Effect of an Internet-Delivered Cognitive Behavioral Therapy-Based Sleep Improvement App for Shift Workers at High Risk of Sleep Disorder: Single-Arm, Nonrandomized Trial

BACKGROUND

Shift workers are at high risk of developing sleep disorders such as shift worker sleep disorder or chronic insomnia. Cognitive behavioral therapy (CBT) is the first-line treatment for insomnia, and emerging evidence shows that internet-based CBT is highly effective with additional features such as continuous tracking and personalization. However, there are limited studies on internet-based CBT for shift workers with sleep disorders.

OBJECTIVE

This study aimed to evaluate the impact of a 4-week, physician-assisted, internet-delivered CBT program incorporating machine learning-based well-being prediction on the sleep duration of shift workers at high risk of sleep disorders. We evaluated these outcomes using an internet-delivered CBT app and fitness trackers in the intensive care unit.

METHODS

A convenience sample of 61 shift workers (mean age 32.9, SD 8.3 years) from the intensive care unit or emergency department participated in the study. Eligible participants were on a 3-shift schedule and had a Pittsburgh Sleep Quality Index score ≥5. The study comprised a 1-week baseline period, followed by a 4-week intervention period. Before the study, the participants completed questionnaires regarding the subjective evaluation of sleep, burnout syndrome, and mental health. Participants were asked to wear a commercial fitness tracker to track their daily activities, heart rate, and sleep for 5 weeks. The internet-delivered CBT program included well-being prediction, activity and sleep chart, and sleep advice. A job-based multitask and multilabel convolutional neural network-based model was used for well-being prediction. Participant-specific sleep advice was provided by sleep physicians based on daily surveys and fitness tracker data. The primary end point of this study was sleep duration. For continuous measurements (sleep duration, steps, etc), the mean baseline and week-4 intervention data were compared. The 2-tailed paired t test or Wilcoxon signed rank test was performed depending on the distribution of the data.

RESULTS

In the fourth week of intervention, the mean daily sleep duration for 7 days (6.06, SD 1.30 hours) showed a statistically significant increase compared with the baseline (5.54, SD 1.36 hours; P=.02). Subjective sleep quality, as measured by the Pittsburgh Sleep Quality Index, also showed statistically significant improvement from baseline (9.10) to after the intervention (7.84; P=.001). However, no significant improvement was found in the subjective well-being scores (all P>.05). Feature importance analysis for all 45 variables in the prediction model showed that sleep duration had the highest importance.

CONCLUSIONS

The physician-assisted internet-delivered CBT program targeting shift workers with a high risk of sleep disorders showed a statistically significant increase in sleep duration as measured by wearable sensors along with subjective sleep quality. This study shows that sleep improvement programs using an app and wearable sensors are feasible and may play an important role in preventing shift work-related sleep disorders.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.2196/24799.

Dietary Variety and Decline in Lean Mass and Physical Performance in Community-Dwelling Older Japanese: A 4-year Follow-Up Study

OBJECTIVES

To examine associations of dietary variety with changes in lean mass and physical performance during a 4-year period in an elderly Japanese population.

DESIGN

Four-year prospective study.

SETTING

The Hatoyama Cohort Study and Kusatsu Longitudinal Study, Japan.

PARTICIPANTS

935 community-dwelling Japanese aged 65 years or older.

MEASUREMENTS

Dietary variety was assessed using a 10-item food frequency questionnaire. Body composition was determined by multifrequency bioelectrical impedance analysis, and physical performance (grip strength and usual gait speed) was measured in surveys at baseline and 4 years later. Longitudinal analysis included only participants who were originally in the upper three quartiles of lean body mass, appendicular lean mass, grip strength, and usual gait speed. The outcome measures were decline in lean body mass, appendicular lean mass, grip strength, and usual gait speed, defined as a decrease to the lowest baseline quartile level at the 4-year follow-up survey. Associations of dietary variety with the outcome measures were examined by logistic regression analysis adjusted for potential confounders.

RESULTS

In the fully adjusted model, the odds ratios for decline in grip strength and usual gait speed were 0.43 (95% confidence interval, 0.19-0.99) and 0.43 (confidence interval, 0.19-0.99), respectively, for participants in the highest category of dietary variety score as compared with those in the lowest category. Dietary variety was not significantly associated with changes in lean body mass or appendicular lean mass.

CONCLUSION

Among older adults, greater dietary variety may help maintain physical performance, such as grip strength and usual gait speed, but not lean mass.

[Prospective study of cognitive decline assessed using the mini-mental state examination and the risk of incident long-term care insurance among community-dwelling older Japanese]

AIM

We examined the longitudinal association between the change in the Mini-Mental State Examination (MMSE) score per year and the incidence of a certified need for care in the long-term care insurance system among community-dwelling older Japanese subjects.

METHODS

A total of 773 adults 65 years of age or older who participated in a baseline survey (2002 to 2007) underwent MMSE reevaluation at least once until Wave-1 (2003 to 2008). The incidence of a certified need for care in the long-term care insurance system until Wave-2 (Wave-1 to 2013) was examined in all subjects.

