically confirmed transitional cell carcinoma. Results of this study document the use of bladder irrigation specimens as a specimen source for FISH analyses.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Diagnosis of Pneumocystis carinii pneumonia by cytologic evaluation of Papanicolaou-stained bronchial specimens.

To evaluate the sensitivity and specificity of diagnosing Pneumocystis carinii pneumonia (PCP) by Papanicolaou-stained bronchial brushing and wash/lavage specimens obtained by fiberoptic bronchoscopy, the cytologic preparations and clinical records from 58 immunocompromised patients were reviewed. Bronchial brushings and wash/lavage specimens were examined using methenamine silver (Grocott) and Papanicolaou stains. Pneumocystis carinii pneumonia was recognized with Papanicolaou stain by identifying distinctive alveolar casts, which frequently contained collections of encysted sporozoites. Thirty cases of PCP were identified, and Grocott-stained bronchial wash/lavage specimens were positive in 29 instances (97%). Grocott staining of the transbronchial biopsy was positive for PCP in 18 of 22 specimens (82%). Bronchial brushings were insensitive, yielding a positive specimen in only 30% of cases of PCP. Alveolar casts of PCP were identified by Papanicolaou-stained slides of wash/lavage specimens in 83% of cases of Pneumocystis pneumonia. These proteinaceous alveolar casts were not seen in other pulmonary disorders. Encysted sporozoites were found in 56% of cases in which Papanicolaou-stained alveolar casts were identified. We conclude that the diagnosis of PCP can be made rapidly and reliably on the Papanicolaou-stained bronchial wash/lavage or bronchial brush specimens by detecting the characteristic alveolar casts, which contain P. carinii-encysted sporozoites. The presence of encysted sporozoites within alveolar casts is pathognomonic for PCP, and methenamine silver stains can be eliminated in those cases in which encysted sporozoites are identified.

Bronchoalveolar Lavage Fluid↗
PubMed1994

Use of a compact sandwich specimen to evaluate fracture toughness and interfacial bonding of bone.

The objective of the present study was to develop a reliable and statistically valid test to measure the fracture toughness of small specimens of bone, and by extension, prosthetic materials, using a compact sandwich specimen. Samples of bone were sandwiched between holders of a different material and using this specimen configuration a new technique was developed to test the fracture toughness of the bone interlayer. The effects of different specimens sizes and holder materials were investigated empirically. Using finite element analysis a correction factor was determined to account for the finite thickness of the interlayer and the analytical solutions governing the test specimen were accordingly modified. Bulk compact tension specimens of bone were tested for comparison. Both wet and dry bone were evaluated and the fracture surface morphology characterized using scanning electron microscopy. The results indicate no statistically significant differences between the fracture toughness values obtained from the compact tension and sandwich specimens. The application of this technique to the testing of interfacial bonding between bone and biomaterials is discussed.

Aluminum↗
PubMed1986

A combination of four cell types for rapid detection of enteroviruses in clinical specimens.

Isolation in cell culture is currently the most sensitive and reliable way to demonstrate enterovirus (EV) in clinical specimens. During July-October 1982 and 1983, we studied the impact of adding two new cell lines, Buffalo green monkey kidney (BGM) and human rhabdomyosarcoma (RD), to the more traditional cell combination used for EV isolation, human embryonic lung (HEL) and primary cynomolgus monkey kidney (CMK) cells; 2,558 specimens were studied: 632 fecal, 677 respiratory, 537 CSF, and 712 blood. An EV was isolated from 417 (16%); of these, 77 (18%) were positive only in BGM or RD; 35% (146/417) of the specimens were positive in BGM, RD, or both, at least one day earlier than in the traditional cells. BGM cells were helpful in isolation of group B coxsackieviruses (CB): 99% of 121 positive specimens were detected in BGM vs 73% in CMK and 23% in HEL; 72% of the CB isolates were detected by day 2 in BGM vs 48% in CMK and 0% in HEL. RD cells were helpful in the isolation of echoviruses: 59% of the 189 positive specimens were detected in RD vs 67% in HEL and 58% in CMK. RD was the only positive cell type in 28/189 (15%) positive specimens; 31% of the echovirus isolates were detected by day 2 in RD, vs 20% in HEL and 19% in CMK. Using the cell types described, we provided the clinician with results in 42% of the EV-positive specimens by day 2 after inoculation and in 61% by day 4.

Animals↗
PubMed1990

Flow cytometric DNA content analysis in primary lung cancer: comparison of results from fresh and paraffin-embedded specimens.

Tumor DNA content was determined by flow cytometry in 24 surgically resected specimens from patients with primary lung cancer to compare results from fresh and paraffin-embedded specimens. We found a good correlation in DNA indices between fresh and paraffin-embedded specimens (r = .978), although one tumor with DNA near-diploidy was mistaken as DNA diploid in paraffin-embedded specimens. In the measurements of paraffin-embedded specimens, eight of 24 tumors were DNA multiploid and showed DNA content heterogeneity. These results indicate that DNA content analysis of paraffin-embedded specimens is helpful because it makes it easy to analyze multiple specimens from different parts of the tumor.

