Novel multipole Wien filter as three-dimensional spin manipulator

Spin polarized electron beam is often used in material characterizations which relates to magnetism as well as in the high energy particle physics. The manipulation of the spin polarization toward the arbitrary direction is indispensable in such studies. In the present work, a novel multipole Wien filter is proposed as the three-dimensional spin manipulator, and a prototype 8-pole Wien filter is developed. It is applied to spin polarized low energy electron microscopy, and the variation of the magnetic contrast with managing the spin polarization is evaluated. It is confirmed that the novel multipole Wien filter can manipulate the spin polarization three-dimensionally.

Step contrast reversal in LEEM during Pb deposition on W(110)

Anomalous step contrast in low energy electron microscopy (LEEM) images observed during Pb deposition on a W(110) surface is discussed. The steps are dark on the clean surface, and become bright by Pb deposition at about 200 °C. The contrast reversal is related to the presence of a two-dimensional (2D) Pb gas on the surface and its atomic density distribution. Upon further deposition the steps become dark again and show an anomalous intensity profile. This change is attributed to the 2D crystallization process.

Magnetic field switching between the two orbital-ordered states in DyVO3

The critical phase competition between different spin-orbital-ordered states has been investigated for the DyVO3 single crystal. As temperature is lowered, the compound exhibits a reentrant spin and orbital ordering (SO and OO) transition: C-->G-->C type for SO and G-->C-->G type for OO. It was found that a magnetic field also drives the phase transition from C to G for OO and concomitantly from G to C for SO, the latter of which is coupled with the metamagnetic transition of the Dy 4f moments. The mechanism of this novel magnetic-field-induced orbital switching is discussed.

Characterization of spectroscopic photoemission and low energy electron microscope using multipolarized soft x rays at BL17SU/SPring-8

Spectroscopic photoemission and low energy electron microscope (SPELEEM) improved its performance after installation at BL17SU/SPring-8, where a multipolarization-mode undulator is employed to produce circularly and linearly polarized soft x rays. This undulator enables us to study the domain structures of ferromagnetic and antiferromagnetic materials by x-ray magnetic circular dichroism and x-ray magnetic linear dichroism. SPELEEM is used to study light elements (C, N, and O), 3d transition-metal elements and 4f rare earth elements, utilizing a wide range of photon energies. The two cylindrical mirrors adopted in front of SPELEEM ensure an illumination area of 14 x 14 microm(2) on the samples. The lateral resolution of a secondary electron photoemission electron microscope image is estimated to be better than 85 nm, whereas the energy resolution of the instrument is better than 0.4 eV.

A novel immunomodulator KRP-203 combined with cyclosporine prolonged graft survival and abrogated transplant vasculopathy in rat heart allografts

To find more effective and less toxic immunosuppressive strategies in long-term treatment for organ transplantation patients, we examined the effects on rat heart allograft survival of a novel sphigosine-1-phosphate receptor agonist, KRP-203, combined with a subtherapeutic dose of cyclosporine (CsA). Rat heart transplantation was performed across a major histocompatibility complex-incompatible (DA to LEW) rat combination. KRP-203 alone showed little or no effect on heart allograft survival. In contrast, KRP-203 combined with a subtherapeutic dose of CsA led to prolonged allograft survival. Histologic analyses showed that the combination completely suppressed acute rejection, as characterized by allograft vasculopathy, mononuclear cell infiltration, and myocardial necrosis in the heart allografts. RT-PCR analysis showed that the allografts treated with CsA or KRP-203 alone showed no suppression of IL-10, IFN-gamma, and TNF-alpha mRNA expression, but when combined with a subtherapeutic dose of CsA it completely suppressed their mRNA expressions. Furthermore, the combination treatment reduced donor-specific antibody production. KRP-203 combined with a subtherapeutic dose of CsA synergistically prolonged rat heart allograft survival. The combination of CsA with KRP-203 may provide an option to prevent allograft rejection and reduce adverse effects.

