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Results for “MASS SCREENING TECHNICS”

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PubMed1976

Standardization fo a digestion-filtration method for isolation of pancreatic islets.

Standardization of a technic for isolating large numbers of pancreatic islets is described. This procedure employed collagenase digestion of rat pancreatic tissue in a cylindrical wire screen in order to separate isolated islets from undigested pancreas. From this basic protocol the following conditions were established: (1) the duration of the initial digestion period was found to be optimal at six minutes; (2) three subsequent digestions of one minute each effected maximum islet yield; (3) the optimal initial collagenase concentration was found to be 1,000 U. (Worthington)/ml.; and (4) proper reductions of collagenase concentrations during the three subsequent digestions were found to be 50 per cent of each preceding incubation period. This method, combined with Ficoll gradient separation, yielded a mean of 800 islets per two rat pancreases. The isolated islets appeared morphologically intact, contained 0.36 +/- 0.05 mug. protein/islet, and demonstrated a normal biphasic release of insulin in response to stimulative levels of D-glucose. The present method provides a means for obtaining a large mass of viable islet cell tissue in a short time.

Animals↗

PubMed1977

[Prescreening methods for gynecological cytology (author's transl)].

In cytological investigations to trace gynecological cancer a large number of preparations must be examined in order to discover a small number of positive and suspicious findings. In 1974, 5.5 million investigations were carried out in the German Federal Republic, of which 2% positive, 9.2% suspicious and 2.4% technically useless cytological results were obtained. 98.64% of the cytological results were negative. Consequently in different parts of the world efforts are being made to automate the preliminary microscopic sampling of the cytological preparations. False negative cytological findings must be no higher than in conventional diagnosis (without extraction error approximately 5%), while false positive cytological findings (in conventional diagnosis less than 1%) may be higher, because they can be classified correctly on subsequent assessment.

Adolescent↗

PubMed1995

[Trend of tuberculosis among young people observed from data of nationwide surveillance system].

In order to know the trend of TB incidence among people younger than 30 years of age, and to clarify the problem of TB control among them, the author used the surveillance data, the vital statistics, the annual reports of health center activities and others for the past 20 years. While the stagnation of the decline of TB incidence rate has been observed since early 1980s, the speed of decline among young people has been greater than that among people older than 30 years. However, at the same time it is worth attention that the incidence rate of the 20s is higher than that of those aged 30-39 years, and the slowing off more remarkable, during the last several years. It was shown that the recent increase of young immigrants from high prevalence countries is affecting the incidence of young age group (age 20-29) in Tokyo and the surrounding prefectures with higher proportion of these immigrant population. On the other hand, the high incidence in the young people observed in Osaka and the surrounding prefectures may be attributed to some other social risks. The BCG coverage for children aged 0-4 years has been increasing and reached to 90% in 1991. The tuberculin test results of children in an area seems to reflect the technical level of the testing and the age of children to be tested, rather than the TB prevalence of the area. The frequency of the young people under chemoprophylaxis is widely variable among prefectures. There is poor correlation between this frequency of chemoprophylaxis of prefectures and the incidence rate of sputum positive TB, which may be caused by disparity in recognition of the necessity of the chemoprophylaxis and the lack of efforts for the quality control of the services, such as tuberculin testing.

Adolescent↗

PubMed2005

Emerging technologies in colorectal cancer screening.

CRC is a preventable disease through early detection, yet screening rates remain low and mortality rates remain high. The discomfort associated with the preparation and performance of some of the currently available screening modalities and the lack of public awareness about CRC and screening procedures likely account for low rates of screening. CT colonography and stool DNA testing are new promising screening technologies that are less invasive, accurate, and suitable for the public more than the current screening procedures. Before both tests can be promoted for population-based screening programs, several issues that have been detailed in this article must be addressed further, including technical improvements for improving accuracy, development of virtual preparation, test availability, patient and provider acceptability and cost-effectiveness for CTC, and identifying the optimal combination of molecular targets for stool DNA testing. The year 2005 will tell us if the ideal technology from the public health point of view was achieved. A skill-independent, anesthesia-free, self-propelling, self-navigating miniaturized endoscopic device that may move along the entire length of the colon may change the natural history of CRC. We should aim to achieve a new definition of CRC--a rare disease occurring in a subset of the population who has not been screened for the disease.

Colonoscopy↗

PubMed1993

Thyroid disease in pregnancy. ACOG Technical Bulletin Number 181--June 1993.

