Associations of remaining teeth number, periodontal disease, and occlusal support status with erectile dysfunction in community-dwelling men.

OBJECTIVES: Several systematic reviews and meta-analyses have reported positive relationships between erectile dysfunction (ED) and periodontal disease. However, no study has evaluated the relationships of occlusal support status and the number of remaining teeth with ED. The aim of the present study was to investigate the relationships between ED and the remaining teeth number, periodontal disease, and occlusal support status. METHODS: This study included 400 community-dwelling men. Periodontal health status and occlusal support condition were evaluated using the Community Periodontal Index (CPI) and Eichner classification. Multivariable analyses were performed to evaluate the relationships between ED and the remaining teeth number, periodontal disease, and occlusal support status. RESULTS: The median age was 53 years. Of the 400 men, 333 (83%) were classified into ED group. In univariable analyses, remaining teeth number, CPI score, and Eichner classification were significantly associated with ED. In multivariable analyses, the remaining teeth number (odds ratio [OR]: 0.907, p = 0.114) and CPI score (OR: 0.978, p = 0.864) were not significantly associated with ED, whereas the Eichner classification was independently and significantly associated with ED (OR: 3.490, p = 0.042). CONCLUSIONS: Poor occlusal support status was significantly associated with ED in community-dwelling men, as opposed to remaining teeth number and periodontal health status.

Oral-maxillofacial trauma of a geriatric population in a super-ageing country.

BACKGROUND/AIM: World population has been ageing, and oral-maxillofacial trauma of geriatric population is expected to increase. The aim of this study was to analyse the characteristic features of oral-maxillofacial trauma in the geriatric population. MATERIALS AND METHODS: Data from 127 patients aged 65 years old or older, who were treated for oral-maxillofacial trauma at the Department of Oral and Maxillofacial Surgery, Hirosaki University, from 2000 to 2014, were retrospectively analysed. The data from 292 patients aged 20-64 years were used as a comparison. RESULTS: Oral-maxillofacial trauma in the geriatric population had been increasing over 15-year period. The male to female ratio was 1.05:1 in the older group and 2.3:1 in the younger group. In the older group, 117 patients (92.1%) had one or more underlying systemic diseases, and 16 (12.6%) had suffered injuries in association with acute medical disorders. The most common injuries in the older group were bone fractures (46.5%). The ratio of fractures in the older group was lower than in the younger group (69.2%). Trauma in the older group most frequently occurred because of falls from a standing height or lower (52.0%), and the mandible was the most common site of fracture (74.6%). A conservative form of treatment for maxillofacial fractures was most commonly (86.4%) chosen for the older group, whilst surgical treatment was most commonly in the younger group (55.0%). CONCLUSION: Oral-maxillofacial trauma in the geriatric population shows characteristic features in terms of aetiology, patterns and treatment modalities.

Impalement of an unusual foreign body on the temporomandibular joint causing severe trismus.

A penetrating injury by a foreign body is comparatively common in the oral and maxillofacial region. On the other hand, injury to the temporomandibular joint (TMJ) by a foreign object is very rare. The TMJ is an anatomically narrow space surrounded by hard bony processes. An unusual case of trauma with severe trismus caused by a foreign body that impaled the TMJ is reported. A 55-year-old man presented with a 5 × 1-cm laceration to the right cheek caused by a flying object propelled during the use of a lawn mower. The edge of the foreign body had a metallic wire, which became imbedded in the wound. His jaw opening was severely limited. Computed tomography revealed that the foreign body was 3 mm in diameter and was impaled on the articular capsule. The object was successfully removed, and the wound and interior of the TMJ were irrigated. Rehabilitation of mouth opening was started on postoperative day 3. On day 9, mouth opening had improved to 35 mm, and he was discharged. After 1 year, mouth opening was 45 mm with no sign of any TMJ disorders.

Association between oral frailty and lower urinary tract symptoms among middle-aged and older adults in community-dwelling individuals: a cross-sectional study.

