Evaluation of cortical bone density using clinical computed tomography images: Detection of cortical porosity areas or transitional zones in human femoral diaphyses

Age-related changes in human trabecular bone and cortical bone are known to vary. Although the porosity of cortical bone has been suggested to increase the risk of bone fracture, most of the currently available instruments for osteoporosis testing target trabecular bone. In this study, we evaluated cortical bone density using clinical computed tomography (CT) and compared the reliability of the cortical bone density index (CDI) with that of a polished male femoral bone from the same region. CDI images revealed that the porous area of cortical bone was extended in low CDI values. Moreover, this method was used to semi-quantitatively evaluate the cortical bones of the diaphysis of male femur specimens (n = 46). We found that there was a significant relationship (r = 0.70, p < 0.01) between the value of the cortical index (the ratio of cortical bone area to the cross-sectional area of the femoral diaphysis) and the average of CDI in the low signal area. Our findings suggest that the smaller the cortical bone occupancy, the more areas of consequential bone density loss were present. This may be the first step toward using clinical CT to assess cortical bone density.

Cross-sectional geometry of the femoral diaphyseal cortical bones: analysis of central mass distribution

A detailed analysis of differences in skeletal shape among many individuals is expected to reveal the mechanical significance behind various morphological features. To confirm the distribution of the cortical bone region in cross sections, the relative position of the central mass distribution (CMD) of the cortical bone region to the CMD of the entire cross section was examined. A total of 90 right human femoral skeletons were examined using clinical multi-slice computed tomography. For nine cross sections of each femur, we determined the CMD of the whole area, including both cortical bone and medullary areas, as CMD-W, and that of the cortical bone region in the same cross section as CMD-C, and they were compared. The medial and anterior portion of the cortex was relatively thick just below the lesser trochanter. The posterior cortical bone tended to be relatively thick in the region from the center to the distal part of the diaphysis. Females had a significantly more medially deviated CMD than males throughout the entire diaphysis. These results suggest that femurs with advanced cortical bone thinning tend to have a concentration of cortical bone in their medial portion. CMD-C was located farther from the diaphysis axis as the degree of medial bending increased. Conversely, the greater the lateral bending of the diaphysis, the closer CMD-C was to the diaphysis axis. As the amount of bone decreases with age, self-adjustment could occur so that the cortical bone's critical area remains to prevent a decrease in mechanical strength.

Characterization of lipidic plaque materials at calcified atheroma: its association with calcification thickness evaluated by optical coherence tomography and near-infrared spectroscopy imaging

Introduction

The degree of calcification and its thickness have been considered to affect stent expansion, leading to an increases risk of repeat revascularization in patients receiving PCI. Pathophysiologically, accumulation of lipidic materials within vessel wall could trigger the formation of plaque calcification. Elucidating characteristics of lipidic plaque components at calcified atheroma may enable to identify phenotypes with thick calcification which less likely responds to PCI.

Purpose

This study investigated the relationship of calcification thickness with lipidic plaque materials at calcified atheroma by using OCT and near-infrared spectroscopy (NIRS) imaging.

Methods

We analyzed 52 calcified lesions (culprit/non culprit lesions=44/8) in 47 CAD patients (stable CAD/ACS=36/11) from the REASSURE-NIRS registry (NCT04864171). OCT and NIRS imaging evaluated 4-mm segment exhibiting maximum superficial calcification arc. Calcification thickness on OCT imaging, its arc on IVUS imaging, and NIRS-derived lipid arc were analyzed at every 1-mm interval cross-sectional images. In addition, yellow-calcification ratio (YCR = lipid arc/calcification arc) was calculated (Figure 1).

Results

53% of study subjects exhibited chronic kidney disease and 70% of them received a statin (averaged on-treatment LDL-C =89mg/dL). Throughout OCT and NIRS/IVUS imaging analysis of 260 cross-sectional images, the averaged calcification arc, its maximum thickness, lipid arc and YCR were 210° (167–285°), 0.78mm (0.62–0.95mm), 95° (31–169°) and 0.33 (0.09–0.59), respectively. As expected, thicker calcification more likely exhibited a greater calcification arc (r=0.30, p&lt;0.001). Furthermore, a greater thickness of calcification was associated with smaller lipidic plaque burden, reflected by yellow arc (r=−0.36, p&lt;0.001) and YCR (r=−0.36, p&lt;0.001) (Figure 2). After adjusting age, gender and ACS, calcification arc (p&lt;0.001) and YCR (p&lt;0.001) continued to predict thicker calcification.

Conclusion

Thickening of calcification was associated with severer calcification arc, which was accompanied by the shrinkage of lipidic plaques. Our findings suggest the evaluation of lipidic plaque component as a potential tool to identify calcified atheroma harbouring thick calcification, which may cause a greater risk of stent underexpansion.

Funding Acknowledgement

Type of funding sources: None.

Randomized, double-blind, crossover, placebo-controlled clinical trial to evaluate the effects of chicken hot water extract on insulin secretion

OBJECTIVE

Essence of chicken (EOC), a hot water extract of chicken, is widely consumed in Southeast Asia as a beverage. EOC has an inhibitory effect on the elevation of blood glucose levels and a secretagogue effect on insulin. However, the mechanism by which EOC promotes insulin secretion is unknown. We aimed to verify the postprandial hyperglycemic inhibitory effect and the insulin secretory effect of EOC in healthy adults under appropriate placebo settings. In addition, we aimed to understand the mechanism underlying the insulin secretory effect of EOC.

PATIENTS AND METHODS

Thirty-four healthy Japanese adults were fed 68 mL of EOC or control food, followed by 200 g of cooked rice. Blood glucose and plasma insulin levels were measured at 30, 45, 60, 90, and 120 min after the participants ate cooked rice. The trial had a randomized, double-blind, crossover, placebo-controlled design.

RESULTS

The ingestion of EOC induced an increase in the maximum blood concentration (Cmax) of insulin and shortened the time required to reach the maximum blood concentration following rice consumption. Ingestion of the test beverage resulted in a significantly higher insulinogenic index than that obtained after ingestion of the control beverage. No side effects were observed in this study. Mechanistic experiments revealed that EOC stimulated significant (p < 0.05) secretion of GLP-1 from NCI-H716 human intestinal L cells at 0.1, 1, and 10 mg/mL.

CONCLUSIONS

Consuming EOC when eating rice supports pancreatic function. Daily consumption of EOC could elevate the early-phase insulin response; therefore, it could prevent diabetes in Asians with low insulin secretion.

The relationship of the underlying lipidic plaque at the implanted newer-generation drug-eluting stents with future stent-related events: insights from the REASSURE-NIRS registry

Background

Lipid-rich plaque is an important substrate causing acute coronary events. Near-infrared spectroscopy (NIRS) imaging has been shown to visualize lipidic coronary plaque at non-culprit site associated with future coronary events. Given that histopathological studies reported that the unstable plaque underlying the implanted drug-eluting stent (DES) could cause neoatherosclerosis formation, we hypothesized that NIRS-based evaluation of lipidic plaque burden behind the implanted DES may clinically predict the occurrence of stent failure in patients with CAD receiving PCI.

