Mechanism of 'bystander effect' killing in the herpes simplex thymidine kinase gene therapy model of cancer treatment

'Bystander' killing of adjacent wild-type tumor cells was seen when tumors transduced with the herpes thymidine kinase gene were treated with the antiviral agent ganciclovir (GCV). Some tumors were 'bystander-sensitive' while others were 'bystander-resistant'. Mixtures of different 'sensitive' tumor lines showed cross-transfer of bystander killing, while in mixtures of 'resistant' with 'sensitive' tumors, the resistant phenotype was predominant. Using 3H-GCV with 'sensitive' mixtures, phosphorylated 3H-GCV was found in both herpes thymidine kinase transduced and unmodified cells, while 'resistant' cell combinations showed little or no transfer of phosphorylated GCV between cells. The capacity of intracellularly produced nucleotide toxin to spread from cell to cell within a tumor mass effectively amplifies the apparent efficiency of gene transfer in the tumor and makes feasible the use of this system for therapy of localized cancer.

Tissue-specific and growth-regulated expression of CD44 variable exon determinants in the mouse

CD44 is a polymorphic transmembrane glycoprotein widely expressed in lymphocytes and epithelial cells. CD44 polymorphism reflects both posttranslational modification and alternative splicing of up to 10 variably expressed exons in the membrane-proximal CD44 extracellular domain. An analysis of CD44 variable exon-containing isoforms in the mouse was carried out by generating a panel of monoclonal antibodies against variable region determinants of CD44. Immunohistochemical analysis demonstrated selective patterns of expression of CD44 variable exon determinants in normal tissues, and flow cytometric analysis identified expression of CD44 variable exon-dependent determinants in epithelial and lymphoid cell lines. Regulation of alternative splicing was studied by characterization of cell surface expression of CD44 variable exon determinants on HC11 mammary epithelial cells, and it was demonstrated that variably spliced isoforms are selectively regulated as a function of growth phase in vitro. These results demonstrate the tissue-specific and growth-regulated expression of the CD44 isoform at the level of cell surface protein products and identify isoform-specific determinants that can be targeted in analysis of isoform-specific function.

Isolation and characterization of a GDP/GTP exchange protein specific for the Rab3 subfamily small G proteins

The Rab small G protein family, consisting of nearly 30 members, is implicated in intracellular vesicle trafficking. They cycle between the GDP-bound inactive and GTP-bound active forms, and the former is converted to the latter by the action of a GDP/GTP exchange protein (GEP). No GEP specific for each Rab family member or Rab subfamily has been isolated. Here we purified a GEP from rat brain with lipid-modified Rab3A as a substrate. The purified protein was specifically active on Rab3A, Rab3C, and Rab3D of the Rab3 subfamily. Of these subfamily members, Rab3A and Rab3C are implicated in Ca2+-dependent exocytosis, particularly in neurotransmitter release. This GEP (Rab3 GEP) was active on the lipid-modified form, but not on the lipid-unmodified form. Rab3 GEP showed a minimum molecular mass of about 200 kDa on SDS-polyacrylamide gel electrophoresis. We cloned its cDNA from a rat brain cDNA library and determined its primary structure. The isolated cDNA encoded a protein with a Mr of 177,982 and 1,602 amino acids, which showed no homology to any known protein. The recombinant protein exhibited GEP activity toward Rab3A, Rab3C, and Rab3D. Northern blot and Western blot analyses indicated that Rab3 GEP was expressed in all the rat tissues examined with the highest expression in brain.

Unique tissue distribution of a mouse macrophage C-type lectin

We examined mouse tissue for the expression of macrophage galactose/N-acetylgalactosamine-specific C-type lectin using a rat monoclonal antibody (mAb) specific for this lectin (mAb LOM-14). The binding of mAb LOM-14 was detected in detergent extracts from tissue by means of immunoblotting analysis. It was shown that this mAb did not cross-react with mouse hepatic lectins, a structural homologue. The macrophage lectin was widely distributed among various mouse tissues as judged by the affinity isolation followed by the immunochemical detection. The exceptions were brain, liver, kidney, small intestine, and peripheral blood. Extracts from these organs exhibited, at best, very weak signals upon mAb LOM-14 binding, despite the presence of cells expressing macrophage markers. The most intense signal was observed in the extract from skin, suggesting that cells expressing this lectin are abundant in skin. The tissues shown to contain this lectin were further investigated by immunohistochemical staining of the sections. Cells were distributed in the connective tissue and in the interstice, particularly the dermis and subcutaneous layer of skin. Cells localized in the epithelium of skin (epidermis) or other epithelia that we examined were not stained. Perivascular localization of cells stained with mAb LOM-14 was also demonstrated in cardiac and skeletal muscle tissues. Immunoelectron microscopy revealed the presence of this lectin along the rough endoplasmic reticulum. In conclusion, the distribution of C-type lectin specific for galactose/N-acetylgalactosamine in mice was unique. The connective tissue-specific distribution should provide important information on the biological role of this lectin.

