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T Mashiko

Publications and source records attributed to T Mashiko.

At least 37 records · Page 2Linked to original sources
PubMed1998

[Concentrations of free form and complex form of prostate-specific antigen in serum of alpha 2 macroglobulin deficient patients with prostatic carcinoma].

Prostate-specific antigen (PSA) is present in blood in free form as well as in complex form with various protease inhibitors such as alpha 2 macroglobulin (alpha 2M) and alpha 1 antichymotrypsin (alpha 1 ACT). We had found that alpha 2M is deficient (below approximately 40 mg/dl) in some patients with prostatic carcinoma. Therefore, we investigated the levels of free and complex form of PSA in patients with prostatic disease and obtained the following results. The HPLC study showed that total (free plus complex) PSA level was much higher in the alpha 2M deficient patients with prostatic carcinoma stage D (n = 7, range 1,530-14,746 ng/ml, median value 6,800 ng/ml) than in the non-deficient patients with stage D (n = 16, range 121.6-4,210 ng/ml, median value 851 ng/ml). In the deficient patients, the complex of PSA with alpha 1 ACT increased extraordinarily while free PSA increased to only some extent. In the more severe cases of prostatic carcinoma, the ratio (complex/total PSA) was higher while the ratio (free/total PSA) was lower. The SDS-PAGE Western blotting showed that complex PSA increased extraordinarily and free PSA increased in sera of the deficient patients which was consistent with the HPLC results. Many bands appeared on the blotting at the positions smaller than alpha 2M molecule, which indicated that many fragments of alpha 2M were present in their sera. These bands were more intense than the bands with sera of controls or benign prostatic hypertrophy. The alpha 2M deficiency may be due to the rapid disappearance of the complex with PSA or any other prostate-originated proteases. The complex may undergo accelerated degradation or catabolism of alpha 2M.

Aged↗
PubMed1998

[Quantitative levels of serum amyloid A protein and other proteins in cerebrospinal fluid and serum of patients with meningitis].

Serum amyloid A protein (SAA), a putative precursor of the AA protein which constitutes amyloid fibrils in secondary amyloidosis, is evaluated as a sensitive acute-phase reactant in serum. At present, SAA concentration in serum is determined by latex nephelometry, but this assay cannot detect SAA in the low concentration range lower than 10 ng/ml. We have developed a sensitive enzyme immunoassay (EIA) for determining low concentrations of SAA. The assay is reproducible, reliable and requires no pretreatment of specimen prior to assay. We measured levels of SAA by this EIA in both cerebrospinal fluid (CSF) and serum of patients with suspected meningitis, measured also levels of albumin, alpha 2 macroglobulin and C-reactive protein (CRP) to investigate if these protein levels are useful for differential diagnoses of meningitis and for indicators damage of blood-CSF barrier. The SAA reference value in CSF is 3.99 +/- 1.74 ng/ml (mean +/- SD for nonmeningitis patients). The CRP concentration in CSF in bacterial meningitis was much higher than in viral meningitis, but CRP in CSF was also high in bacterial infection other than meningitis. On the other hand, SAA concentration in CSF in these patients with any meningitis are significantly higher than the reference values of SAA (p < 0.001). However, the differences in SAA concentrations among the three types (bacterial, viral and mycotic meningitis) of meningitis were not significant.

Acute-Phase Proteins↗
PubMed1997

The silent period between sounds has a stronger effect than the interstimulus interval on auditory evoked magnetic fields.

Auditory evoked cortical responses, electric. N1 and magnetic N1m, increase when the interstimulus interval (ISI) increases. We assumed that the response to a tone is mainly affected by the immediately preceding ISI, by the immediately preceding pause between stimuli (PBS) and by the previous stimulus duration (PSD). These 3 values are connected by the following expression: ISI = PBS + PSD. We examined the dependence of the auditory evoked brain magnetic responses on the ISI with the constant PSD (conventional paradigm), on the PBS with the constant ISI, and on the ISI with the constant PBS. Peak latencies and peak amplitudes of the 3 components, P1m, N1m and P2m, are recorded in one block using all possible combinations of 5 PSDs (0.05, 0.5, 1.0, 1.5 and 2.0 s) and 5 ISIs (0.5, 1.0, 1.5, 2.0 and 2.5 s). Peak latencies of these 3 components do not show any significant dependence either on the PBS or on the ISI. Neither the PBS nor the ISI brings a statistically significant effect on the P1m peak amplitude. On the other hand, the N1m peak amplitude increases as either the PBS (constant ISI) or the ISI (constant PSD) increases. The regression coefficient to the PBS is more than a double of that to the ISI. Moreover, the ISI does not show any significant effect on the N1m peak amplitude when the PBS is constant. This stronger PBS effect means that the N1m peak amplitude dependence on the ISI, which has been reported in several papers using the constant PSDs, includes more dependence on the PBS. The P2m peak amplitude shows the same tendency as the N1m because of the strong correlation in peak amplitude between them.