Adenocarcinoma↗
PubMed1997

Pathological changes in yearly protocol liver biopsy specimens from healthy pediatric liver recipients.

Many centers perform biopsies on transplanted livers annually to assess allograft function because serum biochemical tests do not always correlate with histological findings. Although criteria exist for diagnosing acute cellular rejection, no similar criteria exist to describe the histopathological changes observed in the "normal" liver of an immunosuppressed but healthy child. The purpose of this study was to define the histopathological changes in the allografted livers of healthy children who have undergone transplantation and to evaluate them during long-term follow-up. One hundred fifty-eight yearly protocol liver biopsy specimens of 54 children who received transplants between January 1988 and March 1996 and at least 1 year of follow-up were reviewed, and the biopsy findings were correlated with those of serum tests of liver function performed concomitantly. Thirty-three biopsy specimens were excluded because serum transaminase levels were abnormal, the biopsy specimen was abnormal and diagnostic for a specific lesion, or follow-up showed progression of a specific disease process. In addition, time zero biopsy specimens from 21 of the 54 children were available for comparison. In the protocol biopsy specimens, portal and/or parenchymal mononuclear inflammatory infiltrates were frequent findings (48% and 25%, respectively). Other less common features were mild fibrosis (8%) and focal pericholangitis (6%). Findings in both protocol and time zero biopsy specimens included minimal to mild bile ductular proliferation (15% and 9.5%, respectively) and rare hepatocyte necrosis (1.6% and 5%). No yearly protocol biopsy specimens resulted in any patient benefit. Transplanted livers in immunosuppressed children who are clinically healthy and have normal transaminase levels commonly show histological changes consisting of scattered, mild to moderate, portal and/or parenchymal mononuclear infiltrates that are clinically insignificant. Yearly protocol biopsies in healthy pediatric recipients have been abandoned by the investigators after 3 years of follow-up.

Biopsy↗
PubMed2005

Obtaining fresh prostate cancer tissue for research: a novel biopsy needle and sampling technique for radical prostatectomy specimens.

BACKGROUND: Fresh or fresh-frozen tissue samples are preferred for molecular profiling as formalin fixation degrades intracellular nucleic acids. Radical prostatectomy (RP) specimens are a valuable source of prostate cancer tissue, but the reliance on whole-organ pathological processing for prognostication limits sampling opportunities. Few studies have addressed specific harvesting techniques using prostatectomy specimens. MATERIALS AND METHODS: Ex vivo biopsies were performed on 23 consecutive fresh RP specimens using a purpose-designed needle. A standard sextant approach was used with an additional lateral biopsy on each side. Cores from each lobe were snap-frozen together and sections assessed by a pathologist blinded to the RP and pre-operative biopsy pathology. Comparison with pre-operative biopsies was performed using the t-test and chi(2) statistical tests. Eleven randomly selected RP specimens were further evaluated for the effects of needle tracks and margin perforation. RESULTS: Cancer was detected in 19 of 23 specimens, giving a sensitivity of 83.6%. The average tumor involvement was 28.3% per section compared with 15.6% for pre-operative biopsies (P < 0.02). There was no statistically significant difference between the groups for either Gleason sum score concordance or tumor location concordance. In 3 of 11 cases, needle margin perforation was identified; in none of the cases did it compromise pathological assessment, although in one case a deeper block resection was required. CONCLUSIONS: Ex vivo biopsy is a useful technique for retrieving fresh tissue whilst preserving organ morphology in RP specimens. The purpose-designed needle and harvesting technique provide good yields of cancer tissue from a high proportion of sampled prostatectomy specimens.

Biopsy, Needle↗
PubMedDate not supplied

An improved specimen loader for cryo-scanning electron microscopy.

Cryo-electron microscopy of cryofixed samples is a well-established and accepted technique for imaging liquid-containing specimens without removing water and other volatile components. There are many steps between cryofixation and cryo-observation in the microscope, during which the sample and sample holder need to be handled. One such major step is the loading of the specimen onto the sample holder and the fixing of the sample holder onto the transfer mechanism. During this handling, the specimen is often exposed (mostly inadvertently) to moisture in the atmosphere, which results in frost deposition. The new specimen loader described here is designed to overcome the traditional tedious handling and to achieve ease in specimen loading. The modifications made are mainly towards allowing movement of the liquid freon cup, eliminating the need for a lock-screw and improving the shape of the stage holder, which makes the mounting of the specimen holder easy, thereby permitting smooth specimen loading without too much handling and with consequent reduced frost deposition.

