We fabricated several sapphire screw threads and performed a strength test on them at the liquid nitrogen temperature of 77?K. The screw threads were subjected to and withstood a 3000?N load. To the best of our knowledge, this is the first strength test of sapphire screw threads at a cryogenic temperature. The result suggests a new way of connecting sapphire components. Although sapphire is already used in many applications, the result may provide a new way to use the material as a structural element in even more applications.
The yeast ubiquitin-like and ubiquitin-associated protein Dsk2 is one of the ubiquitin receptors that function in the ubiquitin-proteasome pathway. We screened the Dsk2-interacting proteins in Saccharomyces cerevisiae by a two-hybrid assay and identified a novel Dsk2-interacting protein, Irc22, the gene locus of which has previously been described as YEL001C, but the function of which is unknown. IRC22/YEL001C encodes 225 amino acid residues with a calculated molecular weight of 25 kDa. The Irc22 protein was detected in yeast cells. IRC22 was a nonessential gene for yeast growth, and its homologs were found among ascomycetous yeasts. Irc22 interacted with Dsk2 in yeast cells, but not with Rad23 and Ddi1. Ubiquitin-dependent degradation was impaired mildly by over-expression or disruption of IRC22. Compared with the wild-type strain, dsk2D exhibited salt sensitivity while irc22D exhibited salt tolerance at high temperatures. The salt-tolerant phenotype that was observed in irc22D disappeared in the dsk2Dirc22D double disruptant, indicating that DSK2 is positively and IRC22 is negatively involved in salt stress tolerance. IRC22 disruption did not affect any responses to DNA damage and oxidative stress when comparing the irc22D and wild-type strains. Collectively, these results suggest that Dsk2 and Irc22 are involved in salt stress tolerance in yeast.
Physicians use ultrasound scans to obtain real-time images of internal organs, because such scans are safe and inexpensive. However, people in remote areas face difficulties to be scanned due to aging society and physicians shortage. Hence, it is important to develop an autonomous robotic system to perform remote ultrasound scans. Previously, we developed a robotic system for automatic ultrasound scan focusing on humans liver. In order to make it a completely autonomous system, we present in this paper a way to autonomously localize the epigastric region as the starting position for the automatic ultrasound scan. An image processing algorithm marks the umbilicus and mammary papillae on a digital photograph of the patients abdomen. Then, we made estimation for the location of the epigastric region using the distances between these landmarks. A supporting algorithm distinguishes rib position from epigastrium using the relationship between force and displacement. We implemented these algorithms with the automatic scanning system into an apparatus: a Mitsubishi Electrics MELFA RV-1 six axis manipulator. Tests on 14 healthy male subjects showed the apparatus located the epigastric region with a success rate of 94%. The results suggest that image recognition was effective in localizing a human body part.
A 66-year-old man was admitted to our hospital on suspicion of lung cancer with bone metastasis. He suffered multiple joint and muscle pain. (18)F-Fluorodeoxy glucose positron emission tomography (FDG-PET) showed multiple accumulations in the lung, bones including the vertebrae, and mediastinal lymph nodes. Anti-human immunodeficiency virus (HIV) antibody was negative. Because Mycobacterium avium complex (MAC) was isolated from bronchial lavage fluid, bronchial wall, peripheral blood, and muscle abscess, he was diagnosed as having disseminated MAC infection. Although multidrug chemotherapy was initiated, his condition rapidly deteriorated at first. After surgical curettage of the musculoskeletal abscess, his condition gradually improved. As for etiology, we suspected that neutralizing factors against interferon-gamma (IFN-?) might be present in his serum because a whole blood IFN-? release assay detected low IFN-? level even with mitogen stimulation. By further investigation, autoantibodies to IFN-? were detected, suggesting the cause of severe MAC infection. We should consider the presence of autoantibodies to IFN-? when a patient with disseminated NTM infection does not indicate the presence of HIV infection or other immunosuppressive condition.
