Comparative study on the effects of micro- and nano-sized zinc oxide supplementation on zinc-deficient mice

BACKGROUND

Zinc (Zn) is an essential cofactor for physiological homeostasis in the body. Zn oxide (ZnO), an inorganic compound that supplies Zn, exists in various sizes, and its bioavailability may vary depending on the size in vivo. However, comparative studies on the nutritional effects of micro-sized ZnO (M-ZnO) and nano-sized ZnO (N-ZnO) supplementation on Zn deficiency (ZnD) animal models have not been reported.

OBJECTIVES

This study investigated the nutritional bioavailability of N-ZnO and M-ZnO particles in dietary-induced ZnD mice.

METHODS

Animals were divided into six experimental groups: normal group, ZnD control group, and four ZnO treatment groups (Nano-Low, Nano-High, Micro-Low, and Micro-High). After ZnD induction, N-ZnO or M-ZnO was administered orally every day for 4 weeks.

RESULTS

ZnD-associated clinical signs almost disappeared 7 days after N-ZnO or M-ZnO administration. Serum Zn concentrations were higher in the Nano-High group than in the ZnD and M-ZnO groups on day 7 of ZnO treatment. In the liver and testis, Nano-Low and Nano-High groups showed significantly higher Zn concentrations than the other groups after 14-day treatment. ZnO supplementation increased Mt-1 mRNA expression in the liver and testis and Mt-2 mRNA expression in the liver. Based on hematoxylin-and-eosin staining results, N-ZnO supplementation alleviated histological damage induced by ZnD in the testis and liver.

CONCLUSIONS

This study suggested that N-ZnO can be utilized faster than M-ZnO for nutritional restoration at the early stage of ZnD condition and presented Mt-1 as an indicator of Zn status in the serum, liver, and testis.

Epigallocatechin-3-gallate suppresses hemin-aggravated colon carcinogenesis through Nrf2-inhibited mitochondrial reactive oxygen species accumulation

BACKGROUND

Previous studies have presented evidence to support the significant association between red meat intake and colon cancer, suggesting that heme iron plays a key role in colon carcinogenesis. Epigallocatechin-3-gallate (EGCG), the major constituent of green tea, exhibits anti-oxidative and anti-cancer effects. However, the effect of EGCG on red meat-associated colon carcinogenesis is not well understood.

OBJECTIVES

We aimed to investigate the regulatory effects of hemin and EGCG on colon carcinogenesis and the underlying mechanism of action.

METHODS

Hemin and EGCG were treated in Caco2 cells to perform the water-soluble tetrazolium salt-1 assay, lactate dehydrogenase release assay, reactive oxygen species (ROS) detection assay, real-time quantitative polymerase chain reaction and western blot. We investigated the regulatory effects of hemin and EGCG on an azoxymethane (AOM) and dextran sodium sulfate (DSS)-induced colon carcinogenesis mouse model.

RESULTS

In Caco2 cells, hemin increased cell proliferation and the expression of cell cycle regulatory proteins, and ROS levels. EGCG suppressed hemin-induced cell proliferation and cell cycle regulatory protein expression as well as mitochondrial ROS accumulation. Hemin increased nuclear factor erythroid-2-related factor 2 (Nrf2) expression, but decreased Keap1 expression. EGCG enhanced hemin-induced Nrf2 and antioxidant gene expression. Nrf2 inhibitor reversed EGCG reduced cell proliferation and cell cycle regulatory protein expression. In AOM/DSS mice, hemin treatment induced hyperplastic changes in colon tissues, inhibited by EGCG supplementation. EGCG reduced the hemin-induced numbers of total aberrant crypts and malondialdehyde concentration in the AOM/DSS model.

CONCLUSIONS

We demonstrated that EGCG reduced hemin-induced proliferation and colon carcinogenesis through Nrf2-inhibited mitochondrial ROS accumulation.

Ectopic pregnancy occurring in the remnant tube of a previous adnexectomy: a case report

Ectopic pregnancy occurring in the same region is a comparatively rare disease, but sometimes it is very serious to patients if it is delayed. The authors present a case of spontaneous ectopic pregnancy occurring in the ipsilateral salpingectomy stump of a previous adnexectomy that was successfully removed via laparoscopic surgery without complication. This case may support the idea of intrauterine transmigration of a fertilized egg as an etiology of spontaneous ectopic pregnancy. Thus, the potential for ectopic pregnancy in the tubal remnant in cases of previous salpingectomy or adnexectomy needs to be carefully considered.

Routine endoscopic screening for synchronous esophageal neoplasm in patients with head and neck squamous cell carcinoma: a prospective study

Early detection of synchronous esophageal squamous cell neoplasm (ESCN) in head and neck squamous cell carcinoma (HNSCC) patients can significantly affect their prognosis. We investigated the prevalence of synchronous ESCN and the risk factors for developing ESCN in patients with HNSCC, and evaluated the effect of routine endoscopic screening in these patients. Subjects who were diagnosed as HNSCC from May 2010 to January 2014 were eligible. All patients underwent conventional white light endoscopic examinations with narrow band imaging and Lugol chromoendoscopy. Among 458 subjects screened, 28 synchronous ESCN were detected in 24 patients (5.2%). The prevalence of ESCN was greatest in patients with hypopharyngeal cancer (20.9%). In multivariate analysis, pyriform sinus involvement was independent risk factor for developing synchronous ESCN (odds ratio 171.2, P < 0.001). During the follow-up period (median, 24 months), the 3-year overall survival rates was significantly lower in patients with ESCN than in patients without ESCN (54.2% vs. 78.3%, P = 0.0013). Routine endoscopic screening for detecting synchronous ESCN should be recommended for patients with HNSCC, especially those with pyriform sinus involvement.

Ethanol and/or radiofrequency ablation to treat venolymphatic malformations that manifest as a bulging mass in the head and neck

AIM

To evaluate the efficacy of ultrasound (US)-guided ethanol ablation (EA) and radiofrequency ablation (RFA) for treating venolymphatic malformations (VLM) of the head and neck.

MATERIALS AND METHODS

US-guided EA and/or RFA were performed on 17 patients with VLM of the head and neck. Computed tomography (CT) or magnetic resonance imaging (MRI) was used to locate the cranial nerves and salivary gland ducts that were close to targets, and these were avoided during the procedures. Treatment response was assessed using volume reduction and cosmetic grading scoring.

RESULTS

Nine VLMs were located close to the functional structures: Stensen's duct (n=3), cranial nerve branch (n=3), or both (n=3). All patients demonstrated >50% volume reduction, except one patient with a microcystic lymphatic malformation that was abutting the facial nerve. Median cosmetic grading scores improved from 4 to 1 (p<0.001).

CONCLUSION

US-guided EA and/or RFA are effective and safe treatment methods in patients with VLMs of the head and neck. Treatment selection of EA and/or RFA could be performed based on the composition of VLMs as assessed at CT and MRI.

Comparison of fine-needle aspiration and core needle biopsy under ultrasonographic guidance for detecting malignancy and for the tissue-specific diagnosis of salivary gland tumors

BACKGROUND AND PURPOSE

Diagnostic test accuracy studies for ultrasonography-guided fine-needle aspiration and ultrasonography-guided core needle biopsy have shown inconclusive results due to their heterogenous study designs. Our aim was to compare the diagnostic accuracy of ultrasonography-guided fine-needle aspiration versus ultrasonography-guided core needle biopsy for detecting malignant tumors of the salivary gland and for the tissue-specific diagnosis of salivary gland tumors in a single tertiary hospital.

MATERIALS AND METHODS

This retrospective study was approved by our institutional review board and informed consent was waived. Four hundred twelve patients who underwent ultrasonography-guided fine-needle aspiration (n = 155) or ultrasonography-guided core needle biopsy (n = 257) with subsequent surgical confirmation or clinical follow-up were enrolled. We compared the diagnostic accuracy of ultrasonography-guided fine-needle aspiration and ultrasonography-guided core needle biopsy regarding malignant salivary gland tumors and the correct tissue-specific diagnosis of benign and malignant tumors. We also tested the difference between these procedures according to the operator's experience and lesion characteristics.