PURPOSE: We assessed the association between oral frailty risk and LUTS among middle-aged and older adults in a community-dwelling population. METHODS: This cross-sectional study was conducted among 586 subjects aged ≥ 40 years who participated in the Iwaki Health Promotion Project in Hirosaki, Japan. We used the International Prostate Symptom Score (IPSS) and the Overactive Bladder Symptom Score (OABSS) to assess LUTS. LUTS was defined as an IPSS score of 8 or higher or meeting diagnostic criteria for OAB. Oral frailty risk was defined as experiencing two or more of the following: decreased chewing ability, decreased biting force, and dry mouth sensation. Physical performance (10-m gait speed and grip strength) was used for analysis. The association between oral frailty risk and LUTS was examined using multivariate logistic regression analyses. RESULTS: The study included 218 men and 370 women, of whom 140 had LUTS. The mean age of this cohort was 59 years. Significant differences were observed between the LUTS and non-LUTS groups, including age, hypertension, history of CVD, depressive status, sleep disturbance, and 10 m gait speed. The prevalence of oral frailty risk was significantly higher in the LUTS group than in the non-LUTS group (26% vs. 11%, P < 0.001). Multivariate analysis revealed that age, male gender, and oral frailty risk (odds ratio: 2.67, 95% confidence interval: 1.57-4.51, P < 0.001) were independent factors for LUTS. Moreover, oral frailty risk was an independent factor in both participants aged < 65 years and participants aged ≥ 65 years. CONCLUSIONS: Oral frailty was independently associated with LUTS.

Detection of CCL25 and the correlation between CCL25, CCL28, IL-7, and TSLP in human breast milk.

In this study, CCL25, a chemokine that contributes to the immunological function of the thymus and intestines, was detected in human breast milk (HBM) for the first time. We then focused on the correlations of CCL25 with CCL28, TSLP, and IL-7, which were predicted to interact with CCL25 in HBM. We also compared their levels between primiparous and multiparous women. A total of 53 parturient women were recruited. Their HBM was collected during 0-5 days and at 1 month after parturition and the CCL25, CCL28, IL-7, and TSLP levels in the HBM were analyzed using ELISA. The results showed that CCL25 and TSLP levels were significantly higher in colostrum than in mature milk. Moreover, CCL28 and IL-7 levels in colostrum showed a positive correlation. These results indicate that CCL28 and IL-7 in colostrum might interact positively with each other when produced in the mammary glands during lactation. The findings also suggest that the level of parity has no effect on their levels in HBM. In conclusion, our results clarify that CCL25 is present in HBM and that the concentrations of CCL25 and TSLP are higher in colostrum than in mature milk. Moreover, the production of CCL28 and IL-7 might be closely correlated in human colostrum.

The relationship between cigarette smoking and the tongue microbiome in an East Asian population.

Background: The oral microbiome, which consists of various habitats, has been shown to be influenced by smoking. However, differences in the tongue microbiomes of current and former smokers, as well as their resultant functional consequences, have rarely been investigated in East Asian populations. Methods: We used 16S rRNA amplicon sequencing of tongue-coating samples obtained from East Asian subjects who were current, former, or never smokers to identify differences in their tongue microbiomes and related metagenomic functions. Two sets of participants from 2016 to 2017 (n = 657 and n = 187, respectively) were analyzed separately. Results: We found significant differences between the overall microbiome compositions of current versus never smokers (p = 0.0015), but not between former versus never smokers (p = 0.43) based on the weighted UniFrac distance. Twenty-nine of 43 investigated genera showed significantly different expression levels in current versus never smokers. Neisseria and Capnocytophaga were less abundant, and Streptococcus and Megasphaera were more abundant in current smokers. Moreover, the abundances of metagenomic pathways, including those related to nitrate reduction and the tricarboxylic acid cycle, were significantly different between current and never smokers. Conclusions: The tongue microbiomes and related metagenomic pathways of current smokers differ from those of never smokers among East Asians.