A 55-year-old woman was admitted to our hospital because of chest pain, fever, and right pleural effusion that was exudative and lymphocyte-dominant with a high level of adenosine deaminase (ADA). Since her blood QuantiFERON-TB 3G test (QFT) was positive, she was diagnosed with tuberculous pleurisy. After initiation of anti-tuberculosis chemotherapy with isoniazid, rifampicin, ethambutol, and pyrazinamide, her symptoms improved. Later, liquid culture of the pleural effusion turned positive for Mycobacterium tuberculosis. On the 18th day of treatment, her chest X-ray and computed tomography exhibited pleural effusion in a moderate amount in the left thorax, with subsiding pleural effusion in the right thorax. Thoracocentesis demonstrated that the left thorax effusion was also exudative and lymphocyte-dominant, with elevated QFT response and high ADA concentration, suggesting tuberculous pleurisy. Mycobacterium tuberculosis was detected in the culture of a left pleural biopsy specimen obtained by thoracoscopy. We assumed that the left pleural effusion was due to paradoxical worsening because (1) on admission no effusion or lung parenchymal lesion was detected in the left hemithorax, (2) on the 14th day of treatment she was afebrile without pleural effusion on both sides, and (3) the bacilli were sensitive to the drugs she had been taking regularly. We performed drainage of the left effusion and continued the same anti-tuberculosis drugs, which led to the elimination of all her symptoms and of the pleural effusion on both sides. In conclusion, paradoxical worsening should be included in the differential diagnosis when contralateral pleural effusion is detected during the treatment of tuberculosis.
Ubiquitin-like (UBL)-ubiquitin-associated (UBA) proteins, including Dsk2 and Rad23, act as delivery factors that target polyubiquitinated substrates to the proteasome. We report here that the Dsk2 UBL domain is ubiquitinated in yeast cells and that Dsk2 ubiquitination of the UBL domain is involved in Dsk2 stability, depending on the Dsk2 UBA domain. Also, Dsk2 lacking ubiquitin chains impaired ubiquitin-dependent protein degradation and decreased the interaction of Dsk2 with polyubiquitinated proteins in cells. Moreover, Dsk2 ubiquitination affected ability to restore the temperature-sensitive growth defect of dsk2?. These results indicate that ubiquitination in the UBL domain of Dsk2 has in vivo functions in the ubiquitin-proteasome pathway in yeast.
Since its emergence, the 2009 pandemic H1N1 virus has spread rapidly throughout the world. Previously, we reported that most individuals born after 1920 do not have cross-reactive virus-neutralizing antibodies against pandemic (H1N1) 2009 virus, indicating that they were immunologically naïve to the pandemic virus prior to its emergence. This finding provided us with an excellent opportunity for a seroepidemiological investigation of the transmission mode of the pandemic virus in the community. To gain insight into its transmission within communities, we performed a serosurvey for pandemic virus infection with schoolchildren at an elementary school in Tokyo, Japan, and their parents. We observed a high prevalence of neutralizing antibodies to the pandemic virus in the children at this school, although the percentage of children positive for the neutralizing antibodies varied among classrooms. While a much lower prevalence was observed among parents, seropositivity of the parents correlated with that of their schoolchildren. Moreover, many adults appeared to have experienced asymptomatic infection with the pandemic virus. These data suggest that the pandemic virus was readily transmitted among schoolchildren in elementary schools and that it was also transmitted from schoolchildren to their parents.
PCNA links Cdt1 and p21 for proteolysis by Cul4-DDB1-Cdt2 (CRL4(Cdt2) ) in the S phase and after DNA damage in mammalian cells. However, other PCNA-interacting proteins, such as ligase I, are not targets of CRL4(Cdt2) . In this study, we created chimera constructs composed of Cdt1 and ligase I and examined how the proteolysis of PCNA-interacting proteins is regulated. Consistent with a recent report using the Xenopus egg system (Havens & Walter 2009), two amino acid elements are also required for degradation in HeLa cells: TD amino acid residues in the PIP box and the basic amino acid at +4 downstream of the PIP box. In addition, we demonstrate that a basic amino acid at +3 is also required for degradation and that an acidic amino acid residue following the basic amino acids abolishes the degradation. Electrostatic surface images suggest that the basic amino acid at +4 is involved in a contact with PCNA, while +3 position extending to opposite direction is important to create a positively charged surface. When all these required elements were introduced in ligase I peptide, the substituted form became degraded. Our results demonstrate that PCNA-dependent degron is strictly composed to avoid illegitimate destruction of PCNA-interacting proteins.
