Telomerase activation and cell proliferation during 7,12-dimethylbenz[a]anthracene-induced hamster cheek pouch carcinogenesis

Telomerase is a ribonucleoprotein complex intimately involved in cell immortalization and carcinogenesis. This enzyme is activated and stabilizes telomere length in almost all types of cancer. Telomerase may be necessary for continuous cell proliferation. In this study, we analyzed telomerase activity in hamster experimental oral lesions (starting from epithelial hyperplasia through dysplasia, carcinoma in situ, and invasive carcinoma) evoked by 7,12-dimethylbenz[a]anthracene, and in normal mucosa. We also analyzed proliferative activity in these lesions by using immunohistochemical analysis and flow cytometry. Histologically normal epithelium expressed weak telomerase activity. The telomerase activity count increased rapidly in the early stage of carcinogenesis and gradually in the late stage. Cell-proliferative activity closely correlated with progression of disease. These findings indicate that telomerase activation is an early event and that increases in telomerase activity upregulate cell proliferation in chemically induced hamster oral carcinogenesis.

Intraosseous epithelioid hemangioendothelioma of the mandible: a case report with an immunohistochemical study

Epithelioid hemangioma is the prototype of a group of vascular tumors characterized by epithelioid endothelial cells. Hemangioendothelioma of bone is a rare lesion that constitutes less than 0.5% of primary malignant skeletal tumors. We report and discuss a case of epithelioid hemangioendothelioma arising intraosseously in the anterior portion of the mandible in a 76-year-old woman. The case was treated successfully by wide resection. Radiographically, the tumor mass showed osteolysis and expansion. Histologically, the tumor showed invasive and destructive growth, although it lacked frequent mitotic figures and severe atypia. On immunohistochemical study, tumor cells exhibited characteristics of mesenchymal and endothelial origin, i.e., strong to moderate immune reactivity against vimentin, factor VIII-related antigen (F8RA), Ulex europaeus agglutinin type 1 lectin (UEA-1), and CD 34, but not against keratin, epithelial membrane antigen (EMA) or S-100 protein (S100). The proliferating cell nuclear antigen (PCNA)-positive cell index was 27.5%. These pathological findings suggested a borderline malignant potential for this tumor. Thus, clinically, wide resection with or without dissection of regional lymph nodes is recommended.

Effects of GABA on noradrenaline release and vasoconstriction induced by renal nerve stimulation in isolated perfused rat kidney

We examined effects of gamma-aminobutyric acid (GABA) on vasoconstriction and noradrenaline (NA) release induced by electrical renal nerve stimulation (RNS) in the isolated pump-perfused rat kidney. RNS (1 and 2 Hz for 2.5 min each, 0.5-ms duration, supramaximal voltage) increased renal perfusion pressure (PP) and renal NA efflux. GABA (3, 10 and 100 microM) attenuated the RNS-induced increases in PP by 10-40% (P<0.01) and NA efflux by 10-30% (P<0.01). GABA did not affect exogenous NA (40 and 60 nM)-induced increases in PP. The selective GABA(B) agonist baclofen (3, 10 and 100 microM) also attenuated the RNS-induced increases in PP and NA efflux, whereas the RNS-induced responses were relatively resistant to the selective GABA(A) agonist muscimol (3, 10 and 100 microM). The selective GABA(B) antagonist 2-hydroxysaclofen (50 microM), but not the selective GABA(A) antagonist bicuculline (50 microM), abolished the inhibitory effects of GABA (10 microM) on the RNS-induced responses. The selective alpha2-adrenoceptor antagonist rauwolscine (10 nM) enhanced the RNS-induced responses. GABA (3, 10 and 100 microM) potently attenuated the RNS-induced increases in PP by 40-60% (P<0.01) and NA efflux by 20-50% (P<0.01) in the presence of rauwolscine. Prazosin (10 and 30 nM) suppressed the RNS-induced increases in PP by about 70-80%. Neither rauwolscine (10 nM) nor GABA (10 microM) suppressed the residual prazosin-resistant PP response. These results suggest that GABA suppresses sympathetic neurotransmitter release via presynaptic GABA(B) receptors, and thereby attenuates adrenergically induced vasoconstriction in the rat kidney.

