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PubMedDate not supplied

Diagnostic accuracy of fine needle aspiration cytology in pancreatic lesions. A review of 77 cases.

Fine needle aspiration cytologic specimens from pancreatic lesions in 77 patients were blindly reviewed. The patients were divided into two subgroups: group A included 19 patients without malignancy of the pancreas, and group B included 58 patients with confirmed malignancy (primary or secondary) of the pancreas. The original cytologic diagnoses in both groups were plotted against the respective reevaluated cytologic diagnoses. In group A there were no false-positive cytologic diagnoses, neither originally nor on reevaluation. In group B, among nine cases originally diagnosed as "benign cells," there were two cases diagnosed as malignant on reevaluation, while in the remaining seven cases malignant cells could not be found on reevaluation. In 11 cases in group B the cell material was considered insufficient for cytologic diagnosis, both originally and on reevaluation. In 34 of the 58 cases (58.6%) in group B a conclusive cytologic diagnosis of malignancy was made both in the original cytologic reports and on reevaluation. In this series, sampling errors accounted for most false-negative cytologic diagnoses. The specificity in our series was 100%. The demonstrated sensitivity was 59% initially and 62% on reevaluation.

Adult↗

PubMed1976

[Development of a simple oral short test with the TSH releasing hormone (TRH) and its use in thyroid diagnosis].

A simple test with 40 mg of oral TRH after overnight fasting was developed and can be characterized as follows: This short oral TRH test has been found to be a most valuable thyroid function test for detection of hyper- and hypothyroidism. It is as reliable as the intravenous TRH test. Oral TRH produces much stronger and more prolonged TSH stimulation similar to that of a depot preparation. Therefore, the incidence of euthyroid controls with absent or subnormal TSH response to TRH is definitely lower than after intravenous TRH. In patients with low TSH response after i.v. TRH the oral TRH test is of particular diagnostic value in distinguishing euthyroid function from TSH suppression or pituitary failure. 40 mg or oral TRH produces reliable stimulation of T3 in most euthyroid subjects. In patients with hyper- and hypothyroidism no increase of T3 is obserable. Oral TRH allows simultaneous assessment of pituitary TSH and thyroid reserve in a single test. The practical advantages (side effects in only 2% [for i.v. TRH 60%], only 1 or 2 blood samples, fewer sampling errors and no i.v. injection) outweigh the disadvantages (longer duration of the test, dependence on food intake and gastrointestinal absorption).

Administration, Oral↗

PubMed1993

[13C-urea breath test].

The 13C-urea breath test is now a practical and readily available alternative to endoscopy- and serology-based methods for the detection of H. pylori infection. It can detect very low levels of H. pylori colonization within the stomach by assessing the entire mucosa, and avoids the risks of sampling error. We performed the 13C-urea breath test in asymptomatic volunteers and patients with gastric and duodenal ulcers in order to compare the sensitivity and specificity by measurement of H. pylori antibody by ELISA. The positive rates of H. pylori in the 13C-urea breath test was correspondent with the results from the H. pylori antibody test, although no correlation in the antibody titers and urease activities was observed between the two methods. The 13C-urea breath test was the most useful method in evaluation of eradication of H. pylori after administration of antibiotics, compared to serological and pathological methods. These results suggest that the 13C-urea breath test is highly useful for the diagnosis of H. pylori infection of the gastric mucosa.

Adolescent↗

PubMed1993

[ELISA tests for detection of Helicobacter pylori antibodies].

The efficacy of commercial ELISA tests for detection of Helicobacter pylori antibodies was investigated. Some investigators reported that six commercial ELISA tests had sensitivities of 81-96%, and had specificities of 29-96%. It is possible that some of false-negative results by ELISA may occur for patients who are in the acute phase of infection. When ELISA tests gave false-positive results, it should be taken into account that there might be some false negative diagnoses for the gastric H. pylori status, arising from sampling errors. Some of the false-positive results by ELISA might indicate the previous infection only.

Antibodies, Bacterial↗

PubMed1993

[Comparison between ELISA and culture method for detection of Helicobacter pylori].

