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PubMed1996

Plethysmography: safety, effectiveness, and clinical utility in diagnosing vascular disease.

Plethysmography, a semiquantitative method of measuring segmental blood flow and velocity in the carotid and peripheral vascular systems, is safe, easy to perform, and inexpensive. Impedance, strain guage, air, and photoelectric plethysmographic methods are assessed in this publication for their relative safety, efficacy, and clinical utility in diagnosing vascular disease. Clinical evidence has demonstrated, for example, that oculoplethysmography is not a reliable screening test for carotid artery disease, particularly in bilateral disease and nonocclusive unilateral disease. Oculoplethysmography is thus no longer recommended for the diagnosis of carotid artery disease. Impedance, strain guage, and photoplethysmography methods can be used for the initial evaluation of acute and chronic venous insufficiency, although there is great variability in the reliability of these tests to predict venous disease in the presence of nonobstructive thrombi and comorbid conditions. Strain guage and photoelectric plethysmography can be safely used for the evaluation of peripheral arterial disease. But surgical candidates for arterial reconstruction and some venous disorders may require additional imaging such as duplex ultrasound, venography, or arteriography for anatomic information that is not elucidated by plethysmography. The plethysmographic techniques reviewed in this assessment, evaluating the ability to predict the presence of flow reduction in the carotid and peripheral circulations, are based on the technical performance of the tests as compared with a reference method. Establishing evidence-based conclusions proved difficult in light of biases such as nonrandomization, unstated patient selection criteria, poor followup of patients, and lack of blindness in some studies.

Humans↗

PubMed1994

[Early postoperative complications of rigid uretero-renoscopy: screening for iatrogenic vesico-ureteral reflux. 30 cases].

From April to September 1992, systematic screening for iatrogenic vesicoureteric reflux was performed in a series of 30 patients treated by rigid ureterorenoscopy. Most of these endoscopies were performed for renal stones using a Wolff Multiscope (7.5/12 F) without prior dilatation of the urinary tract. The study protocol was essentially based on pre- and postoperative retrograde and voiding cystography. The site and tone of the ureteric orifice and the compliance of the intramural ureter were also evaluated and the operating time was determined. Out of 33 ureteric endoscopies, only one case of type I pelvic vesicoureteric reflux was demonstrated following an operation with no particular technical problems. This rare and benign deferred complication draws attention to the potential consequences of rigid ureterorenoscopy on the vesicoureteric antireflux device.

Adult↗

PubMed2006

Breast MR imaging in women at high-risk of breast cancer. Is something changing in early breast cancer detection?

In the last few years, several papers have addressed the introduction of contrast-enhanced MR imaging for screening women at high risk for breast cancer. Taking in consideration five prospective studies, on 3,571 screened women with hereditary predisposition to the disease and 9,652 rounds, we found that 168 patients were diagnosed with breast cancer (155 screen-detected, eight interval, and five cancers excluded from analysis) with a detection rate per year of 1.7%. These cancers were small (49% equal to or less than 10 mm in diameter) but aggressive, 82% being invasive and 49% with histologic grade 3; however, only 19% of these invasive cancers were associated with nodal involvement. The pooled sensitivity was 16% for clinical breast examination, 40% for mammography, 43% for ultrasound, and 81% for MR. The positive predictive value (calculated on the basis of the number of invasive diagnostic procedures due to false positives) was 33%, 47%, 18%, and 53%, respectively. Aim of the present article is to present the historical development of MR imaging of breast tumors that made this application theoretically and technically possible, to explain what strategic problems we face in the presence of a hereditary predisposition to the disease, to review the main results of the published studies, and to outline open problems and future perspectives.

Breast Neoplasms↗

PubMed2000

Use of D-dimer assays in the diagnosis of venous thrombosis.

