Development and validation of the SickKids Enterprise-wide Data in Azure Repository (SEDAR)

Objectives

To describe the processes developed by The Hospital for Sick Children (SickKids) to enable utilization of electronic health record (EHR) data by creating sequentially transformed schemas for use across multiple user types.

Methods

We used Microsoft Azure as the cloud service provider and named this effort the SickKids Enterprise-wide Data in Azure Repository (SEDAR). Epic Clarity data from on-premises was copied to a virtual network in Microsoft Azure. Three sequential schemas were developed. The Filtered Schema added a filter to retain only SickKids and valid patients. The Curated Schema created a data structure that was easier to navigate and query. Each table contained a logical unit such as patients, hospital encounters or laboratory tests. Data validation of randomly sampled observations in the Curated Schema was performed. The SK-OMOP Schema was designed to facilitate research and machine learning. Two individuals mapped medical elements to standard Observational Medical Outcomes Partnership (OMOP) concepts.

Results

A copy of Clarity data was transferred to Microsoft Azure and updated each night using log shipping. The Filtered Schema and Curated Schema were implemented as stored procedures and executed each night with incremental updates or full loads. Data validation required up to 16 iterations for each Curated Schema table. OMOP concept mapping achieved at least 80 % coverage for each SK-OMOP table.

Conclusions

We described our experience in creating three sequential schemas to address different EHR data access requirements. Future work should consider replicating this approach at other institutions to determine whether approaches are generalizable.

Comparing the Hospital Frailty Risk Score and the Clinical Frailty Scale Among Older Adults With Chronic Obstructive Pulmonary Disease Exacerbation

IMPORTANCE

Frailty is associated with severe morbidity and mortality among people with chronic obstructive pulmonary disease (COPD). Interventions such as pulmonary rehabilitation can treat and reverse frailty, yet frailty is not routinely measured in pulmonary clinical practice. It is unclear how population-based administrative data tools to screen for frailty compare with standard bedside assessments in this population.

OBJECTIVE

To determine the agreement between the Hospital Frailty Risk Score (HFRS) and the Clinical Frailty Scale (CFS) among hospitalized individuals with COPD and to determine the sensitivity and specificity of the HFRS (vs CFS) to detect frailty.

DESIGN, SETTING, AND PARTICIPANTS

A cross-sectional study was conducted among hospitalized patients with COPD exacerbation. The study was conducted in the respiratory ward of a single tertiary care academic hospital (The Ottawa Hospital, Ottawa, Ontario, Canada). Participants included consenting adult inpatients who were admitted with a diagnosis of acute COPD exacerbation from December 2016 to June 2019 and who used a clinical care pathway for COPD. There were no specific exclusion criteria. Data analysis was performed in March 2022.

EXPOSURE

Degree of frailty measured by the CFS.

MAIN OUTCOMES AND MEASURES

The HFRS was calculated using hospital administrative data. Primary outcomes were the sensitivity and specificity of the HFRS to detect frail and nonfrail individuals according to CFS assessments of frailty, and the secondary outcome was the optimal probability threshold of the HFRS to discriminate frail and nonfrail individuals.

RESULTS

Among 99 patients with COPD exacerbation (mean [SD] age, 70.6 [9.5] years; 56 women [57%]), 14 (14%) were not frail, 33 (33%) were vulnerable, 18 (18%) were mildly frail, and 34 (34%) were moderately to severely frail by the CFS. The HFRS (vs CFS) had a sensitivity of 27% and specificity of 93% to detect frail vs nonfrail individuals. The optimal probability threshold for the HFRS was 1.4 points or higher. The corresponding sensitivity to detect frailty was 69%, and the specificity was 57%.

CONCLUSIONS AND RELEVANCE

In this cross-sectional study, using the population-based HFRS to screen for frailty yielded poor detection of frailty among hospitalized patients with COPD compared with the bedside CFS. These findings suggest that use of the HFRS in this population may result in important missed opportunities to identify and provide early intervention for frailty, such as pulmonary rehabilitation.

Ensemble forecast experiments of summertime sea ice in the Arctic Ocean using the TOPAZ4 ice-ocean data assimilation system

Precise information on sea ice thickness (SIT) and its prediction at medium-range (2-week) timescale is crucial for the safe maritime navigation in the Arctic Ocean. In this study, we investigate the sensitivity of medium-range prediction skill of summertime SIT distribution in the Arctic marginal seas to atmospheric forecast data, using the 51-member ECMWF operational ensemble prediction system (EPS). For a synoptic-scale cyclone event occurred in July 5-6, 2015, two-week probabilistic forecast experiments were conducted with the TOPAZ4 ice-ocean forecast system, starting on 1st July. The ensemble correlation analysis between the forecast SIT and the meteorological parameters shows that the forecast error of SIT distribution is sensitive to the sea ice drift speed until 1-week, indicating that realistic sea ice drift improves the sea ice thickness prediction. On the other hand, beyond 1 week lead, the forecast error of SIT distribution is more sensitive to surface heat flux rather than sea ice drift. The surface heat flux signal is confined to the sea ice edge region, where the shortwave radiation flux is related to the SIT change through the sea ice melting process. The shortwave radiation flux in the sea ice edge is mostly determined by the sea ice distribution, suggesting that the skillful prediction of sea ice distribution, which is largely affected by synoptic-scale disturbance, at shorter lead times indirectly affects the medium-range forecast skill. A comparison of different ensemble perturbation techniques shows that the prediction skill is better at shorter lead times (up to 1 week), when using an atmospheric EPS rather than the random perturbations used in the operational forecast system, but the random perturbations are advantageous beyond 1 week. Thus, the application of the EPS to an ice-ocean coupled forecast system leads to a more precise sea ice prediction on medium-range timescale, which we expect to become of practical use for the optimum shipping route in the Arctic Ocean.

