Emotion regulation processes and middle-aged Japanese women's health.

OBJECTIVES: Emotion regulation processes, such as mindfulness, self-compassion, and acceptance, have been discussed as modifiable psychological factors related to middle-aged women's psychological distress and adjustment. Although these emotion regulation factors have been discussed separately, the question remains of which factors reflect the most variance in middle-aged women's health. Therefore, this study aimed to reveal the most relevant explanatory variable for middle-aged women's health: mindfulness, self-compassion, or acceptance. METHOD: A total of 200 middle-aged women completed self-reported measures of depressive symptoms, menopausal symptoms, physical quality of life, mental quality of life, and well-being. RESULTS: Correlation analysis showed that mindfulness, self-compassion, and acceptance were significantly associated with all variables of psychological distress and adjustment. Hierarchical multiple regression analysis revealed that acceptance significantly explained the most variance of depressive symptoms, menopausal symptoms, and mental quality of life. On the other hand, self-compassion significantly explained the greatest variance in well-being. CONCLUSIONS: These findings suggest that, for middle-aged women, 'acceptance' is an important explanatory variable of psychological distress and 'self-compassion' is an important variable of psychological adjustment.

Successful treatment of cytomegalovirus enteritis after unrelated allogeneic stem cell transplantation by the infusion of ex vivo-expanded CD4+ lymphocytes derived from the recipient's peripheral blood donor cells.

Adoptive immunotherapies have been developed for antiviral agent-refractory cytomegalovirus (CMV) disease after stem cell transplantation (SCT). However, the application of such strategies is limited, particularly in terms of need for donor cooperation regarding blood sampling and inaccessibility in the setting of cord blood transplantation. Herein, we describe the first successful treatment of antiviral agent-refractory CMV enteritis after allogeneic SCT by the infusion of ex vivo-expanded donor-derived CD4(+) lymphocytes obtained from the recipient's peripheral blood.

Risk factors of recurrent sickness absence due to depression: a two-year cohort study among Japanese employees.

PURPOSE: Depression has a high recurrence rate among employees. There have been few studies investigating risk factors for recurrent sickness absence due to depression after return to work (RTW). The objective of this study was to identify potential risk factors. METHODS: Subjects were 540 full-time employees at the biggest telecommunication company in Japan who returned to work from April 2002 to March 2008 after their first leave of absence due to depression. The Cox proportional hazard model was employed to find risk factors for recurrent sickness absence by analyzing variables including demographic, work-related and work environmental factors. RESULTS: Of 540 study subjects, 200 employees (37.0 %) experienced recurrent sickness absence due to depression after RTW within the follow-up period. Higher organizational job demand evaluated by the Brief Job Stress Questionnaire (BJSQ) was found to be a risk factor (OR 1.46, 95 % CI 1.01-2.10) for recurrent sickness absence due to depression adjusted for confounding factors. CONCLUSIONS: High organizational job demand (evaluated by BJSQ) is a risk factor for recurrent sickness absence due to depression after RTW.

Heavy overtime work and depressive disorder among male workers.

BACKGROUND: The association between overtime and depression is unclear and very few studies have examined the association between heavy overtime work, i.e. working more than 60 h per week, and depression. AIMS: To examine the association between heavy overtime work and the onset of depressive disorder among male workers. METHODS: A 1-year follow-up cohort study of male workers in a manufacturing company in Japan, between 2008 and 2009. Working hours, depressive disorder, assessed by the Center for Epidemiologic Studies Depression (CES-D) Scale (score ≥16 points), and covariates were measured at baseline and at follow-up. Participants who had depressive disorder at baseline were excluded. RESULTS: At follow-up, 1194 participants aged between 18 and 71 years were analysed. Multiple logistic regression analysis revealed that the odds ratio for the new onset of depressive disorder was 4.5 (95% CI 1.8-11.1) times higher for employees working >60 h per week than for those working ≤50 h per week, when adjusted for age, lifestyle factors, work-related characteristics and socio-demographic characteristics at baseline and working hours at follow-up. However, the correlation between working 50.1 to 60 h per week and depressive disorder was not significant. The trend test of depressive disorder among groups by working hours was significant (P < 0.01). CONCLUSIONS: Heavy overtime work is a risk factor for the new onset of depressive disorder in this population of male workers. Working >60 h per week may be the cut-off to screen for high-risk groups who need preventive action against depressive disorder.

Exciton diffusion in near-infrared absorbing solution-processed organic thin films.

