Sensitivity, robustness, and reproducibility of U-shaped delamination test for evaluation of candidate ultra-high molecular weight polyethylene materials for joint replacements.

The delamination of ultra-high molecular weight polyethylene (UHMWPE) in artificial joints is a major cause limiting the long-term clinical results of arthroplasty. However, the conventional test method using simple reciprocation to evaluate the delamination resistance of UHMWPE materials has insufficient detection sensitivity. To reproduce delamination, the unconformity contact must be maintained throughout the test so that the maximum stress is generated below the surface. Therefore, a test method that applies a U-shaped motion comprising two long-linear and one short linear sliding motion was developed. The sensitivity, robustness, and reproducibility of the U-shaped delamination test were investigated and compared with the traditional test method. The traditional test method could reproduce delamination only in materials that had degraded considerably, whereas the U-shaped delamination test could reproduce delamination in a wide range of materials, demonstrating its superior sensitivity. Additionally, using a higher load helped accelerate the test without affecting the test results. The optimal length of the short linear sliding motion was confirmed to be 1 mm. Finally, the inter-laboratory reproducibility of the U-shaped delamination test was confirmed using the round-robin test. The U-shaped delamination test demonstrates high sensitivity, robustness, and reproducibility and contributes to the selection and development of UHMWPE materials and artificial joints with a lower risk of delamination.

Crystal-Like Atomic Arrangement and Optical Properties of 25La2O3-75MoO3 Binary Glasses Composed of Isolated MoO42.

Transparent and brown La2O3-MoO3 binary glasses were prepared in bulk form using a levitation technique. The glass-forming range was limited, with the primary composition being approximately 25 mol % La2O3. The 25La2O3-75MoO3 glass exhibited a clear crystallization at 546 °C, while determining its glass transition temperature was difficult. Notably, despite its amorphous nature, the glass possessed a density and packing density comparable to those of crystalline La2Mo3O12. X-ray absorption fine structure and Raman scattering analyses revealed that the glass structure closely resembles La2Mo3O12 due to the presence of isolated MoO42- units, whereas disordered atomic arrangement around La atoms was confirmed. The glass demonstrated transparency ranging from 378 to 5500 nm, and the refractive index at 1.0 µm was estimated to be 2.0. The optical bandgap energy was 3.46 eV, which was slightly smaller than that of La2Mo3O12. Additionally, the glass displayed a transparent region ranging from 6.5 to 8.0 µm. This occurrence results from the decreased diversity of MoOn units and connectivity of Mo-O-Mo, which resulted in the reduced overlap of multiphonon absorption. This glass formation, with its departure from conventional glass-forming rules, resulted in distinctive glasses with crystal-like atomic arrangements.

Lipid index to quantify the absorbed lipids in retrieved UHMWPE components of joint arthroplasty.

BACKGROUND: The ultra-high molecular weight polyethylene (UHMWPE) component of artificial joints is one of the most important factors affecting the clinical outcomes of joint arthroplasty. Although the possibility of in vivo UHMWPE degradation caused by absorbed lipids has been reported, a quantitative evaluation of this phenomenon has not yet been performed. OBJECTIVE: This study aimed to establish the lipid index (LI) as a quantitative indicator of the amount of absorbed lipids and the first step to quantify their effects on UHMWPE. METHODS: The LI was defined using the infrared spectrum obtained with a Fourier-transform infrared spectrophotometer and verified using the retrieved UHMWPE components. RESULTS: The LI was consistent with the amount of extract recovered in reflux extraction with hexane. In addition, the LI could replace lipid extraction for calculating the oxidation index (OI) because the value obtained by subtracting the LI from the OI showed good agreement with the OI obtained after lipid extraction. CONCLUSION: The LI represents the amount of lipids absorbed by UHMWPE and is useful for quantitatively evaluating the effects of lipids on UHMWPE. In addition, the LI enables OI measurements that are unaffected by absorbed lipids without requiring troublesome lipid-extraction procedures.

Practice and Safety of Static Balloon Atrial Septostomy Based on a Nationwide Registry Data.

