Notes from the Association of Teachers of Preventive Medicine: vaccine risk/benefit communication project.
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Child↗
Biomedical subjects
P Eason
Publications and source records attributed to P Eason.
Effectiveness and cost-effectiveness of linking the special supplemental program for women, infants, and children (WIC) and immunization activities.
OBJECTIVE: To raise immunization coverage among children at risk for underimmunization, we evaluated the effectiveness and cost-effectiveness of immunization activities in the Special Supplemental Program for Women, Infants and Children (WIC). METHOD: A controlled intervention trial was conducted in seven WIC sites in Chicago between October 1990 and March 1994. At intervention sites, staff screened children for vaccination status at every visit, referred vaccine-eligible children to either an on-site WIC nurse, on-site clinic, or off-site community provider, and issued either a 3-month supply of food vouchers to up-to-date children or a 1-month supply to children not up-to-date--a usual practice for high-risk WIC children. Our primary measure of effectiveness was the change in the baseline percentage of up-to-date children at the second birthday; cost-effectiveness was approximated for each of the three referral interventions. RESULTS: After one year, up-to-date vaccination coverage increased 23% above baseline for intervention groups and decreased 9% in the control group. After the second year, up-to-date vaccination further increased to 38% above baseline in intervention groups and did not change in the control group. The total cost per additional up-to-date child ranged from $30 for sites referring children off-site to $73 for sites referring children on-site to a nurse. CONCLUSION: This controlled intervention trial of screening, referral, and a voucher incentive in the WIC program demonstrated a substantial increase in immunization coverage at a low cost. Continuing to design linkages between WIC and immunization programs by building on WIC's access to at-risk populations is worth the investment.
Chicago↗
Unusual ocular condition in Burmese cats.
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Animals↗
Rapid on-slide location and analysis of enriched fetal nucleated cells from maternal blood.
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Cell Separation↗
A collaborative trial of a semi-automatic system for slide preparation and screening in cervical cytopathology.
We report a test of an experimental system for machine-aided screening in cervical cytology, comprising the 'CYTOPRESS' semi-automatic slide preparation system (Nijmegen) and the 'CERVIFIP' interactive scanner (Edinburgh). Material from women attending clinics in Edinburgh and Nijmegen was stratified according to the severity of the conventional laboratory diagnosis and selected randomly within strata for inclusion in the test. Monolayered slides were prepared by CYTOPRESS from cervical scrape material remaining after preparation of conventional smears and scanned by CERVIFIP to determine the positions of the most 'suspicious' objects. The test was based on a set of 701 monolayers, divided equally between 'negatives' and 'abnormals' of various grades, of which 585 (83.4%) were passed automatically as adequate for machine-aided analysis. Approximately 15% of adequate slides were passed as 'negative' without operator interaction. In the remaining 85%, the suspicious objects were inspected by a human operator and a decision was then made either to refer each monolayer for conventional microscopic analysis, or to pass it as 'negative'. Where discrepancies occurred between the conventional laboratory and the system results, a consensus diagnosis was reached by taking into account all relevant information including clinical data. Of those with a consensus diagnosis of CIN 3 or worse an estimated 9.3 +/- 4.1% were passed by the system as 'negative'. Closer investigation of these false-negatives revealed that most, and perhaps all, were preventable by system improvements either planned or in progress. Corresponding false-negative rates for those graded 'CIN 1 or 2' and 'negative-early recall' were estimated, respectively as 18.9 +/- 5.3% and 22.9 +/- 3.1%. Of those with a 'negative-routine recall' consensus, 19.4 +/- 2.5% were referred for conventional microscopic analysis, a level well within acceptable limits for cost-effectiveness. Women whose initial laboratory smears were negative, but whose consensus diagnosis was 'negative-early recall' or CIN, are being investigated further to determine whether cervical abnormalities were in fact present. Over two-thirds of this group were referred by the machine-aided system for conventional microscopic analysis.
Diagnosis, Computer-Assisted↗
Semi-automated cervical smear pre-screening systems: an evaluation of the Cytoscan-110.
