Partial thromboplastin time as a screening test.
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We have developed a Silica Clotting Time (SCT) test suitable to screen patients with lupus anticoagulants (LA) and compatible with photo-optical instruments. The SCT results were considered to be positive for LA whenever the clotting times were longer than the upper normal limit at low phospholipid concentration and to be confirmed when the prolonged clotting times were corrected to normal by high phospholipid concentration. We studied plasmas from healthy subjects, patients with known diagnoses of LA, patients with acquired deficiencies of blood coagulation and hemophiliacs with anti-factor VIII antibodies. The test was positive for all LA patients, and negative for all non-LA patients except 7 hemophiliacs with anti-factor VIII antibodies. Our data indicate that the SCT is a sensitive test, suitable for screening patients suspected of having LA. Its compatibility with photo-optical instruments makes it a suitable candidate to replace the kaolin clotting time. The contemporaneous performance of SCT at low and high phospholipid concentrations provides screening and confirmation in a single procedure.
A simple screening method for determining the fibrinolytic activity of plasma is described. A streptokinase activated system is used, which measures the result of the interplay of all components of the fibrinolytic system with the exception of activators, which are added in excess. Mean lysis time and standard deviation with this method is 6.9 +/- 1.4 min. The sensitivity of the method in detecting minor delays in clot lysis time is demonstrated.
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PURPOSE: To determine the appropriate patients, methods, and timing for screening for diabetic retinopathy. DATA SOURCES: Relevant articles were identified through prominent review articles, the authors' files, recommendations from experts, and a MEDLINE search (1986 to the present); additional references were selected from the bibliographies of identified articles. STUDY SELECTION: Selection of articles on the natural history of retinopathy was limited to large clinical series and formal epidemiologic studies of defined populations. Selection of articles on the therapeutic effect of photocoagulation and of glycemic control was limited to randomized trials. Sources bearing on the accuracy of screening modalities were necessarily more varied. DATA EXTRACTION: For important variables, individual estimates from multiple studies are presented rather than a single meta-analytic summary estimate. RESULTS: Screening for retinopathy is justifiable if early detection leads to less vision loss at an acceptable cost. The evidence shows that 1) laser therapy reduces the rate of vision loss by 50% among patients with proliferative retinopathy and macular edema, conditions that are often asymptomatic; 2) duration of diabetes is the main risk factor for retinopathy; and 3) standard ophthalmoscopic examination has only moderate sensitivity (about 80% in research settings) and specificity (greater than 90% for proliferative retinopathy but lower for macular edema), making seven-field stereophotography a more accurate method. Estimates of cost effectiveness indicate that screening for retinopathy not only saves years of vision but may be cost saving from a societal perspective. CONCLUSIONS: Screening for retinopathy in patients with diabetes, and subsequent photocoagulation therapy for those who have high risk macular edema or proliferative retinopathy, is clearly beneficial.
BACKGROUND: Neurofibromatosis-type 1 (NF1) is a genetic disorder characterized by developing optic pathway gliomas (OPGs) in 15%-20% of patients with higher estimates where consanguinity is prevalent. Clinically, NF1-OPG might be unpredictable with the risk of OPG progression and visual impairment. The optimal time for screening is controversial. We aim to identify the mean/median age at diagnosis of NF1-OPG and its clinical spectrum. METHODS: A systematic review of PubMed, Web of Science, and Embase databases was conducted for English-language publications from January 1993 to October 2025, exploring the visual screening of OPGs in NF1 patients, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and registered in the Prospective Register of Systematic Reviews (PROSPERO ID: CRD420251036244). Inclusion criteria focused on studies reporting the age at OPG diagnosis and visual manifestations in NF1 patients. Data were extracted on demographics, age at NF1 and OPG diagnosis, tumour location (using the Dodge classification), and presenting symptoms. Sixteen studies met the inclusion criteria. RESULTS: Among 4 739 NF1 patients, 818 had OPGs, with prevalence ranging from 4.2% to 46.7%. The age at NF1 diagnosis ranged from 0 to 132 months (mean: 18-38 months), and at OPG diagnosis from 0-240 months (median: 29-58 months). Approximately 58.4% of OPGs were asymptomatic, and 25% were above the age of 5 years. Among symptomatic patients, the most frequent presentations included decreased visual acuity (62%), abnormal optic disc (45%), proptosis (20%), strabismus (12%), and visual field defects (7%). CONCLUSIONS: NF1-related OPGs typically present early within 6 years of age. Early ophthalmologic and/or radiologic screening at the time of NF1 diagnosis enhances the detection of silent OPGs.
