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Y Tsuboi

Publications and source records attributed to Y Tsuboi.

At least 91 records · Page 5Linked to original sources
PubMed1995

[Clinical difference between "proximal" and "distal" type of cervical spondylotic amyotrophy].

We studied 31 patients with cervical spondylotic amyotrophy. Weakness and atrophy without prominent sensory changes were started from the proximal muscles in 16 patients (proximal type), and from the distal muscles in 15 patients (distal type). In both types, the age at onset of neurological symptom ranged from thirties to sixties, and men were more frequently affected than women. Distal type patients often presented cold paresis and/or postural finger tremor, which occasionally was the initial symptom. Two patients of proximal type had muscular atrophy extended to the distal end. None of distal type patients had extension of atrophy to the proximal muscles during a long course of their illness. Most patients of proximal type had neurogenic changes on electromyography extended to the distal muscles. Neuroradiologically, proximal type patients had a cord atrophy at C4/5 intervertebral level, and distal type had cord atrophy at C5/6,6/7. We assume that the responsible lesion for the cervical spondylotic amyotrophy is in anterior horn at C5-T1 cord level for the proximal type, and at C7-T1 for the distal type. Abnormal venous circulation within the cord may cause the selective involvement of the gray matter.

Adult↗
PubMed1994

Effect of interstimulus interval on perceived sensation and intradental nerve activity during thermal tooth stimulation in man.

The effect of interstimulus interval on nerve responses and subjective sensory ratings evoked by thermal stimulation of the teeth were studied in man. A total of 30 unitary discharges during heat stimulation of the lower incisor teeth were recorded from the inferior alveolar nerves using microneurographic technique. Fifteen of them had threshold sensory ratings above 3 (pain related-units) and 15 had ratings of less than 2 (non-pain-related units). Repetitive heat stimulation was applied to the teeth with interstimulus intervals of 180 s (ISI 180) and 30 s (ISI 30). Repetitive (ISI 180 and ISI 30) non-painful heat stimulation of the teeth did not alter either the intensity ratings or unitary discharge activities of non-pain-related units (P > 0.05). Repetitive painful heat stimulation of the teeth with ISI 180 did not alter the intensity ratings of pain-related units (P > 0.05), whereas that with ISI 30 significantly reduced the intensity ratings of pain-related units during a second session of heat trials (P < 0.05). On the other hand, repetitive heat stimulation of the teeth with ISI 180 caused a slight reduction in the firing frequency of pain-related units (P > 0.05). Repetitive painful heat stimulation with ISI 30 significantly reduced the firing frequency of pain-related units (P < 0.05).

Adult↗
PubMed1994

Therapeutic efficacy of the non-peptide AVP antagonist OPC-31260 in cirrhotic rats.

The present study was undertaken to determine whether a non-peptide arginine vasopressin (AVP) antagonist [5-dimethylamino-1-(4-(2-methylbenzoylamino)benzoyl]-2,3,4,5-tetra hydro-1H- benzazepine] (OPC-31260) improves the impaired water excretion in rats with experimental liver cirrhosis. Male Wistar rats weighing 200 to 250 g were injected in an equal volume (4 ml/kg) of carbon tetrachloride and olive oil at an interval of seven days for three months, causing liver cirrhosis with ascites. Control rats were injected with only olive oil. Body weight (body wt) and hematocrit (Hct) were lower in the cirrhotic rats than the control rats (body wt 360.7 vs. 238.5 g, P < 0.01; Hct 46.3 vs. 39.2%, P < 0.01). A water loading test (30 ml/kg) was carried out and 20-minute urine collections were made for three hours. The percent of water load excreted was 62.5% in the cirrhotic rats, a value significantly less than that of 102.1% in the control rats. However, its percent increased to 215.1% after the oral administration of 5 mg/kg OPC-31260 (P < 0.01). Minimal urinary osmolality (UOsm) was 185.5 mOsm/kg H2O in the cirrhotic rats receiving the vehicle, a value greater than the control rats of 125.5 mOsm/kg H2O (P < 0.01). The oral administration of 5 mg/kg OPC-31260 reduced minimal UOsm to 85.2 mOsm/kg H2O in the cirrhotic rats (P < 0.01). Urinary excretion of sodium was lower in the cirrhotic rats than the control rats (87.1 vs. 312.4 microEq/3 hr, P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

First isolation of a rickettsia closely related to Japanese spotted fever pathogen from a tick in Japan.

