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Classen CN, Warren R, Richardson M, Hauman JH, Gie RP, Ellis JH, van Helden PD, Beyers N. Impact of social interactions in the community on the transmission of tuberculosis in a high incidence area. Thorax 1999; 54:136-40. [PMID: 10325918 PMCID: PMC1745413 DOI: 10.1136/thx.54.2.136] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Tuberculosis (TB) is transmitted by close contact with an infectious person. It is assumed that close contact occurs amongst household members and that contact outside the house is "causal" and does not play a major role in the transmission of TB. METHODS This study was conducted in an impoverished area with a high incidence of TB and a low HIV seropositive prevalence. Thirty three households with 84 TB patients were identified between February 1993 and April 1996 and the transmission of TB was studied by combining Mycobacterium tuberculosis fingerprinting with in depth sociological interviews. RESULTS Forty two strain genotypes were identified in the 84 patients. In 15 households all the patients had identical strains, in nine households all the patients had different strains, and in nine households some patients had identical strains and one had a different strain. In 26 houses at least one patient had a strain which formed part of a larger community cluster and in 12 of these households the patient(s) had contact with a community member who had the identical strain. In 58% of the cases the contact took place while drinking in social groups. CONCLUSION In high incidence areas contact outside the household may be important for the transmission of TB. This contact often takes place during recreation which, in the case of this study of impoverished people, consisted of drinking in social groups. Social interaction patterns should be studied and understood for effective implementation of control strategies.
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Lin J, Jacobson JA, Jamadar DA, Ellis JH. Pigmented villonodular synovitis and related lesions: the spectrum of imaging findings. AJR Am J Roentgenol 1999; 172:191-7. [PMID: 9888766 DOI: 10.2214/ajr.172.1.9888766] [Citation(s) in RCA: 96] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Platt JF, Reige KA, Ellis JH. Aortic enhancement during abdominal CT angiography: correlation with test injections, flow rates, and patient demographics. AJR Am J Roentgenol 1999; 172:53-6. [PMID: 9888738 DOI: 10.2214/ajr.172.1.9888738] [Citation(s) in RCA: 96] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The goal of our study was to determine the effect of contrast material injection rate and patient demographic variables on vascular enhancement for abdominal CT angiography and compare test injection results with actual patterns of vascular enhancement. SUBJECTS AND METHODS One hundred twenty-five patients underwent abdominal CT angiography. For each patient, CT attenuation values (Hounsfield units) of the aorta were determined before and after IV contrast administration, every 3 sec between 21 and 60 sec. A peak aortic enhancement value and the time needed to reach peak and aortic enhancement thresholds of 150 and 200 H were determined. All patients received 150 ml of nonionic contrast material at 3 ml/sec in 25 patients and 4 ml/sec in 100 patients. A test injection of 15 ml was used to compute a scan delay in 46 patients. Patient age, sex, weight, injection rate, and test injection results were compared with vascular enhancement patterns. RESULTS For the 125 patients, the mean aortic enhancement at each time point was greater than 150 H. Patient weight was inversely correlated (r2 = -.62) with aortic enhancement. The test injection did not accurately predict actual aortic enhancement peak value or time. Test injection delay time was significantly correlated with time to reach aortic enhancement thresholds of 150 and 200 H. The 4 ml/sec rate resulted in a higher peak aortic enhancement (320+/-58 H versus 281+/-49 H) (mean +/- SD, p < .01) that was reached quicker than with the 3 ml/sec injection rate (45+/-5 sec versus 52+/-5 sec) (p < .01). Injecting at 4 ml/sec resulted in greater aortic enhancement values at 24-45 sec, whereas 3 ml/sec produced significantly better aortic enhancement at 54-60 sec. CONCLUSION The test injection correlated better with time to reach specific aortic enhancement thresholds than with time to peak aortic enhancement. For a given amount of contrast material, faster injection rates resulted in greater vascular enhancement that occurred earlier.
