Radiomics analysis for differentiating of cervical lymphadenopathy between cancer of unknown primary and malignant lymphoma on unenhanced computed tomography

To investigate the usefulness of texture analysis to discriminate between cervical lymph node (LN) metastasis from cancer of unknown primary (CUP) and cervical LN involvement of malignant lymphoma (ML) on unenhanced computed tomography (CT). Cervical LN metastases in 17 patients with CUP and cervical LN involvement in 17 patients with ML were assessed by ¹⁸F-FDG PET/CT. The texture features were obtained in the total cross-sectional area (CSA) of the targeted LN, following the contour of the largest cervical LN on unenhanced CT. Values for the max standardized uptake value (SUVmax) and the mean SUV value (SUVmean), and 34 texture features were compared using a Mann-Whitney U test. The diagnostic accuracy and area under the curve (AUC) of the combination of the texture features were evaluated by support vector machine (SVM) with nested cross-validation. The SUVmax and SUVmean did not differ significantly between cervical LN metastases from CUP and cervical LN involvement from ML. However, significant differences of 9 texture features of the total CSA were observed (p = 0.001 - 0.05). The best AUC value of 0.851 for the texture feature of the total CSA were obtained from the correlation in the gray-level co-occurrence matrix features. SVM had the best AUC and diagnostic accuracy of 0.930 and 84.8%. Radiomics analysis appears to be useful for differentiating cervical LN metastasis from CUP and cervical LN involvement of ML on unenhanced CT.

CT radiomics analysis of lung cancers: Differentiation of squamous cell carcinoma from adenocarcinoma, a correlative study with FDG uptake

BACKGROUND AND PURPOSE

Pulmonary squamous cell carcinoma (SCC) was reported to have significantly higher histogram_kurtosis obtained by unenhanced computed tomography (CT) and a greater maximum standardized uptake value (SUVmax) determined by ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG-PET/CT) than pulmonary adenocarcinoma (AD). The first study aim was to investigate whether CT radiomics features could differentiate SCC from AD. The second aim was to investigate correlations between CT radiomics features and SUVmax.

MATERIALS AND METHODS

Forty solid lung tumors < 3 cm in diameter pathologically proven to be SCC (n = 18) or AD (n = 22) were included. The SUVmax was determined by ¹⁸F-FDG-PET/CT and 42 CT radiomics features were obtained from unenhanced CT. A Mann-Whitney U test was used to compare the SUVmax and each CT radiomics feature to differentiate SCC from AD. The area under the curve (AUC) was calculated from receiver operating characteristic (ROC) analysis. A binary logistic regression analysis was performed for a combination of SUVmax with each CT radiomics feature. A Spearman rank correlation analysis was performed to determine correlations between SUVmax and CT radiomics features.

RESULTS

Twenty-six of 42 CT radiomics features were significantly different between groups. The best AUC of the CT radiomics features was 0.81 for both the GLRLM_SRHGE and GLZLM_HGZE. The AUC value improved when the shape_sphericity feature was combined with SUVmax (AUC = 0.92). The CT radiomics features exhibiting strongest correlations with the SUVmax were different in both AD and SCC groups.

CONCLUSION

CT radiomics features correlated with tumor structural characteristics of SCC and AD, and were closely related to metabolic information from FDG-PET/CT.

Analysis of bronchoalveolar lavage samples collected from 30 patients with drug-induced pneumonitis

BACKGROUND

Drug-induced pneumonitis is a disease encountered by pulmonologists in the clinical setting. The diagnosis generally considers the patient's clinical course and the results of peripheral blood tests, radiological examinations, and often bronchoscopic examinations. However, few studies have reported the association between radiological patterns such as ground-glass opacity (GGO) or consolidation, and bronchoalveolar lavage fluid (BALF) cell fractions. This study aimed to clarify this association.

METHODS

Patients with a Naranjo's score of probable or definite were enrolled, and all 30 patients were categorized under probable. Data such as patient background, blood examination results, radiological findings, and BALF cell fractions were retrospectively collected. The association between BALF cell fractions and other factors such as chest computed tomography (CT) findings was evaluated.

