[Evaluation of thoracography for secondary pneumothorax in elderly people]

The thoracoscopic surgery for patient with pneumothorax has been considered to be safe and easy. In recent years, there is a growing number of secondary pneumothorax due to advanced pulmonary emphysema in elderly patients. To confirm the existence of adhesion and the site of air leakage are important prior to surgery. In our institution, thoracography was performed before surgery in 9 cases of emphysema and secondary pneumothorax over 60 years old patients. The mean age was 72.2 years old and all patients were male. Air leakage and its site could be identified in 6 cases by thoracography. In the remaining 3 cases, adhesion sites were identified. There were no complications in all cases. The operation time was 117 minutes, and blood loss was 9.9 ml in average. The mean postoperative drainage period was 1.6 days and total hospital stay was 5.9 days. We conclude that the thoracoscopic surgery can be performed more safely by obtaining information of thoracic cavity using thoracography before surgery.

Thermal stability of magnetite (Fe3O4) nanoparticles

Magnetite (Fe3O4) nanoparticles are prime candidates for biomedical applications due to their biocompatibility and good magnetic properties. However, magnetite is highly susceptible to oxidation when exposed to the atmosphere. In order to preserve their properties, it is important for the particles to maintain their magnetite phase. In this study, magnetite nanoparticles were prepared using the conventional co3precipitation of ferrous (Fe2+) and ferric (Fe3+) chloride salt solutions with sodium hydroxide (NaOH). Thermogravimetric analysis (TGA) was subsequently carried out to identify the transition temperatures. Energy Dispersive X3Ray (EDX) spectrum shows the presence of impurities, such as sodium (Na) and chloride (Cl) ions in the as3synthesized magnetite nanoparticles. The as3synthesized samples were then calcined in a chamber furnace according to TGA data. The calcined samples were next characterised by X3ray Powder Diffraction (XRD), Transmission Electron Microscopy (TEM) and Vibrating Sample Magnetometer (VSM) to determine the changes in phase and magnetic properties of the nanoparticles as a function of different calcination temperatures.

Blockade of AT1 receptors protects the blood-brain barrier and improves cognition in Dahl salt-sensitive hypertensive rats

BACKGROUND

The present study tested the hypothesis that inappropriate activation of the brain renin-angiotensin system (RAS) contributes to the pathogenesis of blood-brain barrier (BBB) disruption and cognitive impairment during development of salt-dependent hypertension. Effects of an angiotensin II (AngII) type-1 receptor blocker (ARB), at a dose that did not reduce blood pressure, were also examined.

METHODS

Dahl salt-sensitive (DSS) rats at 6 weeks of age were assigned to three groups: low-salt diet (DSS/L; 0.3% NaCl), high-salt diet (DSS/H; 8% NaCl), and high-salt diet treated with ARB, olmesartan at 1 mg/kg.

RESULTS

DSS/H rats exhibited hypertension, leakage from brain microvessels in the hippocampus, and impaired cognitive functions, which were associated with increased brain AngII levels, as well as decreased mRNA levels of tight junctions (TJs) and collagen-IV in the hippocampus. In DSS/H rats, olmesartan treatment, at a dose that did not alter blood pressure, restored the cognitive decline, and ameliorated leakage from brain microvessels. Olmesartan also decreased brain AngII levels and restored mRNA expression of TJs and collagen-IV in DSS/H rats.

CONCLUSIONS

These results suggest that during development of salt-dependent hypertension, activation of the brain RAS contributes to BBB disruption and cognitive impairment. Treatment with an ARB could elicit neuroprotective effects in cognitive disorders by preventing BBB permeability, which is independent of blood pressure changes.

Substrate effects on surface morphologies and magnetic properties of nanostructured FePt thin films

The substrate effects on surface morphologies, crystal structures, and magnetic properties of the sputter-deposited FePt thin films on Corning 1737, normal glass, and Si wafer substrates, respectively, were investigated. High in-plane coercivities of 10 kOe were obtained for the air-annealed films on Corning 1737 and Si wafer, where both films similarly have granular-like morphologies. Besides, increasing grain size and surface roughness of all the FePt films with the post-anneal temperature were observed. Moreover, partially separated grains were seen in the film on Si wafer, where the formation of Fe silicides during post-anneal is suspected, in which has enhanced the magnetic ordering.