Immunoregulatory roles of adhesive interactions between lymphocytes and gingival fibroblasts

Chronic adult periodontitis is usually characterized by inflammatory cell accumulation in the extravascular periodontal connective tissue. In order to reveal how the lymphocyte migration and retention in periodontal lesions is regulated, we have focused on the molecular basis for the adhesive interactions between lymphocytes and human gingival fibroblasts (HGF). In this study, we investigated the involvement of cell adhesion molecules in adhesive interactions between lymphocytes and HGF. We found that activated lymphocytes bound strongly to HGF and VLA integrins, extracellular matrix receptors, play crucial roles in the binding. Interestingly, we first revealed that CD44 molecules (hyaluronate receptor) on lymphocytes also participated in lymphocyte-HGF interactions and that hyaluronate anchored on the surface of HGF functioned as the ligand for CD44. In addition, when HGF were stimulated with inflammatory cytokines such as IL-1, TNF alpha and IFN gamma, the binding avidity between lymphocytes and HGF was significantly increased and the adhesion was mainly mediated by LFA-1/ICAM-1 pathway. We then examined the possibility whether lymphocyte-HGF interaction may cause activation of HGF. When HGF directly interacted with lymphocytes for 3 h, IL-1 beta mRNA expression was clearly increased in HGF. These findings suggested that the adhesive interactions between lymphocytes and HGF was mediated at least by VLA integrins, LFA-1/ICAM-1 and CD44/hyaluronate and that the heterotypic cell-cell interactions could mutually cause intracellular signal transduction.

Dual phased array coils for high-resolution MRI of the shoulder

We connected two 3-inch coils to a dual phased array receiver system and sandwiched the shoulder between the two coils. To obtain a quantitative assessment of the improved SNR, we imaged a phantom with both the dual phased array coils and the standard shoulder coil. SNR as a function of distance from the coils was computed by the National Electrical Manufacturers Association (NEMA) standard. At the expected depth of the humeral head, the SNR of the phased array coils on single excitation was 1.42 times that of the standard shoulder coil on two excitations. The higher quality of the images on single excitation shortened the imaging procedure. The dual phased array coils realized the minimum FOV: 8 cm with a pixel of 0.31 x 0.41 mm. The dual phased array coils achieved high spatial resolution images of the shoulder with significantly shorter imaging times.

Central neurocytoma with clinically malignant behavior

We describe two cases of central neurocytoma that did not show histopathologic features of anaplasia but did show tumor dissemination after surgery and radiation therapy. CT and MR imaging before surgery depicted extraventricular extension of the tumors. The importance of radiologic findings is stressed.

Transport of glucose across the blood-tissue barriers

In specialized parts of the body, free exchange of substances between blood and tissue cells is hindered by the presence of a barrier cell layer(s). Specialized milieu of the compartments provided by these "blood-tissue barriers" seems to be important for specific functions of the tissue cells guarded by the barriers. In blood-tissue barriers, such as the blood-brain barrier, blood-cerebrospinal fluid barrier, blood-nerve barrier, blood-retinal barrier, blood-aqueous barrier, blood-perilymph barrier, and placental barrier, endothelial or epithelial cells sealed by tight junctions, or a syncytial cell layer(s), serve as a structural basis of the barrier. A selective transport system localized in the cells of the barrier provides substances needed by the cells inside the barrier. GLUT1, an isoform of facilitated-diffusion glucose transporters, is abundant in cells of the barrier. GLUT1 is concentrated at the critical plasma membranes of cells of the barriers and thereby constitutes the major machinery for the transport of glucose across these barriers where transport occurs by a transcellular mechanism. In the barrier composed of double-epithelial layers, such as the epithelium of the ciliary body in the case of the blood-aqueous barrier, gap junctions appear to play an important role in addition to GLUT1 for the transfer of glucose across the barrier.

