Characterization of a phage specific to hemorrhagic Escherichia coli O157:H7 and disclosure of variations in host outer membrane protein ompC.
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Amino Acid Sequence↗
Biomedical subjects
Y Chang
Publications and source records attributed to Y Chang.
Anomalous origin of one pulmonary artery from the innominate artery: a report of two cases.
Two children with an anomalous origin of one pulmonary artery from the innominate artery are reported. One was a 15-month-old boy presenting with respiratory distress. He had a right aortic arch and his left pulmonary artery originated from the innominate artery. The other was a 1-month-old girl presenting with congestive heart failure. She had a left aortic arch and her right pulmonary artery originated from the innominate artery. An understanding of the embryological pathogenesis of these anomalies has significant therapeutic implications.
Brachiocephalic Trunk↗
Ultrasonography by emergency physicians in patients with suspected ureteral colic.
We performed a prospective study of patients with suspected ureteral colic to evaluate the test characteristics of bedside renal ultrasonography (US) performed by emergency physicians (EPs) for detecting hydronephrosis, and to evaluate how US can be used to predict the likelihood of nephrolithiasis. Thirteen EPs performed US, recorded the presence of hydronephrosis, and made an assessment of the likelihood of nephrolithiasis. All patients underwent i.v. pyelography (IVP) or unenhanced helical computed tomography (CT). There were 126 patients in the study: 84 underwent IVP; 42 underwent helical CT. Test characteristics of bedside US for detecting hydronephrosis were: sensitivity 72%, specificity 73%, positive predictive value (PPV) 85%, negative predictive value (NPV) 54%, accuracy 72%. The PPV and NPV for the ability of the EP to predict nephrolithiasis after performing US were 86% and 75%, respectively. We conclude that bedside US performed by EPs may be used to detect hydronephrosis and help predict the presence of nephrolithiasis.
Adult↗
Serum lipids and arterial plaque load are altered independently with high-dose progesterone in hypercholesterolemic male rabbits.
Antiatherogenic effects of sex steroids in premenopausal women are not well defined. Therefore, we employed an established rabbit model for atherosclerosis to study the effects of exogenous estrogen and a progesterone analogue (P) on serum lipids and aortic plaque load. Serum cholesterol (C) and triglyceride (T) levels and atherosclerotic plaque loads were compared in 5 groups of male New Zealand White rabbits fed a 12-week, C-rich diet: 1 control group (CG) and 4 groups treated with estriol (E), haloperidol (H), low-dose 17-hydroxyprogesterone (LDP), or high-dose 17-hydroxyprogesterone (HDP). Serum P was measured in the LDP and HDP groups. Serial histologic sections (15 each of 27 ascending aortas) were studied by light microscopy and computerized morphometric analysis. Plaque load is defined as the ratio of intimal area to medial area (I/M). Exogenous E (p<0.001), H (P = 0. 02), LDP and HDP (P<0.001, each) were found to be significantly associated with less aortic plaque load than controls. In a multivariate analysis, after controlling for the differences in serum C and T levels, HDP (p = 0.014) was found to be associated with less aortic plaque load than controls, and this association approached statistical significance in the E (p = 0.052) and H (p = 0.069) groups. These data suggest that the mechanism(s) involved with the antiatherogenic effect of HDP in this animal model is, or are, independent of an alteration in serum lipids.
17-alpha-Hydroxyprogesterone↗
Lipid modulation in insulin-dependent diabetes mellitus: effect on microvascular outcomes.
