The octapeptide-repeat surface protein of Entamoeba nuttalli is a novel virulence factor that promotes adherence to host cells.

Entamoeba nuttalli is genetically the closest to Entamoeba histolytica, the causative agent of human amebiasis, and its natural host is Macaca species. A unique E. nuttalli specific surface protein (PTORS) containing 42 repeats of octapeptide was identified by comparative genomic analysis of Entamoeba species. We aimed to elucidate the function of this protein. When trophozoites from various E. nuttalli strains were examined by immunofluorescence microscopy and flow cytometry using a PTORS-specific monoclonal antibody, only a limited proportion of trophozoites were stained, indicating that the protein was not commonly expressed in all E. nuttalli trophozoite. The proportion of trophozoites expressing PTORS increased after passage in hamster livers, suggesting that the protein functions in the virulence of trophozoites in the liver tissue. Single-cell analysis revealed that in the cluster including trophozoites with PTORS gene expression, genes of virulence-related proteins were also upregulated. Trophozoites of E. histolytica transfected with PTORS showed enhanced adherence and subsequent phagocytic activity towards human Jurkat cells, independent of the lectin. E. histolytica trophozoites expressing PTORS formed larger liver abscesses in hamsters. These results demonstrate that PTORS is a novel virulence factor in Entamoeba species.

Remarkable genetic variability and high antigenicity of the octapeptide-repeat region in an Entamoeba nuttalli-specific surface protein.

Entamoeba nuttalli is genetically the closest to Entamoeba histolytica, the causative agent of human amebiasis. E. nuttalli is found in Macaca species, exhibiting no symptoms while potentially virulent. Using comparative genomics of Entamoeba species, we identified a gene encoding an E. nuttalli-specific protein containing 42 repeats of an octapeptide (PTORS). In the present study, we analyzed the genes in E. nuttalli strains derived from various geographic locations and host species. Sequence analysis of genomic DNA from four strains indicated 43, 44, and 48 repeat types in addition to 42 repeats and remarkable genetic diversity in the repeat region, although all nucleotide substitutions were synonymous. In contrast, the sequences of the N-terminal side region and C-terminus were identical among the strains. Monoclonal antibodies prepared against recombinant PTORS were reactive to the repeat regions but not to the N-terminal side regions. Polyclonal antibodies did not react with the N-terminal region, demonstrating that the repeat region had higher antigenicity. Analysis using synthetic peptides revealed that the two repeats of the octapeptide functioned as epitopes. Immunofluorescence microscopy using monoclonal antibodies demonstrated the surface localization of PTORS. These results suggest that the repeat region of PTORS plays an important role in host-parasite interactions.

Efficacy of non-rigid registration technique for misregistration in 3D-CTA fusion imaging.

PURPOSE: To assess whether fusion 3D-CTA images can be corrected using non-rigid registration (NRR) for gastroenterology imaging. METHODS: This study included 55 patients before gastroenterology surgery who underwent preoperative 3D-CTA prior to gastroenterological surgery. We recorded the coordinate of measurement points on the arterial vessels (X, Y, and Z) in each portal phase, original image of the arterial phase, and arterial phase with NRR. The distance of misregistration between the two points was calculated with the coordinate of the original image with NRR and that of the portal phase as true value. RESULTS: The distance of misregistration between the two points in the original arterial and portal phase images was significantly higher than that in the arterial phase image with NRR on all directions (p < 0.01). CONCLUSIONS: This study showed that NRR may correct misregistration on fusion 3D-CTA imaging. Hence, it can visualize correctly the anatomy of the vessel.

[Development of New Digital Phantom Creation Tool for Evaluation of Low-contrast Detectability Using Iterative Reconstruction].

