Sign of Hard-X-Ray Pulsation from the γ-Ray Binary System LS 5039.

To understand the nature of the brightest γ-ray binary system LS 5039, hard x-ray data of the object, taken with the Suzaku and NuSTAR observatories in 2007 and 2016, respectively, were analyzed. The two data sets jointly gave tentative evidence for a hard x-ray periodicity, with a period of ∼9 s and a period increase rate by ∼3×10^{-10} s s^{-1}. Therefore, the compact object in LS 5039 is inferred to be a rotating neutron star, rather than a black hole. Furthermore, several lines of arguments suggest that this object has a magnetic field of several times ∼10^{10} T, two orders of magnitude higher than those of typical neutron stars. The object is hence suggested to be a magnetar, which would be the first to be found in a binary. The results also suggest that the highly efficient particle acceleration process, known to be operating in LS 5039, emerges through interactions between dense stellar winds from the massive primary star, and ultrastrong magnetic fields of the magnetar.

Downward Terrestrial Gamma-Ray Flash Observed in a Winter Thunderstorm.

During a winter thunderstorm on 24 November 2017, a strong burst of gamma rays with energies up to ∼10 MeV was detected coincident with a lightning discharge, by scintillation detectors installed at the Kashiwazaki-Kariwa Nuclear Power Station at sea level in Japan. The burst had a subsecond duration, which is suggestive of photoneutron production. The leading part of the burst was resolved into four intense gamma-ray bunches, each coincident with a low-frequency radio pulse. These bunches were separated by 0.7-1.5 ms, with a duration of ≪1 ms each. Thus, the present burst may be considered as a "downward" terrestrial gamma-ray flash (TGF), which is analogous to upgoing TGFs observed from space. Although the scintillation detectors were heavily saturated by these bunches, the total dose associated with them was successfully measured by ionization chambers, employed by nine monitoring posts surrounding the power plant. From this information and Monte Carlo simulations, the present downward TGF is suggested to have taken place at an altitude of 2500±500 m, involving 8_{-4}^{+8}×10^{18} avalanche electrons with energies above 1 MeV. This number is comparable to those in upgoing TGFs.

Possible evidence for free precession of a strongly magnetized neutron star in the magnetar 4U 0142+61.

Magnetars are a special type of neutron stars, considered to have extreme dipole magnetic fields reaching ∼ 10(11) T. The magnetar 4 U 0142+61, one of the prototypes of this class, was studied in broadband x rays (0.5-70 keV) with the Suzaku observatory. In hard x rays (15-40 keV), its 8.69 sec pulsations suffered slow phase modulations by ± 0.7 sec, with a period of ∼ 15 h. When this effect is interpreted as free precession of the neutron star, the object is inferred to deviate from spherical symmetry by ∼ 1.6 × 10(-4) in its moments of inertia. This deformation, when ascribed to magnetic pressure, suggests a strong toroidal magnetic field, ∼ 10(12) T, residing inside the object. This provides one of the first observational approaches towards toroidal magnetic fields of magnetars.

Hardening and termination of long-duration γ rays detected prior to lightning.

We report the first observation of 3-30 MeV prolonged gamma-ray emission that was abruptly terminated by lightning. The gamma-ray detection was made during winter thunderstorms on December 30, 2010, by the Gamma-Ray Observation of Winter Thunderclouds experiment carried out in a coastal area along the Sea of Japan. The gamma-ray flux lasted for less than 3 min, continuously hardening closer to the lightning occurrence. The hardening at energies of 3-10 MeV energies was most prominent. The gamma-ray flux abruptly ceased less than 800 ms before the lightning flash that occurred over 5 km away from the experimental site. In addition, we observed a clear difference in the duration of the 3-10 MeV gamma rays and those >10 MeV, suggesting that the area of >10 MeV gamma-ray emission is considerably smaller than that of the lower-energy gamma rays. This work may give a manifestation that a local region emitting prolonged gamma rays connects with a distant region to initiate lightning.

