High spatial resolution surface plasmon resonance imaging using a plasmonic chip

The surface plasmon resonance (SPR) technique has been widely applied to biosensing technologies for the rapid quantification of biomolecules without enzyme and fluorescent labeling. However, the conventional prism-coupling SPR method generally has a detection area of a few mm2, and the large contribution of the background signal forms a barrier to highly sensitive detection. Based on a highly spatially resolved SPR method, the present study constructed a scanning GC-SPR imaging instrument using an objective lens with a high numerical aperture and a plasmonic chip that could be used for grating-coupled SPR. Focusing light on the diffraction limit can suppress background signals and improve detection sensitivity. SPR imaging can also be performed by scanning a focal spot. Using this method, the refractive index of a mixture of water and dimethyl sulfoxide was measured with a detection accuracy of 2.43 × 10-3 RIU. Polydopamine films prepared with a thickness of <5 nm were also measured, and each film thickness was evaluated with high sensitivity from the effective refractive index detected in a small area of <1 µm2.

Label-Free Evaluation of Maturation and Hepatotoxicity of Human iPSC-Derived Hepatocytes Using Hyperspectral Raman Imaging

To promote the clinical application of human induced pluripotent stem cell (hiPSC)-derived hepatocytes, a method capable of monitoring regenerative processes and assessing differentiation efficiency without harming or modifying these cells is important. Raman microscopy provides a powerful tool for this as it enables label-free identification of intracellular biomolecules in live samples. Here, we used label-free Raman microscopy to assess hiPSC differentiation into hepatocyte lineage based on the intracellular chemical content. We contrasted these data with similar phenotypes from the HepaRG and from commercially available hiPSC-derived hepatocytes (iCell hepatocytes). We detected hepatic cytochromes, lipids, and glycogen in hiPSC-derived hepatocyte-like cells (HLCs) but not biliary-like cells (BLCs), indicating intrinsic differences in biomolecular content between these phenotypes. The data show significant glycogen and lipid accumulation as early as the definitive endoderm transition. Additionally, we explored the use of Raman imaging as a hepatotoxicity assay for the HepaRG and iCell hepatocytes, with data displaying a dose-dependent reduction of glycogen accumulation in response to acetaminophen. These findings show that the nondestructive and high-content nature of Raman imaging provides a promising tool for both quality control of hiPSC-derived hepatocytes and hepatotoxicity screening.

Label-Free Monitoring of Drug-Induced Cytotoxicity and Its Molecular Fingerprint by Live-Cell Raman and Autofluorescence Imaging

Simultaneous observation of drug distribution at the effector site and subsequent cell response are essential in the drug development process. However, few studies have visualized the drug itself and biomolecular interactions in living cells. Here, we used label-free Raman microscopy to investigate drug-induced cytotoxicity and visualize drug uptake and subcellular localization by its specific molecular fingerprint. A redox-sensitive Raman microscope detected the decrease of reduced cytochrome c (cyt c) after Actinomycin D (ActD) treatment in a time-dependent and dose-dependent format. Immunofluorescence staining of cyt c suggested that the release of cyt c was not the major cause. Combining Raman microscopy with conventional biological methods, we reported that the oxidization of cyt c is an early cytotoxicity marker prior to the release of cyt c. Moreover, as the spectral properties of ActD are sensitive to the surrounding environment, subcellular localization of ActD was visualized sensitively by the weak autofluorescence, and the intercalation of ActD into DNA was detected by shifted Raman peaks, allowing for parallel observation of drug uptake and the mechanism of action. In this research, we achieved simultaneous observation of cytotoxicity and cellular drug uptake by Raman microscopy, which could facilitate a precise understanding of pharmacological effects and predict potential drug toxicity in the future.

Detection of Glutamate Encapsulated in Liposomes by Optical Trapping Raman Spectroscopy

The transmission of neuronal information is propagated through synapses by neurotransmitters released from presynapses to postsynapses. Neurotransmitters released from the presynaptic vesicles activate receptors on the postsynaptic membrane. Glutamate acts as a major excitatory neurotransmitter for synaptic vesicles in the central nervous system. Determining the concentration of glutamate in single synaptic vesicles is essential for understanding the mechanisms of neuronal activation by glutamate in normal brain functions as well as in neurological diseases. However, it is difficult to detect and quantitatively measure the concentration of glutamate in single synaptic vesicles owing to their small size, i.e., ∼40 nm. In this study, to quantitatively evaluate the concentrations of the contents in small membrane-bound vesicles, we developed an optical trapping Raman spectroscopic system that analyzes the Raman spectra of small objects captured using optical trapping. Using artificial liposomes encapsulating glutamate that mimic synaptic vesicles, we investigated whether spontaneous Raman scattered light of glutamate can be detected from vesicles trapped at the focus using optical forces. A 575 nm laser beam was used to simultaneously perform the optical trapping of liposomes and the detection of the spontaneous Raman scattered light. The intensity of Raman scattered light that corresponds to lipid bilayers increased with time. This observation suggested that the number of liposomes increased at the focal point. The number of glutamate molecules in the trapped liposomes was estimated from the calibration curve of the Raman spectra of glutamate solutions with known concentration. This method can be used to measure the number of glutamate molecules encapsulated in synaptic vesicles in situ.

