[Persectives on postgenome medicine: Gene therapy for liver cirrhosis]

Liver cirrhosis is the irreversible end result of chronic liver disease, characterized by diffuse disorganization of the normal hepatic structure of regenerative nodules and fibrotic tissue. It is associated with prominent morbidity and mortality, and is induced by many factors. The ideal strategy for the treatment of liver cirrhosis should include prevention of fibrogenesis, stimulation of hepatocyte mitosis, and reorganization of the liver architecture. We have developed a novel gene therapy approach for rat liver cirrhosis by muscle-directed gene transfer of hepatocyte growth factor(HGF). HGF gene transduction inhibited fibrogenesis and hepatocyte apoptosis, and also produced resolution of fibrosis in the cirrhotic liver. Thus, HGF gene therapy may be potentially useful for the treatment of patients with liver cirrhosis, which is otherwise fatal and untreatable by conventional therapy.

HVJ-liposome-mediated transfection of HSVtk gene driven by AFP promoter inhibits hepatic tumor growth of hepatocellular carcinoma in SCID mice

Suicide gene therapy using ganciclovir (GCV) with transfection of the herpes thymidine kinase (HSVtk) gene has been studied for cancer therapy. The present study demonstrates an efficient method of suicide gene therapy for multiple hepatic tumors, involving repetitive transfection of the HSVtk gene driven by the alpha-fetoprotein (AFP) promoter using hemagglutinating virus of Japan (HVJ)-liposomes. AFP-producing cells (HUH7) and AFP-nonproducing cells (LS180) were injected subcutaneously (s.c.) to establish tumors in nude mice. Two plasmid constructs, bacterial LacZ gene driven by the AFP promoter (AFPLacZ), and HSVtk gene driven by the AFP promoter (AFPTK1) were encapsulated into the HVJ-liposome and used. When AFPLacZ was injected into the s.c. tumors, expression of LacZ gene was confined to HUH7 tumors. Repeated transfection of AFPTK1 followed by GCV treatment markedly suppressed growth of HUH7 tumors, and apoptosis of HUH7 cells was recognized in the tumor. Next, HUH7 cells were injected into the portal vein in severe combined immunodeficiency mice to establish a hepatic tumor model. After inoculation with the tumor, HVJ-liposomes containing the AFPTK1 plasmid vector were injected into the portal vein via the splenic hilum, followed by GCV treatment. This gene therapy significantly inhibited the growth of tumors in the liver and markedly improved survival. Three injections of the AFPTK1 plasmid vector completely inhibited tumor growth. This procedure seems to have great potential for the treatment of multiple hepatic tumors.

Carcinoma of the ampulla of Vater associated with or without adenoma: a clinicopathologic analysis of 198 cases with reference to p53 and Ki-67 immunohistochemical expressions

Adenomatous areas are found frequently within or in the vicinity of carcinoma of the ampulla of Vater. This makes definite diagnosis difficult in the preoperative examination. The adenoma-carcinoma development hypothesis is generally accepted for colorectal tumors. Recently, a genetic alteration model during colorectal tumor development has attracted much attention, leading to various studies. We studied clinicopathologic features, prognostic factors, and the alteration of the p53 tumor suppressor gene using p53 immunohistochemical staining in pure adenomas, pure carcinomas, and carcinomas with adenomatous areas. A proliferative activity of the tumors using Ki-67 was also evaluated. Nine cases of pure adenoma and 198 cases of carcinoma of the ampulla of Vater were selected for this study. Among the 198 cases of thecarcinoma, 83 cases (42%) had adenomatous areas. Positivity of p53 immunohistochemical staining was 0% in pure adenomas, 36% in the adenomatous areas of carcinomas with adenomatous areas and 62% in the carcinomatous areas of carcinomas with adenomatous areas, and 56% in pure carcinoma. Accumulation of p53 protein and the Ki-67 labeling index revealed no significant difference in prognosis. The clinicopathological factors examined were as follows: degree of invasion of the surrounding tissue, such as duodenal wall; pancreatic parenchyma; the presence or absence of lymphatic permeation; venous invasion; perineural invasion; the presence of regional lymph node metastasis; and TNM stage. Each of the clinicopathological factors showed a significant difference. Multivariate analysis revealed strong predictors for a worse prognosis: presence of lymphatic permeation, invasion of the pancreas, and perineural invasion. In conclusion, our results are consistent with the adenoma--carcinoma development hypothesis. It would seem that the molecular events leading to p53 accumulation in neoplasms of the ampulla of Vater occur relatively late during the oncogenetic process. Moreover, we think it may be useful to refer to the p53 overexpression in the diagnosis of ampullary tumors.

Exclusive expression of transketolase in the vanadocytes of the vanadium-rich ascidian, Ascidia sydneiensis samea

Ascidians, especially those belonging to the Ascidiidae, are known to accumulate extremely high levels of vanadium in vanadocytes, one type of blood (coelomic) cell. Vanadium, which exists in the +5 oxidation state in seawater, is accumulated in the vanadocytes and reduced to the +3 oxidation state. We have been trying to characterize all of the polypeptides specific to vanadocytes and to specify the proteins that participate in the accumulation and reduction of vanadium. To date, we have localized three enzymes in vanadocytes: 6-phosphogluconate dehydrogenase (6-PGDH: EC 1.1.1.44), glucose-6-phosphate dehydrogenase (G6PDH: EC 1.1.1.49), and glycogen phosphorylase (GP: EC 2.4.1.1), all of which are involved in the pentose phosphate pathway. In the current study, we cloned a cDNA for transketolase, an essential and rate-limiting enzyme in the non-oxidative part of the pentose phosphate pathway, from vanadocytes. The cDNA encoded a protein of 624 amino acids, which showed 61.8% identity to the human adult-type transketolase gene product. By immunocytochemistry and immunoblot analyses, the transketolase was revealed to be a protein that was expressed only in vanadocytes and not in any of the more than ten other types of blood cell. This finding, taken together with the localized expression of the other three enzymes, strongly supports the hypothesis that the pentose phosphate pathway functions exclusively in vanadocytes.

Crystal structure of N-carbamyl-D-amino acid amidohydrolase with a novel catalytic framework common to amidohydrolases

BACKGROUND

N-carbamyl-D-amino acid amidohydrolase (DCase) catalyzes the hydrolysis of N-carbamyl-D-amino acids to the corresponding D-amino acids, which are useful intermediates in the preparation of beta-lactam antibiotics. To understand the catalytic mechanism of N-carbamyl-D-amino acid hydrolysis, the substrate specificity and thermostability of the enzyme, we have determined the structure of DCase from Agrobacterium sp. strain KNK712.

RESULTS

The crystal structure of DCase has been determined to 1.7 A resolution. The enzyme forms a homotetramer and each monomer consists of a variant of the alpha + beta fold. The topology of the enzyme comprises a sandwich of parallel beta sheets surrounded by two layers of alpha helices, this topology has not been observed in other amidohydrolases such as the N-terminal nucleophile (Ntn) hydrolases.