We report on singlet-singlet annihilation and exciton diffusion in as-prepared p-type and annealed n-type thin films of the low-bandgap quinoidal quaterthiophene [QQT(CN)4] using ultrafast transient absorption measurements. The decay dynamics of exciton populations are well described by a one-dimensional diffusion-limited bimolecular recombination, indicating that the singlet excitons migrate preferentially along the stacking direction. Our results show that the exciton diffusion constants in QQT(CN)4 films do not vary significantly upon thermal annealing. Exciton diffusion lengths are measured to be as high as 4 and 5 nm in as-prepared and annealed QQT(CN)4 films, respectively. We also observe an influence of the excitation densities on the singlet exciton diffusion, which is attributed to phonon scattering. Because of the possibility of patterning p-n regions in QQT(CN)4 films by thermal nanolithography techniques, this study provides important insight not only into the photophysical properties of quinoidal oligothiophene derivatives but also for their future integration into high-performance p-n nanostructured near infrared light-sensing devices.

Long-term stable obesity increases risk of hypertension.

OBJECTIVES: Although some prospective cohort studies have shown that baseline BMI is positively associated with a future incident risk for hypertension, these studies do not account for weight changes during the observation period. Therefore, it is not evident whether future incident risk for hypertension in obese, non-hypertensive people increases when their weight remains stable. We examined the association between long-term weight stability and risk for developing hypertension. METHODS: A total of 5201 Japanese male workers aged 30-59 years underwent health checkups in 2002 and were followed through 2006. To consider transitions in covariates during the follow-up period, we used a time-dependent covariate Cox proportional hazard model to compute the relative risks (RRs) of incident hypertension. Furthermore, as a complementary analysis, we restricted the data to individuals whose BMI remained unchanged (± 5% of baseline BMI) during the follow-up and compared the RRs between BMI categories. RESULTS: During the follow-up, there were 899 newly diagnosed cases of hypertension among the 5201 men (14,888 person-years). Mean change in BMI during the follow-up period of all subjects was 0.2 ± 1.1 kg/m(2) (range: -6.6 to 6.3 kg/m(2)). The multivariate RRs for hypertension increased as BMI increased when we applied the time-dependent covariate Cox proportional hazard model. The complementary analysis showed that the multivariate RR (confidence interval) within the ≥ 27.0 kg/m(2) BMI category was 1.43 (1.16-1.77) times higher than the reference of 23.0-24.9 kg/m(2), whereas the RR for the <21.0 kg/m(2) BMI category was 0.63 (0.51-0.79) times lower than the reference. CONCLUSIONS: A higher baseline BMI increases future incident risk for hypertension even when there has been no major weight increase. Weight management should be encouraged for obese, non-hypertensive people to prevent future hypertension.

Comparison of preoperative whole-body positron emission tomography with MDCT in patients with primary colorectal cancer.

OBJECTIVE: Preoperative use of emission tomography with(18)F-fluorodeoxyglucose (FDG-PET) in patients with primary colorectal cancer remains controversial. This study evaluated the additional value of FDG-PET in comparison with routine multidetector row computed tomography (MDCT) in patients with primary colorectal cancer. METHOD: Retrospective analysis was performed in 65 patients with colorectal cancer who underwent whole-body FDG-PET. Results of FDG-PET were compared with routine preoperative evaluation by MDCT regarding detection of primary tumour, lymph node involvement and distant metastases. All images were evaluated before surgery. RESULTS: Tumour detection rate was 100% (63/63) for MDCT and 98% (62/63) for FDG-PET. Lymph node involvement was pathologically confirmed in 35 patients. MDCT and FDG-PET displayed sensitivities of 89% (31/35; 95% CI: 73-97%) and 43% (15/35; 95% CI: 26-61%) and specificities of 52% (11/21; 95% CI: 30-74%) and 95% (20/21; 95% CI: 76-100%), respectively. Liver metastases were present in 22 patients. MDCT and FDG-PET showed accuracies of 98% (64/65; 95% CI: 92-100%) and 97% (63/65; 95% CI: 89-100%), respectively. FDG-PET detected additional extrahepatic metastatic lesions and affected treatment plan compared with MDCT in 10 patients. CONCLUSION: Preoperative FDG-PET is not superior to MDCT for detection of primary tumour, lymph node involvement or liver metastases, but may have potential clinical value in patients with advanced colorectal cancer by detecting extrahepatic distant metastases.