Metagenomic analysis of bacterial species in tongue microbiome of current and never smokers.

Cigarette smoking affects the oral microbiome, which is related to various systemic diseases. While studies that investigated the relationship between smoking and the oral microbiome by 16S rRNA amplicon sequencing have been performed, investigations involving metagenomic sequences are rare. We investigated the bacterial species composition in the tongue microbiome, as well as single-nucleotide variant (SNV) profiles and gene content of these species, in never and current smokers by utilizing metagenomic sequences. Among 234 never smokers and 52 current smokers, beta diversity, as assessed by weighted UniFrac measure, differed between never and current smokers (pseudo-F = 8.44, R2 = 0.028, p = 0.001). Among the 26 species that had sufficient coverage, the SNV profiles of Actinomyces graevenitzii, Megasphaera micronuciformis, Rothia mucilaginosa, Veillonella dispar, and one Veillonella sp. were significantly different between never and current smokers. Analysis of gene and pathway content revealed that genes related to the lipopolysaccharide biosynthesis pathway in Veillonella dispar were present more frequently in current smokers. We found that species-level tongue microbiome differed between never and current smokers, and 5 species from never and current smokers likely harbor different strains, as suggested by the difference in SNV frequency.

Epidermal growth factor receptor gene mutations in papillary thyroid carcinoma.

Recent studies have indicated that somatic mutations in the epidermal growth factor receptor (EGFR) gene have been identified in a subset of patients with nonsmall-cell lung cancer (NSCLC) and are associated with sensitivity to the EGFR-tyrosine-kinase inhibitors. These mutations have been reported to be almost exclusively found in a pulmonary adenocarcinoma subgroup of NSCLC, with a low frequency in other solid tumors. We describe a patient with advanced-stage papillary thyroid carcinoma (PTC) whose disease had been diagnosed as pulmonary adenocarcinoma at first, and who had a marked response to the EGFR-tyrosine-kinase inhibitor, gefitinib. An in-frame deletion in exon 19 that eliminated 4 amino acids at positions 746 through 750, which is one of the common drug-sensitive mutations in pulmonary adenocarcinoma, and a serine-to-proline substitution at codon 752, were found in a tumor specimen of the patient. We subsequently searched for mutations in the EGFR tyrosine kinase domain in primary tumors from 23 patients with PTC, and drug-sensitive mutations commonly observed in pulmonary adenocarcinoma were found in 7 of these patients. Our observation of a high frequency of the EGFR-activating mutations in PTC suggests that the EGFR mutation may be an important event in the development of PTC. EGFR gene amplification, also considered to be a predictor of response to EGFR-tyrosine-kinase inhibitors, was evaluated by fluorescence in situ hybridization (FISH); however, only 1 FISH-positive tumor was detected. Our data suggest that EGFR-tyrosine-kinase inhibitors may deserve consideration in the treatment of a subset of patients with PTC, just as with pulmonary adenocarcinoma.

Effects of oral environment on frailty: particular relevance of tongue pressure.

PURPOSE: Oral frailty or the loss of oral functionality can be a symptomatic precursor of overall frailty. Previous studies have suggested that decreased tongue pressure causes a decline in ingesting and swallowing function and poor nutrition. This study investigated what factor(s) contribute to tongue pressure, thereby leading to frailty. PATIENTS AND METHODS: For the purposes of the present study, 467 residents of Hirosaki city in northern Japan aged≥60 years who completed a questionnaire about frailty and underwent an intraoral assessment, which included number of teeth, presence or absence of periodontitis, tongue pressure, and oral diadochokinesis (ODK) were recruited. RESULTS: Of the 467 participants with complete data sets, frailty was identified in 13 (7.5%) of 173 males and in 34 (11.6%) of 294 females. Significantly fewer teeth, lower tongue pressure, and a reduced diadochokinetic syllable rate were more prevalent among frail than among healthy residents. Multivariable logistic regression analysis revealed that age, body mass index, number of teeth, and tongue pressure significantly contributed to frailty, whereas ODK did not. Multiple regression analysis showed that tongue pressure was positively associated with muscle index and number of teeth. CONCLUSION: The results of the present study suggest that fewer teeth and lower tongue pressure, but not ODK function, are risk factors for developing overall frailty among older residents.

