In vitro characterization of missense mutations associated with quantitative protein S deficiency

OBJECTIVE

To elucidate the molecular consequences of hereditary protein S (PS) deficiency, we investigated the in vitro synthesis of the PS missense mutants in COS-1 cells and their activated protein C (APC) cofactor activities.

PATIENTS

Four patients with quantitative PS deficiency suffering from venous thrombosis were examined.

RESULTS

We identified three distinct novel missense mutations, R275C, P375Q and D455Y, and two previously reported missense mutations, C80Y and R314H. The P375Q and D455Y mutations were found in one patient and observed to be in linkage on the same allele. The R314H mutant showed the lowest level of expression (32.7%), and the C80Y, P375Q + D455Y, and R275C mutants exhibited a moderate impairment of expression, that is, 43.8%, 49.5%, and 72.3% of the wild type, respectively. Furthermore, pulse-chase experiments demonstrated that all mutants showed impaired secretion and longer half-lives in the cells than the wild type PS. In the APC cofactor assays, the C80Y mutant showed no cofactor activity, and the R275C mutant showed reduced activity, 62.3% of the wild type PS, whereas the R314H and P375Q + D455Y mutants exhibited normal cofactor activity.

CONCLUSION

These data indicate that the C80Y and R275C mutations affect the secretion and function of the PS molecule, and that the R314H and P375Q + D455Y mutations are responsible for only secretion defects, causing the phenotype of quantitative PS deficiency observed in the patients.

Effectiveness and new safety profile of rasburicase (urate oxidase) in Japanese patients with malignant lymphoma and acute leukemia in phase II study (ARD5290)

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Background: Rasburicase (RAS) for the prevention of tumor lysis syndrome (TLS) populations at high risk, and for the treatment of hyperuricemia (HU) has obtained approvals in most countries in the world except in Japan. Thus, we conducted licensing phase II study of RAS with primary endpoint of overall efficacy response (ER) rate. We report efficacy and the new safety profile of only RAS administration prior to chemotherapy. Methods: Fifty patients (pts) with ML and/or AL, were administered RAS for 5 days using two dose-levels (0.15 mg/kg/day or 0.20 mg/kg/day). Chemotherapies were started from 4 to 24 hours after RAS treatment. ER was defined as keeping plasma uric acid level 7.5mg/dL by 48 hr after the start of first RAS infusion and lasting until 24 hr after the start of final (Day5) RAS infusion. Results: The overall ER rate was 98%. 49 pts (98%) completed 5 days of treatment. Both doses provided equally effective reduction of uric acid under the study conditions. Seven drug-related adverse events of grade 1 or 2 by NCI-CTC occurred in 6 pts during using only RAS (before first chemotherapy). ‘Hypersensitivity’ occurred in 3 pts, and ‘rash’, ‘anorexia’, ‘application site pain’, and ‘pyrexia’ occurred in 1 patient each. No grade 3 or 4 adverse events were reported. Only five pts (10%) had anti-RAS antibodies by Day29. Conclusions: RAS has proved to be highly effective with a good safety profile including the new safety one as single agent without chemotherapy. Although both two levels were effective, level of 0.20 mg/kg seems to be an optimal dose because RAS was effective against serious cases of HU in this level. The presence of anti-RAS antibodies was very low suggesting that the possibility for retreatment maybe possible.

No significant financial relationships to disclose.

Risk and prognostic factors for Japanese patients with chronic graft-versus-host disease after bone marrow transplantation

The incidence and prognostic factors for chronic graft-versus-host disease (cGVHD) were evaluated for 255 Japanese patients who survived more than 100 days after bone marrow transplantation, and of whom 119 (47%) developed cGVHD. Prior acute GVHD (grade 2-4) and use of an unrelated donor were significantly associated with the onset of cGVHD. Presence of cGVHD did not have an impact on mortality (hazard ratio (HR) = 0.89; 95% confidence interval (CI), 0.59-1.3). Three factors at diagnosis were associated with cGVHD-specific survival: presence of infection (HR = 4.1; 95% CI, 1.6-10.3), continuing use of corticosteroids at the onset of cGVHD (HR = 3.9; 95% CI, 1.7-9.1), and a Karnofsky performance score <80 (HR = 4.7; 95% CI, 2.0-11.3). The probability of cGVHD-specific survival at 4 years was 79% (95% CI, 70-86%). The severity and death rate of Japanese patients with cGVHD was lower than those for populations in Western countries, which might be the result of greater genetic homogeneity of Japanese ethnics. Our patients could not be accurately classified when the proposed prognostic models from Western countries were used, thus indicating the need for a different model to identify high-risk patients.

