Hepatitis C virus core region: helper T cell epitopes recognized by BALB/c and C57BL/6 mice

In this study, we characterized the B cell and T cell responses to the hydrophilic portion of hepatitis C virus (HCV) core protein in two strains of mice and identified the respective antigen determinants. BALB/c (H-2d) and C57BL/6 (B6:H-2b) mice were immunized by a subcutaneous injection of recombinant HCV core protein together with Freund's complete adjuvant. The level of antibody production, as determined by ELISA, was consistently higher in BALB/c than in B6 mice. However, antibodies in sera from each strain bound to the N-terminal region of the core protein within amino acids 1 to 28 (MSTNPKPQRKIKRNTNRRPQDVKFPGGG), according to an experiment using non-overlapping peptides that covered the hydrophilic portion of HCV core protein. The T cell responses were also higher in BALB/c than in B6 mice with respect to the proliferative responses of the draining lymph node cells in vitro. By limiting dilution cultures of the draining lymph node cells in vitro repetitively stimulated with recombinant core protein, T cell clones were established from both strains of mice and characterized. The surface markers of these clones were Thy-1.2+, CD3+, TCR alpha beta+, CD4+ and CD8+. The proliferative responses were inhibited in the presence of anti-CD4 or anti-MHC class II monoclonal antibodies. The T cell lines in BALB/c mice recognized an epitope in HCV core at amino acids 72 to 91 (EGRAWAQPGYPWPLYGNEGL). The T cell lines in B6 mice recognized an epitope at amino acids 55 to 74 (RPQPRGRRQPIPKARQPEGR). Thus, mice with different MHC haplotypes recognized different non-overlapping T cell antigenic determinants of HCV core proteins.

Involvement of muscle by malignant lymphoma: MR and CT appearances

OBJECTIVE

The purpose of this study is to investigate the CT and MR findings of muscular involvement by malignant lymphoma and identify the CT and MR features that may assist in their diagnosis.

MATERIALS AND METHODS

Magnetic resonance imaging was performed on four patients (five lesions) with pathologically proven non-Hodgkin lymphoma using a 1.5 T unit (Cases 1, 2, and 4) and a 0.5 T scanner (Case 3). Computed tomography scans were carried out on three patients (Cases 1, 3, and 4).

RESULTS

The lesions that extended along muscle fascicles with preserved fat planes looking like swelling of the muscle were of slightly hyper- to isointensity relative to uninvolved muscles on T1-weighted images, of hyperintensity on T2-weighted images, and of low or isodensity on CT. Microscopically, lymphoma cells were seen clustering among normal and atrophic muscle fibers in a biopsy specimen of one patient. The lesions enhanced relatively homogeneously after Gd-DTPA injection. In three cases, vessels were coursing through the lesion on MRI and in two cases on enhanced CT.

CONCLUSION

Magnetic resonance imaging proved useful to show the extension of involvement of muscular lymphoma compared with CT. The diagnosis of infiltration of muscle by lymphoma is entertained when a lesion of relatively homogeneous intensity and density extends along the muscle fascisles without obliteration of the fat planes and especially when vessels are identified within the lesion.

Improved targeting of radiolabeled streptavidin in tumors pretargeted with biotinylated monoclonal antibodies through an avidin chase

Radiolabeled streptavidin can be accumulated in tumors pretargeted with biotinylated anti-tumor antibodies. However, circulating biotinylated antibody and endogenous biotin may interfere with the tumor targeting of streptavidin. To reduce biotinylated antibody concentration in the blood, we injected avidin before streptavidin administration. The effects of avidin administration on the biodistribution and tumor targeting of radiolabeled streptavidin were examined.

METHODS

Biotinylated anti-human colon cancer monoclonal antibody (MAb) MLS128 was injected intravenously into nude mice bearing human colon cancer xenografts for pretargeting. After intraperitoneal injection of avidin, radioiodinated streptavidin was administered and its biodistribution and tumor accumulation was investigated.