Glucocorticoids differentially regulate the expression of CRFR1 and CRFR2α in MIN6 insulinoma cells and rodent islets

Urocortin 3 (Ucn 3), member of the corticotropin-releasing factor (CRF) family of peptide hormones, is released from β-cells to potentiate insulin secretion. Ucn 3 activates the CRF type-2 receptor (CRFR2) but does not activate the type-1 receptor (CRFR1), which was recently demonstrated on β-cells. While the direct actions of Ucn 3 on insulin secretion suggest the presence of cognate receptors within the islet microenvironment, this has not been established. Here we demonstrate that CRFR2α is expressed by MIN6 insulinoma cells and by primary mouse and human islets, with no detectable expression of CRFR2β. Furthermore, stimulation of MIN6 cells or primary mouse islets in vitro or in vivo with glucocorticoids (GCs) robustly and dose-dependently increases the expression of CRFR2α, while simultaneously inhibiting the expression of CRFR1 and incretin receptors. Luciferase reporters driven by the mouse CRFR1 or CRFR2α promoter in MIN6 cells confirm these differential effects of GCs. In contrast, GCs inhibit CRFR2α promoter activity in HEK293 cells and inhibit the expression of CRFR2β in A7r5 rat aortic smooth muscle cells and differentiated C2C12 myotubes. These findings suggest that the GC-mediated increase of CRFR2α depends on the cellular context of the islet and deviates from the GC-mediated suppression of CRFR1 and incretin receptors. Furthermore, GC-induced increases in CRFR2α expression coincide with increased Ucn 3-dependent activation of cAMP and MAPK pathways. We postulate that differential effect of GCs on the expression of CRFR1 and CRFR2α in the endocrine pancreas represent a mechanism to shift sensitivity from CRFR1 to CRFR2 ligands.

Mechanisms underlying ketamine-induced synaptic depression in rat hippocampus-medial prefrontal cortex pathway

The non-competitive N-methyl-D-aspartate NMDA receptor antagonist ketamine, a dissociative anesthetic capable of inducing analgesia, is known to have psychotomimetic actions, but the detailed mechanisms remain unclear because of its complex properties. The present study elucidated neural mechanisms of the effect of ketamine, at doses that exert psychotomimetic effects without anesthetic and analgesic effects, by evaluating cortical synaptic responses in vivo. Systemic administration (i.p.) of low (1 and 5 mg/kg), subanesthetic (25 mg/kg) and anesthetic (100 mg/kg) doses of ketamine dose-dependently decreased hippocampal stimulation-evoked potential in the medial prefrontal cortex (mPFC) in freely moving rats. The behavioral analysis assessed by prepulse inhibition (PPI) of acoustic startle response showed that ketamine (5 and 25 mg/kg, i.p.) produced PPI deficit. Thus, the psychotomimetic effects observed in ketamine-treated groups (5 and 25 mg/kg, i.p.) are associated with the induction of synaptic depression in the hippocampus-mPFC neural pathway. Based on these results, we further examined the underlying mechanisms of the ketamine-induced synaptic depression under anesthesia. Ketamine (5 and 25 mg/kg, i.p.) caused increases in dialysate dopamine in the mPFC in anesthetized rats. Moreover, the ketamine-induced decreases in the evoked potential, at the dose 5 mg/kg which has no anesthetic and analgesic effects, were indeed absent in dopamine-lesioned rats pretreated with 6-hydroxydopamine (6-OHDA; 150 μg/rat, i.c.v.). Ketamine (5 mg/kg, i.p.)-induced synaptic depression was blocked by pretreatment with dopamine D1 receptor antagonist SCH 23390 (10 μg/rat, i.c.v.) but not dopamine D2 receptor antagonist haloperidol (1.5 mg/kg, i.p.), suggesting that dopaminergic modulation mediated via D1 receptors are involved in the synaptic effects of ketamine. Furthermore, ketamine (5 mg/kg, i.p.)-induced synaptic depression was prevented also by GABAA receptor antagonist bicuculline (0.2 or 2 μg/rat, i.c.v.). These findings suggest that ketamine at the dose that exerts psychotomimetic symptoms depresses hippocampus-mPFC synaptic transmission through mechanisms involving dopaminergic modulation mediated via D1 receptors, which may lead to a net augmentation of synaptic inhibition mediated via GABAA receptors.

GRIP1 enhances estrogen receptor alpha-dependent extracellular matrix gene expression in chondrogenic cells

OBJECTIVE

The role of postmenopause on the pathogenesis of cartilage degeneration has been an open question. We assessed cartilage degeneration in estrogen receptor (ER)alpha null mice and examined the role of glucocorticoid receptor-interacting protein 1 (GRIP1) in the ERalpha-dependent transcription of a type II collagen gene (col2a1) with special reference to a crosstalk with the transforming growth factor (TGF)-beta signaling pathway.

METHODS

The vertebral cartilaginous endplate from female ERalpha null mice was subjected to histological analyses. Col2a1 expression of primary chondrocytes (PCs) obtained from ERalpha null mice after 17beta-estradiol (E(2)) and TGF-beta1 stimulation was examined by reverse transcription polymerase chain reaction (RT-PCR). Estrogen response element (ERE) or col2a1 promoter-enhancer luciferase reporter system was used to investigate the crosstalk among ERalpha, GRIP1, and MKK6. Col2a1 expression and glycosaminoglycan (GAG) content were measured in ATDC5 cells treated with GRIP1 small interfering RNA (siRNA).

