Biomedical subjects

S Yanagimoto

Publications and source records attributed to S Yanagimoto.

At least 19 recordsLinked to original sources

PubMed2005

Changes in the index of sweat ion concentration with increasing sweat during passive heat stress in humans.

To investigate the pattern changes in the index of sweat ion concentration at skin surface with increasing sweat during passive heat stress in humans, we measured conductivity of the perfused water with sweat as the index of sweat ion concentration and sweat rate, continuously at the chest skin surface. Eight healthy subjects (22.4 +/-1.0 years) were passively heated by lower-leg immersion in a hot water bath of 42 degrees C for 50 min in an ambient temperature of 28 degrees C and relative humidity of 50%. The internal temperature (Tor) thresholds of sweat rate and index of sweat ion concentration were almost similar. Concomitant onset for the index of sweat ion concentration and sweat rate occurred but two types of linear regression lines were identified in the relationship between the index of sweat ion concentration and sweat rate at a boundary sweat rate value of 0.30 +/- 0.08 mg cm(-2) min(-1). The slope of the regression line at low levels of sweat (slope 0.02 +/- 0.01 V mg(-1) cm(-2) min(-1)) was significantly gradual compared with that at moderate levels of sweat (slope 0.30 +/- 0.08 V mg(-1) cm(-2) min(-1)) (P<0.05). These results suggest that at low levels of sweat the index of sweat ion concentration responds gradually with respect to sweat rate, which may be due to the ion reabsorption capacity of the sweat duct, and then the index of sweat ion concentration increased steeply with sweat rate.

Adult↗

PubMed2002

Sweating response in physically trained men to sustained handgrip exercise in mildly hyperthermic conditions.

To investigate the effects of physical training on heat loss response to sustained handgrip exercise (non-thermal factors), we compared the sweating response during isometric handgrip exercise to mild hyperthermia in physically trained and untrained subjects. Seven trained and untrained male subjects (maximal oxygen uptake 62.7 +/- 2.4 and 42.7 +/- 1.6 mL kg-1 min-1, respectively, P < 0.05) performed isometric handgrip exercises at 20, 35 and 50% maximal voluntary contraction (MVC) for 60 s. The study was conducted in a climatic chamber with a regulated ambient temperature of 35 degrees C and relative humidity of 50% to induce sweating response at rest by rising skin temperature without a marked change in internal temperature. Sublingual and mean skin temperatures (thermal factors) in both trained and untrained groups were essentially constant throughout all exercise intensities. Changes in heart rate, mean arterial blood pressure, and rating of perceived exertion with increased exercise intensity were similar in both groups. Sweating rate (SR) on the limbs (mean value of forearm and thigh) was significantly greater in the trained group than in the untrained group at 50% MVC (P < 0.05). In addition, the slopes of the relationship between increased SR and exercise intensity (% MVC) on the trunk (chest) and limbs were significantly greater in the trained group than in the untrained group (P < 0.05). Our results suggest that the sweating response caused by non-thermal factors against a background of changing thermal factors was enhanced by physical training. It is also thought that the enhanced sweating response may be especially evident on the limbs than on the trunk, such as improvement of sweating response associated with thermal factors.

Adult↗

PubMed2001

Homonymous defect of macular vision in ischemic stroke.

It is generally believed that a homonymous defect of macular vision (HMV) is caused by a small lesion restricted to the occipital lobe tip and rarely results from ischemic stroke. The incidence of HMV was studied retrospectively in 54 patients with infarction of the posterior cerebral artery territory who underwent Goldmann's visual field test. HMV was found in 6 patients (11%). In all of them, HMV was first dismissed due to a confrontation test of visual fields at the bedside and later detected by Goldmann's visual field test. All had a relatively large infarction extending from the occipital lobe tip to the posterior part of the calcarine cortex and/or the neighboring subcortical regions. Stroke-induced HMV can be caused by a large lesion involving the occipital pole and may not be so rare as generally considered.

Aged↗

PubMed2001

[A case of combined paraneoplastic neurological syndrome, with Lambert-Eaton myasthenic syndrome manifesting as severe respiratory failure, and anti-Hu syndrome].

A 63-year-old man complained of rapidly progressive respiratory failure, requiring a control respiration. He subsequently, presented with muscle weakness involving the neck and all the extremities, superimposed by painful paresthesia. He was proven to carry small-cell lung cancer (SCLC). Neurophysiological examinations revealed the waxing phenomenon at 30 Hz repetitive motor nerve stimulation. Positive serum autoantibodies were detected to voltage-gated calcium channel and Hu proteins. He received diagnosis of combined Lambert-Eaton myasthenic syndrome (LEMS) and anti-Hu syndrome. The initial chemotherapy for SCC alleviated his respiratory and neurological symptoms. But he developed multiple cranial palsies and fatal respiratory distress two months later. There is only a few reports about LEMS complicated by respiratory failure as an initial presentation. Various clinical manifestations including respiratory failure at the onset could be best explained by the combination of LEMS and anti-Hu syndrome in this case.