Detection of Helicobacter pylori (H. pylori) by ELISA was compared with that by the culture method in 115 patients with gastroduodenal diseases. Both the sensitivity and specificity were more than 85% for patients with histological gastritis with neutrophil infiltration. This indicated that the detection of H. pylori by ELISA is useful for the diagnosis of H. pylori-related gastritis. Although the sensitivity between the ELISA and culture method was 85%, the specificity was 58.8%. The false negative detection may have been caused by a sampling error during the endoscopic biopsy.

Adult↗

PubMedDate not supplied

Value and limitations of cytologic criteria for the diagnosis of hepatocellular carcinoma by fine needle aspiration biopsy.

In order to further evaluate the utility of fine needle aspiration biopsy (FNAB) cytology for the diagnosis of hepatocellular carcinoma (HCC), we analyzed 39 cytologic features in a series of 102 FNABs from HCC and compared them with 28 FNABs from nonneoplastic conditions. Thirteen features were significantly associated with HCC; from them a stepwise logistic regression analysis selected the three most predictive: irregular arrangement, irregular chromatin pattern and uniformly smaller cytoplasm, the last two found only in HCC. Using different specific combinations of significant cytologic features, the highest sensitivity obtained was 84.3%, with 100% specificity. Sixteen HCC cases could not be diagnosed specifically using the criteria defined in this study, probably due to their well-differentiated nature or to sampling error. Although the use of additional techniques, such as cell block preparations, would improve the results in well-differentiated tumors, we recommend basing the early diagnosis of small HCC on a multidisciplinary approach.

Biopsy, Needle↗

PubMedDate not supplied

Imprint cytology of needle-localized breast lesions.

Intraoperative evaluation of nonpalpable breast lesions by frozen section frequently is not performed because of potential tissue loss, sampling errors and frozen section artifacts. In a retrospective review we found that only 50 of 503 needle-localized breast biopsies (NLBBs) were evaluated at our institution by frozen section (FS), with a sensitivity of 88%. However, intraoperative evaluation of such lesions may be essential to single-stage and cost-effective management. To this end, this study evaluated the diagnostic accuracy and potential clinical role of intraoperative imprint cytology (IIC) in NLBB. A total of 88 lesions were evaluated by IIC and permanent histology. Fifteen of them were also concomitantly evaluated by FS. All but one deferred cytologic diagnoses were correct. Twelve of 15 FS diagnoses were correct, 2 were deferred, and 1 was false negative. The data suggest that IIC may circumvent some of the difficulties associated with FS, thereby allowing immediate clinical management and later definitive histologic typing and evaluation of prognostic parameters in nonpalpable breast lesions.

Adenoma↗

PubMed1993

Fine needle aspiration cytology in the diagnosis of mass lesions of the salivary gland.

Fine needle aspiration was performed on 101 patients with mass lesions of the salivary gland. In 98 patients satisfactory material was obtained. This could be correlated with the histology done in 54 cases. There were 12 inflammatory lesions; 52 benign and 34 malignant tumors. Of the malignant tumors 32 were primary salivary tumors and one case each of lymphoma and leukemia. The overall accuracy was 97 per cent. There were no false positives but one false negative diagnosis. In two cases there was a discrepancy of tumor type between the cytology and histopathology; these were due mainly to sampling errors. This study documents that cytomorphology can characterise a wide range of histologically described lesions including the rare epithelial myoepithelial tumor. The application of stringent criteria in the diagnoses of salivary lesions, even inflammatory conditions like chronic sialadenitis, avoids over-diagnosis. Both inflammatory and neoplastic lesions may be cystic. These cystic lesions may prove to be a pitfall in cytology. Reaspiration of cystic lesions especially from residual solid areas greatly improves accuracy. We suggest that a fore-knowledge of tumor type preoperatively greatly reduces surgery in clinically questionable salivary lesions.

Adolescent↗

PubMed1995

Cyclosporin use in the precolectomy chronic ulcerative colitis patient: a community experience and its relationship to prospective and controlled clinical trials. Pacific Northwest Gastroenterology Society.