BACKGROUND: Balloon atrial septostomy (BAS) is an essential catheterization procedure for congenital heart lesions. Recently, a balloon catheter for static BAS was approved for the first time in Japan as an alternative to the conventional pull-through BAS. Despite the expected increase in the use of static BAS, reports on its safety are scarce worldwide.Methods and Results: Data on static and pull-through BAS registered in a national registry between 2016 and 2018 were collected. During the study period, 247 sessions of static BAS and 588 sessions of pull-through BAS were performed on a total of 674 patients. Patients who underwent static BAS were older (P<0.001). The incidence of serious adverse events (4.3% vs. 0.9%, P=0.03) and the overall incidence of adverse events (8.1% vs. 3.2%, P=0.03) were higher in static BAS than in pull-through BAS. Among patients who underwent static BAS, the risk factor for adverse events was a body weight <3 kg at the time of the procedure (odds ratio: 4.3 [confidence interval: 1.7-11], P=0.003). CONCLUSIONS: This nationwide study revealed differences in patient background between static and pull-through BAS, as well as a higher incidence of adverse events related to static BAS. Patients weighing <3 kg are at high risk for adverse events after static BAS and may require surgical and circulatory support backup.

In Vitro Measurement of Contact Pressure Applied to a Model Vessel Wall during Balloon Dilation by Using a Film-Type Sensor.

Objective: As an important evaluation index of vascular damage, the study aims to clarify the value of contact pressure applied to blood vessels and how it changes with respect to balloon pressure during balloon dilation. Methods: The contact pressure was evaluated through an in vitro measurement system using a model tube with almost the same elastic modulus as the blood vessel wall and our film-type pressure sensor. A poly (vinyl alcohol) hydrogel tube with almost the same elastic modulus was fabricated as the model vessel. The film-type sensor was inserted between the balloon catheter and the model vessel, and the balloon was dilated. Results: The contact pressure applied to the blood vessel was less than 10% of the balloon pressure, and the increase in contact pressure was less than 1% of the increase in balloon pressure (8 to 14 atm). Moreover, the contact pressure and its increase were larger in the model with a high elastic modulus. Conclusion: The contact pressure to expand the soft vessel model was not high, and the balloon pressure almost appeared to act on the expansion of the balloon itself. Our experiment using variable stiffness vessel models containing film-type sensors showed that the contact pressure acting on the vessel wall tended to increase as the wall became harder, even when the nominal diameter of the balloon was almost identical to the vessel. Our results can be clinically interpreted: when a vessel is stiff, the high-pressure inflation may rupture it even if its nominal diameter is identical to the diameter of the vessel.

In vitro evaluation of delamination resistance of PEEK and CFR-PEEK.

Poly-ether-ether-ketone (PEEK) and carbon fiber reinforced PEEK as orthopedic implant materials exhibit excellent material properties. Although delamination of PEEK materials has been reported in knee joint wear research, the delamination resistance behavior remains unclear. In this study, the delamination resistance of PEEK materials was investigated; these materials were compared to ultra-high molecular weight polyethylene (UHMWPE). The results of a ball-on-flat type delamination test indicated that the PEEK materials underwent delamination considerably earlier than UHMWPE, and the contact area of the PEEK materials was smaller than that of UHMWPE. Moreover, the indentation modulus, hardness, and coefficient of friction were higher for PEEK materials than for UHMWPE. The reduced tendency of PEEK materials to undergo deformation to mitigate stress concentration at low conformity contact conditions contributed to their inferior delamination resistance compared to that of UHMWPE. The delamination resistance of the PEEK materials was equivalent to that of degraded UHMWPE, which highlights the risk of delamination of PEEK implants in a clinical context. Consequently, when using PEEK materials as an implant component loaded at a low conformity contact condition, the material selection and component design must be carefully considered. Overall, the results of this study can help guide the future development of PEEK-based implants.

Deep groundwater physicochemical components affecting actinide migration.

To better understand the migration behavior of actinides in deep groundwater (GW), the interactions between doped tracers and deep GW components were investigated. La, Sm, Ho, and U tracers (10 or 100 ppb) were doped into sedimentary rock GW samples collected from 250 to 350 m deep boreholes in the experimental gallery of the Horonobe Underground Research Laboratory (URL), Hokkaido, Japan. To evaluate the effect of GW composition on the chemical speciation of actinides, the same tracers were doped into crystalline rock GW samples collected from 300 to 500 m deep boreholes in the experimental gallery at the Mizunami URL, Gifu Prefecture, Japan. Each GW sample was sequentially filtered through a micro-pore filter (0.2 µm) and ultrafilters with a 10 kDa nominal molecular weight limit. Next, the filtrate solutions were analyzed using inductively coupled plasma-mass spectrometry to determine the concentration of tracers retained in solution during each filtration step, and the used filters were analyzed using time-of-flight secondary ion mass spectrometry element mapping and X-ray absorption fine structure spectroscopy to determine the chemical species of the tracers trapped on each filter. It was determined that lanthanide migration was controlled by the amount of phosphates in the Horonobe GW. Therefore, it was expected that the solubility of minor actinides (MAs), which exhibit a similar chemical behavior to that of lanthanides, would be controlled by the formation of phosphates in sedimentary rock GW. Moreover, the data on the Mizunami GW indicated that a fraction of lanthanides and MAs formed hydroxides and/or hydroxocarbonates.