RESULTS

During an average follow-up of 1,195 days (baseline survey to Wave-1), the change in the MMSE score per year was greater than 0 in 511 (66.1%) participants, 0 to -0.5 in 94 (12.2%) participants, -0.5 to -1 in 66 (8.5%) participants, -1 to -2 in 56 (7.2%) participants, and less than -2 in 46 (6.0%) participants. During an average follow-up of 1,802 days (Wave-1 to Wave-2), 104 participants (13.5%) were newly certified with a need for care in the long-term care insurance system. After controlling for important confounders, elders with a change in the MMSE score of 0 to -0.5, -0.5 to -1, -1 to -2 and less than -2 per year were 1.73 (95% confidence interval, 0.93-3.23), 1.94 (1.01-3.45), 1.95 (1.02-3.76) and 3.16 (1.68-5.98) times as likely to be newly certified with a need for care in the long-term care insurance system, respectively, compared those with a change in the score greater than 0.

CONCLUSIONS

The extent of change in the MMSE score per year independently predicted the incident certified need for care in the long-term care insurance system in a general population of older Japanese subjects. A decrease of greater than 0.5 points per year may be a useful cutoff value for clinically evaluating elders.

Association of Dietary Variety with Body Composition and Physical Function in Community-dwelling Elderly Japanese

OBJECTIVES

To examine the associations of dietary variety with body composition and physical function in community-dwelling elderly Japanese.

DESIGN

Cross-sectional study.

SETTING

Community-based.

PARTICIPANTS

A total of 1184 community-dwelling elderly adults aged 65 and over.

MEASUREMENTS

Dietary variety was assessed with a food frequency questionnaire (maximum, 10 points) that encompassed the 10 main food components of Japanese meals (meat, fish/shellfish, eggs, milk, soybean products, green/yellow vegetables, potatoes, fruit, seaweed, and fats/oils). Body composition was determined by multifrequency bioelectrical impedance analysis. Physical function was assessed by measuring grip strength and usual walking speed. Multiple linear regression analysis was used to examine the associations of dietary variety with body composition and physical function.

RESULTS

After adjusting for potential confounders, higher dietary variety scores were independently associated with higher lean mass (β (SE): 0.176 (0.049), p<0.001) and appendicular lean mass (β (SE): 0.114 (0.027), p<0.001) but not with body fat mass. Elders with a higher dietary variety score had greater grip strength and faster usual walking speed (β (SE): 0.204 (0.071), p=0.004, and β (SE): 0.008 (0.003), p=0.012, respectively).

CONCLUSION

Greater dietary variety was significantly associated with greater lean mass and better physical function in Japanese elders. The causal relationship warrants investigation in a prospective study.

Tri-Axial Accelerometer-Determined Daily Physical Activity and Sedentary Behavior of Suburban Community-Dwelling Older Japanese Adults

Knowledge regarding accelerometer-derived physical activity (PA) and sedentary behavior (SED) levels is scarce for Japanese older adults. The aims of this study were therefore to 1) describe levels of PA and SED in Japanese community-dwelling older adults, using tri-axial accelerometer; 2) examine the variation of PA and SED with respect to sex, age, and body mass index (BMI). Participants of this study were from the baseline survey of the Sasaguri Genkimon Study, who were 65 years or older and not certified as those requiring long-term care. PA was assessed objectively for seven consecutive days using tri-axial accelerometer. A total of 1,739 participants (median age: 72 years, men: 38.0%) with valid PA data were included. Overall, participants in the present study spent 54.5% of their waking time being sedentary and 45.5% being active, of which 5.4% was moderate-to-vigorous physical activity (MVPA). Women accumulated more minutes of light physical activity (LPA) and MVPA compared with men. In contrast, men spent more time being sedentary. Mean steps per day did not differ between sexes. Furthermore, participants with higher BMI (BMI ≥25) had lower PA levels, and longer SED compared with those with lower BMI (BMI <). PA levels were lower and SED was longer with age. The present study is the first to demonstrate that the levels of PA and SED differed by sex, age, and BMI in Japanese community-dwelling older adults. In particular, women were more active compared with men, providing unique insight into the current level of PA in older adults. Data presented in the study will enable further investigation of additional determinants of PA and SED in order to develop effective population-based intervention strategies to promote PA and reduce prolonged SED in the Japanese population and possibly other rapidly aging societies. Key pointsAccelerometer, that is capable to assess PA more precisely in large scale epidemiological studies, provides opportunity for improving understanding of daily PA in older adults.This study first demonstrated that the levels of PA and SED differed by sex, age, and BMI in Japanese community-dwelling older people.Women were more active compared with men, in terms of more minutes of MVPA.

[Cross-sectional and longitudinal associations of physical performance and skeletal muscle mass with cognition and cognitive decline among community-dwelling older Japanese]

AIM

This study had two objectives: to confirm the cross-sectional associations between the physical performance scale (PPS), skeletal muscle mass (SMM) and sarcopenia and cognition, and to examine whether PPS, SMM and sarcopenia are independent risk markers of cognitive decline (CD).

METHODS

Among 805 adults 65 years of age or older who participated in a baseline survey (2008-2011), 649 were reevaluated for their level of cognition at least once until 2012, and PPS, SMM, sarcopenia and cognition were assessed. CD was defined as a decrease of at least 0.5 points per year on the MMSE.