Purpose

We aimed to investigate the relationship of stent-related events' risk with lipidic plaque materials behind the implanted DES imaged by NIRS/intravascular ultrasound (NIRS/IVUS) imaging.

Methods

The REASSURE-NIRS registry is an on-going multi-center registry to enroll CAD subjects receiving NIRS/IVUS-guided PCI. In this registry data, 406 lesions in 379 CAD subjects (ACS/non-ACS=150/229) receiving new-generation DES were analyzed. Minimum stent area (MSA) after PCI and maximum lipid-core-burden index in any 4mm-segment within the implanted stents (in-stent maxLCBI4mm) were measured. A 3-year lesion-oriented composite outcome [LOCO: culprit lesion-related MI + ischemia-driven target lesion revascularization (ID-TLR)] was compared in subjects stratified according to the tertile of in-stent maxLCBI4mm.

Results

The mean value of in-stent maxLCBI4mm was 221, and 17% of lesions exhibited in-stent maxLCBI4mm &gt;400. Patients with a greater in-stent maxLCBI4mm were more likely to exhibit a higher LDL-C level (p=0.026) with a longer stent length (p&lt;0.001) and a smaller MSA (p=0.033) (Picture 1). Over 95% of entire study subjects received a statin. During the observational period (median=726 days), the frequency of LOCO up to 3 years was 3.4% in entire study subjects (culprit lesion-related MI=1.0%, ID-TLR=2.8%). Kaplan-Meier curve analysis demonstrated that the occurrence of LOCO did not increase in association with in-stent maxLCBI4mm (log-rank p-value=0.25, Picture 2). In addition, in-stent maxLCBI4mm did not associate with each component of LOCO (culprit lesion-related MI: p=0.502, ID-TLR: p=0.872). Receiver Operating Characteristic analysis revealed that the predictive ability of in-stent maxLCBI4mm for the occurrence of LOCO was unsatisfactorily (c-statistics=0.486).

Conclusion

The amount of underlying lipidic materials at culprit lesions receiving new-generation DES implantation did not necessarily predict future stent-related events. Clinical significance of maxLCBI4mm behind the implanted DES may be different from that at naïve non-culprit plaques.

Funding Acknowledgement

Type of funding sources: None. Background and lesion characteristicsKaplan-Meier analysis for LOCO

Comparison of coronary atherosclerotic features in response to achieving LDL-C &lt;55 mg/dl between non-diabetic and diabetic patients: insights from the REASSURE-NIRS registry

Introduction

Current ESC guideline recommends achieving LDL-C &lt;1.4 mmol/l in very high-risk subjects. Despite fabvourable anti-atherosclerotic effects of lowering LDL-C, its efficacy is diminished in type 2 diabetic patients. Whether response of coronary atheroma to on-treatment LDL-C &lt;1.4 mmol/l differs in diabetic and non-diabetic subjects has not been elucidated yet.

Methods

The REASSURE-NIRS registry is an on-going multi-center registry to enroll CAD subjects receiving PCI under the guidance of near-infrared spectroscopy/intravascular ultrasound (NIRS/IVUS: DualProTM, Nipro, Tokyo, Japan) imaging. Culprit lesions in 557 CAD patients who already received a statin were evaluated by NIRS/IVUS. Maximum 4-mm-lipid-core burden-index (maxLCBI4mm) and plaque calcification grade at culprit sites were measured. Calcification grade at each 1-mm cross-sectional image was defined as follows: calcium arc 0° = 0, 0–90° = 1, 90–180° = 2, 180–270° = 3, 270–360° = 4. MaxLCBI4mm and the averaged calcification grade were compared in diabetic and non-diabetic subjects stratified according to on-treatment LDL-C level, respectively.

Result

The proportion of diabetic (n=293, HbA1c; 6.9±0.9%) and non-diabetic patients (n=264) with on-treatment LDL-C &lt;1.4 mmol/l was 8.54 and 16.67%, respectivey (p=0.01). In non-diabetic patients, achieving LDL-C &lt;1.4mmol/L was associated with a lower maxLCBI4mm, whereas, in diabetic patients, maxLCBI4mm was numerically smaller under achieving LDL-C &lt;1.4 mmol/l, but this comparison did not meet statistical significance (Figure 1). Furthermore, a greater degree of calcification grade in non-diabetic patients was observed in association with on-treatment LDL-C level (Figure 2). However, plaque calcification at diabetic coronary atheroma was not necessarily induced under achieving stricter LDL-C goal. Subgroup analysis demonstrated that diabetic patients with body mass index ≥25 (odds ratio = 0.15; 95% CI: 0.18–1.19, p=0.04), estimated glomerular filtration rate &lt;60 (mL/min/1.73m2) (odds ratio = 0.31; 95% CI: 0.10–0.90, p=0.03) and non-insulin use (odds ratio = 0.36; 95% CI: 0.14–0.87, p=0.02) benefit from achieving LDL-C &lt;1.4 mmol/l.

Conclusion

Achieving LDL-C &lt;1.4 mmol/l was associated with more stabilized atheroma in non-diabetic patients with CAD, whereas these favourable effects were not observed in diabetic subjects. Our findings suggest the potential need to modify additional atherogenic risks for stabilizing diabetic coronary atheroma under achieving LDL-C &lt;1.4 mmol/l.

Funding Acknowledgement

Type of funding sources: None. Figure 1Figure 2

Morphological divergence in the curvature of human femoral diaphyses: Tracing the central mass distributions of cross-sections

The diaphysis of the human femoral bone has a physiological anterior curvature; additionally, there is a curvature to the medial side or lateral side. In addition to compression stress from gravity during standing, walking, and running, these bones are continuously exposed to complex stresses from the traction forces of the various strong muscles attached to them. The femoral diaphysis is subjected to these mechanical stresses, and the direction and size of its curvature are defined according to Wolff's law and the mechanostat theory of Frost. The purpose of this study was to quantitatively evaluate the curvature of the femoral diaphysis in Japanese skeletons by determining the curve connecting the central mass distributions (CMD) of cross-sectional images. A total of 90 right femora (46 males and 44 females) were randomly selected from modern Japanese skeletal specimens. Full-length images of these bones were acquired using a clinical computed tomography scanner. The range between the lower end of the lesser trochanter and the adductor tubercle of each femur was divided at regular intervals to obtain ten planes, and nine levels were analyzed. The CMD curve was determined by connecting the CMDs of each of the nine cross-sections. First, the CMD of a cross-section in each of the nine slices was calculated, and the nine trajectories were superimposed from above. Then, by converting the shape of the entire CMD curve to superimpose the coordinates of the endpoint on the starting point, a closed arc representing the curvature of the femur was determined. For both males and females, the patterns varied from mostly medial to largely lateral curvature. The size of the curvature also varied for individuals. By analyzing only the coordinates of the vertex of the CMD curve of each femoral bone, the outlines of the diaphyseal curvatures could be recognized. The femora were thereby divided into two groups: medial bending and lateral bending. Considering males and females together, the number in the lateral-curvature group (n = 51) was larger than that in the medial-curvature group (n = 39). Moreover, the average age of the lateral-curvature group was significantly higher than that of the medial-curvature group (p < 0.05). In males, with an increase in the cortical bone proportion of the cross-sectional area, the anterior vertex of diaphyseal bending tended to be more prominent. This cortical proportion was significantly higher in the medial-curvature groups than in the lateral-curvature group (p < 0.01). The phenomena observed in this study may be related to pathophysiologies such as atypical fractures of the femur and osteoarthritis of the knee joints.

