Unconventional exciton evolution from the pseudogap to superconducting phases in cuprates.

Electron quasiparticles play a crucial role in simplifying the description of many-body physics in solids with surprising success. Conventional Landau's Fermi-liquid and quasiparticle theories for high-temperature superconducting cuprates have, however, received skepticism from various angles. A path-breaking framework of electron fractionalization has been established to replace the Fermi-liquid theory for systems that show the fractional quantum Hall effect and the Mott insulating phenomena; whether it captures the essential physics of the pseudogap and superconducting phases of cuprates is still an open issue. Here, we show that excitonic excitation of optimally doped Bi2Sr2CaCu2O8+δ with energy far above the superconducting-gap energy scale, about 1 eV or even higher, is unusually enhanced by the onset of superconductivity. Our finding proves the involvement of such high-energy excitons in superconductivity. Therefore, the observed enhancement in the spectral weight of excitons imposes a crucial constraint on theories for the pseudogap and superconducting mechanisms. A simple two-component fermion model which embodies electron fractionalization in the pseudogap state provides a possible mechanism of this enhancement, pointing toward a novel route for understanding the electronic structure of superconducting cuprates.

Stromal-type Nephroblastoma with or without Anaplasia in Two Hedgehogs (Atelerix albiventris).

We describe the clinical and histological characteristics of stromal-type nephroblastomas that developed in two hedgehogs (Atelerix albiventris). In case 1, the tumour was composed of a proliferation of anaplastic stromal cells with ductal structures resembling the epithelium of nephroblastoma. In case 2, spindle-shaped cells that were somewhat larger than nephroblasts were frequently seen surrounding the cell cluster, and there was proliferation of stromal cells with collagen fibres at the periphery. Immunohistochemically, the tumour cells labelled weakly to strongly for the nephroblast marker Wilms' tumour-1 and were positive for Ki67 with rates of 5% and 10% for cases 1 and 2, respectively. Based on the above, the diagnosis was of stromal-type nephroblastoma with anaplasia in case 1 and without anaplasia in case 2. Our findings suggest that stromal-type nephroblastomas arise in adult hedgehogs and are clinically benign, and that histological anaplasia does not affect the prognosis.

A patient with elderly-onset atypical hydroa vacciniforme with an indolent clinical course.

Hydroa vacciniforme (HV) is a rare photodermatosis that mainly affects children and manifests as vesiculopapular eruptions in sun-exposed areas without systemic symptoms. HV-like lymphoma (HVLL) is one of the Epstein-Barr virus (EBV)-associated lymphoproliferative disorders (LPD) of childhood. Its diagnosis is based on monoclonal T-cell proliferation; however, its degree of malignancy is controversial owing to its variable prognosis. Elderly-onset cases of these diseases are extremely rare, and the clinical features remain unknown. It has been shown that late onset is closely associated with a severe phenotype in EBV-associated LPD including atypical HV. Here we describe a case of elderly-onset atypical HV accompanied by T-cell monoclonality, but with a very indolent clinical course. Our patient indicates a possible case with elderly-onset atypical HV manifesting a favourable course, and that T-cell monoclonality and age of onset cannot always predict the disease severity, and highlights the difficulty of prognosis prediction in elderly-onset atypical HV.

The prevalence of and factors related to calcium pyrophosphate dihydrate crystal deposition in the knee joint.