RESULTS

After controlling for sex, age and years of education, PPS, SMM and sarcopenia were associated with cognition, respectively. During a median follow-up of 3.0 years, 201 adults (31.0%) had CD. After controlling for important confounders, PPS showed a significant association with CD [OR=0.75 (95%CI: 0.65-0.87)], whereas SMM showed no significant association with CD. As compared with the people who had normal PPS and SMM, people who had low PPS and normal SMM had 2.10 times higher risk for CD.

CONCLUSIONS

We confirmed the cross-sectional associations between physical performance, SMM and sarcopenia and cognition in a general population of older adults. Although people had normal SMM, low physical performance was found to be a risk marker for subsequent CD.

The Yabu cohort study: design and profile of participants at baseline

BACKGROUND

Further evidence into the effects of social relationships on health (including those at both the individual and community levels) is needed in Japan. The Yabu Cohort Study was launched in 2012 to identify the associations between social relationships and health among community-dwelling older Japanese people and to evaluate population approaches for preventive long-term care in the community. This report describes the study design and the profile of the participants at baseline.

METHODS

The Yabu Cohort Study is a prospective study of community-dwelling individuals aged 65 years and older in Yabu, Hyogo Prefecture, Japan. The baseline survey, using a mailed self-administered questionnaire, was conducted from July through August 2012. It included information on socioeconomic status, general and psychological health, and social relationships (social network, social support, and social capital). Survival time, long-term care insurance certification, and medical and long-term care costs after the baseline survey will be followed.

RESULTS

Of 7271 questionnaires distributed, a total of 6652 were returned (91.5% response rate), and 6241 were included in the analysis. Mean age was 71.9 ± 5.2 years, 43.2% were men, and 83.8% had lived in their neighborhood for more than 40 years. Approximately 45.2% expressed general trust. About 82.4%, 49.9%, and 55.5% have participated in neighborhood association activities, municipal seminars for preventive long-term care, and salon activities in the community, respectively.

CONCLUSIONS

The study is expected to provide valuable evidence on the effects of social relationships on health and to suggest the usefulness of population approaches for preventive long-term care in Japanese communities.

Physical Fitness Measures as Potential Markers of Low Cognitive Function in Japanese Community-Dwelling Older Adults without Apparent Cognitive Problems

Detecting signs of cognitive impairment as early as possible is one of the most urgent challenges in preventive care of dementia. It has still been unclear whether physical fitness measures can serve as markers of low cognitive function, a sign of cognitive impairment, in older people free from dementia. The aim of the present study was to examine an association between each of five physical fitness measures and global cognition in Japanese community-dwelling older adults without apparent cognitive problems. The baseline research of the Sasaguri Genkimon Study was conducted from May to August 2011 in Sasaguri town, Fukuoka, Japan. Of the 2,629 baseline subjects who were aged 65 years or older and not certified as individuals requiring nursing care by the town, 1,552 participants without apparent cognitive problems (Mini-Mental State Examination score ≥24) were involved in the present study (59.0% of the baseline subjects, median age: 72 years, men: 40.1%). Global cognitive function was measured by the Japanese version of the Montreal Cognitive Assessment. Handgrip strength, leg strength, sit-to-stand rate, gait speed, and one-leg stand time were examined as physical fitness measures. In multiple linear regression analyses, each of the five physical fitness measures was positively associated with the Montreal Cognitive Assessment score after adjusting for age and sex (p < 0.001). These associations were preserved after additional adjustment for years of formal education, body mass index, and other confounding factors (p < 0.001). The present study first demonstrated the associations between multiple aspects of physical fitness and global cognitive function in Japanese community-dwelling older people without apparent cognitive problems. These results suggest that each of the physical fitness measures has a potential as a single marker of low cognitive function in older populations free from dementia and thereby can be useful in community-based preventive care of dementia. Key pointsThere is a great need for identifying lifestyle-related markers which help detect subtle cognitive impairment in the preclinical or earlier phase of dementia.In the present study, each of the five physical fitness measures employed was linearly and positively associated with the Montreal Cognitive Assessment score in the present older adults without apparent cognitive problems, after adjusting for age, sex, education, body mass index, and other confounding factors.The results suggest the potential of each physical fitness measure as a single lifestyle-related marker of low cognitive function in the population, which can be useful in community-based preventive care of dementia.

[A 10-year community intervention for disability prevention and changes in physical, nutritional, psychological and social functions among community-dwelling older adults in Kusatsu, Gunma Prefecture, Japan]

OBJECTIVES

We reported previously that a 10-year community intervention for disability prevention successfully extended healthy life expectancy at 70 years and decreased the enrollment rate of the Long-Term Care Insurance in Kusatsu, Gunma Prefecture, Japan. In order to clarify functional factors that contributed to healthy aging, this study examined changes in physical, nutritional, psychological and social functions in older adults who participated in annual health checkups over the period.

