Virus-like particles with FLAG-tagged envelope protein as a tetravalent dengue vaccine candidate

The global incidence of dengue, which is caused by dengue virus (DENV) infection, has grown dramatically in recent decades and secondary infection with heterologous serotype of the virus may cause severe symptoms. Efficacious dengue vaccines should be able to provide long-lasting immunity against all four DENV serotypes simultaneously. In this study, we constructed a novel vaccine platform based on tetravalent dengue virus-like particles (DENV-LPs) in which envelope (E) protein carried a FLAG tag sequence at the position located not only in the exterior loop on the protruding domain but outside of dimerization interface of the protein. We demonstrated an effective strategy to produce the DENV-LPs by transient transfection with expression plasmids for pre-membrane and E proteins of DENV-1 to DENV-4 in mammalian cells and to concentrate and purify them with one-step affinity chromatography. Characteristic features of VLPs such as particle size, shape and density were comparable to flavivirus-like particles reported. The neutralizing activity against all four DENV serotypes was successfully induced by immunization with the purified tetravalent VLPs in mice. Simple, one-step purification systems for VLP vaccine platforms using epitope-tagging strategy should be advantageous for vaccine development not only for dengue but for emerging pandemics in the future.

P–015 Characterization of ultrastructural morphology of human sperms by field-emission scanning electron microscopy using the NanoSuit method

Study question

Can the NanoSuit method to observe sperm cells in wet conditions help treat male infertility using a field emission scanning electron microscope (FE-SEM)?

Summary answer

Compared with the conventional fixation method, the NanoSuit method can easily prepare FE-SEM samples without causing contraction and denaturation of human sperm cells.

What is known already

Evaluation of sperm morphology by optical microscopy is important for identifying male infertility. FE-SEM observation is useful for a more detailed evaluation of sperm morphology; however, a lot of the morphological information of the cells is lost by chemical fixation, dehydration, and freeze-drying. The NanoSuit method enables FE-SEM observation of unfixed cells under a high vacuum environment by electron beam polymerization of extracellular substances called NanoSuit. It has been reported that a sample prepared by the NanoSuit method retains the morphological information of live cells better than a sample prepared by the conventional fixation method.

Study design, size, duration

This laboratory study was conducted with informed consent and IRB approval. Semen parameters were within the WHO normal reference range.

Participants/materials, setting, methods

The conventional fixation method sample was prepared by fixing (glutaraldehyde and osmium), dehydration (ethanol and t-butyl alcohol), and freeze-drying. The NanoSuit method sample was introduced into the FE-SEM directly without conducting the above treatments. For observation, a JSM–7100F (JEOL, Japan) was used at an acceleration voltage of 1.0 kV. The vacuum level of the observation chamber was 10–3 to 10–6 Pa.

Main results and the role of chance

Sperm head segmentation (acrosome, equatorial segment, and post acrosome), midpiece, and tail including endpiece could be clearly identified in the FE-SEM sample prepared by the NanoSuit method. Transmission electron microscopy revealed the existence of a thin polymerized extra layer, the NanoSuit, on the surface of the sperm. It is suggested that the presence of the NanoSuit layer enables FE-SEM observation of the unfixed sperm. The conventional fixation method causes a statistically significant contraction in the sperm head size compared to that calculated from optical micrographs (13.5 μm2 vs. 11.6 μm2, p < 0.001). Furthermore, wheat germ agglutinin (WGA), a lectin, which is known to have the ability to bind to the sperm surface, did not bind to the fixed FE-SEM samples. This means that the original cell surface properties are lost in the fixed sperm sample. On the other hand, the FE-SEM sample prepared by the NanoSuit method did not show a statistically significant contraction of the sperm head compared to that calculated from optical micrographs (13.2 μm2 vs 12.9 μm2, p = 0.416); it also revealed a detailed binding pattern of gold-labelled WGA to the sperm surface. These results indicate that the NanoSuit method can prepare FE-SEM samples without sperm contraction and denaturation.

Limitations, reasons for caution

Characteristic sperm morphology in patients with male infertility should be investigated in future studies.

Wider implications of the findings: The NanoSuit method does not use chemical carcinogens and can prepare an FE-SEM sample in a shorter time than the conventional fixation method. The evaluation of ultrastructural morphology of unfixed sperms by this method may be useful for the identification of new morphological features and the evaluation of male infertility.

Trial registration number

Not applicable

Agglutination of Human Polyomaviruses by Using a Tetravalent Glycocluster as a Cross-Linker

Two kinds of tetravalent double-headed sialo-glycosides with short/long spacers between the Neu5Acα2,6Galβ1,4GlcNAc unit and ethylene glycol tetraacetic acid (EGTA) scaffold were found to be capable of binding to virus-like particles of Merkel cell polyomavirus (MCPyV-LP). The binding process and time course of interaction between the tetravalent ligand and MCPyV-LP were assessed by dynamic light scattering (DLS). On the addition of increasing concentrations of ligand to MCPyV-LP, larger cross-linked aggregates formed until a maximum size was reached. The binding was stronger for the tetravalent ligand with a short spacer than for that with a long spacer. The binding of the former ligand to the virus was observed to proceed in two stages during agglutination. The first step was the spontaneous formation of small aggregates comprising the cross-linked ligand-virus complex. In the second step, the aggregates grew successively larger by cooperative binding among the initially produced small aggregates. In transmission electron microscopy, the resulting complex was observed to form aggregates in which the ligands were closely packed with the virus particles. The cross-linked interaction was further confirmed by a simple membrane filtration assay in which the virus-like particles were retained on the membrane when complexed with a ligand. The assay also showed the effective capture of particles of pathogenic, infectious human polyomavirus JCPyV when complexed with a ligand, suggesting its possible application as a method for trapping viruses by filtration under conditions of virus aggregation. Collectively, these results show that the tetravalent glycocluster serves as a ligand not only for agglutinating MCPyV-LP but also for trapping the pathogenic virus.

Utility of Scanning Electron Microscopy Elemental Analysis Using the 'NanoSuit' Correlative Light and Electron Microscopy Method in the Diagnosis of Lanthanum Phosphate Deposition in the Esophagogastroduodenal Mucosa

BACKGROUND

We have recently developed the correlative light and electron microscopy of hematoxylin and eosin (H&E)-stained glass slides using the 'NanoSuit' method. The aim of this study is to explore the utility of the new NanoSuit-correlative light and electron microscopy method combined with scanning electron microscopy-energy dispersive X-ray spectroscopy elemental analysis for the diagnosis of lanthanum phosphate deposition in the H&E-stained glass slides.

METHODS

Nine H&E-stained glass slides of the upper gastrointestinal tract mucosa containing the brown pigmented areas by light microscopic observation, which were suspected as lanthanum phosphate deposition, were observed and analyzed by scanning electron microscopy-energy dispersive X-ray spectroscopy using the NanoSuit-correlative light and electron microscopy method.