Adult↗
PubMed1996

Discrepancy between brain magnetic fields elicited by pattern and luminance stimulations in the fovea: adequate stimulus positions and a measure of discrepancy.

A conventional equivalent current dipole estimation provides one of the quantitative measures to evaluate the discrepancy between two single-dipole-like magnetic field patterns, though there is one problem; all stimulus positions in the visual field do not necessarily contribute to the generation of a single-dipole-like magnetic field. Another important problem occurs when the field pattern is complex and cannot be approximated by a dipole. This makes it difficult to evaluate the discrepancy between two magnetic field patterns by the dipole parameters. In this paper, we determined the stimulus positions adequate for generating single-dipole-like magnetic field patterns by evaluating the magnetic field's goodness-of-fit to the field generated by a single dipole. We propose to use a similarity (SIM) as a quantitative measure of the discrepancy between two complex magnetic field patterns. The SIM is defined as an angle between two magnetic field vectors. We evaluated the discrepancy between the 100 ms post-stimulus responses to pattern-reversal (Rv) stimulus, pattern-onset (Pat) stimulus, and luminance-onset (Lumi) stimulus. The following results were obtained: (1) Stimulation of some of the octants in the fovea, far from the vertical meridian, elicited a single-dipole-like magnetic field pattern at a latency of 100 ms, though stimulation of the central part of the fovea, and stimulation of the octants along the vertical meridian, did not elicit a single-dipole-like magnetic field pattern; (2) The discrepancy between responses was quantitatively evaluated by the SIM even if the field patterns were complex; (3) The SIM analysis showed that the discrepancy between the responses to the Rv and the Lumi stimuli, as well as that between the responses to the Pat and the Lumi stimuli, were greater than that between the responses to the Rv and the Pat stimuli.

Adult↗
PubMed1996

Somatic evoked high-frequency magnetic oscillations reflect activity of inhibitory interneurons in the human somatosensory cortex.

High-frequency potential oscillations in the range of 300-900 Hz have recently been shown to concur with the primary response (N20) of the somatosensory cortex in awake humans. However, the physiological mechanisms of the high-frequency oscillations remained undetermined. We addressed the issue by analyzing magnetic fields during wakefulness and sleep over the left hemisphere to right median nerve stimulation with a wide bandpass (0.1-2000 Hz) recording with subsequent high-pass (> 300 Hz) and low-pass (< 300 Hz) filtering. With wide bandpass recordings, high-frequency magnetic oscillations with the main signal energy at 580-780 Hz were superimposed on the N20m during wakefulness. Isofield mapping at each peak of the high-pass filtered and isolated high-frequency oscillations showed a dipolar pattern and the estimated source for these peaks was the primary somatosensory cortex (area 3b) very close to that for the N20m peak. During sleep, the high-frequency oscillations showed dramatic diminution in amplitude while the N20m amplitude exhibited a moderate increment. This reciprocal relation between the high-frequency oscillations and the N20m during a wake-sleep cycle suggests that they represent different generator substrates. We speculate that the high-frequency oscillations represent a localized activity of the GABAergic inhibitory interneurons of layer 4, which have been shown in animal experiments to respond monosynaptically to thalamo-cortical input with a high-frequency (600-900 Hz) burst of short duration spikes. On the other hand, the underlying N20m represents activity of pyramidal neurons which receive monosynaptic excitatory input from the thalamus as well as a feed-forward inhibition from the interneurons.

Adult↗
PubMed1996

[Report of a case of intraosseous meningioma: a review of the literature and diagnostic value using MRI study].

A 40-year-old woman with intraosseous meningioma is reported. She was admitted because of a slowly growing, bony hard, fixed mass in the temporal area that was covered by the normal scalp. The neurological examination on admission was negative. Plain skull radiogram demonstrated an area of hyperostotic change in the temporal region. Bone-targeted CT demonstrated irregularity in the structure of the skull bone. Selective external carotid angiogram showed a homogeneous tumor stain in the region of the skull thickening. Macroscopically complete tumor resection (Simpson's grade 1) was carried out. Her postoperative course was uneventful. The skull tumor had the typical feature of meningotheliomatous meningioma. MRI showed a mass lesion of the temporal bone on T1- and T2-weighted images, and a well-enhanced mass lesion of the outer dura and outer table of the skull bone on Gd-DTPA enhanced T1 images. The findings of the preoperative MRI study using Gd-DTPA were identical with the tumor area on histological study. Therefore, MRI with Gd-DTPA enhancement was considered a useful diagnostic modality.