CONCLUSIONS

The catalytic center could be identified and consists of Glu46, Lys126 and Cys171. Cys171 was found to be the catalytic nucleophile, and its nucleophilic character appeared to be increased through general-base activation by Glu46. DCase shows only weak sequence similarity with a family of amidohydrolases, including beta-alanine synthase, aliphatic amidases and nitrilases, but might share highly conserved residues in a novel framework, which could provide a possible explanation for the catalytic mechanism for this family of enzymes.

Hepatocyte growth factor promotes migration of human hepatocellular carcinoma via phosphatidylinositol 3-kinase

Hepatocyte growth factor (HGF) is known to be a potent mitogen and motogen for epithelial cells. Hepatocellular carcinoma (HCC) often metastasizes, and the c-Met/HGF receptor is highly expressed by HCC cells. The aim of this study was to investigate the signaling pathways associated with the motogenic effect of HGF on HCC cells via c-Met. HCC cell lines (Hep3B, HepG2, PLC, and Huh-7) and HCC cells harvested from patients were used for the Boyden chamber assay of chemotactic activity as well as for immunoprecipitation and immunoblotting studies. HGF stimulated the motility of Hep3B, HepG2, and Huh-7 cells in a dose-dependent manner in association with tyrosine phosphorylation of c-Met and activation of phosphatidylinositol 3-kinase (PI3-K). A tyrosine kinase inhibitor (genistein) and a PI3-K inhibitor (wortmannin) prevented the migration of HCC cells. However, migration was not prevented by calphostin C, an inhibitor of protein kinase C (PKC), which is a downstream target of phospholipase Cgamma (PLCgamma). HGF also stimulated the migration of HCC cells obtained from three patients, while wortmannin prevented the migration of these cells. These results indicate that HGF stimulates the migration of HCC cells through the tyrosine phosphorylation of c-Met via activation of PI3-K.

Hypermethylation of multiple genes in pancreatic adenocarcinoma

Hypermethylation of CpG islands is a common mechanism by which tumor suppressor genes are inactivated. We studied 45 pancreatic carcinomas and 14 normal pancreata for aberrant DNA methylation of CpG islands of multiple genes and clones using methylation-specific PCR (MSP) and bisulfite-modified sequencing. Using MSP, we detected aberrant methylation of at least one locus in 60% of carcinomas. The genes analyzed included RARbeta (methylated in 20%), p16 (18%), CACNA1G (16%), TIMP-3 (11%), E-cad (7%), THBS1 (7%), hMLH1 (4%), DAP kinase (2%), and MGMT (0%). In addition, aberrant methylation was found in three CpG islands (MINT31, -1, and -2) in 38, 38, and 14% of carcinomas, respectively. Hypermethylation was largely confined to the carcinomas with only three loci (E-cad, DAP kinase, and MINT2) harboring methylation in some normal pancreata (36, 21, and 14%, respectively). Simultaneous methylation of at least four loci was observed in 5 of 36 (14%) pancreatic adenocarcinomas. We defined this subgroup of pancreatic adenocarcinomas as "CpG island-methylator-phenotype positive (CIMP+)." Two of four carcinomas with microsatellite instability harbored promoter hypermethylation of hMLH1, and both cases were CIMP+. Thus, we conclude that many pancreatic carcinomas hypermethylate a small percentage of genes, whereas a subset displays a CIMP+ phenotype.

Differentially expressed mRNAs in androgen-independent but not androgen-dependent Shionogi carcinoma

Recently, a new and highly effective method termed suppressive subtractive hybridization (SSH) has been introduced to clone differentially expressed mRNAs. Genes expressed in androgen-independent but not in androgen-dependent tumors, and vice versa, are obviously significant to delineate the mechanisms of androgen dependency/independency of these tumors. Mouse mammary cancer (Shionogi carcinoma-115) has been extensively used to analyze the mechanism of androgen-dependent cancer growth.

METHODS

We cloned androgen-independent and androgen-dependent Shionogi carcinoma-115 specific mRNAs by the SSH method. Cloned sequences were compared with known sequences using NCBI BLAST across the Internet. Two clones were positive for cDNA insert when androgen-independent cDNA was used as tester cDNA, while no clones were positive using the androgen-dependent tester cDNA. One of the former was mouse protein kinase C beta-II while the other was a new DNA sequence. Mouse protein kinase C beta-II mRNA and the new mRNA were shown to be differentially expressed by RT-PCR analysis in androgen-independent but not androgen-dependent Shionogi carcinoma. Two mRNA species differentially expressed in androgen-independent but not androgen-dependent Shionogi carcinoma were cloned by the SSH method. The significance of these mRNAs for androgen-dependency/independency of Shionogi carcinoma should be explained in future studies.

X-ray structure of beta-carbonic anhydrase from the red alga, Porphyridium purpureum, reveals a novel catalytic site for CO(2) hydration

The carbonic anhydrases (CAs) fall into three evolutionarily distinct families designated alpha-, beta-, and gamma-CAs based on their primary structure. beta-CAs are present in higher plants, algae, and prokaryotes, and are involved in inorganic carbon utilization. Here, we describe the novel x-ray structure of beta-CA from the red alga, Porphyridium purpureum, at 2.2-A resolution using intrinsic zinc multiwavelength anomalous diffraction phasing. The CA monomer is composed of two internally repeating structures, being folded as a pair of fundamentally equivalent motifs of an alpha/beta domain and three projecting alpha-helices. The motif is obviously distinct from that of either alpha- or gamma-CAs. This homodimeric CA appears like a tetramer with a pseudo 222 symmetry. The active site zinc is coordinated by a Cys-Asp-His-Cys tetrad that is strictly conserved among the beta-CAs. No water molecule is found in a zinc-liganding radius, indicating that the zinc-hydroxide mechanism in alpha-CAs, and possibly in gamma-CAs, is not directly applicable to the case in beta-CAs. Zinc coordination environments of the CAs provide an interesting example of the convergent evolution of distinct catalytic sites required for the same CO(2) hydration reaction.

Effect of Bcl-2 overexpression in human prostate cancer cells in vitro and in vivo

BACKGROUND

Cancer cells often develop mechanisms to resist apoptosis and the extent of such anti-apoptotic ability has been shown to parallel tumor progression in various malignancies. Among various molecules implicated in regulating apoptosis pathway, bcl-2 and its family members are best characterized.

METHODS

To investigate the effect of bcl-2-mediated anti-apoptotic ability on tumor growth and progression in prostate cancer, a cell line overexpressing bcl-2 (LNCaP/bcl-2) was established by genetically engineering a prostate cancer cell line LNCaP. Tumor growth of LNCaP/bcl-2 was compared with the parental cell line in vitro and in vivo.

RESULTS

LNCaP/bcl-2 cells show resistance to apoptosis caused by nutrient deprivation and did not arrest when cultured in serum-free or androgen-free medium, while parental LNCaP cells or LNCaP cells transfected with the vector only (LNCaP/control) underwent extensive apoptosis on nutrient deprivation and sustained growth suppression in serum-free or androgen-free medium. When injected subcutaneously into nude mice, tumors deriving from LNCaP/bcl-2 cells grew faster compared with LNCaP/control for about 3 weeks (P = 0.02), but this effect was not evident after 5 weeks. Upon castration, the control tumors regressed but LNCaP/bcl-2-derived tumors showed resistance, as was previously reported.

