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Biomedical subjects

T Imai

Publications and source records attributed to T Imai.

At least 775 records · Page 43Linked to original sources

Asymptomatic ulnar neuropathy in carpal tunnel syndrome.

Quantitative assessment of the vibration threshold of the second and fifth fingertips at 125Hz was performed on 28 affected limbs of 17 patients with carpal tunnel syndrome (CTS) together with a median and ulnar sensory nerve conduction velocity (SNCV) study. Twenty-six limbs of 26 age-matched healthy subjects were used as controls. Both the vibration threshold elevation of the second finger and the delay of median SNCV were significant in CTS patients as compared with controls (p less than .001). Although the ulnar SNCVs of all affected limbs were within the normal range, ten affected limbs (36%) were found to have a concomitant vibration threshold elevation of the fifth finger, and eight of those limbs were found to be exposed to chronic occupational mechanical stimulation at the wrist. These findings appear to support the presence of subclinical traumatic damage to the ulnar nerve at the wrist. In summary, digital vibration measurement can elucidate subclinical ulnar neuropathy in CTS which cannot be detected by SNCV studies.

Action Potentials↗

[Two cases of X-linked ichthyosis associated with myopathies].

X-linked ichthyosis is an inborn error of metabolism due to the deficiency of steroid sulfatase. We reported two cases of the patients associated with myopathies, which are Duchenne muscular dystrophy (DMD) and myotonic dystrophy (MyD), respectively. In addition to DMD and MyD, they showed corneal opacities, lack of steroid-sulfatase activities in peripheral leukocytes and massive accumulation of cholesterol sulfate in plasma. Such cases were not reported, previously. Assay of steroid sulfatase and cholesterol sulfate in the patients having ichthyosis is important to elucidate the wide clinical spectrum of steroid sulfatase deficiency.

Adult↗

[A case of thoracic neurilemoma with neurilemomas of the upper limb and sacrum].

A 64-year-old male was admitted in February 24, 1988 because of an abnormal shadow on chest X-ray. The tumor in the thoracic wall was removed at the thoracotomy and histology showed neurilemoma. Aspiration biopsy of tumors on the left upper limb and sacrum revealed the typical histopathologic appearance of neurilemomas. The possibility of malignant transformation and sequential appearance of tumors in patients with a neurilemoma indicates that complete resection and thorough follow-up examination are important.

Humans↗

[The role of neutrophils in airway hyperresponsiveness in dogs after ozone exposure].

To determine whether neutrophils are involved in airway hyperresponsiveness after ozone exposure, we studied the effect of neutrophil depletion by cyclophosphamide treatment on ozone-induced airway hyperresponsiveness in seven dogs. Airway responsiveness to inhaled methacholine was determined by modified Astograph (7 Hz oscillation method), and the numbers of neutrophils in the peripheral blood, total cell counts and differential cell counts in BALF were measured before and after ozone exposure, and after ozone exposure of dogs undergoing cyclophosphamide treatment. Ozone exposure was carried out for 2 hrs at an ozone level of 3.07 +/- 0.01 ppm (mean +/- SE), and cyclophosphamide (10 mg/kg) was given intravenously daily for five days starting six days before ozone exposure. There was a significant increase in airway responsiveness to inhaled methacholine after ozone exposure in the seven dogs (p less than 0.001), and the numbers of neutrophils in the peripheral blood and the neutrophil counts in BALF increased significantly after ozone exposure (p less than 0.01). After ozone exposure of dogs undergoing cyclophosphamide treatment, the numbers of neutrophils in the peripheral blood decreased significantly (p less than 0.001) and the neutrophil counts in BALF did not increase, but the airway responsiveness to inhaled methacholine increased significantly (p less than 0.01). There was no significant correlation between the degree of the increase in airway responsiveness and the degree of the increase in neutrophil counts in BALF after ozone exposure. These results suggest that neutrophil infiltration into the airway is not necessary for an increase in airway responsiveness after ozone exposure in dogs.

