Dichloroacetate inhibits the degeneration of decellularized cardiovascular implants

 

OBJECTIVES

Intima hyperplasia is a major issue of biological cardiovascular grafts resulting in progressive in vivo degeneration that particularly decreases the durability of coronary and peripheral vascular bypasses. Previously, dichloroacetate (DCA) has been reported to prevent the formation of hyperplastic intima in injured arteries. In this study, the effect of DCA on the neointima formation and degeneration of decellularized small-caliber implants was investigated in a rat model.

METHODS

Donor rat aortic grafts (n = 22) were decellularized by a detergent-based technique, surface-coated with fibronectin (50 µl ml⁻¹, 24 h incubation) and implanted via anastomoses to the infrarenal aorta of the recipients. Rats in the DCA group (n = 12) received DCA via drinking water during the whole follow-up period (0.75 g l⁻¹), while rats without DCA treatment served as controls (n = 10). At 2 (n = 6 + 5) and 8 (n = 6 + 5) weeks, the grafts were explanted and examined by histology and immunofluorescence.

RESULTS

Systemic DCA treatment inhibited neointima hyperplasia, resulting in a significantly reduced intima-to-media ratio (median 0.78 [interquartile range, 0.51–1.27] vs 1.49 [0.67–2.39] without DCA, P < 0.001). At 8 weeks, neointima calcification, as assessed by an established von Kossa staining-based score, was significantly decreased in the DCA group (0 [0–0.25] vs 0.63 [0.06–1.44] without DCA, P < 0.001). At 8 weeks, explanted grafts in both groups were luminally completely covered by an endothelial cell layer. In both groups, inflammatory cell markers (CD3, CD68) proved negative.

CONCLUSIONS

Systemic DCA treatment reduces adverse neointima hyperplasia in decellularized small-caliber arterial grafts, while allowing for rapid re-endothelialization. Furthermore, DCA inhibits calcification of the implants.

Rupture of aneurysmal coronary-to-pulmonary artery fistula in a 96-year-old female; report of a case

Coronary artery fistula (CAF) is a relatively rare congenital abnormality of the coronary arteries; typically, patients who undergo surgery for CAFs are relatively young because it is a congenital disease. Here we present a case of an aneurysmal coronary-to-pulmonary artery fistula rupture in a 96-year-old female. Considering her extreme high age and missing preoperative diagnostics, only local hemostasis without anatomical repair was performed but the patient is still doing well 1 year after the operation.

The Cause of Massive Hemoptysis After Thoracic Endovascular Aortic Repair May Not Always Be an Aortobronchial Fistula: Report of a Case

Hemoptysis after thoracic endovascular/open aortic repair is relatively rare but a well-known complication, and normally diagnosed with aortobronchial fistula (ABF). Here, we present a patient who suffered from recurrent massive hemoptyses even after multiple thoracic endovascular aortic repairs (TEVARs), where hemoptysis was ultimately controlled by pneumonectomy. In this case, the bleeding source was not the aorta but the lung parenchyma itself, indicating the importance of raising awareness that the cause of massive hemoptysis after TEVAR may not always be an ABF.

Proximalized Total Arch Replacement Can Be Safely Performed by Trainee

BACKGROUND

The aim of the present study was to validate safety of total arch replacement (TAR) using a novel frozen elephant trunk device, operated by trainees as surgical education.

METHODS

Sixty-four patients including 19 patients (29.6%) with acute aortic dissection type A (AADA) underwent TAR in our institute between April 2014 and March 2019 were retrospectively analyzed. Twenty-nine patients were operated by trainees (group T) and 35 patients were operated by attending surgeons (group A).

RESULTS

Patient characteristics did not differ between groups. Operative time (409.4 ± 87.8 vs. 468.6 ± 129.6 minutes, p = 0.034), cardiopulmonary bypass time (177.7 ± 50.4 vs. 222.9 ± 596.7 minutes, p = 0.019), and hypothermic circulatory arrest time (39.5 ± 13.4 vs. 54.5 ± 18.5 minutes, p = 0.001) were significantly shorter in group A than in group T, but aortic clamping time did not differ between groups (115.3 ± 55.7 vs. 114.2 ± 35.0 minutes, p = 0.924) because the rate of concomitant surgery was higher in group A (37.1 vs. 10.3%, p = 0.014). Thirty-day mortality was 3.1% in the entire cohort. Although operation time was longer in group T, there were no significant difference in postoperative results between the groups, and the experience levels of the main operator were not independent predictors for in-hospital mortality + major postoperative complications. There was no difference in late death and aortic events between groups.

CONCLUSIONS

The present study demonstrated that TAR can be safely performed by trainees, and suggests TAR as a possible and safe educational operation.