CONCLUSIONS

These data confirm the notion that anti-apoptotic function of bcl-2 is oncogenic and confers resistance to androgen deprivation and also indicate that it may also play a critical role in earlier stages of tumorigenesis.

CD95 ligand expression enhances growth of murine renal cell carcinoma in vivo

The CD95/CD95 ligand (CD95L) system plays an important role in the induction of lymphoid apoptosis and has been implicated in the suppression of immune responses. In this system, two murine CD95L-transfected renca clones and a control renca clone transfected only with the vector were implanted into the subcapsule of the left kidney of Balb/c and Balb/c nude mice. Both CD95L-expressing and control renca clones formed macroscopic tumors in all of the Balb/c and Balb/c nude hosts 14 days after implantation. Growth of tumors of murine CD95L-transfected renca cells was significantly better than that of control renca cells in Balb/c mice, while the growth advantage of CD95L transfectants was not observed in Balb/c nude mice. Lymphocytes underwent apoptosis mainly in the periphery of the CD95L-expressing tumors but not in control tumors grown in Balb/c mice, while lymphocytes undergoing apoptosis were not observed in CD95L-expressing tumors or in control tumors grown in Balb/c nude mice. Neutrophilic recruitment was rarely observed in CD95L-expressing or control tumors. CD95L expressed on renca cells possibly suppressed immune responses against renca tumors by inducing apoptosis of the infiltrating lymphocytes. However, CD95L-expressing renca cells did not form tumors in the renal subcapsule of allogeneic C3H/HeJ mice.

PTEN/MMAC1 mutations in hepatocellular carcinomas: somatic inactivation of both alleles in tumors

Allelic loss of loci on chromosome 10q occurs frequently in hepatocellular carcinomas. Somatic mutations of the PTEN/MMAC1 gene on this chromosome at 10q23 were recently identified in sporadic cancers of the uterus, brain, prostate and breast. To investigate the potential role of PTEN/MMAC1 gene in the genesis of hepatocellular carcinomas, we examined 96 tumors for allelic loss on 10q and also for subtle mutations anywhere within the coding region of PTEN/MMAC1 gene. Allelic loss was identified in 25 of the 89 (27%) tumors that were informative for polymorphic markers in the region. Somatic mutations were identified in five of those tumors: three frameshift mutations, a 1-bp insertion at codon 83-84 in exon 4 and two 4-bp deletions, both at codon 318-319 in exon 8; two C-to-G transversion mutation, both at -9 bp from the initiation codon in the 5' non-coding region of exon 1. No missense mutation was observed in this panel of tumors. In most of the informative tumors carrying intragenic mutations of one allele, we were able to detect loss of heterozygosity as well. These findings suggest that two alleles of the PTEN/MMAC1 gene may be inactivated by a combination of intragenic point mutation on one allele and loss of chromosomal material on the other allele in some of these tumors.

Utilization of variant-type of human alpha-fetoprotein promoter in gene therapy targeting for hepatocellular carcinoma

We previously reported that the retroviral vector (LNAFW0.3TK) expressing the herpes simplex thymidine kinase (HSVtk) gene under the control of the 0.3 kb human alpha-fetoprotein (AFP) promoter provided the ganciclovir (GCV)-mediated cytotoxicity in the high AFP-producing (HuH-7) but not in the low AFP-producing (huH-1/cl.2) human hepatoma cells. In the present study, we constructed the retroviral vector (LNAFM0.3TK) in which the HSVtk gene expression is regulated by the variant-type of the 0.3 kb human AFP promoter with a G-to-A substitution at nucleotide -119, a point mutation responsible for hereditary persistence of human AFP and the vector was applied to three human hepatoma cell lines HuH-7, huH-1/cl.2 and intermediate AFP-producing cells (PLC/PRF/5). By the reporter gene transfection assay, the activity of the variant-type of the promoter was much higher than that of the wild-type of the promoter in both HuH-7 and huH-1/cl.2 cells. Consistent with this, LNAFM0.3TK infection could sensitize huH-1/cl.2 cells, as well as HuH-7 and PLC/PRF/5 cells to GCV, but did not affect cell growth of nonhepatoma cells (HeLa). In addition, the bystander effect was achieved more efficiently by LNAFM0.3TK infection than LNAFW0.3TK infection in HuH-7 cells. These results suggest that the variant-type of the human AFP promoter ensures the therapeutic gene expression in gene therapy particularly for the low AFP-producing hepatoma cells.

Development of cephalic neural crest cells in embryos of Lampetra japonica, with special reference to the evolution of the jaw

Neural crest cells contribute extensively to vertebrate head morphogenesis and their origin is an important question to address in understanding the evolution of the craniate head. The distribution pattern of cephalic crest cells was examined in embryos of one of the living agnathan vertebrates, Lampetra japonica. The initial appearance of putative crest cells was observed on the dorsal aspect of the neural rod at stage 20.5 and ventral expansion of these cells was first seen at the level of rostral somites. As in gnathostomes, cephalic crest cells migrate beneath the surface ectoderm and form three major cell populations, each being separated at the levels of rhombomeres (r) 3 and r5. The neural crest seems initially to be produced at all neuraxial levels except for the rostral-most area, and cephalic crest cells are secondarily excluded from levels r3 and r5. Such a pattern of crest cell distribution prefigures the morphology of the cranial nerve anlage. The second or middle crest cell population passes medial to the otocyst, implying that the otocyst does not serve as a barrier to separate the crest cell populations. The three cephalic crest cell populations fill the pharyngeal arch ventrally, covering the pharyngeal mesoderm laterally with the rostral-most population covering the premandibular region and mandibular arch. The third cell population is equivalent to the circumpharyngeal crest cells in the chick, and its influx into the pharyngeal region precedes the formation of postotic pharyngeal arches. Focal injection of DiI revealed the existence of an anteroposterior organization in the neural crest at the neurular stage, destined for each pharyngeal region. The crest cells derived from the posterior midbrain that express the LjOtxA gene, the Otx2 cognate, were shown to migrate into the mandibular arch, a pattern which is identical to gnathostome embryos. It was concluded that the head region of the lamprey embryo shares a common set of morphological characters with gnathostome embryos and that the morphological deviation of the mandibular arch between the gnathostomes and the lamprey is not based on the early embryonic patterning.

Glucolipsin A and B, two new glucokinase activators produced by Streptomyces purpurogeniscleroticus and Nocardia vaccinii

During the screening of the natural products for their ability to increase the activity of glucokinase by relieving inhibition by long chain fatty acyl CoA esters (FAC), two novel compounds, glucolipsin A (1) and B (2) were isolated from the butanol extracts of Streptomyces purpurogeniscleroticus WC71634 and Nocardia vaccinii WC65712, respectively. The structures of these two compounds were established by spectroscopic methods and chemical degradation. Glucolipsin A (1) and B (2) relieved the inhibition of glucokinase by FAC with RC50 values of 5.4 and 4.6 microM.

