Usefulness of an artificial neural network for a beginner to achieve similar interpretations to an expert when examining myocardial perfusion images.

This study examined whether using an artificial neural network (ANN) helps beginners in diagnostic cardiac imaging to achieve similar results to experts when interpreting stress myocardial perfusion imaging (MPI). One hundred and thirty-eight patients underwent stress MPI with Tc-labeled agents. An expert and a beginner interpreted stress/rest MPI with or without the ANN and the results were compared. The myocardium was divided into 5 regions (the apex; septum; anterior; lateral, and inferior regions), and the defect score of myocardial blood flow was evaluated from 0 to 4, and SSS, SRS, and SDS were calculated. The ANN effect, defined as the difference in each of these scores between with and without the ANN, was calculated to investigate the influence of ANN on the interpreters' performance. We classified 2 groups (insignificant perfusion group and significant perfusion group) and compared them. In the same way, classified 2 groups (insignificant ischemia group and significant ischemia group) and compared them. Besides, we classified 2 groups (normal vessels group and multi-vessels group) and compared them. The ANN effect was smaller for the expert than for the beginner. Besides, the ANN effect for insignificant perfusion group, insignificant ischemia group and multi-vessels group were smaller for the expert than for the beginner. On the other hand, the ANN effect for significant perfusion group, significant ischemia group and normal vessels group were no significant. When interpreting MPI, beginners may achieve similar results to experts by using an ANN. Thus, interpreting MPI with ANN may be useful for beginners. Furthermore, when beginners interpret insignificant perfusion group, insignificant ischemia group and multi-vessel group, beginners may achieve similar results to experts by using an ANN.

TDP-43 pathology in multiple system atrophy: colocalization of TDP-43 and α-synuclein in glial cytoplasmic inclusions.

AIMS: This study aimed to assess clinicopathologic features of transactive response DNA-binding protein of 43 kDa (TDP-43) pathology and its risk factors in multiple system atrophy (MSA). METHODS: Paraffin-embedded sections of the amygdala and basal forebrain from 186 autopsy-confirmed MSA cases were screened with immunohistochemistry for phospho-TDP-43. In cases having TDP-43 pathology, additional brain regions were assessed. Immunohistochemical and immunofluorescence double-staining and immunogold electron microscopy (IEM) were performed to evaluate colocalization of TDP-43 and α-synuclein. Genetic risk factors for TDP-43 pathology were also analysed. RESULTS: Immunohistochemistry showed various morphologies of TDP-43 pathology in 13 cases (7%), such as subpial astrocytic inclusions, neuronal inclusions, dystrophic neurites, perivascular inclusions and glial cytoplasmic inclusions (GCIs). Multivariable logistic regression models revealed that only advanced age, but not concurrent Alzheimer's disease, argyrophilic grain disease or hippocampal sclerosis, was an independent risk factor for TDP-43 pathology in MSA (OR: 1.11, 95% CI: 1.04-1.19, P = 0.002). TDP-43 pathology was restricted to the amygdala in eight cases and extended to the hippocampus in two cases. The remaining three cases had widespread TDP-43 pathology. Immunohistochemical and immunofluorescence double-staining and IEM revealed colocalization of α-synuclein and TDP-43 in GCIs with granule-coated filaments. Pilot genetic studies failed to show associations between risk variants of TMEM106B or GRN and TDP-43 pathology. CONCLUSIONS: TDP-43 pathology is rare in MSA and occurs mainly in the medial temporal lobe. Advanced age is a risk factor for TDP-43 pathology in MSA. Colocalization of TDP-43 and α-synuclein in GCIs suggests possible direct interaction between the two molecules.

Influence of exercise training with thigh compression on heat-loss responses.