Although hyperlipidemia is associated with the development of diabetes complications, the effect of lipid reduction on microvascular complications is unknown. We initiated a 2-year, randomized, double-blinded placebo-controlled pilot trial of simvastatin/diet vs. diet alone in Type 1 diabetic patients without overt nephropathy. Thirty-nine patients with LDL cholesterol 100-160 mg/dl, >10 year duration of diabetes and an albumin excretion rate (AER) <200 microg/min were recruited for study. The primary end-point was change in AER. Secondary end-points were change in ankle-brachial index, progression of retinopathy status, change in vibratory threshold, and development of new clinical neuropathy. Nineteen patients were treated with simvastatin and twenty with placebo. However, because of the lowering of drug initiation levels by the American Diabetes Association, the trial was terminated early with 2 subjects reaching 2 years, 17 reaching 18 months, 36 reaching 1 year, and all 6 months. Simvastatin significantly reduced total cholesterol (mean on treatment 173.4 vs. 191.4, P=.020) and LDL cholesterol (mean on treatment 105.0 vs. 127.7, P<.001). Simvastatin therapy was associated with a slower rise in AER compared to placebo, though the result was not statistically significant (median rate of change/month 0.004 vs. 0.029). There was a trend towards slower progression of neuropathy as measured by vibratory threshold (median change at 1 year 0.03 simvastatin vs. 0.94, P=.07). There was no difference in change in ankle-brachial index, clinical neuropathy status, or retinopathy status. In conclusion, treatment with simvastatin may have a beneficial effect on early nephropathy and diabetic neuropathy, justifying a fully powered trial. However, this would be difficult under current treatment guidelines.
Adult↗
MR findings in neonatal herpes simplex encephalitis type II.
The CT findings in neonatal herpes simplex encephalitis (HSE) type II have been previously described, whereas magnetic resonance (MR) findings as yet have not. Early CT findings can be subtle and difficult to detect. However, as the abnormalities evolve, most notably the strikingly increased density of cortical gray matter, they appear highly characteristic of neonatal HSE type II. This case report with neuropathologic verification describes serial MR and CT findings in HSE type II that suggest an etiology of the increased density characteristically seen on CT scans; it does not appear to be hemorrhage or calcification.
Cerebral Hemorrhage↗
Contrast-enhanced magnetic resonance angiography: dose the test dose bolus represent the main dose bolus accurately?
OBJECTIVE: To determine whether the time-intensity curves acquired by test and main dose contrast injections for MR angiography are similar. MATERIALS AND METHODS: In 11 patients, repeated contrast-enhanced 2D-turbo-FLASH scans with 1-sec interval were obtained. Both test and main dose time intensity curves were acquired from the abdominal aorta, and the parameters of time-intensity curves for the test and main boluses were compared. The parameters used were arterial and venous enhancement times, arterial peak enhancement time, arteriovenous circulation time, enhancement duration and enhancement expansion ratio. RESULTS: Between the main and test boluses, arterial and venous enhancement times and arteriovenous circulation time showed statistically significant correlation (p < 0.01), with correlation coefficients of 0.95, 0.92 and 0.98 respectively. Although the enhancement duration was definitely greater than infusion time, reasonable measurement of the end enhancement point in the main bolus was impossible. CONCLUSION: Only arterial and venous enhancement times and arteriovenous circulation time of the main bolus could be predicted from the test-bolus results. The use of these reliable parameters would lead to improvements in the scan timing method for MR angiography.
Adult↗
The optimization of scan timing for contrast-enhanced magnetic resonance angiography.
OBJECTIVE: To determine the optimal scan timing for contrast-enhanced magnetic resonance angiography and to evaluate a new timing method based on the arteriovenous circulation time. MATERIALS AND METHODS: Eighty-nine contrast-enhanced magnetic resonance angiographic examinations were performed mainly in the extremities. A 1.5T scanner with a 3-D turbo-FLASH sequence was used, and during each study, two consecutive arterial phases and one venous phase were acquired. Scan delay time was calculated from the time-intensity curve by the traditional (n = 48) and/or the new (n = 41) method. This latter was based on arteriovenous circulation time rather than peak arterial enhancement time, as used in the traditional method. The numbers of first-phase images showing a properly enhanced arterial phase were compared between the two methods. RESULTS: Mean scan delay time was 5.4 sec longer with the new method than with the traditional. Properly enhanced first-phase images were found in 65% of cases (31/48) using the traditional timing method, and 95% (39/41) using the new method. When cases in which there was mismatch between the target vessel and the time-intensity curve acquisition site are excluded, erroneous acquisition occurred in seven cases with the traditional method, but in none with the new method. CONCLUSION: The calculation of scan delay time on the basis of arteriovenous circulation time provides better timing for arterial phase acquisition than the traditional method.
