Birefringence-derived artifact in optical coherence tomography imaging of the lamina cribrosa in eyes with glaucoma

We investigated birefringence-derived artifacts that potentially mimic focal defects of the lamina cribrosa (focal LC defects) in optical coherence tomography (OCT) imaging of eyes with glaucoma. This study included 74 eyes of 48 patients with glaucoma. Five horizontal line B-scan images of the optic disc were obtained using commercial swept-source OCT. From a dataset of prototype swept-source polarization-diversity OCT, we calculated the following types of OCT images: polarization-dependent, polarization-dependent attenuation-coefficient, polarization-independent, and polarization-independent attenuation-coefficient. We assessed the commercial OCT images for the presence of birefringence-derived artifacts by comparison with the polarization-diversity OCT images. Commercial OCT showed suggestive findings of focal LC defects in 17 of 74 eyes. Reevaluation using polarization-independent OCT revealed that the focal LC defects in one of 17 eyes (5.9%) were actually birefringence-derived artifacts. This study demonstrated the existence of birefringence-derived artifacts mimicking focal LC defects in commercial OCT imaging and indicated that polarization-diversity OCT is an effective tool to evaluate the presence of these artifacts.

Synthesizing the degree of polarization uniformity from non-polarization-sensitive optical coherence tomography signals using a neural network

Degree of polarization uniformity (DOPU) imaging obtained by polarization-sensitive optical coherence tomography (PS-OCT) has the potential to provide biomarkers for retinal diseases. It highlights abnormalities in the retinal pigment epithelium that are not always clear in the OCT intensity images. However, a PS-OCT system is more complicated than conventional OCT. We present a neural-network-based approach to estimate the DOPU from standard OCT images. DOPU images were used to train a neural network to synthesize the DOPU from single-polarization-component OCT intensity images. DOPU images were then synthesized by the neural network, and the clinical findings from ground truth DOPU and synthesized DOPU were compared. There is a good agreement in the findings for RPE abnormalities: recall was 0.869 and precision was 0.920 for 20 cases with retinal diseases. In five cases of healthy volunteers, no abnormalities were found in either the synthesized or ground truth DOPU images. The proposed neural-network-based DOPU synthesis method demonstrates the potential of extending the features of retinal non-PS OCT.

Extending field-of-view of retinal imaging by optical coherence tomography using convolutional Lissajous and slow scan patterns

Optical coherence tomography (OCT) is a high-speed non-invasive cross-sectional imaging technique. Although its imaging speed is high, three-dimensional high-spatial-sampling-density imaging of in vivo tissues with a wide field-of-view (FOV) is challenging. We employed convolved Lissajous and slow circular scanning patterns to extend the FOV of retinal OCT imaging with a 1-µm, 100-kHz-sweep-rate swept-source OCT prototype system. Displacements of sampling points due to eye movements are corrected by post-processing based on a Lissajous scan. Wide FOV three-dimensional retinal imaging with high sampling density and motion correction is achieved. Three-dimensional structures obtained using repeated imaging sessions of a healthy volunteer and two patients showed good agreement. The demonstrated technique will extend the FOV of simple point-scanning OCT, such as commercial ophthalmic OCT devices, without sacrificing sampling density.

Evaluation of retinal pigment epithelium changes in serous pigment epithelial detachment in age-related macular degeneration

The purpose of this study was to quantitatively evaluate retinal pigment epithelium (RPE) changes in serous pigment epithelial detachment (PED) among patients with age-related macular degeneration by means of prototype multi-contrast optical coherence tomography (OCT), which is capable of simultaneous collection of OCT angiography, polarization-sensitive OCT, and standard OCT images. We evaluated 26 eyes of 21 patients with serous PED. RPE-melanin OCT images were calculated from the multi-contrast OCT dataset and compared with near-infrared autofluorescence images. An active RPE lesion was defined as an area of thickened RPE-melanin (≥ 70 μm; RPE₇₀) on RPE-melanin OCT. Each PED area was divided into peak and slope regions. RPE₇₀ area ratios were compared with the maximum PED height, PED area, PED volume, and slope area ratio (area of slope region/area of whole PED). RPE-melanin OCT images were consistent with near-infrared autofluorescence images. The RPE₇₀ area ratio in the slope region was significantly negatively correlated with the slope area ratio. Development of active RPE lesions in the slope region was correlated with the PED configuration. Multi-contrast OCT is useful for objective evaluation of changes in the RPE in patients with age-related macular degeneration.

Accurately motion-corrected Lissajous OCT with multi-type image registration

Passive motion correction methods for optical coherence tomography (OCT) use image registration to estimate eye movements. To improve motion correction, a multi-image cross-correlation that employs spatial features in different image types is introduced. Lateral motion correction using en face OCT and OCT-A projections on Lissajous-scanned OCT data is applied. Motion correction using OCT-A projection of whole depth and OCT amplitude, OCT logarithmic intensity, and OCT maximum intensity projections were evaluated in retinal imaging with 76 patients. The proposed method was compared with motion correction using OCT-A projection of whole depth. The comparison shows improvements in the image quality of motion-corrected superficial OCT-A images and image registration.

Evaluation of Retinal Pigment Epithelium Layer Change in Vogt-Koyanagi-Harada Disease With Multicontrast Optical Coherence Tomography

Purpose

Clinical evaluation of retinal pigment epithelium (RPE) change is important for the therapeutic management of chronic Vogt-Koyanagi-Harada (VKH) disease. We evaluated long-term change in the RPE layer in VKH disease, using near-infrared (NIR; 817 nm) images and autofluorescence images at 488 nm (short-wavelength [SW]-AF) and 785 nm (NIR-AF), and compared those images with images from multicontrast optical coherence tomography (MC-OCT). MC-OCT is capable of simultaneous measurement of OCT angiography, polarization-sensitive OCT, and standard OCT.