Since April, 1989 in Aomori Prefecture, mass-screening for ovarian cancer by means of transvaginal ultrasonography has been performed in a mass-screening car at the same time mass-screening for uterine cervical cancer. Subjects for this screening were self referred asymptomatic women 30 years of age or older. Real time ultrasonography was performed with a 5-MHz endovaginal transducer 5 sections for scanning were established by means of a transvaginal probe and all ultrasonic pictures obtained were recorded with an 8mm VTR. For women with abnormal ultrasonic findings, such as an ovary (tumor) over 30mm in size and massive ascites, a second screening or accurate examination was performed by retransvaginal ultrasonography, CT-scan, MRI and a combination assay of tumor markers. The results were as follows: The time required for the first screening, including bimanual examination, collection of Pap smear and ultrasonic examination, was about 60-70 seconds. The total number of screened women was 15,282, and 838 (5.5%) of them needed to receive the follow-up examinations. Laparotomy has been done for 48 women to date and 2 women were found to have premalignant and malignant ovarian tumors.
The systolic time intervals (LVET, PEP, and ratio LVET/PEP) were determined in 53 patients presenting with signs or symptoms of thyroid dysfunction. Patients with clinical evidence of congestive heart failure, with arterial hypertension or old myocardial infarction, and patients receiving cardioactive drugs, were excluded from the study. Thyroid function was evaluated by means of T3-RIA, serum thyroxin and TRH stimulation test.
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Largely unexplained increases in breast cancer incidence of about 1% per year have been documented back to the 1940s. Since 1982, breast cancer incidence in women aged 40 years and above has been increasing at a faster rate than this long-term secular trend, especially in women aged 60 years and above. Increases in the use of mammography since 1982 (which have been documented in population surveys of women) provide the most plausible explanation for the incidence increase over the long-term secular trend. A study by White et al. (J Natl Cancer Inst 1990;82:1546-52) found that, for women aged 45-64 years, the increase in mammography utilization could explain the incidence increase, while for women aged 65-74 years, it could account for only half the increase. The authors have developed an alternative model to that of White et al. that incorporates estimates of differential lead time (time from screen detection to clinical detection in the absence of screening) by age group. Using this model, the authors show that if older women have longer lead times, than similar increases in mammography utilization across age groups will lead to a larger incidence increase in older women. Thus, the observed increases in mammography utilization are generally concordant with increases in incidence, even in the older age groups.
Recent progress in gas dynamic virtual nozzle (GDVN) technologies in combination with high-brilliance synchrotron and X-ray free-electron lasers (XFELs) has allowed the visualization of protein dynamics in crystallo by mixing macromolecular protein crystals with a substrate using tunable mixing times on the order of milliseconds to seconds prior to serial X-ray diffraction data collection. This has become the method of choice for high-resolution structure determination of intermediate states. However, such experiments require large counts of crystals of proper sizes for high-resolution data collection, and premium beam times for screening efforts. Cryogenic microcrystal electron diffraction (MicroED) represents a complementary technique that may be a more accessible avenue for time-resolved nanocrystallography compared with serial X-ray diffraction experiments. MicroED can produce full diffraction datasets from just a few submicrometre-thick crystals, and the approach is more readily accessible, requiring standard cryogenic transmission electron microscopy (TEM) equipment available at many universities and institutes. Cryogenic MicroED, like other forms of cryo-EM, begins with rapidly freezing biological material on electron microscopy grids. In the case of MicroED, micro- to nano-crystals (<500 nm thick) are deposited onto electron microscopy grids and plunge-frozen for subsequent electron diffraction data collection. Here, we have incorporated GDVN technology developed originally for XFEL experiments into the freezing process as a first step towards time-resolved studies. We describe the limited deposition efficiency of the model MicroED protein proteinase K on TEM grids using GDVNs, preceding sample vitrification and successful MicroED data collection. We discuss both the initial results from such experiments and the methodological challenges in developing this approach into a reliable workflow for millisecond-to-second time-resolved structural studies of macromolecules. Our results promise a strategy to deposit crystals on grids using GDVNs and determine high-resolution structures by MicroED, constituting a first step towards development of time-resolved MicroED experiments.