RESULTS

In all nine slides, the new NanoSuit-correlative light and electron microscopy method combined with scanning electron microscopy-energy dispersive X-ray spectroscopy revealed the accumulation of both lanthanum and phosphorus in the tissue area corresponding to the brown pigment deposition. In addition to the existence of lanthanum phosphate in the stomach and duodenum, known target organs, we observed deposition in the esophagus for the first time. Furthermore, we observed lanthanum phosphate deposition in the background mucosa of stomach containing primary adenocarcinoma.

CONCLUSIONS

Scanning electron microscopy-energy dispersive X-ray spectroscopy analysis using the NanoSuit-correlative light and electron microscopy method is useful for the diagnosis of lanthanum phosphate deposition in the H&E-stained glass slides. Lanthanum phosphate deposition occurs not only in the stomach and duodenum but also in the esophagus.

First Detection of Photons with Energy beyond 100 TeV from an Astrophysical Source

We report on the highest energy photons from the Crab Nebula observed by the Tibet air shower array with the underground water-Cherenkov-type muon detector array. Based on the criterion of a muon number measured in an air shower, we successfully suppress 99.92% of the cosmic-ray background events with energies E>100  TeV. As a result, we observed 24 photonlike events with E>100  TeV against 5.5 background events, which corresponds to a 5.6σ statistical significance. This is the first detection of photons with E>100  TeV from an astrophysical source.

The cosmic ray energy spectrum measured with the new Tibet hybrid experiment

We have upgraded the new Tibet ASgamma experiment in China since 2014 to measure the chemical composition of cosmic rays around the knee. This hybrid experiment consist of an air-shower-core detector array (YAC-II) to detect high energy electromagnetic component, the Tibet air-shower array (Tibet-III) and a large underground water-Cherenkov muon-detector array (MD). We have carried out a detailed air-shower Monte Carlo (MC) simulation to study the performance of the hybrid detectors by using CORSIKA (version 7.5000), which includes EPOS-LHC, QGSJETII-04, SIBYLL2.1 and SIBYLL2.3 hadronic interaction models. The preliminary results of the interaction model checking above 50 TeV energy region are reported in this paper, and the primary proton and helium spectra in the energy range 50 TeV to 1015 eV was derived from YAC-I data and is smoothly connected with direct observation data at lower energies and also with our previously reported works at higher energies within statistical errors. The knee of the (P+He) spectra is located around 400 TeV. The interaction model dependence in deriving the primary (P+He) spectra is found to be small (less than 25% in absolute intensity, 10% in position of the knee), and the composition model dependence is less than 10% in absolute intensity.

Test of the hadronic interaction models SIBYLL2.3, EPOS-LHC and QGSJETII- 04 with Tibet EAS core data

A hybrid experiment has been started by the ASγ experiment at Yangbajing (4300m a.s.l.) in Tibet since May 2009, that consists of a high-energy air-shower-core array (YAC-I) and a high-density air-shower array (Tibet-III). In this paper, we report our results to check the hadronic interaction models SIBYLL2.3, SIBYLL2.1, EPOS-LHC and QGSJETII-04 in the multi-tens TeV energy region using YAC-I+Tibet-III experimental data from May 2009 through January 2010. The effective live time is calculated as 106.05 days. The results show that the description of transverse momentum, inelastic cross-section and inelasticity for the 4 hadronic interaction models is consistent with YAC-I experimental data within 15% systematic errors range in the forward region below 100 TeV. Among them, the EPOS-LHC model is the best hadronic interaction model. Furthermore, we find that the H4a composition model is the best one below the 100 TeV energy region.

On the Solar Cycle Variation of the Solar Diurnal Anisotropy of Multi-TeV Cosmic-ray Intensity Observed with the Tibet Air Shower Array

We analyze the temporal variation of the solar diurnal anisotropy of the multi-TeV cosmic-ray intensity observed with the Tibet air shower array from 2000 to 2009, covering the maximum and minimum of the 23rd solar cycle. We comfirm that a remarkable additional anisotropy component is superposed on the Compton-Getting anisotropy at 4.0 TeV, while its amplitude decreases at higher energy regions. In constrast to the additional anisotropy reported by the Matsushiro experiment at 0.6 TeV, we find the residual component measured by Tibet at multi-TeV energies is consistent with being stable, with a fairly constant amplitude of 0.041% ± 0.003% and a phase at around 07.17 ± 00.16 local solar time at 4.0 TeV. This suggests the additional anisotropy observed by the Tibet experiment could result from mechanisms unrelated to solar activities.

Evaluation of the Interplanetary Magnetic Field Strength Using the Cosmic-Ray Shadow of the Sun

We analyze the Sun's shadow observed with the Tibet-III air shower array and find that the shadow's center deviates northward (southward) from the optical solar disk center in the "away" ("toward") interplanetary magnetic field (IMF) sector. By comparing with numerical simulations based on the solar magnetic field model, we find that the average IMF strength in the away (toward) sector is 1.54±0.21_{stat}±0.20_{syst} (1.62±0.15_{stat}±0.22_{syst}) times larger than the model prediction. These demonstrate that the observed Sun's shadow is a useful tool for the quantitative evaluation of the average solar magnetic field.

Abstract 1862: Direct observation of colorectal cancers using field-emission scanning electron microscopy with a thin polymer membrane, the NanoSuit

Background: Field-emission scanning electron microscopy (FE-SEM) enables us to observe nano-sized objects with great depth of focus and high resolution. However, the observation of biological samples including colorectal tissues using an FE-SEM has been difficult because it requires to evacuate its inside to prevent electron scattering, therefore all organisms containing ca. 70% water are rapidly evaporated and consequently caused structural disruption and collapse. To overcome the limitations of the conventional SEM, equipment such as low-vacuum scanning electron microscopy and environmental scanning electron microscope was developed. However, they are not reliable enough to investigate living organisms or wet tissues with high resolution level. We have recently reported that a simple surface modification consisting of a thin extra layer, coined the term ‘NanoSuit®’, can keep organisms alive in the high vacuum (10−3 to 10−7 Pa) of the SEM. We now modified the technique and developed a new solution, which enables FE-SEM observations of wet tissues. In this study, we utilized this technique to observe real images of colorectal cancers and their adjacent normal mucosae at high resolution.

Materials and methods: Colorectal cancer tissues and their adjacent normal mucosa were cut with a scalpel from specimens surgically resected. All patients enrolled in this study provided written informed consent. Observations were carried out with an FE-SEM (S-4800, Hitachi or JEM-7100F, JEOL, Japan) at acceleration voltage of 1.0 kV. The vacuum level of the observation chamber was 10-3 - 10-7 Pa. The newly developed surface shield enhancer (SSE) solution was used to make NanoSuit® for wet tissue observation. To form the NanoSuit®, the specimens were dipped for 1 min into the SSE solution and blotted briefly thereafter put on dry filter paper to remove excess solution. Specimens were then introduced directly into an FE-SEM to form a NanoSuit® following irradiation of the electron beam.