To accurately evaluate thyroid disorders in pregnancy, the physician must understand the physiologic changes that occur both in thyroid gland size and in thyroid function tests. The effect of thyrotoxicosis on pregnancy outcome largely depends on whether metabolic control is achieved. Women who become euthyroid on treatment usually can expect satisfactory outcomes. Propylthiouracil is considered to be the drug of choice for treating thyrotoxicosis during pregnancy. Because of the significant risk of hypothyroidism and obvious goiter in the infant, the use of iodide should be reserved for severe disease, such as thyroid storm or heart failure. Thyrotoxic infants may need antithyroid treatment until TSAbs are metabolized. Since overt hypothyroidism is often associated with infertility, it is uncommon in pregnancy. Hypothyroid women who do become pregnant, however, have an increased risk of low-birth-weight or stillborn infants. These women may require a greater dosage of thyroid hormone during pregnancy. The effects of subclinical hypothyroidism are not well defined. Accordingly, the need for treatment hinges on the woman's clinical history. Infants of hypothyroid mothers usually show no evidence of thyroid dysfunction, but those who are hypothyroid should receive prompt thyroid replacement therapy. To minimize the sequelae of congenital hypothyroidism, mass screening of infants and prompt treatment of those affected is recommended. During pregnancy, thyroid nodules should be evaluated by ultrasound and fine-needle aspiration or tissue biopsy. Radioiodine scanning should be avoided during pregnancy. If thyroid cancer is diagnosed, pregnancy should not delay treatment. Because postpartum thyroid dysfunction is fairly common yet difficult to detect, physicians and patients should be aware of the symptoms and risk factors.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1997

Automatic segmentation, tissue characterization, and rapid diagnosis enhancements to the computed tomographic colonography analysis workstation.

An image processing system developed to support examination of computed tomographic colonoscopy (CTC) was developed in 1995. The clinical viability of CTC is enhanced by the solution of several technical problems. These problems include the limited detectability of sessile polyps and difficulties in discrimination between polypoid masses and retained stool. CTC is also made more feasible by simplifying the required colon preparation and reducing the time required to analyze scan results. Each of these challenges have been addressed by enhancements to the CTC analysis workstation software. Endoluminal volume rendering has been enhanced by the addition of automatic segmentation to facilitate analysis of colon segments, which contain tagged liquid stool. By automating this function, the system is able to process scans that are acquired following a wide variety of colon preparation protocols. Similar approaches have been used to identify retained stool. Automatic tissue characterization has also been incorporated into the volume rendering routines to help identify and diagnose polypoid masses. These enhancements have improved the quality of CTC interpretation, while reducing the time required to perform the analysis. This time reduction was necessary to reduce the cost of CTC enough to make it viable for asymptotic population screening. To date, over 150 patient examinations have been performed using this new technique. A recent blinded, prospective study reporting the results from two independent observers has been presented. The technique is feasible, reliable, and has been implemented clinically with results reported within 1 hour of the examination.

Colon↗

PubMed1999

Scientific uncertainty and the role of expert advice: the case of health checks for coronary heart disease prevention by general practitioners in the UK.

This paper examines some of the ways in which scientific evidence influenced the development of the policy for the payment of general practitioners for coronary heart disease (CHD) prevention in the UK, in particular the introduction of 'health checks'. The specific policy events which are examined are the 1990 and 1993 contracts for health promotion by general practitioners. Data for this paper were provided by oral history interviews with key informants including general practitioners, public health doctors, civil servants and academics. The study shows the way in which complex scientific evidence interacted with other, professional and political, factors to produce a policy for which there was variable scientific evidence. The relationship between science and policy was complicated and tortuous but two aspects were particularly salient, the way in which scientific uncertainty influenced the content of the policy and the contribution of expert advice to policy making. The existence of social and technical uncertainty about the effectiveness of health checks allowed different players to hold different views depending on their professional affiliation or other agendas. The mechanisms by which scientific advice was given to policy makers were primarily by medical civil servants and through informal contacts and networks. There was no independent systematic formal system to assess and disseminate scientific advice to policy makers, for instance by an expert committee. These factors in turn allowed policy makers to ignore or misinterpret scientific evidence according to other policy imperatives.

Coronary Disease↗

PubMed2004

Total body water measurements using resonant cavity perturbation techniques.