METHODS

Data sources were participants in annual health checkups conducted from 2002 to 2012 and respondents to biannual monitoring surveys conducted from 2003 to 2011. The target population was all older adults aged 70 years and over living in Kusatsu. The average participation rate over the period was 34.7% for the annual health checkups and 95.0% for the monitoring surveys. First, we examined the representativeness of the participants in annual health checkups by comparing them with the responders to monitoring surveys in terms of their higher-level functional capacity, as measured by the Tokyo Metropolitan Institute of Gerontology Index of Competence (TMIG-IC) (Analysis 1). Second, we examined changes in the physical (4 measures), nutritional (3 measures), and psychological and social (4 measures) functions of participants in annual health checkups over the period. In this analysis, we standardized the data for each year on 11 measures to a mean of 0 and a standard deviation of 1.0 using the 2002 data as the standard, and conducted statistical tests for the slopes of the linear approximate equation (intercept=0) (Analysis 2).

RESULTS

In Analysis 1, the TMIG-IC scores for participants in the annual health checkups were significantly higher in both sexes than were those for responders to the monitoring surveys. However, there were no significant year×group interactions in the scores. The difference in scores between the two groups was small for participants in their seventies, but large for participants in their eighties or over. Analysis 2 showed that all physical functions improved significantly over the period in both sexes, and the slopes of the linear approximate equation were steeper for maximal and usual gait speeds (slope=0.050 and 0.048, respectively, in men; 0.067 and 0.060, respectively, in women) than for other measures. In women, in addition to physical function, scores on the Mini-Mental State Examination (slope=0.053), Geriatric Depression Scale (slope=0.027), and Social Roll Scale (slope=0.019) also increased significantly.

CONCLUSION

Although participants in annual health checkups were biased toward better functioning, the degree of the bias did not change significantly over the period. During the same period, physical function for both sexes, and psychological and social functions for women, improved significantly. It may be concluded that functional improvement in older adults contributed to the healthy longevity in Kusatsu.

Normative data for the montreal cognitive assessment in a Japanese community-dwelling older population

BACKGROUND

Although the Montreal Cognitive Assessment (MoCA) is acknowledged as a promising neuropsychological tool, its normative data for older populations have not been established yet. The purpose of this study was to provide normative data for the MoCA in Japanese community-dwelling older people.

METHODS

In a Japanese town, 1,977 participants aged 65 years or older (mean age 73.6 years; male 41.3%) completed MoCA tests. After descriptive and regression analyses, normative data were developed for MoCA scores in the population.

RESULTS

The mean MoCA score observed (21.8 points) was lower than that for normal controls (27.4 points) in the original validation study of the MoCA. Additionally, 82.6% of MoCA scores fell below the standard cutoff of 26 points for detecting mild cognitive impairment (MCI). The regression analysis showed that higher age and fewer years of formal education were associated with lower MoCA scores (p < 0.001). Normative data for MoCA scores were presented with respect to age and education.

CONCLUSION

This study provided normative data for the MoCA in a Japanese community-dwelling older population. This research also suggests that conventional use of the MoCA as a screening tool for MCI might be problematic in cultures different from that in which the cutoff was developed.

Small number of HTLV-1-positive cells frequently remains during complete remission after allogeneic hematopoietic stem cell transplantation that are heterogeneous in origin among cases with adult T-cell leukemia/lymphoma

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) can provide long-term remission for patients with adult T-cell leukemia/lymphoma (ATLL) caused by human retrovirus, human T-lymphocyte virus (HTLV-1). To understand how HTLV-1-positive cells including ATLL cells were suppressed by allo-HSCT, we examined HTLV-1 provirus load and residual ATLL cells in peripheral blood of transplant recipients using PCR-based tests. We found that the copy number of HTLV-1 genome, called provirus, became very small in number after allo-HSCT; however, in most cases, provirus did not disappear even among long-term survivors. Tumor-specific PCR tests demonstrated that most of HTLV-1-positive cells that remained long after transplantation were not primary ATLL cells but donor-derived HTLV-1-positive cells. We also found a case having very low amount of residual disease in peripheral blood even long after transplantation. There was only one recipient in whom we failed to show the presence of HTLV-1 genome and antibody against HTLV-1 even with an extensive search, which strongly suggested the elimination of HTLV-1 after allo-HSCT. These results demonstrated that after allo-HSCT the small amount of residual HTLV-1-positive cells were heterogeneous in origin and that long-term disease control for ATLL could be obtained without the complete elimination of HTLV-1.

Interfering mutations provide in vivo evidence that Escherichia coli SecE functions in multimeric states

SecY, SecE and SecG form a heterotrimer, which functions as a protein translocation channel in Escherichia coli. The cytosolic loop of SecE contains a segment that is conserved among different organisms. Here we show that mutational alterations in this segment not only inactivate the SecE function but confer dominant interfering properties on the altered SecE molecule. Such effects were especially evident in mutant cells in which the requirement for SecE function was increased. Overproduction of SecE, but not of SecY, alleviated the dominant negative effects. These results suggest that the inactive SecE molecule sequesters wild-type SecE. It was also found that an amino acid substitution, D112P, in the C-terminal periplasmic region intragenically suppressed the dominant interference. These results are consistent with a notion that there is significant SecE-SecE interaction in vivo, in which the C-terminal region has an important role. The data hence suggest that dimeric SecE participates in the formation of the functional translocation channel.