Cryoelectron Microscopy↗
PubMed2001

Comparison of oligosaccharides in milk specimens from humans and twelve other species.

Human milk contains large amounts of many oligosaccharides, most of which are fucosylated; several inhibit pathogenic bacteria, viruses, and toxins that cause disease in humans. Although bovine milk is known to have much less and many fewer types of oligosaccharides, no studies heretofore have indicated whether the amount or complexity of human milk oligosaccharides is unique to our species. Toward this end, a comparison was made of the major individual oligosaccharides in milk specimens from a variety of species, including the great apes. The neutral compounds, which represent the bulk of oligosaccharides in human milk, were isolated, perbenzoylated, resolved by high performance liquid chromatography (HPLC), and detected at 229nm. Ambiguous structures were determined by mass spectrometry. All milk specimens contained lactose, although levels were quite low in bear and kangaroo milk. The types of oligosaccharides in milk specimens from the primates resembled those of human milk, but the amounts, especially of the larger molecules, were markedly lower. The relative amounts of oligosaccharides in the bonobo changed over the course of lactation, as they do in humans. Marine mammals generally had few oligosaccharides in their milk other than 2'-fucosyllactose. Grizzly and black bear milk specimens contained a wide range of oligosaccharides, many of which had novel, fucosylated structures. Milk specimens from humans, bears, and marsupials had the greatest quantity of, and the most complex, neutral oligosaccharides. Although human milk contained more oligosaccharide than did milk specimens from the other species studied, the presence of appreciable amounts of complex oligosaccharides was not unique to humans. This finding suggests that in animal milk specimens, as in human milk, neutral fucosylated oligosaccharides potentially offer protection from pathogens to offspring with immature immune systems.

Animals↗
PubMed1993

Surgical pathology of chronic epileptic seizure disorders: experience with 63 specimens from extratemporal corticectomies, lobectomies and functional hemispherectomies.

The surgical treatment of chronic pharmacoresistant epilepsies is increasing rapidly. Although several studies have reported on histopathological findings in temporal lobe epilepsy, little is known about the surgical pathology of other seizure disorders. Here we report the histopathological findings in 63 consecutive surgical specimens of patients who were operated for chronic pharmacoresistant epileptic seizures other than temporal lobe epilepsy (37 corticectomies, 19 functional hemispherectomies, 5 lobectomies, 1 multilobectomy, and 1 frontal lobe deafferentiation combined with a temporal lobectomy). There were structural lesions in 85.7% of the specimens. In 16 cases (25.4%) the predominant lesions were malformative (focal glioneuronal hamartias and hamartomas, vascular malformations, abundant ectopic neurons in the white matter, microgyria, and arachnoid cyst). Lesions indicating pre- or perinatal necrosis such as porencephaly, ulegyria, and congenital hemiatrophy were present in 7 cases (11.1%). Twelve specimens (19.0%) contained low-grade neoplasms (7 gangliogliomas, 3 astrocytomas, 1 oligodendroglioma and 1 oligoastrocytoma). There were 3 cases of Rasmussen encephalitis, 1 specimen with atrophy and gliosis due to previous herpetic encephalitis and 1 case with an old abscess wall. Posttraumatic or postoperative changes were the predominant finding in 7 specimens (11.1%). In 7 patients there were only nonspecific changes such as cortical atrophy and gliosis or old hemorrhage. No structural alterations were identified in 9 specimens (14.3%). The findings suggest that the structural lesions observed in the great majority of the specimens were closely related to the pathogenesis of intractable seizures.

Adolescent↗
PubMed1985

Differential immunostaining for substance P in Huntington's diseased and normal spinal cord: significance of serial (optimal, supra-optimal and end-point) dilutions of primary anti-serum in comparing biological specimens.

Using immunocytochemistry (ICC), the number of immunoreaction products (IRPs) visualized for the peptide substance P (SP) appears reduced within the human spinal cord (also substantia nigra) taken at autopsy from cases diagnosed with Huntington's disease (HD) compared with the non-HD cases (Vacca 1983). The reductions of SR-IRPs become apparent in the HD specimens when primary anti-SP serum is applied to the tissue sections at "supra-optimal" dilutions; that is, dilutions greater than the "optimal" dilutions which visualize maximal numbers of SP-IRPs and concomitantly give maximal staining intensity. Curiously, the application of "optimal" dilutions to the HD and non-HD specimens visualizes equivalent numbers of SP-IRPs; therefore, the qualitative and quantitative differences between the specimens become masked. Applying "supra-optimal" dilutions of the anti-SP serum unmasks the difference, and also reveals different end-points for the immunostain deposited in each type of specimen. In both the HD and non-HD specimens, two sizes of SP-IRPs could be identified, large (3 micron) and small (0.7 micron). Presumably they mark two different categories of axons defined by caliber (e.g., C-type and A gamma), or origin (e.g., sensory intrinsic, or supraspinal). Alternatively the large SP-IRPs label tangentially-cut or large axons and nerve terminals. In the present report, counts of the large and small SP-IRPs visualized in the HD and the non-HD specimens have been plotted against the serial dilutions (optimal, supra-optimal and end-point) of the primary anti-SP serum used for ICC. The graphs which result, describe a "titration curve" characteristic for the large SP-IRPs in each specimen.(ABSTRACT TRUNCATED AT 250 WORDS)

Dose-Response Relationship, Immunologic↗
PubMed1998

Comparative evaluation of two commercial assays for direct detection of Mycobacterium tuberculosis in respiratory specimens.