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Ellis JH, Sutmuller RP, Sims MJ, Cooksley S. Functional analysis of the T-cell-restricted protein tyrosine kinase Txk. Biochem J 1998; 335 ( Pt 2):277-84. [PMID: 9761724 PMCID: PMC1219779 DOI: 10.1042/bj3350277] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
T lymphocytes express a range of tyrosine kinases that are involved in signalling processes driving cell activation, proliferation and differentation. Two tyrosine kinases expressed only in T cells, the Itk/Emt and Txk gene products, are members of the Tec family of kinases. The role of Tec kinases in cellular function is poorly understood, although a Tec kinase specific to B cells, Btk, is essential for B-cell development. To explore the contribution of the T-cell-specific Tec kinases to lymphocyte function, we have expressed human Txk in the baculovirus system and conducted the first characterization of its activity. We find that Txk exhibits a substrate preference in vitro quite distinct from that of the major T-cell kinases Lck and ZAP70, suggesting that Tec-family kinases might act on a distinct range of substrates. We also investigated the interactions of Txk with the cytoplasmic domains of the key signalling molecules CD3zeta, CD28 and CTLA4 and find that none of these are phosphorylated by Txk, nor are they ligands for the SH2 or SH3 domains of Txk. We conclude that it is unlikely that Txk has a role in the early signal transduction events associated with these key pathways controlling T-cell activation.
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Platt JF, Ellis JH, Korobkin M, Reige K. Helical CT evaluation of potential kidney donors: findings in 154 subjects. AJR Am J Roentgenol 1997; 169:1325-30. [PMID: 9353451 DOI: 10.2214/ajr.169.5.9353451] [Citation(s) in RCA: 100] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVE The purpose of our study was to assess renal helical CT (RHCT) as the primary imaging technique in the evaluation of potential kidney donors. SUBJECTS AND METHODS Unenhanced and enhanced (3-mm collimation) RHCT was performed in 154 kidney donors using 125-150 ml of i.v. contrast material at an injection rate of 3 or 4 ml/sec and a pitch of 1.3-2. Scans were reconstructed at 1.5-mm intervals for a three-dimensional image. RHCT images were compared with the results of renal arteriography (RA) (50 subjects) and surgery (117 subjects). RESULTS CT and surgical findings agreed in 95% of patients (111/117), with five cases of missed accessory arteries (all < 2 mm in diameter) and one case of a missed early division of the main artery. In the 50 subjects who underwent CT and RA, imaging revealed concordance in 96% of 100 kidneys. One small accessory artery was not detected by CT (origin from the common iliac artery). RA did not detect accessory arteries in three subjects. All 22 kidneys with early dividing main arteries (< 1.5 cm from the aortic origin) were identified by both RHCT and RA. Axial and three-dimensional CT images were complementary: five small accessory arteries were seen well only on the axial sections, whereas four early dividing arteries and two cases of renal artery stenosis were prospectively identified only on the three-dimensional images. Twenty-five renal vein anomalies were detected only by CT. In the full series of 154 subjects, nonvascular renal findings included renal calculi (n = 11), cysts (n = 12), duplicated ureters (n = 6), horseshoe kidney (n = 1), and pelvic kidney (n = 1). CONCLUSION RHCT can be the primary imaging technique in the assessment of potential kidney donors, reducing the number of examinations as well as the risk and cost of imaging in these subjects.
