Two-year evolution of quality of life following radiotherapy and/or chemotherapy in patients with head and neck cancer

Objective

This study aims to elucidate the trajectory of quality of life (QoL) over a two-year period after radiotherapy and/or chemotherapy for head and neck cancer (HNC), addressing the gap in long-term QoL information.

Methods

Employing a prospective longitudinal observational design, we tracked 58 HNC patients who underwent radiotherapy and/or chemotherapy, analyzing their QoL using Short-Form 36-Item Health Survey version 2 (SF36v2), the European Organization for Research and Treatment of Cancer quality of life (EORTC-QLQ-C30), and the European Organization for Research and Treatment of Cancer quality of life head and neck-35 (EORTC-QLQ-H&N35) questionnaires for two years post-discharge. The data underwent repeated measures analysis of variance.

Results

Over the two-year follow-up, 10 patients (17.2%) succumbed, and 8 (13.8%) dropped out. SF36v2 physical and role-social component summary scores declined during treatment, requiring 1-2 years for recovery. The mental component summary score remained stable. EORTC-QLQ-30 revealed global health status recovery within one year post-discharge. EORTC-QLQ-H&N35 items like "swallowing," "senses problems," "trouble with social eating," "dry mouth," "sticky saliva," "coughing," and "felt ill" worsened pre-discharge. "Trouble with social contact" improved within a year, while "pain," "swallowing," "senses problems," "trouble with social eating," and "coughing" improved within two years. "Dry mouth" and "sticky saliva" persisted throughout the two-year follow-up, common symptoms of HNC and treatment side effects.

Conclusions

Recovery of specific QoL aspects in HNC patients treated with radiotherapy and/or chemotherapy may require up to two years. Prolonged monitoring and management of oral symptoms could enhance QoL. Future research should extend follow-up beyond two years for comprehensive interventions enhancing patient QoL.

Clinicopathological findings, prognosis, and Epstein-Barr virus infection in rheumatoid arthritis patients with other iatrogenic immunodeficiency-associated T- and NK-cell lymphoproliferative disorders

BACKGROUND

Other iatrogenic immunodeficiency-associated (OIIA) T- and natural killer (NK)-cell lymphoproliferative disorders (TNK-LPDs) are rare in patients with rheumatoid arthritis (RA).

METHODS

We investigated the clinicopathological characteristics, Epstein-Barr virus (EBV) infection, genetic findings, therapeutic response, and prognostic factors in 21 RA patients with OIIA TNK-LPDs and compared these with those of 39 with OIIA B-cell LPDs (B-LPDs) and 22 with non-OIIA B-LPDs.

RESULTS

Immunohistologically, 11 patients (52%) showed CD4+ T-LPDs, and 7 had a T follicular helper (TFH) phenotype. The other nine patients (43%) showed CD8+ T-LPDs, and the remaining one (5%) had features of CD3+ CD4- CD8- nasal type TNK-cell lymphoma. CD30+, p53+, and CMYC+ atypical lymphocytes were identified in seven (33%), eight (38%), and five (24%) patients, respectively. In situ hybridisation detected EBV-encoded RNA (EBER) + large atypical lymphocytes in five patients (24%). Nine of 17 patients (53%) showed clonal peaks of TCRγ by polymerase chain reaction. Withdrawal of MTX and biologic drugs was effective in 12 patients (57%), and 8 (38%) received chemotherapies. Two patients with TFH+ or EBV+ CD4+ CD30+ large cell peripheral T-cell lymphoma, one with CD8+ systemic anaplastic large cell lymphoma, and two with systemic EBV+ CD8+ T-cell lymphoma of childhood showed a lethal progressive clinical course within 13 months. Moreover, > 500 U/L LDH, large atypical lymphocytes, expression of CD30, p53, and CMYC, and EBER+ atypical lymphocytes were significantly poor prognostic factors for overall survival (p < 0.05). Median interval from RA onset to OIIA TNK-LPDs was 72 months, which was shorter than 166 months in OIIA B-LPDs (p = 0.003). EBV+ atypical and reactive lymphocytes were frequently found in 15 patients with OIIA TNK-LPDs (71%), in 27 with OIIA B-LPDs (69%), and only in 3 with non-OIIA B-LPDs (14%).

CONCLUSIONS

OIIA TNK-LPDs occurred in early phase of RA, compared with OIIA B-LPDs, and occasionally showed a lethal progressive clinical course. Detection of OIIA TNK-LPD patients with poor prognostic factors is necessary. EBV infection in immunosuppressed patients due to persistent RA, MTX, and biologic drugs may play a role in forming the tumour microenvironment and lymphomagenesis of TNK-LPDs.

Resolution of Laryngeal Ulceration with Prednisolone Therapy in a Patient with Crohn's Disease

A 23-year-old man diagnosed with Crohn's disease (CD) was treated with infliximab. He developed new-onset sore throat and dysphagia during admission, and nasopharyngoscopy revealed epiglottic ulceration. Laryngeal ulceration was considered as an extraintestinal manifestation of CD owing to treatment failure with antibiotics and hydrocortisone. This strongly suggested that laryngeal ulceration was a complication of CD because of the rapid improvement in the symptoms and lesions after prednisolone administration. Furthermore, this treatment process demonstrated the superior anti-inflammatory effect of prednisolone over that of hydrocortisone and supported the assumption of inflammation related to CD.

A Rare Case of Tracheal Crystal-Storing Histiocytosis Associated with Marginal Zone Lymphoma of Mucosa-Associated Lymphoid Tissue

Crystal-storing histiocytosis (CSH) is a rare non-neoplastic histiocytic lesion with abnormal accumulation of immunoglobulin (Ig) light chain. CSH is associated with Ig overproduction by B-lymphoproliferative disorders (B-LPDs) or by persistent inflammatory diseases. Eighteen cases of pulmonary CSH have been reported. However, no case reports of tracheal CSH have been published. In this patient, we found a solitary tracheal tumor in an asymptomatic 60-year-old man on chest computed tomography scan. Histologically, the tumor comprised two different lesions. One lesion showed diffuse proliferation of spindle-shaped histiocytes with abundant eosinophilic granular cytoplasm. With immunohistochemistry, the histiocytic cells were positive for CD68, CD163 and Ig kappa light chain, and the cytoplasm was weakly positive for anaplastic lymphoma kinase (ALK) protein. Fluorescence in situ hybridization indicated no split signals for the ALK gene. Electron microscopy demonstrated many elongated or rhomboid-shaped dense crystals in the cytoplasm of histiocytes. The second lesion showed proliferation of CD20-positive small atypical lymphocytes mixed with Ig kappa chain-positive plasma cells. A diagnosis of CSH and concomitant mucosa-associated lymphoid tissue lymphoma was made. In this patient, unexpected ALK protein was detected in infiltrating histiocytes. Therefore, careful assessment of the ALK protein and gene was necessary to differentiate from other histiocytic disorders.