Algorithms for left atrial wall segmentation and thickness - Evaluation on an open-source CT and MRI image database

Structural changes to the wall of the left atrium are known to occur with conditions that predispose to Atrial fibrillation. Imaging studies have demonstrated that these changes may be detected non-invasively. An important indicator of this structural change is the wall's thickness. Present studies have commonly measured the wall thickness at few discrete locations. Dense measurements with computer algorithms may be possible on cardiac scans of Computed Tomography (CT) and Magnetic Resonance Imaging (MRI). The task is challenging as the atrial wall is a thin tissue and the imaging resolution is a limiting factor. It is unclear how accurate algorithms may get and how they compare in this new emerging area. We approached this problem of comparability with the Segmentation of Left Atrial Wall for Thickness (SLAWT) challenge organised in conjunction with MICCAI 2016 conference. This manuscript presents the algorithms that had participated and evaluation strategies for comparing them on the challenge image database that is now open-source. The image database consisted of cardiac CT (n=10) and MRI (n=10) of healthy and diseased subjects. A total of 6 algorithms were evaluated with different metrics, with 3 algorithms in each modality. Segmentation of the wall with algorithms was found to be feasible in both modalities. There was generally a lack of accuracy in the algorithms and inter-rater differences showed that algorithms could do better. Benchmarks were determined and algorithms were ranked to allow future algorithms to be ranked alongside the state-of-the-art techniques presented in this work. A mean atlas was also constructed from both modalities to illustrate the variation in thickness within this small cohort.

Autophagy is required for cell survival under L-asparaginase-induced metabolic stress in acute lymphoblastic leukemia cells

L-asparaginase has been used for more than three decades in acute lymphoblastic leukemia (ALL) patients and remains an essential drug in the treatment of ALL. Poor response to L-asparaginase is associated with increased risk of therapeutic failure in ALL. However, both the metabolic perturbation and molecular context of L-asparaginase-treated ALL cells has not been fully elucidated. Here we identify that treatment with L-asparaginase results in metabolic shutdown via the reduction of both glycolysis and oxidative phosphorylation, accompanied by mitochondrial damage and activation of autophagy. The autophagy is involved in reducing reactive oxygen species (ROS) level by eliminating injured mitochondria. Inhibition of autophagy enhances L-asparaginase-induced cytotoxicity and overcomes the acquired resistance to L-asparaginase in ALL cells. The ROS-p53-positive feedback loop is an essential mechanism of this synergistic cytotoxicity. Thus, our findings provide the rationale for the future development of combined treatment of L-asparaginase and anti-autophagy drug in ALL patients.

Shape complexes: the intersection of label orderings and star convexity constraints in continuous max-flow medical image segmentation

Optimization-based segmentation approaches deriving from discrete graph-cuts and continuous max-flow have become increasingly nuanced, allowing for topological and geometric constraints on the resulting segmentation while retaining global optimality. However, these two considerations, topological and geometric, have yet to be combined in a unified manner. The concept of "shape complexes," which combine geodesic star convexity with extendable continuous max-flow solvers, is presented. These shape complexes allow more complicated shapes to be created through the use of multiple labels and super-labels, with geodesic star convexity governed by a topological ordering. These problems can be optimized using extendable continuous max-flow solvers. Previous approaches required computationally expensive coordinate system warping, which are ill-defined and ambiguous in the general case. These shape complexes are demonstrated in a set of synthetic images as well as vessel segmentation in ultrasound, valve segmentation in ultrasound, and atrial wall segmentation from contrast-enhanced CT. Shape complexes represent an extendable tool alongside other continuous max-flow methods that may be suitable for a wide range of medical image segmentation problems.

Effect of Left Atrial Wall Thickness on Radiofrequency Ablation Success

INTRODUCTION

Radiofrequency (RF) ablation in thicker regions of the left atrium (LA) may require increased ablation energy in order to achieve effective transmural lesions. Consequently, many cases of recurrent atrial fibrillation (AF) postablation may be due to thicker-than-normal atrial tissue. The aim of this study was to test the hypotheses that patients with recurrent AF have thicker tissue overall and that electrical reconnection is more likely in regions of thicker tissue.

METHODS AND RESULTS

Retrospective analysis was performed on 86 CT images acquired preoperatively from a cohort of 119 patients who had undergone RF ablation for AF. Of these, 33 patients experienced recurrence of AF within 1 year of initial treatment and 29 returned for a repeat ablation. For each patient, LA wall thickness (LAWT) was measured from the images in 12 anatomical regions using custom software. Patients with recurrent AF had larger LAWT compared to successfully treated patients (1.6 ± 0.6 mm vs. 1.5 ± 0.5 mm, P < 0.001) and reconnection was found to be at regions of thicker tissue (1.6 ± 0.6 mm, P = 0.038) compared to nonreconnected regions (1.5 ± 0.5 mm). The superior right posterior wall of the LA was significantly related to both recurrence (P = 0.048) and reconnection (P = 0.014).

CONCLUSION

Increased LAWT has a small but significant effect on postablation recurrence and reconnection. Measures of LAWT may facilitate appropriate dosing of RF energy, but other factors will be critical in transmural lesion formation and ablation success.

Excess NF-κB induces ectopic odontogenesis in embryonic incisor epithelium

Nuclear factor kappa B (NF-κB) signaling plays critical roles in many physiological and pathological processes, including regulating organogenesis. Down-regulation of NF-κB signaling during development results in hypohidrotic ectodermal dysplasia. The roles of NF-κB signaling in tooth development, however, are not fully understood. We examined mice overexpressing IKKβ, an essential component of the NF-κB pathway, under keratin 5 promoter (K5-Ikkβ). K5-Ikkβ mice showed supernumerary incisors whose formation was accompanied by up-regulation of canonical Wnt signaling. Apoptosis that is normally observed in wild-type incisor epithelium was reduced in K5-Ikkβ mice. The supernumerary incisors in K5-Ikkβ mice were found to phenocopy extra incisors in mice with mutations of Wnt inhibitor, Wise. Excess NF-κB activity thus induces an ectopic odontogenesis program that is usually suppressed under physiological conditions.

Prevention of postoperative pulmonary complications through intensive preoperative respiratory rehabilitation in patients with esophageal cancer

Postoperative pulmonary complications (PPCs) after esophagectomy have been reported to occur in 15.9-30% of patients and lead to increased postoperative morbidity and mortality, prolonged duration of hospital stay, and additional medical costs. The purpose of this retrospective cohort study was to investigate the possible prevention of PPCs by intensive preoperative respiratory rehabilitation in esophageal cancer patients who underwent esophagectomy. The subjects included 100 patients (87 males and 13 females with mean age 66.5 ± 8.6 years) who underwent esophagectomy. They were divided into two groups: 63 patients (53 males and 10 females with mean age 67.4 ± 9.0 years) in the preoperative rehabilitation (PR) group and 37 patients (34 males and 3 females with mean age 65.0 ± 7.8 years) in the non-PR (NPR) group. The PR group received sufficient preoperative respiratory rehabilitation for >7 days, and the NPR group insufficiently received preoperative respiratory rehabilitation or none at all. The results of the logistic regression analysis and multivariate analysis to correct for all considerable confounding factors revealed the rates of PPCs of 6.4% and 24.3% in the PR group and NPR group, respectively. The PR group demonstrated a significantly less incidence rate of PPCs than the NPR group (odds ratio: 0.14, 95% confidential interval: 0.02~0.64). [Correction added after online publication 25 June 2012: confidence interval has been changed from -1.86~ -0.22] This study showed that the intensive preoperative respiratory rehabilitation reduced PPCs in esophageal cancer patients who underwent esophagectomy.