Bone regeneration of canine skull using bone marrow-derived stromal cells and beta-tricalcium phosphate.

OBJECTIVE: The aim of this study was to regenerate high-quality cranial bone using tissue engineering techniques, with subsequent extension to clinical application. Our previous study with a 3-month observation period indicated that a composite scaffold composed primarily of beta-tricalcium phosphate (TCP) had the potential for cranial bone regeneration. In this study, we investigated whether bone marrow derived stromal cells (BSCs) could promote the regeneration of cranial bone as determined after 3 and 6 months. STUDY DESIGN: The pilot study was conducted with 14 adult beagle dogs. MATERIALS AND METHODS: Craniotomy was performed in the same manner used clinically. The bone defect (2 x 2 cm) was created at each canine temporoparietal region. The test animals were divided into three groups. In group I, the bone defect was closed by replacing the original free bone flap without filling the residual gaps. In group II, the gap was filled with a composite scaffold consisting of collagen coated beta-TCP and autologous bone fragments with fibrin glue. In group III, autologous cultured BSCs and the composite scaffold were used to fill the gap. The sites of craniotomy were analyzed with three-dimensional computed tomography and histologic examination 3 and 6 months after the operation. RESULTS: Bone regeneration was observed in groups II and III, with more extensive formation in group III than in group II. In group I, bone regeneration was not observed. CONCLUSION: This study showed that BSCs have the potential to promote cranial bone regeneration and confirmed the efficacy of a composite scaffold made of beta-TCP and autologous bone fragments with fibrin glue.

Tracheal regeneration after partial resection: a tissue engineering approach.

OBJECTIVES: The aims of this study are to investigate the efficiency of a tissue engineering approach to partial tracheal reconstruction and to improve epithelialization of the reconstructed trachea. The trachea must be resected in some cases of cancer or trauma. Various restructuring techniques are used, with no consensus on the best approach. Two problems that arise when treating tracheal defects by conventional techniques are an inability to regenerate ciliated epithelium at the reconstructed site and having to perform multiple procedures to achieve the desired repair. This study is designed to address these problems. STUDY DESIGN: Preliminary, an animal experiment. METHODS: Surgery was performed on five adult beagles under anesthesia. After the making of a longitudinal cervical skin incision, the trachea was exposed and a circular defect created. A polypropylene and collagen scaffold preclotted with peripheral blood was inserted to the defect site. Postoperatively, the site was evaluated fiberscopically, histologically, and radiographically. RESULTS: All dogs did well postoperatively. Fiberscopic examination showed that the implanted scaffolds were completely covered with regenerated mucosa with capillaries in all cases. Histologic data showed ciliated epithelium regenerated at the operated site from 1 month postoperatively. Newly formed cartilage was detected in the specimens from 8 to 12 postoperative months. Computed tomography images revealed the fine luminal contour of the regenerated site. CONCLUSIONS: Good epithelial regeneration was observed after repair of a round tracheal resection using a simple tissue engineering technique, making the technique a good substitute for conventional approaches to tracheal reconstruction in patients with cancer or trauma.

Drug delivery system of hepatocyte growth factor for the treatment of vocal fold scarring in a canine model.

