Gelatinase A (type-IV collagenase; M(r) 72,000) is produced by tumour stroma cells and is believed to be crucial for their invasion and metastasis, acting by degrading extracellular matrix macro-molecules such as type IV collagen. An inactive precursor of gelatinase A (pro-gelatinase A) is secreted and activated in invasive tumour tissue as a result of proteolysis which is mediated by a fraction of tumour cell membrane that is sensitive to metalloproteinase inhibitors. Here we report the cloning of the complementary DNA encoding a new matrix metalloproteinase with a potential transmembrane domain. Expression of the gene product on the cell surface induces specific activation of pro-gelatinase A in vitro and enhances cellular invasion of the reconstituted basement membrane. Tumour cells of invasive lung carcinomas, which contain activated forms of gelatinase A, were found to express the transcript and the gene product. The new metalloproteinase may thus trigger invasion by tumour cells by activating pro-gelatinase A on the tumour cell surface.

Forty patients with squamous cell carcinoma of the oral cavity were treated with bleomycin prior to undergoing surgery. The degree of the clinical effect of bleomycin and the postoperative clinical course of each case were estimated from the viewpoint of correlation with the mode of invasion. A strong correlation was found among the mode of invasion, bleomycin sensitivity, and clinical course. A slight effect of bleomycin and poor prognosis existed in the group with a diffuse invasion of mode of invasion, while the greatest effect of bleomycin and good clinical course were achieved in the group with a welldefined tumor‐host borderline.

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Objective. The aim of this study is to obtain helpful information for an effective antimicrobial therapy against orofacial odontogenic infections; such information would be obtained from recent bacteriologic features and antimicrobial susceptibility data.Study design. The bacteriology and antimicrobial susceptibility of major pathogens in 163 patients with orofacial odontogenic infections to seven antibiotics was examined.Results. Mixed infection of strict anaerobes with facultative anaerobes (especially viridans streptococci) was observed most often in dentoalveolar infections, periodontitis, and pericoronitis. Penicillin (penicillin G) was effective against almost all pathogens, although it did not work well against ß-lactamase-positive Prevotella. Cefmetazole was effective against all test pathogens. Erythromycin was ineffective against viridans streptococci and most Fusobacterium. Clindamycin exerted a strong antimicrobial activity on anaerobes. Minocycline was effective against almost all of the test pathogens. The antimicrobial activity of levofloxacin against viridans streptococci was not strong.Conclusions. An antibiotic that possesses antimicrobial activity against both viridans streptococci and oral anaerobes should be suitable for treatment of dentoalveolar infection, periodontitis, and pericoronitis. Penicillin remains effective as an antimicrobial against most major pathogens in orofacial odontogenic infections.Cefmetazole, clindamycin, and minocycline may be effective against most pathogens, including penicillin-unsusceptible bacteria. 2Although numerous patients suffer from orofacial odontogenic infections, many of these infections can be managed without the use of antibiotics, e.g., by tooth extraction, endodontic therapy, and surgical treatment, including drainage. However, when an acute bacterial infection has progressed or antimicrobial therapy might be of benefit to patients, antibiotics are prescribed. [1][2][3][4][5][6] When antibiotics are prescribed for the treatment of orofacial odontogenic infections, clinicians should choose them on a case-specific basis, and the choice should be based on several factors, e.g., laboratory data, patient's health, age, allergies, drug absorption and distribution ability, and plasma levels. [1][2][3][4][5][6] Penetration and metabolism of the drug, type or location of the infection, previous use of antibiotics, and cost are other factors to be considered. [1][2][3][4][5][6] The laboratory data regarding bacteriology and antimicrobial susceptibility is crucial information for the clinician considering the administration of the antimicrobial therapy. 3,6,[7][8][9] However, it may take several days or even longer to obtain such data. Hence, antibiotics may be chosen empirically. ß-Lactam antibiotics, especially penicillins, have traditionally been recommended as a first-line antibiotic because they work well against most causative bacteria and because penicillins have a low incidence of side effects. [1][2][3][4][5][6] Furthermore, such medicines are relativ...

For patients with ACS caused by plaque erosion, conservative treatment with anti-thrombotic therapy without stenting may be an option.

The relationship between the mode of tumor invasion in the tumor-host borderline and the frequency of regional lymph node metastasis was investigated in squamous cell carcinoma of the oral cavity. Cases with grades 1-3 mode of invasion classified by modified Jacobsson criteria showed a low frequency of metastasis (10/72, 13.9%), while those cases with grade 4 mode of invasion, which consisted of grade 4C (cord-like type) and grade 4D (diffuse type) showed a high frequency of metastasis (4C:11/18,61.1%; 4D :9/12,75.0%; total 20/30,66.7%). Moreover, the number of metastatic nodes in each case of mode of invasion ranged from 1 to 3 in grades 1-3, from 1 to 5 in grade 4C, and from 1 to 7 in grade 4D . The presence of metastasis indicated a poorer prognosis than did the absence of the mode of invasion in each grade, especially in grades 4C and 4D .

A historical cohort study was conducted to investigate the long-term effect of exposure to ingested arsenic. The 454 residents who had been identified in a list made in 1959 were followed until 1992. They lived in an arsenic-polluted area, called Namiki-cho, Nakajo-machi, in Niigata Prefecture, Japan, and used well water containing inorganic arsenic. The exposure period was estimated to be about 5 years (1955-1959). Death certificates for the people who died between 1959 and 1992 were examined, and a total of 113 of the 454 residents were estimated to have drunk well water containing a high dose of arsenic (> or = 1 ppm). The standardized mortality rate ratios of these 113 residents were 15.69 for lung cancer (observed/expected = 8/0.51; 95% confidence interval (CI) 7.38-31.02) and 31.18 for urinary tract cancer (observed/expected = 3/0.10; 95% CI 8.62-91.75). Cox's proportional hazard analyses demonstrated that the hazard ratios of the highest exposure level group (> or = 1 ppm) versus the background exposure level group (0.001 ppm) were 1.74 (95% CI 1.10-2.74) for all deaths and 4.82 (95% CI 2.09-11.14) for all cancers. The analysis according to the skin signs of chronic arsenicism in 1959 showed that they were useful risk indicators for subsequent cancer development. In the development of lung cancer, there was evidence of synergism between arsenic intake and smoking habit.

Fibrous stroma in SCC appeared to have a desmoplastic response. However, an independent invasive mechanism may regulate the stroma, with tumor desmoplasia occurring in highly developed, invasive tumors.