Reduced cortical bone thickness increases stress and strain in the female femoral diaphysis analyzed by a CT-based finite element method: Implications for the anatomical background of fatigue fracture of the femur

The incidence of hip fractures is increasing in Japan and is high among women older than 70 years. While osteoporosis has been identified as one of the causative factors of fracture, atypical femoral fracture has emerged as a potential complication of bisphosphonate therapy. Atypical femoral fracture is prevalent among Asian women and has been attributed to morphological parameters. Age-related decreases in the morphological parameters of the femoral diaphysis, such as cortical bone thickness, cortical cross-sectional area, and the cortical index, were reported in Japanese women prior to bisphosphonate drugs being approved for treatment. Thus, in the present study, the relationships between biomechanical and morphological parameters were analyzed using a CT-based finite element method.

Finite element models were constructed from 44 femurs of Japanese women aged 31–87 years using CT data. Loading conditions were set as the single-leg configuration and biomechanical parameters, maximum and minimum principal stresses, Drucker-Prager equivalent stress, maximum and minimum strains, and strain energy density were calculated in 7 zones from the subtrochanteric region to distal diaphysis. Pearson's correlation coefficient test was performed to investigate relationships with morphological parameters.

While absolute stresses gradually decreased from the subtrochanteric region to distal diaphysis, absolute strains markedly declined in the proximal diaphysis and were maintained at the same levels as those in the distal regions. All types of stresses and minimum principal strain in the femoral diaphysis scored higher absolute values in the high-risk group (≥70 years, n = 28) than in the low-risk group (<70 years, n = 16) (p < 0.05). The distribution patterns of equivalent stress and strain energy density were similar to that of Young's modulus, except for the region of the linea aspera. All biomechanical parameters correlated with morphological parameters and correlation efficiencies, with the reciprocal of cortical bone thickness showing the strongest correlation.

The present results demonstrated that biomechanical parameters may be predicted by calculating the cortical bone thickness of femurs not treated with bisphosphonates. Furthermore, strain appeared to be repressed at a low level despite differences in stress intensities among the regions by bone remodeling. This remodeling is considered to be regulated by Wolff's law driven by equivalent stress and strain energy densities from the proximal to distal femur. The present results will promote further investigations on the contribution of morphological parameters in the femoral diaphysis to the onset of atypical femoral fracture.

•

Stresses in the femoral diaphysis were higher in the high-risk group (≥70 years).

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The distributions of equivalent stress were similar to that of Young's modulus.

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All biomechanical parameters strongly correlated with the cortical bone thickness.

Gross anatomical investigation of the muscular head between the vastus lateralis and intermedius in the Japanese population: a cadaver study

Unlike the general understanding of the quadriceps femoris, the existence of a new muscular head between the vastus lateralis and the vastus intermedius was reported, and named the tensor of the vastus intermedius in the Swedish population. The purpose of this study was to investigate the presence and form of the muscular head in the Japanese population and to clarify its structure by gross anatomical approaches. A total of 35 thighs of 20 Japanese cadavers were investigated. We searched for the muscular head and classified it into four types. In addition, nerve fiber analysis was performed for each classification type. Regarding classification, 11% were the independent type, 29% were the common type, 37% were the vastus lateralis type, and 23% were the vastus intermedius type. Based on nerve fiber analysis, in the common type, the muscular head was under dual nerve supply from the vastus lateralis and intermedius. The other three types were innervated only by nerves from the vastus lateralis. The target muscular head may always be present in Japanese. The nerves from the vastus lateralis were always distributed in the target muscular head based on nerve fiber analysis; therefore, this muscular head may be most closely related to the vastus lateralis. The name of this muscular head should be "the accessory head of the vastus lateralis" rather than "the tensor of the vastus intermedius."

Characterization of plaque features exhibiting physiological mismatch between fractional flow reserve and resting index: near-infrared spectroscopy imaging analysis

Background

In addition to fractional flow reserve (FFR), resting indexes (RI) have been shown as another physiological measure to evaluate myocardial ischemia. Despite the clinical usefulness of RI without the use of intravenous vasodilatory agent, discrepancy between FFR and RI infrequently occurs. Whether this physiological mismatch is derived by specific plaque feature remains unknown.

Purpose

To characterize coronary plaques associated with coronary physiological mismatch.

Methods

We analyzed 59 coronary arteries (LAD/RCA/LCX=49/4/6) with FFR≤0.80 in 57 stable CAD subjects receiving PCI. Following measurement of FFR and RI, culprit lesion was evaluated by near-infrared spectroscopy and intravascular ultrasound (NIRS/IVUS). The analyzed vessels were stratified according to FFR and RI values: FFR≤0.75+RI&gt;0.89 (n=6: physiological mismatch), FFR&gt;0.75+RI&gt;0.89 (n=6), FFR≤0.75+RI≤0.89 (n=33) and FFR&gt;0.75+RI≤0.89 (n=14).

Results

The median values of percent diameter stenosis, FFR and RI were 51%, 0.75 and 0.87, respectively. Physiological mismatch was observed in 10.1% (=6/59) of analyzed vessels. On IVUS imaging, maximum percent plaque area was greater than 70% in all groups (p=0.29). Furthermore, there were no significant differences in angiographic and IVUS-derived minimum lumen area across 4 groups (Table). However, culprit lesions exhibiting physiological mismatch contained a substantially larger amount of lipid plaque, reflected by a higher maximum 4-mm lipid-core burned index (maxLCBI4mm: p=0.04) on NIRS imaging (Table). Multivariate analysis demonstrated maxLCBI4mm as the only plaque feature associated with physiological mismatch (odds ratio=1.010, 95% CI: 1.001–1.019, p=0.02).

Conclusion

Plaque feature associated with coronary physiological mismatch was the extent of lipidic materials but not the quantity of coronary atheroma. Since the accumulation of lipidic plaque component is caused by endothelial dysfunction, this vascular substrate could impair baseline vasomotion, thereby causing a lower FFR despite preserved RI value. Evaluation of lipidic burden may be a potential option to avoid unnecessary deferral of revascularization in subjects with normal RI value.

maxLCBI4mm in each group

Funding Acknowledgement

Type of funding source: None

Spindle Orientation-Independent Control of Cell Fate Determination by RGS3 and KIF20A

It was proposed that similar to its role in the invertebrate nervous system, mitotic spindle orientation (or cell cleavage plane orientation) of a dividing neural progenitor cell specifies the fate of daughter cells in the mammalian brain, modulating the production of neurons via symmetric versus asymmetric cell divisions during the course of neurogenesis. Experimental tests of the sufficiency of spindle/cleavage plane orientation in mammalian cell fate determination have yielded conflicting results. On the other hand, the necessity of spindle/cleavage plane orientation in mammalian cell fate determination has not yet been addressed. Here we examined the necessity of spindle/cleavage plane orientation during cortical neurogenesis in mice with loss-of-function of the RGS3-KIF20A interaction axis. We present evidence that while inactivation of RGS3 or KIF20A was linked to a shift in neural progenitor cells from proliferative to differentiative divisions in the developing cortex, these genetic mutations did not lead to anticipated alteration in the orientation of spindle/cleavage plane. Our results indicate that the RGS3-KIF20A axis regulates the balance between proliferation and differentiation in the mammalian cortex employing a mechanism independent of spindle/cleavage plane orientation. These data also caution against using spindle/cleavage plane orientation as the synonym for cell fate determination.

