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Clofibric acid increases the undirectional chiral inversion of ibuprofen in rat liver preparations.

1. The formation of (S)-ibuprofen from (R)-ibuprofen was monitored in perfused rat livers and in rat hepatocytes and the rate constants calculated. 2. Pre-treatment of animals for three days with clofibric acid markedly increased the (R)-to-(S) inversion of ibuprofen in both preparations. In contrast, clofibric acid did not elicit such a reaction with flurbiprofen, an analogue that does not undergo inversion under control conditions. 3. An increase in the chiral inversion was also seen when clofibric acid was added to the perfusion medium or to hepatocyte suspensions. In the latter system this increase was shown to be concentration dependent. 4. Pre-treatment of rat combined with addition of clofibric acid to the perfusion medium produced a cumulative stimulation of (R)-to-(S) inversion of ibuprofen. 5. Clofibric acid added to hepatocyte suspensions transiently increased intracellular concentrations of coenzyme A whereas (R)-ibuprofen transiently decreased CoA concentrations. The two effects cancelled each other upon co-incubation of the two compounds. 6. It is postulated that the metabolic interaction observed between clofibric acid and (R)-ibuprofen may be due to changes in intracellular concentrations of CoA.

Animals↗

An inverse relationship between serum vitamin C and blood pressure in a Japanese community.

To examine the relationship between serum vitamin C concentration and blood pressure level, a cross-sectional study was conducted. The subjects were 919 men and 1,266 women aged 40 years and over in a Japanese provincial city, Shibata, Niigata Prefecture. The mean and standard deviation of systolic blood pressure (SBP) were 134.0 +/- 20.0 mmHg for men and 128.3 +/- 20.8 mmHg for women, and those of diastolic blood pressure (DBP) were 81.0 +/- 11.7 mmHg and 75.8 +/- 11.4 mmHg, respectively. The mean and standard deviation of serum vitamin C were 42.5 +/- 18.6 mumol/L for men and 56.8 +/- 16.5 mumol/L for women. SBP and DBP were both inversely correlated with serum vitamin C concentration. The means of SBP or DBP were calculated for quartiles of serum vitamin C, and the significant inverse relationship was observed in any sex and age group. The inverse association persisted after adjustment for possible confounders: body mass index, serum total cholesterol, alcohol consumption, smoking, physical activity, antihypertensive medication, and dietary intake of salt, calcium, and potassium. Serum vitamin C appeared to be inversely related with both SBP and DBP in this Japanese population, although further intervention and experimental studies were required to establish the cause-effect relationship.

Adult↗

The inverse fallacy: an account of deviations from Bayes's theorem and the additivity principle.

In judging posterior probabilities, people often answer with the inverse conditional probability--a tendency named the inverse fallacy. Participants (N = 45) were given a series of probability problems that entailed estimating both p(H / D) and p(approximately H / D). The findings revealed that deviations of participants' estimates from Bayesian calculations and from the additivity principle could be predicted by the corresponding deviations of the inverse probabilities from these relevant normative benchmarks. Methodological and theoretical implications of the distinction between inverse fallacy and base-rate neglect and the generalization of the study of additivity to conditional probabilities are discussed.

Bayes Theorem↗

[Evaluation of t(1)-weighted black blood imaging using triple inversion recovery].

The black blood sequence, in which the blood signal is suppressed, fundamentally provides T(2)-weighted images. We developed a T(1)-weighted black blood sequence. This new sequence improved the triple IR sequence that uses three inversion pulses by continuously providing three inversion pulses. By so doing, the sequence lengthens the time from the third inversion pulse to data sampling. The new sequence sets the flip angle of the third inversion pulse to 95-110 degrees. Consequently, the difference in T(1) is emphasized in favor of the longitudinal magnetization component with the null point of blood. Data sampling uses the fast spin-echo sequence of a wide sampling bandwidth. The wide bandwidth shortens echo space. T(1)-weighted black blood images were obtained by these methods. Fat suppression is possible by using a CHESS pulse before data sampling.