Deuterated Glutamate-Mediated Neuronal Activity on Micro-Electrode Arrays

The excitatory synaptic transmission is mediated by glutamate in neuronal networks of the mammalian brain. In addition to the synaptic glutamate, extra-synaptic glutamate is known to modulate the neuronal activity. In neuronal networks, glutamate uptake is an important role of neurons and glial cells for lowering the concentration of extracellular glutamate and to avoid the excitotoxicity by glutamate. Monitoring the spatial distribution of intracellular glutamate is important to study the uptake of glutamate, but the approach has been hampered by the absence of appropriate glutamate analogs that report the localization of glutamate. Deuterium-labeled glutamate (GLU-D) is a promising tracer for monitoring the intracellular concentration of glutamate, but physiological properties of GLU-D have not been studied. Here we study the effects of extracellular GLU-D for the neuronal activity by using primary cultured rat hippocampal neurons that form neuronal networks on microelectrodes array. The frequency of firing in the spontaneous activity of neurons increased with the increasing concentration of extracellular GLU-D. The frequency of synchronized burst activity in neurons increased similarly as we observed in the spontaneous activity. These changes of the neuronal activity with extracellular GLU-D were suppressed by antagonists of glutamate receptors. These results suggest that GLU-D can be used as an analog of glutamate with equivalent effects for facilitating the neuronal activity. We anticipate GLU-D developing as a promising analog of glutamate for studying the dynamics of glutamate during neuronal activity.

High-resolution imaging in two-photon excitation microscopy using in situ estimations of the point spread function

We present a technique for improving the spatial resolution of two-photon excitation microscopy; our technique combines annular illumination with an in situ estimation of the point spread function (PSF) used for deconvolution. For the in situ estimation of the PSF, we developed a technique called autocorrelation scanning, in which a sample is imaged by the scanning of two excitation foci that are overlapped over various distances. The image series obtained with the variation of the distance between the two foci provides the autocorrelation function of the PSF, which can be used to estimate the PSF at specific positions within a sample. We proved the principle and the effectiveness of this technique through observations of a fluorescent biological sample, and we confirmed that the improvement in the spatial resolution was ~1.7 times that of typical two-photon excitation microscopy by observing a mouse brain phantom at a depth of 200 µm.

Cell structure imaging with bright and homogeneous nanometric light source

Label-free optical nano-imaging of dendritic structures and intracellular granules in biological cells is demonstrated using a bright and homogeneous nanometric light source. The optical nanometric light source is excited using a focused electron beam. A zinc oxide (ZnO) luminescent thin film was fabricated by atomic layer deposition (ALD) to produce the nanoscale light source. The ZnO film formed by ALD emitted the bright, homogeneous light, unlike that deposited by another method. The dendritic structures of label-free macrophage receptor with collagenous structure-expressing CHO cells were clearly visualized below the diffraction limit. The inner fiber structure was observed with 120 nm spatial resolution. Because the bright homogeneous emission from the ZnO film suppresses the background noise, the signal-to-noise ratio (SNR) for the imaging results was greater than 10. The ALD method helps achieve an electron beam excitation assisted microscope with high spatial resolution and high SNR.

Saturated two-photon excitation fluorescence microscopy with core-ring illumination

We demonstrated resolution improvement in two-photon excitation microscopy by combining saturated excitation (SAX) of fluorescence and pupil manipulation. We theoretically estimated the resolution improvement and the sidelobe effect in the point spread function with various pupil designs and found that the combination of SAX and core-ring illumination can effectively enhance the spatial resolution in 3D and suppress sidelobe artifacts. The experimental demonstration shows that the proposed technique is effective for observation with a depth of 100 μm in a tissue phantom and can be applied to 3D observations of tissue samples with higher spatial resolution than conventional two-photon excitation microscopy.

Carboxylic monolayer formation for observation of intracellular structures in HeLa cells with direct electron beam excitation-assisted fluorescence microscopy

Intracellular structures of HeLa cells are observed using a direct electron beam excitation-assisted fluorescence (D-EXA) microscope. In this microscope, a silicon nitride membrane is used as a culture plate, which typically has a low biocompatibility between the sample and the silicon nitride surface to prevent the HeLa cells from adhering strongly to the surface. In this work, the surface of silicon nitride is modified to allow strong cell attachment, which enables high-resolution observation of intracellular structures and an increased signal-to-noise ratio. In addition, the penetration depth of the electron beam is evaluated using Monte Carlo simulations. We can conclude from the results of the observations and simulations that the surface modification technique is promising for the observation of intracellular structures using the D-EXA microscope.

Fabrication of bright and thin Zn₂SiO₄ luminescent film for electron beam excitation-assisted optical microscope

We fabricated a bright and thin Zn₂SiO₄ luminescent film to serve as a nanometric light source for high-spatial-resolution optical microscopy based on electron beam excitation. The Zn₂SiO₄ luminescent thin film was fabricated by annealing a ZnO film on a Si₃N₄ substrate at 1000 °C in N₂. The annealed film emitted bright cathodoluminescence compared with the as-deposited film. The film is promising for nano-imaging with electron beam excitation-assisted optical microscopy. We evaluated the spatial resolution of a microscope developed using this Zn₂SiO₄ luminescent thin film. This is the first report of the investigation and application of ZnO/Si₃N₄ annealed at a high temperature (1000 °C). The fabricated Zn₂SiO₄ film is expected to enable high-frame-rate dynamic observation with ultra-high resolution using our electron beam excitation-assisted optical microscopy.

