The inhibitory effect of vitamin E on pulmonary polyamine biosynthesis, cell proliferation and carcinogenesis in mice

We investigated the modulating effect of vitamin E on pulmonary polyamine biosynthesis, cell proliferation and carcinogenesis in mice treated with urethane. Pulmonary ornithine decarboxylase induction and subsequent polyamine accumulation were observed during the initiation and promotion phases of the urethane-induced lung carcinogenesis in mice. The increases of ODC activity and polyamine level during both phases were almost inhibited when a high vitamin E diet was provided. The urethane-increased level of pulmonary proliferating cell nuclear antigen as a marker of cell proliferation during the carcinogenesis was inhibited by vitamin E treatment. Also, vitamin E suppressed the urethane-induced elevation of pulmonary cyclooxygenase activity as a marker of tumor promotion. In conjugation with these events, vitamin E reduced the development of lung tumors in mice treated with urethane. These results indicated that vitamin E could act as a useful chemopreventive agent against lung carcinogenesis in mice due to the regulation of cell proliferation.

The inhibitory effect of vitamin E on K-ras mutation at an early stage of lung carcinogenesis in mice

In this study, we investigated the effect of vitamin E on the activation of the K-ras oncogene with a 61st codon A-->T mutation at an early stage of urethane-induced lung carcinogenesis in mice. Thirty days after urethane injection, the K-ras mutation was detected in 64% of lung samples tested by mutant-allele-specific amplification. The consumption of a supplemented diet with about 20-times more vitamin E than the control diet, only during the promotion phase or during both the initiation and promotion phases of lung carcinogenesis, reduced the frequency of the mutation to 36 and 18%, respectively. Also, vitamin E suppressed the level of proliferating cell nuclear antigen as a marker of cell proliferation in the lungs of mice treated with urethane. These results support the notion that vitamin E is a useful chemopreventive agent against lung cancer.

Mapping of metastasis suppressor gene(s) for rat prostate cancer on the short arm of human chromosome 8 by irradiated microcell-mediated chromosome transfer

Our previous studies demonstrated that human chromosome 8 contains metastasis suppressor gene(s) for rat prostate cancer. However, it is still unknown which portion of human chromosome 8 is associated with suppression of metastatic ability, because all of the clones in which metastatic ability is suppressed contain at least one copy of intact human chromosome 8. In the present study, we used the irradiated microcell-mediated chromosome transfer technique to enrich for specific chromosomal arm deletions of selected chromosomes. The resultant series of human chromosomes 8 with a variety of chromosomal deletions was introduced into highly metastatic Dunning rat prostate cancer cells. All of the resultant microcell hybrids showed reduced metastatic ability. To obtain a smaller size of human chromosome 8 and to locate further the region of metastasis suppressor gene(s), the most reduced size of human chromosome 8 that was generated with the initial irradiated chromosome transfer was retransferred into the Dunning cancer cells without irradiation. The resultant microcell hybrids were analyzed to determine which portion of human chromosome 8 suppressed the metastatic ability of the recipient cells. This analysis demonstrates that the portion of human chromosome 8 containing metastasis suppressor gene(s) for rat prostate cancer cells lies on human chromosome segment 8p21-p12, where frequent allelic losses have been detected in allelotype analyses of human prostate cancer. This suggests that one of the metastasis suppressor genes for rat prostate cancer on human chromosome 8 may also play an important role in the progression of human prostate cancer.

Pancreatic ductal adenocarcinoma: preoperative assessment with helical CT versus dynamic MR imaging

PURPOSE

To compare helical computed tomography (CT) and dynamic, magnetic resonance (MR) imaging in the evaluation of pancreatic ductal adenocarcinoma.

MATERIALS AND METHODS

Dynamic MR images obtained with breath holding, 256 phase- and 512 frequency-encoding steps, 5-mm section thickness, phased-array multicoil, and double-dose gadolinium were available from 21 patients. Dynamic MR images were retrospectively compared with helical CT images in the evaluation of tumor detection, local tumor extension, and vascular involvement.