In May 1993, we collected unfed ticks in Anan, Tokushima Prefecture, Shikoku District, Japan, a highly endemic area of Japanese spotted fever (JSF). We isolated JSF rickettsiae from these ticks by inoculating tick-emulsions into L-929 cells. Of the four genera and seven species of ticks examined, only one larva of Dermacentor taiwanensis Sugimoto yielded a rickettsial isolate. The isolate (DT-1 strain) was found to belong to the serotype common to the causative agent of JSF. This was based on its specific reactivity to mouse antisera and to a monoclonal antibody to JSF rickettsiae from the Shikoku District. This is the first tick-borne spotted fever group of rickettsia isolated in Japan. However, all stages of D. taiwanensis infrequently parasitize humans. Some ticks in the genus Haemaphysalis commonly infest humans and are frequently found to be rickettsia-positive in the hemolymph test when using the monoclonal antibody mentioned above. Therefore, the vectors of JSF rickettsiae to humans may be a complex of tick species.

Animals↗
PubMed1994

Increased concentration of C4d complement protein in CSF in amyotrophic lateral sclerosis.

Plasma and CSF concentrations of C4d and the circulating immune complex to C1q were measured in 27 patients with amyotrophic lateral sclerosis (ALS) or cervical spondylosis. There was no significant difference among groups in plasma C4d or in plasma or CSF concentrations of the circulating immune complex to C1q. The ALS group, however, had a significantly higher CSF concentration of C4d than the group with cervical spondylosis, as well as a higher C4d index (CSF to plasma C4d ratio x serum to CSF albumin ratio). These results suggest that augmented complement activation in the CNS occurs in ALS. Increased CSF concentration of C4d or raised C4d index may serve as a basis for differentiating ALS from cervical spondylosis.

Adult↗
PubMed1994

Morphology of primary somatosensory cortical neurons receiving input from the tooth pulp.

1. To elucidate the morphological and electrophysiological characteristics of tooth pulp-driven neurons (TPNs) in the primary somatosensory cortex (SI), we injected neurobiotin into TPNs whose electrophysiological characteristics had been identified. 2. TPNs, responsive to electrical stimulation of the tooth pulp, were recorded intracellularly and injected from areas 3a and 3b of SI. A total of 58 TPNs in SI were successfully injected and reconstructed. Nineteen of these TPNs were located in area 3a and 39 in area 3b. Three area 3a TPNs were identified in lamina II, eight in lamina III, seven in lamina V, and one in lamina VI. Five 3b TPNs were identified in lamina II, 19 in lamina III, 7 in lamina IV, 7 in lamina V, and 1 in lamina VI. 3. Thalamic and tooth pulp latencies of lamina III and IV TPNs were shorter than those of lamina II and V TPNs. On the other hand, lingual and masseteric nerve latencies of TPNs were not consistent with thalamic and tooth pulp latencies. 4. Three of 19 area 3a TPNs and 7 of 39 area 3b TPNs were classified as pulp-specific TPNs, which received only tooth pulp input. Thirteen of 19 area 3a TPNs and 24 of 32 area 3b TPNs were classified as low-threshold mechanoreceptive TPNs, which responded to nonnoxious mechanical stimulation of the receptive field, and only 2 area 3b TPNs were classified as wide-dynamic range TPNs. Six of the area 3a TPNs and 14 of the area 3b TPNs responded to electrical stimulation of the lingual and/or masseteric nerves. Nociceptive-specific TPNs were not recorded in this study. 5. Lamina II TPNs in areas 3a and 3b had small somata, and those in area 3a had dendrites spreading into laminae I-II. Two TPNs in area 3a had axon collaterals extending into area 4. In contrast, area 3b TPNs in lamina II have dendrites spreading into laminae I-III. Their axons did not extend deeply into the subcortical regions, and the axon collaterals reached into area 3a. 6. Lamina III TPNs were classified according to their morphological characteristics as pyramidal or nonpyramidal stellate TPNs. Pyramidal lamina III TPNs had typical pyramidal somata, like those of lamina V pyramidal cells. Furthermore, those in areas 3a and 3b had dendrites with numerous spines spreading into laminae I-III, and some of the area 3a TPNs have axons with collaterals projecting into area 4. Lamina III area 3b TPNs had morphological properties similar to those in area 3a.(ABSTRACT TRUNCATED AT 400 WORDS)

Afferent Pathways↗
PubMed1994

Opposite changes in serum sodium and potassium in patients in diabetic coma.

