Pilomatrix carcinoma of the axilla: CT and MRI features.

Pilomatrix carcinoma, a rare malignant soft tissue tumour, is the malignant variant of pilomatricoma. We report a case of pilomatrix carcinoma of the axilla. CT demonstrated a well-circumscribed, sand-like calcified mass. MRI showed diffusely inhomogeneous, mixed signal intensities with inhomogeneous enhancements. The MRI findings were different from those previously reported for pilomatricoma.

Predictive value of serum immunosuppressive acidic protein for lung metastasis after amputation of murine osteosarcoma of the lower limb.

A spontaneously occurring murine osteosarcoma cell line (POS-1) was inoculated into the footpads of 88 mice. In 59 mice, the tumor-bearing leg was amputated at 1, 3, 5, or 7 weeks after inoculation and the mice sacrificed at 9 weeks. Lung metastasis was observed in 82.6-100% of the mice undergoing leg amputation at 5 or 7 weeks after inoculation. There were no lung metastasis in the mice amputated at 1 or 3 weeks. The serum immunosuppressive acidic protein (IAP) concentration showed a significant increase at 5 or 7 weeks after inoculation (P<0.005 and P<0.0005, respectively). When amputation was done 5 weeks after inoculation, the serum IAP concentration increased further to 5.9 times the pre-amputation level 1 week after the amputation. The IAP concentration increased only 1.3-fold in the control group without inoculation. Thus, a high serum IAP concentration before amputation and a further increase after amputation were indicators of lung metastasis in this mouse model of osteosarcoma.

Automatic auditory information processing in sleep.

STUDY OBJECTIVES: The mismatch negativity (MMN) component of the event-related potentials reflects the automatic detection of sound change. Only a few researchers have investigated the MMN elicitation during sleep in adult human and some of them reported that MMN amplitude was decreased in sleep compared to in waking. However, it is not clear that the decrease of MMN amplitude was due to increased drowsiness or long-term response decrement. Two experiments were conducted to clarify whether or not the MMN was elicited in each sleep stage. We presented auditory stimuli to subjects continuously from waking until sleep state (Experiment 1). Using the same experimental condition, we examined whether or not MMN amplitude was influenced by long-term stimulus presentation (80min.) and by vigilance level (Experiment 2). DESIGN: N/A SETTING: N/A PARTICIPANTS: N/A INTERVENTIONS: N/A MEASUREMENTS & RESULTS: Experiment 1: MMN was obtained in both drowsiness and REM sleep. MMN was significantly smaller in amplitude and shorter in latency in the both stages than in the waking state. However, MMN was not found in another sleep stage. Experiment 2: Amplitudes were no different among 0-20 min., 20-40 min., 60-80 min. But it was decreased in 40-60 min. and power value of alpha-wave was decreased in 40-60 min. CONCLUSIONS: To obtain the reliable data, by using the automatic spectral analysis, we confirmed that MMN was elicited in REM sleep. MMN was not influenced by long-term stimulation. The result suggested that auditory stimuli could be processed in the pre-attentive sensory memory even in REM sleep.

Somatosensory automatic responses to deviant stimuli.

We studied event-related potentials (ERPs) produced in response to deviant stimuli in a sequence of somatosensory stimuli which were measured under stimulus-ignoring conditions. A change in the repetitive somatosensory input elicited not only a frontal negativity which was similar to the somatosensory mismatch negativity very recently reported by Kekoni et al. [J. Kekoni, H. Hämäläinen, M. Saarinen, J. Gröhn, K. Reinikainen, A. Lehtokoski, R. Näätänen, Rate effect and mismatch responses in the somatosensory system: ERP-recordings in humans, Biol. Psychol. 46 (1997) 125-142] but also a positive deflection ranging in latency from 100 to 200 ms. This somatosensory change-related positivity was reduced with prolongation of the interstimulus interval (ISI) and was different from the responses to the deviant stimuli when they were presented alone. These findings suggest that the somatosensory change-related positivity is probably generated not by activation of new afferent elements but by a detection of change in a process of comparison with sensory memory.