RESULTS

The inconclusive rates of ultrasonography-guided fine-needle aspiration and ultrasonography-guided core needle biopsy were 19% and 4%, respectively (P < .001). The overall accuracy of ultrasonography-guided core needle biopsy for diagnosing malignant tumors was significantly higher than that of ultrasonography-guided fine-needle aspiration (P = .024). The correct tissue-specific diagnosis rates of ultrasonography-guided fine-needle aspiration and ultrasonography-guided core needle biopsy were 95% versus 97% for benign tumors (P = .648) and 67% versus 80% for malignant tumors (P = .310). Trainees showed significantly lower accuracy with ultrasonography-guided fine-needle aspiration than with ultrasonography-guided core needle biopsy for diagnosing malignant tumors (P = .021). There was no difference between the diagnostic accuracy of ultrasonography-guided fine-needle aspiration and ultrasonography-guided core needle biopsy according to the internal composition of the lesions. There were no complications requiring intervention or hospitalization in our patients.

CONCLUSIONS

Ultrasonography-guided core needle biopsy is superior to ultrasonography-guided fine-needle aspiration in detecting and characterizing malignant tumors of the salivary gland and could emerge as the diagnostic method of choice for patients presenting with a salivary gland mass.

PPARγ induces growth inhibition and apoptosis through upregulation of insulin-like growth factor-binding protein-3 in gastric cancer cells

Peroxisome proliferator activator receptor-gamma (PPARγ) is a ligand-activated transcriptional factor involved in the carcinogenesis of various cancers. Insulin-like growth factor-binding protein-3 (IGFBP-3) is a tumor suppressor gene that has anti-apoptotic activity. The purpose of this study was to investigate the anticancer mechanism of PPARγ with respect to IGFBP-3. PPARγ was overexpressed in SNU-668 gastric cancer cells using an adenovirus gene transfer system. The cells in which PPARγ was overexpressed exhibited growth inhibition, induction of apoptosis, and a significant increase in IGFBP-3 expression. We investigated the underlying molecular mechanisms of PPARγ in SNU-668 cells using an IGFBP-3 promoter/luciferase reporter system. Luciferase activity was increased up to 15-fold in PPARγ transfected cells, suggesting that PPARγ may directly interact with IGFBP-3 promoter to induce its expression. Deletion analysis of the IGFBP-3 promoter showed that luciferase activity was markedly reduced in cells without putative p53-binding sites (-Δ1755, -Δ1795). This suggests that the critical PPARγ-response region is located within the p53-binding region of the IGFBP-3 promoter. We further demonstrated an increase in PPARγ-induced luciferase activity even in cells treated with siRNA to silence p53 expression. Taken together, these data suggest that PPARγ exhibits its anticancer effect by increasing IGFBP-3 expression, and that IGFBP-3 is a significant tumor suppressor.

A Dual Gold Nanoparticle System for Mesenchymal Stem Cell Tracking

Stem cell-based therapies have demonstrated improved outcomes in preclinical and clinical trials for treating cardiovascular ischemic diseases. However, the contribution of stem cells to vascular repair is poorly understood. To elucidate these mechanisms, many have attempted to monitor stem cells following their delivery in vivo, but these studies have been limited by the fact that many contrast agents, including nanoparticles, are commonly passed on to non-stem cells in vivo. Specifically, cells of the reticuloendothelial system, such as macrophages, frequently endocytose free contrast agents, resulting in the monitoring of macrophages instead of the stem cell therapy. Here we demonstrate a dual gold nanoparticle system which is capable of monitoring both delivered stem cells and infiltrating macrophages using photoacoustic imaging. In vitro analysis confirmed preferential labeling of the two cell types with their respective nanoparticles and the maintenance of cell function following nanoparticle labeling. In addition, delivery of the system within a rat hind limb ischemia model demonstrated the ability to monitor stem cells and distinguish and quantify macrophage infiltration. These findings were confirmed by histology and mass spectrometry analysis. This work has important implications for cell tracking and monitoring cell-based therapies.

Distribution and accumulation of Cy5.5-labeled thermally cross-linked superparamagnetic iron oxide nanoparticles in the tissues of ICR mice

Free Cy5.5 dye and Cy5.5-labeled thermally cross-linked superparamagnetic iron oxide nanoparticles (TCL-SPION) have been routinely used for in vivo optical imaging. However, there is little information about the distribution and accumulation of free Cy5.5 dye and Cy5.5-labeled TCL-SPION in the tissues of mice. Free Cy5.5 dye (0.1 mg/kg body weight) and Cy5.5-labeled TCL-SPION (15 mg/kg body weight) were intravenously injected into the tail vein of ICR mice. The biodistribution and accumulation of the TCL-SPION and Cy5.5 were observed by ex vivo optical imaging and fluorescence signal generation at various time points over 28 days. Cy5.5 dye fluorescence in various organs was rapidly eliminated from 0.5 to 24 h post-injection. Fluorescence intensity of Cy5.5 dye in the liver, lung, kidney, and stomach was fairly strong at the early time points within 1 day post-injection. Cy5.5-labeled TCL-SPION had the highest fluorescence density in the lung at 0.5 h post-injection and decreased rapidly over time. Fluorescence density in liver and spleen was maintained over 28 days. These results suggest that TCL-SPION can be useful as a carrier of therapeutic reagents to treat diseases by persisting for long periods of time in the body.

Phospho-Rb (Ser780) as a biomarker in patients with cervical lymph node metastases from an unknown primary tumour: a retrospective cohort study

OBJECTIVES

Cervical lymph node metastases from an unknown primary tumour are a heterogeneous disease entity with various clinical features. There are many controversies regarding treatment methods and treatment response predictions. Therefore, we examined the prognostic significance of biomarkers in patients with cervical metastasis of unknown primary tumour.

DESIGN

A molecular study of retrospective cohorts.

SETTING

University teaching hospital.

MAIN OUTCOME MEASURES

Metastatic cervical lymph nodes of 36 patients with cervical unknown primary metastasis of squamous cell carcinoma were assessed by in situ hybridisation for human papillomavirus and immunohistochemistry for p16, retinoblastoma protein (phospho-Ser780), hypoxia-inducible factor-1α, glucose transporter 1 and carbonic anhydrase 9 expression. Clinicopathological factors and biomarkers were analysed for their associations with disease-free survival and overall survival.

RESULTS

Univariate analysis showed that nodal extracapsular spread was associated with poor overall survival (P = 0.049), nodal-positive retinoblastoma protein staining were significantly associated with poor outcomes of both disease-free survival (P = 0.035) and overall survival (P = 0.019), Multivariate analysis revealed that nodal positivity of retinoblastoma protein and nodal extracapsular spread were the significant predictors of overall survival (P = 0.049, hazard ratio = 6.21, 95% confidence interval = 1.01-38.35 and P = 0.037, hazard ratio = 4.34, 95% confidence interval = 1.09-17.21, respectively).

CONCLUSION

The retinoblastoma protein expression of metastatic lymph nodes represents an independent prognostic indicator in patients with cervical metastasis of unknown primary tumour.

Postoperative hypoalbuminemia as a risk factor for surgical site infection after oral cancer surgery

OBJECTIVES

Postoperative surgical site infection (SSI) is a frequent postoperative complication in patients with oral cancer and significantly affects patient recovery and medical expenses. The aim of this study was to examine the predictors of SSI in patients undergoing major surgery for oral or oropharyngeal squamous cell carcinoma (OSCC) and to determine the relationship between perioperative albumin and the development of SSI.

SUBJECTS AND METHODS

In 337 consecutive patients who underwent clean-contaminated surgery for OSCC, serum albumin, glucose, and hemoglobin levels were perioperatively measured. Differences between the groups were examined using Fisher's exact test, Mann-Whitney U-test, and multiple logistic regression analysis.

