335EFFECT OF PATERNAL LINE OF DONOR ON SUPEROVULATORY RESPONSE AND EMBRYO QUALITY IN JAPANESE BLACK HEIFERS

The objective of this study was to investigate the effect of paternal line of donor on superovulatory response and embryo quality in Japanese Black cattle. Japanese Black cattle have paternal lines that can be classified into the following, according to meat quality and the growth rate: ‘high marbling meat type’, ‘high growth rate type’ and ‘high marbling meat and high growth rate (intermediate type)’. We hypothesized that paternal line of donor may affect superovulatory response. One hundred and forty superstimulations were performed on 56 Japanese Black heifers, and data on superovulatory response and embryo collection were analyzed. Japanese Black donors used in this study were from the following 4 paternal lines: Kedaka (large-framed with high growth rate;; n=9, 30 times), Fujiyoshi (intermediate type;; n=22, 47 times), Shigekane (high marbling meat type;; n=13, 40 times), and Tajiri (high marbling meat type and small-frame with slow growth rate;; n=12, 23 times). Donors were synchronized using a CIDR-B (EAZI-BREED, InterAg, NZ) for 8 to 12 days, and 500μg PGF analog (Resipron-C; Teikoku Zouki, Japan or Clopromate-C; Sumitomo, Japan) administered at CIDR removal. Superstimulation was initiated on Day 10 (Day 0=day of estrus) of the synchronized cycle;; FSH (Antrin R10;; Denka, Japan) was administered twice daily for 4 days with decreasing doses for a total of 28 Armour units FSH. PGF analog was administered in the morning on the last day of FSH treatment. Donors were given 50 or 100μg GnRH analog (Sporunen, Denka, or Conceral, Takeda Schering prau, Japan) at the time of estrus detection, and were inseminated 12h after the onset of estrus. Embryos were recovered on Day 7 after AI. The numbers of CL and follicles were recorded with transrectal ultrasonography immediately after embryo recovery. Embryos were classified according to the IETS Manual. Data were analyzed by Kruskal-Wallis test combined with Scheffe’s multiple comparison test. There were no significant differences in CL numbers among paternal lines: Kedaka (9.5±4.2), Fujiyoshi (8.5±5.1), Shigekane (7.8±5.0) and Tajiri (8.6±4.1). Mean number of recovered ova/embryos per donor was significantly (P<0.05) higher in the Kedaka line (8.4±5.1) than in the Fujiyoshi (4.9±4.1) and Shigekane (5.5±7.0) lines. The percentages of viable embryos was greater (P<0.05) in the Fujiyoshi (73.7%) and Shigekane lines (62.8%) than in the Tajiri line (50.9%), whereas the percentage of unfertilized oocytes was significantly (P<0.05) higher in the Tajiri line (41.5%) than in the Fujiyoshi (17.5%) or Shigekane (26.1%) lines. The percentages of freezeable and transferable embryos were not significantly different among paternal lines. Data suggest that the paternal line had an effect on the superstimulatory response in Japanese Black heifers, and especially the number and percentage of viable embryos per donor.

No major tumorigenic role for beta-catenin in serrated as opposed to conventional colorectal adenomas

Intracellular redistribution of beta-catenin through mutation of the adenomatous polyposis coli (APC) gene has been proposed as an early tumorigenic event in most colorectal tumours. In serrated adenoma (SA), a newly recognised subtype of colorectal adenoma, APC mutations are uncommon, and the contribution of beta-catenin to tumorigenesis remains unclear. We compared intracellular localisation of beta-catenin and presence of mutations in exon 3 of beta-catenin between 45 SAs, with 71 conventional adenomas (CADs), and eight carcinomas invading the submucosa (SCAs). Widespread or focal nuclear beta-catenin expression was demonstrated in 7% of SAs (three out of 45), 61% of CADs (43 out of 71), and 88% of SCAs (seven out of eight). Cytoplasmic immunostaining for beta-catenin was demonstrated in 16% of SAs (seven out of 45), 77% of CADs (55 out of 71), and 88% of SCAs (seven out of eight). No mutation in exon 3 of beta-catenin was found in SAs or SCAs, while 7% of CADs (five out of 71) had beta-catenin mutations. No nuclear or cytoplasmic expression of beta-catenin was observed in the hyperplastic or conventionally adenomatous epithelium of mixed-type SAs. These findings suggest that beta-catenin mutation is unlikely to contribute to the tumorigenesis in SA, and that intracellular localisation of beta-catenin may not be associated with an early event of the tumour progression in most SAs.

