Quantum spin liquids unveil the genuine Mott state.

The localization of charge carriers by electronic repulsion was suggested by Mott in the 1930s to explain the insulating state observed in supposedly metallic NiO. The Mott metal-insulator transition has been subject of intense investigations ever since1-3-not least for its relation to high-temperature superconductivity4. A detailed comparison to real materials, however, is lacking because the pristine Mott state is commonly obscured by antiferromagnetism and a complicated band structure. Here we study organic quantum spin liquids, prototype realizations of the single-band Hubbard model in the absence of magnetic order. Mapping the Hubbard bands by optical spectroscopy provides an absolute measure of the interaction strength and bandwidth-the crucial parameters that enter calculations. In this way, we advance beyond conventional temperature-pressure plots and quantitatively compose a generic phase diagram for all genuine Mott insulators based on the absolute strength of the electronic correlations. We also identify metallic quantum fluctuations as a precursor of the Mott insulator-metal transition, previously predicted but never observed. Our results suggest that all relevant phenomena in the phase diagram scale with the Coulomb repulsion U, which provides a direct link to unconventional superconductivity in cuprates and other strongly correlated materials.

Influence of backrest angle on swallowing musculature activity and physical strain during the head lift exercise in elderly women compared with young women.

The head lift exercise (HLE) is the most common exercise for strengthening the swallowing musculature in clinical situations. This study investigated whether a change in the backrest angle of a bed influences swallowing musculature activity and physical strain during the HLE and whether it can generate an appropriate exercise load for swallowing musculature activity for older women compared with younger women. Participants were 10 elderly women and 10 young women, each of whom performed the HLE with a backrest randomly angled at 0°, 15°, 30° and 45°. The activity of the suprahyoid, infrahyoid and sternocleidomastoid muscles was assessed with electromyography. The perception of fatigue was measured with the Borg Rating of Perceived Exertion Scale. The activity of the infrahyoid and sternocleidomastoid muscles in elderly women was significantly lower when the angle of the backrest was raised to 45° vs 0°. In both groups, the Borg rating decreased significantly at the 30° and 45° backrest positions vs the 0° and 15° positions. The activity required for the suprahyoid and infrahyoid muscles in elderly women at a 30° backrest position was almost equal to the activity required by these muscles in young women at a 0° backrest position. In elderly women, it is possible that the HLE with the backrest at a 30° angle may be easier and provide a more appropriate exercise load for strengthening the swallowing muscles.

Resection of spinous processes can cause spinal cord injury in patient with ossification of the posterior longitudinal ligament in the thoracic spine.

STUDY DESIGN: Case report. OBJECTIVE: To report intraoperative spinal cord injury by resection of spinous processes in a 73-year-old man with ossification of the posterior longitudinal ligament (OPLL) in the thoracic spine. METHODS: A 73-year-old man presented with cervicothoracic OPLL with bilateral numbness and clumsiness of his hand, weakness of his lower extremities and severe gait disturbance. His Japanese Orthopaedic Association (JOA) score was 7.5 out of 17. Cervical laminoplasty (C2-6), cervicothoracic laminectomy (C7-T10) and posterior fusion (C7-T10) were performed in the prone position with electrophysiologic monitoring of the spinal cord-evoked potentials (SCEPs). RESULTS: The spinal processes with supra- and interspinous ligaments between C7 and T10 were resected. After resection, the amplitude of SCEP waveforms decreased rapidly to <10% of control levels. Laminectomy was performed, and, after 80 min of SCEP deterioration, an instrumented fusion with correction for kyphosis was completed. The SCEP amplitude recovered gradually. Immediately after surgery, the patient suffered severe motor loss in both lower limbs. His neurological recovery progressed gradually from 2 days after surgery, and he was able to walk at 3 months after surgery. At 6 years after surgery, the JOA score was 11. CONCLUSION: Our results suggest that intraoperative spinal cord injury can occur before posterior decompression by resection of spinal processes with supra- and interspinous ligaments. The timing of the instrumented stabilization using a temporary rod is important and should be considered immediately after posterior exposure of the spine.

Influence of leukotriene pathway polymorphisms on clinical responses to montelukast in Japanese patients with asthma.