A recent paper proposed a novel technique for determining the total body water (TBW) of patients suffering with abnormal hydration levels, using a resonant cavity perturbation method. Current techniques to measure TBW are limited by resolution and technical constraints. However, this new method involves measuring the dielectric properties of the body, by placing a subject in a large cavity resonator and measuring the subsequent change in its resonant frequency, fres and its Q-factor. Utilizing the relationship that water content correlates to these dielectric properties, it has been shown that the measured response of these parameters enables determination of TBW. Results are presented for a preliminary study using data estimated from anthropometric measurements, where volunteers were asked to lie and stand in an electromagnetic screened room, before and after drinking between 1 and 2 l of water, and in some cases, after voiding the bladder. Notable changes in the parameters were observed; fres showed a negative shift and Q was reduced. Preliminary calibration curves using estimated values of water content have been developed from these results, showing that for each subject the measured resonant frequency is a linear function of TBW. Because the gradients of these calibration curves correlate to the mass-to-height-ratio of the volunteers, it has proved that a system in which TBW can be unequivocally obtained is possible. Measured values of TBW have been determined using this new pilot-technique, and the values obtained correlate well with theoretical values of body water (r = 0.87) and resolution is very good (750 ml). The results obtained are measurable, repeatable and statistically significant. This leads to confidence in the integrity of the proposed technique.

Anthropometry↗

PubMed1998

[Rational radiologic diagnosis of breast carcinoma].

For a favourable prognosis breast cancer must be diagnosed as early as possible. Among available imaging modalities (mammography, sonography, DAS, thermography, CT, MR) only mammography has been shown to produce a significant reduction in mortality, but unfortunately only for women above 50 years of age. The technical requirements, and the standard techniques and the appearance of benign and malignant breast tissues are described. The routine use of ultrasound in the evaluation of palpable masses remains controversial. Ultrasound technology is incapable of detecting early-stage cancers reliably. By "using dynamic MRM", i.e., repetitive imaging of the same slice before and at short time intervals after the injection of a contrast medium, high sensitivity and specificity is achieved in detecting breast cancer of different histologies. MR-mammography should be used in all cases where there is a discrepancy among radiographic, sonographic or clinical findings.

Adult↗

PubMed2004

Methodological and technical issues related to the diagnosis, screening, prevention, and treatment of pre-eclampsia and eclampsia.

In contrast with advances made in treating or eliminating many other serious disorders, severe morbidity and mortality associated with pre-eclampsia/eclampsia remain among the leading problems that threaten safe motherhood, particularly in developing countries. This article reviews technical issues related to diagnosis, screening, prevention, and treatment of pre-eclampsia and identifies corresponding needs. The authors stress the lack of standardized definitions of pre-eclampsia and eclampsia and discuss problems in blood-pressure measurements and assessment of urinary protein. They summarize the evidence for prevention strategies and screening tests for early detection. For treatment, magnesium sulfate has been proven effective, but not widely used. The authors outline priorities for narrowing the identified gaps and emphasize the need for coordinated efforts to reduce the morbidity and mortality due to pre-eclampsia/eclampsia. They conclude that the mystery of this disease must be resolved to achieve primary prevention of it.

Developing Countries↗

PubMed1987

[Ambulatory ECG during screening phase in relation to other technics in patients with precordial pain].

Screening of patients with precordial symptoms is a mayor social problem. Holter monitoring is easy to use because it ambulatory, non invasive, can be repeated without harm, has no contraindications and permits prolonged monitoring. Therefore, it seemed necessary to determine the "role" of this test. We examined all of the Holter monitorings performed in Dynamic electrocardiographic laboratory of the S. Matteo Polyclinic from 1983 to 1986. 480 of the 3365 patients visited, presented precordial symptoms. 162 patients (group A) had established ischemic heart disease (old myocardial infarction and/or coronary arteriography). 318 patients (group B) had no definite diagnosis. 71 subjects from group A and 140 from group B presented a typical symptomatology. Group A showed a 31.48% positivity during the test with 165 ischemic attacks. Group B had 25.15% positivity with 397 ischemic attacks. 51 symptomatic attacks (30%) were recorded for group B. Therefore, there was a mayor incidence of silent ischemic heart disease in both groups. Results obtained comparing Holter monitoring to the bicycle ergometry exercise test and to functional test, were comparable in 56.91% (sensibility 41.71% and specificity 78.62%) in the first case and 61.38% (sensibility 42.50% and sensitivity 73.77%) in the latter. In conclusion, we believe that Holter monitoring is useful in mass screening because it permits monitoring of most ischemic attacks, whether under stress or at rest, symptomatic or silent.

