Showing papers by "Johns Hopkins University published in 1994"
01 Jan 1994
TL;DR: In his new book, C4.5: Programs for Machine Learning, Quinlan has put together a definitive, much needed description of his complete system, including the latest developments, which will be a welcome addition to the library of many researchers and students.
Abstract: Algorithms for constructing decision trees are among the most well known and widely used of all machine learning methods. Among decision tree algorithms, J. Ross Quinlan's ID3 and its successor, C4.5, are probably the most popular in the machine learning community. These algorithms and variations on them have been the subject of numerous research papers since Quinlan introduced ID3. Until recently, most researchers looking for an introduction to decision trees turned to Quinlan's seminal 1986 Machine Learning journal article [Quinlan, 1986]. In his new book, C4.5: Programs for Machine Learning, Quinlan has put together a definitive, much needed description of his complete system, including the latest developments. As such, this book will be a welcome addition to the library of many researchers and students.
8,046 citations
Thomas Jefferson University1, Harvard University2, Scripps Health3, University of Pittsburgh4, University of British Columbia5, Memorial Hospital of South Bend6, Yale University7, Arizona Heart Institute8, University of Toronto9, St Lukes Episcopal Hospital10, Johns Hopkins University11, Lenox Hill Hospital12, University of Pennsylvania13, University of Texas at San Antonio14, Cleveland Clinic15
TL;DR: In selected patients, placement of an intracoronary stent, as compared with balloon angioplasty, results in an improved rate of procedural success, a lower rate of angiographically detected restenosis, a similar rate of clinical events after six months, and a less frequent need for revascularization of the original coronary lesion.
Abstract: Background Coronary-stent placement is a new technique in which a balloon-expandable, stainless-steel, slotted tube is implanted at the site of a coronary stenosis. The purpose of this study was to compare the effects of stent placement and standard balloon angioplasty on angiographically detected restenosis and clinical outcomes. Methods We randomly assigned 410 patients with symptomatic coronary disease to elective placement of a Palmaz-Schatz stent or to standard balloon angioplasty. Coronary angiography was performed at base line, immediately after the procedure, and six months later. Results The patients who underwent stenting had a higher rate of procedural success than those who underwent standard balloon angioplasty (96.1 percent vs. 89.6 percent, P = 0.011), a larger immediate increase in the diameter of the lumen (1.72 ±0.46 vs. 1.23 ±0.48 mm, P<0.001), and a larger luminal diameter immediately after the procedure (2.49 ±0.43 vs. 1.99 ±0.47 mm, P<0.001). At six months, the patients with stented ...
4,300 citations
TL;DR: Findings from a broad body of research on the factors that delay the decision to seek care are presented and examples of efforts to reduce maternal deaths are presented, with an emphasis on strategies to mobilize and adapt existing resources.
2,754 citations
TL;DR: A novel protease resembling ICE (prICE) that is active in a cell-free system that reproduces the morphological and biochemical events of apoptosis in the extracts including morphological changes, cleavage of PARP and production of an oligonucleosomal ladder.
Abstract: Recent studies suggest that proteases of the interleukin 1-beta-converting enzyme (ICE)/ced-3 family are involved in initiating the active phase of apoptosis. Here we identify a novel protease resembling ICE (prICE) that is active in a cell-free system that reproduces the morphological and biochemical events of apoptosis. prICE cleaves the nuclear enzyme poly(ADP-ribose) polymerase (PARP) at a tetrapeptide sequence identical to one of two ICE sites in pro-interleukin-1-beta. However, prICE does not cleave purified pro-interleukin-1-beta, and purified ICE does not cleave PARP, indicating that the two activities are distinct. Inhibition of prICE abolishes all manifestations of apoptosis in the extracts including morphological changes, cleavage of PARP and production of an oligonucleosomal ladder. These studies suggest that prICE might be pivotal in initiating the active phase of apoptosis in vitro and in intact cells.