WHAT IS KNOWN AND OBJECTIVE: Montelukast, a cysteinyl leukotriene receptor 1 antagonist, is safe and efficacious in patients with asthma. The mechanisms underlying the significant interpatient variability in response to montelukast are not clear but are believed to be, in part, because of genetic variability. METHODS: To examine the associations between polymorphisms in candidate genes in the leukotriene pathway and outcomes in patients with asthma on montelukast for 4-8 weeks, we evaluated the changes in peak expiratory flow (PEF), forced expiratory volume in 1 s (FEV(1·0) ) and patients' subjective symptom before and after montelukast treatment. DNA was collected from 252 Japanese participants. RESULTS AND DISCUSSION: Two single-nucleotide polymorphisms (SNPs) in the ALOX5 (rs2115819) and LTA4H (rs2660845) genes were successfully typed. There was no difference between members of the general population (n = 200) and patients (n = 52) in each genotype frequency. Significant associations were found between SNP genotypes in the LTA4H gene and changes in PEF and FEV(1·0) . The PEF and FEV(1·0) responses to montelukast in the A/A genotypes (n = 4) for the LTA4H SNP were significantly higher than those in the G allele carriers (A/G+G/G) (n = 17). WHAT IS NEW AND CONCLUSION: Despite the small sample size, our results suggest that genetic variation in leukotriene pathway candidate genes contributes to variability in clinical responses to montelukast in Japanese patients with asthma.

[Effects of octreotide acetate on intractable chylothorax after surgery for congenital heart diseases].

We experienced 2 infants in whom octreotide acetate was effective on intractable chylothorax after surgery for congenital heart diseases. They were 8- and 5-month-old. They were diagnosed as having corrected transposition of the great arteries (TGA) and tetralogy of Fallot respectively, and underwent bidirectional Glenn anastomosis and right modified Blalock Taussig shunt. Chylothorax was revealed on the 11th and the 1st postoperative day, and was not improved by any conventional therapy in either case. Then octreotide acetate was infused continuously with 0.1-0.6 micorg/kg/hour for 24 and 7 days. Chylothorax disappeared completely without any complications such as disturbance of blood sugar level or growth retardation. Octreotide acetate was effective and safe even in infants in intractable chylothorax after surgery for congenital heart diseases, as long as used for short period.

[Effects of additional pulmonary blood flow after bidirectional Glenn procedure].

Thirteen cases of functional single ventricle who had undergone bidirectional Glenn procedure were divided into 2 groups according to presence (5) or absence (8) of additional pulmonary blood flow. Additional flow was preserved in cases with relatively small pulmonary artery index (PA index), and their sources were antegrade pulmonary blood flow (2), and Blalock-Taussig (BT) shunt (3). In the control group, PA index was reduced to about 70% of the preoperative value, while in the additional group, pulmonary artery growth was recognized without significant elevation of mean pulmonary artery pressure. However, atrioventricular valve regurgitation progressed and systemic ventricular volume did not decrease after Glenn in the additional group. Therefore special consideration for the timing of Fontan procedure is mandatory.

[Staged surgical palliations for hypoplastic left heart syndrome with poor preoperative conditions].

A 2.8 kg-female newborn diagnosed as hypoplastic left heart syndrome was transferred to our hospital after resuscitation against systemic circulatory failure due to closure of the ductus arteriosus. Her systemic circulation was stabilized after alprostadil (lipo-PGE1) and inotorpic agent infusion along with mechanical ventilation support. On admission, signs of a pulmonary high-flow and low systemic perfusion were evident. Impaired coagulation aspect was gradually noted. Because a surgical palliation with cardiopulmonary bypass was considered to be at high-risk, a bilateral pulmonary artery banding was indicated. Through a median sternotomy, the right and left pulmonary arteries were individually banded. The patient was continued on the same ventilation strategy. Cardiac, hepatic and renal dysfunctions were improved over next few days and the patient weaned from ventilatory support. She underwent combined Norwood stage I and II repair at 4 months of age with weight of 4.8 kg. Postoperative course has been uneventful and the patient is now followed up in preparation for Fontan operation.

[Comparison of right ventricular function between prevention and enlargement of pulmonary valve annulus after repair of tetralogy of Fallot; mid-term results].