We investigated the effect of thigh compression, which accelerates activation of central command and muscle metabo- and mechanoreceptors, on the adaptation of sweating and cutaneous vascular responses during exercise heat acclimation. Nine non-heat-acclimated male subjects were acclimated to heat (32 °C and 50% RH) while cycling [50% of maximum oxygen uptake ( V ˙ O 2 m a x )] 60 min/day for 7 days (control group). The experimental group (n = 9) conducted the same training while the proximal thighs were compressed by a cuff at 60 mmHg. V ˙ O 2 m a x , acetylcholine-induced forearm sweating rate (iontophoresis), and mean sweating and cutaneous vascular responses on the forehead, chest, and forearm (SRmean and CVCmean ) during passive heating were evaluated before and after training. Training significantly increased V ˙ O 2 m a x while did not affect acetylcholine-induced sweating rates in either group. Training significantly decreased Tb thresholds for SRmean and CVCmean during passive heating without the alternations of sensitivities in both groups. Although SRmean during passive heating at a given ΔTb was not improved in either group, CVCmean was significantly (P < 0.05) attenuated after exercise training only in experimental group. Our results indicate that thigh cuff compression during exercise heat acclimation does not influence adaptation of the sweating response but attenuate cutaneous vasodilation.

Identification and characterization of novel multiple bacteriocins produced by Lactobacillus sakei D98.

AIM: To characterize novel multiple bacteriocins produced by Lactobacillus sakei D98. METHODS AND RESULTS: Lactobacillus sakei D98 isolated from Shubo (rice malt) produced at least three bacteriocins. Using three purification steps, three novel antimicrobial peptides termed sakacin D98a, sakacin D98b and sakacin D98c were purified from the culture supernatant. Amino acid and DNA sequencing analysis revealed that the sakacins D98a, D98b and D98c are novel class IIa-like or class IId bacteriocins. In particular, sakacin D98b has a variant pediocin-box sequence, YANGVXC (with Ala instead of Gly), and a different location for the disulfide bridge (Cys(11) and Cys(18)) from that found in other class IIa bacteriocins. CONCLUSIONS: Three novel bacteriocins were identified from Lactobacillus sakei D98. Their antimicrobial spectra and intensities indicate that these sakacins would have different modes of action. In addition, sakacin D98b showed low inhibitory activity against Listeria, probably due to the differences in amino acids and position of the disulfide bridge compared with the other class IIa bacteriocins. SIGNIFICANCE AND IMPACT OF STUDY: Sakacins D98a and D98c are novel bacteriocins belonging to class IId bacteriocins. On the other hand, sakacin D98b, a class IIa-like bacteriocin, has a unique internal structure and activity spectrum.

Increasing temperature speeds intracellular PO2 kinetics during contractions in single Xenopus skeletal muscle fibers.

Precise determination of the effect of muscle temperature (T(m)) on mitochondrial oxygen consumption kinetics has proven difficult in humans, in part due to the complexities in controlling for T(m)-related variations in blood flow, fiber recruitment, muscle metabolism, and contractile properties. To address this issue, intracellular Po(2) (P(i)(O(2))) was measured continuously by phosphorescence quenching following the onset of contractions in single Xenopus myofibers (n = 24) while controlling extracellular temperature. Fibers were subjected to two identical contraction bouts, in random order, at 15°C (cold, C) and 20°C (normal, N; n = 12), or at N and 25°C (hot, H; n = 12). Contractile properties were determined for every contraction. The time delay of the P(i)(O(2)) response was significantly greater in C (59 ± 35 s) compared with N (35 ± 26 s, P = 0.01) and H (27 ± 14 s, P = 0.01). The time constant for the decline in P(i)(O(2)) was significantly greater in C (89 ± 34 s) compared with N (52 ± 15 s; P < 0.01) and H (37 ± 10 s; P < 0.01). There was a linear relationship between the rate constant for P(i)(O(2)) kinetics and T(m) (r = 0.322, P = 0.03). Estimated ATP turnover was significantly greater in H than in C (P < 0.01), but this increased energy requirement alone with increased T(m) could not account for the differences observed in P(i)(O(2)) kinetics among conditions. These results demonstrate that P(i)(O(2)) kinetics in single contracting myofibers are dependent on T(m), likely caused by temperature-induced differences in metabolic demand and by temperature-dependent processes underlying mitochondrial activation at the start of muscle contractions.