RESULTS

Radioiodinated streptavidin specifically localized in the tumor pretargeted with biotinylated antibody. Avidin preadministration accelerated the tumor uptake and blood clearance of radioiodinated streptavidin. The tumor-to-blood radioactivity ratio at 6 and 24 hr after radiolabeled streptavidin injection were 1.23 +/- 0.29 and 3.04 +/- 0.86, respectively, in mice with avidin chase (mean +/- s.d., n = 7), and 0.82 +/- 0.17 and 2.29 +/- 0.29, respectively, in those without chase (mean +/- s.d., n = 7).

CONCLUSION

Localization of radiolabeled streptavidin in tumors pretargeted with biotinylated MAb could be improved by avidin chase. This approach may be useful for tumor radioimmunoimaging and radioimmunotherapy.

[Primary hemangiopericytoma of the chest wall: a case report]

We describe a rare male case of malignant hemangiopericytoma of the chest wall. An extrapleural chest wall mass about 1.5 x 4 cm in size was detected along the right 3rd rib on a chest roentgenogram when the patient was 58 years old. The tumor did not enlarge for over 12 years thereafter. At the age of 73 years, the patient came to our hospital for chest pain after a traffic accident. A roentgenogram revealed the extrapleural tumor of the chest, which was enlarged to 8 x 12 x 7 cm, and right hemothorax. The tumor was resected together with the 3rd and 4th ribs. Light and electron microscopy and immunostaining studies led to a diagnosis of malignant hemangiopericytoma. The postoperative course was uneventful, and radiotherapy and chemotherapy were performed. The patient has been well without recurrence for 18 months after the operation. We also reviewed 9 cases of this tumor reported in Japan.

Towards fully automated genotyping: use of an X linked recessive spastic paraplegia family to test alternative analysis methods

Advances in dinucleotide-based genetic maps open possibilities for large scale genotyping at high resolution. The current rate-limiting steps in use of these dense maps is data interpretation (allele definition), data entry, and statistical calculations. We have recently reported automated allele identification methods. Here we show that a 10-cM framework map of the human X chromosome can be analyzed on two lanes of an automated sequencer per individual (10-12 loci per lane). We use this map and analysis strategy to generate allele data for an X-linked recessive spastic paraplegia family with a known PLP mutation. We analyzed 198 genotypes in a single gel and used the data to test three methods of data analysis: manual meiotic breakpoint mapping, automated concordance analysis, and whole chromosome multipoint linkage analysis. All methods pinpointed the correct location of the gene. We propose that multipoint exclusion mapping may permit valid inflation of LOD scores using the equation max LOD-(next best LOD).

Transcriptional regulation of human thyroid hormone receptor beta 1 gene expression: effect of human retinoid X receptor and identification of a transcriptional silencer region

Effects of human retinoid X receptor alpha (hRXR alpha) and its ligand, 9-cis-retinoic acid, on T3-mediated auto-regulation of hTR beta 1 gene expression were examined using a chloramphenicol acetyltransferase (CAT) reporter system, and a deletional analysis of the promoter. hRXR alpha enhanced T3-dependent CAT induction mediated through the proximal (p) TRE in a ligand (9-cis-retinoic acid) independent manner. In a gel mobility shift assay, hRXR alpha enhanced the binding of hTR beta 1 to the pTRE by the formation of hRXR alpha-hTR beta 1 heterodimers. On the other hand, hRXR alpha and 9-cis-retinoic acid did not show any effects on T3-dependent CAT induction mediated through the distal (d) TRE or the binding of hTR beta 1 to the dTRE. A four hundred-base pair (bp) fragment adjacent upstream of the dTRE showed a T3 independent suppressor effect on the function of the pTRE and dTRE. Thus, this region may be an important regulator of the T3 dependent up-regulation of the TR beta 1 gene expression which is observed only under specific conditions.