OBJECTIVES: The purpose of this study was to reveal the accurate prevalence and related factors to the presence of calcium pyrophosphate dihydrate (CPPD) crystal deposition in cadaveric knee joints. DESIGN: Controlled laboratory study. METHODS: Six hundred and eight knees from 304 cadavers (332 male knees and 276 female knees, formalin fixed, Japanese anatomical specimens) were included in this study. The average age of the cadavers was 78.3 ± 10.7 years. Knees were macroscopically evaluated for the existence of CPPD, and the depth of cartilage degeneration of the femoro-tibial joint following the Outerbridge's classification. CPPD crystal was confirmed under Fourier transform infrared spectroscopy (FTIR) analysis using light microscopy. Statistical analysis was performed to reveal the correlation between the occurrence of CPPD deposition in the knee joint and gender, age, and the depth of cartilage degeneration of the femoro-tibial joint. RESULTS: The prevalence of grossly visible CPPD crystal was 13% (79 knees). In all of these knees, CPPD crystal was confirmed under FTIR analysis. Statistical analysis showed significant correlation between the occurrence of CPPD deposition and gender (P < 0.001), and depth of cartilage degeneration in the femoro-tibial joint (P < 0.001). In the cartilage degeneration positive knees (Over grade 3 in Outerbridge's classification), average age of CPPD deposition knee was significantly higher than CPPD negative knees. CONCLUSIONS: In this study, the prevalence of CPPD deposition disease was evaluated in a relatively large sample size of cadaveric knees. The prevalence of CPPD deposition disease was 13%, and was significantly correlated with the subject's age, gender, and severity of cartilage degeneration in the femoro-tibial joint.

Raman-scattering measurements and theory of the energy-momentum spectrum for underdoped Bi2Sr2CaCuO(8+δ) superconductors: evidence of an s-wave structure for the pseudogap.

We reveal the full energy-momentum structure of the pseudogap of underdoped high-Tc cuprate superconductors. Our combined theoretical and experimental analysis explains the spectral-weight suppression observed in the B2g Raman response at finite energies in terms of a pseudogap appearing in the single-electron excitation spectra above the Fermi level in the nodal direction of momentum space. This result suggests an s-wave pseudogap (which never closes in the energy-momentum space), distinct from the d-wave superconducting gap. Recent tunneling and photoemission experiments on underdoped cuprates also find a natural explanation within the s-wave pseudogap scenario.

Ab initio studies on the interplay between spin-orbit interaction and Coulomb correlation in Sr2IrO4 and Ba2IrO4.

Ab initio analyses of A(2)IrO(4) (A=Sr,Ba) are presented. Effective Hubbard-type models for Ir 5d t(2g) manifolds downfolded from the global band structure are solved based on the dynamical mean-field theory. The results for A=Sr and Ba correctly reproduce paramagnetic metals undergoing continuous transitions to insulators below the Néel temperature T(N). These compounds are classified not into Mott insulators but into Slater insulators. However, the insulating gap opens by a synergy of the Néel order and significant band renormalization, which is also manifested by a 2D bad metallic behavior in the paramagnetic phase near the quantum criticality.

Characterization of a novel Entamoeba histolytica strain from Burkina Faso, Africa, possessing a unique hexokinase-2 gene.

An Entamoeba histolytica strain (BF-841 cl1) that originated from Burkina Faso, Africa presented with novel, polymorphic genotypes of the serine-rich E. histolytica protein and the anodic hexokinase­2 (HXK-2) isoenzyme band, which showed less electrophoretic mobility than that of an E. histolytica reference strain [HM-1:IMSS cl6 (zymodeme (Z)-II)] by starch gel electrophoresis and isoelectric focusing (IEF). The HXK-2 gene of BF-841 cl1 had amino acid variations at four positions compared to the sequence of HM-1:IMSS cl6. These variations were absent from the sequences of four other E. histolytica strains with different zymodemes [KU27 (Z-II), SAW1627 (Z-IIa-), SAW755CR clB (Z-XIV), and KU2 (Z-XIX)]. The results of IEF showed no difference in the substrate specificity of HXK (HXK-1 and HXK-2) between BF-841 cl1 and the three reference E. histolytica strains (HM-1:IMSS cl6, SAW755 clB, and KU27). It was also confirmed that BF-841 cl1 was able to form liver abscesses in Syrian hamsters.

Utility of urinary pyridinoline and deoxypyridinoline ratio for diagnosis of osteoarthritis at temporomandibular joint.