2,631 citations
TL;DR: COX-2, but not COX-1, gene expression is markedly elevated in most human colorectal cancers compared with accompanying normal mucosa, and COx-2 expression seems to be increased in a subset of adenomas.
2,584 citations
TL;DR: New insights in understanding of the cell cycle reveal how fidelity is normally achieved by the coordinated activity of cyclin-dependent kinases, checkpoint controls, and repair pathways and how this fidelity can be abrogated by specific genetic changes.
Abstract: Multiple genetic changes occur during the evolution of normal cells into cancer cells. This evolution is facilitated in cancer cells by loss of fidelity in the processes that replicate, repair, and segregate the genome. Recent advances in our understanding of the cell cycle reveal how fidelity is normally achieved by the coordinated activity of cyclin-dependent kinases, checkpoint controls, and repair pathways and how this fidelity can be abrogated by specific genetic changes. These insights suggest molecular mechanisms for cellular transformation and may help to identify potential targets for improved cancer therapies.
2,514 citations
Journal Article•
TL;DR: The results support the idea that WAF1/CIP1 is a critical downstream effector in the p53-specific pathway of growth control in mammalian cells.
Abstract: The tumor growth suppressor WAF1/CIP1 was recently shown to be induced by p53 and to be a potent inhibitor of cyclin-dependent kinases In the present studies, we sought to determine the relationship between the expression of WAF1/CIP1 and endogenous regulation of p53 function WAF1/CIP1 protein was first localized to the nucleus of cells containing wild-type p53 and undergoing G 1 arrest WAF1/CIP1 was induced in wild-type p53-containing cells by exposure to DNA damaging agents, but not in mutant p53 -containing cells The induction of WAF1/CIP1 protein occurred in cells undergoing either p53 -associated G 1 arrest or apoptosis but not in cells induced to arrest in G 1 or to undergo apoptosis through p53 -independent mechanisms DNA damage led to increased levels of WAF1/CIP1 in cyclin E-containing complexes and to an associated decrease in cyclin-dependent kinase activity These results support the idea that WAF1/CIP1 is a critical downstream effector in the p53 -specific pathway of growth control in mammalian cells
2,056 citations
TL;DR: The DIGS is designed to be employed by interviewers who exercise significant clinical judgment and who summarize information in narrative form as well as in ratings, and should be useful as part of archival data gathering for genetic studies of major affective disorders, schizophrenia, and related conditions.
Abstract: This the Diagnostic Interview for Genetic Studies (DIGS), a clinical interview especially constructed for the assessment of major mood and psychotic disorders and their spectrum conditions The DIGS, which was developed and piloted as a collaborative effort of investigators from sites in the National Institute of Mental Health (NIMH) Genetics Initiative, has the following additional features: (1) polydiagnostic capacity; (2) a detailed assessment of the course of the illness, chronology of psychotic and mood syndromes, and comorbidity; (3) additional phenomenologic assessments of symptoms; and (4) algorithmic scoring capability The DIGS is designed to be employed by interviewers who exercise significant clinical judgment and who summarize information in narrative form as well as in ratings A two-phase test-retest (within-site, between-site) reliability study was carried out for DSM-III-R criteria—based major depression, bipolar disorder, schizophrenia, and schizoaffective disorder Reliabilities using algorithms were excellent (073 to 095), except for schizoaffective disorder, for which disagreement on estimates of duration of mood syndromes relative to psychosis reduced reliability A final best-estimate process using medical records and information from relatives as well as algorithmic diagnoses is expected to be more reliable in making these distinctions The DIGS should be useful as part of archival data gathering for genetic studies of major affective disorders, schizophrenia, and related conditions
2,024 citations
TL;DR: A search of a large database of expressed sequence tags derived from random complementary DNA clones revealed three additional human mismatch repair genes, all related to the bacterial mutL gene, demonstrating that this gene is responsible for HNPCC.