RESULTS

The most common radiological finding in patients with lymphocyte-dominant BALF was GGO, with only one patient exhibiting consolidation. However, patients with eosinophil-dominant BALF were more likely to have consolidation; only three cases showed crazy paving and one showed GGO. In addition, patients with a GGO-dominant pattern on CT had an increased lymphocyte fraction of 41.0%; those with a consolidation-dominant pattern showed a relatively high eosinophil fraction of 5.2%; and those with a crazy paving pattern showed elevated eosinophil and neutrophil fractions of 19.1% and 9.9%, respectively.

CONCLUSIONS

In this study, a remarkable difference in radiological findings was observed among different BALF patterns.

Effects of Sodium-Glucose Cotransporter 2 Inhibition on Glucose Metabolism, Liver Function, Ascites, and Hemodynamics in a Mouse Model of Nonalcoholic Steatohepatitis and Type 2 Diabetes

Many blood glucose-lowering drugs cannot be used once patients with type 2 diabetes (T2D) and nonalcoholic fatty liver disease develop nonalcoholic steatohepatitis (NASH). Therefore, such patients often require insulin treatment. We aimed to determine the effect of sodium-glucose cotransporter 2 inhibitor (SGLT2i) dapagliflozin monotherapy on glucose metabolism in a mouse model of NASH/T2D, with a focus on its diuretic effects. To imitate ascites and to determine its severity by imaging, meglumine sodium amidotrizoate (MSA) was infused into the abdominal cavities of mice. The reduction in ascites induced by dapagliflozin was compared with that induced by furosemide using microcomputed tomography. The effects of each drug on hemodynamics were also compared. A dapagliflozin-related improvement in glucose tolerance was achieved in mice fed a high-fat diet (HFD) or an HFD + methionine-and-choline-deficient diet (MCDD). In dapagliflozin-treated NASH mice, hypoglycemia was not identified during 24-hour casual blood glucose monitoring. In the dapagliflozin and furosemide-treated groups, the time taken for the resolution of artificial ascites was significantly shorter than in the untreated group, and there were no significant differences between these groups. Furosemide significantly reduced the blood pressure and significantly increased the heart rate of the mice. Dapagliflozin caused a mild decrease in systolic, but not diastolic blood pressure, and the heart rate and circulating catecholamine and renin-aldosterone concentrations were unaffected. Dapagliflozin treatment improved glycemic control in the NASH mice versus untreated mice. Thus, dapagliflozin had a prompt diuretic effect but did not adversely affect the hemodynamics of mice with NASH and T2D. Therefore, it may be useful for the treatment of patients with both T2D and liver cirrhosis.

Strain measurement on four-dimensional dynamic-ventilation CT: quantitative analysis of abnormal respiratory deformation of the lung in COPD

Purpose

Strain measurement is frequently used to assess myocardial motion in cardiac imaging. This study aimed to apply strain measurement to pulmonary motion observed by four-dimensional dynamic-ventilation computed tomography (CT) and to clarify motion abnormality in COPD.

Materials and methods

Thirty-two smokers, including ten with COPD, underwent dynamic-ventilation CT during spontaneous breathing. CT data were continuously reconstructed every 0.5 seconds. In the series of images obtained by dynamic-ventilation CT, five expiratory frames were identified starting from the peak inspiratory frame (first expiratory frame) and ending with the fifth expiratory frame. Strain measurement of the scanned lung was performed using research software that was originally developed for cardiac strain measurement and modified for assessing deformation of the lung. The measured strain values were divided by the change in mean lung density to adjust for the degree of expiration. Spearman’s rank correlation analysis was used to evaluate associations between the adjusted strain measurements and various spirometric values.

Results

The adjusted strain measurement was negatively correlated with FEV₁/FVC (ρ=−0.52, P<0.01), maximum mid-expiratory flow (ρ=−0.59, P<0.001), and peak expiratory flow (ρ=−0.48, P<0.01), suggesting that abnormal deformation of lung motion is related to various patterns of expiratory airflow limitation.

Conclusion

Abnormal deformation of lung motion exists in COPD patients and can be quantitatively assessed by strain measurement using dynamic-ventilation CT. This technique can be expanded to dynamic-ventilation CT in patients with various lung and airway diseases that cause abnormal pulmonary motion.

Association of Focal Radiation Dose Adjusted on Cross Sections with Subsolid Nodule Visibility and Quantification on Computed Tomography Images Using AIDR 3D: Comparison Among Scanning at 84, 42, and 7 mAs

RATIONALE AND OBJECTIVES

The objectives of this study were to compare the visibility and quantification of subsolid nodules (SSNs) on computed tomography (CT) using adaptive iterative dose reduction using three-dimensional processing between 7 and 42 mAs and to assess the association of size-specific dose estimate (SSDE) with relative measured value change between 7 and 84 mAs (RMVC_7-84) and relative measured value change between 42 and 84 mAs (RMVC_42-84).