BACKGROUND: Pyridinoline (Pyr) and deoxypyridinoline (Dpyr) collagen cross-links are known markers of bone and cartilage turnover that are found in urine in various diseases. The present study was designed to quantify Pyr and Dpyr levels in urine of patients with osteoarthritis (OA) of the temporomandibular joint (TMJ), and to evaluate whether their concentrations are related to specific pathologic findings in the TMJ. METHODS: Urine samples were obtained from 12 patients with OA of the TMJ and 16 asymptomatic controls, and following appropriate preparation, analyzed by high-performance liquid chromatography (HPLC) and fluorescence spectroscopy for Pyr and Dpyr. RESULTS: The urinary concentration of Pyr and the Pyr to Dpyr (Pyr/Dpyr) ratio were significantly higher (P < 0.05) in OA patients than in the controls (182.2 +/- 86.5 pmol/ml vs. 115.6 +/- 27.9 pmol/ml and 4.00 +/- 1.53 pmol/ml vs. 2.86 +/- 0.97 pmol/ml, respectively). However, the Pyr/Dpyr ratio was not associated with any specific clinical or radiographic findings. CONCLUSION: These findings suggest that the level of Pyr and the Pyr/Dpyr ratio in urine may be a useful diagnostic indicator for intra-articular pathologic changes during TMJ OA.

Characteristics and surgical outcomes of paediatric retinal detachment.

PURPOSE: To report the clinical features and surgical and visual outcomes of rhegmatogenous retinal detachment (RRD) in the paediatric population. METHODS: A retrospective review of children (aged 0-15 years) who underwent primary surgical repair for RRD at the Hiroshima University Hospital between 1988 and 2001. RESULTS: In all 53 eyes of 49 patients were identified; paediatric RRD accounted for 3.1% of 1779 eyes with RRD operated on during this period. The causes of RRD included blunt trauma (27%), myopia (25%), idiopathic (20%), familial exudative vitreoretinopathy (13%), and others. Among 55 eyes, 12 (22%) already had proliferative vitreoretinopathy (PVR) of grade C or D preoperatively. The median initial visual acuity (VA) was 0.3. Retinal reattachment was achieved with a single operation in 78%. Final retinal reattachment was achieved in 87%. Retinal reattachment rates with and without PVR were 42% and 100%, respectively (P<0.01). Median final VA was 0.7. Final VA was > or =0.1 in 73% and > or =0.5 in 53%; four eyes had a final VA of no light perception. The presence of preoperative PVR (P=0.03) and the initial VA (P<0.0001) significantly affected final VA. CONCLUSIONS: Paediatric RRD is characterised by a delay in diagnosis, as evidenced by the high rate of PVR at presentation. Retinal reattachment was adversely affected by the presence of PVR. Final VA correlated with the initial VA and was significantly affected by preoperative PVR. Early diagnosis may improve the visual prognosis of paediatric retinal detachment.

Association between craniofacial growth and urinary bone metabolic markers (pyridinoline, deoxypyridinoline) in growing rats.

Pyridinoline (Pyr) and deoxypyridinoline (Dpyr) are intermolecular cross-links of mature collagen and reflect the bone turnover. The purpose of this study was to elucidate the association between craniofacial growth and urinary Pyr and Dpyr levels. Lateral cephalograms and 24-hour urine were taken for 7 male rats from 5 to 20 wks old. The urinary Pyr and Dpyr were quantified by high-performance liquid chromatography. The neurocranium and upper viscerocranium exhibited significant increases in size, with the maximum rate at around 6 wks old. The mandible presented more substantial growth, with the maximum change at 8 wks old. The urinary Pyr and Dpyr levels gradually increased and reached the maximum at 8 wks old. No prominent association was found between neurocranial growth and urinary levels of pyridinium cross-links, whereas Pyr and Dpyr levels exhibited similar time-dependent metabolic changes to mandibular growth. In conclusion, it is shown that urinary pyridinium cross-links may be useful for the prediction of mandibular growth.

Treatment outcome of maxillary sinus squamous cell carcinoma.