The effect of deviant stimulus probability on the human mismatch process.

The present study addresses the separate activities of frontal and temporal MMN generators which might be differentially affected by a change in the probability of standard stimuli. As the probability of standard stimuli was increased, the frontal MMN component significantly increased in amplitude, while the temporal one was not affected. Correspondingly, the scalp current density (SCD) maps showed that the temporal MMN generator was activated even at low probability of standard stimuli, suggesting that even the weak memory trace could start the automatic mismatch process, whereas the frontal MMN generator was activated only with increased probabilities of standard stimuli, suggesting that the stronger the memory trace is, the easier it might trigger the involuntary switching of attention to stimulus change.

Mismatch negativity (MMN) reveals sound grouping in the human brain.

To investigate a part of the structure of the memory trace, auditory event-related potentials (ERPs) were recorded from reading subjects while they were presented with two different stimulus-series simultaneously. A clear mismatch negativity (MMN) was obtained from each series, when the stimulus sequence consisted of a high-frequency series and a low-frequency series. Moreover, the MMN showed independent elicitation within each series. However, if the frequency range of one series overlapped with that of the other series, the amplitude of the MMN was prominently reduced, suggesting that the two processing functions indexed by MMN coexisted simultaneously in the preattentive acoustic system and were produced by the respective grouping of high-frequency tones and low-frequency tones.

Organizing sound sequences in the human brain: the interplay of auditory streaming and temporal integration.

The present study examined the relationship between two of the early brain processes of sound organization: auditory streaming and the temporal window of integration (TWI). Presented at a fast stimulus delivery rate, two tones alternating in frequency are perceived as separate streams of high and low sounds. However, when two sounds are presented within a ca. 200 ms temporal window, they are often processed as a single auditory event. Both stream segregation and temporal integration occur even in the absence of focused attention as was shown by their effect on the mismatch negativity (MMN) event-related potential. The goal of the present study was to determine the precedence between these two sound organization processes by using the stimulus-omission MMN paradigm. Infrequently omitting one stimulus from a homogeneous tone sequence only elicits an MMN when the stimulus onset asynchrony separating successive tones is shorter than 170 ms. This demonstrates the effect of the TWI. Magnetic brain responses elicited by infrequent stimulus omissions appearing in a sequence of two alternating tones were recorded. The magnetic MMN was elicited by tone omission when the alternating tones formed a single stream (with no or only small frequency separation between the two tones) but not when separate high and low streams emerged in perception (large frequency separation between the two alternating tones). This result shows that auditory streaming takes precedence over the processes of temporal integration.

Suppressive effects of F-1322 on the antigen-induced late asthmatic response and pulmonary eosinophilia in guinea pigs.

We investigated the effects of F-1322 (N-[2-[4-(benzhydryloxy)piperidino]ethyl]-3-hydroxy-5-(3-pyridylmethoxy)-2-naphthamide), a new compound that inhibits both thromboxane A2 synthetase and 5-lipoxygenase and that functions as a histamine antagonist, on the Ascaris antigen-induced late asthmatic response and pulmonary eosinophilia in guinea pigs. Oral administration of F-1322 (10-100 mg/kg) inhibited the antigen-induced late asthmatic response in a dose-dependent manner. Histological analysis revealed that F-1322 prevented the accumulation of eosinophils in the airways and this was paralleled by a decrease in the number of eosinophils and lymphocytes recovered in bronchoalveolar lavage fluid. F-1322 (0.1-10 microM) inhibited eotaxin-induced chemotaxis and actin polymerization of eosinophils in vitro in a concentration-dependent manner, while oral administration of F-1322 dose-dependently suppressed the migration of eosinophils into the airways in vivo in response to infusion of interleukin 5 and eotaxin in combination. F-1322 may, thus, improve the late asthmatic response in this model, in part, by preventing the accumulation of eosinophils in the airways. The pharmacological profile of F-1322 indicates that this drug is likely to be useful in the treatment of allergic diseases such as asthma.

