Negative regulation of phagocytosis in macrophages by the CD47-SHPS-1 system

Src homology 2 domain-containing protein tyrosine phosphatase (SHP) substrate-1 (SHPS-1) is a transmembrane protein that is expressed predominantly in macrophages. Its extracellular region interacts with the transmembrane ligand CD47 expressed on the surface of adjacent cells, and its cytoplasmic region binds the protein tyrosine phosphatases SHP-1 and SHP-2. Phagocytosis of IgG- or complement-opsonized RBCs by peritoneal macrophages derived from mice that express a mutant SHPS-1 protein that lacks most of the cytoplasmic region was markedly enhanced compared with that apparent with wild-type macrophages. This effect was not observed either with CD47-deficient RBCs as the phagocytic target or in the presence of blocking Abs to SHPS-1. Depletion of SHPS-1 from wild-type macrophages by RNA interference also promoted FcgammaR-mediated phagocytosis of wild-type RBCs. Ligation of SHPS-1 on macrophages by CD47 on RBCs promoted tyrosine phosphorylation of SHPS-1 and its association with SHP-1, whereas tyrosine phosphorylation of SHPS-1 was markedly reduced in response to cross-linking of FcgammaRs. Treatment with inhibitors of PI3K or of Syk, but not with those of MEK or Src family kinases, abolished the enhancement of FcgammaR-mediated phagocytosis apparent in macrophages from SHPS-1 mutant mice. In contrast, FcgammaR-mediated tyrosine phosphorylation of Syk, Cbl, or the gamma subunit of FcR was similar in macrophages from wild-type and SHPS-1 mutant mice. These results suggest that ligation of SHPS-1 on macrophages by CD47 promotes the tyrosine phosphorylation of SHPS-1 and thereby prevents the FcgammaR-mediated disruption of the SHPS-1-SHP-1 complex, resulting in inhibition of phagocytosis. The inhibition of phagocytosis by the SHPS-1-SHP-1 complex may be mediated at the level of Syk or PI3K signaling.

Small hepatocellular carcinoma: treatment with US-guided intratumoral injection of acetic acid

PURPOSE

To assess the efficacy of ultrasound-guided percutaneous acetic acid injection (PAI) in the treatment of hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Results of a preliminary study in rats showed that the effectiveness of acetic acid in the destruction of hepatocytes plateaued at a concentration of 50%. Thus, PAI with 50% acetic acid was performed in 25 patients with solitary HCCs 3 cm or less in diameter. The viability of tumor cells after PAI was examined by means of contrast material-enhanced computed tomography (CT) and fine-needle biopsy in all patients. Two patients underwent partial hepatic resection.

RESULTS

No clinically significant complications occurred in 82 treatment sessions. All lesions became smaller after a mean of 23 months +/- 8 (standard deviation) of follow-up. There was no evidence of viable HCC at follow-up biopsy and CT. Two HCCs obtained by means of resection showed complete necrosis. The 1-year survival rate among 23 patients who did not undergo surgical treatment was 100%; the 2-year survival rate was 92%.

CONCLUSION

PAI may prove to be an effective therapy for small HCC.

Dynamics of intracellular granules with CD63-GFP in rat basophilic leukemia cells

CD63 is located on the basophilic granule membranes in resting basophils, mast cells, and platelets, and is also located on the plasma membranes of the cells. We constructed a CD63-GFP (green fluorescent protein) plasmid and introduced it into rat basophilic leukemia (RBL-2H3) cells to observe the movements of CD63 on degranulation. The movements of CD63-GFP were studied in living RBL cells by confocal laser scanning microscopy (CLSM). CD63-GFP, in which GFP was conjugated to the C-terminus of CD63, was located on both the granule membranes and the plasma membranes of RBL cells. The diameter of the fluorescent granules in the cytoplasm varied from 0.5 to 1.5 microm. Before antigen stimulation most granules with CD63-GFP hardly moved in RBL cells. However, after antigen stimulation the plasma membranes ruffled violently and the granules moved dramatically. They reached the plasma membranes in a few minutes and fused with them instantaneously. Analysis of the movement of each granule provided a new insight into the elementary process of degranulation. The velocity of the granule movement toward the plasma membranes on antigen stimulation was calculated to be 0.1+/-0.02 microm/s. This shows that the granules are able to reach the plasma membranes in 2 or 3 min if the diameter of the cells is 20 microm.

