A national study of Chinese youths' attitudes towards students with intellectual disabilities.

BACKGROUND: In recent years, there has been a global effort to support the inclusion of students with intellectual disabilities (ID) in schools and classrooms. China in particular has recently enacted laws that provide for inclusive educational opportunities for students with ID. There are many barriers, however, to successfully including students with ID in regular education schools and classrooms, one of which is negative attitudes. Over the past decade, much research has focused on documenting the attitudes of the adult public; however, adults only represent one segment of society as it is youth who play a critical role in the successful inclusion and acceptance of students with ID in schools and classrooms. The aim of this study was to replicate a previous study of middle school-aged youths' attitudes towards the inclusion of peers with ID conducted with youth in the USA with similar aged youth in China. METHODS: A survey was conducted with a random sample of 4059 middle school-aged youth in China on their attitudes towards students with ID. Students' attitudes were measured in terms of their perceptions of the capabilities of students with ID, their beliefs about and expectations regarding the inclusion of students with ID and their willingness to interact with students with ID both in and out of school. RESULTS: The findings indicated that youth in China (1) perceive students with ID as moderately, rather than mildly, impaired; (2) believe that students with ID can not participate in their academic classes; (3) view inclusion as having both positive and negative effects on them personally; and (4) do not want to interact with a peer with ID in school, particularly on academic tasks. Structural equation modelling showed that youths' perceptions of the competence of students with ID significantly influenced their willingness to interact with these students and their support of inclusion. CONCLUSIONS: The findings replicated previous research conducted with middle school-aged youth in the USA and are discussed from a cultural perspective and in terms of the current special education policies and practices in China.

How do HMOs achieve savings? The effectiveness of one organization's strategies.

OBJECTIVE: To examine how a group practice used organizational strategies rather than provider-level incentives to achieve savings for health maintenance organization (HMO) compared to fee-for-service (FFS) patients. DATA SOURCES/STUDY SETTING: A large group practice with a group model HMO also treating FFS patients. Data sources were all patient encounter records, demographic files, and clinic records covering 3.5 years (1986-1989). The clinic's procedures to record services and charges were identical for FFS and HMO patients. All FFS and HMO patients under age 65 who received any outpatient services during approximately 100,000 episodes of the seven study illnesses were eligible. STUDY DESIGN: Using an explanatory case design, we first compared HMO and FFS rates of resource utilization, in standardized dollars, which measured the impact of organizational strategies to influence patient and provider behavior. We then examined the effect of HMO insurance and organizational measures to explain total outpatient use. Key variables were standardized charges for all outpatient services and the HMO's strategies. PRINCIPAL FINDINGS: Patient and provider behavior responded to organizational strategies designed to achieve savings for HMO patients; for instance, HMO patients used midlevel providers and generalists more often and ER and specialists less often. Overall HMO savings, adjusted for case mix, were explained by the specialty of the physicians the patients first visited and appeared to affect patients with average health more than others. CONCLUSION: Organizational strategies, without resort to differential financial incentives to each provider, resulted in lower rates of outpatient services for HMO patients. Savings from outpatient use, especially for common diseases that rarely require hospitalization, can be substantial.

Gingival crevicular blood for assessment of blood glucose in diabetic patients.

In this study 50 patients with diabetes mellitus had gingival crevicular blood from periodontal probing collected in small plastic pipettes. The pipettes transferred the crevicular blood to a non-wipe glucose self-monitoring instrument. At the same time, finger-stick capillary blood measurements were analyzed in the same glucose self-monitoring instrument, and venous blood was collected for measurement in a laboratory glucose analyzer. Each laboratory measurement was corrected from a serum glucose value to a whole blood glucose value by a function of the patient's hematocrit. This corrected glucose value allowed direct comparison of the laboratory measurement to the intraoral and finger-stick whole blood measurements. The patient blood glucose concentrations ranged from 59 mg/dl to 366 mg/dl. The gingival crevicular blood exhibited a correlation of r = 0.975 (P < .0001) to the corrected laboratory standard measurement, with a mean prediction error (bias) of -4.11 mg/dl and a root mean square error (precision) of 17.43 mg/dl. The finger-stick blood had a correlation of r = 0.983 (P < .0001) to the corrected laboratory standard, with a mean prediction error of 4.65 mg/dl and a root mean square error of 14.48 mg/dl. The American Diabetic Association recommends that the prediction error of blood glucose monitoring devices fall within 15% of the laboratory standard. Using this criterion 92% of the gingival crevicular measurements and 90% of the finger-puncture measurements fell within 15% of the laboratory value.(ABSTRACT TRUNCATED AT 250 WORDS)

Studies of aerosol distributions in a small laboratory containing a heated phantom.