We studied the changes in serum sodium (Na) and potassium (K) levels in seventeen patients in diabetic ketoacidosis and nine patients in non-ketotic hyperosmolar coma, who had marked hyperglycemia (707.4 +/- 75.6 mg/dl, mean +/- SEM) and dehydration. The disorder characterized two types of alteration. The one group was hyponatremia with hyperkalemia in 17 patients in diabetic ketoacidosis (132.9 +/- 2.0 and 5.7 +/- 0.2 mEq/l), and 4 patients in non-ketotic hyperosmolar coma (125.8 +/- 4.3 and 5.2 +/- 0.5 mEq/l). The other was hypernatremia (162.5 +/- 1.8 mEq/l) with hypokalemia (3.4 +/- 0.2 mEq/l) in 5 patients in non-ketotic hyperosmolar coma. Intensive therapy with insulin and fluid administration improved the diabetic hyperglycemia and associated abnormalities. The vectors showing the normalization of serum Na and K levels was in quite opposite directions between the patients with hyponatremia with hyperkalemia and those with hypernatremia with hypokalemia. The amounts of loss of circulatory blood volume exceeded 20% in three groups of patients, a loss greater in the hypernatremic patients than in the hyponatremic ones. These results indicate that serious body water depletion produces hypernatremia instead of hyponatremia in patients in diabetic coma. The disorder may be caused by the altered distribution of electrolytes between the intra- and extra-cellular spaces.

Adult↗
PubMed1994

In vivo diuretic effect of a new non-peptide arginine vasopressin antagonist, OPC-31260, in conscious rats.

The present study was undertaken to determine whether a non-peptide arginine vasopressin (AVP) antagonist (5-dimethylamino-1-[4-(2-methylbenzoylamino)benzoyl]-2,3,4,5-tetra hydro-1H- benzazepine; OPC-31260) antagonizes the antidiuretic action of endogenous and exogenous AVP in conscious rats. OPC-31260, given orally at a dose of 5 mg/kg or higher, increased urinary volume (UV) and reduced urinary osmolality (Uosm) in a dose-dependent manner, in rats acutely denied access to water. Minimal Uosm was obtained 1-2 h after oral administration of OPC-31260. OPC-31260 caused sustained water diuresis for more than 12 h when water was available ad libitum since OPC-31260 (30 mg/kg) reduced Uosm to less than 230 mOsmol/kg H2O, significantly less than the control value of 600 mOsmol/kg H2O. Water deprivation for 24 h increased plasma AVP levels to 7.2 pmol/l and increased Uosm to 2160 mOsmol/kg H2O. In such water-deprived rats, oral administration of OPC-31260 at 100 mg/kg was diuretic; it markedly increased free water clearance and decreased Uosm to 202 mOsmol/kg H2O. In homozygous Brattleboro rats (with inherited AVP deficiency), given free access to water, subcutaneous infusion of the V2 agonist 1-deamino-8-D-AVP (dDAVP) at a rate of 1 ng/h markedly decreased UV to 12.6 from 148.7 ml/day and increased Uosm to 1762 from 231 mOsmol/kg H2O. OPC-31260 (30 mg/kg) promptly increased UV and reduced Uosm to levels similar to those before the administration of dDAVP; repeated OPC-31260 treatment had sustained effects. These results indicate that OPC-31260 is an orally effective non-peptide AVP antagonist to the antidiuretic action of AVP in the conscious rat.

Animals↗
PubMed1994

An autopsy case of licorice-induced hypokalemic rhabdomyolysis associated with acute renal failure: special reference to profound calcium deposition in skeletal and cardiac muscle.

A 78-year-old man was hospitalized because of muscular weakness and acute renal failure. He had been taking glycyrrhizin (280 mg/day) for the last 7 years. Hypertension was noted in his history. Serum potassium was 1.9 mEq/l with metabolic alkalosis. There was hyporeninemic hypoaldosteronism. Serum enzymes, including GOT, LDH and CPK were markedly elevated. In addition, serum myoglobin was as high as 46 micrograms/ml with massive myoglobinuria. Oliguria occurred and blood urea nitrogen and serum creatinine rapidly elevated from 20.9 to 87 mg/dl and from 1.3 to 6.7 mg/dl, respectively. Profound calcium deposition was found in the damaged skeletal muscles, including the quadriceps femoris, axillar, neck, and cardiac muscles. These results indicate that licorice-induced pseudoaldosteronism produces hypokalemic rhabdomyolysis, resulting in acute renal failure and profound deposition of calcium into the damaged skeletal and cardiac muscles.

