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PubMed1994

Effects of specimen load-bearing and free surface layers on the compressive mechanical properties of cellular materials.

The influence of load-bearing surface layers on Young's modulus was determined for cancellous bone and polyurethane foam specimens of three different heights cut from each material: 16, 9, and 5 mm for bone specimens (cross-sectional area A = 81 mm2) ranging in density from 0.04 to 0.32 g cm-3; 20, 10, and 5 mm for foam specimens (A = 100 mm2) ranging in density from 0.064 to 0.64 g cm-3. The compressive elastic modulus of the 5 mm bone specimens was significantly smaller (42%) than that of the 16 mm bone specimens. A similar change in elastic modulus was also observed for the foam specimens, but the height effect diminished in a relatively linear manner as the foam density increased. For a height change from 20 to 5 mm, the foam modulus difference ranged from a 41% decrease for the lowest density specimens (p = 0.064 g cm-3) to an insignificant change (< 1.8%) for the highest foam density specimens (p = 0.64 g cm-3). The specimen height effect on elastic modulus was hypothesized to result from a higher deformation (compliance) of the cellular materials in the load-bearing or contacting surface layer than in the bulk. A mathematical formula was derived to predict the variation in measured elastic modulus (E) caused by the contacting surface layer modulus (Ecs) to bulk modulus (Eb) ratio (Y = Ecs/Eb) and contacting surface layer height (hcs) to sample height (h) ratio (t = hcs/h): E/Eb = Y/[Y(1-t)+t]. Predicted differences in the measured modulus associated with graduated specimen heights were verified experimentally by regional strain measurements of the foam and bone samples using an optical microscope. The influence of free-surface layers was also determined for the foam specimens with cross-sectional areas 1.21 and 10 times the load-bearing area of a load platen, but the measured differences were small (< 10%) compared to that of the load-bearing surface layer influence. In future compressive mechanical testing of cellular materials, specimens < 10 mm in height should be avoided, particularly specimens with low bulk density or high porosity.

Adult↗
PubMed2004

Influence of substrate, shape, and thickness on microtensile specimens' structural integrity and their measured bond strengths.

OBJECTIVES: To verify whether substrate, shape, or thickness of microtensile specimens have a significant influence on their measured bond strength. METHODS: Sixty-four extracted molars provided microtensile specimens, which were prepared on enamel and dentin, in different shapes and thicknesses. The teeth were randomly divided into 16 groups (n = 4). Groups 1-8 included hourglass-shaped specimens. In Groups 1-4 specimens were prepared from enamel and in a thickness at the bonding interface of 0.5 mm x 0.5 mm, 1 mm x 1 mm, 1.5 mm x 1.5 mm, and 2 mm x 2 mm, respectively. In these same thicknesses, hourglasses were trimmed in Groups 5-8, but the specimens were prepared from dentin. Groups 9-16 included specimens obtained following the non-trimming technique. Groups 9-12 provided enamel sticks in the four evaluated thicknesses. In these same thicknesses and shape but from dentin were cut the specimens of Groups 13-16. Two specimens from each group were viewed using a scanning electron microscope. On the other ones, microtensile bond strength was measured and the values were statistically analyzed. RESULTS: Substrate, shape, and thickness of the specimens had a significant effect on their recorded bond strength (p < 0.05). Higher bond strength values were recorded by dentin versus enamel specimens and by sticks versus hourglasses. Also, bond strength decreased as specimen thickness increased. SEM analysis revealed that the trimmed specimens, especially if from enamel, often exhibited lines of fracture in the area of action of the bur. SIGNIFICANCE: It seems advisable to avoid the trimming action particularly on enamel specimens. If the hourglass shape is preferred, the cross-sectional area should not exceed 1 mm x 1 mm.

Analysis of Variance↗
PubMed1992

Human papillomavirus DNA in cervix. In-situ hybridization with biotinylated probes on Bouin's fixed paraffin embedded specimens.