Programmed cell death-ligand 1 (PD-L1)+ tumour cells and low-reacting programmed cell death 1 (PD1)+ tumour-infiltrating lymphocytes predict poor prognosis in Epstein-Barr virus+ diffuse large B-cell lymphoma

Epstein-Barr virus (EBV)⁺ diffuse large B-cell lymphoma (DLBCL) has specific tumour cell characteristics, and these patients have worse outcomes than EBV-negative DLBCL patients. We compared 38 EBV⁺ DLBCL patients with 43 methotrexate-associated EBV⁺ B-cell lymphoproliferative disorders (MTX⁺/EBV⁺ BLPDs) and 30 non-germinal centre (GC) subtype DLBCL. Lymphoma cells of the EBV⁺ DLBCL group were positive for BCL2 in 17 patients (44.7%), CMYC in 23 patients (60.5%), and p53 in 33 patients (86.8%), which was significantly higher than in the MTX⁺/EBV⁺ BLPD group (P < 0.05), and were positive for CD30 in 29 patients (76.3%), compared with two in non-GC subtype DLBCL (6.7%) (P < 0.0001). Significantly more EBV⁺ DLBCL patients (n = 16, 42.1%) had programmed cell death-ligand 1 (PD-L1)⁺ tumour cells than patients with non-GC subtype DLBCL (n = 5, 16.7%; P = 0.024), and PD-L1⁺ tumour cells were more common in advanced stages than in early stages (P = 0.048). Twenty-five EBV⁺ DLBCL patients (69.4%) had few reactive PD1⁺ tumour-infiltrating lymphocytes (TILs), compared with 12 patients with MTX⁺/EBV⁺ BLPDs (37.5%) (P = 0.008). In the EBV⁺ DLBCL group, CD30, BCL2, CMYC, and p53 expression was not related to patient prognosis. Poor outcomes were associated with PD-L1⁺ tumour cells (P = 0.001) and low-reacting PD1⁺ TILs (P = 0.02), while their combination conferred a worse outcome (P < 0.0001). Immune evasion by PD-L1⁺ tumour cells and exhaustion of PD1⁺ TILs may occur in EBV⁺ DLBCL patients, and PD-L1/PD1 interactions may influence tumour progression and poor prognosis.

Management of tracheostomy in COVID-19 patients: The Japanese experience

Objective

Involvement in the tracheostomy procedure for COVID-19 patients can lead to a feeling of fear in medical staff. To address concerns over infection, we gathered and analyzed experiences with tracheostomy in the COVID-19 patient population from all over Japan.

Methods

The data for health-care workers involved in tracheostomies for COVID-19-infected patients were gathered from academic medical centers or their affiliated hospitals from all over Japan.

Results

Tracheostomies have been performed in 35 COVID-19 patients with a total of 91 surgeons, 49 anesthesiologists, and 49 surgical staff members involved. Twenty-eight (80%) patients underwent surgery more than 22 days after the development of COVID-19-related symptoms (11: 22–28 days and 17: ≥29 days). Thirty (85.7%) patients underwent surgery ≥ 15 days after intubation (14: 15–21 days, 6: 22–28 days, and 10: ≥29 days). Among the total of 189 health-care workers involved in the tracheostomy procedures, 25 used a powered air-purifying respirator (PAPR) and 164 used a N95 mask and eye protection. As a result, no transmission to staff occurred during the 2 weeks of follow-up after surgery.

Conclusion

No one involved in tracheostomy procedures were found to have been infected with COVID-19 in this Japanese study. The reason is thought to be that the timing of the surgery was quite late after the infections, and the surgery was performed using appropriate PPE and surgical procedure. The indications for and timing of tracheostomy for severe COVID-19 patients should be decided through multidisciplinary discussion.

Mutant KRAS Promotes NKG2D+ T Cell Infiltration and CD155 Dependent Immune Evasion

BACKGROUND/AIM

Roles for mutant (mt) KRAS in the innate immune microenvironment in colorectal cancer (CRC) were explored.

MATERIALS AND METHODS

Human CRC HCT116-derived, mtKRAS-disrupted (HKe3) cells that express exogenous mtKRAS and allogenic cytokine-activated killer (CAK) cells were co-cultured in 3D floating (3DF) culture. The anti-CD155 antibody was used for function blocking and immuno histochemistry.

RESULTS

Infiltration of CAK cells, including NKG2D⁺ T cells, into the deep layer of HKe3-mtKRAS spheroids, was observed. Surface expression of CD155 was found to be up-regulated by mtKRAS in 3DF culture and CRC tissues. Further, the number of CD3⁺ tumor-infiltrating cells in the invasion front that show substantial CD155 expression was significantly larger than the number showing weak expression in CRC tissues with mtKRAS. CD155 blockade decreased the growth of spheroids directly and indirectly through the release of CAK cells.

CONCLUSION

CD155 blockade may be useful for therapies targeting tumors containing mtKRAS.

MK615 Suppresses Hypoxia Tolerance by Up-regulation of E-cadherin in Colorectal Cancer Cells With Mutant KRAS

BACKGROUND/AIM

The Japanese apricot "Prunus mume" is a traditional Japanese medicine. MK615, a compound extract from Prunus mume has been reported to have anti-tumor effects. Herein, we used 3D floating (3DF) culture to evaluate the anticancer effects of MK615 against human colorectal cancer (CRC) cells that contain mutant (mt) KRAS.

MATERIALS AND METHODS

HKe3 cells exogenously expressing mtKRAS (HKe3-mtKRAS) were treated with MK615 in 3DF cultures. The protein levels of hypoxia-inducible factor 1 (HIF-1) and E-cadherin were quantified by western blotting.

RESULTS

MtKRAS enhanced hypoxia tolerance via up-regulation of HIF-1. The expression of HIF-1 protein was suppressed by constitutive overexpression of E-cadherin in CRC HCT116 spheroids. MK615 increased the expression of E-cadherin and decreased the expression of HIF-1 in HKe3-mtKRAS. These results suggest that MK615 suppresses hypoxia tolerance by up-regulation of E-cadherin in CRC cells with mtKRAS.

CONCLUSION

MK615 exhibits properties useful for the potential treatment of CRC patients with mtKRAS.

