Clinical Utility of Machine Learning Methods Using Regression Models for Diagnosing Eosinophilic Chronic Rhinosinusitis.

Objective: Machine learning methods using regression models can predict actual values of histological eosinophil count from blood eosinophil levels. Therefore, these methods might be useful for diagnosing eosinophilic chronic rhinosinusitis, but their utility still remains unclear. We compared 2 statistical approaches, and investigated the utility of machine learning methods for diagnosing eosinophilic chronic rhinosinusitis. Study Design: Retrospective study. Setting: Medical center. Methods: Data, including eosinophilic levels, obtained from blood and sinonasal samples of 264 patients with chronic rhinosinusitis (257 with and 57 without nasal polyps) were analyzed. We determined factors affecting histopathological eosinophil count in regression models. We also investigated optimal cutoff values for blood eosinophil percentages/absolute eosinophil counts (AECs) through receiver operating characteristic curves and machine-learning methods based on regression models. A histopathological eosinophil count ≥10/high-power field was defined as eosinophilic chronic rhinosinusitis. Results: Blood eosinophil levels, nasal polyp presence, and comorbid asthma were factors affecting histopathological eosinophil count. Cutoffs between the 2 statistical approaches differed in the group with nasal polyps, but not in one without nasal polyps. Machine-learning methods identified blood eosinophil percentages ≥1% or AEC ≥100/µL as cut-offs for eosinophilic chronic rhinosinusitis with nasal polyps, while ≥6% or ≥400/µL for one without nasal polyps. Conclusion: Cut-offs of blood eosinophil levels obtained by machine-learning methods might be useful when suspecting eosinophilic chronic rhinosinusitis prior to biopsy because of their ability to adjust covariates, dealing with overfitting, and predicting actual values of histological eosinophil count.

Effects of Unrestricted Kinematically Aligned Total Knee Arthroplasty with a Modified Soft-Tissue Respecting Technique on the Deformity of Limb Alignment in Japanese Patients.

Background and Objectives: Unrestricted kinematic alignment total knee arthroplasty (KA-TKA) with a soft-tissue respecting technique (STRT) is a soft-tissue-dependent tibial resection entailing the restoration of the original soft-tissue tension using ligamentotaxis after resurfacing the femur, based on the concept of restoring the native or pre-osteoarthritis alignment in each patient. However, there is no consensus on the indications of unrestricted KA-TKA with the STRT. We modified the STRT, followed by an investigation of the effects of surgery on the postoperative hip-knee-ankle angle (HKAA). Materials and Methods: We retrospectively analyzed the clinical background data, including the preoperative and postoperative HKAA, of 87 patients who underwent unrestricted KA-TKA with the modified STRT. Univariate and multivariate analyses were performed to determine the factors affecting the postoperative HKAA. A receiver operating characteristic (ROC) curve was plotted to investigate the change in the cut-off values of preoperative HKAA with respect to the safe zone of the postoperative HKAA. We generated two regression models, the linear regression model and generalized additive model (GAM) using machine learning, to predict the postoperative HKAA. Results: Univariate and multivariate analyses revealed the preoperative HKAA as the factor most relevant to the postoperative HKAA. ROC analysis revealed that the preoperative HKAA exhibited a high predictive utility, with a cut-off value of -10°, when the safe range of postoperative HKAA was set at ±5°. The GAM was the superior machine learning model, indicating a non-linear association between the preoperative and postoperative HKAA. Patients with preoperative HKAAs ranging from -18° to 4° were more likely to fall within the ±5° safe range of the postoperative HKAA. Conclusions: The preoperative HKAA influences the postoperative HKAA in unrestricted KA-TKA with the modified STRT. Machine learning using the GAM may contribute to the selection of patients eligible for the surgical approach.

Comorbidity of eosinophilic chronic rhinosinusitis in chronic eosinophilic pneumonia.