RESULTS

Surgical site infection was detected in 88 (26.1%) patients with median time to development of 10 (2-25) days. Multiple logistic regression analysis showed that only postoperative serum albumin < 2.5 g dl(-1) was an independent variable predictive of SSI (P = 0.003). The duration of hospital stay was negatively correlated with postoperative albumin (R(2) = -0.302, P < 0.001).

CONCLUSION

Early postoperative hypoalbuminemia <2.5 g dl(-1) is an independent risk factor for the development of SSI in patients undergoing oral cancer surgery. Clinicians should be aware of the implications of postoperative hypoalbuminemia and consider more intensive postoperative care in these patients.

Noncancer health events as a leading cause of competing mortality in advanced head and neck cancer

BACKGROUND

The survival of patients with head and neck squamous cell carcinoma (HNSCC) can be affected by noncancer health events (NCHE) as well as by index cancer progression and second primary cancer (SPC). This study aimed to investigate the risk factors for NCHE and noncancer mortality (NCM) in patients with advanced-stage HNSCC.

PATIENTS AND METHODS

This cohort study involved 600 consecutive patients with overall stage III to IV HNSCC who were treated between 2001 and 2010 at our tertiary referral hospital. NCHE was defined as re-admission (i.e. after the primary treatments for the index tumors) due to noncancer-related causes. The incidences of NCHE and NCM and their risk factors were analyzed by using cumulative incidence and cause-specific hazard functions.

RESULTS

During a median follow-up period of 54 months, 224 (37.3%) and 55 (9.2%) of the 600 patients had NCHE and NCM, respectively. The 5-year index cancer mortality, SPC mortality, and NCM rates were 23.8%, 4.2%, and 8.9%, respectively. Multivariate analyses revealed that body mass index <20 kg/m(2) (P = 0.018), Charlson comorbidity index (CCI) ≥1 (P < 0.001), tumor recurrence (P < 0.001), SPC occurrence (P < 0.001), and initial chemotherapy (P = 0.049) were independent NCHE predictors. Older age (P < 0.001), CCI ≥1 (P = 0.008), tumor recurrence (P < 0.001), and SPC occurrence (P = 0.047) were independent NCM predictors. Patients with respiratory NCHE were at a higher risk of NCM than patients with other NCHE types (P < 0.001).

CONCLUSIONS

One or more comorbidities, tumor recurrence, and SPC occurrence were independent predictors of both NCHE and NCM. Patients with respiratory NCHE had a particularly high risk of NCM.

(18)F-FDG PET/CT surveillance at 3-6 and 12 months for detection of recurrence and second primary cancer in patients with head and neck squamous cell carcinoma

Background:

Early detection of recurrence of head and neck squamous cell carcinoma (HNSCC), which is often obscured by surgical or radiotherapy-induced tissue distortion, is essential for proper patient management.

Methods:

A total of 143 consecutive patients with previously untreated HNSCC were evaluated by whole-body fluorine 18-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) and regular clinical follow-up after curative treatment. The ¹⁸F-FDG PET/CT was performed ∼3–6 and 12 months after treatment and findings suspicious for recurrence or SPC were confirmed using histopathology.

Results:

The sensitivities of 3–6- and 12-month PET/CT scans at patient level were 96% and 93%, respectively, and those of regular clinical follow-up were 11% and 19%, respectively (McNemar test, P<0.001). In patients with no clinical suspicion, PET/CT detected 95% and 91% of recurrent patients at 3–6 and 12 months, respectively. The sensitivity of PET/CT for the identification of SPC was 29% and 80% at 3–6 and 12 months, respectively. A positive interpretation of PET/CT was significantly associated with poor overall survival (log-rank test, P<0.001).

Conclusion:

The ¹⁸F-FDG PET/CT surveillance is beneficial for the detection of recurrence that may be missed by regular follow-up physical and endoscopic examinations of the head and neck area after curative treatment for HNSCC.

Utility of quantitative 18 F-fluorodeoxyglucose uptake measurement to identify occult tonsillar carcinoma in patients with cervical metastasis of unknown primary tumours: a retrospective case-control study

OBJECTIVES

Due to relatively high (18) F-fluorodeoxyglucose accumulation in the tonsillar region, the detection of occult tonsillar cancers by (18) F-fluorodeoxyglucose positron emission tomography/computerised tomography remains controversial. Therefore, we assessed the usefulness of quantitative tonsil (18) F-fluorodeoxyglucose uptake in identifying occult tonsillar squamous cell carcinoma.

DESIGN

A case-control study of retrospective cohorts.

SETTING

University Teaching Hospital.

MAIN OUTCOME MEASURES

We assessed all patients diagnosed with tonsillar cancers or cervical lymph node metastasis of unknown primary tumours between 2005 and 2010 who underwent (18) F-fluorodeoxyglucose positron emission tomography/computerised tomography. The subjects were grouped into A (apparent early pT-stage tonsillar squamous cell carcinoma; n = 27), B (occult tonsillar squamous cell carcinoma, primary tumours were found by surgery; n = 21), C (cervical metastasis of unknown primary tumour, primary tumours were not found by surgery and for follow-up; n = 16) and D (33 healthy controls). Tonsillar maximum standardised uptake values were bilaterally measured and compared between groups.

RESULTS

The sensitivity and specificity of qualitative assessment of (18) F-fluorodeoxyglucose positron emission tomography/computerised tomography for detection of occult tonsillar cancers were 67% and 69%, respectively. Mean maximum standardised uptake values of tonsils with cancer were 11.19 ± 5.46 in group A and 8.12 ± 4.52 in group B, which were significantly higher than that of group C (4.62 ± 1.76) or group D (4.57 ± 1.62) (P < 0.01). The mean maximum standardised uptake value differences of groups A (6.35) and B (3.11) were significantly greater than those of groups C (0.32) and D (0.59) (P < 0.01). Similarly, the mean maximum standardised uptake value ratios of groups A (2.47) and B (1.73) were significantly greater than those of groups C (1.06) and D (1.16) (P < 0.01).

CONCLUSION

(18) F-fluorodeoxyglucose positron emission tomography/computerised tomography with tonsil SUVmax measurement is useful to identify occult tonsillar squamous cell carcinoma.

Preoperative detection and predictors of level V lymph node metastasis in patients with papillary thyroid carcinoma

Background

Papillary thyroid carcinoma (PTC) frequently metastasizes to regional lymph nodes. Metastasis to the posterior neck, level V, is uncommon, and level V lymphadenectomy may lead to spinal accessory nerve injury and associated postoperative morbidities. The aim of this study was to assess the diagnostic efficiency of preoperative ultrasonography and to identify predictors of level V metastasis in patients with PTC.

Methods

This study involved patients with previously untreated PTC that had metastasized to the lateral neck, and who underwent total thyroidectomy with central and lateral neck dissection. Histopathological findings were compared with ultrasound results for various neck levels. Clinical and histopathological factors that predicted level V metastasis were identified.

Results

Of 143 patients, 26 (18·2 per cent) had lymph node metastasis at level V. The sensitivity and positive predictive value of ultrasonography for level V metastasis were 46·2 and 30·0 per cent respectively. Univariable analysis showed that male sex, extranodal disease extension, a metastatic lymph node ratio in the ipsilateral lateral neck of more than 0·2, and simultaneous involvement of ipsilateral levels II–IV or level III were associated with ipsilateral level V metastasis. Multivariable analysis revealed an independent association between macroscopic extranodal disease extension and level V metastasis (odds ratio 26·05, 95 per cent confidence interval 5·63 to 120·56; P &lt; 0·001).

Conclusion

Preoperative ultrasonography frequently failed to detect level V metastasis in patients with metastatic PTC. Level V lymphadenectomy may be considered in patients with lymph node metastasis in the ipsilateral lateral neck with macroscopic extranodal extension.

Treatment results of post-operative radiotherapy in patients with salivary duct carcinoma of the major salivary glands

OBJECTIVE

Salivary duct carcinoma (SDC) is a rare malignancy of high-grade pathological type. We evaluated clinical outcomes and prognostic factors in 35 patients with SDC treated post-operatively with adjuvant radiation.