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Cohan RH, Bullard MA, Ellis JH, Jan SC, Francis IR, Garner WL, Dunnick NR. Local reactions after injection of iodinated contrast material: detection, management, and outcome. Acad Radiol 1997; 4:711-8. [PMID: 9365749 DOI: 10.1016/s1076-6332(97)80073-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
RATIONALE AND OBJECTIVES The authors assessed the frequency, sequelae, and risk factors of extravasation of intravenously administered iodinated contrast media. MATERIALS AND METHODS All patients with local reactions after intravenous injection of contrast media between November 1994 and December 1996 were studied. Comparison was made with data obtained from a control group of 100 patients with no local reactions who underwent contrast material-enhanced computed tomography (CT). RESULTS Local reactions were reported in 56 (0.25%) of 22,254 patients who received intravenous injections of iodinated contrast media. Fifty-one patients experienced extravasation, and five patients experienced local irritation in the absence of clinically detectable extravasation. Extravasation occurred during CT (n = 46), urography (n = 4), and venography (n = 1). Contrast material was nonionic in 37 cases and conventional ionic in 14 cases of extravasation. Extravasated volumes exceeded 30 mL in 22 patients and 100 mL in six patients. Forty-five (80%) of 56 patients with local reactions had complete resolution of symptoms within 24 hours. Only four patients had symptoms for more than 48 hours. No surgery was required. Compared with the control group, patients with extravasation were significantly more likely to have been injected with small-bore catheters (21 or 22 gauge) and to have been injected at low or high rates. CONCLUSION Symptoms of contrast medium extravasation usually resolve quickly. In patients with extravasation, injections are more likely to have been performed with techniques that vary from normal practice.
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Ellis JH, Abbott RL, Brick DC, Weber P. Liability issues associated with PRK and the excimer laser. Surv Ophthalmol 1997; 42:279-82. [PMID: 9406374 DOI: 10.1016/s0039-6257(97)00093-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Given the elective nature of photorefractive keratectomy (PRK), the high expectations of patients, and misconceptions of the general public about refractive surgery, the use of the excimer laser for PRK opens the door to new liability risks for ophthalmologists and, in the comanagement environment, referring optometrists. The authors discuss informed consent, marketing, comanagement, and off-label use guidelines and protocols to help protect ophthalmologists against claims and better defend those that might arise.
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Platt JF, Francis IR, Ellis JH, Reige KA. Liver metastases: early detection based on abnormal contrast material enhancement at dual-phase helical CT. Radiology 1997; 205:49-53. [PMID: 9314961 DOI: 10.1148/radiology.205.1.9314961] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
PURPOSE To assess whether contrast material enhancement findings on computed tomographic (CT) scans are useful in determination of the risk for development of hepatic metastases. MATERIALS AND METHODS Dual-phase helical CT scans were obtained in 80 patients with nonhepatic cancer and no hepatic metastases visible at CT. Attenuation was measured on scans obtained at 25 and 40 seconds. Peak liver attenuation was determined in all cases. Unenhanced scans were obtained in 35 patients. The ratio of liver attenuation at 25 and 40 seconds to peak liver attenuation, liver enhancement values at 25 and 40 seconds, and ratio of liver enhancement at 25 and 40 seconds to peak liver enhancement were determined. RESULTS Liver metastases developed during 18-month follow-up in 22 patients. The 25- and 40-second liver enhancement values and the liver enhancement and attenuation ratios were higher in these patients than in those who did not develop metastases (P < .01). Enhancement values and ratios were more accurate than densitometric measurements for predicting development of metastases. Use of an optimal threshold (0.40 or greater) for the 40-second enhancement ratio resulted in a sensitivity of 75%, specificity of 96%, and overall accuracy of 89%. CONCLUSION CT measurements may help in the prediction of risk for subsequent development of hepatic metastases.
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Ellis JH, Beyers N, Bester D, Gie RP, Donald PR. Sociological and anthropological factors related to the community management of tuberculosis in the Western Cape communities of Ravensmead and Uitsig. S Afr Med J 1997; 87:1047-51. [PMID: 9323429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
OBJECTIVE To determine the sociocultural understanding of tuberculosis among patients and their household members. DESIGN Qualitative descriptive study. SETTING Two adjacent Western Cape suburbs with a population of approximately 35,000, a tuberculosis incidence of > 1,000/100,000 and a surface area of 2.42 km2. SUBJECTS Twenty-three adult patients on treatment for tuberculosis and their adult household members. INTERVENTIONS None. METHODOLOGY Consecutive selected adult tuberculosis patients and their household members were interviewed with an open-ended interview schedule. General household and community conditions and non-verbal responses were recorded. RESULTS There were relatively affluent but also severely deprived households with severe overcrowding. Substance abuse was common. Patients had limited understanding and knowledge about health, hygiene and the cause of tuberculosis. There was a perception of both physical and social distance between patients and health care providers. All patients relied exclusively on the conventional biomedical curative approach of the medical system to deal with tuberculosis.
