Cluster-Based Haldane State in an Edge-Shared Tetrahedral Spin-Cluster Chain: Fedotovite K_{2}Cu_{3}O(SO_{4})_{3}.

Fedotovite K_{2}Cu_{3}O(SO_{4})_{3} is a candidate of new quantum spin systems, in which the edge-shared tetrahedral (EST) spin clusters consisting of Cu^{2+} are connected by weak intercluster couplings forming a one-dimensional array. Comprehensive experimental studies by magnetic susceptibility, magnetization, heat capacity, and inelastic neutron scattering measurements reveal the presence of an effective S=1 Haldane state below T≅4 K. Rigorous theoretical studies provide an insight into the magnetic state of K_{2}Cu_{3}O(SO_{4})_{3}: an EST cluster makes a triplet in the ground state and a one-dimensional chain of the EST induces a cluster-based Haldane state. We predict that the cluster-based Haldane state emerges whenever the number of tetrahedra in the EST is even.

Quantum dynamics of a driven correlated system coupled to phonons.

Nonequilibrium interplay between charge, spin, and lattice degrees of freedom on a square lattice is studied for a single charge carrier doped in the t-J-Holstein model. In the presence of a static electric field we calculate the quasistationary state. With increasing electron-phonon (e-ph) coupling the carrier mobility decreases; however, we find increased steady state current due to e-ph coupling in the regime of negative differential resistance. We explore the distribution of absorbed energy between the spin and the phonon subsystem. For model parameters as relevant for cuprates, the majority of the gained energy flows into the spin subsystem.

Bipolaron in the t-J model coupled to longitudinal and transverse quantum lattice vibrations.

We explore the influence of two different polarizations of quantum oxygen vibrations on the spacial symmetry of the bound magnetic bipolaron in the context of the t-J model by using exact diagonalization within a limited functional space. Linear as well as quadratic electron-phonon coupling to transverse polarization stabilize d-wave symmetry. The existence of a magnetic background is essential for the formation of a d-wave bipolaron state. With increasing linear electron-phonon coupling to longitudinal polarization the symmetry of a d-wave bipolaron state changes to a p wave. Bipolaron develops a large anisotropic effective mass.

Modeling the antiferromagnetic phase in iron pnictides: weakly ordered state.

We examine electronic states of antiferromagnetic phase in iron pnictides by mean-field calculations of the optical conductivity. We find that a five-band model exhibiting a small magnetic moment, inconsistent with the first-principles calculations, reproduces well the excitation spectra characterized by a multipeak structure emerging below the Néel temperature at low energy, together with an almost temperature-independent structure at high energy. Investigating the interlayer magnetoresistance for this model, we also predict its characteristic field dependence reflecting the Fermi surface.

Doublon-holon pairing mechanism via exchange interaction in two-dimensional cuprate Mott insulators.

Coupling of charge and spin degrees of freedom is a critical feature of correlated electron oxides, as represented by the spin-related mechanism of a Cooper pair under high-T c superconductivity. A doublon-holon pair generated on an antiferromagnetic spin background is also predicted to attract each other via the spin-spin interaction J, similar to a Cooper pair, while its evidence is difficult to obtain experimentally. Here, we investigate such an excitonic effect by electroreflectance spectroscopy using terahertz electric field pulses in undoped cuprates: Nd2CuO4, Sr2CuO2Cl2, and La2CuO4. Analyses of the spectral changes of reflectivity under electric fields reveal that the splitting of odd-parity and even-parity excitons, a measure of doublon-holon binding energy, increases with J. This trend is reproduced by t-J-type model calculations, providing strong evidence of the spin-related doublon-holon pairing. Agreement with the calculations supports the s-wave symmetry of the doublon-holon pair in contrast to the d-wave Cooper pair in doped cuprates.

Late flare-up of nephrotic lupus nephritis transforming histological pattern and autoantibody reactions.

A 15-year-old boy developed a nephrotic syndrome. At that time, autoantibodies related to systemic lupus erythematosus (SLE) had been persistently negative, even on repeated evaluation. C1q was normal, but C4, C3 and CH50 were low. Renal biopsy revealed membranous lupus nephritis (LN) based on the new classification of glomerulonephritis in SLE [Weenig et al. 2004]. We did not establish our diagnosis of SLE on the criteria of the American Rheumatism Association (ARA). The patient showed complete remission ofnephrotic syndrome treated with prednisolone and cyclophosphamide. Thereafter, he had no proteinuria and clinical evidence of SLE for 22 years. At the age of 37, however, he developed facial discoid eruption, proteinuria in the nephrotic range, hypocomplementemia and positive reaction to autoantibodies of SLE. Light microscopic findings of renal biopsy indicated mesangial LN, which showed "full-house" immunofluorescence and mesangial dense deposits associated with diffuse epithelial cell foot process effacement in electron microscopy. Steroid therapy was very effective. This case initially showed autoantibody-negative and hypocomplementemic LN with membranous type, and transformed to SLE with mesangial LN after a long interval.