RESULTS

Tumors were detected on dynamic MR images of 19 of 21 (90%) patients and on helical CT scans of 16 (76%) patients. Dynamic MR imaging had equal or better sensitivity, accuracy, and agreement of tumor grade than did helical CT in the comparison of imaging findings and histopathologic findings. Dynamic MR imaging also had equal or better specificity than had helical CT in determination of local tumor extension and vascular involvement, except in the factors of duodenal invasion and portal venous system involvement. However, there was no statistically significant difference among any of these measurements.

CONCLUSION

Dynamic MR imaging may be better than helical CT in the preoperative detection and evaluation of local tumor extension and of vascular involvement of pancreatic ductal adenocarcinomas.

[A study of 44 patients with Kirisawa type uveitis]

We studied 50 eyes of 44 patients with acute retinal necrosis, Kirisawa type uveitis (KU), in order to examine clinical symptoms, pathogenic viruses, clinical grading, therapy and prognosis for this disease. Varicella-zoster virus (VZV) was the pathogenic organism in 37 eyes of 31 patients, while herpes simplex virus (HSV) was responsible in 13 eyes of 13 patients. There were more elderly patients in the VZV-KU group than in the HSV-KU group. In addition, mutton fat keratic precipitates and retinal exudates were more common in VZV-KU than in HSV-KU. We divided KU eyes into 3 clinical grades: severe, serious, and mild. Using statistical analysis, we found that the VZV-KU group had a significantly greater number of severe and serious cases than the HSV-KU group. Furthermore, some HLA antigens were found to be statistically more common in the VZV-KU group, although no associations were found in the HSV-KU group. 32% of VZV-KU and 67% of HSV-KU eyes had a final visual acuity (fVA) of greater than 0.5. When eyes with an fVA of greater than 0.1 were compared to eyes with an fVA of less than 0.1, we found that combined therapy using acyclovir, interferon beta, and prednisolone was especially effective for VZV-KU, although no significant difference was found for HSV-KU. Thus, it is essential to determine the pathogenic virus causing KU, in order to understand the disease pathogenesis as well as to select appropriate treatment.

Three-dimensional examination of bone structure around hydroxyapatite implants using digital image processing

This study introduced a new method for three-dimensional (3D) examination of the bone structure around an implant and presented 3D bone-implant contact rates. A block of nondecalcified implant tissue was ground gradually at an interval of 80 micrograms for the collection of serial two-dimensional (2D) images. An image of the stained block surface was instantly recorded by a charge-couple device (CCD) camera and computer-aided system. A 3D model was reconstructed from 60-70 sheets of serial 2D images. The 3D bone structure around the implant was shown in perspective and displayed all sides of the implant. The bone-implant contact rate depended on the cutting position and direction in the specimen. The 3D model will be necessary and valuable for the biomechanical study of dynamic bone changes around implants.

Influence of bone quality on the stress distribution. An in vitro experiment

Adequate bone quality and stress distribution to the bone are of decisive importance for implant success. The purpose of this in vitro study was to investigate the influence of bone quality on the stress distribution using 2 implant-bone mimicking models, simulating compact and cancellous bone quality. The resin model was made of an acrylic resin only simulating compact bone quality. The hybrid model was made of 2 kinds of materials, acrylic resin covered with a 1-mm layer of urethane to simulate cancellous bone quality. An implant was embedded in each model, and the abutment and suprastructures were connected to the implant. A strain gauge was placed perpendicular to the implant on the surface of the model and a small accelerometer was attached to the abutment. When an impact load was applied to the suprastructure, both strain and acceleration were measured. Both abutment acceleration and surface strain in the hybrid model decreased rapidly as time progressed when compared to the resin model. Abutment accelerations in the resin model were significantly lower than those in the hybrid model. In the hybrid model, the strain increased as the loading site was moved closer to the strain gauge. The influence of loading sites on strain in the resin model was greater than in the hybrid model. Therefore, the occlusal stress was distributed more widely in the hybrid model than in the resin model. This may indicate that occlusal stress in compact bone may have a tendency to concentrate in particular regions.