We aimed to elucidate details of comorbid chronic rhinosinusitis (CRS) in chronic eosinophilic pneumonia (CEP) under the collaboration between otolaryngologists and pulmonologists in a prospective study. The CEP diagnosis was performed by pulmonologists based on clinical symptoms, laboratory findings, and/or eosinophilia detected in bronchoalveolar lavage. All patients were referred to otolaryngologists before undergoing oral corticosteroid treatment for CEP. Ten CEP cases visited to otolaryngologists. All cases showed bilateral sinonasal inflammation in computed tomography (CT), indicating comorbid CRS. Nasal polyps (NPs) were observed in 50% of patients on endoscopy. Eighty percent of patients were diagnosed with eosinophilic CRS. In blood eosinophil levels and the mucosal eosinophil count, there were no significant differences between CRS without and with NPs. In Lund-Mackay CT total scores, among-individual variability was observed in CRS with NPs. The collaboration revealed blood/sinonasal eosinophilia and the variability in Lund-Mackay CT total scores as remarkable findings about the comorbid CRS.

Recommendation of using both initial pupil size and constriction latency in pupillary light reflex as objective indicators reflecting subacute pain-related mental fatigue.

A previous study examining clinical subacute pain models under different methodological conditions showed that pain-induced mental fatigue can be associated with decreased initial pupil size (INIT)/shortened constriction latency (LAT) in the pupillary light reflex (PLR). We aimed to investigate the potential of INIT/LAT as objective indicators reflecting mental fatigue under the same methodological conditions. We recruited 118 patients planning to undergo three types of representative otolaryngological head and neck surgery procedures. We used the numerical rating scale (NRS) to assess subjective pain intensity and two mental fatigue-related mood categories of the Profile of Mood States, as well as INIT and LAT measurements (1) in the afternoon one day before surgery (pre1-surgery), (2) in the morning of the day of surgery (pre2-surgery), and (3) in the morning of the day following surgery (post-surgery). We assessed time point-dependent changes using one- or two-way analysis of variance, as well as responses of PLR parameters to mental fatigue using linear mixed-effects models (LMMs). As a result, NRS scores, the two mood categories, as well as LAT and INIT, showed significant time point-dependent changes. In post-hoc analyses, only INIT showed significant changes between the two pre-surgery time points. Thus, INIT values fluctuated even under pain-free conditions due to differences in the time of the day. LMMs demonstrated decreased INIT/shortened LAT related to mental fatigue. All surgical groups showed similar associations between mental fatigue and INIT/LAT findings. As each parameter has advantages and disadvantages, it is recommended to use both INIT and LAT as the indicators.

Clinical potential of pupillary light reflex and heart rate variability parameters as objective indicators of tonsillectomy-induced pain.

Objective.Establishing objective indicators of subjective pain intensity is important in pain assessment. Pupillary light reflex (PLR) and heart rate variability (HRV) indicate autonomic nervous system (ANS) activity and may serve as pain indicators because pain can affect ANS activity. In this prospective longitudinal study, we aimed to investigate the potential of PLR/HRV parameters as objective indicators of subjective pain intensity after tonsillectomy.Approach.Sixty-seven patients undergoing tonsillectomy were enrolled. Subjective pain intensity based on a numeric rating scale (NRS) and eight PLR/HRV parameters were assessed at five time points. We investigated the changes in the NRS values over time. We estimated regression coefficients reflecting parameter changes per unit change in the NRS score using linear mixed-effects models.Main Results.The mean NRS score was 0 at two pre-surgery time points, 5 on postoperative days (PODs) 1 and 2, and 0 at postoperative week 3. Two parameters (initial pupil size [INIT] and constriction latency [LAT]) showed significant changes on POD1 and POD2 in comparison to baseline data measured at the pre-surgery time point. Among these parameters, only LAT showed no significant changes between POD1 and POD2. Significant regression coefficients with the narrowest 95% confidence intervals were observed for INIT and LAT. Increased NRS scores were associated with decreased INIT and shortened LAT.Significance.LAT was a robust indicator of subjective pain intensity. Our patients showed decreased INIT with increased NRS scores, indicating the predominance of the parasympathetic, not sympathetic, tone in pupils. Further studies are required to investigate factors causing this predominance.

Inverted papilloma originating from the lacrimal sac and the nasolacrimal duct with marked FDG accumulation.

