Transition into driven equilibrium of the balanced steady-state free precession as an ultrafast multisection T2-weighted imaging of the brain.

BACKGROUND AND PURPOSE: Current T2-weighted imaging takes >3 minutes to perform, for which the ultrafast transition into driven equilibrium (TIDE) technique may be potentially helpful. This study qualitatively and quantitatively evaluates the imaging of transition into driven equilibrium of the balanced steady-state free precession (TIDE) compared with TSE and turbo gradient spin-echo on T2-weighted MR images. MATERIALS AND METHODS: Thirty healthy volunteers were examined with T2-weighted images by using TIDE, TSE, and turbo gradient spin-echo sequences. Imaging was evaluated qualitatively by 2 independent observers on the basis of a 4-point rating scale regarding contrast characteristics and artifacts behavior. Image SNR and contrast-to-noise ratio were quantitatively assessed. RESULTS: TIDE provided T2-weighted contrast similar to that in TSE and turbo gradient spin-echo with only one-eighth of the scan time. TIDE showed gray-white matter differentiation and iron-load sensitivity inferior that of TSE and turbo gradient spin-echo, but with improved motion artifacts reduction on qualitative scores. Nonmotion ghosting artifacts were uniquely found in TIDE images. The overall SNRs of TSE were 1.9-2.0 times those of turbo gradient spin-echo and 1.7-2.2 times of those of TIDE for brain tissue (P < .0001). TIDE had a higher contrast-to-noise ratio than TSE (P = .169) and turbo gradient spin-echo (P < .0001) regarding non-iron-containing gray matter versus white matter. TIDE had a lower contrast-to-noise ratio than turbo gradient spin-echo and TSE (P < .0001) between iron-containing gray matter and white matter. CONCLUSIONS: TIDE provides T2-weighted images with reduced scan times and reduced motion artifacts compared with TSE and turbo gradient spin-echo with the trade-off of reduced SNR and poorer gray-white matter differentiation.

Susceptibility-weighted imaging, an additional tool to diagnose brain death: initial experience.

We describe findings suggestive of brain death on susceptibility-weighted imaging. We retrospectively reviewed brain magnetic resonance (MR) images of 15 patients who had cardiac arrest and found four cases with evidence of brain death. We then reviewed susceptibility-weighted imaging (SWI) findings on these cases. SWI images in the four cases with brain death showed deoxygenated blood in intracranial arteries. This preliminary result suggests that SWI may be used to diagnose brain death.

Extratesticular epidermoid cyst mimicking enlarged testis.

Epidermoid cysts are benign simple epithelial tumors usually appearing as hypoechoic lesions with scattered echogenic reflectors on sonography. Herein, we present a 53-year-old man with an extratesticular epidermoid cyst in the right scrotum which shows confusing sonographic findings, normal-appearing echogenicity of the lesion and atrophied testis, which lead to a diagnostic dilemma. With a variety of sonographic presentations in extratesticular epidermoid cysts, magnetic resonance (MR) imaging could play a complementary role in difficult cases.

CT Angiographic Diagnosis of a Ruptured Intraventricular Arteriovenous Malformation in a Teenager Playing a Video Game.

Intraventricular arteriovenous malformation (AVM) is a rare congenital vascular disorder that is often associated with primary intraventricular hemorrhage (IVH) and a rapid clinical course. Acute imaging diagnosis requires depiction of both the location of hemorrhage and vascular nidus for emergent management. In this report, a 17-year-old teenager developed primary IVH with presentation of consciousness change during a video game. Multidetector-row computed tomographic angiography (CTA) demonstrated an AVM in the right lateral ventricle and its angioarchitectural relationship to the surrounding intracranial structures. Although selective angiography is essential both in planning treatment for cerebral AVMs and in establishing the final diagnosis, CTA can be an important first-line imaging modality to quickly confirm the diagnosis and hence initiate prompt management.