BACKGROUND: Optimal treatment policies of maxillary sinus carcinoma remain to be defined. METHODS: Seventy-four patients with squamous cell carcinoma of maxillary sinus were treated at Department of Otolaryngology, Asahikawa Medical College between 1983 and 1997. The T classification according to the 1997 International Union Against Cancer was as follows: 9 with T2, 35 with T3, and 30 with T4. Eight patients had lymph node metastasis with N1 at diagnosis. Of 62 patients who started multimodality therapy that comprised preoperative radiochemotherapy including local irradiation with total dose of 50 grays along with concomitant intramaxillary arterial infusion of 5-fluorouracil with total dose of 5000 mg followed by total or partial maxillectomy, 59 received the complete therapy. Eleven patients had to be treated with radiotherapy alone, and 1 patient received postoperative radiotherapy. The median follow-up time for surviving patients was 117 months. RESULTS: The 5-year overall survival, disease free survival, and local control (LC) rates for all patients were 58.5%, 63.7%, and 73.6%, respectively. The patients who underwent multimodality therapy showed significantly better 5-year overall survival, disease free survival, and LC rates as compared with those who underwent radiotherapy alone (68.5% vs. 9.1%; 73.2% vs. 18.2%; 84.0% vs. 18.2%; P < 0.0001 each). Multivariate analysis revealed that T classification and treatment modality are independent predictors for disease free survival. CONCLUSIONS: The authors' treatment method, which did not include any complicated techniques, produced higher survival and LC rates because of high effectiveness of multimodality therapy. They concluded that their multimodality therapy could offer a better chance for cure from maxillary sinus carcinoma at many institutions.

Expression of mouse osteocalcin transcripts, OG1 and OG2, is differently regulated in bone tissues and osteoblast cultures.

Osteocalcin is a noncollagenous protein that is abundant in mineralized bone matrix. Mice have a gene cluster of osteocalcin that consists of OG1, OG2, and ORG. We established a new method to directly analyze the expression levels of OG1, OG2, and ORG mRNAs relative to total osteocalcin mRNA. They were amplified as 371-bp fragments by reverse transcription-polymerase chain reaction (RT-PCR) at the same time using common primers, digested with ApaLI, and separated in a polyacrylamide gel. ApaLI digestion did not affect the mobility of the OG1-derived 371-bp fragment, whereas both 371-bp fragments, derived from OG2 and ORG, were digested into 350 bp. Total RNA prepared from mouse bone was then subjected to RT-PCR followed by ApaLI digestion. OG1 and OG2 mRNAs were found to be expressed at ratios of 80%-86% and 14%-20%, respectively, to the total osteocalcin mRNA in mouse bone. The ratios were almost constant in various bones in vivo, independent of the animal's genetic background, age, or gender, or different parts of bone. RT-PCR using specific primers revealed that mouse bone tissues strongly expressed osteocalcin mRNA derived from OG1 and OG2, but not ORG. In contrast, cells cultured in vitro showed different expression ratios of osteocalcin mRNA: 53%-65% for OG1 and 35%-47% for OG2 to the total osteocalcin mRNA in the osteoblast cell line and primary osteoblasts in culture even though they formed many mineralized bone nodules. Similar results were obtained in both KS483 osteoblasts and C2C12 myoblasts, when they were cultured with bone morphogenetic protein-2 (BMP-2) to induce osteocalcin mRNA. Taken together, these findings indicate that OG1 is the predominant transcript among the three osteocalcin genes in mouse bone in vivo. It is also suggested that the expression of OG1 and OG2 is regulated differently in bone tissues and osteoblast cultures.

The expression of osteopontin with condylar remodeling in growing rats.

It is suggested that osteopontin may promote osteoclast binding to resorptive sites by interacting with the alphavbeta3 receptor on osteoclasts. However, the role of osteopontin in functional remodeling of bony structures remains unclear. The present study was conducted to examine the distribution of osteopontin on the condyle and explore the role in condylar remodeling in growing rats using an immunohistochemical method. Twenty Wistar strain male rats aged 7, 14, 28 and 56 days were used. In 7- and 14-day-old rats, no immunoreaction to osteopontin was detected in the cartilage cells. In 28-day-old rats initiating mastication, the thickness of condylar cartilage was decreased abruptly as compared to the younger rats. High immunoreaction to osteopontin was found in the cytoplasm of hypertrophic chondrocytes and on the trabecular bone surfaces of primary spongiosa adjacent to the osteoclasts or chondroclasts. The immunoreactions to osteopontin in the cytoplasm of hypertrophic chondrocytes were less in 56-day-old rats than in 28-day-old rats. It is shown that the alteration in mechanical loading on the mandibular condyle due to functional changes from weaning to mastication correlates with the localization of osteopontin in growing rats. Furthermore, it is suggested that osteopontin may stimulate osteoclastic resorption of calcified matrix by mediating the attachment of osteoclasts and/or chondroclasts during growth-related functional remodeling of the condyle.

