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Biomedical subjects

Y Nishimura

Publications and source records attributed to Y Nishimura.

At least 721 records · Page 40Linked to original sources

Totally synthetic analogues of siastatin B. II. Optically active piperidine derivatives having trifluoroacetamide and hydroxyacetamide groups at C-2.

Siastatin B analogues, optically active 2-(trifluoroacetamide)- 3,4,5-trihydroxypiperidines having nitromethyl, aminomethyl and carboxyl branched groups at C-5, and (+)-(2R,3R,4R,5R)-5-(aminomethyl)-3,4,5-trihydroxy-2- (hydroxyacetamido)piperidine have been obtained total synthetically from D-ribono-1,4-lactone. Some analogues have inhibitory activity against some glycosidases, and (+)-(2R,3R,4R,5R)-2-(trifluoroacetamido)-3,4,5-trihydroxypiperi dine-5-carboxylic acid showed a marked inhibitory activity against beta-glucuronidase.

Anti-Bacterial Agents↗

Stability difference between DNA and RNA mini-hairpins containing two G-C pairs.

The deoxyribonucleotide fragments, d(GCGAAAGC) and d(GCGAAGC) form extraordinarily stable mini-hairpin structures containing only two G-C pairs. In contrast, the corresponding ribonucleotide fragments, r(GCGAAAGC) and r(GCGAAGC) are not so stable, although they also form mini-hairpin structures. The stability difference between these DNA and RNA mini-hairpins was examined by NMR studies and the molecular mechanics calculations, and by comparing with the stability of several sequence variants. Their stability was deduced to vary delicately depending on helical patterns formed by DNA (B form) and RNA (A form) structures.

Base Composition↗

[A case of primary alveolar hypoventilation syndrome with a good response to nocturnal low-flow oxygen inhalation and negative pressure ventilation].

A 34-year-old female was admitted on June 25, 1990, for the evaluation of alveolar hypoventilation which worsened after her second delivery. She showed impairment of both hypercapnic and hypoxic ventilatory responses, and marked desaturation due to hypopnea and apnea during sleep. Although administration of methylxanthine and medroxyprogesterone was not very effective, after treatment with low flow oxygen, there was a marked decrease in the frequency and duration of desaturation during sleep and improvement of arterial daytime blood gases, which suggested the existence of hypoxic ventilatory depression in the pathophysiology of her nocturnal desaturation. Furthermore, the use of a negative pressure ventilator for 3 hours in the daytime for 10 days resulted in marked improvement of symptoms, arterial blood gases, respiratory muscle strength, and the frequency and duration of sleep desaturation. These findings suggest that both low flow oxygen therapy during sleep, and daytime negative pressure ventilation may be beneficial in patients with primary alveolar hypoventilation and central sleep apnea syndrome.

Adult↗

Interaction of a protooncogene product, Myb with DNAs.

The DNA-binding domain of Myb consists of three imperfect tandem repeats and the third one which is essential for sequence-specific binding was established to have a helix-turn-helix-related motif. DNA sequences recognized by Myb have been reported to contain TAACPy sequence. Here we have examined the details of Myb-binding sequence. Using DNAs with a single mutation on the various sites of two specific DNAs and some fragments of the DNA-binding domain of Myb, we have found that (i) in a specific DNA which contains only one AAC sequence, each AAC nucleotide is found to be essential for the specific binding of Myb, while any other mutations cause no serious binding loss, (ii) in a specific DNA which contains two AAC sequences separately, one AAC is not so important in the binding, and (iii) for the specific binding with DNA, at least both repeats 2 and 3 of Myb are required. These findings suggest that repeat 3 containing a helix-turn-helix-related structure recognizes the core AAC sequence and repeat 2 supports this recognition by interactions with phosphate groups of DNA.

Base Sequence↗

[Surgical treatment of brain stem lesions with reference to cavernous angioma].

The surgical indications for localized brain stem lesions were evaluated retrospectively through the clinical results of 14 patients: 5 cavernous angiomas and 9 gliomas. Cavernous angiomas were located in fourth ventricle floor (2 cases), in dorsal midbrain (1 case), in right cerebellar peduncle (1 case), and in medulla oblongata (1 case). Those cases had direct surgery because of relapse of clinical symptoms and enlargement of the lesions on follow-up MR imagings. Each lesion was extirpated totally. Consequently, the majority of neurological deficits before operation improved. Therefore, radical extirpation in brain stem cavernous angioma was strongly recommended. Also, total, subtotal resection was performed for gliomas localized in brain stem: 2 low grade astrocytomas, 3 malignant astrocytomas, 3 plexus papillomas, and 1 ependymoma. Most of cases improved without new neurological deficits after surgery. In addition, MR imaging was considered to be essential to accurate diagnosis and surgical strategies for brain stem lesions.

Adolescent↗

[Blood flow dynamics and dimensions of the descending thoracic aorta in patients with intra-aortic swirling echoes: assessment by biplane transesophageal echocardiography].