Prediction of conversion from clinically isolated syndrome to clinically definite multiple sclerosis according to baseline MRI findings: comparison of revised McDonald criteria and Swanton modified criteria.

BACKGROUND: The International Panel on the Diagnosis of Multiple Sclerosis first incorporated abnormalities demonstrated by brain and spinal cord MRI into the diagnostic criteria (McDonald criteria) for multiple sclerosis (MS), which were later revised in 2005. In 2006, Swanton and colleagues modified the MRI criteria to simplify and speed the diagnosis. OBJECTIVE: The purpose of this study was to compare the ability of two sets of criteria (the revised McDonald MRI criteria and Swanton's modified criteria) to predict conversion from clinically isolated syndrome (CIS) to clinically definite multiple sclerosis (CDMS) from baseline MRI findings. METHODS: Sixty-four patients presenting with CIS suggestive of multiple sclerosis were recruited from 2001 to 2006 and followed up for at least 2 years. Their baseline brain and spinal cord MRI studies were retrospectively evaluated. The patients who developed CDMS during follow-up were treated as positive cases. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of the two MRI dissemination-in-space criteria were calculated. RESULTS: Thirty patients (46.9%) converted to CDMS. The sensitivity specificity, PPV, NPV and accuracy (%) of the revised McDonald criteria were 53, 100, 100, 71 and 78, respectively, while those for Swanton's modified criteria were 60, 100, 100, 74 and 81. CONCLUSIONS: In conclusion, Swanton's modified criteria are more sensitive and accurate (but not significantly so). However, Swanton's criteria are simpler to use and have equally high specificity and PPV.

Solitary lymphangioma of the spleen: dynamic MR findings with pathological correlation.

Solitary lymphangioma of the spleen is an extremely rare, benign vasoformative tumour that typically shows no notable enhancement on imaging studies. Few descriptions of the MRI features have been reported and, to our knowledge, the findings on dynamic gadolinium-enhanced MR images have never been described. We report a case in which MR images showed diffuse and prolonged enhancement of a splenic mass. On histological correlation, splenic lymphangiomas with abundant fibrous stroma may account for this specific enhancing pattern.

Malignant tumor of testis imitating epididymo-orchitis.

From April 1994 to November 2004, a total of 65 patients with malignant testicular tumors underwent surgical interventions in our hospital. Clinical presentations and imaging findings led to quiet accurate preoperative diagnosis of malignant tumor, except for one case, a 29-year-old male, presenting with episodes of painful swelling in the right scrotum. All the findings including color duplex ultrasonography (US) and scintigraphy were considered as right epididymo-orchitis. Unfortunately, the patient presented with metastatic lymphadenopathy of the neck from mixed germ cell tumor of the testis 2 months later. Close follow-up for patients with suspected epididymo-orchitis is very important.

Tyrosine-kinase expression profiles in human gastric cancer cell lines and their modulations with retinoic acids.

Many protein tyrosine kinases are key regulators involved in cellular growth, differentiation, development, apoptosis and signal transduction pathways. Obtaining a comprehensive tyrosine-kinase expression profile in tumour cells is essential to learning more about their oncogenic potentials and responses to various chemotherapeutic reagents - such as retinoic acid, which has been shown to suppress the growth of gastric cancer cells and modulate gene expression. Expression of tyrosine kinases in retionic acid-treated cancer cells was investigated by reverse trancriptase-polymerase chain reaction (RT-PCR) and a novel restriction analysis of gene expression (RAGE) display technique. We first established comprehensive tyrosine-kinase profiles in different human gastric cancer cell lines. In cells treated with 9-cis-retinoic acid or all-trans-retinoic acid, we found that two PTKs (Eph and Hek5) appeared to be upregulated. In the present study, we demonstrate an efficient and simple RAGE approach for examining tyrosine kinases' expression in tumour cells and their alterations following drug treatments.

Polymorphisms of GA/GT microsatellite loci from Anguilla japonica.