METHODS

We retrospectively assessed overall survival, locoregional control and disease-free survival in 35 patients with SDC of the major salivary glands who underwent surgery and were subsequently treated with radiotherapy. The evaluated prognostic factors included gender, age, symptom duration, tumour site, tumour size, TNM classification, and the following pathological features: perineural invasion, lymphovascular invasion, extraparenchymal invasion and resection-margin status.

RESULTS

Of the 35 patients, 30 (85.7%) were male. Median age at initial diagnosis was 62 years (range 38-75 years). The parotid gland was the main site affected in 22 patients (62.9%). 18 patients (51.5%) had pathological T3/T4 tumours, and 26 (74.3%) showed pathological nodal involvement. Actuarial 5-year locoregional control, disease-free survival and overall survival rates were 63.3%, 47.4% and 55.1%, respectively. The cause-specific death rate was 31.4% (n=11). Pathological nodal involvement was correlated with distant metastasis (p=0.011). Lymphovascular invasion was significantly prognostic for distant metastasis-free survival (p=0.049), locoregional control (p=0.012) and overall survival (p=0.003) in a Cox proportional hazard model, whereas perineural invasion was only significantly prognostic for overall survival (p=0.005).

CONCLUSIONS

Surgery and post-operative radiotherapy were effective for locoregional control. Lymphovascular invasion and perineural invasion were significant prognostic factors in patients with SDC.

Suppressive effect of zinc on the formation of colonic preneoplastic lesions in the mouse fed high levels of dietary iron

We investigated the effect of zinc on the formation of colonic aberrant crypt foci induced by azoxymethane (AOM) followed by dextran sodium sulfate (DSS) in mice with high iron diet (HFe; 450 ppm iron). Sixweek old ICR mice were fed on high iron diets with combination of three different levels of zinc in diets, low-zinc (LZn; 0.01 ppm), medium-zinc (MZn; 0.1 ppm), and high-zinc (HZn; 1 ppm) for 12 weeks. Animals were received weekly intraperitoneal injections of AOM (10 mg/kg B.W. in saline) for 3 weeks followed by 2% DSS (molecular weight 36,000~50,000) in the drinking water for a week. To confirm the iron storage in the body, the hepatic iron concentration has been determine chemically and compared with histological assessment visualized by Prussian blue reaction. Aberrant crypt (AC) and aberrant crypt foci (ACF) were analyzed in the colonic mucosa of mouse fed high dietary iron. Superoxide dismutase (SOD) activity and thiobarbituric acid-reactive substances (TBARS) level were also investigated. Apoptosis in the preneoplastic lesion was determined by terminal deoxynucleotidyl transferase-mediated dUTP nickend labeling (TUNEL). In addition, immunohistochemistry of β-catenin was also performed on the mucous membrane of colon. The number of large ACF (≥ 4 AC/ACF), which possess greater tumorigenic potential, was significantly lower in MZn and HZn groups compared with LZn group. Cytosolic SOD activity in the liver was significantly higher in HZn group compared with LZn group. Hepatic MDA level was decreased significantly in HZn group compared with MZn and LZn groups. Apoptotic index was significantly higher in HZn group. Taken together, these findings indicate that dietary zinc might exert a protective effect against colonic preneoplastic lesion induced by AOM/DSS in ICR mice with high iron status, and suggest that dietary supplement of zinc might play a role in suppressing colon carcinogenesis in mice.

A hypoxia-dependent upregulation of hypoxia-inducible factor-1 by nuclear factor-κB promotes gastric tumour growth and angiogenesis

BACKGROUND

The underlying mechanisms involved in the activation of hypoxia-inducible factor-1 (HIF-1) in gastric cancer remain unclear. As nuclear factor-κB (NF-κB) as well as HIF-1 have been implicated in angiogenesis of various cancers, we investigated their relationship in gastric cancer.

METHODS

Nuclear expressions of HIF-1α and NF-κB/RelA were assessed in 251 human gastric carcinoma specimens by immunohistochemical tissue array analysis. Stable human gastric cancer cells, infected with a retroviral vector containing super-suppressive mutant form of IκBα (IκBαM), were used for animal studies as well as cell culture experiments. Xenografted tumours were measured and IκBαM effects on angiogenesis and HIF-1α activation were assessed by immunohistochemistry, western blotting, luciferase reporter assay, and semiquantitative reverse transcription-polymerase chain reaction. In addition, NF-κB effects on the HIF-1α degradation and synthesis were examined.

RESULTS

Hypoxia-inducible factor-1α activation positively correlated with RelA activation in clinical gastric cancer samples (P<0.001). The IκBαM overexpression suppressed tumour growth, microvessel density, and HIF-1α activation in xenografted tumours. Cell culture experiments showed that hypoxia-induced HIF-1α expression was reduced by NF-κB inhibition under hypoxic conditions at the translational level.

CONCLUSION

The hypoxia-dependent activation of the NF-κB/HIF-1α/VEGF pathway contributes, at least in part, to gastric cancer promotion via enhancement of angiogenesis.

Risk of hemorrhagic gastropathy associated with colonoscopy bowel preparation using oral sodium phosphate solution

BACKGROUND AND STUDY AIMS

Oral sodium phosphate (NaP) solution is widely used for colonoscopy bowel preparation and it may cause aphthous ulcers in the colon. Our aim was to evaluate whether oral NaP solution is associated with gastric mucosal lesions.

METHODS

A total of 20 070 individuals underwent esophagogastroduodenoscopy (EGD) with colonoscopy, and 4271 individuals underwent EGD without colonoscopy, for cancer screening. Oral NaP solutions were used for bowel preparation prior to colonoscopy. Hemorrhagic gastropathy was graded using a five-point scale for erosive mucosal injury. The effect of NaP bowel preparation on hemorrhagic gastropathy was estimated using multiple logistic regression analysis with odds ratios (ORs) and 95 % confidence intervals (CIs).

RESULTS

The incidence of hemorrhagic gastropathy was 1.6 % (70/4271) in the EGD only group and 4.0 % (809/20 070) in the EGD with colonoscopy group ( P < 0.001, unadjusted OR 2.55, 95 %CI 1.99 - 3.27). The ORs for mild (grade 1 - 2), moderate (grade 3), and severe (grade 4) hemorrhagic gastropathy according to NaP use were 1.92 (95 %CI 1.45 - 2.54), 4.72 (95 %CI 2.65 - 8.47), and 5.99 (95 %CI 1.46 - 24.63), respectively. After adjustment for confounding factors, NaP solution was a significant risk factor for acute hemorrhagic gastropathy in the multivariate analysis (OR 1.92, 95 %CI 1.34-2.74). In addition, male sex, a body mass index (kg/m (2)) of less than 20, concurrent use of antihypertensive or nonsteroidal anti-inflammatory drugs, and duodenal ulcers were independently associated with the development of hemorrhagic gastropathy. HELICOBACTER PYLORI infection and atrophic gastritis were negatively associated with hemorrhagic gastropathy.

CONCLUSION

Oral NaP bowel preparation for colonoscopy was associated with hemorrhagic gastropathy.

Anti-obesity activity of diglyceride containing conjugated linoleic acid in C57BL/6J ob/ob mice

This study was to investigate the anti-obesity effects of diglyceride (DG)-conjugated linoleic acid (CLA) containing 22% CLA as fatty acids in C57BL/6J ob/ob male mice. There were four experimental groups including vehicle control, DG, CLA, and DG-CLA. The test solutions of 750 mg/kg dose were orally administered to the mice everyday for 5 weeks. CLA treatments significantly decreased mean body weight in the obese mice throughout the experimental period compared to the control (p < 0.01). All test solutions significantly decreased the levels of triglyceride, glucose and free fatty acids in the serum compared with control (p < 0.05). The levels of total cholesterol were also significantly reduced in DG and DG-CLA groups compared with the control group (p < 0.05). CLA significantly decreased weights of renal and epididymal fats compared with the control (p < 0.05). DG and DG-CLA also significantly decreased the epididymal fat weights compared with the control (p < 0.05). A remarkable decrease in the number of lipid droplets and fat globules was observed in the livers of mice treated with DG, CLA, and DG-CLA compared to control. Treatments of DG and CLA actually increased the expression of peroxisome proliferator-activated receptor gamma. These results suggest that DG-CLA containing 22% CLA have a respectable anti-obesity effect by controlling serum lipids and fat metabolism.