Airway Resistance↗

Improved dissolution and absorption of drugs using low molecular gelatin.

Kneaded mixtures of a basic drug, meclizine dihydrochloride (MZ), and a neutral drug, prednisolone (PN), with low molecular gelatin at the weight ratio of 1:1 were prepared, and their in vitro dissolution and in vivo absorption behaviour were examined. The dissolution rate of drugs from the kneaded mixtures was significantly faster than that of the drugs themselves. The low molecular gelatin enhanced the dissolution rate of MZ and PN by improving the wettability of the drug particles without any interaction in solution and the solid state. After oral administration of the kneaded mixture to beagle dogs, the initial serum concentration was significantly higher than that of the drug alone. However, the AUC value of the drug from the kneaded mixture was almost same as that of drug alone.

Excipients↗

[Surgical treatment of chronic empyema and postoperative pulmonary function].

Pulmonary function was evaluated in patients who were operated on for chronic empyema between October 1973 and October 1988. Fourteen patients underwent decortication, 61 were treated by the Kinchu method, 20 were treated by muscle flap and thoracoplasty, and one underwent pleuropnemonectomy. With decortication or the Kinchu method, significant postoperative improvement was noted in both percent forced vital capacity and FEV1/predicted initial capacity. However with muscle flap and thoracoplasty, percent forced vital capacity decreased. Ventilation and perfusion lung scan showed that pulmonary function improved in patients with good re-expansion of the lung who had suffered from short term lung collapse and no pathological changes in collapsed lung parenchyma.

Chronic Disease↗

[Surgical experience of bronchogenic early squamous cell carcinoma detected by sputum cytology in lung cancer screening].

Eighty-one patients of roentgenologically occult lung cancer (all men, and squamous cell carcinoma) were detected by sputum cytology in lung cancer screening of "Miyagi Program". Sixty-seven patients were resected surgically, and sixty-four of them underwent absolutely curative resection. In fifty-six patients, carcinoma did not penetrate the bronchial wall, and all of them were free from lymph node involvement. In eleven patients, carcinoma penetrated the bronchial wall, and three of them were proved to have lymph node involvement. For that reason, carcinoma which did not penetrate the bronchial wall and was free from lymph node involvement, was defined as early squamous cell carcinoma. Fourty-two early squamous cell carcinoma were located on segmental or more proximal bronchi, but twelve were located on subsegmental or more peripheral bronchi. Five-year survival of fifty-six patients with early squamous cell carcinoma were 91.8%, seven of fifty-six early squamous cell carcinoma patients were multicentric, which were detected synchronously in four cases, postoperatively in two cases, and both synchronously and postoperatively in one case. Two of three postoperatively detected cases were resected surgically and alive without cancer. These results indicate the validity of surgical treatment for roentgenologically occult squamous cell carcinoma. As the most serious prognostic problem is multicentricity, careful localization of primary lesion and postoperative intensive follow-up should be considered.

Aged↗

[Morphological observation of the mitral annulus fibrosus in patients with mitral valve prolapse].

Sixteen cases of mitral valve prolapse (MVP) with mitral regurgitation (MR) in the aged (mainly in their eighth and ninth decades) with both clinical and pathological evidences were investigated. One hundred autopsy cases served as the control. The longitudinally-sectioned mitral annulus fibrosus was pathologically studied in all with special reference to the atrium-valve disjunction reported by Hutchins. Morphologically, the mitral annulus fibrosus was classified either as type A (the mitral valve attaches to the left ventricle), type B (the mitral valve attaches to the left atrium: Hutchins' disjunction), type C (the atrialis continues to the left atrium and the fibrosa to the left ventricle), or type D (mitral annulus calcification). Type B was observed in only 31% of the MVP cases, whereas it was seen in 43% of the control cases. It was concluded that Hutchins' observation could not be regarded as the characteristic pathological finding of MVP.

Aged↗

Effect of the binding of bilirubin to either the first class or the second class of binding sites of the human serum albumin molecule on its photochemical reaction.

