AKAMAI Project: teleradiology in the Pacific.
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Hawaii↗
Biomedical subjects
M F Hansen
Publications and source records attributed to M F Hansen.
Serological crossreactivity between Brucella abortus and Yersinia enterocolitica 0:9 II the use of Yersinia outer proteins for the specific detection of Yersinia enterocolitica infections in ruminants.
Yersinia outer protein (YOP) preparations from Y. enterocolitica and Y. pseudotuberculosis were used as antigens in immunoblots for the detection of Yersinia infections in experimentally and naturally infected ruminants. Sera from 9 groups of animals were used: (1) 51 sera from cattle which were false-positive in the standard brucellosis serological tests, (2) 52 sera from brucellosis-negative cattle, (3) 51 sera from a deer herd in which 16 animals were positive in the brucellosis tests and Yersina species were isolated from 5 animals, (4) 50 sera from a deer herd in which sera from all animals were negative in the brucellosis tests, (5) 107 sera from brucellosis-negative cattle which were received from throughout New Zealand, (6) 30 sera from cattle naturally infected with B. abortus and from which B. abortus was isolated, (7) 55 sera from cattle naturally infected with B. abortus, (8) 26 sera from cattle experimentally infected with B. abortus, with mostly high titres in the conventional brucellosis tests, and (9) sera taken weekly from 3 cattle experimentally infected with Y. enterocolitica 0:9. In all 3 Y. enterocolitica 0:9 experimentally infected animals the antibody reactivity against major YOPs in the Y. enterocolitica and in the Y. pseudotuberculosis YOP preparation correlated well with the strength in the classical brucellosis tests and with the staining of smooth lipopolysaccharides (SLPS) in blots, thus confirming the usefulness of YOPs for the detection of Yersinia infections. Sera from naturally infected cattle and deer herds, regardless of whether they were false positive or negative in the brucellosis tests, showed high frequencies of staining in YOP blots (53-58% in cattle and 80-100% in deer), indicating a high prevalence of field infections with Yersinia species in New Zealand. In two of the three sera groups from B. abortus infected animals, antibodies against YOPs were detected with high frequency, showing that dual infections may be common and may interfere with differential serological testing.
Animals↗
Serological crossreactivity between Brucella abortus and Yersinia enterocolitica 0:9 I immunoblot analysis of the antibody response to Brucella protein antigens in bovine brucellosis.
Sera from three groups of Brucella abortus infected cattle were examined in immunoblots with the following antigens: sodium dodecyl sulfate/mercapto ethanol (SDS/ME) extracts of two rought B. abortus strains (45/20 and RB51) and rough B. ovis, smooth lipopolysaccharides (SLPS) from B. abortus strain 99 and Y. enterocolitica 0:9, and a cytoplasmic extract from smooth B. abortus strain 19-S. The sera groups were: (1) 26 sera from animals, experimentally infected with B. abortus strain 544, which were all positive in the conventional brucellosis serological tests; (2) 152 sera from naturally infected cattle herds with varying titres in the conventional brucellosis tests, and (3) 30 sera from naturally infected cattle with varying titres in the conventional brucellosis tests and from which B. abortus was cultured. B. abortus strain 99 and Y. enterocolitica serotype 0:9 SLPS staining showed up frequently in all sera groups and correlated well with the strength in the conventional brucellosis tests, confirming the immunodominance of SLPS in B. abortus infections. Another immunodominant component of 50-80 kDa was found in the rough B. abortus 45/20 antigen preparation but not in the B. abortus RB51 and in the B. ovis cell extracts. This component was also recognised by sera from Y. enterocolitica 0:9 infected cattle and is probably a protein-lipopolysaccharide complex. Although many of the sera from B. abortus infected cattle with high titres in the conventional brucellosis tests showed complex protein staining patterns in blots, no protein bands other than the 50-80 kDa bands were found to be immunodominant.
Animals↗
Glenohumeral ligaments and shoulder capsular mechanism: evaluation with MR arthrography.
PURPOSE: To evaluate the efficacy of magnetic resonance (MR) arthrography in identification of the glenohumeral ligaments (GHLs) and to determine the location of abnormalities of the GHL, joint capsule, and labrum. MATERIALS AND METHODS: MR arthrograms were evaluated retrospectively in 46 patients with a history of shoulder instability, impingement syndrome, or pain of unknown cause. Imaging findings were correlated with surgical observations. RESULTS: The superior, middle, and inferior GHLs were identified on MR arthrograms in 39 (85%), 39 (85%), and 42 (91%) of the 46 patients, respectively. In diagnosis of tears of the superior, middle, and inferior GHLs, MR arthrography had a sensitivity of 100%, 89%, and 88% and a specificity of 94%, 88%, and 100%, respectively. CONCLUSION: Findings at MR arthrography can help accurate identification and demonstration of the integrity of the GHL and labrum and can help in staging of abnormalities. The large number of abnormalities depicted in the middle and inferior GHLs suggests that both might be important in the maintenance of glenohumeral joint congruity.