Contrast Media↗
Cold acclimation improves recovery of cryopreserved grass (Zoysia and Lolium sp.).
Cold acclimation of Lolium L. and Zoysia Willd. Grass cultivars significantly increased regrowth of cryopreserved meristems. One wk of cold acclimation improved recovery following cryopreservation but extended acclimation (4-8 wk) resulted in the best regrowth. Cold acclimation also significantly increased the dehydration tolerance of both Zoysia and Lolium meristems. Lolium apices cold acclimated for 4 wk produced 60-100% regrowth following cryopreservation by slow freezing or encapsulation-dehydration. Cold-acclimated Zoysia had greater than 60% regrowth following encapsulation-dehydration when beads were dehydrated to less than 22% water content. Non-acclimated meristems of both genera had little or no regrowth. Thawed meristems grew quickly without callus formation and the plantlets produced were transplanted to pots in the greenhouse after 4 to 6 wk. Samples of each cultivar were stored in liquid nitrogen as part of the U.S. National Plant Germplasm System.
Journal Article↗
Cranial hypertrophic interstitial neuropathy.
The authors describe a patient with complex cranial neuropathy caused by pathologically proved hypertrophic interstitial neuropathy. Plain and contrast-enhanced MR studies were performed prior to surgical exploration. Surgical complications caused the patient's death and a complete pathology study was done. Though nonspecific, MR proved helpful in determining the extent of disease and areas of anatomic involvement.
Cranial Nerve Diseases↗
Intraventricular and subarachnoid hemorrhage resulting from necrotizing vasculitis of the choroid plexus in a patient with Churg-Strauss syndrome.
Neurologic symptoms are common in patients with the Churg-Strauss syndrome and often manifest as a peripheral neuropathy of the mononeuritis multiplex type secondary to vasculitis. Reports of central nervous system involvement is less frequent and ranges from psychiatric disturbances to cerebral hemorrhage. We report the first case of pathologically documented vasculitis involving the choroid plexus causing massive and fatal intraventricular and subarachnoid hemorrhages in a 47-year-old patient with Churg-Strauss syndrome.
Brain Edema↗
Primary low-grade B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) arising in dura.
We report 2 cases of low-grade B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) type presenting as primary lesions in the intracranial dura. Both patients are female, and, prior to biopsy were felt to have subdural hematoma and meningioma based on preoperative MRI scans. Histologically, both cases showed a diffuse proliferation of small centrocyte-like cells or monocytoid B cells admixed with a moderate number of large transformed cells. Reactive germinal center formation was present, as was plasmacytoid differentiation in one case. These histologic features are identical to those associated with low-grade MALT lymphomas arising at other more typical sites. Clinically, both patients were found to have stage IE disease at diagnosis without evidence of lymphoma outside of the central nervous system. Immunophenotypically, the lymphomas expressed B-cell-associated antigens CD20 and CD79a without coexpression of CD5, CD10, or CD23, and 1 of the 2 cases tested showed monoclonal rearrangement of the immunoglobulin heavy chain gene without rearrangement of bcl-1 or bcl-2. MALT lymphomas have recently been described in the dura and are postulated to arise in association with meningoepithelial cells. It is important that this entity be recognized and distinguished from other small B-cell non-Hodgkin's lymphomas such as mantle cell lymphoma, small lymphocytic lymphoma, or follicular small cleaved cell lymphomas, since localized low grade MALT lymphomas are usually clinically indolent proliferations which may require only minimally aggressive therapy.
Adult↗