Stent Implantation for Congenital Heart Diseases in Japan　- Comprehensive Analysis From the Japanese Society of Congenital Interventional Cardiology Registry.

BACKGROUND: Stent implantation for vascular stenosis associated with congenital heart diseases is commonly performed as an off-label procedure in Japan because there is no officially approved stent for any congenital heart disease.Methods and Results:We analyzed data from the Japanese Society of Congenital Interventional Cardiology Registry collected from January 2016 to December 2018. Patients who underwent stent implantation were enrolled in the present analysis. During the study period, there were 470 procedures, 443 sessions, and 391 cases. Of 443 sessions, 427 (96.4%) succeeded procedurally. There were no differences in the procedural success rates among age groups. In all, 416 sessions (367 patients; 94%) resulted in survival to 30 days after catheter intervention. Of 392 admissions, 357 patients (91%) survived to discharge. Only 4 deaths were directly related to stent implantation. Some in-hospital complications were observed during 55 of 443 sessions. Both hospital deaths and serious complications were significantly more frequent in the group with various preoperative risk factors. CONCLUSIONS: Although not officially approved for congenital heart diseases in Japan, stent implantation in congenital heart diseases has been widely and routinely performed for many years with safety and efficacy. The aim of stenting was variable and broad because of many different applications and morphological variations. These data may facilitate approval of such an important device in Japan.

Implementation of computer simulation to assess flow diversion treatment outcomes: systematic review and meta-analysis.

INTRODUCTION: Despite a decade of research into virtual stent deployment and the post-stenting aneurysmal hemodynamics, the hemodynamic factors which correlate with successful treatment remain inconclusive. We aimed to examine the differences in various post-treatment hemodynamic parameters between successfully and unsuccessfully treated cases, and to quantify the additional flow diversion achievable through stent compaction or insertion of a second stent. METHODS: A systematic review and meta-analysis were performed on eligible studies published from 2000 to 2019. We first classified cases according to treatment success (aneurysm occlusion) and then calculated the pooled standardized mean differences (SMD) of each available parameter to examine their association with clinical outcomes. Any additional flow diversion arising from the two common strategies for improving the stent wire density was quantified by pooling the results of such studies. RESULTS: We found that differences in the aneurysmal inflow rate (SMD -6.05, 95% CI -10.87 to -1.23, p=0.01) and energy loss (SMD -5.28, 95% CI -7.09 to -3.46, p<0.001) between the successfully and unsuccessfully treated groups were indicative of statistical significance, in contrast to wall shear stress (p=0.37), intra-aneurysmal average velocity (p=0.09), vortex core-line length (p=0.46), and shear rate (p=0.09). Compacting a single stent could achieve additional flow diversion comparable to that by dual-stent implantation. CONCLUSIONS: Inflow rate and energy loss have shown promise as identifiers to discriminate between successful and unsuccessful treatment, pending future research into their diagnostic performance to establish optimal cut-off values.

Diploid Male Gametes Circumvent Hybrid Sterility Between Asian and African Rice Species.

