Biomedical subjects

M Nishimura

Publications and source records attributed to M Nishimura.

At least 55 records · Page 3Linked to original sources

PubMed1992

Beta-3 adrenergic agonist, BRL-26830A, and alpha/beta blocker, arotinolol, markedly increase regional blood flow in the brown adipose tissue in anesthetized rats.

Regional vascular effects of some adrenergic agents, focussing on brown adipose tissue (BAT), were investigated using tracer microspheres with a reference sample method in the anesthetized rat. Intravenous injections of 0.5 mg/kg BRL-26830A, a beta 3-adrenergic agonist, increased heart rate, but changes in blood pressure and cardiac output were not significant. The drug decreased blood flow in the brain, the spleen and the kidneys, but markedly increased it in BAT. At 2 mg/kg, arotinolol, an alpha/beta-adrenergic blocker, decreased blood pressure by 20 mmHg and increased cardiac output by 95 ml/min/kg. It slightly but significantly decreased blood flow in the liver and the spleen, but markedly increased the flow in BAT. Acebutolol, a beta 1-adrenergic blocker, decreased blood flow in the liver, the spleen, the pancreas, the kidneys, the adrenals, the skeletal muscle and the skin. Bunazosin, an alpha 1-adrenergic blocker, decreased it in all organs and tissue expect the brain and BAT. The pattern of redistribution of blood flow by arotinolol was very similar to that caused by BRL-26830A. Acebutolol and bunazosin rather decreased the blood flow in the BAT. These results indicate that stimulation of beta 3-adrenergic receptors, in BAT results in vasodilation, and that arotinolol may bind to those beta 3-adrenergic receptors.

Adipose Tissue, Brown↗

PubMed1992

Compensatory changes in silver-stainability of nucleolar organizer regions in mice.

Silver-stainability of nucleolar organizer regions (NORs) that contain genes for ribosomal RNA (rDNA) was investigated using two mouse strains, BALB/cCrSlc and MOA, and their hybrid progeny. The patterns of segregation of the rDNA clusters were analyzed in terms of chromosomal C-banding and by use of a polymorphic probe for the variable region in backcrossed N2 and N3 individuals. The results indicate that the intensity of Ag-NOR staining is stably inherited in most of the rDNA clusters, irrespective of different genetic backgrounds. In some clusters, such as those on chromosome 12 of BALB/cCrSlc, a modulation of the intensity is observed. This modulation seems to be due to compensatory activation via a change in the number of actively transcribed genes. The change from silver-negative to silver-positive staining of the NOR of chromosome 12 of BALB/cCrSlc was correlated with demethylation of the genes.

Animals↗

PubMed1992

Hypoplastic left heart syndrome associated with congenital right-sided diaphragmatic hernia and omphalocele.

Congenital diaphragmatic hernia (CDH) is associated with a variety of cardiac anomalies. However, its association with hypoplastic left heart syndrome (HLHS) is rare. We treated a female newborn with CDH, HLHS, and omphalocele. The operation for omphalocele and the diaphragmatic defect was successful, although the patient died of cardiac failure after Norwood's operation for HLHS. To our knowledge, this is the first reported case with a combination of these three major anomalies: CDH, HLHS, and omphalocele.

Female↗

PubMed1992

Capnometry during high-frequency oscillatory ventilation.

We used capnometry during high-frequency oscillatory ventilation (HFOV), and compared CO2 measurements at the distal and proximal ends of an endotracheal tube with arterial CO2 values. Ten white rabbits (mean weight, 2.00 +/- 0.2 [SD] kg) underwent tracheostomy under anesthesia with pentobarbital. The trachea was intubated with an endotracheal tube with a second lumen for sampling respiratory gas at the distal tip. Capnometry was performed through the lumen (CO2d) and the proximal end of the endotracheal tube (CO2p). The internal carotid artery was cannulated to sample blood for measuring arterial blood gases. The differences between CO2d, CO2p, and PaCO2 were measured. Only the relation between CO2d and PaCO2 was good (r = 0.915). We concluded that capnometry can be used during HFOV to estimate PaCO2 provided that respiratory gas is sampled from the distal tip of the endotracheal tube.