High-resolution, label-free imaging of living cells with direct electron-beam-excitation-assisted optical microscopy

High spatial resolution microscope is desired for deep understanding of cellular functions, in order to develop medical technologies. We demonstrate high-resolution imaging of un-labelled organelles in living cells, in which live cells on a 50 nm thick silicon nitride membrane are imaged by autofluorescence excited with a focused electron beam through the membrane. Electron beam excitation enables ultrahigh spatial resolution imaging of organelles, such as mitochondria, nuclei, and various granules. Since the autofluorescence spectra represent molecular species, this microscopy allows fast and detailed investigations of cellular status in living cells.

High resolution fluorescent bio-imaging with electron beam excitation

We have developed electron beam excitation assisted (EXA) optical microscope[1-3], and demonstrated its resolution higher than 50 nm. In the microscope, a light source in a few nanometers size is excited by focused electron beam in a luminescent film. The microscope makes it possible to observe dynamic behavior of living biological specimens in various surroundings, such as air or liquids. Scan speed of the nanometric light source is faster than that in conventional near-field scanning optical microscopes. The microscope enables to observe optical constants such as absorption, refractive index, polarization, and their dynamic behavior on a nanometric scale. The microscope opens new microscopy applications in nano-technology and nano-science.Figure 1(a) shows schematic diagram of the proposed EXA microscope. An electron beam is focused on a luminescent film. A specimen is put on the luminescent film directly. The inset in Fig. 1(a) shows magnified image of the luminescent film and the specimen. Nanometric light source is excited in the luminescent film by the focused electron beam. The nanometric light source illuminates the specimen, and the scattered or transmitted radiation is detected with a photomultiplier tube (PMT). The light source is scanned by scanning of the focused electron beam in order to construct on image. Figure 1(b) shows a luminescence image of the cells acquired with the EXA microscope, and Fig. 1(c) shows a phase contrast microscope image. Cells were observed in culture solution without any treatments, such as fixation and drying. The shape of each cell was clearly recognized and some bright spots were observed in cells. We believe that the bright spots indicated with arrows were auto-fluorescence of intracellular granules and light- grey regions were auto-fluorescence of cell membranes. It is clearly demonstrated that the EXA microscope is useful tool for observation of living biological cells in physiological conditions.jmicro;63/suppl_1/i16/DFU090F1F1DFU090F1Fig. 1.(a) Optical setup of EXA microscpe, and observation results of of living MARCO-expressing CHO cells with (b) EXA microscope and (c) phase contrast microscope. We proposed the EXA microscope as a technique with high spatial resolution beyond the diffraction limit of light. A spatial resolution greater than 100 nm was achieved for the EXA microscope and the dynamic behavior of moving nanoparticles in water was observed by time lapse imaging. We also demonstrated luminescence image of living cells in culture solution without any treatments.

Dynamic autofluorescence imaging of intracellular components inside living cells using direct electron beam excitation

We developed a high-resolution fluorescence microscope in which fluorescent materials are directly excited using a focused electron beam. Electron beam excitation enables detailed observations on the nanometer scale. Real-time live-cell observation is also possible using a thin film to separate the environment under study from the vacuum region required for electron beam propagation. In this study, we demonstrated observation of cellular components by autofluorescence excited with a focused electron beam and performed dynamic observations of intracellular granules. Since autofluorescence is associated with endogenous substances in cells, this microscope can also be used to investigate the intrinsic properties of organelles.

Multi-color imaging of fluorescent nanodiamonds in living HeLa cells using direct electron-beam excitation

Multi-color, high spatial resolution imaging of fluorescent nanodiamonds (FNDs) in living HeLa cells has been performed with a direct electron-beam excitation-assisted fluorescence (D-EXA) microscope. In this technique, fluorescent materials are directly excited with a focused electron beam and the resulting cathodoluminescence (CL) is detected with nanoscale resolution. Green- and red-light-emitting FNDs were employed for two-color imaging, which were observed simultaneously in the cells with high spatial resolution. This technique could be applied generally for multi-color immunostaining to reveal various cell functions.

Evaluation of the antigenic similarities of adult-worm extracts from threeGnathostomaspecies, using sera from Mexican and Japanese patients withGnathostomainfections

The antigenic similarities of adult-worm extracts of Gnathostoma spinigerum, G. hispidum and G. doloresi, all of which are important food-borne parasites causing larva migrans in humans, were evaluated. The 40 sera used came from gnathostomiasis cases in Mexico, where G. binucleatum is endemic, or in Japan, where G. doloresi predominates. When used as the fixed antigens in microplate-ELISA, the adult-worm extracts from the three different species of Gnathostoma were found to have equal binding capacity to the Gnathostoma-specific IgG antibodies in the sera of the Mexican and Japanese patients. The correlation coefficients for the optical densities seen in the ELISA, between any two of the three Gnathostoma extracts, were all >0.900. The dose-response curves produced when four sera were tested, in the microplate-ELISA, against the three different Gnathostoma extracts were nearly identical, indicating that the antigens in each of the extracts had similar avidity. Furthermore, the results of competitive-inhibition ELISA indicated that the antigenic specificities of the three extracts were almost identical. An antigen of 40 kDa, which SDS-PAGE and immunoblot analysis revealed to be present in all three extracts, was recognized by the sera from the gnathostomiasis cases. When the sera were investigated by dot-blot ELISA, they also gave similar results whichever extract was used as the antigen source. It appears that, in the serodiagnosis of gnathostomiasis by microplate- or dot-ELISA, each of the three adult-worm extracts would be equally useful, regardless of the causative species of Gnathostoma.