Event-related desynchronization during an auditory oddball task.

OBJECTIVE: The present study addressed what kind of mental processes would be presented by the event-related desynchronization (ERD) relevant to the stimuli of an auditory oddball count task. METHODS: Electroencephalogram (EEG) was recorded from nine healthy subjects while target tones (2000 Hz, P = 0.2) and non-target tones (1000 Hz, P = 0.8) were presented randomly with constant stimulus onset asynchrony (SOA) of 3.3 s. To improve time resolution of ERD analysis, obtained EEG epochs were digitally convoluted by Gabor wavelet and averaged respectively. RESULTS: For target stimulus, prominent ERD was observed in left parieto-occipital areas (peak latency: 400-600 ms), but there were no significant ERD for non-target stimulus. CONCLUSION: Our result suggests that magnitude of ERD would reflect amount of mental effort which was associated with intentional and voluntary processes rather than automatically sensory process.

Time integrated spectroscopy of turbid media based on the microscopic beer-lambert law: application to small-size phantoms having different boundary conditions.

Continued work on time-integrated spectroscopy (TIS) is presented to quantify absorber concentrations in turbid media. We investigated the applicability of the TIS method to small-size media that have different boundary conditions by measuring two 20×20×50 mm3 cuboid liquid tissue-like phantoms at various absorption levels (absorption coefficients of the phantom from 2.5×10-3 to 4.4×10-2 mm-1 at 782 nm and from 3.1×10-3 to 2.7×10-2 mm-1 at 831 nm). The scattering and absorbing solution was filled into ordinary and black-anodized aluminum containers to provide different boundary conditions. By means of a single equation, the absorber concentrations have been recovered within errors of a few percent in both cases. This demonstrates that the TIS method can quantify absorbers in small-size media having different boundary conditions. © 1999 Society of Photo-Optical Instrumentation Engineers.

Formation of the ocular arteries in the chick embryo: observations of corrosion casts by scanning electron microscopy.

An investigation was carried out on the formation of the blood vessels that supply the optic cup or eyeball in developing chick embryos ranging in age from Hamburger-Hamilton stage 17 (st17) to st44. Corrosion casts of the vasculature were made by injecting resin and examined by scanning electron microscopy. The optic cup was supplied by branches of the cranial ramus of the circle of Willis (CCW) from st17 to st19. By st23, a branch of the CCW and that of the internal carotid artery became anlagen of two ophthalmic arteries, namely, the cerebral ophthalmic artery (COA) and the internal carotid ophthalmic artery (ICOA) respectively. They were continued by primordia of the long posterior ciliary arteries, which connected with each other to form a ring around the pupil. Between st19 and st26, another branch of the CCW was found, by contrast, to supply the primitive pecten. The distal part of the nasal long posterior ciliary artery began to atrophy at st28, so the temporal long posterior ciliary artery only began to supply the ring artery around the pupil by st30. At the same time, the artery supplying the pecten became anastomosed with the ICOA behind the eyeball to form the definitive pectinate artery. By st30, the ophthalmic branch of the stapedial artery had also formed and connected with the distal part of the ICOA behind the eyeball, as well as with the distal part of the COA by st34. The supraorbital branch of the stapedial artery, which had replaced the CCW to anastomose with the ethmoidal artery by st30, was found to be connected to the COA at st36. The main vascular system supplying the eyeball was complete at st36, and its structure at st40 and st44 was fundamentally similar to that at st36.

Scanning electron microscopic study on the development of primitive blood vessels in chick embryos at the early somite-stage.