In order to provide information to assist in the design and planning of workplace air-sampling facilities, we have studied the variations in time and space of aerosol concentrations in a small room containing a glove-box and a heated phantom. Aerosol concentrations are reduced by factors of 10(2)-10(3) between the source and the phantom and walls of the room. Time-series plots of concentration show large departures from mean concentrations and fluctuations measured at the mouth and chest of the phantom are frequently uncorrelated. Both the average concentration around the phantom and the fluctuations in concentration tend to increase when the phantom is heated.

Creation of realistic appearing simulated patient cases using the INTERNIST-1/QMR knowledge base and interrelationship properties of manifestations.

The Internist-1/Quick Medical Reference (QMR) knowledge base (KB) describes the clinical manifestations of some 600 diseases in the domain of internal medicine. This KB, while not representing deep causal modelling of disease processes, is nonetheless effective in providing medical diagnostic assistance through the QMR medical decision support system. One potential application of this extensive KB is the generation of simulated patient cases for use in educating health professionals. However, the "flat" KB is not adequate for this because the clinical manifestations used in the disease descriptions are not mutually independent. While it is theoretically possible to construct disease descriptions which embody pathophysiologic mechanisms of disease causality, it is not practical from the standpoint of resource utilization. Short of constructing a causal knowledge base, the authors herein describe the generation of realistic appearing simulated patient case data using existing information in the knowledge base. This existing information in the KB is in the form of properties which represent a shallow form of interrelationships of the manifestations. The authors conclude that this ability to generate simulated cases represents another view in which to look at an extensive knowledge base, as well as having application to constructing intelligent tutoring systems for health professionals in training.

A computer-assisted medical diagnostic consultation service. Implementation and prospective evaluation of a prototype.

STUDY OBJECTIVE: To evaluate the accuracy of a computer-aided consultation service using academic general internists and the Quick Medical Reference (QMR) diagnostic program: and to study the impact of the consultation on the diagnostic behavior of physicians caring for patients. DESIGN: Prospective study of the diagnostic accuracy of computer-aided consultation in 31 cases, as well as a prospective study of ward team diagnoses and opinions before and after consultation. SETTING: General medicine wards of two tertiary care centers. PARTICIPANTS: Thirty-one patients identified as posing a diagnostic challenge and meeting eligibility criteria, as well as the housestaff caring for these patients. MEASUREMENTS AND MAIN RESULTS: After 6 months follow-up, diagnoses were established in 20 of 31 cases. The diagnostic sensitivity of the computer-assisted diagnoses, 85% (95% CI, 56% to 97%), was similar to that of the consult service physicians, 80% (95% CI, 55% to 94%), but better than that of the ward teams, 60% (95% CI, 33% to 81%; P = 0.03 using the binomial test). The consultation influenced the postconsultation differential diagnoses of the ward teams in 26 of the 31 cases (95% CI, 92% to 95%). House officers rated the consultation service as being educationally helpful in 25 of the 31 cases (95% CI, 62% to 94%). CONCLUSIONS: Computer-aided diagnostic consultation, when provided by physicians familiar with the limitations of the system and capable of overriding inappropriate suggestions, was both accurate and educationally helpful in most cases. The system provided reasonable diagnostic suggestions not previously considered by the ward teams and these suggestions were valued sufficiently to cause alteration of the original differential diagnoses.

Mitomycin C-induced bidirectional transcription from the colicin E1 promoter region in plasmid ColE1.

Treatment of a colicinogenic culture with mitomycin C induces convergent transcription from two adjacent promoters at the beginning of the colicin E1 gene. S1-mapping and primer extension assays indicate that the mitomycin C-inducible transcripts correspond to colicin E1 mRNA (cea mRNA) and to a transcript, designated RNA-C, that may code for an entry exclusion function. Nucleotide sequences that strongly resemble a consensus sequence for LexA protein binding sites span the transcription start points for cea mRNA and RNA-C. These putative operator sequences overlap by one base pair and bind LexA protein (Ebina, Y., Takahara, Y., Kishi, F., Nakazawa, A. and Brent, R. (1983) J. Biol. Chem. 258, 13258-13261). The data suggest that mitomycin C-induced bidirectional transcription from the cea mRNA and RNA-C promoters is controlled by the SOS regulatory system of Escherichia coli.

Synthesis of in vitro Co1E1 transcripts with 5'-terminal ribonucleotides that exhibit noncomplementarity with the DNA template.

