Vertical fissure: computed tomographic observation and correlation with chest radiography.

PURPOSE: The purpose of this study was to assess radiographic and computed tomography (CT) findings of the vertical fissure. MATERIALS AND METHODS: We assessed whether the vertical fissures appeared as a fine linear shadow or as a linear edge with lateral opacity and medial lucency on chest radiographs. The CT scans were evaluated for the presence of volume loss in the lower lobes and for the presence of a portion of the fissure that is orientated tangential to the X-ray beam. RESULTS: We observed vertical fissures in six patients. CT studies revealed volume loss in the lower lobes in all patients and showed the presence of a portion of the fissure that is orientated tangential to the X-ray beam in only two patients whose vertical fissures were not associated with lateral opacity and medial lucency on chest radiographs. CONCLUSION: We believe that the vertical fissure is closely related to volume loss in the lower lobe and represents the edge of the anterobasal segment of a major fissure or a portion of the fissure that is orientated tangential to the X-ray beam, with or without lateral opacity and medial lucency.

Porous polystyrene microspheres having dimpled surface structures prepared within micellar assemblies of amphiphilic silica particles in water.

Production of porous polystyrene microspheres having dimpled surface structures was demonstrated using amphiphilic and hydrophobic silica particles as structure-directing agents.

Asymmetrically modified silica particles: a simple particulate surfactant for stabilization of oil droplets in water.

Spherical silica particles that are able to assemble at a phase boundary of a dual-phase mixture of water and an immiscible organic solvent were prepared by a partial modification of their surface hydroxyl groups with an alkylsilylation agent. Scanning electron microscopic observation of these particles in which their remaining surface hydroxyl groups had been selectively modified with colloidal gold particles revealed that each particle has an asymmetric surface structure: one side of the surface is hydrophilic and the other is hydrophobic. We found that these particles could form a micellar structure in water in the presence of an organic solution of a toluene/polystyrene mixture. The micellar structure was evidenced by formation of golf-ball-like polystyrene particles with dimples imprinting morphologies of the hydrophobic part of modified silica particles.

No high-mass protostars in the silhouette young stellar object M17-SO1.

The birth of very massive stars is not well understood, in contrast to the formation process of low-mass stars like our Sun. It is not even clear that massive stars can form as single entities; rather, they might form through the mergers of smaller ones born in tight groups. The recent claim of the discovery of a massive protostar in M17 (a nearby giant ionized region) forming through the same mechanism as low-mass stars has therefore generated considerable interest. Here we show that this protostar has an intermediate mass of only 2.5 to 8 solar masses (M(o), contrary to the earlier claim of 20M(o) (ref. 8). The surrounding circumstellar envelope contains only 0.09M(o) and a much more extended local molecular cloud has 4-9M(o).

[Signal processing and quality of displaying waveform at digital EEG machine].

With great advances in computer technology, the digital EEG machine was developed and has become widely used. In this paper, signal processing and quality of display of waveform at digital EEG machine were discussed to confirm its advantages and drawbacks. Signal processing on a digital EEG machine is summarized in 3 parts as follows: i) A/D conversion(sampling) of EEG signals in the head box, ii) Digital signal processing to obtain mathematically reconstructed EEG on the computer, iii) Displaying EEG on a monitor. For sampling, it was recommended that sampling rate was 200 or 256 Hz, and resolution in 12 bits or preferably 16 bits per sample. A high amplitude artifact caused EEG flattening called DC build up saturation. Montage reformatting had a clinical advantage. However, re-filtering using 15 Hz high cut filter influenced the EEG interpretation. The maximal resolution of digital EEG machine with a 17-inch CRT display using 1600 x 1200 dots was about 22 Hz. The performance of paper used for conventional EEG surpassed the performance of CRT display using digital EEG machine. It seemed that understanding the characteristics of digital EEG machine and realization of data processing were important for utilizing its functions effectively.

Cerebral oxygenation state in childhood moyamoya disease: a near-infrared spectroscopy study.

