Carrier-mediated transport of oligopeptides in the human fibrosarcoma cell line HT1080

To explore the feasibility of targeting human tumor cells via their transport systems, dipeptide uptake was studied in the human fibrosarcoma cell line HT1080 and the human fibroblast cell line IMR-90 by the use of hydrolysis-resistant glycylsarcosine (Gly-Sar). The uptake of [14C]Gly-Sar into HT1080 was time dependent. Kinetic analysis of the concentration dependence of the initial rate of [14C]Gly-Sar uptake showed that a carrier-mediated transport system with a K(m) of 11.4 +/- 3.3 mM and V(max) of 26.8 +/- 4.0 (nmol/15 min/mg protein) and a nonsaturable component (k(d) of 0.80 microl/15 min/mg protein) were responsible for the dipeptide uptake by HT1080 cells. The optimal pH for the maximal uptake was around 6.0. [14C]Gly-Sar uptake was inhibited by various di- and tripeptides and peptide-mimetic drugs, such as bestatin and cefadroxil. [14C]Gly-Sar uptake was not affected by the presence of amino acids or tetra- or pentapeptides. The uptake of cefadroxil was reduced significantly by unlabeled Gly-Sar. Moreover, Gly-Gly and Gly-Leu produced an increase in the apparent K(m) of the uptake of Gly-Sar without altering V(max). On the other hand, dipeptide uptake by IMR-90, which is a normal diploid cell line (not malignant), showed no saturable transport. These results suggest that HT1080 cells take up dipeptides via a pH-dependent transporter. This is the first report showing that a dipeptide transport system, which is similar but not identical to the well-characterized oligopeptide transporters PepT1 and PepT2, exists in fibroblast-derived tumor cells but not in normal fibroblasts. The present finding could be the basis of a novel strategy for the specific delivery of oligopeptide-mimetic anticancer drugs into tumor cells.

Chromosome assignment of aberrant NotI restriction DNA fragments in primary hepatocellular carcinoma

DNA aberrations in human hepatocellular carcinoma (HCC) were studied by two-dimensional DNA electrophoresis analysis. Five intensified and 60 dwindling spots were detected recurrently in the two-dimensional profile which showed about 3000 restriction DNA fragments as distinctive spots. We assigned these aberrant spots to chromosomes, using the chromosome-assigned two-dimensional profile. Four of the five intensified, and 53 of the 60 dwindling spots were given chromosome assignments. Intensified spots were assigned to chromosomes 5, 6, 9 through 12, 16 and 18. Among the dwindling spots, the highest incidence of aberrations was found on chromosome 16, followed by 9 through 12 and chromosome 2. No aberrations were detected in chromosomes 7, 21, 22 or Y.

Expression of midkine and pleiotropin in ovarian tumors

OBJECTIVE

To compare the expression of midkine and pleiotropin in malignant ovarian tumors with that in normal and benign ovarian tissue.

METHODS

Total RNA was isolated from 23 samples of normal ovaries, 15 benign ovarian tumors, and 36 malignant ovarian tumors. Midkine and pleiotropin gene expression was examined by using Northern blot analysis. To confirm the localization of midkine expression, in situ hybridization and immunohistochemical analyses were performed. The truncated midkine messenger RNA was examined using polymerase chain reaction with complementary DNA synthesized from total RNA with reverse transcriptase.

RESULTS

Expression of midkine gene was observed in 19 of 23 normal ovary samples and in 51 of 53 ovarian tumors (13 of 15 benign, both of the two borderline tumors, and all 36 malignant tumors). Pleiotropin gene was expressed in six normal ovaries and in 24 tumors (nine benign, two borderline, and 13 malignant tumors). The expression of midkine in germ cell tumors was significantly lower than in epithelial tumors, whereas expression in malignant epithelial tumors was significantly higher than in benign ones. In germ cell tumors, two samples with differentiated neural tissues showed high levels of pleiotropin gene expression. In situ hybridization and immunohistochemical analysis showed strong expression of midkine in cancer cells. The truncated midkine messenger RNA was not found in any of the normal, benign, or malignant tissues examined.

CONCLUSION

These results suggest an association between midkine and carcinogenesis. Expression of pleiotropin is more restricted, and high levels of its expression may be correlated with neural differentiation.