[Two patients with mediastinal parathyroid cysts]

We encountered two patients with mediastinal parathyroid cysts. Patients 1 was a 44-year-old man with no complaints who had an abnormal shadow on a roentgenogram of the chest. An iperation was performed because a computed tomogram and a magnetic resonance image showed a cyst in the upper right part of the mediastinum, which was suspected to be a mediastinal thyroid cyst. Patient 2 was a 77-year-old woman with no complaints who had an abnormal shadow on a roentgenogram of the chest. Therapeutic thoracoscopy was performed because a mediastinal cyst was suspected based on the results of computed tomography and magnetic resonance image. Both patients had thin-walled that they were mediastinal parathyroid cysts. Mediastinal parathyroid cysts are very rare. We searched the medical literature but found previously published reports of only 39 cases.

Evidence of metal binding activities of pentadecapeptide from Panax ginseng

A tetradecapeptide from ginseng (Panax ginseng) root showing anti-lipolytic activity in an isolated rat fat cell assay was chemically synthesized for analysis of metal binding activities in vitro. Binding activities against several metal ions were analysed by measuring mobility shifts during capillary zone electrophoresis experiments. The ginseng polypeptide (GPP) showed the greatest increase in effective molecular electrophoretic mobility in the presence of Mg2+. Mobility was also affected in the presence of La3+, Mn2+, Ca2+ and Zn2+ ions. Analysis with the dye Stains-all revealed GPP to possess a cation binding site similar to those in Ca(2+)-binding proteins. GPP thus appears to be a metal binding peptide. The results of this analysis suggested that GPP may perform its anti-lipolytic activities through an ability to modulate the level of free cellular Mg2+ and Mn2+ ions.

Infantile choriocarcinoma: a case report with MRI, angiography and bone scintigraphy

Infantile and maternal choriocarcinoma is a very rare disease. We report a case with the characteristic clinical features of infantile choriocarcinoma: developing anemia, hemorrhagic liver tumors, rapid progression to death and maternal choriocarcinoma. Bone scintigraphy showed increased uptake by the liver tumors. In this case there were two possible primary sites: the placenta of this pregnancy and a hydatidiform mole that had been present 2 years previously.

A case of pregnancy with adult T-cell leukemia

The incidence of adult T-cell leukemia (ATL) arising in women of childbearing age is documented infrequently. This report is the second in the world's literature of a case of ATL that occurred during pregnancy. A 43-year-old woman developed ATL during pregnancy and died of widespread disease 4 weeks after cesarean delivery.

Decreased very-low-density lipoprotein and low-density lipoprotein receptor messenger ribonucleic acid expression in placentas from preeclamptic pregnancies

OBJECTIVE

Our purpose was to investigate the levels of very-low-density lipoprotein and low-density lipoprotein receptor messenger ribonucleic acid expression in placentas obtained from normal pregnant women at various gestational stages and from patients with preeclampsia.

STUDY DESIGN

The relative level of expression of very-low-density lipoprotein and low-density lipoprotein receptor messenger ribonucleic acid in each sample was determined by Northern blot analysis as a ratio of the intensity to that of glyceraldehyde-3-phosphate dehydrogenase messenger ribonucleic acid.

RESULTS

The expression of very-low-density lipoprotein receptor messenger ribonucleic acid increased significantly (p < 0.05) from both the first (n = 9) and second (n = 8) trimesters to the third (n = 11) trimester. Similarly, the expression of low-density lipoprotein receptor messenger ribonucleic acid increased significantly (p < 0.05) from the first to the third trimester. The expression of both very-low-density lipoprotein and low-density lipoprotein receptor messenger ribonucleic acids in third-trimester placentas from preeclamptic pregnancies (n = 13) was significantly lower than that in normal pregnancies in the third trimester.

CONCLUSION

These results demonstrate the expression of very-low-density lipoprotein and low-density lipoprotein receptor messenger ribonucleic acids in the human placenta, both of which increase at late gestational stages, and the decreased expression in cases of preeclampsia. Abnormal fetomaternal lipid metabolism resulting from low expression of these receptors in the placenta may be involved in the pathogenesis of preeclampsia.

Inhibition of Betacyanin Accumulation by Abscisic Acid in Suspension Cultures of Phytolacca americana

Growth of cells and the accumulation of betacyanin were suppressed by the addition of abscisic acid (ABA) to suspension cultures of Phytolacca americana. The decrease in the accumulation of betacyanin was overcome by exogenously supplied tyrosine which is a precursor of betacyanin. ABA decreased the level of free tyrosine in the cells. Feeding experiments using labeled tyrosine revealed that ABA reduced the incorporation of labeled tyrosine into betacyanins (to about 50% of the control rate). These results suggest that both the availability of tyrosine and the biosynthetic activity of the pathway from tyrosine to the betacyanins are involved in the inhibition of the accumulation of betacyanins by ABA in Phytolacca americana cells.