Brain↗

Ultrasonographic evaluation of the gallbladder: comparison of fundamental, tissue harmonic, and pulse inversion harmonic imaging.

The purpose of our study was to compare pulse inversion harmonic imaging, tissue harmonic imaging, and fundamental imaging in the evaluation of normal and diseased gallbladder. Gallbladders in 170 patients were examined with fundamental imaging, tissue harmonic imaging, and pulse inversion harmonic imaging using a 2- to 5-MHz curved array transducer. Images were divided into normal and abnormal groups. The sharpness of the wall and degree of internal artifact were evaluated in normal groups, and lesion conspicuity and internal artifact were evaluated in abnormal groups. In images of both normal and abnormal gallbladder, significant differences were demonstrated among the 3 imaging methods (P < .001), and pulse inversion harmonic imaging provided the best image quality and the least artifact. Tissue harmonic imaging was the next best, providing better image quality and less artifact than fundamental imaging. In conclusion, pulse inversion harmonic imaging provided the best image quality and the least artifact among the 3 ultrasonographic methods in the evaluation of both normal and abnormal gallbladder.

Aged↗

Inversion mode: a new volume analysis tool for 3-dimensional ultrasonography.

OBJECTIVES: The main goal was to introduce the inversion mode as a new image analysis tool for the examination of fluid-filled structures using 3-dimensional ultrasonography during pregnancy. METHODS: Three-dimensional ultrasonography was performed on fetuses having fluid collections of noncardiac origin. Threshold adjustment was used to visually assign full transparency to voxels that were associated with fluid. A new postprocessing tool, called the inversion mode, was activated to transform this region of interest into opaque voxels. The morphologic appearance of fluid collections and their anatomic relationship to other organs were shown in this manner. RESULTS: Diagnostic features were shown by this technique in several fetuses with problems that included pleural effusion, duodenal atresia, urinary tract abnormalities, and hydrocephaly. Furthermore, the inversion mode also permitted surface reconstruction of an irregular pleural effusion that had close resemblance to results with the Virtual Organ Computer-Aided Analysis rotational slice technique. Acoustic shadowing was also documented as a potential technical limitation of this method. CONCLUSIONS: The inversion mode can display scattered or contiguous fluid-filled structures in ways that can be very difficult or impossible to accurately characterize with conventional ultrasonography. It may be particularly helpful for the evaluation of multiple fluid-filled cysts or irregular fluid collections in the fetus.

Female↗

[Use of fluid-attenuated inversion recovery (FLAIR) images in brain check-up].

Fluid-attenuated inversion recovery (FLAIR) images are magnetic resonance (MR) images obtained with an inversion recovery sequence having a long inversion time (T 1) and a long echo time (TE). The purpose of this study was to evaluate the utility of FLAIR images in brain check-up. 320 healthy adults (229 males, 91 females) were examined with FLAIR sequences of several types having repetitive time (TR) of 7000 msec, inversion times of 1700 msec and echo times (TE) of 110 msec. All studies were performed on a SHIMAZU MAGNEX 100 HP 1.0 T imaging system. FLAIR images were useful in detecting cortical and subcortical lesions near the brain surface, which were unclear in the conventional T 2 weighted images. FLAIR images were useful in evaluation of periventricular hyperintensity area (PVH). Frequency and degree of PVH were increased in aging. FLAIR images were useful in the differential diagnosis of lacuna and perivascular space. In conclusion, FLAIR images were very sensitive for the detection of brain lesions in brain check-up.

Adult↗

Plasma xanthophyll carotenoids correlate inversely with indices of oxidative DNA damage and lipid peroxidation.