Preparation of Thin Polycarbonate Film and Its Application to PIXE Analysis of Anionic Elements in Water Samples

A polycarbonate film of thin and uniform thickness was prepared. A casting solution for film-formation was made up by diluting a solution of poly (bisphenol A carbonate) in chloroform by a factor of two to three with benzene. A uniform film was created by dropping 0.2-0.3 cm3 of the casting solution slowly on a water surface within an aperture (20 mm diameter) of Mylar target frame floating on 50 wt% sucrose aqueous solution. Films of 0.14-0.27 mg/cm2 thickness thus prepared offer a good combination of mechanical strength and low continuum backgrounds. To test PIXE analysis of anionic species in water, targets containing SO 42-, Cr 2 O 72-, AsO 43-, and Ga 3+-internal standard were prepared by depositing 100 μl of the test solutions onto the polycarbonate film, and irradiated in vacuum by 3 MeV proton beams. The difference between the nominal and the analyzed concentrations seldom exceeded ± 15 % in the range from 10 to 2000 ppb.

Four-year study of lamivudine and adefovir combination therapy in lamivudine-resistant hepatitis B patients: influence of hepatitis B virus genotype and resistance mutation pattern

To investigate the efficacy of long-term lamivudine (3TC) and adefovir dipivoxil (ADV) combination therapy in 3TC-resistant chronic hepatitis B virus (HBV) infected patients, we analysed 28 3TC-resistant patients treated with the combination therapy during 47 months (range, 9-75). At 12, 24, 36, and 48 months, the rates of virological response with undetectable HBV DNA (≤ 2.6 log copies/mL) were 56, 80, 86, and 92%, respectively. Among 17 hepatitis B e antigen (HBeAg)-positive patients, HBeAg disappeared in 24% at 12 months, 25% at 24 months, 62% at 36 months, and 88% at 48 months. When HBV genotypes were compared, patients with genotype B achieved virological response significantly more rapidly than those with genotype C (P=0.0496). One patient developed virological breakthrough after 54 months, and sequence analysis of HBV obtained from the patient was performed. An rtA200V mutation was present in the majority of HBV clones, in addition to the 3TC-resistant mutations of rtL180M+M204V. The rtN236T ADV-resistant mutation was observed in only 25% clones. In vitro analysis showed that the rtA200V mutation recovered the impaired replication capacity of the clone with the rtL180M+M204V mutations and induced resistance to ADV. Moreover, rtT184S and rtS202C, which are known entecavir-resistant mutations, emerged in some rtL180M+M204V clones without rtA200V or rtN236T. In conclusion, 3TC+ADV combination therapy was effective for most 3TC-resistant patients, especially with genotype B HBV, but the risk of emergence of multiple drug-resistant strains with long-term therapy should be considered. The mutation rtA200V with rtL180M+M204V may be sufficient for failure of 3TC+ADV therapy.

Giant orbital Hall effect in transition metals: origin of large spin and anomalous Hall effects

In transition metals and their compounds, the orbital degrees of freedom gives rise to an orbital current, in addition to the ordinary spin and charge currents. We reveal that considerably large spin and anomalous Hall effects observed in transition metals originate from an orbital Hall effect (OHE). To elucidate the origin of these novel Hall effects, a simple periodic s-d hybridization model is proposed as a generic model. The giant positive OHE originates from the orbital Aharonov-Bohm phase factor, and induces spin Hall conductivity that is proportional to the spin-orbit polarization at the Fermi level, which is positive (negative) in metals with more than (less than) half filling.

Sharp contrasts in low-energy quasiparticle dynamics of graphite between Brillouin zone K and H points

The low-energy quasiparticle (QP) dynamics of graphite are governed by a coupling with the E(2g) longitudinal optical phonon of omega(LO) approximately 200 meV, which is found to dramatically depend on the electronic band dispersion epsilon(k). A discontinuity of the QP linewidth develops near omega(LO) for a linear band with a quadratic band top [near the Brillouin zone (BZ) K point], while it disappears for a pure linear band (near the BZ H point). It is also found that the effective electron-phonon coupling near the K point is stronger than near the H point by more than 50%. This finding makes possible a consistent understanding of recent angle-resolved photoemission observations near the K point.

Giant intrinsic spin and orbital hall effects in Sr2MO4 (M=Ru, Rh, Mo)

We investigate the intrinsic spin Hall conductivity (SHC) and the d-orbital Hall conductivity (OHC) in metallic d-electron systems, by focusing on the t2g-orbital tight-binding model for Sr2MO4 (M=Ru, Rh, Mo). The conductivities obtained are one or 2 orders of magnitude larger than predicted values for p-type semiconductors with approximately 5% hole doping. The origin of these giant Hall effects is the "effective Aharonov-Bohm phase" that is induced by the d-atomic angular momentum in connection with the spin-orbit interaction and the interorbital hopping integrals. The huge SHC and OHC generated by this mechanism are expected to be ubiquitous in multiorbital transition metal compounds, which opens the possibility of realizing spintronics as well as "orbitronics" devices.

Depositional records of plutonium and (137)Cs released from Nagasaki atomic bomb in sediment of Nishiyama reservoir at Nagasaki

In a sediment core of Nishiyama reservoir at Nagasaki city, depth profiles of (240)Pu/(239)Pu isotopic ratio, (239+240)Pu and (137)Cs activities were determined. Sediments containing plutonium and (137)Cs, which were deposited immediately after a detonation of Nagasaki atomic bomb, were identified in the core. Observed below the sediments were macroscopic charcoals, providing evidence for initial deposit of the fallout of the Nagasaki atomic bomb. This is the first entire depositional records of plutonium and (137)Cs released from the Nagasaki atomic bomb together with those from atmospheric nuclear tests.