Adherence of synovial cells on EDA-containing fibronectin

OBJECTIVE

To investigate the role of EDA-containing fibronectin (EDA+ FN), a splice variant of FN detectable in association with cellular transformation, in the adherence of synovial cells (SC) on rheumatoid cartilage surface.

METHODS

The number of SC adherent on cartilage slices or on culture plates containing either EDA+ FN or plasma FN (pFN) was enumerated under a phase-contrast microscope. The portion of the FN molecule responsible for adherence of SC onto EDA+ FN was investigated by inhibition studies using antibodies or peptide fragments.

RESULTS

SC adhered more strongly on the surfaces containing EDA+ FN than on those containing pFN (P < 0.01). When monoclonal antibodies against the EDA or the carboxyl-terminal heparin-binding (Hep2) domains were used, adhesion of SC onto EDA+ FN was reduced to a level comparable with that onto pFN. FN fragments containing Hep2 or heparan sulfate inhibited the adhesion of SC onto EDA+ FN. Treatment of SC with heparitinase, but not heparinase, reduced the adhesion of SC onto EDA+ FN.

CONCLUSION

EDA+ FN enhances adherence of SC on the matrix via the Hep2 region of EDA+ FN.

Prediction of the rodent carcinogenicity of organic compounds from their chemical structures using the FALS method

Fuzzy adaptive least-squares (FALS), a pattern recognition method recently developed in our laboratory for correlating structure with activity rating, was used to generate quantitative structure-activity relationship (QSAR) models on the carcinogenicity of organic compounds of several chemical classes. Using the predictive models obtained from the chemical class-based FALS QSAR approach, the rodent carcinogenicity or noncarcinogenicity of a group of organic chemicals currently being tested by the U.S. National Toxicology Program was estimated from their chemical structures.

Down-regulation of S-adenosylhomocysteine hydrolase in the active methyl transfer system in the brain of genetically epileptic El mice

To study the role of cerebral methylation in epileptogenesis, we investigated the active methyl transfer pathway in the brain of genetically epileptic El mice. We examined S-adenosylhomocysteine (AdoHcy) hydrolase activity (by high performance liquid chromatography), the corresponding mRNA levels (by competitive reverse transcription-polymerase chain reaction), as well as S-adenosylmethionine (AdoMet) and AdoHcy levels in epileptic El and non-epileptic control ddY mice. The level of AdoHcy, a potent feedback inhibitor in the methyl transfer system, was relatively high throughout growth, particularly in 15 week old El mice where it was increased approximately 20% compared to control ddY mice. AdoHcy hydrolase activity in the El mice brain did not increase during growth, which was confirmed by the finding that mRNA synthesis from the hydrolase gene behaved likewise. In contrast, ddY mice exhibited a gradual increase in the mRNA synthesis up to three fold and 20% increase in the enzyme activity at 15 weeks of age compared to those of El mice in which the seizure frequency was 100%. The levels of AdoMet, a versatile methyl donor, did not change throughout growth. We concluded that the down-regulation of AdoHcy hydrolase results in the accumulation of AdoHcy, possibly inducing an unstable state including seizures in the El mouse brain. El mice predisposed to epilepsy may be characterized by disordered feedback regulation of the AdoMet-dependent methyl transfer pathway.

Sclerosing encapsulating peritonitis in patients undergoing continuous ambulatory peritoneal dialysis: a report of the Japanese Sclerosing Encapsulating Peritonitis Study Group

Patients undergoing continuous ambulatory peritoneal dialysis (CAPD) who developed sclerosing encapsulating peritonitis (SEP) were retrospectively studied in 130 centers in Japan. Among 6,923 patients undergoing CAPD between 1980 and 1994 only 62 (0.9%) given CAPD developed SEP. There were 38 men and 24 women, ranging in age from 20 to 87 years (average age, 48.3 years). These 62 patients developed SEP 10 to 138 months (average, 65.4 months) after starting CAPD. The average frequency of peritonitis before developing SEP was 3.3 times. Five of the 62 patients with SEP had no history of peritonitis, and 27 (43.5%) of them died of various causes in the study period. The major causes of death were almost invariably related to problems concerning bowel obstruction or complications of surgery, such as malnutrition or septicemia. It was concluded that SEP is one of the most serious complications of CAPD, and constant surveillance is necessary to detect SEP in patients during CAPD.