Acute effect of oral water intake during exercise on post-exercise hypotension.

BACKGROUND/OBJECTIVES: Post-exercise hypotension (PEH) is a sustained reduction in mean arterial blood pressure (MAP) after prolonged exercise. As water drinking is known to elicit a large acute pressor response, we aimed to explore the effect of drinking water during exercise on PEH. SUBJECTS/METHODS: Ten normotensive male volunteers performed the control protocol: 30 min supine rest, 60 min cycling exercise in moderate intensity, and 60 min supine rest recovery. In the water drinking protocol, the same procedure was followed but with water intake during exercise to compensate for exercise-induced body weight lost. Heart rate, MAP, cardiac output and blood flow in the brachial artery were measured pre- and post-exercise. The total vascular conductance (TVC) and the vascular conductance (VC) in the brachial artery were calculated pre- and post-exercise, and the relative change in plasma volume (ΔPV) was also measured. RESULTS: Body weight loss during exercise was 0.65 ± 0.24 kg in the control. ΔPV was not different during recovery in either protocol. MAP in the control was significantly reduced during the latter half of the recovery compared with baseline. In contrast, MAP in the water drinking showed no reduction during recovery, and was significantly higher than in the control. TVC and VC in the brachial artery were lower in the water drinking, in which vasoconstriction was relatively exaggerated. CONCLUSIONS: Prevention of dehydration after exercise by oral water intake, or oral water intake per se has a role in maintaining post-exercise MAP and it may be related to reduction in TVC.

Minimally invasive removal of a recurrent lumbar herniated nucleus pulposus by the small incised microendoscopic discectomy interlaminar approach.

In this report, we introduce two cases of recurrent herniated nucleus pulposus (HNP) at L5-S1 that were successfully removed using the small incised microendoscopic discectomy (sMED) technique, proposed by Dezawa and Sairyo in 2011. sMED was performed via the interlaminar approach with a percutaneous endoscope. The patients had previously underdone microendoscopic discectomy for HNP. For the recurrent HNP, the sMED interlaminar approach was selected because the HNP occurred at the level of L5-S1; the percutaneous endoscopic transforaminal approach was not possible for anatomical reasons. To perform sMED via the interlaminar approach, we employed new, specially made devices to enable us to use this technique. In conclusion, sMED is the most minimally invasive approach available for HNP, and its limitations have been gradually eliminated with the introduction specially made devices. In the near future, percutaneous endoscopic surgery could be the gold standard for minimally invasive disc surgery.

Analysis of H atoms in a negative ion source plasma with the non-equilibrium electron energy distribution function.

In negative ion sources for the neutral beam injection, it is important to calculate H atom flux onto the plasma grid (PG) surface for the evaluation of H(-) production on the PG surface. We have developed a neutral (H(2) molecules and H atoms) transport code. In the present study, the neutral transport code is applied to the analysis of the H(2) and H transport in a NIFS-R&D ion source in order to calculate the flux onto the PG surface. Taking into account non-equilibrium feature of the electron energy distribution function (EEDF), i.e., the fast electron component, we have done the neutral transport simulation. The results suggest that the precise evaluation of the EEDF, especially in the energy range 15 eV < E < 30 eV is important for the dissociation rate of H(2) molecules by the electron impact collision and the resultant H atom flux on the PG.

Effect of non-uniform electron energy distribution function on plasma production in large arc driven negative ion source.

Spatially non-uniform electron energy distribution function (EEDF) in an arc driven negative ion source (JAEA 10A negative ion source: 10 A NIS) is calculated numerically by a three-dimensional Monte Carlo kinetic model for electrons to understand spatial distribution of plasma production (such as atomic and ionic hydrogen (H(0)∕H(+)) production) in source chamber. The local EEDFs were directly calculated from electron orbits including electromagnetic effects and elastic∕inelastic collision forces. From the EEDF, spatial distributions of H(0)∕H(+) production rate were obtained. The results suggest that spatial non-uniformity of H(0)∕H(+) productions is enhanced by high energy component of EEDF.