P5635Predictive ability of lipdic burden for FFR-derived physiological measures: insights from near-infrared spectroscopy imaging analysis

Background

Fractional flow reserve (FFR) has enabled to physiologically assess the myocardial ischemia of coronary artery with intermediate stenosis. Mechanistically, not only the severity of coronary stenosis but also the extent of maximal vasodilatation within the entire coronary artery potentially affects this physiological measure. Since the accumulation of lipidic materials within vessel wall increases vascular stiffness via inducing endothelial dysfunction, the presence of lipidic atheroma burden may affect physiological measures.

Purpose

To investigate the association of FFR with lipidic coronary atheroma by near-infrared spectroscopy/intravascular ultrasound (NIRS/IVUS) imaging, which quantitatively visualize lipidic burden in vivo.

Methods

We analyzed 61 coronary arteries (LAD/RCA/LCX=52/5/4) with FFR≤0.80 in 59 stable coronary artery disease subjects receiving PCI. Following FFR measurement, NIRS/IVUS imaging was conducted to evaluate the extent of atheroma burden (maximum percent plaque area=max%PA) and lipidic materials (lipid core burden index within the entire vessel=LCBIvessel). The analyzed vessels were stratified according to FFR: definite FFR group (FFR≤0.74, n=34) and gray-zone FFR group (0.75≤FFR≤0.80, n=27).

Results

NIRS/IVUS imaging analysis (analyzed longitudinal length=77±7mm) was more likely to exhibit a significantly higher LCBIvessel and a larger max%PA in the definite FFR group (Table). Of note, FFR was significantly correlated to LCBIvessel (ρ=-0.299, p=0.02), but not max%PA (ρ=-0.255, p=0.07). Multivariate analysis demonstrated that an independent determinant of FFR≤0.74 was LCBIvessel [odds ratio (OR)=1.016, 95% confidential interval (CI)=1.002–1.031, p=0.02], but not max%PA [OR=1.084, 95% CI=0.994–1.182, p=0.07]. Area under the receiver-operating characteristic curve analysis elucidated that the addition of LCBIvessel to angiography- and IVUS-derived measures resulted in a significant improvement for detecting FFR≤0.74 (picture).

Definite FFR Group (FFR≤0.74, n=34) Gray-zone FFR Group (0.75≤FFR≤0.80, n=27) p value Fractional flow reserve (FFR) 0.68±0.05 0.78±0.02 <0.01 Percent diameter stenosis (%) 56.2±13.1 51.9±7.8 0.16 Maximum percent plaque area (max%PA, %) 84.3±6.9 79.9±7.2 0.01 Lipid core burden index within the entire vessel (LCBIvessel) 102.0±60.2 65.6±51.6 0.01

ROC analysis for detecting FFR≦0.74

Conclusion

The propagation of lipidic burden associates with the physiological measures. The present findings indicate the possibility that vessel characteristics or instability may have influence for causing ischemia on the coronary artery.

KIF20A/MKLP2 regulates the division modes of neural progenitor cells during cortical development

Balanced symmetric and asymmetric divisions of neural progenitor cells (NPCs) are crucial for brain development, but the underlying mechanisms are not fully understood. Here we report that mitotic kinesin KIF20A/MKLP2 interacts with RGS3 and plays a crucial role in controlling the division modes of NPCs during cortical neurogenesis. Knockdown of KIF20A in NPCs causes dislocation of RGS3 from the intercellular bridge (ICB), impairs the function of Ephrin-B-RGS cell fate signaling complex, and leads to a transition from proliferative to differentiative divisions. Germline and inducible knockout of KIF20A causes a loss of progenitor cells and neurons and results in thinner cortex and ventriculomegaly. Interestingly, loss of function of KIF20A induces early cell cycle exit and precocious neuronal differentiation without causing substantial cytokinesis defect or apoptosis. Our results identify a RGS-KIF20A axis in the regulation of cell division and suggest a potential link of the ICB to regulation of cell fate determination.

Functional Characterization of Ngf-Secreting Cell Grafts to the Acutely Injured Spinal Cord

Previously we reported that grafts of cells genetically modified to produce human nerve growth factor (hNGF) promoted specific and robust sprouting of spinal sensory, motor, and noradrenergic axons. In the present study we extend these investigations to assess NGF effects on corticospinal motor axons and on functional outcomes after spinal cord injury. Fibroblasts from adult rats were transduced to express human NGF; control cells were not genetically modified. Fibroblasts were then grafted to sites of midthoracic spinal cord dorsal hemisection lesions. Three months later, recipients of NGF-secreting grafts showed deficits on conditioned locomotion over a wire mesh that did not differ in extent from control-lesioned animals. On histological examination, NGF-secreting grafts elicited specific sprouting from spinal primary sensory afferent axons, local motor axons, and putative cerulospinal axons as previously reported, but no specific responses from corticospinal axons. Axons responding to NGF robustly penetrated the grafts but did not exit the grafts to extend to normal innervation territories distal to grafts. Grafted cells continued to express NGF protein through the experimental period of the study. These findings indicate that 1) spinal cord axons show directionally sensitive growth responses to neurotrophic factors, 2) growth of axons responding to a neurotrophic factor beyond an injury site and back to their natural target regions will likely require delivery of concentration gradients of neurotrophic factors toward the target, 3) corticospinal axons do not grow toward a cellular source of NGF, and 4) functional impairments are not improved by strictly local sprouting response of nonmotor systems.

Assessment of the efficacy of membrane filtration processes to remove human enteric viruses and the suitability of bacteriophages and a plant virus as surrogates for those viruses

