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PubMed1990

Enhancement by L-methionine on the contractile response of uterine segments to acetylcholine and high KCl is mainly due to enhancement of Ca uptake.

Acetylcholine (ACh)- and high KCl-stimulated 45Ca uptake into rat uterine segments was inhibited by 3-deazaadenosine (3-DAA) plus homocysteine thiolactone (HCTL), and this inhibitory effect was attenuated by L-methionine (L-Met). Ca-depleted Ringer solution in which uterine muscle had been incubated with L-Met did not enhance the contractile response of another uterine segment to ACh and high KCl in the presence of 3-DAA plus HCTL. These findings together with previous results suggest that the enhancing effect of L-Met on the contractile responses to ACh and high KCl is mainly due to an increase in Ca2+ uptake into the uterine muscle.

Acetylcholine↗

PubMed2002

Effects of enhanced external counterpulsation on Health-Related Quality of Life continue 12 months after treatment: a substudy of the Multicenter Study of Enhanced External Counterpulsation.

BACKGROUND: The Multicenter Study of Enhanced External Counterpulsation (MUST-EECP) was the first prospective, randomized, blinded, sham-controlled study of enhanced external counterpulsation (EECP) in the treatment of chronic stable angina. We previously reported that EECP therapy lengthens the time to exercise-induced myocardial ischemia and reduces angina. We now describe the effects of EECP therapy versus a sham-treated control group in terms of patients' functioning, their senses of well-being and other Health-Related Quality Of Life (HQOL) parameters from baseline to end of treatment and from baseline to 12 months after treatment. OBJECTIVE: To determine whether a 35-hour course of EECP affects the HQOL of patients with symptomatic coronary artery disease, 12 months following treatment. METHODS: Seventy-one of the 139 patients enrolled in MUST-EECP provided evaluable patient-completed questionnaires at baseline, at the end of treatment, and 12 months post-treatment. The Medical Outcomes Study 36-Item Short-Form Health Survey and the Quality of Life Index-Cardiac Version III were used to assess effects on HQOL. RESULTS: Both groups had similar HQOL scores at baseline. At end of treatment and at 12-month follow up, patients who had active-CP reported greater improvement than those who had inactive-CP in all nine quality of life scales, including ability to perform activities of daily living, ability to work, bodily pain, confidence in health, energy, ability to engage in social activities with family and friends, anxiety and depression, and quality of life issues from the effects of angina on health and functioning. Despite small sample sizes, active-CP patients demonstrated significantly greater improvement at 12 months following treatment in bodily pain, social functioning, and quality of life specific to cardiac patients compared with inactive-CP patients. CONCLUSION: Significant health-related quality of life improvements were measurable up to 12 months after the completion of treatment with EECP. Improvements in this controlled study are consistent with HQOL changes reported in case series and patient registries. Larger studies are warranted.

Aged↗

PubMed1999

Implementing a system of enhanced surveillance for measles in Victoria. The Enhanced Measles Surveillance Working Party.

In response to identified deficiencies in the passive surveillance system for measles in Victoria and the move towards local disease elimination and global disease eradication, a system of enhanced measles surveillance was introduced in 1997. Each case is contacted and a structured telephone questionnaire is completed, collecting information on symptomatology and encouraging serological confirmation, if not already performed. The introduction of a paediatric phlebotomy service to collect serum specimens in the case's home, has led to a dramatic increase in the proportion of cases where testing is performed, reaching nearly 90 per cent by the end of 1998. The median time from notification to specimen collection is one day. The Victorian approach to the enhanced surveillance of measles provides a framework for similar systems as Australia approaches disease elimination.

Child↗

PubMed1993

[MRI enhancement of the facial nerve with Gd-DTPA--first report--experimental study on the enhancement mechanism used in viewing vascular permeability of the facial nerve].