We examined retrospectively a series of 65 Bouin's fixed, paraffin-embedded tissue specimens from 8 condylomatous lesions, 16 condylomas associated with cervical intraepithelial neoplasia (CIN), and 12 neoplasia without condylomatous signs, for histological characteristics, the detection of viral structural antigen, the presence and typing of HPV DNA by molecular in situ hybridization with biotinylated probes types 6, 11, 16 and 18 under stringent conditions (Tm - 12 degrees C). HPV DNA was present in 34/65 (52%) specimens. Detection of viral structural antigen was positive in only 14% (3/22) specimens. HPV DNA were identified in 9/9 (100%) condylomatous lesions (with HPV type 6, 11, 18). Three condylomas were coinfected with both HPV type 6 or 11 and type 18; viral antigen was found in two specimens. HPV DNA were detected in 18/31 (58%) low grade and advanced CIN associated with condylomatous changes (type 6 = 5 specimens, type 11 = 3 specimens, type 16 = 4 specimens, type 18 = 6 specimens). Four of these cases were coinfected with both HPV type 6/11 and HPV type 16/18. Viral antigen was negative in all specimens. HPV DNA were detected in 7/25 (28%) advanced intra-cervical neoplasia (CIN III) without anatomopathological condylomatous changes (type 6 = 1 specimen, type 16 = 3 specimens, type 18 = 3 specimens). One of these specimens contained both HPV types 6 and 18. Viral antigen was found in one case. Our data confirm the association of HPV types 6 and 11 with condyloma and low grade neoplasia; HPV types 16 and 18 were associated with advanced cervical neoplasia.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetates↗
PubMed2000

Simultaneous detection and strain differentiation of Mycobacterium bovis directly from bovine tissue specimens by spoligotyping.

Culture of Mycobacterium bovis is used routinely to support field diagnosis of bovine tuberculosis; however, this method is slow. Rapid detection and strain-typing of M. bovis directly from 37 lesioned bovine lymph node specimens was performed by the polymerase chain reaction (PCR) based method, spoligotyping. Mycobacterial DNA was extracted from the specimens using a nucleic acid sequence capture technique. Two sets of specimens were tested, the first set comprising 16 decontaminated tissue homogenates from lesioned lymph node specimens which had been processed for BACTEC culture and a second set of 21 non-decontaminated lesioned lymph node specimens. Both sets of specimens had been frozen before analysis. Sequence capture PCR enabled detection and strain-typing of M. bovis directly from 15 of the 16 decontaminated homogenates and all 21 of the non-decontaminated tissues. Four spoligotype (ST) patterns were obtained from each set; ST1, ST2, ST3 and ST16 were detected in the decontaminated specimens and ST1, ST2, ST11 and ST14 in the non-decontaminated specimens. For both sets of specimens, ST1 was the predominant strain type detected. ST patterns obtained from the BACTEC cultures of the decontaminated specimens were in agreement with those obtained directly from the tissue. The sensitivity of detection by sequence capture-PCR compared very favourably with that of BACTEC culture. ST patterns were obtained directly from tissues of 34 of the 35 culture positive specimens and the two culture negative specimens. DNA extraction from the 21 non-decontaminated specimens involved an initial stomaching treatment. An assessment of sequence capture on both liquid alone and liquid and tissue homogenate combined, following stomaching, indicated that PCR was less successful on the liquid component alone.

Animals↗
PubMed1998

Viability of human semen specimens cryostored and transported at 5 C using the Bio-Tranz shipping system.