A region that forms the S1 nuclease site in Co1E1 DNA is shown to code for an in vitro transcript, called S1 RNA-B, which contains a 5'-terminal GTP residue that exhibits noncomplementarity with the template's DNA sequence. The synthesis of S1 RNA-B initiates four bases upstream from the start point for S1 RNA-C. The initial four bases in S1 RNA-B and S1 RNA-C are identical. The relative synthesis of S1 RNA-B to S1 RNA-C is sensitive to the concentration of GTP, a substrate that is required for elongation past the +4 position in S1 RNA-C. Dinucleotides that are expected to only initiate synthesis of S1 RNA-C yield two transcripts that appear to initiate from the S1 RNA-C and S1 RNA-B start sites. In vitro studies involving other Co1E1 transcripts, RNA-B and RNA-C, provide similar observations concerning the noncomplementary initiation phenomenon. A model involving transcriptional slippage is suggested to explain the noncomplementary initiation phenomenon. The model proposes that the cycling reaction of Escherichia coli RNA polymerase produces tetranucleotides that are transposed to nearby upstream sequences for priming transcription.

Isolation of duplicated human c-src genes located on chromosomes 1 and 20.

The oncogene (v-src) of Rous sarcoma virus apparently arose by transduction of the chicken gene known as c-src(chicken). We isolated DNA fragments representative of two src-related loci from recombinant DNA bacteriophage libraries of the human genome. One of these loci, c-src1(human), appeared to direct the synthesis of a 5-kilobase polyadenylated RNA that presumably encodes pp60c-src(human). Probes specific for the other locus, c-src2(human), did not hybridize to polyadenylated RNA prepared from a variety of human cell lines. Partial nucleotide sequence determinations of the loci demonstrated that c-src1(human) is highly related to chicken c-src and that c-src2(human) is slightly more divergent. The sequences imply that the final two coding exons of each human locus are identical in length to those of chicken c-src and that the location of an amber stop codon is unchanged in all three loci. c-src1(human) has been mapped to chromosome 20, and the second locus is located on chromosome 1. We conclude that c-src1(human) is the analog of c-src(chicken) and that the duplicated locus, c-src2(human), may also be expressed.

Expression of v-src and chicken c-src in rat cells demonstrates qualitative differences between pp60v-src and pp60c-src.

The retroviral oncogene v-src arose by transduction of the cellular gene c-src. The similarity between these genes raised the possibility that c-src might be able to elicit neoplastic growth. We explored this by constructing a chimeric plasmid that allows the expression of chicken c-src. A rat cell line containing ten times the normal intracellular level of pp60c -src was isolated after transfecting rat-2 cells with the chimeric DNA. These cells produce the protein encoded by c-src ( pp60c -src) in quantities at least three times greater than required to achieve transformation by the product of v-src ( pp60v -src). The cells remain phenotypically normal, contain actin cables, and do not grow in soft agar. However, transfection of the cell line containing elevated cells of pp60c -src or Rat-2 cells with a molecular clone of v-src produces cells that exhibit properties of biologically transformed cells: round morphology, disrupted actin cables, and ability to grow in soft agar.

The 5'-terminal ribonucleotide of an in vitro ColE1 transcript is not complementary to the DNA template.

A set of overlapping promoters in ColE1 DNA is identified using DNA and RNA sequencing methods. These promoters initiate a divergent pattern of in vitro transcription from a region near the colicin E1 promoter. A comparison of the 5'-terminal RNA sequences of the in vitro transcripts with the DNA sequence of the template indicates that one transcript initiates with a ribonucleotide (pppG) which is not complementary to the DNA template (a thymidylate residue is present on the coding strand at the designated transcription start point). A structural and functional counterpart for this phenomenon is suggested to exist near the opposite end of the colicin E1 gene.

Transduction of a cellular oncogene: the genesis of Rous sarcoma virus.

The oncogene of Rous sarcoma virus (v-src) arose by transduction of a cellular gene (c-src). In an effort to explore the mechanism of transduction, we have identified the splice acceptor site used in the genesis of mRNA for v-src, shown that an equivalent site is used in the splicing of mRNA for c-src, and determined the nucleotide sequence from the boundaries of homology between v-src and c-src. Our data indicate that (i) only a portion of c-src is represented within v-src, (ii) the leftward recombination between the genome of the transducing virus and c-src occurred in an intron of the cellular gene, (iii) v-src is in part a spliced version of the corresponding portion of c-src, and (iv) nucleotide sequences represented once in the genome of the transducing virus become duplicated to flank v-src. These findings indicate that the first step in transduction is probably recombination between DNA forms of the transducing viral genome and c-src and otherwise support the prevailing model for transduction by retroviruses. The carboxyl termini of the proteins encoded by v-src and c-src differ appreciably. An unidentified domain of 127 or 128 nucleotides is located at different positions in the genomes of two strains of RSV and gives evidence of being a foreign element that entered the viral genomes by genetic transposition independent of the transduction of src.