Post hoc analysis of data obtained from a study designed to modulate oxidative damage by dietary intervention revealed consistently strong inverse correlations between plasma xanthophyll carotenoids and oxidative damage indices. Thirty-seven women participated in a 14-day dietary intervention that increased mean vegetable and fruit (VF) consumption to approximately 12 servings/day. An additional 10 subjects participated in an intervention that limited VF consumption to less than four servings per day. 8-Hydroxy-2'-deoxyguanosine (8-OHdG) in DNA isolated from peripheral lymphocytes and 8-OHdG excreted in urine were measured as indices of oxidative DNA damage. Lipid peroxidation was assessed by measuring 8-epiprostaglandin F2alpha (8-EPG) in urine. Plasma levels of selected carotenoids were also determined, with the intention of using a-carotene as a biochemical index of VF consumption. Urinary 8-OHdG and 8-EPG were measured by ELISA, and plasma carotenoids were measured by high performance liquid chromatography. Lymphocyte 8-OHdG was measured by reverse phase high performance liquid chromatography with electrochemical detection. We observed that the structurally related xanthophyll carotenoids, lutein and beta-cryptoxanthin, which occur in dissimilar botanical families, were consistently inversely associated with these oxidative indices. Statistically significant inverse correlations were observed between plasma lutein and/or beta-cryptoxanthin levels and lymphocyte 8-OHdG and urinary 8-EPG. Moreover, an inverse correlation was observed between change in plasma xanthophylls and change in lymphocyte 8-OHdG concentration that occurred during the course of the study. These data lead us to hypothesize that lutein and beta-cryptoxanthin serve as markers for the antioxidant milieu provided by plants from which they are derived. Whether these carotenoids are directly responsible for the observed antioxidant phenomena merits further investigation.

8-Hydroxy-2'-Deoxyguanosine↗

Comparison of fluid-attenuated inversion-recovery MR imaging with CT in a simulated model of acute subarachnoid hemorrhage.

BACKGROUND AND PURPOSE: Because MR imaging is becoming integral to the evaluation and treatment of very early stroke, it is critical to prove that MR imaging is at least as sensitive to acute subarachnoid hemorrhage (SAH) as is CT. The present study was conducted to evaluate the possibility of detecting a small amount of acute SAH diluted by CSF not revealed by CT but identified on fluid-attenuated inversion-recovery (FLAIR) MR images in an in vitro study. METHODS: Acute SAH was simulated with mixtures of artificial CSF and arterial blood (hematocrit [Hct], 45%) ranging from 0% to 100% by volume. We scanned these phantoms with CT and turbo-FLAIR MR imaging (9000/119 [TR/effective TE]; inversion time, 2200 ms; echo train length, 7), and we measured T1 and T2 relaxation times of these phantoms at temperatures within 36 degrees C to 37 degrees C. Plots of CT value from the different blood/water mixture ratios versus Hct were generated and correlated with the average CT value from normal cortex. We measured T1 and T2 relaxation times of these phantoms and normal cortex and generated T2 relaxation curves as a function of effective TE for a specific inversion time (2200), and determined the TR (9000) for the turbo-FLAIR sequence by using a theoretical equation for the turbo inversion recovery signal intensity. RESULTS: Above a Hct of 27% blood, the mixture was denser on CT scans than was the normal cortex. At a selected time longer than an effective TE of 120, above a Hct of 22.4% blood, the mixture was more hyperintense than the normal cortex on turbo-FLAIR images. At selected times longer than an effective TE of 160, above a Hct of 9% blood, the mixture was more hyperintense than was the normal cortex. CONCLUSION: FLAIR imaging is more sensitive than CT in the detection of a small amount of acute SAH diluted by CSF at selected appropriate TE, as determined in an in vitro study.

Acute Disease↗

A network inversion technique for estimating equivalent dipole description of visual evoked potential.

For the activation study of the brain, dipole localization from the scalp potential is one of the most promising techniques to realize a reasonable temporal resolution which cannot be realized in functional MR and PET. The goal of our study is to estimate inversely the electrical brain activity in the form of several dipoles from the scalp potential, using a network inversion technique. As a basic approach, we have inversely estimated several dipoles from the potential distribution on a spherical surface, in the homogeneous sphere model. In the training phase, by expanding the neural network input dimensions being redundant, the network can easily learn the forward mapping. In the inversion phase, the space of the expanded-network-input-vector can be narrowed by introducing a penalty term. Additionally, a consensus term was used to force several dipoles to have a similar orientation. We estimate that this is applicable to the localization of several dipoles that reflect the actual brain activity, especially in the visual evoked potentials.