Primary vasculogenesis in chick embryos at the early somite stage (1-14 somites) was investigated mainly by scanning electron microscopy (SEM), with special reference to the development of primitive blood vessels such as the arteria et vena vitellina (AV, VV), aorta dorsalis (AD) and vena cardinalis (VC). After glutaraldehyde fixation, the endoderm or ectoderm was removed from the embryos to expose either the ventral (AV, VV, AD) or the dorsal (VC), vascular system. The mode of vascular formation was found to be identical in all these blood vessels, arising first in loco as isolated solid masses or cords composed of so-called angioblasts. The angioblasts at this developmental phase could be distinguished from underlying mesenchymal cells, exhibiting a relatively flat surface. The VV was recognized first on both sides of the anterior intestinal portal at the 4-somite stage, whereas the forming AD was identified on the ventral surface of the paired somites at the 6-somite stage, appearing almost simultaneously from the cranial to caudal somite regions. After the 8-somite stage, the AV was formed by transformation of one of the caudal plexuses spreading to the area vasculosa. In the 9-somite stage, the angioblastic cords of the VC appeared on the dorsal side of the mesoderm in the same manner as for other ventral vessels. This finding differs from the statement of a previous author that the VCis formed by longitudinal anastomosis of intersegmental diverticula of the AD.

TEM-studies on development and canalization of the dorsal aorta in the chick embryo.

Transmission electron microscopic investigations were carried out on the early development of the dorsal aorta in chick embryos during the period ranging from the 6-somite stage to the 16-somite stage. Special attention was paid to the formation of the vascular lumen. The initial angioblasts tended to aggregate into a cluster with a narrow intercellular space. Only a few punctate thickenings of the plasma membrane were found at junctional sites of the angioblasts. The vascular cavity appeared to be produced by expansion of the intercellular space and possibly also by enclosure of the extracellular space with attenuated vasoformative cells. The wall of the early vessels so formed was frequently observed to be open to the extravascular space through clefts originating probably from incomplete closure of the early endothelium. No specific ultrastructural features characterizing the angioblasts or early endothelial cells were recognized.

Formation of the pharyngeal arch arteries in the chick embryo. Observations of corrosion casts by scanning electron microscopy.

An investigation was made of the formation of the pharyngeal arch arteries (PAAs) in developing chick embryos that ranged from Hamburger-Hamilton stage (st) 12 to st44 and 1-day-old chicks after hatching. Corrosion casts of the vasculature were made by injecting resin and examined by scanning electron microscopy. The relationship between the PAAs and associated organs was then demonstrated by computer-aided reconstruction. The ventral aorta connected with the dorsal aorta through a loop in front of the foregut at st12. We named this loop the primitive aortic arch to distinguish it from the true first PAA. The second PAA was found to form at st14 and the third PAA at st15, while the true first PAA to connect the dorsal and ventral aortae was found at st16. The aortic regions anterior to the first PAA then fused. By st19, the first PAA had disappeared and the fourth PAA had appeared. The fifth and sixth PAA were observed as a capillary plexus at st20 and st21. The fifth PAA consisted of a bypass of the sixth PAA during st22 to st25. The second PAA was observed to be very slender at st23 and to rupture by st25. At the same time, the proximal parts of the first and second PAAs and the ventral aorta changed into the primary external carotid artery (ECA) and gave off branches to the upper and lower jaws. Furthermore, the distal part of the second PAA remained to become the two branches of the dorsal aorta giving rise to the stapedial artery and the root of the secondary ECA.(ABSTRACT TRUNCATED AT 250 WORDS)

Calcium-containing vacuolated mitochondria during early heart development in chick embryos as demonstrated by cytochemistry and X-ray microanalysis.

The ultrastructure of mitochondria in the developing heart was examined in chick embryos from 2 to 7 days after fertilization. Vacuolated mitochondria were observed in the heart muscle cells of embryos at all stages examined. The number of vacuolated mitochondria as a percentage of total mitochondria in muscle cells was high in embryos at 3 and 4 days and was much higher in the ventricular cells than in the atrial cells. Examination by cytochemistry and X-ray microanalysis revealed the accumulation of calcium in the vacuoles of mitochondria. These results suggest important roles for vacuolated mitochondria in the regulation of the intracellular concentration of calcium during the early development of the chick heart.

An ultrastructural topographical study on myofibrillogenesis in the heart of the chick embryo during pulsation onset period.

