Kondo-Induced Giant Isotropic Negative Thermal Expansion.

Negative thermal expansion is an unusual phenomenon appearing in only a handful of materials, but pursuit and mastery of the phenomenon holds great promise for applications across disciplines and industries. Here we report use of x-ray spectroscopy and diffraction to investigate the 4f-electronic properties in Y-doped SmS and employ the Kondo volume collapse model to interpret the results. Our measurements reveal an unparalleled decrease of the bulk Sm valence by over 20% at low temperatures in the mixed-valent golden phase, which we show is caused by a strong coupling between an emergent Kondo lattice state and a large isotropic volume change. The amplitude and temperature range of the negative thermal expansion appear strongly dependent on the Y concentration and the associated chemical disorder, providing control over the observed effect. This finding opens avenues for the design of Kondo lattice materials with tunable, giant, and isotropic negative thermal expansion.

Discovery of superconductivity in quasicrystal.

Superconductivity is ubiquitous as evidenced by the observation in many crystals including carrier-doped oxides and diamond. Amorphous solids are no exception. However, it remains to be discovered in quasicrystals, in which atoms are ordered over long distances but not in a periodically repeating arrangement. Here we report electrical resistivity, magnetization, and specific-heat measurements of Al-Zn-Mg quasicrystal, presenting convincing evidence for the emergence of bulk superconductivity at a very low transition temperature of [Formula: see text] K. We also find superconductivity in its approximant crystals, structures that are periodic, but that are very similar to quasicrystals. These observations demonstrate that the effective interaction between electrons remains attractive under variation of the atomic arrangement from periodic to quasiperiodic one. The discovery of the superconducting quasicrystal, in which the fractal geometry interplays with superconductivity, opens the door to a new type of superconductivity, fractal superconductivity.

Plasmon modes in single gold nanodiscs.

Optical properties of single gold nanodiscs were studied by scanning near-field optical microscopy. Near-field transmission spectra of a single nanodisc exhibited multiple plasmon resonances in the visible to near-infrared region. Near-field transmission images observed at these resonance wavelengths show wavy spatial features depending on the wavelength of observation. To clarify physical pictures of the images, theoretical simulations based on spatial correlation between electromagnetic fundamental modes inside and outside of the disc were performed. Simulated images reproduced the observed spatial structures excited in the disc. Mode-analysis of the simulated images indicates that the spatial features observed in the transmission images originate mainly from a few fundamental plasmon modes of the disc.

Kv1.3 blockers ameliorate allergic contact dermatitis by preferentially suppressing effector memory T cells in a rat model.

BACKGROUND: The Kv1.3 voltage-gated potassium channel is selectively upregulated upon activation in effector memory T (TEM ) cells in inflamed tissue, and plays an important role in maintenance of T-cell activation. Although Kv1.3 blockers have been shown to ameliorate allergic contact dermatitis (ACD) in a rat model, it remains unknown whether the effect of Kv1.3 blockers on ACD is mediated by suppressing TEM cell function and/or whether naive T-cells or central memory T (TCM ) cells are influenced. AIM: To analyse the detailed mechanism of Kv1.3 blockers in a rat model of ACD. METHODS: We examined the effects of a Kv1.3 blocker on inflammation and production of the effector cytokine interferon (IFN)-γ in inflamed tissue in rat ACD. Single-cell suspensions were isolated from inflamed rat ears (TEM cells), and regional lymph nodes (naive T/TCM cells), and the effect of Kv1.3 blockers on anti-CD3-stimulated IFN-γ production in vitro was measured. RESULTS: The Kv1.3 blocker significantly suppressed ear inflammation and IFN-γ production at the protein level in vivo. It also suppressed in vitro IFN-γ production from TEM cells from inflamed tissues, but did not suppress the function of naive T/TCM cells from lymph nodes. CONCLUSIONS: We found that the Kv1.3 blocker ameliorated ACD by inhibiting TEM cell functions only, thus Kv1.3 blockers could be a potentially selective therapeutic agent for TEM cell-mediated inflammatory skin diseases without producing harmful side-effects.

Topographical organization of TRPV1-immunoreactive epithelium and CGRP-immunoreactive nerve terminals in rodent tongue.