Definitive chemoradiotherapy for patients with malignant stricture due to T3 or T4 squamous cell carcinoma of the oesophagus

We retrospectively investigated the efficacy and feasibility of concurrent chemoradiotherapy for patients with severe dysphagia caused by oesophageal squamous cell carcinoma. Concurrent chemoradiotherapy was performed in 57 patients with T3 or T4 disease containing M1 lymph node (LYM) disease. Chemotherapy consisted of protracted infusion of 5-fluorouracil (5-FU) 400 mg m(-2) 24 h(-1) on days 1-5 and 8-12, combined with 2-h infusion of cisplatin (CDDP) 40 mg m(-2) on days 1 and 8. Radiation treatment at a dose of 30 Gy in 15 fractions of the mediastinum was administered concomitantly with chemotherapy. A course schedule with 3-week treatment and a 1 to 2-week break was applied twice, with a total radiation dose of 60 Gy, followed by two or more courses of 5-FU and CDDP. In all, 24 patients (42%) achieved a complete response, and the 3-year survival rate was 19%. Major toxicities were leukocytopenia and oesophagitis, and there were two (4%) treatment-related deaths. In contrast, 22 patients with T3 disease survived longer than 35 patients with T4 disease (P=0.001); however, the survival rate in 15 patients with M1 LYM disease did not differ significantly from that in 42 patients without M1 LYM disease (P=0.3545). Our results indicate that definitive chemoradiotherapy is potentially curative for locally advanced oesophageal carcinoma with malignant stricture. The efficacy and survival of patients treated with this regimen are related to the T factor.

Plural transformation-processes from spiral to coccoid Helicobacter pylori and its viability

OBJECTIVES

Helicobacter pylori (H. pylori), present in a half of the world's population, is a very successful pathogen. The infection by this bacterium causes several gastric diseases in human. H. pylori is morphologically divided into two types; a spiral and a coccoid form. Both types are observed in human stomach. Although the former is converted into the latter in vitro, the process of coccoid formation remains obscure. Furthermore, whether coccoid forms possess viability arouses much controversy among scientists. We investigated both the process of coccoid formation by electron microscopy and the viability of coccoid H. pylori.

METHODS

A laboratory strain, ATCC43504, was cultured in liquid medium (Brucella Broth medium with 10% heat inactivated horse serum) for seven days. In each culture day, the organisms were observed by scanning-, conventional transmission- and immuno-electron microscopy and were simultaneously examined the culturability of H. pylori to identify the viability of coccoid form.

RESULTS

As the days went by, spiral forms were replaced by coccoid forms in each medium which possessed culturability to some degree until the 4th day. By the detailed observation of ultrastructural features, coccoid forms were classified into two types on the ground that represents different transformation-processes and distinctive ultrastructures. One was the coccoid form that we named Type A with an irregularly surface- and intracytoplasmic-structure which adhered to one another. The other was Type B having a smooth surface with flagella coiled around its own body and the strictly membranous structure. This type was not adhered to another organism. In later days, each type came to be similar external structure and lost the culturability.

CONCLUSIONS

The coccoid forms of H. pylori can be classified into two types by electron microscopy which represent different transformation-processes and consist of the dying bacteria, the living ones with culturability and the viable but non-culturable ones.

