Impact of respiratory bacterial infections on mortality in Japanese patients with COVID-19: a retrospective cohort study.

BACKGROUND: Although cases of respiratory bacterial infections associated with coronavirus disease 2019 (COVID-19) have often been reported, their impact on the clinical course remains unclear. Herein, we evaluated and analyzed the complication rates of bacterial infections, causative organisms, patient backgrounds, and clinical outcome in Japanese patients with COVID-19. METHODS: We performed a retrospective cohort study that included inpatients with COVID-19 from multiple centers participating in the Japan COVID-19 Taskforce (April 2020 to May 2021) and obtained demographic, epidemiological, and microbiological results and the clinical course and analyzed the cases of COVID-19 complicated by respiratory bacterial infections. RESULTS: Of the 1,863 patients with COVID-19 included in the analysis, 140 (7.5%) had respiratory bacterial infections. Community-acquired co-infection at COVID-19 diagnosis was uncommon (55/1,863, 3.0%) and was mainly caused by Staphylococcus aureus, Klebsiella pneumoniae and Streptococcus pneumoniae. Hospital-acquired bacterial secondary infections, mostly caused by Staphylococcus aureus, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia, were diagnosed in 86 patients (4.6%). Severity-associated comorbidities were frequently observed in hospital-acquired secondary infection cases, including hypertension, diabetes, and chronic kidney disease. The study results suggest that the neutrophil-lymphocyte ratio (> 5.28) may be useful in diagnosing complications of respiratory bacterial infections. COVID-19 patients with community-acquired or hospital-acquired secondary infections had significantly increased mortality. CONCLUSIONS: Respiratory bacterial co-infections and secondary infections are uncommon in patients with COVID-19 but may worsen outcomes. Assessment of bacterial complications is important in hospitalized patients with COVID-19, and the study findings are meaningful for the appropriate use of antimicrobial agents and management strategies.

Diagnostic significance of secondary bacteremia in patients with COVID-19.

OBJECTIVES: We investigated the occurrence of non-respiratory bacterial and fungal secondary infections, causative organisms, impact on clinical outcomes, and association between the secondary pathogens and mortality in hospitalized patients with coronavirus disease 2019 (COVID-19). METHODS: This was a retrospective cohort study that included data from inpatients with COVID-19 from multiple centers participating in the Japan COVID-19 Taskforce (April 2020 to May 2021). We obtained demographic, epidemiological, and microbiological data throughout the course of hospitalization and analyzed the cases of COVID-19 complicated by non-respiratory bacterial infections. RESULTS: Of the 1914 patients included, non-respiratory bacterial infections with COVID-19 were diagnosed in 81 patients (4.2%). Of these, 59 (3.1%) were secondary infections. Bacteremia was the most frequent bacterial infection, occurring in 33 cases (55.9%), followed by urinary tract infections in 16 cases (27.1%). Staphylococcus epidermidis was the most common causative organism of bacteremia. Patients with COVID-19 with non-respiratory secondary bacterial infections had significantly higher mortality, and a multivariate logistic regression analysis demonstrated that those with bacteremia (aOdds Ratio = 15.3 [5.97-39.1]) were at higher risk of death. Multivariate logistic regression analysis showed that age, male sex, use of steroids to treat COVID-19, and intensive care unit admission increased the risk for nosocomial bacteremia. CONCLUSIONS: Secondary bacteremia is an important complication that may lead to poor prognosis in cases with COVID-19. An appropriate medical management strategy must be established, especially for patients with concomitant predisposing factors.

Clinical Characteristics and Outcomes of Heart Failure Patients With Long-Term Care Insurance　- Insights From the Kitakawachi Clinical Background and Outcome of Heart Failure Registry.

