Biomedical subjects

S Yoshimoto

Publications and source records attributed to S Yoshimoto.

At least 37 records · Page 2Linked to original sources

PubMed1998

Ligation of medically refracted patent ductus arteriosus (PDA) in an extremely low body weight premature infant.

Medically refracted patent ductus arteriosus (PDA) in an extremely low birth weight (ELBW) preterm (gestation 24 weeks 2 days) infant was successfully ligated under general anesthesia in the neonatal intensive care unit (NICU). Pharmacological agents are more effective to close PDA in preterm infants than in full-term infants, although within 48 h three doses of indomethacin were not sufficient to close PDA in this case. At the age of 69 h the infant developed severe symptoms including bradycardia, systemic hypotension, pulmonary hypertension, diastolic steal (reverse distal aorta flow velocity), and anuria. A PDA ligation was thus performed surgically at 72 h of age. General anesthesia and surgical stress were tolerated by this 531 g infant. Postoperatively all symptoms improved dramatically and the general conditions were stable. On the 38th day the endotracheal tube was extubated and on the 50th day nasogastric milk feeding was started. The oxygen supply was weaned on the 78th day. Growth and development until 6 months were within the normal range of very low birth weight infants. A surgical ligation as early as possible in medically refracted PDA in an ELBW infant is thus considered to be a safe and effective treatment. It prevents the development of further complications of cardiopulmonary vascular problems. Color Doppler echocardiography can reliably measure the PDA size, flow velocity, and hemodynamic changes of persistent PDA, even in tiny infants.

Ductus Arteriosus, Patent↗

PubMed1998

External-internal oblique reverse blood supply musculocutaneous flap for chest wall reconstruction.

A defect resulting from resection of advanced breast tumor can be quite large, posing a difficult reconstructive challenge. A significant number of such patients are found to have local recurrences after receiving beam radiation therapy and chemotherapy. The external oblique musculocutaneous flap is now considered a reliable option, with segmental blood supply from the posterior intercostal arteries. We report a 57-year-old man with local recurrence of breast tumor after external beam therapy. We faced a difficult challenge in performing reconstruction because of (1) several previous operations that used most of the usual options and (2) the absence of recipient vessels for microsurgery. We performed an external-internal oblique musculocutaneous flap with a reverse blood supply from the lateral branches of the inferior epigastric artery. Our use of a reverse-flow external-internal oblique flap supports the concept of rotating the muscles as a unit to encourage viability of the denervated and relatively devascularized component.

Arteries↗

PubMed1998

Parvovirus B19-associated transient pure red cell aplasia with lymphadenopathy: a case report.

There have been few reports on lymph node swelling in human parvovirus (HPV) B19 infection. A report of a 42-year-old female, who developed HPV B19-associated transient red cell aplasia with lymphadenopathy, is presented. The lymph node swelling began with the appearance of atypical lymphocytes in the peripheral blood and it disappeared as the patient recovered from the aplasia. Microscopically, the patient's bone marrow showed characteristic giant proerythroblasts with no maturation of the erythroid series. An excised inguinal lymph node showed florid, reactive follicular hyperplasia with paracortex expansion, and neutrophil infiltration and hemophagocytosis in the medullary sinus. These findings were compatible with the histology of a viral infection. A polymerase chain reaction study revealed HPV B19 in her serum and lymph node, but an immunohistochemical study failed to demonstrate HPV B19 capsid antigen in the lymph node or bone marrow. Although the present case suggests that reactive lymphadenopathy is associated with HPV B19 infection, the mechanism of the lymph node swelling still remains to be elucidated.

Adult↗

PubMed1997

Virus elimination and histologic improvement in patients with chronic hepatitis C treated with interferon alpha.

We evaluated the elimination of hepatitis C virus (HCV) by means of interferon alpha (IFN-alpha) by investigating both positive- and negative-stranded RNA forms in the peripheral blood mononuclear cells and liver tissue. We also assessed the long-term histologic improvement accompanying viral clearance. We studied 20 persons with HCV whose serum aminotransferase levels remained normal for more than 1.5 years after IFN-alpha treatment withdrawal. The presence of HCV RNA in their peripheral blood and of both positive and negative strands in the peripheral blood mononuclear cells and liver tissue was investigated using the reverse transcription polymerase chain reaction method. We examined the histologic findings using the European classification and the histology activity index scoring system. In 16 of 20 patients, both strands disappeared from the possible reservoirs. The histologic findings indicated reduced activity, and histology activity index scores (1, 2, 3, and total) also showed significant improvement. We confirmed that IFN-alpha therapy can induce the elimination of HCV RNA from the conceivable HCV reservoirs and effect histologic improvement. Therapy with IFN-alpha is effective for treating chronic hepatitis C.

