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PubMed1993

Molecular cloning and characterization of acrA and acrE genes of Escherichia coli.

The DNA fragment containing the acrA locus of the Escherichia coli chromosome has been cloned by using a complementation test. The nucleotide sequence indicates the presence of two open reading frames (ORFs). Sequence analysis suggests that the first ORF encodes a 397-residue lipoprotein with a 24-amino-acid signal peptide at its N terminus. One inactive allele of acrA from strain N43 was shown to contain an IS2 element inserted into this ORF. Therefore, this ORF was designated acrA. The second downstream ORF is predicted to encode a transmembrane protein of 1,049 amino acids and is named acrE. Genes acrA and acrE are probably located on the same operon, and both of their products are likely to affect drug susceptibilities observed in wild-type cells. The cellular localizations of these polypeptides have been analyzed by making acrA::TnphoA and acrE::TnphoA fusion proteins. Interestingly, AcrA and AcrE share 65 and 77% amino acid identity with two other E. coli polypeptides, EnvC and EnvD, respectively. Drug susceptibilities in one acrA mutant (N43) and one envCD mutant (PM61) have been determined and compared. Finally, the possible functions of these proteins are discussed.

Acriflavine↗
PubMed2005

ACR II: improved absolute cryogenic radiometer for low background infrared calibrations.

A second-generation absolute cryogenic radiometer (ACR II) was developed for use at the Low Background Infrared calibration facility at the National Institute of Standards and Technology. The need for spectral calibrations of very sensitive [D* = 10(14) cm (Hz)1/2W(-1)] infrared detectors necessitated the use of a cryogenic infrared monochromator and a more sensitive radiometer. The improved low-power performance of the ACR II compared with the older absolute cryogenic radiometer (ACR) has also made it useful as the primary standard for the calibration of cryogenic blackbody sources that are used as low-power infrared sources. The responsivity of the new radiometer's receiver is 210 K/mW with a type A (random component) standard uncertainty of at most 7 pW when making power measurements of less than 10 nW. The original ACR has a responsivity of 29 K/mW and has a type A standard uncertainty of approximately 100 pW when making a similar low-noise-power measurement. Other properties of the radiometers are also described and compared.

Journal Article↗
PubMed1995

Anti-neutrophil cytoplasm antibodies in patients with ACR criteria for polyarteritis nodosa: help for systemic vasculitis classification?

The american college of rheumatology (ACR) proposed in 1990 revised clinical criteria for systemic vasculitis classification to define homogeneous group of patients for clinical trials. However, microscopic polyarteritis (MPA) was not clearly identified from polyarteritis nodosa (PAN). Since anti-neutrophil cytoplasm antibodies (ANCA) are markers of disease activity of small vessel vasculitides including MPA, we tested the clinical significance of ANCA in 24 patients with PAN according to the ACR 1990 criteria. Two of 24 patients had ANCA, as defined by indirect immunofluorescence on normal human neutrophils, antigen-specific ELISA and Western blot analysis. However, they exhibited histologically proven small vessel but not medium vessel vasculitis. Furthermore, they had neither artery microaneurysms nor large organ injury consequent upon large vessel occlusion. Although they satisfied ACR criteria for PAN, they probably were misclassified and should be considered as MPA. We conclude that: (i) ANCA are not found in patients with classical PAN in the absence of MPA features; (ii) caution should be exercised when defining PAN according to the ACR 1990 criteria; (iii) ANCA may help systemic vasculitis classification.

Adult↗
PubMedDate not supplied

New tools from the ACR (American College of Radiology): appropriateness criteria and utilization analysis.

Performing a clinically unnecessary study can cost a practice money under managed care and capitation contracts. The American College of Radiology (ACR) has developed two tools to help radiology facilities practice cost-efficient medicine without sacrificing quality of care: appropriateness criteria and utilization analysis. Appropriateness criteria were established by the ACR Board of Chancellors in 1993 to help imaging facilities determine appropriate imaging studies; these were first published in 1995; a subsequent edition will be published in 1996 and annually thereafter. Development of the criteria was based on Agency for Health Care Policy and Research guidelines. A task force which clinical conditions and variants were to be studied. The task force then performed a literature search. Members then reviewed the literature and reached a conclusion about the appropriateness of the various procedures. Because capitated contracts require some knowledge of the utilization of services, the ACR formed the utilization analysis committee in 1994. Facilities submit utilization data on a quarterly basis to the ACR. The data is then combined into both regional and national databases. These databases report back to the participating facilities, which can then compare themselves with other groups. All such information is confidential and is used for peer review only. A practice that participates in utilization analysis can view its own contract analysis, particularly in capitated contracts. Since many managed care organizations will not do business with a practice that hasn't performed this type of analysis, utilization analysis can be a way of winning contracts. Utilization analysis can also be a way to identify and control the risks that a practice has with managed care contracts. It offers the means for measuring a practice's performance against regional and national databases, and identifies areas of weakness. A practice is then able to take action to improve its quality of care in those areas.

