Predictive factors for malignancy in intraductal papillary-mucinous tumours of the pancreas

BACKGROUND

Preoperative assessment of the likelihood of malignancy in intraductal papillary-mucinous tumour (IPMT) of the pancreas is often difficult. Predictive factors for malignancy and invasive carcinoma in IPMT were analysed.

METHODS

Sixty-two patients with IPMT underwent surgical treatment, with histological confirmation of adenoma in 28, carcinoma in situ in 14 and invasive carcinoma in 20. Tumours were of the main duct type in 14 patients, branch duct type in 32, and combined type in 16. A multivariate analysis of 17 potential predictive factors, including preoperative clinical and imaging findings, was conducted.

RESULTS

Multivariate analysis identified two independent predictive factors for malignancy: mural nodules and main pancreatic duct diameter of 7 mm or more. Mural nodules in the main duct or combined type, and mural nodules and tumour diameter of 30 mm or more in the branch duct type were particularly indicative of malignancy. Mural nodules, jaundice and main duct or combined type were predictors of invasive carcinoma in the multivariate analysis.

CONCLUSION

The above factors should be considered in the diagnosis of IPMT to facilitate appropriate management.

Intraductal papillary mucinous tumors of the pancreas: imaging studies and treatment strategies

OBJECTIVE

We analyzed clinicopathologic and imaging features and the prognosis of intraductal papillary mucinous tumor (IPMT) of the pancreas to identify imaging findings indicative of malignancy and to establish the optimal treatment strategy.

SUMMARY BACKGROUND DATA

In IPMT, preoperative differentiation between adenoma and adenocarcinoma is often difficult. Appropriate treatment based on pathologic study and surgical outcome has not been adequately documented.

METHODS

Forty-one patients with IPMT underwent surgery; 15 with adenoma and 26 with adenocarcinoma; main duct type in 13, combined type in 12, and branch duct type in 16.

RESULTS

In malignant IPMT, deep invasion was found in 62% and lymph node metastasis in 23% (peripancreatic nodes in 19% and distant nodes in 4%). Tumors with mural nodules (86%) had a significantly higher incidence of carcinoma than tumors without nodules (37%). IPMT with a main pancreatic duct > or =15 mm or tumor diameter > or =30 mm (branch duct type) showed a high prevalence of adenocarcinoma. Main duct (54%) and combined (58%) type tumor, and tumors with mural nodules (64%) often showed invasion. All five branch duct tumors less than 30 mm without nodules were adenomas. However, imaging studies could not definitely distinguish adenocarcinomas from adenomas. Complete resection was possible for all adenomas and 88% of adenocarcinomas. Five-year survival rates for patients with adenomas and adenocarcinomas were 100% and 82%, respectively.

CONCLUSIONS

IPMT has a favorable prognosis, regardless of deep invasion or node metastasis. IPMT requires peripancreatic node dissection in addition to complete tumor excision. Node dissection may be omitted for branch duct tumors less than 30 mm without mural nodules.

Compactin and simvastatin, but not pravastatin, induce bone morphogenetic protein-2 in human osteosarcoma cells

Bone morphogenetic protein (BMP)-2, a member of the BMP family, plays an important role in osteoblast differentiation and bone formation. To discover small molecules that induce BMP-2, a luciferase reporter vector containing the 5'-flanking promoter region of the human BMP-2 gene was constructed and transfected into human osteosarcoma (HOS) cells. By the screening of an in-house natural product library with stably transfected HOS cells, a fungal metabolite, compactin, known as an inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, was isolated. The stimulation of the promoter activity by compactin seemed to be specific for BMP-2 gene in HOS cells, since it had little effect on BMP-4 or SV40 promoter activity and the stimulation was not observed in Chinese hamster ovary (CHO) cells. RT-PCR analysis and alkaline phosphatase assay revealed that compactin induced an increase in the expression of BMP-2 mRNA and protein. Like compactin, simvastatin also activated the BMP-2 promoter, whereas pravastatin did not. The statin-mediated activation of BMP-2 promoter was completely inhibited by the downstream metabolite of HMG-CoA reductase, mevalonate, indicating that the activation was a result of the inhibition of the enzyme. These results suggest that statins, if they are selectively targeted to bone, have beneficial effects in the treatment of osteoporosis or bone fracture.