PURPOSE: We developed a novel digital phantom-creation tool that will help formulate the standard shooting method for a three-phase dynamic liver study. Here, we present data demonstrating the usefulness of this tool in the assessment of low-contrast detectability and visibility. METHODS: We performed a visual evaluation by adding a spherical digital phantom with a diameter of 8 mm and a computed tomography (CT) value difference of 10 Hounsfield unit (HU) to images taken using filtered back projection and seven types of adaptive iterative dose reduction 3D (Weak, Mild, eMild, Standard, eStandard, Strong, and eStrong). We also examined the partial-volume effect by drawing a profile curve using a digital phantom with a CT value difference of 30 HU and a diameter of 5 mm. Furthermore, a digital phantom with two kinds of filters (smoothing and Gaussian) was added to the image of the home-made simulated tumor phantom to visual valuate its visibility in the phantom's low-contrast module and the digital phantom. RESULTS: Detection sensitivity was significantly decreased in Standard, eStandard, Strong, and eStrong, and the area under the curve also decreased in a similar fashion. We confirmed that the partial-volume effect was due to the different maximum CT values in the profile curve at 4 and 5 mm thickness. The visibility of the low-contrast module and digital phantom was most consistent when using the Gaussian filter. CONCLUSION: This tool can be used for low-contrast detection ability evaluation.

Influences of Mental Illness Stigma on Perceptions of and Responses to Requests for Favors.

This article examines mental illness stigma effects on a request for a favor from a mentally ill individual. Four hundred and fourteen participants interacted with a hypothetical target on Facebook who was believed to have schizophrenia, depression, or a tooth cavity (i.e., the control group). Participants were asked to rate the favor request in terms of face threat, in addition to writing a response, which was then coded using message design logics. Results indicated that a request by a schizophrenic target threatened participants' positive face more significantly than that of a target with depression or without any mental illness. Participants' responses to the schizophrenic target were more likely to be conventional messages, whereas responses to the depressed target were more likely to be rhetorical messages. Theoretical and practical contributions are considered.

Optimization of the Timing of the Portal Venous Phase in Preoperative 3DCT for Malignant Liver Tumors.

Preoperative three-dimensional computed tomography (3DCT) of the liver is the most important examination in performing preoperative simulation. Detailed visualization of the portal vein using the workstation is critical to enable accurate liver segmentation. However, the timing of imaging in the portal venous phase has mostly been reported equivalent to that of the liver screening examinations commonly performed. The purpose of this study was to examine the optimal timing of image capture to create the best portal vein visualization in preoperative 3DCT of the liver. Seventy-nine patients who underwent hepatectomy for malignant liver tumors were enrolled in this study. All patients were preoperatively examined using protocol A (imaging method separated into a portal venous phase and a hepatic venous phase) and then examined 1 week after surgery using protocol B (normal liver screening protocol). We first established the regions of interest in the portal vein and the hepatic vein and then compared CT values for these regions under protocol A and protocol B. The average CT value of the portal vein in protocol A and B was 239.8±28.1 HU and 202.2±18.5 HU, respectively. The average CT value of the portal vein in protocol A was significantly higher compared with protocol B (p<0.01). By introducing separate timing for portal venous phase imaging before preoperative 3DCT (protocol A), it is possible to satisfactorily depict the portal vein.

Why do we feel close to a person who expresses gratitude? Exploring mediating roles of perceived warmth, conscientiousness, and agreeableness.

The literature suggests that expressed gratitude improves the interpersonal relationship between a beneficiary and a benefactor. However, there is little research that has explored why thanking provides these positive effects, so this study investigated thanking mechanisms to explain reasons why people feel close to a beneficiary who expresses gratitude. This study also examines the effects of apologies, which are sometimes used to show gratitude in Japan. In this experimental study, 671 Japanese participants reported their perceived closeness, warmth, conscientiousness, and agreeableness to a hypothetical beneficiary who expressed gratitude, apologies, or both after a benefit was provided. The results revealed that benefactors who received a message indicating gratitude and both gratitude and apologies reported higher levels of closeness toward a beneficiary than those who received a message with only apologies and a message without either gratitude or apologies. A structural equation model further indicated that warmth and conscientiousness mediated the link between expressed gratitude/apologies and perceived closeness.

Roles of expressed gratitude and apologies in predicting reciprocal responsiveness.