Length recognition at the N-terminal tail for the initiation of FtsH-mediated proteolysis

FtsH-mediated proteolysis against membrane proteins is processive, and presumably involves dislocation of the substrate into the cytosol where the enzymatic domains of FtsH reside. To study how such a mode of proteolysis is initiated, we manipulated N-terminal cytosolic tails of three membrane proteins. YccA, a natural substrate of FtsH was found to require the N-terminal tail of 20 amino acid residues or longer to be degraded by FtsH in vivo. Three unrelated sequences of this segment conferred the FtsH sensitivity to YccA. An artificially constructed TM9-PhoA protein, derived from SecY, as well as the SecE protein, were sensitized to FtsH by addition of extra amino acid sequences to their N-terminal cytosolic tails. Thus, FtsH recognizes a cytosolic region of sufficient length (approximately 20 amino acids) to initiate the processive proteolysis against membrane proteins. Such a region is typically at the N-terminus and can be diverse in amino acid sequences.

Holding characteristics of planar objects suspended by near-field acoustic levitation

The authors have found the acoustic levitation phenomenon where planar objects of 10 kg weight can be levitated near a vibration surface. This phenomenon has been studied for non-contact transportation. A circular planar object can be suspended without contacting a circular vibration plate. We have studied the holding force which acts horizontally on the levitated objects. The horizontal position of the object is stabilized by this force. In this paper, we discuss the effect of the radius of a levitated object, levitation distance, displacement amplitude of the vibration plate and the vibration mode on the suspending force.

Conservation of histone binding and transcriptional repressor functions in a Schizosaccharomyces pombe Tup1p homolog

The Ssn6p-Tup1p corepressor complex is important to the regulation of several diverse genes in Saccharomyces cerevisiae and serves as a model for corepressor functions. To investigate the evolutionary conservation of these functions, sequences homologous to the S. cerevisiae TUP1 gene were cloned from Kluyveromyces lactis (TUP1) and Schizosaccharomyces pombe (tup11(+)). Interestingly, while the K. lactis TUP1 gene complemented an S. cerevisiae tup1 null mutation, the S. pombe tup11(+) gene did not, even when expressed under the control of the S. cerevisiae TUP1 promoter. However, an S. pombe Tup11p-LexA fusion protein repressed transcription of a corresponding reporter gene, indicating that this Tup1p homolog has intrinsic repressor activity. Moreover, a chimeric protein containing the amino-terminal Ssn6p-binding domain of S. cerevisiae Tup1p and 544 amino acids from the C-terminal region of S. pombe Tup11p complemented the S. cerevisiae tup1 mutation. The failure of native S. pombe Tup11p to complement loss of Tup1p functions in S. cerevisiae corresponds to an inability to bind to S. cerevisiae Ssn6p in vitro. Disruption of tup11(+) in combination with a disruption of tup12(+), another TUP1 homolog gene in S. pombe, causes a defect in glucose repression of fbp1(+), suggesting that S. pombe Tup1p homologs function as repressors in S. pombe. Furthermore, Tup11p binds specifically to histones H3 and H4 in vitro, indicating that both the repression and histone binding functions of Tup1p-related proteins are conserved across species.

The plasmid F OmpP protease, a homologue of OmpT, as a potential obstacle to E. coli-based protein production

OmpT, an outer membrane-localized protease of Escherichia coli, cleaves a number of exogenous and endogenous proteins during their purification. SecY, an endogenous membrane protein, is a target of this artificial proteolysis in vitro. Here we report that SecY cleavage occurs even in cell extracts from ompT-disrupted cells, if they carry an F plasmid derivative. A gene, ompP, on the F plasmid was shown to be responsible for this proteolysis. These results indicate that the absence of an F-like plasmid should be checked when choosing a host strain for E. coli-based protein production.

Complete DNA sequence analysis for 16S ribosomal RNA gene of the leproma-derived, cultivable and nerve-invading mycobacterium HI-75

The complete 1493 nucleotide sequence of the 16SrRNA gene of the leproma-derived and cultivable mycobacterium HI-75 strain was analyzed to elucidate the taxonomic characteristics by direct sequencing of the polymerase chain reaction (PCR) products. The results revealed that the sequence of mycobacterium HI-75 was mostly similar to that of Mycobacterium scrofulaceum with 5 bases differences in the sequenced 1493 bases (0.35%) of the 16SrRNA gene. M. leprae differed from the strain with 47 bases (3.3%). Sasaki and Hamit reported the nerve-invasive activity of the inoculated mycobacterium HI-75 in nude mice or the 131I-treated immunocompromised Swiss mice. The results indicate that mycobacterium HI-75 could be a mutant of M. scrofulaceum possessing the ability to invade the peripheral nerve in addition to developing leproma-like lesions.

