Biomedical subjects

I Hashimoto

Publications and source records attributed to I Hashimoto.

At least 19 recordsLinked to original sources

PubMed1995

Expression of collagenase and stromelysin in skin fibroblasts from recessive dystrophic epidermolysis bullosa.

Collagenase and stromelysin expression in recessive dystrophic epidermolysis bullosa (RDEB) was studied at both the protein and the gene expression levels in fibroblast cultures. The amount of enzyme protein in the culture medium, as determined using a specific enzyme assay, showed a 9.7-fold increase in collagenase and a 2.7-fold increase in stromelysin in RDEB fibroblasts (n = 4 patients) compared with controls (n = 3 subjects with normal skin). Collagenase activity was extremely high in all RDEB fibroblasts. Gene expression, as assessed by Northern blot hybridization, was increased in two sets of RDEB fibroblasts with respect to collagenase, and in two other sets of RDEB fibroblasts with respect to stromelysin. The effect of interleukin-1 alpha (IL-1 alpha) on metalloproteinase expression was also examined. The results revealed that: 1) collagenase and stromelysin expression was variably increased at both the protein and the gene expression levels in RDEB fibroblasts; (2) the gene expression level did not always reflect the corresponding protein level; and (3) IL-1 alpha produced a differential effect on collagenase and stromelysin expression. Although the causative gene for RDEB is a type VII collagen, the abnormal expression of collagenase and/or stromelysin is still important in considering the pathophysiology of RDEB.

Adolescent↗

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↗

PubMed1995

Perceptual changes accompanying controlled blocking of cutaneous afferents are related to somatosensory evoked potentials.

We examined the effect of local anaesthesia of the skin on somatosensory evoked potentials (SEPs) and psychophysical magnitude estimates for a constant intensity air-puff stimulation (7 kg.cm-2) in 23 normal subjects. Before and after intradermal injection (0.1 ml of 1% xylocain) to the tip of the right index finger, magnitude estimations for the four modalities of skin sensation (touch, pressure, pain and vibration), and SEPs were successively examined at 4-10 min interval until complete sensory and SEP recovery. The time course of sensory recovery was similar for the first three modalities and vibration sense was little affected by local anaesthesia. Immediately after anaesthesia, SEPs either abolished or decreased in amplitude. Thereafter amplitudes increased and peak latencies decreased with the elapsed time. Comparison of the regression lines for the amplitude of P45-N60 component or the time-integrals of N20 and N35 components with that of psychophysical estimates revealed steeper slopes for psychophysical data: 0.4-0.7 for neural versus 1.4-1.7 for psychophysical data. These relations between SEPs and psychophysics following local anaesthesia bear a close parallel to those observed in our previous studies in a normal condition with increasing stimulus intensity. The SEP latencies for N20, P27 and N35 components were better correlated with recovery from anaesthesia. Direct comparisons of SEP measures with subjective magnitudes produced significant correlations for the three modalities of sensation in which again latencies are better correlated than amplitides or time-integrals.

Adolescent↗

PubMed1995

Striated muscle hamartoma of the nostril.

We observed two females, an 11-month old and a 15-year-old, each with a round, soft mass in the nostril. Histologically, numerous bundles of striated muscle fibers were seen in the masses among normal dermal components. The lesions were excised without complications. Four patients with similar lesions confirmed clinically and histologically have been reported in the literature under various diagnostic names. These masses were diagnosed as striated muscle hamartomas in view of their characteristic features: congenital round, soft masses on the midline of the head or neck with multiple, mature striated muscles observed in the mass. Since these lesions may be associated with such anomalies as amniotic band syndrome and lipoma of the brain, a complete medical examination is required of such patients.

Adolescent↗

PubMed1995

Successful treatment of dark-colored epidermal nevus with ruby laser.

The pulsed ruby laser has a selective thermolytic effect. Recently, it has been available for the treatment of superficial pigmented disorders. We studied 5 cases of epidermal nevus treated with the pulsed ruby laser. In comparison with the usual methods including electrocautery, cryotherapy and skin abrasion, ruby laser therapy is an excellent tool due to technological ease and rapid improvement. Depigmentation after treatment in 2 cases was the only side effect of this therapy. Bose cases had a dark pigmentation of the skin. Despite of the risk of discoloration, the ruby laser is one of the most effective tools for therapy of pigmented epidermal nevus.