Expression of transforming growth factor alpha and epidermal growth factor receptor in human hepatocellular carcinoma

Transforming growth factor alpha (TGF-alpha) is thought to be involved in liver regeneration, cellular proliferation, and hepatocarcinogenesis. We have looked at the relationship between TGF-alpha and it's receptor, and have attempted to relate the expression of TGF-alpha and it's receptor to the differentiation of hepatocellular carcinoma (HCC) on serial sections of HCC. We examined immunohistochemically the expression of the TGF-alpha and of epidermal growth factor receptor (EGFR) proteins in the same area of 53 nodules (< 5 cm in diameter) of HCC obtained from patients. Immunoreactive proteins were visualized by using a biotin-streptoavidin system (LSAB Kil, Dako). TGF-alpha was strongly expressed in 29 of 53 (54.7%) nodules. Specimens strongly positive for TGF-alpha were found mainly in well-differentiated HCC, while specimens positive for EGFR were found mainly in poorly differentiated HCC (p < 0.05). In the tissues that stained weakly positive for TGF-alpha, the expression of EGFR differed significantly, according to the degree of HCC histologic differentiation (p < 0.05). These results led us to speculate that the expression of TGF-alpha and EGFR might be related to the pattern of histologic differentiation of HCC.

A case of an iliopsoas abscess in a neonate

The present study describes a male neonate with an iliopsoas abscess. He was born by Caesarean section at 35 weeks and 3 days gestation. At 24-days-old he had a fever and localized swelling of the groin to the femur. By ultrasonography (US) and computed tomography (CT), the swelling was diagnosed as iliopsoas abscess. We treated him through percutaneous needle drainage and antibiotics. Methicillin-resistant Staphylococcus aureus (MRSA) was detected in the culture of the fluid from the abscess and the urine. US and CT were useful for the diagnosis and provided guidance for the needle puncture and follow-up of the iliopsoas abscess.

The predominant contribution of oligopeptide transporter PepT1 to intestinal absorption of beta-lactam antibiotics in the rat small intestine

Although recent evidence suggests that certain beta-lactam antibiotics are absorbed via a specific transport mechanism, its nature is unclear. To confirm whether peptide transport in the rat can be largely ascribed to the intestinal oligopeptide transporter PepT1, the transporter has been functionally characterized and its significance in the intestinal absorption of beta-lactam antibiotics was evaluated. For evaluation of transport activity complementary RNA (cRNA) of rat PepT1 was synthesized in-vitro and expressed in Xenopus laevis oocytes. cRNA induced uptake of several beta-lactam antibiotics and the dipeptide [14C]glycylsarcosine; this was specifically inhibited by various dipeptides and tripeptides but not by their constituent amino acids or by tetra- or pentapeptides. The transport activity of PepT1 for beta-lactam antibiotics correlated well with their in-vivo intestinal transport and absorption. Furthermore, mutual inhibitory effects on uptake were observed between glyclsarcosine and beta-lactam antibiotics. Hybrid depletion of the functional expression of rat PepT1 in oocytes injected with rat intestinal epithelial total mRNA was studied using an antisense oligonucleotide corresponding to the 5'-coding region of PepT1. In oocytes injected with rat mRNA pre-hybridized with the antisense oligonucleotide against rat PepT1, the uptake of [14C]glycylsarcosine was almost completely abolished, whereas its uptake was not influenced by a sense oligonucleotide for the same region of PepT1. Similarly, the uptake of beta-lactam antibiotics was also reduced by the antisense oligonucleotide against rat PepT1. These results demonstrate that the intestinal proton-coupled oligopeptide transporter PepT1 plays a predominant role in the carrier-mediated intestinal absorption of beta-lactam antibiotics and native oligopeptides in the rat.

[Assessment of ventricular wall motion and volume by fast cine MRI using Fastcard sequence]

Left ventricular wall motion and volume are important factors for assessment of cardiac function. Recent advances in magnetic resonance imaging(MRI) have allowed fast cine MR sequences. Fastcard sequence is an electrocardiographically triggered gradient echo sequence with k-space segmentation and have enabled fast cine acquisition of the heart during breath holding. Improvement in image quality and contrast between myocardium and intraventricular cavity may facilitate assessment of cardiac function using the phased array coil. Drug stress MRI for detection of significant coronary artery stenosis could be more easily performed by this sequence than conventional cine MR sequences. Sequential short axis images obtained with Fastcard sequence also provide an accurate method without assumption of ventricular shape.