Total of 41 patients with tetralogy of Fallot (TOF) who underwent intracardiac repair from 1993 to 1998 were divided into 2 groups: preservation (n = 14) or enlargement (n = 27) of the pulmonary valve annulus. The procedure was decided on the Z value of the annular size: above or under -2 SD of the standard value. Although postoperative right ventricular (RV) diastolic volume (RVEDV) and cardiothoracic ratio (CTR) were larger than the preservation group and pulmonary regurgitation (PR) existed in the enlargement group, RV pressure was decreased and central venous pressure (CVP) was low and RV contraction was preserved. The exercise capacity was also good and no significant arrhythmia was recognized. Our mid-term results showed that appropriate enlargement of the pulmonary valve annulus preserved good RV function in patients with TOF.

[Blalock-Taussig shunt and pulmonary artery angioplasty for isolated unilateral absence of the right pulmonary artery; report of a case].

A 7-month-old girl was referred to us for further examination of absence of the right pulmonary artery. She had no symptom at that time. Diagnosis was made by chest computed tomography (CT) and cardiac catheterization. Though the size of the right pulmonary artery was not apparent, right pulmonary vein wedge angiography revealed the distal portion of right pulmonary artery sufficient for surgical repair. But the distance between the pulmonary trunk and right pulmonary artery was too far to perform direct anastomosis, and some systemic collaterals had already been recognized. Pulmonary vasculature was also not inadequate. Therefore we planned a palliative procedure. At the age of 7 months, right modified Blalock-Tausig shunt using 5mm expand-polytetrafluoroethylene (ePTFE) tube and angioplasty of the distal portion of right pulmonary artery using autologous pericardium roll with Dacron mesh was performed. Postoperative course was uneventful. She has been followed up for 6 months after the palliation. In the near future the completion of the definitive repair will be considered.

[Sutureless technique for oozing type postinfarction left ventricular free wall rupture].

We report our experience using a sutureless technique for oozing type postinfarction left ventricular free wall rupture. Several materials such as fibrin seat, autologous or heterologous pericardial patch, fibrin glue, and geratin-resorcin-formaldehyde (GRF) glue have been used. Nine patients, who developed postinfarction left ventricular free wall rupture, underwent surgical repair using a sutureless technique between 1999 and 2004. All patients survived and discharged our hospital without any postoperative complications. And all are alive an exellent condition in 5 to 44 months. A sutureless technique for the treatment of oozing type postinfarction left ventricular free wall rupture is simple, effective, and associated with a favorable outcome.

[Congenital supravalvular aortic stenosis; report of a case].

We experienced a successful surgical case of extended aortoplasty by means of Doty's method (two sinus reconstruction) for congenital supravalvular aortic stenosis (SAS). Case was 12-year-old boy, who had no complaint except heart murmur. The retrograde aortography demonstrated localized stenosis just above the aortic valve, and it was an hour-glass type. The preoperative peak systolic pressure gradient between the left ventricle and ascending aorta was 56 mmHg, which was improved postoperatively. This case showed excellent results. Doty's aortoplasty was favorable method for SAS without deformity of aortic valve and coronary obstruction.

[Repair for atrioventricular valve regurgitation using autologous pericardium: report of a case].

A 13-year-old boy with [SLL] single left ventricle first underwent ventricular septation using a dacron patch at 3 years of age. Eight years after the first surgery, he presented with general fatigue on exertion as the chief complaint. Right-sided atrioventricular valve regurgitation, and dilatation of the right heart were diagnosed. Eleven years after surgery, right heart failure was uncontrollable by medicine, and 2nd surgery was performed. At operation, the right-sided heart valve leaflet was tightly adherent to the dacron septation patch, and valve plasty was judged impossible. We repaired the right-sided atrioventricular valve using an autologous pericardial valve leaflet and sub-valvular tissue. The postoperative course was uneventful, and he has been free from any complication for 33 months.

[A case report of ross operation and ventricular septal defect closure following correction of type A interruption by modified Blalock-Park, pulmonary artery banding and patent ductus arteriosus division].