Here, we evaluated the efficacy of direct microfiltration (MF) and ultrafiltration (UF) to remove three representative human enteric viruses (i.e., adenovirus [AdV] type 40, coxsackievirus [CV] B5, and hepatitis A virus [HAV] IB), and one surrogate of human caliciviruses (i.e., murine norovirus [MNV] type 1). Eight different MF membranes and three different UF membranes were used. We also examined the ability of coagulation pretreatment with high-basicity polyaluminum chloride (PACl) to enhance virus removal by MF. The removal ratios of two bacteriophages (MS2 and φX174) and a plant virus (pepper mild mottle virus; PMMoV) were compared with the removal ratios of the human enteric viruses to assess the suitability of these viruses to be used as surrogates for human enteric viruses. The virus removal ratios obtained with direct MF with membranes with nominal pore sizes of 0.1-0.22 μm differed, depending on the membrane used; adsorptive interactions, particularly hydrophobic interactions between virus particles and the membrane surface, were dominant factors for virus removal. In contrast, direct UF with membranes with nominal molecular weight cutoffs of 1-100 kDa effectively removed viruses through size exclusion, and >4-log₁₀ removal was achieved when a membrane with a nominal molecular weight cutoff of 1 kDa was used. At pH 7 and 8, in-line coagulation-MF with nonsulfated high-basicity PACls containing Al₃₀ species had generally a better virus removal (i.e., >4-log₁₀ virus removal) than the other aluminum-based coagulants, except for φX174. For all of the filtration processes, the removal ratios of AdV, CV, HAV, and MNV were comparable and strongly correlated with each other. The removal ratios of MS2 and PMMoV were comparable or smaller than those of the three human enteric viruses and MNV, and were strongly correlated with those of the three human enteric viruses and MNV. The removal ratios obtained with coagulation-MF for φX174 were markedly smaller than those obtained for the three human enteric viruses and MNV. However, because MS2 was inactivated after contact with PACl during coagulation pretreatment, unlike AdV, CV, MNV, and PMMoV, the removal ratios of infectious MS2 were probably an overestimation of the ability of coagulation-MF to remove infectious AdV, CV, and caliciviruses. Thus, PMMoV appears to be a suitable surrogate for human enteric viruses, whereas MS2 and φX174 do not, for the assessment of the efficacy of membrane filtration processes to remove viruses.

Elimination of representative contaminant candidate list viruses, coxsackievirus, echovirus, hepatitis A virus, and norovirus, from water by coagulation processes

We examined the removal of representative contaminant candidate list (CCL) viruses (coxsackievirus [CV] B5, echovirus type [EV] 11, and hepatitis A virus [HAV] IB), recombinant norovirus virus-like particles (rNV-VLPs), and murine norovirus (MNV) type 1 by coagulation. Water samples were subjected to coagulation with polyaluminum chloride (PACl, basicity 1.5) followed by either settling or settling and filtration. Together with our previously published results, the removal ratio order, as evaluated by a plaque-forming-unit method or an enzyme-linked immunosorbent assay after settling, was HAV>EV=rNV-VLPs≥CV=poliovirus type 1=MNV>adenovirus type 40 (range, 0.1-2.7-log₁₀). Infectious HAV was likely inactivated by the PACl and therefore was removed to a greater extent than the other viruses. A nonsulfated high-basicity PACl (basicity 2.1), removed the CCL viruses more efficiently than did two other sulfated PACls (basicity 1.5 or 2.1), alum, or ferric chloride. We also examined the removal ratio of two bacteriophages. The removal ratios for MS2 tended to be larger than those of the CCL viruses, whereas those for φX174 were comparable with or smaller than those of the CCL viruses. Therefore, φX174 may be a useful conservative surrogate for CCL viruses during coagulation.

Investigation of enteric adenovirus and poliovirus removal by coagulation processes and suitability of bacteriophages MS2 and φX174 as surrogates for those viruses

We evaluated the removal of enteric adenovirus (AdV) type 40 and poliovirus (PV) type 1 by coagulation, using water samples from 13 water sources for drinking water treatment plants in Japan. The behaviors of two widely accepted enteric virus surrogates, bacteriophages MS2 and φX174, were compared with the behaviors of AdV and PV. Coagulation with polyaluminum chloride (PACl, basicity 1.5) removed AdV and PV from virus-spiked source waters: the infectious AdV and PV removal ratios evaluated by means of a plaque-forming-unit method were 0.1-1.4-log10 and 0.5-2.4-log10, respectively. A nonsulfated high-basicity PACl (basicity 2.1) removed infectious AdV and PV more efficiently than did other commercially available PACls (basicity 1.5-2.1), alum, and ferric chloride. The MS2 removal ratios tended to be larger than those of AdV and PV, partly because of differences in the hydrophobicities of the virus particles and the sensitivity of the virus to the virucidal activity of PACl; the differences in removal ratios were not due to differences in the surface charges of the virus particles. MS2, which was more hydrophobic than the other viruses, was inactivated during coagulation with PACl. Therefore, MS2 does not appear to be an appropriate surrogate for AdV and PV during coagulation. In contrast, because φX174, like AdV and PV, was not inactivated during coagulation, and because the hydrophobicity of φX174 was similar to or somewhat lower than the hydrophobicities of AdV and PV, the φX174 removal ratios tended to be similar to or somewhat smaller than those of the enteric viruses. Therefore, φX174 is a potential conservative surrogate for AdV and PV during coagulation. In summary, the surface hydrophobicity of virus particles and the sensitivity of the virus to the virucidal activity of the coagulant are probably important determinants of the efficiency of virus removal during coagulation.

Prevention of steroid-induced osteonecrosis of femoral head in systemic lupus erythematosus by anti-coagulant

Although osteonecrosis of femoral head (ONF) is one of the serious complications in systemic lupus erythematosus (SLE) associated with corticosteroid therapy, there has been few trials of prevention of ONF described. We aimed to prevent ONF in steroid-treated SLE patients using anticoagulant, warfarin, conducting a multicenter prospective study. Sixty newly diagnosed SLE patients requiring 40 mg/day or more prednisolone were alternately assigned to either of two groups; a warfarin group and a control one. Warfarin (1 ∼ 5 mg/day) was started together with the beginning of steroid therapy and continued at least for three months. Patients were observed for the development of silent ONF by magnetic resonance imaging (MRI) and symptomatic ONF by plain radiography for over five years. The warfarin group consisted of 31 patients (62 hips) and the control one 29 patients (58 hips). Silent ONF developed in 13 hips (21%) and 19 hips (33%) in the warfarin group and the control group, respectively ( P = 0.13). On the other hand, warfarin tended to prevent symptomatic ONF; only three hips of 62 (4.8%) in the warfarin group and eight hips of 58 (14%) in the control group ( P = 0.08) developed silent ONF. It was also found that silent ONF developed, if it did, very early; within three months in 16 of 18 patients (89%). Among risk factors for silent ONF, steroid pulse therapy was most outstanding and it seemed to overcome the effect of warfarin. Taken together, for the time being, anticoagulant therapy, if not significantly sufficient, may be of use for the prevention of steroid-induced ONF in SLE. We consider that this study added to important evidence for the pathogenesis and prevention of ONF.

Very early development of steroid-associated osteonecrosis of femoral head in systemic lupus erythematosus: prospective study by MRI

The objective of this study was to define prospectively the early development of corticosteroid-induced osteonecrosis of femoral head (ONF) in patients with systemic lupus erythematosus (SLE) and to identify the association of initial steroid treatment with the development of early (silent) ONF. Forty-five patients who were newly diagnosed as having SLE and required 40 mg/day or more prednisolone were enrolled. To detect silent ONF, examinations using magnetic resonance imaging (MRI) were done three months after starting steroid therapy, followed by every year’s MRI and plain radiography for over five years. Clinical and laboratory data were compared between silent ONF and non-ONF groups. Of 45 patients, 15 (33%) developed silent ONF and five (11%) symptomatic ONF. It was of interest that MRI detected silent ONF very early (by three months) in 14 patients (93%). It should be noted that pulse therapy with 1000 mg/day methylprednisolone was found to be done very frequently (13 of 15, 87%) in the silent ONF group compared to non-ONF group (11 of 30, 37%) (P, 0.01) although other clinical features were not significantly different between both groups. High dose corticosteroids caused elevation of serum levels of total cholesterol, albumin, and leukocyte count in most of patients. The degree of elevation of those parameters at one or three months was more prominent in the silent ONF group. In particular, the change ratio of total cholesterol at one month was outstanding in the silent ONF group compared to non-ONF group (0.551 versus 0.374, P, 0.05). In conclusion, pathological ONF develops very early in one-third of SLE patients who received high dose corticosteroids and steroid pulse therapy could be a significant risk factor. An abrupt elevation of serum total cholesterol and/or sensitivity to steroids seem to be associated with the pathogenesis of ONF.