Research has indicated the critical role of responsiveness in facilitating close relationships, but what communication leads to enhanced responsiveness has not been fully explored. We hypothesized that gratitude and apologies facilitate responsiveness within friendship relationships in Japan. In Experiment 1 (n = 669), receiving gratitude, apologies, or both gratitude and apologies increased recipients' perceptions of the expresser's responsiveness more than receiving a message without either gratitude or apologies. In Experiment 2 (n = 139), the participants who received gratitude as well as receiving both gratitude and apologies (but not just apologies) wrote more responsive messages back to the expresser than those who received a message without either gratitude or apologies. Gratitude and apologies played unique roles in promoting responsiveness within friendship relationships.

Survey of Entamoeba infections in schoolchildren and macaques in Kathmandu, Nepal, and analysis of genetic polymorphisms of Entamoeba nuttalli and Entamoeba dispar isolates.

Entamoeba species infect humans and non-human primates, raising concerns associated with potential zoonotic transmission. Therefore, the prevalence of human Entamoeba infections is crucial for its management in areas, where macaques exhibit high infection rates. Previously, we demonstrated prevalent E. nuttalli infections in rhesus macaques in Kathmandu, Nepal. In this study, we surveyed Entamoeba infection among 185 schoolchildren from two schools visited by wild rhesus macaques to assess the risk of transmission. PCR-based screening for Entamoeba species identified E. coli in 13 % and E. dispar in 0.5 % of the human stool samples. However, E. nuttalli and E. chattoni infections, prevalent in macaques, were not detected in human samples. This suggests that Entamoeba spp. are not transmitted through macaques in the school environment. We surveyed the rhesus macaques living in the temple near schools as well as the rhesus and Assam macaques inhabiting Shivapri Nagarjun National Park, Kathmandu. Among the 49 macaque stool samples, E. chattoni, E. coli, E. nuttalli, and E. dispar were detected in 92 %, 86 %, 41 %, and 18 % of the samples, respectively. Notably, E. dispar infections in macaques were mostly prevalent in the temple. A sample isolated from Nagarujun showed an identical genotype at two tRNA-linked short tandem repeat loci to that of E. dispar isolated from humans, suggesting potential transmission from humans to macaques. Genotypic analysis of cultured E. nuttalli strains obtained from the macaques colonizing three locations demonstrated that the geographical distance rather than differences in macaque species played a crucial role in the genetic diversity of the parasites. The phylogenetic tree of E. nuttalli strains, including the previously isolated strains, reflected the geographical distribution of the isolation sites. This study sheds light on the intricate dynamics of Entamoeba transmission and genetic diversity in macaques and humans.

Usefulness of a new immunochromatographic assay using fluorescent silica nanoparticles for serodiagnosis of Thai patients with amebiasis.

A fluorescence immunochromatography (FIC) kit was developed recently using fluorescent silica nanoparticles coated with a recombinant C-terminal fragment of the surface lectin intermediate subunit (C-Igl) of Entamoeba histolytica to establish rapid serodiagnosis of amebiasis. We further evaluated the system using serum samples from 52 Thai patients with amebiasis. Of the patients, 50 (96%) tested positive using FIC. The samples were also tested using enzyme-linked immunosorbent assay (ELISA) with C-Igl as the antigen. Two samples were negative on ELISA but positive on FIC. The correlation coefficient between the fluorescence intensity using FIC and the optical density value using ELISA was 0.5390, indicating a moderate correlation between the two tests. Serum samples from 20 patients with malaria and 22 patients with Clostridioides difficile infection were also tested using FIC. The false-positive rates were 4/20 (20%) and 1/22 (4%) in patients with malaria and C. difficile infection, respectively. Combining the data from the present study with our previous study, the sensitivity and specificity of FIC were determined to be 98.5% and 95.2%, respectively. The results of the 50 samples were studied using a fluorescence scope and a fluorescence intensity reader, and the findings were compared. Disagreements were found in only two samples showing near-borderline fluorescence intensity, indicating that the use of scope was adequate for judging the results. These results demonstrate that FIC is a simple and rapid test for the serodiagnosis of amebiasis.