Extremely small-diameter, high-density, radio frequency, plasma sources and central gas feeding for next-generation electrodeless plasma thrusters

Radio frequency (RF) waves including helicon waves can readily produce high-electron-density (n_e up to 10¹³ cm^-3) plasmas with a broad range of external operating parameters. Various featured RF and helicon sources in a wide range of scales are suitable for plasma propulsion schemes. Electrodeless RF plasmas have no direct contact between electrodes and antennas, which enables long-life operation. However, one of the crucial problems is to reduce the plasma size for future applications in nano- and pico-satellites. Diagnostics of the plasma parameters in a small area should also be improved. Furthermore, to increase plasma performance, it is important to consider the radial electron density (n_e) profile with an increasing upper limit, observed in high-density helicon sources due to the depletion of neutrals. This problem may be controlled by the location of neutral gas feeding and knowledge of the gas pressure distribution. Here, production of RF plasmas, with extremely small diameters from 3-mm down to 0.5-mm including 1-mm, was demonstrated, and characterization of n_e and the electron temperature was performed with a collisional radiative model. Finally, to improve plasma performance such as n_e and the thrust force, internal gas feeding was demonstrated using a developed Pirani gauge to measure neutral density.

Pulmonary artery banding for initial treatment of ventricular septal rupture

Ventricular septal rupture (VSR) is a serious and fatal mechanical complication after acute myocardial infarction. Emergent or urgent, surgical/transcatheter intervention is necessary to treat VSR, though the outcome is not favorable. We performed temporary pulmonary artery banding (PAB) in an 85-year-old man who presented with chest pain to adjust the shunt flow through the VSR, which prevented further pulmonary edema and delayed the timing of surgical repair. There has been no report showing successful PAB performed for VSR after myocardial infarction.

Controlled autologous recellularization and inhibited degeneration of decellularized vascular implants by side-specific coating with stromal cell-derived factor 1α and fibronectin

Optimized biocompatibility is crucial for the durability of cardiovascular implants. Previously, a combined coating with fibronectin (FN) and stromal cell-derived factor 1α (SDF1α) has been shown to accelerate the in vivo cellularization of synthetic vascular grafts and to reduce the calcification of biological pulmonary root grafts. In this study, we evaluate the effect of side-specific luminal SDF1α coating and adventitial FN coating on the in vivo cellularization and degeneration of decellularized rat aortic implants. Aortic arch vascular donor grafts were detergent-decellularized. The luminal graft surface was coated with SDF1α, while the adventitial surface was coated with FN. SDF1α-coated and uncoated grafts were infrarenally implanted (n = 20) in rats and followed up for up to eight weeks. Cellular intima population was accelerated by luminal SDF1α coating at two weeks (92.4 ± 2.95% versus 61.1 ± 6.51% in controls, p < 0.001). SDF1α coating inhibited neo-intimal hyperplasia, resulting in a significantly decreased intima-to-media ratio after eight weeks (0.62 ± 0.15 versus 1.35 ± 0.26 in controls, p < 0.05). Furthermore, at eight weeks, media calcification was significantly decreased in the SDF1α group as compared to the control group (area of calcification in proximal arch region 1092 ± 517 μm² versus 11 814 ± 1883 μm², p < 0.01). Luminal coating with SDF1α promotes early autologous intima recellularization in vivo and attenuates neo-intima hyperplasia as well as calcification of decellularized vascular grafts.

Examination of Anterior Leaflet Pseudoprolapse Causing Severe Mitral Regurgitation and Its Ideal Surgical Procedure

BACKGROUND

The aim of this study is to evaluate severe mitral regurgitation caused by so called atrial leaflet "pseudoprolapse" and verify the effect of simple annular stabilization.

METHODS

One-hundred-twenty-two patients underwent surgery for severe mitral regurgitation at our institute between January 2015 to July 2018. Of those, 32 cases diagnosed as anterior leaflet prolapse that underwent mitral repair were analyzed. Ten cases with pseudoprolapse, which is defined as anterior leaflet prolapse without dropping into the left atrium beyond the annular line causing eccentric regurgitation flow directed to the posterior atrium, were classified as the Pseudoprolapse Group. The other 22 cases had obvious anterior leaflet prolapse dropping into the left atrium; these cases were classified as the True Prolapse Group. We compared clinical findings between the 2 groups and reviewed pseudoprolapse cases.