Downregulation of TLX induces TET3 expression and inhibits glioblastoma stem cell self-renewal and tumorigenesis

Glioblastomas have been proposed to be maintained by highly tumorigenic glioblastoma stem cells (GSCs) that are resistant to current therapy. Therefore, targeting GSCs is critical for developing effective therapies for glioblastoma. In this study, we identify the regulatory cascade of the nuclear receptor TLX and the DNA hydroxylase Ten eleven translocation 3 (TET3) as a target for human GSCs. We show that knockdown of TLX expression inhibits human GSC tumorigenicity in mice. Treatment of human GSC-grafted mice with viral vector-delivered TLX shRNA or nanovector-delivered TLX siRNA inhibits tumour development and prolongs survival. Moreover, we identify TET3 as a potent tumour suppressor downstream of TLX to regulate the growth and self-renewal in GSCs. This study identifies the TLX-TET3 axis as a potential therapeutic target for glioblastoma.

TLX is a nuclear receptor essential for neural stem cell self-renewal and recently involved in glioblastoma development. In this study, the authors show that inhibition of TLX expression, achieved using a dendrimer nanovector-delivered siRNAs or viral vector-delivered shRNAs, reduces glioblastoma stem cells self renewal and in vivo tumour growth through activation of TET3.

Third heart sound in hospitalised patients with acute heart failure: insights from the ATTEND study

BACKGROUND

Several previous studies have suggested that detection of a third heart sound (S3) in patients with chronic congestive heart failure is associated with adverse long-term outcomes. However, the short-term prognostic value of identifying an S3 on admission in patients with acute heart failure (AHF) is not well established. We therefore analysed the in-hospital prognostic value of detecting an S3 on admission in hospitalised patients with AHF.

METHODS

The Acute Decompensated Heart Failure Syndromes (ATTEND) study investigators enrolled 4107 patients hospitalised with AHF. Investigators evaluated the presence or absence of an S3 during routine physical examination.

RESULTS

On admission to hospital, 1673 patients (41%) had an S3. Patients with an S3 had a higher heart rate, higher serum level of B-type natriuretic peptide and higher creatinine levels than patients without an S3. However, there were no significant differences of systolic blood pressure, serum sodium, haemoglobin, C-reactive protein and total bilirubin between the two groups. Multivariate analysis adjusted for various markers of disease severity revealed that only the presence of an S3 was independently associated with an increase of in-hospital all cause death [adjusted odds ratio (OR), 1.69; 95% confidence interval (CI), 1.19-2.41; p = 0.003] and cardiac death (adjusted OR, 1.66; 95% CI, 1.08-2.54; p = 0.020) among the congestive physical findings related to heart failure (S3, rales, jugular venous distension and peripheral oedema).

CONCLUSIONS

Detecting an S3 on admission was independently associated with adverse in-hospital outcomes in patients with AHF. Our findings suggest that careful bedside assessment is clinically meaningful.

Successful treatment using high-dose intravenous immunoglobulin in a patient with rapidly progressive interstitial pneumonia associated with dermatomyositis

Abstract A 36-year-old male patient with dermatomyo-sitis (DM) associated with rapidly progressive interstitial pneumonia (IP) was successfully treated by high-dose intravenous immunoglobulin (IVIG). He suffered from myopathy, skin lesions, and IP. In spite of the treatment with a high-dose corticosteroid, IP progressed rapidly. Then high-dose intravenous immunoglobulin (20 g/day, 4 days) was administered. The skin lesions, myopathy, and pulmonary lesions improved. High-dose IVIG was considered to be a relatively safe and effective treatment for progressive IP associated with DM.

Tet1 regulates adult hippocampal neurogenesis and cognition

DNA hydroxylation catalyzed by Tet dioxygenases occurs abundantly in embryonic stem cells and neurons in mammals. However, its biological function in vivo is largely unknown. Here, we demonstrate that Tet1 plays an important role in regulating neural progenitor cell proliferation in adult mouse brain. Mice lacking Tet1 exhibit impaired hippocampal neurogenesis accompanied by poor learning and memory. In adult neural progenitor cells deficient in Tet1, a cohort of genes involved in progenitor proliferation were hypermethylated and downregulated. Our results indicate that Tet1 is positively involved in the epigenetic regulation of neural progenitor cell proliferation in the adult brain.

Characterization of TLX expression in neural stem cells and progenitor cells in adult brains

TLX has been shown to play an important role in regulating the self-renewal and proliferation of neural stem cells in adult brains. However, the cellular distribution of endogenous TLX protein in adult brains remains to be elucidated. In this study, we used immunostaining with a TLX-specific antibody to show that TLX is expressed in both neural stem cells and transit-amplifying neural progenitor cells in the subventricular zone (SVZ) of adult mouse brains. Then, using a double thymidine analog labeling approach, we showed that almost all of the self-renewing neural stem cells expressed TLX. Interestingly, most of the TLX-positive cells in the SVZ represented the thymidine analog-negative, relatively quiescent neural stem cell population. Using cell type markers and short-term BrdU labeling, we demonstrated that TLX was also expressed in the Mash1+ rapidly dividing type C cells. Furthermore, loss of TLX expression dramatically reduced BrdU label-retaining neural stem cells and the actively dividing neural progenitor cells in the SVZ, but substantially increased GFAP staining and extended GFAP processes. These results suggest that TLX is essential to maintain the self-renewing neural stem cells in the SVZ and that the GFAP+ cells in the SVZ lose neural stem cell property upon loss of TLX expression. Understanding the cellular distribution of TLX and its function in specific cell types may provide insights into the development of therapeutic tools for neurodegenerative diseases by targeting TLX in neural stem/progenitors cells.

