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Oral amelanotic melanomas are rare and the prognosis is poorer than that of pigmented melanomas because of delays in establishing the correct diagnosis and in the initiation of treatment. Amelanotic forms are also thought to be biologically more aggressive than pigmented melanomas. We have seen three cases of oral amelanotic melanomas since 1970, in two of whom the diagnosis was long delayed. Two lesions were not pigmented but one had slight pigmentation. One patient simultaneously had both an amelanotic and a pigmented melanoma in the oral cavity. Lymph node metastases and distant metas tases developed in all patients, two of whom eventually died of the disease. Early diagnosis by histological examination together with immunostaining with S100 and HMB-45 are the keys to improve survival for patients with amelanotic melanoma.

A complication of lower thoracic oesophagectomy for oesophageal carcinoma is reported. Extrapericardial tamponade was caused by a dilated retrosternal gastric roll. Echocardiography was useful for diagnosis. Diagnosis, investigation and management of this unusual but life-threatening complication are discussed. Transthoracic echocardiography is a useful and practical investigation for the evaluation of complications of oesophagectomy.

Hepatocyte growth factor (HGF) is thought to play a role in cell motility and invasion. Matrix metalloproteinases (MMPs) have been implicated in invasion and metastasis of tumor cells. We have previously reported that the Ets-oncogene family transcription factor E1AF positively regulates transcription of MMP genes in transient expression assays and that overexpression of the E1AF gene confers an invasive phenotype on breast cancer cells. Here we examined the effect of HGF on E1AF and MMP gene expression in terms of the invasive potential of the oral squamous cell carcinoma cell line HSC3. HGF stimulated expression of the E1AF gene. The levels of MMP-1, -3 and -9 mRNAs increased in cells treated with HGF and correlated with E1AF upregulation. In contrast, no obvious upregulation of MMP-1 and -9 mRNA was observed in ASE1AFHSC3 cells transfected with the antisense E1AF expression vector into parental HSC3 cells. The wild-type MMP-9 gene promoter was activated by endogenous E1AF in HSC3 cells, and chloramphenicol acetyltransferase (CAT) activities increased when HGF was added to transfected cells. On the other hand, CAT activity was reduced to almost two-thirds of the wild-type activity when HSC3 cells were transfected with a CAT reporter plasmid driven by a mutant MMP-9 promoter lacking the Ets-binding site, and induction of CAT activity was not observed upon addition of HGF. Analysis of organotypic raft cultures revealed that HSC3 cells invaded and degraded collagen gel actively upon addition of HGF. These results suggest that HGF induces expression of the Ets-related E1AF transcription factor gene whose product in turn activates MMP genes and leads to oral cancer cell invasion.

This study compares the effects of disocclusion and overloading occlusion on dental lesions. Ten-day-old Syrian hamsters were divided into 4 groups: group I, untreated animals; group II, animals whose hemilateral incisors were disoccluded; group III, N-methylnitrosourea (MNU)-treated animals; and group IV, MNU-treated animals whose hemilateral incisors were disoccluded. The ipsilateral maxillary and mandibular incisors were repetitively cut with diamond discs. The hamster is easier to anesthetize. Animals received a 0.2% solution of MNU (10 mg/kg body weight) intragastrically twice a week for 16 wk. All the cut mandibular incisors and the MNU-treated uncut mandibular incisors showed lack of iron deposition on the enamel surface. The eruption rate was significantly higher in the cut disoccluded incisors of groups II and IV (p < 0.05) and significantly lower in the uncut overloaded incisors of groups II and IV (p < 0.05). In the cut mandibular incisors of group IV, the degree of the disturbance of odontogenesis and the atypical proliferation of odontogenic epithelium were more prominent (p < 0.02), and the dental lesions occurred earlier. Histologically, the disturbed Hertwig's epithelial sheath and the Hertwig's epithelial sheath-like transformed U-shaped part and enamel organ seemed to lead to disturbances of amelogenesis and detinogenesis as well as to atypical proliferation of odontogenic epithelium nests. Thus, this method of disocclusion of the incisors of rodents may represent a useful model for the investigation of the effects of various agents on tooth formation over a short experimental period.