Adolescent↗

PubMed1995

Bronchial hyper-responsiveness to inhaled histamine in children with congenital heart disease.

In order to assess bronchial responsiveness in patients with congestive heart failure secondary to congenital heart disease, we performed a histamine inhalation test while monitoring transcutaneous oxygen tension and compared the respiratory threshold to histamine with that obtained in patients with bronchial asthma. The inhalation test was performed by doubling concentrations of histamine solution for 2 min at 1 min intervals. The respiratory threshold of histamine was defined as the minimal concentration causing a drop in transcutaneous oxygen tension greater than 10% from baseline. Six of 10 patients with congenital heart disease and all of 12 patients with bronchial asthma had bronchial hyper-responsiveness to histamine. The mean of histamine concentration was 2750 micrograms/mL and 937 micrograms/mL, respectively. During the histamine inhalation test, respiratory resistance gradually increased in congenital heart disease patients. This was measured by the linear slope of transcutaneous oxygen pressure (-1.08 +/- 0.75 mmHg/min), whereas in the bronchial asthma patients it rapidly decreased at the infection point (-4.19 +/- 1.86 mmHg/min). We conclude that children with congestive heart failure had bronchial hyper-responsiveness. We suggest bronchial hyper-responsiveness to inhaled histamine in congestive heart failure was caused by the gradual increased respiratory resistance, which was different from that of bronchial asthma.

Blood Gas Monitoring, Transcutaneous↗

PubMed1995

[A case of ANCA negative Wegener's granulomatosis with pulmonary giant bulla showing high level of soluble ICAM-1].

This paper reports a rare case of the limited form of Wegener's granulomatosis (WG) with pulmonary giant bulla, which was pathologically identified only in the lung and showed a high level of soluble intercellular adhesion molecule-1 (ICAM-1) but not anti-neutrophil cytoplasmic antibody (ANCA). A 46 year-old male was admitted for the further examination of right anterior chest pain and dyspnea. Chest X-ray and CT examination showed giant bulla accompanied with the invasive lesions in upper lobe of right lung. Partial lobectomy was done. Granulomatous and necrotizing vasculitis characteristics of WG were confirmed by the histopathology of resected tissues. Immunological analysis on admission showed a high level of soluble ICAM-1 and ANCA negative, but that of soluble ICAM-1 was reduced after surgical operation and remained within normal range during an administration of prednisolone and cyclophosphamide. These results suggest that soluble ICAM-1 may be one of the useful parameters for a diagnosis of WG and for an estimation of its treatments, especially in the cases of ANCA negative WG.

Antibodies, Antineutrophil Cytoplasmic↗

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↗

PubMed1992

Association of annexin V with prolactin in the rat anterior pituitary gland.

When pituitary extracts were subjected to non denaturing polyacrylamide gel electrophoresis, an unknown protein was found to associate with a proportion of the prolactin. This protein was dissociated from prolactin by sodium dodecyl sulfate. The protein was purified and sequenced. As the amino terminus was blocked, the amino acid sequences of three peptide fragments were determined. The obtained sequences of 41 amino acids were identical to partial sequences of a known protein, rat Annexin V. The molecular mass, 36 kDa, was also the same as the molecular weight of Annexin V. The existence of Annexin V mRNA in rat pituitary glands was also confirmed by polymerase chain reaction. These results show that Annexin V, a member of the calcium-dependent phospholipid binding proteins, is synthesized in the rat pituitary gland, and suggest its association with prolatin in the gland.

Animals↗

PubMed1992

Somatosensory evoked potential correlates of psychophysical magnitude estimations for air-puff stimulation of the foot in man.

Short air-puff stimuli were applied to the sole of the right foot to obtain both psychophysical and neurophysiological responses. The detection threshold (So) was first determined, and six levels of stimulus intensity above threshold were adopted for magnitude estimation. Somatosensory evoked potentials (SEPs) were also recorded over the foot projection area (2 cm posterior to Cz) for the six stimulus intensities. Six components (N40, P45, N55, P70, N80 and P90) were recorded within 100 ms following stimulation. A power function with an exponent of 0.94 provided an adequate description of the magnitude estimation values as a function of stimulus intensity, as was verified by the high correlation coefficient (r = 0.87; P < 0.001). Similarly, stimulus-amplitude functions of P45-N55, N55-P70 and P70-N80 SEP components were well represented by power functions with exponents of 0.62, 0.63 and 0.78, respectively. The SEP latencies as a function of stimulus intensity had negative power functions. The latency functions of the P45 and N55 components had the largest negative power exponents (-0.17 and -0.15) and showed the highest negative correlations (r = -0.70 and -0.71, respectively) with the stimulus intensity. These results suggest that both the amplitude and the latency information encoded in the SEPs may contribute to the magnitude estimation of the stimulus.