2017 publication guidelines for structural modelling of small-angle scattering data from biomolecules in solution: an update

In 2012, preliminary guidelines were published addressing sample quality, data acquisition and reduction, presentation of scattering data and validation, and modelling for biomolecular small-angle scattering (SAS) experiments. Biomolecular SAS has since continued to grow and authors have increasingly adopted the preliminary guidelines. In parallel, integrative/hybrid determination of biomolecular structures is a rapidly growing field that is expanding the scope of structural biology. For SAS to contribute maximally to this field, it is essential to ensure open access to the information required for evaluation of the quality of SAS samples and data, as well as the validity of SAS-based structural models. To this end, the preliminary guidelines for data presentation in a publication are reviewed and updated, and the deposition of data and associated models in a public archive is recommended. These guidelines and recommendations have been prepared in consultation with the members of the International Union of Crystallography (IUCr) Small-Angle Scattering and Journals Commissions, the Worldwide Protein Data Bank (wwPDB) Small-Angle Scattering Validation Task Force and additional experts in the field.

Endoscopic ultrasonography for diagnosing choledocholithiasis: a prospective comparative study with ultrasonography and computed tomography

BACKGROUND

We assessed the diagnostic usefulness of endoscopic ultrasonography (EUS) for choledocholithiasis.

METHODS

A prospective series of 155 patients with suspected choledocholithiasis all underwent EUS, conventional ultrasonography, CT, and ERCP. In 142 patients with a clear cholangiogram on ERCP, we analyzed the capability of EUS to image the extrahepatic bile duct and to identify choledocholithiasis, compared with ultrasonography and CT.

RESULTS

No complications were encountered in performing EUS. In 51 patients, ERCP demonstrated bile duct stones, which were confirmed at endoscopic sphincterotomy or surgery. The extrahepatic bile duct was wholly displayed in 96% by EUS, in 60% by ultrasonography, and in 80% by CT. EUS (96%) was more sensitive than ultrasonography (63%) and CT (71%) for detecting choledocholithiasis (p < 0.001). Although ultrasonography and CT were poorly diagnostic for choledocholithiasis in patients with small stones or those with a nondilated common bile duct, EUS was able to accurately detect choledocholithiasis regardless of the size of stones or the diameter of the bile duct. The specificity of EUS (100%) was higher than those of ultrasonography (95%) and CT (97%).

CONCLUSIONS

EUS, a safe imaging procedure, is more accurate than ultrasonography and CT and may be as accurate as ERCP for diagnosing choledocholithiasis.

Baddeleyite-Type High-Pressure Phase of TiO2

A high-pressure phase of TiO(2), which had been observed by shock-wave experiments and remained unresolved, has been studied by in situ x-ray diffraction. The single phase was formed at 20 gigapascals and 770 degrees C with the use of sintered-diamond multianvils; it has the same structure as baddeleyite, the stable phase of ZrO(2) at ambient conditions. The coordination number of Ti increases from six to seven across the rutile to baddeleyite transition, and the volume is reduced by approximately 9 percent.

Extrapancreatic neoplasms occur with unusual frequency in patients with intraductal papillary mucinous tumors of the pancreas

OBJECTIVE

Intraductal papillary mucinous tumor (IPMT) of the pancreas has a favorable prognosis. Non-pancreatic primary neoplasms have potential prognostic significance in patients with IPMT. This study focused on the incidence and characteristics of nonpancreatic neoplasms in IPMT patients.