Dynamic and high-resolution live cell imaging by direct electron beam excitation

We propose a direct electron-beam excitation assisted optical microscope with a resolution of a few tens of nanometers and it can be applied for observation of dynamic movements of nanoparticles in liquid. The technique is also useful for live cell imaging under physiological conditions as well as observation of colloidal solution, microcrystal growth in solutions, etc. In the microscope, fluorescent materials are directly excited with a focused electron beam. The direct excitation with an electron beam yields high spatial resolution since the electron beam can be focused to a few tens of nanometers in the specimens. In order to demonstrate the potential of our proposed microscope, we observed the movements of fluorescent nanoparticles, which can be used for labelling specimens, in a water-based solution. We also demonstrated an observation result of living CHO cells.

Serodiagnostic reliability of single-step enriched low-molecular weight proteins of Taenia solium metacestode of American and Asian isolates

The low-molecular weight proteins (LMWPs) of Taenia solium metacestode (TsM) constituted pertinent serodiagnostic antigens for cysticercosis. We established a novel single-step purification of the LMWPs from TsM cyst fluid (CF). When the CF was precipitated with trichloroacetic acid/acetone mixture at the final concentrations of 5 and 50%, most LMWPs (ranging 7-38kDa) remained in the supernatant fraction. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblot analyses revealed that the LMWPs consisted mainly with the previously reported subunit proteins of the 120- and 150-kDa antigen complexes. Serum samples from neurocysticercosis (NC) and other helminthic infections, as well as those from healthy controls were tested by both immunoblotting and micro-ELISA. In 135 cases of active stage NC patients, 132 cases (97.7%) showed positive reactions. Serum samples from other helminthic diseases (n=125) and healthy controls (n=100) exhibited no positive reactions except for cystic echinococcosis, of which 12% (3/25 cases) exhibited low levels of cross-reactivity. The LMWPs from different geographical regions (Korea and Mexico) showed diagnostic sensitivity and specificity of 97.7% and 98.7% against active stage NC. Our single-step separation method for the LMWPs provided excellent performance with easy applicability and high reproducibility, which has a great benefit for preparation of potent antigen in endemic areas.

1,5-Anhydroglucitol attenuates cytokine release and protects mice with type 2 diabetes from inflammatory reactions

1,5-anhydroglucitol (1,5-AG) decreases in diabetic patients and is used as a marker of glycemic control. Type 2 diabetic patients are susceptibile to lipopolysaccharides (LPS), which stimulate macrophages to release large quantities of tumor necrosis factor (TNF)-alpha and interleukin (IL)-6. This study examines the effects of 1,5-AG on lung inflammation induced by LPS and consequent systemic inflammation to determine whether the decrease of 1,5-AG concentration induces susceptibility to LPS. Before the challenge with LPS (1 mg/kg in vivo and 500 ng/ml in vitro), we pretreated db/db mice and RAW264.7 cells with 1,5-AG at 38.5 mg/kg and 500 microg/ml, respectively. The levels of IL-6, TNF-alpha, macrophage chemoattractant protein (MCP)-1 and IL-1beta in the serum and in the cell supernatants were measured. We also measured macrophage recruitment and the expression of inducible nitric oxide synthase (iNOS) in pulmonary tissues. We found that 1,5-AG attenuated serum cytokine release and protected db/db mice from LPS-induced pulmonary inflammation. In addition, 1,5-AG suppressed cytokine release and iNOS expression by suppressing Akt/NF-kB activity in RAW264.7 cells. These results suggest that 1,5-AG may be a mediator in, as well as marker for diabetes, and 1,5-AG intake may confer tolerance to LPS in patients with type 2 diabetes.

First findings on the seroepidemiology of human paragonimosis at the anti-tuberculosis centre of Divo, Repubuc of Ivory Coast (West Africa)

An epidemiological study was carried out in 2004-2005 at the anti-tuberculosis centre of Divo (Ivory Coast) to collect sera from patients who consulted for tuberculosis suspicion and to estimate the seroprevalence of human paragonimosis in the context of a systematic screening. No Paragonimus egg was found in the stools and/or sputa of the 167 persons investigated. In contrast, 41 sera were ascertained with antibodies against Paragonimus africanus using ELISA testing. As the optical density (OD) values related to seropositive findings were found under 0.6 (the minimal OD to detect an active paragonimosis), the above antibody titres might originate from patients in chronic or in convalescent stages, or might result of cross reactions with trematodes. Concomitantly, dissection of local crabs (Callinectes marginatus) demonstrated the presence of Paragonimus metacercariae in six out of 34 examined. The parasite burdens in crabs ranged from two to 35 cysts with a mean diameter of 302 microm. In Ivory Coast, the locality of Divo must be considered an at-risk zone in reason of the presence of anti-Paragonimus antibodies in several human sera and the presence of infected crabs at the local market.

Suppressor of cytokine signalling 1 in lymphocytes regulates the development of intestinal inflammation in mice

BACKGROUND AND AIMS

Imbalance between pro- and anti-inflammatory cytokines produced by intestinal T cells induces inflammatory bowel diseases (IBD). However, the importance of regulation of cytokine signalling in IBD has not been fully clarified. We have demonstrated that suppressor of cytokine signalling 1 (SOCS1) is expressed in inflamed tissues in an experimental colitis model. In the present study, we investigated the role of SOCS1 in colitis models to clarify the mechanism of IBD development.

METHODS

Intestinal T cells in transgenic mice expressing high levels of SOCS1 in lymphocytes (SOCS1Tg mice) were characterised by flow cytometric analysis and cytokine production from intestinal T cells was determined by ELISA. 2,4,6-Trinitrobenzene sulphonic acid (TNBS) induced colitis was induced in SOCS1Tg mice and severity was compared with control littermates by measurement of survival rates. Intracellular signalling was assessed by western blotting analysis.