Adult↗

PubMed1997

Daunorubicin-induced smooth muscle contraction: involvement of Ca2+ entry mechanism.

The mechanisms of the smooth muscle contractile action of daunorubicin were investigated using guinea-pig aortae, and the involvement of the Ca2+ entry mechanism was compared among different smooth-muscle preparations. In the aorta, daunorubicin showed a concentration-dependent contractile action at concentrations of 10-200 microM. The contractile response to daunorubicin was completely dependent on extracellular Ca2+, but only slightly sensitive to verapamil or nifedipine. Trifluoperazine abolished the contraction by daunorubicin, but no significant effect was noted with amiloride, phentolamine, indomethacin or staurosporine. The order of potency (sensitivity) for daunorubicin-induced smooth muscle contraction was oesophagus = gall bladder = iliac artery > bronchus = aorta, while that of maximum reactivity was iliac artery = aorta > bronchus = oesophagus = gall bladder. In the portal vein, daunorubicin showed no contractile action. Although the smooth muscle contraction induced by daunorubicin was strongly dependent on extracellular Ca2+ in the aorta, iliac artery, bronchus, oesophagus and gall bladder, its sensitivity to verapamil varied among the different smooth muscle preparations, with the sensitivity being iliac artery = gall bladder > bronchus = oesophagus > aorta. These results suggest that daunorubicin has contractile action on various kinds of smooth muscle, mainly via the transplasmalemmal Ca2+ entry mechanism, but the degree of involvement of the voltage-dependent Ca2+ channel differs among the different smooth muscle preparations.

Animals↗

PubMed1997

[Potentiating effect of ethanol on alpha 1 adrenergic receptor mediated contraction of thoracic aorta from guinea pig].

Using aortic strips isolated from guinea pigs, effects of ethanol on vascular smooth muscle tonus were studied. 50mM of ethanol significantly potentiated the contractions induced by norepinephrine and phenylephrine, but did not influence those induced by KCl and clonidine. Furthermore, ethanol significantly augmented the contraction induced by phenylephrine in the presence of verapamil, and did not have any effects on the contractions induced by A23187, Ba2+, PDBu and BAY K 8644. These results indicate that ethanol potentiates the alpha 1 adrenergic receptor-mediated contraction, depending on the extracellular calcium influx via the receptor-operated calcium channel.

Adrenergic alpha-Agonists↗

PubMed1996

[Prognostic factors of lateral wall oropharyngeal squamous cell carcinoma--retrospective study of 79 patients].

We reviewed 79 patients with squamous cell carcinoma of the lateral wall of the oropharynx who received treatment at the Cancer Institute Hospital. Tokyo, between 1971 and 1990. There were 67 men and 12 women, aged 31 to 81 years (average 59.2 years). The tumors could be staged by TNM classification (UICC 1987) as follows: Stage 10 Stage II 12, Stage III 27, Stage IV 40. It must be noted that more than 50% of the tumors were classified as stage IV. As the initial treatment, 50 patients underwent radical radiotherapy, and the remaining 29 were treated mainly by surgery after pre-operative radiation. Some patients underwent adjuvant chemotherapy, but the role of chemotherapy was not considered in this study. The purpose of the present study was to determine the prognostic factors and to determine the survival rate after each treatment modality. The results were as follows: i) Patients with either T4, over N2b or a stage IV tumor had a significantly poor prognosis. ii) Cox multivariate analysis revealed that age, local extension (base of tongue, anterior pillar, soft palate and mid-line), pathological findings (poorly, moderately or well differentiated), tumor type (exophytic or endophytic) were not useful prognostic factors. iii) Radiosensitivity was not reflected in the survival rate judging from the high recurrence rate (44%) after radical radiotherapy. On the other hand, local recurrence after radical resection was seen in 18% of the patients. iv) Analysis of the data supported the recommendation of surgery after preoperative radiation as the treatment for stage III patients. It seems difficult to find the best treatment modality for stage IV patients in order to improve the survival rate, and this is an issue that still remains to be resolved. v) From the study of the surgical specimens, we are unable to demonstrate a significant survival advantage of the patients with a high grade radiation effect, or patients with no vessel involvement.

