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Heterobothrium okamotoi, a monogenean gill parasite, exhibits high host specificity for the tiger puffer, Takifugu rubripes, and it has been experimentally verified that the parasite cannot colonize either closely related species such as the grass puffer Takifugu niphobles or distantly related fish such as the red seabream Pagrus major. Previously, we demonstrated in T. rubripes that immunoglobulin M (IgM) with d-mannose affinity induced deciliation of the oncomiracidia, the first step of parasitism, indicating that the parasite utilizes the molecule as a receptor for infection. In the present study, we purified mannose-specific IgM from 2 nonhost species, T. niphobles and P. major, by affinity and gel-filtration chromatography techniques and compared their deciliation-inducing activity against H. okamotoi oncomiracidia. The IgM of the former showed activity, whereas the latter had no effect, suggesting that in addition to d-mannose-binding ability, the crystallizable fragment domain of IgM, which is not part of the antigen-binding domain, plays an important role in host recognition by the oncomiracidia, such as direct binding to the parasites. It also suggests that the host specificity of H. okamotoi is relatively low upon initial recognition, and the specificity is established by exclusion in nonhosts during a later stage.

Since the start of the severe accidents at the Fukushima Daiichi Nuclear Power Plant in March 2011, concrete surfaces within the reactor buildings (RBs) have been exposed to radioactive contaminant...

In Japan, the density of Japanese tree frogs (Hyla japonica) may not be necessary high in traditional rice fields compared to modern fields because the modernization of drainage systems from shallow earthen ditches to deep concrete-line ones reduces the abundance of predators/competitors for tadpoles, such as dojo loach (Misgurnus anguillicaudatus). This hypothesis was tested using two approaches. First, laboratory experiments revealed that the presence of the loach significantly reduced the survival of tree frog eggs and tadpoles. Second, observational studies in rice fields showed that the direct effect of modernization on tadpoles was not significant but the indirect (and thus total) effects were weakly positive due to the reduction in the density of dojo loach. Our study suggests that recent agricultural intensification in rice fields does not negatively impact all aquatic species but that some species may not be affected or can even flourish by having tolerance for the changes and release from potential predators or competitors.

In this paper, we describe a new type of scintillation detector that can be inserted into long, narrow tubes used in nuclear power plants to measure radioactive contamination of their inner surfaces. The sensitive area of the detector needs to cover the entire circumference and extend along the longitudinal axis, and its performance must be equivalent to that of a conventional survey meter. To construct such a sensitive area, we bonded six long, thin plastic scintillator strips around a hexagonal center core. For the hexagonal center core, we proposed a novel light collection structure called a "composite light guide," using a wavelength-shifting technique to maintain the counting efficiency while achieving better uniformity along the longitudinal axis. We conducted basic experiments, and also established a simple light propagation model of the composite light guide, focusing on the light intensity, and confirmed its effectiveness. Using this light propagation model, we determined the optimum design and incorporated it into the manufacture of a prototype detector. From tests of the prototype detector, we verified that its performance satisfied the design requirements and that the composite light guide functioned effectively.

Nuclear waste contains a significant amount of long-lived non-gamma-emitting nuclei such as 129 I and 14 C. A method of nondestructive detection for monitoring long-lived waste products is proposed as an application of the (y, n) reaction. This method is useful for surveying long-lived "difficult-to-measure" nuclides, e.g., 129 I. Iodine-128 produced from the reaction of 129 I(γ, n) 128 I emits gamma rays that can easily be measured by a gamma-ray counter. We measured the inclusive photonuclear 129 I(γ, n) 128 I reaction cross section induced by bremsstrahlung photons. The photons were produced at a Ta target bombarded by 30-MeV electrons from a linear accelerator. The intensity of the slow neutrons was considered in the reactions of 127 I(n, γ) 128 I and 129 I(n, γ) 13 °1. The activity of 128 I was measured by a high-purity germanium spectrometer. The gamma-ray flux and the neutron flux were calculated using the EGS and MCNP codes, respectively. The average activation cross section of the 129 I(γ, n ) 128 I reaction had a 12% deviation from the evaluated International Atomic Energy Agency photonuclear data.