Quantification of glycated hemoglobin by electrospray ionization mass spectrometry

Glycated hemoglobin, considered to be the best index for the treatment of diabetes mellitus, was measured by electrospray ionization mass spectrometry (ESI/MS) according to the method proposed by Morris et al. at the 44th ASMS Conference on Mass Spectrometry and Allied Topics, 1996. They compared the values obtained by MS and affinity chromatography. Here, the values obtained by ESI/MS were compared with those obtained by high-performance liquid chromatography and by latex agglutination immunoassay. Whole blood samples were diluted 500 fold with 0.2% formic acid-50% acetonitrile solution and 5 microliters of the diluted solution was injected with the ESI/MS system (TSQ 7000) via a sample loop. The within-run and between-run relative standard deviations of the ratio of glycated and non-glycated beta-chain were less than 5%. The correlation coefficients between ESI/MS and conventional methods were higher than 0.96. However, considerable discrepancies were observed among methods. ESI/MS will allow reproducible measurements of glycated hemoglobin and will be useful in the quality control of HbA1c measurement by other principles and also in routine clinical laboratory tests.

Purification, cDNA cloning, and characterization of a new serpin with megakaryocyte maturation activity

A new member of the serine protease inhibitor (serpin) superfamily with megakaryocyte maturation activity was purified, and its cDNA was cloned and characterized. The predicted amino acid sequence consisting of 380 residues was unique and was 38% identical to the serpin plasminogen activator inhibitor type 2 (PAI-2). The recombinant factor expressed in Chinese hamster ovary cells showed species-specific activity on the induction of megakaryocyte maturation in vitro. When injected into mice, the factor indeed elicited an increase in the number of platelets in plasma. The sequence alignment indicated that the factor possessed a lysine residue at the P1 position, suggesting that it might function as an inhibitor of Lys-specific proteases. Although we could not show any inhibitory activities toward several known Lys-specific proteases, we detected the activity toward protease activity present in the culture supernatant of COLO 201 cells. These results suggested that the protein might influence the maturation of megakaryocytes via action as a serpin.

Anti-tumor promoting activities of lantadenes on mouse skin tumors and mouse hepatic tumors

Two-stage carcinogenesis of mouse skin papillomas induced by 7,12-dimethylbenz[alpha]anthracene and 12-O-tetradecanoylphorbol 13-acetate, and mouse hepatic tumors induced by N-nitrosodiethylamine and phenobarbital, were inhibited by lantadenes.

Experimental hepatitis in neonatally thymectomized mice: transfer of disease and the role of T cells

Using neonatally A/J thymectomized mice, we have produced chronic hepatitis by administration of sublethal doses of Propionibacterium acnes and lipopolysaccharide (LPS). Our goal in this unique model was to evaluate the effector cell population required to generate chronic hepatitis by transferring spleen cells or splenic subpopulations derived from donor thymectomized mice with chronic hepatitis into congenic recipient nonimmunized thymectomized or sham-thymectomized animals. Several key observations were made regarding the ability to induce and to transfer disease. First, an inflammatory liver injury in neonatally thymectomized (NTx) mice was readily generated using sublethal doses of P. acnes and LPS. Second, the lesions were persistent and associated with the production of autoantibodies to liver-specific lipoprotein and anti-nuclear antibodies. Third, these features were not found in comparably injected nonthymectomized control A/J mice. Fourth, the same liver injury was transferred to neonatally thymectomized but otherwise naive mice by the transfer of donor spleen cells from affected mice previously induced to develop experimental hepatitis. Fifth, the transfer of this liver injury could not be achieved using T-cell-depleted spleen cells. Deletion of CD4+ T cells or CD8+ T cells by sensitized spleen cells resulted in suppression of the transferred liver injury. In contrast, transfer of nylon wool adherent splenic T cells induced severe hepatitis. These data suggest that the chronic liver injury induced in NTx mice by administration of P. acnes and LPS involves a breakdown in tolerance accompanied by the appearance of autoantibodies and that nylon wool adherent CD4+ and CD8+ T cells play important roles in the modulation of liver injury.

[Vitamin K deficiency syndrome caused by antituberculous agents]

Vitamin K deficiency caused by antituberculous agents was examined in clinical patients and in experimental rats. When antituberculous agents given to the patients who had only total elental diet because of small intestinal dysfunction, a marked increase in plasma PIVKA-II and a decrease in thrombo-test value were observed. These changes were quickly normalized by administration of vitamin K, despite of succeeding or stopping of antituberculous agents. In rat experiments, effects of four agents (ethambutol, isoniazid, paraaminosalicylate, and rifampicin) on prothrombin time were studied. Among these agents, only rifampicin prolonged prothrombin time. This prolongation depended on drug doses and duration of administration. In addition to this hypoprothrombinemia, an increase in plasma PIVKA-II was also observed, and these changes were normalized within 24 hours of vitamin K administration. These data suggest that rifampicin inhibits vitamin K epoxide reductase interfering re-use of vitamin K and caused vitamin K deficiency in patients with total elental diet.