Animals↗

PubMed1992

Paradoxical bradycardia during exercise and hypoxic exposure. The possible direct effect of hypoxia on sinoatrial node activity in humans.

We describe a patient with pulmonary emphysema who developed paradoxical cardiodeceleration not only during incremental exercise associated with hypoxemia but also during progressive hypoxic challenge. Since coronary angiogram revealed no abnormality, this unique phenomenon seemed to be due to the direct effect of hypoxia on the sinus node activity.

Bradycardia↗

PubMed1992

Colliding malignant lymphoma and adenocarcinoma of the stomach: case report.

We report a case of malignant lymphoma presenting as the superior vena cava syndrome. This case is very interesting since both adenocarcinoma mucocellulare scirrhosum, Borrman type IV, and lymphoma were present in the stomach, forming colliding neoplasms. Rather than systemically disseminated, the lymphoma cells were localized in the stomach, the intestine, a few perigastric lymph nodes and in a mediastinal mass, which may have constituted a neoplastic thymus invaded by lymphoma cells from the stomach. The unique occurrence of the histological combination as gastric colliding neoplasms is discussed.

Adenocarcinoma↗

PubMed1992

Platelet-derived growth factor gene expression in the kidney of malignant hypertension.

To examine the pathogenetic role of platelet-derived growth factor (PDGF) in hypertensive kidney damage, we studied the gene expression of PDGF A-chain and B-chain in an animal model of malignant hypertension. Experimental malignant hypertension induced by unilateral nephrectomy combined with deoxycorticosterone and salt loading in the spontaneously hypertensive rat resulted in severely elevated blood pressure and renal histological damage, characterized by necrotizing vasculitis. Using reverse transcription-polymerase chain reaction analysis followed by Southern blot analysis, we observed that PDGF B-chain gene expression was increased in the kidney of experimental malignant hypertension and was correlated with the severity of glomerular damage, while PDGF A-chain gene expression was unaffected. Antihypertensive treatment with manidipine reduced glomerular damage and a decreased gene expression of PDGF B-chain. These results suggest that PDGF B-chain may have a role in mediating hypertensive kidney damage.

Animals↗

PubMed1992

[Involvement of cholinergic mechanism in respiratory chemosensitivity to CO2 in humans].

In an attempt to elucidate the role of cholinergic mechanism in respiratory chemosensitivity to CO2 in humans, we examined 17 healthy male volunteers for ventilatory responses to hyperoxic progressive hypercapnia and isocapnic progressive hypoxia on three separate days in a randomized, double-blind fashion. Pirenzepine, a M1 muscarinic antagonist which does not cross the blood-brain barrier, biperiden, another M1 muscarinic antagonist which is expected to penetrate into the central nervous system, or placebo was intravenously preinjected before the measurement of ventilatory responses. There were no significant differences in the mean magnitude of ventilatory responses among the three experimental days. However, despite the poor correlation between the magnitude of ventilatory response to hypercapnia in the placebo and pirenzepine studies, there was a significant correlation between them when the value in the pirenzepine study was expressed as % of control, value i.e., subjects with greater hypercapnic ventilatory response in the placebo study showed greater declines with biperiden. Since these relations were seen only for the ventilatory response to hypercapnia with biperiden, we suggest that a cholinergic mechanism, particularly the M1 muscarinic receptor, may be involved in chemoreception to CO2 in the central nervous system and constitute the neurochemical background for the interindividual variation in hypercapnic ventilatory response in humans.

Adolescent↗

PubMed1992

[Phrenic nerve palsy after open heart surgery--problems in post-operative respiratory management].