Data Collection↗
PubMed2002

[The BCL-xL and ACR-1 genes promote differentiation and reduce apoptosis in muscle fibers of mdx mice].

The effects of the human BCL-xL and ACR-1 genes on dystrophin expression in cross-striated muscle fibers (CSMF) and on CSMF viability were studied in mdx mice after ballistic cotransfection with the human dystrophin minigene. In control mice, the proportion of dystrophin-positive (D(+)) and dying CSMF were 2.1 +/- 0.1 and 2.1 +/- 0.3%, respectively. Introduction of the dystrophin minigene (20 micrograms of the pSG5dys plasmid) increased the proportions of D(+) and dying CSMF to 5.6 +/- 1.4% and 4.5 +/- 0.9%, respectively. When pSG5dys was introduced along with the pSFFV-Neo plasmid carrying the BCL-xL gene (10 micrograms of each plasmid per shot), the death of CSMF decreased to 3.7 +/- 1% and the proportion of D(+) CSMF significantly (P < 0.05) increased to 12.2 +/- 2.2%. Contransfection with the dystrophin minigene and the BCL-xL gene at 20 micrograms of each plasmid per shot did not stimulate generation of D(+) CSMF, but did reduce the CSMF death to 1.5 +/- 0.3%. Introduction of pSG5dys along with the pRc-CMV-10.1 plasmid containing the ACR-1 gene (10 micrograms of each plasmid per shot) reduced the proportion of D(+) CSMF to 1.1 +/- 0.5% and significantly reduced the proportion of dying CSMF to 0.9 +/- 0.3% as compared with the proportions observed in intact mice or in mice subjected to transfection with pSG5dys. Introduction of the pSG5dys plasmid substantially reduced the proportion of CSMF with peripheral nuclei, suggesting disturbed CSMF differentiation. After cotransfection with the human-dystrophin minigene, the BCL-xL and ACR-1 genes did not affect the extent of CSMF differentiation as compared with that observed in the case of the dystrophin minigene alone. Thus, ballistic transfection of mdx mice with the human dystrophin gene used along with the BCL-xL or ACR-1 gene was shown to suppress the death of muscle fibers and to expedite dystrophin synthesis and cell differentiation.

Animals↗
PubMed1995

Molecular cloning and functional co-expression of a Caenorhabditis elegans nicotinic acetylcholine receptor subunit (acr-2).

A number of putative nicotinic acetylcholine receptor subunit clones were isolated by screening a lambda library of Caenorhabditis elegans genomic DNA with a probe derived from the Drosophila melanogaster ard gene (a non-alpha nicotinic acetylcholine receptor subunit clone). Studies on one of these loci, acr-2, are described; acr-2 is located between sup-7 and unc-6 on the X chromosome. A full-length cDNA was isolated and sequenced. The cDNA encodes a putative non-alpha subunit of a nicotinic acetylcholine receptor that shows many of the conserved features of vertebrate and invertebrate non-alpha nicotinic acetylcholine receptor subunits. To investigate the functional expression of the subunit, the corresponding cRNA was produced, in vitro, and micro-injected into Xenopus oocytes. When expressed alone acr-2 shows no levamisole-gated channel activity. When co-expressed with a C. elegans alpha subunit (unc-38), which is itself unable to form functional homo-oligomers, acr-2 contributed to the formation of a functional channel. This is the first functional expression of a nematode nicotinic acetylcholine receptor and supports the interpretation that the differentiation between alpha and non-alpha subunits dates back to the earliest stages of the evolution of the metazoa.

Amino Acid Sequence↗
PubMed1976

Segmentation of human chromosomes induced by 5-ACR (5-azacytidine).