Results: Fine structures of intestinal crypt and villi were observed in normal colon mucosa using FE-SEM with a NanoSuit®, whereas fixed specimens prepared with conventional method showed obvious structural damage. Comparing with the region of normal colon mucosa, colorectal cancer lesion had relatively amorphous surface, therefore the border between non-cancerous mucosa and cancer lesions in colon tissues are able to be distinguished under high magnification. In addition, fiber-like structure was observed at the border between noncancerous mucosa and cancer lesions, suggesting an invasive front of colorectal cancer.

Conclusions: We successfully observed the real mucosal surfaces and cancer lesions of colorectum with high resolution by an FE-SEM using a newly developed vacuum-proof suit, the “NanoSuit®”. This novel technique will enable us to investigate further physiopathology of GI tract including cancers.

Citation Format: Hirotoshi Kikuchi, Tomohiro Matsumoto, Takanori Hiraide, Yusuke Ozaki, Amane Hirotsu, Tomohiro Murakami, Toshiki Kawabata, Yoshihiro Hiramatsu, Kinji Kamiya, Takanori Sakaguchi, Yasuharu Takaku, Isao Ohta, Takahiro Hariyama, Hiroyuki Konno. Direct observation of colorectal cancers using field-emission scanning electron microscopy with a thin polymer membrane, the NanoSuit [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1862. doi:10.1158/1538-7445.AM2017-1862

A modified 'NanoSuit®' preserves wet samples in high vacuum: direct observations on cells and tissues in field-emission scanning electron microscopy

Although field-emission scanning electron microscopy (FE-SEM) has proven very useful in biomedical research, the high vacuum required (10^-3 to 10^-7 Pa) precludes direct observations of living cells and tissues at high resolution and often produces unwanted structural changes. We have previously described a method that allows the investigator to keep a variety of insect larvae alive in the high vacuum environment of the electron microscope by encasing the organisms in a thin, vacuum-proof suit, the 'NanoSuit®'. However, it was impossible to protect wet tissues freshly excised from intact organisms or cultured cells. Here we describe an improved 'NanoSuit' technique to overcome this limitation. We protected the specimens with a surface shield enhancer (SSE) solution that consists of glycerine and electrolytes and found that the fine structure of the SSE-treated specimens is superior to that of conventionally prepared specimens. The SSE-based NanoSuit affords a much stronger barrier to gas and/or liquid loss than the previous NanoSuit did and, since it allows more detailed images, it could significantly help to elucidate the 'real' organization of cells and their functions.

A 'NanoSuit' surface shield successfully protects organisms in high vacuum: observations on living organisms in an FE-SEM

Although extremely useful for a wide range of investigations, the field emission scanning electron microscope (FE-SEM) has not allowed researchers to observe living organisms. However, we have recently reported that a simple surface modification consisting of a thin extra layer, termed 'NanoSuit', can keep organisms alive in the high vacuum (10(-5) to 10(-7) Pa) of the SEM. This paper further explores the protective properties of the NanoSuit surface-shield. We found that a NanoSuit formed with the optimum concentration of Tween 20 faithfully preserves the integrity of an organism's surface without interfering with SEM imaging. We also found that electrostatic charging was absent as long as the organisms were alive, even if they had not been coated with electrically conducting materials. This result suggests that living organisms possess their own electrical conductors and/or rely on certain properties of the surface to inhibit charging. The NanoSuit seems to prolong the charge-free condition and increase survival time under vacuum. These findings should encourage the development of more sophisticated observation methods for studying living organisms in an FE-SEM.

Structural and immunological effects of skin cryoablation in a mouse model

Cryoablation is therapeutically applied for various disorders in several organs, and skin diseases are typical targets as this cryotherapy has been widely used for viral warts, benign tumors, and actinic keratosis. The main mechanisms of cryoablation consist of direct freezing effect on skin constituents, thrombosis formation in microcirculation, and subsequent immunological responses. Among them, however, the immunological mechanism remains unelucidated, and it is an issue how the direct freezing injury induces immunological consequences. We established a mouse cryoablation model with liquid nitrogen applied to the shaved back skin, and used this system to study the immunological excitement. After application of liquid nitrogen, the thermal decrease ratio was -25°C/sec or less and the lowest temperature was less than -100°C, which was sufficient to induce ulceration. Destruction of cornified layer and necrosis of epidermal cells were observed in transmission electron microscopy image, and increased transepidermal water loss and skin permeability were detected by the functional measurements. By flow cytometry, antigen-presenting dendritic cells (DCs), including PDCA1+B220+CD19- plasmacytoid DCs (pDCs) and CD11c+ myeloid DCs, as well as neutrophils and macrophages were increased in subcutaneous tissue. In parallel, the mRNA expressions of interferon α1 which are known as pDC-producing cytokines, was elevated. We also found marked degranulation of mast cells, providing a possibility that released histamine attracts pDCs. Finally, FITC migration assay revealed that pDCs and CD11c+ DCs emigrated from the cryoablated skin to the draining lymph nodes. Our study suggests that cryoablation induces destruction of the barrier/epidermis, accumulation of pDCs and CD11c+ DCs to the skin, and migration of DCs to regional lymph nodes. Viral elements or tumor cell lysates released from damaged keratinocytes may stimulate the DCs, thereby leading to antiviral or antitumor effect.

Dressing living organisms in a thin polymer membrane, the NanoSuit, for high-vacuum FE-SEM observation

Scanning electron microscopy (SEM) has made remarkable progress and has become an essential tool for observing biological materials at microscopic level. However, various complex procedures have precluded observation of living organisms to date. Here, a new method is presented by which living organisms can be observed by field emission (FE)-SEM. Using this method, active movements of living animals were observed in vacuo (10(-5)-10(-7) Pa) by protecting them with a coating of thin polymer membrane, a NanoSuit, and it was found that the surface fine structure of living organisms is very different from that of traditionally fixed samples. After observation of mosquito larvae in the high vacuum of the FE-SEM, it was possible to rear them subsequently in normal culture conditions. This method will be useful for numerous applications, particularly for electron microscopic observations in the life sciences.

In situ preparation of biomimetic thin films and their surface-shielding effect for organisms in high vacuum

Self-standing biocompatible films have yet to be prepared by physical or chemical vapor deposition assisted by plasma polymerization because gaseous monomers have thus far been used to create only polymer membranes. Using a nongaseous monomer, we previously found a simple fabrication method for a free-standing thin film prepared from solution by plasma polymerization, and a nano-suit made by polyoxyethylene (20) sorbitan monolaurate can render multicellular organisms highly tolerant to high vacuum. Here we report thin films prepared by plasma polymerization from various monomer solutions. The films had a flat surface at the irradiated site and were similar to films produced by vapor deposition of gaseous monomers. However, they also exhibited unique characteristics, such as a pinhole-free surface, transparency, solvent stability, flexibility, and a unique out-of-plane molecular density gradient from the irradiated to the unirradiated surface of the film. Additionally, covering mosquito larvae with the films protected the shape of the organism and kept them alive under the high vacuum conditions in a field emission-scanning electron microscope. Our method will be useful for numerous applications, particularly in the biological sciences.