RESULTS

ERalpha deficiency clearly accelerated impairment of the vertebral cartilaginous endplate. E(2) and TGF-beta1 stimulation increased col2a1 expression in PC from wild-type mice, but not that from ERalpha null mice. The same stimulation increased the col2a1 promoter-enhancer reporter activity, and the elevated activity was decreased by dominant-negative ERalpha and p38 mitogen-activated protein kinase (MAPK) inhibitor. GRIP1 increased the E(2)-dependent ERE activation in the presence of ERalpha and constitutive-active MKK6. GRIP1 siRNA repressed col2a1 expression and GAG production in ATDC5 cells.

CONCLUSIONS

Crosstalks between ERalpha/GRIP1 and TGF-beta/MKK6/p38 MAPK pathway have protective roles on cartilage metabolism via regulating the extracellular matrices expression. The finding may lead to the development of a novel therapeutic approach for cartilage degeneration.

Early stress exposure impairs synaptic potentiation in the rat medial prefrontal cortex underlying contextual fear extinction

Traumatic events during early life may affect the neural systems associated with memory function, including extinction, and lead to altered sensitivity to stress later in life. We recently reported that changes in prefrontal synaptic efficacy in response to extinction trials did not occur in adult rats exposed to early postnatal stress (i.e. footshock [FS] stress during postnatal day 21-25 [3W-FS group]). However, identifying neurocircuitry and neural mechanisms responsible for extinction retrieval after extinction training have not been precisely determined. The present study explored whether synaptic transmission in the hippocampal-medial prefrontal cortex (mPFC) neural pathway is altered by extinction retrieval on the day after extinction trials using electrophysiological approaches combined with behavioral analysis. We also elucidated the effects of early postnatal stress on the synaptic response in this neural circuit underlying extinction retrieval. Evoked potential in the mPFC was enhanced following extinction retrieval, accompanied by reduced freezing behavior. This synaptic facilitation (i.e. a long-term potentiation [LTP]-like response) did not occur; rather synaptic inhibition was observed in the 3W-FS group, accompanied by sustained freezing. The behavioral deficit and synaptic inhibition observed in the 3W-FS group were time-dependently ameliorated by the partial N-methyl-D-aspartate (NMDA) receptor agonist D-cycloserine (15 mg/kg, i.p.). These findings suggest that the LTP-like response in the hippocampal-mPFC pathway is associated with extinction retrieval of context-dependent fear memory. Early postnatal stress appears to induce neurodevelopmental dysfunction of this neural circuit and lead to impaired fear extinction later in life. The present data indicate that psychotherapy accompanied by pharmacological interventions that accelerate and strengthen extinction, such as d-cycloserine treatment, may have therapeutic potential for the treatment of anxiety disorders, including posttraumatic stress disorder.

High incidence of fatty liver and insulin resistance in long-term adult survivors of childhood SCT

Overweight/obesity among adult survivors of childhood SCT has been considered to be predictive of eventual development of metabolic abnormalities. Fatty liver is increasingly recognized as a major cause of liver-related morbidity and mortality in the general population. However, the real incidence of fatty liver in adult survivors of SCT has not been fully elucidated. We determined whether adult survivors are at risk for overweight/obesity, metabolic abnormalities and fatty liver and whether these risks are associated with cranial radiotherapy (CRT) before SCT. Among the 51 patients (30 males), only two male patients were overweight/obese at the last evaluation. On the other hand, 9 male (30%) and 15 female (71%) patients were underweight. Fatty liver was diagnosed in 11 male (37%) and 10 female (48%) patients during the follow-up period, although patients who had fatty liver did not tend to be overweight/obese. Significantly more patients who received CRT before SCT developed fatty liver with insulin resistance than those who did not (P<0.05). Even patients who are not overweight/obese may develop fatty liver and metabolic abnormalities. We recommend that healthcare professionals recognize these risks and give life-long attention to detecting, preventing and treating late complications after SCT.

Microendoscopic resection of lumbar discal cysts

INTRODUCTION

A lumbar discal cyst is a relatively rare cystic lesion that communicates with lumbar intervertebral discs. Surgical resection of the cyst is the reported treatment of choice. In this study, the authors report the minimally invasive surgical resection of lumbar discal cysts using a microendoscopy.

PATIENTS AND METHODS

Seven male patients with lumbar discal cysts underwent microendoscopic resections (mean age: 25.1+/-3.2 years and the mean follow-up period: 27.9 months). During the surgeries, the cysts were subtotally resected in a piecemeal fashion, and the fistulas forming the communications between the cysts and the corresponding intervertebral discs were coagulated using a bipolar coagulator.

RESULTS

All the patients obtained relief from their pain after surgery, and no recurrences occurred during a mean follow-up period of 28 months. The mean operation time was 72.6+/-20.2 min, and the mean blood loss was 44.4+/-13.7 grams. No intra- or peri-operative complications were noted in any of the patients.

CONCLUSIONS

Microendoscopic resection appears to be a minimally invasive and feasible surgical option for the treatment of lumbar discal cysts.