Brain Mapping↗

Reduction of CSF artifacts on FLAIR images by using adiabatic inversion pulses.

The purpose of this study was to investigate the possibility that some artifactual high signals produced in CSF with fluid-attenuated inversion-recovery MR sequences could be due to inhomogeneity in the amplitude of the initial inversion pulse, and that this problem could be reduced or eliminated by the use of adiabatic inversion pulses. Studies with four volunteers showed dependence of high CSF signals in the posterior fossa on radiofrequency pulse amplitudes and that these signals could be eliminated by the use of adiabatic inversion pulses. Two illustrative clinical cases are included.

Adult↗

[Pulse inversion ultrasonography with ultrasonography contrast media (levovist) in the evaluation of hepatic metastasis].

PURPOSE: To evaluate if Pulse Inversion Harmonic Imaging with contrast agent injection (Levovist) is able to determine an increase of echogenicity in normal hepatic parenchyma, and to compare its capability to detect metastatic focal lesions with that of standard US and spiral CT. To define and standardize the technical and methodological aspects of this new technique. MATERIAL AND METHODS: A selected group of 72 patients (42 males and 30 females) with clinical and instrumental suspect of hepatic metastatic lesions was included in the prospective study. Each patient was examined by conventional ultrasound (US), Pulse Inversion Harmonic Imaging (PI) and spiral-CT (spCT). US examination was performed using an HDI 5000 (ATL, Bothell, USA) equipped with a broadband probe (5.0-2.0 MHz). 2.5 g Levovist (Schering AG-Berlin) was administered intravenously, at concentration of 300 mg/ml and a flow rate of 7 ml/min. Video clips obtained with the acquired images before and after contrast medium administration were transferred to a magnet optic disk unit. Examinations were evaluated by an experienced radiologist blindly on a workstation that allowed a qualitative-quantitative analysis. SpCT images were evaluated separately by another experienced radiologist. US images were evaluated qualitatively (number of lesions, site of lesion, diameter of the smallest lesion detectable) and quantitatively (increase in parenchymal echogenicity 20", 40", 60" and 5' after the injection of contrast agent). RESULTS: In all cases examined, the echogenicity of normal hepatic parenchyma increased after contrast agent administration, reaching a peak of about 250% (1DS) at 60 s and a decreasing gradually in 5 minutes. Conventional US detected 195 focal lesions, CT 231, and US with pulse inversion technique and contrast agent (US-PI) 287. Mean differences among the number of lesions detected by the different techniques per each patient were also calculated. Wilcoxon Signed Rank Test showed a statistically significant difference between US-PI and US (p < .0001), CT and US (p = .0052) and US-PI and CT (p = .0121). US-PI detected the smallest lesions, which went undetected by the CT and conventional US examinations. DISCUSSION AND CONCLUSIONS: In 10 cases (14.3%) contrast enhanced US-PI demonstrated the presence of a number of lesions greater than 5 (diffuse metastatization and inoperability) in comparison to that detected by spCT). The greater echogenicity of normal hepatic parenchyma using pulse inversion technique after Levovist infusion allowed to better demonstrate hepatic metastases. This technique showed a higher identification rate of small lesions in comparison to basal examination and to spiral CT. Contrast enhanced US-PI demonstrated a remarkable increase in echogenicity of hepatic parenchyma in portal phase. The technique significantly improves the detection of focal lesions allowing visualization of smaller lesions compared to CT and US. These results indicate that the technique could be used in the staging of liver metastasis. However, large multicentric trials are required to validate US-PI and better define its role in the work-up of patients with neoplastic disorder.