Six novel microsatellite loci, containing (GA)(15\N17) or (GT)(10\N19) perfect tandem repeats, were isolated and characterized for the catadromous eel Anguilla japonica. The allelic size of the 6 loci ranged from 79 to 226 bp in length. All loci were polymorphic with a mean number of 14.7 alleles per locus and a mean heterozygosity of 0.67, suggesting higher polymorphism than that of freshwater and anadromous fishes, but lower than that of marine fishes. Genotype diversity of the 6 loci ranged from 0.22 to 0.61 with a mean value of approximately 0.5. Cross-species amplification showed that 5 of the 6 microsatellite primers proved to be useful in addressing questions of population genetics for all Anguilla species.

Tyrosine kinases and gastric cancer.

Carcinoma of the stomach is one of the most prevalent cancer types in the world today. Two major forms of gastric cancer are distinguished according to their morphological and clinicopathological classifications (well differentiated/intestinal type and poorly differentiated/diffuse type), characteristics that could also be attributed to the altered expression of different types of oncogenes or tumor suppressor genes. Significant differences exist for gastric cancer incidence comparing people of different ethnic origins, implicating various genetic and epigenetic factors for gastric oncogenesis. There are only a limited number of molecular markers available for gastric cancer detection and prognostic evaluation, among which are tyrosine kinases. There is convincing evidence that tyrosine kinases are involved in oncogenesis and disease progression for many human cancers. Amplifications of certain tyrosine kinases (c-met, k-sam and erbB2/neu) have been associated with human gastric cancer progression. Alternatively spliced transcripts and enhanced protein-expression levels for some of these tyrosine kinases are correlated with clinical outcomes for gastric cancer patients. With advent of high throughput techniques, it is now possible to detect nearly all expressed tyrosine kinases in a single screen. This increases the chance to identify additional tyrosine kinases as predictive markers for gastric cancers. In this article, we will first review the literature data concerning certain tyrosine kinases implicated in gastric carcinogenesis and then summarize more recent work which provide comprehensive tyrosine kinase profiles for gastric cancer specimens and cell lines. Two new gastric cancer molecular markers (tie-1 and mkk4) have been identified through the use of these profiles and demonstrated effective as clinical prognostic indicators.

Molecular characterization of germline mutations in the BRCA1 and BRCA2 genes from breast cancer families in Taiwan.

A total of 18 families with multiple cases of breast cancer were identified from southern Taiwan, and 5 of these families were found to carry cancer-associated germline mutations in the BRCA1 and BRCA2 genes. One novel cryptic splicing mutation of the BRCA1 gene, found in two unrelated families, was shown to be a deletion of 10 bp near the branch site in intron 7. This mutation causes an insertion of 59 nucleotides derived from intron 7 and results in a frameshift, leading to premature translational termination of BRCA1 mRNA in exon 8. Deletions of 2670delC, 3073delT and 6696-7delTC in the BRCA2 gene were found in three other breast cancer families. All three deletions are predicted to generate frameshifts and to result in the premature termination of BRCA2 protein translation. Several genetic polymorphisms in both BRCA1 and BRCA2 genes were also detected in this investigation.

Limb Regeneration in the Eye Sockets of Crabs.

The eyestalks of crabs were removed and various tissues of the limbs were autotransplanted into the empty eye sockets to study the capacity of the limb tissue to regenerate in a heterotopic site. Autotransplantation of walking leg tissues into the eye sockets was able to regenerate complete walking legs in the new site. Autotransplantation of tissues of claw digit (dactyl and pollex) or more proximal claw segments (ischium and merus/carpus joint) could regenerate complete claws in the eye sockets. If the autotransplant of claw tissue was contralateral, claws could regenerate with host-site handedness. Sham operations or autotransplantation of frozen claw tissue did not induce regeneration in the eye sockets. These results demonstrate that complete crab claws can regenerate from the eye sockets by autotransplantation of live limb tissue and that the regeneration is not due to the traumatic effect of transplantation. The structure of the limbs regenerated in the eye sockets was determined by the source of the transplanted tissue. Complete claws resulted from autotransplantation of the tissues of the most distal claw segments (claw digits), and the most distal claw segments regenerated first, followed by the proximal claw segments in subsequent molts. Thus tissue from distal portions of crab claw can regenerate proximal portions of the claw in the eye sockets. Such a mode of regeneration is not consistent with the distalization rule of the polar coordinate model, which proposes that distal portions of the limb cannot regenerate proximal portions and that the direction of limb regeneration is always from proximal to distal.