Roles of cyclooxygenase 2 and microsomal prostaglandin E synthase 1 in rat acid reflux oesophagitis

BACKGROUND

Although prostaglandin E2 (PGE2), cyclooxygenase 2 (COX-2), and microsomal prostaglandin E synthase 1 (mPGES-1) are known to play a role in various inflammatory events, their roles in the pathogenesis of gastro-oesophageal reflux disease are not known.

AIMS

We examined the dynamics of COX-1, COX-2, mPGES-1, mPGES-2, cytosolic PGES (cPGES), and PGE2 synthetic activity in rat acid reflux oesophagitis and the effects of COX-2 inhibitors on the severity of oesophagitis.

METHODS

Acid reflux oesophagitis was induced by ligating the transitional region between the forestomach and the glandular portion and wrapping the duodenum near the pylorus. Rats were killed on day 3 (acute phase) or day 21 (chronic phase) after induction of oesophagitis.

RESULTS

Expression of COX-2 and mPGES-1 was markedly increased in oesophagitis while modest changes in COX-1, cPGES, and mPGES-2 expression were observed. COX-2 and mPGES-1 were colocalised in epithelial cells of the basal layer, as well as inflammatory and mesenchymal cells in the lamina propria and submucosa. COX-2 inhibitors significantly reduced the severity of chronic oesophagitis but did not affect acute oesophageal lesions. COX-2 inhibitors significantly inhibited the increase in PGE2 synthesis in oesophageal lesions on both days 3 and 21. Epithelial proliferation was significantly increased in the basal layer on day 21. Inflammatory cells and epithelial cells of the basal layer exhibited reactions for EP4 in oesophagitis.

CONCLUSION

PGE2 derived from COX-2 and mPGES-1 plays a significant role in the pathogenesis of chronic acid reflux oesophagitis, and possibly in basal hyperplasia and persistent inflammatory cell infiltration.

A case of coagulation factor V deficiency caused by compound heterozygous mutations in the factor V gene

We investigated the molecular basis of a severe factor V (FV) deficiency in a Japanese female, and identified two distinct mutations in the FV gene, a novel cytosine insertion (1943insC) and a previously reported point mutation (A5279G). We expected the patient to be a compound heterozygote for those mutations, as a 1943insC, but not an A5279G, was found in the mother and a sibling. The 1943insC will cause a frame-shift after 590Gln, resulting in amino acid substitutions with two abnormal residues followed by a stop codon in the FV A2 domain (FS592X). The A5279G will cause an amino acid alteration in the FV A3 domain (Y1702C), which has been observed in several ethnic groups. We found that both mutant mRNAs were detected by reverse transcriptase polymerase chain reaction (RT-PCR) in the patient's platelets, whereas no FV antigen and activity were detected in plasma. On the one hand, the RT-PCR signal from the FS592X-FV mutant mRNA was markedly reduced, suggesting that the RNA surveillance system would eliminate most of the abnormal FS592X-FV transcripts with a premature termination. On the other hand, expression analyses revealed that only small amounts of Y1702C-FV with a low specific activity were secreted, and that the FS592X-FV was not detected in cultured media. These data indicated that both mutant FV molecules would be impaired, at least in part, during the post-transcriptional process of protein synthesis and/or in secretion. Taken together, it seems to suggest that each gene mutation could be separately responsible for severe FV deficiency, while this phenotype is due to the in-trans combination of the two defects.