Positional relationship between recurrent intracerebral hemorrhage/lacunar infarction and previously detected microbleeds

BACKGROUND AND PURPOSE

Although MBs, ICH, and LI are secondary to cerebral microangiopathy, it remains unclear whether the location of subsequent ICH/LI corresponds to the previous location of MBs. We performed this study to clarify the positional relationship between recurrent ICH/LI and previously detected MBs.

MATERIALS AND METHODS

We evaluated patients with recurrent ICH/LI who had MBs, as shown on prior T2*-weighted MR imaging. We assessed retrospectively whether the location of recurrent ICH/LI corresponded to that of the prior MB. Patients with ICH were divided into the deep ICH group and the lobar ICH group, and the positional relationship between hematoma and previously detected MBs was evaluated.

RESULTS

A total of 55 patients, including 34 with recurrent ICH and 21 with recurrent LI were evaluated. Although the location of the LI corresponded to prior MBs in only 1 patient (4.8%), the location of ICH corresponded to prior locations of MBs in 21 patients (61.8%) (OR, 32.3; 95% CI, 3.86-270.3; P < .001). Among the patients with ICH, the correspondence ratio was higher in the deep ICH group (19 of 24 patients, 79.2%) than in the lobar ICH group (2 of 10 patients, 20%) (OR, 15.2; 95% CI, 2.42-95.3; P < .002).

CONCLUSIONS

The close positional association between recurrent ICH and prior MBs suggests that MBs represent hemorrhage-prone microangiopathy. In addition, different correspondence ratios between the deep ICH group and the lobar ICH group may be attributable to their different pathogenesis.

A Novel Therapeutic and Prophylactic Vaccine (HVJ-Envelope / Hsp65 DNA + IL-12 DNA) against Tuberculosis Using the Cynomolgus Monkey Model

We have developed a novel tuberculosis (TB) vaccine; a combination of the DNA vaccines expressing mycobacterial heat shock protein 65 (HSP65) and interleukin 12 (IL-12) delivered by the hemagglutinating virus of Japan (HVJ)-envelope and -liposome (HSP65 + IL-12/HVJ). An IL-12 expression vector (IL-12DNA) encoding single-chain IL-12 proteins comprised of p40 and p35 subunits were constructed. This vaccine provided remarkable protective efficacy in mouse and guinea pig models compared to the BCG vaccine on the basis of C.F.U of number of TB, survival, an induction of the CD8 positive CTL activity and improvement of the histopathological tuberculosis lesions. This vaccine also provided therapeutic efficacy against multi-drug resistant TB (MDR-TB) and extremely drug resistant TB (XDR-TB) (prolongation of survival time and the decrease in the number of TB in the lung) in murine models. Furthermore, we extended our studies to a cynomolgus monkey model, which is currently the best animal model of human tuberculosis. This novel vaccine provided a higher level of the protective efficacy than BCG based upon the assessment of mortality, the ESR, body weight, chest X-ray findings and immune responses. All monkeys in the control group (saline) died within 8 months, while 50% of monkeys in the HSP65+hIL-12/HVJ group survived more than 14 months post-infection (the termination period of the experiment). Furthermore, the BCG priming and HSP65 + IL-12/HVJ vaccine (booster) by the priming-booster method showed a synergistic effect in the TB-infected cynomolgus monkey (100% survival). In contrast, 33% of monkeys from BCG Tokyo alone group were alive (33% survival). Furthermore, this vaccine exerted therapeutic efficacy (100% survival) and augmentation of immune responses in the TB-infected monkeys. These data indicate that our novel DNA vaccine might be useful against Mycobacterium tuberculosis including XDR-TB and MDR-TB for human therapeutic clinical trials.

Molecular characterization of Streptococcus mutans strains containing the cnm gene encoding a collagen-binding adhesin

OBJECTIVE

Streptococcus mutans, known to be a major pathogen of dental caries, is also considered to cause infective endocarditis. Its 120-kDa Cnm protein binds to type I collagen, which may be a potential virulence factor. In this study, we characterized S. mutans clinical strains focusing on the cnm gene encoding Cnm.

DESIGN

A total of 528 S. mutans strains isolated from Japanese, Finnish, and Thai subjects were investigated. Using molecular techniques, the distribution frequency of cnm-positive strains and location of the inserted cnm were analyzed. Furthermore, isogenic mutant strains were constructed by inactivation of the cnm gene, then their biological properties of collagen-binding and glucan-binding were evaluated. Southern hybridization of the genes encoding glucan-binding proteins was also performed.

RESULTS

The distribution frequency of cnm-positive strains from Thai subjects was 12%, similar to that previously reported for Japanese and Finnish subjects. Furthermore, the location of insertion of cnm was the same in all cnm-positive clinical isolates. As for the cnm-inactivated mutant strains constructed from 28 clinical isolates, their collagen-binding activity was negligible. In addition, glucan-binding activity in the cnm-positive clinical isolates was significantly reduced and corresponded to a lack of gbpA encoding glucan-binding protein A.