Endoscopic removal of herniated nucleus pulposus migrated dorsally to the dural sac.

A herniated nucleus pulposus (HNP) migrated dorsally to the dural sac is a rare condition. Here, we present a case, in which the HNP was removed with minimally invasive spinal endoscopy. A 54-year-old man presented complaining of left leg pain and paresis. Neurologic findings and an MRI suggested an epidural tumor or a dorsally migrated HNP compressing the S1 nerve root and dural sac. With a spinal endoscope, careful laminotomy of caudal L5 and cranial S1 was made. En bloc flavectomy exposed a mass covered with a thin capsule. The mass was identified as a dorsally migrated HNP. After complete HNP fragment removal, the dural sac and S1 nerve root were decompressed. Immediately postoperative, the leg pain subsided and motor function normalized, although the patient complained of numbness at the S1 dermatome area. In summary, a large HNP that had migrated dorsally to the dural sac was successfully removed endoscopically.

[Significance of preoperative ultrasound evaluation of the forearm arteries prior to coronary artery bypass grafting].

We report the significance of preoperative ultrasound evaluation of the forearm arteries in coronary artery bypass grafting (CABG). Ultrasound evaluation was performed in 288 arms with negative Allen's test between August 2004 and July 2007. The diameter, the level of atherosclerotic changes and calcifications, and systolic velocities were evaluated in radial artery (RA) and ulnar artery (UA). The diameter of RA was 2.6 +/- 0.5 mm, and in 30 arms it was smaller than 2 mm. There were 2 occlusions, 4 stenoses, and 20 arteriosclerotic changes in RA. There were 1 occlusion, 8 stenoses, and 4 arteriosclerotic changes in UA. Since there were some overlaps in small diameter and poor qualities of RA and UA, 55 arms (19%) were considered not to qualify as candidates for RA harvest. Pre-operative ultrasound evaluation of the forearm arteries allows safer radial artery harvest and should be performed even in patients with negative Allen' s test.

Significance of Tei-index alterations induced by acute preload reduction with hemodialysis.

AIM: The load dependence of Tei-index, an index to estimate combined systolic and diastolic ventricular functions, remains controversial. Moreover, its significance in the setting of acute preload reduction including hemodialysis (HD) remains unknown. Therefore, we examined the significance of the Tei-index in HD patients. PATIENTS AND METHODS: Doppler echocardiographic parameters of 42 patients with normal left ventricular ejection fraction (LVEF) were evaluated before and after HD. Based on the index of body water excess calculated using a Crit-Line monitor, the patients were assigned to Group A (normal hydration approximately overhydration) and Group B (risk of pulmonary congestion). RESULTS: Group A was younger and had a shorter isovolumic relaxation time (IRT) than Group B before HD. Hemodialysis significantly increased the Tei-index of Group A, which was derived from prolonging IRT and isovolumic contraction time and shortening the ejection time without changing LVEF. Changes in the Tei-index (DeltaTei-index) significantly correlated with the rate at which blood volume decreased. They were derived from graphs generated using the Crit-Line monitor. Furthermore, the DeltaTei-index inversely correlated with the Tei-index before HD. CONCLUSION: These findings suggest that the Tei-index is preload-dependent, which is related to changes in volume and speed. Thus, the Tei-index should be cautiously interpreted according to various hemodynamic situations. However, the correlation between the DeltaTei-index and the Tei-index before HD implies that the latter could be a good indicator of effective fluid removal by HD.

[Minimally invasive technique for harvesting a saphenous vein via one small incision].

We report a minimally invasive technique for harvesting a saphenous vein graft (SVG) via 1 small skin incision. The expected advantages of this technique are better cosmetic results and fewer wound complications than the conventional open technique or the bridging technique. The SVG, 10-15 cm in length, can be harvested by about 3 cm-long single small skin incision. SaphLITE Retractor System (Genzyme Srugical Products, Cambridge), SLS Hematostatic Clip System (Vitalitec International, Plymouth), and curved scissors were necessary instruments for this technique. It is feasible for cases that require a shorter length of SVG.