Recovery After Critical Illness Polyneuropathy in a Patient With Orthotopic Liver Transplantation: A Case Report.

After liver transplantation, some patients show neuromuscular abnormalities. A 43-year-old man with liver cirrhosis due to hepatitis C virus underwent living-donor liver transplantation. He developed severe neuromuscular dysfunction after sepsis, and acute respiratory distress syndrome. After the inflammatory reaction gradually improved, we observed bilateral weakness of the extremities and foot drop. Electrophysiological studies indicated primary axonal degeneration of peripheral motor and sensory fibers without inflammation. Critical illness polyneuropathy was diagnosed. During follow-up, complaints gradually recovered with rehabilitation by approximately 1 year later. Based on this case, we suggest that paralysis should be evaluated for critical illness polyneuropathy in patients with unexplained muscle weakness.

Point nodes persisting far beyond Tc in Bi2212.

In contrast to a complex feature of antinodal state, suffering from competing orders, the pairing gap of cuprates is obtained in the nodal region, which therefore holds the key to the superconducting mechanism. One of the biggest question is whether the point nodal state as a hallmark of d-wave pairing collapses at Tc like the BCS-type superconductors, or it instead survives above Tc turning into the preformed pair state. A difficulty in this issue comes from the small magnitude of the nodal gap, which has been preventing experimentalists from solving it. Here we use a laser ARPES capable of ultrahigh-energy resolution, and detect the point nodes surviving far beyond Tc in Bi2212. By tracking the temperature evolution of spectra, we reveal that the superconductivity occurs when the pair-breaking rate is suppressed smaller than the single-particle scattering rate on cooling, which governs the value of Tc in cuprates.

Two-step gene transfer using an adenoviral vector carrying the CD4 gene and human immunodeficiency viral vectors.

Human immunodeficiency virus-1 (HIV-1) belongs to the lentivirus subfamily of retroviruses and has several interesting features, including T cell tropism and the ability to infect nondividing cells. Replication-incompetent HIV vectors were developed and were shown to be capable of targeted gene transfer into CD4+T cells. This strict T cell tropism may be important for the development of gene therapy of acquired immunodeficiency syndrome (AIDS), but it hampers the use of the HIV vector for other gene transfer applications. To expand the host range of the HIV vector, we established the two-step gene transfer system, which allows us to transduce non-T cells stably. In the first step, the CD4 gene was introduced into target cells using a replication-defective adenoviral vector. Transient but high-level expression of CD4 molecules was detected in both adherent and floating cells. In the subsequent step, the cells were incubated with HIV vectors. Stable integration of the HIV vector was demonstrated in cells transduced with the adenoviral vector. These results indicate that transient expression of CD4 molecules by the adenoviral vector is sufficient to render non-T cells susceptible to HIV-mediated gene transfer. This two-step gene transfer strategy may be used as a general method to transduce various types of human cells stably including nondividing cells.

Stable integration of human immunodeficiency virus-based retroviral vectors into the chromosomes of nondividing cells.

Human immunodeficiency virus type 1 (HIV-1)-based vectors are thought to be useful for gene transfer into nondividing cells. We examined whether HIV vectors can really integrate into the chromosomes of nondividing cells. CD4+HeLa cells arrested at the G2 or G1/S phase were incubated with the HIV vector pseudotyped with the HIV envelope. The transduction efficiency of the HIV vector in these nondividing cells was comparable to that in proliferating cells. Sequencing of the polymerase chain reaction-amplified fragments containing the junction sites showed that the HIV vector was stably integrated into the chromosomal DNA. It was also demonstrated that terminally differentiated human macrophages and nonproliferating NT neurons could be transduced by the HIV vector after adenovirus-mediated expression of CD4. These results suggest that the HIV vector may be useful not only for gene therapy of AIDS but also for a variety of gene therapy protocols targeting nondividing cells.

Molecular milestones that signal axonal maturation and the commitment of human spinal cord precursor cells to the neuronal or glial phenotype in development.