Abstract: Some cases of hereditary nonpolyposis colorectal cancer (HNPCC) are due to alterations in a mutS-related mismatch repair gene. A search of a large database of expressed sequence tags derived from random complementary DNA clones revealed three additional human mismatch repair genes, all related to the bacterial mutL gene. One of these genes (hMLH1) resides on chromosome 3p21, within 1 centimorgan of markers previously linked to cancer susceptibility in HNPCC kindreds. Mutations of hMLH1 that would disrupt the gene product were identified in such kindreds, demonstrating that this gene is responsible for the disease. These results suggest that defects in any of several mismatch repair genes can cause HNPCC.
1,903 citations
TL;DR: An aggressive smoking intervention program significantly reduces the age-related decline in FEV 1 in middle-aged smokers with mild airways obstruction and use of an inhaled anticholinergic bronchodilator results in a relatively small improvement inFEV 1 that appears to be reversed after the drug is discontinued.
Abstract: Objective. —To determine whether a program incorporating smoking intervention and use of an inhaled bronchodilator can slow the rate of decline in forced expiratory volume in 1 second (FEV1) in smokers aged 35 to 60 years who have mild obstructive pulmonary disease. Design. —Randomized clinical trial. Participants randomized with equal probability to one of the following groups: (1) smoking intervention plus bronchodilator, (2) smoking intervention plus placebo, or (3) no intervention. Setting. —Ten clinical centers in the United States and Canada. Participants. —A total of 5887 male and female smokers, aged 35 to 60 years, with spirometric signs of early chronic obstructive pulmonary disease. Interventions. —Smoking intervention: intensive 12-session smoking cessation program combining behavior modification and use of nicotine gum, with continuing 5-year maintenance program to minimize relapse. Bronchodilator: ipratropium bromide prescribed three times daily (two puffs per time) from a metered-dose inhaler. Main Outcome Measures. —Rate of change and cumulative change in FEV1over a 5-year period. Results. —Participants in the two smoking intervention groups showed significantly smaller declines in FEV1than did those in the control group. Most of this difference occurred during the first year following entry into the study and was attributable to smoking cessation, with those who achieved sustained smoking cessation experiencing the largest benefit. The small noncumulative benefit associated with use of the active bronchodilator vanished after the bronchodilator was discontinued at the end of the study. Conclusions. —An aggressive smoking intervention program significantly reduces the age-related decline in FEV1in middle-aged smokers with mild airways obstruction. Use of an inhaled anticholinergic bronchodilator results in a relatively small improvement in FEV1that appears to be reversed after the drug is discontinued. Use of the bronchodilator did not influence the long-term decline of FEV1. (JAMA. 1994;272:1497-1505)
1,751 citations
TL;DR: Serum PSA level, PSA density, and needle biopsy pathologic findings are accurate predictors of tumor extent and it may be reasonable to follow up some patients whose tumors are most likely insignificant with serial PSA measurements and repeated biopsies.
Abstract: Objectives. —We examined preoperative clinical and pathologic parameters in men with clinical stage T1c disease who underwent radical prostatectomy and correlated these findings with the pathologic extent of disease in the surgical specimen in an attempt to identify a subset of patients with potentially biologically insignificant tumor who might be followed up without immediate treatment. Design and Patients. —A case series of 157 consecutive men who underwent radical prostatectomy for clinical stage T1c disease compared with 64 similarly treated clinical stage T1a cancers (incidental minimal cancers found on transurethral resection of prostate) and 439 clinical stage T2 (palpable) cancers. Main Outcome Measures. —Pathologic stage, grade, and margins; tumor volume; and tumor location. Results. —Sixteen percent of tumors were insignificant ( 0.5 cm3or capsular penetration, with a Gleason score Conclusions. —Eighty-four percent of nonpalpable prostate cancers diagnosed by screening techniques are significant tumors and warrant definitive therapy. However, 16% are insignificant. Serum PSA level, PSA density, and needle biopsy pathologic findings are accurate predictors of tumor extent. It may be reasonable to follow up some patients whose tumors are most likely insignificant with serial PSA measurements and repeated biopsies. (JAMA. 1994;271:368-374)
TL;DR: The cellular and subcellular distributions of the glutamate transporter subtypes EAAC1, GLT-1, and GLAST in the rat CNS were demonstrated using anti-peptide antibodies that recognize the C-terminal domains of each transporter.