OBJECTIVE: To define what effect seminal and controlled clinical trials have on practice patterns within a gastroenterological community. To define whether these practice patterns reproduce reported treatment methods and whether results comparable with those reported in such trials are noted within a community practice setting. METHODS: Mailed surveies, with telephone follow-up, were sent to all members of the Pacific Northwest Gastroenterology Society. Respondents were queried regarding cyclosporin use in the precolectomy chronic ulcerative colitis (CUC) patient. Data collected included patient demographics, disease duration and extent, pre-treatment use of steroids, method, dosage, and duration of cyclosporin therapy, side effects, and short-term and subsequent clinical results. RESULTS: Twenty-one percent of 81 respondents had used cyclosporin for precolectomy CUC, approximately one-half using constant infusion and one-half using parenteral bolus therapy. Side effects attributed to the cyclosporin were noted in eight of 30 patients (27%), and acute colectomy was avoided in 17 patients (57%). Subsequent colectomy was required in an additional nine patients (73% total) within a 6-month follow-up period, a significantly higher colectomy rate than that reported in prospective trials. CONCLUSIONS: Potential reasons precluding cyclosporin use within the gastroenterological community may include lack of knowledge about cyclosporin therapy for CUC, lack of opportunity, skepticism, fear of medication side effects, survey sampling error, or treatment philosophy. Potential reasons for failure to duplicate the results reported in controlled trials are more complex but may include inadequate treatment duration the learning curve associated with the use of a new medication, or acceptance of colectomy as the treatment of choice in patients with acutely or chronically debilitating disease.

Adolescent↗

PubMed1995

A new and cheap medical examination system with artificial intelligence.

This is a medical examination system with artificial intelligence. It is used to find persons who want to obtain higher professional posts in the medical field, including doctors, dentists, nurses, pharmaceutists, etc. It has a question bank of 536,000 multiple choice questions (MCQs), of which 59,500 have pictures. Ten percent of the MCQs is updated every year; the old MCQs in the question bank are used as exercises for the persons who want to obtain higher professional posts. The system, with three distinctive degrees of difficulty, is applicable to three different professional posts: the assistant physician, the resident, and the attending physician. It ensures the general level of assessment for the same professional post, regardless of when one wants to take the system. In addition, the system also guarantees the consistency of the following three factors: the constituent of sub-professions, the classification of MCQs, and the degree of difficulty of each MCQ. Another feature of the system is that the passing score need not be the traditional standard passing score of 60. The passing score is determined by the system according to the requirements of the different professional posts and the degree of difficulty of the MCQs in the system. Therefore, the new method for passing the system is more rational than the traditional one. Moreover, the final score given by the system will be standardized to eliminate sampling errors. The reliability of the system will also be tested after each examination. If the coefficient of reliability is lower than 0.85, the scores will be canceled and examination will be repeated. The system can accept 96 persons simultaneously taking the examination with on-line computers. The people who work in remote places can take examination in their hospital with a personal computer linked via telephone. The system has already been approved by the relevant authoritative departments in China. It has been running successfully for more than six years. During this period of time, 125,645 candidates have taken the exam; 64,078 have passed the examination and have been promoted to higher professional posts. The system runs on local area network and uses a program written in PROLOG and FoxPro. It is estimated that the total cost of developing the system is less than $46,000 (US).

Artificial Intelligence↗

PubMed1996

Biodistribution of the nitroimidazole EF5 (2-[2-nitro-1H-imidazol-1-yl]-N-(2,2,3,3,3-pentafluoropropyl) acetamide) in mice bearing subcutaneous EMT6 tumors.