In the course of fibrin formation, the D-domains of adjacent fibrin molecules within the fibrin polymer are covalently linked by factor XIIIa, leading to the formation of a D-domain dimer. Proteolysis of this cross-linked fibrin generates fibrin fragments D-dimer and E as terminal products. Fragment D-dimer therefore is an indicator for the proteolysis of cross-linked fibrin, whereas the monomeric fragment D can stem from fibrinogen and non-cross-linked fibrin. Various monoclonal antibodies have been prepared that distinguish between fragments D-dimer and D and allow the detection of fibrin derivatives in the presence of fibrinogen. These anti-D-dimer-antibodies have been shown to react with fragment D-dimer, but also detect dimeric D-domains within larger fibrin compounds, including cross-linked fibrin complexes generated in an early phase of coagulation activation. Assay systems for D-dimer antigen therefore may uncover intravascular clot formation early, by detection of fibrin complexes, and after completion of clot formation, by the detection of proteolytic fragments released from the particulate clot. Various trials have shown that low concentrations of D-dimer antigen in the blood exclude recent venous thrombosis or pulmonary embolism. Elevated levels may be caused by venous thrombotic disease, but also by a variety of other conditions, leading to intra- or extravascular fibrin formation. Assay systems include manual immunoagglutination assays, immunofiltration assays, microtiter plate enzyme-linked immunosorbent assay (ELISA) systems, automated ELISA systems, and latex-enhanced photometric immunoassays. According to clinical studies, D-dimer assays may be the "first line" of technical screening in symptomatic outpatients with suspected venous thrombosis or pulmonary embolism, but further prospective management trials, and improved standardization of assay systems, are needed for the validation of this approach.

Antifibrinolytic Agents↗

PubMed1991

Breast sonography.

Sonographic equipment for breast imaging has continued to improve, and the role of breast sonography has evolved to that of an indispensable adjunct to mammography. Breast sonography is not useful for screening for breast cancer in any age group. Its main use is for the differentiation of cystic vs solid palpable and mammographically visible masses. If strict sonographic criteria are used for a simple cyst, the diagnostic accuracy approaches 100%. Sonographic diagnosis of a simple cyst precludes the need for further workup, including aspiration, biopsy, or followup. This article emphasizes the technical aspects of breast sonography, especially those factors that alter the diagnostic information on the images. These factors can be especially problematic in differentiating cysts and solid masses, the most common diagnostic use of breast sonography. Selection of equipment depends largely on the requirements of a specific practice. Optimally, the sonographic equipment is located close to where mammography is performed, and the sonographic and mammographic findings are interpreted together.

Breast Neoplasms↗

PubMed1991

The use of cervicography in a primary screening service.

The cervicography and concurrent endocervical brush smear results obtained in 1162 women screened at the Marie Stopes Clinic were analysed. Colposcopy and biopsy results were obtained for positive cases. A comparison was made with a group of 1007 women attending the same clinic for routine cytology only. Nearly 10% of women who were screened by cervicography had a technically defective cervicogram, the main single reason being that the view was obscured by blood. Routine cytology was positive in 1%, while cervicography was positive in 13%, where positivity was defined as a result leading to a recommendation for colposcopy. The false positive rate for cervicography was 26%. Even after adjustment, this difference was highly significant (P less than 0.0001).

Acetates↗

PubMed2003

[Evaluating the effectiveness of child lead poisoning prevention programs].

PROBLEM: A multi annual screening and prevention program against lead poisoning was implemented in a suburb of the Paris area. We attempted to assess the effectiveness of this program based on data available from children screening and follow-up. METHODS: Indicators of effectiveness included the evolution of blood lead levels at screening and the frequency of secondary increases in blood lead levels. Buildings inclusion dates were used to control for the increasing selection of less exposed children. RESULTS: A total of 3,660 children were screened between 1992 and 2000. We observed a regular decrease in blood lead levels at screening, in the highest blood lead levels obtained for each child and in the proportion of children whose blood lead levels increased after screening: the proportion of children with initial blood lead levels >=15 micro g/dl fell from 17.4% in the 1992-1996 period to 4.1% in the 1997-2000 period. A multivariate analysis taking into account the first year that children were screened in a given building showed that less exposed children were included over time, but found also an additional independent decrease in blood lead levels that can be related to the effectiveness of prevention efforts. A "building by building" analysis of 30 buildings where more than 20 children were located over the whole study period confirmed that the incidence of lead poisoning decreased within most of these buildings. CONCLUSIONS: Taking into account buildings'inclusion dates makes it possible to distinguish program effectiveness from the consequences of including less exposed children The effectiveness of preventive actions is associated with several interacting factors, including the participation of families and the active involvement of local technical staff and policy makers. The finding that the decrease in blood lead levels leveled off after 1997 calls for further actions.