RESULTS

Patients in the Pseudoprolapse Group had lower ejection fraction and lower regurgitation volume than those in the True Prolapse Group. A2 lesion as main inflow of regurgitation was more included in the Pseudoprolapse Group. All but one patient in the Pseudoprolapse Group received only simple annuloplasty, and all patients in the True Prolapse Group received leaflet repair and annuloplasty. In both groups, mid-term regurgitation grade and the reoperation rate were satisfactory. In the Pseudoprolapse Group, 6 cases were clarified as atrial functional mitral regurgitation, and 4 cases were considered to have focal posterior leaflet tethering.

CONCLUSIONS

Pseudoprolapse cases could be characterized by low ejection fraction, low regurgitation volume, and A2 prolapse. For most cases with pseudoprolapse, simple annuloplasty may be enough, however further study is needed.

Failed transcatheter pulmonary artery embolization in a patient suffering from massive hemoptysis after thoracic endovascular aortic repair

An emergency thoracic endovascular aortic repair (TEVAR) with zone 2 landing without revascularization of the left subclavian artery was performed due to the impending rupture of a distal arch aneurysm in an old patient presenting hemoptysis. Two months later, the patient had recurrent massive hemoptyses and continued after additional zone 0 TEVAR. The lung parenchyma was considered to be the bleeding source and transcatheter pulmonary artery embolization was performed, and the episodes of massive hemoptysis appeared to have ceased. However, the patient died of sudden recurrent massive hemoptysis 40 days later. Inflammation and/or infection of the lung parenchyma adjunct to the aortic aneurysm could be cause of fatal hemoptysis, and aggressive therapy such as lung resection should be considered in such patients.

Total arch replacement with bilateral extra-anatomical axillary artery bypass and frozen elephant trunk technique for Kommerell's diverticulum

A Kommerell's diverticulum is a rare congenital aortic arch anomaly associated with a high rate of aortic rupture or dissection. Therefore, surgical or endovascular repair should be considered early. A 64-year-old man was incidentally found to have an aortic arch anomaly, Kommerell's diverticulum, with a right aberrant subclavian artery and distal arch aneurysm. Hybrid total arch replacement with bilateral extra-anatomical axillary artery bypass and frozen elephant trunk technique was performed. This particular surgical approach would be a treatment option for any type of Kommerell's diverticulum.

Delayed thoracic wall bleeding after minimally invasive mitral valve repair

The first case of late thoracic wall bleeding after minimally invasive mitral valve repair treated by endovascular therapy is reported. A 55-year-old woman underwent mitral valve repair and tricuspid annuloplasty through a mini-thoracotomy approach. Her postoperative course was uneventful until she had anemia one week after the surgery. Contrast-enhanced computed tomography showed right hemothorax due to bleeding from a branch of the right lateral thoracic artery. Endovascular coil embolization and gelatin sponge injection were performed. The patient was discharged without any complications on postoperative day 20.

Dramatic improvement of left ventricular function after switching the ventricular pacing site from the right ventricular apex to the left ventricular free wall via a left mini thoracotomy: a case report

The case of a patient with pacemaker-induced cardiomyopathy in whom left ventricular (LV) function was dramatically improved after switching the ventricular pacing site from the right ventricular apex to the LV free wall via a left mini thoracotomy due to pacemaker-associated infective endocarditis (PAIE) is presented. Our experience suggests that a surgically implanted epicardial LV lead on the LV lateral wall can be a good alternative pacing site that preserves LV function, especially in patients with PAIE.

A case of pulmonary artery sarcoma that was initially mis-diagnosed as pulmonary embolism

Pulmonary artery sarcoma is a rare and highly malignant neoplasm. Early diagnosis and a multidisciplinary approach including surgical treatment and optimal medical therapy could prolong survival. Since the clinical symptoms and imaging findings of pulmonary artery sarcoma mimic pulmonary embolism, definitive diagnosis and surgical intervention are often delayed. In this report, a case of pulmonary artery sarcoma that was initially misdiagnosed as pulmonary embolism is presented.

Manual repositioning of lung hernia after minimally invasive cardiac surgery

Minimally invasive cardiac surgery has recently become widespread because it has few disadvantages. However, lung hernia has been reported as a rare complication of minimally invasive cardiac surgery (MICS), and normally requiring additional surgical procedures. We describe herein a case of manual repositioning of lung hernia after MICS.

Coronary-Pulmonary Artery Fistula Ligation and Mitral Valve Repair Through a Mini-Thoracotomy Approach

A 39-year-old man with severe mitral regurgitation was referred to our institution for surgical evaluation. During preoperative workup, a coronary-pulmonary artery fistula was incidentally found by computed tomography. After multidisciplinary cardiac team discussion, the decision was made to proceed with coronary-pulmonary artery fistula ligation and mitral valve repair through a mini-thoracotomy approach. Cardiopulmonary bypass was initiated with femoral vessels. A mini-thoracotomy was made in the fourth intercostal space. First, mitral valve repair with posterior leaflet folding and ring annuloplasty was done. The coronary-pulmonary artery fistula was running on the roof of the left atrium and was ligated with metal clips under thoracoscopic vision. Postoperative computed tomography showed no residual fistula.