Near-infrared spectroscopy was used to measure the relative concentration changes of oxygenated hemoglobin (HbO(2)), deoxygenated hemoglobin (HbR), and total hemoglobin (t-Hb) before, during, and after hyperventilation in eight patients with childhood moyamoya disease who underwent surgery. The patients were divided into the following two groups: those with and those without re-build-up phenomenon on electroencephalography. All patients except one exhibited decreased concentrations of HbO(2) and t-Hb during hyperventilation and decreased concentrations of HbO(2) and increased concentrations of HbR after hyperventilation. The difference between the hemoglobin concentration during and after hyperventilation was significantly greater in the group with the re-build-up phenomenon than the group without it (P <0.03, Mann-Whitney U test). The patients with the re-build-up phenomenon had lower HbO(2) and higher HbR concentrations after hyperventilation. The concentrations of HbO(2) and HbR reflect an alteration in the oxygenated blood supply and/or oxygen use. Thus, it is strongly suggested that regional cerebral hypoxia and metabolic oxygen disturbances play an important role in the occurrence of the re-build-up phenomenon. Near-infrared spectroscopy is a useful noninvasive method to evaluate the efficacy of surgical treatment in childhood moyamoya disease.

[Postoperative electroencephalographic change in old patients with cardiac surgery].

The purpose of this study was to evaluate cerebral dysfunction in aged patients associated with cardiac surgery using quantitative electroencephalograph (QEEG). Seventeen consecutive patients undergoing cardiac surgery were investigated. There were nine males and eight females whose ages ranged from 65 to 77 years (mean 70.6 years). The cardiac procedures consisted primarily of coronary artery bypass (eleven patients) and valve replacement (six patients). They had good postoperative course, no complications were recognized. Each patient had an EEG examination using digital EEG equipment in first day before operation. Follow up investigations were repeated three times (first day, fifth day and one month after operation). QEEG analysis consisted of fast Fourier transform method was performed in each record. A fall in the peak frequency at basic rhythm was seen in 1st and 5th postoperative day. A power spectra corresponding to slow wave showed an increase at parieto-occipital area in 1st and 5th postoperative day. Alpha activity at occipital area was increased in one month after operation. The EEG change in first or fifth postoperative day suggested the patients had cerebral dysfunction without clinical findings.

[Auditory brainstem responses by click stimuli via an earphone--comparison with a headphone].

To evaluate the variations of auditory brainstem responses (ABR) recorded using different receivers, the recordings of ABR were performed in 10 neurologically and audiometrically normal subjects who were all females (20-21 years of age) using a headphone (DR-513B-6) and an earphone (YE-102J). The peak latencies, the interpeak latencies, and the amplitudes of wave I, III, and V at each ABRs were compared. Unilateral auditory stimuli consisted of alternate click with 0.1 msec duration at intensity of 110 dB SPL and at rate of 13 Hz was given to the subjects who lay in the supine position at awake state. The active electrode was placed on the vertex (Cz) and the reference electrode on the left or right mastoid. The responses recorded from Cz to the ipsilateral mastoid were amplified by a factor of 10 microV/DIV with a bandpass filter of 10 Hz-3 KHz, a total of 1000 responses was averaged. It was recognized that the output intensity via the earphone was lower than the headphone, the difference was approximately 5 dB. Furthermore, the frequency response of the earphone was worse than the headphone at high frequency area (over 3.5 KHz). There were characteristic differences between ABRs recorded using the headphone and the earphone. The prolongation of the latency and the decrease of the amplitude were identified at only wave I of ABRs recorded using the earphone. However, no significant changes were founded at another components.(ABSTRACT TRUNCATED AT 250 WORDS)

[Screening of sleep apnea syndrome using daytime polysomnography--its usefulness and the characteristics of daytime sleep in the patients with sleep apnea syndrome].

Some attempts have been made to screen sleep apnea syndrome (SAS). In this study, we performed daytime polysomnography (DPSG) as a means of screening SAS. 33 patients (28 males and 5 females, a mean age of 50.7 years) who were seen with the complaints of sleep-wake disorders, snoring and breathing disturbance in their nocturnal sleep were subjects for the screening. EEG, EMG, and EOG according to standard polysomnographic technique were recorded from 3:30 (p.m.) for 60 minutes, as additional indicators, oro-nasal airflow and abdominal movement were monitored simultaneously to confirm cessation of breathing. After the screening, we performed conventional polysomnography (PSG) to make a diagnosis of SAS, and compared the diagnosis with the appearance of apnea in the screening. We studied on the characteristics of daytime sleep in SAS and NonSAS by the comparison of EEG variables obtained from DPSG. Sleep apnea was detected in 20 cases with DPSG, 18 cases of these 20 were diagnosed as SAS. However, there were 6 patients who were diagnosed as SAS without the appearance of apnea in the screening. Dominant type of apnea in the screening were corresponded to ones confirmed with PSG, 16 cases showed obstructive type and 4 cases indicated central type. Some statistical differences of EEG variables between SAS and NonSAS were recognized. Number of stage shifts and percentage of stage W to total sleep time were significantly increased in SAS, on the contrary, percentage of stage 2 to total sleep time tended to be lower in SAS.(ABSTRACT TRUNCATED AT 250 WORDS)

Iron in cicatrix and abnormal CT findings in a patient with posttraumatic epilepsy.