A cephalometric evaluation of the pharyngeal airway space in patients with mandibular retrognathia and prognathia, and normal subjects.

The antero-posterior diameter of the pharyngeal airway space (PAS) at the level of the soft palate and base of the tongue was assessed in age-matched females with a normal mandible (n=31), mandibular retrognathism (n=30) or mandibular prognathism (n=38). All subjects were examined by lateral cephalometry. Measured variables were corrected with the use of appropriate regression equations to eliminate the effects of head posture on the PAS. The corrected data showed more clear-cut differences in the PAS among the three groups than did the measured data. Pharyngeal airway diameter was largest in the group with mandibular prognathism, followed by the normal mandible and mandibular retrognathism groups. These results indicate that the antero-posterior dimension of the PAS is affected by different skeletal patterns of the mandible.

Effect of bilateral sagittal split ramus osteotomy setback on the soft palate and pharyngeal airway space.

To evaluate the effect of bilateral sagittal split ramus osteotomy setback on the morphology of the pharyngeal airway, especially the structures of the soft palate and pharyngeal airway space (PAS), lateral cephalograms obtained from 49 women before treatment and 1 year after surgery were traced and compared. All patients underwent this osteotomy to correct mandibular hyperplasia. The data were corrected with the use of regression equations for the PAS, taking into account head posture. On average, the SNB angle decreased by 3.9 degrees, resulting in an increase of 4.1 degrees in OPT/NSL (head posture, defined as the craniocervical angulation at the uppermost part of the cervical spine). The morphology of the PAS and soft palate changed significantly (p<0.01). The mean reduction in the PAS was 2.6mm retropalatinally and 4.0mm retrolingually. On average, the soft-palate length increased by 3.2mm and the soft-palate angle increased by 4 degrees. These results show that mandibular setback surgery markedly decreases the PAS and changes the morphology of the soft palate.

The effects of high glucose condition on rat tenocytes in vitro and rat Achilles tendon in vivo.

OBJECTIVES: The aim of this study was to investigate the effect of hyperglycaemia on oxidative stress markers and inflammatory and matrix gene expression within tendons of normal and diabetic rats and to give insights into the processes involved in tendinopathy. METHODS: Using tenocytes from normal Sprague-Dawley rats, cultured both in control and high glucose conditions, reactive oxygen species (ROS) production, cell proliferation, messenger RNA (mRNA) expression of NADPH oxidase (NOX) 1 and 4, interleukin-6 (IL-6), matrix metalloproteinase (MMP)-2, tissue inhibitors of matrix metalloproteinase (TIMP)-1 and -2 and type I and III collagens were determined after 48 and 72 hours in vitro. In an in vivo study, using diabetic rats and controls, NOX1 and 4 expressions in Achilles tendon were also determined. RESULTS: In tenocyte cultures grown under high glucose conditions, gene expressions of NOX1, MMP-2, TIMP-1 and -2 after 48 and 72 hours, NOX4 after 48 hours and IL-6, type III collagen and TIMP-2 after 72 hours were significantly higher than those in control cultures grown under control glucose conditions. Type I collagen expression was significantly lower after 72 hours. ROS accumulation was significantly higher after 48 hours, and cell proliferation after 48 and 72 hours was significantly lower in high glucose than in control glucose conditions. In the diabetic rat model, NOX1 expression within the Achilles tendon was also significantly increased. CONCLUSION: This study suggests that high glucose conditions upregulate the expression of mRNA for NOX1 and IL-6 and the production of ROS. Moreover, high glucose conditions induce an abnormal tendon matrix expression pattern of type I collagen and a decrease in the proliferation of rat tenocytes.Cite this article: Y. Ueda, A. Inui, Y. Mifune, R. Sakata, T. Muto, Y. Harada, F. Takase, T. Kataoka, T. Kokubu, R. Kuroda. The effects of high glucose condition on rat tenocytes in vitro and rat Achilles tendon in vivo. Bone Joint Res 2018;7:362-372. DOI: 10.1302/2046-3758.75.BJR-2017-0126.R2.

Effective prevention of thrombocytopenia in mice using adenovirus-mediated transfer of HST-1 (FGF-4) gene.