Adult↗

PubMed1995

Is caloric restriction effective in preventing diabetes mellitus in the Otsuka Long Evans Tokushima fatty rat, a model of spontaneous non-insulin-dependent diabetes mellitus?

Studies were made on the effectiveness of caloric restriction in preventing the development of diabetes mellitus in a model rat (Otsuka-Long-Evans-Tokushima Fatty; OLETF) with non-insulin-dependent diabetes mellitus (NIDDM). Groups of 8 male OLETF rats aged 5 weeks were supplied with rat chow ad libitum (100% group) and 85% and 70% of the amount of food consumed by the 100% group (85% and 70% groups, respectively). The average weights of the 100%, 85% and 70% groups were 617, 536 and 450 g at 19 weeks of age and their abdominal fat deposits were 50, 38 and 21 g, respectively, at 22 weeks of age when they were killed. At 20 weeks of age, the cumulative incidences of diabetes mellitus in the 100%, 85% and 70% groups were 67%, 13% and zero, respectively. The plasma immunoreactive insulin (IRI) levels 60 and 120 min after oral glucose administration were significantly lower in the 70% group than in the other groups. In vivo insulin-stimulated glucose uptake measured by a euglycemic clamp technique, was significantly higher in the 70% group than in the 100% group. There was no significant difference in the glucose transporter 4 protein levels of skeletal muscles in the three groups, but the highest ratio of glucose transporter 4 in the plasma membrane to that in intracellular membranes was observed in the 70% group. Morphological studies on the pancreas of rats in the 100% group showed enlarged multilobulated fibrotic islets, whereas sections of islets of rats in the other groups appeared normal, though slightly enlarged. These results demonstrate that caloric restriction is effective in preventing NIDDM in diabetes-prone rats, probably due to increased insulin sensitivity.

Aging↗

PubMed1995

Treatment of nevus Ota by liquid nitrogen cryotherapy.

Nevus Ota is a disfiguring facial dermal melanosis that is observed rarely in Caucasians but is common in Asians. Until recently, carbon dioxide snow cryotherapy had been used most frequently to treat this disorder, but the results were not always satisfactory and often left scarring after treatment. During the past 15 years, we have treated a total of 600 cases of dermal pigmentary facial disfiguration using CRYO-MINI, a liquid nitrogen cryogenic instrument with a removable disk-shaped copper tip. We have found this method to be simple and extremely effective in the treatment of nevus Ota and senile lentigines, and it is also useful for treatment of delayed nevus spilus and blue nevus. This report presents our techniques and experiences as well as the results achieved with four patients who have a deeply situated type of nevus Ota. Associated problems to be considered in future treatment are discussed also.

Adult↗

PubMed1995

[Axonal Guillain-Barré syndrome associated with anti-GalNAc-GD1a antibody subsequent to Campylobacter jejuni (PEN 43) enteritis].

We reported a 16-year-old boy who had Guillain-Barré syndrome (GBS) after suffering diarrhea. Campylobacter jejuni was isolated from his stool, and the serotype belonged to PEN 43. Neurologic examination revealed distal-dominant muscle weakness atrophy, and mild sensory disturbance. Motor and sensory nerve conduction velocities were normal, but compound muscle action potentials were markedly reduced. Serum from the patient had high titers of anti-FalNAc-GD1a antibodies. He had HLA-A24, B51, DRB1*04 and DRB1*09. His elder sister showed diarrhea and serum anti-C. jejuni antibody, but did not showed GBS and serum anti-ganglioside antibody. Her HLA types were A24, B51, DRB1*09 and DRB1*14.

Adolescent↗

PubMed1994

Effect of head up tilt on cerebral circulation.

This study was performed to study the effect of the head up tilt (HUT) on cerebral circulation across the time course (60 degrees HUT for 15 minutes) and across the different angles of HUT (15, 30, 45, 60 degrees HUT for 15 minutes). Cerebral circulation was continuously monitored during 15 minutes of HUT by the carotid Doppler flow meter, the transcranial Doppler flow meter, and the near infra-red spectrophotometer. The results show that the cerebral blood flow decreased during HUT and that the cerebral blood volume decreased initially and then gradually increased. And the magnitude of the effect may have the relationship with the angles of the HUT.