Open brachiocephalic artery stent for static obstruction caused by acute type A aortic dissection

Brachiocephalic artery dissection complicated by acute type A aortic dissection occasionally causes cerebral malperfusion. Although immediate central aortic repair has been the standard treatment for aortic dissection, dissection in supra-aortic vessels frequently remains after the surgery. The residual brachiocephalic artery dissection is reported to be associated with late neurological events. Therefore, additional intervention for brachiocephalic artery dissection during central aortic repair should be considered in selected cases. In this report, we describe two cases requiring open brachiocephalic artery stenting simultaneous with central aortic repair. There were no neurological or stent induced complications at latest follow-up.

Serum Neuron-Specific Enolase Level as Predictor of Neurologic Outcome after Aortic Surgery

BACKGROUND

This study aimed to evaluate the significance of serum neuron-specific enolase (NSE) level as a predictor of neurologic injury in thoracic aortic surgery.

METHODS

We neurologically assessed 60 consecutive patients who underwent thoracic aortic surgery for thoracic aortic aneurysm (n = 26) and aortic dissection (n = 34). Using moderate hypothermic circulatory arrest with antegrade cerebral perfusion, total arch replacement and hemiarch replacement were performed in 37 and 23 patients, respectively. Serum NSE levels in venous blood samples drawn before surgery and at 1 day after surgery were measured. Severity of neurologic injury was categorized as either uncomplicated (n = 48), temporary neurologic dysfunction (TND, n = 5), or permanent neurologic dysfunction (PND, n = 7). The extent of stroke was estimated on computed tomography or magnetic resonance imaging.

RESULTS

The NSE level significantly differed among the three groups (PND > TND > uncomplicated) on the first postoperative day. Receiver-operating characteristic curve analysis showed that the cutoff value of NSE level was 34.14 ng/mL for neurologic injury (sensitivity, 0.769; specificity, 0.851) and 43.56 ng/mL for PND (sensitivity, 1.000; specificity, 0.963). The NSE level significantly correlated with the extent of stroke (r = 0.61, p < 0.001).

CONCLUSION

Serum NSE level is a significant predictor of adverse neurologic outcomes and extent of stroke after thoracic aortic surgery.

Transfer of a minimally invasive mitral valve repair program from a high-volume center to a very low volume center: how many cases are necessary to maintain acceptable results?

OBJECTIVE

To investigate whether minimally invasive mitral valve repair (MIMVR) can be transferred from a high-volume center into a very small volume center and to clarify how many cases are necessary for maintenance of this program, early outcomes of MIMVR in Asahikawa Medical University were compared with those results in patients operated by a single surgeon in Duesseldorf University Hospital.

METHODS

Sixty-five patients who underwent MIMVR in Asahikawa Medical University (group A) between May 2014 and July 2018 and 134 patients who underwent MIMVR in Duesseldorf University Hospital (group D) between September 2009 and January 2014 by a surgeon who started MIMVS later in Asahikawa were retrospectively analyzed.

RESULTS

In group D, there were more patients with ischemic mitral valve regurgitation and with annular calcification than in group A. Survival rate at 6 months and 1 year was 98.5% and 98.5% in group A and 92.9% and 91.3% in group D, respectively. EuroSCORE II was significantly higher in patients dead within 30 days and within the first year.

CONCLUSIONS

The present study demonstrated that MIMVR programs can be transferred with acceptable early results into very low volume centers, if the team is developed by surgeons who are well trained and experienced in MIMVR. Moreover, the present study suggested that case number for maintenance of acceptable results may be obviously less than the previous recognition that this kind of specialized surgery could be maintained with at least 50 cases annually. However, meticulous preparations for surgery are essential for satisfactory surgical outcomes.

[Tricuspid Valve Aneurysm Preoperatively Diagnosed with Right Atrial Tumor;Report of a Case]

A 79-year-old woman visited a hospital with coronary vasospastic angina and supraventricular tachycardia. Periodic inspection of echocardiography suggested a right atrial tumor which was not pointed out 6 months ago, but magnetic resonance imaging suggested a valve aneurysm. These findings were contradictory. We preoperatively diagnosed a cardiac tumor because of its new onset and mobility. Tumor resection and valve repair was planned in consideration of the risk of embolism. As a result, we finally diagnosed tricuspid valve aneurysm from the intraoperative findings and histopathological findings. We assumed that valve aneurysm was formed in the healing process of subclinical infective endocarditis. It was inferred that preoperative diagnosis of valve aneurysm is very difficult.