Adult↗
PubMed1995

Neuromagnetic measurements of the human primary auditory response.

The spatio-temporal organization of the human primary auditory response (N19 and P30) was determined by analyzing magnetic fields from the right hemisphere evoked by monaural clicks to the left ear. The magnetic response consisted of peaks corresponding to electrical N19 (N19m) and P30 (P30m) within 40 msec after stimulation. However, the onset of electrical N19 occurred 5-9 msec earlier than that of the magnetic counterpart. Furthermore, the relative amplitude of N19 and P30 (N19/P30) was larger (more than 1) than that (about 0.5) of N19m and P30m (N19m/P30m). The findings suggest an additional contribution from a subcortical source for electrical N19. The estimated equivalent sources for N19m and P30m were localized at the postero-medial part of Heschl's gyrus (the primary auditory cortex). Furthermore, the dipole orientation of N19m was directed postero-ventrally and that of P30m was in the opposite direction, which is compatible with the anatomy of the supratemporal primary auditory cortex. These results resolve a long standing controversy of cortical vs. subcortical structures as the generators of the N19.

Auditory Cortex↗
PubMed1995

Multichannel detection of magnetic compound action fields with stimulation of the index and little fingers.

Magnetic compound action fields (CAFs) over the right arm were measured from 63 sensor positions with two 7-channel SQUID gradiometer systems following electrical stimulation of the index and little fingers as well as the ring finger separately. The wave forms of the CAFs were primarily biphasic, corresponding to the depolarization and repolarization currents of the stimulated nerves. Maximum amplitudes of the CAFs were 60-140 fT for the index finger stimulation and 40-90 fT for the little finger stimulation. The field mapping of the CAFs revealed a propagating quadrupolar pattern with different distributions for the index and little fingers. The results agree with the anatomical location of the median and ulnar nerves for the index and little finger stimulation respectively. The isofield maps, due to ring finger stimulation, showed complex patterns as a result of simultaneous activation of the median and ulnar nerves. By comparing the amplitudes of the maxima of the CAFs due to index finger stimulation with those after median nerve stimulation at the wrist, the numerical ratios of the constituent digital nerve fibers for the index finger within the median nerve at the wrist were estimated. The ratios of 0.14-0.41 (mean 0.27), determined with measurement of the CAFs, are fairly consistent with those calculated from the reported histological data.

Adult↗
PubMed1994

Developing rat pineal cells manifest potential of neuronal differentiation in vitro.

The pineal gland in mammals is an endocrine organ and generally does not exhibit neuronal characteristics. However, it is known that under culture conditions, cells from newborn rat pineals express properties characteristic of photoreceptors. Here, we studied the potential of rat pineal cells to differentiate into neuronal cell types using different neural markers. Three phenotype markers characteristic of nerve cells, i.e., intense GABA, neuron-specific antigen (HPC-1) and microtubule-associated protein 2 (MAP2) immunoreactivities, were detected in the pineal culture of newborn rats. Expression of the respective neuronal phenotypes appears to be controlled by different mechanisms; in the normal culture medium containing 5.4 mM KCl, numerous cells were stained intensely with anti-GABA antiserum, whereas only a few were stained intensely either with HPC-1 or MAP2 antibody. In a culture medium with a high concentration of KCl (35 mM), which may induce depolarization of nerve cells, numerous cells became strongly positive for HPC-1 or MAP2; both the cell bodies and the neuritic fibers were stained positively. Since cells intensely immunoreactive to GABA, HPC-1 or MAP2 were not found in intact pineals of the rat, the present results indicate that the neuronal potency of the rat pineal cells is expressed only in vitro and is suppressed in vivo, and that the potency is lost during postnatal development. Norepinephrine at 1 microM, which suppresses differentiation of rhodopsin immunoreactive cells, was ineffective in inducing phenotypic expression of neuronal properties in the present system, indicating that the mechanism of suppression of neuronal properties in the intact pineal may be different from the one for photoreceptors.

Animals↗
PubMed1994

Visualization of a moving quadrupole with magnetic measurements of peripheral nerve action fields.