Semiquantitative evaluation of alpha1A-adrenoceptor subtype mRNA in human hypertrophied and non-hypertrophied prostates: regional comparison

The main purpose of this study was to compare semiquantitatively the amount of alpha1a-adrenoceptor subtype mRNA in urethral, central and peripheral areas in benign hypertrophied prostates and non-hypertrophied prostate by the competitive reverse transcriptase polymerase chain reaction (RT-PCR) method. Prostates from twenty cases of men with benign prostatic hypertrophy (BPH) and 5 cases of bladder tumor without BPH were obtained for this study. The mRNA was extracted from the urethral, central and peripheral areas of each prostate, and quantitative RT-PCR was performed using the ratio of PCR product of alpha1a-adrenoceptor mRNA/beta2-microglobulin mRNA. The ratio for the central area of the hypertrophied prostate was significantly greater than that for the same area of the non-hypertrophied prostate (p < 0.05). In contrast, the urethral area showed no significant difference between the two prostate conditions. The central area of the hypertrophied prostate showed the tendency to have an increased alpha1a-adrenoceptor mRNA level compared with the urethral area, though no statistical difference was recognized because of the high standard error. Regional differences in the alpha1a-adrenoceptor mRNA in the non-hypertrophied prostate were rarely observed. The present finding demonstrates that the increased alpha1a-adrenoceptor mRNA content found in the hypertrophied prostate (1) was due to that in the central area.

Hepatocyte growth factor gene therapy of liver cirrhosis in rats

Liver cirrhosis is the irreversible end result of fibrous scarring and hepatocellular regeneration, characterized by diffuse disorganization of the normal hepatic structure of regenerative nodules and fibrotic tissue. It is associated with prominent morbidity and mortality, and is induced by many factors, including chronic hepatitis virus infections, alcohol drinking and drug abuse. Hepatocyte growth factor (HGF), originally identified and cloned as a potent mitogen for hepatocytes, shows mitogenic, motogenic and morphogenic activities for a wide variety of cells. Moreover, HGF plays an essential part in the development and regeneration of the liver, and shows anti-apoptotic activity in hepatocytes. In a rat model of lethal liver cirrhosis produced by dimethylnitrosamine administrations, repeated transfections of the human HGF gene into skeletal muscles induced a high plasma level of human as well as enodogenous rat HGF, and tyrosine phosphorylation of the c-Met/HGF receptor. Transduction with the HGF gene also suppressed the increase of transforming growth factor-beta1 (TGF-beta1), which plays an essential part in the progression of liver cirrhosis, inhibited fibrogenesis and hepatocyte apoptosis, and produced the complete resolution of fibrosis in the cirrhotic liver, thereby improving the survival rate of rats with this severe illness. Thus, HGF gene therapy may be potentially useful for the treatment of patients with liver cirrhosis, which is otherwise fatal and untreatable by conventional therapy.

Accelerated rejection of Fas ligand-expressing heart grafts

The Fas/Fas ligand (FasL) system plays an important role in the induction of lymphoid apoptosis and has been implicated in the suppression of immune responses. Recently, there has been renewed interest in immune privilege, as it was shown that two privileged sites (the eye and testes) constitutively express FasL, which kills lymphoid cells that invade these areas. We have established murine FasL-transgenic mice (B6) under the control of the cardiac alpha-myosin heavy chain promotor, and transplanted FasL-expressing F1(B6 x C3H/HeJ) heart grafts into syngeneic (F1) and allogeneic (C3H/HeJ) recipients. FasL-expressing F1 heart allografts placed in C3H/HeJ recipients as well as FasL-expressing F1 isografts placed in nontransgenic and FasL-transgenic F1 were more rapidly rejected, and their survival was much shorter than that of nontransgenic control F1 allografts placed in C3H/HeJ. Native control and FasL-expressing hearts looked normal in mice up to 8 wk of age on hematoxylin-eosin staining. Control heart allografts undergoing ordinally acute rejection showed moderate focal lymphocyte infiltrates, while FasL-expressing F1 allografts and isografts showed massive hemorrhage, edema, and massive neutrophil infiltration as early as 1 day after transplantation. In conclusion, FasL expression and surgical procedure (ischemia/reperfusion) were synergistic in the induction of accelerated heart graft rejection, while allogenicity was not necessary. It may be necessary to find ways of controlling neutrophilic reaction/apoptosis in infiltrating lymphocytes to use FasL in clinical organ transplantation.

Diagnosis of the nutcracker syndrome with color Doppler sonography: correlation with flow patterns on retrograde left renal venography

OBJECTIVE

Our objective was to confirm flow patterns of the left renal vein and assess the usefulness of color Doppler sonography in the diagnosis of the renal vein entrapment, or nutcracker, syndrome.

SUBJECTS AND METHODS

Forty-four patients with hematuria of unknown origin underwent color Doppler sonography, renal arteriography, retrograde left renal venography, and renocaval pressure measurement. The flow patterns were classified according to the presence or absence of distended left renal veins on sonograms and collateral veins on retrograde venograms. The sensitivity and specificity of color Doppler sonography for revealing the nutcracker syndrome were assessed by analyzing pressure gradients in combination with the venograms, which were used as the gold standard.

RESULTS

Twenty-one nondistended left renal veins were seen, including 19 (43%) without collateral veins or hypertension and two (5%) with collateral veins but without hypertension (long-term nutcracker syndrome). The 23 distended left renal veins included seven without collateral veins or hypertension and one with hypertension but without collateral veins (early nutcracker syndrome). The remaining 15 distended left renal veins with collateral veins included 11 (25%) with borderline hypertension (partially compensatory status of the syndrome) and four (9%) with hypertension (noncompensatory status of the syndrome). The sensitivity and specificity of color Doppler sonography for revealing the nutcracker syndrome were 78% and 100%, respectively, when color flow in collateral veins was included in the diagnostic criteria.

CONCLUSION

The nutcracker syndrome can exist in either nondistended or distended left renal veins. However, normal flow also can exist in distended left renal veins. The ability of color Doppler sonography to reveal color flow in collateral veins is useful for the noninvasive diagnosis of the nutcracker syndrome.

[Tubeless cutaneous ureterostomy through a single stoma with new extraperitoneal ureteral route up to stoma]

Tubeless cutaneous ureterostomy through a single stoma has been said to be difficult to establish in patients with normal ureters or normal ureters combined with thick fatty abdominal wall, because of the poor blood supply at the end of the ureters. The technical improvements observed were as follows: 1) The peritoneal fold and the upward traction of the gonadal vessels decrease the ureteral tension and keep the blood supply to the ureters in the extraperitoneal approach. 2) The gonadal vessels and its surrounding tissue, covering the subcutaneous fatty tissue, help the ureteral adhesion at the anastomotic site. 3) Full diminution of the skin defect caused by flap formation, decreases the horizontal tension of the side-to-side anastomized ureters. Sixteen patients with normal ureters underwent this procedure. In a short-term (4-37 months) observation, 4 of the patients, including one with thick abdominal fat, showed unilateral hydronephrosis and 2 patients unilateral non-function kidney. The remaining 10 patients had no complications. Moreover, all the patients have kept their ureterostomies tubeless and their serum blood urea nitrogen and creatinine levels were within normal limits except for one patient. It is reasonably concluded that the new method will result in success clinically even in patients with normal ureters and thick abdominal fatty tissue.