CONCLUSIONS

Our results indicate that strains with cnm genes, the most crucial factor for the collagen-binding property of S. mutans, are detectable at similar frequencies over several different geographic locations. In addition, the common properties of these strains are a high level of collagen-binding activity and tendency for a low level of glucan-binding activity.

The threshold for definition of impaired fasting glucose in a Japanese population

AIMS

We examined whether the cut-off value of fasting plasma glucose (FPG) for diagnosing impaired fasting glucose (IFG) should be lowered, using data from a large Japanese population.

METHODS

A retrospective cohort study was conducted from 1998 to 2006. Follow-up (2002-2006) data were merged with baseline (1998-2002) data, yielding 11 129 persons who had participated on both occasions. Among these, 10 475 persons who did not have diabetes (known diabetes or defined as FPG > or = 7.0 mmol/l) or suspected diabetes (glycated haemoglobin > or = 6.4%) were analysed.

RESULTS

During follow-up of an average of 5.4 years, 279 (5.2%) out of 5372 men and 98 (1.9%) out of 5103 women developed diabetes. According to the three baseline FPG categories (< 5.6, 5.6-6.1 and 6.2-6.9 mmol/l), 28/3401 (0.8%), 91/1456 (6.3%) and 160/515 (31.1%), respectively, in men and 13/4231 (0.3%), 30/695 (4.3%) and 55/177 (31.1%), respectively, in women developed diabetes. The optimal cut-off FPG value to predict diabetes was 5.7 mmol/l for both men (sensitivity 84.2%, specificity 76.9%) and women (81.6%, 91.0%). However, lowering the cut-off from 6.1 to 5.7 mmol/l increased the prevalence of IFG 2.7-fold in men and 3.0-fold in women. Lowering the value further to 5.6 mmol/l increased the prevalence of IFG 3.8-fold in men and 4.9-fold in women.

CONCLUSIONS

It may be reasonable to retain the conventional lower FPG limit for IFG and treat FPG values of 5.6-6.1 mmol/l as non-diabetic hyperglycaemia, considering the four- to fivefold increase in individuals classified as IFG when the new cut-off is applied.

[Aortic valve replacement and hemiarch replacement in a patient with a porcelain aorta]

We report a case of aortic valve replacement and hemiarch replacement with reconstruction of the brachiocephalic artery in a patient with a porcelain aorta. A 65-year-old man was admitted to the hospital for aortic stenosis. Computed tomography demonstrated severe aortic calcification and extensive calcification covering a wide area of the aorta. The echocardiography showed a highly calcified aortic valve and a pressure gradient of 109 mmHg across the aortic valve. At surgery, calcification of the ascending aorta was severe and involved its entire circumference. Therefore, 2 cannulae were inserted to the right axillary and right femoral arteries for extracorporeal circulation. We performed replacement of the ascending aorta and hemiarch with reconstruction of the brachiocephalic artery under circulatory arrest and antegrade cerebral perfusion, as well as aortic valve replacement with a 21 mm St. Jude Medical mechanical valve. He had no major cardiac complications during the postoperative course, and was discharged on postoperative day 33.

A pilot phase I/II study of combination chemotherapy with nafamostat mesilate and gemcitabine for unresectable pancreatic cancer

e15600

Background: To improve chemoresistance of gemcitabine (GEM) caused by GEM-induced nuclear factor kappa B (NF- κB) activation, we have conducted combination chemotherapy of GEM with NF-κB inhibitor, nafamostat mesilate (NAM) which is commercially approved as an effective therapeutic agent for disseminated intravascular coagulation, systemic response syndrome, or pancreatitis in Japan for patients with unresectable pancreatic cancer patients through phase 1/2 study. Methods: Study treatment consists of GEM 1,000 mg/m2 on d 8, 15 and 22 plus NAM 2.4∼4.8 mg/kg on d 8, 15 and 22. NAM was administered intra-arterially by continuous regional infusion for 24 hours via an infusion port system one hour before administration of GEM. Overall survival, response rate (RECIST), serum CA19–9 and clinical benefit response (body weight, pain alleviation) were assessed. Results: Between Feb 2007 and Oct 2008, 20 patients with unresectable pancreatic cancer were included in this study. Pts characteristics: male/female: 18/2, median age 63.5 (range 38–79) yrs, median Karnofsky PS 80% (range 70–90%), stage III/IV: 8/12, serum CA19–9 4,662 U/ml (range 88–32,100), baseline visual analogue scale 0–1/2–4/5–7/8–10; 9/4/7/0, baseline analgesic consumption (morphine-equivalent, mg/day) 0/10–100/100>; 10/7/3. The combination of NAM with GEM is well tolerated and MTD has not been reached. The recommended dose was GEM 1,000 mg/m2; NAM 4.8 mg/kg. Overall survival was 8.0 (range 4.7–17) months. CR/PR/NC/PD/not evaluated; 0/3/14/2/1. Serum CA19–9 reduction rate; 89%. Three pts. could become off and 1pt. could reduce oral morphine sulfate, and 5 pts. gained weight. Conclusions: The GEM/NAM regimen is safe, and the clinical data, including overall survival and clinical benefit response, suggest that the initial clinical outcome of this trial has been encouraging. An expanded cohort of the combination chemotherapy is underway.