HST-1 (FGF-4) gene product is a member of the fibroblast growth factor family with a signal peptide and plays a crucial role in limb development. We showed previously that an intraperitoneal injection of replication-deficient adenovirus containing the HST-1 gene (Adex1HST-1) into normal mice caused a twofold increase in peripheral platelet count. To investigate whether Adex1HST-1 could effectively prevent experimentally induced thrombocytopenia in mice, we injected Adex1HST-1 intraperitoneally into thrombocytopenic mice induced by administration of a chemotherapeutic agent and/or by irradiation. A single Adex1HST-1 injection caused continuously increased levels of serum HST-1 protein for at least 30 d and increased the count of large megakaryocytes in bone marrow, which specifically recovered platelet counts and more efficiently diminished the extent and duration of thrombocytopenia than any other reported cytokine or any combination of cytokines so far. In the other peripheral hematological parameters, no discernible differences were detected. No other apparent side effects were observed. Therefore, this method could be useful for treatment and/or prevention of thrombocytopenia induced by chemotherapy and/or irradiation for cancer treatment.

The significance of the aberrant left hepatic artery arising from the left gastric artery at curative gastrectomy for gastric cancer.

BACKGROUND: An aberrant left hepatic artery (ALHA) is occasionally encountered during esophagogastric surgery. However, at curative gastrectomy for gastric cancer, it is questionable as to whether the ALHA need to be divided in order to maximize lymph node clearance and the issue requires clarification. METHODS: We encountered 50 patients with an ALHA during curative gastrectomy for gastric cancer between 1997 and 2001. Data concerning operative feasibility, postoperative liver function and therapeutic value of nodal dissection were analyzed retrospectively. RESULTS: For 27 patients, we preserved the ALHA, and for the remaining 23 patients, we divided the ALHA at the origin of the left gastric artery (LGA). Serum levels of aspartate aminotransferase and alanine aminotransferase were statistically significant higher on postoperative day (POD) 1 (P=0.0008 and P=0.0007), and on POD 3 (P=0.001 and P=0.008), respectively, in the ALHA-divided group. Patients who underwent a total gastrectomy predominated in the ALHA-divided group, the total number of dissected lymph nodes being higher in the ALHA-divided group (P=0.018). However, the total numbers of dissected lymph nodes and metastatic lymph nodes around the LGA were similar in the 2 groups (P=0.447 and P=0.128), respectively. No significant differences were seen between the 2 groups in morbidity and mortality. The overall 5-year survival rates were also comparable. CONCLUSIONS: Although a prospective study is required, this study suggested that routine division of the ALHA may not always be required for curative gastrectomy.

Impact of combinatorial dysfunctions of Tet2 and Ezh2 on the epigenome in the pathogenesis of myelodysplastic syndrome.

Somatic inactivating mutations in epigenetic regulators are frequently found in combination in myelodysplastic syndrome (MDS). However, the mechanisms by which combinatory mutations in epigenetic regulators promote the development of MDS remain unknown. Here we performed epigenomic profiling of hematopoietic progenitors in MDS mice hypomorphic for Tet2 following the loss of the polycomb-group gene Ezh2 (Tet2KD/KDEzh2Δ/Δ). Aberrant DNA methylation propagated in a sequential manner from a Tet2-insufficient state to advanced MDS with deletion of Ezh2. Hyper-differentially methylated regions (hyper-DMRs) in Tet2KD/KDEzh2Δ/Δ MDS hematopoietic stem/progenitor cells were largely distinct from those in each single mutant and correlated with transcriptional repression. Although Tet2 hypomorph was responsible for enhancer hypermethylation, the loss of Ezh2 induced hyper-DMRs that were enriched for CpG islands of polycomb targets. Notably, Ezh2 targets largely lost the H3K27me3 mark while acquiring a significantly higher level of DNA methylation than Ezh1 targets that retained the mark. These findings indicate that Ezh2 targets are the major targets of the epigenetic switch in MDS with Ezh2 insufficiency. Our results provide a detailed trail for the epigenetic drift in a well-defined MDS model and demonstrate that the combined dysfunction of epigenetic regulators cooperatively remodels the epigenome in the pathogenesis of MDS.

Relationship between the pharyngeal airway space and craniofacial morphology, taking into account head posture.