This paper reports a test of a system for provision of machine assistance in cervical cytology screening. The hypothesis tested was that if the results of examination by a screener of a small number of high-ploidy cells on specially prepared monolayers, automatically selected and presented by the system, were combined with machine measurement of cell and cell population characteristics, it would be possible to distinguish conditions requiring further action on the part of a cytology service from those in which the patient could safely be signed out. The system appeared broadly capable of this discrimination, with a false-negative error not significantly different (for the numbers tested) on CIN1 and more severe cases to that obtaining for routine screening of the parallel PAP smears, and also to results obtained by a panel of three observers. The machine system appeared to do better than other systems in selecting borderline cases for review, but this may have been an artefact of the method of evaluation used: all results were compared with a 'reference diagnosis', which was computed using statistical techniques to integrate diagnostic information from all available sources. The false-negative error-rate of the system amounted to 5% of high-grade cases, 17% of CIN1's and 29% of borderlines, but were not substantially different from the FN rates for other reporting systems on the same material. The proportion of negative cases referred back for full cytological diagnosis was 34%. Despite this high false-positive rate, the system is potentially cost-effective in use.
Automation↗
Cell/substratum adhesions in RSV-transformed rat fibroblasts.
Cell/substratum adhesions have been studied in rat fibroblasts transformed by a ts-mutant of Rous sarcoma virus (LA-29) using light and electron microscopy and a variety of preparative methods including immunolabeling. Cells were studied both during the process of transformation, i.e., shifting from 39 degrees to 35 degrees C, and in a fully transformed state (passaged at 35 degrees C continuously). The typical focal contacts observed at 39 degrees C (restrictive temperature) were replaced by "point-contacts" (100-200 per cell) which were classified by immunolabeling as podosome-like adhesions containing actin, beta 1 integrin subunit, vinculin, talin, alpha-actinin, and small membrane patches containing clathrin and integrin. Tyrosine-phosphorylated proteins and pp60src were found in association with groups of small particles on the protoplasmic surface of ventral membranes by gold immunolabeling. Both types of point-contacts were visualized by electron microscopy of ultrathin sections and shadowed replicas and characterized by gold immunolabeling wherever possible. The overall composition of podosome-like adhesions is similar to focal contacts but there are differences in the three-dimensional organization of the microfilaments and in the topography of vinculin which is associated more with actin filaments than with the plasma membrane. The presence of talin and extracellular matrix receptor in podosomes together with the adhesive properties of these actin-containing structures argues against the hypothesis that pp60src affects the interaction of actin with the plasma membrane by phosphorylating the fibronectin receptor and/or other associated proteins.
Actin Cytoskeleton↗
Inheritance of plasma insulin-like growth factor-I and growth rate, food intake, food efficiency and abdominal fatness in chickens.
1. The inheritance of, and genetic and phenotypic correlations between, plasma insulin-like growth factor-I (IGF-I) and 28-(28dW) and 56-d (56dW) body weight, 28- to 56-d body weight gain (BWG), food intake (FI), food conversion ratio (FCR) and abdominal fatness (AF) at 56 d were determined by sib analyses in a population of 327 pedigreed progeny produced by matings between 18 cockerels and 72 pullets from a broiler strain of chickens bred at random for 8 generations. 2. Plasma IGF-I was measured in fed (IGF-If) and fasted (IGF-I) birds at 42 d. 3. Heritability estimates (sire + dam) were: 28dW 0.35 +/- 0.11, 56dW 0.49 +/- 0.13, BWG 0.51 +/- 0.13, FI 0.55 +/- 0.13, FCR 0.73 +/- 0.14, AF 0.49 +/- 0.13, IGF-If 0.10 +/- 0.08, IGF-Is 0.08 +/- 0.08. 4. The low heritability estimates with their high standard errors for the IGF-I measures precluded the calculation of meaningful genetic correlations between these and the performance traits. There were moderate to strong positive genetic correlations between 28dW, 56dW, FI and AF.
Abdomen↗
Analysis of rare high-DNA cell populations in serous effusions using continuous-motion imaging.
The rare high-DNA cell sub-populations in a series of serous effusion specimens were analysed to determine whether such measurements could provide a basis for the improved diagnosis of malignancy. Monolayer specimens stained with gallocyanin chrome-alum were scanned with the CERVIFIP continuous-motion image analyser to locate and measure the highest-DNA cells in the sample. Two types of features were obtained for the detected sub-populations; firstly, 'percentile ploidy' values which characterise the ploidy levels above which specified proportions of the total cells are found; and secondly 'percentage abnormal' values which characterise the proportion of the cells diagnosed as malignant during examination by a cytopathologist. The classification accuracy for one or both of these features was then obtained by comparison with the clinical outcome of each patient. The results gave a classification error of 9/44 (20%) using the 0.01% percentile ploidy alone, 6/44 (14%) using the 75% percentage abnormal feature alone, but only 2/44 (5%) from a box discriminant using both features. It was therefore concluded that the analysis of the high-DNA cell population could be of value in the diagnosis of malignancy in serous effusion specimens.