RESULTS

SOCS1Tg mice developed colitis spontaneously with age. Young SOCS1Tg mice less than 15 weeks of age, before the onset of colitis, were susceptible to TNBS induced colitis. Intestinal T cells of SOCS1Tg mice showed increased interferon gamma and tumour necrosis factor alpha production and decreased transforming growth factor beta production. Expression of cytotoxic T lymphocyte associated antigen 4 (CTLA-4), a negative regulator of T cell activation, in SOCS1Tg mice was severely impaired at the protein level although mRNA levels of CTLA-4 in SOCS1Tg mice were comparable with those in control mice.

CONCLUSIONS

Our data suggest that SOCS1 plays an important role in the regulation of colitis by controlling intestinal T cell activation mediated through CTLA-4 expression.

Bone marrow transplantation from unrelated donors for patients with adult T-cell leukaemia/lymphoma

Adult T-cell leukaemia/lymphoma (ATLL) is a highly aggressive haematological malignancy. More than 40 cases of ATLL treated by allogeneic bone marrow transplantation (BMT) from sibling donors have been reported, while there have been only a few cases of unrelated BMT for treatment of this disease. We began performing allogeneic BMT from unrelated donors in 1999 to improve the outcome of ATLL patients with no suitable sibling donors. Eight ATLL patients underwent unrelated BMT; five received the conventional conditioning regimen consisting of cyclophosphamide and total body irradiation, while three received a reduced-intensity preparative regimen. Two patients died due to encephalopathy of unknown aetiology on days 10 and 35, and one patient died due to progression of ATLL 25 months after BMT. Five patients are currently alive and disease-free at a median of 20 months after BMT. Proviral human T-lymphotropic virus type-I (HTLV-I) DNA load in peripheral blood mononuclear cells (PBMCs) was assessed in four cases before and after BMT. HTLV-I proviral DNA load was reduced significantly after transplantation. Unrelated BMT is feasible for treatment of ATLL. Further studies in a larger number of cases are required to determine the optimal conditioning regimen and stem cell source.

The first human case in Mexico of conjunctivitis caused by the avian parasite, Philophthalmus lacrimosus

Species of Philophthalmus parasitize primarily the eyes of wild and domestic birds. A variety of mammals, including humans, occasionally serve as the intermediate as well as the definitive hosts for this parasite, although human cases are extremely rare. Here, we report a case of human conjunctivitis caused by an infection with Philophthalmus sp. in Mexico. The patient was a 31-yr-old male who visited an ophthalmologist in Los Mochis, Sinaloa, Mexico, because of a foreign-body sensation in his left eye for 2 mo. A small live parasite was found in the connective tissue of the bulbar conjunctiva and was removed surgically under local anesthesia under ophthalmoscopic observation. The parasite was identified morphologically as Philophthalmus lacrimosus Braun, 1902. This is the first case of human philophthalmosis in Mexico and, to our knowledge, the first human case of P. lacrimosus infection in the world.

Elevated levels of thymus and activation-regulated chemokine (TARC) in pleural effusion samples from patients infested with Paragonimus westermani

To investigate the pathogenic mechanisms of eosinophilic pleural effusion in patients with paragonimiasis, we measured the levels of various chemokines including thymus and activation-regulated chemokine (TARC), eotaxin, RANTES and IL-8 in pleural effusion samples. Samples were obtained from 11 patients with Paragonimus westermani infection, six patients with pleural transudate, eight with tuberculous pleurisy and five with empyema. High percentages of eosinophils were detected in pleural fluid (range 9-100%, median 81%) of patients with paragonimiasis. TARC concentrations in pleural effusions of paragonimiasis were markedly higher than those of other groups. Eotaxin levels were also higher in pleural effusions of paragonimiasis patients, although significant difference was noted only against transudate samples. There was a significant correlation between TARC concentrations and percentages of eosinophils, and between TARC and eotaxin concentrations in pleural effusion. There were also significant correlations between TARC concentration and the titre of anti-P. westermani IgG and between eotaxin concentration and the titre of anti-P. westermani IgG. Our findings suggest that TARC contributes to the pathogenesis of eosinophilic pleural effusion in paragonimiasis.

Clinical features and parasite-specific IgM/IgG antibodies of paragonimiasis patients recently found in Japan

Clinical features of a total of 30 paragonimiasis westermani patients referred to and diagnosed in our laboratory in 1999 were analyzed retrospectively. Most patients were middle-aged (average: 48 years, range: 13-72 years) with the male/female ratio of 19/11. Over 70% of the patients had respiratory symptom and over 80% had peripheral blood eosinophilia and high serum IgE level. All but two cases had radiologic abnormalities on the chest X-ray. Only in 3 cases were Paragonimus eggs detected in the sputum smear. We classified the patients into two groups depending on the chest X-ray findings: patients having pleurisy alone and those having nodular/cavitating lesions in the lung parenchyma. We measured parasite specific IgM/IgG antibodies in all patients sera by microplate ELISA. The mean parasite-specific IgM/IgG antibody ratio was significantly higher in the parenchymatous lesion group than in the pleurisy group. While IgM antibody titer had a strong positive correlation with the degree of eosinophilia in peripheral blood, IgG antibody titer had an inverse correlation. Although the degree of eosinophilia in peripheral blood was higher in the pleurisy group than in the parenchymatous lesion group, total IgE level in serum was comparable between the two groups. The present results indicate that pleurisy with eosinophilia and dominant IgM antibody are the characteristic features of the early stage of paragonimiasis, whereas parenchymatous lesions in lungs with low grade eosinophilia and dominant IgG antibody are of the late stage. These results suggest that detection of IgM antibody should always be considered for the immunodiagnosis for paragonimiasis-suspected patients with pleurisy.

