Wedging of vertebral bodies at the thoracolumbar junction in asymptomatic healthy subjects on magnetic resonance imaging

Purpose

Wedging of the vertebral body on radiological examination is a valuable indicator of a vertebral compression fracture, although it can also be observed in subjects with no history of trauma. The purpose of this study was to elucidate the normative value of vertebral wedging at the thoracolumbar junction in asymptomatic healthy subjects for differential diagnosis of vertebral compression fractures using MRI.

Methods

A total of 115 subjects without back pain at the time of the examination and without history of spinal trauma was included (68 males, 47 females, mean age 49.5?years). They underwent MRI of the thoracic and lumbar spine, and the ratio of anterior vertical height to posterior vertical height of the vertebral body (APR) was determined from T10 to L2 on T2 weighted sagittal images.

Results

APR was 0.92?±?0.08 at T10, 0.92?±?0.08 at T11, 0.90?±?0.06 at T12, 0.89?±?0.06 at L1, and 0.90?±?0.07 at L2, indicating that vertebral bodies at the thoracolumbar junction appear wedge-shaped rather than rectangular. Males, thinner subjects, smokers, and subjects with abnormalities of the endplates such as a Schmorl nodule had a significantly smaller APR than females, fatter subjects, non-smokers, and those without endplate abnormalities.

Conclusion

The normative values of APR obtained in the present study can represent a valuable reference in the diagnosis of vertebral compression fracture to help prevent confusion with physiological vertebral wedging.     

Spatio-temporal detachment of single cells using microarrayed transparent electrodes

This paper describes a dynamic cell manipulation approach by which cells can be selectively detached from transparent indium tin oxide (ITO) electrodes via electrochemical desorption of a self-assembled monolayer (SAM) of alkanethiol. Changes in the surface properties of ITO following modification and electrical desorption of the SAM were characterized. By using these reactions on ITO, cells were readily attached and then detached from ITO electrodes in a very rapid manner, with greater than 90% of the cells being detached within 5?min. Furthermore, we fabricated micropatterns of ITO electrodes using photolithography. Cells on the micropatterned ITO electrodes could be detached with single-cell resolution. This approach could potentially lead to on-demand harvesting or elimination of one population from others under microscopy, for a wide range of purposes.     

Changing pulsatility by delaying the rotational speed phasing of a rotary left ventricular assist device

Continuous-flow left ventricular assist devices (LVADs) have improved the prognosis of end-stage heart failure. However, continuous-flow LVADs diminish pulsatility, which possibly result in bleeding, aortic insufficiency, and other adverse effects. We previously developed a novel control system for a continuous-flow LVAD (EVAHEART^®; Sun Medical), and demonstrated that we could create sufficient pulsatility by increasing its rotational speed (RS) in the systolic phase (Pulsatile Mode) in the normal heart model. Here, we aimed to evaluate differences between systolic assist with advanced and delayed loads by shifting the timing of increased RS. We implanted EVAHEART in six goats (55.3 ± 4.3 kg) with normal hearts. We reduced their heart rates to <60 bpm using propranolol and controlled the heart rates at 80 and 120 bpm using ventricular pacing. We shifted the timing of increasing RS from ?60 to +60 ms in the systolic phase. We found significant increases in all the following parameters when assessments of delayed timing (+60 ms) were compared with assessments of advanced timing (?60 ms): pulse pressure, mean dP/dt max of aortic pressure, and energy-equivalent pulse pressure. During continuous-flow LVAD support, pulsatility can be controlled using a rotary pump. In particular, pulsatility can be shifted by delaying increased RS.     

Cloning and Characterization of a Nonhemolytic Phospholipase C Gene from Burkholderia pseudomallei

We cloned and characterized a phosphatidylcholine-hydrolyzing phospholipase C (PC-PLC) gene from Burkholderia pseudomallei. DNA sequence analysis of the gene indicated an open reading frame coding for 700 amino acids with a 34-amino-acid signal peptide. When cleaved, this yields a secreted 73-kDa mature protein. The deduced amino acid sequence exhibited 48% similarity to that of a nonhemolytic PLC from Pseudomonas aeruginosa. The expressed PC-PLC was heat stable, nonhemolytic for sheep erythrocytes, and active between pH 2 and 8. Western blot analysis with sera from melioidosis patients indicated that they produced immunoglobulin M antibodies against this PC-PLC protein.     