[Evaluation of Low-contrast Detectability Using the Digital Phantom Creation Tool in the Late Arterial Phase to Detect Liver Mass Lesions].

PURPOSE: Late arterial phase images of SD 8, SD 10, and SD 12 were acquired in the 3-phase dynamic study of the liver in combination with hybrid iterative reconstruction. We evaluated the low-contrast detectability by adding a simulated tumor to these images and aimed to formulate a standard image quality. METHODS: We prepared images with and without signal for 60 series of 20 samples, each with 3 image quality types (total: 120 series). The continuous confidence method by 10 observers detected 60 simulated tumors. RESULTS: The detection sensitivities were 0.765, 0.785, and 0.260 for SD 8, SD 10, and SD 12, respectively (p<0.001) with no significantly different specificities, and the areas under the curve were 0.901, 0.892, and 0.616 (p<0.001), respectively. The simulated mass detection rates were 74.5%, 75.0%, and 21.5% for SD 8, SD 10, and SD 12, respectively (p<0.001), and the intraclass correlation coefficients, which indicate interobserver reliability, were 0.697 at SD 10 without signal, and SD 12 without a signal significantly dropped to 0.185. CONCLUSION: Therefore, SD 12 images increase the possibility of overlooking lesions. Hence, image quality in the late arterial phase should be SD 10 or less.

Are one's attachment avoidance toward a particular person and his/her placement of this particular person in the attachment hierarchy inversely overlapping? Four bifactor-analysis studies.

Do one's hierarchical preference for attachment support from a particular person over other people (attachment hierarchy) and his/her discomfort with closeness and uneasiness about being dependent on that particular person (attachment avoidance) inversely overlap? These two constructs have been distinctly conceptualized. Attachment hierarchy has been regarded as a normative characteristic of attachment relationships, while attachment avoidance has been considered to reflect an individual difference of relationship quality. Employing bifactor analyses, we demonstrated a unidimensional general factor of these two concepts in four studies exploring Czech young adults' relationships with mother, father, friends, and romantic partner (Study 1); U.S. young adults' relationships with a romantic partner (Study 2); Czech adolescents' relationships with mother, father, and friends (Study 3); and Japanese young adults' relationships with mother, father, and romantic partner (Study 4). These convergent results provide the replicable and generalizable evidence that one's attachment avoidance toward a particular person and her/his placement of that particular person in the attachment hierarchy are inversely overlapping.

Nature of the liver volume depending on the gender and age assessing volumetry from a reconstruction of the computed tomography.

Although the liver is a regenerating organ, excessive loss of liver volume (LV) can cause fatal liver failure. It is unclear whether LV is correlated with age; however, it is known that liver function decreases with age. In addition, the gender-related role of LV remains unclear. This study aimed to investigate the changes in LV by age and gender. Between January and December 2018, 374 consecutive patients who underwent abdominal multidetector computed tomography (MDCT) for any abdominal examinations were enrolled. LV was evaluated using MDCT. The relationship between the LV and body mass index (BMI), body surface area (BSA), age, and gender was investigated. The modified LV (mLV) was calculated by a formula measured LV × 1.5/BSA. LV correlated to BSA more than to BMI in both the males (R: 0.559 vs. 0.416) and females (R: 0.479 vs. 0.300) in our study. Age was negatively correlated to LV and BSA, and correlated to LV more than to BSA in males (R: 0.546 vs. 0.393) and females (R: 0.506 vs. 0.385). In addition, the absolute slope between age and LV in the males was higher than that in the females (14.1 vs. 10.2, respectively). Furthermore, the absolute slope of age and mLV in the males was slightly higher than in the females (9.1 vs. 7.3, respectively). In conclusion, LV in the normal liver is correlated to age rather than the one in the diseased liver. Liver volume in the males decreased more with age than LV in the females.

Evaluation of computed tomography arterial portography scan timing using different bolus tracking methods.