Early experiences of endoscopic procedures in general surgery assisted by a computer-enhanced surgical system

We performed a variety of complete total endoscopic general surgical procedures, including colon resection, distal gastrectomy, and splenectomy, successfully with the assistance of the da Vinci computer-enhanced surgical system. The robotic system allowed us to manipulate the endoscopic instruments as effectively as during open surgery. It enhanced visualization of both the operative field and precision of the necessary techniques, as well as being less stressful for the endoscopic operating team. This technological innovation can therefore help surgeons overcome many of the difficulties associated with the endoscopic approach and thus has the potential to enable more precise, safer, and more minimally invasive surgery in the future.

New and better protocols for a short-term Caco-2 cell culture system

The aim of the present study was to develop new and better protocols for a short-term Caco-2 cell culture system for use in rapid screening of intestinal drug absorption. Caco-2 cells were cultured according to several protocols for short-term cell culture to obtain monolayers. The effects of serum (fetal bovine serum, FBS) in the culture medium and of the period of cell culture on the barrier function and transporter activities of the monolayers were examined. The barrier function was estimated both from the transepithelial electrical resistance (TEER) and the permeability of [(14)C]mannitol. Transporter activities were monitored by measuring the permeability of [(14)C]glycylsarcosine for oligopeptide transporter (PepT1) and of rhodamine 123 for P-glycoprotein (P-gp). Caco-2 monolayers obtained by 3-day culture in the BIOCOAT HTS Caco-2 Assay System, developed by Becton Dickinson Bioscience, showed much higher permeability to hydrophilic compounds, such as mannitol, compared with those obtained by the standard 21-day culture system, due to the leaky structure of cell junctions. The newly developed 3-day protocol, which includes 10% FBS in the culture medium during the first day of culture, markedly enhanced TEER and lowered mannitol permeability of the monolayers. This protocol allowed us to better determine the rank order of permeability of compounds, giving results equivalent to those in the 21-day culture system. The longer culture period gave tighter monolayers, and the maximum value of TEER was obtained with 5 days in culture. However, after 5 days in culture, the integrity of monolayers decreased gradually. The highest activities of transporters, PepT1 and P-gp, in monolayers were obtained at days 5 or 6 of culture by the new protocol with FBS-containing medium. These results indicate that by a simple modification of the short-term culture protocol, it is possible to obtain Caco-2 monolayers with better barrier properties and higher activity of transporters that are equivalent to those found in the 21-day Caco-2 culture system.

[A case of extensive Fournier's gangrene]

A 52-year-old man was admitted to our hospital complaining of high grade fever and painful swelling of the scrotum. Although debridement of the scrotum and inguinal region was immediately carried out, the inflammation extended to the right abdominal region 2 days later. We tunneled the newly infected areas and placed Penrose drains through the tunnels, so that complete drainage was achieved with minimal tissue loss. The infection was controlled by frequent irrigation of the wound and antibiotic administration. Forty days after the admission the defect of the skin was reconstructed by using a meshed skin graft, and the patient was discharged on the 68th hospital day. We concluded that limited debridement with placement of through-and-through drains might have produced a good result with minimal tissue loss.

Histological findings after placement of a self-expanding stent in rectal carcinoma with complete obstruction--case report

Patients with acute obstruction due to colorectal carcinomas frequently require emergency surgery. However, such emergency procedures are associated with various complications, a high mortality rate and a poor prognosis. If the obstruction could be immediately relieved, the patient could later undergo an elective operation with a much better prognosis. Recently, expanding metallic stents have been used to treat obstruction due to colorectal carcinoma. In the case reported here, we initially inserted a colonoscopic retrograde bowel drainage tube per anus to achieve decompression. We then placed a self-expanding metallic stent, since we anticipated a prolonged preoperative period due to high fever, congestive heart failure, cerebral infarction, and persistent high blood sugar concentrations. The patient had no complications for 57 days after placement of the stent, and eventually underwent an elective operation. Histologically, the side of the cancerous lesion compressed by the stent was thin and consisted solely of a serosal layer. Implantation of a metallic stent is safe for the treatment of acute malignant obstruction. Stent placement is indicated not only as a palliative treatment for inoperable or recurrent cases, but also as a preoperative procedure before elective surgical resection.