Probe of the solar magnetic field using the "cosmic-ray shadow" of the sun

We report on a clear solar-cycle variation of the Sun’s shadow in the 10 TeV cosmic-ray flux observed by the Tibet air shower array during a full solar cycle from 1996 to 2009. In order to clarify the physical implications of the observed solar cycle variation, we develop numerical simulations of the Sun’s shadow, using the potential field source surface model and the current sheet source surface (CSSS) model for the coronal magnetic field. We find that the intensity deficit in the simulated Sun’s shadow is very sensitive to the coronal magnetic field structure, and the observed variation of the Sun’s shadow is better reproduced by the CSSS model. This is the first successful attempt to evaluate the coronal magnetic field models by using the Sun’s shadow observed in the TeV cosmic-ray flux.

Kallikrein-related peptidase 5 functions in proteolytic processing of profilaggrin in cultured human keratinocytes

Filaggrin protein is synthesized in the stratum granulosum of the skin and contributes to the formation of the human skin barrier. Profilaggrin is cleaved by proteolytic enzymes and converted to functional filaggrin, but its processing mechanism remains not fully elucidated. Kallikrein-related peptidase 5 (KLK5) is a major serine protease found in the skin, which is secreted from lamellar granules following its expression in the stratum granulosum and activated in the extracellular space of the stratum corneum. Here, we searched for profilaggrin-processing protease(s) by partial purification of epidermal extracts and found KLK5 as a possible candidate. We used high performance liquid chromatography coupled with electrospray tandem mass spectrometry to show that KLK5 cleaves profilaggrin. Furthermore, based on a proximity ligation assay, immunohistochemistry, and immunoelectron microscopy analysis, we reveal that KLK5 and profilaggrin co-localize in the stratum granulosum in human epidermis. KLK5 knockdown in normal cultured human epidermal keratinocytes resulted in higher levels of profilaggrin, indicating that KLK5 potentially functions in profilaggrin cleavage.

Resistance of a rodent malaria parasite to a thymidylate synthase inhibitor induces an apoptotic parasite death and imposes a huge cost of fitness

Background

The greatest impediment to effective malaria control is drug resistance in Plasmodium falciparum, and thus understanding how resistance impacts on the parasite's fitness and pathogenicity may aid in malaria control strategy.

Methodology/Principal Findings

To generate resistance, P. berghei NK65 was subjected to 5-fluoroorotate (FOA, an inhibitor of thymidylate synthase, TS) pressure in mice. After 15 generations of drug pressure, the 2% DT (the delay time for proliferation of parasites to 2% parasitaemia, relative to untreated wild-type controls) reduced from 8 days to 4, equalling the controls. Drug sensitivity studies confirmed that FOA-resistance was stable. During serial passaging in the absence of drug, resistant parasite maintained low growth rates (parasitaemia, 15.5%±2.9, 7 dpi) relative to the wild-type (45.6%±8.4), translating into resistance cost of fitness of 66.0%. The resistant parasite showed an apoptosis-like death, as confirmed by light and transmission electron microscopy and corroborated by oligonucleosomal DNA fragmentation.

Conclusions/Significance

The resistant parasite was less fit than the wild-type, which implies that in the absence of drug pressure in the field, the wild-type alleles may expand and allow drugs withdrawn due to resistance to be reintroduced. FOA resistance led to depleted dTTP pools, causing thymineless parasite death via apoptosis. This supports the tenet that unicellular eukaryotes, like metazoans, also undergo apoptosis. This is the first report where resistance to a chemical stimulus and not the stimulus itself is shown to induce apoptosis in a unicellular parasite. This finding is relevant in cancer therapy, since thymineless cell death induced by resistance to TS-inhibitors can further be optimized via inhibition of pyrimidine salvage enzymes, thus providing a synergistic impact. We conclude that since apoptosis is a process that can be pharmacologically modulated, the parasite's apoptotic machinery may be exploited as a novel drug target in malaria and other protozoan diseases of medical importance.

Analysis of intra-GBM microstructures in a SLE case with glomerulopathy associated with podocytic infolding

BACKGROUND

Systemically podocytic infolding into the GBM which causes nonargyrophilic holes in the GBM in association with intra-GBM microstructures has been considered as a new pathological entity. However, its pathomechanisms are largely unknown.

METHODS

We analyzed intra-GBM microstructures in an SLE patient with glomerulopathy associated with podocytic infolding by immunoelectron microscopy for vimentin (a marker for both podocyte and endothelium) and C5b-9 and by 3D reconstruction of transmission electron microscopy (TEM) images by computer tomography method.

RESULTS

Immunofluorescent study showed immunoglobulin deposition in a diffuse, capillary pattern; however, electron-dense deposits like stage 3 membranous nephropathy could be found only in some capillary loops by TEM in spite of the systemic existence of podocytic infolding and the intra-GBM microstructures. Three-dimensional reconstructed images of the TEM images revealed that some of the intra-GBM microstructures made connections with the podocyte. The clustered microstructures underneath the podocyte and their surroundings looked as a whole like the degraded part of podocyte in 3D reconstructed images. Immunoelectron microscopy showed that vimentin was positive in most intra-GBM microstructures. C5b-9 was positive along the entire epithelial side of the GBM and in some microstructures, suggesting that the podocytes may be attacked by C5b-9 and that the microstructures may contain C5b-9 bound cellular membranes.

CONCLUSION

Intra-GBM microstructures may be originated mainly from the podocyte. Podotyte and GBM injuries caused by C5b-9 attack to podocytes might contribute in part to podocytic infolding and intra-GBM microstructures in this case.

Anisotropy and Corotation of Galactic Cosmic Rays

The intensity of Galactic cosmic rays is nearly isotropic because of the influence of magnetic fields in the Milky Way. Here, we present two-dimensional high-precision anisotropy measurement for energies from a few to several hundred teraelectronvolts (TeV), using the large data sample of the Tibet Air Shower Arrays. Besides revealing finer details of the known anisotropies, a new component of Galactic cosmic ray anisotropy in sidereal time is uncovered around the Cygnus region direction. For cosmic-ray energies up to a few hundred TeV, all components of anisotropies fade away, showing a corotation of Galactic cosmic rays with the local Galactic magnetic environment. These results have broad implications for a comprehensive understanding of cosmic rays, supernovae, magnetic fields, and heliospheric and Galactic dynamic environments.