We clarified the problems in respiratory management in patients with phrenic nerve palsy (PNP) after open heart surgery. From December 1988 to March 1991, 248 adult patients underwent open heart surgery with topical myocardial cooling. In these patients PNP was diagnosed in 17 patients (6.9%). Age of these patients at operation ranged from 25 to 76 years with a mean age of 57 years. 9 patients were valvular heart disease (7 were reoperation), 7 were coronary artery disease, and one patient was aortic aneurysm. PNP was diagnosed by chest roentgenogram or percutaneous phrenic nerve stimulation test (PNST). Frequency of long-term intubation (> 14 days) was higher in complete PNP patients than incomplete PNP patients. 2 patients, who were observed effort dyspnea at the time of respiratory weaning, were extubated followed by respiratory and circulatory deterioration, and were reintubated. PNP were confirmed after reintubation by PNST. These patients died of pneumonia. Another 2 patients were observed effort dyspnea during respiratory weaning, and were doubted of PNP. PNP were confirmed by PNST before extubation. After hemodynamic stabilization and respiratory physiotherapy, these patients were extubated without any trouble. One patient, who required repeated intubation, was diagnosed PNP by PNST. This patient was extubated after confirmation of improvement of PNP by follow-up PNST. The incidence of PNP was higher in patients with previous open heart surgery than without previous operation. We supposed that the dissection around the heart might be one of major cause of postoperative PNP. So, in recent 4 cases of mitral reoperation, we attempted to reach mitral valve through atrial septum with minimum dissection.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1992

[Human lung cancer cell lines in our laboratory: establishment of three large cell carcinoma cell lines and their biological characterization].

Three large cell carcinoma cell lines were established from tumors of lung cancer patients. The cell lines were named NUTLC-2, NUTLC-4 and NUTLC-5 and they were found to have the following biological characterization. 1) By chromosomal analysis, the tumor cells of two of the cell lines (NUTLC-2 and NUTLC-5) were human-origin cells. Numbers of chromosomes of these cells ranged from 52 to 59 in NUTLC-2 and from 68 to 75 in NUTLC-5, with the modal numbers of 56 and 71, respectively. 2) Primary tumor resected from the patient with lung cancer was heterotransplanted into the subcutis of a nude mouse. NUTLC-4 cell line was established in vitro from the tumor in nude mouse and the tumor cells were found to be mouse-origin cells by chromosomal analysis. Human DNA was not detected by Alu analysis. 3) The tumor cells of three cell lines could be heterotransplanted subcutaneously into nude mice. However, no natural distant metastasis in nude mouse was observed. 4) Drug sensitivity to NUTLC-2, NUTLC-4 and NUTLC-5 tumor cells differed individually according to MTT colorimetric assay, and characteristic drug sensitivity was not noted in histological types of lung cancer.

Aged↗

PubMed1992

[Hypergastrinemia and type A gastritis in Basedow's disease].

Hypergastrinemia is a very important clinical condition for the reason that a growing body of evidence obtained from animal and human experiments has revealed gastric carcinoids induced by hypergastrinemia. We investigated 35 patients with Basedow's disease (BD) to elucidate the mechanism of hypergastrinemia associated with BD as well as the relationship between type A gastritis and BD. Fasting serum gastrin levels in BD (296.1 +/- 251.4 pg/ml; mean +/- S.D.) were significantly (p less than 0.001) higher than those in age-matched 27 healthy subjects (106.1 +/- 69.2), and in the BD group, significant positive correlation was detected between fasting serum gastrin levels and thyroid hormones (i.e. T3 and free T4). In the hyperchlorhydria group in BD with hypergastrinemia, the levels of fasting serum gastrin were normalized after euthyroidism was attained due to antithyroidal drugs. On the other hand, in the achlorhydria group in BD significant hypergastrinemia was persisted in spite of normalization of thyroid function. Twenty % of the BD patients had histologically proved type A gastritis with achlorhydria, and all patients with type A gastritis were older than 60 years old. Endoscopic examination revealed that one patient with type A gastritis had an early gastric cancer. However, no gastric carcinoids were demonstrated in this study. In conclusion, the results described as above suggested, 1) hypergastrinemia observed in patients with BD may be induced by gastrin hypersecretion due to hyperthyroidism as well as type A gastritis, 2) BD patients with type A gastritis were recommended to undertake regular endoscopic examination for detecting gastric cancers as well as gastric carcinoids.

Adult↗

PubMed1992

[Relation between dyspnea and personality in patients with pulmonary emphysema and healthy subjects].