Effect of lidocaine on alpha 1-adrenoceptors in cultured neonatal rat cardiocytes

The effect of lidocaine on alpha 1-adrenoceptors in cultured neonatal rat ventricular cardiocytes was studied by binding assay. When the cells were cultured in the presence of lidocaine, the binding of (+/-)-beta-([125I]iodo-4-hydroxyphenyl)-ethyl-aminomethyl-tetralone to the cells increased in a concentration- and time-dependent manner. The effect was due to an increase in maximum binding but not due to a change in the dissociation constant for the ligand. The increased number of alpha 1-adrenoceptors returned to the control level after culturing the cells without lidocaine. The stimulating effect on the number of alpha 1-adrenoceptors of lidocaine was also observed in the presence of norepinephrine. Other class I antiarrhythmic drugs such as procainamide. disopyramide, mexiletine and flecainide increased the number of alpha 1-adrenoceptors in the cells. These results suggest that cardiac responsiveness mediated by alpha 1-adrenoceptors is increased by class I antiarrhythmic drugs.

Inhibitory effect of a conjugate between human urokinase and urinary trypsin inhibitor on tumor cell invasion in vitro

Proteolytic enzymes such as urokinase-type plasminogen activator (uPA), plasmin, and collagenase mediate proteolysis by a variety of tumor cells. uPA secreted by tumor cells can be bound to a cell surface receptor via a growth factor-like domain within the amino-terminal fragment (ATF) of the uPA molecule with high affinity. Urinary trypsin inhibitor (UTI) efficiently inhibits the soluble and the tumor cell-surface receptor-bound plasmin and subsequently reduces tumor cell invasion and the formation of metastasis. The anti-invasive effect is dependent on the anti-plasmin activity of the UTI molecule, domain II in particular. We synthesized a conjugate between ATF of human uPA and a native UTI molecule or domain II of UTI (HI-8). The effect of the conjugates (ATF.UTI or ATF.HI-8) on tumor cell invasion in vitro was investigated. ATF.UTI and ATF.HI-8 bound to U937 cells in a rapid, saturable, dose-dependent, and reversible manner. A large part of receptor-bound ATF-UTI and ATF.HI-8 remains on the cell surface for at least 5 h at 37 degrees C. Inhibition of tumor cell-surface receptor-bound plasmin by ATF.UTI and ATF.HI-8 was markedly enhanced when compared with tumor cells treated either with ATF, UTI, or HI-8. Results of a cell invasion assay showed that ATF.UTI and ATF.HI-8 is very effective at targeting HI-8 specifically to uPA receptor-expressing tumor cells, whereas tumor cells devoid of uPA receptor may be less affected by the conjugates. Our results indicate that cell surface uPA and plasmin activity is essential to the invasive process and that the conjugates exhibit plasmin inhibition to the close environment of the cell surface and subsequently inhibit the tumor cell invasion through Matrigel in an in vitro invasion assay.

Diagnostic value of Tc-99m (V) DMSA for chondrogenic tumors with positive Tc-99m HMDP uptake on bone scintigraphy

Technetium-99m (V) DMSA scintigraphy was performed in 17 patients with 37 chondrogenic tumors (13 osteochondromas, 14 enchondromas, and 10 chondrosarcomas) that had previously shown uptake of Tc-99m HMDP. Technetium-99m (V) DMSA showed high uptake by all chrondrosarcomas, but low or no uptake always indicated benign chondrogenic tumors. Technetium-99m (V) DMSA scintigraphy may be superior to Tc-99m HMDP scintigraphy for distinguishing benign and malignant chondrogenic tumors, and could also be useful for diagnosing the malignant transformation of chondrogenic tumors.

Antimetastatic effects of PSK (Krestin), a protein-bound polysaccharide obtained from basidiomycetes: an overview