Insights into the programmatic induction of neuronal and glial genes during human embryogenesis have depended largely on extrapolations of data derived from experimental mammals. However, the assumptions upon which these extrapolations are based have not been rigorously tested. Indeed, practically no information is available even on the human counterparts of the relatively small subset of well-characterized, developmentally regulated neuron and glial specific genes of the mammalian CNS. Thus, the developmental programs upon which human neural embryogenesis are based remain largely undeciphered. We have addressed this problem in immunohistochemical studies conducted on 22 human fetal spinal cords with gestational ages (GAs) that ranged from 6 to 40 weeks by using monoclonal antibodies to several classes of neuron or glial specific polypeptides. These polypeptides included: representatives of four different types (Types I-IV) of intermediate filament proteins, i.e., vimentin filament protein (VFP), glial fibrillary acidic protein (GFAP), different phospho-isoforms of the high (NF-H), middle (NF-M), and low (NF-L) molecular weight (Mr) neurofilament (NF) subunits, both acidic and basic cytokeratin (CK) proteins; three different microtubule associated proteins (MAPs), i.e., MAP2, MAP5, and tau; two different synaptic or coated vesicle proteins, i.e., synaptophysin (SYP) and clathrin light chain B (LCb); an oligodendroglial specific protein, i.e., myelin basic protein (MBP); and a receptor for a CNS trophic factor, i.e., the nerve growth factor receptor (NGFR).(ABSTRACT TRUNCATED AT 400 WORDS)

Development of a cryopreservation procedure employing a freezer bag for pancreatic islets using a newly developed cryoprotectant.

One of the most important requirements for success in clinical islet transplantation is the use of a large number of viable donor islets. To achieve this, the ability to cryopreserve islets and to establish an islet bank are critical. Previously, we developed a two-step cryopreservation procedure with freezing tubes utilizing low and high concentrations of dimethyl sulfoxide (DMSO) and using a fully automated cryomachine for human pancreatic islets and porcine islet-like cell clusters (ICCs). Based on these experiments, we developed a simple and efficient cryopreservation procedure of a freezer bag for isolated islets using a fully automated computer-controlled cryomachine with a newly developed cryoprotectant consisting of ethylene glycol (EG) instead of DMSO for decreasing injury of the islets by freezing. A 250 ml Cryocyte blood freezer bag and our newly developed cryoprotectant containing ethylene glycol (EG) were used in the freezing procedure. The islets were frozen by a fully automated computer-controlled cryomachine (GE 9,000) with our original program of slow cooling. Nucleation occurred at -8 degrees C, and the frozen islets were stored at -196 degrees C in a liquid nitrogen tank. The frozen-stored islets were subsequently rapidly thawed in a 37 degrees C water bath and cultured before viability testing. In vitro function, the stimulation index of insulin release during the static incubation test for rat islets cryopreserved in a freezer bag vs. nonfrozen islets as control, was 2.13 +/- 0.42 and 2.02 +/- 0.38 (94.8% compared with control), respectively (n = 5, p = NS). The islet recovery compared with the nonfrozen control group was 85% (n = 5) in insulin content. When 1000 rat islets cryopreserved in a freezer bag were transplanted into the renal capsule of diabetic athymic mice, all the mice became normoglycemic within 7 days from transplantation. Before nephrectomy, the intravenous glucose torelance test (IVGTT) was performed. The fractional decay constant of the glucose level (K value) of the frozen-thawed group was 0.42 +/- 0.06%/min. A histological study of renal subcapsular grafts demonstrated the morphological integrity of the islets. These results demonstrate the utility of our cryopreservation procedure of a freezer bag for isolated islets using a fully automated computer-controlled cryomachine with a newly developed cryoprotectant for the maintenance of viability and function of frozen-stored islets both in culture and after transplantation. Cryopreservation using freezer bags with the new cryoprotectant is an effective and simple method for making an islet bank for clinical trials of islet transplantation.

A distribution study of 11C platelet-activating factor (PAF) analogs in normal and tumor-bearing mice.

As a preliminary study to image platelet-activating factor (PAF) receptors in vivo, comparative study of biodistribution between 1-O-hexadecy1-2-O-N, N-dimethylcarbamoyl-sn-glycero-3-phosphocholine [choline-methyl-11C](L-[11C]dimethylcarbamoyl-PAF) and nonspecific PAF analog, 3-O-hexadecyl-2-O-N,N-dimethylcarbamoyl-sn-glycero-1-phosphocholine [choline-methyl-11C](D-[11C]-dimethylcarbamoyl-PAF) was carried out in both normal and tumor-bearing mice. Higher accumulation of L-[11C]dimethylcarbamoyl-PAF than D-[11C]dimethylcarbamoyl-PAF was observed in normal mice spleen. The co-administration of PAF antagonists dose-dependently reduced the radioactivity level of the L-isomer only in the spleen. In mice bearing Ehrlich tumors and Sarcoma 180, more L-than the D-[11C]-isomer was accumulated in the tumor and spleen. We found that specific accumulation sites for L-[11C]dimethylcarbamoyl-PAF exist in the spleen and tumors than in other tissues. Moreover, the comparison of accumulation between L- and D-[11C] dimethylcarbamoyl-PAF would be a useful procedure for estimation of PAF receptors in vivo.