Obesity and weight gain as risk factors for erosive oesophagitis in men

BACKGROUND

Although obesity and weight gain increase the risk for symptoms of gastro-oesophageal reflux disease, their association with erosive oesophagitis is still unclear in the male population.

AIM

To evaluate, in men, the association of body mass index (BMI) and weight gain with endoscopically proven erosive oesophagitis.

METHODS

A total of 8571 Korean men in a comprehensive screening cohort were enrolled. Effects of BMI and abdominal obesity on erosive oesophagitis were estimated with odds ratios (ORs) and 95% confidence intervals (CIs) using logistic regression analysis. We also evaluated the association between erosive oesophagitis and BMI change after 1-3 years.

RESULTS

The prevalence of erosive oesophagitis was 6.4% (552/8571). In univariate analysis, the ORs for erosive oesophagitis increased as BMI or waist circumference increased (P for trend <0.001, both). In multivariate analysis, OR for erosive oesophagitis increased as BMI increased (P for trend = 0.002), while the significance of waist circumference was attenuated (P for trend = 0.13). Increase in BMI (>or=1 kg/m2) was associated with persistence of erosive oesophagitis (OR = 2.83, 95% CI: 1.01-7.92, P = 0.04) and new development of the disease (OR = 2.13, 95% CI: 1.38-3.28, P = 0.001) compared with BMI change less than 1 kg/m2.

CONCLUSIONS

Elevated BMI and weight gain have a significant association with erosive oesophagitis.

Chemokines released from astrocytes promote chemokine receptor 5-mediated neuronal cell differentiation

Astrocytes are one of major glial cell types in the central nervous system (CNS), and can support many functions of neuronal cells. In the present study, we demonstrated that the differentiation of rat embryonic neuronal cells was promoted by treatment with astrocyte and microglia-conditioned medium. Cytokine assays identified that the IL-4, MIP-1, KC, and RANTES as were released from astrocyte, and these chemokines promote differentiation of rat embryonic neuronal cells. However, chemokine-promoted neuronal cell differentiation was suppressed by antibodies of these chemokines and their receptor (CCR5). CCR5 and neuronal cell differentiation marker proteins were found to be colocalized, and their expressions were enhanced by chemokines. Furthermore, the differentiation of neuronal cells from CCR5 knock-out mice and of neuronal cells from mice knocked down with the CCR5 siRNA were significantly reduced and delayed. Bradykinin elevated calcium influx in the embryonic neuronal cells. These data suggest that specific chemokines derived from astrocytes may significantly have influence on the CCR5-mediated differentiation of embryonic neuronal cells.

Obesity and weight gain as risk factors for erosive oesophagitis in men

BACKGROUND

Although obesity and weight gain increase the risk for symptoms of gastro-oesophageal reflux disease, their association with erosive oesophagitis is still unclear in the male population.

AIM

To evaluate, in men, the association of body mass index (BMI) and weight gain with endoscopically proven erosive oesophagitis.

METHODS

A total of 8571 Korean men in a comprehensive screening cohort were enrolled. Effects of BMI and abdominal obesity on erosive oesophagitis were estimated with odds ratios (ORs) and 95% confidence intervals (CIs) using logistic regression analysis. We also evaluated the association between erosive oesophagitis and BMI change after 1-3 years.

RESULTS

The prevalence of erosive oesophagitis was 6.4% (552/8571). In univariate analysis, the ORs for erosive oesophagitis increased as BMI or waist circumference increased (P for trend <0.001, both). In multivariate analysis, OR for erosive oesophagitis increased as BMI increased (P for trend = 0.002), while the significance of waist circumference was attenuated (P for trend = 0.13). Increase in BMI (>or=1 kg/m2) was associated with persistence of erosive oesophagitis (OR = 2.83, 95% CI: 1.01-7.92, P = 0.04) and new development of the disease (OR = 2.13, 95% CI: 1.38-3.28, P = 0.001) compared with BMI change less than 1 kg/m2.

CONCLUSIONS

Elevated BMI and weight gain have a significant association with erosive oesophagitis.

Reduced anxiety in the mice expressing mutant (N141I) presenilin 2

Alzheimer's disease (AD) is characterized by progressive cognitive impairment. The effect of presenilin 1 (PS1) and PS2 mutation on cognition has been well characterized in a variety of transgenic mice. However, noncognitive behaviors have not been considered in these mice. In the present study, we found that transgenic mice expressing mutant PS2 (N141I) displayed decreased anxiety behavior determined by the elevated plus maze test and the light dark box test. However, these mice showed biphasic ambulatory activity (hyperactivity followed by hypoactivity) in an open field test. Correlated well with the reduced anxiety, expression of GABA(A)alpha(1) receptor was higher whereas c-Fos was lower in the cortex, hippocampus, and amygdala of the mice expressing PS2 mutation than those of the wild-type PS2 or nontransgenic control mice. These data indicate that PS2 mutation causes reduction of anxiety, and this effect may be related to the change of the expression of GABA(A)alpha(1) receptor and c-Fos. These findings could be useful in the understanding and the treatment of AD patients.

The inhibitory effect of quercitrin gallate on iNOS expression induced by lipopolysaccharide in Balb/c mice

Quercetin 3-O-β-(2"-galloyl)-rhamnopyranoside (QGR) is a naturally occurring quercitrin gallate, which is a polyphenolic compound that was originally isolated from Persicaria lapathifolia (Polygonaceae). QGR has been shown to have an inhibitory effect on nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated macrophage RAW 264.7 cells. Therefore, this study was conducted to investigate the inhibitory effect of QGR on nitric oxide production and inducible nitric oxide synthases (iNOS) expression in LPS-stimulated Balb/c mice. To accomplish this, 10 mg/kg of QGR was administered via gavage once a day for 3 days. iNOS was then induced by intraperitoneal injection of LPS. Six hours after the LPS treatment the animals were sacrificed under ether anethesia. The serum levels of NO were then measured to determine if QGR exerted an inhibitory effect on NO production in vivo. LPS induced an approximately 6 fold increase in the expression of NO. However, oral administration of QGR reduced the LPS induced increase in NO by half. Furthermore, RT-PCR and western blot analysis revealed that the increased levels of iNOS expression that occurred in response to treatment with LPS were significantly attenuated in response to QGR pretreatment. Histologically, LPS induced the infiltration of polymorphonuclear neutrophils in portal veins and sinusoids and caused the formation of a large number of necrotic cells; however, pretreatment with QGR attenuated these LPS induced effects. Taken together, these results indicate that QGR inhibits iNOS expression in vivo as well as in vitro and has antiinflammatory potentials.

Effects of endocrine disrupting chemicals on expression of phospholipid hydroperoxide glutathione peroxidase mRNA in rat testes

Phospholipid hydroperoxide glutathione peroxidase (PHGPx), an antioxidative selenoprotein, is modulated by estrogen in the testis and oviduct. To examine whether potential endocrine disrupting chemicals (EDCs) affect the microenvironment of the testes, the expression patterns of PHGPxmRNA and histological changes were analyzed in 5-week-old Sprague-Dawley male rats exposed to several EDCs such as an androgenic compound [testosterone (50, 200, and 1,000 µg/kg)], anti-androgenic compounds [flutamide (1, 5, and 25 mg/kg), ketoconazole (0.2 and 1 mg/kg), and diethylhexyl phthalate (10, 50, and 250 mg/kg)], and estrogenic compounds [nonylphenol (10, 50, 100, and 250 mg/kg), octylphenol (10, 50, and 250 mg/kg), and diethylstilbestrol (10, 20, and 40 µg/kg)] daily for 3 weeks via oral administration. Mild proliferation of germ cells and hyperplasia of interstitial cells were observed in the testes of the flutamide-treated group and deletion of the germinal epithelium and sloughing of germ cells were observed in testes of the diethylstilbestrol-treated group. Treatment with testosterone was shown to slightly decrease PHGPxmRNA levels in testes by the reverse transcriptionpolymerase chain reaction. However, anti-androgenic compounds (flutamide, ketoconazole, and diethylhexyl phthalate) and estrogenic compounds (nonylphenol, octylphenol, and diethylstilbestrol) significantly upregulated PHGPxmRNA in the testes (p < 0.05). These findings indicate that the EDCs might have a detrimental effect on spermatogenesis via abnormal enhancement of PHGPx expression in testes and that PHGPx is useful as a biomarker for toxicity screening of estrogenic or antiandrogenic EDCs in testes.