Inverted papilloma originating from the lacrimal sac and the nasolacrimal duct is rare, although that in the sinonasal region is a relatively common lesion with local invasion, malignant potential and high recurrence rates after surgery. We report a 52-year-old woman with inverted papilloma of the right lacrimal sac and the nasolacrimal duct, who underwent CT, MR imaging and FDG-PET/CT preoperatively. In addition to CT and MR imaging features similar to those in previous reports, the inverted papilloma exhibited marked FDG accumulation with a maximum standardized uptake value of 7.34 and no other significant FDG accumulation was detected. In summary, our case of inverted papilloma originating from the right lacrimal sac and the nasolacrimal duct noted marked FDG accumulation on PET/CT, which enabled visualization of the localized tumor extension with no metastases.

Clinical factors affecting pupillary light reflex parameters: a single-centre, cross-sectional study.

PURPOSE: To evaluate the effects of stimulus intensity, aging, sex, smoking and eye symmetry on pupillary light reflex (PLR) parameters. METHODS: We evaluated 2812 eyes from 1406 subjects in a single-centre, cross-sectional study. PLR data were collected using four different stimulus intensities. We prepared two models for each of the eight PLR parameters, and defined the model with the lowest values of Akaike's information criterion (AIC) as being the best-fit. Model A was a linear regression model without adjustment for among-individual variability, while the Model B linear mixed-effects models (LMMs) were adjusted for among-individual variability. The regression coefficients of the two models were compared. RESULTS: Model B showed the lowest AIC values for all parameters and the best fit. For light stimulus intensity, age and eye symmetry, the two models yielded similar results for all PLR parameters. For sex and smoking index, some PLR parameters showed the opposite results, i.e., Model A showed significant effects while Model B did not. CONCLUSION: These results indicate that light stimulus intensity, aging, sex, smoking and eye symmetry are factors that affect PLR parameters. These should be adjusted when evaluating the clinical potential of PLR as a diagnostic tool. In addition, adjusting for among-individual variability due to LMMs can improve the model fit and reduce false positives. This can reveal the association between clinical factors and PLR parameters with increased accuracy.

Long-term olfactory function outcomes after pituitary surgery by endoscopic endonasal transsphenoidal approach.

OBJECTIVES: To evaluate long-term olfactory outcomes in patients who underwent pituitary surgery through the endoscopic endonasal transsphenoidal approach (EETSA) by T&T olfactometer. METHODS: We retrospectively reviewed 26 patients who underwent pituitary surgery via EETSA. Olfactory function was assessed by T&T olfactometer before and 6 months after surgery. The mean of recognition thresholds for five different odorants was used. The change in the mean recognition threshold values was evaluated in the entire cohort and the subgroup analysis was performed according to the age, sex, past history of pituitary surgery (primary surgery or revision surgery), histopathology (non-functioning adenoma (NFA) or functioning adenoma (FA)), reconstruction procedure (rescue flap or nasoseptal flap), and superior turbinate management (preserved or resected). RESULTS: Of the 26 patients (12 men and 14 women, median age 53 years), 21 patients were newly diagnosed with pituitary gland tumor (16 NFAs, 5 FAs) and the remaining 5 were diagnosed with recurrent pituitary gland tumor (4 NFAs and 1 FA). In the whole cohort, the mean recognition threshold values of T&T olfactometer significantly improved after surgery (P=0.01). Thirteen out of 26 patients (50%) showed olfactory improvement, whereas only 3 (12%) showed deterioration. In the subgroup analysis, olfactory function outcomes were not significantly different between the subgroups with respect to the age, sex, past history of pituitary surgery, histopathology, reconstruction procedure, or superior turbinate management. The olfactory function tended to worsen in the revision surgery group compared to that in the primary surgery group, but not significantly (P=0.06). CONCLUSIONS: The olfactory function was improved or maintained after pituitary surgery via EETSA in 88% of patients, indicating the benefits of low invasiveness of our surgical treatment. On the other hand, three patients (12%) demonstrated deterioration of olfactory function, suggesting that the risk of postoperative olfactory dysfunction should be informed to patients.