Acute Kidney Injury↗
PubMed1994

[Chronological changes in MR imaging of inferior olivary pseudohypertrophy--report of two cases].

Olivary pseudohypertrophy (OH) and its chronological change was examined by MR images in two patients with brainstem vascular disease. Patient 1 was a 63-year-old woman who developed an infarction in the red nuclei associated with "top of the basilar" syndrome. Two months later, she showed 2-4 c/s rhythmic myoclonus (rubral tremor) involving four extremities. Palatal myoclonus was absent. MR images of the inferior olives did not demonstrate a significant lesion in 10 days after the onset, but showed OH in 6 months, and then their size attained a maximum in 10 months after. On T2-weighted (T2) images and proton-density-weighted (PD) images obtained at 20 and 24 months, OH gradually became irregular but discrete in their intensity, and the intensity had also decreased to some extent. Rhythmic myoclonus had subsided to some extent after 20 to 24 months. Patient 2 was a 62-year-old woman who had a small hemorrhage in the pontine tegmentum. She developed 2.5 c/s vertical ocular myoclonus without palatal myoclonus two months after the onset. MR images showed OH in 6 and 8 months after the onset. On T2 and PD images obtained at 20 months, the image of OH gradually developed to become irregular in intensity and slightly atrophic in size. The ocular myoclonus somewhat reduced in their intensity 12 months after the onset. These serial changes in MR images were considered to correspond to the chronological changes of the pathology of OH. Appearance and subsidence of the myoclonic movement was also considered to correlate to the sequential changes of MR images of OH.

Cerebrovascular Disorders↗
PubMed1993

Response properties of primary somatosensory cortical neurons responsive to cold stimulation of the facial skin and oral mucous membrane.

The distribution and response characteristics of the primary somatosensory cortical (SI) neurons activated by cold stimulation of the facial skin and oral mucous membrane were studied in cats. The discharge activities of 53 cold-sensitive SI neurons that responded to a decrease in temperature of the facial skin and/or oral mucous membrane were recorded. Each of these neurons was classified according to its responsiveness to mechanical stimulation as follows: LTM (low-threshold mechanoreceptive, 14/53), WDR (wide dynamic range, 39/53) and NS (nociceptive-specific, none identified). Encoding and non-encoding SI cold-sensitive neurons were identified, according to their responsiveness to decremental thermal stimulation. Only 14 cold-sensitive SI neurons demonstrated increased firing frequencies when subjected to incremental stimulus intensity increases and were classified as the encoding-type, whereas 39 non-encoding-type neurons did not.

Animals↗
PubMed1993

Therapeutic efficacy of non-peptide ADH antagonist OPC-31260 in SIADH rats.

The present study was undertaken to determine whether the non-peptide V2 antidiuretic hormone (ADH) antagonist 5-dimethylamino-1[4-(2- methylbenzoylamino)benzoyl]-2,3,4,5-tetrahydro-1H-benzazepine (OPC-31260) normalized hyponatremia in rats with an experimental syndrome of inappropriate secretion of ADH (SIADH). Rats were administered V2 agonist 1-deamino-8-D-arginine vasopressin (dDAVP) subcutaneously at a rate of 5 ng/hr using an osmotic minipump and a 40 ml/day liquid diet. Serum sodium levels (SNa) and serum osmolality (SOsm) markedly decreased to 119 mEq/liter and 249 mOsm/kg H2O, respectively, 48 hours after the start of dDAVP administration. Hyponatremia persisted in a similar magnitude during the observation period of 14 days. On days 7 to 13 OPC-31260, administered 5 mg/kg per day orally, promptly raised SNa and SOsm to 134 mEq/liter and 282 mOsm/kg H2O in half a day, respectively, followed by the normalization of SNa and SOsm during the rest of the observation period. The cease of administration of OPC-31260 again decreased SNa and SOsm in rats receiving dDAVP. In contrast, SNa and SOsm were within the normal values in rats receiving 0.15 M NaCl, a vehicle for dDAVP, in the presence or absence of OPC-31260. The administration of OPC-31260 promptly caused marked water diuresis on day 7 in the hyponatremic rats receiving dDAVP, namely 5 mg/kg OPC-31260 markedly increased urinary volume and decreased UOsm. These results indicate that there is dilutional hyponatremia in rats receiving dDAVP and 40 ml/day liquid diets, and that OPC-31260 is an effective therapeutic for hyponatremia associated with dDAVP-induced SIADH.