Observation by an air-shower array in Tibet of the multi-TeV cosmic-ray anisotropy due to terrestrial orbital motion around the Sun

We report on the solar diurnal variation of the galactic cosmic-ray intensity observed by the Tibet III air shower array during the period from 1999 to 2003. In the higher-energy event samples (12 and 6.2 TeV), the variations are fairly consistent with the Compton-Getting anisotropy due to the terrestrial orbital motion around the Sun, while the variation in the lower-energy event sample (4.0 TeV) is inconsistent with this anisotropy. This suggests an additional anisotropy superposed at the multi-TeV energies, e.g., the solar modulation effect. This is the highest-precision measurement of the Compton-Getting anisotropy ever made.

Massive rhabdomyolysis and acute renal failure after acetonitrile exposure

A case of systemic rhabomyolysis after acetonitrile exposure is reported. A 35-year-old previously healthy man suffered from vomiting, convulsion and consciousness loss 15 hours after exposure to acetonitrile. Since acetonitrile is known to be metabolized into cyanide, antidote therapy against cyanide poisoning was given. On admission, pain and all-over muscle swelling were marked. Although the initial therapy was effective, rhabdomyolysis and then acute renal failure developed. Renal function improved very slowly after six weeks of hemodialysis, but atrophy of the muscles remained. The rhabdomyolysis may have been caused by toxicity of the cyanide itself in combination with hypoxia and convulsion.

Relationship between triglyceride concentrations and LDL size evaluated by malondialdehyde-modified LDL

BACKGROUND

Hypertriglyceridemia is associated with decreased HDL-cholesterol (HDL-C) and increased small dense LDL. In addition, small dense LDL is known to be susceptible to oxidation.

METHODS

We measured LDL particle size, using gradient gel electrophoresis, and malondialdehyde-modified LDL (MDA-LDL), using an ELISA, and investigated the association between triglyceride (TG) concentrations, LDL size, and MDA-LDL.

RESULTS

TG concentrations correlated negatively with the predominant LDL size (r = -0.650) and HDL-C concentration (r = -0.556). The relationship between TG concentration and LDL size, evaluated by measuring MDA-LDL, distinguished subgroups derived from four subfractions of TG concentrations and four distribution ranges of LDL size. These experiments indicated that there is a threshold for oxidation susceptibility at an LDL size of 25.5 nm and a TG concentration of 1500 mg/L. To investigate the relationship between LDL size, MDA-LDL concentration, and other lipids (TGs, HDL-C, apolipoprotein B, and total cholesterol), we evaluated them in control subjects and patients with diabetes mellitus or hypertriglyceridemia. When the size range for normal LDL was postulated to be 25.5 < or = phi (LDL diameter) < 26.5 nm, the MDA-LDL concentration was significantly higher in the subgroups of patients with LDL in the size range 24.5 < or = phi < 25.5 nm compared with patients with normal LDL. This result also suggests that the threshold is at a LDL size of 25.5 nm.

CONCLUSION

The threshold for oxidation susceptibility coincided with the point of LDL size separation between the LDL subclass patterns A and B as an atherosclerotic risk.

Relationship between Triglyceride Concentrations and LDL Size Evaluated by Malondialdehyde-modified LDL

Background: Hypertriglyceridemia is associated with decreased HDL-cholesterol (HDL-C) and increased small dense LDL. In addition, small dense LDL is known to be susceptible to oxidation.

Methods: We measured LDL particle size, using gradient gel electrophoresis, and malondialdehyde-modified LDL (MDA-LDL), using an ELISA, and investigated the association between triglyceride (TG) concentrations, LDL size, and MDA-LDL.

Results: TG concentrations correlated negatively with the predominant LDL size (r = −0.650) and HDL-C concentration (r = −0.556). The relationship between TG concentration and LDL size, evaluated by measuring MDA-LDL, distinguished subgroups derived from four subfractions of TG concentrations and four distribution ranges of LDL size. These experiments indicated that there is a threshold for oxidation susceptibility at an LDL size of 25.5 nm and a TG concentration of 1500 mg/L. To investigate the relationship between LDL size, MDA-LDL concentration, and other lipids (TGs, HDL-C, apolipoprotein B, and total cholesterol), we evaluated them in control subjects and patients with diabetes mellitus or hypertriglyceridemia. When the size range for normal LDL was postulated to be 25.5 ≤ φ (LDL diameter) &lt; 26.5 nm, the MDA-LDL concentration was significantly higher in the subgroups of patients with LDL in the size range 24.5 ≤ φ &lt; 25.5 nm compared with patients with normal LDL. This result also suggests that the threshold is at a LDL size of 25.5 nm.

Conclusion: The threshold for oxidation susceptibility coincided with the point of LDL size separation between the LDL subclass patterns A and B as an atherosclerotic risk.

Cyclophosphamide and 5-fluorouracil act synergistically in ovarian clear cell adenocarcinoma cells

Chemosensitivity to the drugs plays a crucial role in the treatment of ovarian cancer. In this study, we evaluate the cytotoxicity of chemotherapeutic agents in six ovarian cancer cell lines; four clear cell adenocarcinoma and two serous papillary adenocarcinoma, using seven single drugs and seven sets of drug combinations with tetrazolium-based semiautomated colorimetric (MTT) assay. The drug concentration which produced 50% growth inhibition (IC50) of cisplatin was within clinically achievable range in five cell lines. The area under the curve (AUC) at IC50 of cyclophosphamide was below the clinically achievable AUC in two serous papillary cell lines. Paclitaxel was more effective in clear cells than serous papillary cells. The intensification of cytotoxicity was observed in the combinations of paclitaxel and cisplatin, and cyclophosphamide and cisplatin or 5-fluorouracil irrespective of histopathological characteristics of the original tumor. Our results indicate that ovarian cancer cell lines respond to chemotherapeutic agents heterogeneously depending upon histopathological features, indicating individualized regimens may improve survival in ovarian cancer patients.

Percutaneous transhepatic placement of metallic stents in the treatment of complicated intrahepatic biliary stricture with hepatolithiasis: a preliminary report

OBJECTIVE

We aimed to study the effect of the metallic modified Gianturco-Rosch Z-stent in the management of refractory intrahepatic long-segment biliary strictures with hepatolithiasis.

METHODS

Six symptomatic patients with hepatolithiasis and coexisting intrahepatic long-segment biliary strictures, who failed to respond to the silastic external-internal biliary stenting, were selected. The metallic modified Gianturco-Rosch Z-stent was placed via percutaneous transhepatic cholangiography at the strictured site. Patients were followed regularly to evaluate for recurrence of cholangitis, stones, or strictures.

RESULTS

No complications were observed during the procedures. No recurrent strictures or formed calculi were found in these six patients during follow-up periods of 29 to 64 months. However, cholangitis and intrahepatic biliary muddy sludge occurred at 7 and 30 months in two patients after the placement of the metallic Z-stent. Percutaneous transhepatic cholangioscopy was used to clear sludge completely.