The characteristic reduction and binding of nitroimidazoles to cellular macromolecules in the absence of oxygen allows their use for detection and characterization of hypoxia. The biodistribution of a new nitroimidazole, EF5 (2-[2-nitro-1H-imidazol-1-yl]-N-(2,2,3,3,3-pentafluoropropyl) acetamide), in mice bearing EMT6 tumors is described. Detection methods based on radioactivity and monoclonal antibody techniques are compared for liver and tumor. All nonexcretory tissues demonstrated similar levels of radioactivity at 0.5 hr postinjection of drug, demonstrating equivalent access of EF5 to all tissues. At 24 hr, when unbound drug has been cleared, the tissues with the highest binding are the liver, esophagus, bladder and tumor. Typically, liver tissue contains the highest level of radioactivity at this time. Examination of tumor and liver tissue by use of fluorescence microscopy and Cy3-bound monoclonal antibodies specific for EF5 adducts showed that the patterns of binding in tumor are considerably more heterogeneous than those of liver. Histograms of fluorescence intensity, with use of these antibodies, demonstrate average and maximal binding higher in tumors than in the liver. This divergence from the radioactivity data was determined to be unrelated to sampling error, differential antibody access or staining efficiency of liver vs. tumor tissue. A possible cause is the scavenging of radioactive drug metabolites by liver. The data presented herein suggest that EF5 is useful as a hypoxia detector and that monoclonal antibody detection methods can give detailed information on the distribution of EF5 binding. This technology may allow an accurate estimation of the oxygenation and/or nitroreductase levels in both tumor and normal tissues.

Animals↗

PubMed1996

Cervical biopsy-cytology correlation. A College of American Pathologists Q-Probes study of 22 439 correlations in 348 laboratories.

OBJECTIVE: To study the diagnostic correlation between cervical cytology specimens and corresponding surgical biopsies. DESIGN AND SETTING: College of American Pathologists Q-Probes laboratory quality improvement study in 348 laboratories. MAIN OUTCOME MEASURES: Sensitivity, specificity, and positive predictive value of cervicovaginal cytology diagnosis. RESULTS: Statistical analysis of 22 439 paired cervicovaginal cytology--cervical biopsy specimens reveals a sensitivity of 89.4%, specificity of 64.8%, and predictive value of a positive cytology of 88.9%. The majority of discrepancies were attributed to cytology or biopsy sampling errors. Routinely providing the patient's recent cervical cytology report to the surgical pathologist at the time the biopsy was examined resulted in improved sensitivity. Correlations for cytology specimens obtained at the time of biopsy revealed lower sensitivity and higher specificity than for those obtained at a time prior to the biopsy. CONCLUSIONS: We have defined current statistical expectations for cervical cytology-biopsy correlation, reasons for noncorrelation, and have provided recommendations for quality improvement.

Biopsy↗

PubMed1996

[Quality control of intraoperative diagnosis].

A retrospective study of 2500 consecutive frozen sections obtained in the period April 14, 1993, through April 29, 1995 from the Institute of Anatomic Pathology of Ospedale "Bellaria" of Bologna is presented. The most frequent of mistakes followed sampling errors. Quality Control of frozen section diagnoses is a valid system for monitoring and improving the accuracy of diagnoses.

Diagnosis↗

PubMed1996

Renal allograft failure after simultaneous pancreas-kidney transplantation: univariate and multivariate analyses of donor and recipient risk factors.

Although donor and recipient risk factors for renal allograft failure are well known after kidney transplantation, they are less well defined after simultaneous pancreas-kidney transplantation. The purpose of this study is to evaluate the impact of donor and recipient risk factors on the outcome of the renal allograft in simultaneous pancreas-kidney recipients. Simultaneous pancreas-kidney transplant performed between 4/88 and 6/94 were reviewed (n = 61) and univariate (Kaplan-Meier) and multivariate (Cox regression) analyses of factors which affect kidney graft survival were performed. Twelve donor and eleven pre- and post-transplant recipient risk factors were evaluated. Overall kidney allograft survival rates at 1, 2 and 5 yr were 81%, 76% and 66%. Donor age > and = 40 yr (RR = 2.3), donor female gender (RR = 3.5), donor admission to pronouncement of brain death > and = 48 h (RR = 3), the occurrence of surgical complications (RR = 2.1), and serum > and = 2 mg/dl on post-transplant day (RR = 1.9) were independently associated with an increased hazard of graft failure. With the exception of length of donor admission, all of these factors were also shown to predict the risk of renal graft failure by univariate analysis. In conclusion, we have identified donor and recipient risk factors which independently predict the risk of renal graft failure after simultaneous pancreas-kidney transplantation. Whether the differences between our center-specific risk factors and those obtained from renal transplant registry data are true differences or simply reflect sampling error is unclear.