Adenocarcinoma↗
pp60v-src association with the cytoskeleton induces actin reorganization without affecting polymerization status.
The mechanism by which Rous sarcoma virus (RSV) induces a reorganization of actin and its associated proteins and a reduction in microfilament bundles is at present poorly understood. To examine the relationship between the organization of the microfilament system and the polymerization state of actin after transformation, we have investigated these changes in a Rat-1 cell line transformed by LA29, a temperature-sensitive (ts) mutant of RSV. Parallel immunofluorescence and biochemical analysis demonstrated that LA29 pp60v-src was ts for tyrosine kinase activity and cytoskeletal association. Changes in the distribution and organization of actin, alpha-actinin and vinculin were dependent on the association of a kinase-active pp60v-src molecule with the detergent-insoluble cytoskeleton. Whilst there was a transformation-dependent loss of microfilament bundles, biochemical quantitation demonstrated that the polymerization state of the actin in both detergent-soluble and insoluble fractions of these cells grown at temperatures either permissive or restrictive for transformation was quantitatively unchanged. These results indicate that the loss of microfilament bundles after transformation is not due to a net depolymerization of filamentous actin but rather to a reorganization of polymeric actin from microfilament bundles and stress fibers to other polymeric forms within the cell. The polymeric nature of the actin in these cells was confirmed by electron microscopy of cytoskeletons and substrate-adherent membranes.
Actin Cytoskeleton↗
Cryotechniques in macromolecular research (a comparative study).
There is no single method which would provide an unambiguous image of all types of biological macromolecules. The choice of method depends largely on the size and properties of the macromolecule. Obviously small molecules are best visualized by negative staining, the problems appear with negative staining of larger structures. Here, the uncertainty about which part of the complex is actually stained (top or bottom) makes correct interpretation difficult. Shadowing techniques have the advantage of both visualizing the surface and also delineating the whole macromolecule, but suffer from lower resolution due to the graininess of the metal. However, they are superior to negative staining for the visualization of thin linear macromolecules. The next series of problems includes the interaction of macromolecules with supporting films, glass coverslips or mica, which can be hydrophobic, hydrophilic or charged and these properties can influence the orientation of the molecules. Surface tension forces during air-drying must also be considered. We have used a variety of preparative techniques in our studies of biological macromolecules: (a) negative staining; (b) air-drying from ethanol; (c) glycerol-spraying; (d) adsorption freeze-drying; (e) monolayer freeze-etching. These methods have been tested on small viruses, water soluble proteins (ribosomes, F-actin, microtubules) and transmembrane proteins requiring the presence of detergents (sarcoplasmic reticulum ATPase, fibronectin receptor). We find that freeze-drying is the most reliable and easy method for molecules that withstand distilled water; freeze-etching can be successfully applied to transmembrane proteins (even in the presence of detergents or salt); the glycerol-spray technique provides an excellent alternative to the cryotechniques in particular for studies of single linear molecules.
Adenoviridae↗
Electron microscopy and structural model of human fibronectin receptor.
Highly-purified human fibronectin receptor (a heterodimer of two distinct subunits, alpha and beta) was studied using electron microscopy and a variety of preparative procedures. It was found that the receptor consists of a globular head approximately 80 by 120 A and two tails about 20 A thick and 180-200 A long. The whole complex is approximately 280 A long. At low concentrations of detergent the receptor forms doublets, triplets or rosettes associated with the tails which possess the transmembrane portion of the molecule. Computer-assisted structure prediction using the published amino acid sequence of both subunits showed differences in the secondary structure of the tails, the alpha-tail being rich in beta-strands, the beta-tail having five cysteine-rich repeats analogous to the EGF-like repeats of laminin. Estimates of the length of the tails from the predicted structure conformed well with the dimensions obtained from electron micrographs.
Amino Acid Sequence↗
Fetal blood chromosome analysis: some new indications for prenatal karyotyping.
