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Biomedical subjects

N Yoshimura

Publications and source records attributed to N Yoshimura.

At least 235 records · Page 13Linked to original sources
PubMed1998

[Two patients with hypertrophic cardiomyopathy showing regionally increased washout of 123I-MIBG from the thick myocardium].

123I-MIBG scintigraphy was performed in two patients with hypertrophic cardiomyopathy. These patients showed marked asymmetrical wall thickening in the left ventricle. The findings of 123I-MIBG scintigraphy in the thickened wall were regional increased washout and defect in the delayed images with preserved 201Tl uptake. This mismatched finding, which is correlated with ventricular tachycardia, gives useful information for follow-up of the patients with HCM.

3-Iodobenzylguanidine↗
PubMed1998

[Feature of screening-detected cancer and progress of treatment--esophageal cancer].

The recent increase in the detection of esophageal mucosal cancer has been changing the direction of treatment. The rate of esophageal cancer detection in mass screening by X-ray is 0.008%, which is 1/13 that of gastric cancer. Moreover, the rate by endoscopy is higher; the former is 0.1% and the later is 0.6%. Further, endoscopic screening using iodine staining for a high risk group like alcoholism has 3.6% detectability on esophageal cancer and 1.7% on gastric cancer. The rate of cancer-detection of upper intestinal organs comes to 5.35% in all. Most of the esophageal cancer detected by endoscopy is mucosal cancer, which is treatable by endoscopic mucosal resection (EMR). The result of the treatment is 100% 5 year-survival in cases of m1 and 2 esophageal cancer. EMR of esophagus-preserving treatment is truly effective for patients. Endoscopic examination using iodine staining for the high risk group is excellent for mass screening of esophageal cancer.

Adult↗
PubMed1998

[Chronic hypersensitivity pneumonitis due to isocyanate in a patient presenting with acute symptoms 1 month after environmental exposure].

A 51-year-old man who had been working for 10 years with polyurethane paint containing isocyanate (MDI) was admitted to our hospital with complaints of fever and exertional dyspnea. Fine crackles were heard in both bases, and the patient had clubbed fingers. A chest X-ray film and computed tomograms of the lungs revealed patchy infiltrative shadows in both lung fields and subpleural honeycombing associated with irregular linear areas. Examination of bronchoalveolar lavage fluid showed increased T lymphocytes and a decreased CD 4/8 ratio. Specimens obtained by transbronchial lung biopsy revealed lymphoplasmacytic infiltration into the thickened alveolar walls, macrophage accumulation, and micro-epithelioid cell granulomas in the alveolar sacs. Hypersensitivity pneumonitis was suspected although the causative antigen was not identified because the results of short-term environmental provocation tests were negative in the patient's home and workplace. After discharge, the patient continued working as a paint sprayer. His acute symptoms recurred 1 month after exposure to isocyanate. Similar episodes occurred on two separate occasions. In addition, the patient tested positive for antibody to MDI-HSA in bronchoalveolar fluid. From the above observations, the patient was given a diagnosis of chronic hypersensitivity pneumonitis due to isocyanate (MDI). This condition is extremely rare. Furthermore, it is interesting that acute symptoms recurred 1 month after environmental exposure to the causative antigen.

Alveolitis, Extrinsic Allergic↗
PubMed1998

[Pulmonary edema due to acute airway obstruction immediately after tracheal extubation].