BACKGROUND: In Japan, the long-term care insurance (LTCI) system has an important role in helping elderly people, but there have been no clinical studies that have examined the relationship between the LTCI and prognosis for patients with acute heart failure (HF).Methods and Results:This registry was a prospective multicenter cohort, 1,253 patients were enrolled and 965 patients with acute HF aged ≥65 years were comprised the study group. The composite endpoint included all-cause death and hospitalization for HF after discharge. We divided the patients into 4 groups: (i) patients without LTCI, (ii) patients requiring support level 1 or 2, (iii) patients with care level 1 or 2, and (iv) patients with care levels 3-5. The Kaplan-Meier analysis identified a lower rate of the composite endpoint in group (i) than in the other groups. After adjusting for potentially confounding effects using a Cox proportional regression model, the hazard ratio (HR) of the composite endpoint increased significantly in groups (iii) and (iv) (adjusted HR, 1.62; 95% confidence interval [CI], 1.22-1.98 and adjusted HR, 1.62; 95% CI, 1.23-2.14, respectively) when compared with group (i). However, there was no significant difference between groups (i) and (ii). CONCLUSIONS: The level of LTCI was associated with a higher risk of the composite endpoint after discharge in acute HF patients.

A decline in activities of daily living due to acute heart failure is an independent risk factor of hospitalization for heart failure and mortality.

BACKGROUND: Although activities of daily living (ADL) are recognized as being pertinent in averting relevant readmission of heart failure (HF) and mortality, little research has been conducted to assess a correlation between a decline in ADL and outcomes in HF patients. METHODS: The Kitakawachi Clinical Background and Outcome of Heart Failure Registry is a prospective, multicenter, community-based cohort of HF patients. We categorized the patients into four types of ADL: independent outdoor walking, independent indoor walking, indoor walking with assistance, and abasia. We defined a decline in ADL (decline ADL) as downgrade of ADL and others (non-decline ADL) as preservation of ADL before discharge compared with admission. RESULTS: Among 1253 registered patients, 923 were eligible, comprising 98 (10.6%) with decline ADL and 825 (89.4%) with non-decline ADL. Decline ADL exhibited a higher risk of hospitalization for HF and mortality compared with non-decline ADL. A multivariate analysis revealed that decline ADL emerged as an independent risk factor of hospitalization for HF [hazard ratio (HR), 1.42; 95% confidence interval (CI): 1.01-1.96; p=0.046] and mortality (HR, 1.95; 95% CI: 1.23-2.99; p<0.01). Although 66.3% of patients with decline ADL were registered for long-term care insurance, few received daycare services (32.7%) or home-visit medical services (8.2%). CONCLUSIONS: Decline in ADL is a predictor of hospitalization for HF and mortality in HF patients.

Increased amygdala reactivity following early life stress: a potential resilience enhancer role.

BACKGROUND: Amygdala hyper-reactivity is sometimes assumed to be a vulnerability factor that predates depression; however, in healthy people, who experience early life stress but do not become depressed, it may represent a resilience mechanism. We aimed to test these hypothesis examining whether increased amygdala activity in association with a history of early life stress (ELS) was negatively or positively associated with depressive symptoms and impact of negative life event stress in never-depressed adults. METHODS: Twenty-four healthy participants completed an individually tailored negative mood induction task during functional magnetic resonance imaging (fMRI) assessment along with evaluation of ELS. RESULTS: Mood change and amygdala reactivity were increased in never-depressed participants who reported ELS compared to participants who reported no ELS. Yet, increased amygdala reactivity lowered effects of ELS on depressive symptoms and negative life events stress. Amygdala reactivity also had positive functional connectivity with the bilateral DLPFC, motor cortex and striatum in people with ELS during sad memory recall. CONCLUSIONS: Increased amygdala activity in those with ELS was associated with decreased symptoms and increased neural features, consistent with emotion regulation, suggesting that preservation of robust amygdala reactions may reflect a stress buffering or resilience enhancing factor against depression and negative stressful events.

Clinical Characteristics and Social Frailty of Super-Elderly Patients With Heart Failure　- The Kitakawachi Clinical Background and Outcome of Heart Failure Registry.