Clinical features of 89 patients with autoimmune hepatitis in Nagasaki Prefecture, Japan

We examined the clinical characteristics of 89 patients with autoimmune hepatitis (AIH) in Nagasaki Prefecture, Japan, and assessed the usefulness of a provisional scoring system for the diagnosis of AIH proposed by the International Autoimmune Hepatitis Group in 1993. The majority of patients were middle-aged women in their fifties. All patients showed a hepatitic picture. Forty-three patients (48%) had an insidious or chronic onset, while 34 (38%) had an acute onset, and 12 (14%) had liver cirrhosis at presentation. Seventy-nine patients (89%) were positive for antinuclear antibody (ANA), and 5 (6%) were positive for antibody to the hepatitis C virus (anti-HCV). The prognosis was good, with 90% 3-year survival, and most patients responded well to treatment with corticosteroids. The international scoring system was useful for the diagnosis of AIH in most of our patients; the percentages of patients with definite and probable AIH were 48% and 47%, respectively. However, certain factors, such as negative ANA, positive antimitochondrial antibody, concurrent infection with hepatitis B or C virus, and insufficient response to treatment precluded the diagnosis of AIH in some patients. Whether these patients were indeed "true" AIH patients is not clear at present, and further investigation of such patients may be useful for a better understanding of AIH.

Species specificity of cytokeratin polypeptide expression in the submandibular gland

Using nine monospecific and seven polyspecific monoclonal antibodies (MoAbs) against cytokeratin (CK), we immunohistochemically studied the species specificity of CK localization in human, rat, mouse, hamster and guinea pig submandibular glands (SMGs). All species showed different staining patterns with various degrees of intensity. The pattern of immunostaining was broadly classified into three groups. Group I showed positive reactivity to the rodent salivary gland, but not to human SMGs (6B10 and 34betaE12). Group 2 showed the reverse staining pattern (M20, A53-B/A2 and Ks19.1). Group 3, for which almost all species were positive, showed interspecific diversity in the staining pattern (CY-90, K8.12, K8.13, C-11 and KH-1). Species specificity of CK should always be taken into consideration when immunohistochemically examining CK expression during development or during carcinogenesis in rodents.

Telomerase components as a diagnostic tool in human oral lesions

Telomerase activity is considered to be a diagnostic marker of malignancy since most malignant cells express this activity and most somatic cells do not. However, the detection of telomerase activity is rather complicated and is affected by many factors. Recently, human telomerase components were cloned and found to consist of 3 subunits. We assessed which component of telomerase best correlates with malignancy in order to study the possibilities for developing a new diagnostic marker. Telomerase activity was measured by a telomeric repeat amplification protocol (TRAP) assay, and the telomerase components hTR, hTRT-mRNA and TP1-mRNA were detected by the reverse transcriptase-polymerase chain reaction (RT-PCR). Twenty-five of 26 oral malignant lesions, 9 of 22 benign lesions and none of 19 normal control tissues exhibited distinct telomerase activity. hTR and TP1-mRNA expression levels were detected in all malignant lesions and normal control tissues and had no significant correlation with the telomerase activity results. In contrast, hTRT-mRNA expression was closely associated with telomerase activity. All lesions expressing hTRT were telomerase positive. In addition, some samples of dysplastic lesions, benign tumors, lichen planus and normal mucosa exhibiting poor telomerase activity revealed weak expression of hTRT. Expression levels of hTRT-mRNA positively correlated with clinical and pathological findings. Detection of hTRT-mRNA by RT-PCR appeared to be more sensitive for telomerase than measurement of telomerase activity by the TRAP assay. Detection of hTRT-mRNA may provide information useful in the diagnosis of oral malignancies.