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Cohan RH, Ellis JH. Iodinated contrast material in uroradiology. Choice of agent and management of complications. Urol Clin North Am 1997; 24:471-91. [PMID: 9275974 DOI: 10.1016/s0094-0143(05)70397-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Many conditions seen by urologists require imaging examinations with iodinated radiographic contrast material as a key part of the primary evaluation of the patient. A basic understanding of contrast media, risks of administration, choice of agents, and premedication regimens for high-risk patients, is beneficial in helping patients prepare for their examinations. Urologists may be the primary physicians administering contrast material or may be working with radiologists in the care of patients receiving contrast agents. Because contrast reactions may occur unexpectedly, even during examinations in which the agents are not given intravenously, urologists should be able to recognize and treat the various types of adverse reactions.
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Platt JF, Francis IR, Ellis JH, Reige KA. Difference in global hepatic enhancement assessed by dynamic CT in normal subjects and patients with hepatic metastases. J Comput Assist Tomogr 1997; 21:348-54. [PMID: 9135639 DOI: 10.1097/00004728-199705000-00003] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
PURPOSE Our goal was to determine if there are differences in liver densitometry parameters using helical CT between normal subjects and subjects with liver metastases. METHOD One-hundred fifty subjects (64 with normal livers and 86 with CT-visible hepatic metastases) underwent dual phase helical scanning of the liver. Images were obtained in the "arterial" (early) and "venous" (late) phases of hepatic enhancement. Densitometry measurements were obtained from the liver (distinct from obvious lesions or vessels) and aorta at 25, 40, 75, and 90 s. Enhancement values at the same time points were calculated in 73 subjects in whom noncontrast images of the liver were available. A peak liver densitometry value was also determined. Several ratios were determined for each time point: the liver/aortic ratio (L/A), liver/liver peak ratio (L/P), liver enhancement/aortic enhancement ratio (LE/AE), and liver enhancement/liver peak enhancement ratio (LE/LPE). The degree of tumor burden in the hepatic metastatic group was assessed in each case. RESULTS Values for L/A, L/P, LE/AE, and LE/LPE at 25 and 40 s were significantly (p < 0.05) higher in the liver metastases group than the normal liver group. Enhancement ratios were even more elevated in breast cancer, which can have hypervascular metastases. These CT parameters did not show significant differences when analyzed according to the degree of hepatic metastatic tumor burden. All densitometry parameters and ratios obtained at 75 and 90 s were not significantly different between the two groups. CONCLUSION In the early phase of bolus intravenous contrast agent administration, the visually normal portion of the liver parenchyma in patients with hepatic metastases enhances to a greater degree than the liver in normal subjects. This may reflect generalized increased hepatic arterial flow in tumor-bearing livers and has the potential to increase the sensitivity of CT for detection of hepatic metastases.