Essential role of Stat5 for IL-5-dependent IgH switch recombination in mouse B cells

IL-5 stimulation of CD38-activated murine splenic B cells induces mu-gamma1 CSR at the DNA level leading to a high level of IgG1 production. Further addition of IL-4 in the system enhances IL-5-dependent mu-gamma1 CSR. Although some of the postreceptor signaling events initiated by IL-5 in activated B cells have been characterized, the involvement of Stat in IL-5 signaling has not been thoroughly evaluated. In this study, we examined the activation of Stat5 and activation-induced cytidine deaminase (AID) in CD38-activated murine splenic B cells by IL-5. The role of Stat5a and Stat5b in IL-5-induced mu-gamma1 CSR and also IgG1 and IgM production was documented, as IL-5 does not act on CD38-stimulated splenic B cells from Stat5a(-/-) and Stat5b(-/-) mice. Expression levels of CD38-induced germline gamma1 transcripts and AID in Stat5a(-/-) and Stat5b(-/-) B cells upon IL-5 stimulation were comparable to those of wild-type B cells. The impaired mu-gamma1 CSR by Stat5b(-/-) B cells, but not by Stat5a(-/-) B cells, was rescued in part by IL-4, as the addition of IL-4 to the culture of CD38- and IL-5-stimulated B cells induced mu-gamma1 CSR leading to IgG1 production. Analysis of cell division cycle number of wild-type B cells revealed that mu-gamma1 CSR was observed after five or six cell divisions. Stat5a(-/-) and Stat5b(-/-) B cells showed similar cell division cycles, but they did not undergo mu-gamma1 CSR. Our data support the notion that both Stat5a and Stat5b are essential for IL-5-dependent mu;-gamma1 CSR and Ig secretion; however, their major target may not be AID. Stat5a and Stat5b are not redundant, but rather are at least partially distinctive in their function.

A survey of filling methods, intracanal medications, and instrument breakage

The present survey was conducted to obtain answers to some basic questions regarding the use of intracanal medications, root canal filling methods, and the intracanal breakage of instruments. A letter was sent to 300 endodontists listed in the 1995-1996 membership roster of the American Association of Endodontists. Eighty-five replies were received. Calcium hydroxide as an intracanal medication was used by 91.7% of the responding endodontists. With regard to the root canal filling technique, 52.9% used the lateral condensation method. When intracanal breakage occurred, 95.3% of the respondents informed the patient. The results of this survey provide useful information for the education of undergraduate dental students.

IgG1 production by sIgD+ splenic B cells and peritoneal B-1 cells in response to IL-5 and CD38 ligation

CD38 ligation on mouse B cells by CS/2, an anti-mouse CD38 mAb, induces proliferation, IL-5 receptor alpha chain expression and tyrosine phosphorylation of Bruton's tyrosine kinase. Furthermore, stimulation of splenic B cells with IL-5 together with CS/2 induces Blimp-1 expression and differentiation into Ig-producing cells. Here we examined the role of IL-5 in IgG1 and IgA production by B cells isolated from the spleen and peritoneal cavity. CD38 recognized by CS/2 was expressed in the follicular mantle B cells surrounding the germinal center, sIgD+ splenic B cells and peritoneal B cells. IL-5 induced IgG1 production in splenic sIgD+ B cells stimulated with CS/2, while it was ineffective to induce IgA production. Among the various cytokines tested, only IL-5 had a synergistic effect on IgG1 production with CS/2. IL-5 could induce the generation of S micro-Sgamma1 reciprocal recombination DNA products in CS/2-stimulated B cells. IL-4 was ineffective to induce either micro-gamma1 switch recombination or IgG1 secretion with CS/2, demonstrating that IL-5 promotes both micro-gamma1 switch recombination and IgG1 secretion in an IL-4-independent manner. The peritoneal B-2 cells exhibited both IgG1 and IgA production in response to IL-5 plus CS/2, while B-1 cells produced IgG1. These results imply that the pattern of differentiation to Ig-producing cells seen with peritoneal B cells is not identical to the pattern seen with splenic B cells and that peritoneal B-2 cells contain precursors of IgA-producing cells responding to IL-5 plus CS/2.