POU2AF1, an amplification target at 11q23, promotes growth of multiple myeloma cells by directly regulating expression of a B-cell maturation factor, TNFRSF17

Multiple myeloma (MM), a progressive hematological neoplasm, is thought to result from multiple genetic events affecting the terminal plasma cell. However, genetic aberrations related to MM are seldom reported. Using our in-house array-based comparative genomic hybridization system to locate candidate target genes with following their expression analysis, we identified POU2AF1 at 11q23.1 as a probable amplification target in MM cell lines. POU2AF1 is a B-cell-specific transcriptional co-activator, which interacts with octamer-binding transcription factors Oct-1 and Oct-2, and augments their function. Downregulation of POU2AF1 expression by specific small-interfering RNA (siRNA) inhibited MM cell growth, whereas ectopic expression of POU2AF1 promoted growth of MM cells. Among putative transcriptional targets for POU2AF1, B-cell maturation factor, TNFRSF17, enhanced its transcription by POU2AF1, and POU2AF1 directly bound to an octamer site within the 5' region of TNFRSF17. Expression level of TNFRSF17 was closely correlated with that of POU2AF1 in cell lines and primary samples of MM, and decreasing TNFRSF17 expression by means of TNFRSF17 siRNA inhibited MM cell growth. Taken together, our results suggest that POU2AF1, when activated by amplification or other mechanisms, may contribute to progression of MM by accelerating growth of MM cells through direct transactivation of one of its target genes, TNFRSF17.

Epigenetic silencing of prostaglandin E receptor 2 (PTGER2) is associated with progression of neuroblastomas

We previously identified a cluster of prostanoid receptor genes, prostaglandin D2 receptor (PTGDR) and prostaglandin E receptor 2 (PTGER2), as possible targets for DNA methylation in advanced types of neuroblastoma (NB) using bacterial artificial chromosome array-based methylated CpG island amplification method. Among them, in this study, we found that PTGER2 was frequently silenced in NB cell lines, especially in those with MYCN amplification, through epigenetic mechanisms. In NB cell lines, DNA methylation pattern within a part of CpG island was inversely correlated with PTGER2 expression, and histone H3 and H4 deacetylation and histone H3 lysine 9 methylation within the putative promoter region were more directly correlated with silencing of this gene. Methylation of PTGER2 was observed more frequently in advanced-type of primary NBs compared with early-stage tumors. Growth of NB cells lacking endogenous PTGER2 expression was inhibited by restoration of the gene product by transient and stable transfection. A PTGER2-selective agonist, butaprost, increased intracellular cyclic adenosine monophosphate (cAMP) level, inhibited cell growth and induced apoptosis of NB cells stably expressing exogenous PTGER2. 8-Bromo-cAMP also inhibited growth of NB cells lacking PTGER2 expression, but not cells expressing this gene. Taken together, it is suggested that NB cells may lose responsiveness to PTGER2-mediated growth inhibition/apoptosis through epigenetic silencing of PTGER2 and/or disruption of downstream cAMP-dependent pathway during the neuroblastomagenesis.

Frequent methylation-associated silencing of a candidate tumor-suppressor, CRABP1, in esophageal squamous-cell carcinoma

Epigenetic alterations and the resulting inactivation of tumor suppressor genes often contribute to the development of various cancers. To identify novel candidates that may be silenced by aberrant methylation in esophageal squamous-cell carcinoma (ESCC), we analysed ESCC cell lines by a recently developed method known as bacterial artificial chromosome array-based methylated CpG island amplification (BAMCA), and selected candidates through BAMCA-assisted strategy. In the course of this program, we identified frequent CpG methylation-dependent silencing of the gene encoding cellular retinoic acid binding protein 1 (CRABP1) in our panel of ESCC cell lines. Expression of CRABP1 mRNA was restored in gene-silenced ESCC cells after treatment with 5-aza 2'-deoxycytidine. The DNA methylation status of the CRABP1 CpG island with clear promoter activity correlated inversely with expression of this gene. CpG methylation of CRABP1 was frequently observed in primary ESCC tissues as well. Restoration of CRABP1 expression in ESCC cells lacking the protein reduced cell growth by inducing arrest at G(0)-G(1), whereas knockdown of the gene in cells expressing CRABP1 promoted cell growth. Among 113 primary ESCC tumors, the absence of immunoreactive CRABP1 was significantly associated with de-differentiation of cancer cells and with distant lymph-node metastases in the patients. These results indicate that CRABP1 appears to have a tumor-suppressor function in esophageal epithelium, and its epigenetic silencing may play a pivotal role during esophageal carcinogenesis. Its expression status in biopsies or resected tumors might serve as an index for identifying ESCC patients for whom combined therapeutic modalities would be recommended.

Exotic radiation from a photonic crystal excited by an ultrarelativistic electron beam

We report the observation of an exotic radiation (unconventional Smith-Purcell radiation) from a one-dimensional photonic crystal. The physical origin of the exotic radiation is direct excitation of the photonic bands by an ultrarelativistic electron beam. The spectrum of the exotic radiation follows photonic bands of a certain parity, in striking contrast to the conventional Smith-Purcell radiation, which shows solely a linear dispersion. Key ingredients for the observation are the facts that the electron beam is in an ultrarelativistic region and that the photonic crystal is finite. The origin of the radiation was identified by comparison of experimental and theoretical results.

Ultrafast Fano resonance between optical phonons and electron-hole pairs at the onset of quasiparticle generation in a semiconductor

Based on the many-body time-dependent approach applied to the ultrafast time region, we investigate the dynamics of creation of an optical phonon incorporating with the electron-hole continuum in a semiconductor. In the transient Fano resonance, due to an interference between those sharp (optical phonon) and continuum (electron-hole pair) quasiparticles, we find the robust destructive interference at birth of them, i.e., tau approximately 0 if the created phonon is coherent under the irradiation of ultrashort optical pulses. The origin is found to be the potential scattering of the electron-hole pair by the q=0 coherent phonon. This finding agrees well with the recent experiment.

A novel amplification target, DUSP26, promotes anaplastic thyroid cancer cell growth by inhibiting p38 MAPK activity

Anaplastic thyroid cancer (ATC) is one of the most lethal of all human tumors, but cytogenetic information concerning ATC is extremely limited. Using our in-house array-based comparative genomic hybridization and 14 ATC cell lines with further fluorescence in situ hybridization analysis, we demonstrated amplification of the DUSP26 gene, known by another report as MAP kinase phosphatase-8. DUSP26 was overexpressed in ATC cell lines and primary ATC tumor samples. When overexpressed, either exogenously or endogenously, DUSP26 promoted growth of the ATC cells. DUSP26 encodes a protein containing a dual-specificity phosphatase domain that can dephosphorylate itself. DUSP26 effectively dephosphorylates p38 and has a little effect on extracellular signal-regulated kinase in ATC cells. DUSP26 protein formed a physical complex with p38, and promoted survival of ATC cells by inhibiting p38-mediated apoptosis. Our findings suggest that DUSP26 may act as an oncogene in ATC, and might be a useful diagnostic marker and therapeutic target of this disease.