Antibodies, Antinuclear↗

PubMed1999

[Development of a simple method for the washout correction of 123I-IMP SPECT and its application to a quantitative rCBF method].

We have developed a simple method to correct the washout of tracer from the brain based on the two-compartment model in brain early SPECT using N-isopropyl-p-[123I]iodoamphetamine (123I-IMP). This correction was applied to a new quantitative method of regional cerebral blood flow (rCBF) in combination with the microsphere method by continuous arterial sampling previously reported. Data acquisition of 123I-IMP early SPECT was started from 35 min after 123I-IMP i.v. injection, and the time activity curve of whole brain on anterior head planar images was monitored immediately after 123I-IMP i.v. injection for the correction of washout of tracer from the brain. The usefulness of this method was evaluated in 12 patients with various brain diseases by comparison with the results obtained from the super-early SPECT at 7-10 min after 123I-IMP i.v. injection. The washout rates in cases of early SPECT corrected by this method ranged from 16.91% to 39.34% with a mean +/- SD of 27.72 +/- 5.44%. The contrast of hypo- to hyperperfusion regions on early SPECT was improved by the correction of the washout, and its intracerebral distribution was similar to the simultaneously obtained super-early SPECT images. These results indicated that the present correction method for the washout was useful for more correct quantification of rCBF.

Brain↗

PubMed1999

[Chronological study for solitary bone metastasis in the sternum from breast cancer with bone scintigraphy].

Since breast cancer is frequently associated with bone metastasis, bone scintigraphies have been performed to determine pre-operative staging and to survey postoperative bone metastasis. The sternum, in particular, is a site at which is difficult to differentiate between benign bone disease and bone metastasis, because of varied uptake and wide individual variations. In this study, chronological bone images were scintigraphied in six cases with solitary sternal metastasis and three cases with benign bone disease including two fracture cases and one arthritis case. On bone scintigrams in which solitary sternal metastasis appeared, increased uptake was found in five cases, and photon deficiency was observed in one case. During follow-up scintigraphies, abnormal accumulations, such as hot spots and cold lesions, increased in the bone metastasis while abnormal uptake disappeared or was unchanged in the benign bone disease cases. On CT, four cases showed osteolytic change, and one exhibited osteosclerotic change. These findings indicate that sternal metastasis usually shows osteolytic change, even if a hot lesion is recognized on bone scintigraphy. In solitary sternal metastasis, for which early diagnosis is difficult, both an integrated diagnosis using other imaging techniques and chronological bone scintigraphy are important.

Adult↗

PubMed1999

[Usefulness of 67Ga scintigraphy in deciding surgical indication in secondary hyperparathyroidism].

In order to evaluate the usefulness in deciding surgical indication in secondary hyperparathyroidism (SHP), 67Ga scintigraphy was performed in 37 patients of SHP before parathyroidectomy (PTx). The radionuclide accumulation in skull and submandible was classified into 4 patterns (skull-submandibular pattern, skull pattern, submandibular pattern and normal pattern). Serum alkaline phosphatase levels were significantly elevated in patients of skull-submandibular pattern (13 cases) compared with skull pattern (6 cases), submandibular pattern (6 cases) and normal pattern (12 cases). Serum intact parathyroid hormone levels were significantly elevated in patients of skull-submandibular and skull patterns compared with normal pattern. No significant difference was observed among the weight of resected parathyroid glands. In 4 of 6 patients of normal pattern on 67Ga scintigram, bone scintigraphy showed a characteristic pattern of SHP including an increased accumulation in the skull and submandible. Bone mineral density (BMD) in the distal radius was increased within six to twelve months after PTx in 10 of 11 patients of skull-submandibular pattern on 67Ga scintigram, whereas only one patient showed an increase in BMD in 9 patients of normal pattern. In summary, it was concluded that 67Ga scintigraphy could provide a useful information in deciding the indication for PTx in secondary hyperparathyroidism.

Citrates↗

PubMed1999

[A case of acute transverse myelopathy and bilateral optic neuritis associated with anticardiolipin antibodies, lupus anticoagulant and perinuclear antineutrophil cytoplasmic antibodies].