Current status of food-borne parasitic zoonoses in Japan

Epidemiological data on food-borne parasitic zoonoses in Japan is obscure because of the lack of legislated registration system for the incidence of such diseases. Attempts were made to draw rough estimates of the current status of food-borne parasitic diseases in Japan by gathering the annual incidence of each disease by literal survey and personal communications. In addition, parasitic diseases referred to and diagnosed in the Department of Parasitology, Miyazaki Medical College during 1999 were analyzed for the causative agents and the route of infection.

Natural resistance of 129/SvJ mice to Strongyloides venezuelensis infection

The susceptibility of 129/SvJ mice to infection with Strongyloides venezuelensis was compared with that of C57BL/6 mice. After a primary infection, daily egg output in faeces (EPG) from 129/SvJ mice was lower and terminated earlier than that from C57BL/6 mice. Adult worm recovery from the small intestine of 129/SvJ mice on day 7 was also lower than that of C57BL/6 mice. When the numbers of larvae recovered from the lungs were examined on days 2, 3 and 4 after a primary infection, they were comparable between the two strains. On the other hand, when an equal number of larvae recovered from the lungs of each strain on day 3 were implanted orally into homologous strain mice, the magnitude of EPG and the number of adult worms in the small intestine on day 5 after implantation were significantly lower in 129/SvJ than in C57BL/6 mice. The number of mucosal mast cells in the jejunum was not significantly different between 129/SvJ and C57BL/6 naive mice. Total chondroitin sulphate concentration in the gut washings obtained from naive mice was significantly higher in 129/SvJ (11.34 +/- 9.48) than in C57BL/6 mice (1.09 +/- 0.77, P < 0.05). These results indicate that the natural resistance of 129SvJ mice to S. venezuelensis infection is expressed at the intestine, probably due to higher concentration of chondroitin sulphate, which prevents establishment of S. venezuelensis.

Case report: Paragonimiasis westermani with seroconversion from immunoglobulin (Ig) m to IgG antibody with the clinical course

A 66-year-old man visited our hospital with primary complaint of cough. Chest roentgenogram showed slight pleural effusion and pneumothorax in the left lung. Eosinophilia (22.8%) was also found in his peripheral blood. Multiple-dot enzyme-linked immunosorbent assay (dot-ELISA) for the detection of parasite-specific immunoglobulin (Ig) G antibody was used to screen his serum against various parasitic diseases, but no significant binding was observed with any of the 12 parasite antigens examined, including those of Paragonimus westermani and P. miyazakii. Although he seemed to have been spontaneously cured without treatment, a nodular shadow appeared in the right upper medial lung field on the chest roentgenogram 6 months later. This time, his serum was positive for anti-P. westermani IgG antibody by the same method. A reexamination of the first and second admission serum samples for parasite-specific IgM and IgG antibodies revealed significant level of IgM antibody in the serum of the first admission, which had decreased at the time of the second admission. Conversely, the level of IgG antibody, which was low at the first admission, became dominant in the second admission serum 6 months later. These results clearly show that although the dot-ELISA to detect IgG antibody is generally useful for screening and detecting paragonimiasis, detection of IgM antibody seems to be a useful aid and should also be included in immunoserological diagnosis, especially if the patient is considered to be in the early stage of infection.

High-dose chemotherapy with hematopoietic stem cell transplantation is effective for nasal and nasal-type CD56+ natural killer cell lymphomas

CD56+ natural killer (NK) cell lymphomas occur frequently in the nasal and nasopharyngeal regions and carry a poor prognosis. We have studied seven cases with NK-cell lymphomas. These lymphomas showed the following immunophenotype: CD56+, CD2+, sCD3- and Epstein-Barr virus-encoded small RNAs (EBERs)+. Six patients had localized (stage I or II) disease involving the nasopharyngeal region, while one had stage III disease. One patient with stage I disease achieved a complete remission (CR) after treatment with involved-field irradiation, but subsequently relapsed and died. The remaining six patients received combination chemotherapy as primary treatment: five patients with localized stage I or II disease and one patient with advanced stage III disease. Responses to initial chemotherapy were generally poor. These six patients received a variety of salvage chemotherapy regimens, but never achieved a CR. Subsequently, four of six patients showed a highly aggressive clinical course and died of disseminated disease within 1 year from the diagnosis. Three of six patients received high-dose chemotherapy supported by syngeneic, autologous or allogeneic peripheral blood stem cell transplantation. Two of the three transplant patients achieved a CR and are now surviving in continuous CR. Our clinical experience suggests that myeloablative high-dose chemotherapy and bone marrow rescue by hematopoietic stem cell transplantation may be an effective salvage treatment modality for refractory NK-cell lymphomas and could be considered as a part of the initial therapy for these patients.

Administration of granulocyte colony-stimulating factor induces hyporesponsiveness to lipopolysaccharide and impairs antigen-presenting function of peripheral blood monocytes

OBJECTIVE

The incidence and severity of acute graft-vs-host disease after allogeneic transplantation of granulocyte colony-stimulating factor (G-CSF)-mobilized peripheral blood stem cells (PBSC) are not greater than those after conventional bone marrow transplantation despite infusion of more than one log greater number of donor T cells in PBSC. It has been postulated that monocytes from G-CSF-mobilized donors suppress alloreactivity of donor T cells.