[Adverse reaction after use of latanoprost in Japanese glaucoma patients]

PURPOSE

Although latanoprost has proven to have a strong hypotensive effect, some patients show adverse reactions such as eyelid pigmentation, iridial pigmentation, or hypertrichosis. We prospectively investigated these adverse reactions.

SUBJECTS AND METHODS

One hundred and one Japanese glaucoma or ocular hypertension patients were included. Iridial, eyelid, and eyelash photographs were taken before and at 6 months after latanoprost treatment. Increased eyelid pigmentation, iridial pigmentation, eyelash pigmentation, vellus hair of the lid, and hypertrichosis were assessed from these photographs. The correlation between the incidence of these adverse reactions and the time of instillation, type of glaucoma, sex, age, or concomitantly used eye drops, and the overlap of these were evaluated.

RESULTS

Increased pigmentation of the eyelid was found in 6 cases(5.9%), of the iris in 32 cases (31.7%), of the eyelashes in 29 cases (28.7%), vellus hair of the lid in 38 cases(37.6%), and hypertrichosis in 51 cases(50.5%). Pigmentation of the eyelid was more frequently observed in patients who used latanoprost concomitantly (16.7%) than in those who did not use anti-glaucomatous eye drops before latanoprost treatment (1.6%), or in those treated with latanoprost who had switched from other anti-glaucomatous eye drops (6.3%) (p= 0.03).

CONCLUSIONS

The incidence of adverse reactions caused by latanoprost was higher in the eyelashes and iris than in the eyelid.

Use of autologous plasmin during vitrectomy for diabetic maculopathy

PURPOSE

To evaluate the efficacy of autologous plasmin enzyme as an adjunct to vitrectomy in diabetic macular edema.

METHODS

Plasmin derived from autologous blood was injected intravitreally into seven eyes 15 min before vitreous surgery. The development and progression of a posterior vitreous detachment (PVD) was followed, and the time required for vitreous removal was measured. Both pre- and postoperative visual acuities and optical coherence tomography (OCT)-determined macular thickness were measured.

RESULTS

In the seven eyes in which plasmin was used, a PVD developed approximately 5 min after the injection and was confirmed to extend to the far periphery. In all cases, the removal of the vitreous was completed in a shorter time and no complications were observed. A restoration of the shape of the macula was observed in all cases. The visual acuity improved by two or more lines in four eyes, and remained unchanged in the remaining three eyes.

CONCLUSIONS

Autologous plasmin alone will create a full PVD, and eliminates the need for a mechanical creation of a PVD. Thus, plasmin is a safe and effective adjunct to vitreous surgery for the treatment of diabetic maculopathy.

Calpain Inhibition by α-Ketoamide and Cyclic Hemiacetal Inhibitors Revealed by X-ray Crystallography,

Calpains are intracellular calcium-activated cysteine proteases whose unregulated proteolysis following the loss of calcium homeostasis can lead to acute degeneration during ischemic episodes and trauma, as well as Alzheimer's disease and cataract formation. The determination of the crystal structure of the proteolytic core of mu-calpain (muI-II) in a calcium-bound active conformation has made structure-guided design of active site inhibitors feasible. We present here high-resolution crystal structures of rat muI-II complexed with two reversible calpain-specific inhibitors employing cyclic hemiacetal (SNJ-1715) and alpha-ketoamide (SNJ-1945) chemistries that reveal new details about the interactions of inhibitors with this enzyme. The SNJ-1715 complex confirms that the free aldehyde is the reactive species of the cornea-permeable cyclic hemiacetal. The alpha-ketoamide warhead of SNJ-1945 binds with the hydroxyl group of the tetrahedral adduct pointing toward the catalytic histidine rather than the oxyanion hole. The muI-II-SNJ-1945 complex shows residue Glu261 displaced from the S1' site by the inhibitor, resulting in an extended "open" conformation of the domain II gating loop and an unobstructed S1' site. This conformation offers an additional template for structure-based drug design extending to the primed subsites. An important role for the highly conserved Glu261 is proposed.

Comparison between the characteristics of follicular fluid and the developmental competence of bovine oocytes

There are great differences in the developmental competence of oocytes collected from individual cows. Oocytes grow and mature in the follicular fluid (FF). In the present study, characteristics of the FF of each ovary and the developmental competence of enclosed oocytes were investigated, and these data were then compared. A total of 37 pairs of ovaries were collected from beef heifers. The concentration of magnesium (Mg), aspirate aminotransferase (AST), nonesterified fatty acids (NEFA), and lactate dehydrogenase (LDH) in the FF were great compared with serum standard. Several significant correlations among these characteristics were detected. Forty-eight hours after fertilization, the stage of embryo development at an advanced developmental stage (>6 cell stage) is related to the rate of blastulation 8 days after fertilization. In addition, a significantly positive or negative correlation was observed between the developmental competence (the rate of cleavage in the embryo and blastulation) and the concentration of the icterus index (ICT) or blood urea nitrogen (BUN) in the FF. In conclusion, the quality of oocytes is affected by the environment in the follicle, and BUN or ICT is a predictable index of the developmental competence of oocytes.

Fast assessment of acetabular coverage using stereoscopic volume rendering

Previous CT-based methods of measuring acetabular coverage of the femoral head have either been labor-intensive or have required extensive preprocessing of the data prior to visualization. We propose a method of measuring acetabular coverage using stereoscopic digitally reconstructed radiographs that required very little labor or image preprocessing time. Taking a craniocaudal view of the pelvis, we measured both preoperative and postoperative CTs of 10 patients treated with transtrochanteric periacetabular osteotomy. Measurements were then made in both monocular and stereoscopic rendering modes. Our method is fast, easy, and provides an intuitive means of visualizing an orthopedic parameter that is important in the progression of early hip arthritis.