BACKGROUND: Social background is important in preventing admission/readmission of heart failure (HF) patients. However, few clinical studies have been conducted to assess the social background of these patients, especially elderly patients.Methods and Results:The Kitakawachi Clinical Background and Outcome of Heart Failure (KICKOFF) Registry is a prospective multicenter community-based cohort of HF patients, established in April 2015. We compared the clinical characteristics and social background of the super-elderly group (≥85 years old) and the non-super-elderly group (<85 years old). This study included 647 patients; 11.8% of the super-elderly patients were living alone, 15.6% were living with only a partner, and of these, only 66.7% had the support of other family members. The super-elderly group had less control over their diet and drug therapies than the non-super-elderly group. Most patients in the super-elderly group were registered for long-term care insurance (77.4%); 73.5% of the super-elderly patients could walk independently before admission, but only 55.5% could walk independently at discharge, whereas 94% of the non-super-elderly patients could walk independently before admission and 89.4% could walk independently at discharge. CONCLUSIONS: The KICKOFF Registry provides unique detailed social background information of Japanese patients with HF. Super-elderly patients are at serious risk of social frailty; they need the support of other people and their ability to perform activities of daily living decline when hospitalized.

[Detectability of High Intensity Areas in FLAIR and Multi Shot EPI-FLAIR: Phantom Study].

In magnetic resonance imaging (MRI) of brain, fast spin echo-fluid attenuated inversion recovery (FSE-FLAIR) is widely used to detect high intensity areas (HIAs). The way of getting FLAIR contrast at high speed includes echo planar imaging-FLAIR (EPI-FLAIR), and in EPI-FLAIR there are single shot EPI-FLAIR (SS-EPI-FLAIR) and multi shot EPI-FLAIR (MS-EPI-FLAIR). There were negative opinions for the reports of SS-EPI-FLAIR, and it is reported that SS-EPI-FLAIR is able to acquire image quality that is equal to FSE-FLAIR in a shorter time, recently. But there are few reports that utilized contrast of MS-EPI-FLAIR. Our object was to compare HIA detectability in FSE-FLAIR and MS-EPI-FLAIR in equal imaging time, and to evaluate a basic characteristic. We dissolved indigestive dextrin in the aqua destillata and created a 0-46 wt% phantom. The concentration that correspond to T1, T2 value of brain white matter was 42 wt%. We calculated contrast by using signal intensities of each phantom, and compared contrast by signal intensities of each phantom, and compared the contrast of MS-EPI-FLAIR and FSE-FLAIR. In the range of 18-46 wt%, the contrast of MS-EPI-FLAIR was positive value, and that of FSE-FLAIR was 26-42 wt%. By the statistical test, contrast of MS-EPI-FLAIR in 18-26% was significantly different for FSE-FLAIR. In conclusion, it was suggestive that MS-EPI-FLAIR is able to detect HIA equally or sharply.

Effects of hepatocyte growth factor in myocarditis rats induced by immunization with porcine cardiac myosin.

OBJECTIVES: Myocarditis is considered one of the major causes of dilated cardiomyopathy. Hepatocyte growth factor (HGF) has pleiotropic activities that promote tissue regeneration and facilitate functional improvement of injured tissue. We investigated whether the epicardial sustained-release of HGF, using gelatin hydrogel sheets, improves cardiac function in a chronic myocarditis rat model. METHODS: Six weeks after Lewis rats were immunized with porcine cardiac myosin to establish autoimmune myocarditis, HGF- or normal saline (NS)-incorporated gelatin hydrogel sheets were applied to the epicardium (G-HGF and G-NS, respectively). At either 2 or 4 weeks after treatment, these were compared with the Control myocarditis group. Cardiac function was evaluated by echocardiography and cardiac catheterization. Development of fibrosis was determined by histological study and expression of transforming growth factor-ß1 (TGF-ß1). Bax and Bcl-2 levels were measured to evaluate apoptotic activity. RESULTS: At both points, fractional shortening and end-systolic elastance were higher in the G-HGF group than in the Control and G-NS groups (P < 0.01). Fractional shortening at 2 weeks of each group were as follows: 31.0 ± 0.9%, 24.8 ± 2.7% and 48.6 ± 2.6% (Control, G-NS and G-HGF, respectively). The ratio of the fibrotic area of the myocardium was lower in the G-HGF group than in the Control and G-NS groups at 2 weeks (G-HGF, 8.8 ± 0.9%; Control, 17.5 ± 0.2%; G-NS, 15.6 ± 0.7%; P < 0.01). The ratio at 4 weeks was lower in the G-HGF group than in the G-NS group (10.9 ± 1.4% vs 18.5 ± 1.3%; P < 0.01). The mRNA expression of TGF-ß1 in the G-HGF group was lower than in the Control group at 2 weeks (0.6 ± 0.1 vs 1.1 ± 0.2) and lower than that in the G-NS group at 4 weeks (0.7 ± 0.1 vs 1.3 ± 0.2). The Bax-to-Bcl-2 ratios at both points were lower in the G-HGF group than in the Control group. CONCLUSIONS: Sustained-released HGF markedly improves cardiac function in chronic myocarditis rats. The antifibrotic and antiapoptotic actions of HGF may contribute to the improvement. HGF-incorporated gelatin hydrogel sheet can be a new therapeutic modality for myocarditis.