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Platt JF, Rubin JM, Ellis JH. Lupus nephritis: predictive value of conventional and Doppler US and comparison with serologic and biopsy parameters. Radiology 1997; 203:82-6. [PMID: 9122420 DOI: 10.1148/radiology.203.1.9122420] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
PURPOSE To compare conventional and Doppler ultrasound (US) with clinical and biopsy parameters used to assess disease activity and outcome in lupus nephritis and to assess the predictive value of US. MATERIALS AND METHODS Thirty-four patients with lupus nephritis prospectively underwent laboratory and US analysis at the time of renal biopsy. US parameters were renal length, relative echogenicity, and resistive index (RI). Laboratory parameters were serum creatinine level, urinary protein level, and serum markers of disease activity. Biopsy parameters were activity index, chronicity index, and assessment of the tubulointerstitium of the kidney. Follow-up data were obtained in all patients for at least 1 year. RESULTS Ten patients with elevated RI (>0.70) had significantly (P <.05) higher chronicity indexes and creatinine levels than the 24 patients with a more normal RI. RI correlated significantly (P <.05) with creatinine level, chronicity index, and presence of interstitial disease. Only RI and chronicity index were statistically significant predictors of a poor renal outcome. Abnormalities at conventional US were not predictive of renal outcome. A normal RI predicted a better renal outcome whether or not creatinine level was elevated. CONCLUSION Renal Doppler US may be of greatest clinical utility when its results are apparently discordant with renal functional assessment by allowing identification of patients with higher likelihood of subsequent improvement or worsening of renal status.
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Platt JF, Yutzy GG, Bude RO, Ellis JH, Rubin JM. Use of Doppler sonography for revealing hepatic artery stenosis in liver transplant recipients. AJR Am J Roentgenol 1997; 168:473-6. [PMID: 9016229 DOI: 10.2214/ajr.168.2.9016229] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE The goal of our study was to evaluate the use of duplex Doppler sonography for revealing hepatic artery stenosis (HAS) in patients who have undergone liver transplantation. MATERIALS AND METHODS Forty-six patients with spectral Doppler waveforms obtained from the hepatic artery and with subsequent arteriography were reviewed retrospectively. Arterial waveforms, resistive indexes (RIs), and systolic acceleration times (SATs) were evaluated by one reviewer who was unaware of the arteriographic findings. The mean interval between the two examinations was 2.8 days. Arteriograms that revealed a stenosis of greater than 50% were classified as abnormal. RESULTS Of the 46 patients, 21 (46%) had a significant stenosis. Patients who had HAS had significantly (p < .05) prolonged SATs (0.08 +/- 0.03 sec versus 0.06 +/- 0.02 sec) and reduced RIs (0.49 +/- 0.05 versus 0.66 +/- 0.05) compared with patients who did not have HAS. Optimal thresholds for HAS detection were RIs less than 0.55 and SATs greater than 0.08 sec. HAS was found in 14 of 15 patients who had both abnormal RIs and SATs. Of the remaining 31 patients, 12 had abnormal values for RI or SAT. Of these 12 patients, three had HAS. Thus, 19 patients had normal RIs and SATs; however, four of these patients were found to have an arterial stenosis. In our 46 patients, abnormal values for both RI and SAT were 67% sensitive and 96% specific for stenosis. When at least one abnormal value was found on Doppler imaging, sensitivity and specificity for stenosis were 81% and 60%, respectively. CONCLUSION Duplex Doppler imaging can noninvasively reveal HAS. Abnormal values for both RI and SAT proved to be a more accurate predictor of stenosis than either RI or SAT as independent parameters.
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Bullard MA, Cohan RH, Francis IR, Ellis JH, Jan SH, Dunnick NR. Extravasation of intravenous contrast material: Incidence, management, outcome. Acad Radiol 1996. [DOI: 10.1016/s1076-6332(96)80056-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Cohan RH, Leder RA, Ellis JH. Treatment of adverse reactions to radiographic contrast media in adults. Radiol Clin North Am 1996; 34:1055-76. [PMID: 8784396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Prompt recognition and treatment can be invaluable in blunting an adverse response of a patient to radiographic contrast material and may prevent a reaction from becoming severe or even life-threatening. Radiologists and their staff should review treatment procedures regularly (at least annually) so that each staff in attendance can accomplish his or her role efficiently. Knowledge, training, and preparation are crucial in guaranteeing appropriate and aggressive therapy in the event of an adverse contrast-related event.
