A new gene encoding tRNAPro (GGG) is present in the chloroplast genome of black pine: a compilation of 32 tRNA genes from black pine chloroplasts

The chloroplast genome of black pine (Pinus thumbergii), a gymnosperm, contains 32 different tRNA genes, 30 of which correspond to those previously identified in tobacco and rice chloroplast genomes. Two additional genes encode tRNA^Pro (GGG) and tRNA^Arg (CCG); the former is newly identified while the latter is present in liverwort, Physcomitrella patens and Angiopteris lygodiifolia, chloroplast genomes. Moreover, a partial copy of the split tRNA^Gly (UCC) gene and full copies of tRNA^His (GUG), tRNA^Thr (GGU) and tRNA^Ser (GCU) genes are present in the large single-copy region of the genome, suggesting extensive rearrangements of the chloroplast genome during evolutio. No tRNA genes whose tRNA products can recognize codons CUU/C (Leu) and GCU/C (Ala) have been found. We propose that the 32 tRNAs are sufficient to read all the 61 sense codons in the black pine system using the two-out-of-three and the U:N wobble mechanisms.     

Cohesin release is required for sister chromatid resolution,but not for condensin-mediated compaction,at the onset of mitosis

The establishment of metaphase chromosomes is an essential prerequisite of sister chromatid separation in anaphase. It involves the coordinated action of cohesin and condensin, protein complexes that mediate cohesion and condensation, respectively. In metazoans, most cohesin dissociates from chromatin at prophase, coincident with association of condensin. Whether loosening of cohesion at the onset of mitosis facilitates the compaction process, resolution of the sister chromatids, or both, remains unknown. We have found that the prophase release of cohesin is completely blocked when two mitotic kinases, aurora B and polo-like kinase (Plx1), are simultaneously depleted from Xenopus egg extracts. Condensin loading onto chromatin is not affected under this condition, and rod-shaped chromosomes are produced that show an apparently normal level of compaction. However, the resolution of sister chromatids within these chromosomes is severely compromised. This is not because of inhibition of topoisomerase II activity that is also required for the resolution process. We propose that aurora B and Plx1 cooperate to destabilize the sister chromatid linkage through distinct mechanisms that may involve phosphorylation of histone H3 and cohesin, respectively. More importantly, our results strongly suggest that cohesin release at the onset of mitosis is essential for sister chromatid resolution but not for condensin-mediated compaction.     

No evidence of PEG1/MEST gene mutations in Silver‐Russell syndrome patients

Silver‐Russell syndrome (SRS) is characterized by prenatal and postnatal growth retardation with morphologic anomalies. Maternal uniparental disomy 7 has been reported in some SRS patients. PEG1/MEST is an imprinted gene on chromosome 7q32 that is expressed only from the paternal allele and is a candidate gene for SRS. To clarify its biological function and role in SRS, we screened PEG1/MEST abnormalities in 15 SRS patients from various standpoints. In the lymphocytes of SRS patients, no aberrant expression patterns of two splice variants (α and β) of PEG1/MEST were detected when they were compared with normal samples. Direct sequence analysis failed to detect any mutations in the PEG1/MEST α coding region, and there were no significant mutations in the 5′‐flanking upstream region containing the predicted promoter and the highly conserved human/mouse genomic region. Differential methylation patterns of the CpG island for PEG1/MEST α were normally maintained and resulted in the same pattern as in the normal control, suggesting that there was no loss of imprinting. These findings suggest that PEG1/MEST can be excluded as a major determinant of SRS. © 2001 Wiley‐Liss, Inc.     

Further insight into the task-dependent excitability of motor evoked potentials in first dorsal interosseous muscle in humans

We have reexamined the contradictory evidence in which task-dependent excitation of motor evoked potentials (MEPs) in the first dorsal interosseous (FDI) muscle was stronger with increasingly more complex finger tasks than with individual finger movement tasks. In the first step of the experiment, based on previous findings, we investigated remarkable functional differences between intrinsic and extrinsic hand muscles during complex finger tasks (precision and power grip). During the performance of the tasks, the optimal stimulus intensity of the transcranial magnetic stimulation (TMS) was applied to the contralateral motor cortex. MEPs of the FDI, extensor carpi radialis (ECR), and flexor carpi radialis (FCR) muscles were recorded simultaneously with increased background EMG activity step by step in both tasks. The intensity threshold of TMS was lower in the precision grip. Furthermore, the MEP amplitudes of FDI muscle dependent on the background EMG activity were different between these two tasks, i.e., MEP amplitudes and regression coefficients in a precision grip were larger than those in a power grip. Although our results for MEP amplitude and threshold in the FDI muscle were similar to previous reported evidence, the different contributions of a synergistic muscle (in particular, the ECR muscle) during performance in these tasks was new evidence. Since there were no differences in cutaneous afferent effects on both tasks, corticomotoneuronal (CM) cells connected to FDI motoneurons seemed generally to be more active during precision than power gripping, and there were different contributions from synergistic muscles during the performance of these tasks. In the second part of the experiment, the results obtained from the complex tasks were compared with those from a simple task (isolated index finger flexion). MEP amplitudes, dependent on the background EMG activity during isolated index finger flexion, varied among subjects, i.e., the relationship between the MEP amplitude and the background EMG of the FDI muscle showed individual, strategy-dependent modulation. There were several kinds of individual motor strategies for performing the isolated finger movement. The present results may explain the previous contradictory evidence related to the contribution of the CM system during coordinated finger movement.     