PSK, a protein-bound polysaccharide obtained from cultured mycelia of Coriolus versicolor in basidiomycetes, is a biological response modifier, diverse operations of which include an antitumor action. We have previously reviewed recent research which had demonstrated that in animals, PSK has a preventive effect on chemical carcinogen-induced, radiation-induced, and spontaneously developed carcinogenesis (Kobayashi et al., Cancer Epidemiol., Biomarkers & Prev., 2: 271-276, 1993). We now focus on the effects of PSK once the progression of carcinogenesis has begun, and review what is now known of the preventive action of PSK on cancer metastasis. Recent research reports that PSK suppresses pulmonary metastasis of methylcholanthrene-induced sarcomas, human prostate cancer DU145M, and lymphatic metastasis of mouse leukemia P388, and that it has prolonged the survival period in spontaneous metastasis models. PSK also suppresses the metastasis of rat hepatoma AH60C, mouse colon cancer colon 26, and mouse leukemia RL male 1 in artificial metastasis models. PSK influences the steps of cancer metastasis in a number of ways: (a) by suppression of intravasation through the inhibition of tumor invasion, adhesion and production of cell matrix-degrading enzymes; (b) by suppression of tumor cell attachment to endothelial cells through the inhibition of tumor cell-induced platelet aggregation; (c) by suppression of tumor cell migration after extravasation through the inhibition of tumor cell motility; and (d) by suppression of tumor growth after extravasation through the inhibition of angiogenesis, the modulation of cytokine production, and the augmentation of effector cell functions. In addition, PSK has suppressed the malignant progression of mouse tumor cells through superoxide trapping.(ABSTRACT TRUNCATED AT 250 WORDS)

Impairment of syntaxin by botulinum neurotoxin C1 or antibodies inhibits acetylcholine release but not Ca2+ channel activity

The involvement of syntaxin, an omega-conotoxin-sensitive Ca2+ channel-associated protein, in acetylcholine release was studied at synapses formed between rat sympathetic neurons in culture. Transmission at these synapses involved omega-conotoxin-sensitive Ca2+ channels because a dose-dependent inhibition was observed when omega-conotoxin was bath-applied. Confocal microscope examination of immunofluorescent staining showed that syntaxin had a similar distribution to synaptic vesicle-associated membrane proteins, synaptophysin and vesicle-associated membrane protein/synaptobrevin-2, indicating that syntaxin molecules are concentrated in the presynaptic terminals. Botulinum neurotoxin C1 applied extracellularly or intracellularly into presynaptic neurons blocked synaptic transmission. Introduction of a monoclonal antibody, or polyclonal antibodies, to syntaxin into the presynaptic neuron depressed the evoked release of acetylcholine without affecting Ca2+ influx through Ca2+ channels. These results suggest that syntaxin plays an important role in release of neurotransmitter by a nerve impulse and that this mechanism is downstream of Ca2+ influx.

Urokinase-type plasminogen activator (uPA) and its receptor (CD87): a new target in tumor invasion and metastasis

Extravasation and intravasation of tumor cells in solid malignant tumors is controlled by 3 steps: 1) attachment to and interaction of tumor cells with components of the basement membrane and the extracellular matrix, 2) local proteolysis, and 3) tumor cell migration. Evidence has accumulated that different types of tumor-associated proteases, their inhibitors and receptors are involved in tumor invasion and metastasis. Four different classes of proteases are known to be correlated with the malignant phenotype: 1) Matrix metalloproteases; including collagenases, gelatinases and stromelysins. 2) Cysteine proteases; including cathepsins B and L. 3) Aspartyl protease cathepsin D. 4) Serine proteases; including plasmin and tissue-type plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA). A strong independent prognostic value (relapse-free and/or overall survival) has especially been demonstrated for uPA and its inhibitor PAI-1 in patients with cancer of the breast, ovary, stomach, esophagus, colon, lung, and kidney thus predicting the course of the cancer disease. The strong correlation between elevated uPA and/or PAI-1 values in primary cancer tissues and the malignant phenotype of cancer cells has prompted to explore new tumor biology-oriented concepts in order to suppress uPA or uPA receptor (CD87) expression or to abrogate interaction of uPA with CD87. Various very different approaches to interfere with the expression or reactivity of uPA or CD87 at the gene or protein level were successfully tested including antisense oligonucleotides, antibodies, inhibitors and recombinant or synthetic uPA and CD87 analogues.