CONCLUSIONS

Our experience suggests that the metallic stent is a well-tolerated and promising alternative in the management of refractory intrahepatic long-segment biliary strictures with hepatolithiasis. Though biliary sludge may develop, it can be detected and cleared early. Repeated surgery can thus be avoided.

Observation of Multi-TeV Gamma Rays from the Crab Nebula using the Tibet Air Shower Array

The Tibet experiment, operating at Yangbajing (4300 m above sea level), is the lowest energy air shower array, and the new high-density array constructed in 1996 is sensitive to gamma-ray air showers at energies as low as 3 TeV. With this new array, the Crab Nebula was observed in multi-TeV gamma-rays and a signal was detected at the 5.5 sigma level. We also obtained the energy spectrum of gamma-rays in the energy region above 3 TeV which partially overlaps those observed with imaging atmospheric Cerenkov telescopes. The Crab spectrum observed in this energy region can be represented by the power-law fit dJ&parl0;E&parr0;&solm0;dE=&parl0;4.61+/-0.90&parr0;x10-12&parl0;E&solm0;3 TeV&parr0;-2.62+/-0.17 cm-2 s-1 TeV-1. This is the first observation of gamma-ray signals from point sources with a conventional air shower array using scintillation detectors.

Dynamic reaction in a homogeneous HDL-cholesterol assay visualized by electron microscopy

BACKGROUND

Measurement of HDL-cholesterol (HDL-C) by homogeneous assays with automated analyzers is replacing precipitation methods. However, in this reaction-type assay, interactions between the reagents and lipoproteins remain unknown.

METHODS

Electron microscopy was used to investigate the reactions in a homogeneous HDL-C assay. Negative staining with 10 g/L uranyl acetate was performed for lipoprotein visualization by electron microscopy. Observations of the interactions between lipoproteins and the reagents of a polyanion-polymer/detergent assay were achieved by cooling the reaction mixture in ice water. This treatment also allowed observation of the time course of the reaction.

RESULTS

In the first-reagent reaction (polyanion-polymer), every lipoprotein aggregated almost completely. In the second-reagent reaction (enzymes and detergent), only HDL in the lipoprotein aggregates was selectively resolved and reacted enzymatically. Reagent 1 contains two important substances: polyanion and synthetic polymer. Using x-ray microanalysis, we confirmed that aggregation of lipoproteins in the first reaction occurred through interaction with the phosphotungstate of the polyanion.

CONCLUSION

Electron microscopy morphologically revealed the dynamic reaction in a homogeneous HDL-C assay.

Dynamic Reaction in a Homogeneous HDL-Cholesterol Assay Visualized by Electron Microscopy

Background: Measurement of HDL-cholesterol (HDL-C) by homogeneous assays with automated analyzers is replacing precipitation methods. However, in this reaction-type assay, interactions between the reagents and lipoproteins remain unknown.

Methods: Electron microscopy was used to investigate the reactions in a homogeneous HDL-C assay. Negative staining with 10 g/L uranyl acetate was performed for lipoprotein visualization by electron microscopy. Observations of the interactions between lipoproteins and the reagents of a polyanion-polymer/detergent assay were achieved by cooling the reaction mixture in ice water. This treatment also allowed observation of the time course of the reaction.

Results: In the first-reagent reaction (polyanion-polymer), every lipoprotein aggregated almost completely. In the second-reagent reaction (enzymes and detergent), only HDL in the lipoprotein aggregates was selectively resolved and reacted enzymatically. Reagent 1 contains two important substances: polyanion and synthetic polymer. Using x-ray microanalysis, we confirmed that aggregation of lipoproteins in the first reaction occurred through interaction with the phosphotungstate of the polyanion.

Conclusion: Electron microscopy morphologically revealed the dynamic reaction in a homogeneous HDL-C assay.

[Effective mechanisms of ATX-S10, a new photosensitizer, on HeLa tumors in nude mice]

Photodynamic therapy (PDT) is a treatment modality that utilizes a photosensitizing drug activated by laser generated light. PDT is effective for oncologic applications. Many cancer patients have undergone a hematoporphyrin derivative (HpD)-mediated PDT. The HpD showed a side effect causing prolonged cutaneous photosensitivity. But ATX-S10, a new photosensitizer, provides rapid plasma and tissue clearance, comparable photoactivation efficiency, and superior light absorption of visible red. In this study, the tumor rejection mechanisms of PDT using ATX-S10 on HeLa tumors in nude mice were investigated with morphological and fluorometric methods. The mice were intracutaneously inoculated with HeLa cells, 5 x 10(5) or 1 x 10(7) cells. When tumors grew to about 10-12 mm in diameter, mice were intraperitoneally administered ATX-S10, 30 mg/kg, and 2 hours later the ATX-S10 in tumors was indirectly measured by a fluorometric machine, PMA-10 (Hamamatsu Photonics K. K.) and the tumors were irradiated by Optical Parametric Oscillator (Hamamatsu Photonics K. K.) tuned to a wave length at 670 nm, 5 mJ/pulse, 100 J/tumor. Before and after the irradiation, the effective mechanisms of PDT with ATX-S10 were studied by histological and ultrastructural approaches. The results showed occlusive thrombi in the microvasculature of the tumors and tumor cell death. These occlusive thrombi were observed within one hour after PDT at both light and electron microscopy levels, and were more remarkable as time passed after PDT. Therefore, the morphological studies of PDT with ATX-S10 suggested that the rejection mechanisms occurred mainly as a result of the destructive changes of the microvasculature in the tumors first, and secondly or simultaneously, tumor cells were destroyed through necrosis, and finally the tumors were rejected.

Staining of the lens capsule for circular continuous capsulorrhexis in eyes with white cataract

We have developed a technique of staining the anterior capsule with a solution of indocyanine green that facilitates performance of the circular continuous capsulorrhexis in eyes with a mature cataract. We compared the results of phacoemulsification and intraocular lens implantation in 10 eyes with the capsule stained with results of 10 eyes having the same procedure with standard circular continuous capsulorrhexis. The results of specular microscopy and laser flare-cell photometry showed no statistically significant differences between the 2 groups. Although the safety of intraocular indocyanine green dye has not yet been definitively established, the findings of this pilot study suggest that it is safe and useful in visualizing the anterior capsule of a mature cataract during cataract surgery.