A survey analysis of acoustic trauma related to MR scans.

PURPOSE: The maximum limit of MR scanner noise and necessity of ear protection is defined in the IEC standard (IEC60601-2-33) of MR safety. With improvements in MR scanner performance, pulse sequences generating higher scanning noise have been used clinically. In this study, we investigated the factors significantly related to potential acoustic trauma cases (PATC) after MR examinations. To consider the future direction for MR safety and prevention of acoustic trauma, issues related to noise generation by MR scanners and acoustic trauma were systematically reviewed. METHODS: A statistical analysis was performed using the data set from a survey (n=974) conducted in 2010 by the JSMRM safety committee. Hierarchical clustering analysis was used to extract the characteristics of the responders. With this classification as a reference, tests of independence and a residual analysis were employed to evaluate the factors related to PATC. RESULTS: No significant relationship was observed between the ear protection policy and the incidence or the reported outcome of PATC. While the two main clusters out of the six clusters extracted were associated with who reported the PATC and the confirmation process of the acoustic noise level of MR scanners, no cluster was associated with the frequency of PATC. An absence of PATC was significantly less reported (p=0.03) and more PATC was reported (p=0.04) by facilities with 3T MR systems. DISCUSSION: Although the total frequency was 4 cases, it should be noted that persistent hearing disturbances are a possible consequence of MR examinations. Neither the condition of the subjects nor the ear protection method was significantly related to the probability of PATC, suggesting the difficulty of predicting the potential risk of acoustic trauma. It is recommended to more systematically follow up PATC cases and clarify the risk factors.

Fibroproliferative changes on high-resolution CT in the acute respiratory distress syndrome predict mortality and ventilator dependency: a prospective observational cohort study.

OBJECTIVES: To examine whether the extent of fibroproliferative changes on high-resolution CT (HRCT) scan influences prognosis, ventilator dependency and the associated outcomes in patients with early acute respiratory distress syndrome (ARDS). DESIGN: A prospective observational cohort study. SETTING: Intensive care unit in a teaching hospital. PARTICIPANTS: 85 patients with ARDS who met American-European Consensus Conference Criteria and eligible criteria. INTERVENTIONS: HRCT scans were performed and prospectively evaluated by two independent observers on the day of diagnosis and graded into six findings according to the extent of fibroproliferation. An overall HRCT score was obtained by previously published method. PRIMARY AND SECONDARY OUTCOMES: The primary outcome was 60-day mortality. Secondary outcomes included the number of ventilator-free days, organ failure-free days, the incidence of barotraumas and the occurrence of ventilator-associated pneumonia. RESULTS: Higher HRCT scores were associated with statistically significant decreases in organ failure-free days as well as ventilator-free days. Multivariate Cox proportional hazards model showed that the HRCT score remained an independent risk factor for mortality (HR 1.20; 95% CI 1.06 to 1.36; p=0.005). Multivariate analysis also revealed that the CT score had predictive value for ventilator weaning within 28 days (OR 0.63; 95% CI 0.48 to 0.82; p=0.0006) as well as for an incidence of barotraumas (OR 1.61; 95% CI 1.08 to 2.38; p=0.018) and for an occurrence of ventilator-associated pneumonia (OR 1.46; 95% CI 1.13 to 1.89; p=0.004). A HRCT score <210 enabled prediction of 60-day survival with 71% sensitivity and 72% specificity and of ventilator-weaning within 28 days with 75% sensitivity and 76% specificity. CONCLUSIONS: Pulmonary fibroproliferation assessed by HRCT in patients with early ARDS predicts increased mortality with an increased susceptibility to multiple organ failure, including ventilator dependency and its associated outcomes.