Child↗

PubMed2005

[Which is the most appropriate diagnostic algorithm for prostate cancer screening?].

Since the use of PSA to detect prostate cancer was generalised in the late 1980's, prostate cancer diagnosis has increased considerably. Although there is now indirect evidence pointing to the beneficial effect of screening, there are no data justifying PSA screening in the general population. There is also a controversy concerning the most appropriate algorithm, should screening be performed. Therefore, our aim was to review the literature and, based on our experience, attempt to define the best algorithm for prostate cancer screening. We have made a search on Medline using the following terms: prostate biopsy, screening, algorithms, radical prostatectomy, PSA and prostate cancer. After analysing the literature, we can confirm that there is no "definitive" algorithm, due to the rapid appearance and use of new technical and biological breakthroughs, although it appears that at this time, without ceasing to include a rectal examination, more value should be given to personal risk factors, including PSA, at ages under 50, with individual monitoring based on these factors. The algorithms applied to a population have first to be validated for the population concerned.

Algorithms↗

PubMed2006

HIV testing in 2006: issues and methods.

Infection with HIV and subsequent development of AIDS is a pandemic. The Joint United Nations Program on HIV/AIDS together with the WHO and many relevant funding bodies demand that those infected should be reliably identified so that people who need, or will need, therapy may be provided for over time. This means that there is a renewed interest in testing for HIV and in laboratories' performances and quality. Whatever the conditions under which testing is performed, and whatever the levels of training, the tests and their outcomes must exhibit equivalent, high standards of performance and reliable results. This is regardless of whether testing is conducted in the most sophisticated laboratories (either diagnostic or transfusion screening) to voluntary testing and counseling centers where those conducting testing may not be technically trained. This is not currently the case, especially in some places where HIV is most prevalent. To achieve uniformly high performance standards, quality assurance programs are imperative, but currently not sufficiently valued to be well supported with adequate funding or human resources. Accurate HIV testing is a cornerstone of blood safety, diagnosis of infection, patient management and surveillance.

Animals↗

PubMed1994

Isolation of clones of rat striatum-specific mRNAs by directional tag PCR subtraction.

We report an improved subtractive cDNA cloning procedure, named "directional tag PCR subtraction," for isolating clones of mRNAs enriched in a target tissue compared to a second tissue, the driver. In this method, the target and driver are prepared from directional cDNA libraries constructed in different vectors, and the target cDNA contains tag sequences at both its 5' and 3' ends for PCR amplification. This method avoids several limitations of previous subtraction procedures, and was demonstrated to be technically easy and efficient. Using the directional tag PCR subtraction and improved screening procedures, cDNA clones corresponding to mRNAs expressed in the striatum but not in the cerebellum of the rat brain were efficiently isolated, including mRNAs encoding calmodulin-dependent phosphodiesterase, a transcriptional regulatory protein, and several previously uncharacterized species. Our data suggest that approximately 1% of the striatal polyA+ RNA mass potentially encoding more than 300 distinct proteins corresponds to RNA species reduced in concentration or absent from the cerebellum, of which about one-third are expressed prominently only in the striatum. This unexpected finding suggests that the striatum has a unique biochemical character within the brain, and that characterization of these mRNAs will be important for understanding the biochemical basis of striatal function.

Animals↗

PubMed1985

Evaluation of the cerviscope as a screening instrument.