Aged↗

PubMed1997

Video colpography: a new technique for secondary cervical screening.

OBJECTIVE: To assess the diagnostic accuracy of a new technique of cervical imaging and to consider its potential as a secondary cervical screening method. DESIGN: A prospective cross-sectional study with each case acting as its own control, comparing video colpography with colposcopy. SETTING: University of Birmingham colposcopy clinics, City Hospital and Birmingham Women's Hospital. PARTICIPANTS: Fifty women referred for colposcopy. INTERVENTIONS: The women had a video colpogram recording made prior to colposcopy. MAIN OUTCOME MEASURES: The proportion of technically suitable colpograms obtained and the level of agreement between colposcopist and video screener. RESULTS: The images were satisfactory or good in 94% cases, and there was a very high level of agreement between colposcopist and video screener (kappa = 0.79). If the technique had been used in a primary health care setting as a secondary screening method for women with low grade cervical smear abnormalities, 61% would have avoided referral for colposcopy. CONCLUSIONS: Video colpography is an accurate, portable and quick method of cervical imaging. It combines the simplicity of a video camera with the versatility of computerised digital imaging and has great potential in the fields of teaching, audit and screening of low grade smear abnormalities.

Colposcopy↗

PubMed2006

Preoperative evaluation of the "hostile pelvis" in radical prostatectomy with computed tomographic pelvimetry.

OBJECTIVE: To determine whether preoperative pelvimetry based on computed tomography (CT) can be used to predict technical difficulties during open radical prostatectomy (RP). PATIENTS AND METHODS: An open RP database accrued prospectively between January 1997 and June 2005 was used to identify 450 patients with preoperative pelvic imaging. Of these, 165 had adequate imaging of the pelvis with CT to allow pelvimetry using software provided with the medical imaging records. Several pelvic measurements were recorded in conjunction with body mass index and transrectal ultrasonographic estimates of prostatic volume. Outcome measures used to reflect technical surgical difficulties included operative duration, blood transfusion requirements within 30 days of RP, the pathological positive surgical margin and prostatic capsular breech rate. Logistic and linear regression analyses were used to determine the relationship between variables before and after RP. RESULTS: The selected pelvimetric measurements failed to predict either operative duration or the peri-operative blood transfusion requirement. Prostatic volume was predictive of operative duration; for every increase of 20 mL in prostate volume the duration increased by 8.4 min. Although pelvimetric measures failed to predict positive surgical margins at pathology, the transverse diameter predicted the likelihood of a positive margin due to capsular breech. With every 8.6 mm (1 sd) decrease in transverse diameter, the odds of a capsular breech resulting in positive surgical margins increased 5.3 times (95% confidence interval 2.1-20.0, P = 0.002). CONCLUSIONS: Although the "hostile pelvis" influences the likelihood of prostatic capsular breech resulting in positive surgical margins, CT pelvimetric screening of patients before RP is unlikely to be cost-effective. Routine pelvic CT in the evaluation of patients before RP is not supported.

Aged↗

PubMed1997

Randomised trials of STD treatment for HIV prevention: report of an international workshop. HIV/STD Trials Workshop Group.

Three community trials of the impact of STD treatment interventions on HIV incidence in rural populations have been completed or are in progress in Uganda and Tanzania. Investigators from these trials met for a joint technical workshop in Baltimore in May 1996. This report summarises the consensus of the workshop, with the aim of providing useful input to research on HIV intervention strategies. Issues discussed include: (i) the role of community randomised trials; (ii) strategies for STD management; (iii) epidemiological and statistical issues in the design and analysis of community randomised trials; (iv) diagnostic methods for STDs in population surveys; (v) treatment regimens for STDs in rural Africa; and (vi) ethical issues in community trials.

Community Health Services↗

PubMed2003

The $1000 genome: ethical and legal issues in whole genome sequencing of individuals.