Retrosigmoid Approach in the Supine Position Using ORBEYE: A Consecutive Series of 14 Cases

One of the merits of recently introduced exoscopes, including ORBEYE, is that they are superior to a conventional microscope in terms of ergonomic features. Taking advantage of it, the retrosigmoid approach can be performed in the supine position using ORBEYE. We report a consecutive series of 14 operations through the retrosigmoid approach in the supine position using ORBEYE. Fourteen consecutive patients who underwent surgery through the retrosigmoid approach for cerebellopontine (CP) angle lesions in the supine position using ORBEYE were targeted, and surgical outcomes and complications were examined. We evaluated the posture of the operator and the surgical field during this approach compared with those using a conventional microscope. In all 14 cases, all operative procedures were accomplished only using the ORBEYE. There were no operative complications due to this approach. Using ORBEYE, even when the angle of the operative visual axis was horizontal, the operators could manipulate in a comfortable posture. They were not forced to be in an uncomfortable posture that extended their arms, as is often the case with a conventional microscope. Therefore, they could use shorter surgical instruments. As the cerebellum shifted downward with gravity even using slight retraction during this approach, the working space of the surgical field was easily secured. Through this approach, the operators can perform stable microsurgery of CP angle lesions in a comfortable posture. This approach can reduce the burden on the operator and the patient, leading to a refined surgical procedure.     

Characteristics affecting cervical sagittal alignment in patients with chronic low back pain

BackgroundSagittal spino-pelvic malalignment in patients with chronic low back pain (CLBP) have been reported in the past, which may also affect cervical spine lesions. The purpose of this study is to investigate the cervical alignment in patients with CLBP.MethodOf the patients who visited an orthopedic specialist due to low back pain lasting more than three months, 121 cases (average 71.5-years-old, 46 male and 75 female) with whole standing spinal screening radiographs were reviewed (CLBP group). Cervical parameters included cervical lordosis (CL), C2–C7 sagittal vertical axis (C2-7 SVA), and the T1 slope minus CL (T1S-CL). Cervical spine deformity was defined as C2-7 SVA >4 cm, CL <0°, or T1S-CL ≧20°. We compared the cervical alignment of these patients with 121 age and gender matched volunteers (control group).ResultsThe prevalence of cervical spine deformity was significantly higher in the CLBP group than in the control group (20.7% vs. 10.7%, P = 0.034). The mean CL was smaller in the CLBP group than in the control group (16.1° vs. 21.4°, P = 0.002). The mean C2-7 SVA was 17.6 mm vs. 18.7 mm in the CLBP group and in the control group, respectively (P = 0.817). The mean T1S-CL was larger in the CLBP group than in the control group (9.1° vs. 3.5°, P < 0.001). Multivariate analysis showed that people with CLBP were more likely to have cervical deformities than people without CLBP (odds ratio 2.16, 95% confidence interval 1.006 to 4.637).ConclusionsThis study results suggest that people with CLBP present with worse cervical sagittal alignment and higher prevalence of cervical spine deformities than age and gender matched volunteers with no CLBP. This means CLBP impacts cervical spine lesions negatively.Level of evidenceⅣ     

Functional transition: Inconsistently parallel to the increase in future liver remnant volume after preoperative portal vein embolization