CD47 regulation of epithelial cell spreading and migration, and its signal transduction

CD47 is an integrin-associated penta-transmembrane protein that possesses an immunoglobulin-like domain in its extracellular region. We have now investigated the role of CD47 in the regulation of epithelial cell spreading and migration. CD47 is colocalized with E-cadherin at cell-cell adhesion sites of epithelial cells. A Ca2+ switch experiment showed that CD47 was endocytosed and then relocalized to cell-cell adhesion sites in a similar manner to E-cadherin. Such polarized localization of CD47 required the multiple spanning region of this protein. Forced expression of CD47 induced cell spreading with marked lamellipodium formation and resulted in both partial disruption of cell-cell adhesion and enhancement of the hepatocyte growth factor-stimulated scattering of Madin-Darby canine kidney cells. The CD47-induced cell spreading was blocked by inhibition of Src and mitogen-activated protein kinase kinase. Thus, these results suggest that CD47 participates in the regulation of cell-cell adhesion and cell migration through reorganization of the actin cytoskeleton in epithelial cells. This function of CD47 is mediated by the activation of Src and mitogen-activated protein kinase kinase.

Six novel P gene mutations and oculocutaneous albinism type 2 frequency in Japanese albino patients

Type 2 oculocutaneous albinism (OCA2) is an autosomal recessive disorder that results from mutations in the P gene that codes one of the melanosomal proteins, the function of which remains unknown. In this paper, we report the frequency of OCA2, 8%, among the Japanese albino population, six novel mutations containing four missense substitutions (P198L, P211L, R10W, M398I), and two splice site mutations (IVS15+1 G>A, IVS24-1 G>C). One of them, R10W, was within the putative signal peptide at the N-terminal of the P protein. This is the first report on the frequency of OCA2 in the Japanese albino population.

Multiple current dipole estimation using simulated annealing

A method for estimating electrical current distribution in the human brain using a multiple current dipole model is presented. A cost function for estimating multiple dipoles is proposed and a simulated annealing algorithm is used to obtain an acceptable solution. Computer simulation is used to evaluate the effectiveness of this method.

Change of embryotoxic susceptibility to di-n-butyltin dichloride in cultured rat embryos

Di-n-butylin dichloride (DBTCl), which is commonly used as heat and light stabilizer for polyvinyl chloride (PVC) plastics, is a teratogen in vivo. In the present study, the toxic effects were investigated of DBTCl on cultured rat embryos during three different stages of organogenesis. Rat embryos explanted on gestational day (GD) 8.5, GD 9.5, and GD 11.5 were cultured for 68, 46, and 48 h and were exposed to a range of DBTCl concentrations for the first 24, 46, and the last 46 h of culture, respectively. Significant decreases in the placental diameter at > or = 10 ng/ml and in the number of somite pairs and the morphological score at 30 ng/ml were noted in embryos cultured from GD 8.5. Significant decreases in the yolk sac diameter and the crown-rump length at 100 ng/ml, in the number of somite pairs at > or = 50 ng/ml, and in the morphological score at > or = 30 ng/ml were found in embryos cultured from GD 9.5. No adverse effects on these parameters were detected in embryos cultured from GD 11.5 even at 300 ng/ml. Dysmorphogenesis in embryos cultured from GD 8.5, GD 9.5, and GD 11.5 was observed at > or = 10, > or = 50, and 300 ng/ml, respectively. Incomplete turning and craniofacial defects in embryos cultured from GD 8.5 and GD 9.5 and defects of the forelimb buds and tail in embryos cultured from GD 11.5 were frequently observed. These results show that in vitro exposure to DBTCl interferes with normal development of embryos during three different stages of organogenesis and that susceptibility to the embryotoxicity, including the dysmorphogenic potential of DBTCl, varies with developmental stage.

