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PubMed1997

[Virtual CT colonoscopy. Examination technique, limitations and perspectives].

Virtual CT-colonoscopy is a post-processing method which allows for reconstruction of inner bowel surface structures from helical CT datasets. The reconstructed images simulate the views which are known from fiberoptic endoscopy. Since colorectal cancer is the second main cause of death in USA and Europe today and since recent screening recommendations are often ignored by the public, a non-invasive or minimal-invasive procedure for colonic evaluation would offer some benefits. Virtual CT-colonoscopy generally involves three essential steps: patient preparation with cleansing of the bowel and administration of an air enema, helical CT-examination by using appropriate scan parameters, and interactive 3D rendering of the volume data-set. Although recent studies have demonstrated that polypoid lesions of about 5 mm size are well detectable and although virtual colonoscopy offers many advantages over fiberoptic endoscopy, some technical and clinical limitations must still be noted. Thus, the current inability of virtual colonoscopy to provide texture and color leads to problems in identifying flat lesions; the presence of retained or adherent fecal matter may result to false positive diagnosis and collapsed segments of bowel may cause problems as they cannot subsequently be evaluated during image reconstruction. Virtual endoscopy is still in its infancy and further technical and clinical developments are necessary. Virtual CT-colonoscopy may then prove to be equal or superior to colonoscopy in sensitivity and specificity for polyp detection and be able to reduce the number of unnecessary colonoscopic procedures.

Colonoscopes↗
PubMed1981

Reliability of the toxic screen in drug overdose.

To determine the reliability of the laboratory in detecting drugs taken by overdosed patients, we evaluated laboratory performance on an unbiased sample of actual clinical specimens. Replicate serum and urine samples from a series of 20 consecutive clinically overdosed patients were sent to three commercial laboratories and one academic research laboratory for identification and quantification of intoxicating agents. All laboratories used the advance analytical techniques of gas chromatography-mass spectrometry. The results suggest that laboratories do not reliably identify drugs in the serum of overdosed patients, partly because of technical limitation, partly because of laboratory error, and possibly because of inadequate specimens. Drugs judged responsible for the overdose were identified in only 50% to 70% of the cases, depending on the laboratory. Reported concentrations sometimes varied over a 10-fold range.

Evaluation Studies as Topic↗
PubMed2006

Current status of digital mammography for screening and diagnosis of breast cancer.

PURPOSE OF REVIEW: Digital mammography is becoming the preferred technique for investigation of the breast. It is important, therefore, to analyze not only the accuracy of this technique in the screening and the diagnostic environment but also to evaluate its strengths and limits. In addition, communication with other specialists inside and outside the hospital is essential. RECENT FINDINGS: Recent publications of large clinical trials have shown that digital mammography is as accurate as film-screen mammography in a screening setting. Technical protocols for acceptance testing of these modalities are emerging but they are not yet complete. The literature shows that reading on soft copy may be preferred to hard copy. The high cost is still an important limiting factor in the easy introduction of full-field digital mammography in a hospital. SUMMARY: Digital mammography is becoming the method of choice in the detection and characterization of breast cancer. Today, physical and technical protocols as well as large clinical trials are assessing the performance of this technology. A lot of work remains in the optimization of the different parts of the imaging chain: exposure setting, acceptability of detectors, dedicated post processing, viewing conditions and computer-aided detection. In parallel with these developments, newer digital technologies are being explored (tomosynthesis).

Breast Neoplasms↗
PubMed2005

Determination of large bowel length and loop complexity in patients with acromegaly undergoing screening colonoscopy.

BACKGROUND: Patients with acromegaly are at moderately increased risk of developing colorectal cancer and may be considered for screening colonoscopy. In turn, large bowel dimensions may be increased in these patients, factors that predict for increased risk of serious complications such as perforation. OBJECTIVE: To evaluate this risk potential, we measured large bowel length and loop complexity using magnetic endoscopic imaging (MEI). DESIGN: Case-control study in 25 unselected patients with acromegaly (mean age 56 years) vs. 41 nonacromegalic controls (mean age 60 years) undergoing screening colonoscopy. MEASUREMENTS: MEI parameters were determined and age- and sex-adjusted mean differences calculated. The dependency of total large bowel length on various demographic and disease-related factors (e.g. GH exposure, IGF-I and IGFBP-3 concentrations) was assessed using regression techniques. RESULTS: Total large bowel length was increased by 20%[95% confidence interval (CI) 9-31%] in patients with acromegaly compared with controls (unadjusted and adjusted; P-values < 0.001). Acromegaly was also associated with increased time taken to reach the caecum (P = 0.01) and increased pelvic loop complexities (5/25 vs. 1/41, Fisher's exact test: P = 0.03). Total large bowel length was predicted by age at colonoscopy (P = 0.003) and patient height (P = 0.03), but not by surrogate biochemical markers of disease activity. CONCLUSIONS: Acromegaly is associated with increased large bowel length and loop complexity making colonoscopy technically challenging, and theoretically increasing the risk of serious complications. Patients need to be counselled accordingly, and appropriate resources with experienced staff allocated.