A 69-year-old woman developed paraplegia and hypesthesia on upper extremities and below T4 level. Examination of cerebrospinal fluid showed increased protein levels and pleocytosis. MRI of the cervical spinal cord revealed syrinx formation from C3 to upper thoracic cord. A diagnosis of acute transverse myelitis was made. A high dose of corticosteroid including pulse therapy did not improve her symptoms and signs of myelopathy, but the syrinx could not be found thereafter. One year later, she developed severe visual loss due to bilateral optic neuritis which was improved spontaneously. The clinical course and MRI findings were similar to those of the optic-spinal form of multiple sclerosis (MS). The presence of anticardiolipin antibodies, lupus anticoagulant and perinuclear anti-neutrophil cytoplasmic antibodies, however, strongly suggested that vasculitic and/or ischemic mechanisms induced by these autoantibodies might play a role on the development of the disease. We conclude that our case should be distinguished from MS.

Acute Disease↗

PubMed1997

Effects of hydralazine on responses to histamine and caffeine in ileal longitudinal muscle and taenia coli of the guinea pig.

1. The mechanism of tension inhibitory effects on histamine and caffeine-induced responses by hydralazine were studied in the ileal longitudinal muscle and taenia coli of the guinea-pig. Hydralazine, 10(-4) to 3 x 10(-3) M, inhibited both the tonic response and the increase in Ca uptake by the lanthanum (La) method evoked by histamine (10(-5) M) without affect on Ca efflux, with smaller effects on the phasic response in ileal muscle. 2. Hydralazine suppressed caffeine- and IP3-induced contractions after loading with Ca2+ into the storage sites in saponin-treated fibers. However, hydralazine suppressed the caffeine- and IP3-induced contractions in the skinned fibers relatively less than both the transient response to caffeine and phasic response to histamine in intact muscles, respectively. 3. It is probable that hydralazine reduces the tonic response to histamine mainly by inhibiting Ca2+ influx through receptor operated Ca2+ channels in the ileum. In addition, hydralazine also decreases caffeine- or IP3-induced Ca2+ release from storage sites.

Animals↗

PubMed1997

Spinocerebellar ataxia type 6. Molecular and clinical features of 35 Japanese patients including one homozygous for the CAG repeat expansion.

Spinocerebellar ataxia type 6 (SCA6) is a newly classified autosomal-dominant cerebellar ataxia (ADCA) associated with CAG repeat expansion. We screened 111 patients with cerebellar ataxia for the SCA6 mutation. Of these, 35 patients were found to have expanded CAG repeats in the SCA6 gene, indicating that second to SCA3, SCA6 is the most common ADCA in Japan. Expanded alleles ranged from 21 to 29 repeats, whereas normal alleles had seven to 17 repeats. There was no change in the CAG repeat length during meiosis. The age at onset was inversely correlated with the repeat length. The main clinical feature of the 35 patients with SCA6 was slowly progressive cerebellar ataxia; multisystem involvement was not common. The 35 patients included nine cases without apparent family history of cerebellar ataxia. The sporadic cases had smaller CAG repeats (21 or 22 repeats) and a later age at onset (64.9 +/- 4.9 years) than the other cases with established family history. We also identified one patient who was homozygous for the SCA6 repeat expansion. The homozygote showed an earlier age of onset and more severe clinical manifestations than her sister, a heterozygote carrying an expanded allele with the same repeat length as the homozygote. This finding suggests that the dosage of the CAG repeat expansion plays an important role in phenotypic expression in SCA6.

Adult↗

PubMed1997

[Compartment analysis of 123I-iomazenil brain on early and delayed SPECT].

We investigated the characteristics of 123I-Iomazenil (IMZ) SPECT images in 12 adults (six males and six females, with a mean age of 56.1 years). The washout rate of 123I-IMZ from the brain was estimated from two SPECTs done 15 min and 3 hr after injection. Although the washout was relatively slow, the rates differed in each intracerebral region, suggesting that the distribution of 123I-IMZ was gradually changing. Furthermore, assuming 123I-IMZ kinetics in the brain for the three-compartment, two-parameter model, the transition rate constant (K1) from the blood to the brain and the binding potentials (BP) of benzodiazepine to the receptor were calculated. The BP and K1 values were compared with 123I-IMZ SPECT counts and CBF values by 123I-IMP. The BP values correlated more closely with the counts on the delayed SPECT than those on the early SPECT. It was confirmed that delayed SPECT images reflect better the distribution of the benzodiazepine receptor than early images do. On the other hand, the K1 values correlated highly with CBF obtained by 123I-IMP, and this finding suggested that super-early SPECT images might be remarkably influenced by the distribution of CBF.