Although there have recently been numerous reports of enhanced MRI in patients with facial palsy, the mechanism of enhancement remains largely unknown. In the present study, animal models with experimentally induced facial paralysis were prepared, and the vascular permeabilities of normal and damaged facial nerves were assessed using Evans blue albumin (EBA) as a tracer. The Gd-DTPA contents in normal and compressively damaged facial nerves were also investigated. The following results were obtained: 1. In the normal intratemporal facial nerve, EBA remained in the vessels, and did not leak into the endoneurium. In contrast, vascular permeability was very high in the epineurium and the geniculate ganglion which showed leakage of large amounts of EBA from vessels. 2. At the site of compression in the damaged nerve, EBA leakage was also seen in the endoneurism, indicating accentuated vascular permeability. This accentuation of vascular permeability shifted toward the distal side. However, no EBA leakage was seen on the side proximal to the site of compression. 3. Significantly higher Gd-DTPA contents were obtained in the facial nerve on the paralytic side than in that on the normal side (p < 0.001). As for differences between the distal and proximal sides, the distal side had a significantly higher Gd-DTPA content (p < 0.01). Assessment of vascular permeability with EBA revealed accentuated vascular permeability on the side distal to the site of compression. These results showed the presence of a blood nerve barrier (BNB) in the facial nerve.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMedDate not supplied

Detection of brain metastases: comparison of contrast-enhanced MR with unenhanced MR and enhanced CT.

Contrast-enhanced MR studies were compared with noncontrast MR and contrast-enhanced CT scans in the evaluation of intraparenchymal brain metastases. Fifty consecutive inpatients were studied with short and long repetition time (TR) sequences before and after the administration of gadopentetate dimeglumine. In addition, a delayed short TR sequence was performed. The contrast CT, noncontrast MR, immediate postcontrast short TR sequence, postcontrast long TR sequence, and delayed postcontrast short TR sequence were each read blindly and independently by two neuroradiologists. These results were then compared with a final interpretation, reached by all the neuroradiologists in the study, using all the clinical information and imaging findings. Postcontrast short TR scans proved to be superior to other sequences. They were particularly useful in the detection of metastases in the posterior fossa and cortex. The delayed postcontrast short TR scan held no definite advantage over the immediate postcontrast short TR scan, although metastases were sometimes seen slightly better after the delay. While long TR sequences were not always sensitive or specific, they often did provide ancillary information and were particularly useful in cases of hemorrhagic metastases. Because of these findings, we recommend that the evaluation of intraparenchymal metastases consist of a single postcontrast long TR scan followed by a single postcontrast short TR scan. While these sequences should be very accurate in the detection of metastases, we also generally perform a single precontrast short TR scan as well, since the question of hemorrhage or bone lesion may be clinically relevant.

Adolescent↗

PubMed1974

Immunologic enhancement of rat renal allografts. I. Comparative morphology of acutely rejecting and passively enhanced grafts.

The acute unmodified rejection of (Lewis x Brown Norway) F(1) to Lewis renal allografts is characterized by an early and progressive lymphoid cell infiltrate, glomerular necrosis, necrotizing arteritis and ischemic cortical necrosis leading to graft destruction. A single low dose of enhancing antiserum given at the time of transplantation prolongs graft survival by abrogating the necrotizing lesions in glomeruli and arteries and the subsequent cortical necrosis. Passive enhancement in this model is interpreted as representing predominantly a block in the humoral antibody-mediated rejection response. It is suggested that the block is effected mainly, peripherally, ie, at the level of the transplanted kidney itself.

Animals↗

PubMedDate not supplied

Renal cancer staging: comparison of contrast-enhanced CT and gadolinium-enhanced fat-suppressed spin-echo and gradient-echo MR imaging.