Objective: Transport of unprocessed human semen specimens from the production site to distant laboratories for andrological evaluation and clinical use requires the development of proper protocols and devices for the shipment and maintenance of sperm viability during transport. Factors such as maintenance of proper temperature and the specific diluent used are considered to affect the viability of semen specimens during transport. The Bio-Tranz shipper (ZDL, Inc., Lexington, KY, USA), which was designed to cool specimens (5 C) during transport, consists of a properly refrigerated Styrofoam box, TEST-yolk Buffer (TYB), a nonspermicidal condom-shaped semen collection kit (Hygene Kit; ZDL, Inc.) and test tubes (15.0 mL). The viability of semen specimens stored from the time of collection to the time at which the specimens were to be processed and used (24 hours post-collection) was evaluated using the Bio-Tranz shipping technology.Methods: Semen specimens (n = 30) were assessed for percentage and grade of motility (0-4), and for the sperm membrane functional integrity as measured by the hypoosmotic swelling (HOS) test at collection time and 24 hours after storage in the Bio-Tranz shipper. The specimens were produced at intercourse via the use of the Hygene collection kit, assessed for sperm characteristics, split into two aliquots and then transferred to 15.0 mL test tubes. Aliquot 1 was mixed 1:1 (v/v) with TYB media and aliquot 2 was used as raw (unprocessed). The specimens were then placed and secured in the Bio-Tranz shipper and assessed for sperm qualitative characteristics following 24 hours of storage.Results: The results of the sperm parameters assessed among the various seminal treatments are shown below:Sperm characteristics were significantly improved when preparing the specimens using TYB (0 h; P <.05). Significant differences in all sperm qualitative characteristics assessed were noticed between raw specimens and those prepared via TYB after 24 hours of storage (P <.05). Most interestingly, sperm characteristics between raw specimens (0 h) and specimens prepared using TYB and stored via the use of the Bio-Tranz shipper for 24 hours were not different (P <.05).Conclusion: The results obtained show that collection and shipment of semen specimens via the Bio-Tranz shipper system is possible. The Bio-Tranz shipper maintains adequate sperm viability after 24 hours of cryostorage. The use of the Bio-Tranz shipper is extremely convenient for patients that request semen processing services such as semen cryostorage, semen evaluation, semen preparation for IUI purposes, or other assisted reproductive technologies. The technique could be of significant clinical and economic importance to the patient and to the treating physician at locations across the United States.

Journal Article↗
PubMed2003

[Bacteriological and epidemiological study on Neisseria gonorrhoeae isolated from the pharyngeal specimens of male and female patients with gonorrhea].

Neisseria gonorrhoeae were isolated from pharyngeal specimens of male and female patients and also from urethral and cervical discharges of male and female patients, respectively, suspected of having gonococcal infections in a urologic clinic in Kawasaki City. Microbiological and epidemiological studies were performed in 127 male and 41 female patients. The specimens were streaked onto the modified Thayer-Martin Selective Agar and the plates were incubated at 35 degrees C for 48 h under an atmosphere of 10% CO2. In 127 male patients, N. gonorrhoeae were detected in 117 (92.1%) of the urethral specimens. In these patients, N. gonorrhoeae were detected in pharyngeal specimens from 14 (11.0%) patients, but the pathogen was also detected in urethral specimens from these patients without exception. In 41 female patients. N. gonorrhoeae were detected in 20 (48.8%) of the 41 cervical discharges. When the pharyngeal specimens were tested, N. gonorrhoeae were detected in 14 (34.1%) of the 41 specimens. N. gonorrhoeae was simultaneously detected only in pharyngeal and cervical specimens from 11 of the 41 female patients and the pathogen was detected only in pharyngeal specimens from other 3 patients. There were no marked differences in antimicrobial susceptibilities between N. gonorrhoeae isolates from pharyngeal specimens and those from urethral or cervical discharges in all the patients tested. The PFGE patterns of 50 gonococcal isolates (25 pairs) from 25 patients (14 males and 11 females) in whom N. gonorrhoeae were simultaneously detected from pharyngeal and urethral or cervical specimens were analyzed. In 24 of 25 patients. N. gonorrhoeae isolated from the pharyngeal and urethral or cervical specimens in the same patients showed the same PFGE patterns. However, the 25 pairs showed the different PFGE patterns. From these results it is clarified that N. gonorrhoeae are detected in the pharyngeal specimens from considerable numbers of patients with gonorrhea, and there is a possibility that the pathogens prevailing among the patients differ in genetic sources.

Cervix Uteri↗
PubMed1998

Performance of a PCR assay for detection of Pneumocystis carinii from respiratory specimens.

This study evaluates the performance of a PCR assay for the detection of Pneumocystis carinii from respiratory specimens that has been designed for use in the clinical microbiology laboratory. The test includes a simple method for nucleic acid extraction and amplification, a colorimetric probe hybridization technique for detection of amplicons, and an internal control to evaluate for the presence of inhibitors of amplification. Two hundred thirty-two clinical specimens (120 induced-sputum [IS] and 112 bronchoalveolar lavage [BAL] specimens) from 168 patients were tested by both immunofluorescent (direct fluorescent-antibody [DFA]) staining and PCR. Of the 112 BAL specimens, 17 were positive for P. carinii by DFA staining and PCR. An additional two specimens were DFA negative and PCR positive. For BAL specimens, the sensitivity and specificity of PCR compared to DFA were 100 and 98%, respectively. Eighteen IS specimens were positive for P. carinii by DFA, and 27 were positive by PCR. One of the 18 DFA-positive IS specimens was negative by PCR; this patient had just completed therapy for P. carinii pneumonia. Of the 10 specimens that were PCR positive and DFA negative, 4 were from patients who had a subsequent BAL specimen that was positive by DFA and PCR. For IS specimens, the sensitivity of DFA and PCR was 82 and 95%, respectively. The specificity of PCR for IS specimens was 94%. Due to the high sensitivity of PCR for the detection of P. carinii from IS specimens, a PCR-based diagnostic test may be a useful screening test and may alleviate the need for bronchoscopy in some patients.