Syd, a SecY-interacting protein, excludes SecA from the SecYE complex with an altered SecY24 subunit

Syd is an Escherichia coli cytosolic protein that interacts with SecY. Overproduction of this protein causes a number of protein translocation-related phenotypes, including the strong toxicity against the secY24 mutant cells. Previously, this mutation was shown to impair the interaction between SecY and SecE, the two fundamental subunits of the membrane-embedded part of protein translocase. We have now studied in vitro the mechanisms of the Syd-directed inhibition of protein translocation. Pro-OmpA translocation into inverted membrane vesicles (IMVs) prepared from the secY24 mutant cells as well as the accompanied translocation ATPase activity of SecA were rapidly inhibited by purified Syd protein. In the course of protein translocation, high affinity binding of preprotein-bearing SecA to the translocase on the IMV is followed by ATP-driven insertion of the 30-kDa SecA segment into the membrane. Our experiments using 125I-labeled SecA and the secY24 mutant IMV showed that Syd abolished both the high affinity SecA binding and the SecA insertion. Syd was even able to release the inserted form of SecA that had been stabilized by a nonhydrolyzable ATP analog. Syd affected markedly the proteolytic digestion pattern of the IMV-integrated SecY24 protein, suggesting that Syd exerts its inhibitory effect by interacting directly with the SecY24 protein. In accordance with this notion, a SecY24 variant with a second site mutation (secY249) resisted the Syd action both in vivo and in vitro. Thus, Syd acts against the SecY24 form of translocase, in which SecY-SecE interaction has been compromised, to exclude the SecA motor protein from the SecYE channel complex.

Genetic analysis of an essential cytoplasmic domain of Escherichia coli SecY based on resistance to Syd, a SecY-interacting protein

We previously described a dominant negative secY-d1 allele in Escherichia coli, whose product interferes with protein export, presumably by sequestering SecE, the stabilizing partner of SecY. Syd is the product of a multicopy suppressor of the secY-d1 phenotype, and its overproduction preferentially stabilizes the wild-type SecY protein. In contrast, overproduction of Syd is toxic to the secY24 mutant, which shows a partial defect in SecY-SecE interaction. We isolated Syd-resistant revertants from the secY24 mutant. Pseudo-reversions mapped to sites at or near the secY24 mutation site (Gly240-->Asp). The secY249 mutation (Ala249-->Val) intragenically suppressed Syd sensitivity, but not the temperature-sensitive Sec phenotype of the secY24 mutation. The SecY249 mutant protein shows a reduced capacity to be stabilized by Syd, suggesting that the mutation weakens the SecY-Syd interaction. The other two mutations changed residue 240 (the site of the secY24 alteration) to Asn (secY245) or Ala (secY241) and restored the ability of the cell to export protein. Although the secY245 mutant retained some sensitivity to Syd overproduction, the secY241 mutant was completely Syd-resistant. Furthermore, the secY241 mutation seemed to represent a "hyper reversion" with respect to the SecY-SecE interaction. Protein export in this mutant was no longer sensitive to SecY-d1. When the secY-d1 mutation was combined intragenically with secY241, the resulting double mutant gene (secY-d1-241) showed an increased ability to interfere with protein export. On the basis of our model for SecY-d1, these results suggest that the secY241 alteration enhances SecY-SecE interaction. These results indicate that residue 240 of SecY is crucial for the interaction between the cytosolic domains of SecY and SecE required for the establishment of the translocase complex.

[A case of ovarian cyst presenting as urinary retention]

A 54-year-old woman presented with repeated episodes of urinary retention during an approximately 7-month period of dysuria. Computerized tomography scan revealed a right ovarian cyst and a small uterine myoma. At operation, the ovarian cyst was deeply incarcerated into the pouch of Douglas displacing the bladder neck and the uterine cervix in the anterocephalad direction. Histological diagnosis of the resected cyst was benign mucinous cystadenoma. This is the 5th reported case of urinary retention caused by ovarian cyst in the Japanese literature.

A genomic study on the cultivable and nerve invading Mycobacterium HI-75 after the recovery 3 months of the inoculation to nude mice

The sequence of the polymerase chain reaction (PCR) product of 16S ribosomal RNA (16S rRNA) of the leproma-derived and cultivable Mycobacterium HI-75 (M. HI-75) which was obtained from the infected regions of inoculated mice, was examined and compared with that of the cultured bacteria by the direct sequencing techniques. The sequence was completely consistent with the cultured bacilli in the comparable 837 bases of 16S rRNA. The mycobacterium examined in this study was originally isolated as M. leprae (ML) by Skinsnes, et al. in 1975 from leproma of a lepromatous type Hansen's disease patient and therefore named as Mycobacterium leprae HI-75 by them, and was maintained from 1984 using either Ogawa's or Sauton's media in the beginning and Ogawa's medium enriched with glucronic acid and N-acetyl-D-glucosamine recently. Sasaki and Hamit reported the nerve invasion and the growth of the inoculated bacilli either to the nude mice or the I131 treated immunocompromised Swiss mice. We previously reported that cultured HI-75 was most similar to M. scrofulaceum by the direct sequencing of the gene of 16S rRNA. The 16S rRNA obtained from the mouse tissue in the present study indicated that M. HI-75 would be a variant of M. scrofulaceum possessing an ability to invade into peripheral nerve. The results suggest that the HI-75 strain claims a nature as a pathogen to develop a leproma-like lesion.