Adult-onset Still's disease with prurigo pigmentosa-like skin eruption

A 34-year-old woman with adult-onset Still's disease (AOSD) developed prurigo pigmentosa-like lesions on her chest and upper back in addition to the typical rash of AOSD. A biopsy specimen taken from the upper back showed characteristic features of prurigo pigmentosa. The eruption and fever subsided immediately after the administration of 40 mg/day prednisolone, but arthralgia persisted even after intravenous pulse methylprednisolone therapy in combination with immunosuppressive drugs. Various atypical skin rashes, including prurigo pigmentosa-like lesions, have been reported in association with AOSD. Therefore, one should carefully follow the clinical course of a patient in order not to overlook these atypical cutaneous manifestations of AOSD.

Details of simulated annealing algorithm to estimate parameters of multiple current dipoles using biomagnetic data

The details of the simulated annealing algorithm proposed to estimate the parameters of multiple current dipoles using biomagnetic data are described. The effects of the choices of such numerical conditions as the amount of estimate transitions, the equilibrium criterion, and the temperature decrement on the algorithm's performance are discussed. Incorrect results from the computer simulation obtained with inappropriate choices of such conditions are presented. The verification of a near-optimum convergence by reheating and reannealing is demonstrated. A modification of this algorithm is proposed for implementation by parallel computer, and the validity of this parallel algorithm is demonstrated by computer simulation.

High-resolution image reconstruction method for time-of-flight positron emission tomography

We present a new image reconstruction method for time-of-flight positron emission tomography (TOF-PET). The TOF-PET measurement system is modelled using the continuous-discrete mapping model, and images are reconstructed using an algebraic technique. The proposed method can produce images with better spatial resolution than conventional methods based on the filtered backprojection method. Numerical simulation results show that accurate modelling of the measurement system improves the spatial resolution and the contrast recovery, while the utilization of TOF information improves the signal-to-noise ratios of images.

Parameter estimation for in vivo magnetic resonance spectroscopy (MRS) using simulated annealing

A method for estimating the spectral parameters from a noisy FID is proposed. The method uses a priori information concerning the lower and upper limits between which such parameters' values can exist. Computer simulation results show that, using the proposed method, values of the spectral parameters can be accurately estimated from a noisy FID.

Membrane fluidity and lipid hapten structure of liposomes affect calcium signals in antigen-specific B cells

Antigen-specific B-cell clones directed against a 2,4,6-trinitrophenyl (TNP) hapten have been established [Hamano et al. (1990) J. Immunol. 144, 811-815]. We measured here the cytosolic free calcium ion concentration ([CA2+]i) in these B-cell clones after antigen stimulation. Trinitrophenylated liposomes with different length spacers between TNP and phosphatidylethanolamine (TNP-Cn-PE) increased cytosolic free calcium concentration in TNP-specific B cells (clone TP67.21). The magnitude of calcium signals depended on the length of the spacer. TNP-C6-PE in dipalmitoylphosphatidylcholine (DPPC) liposomes triggered larger calcium signals in B cells than TNP-Cn-PE with n = 0, 4, 8, or 12. The magnitude of the calcium signals was strongly dependent on the fluidity of the liposome membranes. TNP-C6-PE in the solid DPPC liposomes triggered the calcium signals in B cells 50-100 times as efficiently as TNP-C6-PE in the fluid dimyristoylphosphatidylcholine liposomes. The difference between the solid liposomes and the fluid liposomes was more pronounced in triggering calcium signals in B cells than in antibody binding to these liposomes.

Holography of 3D surface reconstructed CT images

A multiplex hologram (cylindrical holographic stereogram) was successfully made from three-dimensional (3D) surface reconstruction CT images of a child with plagiocephaly. This method appears to be suitable as one of the projectional aids of 3D surface reconstruction CT images that are proving useful in plastic and reconstructive surgery. The principle of the method is described. Also discussed is the possibility of developing a computer-aided hologram synthesizing system that could be used for images obtained with U-arm X-ray equipment (by either cinefilm, or videotape, or digital subtraction angiography) or by CT as well as MR. For practical use, it is necessary for the hologram to be synthesized in a short time. One of the key problems in developing such a machine is the need for an incoherent-to-coherent image converter.