A 33-year-old male was scheduled for tonsillectomy and pharyngoplasty due to sleep apnea syndrome. The intubation was uneventful following induction with thiamylal and vecuronium. Anesthesia was maintained with O2-N2O-sevoflurane. No complications were observed during the 90 min operation. After the termination of the anesthesia, a hyperadrenergic state was observed: arterial pressure and heart rate rose to 230/135 mmHg and 135 bpm, respectively. Immediately after extubation, he developed dyspnea with tracheal tag and stridor, and became cyanotic despite the use of a simple oxygen mask and assisted ventilation. Laryngospasm was suspected. The patient was reintubated and suctioned; pink, frothy sputum was not obtained. Arterial blood gases 5 minutes after reintubation revealed a pH of 7.24, Pao2 86 mmHg (FIo2 1.0), and Paco2 54 mmHg. Chest X-ray 30 minutes after reintubation revealed bilateral diffuse alveolar infiltration. The diagnosis was interstitial pulmonary edema. The patient was ventilated mechanically by applying a positive end-expiratory pressure of 5cm H2O, and furosemide and dopamine were administered intravenously. The patient was extubated the next day, and discharged from hospital ten days later. We considered that the lung edema was induced by the severe negative pressure generated by inspirating against a closed upper airway, as well as by the hyperadrenergic state and severe hypoxemia observed during and after extubation.

Acute Disease↗
PubMed1998

[Difference between transcortical sensory aphasia following the left frontal lesion and transcortical sensory aphasia following the left posterior lesion].

We assessed the difference between transcortical sensory aphasia (TCSA) following the left frontal lesions (F-TCSA) and TCSA following the left posterior lesions (P-TCSA). All the patients were right-handed and the 7 patients had the lesions in the only frontal lobe and the 10 patients had the lesions only in the left temporo-parieto-occipital regions. We administered pointing tasks, using 90 line drawings representing single nouns. We presented 6 line drawings a pointing board, and we used two kinds of pointing boards: one showed the line drawings each belonging to different categories (random categorized pointing task), the other showed the line drawings each belonging to only either two different categories (two categorized pointing task) and we presented 15 pointing boards each alternatively. The result was that regarding the patients of P-TCSA showed different number of correct answers between the random categorized pointing task and the two categorized pointing task with statistical significance. Regarding the patients of F-TCSA showed no difference between them. The results indicated that disturbance of P-TCSA on the pointing task was the disturbance of semantic process per se. And the disturbance of F-TCSA on the pointing task was that of not only semantic process but also the whole process including comprehending the presented words, searching the line drawings, comparing the line drawings with the presented word and final selection, which demanded persistent multiple memory process consistent with working memory.

Aphasia, Wernicke↗
PubMed1997

Plasticity of Na+ channels in afferent neurones innervating rat urinary bladder following spinal cord injury.

1. Whole-cell patch-clamp recordings in combination with axonal tracing techniques were used to investigate the effects of chronic spinal cord injury on the electrical properties of dorsal root ganglion neurones innervating the urinary bladder or colon of the adult rat. 2. In spinal intact animals, the majority (73-74%) of bladder and colon neurones which were small in size exhibited high-threshold humped spikes mediated by tetrodotoxin (TTX)-resistant Na+ channels, whereas large neurones had low-threshold narrow spikes mediated by TTX-sensitive Na+ channels. 3. In chronic spinal transected animals, 60% of bladder afferent neurones exhibited TTX-sensitive low-threshold spikes. The average diameter and input capacitance of the cells were significantly larger than those of cells obtained from spinal intact animals. 4. In bladder afferent neurones from chronic spinal transected rats, the density of TTX-resistant Na+ currents significantly decreased from 60.5 to 17.9 pA pF-1, whereas that of TTX-sensitive currents increased from 32.1 to 80.6 pA pF-1. 5. These changes in action potential and Na+ current characteristics were not detected in colon afferent neurones following spinal cord injury. 6. The results indicate that spinal cord injury increases bladder afferent neurone excitability by shifting the expression of Na+ channels from a high-threshold TTX-resistant type to a low-threshold TTX-sensitive type. This change in properties may occur in response to alterations in neurotrophic signals originating in the hypertrophied bladder.

Action Potentials↗
PubMed1997

A novel gene suppressed in the ventricle of carnitine-deficient juvenile visceral steatosis mice.