The kinetics of the photochemical changes of bilirubin were studied at a constant concentration of bilirubin bound either to the first class or to the second class of binding sites of the human serum albumin molecule. The more the bilirubin binds to the first class of binding sites in the human serum albumin molecule, the more readily geometric photoequilibrium to give (ZE)-bilirubin takes place. The more the bilirubin binds to the second class of binding sites or allosterically transformed binding sites induced by added SDS, the more readily structural photoisomerization, i.e. the formation of (EZ)-cyclobilirubin, takes place. When the serum bilirubin concentration is at low, safe, values bilirubin binds exclusively to the first class of binding sites and serves as an antioxidant [Onishi, Yamakawa & Ogawa (1971) Perinatology 1, 373-379]; at these concentrations human serum albumin protects bilirubin from irreversible photodegradation by only allowing readily reversible geometric photoisomerization. As the serum bilirubin concentration increases to high, and potentially dangerous, values, bilirubin binds to the second class of binding sites, and under these conditions human serum albumin seems to promote the photocyclization of bilirubin. During irradiation human serum albumin seems to act by retaining low, useful, concentrations of bilirubin while facilitating irreversible photoisomerization of excess bilirubin.

Bilirubin↗

Binding of pirprofen to human serum albumin studied by dialysis and spectroscopy techniques.

The interaction of pirprofen with human serum albumin (HSA) was investigated by equilibrium dialysis and spectroscopic (UV absorption, fluorescence, CD, NMR) techniques. It was found that HSA binds pirprofen nonstereospecifically. The binding of pirprofen depends upon the N-B conformational change of albumin. Chloride ions appear to displace the drug from its binding site. The thermodynamic parameters suggest that the interaction may be explained by electrostatic as well as hydrophobic forces. The absorption spectral changes which accompanied the binding of pirprofen to HSA implied that the aromatic portion of drugs was inserted into the hydrophobic crevice in the protein, while the carboxyl group of the drug interacted with a cationic site on the albumin surface. The NMR data indicated that the pyrroline ring and propionic acid parts may be the major binding site for HSA. A specific binding site for pirprofen on the HSA was found to be site II, benzodiazepine site, using fluorescence probes and drug markers. In addition, from the binding data with modified HSA, it seems that Tyr-411 is specifically involved in pirprofen binding.

Anti-Inflammatory Agents, Non-Steroidal↗

Transcription in the reverse orientation at either terminus of the adenovirus type 5 genome.

The right terminus of the adenovirus type 5 (Ad5) genome, which contained the early-region 4 (E4) promoter, was capable of initiating transcription in the reverse orientation in in vitro and in vivo assays. Multiple cis-acting elements, required for original-oriented transcription, were also important for reverse-oriented transcription except for the original TATA box. We constructed a plasmid in which the E4 promoter region was linked to the chloramphenicol acetyltransferase gene in the original orientation and linked to the lacZ gene in the reverse orientation and tested the ability of a co-transfected E1A gene to stimulate transcription in both orientations. Activities of transcription in both orientations were stimulated 6- to 10-fold in this assay. More than one cis-acting element was necessary for the stimulation. The region between -39 and -177 was necessary for the E1A-mediated trans-activation of transcription in both orientations, indicating that the region functioned in a bidirectional manner. The activity of transcription in the reverse orientation was similarly detected at the left terminus of the Ad genome and the activity was stimulated several-fold by E1A gene products.

Adenoviridae↗

Adult-type citrullinemia.

An autopsy case of adult-type citrullinemia in a 42-year-old male is reported. The patient neuropathologically presented mixed cerebral changes consisting of the pseudoulegyric and ischemic types of hepatocerebral disease. In common with previously reported cases of the pseudoulegyric type, the nature and localization of the cerebral changes in this case were characteristic, in that neuronal loss occurred most severely and symmetrically in the mediobasal part of the frontal and occipital lobes, gyrus cinguli, claustrum, insula and temporal lobe, and that the watershed area of the cerebral cortex, basal ganglia and Purkinje cells were only slightly affected. The importance of hypercitrullinemia was stressed in the pathogenesis of the cerebral changes evident in adult-type citrullinemia.