Development of a voxel phantom of Japanese adult male in upright posture.

A Japanese voxel phantom in upright posture, JM2, has been developed on the basis of CT images of a healthy Japanese adult male. Body characteristics of JM2 were compared with those of the supine voxel phantom, JM, previously developed using CT images of the same person. Differences were found in the shapes of the spine and lower abdomen and the locations of several organs such as kidneys, liver and stomach between the two phantoms. Specific absorbed fractions (SAFs) for 24 target and 11 sources organs were calculated for monoenergetic photon ranging from 0.01 to 4 MeV. It was found that the SAFs for the kidneys as source organ and the lower large intestine wall as target organ in JM2 were significantly higher than those in JM for all photon energies. The differences of the SAFs between the two phantoms were attributed to the differences in the organ distance and organ geometry depending on the posture.

Japanese adult male voxel phantom constructed on the basis of CT images.

A Japanese adult male voxel (volume pixel) phantom (hereinafter referred to as the JM phantom) was constructed on the basis of CT images of a healthy Japanese adult male volunteer. Body characteristics of the JM phantom were compared with those of a voxelised MIRD5 type phantom and a Japanese adult male voxel phantom which was previously developed. The voxel size of the JM phantom is 0.98 x 0.98 x 1 mm(3). The shapes of the organs of the JM phantom, even for small or complicated organs, such as thyroid and stomach, are more realistically reproduced as compared with the previous Japanese voxel phantom (voxel size: 0.98 x 0.98 x 10 mm(3)). Photon self-absorbed fractions (self-AFs) for brain, kidneys, spleen, pancreas, thyroid and urinary bladder wall of JM were evaluated and were compared with those of the other phantoms. In consequence, it was suggested that the mass, shape and thickness of organs are important factors for the determination of self-AFs.

Effect of skin temperature on the ion reabsorption capacity of sweat glands during exercise in humans.

The effect of skin temperature on the ion reabsorption capacity of sweat glands during exercise in humans is unknown. In this study, eight healthy subjects performed a 60-min cycling exercise at a constant intensity (60% VO(2max)) under moderate (25 degrees C) and cool (15 degrees C) ambient temperatures at a constant relative humidity of 40%. The sweating rate (SR), index of sweat ion concentration (ISIC) by using sweat conductivity, esophageal temperature (Tes), mean skin temperature, and heart rate (HR) were measured continuously under both ambient temperatures. The SR and ISIC were significantly lower at the cool ambient temperature versus the moderate temperature. There were no significant differences in the changes in HR and esophageal temperature between these ambient temperature conditions, while the mean skin temperature was significantly lower at the cool ambient temperature by almost 3 degrees C (P < 0.05). The slopes of the relationships between Tes and the SR and ISIC were significantly lower and the thresholds of these relationships were significantly higher at the cool ambient temperature (P < 0.05). The ion reabsorption capacity of the sweat glands was significantly lower (P < 0.05) in a cool environment (0.21 +/- 0.04 vs. 0.52 +/- 0.06 mg/cm(2)/min at 15 and 25 degrees C, respectively) as evaluated using the relationships for SR and ISIC. The results suggest that the ion reabsorption capacity of the sweat glands is influenced by skin temperature during exercise in humans.

Kidney transplantation from non-heart-beating donors: analysis of organ procurement and outcome.