Many long-lived non-gamma emitting radioactive nuclei such as 129I, 14C and 93Zr are produced as wastes from nuclear fuel cycle facilities. They are called “difficult-to-measure” radio nuclei. Among them 129I is a long-lived β-emitting isotope with a half-life of 1.57 × 107 years. Iodine compounds are mobile in the vadose zone and groundwater and increase a significant long-term risk. Transmutation of 129I is a challenging issue in nuclear waste management and disposal. If 129I is transmuted into 128I (half life; 25 minutes), it can easily be measured by a Ge detector. However, the 129I(γ, n) reaction cross section has not been measured so far. In this study we have measured the inclusive 129I(y, n)128I cross section by using bremsstrahlung photons. The bremsstrahlung photons were produced from a 30-MeV electron linac. Measured average activation cross section agrees with 12% deviation from the evaluated one in the IAEA photonuclear data library. Gamma and neutron fluxes for the (γ, n) and the (n, γ) reac...

Caveolin-1, a principal component of caveolae, modulates growth signaling, endocytosis, and intracellular transport. We examined the expression of caveolin-1alpha and its relation to cell cycle and caveolin-interacting growth factor receptors in regenerating proximal tubules (PTs) after gentamicin-induced acute renal failure in rats. Caveolin-1alpha appeared in regenerating PTs as early as day 4 after last gentamicin, peaked at days 6 to 8, and showed cytoplasmic pattern after day 8. Immunoelectron microscopy revealed caveolin-1alpha-positive caveolae on the cell membrane and in cytoplasms in regenerating PTs at days 4 to 8 and caveolin-positivity confined to cytoplasms after day 10. The number of PT cells with proliferation markers peaked at day 6 and decreased afterwards as expression of cyclin-dependent kinase inhibitors increased. Platelet-derived growth factor receptor-beta (PDGFR-beta) and epidermal growth factor receptor (EGFR) were colocalized with caveolin-1alpha in proliferating PTs as early as day 4. Phosphorylated EGFR increased at day 8 and afterwards when caveolins dissociated from EGFR or decreased. In case of PDGFR-beta, phosphorylation seemed to be associated with the increase and association of caveolins to the receptors. Our results suggest that transient expression of caveolin-1alpha in early regenerating PTs might contribute to the regenerating process of PTs through modulating growth factor receptors.

Populations of spider mites were sampled from kudzu vine Pueraria lobata (Willd.) from 1997 to 1999 at two study sites in Ibaraki, central Japan. Of the five spider mite species sampled, Tetranychus pueraricola Ehara and Gotoh was the most abundant (accounting for 75.6–96.9% of mites) in each of the three years. The next most abundant species were T. ludeni Zacher (0.8–19.0%), T. parakanzawai Ehara (1.1–9.7%) and T. piercei McGregor (3.1%), but their density and species richness varied from year to year and from site to site. The populations peaked in June and/or September–October. Predators associated with spider mite populations were phytoseiid mites such as Amblyseius tsugawai Ehara, Phytoseius nipponicus Ehara and Neoseiulus womersleyi (Schicha), Scolothrips takahashii Priesner, Oligota spp., Feltiella spp. and stigmaeid mites such as Agistemus exsertus Gonzalez and A. terminalis (Quayle), which were well synchronized with spider mite density. Overwintered females began to appear and oviposit on some herbaceous weeds growing at the study sites in early April. Spider mites appeared on kudzu vine leaves in early May just after flushing. Most colonies (defined as areas surrounded with silky spider mite threads) had only one species but a small percentage had two or three species.