TL;DR: The identification of VHL mutations in a majority of localized and advanced sporadic renal carcinomas and in a second form of hereditary renal carcinoma indicates that the VHL gene plays a critical part in the origin of this malignancy.
Abstract: Multiple, bilateral renal carcinomas are a frequent occurrence in von Hippel-Lindau (VHL) disease. To elucidate the aetiological role of the VHL gene in human kidney tumorigenesis, localized and advanced tumours from 110 patients with sporadic renal carcinoma were analysed for VHL mutations and loss of heterozygosity (LOH). VHL mutations were identified in 57% of clear cell renal carcinomas analysed and LOH was observed in 98% of those samples. Moreover, VHL was mutated and lost in a renal tumour from a patient with familial renal carcinoma carrying the constitutional translocation, t(3;8)(p14;q24). The identification of VHL mutations in a majority of localized and advanced sporadic renal carcinomas and in a second form of hereditary renal carcinoma indicates that the VHL gene plays a critical part in the origin of this malignancy.
TL;DR: Two additional homologues of the prokaryotic mutL gene were found to be mutated in the germline of HNPCC patients, which doubles the number of genes implicated in H NPCC and may help explain the relatively high incidence of this disease.
Abstract: Hereditary nonpolyposis colorectal cancer (HNPCC) is one of man's commonest hereditary diseases. Several studies have implicated a defect in DNA mismatch repair in the pathogenesis of this disease. In particular, hMSH2 and hMLH1 homologues of the bacterial DNA mismatch repair genes mutS and mutL, respectively, were shown to be mutated in a subset of HNPCC cases. Here we report the nucleotide sequence, chromosome localization and mutational analysis of hPMS1 and hPMS2, two additional homologues of the prokaryotic mutL gene. Both hPMS1 and hPMS2 were found to be mutated in the germline of HNPCC patients. This doubles the number of genes implicated in HNPCC and may help explain the relatively high incidence of this disease.
TL;DR: The findings suggest that aberrant methylation of CpG islands may participate in the tumor-suppressor gene inactivations which initiate or cause progression of common human cancers.
Abstract: Mutational inactivation and allelic loss of the von Hippel-Lindau (VHL) gene appear to be causal events for the majority of spontaneous clear-cell renal carcinomas. We now show that hypermethylation of a normally unmethylated CpG island in the 5' region provides another potentially important mechanism for inactivation of the VHL gene in a significant portion of these cancers. This hypermethylation was found in 5 of 26 (19%) tumors examined. Four of these had lost one copy of VHL while one retained two heavily methylated alleles. Four of the tumors with VHL hypermethylation had no detectable mutations, whereas one had a missense mutation in addition to hypermethylation of the single retained allele. As would be predicted for the consequence of methylation in this 5' CpG island, none of the 5 tumors expressed the VHL gene. In contrast, normal kidney and all tumors examined with inactivating VHL gene mutations but no CpG island methylation had expression. In a renal cell culture line, treatment with 5-aza-2'-deoxycytidine resulted in reexpression of the VHL gene. These findings suggest that aberrant methylation of CpG islands may participate in the tumor-suppressor gene inactivations which initiate or cause progression of common human cancers.