The cerviscope has been proposed as a screening tool for use in conjunction with the Papanicolaou smear as a system offering many of the same advantages as colposcopy and cytology. One hundred twenty-five patients were evaluated with the cerviscope who had been referred to this colposcopy clinic with a diagnosis of dysplasia. The purpose of this study was to evaluate the instrument's potential as a screening adjunct in the context of simultaneous evaluation by colposcopy. Thirty-nine percent (49 patients) were unevaluable due to technical problems (defective cervicogram, nonvisualized squamocolumnar junction). Significantly, 67% (26 patients) of the 39 patients reported as having negative cervicograms had a biopsy-proven dysplasia (19 mild, 4 moderate, 3 severe). By the chi 2 method, this is statistically significant (P less than 0.001).

Adult↗

PubMed1978

Screening for lower extremity deep venous thrombosis. An improved plethysmographic and Doppler approach.

Noninvasive screening of the lower extremities for deep vein thrombosis was performed bilaterally on 1,118 patients. Impedance plethysmography alone was used in 868. Venography in 135 revealed an accuracy of 88%, with a false-negative rate of 5.3% and a false-positive rate of 18.6%. A combined ultrasonic Doppler and modified impedance technic was used in 250 patients. Venography in forty revealed an accuracy of 95%, with a false-positive rate of 10% and no undetected thrombi. The combined technic, emphasizing the more accurate modality in three anatomic areas, has proven sensitive, specific, and reliable as a screening test for deep venous thrombosis.

Doppler Effect↗

PubMed1995

Technical note: dual compression mammography using computed radiography.

On mammography most malignant growths may be seen as a tethered mass or architectural distortion. Benign lesions such as cysts and fibroadenomas have no focal tethering and are usually well circumscribed. Computed radiography (CR) is a direct digital system which may be used for mammography. One of the main advantages of CR is its wide exposure latitude allowing images to be acquired at lower exposures than required for film-screen systems. A technique was developed, utilizing the exposure latitude of CR, to acquire two mammograms of the same breast at two slightly different compressions, but using approximately the same exposure as a single film-screen mammogram. These images were then "animated" on a computer allowing the fibrous septa movement to be visualized. The movement of the fibrous septa in the presence of an abnormality was used to help confirm whether a lesion was benign or malignant. This technique may have clinical application in classifying architectural distortions and masses which are ultrasonically benign but later found to be malignant. Microcalcifications cannot be used as a diagnostic indicator with this technique because of the increased noise associated with the lower exposures. The increased noise did not affect the visualization of masses.

Breast Neoplasms↗

PubMed2006

A simple parallel analytical method of prenatal screening.

Protein microarray has progressed rapidly in the past few years, but it is still hard to popularize it in many developing countries or small hospitals owing to the technical expertise required in practice. We developed a cheap and easy-to-use protein microarray based on dot immunogold filtration assay for parallel analysis of ToRCH-related antibodies including Toxoplasma gondii, rubella virus, cytomegalovirus and herpes simplex virus type 1 and 2 in sera of pregnant women. It does not require any expensive instruments and the assay results can be clearly recognized by the naked eye. We analyzed 186 random sera of outpatients at the gynecological department with our microarray and commercial ELISA kit, and the results showed there was no significant difference between the two detection methods. Validated by clinical application, the microarray is easy to use and has a unique advantage in cost and time. It is more suitable for mass prenatal screening or epidemiological screening than the ELISA format.

Dose-Response Relationship, Drug↗

PubMed2005

Brain injury and proteomics/peptidomics: is it relevant? an overview.

Proteomics and peptidomics are different and supplemental to genomics, since in contrast to the basically constant genome - the proteome and peptidome are dynamic, constantly changing, and complex networks. Proteomics is traditionally linked to 2D-gel electrophoresis techniques. Concerning peptidomics, three different approaches are currently available, all using mass spectrometry as a key element. The use of proteomics or peptidomics in traumatic brain injury (TBI) research is demanding. From the technical point of view there are high-level requirements concerning the preanalytical phase, specific machinery, sophisticated software and skilled manpower/intellectual input. There are currently no bedside techniques and most methods are suitable for experimental TBI research in specialized laboratories. In screening experiments of CSF following controlled cortical impact in rats we identified several peptides, which, although previously known, were so far not reported in the TBI context or in CSF. Peptidomics and proteomics, as highly complex screening technologies, thus seem to carry a large potential to lead TBI science. Newly "discovered" peptide targets have to be validated with different methodology to establish a real diagnostic or therapeutic value.