Adolescent↗

PubMed1996

Diagnostic tests for Helicobacter pylori: a prospective evaluation of their accuracy, without selecting a single test as the gold standard.

OBJECTIVE: To assess the accuracy of six commonly used diagnostic tests for Helicobacter pylori in a prospective study without using any specific test as the gold standard (the patient was regarded as H. pylori-infected if two or more tests, whatever their nature, were positive). METHODS: In 105 outpatients undergoing upper GI endoscopy, 62 without significant abnormalities, 28 with gastroesophageal reflux disease, 19 with peptic ulcer, one with erosive gastritis, and one with atrophic gastritis (some patients had more than one diagnosis), antral biopsy specimens were taken for culture, polymerase chain reaction, histological examination (hematoxylineosin and Giemsa stains), and rapid urease test. Corpus biopsy specimens were taken for histological examination. Serology (ELISA) and a 13C-urea breath test were also performed. Consistency of diagnosis between two pathologists was assessed by kappa statistics. RESULTS: Sensitivity and specificity, respectively, were as follows: culture, 98.4 and 100%; polymerase chain reaction, 96.7 and 100%; histological examination (antrum), 96 and 98.8%; histological examination (antrum + corpus), 98.4 and 98.8%; rapid urease test, 90.2 and 100%; 13C-urea breath test, 100 and 100%; and serological examination, 98.4 and 88.4% (95% in those who had not been previously treated for H. pylori). All H. pylori-positive cases were detected by culture and rapid urease test. In 86.4% of these cases all antral biopsy-based tests were positive. Agreement between pathologists was good, with a kappa coefficient around 0.90 for antral biopsy specimens. CONCLUSIONS: All antral biopsy-based tests, as well as the 13C-urea breath test, are accurate for the diagnosis of H. pylori infection. Sampling error is a problem of minor importance. The lower specificity of serological tests may be largely explained by previous treatment of H. pylori.

Biopsy↗

PubMed1995

GMP criteria for retest and failure analysis. Handling out-of-specification results in the pharmaceutical quality control laboratory.

The Food and Drug Administration's current Good Manufacturing Practices guidelines for the inspection of pharmaceutical quality control laboratories stress the need for explicit standard operating procedure's requirements for retesting criteria and the investigation of specification failures. Out-of-specification results are best handled through a priori procedures for the evaluation of their validity. These procedures should also specify the degree of retesting or resampling permitted. Initial investigations should focus on uncovering apparent laboratory-related or sampling errors. Should this initial investigation prove inconclusive, an expanded investigation should be conducted to uncover any less conspicuous cause, which could include process or operator-dependent as well as analytical errors. A schematic approach to controlling retesting through a rigorous policy of investigating failures, limiting retest analyses, and documenting and reporting all results is described.

Consumer Product Safety↗

PubMed1996

The value of the white blood cell count and differential in the prediction of neonatal sepsis.

Infection is responsible for significant morbidity and mortality in high-risk neonates. Because infection has many nonspecific signs and symptoms, the neonatal nurse plays a crucial role in the early recognition of infection. The interpretation of the white blood cell (WBC) count and differential can be difficult and must take into account many factors, including gestational age, weight, and postconceptional age. This article focuses on those factors that affect WBC interpretation, as well as steps nurses can take to minimize specimen and sampling errors.

Bias↗

PubMed1997

Common problems in Papanicolaou smear interpretation.

No test ever invented has been as successful as the Papanicolaou smear in preventing cancer. Despite its remarkable success in cervical cancer prevention, however, the Papanicolaou smear is not a perfect test. Sampling errors account for a significant number of false-negative cases. Diagnostic errors occur in even the finest cytology laboratories. Yet, for women who develop cervical cancer, these errors pale in comparison with failure to screen patients adequately in the first place. This paper examines some of the problems that result in failure of the Papanicolaou smear to prevent cervical cancer, with an emphasis on common problems in Papanicolaou smear interpretation.

Diagnostic Errors↗