Immunochemical characterization of neural cell adhesion molecule (NCAM), nitric oxide synthase, and neurofilament protein expression in pyloric muscle of patients with pyloric stenosis

The etiology of hypertrophic pyloric stenosis (HPS) is not known. We made an immunocytochemical examination of pyloric muscle from 18 patients with HPS and 10 controls using specific monoclonal antibodies to neural cell adhesion molecule (NCAM) as well as neurofilament protein and NADPH-diaphorase histochemistry. In HPS, bundles of hypertrophic muscle fibers expanded the circular muscle layer. The longitudinal muscle also appeared hypertrophic but to a less marked degree. The most striking difference between HPS and the control tissues was that NCAM, NADPH-diaphorase, and neurofilament protein immunoreactive fibers were absent or markedly reduced within the hypertrophied circular and longitudinal musculature. In contrast, NCAM, NADPH-diaphorase, and neurofilament protein immunoreactivity was preserved in the myenteric plexus where nerve fibers and ganglion cells were stained. The lack of expression of NCAM, NADPH-diaphorase, and neurofilament protein on nerve fibers within the circular and longitudinal muscle in patients with pyloric stenosis suggests that the smooth muscle is not innervated in this condition.

[Identification of viable myocardium using 99mTc-tetrofosmin scintigraphy--comparison with 201Tl redistribution-reinjection images]

The purpose of this study was to clarify the diagnostic value of identifying viable myocardium using 99mTc-Tetrofosmin scintigraphy. Twenty-one patients with chronic coronary artery disease were studied using 201Tl exercise myocardial scintigraphy with reinjection and 99mTc-Tetrofosmin exercise myocardial scintigraphy. All patients had a history of old myocardial infarction. For 99mTc-Tetrofosmin scintigraphy, 222 MBq of 99mTc-Tetrofosmin was injected during exercise, and exercise images were obtained 20 min thereafter. There hours later, 666 MBq of 99mTc-Tetrofosmin was injected at rest, and images were obtained 40 min and 220 min later. Myocardial viability in the 99mTc-Tetrofosmin scintigraphy was estimated as fill-in findings (FF) or over 50% of %RI uptake (%TF) in the rest image. Myocardial viability in the 201Tl scintigraphy was estimated as redistribution (RD), fill-in findings in the reinjection image (FR) or over 50% of %RI uptake in the reinjection image (% TL). Sixteen of the 21 patients (76%) who underwent 201Tl scintigraphy (RD 10, FR 3, %TL 3 cases) and 15 of the 21 patients (71%) who underwent 99mTc-Tetrofosmin scintigraphy (FF 11, %TF 4 cases) had viable myocardium in the infarcted area. A comparison between the 99mTc-Tetrofosmin rest images obtained 40 min after the injection and that of 220 min revealed no redistribution findings. The %RI uptake of the infarcted area in the resting 99mTc-Tetrofosmin image (47 +/- 16%) was slightly lower than that in the 201Tl reinjection image (52 +/- 16%). In conclusion, viable myocardium was as clearly identified by 99mTc-Tetrofosmin, as by 201Tl scintigraphy.

Growth cones of dorsal root ganglion but not retina collapse and avoid oligodendrocytes in culture

Axons in the central nervous system of mature mammals generally fail to regenerate following injury. Although the reason for this regenerative failure remains unknown, several lines of evidence suggest that it is due to nonpermissiveness of oligodendrocytes for axonal elongation. However, most of the in vitro experiments carried out so far used neural-crest-derived peripheral neurons to test the permissiveness of oligodendrocytes, although studying the interactions between central neurons and oligodendrocytes is crucially important for elucidating their roles in vivo. In this study we cultured retinas and dorsal root ganglia of the chick embryo with oligodendrocytes obtained from postnatal rat spinal cord and performed time-lapse analysis. Oligodendrocytes were identified with galactocerebroside antibody. Retinal growth cones readily grew over oligodendrocytes, while growth cones of the dorsal root ganglion collapsed and grew away on contacting the oligodendrocytes. Correspondingly, neurite-free areas centered by oligodendrocytes were formed behind growth cones in DRG-oligodendrocyte but not in retina-oligodendrocyte co-culture. These observations suggest the possibility that responsiveness of growth cones to oligodendrocytes is dependent on neuronal type.