Polarization mode control of two-dimensional photonic crystal laser by unit cell structure design.

We demonstrate polarization mode selection in a two-dimensional (2D) photonic crystal laser by controlling the geometry of the unit cell structure. As the band diagram of the square-lattice photonic crystal is influenced by the unit cell structure, calculations reveal that changing the structure from a circular to an elliptical geometry should result in a strong modification of the electromagnetic field distributions at the band edges. Such a structural modification is expected to provide a mechanism for controlling the polarization modes of the emitted light. A square-lattice photonic crystal with the elliptical unit cell structure has been fabricated and integrated with a gain media. The observed coherent 2D lasing action with a single wavelength and controlled polarization is in good agreement with the predicted behavior.

A morphological study of age changes in adult human auricular cartilage with special emphasis on elastic fibers.

OBJECTIVE: It is well known that the size of the human auricle increases after it has finished development. The reason why the size of the human auricle continues to enlarge until advanced age after reaching adulthood was investigated by observation of the ultrastructure of elastic fibers in human auricular cartilage. METHODS: A total of 1958 subjects (966 males and 992 females) were classified into 18 age groups from 0 to 5 years up to 85 years and above by 5-year intervals. Ear length, ear width, and length of ear attachment were measured with calipers. Human auricular cartilage was obtained from 26 subjects (16 males and 10 females) aged 14 to 79 years, stained by orcein, and examined by light and electron microscopy. RESULTS: Each item of measurement of human auricular size increased significantly with age in both males and females. On morphological examination by light and electron microscopy after orcein staining, elastic fibers in the cartilage were almost homogeneous in diameter and surrounded the cartilage lacuna in bundle-like fashion in young persons, whereas those in elderly persons were heterogeneous in thickness and had many fragments surrounding the territorial matrix. In elderly persons, collagen-like fibers and small vesicles with heterogeneous electron density were frequently observed near elastic bundles around the territorial matrix. CONCLUSION: Structural changes of auricular cartilage associated with morphological age changes of elastic fibers may be one of the causes of expansion of the auricle after reaching adulthood.

Characterization of transsulfuration and cysteine biosynthetic pathways in the protozoan hemoflagellate, Trypanosoma cruzi. Isolation and molecular characterization of cystathionine beta-synthase and serine acetyltransferase from Trypanosoma.

Sulfur-containing amino acids play an important role in a variety of cellular functions such as protein synthesis, methylation, and polyamine and glutathione synthesis. We cloned and characterized cDNA encoding cystathionine beta-synthase (CBS), which is a key enzyme of transsulfuration pathway, from a hemoflagellate protozoan parasite Trypanosoma cruzi. T. cruzi CBS, unlike mammalian CBS, lacks the regulatory carboxyl terminus, does not contain heme, and is not activated by S-adenosylmethionine. T. cruzi CBS mRNA is expressed as at least six independent isotypes with sequence microheterogeneity from tandemly linked multicopy genes. The enzyme forms a homotetramer and, in addition to CBS activity, the enzyme has serine sulfhydrylase and cysteine synthase (CS) activities in vitro. Expression of the T. cruzi CBS in Saccharomyces cerevisiae and Escherichia coli demonstrates that the CBS and CS activities are functional in vivo. Enzymatic studies on T. cruzi extracts indicate that there is an additional CS enzyme and stage-specific control of CBS and CS expression. We also cloned and characterized cDNA encoding serine acetyltransferase (SAT), a key enzyme in the sulfate assimilatory cysteine biosynthetic pathway. Dissimilar to bacterial and plant SAT, a recombinant T. cruzi SAT showed allosteric inhibition by l-cysteine, l-cystine, and, to a lesser extent, glutathione. Together, these studies demonstrate the T. cruzi is a unique protist in possessing both transsulfuration and sulfur assimilatory pathways.