Highly expressed tumoral emmprin and stromal CD73 predict a poor prognosis for external auditory canal carcinoma

Squamous cell carcinoma of the external auditory canal (SCC-EAC) is rare and has a poor prognosis. The SCC-EAC cases with high-grade tumor budding (TB) or poorly differentiated clusters (PDCs) are associated with shorter survival than those with low-grade TB or PDCs. Extracellular matrix metalloproteinase inducer (emmprin) is a protein expressed in tumor cells that stimulates the production of MMP-2 by stromal fibroblasts to facilitate tumor invasion. Recently, we reported that emmprin forms a complex with CD73 to regulate MMP-2 production from fibroblasts in vitro. Here, we examined the association of emmprin and CD73 expression with TB or PDCs as well as with survival in 34 biopsy specimens of SCC-EAC patients. High tumoral emmprin expression was associated with high-grade TB, whereas high stromal CD73 expression was associated with high-grade PDCs. Furthermore, concurrent elevated expression of tumoral emmprin and stromal CD73 was determined to be an independent poor prognostic factor. In immunoprecipitation analyses, complex formation between emmprin and CD73 was demonstrated in vitro. Production of MMP-2 from fibroblasts was more abundant when cocultured with tumor cells than from fibroblasts cultured alone. Furthermore, MMP-2 production was reduced by the transfection of CD73 siRNA in fibroblasts cocultured with tumor cells. The colocalization of emmprin and CD73 was enhanced in not only the peripheral cells of the tumor cell clusters that interact with fibroblasts but also in the cells of intratumor clusters. Overall, this study provides novel insights into the roles of emmprin, CD73, and MMP-2 in tumor invasiveness.

A Case of Salivary Duct Carcinoma Intracranial Invasion due to Perineural Invasion Through the Facial Nerve

BACKGROUND

Salivary duct carcinoma (SDC) is a rare parotid tumor that often develops as a rapidly growing mass with a poor prognosis. It has a high rate of distant metastases, sometimes with infiltration along nerves. We describe a case of SDC that originated outside the cranium and extended into the cranium along the path of the facial nerve.

CASE DESCRIPTION

A 74-year-old man underwent magnetic resonance imaging at a local hospital, which revealed a tumor in the left internal acoustic canal; the patient was referred to our department. A left facial schwannoma was suspected, and magnetic resonance imaging was performed again 6 months later. Rapid tumor growth was confirmed, and the tumor was resected. The tumor displayed atypical epithelial cells with comedo necrosis and cribriform structure and was diagnosed as SDC. All residual intracranial tumors were removed using the middle fossa approach. The tumor, which was considered to be a primary tumor, was found near the stylomastoid foramen, and it was removed with the parotid gland. Five months after the initial surgery, metastasis to the trigeminal nerve was observed, and this was removed using a retrosigmoid approach, followed by radiation therapy.

CONCLUSIONS

All 4 surgical specimens of this case were presented, and the path of tumor progression was examined in detail. Although the primary lesion was small, intracranial invasion along the facial nerve occurred. SDC should be considered as a tumor that can extend into the cranium, even with a small primary lesion.

P6332Prevalence and prognostic impact of sarcopenia identified according to Asia Working Group for Sarcopenia definition in non-dependent elderly patients with heart failure

Background

Sarcopenia is a geriatric syndrome characterized by loss of muscle mass and muscle function. As the population ages, there is a growing worldwide interest in the intersection of sarcopenia and heart failure (HF). However, estimates of the prevalence of sarcopenia in HF vary widely because of difference in diagnostic criteria. Although the Asian Working Group of Sarcopenia (AWGS) has announced a consensus on the diagnostic criteria of sarcopenia in Asian people, the prevalence and prognostic impact of sarcopenia based on AWGS criteria in patients with HF remains unclear.

Purpose

The aim of this study was to investigate the prevalence and predictive value of sarcopenia identified according to AWGS definition in non-dependent elderly patients with HF.

Methods

This study was a prospective, single-center cohort study in Japan. We consecutively enrolled 274 patients, aged 65 years or older, hospitalized due to acute HF or acute exacerbation of chronic HF and who were able to walk at least 20 m at discharge. Patients with severe cognitive or psychiatric disorders were excluded. Patients with implantable cardiac pacemaker or cardioverter defibrillator were also excluded because skeletal muscle mass was estimated by using bioimpedance analysis. At hospital discharge, we collected data on age, gender, left ventricular ejection fraction, brain natriuretic peptide, estimate glomerular filtration rate, body mass index and sarcopenia. Sarcopenia was diagnosed according to the AWGS criteria: low skeletal muscle index (<7.0 kg/m2 in men, <5.7 kg/m2 in women) and either slow usual walking speed (<0.8 m/s) or low handgrip strength (<26 kg in men, <17 kg in women). Study outcome was rehospitalization for worsening HF within 180 days after discharge. We assessed the independent association between sarcopenia and HF rehospitalization by using multivariate Cox proportional hazards regression analysis.

Results

In this study, a total of 199 patents (43.4%) fulfilled sarcopenia criteria at discharge. During follow-up, 57 patients (20.8%) readmitted for HF. Kaplan-Meier survival curves showed that patients with sarcopenia had significantly lower event-free survival than those without sarcopenia (Figure). After adjusting for other prognostic factors, sarcopenia was independently associated with HF rehospitalization (hazard ratio: 2.31, 95% confidence interval: 1.20–4.53).

Conclusion

Based on AWGS criteria, sarcopenia is highly prevalent even among non-dependent elderly HF patients, and is an independent strong predictor of rehospitalization for worsening HF. AWGS criteria for sarcopenia may be useful for risk prediction in HF.

Adenoid cystic carcinoma with high-grade transformation forming spindle cell component of the submandibular gland

Adenoid cystic carcinoma (AdCC) with high-grade transformation (AdCC-HGT) is rare, and AdCC-HGT with spindle cell component is particularly rare. The patient was a 65-year-old man with a 5 cm sized swelling of the right submandibular gland. Submandibular sialoadenectomy was performed. Histopathological findings mainly showed conventional AdCC, and minorly showed two other components: (1) the pleomorphic component, a proliferation of atypical pleomorphic epithelial cells forming solid or small clusters and accompanied by necrosis; (2) the spindle cell component, containing atypical spindle cells invading the stroma. Postoperative chemoradiotherapy was performed. Multiple right lung nodular lesions were found on the contrast-enhanced chest CT one month after the surgery. Thoracoscopic pulmonary resection was performed. The lung tumors exhibited a proliferation of atypical spindle cells, accompanied by necrosis. We considered that the spindle cell component of the AdCC-HGT of the submandibular gland developed lung metastases. The patient died seven months after submandibular sialoadenectomy due to respiratory failure. Although rare, our case highlights the importance of recognising spindle cell components in conventional AdCC; even if the area is small, these high-grade transformation areas can metastasise and become prognostic factors.