High prevalence of hepatitis B, C and delta virus infections among blood donors in Mongolia

Serum samples obtained from 289 first-time and 114 repeat donors at the Blood Center of Mongolia (MBC) were tested for serological and molecular markers of hepatitis B virus (HBV), hepatitis C virus (HCV), and hepatitis delta virus (HDV) infections. Among the 403 blood donors, 33 (8.2%), 21 (5.2%), and 27 (6.7%) tested positive for hepatitis B surface antigen (HBsAg) and/or HBV DNA, HCV RNA, and HDV RNA, respectively. Collectively, 55 donors were viremic for one or more of these viruses, and included 54 first-time donors (18.7%) and 1 repeat donor (0.9%) (P < 0.0001). One discrepant case with HBsAg detectable only at MBC was negative for HBsAg, HBV DNA and anti-HBc in this study. Four donors who were HCV-viremic in this study were negative for anti-HCV by the MBC method. Further efforts to increase the sensitivity and specificity of the currently-used tests are urgently required in Mongolia. Three donors who were positive for anti-HBc and anti-HDV but negative for HBsAg, had both HBV DNA and HDV RNA. This suggests that introduction of a new anti-HDV serological test is useful for not only HDV screening but also HBV screening of anti-HBc-positive, HBsAg negative donors, considering a possibility of viral interference by coexisting HDV.

p53 prevents maturation of T cell development to the immature CD4-CD8+ stage in Bcl11b-/- mice

Signaling pathways such as the pre-TCR and Wnt pathways regulate alpha/beta T cell differentiation in thymus. Mice lacking an essential component of the pre-TCR exhibit arrest at the (CD4(-)CD8(-)) (CD44(-)CD25(+)) stage (DN3) of thymocyte development, and introduction of p53 deficiency into those mice abrogates this arrest, resulting in transition to the (CD4(+)CD8(+)) double-positive (DP) stage. This paper examines the effect of inactivation of p53 on thymocyte development in Bcl11b(-/-) mice that exhibit arrest at the DN3 or (CD4(-)CD8(+)) immature single-positive (ISP) stage. No DP thymocytes were detected in thymocytes of adoptive transfer experiments in scid mice that were derived from p53(-/-)Bcl11b(-/-) precursors but ISP thymocytes increased in the proportion and in the cell number approximately three times higher than those from Bcl11b(-/-) precursors. Consistently, the level of apoptosis decreased to the level of wild-type precursors. These results suggest that inactivation of p53 is sufficient for DN3 thymocytes to differentiate into the ISP, but not to DP, stage of thymocyte development in Bcl11b(-/-) mice. This provides evidence for a novel p53-mediated checkpoint that regulates the transition from the DN3 to ISP stage of thymocyte development.

Corneal endothelial cell morphology in patients undergoing cataract surgery

PURPOSE

To evaluate the effect of age, gender, axial length, and presence of type II diabetes on corneal endothelial cell morphology in patients undergoing cataract surgery.

METHODS

The corneal endothelial cell morphology was investigated in 1,819 eyes of 1,394 patients before cataract surgery. The parameters examined include cell density, coefficient of variation of cell area, and percentage of hexagonal cells. The effects of age, gender, axial length, and presence of type II diabetes on these parameters were evaluated.

RESULTS

The mean values in endothelial cell density, coefficient of variation of cell area, and percentage of hexagonal cells in all eyes, were 2,543 +/- 254 cells/mm2 (range, 1906-3,252), 0.64 +/- 0.10 (range, 0.34-1.00), and 37.9 +/- 7.1% (range, 17.6-61.7), respectively. Stepwise multiple regression analysis revealed that age was the only explanatory variable to be relevant to corneal endothelial cell density (R = -0.201, p < 0.0001), coefficient of variation of cell area (R = 0.066, p = 0.0046), and percentage of hexagonal cells (R = -0.086, p = 0.0002). The other variables, including gender, axial length, and presence of type II diabetes mellitus, were found to be irrelevant to any of the parameters of corneal endothelial cells.

CONCLUSIONS

Age is the major relevant factor in corneal endothelial cell morphology in patients before cataract surgery.

A strategy for the management of elderly women with primary hyperparathyroidism: a comparison of etidronate therapy with parathyroidectomy

OBJECTIVE

To evaluate the efficacy of etidronate (EHDP) on lumbar spine bone mineral density (LSBMD) and total bone mineral density (TBMD) in elderly women with primary hyperparathyroidism (PHPT), we compared changes in LSBMD and TBMD between patients treated by EHDP therapy and parathyroidectomy (PTX).

SUBJECTS AND METHODS

Twenty-two PHPT patients were enrolled and randomized into two groups; 9 received EHDP and 13 underwent PTX. All patients were followed up for 1 year by measuring LSBMD, TBMD, serum calcium, inorganic phosphate, parathyroid hormone, 1,25-dihydroxyvitamin D, serum alkaline phosphatase, intact osteocalcin, urinary pyridinoline (U(pyd)) and urinary deoxypyridinoline (U(dpd)). The presence of spinal fractures was evaluated by X-ray photography before and after treatment.

RESULTS

EHDP treatment produced a significant increase in LSBMD of 10% compared with pretreatment levels after 1 year (p < 0.03, compared to baseline), while PTX produced a significant increase in LSBMD of 20% compared to pretreatment levels (p < 0.01). However, TBMD remained unchanged for 1 year after both EHDP administration and PTX. Among biochemical bone turnover markers, EHDP administration resulted in significant decreases in alkaline phosphatase by 78%, U(pyd) by 64% and U(dpd) by 37% after 12 months compared with the pretreatment levels (p < 0.05) and intact osteocalcin by 67% after 6 months (p < 0.05). There were no differences in the fracture rate between the EHDP and PTX groups during 1 year.

CONCLUSION

EHDP administration results in a somewhat lower increase in LSBMD than that following PTX and suppresses bone formation and resorption in elderly PHPT patients for 1 year. We conclude that PTX is preferable to EHDP therapy for the management of elderly PHPT patients; however, EHDP administration should also be considered for elderly patients with many complications or who are unfit for surgery.

Myxoid leiomyosarcoma of the gizzard in a broiler chicken

A leiomyosarcoma was found in the gizzard of a 57-day-old female broiler chicken weighing 1.8 kg. Grossly, the tumor mass, 13.0 x 8.5 x 10.0 cm, enveloped the gizzard and had a gelatinous appearance due to the rich production of mucin. Miliary metastatic tumors were noted in the liver. Histopathologically, there was marked production of mucus throughout the tumor tissue, and densely or loosely arranged long spindle-shaped leiomyosarcoma cells proliferated. The tumor cells had a low rate of mitosis, showed slight cellular atypia, and, immunohistochemically, were positive for actin, alpha-smooth muscle actin, and desmin. Electron microscopically, various amounts of microfibrils with focal densities, dense patches, and basal plates were observed.