Combined 18F-fluorodeoxyglucose-positron emission tomography and computed tomography as a primary screening method for detecting second primary cancers and distant metastases in patients with head and neck cancer

BACKGROUND

The aim of this study was to evaluate the ability of (18)F-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) to detect second primary cancers and distant metastases in patients with head and neck cancer (HNC).

PATIENTS AND METHODS

Patients with previous untreated HNC, between 2004 and 2005, underwent head and neck CT and whole-body FDG-PET/CT, before and at fixed intervals after therapy, for staging and detection of second primary cancers and distant metastases. Patients with malignant or equivocal findings on FDG-PET/CT underwent further imaging, endoscopy and/or biopsy.

RESULTS

Of the 349 eligible patients (267 men and 82 women), 14 (4.0%) had second primary cancers and 26 (7.4%) had distant metastases at initial staging or during mean follow-up of 15 months after treatment. FDG-PET/CT correctly identified second cancers or distant metastases in 39 of these 40 patients; there was one false negative and 23 false positive FDG-PET/CT results. Therefore, FDG-PET/CT had a sensitivity of 97.5%, a specificity of 92.6%, a positive predictive value of 62.9% and a negative predictive value of 99.7% in detecting second primary cancers and distant metastases.

CONCLUSION

Combined FDG-PET/CT is useful as a primary method for detecting second cancers and distant metastases in patients with HNC.

Estrogen receptor independent neurotoxic mechanism of bisphenol A, an environmental estrogen

Bisphenol A (BPA), a ubiquitous environmental contaminant, has been shown to cause developmental toxicity and carcinogenic effects. BPA may have physiological activity through estrogen receptor (ER) -α and -β, which are expressed in the central nervous system. We previously found that exposure of BPA to immature mice resulted in behavioral alternation, suggesting that overexposure of BPA could be neurotoxic. In this study, we further investigated the molecular neurotoxic mechanisms of BPA. BPA increased vulnerability (decrease of cell viability and differentiation, and increase of apoptotic cell death) of undifferentiated PC12 cells and cortical neuronal cells isolated from gestation 18 day rat embryos in a concentration-dependent manner (more than 50 µM). The ER antagonists, ICI 182,780, and tamoxifen, did not block these effects. The cell vulnerability against BPA was not significantly different in the PC12 cells overexpressing ER-α and ER-β compared with PC12 cells expressing vector alone. In addition, there was no difference observed between BPA and 17-β estradiol, a well-known agonist of ER receptor in the induction of neurotoxic responses. Further study of the mechanism showed that BPA significantly activated extracellular signal-regulated kinase (ERK) but inhibited anti-apoptotic nuclear factor kappa B (NF-κB) activation. In addition, ERK-specific inhibitor, PD 98,059, reversed BPA-induced cell death and restored NF-κB activity. This study demonstrated that exposure to BPA can cause neuronal cell death which may eventually be related with behavioral alternation in vivo. However, this neurotoxic effect may not be directly mediated through an ER receptor, as an ERK/NF-κB pathway may be more closely involved in BPA-induced neuronal toxicity.

Utility of FDG PET in patients with squamous cell carcinomas of the oral cavity

BACKGROUND

The utility of (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in oral cavity cancer has received little attention in a clinician's perspective. We systematically evaluated the clinical roles of FDG PET in patients with oral cavity squamous cell carcinomas (SCCs).

METHODS

Between August 2001 and February 2005, 82 new patients with resectable oral cavity SCCs underwent CT/MRI and FDG PET at initial staging and follow-up. The sensitivity and specificity of CT/MRI and FDG PET for neck metastases were compared with histopathologic reference of 67 patients who underwent neck dissection. The relationships between the maximal standardized uptake value (SUV) of primary tumors and clinicopathologic parameters, such as gender, age, tumor thickness, local invasiveness, T and N categories, tumor-node-metastasis stage, and histological grade, as well as with disease-free survival (DFS), were assessed.

RESULTS

FDG PET was more sensitive than CT/MRI for detecting cervical metastases on a level-by-level basis (38/43 vs. 28/43; P=0.002). Age, T and N categories, tumor thickness (>8mm) and SUV (>5.0) were also significant variables of 3-year DFS in univariate analysis. T category was an independent determinant of DFS in multivariate analysis (P<0.05). During a mean follow-up of 36 months, FDG PET correctly diagnosed locoregional recurrences in 20 patients, distant metastases in six and second cancers in five.

CONCLUSION

FDG PET may have potential roles in initial staging, survival prediction, and the detection of recurrences and second cancers.

Utility of 18F-fluorodeoxyglucose positron emission tomography in the preoperative staging of squamous cell carcinoma of the oropharynx

BACKGROUND

18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) has been reported to be superior to computed tomography (CT)/magnetic resonance imaging (MRI) in the evaluation of head and neck cancers, but little is known about its usefulness in oropharyngeal squamous cell carcinoma (SCC). We therefore compared FDG PET and CT/MRI in the preoperative staging of previously untreated oropharyngeal SCC.

METHODS

Thirty-two consecutive patients with oropharyngeal SCC underwent FDG PET and CT/MRI before surgery. Each method was interpreted separately to assess primary tumor and cervical node status. Their sensitivity and specificity were compared relative to histopathologic analysis.

RESULTS

Histopathology revealed metastases in 29 of 39 dissected neck sides and in 47 of 163 dissected cervical levels. FDG PET had higher sensitivities than CT/MRI for primary tumor detection (25/32 vs. 30/32, P=0.063) and for identification of cervical metastases on neck side (22/29 vs. 28/29, P<0.05) and level-by-level (37/47 vs. 45/47, P<0.05) bases. In contrast, the specificity of the two methods did not differ significantly (P>0.5). FDG PET correctly interpreted the false-negative results of CT/MRI in 6 of 7 primary tumors and 8 of 10 cervical levels.

CONCLUSIONS

The improved preoperative staging of FDG PET may help in planning treatment, but its accuracy is insufficient to replace pathologic staging based on neck dissection.

2-[18F]-Fluoro-2-deoxy-D-glucose positron emission tomography as guidance for primary treatment in patients with advanced-stage resectable squamous cell carcinoma of the larynx and hypopharynx

BACKGROUND

High uptake of 2-[(18)F]-fluoro-2-deoxy-D-glucose (FDG) is associated with unfavorable results. Pretreatment FDG uptake was evaluated as a predictor of survival and guidance for primary surgery or radiotherapy (RT) in patients with squamous cell carcinoma (SCC) of the larynx and hypopharynx.

MATERIALS AND METHODS

Seventy-nine consecutive patients with newly diagnosed advanced resectable SCC of the larynx and hypopharynx underwent FDG positron emission tomography (PET) before surgical resection plus RT and chemotherapy (surgery group, n=40) or RT with chemotherapy and surgical salvage (RT group, n=39). Age, tumor stage, histological grade, treatment strategy, and standardized uptake value (SUV) were analyzed for association with local control and survival.

RESULTS

Overall local control and survival in the two groups did not differ (P>0.1). In univariate analysis, nodal positivity (P=0.014) and SUV>8.0 (P=0.007) were associated with poorer disease-free survival (DFS). In multivariate analysis, SUV remained an independent determinant of DFS (P=0.014). When patients with SUV>8.0 in the two treatment groups were analyzed separately, those in the surgery group tended to have a higher 3-year DFS than those in the RT group, despite no statistical significance (48% vs. 27%, P=0.085).