A left ventricular assist device for a patient with peripartum cardiomyopathy

Since its introduction in Japan in 1980, the extracorporeal left ventricular assist device has been used as a bridge to the recovery of cardiac function or to heart transplantation by many institutions. In this case report, we describe a 23-year-old female with peripartum cardiomyopathy. She had a persistently low cardiac index despite intensive care with intravenous inotropes, intra-aortic balloon pumping and extracorporeal membrane oxygenation; thus, we implanted an extracorporeal left ventricular assist device. Thereafter, her cardiac function gradually improved; the device was removed 2 months after the implantation. She currently has good heart function.

Tranexamic acid blocks the thrombin-mediated delay of epidermal permeability barrier recovery induced by the cedar pollen allergen, Cry j1

We previously demonstrated that Cry j1, the major pollen allergen of Cryptomeria japonica (Japanese cedar), transiently increases protease activity and intracellular Ca²⁺ concentration in cultured human keratinocytes, and delays recovery after stratum corneum barrier disruption in human skin ex vivo. Topical application of tranexamic acid or trypsin-type serine protease inhibitors accelerates barrier recovery. We hypothesized that tranexamic acid might prevent the transient protease activity increase and the barrier recovery delay induced by Cry j1. Here, we tested this hypothesis and examined the mechanism involved. In cultured human keratinocytes, knock-down of protease-activated receptor 1 (PAR-1) reduced the transient increase of calcium induced by Cry j1, whereas knock-down of PAR-2 did not. Knock-down of thrombin significantly reduced the transient increases of calcium concentration and protease activity. Tranexamic acid, soybean trypsin inhibitor, or bivalirudin (a thrombin inhibitor) also reduced the calcium elevation induced by Cry j1 and/or thrombin. Co-application of tranexamic acid or bivalirudin with Cry j1 to human skin ex vivo blocked the delay of barrier recovery. These results suggest that thrombin and PAR-1 or PAR-1-like receptor might mediate the adverse effects of Cry j1 on human epidermal keratinocytes, and could open up a new strategy for treating inflammatory skin diseases.

Total arch replacement as treatment for repeated cerebral infarctions due to unstable plaque simultaneously in the innominate artery and left subclavian artery: a case report

We report a case of total arch replacement in a patient who suffered repeated cerebral infarctions due to unstable plaque simultaneously in the innominate and left subclavian arteries.

Observations of cavity polaritons in one-dimensional photonic crystals containing a liquid-crystalline semiconductor based on perylene bisimide units

We investigated the optical transmission properties of one-dimensional photonic crystal (1D-PC) microcavity structures containing the liquid-crystalline (LC) perylene tetracarboxylic bisimide (PTCBI) derivative. We fabricated the microcavity structures for this study by two different methods and observed the cavity polaritons successfully in both samples. For one sample, since the PTCBI molecules were aligned in the cavity layer of the 1D-PC by utilizing a friction transfer method, vacuum Rabi splitting energy was strongly dependent on the polarization of the incident light produced by the peculiar optical features of the LC organic semiconductor. For the other sample, we did not utilize the friction transfer method and did not observe such polarization dependence. However, we did observe a relatively large Rabi splitting energy of 187 meV, probably due to the improvement of optical confinement effect.

Giant left atrial myxoma causing acute ischemic stroke in a child

Ischemic stroke is uncommon in pediatric populations and is sometimes caused by cardiac myxoma. In such cases, neurological deficits initially present in ischemic stroke due to emboli or thrombi of the myxoma. Echocardiography is helpful to diagnose myxoma in a timely manner and allows urgent surgical resection of the myxoma. We report a successful case of myxoma in a 7-year-old boy who initially presented with left-sided hemiparesis.

Safety assessment of the Clostridium butyricum MIYAIRI 588® probiotic strain including evaluation of antimicrobial sensitivity and presence of Clostridium toxin genes in vitro and teratogenicity in vivo

Probiotics are live microorganisms ingested for the purpose of conferring a health benefit on the host. Development of new probiotics includes the need for safety evaluations that should consider factors such as pathogenicity, infectivity, virulence factors, toxicity, and metabolic activity. Clostridium butyricum MIYAIRI 588® (CBM 588®), an anaerobic spore-forming bacterium, has been developed as a probiotic for use by humans and food animals. Safety studies of this probiotic strain have been conducted and include assessment of antimicrobial sensitivity, documentation of the lack of Clostridium toxin genes, and evaluation of CBM 588® on reproductive and developmental toxicity in a rodent model. With the exception of aminoglycosides, to which anaerobes are intrinsically resistant, CBM 588® showed sensitivity to all antibiotic classes important in human and animal therapeutics. In addition, analysis of the CBM 588® genome established the absence of genes for encoding for α, β, or ε toxins and botulin neurotoxins types A, B, E, or F. There were no deleterious reproductive and developmental effects observed in mice associated with the administration of CBM 588®. These data provide further support for the safety of CBM 588® for use as a probiotic in animals and humans.