CDX2 expression is progressively decreased in human gastric intestinal metaplasia, dysplasia and cancer.

Intestinal metaplasia is a key event in multistep gastric carcinogenesis. CDX2, a master regulator of intestinal phenotype, was shown to play a tumor-suppressive role in colon cancer. However, it was reported to be expressed in nearly all gastric intestinal metaplasia and many gastric cancers. As CDX2 is differentially expressed in normal stomach and intestine, we sought to relate the CDX2 expression to gastrointestinal differentiation along gastric carcinogenesis. The expression of CDX2 protein in gastric intestinal metaplasia, dysplasia and cancer was examined and related to their gastrointestinal differentiation. CDX2 expression was significantly decreased in incomplete intestinal metaplasia, which expresses both gastric mucins (MUC5AC and MUC6) and intestinal mucin (MUC2), compared with complete intestinal metaplasia, which expresses intestinal mucin (MUC2) only. Although incomplete intestinal metaplasia morphologically resembles colon, its CDX2 expression was apparently lower than that in the normal colon. Moreover, CDX2 expression was progressively reduced in gastric dysplasia and cancer. The CDX2 expression in gastric cancer was also inversely correlated with the expression of gastric mucins. As incomplete intestinal metaplasia is associated with higher risk of gastric cancer, its lower CDX2 expression compared with that in complete intestinal metaplasia and normal colon epithelium resolved the current contradiction between the tumor-suppressive role of CDX2 in the colon and the high prevalence of CDX2 in intestinal metaplasia. Further decrease of CDX2 expression in gastric dysplasia and cancer suggests that CDX2 plays a similar anticarcinogenic role in intestinal metaplasia as it does in colon. Intestinal metaplasia or dysplasia with low expression of CDX2 may serve as predictive markers for gastric cancer.     

Comparison of hepatitis B virus subgenotypes in patients with acute and chronic hepatitis B and absence of lamivudine-resistant strains in acute hepatitis B in Japan

Hepatitis B virus (HBV) has been classified into eight genotypes and can be further divided into several subgenotypes that have different geographic distributions. Because of increased human migration, the prevalence of rare subgenotypes is increasing in Japanese patients with acute hepatitis B. Lamivudine-resistant strains of HBV have begun to emerge in association with chronic hepatitis B. The aim of this study was to investigate the distribution of HBV subgenotypes and lamivudine-resistant strains in patients in Japan with acute hepatitis B. One hundred twenty-three patients with acute hepatitis B and 123 with chronic hepatitis B were studied. HBV subgenotypes and lamivudine-resistance mutations were determined by direct sequencing of the preS and polymerase region, respectively. HBV subgenotypes Aa (n=3), Ae (n=23), Ba (n=7), Bj (n=3), Cs (n=7), Ce (n=76), D (n=2), and H (n=2) were detected in patients with acute hepatitis. In patients with chronic hepatitis, HBV subgenotypes Ae (n=4), Ba (n=1), Bj (n=18), and Ce (n=100) were found. Non-common Japanese subgenotypes, that is, non-Bj and non-Ce, were detected more frequently in patients with acute hepatitis (35.8%) than in patients with chronic hepatitis (4.1%) (Odds ratio, 0.076; 95%CI, 0.029-0.200; P<0.0001). Lamivudine-resistance mutations were detected in chronic hepatitis patients with breakthrough hepatitis but not in other patients. In conclusion, the prevalence of uncommon Japanese HBV subgenotypes is expected to increase, although lamivudine-resistant strains have not yet been found in patients with acute hepatitis B.     

Short-term culture and gammaH2AX flow cytometry determine differences in individual radiosensitivity in human peripheral T lymphocytes