Accelerated Rejection of FAS Ligand-Expressing Heart Grafts

The Fas/Fas ligand (FasL) system plays an important role in the induction of lymphoid apoptosis and has been implicated in the suppression of immune responses. Recently, there has been renewed interest in immune privilege, as it was shown that two privileged sites (the eye and testes) constitutively express FasL, which kills lymphoid cells that invade these areas. We have established murine FasL-transgenic mice (B6) under the control of the cardiac α-myosin heavy chain promotor, and transplanted FasL-expressing F1(B6 × C3H/HeJ) heart grafts into syngeneic (F1) and allogeneic (C3H/HeJ) recipients. FasL-expressing F1 heart allografts placed in C3H/HeJ recipients as well as FasL-expressing F1 isografts placed in nontransgenic and FasL-transgenic F1 were more rapidly rejected, and their survival was much shorter than that of nontransgenic control F1 allografts placed in C3H/HeJ. Native control and FasL-expressing hearts looked normal in mice up to 8 wk of age on hematoxylin-eosin staining. Control heart allografts undergoing ordinally acute rejection showed moderate focal lymphocyte infiltrates, while FasL-expressing F1 allografts and isografts showed massive hemorrhage, edema, and massive neutrophil infiltration as early as 1 day after transplantation. In conclusion, FasL expression and surgical procedure (ischemia/reperfusion) were synergistic in the induction of accelerated heart graft rejection, while allogenicity was not necessary. It may be necessary to find ways of controlling neutrophilic reaction/apoptosis in infiltrating lymphocytes to use FasL in clinical organ transplantation.

Telomerase activity in hepatocellular carcinoma and adjacent liver tissues

BACKGROUND AND OBJECTIVES

Activation of telomerase and stabilization of telomeres are considered necessary for immortalization of tumor cells. Telomerase activity was analyzed in 69 hepatocellular carcinomas and adjacent chronic liver disease tissues. The telomerase activity level was examined in relation to clinicopathologic features.

METHODS

Telomerase activity was determined by a telomeric repeat amplification protocol. Immature and mature leukocytes were removed from homogenized tissue of adjacent livers using anti-CD45 and anti-CD15 monoclonal antibody-coated magnetic beads.

RESULTS

Telomerase activity was detected in hepatocellular carcinomas and leukocytes, but not in liver cells from adjacent chronic liver disease tissues after the separation of leukocytes. All hepatocellular carcinomas displayed telomerase activity, and the activity level correlated with the degree of differentiation (P=0.021) and patient survival (P=0.039).

CONCLUSIONS

These results indicate that activation of telomerase may be required as a critical step in hepatocarcinogenesis and tumor development, and detection of telomerase activity with removal of contaminating leukocytes may be useful in the characterization or prognostication of hepatocellular carcinoma.

HVJ-liposome mediated gene transfer into hepatocytes in vivo

BACKGROUND/AIMS

The efficient transduction of appropriate target cells will be critical for gene therapy. We evaluated the suitability of hemagglutinating virus of Japan (HVJ)-liposome-mediated gene transfer for gene therapy of liver diseases.

METHODS

The Escherichia coli beta-galactosidase (beta-gal) gene was introduced into rat liver by HVJ-liposome to examine gene transfer efficacy and persistence of expression with or without partial hepatectomy prior to transfection.

RESULTS

About 30% of hepatocytes were transduced after portal vein injection. Gene expression was transient, with only 2% of hepatocytes expressing beta-gal after 4 weeks. However, partial hepatectomy performed 24 h prior to injection resulted in persistently high levels of beta-gal for 4 weeks after injection. A 247-bp beta-gal polymerase chain reaction fragment transcript was detected in livers of transfected rats, but not in livers of control rats. The rat livers following gene transfer were histologically normal, and serum glutamic-pyruvic transaminase was not found to be elevated in rats.

CONCLUSIONS

Our results demonstrate that HVJ-liposome-mediated gene transfer produced high gene transduction and persistent gene expression in the liver.

Telomerase activity in hepatocellular carcinoma and adjacent liver tissues

BACKGROUND AND OBJECTIVES

Activation of telomerase and stabilization of telomeres are considered necessary for immortalization of tumor cells. Telomerase activity was analyzed in 69 hepatocellular carcinomas and adjacent chronic liver disease tissues. The telomerase activity level was examined in relation to clinicopathologic features.

METHODS

Telomerase activity was determined by a telomeric repeat amplification protocol. Immature and mature leukocytes were removed from homogenized tissue of adjacent livers using anti-CD45 and anti-CD15 monoclonal antibody-coated magnetic beads.

RESULTS

Telomerase activity was detected in hepatocellular carcinomas and leukocytes, but not in liver cells from adjacent chronic liver disease tissues after the separation of leukocytes. All hepatocellular carcinomas displayed telomerase activity, and the activity level correlated with the degree of differentiation (P=0.021) and patient survival (P=0.039).

CONCLUSIONS

These results indicate that activation of telomerase may be required as a critical step in hepatocarcinogenesis and tumor development, and detection of telomerase activity with removal of contaminating leukocytes may be useful in the characterization or prognostication of hepatocellular carcinoma.

The alpha1L-adrenoceptor subtype in the lower urinary tract: a comparison of human urethra and prostate

OBJECTIVE

To identify the alpha1-adrenoceptor subtypes present in the human urethra, by comparing the affinity of prazosin for alpha1-adrenoceptors in the rabbit, dog and human prostatic urethra, and in the dog and human prostate.

MATERIALS AND METHODS

The study comprised samples of human prostate and prostatic urethra, obtained by open prostatectomy of patients with benign prostatic hyperplasia, and of the proximal urethra and prostate from male Beagle dogs and rabbits. Specimens were homogenized, filtered and pelleted by centrifugation. Nonspecific binding was determined in the presence of 1 mmol/L prazosin when assessing [3H]YM-617 (tamsulosin) binding, and 10 mmol/L phentolamine when assessing [3H]prazosin binding. Specific binding was defined as the difference between total binding and nonspecific binding.

RESULTS

The dissociation constant for [3H]prazosin in the human prostate (0.088 nmol/L) was less than that in the rabbit urethra (0.299 nmol/L), dog urethra (0.604 nmol/L), dog prostate (0.482 nmol/L) and human urethra (0.254 nmol/L). The affinity of prazosin was also investigated by determining the potency of the inhibition of [3H]YM-617 binding. The affinity of prazosin for alpha1-adrenoceptors in the human urethra (Ki, 2.5 nmol/L) was lower than its affinity for alpha1-adrenoceptors in the human prostate (Ki, 0.25 nmol/L) and all of the cloned subtypes (Ki, 0.26-0.44 nmol/L).

CONCLUSION

The alpha1L-adrenoceptor subtype is more prominent in the human, rabbit and dog urethra and dog prostate than in the human prostate.