Adult↗

PubMed1997

[Comparative study on the tumor accumulation of 99mTc-tetrofosmin and 99mTc-MIBI in rabbits bearing VX-2 cancer].

Each of myocardial blood flow imaging agents has a potential usefulness as an agent for tumor scintigraphy. The tumor accumulation and washout of 99mTc-tetrofosmin and 99mTc-MIBI were comparatively studied using rabbits bearing VX-2 cancer. From seventeen to twenty days after the implantation of VX-2 cancer into the femoral region of seven rabbits, tumor to soft tissue accumulation ratio (T/S ratio) of each agent was calculated in early images (5 min after injection) and in late images (50 min after injection). Compared with 99mTc-tetrofosmin, the T/S ratio of 99mTc-MIBI was higher and, moreover, the washout was delayed. These results suggest that there is a difference in tumor accumulation property between these two agents.

Animals↗

PubMed1996

Budd-Chiari syndrome attributed to protein C deficiency.

The protein C anticoagulant pathway is an important downregulating mechanism of the blood coagulation cascade. We report a 47-yr-old male with Budd-Chiari syndrome and occlusion of the inferior vena cava. His plasma protein C antigen level was decreased to 42%, and its activity was 34%. Other coagulable factors were normal. Protein C deficiency should be considered a possible etiological factor of the Budd-Chiari syndrome.

Alcoholism↗

PubMed1996

Inhibition of calcium influx and tonic response to K+ of intestinal smooth muscle by hydralazine.

1. Evidence concerning the mechanism of the inhibition of contraction caused by hydralazine has been sought in ileal longitudinal muscle and taenia coli of guinea-pig. Hydralazine (10(-3)-3 x 10(-3) M) markedly inhibited K+ (60 mM) induced tonic response with smaller effects on the phasic response in the ileal muscle. However, 10(-2) M hydralazine completely abolished both responses. 2. Hydralazine increased the threshold for Ca2+ induced contraction in Ca2+ free, K+ depolarized taenia coli and reduced the maximal response size. A low concentration (3 x 10(-10) M) of nifedipine, an L-type Ca2+ channel blocker, further caused a parallel shift to the right in the presence of hydralazine in the concentration-response curves obtained with Ca2+ 3. Hydralazine caused a significant decrease in Ca2+ uptake measured by the lanthanum method during the K+ induced tonic response in ileal muscle; however, it did not affect the Ca2+ efflux. 4. In ileal muscle fibres treated with Triton-X-100, in which the Ca2+ release sites are destroyed, 10(-3) M hydralazine had no effect on the contractions induced by 10(-5) M Ca2+; however, hydralazine at a higher concentration (10(-2) M) had a slight inhibitory effect on the contraction. 5. The present finding indicates that the inhibitory action on contractions produced by hydralazine may result mainly from the interference of calcium permeability at the cell membrane in ileal muscle. There is the possibility that hydralazine of higher concentrations may have a minor action on the contractile system.

Animals↗

PubMed1995

[Detection and localization of enlarged parathyroid glands in patients with hyperparathyroidism using 99mTc-methoxyisobutylisonitrile (MIBI): a study of subtraction scintigraphy with 99mTc-pertechnetate].

In this study we investigated the detectability of abnormal parathyroid gland(s) by 99mTc-methoxyisobutylisonitrile (MIBI) scintigraphy in patients with hyperparathyroidism. The subjects were 6 patients with primary hyperparathyroidism (PHP) with a single adenoma and 13 patients with renal hyperparathyroidism (RHP) on chronic maintenance hemodialysis. The imaging data of 99mTc-pertechnetate were subtracted from those of 99mTc-MIBI (MIBI-Tc), and number and location of the positive images on scintigrams were compared with those obtained by conventional scintigraphy using 201Tl-Cl and 99mTc-pertechnetate (Tl-Tc). All of the patients underwent surgery, and the number and location of the abnormal parathyroid glands were confirmed. The number of resected parathyroid glands were 6 in PHP and 52 in RHP. The detectability of MIBI-Tc was 83.3% in PHP and 51.9% in RHP, while that of Tl-Tc was 100% and 44.2%, respectively. Although no statistically significant difference in the detectability was found between MIBI-Tc and Tl-Tc, the number of false positives with MIBI-Tc was less than that with Tl-Tc. The detectability of MIBI-Tc depended on the size of the parathyroid gland. The maximal diameter and weight of the smallest parathyroid gland detected were 15 mm and 290 mg in PHP, and 9 mm and 50 mg in RHP. The existence of the thyroid gland did not reduce the detectability of MIBI-Tc. In conclusion, MIBI-Tc was clinically very useful for the detection of abnormal parathyroid glands in patients with hyperparathyroidism.

