102 research outputs found
High prevalence of Sulfadoxine/pyrimethamine resistance alleles in Plasmodium falciparum parasites from Bangladesh
Treatment planning for the layer-stacking irradiation system for three-dimensional conformal heavy-ion radiotherapy
We have upgraded a heavy-ion radiotherapy treatment-planning system to adapt for the layer-stacking irradiation method, which is to conform a variable spread-out Bragg peak to a target volume by means of dynamic control of the conventional beam-modifying devices. The biophysical model, the beam-setup logic, and the dose-calculation algorithm implemented for the layer-stacking method are described and the expected clinical usability is discussed. The layer-stacking method was integrated in perfect accordance with the ongoing conventional treatments so that the established protocols, which are the clinically optimized dose fractionation schemes, will still be valid. On the other hand, a simulation study indicated a substantial improvement of dose distribution with the layer-stacking method though the significance may depend on the size, shape, and location of the tumor. The completed treatment system will provide an option for improved conformal radiotherapy without interfering with the conventional method and we expect a gradual expansion of the clinical cases applicable to the layer-stacking method
Total Synthesis of Sarcophytonolide H and Isosarcophytonolide D: Structural Revision of Isosarcophytonolide D and Structure-Antifouling Activity Relationship of Sarcophytonolide H
The first total syntheses of sarcophytonolide H and the originally proposed and correct structures of isosarcophytonolide D have been achieved via transannular ring-closing metathesis (RCM). These total syntheses culminated in the stereostructural confirmation of sarcophytonolide H and the reassignment of isosarcophytonolide D, respectively. The antifouling activity of the synthetic sarcophytonolide H and its analogues was also evaluated
Late-stage divergent synthesis and antifouling activity of geraniol-butenolide hybrid molecules
Hybrid molecules consisting of geraniol and butenolide were designed and synthesized by the late-stage divergent strategy. In the synthetic route, ring-closing metathesis was utilized for the construction of a butenolide moiety. A biological evaluation of the eight synthetic hybrid compounds revealed that these molecules exhibit antifouling activity against the cypris larvae of the barnacle Balanus (Amphibalanus) amphitrite with EC50 values of 0.30-1.31 μg mL-1. These results show that hybridization of the geraniol and butenolide structural motifs resulted in the enhancement of the antifouling activity
Associations in tumor infiltrating lymphocytes between clinicopathological factors and clinical outcomes in estrogen receptor-positive/human epidermal growth factor receptor type 2 negative breast cancer
The value of assessing tumor infiltrating lymphocytes (TILs) in estrogen receptor (ER) positive/human epidermal growth factor receptor type 2 (HER2) negative breast cancer has yet to be determined. In the present study, a total of 184 cases with early distant recurrence detected within 5 years following the primary operation, 134 with late distant recurrence diagnosed following 5 years or longer and 321 controls without recurrence for >10 years following starting the initial treatment for ER-positive/HER2 negative breast cancer, registered in 9 institutions, were analyzed. The distributions of TILs and their clinical relevance were investigated. TIL distributions did not differ significantly among the early, late and no recurrence groups, employing a 30% cut-off point as a dichotomous variable. In those who had received adjuvant chemotherapy as well as endocrine therapy, a trend toward higher TIL proportions was detected when the early recurrence group was compared with the no recurrence group employing the 30% cut-off point (P=0.064). The TIL distributions were significantly associated with nodal metastasis (P=0.004), ER status (P=0.045), progesterone