Background We examined kinetics and characterization of regenerating proximal tubule (PT) cells after various degrees of tubular injury in S3 segments of PT and assessed label-retaining slow cycling cells in S3. Methods PT injury was induced by different doses of uranyl acetate (UA) injection into rats, and initially regenerating PTs were identified by in vivo bromodeoxyuridine (BrdU)-labelling before sacrifice or were examined on vimentin positivity. Next, the 3H-thymidine pulse/chase approach was applied to the early regenerating PTs identified by BrdU-labelling after UA injection. Results Low-dose UA induced focal PT depletion and initial BrdU positivity in the proximal three-quarters of the S3 segment of PT. Autoradiography showed the increased number of label-retaining and label-diluted cells in the proximal three-quarters of S3 in rats treated with low-dose UA compared to normal rats. High-dose UA induced almost complete PT depletion in the proximal three-quarters of S3 and less PT depletion in the distal quarter of S3 and initial BrdU+ cells were restrictedly found in the distal quarter of S3. Label-retaining and label-diluted cells were increasingly found in the entire S3 at day 7, but only label-retaining cells remained in similar numbers in the distal quarter of S3 until day 42. Initially regenerating PT cells with any doses of UA expressed vimentin, suggesting dedifferentiated PT cells. Conclusions Initially regenerating cells after PT injury in S3 are dedifferentiated pre-existing PT cells, which may scatter throughout S3 and be responsible for focal repair of S3. Some initially regenerating PT cells in the distal S3 showed persistent label-retaining cells at day 42 after high-dose UA insult and contributed to renewal of the entire S3, thus they might be slow cycling cells with responsibility for S3 repair.

A 57-year-old woman was admitted because of severe bradycardia and hypotension caused by an anti-arrhythmic agent and beta-blocker. For 19 months before admission, she had been undergoing hemodialysis with an F8-HPS polysulfone membrane hemodialyzer without any complications. In 2 dialysis sessions after admission, when a BS polysulfone membrane was used, she experienced anaphylactoid shock with severe hypotension leading to syncope, dyspnea and vomiting, just after the start of hemodialysis. After the anaphylactoid shock, her dialyzer membrane was changed to a cellulose triacetate membrane and she did not suffer from such attacks. This case indicates that severe anaphylactoid shock may be caused by a biocompatible dialyzer membrane and that the reactions of patients to each polysulfone membrane may differ among polysulfone membranes made by different manufacturers.

We recently reported that transient appearance of interstitial myofibroblasts and infiltrating macrophages might play a role in cellular recovery in uranyl acetate (UA)-induced acute renal failure (ARF). Here we tested the effects of mycophenolate mofetil (MMF), which attenuates infiltration of lymphocytes, macrophages, and myofibroblasts, but does not suppress epithelial regeneration, on renal tissue repair. Rats treated with MMF (20 mg/kg/day) or vehicle were sacrificed at 2, 5, and 7 days after induction of ARF by injection of 5 mg/kg UA. Renal tissues were immunostained for bromodeoxyuridine (BrdU) and Ki67, alpha-smooth muscle actin (alpha-SMA), ED1, and CD43. The expression levels of alpha-SMA mRNA were examined by reverse transcription-polymerase chain reaction. Body weight loss or serum albumin levels were similar in MMF and vehicle rats during the experiment. In vehicle group, serum creatinine (Scr) significantly increased after day 5, but proximal tubular (PT) damage score increased as early as day 2 after UA injection. BrdU- or Ki67-positive regenerating tubular cells, ED1-positive macrophages and alpha-SMA-positive myofibroblasts significantly increased in the interstitium after day 5. In MMF-treated rats, Scr and PT damage score significantly increased at day 7 and the number of regenerating PT were significantly reduced compared with vehicle-treated rats at days 5 and 7. The numbers of macrophages and myofibroblasts and the expression of alpha-SMA mRNA were significantly lower in MMF than in vehicle rats at day 5, indicating that reduced interstitial cellular response is linked to the inhibition of regenerative repair. CD43-positive lymphocytes were significantly reduced in MMF group than in vehicle group at day 7, suggesting that lymphocyte infiltration does not seem to contribute to early regenerative response of proximal tubules. The transient appearance of myofibroblasts and macrophages in the interstitium may promote regenerative repair in UA-induced ARF in rats.

