Bayesian inference of ion velocity distribution function from laser-induced fluorescence spectra.

The velocity distribution function is a statistical description that connects particle kinetics and macroscopic parameters in many-body systems. Laser-induced fluorescence (LIF) spectroscopy is utilized to measure the local velocity distribution function in spatially inhomogeneous plasmas. However, the analytic form of such a function for the system of interest is not always clear under the intricate factors in non-equilibrium states. Here, we propose a novel approach to select the valid form of the velocity distribution function based on Bayesian statistics. We formulate the Bayesian inference of ion velocity distribution function and apply it to LIF spectra locally observed at several positions in a linear magnetized plasma. We demonstrate evaluating the spatial inhomogeneity by verifying each analytic form of the local velocity distribution function. Our approach is widely applicable to experimentally establish the velocity distribution function in plasmas and fluids, including gases and liquids.

High-impedance wire grid method to study spatiotemporal behavior of hot electron clump generated in a plasma.

High-impedance Wire Grid (HIWG) detector has been developed to study spatiotemporal behavior of a hot electron clump generated in an electron cyclotron resonance (ECR) plasma. By measuring the floating potentials of the wire electrodes, and generating structure matrix made of geometrical means of the floating potentials, the HIWG detector reconstructs the spatial distribution of high-temperature electron clump at an arbitrary instant of time. Time slices of the spike event in floating potential revealed the growth and decay process of a hot spot occurs in an ECR plasma.

Experimental studies on ion acceleration and stream line detachment in a diverging magnetic field.

The flow structure of ions in a diverging magnetic field has been experimentally studied in an electron cyclotron resonance plasma. The flow velocity field of ions has been measured with directional Langmuir probes calibrated with the laser induced fluorescence spectroscopy. For low ion-temperature plasmas, it is concluded that the ion acceleration due to the axial electric field is important compared with that of gas dynamic effect. It has also been found that the detachment of ion stream line from the magnetic field line takes place when the parameter |f(ci)L(B)∕V(i)| becomes order unity, where f(ci), L(B), and V(i) are the ion cyclotron frequency, the characteristic scale length of magnetic field inhomogeneity, and the ion flow velocity, respectively. In the detachment region, a radial electric field is generated in the plasma and the ions move straight with the E×B rotation driven by the radial electric field.

[Left atrial myxoma surgically resected in acute phase of hemorrhagic cerebral infarction; report of a case].

A 61-year-old man who had been suffered from several episodes of cerebral infarction for 3 years complained of left-sided paresthesia and was pointed out hemorrhagic infarction in the right frontal area of the brain by computed tomography (CT) and magnetic resonance imaging (MRI). The echocardiography showed left atrial mass 9 cm in length attaching to the atrial septum, which was diagnosed as left atrial myxoma causing cerebral embolism. As serial MRI showed frequent episode of cerebral infarction, we performed surgical resection of the cardiac tumor on the 10th day after the onset of the neurological symptom. Anticoagulation during cardiopulmonary bypass was maintained with 1.5 mg/kg of heparin sodium and 80 mg/hour of nafamostat mesilate (FUT). Postoperative course was uneventful without neurological deterioration.

Fine positioning of a poloidal probe array.

Multipoint detection is an essential requirement for investigating plasma turbulence which is a highly nonlinear phenomenon in space and time. We have fabricated an array of 64-channel poloidal probes surrounding the linear cylindrical plasma named LMD-U in order to study turbulence properties, particularly the nonlinear mode couplings, in the domain of poloidal wave number and frequency. However, misalignments of probe tips produce spurious modes, which do not exist in the real plasma, to distort the precise wave number measurements. The paper presents the description of the 64-channel poloidal probe array with means to adjust the probe positions, with discussion on the effects of the misalignments on the wave number measurements.

[A case of encephalitis with MRI abnormalities localized in the bilateral amygdala and hippocampus].