Use of interimplant displacement to measure mandibular distortion during jaw movements in humans

It has been reported that the mandibular body and the dental arch distort during jaw movements because of contraction of the jaw muscles. In the present study the relative position between two biointegrated implants approx. 10 mm apart was measured during maximum opening and protrusive movements of the jaw using a magnetic sensor system. Mandibular distortion was evaluated as the change in the sensor signal. In all participants the distal implant deviated to the lingual side relative to the mesial implant and the deviation with jaw protrusion was larger than that with opening movement. The linear displacement of the two implants ranged from 8 to 25 microns during maximum opening and from 10 to 37 microns during jaw protrusion. Further investigation is required to establish the mechanism of this mandibular distortion, which may be of relevance to implant therapy.

A new pedicled seromuscular flap technique for high-risk intestinal anastomoses

A new method for protecting intestinal anastomoses in patients at high risk of anastomotic dehiscence or fistula formation is described herein. This method involves raising a seromuscular flap on a pedicle from the stump of the intestine to be anastomosed. The anastomosis is performed, then covered with the seromuscular flap.

Isolation of cDNA clones of the rat mRNAs expressed preferentially in the prenatal stages of brain development

For better understanding of the molecular mechanisms underlying the developmental processes of the mammalian brain, we isolated rat fetal brain-enriched (FBE) cDNA clones, whose corresponding mRNAs were expressed at least 5-fold more in the fetal brain than in the adult brain. Our modified differential screening procedure, which utilized a two-vector (pT7T3D and pBluescript) system and showed low background levels of colony hybridization for screening, efficiently identified 64 candidate FBE clones from a small number (475) of colonies in the fetal brain cDNA library. After subsequent second screening of the candidate FBE clones by Northern blot analysis, we successfully isolated 22 distinct FBE clones. The nucleotide sequence analysis of the 22 FBE clones revealed that 13 of them had no significant matches to the sequences reported in the databases, whereas 9 of them matched previously reported sequences (alpha-tubulin M alpha 1, beta-tubulin M beta 5, thymosin-beta 10, stathmin, beta-tubulin M beta 2, alpha-internexin, ferritin Lg chain, neuronatin and amphoterin), most of which have been shown to be down-regulated during brain development. We also found that the Northern blot analysis in the second screening could be replaced by cDNA library DNA-Southern blot analysis, in most clones corresponding to relatively abundantly expressed mRNAs. Thus, once the cDNA library is constructed, clone selection will be possible in such clones without the use of additional RNA or Northern blot in screening, allowing the analysis of small brain regions of interest.

Mapping of metastasis suppressor gene(s) for rat prostate cancer on the short arm of human chromosome 8 by irradiated microcell-mediated chromosome transfer

Our previous studies demonstrated that human chromosome 8 contains metastasis suppressor gene(s) for rat prostate cancer. However, it is still unknown which portion of human chromosome 8 is associated with suppression of metastatic ability, because all of the clones in which metastatic ability is suppressed contain at least one copy of intact human chromosome 8. In the present study, we used the irradiated microcell-mediated chromosome transfer technique to enrich for specific chromosomal arm deletions of selected chromosomes. The resultant series of human chromosomes 8 with a variety of chromosomal deletions was introduced into highly metastatic Dunning rat prostate cancer cells. All of the resultant microcell hybrids showed reduced metastatic ability. To obtain a smaller size of human chromosome 8 and to locate further the region of metastasis suppressor gene(s), the most reduced size of human chromosome 8 that was generated with the initial irradiated chromosome transfer was retransferred into the Dunning cancer cells without irradiation. The resultant microcell hybrids were analyzed to determine which portion of human chromosome 8 suppressed the metastatic ability of the recipient cells. This analysis demonstrates that the portion of human chromosome 8 containing metastasis suppressor gene(s) for rat prostate cancer cells lies on human chromosome segment 8p21-p12, where frequent allelic losses have been detected in allelotype analyses of human prostate cancer. This suggests that one of the metastasis suppressor genes for rat prostate cancer on human chromosome 8 may also play an important role in the progression of human prostate cancer.