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Cohan RH, Ellis JH, Garner WL. Extravasation of radiographic contrast material: recognition, prevention, and treatment. Radiology 1996; 200:593-604. [PMID: 8756899 DOI: 10.1148/radiology.200.3.8756899] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Platt JF, Ellis JH, Reige KA. Assessment of renal function with computed tomographic densitometry measurements. Acad Radiol 1996; 3:718-23. [PMID: 8883511 DOI: 10.1016/s1076-6332(96)80409-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
RATIONALE AND OBJECTIVES We assessed the relationship between multiple renal computed tomographic (CT) densitometry parameters and renal function. METHODS Three hundred seventy-three patients underwent standardized helical CT of the abdomen. The ratio of mean attenuation in the renal cortex to mean attenuation in the aorta (KAR), the products of mean renal cortical attenuation with CT-estimated renal volume (KVP), and the patient's weight (KWP) were derived from scans obtained 90 sec (n = 373) and 30 sec (n = 108) after initiation of intravenous contrast material administration. These densitometry parameters were compared with renal function measured by serum level of creatinine and creatinine clearance (CrCl). RESULTS Among the 373 patients in the study, we found statistically significant differences (p < .01) between the patients with normal renal function (CrCl > or = 60 ml/min, n = 300) and the patients with abnormal renal function (CrCl < 60 ml/min, n = 73) for the KAR, KVP, and KWP. The KAR was the parameter best correlated with CrCl and was an independent predictor of renal function from the patient's age, weight, and renal volume. Fifty-three patients with a KAR less than 1 had significantly worse renal function (CrCl = 60 +/- 21 ml/min) than the patients with a KAR greater than or equal to 1 (CrCl = 95 +/- 31 ml/min). Only 4% of patients with normal renal function had a KAR less than 1. A threshold value of KAR less than 1 had a sensitivity of 55%, a specificity of 96%, a positive predictive value of 75%, and a negative predictive value of 90% for predicting renal dysfunction. CT parameters obtained at 30 sec were less useful than parameters at 90 sec. CONCLUSION In patients undergoing clinically requested CT scanning, renal densitometry analysis can be used to depict patients with normal renal function; however, it has a high false-negative rate in depicting patients with diminished renal function.
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Ellis JH, Cohan RH, Sonnad SS, Cohan NS. Selective use of radiographic low-osmolality contrast media in the 1990s. Radiology 1996; 200:297-311. [PMID: 8685315 DOI: 10.1148/radiology.200.2.8685315] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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Marx MV, Ellis JH. Radiation protection of the hand in interventional radiology: should it fit like a glove? Radiology 1996; 200:24-5. [PMID: 8657919 DOI: 10.1148/radiology.200.1.8657919] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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Platt JF, Bude RO, Ellis JH, Francis IR, Rubin JM. Hepatic hemodynamic alterations after administration of oral CT contrast agents. Radiology 1996; 199:713-6. [PMID: 8637993 DOI: 10.1148/radiology.199.3.8637993] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
PURPOSE To assess the effects of oral computed tomography (CT) contrast agents on hepatic hemodynamics with duplex Doppler ultrasound (US). MATERIALS AND METHODS Thirty healthy subjects who fasted underwent duplex Doppler US of the hepatic artery and portal vein both before and after administration of oral CT contrast agents. Resistive indexes were determined for the hepatic arteries. Peak and mean velocity (centimeters per second) and mean diameter were calculated for the main portal vein. RESULTS Statistically significant elevation of the resistive index (P < .01) of the hepatic arteries was observed after ingestion of oral CT contrast agents. Increase in the mean resistive index at 15 minutes was 12% in the proper hepatic arteries and 20% in the intrahepatic arteries. There was a postprandial increase in mean portal venous flow compared with baseline levels (1,110 mL/min +/- 210 vs 940 mL/min +/- 140) (P < .05). CONCLUSION An elevation of hepatic artery resistance that is probably due to arterial vasoconstriction after ingestion of oral CT contrast agents can be observed with Doppler US. Hemodynamic changes in liver vasculature after ingestion of oral CT contrast agents may have as yet unknown implications for CT scanning of the liver.