Adult↗

5-hydroxytryptamine2A receptor inverse agonists as antipsychotics.

We have used a cell-based functional assay to define the pharmacological profiles of a wide range of central nervous system active compounds as agonists, competitive antagonists, and inverse agonists at almost all known monoaminergic G-protein-coupled receptor (GPCR) subtypes. Detailed profiling of 40 antipsychotics confirmed that as expected, most of these agents are potent competitive antagonists of the dopamine D2 receptor. Surprisingly, this analysis also revealed that most are potent and fully efficacious 5-hydroxytryptamine (5-HT)2A receptor inverse agonists. No other molecular property was shared as universally by this class of compounds. Furthermore, comparisons of receptor potencies revealed that antipsychotics with the highest extrapyramidal side effects (EPS) liability are significantly more potent at D2 receptors, the EPS-sparing atypical agents had relatively higher potencies at 5-HT2A receptors, while three were significantly more potent at 5-HT2A receptors. Functional high-throughput screening of a diverse chemical library identified 530 ligands with inverse agonist activity at 5-HT2A receptors, including several series of compounds related to known antipsychotics, as well as a number of novel chemistries. An analog of one of the novel chemical series, AC-90179, was pharmacologically profiled against the remaining monoaminergic GPCRs and found to be a highly selective 5-HT2A receptor inverse agonist. The behavioral pharmacology of AC-90179 is characteristic of an atypical antipsychotic agent.

Animals↗

Ganglioside GM2 levels in human melanoma cells: inverse correlation with lysosomal beta-hexosaminidase A activity.

GM2 is usually significantly elevated in human melanoma cells. The lysosomal hydrolase beta-hexosaminidase A (Hex A), is an isoenzyme required for terminal GalNAc hydrolysis from intact GM2 to GM3. The objective of the present studies is to determine if the elevated levels of gangliosides, particularly GM2, correlate with the activity of Hex A in cultured melanoma cells. The Hex A activity in 13 melanoma cell lines ranged from 26%-88.3% There was a inverse correlation between GM2 nmole/g and Hex A activity (r = -0.48; p less than 0.003). An inverse correlation (p less than 0.03) occurred between GD2 nmole/g and Hex A activity. There was an inverse correlation (r = -0.53; p less than 0.05 and r = -0.51; p less than 0.05, respectively) between the ratio of substrate/product (GM2/GM3) and (GD2/GD3) and Hex A activity. These results indicate that the level of GM2 in melanoma is inversely correlated with the level of activity of Hex A.

Analysis of Variance↗

Clinical analysis of 48 cases of inverse psoriasis: a hospital-based study.

Inverse psoriasis, rare in clinical practice, refers to psoriasis only or mainly occurring at flexural sites, such as the axilla, antecubital fossae, popliteal fossae, and inguinal creases. It is also known as flexural psoriasis. With a total collection of psoriatic cases from September 2002 to December 2003 at Xijing hospital, we made a retrospective analysis of the disease history, clinical characteristics, and treatment of the patients affected with inverse psoriasis. The results showed that the major clinical manifestations of inverse psoriasis were sharply demarcated erythematous plaques with varying degrees of infiltration and minimal or no scales. Affected areas often involve the groin, axilla, genitals, and umbilicus. The disease responds well to the narrow band UVB therapy. Compared with common psoriasis, inverse psoriasis has similar and unique characteristics in terms of the affected areas, clinical symptoms, and responses to the treatment.

Adolescent↗

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↗

Effect of unilateral functional instability of the ankle on postural sway and inversion and eversion strength.