Reconstitution and purification of cytolethal distending toxin of Actinobacillus actinomycetemcomitans

Cytolethal distending toxin (CDT) has been found in various pathogenic bacterial species and causes a cell distending and a G2 arrest against eukaryotic cells. All the cdtABC genes, which encode CDT, are known to be required for the CDT activities although the CDT holotoxin structure has not been elucidated. We cloned the cdtABC genes of Actinobacillus actinomycetemcomitans and constructed an Escherichia coli expression system for them. We found that crude extracts from six deletion mutants (delta cdtA, delta cdtB, delta cdtC, delta cdtBC, delta cdtAC, and delta cdtAB) of recombinant E. coli, which showed very weak or no detectable CDT activities, restored the CDT activities when pre-mixing and pre-incubation of them were performed in combinations to contain all the CdtA, CdtB, and CdtC proteins. These results indicate that all the Cdt proteins are required for the CDT activities. We also found that the chimera CdtB protein, CdtB-intein-CBD (chitin binding domain) like CdtB protein itself assembled with CdtA and CdtC. The reconstituted CDT containing the chimera CdtB protein was specifically extracted by chitin beads and the only CDT portion was isolated from the chitin beads by a cleavage reaction of the intein. The purified reconstituted-CDT was found to consist of CdtA, CdtB, and CdtC proteins, and showed appreciable CDT activities, indicating that the CDT holotoxin structure is the CdtABC complex. To our knowledge, this is the first report succeeded in complete purification of an active CDT and may offer useful tools for elucidation of the toxic mechanism of CDT.

Histopathological studies on virulence of dipeptidyl aminopeptidase IV (DPPIV) of Porphyromonas gingivalis in a mouse abscess model: use of a DPPIV-deficient mutant

To elucidate the role of dipeptidyl aminopeptidase IV (DPPIV) in the virulence of Porphyromonas gingivalis, mice were infected with either a wild-type strain or a DPPIV-deficient mutant using an abscess model. Histopathological analysis of the resulting lesions indicated that DPPIV participates in virulence through the destruction of connective tissue and the less effective mobilization of inflammatory cells.

p53 immunoreactivity in Barrett's metaplasia, dysplasia, and adenocarcinoma--a case report

Barrett's esophagus is a condition in which the stratified squamous epithelium of the esophagus is replaced by a columnar epithelium with malignant potential. Mutations of the tumor-suppressor gene p53 have been implicated in the evolution of esophageal carcinomas. The aim of this study was to determine whether p53 immunoreactivity in Barrett's esophagus is a marker of neoplasia and, if so, when it occurs in the metaplasia-dysplasia-carcinoma sequence. We treated a patient with esophageal carcinoma arising from the Barrett's esophagus. Consecutive evidence existed for a metaplasia-dysplasia-carcinoma in the same specimen. Immunohistochemical staining with the monoclonal antibody was used to detect the intranuclear protein product of mutated p53. No p53 immunoreactivity was seen in specimen of Barrett's mucosa. p53 immunoreactivity was found only in specimen of dysplasia and carcinoma. Immunoreactivity occurs late in the metaplasia-dysplasia-carcinoma sequence, during the transition to high-grade dysplasia.

Inhibition of HIV-1 infection by synthetic peptide analogues derived from the NH(2)-Terminal extracellular region of GPR1

Several shortened peptide analogues of the N-terminal domain of GPR1, an orphan G protein-coupled receptor (GPCR), were prepared and their anti-HIV-1 activities were evaluated. Some of the prepared compounds, especially sulfated derivatives, showed potent inhibitory activity against a broad range of HIV-1, including T cell-tropic, dual cell-tropic and brain-derived (BT) cell-tropic HIV-1 strains.