A 2-year-old boy who had undergone a correction of a type A interruption using a modified Blalock-Park operation, pulmonary artery banding and the division of a patent ductus arteriosus, underwent a Ross operation and closure of ventricular septal defect (VSD). Although a pre-operative echo cardiogram revealed a bicuspid aortic valve, and a Doppler echocardiogram showed only 10 mmHg of pressure gradient across the aortic valve, Ross procedure was performed as a procedure accompanying the closure of a total conus VSD. The total conus VSD was closed with a Dacron patch using pledget mattress sutures. In addition, a running suture was applied over the denuded aortic root and the cranial margin to achieve water tight closure. An aortic root replacement procedure was our first choice for the Ross operation. After both coronary buttons were re-implanted into pulmonary sinuses, a pulmonary artery autograft was wrapped around by the remaining aortic wall for reinforcement to prevent future dilatation. The main pulmonary artery was reconstructed using a bicuspid pericardial valve conduit with a diameter of 24 mm. A post-operative echocardiogram showed no neoaortic valve regurgitation, good coaptation of tri-leaflets, mild regurgitation of pericardial valve and good cardiac performance.

[A modified Fontan operation in the presence of a supracardiac total anomalous pulmonary venous connection].

We report a case of 2-year-old girl with asplenia syndrome who successfully underwent modified Fontan procedure and concomitant repair of supracardiac total anomalous pulmonary venous connection (TAPVC). The preoperative diagnosis included a common atrioventricular canal (type C), a double outlet right ventricle, a common atrium, common atrioventricular valve regurgitation, pulmonary stenosis, and a bilateral superior vena cava (SVC). Cardiac catheterization revealed a Qp/Qs of 1.3, mean PA pressure of 16 mmHg and an Rp of 1.3. The TAPVC drained to left SVC (LSVC) at a position proximal to the hemiazygos vein with an ostium of 5 mm in diameter. The LSVC was divided distal to its connection to the common pulmonary vein (CPV). The TAPVC ostium was cut back into the CPV, then it was anastmosed with posterior aspect of the atrial wall in an effort to provide a wide anastomosis. The postoperative course was uneventful and the patient was discharged from hospital on the 35th postoperative day.

nhaG Na(+)/H(+) antiporter gene of Bacillus subtilis ATCC9372, which is missing in the complete genome sequence of strain 168, and properties of the antiporter.

We cloned a gene which enabled Escherichia coli mutant host cells lacking all of the major Na(+)/H(+) antiporters to grow in the presence of 0.2 M NaCl from chromosomal DNA of Bacillus subtilis ATCC9372. An Na(+)/H(+) antiport activity was observed with membrane vesicles prepared from E. coli cells possessing the cloned gene, but not with vesicles from the host cells. Lithium ion was also a substrate for the antiporter. We sequenced the cloned DNA and found one open reading frame (designated nhaG) preceded by a promoter-like sequence and a Shine-Dalgarno sequence, and followed by a terminator-like sequence. The deduced amino acid sequence of NhaG suggested that it consisted of 524 residues and that the calculated molecular mass was 58.1 kDa. None of the bacterial Na(+)/H(+) antiporters so far reported, except NhaP of Pseudomonas aeruginosa and SynNhaP (NhaS1) of Synechocystis sp., showed significant sequence similarity with the NhaG. However, the NhaP, the SynNhaP, animal NHEs (Na(+)/H(+) exchangers), and some hypothetical Na(+)/H(+) antiporters of several organisms showed significant sequence similarities with the NhaG. Interestingly, the entire DNA region corresponding to the nhaG gene is missing in the reported complete genome sequence of B. subtilis strain 168. We detected a band that hybridized with the nhaG DNA in chromosomal DNA from B. subtilis ATCC9372 but not with that from strain 168. The missing DNA region (1,774 base pairs) is sandwiched by two identical sequences, TTTTCTT.

[Case report of CABG for progressive coronary artery stenosis after 22-year history of Kawasaki disease].