A case of pigmented dermatofibrosarcoma protuberans (Bednar tumor)

The present paper reports a 67-year-old male with pigmented dermatofibrosarcoma protuberans (Bednar tumor) on his right shoulder. The lesion had recurred twice. Clinically, the lesion was a reddish-brown, exophytic, multilobular, firm nodule with an irregular surface, which measured 6.4 x 4.2 cm. Histologically, the proliferated fibroblasts showed a cartwheel pattern and stained positively with CD34, similar to those of a common dermatofibrosarcoma protuberance. However, many melanin-bearing cells that were positive for the S-100 protein were found intermingled among the tumor cells. Based on these findings, we concluded that the clinical manifestations, level of malignancy, and cytological features, as well as the exception of melanin-bearing dendritic cells associated with pigmented dermatofibrosarcoma protuberans, suggest a common dermatofibrosarcoma protuberans. This supports the hypothesis that pigmented dermatofibrosarcoma protuberans is a pigmented variant of dermatofibrosarcoma protuberans. Thus, this type of tumor is not benign, but is an intermediate malignant tumor.

Analysis of the cost function used in simulated annealing for CT image reconstruction

When simulated annealing is applied to an ill-posed reconstruction of computer tomography images, the cost function should be appropriately modified to suppress artifacts arising from the ambiguity of null components. This paper shows such modification of the cost function and proves its performance through singular value decomposition analysis. Computer simulation shows good agreement with the analysis.

Sarcoma botryoides of the uterine cervix: a case report

Rhabdomyosarcoma of the uterine cervix is a very rare disease. We present a case of rhabdomyosarcoma (botryoide type) arising from the introitus of the uterine cervix, and make a discussion on the diagnosis, treatment and involving factors of prognosis.

Effects of phenylephrine and prazosin on axial movement of the rat incisor and arterial blood pressure

We investigated the dose-response effects of phenylephrine and antagonistic effects of prazosin on axial movement of the rat incisor and arterial blood pressure. Phenylephrine caused a temporal extrusive tooth movement and an increase in blood pressure at all doses. With increasing phenylephrine doses, the maximum extrusive tooth movement and maximum increase in blood pressure were enhanced. The maximum extrusive tooth movement and increase in blood pressure induced by phenylephrine were markedly suppressed after pretreatment with prazosin. These results suggested that extrusive tooth movement is closely related to the rise in blood pressure due to stimulation of vascular alpha1-receptors.

Holographic three-dimensional printer: new method

We propose a holographic three-dimensional (3-D) printer that produces 3-D hard copies of computer data. A new technique for synthesizing a holographic stereogram (HS) has been invented for the purpose of making accurate hard copies of 3-D objects. The flat-format, Lippmann-type HS is printed by one optical step and is ideally suitable for 3-D printer application. This type of HS has both horizontal and vertical parallaxes so that the reconstructed image is free from distortion. The principle and the image quality of this type of HS are described, and a reconstructed image from this type of HS with 160 x 128 elements is experimentally demonstrated. The systematic constitution of a holographic 3-D printer is also discussed.

Multiple Re-entry Closures After TEVAR for Ruptured Chronic Post-dissection Thoraco-abdominal Aortic Aneurysm

Introduction

Although thoracic endovascular aortic repair (TEVAR) has become a promising treatment for complicated acute type B dissection, its role in treating chronic post-dissection thoraco-abdominal aortic aneurysm (TAA) is still limited owing to persistent retrograde flow into the false lumen (FL) through abdominal or iliac re-entry tears.

Report

A case of chronic post-dissection TAA treatment, in which a dilated descending FL ruptured into the left thorax, is described. The primary entry tear was closed by emergency TEVAR and multiple abdominal re-entries were closed by EVAR. In addition, major re-entries at the detached right renal artery and iliac bifurcation were closed using covered stents. To close re-entries as far as possible, EVAR was carried out using the chimney technique, and additional aortic extenders were placed above the coeliac artery. A few re-entries remained, but complete FL thrombosis of the rupture site was achieved. Follow-up computed tomography showed significant shrinkage of the FL.