Adult↗

PubMed1992

Somatosensory evoked potential correlates of psychophysical magnitude estimations for air-puff stimulation of the face in man.

Air-puff stimuli were applied to the skin of the face to obtain psychophysical and neurophysiological responses. Six levels of stimulus intensity above threshold were adopted for numerical magnitude estimation and for recording somatosensory evoked potentials (SEPs). A power function with an exponent of 0.71 provided an adequate description of the magnitude estimation values as a function of stimulus intensity, as was verified by the high correlation coefficient (r = 0.86, P less than 0.001). Six SEP components (N15, P20, N30, P40, N50 and P65) were recorded during the 100 ms following stimulation. Stimulus-amplitude functions of the various SEP components were well represented by power functions. The P20-N30 component had the highest power exponent (0.66) and also the highest correlation coefficient (r = 0.55, P less than 0.001). The SEP latencies as a function of stimulus intensity had negative power functions. The latency function of the P20 component had the largest negative power exponent (-0.10) and showed the highest negative correlation (r = -0.62) with the stimulus intensity. These results suggest that processing of intensity information occurs at a relatively early stage within the central nervous system, and that both the amplitude and latency information encoded in the SEPs may contribute to stimulus processing.

Adult↗

PubMed1992

Input-output relation of the somatosensory system for mechanical air-puff stimulation of the index finger in man.

This study examined input-output relation of the somatosensory system in response to mechanical air-puff stimuli applied to the volar aspect of the tip of the index finger. Compound sensory nerve action potentials (SNAPs) from the median nerve at the wrist and cerebral somatosensory evoked potentials (SEPs) were simultaneously recorded at six levels of stimulus intensity above threshold. Using the time-integral of the SNAPs and SEPs as measures of peripheral and central neural activity, a strongly accelerating power function with an exponent of 1.35 was found to describe peripheral neural function, while central neural function was described by a negatively accelerating function with a power exponent of 0.50, suggesting suppression of SEPs by recruitment of units with increasing stimulus intensity. It was concluded that input-output relation of the somatosensory system can be described by a decelerating power function with the exponent of 0.37.

Action Potentials↗

PubMed1992

Inhibitory effect of the leukotriene B4 receptor antagonist against hypomagnesic diet-induced dermatitis in hairless rats.

In vivo experiments have shown that magnesium deficiency elicits characteristic skin lesions in the hairless rat. However, the mechanism of the involvement is not clarified. From the results of previous studies, a product derived from arachidonic acid, but not via the cyclooxygenase pathway, has been considered as an etiological cause. In this study, the inhibitory effect of newly produced leukotriene B4 (LTB4) receptor antagonist (LTBRA) against these skin manifestation was examined in hairless mutants given a hypomagnesic diet. Control animals with treatment of LTBRA developed eruptions on their bodies with increasing serum levels of LTB4, but LTBRA-treated animals did not suffer from the cutaneous disorder. Increased serum levels of LTB4 in control rats were significantly higher than those in the pre-treated condition. The diminution of skin lesions by LTBRA strongly indicated that magnesium deficiency dermatitis may involve a lipoxygenase-mediated metabolite of arachidonic acid, presumably LTB4, and that the cutaneous changes in hairless rats fed with hypomagnesic diet might provide an easily identifiable indicator of LTB4-mediated dermatitis.

Animals↗

PubMed1992

Analysis of left ventricular regional wall motion in normal neonates.