[The prognostic factors in astrocytic tumors: analysis by the Kaplan-Meier method and the Weibull log-linear model]

As the prognosis of astrocytic tumors depends on various factors, identifying prognostic factors should be useful for developing strategies to cope with them. Between 1975 and 1994, more than 200 patients with astrocytic tumors were treated in Kagoshima University. Of these patients, 149 (grade I: 17, grade II: 42, grade III: 41, grade IV: 42, unproven: 7) have been followed up. Records of these patients were retrospectively reviewed for age at the time of initial symptoms, gender, histological grade (WHO), extent of tumor resection, radiation therapy, and administration of anticancer agents. We used the Kaplan-Meier method and the Weibull log-linear model to analyze the relation between survival time and these prognostic factors. Survival time was counted from onset of symptoms, and age of initial treatment was used as a covariant. The mean age of males at the initial diagnosis was 40.8 years (n = 77), and that of females was 39 years (n = 72). Using the Kaplan-Meier method, the mean survival time of the 149 patients was 101 months (males; 72.7 months, females; 134.5 months). Mean survival time of grade II was 144.3 months, that of grade III was 95.2 months, and grade IV (glioblastoma) was 15.9 months. Histological grades and mean ages of the groups showed a positive correlation. Among grades II, III and IV, the Kaplan-Meier survival curves were significantly different (p < 0.0001) according to the log-rank test. By the extent of surgical resection (subtotal or greater resection, partial resection, and less than partial resection), the mean survival time showed a significant difference (p < 0.05) on the log-rank test. However, we could not detect a significant difference in survival time between the group that received chemotherapy and the group which did not. The Weibull log-linear analysis indicated that gender, age, histological grade (WHO), extent of surgery, and dose of radiation therapy were prognostic factors. Covariants of grades II, III, and IV made survival time 0.314, 0.179, and 0.069 times as long as that of grade I. The survival time after "partial resection" became 1.415 times as long as the survival time after "less than partial resection". The covariant of "greater than subtotal resection" showed a prolonged survival time of 2.916 compared with that of "less than partial resection". As for age at treatment, the older the patient was, the shorter the survival time. The rate was 0.986 for each year of age. Irradiation of one Gy increased survival time by 1.015 times. Chemoimmunotherapy (dose of ACNU and interferon beta) could not be confirmed as an effective covariant.

Extraforaminal stenosis in the lumbosacral spine. Efficacy of MR imaging in the coronal plane

PURPOSE

To review experience with MR images of extraforaminal (EF) stenosis in the lumbosacral spine.

MATERIAL

MR images from 9 patients with 10 EF stenoses were reviewed. The diagnosis was confirmed in 6 patients at surgery, and in 4 on the basis of findings of nerve root injection combined with nerve block.

RESULTS AND CONCLUSION

All patients had congenital lumbosacral anomalies with various degrees of fixation between the last formed level and the pelvis. In all cases, affected roots were compressed between the transverse process of the last lumbar segment and the sacral ala. MR using coronal plane imaging demonstrated the root impingement directly in the far lateral zone in all patients. However, sagittal and axial images were unable to define the EF stenoses in all patients. The results of this study show that a transitional vertebra is a cause of EF stenosis and that MR images using coronal plane are useful in the assessment of EF stenosis.

Isolation and primary culture of rat cerebral microvascular endothelial cells for studying drug transport in vitro

To establish the cerebral microvascular endothelial cell (CMEC) culture system for animals commonly utilized in in vivo studies, we developed a method for isolation and culture of rat CMECs, and the model system was used in preliminary in vitro transport experiments. The isolated rat brains were minced. After an incubation with dispase, a fraction of microvessels was obtained by the dextran gradient. The tissue was filtered and dissociated using collagenase/dispase. After the enzyme treatment, the microvessels were layered onto the top of Percoll gradient and centrifuged for purification. Specific enzyme activities of alkaline phosphatase and gamma-glutamyltransferase in the preparations gradually increased as the isolation process progressed. The isolated cells reached confluence after 5-7 days in culture. The cultured cells had Factor VIII-related antigen and an uptake of acetylated-low density lipoprotein labeled with 1,1'-dioctadecyl-3,3, 3',3'-tetramethyl-indocarbocyamine perchlorate (Dil-Ac-LDL). In the transport studies, thawed cells after several months under -80 degrees C were used. The cultured cells after the freezing preservation also had CMEC characteristics, the same as the cells seeded immediately after isolation. The permeability of [14C]-mannitol, an impermeable marker for blood-brain barrier, was considerably reduced when the cell monolayer was present. The transport of [3H]3-O-methyl-D-glucose was significantly inhibited by the unlabeled compound. Furthermore, 2,4-dinitrophenol, an uncoupler of oxidative phosphorylation, significantly diminished the transport of [3H]L-proline. These results indicated that the cell monolayer obtained in the present study could be applicable to drug transport studies through the blood-brain barrier in vitro.