Lipopolysaccharide stimulates the MyD88-independent pathway and results in activation of IFN-regulatory factor 3 and the expression of a subset of lipopolysaccharide-inducible genes

Bacterial lipopolysaccharide (LPS) triggers innate immune responses through Toll-like receptor (TLR) 4, a member of the TLR family that participates in pathogen recognition. TLRs recruit a cytoplasmic protein, MyD88, upon pathogen recognition, mediating its function for immune responses. Two major pathways for LPS have been suggested in recent studies, which are referred to as MyD88-dependent and -independent pathways. We report in this study the characterization of the MyD88-independent pathway via TLR4. MyD88-deficient cells failed to produce inflammatory cytokines in response to LPS, whereas they responded to LPS by activating IFN-regulatory factor 3 as well as inducing the genes containing IFN-stimulated regulatory elements such as IP-10. In contrast, a lipopeptide that activates TLR2 had no ability to activate IFN-regulatory factor 3. The MyD88-independent pathway was also activated in cells lacking both MyD88 and TNFR-associated factor 6. Thus, TLR4 signaling is composed of at least two distinct pathways, a MyD88-dependent pathway that is critical to the induction of inflammatory cytokines and a MyD88/TNFR-associated factor 6-independent pathway that regulates induction of IP-10.

The novel calpain inhibitor SJA6017 improves functional outcome after delayed administration in a mouse model of diffuse brain injury

A principal mechanism of calcium-mediated neuronal injury is the activation of neutral proteases known as calpains. Proteolytic substrates for calpain include receptor and cytoskeletal proteins, signal transduction enzymes and transcription factors. Recently, calpain inhibitors have been shown to provide benefit in rat models of focal head injury and focal cerebral ischemia. The present study sought to investigate, in experiment 1, the time course of calpain-mediated cytoskeletal injury in a mouse model of diffuse head injury by measuring the 150- and 145-kDa alpha-spectrin breakdown products (SBDP). Secondly, in experiment 2, we examined the effect of early (20 min postinjury) administration of the novel calpain inhibitor SJA6017 on functional outcome measured 24 h following injury and its effect on posttraumatic alpha-spectrin degradation. Lastly, in experiment 3, we examined the effect of delayed (4 or 6 h postinjury) administration of SJA6017 on 24-h postinjury functional outcome. In experiment 1, isoflurane-anesthetized male CF-1 mice (18-22 g) were subjected to a 750 g-cm weight drop-induced injury and were sacrificed for SBDP analysis at postinjury times of 30 min, and 1, 2, 6, 24 and 48 h (plus sham). In experiments 2 and 3, mice were injured as described, and delivered a single tail vein injection of either SJA6017 (0.3, 1, or 3 mg/kg) or vehicle (administered immediately, 4 or 6 h postinjury [3 mg/kg]). Functional outcome was evaluated in both studies, and, in experiment 2, 24-h postinjury assessment of SBDPs was determined. Following injury, the level of SBDP 145 was significantly different from sham at 24 and 48 h in cortical and at 24 h in the hippocampal tissues and at 48 h in the striatum. Immediate postinjury administration of SJA6017 resulted in a dose-related improvement in 24-h functional outcome (p < 0.05 at 3 mg/kg). Significance was maintained after a 4-h delay of the 3 mg/kg, but was lost after a 6-h delay. Despite improvement in functional outcome at 24 h, SJA6017 did not reduce spectrin breakdown in cortical or hippocampal tissues. These results support a role for calpain-mediated neuronal injury and the potential for a practical therapeutic window for calpain inhibition following traumatic brain injury. However, measurements of regional spectrin degradation may not be the most sensitive marker for determining the effects of calpain inhibition.

The TOL plasmid pWW0 xylN gene product from Pseudomonas putida is involved in m-xylene uptake

The upper operon of the TOL plasmid pWW0 of Pseudomonas putida encodes a set of enzymes involved in the conversion of toluene and xylenes to their carboxylic acid derivatives. The last gene of the upper operon, xylN, encodes a 465-amino-acid polypeptide which exhibits significant sequence similarity to FadL, an outer membrane protein involved in fatty acid transport in Escherichia coli. To analyze the role of the xylN gene product, xylN on TOL plasmid pWW0 was disrupted by inserting a kanamycin resistance gene, and the phenotypes of P. putida harboring the wild-type and xylN mutant TOL plasmids were characterized. The growth of P. putida harboring the wild-type TOL plasmid was inhibited by a high concentration of m-xylene, while that of P. putida harboring the xylN mutant TOL plasmid was not. The apparent K(s) value for the oxidation of m-xylene in intact cells of the xylN mutant was fourfold higher than that of the wild-type strain, although the TOL catabolic enzyme activities in cell extracts from the two strains were almost identical. We therefore presume that the xylN gene product is a porin involved in the transport of m-xylene and its analogues across the outer membrane. Western blot analysis confirmed the localization of XylN in the outer membrane.

Numerical analysis of spectra of the Frobenius-Perron operator of a noisy one-dimensional mapping: toward a theory of stochastic bifurcations

A different method to detect the stochastic bifurcation point of a one-dimensional mapping in the presence of noise is proposed. This method analyzes the eigenvalues and eigenfunctions of the noisy Frobenius-Perron operator. The invariant density or the eigenfunction of the eigenvalue 1 of the operator possesses "static" information of the noisy one-dimensional dynamics while the other eigenvalues and eigenfunctions have "dynamic" information. Clear bifurcation phenomena have been observed in a noisy sine-circle map and both stochastic saddle-node and period-doubling bifurcation points have been successfully defined in terms of the eigenvalues.

Mammalian homologue of E. coli Ras-like GTPase (ERA) is a possible apoptosis regulator with RNA binding activity

BACKGROUND

ERA (Escherichia coli Ras-like protein) is an E. coli GTP binding protein that is essential for proliferation. A DNA database search suggests that homologous sequences with ERA exist in various organisms including human, mouse, Drosophila, Caenorhabditis elegans and Antirrhinum majus. However, the physiological function of eukaryotic ERA-like proteins is not known.

RESULTS

We have cloned cDNAs encoding the entire coding region of a human homologue (H-ERA) and a mouse homologue (M-ERA) of ERA. The mammalian homologue of ERA consists of a typical GTPase/GTP-binding domain and a putative K homology (KH) domain, which is known as an RNA binding domain. We performed transfection experiments with wild-type H-ERA or various H-ERA mutants. H-ERA possessing the amino acid substitution mutation into the GTPase domain induced apoptosis of HeLa cells, which was blocked by Bcl-2 expression. Deletion of the C-terminus, which contains a part of the KH domain, alleviated apoptosis by the H-ERA mutant, suggesting the importance of this domain in the function of H-ERA. We have also shown the RNA binding activity of H-ERA by pull-down experiments using RNA homopolymer immobilized on beads or recombinant H-ERA proteins.

