287 research outputs found
Three-nucleon interactions: dynamics
A discussion is presented of the dynamics underlying three-body nuclear
forces, with emphasis on changes which occurred over several decades.Comment: Talk given at the FM50 symposium, Tokyo, October 200
Dynamic view of the nuclear matrix.
The nuclear matrix is an operationally defined nuclear skeletal structure that is believed to be involved in many nuclear functions including DNA replication, transcription, repair, and prem RNA processing/transport. Until relatively recently, the nuclear matrix was thought to be a rigid and static structure, but it is now thought to be dynamic. This paradigm shift was based in part on the tracking of the intranuclear movement of proteins tagged with fluorochromes. In this review, we attempt to redefine the nuclear matrix in light of recent findings and describe some useful techniques for the dynamic analysis of nuclear function.</p
Behavior tests and immunohistochemical retinal response analyses in RCS rats with subretinal implantation of Okayama-University-type retinal prosthesis
We have developed a photoelectric dye-coupled polyethylene film as a prototype of retinal prosthesis, which we named Okayama University-type retinal prosthesis. The purposes of this study are to conduct behavior tests to assess vision in Royal College of Surgeons (RCS) rats that underwent subretinal implantation of the dye-coupled film and to reveal retinal response to the dye-coupled film by immunohistochemistry. Polyethylene films were made of polyethylene powder at refined purity, and photoelectric dyes were coupled to the film surface at higher density compared with the prototype. Either dye-coupled film or dye-uncoupled plain film used as a control was implanted subretinally from a scleral incision in both eyes of an RCS rat at 6 weeks of the age. Behavior tests 2, 4, 6, and 8 weeks after implantation were conducted by observing head turning or body turning in the direction consistent with clockwise or counterclockwise rotation of a black-and-white-striped drum around a transparent cage housed with the rat. After the behavior tests at 8 weeks, rats' eyes were enucleated to confirm subretinal implantation of the films and processed for immunohistochemistry. In the behavior tests, the number of head turnings consistent with the direction of the drum rotation was significantly larger in RCS rats with dye-coupled- compared with plain-film implantation [P < 0.05, repeated-measure analysis of variance (ANOVA), n = 7]. The number of apoptotic neurons was significantly smaller in eyes with dye-coupled- compared with plain-film implantation (P < 0.05, Mann-Whitney U test, n = 6). In conclusion, subretinal implantation of photoelectric dye-coupled films restored vision in RCS rats and prevented the remaining retinal neurons from apoptosis
Topoisomerase II beta targets DNA crossovers formed between distant homologous sites to induce chromatin opening
Type II DNA topoisomerases (topo II) flip the spatial positions of two DNA duplexes, called G- and T- segments, by a cleavage-passage-resealing mechanism. In living cells, these DNA segments can be derived from distant sites on the same chromosome. Due to lack of proper methodology, however, no direct evidence has been described so far. The beta isoform of topo II (topo II beta) is essential for transcriptional regulation of genes expressed in the final stage of neuronal differentiation. Here we devise a genome-wide mapping technique (eTIP-seq) for topo II beta target sites that can measure the genomic distance between G- and T-segments. It revealed that the enzyme operates in two distinctive modes, termed proximal strand passage (PSP) and distal strand passage (DSP). PSP sites are concentrated around transcription start sites, whereas DSP sites are heavily clustered in small number of hotspots. While PSP represent the conventional topo II targets that remove local torsional stresses, DSP sites have not been described previously. Most remarkably, DSP is driven by the pairing between homologous sequences or repeats located in a large distance. A model-building approach suggested that topo II beta acts on crossovers to unknot the intertwined DSP sites, leading to chromatin decondensation
Effects of a novel method of anesthesia combining propofol and volatile anesthesia on the incidence of postoperative nausea and vomiting in patients undergoing laparoscopic gynecological surgery
AbstractBackgroundWe investigated the effects of a novel method of anesthesia combining propofol and volatile anesthesia on the incidence of postoperative nausea and vomiting in patients undergoing laparoscopic gynecological surgery.MethodsPatients were randomly divided into three groups: those maintained with sevoflurane (Group S, n=42), propofol (Group P, n=42), or combined propofol and sevoflurane (Group PS, n=42). We assessed complete response (no postoperative nausea and vomiting and no rescue antiemetic use), incidence of nausea and vomiting, nausea severity score, vomiting frequency, rescue antiemetic use, and postoperative pain at 2 and 24h after surgery.ResultsThe number of patients who exhibited a complete response was greater in Groups P and PS than in Group S at 0–2h (74%, 76% and 43%, respectively, p=0.001) and 0–24h (71%, 76% and 38%, respectively, p<0.0005). The incidence of nausea at 0–2h (Group S=57%, Group P=26% and Group PS=21%, p=0.001) and 0–24h (Group S=62%, Group P=29% and Group PS=21%, p<0.0005) was also significantly different among groups. However, there were no significant differences among groups in the incidence or frequency of vomiting or rescue antiemetic use at 0–24h.ConclusionCombined propofol and volatile anesthesia during laparoscopic gynecological surgery effectively decreases the incidence of postoperative nausea. We term this novel method of anesthesia “combined intravenous-volatile anesthesia (CIVA)”
Changes of pulse wave transit time after haemodynamic manoeuvres in healthy adults : a prospective randomised observational trial (PWTT volunteer study)
Background:
Pulse wave transit time (PWTT) shows promise for monitoring intravascular fluid status intraoperatively. Presently, it is unknown how PWTT mirrors haemodynamic variables representing preload, inotropy, or afterload.