A case of AIDS-related hepatic Kaposi's sarcoma

In Japan, Kaposi's sarcoma (KS) is a very rare neoplasm. However, it does occur as one of the complications in patients with acquired immunodeficiency syndrome (AIDS). AIDS-related KS commonly involves the skin, lymph nodes, and gastrointestinal tract. Hepatic KS is sometimes observed in AIDS patients at autopsy, but it is very rarely diagnosed during life. We report a case of hepatic KS in an AIDS patient, detected by ultrasonography (US), computed tomography (CT), and magnetic resonance imaging (MRI) during life and proven at autopsy. Abdominal US revealed multiple hyperechoic tumors along the portal vein. CT scan showed low density and delayed enhancement by contrast material. These tumors were revealed as a low intensity area on a T1-weighted image of MRI and as a high intensity area on T2-weighted and proton density images. US, CT scan, and MRI revealed characteristic findings of hepatic KS. These procedures are very useful for the diagnosis of hepatic KS. To our knowledge, this is the first report of hepatic KS in Japan.

Solitary muscular involvement by tuberculosis: CT, MRI, and scintigraphic features

The authors reported computed tomography (CT), magnetic resonance imaging (MRI) and scintigraphic findings of a patient with solitary muscular tuberculosis in the forearm. All these findings resembled those of other granulomatous inflammatory lesions in the soft tissue such as muscular sarcoidosis.

[Two cases of dilated cardiomyopathy with the relationship between the effect of beta-blocker therapy and the changes of myocardial clearance of 123I-metaiodobenzylguanidine]

Two cases diagnosed dilated cardiomyopathy received beta-blocker therapy, and underwent 123I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy before and after the treatment. In case 1, symptoms and cardiac function were improved in 1 month and 4 months after the treatment (LVEF increased from 19% to 32% and 40%), and myocardial clearance of MIBG decreased from 50% to 27% and 29%. In case 2, both symptoms and cardiac function were not improved in 1 month and 3 months after the treatment (LVEF was changed from 11% to 10% and 13%), and myocardial clearance was not significantly different between before (50%) and after (1 month: 46%, 3 months: 50%) the treatment. It was indicated that myocardial clearance of MIBG might depend on the extent of the improvement of cardiac function and symptoms, and might reflect the effects of beta-blocker therapy.

Laparoscopic nephrectomy using a retroperitoneal approach: comparison with a transabdominal approach

To evaluate the efficacy of the retroperitoneal approach in laparoscopic nephrectomy, our procedures involving laparoscopic nephrectomy using a retroperitoneal approach are described and the clinical results of six patients treated in this way are compared with those of 32 transabdominally nephrectomized patients. Of the six retroperitoneally nephrectomized patients, six kidneys were successfully removed without severe complication, and 28 kidneys were successfully removed in the 32 intraabdominally approached group. Three of the 28 patients had complications requiring open laparotomy. The operating time was 2.7 hours in the 6 retroperitoneal patients and 4.4 hours in the 28 transabdominal patients. Estimated blood loss was 92 ml in the retroperitoneal group and 450 ml in the transabdominal group. The mean postoperative hospital stay was 8 days and 9 days, respectively. These results indicate that the retroperitoneal approach might be preferable in laparoscopic nephrectomy.

Comparison of the chase effects of avidin, streptavidin, neutravidin, and avidin-ferritin on a radiolabeled biotinylated anti-tumor monoclonal antibody

Injection of avidin can decrease the background radioactivity due to a radiolabeled biotinylated monoclonal antibody. We compared the chase effects of avidin, streptavidin, neutravidin, and avidin-conjugated ferritin on a radiolabeled antitumor monoclonal antibody in tumor-bearing nude mice. A radioiodine-labeled biotinylated monoclonal antibody (OST7) was administered to athymic mice bearing osteogenic sarcomas. After 24 h, an avidin, streptavidin, neutravidin or avidin-conjugated ferritin chaser was intravenously injected into the mice. At 2 h after the chase, the biodistribution of the radiolabeled monoclonal antibody was determined. Clearance from the blood was dose-dependently accelerated by avidin and its effect was 10-fold stronger than that of neutravidin or avidin-ferritin. Streptavidin did not promote clearance of the biotinylated antibody. Avidin was the most effective chasing agent for improving the biodistribution of the radiolabeled biotinylated monoclonal antibody among the four avidin derivatives tested.