We report a patient with encephalitis who showed anterograde and retrograde amnesia with MRI abnormalities localized in the bilateral amygdala (AM) and hippocampus (HIPP). A 25-year-old man suddenly experienced a generalized tonic-clonic seizure (GTCS). He was admitted because of increasing lethargy with two further GTCSs during the following 6 days. The patient had high fever, and neurological examination revealed somnolence, disorientation, amnesia, and nuchal stiffness. MRI revealed bilateral symmetrical abnormalities localized in the AM and HIPP, which showed low intensity on T1-weighted images and high intensity on T2-weighted images. Cerebrospinal fluid examination showed a mildly elevated cell count. We suspected herpes simplex virus type I encephalitis and began treatment with acyclovir. After the patient regained a clear consciousness, his antero- and retrograde amnesia continued for several months. The MRI abnormality became less distinct with the improvement of amnesia. We consider that the MRI abnormality was indicative of inflammation and edema, and that the lesion in the AM and HIPP had induced the amnesia.

Meningeal hamartoma of the scalp. A variant of primary cutaneous meningioma.

A case of meningeal hamartoma of the scalp is reported. A 15-year-old girl was admitted complaining of scalp nodules in the midline occipital region. A midline skull defect was found under the nodular lesions. Histologically, the mass had a fibrocollagenous tract extending to the dura and showed an admixture of mature adipose tissue, small vessels, strands of fibrocollagenous tissue, and scattered foci of meningocytes. Immunohistochemically, the meningocytes desmosomes, interdigitating processes, and intermediate filaments. The patient's brother also had the meningeal hamartoma of the scalp. Meningeal hamartoma as a variant of primary cutaneous meningioma is extremely rare, and this is the first report of such a case in Japan.

[Study on recombinant BCG].

For the purpose to establish the system to express foreign antigen from Mycobacterium bovis BCG. We have cloned, sequenced and expressed genes for secreting proteins, alpha antigen, MPB64, MPB57 and MPB70 from M. bovis BCG. The upstreams and structural genes were characterized. The gene for alpha antigen of Mycobacterium kansasii was also characterized. The gene for alpha antigen of M. kansasii (k-alpha) was chosen for the further study at first. This gene was fused with shuttle plasmid PIJ666-PAL5000 obtained from T. Kisser and transfected to M. bovis BCG (Tokyo). Transformant was obtained by a selection with kanamycin. It was able to secrete k-alpha antigen. DNA-containing a B-cell epitope (Glu-12-Leu-Asp-Arg-Trp-Glu-Lys-Ile-19) of human immunodeficiency virus type 1 P17 gag was fused to this vector at C terminal of k-alpha. Using this vector, we have succeeded to express foreign antigen in M. bovis BCG. The products were analyzed in one or two dimensional electro-phoresis. The results thus obtained will be reported elsewhere.

Establishment of a foreign antigen secretion system in mycobacteria.

In order to develop recombinant Mycobacterium bovis BCG into a useful multivaccine vehicle, we established a foreign antigen secretion system in mycobacteria in which an extracellular alpha antigen of Mycobacterium kansasii was utilized as a carrier. By using this system, a B-cell epitope (Glu-12-Leu-Asp-Arg-Trp-Glu-Lys-Ile-19) of human immunodeficiency virus type 1 p17gag, which was identified by a fusion protein-based method, has been successfully obtained from BCG along with the alpha antigen. This is the first report of expression and secretion of a foreign viral antigen from BCG. It is possible that the system can become a universal vaccination vehicle applicable to protection against various infectious diseases.

Cloning and expression of the gene for the cross-reactive alpha antigen of Mycobacterium kansasii.

The gene for the extracellular alpha antigen of Mycobacterium kansasii was cloned by using the alpha-antigen gene fragments of M. bovis BCG as probes. Gene analysis revealed that this gene encodes 325 amino acid residues, including 40 amino acids for the signal peptide, followed by 285 amino acids for the mature protein. A comparison of the nucleotide sequences of the genes isolated from these two mycobacterial species showed that the levels of DNA and amino acid homology were 84.8 and 89.1%, respectively. The hydropathy profiles were also compared, and two highly changed hydrophilic regions were observed, which might account for the antigenic diversity of this antigen or its acquirement of antigenic specificity.

