Assessment of the developmental totipotency of neural cells in the cerebral cortex of mouse embryo by nuclear transfer

When neural cells were collected from the entire cerebral cortex of developing mouse fetuses (15.5-17.5 days postcoitum) and their nuclei were transferred into enucleated oocytes, 5.5% of the reconstructed oocytes developed into normal offspring. This success rate was the highest among all previous mouse cloning experiments that used somatic cells. Forty-four percent of live embryos at 10.5 days postcoitum were morphologically normal when premature and early-postmitotic neural cells from the ventricular side of the cortex were used. In contrast, the majority (95%) of embryos were morphologically abnormal (including structural abnormalities in the neural tube) when postmitotic-differentiated neurons from the pial side of the cortex were used for cloning. Whereas 4.3% of embryos cloned with ventricular-side cells developed into healthy offspring, only 0.5% of those cloned with differentiated neurons in the pial side did so. These facts seem to suggest that the nuclei of neural cells in advanced stages of differentiation had lost their developmental totipotency. The underlying mechanism for this developmental limitation could be somatic DNA rearrangements in differentiating neural cells.

Unusual liver carcinomas with sarcomatous features: analysis of four cases

We recently examined the clinicopathological and immunohistochemical features of four cases of primary hepatic carcinoma with sarcomatoid elements. Three of the four patients had associated ordinary hepatocellular carcinoma (HCC) and one had a sarcomatoid carcinoma with no apparent elements of HCC. The presenting symptoms were high fever and hypochondralgia in three patients, and right hypochondralgia without a high fever in one. The preoperative diagnoses were liver abscess in two patients, HCC in one, and cholangioma in one. Preoperative imaging showed necrotic change or abscess formation in the tumors. The sarcomatous elements showed a positive reaction to vimentin in three patients, but the ordinary HCC cells did not. Macroscopically, the tumors appeared as a single nodule with pericapsular growth. The prognoses of these patients were poor due to the early development of intrahepatic or distal metastases. We conclude that symptoms such as a high fever or hypochondralgia are characteristics of these tumors and that they may be histogenetically derived from a dedifferentiation of HCC, although no elements of HCC were found in one of our cases.

The cadherin-related neuronal receptor family: a novel diversified cadherin family at the synapse

The cadherin-related neuronal receptor (CNR) family has been identified as a receptor family that cooperates with Fyn, a member of the Src family of tyrosine kinases. The CNR family is composed of 14 members in mice and 15 members in humans. The mRNAs of CNRs are highly expressed in the brain and CNR1 protein is localized at synaptic junctions. Hence CNR family proteins are synaptic cadherins. The unique structure of CNR family cDNAs, which is characterized by complete DNA sequence identity among their 3'-termini including a part of the coding region, prompted us to investigate the genomic organization of this family. The genomic organization of CNRs is divided into 'variable' and 'constant' region exons, analogous to immunoglobulin and T cell receptor gene clusters. This organization raised the possibility that the CNR gene cluster may undergo somatic DNA rearrangement or trans-splicing and produce diversified gene products. Although it is not yet clear that the CNR gene cluster in the neuronal genomic DNA is somatically changed, a recent study suggested the occurrence of trans-transcripts and accumulation of somatic mutations in CNR transcripts (Genes Cells 6 (2001) 151). These results suggested that the proteins from the CNR gene cluster are enormously diversified by unique mechanisms. The localization of CNR1 protein at the synapse and the diversity of CNRs led us to the hypothesis that gene regulation of the CNR family dictates the formation and reorganization of synaptic connections in the nervous system.