This study assessed the relationship between craniofacial characteristics and the size of the pharyngeal airway space (PAS), taking into account head posture. Sixty dental students 25-30 years of age (30 men and 30 women) were examined by lateral cephalometry. The data were corrected with the use of appropriate regression equations for the PAS. The PAS significantly correlated with hyoid position, maxillary and mandibular size, maxillary and mandibular prognathism, and mandibular inclination. A large, anteriorly positioned mandible was associated with a large PAS-TP (the most proximal distance between the posterior pharyngeal wall and the tongue base). Uvula length and PNS-Ba (the distance between the most posterior point of the hard palate and the most inferior point of the anterior foramen magnum) correlated with PAS-UP (the most proximal distance between the posterior pharyngeal wall and uvula). Our results suggest that the anteroposterior dimension of the PAS is substantially affected by the size of the enclosure surrounding the PAS, including the maxilla, mandible and soft palate.

Polyoncogenicity and insulinoma-inducing ability of BK Virus, a human Papovavirus, in Syrian golden hamsters.

Newborn hamsters were inoculated intracerebrally with a series of purified and concentrated BK virus samples originating from a single stock of Gardner's original strain. Most (60-100%) of the hamsters developed various tumors 3-9 months later. The frequent types of tumors were ventricular tumors (choroid plexus papillomas and ependymomas: 7-53%), malignant insulinomas (0-92%), and osteosarcomas (0-50%). The T-antigen was positive in 59 of 60 tumors tested, but the virus was rescued by the cell fusion method from only 1 of 11 cell lines derived from these tumors. The incidence of insulinomas varied greatly with the virus sample; the two samples that showed the highest incidence (47 and 92%) originated from one parental virus stock, and all the other samples with the lower incidences (0-9%) originated from another ancestral stock. These results suggest the presence of a BK virus mutant(s) differing in capacity to induce insulinoma. A functional insulinoma cell line was thus established.

Identification of genes differentially expressed in B16 murine melanoma sublines with different metastatic potentials.

B16-F10 and B16-BL6 are B16 mouse melanoma sublines that preferentially metastasize to the lung following i.v. and s.c. injections, respectively. To study molecular mechanisms underlying the different metastatic behaviors exhibited by the B16 melanoma sublines, we performed differential hybridization of the genes transcribed in these cells and compared their expression levels. We isolated four genes that were highly expressed in B16-F10 cells but not in B16-BL6 cells: TI-225 (polyubiquitin), TI-229 (pyruvate kinase), TI-241 (LRF-1 homologue), and TI-227 (novel gene). Triosephosphate isomerase, 10-formyltetrahydrofolate dehydrogenase, tyrosinase-related protein 2, cytochrome c oxidase, ATP synthetase alpha subunit, RNA helicase, and ribosomal protein (L37, J1, acidic phosphoprotein), however, showed higher expression in B16-BL6 cells than in B16-F10 cells. Among these clones, transfection of TI-241 into the low metastatic clone F1 converted the parental cells from low- into high-metastatic cells. TI-241 may regulate the expression of various genes as a transcription factor in the complex process of metastasis.

Suppressive effect of basic fibroblast growth factor on transendothelial emigration of CD4(+) T-lymphocyte.

The effect of basic fibroblast growth factor (b-FGF), one of the commonest angiogenic factors in various cancer types, on lymphocyte adhesion and transmigration across the endothelial cell monolayer was investigated using human umbilical vein-derived endothelial cells (HUVEC) and type I collagen gel. Forty-eight h exposure of HUVEC with 2 ng/ml b-FGF significantly decreased the basal adhesion of lymphocytes to endothelial cells. The decrease ratio is further enhanced by the addition of shear stress in this assay system. When HUVEC was stimulated for the last 24 h with optimal conditions of recombinant interleukin 1 beta, the percentages of transmigration as well as adhesion were also decreased significantly by the presence of b-FGF. The expression of intercellular adhesion molecule 1 and vascular cell adhesion molecule 1 was down-regulated by b-FGF exposure in both resting and activated conditions by recombinant interleukin 1 beta, supposedly the main reason for this phenomenon. The migrating cells across b-FGF-stimulated HUVEC contained a markedly lower percentage of CD4(+) T-cells than those across non-treated HUVEC, although the 4B4(+)/2H4(+) ratio in CD4(+) T-cell populations did not differ significantly. These facts suggest that the presence of b-FGF in the angiogenic area suppresses lymphocyte emigration, especially that of CD4(+) T-cells, and thus causes insufficient helper function in local immune response. This effect of b-FGF was possibly one of the critical mechanisms by which cancer cells escape from the host immune reactions in the angiogenic stage of tumor development.

Effects of platelet-rich plasma and triamcinolone acetonide on interleukin-1ß-stimulated human rotator cuff-derived cells.