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Ellis JH, Burden MN, Vinogradov DV, Linge C, Crowe JS. Interactions of CD80 and CD86 with CD28 and CTLA4. THE JOURNAL OF IMMUNOLOGY 1996. [DOI: 10.4049/jimmunol.156.8.2700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
CD80 and CD86 are cell surface glycoproteins expressed on a variety of professional APCs. They have attracted much attention due to their function as potent costimulators of T lymphocyte function through their interaction with CD28 and possibly CTLA4. Because inhibitors of this interaction may have therapeutic relevance in human autoimmune disease, we investigated the properties of linear peptides derived from conserved regions of CTLA4 and CD80 known to be essential for binding. None of these peptides were sufficient to bind ligand, nor did they act as potent competitive inhibitors. Conformationally constrained versions of the CTLA4 motif were also inactive. These results suggested that other parts of the proteins are important in determining binding, so a series of modified CD80 and CD86 molecules were constructed in an attempt to identify other binding determinants. Insertion of two residues between the two Ig domains of CD80 resulted in decreased affinity for CTLA4, but a similar mutation in CD86 was without effect. We also identified another asymmetry between CD80 and CD86 in that the V domain of CD86 but not that of CD80 is sufficient for CTLA4 binding. The CD86-V domain appears to have CTLA4 binding properties equivalent to that of intact CD86. These data illustrate a fundamental difference between these costimulatory molecules and suggest a mechanism by which they may be differentially recognized by receptors on the T cell surface.
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Ellis JH, Burden MN, Vinogradov DV, Linge C, Crowe JS. Interactions of CD80 and CD86 with CD28 and CTLA4. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 1996; 156:2700-9. [PMID: 8609386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
CD80 and CD86 are cell surface glycoproteins expressed on a variety of professional APCs. They have attracted much attention due to their function as potent costimulators of T lymphocyte function through their interaction with CD28 and possibly CTLA4. Because inhibitors of this interaction may have therapeutic relevance in human autoimmune disease, we investigated the properties of linear peptides derived from conserved regions of CTLA4 and CD80 known to be essential for binding. None of these peptides were sufficient to bind ligand, nor did they act as potent competitive inhibitors. Conformationally constrained versions of the CTLA4 motif were also inactive. These results suggested that other parts of the proteins are important in determining binding, so a series of modified CD80 and CD86 molecules were constructed in an attempt to identify other binding determinants. Insertion of two residues between the two Ig domains of CD80 resulted in decreased affinity for CTLA4, but a similar mutation in CD86 was without effect. We also identified another asymmetry between CD80 and CD86 in that the V domain of CD86 but not that of CD80 is sufficient for CTLA4 binding. The CD86-V domain appears to have CTLA4 binding properties equivalent to that of intact CD86. These data illustrate a fundamental difference between these costimulatory molecules and suggest a mechanism by which they may be differentially recognized by receptors on the T cell surface.