Formation mechanism of plasmonic silver nanohexagonal particles made by galvanic displacement reaction

Multi-element XPS depth profile analysis made clear that Ag nanoscale hexagonal columns formed by newly-discovered galvanic displacement reaction are covered with Cu compounds which prevent Ag columns from fusion, resulting in stable hotspots.

Comparison of antibiotic susceptibility in viridans group streptococci in low and high antibiotic-prescribing General Practices

WHAT IS KNOWN AND OBJECTIVE

Antibiotic resistance has become a global public health issue. Most antibiotics are prescribed in the community, although there is less stewardship of such agents in the community compared to secondary and tertiary care. Few studies have attempted to examine the prescribing practices in General Practice and its impact on antibiotic resistance and, therefore, a study was performed in order to compare antibiotic susceptibilities of commensal viridans group streptococci (VGS) obtained from patient cohorts in General Practices (GP), who were high and low prescribers of oral antibiotics.

METHOD

Sixty-five patients (<1 month-81 years; 77% female: 23% male) were enrolled onto the study, and viridans group streptococci (n = 5/patient) were collected from each patient's nasal passages and oropharynx region and tested for antibiotic susceptibility against (i) tetracyclines (doxycycline); (ii) macrolides (erythromycin); (iii) β-lactams (penicillin G); and (iv) fluoroquinolones (ofloxacin & levofloxacin).

RESULTS AND DISCUSSION

There were no significant differences in MICs between high and low GP prescribers with doxycycline (P = 0·094), erythromycin (P = 0·122), ofloxacin (P = 0·193) and levofloxacin (P = 0·058). However, there was a significant difference between high and low GP practices with regard to penicillin G (P = 0·031). This finding is important as the β-lactams are the most commonly prescribed oral antibiotic in the community.

WHAT IS NEW AND CONCLUSION

This study demonstrates that high prescribing practices may lead to an altered (higher) level of resistance to these agents in the commensal VGS population, which may be important as reservoirs of antibiotic resistance determinants in subsequent horizontal gene transfer events, particularly with newly colonizing pathogens, including pneumococci. Primary care physicians should be aware that increased prescribing of antibiotics may led to increased level of penicillin resistance.

Distinct dopaminergic control of the direct and indirect pathways in reward-based and avoidance learning behaviors

The nucleus accumbens (NAc) plays a pivotal role in reward and aversive learning and learning flexibility. Outputs of the NAc are transmitted through two parallel routes termed the direct and indirect pathways and controlled by the dopamine (DA) neurotransmitter. To explore how reward-based and avoidance learning is controlled in the NAc of the mouse, we developed the reversible neurotransmission-blocking (RNB) technique, in which transmission of each pathway could be selectively and reversibly blocked by the pathway-specific expression of transmission-blocking tetanus toxin and the asymmetric RNB technique, in which one side of the NAc was blocked by the RNB technique and the other intact side was pharmacologically manipulated by a transmitter agonist or antagonist. Our studies demonstrated that the activation of D1 receptors in the direct pathway and the inactivation of D2 receptors in the indirect pathway are key determinants that distinctly control reward-based and avoidance learning, respectively. The D2 receptor inactivation is also critical for flexibility of reward learning. Furthermore, reward and aversive learning is regulated by a set of common downstream receptors and signaling cascades, all of which are involved in the induction of long-term potentiation at cortico-accumbens synapses of the two pathways. In this article, we review our studies that specify the regulatory mechanisms of each pathway in learning behavior and propose a mechanistic model to explain how dynamic DA modulation promotes selection of actions that achieve reward-seeking outcomes and avoid aversive ones. The biological significance of the network organization consisting of two parallel transmission pathways is also discussed from the point of effective and prompt selection of neural outcomes in the neural network.

Single-shot detection of mid-infrared spectra by chirped-pulse upconversion with four-wave difference frequency generation in gases

Single-shot detection of ultrabroadband mid-infrared spectra was demonstrated by using chirped-pulse upconversion technique with four-wave difference frequency generation in gases. Thanks to the low dispersion of the gas media, the bandwidth of the phase matching condition of the upconversion process becomes very broad and the entire mid-infrared spectrum spanning from 200 to 5500 cm(-1) was upconverted by using a 10 ps chirped pulse to visible wavelength radiation, which was detected with a conventional visible dispersive spectrometer. This method was demonstrated by the successful measurement of infrared absorption spectra of organic polymer films.