Early identification of impaired myocardial reperfusion with serial assessment of ST segments after percutaneous transluminal coronary angioplasty during acute myocardial infarction

To evaluate the relation between ST-segment analysis and microvascular reperfusion in patients with acute myocardial infarction (AMI), we studied 51 patients with first AMI who were successfully treated by percutaneous transluminal coronary angioplasty (PTCA). The lead showing the greatest ST-segment elevation on the 12-lead electrocardiogram (ECG) was serially investigated until 24 hours after PTCA. Successful reperfusion was determined by technetium-99m tetrofosmin single-photon emission computed tomography. Impaired reperfusion (group 1: < 4 change in the sum of the defect score from before to immediately after PTCA) was observed in 24 patients, and successful reperfusion (group 2) was observed in 27 patients. Although ST-segment elevation was reduced significantly at 30 minutes after PTCA in group 2 (2.2 +/- 1.4 to 1.7 +/- 1.3 mm, p = 0.01), there was no significant change in group 1 (1.9 +/- 1.9 to 2.4 +/- 1.7 mm). Ten of 14 patients (71%) with persistent ST-segment elevation (DeltaST > 0 mm change in ST segment from before to 30 minutes after PTCA > 0) were in group 1, whereas 23 of 37 patients (62%) with ST-segment resolution (DeltaST < or = 0) were in group 2. The sensitivity and specificity of persistent ST-segment elevation for predicting impaired microvascular reperfusion were 42% and 85%, respectively. Thus, persistent ST-segment elevation 30 minutes after primary PTCA was a highly specific electrocardiographic marker of impaired reperfusion in patients with AMI.

Administration of superantigens protects mice from lethal Listeria monocytogenes infection by enhancing cytotoxic T cells

Superantigens stimulate T-cell-receptor Vbeta-selective T-cell proliferation accompanying the release of cytokines, which may eventually protect the host from microbial infections. We investigated here whether superantigens can rescue the host from lethal bacterial infection. Mice were pretreated with Staphylococcus aureus enterotoxin B (SEB) 1 and 2 days before bacterial infection, and the mortality of infected mice was assessed. SEB pretreatment protected mice from lethal infection with Listeria monocytogenes but not from lethal infection with Streptococcus pyogenes. This enhanced protection was also observed upon pretreatment with recombinant streptococcal pyrogenic exotoxin A. Furthermore, L. monocytogenes-specific delayed-type hypersensitivity (DTH) due to type 1 helper T (Th1) cells and the cytotoxicity of CD8(+) T cells were significantly enhanced after SEB administration and bacterial infection. Depletion of either CD4(+) T cells or CD8(+) T cells in SEB-pretreated mice completely abolished this protection. This phenomenon was ascribed to the elimination of L. monocytogenes-specific CD8(+) cytotoxic T lymphocytes (CTL). It was found that CD4(+) T cells contributed to the induction of the CTL populations. Furthermore, SEB pretreatment of heat-killed L. monocytogenes-immunized mice enhanced the protection from challenge of L. monocytogenes. Taken together, these results indicated that administrations of superantigens protected mice from infection with L. monocytogenes, which was dependent on the enhanced L. monocytogenes-specific CTL activity in the presence of CD4(+) T cells, and superantigens exhibited adjuvant activity in the immunization against intracellular pathogens.

Evaluation of image quality and spatial resolution of low-dose high-pitch multidetector-row helical high-resolution CT in 11 autopsy lungs and a wire phantom

PURPOSE

The aim of this study was to evaluate whether low-dose high-pitch (6:1) multidetector-row helical high-resolution CT is appropriate for the evaluation of various pulmonary abnormalities, including faint opacities.

METHODS

Eleven autopsy lungs were scanned with a multidetector-row CT scanner using 2.5 mm x 4 beam collimation, effective slice thickness 3 mm, 6:1 pitch, 0.8 second gantry rotation speed, 20 cm Display FOV, high spatial frequency (bone) algorithm, and various radiation doses (120 kVp; 160, 80, 40, 24, and 8 mAs). The image quality of each CT set was assessed as adequate or inadequate for diagnosis by two independent observers. In addition, a wire phantom was scanned with the same parameters in order to describe the MTF curves.

RESULTS

There was excellent agreement between the observers for the evaluation of image quality (kappa statistic, 0.84). The ratio of images evaluated as inadequate for 8 mAs and 24 mAs was significantly higher than that for 160, 80, and 40 mAs (p<0.01: chi-square test). MTF curves of both 8 and 24 mAs were significantly inferior to those of 40, 80, and 160 mAs (p<0.0 1, Friedman test), while the MTF curve of 40 mAs was relatively inferior to that of 160 mAs (p<0.05, Friedman test).