The yohkoh mission for high-energy solar physics.

The Japanese Yohkoh satellite is now in orbit observing the sun with a set of x-ray imagers and x-ray and gamma-ray spectrometers. The data from this successful mission provide new information on solar flares and the sun's corona. This paper discusses the Yohkoh observations and presents a sample of the first scientific results from the mission.

Transcriptional activation of the human HMG1 gene in cisplatin-resistant human cancer cells.

The nonhistone chromosomal protein, high mobility group 1 (HMG1), which is ubiquitously expressed in higher eukaryotic cells, preferentially binds to cisplatin-modified DNA. The observation that HMG1 is overexpressed in cisplatin-resistant human cancer cells suggests that cisplatin resistance may be closely associated with HMG1. To decipher the mechanism of HMG1 overexpression in cisplatin-resistant cells, we isolated two overlapping genomic DNA clones containing the entire human HMG1 gene. These clones, which span approximately 15 kb of contiguous DNA, include 5 kb of the 5' flanking region as well as the entire coding sequence. We sequenced 1500 bp upstream of the first exon. The segment proximal to the transcription initiation site did not contain a TATA box but did possess an activating transcription factor site, an activator protein-2 site, one CCAAT box, and two CCAAT-binding transcription factor/nuclear factor-1 (CTF/NF-1) sites. HMG1 promoter activity was 3-10-fold higher in cisplatin-resistant KB-CP20 cells than in parental KB cells. An in vivo footprint experiment showed several differences of dimethyl sulfate modifications between KB and KB-CP20 cells in the area around the CTF/NF-1 sites. In addition, electrophoretic gel mobility shift assays showed that binding of a nuclear factor from cisplatin-resistant cells to the CTF/NF-1 site was significantly higher than the binding of the same factor from parental cells. Semiquantitative reverse transcription-PCR and Western blot analysis also showed that expression of CTF/NF-1 was 3-20-fold higher in the resistant cell line than in its parental counterpart. These findings suggest that, in cisplatin-resistant cells, the expression of HMG1 gene product is enhanced at the transcriptional level and that this probably occurs through the enhanced expression of the CCAAT binding factor, CTF/NF-1.

On-ground detection of an electron-positron annihilation line from thunderclouds.

Thunderclouds can produce bremsstrahlung gamma-ray emission, and sometimes even positrons. At 00:27:00 (UT) on 13 January 2012, an intense burst of gamma rays from a thundercloud was detected by the GROWTH experiment, located in Japan, facing the Sea of Japan. The event started with a sharp gamma-ray flash with a duration of <300 ms coincident with an intracloud discharge, followed by a decaying longer gamma-ray emission lasting for ∼60 s. The spectrum of this prolonged emission reached ∼10 MeV, and contained a distinct line emission at 508±3(stat.)±5(sys.) keV, to be identified with an electron-positron annihilation line. The line was narrow within the instrumental energy resolution (∼80keV), and contained 520±50 photons which amounted to ∼10% of the total signal photons of 5340±190 detected over 0.1-10 MeV. As a result, the line equivalent width reached 280±40 keV, which implies a nontrivial result. The result suggests that a downward positron beam produced both the continuum and the line photons.

Effects of histamine and interleukin-4 synthesized in arterial intima on phagocytosis by monocytes/macrophages in relation to atherosclerosis.

We investigated the localization of histidine decarboxylase (HDC), which is the rate-limiting enzyme that generates histamine from histidine, in human aorta/coronary artery. RT-PCR and immunohistochemical staining revealed that the HDC gene was expressed in monocytes/macrophages and T cells in the arterial intima but not in smooth muscle cells in either the arterial intima or the media. A luciferase promoter assay with U937 and Jurkat cells demonstrated that interleukin-4 (IL-4) inhibited the expression of the HDC gene. In contrast, among a scavenger receptor family, IL-4 as well as histamine up-regulated U937 cells to express the LOX-1 gene but not the SR-A gene, which genes encode receptors that scavenge oxidized lipids. These findings suggest that histamine synthesized in the arterial wall participates in the initiation and progression of atherosclerosis and that IL-4 can act as an important inhibitory and/or stimulatory factor in the function of monocytes/macrophages modulated by histamine in relation to the process of atherosclerosis.