Animals↗

PubMed1978

Vision screening in children tested at 7, 11, and 16 years.

Distant vision screenings of a national sample of children were performed at the ages of 7, 11, and 16. Many children with normal vision at one screening showed defects at later screenings, and altogether 18% of children with normal vision at the age of 7 had defects by the time they were 16. Twelve per cent of those with normal vision at 7 and 11 had developed a visual defect by the age of 16. Apparent improvements between screenings probably resulted largely from technical difficulties inherent in testing young children. The results clearly indicate the importance of regular vision screening during the school years and the need for comprehensive but flexible back-up services.

Adolescent↗

PubMed2006

Validity of an alternative anthropometric trait as cardiovascular diseases risk factor: example from individuals with traumatic lower extremity amputation.

BACKGROUND: Published studies reveal that individuals with lower extremity amputation are vulnerable to cardiovascular diseases (CVD) because of poor physical activity level. Many cardiovascular risk assessment studies have utilized anthropometric traits (primarily body mass index and waist circumference) as cardiovascular risk factor. However, some studies emphasized the technical limitations of measuring waist circumference for studying cardiovascular risk, and so it is difficult to obtain correct measurement from the individuals with lower extremity amputation. OBJECTIVES: The objectives of the present article are to study the prevalence of CVD risk factors among the individuals with traumatic lower extremity amputation and to test the validity of upper arm circumference (UAC) as an alternative anthropometric measurement for screening the CVD risk condition. SUBJECTS AND SETTING: Anthropometric data and other cardiovascular traits data have been collected from unilateral traumatic lower extremity amputated adult males (n = 85) residing in Calcutta and adjoining areas. RESULTS: Results show higher prevalence of cardiovascular risk factor among individuals with above-knee amputation than below-knee amputation. The receiver operating characteristics curve analysis shows significant ability of upper arm circumference to diagnose cardiovascular risk condition. The cutoff value of UAC > 26.6 cm show maximum sensitivity and specificity for the diagnosis of cardiovascular risk condition. Although, binomial tests for equality of proportion does not show any significant difference, however, agreement statistics reveal better diagnostic ability of cutoff value of UAC than the existing cutoff value of waist circumference. CONCLUSIONS: Therefore, UAC provides a better assessment of cardiovascular risk condition than does waist circumference especially for individuals with lower extremity amputation. SPONSORSHIP: Indian Statistical Institute, Kolkata.

Adult↗

PubMed1988

Space Station atmospheric monitoring systems.

A technology assessment study on atmospheric monitoring systems was performed by Battelle Columbus Division for the National Aeronautics and Space Administration's John F. Kennedy Space Center under Contract No. NAS 10-11033. In this assessment, the objective was to identify, analyze, and recommend systems to sample and measure Space Station atmospheric contaminants and identify where additional research and technology advancements were required. To achieve this objective, it was necessary to define atmospheric monitoring requirements and to assess the state of the art and advanced technology and systems for technical and operational compatibility with monitoring goals. Three technical tasks were defined to support these needs: Definition of Monitoring Requirements, Assessment of Sampling and Analytical Technology, and Technology Screening and Recommendations. Based on the analysis, the principal candidates recommended for development at the Space Station's initial operational capability were: (1) long-path Fourier transform infrared for rapid detection of high-risk contamination incidences, and (2) gas chromatography/mass spectrometry utilizing mass selective detection (or ion-trap) technologies for detailed monitoring of extended crew exposure to low level (ppbv) contamination. The development of a gas chromatography/mass spectrometry/matrix isolation-Fourier transform infrared system was recommended as part of the long range program of upgrading Space Station trace-contaminant monitoring needs.

Air Conditioning↗