Inhibitory activities of gatifloxacin (AM-1155), a newly developed fluoroquinolone, against bacterial and mammalian type II topoisomerases

We determined the inhibitory activities of gatifloxacin against Staphylococcus aureus topoisomerase IV, Escherichia coli DNA gyrase, and HeLa cell topoisomerase II and compared them with those of several quinolones. The inhibitory activities of quinolones against these type II topoisomerases significantly correlated with their antibacterial activities or cytotoxicities (correlation coefficient [r] = 0.926 for S. aureus, r = 0.972 for E. coli, and r = 0.648 for HeLa cells). Gatifloxacin possessed potent inhibitory activities against bacterial type II topoisomerases (50% inhibitory concentration [IC50] = 13.8 microg/ml for S. aureus topoisomerase IV; IC50 = 0.109 microg/ml for E. coli DNA gyrase) but the lowest activity against HeLa cell topoisomerase II (IC50 = 265 microg/ml) among the quinolones tested. There was also a significant correlation between the inhibitory activities of quinolones against S. aureus topoisomerase IV and those against E. coli DNA gyrase (r = 0.969). However, the inhibitory activity against HeLa cell topoisomerase II did not correlate with that against either bacterial enzyme. The IC50 of gatifloxacin for HeLa cell topoisomerase II was 19 and was more than 2,400 times higher than that for S. aureus topoisomerase IV and that for E. coli DNA gyrase. These ratios were higher than those for other quinolones, indicating that gatifloxacin possesses a higher selectivity for bacterial type II topoisomerases.

Mediastinal lipoma: report of a case

We experienced a case of mediastinal lipoma, which is considered to be relatively rare disease. A 3-year-old girl was referred to Gifu University hospital because of fever and an abnormal shadow on her chest X-ray. The chest X-ray clearly showed a well-delineated tumor shadow which seemed to oppress the diaphragm and the right atrium in the right lower lung area. A computed tomogram (CT) of the chest showed a homogeneous mass localized on the right diaphragm and adjoining the right anterior chest wall and heart. The mass showed a fat density measuring about -100 HU. Magnetic resonance imaging (MRI) showed a high-intensity mass which was almost the same level as the subcutaneous fat on both the T1-weighted and T2-weighted images. Thoracotomy was performed and a fatty tumor was found. It arose from the right side of the pericardium and adjoined the diaphragm, the anterior chest wall, and the thymus. There was no adhesion between the tumor and the surrounding organs. It was resected easily and its contents were yellowish and homogeneous. The patient made an uneventful recovery and was discharged 10 days after the operation. Light microscopy showed a lipoma consisting of mature adipose tissue and no malignancy was found.

A critical role of Lyn and Fyn for B cell responses to CD38 ligation and interleukin 5

CD38 ligation on mouse B cells by CS/2, an anti-mouse CD38 mAb, induced proliferation, interleukin 5 (IL-5) receptor alpha chain expression, and tyrosine phosphorylation of Bruton tyrosine kinase (Btk) from wild-type, but not from X chromosome-linked, immunodeficient mice. B cells from fyn-deficient (Fyn-/-) and lyn-deficient (Lyn-/-) mice showed an impaired response to mAb CS/2 for proliferation and IL-5 receptor alpha chain expression, and B cells from fyn/lyn double-deficient (Fyn/Lyn-/-) mice did not respond at all to mAb CS/2. The Btk activation by CD38 ligation was observed in B cells from Fyn-/- mice, and it was severely impaired in B cells from Lyn-/- and Fyn/Lyn-/- mice. CD38 expression on B cells from three mutant strains was comparable to that on control B cells. We infer from these results that both Fyn and Lyn are required and that their signals are synergistic for B cell triggering after CD38 ligation. Lyn is upstream of Btk activation in the CD38 signaling. Stimulation of B cells with IL-5 together with CD38 ligation induces not only IgM but also IgG1 secretion. Analysis of the synergistic effects of IL-5 and CD38 ligation on IgG1 secretion revealed the impaired IgG1 secretion of B cells from Lyn-/- and Fyn/Lyn-/- mice. These data imply that Lyn is involved in B cell triggering by CD38 ligation plus IL-5 for isotype switching.