Methods

We evaluated 24 eyes of 12 patients with chronic VKH disease. RPE changes were assessed using NIR, NIR-AF, SW-AF, and MC-OCT imaging performed from 6 to 48 months after disease onset. RPE-melanin-specific contrast OCT images were calculated using the dataset from MC-OCT.

Results

Granular hyper NIR-AF lesions were observed in 8 of 24 eyes (33%). Eyes with granular hyper NIR-AF lesions showed a sunset glow fundus appearance significantly more frequently than did eyes without such lesions (P < 0.0001). MC-OCT imaging confirmed that there was melanin accumulation at the RPE-Bruch's membrane band at the location of granular hyper NIR-AF lesions. Granular hyper NIR-AF lesions were unclear in SW-AF and color fundus images, but clearly detectable in NIR images. Areas of hyper NIR-AF lesions gradually decreased over time.

Conclusions

Melanin accumulation in the RPE layer at the location of granular hyper NIR-AF lesions was confirmed with MC-OCT imaging. Long-term follow-up showed the reversible nature of this accumulation. MC-OCT is useful for the evaluation of change at the RPE layer in chronic VKH disease.

Presence of intimate family and cancer screening behavior: a cross-sectional study of 4237 workers

Background

Presence of intimate family is considered as one of the related factors of health behaviors. The study aim was to clarify the relationship between the presence of significant others and having a colorectal cancer screening.

Methods

This study used data of baseline survey of intervention study regarding breast cancer screening at worksites. A total of 6827 workers, aged 40 and over of the retail company, were required to fill out a self-administrated questionnaire related to cancer screening. the intimate family was defined as a person’s spouse or partner and children. Logistic regression analyses were performed to estimate odds ratios [ORs] and 95% confidence intervals [CIs] of undergoing an annual screening for colorectal cancer by the presence of spouse or partner adjusting for age. The same analysis was performed regarding the presence of children.

Results

Response rates were 70% in men and 71% in women. After excluding participants with a past history of cancer and lack of information about colorectal cancer screening or the presence of significant others, 4203 remained for the analyses. A total of 1777 participants reported that they had undergone screening for colorectal cancer within a year (42% in men and 42% in women). Screening rates of participants with/without a spouse were 45% and 30% in men, 44% and 38% in women. Screening rates of participants with/without children were 45% and 33% in men, 43% and 38% in women. ORs of undergoing annual colorectal cancer screening by the presence of spouse were 1.8 (1.3-2.5) in men and 1.3 (1.1-1.5) in women. ORs by the presence of children were 1.6 (1.2-2.1) in men and 1.1 (0.9-1.3) in women.

Conclusions

This study indicated that health behavior in cancer screening could be affected by having a spouse in both men and women. The presence of children positively related in men. Male workers with children might be under some pressure to keep their health, from a sense of responsibility of main income earner.

Key messages

Health behavior in cancer screening could be affected by having a spouse. Health behavior in cancer screening could be affected by having a child only in men.

Clinical multi-functional OCT for retinal imaging

A compact clinical prototype multi-functional optical coherence tomography (OCT) device for the posterior human eye has been developed. This compact Jones-matrix OCT (JM-OCT) device integrates all components into a single package. Multiple image functions, i.e., scattering intensity, OCT angiography, and the degree of polarization uniformity, are obtained. The device has the capability for measuring local birefringence. Multi-functional imaging of several eyes with age-related macular degeneration is demonstrated. The compact JM-OCT device will be useful for the in vivo non-invasive investigation of abnormal tissues.

Compression optical coherence elastography with two-dimensional displacement measurement and local deformation visualization

Current compression-based optical coherence elastography (OCE) only measures the axial displacement of a tissue, although the tissue also undergoes lateral displacement and microstructural alteration by the compression. In this Letter, we demonstrate a new compression-based OCE method that visualizes not only axial displacement, but also lateral displacement and microstructural decorrelation (MSD). This method employs complex correlation-based displacement and MSD measurements. It is implemented in a swept-source optical coherence tomography system with an active submicrometer compression. The performance of the method was demonstrated by measuring the porcine carotid artery and esophagus. The results showed significant axial and lateral displacements in the tissues by compression. An MSD map demonstrates high-contrast mechanical-property imaging.

Clinical prototype of pigment and flow imaging optical coherence tomography for posterior eye investigation

Measurements of the randomness of polarization (RP) obtained using polarization-sensitive optical coherence tomography (PS-OCT) are applied in several applications, and RP is attractive for posterior eye imaging. The addition of RP without retardation requires a minimal extension to standard OCT; therefore, we developed a prototype OCT system with a simplified scheme for RP measurement. A compact polarization-diversity receiver module is the only required hardware extension to a standard OCT system. All components were packed into the retinal scanning head. The degree-of-polarization uniformity and complex-decorrelation based OCT angiography were calculated using noise-corrected algorithms that accounted for the depth-dependent noise power. The structure, melanin, and blood flow distribution imaging of in vivo human eyes were demonstrated. Pathological eye imaging shows potential applications for combinations of these contrasts.

Pixel-wise segmentation of severely pathologic retinal pigment epithelium and choroidal stroma using multi-contrast Jones matrix optical coherence tomography

Tissue segmentation of retinal optical coherence tomography (OCT) is widely used in ophthalmic diagnosis. However, its performance in severe pathologic cases is still insufficient. We propose a pixel-wise segmentation method that uses the multi-contrast measurement capability of Jones matrix OCT (JM-OCT). This method is applicable to both normal and pathologic retinal pigment epithelium (RPE) and choroidal stroma. In this method, "features," which are sensitive to specific tissues of interest, are synthesized by combining the multi-contrast images of JM-OCT, including attenuation coefficient, degree-of-polarization-uniformity, and OCT angiography. The tissue segmentation is done by simple thresholding of the feature. Compared with conventional segmentation methods for pathologic maculae, the proposed method is less computationally intensive. The segmentation method was validated by applying it to images from normal and severely pathologic cases. The segmentation results enabled the development of several types of en face visualizations, including melano-layer thickness maps, RPE elevation maps, choroidal thickness maps, and choroidal stromal attenuation coefficient maps. These facilitate close examination of macular pathology. The melano-layer thickness map is very similar to a near infrared fundus autofluorescence image, so the map can be used to identify the source of a hyper-autofluorescent signal.