Fifty-three consecutive patients with 61 solid or complex non-fat-containing renal masses compatible with renal cancer were examined with contrast-enhanced computed tomography (CT) and magnetic resonance (MR) imaging with pre- and postcontrast FLASH (fast low-angle shot) and fat-suppressed spin-echo sequences. CT and MR imaging were performed within a 1-month interval. CT and MR images were prospectively interpreted. Tumor detection and staging were determined in all patients. CT and MR imaging enabled detection of 54 and 58 of 61 renal tumors, respectively. CT and MR imaging showed 34 and 35 of 38 histologically proved renal tumors, respectively, in 31 patients. Tumor size on CT and MR images demonstrated good correlation and correlated well with the size of pathologic specimens of 34 of 38 resected tumors detected with CT and MR imaging (r = .99). Of the 31 tumors in 31 patients who underwent surgical resection, 24 were correctly staged with CT and 29 with MR imaging. CT and MR imaging both enabled correct staging of four of five additional tumors with biopsy proof of tumor stage. A moderate difference in staging was observed between CT and MR imaging (P = .05). CT showed 13 and MR imaging 15 of 15 tumor thrombi. CT and MR imaging both showed 11 of 11 cases of adenopathy. The results suggest that MR imaging is moderately better than CT for the detection and staging of renal cancer.

Carcinoma, Renal Cell↗

PubMed1994

Cloning of Rous sarcoma virus enhancer factor genes. I. Evidence that RSV-EF-I is related to Y-box (inverted CCAAT) binding proteins and binds to multiple motifs in the RSV enhancer.

A cDNA clone was isolated from a chicken embryo cDNA library employing a PCR-generated radiolabeled probe specific for the U3 region of the Rous sarcoma virus LTR. The cDNA encodes a protein of 345 aa and is homologous to the Y-box (inverted CCAAT) binding proteins. The amino acid sequence of the RSV-EF-I shows 75% identity with rat EF1 but the NH2-terminal 60-aa residues share little homology. At the carboxyl terminus an additional 28-aa sequence, rich in basic residues, probably encoded by an extra exon, is present in the chicken RSV-EF-1. Electrophoretic mobility assays carried out with various radiolabeled oligonucleotides spanning the U3 region of the RSV LTR (-234 to -54) indicated that the RSV-EF-I binds strongly to the sequence AAGGTGGTAC and somewhat less efficiently to the sequences AAGGAAAG and CTTATGCAA. In contrast to rat EF1A which binds to the inverted CCAAT box, RSV-EF-I does not bind to the CCAAT box sequence. These results suggest that the RSV-EF-I, although structurally similar to the rat EF1A, binds differently to more than one cis-acting element. The gene for RSV-EF-I is expressed in a variety of cell lines, although most abundantly in avian fibroblasts compared to mammalian cells. It is barely expressed in normal lives but expressed at significantly enhanced levels in many immortalized hepatocytes and hepatic tumors.

Amino Acid Sequence↗

PubMed2005

Gadolinium-enhanced versus time-of-flight magnetic resonance angiography: what is the benefit of contrast enhancement in evaluating carotid stenosis?

Accurate patient selection based on preoperative imaging is imperative to good risk reduction in patients undergoing carotid endarterectomy (CEA). The goal of this study was to assess the accuracy of gadolinium-enhanced magnetic resonance angiography (GE MRA) versus time-of-flight (TOF) MRA in the work-up of patients undergoing CEA. Patients undergoing CEA between 1999 and 2001 were identified from a prospectively maintained institutional database. GE or TOF MRA was obtained on extracranial carotid arteries (n = 319) in patients undergoing CEA. Stenosis on MRA images was graded as moderate (n = 76) or severe (n = 243) by an attending radiologist who was blind to duplex results. Duplex imaging was performed in an Intersocietal Commission for the Accreditation of Vascular Labs (ICAVL) accredited lab, and stenosis was stratified as moderate (50-79%, n = 76) or high (80-99%, n = 243) grade using University of Washington criteria. For each patient, the degree of stenosis as determined by MRA (GE versus TOF) was compared to percent stenosis on duplex. For moderate-grade lesions, GE MRA concurred with duplex in 11.1% (4/36), underestimated in 2.8% (1/36), and overestimated in 86.1% (31/36) of carotid arteries imaged. TOF MRA concurred with duplex in 35% (14/40), underestimated in 0% (0/40), and overestimated in 65% (26/40) of carotid arteries. High-grade lesions demonstrated improved concordance between MRA and duplex. For these lesions, GE MRA concurred with duplex in 95.6% (130/136) of carotid arteries imaged, never overestimated stenosis (0/136), and underestimated in 4.4% (6/136). TOF MRA concurred with duplex 96.3% (103/107), overestimated stenosis as an occlusion in 0.9% (1/107), and underestimated in 2.8% (3/107). In addition to neck visualization, the GE technique allowed simultaneous aortic arch imaging. This was accomplished in 79.1% (136/172) of all GE MRAs. Simultaneous aortic arch imaging was not technically feasible with TOF MRA. For moderate-grade lesions, both MR techniques are inaccurate predictors of degree of carotid stenosis and result in a significant overestimation of stenosis. Each technique demonstrates improved concordance with duplex ultrasound in the setting of severe carotid artery stenoses. The ability of GE MRA to simultaneously image the aortic arch and the neck may allow for detection of occult tandem lesions and other anatomic variations, which may be particularly important in preoperative planning for carotid artery stenting.