Discussion

In treating post-dissection TAA, entry closure by TEVAR is sometimes insufficient, owing to persistent retrograde flow into the FL from abdominal or iliac re-entries. Adjunctive techniques are needed to close these distal re-entries to obtain complete FL exclusion, especially in rupture cases. Recently, encouraging results of complete coverage of the thoraco-abdominal aorta with fenestrated or branched endografts have been reported; however, the widespread employment of such techniques appears to be limited owing to technical difficulties. The present method with multiple re-entry closures using off the shelf and immediately available devices is an alternative for the endovascular treatment of post-dissection TAA, especially in the emergency setting.

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A case of ruptured post-dissection thoraco-abdominal aneurysm was treated.

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Following entry closure by TEVAR, EVAR was performed to close multiple re-entries.

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Re-entries at the renal artery ostium and iliac artery were closed by covered stents.

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Complementary re-entry closure techniques are essential to treat false lumen rupture.

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This report demonstrates successful re-entry closure techniques following TEVAR.

In vitro study of teratogenic effects of caffeine on cultured rat embryos and embryonic cells

The teratogenic potential of caffeine was examined in vitro by a whole embryo culture system (WECS) and an embryonic cell culture system (micromas teratogen assay: MTA) in the rat. In the WECS, hyperemia of the tail, and a reduction of the placental size was induced by caffeine at concentrations higher than 50 micrograms/ml; hypoplasia of the forelimb bud was induced at concentrations higher than 100 micrograms/ml; hematoma in the yolk sac and dysmorphogenesis of the fore- and hind-limb buds, prosencephalon and tail were induced by 200 micrograms/ml caffeine. In the MTA, even with 200 micrograms/ml caffeine, the toxicological parameters obtained by proliferation and differentiation assays of the midbrain and limb bud cells were almost the same as in the control. In conclusion, caffeine induced various morphological anomalies, but did not affect proliferation or differentiation of cells in these experimental systems.

A proposal of an off-line PACS based on a personal database

Problems with picture archiving and communication systems (PACS) are focused and an off-line PACS of practical value is proposed in this paper. This system is based on the personal database where each patient has his/her own recording medium. This medium files all medical information as well as images of value, and is carried with a patient through hospital. Advantages over the conventional or on-line PACS communicating through a network are discussed and a possibility of practical use is analysed showing a prototype system. The biggest advantage of this system is quick and easy access to the images of concern and a small amount of cost for initial investment. It is also pointed out that the format of the data recording on the disk has to be standardized so that this system could be used for a medical care system over a wide area.

Optical implementation of the stream cipher based on the irreversible cellular automata algorithm

A hybrid optical scheme for efficient hardware implementation of the one-dimensional, three-neighborhood binary cellular automata rule a(i)(?) =a(i-1)XOR(a(i)OR a(i+1)) -based stream cipher is proposed. The system makes full use of the parallel, space-invariant, cascadable, and modular structure of the algorithm and is simple, robust, and compact. The number of cellular automata arrays can be as large as the number of pixels on the spatial light modulator, which results in an increase in speed (number of bits operated in parallel) and security (key length). The system can be made fully optical with the use of an optically addressable spatial light modulator for the input plane and for the nonlinear threshold element.

Three-dimensional reconstruction of a bone image from cone beam projections

Three-dimensional reconstruction of a bone image is important in medicine to facilitate making artificial bones by numerical control and to achieve computer simulations of surgical operations. Instead of gathering sectional tomograms obtained by computer tomography, a direct 3-D reconstruction, which is much better in terms of higher spatial resolution and smaller X-ray dosage, is used to extract the bone's shape. A proposal and an experimental result are presented in this paper.

Use of color image correlation in the retrieval of gastric surface topography by endoscopic stereopair matching

We propose finding an optimal generalized color plane to carry out digital color image correlation. We seek the optimization of the correlation peak's sharpness and, for the purpose of analysis, we make some assumptions regarding the statistical properties of images to be considered. The analysis leads to a simple solution involving a projection onto the Karhunen-Loeve vectors corresponding to the smallest eigenvalues of the interprimary colors covariance matrix. We use our results in the retrieval of the gastric mucosal surface structure from stereopairs taken through an endoscope. Study of the statistics of the endoscope images shows that the assumptions used earlier can be applied to this type of image. We present some results of stereopair matching with color image correlation. We conclude by proposing a pseudo-3-D surface reconstruction of the gastric surface by mapping the endoscopic image onto the retrieved elevation information.