The Role of Oral Kinesthesia in the Determination of the Swallowing Threshold

The interdental dimension discrimination (IDD) ability and the swallowing threshold were evaluated at the sitting and supine positions. The difference in the magnitude of mis-estimation of IDD and that in the swallowing threshold between the two positions was significantly correlated. These results indicate some influence of the IDD in the determination of the swallowing threshold.

Atomic-scale imaging of individual dopant atoms in a buried interface

Determining the atomic structure of internal interfaces in materials and devices is critical to understanding their functional properties. Interfacial doping is one promising technique for controlling interfacial properties at the atomic scale, but it is still a major challenge to directly characterize individual dopant atoms within buried crystalline interfaces. Here, we demonstrate atomic-scale plan-view observation of a buried crystalline interface (an yttrium-doped alumina high-angle grain boundary) using aberration-corrected Z-contrast scanning transmission electron microscopy. The focused electron beam transmitted through the off-axis crystals clearly highlights the individual yttrium atoms located on the monoatomic layer interface plane. Not only is their unique two-dimensional ordered positioning directly revealed with atomic precision, but local disordering at the single-atom level, which has never been detected by the conventional approaches, is also uncovered. The ability to directly probe individual atoms within buried interface structures adds new dimensions to the atomic-scale characterization of internal interfaces and other defect structures in many advanced materials and devices.

Expression of cyclooxygenase-2, P-glycoprotein and multi-drug resistance-associated protein in canine transitional cell carcinoma

Cyclooxygenase-2 (COX-2), P-glycoprotein (P-gp) and multi-drug resistance-associated protein (MRP) are considered important tumor-associated proteins in humans and dogs. In the present study, we immunohistochemically evaluated the expression of these proteins in canine patients with transitional cell carcinoma (TCC). Of 52 cases, 30 (57.7%) were positive for COX-2, 40 (76.9%) for P-gp, and only 10 (19.2%) for MRP. In addition, 27 samples (27/52, 51.9%) were positive for two markers, while 3 (5.7%) and 5 (9.6%) cases were positive and negative, respectively, for all three markers. No significant correlations were seen for COX-2 and P-gp on Fisher's exact test and Mann-Whitney's test, but a significance was seen on Spearman's rank correlation analysis using the IHC scoring system (P=0.043). These results suggest that P-gp expression is induced by overexpression of COX-2 in canine patients with TCC.

Cryopreservation of wild mouse spermatozoa

Spermatozoa of wild mice from China, Czechoslovakia, Denmark, India, Japan and Switzerland were frozen and stored at -196 degrees C. After thawing, intact oocytes were inseminated in vitro with relatively high motility frozen-thawed mouse spermatozoa from Czechoslovakia, Denmark and India, while oocytes with a partially dissected zona were inseminated with low motility frozen-thawed spermatozoa from China, Japan and Switzerland. Embryos developing to the 2-cell stage from oocytes fertilized with frozen-thawed spermatozoa were transferred to the oviducts of female recipients on the first day of pseudopregnancy (day when a vaginal plug was confirmed). Successful embryo development to the 2-cell stage was 46 to 67%. Offspring resulted from 17 to 51% of these transferred 2-cell embryos.

Gender-related differences in prolactin secretion in pituitary prolactinomas

In pituitary prolactinomas, serum prolactin (PRL) levels usually parallel the tumor size. We conducted a retrospective study to determine differences in PRL production between men and women with prolactinomas. A total of 51 patients, 16 men and 35 women, was studied. We investigated clinical, endocrinological, radiological and histological findings, and estimated the tumor volume (TV) by high-resolution magnetic resonance imaging (MRI). Correlation between PRL level and TV was low in men (R=0.458), in contrast to women (R=0.953), c. Men with prolactinomas showed predominance of large tumors (P=0.0009) with high PRL levels (P=0.0009) and had greater tendencies for cyst formation (P=0.0047). Large prolactinomas tended to be accompanied by cyst(s) (P=0.0051) and hemorrhage ( P=0.0015), both of which were associated with reduced PRL secretion (P=0.0004 and P<0.0001, respectively). When the volume of the cysts and hemorrhage was subtracted from the total TV, correlation between PRL level and TV became greater (R=0.905) with no gender difference. Histological examination demonstrated a sparsely granulated type of lactotroph adenoma with occasional fibrosis, particularly in tumors with hemorrhage and cysts. Although a significant discrepancy between PRL level and TV may exist in prolactinomas when intratumoral hemorrhage and/or cysts are present, there is no essential difference in PRL secretion between the sexes.

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.

HNF-1 regulates the liver-specific transcription of the chipmunk HP-20 gene

The chipmunk hibernation-specific protein HP-20 is a component of the 140 kDa complex that drastically decreases in the blood during hibernation, and its gene is expressed specifically in the liver. To reveal molecular mechanisms underlying the liver-specific transcription of the HP-20 gene, we isolated chipmunk HP-20 genomic clones. The HP-20 gene spans approximately 6 kb, and consists of three exons. The transcription start site, as determined by 5' RACE-PCR analysis, was found to be 160 bp upstream of the translation initiation codon. Transient transfection studies in HepG2 cells revealed that the 57 bp 5' flanking sequence was sufficient for the liver-specific promoter activity. A database search revealed that this region contains a potential binding site for hepatocyte nuclear factor-1 (HNF-1). In a gel retardation assay, in vitro-synthesized HNF-1 bound to the 5' flanking sequence from -52 to -26. A similar shifted band was also observed with HepG2 nuclear extracts, and this complex was super-shifted by an anti-(HNF-1) Ig. When transfected into COS-7 cells, HNF-1 transactivated transcription from the HP-20 gene promoter, and this activity was abolished by a mutation of the HNF-1 binding site, indicating that HNF-1 plays an important role in HP-20 gene expression.