Extraction of cytokeratin from the human submandibular gland and its electrophoretic analysis

We evaluated a method for extracting cytokeratin (CK) from the normal human submandibular gland and analyzed CK distribution by one- and two-dimensional electrophoresis. Four submandibular glands without histological changes under a light microscope were used as specimens. Intermediate filamentous protein was extracted by a prior modified method CK was not adequately extracted in 1-2% sodium dodecyl sulfate -5% 2-mercaptoethanol solution. On the other hand, 11 bands with molecular weights of 40-58 K were obtained after extraction in 9.5 M urea -5% 2-mercaptoethanol solution. Although fragmentation of cytoskeletal protein was observed, there were no differences in bands according to the strength of homogenization. This fragmentation seemed to be due to restriction degradation by protease. Immunoblotting revealed the reaction of this CK extract to 2 pan-CK antibodies, i.e., K8.13, which recognizes type II basic CK, and C-11, which recognizes CK4, CK5, CK6, CK8, CK10, CK13, CK18. Among monospecific antibodies, anti-CK7 (LDS-68), CK8 (M20), CK13 (KS-1A3), CK18 (CY-90), and CK19 (BA17) antibodies showed positive reactions. Glial fibrillary acidic protein, neurofilament (NF) 68 K, NF160 K, or NF200 K showed no reactions. These results of one- and two-dimensional electrophoretic analysis suggest the presence of CK5, CK7, CK8, CK13, CK14, CK15, CK17, CK18, and CK19 in the normal submandibular gland.

Cytokeratin expression in squamous cell carcinoma of the lung and oral cavity: an immunohistochemical study with possible clinical relevance

OBJECTIVE

Serologic identification of the fragment of cytokeratin 19 known as CYFRA 21-1 has been used for early detection of squamous cell carcinoma of the lung. The sensitivity of the CYFRA 21-1 assay in detecting oral cancers is lower than that in detecting lung cancers. To clarify the reason for this, we compared the cytokeratin expression in these cancers, with special reference to cytokeratin 19.

STUDY DESIGN

Oral squamous cell carcinomas and lung squamous cell carcinomas were immunostained with cytokeratin 19, cytokeratin 10, and cytokeratin 13 antibodies. Staining intensity was scored on a graduated scale from 0 to 4.

RESULTS

With respect to cytokeratin 19, the stainings of all lung cancers were scored as 4, which indicates a greater expression of cytokeratin 19 than is seen in oral cancers (p < 0.01). With an average cytokeratin 19 staining score of 1.67, oral cancers ranked lowest among the antibodies. Squamous cell carcinomas of the maxillary sinus arising from pseudostratified ciliated epithelium were highly expressive of cytokeratin 19. A marker for keratinizing cells (cytokeratin 10) and a marker for squamous cells (cytokeratin 13) were expressed more frequently and intensely in oral cancers (p < 0.01) than in lung cancers (p = 0.019).

CONCLUSIONS

From the viewpoint of immunohistochemistry, cytokeratin 19 was found to be a tumor marker with low specificity and sensitivity in oral cancers. The staining results suggested that poor expression of cytokeratin 19 by oral squamous cell carcinoma may result in a low serum value of CYFRA 21-1 in patients with this condition.

Detection of telomerase activity in oral lesions

Telomerase is a ribonucleoprotein complex intimately associated with cell immortalization and neoplastic transformation. In almost all types of cancer this enzyme is reactivated and stabilizes telomere length. It may be necessary for continuous cell proliferation. In this study we used a non-radioactive polymerase chain reaction assay to analyze telomerase activity in various tissue specimens taken from the oral cavity. Four of 4 (100%) squamous cell carcinoma cell lines, 28 of 29 (96%) malignant tumors, 10 of 28 (36%) benign lesions, and none of the 14 (0%) oral control tissues possessed telomerase activity. Moreover, 4 of 15 (27%) oral rinses and 3 of 3 (100%) samples of ascites and pleural effusion taken from patients with oral malignancy were telomerase positive. These findings indicate that the evaluation of telomerase activity in tissue and body fluid specimens may provide information useful in the diagnosis of oral malignancy.