In order to clarify the pathogenesis and pathophysiology of cardiac hypertrophy in carnitine-deficient juvenile visceral steatosis (JVS) mice, we performed mRNA differential display analysis with total RNA extracted from the ventricles of control and JVS mice at 14 days of age. We identified four up-regulated genes, two known and two unknown, and a novel down-regulated gene. Northern blot analysis with a novel cDNA probe derived from the down-regulated gene fragment 8A2 revealed three mRNA species of 1.1-, 1.3-, and 2.6-kb. The 1.1- and 1.3-kb mRNA species were found only in the heart, and the 2.6-kb species was found in the heart, kidney and brain, but not in skeletal muscle or liver. The 1.1- and 1.3-kb species were down-regulated in the ventricles of JVS mice, but not in the auricles, and increased to the control level with carnitine treatment. We isolated cDNA clones from ventricle RNA, termed CDV-1 (carnitine deficiency-associated gene expressed in ventricle) and from brain RNA, termed CDV-1R (CDV-1-related gene) by 5'- and 3'-RACE analyses. The entire nucleotide sequence except the 5'-terminal 64 bp of CDV-1 cDNA was completely identical to the 992 bp sequence from the 3'-end of CDV-1R cDNA. The CDV-1 cDNA contained an open reading frame predicting a peptide of 107 amino acids, which composed the C-terminal portion of CDV-1R peptide consisting of 414 amino acids.

Amino Acid Sequence↗
PubMed1997

The central neural pathways involved in micturition in the neonatal rat as revealed by the injection of pseudorabies virus into the urinary bladder.

Pseudorabies virus was injected into the wall of the urinary bladder in 2- and 12-day-old rats in order to examine developmental changes in the central neural pathways controlling micturition. Forty-eight hours after virus injection, virus-labeled neurons were identified in the lumbosacral spinal cord but not in the brain. Sixty to seventy-two hours after virus injection in both 2- and 12-day-old rats, infected neurons were detected in Barrington's nucleus, nucleus paragigantocellularis, nucleus reticularis gigantocellularis, A5 area, nucleus raphe obscurus, locus subcoeruleus, periaquaductal gray, red nucleus, paraventricular nucleus and cerebral cortex. These results in neonatal rats are similar to those reported in adult rats. Thus, it is likely that the supraspinal neural circuitry which underlies micturition in the adult animal is already organized in the neonatal rat during the early postnatal period even though the supraspinal micturition reflex pathway does not become functional until the third postnatal week.

Aging↗
PubMed1997

Electron microscopic immunohistochemistry of ocular and extraocular pseudoexfoliative material.

To investigate the nature of extraocular pseudoexfoliative (PSX) material, and to validate the hypothesis that the PSX syndrome is a systemic disorder, we studied the immunoreactivity of intraocular and extraocular PSX material from patients with the PSX syndrome using antibodies against proteins of extracellular matrices. Surgical specimens of four different tissues were obtained from human eyes with the PSX syndrome: nine trabecular tissues, three cataractous lenses, six bulbar conjunctivas, and seven lid skins. These tissues were processed for electron microscopic immunohistochemistry, and stained with antibodies against vitronectin, fibronectin, laminin, and elastin, by an indirect immunogold procedure. Density of the gold particles located on the PSX material was estimated by video image analysis. Statistical analysis of the data revealed that the PSX material from trabecular tissues, lenses, bulbar conjunctivas, and lid skins had almost identical immunoreactivity to the antibodies studied. PSX materials of trabecular tissues, lenses, bulbar conjunctivas, and lid skins were found to have not only a similar ultrastructure, but also almost identical immunohistochemical characteristics. These results support the hypothesis that the PSX syndrome is a systemic disorder.

Aged↗
PubMed1997

Diagnosis of intraocular lymphoma by polymerase chain reaction.