MATERIALS AND METHODS

As a Japanese multicenter research project (Area-detector Computed Tomography for the Investigation of Thoracic Diseases [ACTIve] study), 50 subjects underwent chest CT with 120 kV, 0.35 second per location and three tube currents: 240 mA (84 mAs), 120 mA (42 mAs), and 20 mA (7 mAs). Axial CT images were reconstructed using adaptive iterative dose reduction using three-dimensional processing. SSN visibility was assessed with three grades (1, obscure, to 3, definitely visible) using CT at 84 mAs as reference standard and compared between 7 and 42 mAs using t test. Dimension, mean CT density, and particular SSDE to the nodular center of 71 SSNs and volume of 58 SSNs (diameter >5 mm) were measured. Measured values (MVs) were compared using Wilcoxon signed-rank tests among CTs at three doses. Pearson correlation analyses were performed to assess the association of SSDE with RMVC_7-84: 100 × (MV at 7 mAs - MV at 84 mAs)/MV at 84 mAs and RMVC_42-84.

RESULTS

SSN visibilities were similar between 7 and 42 mAs (2.76 ± 0.45 vs 2.78 ± 0.40) (P = .67). For larger SSNs (>8 mm), MVs were similar among CTs at three doses (P > .05). For smaller SSNs (<8 mm), dimensions and volumes on CT at 7 mAs were larger and the mean CT density was smaller than 42 and 84 mAs, and SSDE had mild negative correlations with RMVC_7-84 (P < .05).

CONCLUSIONS

Comparable quantification was demonstrated irrespective of doses for larger SSNs. For smaller SSNs, nodular exaggerating effect associated with decreased SSDE on CT at 7 mAs compared to 84 mAs could result in comparable visibilities to CT at 42 mAs.

MRI findings and demographics of elastofibroma dorsi: assessment of diffusion-weighted imaging and contrast enhancement patterns

Background Elastofibroma dorsi is a rare pseudotumoral lesion. Thus, there is no report of magnetic resonance imaging (MRI) findings that investigates multiple patients particularly with respect to diffusion-weighted imaging (DWI) findings and contrast enhancement patterns. Purpose To describe the imaging findings of elastofibroma on MRI, particularly DWI findings and contrast enhancement patterns, and to further investigate patient demographics. Material and Methods Forty-four patients with elastofibroma that underwent MRI were enrolled in this retrospective study. All images were evaluated by two radiologists to visually assess the signal intensity for each sequence. Enhanced elastofibromas were classified into four categories to assess the enhancement pattern. Differences in gender and laterality were also assessed statistically. Results An equal number of men and women were included (n = 22 each). There was no significant difference in laterality ( P = 0.783). All lesions (73 lesions) had low signal intensity on both T1-weighted (T1W) and T2-weighted (T2W) images: heterogeneous in 56, homogeneous in 17. None of the 41 lesions with DWI had true abnormal diffusion restriction. The average ADC value was 1.36 × 10^-3 ± 0.29 mm²/s. All 31 lesions that had contrast-enhanced MRI were classified according to enhancement pattern: homogeneous (three lesions, 9.7%); heterogeneous (15 lesions, 48.4%); streak-like (three lesions, 9.7%); and rim-like (ten lesions, 32.2%). Conclusion There were no statistically significant differences in gender or laterality. Elastofibroma showed homogeneous to heterogeneous low signal intensity on T1W and T2W images. No lesion showed abnormal diffusion restriction, and all lesions demonstrated enhancement on MRI.

Hyperinflated lungs compress the heart during expiration in COPD patients: a new finding on dynamic-ventilation computed tomography

Purpose

The aims of this study were to evaluate dynamic changes in heart size during the respiratory cycle using four-dimensional computed tomography (CT) and to understand the relationship of these changes to airflow limitation in smokers.