Transient receptor potential vanilloid subfamily member 1 (TRPV1) is activated by capsaicin, acid, and heat and mediates pain through peripheral nerves. In the tongue, TRPV1 expression has been reported also in the epithelium. This indicates a possibility that sensation is first received by the epithelium. However, how nerves receive sensations from the epithelium remains unclear. To clarify the anatomical basis of this interaction, we performed immunohistochemical studies in the rodent tongue to detect TRPV1 and calcitonin gene-related peptide (CGRP), a neural marker. Strong expression of TRPV1 in the epithelium was observed and was restricted to the apex of the tongue. Double immunohistochemical staining revealed that CGRP-expressing nerve terminals were in close apposition to the strongly TRPV1-expressing epithelium of fungiform papilla in the apex of rodent tongues. These results suggest that the TRPV1-expressing epithelium monitors the oral environment and acquired information may then be conducted to the adjacent CGRP-expressing terminals.

Association of T-cell receptor Vbeta haplotypes with dry skin in DS-Nh mice.

BACKGROUND: Although dry skin and T cell-dependent disease exacerbation are characteristic features of atopic dermatitis (AD), the involvement of T cells in the development of dry skin remains unclear. AIMS: We aimed to elucidate the role of T cells in the development of dry skin in DS-Nh mice as a model for AD, and to evaluate this skin condition pharmacologically. METHODS: We prepared DS-Nh mice harbouring a T-cell receptor (TCR)Vbeta(a) haplotype with a central deletion in the TCRBV gene segments, and mice harbouring a TCRVbeta(b) haplotype without any deletion. We analysed the TCRVbeta chain usage and cytokine response to antimouse CD3 monoclonal antibodies in the splenocytes from the two mouse substrains. Transepidermal water loss (TEWL) was measured, and histochemical examination of these mice was carried out. Finally, a pharmacological analysis using loratadine was also performed to evaluate the features of spontaneous dry skin in DS-Nh mice as a model of AD. RESULTS: Although the deletion of TCRBV gene segments in the TCRVbeta(a) haplotype yielded different representations of each TCRVbeta mRNA, this deletion did not evoke distinct cytokine profiles in the splenocytes compared with those of mice with the TCRVbeta(b) haplotype. Furthermore, our results indicated that the onset of dry skin occurred earlier in mice with TCRVbeta(b) than in those with TCRVbeta(a). Pharmacologically, AD-like dry skin in DS-Nh with TCRVbeta(b) mice is susceptible to an H1 blocker. CONCLUSIONS: A specific lymphocyte subpopulation bearing T-cell receptors may be responsible for loratadine-responsive dermatitis in DS-Nh mice.

Identification of the novel localization of tenascinX in the monkey choroid plexus and comparison with the mouse.

Tenascin-X (Tn-X) belongs to the tenascin family of glycoproteins and has been reported to be significantly associated with schizophrenia in a single nucleotide polymorphism analysis in humans. This finding indicates an important role of Tn-X in the central nervous system (CNS). However, details of Tn-X localization are not clear in the primate CNS. Using immunohistochemical techniques, we found novel localizations of Tn-X in the interstitial connective tissue and around blood vessels in the choroid plexus (CP) in macaque monkeys. To verify the reliability of Tn-X localization, we compared the Tn-X localization with the tenascin-C (Tn-C) localization in corresponding regions using neighbouring sections. Localization of Tn-C was not observed in CP. This result indicated consistently restricted localization of Tn-X in CP. Comparative investigations using mouse tissues showed equivalent results. Our observations provide possible insight into specific roles of Tn-X in CP for mammalian CNS function.

Raman and near-field spectroscopic study on localized surface plasmon excitation from the 2D nanostructure of gold nanoparticles.

We have studied electromagnetic field on the surface of two-dimensional nanostructure of gold nanoparticles through two-photon-induced photoluminescence images by using scanning near-field optical microscope and far-field surface-enhanced Raman scattering measurements. The near-field two-photon-induced photoluminescence image shows that strong inhomogeneous enhancement in two-photon-induced photoluminescence occurs over the two-dimensional nanostructure, representing localized surface plasmon excitations. The results suggest that the local structure of the two-dimensional nanostructure influences the distribution of localized surface plasmon excitation.

Deletion of entire HLA-A gene accompanied by an insertion of a retrotransposon.

Unusual HLA-A'null' alleles because of an entire gene deletion were found in three apparently unrelated Japanese families with leukemia patients. Inclusion of the entire HLA-A gene in the deletion was confirmed by polymerase chain reaction direct sequencing of the surrounding regions of HLA-A. Further localization of the breakpoints of the HLA-A deletion at the centromeric and telomeric sides was performed, and these families were shown to possess the identical deletion. We then determined the genomic sequence of the HLA-A-deleted haplotype. Surprisingly, the haplotype turned out to carry an insertion of an SVA (SINE-VNTR-Alu) retrotransposon of 2 kb as well as the 14 kb deletion that included the entire HLA-A gene.