Methods:
PWTT was measured continuously in 24 adult volunteers. Stroke volume was assessed by transthoracic echocardiography. Volunteers underwent four randomly assigned manoeuvres: ‘Stand-up’ (decrease in preload), passive leg raise (increase in preload), a ‘step-test’ (adrenergic stimulation), and a ‘Valsalva manoeuvre’ (increase in intrathoracic pressure). Haemodynamic measurements were performed before and 1 and 5 min after completion of each manoeuvre. Correlations between PWTT and stroke volume were analysed using the Pearson correlation coefficient.
Results:
‘Stand-up’ caused an immediate increase in PWTT (mean change +55.9 ms, P-value <0.0001, 95% confidence interval 46.0–65.7) along with an increase in mean arterial pressure and heart rate and a drop in stroke volume (P-values <0.0001). Passive leg raise caused an immediate drop in PWTT (mean change −15.4 ms, P-value=0.0024, 95% confidence interval −25.2 to −5.5) along with a decrease in mean arterial pressure (P-value=0.0052) and an increase in stroke volume (P-value=0.001). After 1 min, a ‘step-test’ caused no significant change in PWTT measurements (P-value=0.5716) but an increase in mean arterial pressure and heart rate (P-values <0.0001), without changes in stroke volume (P-value=0.1770). After 5 min, however, PWTT had increased significantly (P-value <0.0001). Measurements after the Valsalva manoeuvre caused heterogeneous results.
Conclusion:
Noninvasive assessment of PWTT shows promise to register immediate preload changes in healthy adults. The clinical usefulness of PWTT may be hampered by late changes because of reasons different from fluid shifts
Case report: a case of intractable Meniere's disease treated with autogenic training
<p>Abstract</p> <p>Background</p> <p>Psychological stress plays an important role in the onset and course of Meniere's disease. Surgical therapy and intratympanic gentamicin treatment are options for cases that are intractable to conventional medical therapy. Psychotherapy, however, including autogenic training (AT), which can be used for general relaxation, is not widely accepted. This paper describes the successful administration of AT in a subject suffering from intractable Meniere's disease.</p> <p>Case presentation</p> <p>A 51-year-old male patient has suffered from fluctuating right sensorineural hearing loss with vertigo since 1994. In May 2002, he was first admitted to our hospital due to a severe vertigo attack accompanied by right sensorineural hearing loss. Spontaneous nystagmus toward the right side was observed. Since April 2004, he has experienced vertigo spells with right-sided tinnitus a few times per month that are intractable to conventional medical therapy. After four months, tympanic tube insertion was preformed in the right tympanic membrane. Intratympanic injection of dexamethasone was ineffective. He refused Meniett therapy and intratympanic gentamicin injection. In addition to his vertigo spells, he suffered from insomnia, tinnitus, and anxiety. Tranquilizers such as benzodiazepines and antidepressants such as serotonin selective re-uptake inhibitors (SSRIs) failed to stop the vertigo and only slightly improved his insomnia. In December 2006, the patient began psychological counseling with a psychotherapist. After brief psychological counseling along with cognitive behavior therapy (CBT), he began AT. He diligently and regularly continued his AT training in his home according to a written timetable. His insomnia, tinnitus, and vertigo spells disappeared within a few weeks after only four psychotherapy sessions. In order to master the six standard formulas of AT, he underwent two more sessions. Thereafter, he underwent follow-up for 9 months with no additional treatment. He is now free from drugs, including tranquilizers, and has continued AT. No additional treatment was performed. When we examined him <b>six </b>and nine months later for follow-up, he was free of vertigo and insomnia.</p> <p>Conclusion</p> <p>AT together with CBT can be a viable and palatable treatment option for Meniere's disease patients who are not responsive to other therapies.</p
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