Poorly Differentiated Clusters Predict a Poor Prognosis for External Auditory Canal Carcinoma

Squamous cell carcinoma (SCC) of the external auditory canal (EAC) is rare and offers a poor prognosis; more accurate prognostic biomarkers are required. Our laboratory recently demonstrated that tumor budding, characterized by tumor cell clusters (< 5 cells), and laminin 5-γ2 staining of SCC of the EAC are associated with shorter survival. However, clusters composed of ≥ 5 tumor cells are also found in the stroma. Previous reports of colorectal cancer suggest that poorly differentiated clusters (PDCs) are a negative prognostic indicator. Here, we report on the association between PDCs and prognosis in SCC of the EAC. PDCs and tumor budding were histopathologically and immunohistochemically (cytokeratin AE1/AE3) analyzed in 31 cases of pre-treatment biopsy SCC of the EAC. Clusters in the stroma composed of < or ≥ 5 cancer cells were defined as tumor budding or PDCs, respectively. Entire tumors were initially scanned to identify greatest PDC density. Tumors with low or high PDC density were classified as low- and high-grade, respectively. Patients with high-grade PDCs had a significantly poorer outcome than those with low-grade. Even in cases of low-grade tumor budding, those with high-grade PDCs had a poor prognosis. Multivariate analysis results indicated that high-grade PDCs were associated with poor prognosis. PDC grade can provide a more accurate prognosis than tumor budding in SCC of the EAC.

Molecular dynamics simulation of potentiometric sensor response: the effect of biomolecules, surface morphology and surface charge

The silica-water interface is critical to many modern technologies in chemical engineering and biosensing. One technology used commonly in biosensors, the potentiometric sensor, operates by measuring the changes in electric potential due to changes in the interfacial electric field. Predictive modelling of this response caused by surface binding of biomolecules remains highly challenging. In this work, through the most extensive molecular dynamics simulation of the silica-water interfacial potential and electric field to date, we report a novel prediction and explanation of the effects of nano-morphology on sensor response. Amorphous silica demonstrated a larger potentiometric response than an equivalent crystalline silica model due to increased sodium adsorption, in agreement with experiments showing improved sensor response with nano-texturing. We provide proof-of-concept that molecular dynamics can be used as a complementary tool for potentiometric biosensor response prediction. Effects that are conventionally neglected, such as surface morphology, water polarisation, biomolecule dynamics and finite-size effects, are explicitly modelled.

Changes in Coagulation Factors by Passage through a Dextran Sulfate Cellulose Column during Low-Density Lipoprotein Apheresis

To determine the extent of adsorption of coagulation factors by a dextran sulfate cellulose column used for selective removal of low-density lipoprotein (LDL), various coagulation factors were measured before and after application to the column during LDL apheresis. The column almost completely adsorbed many coagulation factors. Although the bradykinin concentration was markedly increased by passing the plasma through the column, this increment was suppressed by nafamostat mesilate which inhibits the initial contact phase of the intrinsic coagulation pathway. The von Willebrand factor, which forms a complex with factor VIII in plasma, is reduced in apheresis with nafamostat mesilate to the same extent as in apheresis without nafamostat mesilate. Thus, coagulation factors seem to be adsorbed by different mechanisms which include activation of the initial contact phase by the negative charges of dextran sulfate and concomitant adsorption with the phospholipid portion of lipoproteins containing apolipoprotein B or with von Willebrand factor.

Observations of cavity polaritons in one-dimensional photonic crystals containing a liquid-crystalline semiconductor based on perylene bisimide units

We investigated the optical transmission properties of one-dimensional photonic crystal (1D-PC) microcavity structures containing the liquid-crystalline (LC) perylene tetracarboxylic bisimide (PTCBI) derivative. We fabricated the microcavity structures for this study by two different methods and observed the cavity polaritons successfully in both samples. For one sample, since the PTCBI molecules were aligned in the cavity layer of the 1D-PC by utilizing a friction transfer method, vacuum Rabi splitting energy was strongly dependent on the polarization of the incident light produced by the peculiar optical features of the LC organic semiconductor. For the other sample, we did not utilize the friction transfer method and did not observe such polarization dependence. However, we did observe a relatively large Rabi splitting energy of 187 meV, probably due to the improvement of optical confinement effect.

ROS-induced cleavage of NHLRC2 by caspase-8 leads to apoptotic cell death in the HCT116 human colon cancer cell line

Excess production of reactive oxygen species (ROS) is known to cause apoptotic cell death. However, the molecular mechanisms whereby ROS induce apoptosis remain elusive. Here we show that the NHL-repeat-containing protein 2 (NHLRC2) thioredoxin-like domain protein is cleaved by caspase-8 in ROS-induced apoptosis in the HCT116 human colon cancer cell line. Treatment of HCT116 cells with the oxidant tert-butyl hydroperoxide (tBHP) induced apoptosis and reduced NHLRC2 protein levels, whereas pretreatment with the antioxidant N-acetyl-l-cysteine prevented apoptosis and the decrease in NHLRC2 protein levels seen in tBHP-treated cells. Furthermore, the ROS-induced decrease in NHLRC2 protein levels was relieved by the caspase inhibitor z-VAD-fmk. We found that the thioredoxin-like domain of NHLRC2 interacted with a proenzyme form of caspase-8, and that caspase-8 cleaved NHLRC2 protein at Asp580 in vitro. Furthermore, siRNA-mediated knockdown of caspase-8 blocked the ROS-induced decrease in NHLRC2 protein levels. Both shRNA and CRISPR-Cas9-mediated loss of NHLRC2 resulted in an increased susceptibility of HCT116 cells to ROS-induced apoptosis. These results suggest that excess ROS production causes a caspase-8-mediated decrease in NHLRC2 protein levels, leading to apoptotic cell death in colon cancer cells, and indicate an important role of NHLRC2 in the regulation of ROS-induced apoptosis.

Apremilast Induces Apoptosis of Human Colorectal Cancer Cells with Mutant KRAS

BACKGROUND/AIM

We previously reported the crucial roles of oncogenic Kirsten rat sarcoma viral oncogene homologue (KRAS) in inhibiting apoptosis and disrupting cell polarity via the regulation of phosphodiesterase type 4B2 (PDE4B2) expression in human colorectal cancer (CRC) HCT116 cells in a three-dimensional culture (3DC). Here, we evaluated the effects of apremilast, a selective PDE4 inhibitor, on luminal apoptosis in 3DC and nude mice assay using HKe3 human CRC cells stably expressing wild-type (wt)PDE4B2 (HKe3-wtPDE4B2), mutant (mt)PDE4B2 (kinase dead) (HKe3-wtKRAS), wtKRAS (HKe3-wtKRAS) and mtKRAS (HKe3-mtKRAS).