Significance of telomerase activity in the diagnosis of small differentiated hepatocellular carcinoma

Precise diagnosis of well-differentiated hepatocellular carcinoma (HCC) is sometimes difficult to establish. Telomerase activity was examined by telomeric-repeat-amplification protocol (TRAP) in 37 HCC nodules smaller than 3 cm in diameter, including 24 fine-needle-aspiration biopsy specimens, 22 non-tumor chronic-liver-disease tissues (9 chronic hepatitis and 13 liver cirrhosis) and 3 normal liver tissues. Telomerase activity was assayed by serially diluted samples and quantitated by using an internal telomerase assay standard (ITAS). Telomerase activity was detected in all HCC and in 11 of 22 non-tumor chronic-liver-disease tissues. Normal liver samples had undetectable telomerase activity. Cut-off level of telomerase activity for its practical usage in HCC diagnosis was tentatively set for 0.6 microg liver protein/assay at 10-cell equivalent activity of a gastric-cancer cell line, MKN-1. This level was twice the highest activity in non-tumor chronic liver disease therefore, telomerase activity in all non-tumor liver samples was below this level. The telomerase-positive incidence exceeding this cut-off level was 73% (11/15) in well-differentiated HCC, 94% (16/17) in moderately differentiated HCC and 100% (5/5) in poorly differentiated HCC. Well-differentiated HCC showed low positivity by other diagnostic markers. 21% by AFP, 0% by PIVKA-II and 13% by angiography. The detection of telomerase activity may thus be a useful additional tool for precise and early diagnosis of small differentiated HCC, even when diagnosis is inconclusive by conventional techniques.

Cloning of a mRNA preferentially expressed in chondrocytes by differential display-PCR from a human chondrocytic cell line that is identical with connective tissue growth factor (CTGF) mRNA

Chondrocyte- or chondrosarcoma cell line (HCS)-specific DNA fragments were obtained using differential display-PCR. Nucleotide sequences of 32 species derived from HCS cells were determined. One of the sequence tags (tag no. 24) corresponded to the nucleotide sequence of connective tissue growth factor (CTGF). Northern blot analysis showed that CTGF was highly expressed in HCS cells and rabbit growth cartilage cells in culture but was not expressed in osteoblastic cells in culture. In situ hybridization revealed that CTGF was expressed only in the hypertrophic chondrocytes of costal cartilage and the vertebral column in embryonic mice. The expression of CTGF in HCS cells was up-regulated by the addition of TGF-beta or BMP-2. These findings suggest that CTGF participates in endochondral ossification.

'Green mice' as a source of ubiquitous green cells

The green fluorescent protein (GFP) is responsible for the green bioluminescence of the jellyfish Aequorea victoria. Many classes of GFP mutants exist that display modified fluorescence spectra and an increased extinction coefficient. We produced transgenic mouse lines with an 'enhanced' GFP (EGFP) cDNA under the control of a chicken beta-actin promoter and cytomegalovirus enhancer. All of the tissues from these transgenic lines, with the exception of erythrocytes and hair, were green under excitation light. The fluorescent nature of the cells from these transgenic mouse lines would facilitate their use in many kinds of cell transplantation experiments.

The first Japanese case of Hb Santa Ana, an unstable abnormal hemoglobin, identified rapidly by electrospray ionization mass spectrometry

Two members of a family had chronic hemolytic anemia due to unstable hemoglobin. The abnormal beta-chain with a molecular weight of 16 u smaller than the normal beta-chain was found within 5 minutes by analysis using electrospray ionization mass spectrometry. The substitution of amino acid was also determined rapidly by this new strategy. The leucine at the 88th position of the normal beta-chain was substituted by proline in the hemoglobin as in Hb Santa Ana. This is the first report of a Japanese case of Hb Santa Ana; the clinical course was similar to that in the previously reported cases.

Electron-beam CT angiography for thoracic aortic aneurysm and dissection: application of continuous volume scan and electrocardiographically triggered scan

PURPOSE

To assess the diagnostic value of CT angiography of thoracic aortic aneurysm and dissection with electron-beam CT.

MATERIALS AND METHODS

Electron-beam CT angiography was used for the evaluation of thoracic aortic aneurysm (n = 15), and aortic dissection (n = 15). Continuous volume scan (CVS), permitted by continuous X-ray exposure with table incrementation, was performed in all patients. An additional electrocardiographically triggered scan was obtained in four patients. Three-dimensional surface display and multiplanar reformations were obtained and compared with digital subtraction angiography.