Carotid Stenosis↗

PubMed2005

Cardiac sarcoidosis evaluated with gadolinium-enhanced magnetic resonance and contrast-enhanced 64-slice computed tomography.

Sarcoidosis is a multi-system granulomatous disorder of unknown etiology with symptomatic cardiac involvement in up to 7% of patients. The clinical features of sarcoid heart disease include congestive heart failure, arrhythmias, conduction disturbances, and sudden death. We evaluated the value of contrast-enhanced multi-detector computed tomography in delineating myocardial scar and granulomatous inflammation by comparing our findings with gadolinium magnetic resonance in a patient diagnosed with cardiac sarcoidosis.

Adult↗

PubMed2003

Diagnostic value of routine clinical parameters in acute myocardial infarction: a comparison to delayed contrast enhanced magnetic resonance imaging. Delayed enhancement and routine clinical parameters after myocardial infarction.

AIMS: Contrast enhanced magnetic resonance imaging (ceMRI) has been shown to reliably identify irreversible myocardial injury. The aim of this study was to compare the findings on ceMRI with routine clinical markers of myocardial injury in patients with acute myocardial infarction (MI). METHODS AND RESULTS: Twenty-four patients with acute MI were investigated at 1.5 T. The global myocardial function was analysed with a standard cine MR protocol and a stack of short axis slices encompassing the entire left ventricle. Corresponding short axis slices were acquired for delayed ceMRI 15-20 min after the administration of 0.2 mmol gadolinium-DTPA/kg body weight. Mass of hyperenhancement and peak creatine kinase release (peak CK) was determined for each patient. The presenting 12-lead ECG was analysed for ST-elevation on admission and later development of Q-waves. Mass of hyperenhancement correlated moderately well to peak CK (r = 0.65, p < 0.01) and endsystolic volume index (r = 0.55, p < 0.01). Mass of hyperenhancement was inversely correlated to ejection fraction (r = -0.50, p = 0.02). Neither the presence of ST elevation on the admission ECG nor the later development of Q-waves did relate to the transmural extent of hyperenhancement and to the mass of hyperenhancement. CONCLUSION: Mass of hyperenhancement significantly correlates to global myocardial function and to peak CK. However, there is no relationship between the findings in ceMRI and 12-lead ECG abnormalities on admission suggesting an advantage of ceMRI in defining transmural extent and depicting small areas of necrosis.

Adult↗

PubMed2006

Casein kinase 2 (CK2) increases survivin expression via enhanced beta-catenin-T cell factor/lymphoid enhancer binding factor-dependent transcription.

