Search PubMed⌕ Search

Biomedical subjects

Y Mizuno

Publications and source records attributed to Y Mizuno.

At least 91 records · Page 5Linked to original sources

Seaweed prevents breast cancer?

To investigate the chemopreventive effects of seaweed on breast cancer, we have been studying the relationship between iodine and breast cancer. We found earlier that the seaweed, wakame, showed a suppressive effect on the proliferation of DMBA (dimethylbenz(a)anthracene)-induced rat mammary tumors, possibly via apoptosis induction. In the present study, powdered mekabu was placed in distilled water, and left to stand for 24 h at 4 degrees C. The filtered supernatant was used as mekabu solution. It showed an extremely strong suppressive effect on rat mammary carcinogenesis when used in daily drinking water, without toxicity. In vitro, mekabu solution strongly induced apoptosis in 3 kinds of human breast cancer cells. These effects were stronger than those of a chemotherapeutic agent widely used to treat human breast cancer. Furthermore, no apoptosis induction was observed in normal human mammary cells. In Japan, mekabu is widely consumed as a safe, inexpensive food. Our results suggest that mekabu has potential for chemoprevention of human breast cancer.

9,10-Dimethyl-1,2-benzanthracene↗

Occurrence of transsulfuration in synthesis of L-homocysteine in an extremely thermophilic bacterium, Thermus thermophilus HB8.

A cell extract of an extremely thermophilic bacterium, Thermus thermophilus HB8, cultured in a synthetic medium catalyzed cystathionine gamma-synthesis with O-acetyl-L-homoserine and L-cysteine as substrates but not beta-synthesis with DL-homocysteine and L-serine (or O-acetyl-L-serine). The amounts of synthesized enzymes metabolizing sulfur-containing amino acids were estimated by determining their catalytic activities in cell extracts. The syntheses of cystathionine beta-lyase (EC 4.4.1.8) and O-acetyl-L-serine sulfhydrylase (EC 4.2.99.8) were markedly repressed by L-methionine supplemented to the medium. L-Cysteine and glutathione, both at 0.5 mM, added to the medium as the sole sulfur source repressed the synthesis of O-acetylserine sulfhydrylase by 55 and 73%, respectively, confirming that this enzyme functions as a cysteine synthase. Methionine employed at 1 to 5 mM in the same way derepressed the synthesis of O-acetylserine sulfhydrylase 2.1- to 2.5-fold. A method for assaying a low concentration of sulfide (0.01 to 0.05 mM) liberated from homocysteine by determining cysteine synthesized with it in the presence of excess amounts of O-acetylserine and a purified preparation of the sulfhydrylase was established. The extract of cells catalyzed the homocysteine gamma-lyase reaction, with a specific activity of 5 to 7 nmol/min/mg of protein, but not the methionine gamma-lyase reaction. These results suggested that cysteine was also synthesized under the conditions employed by the catalysis of O-acetylserine sulfhydrylase using sulfur of homocysteine derived from methionine. Methionine inhibited O-acetylserine sulfhydrylase markedly. The effects of sulfur sources added to the medium on the synthesis of O-acetylhomoserine sulfhydrylase and the inhibition of the enzyme activity by methionine were mostly understood by assuming that the organism has two proteins having O-acetylhomoserine sulfhydrylase activity, one of which is cystathionine gamma-synthase. Although it has been reported that homocysteine is directly synthesized in T. thermophilus HB27 by the catalysis of O-acetylhomoserine sulfhydrylase on the basis of genetic studies (T. Kosuge, D. Gao, and T. Hoshino, J. Biosci. Bioeng. 90:271-279, 2000), the results obtained in this study for the behaviors of related enzymes indicate that sulfur is first incorporated into cysteine and then transferred to homocysteine via cystathionine in T. thermophilus HB8.

Culture Media↗

Polymorphism of the lipoprotein lipase gene and risk of atherothrombotic cerebral infarction in the Japanese.