[Hansen's disease and nephropathy as its sequence]

Nephropathy as the sequences of Hansen's disease before and after the introduction of chemotherapy was compared referring to the report by Hayashi in 1943 and the summary of the autopsy reports from 1978 to 1981 at National Hansen's disease hospital Zenseien. Unlike the high rates of tuberculosis as the cause of death before the introduction of chemotherapy (41.3%) those thereafter decreased to be negligible. On the other hand the comparison of the rates of nephropathy with the same way as that of tuberculosis was impossible since the description about nephropathy by Hayashi was not sufficient to characterize each nephropathy since he included arteriolitis, glomerulonephritis and interstitial nephritis together in the term of nephritis. Death rate due to nephritis among Hansen's disease patients according to Hayashi at that time was 21.2% which was twice as many comparing to that in the other cases. According to the report about the cases of Zenseien those reported to have glomerulonephritis was 37.3% though those were not necessarily listed as the cause of death. Also the nephropathy including fibrinoid angitis with occasional microaneurysmal dilatation of afferent arteries, glomerulitis, sclerosis and stricture of efferent arteries likewise ischemic acute tubular necrosis possibly as the result of these angiopathy seemed to be present. These vascular changes partially resemble to that of microscopic periarteritis nodosa but seems to be common in the smaller arteries. In conclusion, unlike the case of tuberculosis the rate of nephritis including glomerulitis, arteriolitis and interstitial nephritis as Hayashi used as his criteria does not seem to have decreased. Therefore, the critical analysis of the nephropathy especially of that relating to the arteriolitis should be done to obtain the knowledge to suppress its occurrence.

Somatic embryogenesis ofCyclamen persicum Mill. 'Anneke' from aseptic seedlings

InCyclamen persicum 'Anneke', explants from the various vegetative organs of aseptic seedling formed embryoids. The optimal responses were recorded in Murashige and Skoog (MS) medium enriched with 5.0µM 2,4-dichlorophenoxyacetic acid (2,4-D), 0.5µM kinetin and 3-6% sucrose. Embryogenesis was enhanced at higher temperature of 25-30°C. On the other hand, light inhibited embryogenesis. Histological and morphological studies confirmed that the embryoids were indeed somatic embryos.

On the beta-glucuronidase binding protein (BGBP) of microorganisms. Its purification, the antiserum preparation against that and its localization in leproma and the other infectious lesions shown by immunohistologic method

Our previous studies suggested that M. leprae (ML) grow in peripheral nerves and lepra cells because ML metabolize hyaluronic acid (HA), and use its component for their growth by the aid of host enzyme combined to the bacilli derived beta-glucuronidase binding protein (BGBP). In this study, therefore, we examined the method to purify BGBP from a mycobacterium HI-75 originally separated from a leproma and cultured by modified Ogawa's medium containing split products of HA (glucuronic acid and N-acetylglucosamine). The distribution of BGBP in leproma and the other lesions consisting of hepatitis B virus infected liver and M. avium-intracellulare infected lung tissue were also immunohistologically examined. As the result, the best method to get BGBP was preparatory electrophoresis in the final step of the purification and not the molecular sieving. The BGBP was actually proven in leproma and the other infected tissues as described, indicating the abilities of these microorganisms to utilize the metabolic machinery of the host with the similar ways to that of ML.

Hepatic encephalopathy with increased cerebral blood flow in SPECT and MRI abnormalities in the basal ganglia

A case of hepatic encephalopathy with increased cerebral blood flow in single-photon emission computed tomography (SPECT) and abnormalities upon magnetic resonance imaging (MRI) is reported. SPECT showed increased blood flow exceeding 70 ml/100 g/min in the cerebellum, basal ganglia and cerebral cortex, with hyperammonemia and abnormal electroencephalographic signs showing severe generalized slowing. SPECT data and MRI might reflect abnormal metabolism and neuropathological changes in hepatic encephalopathy.

A study on the impression materials using for the mannequin practice

The mannequin exercises which are practiced in clinical exercises of dental colleges are getting more important these days. It is necessary to compare the difference between the efficiency of a mannequin and a living body. When making a partial denture using the simulation model, it is very important to know what kind of impression materials you are able to use or the accuracy of those impression materials. A study on a simulation model is used for making a partial denture. Choosing some sort of impression materials and treatment positions have the possibility to exert influence on impression taking through the process from impression taking to model making. At first, to find the impression materials which are able to take the impression of simulation model's simulate mucous membrane, choose nine impression materials and examined them. Then, examine the effective relationship between the impression taking and the mannequin's head and back position. Establish a mannequin's head and back inclination from four positions. Cut the acquired four models at the same location and examine them. The following results were obtained. 1. Of the impression materials used, with the exception of Flexicon and Rapid, there was no adhesiveness observed with the artificial mucosa. In addition, in the case of Exaflex Injection, Regular and Putty, there were noninduration sections among the sections that contacted with the artificial mucosa. 2. Regarding the effect of the bodily position, changes in the impression were observed for the upper jaw in the case of the median sagittal section C and the lateral section S. This was particularly frequent on the palate in the molar region.(ABSTRACT TRUNCATED AT 250 WORDS)