In F1 hybrids of Oryza sativa (Asian rice) and Oryza glaberrima (African rice), heterozygosity leads to a complete gamete abortion because of allelic conflict at each of the 13 hybrid sterility (HS) loci. We systematically produced 19 plants from the F1 hybrids of both the rice species by the anther culture (AC) method. Five of the 19 interspecific hybrid plants were partially fertile and able to produce seeds. Unlike ordinal doubled haploid plants resulting from AC, these regenerated plants showed various ploidy levels (diploid to pentaploid) and different zygosities (completely homozygous, completely heterozygous, and a combination). These properties were attributable to meiotic anomalies in the interspecific hybrid F1 plants. Examination of the genetic structures of the regenerated plants suggested meiotic non-reduction took place in the interspecific hybrid F1 plants. The centromeric regions in the regenerated plants revealed that the abnormal first and/or second divisions of meiosis, namely the first division restitution (FDR) and/or second division restitution (SDR), had occurred in the interspecific hybrid. Immunohistochemical observations also verified these phenomena. FDR and SDR occurrences at meiosis might strongly lead to the formation of diploid microspores. The results demonstrated that meiotic anomalies functioned as a reproductive barrier occurred before the HS genes acted in gamete of the interspecific hybrid. Although such meiotic anomalies are detrimental to pollen development, the early rescue of microspores carrying the diploid gamete resulted in the fertile regenerated plants. The five partially fertile plants carrying tetraploid genomes with heterozygous alleles of the HS loci produced fertile diploid pollens, implying that the diploid gametes circumvented the allelic conflicts at the HS loci. We also proposed how diploid male gametes avoid HS with the killer-protector model.

Preliminary study of eye tracking to investigate the differences in gaze behaviors depending on the experience of neuroendovascular therapy.

BACKGROUND: Neuroendovascular therapy is now the choice for the management of many neurovascular pathologies, and physicians with endovascular skills are in high demand. In addition to the traditional method of practicing hand movements to learn skills, a new strategy of practicing eye movements to learn skills is also attracting attention. This preliminary study explored the differences in gaze behavior depending on experience with endovascular procedures to be facilitated in future skill training in neuroendovascular therapy. METHODS: Four physicians with experience of 3-412 neuroendovascular procedures wore eye-tracking devices during coil embolization of swine cervical arteries. Gaze metrics with direct correlations to the expertise of endovascular procedures were explored. RESULTS: Gaze metrics with a positive direct correlation to experience included the proportion of fixation durations (PFD) in the screen area and the native images. Those with a negative direct correlation included the PFD in the off-screen area and the roadmap images and the average fixation durations in the off-screen and coil areas. During the parent artery occlusion procedure with detachable coils, more experienced operators preferred to look at native images rather than roadmap images and that less experienced operators tended to look down at their hands more frequently. CONCLUSION: This preliminary study demonstrated the feasibility of eye tracking to identify the differences in gaze behavior depending on the experience of endovascular procedures and may guide future eye-tracking studies in neuroendovascular therapy.

In vitro estimation of reduction in strength and wear resistance of UHMWPE for joint prostheses due to lipid-induced degradation.

Ultra-high molecular weight polyethylene (UHMWPE) is used as a bearing surface of joint prostheses and has been reported to absorb lipids such as squalene (SQ) and cholesterol esters in vivo. These lipids have been suggested by in vitro studies using SQ as a model lipid to have the potential to induce polymer degradation. However, the impact of lipid-induced degradation on the strength and wear resistance of UHMWPE is unknown. In this study, lipid-induced degradation was simulated by SQ absorption and subsequent accelerated aging, and its influence on the strength and wear resistance of UHMWPE was investigated using wear, fatigue crack growth, and delamination testing. Lipid-induced degradation was found to have little impact on fatigue crack growth rates and delamination resistance. These results were consistent with previous reports that lipid-induced degradation is localized near the surface. However, we also found that lipid-induced degradation increased the wear rate of both non-crosslinked and crosslinked UHMWPE by a factor of 2.5 and 14, respectively. These results indicate that lipid-induced degradation may affect the durability and long-term clinical outcome of joint replacements due to increased wear of UHMWPE.

A novel method to eliminate the influence of absorbed lipids on the characterization of ultra-high molecular weight polyethylene using Fourier-transform infrared spectroscopy.

BACKGROUND: Fourier-transform infrared spectroscopy (FTIR) is one of the standard methods to analyze ultra-high molecular weight polyethylene (UHMWPE) in orthopedic implants. For retrieved components, lipid extraction using an organic solvent prior to the measurement is necessary to eliminate the influence of lipids absorbed in vivo. However, its influence on the measurement has not been substantially investigated. OBJECTIVE: To investigate the influence of lipid extraction on the FTIR analysis of UHMWPE and to develop a novel method to obtain reliable results without inconvenient lipid extraction. METHODS: FTIR analysis was repeatedly performed on UHMWPE specimens from retrieved components before and after lipid extraction under various conditions. A method to calculate the extent of influence of the absorbed lipids from the FTIR spectra was developed using a peak separation technique. RESULTS: An elevated temperature was necessary for lipid extraction; however, it had the potential to influence the results if the conditions were not properly controlled. The results obtained using the peak separation technique coincided with those obtained after lipid extraction. CONCLUSION: The use of the peak separation technique enables the efficient acquisition of reliable results without the need for lipid extraction.