[Significance of radical recurrent tumor resection for recurrent gastric cancer as assessed by prognosis]

To evaluate the relationship between radical surgery of recurrent tumor and prognosis in cases of recurrent gastric cancer, we analyzed data on 202 patients with relapsed gastric cancer, focusing on surgical recurrent tumor removal. In our series, 18 of the 202 patients underwent radical recurrent tumor resection. Resected tumors were located in the ovarium (n = 4), colorectum (n = 3), liver (n = 3), lymph node (n = 2), locoregional stoma (n = 2), and peritoneum, adrenal gland, brain, and lung (n = 1 each). No surgery-related mortality occurred. One patient remains alive over 5 years after hepatectomy without recurrence, and 17 died within 3 years: 7 patients from primary recurrence and 10 from multiple modes of recurrence. Median survival after recurrence (MSTAR) in the 18 radical surgery patients was 14 months, against 5 months in those treated palliatively (p = 0.0001). MSTAR for the ovary and the liver were 30 months and 15 months in the radical surgery cases, and 2.5 months for the ovary and 5 months for the liver in the palliative cases. Significant differences were thus seen between radical and palliative cases in the ovary (p = 0.010) and in the liver (p = 0.036). Median survival after gastrectomy was 45 months in the radical surgery cases, and 28 months in the palliative cases (p = 0.024). In postoperative gastric cancer follow-up, early detection of recurrence and radical surgery may well benefit patients with relapse, especially in the liver and ovary, in terms of survival.

[Current status and future of surgical robotic systems]

In this review, we are commenting the current status and the future of surgical robotic systems. AESOP is a voice-controlled laparoscope manipulator that enables the "Solo-surgery". ZEUS is a master-slave manipulator that is characterized by its simplicity and lightness. da Vinci is another master-slave manipulator that has more range of freedom, therefore a surgeon can perform the operation with fewer difficulties. The technological development of high-quality and real-time 3D simulation, minimization of scopes and power saving techniques made these surgical robots realized. Although many pending matters such as lack of safety guideline or lack of accuracy of sensor/monitor have been raised in current surgical robotics, the development of the technologies may promise to resolve such matters in the future.

[A case of esophageal carcinoma with multiple liver metastases successfully treated with nedaplatin (NDP) and 5-fluorouracil (5-FU) combined with radiotherapy]

A 78-year-old male patient had esophageal carcinoma with multiple liver metastases. Chemoradiotherapy was performed. The chemotherapy consisted of protracted infusion of 5-fluorouracil (5-FU), combined with infusion of nedaplatin (NDP). Radiation of the mediastinum was administered concomitantly with chemotherapy. The patient showed a complete response (CR) of the primary lesion and a partial response (PR) of the liver metastasis for 11 months. Since liver metastasis recurred after initial treatment, chemotherapy consisting of NDP infusion combined with vindesine sulfate (VDS) infusion was performed. The patient again showed PR. Grade 3 leukocytopenia occurred during treatment, but there were no major toxicities such as thrombocytopenia, nausea, renal dysfunction or esophagitis. Survival time was one year and 7 months. In conclusion, concurrent chemoradiotherapy including NDP is effective and safe for patients with esophageal carcinoma accompanied by multiple liver metastasis. This nonsurgical approach may be an option for standard care in such cases.