Intravenous atropine treatment in infantile hypertrophic pyloric stenosis.

AIMS: To assess the efficacy of a new regimen of intravenous atropine treatment for infantile hypertrophic pyloric stenosis (IHPS) with special reference to regression of pyloric hypertrophy. METHODS: Atropine was given intravenously at a dose of 0.01 mg/kg six times a day before feeding in 19 patients with IHPS diagnosed from radiographic and ultrasonographic findings. When vomiting ceased and the infants were able to ingest 150 ml/kg/day formula after stepwise increases in feeding volume, they were given 0.02 mg/kg atropine six times a day orally and the dose was decreased stepwise. RESULTS: Of the 19 infants, 17 (89%) ceased projectile vomiting after treatment with intravenous (median seven days) and subsequent oral (median 44 days) atropine administration. The remaining two infants required surgery. No significant complications were encountered. Ultrasonography showed a significant (p < 0.05) decrease in pyloric muscle thickness, but no significant shortening of the pyloric canal after completion of the atropine treatment. The patients exhibited failure to thrive at presentation, but were thriving at 6 months of age (p < 0.01). CONCLUSIONS: This atropine therapy resulted in satisfactory clinical recovery. Pyloric muscle thickness was significantly reduced.

Talin, a host cell protein, interacts directly with the translocated intimin receptor, Tir, of enteropathogenic Escherichia coli, and is essential for pedestal formation.

Enteropathogenic Escherichia coli (EPEC) is able to inject its own receptor, a transmembrane protein called translocated intimin receptor, Tir, into the host epithelial cell. The bacterium then uses an outer membrane protein, intimin, to bind to Tir and remains firmly attached to the host cell surface for the duration of the infection. The bacterium is also able to trigger the rearrangement of several host cell proteins, culminating with the formation of an actin-rich, pedestal-like structure beneath the EPEC adherence site. Although several cytoskeletal proteins are rearranged following EPEC infection, the exact role played by these proteins during pedestal formation remains unknown. We report here that talin, an integrin-binding protein, is recruited by EPEC and associates directly with Tir. By surface plasmon resonance (SPR), the predicted value for the dissociation constant (KD) for Tir-talin binding was 1.86 x 10(-7) M. We also demonstrate that microinjection of anti-talin antibodies into HeLa cells resulted in the complete inability to focus actin filaments beneath the attached bacterium. These findings demonstrate that talin is essential for EPEC-induced pedestal formation in infected cells.

Motor abnormality in the gastroduodenal junction in patients with infantile hypertrophic pyloric stenosis.

BACKGROUND/PURPOSE: Periodic clusters of phasic pressure waves in the gastroduodenal junction (GDJ) have been seen in patients with infantile hypertrophic pyloric stenosis (IHPS). This study investigated the details of these pressure waves in relation to disturbed transpyloric flow in IHPS. METHODS: Manometric study was performed in 11 IHPS patients before and after atropine therapy and 2 non-IHPS infants. Pressure changes in the GDJ were measured with an 8-channel sleeve or a 9-channel sidehole micromanometric assembly under fluoroscopic control for 2 hours. RESULTS: Clusters of phasic pressure waves (365 +/- 42 mm Hg) associated with an increase in basal pressure (10 +/- 3 mm Hg) were intermittently observed in the GDJ in all IHPS patients. Similar observations were not made in the non-IHPS infants. Most antral pressure waves occurred simultaneously with those pressure waves in the GDJ in the IHPS patients. Atropine (0.01 mg/kg) transiently abolished the phasic and tonic pressure waves for 19 +/- 10 minutes. Significantly fewer phasic pressure waves were observed after atropine therapy. CONCLUSIONS: Characteristic phasic and tonic contractile activity in the GDJ is uncoordinated with the antral contractions in IHPS patients. Such incoordination may be an important factor in the disturbed transpyloric flow in IHPS.

Observation of untreated patients with neuroblastoma detected by mass screening: a "wait and see" pilot study.

BACKGROUND: Recent studies have indicated that mass screening for neuroblastoma detects tumors that otherwise would have regressed spontaneously without recognition. Therefore, we started an observation program for these patients to determine how frequently spontaneous regression occurs. PROCEDURE: Eighteen patients were detected by mass screening between June 1994 and December 1996. Eight of these cases matched the following criteria and entered the observation program: Stage I or II, less than 5 cm in diameter; no involvement of large vessels or organs; not difficult to resect; informed consent. If there were an increase in tumor size, an elevation of tumor markers, or evidence of metastasis, the tumor would be immediately resected. RESULTS: Five of the eight cases showed spontaneous regression. Although the remaining three tumors were resected 6-10 months after diagnosis, all patients survived without evidence of recurrence. CONCLUSIONS: At least 60% of neuroblastoma cases who entered our observation program regressed spontaneously.