Progress in gene sequencing could make rapid whole genome sequencing of individuals affordable to millions of persons and useful for many purposes in a future era of genomic medicine. Using the idea of $1000 genome as a focus, this article reviews the main technical, ethical, and legal issues that must be resolved to make mass genotyping of individuals cost-effective and ethically effective. It presents the case for individual ownership of a person's genome and its formation, and shows the implications of that position for rights to informed consent and privacy over sequencing, testing, and disclosing genomic information about identifiable individuals. Legal recognition of a person's right to control his or her genome and the information that it contains is essential for further progress in applying genomic discoveries to human lives.

Adult↗

PubMed1992

A mammographic screening pilot project in Victoria 1988-1990. The Essendon Breast X-ray Program Collaborative Group.

OBJECTIVE: To pilot and evaluate the feasibility and acceptability to women of population based mammographic screening in Victoria. DESIGN: Pilot intervention study in a geographically and demographically defined population. SETTING: Area of contiguous postcodes surrounding the Breast X-ray Unit at the Essendon Hospital. TARGET POPULATION: Women aged 50 to 69 years living in the target area. MAIN OUTCOME MEASURES: Attendance rates, satisfaction, screening rates, surgical biopsy rates, breast cancer detection rates, and surgical treatment. RESULTS: Forty-one per cent of eligible women in the denominator population attended the Breast X-ray Unit in the two-year period; 16,424 women were screened, including 141 women with previous breast cancer. Of every 1000 women screened, 74 were recalled because of mammograms that were suggestive of malignancy, 19 because of technically inadequate mammograms and 16 because of symptoms. All mammograms were read by two radiologists and consensus was required for 12% of films. Of every 1000 asymptomatic women screened, 12.7 had biopsies performed and in 7.1 cancers were detected. In asymptomatic women, the positive predictive value of an abnormal mammogram was 9.4%, and the positive predictive value of a recommendation for biopsy was 55.9%. A total of 131 malignancies were detected, of which 24 (18%) were carcinoma-in-situ. The benign to malignant biopsy ratio was 1:1.31. In 82% of women in whom cancer was detected the breast was conserved. CONCLUSIONS: The Program achieved good standards with respect to mammographic detection, clinical assessment and treatment of women with breast cancer.

Aged↗

PubMed1985

Occult blood screening for colorectal carcinoma: a critical review.

The author reviews the literature on occult blood surveillance for colorectal carcinoma. The guaiac-based Hemoccult (SmithKline Diagnostics, Sunnyvale, Calif.) test is the most reliable and widely used. However, testing is complicated by several technical issues that can affect clinical results, and even successful screening programs will miss a high proportion of tumors. Public compliance is often poor, and a number of indirect and "hidden" costs make surveillance programs much more expensive than is usually claimed. Almost all published screening trials are uncontrolled. They generally detect about 3-20 colorectal malignancies for every 10,000 people enrolled, but only about 5%-10% of occult blood reactions are due to cancer. Though screen-detected tumors tend to be at a relatively early stage, this does not imply any benefit of surveillance because of lead time and length biases inherent in the screening process. Only controlled trials can answer the central question of whether screening decreases mortality from bowel cancer. Two such trials are underway, but mortality data are not yet available from either.

Colonic Neoplasms↗

PubMed1999

Acoustic and ultrasonic tissue characterization--assessment of osteoporosis.

Osteoporosis, often termed the 'silent epidemic', has been defined as 'a decrease in bone mass and architectural deterioration of bone tissue, leading to enhanced bone fragility and consequent increase in fracture risk'. In the United Kingdom alone, the annual health costs are in excess of 750 million Pounds, with 60,000 patients suffering a hip fracture each year. A quarter of these will die within 12 months of their fracture, half of the remainder will never regain independent living. The established procedure for assessing the risk of osteoporotic fracture is via bone mineral density (BMD) assessment using dual-energy X-ray absorptiometry (DXA). However, DXA is an expensive technique and is not widely available. Within the past 15 years, ultrasound assessment of bone has rapidly advanced in scientific understanding, technical development and clinical utility. Measurements of cancellous bone (particularly at the calcaneus) are generally performed in preference to those of cortical bone (tibial cortex). There are currently 15 commercial systems available and over 3500 systems are in use world-wide. The low cost and portability offered by ultrasound systems should enable an integrated community-based screening programme to be established in the near future. Ultrasound measurements of bone are generally obtained using transmission rather than pulse-echo techniques owing to its highly attenuating nature. Ultrasound velocity and attenuation measurements are utilized. For velocity, there are well-defined fundamental relationships describing the dependence upon the elasticity and density of bone.

Absorptiometry, Photon↗