Two commercial systems for the amplification and detection of Mycobacterium tuberculosis directly from respiratory samples were compared. The Roche Cobas Amplicor MTB Test and the Roche manual Amplicor MTB Test (Roche Diagnostic Systems, USA) were applied to 755 decontaminated respiratory specimens collected from 470 patients. Results were compared with those of acid-fast staining and culture. A total of 251 specimens were collected from 156 patients diagnosed with pulmonary tuberculosis, including 28 specimens corresponding to 13 patients that were receiving antituberculous treatment. Given the overall positivity rate of 33.2% (251/755), the sensitivity, specificity, and positive and negative predictive values were 92.4, 100, 100, and 96.5%, respectively, for the Cobas Amplicor MTB Test and 90.8, 100, 100, and 95.8%, respectively, for the Amplicor MTB Test. For 204 (81.3%) smear positive specimens and 47 (19.7%) smear negative specimens, the sensitivity values were 100 and 59.6%, respectively, for the Cobas Amplicor MTB Test and 100 and 51%, respectively, for the Amplicor MTB Test. There were no statistically significant differences in sensitivity or specificity between the two assays and culture (p>0.05). The overall results of both assays were concordant for 99.5% of the samples. It is concluded that although both nucleic acid amplification methods are rapid and specific for the detection of Mycobacterium tuberculosis complex in respiratory specimens, the Cobas Amplicor MTB Test appears to be slightly more sensitive than the Amplicor MTB Test when smear negative specimens are investigated.

Evaluation Studies as Topic↗
PubMed1995

Comparison of nasopharyngeal aspirates and throat swab specimens in a polymerase chain reaction-based test for Mycoplasma pneumoniae.

Nasopharyngeal aspirates and throat swab specimens were compared in a polymerase chain reaction (PCR)-based test for Mycoplasma pneumoniae. The pathogen was detected in 50% and 45% of throat swab specimens and aspirates, respectively. However, in specimens negative for Mycoplasma pneumoniae by PCR, amplification inhibitors were detected in 0% and 36% of throat specimens and aspirates, respectively. Further investigations confirmed that no throat specimens, but one-quarter of aspirates, are likely to be rejected for containing inadequate respiratory material or excess amplification inhibitors. Because rejection of most of the unsuitable specimens is possible only after PCR, the use of aspirates is less cost-effective. This, and the reluctance to subject patients to aspiration, make the aspirate an inferior specimen for detection of Mycoplasma pneumoniae by PCR.

Adult↗
PubMed2001

Multicenter study of a commercial, automated polymerase chain reaction system for the rapid detection of Mycobacterium tuberculosis in respiratory specimens in routine clinical practice.

A cooperative study was conducted among six laboratories to compare the performance of the Cobas Amplicor (CA) polymerase chain reaction (PCR) system (Roche Molecular Systems, USA) for the detection of Mycobacterium tuberculosis with that of microscopy and culture in routine clinical laboratory diagnosis. A total of 5,221 decontaminated respiratory specimens were tested. The use of an internal control allowed detection of PCR inhibition in 144 (2.8%) specimens. Only two culture-positive samples were CA PCR inhibitory and therefore could not be detected by PCR testing. Of the 333 culture-positive specimens, 278 (83.5%) were positive by the CA PCR. Of the 4,744 culture-negative specimens, 52 (1.1%) were positive by the CA PCR. After analysis of discrepancies, 40 of the 52 culture-negative, CA PCR-positive specimens were classified as true positive. Thus, the overall sensitivities of culture, CA PCR and microscopy were 89.3%, 85.2% and 55.5%, respectively. The overall specificity of the CA PCR was 99.7%. Five of the six centers found similar performances for the CA PCR, with sensitivities ranging from 85.7 to 90.9%. The CA PCR was more sensitive for smear-positive samples, exhibiting overall sensitivities of 96.1% and 71.7% for smear-positive and smear-negative specimens, respectively. These results indicate that the Cobas Amplicor system enables microbiology laboratories with reasonable previous experience in molecular biology testing to perform PCR and to detect Mycobacterium tuberculosis in more than 70% of specimens obtained from infected patients.

Automation↗