Novel gastroinsular axis involving a gastric transmural glucose flux and vagal mediation

To determine whether the appearance of nutrients into the gastric lumen per se provokes insulin secretion, glucose solution was instilled into the pylorus-cannulated stomach via an orogastric tube in anesthetized dogs. When 200 ml of 0, 5, 10, and 20% glucose solution were sequentially instilled, transgastric gradients (TGG) of plasma glucose concentration across the fundus [short gastric vein (SGV) - femoral artery, TGG(SGV)] and insulin levels in the superior pancreaticoduodenal vein (SPDV) increased stepwise. Upon instillation of 300 ml of 10% glucose, but not 1.8% saline, for 12 min followed by 48-min spontaneous drainage via the cannula (n = 5 each), TGG(SGV) and insulin levels in the SPDV increased concomitantly and significantly by 0.95 mM and 1,334 pM (mean), respectively, regardless of unaltered arterial glucose levels. The amount of secreted insulin (area under the curve) significantly correlated with the maximum TGG(SGV) (r = 0.693). In selectively gastric-vagotomized dogs (n = 5), insulin levels in the SPDV did not increase upon instillation despite a TGG(SGV) rise comparable to that in normal dogs. These results indicate that intragastric glucose appearance provokes vagus-mediated insulin secretion probably related to the transfundic glucose flux, suggesting the presence of a novel neurogenic gastroinsular axis.

Targeted disruption of Na+/Ca2+ exchanger gene leads to cardiomyocyte apoptosis and defects in heartbeat

Ca(2+), which enters cardiac myocytes through voltage-dependent Ca(2+) channels during excitation, is extruded from myocytes primarily by the Na(+)/Ca(2+) exchanger (NCX1) during relaxation. The increase in intracellular Ca(2+) concentration in myocytes by digitalis treatment and after ischemia/reperfusion is also thought to result from the reverse mode of the Na(+)/Ca(2+) exchange mechanism. However, the precise roles of the NCX1 are still unclear because of the lack of its specific inhibitors. We generated Ncx1-deficient mice by gene targeting to determine the in vivo function of the exchanger. Homozygous Ncx1-deficient mice died between embryonic days 9 and 10. Their hearts did not beat, and cardiac myocytes showed apoptosis. No forward mode or reverse mode of the Na(+)/Ca(2+) exchange activity was detected in null mutant hearts. The Na(+)-dependent Ca(2+) exchange activity as well as protein content of NCX1 were decreased by approximately 50% in the heart, kidney, aorta, and smooth muscle cells of the heterozygous mice, and tension development of the aortic ring in Na(+)-free solution was markedly impaired in heterozygous mice. These findings suggest that NCX1 is required for heartbeats and survival of cardiac myocytes in embryos and plays critical roles in Na(+)-dependent Ca(2+) handling in the heart and aorta.

The primary structure of the subunit in Bacillus thermoamyloliquefaciens KP1071 molecular weight 540,000 homohexameric alpha-glucosidase II belonging to the glycosyl hydrolase family 31

The gene that coded for the subunit of an molecular weight (Mr) 540,000 homohexameric alpha-glucosidase II (alpha-D-glucoside glucohydrolase, EC 3.2.1.20) produced by Bacillus thermoamyloliquefaciens KP1071 (FERM-P8477) growing at 30 to 66 degrees C was expressed in Escherichia coli HB101. The resulting homohexameric enzyme had a half-life of 10 min at 80 degrees C. Its purification and characterization showed that the enzyme was identical with the native one except for the latter deleting 7 N-terminal residues found in the former. The primary sequence of the subunit with 787 residues and an Mr of 91,070 deduced from the gene was 24-34% identical to the corresponding sequences of 15 alpha-glucosidases in the glycosyl hydrolase family 31 from 14 eukaryotic origins and the archaeon Sulfolobus solfataricus 98/2. From the sequence analysis by the neural network method of Rost and Sander [Rost, B. and Sander, C., Proteins: Struct. Funct. Genet., 19, 55-72 (1994)], we inferred that alpha-glucosidase II might make each subunit of 3 secondary structural regions, i.e., one N-terminal beta region, one central alpha/beta region with two catalytic residues Asp407 and Asp484, and one C-terminal beta region.

Interleukin-4-dependent induction of preproenkephalin in antigen-specific T helper-type 2 (Th2) cells

Naive Th cells obtained from OVA(323-339)-specific DO11.10 TCR-Tg mice did not express preproenkephalin (PPE) mRNA. However, culture of naive Th cells with OVA(323-339) peptide (OVA-pep) plus IL-2 under Th2-inducing conditions for 7 days resulted in an induction of PPE mRNA. The PPE mRNA was also induced by culturing with OVA-pep plus IL-2 (neutral condition). However, PPE mRNA induction under neutral conditions was totally abrogated by addition of anti-IL-4 mAb. The existence of methionine-enkephalin was also demonstrated in peptidase-digested peptides derived from Th2 cell lysate. These results demonstrate that IL-4 is a critical factor for the induction of PPE mRNA in freshly expanded antigen-specific Th2 cells.