Structure and phase behaviour of dimyristoylphosphatidic acid/poly(L-lysine) systems

Differential scanning calorimetry (DSC) and X-ray diffraction studies on (DMPA)/poly(L-lysine) systems are reported. DSC studies revealed that addition of poly(L-lysine) to DMPA bilayers raises the gel to liquid-crystalline phase transition of the systems, and that this effect depends on the molecular weight of the poly(L-lysine). Small-angle X-ray diffraction measurements showed that, in the liquid-crystalline phase, the lamellar spacing of a DMPA/short-poly(L-lysine) (approximately 4000 mol. wt.) system is shorter than that of a DMPA/long-poly(L-lysine) (approximately 22000 mol. wt.). In this connection wide-angle X-ray diffraction measurements indicate that the long-poly(L-lysine) adopts a beta-sheet conformation on the DMPA bilayers in both the gel and the liquid-crystalline phases, but the short-poly(L-lysine) adopts this conformation only on gel phase DMPA bilayers. We found that the spacings of the hydrocarbon chain packing in a DMPA bilayer in the gel phase increases with temperature, while the spacing between neighbouring polypeptide chains in long-poly(L-lysine) in the beta-sheet conformation remains almost constant. These observations indicate that the positively charged lysine residues are structurally independent of the negatively charged head groups of the phospholipid. On the basis of the present results we propose a model to explain the elementary behaviour of extrinsic membrane proteins in biomembranes.

CD38 ligation induces tyrosine phosphorylation of Bruton tyrosine kinase and enhanced expression of interleukin 5-receptor alpha chain: synergistic effects with interleukin 5

Mouse CD38 has been implicated in the regulation of both B-cell proliferation and protection of B cells from irradiation-induced apoptosis. CD38 ligation on B cells by CS/2, an anti-mouse CD38 monoclonal antibody, induced proliferation, IgM secretion, and tyrosine phosphorylation of Bruton tyrosine kinase in B cells from wild-type mice. B cells from X chromosome-linked immunodeficient mice did not respond at all to anti-CD38 antibody, although CD38 expression on these B cells was comparable to that on wild-type B cells. We infer from these results that Bruton tyrosine kinase activation is involved in B-cell triggering after cross-linkage of CD38. Analysis of the synergistic effects of various cytokines with CD38 ligation on B-cell activation revealed that interleukin 5 (IL-5) showed the most potent effect on B-cell proliferation, Blimp1 gene expression, and IgM production. These synergistic effects were not seen with B cells from X chromosome-linked immunodeficient mice. Flow cytometry analysis revealed that CD38 ligation increased surface expression of the IL-5-receptor alpha chain on B cells. These data indicate that CD38 ligation increases IL-5 receptor alpha expression and synergizes with IL-5 to enhance Blimp1 expression and IgM synthesis.

Structural and thermotropic properties of calcium-dimyristoylphosphatidic acid complexes at acidic and neutral pH conditions

Two kinds of calcium-dimyristoylphosphatidic acid (DMPA) complexes at acidic and neutral pH conditions were prepared in the following ways. The complex at pH 4 was obtained by adding Ca2+ to DMPA dispersion in pure water. On the other hand, the complex at pH 7.4 was obtained by adding Ca2+ to DMPA dispersion in the presence of NaOH. The stoichiometries of Ca2+ ion to DMPA molecule are 0.5-0.67 and approximately 1 for the complexes at pH 4 and 7.4, respectively. Static x-ray diffraction shows that the hydrocarbon chains of the Ca(2+)-DMPA complex at pH 4 at 20 degrees C are more tightly packed than those of the complex at pH 7.4 at 20 degrees C. Furthermore, the complex at pH 4 at 20 degrees C gives rise to several reflections that might be related to the ordered arrangement of the Ca2+ ions. These results indicate that the structure of the complex at pH 4 is crystalline-like. In the differential scanning calorimetry (DSC) thermogram, the complex at pH 7.4 undergoes no phase transition in a temperature range between 30 and 80 degrees C. On the other hand, in the DSC thermogram for the complex at pH 4, a peak appears at 65.8 degrees C in the first heating scan. In the successive second heating scan, a transition peak appears at 63.5 degrees C. In connection with the DSC results, the structural changes associated with these phase transitions were studied with temperature-scan x-ray diffraction. In the first heating scan, although a peak appears at 65.80C in the DSC thermogram, the hydrocarbon chain packing gradually converts from an orthorhombic lattice to a hexagonal lattice near 52 degree C, and successively the chain melting phase transition occurs near 670C. In the second heating scan, the hydrocarbon chains are packed in a hexagonal lattice over the whole temperature range and the chain melting phase transition occurs near 63.5 degree C. Therefore,the Ca2+-DMPA complex at pH 4 has a metastable state. The metastable state transforms to a stable state by maintaining the complex at pH 4 for about 90 h at 200C.