Expression of matrix metalloproteinases in benign and malignant follicular thyroid lesions

AIMS

To examine expression of matrix metalloproteinases (MMPs) and related proteins in follicular thyroid lesions (FTLs) and to determine their usefulness for differential diagnosis of FTLs, particularly between minimally invasive carcinoma and adenoma.

METHODS AND RESULTS

Six widely invasive follicular carcinomas (WIFCs), 15 minimally invasive follicular carcinomas (MIFCs), 19 follicular adenomas (FAs) and 10 adenomatous goitres (AGs) were analysed immunohistochemically for MMP-1, MMP-2, MMP-7, MMP-9, membrane-type 1-MMP (MT1-MMP) and tissue inhibitor of matrix metalloproteinase-2 (TIMP-2). MMP-1 was positive in all FTLs. MMP-2 and MMP-7 were positive in more than 80% of WIFC and MIFC cases, whereas they were negative in all FA and AG cases except one MMP-2+ FA (P < 0.001). MMP-9 stained positive significantly more in MIFC than FA or AG cases (P < 0.05, respectively). The positivity of MT1-MMP and TIMP-2 was different among some of the FTLs, but with no significant difference between MIFC and FA cases. In-situ hybridization of MMP-2 and MMP-7 mRNA in selected cases demonstrated the expression of these enzymes in the tumour cells as well as in some stromal cells.

CONCLUSIONS

Our results confirm MMP expression mainly in malignant FTLs and suggest that MMP-2 and MMP-7 may be useful markers to distinguish MIFC from FA.

v-Src requires Ras signaling for the suppression of gap junctional intercellular communication

Cell transformation by v-Src causes suppression of gap junctional intercellular communication (GJIC). Although tyrosine phosphorylation of connexin43 (Cx43), a gap junctional component, appears to be necessary for the suppression, involvement of other signaling remains unclear. We investigated the role of Ras signaling in the suppression of GJIC by v-Src. Conditional expression of either S17N Ras or mtGap1m dramatically recovered GJIC in v-Src-transformed cells. Although expression of S17N Ras or mtGap1m substantially decreased the levels of active Ras, tyrosine phosphorylation of cellular proteins including Cx43 remained unchanged. Similarly, treatment of v-Src-transfomed cells with a Ras farnesyltransferase inhibitor, manumycin A, restored GJIC, whereas tyrosine phosphorylation of Cx43 remained unchanged. Thus, these results strongly suggest that, in addition to Cx43 phosphorylation, constitutive activation of Ras signaling is required for the suppression of GJIC by v-Src.

Cytomegalovirus antigenemia and outcome of patients treated with pre-emptive ganciclovir: retrospective analysis of 241 consecutive patients undergoing allogeneic hematopoietic stem cell transplantation

CMV disease remains a major infectious complication after allogeneic hematopoietic stem cell transplantation (HSCT). To investigate the relationship between CMV antigenemia, treatment with ganciclovir (GCV), and outcome, we retrospectively analyzed 241 consecutive patients at risk for CMV infection who underwent allogeneic HSCT. Antigenemia-guided pre-emptive strategy with GCV was used for all patients. CMV antigenemia developed in 169 patients (70.1%), and CMV disease in 18 patients (7.5%). Multivariate analysis showed that acute GVHD (grades II-IV) was the only risk factor for developing antigenemia, and acute GVHD and advanced age for CMV disease. GCV use, as well as acute GVHD and advanced age, significantly increased the risk for bacterial and fungal infection after engraftment. Those who developed CMV antigenemia had a poorer outcome than those who did not (log-rank, P=0.0269), although the development of CMV disease worsened the outcome with only borderline significance (log-rank, P=0.0526). In conclusion, detection of antigenemia proved to be a poor prognostic factor for HSCT patients, which may be attributed to a combination of factors, including CMV disease itself, the effect of treatment, and a host status that allows for reactivation of CMV. Optimal pre-emptive strategy needs to be determined.