Materials and methods

A total of 31 smokers, including 13 with COPD, underwent four-dimensional dynamic-ventilation CT during regular breathing. CT data were continuously reconstructed every 0.5 s, including maximum cross-sectional area (CSA) of the heart and mean lung density (MLD). Concordance between the cardiac CSA and MLD time curves was expressed by cross-correlation coefficients. The CT-based cardiothoracic ratio at inspiration and expiration was also calculated. Comparisons of the CT indices between COPD patients and non-COPD smokers were made using the Mann–Whitney test. Spearman rank correlation analysis was used to evaluate associations between CT indices and the forced expiratory volume in 1 s (FEV_1.0) relative to the forced vital capacity (FVC).

Results

Cardiac CSA at both inspiration and expiration was significantly smaller in COPD patients than in non-COPD smokers (P<0.05). The cross-correlation coefficient between cardiac CSA and MLD during expiration significantly correlated with FEV_1.0/FVC (ρ=0.63, P<0.001), suggesting that heart size decreases during expiration in COPD patients. The change in the cardiothoracic ratio between inspiration and expiration frames was significantly smaller in COPD patients than in non-COPD smokers (P<0.01).

Conclusion

Patients with COPD have smaller heart size on dynamic-ventilation CT than non-COPD smokers and have abnormal cardiac compression during expiration.

Asynchrony in respiratory movements between the pulmonary lobes in patients with COPD: continuous measurement of lung density by 4-dimensional dynamic-ventilation CT

Purpose

Four-dimensional dynamic-ventilation CT imaging demonstrates continuous movement of the lung. The aim of this study was to assess the correlation between interlobar synchrony in lung density and spirometric values in COPD patients and smokers, by measuring the continuous changes in lung density during respiration on the dynamic-ventilation CT.

Materials and methods

Thirty-two smokers, including ten with COPD, underwent dynamic-ventilation CT during free breathing. CT data were continuously reconstructed every 0.5 sec. Mean lung density (MLD) of the five lobes (right upper [RU], right middle [RM], right lower [RL], left upper [LU], and left lower [LL]) was continuously measured by commercially available software using a fixed volume of volume of interest which was placed and tracked on a single designated point in each lobe. Concordance between the MLD time curves of six pairs of lung lobes (RU-RL, RU-RM, RM-RL, LU-LL, RU-LU, and RL-LL lobes) was expressed by cross-correlation coefficients. The relationship between these cross-correlation coefficients and the forced expiratory volume in one second/forced vital capacity (FEV_1.0/FVC) values was assessed by Spearman rank correlation analysis.

Results

In all six pairs of the pulmonary lobes, the cross-correlation coefficients of the two MLD curves were significantly positively correlated with FEV_1.0/FVC (ρ =0.60–0.73, P<0.001). The mean value of the six coefficients strongly correlated with FEV_1.0/FVC (ρ =0.80, P<0.0001).

Conclusion

The synchrony of respiratory movements between the pulmonary lobes is limited or lost in patients with more severe airflow limitation.

Continuous quantitative measurement of the proximal airway dimensions and lung density on four-dimensional dynamic-ventilation CT in smokers

Purpose

Four-dimensional dynamic-ventilation computed tomography (CT) imaging demonstrates continuous movement of the airways and lungs, which cannot be depicted with conventional CT. We aimed to investigate continuous changes in lung density and airway dimensions and to assess the correlation with spirometric values in smokers.

Materials and methods

This retrospective study was approved by the Institutional Review Board, and informed consent was waived. Twenty-one smokers including six patients with COPD underwent four-dimensional dynamic-ventilation CT during free breathing (160 mm in length). The mean lung density (MLD) of the scanned lung and luminal areas (Ai) of fixed points in the trachea and the right proximal bronchi (main bronchus, upper bronchus, bronchus intermedius, and lower bronchus) were continuously measured. Concordance between the time curve of the MLD and that of the airway Ai values was expressed by cross-correlation coefficients. The associations between these quantitative measurements and the forced expiratory volume in 1 second/forced vital capacity (FEV₁/FVC) values were assessed by Spearman’s rank correlation analysis.

Results

On the time curve for the MLD, the Δ-MLD1.05 values between the peak inspiratory frame to the later third frame (1.05 seconds later) were strongly correlated with the FEV₁/FVC (ρ=0.76, P<0.0001). The cross-correlation coefficients between the airway Ai and MLD values were significantly correlated with the FEV₁/FVC (ρ=−0.56 to −0.66, P<0.01), except for the right upper bronchus. This suggested that the synchrony between the airway and lung movement was lost in patients with severe airflow limitation.

Conclusion

Respiratory changes in the MLD and synchrony between the airway Ai and the MLD measured with dynamic-ventilation CT were correlated with patient’s spirometric values.