Bronchoalveolar Lavage Fluid↗
PubMed2003

Commercial assay for detection of Giardia lamblia and Cryptosporidium parvum antigens in human fecal specimens by rapid solid-phase qualitative immunochromatography.

The ImmunoCard STAT! Cryptosporidium/Giardia rapid assay (Meridian Bioscience, Inc.) is a solid-phase qualitative immunochromatographic assay that detects and distinguishes between Giardia lamblia and Cryptosporidium parvum in aqueous extracts of human fecal specimens (fresh, frozen, unfixed, or fixed in 5 or 10% formalin or sodium acetate-acetic acid-formalin). By using specific antibodies, antigens specific for these organisms are isolated and immobilized on a substrate. After the addition of appropriate reagents, a positive test is detected visually by the presence of a gray-black color bar (regardless of the intensity) next to the organism name printed on the test device. A control is included in the device. Steps include tube preparation (buffer, patient specimen, conjugates A and B), testing (addition of sample onto the test device), and visual reading (total time, 12 min). Test performance was evaluated with known positive and negative stool specimens (170 specimens positive for Giardia and 231 specimens negative for Giardia) (85 specimens positive for Cryptosporidium and 316 specimens negative for Cryptosporidium); they were tested with trichrome, iron-hematoxylin, or modified acid-fast stains or the Meridian Bioscience, Inc., Giardia/Cryptosporidium Merifluor combination reagent; specimens with discrepant results were retested by using the Merifluor combination reagent. On the basis of the results of the reference methods, the sensitivities, specificities, and positive and negative predictive values were as follows: for G. lamblia, 93.5, 100, 100, and 95.5%, respectively; for C. parvum, 98.8, 100, 100, and 99.7%, respectively. False-negative results for G. lamblia were obtained with specimens with low parasite numbers (n = 7) or specimens containing trophozoites only (n = 3); one specimen with a false-negative result contained numerous cysts. The one specimen false negative for C. parvum was confirmed to be positive by immunofluorescence. No cross-reactivity was seen with 10 different protozoa (152 challenges), nine different helminths (35 challenges), or human cells (4 challenges) found in fecal specimens. This rapid test system may be very beneficial in the absence of trained microscopists; however, for patients who remain symptomatic after a negative result, the ova and parasite examination and special stains for other coccidia and the microsporidia should always remain options.

Animals↗
PubMed1997

The optimal number of pleural biopsy specimens for a diagnosis of tuberculous pleurisy.

STUDY OBJECTIVES: To determine the optimal number of pleural biopsy (PLBX) specimens for a diagnosis of tuberculous pleurisy. DESIGN: Retrospective review. SETTING: County hospital. METHODS: We reviewed all percutaneous needle biopsy specimens of the parietal pleura in 30 patients who had tuberculous pleurisy. Data are reported as mean+/-SEM and statistical comparisons are done with the Mann-Whitney test. We accepted p<0.05 as statistically significant. RESULTS: The number of biopsy specimens obtained from each patient ranged from 4 to 10 with 1 sample submitted for mycobacterial culture and the rest submitted for histologic study. Sixty percent of patients had pleural cultures positive for Mycobacterium tuberculosis and 80% had diagnostic histology. Overall pleural biopsy sensitivity (histology and culture) for tuberculous pleurisy was 87%. On average, 40.4%+/-4.7% of all PLBX specimens contained pleura. Diagnostic PLBX procedures compared to false-negative procedures produced more tissue specimens (7.1+/-0.3 vs 4.8+/-0.5, p=0.005) containing more pleural specimens (2.4+/-0.2 vs 0.8+/-0.5, p=0.01). If only PLBX procedures yielding more than six tissue specimens (n=18) or more than two pleural specimens (n=12) were analyzed, then the diagnostic sensitivity of PLBX for pleural tuberculosis was 100%. There seemed to be a direct relationship between the sensitivity of PLBX and the number of specimens submitted. CONCLUSIONS: The sensitivity of percutaneous needle biopsy for diagnosis of tuberculous pleurisy is highest when more than six specimens are obtained which, on average, contain more than two specimens of parietal pleura. There are no conclusive data indicating how many tissue specimens to submit for mycobacterial culture, but one specimen seems sufficient.