Blood Pressure↗

PubMed1994

Individual differences of cerebrovascular responses to gravitational stress--prediction of orthostatic intolerance.

This experiment was designed to investigate the individual differences in the cerebrovascular responses to orthostatic stress. Seven male volunteers were exposed to head-up tilt (HUT) at 60 degrees for 15 min and to lower body negative pressure (LBNP) at 30 mmHg for 25 min. We measured the flow velocity of the middle cerebral artery and the quantity of the oxygenated and deoxygenated hemoglobin (oxy-Hb and deoxy-Hb) in the brain. Based upon oxy-Hb change during exposure to HUT, we classified the subjects into two groups: 1) the "good responder" group in which the oxy-Hb gradually increased from the 5th to 10th minute of HUT; 2) the "bad responder" group in which the oxy-Hb stabilized at lower levels after the initial decrease. The oxy-Hb changes between the two groups were significantly different during exposure to LBNP. During exposure to HUT and LBNP, no significant difference was observed in blood pressure and heart rate between the two groups. Our results suggest that there might be an individual difference in the cerebrovascular responses to orthostatic stress.

Adult↗

PubMed1994

Platelet 3H-paroxetine binding in control subjects and depressed patients: relationship to serotonin uptake and age.

3H-paroxetine is regarded as a better ligand for the serotonin (5-hydroxytryptamine; 5-HT) uptake site than 3H-imipramine. In the present study, platelet 14C-5-HT uptake and 3H-paroxetine binding were simultaneously measured in 12 control subjects. There was a significant positive correlation between the individual Bmax value for 3H-paroxetine binding and the Vmax value for 14C-5-HT uptake. Platelet 3H-paroxetine binding was also determined in 21 drug-free patients who satisfied DSM-III-R criteria for major depression and 21 control subjects. A negative correlation was found between the Bmax values for 3H-paroxetine binding with age in control subjects. There was no change in 3H-paroxetine binding in depressed patients compared with control subjects. Our results indicated that 3H-paroxetine was a good ligand for evaluating 5-HT uptake sites, and the influence of age ought to be taken into consideration in the study of 3H-paroxetine binding. The present study indicated that there was no change in 5-HT uptake sites in platelets from depressed patients.

Adult↗

PubMed1994

Effects of difference in amount of exercise training on prevention of diabetes mellitus in the Otsuka-Long-Evans-Tokushima fatty rats, a model of spontaneous non-insulin-dependent diabetes mellitus.

Exercise training every day has been shown to be effective in preventing the development of non-insulin-dependent diabetes mellitus (NIDDM) in a model rat (Otsuka Long Evans Tokushima Fatty (OLETF)). For determination of whether less vigorous exercise training also has a protective effect against the development of NIDDM in this model, seven male OLETF rats each were assigned to training every other day, every 3 days and every 7 days from 6 to 30 weeks of age. At 30 weeks of age, rats trained every other day, 3 days, 7 days and sedentary rats weighed averages of 547, 548, 603 and 695 g and had abdominal fat deposits of 28, 24, 32 and 72 g, respectively. The mean meterages of running of rats trained every other day, 3 days and 7 days over the whole experimental period were 9630, 5166 and 1685 m/week, respectively. At 30 weeks of age, the cumulative incidence of NIDDM in sedentary rats was 85.7% (6/7), while none of the trained rats became diabetic except for one of rats trained every 7 days. The glucose infusion rate (GIR), an index of insulin sensitivity, in the group trained every 7 days, 60.6 +/- 5.0 mumol.kg-1.min-1, was significantly greater than that in the sedentary group, 21.7 +/- 1.7 mumol.kg-1.min-1. Morphological studies on the pancreas of rats trained every other day and every 3 days showed minimal changes of islets, whereas sections of islets from rats trained every 7 days appeared enlarged and fibrotic, though significantly less so than the islets of sedentary rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1994

Inhibitory effects of daunorubicin on endothelium-dependent vasorelaxing response to acetylcholine of rat aorta.