Animals↗
PubMed1993

Characterization of ehrlichial organisms isolated from a wild mouse.

An infectious agent was isolated from the enlarged spleen of a wild mouse, Eothenomys kageus, by intraperitoneal inoculation of the spleen homogenate into laboratory mice. The laboratory mice developed splenomegaly, and the agent was maintained by serial passage of spleen homogenates in laboratory mice. The agent in the spleen homogenate was inactivated after incubation at 37 or 50 degrees C. Tetracyclines were effective in preventing infection of mice with this agent, but penicillin and sulfonamides were ineffective. Cytoplasmic inclusion bodies were observed in the peritoneal macrophages of infected mice. Electron microscopy revealed numerous small pleomorphic cocci within membrane-lined vacuoles in the cytoplasm of splenic macrophages. Morphologically similar to the ehrlichial organisms, each organism was surrounded by a distinct plasma membrane and rippled outer cell membrane without a distinct peptidoglycan layer. The agent did not grow in chicken embryos, and the Weil-Felix test result was negative. In the indirect fluorescent-antibody test, the agent reciprocally cross-reacted with Ehrlichia canis and cross-reacted somewhat with Ehrlichia sennetsu but did not cross-react with Ehrlichia risticii, Neorickettsia helminthoeca, Rickettsia tsutsugamushi, or Chlamydia spp. The mouse antiserum against this agent reacted with 64-, 47-, 46-, 44-, and 40-kDa proteins of E. canis by Western blotting (immunoblotting). Since E. canis and closely related Ehrlichia chaffeensis and Ehrlichia ewingii are not known to proliferate or cause splenomegaly in mice, these results suggest that the agent is a new species within the tribe Ehrlichieae of the family Rickettsiaceae. The finding suggests that wild rodents may serve as reservoirs for pathogenic ehrlichiae.

Animals↗
PubMed1993

Identity of pathogenic strains of spotted fever rickettsiae isolated in Shikoku District based on reactivities to monoclonal antibodies.

Three IgG (B2, C3 and F8) and two IgM (S3 and X1) monoclonal antibodies (Mab) were produced in BALB/c mice immunized with Aoki strain of spotted fever (SF) rickettsiae in Tokushima Prefecture, Japan. Of these, two (B2 and C3) reacted equally with six Japanese strains including YH strain, the prototype of R. japonica, but did not react with the foreign strains. These results indicate that SF rickettsial strains from Tokushima Prefecture were identified as R. japonica, and that the SF strains isolated at least in Shikoku District most likely belong to a common serotype.

Aged↗
PubMed1993

[Long-term artificial ventilation by nasal intermittent positive pressure ventilation; 6 cases of domiciliary assisted ventilation].

Six patients with chronic respiratory failure associated with hypercapnia were treated with nasal intermittent positive pressure ventilation (NIPPV) at home. NIPPV was delivered via a custom molded nasal interface described by McDermott. The patients consisted of one patient with kyphoscoliosis, three with Tb-sequela, one with COPD, and one with neuromuscular disease. Each patient had been treated with oxygen therapy until assisted ventilation was initiated because of CO2 retention. NIPPV was administered using a volume cycled flow generator set to deliver a minute volume such that PaCO2 was maintained between 35 and 45 Torr on NIPPV trial performed during wakefulness under the condition of no leakage from the mask. Supplementary oxygen was added so that oxygen saturation was maintained above 90 percent during more than 95% of nighttime NIPPV. Arterial blood gas tensions during daytime spontaneous breathing showed an improvement (PaCO2 68.3 +/- 7.2 Torr, PaO2 70.4 +/- 15.5 Torr, SaO2 91.6 +/- 4.3% before treatment; PaCO2 55.8 +/- 4.7 Torr, PaO2 87.5 +/- 16.5 Torr, SaO2 95.5 +/- 1.7% on treatment, mean +/- SD). The duration of NIPPV at home ranged from 2 to 24 months (11.7 +/- 6.8), and there was no hospitalization due to exacerbation during this period. In conclusion, NIPPV via a custom molded mask is simple, noninvasive, and suitable for the provision of long-term and domiciliary assisted ventilation.

Adult↗