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.

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.

Mechanism of neurotensin depolarization of rabbit colonic smooth muscle.

The aims of this study were (1) to measure the effect of neurotensin on the membrane potential of circular muscle of the distal colon of the rabbit and (2) to determine the mechanism by which neurotensin affects the membrane potential of this tissue. The membrane potential was measured with microelectrodes placed intracellularly and the double sucrose gap. Neurotensin (10(-11) M to 10(-7) M) dose-dependently decreased the membrane potential. The maximum decrease in membrane potential occurred with 10(-9) M neurotensin. The ED50 of neurotensin depolarization of the membrane potential was 0.87 +/- 0.33 X 10(-10) M. The frequency of the slow waves was unchanged after neurotensin. The voltage response to a constant current pulse decreased as the concentration of neurotensin increased. The amplitude of the voltage response after a 0.6 microA current pulse decreased by 6 +/- 0.5 mV after neurotensin (10(-7) M) compared to the Krebs control (P less than 0.05). Decreasing the [Na+]o to 0-23 mM did not affect the decrease in membrane potential after neurotensin. However, perfusion with a test solution containing no added Ca2+ or verapamil (10(-5) M) inhibited neurotensin depolarization of the tissue. Evidence was found that neurotensin depolarizes colonic circular smooth muscle, and the decrease in membrane potential is associated with an increase in conductance which is dependent on influx of Ca2+.

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.

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.

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.

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.

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.

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.

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)

The persistence of hepatitis A IgM antibody after acute clinical hepatitis A.

Hepatitis A IgM antibody (IgM anti-HAV), detected by commercially available solid-phase radioimmunoassay, is an accepted marker of acute viral hepatitis A infection. However, persistence of this serological marker far beyond the acute illness and immediate convalescent period has been reported. To determine the persistence of IgM anti-HAV following clinically manifest acute hepatitis A infection, 59 patients with this diagnosis were followed prospectively until this marker disappeared or persisted for greater than 60 days. Timed from the onset of jaundice, IgM anti-HAV persisted for less than 30 to greater than 420 days; most patients became seronegative by 120 days. These findings suggest that some patients may become seronegative early in the disease course while others (13.5%) remain positive for prolonged periods greater than 200 days. Awareness of this marked variability is important in the interpretation of IgM anti-HAV as a serologic marker of recent hepatitis A infection.

Effects of bethanechol and the octapeptide of cholecystokinin on colonic smooth muscle in the cat.

The aim of this study is to compare the action of the cholinergic agonist, bethanechol, with the action of the octapeptide of cholecystokinin (CCK-OP) on feline circular colonic smooth muscle membrane potential and isometric tension, using the double sucrose gap. Depolarization of the membrane greater than 10 mV by K+ or bethanechol increased tension and spontaneous spike activity. CCK-OP (10(-9) M) depolarized the membrane (6.1 +/- 1.3 mV) without an increase in tension or spike activity. Depolarization of the membrane by increasing [K+]o was associated with a decrease in the membrane resistance. The slow-wave duration (2.3 +/- 0.2 s) was unchanged by administration of K+ or bethanechol but was prolonged after increasing concentrations of CCK-OP. The maximum effect occurred at a 10(-10) M concentration of CCK-OP (4.5 +/- 0.4 s, P less than 0.01). At higher concentrations of CCK-OP (greater than 10(-10) M), the slow-wave pattern became disorganized. Addition of increasing concentrations of [K+]o or bethanechol, but not CCK-OP, stimulated a concentration-dependent increase in the maximum rate of rise (dV/dtmax) of an evoked spike potential. These studies suggest 1) bethanechol decreased the membrane potential without altering the slow-wave activity, whereas CCK-OP has a minimal effect on the membrane potential but distorted the slow-wave shape; 2) an increased amplitude of the spike and dV/dtmax of the spike were associated with an increase in phasic contractions after bethanechol or increased [K+]o; 3) the lack of an increase in the spike amplitude and the dV/dtmax to CCK-OP was associated with no increase in phasic contraction.

Effect of acute experimental colitis on rabbit colonic smooth muscle.