BACKGROUND AND PURPOSE: Lipid and lipoprotein abnormalities have been implicated in the pathogenesis of ischemic cerebrovascular disease and atherosclerosis. Lipoprotein lipase (LPL) plays an important role in plasma lipoprotein metabolism. Several studies have recently reported the presence of a relationship between Ser447Stop mutation of LPL and coronary artery disease. Other polymorphisms (HindIII and PvuII) of the LPL gene have already been shown to correlate significantly with dyslipidemia. We investigated whether these polymorphisms are associated with increased risk of ischemic cerebrovascular disease (CVD). METHODS: We recruited 177 CVD patients (atherothrombotic infarction, n=71; cardioembolic infarction, n=30; lacunar infarction, n=76) and 177 healthy control subjects. Subjects were genotyped for the Ser447Stop mutation and for HindIII/PvuII restriction fragment length polymorphisms of the LPL gene, and the findings were investigated for associations with the clinical subtypes of CVD and with lipid levels. RESULTS: The Ser447Stop mutation correlated significantly with CVD (0.107 versus 0.158; P=0.035). For the CG+GG versus CC genotype, the odds ratio between control subjects and CVD patients with atherothrombotic infarction was 0.42 (95% CI, 0.18 to 0.99) (P=0.046). Serum HDL cholesterol and triglyceride levels did not correlate significantly with the Ser447Stop genotype. HindIII polymorphism correlated significantly with CVD (0.234 versus 0.169; P=0.031), but the frequency of PvuII polymorphism was not significantly different between groups. CONCLUSIONS: Our results suggest that the Ser447Stop mutation of the LPL gene is a novel genetic marker for low risk of atherothrombotic cerebral infarction.

Cerebral Infarction↗

Cardiac amyloidosis presenting as microvascular angina--a case report.

Cardiac amyloidosis usually presents with heart failure, but rarely leads to coronary insufficiency. The authors report a case of a 69-year-old Japanese woman with cardiac amyloidosis presenting as microvascular angina. She had exertional angina with positive exercise test and normal coronary angiograms. However, heart failure developed, and she died 3 years after symptom onset. On autopsy, coronary arteries were patent. In contrast to that of the epicardial coronary arteries, histologic examination of the heart revealed severe obstructive alterations of the intramural coronary arteries with amyloid. Furthermore, amyloid was present mainly in the endocardium and the intramural coronary arteries, but there was little present in the myocardium. This case was a rare AL amyloidosis. There have been only 4 reported cases of cardiac amyloidosis that presented with exertional angina, a positive exercise test, and normal coronary angiograms and histologic examination.

Aged↗

Digested bacterial cell powder (DBCP) as a source of reduced-form folates for pigs: use of a trimethoprim-resistant strain and the bioavailability of folates in DBCP.

The production of digested bacterial cell powder (DBCP) as a source of reduced-form folates for pigs was studied. Trimethoprim-resistant mutants of Brevibacterium lactofermentum ATCC 13869 accumulated a significantly higher amount of the reduced form of folate in the cells than the wild-type strain. DBCPs were prepared from the resistant mutant strain and the wild-type strain. The utilization of the reduced-form of folate in DBCP was evaluated by measuring the plasma folate level after orally administering DBCP to Göttingen minipigs. The folates in both DBCPs proved to have equally high bioavailability in the pigs.

Animals↗

Time-related changes of the cardiovascular system during maintenance anesthesia with sevoflurane and isoflurane in horses.

To clarify time-related changes in equine cardiovascular system during maintenance anesthesia (180 min, 1.2 minimum alveolar concentration) with sevoflurane (Sev-group) compared to isoflurane (Iso-group) as the basis for clinical use of Sev, horses were examined for the heart rate (HR), mean arterial pressure (MAP), cardiac index (CI), systemic vascular resistance (SVR) and pre-ejection period (PEP)/ejection time (ET) that is an index of the cardiac contractility. The HR was almost 30 beats/min in both groups without significant temporal change. MAP was significantly elevated with time but there was no significant difference between the groups. In the Sev-group, CI remained unchanged but the significant increase of CI with time was observed in the Iso-group. In the Sev-group SVR was significantly higher than that of the Iso-group and increased with time. No significant difference of PEP/ET was seen between the groups, but PEP/ET lowered with time in the Iso-group in association with prolonged ET. The results indicated that the time-dependent elevation of MAP in the Sev-group reflected increased SVR without increase of CI and that it reflected increased CI resulting from increased stroke volume in the Iso-group in association with lowered PEP/ET, that is, increased cardiac contractility.