Ultrathin sections of the chick embryonic heart at the 8-, 9- and 10-somite stage were cut serially at an interval of 20 micron and mounted for transmission electron microscopic examination on a copper grid with a sufficiently large hole to survey the entire section area. The grid was supported by a formvar film. Thick filaments were first found to assemble into well-defined bundles in several cells composing the caudal region of the newly formed heart just before onset of the pulsation at the 8-somite stage. Then, at the 9-somite stage when pulsation commences, the cells possessing nascent myofibril(s) increase in number, slightly more in the right side of ventricular region. At the 10-somite stage, the rhythmical contraction is established and striated myofibrils become distinctly discernible. Right side dominance is more conspicuous at this stage than previously. Then, myofibrillogenesis gradually progresses toward the cranial or bulbar region.

Establishment of two rat osteosarcoma cell lines (YROS-1 and YROS-2) induced by radioactive phosphorus.

Two rat osteosarcoma cell lines, YROS-1 and YROS-2, were established from two experimental osteosarcomas and induced by internal irradiation with radioactive phosphorus. Both cell lines formed a monolayer cell sheet in vitro with focal piling. The YROS-1 cells were refractile and spindle or polygonal in shape, whereas the YROS-2 cells were flat, spread and polygonal in shape. Ultrastructurally, the YROS-1 cells had well-developed rough-surfaced endoplasmic reticulum with focal pericellular deposition of calcified matrix, whereas YROS-2 had abundant polysomes and intracytoplasmic filaments. Both cell lines grew stably with population doubling times of 23 and 39 h, respectively. Flow cytometry revealed that YROS-1 was rich in proliferating cells compared to YROS-2, with a higher colony-forming efficiency. YROS-1 showed high alkaline phosphatase activity, while YROS-2 possessed low activity. When subcutaneously transplanted into lumbodorsal area of athymic nude mice, only YROS-1 formed tumors with frequent lung metastasis.

Development of Dunn osteosarcoma inoculated into subcutaneous air pouch in mice.

Dunn osteosarcoma cell growth was observed in C3H/Hej mouse subcutaneous air pouch. Inoculation with Dunn osteosarcoma cell suspension was performed by injection into air pouches of 70 mice on Day 7 after the initial injection of air. The developmental pattern of the tumor cell colonies was classified histologically into five stages. In Stage 0 (stage of no tumor cells), there were no tumor cells. In Stage 1 (focal stage), the colonies were limited to the lining-cell layers. In Stage 2, (segmental stage) the colonies protruded into the cavity of the pouch. In Stage 3 (annular stage), the total surface of the inner wall of the pouch was occupied by tumor cells. In Stage 4 (occlusive stage), the cavity of the pouch was fully occupied by tumor cells. The tumor was observed to develop to stage 1 in all mice 7 days after inoculation. The colonies were all found to be settled initially in the deeper layer of lining cells. Thus, the mouse air-pouch model is useful for direct observation of osteosarcoma cell growth.

Histogenesis of tunica media of the chick aorta.

We investigated the formation of the aortic tunica media in developing chicks from Hamburger-Hamilton stage (st) 12 to 1-day after hatching. At st 12, some cells of the lateral plate and the somite adjacent to the aorta extended processes toward the aortic endothelial tube. This is the first sign of the tunica media formation of the aorta. Then, these cells detached from the lateral plate and the somite attached to the aortic endothelial tube and covered it almost entirely by st 18. At this stage, bundles of microfilaments and spots of dense material were found in the peripheral region of cells of the tunica media (media cells); suggesting the earliest differentiation of smooth muscle cells. Subsequently, the tunica media increased in the number of cell-layers, reaching approximately 20 layers at st 34 (8-day incubation). The outer layers of the tunica media consisted of undifferentiated cells, whereas typical smooth muscle cells were found within the inner 4 to 5 layers. Elastic fibers first appeared at this st 34. With there was an increase in the elastic component, the tunica media assumed the lamella structure consisting of the alternating myocytes and elastic laminae. The aortic media 1-day after hatching essentially exhibited the same mature state as seen in the adult chickens.