Direct determination of the permanent dipole moments and structures of Al-CH(3)CN and Al-NH(3) by using a 2-m electrostatic hexapole field.

The supersonic beams of the (1-1) metal-ligand complexes of Al-CH(3)CN and Al-NH(3) were produced by a laser evaporation method. Nondestructive structure selection of the complexes and the dipole moment determination were performed by using a 2-m electrostatic hexapole field. The experimentally determined permanent dipole moments are 1.2 +/- 0.1 D for Al-CH(3)CN and 2.7 +/- 0.2 D for Al-NH(3). We find that the dipole moment of Al-NH(3) becomes larger than that of neat NH(3), while the formation of the Al-CH(3)CN complex produces a smaller dipole moment than that of neat CH(3)CN on the other hand. We performed the ab initio calculations to draw out plausible complex structures and to clarify the bonding character after formation of the complex, and we made comparisons with the computational results done by several groups. The Mulliken population analysis suggests the Al-->CH(3)CN charge flow, but on the other hand the Natural population analysis indicates very little charge flow. For the Al-NH(3) complex, the polarization effect of NH(3) and the N-->Al sigma donation would enhance the dipole moment strength. However, there still remains a controversial disagreement between the theoretical predictions and the experimental results. Further experimental determination using the hexapole method for various metal-ligand complexes and clusters could reveal the basic nature of interaction in the complex systems in general, and this method would complement theoretical calculations.

Usefulness of cord-blood harvesting for autologous transfusion in surgical newborns with antenatal diagnosis of congenital anomalies.

BACKGROUND/PURPOSE: The risks of homologous transfusion and the effectiveness of predeposit autologous transfusion have been described. The authors examined the clinical usefulness of cord-blood harvesting for autologous transfusion in newborns who had congenital anomalies antenatally diagnosed that would require surgical intervention at or near the time of delivery. METHODS: Of 112 cases of antenatal diagnosis of congenital anomalies, 50 mothers gave informed consent and enrolled in this study. Cord-blood was withdrawn immediately after clamping of the umbilical cord and was used for autologous transfusion in newborns within the first 3 days postpartum. RESULTS: A mean of 72 +/- 54 mL of cord-blood was harvested (27 +/- 18 mL/kg). While preserving cord-blood for 3 days at 4 degrees C, no signs of clot formation or hemolysis were observed. The harvested cord-blood included plasma-free Hb ranging from 1 to 68 (13 +/- 18) mg/dL and thrombin-antithrombin III complex ranging from 2 to 273 (18 +/- 50) ng/mL. Bacteriologic examination of the stored cord-blood showed negative cultures, except for samples from 3 newborns after vaginal delivery. A mean of 46 +/- 34 mL of cord-blood was used in 26 patients for autologous transfusion. No significant complications related to cord-blood transfusion were recognized clinically. CONCLUSIONS: Autologous cord-blood transfusion has the potential to be a useful alternative to homologous transfusion in newborns requiring surgery. Adequate collection and storage techniques for cord-blood must be developed. J Pediatr Surg 36:851-854.

Clinicopathologic relationship of hypoganglionosis.

BACKGROUND/PURPOSE: Congenital motor dysfunction of the intestine associated with a morphologically abnormal myenteric nervous plexus (MP) is known as Hirschsprung's disease allied disorder (HAD). However, the clinicopathologic features of HAD are not well understood, partially because a standardized method of histologic evaluation of MP has not been established. To elucidate the clinicopathologic relationship of HAD the authors reviewed 6 cases of HAD using a newly devised histologic evaluation method. METHODS: Flat-mounted frozen sections of the ileum were stained for S-100 protein by fluorescent immunohistochemistry. Quantitative evaluation of MP was performed by measuring the fluorescence-positive area (MP ratio), and the results were compared with those of age-matched normal controls. RESULTS: All of 6 patients required laparotomy within 1 month after birth and enterostomy between 23 days and 10 months. Three died of intractable enteritis by the age of 2.2 years and were totally dependent on parenteral nutrition (PN) throughout their lives. The other 3 have survived for 6 to 10 years but have required PN occasionally. MP ratio in controls was more than 0.34 at all ages, whereas that in HAD was significantly lower than that in controls according to the clinical severity. CONCLUSION: MP size measured on 2-dimensional demonstration is suggested to be an indicator of clinical severity of HAD. J Pediatr Surg 36:898-900.