Discovery of a non-peptide small molecule that selectively mimics the biological actions of calcitonin

Calcitonin (CT), a 32-amino acid peptide hormone secreted mainly from the thyroid gland, plays an important role in maintaining bone homeostasis. To discover non-peptide small molecules with biological actions similar to those of CT, a cell-based screening of an in-house chemical library was performed and a pyridone derivative (SUN B8155) was identified. Like CT, it elevated cyclic AMP (cAMP) levels in T47D and UMR106-06 cells which endogenously express human and rat CT receptor, respectively. SUN B8155 also stimulated cAMP formation in cells expressing recombinant human CT receptor, but not in those expressing human parathyroid hormone/parathyroid hormone-related peptide receptor. Accumulation of cAMP in T47D cells was blocked by a selective antagonist of CT receptor, salmon CT(8-32), whereas SUN B8155 did not displace the specific binding of [(125)I]CT to the receptor. Our results suggested that the compound selectively interacts with the CT receptor by a mechanism similar to but probably different from that of CT itself. In rats, intraperitoneal administration of SUN B8155 significantly lowered serum calcium levels, like CT. Our results demonstrate, for the first time, that the biological activities of the newly identified small molecule can mimic that of CT, acting via the CT receptor.

Acute urticaria with elevated circulating interleukin-6 is resistant to anti-histamine treatment

Histamine released from dermal mast cells plays a central role in the increased vascular permeability in acute urticaria, and administration of anti-histamines usually suppresses development of wheals. Acute idiopathic urticaria, particularly a severe case, occasionally presents with acute inflammatory reactions such as low-grade fever and leukocytosis and is resistant to anti-histamines. Considering the wide spectrum of proinflammatory cytokines and chemokines that can be released from activated mast cells, some of them might be involved in the pathogenesis of urticaria. We measured plasma levels of interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor-alpha (TNF-alpha) in 16 cases of severe acute urticaria. None of them showed elevated plasma levels of IL-8 or TNF-alpha. Nine out of 16 acute urticaria patients showed elevated circulating IL-6 with concomitant increases in serum CRP levels. All such patients were resistant to conventional anti-histamine treatment and required systemic steroids for complete suppression of wheal development. After subsidence of the urticaria, their elevated IL-6 and CRP levels dropped to their normal ranges. In contrast, all but one patient without elevated circulating IL-6 was successfully treated with a H1 receptor antagonist, cetirizine. The data suggest involvement of IL-6 in the pathogenesis of severe acute urticaria that is resistant to anti-histamines.

Prognostic value of p53 mutations in patients with locally advanced esophageal carcinoma treated with definitive chemoradiotherapy

PURPOSE

A significant correlation has been found between p53 mutation and response to chemotherapy or radiotherapy. To determine the prognostic value of p53 mutation in patients with locally advanced esophageal carcinoma treated with definitive chemoradiotherapy, p53 mutation was analyzed using the biopsied specimens taken for diagnosis.

METHODS

Concurrent chemoradiotherapy was performed for 40 patients with severe dysphagia caused by esophageal squamous cell carcinoma associated with T3 or T4 disease. Chemotherapy consisted of protracted infusion of 5-fluorouracil, combined with an infusion of cisplatinum. Radiation treatment of the mediastinum was administered concomitantly with chemotherapy. The p53 gene mutation was detected by fluorescence-based polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) methods. DNA sequences were determined for DNA fragments with shifted peaks by SSCP methods.

RESULTS

Of the 40 patients, 15 had T3 disease and 25 had T4 disease; 11 patients had M1 lymph node (LYM) disease. Of the 40 patients, 13 (33%) achieved a complete response. The median survival time was 14 months, and the 2-year survival rate was 20%. Among the 40 tumor samples, p53 mutation was detected in 24 tumors (60%). The survival rate in the 24 patients with p53 mutation did not differ significantly from that in the 16 patients without p53 mutation. In contrast, the 15 patients with T3 disease survived longer than the 25 patients with T4 disease (P = 0.016); however, the survival rate in the 11 patients with M1 LYM disease did not differ significantly from that in the 29 patients without M1 LYM disease.

CONCLUSION

Concurrent chemoradiotherapy is potentially curative for locally advanced esophageal carcinoma, but p53 genetic abnormality has no impact on prognosis.