OBJECTIVE: This study was undertaken in order to investigate clinicopathologic characteristics and malignant potential of widespread multiple oral leukoplakias.

Study objective: To assess the treatment and outcome of patients with crush syndrome sustained in an earthquake disaster. Methods: We conducted a retrospective analysis of eight patients with crush syndrome and subsequent acute kidney failure who were treated in the ICU of a university hospital. All eight patients had been extricated from buildings that collapsed in the 1995 Kobe, Japan, earthquake. Crush injury involved the upper extremities in one patient and the lower extremities in seven. Each patient received intravenous fluid infusion and diuretic drugs and underwent hemodialysis. Emergency fasciotomy was performed in some patients, 17 to 100 hours after extrication. Results: All patients were conscious and lucid on admission, and blood pressure and heart rate were normal. All the patients demonstrated kidney failure with increased concentrations of serum creatinine (1.9 to 9.6 mg/dL [169 to 852 @mmol/L]). Six patients were oliguric. Hyperkalemia (5.6 to 8.8 mEq/L) was present in six patients. We found close correlations between the serum potassium and creatine kinase concentrations, between the serum myoglobin and potassium concentrations, and between the serum myoglobin and creatine kinase concentrations. All the patients were weaned from hemodialysis. The serum creatinine concentration decreased to a normal level within 20 to 52 days of admission in all patients. No patients underwent amputation. Muscle weakness and sensory deficits persisted in all patients 6 months after the earthquake. Conclusion: Our findings support current therapeutic strategies for crush syndrome, despite the long delay to initiation of intensive therapy. All the patients recovered kidney function and were weaned from hemodialysis; none required amputation. [Oda Y, Shindoh M, Yukioka H, Nishi S, Fujimori M, Asada A: Crush syndrome sustained in the 1995 Kobe, Japan, earthquake: Treatment and outcome. Ann Emerg Med October 1997;30:507-512.]

Flow cytometric analysis of cell cycle fractions and DNA ploidy was performed on 39 biopsy specimens of oral leukoplakia. The aneuploidy rate of these leukoplakias was 9/39 (23.1%) and the mean DNA index of the aneuploid lesions was 1.34. The aneuploidy rate was significantly higher in severely dysplastic lesions (8/17) than in mildly dysplastic (1/15, P<0.02) and nondysplastic (0/7, P<0.05) lesions. No significant differences in the percentages of each cell cycle fraction were seen between the diploid and the aneuploid leukoplakias. However, the S-phase fraction of the severely dysplastic lesions (23.0%) among the diploid leukoplakias was higher than those of the midly dysplastic (12.4%) and nondysplastic (15.5%) lesions, and the difference between the severely dysplastic and the mildly dysplastic lesions was statistically significant (P<0.001). These results suggest that flow cytometric analysis of cell cycle fractions and DNA ploidy might offer additional information for assessing the malignant potential of oral leukoplakias.

To provide an accurate evaluation of the association of human papillomavirus (HPV) with lung cancer, 36 cases of lung cancer were analysed for HPV DNAs by polymerase chain reaction (PCR) with dot-blot and Southern blot analyses, and for the transcripts from the E6-E7 transforming region by in situ hybridisation (ISH). HPV-18 DNA was detected in three (8%) of 36 specimens; histologically, in one (10%) of 10 squamous cell carcinomas and two (9%) of 22 adenocarcinomas. Neither HPV-16 nor -33 DNA was detected in any cases examined. Expression of E6-E7 mRNA was confirmed in the cases which contained, HPV-18 DNA. HPV-18 may play an important role in the development and progression of cancer in some cases of both squamous cell carcinoma and adenocarcinoma of the lung.