Background: We investigated the mechanisms and kinetics of Bowman’s epithelial-myofibroblast transdifferentiation in the formation of glomerular crescents. Methods: Crescentic glomerulonephritis was induced by i.v. injection of rabbit anti-rat glomerular basement membrane antiserum in WKY rats. Results: Cellular crescents (83.5% of glomeruli) were first observed at day 7 after disease induction. Immunostaining of alpha-smooth muscle actin (alpha-SMA), as a marker for the myofibroblast phenotype, was found in some periglomerular regions as early as day 3, when it was also seen in parietal epithelial cells (PEC) of Bowman’s capsule at day 5 and in crescent formation at day 7. Proliferation marker Ki67-positive PEC was found at day 3, and double Ki67- and alpha-SMA-positive PEC could be seen at day 5. The migratory figure of PEC with the expression of alpha-SMA was found by immunoelectron microscopy. At day 7, some crescent cells were stained positive for PEC marker, protein gene product 9.5, in association with alpha-SMA or Ki67. Expression of transforming growth factor (TGF)-β receptor types I and II, as well as platelet-derived growth factor (PDGF) receptor β and PDGF-B increased in PEC as early as day 3. At day 5 marked deposition of cellular and common fibronectin, but not other extracellular matrix components examined was found in Bowman’s spaces where ED 1-positive macrophages infiltrated. Conclusions: PEC may be stimulated to proliferate and/or transdifferentiate into myofibroblast phenotype possibly by action of TGF-β and PDGF and/or binding of fibronectin to PEC, then migrate and/or proliferate, participating in glomerular crescents.

The prognosis of renal cholesterol crystal embolism (CCE) is poor, and many patients progressively develop to the end-stage of chronic renal failure. We herein experienced a 66-year-old male patient who recovered from hemodialysis (HD) shortly after an amputation of inflammatory toes. The patient complained of painful digital cyanosis at bilateral toes and livedo reticularis at right lower leg 4 weeks following aortic angiography. Laboratory examinations revealed eosinophilia and overt proteinuria (3.0 g/day). His serum creatinine level increased from 2.18 to 8.57 mg/dl over 6 weeks, and HD treatment was started. Treatment with simvastatin (5 mg/day) did not reverse renal failure and hypereosinophilia, but the amputation of right gangrene toes promptly increased urine output and eosinophilia completely disappeared concomitantly with a decline of C-reactive protein from 9.7 to 0.7 mg/dl. Serum creatinine level was also reduced to 3.46 mg/dl, and he eventually stopped HD totally after 32 sessions. This case suggested that the surgical amputation promptly recovered renal function. Reversal of inflammation may be more effective than lipid-lowering therapy for renal failure in our patient.

Long-life non-γ emitting radioactive wastes such as 129 Iand 14 C are produced from nuclear waste facilities. The photonuclear reaction is supposed to be usable for measuring the quantity of such nuclides without destruction of waste drum. Photonuclear products of 128 Ia nd 13 C emit gamma rays and their radiation can be easily detected by a Ge detector. In this study, the inclusive photonuclear reaction cross section of 129 I(γ,n) 128 I was measured by the use of bremsstrahlung photons from 30-MeV electron LINAC. The amount of produced 128 I was measured with an HPGe gamma-ray spectrometer. Experiments were analyzed for both (γ,n) and accompanying (n,γ) reactions. Flux calculations were performed by EGS and MCNP codes. The measured average activation cross section of 129 I(γ,n) 128 I is 0.096 ± 0.005 barn on the basis of 197 Au(γ,n) reaction value. The measured value agrees with the evaluated (IAEA photonuclear data library) cross section within a deviation of 17%. The cross section is usable for non-destructive measurement of the amount of 129 I in radioactive waste.