Histone H2AX, a subfamily of histone H2A, is phosphorylated and forms proteinaceous repair foci at the sites of DNA double-strand breaks in response to genotoxic insults, such as ionizing radiation. This process is believed to play a key role in the repair of DNA damage. In this study, we established a flow cytometry (FCM) system for measuring radiation-induced phosphorylated histone H2AX (gammaH2AX) in cultured human T lymphocytes to evaluate individual radiation sensitivity in vitro. Irradiation of short-term ( approximately 7 days) cultured T lymphocytes exhibited significant interindividual, but not interexperimental, differences in the cellular content of gammaH2AX 6 hr after 4 Gy of X-irradiation in three independent experiments using peripheral blood lymphocytes from six healthy donors. However, these differences were not as marked in uncultured lymphocytes, or lymphocytes that were cultured for a prolonged period ( approximately 13 days). The variation of gammaH2AX focus formation in lymphocytes of individuals was reproducible, with differences reaching about 1.5-fold following 7 days of culture. Therefore, the FCM-based gammaH2AX measurement appeared to reflect both the temporal course and the amount of DNA damage within the irradiated lymphocytes. Further, we confirmed that the differences in residual lymphocyte subsets were not involved in individual radiosensitivity. These results suggest that the FCM-based gammaH2AX assay using cultured T lymphocytes might be useful for the rapid and reliable assessment of individual radiation sensitivity involved in DNA damage repair.     

A rare congenital anomaly, bridge-like appendiceal fistula to the terminal ileum, demonstrated by MDCT

Although appendiceal anatomical anomalies are very rare, understanding of the anatomical details of these anomalies is important for surgery. In this case report, we present images from multi-detector row computed tomography (MDCT) and histological findings of a rare anatomical appendiceal anomaly originating from the cecum and opening into the terminal ileum like a bridge. These anatomical details were clearly depicted on MDCT with multi-planar reconstruction. MDCT demonstrated a communication between the appendix and terminal ileum. Histological analysis revealed that a normal mucosal layer was maintained from the appendix to the connected ileum, without any evidence of inflammatory or neoplastic changes, and only thickening of the muscular layer of the appendix was identified. Based on these histological findings, the appendix was considered to represent an anatomical anomaly rather than secondary fistula caused by inflammation or neoplasm, which has not yet been reported.     

Development and evaluation of endurance test system for ventricular assist devices

We developed a novel endurance test system that can arbitrarily set various circulatory conditions and has durability and stability for long-term continuous evaluation of ventricular assist devices (VADs), and we evaluated its fundamental performance and prolonged durability and stability. The circulation circuit of the present endurance test system consisted of a pulsatile pump with a small closed chamber (SCC), a closed chamber, a reservoir and an electromagnetic proportional valve. Two duckbill valves were mounted in the inlet and outlet of the pulsatile pump. The features of the circulation circuit are as follows: (1) the components of the circulation circuit consist of optimized industrial devices, giving durability; (2) the pulsatile pump can change the heart rate and stroke length (SL), as well as its compliance using the SCC. Therefore, the endurance test system can quantitatively reproduce various circulatory conditions. The range of reproducible circulatory conditions in the endurance test circuit was examined in terms of fundamental performance. Additionally, continuous operation for 6 months was performed in order to evaluate the durability and stability. The circulation circuit was able to set up a wide range of pressure and total flow conditions using the SCC and adjusting the pulsatile pump SL. The long-term continuous operation test demonstrated that stable, continuous operation for 6 months was possible without leakage or industrial device failure. The newly developed endurance test system demonstrated a wide range of reproducible circulatory conditions, durability and stability, and is a promising approach for evaluating the basic characteristics of VADs.     

Moving Mesh Method for Reconstructing Some Spread Sources in the Brain

The purpose of this paper is to propose a new algorithm for the analysis of biomagnetic field data obtained from magnetoencephalography (MEG) measurements. This new method overcomes two major problems faced by the current method of data analysis. The first problem is the need to determine the number of sites of brain activity before calculations can be performed. The second problem is inability of the analysis to provide any information regarding the volume of the brain activity. The new data analysis method, called the Moving Mesh Method (MMM), is capable of analyzing MEG data without the need to determine the number of sources beforehand. In addition, the MMM determines the location of brain activity as a three dimensional volume, instead of as a point source of activity. The MMM uses an iterative method of calculating the position of the sources to achieve greater accuracy, and a regularized g-inverse matrix to stabilize its solution. The feasibility of the MMM was examined by two methods. First, a computer simulation was used to confirm the MMM's capability to analyzing MEG data. In the second experiment, the MMM was applied to analyze somatosensory evoked fields obtained using a new imaging system (Shimadzu Biomagnetic Imaging System, Model-100). From the interpretation of the results, we have concluded that the MMM is a feasible method of biomagnetic data analysis.