Adult↗
PubMed2004

Histologic comparison of skin biopsy specimens collected by use of carbon dioxide or 810-nm diode lasers from dogs.

OBJECTIVE: To compare histologic artifacts caused by carbon dioxide (CO2) or 810-nm diode surgical lasers used to obtain small biopsy specimens of skin from healthy dogs. DESIGN: Prospective study. ANIMALS: 4 dogs. PROCEDURE: 21 skin biopsy specimens were collected from each dog. Three biopsy specimens were obtained with a CO2 or an 810-nm diode laser at 3 operating settings each, and 3 biopsy specimens were obtained with a 6-mm biopsy punch instrument (controls). After processing, biopsy specimens were examined for artifacts related to laser-tissue interactions. Microscopically visible char was measured from the lateral edge of each specimen obtained with a laser. RESULTS: There were no significant differences among mean char distances in biopsy specimens obtained with the CO2 laser at various settings. Mean char distance was significantly greater in all skin biopsy specimens obtained with the diode laser, compared with those obtained with the CO2 laser. Mean char distance was significantly greater in biopsy specimens obtained with the 810-nm diode laser at high power, compared with biopsy specimens obtained with the 810-nm diode laser at low power. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that the CO2 laser caused less thermal injury at margins of skin biopsy specimens; therefore, if a surgical laser is used for removal of cutaneous masses or to obtain skin biopsy specimens, use of the CO2 laser is recommended. Veterinarians performing a biopsy by using a surgical laser should be aware that laser-induced artifacts may render small biopsy specimens useless for providing accurate histologic diagnosis.

Animals↗
PubMed2005

PCR testing of pooled longitudinally collected cervical specimens of women to increase the efficiency of studying human papillomavirus infection.

In large active cohort studies of women investigating human papillomavirus (HPV) and cervical neoplasia, many women will be HPV-negative at all time points and testing of all their cervical specimens is an inefficient use of laboratory resources. The aim of this pilot study was to evaluate whether pooling cervical specimens from the same woman might provide a useful pretest of specimens from women unlikely to have high-grade cervical neoplasia or significant HPV exposure. We selected women (n = 187) participating in the Guanacaste Project for whom we already had HPV testing data on all their specimens from multiple visits (median = 8 visits), who were HPV DNA-negative at enrollment and at their 5- to 7-year exit from the cohort, and had no evidence of high-grade cervical neoplasia. Equal aliquots of cervical specimens from these women were pooled to create a proportional pooled specimen. Aliquots of pooled specimens were tested in a masked fashion by MY09/11 L1 consensus primer PCR. Second aliquots of some pooled specimens (n = 83) were included to assess the reliability of pooled testing. Results were compared with the predicted (expected) results based on the obtained test results of the individual specimens collected at interim visits. There was good overall agreement between observed and expected HPV DNA positivity, with a kappa of 0.63 [95% confidence interval (95% CI), 0.51-0.75] and a percent agreement of 83.4% (95% CI, 77.3-88.5%) although the HPV DNA positivity in the pooled specimen was less than expected (P = 0.001). The agreement between observed and expected HPV DNA positivity was related to the number of aliquots pooled, suggesting that positivity was related to viral genome concentrations. The kappa and percent agreement for intra-batch reliability of testing pooled specimens were 0.68 (95% CI, 0.53-0.84) and 84.3% (95% CI, 74.7-91.4%), respectively. We conclude that pooling specimens and testing by PCR may be useful for discriminating HPV DNA-positive from completely negative specimen sets in women who are likely to have been HPV DNA-negative.>

Female↗
PubMed1996

Quality evaluation of sputum specimens for mycobacterial culture.