Acromegaly↗
PubMed1981

Use of a dried blood spot in immunoreactive-trypsin assay for detection of cystic fibrosis in infants.

We assayed more than 5000 blood spots dried on filter paper and approximately 1000 serum samples for immunoreactive trypsin, with commercial reagents (Behring and Sorin). The assay procedures were modified so that newborn screening is technically feasible. Both kits are satisfactory for serum assay, but the Sorin materials are better adapted for blood spot analysis. Immunoreactive trypsin in blood spots rapidly decreases with specimen age, but is stable in frozen serum. Values for premature infants do not differ significantly from those for full-term babies. Children with cystic fibrosis were readily distinguished from those without, up to at least one year of age.

Blood Specimen Collection↗
PubMed2005

Population spectrum of ACADM genotypes correlated to biochemical phenotypes in newborn screening for medium-chain acyl-CoA dehydrogenase deficiency.

Medium-chain acyl-CoA dehydrogenase deficiency (MCADD) is the most frequent inherited defect of fatty acid oxidation, with a significant morbidity and mortality in undiagnosed patients. Adverse outcomes can effectively be prevented by avoiding metabolic stress and following simple dietary measures. Therefore, prospective newborn screening (NBS) is being proposed for this condition. However, technical validation of MCADD population screening and assessment of its overall benefit require broadening of the as-yet-scarce knowledge of the MCADD genetic heterogeneity unraveled by NBS and its phenotypic consequences. Here, we describe the entire spectrum of sequence variations occurring in newborns with MCADD in the population of Bavaria, Germany, in relation to the biochemical phenotype. Among 524,287 newborns, we identified 62 cases of MCADD, indicating a birth incidence of 1 in 8,456. In all of the 57 newborns available for analysis, two alterations within the MCADD gene (ACADM) were identified. The most prevalent alteration c.985A>G (Lys329Glu) occurred in 27 (47%) newborns in the homozygous and in 18 (32%) in the heterozygous state (63% of defective alleles). The mild folding variant c.199T>C (Tyr67His) was identified in nine individuals, six of them being compound heterozygous with c.985A>G (Lys329Glu). Neither of the prevalent alterations were found in the remaining nine newborns. A total of 18 sequence variations were identified; 13 of them were novel: eight missense mutations, one nonsense mutation, two splice variants, and two small deletions. The remaining five were previously reported in MCADD patients. The ACADM heterogeneity uncovered was larger as anticipated from previous c.985A>G (Lys329Glu) carrier screening data. In addition, we show that MCADD appears to occur as frequently in Turkish newborns as in the native German population. Our data validate that biochemical NBS for MCADD is a highly specific procedure for disease detection, with the identification of a significant share of milder biochemical phenotypes, such as c.199T>C (Tyr67His). These show statistically lower acylcarnitine markers, allowing us to distinguish subgroups within the spectrum of ACADM sequence variations that correlate to biochemical MCADD disease expression. Our data might provide technical and medical guidance for decision making in the worldwide efforts to introduce MCADD population screening.

Acyl-CoA Dehydrogenase↗
PubMed1991

A dipstick, dot-ELISA assay for the rapid and early detection of bladder cancer.

A mouse monoclonal antibody (CK1K10) specific for keratin was developed. Enzyme immunoassays (EIAs) were performed to detect keratin in urine samples using CK1K10 and anti-mouse IgG. A high degree of sensitivity and specificity was obtained in the detection of bladder cancer patients. A fast dot-ELISA was developed in which urine is applied onto nitrocellulose (NC) sheets or dipsticks. Dipsticks coated with urine samples can be stored at room temperature for more than 5 days and at -20 degrees C for more than 3 months without loss of efficiency. A high positive correlation was found between the fast dot-ELISA and other EIAs. The assay does not require sophisticated equipment nor highly trained technical staff and can be performed in less than 30 min. The keratin dot-ELISA could be a reliable screening test for the early detection of bladder cancer.

Animals↗
PubMed1977

Evaluation of the Gravlee Jet Washer using combined cell block/cytologic interpretations.