Evaluation of bedmaking-related airborne and surface methicillin-resistant Staphylococcus aureus contamination.

The number of airborne methicillin-resistant Staphylococcus aureus (MRSA) before, during and after bedmaking was investigated. Air was sampled with an Andersen air sampler in the rooms of 13 inpatients with MRSA infection or colonization. Sampling of surfaces, including floors and bedsheets, was performed by stamp methods. MRSA-containing particles were isolated on all the sampler stages-stage 1 (>7 microm diameter) to stage 6 (0.65-1.1 microm). The MRSA-containing particles were mostly 2-3 microm diameter before bedmaking and >5 microm during bedmaking. The number was significantly higher 15 min after bedmaking than during the resting period, but the differences in counts after 30 and 60 min were not significant. MRSA was detected on many surfaces. The results suggest that MRSA was recirculated in the air, especially after movement. To prevent airborne transmission, healthcare staff should exercise great care to disinfect inanimate environments. Further studies will be needed to confirm the level of MRSA contamination of air during bedmaking and establish measures for prevention of airborne transmission.

Effects of acoustic overstimulation on 2f1-f2 distortion product in the cochlear microphonics.

The cochlear microphonics (CM) in response to two-tone stimuli as well as the threshold of compound action potential (CAP) were measured before and after exposure to 4 kHz pure tone at 100 dB SPL for 10 min. Although the loss of CM output at the primary frequencies was limited to around 2 dB, the 2f1-f2 distortion products in the CM (CM-DPs) were markedly reduced immediately after the exposure, especially at low primary levels (i.e. less than 65 dB). The low level CM-DPs recovered gradually near the initial level within 7 days from the exposure. The elevation of CAP threshold closely paralleled with the reduction of CM-DPs in not only the acute phase but also in the recovery phase from the exposure. These results show that the active transduction process in the cochlea was affected by acoustic overstimulation. This impairment of the active transduction was postulated to play an important role in developing the noise induced temporary threshold shift.

Differentiation of the rat stria vascularis.

The differentiation of the rat stria vascularis (SV) was investigated by light- and electron microscopy and by immunocytochemistry. Loss of the basal lamina at the epithelial-mesenchymal interface of SVs as indicated by immunoreactions of laminin and fibronectin induces the formation of vascular feet by basal infoldings of the marginal cells (MCs), and the development of the strial capillaries (SCs) by mesenchymal cells in a manner of vasculogenesis is progressing at the same time. The production of fibronectin in the rough endoplasmic reticulum of mesenchymal cells and the involvement of this glycoprotein in a mechanical linkage between the vasoformative mesenchymal cells and endothelial ones of the SCs are indicated by immunocytochemistry. The plasma membrane of the marginal cells (MCs) begins to show immunoreactions of Na+.K+ ATPase at postnatal day 5 and is conjugated to each other by tight junctions at postnatal day 14. The apical tubules of the differentiating MCs do not seem to be involved in the endocytotic activity but are involved in the plasma membrane supply for the rapid differentiation.

Immunoreactivity of endothelins and endothelin receptor in the stria vascularis of the mouse cochlea.