Preliminary Study of Eye-Tracking During the Coil Insertion Task in a Silastic Model of Intracranial Aneurysms.

OBJECTIVE: Surgical skills are generally acquired by watching the "hand movements" of experts. "Eye movements" are now attracting attention in skill-learning fields. Eye-tracking technology was introduced preliminarily to develop a better skill-learning system for neuroendovascular treatments. METHODS: During a task to place a detachable coil into a silastic cerebral aneurysm model under biplane X-ray fluoroscopy, gaze points were recorded using a head-mount eye-tracking device. RESULTS: During the task, 91% of fixations were allocated to the monitor displaying fluoroscopic images, and the others to the hands of operators or unspecified visual targets. More than 80% of fixations were located in frontal or lateral fluoroscopic images. Fixations were placed more frequently around the aneurysm than the microcatheter. One operator failed to recognize the timing when the proximal marker of the coil overlapped that of the microcatheter. The subject allocated most fixations to the frontal fluoroscopic image, whereas other subjects placed most fixations to the lateral fluoroscopic image. Furthermore, that operator put no fixations to the proximal marker of the microcatheter. CONCLUSIONS: The results of this preliminary study imply the feasibility of the eye tracking-based learning system for neuroendovascular treatments. The eye-tracking analysis has potential in investigating or preventing procedural failures in neuroendovascular treatments.

Evaluating the durability of UHMWPE biomaterials used for articulating surfaces of joint arthroplasty using delamination tests.

Ultra-high molecular weight polyethylene (UHMWPE) is the most popular material used for the articulating surface of joint replacements. Delamination is a common fatigue-related failure mode in UHMWPE components; however, the relationship between delamination resistance and fatigue crack growth has not been reported. Here, the delamination resistance of contemporary UHMWPE materials, including highly cross-linked UHMWPE (HXLPE), vitamin E blended UHMWPE (VEPE), and vitamin E blended HXLPE (VEXLPE), was measured to verify a previously proposed accelerated test method using a U-shaped sliding motion; the results were compared with those of fatigue crack growth tests. The oxidative stability of each material was estimated using Fourier transform infrared analysis. UHMWPE sterilized by gamma irradiation in an inert atmosphere and annealed HXLPE had lower delamination resistance than virgin UHMWPE after artificial aging. This was consistent with previous findings from retrieval studies, and in vitro knee simulator and ball-on-flat unidirectional reciprocation wear studies. In contrast, remelted HXLPE, VEPE, and VEXLPE showed excellent delamination resistance after artificial aging. The results of the delamination tests were not consistent with those of fatigue crack growth tests, indicating the complex delamination mechanism and importance of evaluating these factors separately. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 107B: 65-72, 2019.

Anther culture in rice proportionally rescues microspores according to gametophytic gene effect and enhances genetic study of hybrid sterility.

BACKGROUND: To investigate plant hybrid sterility, we studied interspecific hybrids of two cultivated rice species, Asian rice (Oryza sativa) and African rice (O. glaberrima). Male gametes of these hybrids display complete sterility owing to a dozen of hybrid sterility loci, termed HS loci, but this complicated genetic system remains poorly understood. RESULTS: Microspores from these interspecific hybrids form sterile pollen but are viable at the immature stage. Application of the anther culture (AC) method caused these immature microspores to induce callus. The segregation distortion of 11 among 13 known HS loci was assessed in the callus population. Using many individual calli, fine mapping of the HS loci was attempted based on heterozygotes produced from chromosome segment substitution lines (CSSLs). Transmission ratio distortion (TRD) from microspores was detected at 6 of 11 HS loci in the callus population. The fine mapping of S 1 and S 19 loci using CSSLs revealed precise distances of markers from the positions of HS loci exhibiting excessive TRD. CONCLUSIONS: We demonstrated that AC to generate callus populations derived from immature microspores is a useful methodology for genetic study. The callus population facilitated detection of TRD at multiple HS loci and dramatically shortened the process for mapping hybrid sterility genes.

Mechanism of Cs Removal from Fukushima Weathered Biotite by Heat Treatment with a NaCl-CaCl2 Mixed Salt.