Synthesis of oligodeoxyribonucleotide bearing 2'-S-alkyl residue and its effect on the duplex stability

2'-Deoxy-2'-S-hexyluridine derivative was synthesized from 2,2'-anhydrouridine and 1-hexanethiol and incorporated into an oligodeoxyribonucleotide. The thermal stability of the duplexes formed by the 2'-S-hexyl modified ODN with either the complementary DNA or RNA strand was decreased compared to the unmodified counterparts.

[Multiple cavities in myocardium of left ventricle after irradiation therapy for breast cancer: a case report]

A 68-year-old woman was admitted to our hospital with congestive heart failure. She had been diagnosed with hypertrophic cardiomyopathy 12 years ago in another hospital. She had received irradiation therapy for left breast cancer 33 years ago after resection of her left breast. Echocardiography revealed left ventricular hypertrophy and wall motion hypokinesis, and multiple cavities in the myocardium of the left ventricle, interventricular septum, and anterior wall. Some cavities were observed to connect to the left ventricular cavity and Doppler echocardiography showed slow velocity flows in them different from that of the coronary artery. The pathologic diagnosis was severe sclerosis of the left coronary artery, especially the left descending artery and its branch, which was the area with irradiation. Histopathology revealed sclerotic changes of the coronary artery causing acute and chronic myocardial infarction, and incomplete regeneration and hypertrophy of cardiac cells. There was no sign of hypertrophic cardiomyopathy. Myocardial degeneration and deciduation were present next to the cavities connected to left ventricle-like fistulas.

Severe osteopetrosis, defective interleukin-1 signalling and lymph node organogenesis in TRAF6-deficient mice

BACKGROUND

TRAF6, a member of the tumour necrosis factor receptor-associated factor family, was first identified as a transducer of CD40 and interleukin-1 receptor (IL-1R) signals based on the interaction of TRAF6 with the cytoplasmic tail of CD40 and with the IL-1R associated kinase in vitro. However, the functions of TRAF6 in vivo remain unidentified.

RESULTS

We show that TRAF6-/- mice exhibit severe osteopetrosis and are defective in osteoclast formation. In vitro culture experiments revealed that osteoclast precursor cells derived from TRAF6-/- mice are unable to differentiate to functional osteoclasts in response to osteoclast differentiation factor (ODF). In bone marrow of TRAF6-/- mice, the number of sIgM+B220+ immature B cells is markedly reduced while the ratio of proB to preB cells is not affected. In contrast, development of thymocytes is not affected. Furthermore, TRAF6-/- mice are defective in lymph node organogenesis and IL-1 signalling in thymocytes.

CONCLUSIONS

The results identify TRAF6 as an essential component of ODF signalling pathway, and also show that TRAF6 plays pivotal roles in immune and inflammatory systems in vivo.

Two differently regulated nuclear factor kappaB activation pathways triggered by the cytoplasmic tail of CD40

CD40 signaling modulates the immune response at least in part by activation of nuclear factor kappaB (NFkappaB). It has been shown that two distinct domains in the CD40 cytoplasmic tail (cyt), namely cyt-N and cyt-C, independently activate NFkappaB. Although four members of the tumor necrosis factor receptor-associated factor (TRAF) family, including TRAF2, TRAF3, TRAF5, and TRAF6, bind to the CD40 cyt, how each TRAF protein contributes to the NFkappaB activation by CD40 is not clear. Here we report that TRAF2, TRAF3, and TRAF5 bind cyt-C, whereas TRAF6 binds cyt-N. cyt-N is conserved poorly between human and mouse CD40, while cyt-C is highly conserved. However, single aa substitution of Glu-235 in cyt-N of human CD40 with Ala abolishes the binding of TRAF6 to cyt-N and NFkappaB activation by cyt-N. Conservation of this Glu between mouse and human CD40 strongly suggests that TRAF6 could link cyt-N to signals essential for CD40-mediated immune response. Furthermore, NFkappaB activation by cyt-C is inhibited by a kinase-negative form of NFkappaB-inducing kinase more efficiently than that by cyt-N, consistent with the result that NFkappaB activation by TRAF2 and TRAF5 is inhibited by a kinase-negative form of NFkappaB-inducing kinase more efficiently than that by TRAF6. These results indicate that NFkappaB activating signals emanating from cyt-N and cyt-C are mediated by the different members of the TRAF family and could be regulated in a distinct manner.

Synthesis and biological evaluation of 1alpha,24-dihydroxy-25-nitrovitamin D3

1Alpha,24(R)Dihydroxy-25-nitrovitamin D3 1 and 1alpha,24(S)-dihydroxy-25-nitrovitamin D3 2 were synthesized using the palladium-catalyzed alkylative enyne cyclization reaction. Their biological properties were studied based on VDR binding affinity and HL-60 cell differentiation activity.

Endothelin ET(B) receptor-mediated action on systemic and renal hemodynamics and urine formation in deoxycorticosterone acetate-salt-induced hypertensive rats

The pathophysiological role of endothelin ET(B) receptor-mediated action on systemic and renal hemodynamics and urine formation in deoxYcorticosterone acetate (DOCA)-salt hypertensive rats was investigated. An intravenous bolus injection of a selective ET(B) receptor antagonist, BQ788 (1 mg/kg), produced a significant increase in mean arterial pressure (MAP) of DOCA-salt treated rats, whereas the agent-induced increase in MAP was less marked in normotensive sham rats. Administration of BQ788 caused a significant and sustained reduction in renal blood flow both in DOCA-salt and sham rats. No marked effects were observed on urine formation in both groups. Alternatively, a selective ET(A) receptor antagonist, FR139317 (10 mg/kg), produced a potent hypotensive effect, accompanied by significant renal vasodilation in DOCA-salt hypertensive rats, but these effects were partially reversed by the subsequent administration of BQ788. When renal perfusion pressure was protected from FR139317-induced hypotension by an aortic clamp, significant diuresis and natriuresis were observed, events partially reversed by the subsequent administration of BQ788. Our results indicate that the ET(B) receptor-mediated action tonically functions as a hypotensive and a renal vasodilatory factor and that these effects seem to be up-regulated in DOCA-salt hypertension. We also suggest that the ET(A) receptor blockade in DOCA-salt hypertensive rats unmasks the ET(B) receptor-mediated action which partially contributes to the antihypertensive effect induced by FR139317.