CONCLUSION

More than 40 mAs in combination with 120 kVp is preferable for the evaluation of details of lung parenchyma by high-pitch. multidetector-row helical high-resolution CT.

Pulmonary involvement in primary Sjögren's syndrome: spectrum of pulmonary abnormalities and computed tomography findings in 60 patients

The purpose of this study was to describe the high-resolution computed tomography (HRCT) findings of pulmonary involvement in primary Sjögren's syndrome. The study included 60 patients who met the diagnostic criteria for primary Sjögren's syndrome. The authors retrospectively reviewed the presence, extent, and distribution of various HRCT findings. Results showed that the most common HRCT findings were areas with ground-glass attenuation (92%), followed by subpleural small nodules (78%), non-septal linear opacity (75%), interlobular septal thickening (55%), bronchiectasis (38%), and cysts (30%).

High-resolution CT using multidetector CT equipment: evaluation of image quality in 11 cadaveric lungs and a phantom

OBJECTIVE

The aim of this study was to evaluate the image quality and diagnostic efficacy of multidetector high-resolution CT (HRCT) by comparing it with single-detector HRCT and by comparing the noise and artifact of multidetector HRCT images with a phantom.

SUBJECTS AND METHODS

Multidetector HRCT with six parameters and single-detector HRCT were performed on cadaveric lungs. The image quality and diagnostic efficacy of multidetector HRCT were evaluated in comparison with those of single-detector HRCT. A phantom was scanned, and image artifact and noise were investigated.

RESULTS

. The image quality of multidetector HRCT with axial 1.25 mm x 4i (four images per gantry rotation) mode was equal to that of single-detector HRCT. The image quality of multidetector HRCT with other modes was worse than that on single-detector HRCT. The diagnostic efficacy of multidetector HRCT with high-quality mode (pitch, 3:1) and axial mode was equal to that of single-detector HRCT. The diagnostic efficacy on multidetector HRCT with high-speed mode (pitch, 6:1) was worse than that on single-detector HRCT. In the phantom study, images made in high-speed mode had strong artifacts. Noise in the axial mode was milder than that in high-speed mode but more severe than that in high-quality mode.

CONCLUSION

The image quality of axial HRCT with multidetector CT is equal to that on single-detector HRCT. Axial HRCT with multidetector CT is appropriate for evaluating subtle lung abnormalities, but high-speed mode is unsuitable. Using the high-quality mode degrades image quality but is still worthwhile.

Fba, a novel fibronectin-binding protein from Streptococcus pyogenes, promotes bacterial entry into epithelial cells, and the fba gene is positively transcribed under the Mga regulator

In infection by Streptococcus pyogenes, fibronectin (Fn)-binding proteins play important roles as adhesins and invasins. Here, we present a novel Fn-binding protein of S. pyogenes that exhibits a low similarity to other Fn-binding proteins reported. After searching the Oklahoma Streptococcal Genome Sequencing Database for open reading frames (ORFs) with an LPXTG motif, nine ORFs were found among those recognized as putative surface proteins, and one of them was designated as Fba. The fba gene was found in M types 1, 2, 4, 22, 28 and 49 of S. pyogenes, but not in other serotypes or groups of streptococci. Fba, a 37.8 kDa protein, possesses three or four proline-rich repeat domains and exhibits a high homology to FnBPA, the Fn-binding protein of Staphylococcus aureus. Recombinant Fba exhibited a strong binding ability to Fn. In addition, Fba-deficient mutants showed diminished invasive capabilities to HEp-2 cells and low mortality in mice following skin infection. The fba gene was located downstream of the mga regulon and analysis using an mga-inactivated mutant revealed that it was transcribed under the control of the Mga regulator. These results indicate that Fba is a novel protein and one of the important virulence factors of S. pyogenes.