To determine whether personality is related to dyspnea sensation, 19 healthy males and 17 male patients with pulmonary emphysema were tested for modified visual analog scale (VAS) during hypoxic and hypercapnic interventions. Personality was tested by both Yatabe-Guillford test and manifest anxiety scale. VAS score correlated positively with anxiety score during hypercapnia and inspiratory resistive loading under hypercapnia in healthy subjects. In patients, anxiety score correlated positively with VAS scores during hypoxia, hypercapnia, and resistive loading under hypercapnia. Scores for nervousness and cyclic tendency correlated with VAS scores during hypoxia and hypercapnia in patients. These results indicate close relation between anxiety and dyspnea in healthy as well as emphysematous subjects. In emphysema, nervousness and cyclic tendency are the additional determinants for dyspnea.

Depression↗

PubMed1992

[Relationship between clinical symptoms and nocturnal oxygen desaturation in sleep apnea syndrome and chronic lung disease].

Nocturnal oxygen desaturation (NOD) is commonly seen not only in sleep apnea syndrome (SAS) but also in chronic lung disease (CLD) including chronic obstructive lung disease even without sleep apnea. However, the relationship of NOD to clinical symptoms such as morning headache, sleep deprivation due to breathlessness, and daytime sleepiness is not known. In this study, we examined by polysomnography the relationship between several NOD indexes, parameters of apnea, and subjective symptoms in 25 patients with SAS and 22 patients with CLD. In addition, the relation between daytime arterial blood gas data and NOD indexes, parameters of apnea, was examined. In the SAS group, there were no differences in any parameters of NOD and apnea between patients with subjective symptoms and those without symptoms. However, in the CLD group, symptomatic patients had significantly lower lowest SaO2, higher mean SaO2, and longer total desaturation time. In both groups, daytime PaCO2 had a significant correlation with several NOD parameters such as mean SaO2, lowest SaO2, and total desaturation time. In the SAS group, daytime PaCO2 was also correlated with the parameters of apnea. On the other hand, daytime PaO2 was significantly correlated with mean SaO2 only in the CLD group. From these data, we conclude that in patients with SAS, daytime PaCO2 is a variable that is related to the degree of NOD, and that in patients with CLD, subjective symptoms and daytime PaO2 in addition to daytime PaCO2 are associated with NOD.

Blood Pressure↗

PubMed1992

[Effect of hypoxia on the sensation of dyspnea during hypercapnic ventilatory response in normal subjects].

We examined, in 32 normal adults, the effect of hypoxia on the sensation of dyspnea during hypercapnic ventilatory response (HCVR). The tests were conducted under two different levels of inspiratory O2 content, either hyperoxia (PETO2 greater than 150 Torr) or hypoxia (PETO2 50-55 Torr), with simultaneous assessment of dyspnea sensation by visual analogue scaling (VAS). The sensation was evaluated either in relation to VE standardized by predicted MVV (the slope of VAS-VE regression line or VAS at VE 40%) or in relation to PETCO2 (the slope of VAS-PETCO2 line or VAS at PETCO2 55 Torr). Concomitant hypoxia significantly enhanced both the mean value of delta VE/delta PETCO2 and that of delta P0.1/delta PETCO2. The sensation of dyspnea did not differ between the two conditions when it was evaluated in relation to ventilation, whereas it was markedly greater during hypoxic HCVR when it was evaluated in relation to PETCO2. The hypoxic augmentation of the sensation, compared at PETCO2 55 Torr, could be explained by increase of the motor output from the respiratory center, since it was positively correlated with the relative change of VE, VTTI, and delta P0.1/delta PETCO2 (r = 0.70, p less than 0.0001; r = 0.63, p less than 0.0001; r = 0.40, p less than 0.05, respectively). From these findings, we conclude that hypoxia does not have a direct dyspnogenic effect, at least in normal subjects.

Adult↗

PubMed1992

[Male bladder leiomyoma: a case report].