METHODS

Forty-two patients (mean age, 64 yr) with IPMT underwent surgery; 16 had adenoma and 26 adenocarcinoma. Preoperative and postoperative, nonpancreatic neoplasms were investigated. The mean postoperative follow-up period was 4.2 yr (range, 0.2-13 yr). Furthermore, 46 patients with pancreatic ductal adenocarcinoma were analyzed for nonpancreatic neoplasms.

RESULTS

Five-year survival rates were 100% for benign and 82% for malignant IPMT. Twenty patients (48%) had nonpancreatic neoplasms, before (n = 11), at (n = 4), and after (n = 10) surgery for IPMT. Fifteen patients (32%) had nonpancreatic malignancies. Nonpancreatic neoplasms included colorectal adenomas (21%) and adenocarcinomas (12%), and gastric carcinomas (10%). One patient died of subsequent bile duct carcinoma. Development of nonpancreatic neoplasms was related to age but not to gender, family history, adjuvant chemotherapy, or IPMT pathology. The incidences of nonpancreatic neoplasms and malignancies were significantly higher in patients with IPMT than in those with pancreatic ductal adenocarcinoma (11% and 7%, respectively).

CONCLUSIONS

IPMT is associated with a high incidence of nonpancreatic neoplasms, particularly colorectal neoplasms. In IPMT patients, systemic surveillance may allow early detection of second tumors. In preoperative screening and postoperative follow-up of patients with nonpancreatic neoplasms, the possibility of IPMT should be considered.

Adiponectin suppresses colorectal carcinogenesis under the high-fat diet condition

BACKGROUND AND AIMS

The effect of adiponectin on colorectal carcinogenesis has been proposed but not fully investigated. We investigated the effect of adiponectin deficiency on the development of colorectal cancer.

METHODS

We generated three types of gene-deficient mice (adiponectin-deficient, adiponectin receptor 1-deficient, and adiponectin receptor 2-deficient) and investigated chemical-induced colon polyp formation and cell proliferation in colon epithelium. Western blot analysis was performed to elucidate the mechanism which affected colorectal carcinogenesis by adiponectin deficiency.

RESULTS

The numbers of colon polyps were significantly increased in adiponectin-deficient mice compared with wild-type mice fed a high-fat diet. However, no difference was observed between wild-type and adiponectin-deficient mice fed a basal diet. A significant increase in cell proliferative activity was also observed in the colonic epithelium of the adiponectin-deficient mice when compared with wild-type mice fed a high-fat diet; however, no difference was observed between wild-type and adiponectin-deficient mice fed a basal diet. Similarly, an increase in epithelial cell proliferation was observed in adiponectin receptor 1-deficient mice, but not in adiponectin receptor 2-deficient mice. Western blot analysis revealed activation of mammalian target of rapamycin, p70 S6 kinase, S6 protein and inactivation of AMP-activated protein kinase in the colon epithelium of adiponectin-deficient mice fed with high-fat diet.

CONCLUSIONS

Adiponectin suppresses colonic epithelial proliferation via inhibition of the mammalian target of the rapamycin pathway under a high-fat diet, but not under a basal diet. These studies indicate a novel mechanism of suppression of colorectal carcinogenesis induced by a Western-style high-fat diet.

Application of a reverse transcription-PCR for identification and differentiation of Aichi virus, a new member of the Picornavirus family associated with gastroenteritis in humans