RESULTS

Motion artifacts and the resulting degradation of three-dimensional image quality were frequent in the ascending aorta of CVS images. Electrocardiographically triggered sections improved the image quality of the ascending aorta. In the aortic arch and descending aorta, excellent three-dimensional images competitive in quality with digital subtraction angiography were obtained in all patients. For patients with aortic dissection, multiplanar reformation was useful to demonstrate the intimal flap and entry sites.

CONCLUSION

The use of electron-beam CT angiography is feasible for the diagnosis of thoracic aortic aneurysm and dissection.

Significance of telomerase activity in the diagnosis of small differentiated hepatocellular carcinoma

Precise diagnosis of well-differentiated hepatocellular carcinoma (HCC) is sometimes difficult to establish. Telomerase activity was examined by telomeric-repeat-amplification protocol (TRAP) in 37 HCC nodules smaller than 3 cm in diameter, including 24 fine-needle-aspiration biopsy specimens, 22 non-tumor chronic-liver-disease tissues (9 chronic hepatitis and 13 liver cirrhosis) and 3 normal liver tissues. Telomerase activity was assayed by serially diluted samples and quantitated by using an internal telomerase assay standard (ITAS). Telomerase activity was detected in all HCC and in 11 of 22 non-tumor chronic-liver-disease tissues. Normal liver samples had undetectable telomerase activity. Cut-off level of telomerase activity for its practical usage in HCC diagnosis was tentatively set for 0.6 microg liver protein/assay at 10-cell equivalent activity of a gastric-cancer cell line, MKN-1. This level was twice the highest activity in non-tumor chronic liver disease therefore, telomerase activity in all non-tumor liver samples was below this level. The telomerase-positive incidence exceeding this cut-off level was 73% (11/15) in well-differentiated HCC, 94% (16/17) in moderately differentiated HCC and 100% (5/5) in poorly differentiated HCC. Well-differentiated HCC showed low positivity by other diagnostic markers. 21% by AFP, 0% by PIVKA-II and 13% by angiography. The detection of telomerase activity may thus be a useful additional tool for precise and early diagnosis of small differentiated HCC, even when diagnosis is inconclusive by conventional techniques.

A case of uterine choriocarcinoma with spontaneous rupture twenty-three years following the antecedent pregnancy

A 53-year-old woman went into shock with a spontaneous uterine rupture due to choriocarcinoma that occurred 23 years after an elective abortion in the first trimester, and she underwent an emergency hysterectomy. After 4 courses of uneventful postoperative chemotherapy, she suffered from severe pneumonia. Fortunately, however, she recovered and has remained in complete remission at 2.5 years follow-up. This is a case of uterine choriocarcinoma with a spontaneous rupture after the longest latent period yet reported.

Effects of all-trans retinoic acid on choriocarcinoma cells in vitro

OBJECTIVES

To determine the activities of all-trans retinoic acid (RA) on choriocarcinoma cells in vitro.

METHODS

The antiproliferative effect of all-trans RA on 4 choriocarcinoma cell lines was measured by the MTT assay. The effect of all-trans RA combined with methotrexate or actinomycin-D was then examined. The effect of all-trans RA on hCG secretion was also studied. The gene expression of retinoic acid receptors (RARs) was examined by RT-PCR.

RESULTS

All-trans RA inhibited cell proliferation dose- and time-dependently; a 6-day exposure to 1 microM all-trans RA suppressed the cell growth by 67.8%-82.0% compared to the controls. An enhanced effect was observed in the combined administration of all-trans RA and methotrexate or actinomycin-D. The secretion of hCG increased 4-fold to 9-fold by the addition of 1 microM all-trans RA. RARs genes were expressed in all cell lines.

CONCLUSION

The anticancer activity presented here appears to warrant further evaluation of all-trans RA as adjuvant therapy for choriocarcinoma.

An unusual clinical course after mole evacuation: a case report

A 27-year-old woman evacuated a hydatidiform mole at 11 weeks of gestation. Her serum human chorionic gonadotropin (hCG) levels declined progressively but reached a plateau of 2-3 mIU/ml thereafter. The patient was treated with two courses of methotrexate, which did not affect her hCG levels. She refused further chemotherapy and, for more than one year, she was managed expectantly until a significant rise in her hCG titer. Fortunately, an unexpected pregnancy and subsequent missed abortion led to a spontaneous regression of her hCG levels.