OBJECTIVE: The purpose of this study was to determine if individuals with unilateral functional ankle instability had decreased ability to maintain postural sway, as well as decreased isokinetic eccentric strength of ankle evertors and invertors. DESIGN AND SETTING: SUBJECTS WITH NO PREVIOUS HISTORY OF ANKLE INJURY WERE COMPARED WITH SUBJECTS WITH FUNCTIONAL ANKLE INSTABILITY ON THE FOLLOWING TESTS: isokinetic eccentric inversion and eversion strength and measures of single-limb postural sway. SUBJECTS: EIGHTEEN SUBJECTS PARTICIPATED IN THIS STUDY: 9 subjects in the functional instability (FI) group (age = 22.89 +/- 3.18 yr, ht = 181 +/- 6.0 cm, wt = 80.25 +/- 12.2 kg) and 9 noninjured (NI) controls (age = 26.22 +/- 2.34 yr, ht = 170 +/- 10.0 cm, wt = 65.08 +/- 12.03 kg). MEASUREMENTS: Subjects performed postural sway assessment on a balance system under static and dynamic conditions. Ankle inversion and eversion eccentric strength were evaluated at 90 degrees /sec using an isokinetic dynamometer. Additionally, we assessed the degree of mechanical instability in the FI group with a series of stress radiographs. RESULTS: No significant differences in single-limb postural sway measures or in eversion strength between limbs in the FI group or between groups were found. A significant group-by-limb interaction was present in inversion peak torque; however, post hoc testing revealed the only difference to be between the dominant and nondominant limbs of the NI group. CONCLUSIONS: Postural sway and inversion and eversion eccentric peak torque are not affected by functional instability of the ankle. Alternate methods of postural sway assessment and ankle strength measurement are discussed as possible areas for future study.

Journal Article↗

Vascularization of liver tumors - preliminary results with Coded Harmonic Angio (CHA), phase inversion imaging, 3D power Doppler and contrast medium-enhanced B-flow with second generation contrast agent (Optison).

PURPOSE: To investigate the dynamic value of contrast medium-enhanced ultrasonography with Optison for appraisal of the vascularization of hepatic tumors using harmonic imaging, 3D-/power Doppler and B-flow. MATERIALS/METHODS: 60 patients with a mean age of 56 years (range 35-76 years) with 93 liver tumors, including histopathologically proven hepatocellular carcinoma (HCC) [15 cases with 20 lesions], liver metastases of colorectal tumors [17 cases with 33 lesions], metastases of breast cancer [10 cases with 21 lesions] and hemangiomas [10 cases with 19 lesions] were prospectively investigated by means of multislice CT as well as native and contrast medium-enhanced ultrasound using a multifrequency transducer (2.5-4 MHz, Logig 9, GE). B scan was performed with additional color and power Doppler, followed by a bolus injection of 0.5 ml Optison. Tumor vascularization was evaluated with coded harmonic angio (CHA), pulse inversion imaging with power Doppler, 3D power Doppler and in the late phase (>5 min) with B-flow. In 15 cases with HCC, i.a. DSA was performed in addition. The results were also correlated with MRT and histological findings. RESULTS: Compared to spiral-CT/MRT, only 72/93 (77%) of the lesions could be detected in the B scan, 75/93 (81%) with CHA and 93/93 (100%) in the pulse inversion mode. Tumor vascularization was detectable in 43/93 (46%) of lesions with native power Doppler, in 75/93 (81%) of lesions after administering contrast medium in the CHA mode, in 81/93 (87%) of lesions in the pulse inversion mode with power Doppler and in 77/93 (83%) of lesions with contrast-enhanced B-flow. Early arterial and capillary perfusion was best detected with CHA, particularly in 20/20 (100%) of the HCC lesions, allowing a 3D reconstruction. 3D power Doppler was especially useful in investigating the tumor margins. Up to 20 min after contrast medium injection, B-flow was capable of detecting increased metastatic tumor vascularization in 42/54 (78%) of cases and intratumoral perfusion in 17/20 (85%) of HCC cases. All 19 hemangiomas were correctly classified by phase inversion imaging. CONCLUSIONS: Contrast medium-enhanced ultrasound investigation of liver tumors with Optison allowed reliable detection of tumor foci and, in most cases, appraisal of tumor vascularization. The time available for evaluation of tumor margin vascularization was substantially longer in B-flow.

Adult↗