Aichi viruses isolated in Vero cells from seven patients in five gastroenteritis outbreaks in Japan, five Japanese returning from Southeast Asian countries, and five local children in Pakistan with gastroenteritis were examined for differentiation based on their reactivities with a monoclonal antibody to a standard strain (A846/88) and a reverse transcription-PCR (RT-PCR) of three genomic regions. The RNA sequences were determined for 519 bases of these 17 isolates at the putative junction between the C terminus of 3C and the N terminus of 3D. The analyses revealed an approximately 90% homology between these isolates, which were then divided into two groups: group 1 (genotype A) included six isolates from four outbreaks and one isolate from a traveler and group 2 (genotype B) included one isolate from the other outbreak, four isolates from returning travelers, and all of the isolates from the Pakistani children. Based on the isolate sequences, a primer pair and a biotin-labeled probe were designed for amplification and detection of 223 bases at the 3C-3D junction of Aichi virus RNA in fecal specimens. The Aichi virus RNA was detected in 54 (55%) of 99 fecal specimens from the patients in 12 (32%) of 37 outbreaks of gastroenteritis in Japan. Of the 12 outbreaks, 11 were suspected to be due to genotype A. These results indicated that RT-PCR can be a useful tool to detect Aichi virus in stool samples and that a sequence analysis of PCR products can be employed to identify the prevalent strain in each incident.

Glycemic index of single and mixed meal foods among common Japanese foods with white rice as a reference food

OBJECTIVE

The objectives were to examine the feasibility of using white rice as a reference food in the study of glycemic index (GI) and to examine the GI values of both single and mixed meal foods among rice species, processed rice products, beans, and dairy products.

DESIGN

Subjects were served with 50 g carbohydrate content of white rice at least two times (maximum three times) and test food once after separate overnight fasts. Capillary blood glucose measurements were carried out before and during 120 min after each food load.

SETTING

The study was carried out in an outpatient setting.

SUBJECTS

A total of 58 (38 females and 20 males) nondiseased subjects, mean aged 37 y and mean BMI 22 kg/m(2) were included.

RESULT

The correlation between incremental area under curve of white rice and glucose was r=0.853 (n=10, P <0.0001) and white rice was considered suitable to be used as a reference food. Among mixed meal foods, the combination of carbohydrate foods with vinegar, dairy products, and bean products significantly decreased the GI value of white rice of 20-40%. The reduction of GI occurred whether the foods were taken together, before or after rice intake. GI of noodles such as udon, soba, and spaghetti showed low GI values.

CONCLUSION

White rice could be used as a reference food in determining GI values of foods. A total of 32 single and mixed meal Japanese common food products were examined for their GI values.

Role of physiological antioxidants in chromium(VI)-induced cellular injury

Chromium(VI) compounds are well known to be potent toxic and carcinogenic agents. Because chromium(VI) is easily taken up by cells and is subsequently reduced to the trivalent form, the formation of chromium(III) or other intermediate oxidation states such as chromium(V) and (IV) is believed to play a role in the adverse biological effects of chromium(VI) compounds. Recent in vitro studies have shown that this reduction process generates free radical species such as active oxygen radicals. Furthermore, physiological antioxidants are reported to modify the genotoxic and toxic effects of chromate. This article reviewed the recent in vitro and in vivo studies of the effects of antioxidants including active oxygen scavengers; glutathione; vitamins B2, E, and C, on chromate-induced injury such as DNA lesions; lipid peroxidation; enzyme inhibition; cytotoxicity; mutation; and so on. In addition, the mechanism of action of these antioxidants was discussed with respect to the formation of active oxygen radicals and paramagnetic chromium such as chromium(V) and (III). Such studies may help elucidate the mechanism of chromium(VI) toxicity as well as the mechanism of protection.

Integrin expression in normal, hyperplastic, dysplastic, and malignant oral epithelium