The 5-ACR (5-azacytidine) introduced in human lymphocyte cultures induces a lack or a delay of condensation of some chromosome segments corresponding to the G-bands. The resulting R-banding is very similar to that obtained with a 7-h treatment by BrdU, although the segmentation may be much stronger (pulverization) with high doses. However, the 5-ACR does not induce chromatid asymmetry, as BrdU does. This constitutes a new argument for considering that the segmentation and the asymmetry of chromatids depend, at least partly, on two different mechanisms, where proteins are probably involved. Another effect of 5-ACR is to increase chromosome associations by satellites, secondary constrictions, and telomeric regions.

Azacitidine↗
PubMed1999

Assessment of resident knowledge: subjective assessment versus performance on the ACR in-training examination.

RATIONALE AND OBJECTIVES: The authors assessed the ability of faculty and residents to predict the ranked performance of residents on the American College of Radiology (ACR) In-Training Examination. MATERIALS AND METHODS: Radiology faculty at Penn State Geisinger Health System (PSGHS), the Medical College of Virginia (MCV), and the University of Virginia (UVA) and residents at PSGHS and MCV ranked the expected performances of residents taking the 1997 ACR In-Training Examination. Surveyed faculty and residents were blinded to the actual performances on the examination. Forty-nine residents took the examination (21 at PSGHS, 22 at MCV, six at UVA), and 37 faculty members (11 at PSGHS, 11 at MCV, 15 at UVA) participated in the study. Correlation analysis was performed to assess the agreement between the subjective and actual ranking of residents in each residency class. RESULTS: Faculty were moderately accurate in the overall ranking of resident performances (r = 0.34). High levels of concordance for ranking individual residents correlated with accuracy in only certain cases. Differences in agreement and accuracy of the respondents existed between PSGHS and MCV (P = .0001 and .0014, respectively). The concordance of respondents increased significantly from the 1st- to the 2nd-year class at MCV (P = .0002), whereas accuracy increased significantly between these classes for the PSGHS (P = .042). CONCLUSION: Faculty are only moderately successful in ranking resident performances on the ACR In-Training Examination, and a high level of agreement is not necessarily indicative of increased accuracy. The concordance and accuracy of subjective rankings differ among residency programs and classes.

Clinical Competence↗
PubMed2002

Contact zones between chromosomal races of Mus musculus domesticus. 3. Molecular and chromosomal evidence of restricted gene flow between the CD race (2n = 22) and the ACR race (2n = 24).

The contact zone between the Ancarano (ACR; 2n = 24) and Cittaducale (CD; 2n = 22) races of Mus musculus domesticus was studied. We used chromosomes and mitochondrial DNA (mtDNA) sequences of the control region as genetic markers to detect introgression between races. In total, 76 mice were trapped at 17 localities. Cytogenetic analysis was performed on 73 mice. A segment of the control region (468 bp) was sequenced in 41 specimens. The two races are distributed parapatrically and the contact zone was identified inside a village (Pizzoli). No mixed population was found in the study area. The contact zone does not correspond to any geographical or ecological barrier but is located in a zone of potentially high density of mice. The sequence analysis clearly demonstrates genetic differentiation between races (1.4% of sequence divergence). Hybridization is rare. Evidence of introgression was found in two individuals in the contact zone: one individual of the ACR race carries a metacentric belonging to the CD race, while another ACR individual carries a CD-like haplotype. In these ecological conditions, the observed distribution pattern and the very low level of hybridization suggest the presence of a premating mechanism of reproductive isolation.

Animals↗
PubMed2003

A family of acr-coregulated Mycobacterium tuberculosis genes shares a common DNA motif and requires Rv3133c (dosR or devR) for expression.

Previous work has shown that the divergently transcribed Mycobacterium tuberculosis genes acr (hspX, Rv2031c) and acg (Rv2032) are induced under conditions of shallow standing culture and low oxygen and intracellularly within macrophages. We used a combination of computational and experimental methods to identify promoters for eight additional genes that are regulated in a similar manner and that comprise an acr-coregulated promoter (ACP) family. Transcriptional regulation of these ACP family members was evaluated by using a plasmid-based promoter-green fluorescent protein fusion system and flow cytometry. All promoters showed increased expression in shallow standing versus shaking cultures, in low- versus high-oxygen conditions, and intracellularly within macrophages versus extracellularly in tissue culture medium. However, there were quantitative differences in expression among promoters and among conditions for each promoter. A conserved 18-bp palindromic sequence motif was identified in all ACPs by Gibbs sampling-based computational analyses. Two such motifs overlap regions in the acr and acg promoters that were previously shown to be required for their expression. In addition, we found that 5% carbon dioxide was required for growth of Mycobacterium bovis BCG under microaerophilic (1.3% O(2)) culture conditions and fully prevented the growth cessation typically associated with rapid removal of oxygen. These findings are likely to be relevant to the in vivo environment and will contribute to our understanding of the pathogenesis of tuberculosis infection.