Construction, expression and characterisation of recombinant molecules of the urease gene operon from a urease-positive thermophilic Campylobacter (UPTC) isolate

A recombinant molecule of the full-length urease gene operon was constructed in vitro from the Japanese urease-positive thermophilic Campylobacter (UPTC) CF89-12 isolate and expressed in Escherichia coli cells. Several large deletion recombinant variants of urease subunit genes were also constructed and expressed in E. coli cells. A positive urease reaction with the log-phase cultured E. coli JM109 cells in the NiCl2-containing medium transformed with pGEM-T vector carrying the recombinant molecule of the full-length operon was detected with isopropyl-beta-D-thiogalactoside. Among the several deletion recombinant variants, each ureA-, ureB-, ureE-, ureF-, ureG- and ureH-large deficient, only ureE-large deletion variant (63% deficient) showed a positive urease reaction (approximately 15-fold). In addition, a ureE-complete deletion recombinant variant (100% deficient) constructed also showed a positive reaction of urease (approximately 18-fold). Recombinant urease subunits A and B were immunologically identified by Western blot analysis with anti-urease alpha (A) and beta (B) raised against Helicobacter pylori.

Influence of Adrenal Subclinical Hypercortisolism on Hypertension in Patients with Adrenal Incidentaloma

The purpose of our study was to clarify whether subtle cortisol-producing tumors, such as not only subclinical Cushing’s syndrome (SubCS) but also subclinical hypercortisolism (SH), influence the prevalence of hypertension, since numerous basic research studies have noted that glucocorticoid excess influences blood pressure.

80 patients with adrenocortical adenomas (39 women and 41 men; mean age 62.1 years) were enrolled. SubCS was diagnosed using a diagnostic criteria, and SH was diagnosed as the presence of a serum cortisol level greater than 50 nmol/L following 1-mg dexamethasone suppression test (DST).

SubCS, SH, or non-functioning adrenocortical adenoma (NF) was diagnosed in 14, 13, or 53 patients, respectively. The prevalence of hypertension differed significantly among the diagnoses (SubCS, 78.6%; SH, 84.6%; NF, 39.6%; P=0.002), whereas no differences in other clinical characteristics such as age, sex, or waist girth were observed. The patients with SH had an 11.7-fold increased risk (95% confidence interval: 1.9–72.7, P=0.009) and those with SubCS had a 9.5-fold increased risk (95% confidence interval: 1.9–48.3, P=0.007) for hypertension compared to those with NF using a multivariate analysis.

We demonstrated that subtle cortisol-producing tumors, such as SH as well as SubCS, were an independent risk factor for hypertension. The cut-off value of the 1-mg DST would be appropriate to predict the development of hypertension.

Two cases of endovascular abdominal aortic aneurysm repair with iliac aneurysm using a zenith iliac bifurcation graft

We report on treatment of an abdominal aortic aneurysm with common iliac artery aneurysm using an iliac branch device. We performed 2 cases because of a large common iliac artery aneurysm or a complication of an internal iliac artery aneurysm. Both cases had a good postoperative course and progressed without embolizing the iliac branch device during follow-up period. Though there is a drawback, it is not covered by the national insurance program in Japan and cannot be used in all applicable cases. However, use of a unilateral or bilateral iliac branch device allows us to maintain the bloodstream of the internal iliac artery, thus suggesting it to be effective in such cases.

Low serum levels of total and high-molecular-weight adiponectin predict the development of metabolic syndrome in Japanese-Americans

BACKGROUND

Adiponectin is thought to play a significant role in the development of both insulin resistance and metabolic syndrome. Yet, there is very few evidence about the association plasma adiponectin and metabolic syndrome in the prospective study. Adiponectin exists as multimers in serum, and high-molecular-weight (HMW) adiponectin is particularly considered to be the active form of the protein.

AIM

We investigated whether serum HMW adiponectin as well as total adiponectin is associated with the development of metabolic syndrome in a longitudinal study.

SUBJECTS AND METHODS

We enrolled 224 men and 312 women of Japanese- Americans without metabolic syndrome at baseline who were followed for an average of 3.2 yr. The association of plasma total and HMW adiponectin with a progression to metabolic syndrome was examined.