Genome-wide profiling identified a set of miRNAs that are differentially expressed in glioblastoma stem cells and normal neural stem cells

A major challenge in cancer research field is to define molecular features that distinguish cancer stem cells from normal stem cells. In this study, we compared microRNA (miRNA) expression profiles in human glioblastoma stem cells and normal neural stem cells using combined microarray and deep sequencing analyses. These studies allowed us to identify a set of 10 miRNAs that are considerably up-regulated or down-regulated in glioblastoma stem cells. Among them, 5 miRNAs were further confirmed to have altered expression in three independent lines of glioblastoma stem cells by real-time RT-PCR analysis. Moreover, two of the miRNAs with increased expression in glioblastoma stem cells also exhibited elevated expression in glioblastoma patient tissues examined, while two miRNAs with decreased expression in glioblastoma stem cells displayed reduced expression in tumor tissues. Furthermore, we identified two oncogenes, NRAS and PIM3, as downstream targets of miR-124, one of the down-regulated miRNAs; and a tumor suppressor, CSMD1, as a downstream target of miR-10a and miR-10b, two of the up-regulated miRNAs. In summary, this study led to the identification of a set of miRNAs that are differentially expressed in glioblastoma stem cells and normal neural stem cells. Characterizing the role of these miRNAs in glioblastoma stem cells may lead to the development of miRNA-based therapies that specifically target tumor stem cells, but spare normal stem cells.

miR-137 forms a regulatory loop with nuclear receptor TLX and LSD1 in neural stem cells

miR-137 is a brain-enriched microRNA. Its role in neural development remains unknown. Here we show that miR-137 has an essential role in controlling embryonic neural stem cell fate determination. miR-137 negatively regulates cell proliferation and accelerates neural differentiation of embryonic neural stem cells. In addition, we show that the histone lysine-specific demethylase 1 (LSD1), a transcriptional co-repressor of nuclear receptor TLX, is a downstream target of miR-137. In utero electroporation of miR-137 in embryonic mouse brains led to premature differentiation and outward migration of the transfected cells. Introducing a LSD1 expression vector lacking the miR-137 recognition site rescued miR-137-induced precocious differentiation. Furthermore, we demonstrate that TLX, an essential regulator of neural stem cell self-renewal, represses the expression of miR-137 by recruiting LSD1 to the genomic regions of miR-137. Thus, miR-137 forms a feedback regulatory loop with TLX and LSD1 to control the dynamics between neural stem cell proliferation and differentiation during neural development.

Gα subunit coordinates with ephrin-B to balance self-renewal and differentiation in neural progenitor cells

Proper development of the mammalian brain requires that neural progenitor cells balance self-renewal and differentiation under precise temporal and spatial regulation, but the underlying mechanisms are not well understood. In this study, we identify Gα subunit as a positive regulator of mammalian neurogenesis, working with the regulator of G protein signaling (RGS)-mediated ephrin-B signaling pathway as two opposing forces to maintain a balance between self-renewal and differentiation in the developing mouse cerebral cortex. Multiple Gα(i) subunits are expressed by cortical neural progenitor cells during the course of cortical neurogenesis. Activation of Gα(i) signaling, through in utero electroporation-mediated expression of wild-type and constitutively active Gα(i) subunits, counteracts the function of ephrin-B in cortical neural progenitors to induce differentiation. Genetic knock-in of an RGS-insensitive G184SGα(i2) causes early cell cycle exit and a reduction of cortical neural progenitor cells and leads to a defect in the production of late born cortical neurons, similar to what is observed in mutant mice with deficiency in ephrin-B reverse signaling pathway. This study reveals a role of Gα subunit in mammalian neurogenesis and uncovers a developmental mechanism, coordinated by the Gα and ephrin-B signaling pathways, for control of the balance between self-renewal and differentiation in neural progenitor cells.

Smoking-related changes in the background lung of specimens resected for lung cancer: a semiquantitative study with correlation to postoperative course

AIMS

To assess the pathological findings in lobectomy specimens, to correlate them with smoking history and postoperative course and to compare the findings with those in smoking-related interstitial lung disease.

METHODS AND RESULTS

Patients who had undergone lobectomy for lung cancer were reviewed. Subjects included 230 non-smokers and 587 smokers, of whom 572 had a known smoking index (SI). They were classified into mild, moderate and heavy smokers. Centrilobular emphysema (CLE), respiratory bronchiolitis, airspace enlargement with fibrosis (AEF), the presence of foci resembling usual interstitial pneumonia pattern (UIP/P) and the rate of postoperative respiratory failure were assessed. The incidence of AEF was 6.5% in mild smokers, and 17.7% in moderate smokers (P < 0.01) with lower lobe predominance. There were significant correlations (P < 0.01) between AEF and CLE and AEF and UIP/P. The rate of respiratory failure after lobectomy was 6%, and 10% in patients having UIP/P with or without AEF, but was not seen in patients with AEF alone (P < 0.01).

CONCLUSIONS

AEF is an important smoking-related change in the lung that appears to correlate with the smoking history, and its distinction from UIP/P may be important.

Regulation of neural progenitor cell state by ephrin-B

Maintaining a balance between self-renewal and differentiation in neural progenitor cells during development is important to ensure that correct numbers of neural cells are generated. We report that the ephrin-B–PDZ-RGS3 signaling pathway functions to regulate this balance in the developing mammalian cerebral cortex. During cortical neurogenesis, expression of ephrin-B1 and PDZ-RGS3 is specifically seen in progenitor cells and is turned off at the onset of neuronal differentiation. Persistent expression of ephrin-B1 and PDZ-RGS3 prevents differentiation of neural progenitor cells. Blocking RGS-mediated ephrin-B1 signaling in progenitor cells through RNA interference or expression of dominant-negative mutants results in differentiation. Genetic knockout of ephrin-B1 causes early cell cycle exit and leads to a concomitant loss of neural progenitor cells. Our results indicate that ephrin-B function is critical for the maintenance of the neural progenitor cell state and that this role of ephrin-B is mediated by PDZ-RGS3, likely via interacting with the noncanonical G protein signaling pathway, which is essential in neural progenitor asymmetrical cell division.

Investigation of formaldehyde pollution of tap water and rain water using a novel visual colorimetry

The pollution of tap water and rain water with formaldehyde in Toyama Pref., Japan was investigated by means of a simple, rapid and cost-effective visual colorimetry developed by us. The levels of formaldehyde in three tap waters from different sources of dams on mountainside and a well-water pumped in urban area in Toyama Pref. were lower than 0.01 mg L(-1) that was the detection limit of the colorimetry. On the other hand, rain waters were seriously polluted with formaldehyde. Rain waters were sampled from three different sites (urban area, top of hill and industrial area) in Toyama Pref. from autumn to winter in 2006. The levels of formaldehyde in the rain waters ranged from 0.07 to 0.30 mg L(-1). The analytical results by the visual colorimetry were in good agreement with those obtained by GC-MS method. It was confirmed that the colorimetry is excellent for practical use for the determination of formaldehyde. It must be concerned about the pollution of rainwater with formaldehyde, when rain water is applied for tap water and miscellaneous purpose.

Pulsed wire discharge apparatus for mass production of copper nanopowders

A pulsed wire discharge (PWD) apparatus for the mass production of nanopowders has been developed. The apparatus has a continuous wire feeder, which is operated in synchronization with a discharging circuit. The apparatus is designed for operation at a maximum repetition rate of 1.4 Hz at a stored energy of 160 J. In the present study, Cu nanopowder was synthesized using the PWD apparatus and the performance of the apparatus was examined. Cu nanopowder of 2.0 g quantity was prepared in N(2) gas at 100 kPa for 90 s. The particle size distribution of the Cu nanopowder was analyzed by transmission electron microscopy and the mean surface diameter was determined to be 65 nm. The ratio of the production mass of the powder to input energy was 362 g/kW h.