Bilateral duplication of the abducens nerves: an incidental finding on magnetic resonance imaging

Although anomaly of the abducens nerve, including duplication, has been reported in anatomical papers, no radiological report exists regarding a duplicated abducens nerve observed on magnetic resonance (MR) imaging. We encountered a case of bilateral duplication of the abducens nerves, which was found incidentally on MR scans from an 11-year-old boy. He did not have any symptoms of eye movement related to abducens nerve abnormality; thus, the duplication was considered to be a normal variant in this patient. Radiologists should be aware that duplication of the abducens nerve may occur and can be diagnosed on MR, particularly when diagnosing symptomatic patients or as a preoperative assessment for microsurgery of the nerve.

Automated continuous quantitative measurement of proximal airways on dynamic ventilation CT: initial experience using an ex vivo porcine lung phantom

Background

The purpose of this study was to evaluate the feasibility of continuous quantitative measurement of the proximal airways, using dynamic ventilation computed tomography (CT) and our research software.

Methods

A porcine lung that was removed during meat processing was ventilated inside a chest phantom by a negative pressure cylinder (eight times per minute). This chest phantom with imitated respiratory movement was scanned by a 320-row area-detector CT scanner for approximately 9 seconds as dynamic ventilatory scanning. Obtained volume data were reconstructed every 0.35 seconds (total 8.4 seconds with 24 frames) as three-dimensional images and stored in our research software. The software automatically traced a designated airway point in all frames and measured the cross-sectional luminal area and wall area percent (WA%). The cross-sectional luminal area and WA% of the trachea and right main bronchus (RMB) were measured for this study. Two radiologists evaluated the traceability of all measurable airway points of the trachea and RMB using a three-point scale.

Results

It was judged that the software satisfactorily traced airway points throughout the dynamic ventilation CT (mean score, 2.64 at the trachea and 2.84 at the RMB). From the maximum inspiratory frame to the maximum expiratory frame, the cross-sectional luminal area of the trachea decreased 17.7% and that of the RMB 29.0%, whereas the WA% of the trachea increased 6.6% and that of the RMB 11.1%.

Conclusion

It is feasible to measure airway dimensions automatically at designated points on dynamic ventilation CT using research software. This technique can be applied to various airway and obstructive diseases.

Negative feedback regulation of activated macrophages via Fas-mediated apoptosis

Apoptosis is a critical event for eliminating activated macrophages. Here we show that Fas-mediated apoptosis may participate in the mechanism of negative feedback regulation of activated macrophages. Cytokine-activated macrophages released high levels of nitric oxide (NO) that induced apoptosis in macrophages themselves. This NO-induced macrophage apoptosis was inhibited by a Fas-Fc chimeric molecule that binds to Fas ligand (FasL) and prevents its interaction with endogenous cell surface Fas. High levels of NO stimulated the release of the soluble form of FasL that was inhibited by a matrix metalloproteinase inhibitor KB-8301. High levels of NO also upregulated the expression of Fas mRNA in macrophages. In addition, macrophages isolated from Fas-lacking mice were resistant to NO-induced apoptosis. Finally, inhibition of apoptosis by a caspase inhibitor augmented peroxide production from activated macrophages. These findings suggest that high levels of NO released from activated macrophages may promote the Fas-mediated macrophage apoptosis that may be a negative feedback mechanism for elimination and the downregulation of activated macrophages in the vessel wall.

[Embolization of varicocele with ethanol]

Embolization with ethanol was performed in 40 varicocele patients to prevent recurrence due to collateral formation. A prescribed amount of ethanol (0.5-4 ml) was injected slowly into the testicular vein with the catheter tip as close as possible to the inguinal region. Embolization with stainless steel coils was also performed in 15 of the 40 patients. Immediately after embolization, three varicoceles were reduced in size, and 37 disappeared. Recurrence was recognized in only two patients. These patients were embolized at a proximal site above lumbar vertebra IV. Spermatic data have improved for 13 patients but not for one azoospermatic patient. Serious complications were recognized in only one patient, who received an injection of 15 ml ethanol in one dose. Therefore, we conclude that embolization with ethanol is an useful treatment for varicocele.