Anesthesia, Inhalation↗

Passage of dextran magnetite nanoparticles through the subcupular space of the pigeon.

We examined the permeability of the subcupular space for endolymph flow in the pigeon. A new technique was developed in which nanoparticles consisting of dextran magnetite were attracted by use of a magnet, instead of injecting a dye solution. The method was revealed to prevent an excess pressure application by the injection of dye solution. The Berlin blue color resulting from the dextran magnetite nanoparticles was found mainly within the subcupular space contacting with the sensory hairs. Further formation of the Berlin blue was found within the sensory cells. The result supports the idea that the fluid passes through the subcupular space.

Animals↗

Cupular response and functional anatomy to pressure application in the pigeon.

In this study, horizontal semicircular canal of the pigeon was inserted with a microfill, 164 micrometers in outer diameter, to gauge the pressure change in the canal and to clarify two things. One is whether the endolymph passes through the crista ampullaris or not. The other is as to the space where the endolymph passes through in the crista ampullaris if the endolymph goes through the crista. The pressure applications were performed by using Evans blue solution and as a result three pressure groups, i.e., 1) high, 2) moderate and 3) low were discriminated. Our results suggest that the endolymphatic fluid passes through the subcupular space or the top of the crista ampullaris when the pressure is enough small like the head rotates in daily life. Accordingly we present a new hypothesis as to the functional anatomy of the cupula in contrast to current hypotheses e.g. drum membrane or revolving door.

Animals↗

Combination therapy including pentoxifylline for entero-Behçet's disease.

Behçet's disease is a chronic relapsing vasculitis characterized by recurrent aphthous oral and genital ulcerations with uveitis. Multiple organs can be involved. Entero-Behçet's disease is often uncontrollable, relapsing, and can cause acute intestinal bleeding or perforation. We utilized a combination therapy including 600 mg of pentoxifylline per day, in two doses, to treat three female patients and observed the subsequent changes in clinical symptoms, serum C reactive protein levels, and endoscopic findings. In all three patients, clinical symptoms as well as serum C reactive protein levels improved immediately. Endoscopically, lower intestinal lesions were significantly reduced or healed in all of them. Combination therapy including pentoxifylline appears to be clinically effective in the patients with entero-Behçet's disease.

Adult↗

[Aging society and an adult guardianship system].

Prior to recent revisions, civil law had established a system of interdict and quasi-incompetency. This system was begun in 1898 and, up until the revisions of April 2000, it had spanned more than one hundred years without undergoing any major changes. Statistically, there was a steady increase in the number of pronouncements and retractions of incompetency in recent years. A 1980 survey showed that people in their 40s were the most common, and that the proportions of psychiatric disorder, mental retardation, and dementia were of nearly the same level. A 1996 survey, in contrast, showed a greater proportion of elderly, with about half of cases being dementia or a vegetative state. The new adult guardianship system currently in place, as well as a voluntary guardianship system (enduring power of attorney), was established together with the change from the interdict/quasi-incompetency system to a system of assistance, curatorship, and guardianship. The care insurance system that was put in effect at the same time shifted from an enforcement system to a contract system, so the judgment ability of the person at the time of the decision to enter the contract has become an issue. Finally, in dealing with people with dementia, especially mild dementia, problems arise as to the best method of informed consent, including notifying people of their specific disease, and who should decide the treatment for incompetent people with dementia.

Adult↗

Generalized convulsions after consuming a large amount of gingko nuts.

We report a 36-year-old woman, without any past or family histories of epilepsy, who presented frequent vomiting and generalized convulsions. About 4 h before the convulsion, she had consumed approximately 70-80 gingko nuts, seeds of Gingko biloba, in an attempt to improve her health. It is important to know that convulsion may be induced if a large amount of gingko nuts is consumed. The neurotoxicity of gingko nuts, particularly their convulsion-inducing effect, should be recognized.

Adult↗

[A case of gastric cancer with liver metastases successfully treated with combination therapy of systemic and hepatic arterial infusion chemotherapy].