Adult↗

Acute ventilatory failure in multiple sclerosis.

Life-threatening acute ventilatory failure has been considered to be a very rare manifestation of multiple sclerosis (MS) and only a few cases have been investigated clinicopathologically. We examined 4 patients with MS who developed acute ventilatory failure, accompanied by a constellation of neurological symptoms and signs that were consistent with midline ventral medullary lesions. All but one of them survived the episode with artificial ventilation over a period of 9-11 days. One of the remaining 3 patients died a year later from subsequently developed anoxic encephalopathy. Neuropathological examination of the 2 deceased cases revealed the suspected lesions in the medulla as well as widespread chronic and active MS foci, which were characterized by largely necrotic changes rather than by pure demyelination. MRI in another case revealed a lesion in the caudal medulla. The apparently not so rare occurrence of ventilatory failure among Japanese MS patients might be related to the known differences in pathological features between Japanese and Western MS patients. Since there is a good chance of recovery, early recognition of the symptom complex appears important in the assessment and treatment of such patients.

Adult↗

Epithelium-lined cyst of the pretectal region: case report and electron microscope study.

Ultrastructural findings of an epithelium-lined cyst in the left pretectal region are reported. A 38-year-old woman developed a sensory disturbance on her right side and blurring of vision. Computed tomography scans and magnetic resonance images disclosed a round cystic lesion in the left pretectum. Light microscopically, the cyst was found to be lined by a single layer of cuboidal epithelial cells. Electron microscope examination revealed that the epithelial cells of the cyst possessed clear nuclei, abundant tonofilaments, and glycogen granules, featured as well as the usual organellae. The free surface of the epithelial cells had numerous finger-like microvilli with coating materials. These cells were interconnected by well-developed desmosomes and interdigitations, and also possessed basal lamina materials on the basal surface. These cytological features suggest a heterogenous origin of the cells rather than a neuroepithelial one.

Adult↗

Spectroscopic study of the interaction of coumarin anticoagulant drugs with polyvinylpyrrolidone.

The interaction of coumarin anticoagulants with polyvinylpyrrolidone (PVP) was investigated using a fluorescence technique. The fluorescence intensities of warfarin and phenprocoumon were greatly enhanced following binding to PVP, while the fluorescence of 4-hydroxycoumarin was little enhanced in the presence of PVP. The enhanced fluorescence of warfarin and phenprocoumon bound to PVP can be explained by their incorporation into the hydrophobic environment in the PVP and by a decrease in the internal rotation of the alpha-substituted benzyl group in the drugs. The binding parameters of warfarin and phenprocoumon were estimated by the Klotz method; the binding constants for phenprocoumon and warfarin were found to be 2.6 X 10(4) and 2.2 X 10(4) M-1, respectively. The 13C-NMR measurements suggest the lactone moiety in the 4-hydroxycoumarin and the substituted benzene ring play an important role in the binding to PVP.

4-Hydroxycoumarins↗

Drug binding to alpha 1-acid glycoprotein studied by circular dichroism.

The interactions of acidic and basic drugs with alpha 1-acid glycoprotein (alpha 1-AGP) were investigated using circular dichroism (CD) measurements. Extrinsic Cotton effects were generated by the binding of drugs to alpha 1-AGP. The CD data suggested the presence of a single binding site on the alpha 1-AGP molecule. The induced ellipticities of the acidic drug-alpha 1-AGP system decreased with increasing pH, while the ellipticities for the basic drugs increased with pH. The ellipticities for all drugs were reduced by the addition of fatty acids. Furthermore, the induced ellipticities decreased in the presence of cesium chloride for basic drugs bound to alpha 1-AGP. The extrinsic Cotton effects therefore appear to result from hydrophobic interaction with alpha 1-AGP for the acidic drugs and from hydrophobic and electrostatic interactions for the basic drugs.

Acenocoumarol↗