Immunoreactivities of endothelin-1, endothelin-3, endothelin receptor type A, and Na,K-ATPase were investigated in the stria vascularis of adult male WBB6F1 +/+ mice and in that of W/Wv mutants lacking strial intermediate cells. In the +/+ mice, electron microscopic immunoreactivity for the endothelins was seen on the rough endoplasmic reticulum, Golgi apparatus, cytoplasmic vesicles and lysosomes exclusively in the strial intermediate cells by the postembedment method. Immunoreactive endothelin receptor A was localized along the plasma membrane of strial marginal cells of both wild and mutant types although the immunoreactivity of the latter was much less than that of the former by the preembedment method. These findings suggest that the endothelins, which are produced in the strial intermediate cells, may play a role in the maintenance of the stria vascularis function in the +/+ mice. Since the plasma membrane of the marginal cells of the W/Wv mice, which do not generate a high positive endocochlear potential, also showed immunoreactivity for Na,K-ATPase, it seems likely that the endothelins are involved in the activation of sodium pump of the strial marginal cells by mediation of endothelin receptor A. In addition, the role of lysosomes in the crinophagy of the endothelins in the strial intermediate cells is proposed in the +/+ mice.

Electrophysiological responses from the cochlea and inferior colliculus in guinea pigs after head injury.

Electrical responses from the inferior colliculus (ER) and round window (CP) to acoustical stimuli were compared in control and experimental guinea pigs which had received a single blow to the freely movable head. After the blow to the head, all of the animals showed signs of commotio cerebri, and some of them died. The experimental animals were divided into two groups so that the physiologic responses to sound could be evaluated one day (early group) and seven days (intermediate group) following the head blow. The animals of the early group had elevated ER thresholds over the entire frequency range tested with an average threshold of 37.8 db. The animals of the intermediate group also had elevated ER thresholds which averaged 23.9 db. Input-output intensity function of ER for the experimental animals showed a recruitment-like phenomenon. The CP thresholds in the injured animals did not differ significantly from those in the control group. Damage to the VIIIth nerve and higher central pathways is very likely a more frequent cause of the otoneurologic manifestations following head injury than end organ damage.

Alveolar rhabdomyosarcoma of the ethmoid sinus.

A case of the alveolar rhabdomyosarcoma originating in the left ethmoid sinus was reported. Despite treatment by radical excision of the tumor, irradiation and chemotherapy, the patient died of generalized metastases of the tumor six months after surgery; however, no local recurrence of the tumor was found at an autopsy. The tumor was further studied by light and electron microscopic procedures.

Effects of head blow on the development of hearing loss.

The effects of the direction and intensity of the head blow and the effects of the lapse of time after a head blow on the development of hearing loss were studied in guinea pigs. The electrical responses from the right inferior colliculus (ER) and from the left round window (CP) to acoustic stimuli were measured. The elevation in threshold of the ER in the presence of normal CP in guinea pigs after a head blow suggests that the site of the lesion is central to the cochlea.

Histopathologic correlates of otoneurologic manifestations following head trauma.

The clinical course of patients dying of head trauma and the physiologic evaluation of audition in guinea pigs subjected to several forms of head trauma are correlated with the histopathologic findings in the brains and temporal bones. In the patients there was wide spread hemorrhage, edema, disorganization and disruption of neural tissue. Loss of Purkinje cells and other neural elements was prominent. The temporal bone findings in the patients included laceration of and hemorrhage into the VIIIth nerve as well as bleeding into the scala tympani. The membranous labyrinths demonstrated no specific changes secondary to the trauma. The guinea pigs developed a central form of hearing loss with elevated thresholds for evoked responses from the inferior colliculus and normal AC cochlear potentials. In the animals hemorrhage in the substance of the brain, necrosis of neural tissue, edema, disorganization and disruption were prominent. Although there was extravasation of blood in the tympanic and vestibular scalae, the membranous structures of the inner ears were well preserved.

Local immune system in the developing fetal larynx.

Using histopathological and immunofluorescent techniques, we investigated the development of the glandular system of the larynx from 12 human fetuses. Glandular buds were first observed at the fourth month of gestation and glandular distribution became evident from the fifth month in the larynx. Ciliated or nonciliated epithelium covered the cavity of the larynx, with the exception of the true vocal cord. Immunofluorescent examination revealed the presence of IgG in the fetal larynx, but there was little fluorescence for IgA, IgM and IgE. Secretory component (SC) synthesis, on the other hand, was found in each serous-type glandular epithelium or acinus from the fourth month on. Our observations suggest that the local immune system by SC, which binds to IgA as SIgA in human laryngeal mucosa, is inherently acquired in the fetal larynx.