Homeotic Transformation of Crab Walking Leg into Claw by Autotransplantation of Claw Tissue.

Homeotic transformation is defined as transformation of one body part into the likeness of something else. By autotransplantation of crab claw tissue into the autotomized stump of the fourth walking leg, the stump can regenerate a complete claw. Frozen claw tissue, sham operation, or walking leg tissue had no such activity. Contralateral autotransplantation of claw tissue into the autotomized stump of the fourth walking leg can induce the regeneration of a claw with normal handedness. Most of the transformed claws combined features of the claw and the walking leg, suggesting that both host and donor tissues play a role in regeneration. Three possible mechanisms that might account for limb transformation are discussed. Simple intercalary regeneration does not explain all of the observations, but some regulatory events might be taking place during regeneration. Two other processes--secretion of some morphogen by the claw tissue and alteration in the expression of Hox genes--offer alternatives that might explain the results of this study.

Effect of prostaglandin E2 on rabbit colonic smooth muscle cell contraction.

Isolated circular smooth muscle cells from the rabbit distal colon were used to study the effect of prostaglandin E2 (PGE2) on bethanechol-stimulated smooth muscle cell contraction. Contraction was expressed as the percentage decrease in mean cell length compared with unstimulated cells. Incubation with different concentrations of PGE2 (10(-10)-10(-6) M) did not cause contraction or relaxation of unstimulated smooth muscle cells. Bethanechol stimulated a dose-dependent contraction that was maximal at 30 s. The threshold for bethanechol-stimulated contraction was 10(-11) M; the ED50 was 10(-10) M; and the maximum contraction (23.0 +/- 1.8%) occurred at 10(-8) M. Preincubation with PGE2 reduced both the efficacy and potency of bethanechol-stimulated contraction. Preincubation with 8-bromoadenosine 3',5'-cyclic monophosphate (8-BrcAMP) or dibutyryl-cAMP reduced the efficacy of bethanechol-stimulated contraction without affecting potency. Increasing concentrations of PGE2 stimulated a dose-dependent increase in the production of intracellular cAMP (P less than 0.05). These studies show that PGE2 inhibits bethanechol-stimulated contraction of isolated colonic circular myocytes and is associated with increased production of intracellular cAMP. There is also a cAMP-independent effect of PGE2 on the potency of bethanechol stimulation.

Cultured circular smooth muscle from the rabbit colon.

Although cultured vascular smooth muscle cells have been extensively characterized and investigated, there are very few studies of cultured intestinal smooth muscle cells. The aim of this study was to culture colonic smooth muscle (CSM) cells from the rabbit colon. Freshly isolated CSM cells from the circular muscle layer of the distal colon were prepared by collagenase digestion. In primary culture, CSM cells attached to the culture vessels by 48 to 72 h, proliferated by 3 to 7 d, and reached confluency by 14 to 17 d with a "hill-and-valley" pattern. Spontaneous contractions were not observed at any time at 21 degrees or 37 degrees C. Confluent primary cultures were greater than 95% CSM cells, as identified by intensely positive immunofluorescent staining to smooth muscle actin-specific CGA7 and muscle-specific HHF-35 monoclonal antibodies. Transmission electron microscopy of freshly isolated and proliferating CSM cells revealed ultrastructural features consistent with smooth muscle cells. We successfully cultured CSM cells of the rabbit from freshly isolated cells and validated these CSM cells by electron microscopy and immunocytochemical staining. These highly pure primary cultures may be used to investigate numerous aspects of CSM cell metabolism and physiology.