Family study of women showing development of antibody to human T-cell leukemia virus I and assessment of the risk of vertical transmission of the virus to their children.

When pregnant women were tested for antibody to human T-cell leukemia virus-I, some were found to be positive although they had been negative during the previous pregnancy. In these women, HTLV-I infection was found from pedigree studies to have been acquired from their mothers rather than from their husbands. Furthermore, some of them had apparently remained HTLV-I antibody-negative for long periods after infection. When the breast-fed children of these women, in whom HTLV-I was acquired from their mothers but who were in an HTLV-I antibody-negative state, were also examined for evidence of HTLV-I infection, none was found.

[Clinical value of magnification cerebral angiography (author's transl)].

Magnification carotid and vertebral angiography was performed via femoral catheter with magnification factor of 2.5 to 3.0, utilizing 0.1 X 0.1 ultra fine focal spot, manufactured by Shimadzu Seisakusho, Ltd. The standard angiograms were compared with magnification angiograms in a group of 67 patients with brain tumors and vascular disorders. The magnification angiography was more valuable than conventional angiography in 12 of 17 vascular tumors, while it was rarely valuable for diagnosis of vascular tumors. Aneurysms, occlusive diseases, collateral vessels, and capillary blush were also visualized to better advantage on magnification angiograms. Magnification cerebral angiography is a useful tool for elucidating small vascular branches, but further refinement in the design of focal spots and angiographic techinques is required for further improvement of magnification cerebral angiography.

[A case of hemangioblastoma with subarachnoid dissemination].

A case is reported in which a diffuse subarachnoid dissemination occurred after successful removal of a posterior fossa hemangioblastoma. The patient was a 51-year-old man who suffered from headache and gait disturbance, and who was admitted to our hospital on September 25, 1985. Neurological examination revealed trunkal ataxia and increased intracranial pressure. A CT scan with contrast media revealed a high-density lesion with surrounding low-density area in the posterior fossa. Right vertebral angiography demonstrated a round tumor stain behind the medulla oblongata, which was fed by the right posterior inferior cerebellar artery. The complete resection of the tumor was carried out. A biopsy specimen from the tumor showed a picture characteristic of hemangioblastoma. Fourteen months later the patient was readmitted due to the sudden onset of disturbance of consciousness. A CT scan revealed a large intracerebral hematoma in the right putaminal region. Right carotid angiography demonstrated two small tumor stains in the right temporal lobe. An emergency operation to extirpate the hematoma was performed. But the disturbance of consciousness did not improve, and the patient died. At necropsy a lot of small round tumors were recognized at the surface of the bilateral cerebral and cerebellar cortex. They were present in the subarachnoid space and partially invaded the cerebral and cerebellar parenchyma, extending through Virchow-Robin's space. There was no recurrence of the tumor at the site of the original operation. No doubt, a subarachnoid dissemination had occurred. However the histological findings of tumors were similar to the findings recorded in the first biopsy.

[Glial fibrillary acidic protein and neurofilament protein in medulloblastoma].

Medulloblastoma is the most common primitive neuroectodermal tumor (PNET) with the potential to differentiate along glial or neuronal lines. Thirty cases of medulloblastoma were tested by the peroxidase-antiperoxidase (PAP) method with anti-GFAP serum (DAKO) and by the avidin-biotin peroxidase complex (ABC) method with 68kd subunit of anti-NF antibody. All the cases were classified into three subtypes based on these immunohistochemical findings and were analyzed in relation to clinico-pathological features. Fifteen of thirty medulloblastomas contained GFAP positive cells, seventeen showed cells reacting to NF. The reactions for both proteins were present in eight medulloblastomas (PNET-BD, bipotential differentiation). Seventeen medulloblastomas reacted to only one protein (PNET-MD, monopotential differentiation). No reaction for either was found in five cases (PNET-NOS, not otherwise specified). The two year survival rate was 12.5% for PNET-BD compared to 49.2% for PNET-MD and 53.3% for PNET-NOS. Nine variables, i.e. age, tumor stage, metastatic stage, operation, radiotherapy, chemotherapy, histology, GFAP and NF, were analyzed using Cox's proportional hazard model. This revealed that the significant factors were tumor stage (p = 0.0002), GFAP (p = 0.0008) and operation (p less than 0.05). In conclusion, GFAP is the most important histological factor for prognosis and medulloblastoma without glial differentiation has a much better prognosis than one with glial differentiation.