OBJECTIVE: To investigate neonatal circulatory change by quantitative analysis of left ventricular regional wall motion. DESIGN: Random prospective study. SETTING: Department of paediatrics in a teaching hospital. PARTICIPANTS: 66 neonates born after a normal pregnancy, labour, and delivery. INTERVENTIONS: Quantitative analysis of left ventricular regional wall motion was performed on cross sectional echocardiograms. M mode, cross sectional, and Doppler echocardiograms were obtained simultaneously. MAIN OUTCOME MEASURES: Manually traced endocardial contours at end diastole and at end systole were realigned by superimposing the centre of the ventricular mass and the axis. The contours were divided into 24 segments with 24 radii of equal arc from the centre. Then the ratio of the change in area between the outline of the contour and the two hemiaxes was calculated automatically. RESULTS: There was hyperkinesis of the interventricular septum in the first 24 hours after birth which continued until the end of the first week. Simultaneous echocardiographic examination showed evidence of pulmonary hypertension, as indicated by an increase in the ratio of the right pre-ejection period to the right ventricular ejection time (RPEP/RVET) and of the diameter ratio of the pulmonary artery to the aorta and a shortening of the acceleration time of pulmonary arterial blood flow. These features disappeared within a week. CONCLUSIONS: Hyperkinesis of the interventricular septum may reflect circulatory changes that are characteristic of the early neonatal period.

Diastole↗

PubMed1992

[Magnetic resonance imaging: evaluation of the Blalock-Taussig shunts and anatomy of the pulmonary artery].

The morphology and circulation of the pulmonary arteries and shunt vessels were evaluated by magnetic resonance imaging (MRI) in 8 patients with cyanotic heart disease after a Blalock-Taussig shunt operation. Their ages ranged from one month to 17 years. MRI permitted assessment of the size and patency of the Blalock-Taussig shunts, as well as the size and morphology of the pulmonary arteries in all patients. Measurements of the vessel diameters on MRI correlated well with the angiographic measurements (main pulmonary artery, r = 0.98; right pulmonary artery, r = 0.98; left pulmonary artery, r = 0.98; and Blalock-Taussig shunt, r = 0.97). MRI successfully imaged 3 of 4 shunt obstructions and 3 of 4 pulmonary stenoses with high resolution. In assessing peripheral pulmonary stenosis or obstruction, MRI was superior to echocardiography, the latter being unable to image peripheral pulmonary arteries satisfactorily. We concluded that MRI is an excellent noninvasive method for serially evaluating the anatomy and function of Blalock-Taussig shunts and pulmonary arteries, which is particularly useful for children with cyanotic congenital heart disease.

Adolescent↗

PubMed1991

Increased gene expression of matrix metalloproteinase-3 (stromelysin) in skin fibroblasts from patients with severe recessive dystrophic epidermolysis bullosa.

Gene expression of matrix metalloproteinase 3 (MMP-3 = stromelysin) was examined in the skin fibroblasts obtained from patients with severe recessive dystrophic epidermolysis bullosa (RDEB). Steady-state mRNA level of MMP-3 was selectively increased in the unstimulated RDEB cells by a post-transcriptional mechanism. A parallel study on the susceptibility of type VII collagen to MMPs revealed that this type of collagen is degraded by MMP-3, but not by MMP-1 (collagenase). These data suggest that MMP-3 may play an important role in the blister formation fo the skin in RDEB patients by the degradation of anchoring fibrils consisting of type VII collagen.

Blotting, Northern↗

PubMed1991

Multi-unit activity in sensory fibers is related to intensity of sensation evoked by air-puff stimulation of the glabrous hand in man.

An analysis of a multi-unit activity (MUA) recorded from the median nerve at the wrist was undertaken to study intensity coding in the peripheral somatosensory system. Brief air-puff stimuli were applied over the glabrous hand to obtain neural and psychophysical responses. The detection threshold (So) was determined and 6 above-threshold stimulus intensities (So + 0.25 kg/cm2, So + 1.25 kg/cm2, So + 2.50 kg/cm2, So + 3.75 kg/cm2, So + 5.00 kg/cm2, and So + 6.25 kg/cm2) were adopted for magnitude estimation. MUA was recorded for the 6 stimulus intensities and for the threshold (So) level. Response duration, number and frequency of the MUA were evaluated as candidate coding parameters for stimulus intensity. A simple power function with an exponent of 1.03 provided an adequate description of the magnitude estimation function. Similarly, stimulus-response functions of the 3 parameters defining the MUA were well represented by straight lines in double logarithmic plots, with the function of the MUA number having the highest power exponent (0.98) and also the highest correlation coefficient. The results suggest that the total number of MUA, representing spatial recruitment, is the most relevant coding parameter for the subjective magnitude estimation of the stimulus intensity.

Adult↗