No significant financial relationships to disclose.

[Aortic valve replacement and repeat coronary artery bypass grafting in a patient with a patent internal thoracic artery bypass graft; report of a case]

We report a case of aortic valve replacement and repeat coronary artery bypass grafting in a patient with a patent internal thoracic artery bypass graft. A 77-year-old man, who underwent coronary artery bypass grafting (CABG) 10 years ago, was admitted to the hospital for aortic stenosis and angina pectoris. Transthoracic echocardiography demonstrated severe aortic calcification with an 86 mmHg gradient across the aortic valve. Coronary angiography demonstrated the patency of all grafts and 90% stenosis of the left circumflex coronary artery. At surgery, a full median sternotomy was performed. The adhesions around the heart and great vessels were severe and the left internal thoracic artery (LITA) was found adherent to the heart and sternum. The LITA and saphenous vein graft (SVG) graft were dissected carefully. Retrograde coronary sinus (CS) perfusion was performed with antegrade myocardial protection for cardiac arrest. We performed aortic valve replacement (AVR) with a 17 mm St. Jude Medical Regent Valve and CABG to the circumflex artery with the saphenous vein under cardiopulmonary bypass. His postoperative course was uneventful. He was discharged from our hospital without major complications.

Identification of the clonal complexes of Staphylococcus aureus strains by determination of the conservation patterns of small genomic islets

AIMS

To investigate the clonality of Staphylococcus aureus isolates, it is important to identify their clonal complexes (CCs) with multilocus sequence typing (MLST). However, it is expensive to carry out MLST analyses for many isolates. The aim of this study, therefore, was to develop a cost-effective method to identify CCs by determining the conservation pattern of 'small genomic islets' (SGIs). SGIs are nonconserved regions between strains and have single or multiple open-reading frames (ORFs).

METHODS AND RESULTS

The whole-genome sequences of nine strains were compared in order to select 16 SGIs. The conservation patterns of the 16 SGIs (islet patterns) were investigated in 136 S. aureus isolates, which were classified into 21 CCs. The islet patterns (IPs) exhibited a one-to-one correspondence with the CCs, except for isolates belonging to CC1, CC5 and CC8. The IPs typical of strains belonging to CC1, CC5 and CC8 differed between those of sequence type 1 (ST1) and ST188 (CC1), ST5 and ST6 (CC5) and ST8 and ST239 (CC8).

SIGNIFICANCE AND IMPACT OF THE STUDY

The CCs of many isolates can be identified in an easy and inexpensive manner by detecting these 16 SGIs. Emergent clones, particularly methicillin-resistant ones, can be identified by examining numerous islets by IP analysis.

[Recurrent cardiac myxoma that developed rapidly in a short period]

A 55-year-old woman, who had undergone extirpation of left atrial myxoma 3-years before, was admitted to our hospital with dyspnea. Chest computed tomography revealed a low density mass in the left atrium (LA) with a diameter of 54 mm. Transthoracic echocardiography showed that the mass was attached to the left atrial septal wall and had a pendulum-like movement. We urgently performed an operation for recurrent left atrial myxoma. Through atrial transseptal approach, a huge myxomatus tumor was observed in the LA. The stalk was on the endocardium at the cranial side of the previous autologous pericardial patch. The tumor was completely excised along with the patch. We repaired the disrupted endocardium and performed Dacron patch repair of the atrial septal defect. The patient recovered uneventfully and was discharged 14 days after surgery. The excised tumor was found to be myxoma on pathological examination similar to the previous tumor. We report a case of recurrent left atrial myxoma with rapid growth in a short time period.

Distribution of tenascin-C, fibronectin and collagen types III and IV during regeneration of rat submandibular gland

The aim of this study was to determine the localization of tenascin-C, fibronectin and collagen types III and IV during regeneration of the rat submandibular gland. After 7 days' obstruction, the regenerating glands were collected at days 0, 1, 3, 5, 7, 11 and 14 after duct release to study regeneration. Immunohistochemical staining revealed that tenascin-C was strongly expressed in the epithelial cells of duct-acinar structures at days 0-3, and down-regulated in its expression from day 5 to 11, though weak expression was detected in the intercalated duct and acinar cells of the normal gland. Strong labeling of fibronectin was detected around duct-acinar structures during days 0-3 of regeneration. Type IV collagen was expressed strongly in the thickened basement membrane of acinar cells and duct-acinar structures during days 0-3, but weakly around large ducts, though type III collagen was expressed at consistent levels. These findings suggest that tenascin-C and fibronectin affect only the duct-acinar structures, and type IV but not type III collagen is involved in the regeneration of acinar cells.