To investigate the mechanisms of myofibroblast differentiation of interstitial fibroblastic cells (FCs) in rats with uranyl acetate-induced acute renal failure (ARF), we examined the relationship between the expression of alpha-smooth muscle actin (alpha-SMA), myofibroblast phenotype and tubular dilatation as well as cell shape and adhesion of FCs. Peritubular alpha-SMA-positive myofibroblasts appeared after induction of ARF and extended along the damaged, dilated proximal tubules and then almost disappeared after proximal tubular recovery. The perimeter of proximal tubules correlated with fractional areas stained for alpha-SMA (P0.001). Most alpha-SMA-positive cells did not incorporate [3H]-thymidine, indicating a low proliferative activity. Transmission electron microscopy showed that FCs increasingly attached to the tubular basement membrane by elongated cytoplasm-containing microfilament bundles, which formed abundant adherens and gap junctions from day 4 to day 7. Scanning electron microscopy showed hypertrophic FCs covering large areas of tubules after induction of ARF. Administration of chlorpromazine, which can inhibit cytoskeletal movement, after induction of ARF partially inhibited myofibroblast differentiation of FCs immunohistochemically and morphologically and resulted in more dilated proximal tubules in concert with aggravation of renal dysfunction and inhibition of regenerative repair at day 4 than vehicle-administered rats. Our results indicate that mechanical tension, judged by tubular dilatation, may contribute to the induction of alpha-SMA phenotype with increased stress fiber formation and intercellular junctions in FCs to support damaged nephron structures by adjusting tensional homeostasis in rats with uranyl acetate-induced ARF.

Microvascular hyperpermeability to plasma proteins via vascular endothelial growth factor (VEGF) with endothelial nitric oxide synthase (eNOS) induction may contribute to wound healing through matrix remodeling. However, vascular hyperpermeability is not examined in acute renal failure (ARF), a unique form of wound healing. Subcutaneous injection of gentamicin (400 mg/kg per day for 2 days in divided doses every 8 h) in rats increased serum creatinine levels and induced tubular damage, which peaked at day 6, after the last gentamicin injection. Ki67-positive regenerating proximal tubules (PTs) peaked in number at day 6 and almost covered the bare tubular basement membrane (TBM) by day 10. Staining of fibrinogen and plasma fibronectin began to increase in the peritubular regions as early as day 0, steadily increased in TBM and tubular lumen until day 6 and then decreased. Hyperpermeable peritubular capillaries were identified by extravasation of perfused-fluoresceinated dextran (both 70 kDa and 250 kDa) into peritubular regions as early as day 0 and prominently into TBM and tubular lumen at day 6. Electron microscopy further suggested the intraendothelial pathway of dextran. Immunoreactive VEGF increased in the damaged and regenerating PTs. Immunoreactive VEGF receptors-1 and -2 did not change, but immunoreactive eNOS increased in the peritubular capillaries after induction of ARF. Western blotting for VEGF and eNOS supported the immunostaining findings. In addition, we assessed the effects of NOS inhibitor N-nitro-L-arginine methyl ester (L-NAME) on vascular hyperpermeability during the recovery phase of this model. Treatment with L-NAME (s.c. at a dose of 100 mg/kg/day from day 3 to day 6) decreased extravasation of perfused-250-kDa dextran and significantly inhibited the regenerative repair of PTs at day 6 when compared with vehicle-treated rats. In conclusion, plasma protein extravasation occurred, leading to matrix remodeling, such as the process of wound healing during the tubular repair in gentamicin-induced ARF. Since VEGF-induced vascular hyperpermeability may depend on NO production, VEGF/VEGF receptor system with eNOS induction might be responsible for this process.