[Intermittent intraarterial infusion chemotherapy using a subcutaneously implanted reservoir in patients with hepatoma]

Hepatocellular carcinomas that should not be treated with transarterial embolization (TAE) were treated with intermittent intraarterial infusion chemotherapy using a subcutaneously implanted reservoir. Among 37 patients, in whom objective evaluation of the initial response was possible, 3 cases of CR, 12 of PR, 10 of NC and 12 of PD were obtained. The response rate was 40.5%. Culminate 1 year survival rates were 80.0% for responders (CR + PR), 4.5% for non-responders (NC + PD) and 35.1% as an average for all patients. The survival in responder patients was better than in non-responders (p < 0.001). To determine the role of this therapy we divided the cases into two groups by anamnesis of TAE and investigated the initial response and prognosis based on the grade of portal vein invasion in each group. In one group of 18 patients, who had not been treated with TAE, there were no relationships between the grade of portal vein invasion and the initial response and between the grade of portal vein invasion and the prognosis. In this group the initial response was better in patients whose one shot infusion chemotherapy immediately before intermittent intraarterial infusion chemotherapy had been effective than in the others. In the other group of 19 patients, who had been treated with TAE, the initial response and prognosis were better in patients with lower grades of portal vein invasion (Vp0-2) than in those with the highest grade (Vp3).

[MR-angiography of veins in the lower extremities]

Phase contrast MR-angiography (MRA) of veins in the lower extremities was performed in 10 healthy volunteers and 2 patients with deep vein thrombosis of the lower extremities. In all volunteers, MRA demonstrated bilateral large saphenous veins, femoral veins and popliteal veins. Deep veins in the leg were visualized in only 3 out of 20 legs examined, but with compression of the thigh they were visualized in 4 out of 7 legs subjected to compression. In patients with deep vein thrombosis, obstruction of the femoral veins and development of the collateral veins were clearly visualized. It is concluded that MRA may be a valuable technic for the evaluation of the veins patency in the lower extremities.

[MR angiography of the forearm--visualization of the internal dialysis shunt]

Phase contrast MR angiography (MRA) of the forearm was performed in 10 healthy volunteers and 3 patients with chronic renal failure. In all volunteers, MRA demonstrated two arteries (radial artery and ulnar artery) and several cutaneous veins. In patients with chronic renal failure, internal dialysis shunts were clearly visualized and the stenoses of the shunts which were confirmed by later DSA were also well defined. It is concluded that MRA may be a valuable technic in the evaluation of internal dialysis shunts.

[Studies on biodegradable microcapsules of anticancer drugs]

We made biodegradable microcapsules for the controlled release of an anticancer drug. The spherical capsules were designed to be infused repeatedly through an implanted angiographic catheter. The microcapsules were made by the Wurster method, and consisted of a core consisting of lactose and a shell consisting of lecithin, cholesterol, stearic acid, and polyvinylpyrrolidone. The capsules with diameters of 50 to 200 microns could be infused through a catheter. In blood plasma, the capsules absorbed water and disintegrated in 20-30 min. The amount of drug released from the microcapsules in a test of dissolution in a column could be controlled by changes in the thickness of the shell. These capsules will now be tested in rabbits with experimental tumors.

Characterization of the subunit particles of feline calicivirus

In the culture fluid from cells infected with feline calicivirus (FCV) F4 strain, the infectious and smaller non-infectious subunit particles were detected by complement fixation (CF) test after sucrose gradient centrifugation. The results of sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblot analyses confirmed the existence of the subunit particles of FCV, and showed that the infectious and subunit particles were mainly composed of 65K capsid protein. The subunit particles were further purified by ion-exchange chromatography and sucrose gradient centrifugation. The purified subunit and infectious particles had the same neutralizing epitope on 65K protein detected by immunoblot analysis with a neutralizing monoclonal antibody. Antigenic comparison between the infectious and subunit particles by the CF tests using an antiserum against heterologous strain of FCV F14 indicated that the subunit particles might have more highly conserved antigens of FCV than the infectious particles.

[Multifocal fatty infiltration of the liver: report of six cases]

Images of computed tomography (CT), ultrasonography (US), angiography and radionuclide imaging were analyzed in six cases of multifocal fatty infiltration of the liver. Histologic confirmation of fatty infiltration was obtained in one patient by percutaneous biopsy. In the remaining patients, presumptive confirmation of the diagnosis was based on the CT number in one patient and partial or complete resolution of the lesions on repeat CT scans or US in 4 patients. CT and US were performed in all six patients. CT scans demonstrated multiple round areas of low attenuation within both lobes of the liver in all cases. US studies showed hyperechoic foci in three cases and diffuse inhomogeneous hyperechogenicity in three cases. Hepatic arteriograms in five cases and liver scintigrams in four cases showed no evidence of space-occupying lesions. In all cases, the lesions completely or partially resolved in follow-up CT and US, and in four cases the lesions disappeared within two months, so follow-up examinations within about 2 months are necessary to differentiate these from liver neoplasms.