Three-dimensional flow velocity quantification of Freestyle aortic stentless bioprosthesis by magnetic resonance imaging: surgical consideration

The characteristics in flow dynamics of stentless bioprosthetic valve implanted in aortic position has been reported using Doppler echocardiography and beneficial results have been demonstrated in patients. Because some disturbed flow characteristics were seen clinically with existence of pressure gradient, the nature of flow-velocity characteristics was evaluated in patients receiving Freestyle stentless aortic bioprosthesis using new three-dimensional MRI method. In 19 patients after AVR with Freestyle bioprosthesis, flow-velocity study was conducted using velocity-encoding phase-contrast magnetic resonance imaging (MRI). Three-dimensional flow profiles were reconstructed. The implantation techniques were subcoronary (SC) in 10, root inclusion (Incl) in 6, and full root (FR) in 3 patients. These results were compared to 4 pts with stented bioprosthesis and 4 healthy volunteers. In 3-D flow velocity profiles, there were variations from almost normal pattern to some disturbed flow pattern. All patients of FR showed the parabolic flow pattern nearly equal to normal subjects. Over half of the patients with SC and Incl showed disturbed flow pattern with increased pressure gradient. Although hemodynamically acceptable, Freestyle aortic bioprosthesis showed some degree of flow disturbance in subcoronary or inclusion method with increased transvalvular velocity that may cause late problems, and these findings evaluated by 3-D method should be implicated in surgical consideration.

Two starch-branching-enzyme isoforms occur in different fractions of developing seeds of kidney bean

The nature and enzymic properties of starch-branching enzyme (SBE) are two of the dominant factors influencing the fine structure of starch. To understand the role of this enzyme's activity in the formation of starch in kidney bean (Phaseolus vulgaris L.), a study was undertaken to identify the major SBE sequences expressed during seed development and to characterize the enzymic properties of the coded recombinant enzymes. Two SBE cDNA species (designated pvsbe2 and pvsbe1) that displayed significant similarity (more than 70%) to other family A and B SBEs respectively were isolated. Northern blot analysis revealed that pvsbe1 and pvsbe2 were differentially expressed during seed development. pvsbe2 showed maximum steady-state transcript levels at the mid-stage of seed maturation, whereas pvsbe1 reached peak levels at a later stage. Western blot analysis with antisera raised against both recombinant proteins (rPvSBE1 and rPvSBE2) showed that these two SBEs were located in different amyloplast fractions of developing seeds of kidney bean. PvSBE2 was present in the soluble fraction, whereas PvSBE1 was associated with the starch granule fraction. The differences in location suggest that these two SBE isoenzymes have different roles in amylopectin synthesis in kidney bean seeds. rPvSBE1 and rPvSBE2 were purified from Escherichia coli and their kinetic properties were determined. The affinity of rPvSBE2 for amylose (K(m) 1.27 mg/ml) was lower than that of rPvSBE1 (0.46 mg/ml). The activity of rPvSBE2 was stimulated more than 3-fold in the presence of 0.3 M citrate, whereas rPvSBE1 activity was not affected. The implications of the enzymic properties and the distribution of SBEs and amylopectin structure are discussed.

Biochemical and genetic characterization of serologically untypable Streptococcus mutans strains isolated from patients with bacteremia

Four out of 522 streptococcal isolates from the peripheral blood of patients with bacteremia exhibited typical properties of Streptococcus mutans in terms of sucrose-dependent adhesion, expression of glucosyltransferases, fermentation profiles of sugars, the presence of surface protein antigen, and DNA-DNA hybridization. Two strains were determined as serotype f and e by immunodiffusion, whereas the other two isolates did not react with the specific antiserum to S. mutans serotype c. e. or f of the eight different serotypes of mutans streptococci. The latter two untypable isolates, however, expressed a new antigenic determinant that was different from serotype c/e/f specificity as revealed by immunodiffusion. Analysis of the cell wall polysaccharides revealed very low contents of glucose in the untypable isolates. Furthermore, Southern blot analysis demonstrated that the untypable strains lacked at least one gene corresponding to a glucose-adding enzyme. These results indicate that the serologically untypable nature is due to the loss of glucosidic residue from the serotype-specific polysaccharide antigens of S. mutans.