Beta adrenergic antagonist permeation across cultured rabbit corneal epithelial cells grown on permeable supports

PURPOSE

To determine whether cultured rabbit corneal epithelial cells (RCEC), grown on permeable supports, provide a suitable in vivo model for characterizing transcellular drug permeation and metabolism.

METHODS

Primary rabbit corneal epithelial cells grown in DMEM-F12 were seeded on Transwell-COL inserts coated with fibronectin. The epithelial barrier integrity was evaluated, based on measurements of 14C-mannitol and 3H-PEG900, and their transepithelial electrical resistance (TEER). Ultrastructure evaluation was based on scanning electron microscopy and transmission electron microscopy, which were performed 8 days after seeding. Measurements of beta adrenergic antagonist permeability were performed to assess transcellular permeability.

RESULTS

Eight days after seeding, the TEER reached a peak of 144 omega.cm2 and the 14C-mannitol and 3H-PEG900 permeabilities were 6.8 x 10(-6) and 2.9 x 10(-6) cm/sec, respectively. Ultrastructural analysis revealed a multilayered structure with numerous microplicae and typical cytoplasmic organelles along with desmosomes. The relationship between permeation of beta-blockers and lipophilicity resembled the intact isolated cornea.

CONCLUSIONS

This is the first description of cultured RCEC grown on permeable support. Many of its properties mimic those described in the intact corneal epithelium. Even though its electrical tightness is less than that of the intact cornea, the transcellular permeability to lipophilic beta-antagonists is comparable to the isolated preparation. Therefore, this model will facilitate characterization of ocular permeation mechanisms of hydrophobic drugs whose route of permeation is transcellular.

Histological effects and predictive biomarkers of TPP induction chemotherapy for oral carcinoma

The effects of an induction chemotherapy with THP-adriamycin, cisplatin, and peplomycin (TPP) were studied in 32 patients with operable oral cancer. The histological evaluation according to the Shimozato-Oboshi classification was Grade (G) IV in ten cases (31.3%), GIII in one case, and GIIb in four cases. Induction of apoptosis and differentiation-inducing effects, hyperkeratinization or bone formation, were observed in some cases. The overall clinical response rate and histological response rate were 63% and 47%, respectively. Grade III was obtained in seven metastatic lymph nodes of three patients. The expressions of PCNA, p53, and AgNORs before and after chemotherapy were studied. The prechemotherapeutic PCNA positive cell index (PI) of the highly responsive tumors (GIII, IV) was significantly lower than that of the poorly responsive tumors (G0-IIb) (P < 0.01). Similar results were obtained in the evaluation of p53 PI (P < 0.05), suggesting that PCNA and p53 are useful biomarkers for predicting the efficacy of TPP chemotherapy.

"Chain-link" combined tissue transfer for the reconstruction of the mandible

We describe a procedure for "chain-link" combined tissue transfer connecting the vascular pedicle of a deep circumflex iliac flap with that of a forearm flap after wide resection of the mandible. Combination of these flaps facilitated the reconstruction of the defect in both intra- and extraoral soft tissue and the mandibular bone. This method is useful when cervical recipient blood vessels are limited due to the wide resection of the primary tumor and radical neck dissection.

MR of the endolymphatic duct and sac: findings in Menière disease

PURPOSE

To compare the visibility of the endolymphatic duct and sac on high-resolution MR images with the symptoms and clinical course in patients with Menière disease.

METHODS

Twenty-two patients with unilateral Menière disease were sorted into two groups on the basis of the clinical stage of their disease at the time of imaging. Group 1 included patients in the acute phase, who presented with vertigo. Group 2 comprised patients in the nonacute phase of the disease, who were studied 9 days or more after an episode of vertigo.