OBJECTIVES: Vocal fold scarring remains a therapeutic challenge. Previous studies have indicated that hepatocyte growth factor (HGF), a strong antifibrotic element, has therapeutic potential for restoring scarred vocal folds. To enhance the effect of HGF in vivo, we developed a novel drug delivery system (DDS) in which HGF is embedded in gelatin hydrogel and continuously released over a period of 2 weeks. In the present study we investigated the therapeutic efficacy of the HGF DDS on vocal fold scarring by using a canine model. METHODS: The vocal folds of 8 beagles were unilaterally scarred by stripping the entire layer of the lamina propria. The contralateral vocal folds were kept intact as normal controls. One month after the procedure, hydrogels (0.5 mL) containing 1 microg of HGF were injected into the scarred vocal folds of 4 dogs (HGF-treated group), whereas hydrogels containing saline solution were injected in the other 4 dogs (sham group). Histologic and vibratory examinations were completed for each group 6 months after the initial surgery. RESULTS: The excised larynx experiments showed significantly better vibration in terms of mucosal wave amplitude and glottal closure in the HGF-treated group compared to the sham group. Histologic evaluation of the vocal folds indicated remarkable reduction in collagen deposition and tissue contraction, with favorable restoration of hyaluronic acid and elastin in the HGF-treated group. CONCLUSIONS: The present findings suggest that the novel HGF DDS may provide favorable effects in restoring the vibratory properties of scarred vocal folds.

A case of floppy epiglottis in adult: a simple surgical remedy.

A new operative technique for the treatment of floppy epiglottis is introduced in this report. Though its diagnosis is not so difficult by close observations using a flexible fiberscope, it is likely to be treated as an asthma attack or a paradoxical vocal cord movement. In previous reports of upper airway obstruction caused by adult floppy epiglottis: epiglottis prolapse during inspiration, the cause of this condition has been divided broadly into two categories: idiopathic cases and secondary cases. Partial or total epiglottectomy has been usually reported for the treatment of the relief of airway obstruction caused by a floppy epiglottis. It is very difficult to decide adequately how much volume of epiglottis to cut without postoperative sequelae. A V-shaped partial epiglottidectomy is described for its treatment. This technique is very easy, simple, and effective.

Oral conditions and dysphagia in Japanese, community-dwelling middle- and older- aged adults, independent in daily living.

PURPOSE: Prevention, early detection and effective rehabilitation of dysphagia are important issues to be considered in an aging society. Previous studies have shown conflicting findings regarding the association between dysphagia and its potential risk factors, including age, malnutrition, oral conditions, lifestyle and medical history. Herein, we assessed the prevalence and association of dysphagia with potential risk factors in 50- to 79-year-old adults dwelling in a community in Japan. PATIENTS AND METHODS: In this study, there were 532 participants (185 males and 347 females). Participants who responded positively to the question "Do you sometimes choke on drinks/food such as tea and soup?" or those who presented with abnormal repetitive saliva swallowing test findings were diagnosed with dysphagia. The data collected from these participants included the following: number of teeth, occurrence of oral dryness, age, body mass index, serum albumin concentration, smoking, drinking and exercise habits, presence of diseases, such as diabetes mellitus and hypertension, and questions from the Mini-Mental State Examination. RESULTS: Dysphagia was observed in 33 males (17.8%) and 76 females (21.9%). To explore the effect of the potential risk factors on the prevalence of dysphagia, a model was built by multivariate logistic regression analysis. Using the forced entry method, oral dryness (odds ratio [OR] =3.683 and P=0.003 in males; OR =1.797 and P=0.032 in females) and the number of teeth (OR =0.946 and P=0.038 in males) were found to be significantly related to dysphagia. CONCLUSION: This cross-sectional study demonstrated associations between oral conditions and dysphagia. Factors such as oral dryness and number of teeth may contribute to dysphagia more so than aging, lifestyle and comorbidity in community-dwelling adults over the age of 50.

Cranial bone regeneration using a composite scaffold of Beta-tricalcium phosphate, collagen, and autologous bone fragments.