TIMI frame count immediately after primary coronary angioplasty as a predictor of functional recovery in patients with TIMI 3 reperfused acute myocardial infarction

OBJECTIVES

The purpose of this study was to evaluate whether higher coronary blood flow, estimated by the corrected Thrombolysis In Myocardial Infarction (TIMI) frame count (CTFC), is related to better functional and clinical outcome after successful percutaneous transluminal coronary angioplasty (PTCA) in patients with acute myocardial infarction (AMI).

BACKGROUND

Experimental studies have found that functional recovery of the infarcted myocardium was associated with increased blood flow (reactive hyperemia) to the infarcted bed shortly after reperfusion.

METHODS

We measured CTFC immediately after successful (TIMI 3) primary PTCA in 104 consecutive patients with their first AMI. Wall motion score index (WMSI) and the presence of pericardial effusion were assessed by two-dimensional echocardiography before and one month after PTCA.

RESULTS

The patients were divided into two groups according to mean CTFC for corresponding coronary artery of the control group: TIMI 3 slow group (45 patients, 40 > CTFC > or = 23) and TIMI 3 fast group (59 patients, CTFC < 23). There were no significant differences in the baseline characteristics and WMSI before reperfusion between the two groups. Improvement of WMSI in the TIMI 3 fast group was significantly greater than that of the TIMI 3 slow group (1.33 +/- 0.52 vs. 0.60 +/- 0.34, p < 0.001). Pericardial effusion and intractable heart failure were observed more frequently in the TIMI 3 slow group than in the TIMI 3 fast group (27 vs. 10%; p < 0.05, 36 vs. 17%; p < 0.05). Corrected TIMI frame count, assessed as a continuous variable, had a significant correlation with the change in WMSI (r = 0.60, p < 0.001) after adjusting for age, gender, history of hypertension, history of diabetes, elapsed time to PTCA, collateral grade, presence of antegrade flow before PTCA and number of diseased vessels.

CONCLUSIONS

Lower CTFC of the infarct-related artery immediately after PTCA was associated with greater functional recovery; and hence, CTFC can predict clinical and functional outcome in patients with successful PTCA.

Evaluation of the general suitability of the rat for the micronucleus assay: the effect of cyclophosphamide in 14 strains

To evaluate the general suitability of the rat for the micronucleus assay, we conducted the assay in males of 14 different strains, 13 inbred (ACI, BN, BUF, COP, DRH, F344, IS, LEW, RCS, SHR, WAG, WKYO, WTC) and 1 outbred (SD), using cyclophosphamide as the test chemical. Cyclophosphamide at 0 (vehicle), 5, 10, or 20mg/kg per day was administered orally twice, 24h apart, to five rats per dosage group. Bone marrow and peripheral blood were collected 24h after the second treatment. All 14 strains showed a positive response to cyclophosphamide, with slight differences in sensitivity. We concluded that the rat is suitable for the micronucleus assay regardless of strain.

A system for computer-assisted design of stent-grafts for aortic aneurysms using 3-D morphological models

A three-dimensional model was constructed from helical CT images for abdominal aortic aneurysm (AAA) and thoracic aortic aneurysm (TAA). A stent-graft was designed and positioned endoluminally on the computer. One hundred and nine stent-grafts for 101 patients were designed by this method and deployed well in all patients. The design time was reduced from 4 to 0.5 hr.