Cloning and characterization of a cDNA encoding the human homolog of tumor necrosis factor receptor-associated factor 5 (TRAF5)

A cDNA encoding the human homolog of the tumor necrosis factor receptor-associated factor 5 (TRAF5) protein has been molecularly cloned from a cDNA library of Human Daudi B cell line. The sequence analysis revealed that the cDNA encoded a protein of 557 aa residues with a calculated molecular weight of 64,236. The encoded protein has typical structural characteristics shown in the TRAF family of proteins and binds to the cytoplasmic region of lymphotoxin-beta receptor more efficiently than to that of CD40 and CD30. The TRAF5 gene was mapped to the human chromosome 1q32.3-q41.1. Overexpression of human TRAF5 activates NF kappa B transcription factor in human 293T kidney cells. These results suggest that the human TRAF5 protein could be involved in the signal triggered by various members of the tumor necrosis factor receptor (TNFR) superfamily including CD40, CD30 and lymphotoxin-beta receptor.

Developmental fate of single embryonic stem cells microinjected into 8-cell-stage mouse embryos

Embryonic stem (ES) cells are pluripotent and capable of differentiating into somatic as well as germ cell lineages when conjoined with blastomeres of early mouse embryos. However, the developmental potential of single ES cells has not been fully investigated. We injected single murine ES cells (A3-1 cell line) of 129 origin into 8-cell mouse embryos (B6xBDF1) and examined the patterns of distribution of ES-cell-derived cells in the blastocysts as well as in the fully grown chimeric mice. The ES cells underwent 1-2 cycles of mitosis between the 8-cell and the blastocyst stage when they were introduced as single cells, whereas those introduced as groups of 2-5 cells did not proliferate during the same period of development. The ES cells and their daughter cells were predominantly incorporated into the ICM. From the 63 8-cell embryos which received single ES cells microinjected into the perivitelline space, 24 newborns were obtained, and 4 (2 fertile males, 1 sterile female and 1 hermaphrodite) of them (16.6%) were chimeric. The test breeding studies revealed that all the progeny of the two chimeric males were derived from spermatozoa of 129 genotype. The relative contribution of the host-derived and the ES-cell-derived cells in different tissues of the chimeric mice was assessed by PCR analyses of the microsatellite polymorphism of genomic DNA extracted from the tissues. In two male germ line chimeras, the testes, the kidneys and the dorsal skeletal muscles exhibited exceptionally high 129 contents. Our results demonstrated that single ES cells which maintain totipotency or pluripotency of high degree are present in a colony of ES cells, and that single ES cells conjoined with the blastomeres of 8-cell-stage embryos may colonize, if the circumstances allow, almost exclusively the germ cells and concomitantly the urogenital cell lineages. Possible correlation between the allocation of the germ line and the urogenital lineages is discussed.

Highly sensitive mutation assay for mutagenicity monitoring of indoor air using Salmonella typhimurium YG1041 and a microsuspension method

A highly sensitive mutation assay for indoor mutagenicity monitoring was investigated by a combination of Salmonella typhimurium YG strains and the microsuspension method. Tester strains were YG1024, YG1029, YG1041 and YG1042. YG1041 gave the highest sensitivity in the mutagenicity test for the extracts of airborne particulates. The sensitivity of the microsuspension assay using S.typhimurium YG1041 in the absence of S9 mix was approximately 200 times higher than that of the preincubation assay using strain TA98, which has been widely used for mutagenicity monitoring of airborne particulates outdoors. Furthermore, a significant correlation was observed between mutagenicities determined by the microsuspension assay using S.typhimurium YG1041 and TA98, where mutagenicity assay was carried out for airborne particulates collected by a high volume sampler for 24 h every 12 days for 1 year. This new method was also useful for indoor mutagenicity monitoring in which a small amount of airborne particulates was collected by a low noise sampler for 12 h each of 6 consecutive days. The monitoring showed that mutagenicity in the daytime is generally higher than that in the night and that smoking is an important factor in increasing mutagenicity in indoor air.

Vitamin B12 enhances GABA content but reduces glutamate content in the rat suprachiasmatic nucleus

The present study attempted to elucidate effects of vitamin B12 (VB12) on the rat suprachiasmatic nucleus (SCN), which is the locus of the circadian clock in mammals, by evaluating the contents of its major neurotransmitters, gamma-aminobutyric acid (GABA) and glutamate (Glu). First, contents of these amino acids were analyzed from tissue samples prepared at three different circadian times (CTs) in free-running rats under constant dim illumination. The content of GABA was highest in the middle of the resting phase (CT 6), intermediate early in the active phase (CT 14), and lowest late in the active phase (CT 20), whereas Glu content indicated inverse circadian variations. Subsequently, effects of intracerebroventricularly infused VB12 were assayed at CT 20. Compared with the saline-infused control, the infusion of VB12 (30 nmol/30 microliters) at CT 12-15 significantly increased GABA content but decreased Glu content. The quantitative balance of these amino acids after VB12 infusion was similar to that at CT 6 in noninfused rats. These results suggest that infusion of VB12 to active rats shifts the ratio of SCN neurotransmitters toward that observed in resting rats.