MATERIALS AND METHODS

We investigated the phenotype and function of monocytes in normal individuals receiving 10 microg/kg of G-CSF for 4 days.

RESULTS

Monocytes were phenotypically and functionally different after G-CSF administration from steady-state monocytes. They were characterized by an increased CD14(+)CD16(+) subpopulation, reduced expression of HLA-DR, and diminished ability to produce tumor necrosis factor-alpha and interleukin-10 to lipopolysaccharide, compared with steady-state monocytes. These alterations were not replicated by culturing monocytes with G-CSF in vitro, suggesting an indirect effect of G-CSF. In addition, the antigen-presenting function of G-CSF-mobilized monocytes was impaired.

CONCLUSION

Hyporesponsiveness of G-CSF-treated monocytes to lipopolysaccharide with regard to tumor necrosis factor-alpha production, together with impaired antigen-presenting function, may be responsible for the unexpectedly low incidence of graft-vs-host disease after G-CSF-mobilized PBSC transplantation.

Adrenomedullin and proadrenomudullin N-terminal 20 peptide (PAMP) are present in human colonic epithelia and exert an antimicrobial effect

The hypotensive and vasorelaxing peptides adrenomedullin (AM) and its gene-related peptide, proadrenomedullin N-terminal 20 peptide (PAMP), were found to be distributed on the surface of the colonic mucosa. AM and PAMP showed dose-dependent antimicrobial activity against E. coli. The results suggest that the novel vasoactive peptides AM and PAMP play an important role in mucosal defence.

A rare case of eosinophilic pleuritis due to sparganosis

A rare form of sparganosis with eosinophilic pleural effusion is reported. A 62-year-old man was admitted to our hospital with left pleural effusion, and diagnosed immunologically as having sparganosis. Eosinophilia was seen in both peripheral blood and pleural effusion. The level of interleukin (IL)-5 was elevated in the pleural effusion, but not in peripheral blood. The patient was treated successfully with three consecutive doses of praziquantel (75 mg/ kg/day). After the treatment, the antibody titer in serum decreased and the eosinophil number in the peripheral blood returned to the normal level. Thus, sparganosis should be included in the differential diagnosis for eosinophilic pleuritis. The immunoserological screening test using multiple-dot ELISA is helpful to identify the causative pathogen.

Clinicoradiologic features of pleuropulmonary Paragonimus westermani on Kyusyu Island, Japan

STUDY OBJECTIVE

Recently, the number of new cases of Paragonimus westermani in humans has gradually increased, and paragonimiasis is a re-emerging public health issue in Kyusyu, Japan. We review our recent experience with pleuropulmonary Paragonimus westermani.

PATIENTS

Pulmonary paragonimiasis was diagnosed in 13 patients at the Third Department of Internal Medicine, Miyazaki Medical College between 1993 and 1999.

RESULTS

Both sputum and bronchoscopic examinations revealed ova in four of nine patients; bronchoscopy yielded ova in two additional patients. Twelve patients (92%) had respiratory symptoms, including cough (92%), sputum and/or hemoptysis (92%), and chest pain (46%). Chest radiography and CT showed pleural lesions (62%) and parenchymal lesions (92%). Of note was the high frequency of solitary nodular lesions (62%), mimicking lung cancer, tuberculosis, or fungal diseases. Immunodiagnosis and bronchoscopic examination were also useful for diagnosis. Praziquantel treatment was very effective and had minimal side effects. One patient required surgical decortication for empyema in spite of treatment with praziquantel. Eosinophilia was noted in peripheral blood and body fluids, which was probably due to increased levels of interleukin-5.

CONCLUSIONS

Our findings indicate that our patients with Paragonimus westermani presented with a wide variety of radiographic findings, which were different from the classic presentations reported earlier. Bronchoscopic examination and serologic tests are very useful for accurate diagnosis. As dietary habits change and international transportation increases, it appears likely that paragonimiasis will also increase in frequency in various parts of the world.

Synthetic peptide-based electrochemiluminescence immunoassay for anti-Borna disease virus p40 and p24 antibodies in rat and horse serum

Borna disease virus (BDV) is a neurotropic pathogen that infects a wide variety of vertebrates. We have developed a new electrochemiluminescence immunoassay (ECLIA) for the detection of antibodies to BDV, using three synthetic peptides corresponding to the amino acid residues 3-20 and 338-358 of p40 and 59-79 of p24 peptide of BDV. Using the ECLIA, we examined serum samples for the presence of anti-BDV antibodies in 20 rats (experimentally BDV-infected and uninfected) and 38 horses (13 US horses, experimentally infected and uninfected, and 25 Japanese horses, feral and domestic). The ECLIA, performed in a double-blind manner, detected anti-BDV antibodies in rats with a history of BDV infection, giving results that were in agreement with indirect immunofluorescence assay and/or Western blot (WB) analysis. The ECLIA also correctly identified all three experimentally infected horses and four domestic American horses that were seropositive for BDV antibodies by WB. Among the Japanese horses, at least two out of 10 feral and six out of 15 domestic horses were seropositive for BDV. In most of these cases, the specificity of immunoreactivity was verified by blocking with soluble p40 and p24 peptides.