We have examined the distribution of a range of integrin subunits in normal and lesional oral mucosa. The alpha 2, alpha 3, alpha 6, beta 1, and beta 4 subunits were highly expressed in normal epithelium, and there was weaker, more variable expression of alpha 5 and alpha v. Expression of all subunits was highest in the basal layer of normal epithelium, but extensive staining above the basal layer was also observed, particularly in the floor of the mouth and the lateral margin of the tongue. In dysplastic lesions and hyperplastic epithelium adjacent to ulcers, suprabasal staining was even more pronounced. Staining patterns in squamous cell carcinomas showed considerable variation, both within and between individual tumours: in some areas there was staining reminiscent of normal epithelium, but uniform staining throughout tumour islands, and patchy and variable cytoplasmic and pericellular staining were also seen. Thirteen out of 17 carcinomas showed some loss of integrin expression: six out of ten moderately well differentiated tumours and all the poorly differentiated tumours. Focal loss of alpha 6 and beta 4 was most commonly observed, but loss of alpha 2 and alpha 3 also occurred. Since integrins regulate not only keratinocyte adhesion, but also the initiation of terminal differentiation, the changes in integrin expression that we have observed may have significance for the behaviour of individual tumours.

Cloning and characterization of a gene (UVR3) required for photorepair of 6-4 photoproducts in Arabidopsis thaliana

UV radiation induces two major classes of pyrimidine dimers: the pyrimidine [6-4] pyrimidone photoproduct (6-4 product) and the cyclobutane pyrimidine dimer (CPD). Many organisms produce enzymes, termed photolyases, that specifically bind to these damage products and split them via a UV-A/blue light-dependent mechanism, thereby reversing the damage. These photolyases are specific for either CPDs or 6-4 products. A gene that expresses a protein with 6-4 photolyase activity in vitro was recently cloned from Drosophila melanogaster and Xenopus laevis. We report here the isolation of a homolog of this gene, cloned on the basis of sequence similarity, from the higher plant Arabidopsis thaliana. This cloned gene produces a protein with 6-4 photolyase activity when expressed in Escherichia coli. We also find that a previously described mutant of Arabidopsis (uvr3) that is defective in photoreactivation of 6-4 products carries a nonsense mutation in this 6-4 photolyase homolog. We have therefore termed this gene UVR3. Although homologs of this gene have previously been shown to produce a functional 6-4 photolyase when expressed in heterologous systems, this is the first demonstration of a requirement for this gene for photoreactivation of 6-4 products in vivo.

A series of novel mutants of Arabidopsis thaliana that are defective in the formation of continuous vascular network: calling the auxin signal flow canalization hypothesis into question

For the genetic analysis of molecular mechanisms underlying temporal and spatial regulation of vascular pattern formation, we isolated mutants of Arabidopsis thaliana that are impaired in vascular patterning. Microscopic examination of the cotyledonary venation of 3,400 M(3) lines led to the identification of 12 mutant lines. Genetic analysis of 8 of these mutant lines indicated that vein pattern formation in these lines resulted from monogenic recessive mutations in 7 different genes, designated VAN1 through VAN7. Mutations in VAN1 through VAN6 genes caused fragmentation (disconnection or partial loss) of lateral veins of the cotyledon and tertiary veins of the rosette leaf whereas they were less injurious to the formation of major veins. Detailed characterization of the van3 mutant using pAthb8::GUS and pTED3::GUS, as molecular markers for the early stage of vascular tissue formation showed that the provascular tissue of the cotyledonary lateral veins was differentiated in fragments during late embryogenesis. These phenotypes of the van mutants are discussed in relation to the auxin signal flow canalization hypothesis and the diffusion-reaction prepattern hypothesis, with the fragility of the continuity in the minor vein formation favoring the latter hypothesis.

Two types of mucin-producing cystic tumors of the pancreas: diagnosis and treatment

BACKGROUND

This study focuses on clinicopathologic, imaging, and prognostic differences between two types of mucin-producing cystic tumors of the pancreas, with the aim of appropriate management of these tumors.

METHODS

Forty-six patients with mucin-producing cystic tumors underwent operation. The types of tumors were as follows: mucinous cystic neoplasm, adenoma (6) and adenocarcinoma (12); intraductal papillary tumor, adenoma (10) and adenocarcinoma (18).