Increased expression of casein kinase 2 (CK2) is associated with hyperproliferation and suppression of apoptosis in cancer. Mutations in the tumor suppressor APC (adenomatous polyposis coli) are frequent in colon cancer and often augment beta-catenin-T cell factor (Tcf)/lymphoid enhancer binding factor (Lef)-dependent transcription of genes such as c-myc and cyclin-D1. CK2 has also been implicated recently in the regulation of beta-catenin stability. To identify mechanisms by which CK2 promotes survival, effects of the specific CK2 inhibitors 4,5,6,7-tetrabromobenzotriazole (TBB) and 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole were assessed. TBB and 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole significantly decreased proliferation and increased apoptosis of HT29(US) colon cancer cells. RT-PCR and immunoblot analysis revealed that both inhibitors decreased survivin mRNA and protein levels in HT29(US) cells. Similar effects were observed with TBB in human DLD-1 and SW-480 colorectal cells as well as ZR-75 breast cancer cells and HEK-293T embryonic kidney cells. Expression of GFP-CK2alpha in HEK-293T cells resulted in beta-catenin-Tcf/Lef-dependent up-regulation of survivin and increased resistance to anticancer drugs. Augmented beta-catenin-Tcf/Lef-dependent transcription and resistance to apoptosis observed upon GFP-CK2alpha expression were abolished by TBB. Alternatively, HEK-293T cells expressing GFP-survivin were resistant to TBB-induced apoptosis. Finally, siRNA-mediated down-regulation of CK2alpha in HEK-293T cells coincided with reduced beta-catenin and survivin levels. Taken together, these results suggest that CK2 kinase activity promotes survival by increasing survivin expression via beta-catenin-Tcf/Lef-mediated transcription. Hence, selective CK2 inhibition or down-regulation in tumors may provide an attractive opportunity for the development of novel cancer therapies.

Casein Kinase II↗

PubMed2000

Chromatin assembly enhances binding to the CYP2B1 phenobarbital-responsive unit (PBRU) of nuclear factor-1, which binds simultaneously with constitutive androstane receptor (CAR)/retinoid X receptor (RXR) and enhances CAR/RXR-mediated activation of the PBRU.

Phenobarbital induction of CYP2B genes is mediated by a complex phenobarbital-responsive enhancer (PBRU), which contains a binding site for nuclear factor-1 (NF-1) flanked by two DR-4 nuclear receptor (NR) binding sites for a heterodimer of constitutive androstane receptor (CAR) and retinoid X receptor (RXR). To examine potential interactions between NF-1 and CAR/RXR, binding of purified recombinant proteins to DNA, or to chromatin assembled using Drosophila embryo extract, was examined. NF-1 and CAR/RXR bound simultaneously and independently to the overlapping NF-1 and NR-1 sites; binding of CAR/RXR to the NR-2 site was modestly increased by NF-1 binding; and CAR/RXR bound to a new site in the PBRU region, designated NR-3. Assembly of plasmid DNA into chromatin using Drosophila extract resulted in linearly phased nucleosomes in the PBRU region. The apparent binding affinity of NF-1 was increased by about 10-fold in assembled chromatin compared with DNA, whereas CAR/RXR binding was decreased. As observed for DNA, however, simultaneous, largely independent, binding to the NF-1 and NR sites was observed. CAR-mediated transactivation of the PBRU in cultured cells of hepatic origin was inhibited by mutations in the NF-1 site, and overexpression of NF-1 increased CAR transactivation in HepG2 cells. These studies demonstrate that NF-1 and CAR/RXR can both bind to the PBRU at the same time and that chromatin assembly increases NF-1 binding, which is consistent with previous in vivo footprinting studies in which the NF-1 site was occupied in untreated animals and the NF-1 and flanking NR sites were occupied after phenobarbital treatment. CAR-mediated trans-activation of the PBRU was increased by NF-1, analogous to NF-1 effects on phenobarbital induction in previous transient transfection studies and consistent with mediation of phenobarbital induction by CAR.

Amino Acid Motifs↗

PubMed1975

An extravascular component of contrast enhancement in cranial computed tomography. Part I. The tissue-blood ratio of contrast enhancement.

One can calculate the tissue-blood ratio of enhancement by analyzing the quantitative aspects of the CT scans of the cranium and blood samples both before and after the injection of contrast medium. This ratio is equivalent to that between the iodine content of a given volume of tissue and an equal volume of blood. Analysis of 47 normal patients, including 27 with pathological brain lesions, indicated that there is significant extravasation of contrast medium in patients with such lesions.