[Study on the sclerosing agent for the treatment of simple renal cysts]

BACKGROUND

The objective of this study is to evaluate the sclerosing agents for simple renal cysts.

METHODS

Thirty-three renal cysts of 30 patients were treated by injection of sclerosing agents with the guidance of ultrasonography. Among them, 22 were treated with ethanol, and 11 with minocycline-hydrochloride (MINO).

RESULTS

Clinical efficacy rates and volume reduction rates in each treatment group of ethanol or MINO, were 100% and 90.9%, and 91.2 +/- 13.1% (mean +/- SD) and 83.2 +/- 28.5%, respectively. Although several complications including pain and intoxication were observed in ethanol (47.4%), no complications were observed in MINO.

CONCLUSION

The instillation of MINO into renal cysts is an effective, safe and simple treatment. It is thought that it can be the first choice of treatment for simple renal cysts.

[MR imaging of the femoral marrow in adult acute leukemia: correlation of MRI patterns with FAB subtype and prognosis]

MR imaging of the femoral marrow was performed in 36 patients with untreated acute myeloid leukemia (AML) and 7 patients with acute lymphocytic leukemia (ALL). The MRI appearance was classified into five patterns: 1) fatty marrow; 2) faint signal; 3) nodular pattern; 4) heterogeneous infiltration; and 5) diffuse infiltration. The MRI patterns of the femoral marrow were compared among the FAB subtypes of acute leukemia, and the MRI patterns were correlated with prognosis. All five MRI patterns were observed in the femoral marrow in adult acute leukemia, and diffuse infiltration was most commonly seen (41.9%). A completely fatty marrow was also depicted in two cases (4.7%) and faint signal in four cases (9.3%) in spite of untreated acute leukemia. The M2 subtype of AML tended to be demonstrated as a minimally abnormal MRI finding, which was significantly different from the other types of AML. The patients who showed fatty marrow or faint signal were thought to have a good prognosis, while diffuse or heterogeneous infiltration was regarded as a poor prognostic sign. However, there were some exceptions to these rules, and no significant differences were revealed in prognosis between minimally abnormal and advanced MRI patterns. We concluded that MRI of the femoral marrow could be useful in the assessment of tumor volume of adult acute leukemia, and that there were limitations to predicting prognosis on the basis of the MRI manifestations.

Cloning, sequence analysis, and expression in Escherichia coli of the gene encoding the Candida utilis urate oxidase (uricase)

A urate oxidase (uricase) gene was cloned from Candida utilis with an oligonucleotide probe based on the amino acid sequence of cyanogen bromide-cleaved uricase. The uricase gene contains 909 base pairs and encodes a protein with a predicted mass of 34,193 Da. Candida uricase was similar (49% match in amino acid sequence) to the uricase from Aspergillus flavus. The uricase from Candida utilis has four cysteines and one of them, Cys168, participates in the enzyme activity. This enzyme was expressed to a level of about 20% of total cellular protein in an Escherichia coli cell as a soluble and functional form.

Expression of the KAI1 protein in benign prostatic hyperplasia and prostate cancer

The KAI1 gene, recently identified as a metastatic suppressor gene for prostate cancer, was cloned and was revealed to be identical to the C33/IA4/ R2/4R9 gene. The expression of KAI1 protein was examined immunohistochemically in the tissues from 14 cases of benign prostatic hyperplasia and 46 cases of prostate cancer using mouse monoclonal anti-human C33 antibody. In benign prostatic hyperplasia tissues, KAI1 protein was uniformly expressed in the glandular cell membrane at cell-to-cell borders. The KAI1 protein in the tissues of untreated prostate cancer was also located at similar sites to those of benign prostatic hyperplasia, but the percentage of strongly positive cancer cells was correlated inversely to the Gleason pattern (P < 0.0001, one-way analysis of variance). There was also a statistically inverse correlation between the percentage of KAI1-positive cancer cells and the clinical stage (chi 2 = 9.6; P = 0.0081). In 4 cancer death cases relapsed from endocrine therapy, KAI1 protein was not stained in either primary or metastatic foci. These results indicate that the expression of KAI1 protein correlates to tumor characteristics in prostate cancer.