Two hundred patients at high risk for endometrial adenocarcinoma were screened using the Gravlee Jet Washer. Tissue obtained from the first 100 patients was processed by cell block technic alone; tissue from the second 100 patients was processed by cell block plus direct smear and Nucleopore filtration stained by the Papanicolaou method. All patients had histologic diagnosis by fractional curettage. Six of 12 patients with a tissue diagnosis of carcinoma were missed by the jet washer using the cell block technic alone. In the second 100 patients, no cases of cancer were missed using both cell block and cytologic technics. Technic and application of the jet washer in screening for endometrial carcinoma are discussed. We conclude that the Gravlee Jet Washer is a safe, effective screening tool which frequently may replace diagnostic curettage; however, if abnormal bleeding persists, curettage must be done.

Adenocarcinoma↗
PubMed1992

[Serological confirmation of HIV infections in hospital practice: analysis of indeterminate western blot results].

Among 770 Western blots for HIV-1 confirmation on sera from subjects at high risk for HIV infection, 4.3% (33 cases) were indeterminate. Isolated, stable, reproducible anti-gp 160 reactivity, highly suggestive of a nonspecific reaction, was found in 16% of cases. There were three other probably nonspecific patterns with anti-gp 160 and either anti-gp 41 or anti-gp 120 reactivities and thin, atypical bands. Two patterns with anti-p24 and either anti-gp 160 or anti-gp 120 reactivities were consistent with HIV-1 seroconversion. Reactivity directed solely against gag products was seen in 18% of cases. The repeat test, performed in 16 cases, showed an identical pattern in 3 cases, a modified pattern in 3 cases, negative results in 9 cases, and seroconversion in 1 case. No case of HIV-2 infection was detected. Indeterminate Western blot results reflect nonspecific reactivity in most instances but should nevertheless lead to the exclusion of technical artefacts, seroconversion, and HIV-2 infection.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Blood pressure measurements in epidemiological surveys--time to change?

Blood pressure recordings in epidemiological surveys are usually obtained by non-ambulatory, multiple one-occasion, manual sphygmomanometric measurements by trained observers in study participants subjected to standardized examination conditions. High validity and reliability of blood pressure measurements ensure the comparability of study results obtained in different places and at different times, and have a major impact on the detection of correlates and determinants of blood pressure and hypertension. A blood pressure measurement quality assessment was performed within the multi-center collaborative WHO-MONICA Project investigating results of 47 surveys from various geographic regions of the world. In an overall summary assessment, six out of these 47 surveys were found to have had major measurement problems which prohibited their further inclusion in collaborative analyses. Most of the problems were associated with observer-related factors. Therefore, it was contended that automatic blood pressure measurement devices might be able to reduce and abolish most of these "nuisance" factors. In 1995, we had the opportunity to simultaneously study two independent random samples of men and women, aged 45 to 64 years, from the city of Augsburg in Southern Germany. One sample was examined by 16 observers with a random zero sphygmomanometer (MONICA Augsburg), the other sample (J.A.P. Study) was examined by two observers with an invasively validated, automatic oscillometric device (boso Oscillomat). In both surveys, blood pressure was measured three times under similarly standardized conditions. comparing the blood pressure results of the two surveys, the intra-individual measurement variation tended to be slightly higher with the Oscillomat than the random zero, and the population mean blood pressures and hypertension prevalences were found to be significantly lower with the Oscillomat. We conclude that manual measurements of blood pressure by sphygmomanometer should not be indiscriminately replaced externally validated automatic devices. The imponderabilities of automatic devices with varying technical principles have to be assessed in epidemiological settings weighed against recognized disadvantages of sphygmomanometry before any recommendations can be given as to changing the present epidemiological practice.

Bias↗
PubMedDate not supplied

[Screening of deafness at birth (author's transl)].

The authors studied different parameters of the hearing test proposed to detect deafness among new-borns. These parameters belong to the technic of the test itself (intensity of stimulus, repetition of the test five minutes later, during the day and the following days, characters of the reactions) and to the infant (gestational age birth weight age, disease). They found that the noise in the resuscitation room and in the usual incubators is high and perhaps injurious. Following their own experience and the results published in France and abroad, they think that the test is difficult and cannot be generalised for the moment to all newborns.

Deafness↗
PubMed1988

Analytical and technical aspects of testing for drug abuse: confirmatory procedures.

Many laboratories are now performing urine drug testing for employers, governmental agencies, and other institutions. It is now recognized that presumptive positive screening results have to be confirmed by an analytical procedure based on a different chemical technique with greater than or equal sensitivity to the screening test. Thin-layer chromatography has been widely used for this; however, it is relatively insensitive for certain drugs, and it cannot satisfy the accuracy and precision requirements needed to determine threshold concentrations reliably. Gas chromatography-mass spectrometry is able to satisfy these threshold requirements and has become the method of choice for confirming initial immunoassay results.

Chemistry Techniques, Analytical↗
PubMed1993

Attitudes of women of childbearing age towards prenatal diagnosis in southeastern France.