The licensing factor Cdt1 is degraded by CRL4(Cdt2) ubiquitin ligase dependent on proliferating cell nuclear antigen (PCNA) during S phase and when DNA damage is induced in G(1) phase. Association of both Cdt2 and PCNA with chromatin was observed in S phase and after UV irradiation. Here we used a micropore UV irradiation assay to examine Cdt2 accumulation at cyclobutane pyrimidine dimer-containing DNA-damaged sites in the process of Cdt1 degradation in HeLa cells. Cdt2, present in the nucleus throughout the cell cycle, accumulated rapidly at damaged DNA sites during G(1) phase. The recruitment of Cdt2 is dependent on prior PCNA chromatin binding because Cdt2 association was prevented when PCNA was silenced. Cdt1 was also recruited to damaged sites soon after UV irradiation through its PIP-box. As Cdt1 was degraded, the Cdt2 signal at damaged sites was reduced, but PCNA, cyclobutane pyrimidine dimer, and XPA (xeroderma pigmentosum, complementation group A) signals remained at the same levels. These findings suggest that Cdt1 degradation following UV irradiation occurs rapidly at damaged sites due to PCNA chromatin loading and the recruitment of Cdt1 and CRL4(Cdt2), before DNA damage repair is completed.
Somatoform pain disorder is characterized by persistent and chronic pain at one or more sites without an associated general medical condition and in which psychological factors are thought to play a role. This study aimed to investigate the pathological features of somatoform pain disorder localized to the oral region by single photon emission computed tomography (SPECT).
We aimed to examine the association between the angiotensin I-converting enzyme (ACE) gene (insertion (I) and deletion (D)) polymorphism in Japanese university track athletes and race distance, as well as to evaluate the gender effects on this association. The ACE I/D allele frequency was determined in 277 athletes (176 men, 101 women; aged 19.7 +/- 1.2 years), who were then grouped on the basis of their major competitive race distances (short distance (SD), < or = 200 m; middle distance (MD), 400-800 m, and long distance (LD), > or =1500 m). The ACE I allele frequency increased with the distance (44.4%, 48.4%, and 66.2% for the SD (n = 107), MD (n = 62), and LD (n = 108) groups, respectively; p < 0.001, chi(2) test). On multinomial logistic regression analysis, significant associations between ACE genotype and race distance were observed only in male athletes (ID vs. SD, p = 0.004; ID vs. LD, p = 0.030; II vs. LD, p = 0.001). There was no significant association between ACE genotype and race distance in female athletes. We conclude that the ACE I allele is overrepresented in endurance athletes, and that its frequency varies depending on gender.
In a summer training camp, strenuous physical exercises are carried out to improve endurance ability. The effects of the training stress on the immune system have been studied extensively. However, less attention has been paid to non-specific immunological changes. Serum opsonic activity (SOA) is a more direct and suitable indicator of non-specific humoral immunity. In this study, we used the luminal-dependent chemiluminescence (LmCL) to measure reactive oxygen species generation from pooled human neutrophils as an indicator of SOA. We also measured plasma myeloperoxidase (MPO) and plasma cytokine levels. Twenty-two female college runners took part in this study after giving their written informed consent. There was no significant difference in the physical characteristics and serum enzyme levels. However, significant differences were observed in the changes of blood property and plasma cytokine levels. According to MPO levels, neutrophils in vivo may be deactivated during the camp. Positive correlations between fluctuations of pro- and anti-inflammatory cytokine levels were observed in this study. According to the results of peak time and peak height of LmCL, SOA seems to increase at first qualitatively and then quantitatively during the summer camp. The increased SOA level may compensate for the decrease in neutrophil activity.