More than 30 years has passed since Kawasaki disease was recognized as an independent disease entity, but the cardiovascular complications of Kawasaki disease are still not well known. We report an 22-year-old woman who underwent triple coronary artery bypass grafting because of a coronary artery aneurysm and multiple coronary artery stenoses, 22 years after the diagnosis of Kawasaki disease. A 2 cm coronary artery aneurysm due to Kawasaki disease was diagnosed when she was 10 years old, when she first presented with the symptom of dyspnea on effort. Since then, she was followed at the outpatient clinic. When she was 19 years old, the first coronary catheterization was performed. Two years later, the second coronary catheterization revealed progression of coronary artery disease. Therefore, coronary artery bypass grafting was performed. This case is rare from the point of view of long-term progression of coronary artery disease.

[A case of renal cell carcinoma producing alpha-fetoprotein].

Renal cell carcinoma (RCC) producing alpha-fetoprotein (AFP) is a rare condition with only 11 cases reported in Japan to our knowledge. A 69-year-old man was admitted to our hospital for further examination of an incidental right renal tumor. Laboratory tests showed markedly increased serum level of AFP whereas both HBs antigen and anti-HCV antibody were negative. Computed tomography and magnetic resonance imaging imagings showed a right renal tumor but no tumor in liver, testis or lymph node. We performed right radical nephrectomy. Serum level of AFP declined within the normal range 7 weeks after nephrectomy according to its half-life curve. The tumor specimen was composed mainly of granular cells. Immunohistochemical examination of the tumor cells proved the presence of AFP in the cytoplasm. The possibility of AFP as a tumor marker of renal cell carcinoma in this case was presented.

Double switch operation for superior-inferior ventricles.

Superior-inferior ventricles are a rare cardiac malformation characterized by the two ventricles lying one above the other instead of side by side. Consequently, the interventricular septum that separates such ventricles is horizontal, and anomalies of the atrioventricular valves and the ventriculoarterial relations are almost always present. This complex anomaly is difficult to manage with an operation, so few cases have been reported. We describe a successful experience in which we performed a double switch operation, consisting of the Senning and Jatene procedures, for this rare malformation accompanied by double-outlet right ventricle [S,L,L]. This is the first report we have been able to locate of a double switch operation for superior-inferior ventricles.

Optimal timing of administration of hyperthermia in combined radioimmunotherapy.

Local hyperthermia (HT) may enhance the efficacy of radioimmunotherapy (RIT). However, the optimal timing of HT relative to administration of antibody is unknown. Human colon cancer xenografts (290 +/- 26 mm3) were treated with 4.63 MBq 131I-A7 monoclonal antibody (MAb) anti-Mr 45,000 glycoprotein antigen on colorectal cancer, and HT at 43 degrees C for 1 h was administered at: (A), 2 days after the 131I-A7 injection at the maximum 131I-A7 tumor accumulation (radiation); (B), soon after the 131I-A7 injection aiming to increase the tumor accumulation of 131I-A7 due to HT vascular effects; or (C), 2 days before the 131I-A7 injection in an attempt at injecting 131I-A7 when increased antigen expression could be expected. Specific growth delay (SGD) of tumors was calculated as (Tqtreat-Tqcontrol)/Tqcontrol where Tq was tumor quadrupling time. The biodistribution and intratumoral distribution of 131I-A7 were investigated to explore the mechanism of tumor response among the different HT regimens. HT alone produced some antitumor effect (SGD 1.90 +/- 0.26), which was less effective than RIT (3.11 +/- 0.50). HT soon after 131I-A7 RIT (B) significantly enhanced RIT efficacy (6.57 +/- 0.51, p < 0.0001) whereas neither HT at 2 days after RIT (A) nor at 2 days before RIT (C) did so. Biodistribution study revealed that HT soon after RIT (B) increased the tumor radiation absorbed dose by a factor of 2.4, while HT after RIT (A) did not increase radiation dose and HT before RIT (C) decreased it. Radioluminograms of tumor sections indicated that HT soon after RIT (B) improved the uniformity of 131I-A7 distribution whereas HT after RIT (A) did not and HT before RIT (C) diminished the uniformity of A7 distribution. In conclusion, the best therapeutic efficacy was obtained when HT was combined soon after the initiation of RIT with 131I-A7. The increased tumor radiation absorbed dose and the uniform intratumoral distribution of 131I-A7 were important factors underlying this improvement, and the additive cytotoxicity of HT is suspected to some extent. HT-induced radiosensitization of tumor was not apparent in this model when HT was given 2 days after 131I-A7 MAb.