The objective of this study was to explore women's attitudes towards prenatal diagnosis of trisomy 21 and to examine some of the factors possibly responsible for these attitudes before implementing in real practice serological screening of pregnant women at risk for trisomy 21. We carried out a telephone survey on a representative sample of women who had recently had a normal livebirth delivery in the Marseille district in 1990. The participation rate was 80 per cent and the average age of the mothers was 28.9 years. Among the 514 women interviewed, 78 per cent stated that they would ask for an amniocentesis for a 1 per cent risk of trisomy 21 at their next pregnancy. When adjusting for confounding factors, the decision to have or not to have an amniocentesis was found to depend not only on the women's attitude towards induced abortion, but also on their understanding of the risk involved and on the social context (knowing a handicapped child, discussion with the father). It also depended on the women's age and on what they knew about amniocentesis from the medical point of view. The risk of miscarriage can influence a woman's choice but this objection was not found to affect the women's decisions significantly in our survey. The data showed the existence of a high potential demand for fetal karyotyping.

Abortion, Therapeutic↗
PubMed1979

[Is breast cancer screening effective? (author's transl)].

Two groups of patients consisting of women with and without breast symptoms are compared. They were mammographed in the same institute under identical technical conditions. Carcinomas found by screening were considerably less advanced. The findings confirm the experience of numerous authors that screening improves the prognosis; applied tandem method--physical examination and mammography--is far from ideal, but represents at present the best method to reduce breast cancer mortality. The final conclusion is to intensify the screening programs.

Breast Neoplasms↗
PubMed1995

Cervical cancer screening with cervicography and cytology.

The results of colposcopy and directed biopsies were compared with the cytological findings and cervicography in 1539 asymptomatic outpatients undergoing routine cervical cancer screening in order to compare the accuracy of cervicography and cytology and to assess the potential benefits of the combination of both screening tests. With the new reporting criteria, cervicography looked less sensitive (53% vs. 56%; P = 0.718) and significantly less specific (97% vs. 98%; P = 0.040) than cytology. In comparison with cytology and at the expense of a recall rate of 9%, the combination of both screening tests and to an increase of the sensitivity (77% vs. 56%; P = 0.013) but also to a decrease of the specificity (95% vs. 98%; P < 0.0001) and of the positive predictive value (44% vs. 60%; P = 0.051). When the original reporting criteria were applied to cervicography, the combination of both screening tests led to optimal sensitivity and negative predictive value (100%, respectively) at the expense of an unrealistic recall rate of 20%. Consequently, cervicography should not be considered as an alternative to cytology for cervical cancer screening since its accuracy is not significantly better and its rate of technically defective tests is significantly higher. The combination of both methods increases the sensitivity of cervical cancer screening at the expense of a high recall rate, of which cost effectiveness has to be assessed.

Adolescent↗
PubMed1999

Improving cervical cytology screening in a remote, high risk population.

OBJECTIVE: To evaluate the use of the ThinPrep method to reduce rates of unsatisfactory Papanicolaou (Pap) smears in women in remote communities. DESIGN: Prospectively collected samples were split and screened conventionally and by ThinPrep at the Queensland Cytology Service. PATIENTS: Three hundred women having cervical smears taken by a Mobile Women's Health Service nurse or at the antenatal and sexual health clinics of a remote north Queensland community. MAIN OUTCOME MEASURE: Number of Pap smears reported as unsatisfactory for evaluation and requiring a repeat smear request. RESULTS: 17.3% of conventionally prepared smears were technically unsatisfactory, compared with 6.3% prepared with ThinPrep. The overall rate of unsatisfactory smears was only 4.3% when both ThinPrep and conventional smears were assessed for a combined report. CONCLUSION: A significant reduction in the proportion of unsatisfactory Pap smears is possible with the ThinPrep method. Targeted use of ThinPrep in communities with high rates of unsatisfactory smears may prove cost-effective.

Adolescent↗
PubMed2006

Virtual colonoscopy in the detection of colonic polyps and neoplasms.

First introduced in 1994, CT colonography (Virtual colonoscopy) has emerged as an accurate, non-invasive test that will likely play a future role in colorectal cancer screening. Over the past 3 years, there have been dramatic improvements in both hardware and software technology relating to CT colonography resulting in shorter scan times, enhanced user-friendliness and improved performance statistics. Published results show the accuracy of CT colonography to be comparable to conventional colonoscopy for detection of polyps >6mm in size with few false-positives. While many of the technical aspects of CT colonography have now been standardised current interest focuses on the development of faecal tagging agents to avoid full bowel catharsis and the use of low dose multislice CT acquisition to reduce patient radiation exposure. This chapter will summarise the development of CT colonography to date, document its published performance in detection of colorectal polyps and cancers, and review its current and potential future uses.

Colonic Neoplasms↗