RESULTS

Gender, age, symptoms, signs, tumor location and size, and the presence or absence of communication with the pancreatic duct differed between the two types. Mucinous cystadenocarcinomas showed deep invasion more often than intraductal papillary adenocarcinomas. Lymph node involvement was seen in 58% of mucinous cystadenocarcinomas but in only 22% of intraductal papillary adenocarcinomas. Tumors with mural nodules tended to show deep invasion and nodal metastasis. All four intraductal papillary tumors smaller than 3 cm without mural nodules were adenomas. Imaging studies allowed accurate differentiation between the two types but not between adenomas and adenocarcinomas. Five-year survival rates for patients with adenomas, mucinous cystadenocarcinomas, and intraductal papillary adenocarcinomas were 100%, 33%, and 81%, respectively.

CONCLUSIONS

Mucinous cystic neoplasm necessitates complete tumor excision with wide dissection of lymph nodes including paraaortic nodes. Intraductal papillary tumor requires only peripancreatic node dissection; for tumors smaller than 3 cm without mural nodules, node dissection may be unnecessary.

Is percutaneous cholecystostomy the optimal treatment for acute cholecystitis in the very elderly?

In elderly patients emergent cholecystectomy for acute cholecystitis is a high risk procedure. We prospectively assessed the value of percutaneous cholecystostomy for acute cholecystitis in 38 consecutive elderly (> or = 80 years) patients. All 38 underwent percutaneous transhepatic cholecystostomy under ultrasonographic and fluoroscopic guidance for acute cholecystitis (25 calculous, 13 acalculous). Eight (21%) patients had acute severe medical problems, such as shock and respiratory distress. Thirty-one (82%) patients had chronic severe underlying diseases, including cardiovascular and neurologic diseases. Cholecystostomy was successful in all 38 patients. Prompt clinical improvement was obtained in 36 (95%) patients. Morbidity and mortality rates were 3% and 3%, respectively. After cholecystostomy, 10 patients with cholelithiasis underwent elective cholecystectomy without serious complications. Two patients underwent percutaneous cholecystolithotomy, which produced complete resolution of symptoms. Four of 12 patients with and none of 12 without cholelithiasis had recurrent cholecystitis after catheter removal during a mean follow-up of 1.8 years. A second cholecystostomy was successful in these four patients. Elderly patients are often poor surgical candidates because of severe cholecystitis or concomitant medical problems. Percutaneous cholecystostomy is a safe, effective treatment for acute cholecystitis even in elderly patients. For calculous cholecystitis, cholecystostomy can be followed by elective surgery, if possible, or by nonsurgical treatment or expectant conservative management in high-risk patients. Cholecystostomy may be a definitive treatment for acalculous cholecystitis.

Hepatocellular carcinoma: treatment with percutaneous ethanol injection and transcatheter arterial embolization

The therapeutic effectiveness of a new combination therapy--pretreatment with transcatheter arterial embolization (TAE) and subsequent percutaneous ethanol injection (PEI)--for solitary large (> 3.0 cm in diameter) primary hepatocellular carcinoma lesions was compared with that of TAE alone. With TAE alone, a partial response of the tumor was seen in only 10% of the patients, and the 1-, 2-, and 3-year survival rates were calculated to be 68%, 37%, and 0%, respectively. Histologic examination of specimens obtained at hepatectomy showed that TAE alone caused complete necrosis in only 20% of the tumors. In contrast, PEI combined with TAE significantly (P < .05) increased the partial response rate (45%) and significantly (P < .01) prolonged the 1-, 2-, and 3-year survival rates (100%, 85%, and 85%, respectively). Combination therapy caused complete histologic necrosis in 83% of the tumors. It also was significantly (P < .05) better than TAE alone in terms of rate of primary tumor recurrence during follow-up.