Operative management for sacrococcygeal teratoma diagnosed in utero.

BACKGROUND/PURPOSE: Sacrococcygeal teratomas (SCT) diagnosed in utero have been reported to be large and associated with high perinatal mortality rate. However, operative management including timing of operation after birth, combined abdominal approach for devascularization, and the position of the patients during resection is not well established. METHODS: A retrospective review of 14 patients with SCT between 1978 and 1999 was performed. To prevent massive bleeding during surgery, the authors used an abdominoperineal resection in the supine position after devascularization. The patients' clinical and sonographic characteristics, prenatal outcome, operative management, and postnatal outcomes were examined. RESULTS: One fetus died in utero. Two patients died within a week, but no late death and no malignant degeneration were noted. A staged operation with devascularization was performed in 2 patients, and 1 death occurred. Surgical management was analyzed between survivors without massive bleeding at surgery (n = 9) and others (n = 4). A significant difference was observed in the subgroup of tumor resection with devascularization or supine position and that of early resection with devascularization or supine position. CONCLUSIONS: Early resection using the abdominoperineal approach supported by close antenatal sonography may be preferable for a favorable outcome. Resection in the supine position after devascularization may have advantages of respiratory management, cardiac resuscitation, and bleeding prevention. J Pediatr Surg 36:545-548.

Clinical characteristics of congenital esophageal stenosis distal to associated esophageal atresia.

BACKGROUND: Congenital esophageal stenosis (CES) has been reported to be a rare association in patients with esophageal atresia or tracheoesophageal fistula, or both (EA-TEF). This study investigates the clinical characteristics of this association with special reference to its treatment. METHODS: A retrospective review of medical and radiographic records of 81 patients who underwent primary repair of EA-TEF was performed. An association of CES was diagnosed when they showed histologic evidence or persistent radiographic images of esophageal narrowing since the neonatal period. RESULTS: Eleven of 81 EA-TEF patients (14%) were identified with CES. Their symptoms were difficulty in swallowing solid food, food impaction, emesis, stridor, repeated respiratory infection, and failure to thrive. Two patients had a recurrence of TEF. Three patients were diagnosed with CES in the neonatal period-2 at the time of primary repair of EA-TEF and 1 on the initial postoperative esophagram. The remaining 8 patients were diagnosed between the ages of 2 months and 3 years. Although esophageal dilatation was attempted in 9 patients, its effectiveness was temporary in all except 2 patients and esophageal laceration occurred in 4 patients. Surgical repair including myotomy and resection of the narrow segment was performed in 7 patients, in 6 of whom Nissen/Collis-Nissen fundoplication was added. A histologic examination was performed in 5 patients, revealing that their CES was due to fibro-muscular hypertrophy (2) or tracheobronchial remnants (3). The long-term outcome was satisfactory in all patients except one who showed wrap herniation. CONCLUSIONS: The association between CES and EA-TEF is not rare. Esophageal dilatation was not universally effective and carried with it a considerable incidence of esophageal leakage. An antireflux operation concomitant with repair of CES may be useful to prevent postoperative gastroesophageal reflux in patients with a narrowing close to the esophagogastric junction.

Respiratory system compliance and postoperative ventilator dependence in neonates with left-sided congenital diaphragmatic hernia.

PURPOSE: The purpose of this prospective consecutive patient study was to test if perioperative respiratory system compliance of patients undergoing surgical repair of congenital diaphragmatic hernia (CDH) can predict the need for prolonged postoperative mechanical ventilation. METHODS: All neonates over 35 weeks of gestation who had surgical repair of left-sided CDH between July 1994 and December 1996 ( n = 10) were included in this study. Static respiratory system compliance (C(rs)) was measured by the passive occlusion method with muscle relaxation before (C(pre)) and after (C(post)) surgical repair of left-sided CDH. We examined the relationship between respiratory system compliance and postoperative ventilator-dependent duration. RESULTS: The mean birthweight-corrected C(post) was lower than that of birthweight-corrected C(pre) (0.41 +/- 0.18 vs 0.54 +/- 0.18 ml.cm H(2)O(-1).kg(-1), P = 0.04). One neonate died on postoperative day 31 from intraventricular hemorrhage, and the other nine neonates survived. The patient who died was excluded from the rest of our calculations. The ventilator-dependent duration was 16.7 +/- 12.3 days. The postoperative ventilator-dependent duration was longer when the birthweight-corrected C(post) was smaller, with a significant correlation between these parameters ( P = 0.006). CONCLUSION: C(post), but not C(pre), may be useful to predict the need for prolonged postoperative mechanical ventilation in neonates with left-sided CDH.