[Efficacy of tonsillectomy on psoriasis and tonsil histology].

Treatment outcomes of tonsillectomy were studied in 7 Japanese patients with psoriasis--3 males and 4 females aged 9 to 46 years (median: 23 years)--followed up 2 to 9 years after tonsillectomy. All skin lesions disappeared in 3 patients, 80% of those in 2, and no change in the remaining 2 during follow-up. Of 5 in whom skin lesions improved, 4 were females and had a history of tonsillitis making skin lesions worse. In quantitative immunohistologic analysis on tonsillar tissues by CD20 and anti-ssDNA antibodies, areas of T cell-nodules were significantly expanded, but those of the B-lymphoid follicles were smaller, and the number of apoptotic cells increased in tonsils from patients with psoriasis and PPP compared to those with recurrent tonsillitis. The area of T cell-nodules and the number of apoptosis cells were significantly larger in tonsils from 4 patients with complete recovery after tonsillectomy compared to the remaining 9 without complete recovery. This suggests that histologic evaluation may be helpful in estimating the effectiveness of tonsillectomy.

Reduced nasal nitric oxide in diffuse panbronchiolitis.

Diffuse panbronchiolitis (DPB) is a pulmonary disease of unknown origin with inflammation in the respiratory bronchioles, bronchiectasis, and recurrent sinusitis. Patients with DPB suffer from chronic airway infections resulting from mucociliary dysfunction. Whereas a high concentration of nasal nitric oxide (NO) has been documented in healthy subjects, only two diseases are known to reduce nasal NO: primary ciliary dyskinesia syndrome and cystic fibrosis. We hypothesized that patients with DPB have abnormal levels of nasal NO. To test our hypothesis, we measured NO with the chemiluminescence technique. Air was sampled directly from the nose in 15 healthy subjects and eight patients with DPB. Nasal NO was 88% lower in DPB patients than in the age-matched control subjects (69 +/- 70 versus 556 +/- 87 nl/min; p < 0.001). Treatment with erythromycin for 2 wk did not alter the nasal NO in four control subjects. DPB is the third pulmonary disease in which nasal NO is low. The reduced nasal NO may well be involved in the pathogenesis of DPB, and NO measurements may serve as a noninvasive test in the diagnosis of DPB.

Superconductivity from flat dispersion designed in doped mott insulators

Routes to enhance superconducting instability are explored for doped Mott insulators. With the help of insight for criticalities of metal-insulator transitions, geometrical design of lattice structure is proposed to control the instability. A guideline is to explicitly make flat band dispersions near the Fermi level without suppressing two-particle channels. In a one-dimensional model, numerical studies show that our prescription with finite-ranged hoppings realizes large enhancement of spin-gap and pairing dominant regions. We also propose several multiband systems, where the pairing is driven by intersite Coulomb repulsion.

Trapping and emission of photons by a single defect in a photonic bandgap structure

By introducing artificial defects and/or light-emitters into photonic bandgap structures, it should be possible to manipulate photons. For example, it has been predicted that strong localization (or trapping) of photons should occur in structures with single defects, and that the propagation of photons should be controllable using arrays of defects. But there has been little experimental progress in this regard, with the exception of a laser based on a single-defect photonic crystal. Here we demonstrate photon trapping by a single defect that has been created artificially inside a two-dimensional photonic bandgap structure. Photons propagating through a linear waveguide are trapped by the defect, which then emits them to free space. We envisage that this phenomenon may be used in ultra-small optical devices whose function is to selectively drop (or add) photons with various energies from (or to) optical communication traffic. More generally, our work should facilitate the development of all-optical circuits incorporating photonic bandgap waveguides and resonators.