Magnetic compound action fields (CAFs) over the right arm were measured from 63 sensor positions with two 7-channel SQUID gradiometer systems following electrical stimulation of the median nerve at the wrist. The field mapping of the CAFs revealed a propagating quadrupolar pattern with the leading depolarization and trailing repolarization fronts. The average distribution of the CAFs in the longitudinal direction was 9.0 cm in length for the depolarization field and 7.3 cm for the repolarization field in good agreement with a theoretical prediction based on the duration (3 msec) of the CAFs and the conduction velocity of the nerve (50 m/sec). The distance between the maxima of the depolarization front and the minima of the repolarization front was 6.3 cm. This spatial separation of the leading and trailing dipole locations suggests in part mutual cancellation of the fields with opposite polarity at or near the depolarized segment of nerve fibers.

Adult↗
PubMed1993

[A case of hypothalamic hamartoma with gelastic seizures, precocious puberty, poly- and syndactyly].

We reported a 6-month-old boy, patient of hypothalamic hamartoma with a rare association of poly- and syndactyly, which developed gelastic seizures and precocious puberty. His birth was complicated by poly- and syndactyly in both hands and polydactyly in both feet, but other physical signs were normal. At 5 month of age, he visited our hospital because of a suspected seizure. On admission, physical and neurological examinations revealed increased size in penis and testes, and delayed psychomotor development. Gelastic seizures occurred up to 100 times a day, and were resistant to many anticonvulsants. Ictal EEG showed bursts of generalized high voltage slow waves. His serum LH and testosterone levels were elevated for his age. Brain CT and MRI demonstrated a hypothalamic mass lesion, which proved to be hamartoma by biopsy.

Epilepsy↗
PubMed1991

Describing head shape with surface harmonic expansions.

Surface harmonic expansions are used to represent boundaries between regions of different conductivity in the human head. This facilitates calculation of the electric potential and magnetic field generated by neural current sources using discretized integral equations.

Computer Simulation↗
PubMed1989

T-cell clones with L3T4-positive or Lyt-2-positive phenotypes responding to mutant MHC class II antigen and inducing graft versus host reaction.

Two types of T cell clones responding to mutant major histocompatibility class II antigen (Iabm12) were established from spleen cells of C57BL/6 mice: one was L3T4-positive and the other Lyt-2-positive. These two types of clones carried functionally different properties. Lyt-2+ clones were absolutely dependent on exogenous interleukin-2 for their proliferation, whereas some L3T4+ clones secreted interleukin-2 and proliferated autonomously. Both types of clones had cytotoxic activities to bm12 target cells, and Lyt-2+ clones showed stronger activities than L3T4+ clones. Lyt-2+ clones induced induration in situ, whereas the L3T4+ clones induced ulcerative reaction when injected intradermally into mice. Histologically, the L3T4+ clones caused necrosis of the epidermis or upperdermis, while the Lyt-2+ clones induced infiltration of small round cells through the epidermis to the subcutaneous tissues and caused thickening of the epidermis. These characteristic reactivities might be due to a difference in lymphokines produced by each type of T cell subset in response to Iabm12 antigen.

Animals↗
PubMed1987

[Seasonal changes in the course of atopic eczema].

To investigate seasonal changes of the course of atopic dermatitis, questionnaires were sent to patients treated for this condition in 1984. The replies obtained from 506 patients indicated that in most of them the skin condition deteriorated in winter and improved in summer. However, among patients older than 5 years the proportion of those with deterioration in summer was higher. It is suggested that seasonal factors greatly influence the skin condition of patients with atopic dermatitis and that these seasonal variations often depend on age and environment.

Adolescent↗
PubMed1985

Establishment of T-cell clones recognizing difference in H-2K antigen and inducing graft-versus-host disease.

From the spleen cells of C57BL/6 (B6) mice, T-cell clones were established which responded to mutant H-2K antigen of B6. B-H-2bml (Hz1) mice. One clone and its subclones were maintained in culture medium containing lower concentration (2.5%) of IL-2 (culture supernatant of rat spleen cells stimulated with concanavalin A). They were shown to have a capability to induce graft-versus-host reaction in (B6 X Hz1)F1 recipients as well as to exert cytotoxicity against concanavalin-A-activated spleen cells of Hz1 mice and also their kidney fibroblasts. They lacked cytotoxicity against syngeneic and also third-party Con-A-stimulated spleen cells. These reactive clones were Thy-1.2 and Lyt-2 positive and Lyt-1 negative. On the other hand, clones which were maintained in culture medium containing higher concentration (20%) of IL-2 were devoid of activities in vivo as well as in vitro. These clones were Thy-1.2 positive but Lyt-1.2 and Lyt-2.2 negative.

Animals↗