A nationwide survey of deep fungal infections and fungal prophylaxis after hematopoietic stem cell transplantation in Japan

We conducted a nationwide survey to define incidence of deep fungal infections and fungal prophylaxis practices after HSCT. In all, 63 institutions responded. Total number of in-patient transplantations was 935: 367 autologous, 414 allogeneic myeloablative, and 154 allogeneic reduced-intensity (RIST) (n=154). Number of patients who were cared for in a clean room at transplant was 261 (71%) in autologous, 409 (99%) in conventional and 93 (66%) in RIST, respectively. All patients received prophylactic antifungal agents; 89% fluconazole. Number of patients who received the dosage recommended in the CDC guidelines (400 mg/day) was 135 (42%) in conventional transplant and 34 (30%) in RIST (P=0.037). Number of patients who received fluconazole until engraftment and beyond day 75 in conventional transplant vs RIST was, respectively, 324 (100%) vs 109 (97%), and 39 (12%) vs 18 (16%), with no significant difference between the two groups. A total of 37 patients (4.0%) were diagnosed with deep fungal infections; autologous transplantation (0.03%), conventional transplantation (6.0%) and RIST (7.1%). Wide variations in antifungal prophylaxis practice according to the type of transplant and the institutions, and deep fungal infection remain significant problems in RIST.

Intestinal thrombotic microangiopathy after allogeneic bone marrow transplantation: a clinical imitator of acute enteric graft-versus-host disease

Thrombotic microangiopathy after bone marrow transplantation (post-BMT TMA) is a serious transplant-related complication. We identified 16 patients with TMA after allogeneic BMT who showed histopathological evidence of intestinal TMA in their gut specimens (six autopsies, 10 biopsies). In all, 14 patients had grade II-IV acute graft-versus-host disease (GVHD). The first seven patients were retrospectively diagnosed with TMA. Since six of them were diagnosed with progressive GVHD at that time because there was no awareness of the existence of intestinal TMA, they received more intensive treatment for GVHD, but all died between days +49 and +253. In contrast, the remaining nine patients were recently diagnosed with intestinal TMA on the basis of colonoscopic biopsies. For eight of these patients, the immunosuppressants were reduced, and the patients' intestinal symptoms improved gradually. Six of the nine patients were still alive 12 months after the diagnosis of TMA. Our findings suggest that the gut may be a site involved in post-BMT TMA, presenting as ischemic enterocolitis. Differentiating intestinal TMA from acute GVHD is important in patients suffering from severe and refractory diarrhea after BMT.

Influence of aging on tooth eruption: experimental canine mandibular allograft

PURPOSE

Aging is clinically related to tooth eruption; however, there are no known studies that have elucidated the relationship. We examined whether tooth eruption would occur normally in a mature subject.

MATERIALS AND METHODS

Using vascularized composite tissue mandibular transplantation, we extracted portions of immature mandibles including the tooth germs from young beagle dogs and placed them into unrelated immature and mature beagle dogs. We then examined eruption of the lower first molar in the grafted mandibular bone and compared the results clinically, radiographically, and histologically.

RESULTS

Normal tooth eruption was observed in the transplanted mandibles in the young dogs. In the mature dogs, eruption from the gingiva was delayed, whereas that from alveolar bone occurred normally in the transplanted mandibles. Further, the whole crown was covered with a cap of gingival tissue in the mature dogs, although this cap was not gingival overgrowth.

CONCLUSIONS

Tooth eruption is influenced by some unknown factors related to aging. Apparently, apoptosis did not occur in the connective tissues between the reduced enamel epithelia and oral epithelia that overlay the teeth in the mature subjects.