OBJECTIVES: Triamcinolone acetonide (TA) is widely used for the treatment of rotator cuff injury because of its anti-inflammatory properties. However, TA can also produce deleterious effects such as tendon degeneration or rupture. These harmful effects could be prevented by the addition of platelet-rich plasma (PRP), however, the anti-inflammatory and anti-degenerative effects of the combined use of TA and PRP have not yet been made clear. The objective of this study was to determine how the combination of TA and PRP might influence the inflammation and degeneration of the rotator cuff by examining rotator cuff-derived cells induced by interleukin (IL)-1ß. METHODS: Rotator cuff-derived cells were seeded under inflammatory stimulation conditions (with serum-free medium with 1 ng/ml IL-1ß for three hours), and then cultured in different media: serum-free (control group), serum-free + TA (0.1mg/ml) (TA group), serum-free + 10% PRP (PRP group), and serum-free + TA (0.1mg/ml) + 10% PRP (TA+PRP group). Cell morphology, cell viability, and expression of inflammatory and degenerative mediators were assessed. RESULTS: Exposure to TA significantly decreased cell viability and changed the cell morphology; these effects were prevented by the simultaneous administration of PRP. Compared with the control group, expression levels of inflammatory genes and reactive oxygen species production were reduced in the TA, PRP, and TA+PRP groups. PRP significantly decreased the expression levels of degenerative marker genes. CONCLUSIONS: The combination of TA plus PRP exerts anti-inflammatory and anti-degenerative effects on rotator cuff-derived cells stimulated by IL-1ß. This combination has the potential to relieve the symptoms of rotator cuff injury.Cite this article: T. Muto, T. Kokubu, Y. Mifune, A. Inui, R. Sakata, Y. Harada, F. Takase, M. Kurosaka. Effects of platelet-rich plasma and triamcinolone acetonide on interleukin-1ß-stimulated human rotator cuff-derived cells. Bone Joint Res 2016;5:602-609. DOI: 10.1302/2046-3758.512.2000582.

HST-1/FGF-4 stimulates proliferation of megakaryocyte progenitors synergistically and promotes megakaryocyte maturation.

Megakaryocyte (MK) development is dependent on the complex interaction of MK progenitors, various cytokines and stromal elements. We previously reported that an injection of replication-deficient adenovirus containing HST-1/FGF-4 cDNA (Adex1HST-1) into mice caused a twofold increase in peripheral platelet count for 30 days without any other hematological or histological abnormality. In the present study using Adex1HST-1-infected human megakaryocytic Dami cells, we demonstrated for the first time that HST-1/FGF-4 promoted MK maturation, inducing increases in DNA ploidy, cytoplasmic and membrane maturation, and platelet-like particle release. Moreover, HST-1/FGF-4 acted on megakaryocytic cells to induce secretion of IL-6 and TNF-alpha, and increased adhesion of megakaryocytic cells to human endothelial cells primarily via VLA-4 and LFA-1 molecules; both mechanisms have been shown to lead to MK maturation. We also showed that HST-1/FGF-4 stimulates the proliferation of MK progenitors not alone but synergistically with IL-3 via IL-6 and with c-mpl ligand (thrombopoietin) not via IL-6. This result supports the hypothesis of the presence of two distinct populations of MK progenitors: IL-3-dependent and Tpo-dependent. All these results suggest that HST-1/FGF-4 can regulate MK development not only as an MK potentiating factor, but also as an inducer of cytokine secretion from MK, and as a modulator of adhesive interactions with endothelial cells.

NMR identification of the Tom20 binding segment in mitochondrial presequences.

Many mitochondrial proteins are synthesized in the cytosol as precursors with N-terminal presequences, and are imported into mitochondria with the aid of translocator protein complexes containing presequence-binding proteins. Tom20, a receptor protein which functions in an early step of the mitochondrial protein import, recognizes presequences with divergent amino acid sequences. Here, we report the identification of the segments involved in binding to Tom20 in mitochondrial presequences. We monitored the chemical shift perturbation of the NMR signals of five different 15N-labeled presequence peptides by the addition of the cytosolic receptor domain of rat or yeast Tom20. The perturbed segments occupy different positions, either near the N terminus or at the C terminus, in the presequences. Spin label experiments revealed that this is not due to different orientations of the presequence peptides bound to Tom20. The results presented here will offer a starting point to perform detailed analyses of Tom20-binding elements by systematic amino acid replacements.