[A study of linearity and reciprocity during shock applied with a hammer to human dry skull]

The authors used a human dry skull on which the cranial bone mandible had been joined with an artificial articulator disk to form a single unit. Impact acceleration corresponding to weak and strong tapping was considered a dynamic load in examining the vibration transfer characteristics of the facial cranial bone when impact was applied from the mentum section in a situation designed to be closer to reality. Flexion injection type (resonance frequency f0 = 100 to 150 Hz, produced by GC Corp.) was applied to the human dry skull as an artificial periodontal membrane at thickness of 0.3 mm. In addition, Exaflex heavy body type (f0 = 400 Hz, produced by GC Corp.) was applied as an artificial disk. This was then placed on a damper produced by spreading a rubber dam sheet with a thickness of 35 microns on a tire tube with a diameter of 35 cm and an air pressure of 35 kg/cm2. Investigations were then made concerning linearity and reciprocity to determine whether an experimental system could be achieved or not. This was then followed by modal analysis. As a result, the following matters were ascertained: (1) The resonating area differed according to the extent of the force. (2) An increase in the viscoelastic elements of the silicon was accompanied by attenuation of force. (3) Directionality of force attenuation was caused by the complexity of bone structure. (4) A tapping force of 0.3G or 1G was sufficiently attenuated by the facial cranial bone. (5) The transfer function at the bone seams and thinner areas of the bones was insufficient for modal analysis of the facial region and total cranial bone of the human dry skull.

[Brain metastasis from primary pericardial mesothelioma. Case report]

A 50-year-old female was admitted because of nausea, vomiting, and cerebellar ataxia. Computed tomography scan revealed an enhanced mass accompanied with a cyst in the right cerebellar hemisphere. The mass situated in the subcortical region was removed. Histologically, highly vascular tumor cells lined the cavities. Postoperative radio- and chemotherapy were administered and the clinical symptoms improved gradually. Two months later, the patient complained of dyspnea. Chest X-ray on second admission demonstrated cardiomegaly. Hemorrhagic pericardial effusion amounting to 1000 ml was aspirated by pericardial puncture. Papillary clusters of tumor cells were demonstrated in the pericardial effusion. The patient died of cardiac failure. At necropsy solid tumors were located in the heart, lung, left inguinal region, and cerebellum. Histological diagnosis was mesothelioma arising from the heart. Primary pericardial mesotheliomas are rare; approximately 106 cases have been reported. Pericardial mesothelioma frequently spreads to the adjacent pleura and mediastinum, but distant metastases are extremely rare because patients with pericardial mesothelioma tend to die early due to cardiac failure or cardiac tamponade.

[Observation with SEM on the displacement of mucosal surface in process of denture fabrication]

The process of denture fabrication entails a series of steps that begin with impression-taking. Dimensional accuracy and displacement of surface repeatability affect results in these individual steps. Although changes in individual materials have already been measured in the past, there has been almost no measurement up to now of denture fabrication up to the denture base, using the mucous membrane as the standard and then measuring changes in the displacement of surface repeatability for each step. Noticing this lack, the authors used a Scanning Electron Microscope (SEM), presently the only non-contact measuring instrument that can be used, and measured changes at the different stages including the mucous membrane, the impression materials, the plaster and the resin. A drying process is required for the mucous membrane, and such a process can cause changes in the mucous membrane which is the basis of measurement. For this reason, the authors used Araldite, a product from Ciba-Geigy AG, as a replica material and made replicas for all the test materials, using the replicas for measurement. Results were as follows: 1. Araldite was used as the replica material, thus making it possible with the SEM to observe changes in the displacement of surface repeatability at the individual stages. 2. Major changes in the accuracy of surface were observed during impression-taking and in the period of moving from the impression material to the plaster. 3. During high-power observation with the SEM, the fine bumps on the surface of the plaster and resin disappeared and the surfaces became smooth. This is believed to be the result of the separating agent and heat.

Highly sensitive enzyme immunoassay of human interferon-beta 1

A highly sensitive sandwich enzyme immunoassay for human interferon-beta 1 (HuIFN-beta 1) was developed. HuIFN-beta 1-containing samples and horseradish peroxidase (HRP)-labeled mouse anti-HuIFN-beta 1 monoclonal antibody (Fab') were incubated overnight at 2-10 degrees C in the wells of a 96-well microtiter plate, onto which affinity-purified rabbit anti-HuIFN-beta 1 polyclonal antibody was coated. The EIA was able to detect 0.5 IU/ml of HuIFN-beta 1, thus showing higher sensitivity than bioassay. The values obtained by the EIA closely paralleled those obtained by bioassay in the concentration which bioassay can detect. In order to detect the concentration below 0.5 IU/ml of HuIFN-beta 1, the avidin/biotin-amplified EIA was also developed. The use of biotinylated mouse anti-HuIFN-beta 1 monoclonal antibody (F(ab')2) and HRP-avidin in the EIA made it possible to detect 0.1 IU/ml of HuIFN-beta 1. These EIAs were applied for the studies such as process control of HuIFN-beta 1 production, pharmacokinetics of HuIFN-beta 1, and determination of serum level of HuIFN-beta 1 in healthy subjects.