MATERIALS AND METHODS

Apoptosis was detected by immunofluorescence using confocal laser scanning microscopy or western blot in HKe3-wtPDE4B2, HKe3-mtPDE4B2, HKe3-wtKRAS and mtKRAS cells treated with or without apremilast in 3DC. Tumourigenicity was assessed in nude mice assay using these cells.

RESULTS

Apremilast did not inhibit the proliferation of HKe3-wtPDE4B2 cells or HKe3-mtKRAS in two-dimensional cultures, whereas the number of apoptotic HKe3-wtPDE4B2 cells and HKe3-mtKRAS cells increased after apremilast treatment in 3DC, leading to formation of a luminal cavity. Tumour growth in nude mice was dramatically reduced by intraperitoneal injection of apremilast. Notably, a decreased level of caspase-1 expression was observed in HKe3-wtPDE4B2 and HKe3-mtKRAS cells.

CONCLUSION

Apremilast induces tumour regression in nude mice, possibly by inducing caspase-1 expression.

A rare case of dedifferentiated liposarcoma of the sinonasal cavity: A case report

Sarcoma is an uncommon histopathological presentation of sinonasal tumors, comprising ~15% of all cases; liposarcoma is particularly uncommon. An analysis of the available medical literature revealed no prior reports of dedifferentiated liposarcoma (DDLPS) of the sinonasal cavity. This case report presents a rare case of DDLPS of the sinonasal cavity. A 40-year old six-week pregnant female was admitted with a left nasal obstruction. Endoscopic evaluation of the left nasal cavity revealed a polypoid lesion. A computed tomography scan indicated a mass invading the left nasal cavity, maxillary sinus and anterior ethmoid sinus with focal destruction of the surrounding bone. A biopsy of the tumor was performed and hematoxylin and eosin staining of the tissue sections revealed proliferation of atypical and pleomorphic spindle cells with enlarged or elongated hyperchromatic nuclei and occasional vacuolated cytoplasm arranged in short interlacing fascicles or storiform structures, accompanied by tumor necrosis. These findings were consistent with undifferentiated pleomorphic sarcoma. Immunohistochemically, the tumor cells were positive for cyclin dependent kinase 4, mouse double minute 2 homolog (MDM2) and adipophilin. Fluorescence in situ hybridization (FISH) analysis revealed amplification of the MDM2 gene. Recently, undifferentiated pleomorphic sarcoma without areas of well-differentiated liposarcoma but with MDM2 amplification is regarded as conventional DDLPS. In the present case, the tumor was diagnosed as a DDLPS due to the results of histopathological, immunohistochemical and FISH analysis.

An Alpha-kinase 2 Gene Variant Disrupts Filamentous Actin Localization in the Surface Cells of Colorectal Cancer Spheroids

BACKGROUND/AIM

Alpha-kinase 2 (ALPK2), suggested to be a novel tumour-suppressor gene down-regulated by oncogenic KRAS, plays a pivotal role in luminal apoptosis in normal colonic crypts. The aim of this study was to determine the association between ALPK2 germline variants and colorectal cancer.

MATERIALS AND METHODS

Missense single nucleotide variants in the exons of the ALPK2 gene in 2,343 consecutive autopsy cases (1,446 cases with cancer and 897 cases without cancer) were screened using HumanExome BeadChip arrays. To address the functional effect of a missense ALPK2 variant, a 3D floating cell culture was performed using HCT116-derived human colorectal cancer cells stably expressing wild-type (wt) ALPK2 (HCT116-wtALPK2) or amino acid-substituted (sub) ALPK2 (HCT116-subALPK2).

RESULTS

We identified that one of the ALPK2 germline variants, rs55674018 (p.Q1853E), was significantly associated with the presence of cancer (adjusted odds ratio(OR)=4.39; 95% confidence interval(CI)=1.31-14.78, p=0.001). The p.Q1853E variant was present in the East Asian population and located in the immunoglobulin-like domain. Notably, the basolateral polarity of actin in the surface of HCT116-wtALPK2 spheroids was more attenuated compared to that of HCT116-subALPK2 spheroids. Furthermore, luminal apoptosis and cell aggregation were promoted by wtALPK2, but not by subALPK2 in 3D culture.

CONCLUSION

The p.Q1853E variant of ALPK2, which had been accumulating in the Japanese population, induced a metastatic phenotype by disrupting ALPK2 function.

Dynamic behaviour of the silica-water-bio electrical double layer in the presence of a divalent electrolyte

Molecular dynamics simulation of the electric double layer at the silica-water-bio interface in mixed electrolyte. Water orientation and charge distribution showed a significant effect on the electrostatics at the interface.

Two-layer anti-reflection coating with mullite and polyimide foam for large-diameter cryogenic infrared filters

We have developed a novel two-layer anti-reflection (AR) coating method for large-diameter infrared (IR) filters made of alumina, for use at cryogenic temperatures in millimeter wave measurements. Thermally sprayed mullite and polyimide foam (Skybond Foam) are used as the AR material. An advantage of the Skybond Foam is that the index of refraction is chosen between 1.1 and 1.7 by changing the filling factor. Combination with mullite is suitable for wide-band millimeter wave measurements with sufficient IR cutoff capability. We present the material properties, fabrication of a large-diameter IR filter made of alumina with this AR coating method, and characterizations at cryogenic temperatures. This technology can be applied to a low-temperature receiver system with a large-diameter focal plane for next-generation cosmic microwave background polarization measurements, such as POLARBEAR-2 (PB-2).

High-pressure liquid chromatography of free nucleotide patterns in normal and abnormal keratinocytes

A method for analyzing free nucleotides in the epidermis of the guinea pig is presented. Free nucleotides were extracted by using a methylalethanol mixture, and the analysis was carried out by high-pressure liquid chromatography on a column of Lichrosorb-NH2 with a single buffer of potassium phosphate. The concentration of total free nucleotides in the epidermis is about 4 times greater than that in the liver, kidney, spleen, or intestinal epithelium.l The free nucleotide level is markedly elevated in the hyperkeratotic epidermis induced by n-hexadecane. The alternation of free nucleotides in hyperkeratotic epidermis is discussed in relation to nucleic acid content, DNase, disc-electrophoretic properties of DNase, and salvage pathway enzymatic activity. Significant increases in the enzyme activity of the salvage pathway and in neutral DNase were observed in the hyperkeratotic stage. However, the DNA content and acid DNase activity were decreased. It is suggested that the pool size of free nucleotides in the epidermis is affected by the salvage enzyme system.