The present study was designed to asses the dynamic changes in macrophages (Møs) with or without expression of major histocompatibility complex (MHC) class-II molecule in response to uranyl acetate-induced acute renal failure (ARF) in rats. ED1+ monocytes/Møs infiltrated into the interstitium as early as day 2, peaked in number on day 5 after uranyl acetate-induced ARF. ED1+ cells did not correlate with necrotic tubules but accumulated abundantly in the vicinity of the Ki67+ regenerating proximal tubules around days 4-5. Afterward, regeneration of proximal tubules was accelerated. After day 5, some ED1+ cells entered the tubular lumen, and became ED1+ giant cells, which had features of phagocytic Møs by immunoelectron microscopy, peaking in number on day 7. Most ED1+ cells did not incorporate [(3)H]-thymidine, indicating lack of active proliferation. The number of OX6+ cells (directed to MHC class-II molecule) in the interstitium significantly increased on day 4 and peaked on day 5. Double staining revealed that ED1+OX6- cells entered the tubular lumen while ED1+OX6+ cells remained in the peritubular regions. Osteopontin (OPN) protein and mRNA were significantly upregulated. No specific relationship could be found between OPN+ regenerating proximal tubules and ED1+ cells, but most ED1+ giant cells were OPN+ and intermingled among OPN+ cell debris. Our findings suggest that ED1+ Møs are actively associated with regenerating proximal tubules and, thus, might promote proximal tubular regeneration. ED1+OX6- Møs may function as scavengers and phagocytose cellular debris in the tubular lumen, cleaning the wound site. OPN might be involved in this process. ED1+OX6+ Møs in the peritubular regions may act as outpost of the defense system to monitor incoming antigens. Our data indicate that Møs with or without expressing MHC class-II molecule contribute to the defense and repair of injured proximal tubules in this ARF.

We describe a 59-year-old man with nephrotic syndrome that was diagnosed as suspected minimal change nephrotic syndrome by the routine examination of renal tissues at first biopsy, because renal histology showed segmental mild mesangial expansion with argyrophilic staining and partial foot process fusion without any deposition. Prednisolone therapy induced complete remission of nephrotic syndrome. Relapse occurred after 4 years of complete remission, and the second renal biopsy revealed amyloid light-chain (AL)-amyloidosis. Re-examination of the first biopsy tissues by Congo red staining confirmed a small amount of amyloid deposition in the mesangial areas although the mesangial areas showed argyrophilic staining, which is atypical for amyloid deposition. This case raises a caution that even when renal histology is not suggestive of amyloidosis and prednisolone therapy is very effective, when a renal histology diagnosis is not confirmed, the clinician should suspect amyloidosis and should, at least, undertake Congo red staining to definitively rule out amyloidosis.

Aims: To elucidate the pathophysiological roles of the changes of distal nephron in uranyl acetate (UA)-induced acute renal failure (ARF), we investigated the relation of changes of constituent molecules in distal nephron to proximal tubular damage and repair in UA-treated rats. Methods: ARF was induced in rats by intravenous injection of UA, and all rats received bromodeoxyuridine (BrdU) intraperitoneally 1 h before sacrifice. Results: Proximal tubular damage with necrosis appeared as early as day 2, mainly in the outer stripe of outer medulla and reached a peak level at day 5. Slight cellular damage was evident in the distal nephron as early as day 3, reaching a peak level around day 9. Immunoreactive BrdU- or vimentin-positive regenerating proximal tubules (PT) appeared at day 2 and regenerating PT relining was almost completed by day 7. Immunostaining for EGF, which was constitutively expressed in the thick ascending limb (TAL) and distal convoluted tubule (DCT), diminished significantly as early as day 2, when PT regeneration became evident, and remained below normal levels until day 21. In contrast, slight immunoreactivity for EGF was observed in regenerated PT accompanying brush-border formation mainly after day 9, suggesting newly expressed EGF might contribute to PT maturation. Lectin staining or immunostaining for representative constituent molecules of the thin descending limb, TAL, DCT and collecting duct demonstrated marked and transient reduction after day 5. Conclusions: EGF was not associated with regenerating PT, but may be involved in the maturation of PT. Transient reduction in expression of constituent molecules of the distal nephron following the reduction in EGF could reflect dedifferentiation or phenotypic simplification during regenerative repair of PT in UA-induced ARF in rats.