[Clinicopathological study of supratentorial tumors with multipotential differentiation in childhood. Primitive neuroectodermal tumor].

Three cases of supratentorial tumor in childhood were studied clinico-pathologically in an attempt to clarify its histological character. Case 1: A 3-year-old boy. Carotid angiogram revealed avascular lesion in the left parietal lobe. Twice operations and radiotherapy were performed. Ten months after the second operation, he died. Surgical specimen at the first operation was composed mainly of round tumor cells. The tumor tissue contained many collagen fibers. At the periphery of this tissue, medulloblastomatous areas consisting of closely aggregated hyperchromatic small round cells were found. There were perivascular rosettes and Homer Wright rosettes. In part, tubular and papillary arrangement of cells was also present. Astrocytomatous and oligodendrogliomatous structures were also present. Surgical specimens at the second operation showed the predominance of sarcomatous areas consisting of spindle-shaped cells with abundant argyrophilic fibers. Case 2: A 10-year-old girl. CT scan revealed a heterogeneous enhanced mass with a cyst and calcification in the right parietal lobe. Operation and radiotherapy were performed. Twelve months after operation, she is still alive. Most of the surgical specimens showed sarcomatous structure with abundant argyrophilic fibers. In these tissues, there were medulloblastomatous and ependymomatous features. Papillary arrangement of cells was also present. In part, there was oligodendrogliomatous structure. Case 3: A 2-year-old girl. CT scan revealed a heterogeneous enhanced mass in the right frontal lobe. The tumor tissue was composed of an aggregation of undifferentiated small round cells with Homer Wright rosettes.(ABSTRACT TRUNCATED AT 250 WORDS)

[Treatment of malignant brain tumors with slowly releasing anticancer drug-polymer composites].

The purpose of this study is to present the methodology and results of a clinical trial of local chemotherapy of malignant brain tumors based on slowly-releasing anticancer drug-polymer composites. The slowly releasing drugs were prepared by combining and mutually dispersing anticancer agents with glassified monomers containing 10% polymetacrylic methyl acid and then this compound was frozen at -78 degrees C and exposed to 1 X 10(6) rad of gamma rays from cobalt 60. Thus we prepared a compound of polymers and anticancer agents. We used needle-shaped capsules of this compound. These capsules release the drug very slowly over 40 days. We administered locally to the malignant brain tumors with either slowly releasing mitomycin, slowly releasing adriamycin, slowly releasing ACNU or slowly releasing 5 Fu drugs. The following techniques were employed in implantation these capsules. Implantation into the remaining tumor wall at the time of excision. Implantation into the tumor by CT-guided stereotactic method. We implanted these drugs into tumor of 55 cases, thereafter we conducted both radiation and chemotherapy with ACNU in most patients. This method has the following advantages: It is possible to be employed to different types of anticancer agents. Both dosage and releasing time can be adjusted. It is possible to administer these capsules postoperatively by the stereotactic method. The clinical study consists of 55 patients, 20 cases of anaplastic astrocytoma, 23 cases of glioblastoma multiforme, 5 cases of oligodendroglioma, 3 cases of medulloblastoma and 4 cases of others. Survival rate estimated by Kaplan-Meier method was 47% in glioblastoma at 12 months and 91% in anaplastic astrocytoma at 18 months.(ABSTRACT TRUNCATED AT 250 WORDS)

[Guidance of community mental health training for psychiatry residents].

Compared to other advanced countries, the field of mental health in Japan is characterized by a large hospitalized to general population ratio and a long mean hospitalization period. This is in large part attributable to the lack of appropriate housing as well as occupational recreational centers after discharge. At the same time the education of psychiatric medical staff has focused on the hospital environment, with little attention devoted to training at centers of community mental health. This hospital-dominant approach has been difficult to shed, and has persisted since the WHO report of Dr. Clark in 1968. Paralleling the introduction of the certified doctor system, at the Japanese Society of Psychiatry and Neurology recently, the manner of postgraduate training for psychiatrists and attempts to reform it were debated. In the midst of this debate, a consensus has emerged that study of community mental health is one of the minimum requirements to become a full-fledged psychiatrist. However, no adequate community mental health training programs have been established at any institution. At Nara Medical University hospitals, considerable weight has been placed on community mental health training, with such a training program designed and put into practice. In the present report, this training program is introduced and interim results reported, and the problems associated with community mental health training are discussed.