Indomethacin, but not Helicobacter pylori, inhibits adaptive relaxation in isolated guinea-pig stomach

Nonsteroidal anti-inflammatory drugs (NSAIDs) and Helicobacter pylori (H. pylori) are major factors in gastritis and peptic ulcer However, the role of NSAIDs and H. pylori infection in dyspepsia remains unclear. Gastric adaptive relaxation may be related to the pathogenesis of functional dyspepsia because the response is often disturbed in dyspeptic patients. In this study, we investigated the effects of indomethacin or H. pylori water extracts on gastric adaptive relaxation. This experiment was performed using the modified method of Desai et al. Isolated guinea-pig stomach in an organ bath was monitored for intragastric pressure and volume. Adaptive relaxation was induced by gastric luminal distention. The effects of indomethacin and H. pylori on gastric relaxation were tested in this system. Indomethacin (> 1 x 10(-5) M) significantly inhibited adaptive relaxation. Indomethacin (> 3 x 10(-6) M) induced gastric relaxation in a dose-dependent fashion. However, aspirin at a concentration sufficient for cyclooxygenase (COX)-1 inhibition did not induce gastric relaxation. Preincubation with N-nitro-L-arginine methyl ester, a nitric oxide (NO)-synthase inhibitor, inhibited indomethacin-induced gastric relaxation. Adaptive relaxation was not affected by H. pylori water extracts. In conclusion, indomethacin inhibited adaptive relaxation via prior gastric relaxation. NO production, but not COX-1 inhibition, may be involved in this effect of indomethacin. H. pylori water extracts may not have direct effects on adaptive relaxation. Inhibition of adaptive relaxation may be one of the major mechanisms underlying NSAID-induced dyspepsia.

Comparison of the effects of rebamipide with those of cimetidine on chronic gastritis associated with Helicobacter pylori in Mongolian gerbils

BACKGROUND AND AIMS

The effects of rebamipide on chronic gastritis associated with Helicobacter pylori have not been well-defined. We compared these effects of rebamipide with those of cimetidine in Mongolian gerbils infected with H. pylori.

METHODS

Mongolian gerbils with or without H. pylori were divided into 10 groups 6 weeks after inoculation and fed diets containing a drug (rebamipide or cimetidine) or control diet. All animals were sacrificed 4 weeks after grouping. Their stomachs were examined for histology, colonization by H. pylori, myeloperoxidase activity (myeloperoxidase), production of neutrophil chemokine (CINC/KC) and tumour necrosis factor-alpha (TNF-alpha), and serum gastrin levels.

RESULTS

H. pylori colonized all of the inoculated animals. Neither rebamipide nor cimetidine decreased myeloperoxidase activity, but each reduced wet stomach weight in H. pylori-infected animals. The amount of increase in CINC/KC and TNF-alpha in gastric tissue caused by H. pylori infection was decreased by treatment with rebamipide or cimetidine. H. pylori infection increased serum gastrin levels, and this increase was significantly enhanced by cimetidine but not rebamipide.

CONCLUSIONS

Rebamipide may improve H. pylori-infected chronic gastritis by preventing the production of inflammatory cytokines and chemokines, as does cimetidine, but may be preferable to cimetidine for long-term administration for treatment of H. pylori-infected chronic gastritis due to its effect on serum gastrin levels.

Effects of subglottal air pressure on velopharyngeal muscle activity in dogs

OBJECTIVE

To analyze the effects of airflow in the larynx on activity of the levator veli palatini and pterygopharyngeal muscles.

DESIGN

Ten adult beagle dogs were anesthetized with sodium pentobarbital. In each dog, two tracheal tubes were inserted subsequent to tracheotomy, one in the direction of the vocal folds and the other toward the lungs for respiration. In the first of three experiments, the effect of artificial airflow on electromyographic activity of the levator and pterygopharyngeal muscles was studied. In the second experiment, the effect of air pressure beneath the vocal folds on the activity of these muscles was studied. For the third experiment, the larynx was isolated surgically without cutting the bilateral superior laryngeal nerves and the effect of airflow through it examined.

RESULTS AND CONCLUSION

Both outward airflow and higher pressure enhanced expiratory activity of the levator and pterygopharyngeal muscles. Receptors in the subglottal area play major roles in this enhancement. Furthermore, an increase in air pressure during expiration enhances closure of the velopharynx.