Hypothalamic brain-derived neurotrophic factor regulates glucagon secretion mediated by pancreatic efferent nerves

Understanding the molecular mechanism of the regulation of glucagon secretion is critical for treating the dysfunction of α cells observed in diabetes. Glucagon-like peptide (GLP)-1 analogues reduce plasma glucagon and are assumed to contribute to their action to lower blood glucose. It has previously been demonstrated that the central administration of brain-derived neurotrophic factor (BDNF) improves glucose metabolism by a mechanism independent of feeding behaviour in obese subjects. Using male rats, we examined whether BDNF influences glucagon secretion from α cells via the the central nervous system. We investigate whether: (i) the central infusion of BDNF stimulates glucagon and/or insulin secretion via the pancreatic efferent nerve from the hypothalamus; (ii) the intraportal infusion of GLP-1 regulates glucose metabolism via the central and peripheral nervous system; and (iii) BDNF receptor and/or BDNF-positive fibres are localised near α cells of islets. The portal glucagon level decreased with the central administration of BDNF (n = 6, in each; P < 0.05); in contrast, there was no significant change in portal insulin, peripheral glucagon and insulin levels with the same treatment. This reduction of glucagon secretion was abolished by pancreatic efferent denervation (n = 6, in each; P < 0.05). In an immunohistochemical study, pancreatic α cells were stained specifically with BDNF and tyrosine-related kinase B, a specific receptor for BDNF, and α cells were also co-localised with BDNF. Moreover, intraportal administration of GLP-1 decreased glucagon secretion, as well as blood glucose, whereas it increased the BDNF content in the pancreas; these effects were inhibited with the central infusion of BDNF antibody (n = 6, in each; P < 0.05). BDNF and GLP-1 affect glucose metabolism and modulate glucagon secretion from pancreatic α cells via the central and peripheral nervous systems.

Modulation of somatosensory abilities and the feeling of ear fullness in patients with acute sensorineural hearing loss

OBJECTIVE

Patients with acute sensorineural hearing loss (ASNHL) often complain of a feeling of ear fullness (FEF) that is similar to the sensation experienced during barometric pressure changes. This suggests that modulation of somatosensory abilities may relate to the manifestation of FEF, whereas it cannot simply be assumed that somatosensory abilities would be directly affected by ASNHL. To examine this possible relationship, we estimated somatosensory abilities of the tympanic membrane, and investigated the relationship between them and the manifestation of FEF.

METHODS

To estimate somatosensory abilities of the tympanic membrane, 83 new patients demonstrating unilateral sudden deafness were studied. The air pressure was loaded through an exclusive device on the external auditory canals in order to measure the minimum change in air pressure sensed by the subjects. The minimum pressure was defined as the minimum sensory threshold for air pressure loading (MSTAP; daPa). We estimated patient's somatosensory abilities and inquired about their experiences with FEF at the first medical examination (point 1) and at the time a steady audiogram was obtained (point 2). We also estimated MSTAP in 65 volunteers (130 ears) with no history of ear diseases and compared their MSTAP with that of sudden deafness patients.

RESULTS

MSTAP values (-64.0±32.2daPa, 60.5±26.0daPa) on the affected side with both negative pressure and positive pressure measured at point 1 were significantly higher than those (-40.7±15.0daPa, 40.0±12.7daPa) obtained at point 2 in all sudden deafness patients (p=0.0001, p=0.0001). There was no difference between MSTAP values (-39.6±10.7daPa, 39.9±11.4daPa) in normal subjects and those obtained at point 2 in all sudden deafness patients. On the other hand, significant differences of MSTAP with negative pressures between the affected and unaffected sides at point 1 were seen in 32 patients, and manifestation of FEF showed an insignificant association in these 32 patients (p<0.05).

CONCLUSION

Modulation of somatosensory abilities in ASNHL seemed to be the best possible explanation for results, suggesting that a rise in MSTAP may somehow be associated with FEF. Although it cannot be verified by result of the current study, consideration of the previous literature suggests that the phenomenon may be caused by cross-modality of hearing and somatosensory abilities.

Advantage of early induction of opioid to control pain induced by irradiation in head and neck cancer patients

OBJECTIVE

Although radiotherapy is effective for head and neck cancer patients, the local pain evoked by the irradiation itself reduces food intake and frequently halts the treatment. Thus, pain control is an important problem in radiotherapy for head and neck cancer. We performed to examine whether early induction of low-dose, opioid from mild pain improves dietary and caloric intake, while reducing weight loss.

METHODS

The subjects were 43 patients who were hospitalized for head and neck cancer from 2004 to 2008. They were patients who underwent radiation treatment but those who did not undergo preoperative treatment. They were divided into two groups, depending on whether the pain was mild or moderate when an opioid was introduced (MILD and MODERATE, N=23 and 20, respectively).

RESULTS

The visual analog scale scores for pain were significantly lower in the MILD than in the MODERATE group at between 25 and 50 Gy. The amount of oxycodone used for pain was significantly lower in the MILD than the MODERATE group. A regular diet was maintained for significantly longer in the MILD group. Caloric intake was significantly higher in the MILD group at over 20 Gy. Weight loss was significantly lower in the MILD group at over 20 Gy. The incidence of side effects was equal in both groups.

CONCLUSION

Our results indicated that the introduction of opioids for mild pain during radiotherapy controls the level of pain, improving food intake in head and neck cancer patients.

Acute idiopathic sensorineural hearing impairment at frequency exceeding 8 kHz

CONCLUSIONS

Acute idiopathic sensorineural hearing impairment at a frequency exceeding 8 kHz (high-frequency range) was recognized in patients suffering from acute tinnitus without hearing loss. The cases in this study may contribute to clarifying the pathogenesis of tinnitus without hearing loss and evaluating its response to steroid therapy.

OBJECTIVES

The aim of this study was to demonstrate the existence of acute idiopathic sensorineural hearing impairment only in the high-frequency range and to investigate its relation to tinnitus without hearing loss.

METHODS

Five patients aged 29 years or younger who consulted a hospital within a few days after the onset of unilateral tinnitus without hearing loss were studied. We conducted audiometry involving the high-frequency range on first medical examination and on improvement in tinnitus, and investigated the association between the hearing findings in the high-frequency range and a tinnitus prognosis.

RESULTS

All five patients showed abnormalities in the threshold in the high-frequency range on the affected side. In the three cases given prednisolone, tinnitus and the threshold abnormalities were reduced within 20 days. In contrast, tinnitus and the threshold abnormalities showed little change in two patients who were not treated.