Bacteriological Techniques↗
PubMed2001

Hypothetical ratings of coronary angiography appropriateness: are they associated with actual angiographic findings, mortality, and revascularisation rate? The ACRE study.

OBJECTIVE: To determine whether ratings of coronary angiography appropriateness derived by an expert panel on hypothetical patients are associated with actual angiographic findings, mortality, and subsequent revascularisation in the ACRE (appropriateness of coronary revascularisation) study. DESIGN: Population based, prospective study. The ACRE expert panel rated hypothetical clinical indications as inappropriate, uncertain, or appropriate before recruitment of a cohort of real patients. SETTING: Royal Hospitals Trust, London, UK. PARTICIPANTS: 3631 consecutive patients undergoing coronary angiography (no exclusion criteria). MAIN OUTCOME MEASURES: Angiographic findings, mortality (n = 226 deaths), and revascularisation (n = 1556 procedures) over 2.5 years of follow up. RESULTS: The indications for coronary angiography were rated appropriate in 2253 (62%) patients. 166 (5%) coronary angiograms were performed for indications rated inappropriate, largely for asymptomatic or atypical chest pain presentations. The remaining 1212 (33%) angiograms were rated uncertain, of which 47% were in patients with mild angina and no exercise ECG or in patients with unstable angina controlled by inpatient management. Three vessel disease was more likely among appropriate cases and normal coronaries were more likely among inappropriate cases (p < 0.001). Mortality and revascularisation rates were highest among patients with an appropriate indication, intermediate in those with an uncertain indication, and lowest in the inappropriate group (log rank p = 0.018 and p < 0.0001, respectively). CONCLUSION: The ACRE ratings of appropriateness for angiography predicted angiographic findings, mortality, and revascularisation rates. These findings support the clinical usefulness of expert panel methods in defining criteria for performing coronary angiography.

Adult↗
PubMed2004

A Web-based ACR index for radiological diagnoses.

OBJECTIVE: We created an online computer system that allows radiologists to access the American College of Radiology (ACR) index for radiologic diagnoses from any Web browser. CONCLUSION: A total of 11,260 indexes (10 anatomic, 722 pathologic, 90 subanatomic, and 10,438 subpathologic) were integrated into this online system. Users can navigate the entire ACR hierarchic indexing structure with easy-to-use cascading dropdown lists. This password-protected system also allows free-text searches, ACR index searches, and bookmark functions. We have used this system in our departmental intranet for more than 2 years.

Abstracting and Indexing↗
PubMed1995

The value of the ACR 1987 criteria in very early rheumatoid arthritis.

We assessed the sensitivity and specificity of the ACR 1987 revised criteria for rheumatoid arthritis (RA) in 121 patients with recent-onset (< or = 6 months) RA, 68 with reactive arthritis (ReA), 19 with ankylosing spondylitis (AS), and 13 with psoriatic arthritis (PsA). The sensitivity of each single criterion ranged 8.3-90.9% and specificity 52.0-100%. The sensitivity of four fulfilled criteria was 83.5% and specificity 86.0%. In ReA 11.8%, AS 5.3%, and PsA 38.5% of patients fulfilled four criteria respectively. Thus at the beginning of RA, 83% of patients could be diagnosed correctly by using the ACR 1987 criteria, and the remaining 17% had seropositive and/or erosive arthritis at the onset. The suitability of the radiographic ACR criteria is discussed.

Arthritis, Psoriatic↗
PubMed2003

[Technique of PCR-ACRS for the detection of CYP21 gene mutations].

OBJECTIVE: To establish a rapid method of detecting CYP21 gene mutations. METHODS: Fifty Chinese patients with 21-hydroxylase deficiency and some of their families were investigated. Blood samples were obtained for extraction of peripheral blood lymphocytes. A search for restriction sites discriminating between the morbid and the normal in CYP21 gene was made by the computer program DNAssist. PCR-based amplication-created restriction site(PCR-ACRS) was performed at I172N and R356W which are not natural recognition sequence. In addition, I172N and R356W were analysed in five families which conform to the applicability of PCR-ACRS. RESULTS: In 50 identified 21-hydroxylase deficient Chinese patients, 21 were found to have I172 N (3 were homozygote, 18 were heterozygote); 8 were found to have R356W, all of them were heterozygote. By analysing the families, the findings were consistent with the characteristics of autosomal recessive genetic deficiency. CONCLUSION: Analysis of CYP21 gene point mutations using PCR-ACRS is relatively simple, accurate and feasible.