[The genetic application for Japanese patients with coronary artery diseases using restriction fragment length polymorphisms (RFLPs) of apolipoprotein gene]

We applied restriction fragment length polymorphisms (RFLPs) for apolipoprotein (apoAI, apoCIII, apoAIV, apoCI, and apoB) genes to analyze differences between Japanese and Caucasian in allele frequencies as well as those between normal Japanese subjects and patients with coronary artery disease confirmed with coronary arteriography. Although the allelic fragment sizes in the two racial groups showed complete correspondence, the allelic frequencies of these markers detected by the combination of probes and restriction enzymes showed 60% difference in Japanese and Caucasian. There was a significant (p < 0.01) difference between the normal subjects (with arteriographically-confirmed absence of stenosis in all coronary branches) and those with severe coronary artery disease (50 to 100% stenosis in at least one branch) in plasma levels of apoAI, apoB, total cholesterol, HDL-cholesterol, and LDL-cholesterol. RFLP analysis for 13 markers, however, revealed no significant difference between these groups when analyzed in subjects of all ages (range, 12 to 82 years; N = 306). However, when analysis was restricted to data for 12-to 50-year-olds, a significant (p < 0.02) difference between the normal control group and the severe coronary artery disease group in 3' apoB probe and EcoRI enzyme test results. An acquired and environmental factors were assumed to be involved in this disease because the correlation between allelic frequencies and coronary artery disease status showed dilution when the subject age distribution included older subjects.

In vitro and in vivo antibacterial activities of AM-1155, a new 6-fluoro-8-methoxy quinolone

AM-1155 is a new quinolone with a wide spectrum of antibacterial activity against various bacteria including anaerobes and Mycoplasma pneumoniae. AM-1155 was 2- to 16-fold more active than ciprofloxacin and ofloxacin against Staphylococcus aureus including methicillin-resistant strains, Staphylococcus epidermidis, Streptococcus pneumoniae, and Enterococcus faecalis; its MICs for 90% of strains tested were 0.10 to 0.78 micrograms/ml. The activity of AM-1155 was comparable to that of ciprofloxacin against members of the family Enterobacteriaceae, Branhamella catarrhalis, Haemophilus influenzae, and Neisseria gonorrhoeae, but was fourfold less than that of ciprofloxacin against Pseudomonas aeruginosa. Against Xanthomonas maltophilia, Acinetobacter calcoaceticus, and Campylobacter jejuni, AM-1155 was two- to fourfold more active than ciprofloxacin. At a concentration of 1.56 micrograms/ml, AM-1155 inhibited 90% of Bacteroides fragilis strains tested; its activity was 8- to 10-fold higher than those of ofloxacin and ciprofloxacin. Development of resistance to AM-1155 in S. aureus and S. epidermidis occurred at a lower frequency than did that to ciprofloxacin after eight transfers in the presence of drug. In the oral treatment of mouse systemic infections, AM-1155 was four- to eightfold more effective than ciprofloxacin against gram-positive cocci and was as active as ciprofloxacin against gram-negative rods. The efficacy of an oral or a subcutaneous dose of AM-1155 was two- to fivefold greater than that of ofloxacin. Against experimental pneumonia with Klebsiella pneumoniae and P. aeruginosa, AM-1155 was two- to fourfold more active than ciprofloxacin and ofloxacin. AM-1155 also had good efficacy against mouse ascending urinary tract infections with Escherichia coli and P. aeruginosa. These results suggest that AM-1155 may be a potent antibacterial agent applicable to various infections.