CONCLUSIONS

High FDG uptake is associated with poor survival in patients with advanced laryngopharyngeal SCC. Patients with high FDG uptake may be better treated by surgical resection followed by RT and chemotherapy.

Prevalence of obesity in Korea

During the past decade, obesity has substantially increased in Korea, and this is leading to dramatic increases in complications such as type 2 diabetes. In this review, we discuss the past and the current situation of obesity in Korea based on the national health and nutrition surveys of 1995, 1998, and 2001. Because Korea is geographically isolated with relatively few migrants and has a low level of genetic heterogeneity, this report demonstrates the impact of environmental factors on the development of obesity beyond epidemiological information about one of the Asian countries. The third national health and nutrition survey reported in 2001 announced that the overall prevalence of obesity [body mass index (BMI) > or = 25.0 kg m(-2)] in Korean adults is 30.6% (32.4% in men and 29.4% in women). The prevalence of obesity in adults and children has increased rapidly from 1990s through the beginning of the new millennium and is steadily increasing in parallel with our rapid socio-economic progress. In particular, special attention should be paid to two groups in hormonal transition: first, middle-aged men and women who experience a great increase in body weight, BMI and waist circumference because of andropause or menopause, and second, adolescents in middle to high school who are preparing for qualification or entrance examinations and are prone to overnutrition or nutritional imbalance and physical inactivity.

Exposure to genistein does not adversely affect the reproductive system in adult male mice adapted to a soy-based commercial diet

Genistein, a soybean-originated isoflavone, is widely consumed by humans for putative beneficial health effects but its estrogenic activity may affect adversely the development of male reproductive system. Five-week-old ICR mice were purchased and fed with a soybean-based Purina Chow diet until 6 months of age. The animals were exposed by gavage to genistein (2.5 mg/kg/day) or 17beta-estradiol (7.5 microg/kg/day) for five weeks. Corn oil was used for the negative control. The animals were fed the casein-based AIN-76A diet throughout the experimental periods. There were no significant differences in body and organ weights of mice among experimental groups. No significant differences in sperm counts and sperm motile characteristics were found between the control and the genistein groups. Treatment of 17beta-estradiol caused a significant decrease in epididymal sperm counts compared to the control (p<0.05). The level of phospholipid hydroxide glutathione peroxidase in the epididymis of mice exposed to genistein was significantly higher than that of the control mice (p<0.05). 17beta-estradiol treatment caused a reduction of germ cells in the testis and hyperplasia of mucosal fold region in the prostate of mice. Genistein treatment did not cause any lesion in the testis, epididymis, and prostate. These results suggest that dietary uptake of genistein at adult stage of life may not affect male reproductive system and functions.

Reproductive Disorders in Pubertal and Adult Phase of the Male Rats Exposed to Vinclozolin during Puberty

Vinclozolin (VCZ) is a systemic dicarboximide fungicide with antiandrogenic activity. Reproductive toxicity of VCZ was investigated in male rats exposed to VCZ during puberty. Sprague-Dawley male rats aged with 35 days were assigned to six different groups; negative control, positive control receiving flutamide (100 mg/kg), VCZ (100, 200 and 400 mg/kg), and a combination of VCZ (200 mg/kg) + methyltestosterone (100 mg/kg). The animals were treated with test compounds by oral gavage daily during 35 to 44 days of age. In pubertal rats sacrificed on the next day after final treatment, VCZ or flutamide-treated group showed a decrease in weights of prostate, epididymis, and seminal vesicle, hypertrophy of Leydig cells in the testis, detached debris and sloughed cells in the tubules of the caput epididymis, and an increase in serum testosterone levels. On the other hand, combined treatment of VCZ + methyltestosterone decreased testicular weight, increased seminal vesicle weight, and induced degeneration of spermatocytes. In adult rats sacrificed at five weeks after final treatment, flutamide decreased testicular sperm counts, and VCZ, flutamide and VCZ + methyltestosterone also decreased epididymal sperm counts. In addition, treatment of VCZ (400 mg) or VCZ + methyltestosterone decreased some motion kinematic parameters of sperms including curvilinear velocity, mean angular displacement and lateral head displacement. Flutamide treatment also decreased lateral head displacement. These results indicate that VCZ exposure during pubertal period in male rats causes reproductive disorders in puberty and adulthood.

Nutrient removal using anaerobically fermented leachate of food waste in the BNR process

Nutrients removal efficiencies highly depend on the presence of biodegradable organic carbon in the biological nutrient removal (BNR) process but most domestic wastewater in Korea has shown a low C/N ratio and has a small amount of biodegradable COD (chemical oxygen demand). On the other hand, about 11,577 tons of food waste that contains a lot of organic material has been produced in Korea per day. The feasibility and applicability of anaerobically fermented leachate of food waste (AFLFW) as an external carbon source was examined in the laboratory-scale BNR process at different operation conditions with synthetic wastewater and domestic sewage. As the addition of AFLFW increased, the average removal efficiencies of SCOD, T-N, T-P changed from 96%, 60%, and 2% to 90%, 77%, and 67%, respectively. From anoxic nitrate utilization tests, it was observed that once the readily biodegradable COD (especially VFAs) was depleted, the denitrification rate reduced from 8.2 mg NO3-N/g VSS/hr to 0.7 mg NO3-N/g VSS/hr. From the molecular size distribution test, it was concluded that about 60% of soluble COD in effluent, which was considered to originate from AFLFW, had a large molecular size (> 30 kDa) that was not used by microorganisms.

Expression of Estrogen Receptor .ALPHA. and .BETA. in the Uterus and Vagina of Immature Rats Treated with 17-Ethinyl Estradiol

The action of estrogen on target organs has been actively studied with the discovery of estrogen receptor (ER) beta. This study was carried out to examine the expression of ERalpha and ERbeta in the uterus and the vagina of immature Sprague-Dawley rats treated with 17-ethinyl estradiol (EE). Twenty days old rats were subcutaneously treated with EE at the doses of 0 (vehicle control), 0.03, 0.3, 1.0, 3.0, and 10.0 microg/kg/day for three consecutive days. The treatment of EE at the doses of 0.3, 1.0, 3.0 and 10.0 microg/kg/day significantly increased the weights of the uterus and vagina of rats (p<0.01) and retained fluid in the uterus of rats. At the high doses of 3.0 and 10.0 microg/kg/day, the treatment of EE caused an increase in the uterine height, hypertrophy, and a decrease in the expression of ERalpha and ERbeta in the uterine luminal and glandular epithelium. The treatment of EE at the doses of 3.0 and 10.0 microg/kg/day also caused cornification and a decrease in the expression of ERalpha and ERbeta in the vaginal epithelium. These results suggest that the EE treatment decrease the expression of ERalpha and ERbeta in the uterus and vagina of immature rats and that may be associated with the morphological changes such as increase in the uterine height, hypertrophy of the uterine epithelium, and cornification of the vagina.

Inhibitory effects of long-chain fatty acids on VFA degradation and beta-oxidation

The inhibitory effects of major long-chain fatty acids (LCFA), which have 16 or 18 carbons, not only on acetate degradation, but also on propionate degradation and beta-oxidation were examined in anaerobic serum bottle tests at 35 degrees C with the acclimated granular sludges. A modified Gompertz equation described cumulative methane production to assess the rates of VFA degradation and beta-oxidation, which were applied to a simplified noncompetitive model and a simplified substrate inhibition model, respectively. The specific methane production rates on acetate decreased as LCFA concentration increased, which was in good agreement with the noncompetitive inhibition model. Unsaturated oleate (C18:1) and linoleate (C18:2) were more inhibitory than saturated stearate (C18:0) and palmitate (C16:0) on acetate degradation. LCFA inhibition on propionate degradation was similar to that for acetate; however, propionate degradation was less inhibited than acetate degradation. Beta-oxidation was the rate-limiting step in LCFA degradation in most cases. As LCFA concentration increased, beta-oxidation rate reached the maximum value, and then decreased, which confirmed the substrate inhibition of LCFA. Oleate, the most abundant LCFA in wastewater, could be degraded more quickly than saturated LCFA containing the same or even less carbon in spite of relatively high toxicity on acetate degradation.