Adrenal Hyperplasia, Congenital↗
PubMedDate not supplied

Construct validation of the ACR 1991 revised criteria for global functional status in rheumatoid arthritis.

In order to assess the construct and discriminatory validity of the 1991 ACR functional status criteria for rheumatoid arthritis (RA), a cross-sectional analysis of 62 consecutive patients with RA (according to the American Rheumatism Association 1987 revised criteria) who were attending the outpatient clinic of rheumatology, University Hospital Zürich, was carried out. A moderate-to-strong association of the ACR criteria with pain (r = 0.54), the tender (r = 0.54) and swollen joint count (r = 0.31), grip strength (r = -0.49), C-reactive protein (r = 0.35), the HAQ disability index (r = 0.76), self-perceived global health (r = 0.58), and the Larsen radiological score (r = 0.32) was found. The mean scores of most disease parameters and all 8 domains of the health assessment questionnaire were significantly different between, and increased regularly across, the 4 classes. We conclude that the ACR 1991 functional status criteria for RA are a valid measure of the consequences of impairment and discriminate well the physical functional status.

Aged↗
PubMed1989

The ACR-NEMA Digital Imaging and communications Standard: a nontechnical description.

The purpose of this report is to present, in nontechnical terms, the purpose and history of the American College of Radiology and National Electrical Manufacturers Association (ACR-NEMA) Digital Imaging and Communications Standard (ACR-NEMA Standards Publication no. 300-1985), an explanation of what the standard is, the characteristics of the standard, possible applications of the standard, and ongoing standardization efforts. It is assumed that the reader has at least a basic understanding of the concepts and technologies described collectively as picture archiving and communication systems (PACS). For information on PACS, please refer to the NEMA PACS Primer and the list of suggested reading contained therein (for copies, write or call NEMA, 2101 L St, Suite 300, Washington, DC 20037, ATTN: Ms Cindy Fuscoe; telephone 202-457-1965).

Computer Communication Networks↗
PubMed2004

Quality assurance of clinical MRI scanners using ACR MRI phantom: preliminary results.

Clinical magnetic resonance imaging (MRI) scanners play an important role in the diagnosis of diseases and management of patient treatment. Quality assurance (QA) of the clinical MRI scanners is mandatory to obtain optimal images in a modern hospital. In this report, the phantom test for the American College of Radiology (ACR) MRI accreditation is used as the essential part of the MRI QA protocols. Seven important assessments of MR image quality are included as follows: geometric accuracy, high-contrast resolution, slice thickness accuracy, slice position accuracy, image intensity uniformity, percent signal ghosting, and low-contrast object detectability. In addition, signal-to-noise ratio and central frequency are monitored as well. The MRI QA procedures were applied to four clinical MRI scanners in our institute twice within 3 months. According to the QA results, the service engineers were more efficient in solving scanners problems when the ACR phantom test was run.

Humans↗
PubMed2006

New platyrrhine monkeys from the Solimões Formation (late Miocene, Acre State, Brazil).

We report here a new fossil primate from the late Miocene of Brazil. The material consists of a lower first molar and a maxilla with P3-4. The fossils were collected in the Solimões Formation at the locality of Patos, upper Acre River, Acre State, Brazil. The locality is assigned to the Huayquerian South American Land Mammal Age based on faunal content (late Miocene; dated to between 9 and 6 Ma). The new material is the oldest known occurrence of fossil primates in Brazil and is recognized as a new genus and species, Solimoea acrensis. Solimoea is the oldest known member of the ateline subfamily, which includes the living genera Ateles, Lagothrix, and Brachyteles. By analogy with the molar structures and diets of extant platyrrhines, Solimoea primarily had a diet of fruit, perhaps similar to that of the spider monkey, Ateles. Two other primate teeth described previously from the same formation in Bolivia document the occurrence of alouattines and cebines. One of those specimens is a late Miocene representative of the middle Miocene Colombian genus Stirtonia. The other represents one of the largest known platyrrhine primates, for which is erected a new primate genus, Acrecebus fraileyi.

Animals↗