A case of leiomyoma of the urinary bladder in a 40-year-old man is reported. Enucleation of the tumor was performed, because transurethral resection-biopsy revealed a bladder leiomyoma. Ninety nine cases of a bladder leiomyoma have been reported in Japan, but male cases are rare.

Adult↗

PubMed1992

[A case of renal squamous cell carcinoma associated with giant hydronephrosis and ureteral stone: efficacy of imaging modality].

A rare case of squamous cell carcinoma of the right kidney associated with giant hydronephrosis and right ureteral stone was reported. A 60-year-old woman was referred to our department with a complaint of ileocecal dull pain. A plain computerized tomogram (CT) revealed giant hydronephrosis, and a kidney-ureter-bladder X-ray revealed a right lower ureteral stone. A right percutaneous nephrostomy was done and antegrade pyelography revealed giant hydronephrosis and a ureteral stone, but showed no intrapelvic filling defect. Under the diagnosis of right ureteral stone with hydronephrosis, right ureterolithotomy was done. However, since the inflammation did not subside after ureterolithotomy, right nephrectomy was done. The surgically removed right kidney did not show any evident tumor mass, a histological study revealed squamous cell carcinoma involving renal parenchyma. The patient received no adjuvant therapy and died 3 months after nephrectomy with sudden appearance of bone, liver and pulmonary metastases. The preoperative efficacy of imaging modalities for renal squamous cell carcinoma was discussed herein.

Carcinoma, Squamous Cell↗

PubMed1992

Local cerebral blood flow and CO2 reactivity during prostaglandin E1-induced hypotension in patients undergoing cerebral aneurysm surgery.

The effects of prostaglandin E1 (PGE1) on local cerebral blood flow and CO2 reactivity were studied in 30 patients undergoing cerebral aneurysm surgery in eight of whom the aneurysm had not ruptured and was an incidental finding. The aneurysms were clipped at various intervals depending upon clinical conditions. Blood flow on the open brain surface was measured with a thermal gradient blood flow-meter. Hypotension was initially induced with 0.1 microgram kg-1 min-1 of PGE1 and subsequently adjusted to maintain the mean arterial blood pressure at about 70 mmHg. Local cerebral blood flow and CO2 reactivity were studied during and after PGE1 administration. Both were preserved, but CO2 reactivity values were lower in patients in whom the aneurysm had ruptured than in those in whom it had not ruptured. PGE1 may be an appropriate drug with which to induce hypotension during cerebral aneurysm surgery because cerebral blood flow and CO2 reactivity is preserved.

Adult↗

PubMed1992

[A clinical study of transfer of cefminox and piperacillin into pulmonary tissue].

Serum concentrations of cefminox (CMNX) and piperacillin (PIPC) and their transfer into pulmonary tissue during surgery were serially studied following 1-hour intravenous instillation of 1 g of CMNX or PIPC immediately before thoracotomy, and the following results were obtained. Maximum serum concentrations of CMNX and PIPC were observed 1 hour after the commencement of administration, and their levels gradually decreased thereafter. The mean peak level of CMNX was 72.21 micrograms/ml, and T 1/2 was 1.62 hours. The mean peak level of PIPC was 43.26 micrograms/ml, and T 1/2 was 1.54 hours. In the pulmonary tissue, mean concentrations of CMNX in the normal pulmonary (alveolar) tissue were 28.80, 26.50 and 17.80 micrograms/g at 2.5, 3 and 4 hours, respectively, after the commencement of administration, and the corresponding levels for bronchiolar tissue were 19.6, 18.40 and 20.53 micrograms/g, respectively. The mean concentrations of PIPC in the normal pulmonary (alveolar) tissue were 18.97, 7.34 and 5.0 micrograms/g at 2, 3 and 4 hours, respectively, after the commencement of administration, and the corresponding levels for bronchiolar tissue were 7.2, 9.20 and less than 0.2 micrograms/g, respectively. PIPC also showed favorable transfer into the hilar lymph node tissue and obstructive pneumonitic lesions. The transfer of both drugs into pulmonary tissue suggests that both drugs are useful for the treatment of respiratory infectious diseases and the prevention of postoperative infections.

Adult↗