Complete nucleotide sequence of immunogenic protein MPB70 from Mycobacterium bovis BCG.

The extracellular protein MPB70 is a heat-stable immunogenic protein which was found in the culture filtrate of Mycobacterium bovis BCG Japanese. We determined the complete nt and aa sequences of MPB70 and correlated with the previously reported data. The N-terminal sequence revealed that the signal peptide (SP) consisted of 30 aa and that the mature protein had 163 aa with a molecular weight of 16,305. The SP displayed a characteristic feature of an Ala-rich property which would be efficient in a SP function.

Cloning and characterization of the gene for immunogenic protein MPB64 of Mycobacterium bovis BCG.

The gene for immunogenic protein MPB64 found in culture filtrates of only Mycobacterium tuberculosis and some strains of Mycobacterium bovis BCG was cloned by using a single-probe method and was sequenced. The gene analysis revealed that the structural gene for MPB64 consisted of 618 base pairs, and its deduced molecular weight was 22,400. Twenty-two amino acids for a putative signal peptide and 205 amino acids for the MPB64 protein were observed. In the coding region, the third letter of the codon showed a biased codon and a high G+C content (78.5%). The gene was expressed in Escherichia coli by using an E. coli expression vector. The product showed migration similar to that of the authentic MPB64 protein by electrophoresis and reacted with the polyclonal and the monoclonal antibodies raised against the MPB64 protein. The strict specificity of MPB64 could be applied to immunodiagnosis of tuberculosis.

Immunogenic protein MPB57 from Mycobacterium bovis BCG: molecular cloning, nucleotide sequence and expression.

Using a single-probe method, we have cloned the gene for an immunogenic MPB57 protein of Mycobacterium bovis BCG. The nucleotide sequence includes an ORF of 300 base pairs encoding a protein of 99 amino acids with an Mr of 10,818. This cloned gene was expressed in an Escherichia coli expression vector to give a mature protein which reacted with a polyclonal antibody raised against MPB57.

Extensive proliferation of subsequently injected marrow cells in parental-to-F1 hematopoietic chimeras that restored normal stem cell concentration after initial transplantation.

We investigated the fate of donor stem cells that were injected into hosts with a normal concentration of spleen colony-forming unit (CFU-S). Radiation chimeras were used as hosts. When CFU-S concentration in the marrow and spleen recovered to preirradiation levels after the initial bone marrow transplantation, the subsequent transplantation was done without reirradiation. Giant granules of beige C57B1/6 (bg) mice were used as a marker and proliferation and differentiation of the stem cells of the subsequent donor origin were evaluated by measuring the proportion of neutrophils with giant granules. No beige-type neutrophils were detectable at week 24 after transplantation of 5 X 10(7) marrow cells from bg mice to intact (WB X C57B1/6)F1 (F1) mice, which were used as control recipients. In contrast, transplantation of 5 X 10(7) marrow cells to radiation chimeras resulted in the appearance of neutrophils of second-donor origin. The proportion of beige-type neutrophils was 12% at week 24 after transplantation of bg marrow cells to F1-to-F1 (syngenic) or C57B1/6-+/+-to-bg (B6-to-bg) (congenic) chimeras; the proportion of beige-type neutrophils was 43% when bg marrow cells were transplanted to B6-to-F1 semiallogenic chimeras; the proportion of normal-type neutrophils was 82% when F1 marrow cells were injected to bg-to-F1 semiallogenic chimeras. Thus, the interaction of the host hematopoietic microenvironment with the stem cells of the initial donor as well as with the stem cells of the second donor seems to influence the proliferation and differentiation of the latter stem cells.