BACKGROUND: Cytopathological examinations have been used in the diagnosis of intraocular lymphoma. However, sometimes it is not easy to detect malignant cells in the biopsy specimens. We applied a method that identified monoclonal proliferation of B lymphocytes by using polymerase chain reaction (PCR) in the diagnosis of patients suspected to have intraocular B-cell lymphoma. METHODS: Three specimens of the diagnostic vitrectomy were studied by cytological examination and by PCR to amplify the complementary determining region (CDR3) of immunoglobulin heavy chain (IgH) gene. As a positive control, a biopsy specimen of an orbital lymphoma was examined; four vitrectomy specimens from patients with diabetic retinopathy, proliferative vitreo-retinopathy, acute retinal necrosis (ARN) and macular hole were negative controls. RESULTS: On cytologic examination, no malignant cells were found in three specimens: suspected intraocular lymphoma and one ARN. In contrast, a discrete band that reflected monoclonal proliferation of B lymphocytes was detected by PCR in specimens from two patients and the positive control. Vitrectomy specimens from the negative controls, including ARN, did not show a discrete band on PCR. CONCLUSIONS: Two cases of ocular malignant lymphoma were diagnosed by PCR identification of monoclonal proliferation of B lymphocytes. This method may be an additional diagnostic tool in the diagnosis of intraocular B-cell lymphoma.

Aged↗
PubMed1997

Cervical cord ependymoma with numerous microrosettes.

"Microrosette ependymoma," which is ependymoma with numerous microrosettes throughout the tumor, has rarely been reported. We describe an autopsy case of cervical cord ependymoma with two unusual features: the presence of numerous microrosettes and the formation of trabecular architecture. The tumor originated in the C2 segment of a man aged 23 years and gradually expanded over the following 15 years and 10 months until the entire cervical cord was involved. Beside the low grade of malignancy, the tumor cells exhibited a strong tendency to form microrosettes and trabecular architecture, which formed many perivascular pseudorosettes. The microrosettes mostly consisted of only two or a few more cells, in the absence of large rosettes. Thus the constituent cells were those forming perivascular pseudorosettes. Electron microscopy and immunohistochemistry characterized the ependymal properties of the microrosettes, whose lumina frequently contained fibril bundles similar to those of the Reissner's fiber fibrils, in addition to cilia and microvilli. The pathogenesis of the occurrence of numerous microrosettes is unknown; however, a defect in the mechanism of regulation of rosette formation and enlargement is the most likely explanation.

Adult↗
PubMed1997

Open distal anastomosis in retrograde cerebral perfusion for repair of ascending aortic dissection.

BACKGROUND: In patients with aortic dissection, a patent distal false lumen at long-term follow-up leads to complications. We investigated the feasibility of performing an open distal anastomosis using retrograde cerebral perfusion. METHODS: Over a 10-year period, 41 patients with acute type A aortic dissection underwent 43 surgical repairs. In 1991, an open distal anastomosis using retrograde cerebral perfusion (group 2) was introduced to replace the standard aortic cross-clamp method (group 1). The mean retrograde cerebral perfusion time was 47.3 minutes (range, 22 to 67 minutes), and there were no neurologic sequelae in surviving patients. RESULTS: The operative mortality rate was 18.5% in group 1 and 18.7% in group 2. At long-term follow-up, dilatation of the false lumen (more than 50 mm in diameter) occurred in 9 of 18 patients (50%) in group 1, and 2 patients died of aortic rupture. There were no deaths in group 2, and dilatation of the distal false lumen occurred in only 15.4% of patients (p < 0.05). CONCLUSIONS: The use of retrograde cerebral perfusion in patients with acute aortic dissection provides adequate time to perform a safe, open, distal anastomosis, and could decrease significantly the rate of enlarged, patent, false lumina.

Acute Disease↗
PubMed1997

Diabetic cystopathy: relationship to autonomic neuropathy detected by sympathetic skin response.