Visceral surface oxygen tension in experimental colitis in the rabbit.

The impairment of bowel healing that is characteristic of inflammatory bowel disease (IBD) is poorly understood. Because bowel healing is related to the adequacy of perfusion in other circumstances, we studied bowel surface oxygen tension (PSO2), which is related to bowel perfusion, in rabbits with IBD. Both cell-mediated (n = 17) and immune complex-mediated (n = 10) colitis caused marked attenuation of colon PSO2. Control (n = 13) left colon PSO2 was 36 +/- 5 (SEM) torr. In mild colitis, left colon PSO2 fell to 11 +/- 5 torr, and in severe colitis it fell to 4 +/- 1 torr (p less than 0.01 for each compared with control). These changes occurred irrespective of the mechanism of induction of colitis. Gastric and small intestinal PSO2 were unaffected. Hepatic and renal PSO2 were decreased in severe colitis only. The presence of decreased PSO2 was a better marker for the presence of IBD than was histologic evaluation. It is suggested that attenuation of PSO2 may be a marker for the physiologic activity of IBD. If this is so, PSO2 may prove a useful adjunct in the operative management of IBD.

Exaggerated prostaglandin production by colonic smooth muscle in rabbit colitis.

Enhanced production of arachidonic acid metabolites by colonic mucosa has been reported in ulcerative colitis as well as in experimental models of colitis. However, production of these compounds by colonic smooth muscle from colitis subjects has not been described. To evaluate arachidonic acid metabolism in colonic tissue, we studied the production of prostaglandin E2 (PGE2) by mucosa and muscularis propria in two experimental models of acute colitis in which inflammation was virtually confined to the mucosa. Colitis was induced in New Zealand white rabbits by either of two methods, dinitrochlorobenzene (DNCB) sensitization or formalin followed by intravenous soluble immune complexes (F-IC). Arachidonic acid metabolites were identified from in vitro incubations of tissue with [14C] arachidonic acid by thin layer chromatography followed by autoradiography. The major eicosanoid metabolites of colitis mucosa and muscularis were 14C-labeled prostaglandin E2, prostaglandin F2a and 6-keto prostaglandin F1 alpha. PGE2 was quantitated from incubations without labeled arachidonic acid by radio-immunoassay. PGE2, expressed as picograms per milligram protein per 20 min (mean +/- SEM), was increased in F-IC mucosa (1093 +/- 141 vs 645 +/- 189, P less than 0.05) and DNCB mucosa (1354 +/- 487 vs 527 +/- 222, P less than 0.05) compared to normals. PGE2 production by uninflamed colitis muscularis propria was also increased five- to eightfold compared to normals for F-IC muscularis (1594 +/- 329 vs 189 +/- 35, P less than 0.005) and DNCB muscularis (1287 +/- 171 vs 225 +/- 72, P less than 0.005). Thus, the adjacent inflammation in colonic mucosa may induce increased eicosanoid production by the uninflamed smooth muscle.(ABSTRACT TRUNCATED AT 250 WORDS)

Role of inflammatory mediators in colonic smooth muscle function in ulcerative colitis.

Patients with ulcerative colitis have a decrease in colonic motility which may increase their diarrheal symptoms. Studies in patients with ulcerative colitis showed that the postprandial spike response was slightly decreased and the intraluminal pressure response was absent. In vitro studies showed that the circular smooth muscle, obtained from patients with ulcerative colitis or from a rabbit model of experimental colitis, generated decreased force compared to muscle not associated with mucosal inflammation. The decrease in muscle contraction was observed with bethanechol stimulation or electrical field stimulation. Since the response to an increased extracellular concentration of potassium [( K+]0) was also diminished, the decreased response appears to be caused by an abnormality in the intrinsic contractile mechanism of colonic smooth muscle. Further studies are necessary to determine if metabolic abnormalities are present in the colonic muscle in patients with colitis.