The neural repressor NRSF/REST binds the PAH1 domain of the Sin3 corepressor by using its distinct short hydrophobic helix

In non-neuronal cells and neuronal progenitors, many neuron-specific genes are repressed by a neural restrictive silencer factor (NRSF)/repressor element 1 silencing transcription factor (REST), which is an essential transcriptional repressor recruiting the Sin3-HDAC complex. Sin3 contains four paired amphipathic helix (PAH) domains, PAH1, PAH2, PAH3 and PAH4. A specific target repressor for Sin3 is likely to bind to one of them independently. So far, only the tertiary structures of PAH2 domain complexes, when bound to the Sin3-interacting domains of Mad1 and HBP1, have been determined. Here, we reveal that the N-terminal repressor domain of NRSF/REST binds to the PAH1 domain of mSin3B, and determine the structure of the PAH1 domain associated with the NRSF/REST minimal repressor domain. Compared to the PAH2 structure, PAH1 holds a rather globular four-helix bundle structure with a semi-ordered C-terminal tail. In contrast to the amphipathic alpha-helix of Mad1 or HBP1 bound to PAH2, the short hydrophobic alpha-helix of NRSF/REST is captured in the cleft of PAH1. A nuclear hormone receptor corepressor, N-CoR has been found to bind to the PAH1 domain with a lower affinity than NRSF/REST by using its C-terminal region, which contains fewer hydrophobic amino acid residues than the NRSF/REST helix. For strong binding to a repressor, PAH1 seems to require a short alpha-helix consisting of mostly hydrophobic amino acid residues within the repressor. Each of the four PAH domains of Sin3 seems to interact with a characteristic helix of a specific repressor; PAH1 needs a mostly hydrophobic helix and PAH2 needs an amphipathic helix in each target repressor.

Growth induction of rat primary hepatocytes using antisense oligonucleotides

We examined growth control of adult and fetal hepatocytes by regulating the expression of cell-cycle-related proteins using antisense S-oligonucleotides to tumor suppressors retinoblastoma (RB) protein and p53, and cyclin-dependent kinase (CDK) inhibitors p21 and p27. The protein expression in both adult and fetal hepatocytes was significantly suppressed with the addition of corresponding antisense oligonucleotides at a concentration of 2.5 microM. For the evaluation of growth, 3H-thymidine incorporation and DNA content were measured and the results demonstrated that all the antisense oligonucleotides had growth-promoting effects and the promoting potential was equivalent or slightly greater than that with the addition of hepatocyte growth factor (HGF) (10 ng/ml). The growth-promoting effect of the antisense oligonucleotides was enhanced by HGF in both adult and fetal hepatocyte cultures, and the effects on hepatocyte growth were also observed in a suspension culture.

Direct interaction of NRSF with TBP: chromatin reorganization and core promoter repression for neuron-specific gene transcription

Neural restrictive silencer factor, NRSF (also known as REST) binds a neuronal cell type selective silencer element to mediate transcriptional repression of neuron-specific genes in non-neuronal cells and neuronal progenitors. Two repression domains (RD-1 and RD-2) occur in its N-terminal and C-terminal regions, respectively. RD-1 recruits mSin3 and HDAC, thereby inhibiting transcription by inducing reorganization of the chromatin structure. However, little is known about how such global repression becomes promoter-specific repression or whether the NRSF-HDAC complex can interact with transcriptional core factors at each specific promoter. Here we show evidence that NRSF interacts with core promoter factors, including TATA-binding protein (TBP). The NRSF-TBP interaction occurred between the linear segments of the N- and C-terminal-most portions of NRSF and the C-terminal half of TBP. A RD-2 mutant of NRSF lost the TBP-binding activity and was unable to repress transcription at an exogenously introduced TGTA promoter. These results indicate that the direct interaction between the NRSF C-terminal domain and TBP is essential for the C-terminal repression mechanism of NRSF. Thus, the RD-1 and RD-2 repression domains of NRSF utilize both chromatin-dependent and chromatin-independent mechanisms, which may be segregated at various stages of neural development and modulation.

Removal of small non-enveloped viruses by nanofiltration

BACKGROUND AND OBJECTIVES

Nanofiltration is one of the most effective virus reduction methods in the manufacturing process of plasma products. However, it is difficult to remove small viruses from high molecular weight protein preparations like immunoglobulin G or factor VIII complex by nanofiltration, because the size of the protein is similar to that of viruses. In order to separate the viruses from these proteins by nanofiltration, it is necessary to change the size of either one. In this study, we report that such non-enveloped viruses as human parvovirus B19 (B19), human encephalomyocarditis virus (EMC) or porcine parvovirus (PPV) aggregate in the presence of certain kinds of amino acids and could be easily removed by nanofiltration.

MATERIALS AND METHODS

0.3 M Glycine (or other amino acid) solution spiked with viruses was subjected to dead-end single filtration with a 35-nm pore-size filter. Virus removal by nanofiltration was either evaluated by PCR or by infectivity assay.

RESULTS

B19 in a 0.3 M glycine solution was reduced to 1:10(7.5) (7.5-log) by nanofiltration with a 35-nm pore-sized filter, whereas in PBS it was not reduced. Similarly, B19 was also reduced when suspended in other amino acids solutions. This effect was also confirmed with the other small non-enveloped viruses EMC or PPV. When 5% globulin or 5% albumin was added to a 0.3 M glycine solution, the removal rate was decreased.

CONCLUSIONS

These data suggest that viruses in the presence of certain kinds of amino acids could be aggregated and effectively removed by a filter that has a pore size larger than the size of the viruses.

Detection of maternal-fetal microchimerism in the inflammatory lesions of patients with Sjögren's syndrome

BACKGROUND

A possible relation between maternal-fetal microchimerism and autoimmune diseases with some similarities to chronic graft versus host disease (cGVHD) has been reported.

OBJECTIVE

To investigate whether cells with male DNA exist in female patients with Sjögren's syndrome (SS) as SS has clinical features similar to those of cGVHD.

METHODS

DNA was extracted from 27 samples of peripheral blood mononuclear cells (PBMC), 42 biopsy samples of labial salivary glands (LSG), and nine samples of bronchoalveolar lavage fluid (BALF) cells from 56 female patients with SS. The presence of male DNA was determined by nested polymerase chain reaction (PCR) and by fluorescence in situ hybridisation (FISH).

RESULTS

Among 56 female patients with SS, 42 patients had at least one male child. Among those 42 patients, none of the 22 PBMC but 10/28 (36%) LSG samples tested positive by PCR for the Y chromosome-specific sequence (p=0.0013). The Y chromosome-specific sequence was not detected in the samples of LSG in 10 patients without SS. In the BALF samples 2/9 (22%) patients with SS tested positive by PCR. Cells containing the Y chromosome were shown to exist in all the LSG specimens from three female patients with SS by FISH.

CONCLUSIONS

Maternal-fetal microchimerism was shown for the first time to exist in the salivary glands and lungs of female patients with SS in this study. The presence of non-host cells in the inflammatory lesions but not in the peripheral blood suggests a possible role for maternal-fetal microchimerism in the pathogenesis of SS.