The evaluation of sputum specimen quality before bacterial culture is an accepted practice. Traditionally, sputum received for mycobacterial culture has been processed regardless of specimen quality. In view of the increasing emphasis placed on the primary acid-fast smear, the effect of specimen quality and the contribution of the presence of neutrophils on subsequent smear and culture positivity for mycobacteria was assessed. A total of 873 sputa were evaluated and initially assigned a quality (Q) score of 1 (many squamous cells relative to neutrophils) to 3 (no squamous cells) based on criteria for specimen acceptability for routine bacterial culture. The percentage of specimens that were Q1, Q2, and Q3 were 46.8, 35.3, and 17.9, respectively. Most of the specimens received were Q1, and these specimens demonstrated the highest number of positive smears and cultures compared to Q2 or Q3 specimens. Thus, routine bacterial culture criteria were not helpful in assessing specimen quality for mycobacterial culture. The contribution of the presence of neutrophils to smear and culture positivity was assessed. A total of 724 sputa were evaluated for cellular composition: 665 (91.9%) specimens contained neutrophils, and 59 (8.1 %) did not contain neutrophils. A total of 51 (7.0%) primary smears and 121 (16.7%) cultures were positive for mycobacteria; 92.2% of the positive smears; and 90.1 % of the positive cultures were from specimens that contained neutrophils. Thus, screening sputum specimens for the presence of neutrophils provides an effective method to evaluate the acceptability of sputum for mycobacterial smear and culture, especially from patients in respiratory isolation.

Bacteriological Techniques↗
PubMed2002

Multiplex LightCycler PCR assay for detection and differentiation of Bordetella pertussis and Bordetella parapertussis in nasopharyngeal specimens.

A rapid real-time multiplex PCR assay for detecting and differentiating Bordetella pertussis and Bordetella parapertussis in nasopharyngeal swabs was developed. This assay (LC-PCR-IS) targets the insertion sequences IS481 and IS1001 of B. pertussis and B. parapertussis, respectively, and is performed using the LightCycler (Roche Molecular Biochemicals, Indianapolis, Ind.). The analytical sensitivity is less than one organism per reaction. Results for Bordetella culture and/or direct fluorescent antibody testing and a second LightCycler PCR assay (target, pertussis toxin gene) were compared to results of the LC-PCR-IS assay for 111 nasopharyngeal swabs submitted for pertussis testing. Of the specimens, 12 were positive (9 B. pertussis and 3 B. parapertussis) and 68 specimens were negative by all methods. Three other specimens were positive for B. pertussis by at least two of the methods (including the LC-PCR-IS assay), and another 28 specimens were positive for B. pertussis by the LC-PCR-IS assay only. No specimens were negative by the LC-PCR-IS assay and positive by the other methods. A conventional PCR method (target, IS481) was also compared to the LC-PCR-IS assay for a different group of nasopharyngeal swab specimens (n = 96): 44 specimens were positive and 41 specimens were negative for B. pertussis with both PCR methods. Nine specimens were positive for B. pertussis by the LC-PCR-IS assay and negative by the conventional PCR assay, and two specimens were positive for B. pertussis by the conventional PCR assay and negative by the LC-PCR-IS assay. Positivity of the two assays was not significantly different (P = 0.0654). The insertion sequence IS481 is also present in Bordetella holmesii; specimens containing B. holmesii may yield false-positive results. The LC-PCR-IS assay takes approximately 45 min to complete post-nucleic acid extraction, compared to 24 h for the conventional PCR assay previously used in our laboratory. The LC-PCR-IS assay is easier to perform than the conventional PCR assay, and the closed system decreases the chance of contamination. All of these characteristics represent a significant improvement in the detection of B. pertussis and B. parapertussis in nasopharyngeal specimens.

Bordetella↗
PubMed1985

United Kingdom scheme for external quality assessment in virology. Part II. Specimen distribution, performance assessment, and analyses of participants' methods in detection of rubella antibody, hepatitis B markers, general virus serology, virus identification, and electron microscopy.