Spermatogenetic Disorders in Adult Rats Exposed to Tributyltin Chloride during Puberty

Adverse effects of tributyltin (TBT) chloride were investigated on the reproductive system in male adult rats as exposed during puberty. Fifty Sprague-Dawley rats at the age of 35 days were assigned to five different groups: negative control receiving vehicle, methyltestosterone (10 mg/kg B.W.), and TBT chloride treatments (5, 10, and 20 mg/kg B.W.). Animals were treated by oral gavage for ten consecutive days and sacrificed at 5 weeks after final treatment. The treatment of TBT chloride at the high dose of 20 mg/kg B.W. significantly decreased homogenization-resistant testicular sperm counts (p<0.05). The TBT chloride treatment at the doses of 10 and 20 mg/kg B.W. also significantly decreased caudal epididymal sperm counts (p<0.01). Some of motion kinematic parameters (motility, mean angular displacement, lateral head displacement, and dance) of sperms retrieved from vasa deference were significantly decreased in rats treated with the TBT chloride at the dose of 20 mg/kg B.W. (p<0.05). These results provide a further evidence that an exposure to TBT chloride during pubertal period in male rats produces spermatogenic disorders characterized by decreasing testicular and epididymal sperm counts and some motion parameters of sperms in the vasa deference.

Effects of flutamide on puberty in male rats: an evaluation of the protocol for the assessment of pubertal development and thyroid function

To establish a test protocol for the rodent 20-d thyroid/pubertal assay, flutamide, a non-steroidal androgen antagonist, was administered to intact male Sprague-Dawley rats from postnatal d 33 for 20 d, and several reproductive endpoints were examined to assess the sensitivity of a number of parameters with respect to the detection of endocrine-related effects. Immature male rats were divided into 4 groups and given flutamide once daily by oral gavage at doses of 0, 1, 5, or 25 mg/kg/d. Prepuce separation was significantly delayed in flutamide-treated rats (5 and 25 mg/kg/d). One day after the last dose, the rats were sacrificed. Flutamide treatment resulted in a significant reduction in the weights of epididymides, ventral prostate, seminal vesicles plus coagulating glands and fluid, levator ani plus bulbocavernosus muscles, Cowper's glands, and glans penis. The weight of adrenal glands decreased at 25 mg/kg/d, while testes and any other organ weights were unaffected. No microscopic changes were observed in the thyroid glands. Serum levels of testosterone were significantly increased in the flutamide-treated groups (5 and 25 mg/ kg/d) and serum levels of estradiol were also increased (25 mg/kg/d). No differences were observed in the serum thyroxine levels. These results indicate that flutamide delays puberty in the male rat, and its mode of action appears to be via altered secretion of steroids, which subsequently affect the development of the reproductive tract. Thus, this assay might be used as an alternative for screening antiandrogenic activities of chemicals.

A hearing preservation technique for the resection of extensive jugular foramen tumors

OBJECTIVE

To describe a modified surgical approach for patients who maintain hearing function with jugular foramen tumors that extend to the posterior cranial fossa and the neck.

STUDY DESIGN

A retrospective review of 6 patients with jugular foramen tumors that were resected by a combined suboccipital and infralabyrinthine-transcervicomastoid approach.

METHODS

A combined suboccipital and infralabyrinthine-transcervicomastoid approach is characterized as follows: 1) There is no ablation of ear structures except the infralabyrinthine mastoid bone; the auricle is retracted anteriorly while preserving the bony wall and skin of the ear canal. 2) After superficial parotidectomy, a limited length of nerve VII from the intratemporal vertical segment is rerouted to divisions of the parotid portion. 3) The tumor is removed along with the internal jugular vein and sigmoid sinus, then the extended intracranial mass is resected through an additional suboccipital approach.

RESULTS

Five of the 6 patients had complete removal of all gross tumors. There were no major complications or mortalities. The preoperative levels of hearing were preserved in 5 of the 6 patients. Favorable facial function in the immediate postoperative period was noted in 4 of the 6 patients. Incomplete paralysis of 2 patients recovered eventually.

CONCLUSION

We propose that a combined suboccipital and infralabyrinthine-transcervicomastoid approach to the jugular foramen can provide sufficient exposure to resect most dumbbell-shaped tumors, and it could be the initial treatment of choice for patients with remnant hearing.

Suppression of tumorigenicity and metastasis in B16F10 cells by PTEN/MMAC1/TEP1 gene

PTEN/MMAC1/TEP1 (PTEN) is a tumor suppressor gene that is mutated in a variety of advanced and metastatic cancers, strongly suggests that PTEN alteration is possibly involved in the tumor progression and formation of metastases. However, the roles of PTEN in tumor growth and metastasis and its functional mechanisms are not fully understood. We evaluated the tumor suppressor function of PTEN gene on tumor growth and metastasis in vitro and in vivo. Our results of in vitro soft agar assay and in vivo PTEN-expressing tumor cell growth showed that PTEN inhibited the tumorigenicity of B16F10 melanoma cells. Anti-metastatic function of PTEN was also revealed by experimental pulmonary metastatic animal model. For the further insight into the mechanisms underlying the PTEN-mediated inhibition of tumor metastasis, we have examined the role of PTEN on the secretion of matrix metalloproteinases (MMPs), insulin-like growth factors (IGFs) and the expression of secretory and cellular vascular endothelial growth factor (VEGF) proteins that have been described to contribute to the metastasis of tumor. PTEN significantly lowered MMPs and IGFs secretion and also expression of secretory and cellular VEGF proteins. These results suggest that PTEN tumor suppressor protein inhibits tumorigenicity and metastasis through regulation of MMP, IGFs, and VEGF expression.

Cerebrospinal fluid and plasma concentrations of leptin, NPY, and alpha-MSH in obese women and their relationship to negative energy balance

Leptin and its principal mediators, NPY and alpha-MSH are postulated to play a pivotal role in energy balance. To determine the possibility of the disturbance in neuropeptides in human obesity and their consequent changes in response to negative energy balance, we evaluated plasma and cerebrospinal fluid (CSF) leptin, NPY, and alpha-MSH levels in obese women before and after weight loss in comparison with normal control women. Subjects included 16 obese women [mean body mass index (BMI), 35.6 kg/m(2)] before and after weight loss induced by a 2-wk very low caloric diet (800 kcal/d) and 14 normal weight women (mean BMI, 20.4 kg/m(2)). The CSF to plasma leptin ratio in normal weight subjects was 2.3-fold higher than that in obese subjects. After weight loss in obese subjects, plasma leptin levels decreased by 40% and CSF levels decreased by 51%. There was a positive linear correlation between CSF and plasma leptin levels at baseline in obese subjects (r = 0.74, P < 0.05) and a positive logarithmic correlation in normal weight subjects (r = 0.89, P < 0.05) and in obese subjects after weight loss (r = 0.64, P < 0.05). The BMI was negatively correlated with the CSF to plasma leptin ratio (r = -0.86, P < 0.05) in all subjects. Neither the baseline plasma levels nor the baseline CSF levels of NPY were different between normal weight subjects and obese subjects. After weight loss, the CSF NPY level decreased significantly compared with baseline values in obese subjects. The alpha-MSH levels in plasma and CSF did not differ significantly from controls in obese subjects at baseline or after weight loss. Baseline CSF leptin level correlated with neither the baseline CSF NPY level nor the baseline CSF alpha-MSH level. In conclusion, this study demonstrated that the efficiency of brain leptin delivery is reduced in human obesity and central nervous system leptin uptake involves a combination of a saturable and an unsaturable mechanism. CSF NPY and alpha-MSH did not differ from controls in human obesity, and the CSF NPY level decreased significantly whereas alpha-MSH did not differ after weight loss in obese subjects compared with baseline. There was no significant correlation between CSF leptin and CSF NPY or alpha-MSH. This could be the result of leptin resistance present in human obesity and/or the more complex mechanisms involved in modulating appetite and regulating energy balance in human obesity.