Clinical characteristics of patients with both anti-U1RNP and anti-centromere antibodies

OBJECTIVE

To clarify the clinical characteristics of patients having both anti-U1RNP antibodies (anti-U1RNP) and anti-centromere antibodies (ACA) in comparison to subjects having either anti-U1RNP or ACA alone.

SUBJECTS AND METHODS

One hundred and fifty-six subjects who had anti-U1RNP and/or ACA were enrolled. They were classified into three groups: anti-U1RNP alone group (n = 64); ACA alone group (n = 82); and anti-U1RNP+ACA group (n = 10). The anti-U1RNP alone and ACA alone groups were also divided into the low-titre and the high-titre subgroups, respectively. The frequencies of the specific clinical findings and laboratory data were compared among the groups or subgroups.

RESULTS

The frequencies of persistent proteinuria or lupus nephritis (LN, 50.0%) and primary biliary cirrhosis (PBC, 30.0%) in the anti-U1RNP+ACA group were higher than that in the anti-U1RNP alone group (17.2%, p<0.01; 3.1%, p = 0.075; respectively). The frequencies of systemic lupus erythematosus (SLE, 60.0%), persistent proteinuria or LN (50.0%), anti-Ro (70.0%), and anti-La (30.0%) in the anti-U1RNP+ACA group were higher than those in the ACA alone group (11.0%, p<0.01; 4.9%, p<0.001; 23.2%, p<0.01; and 6.1%, p = 0.085; respectively). The frequency of systemic sclerosis (SSc) in the high-titre subgroup (30.0%) was higher than that in the low-titre subgroup (11.8%) in the anti-U1RNP alone group, without significance (p = 0.072). The frequency of interstitial pneumonia in the high-titre subgroup (26.8%) was higher than that in the low-titre subgroup (2.4%) in the ACA alone group (p<0.01).

CONCLUSIONS

The clinical characteristics of patients with anti-U1RNP+ACA were clarified in comparison to subjects having either anti-U1RNP or ACA alone.

Deconfined criticality: generic first-order transition in the SU(2) symmetry case

Monte Carlo simulations of the SU(2)-symmetric deconfined critical point action reveal strong violations of scale invariance for the deconfinement transition. We find compelling evidence that the generic runaway renormalization flow of the gauge coupling is to a weak first-order transition, similar to the case of U(1) x U(1) symmetry. Our results imply that recent numeric studies of the Nèel antiferromagnet to valence bond solid quantum phase transition in SU(2)-symmetric models were not accurate enough in determining the nature of the transition.

Quantitative assessment of renal cortical echogenicity in clinically normal cats

In this study, we assessed the renal cortical echogenicity of clinically normal adult cats by histogram analysis to obtain basic ultrasonographic data. Ultrasound images were taken under the following sets of conditions: (1) high contrast and low gain setting using a convex probe, (2) low contrast and high gain setting using a convex probe, (3) high contrast and low gain setting using a linear probe and (4) low contrast and high gain setting using a linear probe. Echogenicity of the region of interest (ROI) in the right and left renal cortices, liver and spleen was determined by histogram analysis; kidney/spleen (Kid/Sp) and kidney/liver (Kid/Liv) echogenicity ratios were calculated. Kid/Sp and Kid/Liv values varied among different ROI sites in the kidney when obtained using the convex probe, but were constant when obtained using the linear probe. Kid/Sp measured in the middle sites of the kidney showed similar values for the different settings; however, Kid/Liv differed between probes. The present findings suggest that determination of Kid/Sp using a linear probe is a feasible method for quantitative evaluation of renal cortical echogenicity in cats.

Quantum magnets under pressure: controlling elementary excitations in TlCuCl3

We follow the evolution of the elementary excitations of the quantum antiferromagnet TlCuCl3 through the pressure-induced quantum critical point, which separates a dimer-based quantum disordered phase from a phase of long-ranged magnetic order. We demonstrate by neutron spectroscopy the continuous emergence in the weakly ordered state of a low-lying but massive excitation corresponding to longitudinal fluctuations of the magnetic moment. This mode is not present in a classical description of ordered magnets, but is a direct consequence of the quantum critical point.

Association between cerebral microbleeds on T2*-weighted MR images and recurrent hemorrhagic stroke in patients treated with warfarin following ischemic stroke

BACKGROUND AND PURPOSE

Although accumulating evidence suggests the presence of microbleeds as a risk factor for intracerebral hemorrhage (ICH), little is known about its significance in anticoagulated patients. The aim of this study was to determine whether the presence of microbleeds is associated with recurrent hemorrhagic stroke in patients who had received warfarin following atrial fibrillation-associated cardioembolic infarction.

MATERIALS AND METHODS

A total of 87 consecutive patients with acute recurrent stroke, including 15 patients with ICH and 72 patients with cerebral infarction, were enrolled in this study. International normalized ratios (INRs), vascular risk factors, and imaging characteristics, including microbleeds on T2*-weighted MR images and white matter hyperintensity (WMH) on T2-weighted MR images, were compared in the 2 groups.