Pitfalls in the interpretation of multidetector-row helical CT images at window width and level setting for lung parenchyma

This article describes pitfalls in the interpretation of multidetector-row helical CT (MDCT) images at the window width and level settings for lung parenchyma. On MDCT, linear artifacts, which look like black and white linear densities and are called "hurricane artifacts," radiate out from objects that have very different densities from their neighbors. For the evaluation of fine parenchymal details, a low table speed/slice collimation should be used. In fact, axial (step and shoot) scanning may be more effective for the evaluation of fine details. Since artifacts from vessels highly enhanced by contrast medium cause data blackout in the surrounding areas at high table speed/slice collimation, pulmonary parenchyma in such situations should be evaluated with unenhanced CT. Although multidetector-row helical CT is a promising tool for the evaluation of lung parenchyma, it is important to identify its shortcomings due to artifacts when interpreting images at the window width and level settings for lung parenchyma and to apply the appropriate methods for eliminating such artifacts.

Localized right ventricular morphological abnormalities detected by electron-beam computed tomography represent arrhythmogenic substrates in patients with the Brugada syndrome

AIMS

This study was designed to determine, using electron-beam CT, whether there are morphological abnormalities in patients with the Brugada syndrome and to elucidate the relationship between those abnormalities and arrhythmogenesis.

METHODS AND RESULTS

Twenty-six consecutive patients with the Brugada syndrome and 23 age- and gender-matched control subjects (controls) were evaluated for morphological abnormalities using electron beam CT. Electron beam CT demonstrated morphological abnormalities of the right ventricle in 21 (81%) of 26 patients, but in only two (9%) of 23 controls. The sites of morphological abnormalities were the right ventricular outflow tract area in 17 patients and the inferior wall of the right ventricle in four patients. Of the seven patients with monoform premature ventricular contractions recorded only in the acute phase, four of the five patients with premature ventricular contractions from the right ventricular outflow tract area had morphological abnormalities in the right ventricular outflow tract area, and the other two patients with premature ventricular contractions from the inferior wall of the right ventricle had morphological abnormalities in the inferior wall of the right ventricle.

CONCLUSION

The sites of morphological abnormalities detected by electron beam CT in patients with the Brugada syndrome were related to the origins of premature ventricular contractions recorded only in the acute phase, which may trigger ventricular fibrillation. These morphological abnormalities may be related to arrhythmogenic substrates in patients with the Brugada syndrome.

Cytochrome c-mediated caspase-9 activation triggers apoptosis in Streptococcus pyogenes-infected epithelial cells

Epithelial cells are the initial sites of host invasion by group A Streptococcus pyogenes (GAS), and their infection of epithelial cells has been suggested to induce apoptosis. However, the mechanism responsible for bacteria-host interaction and the induction of apoptosis has not been clearly understood. We demonstrate here that human pharyngeal epithelial HEp-2 cells became apoptotic with DNA fragmentation by invasion of GAS strains JRS4 (M6+, F1+) and JRS145 (M6-, F1+ mutant of JRS4), whereas apoptotic cellular changes were not observed in SAM1 (M6+, F1- mutant) or SAM2 (M6-, F1- mutant) infected HEp-2 cells. Confocal microscopy revealed that Bax translocation to mitochondria and cytochrome c release occurred after 4 h of infection. Western blot analyses showed that the amounts of Bcl-2 and Bcl-xL were decreased in the mitochondria of infected cells. In addition, we demonstrated that the release of nuclear histone from infected cells was prevented by the addition of caspase-9 inhibitor (Ac-LEHD-CHO). We conclude that the internalization of GAS in epithelial cells is necessary and sufficient for the induction of apoptosis, which is initiated by mitochondrial dysfunction, and the mechanism of GAS-induced apoptosis is clearly different from that induced by other intracellular invasive bacteria, e.g. Shigella and Salmonella species.

Major isoforms of starch branching enzymes in premature seeds of kidney bean (Phaseolus vulgaris L.)

Developing seeds of the kidney bean (Phaseolus vulgaris L.) contain several isoforms of starch branching enzymes. Two of them, KBE1 and KBE2, which are the major forms in the premature seeds, were purified as a single band of protein on SDS-PAGE and native PAGE by chromatographies on DEAE-Sepharose, Bio-Gel P-200, and amylose-binding Sepharose 6B. The enzymes had similar pH optimum (7.0), pH stability (7.0-9.5), temperature optimum (25-30 degrees C), and temperature stability (up to 40 degrees C). Additionally, both were inhibited by various divalent metal ions and activated by citrate. Finally, though their N-terminal amino acid sequences were identical, their molecular masses and affinities for amylose differed; 80 kDa and 1.27 mM for KBE1 and 77 kDa and 0.74 mM for KBE2.