Washington University in St. Louis1, Stanford University2, National Institutes of Health3, Pennsylvania State University4, Harvard University5, Vanderbilt University6, University of Tennessee Health Science Center7, University of Washington8, Case Western Reserve University9, George Washington University10, Johns Hopkins University11, Baylor College of Medicine12, Howard University13, University of California, Los Angeles14, University of Michigan15
TL;DR: It is concluded that ulcer patients with H. pylori infection require treatment with antimicrobial agents in addition to antisecretory drugs whether on first presentation with the illness or on recurrence.
Abstract: The National Institutes of Health Consensus Development Conference onHelicobacter pyloriin Peptic Ulcer Disease brought together specialists in gastroenterology, surgery, infectious diseases, epidemiology, and pathology, as well as the public to address the following questions: (1) What is the causal relationship ofH pylorito upper gastrointestinal disease? (2) How does one diagnose and eradicateH pyloriinfection? (3) Does eradication ofH pyloriinfection benefit the patient with peptic ulcer disease? (4) What is the relationship betweenH pyloriinfection and gastric malignancy? (5) WhichH pylori—infected patients should be treated? (6) What are the most important questions that must be addressed by future research inH pyloriinfections? Following 1½ days of presentations by experts and discussion by the audience, a consensus panel weighed the evidence and prepared their consensus statement. Among their findings, the consensus panel concluded that (1) ulcer patients withH pyloriinfection require treatment with antimicrobial agents in addition to antisecretory drugs whether on first presentation with the illness or on recurrence; (2) the value of treating of nonulcerative dyspepsia patients withH pyloriinfection remains to be determined; and (3) the interesting relationship betweenH pyloriinfection and gastric cancers requires further exploration. (JAMA. 1994;272:65-69)
TL;DR: In patients with cystic fibrosis, the administration of rhDNase reduced but did not eliminate exacerbations of respiratory symptoms, resulted in slight improvement in pulmonary function, and was well tolerated.
Abstract: Background Respiratory disease in patients with cystic fibrosis is characterized by airway obstruction caused by the accumulation of thick, purulent secretions, which results in recurrent, symptomatic exacerbations. The viscoelasticity of the secretions can be reduced in vitro by recombinant human deoxyribonuclease I (rhDNase), a bioengineered copy of the human enzyme. Methods We performed a randomized, double-blind, placebo-controlled study to determine the effects of once-daily and twice-daily administration of rhDNase on exacerbations of respiratory symptoms requiring parenteral antibiotics and on pulmonary function. A total of 968 adults and children with cystic fibrosis were treated for 24 weeks as outpatients. Results One or more exacerbations occurred in 27 percent of the patients given placebo, 22 percent of those treated with rhDNase once daily, and 19 percent of those treated with rhDNase twice daily. As compared with placebo, the administration of rhDNase once daily and twice daily reduced the ...
TL;DR: Applications of resonance energy transfer, including qualitative measurements as well as microscopy, average distance estimation, and distance distribution analysis, are surveyed.
TL;DR: MHC class I-restricted antigens are efficiently transferred in vivo to bone marrow-derived antigen-presenting cells, which suggests that human leukocyte antigen matching may be less critical in the application of tumor vaccines than previously thought.
Abstract: Many tumors express tumor-specific antigens capable of being presented to CD8+ T cells by major histocompatibility complex (MHC) class I molecules. Antigen presentation models predict that the tumor cell itself should present these antigens to T cells. However, when conditions for the priming of tumor-specific responses were examined in mice, no detectable presentation of MHC class I-restricted tumor antigens by the tumor itself was found. Rather, tumor antigens were exclusively presented by host bone marrow-derived cells. Thus, MHC class I-restricted antigens are efficiently transferred in vivo to bone marrow-derived antigen-presenting cells, which suggests that human leukocyte antigen matching may be less critical in the application of tumor vaccines than previously thought.
TL;DR: CpG island methylation appears in the oestrogen receptor (ER) gene in a subpopulation of cells which increases as a direct function of age in human colonic mucosa, and this same methylation change characterizes virtually all cells in all 45 colorectal tumours examined, including the earliest stages of tumour formation.