Retrovirus-mediated gene therapy for hepatocellular carcinoma: selective and enhanced suicide gene expression regulated by human alpha-fetoprotein enhancer directly linked to its promoter

We have previously reported that a retrovirus vector (LNAF0.3TK) carrying a herpes simplex virus thymidine kinase gene regulated only by the 0.3-kb human alpha-fetoprotein (AFP) promoter provides ganciclovir (GCV)-mediated cytotoxicity in high AFP-producing human hepatoma cells but not in low AFP-producing cells. In the present study, a retrovirus vector (LNAF0.3(E+)TK), in which herpes simplex virus thymidine kinase gene expression is under the control of a human AFP enhancer directly linked to its promoter, was constructed and compared with LNAF0.3(E+)TK. In the intermediate and low AFP-producing human hepatoma cells PLC/PRF/5 and huH1/cl.2, respectively, as well as in the high AFP-producing human hepatoma cells (HepG2), LNAF0.3(E+)TK sensitized these cells to GCV in vitro but did not affect cell growth in nonhepatoma cells (HeLa). In an animal model using athymic mice harboring PLC/PRF/5 cells, GCV treatment resulted in more pronounced growth inhibition in the LNAF0.3(E+)TK virus-infected cells than in the LNAF0.3(E+)TK virus-infected cells. These results indicate that the human AFP enhancer that is directly linked to its promoter involves selective and enhanced tumoricidal activity in gene therapy for hepatocellular carcinoma.

Astrocytic gap junction blockage and neuronal Ca2+ oscillation in neuron-astrocyte cocultures in vitro

We have investigated the effects of gap junction inhibitors, octanol, halothane, sodium propionate and lindane, on neuronal periodic Ca2+ transients in neuron-astrocyte coculture systems. Octanol reduced the amplitude and frequency of Ca2+ oscillations in dose-dependent manner. One mM octanol caused a complete disappearance of Ca2+ oscillations. Similar suppressions were obtained by halothane (1 mM) and sodium propionate (25 mM). In contrast, lindane (300 nM) uniquely raised the basal level of [Ca2+], in oscillating neurons as well as the height of apparent amplitude without changes in the frequency. The current results imply that octanol, halothane and sodium propionate might lower the frequency of spontaneous Ca2+ oscillations by blocking the gap junctional communication of neighboring astrocytes and that lindane, though also blocking the gap junctions, might not affect the frequency but reversely increase both the basal [Ca2+]i and the amplitude, probably due to an increase of neuronal [Ins (1.4.5)P3]i. These findings strongly suggest that astrocytes contribute to the generation of periodic neuronal Ca2+ oscillations through astrocytic gap junctional communications and/or other signaling components between astrocytes and neurons.

Expressions of basic fibroblast growth factor and fibroblast growth factor receptor mRNA in soft tissue tumors by in situ hybridization

Basic fibroblast growth factor (bFGF) is a mitogenic and angiogenic polypeptide produced by diverse cell types, including the cells derived from normal tissue and neoplastic lesions. To evaluate the possible differential expression of bFGF in soft tissue tumors, we examined 17 frozen primary soft tissue tumors including extra-abdominal desmoids, leiomyosarcomas, synovial sarcomas, myxoid liposarcomas, and alveolar soft part sarcomas by nucleic acid in situ hybridization. Three of the four leiomyosarcomas and two of the three synovial sarcomas studied expressed bFGF mRNA, whereas all of the myxoid liposarcomas and alveolar soft part sarcomas were negative. Two of the leiomyosarcomas were also positive for FGF receptor mRNA. These results indicated the possibility of an autocrine or paracrine mechanism in the function of bFGF and also lent support to the opinion that in situ hybridization is useful for examining cell character.

Otx cognates in a lamprey, Lampetra japonica

Gnathostomes have two lineages of Otx genes, Otx1 and Otx2, as cognates of a Drosophila head gap gene, orthodenticle. Previous studies with mutant mice have demonstrated that they play essential roles in the development of rostral head. To shed lights on the evolution of the rostral head in vertebrates we isolated their cognates in the Japanese marine lamprey, Lampetra japonica. The lamprey genome appeared to have two Otx cognantes, LjOtxA and LjOtxB. Phylogenetic analyses suggest that LjOtxA clusters with gnathostome Otx2 genes, but LjOtxB does not belong to either the Otx1 or Otx2 lineage. LjOtxA was expressed in the forebrain and midbrain with the caudal limit possibly at the midbrain/hindbrain junction as gnathostome Otx cognates are, but LjOtxB was not expressed in the brain. No Otx1 or Otx2 cognates are known in gnathostomes that are not expressed in the brain. Both LjOtxA and LjOtxB were expressed in the olfactory placode, epiphysis, optic stalks, and lower and upper lips. LjOtxB was also expressed in the eyes, where no LjOtxA transcripts were detected. Thus, Otx1 and Otx2 functions for the development of forebrain and midbrain in gnathostomes appear to be shouldered by LjOtxA alone in the lamprey. LjOtxB may have diverged from the stem of the Otx1 and Otx2 lineages and evolved independently.

A new sigma factor, SigD, essential for stationary phase is also required for multicellular differentiation in Myxococcus xanthus

BACKGROUND

Myxococcus xanthus is a gram-negative bacterium that undergoes spectacular development to form multicellular fruiting bodies under nutrient deprivation. Inside a fruiting body, vegetative cells differentiate into spores. A number of sigma factors have been shown to play roles in the regulation of gene expression in the M. xanthus life cycle. Additional sigma factors were searched to further explore the M. xanthus life cycle.

RESULTS

A new sigma factor was identified, SigD, which consists of 297 amino acid residues. Two transcription initiation sites for the sigD gene were detected by primer extension analysis using total RNA from the vegetative and developmental cells, one of which was specific for development. The characterization of sigD-lacZ fusion strains demonstrated that sigD expression increased during entry into stationary phase of vegetative growth and during early development. A deletion mutant of sigD exhibited growth defects during the late-log phase and stationary phase, with dramatically reduced cell viability. The patterns of protein synthesis at late log phase of vegetative growth and at early development on CF agar plates were significantly different between the deletion mutant and the wild-type strain. The deletion mutant was more sensitive to various stresses when compared with the wild-type strain and did not accumulate trehalose in response to osmotic stress. The deletion mutant also showed a significant delay in fruiting body formation and sporulation and yielded fewer spores than the wild-type strain.

CONCLUSIONS

SigD shows characteristic features of the stationary phase sigma factors and also plays important roles in multicellular differentiation of M. xanthus.

Trichromatic Concept at SPring-8 RIKEN Beamline I

SPring-8 RIKEN beamline I has been designed and developed for structural biology research by the Institute of Physical and Chemical Research (RIKEN). The beamline consists of two experimental stations for protein crystallography and small-angle X-ray scattering. Both types of experiments can be carried out simultaneously, with dichromatic synchrotron radiation emitted from two coaxial undulators with vertical polarization. The branched beams are generated by a transparent diamond crystal. With synchrotron radiation, the multiple-wavelength anomalous-dispersion (MAD) method, which gives phases from a single anomalous scatterer, has been developed. Anomalous scattering contributes a small proportion of the diffraction intensity so that the accuracy of intensity data is important. The protein crystallography branch of RIKEN beamline I has been designed based on a 'trichromatic concept' to optimize MAD data collection. This concept requires the quasi-simultaneous collection, by use of a 'trichromator', of three intensity data sets at three different wavelengths from a single protein crystal without changing any settings. The main feature of the concept is the minimization of systematic errors in the measurement of anomalous diffraction for the MAD method. Initial commissioning of the beamline has provided three different monochromated undulator beams, which were successfully observed on the phosphor screen located at the near end of the trichromator.