Intraductal papillary-mucinous tumors of the pancreas: differential diagnosis between benign and malignant tumors by endoscopic ultrasonography

OBJECTIVES

Recently, intraductal papillary-mucinous tumor (IPMT) of the pancreas has increasingly been recognized. However, differential diagnosis between benign and malignant IPMT is often difficult using conventional imaging modalities. The purpose of this study was to retrospectively investigate the value of endoscopic ultrasonography (EUS) for differentiating malignant from benign IPMT.

METHODS

A total of 51 patients with IPMT were preoperatively examined by EUS. The endosonograhic findings were compared with histopathological findings of the resected specimens.

RESULTS

In main duct type IPMT, the diameter of the main pancreatic duct (MPD) was > or =10 mm in seven of the eight malignant tumors, compared with two of the seven benign tumors (p < 0.05). In branch duct type IPMT, three of the four large tumors (>40 mm) with irregular thick septa were malignant lesions. In both main duct type IPMT and branch duct IPMT, eight patients had large mural nodules (>10 mm); seven of the eight tumors were malignant and one of the eight tumors was benign. When the tumor was diagnosed as malignant according to above three findings, EUS was able to differentiate between malignant and benign IPMT with an accuracy of 86%.

CONCLUSIONS

Main duct type tumors with > or =10 mm dilated MPD, branch duct type tumors (>40 mm) with irregular septa, and large mural nodules (>10 mm) strongly suggest malignancy on EUS. EUS would be a useful modality for differentiating between benign and malignant IPMT.

Invasive and Noninvasive Thymoma: Distinctive CT Features

PURPOSE

The purpose of this work was to evaluate the CT features of thymoma and to determine the most helpful findings in differentiating invasive from noninvasive thymoma.

METHOD

The CT scans from 27 patients with invasive thymoma and 23 with noninvasive thymoma were independently assessed by two observers without knowledge of their invasiveness. The presence and distribution of various CT findings were independently analyzed.

RESULTS

Invasive thymomas were more likely to have lobulated (16/27, 59%) or irregular (6/27, 22%) contours than noninvasive thymomas (8/23, 35% and 1.5/23, 6%, respectively) (p < 0.05). Invasive thymomas had a higher prevalence of low attenuation areas within the tumor (16/27, 60%) than noninvasive thymomas (5/23, 22%) (p < 0.001) as well as foci of calcification (14.5/27, 54% vs. 6/23, 26%; p < 0.01).

CONCLUSION

The presence of lobulated or irregular contour, areas of low attenuation, and multifocal calcification is suggestive of invasive thymoma.

[Pseudo-disc-pits.macular syndrome]

BACKGROUND

Optical coherence tomography(OCT) permits the noninvasive analysis of cross-sectional tomograms of ocular tissue in vivo.

CASE

A 67-year-old woman presented with abnormal feeling in the left eye. An ophthalmoscopic examination revealed retinal edema in the macular vascular arcades and radial folds on the fovea. Optic disc pits were not demonstrated ophthalmoscopically or by fluorescein angiography(FAG). OCT disclosed separations in the inner and outer layers of the edematous retina, retinal detachment on the fovea, and cystic schisis(pseudo-pits) beneath the inner limiting membrane of the disc which seemed to be connected with the separation of the inner layers of the retina.

CONCLUSION

OCT demonstrated cystic schisis-like pits(pseudo-pits) which were not recognized ophthalmoscopically or by FAG, and the cystic schisis seemed to communicate with the inner separation of the retina. Therefore, we prefer to call such cases pseudo-disc-pits macular syndrome instead of optic disc pit macular syndrome.