Computed tomography arterial portography (CTAP) is widely used with a fixed scan timing and contrast medium quantity; however, these parameters are not necessarily optimal. In this study, CTAP scan timing was analyzed by different bolus tracking methods to monitor the inflow of the contrast medium in real-time. A total of 249 patients who underwent CTAP were assessed. In 30 patients, the CTAP scanning began 33 s after contrast medium injection started (fixed method). In 74 patients, the regions of interest (ROIs) were established at two places in the inferior vena cava above the hepatic vein (inferior vena cava-ROI method). In 145 patients, the ROI was established at two places in the liver parenchyma (liver parenchyma-ROI method). Scan timing was considered appropriate when the difference in the CT value between the hepatic and portal veins approached 0; this was observed significantly more with the liver parenchyma-ROI method than with the other methods. CTAP scan timing with the liver parenchyma-ROI method was better than that with the fixed and inferior vena cava-ROI methods.

Flavan 3-ol delays the progression of disuse atrophy induced by hindlimb suspension in mice.

Periods of skeletal muscle disuse, for example due to a sedentary lifestyle or bed rest, are associated with aging and can lead to muscle atrophy. We previously found that the flavan 3-ol fraction derived from cocoa (FL) enhanced energy expenditure with metabolic changes in skeletal muscle. In the present study, we examined the effect of FL on disuse muscle atrophy induced by hindlimb suspension in mice. Male C57BL/6J mice were assigned to four groups as follows: unsuspended-vehicle, unsuspended-FL, suspended-vehicle, and suspended-FL. Mice in the vehicle treatment groups were administered distilled water and those in the FL treatment groups were dosed with FL (50mg/kg/day) for 2weeks. The weights of the gastrocnemius (GC), tibialis anterior (TA), and soleus (SOL), but not the extensor digitorum longus (EDL), decreased significantly in mice with hindlimb suspension (-11.8%, -16.5%, and -41.0%, respectively). This reduction in GC, TA, and SOL mass was inhibited by FL (-5.3%, +2.0%, and -16.6%, respectively). The FL increased the EDL weight >20% with or without hindlimb suspension. The protein level of the ubiquitin ligase, muscle ring finger-1, in the SOL was significantly increased by hindlimb suspension, but inhibited by treatment with FL. Protein expression of p70S6 kinase in the SOL was significantly decreased by hindlimb suspension, and FL treatment inhibited this change. These results suggested that FL delayed disuse muscle atrophy by metabolic alteration.

Nosocomial Serratia marcescens outbreak in Osaka, Japan, from 1999 to 2000.

OBJECTIVES: To investigate and control an outbreak of bloodstream infections (BSIs) caused by Serratia marcescens and to identify risk factors for respiratory colonization or infection with S. marcescens. DESIGN: Epidemiologic investigation, including review of medical and laboratory records, procedural investigations, pulsed-field gel electrophoresis (PFGE) typing of environmental and patient isolates, statistical study, and recommendation of control measures. PATIENTS AND SETTING: All patients admitted to a 380-bed, secondary-care hospital in Osaka Prefecture, Japan, from July 1999 through June 2000 (study period). RESULTS: Seventy-one patients were colonized or infected with S. marcescens; 3 patients who developed primary BSIs on the same ward within 5 days in June 2000 had isolates with indistinguishable PFGE patterns and indwelling intravenous catheters for more than 5 days. On multivariate analysis, among 36 case-patients with positive sputum specimens and 95 control-patients, being bedridden (odds ratio [OR], 15.91; 95% confidence interval [CI95], 4.17-60.77), receiving mechanical ventilation (OR, 7.86; CI95, 2.27-27.16), being older than 80 years (OR, 3.12; CI95, 1.05-9.27), and receiving oral cleaning care (OR, 3.10; CI95, 1-9.58) were significant risk factors. S. marcescens was isolated from the fluid tanks of three nebulizers and a liquid soap dispenser. The hospital did not have written infection control standards, and many infection control practices were found to be inadequate (eg, respiratory equipment was used without disinfection between patients). CONCLUSIONS: Poor hospital hygiene and the lack of standard infection control measures contributed to infections hospital-wide. Recommendations to the hospital included adoption of written infection control policies.