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Bude RO, Platt JF, Wahl RL, Ellis JH, Rubin JM. Suspected obstructive pyelocaliectasis: Doppler ultrasonography compared with diuretic renal scintigraphy in proven cases. Can Assoc Radiol J 1996; 47:101-6. [PMID: 8612080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
OBJECTIVE To compare Doppler ultrasonography with diuretic renal scintigraphy in the differentiation of obstructive from nonobstructive pyelocaliectasis. PATIENTS AND METHOD The authors reviewed the findings of Doppler ultrasonography and diuretic renal scintigraphy performed over a 3-year period for 27 pyelocaliectatic kidneys (17 obstructed and 10 unobstructed) in 20 individuals ranging in age from 19 to 88 years. The kidneys were classified as "obstructed" or "unobstructed" on the basis of the resistive index as calculated from Doppler ultrasonographic results and as "obstructed", "unobstructed" or "indeterminate" on the basis of the clearance half-time determined from scintigraphic findings. RESULTS On the basis of scintigraphy, the obstruction status was indeterminate in 12 of the 27 kidneys. The data were analysed for sensitivity and specificity in two ways, first by classifying the kidneys with indeterminate obstruction status as "obstructed, " and then by excluding them from the analysis altogether. In both situations, the differences in sensitivity and specificity between Doppler ultrasonography and scintigraphy were not statistically significant (chi 2 test, p > 0.05). When the kidneys with indeterminate obstruction status were included in the obstructed category, the sensitivity and specificity of Doppler ultrasonography were 94% and 90% respectively and of scintigraphy 100% and 70% respectively; when the kidneys with indeterminate obstruction status were excluded, the sensitivity and specificity of Doppler ultrasonography were 83% and 89% respectively and of scintigraphy 100% and 78% respectively. CONCLUSIONS These results suggest that Doppler ultrasonography is comparable to diuretic renal scintigraphy in the work-up of potential obstructive pyelocaliectasis. Because grey-scale ultrasonography is usually performed before scintigraphy, a Doppler examination could be added at this stage, which might reduce the time necessary to establish the diagnosis.
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Strohbehn K, Ellis JH, Strohbehn JA, DeLancey JO. Magnetic resonance imaging of the levator ani with anatomic correlation. Obstet Gynecol 1996; 87:277-85. [PMID: 8559539 DOI: 10.1016/0029-7844(95)00410-6] [Citation(s) in RCA: 131] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
OBJECTIVE To define in women the anatomy of the levator ani muscle visible on magnetic resonance imaging (MRI) so these muscles can be studied in women with prolapse or incontinence. METHODS Multiplanar T1- and T2-weighted MRI was obtained of two female pelvic cadaver specimens, ages 25 and 33. One specimen was hemisected, with half sectioned in the axial plane and the other half in the coronal plane. The other specimen was sectioned in the coronal plane. Anatomic cross sections of these specimens were correlated with the cadaver MRI and MRI of living patients. One sagittal and two axial series of anatomic sections not imaged were also used for comparison. RESULTS Serial sagittal and axial MRI demonstrates the pubovisceralis ("pubococcygeus") muscle as it originates from the pubic bone, passes alongside the urethra, vagina, and rectum, and then dorsal to the anorectum. Its muscle bulk, attachment to the distal half of the vagina, and insertion between the internal and external anal sphincters can be seen on axial views. The origin of the iliococcygeus muscle at the arcus tendineus levator ani is seen in axial and coronal images. Coronal and sagittal images demonstrate the relative thickness and medial position of the pubovisceralis muscle compared with the thin, diaphragm-like lateral iliococcygeus muscle. CONCLUSION Magnetic resonance imaging of the cadaver pelvis demonstrates the detailed anatomy of the levator ani muscle. This is an important precursor to future research of the structure, bulk, and orientation of the levator ani in living women with prolapse.
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Platt JF, Ellis JH, Korobkin M, Reige KA, Konnak JW, Leichtman AB. Potential renal donors: comparison of conventional imaging with helical CT. Radiology 1996; 198:419-23. [PMID: 8596843 DOI: 10.1148/radiology.198.2.8596843] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
PURPOSE To assess helical computed tomography (CT) as a potential substitute for intravenous urography and renal angiography in the evaluation of living potential renal donors. MATERIALS AND METHODS Helical CT was performed in 32 potential donors both before and after administration of contrast material. Scans were reconstructed at 1.5-mm intervals for three-dimensional reconstructions. Helical CT images were blindly compared with urograms (n = 32) and renal angiograms (n = 24). RESULTS One small accessory artery was not depicted with helical CT, and angiography did not depict an accessory artery arising in proximity to the origin of the main renal artery. All eight kidneys with early dividing main arteries were identified with both helical CT and angiography. Three renal venous anomalies were depicted only with helical CT. Helical CT and urography equally depicted nonvascular findings. CONCLUSION Renal helical CT is a suitable replacement for intravenous urography and angiography in the assessment of living renal donors.
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