Preparation and characterization of neutralizing monoclonal antibodies to feline calicivirus

Fourteen neutralizing monoclonal antibodies (N-MoAbs) were prepared against the F4 strain of feline calicivirus (FCV), the prototype strain of FCV in Japan, and examined for their ability to neutralize FCV isolates. Neutralization-resistant variants of the F4 strain were selected under the presence of 4 individual N-MoAbs in cell culture systems and used in cross-neutralization tests and enzyme-linked immunosorbent assay with all of the 14 N-MoAbs. The results revealed the identification of at least two antigenic determinants on FCV F4: one being more broadly conserved among FCV isolates than the other. Usefulness of antigenic variants resistant to N-MoAbs for analysis of neutralization determinants on FCV was also demonstrated.

[Selective segmental sclerotherapy of the liver by transportal ethanol injection--a complete remission case of hepatocellular carcinoma]

Selective segmental sclerotherapy of the liver by transportal ethanol injection (SSS) was devised and evaluated in a case of hepatocellular carcinoma. The patient was a 72-year-old man suffering from unresectable hepatoma. Injected ethanol with an amount of 20 ml into the portal branch under occluding the portal flow by balloon catheter produced complete necrosis of the liver proportional to the injected liver segment including the tumor on CT. Because of ethanol perfusion into sinusoid level by wedge injection, its cytotoxicity maybe affected liver cells directly. In this case, there has been no evidence of inadvertent liver damage and a significant rise in the blood ethanol level. The present technique of SSS in this clinical case and our past animal experience seemed to yield the same condition as resection without surgical disadvantages and be apparently a safe method, which is suggested for clinical use for several hepatic tumors.

[Experimental and clinical studies on degradable starch microspheres (DSM) in the treatment of hepatic neoplasms]

To evaluate the effect of hepatic arterial chemotherapy combined with DSM, experimental and clinical studies were performed. Experimental study: Hemodynamic and histological changes induced by intra-arterial administration of DSM were investigated in the kidneys of rabbits. The degree of blockade of arterial blood flow was correlated with the dosage of DSM, and estimated by the angiographic change. Histological changes also depended on the dosage of DSM. Although administration of less than 6 mg DSM induced little or no histological changes, more than 15 mg of DSM induced extensive necrosis of renal tubules. Clinical study: The hepatic arterial chemotherapy combined with DSM was performed in 63 patients (hepatomas in 45 and metastatic tumors in 18). Fourteen patients (30%) showed partial or complete response. Patients with a higher degree of blockade of arterial blood flow tended to have a better response. Analysis of CT images suggested that DSM not only enhance the chemotherapeutic agents but also the ischemic effect. In conclusion, degree of blockade of arterial blood flow is controlled by the change in DSM dosage, and DSM administration combined with chemotherapeutic agents may have the potential to improve the therapeutic effect.

Fibrinolytic activity in cystic lesions of jaw bones

The fibrinolytic activity in the tissues of cystic lesions of jaw bones was investigated by the semiquantitative method of Astrup. The specimens examined were ameloblastoma (9 cases), follicular cyst (8 cases) and radicular cyst (14 cases). High fibrinolytic activity was observed in ameloblastoma, while in radicular cyst the activity was variable. It is suggested that in radicular cyst inflammatory episodes play an important role in activating local fibrinolysis, while in ameloblastoma the tissue itself has a great capacity to induce locally activated plasmin.

Analysis of 102 lesions diagnosed as "palatal tumor" in a spot diagnosis

The present report analyzes 102 pathologic conditions of the palate which had been diagnosed as "palatal tumor" in a spot diagnosis at Osaka University Dental Hospital over an 8-year period. Tumors of minor salivary glands were the most frequent (51 cases, 50%). Tumors of non-salivary gland origin numbered 22 cases (21.6%), and inflammatory and cystic lesions totalled 29 cases (28.4%). The specificity of the tumors and the tumorous lesions in the palate are discussed.