Ancient genomics reveals tripartite origins of Japanese populations.

Prehistoric Japan underwent rapid transformations in the past 3000 years, first from foraging to wet rice farming and then to state formation. A long-standing hypothesis posits that mainland Japanese populations derive dual ancestry from indigenous Jomon hunter-gatherer-fishers and succeeding Yayoi farmers. However, the genomic impact of agricultural migration and subsequent sociocultural changes remains unclear. We report 12 ancient Japanese genomes from pre- and postfarming periods. Our analysis finds that the Jomon maintained a small effective population size of ~1000 over several millennia, with a deep divergence from continental populations dated to 20,000 to 15,000 years ago, a period that saw the insularization of Japan through rising sea levels. Rice cultivation was introduced by people with Northeast Asian ancestry. Unexpectedly, we identify a later influx of East Asian ancestry during the imperial Kofun period. These three ancestral components continue to characterize present-day populations, supporting a tripartite model of Japanese genomic origins.

Minichromosome formation in Chlorella cells irradiated with electron beams.

Three minichromosomes, miniP7, miniB7, and miniK4 of 800 kbp, 450 kbp, and 550 kbp, respectively, were obtained from Chlorella vulgaris chromosome I by electron-beam irradiation. Two of them were structurally characterized: MiniP7 was formed by the deletion of an internal 180 kbp close to the right end of chromosome I. The 180-kbp region with a small interspersed nuclear element (SINE)-like element on its left terminus was translocated to another chromosome, leaving a footprint-like structure on miniP7. MiniB7 was a hybrid of chromosome I and another chromosome, retaining the left telomere and the centromere of chromosome I. The centromeric repetitive elements served as a rearrangement point in the miniB7 formation. These examples showed the complicated mechanisms involved in the minichromosome formation. The minichromosomes thus obtained can be useful for isolating the fundamental structural elements of a chromosome. Moreover, they may serve as starting materials or a vector to generate artificial chromosomes carrying useful genes.

[Efficacy of propofol in controlling myoclonus during rewarming in a brain hypothermia patient].

Propofol is an intravenous anaesthetic agent having anticonvulsant property. We report here a case in which propofol was effective in controlling myoclonus during rewarming in brain hypothermia patient. A 35-year-old male patient was admitted in a comatose state with right-sided hemiparesis, anisocoria and absence of bilateral light reflex. On admission, a head CT showed traumatic subarachnoid hemorrhage, left subdural hematoma, 10 mm midline shift and tentorial herniation with massive brain swelling together with extensive hypodensity in the frontal, temporal and occipital lobes bilaterally. Left decompressive hemicraniectomy, removal of hematoma and brain hypothermia therapy were started immediately. Postoperative head CT showed 15 mm midline shift. The temperature of the jugular bulb was maintained at 34 degrees C for 2 days together with sedation using midazolam under artificial ventilation. The patient was gradually rewarmed at a rate of 0.5 degree C per day from the third hospital day. Myoclonus of sudden onset developed on the patient's head and upper extremities on the third hospital day. An intravenous bolus injection of 10 mg midazolam and continued intravenous infusion of midazolam were given but they did not completely stop myoclonus. A bolus of propofol 60 mg was given intravenously and continuous intravenous infusion of propofol 2 mg.kg-1.hr-1 was started after which the progression of myoclonus disappeared. Myoclonus was kept controlled until the continuous intravenous infusion of midazolam and propofol was discontinued on the sixth hospital day, after which myoclonus occurred again after extubation on the seventh hospital day. The clinical course of this case suggests that propofol might be an alternative effective agent to suppress refractory myoclonus.

[A case of multiple organ dysfunction following postoperative epididymitis].

We report a case of multiple organ dysfunction following epididymitis. A 53-year-old male patient was admitted to our emergency room with bilateral clavicular fractures, multiple costal fractures and left hemopneumothorax due to a traffic accident. Open reduction of the right clavicular fracture was performed under general anesthesia on the sixth hospital day. A bladder balloon catheter was inserted after induction of anesthesia. The clinical course in the perioperative period was satisfactory and the bladder balloon catheter was removed on the seventh hospital day. However, spontaneous left scrotal pain with tenderness, intense heat with swelling developing on the tenth hospital day, and hypotension, dyspnea and oliguria were noted on the eleventh hospital day. Blood chemistry data showed severe inflammatory findings. Chest X-ray showed acute respiratory distress syndrome. Blood coagulation data showed pre-disseminated intravascular coagulation. The patient's condition continued to deteriorate and we suspected septic shock due to left epididymitis. Emergent left orchiectomy was performed under local anesthesia on the twelfth hospital day. Postoperatively he recovered rapidly. We consider that multiple organ dysfunction following postoperative epididymitis was caused by cytokines released due to systemic inflammatory response syndrome (SIRS) after the trauma, operation, and placement of the bladder catheter. In conclusion, it is important to note that patients with SIRS should undergo further examinations of septic shock immediately and resection of the causative tissue should be performed as soon as possible.