STAT and SMAD signaling in cancer

STAT and SMAD often exert opposite biological effects on diverse cellular functions. Recent studies have shown that STAT can interface with SMAD at molecular level and that some novel molecules, such as SOCS (also called CIS) and APRO6 (also called TOB), modulate this signaling. A cofactor p300/CBP might act as a bridging molecule to mediate the interface. Thus, STAT and SMAD signaling pathways may crosstalk each other with interweaved regulatory mechanisms. Interestingly, the importance of all the proteins' function has been shown by the increasing evidence of their involvement in cancer. These recent progresses have been made in attributing novel exciting functions. Accordingly, we would like to review the latest advances of those pathways on a cross-section in cancer signaling.

Increased expression of epidermal growth factor receptors in basal cell hyperplasia of the oesophagus after acid reflux oesophagitis in rats

BACKGROUND

Epidermal growth factor (EGF), which binds to EGF receptors (EGF-R), stimulates oesophageal epithelial cell proliferation, enabling rapid repair after mucosal injury. In the normal human oesophageal epithelium, EGF-R expression is present and confined to the basal layer.

AIM

To examine histological changes in and dynamics of EGF-R expression during healing after acid reflux oesophagitis in a rat model.

METHODS

Gastric acid reflux oesophagitis was induced in Wistar rats by ligation of the pylorus and the transitional region between the forestomach and the grandular portion for 5 h, followed by release of both ligations. Rats were killed 7 and 14 days after production of oesophagitis to examine macroscopic and histological changes as well as dynamics of EGF-R expression. Epithelial cell proliferation was assessed by bromodeoxyuridine (BrdU) uptake, and expression of EGF-R mRNA and protein by RT-PCR and Western blotting or immunohistochemistry.

RESULTS

Gastric acid reflux induced erosive and ulcerative mucosal lesions in the lower and middle part of the oesophagus. These lesions were healed by 14 days and histologically showed thickening of the oesophageal epithelium from 41.11 +/- 3.09 microm in controls to 142.73 +/- 11.59 microm (P < 0.001) in ligated rats, as well as elongation of papillae and basal cell hyperplasia. The number of BrdU-positive cells among basal cells on day 14 was significantly increased from 7.1 +/- 0.8/field in controls to 30.9 +/- 3.0/field in ligated rats. Expression of EGF-R mRNA and protein was significantly increased on day 14 and most basal cells were immunohistochemically positive in both BrdU and EGF-R staining.

CONCLUSION

Acid reflux-induced oesophageal injury caused basal cell hyperplasia with an increase in cell proliferation and EGF-R expression. Activation of EGF-R gene and protein in response to acid reflux-induced injury may facilitate mucosal healing. These results suggest that epidermal growth factor receptors play a crucial role in healing after acid reflux oesophagitis in rats.

Cloning and sequencing of a novel human gene that encodes a putative target protein of Nesh-SH3

By using a conventional two-hybrid technique with an Src homology 3 (SH3) domain of Nesh as the bait protein, a novel full-length cDNA was isolated and sequenced from a human placenta cDNA library. This cDNA consists of 3023 bp and has a predicted open reading frame that encodes 486 amino acids. It possesses an SH3 binding motif, a nuclear targeting sequence, and no catalytic domain. Overall, it has no similarity to known molecules involved in a signaling cascade. Polymerase Chair reaction-based mapping with both a monochromosomal hybrid panel and radiation hybrid cell panels localized the gene on human chromosome 3q12 near the marker D3S1271.

Mechanisms and roles of neutrophil infiltration in stress-induced gastric injury in rats

Water-immersion and restraint stress is associated with an increase in neutrophil infiltration into the gastric mucosa, but the mechanism responsible for this infiltration is unclear. We investigated the involvement of intercellular adhesion molecule-1 (ICAM-1) and tumor necrosis factor-alpha (TNF-alpha) in neutrophil infiltration in stress-induced gastric injury in rats. Rats were administered neutralizing antibody against ICAM-1 or TNF-alpha and were subjected to induction of gastric injury by 6-hr water-immersion and restraint stress. To evaluate the relationship between gastric acid and neutrophil infiltration, some rats were given cimetidine before administration of stress. Neutralizing antibodies inhibited both the lesion formation and the increase in myeloperoxidase activity induced by stress. Expression of ICAM-1 on endothelial cells was increased by stress, accompanied by an increase of TNF-alpha-positive cells. Antibody against TNF-alpha inhibited this increase in ICAM-1 expression. Cimetidine almost completely inhibited gastric lesions, but did not affect myeloperoxidase activity. In conclusion, neutrophil infiltration in stress-induced gastric injury may be mediated by ICAM-1 and TNF-alpha, but not gastric acid, and may play crucial roles in the progression of gastric injury.