CONCLUSION

Our data suggest that H-ERA plays an important role in the regulation of apoptotic signalling with its GTPase/GTP binding domain.

Image restoration using the Q-Ising spin glass

We investigate static and dynamic properties of gray-scale image restoration by making use of the Q-Ising spin glass model, whose ladder symmetry allows us to take in account the distance between two spins. We thus give an explicit expression of the Hamming distance between the original and restored images as a function of the hyperparameters in the mean field limit. Finally, numerical simulations for real-world pictures are carried out to prove the efficiency of our model.

Mice containing a human chromosome 21 model behavioral impairment and cardiac anomalies of Down's syndrome

Trisomy 21 (Ts21) is the most common live-born human aneuploidy; it results in a constellation of features known as Down's syndrome (DS). Ts21 is the most frequent cause of congenital heart defects and the leading genetic cause of mental retardation. To investigate the gene dosage effects of an extra copy of human chromosome 21 (Chr 21) on various phenotypes, we used microcell-mediated chromosome transfer to create embryonic stem (ES) cells containing Chr 21. ES cell lines retaining Chr 21 as an independent chromosome were used to produce chimeric mice with a substantial contribution from Chr 21-containing cells. Fluorescence in situ hybridization and PCR-based DNA analysis revealed that Chr 21 was substationally intact but had sustained a small deletion. The freely segregating Chr 21 was lost during development in some tissues, resulting in a panel of chimeric mice with various mosaicism as regards retention of the Chr 21. These chimeric mice showed a high correlation between retention of Chr 21 in the brain and impairment in learning or emotional behavior by open-field, contextual fear conditioning and forced swim tests. Hypoplastic thymus and cardiac defects, i.e. double outlet right ventricle and riding aorta, were observed in a considerable number of chimeric mouse fetuses with a high contribution of Chr 21. These chimeric mice mimic a wide variety of phenotypic traits of DS, revealing the utility of mice containing Chr 21 as unique models for DS and for the identification of genes responsible for DS.

Occurrences of candidiasis in a Fisher's lovebird and a budgerigar

Two cage birds, a two-month-old Fisher's lovebird (Agapornis fischeri) and a one-year-old budgerigar (Melopsittacus undulatus), manifested clinical symptoms with general weakness, loss of appetite and ruffled feathers, then died. Pathological findings revealed a large quantity of yellowish-white pseudomembrane on the mucosal membrane of the esophagus and crop in these two birds. Histopathologically, blastospores (5.5 microm long x 3.4 microm wide) and pseudohyphae were detected in the lesions of conspicuous parakeratosis and moderate acanthosis in the stratified squamous epithelium. These two birds were diagnosed as having had candidiasis.

A conserved imprinting control region at the HYMAI/ZAC domain is implicated in transient neonatal diabetes mellitus

Transient neonatal diabetes mellitus (TNDM) is associated with intra-uterine growth retardation, dehydration and a lack of insulin. Some TNDM patients exhibit paternal uniparental disomy (UPD) of chromosome 6q24, where at least two imprinted genes, HYMAI and ZAC, have so far been characterized. Here we show that the differentially methylated CpG island that partially overlaps mZac1 and mHymai at the syntenic mouse locus is a likely imprinting control region (ICR) for the approximately 120--200 kb domain. The region is unmethylated in sperm but probably methylated in oocytes, a difference that persists between parental alleles throughout pre- and post-implantation development. We also show that within this ICR, there is a region that exhibits a high degree of homology between mouse and human. Using a reporter expression assay, we demonstrate that this conserved region acts as a strong transcriptional repressor when methylated. Finally, we provide in vivo evidence that in the majority of TNDM patients with a normal karyotype, there is a loss of methylation within the highly homologous region. We propose that this ICR regulates expression of imprinted genes within the domain; epigenetic or genetic mutations of this region probably result in TNDM, possibly by affecting expression of ZAC in the pancreas and/or the pituitary.

Effects of stimulus intensity on sound localization in the horizontal and upper-hemispheric median plane

Sound lateralization ability with headphones is known to be affected by stimulus intensity. However, there have been few studies on sound localization with loudspeakers in free field from the standpoint of stimulus intensity. The aim of this study is to obtain basic data for the tests with normal hearing and hearing-impaired subjects, and for the fitting of a hearing aid. The author investigated the relationship between stimulus intensities and sound localization ability of the broadband noise and pure tone bursts delivered in the horizontal and upper-hemispheric median planes. Subjects were ten volunteers, 5 males and 5 females, at the age of 18-19 years, with normal hearing. The results showed well how subjects perceived directions at all stimulus intensities. The percentage of correct response (%correct) for broadband noise stimuli was maximum at the intensity from 40 to 70 dB SPL (sound pressure level), and was minimum at 0 to 20 dB SPL in both the horizontal plane and the upper-hemispheric median plane. At lower stimulus intensity, examinee could not judge the direction, even if they could hear the stimuli. For pure tone bursts stimuli in the upper-hemispheric median plane, %correct was low irrespective of stimulus intensity.

Construction of 700 human/mouse A9 monochromosomal hybrids and analysis of imprinted genes on human chromosome 6

As an in vitro assay system for the identification of human imprinted genes, a library of human/mouse A9 monochromosomal hybrids containing a single, intact bsr-tagged human chromosome of known parental origin, derived from normal human fibroblasts, has been previously generated by microcell-mediated chromosome transfer (MMCT). To supplement this assay system, we constructed additional 700 A9 monochromosomal hybrids, using a pSTneo or pPGKneo selection marker. To validate the A9 hybrids, we screened them with chromosome-specific polymorphic markers, and identified the hybrids containing either human chromosome 6, 7, 14, 18, or 21 of known parental origin. Matching paternal and maternal chromosome pairs of A9 hybrids were identified for chromosomes 6, 7, 14, and 18. The paternal-specific expression of ZAC (zinc finger protein, which regulates apoptosis and cell cycle arrest) and HYMAI (hydatidiform mole-associated and imprinted transcript), and the maternal-specific methylation of a CpG island within an imprinted domain on human chromosome 6q24, were maintained in A9 hybrids. For an example, we profiled the expression of expressed sequence tags (ESTs) and the methylation of CpG islands in the 300-kb imprinted domain around 6q24, which may be associated with cancers and transient neonatal diabetes mellitus (TNDM). Thus, the 700 A9 hybrids should be useful for various aspects of imprinting studies.