How physicians view the process of change in their practice behavior.

The changes all physicians make in their treatment of patients constitute a neglected but key issue in the operation of the health care system. Identification of a model of this crucial change process was the purpose of this study. Interviews with a random sample of 66 physicians representing five specialties produced data on 182 changes. The fundamental stages in the change process were priming (coming to feel dissatisfaction with some aspect of practice behavior), focusing (learning of alternative practice behavior), and follow-up (obtaining further information or advice regarding the possible change). Any of a variety of information sources may focus a change, but follow-up is overridingly dependent on colleague communication (representing local professional opinion) and journals (representing an authoritative professional perspective). This change process model provides a basis for orienting continuing medical education activities to the achievement of behavioral outcomes.

Representation of DNA sequences in recombinant DNA libraries prepared by restriction enzyme partial digestion.

We present a theoretical study of the fraction of sequences incorporated in a recombinant DNA partial digest library as a function of the size of the library. The fraction incorporated depends on the degree of restriction enzyme partial digestion. If all restriction sites in the target DNA can be cleaved with the same rate, optimum incorporation of sequences is observed when the number average length of the digested DNA equals the desired average length of the cloned insert. Overdigestion severely reduces the fraction of sequences present in a sample of clones. Heterogeneity in restriction enzyme cleavage rates also reduces the fraction incorporated, and underdigestion improves sequence representation in the face of cleavage rate heterogeneity. Practical methods for determining the number average length of partially digested DNAs are also presented.

The levels of plasma cholesterol in the human fetus throughout gestation.

The present study was undertaken to define the umbilical cord plasma concentrations of cholesterol throughout human gestation. Mixed arterial and venous cord plasma samples obtained from abortuses of women undergoing elective abortion or from infants of women who underwent spontaneous premature vaginal delivery, and from infants of women who delivered vaginally at term were assayed for cholesterol by a micro-enzymatic method. No cases that involved any maternal or fetal complications (other than prematurity) were included in this study. Early in gestation (10-16 weeks post-conception), the total cholesterol level in cord plasma was 85.4 +/- 30.7 mg/dl (mean +/- SD), N = 68, with the cholesterol levels in some samples falling within the range of those of adults. Between 16.5 and 20 weeks post-conception, the umbilical cord plasma cholesterol level declined to 39.9 +/- 21.0 mg/dl, n = 19 (P less than 0.001). The cholesterol concentration in umbilical cord plasma then rose to 67.8 +/- 24.0 mg/dl, n = 17 (P less than 0.01) between 26.5 and 32 weeks of gestation. Thereafter, a second decline in the umbilical cord plasma cholesterol level occurred, with the values at 32.5-36 weeks being 58.4 +/- 13.6 mg/dl (n = 16), and at 36.5 to 40 weeks post-conception (term) being 51.4 +/- 11.5 mg/dl, n = 44 (P less than 0.01 vs. 26.5-32 wks). We suggest that the observed changes in fetal cholesterol levels could be related to alterations during development in the rates of lipoprotein-cholesterol biosynthesis and subsequent clearance from plasma by the fetal adrenals wherein cholesterol is used as substrate for steroid biosynthesis.

Cellular homologue (c-src) of the transforming gene of Rous sarcoma virus: isolation, mapping, and transcriptional analysis of c-src and flanking regions.

The tumorigenic properties of Rous sarcoma virus are attributable to a 60,000-dalton protein, pp60v--src, encoded by a single viral gene, v-src. A homologous gene, c-src, that contains the information for a 60,000-dalton protein, pp60c--src, has been identified in all tested vertebrate cells. By screening a recombinant DNA library representative of the chicken genome, we isolated two overlapping DNA fragments that contain more than 30 kilobases (kb) of DNA spanning the coding sequences for pp60c--src. This 30-kb region is devoid of moderately or highly repeated sequences and shares homology with the entire viral gene and noncoding sequences 5' of v-src. Although v-src has an uninterrupted coding sequence, c-src is interrupted by a minimum of seven intervening sequences. At least two polyadenylylated RNAs seem to be encoded within the DNA we have isolated. The larger RNA, approximately 3.9 kb, is the presumptive c-src mRNA; the smaller transcript of about 2 kb hybridizes to DNA sequences several kb from the 3' end of the v-src/c-src homology area.