Adult↗

PubMed1995

[Study on tumor accumulation property of 99mTc-HM-PAO and 99mTc-MIBI in rabbits bearing VX-2 cancer].

Each of blood flow imaging agents has a potential usefulness as an agent for tumor scintigraphy. The usefulness for tumor scintigraphy of two agents, i.e. cerebral blood flow scintigraphy agent 99mTc-HM-PAO and myocardial blood flow scintigraphy agent 99mTc-MIBI, was comparatively studied using rabbits bearing VX-2 cancer. From then to twenty days after the implantation of VX-2 cancer into the femoral region of five rabbits, tumor to soft tissue accumulation ratio (T/S ratio) of each agent was calculated in early images (5 min after injection) and in late images (50 min after injection). Compared with 99mTc-MIBI, the T/S ratio of 99mTc-HM-PAO was higher and, moreover, the washout was delayed. These results suggest that there is a difference in tumor accumulation property between these two agents.

Animals↗

PubMed1994

Spinocerebellar degenerations in Japan: a nationwide epidemiological and clinical study.

A nationwide survey of patients in Japan with spinocerebellar degenerations (SCD), including SDS and SND, was conducted from 1988 to 1989. The survey consisted of two parts. The first revealed that the estimated total number of patients with SCD in Japan was 5,050 (range: 4,100-6,000) with an estimated prevalence of 4.53 per 100,000 in 1987. The second part investigated the neurological and functional status of patients with SCD. The percentages of those belonging to each subtype of SCD were: OPCA; 34.4%, LCCA; 15.2%, MHCA; 12.6%, HHCA; 7.5%, SDS; 7.0%, HSP; 3.9%, DRPLA; 2.5%, FA; 2.4%, MJD; 2.0% and SND; 1.5%. Compared with European epidemiological studies Japan had a higher proportion of non-hereditary types of SCD. Various clinical features of SCD subtypes were compared grouped by pathological lesion and heredity. HHCA and LCCA: cerebellar ataxia predominated in all stages, and neurological signs other than cerebellar ataxia were rare. MHCA, DRPLA and MJD: in the early phase ataxia was the most common symptom in MHCA, the AC form of DRPLA and MJD, but ataxia was less common and chorea or epilepsy were often observed in ME and PH forms of DRPLA. Other frequently observed clinical features were parkinsonian rigidity in MHCA, abnormal movements and posture in DRPLA and MJD, and disturbances of eye movements in MHCA, the AC form of DRPLA and MJD. OPCA, SDS and SND: dominant clinical features were cerebellar ataxia in OPCA, autonomic disturbance in SDS, and parkinsonian rigidity in SND. FA and HSP: both were rare in Japan. Clinical features related to supra-supinal lesions were frequently observed in FA. Functional status of SCD: the severity of illness was significantly associated with the level of independence in each item of ADL. Activities not requiring dynamic balance were performed independently for a longer period than those requiring dynamic balance. Among SCD subtypes, functional prognosis was poorest in non-hereditary, multi-systemic types (OPCA, SDS and SND) followed by hereditary multi-systemic types (MHCA, DRPLA and MJD), and better in spinal types (FA and HSP) and cerebellar types (HHCA and LCCA).

Activities of Daily Living↗

PubMed1992

Accumulation of 99mTc-HM-PAO in photon deficient areas in bone scan of bone metastasis from hepatocellular carcinoma.

To evaluate bone metastasis from hepatocellular carcinoma (HCC), both bone and 99mTc-HM-PAO scintigraphies were performed in six patients with clinically and pathologically confirmed HCC. Two patients had a bone scintigram which revealed abnormal accumulation in the skull base, pelvic bone and thoracic spine. The 99mTc-HM-PAO scans of both these patients also showed abnormal accumulation in the same sites. The bone scintigrams in one patient revealed not only abnormal accumulation in the ribs but also photon deficient areas in the sternum, thoracic spine and femur, while 99mTc-HM-PAO scans showed abnormal accumulation in all these sites. In three patients, bone scintigraphy revealed photon deficient areas in the ribs, pelvic bone and femur, and their 99mTc-HM-PAO scintigrams showed abnormal accumulation in the same sites. Thus, it was shown that, in the detection of bone metastasis from HCC by means of bone scintigraphy, it was necessary to pay attention to hot and cold lesions, and that a combination study with 99mTc-phosphorous compounds and 99mTc-HM-PAO was useful in evaluating these lesions.

Aged↗