RESULTS

Subjects who developed metabolic syndrome had significantly lower plasma total and HMW adiponectin levels at baseline than those who did not develop metabolic syndrome. In a Cox proportional hazards model, lower total and HMW adiponectin levels were independent risk factors for the development of metabolic syndrome after adjusting for age, body mass index, classification of 75-g glucose tolerance test, and homeostasis model assessment (hazards ratio: total, 0.684, p=0.017, in men; 0.606, p=0.003, in women; HMW, 0.687, p=0.014, in men; 0.704, p=0.029, in women, respectively).

CONCLUSIONS

Low circulating levels of total and HMW adiponectin may be a possible predictor for the development of metabolic syndrome.

Molecular and comparative analyses of the full-length cytolethal distending toxin (cdt) gene operon and its adjacent genetic loci from urease-positive thermophilic Campylobacter (UPTC) organisms

Molecular and comparative analyses of the full-length cytolethal distending toxin (cdt) gene operon and its adjacent genetic loci (2.7-9.4 kilo base pairs in length) are carried out with 12 urease-positive thermophilic Campylobacter (UPTC) isolates using several polymerase chain reaction (PCR) primer pairs. Three putative open reading frames (ORFs) for cdtA, cdtB and cdtC, two putative promoters and a hypothetically intrinsic rho-independent transcription terminator were identified in all the operons of the 12 UPTC isolates examined. Although the number of amino acid residues slightly varied for the putative cdtA and cdtC ORFs, those for the cdtB were similar among all the UPTC isolates, as well as the six urease-negative (UN) C. lari examined previously. Regarding the cdt genes in UPTC CF89-12, each ORF commenced with an ATG start codon and terminated with a TAG stop codon for cdtA and cdtB and a TAA for cdtC. Start and stop codons of the three ORFs for the other 11 UPTC isolates were identical to those from the UPTC CF89-12 isolate except for the TTG start codon for cdtC in the two isolates (NCTC12892 and 12893) and the TGA stop codon for cdtA in five isolates (A1, A2, A3, 89049 and 92251). Two putative promoter structures, consisting of sequences at the -35-like (TTAATA) and -10-like (TATTAA) regions, as well as the start codon (ATG), were identified for the transcriptional promoter, immediately upstream of the cdtA gene in all the 12 isolates, Although the genetic heterogeneity of the cdtB gene locus occurred in all 28 C. lari isolates (n = 16 UN C. lari; n = 12 UPTC) examined, all nine amino acid-specific DNase residues were completely conserved in all their cdtB genes. Variable gene insertions with heterogeneous order and combinations occurred between cdtC and lpxB genes in the all UPTC organisms examined.

Hepatitis C virus-related kidney disease: various histological patterns

BACKGROUND

Although hepatitis C virus (HCV) infection is known to be associated with Type 2 cryoglobulinemic glomerulopathy (CG), only a few reports about other types of nephropathy have been published.

METHODS

68 HCV antibody positive patients in whom renal biopsy had been performed for persistent proteinuria, hematuria, and/or renal dysfunction between 1992 and 2008 at our institute were included. The histological, clinical and laboratory characteristics including the age, gender, hypertension, diabetes mellitus, liver histology (chronic hepatitis or liver cirrhosis), HCV-RNA, HCV genotype, splenomegaly, gastroesophageal varices, serum creatinine, hemoglobin, platelet count, rheumatoid factor, cryoglobulin, IgG, IgA, IgM, CH50, C3, C4, creatinine clearance, 24-h protein excretion, and hematuria, between their nephropathy with and without immune deposition were compared.

RESULTS

Nephropathy was classified into two groups based on the detection of immune deposits by immunofluorescence microscopy: i.e., a positive group (n = 39) and a negative group (n = 29). The former group was further classified into three types of nephropathy: IgG dominant group (n = 10) (including membranous nephropathy (MN)), IgA dominant group (n = 20) (including IgA nephropathy (IgAN)), membranoproliferative glomerulonephritis (MPGN) (IgA type)), and IgM dominant group (n = 9) (MPGN apart from the IgA type). The latter group included diabetic nephropathy (n = 13), focal glomerular sclerosis (n = 4), and benign nephrosclerosis (n = 3), malignant nephrosclerosis (n = 1), tubulointerstitial nephritis (TIN) (n = 2), minimal change nephrotic syndrome (n = 1), cast nephropathy (n = 1), granulomatous TIN (n = 1), and others (n = 3). An increased serum IgM level, hypocomplementemia, splenomegaly, thrombocytopenia, liver cirrhosis, hematuria, and a high HCV RNA level were features of patients with MPGN of IgM dominant group (consistent with "CG").

CONCLUSIONS

Our results showed various histological patterns of HCV-related kidney disease and the specificity of CG, and revealed that a minority of HCV patients (n = 7) presented typical CG, while IgAN, MN, and diabetic nephropathy were more frequent.