Transplantation of neurons derived from human iPS cells cultured on collagen matrix into guinea-pig cochleae.

The present study examined the efficacy of a neural induction method for human induced pluripotent stem (iPS) cells to eliminate undifferentiated cells and to determine the feasibility of transplanting neurally induced cells into guinea-pig cochleae for replacement of spiral ganglion neurons (SGNs). A stepwise method for differentiation of human iPS cells into neurons was used. First, a neural induction method was established on Matrigel-coated plates; characteristics of cell populations at each differentiation step were assessed. Second, neural stem cells were differentiated into neurons on a three-dimensional (3D) collagen matrix, using the same protocol of culture on Matrigel-coated plates; neuron subtypes in differentiated cells on a 3D collagen matrix were examined. Then, human iPS cell-derived neurons cultured on a 3D collagen matrix were transplanted into intact guinea-pig cochleae, followed by histological analysis. In vitro analyses revealed successful induction of neural stem cells from human iPS cells, with no retention of undifferentiated cells expressing OCT3/4. After the neural differentiation of neural stem cells, approximately 70% of cells expressed a neuronal marker, 90% of which were positive for vesicular glutamate transporter 1 (VGLUT1). The expression pattern of neuron subtypes in differentiated cells on a 3D collagen matrix was identical to that of the differentiated cells on Matrigel-coated plates. In addition, the survival of transplant-derived neurons was achieved when inflammatory responses were appropriately controlled. Our preparation method for human iPS cell-derived neurons efficiently eliminated undifferentiated cells and contributed to the settlement of transplant-derived neurons expressing VGLUT1 in guinea-pig cochleae. Copyright © 2015 John Wiley & Sons, Ltd.

Coronary artery bypass grafting in a patient with hemophilia B: continuous recombinant factor IX infusion as per the Japanese guidelines for replacement therapy.

We herein report our experience of successfully managing the hemostatic system by controlling serum factor IX levels throughout the perioperative period in a patient with hemophilia B. Coronary artery bypass grafting with cardiopulmonary bypass was planned for a 52-year-old man with moderate severity of hemophilia B. During surgery, recombinant factor IX (rFIX; BeneFIX(®) Pfizer Japan inc., Tokyo, Japan) was administered by bolus infusion followed by continuous infusion as per the guidelines of the Japanese Society on Thrombosis and Hemostasis. The operative course was uneventful without any considerable bleeding or complications.

Bladder recovery relates with increased mid-cingulate perfusion after shunt surgery in idiopathic normal-pressure hydrocephalus: a single-photon emission tomography study.

AIMS OF STUDY: It is reported that severe bladder disorder in idiopathic normal-pressure hydrocephalus (iNPH) is predicted by right frontal hypoperfusion. However, it is not known whether bladder recovery is predicted by brain perfusion change after shunt surgery. To address this issue, we compared bladder and brain function before and after shunt surgery in iNPH. METHODS: We enrolled 75 patients in the study. Before and 12 months after shunt surgery, we analyzed brain perfusion by SPECT and bladder disorder by a specialized grading scale. The scale consisted of grade 0, none; grade 1, urinary urgency and frequency; grade 2, urinary incontinence 1-3 times a week; grade 3, urinary incontinence >daily; and grade 4, loss of bladder control. More than one grade improvement is defined as improvement, and more than one grade decrement as worsening; otherwise no changes. RESULTS: Comparing before and after surgery, in the bladder-no-change group (32 cases) there was an increase in blood flow which is regarded as reversal of enlargement in the Sylvian fissure and lateral ventricles (served as control). In contrast, in the bladder-improved group (32 cases) there was an increase in bilateral mid-cingulate, parietal, and left frontal blood flow (p < 0.05). In the bladder-worsened group (11 cases) no significant blood flow change was observed. CONCLUSION: The present study showed that after shunt surgery, bladder recovery is related with mid-cingulate perfusion increase in patients with iNPH. The underlying mechanism might be functional restoration of the mid-cingulate that normally inhibits the micturition reflex.

Absolute structures and bioactivities of euryspongins and eurydiene obtained from the marine sponge Euryspongia sp. collected at Iriomote Island.