BACKGROUNDPreoperative portal vein embolization (PVE) is a widely used strategy to enable major hepatectomy in patients with insufficient liver remnant. PVE induces hypertrophy of the future liver remnant (FLR) and a shift of the functional reserve to the FLR. However, whether the increase of the FLR volume (FLRV) corresponds to the functional transition after PVE remains unclear.AIMTo investigate the sequential relationship between the increase in FLRV and functional transition after preoperative PVE using 3-dimensional (3D) computed tomography (CT) and ^99mTc-galactosyl-human serum albumin (^99mTc-GSA) single-photon emission computed tomography (SPECT) fusion images. METHODSThirty-three patients who underwent major hepatectomy following PVE at the Department of Gastroenterological Surgery I, Hokkaido University Hospital between October 2013 and March 2018 were enrolled. Three-phase dynamic multidetector CT and ^99mTc-GSA SPECT scintigraphy were performed at pre-PVE, and at 1 and 2 wk after PVE; 3D ^99mTc-GSA SPECT CT-fused images were constructed from the Digital Imaging and Communications in Medicine data using 3D image analysis system. Functional FLRV (FFLRV) was defined as the total liver volume × (FLR volume counts/total liver volume counts) on the 3D ^99mTc-GSA SPECT CT-fused images. The calculated FFLRV was compared with FLRV.RESULTSFFLRV increased by a significantly larger extent than FLRV at 1 and 2 wk after PVE (P < 0.01). The increase in FFLRV and FLRV was 55.1% ± 41.6% and 26.7% ± 17.8% (P < 0.001), respectively, at 1 wk after PVE, and 64.2% ± 33.3% and 36.8% ± 18.9% (P < 0.001), respectively, at 2 wk after PVE. In 3 of the 33 patients, FFLRV levels decreased below FLRV at 2 wk. One of the three patients showed rapidly progressive fatty changes in FLR. The biopsy at 4 wk after PVE showed macro- and micro-vesicular steatosis of more than 40%, which improved to 10%. Radical resection was performed at 13 wk after PVE. The patient recovered uneventfully without any symptoms of pos-toperative liver failure.CONCLUSIONThe functional transition lagged behind the increase in FLRV after PVE in some cases. Evaluating both volume and function is needed to determine the optimal timing of hepatectomy after PVE.     

A multi-institutional survey of the quality of life after treatment for uterine cervical cancer: a comparison between radical radiotherapy and surgery in Japan

This study aimed to research the post-treatment quality of life (QOL) between radiotherapy (RT)- and operation (OP)-treated early cervical cancer survivors, using separate questionnaires for physicians and patients. We administered an observational questionnaire to patients aged 20–70 years old with Stages IB1–IIB cervical cancer who had undergone RT or OP and without recurrence as outpatients for ≥6 months after treatment. We divided 100 registered patients equally into two treatment groups (n = 50 each). The average age was 53 and 44 years in the RT and OP groups, respectively. The RT group included 34 and 66% Stage I and II patients, respectively, whereas the OP group included 66 and 34% Stage I and II patients, respectively. The OP group included 58% of patients with postoperative RT. Combination chemotherapy was performed in 84 and 48% of patients in the RT and OP groups, respectively. On the physicians’ questionnaire, we observed significant differences in bone marrow suppression (RT) and leg edema (OP). On the patients’ questionnaire, significantly more patients had dysuria and leg edema in the OP group than in the RT group, and severe (Score 4–5) leg edema was significantly higher in the post-operative RT group than in the OP only group. The frequency of sexual intercourse decreased after treatment in both groups. On the patients’ questionnaire, there were no significant differences between the two groups regarding sexual activity. These findings are useful to patients and physicians for shared decision-making in treatment choices. The guidance of everyday life and health information including sexual life after treatment is important.     

Study on allergic rhinitis in workers exposed to methyltetrahydrophthalic anhydride

Methylterahydrophthalic anhydride (MTHPA) is used as a hardening agent in an epoxy resin system. Because work-related nasal symptoms were observed in some workers exposed toMTHPA at two condenser plants, a cross-sectional survey was performed to improve their work environment. MeanMTHPA levels in the manufacturing processes to which the workers were routinely assigned were extremely low (1.09-22.4 μg/m3). However, specific IgE antibody (S-IgE) was detected in 9 (32%) of 28 workers. Of these, 8 (89%) had nasal symptoms. An IgE-mediated mechanism seems to be associated with at least some of the cases of work-related nasal symptoms. This indicates that the occupational health administration ofMTHPA cannot be controlled simply by limiting exposure in the work environment. Total IgE (T-IgE) levels were significantly higher in S-IgE-positive workers than in S-IgE-negative workers (geometric mean, 200.5 and 51.3 IU/ml, respectively; p<0.002, unpaired t test). These findings demonstrate that workers in whom S-IgE is less likely to be produced, i.e., those in whom the T-IgE level is 80 IU/ml or less, should be assigned to work in these manufacturing processes.     

Diurnal variation in neutrophil function

Neutrophil functions, including chemotaxis, reactive oxygen species (ROS)-producing capacity of neutrophils, and serum opsonic activity were investigated in 9 young healthy male volunteers. Venous blood of these volunteers was obtained under standardized conditions at 4-h intervals over a 24-h span. Neutrophil chemotaxis was evaluated by a modified Boyden technique, ROS-producing capacity of neutrophils and serum opsonic activity were measured by a simultaneous multiple measurement system based on luminol-dependent chemiluminescence and indicated by peak height and peak time. ROS-producing capacity of neutrophils and serum opsonic activity were activated in the daytime, and decreased from night to morning. There were negative correlations between the peak time of the luminol-dependent chemiluminescent response, neutrophil number (p<0.01) and segmented neutrophil number (p>0.01). On the other hand, no significant correlations were noted between serum opsonic activity and IgG, IgA, IgM, C3 or C4. In contrast, the peaks of neutrophil chemotaxis were at the wake-up time (6:00a.m.) and in the evening (6:00p.m.). This study indicates that diurnal variation of neutrophil function exists.