The activation of K-ras gene at an early stage of lung tumorigenesis in mice

To clarify the exact timing of K-ras gene mutational activation in lung tumorigenesis of mice, we applied a sensitive mutant allele specific amplification (MASA) method to pulmonary DNA from urethane-treated mice. The activation of K-ras gene with 61st codon AT mutation was detected in the lungs of mice at day 14 but not day 7 after urethane treatment by MASA. The mutation of MASA products was also checked by XbaI restriction fragment length polymorphism analysis and DNA sequencing. These data suggest that the mutation of K-ras gene in the lungs of mice treated with urethane occurred at the early stage of lung tumorigenesis.

Malignant astrocytomas with homozygous CDKN2/p16 gene deletions have higher Ki-67 proliferation indices

p16 is involved in a cell-cycle regulatory cascade that includes cyclin-dependent kinase 4 (cdk4), cyclin D1 and pRb. Alterations of each of these components have been described in primary human glioblastoma multiforme (GBM) or GBM cell lines, and alterations of the individual components of this pathway appear inversely correlated with one another. While this suggests that disruption of any individual component has similar oncogenic effects, homozygous deletions of the CDKN2/p16 gene are the most common genetic alteration. We investigated the relationship between homozygous CDKN2/ p16 deletions and cellular proliferation in 50 primary astrocytomas (2 WHO grade I pilocytic astrocytoma, 15 grade II astrocytomas, 20 grade III anaplastic astrocytomas and 13 grade IV GBMs). Using a comparative multiplex PCR assay, homozygous deletions of the CDKN2/p16 gene were detected in 5 anaplastic astrocytomas (25%) and 6 GBMs (46%), but in none of the lower-grade tumors. Ki-67 immunohistochemistry was used to assess the number of proliferating cells in the same samples used for molecular genetic analysis. In both anaplastic astrocytomas and GBMs, Ki-67 proliferation indices were significantly higher in tumors with CDKN2/p16 deletions (20%) than in those without deletions (10%; p = 0.0001). These results suggest that homozygous CDKN2/p16 deletions in high-grade astrocytomas may have a more deleterious effect on cell cycle control than the other aberrations in the p16-cdk4-cyclin D1-pRb pathway, and may provide one explanation for why homozygous CDKN2/p16 deletions are more common genetic events in high-grade astrocytomas than RB mutations or CDK4 amplification.

Breath-held MR cholangiopancreatography with half-averaged single shot hybrid rapid acquisition with relaxation enhancement sequence: comparison of fast GRE and SE sequences

PURPOSE

Our goal was to determine whether half-averaged single shot hybrid rapid acquisition with relaxation enhancement (single shot hybrid RARE) sequence can improve image quality, duct conspicuity, signal intensity ratio (SIR), and contrast-to-noise ratio (CNR) of MR cholangiopancreatography (MRCP) by comparing it with two other MRCP sequences: fast SE (FSE) and contrast-enhanced Fourier-acquired steady-state technique (CE-FAST).

METHOD

MRCP with three sequences was obtained in 46 people (10 volunteers, 36 patients with pancreatobiliary disease). Overall image quality and duct conspicuity were graded. SIR and CNR were also measured.

RESULTS

Overall image quality was graded excellent or good in all 46 patients (100%) with single shot hybrid RARE, in 38 of 46 (83%) with FSE, and in 5 of 46 (11%) with CE-FAST. Duct conspicuity was the best in single shot hybrid RARE statistically. SIR was the highest in FSE, while CNR was highest statistically in single shot hybrid RARE of three sequences.

CONCLUSION

Single shot hybrid RARE can provide consistently higher quality MRCP than FSE and CE-FAST because sequential images by single shot hybrid RARE minimize respiratory, bowel, and cardiac motion artifacts.