An immunoserological study of patients with vibration syndrome

In a study undertaken to investigate the relationship between vibration syndrome and collagen disease, 90 Japanese patients with vibration syndrome (all men aged 41-86 years) were examined immunologic abnormalities, mainly by a set of immunoserology tests. Of these 90 patients, 25 had examinations at yearly intervals for 3 consecutive years, while the other 65 underwent examinations once. The results indicate that, of all the patients studied, 10 (11.1%) gave a positive RA test, 6 (6.7%) had leukopenia, 5 (5.6%) had hypergammaglobulinemia, and 15 (16.7%) had hypocomplementemia (CH50). Worthy of particular note are the 21 patients (23.3%) who were positive for nuclear-specific antibodies (1: greater than or equal to 40) (using Hep-2 cells as the nuclear substrate), with some of them suspected of having Sjögren's syndrome, progressive systemic sclerosis, or systemic lupus erythematosus. During a 3-year follow-up period, 10 (40%) of 25 patients exhibited rising titers of nuclear-specific antibodies with conversion to seropositivity for these antibodies. The facts that the positivity rate for nuclear-specific antibodies was significantly higher in these patients with vibration syndrome (23.3%) than in healthy adult men over 40 years of age (1.8%) (P less than 0.05) and that a progressive elevation of nuclear-specific antibody titer was noted in a high percentage of the patients were suggestive of some causal relationship between the appearance of nuclear-specific antibodies and the use of vibrating tools.

Effectiveness of house dust-mite allergen avoidance through clean room therapy in patients with atopic dermatitis

We have investigated the effectiveness of house dust-mite (HDM) allergen avoidance through clean room (CR) therapy in patients with atopic dermatitis (AD) having high HDM-specific IgE RAST levels. All patients (N = 30) demonstrated marked improvement in symptom, a long-term remission (mean, 8.4 months), and significant decreases in eosinophil count (p less than 0.01), basophil count (p less than 0.05), serum lactate dehydrogenase activity (p less than 0.01), and HDM-specific IgG levels (p less than 0.05). By contrast, the patients with AD (N = 11), who scored 0 on HDM allergen-specific IgE RAST score underwent "CR" therapy, and the patients with AD (N = 10) having high HDM-specific IgE RAST levels were hospitalized in a common sickroom (nonclean room). All the patients (N = 21) exhibited slight improvement in symptoms and a significant decrease in serum lactate dehydrogenase activity. The period of recurrence after the therapy was brief. The results of measurement of airborne house-dust particles indicated that our "CR" fell within class 10,000. Therefore, it is very likely that the mechanism at work in the CR therapeutic approach is its ability to eliminate fecal pellets of the HDM.

Functional analysis of HLA-DR-expressing keratinocytes from tuberculin reactive skin

We examined the functional roles of HLA-DR+ keratinocytes which were induced in vivo from tuberculin reactive skin. At 4 days after intradermal PPD injection, about 80% of keratinocytes obtained from the tuberculin reactive area expressed DR antigens. In 14 of 18 individuals examined, PPD-pulsed DR+ keratinocyte fraction induced autologous T-cell proliferation. The proliferative response was PPD-dependent, antigen specific; it depended upon DR expression by the keratinocyte fraction, because it did not occur in the presence of the PPD-nonpulsed DR+ keratinocyte fraction and was completely blocked by mouse monoclonal antibody to HLA-DR. However, the antigen-presenting capacity of the DR+ keratinocyte fraction appeared to be less than that of monocytes or the DR+ epidermal cell fraction. The DR+ keratinocyte fraction was also able to stimulate allogeneic T-cell DNA synthesis, but the DR- keratinocyte fraction could not. The possible influences of contaminant Langerhans cells and mononuclear cells in the DR+ keratinocyte fraction were considered to be unlikely. These results suggest that DR+ keratinocytes, which are induced in vivo, can both present the antigen to autologous T cells and stimulate allogeneic T cells.

Cytotoxic effect of 1-methyl-4-phenylpyridinium ion on human melanoma cell lines, HMV-II and SK-MEL-44, is dependent on the melanin contents and caused by inhibition of mitochondrial electron transport

MPP+, an oxidative metabolite of a neurotoxin, MPTP, was found to be cytotoxic to human melanoma cell lines, HMV-II and SK-MEL-44. After 3 days of culture in the presence of MPP+, a larger amount of MPP+ was accumulated in HMV-II cells than in SK-MEL-44 cells, which correlated well with the melanin contents; HMV-II cells contain larger amounts of melanin than SK-MEL-44 cells. After 6 days of culture in the presence of MPP+, the cytotoxicity of MPP+ on these cell types was evaluated by counting cell numbers with the dye exclusion test and double-layer soft agar clonogenic assay. It was found that exposure to MPP+ reduced the survival of HMV-II cells more significantly than that of SK-MEL-44 cells. In HMV-II cells, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay was used to elucidate the mechanism of MPP+ lethality. The formazan formation was reduced markedly by the presence of MPP+ at concentrations much lower than those required for cell death. These results suggest that cytotoxicity of MPP+ may be ascribed to its accumulation due to high affinity for melanin, and to inhibition of the enzymes utilizing ubiquinone in the mitochondrial respiratory chain.