Three unique sesquiterpenes, named euryspongins A-C (1-3), have been isolated from the marine sponge Euryspongia sp. The absolute configuration of 1 was assigned as (4R,6R,9S) by comparing its experimental Electronic Circular Dichroism (ECD) spectrum with the calculated ECD spectra of both enantiomers, and the absolute configurations of 2, 3 and artifact 4 were suggested on the basis of that of 1 by assuming common biogenesis of 1-3. These absolute configurations were opposite to those depicted in the previous communication. Further separation of the remaining fractions lead to the isolation of a new C11-polyketide, named as eurydiene (5), together with a known C11-polyketide, nakitriol (6). The structure of 5 was assigned on the basis of its spectroscopic data as a bicyclic alcohol with a diene side chain. Dehydroeuryspongin A (4) inhibited protein tyrosine phosphatase 1B (PTP1B), an important target enzyme for the treatment of type II diabetes and obesity, with an IC50 value of 3.58µM. Moreover, compound 4 did not inhibit the proliferation of human hepatoma Huh-7 cells at 100µM. One of the locations in which PTP1B has been detected is hepatocytes. Compounds 1-3, 5, and 6 were not active against PTP1B. The growth of human colon (HCT-15) and T-cell lymphoma (Jurkat) cells was not disturbed by compounds 1-6.

Pifithrin-alpha has a p53-independent cytoprotective effect on docosahexaenoic acid-induced cytotoxicity in human hepatocellular carcinoma HepG2 cells.

Pifithrin-alpha (PFT) is an inhibitor of p53 and is known to protect against a variety of p53-mediated genotoxic agents. In this report, we examined the inhibitory effects of PFT against docosahexaenoic acid (DHA)-induced cytotoxicity in the human hepatocellular carcinoma (HCC) cell line HepG2. PFT significantly abrogated DHA-induced cytotoxicity in wild-type HepG2 cells (normal expression of p53) and after p53-knockdown by siRNA, as well as in Hep3B (p53 null) and Huh7 (p53 mutant) cells. DHA-induced cytotoxicity is mediated by induction of oxidative stress, and PFT inhibited this event, but it does not exert antioxidant effects. PFT significantly suppressed the release of cytochrome c from mitochondria to cytosol, as well as changes in the mitochondrial membrane potential (ΔΨM) by DHA. Therefore, protection of mitochondria by PFT is crucial for its inhibition of DHA-induced cytotoxicity. Although it has been reported that PFT is able to block p53 function, our data suggest that PFT also has a p53-independent inhibition mechanism. This work provided insights into the mechanisms of PFT action on DHA-induced cytotoxicity in HCC.

Combined effect of papuamine and doxorubicin in human breast cancer MCF-7 cells.

Our previous study reported that an extract of an Indonesian marine sponge, Haliclona sp., showed potent cytotoxicity and induced apoptosis. The major cytotoxic chemical compound was identified as papuamine, which caused reduction of cell survival through activation of c-Jun N-terminal kinase (JNK) in human breast cancer MCF-7 cells. Doxorubicin (DOX), a Streptomyces metabolite, is used in chemotherapy against a wide range of cancers, including breast cancer. The present study examined the combined effect of papuamine and DOX on MCF-7 cells. The effect of these reagents on cell growth was assessed by a colony formation assay. Incubation with either of the reagents alone resulted in concentration-dependent decreases in the colony formation of the MCF-7 cells. Incubation with the reagents together at sub-cytotoxic concentrations resulted in significant decreases in colony formation. The phosphorylation of JNK, the activated form of the protein, was elevated in a concentration-dependent manner upon co-incubation with papuamine and DOX. Fluorescence intensity analysis demonstrated that papuamine caused a small, but non-significant, decrease in cellular accumulation of DOX. These results indicate that the combinatory effect of papuamine and DOX is not associated with changes in the cellular accumulation of DOX, and may instead reflect additive effects on JNK activation. This study indicates that papuamine may represent a novel type of modulator for DOX chemotherapy.

Therapeutic potential of a gamma-secretase inhibitor for hearing restoration in a guinea pig model with noise-induced hearing loss.