Anti-inflammatory/anti-amyloidogenic effects of plasmalogens in lipopolysaccharide-induced neuroinflammation in adult mice

BACKGROUND

Neuroinflammation involves the activation of glial cells in neurodegenerative diseases such as Alzheimer's disease (AD). Plasmalogens (Pls) are glycerophospholipids constituting cellular membranes and play significant roles in membrane fluidity and cellular processes such as vesicular fusion and signal transduction.

METHODS

In this study the preventive effects of Pls on systemic lipopolysaccharide (LPS)-induced neuroinflammation were investigated using immunohistochemistry, real-time PCR methods and analysis of brain glycerophospholipid levels in adult mice.

RESULTS

Intraperitoneal (i.p.) injections of LPS (250 μg/kg) for seven days resulted in increases in the number of Iba-1-positive microglia and glial fibrillary acidic protein (GFAP)-positive astrocytes in the prefrontal cortex (PFC) and hippocampus accompanied by the enhanced expression of IL-1β and TNF-α mRNAs. In addition, β-amyloid (Aβ3-16)-positive neurons appeared in the PFC and hippocampus of LPS-injected animals. The co-administration of Pls (i.p., 20 mg/kg) after daily LPS injections significantly attenuated both the activation of glial cells and the accumulation of Aβ proteins. Finally, the amount of Pls in the PFC and hippocampus decreased following the LPS injections and this reduction was suppressed by co-treatment with Pls.

CONCLUSIONS

These findings suggest that Pls have anti-neuroinflammatory and anti-amyloidogenic effects, thereby indicating the preventive or therapeutic application of Pls against AD.

Prognosis for canine malignant mammary tumors based on TNM and histologic classification

The 2-year prognosis of malignant mammary tumors seen in 175 bitches in the Tokyo metropolitan area was assessed based on their TNM clinical staging and histological classification. The larger the tumor size became (T category), the poorer was the clinical prognosis. The 2-year survival rates of the animals with regional lymph node metastasis of tumor cells (N1, N2 category) and/or distant metastasis (M1 category) were markedly lower than those of the animals without such involvement. As the grade of TNM staging increased, the prognosis was poorer, however, there were no significant differences in survival rates among subtypes of adenocarcinomas (tubular, papillary and papillary cystic) determined by WHO histological classification. It was also noticed that animals having carcinomas without tubular formation or myoepithelial cell proliferation had a lower survival rate than animals having carcinomas with those characteristics; and invasive carcinomas into adjacent skin or lymphatic/vascular vessels implied a poorer prognosis than non-invasive ones. The results suggest that a combined practice of TNM system and our evaluation on the above-mentioned 4 histologic features could be useful for prognostic determination of canine mammary cancers.

Matrilysin (MMP-7) as a significant determinant of malignant potential of early invasive colorectal carcinomas

Matrix metalloproteinases play a crucial role in tumour invasion and mestasis. Matrilysin (MMP-7) has been shown to correlate with nodal or distant metastasis in colorectal carcinomas; however, its implication in early invasive colorectal carcinomas has not been determined. This study was undertaken to clarify the association of matrilysin expression with clinicopathologic parameters in early invasive colorectal carcinomas. 38 early invasive colorectal carcinomas treated by local excision or radical surgery were examined. Tumour budding was evaluated as the number of dedifferentiation units along the entire invasive margin. Matrilysin protein levels were determined using immunohistochemical study. Univariate analysis showed that matrilysin expression alone was significantly associated with distant metastasis (P= 0.0339), and both tumour budding and matrilysin expression were significantly associated with adverse outcome (P= 0.0005, 0.0341). Histological differentiation, vessel invasion, and depth of invasion were not significantly associated with either distant metastasis or adverse outcome. Multivariate analysis confirmed that tumour budding and matrilysin expression were independently associated with adverse outcome, although the significance of matrilysin expression was marginal (P= 0.0488). Tumour budding at the invasive margin and matrilysin expression are more useful in identifying high-risk groups for adverse outcome in patients with early invasive colorectal carcinomas. © 2001 Cancer Research Campaign www.bjcancer.com