A 47-year-old Japanese woman undergoing maintenance hemodialysis (HD) was admitted to our hospital because of poisoning with the herbicide bialaphos. Respiratory arrest and loss of consciousness ensued rapidly, accompanied by convulsions and nystagmus. Treatment with HD and direct hemoperfusion, followed by HD alone, effectively removed bialaphos and its chief toxic metabolite (L-AMPB) from the circulation (bialaphos decreased from 0.33 to0.05 microg/ml and L-AMPB from 14 to 0.86 microg/ml). The glutamate concentration improved gradually after the removal of bialaphos and L-AMPB from plasma (plasma glutamate concentration: 250.4 nmol/l on day 5 to 120.6 nmol/l on day 26). Decreased glutamine concentration in cerebrospinal fluid was demonstrated for the first time as well as in plasma, indicating glutamine synthetase inhibition not only in plants but also in humans by bialaphos poisoning.

Bound states of a particle-hole pair are investigated by means of the Bethe-Salpeter equation. Besides the well-known density oscillation, it is shown that transverse collective oscillations are possible. The conditions for the existence of a transverse wave are studied. § I. Introduction It has been shown by many authors that in the many fermion system the collective excitation of a density type wave (plasma oscillation and sound wave) can be considered as a bound state of a particle and a hole and one is able to treat such a bound state by means of the Bethe-Salpeter equation. 1 > In the case of a density wave, the interaction kernel of the Bethe-Salpeter equation is usually given by the lowest order diagram which is shown in Fig. 1. In the case of a plasma oscillation, neglecting .

Relativistic quantum mechanics of a finite one-dimensional continuum is studied in the framework of Dirac's generalized Hamiltonian dynamics. It is shown that the wave equation and subsidiary conditions found by Virasoro in the dual resonance model are equivalent to relativistic quantum mechanics in our system. Interaction with external fields is also studied briefly.

tion .of the system. As far as the spin and the unitary spin quantum numbers are concerned, these excitons can be identified with the quark and the antiquark. In contrast to the conventional quark, however, they ohey the Bose-statistics and have mass about one third of the nucleon mass. Further in this model it can be shown that the triality is restricted to zero. Therefore, particles with fractional electric charge or fractional baryonic number do not appear. Thus, this model eliminates most of the difficulties of the conventional quark model, and it is shown that as far as the low lying levels of the hadrons are concerned, the elementary particles can be understood consistently as the excited state of a deformable sphere. Discussions in this paper are restricted to the l1niform deformations and is done in the non-relativistic approximation. l ) to construct a unified model of elementary particles on the basis of the assumption that the elementary par­ ticles are' not mathematical points but have some spatial extension, trying to identify the internal levels of motion carried by this extended structure with the actual elementary particles. The simplest possibility for such an approach is to assume that tbis struc­ ture is rigid. In this case, the internal motion is the rotation around 1 he center of mass, and in our previolls paper2) this was shown that the eigenfunctions of the system belonging to the eigenstate of this rotational motion have properties very similar to the Dirac spin or. **) The rigid body model is, however, insufficient as the realistic model of elementary particles, since it has no possibility of producing quantum numbers like isospin, hypercharge,··· etc. To· evade this difficulty, 1\vo of the authors (0. H. and T. G.) have tried to relax the condition "rigid ", and considered a deformable body model instead of the rigid body

As is well known, the isospin has been introduced in an intimate relation with the electromagnetic :field. An attempt is made to derive this relation based upon the rigid sphere model of elementary particles, starting from the :five dimensional theory proposed by Kaluza and Klein. The :field equation for the metric :field is given uniquely by the requirement of general covariance. In the :first approximation with respect to the square root of the gravitational constant, this equation reduces to Maxwell's equation with Q=el 3 , where Q is the electric charge and 13 is the third component of the isospin given by Nakano, Takabayasi and Vigier in their theories of the extended particle model of elementary particles. The fact that the electromagnetic :field de:fines a special direction in the isospace follows very natu­ rally from this :field equation. Thus, in our approach all characteristic features of the electromagnetic :field as well as the relation between the electromagnetic :field and the isospin are derived as a necessary consequence of the theory, without any further speci:fic assumptions.