BACKGROUND: Notch signaling plays a crucial role in the fate determination of cochlear progenitor cells, hair cells, and supporting cells in the developing cochlea. Recent studies have demonstrated the temporal activation of Notch signaling in damaged mature cochleae, and have demonstrated the induction of new hair cells by pharmacologically inhibiting Notch signaling. The present study aimed to illustrate the feasibility of pharmacologically inhibiting Notch signaling by using a gamma-secretase inhibitor for treating sensorineural hearing loss. RESULTS: The effect of the sustained local delivery of MDL28170, a gamma-secretase inhibitor, on hearing and hair cell induction was tested in a guinea pig model with noise-induced hearing loss. MDL28170 was directly delivered into the cochlear fluids via a micro-osmotic pump. Drug application was initiated 7 days after noise exposure. Measurements of auditory brainstem responses revealed better hearing in the MDL28170-treated animals than in the vehicle controls. Histological analysis demonstrated a higher number of outer hair cells in the MDL28170-treated cochleae than the vehicle-treated cochleae. CONCLUSION: These findings strongly suggest that local sustained delivery of a gamma-secretase inhibitor into the cochlea could be a novel strategy for treating acute hearing loss that is refractory to conventional treatment.

Caprice/MISP is a novel F-actin bundling protein critical for actin-based cytoskeletal reorganizations.

Caprice [C19orf21 actin-bundling protein in characteristic epithelial cells, also called mitotic interactor and substrate of Plk1 (MISP)] is a novel actin-related protein identified in the highly-insoluble subcellular scaffold proteins. This protein contains multiple actin-binding sites, forms characteristic mesh-like F-actin bundles in vitro, and exhibits capricious localization and expression patterns in vivo. Overexpression or knock-down of Caprice resulted in a dramatic effect on cellular morphology by inducing stress fiber-like thick filaments or filopodial formations, respectively. Caprice is expressed and localized in distinct cells and tissues with specialized actin-based structures, such as growth cones of migrating neurons and stereocilia of inner ear hair cells. However, Caprice gene expression is varied among different cell types; especially enriched in several epithelial cells whereas relatively suppressed in a subset of epithelial cells, fibroblasts, and neuroblastoma cells at the transcriptional level. Thus, this protein is expected to be an effector for cell type-specific actin reorganization with its direct actin-binding properties and provides a novel model of cell morphology regulation by a non-ubiquitous single actin-bundling protein.

Cytotoxic effects of caffeic acid undecyl ester are involved in the inhibition of telomerase activity in NALM-6 human B-cell leukemia cells.

Our previous study reported that caffeic acid undecyl ester (CAUE) has a potent cytotoxic effect and induces apoptosis in NALM-6 cells, but not in normal human lymphocytes. The majority of normal human cells have no detectable telomerase activity, however, activity is commonly detected in cancer cells. Thus, inhibiting telomerase activity and inducing apoptosis may have a selective effect on cancer cells. The aim of the present study was to investigate the inhibitory effects of telomerase activity by CAUE in a NALM-6 cell culture system. CAUE was shown to preferentially damage DNA synthesis compared with RNA or protein synthesis. In addition, telomerase activity was significantly suppressed and the activity of human telomerase reverse transcriptase (hTERT), a subunit of telomerase, was decreased following treatment with CAUE, each in a concentration-dependent manner. These results indicated that the cytotoxic effects of CAUE are mediated by the inhibition of DNA synthesis and telomerase activity. The present study is the first to identify the cytotoxic mechanisms of CAUE in leukemia cells.

Papuamine causes autophagy following the reduction of cell survival through mitochondrial damage and JNK activation in MCF-7 human breast cancer cells.