PURPOSE: The possible relationship between bladder dysfunction and autonomic neuropathy was investigated in unselected diabetic patients. MATERIALS AND METHODS: Bladder function was examined by cystometry in 53 unselected diabetic patients and 10 healthy controls. Sympathetic skin response was recorded in 23 of 53 patients and all control subjects to evaluate autonomic neuropathy associated with diabetes, and the results were compared to cystometric findings. RESULTS: Cystometrograms exhibited significant increases in bladder volume at first desire to void and maximal bladder capacity, and a decrease in detrusor contractility in diabetic patients compared to those in controls. In addition, mean residual urine was significantly larger in diabetic patients than in controls. Among the 53 diabetic patients these bladder dysfunctions were also found in each subset of patients with no sign of retinopathy (33), no subjective urinary symptoms (32) or duration of diabetes less than 1 year (12). In 23 patients in whom sympathetic skin response was measured 12 without sympathetic skin responses had increased residual urine and decreased detrusor contraction pressure. The remaining 11 patients with a lower amplitude of sympathetic skin response and more prolonged latency than controls had a significant decrease in detrusor contraction pressure. CONCLUSIONS: Bladder dysfunction, characterized by loss of sensation, increased capacity and decreased contractility, was the main observation of diabetic cystopathy regardless of the duration or severity of the disease. The association of bladder dysfunction and autonomic neuropathy detected by the sympathetic skin response might indicate that diabetic cystopathy is a manifestation of peripheral neuropathy induced by diabetes.

Adult↗
PubMed1997

Initial MRI findings of non-traumatic osteonecrosis of the femoral head in renal allograft recipients.

Fifty-one renal allograft recipients (15-62 years old, mean: 37 years) were monitored for 2.5-6.5 years (average: 4.3 years) after surgery by using magnetic resonance imaging (MRI) to find (i) initial signs of osteonecrosis of the femoral head (ONF), (ii) the presence of bone marrow edema as an initial sign of ONF, (iii) any changes of MRI patterns, and (iv) the relationship between these MRI findings and prognosis. MRI was performed preoperatively (baseline), and whenever possible during the 6-9th week, 12-16th week, 12th month, and yearly thereafter. T1- and T2-weighted images were obtained by using a spin echo technique. Abnormalities were first detected on MRI of 23 femoral heads in 13 patients between 6 weeks and 12 months. All lesions first showed a low intensity band on T1-weighted images and a high intensity band on T2-weighted images. No symptoms or diffuse patterns, such as bone marrow edema, preceded the appearance of the band pattern. After the 12th month, no new abnormal findings on MRI were detected. The lesions were classified into Type A, B, or C, according to the location. 12 of the 16 Type C femoral head lesions, which extend beyond the medial two thirds of the weight-bearing portion of the acetabulum, became symptomatic 7-14 months after transplantation and then progressed to collapse. Bone marrow edema appeared with radiological collapse and symptoms. With the exception of five lesions in three patients who failed to be MR imaged until 12 months postoperatively, all lesions were first detected on MRI within 16 weeks after transplantation. We therefore postulate that the ischemic event that causes ONF will have occurred within 12 weeks after transplantation, considering the time lag of reparative reaction to the dead bone.

Adolescent↗
PubMed1997

Case-control study of risk factors for hip fractures in the Japanese elderly by a Mediterranean Osteoporosis Study (MEDOS) questionnaire.

A case-control study of hip fracture among the Japanese elderly was carried out in order to assess the risk factors for fractures. On the data obtained from 249 cases and 498 controls matched with ethnicity, sex, age, and residential area, significant risk factors on the lifestyle by multivariate analyses included drinking more than three cups of coffee daily, living in rural areas in the past, sleep disturbance, stroke with hemiplegia, and sleeping in a (Western-type) bed. In contrast, in addition to possession of a large body mass index, moderate alcohol intake and eating fish appeared to be associated with a reduced risk of hip fracture. In conclusion, some traditional Japanese lifestyle characteristics may prevent hip fractures among the Japanese elderly.

Aged↗