An in situ extended X-ray absorption fine structure (in situ EXAFS) spectroscopic analysis at high temperature was conducted to investigate the mechanism of Cs removal from weathered biotite (WB) from Fukushima, induced by heating with a mixed salt of NaCl and CaCl2. This indicated that most Cs remained in WB during heating at 200-700 °C. In addition, the in situ EXAFS spectra gradually changed on heating with the mixed salt and a completely different spectrum was observed for the sample after cooling from 700 °C to room temperature (RT). Ex situ EXAFS measurements and X-ray fluorescence analyses were also conducted on samples after heat treatment and removal of the mixed salt to clarify the temperature dependence of the Cs removal ratio. On the basis of the results of radial structure function analysis obtained from in situ EXAFS, we concluded that almost all of the Cs was removed from WB by heating at 700 °C with the mixed salt, and that Cs formed Cs-Cl bonds after cooling to RT from 700 °C. In contrast, although more than half of the Cs present was removed from WB by heat treatment at 500 °C, most Cs was surrounded by silica tetrahedrons, maintained by Cs-O bonds. On the basis of these results, different Cs removal processes are suggested for the high-temperature (600-700 °C) and low-temperature (400-500 °C) regions.

Age-Related Changes in Soluble Vascular Endothelial Growth Factor Receptor 1 (sVEGFR1) and Receptor 2 (sVEGFR2) in Healthy Japanese Subjects.

We measured serum soluble vascular endothelial growth factor receptor 1 (sVEGFR1) and receptor 2 (sVEGFR2) levels in healthy Japanese individuals in order to establish a reference value using a specific ELISA. Significant differences were observed in serum sVEGFR1 and sVEGFR2 levels between children and adults. To demonstrate the usefulness of the reference value for children, we measured serum sVEGFR1 and sVEGFR2 levels in children with diarrhea positive (D+) hemolytic uremic syndrome (HUS) as a preliminary study. Serum sVEGFR2 levels in children with HUS were markedly higher than those in healthy children from the onset of D + HUS. The reference value for healthy children in the present study will allow normal and pathological conditions to be discriminated from each other in future study.

Selective cesium removal from radioactive liquid waste by crown ether immobilized new class conjugate adsorbent.

Conjugate materials can provide chemical functionality, enabling an assembly of the ligand complexation ability to metal ions that are important for applications, such as separation and removal devices. In this study, we developed ligand immobilized conjugate adsorbent for selective cesium (Cs) removal from wastewater. The adsorbent was synthesized by direct immobilization of dibenzo-24-crown-8 ether onto inorganic mesoporous silica. The effective parameters such as solution pH, contact time, initial Cs concentration and ionic strength of Na and K ion concentrations were evaluated and optimized systematically. This adsorbent was exhibited the high surface area-to-volume ratios and uniformly shaped pores in case cavities, and its active sites kept open functionality to taking up Cs. The obtained results revealed that adsorbent had higher selectivity toward Cs even in the presence of a high concentration of Na and K and this is probably due to the Cs-π interaction of the benzene ring. The proposed adsorbent was successfully applied for radioactive Cs removal to be used as the potential candidate in Fukushima nuclear wastewater treatment. The adsorbed Cs was eluted with suitable eluent and simultaneously regenerated into the initial form for the next removal operation after rinsing with water. The adsorbent retained functionality despite several cycles during sorption-elution-regeneration operations.

Detection of Anaplasma phagocytophilum and Anaplasma bovis in small wild mammals from Taichung and Kinmen Island, Taiwan.

A total of 138 animals from 7 species (Apodemus agrarius, Bandicota indica, Crocidura suaveolens, Mus caroli, Mus formosanus, Rattus losea, and Suncus murinus) captured in Taichung, located in central Taiwan, and Kinmen Island, an island off the shore of China, were examined for the presence of Anaplasma phagocytophilum. The presence of the bacteria, which causes human granulocytic anaplasmosis, was examined by nested PCR targeting the16S rDNA. Twelve animals (8.7%) from M. caroli and R. losea, and 25 (18.1%) from A. agrarius, B. indica, M. caroli, and R. losea were infected with A. phagocytophilum and Anaplasma bovis, respectively. Phylogenetic analysis revealed that partial 16S rDNA sequences in the 12 aforementioned animals showed higher similarity to the sequences related to A. phagocytophilum detected in wild rodents (Rattus and Niviventer) from southeast China. The sequences of the other 25 animals belonged to the A. bovis clade. We demonstrated that small wild mammals were infected with A. phagocytophilum and A. bovis in Taichung and Kinmen Island, Taiwan.