Relevance of in vivo neurophysiological biomarkers for mild cognitive impairment and Alzheimer's disease.

Visuospatial dysfunction including defects in motion perception in Alzheimer's disease (AD) and mild cognitive impairment (MCI) are clues to search for potential in vivo biomarkers. In this review, we focus on the clinical relevance of non-invasive neurophysiological findings in event-related potentials (ERPs) and functional magnetic resonance imaging (fMRI) to assess visual dysfunction in AD and MCI. We first summarize the current concept of the parallel visual pathways in primates and humans. Next, we outline the results of previous electrophysiological and fMRI studies on visual function in AD and MCI. Finally, we present the recent findings of our systematic ERP and fMRI approach to visual perception in AD and MCI. Our overview strongly indicates that visual impairments in patients with AD and MCI are mainly caused by dysfunction in higher-level parallel visual pathways. In particular, a deficit in ventro-dorsal stream function related to optic flow perception is responsible for the earliest and most prominent visual symptoms in MCI. Therefore, we conclude that ERP and fMRI measurements for visual perception can be used as in vivo biomarkers for early functional brain changes in MCI and AD patients.

Impact of diabetes mellitus on outcomes in Japanese patients undergoing coronary artery bypass grafting.

BACKGROUND AND PURPOSE: There have been no large-scale studies on the impact of diabetes mellitus (DM) on outcomes in Japanese patients undergoing coronary artery bypass grafting (CABG). METHODS AND SUBJECTS: A multi-institutional retrospective cohort study was conducted in 14 Japanese centers. All adult patients who underwent isolated CABG from 2007 to 2008 were included (n=1522, mean age: 68.5years). The definitions of DM were all patients admitted with diagnosis of DM and preoperative glycated hemoglobin (Hb) A1c≥6.5%. Univariate and multivariate analyses were performed to identify the risk of morbidity and mortality. RESULTS: There were 849 DM and 572 non-DM patients. Preoperative mean HbA1c were 7.1% in the DM group and 5.7% in the non-DM group (p<0.0001). Preoperative, intraoperative, and 3-day average postoperative blood glucose (BG) were 146mg/dl, 172mg/dl, and 168mg/dl in the DM group, and 103mg/dl, 140mg/dl, and 136mg/dl in the non-DM group (all p<0.0001). Although there were no significant differences in postoperative cardiovascular events, the incidence of infection was significantly higher in the DM group than in the non-DM group (9.2% vs 6.1%, p=0.036) on the univariate analysis. The all-cause death was also relatively higher in the DM group than in the non-DM group (2.1% vs 1.1%, p=0.12), and this was likely related to infection. CONCLUSION: DM patients had worse perioperative BG control, higher incidence of infection, and higher mortality than non-DM patients. These results indicate that perioperative BG control guidelines should be standardized to obtain better surgical outcomes in Japanese DM patients.

Understanding the Pathophysiology of Alzheimer's Disease and Mild Cognitive Impairment: A Mini Review on fMRI and ERP Studies.

The prevalence of Alzheimer's disease (AD) is predicted to increase rapidly in the coming decade, highlighting the importance of early detection and intervention in patients with AD and mild cognitive impairment (MCI). Recently, remarkable advances have been made in the application of neuroimaging techniques in investigations of AD and MCI. Among the various neuroimaging techniques, functional magnetic resonance imaging (fMRI) has many potential advantages, noninvasively detecting alterations in brain function that may be present very early in the course of AD and MCI. In this paper, we first review task-related and resting-state fMRI studies on AD and MCI. We then present our recent fMRI studies with additional event-related potential (ERP) experiments during a motion perception task in MCI. Our results indicate that fMRI, especially when combined with ERP recording, can be useful for detecting spatiotemporal functional changes in AD and MCI patients.

[Surgical treatment for ischemic mitral regurgitation].