Prenatal karyotyping using stimulated fetal blood lymphocytes was undertaken in 170 pregnancies between 16 and 36 weeks gestation for the following reasons--mosaicism or marker chromosomes found in amniotic fluid culture; a family history of X-linked mental retardation with fragile Xq28; fetal abnormalities detected ultrasonographically; late booking or amniotic fluid culture failure in patients with advanced age or balanced translocations; and twin pregnancies discordant for a chromosomal anomaly. Forty-one karyotypic abnormalities were detected (24%). These were: 45,X (7 cases), trisomy 13 (5 cases), trisomy 18 (6 cases), trisomy 21 (4 cases), twin pregnancy where one twin had trisomy 21 (1 case), supernumerary marker chromosome (3 cases, one of which occurred in a twin pregnancy), triploidy (3 cases), X-linked mental retardation with fragile site at Xq28 in males (6 cases), fetal erythroleukaemia (3 cases including 2 cases with Turner's), Fanconi's anaemia (1 case), unbalanced chromosome translocation 47,XY+der22,t(11;22) mat (1 case), mos 46,XX18p-/46,XX,-18+i(18q) (1 case), 46,XXdel(2q) (1 case), and 46,XYt(5;17) de novo (1 case). In fetuses at high risk of a chromosome aberration, a rapidly obtained karyotype is helpful and fetoscopy and fetal blood sampling are justified in the second or third trimester.
Amniotic Fluid↗
Visualization of cAMP receptor protein-induced DNA kinking by electron microscopy.
The effect of specific DNA binding of the cAMP . cAMP receptor protein complex to two DNA fragments (301 and 2685 base-pairs in length) containing the lac operon has been investigated by electron microscopy. It is shown that specific DNA binding of the cAMP . cAMP receptor protein complex induces a kink of 30 to 45 degrees in the DNA with the apex of the kink located at the site of protein attachment. These findings lend direct visual support for the kinking hypothesis based on the observation of anomalous electrophoretic mobility of DNA fragments containing specifically bound cAMP receptor protein.
Binding Sites↗
The use of cationic polyelectrolytes in the preparation of cell monolayers for automated cell scanning and diagnostic cytopathology.
The introduction of cationic polyelectrolytes as cellular adherents has significantly advanced the preparation of cervical scrape specimens for automated cell scanning and has also provided an efficient technique for the preparation of cell monolayers of other cytologic specimens, e.g., breast cyst fluids, urines and serous effusions, for diagnostic cytopathology. Variable thickness of cell preparation and cell overlap have both been resolved by laying cells onto glass slides coated with the cationic polyelectrolyte poly-L-lysine. We have determined the optimal conditions for pH, molecular weight, concentration and temperature for the application of poly-L-lysine as a cell-to-slide adhesive.
Cell Adhesion↗
The origin of the rapidly adhering cells found in amniotic fluids from foetuses with neural tube defects.
The number and morphologies of cells rapidly adhering to glass (RA cells) found in amniotic fluids from foetuses with neural tube defects is independent of soluble factors in the supernatant fluid. Cells taken directly from brain and spinal cord of normal foetuses, which are rapidly adherent in culture, show numerous similarities to those RA cells which are present in the amniotic fluids of foetuses with neural tube defects. This suggests that RA cells in amniotic fluid may be reliably used as a diagnostic marker of foetal lesions involving neural tissue, in particular spina bifida and anencephaly. Other RA cells extracted from foetal peritoneal cavity and bone marrow also have distinctive morphologies and may be useful in early antenatal diagnosis of congenital defects such as exomphalos.
Amniotic Fluid↗
Use of severity-adjusted length of stay to modify physician practice patterns.
OBJECTIVE: To compare inpatient length of stay among physicians by testing a new method for severity adjusting length of stay. DESIGN: A retrospective validation study with prospective follow-up after an intervention. SETTING: A 531-bed community teaching hospital. PATIENTS: Three hundred randomly selected patients from the 30,861 patients discharged in 1990. INTERVENTION: A physician with a significantly prolonged severity-adjusted length of stay was counseled and then monitored for three months. RESULTS: The correlation between the number of comorbidities, complications, and manifestations of disease processes (CCMDPs) was R2 = 0.658, t = 23.96 (p = .001). One physician had an unusually high severity-adjusted length of stay, but lowered it after he was counseled and monitored for three months. CONCLUSIONS: The number of CCMDPs recorded on the hospital discharge abstract can be used as a severity index to adjust a patient's length of stay for illness severity. Using linear regression analysis, a picture of the severity-adjusted length of stay can be derived for physicians. Through counseling and monitoring, individual physicians' lengths of stay patterns may be reduced.
Comorbidity↗