Abstract: We report that CpG island methylation, an epigenetic modification of DNA known to correlate closely with silencing of gene transcription, appears in the oestrogen receptor (ER) gene in a subpopulation of cells which increases as a direct function of age in human colonic mucosa. This same methylation change characterizes virtually all cells in all 45 colorectal tumours examined, including the earliest stages of tumour formation. ER gene expression is diminished or absent in colorectal tumours, and introduction of an exogenous ER gene in cultured colon carcinoma cells resulted in marked growth suppression. Our data suggest that methylation associated inactivation of the ER gene in ageing colorectal mucosa could be one of the earliest events that predispose to sporadic colorectal tumorigenesis.
TL;DR: It is concluded that the neurodegenerative processes associated with normal ageing and with Alzheimer's disease are qualitatively different and that Alzheimer's Disease is not accelerated by ageing but is a distinct pathological process.
TL;DR: Coexistent inactivations of both MTS1 and p53 was common and suggests that abnormal regulation of cyclin-dependent kinases may play an important role in the biology of pancreatic carcinoma.
Abstract: The MTS1 gene on chromosome 9p21 encodes the p16 inhibitor of cyclinD/Cdk-4 complexes, and is deleted or mutated in a variety of tumour types. We found allelic deletions of 9p21-p22 in 85% of pancreatic adenocarcinomas. Analysis of MTS1 in pancreatic carcinomas (27 xenografts and 10 cell lines) showed homozygous deletions in 15 (41%) and sequence changes in 14 (38%). These included eight point mutations (four nonsense, two missense and two splice site mutations) and six deletions/insertions, all accompanied by loss of the wild-type allele. Sequencing of MTS1 from primary tumours confirmed the mutations. Coexistent inactivations of both MTS1 and p53 was common and suggests that abnormal regulation of cyclin-dependent kinases may play an important role in the biology of pancreatic carcinoma.
Book•
08 Mar 1994TL;DR: In the United States, lung cancer remains the leading cause of cancer death in both men and women even though an extensive list of risk factors has been well-characterized as mentioned in this paper.
Abstract: In the United States, lung cancer remains the leading cause of cancer death in both men and women even though an extensive list of risk factors has been well-characterized. Far and away the most important cause of lung cancer is exposure to tobacco smoke through active or passive smoking. The reductions in smoking prevalence in men that occurred in the late 1960s through the 1980s will continue to drive the lung cancer mortality rates downward in men during the first portion of this century. This favorable trend will not persist unless further reductions in smoking prevalence are achieved.
TL;DR: It is concluded that goal-directed selection of a specific known featural identity may override stimulus-driven capture by salient featural singletons and top-down selectivity is indeed possible during visual search.
Abstract: Theeuwes (1992) found a distracting effect of irrelevant-dimension singletons in a task involving search for a known target. He argued from this that selectivity is determined solely by stimulus salience; the parallel stage of visual processing cannot provide top-down guidance to the attentive stage sufficient to permit completely selective use of task-relevant information. We argue that in the task used by Theeuwes, subjects may have adopted the strategy of searching for an odd form even though the specific target form was known. In Experiment 1, we replicated Theeuwes’s findings. Search for a circle target among diamond nontargets was disrupted by the presence of a diamond nontarget that was uniquely colored. In two subsequent experiments, we discouraged the singleton detection strategy, forcing subjects to search for the target feature. There was no distracting effect of a color singleton in these experiments, even with displays physically identical to those of Experiment 1, demonstrating that top-down selectivity is indeed possible during visual search. We conclude that goal-directed selection of a specific known featural identity may override stimulus-driven capture by salient featural singletons.
TL;DR: Analysis of sib-pair analysis of 170 individuals from 11 Amish families revealed evidence for linkage of five markers in chromosome 5q31.1 with a gene controlling total serum immunoglobulin E (IgE) concentration, and a combination of segregation and maximum likelihood analyses provided further evidence.