The effect of daunorubicin on the endothelium-dependent vasorelaxing response to acetylcholine was investigated using rat isolated aorta and compared with the effect of aclarubicin. Treatment of aortic strips with daunorubicin (20 microM) significantly attenuated the relaxing response to acetylcholine in the absence of tetraethylammonium, but not in its presence. Pretreatment with daunorubicin at a higher concentration (50 microM) or with aclarubicin (20 microM) strongly attenuated the relaxing response to acetylcholine; this attenuation was unaffected by the presence of tetraethylammonium. The increase in aortic cGMP in response to acetylcholine was also significantly suppressed by pretreatment with 50 microM daunorubicin or 20 microM aclarubicin, but not by treatment with 20 microM daunorubicin. The inhibitory effect of 20 microM aclarubicin on the acetylcholine-induced responses was stronger than that of 50 microM daunorubicin. Even in strips pretreated with both 50 microM daunorubicin and 20 microM aclarubicin, relaxation induced by 0.1 microM sodium nitroprusside was retained. These results suggest that daunorubicin at 20 microM inhibits the endothelium-dependent vasorelaxing response to acetylcholine via a mechanism other than the nitric oxide-mediated pathway, whilst at 50 microM, it inhibits the nitric oxide-mediated vasorelaxation.

Acetylcholine↗

PubMed1994

A case-control study on risk factors for leukemia in a district of Japan.

A case control study was performed with 142 leukemia patients and 284 controls matched for age and sex. Occupation, birth order, past medical history, and drinking and smoking habits were compared in these two groups. Persons born first or fourth were found to have a higher incidence of leukemia. History of a fracture was one of the risk factors for acute leukemia, and a history of gastroduodenal ulcer was a risk factor for chronic leukemia. This may suggest that extensive exposure to X-rays in diagnosis and treatment is a risk factor for leukemia. There was a significant dose-response relationship between the amount of smoking and the incidence of acute nonlymphocytic leukemia, but not between the amount of alcohol consumption and the incidence of leukemia. Thus, smoking was one of the risk factors for acute leukemia.

Aged↗

PubMed1994

[An epidemiological study on the relationship between irascibility and serum lipid level in rural inhabitants].

From the viewpoint of prevention of cerebrovascular disease, we examined the relationship between irritable persons (CMI, Q-180 positive) and the levels of serum triglyceride (TG), total cholesterol (T-chol), HDL-cholesterol among farmers, part-time farmers and non-farmers among 1075 inhabitants, consisting of 306 males with a mean age of 54, and 76 females with a mean age of 49, in a rural area with a high frequency of apoplex. Since the levels of serum TG, T-chol, HDL-chol in male farmers showed the same pattern as that of female part-time farmers, it seemed that the female farmers were working as heavily as the male farmers. Irritable male farmers showed a higher level of TG and lower level of HDL-chol than other personalities. However, irritable female farmers showed significantly lower levels of TG or higher level of HDL-chol than that of other personalities. Obesity measured by BMI of irritable persons showed the same level among occupations in male farmers. Also there was no difference in BMI levels of irritable persons among female part-time farmers and non-farmers. Irritable male farmers showed higher levels of TG and lower levels of HDL-chol than non-farmers and showed the same level of T-chol. The levels of these parameters in non-farmers showed the same levels as in the rural inhabitants. The levels of TG and HDL-chol of irritable male farmers were higher and that of T-chol was lower than those of irritable non-farmers.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1994

Serum sialic acid concentration and atherosclerotic risk factors.

To clarify the significance of increased blood sialic acid in atherosclerotic cardiovascular disease, we investigated the relationship between serum sialic acid level and atherosclerotic risk factors such as serum uric acid, fasting blood glucose, systolic and diastolic blood pressure, atherogenic index, and white blood cell count. By simple regression analysis, the serum sialic acid level was found to correlate significantly with these parameters. The mean sialic acid level was significantly higher in the highest quartile for serum uric acid than in its lowest quartile and also for fasting blood glucose concentration in comparison with its other three quartiles. A tendency was noted for the mean serum sialic acid level of each quartile to become higher with an increase in the quartiles of systolic or diastolic blood pressure, atherogenic index, and white blood cell count. Multiple regression analysis showed the correlations to be significant for the relationship of serum sialic acid to atherogenic index, mean arterial pressure and white blood cell count. From these results and previous findings of higher serum sialic acid levels in smokers, patients with diabetic angiopathies, and patients with hyperlipidemia, it is suggested that serum sialic acid reflects the degree of atherosclerotic progress involving inflammation processes.

Adult↗