RESULTS

Microbleeds were noted more frequently in patients with ICH than in patients with cerebral infarction (86.7% versus 38.9%, P = .0007). The number of microbleeds was larger in patients with ICH than in patients with cerebral infarction (mean, 8.4 versus 2.1; P = .0001). INR was higher in patients with ICH than in patients with cerebral infarction (mean, 2.2 versus 1.4; P < .0001). The frequency of hypertension was higher in patients with ICH than in patients with cerebral infarction (86.7% versus 45.8%, P = .0039). Multivariate analysis revealed that the presence of cerebral microbleeds (odds ratio, 7.383; 95% confidence interval, 1.052-51.830) was associated with ICH independent of increased INR and hypertension.

CONCLUSION

The presence of cerebral microbleeds may be an independent risk factor for warfarin-related ICH, but more study is needed because of strong confounding associations with elevated INR and hypertension.

Microendoscopic discectomy for lumbar disc herniation with bony fragment due to apophyseal separation

The purpose of this study was to elucidate the feasibility of microendoscopic discectomy (MED) for the treatment of lumbar disc herniation with a bony fragment due to apophyseal separation. Eighteen patients with low back pain and unilateral sciatic pain due to lumbar disc herniation with a bony fragment were treated by MED using the unilateral approach (15 males and three females; mean age, of 28.9 years; mean follow-up period, 21.1 months); 18 age-and sex-matched patients with lumbar disc herniation without a bony fragment treated by MED served as the control group. The clinical outcomes were evaluated using the Japanese Orthopedic Association Score for Low Back Pain (JOA scores; maximum score, 29 points). Evaluation of the results revealed that good surgical outcomes equivalent to those in the control group were obtained in the subjects of LDH with a bony fragment (JOA scores; 14.1+/-3.5 in the patient group vs.15.4+/-2.6 in the control group before surgery; 26.3+/-1.8 in the patient group vs. 26.9+/-1.3 at follow-up after the surgery). Although the mean surgical time was significantly longer in the patient group, there were no intra- or postoperative complications in either group. We conclude that MED using the unilateral approach is a feasible minimally invasive surgical option for patients of lumbar disc herniation with an apophyseal bony fragment.

Brainstem in Machado-Joseph disease: atrophy or small size?

Machado-Joseph disease (MJD), one of the most common types of hereditary spinocerebellar degeneration caused by abnormal expansion of the CAG repeat in the MJD1 gene, presents atrophy of the infratentorial structures neuropathologically and neuroradiologically. Although a significant positive correlation has been reported between infratentorial atrophy and the number of expanded CAG repeat units, the exact changing course of brainstem size in the individual case remains to be resolved. We investigated seven cases of genetically confirmed MJD longitudinally by magnetic resonance imaging with observation periods of 4.5-10.6 years. Measurement of the midsagittal areas of infratentorial structures disclosed progressive atrophy of the pontine base and cerebellum, which correlated significantly with age, whilst midbrain and pontine tegmentum showed atrophy with no significant progression, suggesting it was better identified as 'small size' and might have mostly been completed before the initial symptoms. Such differences between regions in atrophy progression must be caused by a difference in the neuropathological course.

Surgical treatment of intramedullary spinal cord tumors: prognosis and complications

STUDY DESIGN

Retrospective case series.

OBJECTIVE

To evaluate our recent treatment strategy for intramedullary spinal cord tumors.

SETTING

Department of Orthopaedic Surgery, Keio University, Japan.

METHODS

We reviewed 68 cases of intramedullary tumors (ependymoma, 33; astrocytoma, 23; hemangioblastoma, 12), treated surgically between 1994 and 2003. There were 42 males and 26 females whose mean age at the time of surgery was 43 years. The mean follow-up period was 6.2 years. The tumor malignancy grade according to the WHO classification was astrocytoma grade I, 3; grade II, 8 (low-grade: 11 cases); grade III, 10; grade IV, 2 (high-grade: 12 cases). All ependymomas were grade II. Three of the 12 hemangioblastomas were associated with von Hippel-Lindau disease.

RESULTS

Total excision was achieved in 90% of the ependymomas and functional improvement was obtained when the preoperative neurological deficit was mild. Approximately 50% of low-grade astrocytomas could be totally excised with favorable survival outcomes, suggesting that total excision should be attempted for low-grade astrocytomas. However, total excision of high-grade tumors was difficult and the functional outcomes were poor. Cordotomy should be considered in patients with a thoracic high-grade astrocytoma. Total resection was possible in 92% of hemangioblastoma, and the functional outcomes were good, however, more attention should be paid for tumors with feeding arteries on the ventral side and for those associated with von Hippel-Lindau disease.

CONCLUSIONS

Predictors of good surgical outcome for intramedullary spinal cord tumors were histological grades of the tumors, surgical margins, and neurological status of the patient before surgery.