[Porphyria cutanea tarda in a chronic hemodialysis patient]

After 6 months on hemodialysis, a 58-year-old male patient with diabetes developed photosensitive bullous dermatosis on his hands and face. There was no evidence of liver diseases although the patient had a history of excessive alcohol consumption. He was suspected to have iron overload in the liver. Analysis of porphyrins in plasma, hemofiltrate, urine and feces by high performance liquid chromatography revealed significantly high levels in these samples with a porphyrin profiles which is consistent with porphyria cutanea tarda. The fluorometric assays of plasma also disclosed an elevated plasma porphyrin level. And it seemed that there were correlation between the fluctuation of vesicle formation, serum ferritin level and plasma porphyrin level. Small volume plasma exchange temporarily reduced the plasma porphyrin level and prevented vesicle formation.

[The roles of proteinase production and germ tube formation in the invasion of Candida albicans into newborn mouse skin]

The pathogenic factors of Candida albicans involved in invasion of the skin were studied. Strains of C. albicans differing in their abilities to secrete proteinase in vitro and to produce germ tube were inoculated onto the skin surface of newborn mice, and the invasion of the yeast cells into the horny layer was examined by histological techniques. The strains capable of producing germ tubes could penetrate into the skin, but those incapable of germ tube formation could not. The penetration of the yeast cells into the skin was independent of the ability to secrete proteinase, but, once penetrated, Candida cells from the proteinase-producing strains proliferated more profusely than those of proteinase-deficient ones. The results suggested that the invasion of C. albicans into the skin consisted of two processes; penetration and proliferation of the yeast cells in the tissue. The former might depend on the ability of germ tube formation and the latter on the secretion of proteinase.

[Neoplastic angioendotheliosis: a case of T cell lymphoma positive for S-100 protein]

A 63-year-old woman presented with painless, firm, subcutaneous nodules on her legs and trunk. The lesions were annular or serpiginous and their surface was livid-red to pale-red. Superficial lymph nodes were not palpable. Upper gastrointestinal series, barium enema, Ga scintigraphy, and CT findings were negative. Histological examination revealed deep dermal vessels occupied by neoplastic cells and fibrin thrombi. We diagnosed her as having neoplastic angioendotheliosis. Electron microscopically, tumor cells lacked Weibel-Palade bodies. Immunohistochemically, the tumor cells were positive for leukocyte common antigen, T11, MT-1, HLA-DR and S-100 protein. They were negative for Factor VIII-related antigen, epithelial membrane antigen, carcinoembryonic antigen, B-1, and B-2. Immunoelectron microscopic study showed that their nuclei, cytoplasma, and cell membranes were positive for S-100 protein. Based on these findings, we diagnosed her as having T cell lymphoma. The patient rejected chemotherapy and was discharged. Three months after discharge, right hemiplegia developed. Brain CT scan revealed enhanced masses in the left frontal, temporal, and occipital lobes. Craniotomy showed only gliosis and hemorrhage. She died of cerebral bleeding three months after craniotomy.

[Two cases of scleroderma associated with vibration syndrome]

Case 1, a 49-year-old male who had been engaged in repair and reclamation of automobile tires, developed symptoms of vibration syndrome (Raynaud's phenomenon, numbness of both hands, tinnitus and impaired hearing) after some 30 years' use of a grinder and impact wrench. Two years thereafter, multiple sclerodermic lesions appeared over the trunk, upper extremities, and thighs; these disappeared about 2 years later. Histologically, hyperplasia and nodular swelling of collagen bundles were present in the dermis. An immunological study showed the serum to be positive for anti-centromere antibody, but no visceral lesions were demonstrable. This case corresponded to generalized morphea. Case 2, a 53-year-old male, developed symptoms of vibration syndrome (Raynaud's phenomenon, numbness of both hands, impaired hearing and arthralgia) after 25 years' use of a jack hammer in a quarry. Thereafter, sclerodermic changes of the forearms, lower legs, face and abdomen occurred with an associated sclerodactyly. Histological examination of involved skin revealed diffuse hyperplasia and homogenization of collagen bundles throughout the entire thickness of the dermis. These findings, together with serum positivity for anti-RNP antibody and dilation of the lower portion of the esophagus, led us to a diagnosis of progressive systemic sclerosis. We inferred that the vibration syndrome in the present cases might be related etiologically to these forms of scleroderma.