BACKGROUND: Ischemic mitral regurgitation (IMR) is characterized by annular dilation and restricted leaflet closure with increased leaflet tethering caused by displaced attachment of the papillary muscles. Our surgical strategy for IMR consists of mitral annuloplasty (MAP) and additional left ventricular restoration procedures as needed. When the left ventricular dilation and mitral tethering are mild, we perform MAP alone. On the other hand, we add papillary muscle approximation (PMA) through left ventriculotomy with or without infero-posteiror wall exclusion (the Batista procedure) when left ventricular dilatation and leaflet tethering are severe. METHODS: From November 2007 to April 2011, we surgically treated 19 patients with IMR at our institution. Of those, 13 patients underwent MAP alone (group M) and 6 patients underwent MAP and PMA (group P). RESULTS: There were no hospital deaths. Postoperatively, echocardiography showed no or mild mitral regurgitation (MR) in all patients except 1 patient in group M. There was significant improvement in left ventricular ejection fraction (LVEF) in both groups. Moreover, left ventricular size decreased significantly in both groups. In group P, the tethering height, area and papillary muscle distance also decreased significantly. There were no patients who developed recurrent MR postoperatively. However, in group P, there were 2 late deaths caused by congestive heart failure and sepsis, and remaining 3 patients suffered from congestive heart failure. In group M, there were no late deaths and all patients were in New York Heart Association (NYHA) class I or II. CONCLUSION: Our surgical strategy for IMR yields excellent reduction of MR. Especially the PMA provides promising effect on tethering reduction. However, the absence of recurrent MR was not associated with an improvement in symptoms and survival in patients who presented with severe left ventricular dilatation and leaflet tethering.

Surgical repair of late aortic dissection after cardiac surgery.

Late aortic dissection is a rare but serious complication associated with cardiac surgery. We report two cases of late aortic dissection that occurred after cardiac surgery. The management and review of the preoperative factors, which may predispose to this complication, are the subject of this case report.

Evaluation of RF heating due to various implants during MR procedures.

We evaluated radiofrequency (RF) heating of various implants embedded in a gel phantom during magnetic resonance (MR) procedures. We examined the dependence of RF heating on variation in specific absorption rate (SAR) and angle between the implant and the static magnetic field (B(0)) and on the displacement of the phantom in the irradiation coil using a 1.5-tesla MR system, and we compared the influence of RF heating on the same implant using a 3.0T MR system. Our results support the occurrence of RF heating of implants made of non-magnetizing metal. We observed greater RF heating when the implant was set parallel to B(0), embedded at a shallower depth, and placed at the center of the RF irradiation coil. We also confirmed that the rise in temperature was proportionate to the increase in SAR. We considered the difference in temperature elevation on depth of embedding to reflect the skin-depth effect of RF intensity for both the 1.5- and 3.0-T MR systems.

[Management of secondary normal pressure hydrocephalus and assessment of cortical reorganization using fMRI].

We assessed the motor recovery and cortical reorganization associated with intracranial pressure (ICP) control in a secondary normal pressure hydrocephalus (sNPH) patient. A 32-year-old man with sNPH resulting from a head injury presented with left hemiplegia. A ventricular-peritoneum shunt (VP shunt) was surgically inserted for the sNPH using a Codman Hakim Programmable Valve, and his ICP was controlled according to the ventricular size by CT scanning. The motor function of the patient was evaluated by functional MRI (fMRI) during ICP control in our hospital. The fMRI was performed at 3.0 T with timed dorsal flexion-extension movement of the foot. After 3 months of shunt valve pressure control, the primary sensorimotor cortex (SM1) was activated during the affected (left) foot movement, an area that had not been able to be activated just after admission. His walking ability also recovered markedly to the point of free independent walking. The motor function of the affected lower extremity appeared to recover to almost the some degree the original motor area after control of the ICP. This finding may reflect functional reorganization of the motor pathway following ICP normalization.

Evaluation of RF heating on hip joint implant in phantom during MRI examinations.