A 67-year-old man was admitted to our hospital because of advanced gastric cancer associated with metastases to the liver, the lymph nodes along the lesser curvature and the infradiaphragmatic lymph nodes. As we considered the primary lesion and the liver metastases to be unresectable, we treated him with combination therapy of systemic and hepatic arterial infusion chemotherapy. The regimen of systemic chemotherapy consisted of cisplatin (CDDP) and UFT. Hepatic arterial infusion chemotherapy included 5-fluorouracil (5-FU), doxorubicin (DXR) and mitomycin C (MMC). We repeated this therapy six times. The size of the primary lesion and the lymph node metastases decreased significantly after the chemotherapy. The size of the liver metastases did not change, but they appeared to necrotize. The patient maintained a good quality of life during the therapy. He finally died of peritonitis carcinomatosa 18 months after the diagnosis. This case indicated that combination therapy of systemic and hepatic arterial infusion chemotherapy was effective in cases of unresectable gastric cancer associated with liver metastases.

Administration, Oral↗

[An 84-year-old woman with progressive mental deterioration and abnormal behavior].

We report an 84-year-old woman with progressive mental deterioration. She was well until January 1994, when she was 80 years of the age. At that time she developed a delusional ideation, in that she stated that she would be killed by her fellow members of the society for elderly, in which she was belonging. At times, she closed the shutter of her house saying that a stranger was wandering outside of her house. In 1995, she could not identify the face of her son's wife. When she went out for shopping, she lost her way to the home. She prowled about in and out of her home. In 1996, she had to be admitted to a nursing home, where quarrelled with other patients and behaved violently. She was admitted to the neurology service of Hatsuishi Hospital on November 20th, 1997. Family history revealed that her mother was said to be demented. On admission, she was alert and behaved in a good manner. She was disoriented to the time and unable to do serial 7. Her memory was very poor. She did not show aphasia or apraxia. Cranial nerves appeared to be intact. She showed no weakness or muscle atrophy. Gait was normal for her age. Plastic rigidity was noted in four limbs more on the right side. No ataxia was noted. Deep tendon reflexes were exaggerated, however, no Babinski sign was noted. Sensory examination was intact. Her hospital course was characterized by the development of progressive gait disturbance, violent behaviour, and prowling around. On November 30th, 1998, she fell down and suffered from a fracture in the neck of her femur. Although replacement of the femur head was performed, she became unable to walk after this episode. Her mental functions deteriorated further. She developed pneumonia and expired on February 2, 1999. She was discussed in a neurological CPC and the chief discussant arrived at a conclusion that the patient probably had diffuse Lewy body disease, because of the combination of dementia and parkinsonism. Other possibilities discussed in the CPC included Pick's disease, frontotemporal dementia and parkinsonism, and Alzheimer's disease. Post-mortem examination revealed moderate atrophy in the frontal and temporal cortices. Microscopic examination showed atrophy and gliosis in the hippocampus. Many diffuse plaque and neuritic plaques were seen in the frontal cortex by methenamine silver staining. Neurofibrillary tangles were also found. The Meynert nucleus was preserved. The putamen and the substantia nigra were also intact. Pathologic diagnosis was consistent with Alzheimer's disease.

Aged↗

[Clinical features of myelitis in patients with atopic symptoms].

It is rare to see atopic symptoms in patients with multiple sclerosis(MS). However, it has been reported that in atopic patients, particularly in patients with atopic dermatitis, a benign myelitis occasionally occurs. In the present report, three atopic patients with myelitis were studied clinically and neuroradiologically. All the patients were adult men(Case 1, 2, and 3 were 41-year-old, 31-year-old, and 34-year-old, respectively), and all of them had bronchial asthma without histories of atopic dermatitis. Their manifestations were not severe and were only numbness of upper and/or lower extremities. There was no motor weakness, ataxia, or urinary incontinence. MRI studies revealed a T2-high intensity lesion in the high cervical spinal cord in the two patients(Case 2 and 3) and a T2-high intensity lesion in the lumber spinal cord in the remaining patient(Case 1). Their clinical courses were essentially all benign and well responsive to steroid therapy. Although myelitis of these patients may be a first attack of MS, their findings appear to support a recently emerging concept of the atopic myelitis.

Adult↗