Early development of the peripheral nervous system in a lancelet species

The developmental pattern of the lancelet (amphioxus) peripheral nervous system from embryos to larvae has been studied by using wholemount immunostaining and transmission electron microscopy. The peripheral nerves first appeared on the anterior dorsal surface of the medulla at the middle neurula stage, when the anterior nerve cord was just closing. A single axon with a large growth cone was the progenitor of each nerve. The nerve roots adopted an asymmetric arrangement soon after. The first nerve, likely a pair of pure sensory nerves, sprouted from the anterior tip of the nerve cord. This nerve may be comparable topographically to the preoptic nerve (the posterior branch of the terminal nerve) in lungfishes. However, the neuron that first extends its axon was located in the medulla, as in the other posterior nerves. One of the extramedullary primary sensory neurons, the corpuscles of de Quatrefages, appeared in larvae with the mouth and two anterior gill pores. Their axons were seemingly fasciculated with the efferent axon of the first nerve. The second nerve, the most complex one to appear during embryonic and early larval development, innervated the preoral pit and the buccal region. The third and fourth nerves on the left side also innervated the buccal region. The larval innervation patterns in the anterior region differed from the adult organization, suggesting a segmental rearrangement of the nerve supply during development. There was no evidence to dichotomize the peripheral nerves into cranial and spinal nerves, as exist in vertebrates. These characteristics of the peripheral nervous system in the lancelet indicate that this animal has a rather derived or primitive developmental system of peripheral nerves, making the analysis of homology with vertebrates difficult.

Secretory carcinoma of the breast in an elderly woman: report of a case

We herein report a case of secretory carcinoma of the breast in a 73-year-old woman. Secretory carcinoma is an extremely rare tumor and demonstrates distinctive pathologic characteristics. This tumor frequently occurs in either children or adolescents, and thus has been called juvenile carcinoma. We encountered this rare tumor in an elderly woman. Aspiration biopsy cytology was performed twice, but the cytological diagnosis was not carcinoma. Such pathologic characteristics as mild atypia, the absence of hyperchromasia, and a minimal degree of pleomorphism in the tumor cells can thus lead to a cytological misdiagnosis. An excisional biopsy was performed and secretory carcinoma was finally diagnosed. Consequently, a modified radical mastectomy (Kodama's method) was performed 7 days later. We describe this very rare tumor's clinicopathologic characteristics.

Activation of mitogen-activated protein kinases/extracellular signal-regulated kinases in human hepatocellular carcinoma

Mitogen-activated protein kinase/extracellular signal-regulated protein kinase (MAPK/ERK) is a key molecule in intracellular signal transducing pathways that transport extracellular stimuli from cell surface to nuclei. MAPK/ERK has been revealed to be involved in the physiological proliferation of mammalian cells and also to potentiate them to transform. However, its role in the outgrowth of human hepatocellular carcinoma (HCC) has yet to be clarified. Therefore, in this study, we investigated the activation of MAPK/ERK and its associated gene expression in HCC. MAPK/ERK was activated in 15 of 26 cases of HCC we examined (58%), and its activity level was significantly higher in HCC than in the adjacent non-cancerous lesions. Besides, MAPK/ERK activation in HCC was positively correlated with protein expression of transcription factor c-Fos. Furthermore, in 25 of 26 cases of HCC which genomic DNA was available, 22 cases without genomic DNA amplification exhibited positive correlation, not only between protein expression of c-Fos and cyclin D1, but also between MAPK/ERK activation and cyclin D1 expression. Concerning the relationship between MAPK/ERK activation and the clinicohistopathological features of HCC, the tumor (HCC) versus non-tumor (non-cancerous counterpart) ratio (T/N) of MAPK/ERK activity was positively correlated with tumor size, but neither with the stage of HCC nor the degree of differentiation of HCC. In conclusion, these findings suggest that MAPK/ERK activation in human HCC may play an important role in multistep hepatocarcinogenesis, especially in the progression of HCC; at least in part, through cyclin D1 up-regulation primarily induced by MAPK/ERK via c-Fos.

Guanidine hydrochloride-induced changes of the E2 inner core of the Bacillus stearothermophilus pyruvate dehydrogenase complex

The limited proteolysis of the Bacillus stearothermophilus pyruvate dehydrogenase complex by V8 protease yields its core structure solely composed of lipoate acetyltransferase (E2) fragments. The changes in the core with guanidine hydrochloride (GdnHCl) were biphasic: below 0.8 M (first) and above 1.0 M (second) GdnHCl. The changes in the first phase were slight but significant: decreases in ellipticity and light scattering, and an increase in E2 activity. Insignificant changes in the molecular shape and size of the core were detected on fluorescence spectroscopy, ultracentrifugation, gel filtration, and electron microscopy. On the other hand, the changes in the second phase were drastic; the core was disassembled and denatured.

Retrovirus-mediated gene therapy for human hepatocellular carcinoma transplanted in athymic mice

Gene therapy using a retrovirus vector carrying herpes simplex virus thymidine kinase gene under the control of the 0.3-kb human alpha-fetoprotein (AFP) gene promoter (LNAF0.3TK virus) in combination with ganciclovir (GCV) treatment was performed in athymic mice harboring AFP-producing HuH-7 human hepatoma cells. GCV treatment resulted in pronounced growth inhibition of the virus-infected HuH-7 xenograft in mice, but did not affect growth of the parental xenograft. These results indicate that the AFP gene promoter sequence allows enough therapeutic gene expression to induce the GCV-mediated cytotoxicity in vivo in AFP-producing human hepatoma cells.

Persistent gene expression in rat liver in vivo by repetitive transfections using HVJ-liposome

Most viral vectors are highly immunogenic and are of limited use for somatic gene therapy that requires repetitive administrations. We have developed a highly efficient gene transduction procedure useful for repetitive transfections using liposome containing hemagglutinating virus of Japan (HVJ-liposome). The Escherichia coli beta-galactosidase (beta-gal) gene was embodied in HVJ-liposome, and introduced directly into the caudal lobe of rat liver that was transiently isolated from a systemic circulation. A 116 kDa beta-gal protein was detected in transfected rat liver tissues by Western blot analysis and it was expressed in more than two-thirds of the liver by histological staining. It was found that the transfection efficiency was not affected by repetitive transfections. In support of these findings, antibody response to HVJ-liposome detected in the rat sera was weak and transient. Furthermore, cytotoxic T lymphocytes were not elicited against autologous rat hepatocytes that were transfected in vivo using HVJ-liposome. Thus, our results demonstrate that the isolation of a target liver from systemic circulation and the direct administration of foreign genes using HVJ-liposomes are useful for high gene transduction and persistent gene expression in the liver.