A specific thrombin inhibitor, argatroban, alleviates herpes zoster-associated pain

We report the result of a randomized, controlled, open trial of anti-thrombin therapy for herpes zoster-associated pain. Fifty-five herpes zoster patients within 8 days after the onset of skin lesion were enrolled in the trial. Patients were treated with an optimal dose of oral acyclovir (4000 mg/day for 7 days) with or without intravenous administration of a specific anti-thrombin agent, argatroban (10 mg/day, three times a week). Administration of argatroban reduced pain intensity at the 4th through 21st day after the initiation of treatment as determined by visual analogue scale (Mann-Whitney U test, p < 0.05). It also shortened the median time to cessation of analgesic use (14 days vs. 24 days, p = 0.02, logrank test), although it did not significantly reduce the median time to cessation of pain (21 days vs. 43 days, p = 0.07, logrank test). None of the enrolled patients showed evidence of adverse effects including hemorrhagic diathesis. The results suggested that relatively low doses of argatroban are effective in reducing herpes zoster-associated pain. Up-regulation of prothrombin expression by the vascular endothelial and sweat gland epithelial cells in the active skin lesion and transient elevation of plasma thrombin-antithrombin III complex levels in a proportion of patients suggest a lesional generation of thrombin in herpes zoster. This may be relevant to the beneficial effects of the anti-thrombin treatment on the resolution of herpes zoster-associated pain.

Prognostic significance of expression of thymidine phosphorylase and vascular endothelial growth factor in human gastric carcinoma

BACKGROUND AND OBJECTIVES

Both thymidine phosphorylase (dThdPase) and vascular endothelial growth factor (VEGF) are well-characterized inducers of angiogenesis. The purpose of this study was to examine the expression of these antigens and their prognostic significance in gastric carcinoma.

METHODS

Medical records of 102 patients with stage II tumor were retrospectively reviewed. Primary tumors were studied by immunohistochemical staining for dThdPase and VEGF.

RESULTS

Positive dThdPase expression was observed in 52 (51%) tumors and positive VEGF expression in 53 (52%) tumors. There was a significant correlation between the positive expression of VEGF and lymphatic invasion. The patients with dThdPase-positive carcinoma showed a significantly worse prognosis than those with dThdPase-negative carcinoma in stage II. Moreover, the frequency of hepatic recurrence was significantly higher in the patients with dThdPase-positive and VEGF-positive tumors than in those with dThdPase-negative and VEGF-negative tumors.

CONCLUSIONS

Combination analysis of dThdPase and VEGF expression in gastric carcinoma appears to be well-characterized inductors of prognosis and metastasis.

Two new modes of smooth muscle myosin regulation by the interaction between the two regulatory light chains, and by the S2 domain

Previous studies indicated that single-headed smooth muscle myosin and S1 (a single head fragment) are not regulated through phosphorylation of the regulatory light chain (RLC). To investigate the importance of the double-headedness of myosin and of the S2 region for the phosphorylation-dependent regulation, we made three types of recombinant mutant smooth muscle HMMs with one intact head and an N-terminally truncated head. The truncated head of Delta MD lacked the motor domain, that of Delta(MD+ELC) lacked the motor and essential light chain binding domains, and single-headed HMM had one intact head alone. The basal ATPase activities of the three mutants decreased as the KCl concentration became less than 0.1 M. Such a decrease was not observed for S1, which had no S2 region, suggesting that S2 is necessary for this myosin behavior. This activity decrease also disappeared when RLCs of Delta MD and Delta(MD+ELC), but that of single-headed HMM, were phosphorylated. When their RLCs were unphosphorylated, the three mutants exhibited similar actin-activated ATPase levels. However, when they were phosphorylated, the actin-activated ATPase activities of Delta MD and Delta(MD+ELC) increased to the S1 level, while that of single-headed HMM remained unchanged. Even in the phosphorylated state, the actin-activated ATPase activities of the three mutants and S1 were much lower than that of wild-type HMM. We propose that S2 has an inhibitory function that is canceled by an interaction between two phosphorylated RLCs. We also propose that a cooperative interaction between two motor domains is required for a higher level of actin activation.