Modification of carcinogenesis by antioxidants and other compounds

Studies were made on the effects of butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), sodium L-ascorbate (SA), ethoxyquin (EQ) and acetaminophen (AAF) on the induction of neoplastic lesions in the liver, kidney or urinary bladder of rats initiated by N-ethyl-N-hydroxyethylnitrosamine (EHEN), diethylnitrosamine (DEN) or N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN). The number and area of histochemical gamma-glutamyltranspeptidase-positive (gamma-GT+) foci per unit area of liver section in rats given BHA, BHT, EQ or AAP, but not SA, were significantly less than in rats given EHEN or DEN alone. Similarly, the number of hyperplastic nodules (HN) in groups given BHA or AAP and their area in groups given BHA, EQ or AAP were significantly less than in control groups. Induction of hepatocellular carcinoma (HCC) was also clearly inhibited by these three chemicals. In contrast, the incidence and quantitative values of preneoplastic lesions and renal cell adenoma in the group given EHEN were significantly increased in groups given BHA, EQ or AAP administration. For assesing the influence of BHA and BHT on urinary bladder carcinogenesis, rats received BHA or BHT after treatment with BBN. The incidences and the number per unit length of basement membrane of papilloma and carcinomas were significantly increased in rats given BHA. BHT also showed significant increase but values were less than with BHA. These results clearly demonstrated that BHA, BHT, EQ and AAP inhibit the development of gamma-GT+ foci, or HN and HCC, whereas BHA, EQ and AAP enhance the appearance of preneoplastic and neoplastic lesions in the kidney, BHA and BHT also enhancing urinary bladder carcinogenesis.

Air pressure-sensing ability of the middle ear-Investigation of sensing regions and appropriate measurement conditions

OBJECTIVE

To study the association between ear diseases and the ability of the middle ear to sense air pressure changes, we elucidated the appropriate conditions for measurements and confirmed the pressure-sensing regions while quantitatively assessing the pressure-sensing ability of normal ears and of ears with traumatic perforation of the tympanic membrane.

METHODS

In 318 normal ears (159 volunteers), an air pressure of 40daPas(-1) was loaded on to the external auditory canals to measure the minimum pressure sensed by subjects as a result of air pressure changes. The minimum pressure was defined as the minimum sensory threshold for air pressure loading (MSTAP; daPa). In 40 of 318 normal ears (20 volunteers), the MSTAP was measured at 10daPas(-1). Next, topical anesthesia was administered to 5 normal ears (5 volunteers), and the MSTAP was measured. In 7 ears with traumatic tympanic membrane perforation (7 cases), the MSTAP was also measured at the first medical examination. The data were analyzed using Stat View 5.0 (SAS Institute Inc., Cary, NC, USA). To test the significance of the data, the Mann-Whitney U-test and the Wilcoxon test were used.

RESULTS

The mean (+/-S.D.) MSTAP at 40daPas(-1) was -39.2+/-12.2daPa with negative pressure and 39.5+/-12.4daPa with positive pressure. At 10daPas(-1), the MSTAP was -70.3+/-25.0daPa with negative pressure and 72.5+/-22.7daPa with positive pressure, and both the mean and S.D. values were higher than those obtained at 40daPas(-1). Briefly, the MSTAP at 40daPas(-1) produced less variance than that at 10daPas(-1). The MSTAP demonstrated gender- and age-related variations. Moreover, it increased after topical anesthesia was administered to the tympanic membrane. The MSTAP in patients with traumatic tympanic membrane perforation was -205.0+/-26.3daPa with negative pressure and 206.0+/-26.7daPa with positive pressure, and was significantly higher than that observed in case of normal ears.

CONCLUSION

For obtaining accurate measurements while estimating the pressure-sensing ability of the middle ear, the rate of pressure loading should be considered. Although we assume that the middle ear has pressure-sensing regions other than the tympanic membrane, we conclude that the tympanic membrane is the most sensitive pressure-sensing region in the middle ear.

The impact of preoperative magnetic resonance imaging on surgical planning for women with ductal carcinoma in situ

Abstract #1163

Background: Ductal carcinoma in situ (DCIS) accounts for about 20% of all female breast cancers and is now diagnosed 10 times more frequently than prior to the use of increased screening mammography. Although magnetic resonance imaging (MRI) has proven to be a useful imaging modality for invasive cancer, its role and impact in preoperative surgical planning for DCIS is unclear. Our aim is to determine if women diagnosed with pure DCIS on core-biopsy who have preoperative MRI are more likely to undergo mastectomy and sentinel lymph node biopsy (SLNB). Methods: Retrospective survey of women diagnosed with pure DCIS on stereotactic core biopsy between 2000-2007 at an academic tertiary referral center. All women underwent definitive surgical treatment for DCIS. Patient characteristics, surgical planning and surgical outcomes were compared between patients who underwent preoperative MRI and those without MRI. Continuous variables among the two groups were compared using the t-test. Differences in dichotomous variables between groups were compared using the chi-square test. Significance was determined if p&lt;0.05. Results: Of 137 women diagnosed with DCIS, 39 underwent preoperative MRI. Mean age, DCIS size and grade, and presence of invasive cancer on surgical specimen were compared between the two groups. The only significant difference between the two groups was younger mean age in the group with preoperative MRI (51 vs 59 yrs, p=0.001). On univariate analysis, mastectomy and SLNB were more commonly employed in the MRI group. The mastectomy rate was 55% for women who had preoperative MRI and 17% for those who did not (p&lt;0.0001). The SLNB rate was 46% for women had preoperative MRI and 23% for those who did not (p=0.009). Number of re-excisions, margin status and size were compared between the two groups. Preoperative MRI was not significantly associated with wider surgical margins or higher proportion of patients with negative margins. However, the mean number of re-excisions was lower in women who underwent preoperative MRI (0.7 vs. 1.2, p=0.003). The only independent factor associated with likelihood of preoperative MRI in the setting of DCIS was patient age. On multivariate analysis, use of SLNB was independently associated with mastectomy, DCIS size and DCIS grade (p=0.0001, p=0.011, p=0.024, respectively). In contrast, independent predictors of mastectomy were DCIS size and use of MRI (OR 5.1, 95% CI 2.0-13.2)). Conclusion: Women who underwent preoperative MRI for DCIS were younger and more likely to undergo mastectomy. However, women who had preoperative MRI required a lower number of re-excisions to obtain negative margins. Our study cannot address whether the strong association between preoperative MRI and mastectomy is a causal one. Nevertheless our data support a critical need for future studies to further define the benefit as well as consequences of the use of MRI for DCIS evaluation and treatment.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 1163.

Association of T-cell receptor Vbeta haplotypes with dry skin in DS-Nh mice

BACKGROUND

Although dry skin and T cell-dependent disease exacerbation are characteristic features of atopic dermatitis (AD), the involvement of T cells in the development of dry skin remains unclear.