receptor (PgR) status (P=0.002), tumor grade (P=0.021), and the Ki67 labeling index (LI) (P=0.002) in the no recurrence group and with the Ki67 LI in the recurrence groups (P=0.002 in early recurrence group, P=0.023 in late recurrence group). High TIL distributions also predicted shorter survival time following the detection of recurrence (P=0.026). However, these prognostic interactions were not significant in multivariate analysis (P=0.200). The present retrospective study demonstrated no significant interaction between TIL proportions and the timing of recurrence. However, higher TIL proportions were observed in breast cancer patients with aggressive biological phenotypes, which tended to be more responsive to chemotherapy. The clinical relevance of stromal TILs for identifying patients who would likely benefit from additional therapies merits further investigation in a larger patient population
Unified Total Synthesis, Stereostructural Elucidation, and Biological Evaluation of Sarcophytonolides
Sarcophytonolides are cembranolide diterpenes isolated from the soft corals of genus Sarcophyton. Unified total synthesis of sarcophytonolides C, E, F, G, H, and J and isosarcophytonolide D was achieved. The synthetic routes feature NaHMDS- or SmI2-mediated fragment coupling, alkoxycarbonylallylation, macrolactonization, and transannular ring-closing metathesis. These total syntheses led to the absolute configurational confirmation of sarcophytonolide H, elucidation of sarcophytonolides C, E, F, and G, and revision of sarcophytonolide J and isosarcophytonolide D. We also evaluated the antifouling activity and toxicity of the synthetic sarcophytonolides H and J and their analogues as well as the cytotoxicity of the synthetic sarcophytonolides and the key synthetic intermediates
Exome sequencing of senescence-accelerated mice (SAM) reveals deleterious mutations in degenerative disease-causing genes
Background: Senescence-accelerated mice (SAM) are a series of mouse strains originally derived from unexpected crosses between AKR/J and unknown mice, from which phenotypically distinct senescence-prone (SAMP) and -resistant (SAMR) inbred strains were subsequently established. Although SAMP strains have been widely used for aging research focusing on their short life spans and various age-related phenotypes, such as immune dysfunction, osteoporosis, and brain atrophy, the responsible gene mutations have not yet been fully elucidated. Results: To identify mutations specific to SAMP strains, we performed whole exome sequencing of 6 SAMP and 3 SAMR strains. This analysis revealed 32,019 to 38,925 single-nucleotide variants in the coding region of each SAM strain. We detected Ogg1 p.R304W and Mbd4 p.D129N deleterious mutations in all 6 of the SAMP strains but not in the SAMR or AKR/J strains. Moreover, we extracted 31 SAMP-specific novel deleterious mutations. In all SAMP strains except SAMP8, we detected a p.R473W missense mutation in the Ldb3 gene, which has been associated with myofibrillar myopathy. In 3 SAMP strains (SAMP3, SAMP10, and SAMP11), we identified a p.R167C missense mutation in the Prx gene, in which mutations causing hereditary motor and sensory neuropathy (Dejerine-Sottas syndrome) have been identified. In SAMP6 we detected a p.S540fs frame-shift mutation in the Il4ra gene, a mutation potentially causative of ulcerative colitis and osteoporosis. Conclusions: Our data indicate that different combinations of mutations in disease-causing genes may be responsible for the various phenotypes of SAMP strains.ArticleBMC GENOMICS. 14:248 (2013)journal articl
Large-scale survey for novel genotypes of Plasmodium falciparum chloroquine-resistance gene pfcrt