Clinical Features of Paragonimiasis Cases Recently Found in Japan: Parasite‐Specific Immunoglobulin M and G Antibody Classes

We retrospectively analyzed clinical features in 30 patients who were referred to our laboratory and given a diagnosis of Paragonimus westermani infection in 1999. Our results indicate that pleurisy with eosinophilia and dominant immunoglobulin (Ig) M antibody are characteristic features of the early stage of paragonimiasis, whereas IgG antibody is dominant in the late stage. Thus, in addition to tests for parasite-specific IgG antibody, tests for IgM-class antibody should always be considered for patients with pleurisy in whom paragonimiasis is suspected.

Goblet cell hyperplasia in the airway of Nippostrongylus brasiliensis-infected rats

BACKGROUND

In rats, the intestinal parasite Nippostrongylus brasiliensis is recognized as a strong inducer of intestinal goblet cell hyperplasia. Although this parasite migrates through the airways during the course of its infection, airway goblet cell response remains unknown.

OBJECTIVE

This study was designed to examine airway goblet cell response during the course of N. brasiliensis infection in rats and to characterize these goblet cells.

METHODS

Airway goblet cells were stained with Alcian blue and periodic acid-Schiff. To characterize the goblet cells, mebendazole treatment, lectin histochemistry, and RNA blot analysis using probes for rat MUC2 and trefoil peptides were examined.

RESULTS

Airway and small intestinal goblet cell hyperplasia were observed at days 14 and 21 after infection but not at day 7. In rats treated with mebendazole, goblet cell hyperplasia was not present in the small intestine, but was observed in the lung on day 14. These results indicate that airway goblet cell hyperplasia may be induced by local pulmonary factors. By lectin histochemistry, the stainability of airway goblet cells at day 21 was similar to that of small intestine goblet cells even though rat MUC2 and trefoil peptide mRNA were not detected in the lung.

CONCLUSIONS

Airway goblet cell hyperplasia observed at days 14 and 21 after N. brasiliensis infection may be induced by local factors. Airway goblet cells have characteristics that differ from those of the small intestine.

[A case of myelitis caused by visceral larva migrans due to Ascaris suum presenting only with Lhermitte's sign]

A 27-year-old woman was admitted because of pain radiating through her back on neck flexion that had begun a month ago. She frequently ate raw beef liver. General physical examination revealed no abnormal findings, but she showed Lhermitte's sign neurologically. Fecal examination revealed no worm eggs. Blood cell counts showed mild eosinophilia (8.2%). The IgE level was mildly increased to 397 IU/ml (normal < 250). Cerebrospinal fluid examination showed 7 cells/microliter with 50% eosinophils. A test for anti-Ascaris suum IgG antibody was strongly positive in serum as well as in cerebrospinal fluid. Cervical MRI showed high-intensity areas in the spinal cord extending from the lower medulla to the C4 spine level on the T2-weighted images, and part of the lesion at the C3 spine level was enhanced by gadolinium. Treatment with albendazole 500 mg/day for six weeks ameliorated the Lhermitte's sign and MRI lesions, and reduced the anti-Ascaris suum antibody titers in the serum and cerebrospinal fluid. Larva migrans of Ascaris suum involving the central nervous system is considered to be extremely rare, but such cases showing mild neurologic impairment without systemic symptoms may have been overlooked.

[Allogeneic bone marrow transplantation for refractory multiple myeloma: presence of a graft-versus-myeloma effect]

We investigated the graft-versus-myeloma effect (GVM) after allogeneic bone marrow transplantation (allo-BMT). Three patients with refractory multiple myeloma (MM) underwent related allo-BMT. Two of the patients showed disappearance of serum M protein 4 and 5 months after transplantation, respectively. One of them has remained in complete remission for more than 22 months after allo-BMT, with accompanying chronic GVHD. Two patients with relapse and disease progression after allo-BMT underwent donor lymphocyte infusion (DLI). Although one patient did not respond to DLI, the other developed acute GVHD after 4 weeks and achieved a 75% reduction in serum M protein. DLI did not produce severe acute GVHD or myelosuppression. These findings suggest the presence of a GVM effect. DLI may be an effective therapy for patients with MM who have relapsed after allo-BMT. Furthermore, non-myeloablative stem cell transplantation (mini-transplantation) for refractory MM should be investigated further as a potentially curative option.

Microchimeric cells from the peripheral blood associated with cardiac grafts are bone marrow derived, long-lived and maintain acquired tolerance to minor histocompatibility antigen H-Y

BACKGROUND

Although it has been well established that the microchimerism occurs in the peripheral blood of the recipients after various settings in both clinical and experimental organ transplantation, nevertheless, their roles in inducing and maintaining acquired transplantation tolerance are controversial. Furthermore, regarding the cell lineages, kinetics, and functions of the cells that constitute the microchimerism after organ transplantation, solid information is not available.

METHODS

Using rat heterotopic heart isografts from bone marrow chimeras between cross-sex and applying polymerase chain reaction with specific primers to rat sex determining region of Y chromosome, a relationship between a state of microchimerism and induction as well as maintenance of acquired tolerance to H-Y antigen were examined.

RESULTS

Microchimeric cells of the peripheral blood (MCPB) after cardiac grafting contain bone marrow-derived and radiation-sensitive cells. Furthermore, removal of the primary cardiac grafts revealed that microchimeric cells in the peripheral blood are long-lived cells, i.e., more than 6 months. When the female rats that had contained long-lasting MCPB, were innoculated with syngeneic male dendritic cells, failure to sensitize female toward male specific antigen H-Y was found to occur.

CONCLUSIONS

Thus it was suggested that radiation-sensitive, bone marrow derived, long-lived MCPB play a significant role in maintaining acquired transplantation tolerance to minor histocompatibility antigen H-Y.