Adult↗
Identification and characterization of immunodominant antigens during the course of infection with Brucella ovis.
The seroresponse against Brucella ovis of 8 intrapreputially and 6 intravenously infected rams and 9 ewes infected through mating was analyzed by electrophoretic immunoblotting. Additionally, 87 sera from chronically infected rams that were shedding B. ovis in their semen, 226 sera from rams belonging to infected flocks, and 324 sera from false-positive complement fixation test (CFT) reactors were examined. In all infected animals, antibody reactivity was predominantly found against 5 B. ovis components of 8-12, 17, 19, 29, and 63 kD, of which the 29-kD antigen was most dominant in the seroresponse. Antibodies to the 29-kD component were present in 93-100% of the infected sheep in each infected group, whereas the frequency of antibodies to the 4 other components varied considerably among and within the different groups. No reactivity against the 29-kD antigen was found in the false-positive CFT reactors. By using monoclonal antibodies against known bacterial macromolecules, the immunodominant antigens were identified as rough lipopolysaccharide (8-12 kD), outer membrane proteins (17, 19, 29 kD), and a heat-shock protein (63 kD).
Animals↗
Molecular genetics and cytogenetics of sarcomas.
It was only 25 years ago that the concept of cancer as a genetic disease began to gain widespread acceptance. It is encouraging to note that recurrent molecular pathways critical to the genesis and evolution of human sarcomas are being elucidated through molecular and cytogenetic techniques. It is also important to remember that molecular genetics and cytogenetics are still in their infancy. In this review, we have barely touched on the tremendous amount of information that has developed in sarcoma genetics and cytogenetics. As this synergistic evolution of genetic changes in human sarcomas becomes better understood, new and better therapeutic strategies aimed at circumventing these processes will be developed. But the biologic and genetic redundancies intrinsic to mammalian cells continue to allow tumors to adapt and resist chemotherapeutic agents. Understanding sarcoma progression at the molecular level will allow, therefore, for the identification of better diagnostic markers, the development of new therapeutic strategies, and the ability to select the most effective and least toxic combination of antitumor therapies for a patient.
Genes, Retinoblastoma↗
Hereditary multiple exostosis and chondrosarcoma: linkage to chromosome II and loss of heterozygosity for EXT-linked markers on chromosomes II and 8.
Hereditary multiple exostosis (EXT) is an autosomal dominant disorder characterized by bony exostoses at the ends of the long bones. Linkage studies have recently suggested that there are three chromosomal locations for EXT genes, 8q24.1 (EXT1), the pericentric region of 11 (EXT2), and 19p (EXT3). As part of a larger study to determine the frequencies of the three EXT types in the United States, we have ascertained a large multigenerational family with EXT and one family member with a chondrosarcoma. This family demonstrated linkage of the disease to chromosome 11 markers. The constitutional and tumor DNAs from the affected family member were compared using short-tandem-repeat markers from chromosomes 8, 11, and 19. Loss of heterozygosity (LOH) in the tumor was observed for chromosome 8 and 11 markers, but chromosome 19 markers were intact. An apparent deletion of the marker D11S903 was observed in constitutional DNA from all affected individuals and in the tumor sample. These results indicate that the EXT2 gene maps to the region containing marker D11S903, which is flanked by markers D11S1355 and D11S1361. Additional constitutional and chondrosarcoma DNA pairs from six unrelated individuals, two of whom had EXT, were similarly analyzed. One tumor from an individual with EXT demonstrated LOH for chromosome 8 markers, and a person with a sporadic chondrosarcoma was found to have tumor-specific LOH and a homozygous deletion of chromosome 11 markers. These findings suggest that EXT genes may be tumor-suppressor genes and that the initiation of tumor development may follow a multistep model.
Chondrosarcoma↗
Identification of a polymorphism in intron 2 of the p53 gene.
A polymorphism in intron 2 of the p53 gene was identified by single-strand conformation polymorphism analysis. The result is a G-to-C transversion at bp +38 following the splice donor site of exon 2.
Alleles↗
Shoulder impingement syndrome: diagnostic accuracy of magnetic resonance imaging and radiographic signs.