OBJECTIVE: The aim of our study was to examine the tissue response and new bone formation induced by beta-tricalcium phosphate (beta-TCP), collagen, and autologous bone fragments with fibrin glue implanted into a cranial bone defect. MATERIALS AND METHODS: Granulated beta-TCP and collagen from porcine skin were mixed and freeze-dried. The weight ratio of both materials was 98:2. The composite scaffold for bone regeneration was composed of this artificial material and autologous bone fragments. Five adult beagle dogs were used. A cranial bone defect (2 cmx2 cm) was created in each dog. The animals were divided into two groups. In group 1 (n=3), the cranial bone defect was closed by replacing the original free bone flap, and the residual fissure and burr holes were filled with the composite scaffold with fibrin glue. In group 2 (n=2), the bone defect was closed only by replacing the original free bone flap. Three months after the treatment, computed tomography and histologic examinations were done in all animals. RESULTS: In all dogs in group 1, the defects were almost closed by new bone; whereas in group 2, the defects were filled with fibrous tissues instead of bone. CONCLUSION: This study showed that the composite scaffold made of beta-TCP, collagen, and autologous bone fragments with fibrin glue enabled reconstruction of cranial bone defects without the usual fixation materials.

Teeth and physical fitness in a community-dwelling 40 to 79-year-old Japanese population.

PURPOSE: Decline in the number of teeth and physical fitness begins from 40 years of age; however, several epidemiological studies have identified relationships between oral conditions and physical performance parameters in community-dwelling elderly population. The aim of this study was to validate the relationship between the muscle mass and its function and oral conditions (number of teeth and dental occlusion) after 40 years of age in a community-dwelling population in Japan. MATERIALS AND METHODS: The subjects comprised of 552 volunteers (198 males and 354 females, 40-79 years) who participated in the Iwaki Health Promotion Project in 2013. Multiple linear regression analyses were performed with the measures of the muscle mass and its function as objective variables and the measures of the number of teeth, age, body mass index, medical history, serum albumin concentration, smoking status, habitual alcohol intake, marital status, education levels, and exercising habits as explanatory variables. The relationships between the Eichner index and the muscle mass and its function were analyzed using analysis of covariance, with adjustment for confounding factors. RESULTS: After adjusting for confounding factors, the number of teeth was shown to be an independent risk factor for the timed 10 m walk test (in females) and the skeletal muscle mass of the whole body (in males). The results also revealed that the timed 10 m walk test was significantly correlated with the Eichner index (Classes A and C in females were correlated). CONCLUSION: This cross-sectional study on a Japanese community-dwelling population revealed relationships between oral conditions and the muscle mass and its function. However, the interpretation of our results was hampered by a lack of data, including those on socioeconomic status and longitudinal observations. Future research exploring teeth loss and the muscle mass and its function is warranted.

Destiny of autologous bone marrow-derived stromal cells implanted in the vocal fold.

OBJECTIVES: The aim of this study was to investigate the destiny of implanted autologous bone marrow-derived stromal cells (BSCs) containing mesenchymal stem cells. We previously reported the successful regeneration of an injured vocal fold through implantation of BSCs in a canine model. However, the fate of the implanted BSCs was not examined. In this study, implanted BSCs were traced in order to determine the type of tissues resulting at the injected site of the vocal fold. METHODS: After harvest of bone marrow from the femurs of green fluorescent transgenic mice, adherent cells were cultured and selectively amplified. By means of a fluorescence-activated cell sorter, it was confirmed that some cells were strongly positive for mesenchymal stem cell markers, including CD29, CD44, CD49e, and Sca-1. These cells were then injected into the injured vocal fold of a nude rat. Immunohistologic examination of the resected vocal folds was performed 8 weeks after treatment. RESULTS: The implanted cells were alive in the host tissues and showed positive expression for keratin and desmin, markers for epithelial tissue and muscle, respectively. The implanted BSCs differentiated into more than one tissue type in vivo. CONCLUSIONS: Cell-based tissue engineering using BSCs may improve the quality of the healing process in vocal fold injuries.

Aggressive Angiomyxoma of the Pelvis with a Cellular Nodule Composed of Tumor Cells showing Epithelioid Features.