To examine the blood flow dynamics in the descending thoracic aorta (DAo) where intra-aortic swirling echo contrast was observed, we analyzed the flow velocity patterns (FVP) in DAo and the DAo dimensions by biplane transesophageal echocardiography (TEE) in 9 patients with intraortic swirling echo contrast and in 25 control subjects (N). We recorded sampling volumes with pulsed Doppler echocardiograms at 3 sites: median, central, and lateral sites on longitudinal scan images and on the DAo at the level of the mitral valve. We measured systolic peak flow velocity (Vp), time from the onset of the systolic flow to Vp (acceleration time: AT), deceleration time (DT) of the systolic flow, and AT/(AT + DT) for each sampling volume in the DAo. From the M-mode echogram of DAo, we measured the maximum dimension of the aorta, which usually coincided with the mid to late systolic phase. In the normal controls, the systolic forward flow was followed by a small reversal flow in early diastole and then by a small forward flow during holodiastole. Vp was highest at the center (64 +/- 10 cm/sec), then at the median (60 +/- 11 cm/sec) and lowest in the lateral (56 +/- 9 cm/sec; p < 0.01 vs center) sites in the DAo. AT was 70 +/- 13 msec and DT 215 +/- 26 msec. This flow velocity profile in the DAo was observed in both the control and patient groups. In patients with intra-aortic swirling echoes, Vp was markedly low (33 +/- 7 cm/sec; p < 0.001 vs N) and dimension of the DAo (13 +/- 2 mm/m2 in N) was significantly enlarged (21 +/- 7 mm/m2; p < 0.001 vs N), which might be related to swirling echoes and mural thrombi at the lateral portion in the DAo. Thus, we concluded that intra-aortic swirling echoes closely related to the production of mural thrombi observed mainly at the lateral site of the significantly dilated DAo.

Aged↗

[A case report of left upper lobectomy for lung cancer performed on an aged man of 90 year old].

A 90-year-old man was admitted to our hospital because of the dyspnea on exertion and an abnormal shadow of the chest. The examinations revealed pulmonary adenocarcinoma (bronchioloalveolar cell type) of the left S3 with clinical classification of stage I. Spirometry showed severe obstructive lung dysfunction (VC 2.05 l, % VC 75.2%, FEV1.0 0.72 l, FEV1.0% 39.3%). Walking exercise in the ward and the stairs as well as instrumental physiotherapy (Triflow) partially improved his respiratory function. Left upper lobectomy and lymphnode dissection were performed. On the 3rd postoperative day the patient developed mild delirium which disappeared in a few days. He was discharged from the hospital 62 days after the operation.

Adenocarcinoma, Bronchiolo-Alveolar↗

[Usefulness of segmental Lp-TAE using lipiodol mixed with anticancer agent for inoperable hepatocellular carcinoma].

To determine the effect of appraising subsegmental or segmental transarterial embolization with Lipiodol mixed with anticancer drugs followed by gelatin particles (Segmental Lp-TAE) on inoperable hepatocellular carcinoma, we examined CT patterns and therapeutic results in 57 patients after Segmental Lp-TAE. Fifty-six tumors including 47 tumors less than 5 cm in size were the nodular type and 1 tumor was the massive type. The mean tumor size was 3.6 cm and the mean amount of Lipiodol was 4.4 ml. Portal veins in the embolized segment were highly visualized by injected Lipiodol on plain film immediately after Segmental Lp-TAE. On the follow-up CT, the size of the tumor with dense Lipiodol accumulation were reduced in all cases, and atrophy of the embolized segment was recognized. Forty-four of the 57 patients are alive, with the longest surviving patient still alive at 4 years and 5 months. Seventeen patients have survived for more than 2 years (direct crude survival rate: 65.0%), with the cumulative survival rates 93.2% at 1 year, 71.6% at 2 years. No recurrence was recognized in 33 of the 41 patients (80.0%) that were followed up for more than 1 year after Segmental Lp-TAE is a useful therapeutic method for hepatocellular carcinoma.

Aged↗

[A case of chronic toluene poisoning with myopathic changes].

We reported a 27-year-old man, who had inhaled toluene vapor for 11 years and developed both polyneuropathy and myopathy. He gradually developed progressive muscular weakness in the limbs 2 months after the last inhalation and became nonambulant. Neurological examination revealed distal dominant muscular weakness and hypoactive deep tendon reflexes, especially in the legs. The cranial nerves were intact and neither sensory disturbances nor cerebellar signs were observed. Laboratory studies demonstrated mildly elevated serum CK value, but serum electrolytes and urinalysis were normal. Electromyogram showed a neurogenic pattern in the limbs and also a myogenic in the gastrocnemius muscle. Motor nerve conduction velocities were delayed in the limbs. The sural nerve biopsy specimens showed demyelination, myelin avoids, and axonal swelling compatible with toxic neuropathy. The muscle biopsy of the gastrocnemius revealed necrotic muscle fibers, vacuolated muscle fibers, phagocytosis, a disordered intermyofibrillary network, and small group atrophy on light microscopy. On electron microscopy, two outstanding findings were observed; the first, dilatation and proliferation of the membrane system, and the second, appearance of irregular membrano lamellar structures and vacuoles associated with abnormal membrane system. These histological findings suggest that toluene may affect directly the membrane system of muscle fibers and consequently induce rhabdomyolysis.