Shoulder impingement syndrome is commonly encountered in orthopaedics. In a blinded retrospective study, magnetic resonance imaging and roentgenographic signs in 41 patients with clinical signs of impingement syndrome were compared with 40 control patients. Statistically significant differences between the groups included the absence of subarcromial fat, as well as the presence of a supraspinatus tear, subacromial osteophytes, and a decreased coracohumeral distance. Other signs reported to occur in patients with impingement syndrome did not vary significantly in the population studied.
Adult↗
Chronic ankle instability: evaluation with MR arthrography, MR imaging, and stress radiography.
PURPOSE: To compare the efficacy of conventional magnetic resonance (MR) imaging, MR arthrography, and stress radiography in the detection of lateral collateral ligament abnormalities in patients with chronic ankle instability. MATERIALS AND METHODS: Seventeen patients with chronic lateral ankle instability underwent stress radiography, MR imaging, and MR arthrography after intraarticular injection of gadopentetate dimeglumine. Imaging findings were correlated with surgical findings. RESULTS: The anterior talofibular (ATF) ligament was torn in 14 patients, and the calcaneofibular (CF) ligament was torn in 10. MR arthrography was more accurate and sensitive in the detection of ATF tears than was MR imaging or stress radiography (P < or = .05). Associated injuries were detected with both MR imaging and MR arthrography. CONCLUSION: MR arthrography is a sensitive technique for detecting and staging tears of the lateral collateral ligaments.
Adult↗
Detection and staging of chondromalacia patellae: relative efficacies of conventional MR imaging, MR arthrography, and CT arthrography.
OBJECTIVE: Chondromalacia patellae is a condition characterized by softening, fraying, and ulceration of patellar articular cartilage. We compare the sensitivity, specificity, and accuracy of conventional MR imaging, MR arthrography, and CT arthrography in detecting and staging this abnormality. SUBJECTS AND METHODS: Twenty-seven patients with pain in the anterior part of the knee were prospectively examined with MR imaging, including T1-weighted (650/16), proton density-weighted (2000/20), T2-weighted (2000/80), and spoiled two-dimensional gradient-recalled acquisition in the steady state (SPGR/)/35 degrees (51/10) with fat saturation pulse sequences. All were also examined with T1-weighted MR imaging after intraarticular injection of dilute gadopentetate dimeglumine and with double-contrast CT arthrography. Each imaging technique was evaluated independently by two observers, who reached a consensus interpretation. The signal characteristics of cartilage on MR images and contour abnormalities noted with all imaging techniques were evaluated and graded according to a modification of the classification of Shahriaree. Twenty-six of the 54 facets examined had chondromalacia shown by arthroscopy, which was used as the standard of reference. The sensitivity, specificity, and accuracy of each imaging technique in the diagnosis of each stage of chondromalacia patellae were determined and compared by using the McNemar two-tailed analysis. RESULTS: Arthroscopy showed that 28 facets were normal. Grade 1 chondromalacia patellae was diagnosed only with MR and CT arthrography in two (29%) of seven facets. Intermediate (grade 2 or 3) chondromalacia patellae was detected in two (13%) of 15 facets with T1-weighted and SPGR MR imaging, in three (20%) of 15 facets with proton density-weighted MR imaging, in seven (47%) of 15 facets with T2-weighted MR imaging, in 11 (73%) of 15 facets with CT arthrography, and in 12 (80%) of 15 facets with MR arthrography. Grade 4 was detected in three (75%) of four facets with T1-, proton density-, and T2-weighted MR imaging, two (50%) of four facets with SPGR MR imaging, and four (100%) of four facets with MR and CT arthrography. Thus, all imaging techniques were insensitive to grade 1 lesions and highly sensitive to grade 4 lesions, so that no significant difference among the techniques could be shown. CONCLUSION: All imaging techniques studied had high specificity and accuracy in the detection and grading of chondromalacia patella; however, both MR arthrography and CT arthrography were more sensitive than T1-weighted, proton density-weighted, and SPGR with fat saturation MR imaging for showing intermediate grades of chondromalacia patellae. Although the arthrographic techniques were not significantly better than T2-weighted imaging, the number of false-positive diagnoses was greatest with T2-weighted MR imaging.
Adult↗
The retinoblastoma gene and its significance.
The first human tumour suppressor gene, the Retinoblastoma Susceptibility gene (RB1) was first demonstrated in retinoblastoma, a rare paediatric eye tumour which has been studied extensively over the last century. Genetic studies of retinoblastoma have yielded unique insights into familial cancer syndromes and the mechanisms of oncogenesis by tumour suppressor genes such as the RB1 gene. In this view, we will summarize past research into the genetics of retinoblastoma that led to the discovery of the RB1 gene and discuss the influence these results have had on the field of cancer research. In addition, we will discuss current research into RB1 as it relates to cancer and its potential for new therapies.