A 33-year-old male patient showed increasing frequency of seizures 12 years after a blunt head injury. From findings of x-ray computed tomography, the lesion was thought to be a benign glioma. Removal of the lesion was performed with the guidance of electrocorticography. Histological diagnosis was gliotic scar with calcification. Diffuse iron particles were detected in layers II-V of the cortex by hematoxylin and Berlin-Blue stain. These findings suggest progressing traumatic epilepsy which may be explained by the mechanism of Willmore's model.

Aplasia of the Optic Nerve in Microphthalmic Offspring of Prenatally X-irradiated Rats.

A considerable number of postnatally-viable microphthalmic offspring with optic nerves completely absent were obtained by X-irradiation at a dose of 100 R in pregnant rats on gestational day 10.5. Thirteen of 15 mi-crophthalmic eyes examined displayed histological features characteristic of aplasia of the optic nerve: complete absence of optic papilla, nerve fiber layer and retinal blood vessels, and great reduction in the number of ganglion cells. The remaining 2 eyes showed the histological features of hypoplasia of the optic nerve. The present experimental system may afford suitable materials for postnatal patho-genetic studies and also for various physiological and behavioral studies of aplasia of the optic nerve.

Intercellular Contacts Between the Embryonic or Extraembryonic Ectoderm and the Primitive Endoderm in Rat Egg Cylinders Prior to the Formation of Primitive Streak.

In pre-primitive streak-stage rat egg cylinders, both the embryonic and extraembryonic ectodermal cells projected cytoplasmic protrusions through gaps in the basal lamina and formed intimate cell-to-cell contact with the primitive endodermal cells. The 70 Å microfilaments were considered to participate in the production of these cytoplasmic protrusions. However, direct cell contact mediated by adherent junctions was occasionally found between the embryonic or extraembryonic ectodermal cells and the primitive endodermal cells. It has been proposed that these cell-to-cell contacts may play a role either in the supporting effect of primitive endodermal cells in the maintenance of cellular organization of the ectodermal cells, or in the facilitation of transport of nutritive materials from the primitive endodermal cells to both types of ectodermal cells.

Persistent Nucleoli in Early Postimplantation of Rat Embryos.

Ultrastructural changes of the nucleolus in mitotic embryonic ectodermal cells of 7 1/2-day and 7 2/3-day rat embryos were examined. It was found that the nucleolus was broken down into small fragments during late prophase and metaphase, and that some of these fragments persisted in the cytoplasm of telophase cell (persistent nucleoli). No interphase embryonic ectodermal cells contained persistent nucleoli. Persistent nucleoli were also found in telophase cells of extraembryonic ectoderm, extraembryonic visceral endoderm and parietal endoderm of the embryos, but they disappeared in interphase cells. Persistent nucleoli in telophase cells tended to decrease in size with embryonic age, and they had almost completely disappeared in neuroectodermal cells of the telencephalon in 14 1/2-day embryos. They were concluded to be remnants of disappearing nucleoli in embryonic cells that were cycling too rapidly to permit their nucleoli to disappear completely.

ULTRASTRUCTURAL CHANGES IN EMBRYONIC ECTODERMAL CELLS OF THE NEURULATING RAT EMBRYO.

Embryonic ectodermal cells of rat embryos were examined by light and electron microscopy during the early stage of neurulation. Before the onset of neurulation (day 9-6 hr embryos), the cells underwent certain characteristic ultrastructural changes; that is, apical cytoplasmic protrusions and free spherules appeared, numerous vacuoles were formed in the cytoplasm, mitochondria showed ballooning, and the endoplasmic reticulum became dilated. The amniotic cells derived from the embryonic ectoderm exhibited the same ultrastructural changes, but those from the extraembryonic mesoderm did not. Embryonic mesodermal cells and neuroectodermal cells also did not show these changes. In the middle stage of neurulation (day 9-12 hr embryos), the embryonic ectodermal cells and the amniotic cells derived from the embryonic ectoderm assumed a flat squamous shape. None of the ultrastructural changes observed in day 9-6 hr embryos were noted in these cells. The functional significance of the production of apical cytoplasmic protrusions and free spherules in the embryonic ectodermal cells and amniotic cells is discussed in relation to similar phenomena reported to occur in other cell types.