A role for macrophage scavenger receptors in atherosclerosis and susceptibility to infection

Macrophage type-I and type-II class-A scavenger receptors (MSR-A) are implicated in the pathological deposition of cholesterol during atherogenesis as a result of receptor-mediated uptake of modified low-density lipoproteins (mLDL). MSR-A can bind an extraordinarily wide range of ligands, including bacterial pathogens, and also mediates cation-independent macrophage adhesion in vitro. Here we show that targeted disruption of the MSR-A gene in mice results in a reduction in the size of atherosclerotic lesions in an animal deficient in apolipoprotein E. Macrophages from MSR-A-deficient mice show a marked decrease in mLDL uptake in vitro, whereas mLDL clearance from plasma occurs at a normal rate, indicating that there may be alternative mechanisms for removing mLDL from the circulation. In addition, MSR-A-knockout mice show an increased susceptibility to infection with Listeria monocytogenes or herpes simplex virus type-1, indicating that MSR-A may play a part in host defence against pathogens.

Germ-line contribution of embryonic stem cells in chimeric mice: influence of karyotype and in vitro differentiation ability

The effect of the karyotype and the ability to differentiate in vitro upon germ-line transmission by A3-1 embryonic stem (ES) cells in chimeric mice were examined. Germ-line transmission was confirmed in ES cells exhibiting 38% and more of the normal karyotype, but no chimeric mice and/or germ-line transmitters were observed regardless of the karyotype when the cystic embryoid body (CEB) was formed on day 8 and later in the suspension culture. Germ-line transmission of the ES cells was not significantly influenced by formation of the simple embryoid body (SEB). Germ-line transmitters were preferentially observed in chimeras when the ES cell contribution to coat color was markedly increased, but this contribution to coat color varied regardless of the karyotype or in vitro differentiation ability. These results suggest that A3-1 ES cells which exhibit CEB at 7 days after suspension culture and approximately 40% of normal karyotype are capable of germ-line transmission in chimeric mice.

Identification of TRAF6, a novel tumor necrosis factor receptor-associated factor protein that mediates signaling from an amino-terminal domain of the CD40 cytoplasmic region

CD40 signalings play crucial roles in B-cell function. To identify molecules which transduce CD40 signalings, we have utilized the yeast two-hybrid system to clone cDNAs encoding proteins that bind the cytoplasmic tail of CD40. A cDNA encoding a putative signal transducer, designated TRAF6, has been molecularly cloned. TRAF6 has a tumor necrosis factor receptor (TNFR)-associated factor (TRAF) domain in its carboxyl terminus and has a RING finger domain, a cluster of zinc fingers and a coiled-coil domain, which are also present in other TRAF family proteins. TRAF6 does not associate with the cytoplasmic tails of TNFR2, CD30, lymphotoxin-beta receptor, and LMP1 of Epstein-Barr virus. Deletion analysis showed that residues 246-269 of CD40 which are required for its association with TRAF2, TRAF3, and TRAF5 are dispensable for its interaction with TRAF6, whereas residues 230-245 were required. Overexpression of TRAF6 activates transcription factor NFkappaB, and its TRAF-C domain suppresses NFkappaB activation triggered by CD40 lacking residues 246-277. These results suggest that TRAF6 could mediate the CD40 signal that is transduced by the amino-terminal domain (230-245) of the CD40 cytoplasmic region and appears to be independent of other known TRAF family proteins.

Effects of phosphate on in vitro 2-cell block of AKR/N mouse embryos based on changes in cdc2 kinase activity and phosphorylation states

This study demonstrated the effects of phosphate on the 2-cell block of AKR/N mouse embryos at the molecular level and focused on changes in the kinase activity and the phosphorylation state of cdc2, which is shown to regulate the cell division cycle. Removal of phosphate from the culture medium dramatically increased developmental rates to the 4-cell (91.8%) and blastocyst (42.6%) stages compared with those of embryos cultured in 1.17 mM phosphate (3.3% and 0%, respectively). The rate of development to the 4-cell stage was significantly inhibited by 0.001 mM phosphate (p < 0.05), and no morula formation was observed at 1.0 mM. The patterns of cdc2 kinase activity during the first cell cycle in AKR/N embryos were similar to those of control MCH embryos, showing the highest activity at M phase and low activity during the interphase. The phosphorylated form of cdc2 increased during the interphase, indicating that the synthesis of cyclin B and accumulation of inactive pre-maturation-promoting factor (pre-MPF) as well as abrupt dephosphorylation of cdc2 at the first cleavage correlated with the activation of cdc2 kinase. When phosphate was absent, the activation pattern of cdc2 kinase during the second cell cycle in AKR/N embryos was similar to that in the first cell cycle. On the other hand, no dephosphorylation of cdc2 was observed and the kinase activity remained at a low level until 56 h after insemination in the presence of phosphate, although an increase in phosphorylated cdc2 was observed as in the phosphate-free group. Treatment of AKR/N embryos arrested at the 2-cell stage with okadaic acid resulted in the dephosphorylation and activation of cdc2, confirming the presence of a sufficient amount of pre-MPF. These results show that phosphate has a deteriorative effect on the in vitro development of AKR/N embryos and suggest that this effect was not on the synthesis of cyclin B but on the dephosphorylation of phosphorylated cdc2.

State-dependent changes of extracellular glutamate in the medial preoptic area in freely behaving rats

Microdialysis technique was applied to the medial preoptic area (mPOA) of the hypothalamus, a crucial site for the regulation of sleep, in order to analyze the interrelationship between the extracellular level of glutamate (Glu) and the vigilance states. Dialysates from the mPOA were sampled at 5-min intervals for 2-h diurnal period with a perfusion rate of 2.0 microliters/min in freely moving rats, whose sleep-waking behaviors were polysomnographically monitored. Extracellular Glu increased during wakefulness, exhibiting a peak at the transition period from wakefulness to non-rapid-eye-movement sleep (NREMS) (18.0% above the average), whereas it decreased during NREMS (9.2% below the average). It is likely that Glu in the mPOA is dynamically involved in the alterations of the vigilance states.