A 49-year-old female presented with an aggressive pelvic angiomyxoma (AAM). The completely resected specimen revealed the usual myxedematous tumor with a nodule inside it. Histopathologically, the myxedematous area consisted of bland spindle-shaped cells in the background of blood vessels of varying calibers, and the nodule was composed of tumor cells with epithelioid features. In the nodule, cellularity was increased and nuclear enlargement was observed, but nuclear atypia was not significant and mitotic figures were scarce. Immunohistochemically, both components were positive for desim, αSMA, estrogen receptors, and progesterone receptors. However, they were negative for AE1/3, EMA, S100, CD34, HMB45, and Melan A. The MIB-1 labeling index was 5.8% in the nodule and 1ess than 1% outside it. The nodule was therefore considered a benign component of AAM. To the best of our knowledge, the presence of such a nodule in AAM has not been reported previously.

In situ tissue engineering of canine skull with guided bone regeneration.

CONCLUSION: Calcium alginate (CA) membrane prevents excessive fibrous tissue intrusion and/or dislocation of a bone scaffold. However, CA membrane did not always accelerate cranial bone regeneration. OBJECTIVE: We previously reported skull regeneration using a bone substitute material (BSM), which consisted of collagen-coated beta-tricalcium phosphate and autologous bone fragments, and bone marrow-derived stromal cells (BSCs). However, excessive fibrous tissue intrusion or dislocation of the BSM occasionally interrupted bone regeneration. To avoid such problems, we examined CA membrane, which is useful for guided bone regeneration (GBR), to investigate whether this material maintains the bone regenerative space. MATERIALS AND METHODS: Bone defects (2x2 cm) were created in the skulls of 12 adult beagle dogs using the same clinical procedure. Four experimental models were tested with or without BSM plus BSCs or CA membrane. In group I, the original free bone flap was replaced at the defect. In group II, after replacing the bone flap, the defect was covered with CA membrane. In group III, BSM plus BSCs were used as a gap filler. In group IV, BSM plus BSCs and CA membrane were applied. Histological examinations were performed 3 and 6 months after the operation. RESULTS: In groups I and II, bone regeneration was not observed but fibrous tissue intrusion was prevented in group II. Bone neogenesis was more observed in group III than in group IV at 3 months (p<0.05). At 6 months, the regenerated areas were larger than those observed at 3 months, but the differences between groups III and IV were not statistically significant.

Chemosensitivity determinants of irinotecan hydrochloride in hepatocellular carcinoma cell lines.

Irinotecan hydrochloride (CPT-11) is an effective anticancer drug, and its metabolic pathway has been well studied. Nevertheless, in human hepatocellular carcinoma (HCC), its cytotoxicity is less well studied and the determination of its chemosensitivity is unclear. We, therefore, examined chemosensitivities of HCC cell lines for CPT-11 and SN-38, and mRNA expressions of several molecules in their metabolic pathway. Three markers were found to correlate well with chemosensitivity: breast cancer resistance protein (BCRP), cytochrome P450 (CYP) 3A4 and uridine diphosphate-glucuronosyl transferase (UGT) 1A1. Next, CYP3A4/UGT1A1/BCRP inhibitor naringenin and BCRP inhibitor elacridar were tested for enhancement of their chemosensitivity. Both of naringenin and elacridar separately enhanced the sensitivity for CPT-11 and SN-38 in KYN-2 cells abundantly expressing BCRP, CYP3A4/5 and UGT1A1, but not in KYN-1 cells expressing lower levels. However, naringenin had little effect on the sensitivity in JHH-4 and HLE cells with higher CYP3A4/5 and lower UGT1A1 and BCRP expression. On the other hand, naringenin and elacridar significantly increased the chemosensitivity for CPT-11 and SN-38 in the KYN-1-derived cells artificially overexpressing BCRP. Furthermore, flow cytometric analysis showed that naringenin raised intracellular accumulation of CPT-11 as well as elacridar. Those results suggest that BCRP is one of the chemosensitivity determinants of CPT-11 in HCC cells and its inhibition might be critical for cells expressing abundant BCRP.