AIMS

We aimed to elucidate the role of T cells in the development of dry skin in DS-Nh mice as a model for AD, and to evaluate this skin condition pharmacologically.

METHODS

We prepared DS-Nh mice harbouring a T-cell receptor (TCR)Vbeta(a) haplotype with a central deletion in the TCRBV gene segments, and mice harbouring a TCRVbeta(b) haplotype without any deletion. We analysed the TCRVbeta chain usage and cytokine response to antimouse CD3 monoclonal antibodies in the splenocytes from the two mouse substrains. Transepidermal water loss (TEWL) was measured, and histochemical examination of these mice was carried out. Finally, a pharmacological analysis using loratadine was also performed to evaluate the features of spontaneous dry skin in DS-Nh mice as a model of AD.

RESULTS

Although the deletion of TCRBV gene segments in the TCRVbeta(a) haplotype yielded different representations of each TCRVbeta mRNA, this deletion did not evoke distinct cytokine profiles in the splenocytes compared with those of mice with the TCRVbeta(b) haplotype. Furthermore, our results indicated that the onset of dry skin occurred earlier in mice with TCRVbeta(b) than in those with TCRVbeta(a). Pharmacologically, AD-like dry skin in DS-Nh with TCRVbeta(b) mice is susceptible to an H1 blocker.

CONCLUSIONS

A specific lymphocyte subpopulation bearing T-cell receptors may be responsible for loratadine-responsive dermatitis in DS-Nh mice.

Novel ecological niche of Cetobacterium somerae, an anaerobic bacterium in the intestinal tracts of freshwater fish

AIMS

This study was conducted to clarify the taxonomic status of Bacteroides type A strains with high vitamin B(12)-producing ability that is widely distributed in the intestinal tracts of freshwater fish.

METHODS AND RESULTS

Seventeen strains of Bacteroides type A isolated from five fish species were all rod-shaped and gram-negative. The strains were positive for esculin hydrolysis, nitrate reduction, resistance to bile, acid phosphatase, and negative for the production of catalase and urease and the susceptibility to vancomycin. The G+C content of DNA from the 17 strains was 29 x 1-31 x 9 mol%, and 16S rDNA sequence analysis revealed a close phylogenetic relationship between Bacteroides type A strains and Cetobacterium somerae sharing 99 x 7-100% sequence similarity. In addition, strains were capable of producing vitamin B(12) at a rate of 1 x 82-13 x 98 ng ml(-1) in 48 h.

CONCLUSION

Phenotypic and phylogenetic characteristics indicated that all isolates previously classified as Bacteroides type A strains belong to C. someare.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study provided the important finding of novel niche of vancomycin-resistant bacteria such as C. somerae in the intestinal tract of freshwater fish.

Plasma protein S activity correlates with protein S genotype but is not sensitive to identify K196E mutant carriers

BACKGROUND

Protein S (PS) is an anticoagulant protein that functions as a cofactor for activated protein C (APC), and congenital PS deficiency is a well-known risk factor for the development of deep vein thrombosis (DVT). Recently, we and others identified the K196E missense mutation in the second epidermal growth factor-like domain of PS as a genetic risk factor for DVT in the Japanese population. The incidence of this mutation is high in the Japanese population.

OBJECTIVES

In the present study, we investigated the relationship between plasma PS activity and the presence of the K196E mutation.

PATIENTS AND METHODS

We measured PS activity as a cofactor activity for APC in 1,862 Japanese individuals and determined the PS K196E genotype in this population.

RESULTS

Individuals heterozygous for the mutant E-allele had lower plasma PS activity than wildtype subjects (mean +/- SD, 71.9 +/- 17.6%, n = 34 vs. 87.9 +/- 19.8%, n = 1,828, P < 0.0001). However, the PS activity of several heterozygous individuals (n = 8) was greater than the population average. In contrast, multiple wildtype subjects (n = 26) had PS activity less than 2 SD below the population mean, indicating that other genetic or environmental factors affect PS activity.

CONCLUSIONS

Plasma PS activity itself is not suitable for identifying PS 196E carriers and other methods are required for carrier detection.

Feeling of ear fullness in acute sensorineural hearing loss

CONCLUSIONS

This study revealed two characteristic findings of the feeling of ear fullness (FEF) in acute sensorineural hearing loss (ASNHL). First, that the appearance of FEF was not associated with the auditory function on audiograms; and second, that the disappearance of FEF is clearly associated with the hearing prognosis.

OBJECTIVE

FEF appears frequently in patients with ASNHL. However, there are few reports on this symptom and its mechanism has yet to be clarified. So we tried to investigate the character of FEF in ASNHL.

PATIENTS AND METHODS

In this study, observations were made during the period from the first medical examination to 2 months after obtaining a steady audiogram on 227 ears from unilateral ASNHL cases, and the relationship between FEF and the audiograms was analyzed.

RESULTS

The FEF prevalence at the first medical examination was about 80% for any audiogram shape or hearing threshold. Moreover, the better the hearing prognosis, the higher the improvement rate of FEF.

The PDZ domain protein PDZK1 interacts with human peptide transporter PEPT2 and enhances its transport activity

The proton-coupled peptide transporter PEPT2 (SLC15A2) mediates the high-affinity low-capacity transport of small peptides as well as various oral peptide-like drugs in the kidney. In contrast to its well-characterized transport properties, there is less information available on its regulatory mechanism, although the interaction of PEPT2 to the PDZ (PSD-95, DglA, and ZO-1)-domain protein PDZK1 has been preliminarily reported. To examine whether PDZK1 is a physiological partner of PEPT2 in kidneys, we started from a yeast two-hybrid screen of a human kidney cDNA library with the C-terminus of PEPT2 (PEPT2 C-terminus (PEPT2-CT)) as bait. We could identify PDZK1 as one of the positive clones. This interaction requires the PDZ motif of PEPT2-CT detected by a yeast two-hybrid assay, in vitro binding assay and co-immunoprecipitation. The binding affinities of second and third PDZ domains of PDZK1 to PEPT2-CT were measured by surface plasmon resonance. Co-immunoprecipitation using human kidney membrane fraction and localization of PEPT2 in renal apical proximal tubules revealed the physiological meaning of this interaction in kidneys. Furthermore, we clarified the mechanism of enhanced glycylsarcosine (Gly-Sar) transport activity in PEPT2-expressing HEK293 cells after the PDZK1 coexpression. This augmentation was accompanied by a significant increase in the V(max) of Gly-Sar transport via PEPT2 and it was also associated with the increased surface expression level of PEPT2. These results indicate that the PEPT2-PDZK1 interaction thus plays a physiologically important role in both oligopeptide handling as well as peptide-like drug transport in the human kidney.