Methods for the preparation and pre-distribution testing of specimens for external quality assessment in virology have been defined and criteria for allocation of scores for participants' reports on each category of specimen have been established. Specimens for detection of rubella antibody or markers of hepatitis B infection consist of human serum samples, which are distributed after detailed assessment of the expected results. In testing for rubella antibody or hepatitis B surface antigen (HBsAg) the scores given for reports of positive, equivocal, or negative depend on the specimen's content of antibody or HBsAg as established in the external quality assessment laboratory. For general virus serology two serum samples must be tested against a designated antigen by the complement fixation method; the score allocated for each participant's results depends on the ratio of the two titres he records, which is then compared with a target value derived from the results of a panel of participating laboratories. In virus identification and electron microscopy specimens are prepared from cultures or from clinical samples, and scores depend on the accuracy of identification. The pre-distribution tests necessary to establish the virus content and stability of these specimens have been defined, and media suitable for transporting specimens for virus culture, fluorescent antibody staining, or electron microscopy have been developed. A participant's overall success rate for each specimen is judged from the mean score (maximum 2) calculated from the scores of all participants examining the specimen. Mean scores were highest for detection of rubella antibody or HBsAg (from 1.67 to 1.96) and lowest for specimens containing certain small enteric viruses distributed for electron microscopy (0.82 to 1.12). Participants' reports on the methods used for each specimen have been analysed. Current changes and developments in methods have been recorded, and attempts have been made to relate the use of various techniques and test kits to successes or failures with various types of specimen.

Antibodies, Viral↗
PubMed1989

Influence of storing urogenital specimens at -20 degrees C before testing by enzyme amplified immunoassay (IDEIA) to detect Chlamydia trachomatis antigen.

Urogenital specimens from 445 patients, 174 women and 271 men, were tested for antigen to Chlamydia trachomatis by an enzyme amplified immunoassay, IDEIA. The test results for specimens stored at -20 degrees C for means of 9.6 weeks (from each of the first 376 patients) and eight months (from the remaining 69) were compared with results for specimens stored at 4 degrees C and tested within five days. Of 617 specimens (one from the urethra of each patient and one from the cervices of 172 women) cultured for C trachomatis, 90 (15%) gave positive results. The IDEIA results for specimens stored at -20 degrees C were identical with those of specimens analysed without such storage in 96.4% (595/617) of all cases. No difference was seen between urethral specimens from men or women or cervical specimens or between specimens stored for 9.6 weeks compared with those stored for eight months. In 22 cases in which the IDEIA results differed, culture positive results were missed in stored as well as unstored specimens. The median absorbance value above the cut off point for a positive IDEIA result in stored specimens was no lower than in those not stored. The few differences noted probably depended on the sampling technique rather than on the way of storing the specimens.

Adolescent↗
PubMed1992

The importance of stabilizing the specimen taken at needle localized biopsy of the breast for microcalcifications.

The specimen from a needle localized biopsy of the breast must be compared with its roentgenogram to locate the area of microcalcification within the specimen. Any errors in aligning the specimen to its roentgenogram could result in failure to sample and microscopically examine the area of the microcalcifications. The results of the current study show the importance of maintaining the orientation and position of the specimen from the time the roentgenogram is taken until it is examined by the pathologist. Each of 45 consecutive specimens taken at biopsy were secured to a square of cardboard immediately after excision from the breast to maintain the orientation of the specimen during the process of roentgenography. The histologic findings of this group (group 2) were compared with the preceding 87 biopsies (group 1) in which no effort had been made to immobilize the specimen for a roentgenogram. The presence of microcalcifications was confirmed roentgenographically in all the specimens of each group. Histologic confirmation of the presence of microcalcifications was obtained in 42 of 45 specimens in group 2 and only 71 of 87 in group 1 (p = 0.035). Thirty-one per cent of specimens in group 2 contained a carcinoma compared with 10 per cent in group 1. We conclude that fixing the position of the specimen after excision improves the ability of the pathologist to locate the suspicious area of microcalcifications within the specimen. This may lead to an increase in the yield of these biopsies and the identification of occult carcinomas that might otherwise be missed.

Adult↗
PubMed1998

Expression of interleukin (IL)-12 mRNA in gastric carcinoma specimens: cellular antitumor immune responses.