Adult↗

[A case of leiomyoma of the chest wall].

A case report of a leiomyoma of the chest wall is presented. So far as we examined, this is the first case of the leiomyoma of the chest wall in Japan. A 40-year-old woman was admitted to our hospital because of an abnormal shadow in the right upper lung area in a chest X-ray film. The thoracic CT and MRI demonstrated a tumor of the chest wall projecting into the thoracic cavity. The tumor was excised. Histological examination indicated that the tumor was a benign leiomyoma. This tumor seems to originate from the wall of the small vessels histologically. The patient's postoperative course is uneventful.

Adult↗

[Studies on a serum factor inhibiting lactate dehydrogenase (LDH) activity in a patient's serum].

We found extremely low activity of serum lactate dehydrogenase (LDH, EC. 1.1.1.27) in a 70-year-old female patient. The decrease of LDH activity was observed when the normal serum was incubated with the patient's serum. Inhibition rate of LDH activity by the patient's serum was higher at 4 degrees C than at 37 degrees C. The patient's serum inhibited both subunits of LDH, and inhibited more strongly the M-subunit than the H-subunit LDH isoenzymes. IgG (lambda type) in the patient's serum was found to be responsible for the inhibition of LDH activity. The mechanism why IgG inhibiting LDH activity developed in the patient's serum remain undetermined.

Aged↗

[Prophylactic use of antibiotics for fever following fiberoptic bronchoscopy and bronchography].

To evaluate the effect of bacampicillin hydrochloride on fever following fiberoptic bronchoscopy and bronchography, we conducted multi-institutional randomized study. In bronchographic examinations, the rise of body temperatures in the bacampicillin group (0.82 +/- 0.13 degrees C: mean +/- SE) was significantly smaller than that in the control group (1.39 +/- 0.25 degrees C) on the second day of examination. Bacterial infection may contribute to the rise of temperature on the day following bronchography, but no pneumonia or sepsis was observed. There was no differences in the rise of body temperature on the first, third or fourth day. In fiberoptic bronchoscopic examinations, there was no difference between the two groups. We conclude that there is no clinical indication of the value of prophylactic use of antibiotics in either fiberoptic bronchoscopy or bronchography.

Adult↗

[Renal cell carcinoma in a renal cyst--observation of changes during the year: report of a case].

We report a case of renal cell carcinoma within a renal cyst. A 45-year-old man visited our hospital with the chief complaint of left back pain. Ultrasonography was examined by a physician, and it revealed a right renal cyst by chance. Computed tomography demonstrated a thick wall in the cyst which showed enhancement of density with contrast medium. The physician followed the cystic lesion periodically, by ultrasonography and computed tomography. The cyst on volume did not change, but the thick wall had a tendency to develop to inner space. The patient was referred to our department. Angiography was performed, and it showed neovascularity and tumor staining. We diagnosed the renal tumor in a renal cyst. Transabdominal right radical nephrectomy was performed on 18 June, 1991. The resected specimen involved a mall tumor (2.5 x 2.0 cm) in the cyst. Histological examination of the tumor was renal cell carcinoma which was well capsulated by connective tissue without invasion to normal parenchyma and perirenal fat. We speculated that the renal cell carcinoma originated from the cyst wall and it developed to inner cystic space. The natural history of the renal cell carcinoma in a renal cyst is not clear. Our case shows a type of its history. We reviewed and discussed the types and diagnosis of the renal cell carcinoma in a renal cyst.

Carcinoma, Renal Cell↗

[A case of C5 deficiency with polyarthritis].

A 27-year-old female with polyarthritis was found to lack serum complement activity. Her serum CH50 was less than 1.9 U/ml. C5 protein in her serum was less than 2 mg/dl and its activity was not detected. The serum level of the other proteins of complement system examined were within the normal range. At 17 years old, she was diagnosed as rheumatic fever and was admitted to our hospital. She was treated with aminobenzylpenicillin and predonisolone for two months, and she was discharged from our hospital without any abnormalities. But she had no other episode of repeated infections. Family studies of this patient revealed that an elder sister of this patient was also homozygous deficiency of C5 and her parents were considered to be heterozygous deficiency of C5. From these results, the patient was considered to be inherited deficiency of C5.

Adult↗

[Clinical experience of reoperation for anastomotic stricture following proximal gastrectomy for esophageal varices].

A few cases were reported in which second reconstructive operation on gastrointestinal tract for reflux esophagitis following the proximal gastrectomy was performed. But no previous report of the removal of anastomotic region for treating anastomotic stricture due to reflux esophagitis has appeared. Also, there are no reports on second operations to treat anastomotic strictures following proximal gastrectomy for esophageal varices. We report a case in which we obtained favorable results in treating an anastomotic stricture due to reflux esophagitis, which developed following a proximal gastrectomy for esophageal varices, by performing removal of the anastomotic region and resection of the remaining stomach with reconstruction by the Roux-en Y method.

Aged↗