Effects of fleroxacin on HeLa cell functions and topoisomerase II

The effects of fleroxacin and other new 4-quinolones on cellular functions and topoisomerase II of HeLa cells were investigated. The potency of cytotoxicity increased in the order fleroxacin less than nalidixic acid less than ofloxacin less than norfloxacin less than ciprofloxacin. The cytotoxicity was well correlated with inhibitory effects of 4-quinolones on topoisomerase II. However, the cytotoxicity did not correlate with antibacterial activity, and cytotoxicity was observed only at greater than 100-fold higher concentrations than the minimum inhibitory concentrations of new 4-quinolones for Enterobacteriaceae. Judging from the serum levels attainable after oral administration, new 4-quinolones, especially fleroxacin, will have little effect on topoisomerase in eukaryotic cells.

Effects of diltiazem hydrochloride on the reduction of blood pressure, and cardiac and renal functions in essential hypertensive patients with renal dysfunction

Diltiazem hydrochloride was administered at a dose of 180 mg/day for 12 weeks to 10 essential hypertensive patients with slightly or moderately decreased renal plasma flow (RPF) in order to study its antihypertensive effect as well as the effects on cardiac and renal functions. The administration of diltiazem hydrochloride produced significant decreases in systolic pressure, diastolic pressure, and mean blood pressure. Right and left ventricular ejection fractions, max. dv/dt, and min. dv/dt assessed by cardiac pool scintigraphy were slightly increased, but these changes were not statistically significant. The glomerular filtration rate (GFR) and RPF were slightly increased, while renovascular resistance (RVR) was significantly reduced. No consistent tendency was observed in changes in plasma renin activity (PRA) and plasma aldosterone level. From these results, it was suggested that diltiazem hydrochloride is a potent antihypertensive drug which has no adverse effects on cardiac and renal functions in the treatment of essential hypertensive patients with slightly or moderately decreased RPF.

Angiographic difference in coronary artery of man, dog, pig, and monkey

Comparative morphological studies on the coronary arteries of the left ventricular free wall were carried out on human, dog, pig, and monkey hearts by using postmortem coronary arteriography, soft X-ray photograms, and the clearing method. The results showed that the types of coronary arteries (types I, II, and III) and connecting portion of anastomotic vessels in the pig and monkey hearts closely resembled those in man. Whereas the dog hearts showed the following characteristics: numerous Type III vessels and anastomoses in the epicardial layer, the existence of only the left predominant type of coronary artery, and the supply of blood to the papillary muscles of the left ventricle mostly through a single branch of the coronary artery. Therefore, it is necessary to take into consideration the basic difference in the structure of the coronary arteries of human and dog hearts, when dogs are used experimentally for research of human ischemic heart disease. The fact that only the papillary muscles of the human heart-compared to animal hearts-are supplied blood from two sources may be advantageous to rescue the papillary muscles from ischemic necrosis.

Livedoid vasculitis and central nervous system involvement in systemic lupus erythematosus

Of 66 patients with systemic lupus erythematosus (SLE), 11 (16.7%) had livedoid vasculitis. The sites of predilection included the elbows, knees, fingers, soles, and back, which are not those of common livedoid vasculitis. Livedoid vasculitis developed in ten (90.9%) of the 11 patients with SLE who eventually developed central nervous system (CNS) lupus. In contrast, such preceding livedoid vasculitis occurred in only three (11.5%) of the 26 patients with severe nephrotic lupus nephritis. Livedoid vasculitis did not occur in any patient with neither CNS lupus nor severe lupus nephritis. These results indicate that livedoid vasculitis in SLE is a very important cutaneous manifestation that may possibly be prodromal to CNS lupus.