PURPOSE: We evaluate radiofrequency (RF) heating of two kinds of hip joint implants of different sizes, shapes and materials. Temperature rises at various positions of each implant are measured and compared with a computer simulation based on electromagnetic-field analysis. METHODS: Two kinds of implants made of cobalt-chromium alloy and titanium alloy were embedded at a 2-cm depth of tissue-equivalent gel-phantom. The phantom was placed parallel to the static magnetic field of a 1.5 T MRI device. Scans were conducted at the specific absorption rate of 2.5 W/kg for 15 min, and temperatures were recorded with RF-transparent fiberoptic sensors. Temperatures of the implant surface were measured at 6 positions, from the tip to the head. Measured temperature rises were compared with the results of electromagnetic-field analysis. RESULTS: The maximum temperature rise was observed at the tip of each implant, and it was 9.0 degrees C for the cobalt- chromium implant and 5.3 degrees C for the titanium implant. The simulated heating positions with electromagnetic-field analysis accorded with experimental results. However, a difference in temperature rise was seen with the titanium implant. CONCLUSION: RF heating was confirmed to take place at both ends of the implants in spite of their different shapes. The maximum temperature rise was observed at the tip where there is large curvature. The value was found to depend on physical properties of the implant materials. The discrepancy between experimental and simulated temperature rises was presumed to be the result of an incomplete model for the titanium implant.

[Solid malignancy in patients who received cyclosporine for fibrosing interstitial pneumonia].

OBJECTIVE: Since more solid malignancies are observed in transplant recipients treated with cyclosporine (CsA) than in healthy persons. We sought to describe the incidence of malignancy in patients treated with CsA for fibrosing interstitial pneumonia. METHODS: We prospectively reviewed 43 patients who received CsA and prednisolone for fibrosing interstitial pneumonia over 180 days at our hospital between April 2004 and October 2008. The duration of CsA treatment was 632 +/- 364 days. RESULTS: Malignancy developed in 6 (14.0%) patients. Time to diagnosis after medical intervention ranged from 394 days to 1325 days (mean, 783 days). Non-small cell lung cancer was diagnosed in 4 cases. These were discovered by routine computed tomography in all cases. Hepatocellular carcinoma and gastric cancer were each diagnosed in 1 case, respectively. Incidence of malignancy tended to be higher in patients who had been treated with CsA for 567 days or more than in those who had been treated for less than 567 days, but this was not statistically significant. CONCLUSION: Our results highlight the need for close follow-up for patients who receive CsA for over 2 years. This could lead to cancer detection at an early stage.

Prolonged mechanical unloading preserves myocardial contractility but impairs relaxation in rat heart of dilated cardiomyopathy accompanied by myocardial stiffness and apoptosis.

OBJECTIVE: Left ventricular assist devices are used in patients with end-stage dilated cardiomyopathy as a "bridge to recovery." However, physiologic and histologic changes under prolonged mechanical unloading have not been elucidated. Thus, we investigated these changes in the rat heart with dilated cardiomyopathy under mechanical unloading after heterotopic transplantation. METHODS: Six weeks after induction of autoimmunized dilated cardiomyopathy in Lewis rats, 2 types of hearts were compared (n = 6 each): (1) an unloaded dilated cardiomyopathy heart (DCM-UL) and (2) a dilated cardiomyopathy heart (DCM). The hearts were evaluated 2 and 4 weeks after transplantation. RESULTS: Four weeks after transplantation, developed tension of the papillary muscle (indicator of myocardial contractility) and ß-adrenergic response to isoproterenol were better in DCM-UL than in DCM (P = 0.0025 and P <0.0001, respectively). However, half-relaxation time of the papillary muscle (indicator of myocardial relaxation) was worse in the DCM-UL group (P < .0001). The ratio of the fibrotic area of the myocardium and the number of terminal dUTP nick end-labeling-positive myocytes (indicator of myocardial apoptosis) were higher in DCM-UL than in DCM (P = .0072 and P = .0039, respectively). The mRNA expression of collagen Ia was also higher in DCM-UL. CONCLUSIONS: Mechanical unloading preserved myocardial contractility and ß-adrenergic response but worsened myocardial relaxation. Furthermore, prolonged mechanical unloading has a tendency to increase the ratio of the fibrotic area and myocardial apoptosis. These unfavorable responses, although secondary to prolonged mechanical unloading, may have a negative impact on the bridge to recovery in patients with dilated cardiomyopathy.