A blood pressure measurement was part of a cardiovascular screening examination of 8397 middle-aged men taking part in the intervention section of the United Kingdom Heart Disease Prevention Project. Standardised training techniques reduced observer bias to acceptable limits in four out of a total of five observers. The time of day and room temperature both made significant differences to the blood pressure measurement. High room temperatures in particular apparently had a marked effect in reducing the level of blood pressure. There were consistent and large positive associations with increasing age and overweight. The survey revealed a poor degree of blood pressure control in the community at the time of screening--only 7% of the "hypertensive" population had their diastolic pressure controlled to below 100 mm Hg.
During screening procedures in Nordrhein-Westfalen in 1976 more than 100,000 persons had their, i.o. pressure measured for the first time. The results are now available from 66,957 subjects. From these 59,037 had a normal i.o. pressure, 6.941 had raised i.o. pressure, and in 979 subjects the i.o. pressure was very high. This was the first time that screening procedures on a large scale were carried out exclusively with the applanation tonometer. This procedure was carried out as part of a campaign to make the illness of glaucoma better known to the public.
BACKGROUND: We analyzed data from the Department of Veterans Affairs trial of steroid therapy for systemic sepsis to identify predictors of bacteremia and gram-negative bacteremia. METHODS: Of the 2568 patients screened for entry in the trial, 465 met the following criteria: presence of four of seven clinical signs of sepsis; blood cultures at the time of screening; and complete data on nine clinical parameters. The multivariate logistic regression model was used to identify predictors of bacteremia and gram-negative bacteremia. Predicted probabilities of having these types of infections were calculated using the identified predictors. Patients were then classified into groups with and without bacteremia (and gram-negative bacteremia) based on the predicted probability. Misclassification error rates were calculated for each method of categorization by comparing the true with the predicted grouping of patients. RESULTS: Three factors were independently predictive of bacteremia and gram-negative bacteremia: elevated temperature, low systolic blood pressure, and low platelet count. Using these three factors, classification methods were identified that predicted blood infection better than chance, but misclassification was also high. For predicting bacteremia, the maximum predicted positive rate was 83%, with a specificity of nearly 100% and a sensitivity of only 5%. For predicting gram-negative bacteremia, the maximum predicted positive accuracy was 100%, with a specificity also of 100% and a sensitivity of almost 0%. CONCLUSIONS: Using simple clinical parameters, we could not predict either bacteremia or gram-negative bacteremia with sufficient accuracy to be clinically meaningful; however, our approach represents a step in the direction of forecasting the bacterial organism responsible for sepsis in advance of culture results.
In a retrospective study of the cases of 415 patients with various malignant neoplasms, full-lung tomography and conventional chest roentgenography were compared for accuracy in the detection of pulmonary metastases. Sufficient information was available on 410 patients to permit confirmation as to whether pulmonary metastases were present at the time of screening chest roentgenographic and tomographic examinations. On screening by routine chest roentgenography, metastases were detected in 36 patients, 66.7% of the total with confirmed metastatic disease. Screening by full-lung tomography identified metastases in 51 (94.4%). Fifteen patients with normal chest roentgenograms had metastatic lesions on tomograms. Metastases were detected in 8.8% by chest roentgenograms and in 12.4% by tomograms in a population of cancer patients with a 13.2% incidence of pathologically confirmed metastatic lesions.
Mammography is the most important method for the diagnosis and the screening of breast diseases. Sensitivity and accuracy of mammography are very high in the detection of breast cancer. The use of the stereotaxic localization and fine-needle aspiration of nonpalpable breast lesions improve its effectiveness. The American Breast Cancer Detection Demonstration Project (BCDDP) has demonstrated the benefits of breast screening for women over 40 years of age. Many American medical associations and societies have adopted the guidelines based on the BCDDP results, promoting breast cancer screening for these women. However, recently released results of some randomized breast screening studies demonstrated only a 5% reduction in mortality from breast cancer in women 40-49 years of age, and a 40% reduction for women aged over 50 years. There is no explanation for this dilemma at the present time. However, screening mammography should stay available for women over 40 years of age.
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