Maintenance of pluripotency in mouse embryonic stem cells persistently infected with murine coronavirus

A persistently coronavirus-infected embryonic stem (ES) cell line A3/MHV was established by infecting an ES cell line, A3-1, with mouse hepatitis virus type-2. Although almost all A3/MHV cells were found infected, both A3/MHV and A3-1 cells expressed comparable levels of cell surface differentiation markers. In addition, A3/MHV cells retained the ability to form embryoid bodies. These results suggest that persistent coronavirus infection does not affect the differentiation of ES cells.

Gene transfer and expression in mouse preimplantation embryos by recombinant adenovirus vector

Replication-defective recombinant adenovirus, Adex4SRLacZL, was used as a vector for transferring exogenous genes in mouse zona pellucida-free eggs at the pronuclear stage. The vector contained the E. coli LacZ reporter gene under the control of the SR alpha promoter (SV40 early promoter-fused HTLV-I LTR), and the expression of the reporter gene was examined during preimplantation development in culture. Histochemical staining of the embryos for beta-galactosidase activity showed that the exogenous LacZ gene as expressed in 98% of the embryos at the morula-blastocyst stages. As in the microinjection method, the exogenous genes could be pursued from the 2-cell stage. Neither apparent morphological changes nor cytotoxic effects were observed. Both the percentages of embryos expressing reporter genes and the rate of development to the blastocyst stage were higher in the adenovirus vector-treated embryos than in the microinjected ones. These results suggest that the adenovirus vector system is a useful tool in investigating the genetic control of early mammalian development.

Mice deficient for the IL-3/GM-CSF/IL-5 beta c receptor exhibit lung pathology and impaired immune response, while beta IL3 receptor-deficient mice are normal

The receptors for IL-3, GM-CSF, and IL-5 share a common beta subunit (beta c), and mice have an additional IL-3 beta subunit (beta IL3). We have independently generated mice carrying null mutations of each molecule. beta c mutant bone marrow showed no response to GM-CSF or IL-5, whereas IL-3 stimulation of beta c or beta IL3 mutant bone marrow was normal. beta c mutant mice showed lung pathology consisting of lymphocytic infiltration and areas resembling alveolar proteinosis, and also exhibited low basal numbers of eosinophils. Infection of beta c mutant mice by Nippostrongylus brasiliensis resulted in the absence of blood and lung eosinophilia. Animals repopulated with beta c mutant bone marrow cells showed slower leukocyte recovery and reduced eosinophil numbers. These data define the role of beta c in vivo, and show a phenotype that is likely to be the cumulative effect of loss of GM-CSF and IL-5 stimulation.

Sperm from mice carrying a targeted mutation of the acrosin gene can penetrate the oocyte zona pellucida and effect fertilization

The physiological function of mammalian sperm acrosin has long been believed to be involved in the limited proteolysis of the oocyte zona pellucida, thus enabling the sperm to penetrate this extracellular matrix and to gain access to the oocyte plasma membrane. Here we show that male mice homozygous for a targeted mutation in the mouse acrosin gene are still fertile in spite of the complete absence of acrosin protease activity in the sperm. In vitro fertilization assays verified that sperm from the homozygous mutant mice penetrate the zona pellucida and effect fertilization. Therefore, acrosin is not essential for both sperm penetration of the zona pellucida and fertilization.

[Immunological effects of locoregional immunochemotherapy for liver metastases of gastric cancer]

Nine gastric cancer patients with simultaneous liver metastases were given intermittent transarterial administration of chemotherapeutics (adriamycin, mitomycin C or 5-fluorouracil) and biological response modifiers (BRM; OK-432 and interleukin (IL) -2) after gastrectomy. In terms of direct antitumor effect on liver metastases, a partial response was observed in 4 of 9 cases (44%). In addition, the concentration of 3 kinds of cytokines such as IL-6, tumor necrosis factor (TNF) -alpha and interferon (IFN) -gamma in the peripheral blood sera was measured immediately before and after transarterial administration of agents. While the concentration of IL-6 increased by BRM, chemotherapeutics could not alter the level of IL-6. As for TNF-alpha and IFN-gamma, no particular changing pattern was observed after transarterial administration. Furthermore, natural killer (NK) activity of peripheral blood mononuclear cells was measured. Administration of either BRM or BRM in combination with chemotherapeutics caused a decrease in NK activity, whereas chemotherapeutics did not. Flow cytometric analysis using 3 kinds of monoclonal antibodies (Anti-CD16, CD56 and CD57) revealed that the proportion of subset of both highly activated NK cells (CD16+.CD56+.CD57-) and moderately activated NK cells (CD16+.CD56+.CD57+) reduced after administration of BRM.

PCR sexing and developmental rate differences in preimplantation mouse embryos fertilized and cultured in vitro

A two-step polymerase chain reaction (PCR) assay was used to determine the sex of mouse preimplantation embryos obtained from oocytes fertilized and cultured in vitro, to investigate the differences in the developmental rates of mouse embryos according to the sex. All the in vitro developed embryos could be analyzed by this method. When the embryos were classified according to the time of morula to blastocyst transition as fast-intermediate- and slow-growing embryos, a significantly high percentage (78.0%) of the fast-developing embryos were identified as males; while a significantly lower percentage (42.5%) of slow-developing embryos were identified as males. The intermediate-developing embryos presented a sex ratio not significantly different from the total (57.5%). The deviation of sex ratio was further confirmed by embryo transfer experiment, where fast- and slow-developing embryos gave 76.2% and 25.7% male fetuses, respectively. We concluded that male mouse embryos fertilized and cultured in vitro develop faster than female embryos.