BACKGROUND AND OBJECTIVES: Several tumor-related antigen peptides that are recognized by autologous cytolytic T cells (CTL) have been reported. However, most human solid tumors, including gastric carcinoma, are only weakly immunogenic. In this study, we focused on interleukin (IL)-12 and interferon-gamma (IFN-gamma) as key cytokines for estimating positive cellular immune responses. METHODS: To estimate the immunogenicity of gastric carcinomas, we examined IL-12 and IFN-gamma at mRNA levels by reverse transcription-polymerase chain reaction assay (RT-PCR) in tumor specimens and adjacent nontumor specimens from 36 gastric carcinoma patients. RESULTS: IL-12 expression was detected in 12 tumor specimens and in only two adjacent nontumor specimens (P = .003). The frequency of IFN-gamma gene expression was higher in the IL-12 mRNA-positive tumor specimens than in the IL-12 mRNA-negative tumor specimens (P = .015). In the IL-12 mRNA-positive tumors, IFN-gamma expression was higher in the tumor specimens than in the adjacent nontumor specimens (P = .007). Conversely, in the IL-12 mRNA-negative tumors, IFN-gamma expression was lower in the tumor specimens than in the nontumor specimens (P = .03). Many tumor-infiltrating mononuclear cells, predominantly T cells, were found in four of the 12 IL-12-mRNA-positive tumor specimens and in none of the 24 IL-12-mRNA-negative tumor specimens (P = .008). CONCLUSIONS: These data suggest that possible immune responses against a tumor may occur at the mRNA level in approximately one-third of gastric carcinomas.

Blotting, Southern↗
PubMed2002

Gleason scores of prostate biopsy and radical prostatectomy specimens over the past 10 years: is there evidence for systematic upgrading?

BACKGROUND: With the advent of the prostate specific antigen (PSA) assay, an increased detection rate of prostate carcinoma has ensued. This has been associated with a downward stage migration. In contrast, grade has shifted heavily toward moderate differentiation. The authors sought to test the hypothesis that such changes in grade in part may be because of trends among pathologists to upgrade similar specimens over time. METHODS: Two expert genitourinary pathologists regraded 23 prostate biopsies and 15 radical prostatectomy specimens during a 3-year period (1989-1991). Each pathologist then regraded 32 prostate biopsies and 15 radical prostatectomies from 1998 to 2000. For both time periods, each pathologist regraded only specimens that they personally had graded initially. All specimens were scored using the Gleason system, the predominant system used in describing prostate carcinoma grade. In evaluating original and regraded scores, the authors classified score changes between less than or equal to 6 and greater than or equal to 7 or between 7 and greater than or equal to 8 as significant because such changes have a high probability of altering clinical management. The results were analyzed using the two-tailed Fisher exact test. RESULTS: Of 23 prostate biopsies from 1989 to 1991, 10 of 23 (44%) had a clinically significant Gleason score change when regraded, whereas 2 of 15 (13%) radical prostatectomy specimens from the same period had a clinically significant Gleason score change. A significant change in the distribution of biopsy Gleason scores on regrading was observed (P < 0.04). In comparison, when the prostate biopsies from 1998-2000 were regraded, 10 of 32 (31%) had a clinically significant grade change. Radical prostatectomy specimens from the same period revealed 3 of 15 (20%) with a clinically significant grade change. After regrading the biopsies from 1989-1991, 8 of 23 (35%) of were upgraded, whereas 2 of 23 (9%) were downgraded. In comparison, of the biopsies with significant changes from 1998 to 2000, 3 of 32 (9%) were upgraded, whereas 7 of 32 (22%) were downgraded. Of the radical prostatectomy specimens with significant change, only 2 of 15 from each period were upgraded. Significant upgrading (P < 0.005) occurred only in the biopsy specimens from 1989 to 1991. CONCLUSIONS: The authors' data suggest that rates of upgrading and downgrading of biopsy specimens differ between the 1989-1991 cases and the 1998-2000 cases, with the 1989-1991 samples exhibiting a significant change toward higher grades. Although not excluding the possibility of a change in the biology of prostate carcinoma over time, these findings suggest that the apparent trend toward higher biopsy grades in part may be because of how pathologists interpret these specimens today as compared with 10 years ago. Therefore, outcome studies including a biopsy Gleason score from older specimens as a risk variable have a significant chance of being vulnerable to this phenomenon. Based on the authors' data, all such specimens should undergo rereview.

Biopsy, Needle↗