RESULTS

During acute attacks, the endolymphatic duct and sac were not adequately visible in the affected ear but were visible in the unaffected ear. During remission, the endolymphatic duct and sac were not observed in clinically advanced patients, but they were seen in patients in the early and intermediate stages.

CONCLUSION

High-resolution MR imaging can be used to evaluate the endolymphatic duct and sac: visible abnormalities and lack of a visible endolymphatic duct and sac correlate with the clinical course of Menière disease.

Detection of human herpesvirus 6 and human herpesvirus 7 in the submandibular gland, parotid gland, and lip salivary gland by PCR

In order to define the major sites of persistence of human herpesvirus 6 (HHV-6) and HHV-7, PCR with DNAs from more than 100 specimens of 3 different salivary glands was performed. HHV-6 DNA was detected in 52 (88.1%) of 59 submandibular gland, 17 (63.0%) of 27 parotid gland, and 9 (52.9%) of 17 lip salivary gland specimens. On the other hand, HHV-7 DNA was detected in 59 (100%) of 59 submandibular gland, 23 (85.2%) of 27 parotid gland, and 10 (58.8%) of 17 lip salivary gland specimens. These findings demonstrate that salivary glands are a site of persistent infection of both HHV-6 and HHV-7 and that among the three types of salivary gland examined, the submandibular gland is the primary one in which these herpesviruses, especially HHV-7, persist.

Clinical manifestations of HBsAg and anti-HCV negative chronic liver disease in Nagasaki Prefecture, Japan

The discovery of hepatitis C virus (HCV) has enabled the diagnosis of type C chronic liver disease, which had in the past been diagnosed as part of non-A, non-B chronic liver disease. Although most cases with chronic liver disease are caused by hepatitis B virus (HBV) or HCV infection, there are still cases of non-B, non-C chronic liver disease. Forty patients with chronic liver disease, who were seronegative for hepatitis B surface antigen and antibody to HCV, were followed for a mean period of 72 months. The clinical manifestations in these patients were compared with those reported for type B and type C chronic liver disease. Of the 40 patients, 22 were diagnosed with chronic hepatitis, 14 with liver cirrhosis and 4 with hepatocellular carcinoma (HCC). Twenty-seven (67.5%) patients showed mild alanine aminotransferase activity profiles, and the natural clinical course of most patients showed a slow progression compared with that reported for type B and type C patients. The yearly incidence of HCC was 9.7% in patients with liver cirrhosis and 3.9% in chronic hepatitis. These rates were similar to those in type B or type C patients. This suggests that our population sample contained a number of patients with type B, type C or other etiologic agent(s), because 66.7% of the patients who developed HCC had some evidence of exposure to HBV or HCV. Our results suggest that more detailed and accurate tests for detecting HBV and HCV should be considered before making the diagnosis of non-B, non-C chronic liver disease, and that there is the need to reveal unknown etiologic agent(s).

Comparison of roxatidine and famotidine on nocturnal gastric juice secretion

Adult patients with symptoms of gastric disease were randomly assigned to two treatment groups (roxatidine group, n = 115; famotidine group, n = 113) or untreated control group (placebo, n = 111). The treatment groups randomly received 75 mg of roxatidine or 20 mg of famotidine at 9 pm, and 12 - 13 h later gastric juice secretion was measured with gastric X-ray films in both groups. Mean gastric juice secretion was significantly lower in the treated groups (roxatidine, 16.1 ml/12 h; famotidine, 19.9 ml/12 h) than in the untreated controls (placebo, 49.5 ml/12 h). Gastric juice suppression by roxatidine and by famotidine, respectively, was 82% and 37% in patients with gastric ulcer; 71% and 39% in patients with duodenal ulcer; 70% and 64% in patients with gastritis; and 68% and 86% in patients with no evidence of disease. It is concluded that roxatidine was more effective than famotidine for gastric juice suppression in patients with peptic ulcer. In patients with no evidence of gastric disease, however, famotidine was more effective than roxatidine.