This study aimed to determine the characteristics of patients with neuropathic tooth pain (NTP) who were selected from a group of patients who developed persistent pain after undergoing endodontic procedures.
The DNA replication-licensing factor Cdt1 is present during the G1 phase of the cell cycle. When cells initiate S phase or are UV-irradiated, Cdt1 is recruited to chromatin-bound PCNA and ubiquitinated by CRL4(Cdt2) for degradation. In both situations, the substrate-recognizing subunit Cdt2 is detected as a highly phosphorylated form. Here, we show that both caffeine-sensitive kinase and MAP kinases are responsible for Cdt2 phosphorylation following UV irradiation. We found that Cdt1 degradation was attenuated in the presence of caffeine. This attenuation was also observed in cells depleted of ATR, but not ATM. Following UV irradiation, Cdt2 was phosphorylated at the S/TQ sites. ATR phosphorylated Cdt2 in vitro, mostly in the C-terminal region. Cdt1 degradation was also induced by DNA damaging chemicals such as methyl methanesulfonate (MMS) or zeocin, depending on PCNA and CRL4-Cdt2, though it was less caffeine-sensitive. These findings suggest that ATR, activated after DNA damage, phosphorylates Cdt2 and promotes the rapid degradation of Cdt1 after UV irradiation in the G1 phase of the cell cycle.
Recent work identified the E3 ubiquitin ligase CRL4(Cdt2) as mediating the timely degradation of Cdt1 during DNA replication and following DNA damage. In both cases, proliferating cell nuclear antigen (PCNA) loaded on chromatin mediates the CRL4(Cdt2)-dependent proteolysis of Cdt1. Here, we demonstrate that while replication factor C subunit 1 (RFC1)-RFC is required for Cdt1 degradation after UV irradiation during the nucleotide excision repair process, another RFC complex, Ctf18-RFC, which is known to be involved in the establishment of cohesion, has a key role in Cdt1 degradation in S phase. Cdt1 segments having only the degron, a specific sequence element in target protein for ubiquitination, for CRL4(Cdt2) were stabilized during S phase in Ctf18-depleted cells. Additionally, endogenous Cdt1 was stabilized when both Skp2 and Ctf18 were depleted. Since a substantial amount of PCNA was detected on chromatin in Ctf18-depleted cells, Ctf18 is required in addition to loaded PCNA for Cdt1 degradation in S phase. Our data suggest that Ctf18 is involved in recruiting CRL4(Cdt2) to PCNA foci during S phase. Ctf18-mediated Cdt1 proteolysis occurs independent of cohesion establishment, and depletion of Ctf18 potentiates rereplication. Our findings indicate that individual RFC complexes differentially control CRL4(Cdt2)-dependent proteolysis of Cdt1 during DNA replication and repair.
To clarify changes of neutrophil functions, mental conditions and relationships among them, 19 male elite long-distance runners participated in this study for 6 months. Examinations, with informed consent, were carried out once a month. According to the results of physical characteristics, it was thought that training intensity was reduced after the main race, Hakone-Ekiden. Neutrophil functions were estimated by indices of reactive oxygen species production, determined by luminol- and lucigenin-dependent chemiluminescence (LmCL and LgCL, respectively) and cytochrome c reduction methods. The peak times (PT) in LmCL and LgCL (LgPT) were most prolonged in January and December, respectively. The peak heights (PH) in LmCL (LmPH) were enhanced in February. Decreased levels of negative categories in the profile of mood state (POMS) questionnaire and the total mood state (TMS) of POMS were observed in February without significance. Correlation analysis using measured values revealed significant negative correlation between LmPH and negative categories in POMS; however, these correlations were possibly a mere appearance, caused by personal differences. After eliminating personal differences, LgPT correlated positively to depression (p< 0.05), anger (p< 0.05), fatigue (p < 0.01) and TMS (p< 0.05). These results suggest that the mean time from the recognition of foreign matter to the maximum production of superoxide from neutrophils is prolonged in the mentally suppressed conditions found under continuous physical training.
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