Assay method for femtogram order of Ca2+, Mg(2+)-dependent endonuclease

A sensitive method for the assay of Ca2+, Mg(2+)-dependent endonuclease was developed. The assay procedure is composed of two parts: (i) microscale endonuclease digestion of highly polymerized calf thymus DNA and (ii) the quantification of DNA breaks by measuring the activation of poly(ADP-ribose) polymerase, which is known to be activated proportionally to the number of nicks and ends of DNA added in the reaction mixture. This method was approximately 10(5)-fold more sensitive than a conventional DNase assay detecting acid-soluble DNA formation and, thus, the activity of 20 to 100 fg of purified bull seminal Ca2+, Mg(2+)-dependent endonuclease could be reliably measured. Ca2+ and Mg2+ requirements and the response to histone H2B of the endonuclease were also demonstrated by this method. Using this method, the assay of a very small amounts of Ca2+, Mg(2+)-dependent endonuclease in crude extracts of calf thymus chromatin was possible. This method may be applied to other types of endonucleases by modifying the mixture for endonuclease reaction.

Orthotopic vascularized osteochondral allografts in an immunosuppressed rat model

This study examined the survival of orthotopic, vascularized, osteochondral allografts, following 12 weeks of immunosuppression and transfer into a naive, allograft host up to 14 weeks later, and compared the results with those previously reported for similar grafts in a heterotopic position. Knee-joint allografts between DA (donor) and Lewis (recipient) rat strains were assessed by quantitative histology up to 6 months after transplantation, and graft microcirculation was examined by India-ink infusion. Graft repopulation was assessed by re-transferring the graft to a naive, non-suppressed allograft host 12 to 26 weeks after the initial transplantation. Isografts survived for as long as grafts were examined (6 months) and showed good healing of the graft/host bone junction, although long-term isografts showed some deterioration of the growth plate. Non-suppressed allografts rejected within 2 weeks. Allografts in hosts immunosuppressed for 12 weeks remained healthy and healed in a similar manner to the isografts. Following cessation of immunosuppression, allografts progressively deteriorated, with mononuclear cell infiltration apparent in graft bone marrow and muscle in the later stages examined. Transfer to second non-suppressed hosts resulted in rapid rejection of the allografts, indicating that, as shown previously in heterotopic, osteochondral allografts, little or no graft repopulation by host-derived cells had occurred during the protected period in the first host.

Reappraisal of the systematic management of complicated hepatolithiasis with bilateral intrahepatic biliary strictures

OBJECTIVE

To compare the results, limitations, and complications of the surgical treatment of bilateral hepatolithiasis and intrahepatic biliary strictures with left hepatectomy and without left hepatectomy.

DESIGN

Case-controlled study.

SETTING

Referral center.

PATIENTS

During a 12-year period, 103 patients with bilateral hepatolithiasis and intrahepatic biliary strictures underwent surgical treatment. Group A (n = 73) received left hepatic resection (lateral segmentectomy or lobectomy) and postoperative biliary dilatation with residual stone extraction. Group B (n = 30) underwent the same procedures except for left hepatectomy.

INTERVENTIONS

Left lateral segmentectomy or left lobectomy, choledocholithotomy, postoperative cholangioscopic treatments (electrohydraulic lithotripsy, other lithotripsy, lithotomy, balloon dilatation, etc. via T tube or precutaneous transhepatic route).

MAIN OUTCOME MEASURES

Days of hospitalization, incidence of major and minor complications, mortality rates, and the rates of residual stones and stone recurrence were compared.

RESULTS

Group A and B had similarly low postoperative 1-month mortality rates of 5.5% and 6.7%, respectively. The main cause of death in both groups was uncontrollable septicemia. The main major complications in group A were intra-abdominal abscess and upper gastrointestinal bleeding; the major complication in group B was massive hemobilia. Group B had a significantly higher overall rate of complications (53.3% vs 23.3%, P < .01) and a longer hospital stay than group A (median, 72 days vs 28 days, P < .03). When complications were classified as major or minor, only minor complications showed a significant difference (30% vs 13.7%, P = .05). After using biliary stricture dilatation and stone extraction, the rate of residual stones in the right lobe was similar in both groups, but patients in group B had a significantly higher rate of residual stones (12.5% vs 0%, P < .02) and stone recurrence in the left lobe (19% vs 0%, P < .003) than those in group A.

CONCLUSIONS

Partial resection of the left lobe in cases of bilateral hepatolithiasis and biliary strictures can effectively simplify problems in the treatment of bilateral hepatolithiasis and intrahepatic biliary strictures. In addition, not only were surgical complications not increased, but a decrease in complications from postoperative manipulations for stone clearance was noted in our series.

Effects of the dopamine-related drug bromocriptine on event-related potentials and its relation to the law of initial value

Effects of the dopamine-related drug bromocriptine (BCT) on event-related potentials (ERP) were investigated in 18 healthy volunteers. Bromocriptine 2.5 mg or an inactive placebo was administered according to a completely randomized double-blind, cross-over design. The ERP were recorded 3 h after medication was given. Although BCT prolonged the P300 latency, it had no effect on the amplitudes of the ERP components as a whole. Bromocriptine increased the latencies of N100, P200 and P300 in the respective short-latency subject group, and decreased the latency of N200 in the long-latency subject group. It increased the amplitude of N200 in the low-amplitude subject group. It was concluded that the prolongation of P300 latency as a whole and the different responses that take place are dependent on the initial values and were recognized in the effect of a single administration of BCT 2.5 mg. The results of this study are discussed in relation to the law of initial value.

Coexisting sharp ductal angulation with intrahepatic biliary strictures in right hepatolithiasis

OBJECTIVE

To investigate the clinical characteristics of a coexisting sharp ductal angulation (< 90 degrees) with biliary stricture and to evaluate the difficulties it imposes in the management of retained or recurrent hepatolithiasis.

DESIGN

Case-controlled study.

SETTING

A referral center.

PATIENTS

Eighteen consecutive patients having right-sided hepatolithiasis and a coexisting sharp ductal angulation associated with biliary stricture (group 1) were compared with 84 patients matched with sex, age, and conditions of hepatolithiasis and intrahepatic biliary stricture(s) but no sharp angulated duct (group 2).

INTERVENTION

Postoperative cholangioscopic management (electrohydraulic lithotripsy or other lithotripsy, lithotomy, balloon dilation, biopsy, etc, via T-tube tract or percutaneous transhepatic route).

MAIN OUTCOME MEASURES

Sessions of manipulations, incidence of complications associated with interventions or disease, and mortality were compared.

RESULTS

Patients of group 1 needed more sessions of postoperative manipulation of stones and strictures (13.7 +/- 4.2 vs 8.0 +/- 2.3; P < .001). During management, there was a significantly increased vulnerability of severe and/or recurrent cholangitis (66.7% vs 9.5%; P < .001), septic shock (77.8% vs 11.9%; P < .001), liver abscess (55.6% vs 7.1%; P < .001), or massive hemobilia (33.3% vs 7.4%) in group 1 than in group 2. Their risks of coexisting secondary biliary cirrhosis (55.6% vs 9.5%; P < .001) and/or cholangiocarcinoma (16.6% vs 2.4%; P < .04) and mortality (27.8% vs 4.8%; P < .01) were also significantly higher in group 1.