Brain↗

PubMed2025

H3K4me2 marks the enhancer: Enhancer logic in the zebrafish embryo.

At a key point in development, the embryo activates its genome: a shift that is largely coordinated by maternally derived factors. A new study in PLOS Biology identifies H3K4me2-marked enhancers in zebrafish that function independently and mirror the gamete state.

Animals↗

PubMed2004

To enhance or not to enhance? 18F-FDG and CT contrast agents in dual-modality 18F-FDG PET/CT.

UNLABELLED: In combined PET/CT imaging, functional data provided by 18F-FDG increase diagnostic accuracy over conventional PET and CT in a variety of malignancies. The question to be raised is: how much is CT needed in PET/CT imaging? DISCUSSION: In stand-alone CT imaging, contrast agents are applied to aid differentiation of anatomic structures, improve lesion localization, and support lesion characterization. Based on our experience, the most important benefit when applying CT contrast agents in PET/CT imaging relates to more precise anatomic localization of pathology by differentiation of the lesion from its surrounding structures on CT. This benefit must be considered most profound in the head and neck as well as the abdomen and pelvis, where delineation of pathology from muscles, vascular structures, or the intestine is critical. CT contrast agents can be of additional value in tumors with only mild or no increase in 18F-FDG uptake by supporting lesion detection and characterization. The complementary role of CT contrast agents and molecular contrast for PET/CT imaging is addressed in this review. The authors provide specific indications as to which contrast-enhanced CT data provide additional diagnostic value. CONCLUSION: Functional contrast aids lesion detection and characterization, whereas morphologic contrast improves lesion localization. CT contrast agents and PET tracers do not compete but rather are complementary in combined PET/CT imaging.

Contrast Media↗

PubMed2004

Evaluation of enhancement patterns of focal nodular hyperplasia in contrast-enhanced, wide-band phase-inversion harmonic power Doppler imaging of the liver.

BACKGROUND: The purpose of the study was to assess the quality of performance of wideband, phase inversion harmonic power Doppler sonography in the diagnosis of focal nodular. MATERIAL/METHODS: During a period of one year, thirty-one patients with FNH previously confirmed by ultrasound-guided biopsy, surgical resection, dynamic helical computed tomography or magnetic resonance imaging were examined. The study protocol consisted of B-mode gray scale sonography, color Doppler, power Doppler examinations, and helical CT scans. Then PI scans were performed after the injection of 2.5 g of Levovist intravenously. RESULTS: The images obtained by the B-mode gray scale were typical for focal nodular hyperplasia in 13 lesions only (32.5%), and obtained by color, power Doppler sonography in 25 lesions (62%). On the contrary all patients with focal nodular hyperplasia were diagnosed based on the wide-band, phase inversion power Doppler sonography findings. The common enhancement pattern at pulseinversion harmonic US was filling in a central tumor artery with further centrifugal development of contrast. Then during early arterial phase, all typical anatomical features of FNH as 'star sign 'or 'spoke-wheel 'pattern were clearly visible .In 3 cases ,computed tomography and magnetic resonance imaging have failed to disclose pathology while phase inversion sonographic images were completely suggestive which was later confirmed by histologic examination. CONCLUSIONS: Our data demonstrates the usefulness of wide-band, phase inversion harmonic power Doppler sonography in the differential diagnosis of hepatic focal nodular hyperplasia by visualizing all characteristic anatomical details.

Adult↗

PubMedDate not supplied

CT: to enhance or not to enhance: A computer-aided study.

Statistical analysis was performed of the carefully coded results of computed tomographic scans, with and without contrast medium, of a substantial group of patients with proved diagnoses. Bayesian methods were used to provide computer-aided diagnoses with considerable success. Further analysis of these results suggested that expert advice can be provided by the computer concerning which patients would benefit diagnostically from enhancement after their plain scan description has been fed into the computer.

Brain Diseases↗