Animals↗
Doppler analysis of hemodialysis grafts: resistive index as a predictor of stenosis.
A series of six hemodialysis vascular access patients was evaluated with duplex Doppler sonography and angiography to identify Doppler sonographic parameters that are predictors of venous outflow stenosis. This preliminary series indicates that no venous outflow stenosis was present angiographically when the resistive index gradient across the venous anastomosis is less than or equal to zero and a significant venous outflow stenosis (50 to 100%) was present when the resistive index gradient is 0.15 or greater (P = 0.002, r = 0.963). Doppler acquisition of resistive index gradients across regions of venous outflow is a promising, noninvasive means of rapid radiologic evaluation of hemodialysis graft patients, especially when the need for angiography is equivocal.
Arteriovenous Shunt, Surgical↗
A method to isolate DNA from small archival tissue samples for p53 gene analysis.
The tumor suppressor gene p53 is involved in predisposition to a variety of human cancers, including those from Li-Fraumeni cancer family syndrome patients. Studies of inheritance of p53 germline mutations require confirmation of the mutation in the tumors from family members. These studies, as well as other retrospective studies of tumor specific mutations, are often hampered by a lack of available fresh or frozen tumor tissue samples for DNA extraction to confirm the suspected p53 mutation. Here we describe a simple technique for DNA isolation that permits mutational analysis of p53 from minimal amounts of paraffin-embedded archival tissue samples.
Base Sequence↗
Glenoid labral tears: prospective evaluation with MRI imaging, MR arthrography, and CT arthrography.
OBJECTIVE: We prospectively compared MR imaging, MR arthrography, and CT arthrography to determine the sensitivity of each technique in detecting glenoid labral tears and in determining whether the labrum is detached or degenerated. SUBJECTS AND METHODS: Thirty patients 19-39 years old (mean, 27 years old) who had either signs and symptoms of shoulder instability or shoulder pain of unexplained origin were referred for diagnostic imaging. Each patient underwent MR imaging, followed by MR arthrography after intraarticular injection of 25 ml of a dilute solution of gadopentetate dimeglumine. Twenty-eight of thirty patients underwent CT arthrography after intraarticular injection of air and radiographic contrast material. Each patient also underwent arthroscopy or open surgery. RESULTS: At surgery, labral tears were found in 28 patients; a detached fragment was found in 26 patients. The labrum was found to be degenerated in 18. A labral tear was detected on MR images in 26 (93%) of 28, on MR arthrograms in 27 (96%) of 28, and on CT arthrograms in 19 (73%) of 26. A detached labral fragment was detected on MR images in 12 (46%) of 26, on MR arthrograms in 25 (96%) of 26, and on CT arthrograms in 13 (52%) of 25. Labral degeneration was detected on MR images in two (11%) of 18, on MR arthrograms in 10 (56%) of 18, and on CT arthrograms in four (24%) of 17. MR arthrography was the best of the three imaging techniques for showing the inferior part of the glenoid labrum and inferior glenohumeral ligament. CONCLUSION: MR arthrography and MR imaging both showed labral tears with greater sensitivity than CT arthrography did. MR arthrography was the most sensitive of the three techniques for detecting a detached labral fragment and labral degeneration. Furthermore, MR arthrography afforded the best visualization of the inferior part of the labrum and the inferior glenohumeral ligament. MR imaging and MR arthrography also enabled direct visualization of rotator cuff disease and other unsuspected associated abnormalities.
Adult↗
Preliminary assessment of computed tomography and satellite teleradiology from Operation Desert Storm.
Computed tomography at military transportable hospitals was used for the first time during the recent Operation Desert Storm in the Saudi Arabian desert. Scan quality was excellent and the scans proved clinically important in patient management. A teleradiology link via satellite to the U.S. mainland was also successfully employed. The objectives of the teleradiology link were to validate the concept distant interpretation of images obtained on the battlefield and to provide specialty radiology consultation. This technology shows great promise for future applications, both for combat casualty care and for civilian disaster medical support operations.
Hospitals, Military↗
Molecular genetic considerations in osteosarcoma.
Osteosarcoma tumorigenesis is consistent with a model by which tumorigenesis results if both alleles at the retinoblastoma susceptibility locus (RBI) are altered. Additional genetic evidence strongly suggests that another obligate event in osteosarcoma tumorigenesis is the homozygous alteration of another gene, p53. Both the RB1 gene and p53 have been proposed to act as tumor-suppressor genes, suggesting that, in this instance, tumorigenesis is the result of the loss of gene function of these two genes, rather than a gain of function.
Base Sequence↗