Abstract: Sib-pair analysis of 170 individuals from 11 Amish families revealed evidence for linkage of five markers in chromosome 5q31.1 with a gene controlling total serum immunoglobulin E (IgE) concentration. No linkage was found between these markers and specific IgE antibody concentrations. Analysis of total IgE within a subset of 128 IgE antibody-negative sib pairs confirmed evidence for linkage to 5q31.1, especially to the interleukin-4 gene (IL4). A combination of segregation and maximum likelihood analyses provided further evidence for this linkage. These analyses suggest that IL4 or a nearby gene in 5q31.1 regulates IgE production in a nonantigen-specific (noncognate) fashion.
TL;DR: This paper addresses questions about when primary care physicians act as "gatekeepers" to specialist services, what is the effect on outcomes, and how many general practitioners are needed in a primary-care-oriented system.
TL;DR: A noxious, unstable gas, nitric oxide, a byproduct of automobile exhaust, electric power stations, and lightning, was discovered in the body, where it participates in various functions, including suppression of pathogens, vasodilation, and neurotransmission, focusing on its clinical relevance.
Abstract: Purpose: To review the physiologic role of nitric oxide, an unusual messenger molecule that mediates blood vessel relaxation, neurotransmission, and pathogen suppression. Data Sources: A MEDLINE se...
TL;DR: Based on quantitative comparison, the chirp scaling algorithm provides image quality equal to or better than the precision range/Doppler processor, as defined by the system bandwidth.
Abstract: A space-variant interpolation is required to compensate for the migration of signal energy through range resolution cells when processing synthetic aperture radar (SAR) data, using either the classical range/Doppler (R/D) algorithm or related frequency domain techniques. In general, interpolation requires significant computation time, and leads to loss of image quality, especially in the complex image. The new chirp scaling algorithm avoids interpolation, yet performs range cell migration correction accurately. The algorithm requires only complex multiplies and Fourier transforms to implement, is inherently phase preserving, and is suitable for wide-swath, large-beamwidth, and large-squint applications. This paper describes the chirp scaling algorithm, summarizes simulation results, presents imagery processed with the algorithm, and reviews quantitative measures of its performance. Based on quantitative comparison, the chirp scaling algorithm provides image quality equal to or better than the precision range/Doppler processor. Over the range of parameters tested, image quality results approach the theoretical limit, as defined by the system bandwidth. >
TL;DR: The VF-14 is a reliable and valid measure of functional impairment caused by cataract and provides information not conveyed by visual acuity or a general measure of health status.
Abstract: Objective: To describe the development and the performance of a brief questionnaire designed to measure functional impairment caused by cataract (the VF-14). Design: Observational cross-sectional study. Patients were recruited between July 15 and December 15, 1991. Setting: Patients were recruited from the practices of 70 ophthalmologists, located in Columbus, Ohio (N=21), St Louis, Mo (N=26), and Houston, Tex (N=23). Patients: Seven hundred sixty-six patients undergoing cataract surgery for the first time. Main Outcome Measures: Preoperative best corrected visual acuity in each eye; scores on the VF-14, a new index of functional impairment in patients with cataract; patient reports of overall trouble and satisfaction with their vision; and scores on the Sickness Impact Profile, a measure of general health status. Results: The VF-14 has high internal consistency (Cronbach's α=.85) and correlates more strongly with the overall self-rating of the amount of trouble and satisfaction patients have with their vision than do several measures of visual acuity or the Sickness Impact Profile score. The VF-14 score is moderately correlated with visual acuity in the better eye. Conclusions: The VF-14 is a reliable and valid measure of functional impairment caused by cataract and provides information not conveyed by visual acuity or a general measure of health status.
TL;DR: In this article, surface and interface stresses in solids are defined and their role in the thermodynamics of solids is presented, along with a review of selected theoretical calculations and experimental measurements.