Intraductal papillary neoplasia of the liver associated with hepatolithiasis

Intraductal papillary growth of neoplastic biliary epithelia with a fine fibrovascular stalk (intraductal papillary neoplasia of liver [IPN-L]) resembling intraductal papillary mucinous neoplasm of pancreas is occasionally associated with hepatolithiasis. In this study, 136 cases of hepatolithiasis in Taiwan, between January 1998 and March 2000, and an additional 21 cases of IPN-L before December 1998, were examined histologically. IPN-L was found in 41 of 136 hepatolithiasis cases (30.1%). Sixty-two IPN-L cases (42 women and 20 men; age range, 59.8 +/- 10 years) were divided into 4 types (type 1, IPN-L with low-grade dysplasia, 23 cases; type 2, IPN-L with high grade dysplasia, 11 cases; type 3, IPN-L with in situ and microinvasive carcinoma, 13 cases; and type 4, IPN-L of types 2 and 3 with distinct invasive carcinoma, 15 cases). Intraductal spreading and glandular involvement were commonly observed in all types. About half of types 3 and 4 cases had mucobilia, and mucinous carcinoma was variably found in two thirds of group 4 patients. IPN-L frequently showed variable gastroenteric differentiation such as goblet cells and foveolar and colon-like metaplasia. IPN-L with goblet cells and colon-like metaplasia was frequently associated with overproduction of mucin and mucobilia (P <.01). In Japan, IPN-L was not frequent in hepatolithiasis (12 of 135 cases). In conclusion, IPN-L forms a spectrum of biliary neoplasm in hepatolithiasis. It often displays variable gastroenteric metaplasia and significant intraductal spread. IPN-L tends to progress to mucinous carcinoma. Formerly reported "mucin-producing intrahepatic cholangiocarcinoma" with a favorable prognosis is included in IPN-L.

Ras/MAP kinase pathway is associated with the control of myotube formation but not myofibril assembly in quail myoblasts transformed with Rous sarcoma virus

Tyrosine kinase activity of v-Src from Rous sarcoma virus (RSV) inhibits the differentiation of quail myoblasts. To clarify the inhibitory mechanism, we focused on the signaling pathways from v-Src. When the activation of the Ras/MAP (mitogen-activated protein) kinase pathway was inhibited by a dominant-negative mutant of Ras or PD98059, a specific inhibitor of p42 MAP kinase kinase, differentiation was restored; muscle specific proteins were expressed and myotubes formed even under active conditions of v-Src. Wortmannin, a specific inhibitor of phosphatidylinositol 3-kinase (P13-kinase), showed no effects on the inhibition by v-Src. These findings suggest that v-Src activates the Ras/MAP kinase signaling pathway, but not the P13-kinase pathway, and inhibits the differentiation. However, the myotubes derived from the dominant-negative Ras did not form actin fibers, suggesting that myofibril assembly is regulated by other pathway(s) from v-Src.

Cloning and sequencing of a novel human gene which encodes a putative hydroxylase

Using a conventional two-hybrid technique with MAWD as bait protein, a novel full-length cDNA was isolated and sequenced from a human liver cDNA library. This cDNA consists of 2,575 base pairs and has a predicted open reading frame encoding 255 amino acids. Overall, it is similar to the catalytic enzyme PHZF, catalyzing the hydroxylation of phenazine-1-carboxylic acid to 2-hydroxyphenazine-1-carboxylic acid. Polymerase chain reaction-based mapping with both a monochromosomal hybrid panel and radiation hybrid cell panels placed the gene to human chromosome 10q21.1 near the marker D10S210.