Significance of airborne transmission of methicillin-resistant Staphylococcus aureus in an otolaryngology-head and neck surgery unit.

OBJECTIVES: To quantitatively investigate the existence of airborne methicillin-resistant Staphylococcus aureus (MRSA) in a hospital environment and to perform phenotyping and genotyping of MRSA isolates to study MRSA epidemiology. DESIGN: Prospective surveillance of patients with MRSA infections or colonizations was performed, as was an observational study of environmental airAirborne samples were taken by an air sampler; samples were obtained from object surfaces by stamping or swabbing. Epidemiological study of MRSA isolates was performed with an antibiotic susceptibility test, coagulase typing, and pulsed-field gel electrophoresis. SETTING: Three single-patient rooms in a 37-bed otolaryngology-head and neck surgery unit. PATIENTS: Three patients with squamous cell head and neck cancer were observed to have been colonized or infected with MRSA after surgery. RESULTS: The MRSA samples were collected from the air in single-patient rooms during both a period of rest and when bedsheets were being changed. Isolates of MRSA were detected in all stages (from stage 1 [>7 microm] to stage 6 [0.65-1.1 microm]). About 20% of the MRSA particles were within a respirable range of less than 4 microm. Methicillin-resistant S aureus was also isolated from inanimate environments, such as sinks, floors, and bedsheets, in the rooms of the patients with MRSA infections as well as from the patients' hands. An epidemiological study demonstrated that clinical isolates of MRSA in our ward were of one origin and that the isolates from the air and from inanimate environments were identical to the MRSA strains that caused infection or colonization in the inpatients. CONCLUSIONS: Methicillin-resistant S aureus was recirculated among the patients, the air, and the inamimate environments, especially when there was movement in the rooms. Airborne MRSA may play a role in MRSA colonization in the nasal cavity or in respiratory tract MRSA infections. Measures should be taken to prevent the spread of airborne MRSA to control nosocomial MRSA infection in hospitals.

Local immune system in human adult and fetal larynx.

Using immunofluorescent and histopathologic techniques, we studied the distribution and secretory activity of the glands of the larynx from 51 adults and 15 human fetuses. Glandular buds were first observed at the 12th fetal week and glandular distribution became evident from the 16th fetal week. In the adult larynx, intraepithelial and submucosal glandular distribution was observed in each specimen. Immunofluorescent studies revealed the diffuse fluorescence for IgA not only in the submucosal or periglandular connective tissue are but also in the intraepithelial and submucosal glands. Secretory component (SC) synthesis was found mainly in each serous-type glandular epithelium or acinus. In the submucosal or periglandular area, IgA-producing plasma cells were numerous. In contrast, there was little fluorescence for IgA in the fetal laryngeal tissues. Secretory component, however, was found in each serous-type glandular epithelium or acinus from the 16th week. Our observations suggest that local immune system by secretory IgA is active in the adult larynx, and the production of SC is inherently acquired in the fetal larynx.

Brain step tumor and otoneurologic manifestations: report of a case with autopsy.

The otoneurologic findings in a 30-year-old male patient who died of a brain stem tumor have been correlated with the histopathology of the temporal bones and brain. The patient was examined on two occasions. A sensorineural hearing loss, which was moderate in the right ear and mild in the left ear, was found. Abnormal vestibular function, indicative of central pathology, was also demonstrated. The right side of the medulla oblongata and pons was largely replaced by the tumor. The cochlear and vestibular nuclei and their connecting fibers were involved with the tumor. Histopathological changes were more prominent in the right cochlea and VII nerve than in the left and were minimal in the vestibular portion of the labyrinths. The otoneurological finding suggested a central nervous system (CNS) lesion, and the morphologic observations confirmed the central origin of the symptoms and signs. Manifestations of lesions of the central auditory and vestibular pathways are discussed.