The membrane potential and contractile activity of colonic circular smooth muscle from New Zealand White rabbits were studied after the production of acute experimental colitis. Colitis was induced in the distal colon by rectal infusion of formaldehyde solution, followed by an intravenous bolus of soluble immune complexes. Despite active mucosal inflammation, there are only occasional inflammatory cells in the muscularis. Electrophysiological studies on tissue from control rabbits and rabbits with colitis were performed using double sucrose gap and intracellular microelectrode techniques. The resting membrane potential was lower (-44 +/- 3 mV) in muscle from rabbits with colitis compared with control animals (-54 +/- 2 mV) (P less than 0.02). Amplitude of the electrotonic potential after a hyperpolarizing current pulse was decreased (P less than 0.05) and the time constant was shortened (P less than 0.01) in muscle from animals with colitis compared with normal animals. Amplitude (13.1 +/- 2.3 mV) and maximum rate of rise (0.24 +/- 0.06 V/s) of the spike potential, initiated by a depolarizing current pulse, were decreased in muscle from animals with colitis compared with muscle from healthy animals (P less than 0.001). Isometric tension generation after electrical and chemical depolarization of the membrane or bethanechol administration was decreased (P less than 0.001) in muscle from colitic animals. These studies suggest 1) membrane resistance and membrane potential are decreased in muscle strips from animals with colitis; and 2) there is a disturbance in the electrical and mechanical response of these tissues after stimulation.

The effect of large volume paracentesis on plasma volume--a cause of hypovolemia?

Large volume paracentesis, while effectively relieving symptoms in patients with tense ascites, has been generally avoided due to reports of complications attributed to an acute reduction in intravascular volume. Measurements of plasma volume in these subjects have been by indirect methods and have not uniformly confirmed hypovolemia. We have prospectively evaluated 18 patients (20 paracenteses) with tense ascites and peripheral edema due to chronic liver disease undergoing 5 liter paracentesis for relief of symptoms. Plasma volume pre- and postparacentesis was assessed by a 125I-labeled human serum albumin dilution technique as well as by the change in hematocrit and postural blood pressure difference. No significant change in serum sodium, urea nitrogen, hematocrit or postural systolic blood pressure difference was noted at 24 or 48 hr after paracentesis. Serum creatinine at 24 hr after paracentesis was unchanged but a small but statistically significant increase in serum creatinine (+0.1 +/- 0.3 mg per dl, p less than 0.01) was noted at 48 hr postparacentesis. Plasma volume changed -2.7% (n = 6, not statistically significant) during the first 24 hr and -2.8% (n = 12, not statistically significant) during the 0- to 48-hr period. No complications from paracentesis were noted. These results suggest that 5 liter paracentesis for relief of symptoms is safe in patients with tense ascites and peripheral edema from chronic liver disease.

Hypersensitive prostaglandin and thromboxane response to hormones in rabbit colitis.

Inflammation of the colon is associated with increased production of prostaglandins (PG) and thromboxanes (Tx), and these eicosanoids may contribute to the inflammatory, secretory, and motility dysfunctions in colitis. To evaluate the potential role of peptide hormones in the enhanced eicosanoid release, colitis was established in rabbits by a delayed-type hypersensitivity reaction to dinitrochlorobenzene and by an immune-complex-mediated reaction. PG and Tx were identified in the venous effluent of isolated perfused colons by radiochromatography after [14C]arachidonic acid prelabeling, as well as by bioassay, and then quantitated by immunoassay. The two colitis models were morphologically similar. Basal release of PGE2, PGI2, and TxA2 was two- to threefold greater from colitis tissue than from control tissue. Bradykinin (BK) and angiotensin II (ANG II) increased release of 14C-labeled eicosanoids, whereas several gastrointestinal hormones had no effect. In control colons, BK and ANG II increased PGE2 and PGI2 release (by about 2-fold) but did not alter TxA2. In contrast, BK and ANG II markedly exaggerated the release of eicosanoids in colitis. BK increased TxA2 release with 10-ng bolus injections in colitis, but there was no response with up to 10-micrograms bolus injections in control colons. The BK-induced Tx release in colitis was associated with an increase in vascular resistance (measured as perfusion pressure). Infusion of the selective Tx inhibitors dazoxiben and OKY-046 reduced TxB2 release by 96% and blunted the transient rise in perfusion pressure (from 17 +/- 5 to 5 +/- 2 mmHg). Since BK and possibly ANG II are increased at sites of inflammation, the hypersensitive eicosanoid response to these peptides may augment the eicosanoid-mediated manifestations of colitis.