Rescue of rabies virus from cloned cDNA and identification of the pathogenicity-related gene: glycoprotein gene is associated with virulence for adult mice

In order to identify the viral gene related to the pathogenicity of rabies virus, we tried to establish a reverse genetics system of the attenuated RC-HL strain, which causes nonlethal infection in adult mice after intracerebral inoculation. A full-length genome plasmid encoding the complete antigenomic cDNA of the RC-HL strain and helper plasmids containing cDNAs of the complete open reading frame of the N, P, and L genes, respectively, were constructed. After transfection of these plasmids into BHK-21 cells infected with the T7 RNA polymerase-expressing vaccinia virus, infectious rabies virus with almost the same biological properties as those of the wild-type RC-HL strain was rescued. Using this reverse genetics system of the RC-HL strain, we generated a chimeric virus with the open reading frame of the glycoprotein gene from the parent Nishigahara strain, which kills adult mice after intracerebral inoculation, in the background of the RC-HL genome. Since the chimeric virus killed adult mice following intracerebral inoculation, it became evident that the open reading frame of the glycoprotein gene is related to the pathogenicity of the Nishigahara strain for adult mice.

Potent protective effect of melatonin on chromium(VI)-induced DNA single-strand breaks, cytotoxicity, and lipid peroxidation in primary cultures of rat hepatocytes

Incubation of primary cultures of rat hepatocytes with K2Cr2O7 plus the pineal hormone melatonin resulted in a marked decrease in cellular levels of DNA single-strand breaks caused by K2Cr2O7. Cellular treatment with melatonin also suppressed both dichromate-induced cytotoxicity, as evaluated by the leakage of lactate dehydrogenase, and lipid peroxidation, as monitored by malondialdehyde formation. In addition, treatment with melatonin attenuated the suppression of the levels of vitamins E and C as well as the inhibition of catalase activity attributed to K2Cr2O7. However, melatonin had no influence on cellular level of glutathione and the activity of glutathione reductase, glutathione peroxidase, superoxide dismutase, and alkaline phosphatase suppressed by dichromate. Under the same experimental conditions, cellular uptake and distribution of Cr were not affected by melatonin. Electron spin resonance (ESR) studies showed that melatonin did not affect the formation of Cr(V) complexes in the reaction of K2Cr2O7 with reduced glutathione; however, melatonin caused a 25% decrease in the levels of Cr(V)-related hydroxyl radicals in vitro. These results indicate that melatonin protects cells from Cr(VI)-induced DNA strand breaks, cytotoxicity, and lipid peroxidation, possibly through its ability to increase cellular levels of vitamins E and C as well as catalase activity and/or to directly scavenge toxic hydroxyl radicals in cells.

Hepatocellular carcinoma: treatment with a combination therapy of transcatheter arterial embolization and percutaneous ethanol injection

In an attempt to obtain complete tumor necrosis in large hepatocellular carcinoma (HCC) lesions, the authors studied the clinical and histologic findings of a new combination therapy, percutaneous ethanol injection (PEI) with transcatheter arterial embolization (TAE) (pretreatment with TAE and subsequent PEI) in 15 patients with a single, large (3.0-9.0 cm in diameter), encapsulated lesion of HCC. Two weeks after TAE, PEI was performed under ultrasound guidance. A total of four to 11 injections were administered at a rate of one injection twice a week. During the follow-up period (range, 7-23 months), all lesions were reduced in size and no evidence of HCC was present at contrast material-enhanced computed tomography or angiography in nine of 11 patients who did not subsequently undergo surgery. Six patients had a follow-up of 1 year or more, for a 1-year survival rate of 100%. Four patients subsequently underwent surgical resection; complete necrosis of the tumor was observed in all four. The authors conclude that a combination of PEI and TAE is an appropriate treatment for patients with large, encapsulated HCC lesions who are poor surgical risks.