CONCLUSION

Our results suggest that the coexisting sharp ductal angulation with biliary strictures in right-sided hepatolithiasis is a distinct difficult clinical entity in the field of biliary tract calculi.

Vascularized heterotopic osteochondral allografts in a rat model following long-term immunosuppression

The effect of 12 weeks of cyclosporin A (CyA) (7 mg/kg) on the survival of vascularized osteochondral allografts between rat strains--Dark Agouti (DA donor) and Lewis (recipient)--was examined up to 6 months after grafting. Grafts were assessed by India-ink infusion to examine their microcirculation, and by quantitative histology. Isografts (Lewis to Lewis) survived at least 25 weeks, but displayed progressive deterioration due to their non-weight bearing position. Rejection controls (allografts with no immunosuppression) showed rejection within 2 weeks. Allografts in immunosuppressed hosts remained healthy for the 12-week period of immunosuppression, but deteriorated progressively during the ensuing 14 weeks, particularly in the muscle, marrow, and growth plates. Graft repopulation by host cells was assessed by transferring grafts into fresh non-suppressed allograft hosts, following 12 to 26 weeks in the first, immunosuppressed host. All grafts were rejected rapidly following the second transfer, indicating that little or no cellular repopulation of the graft had occurred while in the first host.

Alteration of immunoreactivity by hydrated autoclaving, microwave treatment, and simple heating of paraffin-embedded tissue sections

The effects of treatment in a hydrated autoclave (121 degrees C, 2 atm for 20 min), microwave oven (in water), and simple heating (60 degrees C overnight in distilled water or 90 degrees C for 10 min in ZnSO4) on the stainability of 56 antigens by commercially available antibodies in formalin-fixed paraffin-embedded tissue sections were evaluated. The detectability of nuclear antigens, glycoprotein, lymphocytic surface markers, and chromogranin A was significantly and reproducibly improved by these treatments, whereas the detectability of viral antigens and peptide hormones was attenuated or unchanged. This enhancement includes not only the distinctiveness of the positive staining, but also the number of positive cells, as revealed by comparing serial sections. Among these four heating procedures, microwave heating and autoclaving were more effective than the others on p53, c-erbB-2, and CA125, whereas simple heating was best for smooth-muscle actin (HHF35 and CGA7). Generally the effects of the heating procedures for these antigens were consistent among the cases, but the effects on GFAP varied with the case. The alterations we observed could significantly influence the interpretation of immunohistochemical staining of currently popular tumor markers such as p53 in terms of their prevalence (28% vs 64% in gastric cancer; 36% vs 82% in metastatic liver cancer) and other diagnostically important markers.

A histochemical study of the biceps brachii muscle cross-innervated by intercostal nerves. 6 cases of brachial plexus injuries operated with nerve-crossing

Direct nerve-crossing of intercostal nerves from the lateral thorax to the musculocutaneous nerve was performed in 6 patients after spinal nerve root avulsion with brachial plexus palsy. Elbow flexion power was regained well enough to move against gravity and some resistance in all cases. The muscles were examined histochemically 4 (1-9) years after the operation. The intercostally-innervated biceps brachii muscle showed motor predominance of slow-twitch Type 1 fiber regeneration much more than that of fast-twitch Type 2 fiber in 5 of our patients. Our study suggests that the motor nerves of slow-twitch fibers may have priority in peripheral nerve regeneration over those of fast-twitch fibers.

Correlation between event-related potentials and MR measurements in chronic alcoholic patients

Event-related potentials were recorded in 25 abstinent alcoholics, and 25 gender- and age-matched controls during a two-tone discrimination (odd ball) task. All the subjects were free from medication and dextral. MR images were examined in the alcoholics. The amplitudes of N100, N200 and P300 in the alcoholics were reduced compared with those of the controls. In order to identify morphological changes responsible for ERP abnormalities, linear regression analyses were performed between ERP measures and MRI parameters. The amplitude of N100 was inversely correlated with ventricular size. The amplitudes of P300 were inversely correlated with both ventricular size and width of cortical sulci. It was suggested that the N100 abnormality was related to subcortical structure, and P300 alteration was related to both subcortical and cortical structures in the alcoholics.

[The difference between right and left in vitreous findings of normal eyes]

The vitreous in both normal eyes of 671 normal subjects was studied biomicroscopically. The results obtained were as follows: 1. In 618 cases of a refractive error less than -3D (group A) and 53 cases of refractive error over -3D (group B), the incidence of posterior vitreous detachment (PVD) in both eyes increased with age and the absence of PVD in both eyes decreased with age. The percentage of cases with PVD in one eye and no PVD in the other eye was less than 22% in all age groups. 2. There was no significant difference in the degree of vitreous liquefaction between the right and the left eyes. The degree of vitreous liquefaction was also age-related. 3. In the cases with PVD in one eye and no PVD in the other eye, a higher incidence of mild vitreous liquefaction was found in group A than in group B. 4. PVD without collapsed vitreous (simple PVD) in both eyes was observed only in group A. 5. Our results indicated that the vitreous findings in both eyes of an individual were almost identical, and PVD may occur with less vitreous liquefaction in group A than in group B.

Non-surgical retrieval of intravascular foreign body: experience of 12 cases

An intravascular foreign body is an iatrogenic complication that occurs during arterial or venous catheterization or interventional procedures. The foreign body could either be a catheter fragment, a dislodged coil, or a steel guide wire. From January 1987 to December 1992, 12 cases of intravascular foreign-body removals were performed by a percutaneous method at Mackay Memorial Hospital. Of the 12 cases, five were dislodged steel guide wires, four were broken CVP catheters, two were dislodged coils, and one was Port-A fragment. The techniques we used were the loop-snare technique (two cases) and stone basket retriever (10 cases). Eleven cases of intravascular foreign bodies were removed by non-surgical percutaneous retrieval but one case was a failure due to improper extraction of a dislodged steel guide wire. The patient received surgical extraction by regional venotomy finally. No major complications were noted during or after these procedures.

Heterotopic vascularized growth plate transfer in juvenile dogs

Prior animal studies of vascularized epiphyseal transfers placed growth plates in 2 bone systems where the independent growth of epiphyses and their response to altered stresses has been difficult to assess. This study assessed growth of vascularized ulnar epiphyses transferred to the ipsilateral humerus of 12-week-old puppies. Growth was permitted by a specially designed extensible plate. Control groups showed that humeral dissection, osteotomy and ostectomy alone do not stimulate growth. In 4 puppies initial growth of the transferred epiphysis was seen but late collapse and formation of bridging callus occurred so that overall humeral length at maturity was not significantly different from control humeri. Physical forces inherent in heterotopic transfer may preclude long term growth of transferred epiphyses particularly in sites of higher relative load. The extensible plate used here may be a useful device in the fixation of transferred epiphyses with growth potential.