INTRODUCTION: Most donors in Japan have been non-heart-beating donors (NHBD), so-called "marginal donors." In Western countries kidney transplants from NHBD have also been increasing. We analyzed 120 kidneys harvested from NHBD with regard to organ procurement, renal function, graft survival, and the donor factors that affected graft survival. METHODS: Donors were moved into the operating room after cardiac arrest. A double-balloon catheter was inserted into the abdominal aorta via laparotomy. In situ cooling by Euro-Collins solution was started at 500 mL/min. We did not performed cannulation into the femoral artery or vein prior to cardiac arrest. RESULTS: Warm ischemia time (WIT) was 18.6 minutes. Among 108 kidneys (90%) used for transplantation, 102 kidneys functioned. There were no cases of bilateral nonfunctioning kidneys. The delayed graft function (DGF) rate was 86%; however, the death-censored graft survival was 80.0% at 5 years and 62.9% at 10 years. Kidneys implanted after more than 24 hours of total ischemia time required a significantly longer period of hemodialysis. Donor risk factors that affected graft survival included WIT >/= 20 minutes, donor age >/= 50 years, and serum creatinine level at admission > 1.0 mg/dL. CONCLUSIONS: Organ procurement without cannulation prior to cardiac arrest entailed a long WIT and a high DGF rate. However, the graft survival was good. It has been necessary to use grafts from NHBD despite the inherent risk factors. It is important to reduce kidney damage both at the organ procurement and during the posttransplant management.

Clinicopathological study of vesicoureteral reflux (VUR)-associated pyelonephritis in renal transplantation.

We retrospectively studied the occurrence of vesicoureteral reflux (VUR)-associated pyelonephritis using renal biopsies obtained from the transplanted kidneys, and correlated the histological changes with clinical parameters. Out of a total of 131 renal biopsies performed between 1990 and 2001 on renal transplant patients at the department of Urology of Nagasaki University Graduate School of Biomedical Sciences, 12 patients showed pyuria more than twice in a single year. Seven of these 12 patients were available for determining VUR by voiding cystourethrography (VCUG). Cystoureterography demonstrated VUR in three of seven studied patients with pyuria. A histopathological examination revealed dilatation of both proximal and distal tubules in renal biopsies of transplant patients with VUR, compared to renal biopsies of transplant patients without VUR, or non-transplanted patients with thin membrane disease. One of the patients with VUR showed advanced features of chronic pyelonephritis in four consecutive biopsies at different time points, suggesting a late stage of reflux nephropathy in the transplanted kidney. We conclude from our study that the occurrence of VUR-related pyelonephritis may be one of the important long-term complications in the survival of renal allografts.

Different clinicopathological courses of two recipients of kidneys retrieved from the same non-heart beating donor.

We report the clinicopathological courses of two recipients of kidneys retrieved from the same non-heart beating donor (NHBD). A 52-year-old man received a renal transplant from an NHBD. The donor was a 66-year-old woman who died of subarachnoid haemorrhage. The recipient was immunosuppressed by basiliximab, tacrolimus (TAC), mycophenolate mofetil (MMF), methyl prednisolone (MP), and antilymphocyte globulin (ALG). On post-operative day (POD) 21, haemodialysis therapy was withdrawn, however, their serum creatinine (s-Cr) level failed to improve. Four transplant biopsies were performed (1 h and POD 46, 74, and 114). The biopsy showed tubular degeneration but no evidence of TAC nephrotoxicity. The last biopsy after discontinuation of TAC demonstrated acute rejection of borderline grade. The s-Cr level at discharge was 5.0 mg/dL. The contra-lateral kidney was transplanted into a 31-year-old female and showed early functioning, with an s-Cr level at discharge of 1.8 mg/dL. Biopsy examination on POD 38 showed a recovery of tubular degeneration. The causes of delayed graft function and persistently high level of s-Cr in Case 1 remain unclear. Various factors, including donor-related factors, recipient-related factors, TAC nephrotoxicity, acute rejection, and urinary tract infection could all be associated with this condition.

Absence of mutations in the Wilms' tumor gene wt1 in de novo non-small cell lung cancers.

We recently demonstrated that the WT1 gene was overexpressed in the majority of de novo lung cancers regardless of cancer subtypes. Here, we examined WT1 genomic DNA in 38 cases of de novo non-small cell lung cancers (NSCLC) for mutations using direct sequencing. The sequencing analysis showed no mutations of WT1 genomic DNA in any of 38 de novo non-small cell lung cancers examined. These results indicated that the non-mutated, wild-type WT1 gene played an important role in de novo NSCLC.