Background. In Plasmodium falciparum, resistance to chloroquine (CQ) is conferred by a K to T mutation at amino acid position 76 (K76T) in the P. falciparum CQ transporter (PfCRT). To date, at least 15 pfcrt genotypes, which are represented by combinations of five amino acids at positions 72-76, have been described in field isolates from various endemic regions. To identify novel mutant pfcrt genotypes and to reveal the genetic relatedness of pfcrt genotypes, a large-scale survey over a wide geographic area was performed. Methods. Sequences for exon 2 in pfcrt, including known polymorphic sites at amino acid positions 72, 74, 75 and 76, were obtained from 256 P. falciparum isolates collected from eight endemic countries in Asia (Bangladesh, Cambodia, Lao P.D.R., the Philippines and Thailand), Melanesia (Papua New Guinea and Vanuatu) and Africa (Ghana). A haplotype network was constructed based on six microsatellite markers located -29 kb to 24 kb from pfcrt in order to examine the genetic relatedness among mutant pfcrt genotypes. Results. In addition to wild type (CVMNK at positions 72-76), four mutant pfcrt were identified; CVIET, CVIDT, SVMNT and CVMNT (mutated amino acids underlined). Haplotype network revealed that there were only three mutant pfcrt lineages, originating in Indochina, Philippines and Melanesia. Importantly, the Indochina lineage contained two mutant pfcrt genotypes, CVIET (n = 95) and CVIDT (n = 14), indicating that CVIDT shares a common origin with CVIET. Similarly, one major haplotype in the Melanesian lineage contained two pfcrt genotypes; SVMNT (n = 71) and CVMNT (n = 3). In Africa, all mutant pfcrt genotypes were the CVIET of the Indochina lineage, probably resulting from the intercontinental migration of CQ resistance from Southeast Asia. Conclusions. The number of CQ-mutant lineages observed in this study was identical to that found in previous studies. This supports the hypothesis that the emergence of novel CQ resistance is rare. However, in the mutant pfcrt genotypes, amino acid changes at positions 72, 74 and 75 appear to have recently been generated at least several times, producing distinct pfcrt mutant genotypes. The occurrence of new mutations flanking K76T may yield stronger resistance to CQ and/or a higher fitness than the original pfcrt mutant
ビオチン欠乏が及ぼすラット海馬への影響
ビオチン欠乏時および回復後のラット海馬歯状回のニューロジェネシスについて免疫組織化学的に検証した。Wistar系雄ラットを用いた。ビオチン欠乏(BD)群には生理食塩水を,対照(BS)群にはビオチン(200mg/kg)を毎日腹腔内投与し,5週間後に麻酔下で全放血後,脳を摘出し,20μmの連続凍結切片とした。切片は抗BrdU抗体と抗neuronal nuclei(NeuN)抗体の二重免疫染色,一部は抗polysialic acid(PSA)抗体による免疫染色,抗BrdU抗体と抗glial fibrillary acidic protein(GFAP)抗体を用いた二重免疫染色を実施し,海馬のニューロン新生部位である歯状回顆粒細胞層およびその下層(subgranular zone : SGZ)について行い,各染色における陽性細胞数をカウントした。新生ニューロンを示すBrdU/NeuN陽性細胞数とPSA陽性細胞数は,BS I群と比較してBD I群で有意(P<0.001)に減少していた。同様にSGZにおいて神経前駆細胞を示すGFAP/BrdU陽性細胞数についてもBD I群で減少する傾向(P=0.06)を示した。一方,回復期を設けたBD II群・BS II群においては,BrdU/NeuN陽性細胞数は両群間でほぼ同様の値を示し,PSA陽性細胞数はBD II群のほうがBS II群と比べて,増加する傾向(P=0.06)を示した。GFAP/BrdU陽性細胞数はBrdU/NeuNと同様に両群間でほぼ同様の値を示した。以上のことから,ビオチン欠乏状態では海馬歯状回のニューロジェネシスは抑制され,逆にビオチン欠乏状態回復後では対照群のそれと比べて同等のレベルまで改善することが示唆された。We previously confirmed that learning ability of a biotin-deficient (BD) rat decreased and LTP of its hippocampus was suppressed. In this study, the neurogenesis of hippocampal dentate gyruses of rats in BD conditions were investigated immunohistochemically. Wistar strain rats, 3-week-old, were fed BD diet. BD group was subjected to daily i.p. injection of saline for 5 weeks. Control (BS) group received same diet with daily injection of biotin (200,μg/kg, i.p.). The rats of the BD and BS groups were administered 5-Bromo-2\u27-deoxyuridine (BrdU, 50 mg/kg, i.p.) every 5 days, at a total of 4 times before autopsy. After exsanguination under anesthesia, the brains were removed, fixed with 4 % para-formaldehyde, sectioned 20 μm thick, and stained immunohistochemically with anti-neuronal nuclei (NeuN) and anti-BrdU antibodies. The numbers of BrdU positive cells of BD and BS were 39.1 ± 1.0 and 53.0 ± 0.8, respectively, and the numbers of BrdU/NeuN positive cells were 26.8 ± 0.7 and 39.3 ± 0.6, respectively. Both numbers of BrdU and BrdU/NeuN positive cells of the BD group showed significantly small values (p < 0.001). The neurogenesis of the hippocampus was suppressed in the BD condition. This suggests that biotin has an important role in the development and maintenance of brain functions
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