Expression of a twist-related gene, Bbtwist, during the development of a lancelet species and its relation to cephalochordate anterior structures

Mesoderm formation plays a crucial role in the establishment of the chordate body plan. In this regard, lancelet embryos develop structures such as the anteriorly extended notochord and the lateral divertecula in their anterior body. To elucidate the developmental basis of these structures, we examined the expression pattern of a lancelet twist-related gene, Bbtwist, from the late gastrula to larval stages. In late-gastrula embryos, the transcripts of Bbtwist were detected in the presumptive first pair of somites and the middorsal wall of the primitive gut. The expression of Bbtwist was then upregulated in the lateral wall of somites and the notochord. At the late-neurula stage, it was also expressed in the anterior wall of the primitive gut, as well as in the evaginating lateral diverticula. No signal was detected in the left lateral diverticulum when it was separated from the gut, while in the right one, the gene was expressed later during the formation of the head coelom in knife-shaped larvae, and in the anterior part of the notochord in the same larvae. In 36-h larvae, only faint expression was detected in the differentiating notochordal and paraxial mesoderm in the caudal region. These expression patterns suggest that Bbtwist is involved in early differentiation of mesodermal subsets as seen in Drosophila and vertebrates. The expression in the anterior notochord may be related to its anterior expansion. The expression in the anterior wall of the primitive gut and its derivative, the lateral diverticula, suggests that lancelets share the capability to produce a mesodermal population from the tip of the primitive gut with nonchordate deuterostome embryos.

Stereotyped axonal bundle formation and neuromeric patterns in embryos of a cyclostome, Lampetra japonica

Early embryonic development of the nervous system of a lamprey, Lampetra japonica, was studied by using immunohistochemical techniques and by scanning electron microscopy. The earliest appearance of axons was detected at Tahara's stage 21-, when dorsolateral and ventral longitudinal fasciculi were present in the hindbrain and spinal cord regions. The branchiomeric nerve roots began to appear at stage 22; the fibers were joined to the dorsolateral fasciculus proximally and also extended distally into each pharyngeal arch. The anterior neural tube was divided into several neuromeres: the mid-hindbrain sulcus became apparent first, then the portion rostral to this sulcus was subdivided into two portions by the syn-parencephalic boundary. In the hindbrain around stage 23, rhombomeres developed transiently, of which, rhombomere 4 was the most distinctive. Putative crest cells forming the octavofacial nerve root anlage were selectively adhering to rhombomere 4, whereas no crest cells were found on rhombomere 3. The assignment of the crest-derived nerve anlage to rhombomeres is conserved between gnathostomes and L. japonica. The neuromerical scheme of the neural tube of L. japonica is also mostly in accordance with that in gnathostomes, sharing the basic developmental patterning of axon bundles at early developmental stages. The most distinct difference between these two groups is the topographical relationships between the hindbrain neuraxis and pharyngeal arches, as well as the otic placode.

Rostral truncation of a cyclostome, Lampetra japonica, induced by all-trans retinoic acid defines the head/trunk interface of the vertebrate body

The effect of all-trans retinoic acid on embryogenesis was studied in a cyclostome, Lampetra japonica. Treatment with 0.05-0.5 microM retinoic acid on early gastrula and early neurula resulted in loss of the pharynx and in the rostral truncation of the neural tube. The mouth, pharynx, esophagus, heart, endostyle, and rostral brain were missing with graded severity. In the severest case, the embryo consisted only of trunk segments, especially myotomes that extended to the rostral end of the axis. The effect appeared to be dose- and stage-dependent: Rostral pharyngeal arches were more vulnerable to a lower amount of retinoic acid, and earlier treatment resulted in severer defects. The initial protrusion of the anterior axis started equally in control and retinoic acid-treated embryos, implying that the head morphogenesis is omitted in treated embryos. By identifying the number of myotomes based on the differentiation of hypobranchial muscles, there seemed to be no myotomes lost by retinoic acid-induced truncation. The rostral truncation, therefore, was not simply a limitation of the anterior axis but was restricted to the ventral portion; only the branchial arches disappeared with normally developing myotomes dorsally. The absent region can be defined as the vertebrate head in a morphological sense, including the branchiomeric and preotic paraxial regions as well as the heart. The results suggest the presence of distinct programs between somitomeric and branchiomeric portions of the body, providing a developmental basis for the dual-metamerical body plan of vertebrates.

Lymphoepithelial cyst of the pancreas

A case of lymphoepithelial cyst (LEC) of the pancreas is presented. A 48-year-old man complaining of general fatigue was found to have a heterogeneous water-dense mass protruding from the surface of the pancreas on plain computed tomography (CT). Dynamic CT disclosed septa within the mass. Magnetic resonance imaging, (MRI) showed a hypointense mass on T1-weighted imaging, and a hyperintense mass on T2-weighted imaging. MRI with gadolinium enhancement revealed septa within the mass. Endoscopic ultrasonography showed septa and fine echogenic structures within the cystic echoic lesion. Endoscopic retrograde pancreatography showed a normal duct system. Distal pancreatectomy with splenectomy was performed, with a suspected diagnosis of cystic neoplasms of the pancreas. Histopathologic examination disclosed LEC of the pancreas. Our case suggests that LEC should be considered in the differential diagnosis of cystic neoplasms of the pancreas.

Establishment and characterization of a new synovial sarcoma cell line, SN-SY-1: special reference to bcl-2 protein and SYT-SSX1 hybrid transcripts

We established and characterized a new human synovial sarcoma cell line, SN-SY-1, derived from a monophasic fibrous synovial sarcoma excised from the abdominal wall of a 21-year-old man. We maintained the cell line for over 35 passages in vitro. The SN-SY-1 cells in vitro exhibit spindle and polygonal shapes and join to form an epithelial plaque. SN-SY-1 maintained a consistent karyotype: 46,t(X;18)(p11.2;q11.2), Y, t(6;8) (q13-15;q11-13), the same as that of the primary tumor specimen. RT-PCR assay for chimeric SYT-SSX transcripts followed by digestion with restriction enzymes revealed SYT-SSX1 fusion protein. An immunohistochemical study revealed expression of bcl-2 protein in the SN-SY-1 cell line, in vitro and in vivo. However, DNA analysis showed no rearrangement of the bcl-2 gene, and expression of bcl-2 mRNA was low. Why bcl-2 protein was expressed in this synovial sarcoma was not clarified.

Peripheral development of cranial nerves in a cyclostome, Lampetra japonica: morphological distribution of nerve branches and the vertebrate body plan

The development of peripheral nerves was studied in a Japanese marine lamprey, Lampetra japonica, in whole-mount and sectioned embryos from hatching until the earliest ammocoete. Nerve fibers were immunohistochemically stained with a monoclonal antibody against acetylated tubulin. Branchiomeric nerves first developed in a simple metamerical pattern, each associated with a single pharyngeal arch. Of those, the ophthalmicus profundus, maxillomandibular, and facial nerves later developed a highly modified branching pattern, whereas postotic nerves were less specialized and showed the stereotypical branching pattern of post-trematic nerves. The early distribution of melanocytes in myotome-free space largely overlapped with the morphology of the cranial nerve and ganglion anlage, and resembled the cephalic crest cell distribution pattern in the early chick embryo. It was suggested that the cephalic crest cell distribution, which is also inhibited by myotomes in the lamprey, would be the common basis for branchiomeric nerve patterning. In later development of the lamprey embryo, myotomes 1 through 3, which had originated in the postotic region, grew rostrally into the preotic region, laterally covering all of the branchiomeric nerves. This results in a deep position of the cranial nerves, which is not observed in gnathostomes.