Enhancement of Hemocompatibility of the MERA Monopivot Centrifugal Pump: Toward Medium‐Term Use

The MERA monopivot centrifugal pump has been developed for use in open‐heart surgery, circulatory support, and bridge‐to‐decision for up to 4 weeks. The pump has a closed‐type, 50‐mm diameter impeller with four straight paths. The impeller is supported by a monopivot bearing and is driven by a radial‐flux magnet‐coupling motor. Because flow visualization experiments have clarified sufficient pivot wash and stagnation at the sharp corner of the pivot support was suggested, sharp corners were removed in the design stage. The index of hemolysis of the pump operating at more than 200 mm Hg was found to be lower than that of a commercial pump. Four‐week animal tests were then conducted two times; improvement of thrombus formation was seen in the female pivot through modification of female pivot geometry. Overall antithrombogenicity was also recorded. Finally, to assure mid‐term use, an additional 4‐week durability test revealed that the rate of the axial pivot wear was as small as 1.1 µm/day. The present in vitro and in vivo studies revealed that the MERA monopivot centrifugal pump has sufficient hemocompatibility and durability for up to 4 weeks.     

Pathophysiological analysis of nonalcoholic fatty liver disease by evaluation of fatty liver changes and blood flow using xenon computed tomography: can early-stage nonalcoholic steatohepatitis be distinguished from simple steatosis?

Introduction

Effective noninvasive tests that can distinguish early-stage nonalcoholic steatohepatitis (NASH) from simple steatosis (SS) have long been sought. Our aim was to determine the possibility of noninvasively distinguishing early-stage NASH from SS.

Materials and methods

We used Fick’s principle and the Kety–Schmidt equation to determine the hepatic tissue blood flow (TBF) in 65 NASH patients who underwent xenon computed tomography (Xe-CT). We calculated the lambda value (LV), i.e., Xe gas solubility coefficient, in liver and blood. We assessed the histological severity of fatty changes and fibrosis on the basis of Brunt’s classification. Liver biopsy revealed SS in 9 patients and NASH in 56 patients. NASH stages 1 and 2 were classified as early-stage NASH (Ea-NASH; 38 patients) and stages 3 and 4 as advanced-stage NASH (Ad-NASH; 18 patients). We evaluated the differences in LV and TBF among the 3 groups.

Results

LV was significantly lower in the Ad-NASH group than in the SS and Ea-NASH groups. Portal venous TBF (PVTBF) was significantly lower in the Ea-NASH group than in the SS group, and PVTBF was lower in the Ad-NASH group than in the Ea-NASH group. Total hepatic TBF (THTBF) was significantly different between the SS and Ea-NASH groups and between the SS and Ad-NASH groups.

Conclusions

In conclusion, measurements of TBF and LV are useful for evaluating the pathophysiological progression of NASH. In addition, these measurements can facilitate the differential diagnosis of SS and Ea-NASH, which may not be distinguishable by other means.     

Comparison of characteristics and therapeutic efficacy in rheumatoid arthritis patients treated by rheumatologists and those treated by orthopedic surgeons under a team medicine approach at the same institute

The treatment of rheumatoid arthritis (RA) has improved dramatically with the advent of the latest generation of disease-modifying antirheumatic drugs. Despite these advances, in some patients inflammation is not diminished sufficiently to prevent irreversible musculoskeletal damage, thereby necessitating surgical intervention to reduce pain and improve function. For RA treatment, Japanese orthopedic surgeons also prescribe medication. In this study, we examined whether this Japanese system is effective for RA treatment. We analyzed the clinical condition of RA patients treated by rheumatologists and those treated by orthopedists in a linked registry study using information from a large observational cohort of RA patients followed every half year from 2000 to 2010 (the IORRA cohort). Two groups of patients were compared: patients treated by rheumatologists (rheumatologic group) and patients treated by orthopedists (orthopedic group). The results revealed that patients in the orthopedic group were older, more likely to be female, and had a longer disease duration than patients in the rheumatologic group. The proportion of patients with a history of joint surgery was also much higher in the orthopedic group than in the rheumatologic group. The average scores on the Japanese version of the Health Assessment Questionnaire, and the remission ratio determined using a Boolean-based definition gradually increased from 2000 until 2010, and these findings were consistently better in the rheumatologic group than in the orthopedic group. These data suggest that patients treated primarily by orthopedists are more likely to have long-standing RA compared to patients treated by rheumatologists. Therefore, it is critical for rheumatologists and orthopedists to complement each other medically in the treatment of RA patients.     

A case of adult-onset Still's disease (AOSD)-like manifestations abruptly developing during confirmation of a diagnosis of metastatic papillary thyroid carcinoma

A 68-year-old Japanese man was admitted to our hospital suffering from abrupt onset of high fever accompanied by arthralgia, myalgia, sore throat, macular eruption, and liver dysfunction. Six months before the onset of these manifestations, (18)F-fluoro-deoxy-glucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) had detected, unexpectedly, three calcified thyroid lesions without (18)F-FDG uptake. Two months before the onset of the present manifestations, ultrasonography-guided fine-needle aspiration had led to a diagnosis of papillary thyroid carcinoma (PTC). Soon after the occurrence of the rheumatic manifestations, a subsequent (18)F-FDG PET/CT scan showed not only the three thyroid lesions, the same as those in the previous scan, but also (18)F-FDG uptake in the thyroid lesion. A diagnosis of adult-onset Still's disease (AOSD)-like manifestations associated with PTC was made, and treatment with 40?mg/day of prednisolone (PSL) resolved the symptoms promptly. PSL was gradually tapered, without recurrence of the (AOSD)-like manifestations. Five months after the initiation of treatment with PSL, total thyroidectomy, followed by (131)I thyroid ablation treatment, was performed while the patient was on a PSL dose of 18?mg/day. Seven months after the thyroidectomy, the dose of PSL was tapered to 2?mg/day, and neither the AOSD-like manifestations nor the PTC relapsed. On confirming a diagnosis of AOSD, it may be necessary to consider the presence of an associated malignancy, including solid tumors such as PTC.