Specific antibodies to Porphyromonas gingivalis Lys-gingipain by DNA vaccination inhibit bacterial binding to hemoglobin and protect mice from infection

Lys-gingipain (KGP), a lysine-specific cysteine proteinase, is one of the major virulence factors of Porphyromonas gingivalis. Here we examined the involvement of the catalytic domain of KGP (KGP(cd)) in hemoglobin binding by P. gingivalis, using a specific immunoglobulin G (IgG) elicited by the administration of plasmid DNA encoding KGP(cd) or the catalytic domain of Arg-gingipain (RGP(cd)). The pSeq2A/kgp(cd) and pSeq2B/rgp(cd) plasmids were constructed by the ligation of kgp(cd) and rgp(cd) DNA fragments, respectively. Female BALB/c mice were immunized with each of these plasmids. pSeq2A/kgp(cd) elicited a strong response to recombinant KGP(cd) (rKGP(cd)), as well as to comparably produced rRGP(cd)-reactive antibodies. The serum antibodies elicited by pSecTag2B/rgp(cd) also cross-reacted with rKGP(cd) as well as rRGP(cd). Anti-KGP(cd) IgG significantly inhibited hemoglobin binding by P. gingivalis. Furthermore, the inhibition of hemoglobin binding was markedly enhanced by a combination of anti-KGP(cd) and anti-fimbriae. Anti-RGP(cd) IgG showed a negligible inhibitory effect, while both anti-KGP(cd) and anti-RGP(cd) IgGs showed significant inhibitory effects on Lys- and Arg-specific proteolytic activities and on the growth of P. gingivalis under iron-restricted conditions where supplemented hemoglobin was the sole iron source. Immunized mice were challenged by intraperitoneal inoculation with P. gingivalis. All nonimmunized mice died within 72 h; however, vaccination with pSeq2A/kgp(cd) and pSeq2B/rgp(cd) prevented inflammatory responses and prolonged the survival rate of immunized mice by 43 and 27%, respectively. These results suggest that KGP(cd) acts as a hemoglobin-binding protein and can also be useful as an immunogen inducing a protective response to P. gingivalis infection.

Successful surgical treatment for implanted intraperitoneal metastases of hepatocellular carcinoma

We report here two patients with hepatocellular carcinoma who experienced implanted metastases in the abdominal cavity after hepatectomy or microwave coagulo-necrotic therapy. Hepatic resection and microwave coagulo-necrotic therapy were successful for these tumors, and the postoperative status was satisfactory in both patients. Implanted metastases were discovered in the abdominal cavity of each of these two patients 6 months after surgery. It is necessary to look not only for the presence of liver metastasis but also for the recurrence of the tumor in the abdominal cavity during the follow-up period. Generally, surgical resection for intraabdominal implanted tumors arising from any other abdominal organs is not indicated for improving the patient's quality of life. However, resection of metastatic tumors that occur in the abdominal cavity, arising from hepatocellular carcinoma may be of value in improving patient survival.

Pulmonary involvement in mixed connective tissue disease: high-resolution CT findings in 41 patients

The objective of this study was to describe the pulmonary abnormalities on high-resolution computed tomography (CT) in patients with mixed connective tissue disease (MCTD). The study included 41 patients who met the diagnostic criteria for MCTD and showed abnormal findings on high-resolution CT. The presence, extent, and distribution of various high-resolution CT findings were evaluated. The predominant abnormalities included areas of ground-glass attenuation (n = 41), subpleural micronodules (n = 40), and nonseptal linear opacities (n = 32). Other common findings included peripheral predominance (n = 40), lower lobe predominance (n = 39), intralobular reticular opacities (n = 25), architectural distortion (n = 20), and traction bronchiectasis (n = 18). Less common findings included honeycombing, ill-defined centrilobular nodules, airspace consolidation, interlobular septal thickening, thickening of bronchovascular bundles, bronchial wall thickening, bronchiectasis, and emphysema. Pulmonary involvement of MCTD is characterized by the presence of ground-glass attenuation, nonseptal linear opacities, and peripheral and lower lobe predominance. Ill-defined centrilobular opacities were uncommonly seen.