We previously reported that extracts of an Indonesian marine sponge Haliclona sp. showed potent cytotoxicity and the induction of apoptosis against human solid cancer cell lines. In this study, we examine the cytotoxic mechanism of the major chemical compound, papuamine, on MCF-7 human breast cancer cells. Papuamine at 5 µM did not show significant cytotoxic effects after incubation for 24 h, but autophagosome vesicular formation was apparent. At 10 µM of papuamine, significant reduction in cell survival was observed at 12 h, and increases in autophagy at this concentration were time-dependent and apparent before the appearance of cytotoxic effects. Both the release of cytochrome c to the cytosol and increase in Bax in the mitochondrial fraction were found to be concentration-dependent. Moreover, mitochondrial membrane potential shows concentration- and time-dependent decreases with exposure to papuamine. The release of cytochrome c has been shown to be accompanied by an increase in JNK activation. 3-Methyladenine (MA), a classical autophagy inhibitor showed increased JNK activation by exposure to papuamine. In conclusion, our results indicate that papuamine causes earlier onset autophagy and delayed reduction of cell survival through mitochondrial damage and JNK activation in MCF-7 cells.

A polybromodiphenyl ether from an Indonesian marine sponge Lamellodysidea herbacea and its chemical derivatives inhibit protein tyrosine phosphatase 1B, an important target for diabetes treatment.

The ethanol extract of an Indonesian marine sponge Lamellodysidea herbacea inhibited the activity of protein tyrosine phosphatase 1B (PTP1B), an important target enzyme for the treatment of type II diabetes. Bioassay-guided isolation yielded a known polybromodiphenyl ether (1) as a sole bioactive component. The structure of 1 was confirmed by spectroscopic data for 1 and its methyl ether derivative (2). Compound 1 markedly inhibited the PTP1B activity (IC50 = 0.85 µM) and showed a moderate cytotoxicity against two human cancer cell lines, HCT-15 (colon) and Jurkat (T-cell lymphoma) cells. On the other hand, compound 2 maintained potent inhibitory activity against PTP1B (IC50 = 1.7 µM) but did not show apparent cytotoxicity at 18 µM against these cancer cells. Four ester derivatives [acetyl (3), butyryl (4), hexanoyl (5), and benzoyl (6)] were prepared from 1 and their activities evaluated against PTP1B and two cancer cell lines to investigate the structure-activity relationships. Although compounds 3-6 exhibited potent inhibitory effects against PTP1B activity, cytotoxicity against HCT-15 and Jurkat cells was observed as a similar efficacy to that of 1. From these results, compound 2 was found to be the best inhibitor of PTP1B with no apparent cytotoxicity. Therefore, 2 may be a lead compound for making a new type of PTP1B inhibitor. Moreover, compound 2 did not inhibit the cell growth of Huh-7 cells (hepatoma). Hepatocytes are one of the locations of PTP1B, and Huh-7 cells are used to study the mechanism of action of compound 2.

Induction of apoptosis by a potent caffeic acid derivative, caffeic acid undecyl ester, is mediated by mitochondrial damage in NALM-6 human B cell leukemia cells.

Caffeic acid esters have various biological activities, and we previously reported that undecyl caffeate (caffeic acid undecyl ester, CAUE), a new caffeic acid derivative, has strong pharmacological activity. The present study investigated the cytotoxicity of both CAUE and its parent compound, caffeic acid phenethyl ester (CAPE), and characterized the mechanisms by which they induce apoptosis in the human B cell leukemia cell line NALM-6. Treatment with CAUE reduced cell survival in NALM-6 cells but had no significant effect on the survival of normal lymphocytes. When assessing the 50% inhibitory concentration (IC(50)) for cytotoxicity, CAUE had 10-fold higher activity than CAPE in NALM-6 cells. CAUE treatment resulted in induction of apoptotic features in NALM-6 cells, including cleaved poly (ADP-ribose) polymerase and activated caspase-3. A caspase inhibitor completely blocked CAUE-induced apoptosis. CAUE treatment resulted in a concentration- and time-dependent decrease in both mitochondrial membrane potential and downregulation of Bcl-2 expression. Moreover, CAUE-induced apoptosis was enhanced in the Bcl-2 knockdown condition induced by small interfering RNA. These data suggest that CAUE-induced apoptosis was mediated via an apoptotic intrinsic pathway including mitochondrial damage and was caspase-dependent. These data also suggest that CAUE is a powerful anti-leukemic agent that acts via induction of apoptosis by mitochondrial damage and selective action in leukemia cells.