Search PubMed⌕ Search

Biomedical subjects

M Sano

Publications and source records attributed to M Sano.

At least 271 records · Page 15Linked to original sources
PubMed1995

Site-specific effects of testosterone propionate on the prostate of rat pretreated with 3,2'-dimethyl-4-aminobiphenyl: dose-dependent induction of invasive carcinomas.

It has been shown that testosterone propionate (TP) strongly promotes induction of invasive carcinomas in previously initiated accessory sex organs. In this study, in order to clarify the dose-dependence of this promotion, TP was given at 3 different levels (high, medium or low doses) using different sizes (2, 1 and 0.5 cm long) of Silastic tube for 40 weeks after administration of 3,2'-dimethyl-4-aminobiphenyl to male F344 rats. The data showed development of invasive carcinomas in the dorso-lateral and anterior prostate and in the seminal vesicle to be dose-dependent with the high dose of TP being most effective for tumor induction. Average levels of serum testosterone were approximately 800, 600, 300 and 150 ng/dl in rats given the high to low doses and in control rats, respectively. Development of neoplastic lesions in the ventral prostate demonstrated an inverse dependence on the dose of TP. These findings, together with previous data, suggest that the tumor-promoting potential of TP on rat prostate is unlikely to be simply due to its androgenic action and other factors should also be considered.

Aminobiphenyl Compounds↗
PubMed1995

Modification by analgesics of lesion development in the urinary tract and various other organs of rats pretreated with dihydroxy-di-N-propylnitrosamine and uracil.

Effects of the analgesics phenacetin, acetaminophen and antipyrine on lesion development in the urinary tract and other organs in male F344 rats were investigated. Animals were concurrently administered with 0.1% dihydroxy-di-N-propylnitrosamine (DHPN) in drinking water and 3.0% uracil in the diet for 4 weeks and then, starting 1 week after the cessation of this treatment, received basal diet or diet containing phenacetin, acetaminophen or antipyrine for 35 weeks. The occurrences of renal cell tumors were increased in the groups given phenacetin or antipyrine, as compared with the DHPN + uracil alone controls. Antipyrine, but not the two other compounds, also enhanced development of hyperplastic lesions in the renal pelvis and ureter. In the urinary bladder, phenacetin and antipyrine treatments were both associated with increased incidence of preneoplastic or neoplastic lesions. Furthermore, phenacetin alone, without the initiating agent pretreatments, induced simple hyperplasias of the urinary bladder at high incidence. Antipyrine enhanced induction of hyperplastic lesions in the ureter and was also found to increase the incidences of preneoplastic and neoplastic lesions in the liver. Although decreased incidences of tumor development of lung and thyroid were observed for the group given phenacetin, this might have been linked to the decreased weight gain. The results confirmed that combination treatment with DHPN + uracil is effective for wide-spectrum initiation of carcinogenesis in the urological tract and demonstrated significant modification potential for both phenacetin and antipyrine.

Acetaminophen↗
PubMed1995

Cerebral metabolism of oxygen and glucose in a patient with MELAS syndrome.

We studied cerebral oxygen and glucose metabolism as well as cerebral blood flow using positron emission tomography (PET) in a case with MELAS showing dementia, diabetes mellitus, ataxia and lactic acidosis without any signs of stroke. This case, confirmed to have a point mutation at position 3243 in the transfer RNA gene of mitochondrial DNA, developed a stroke-like episode 8 months after the PET study. Uncoupling was observed between cerebral oxygen metabolism and cerebral blood flow with reduced fractional oxygen extraction ratio, indicating "hyperemia", not ischemia. The "hyperemia" may be closely related to the malfunction of mitochondria in aerobic energy production. A drastic decrease in cerebral oxygen metabolism (CMRO2) was found globally in contrast to preserved cerebral glucose metabolism (CMRglu), resulting in a remarkable decrease in the metabolic ratio (CMRO2/CMRglu). The dissociation between cerebral glucose and oxygen metabolism may be characteristic of MELAS.

Adult↗
PubMed1995

Tokishakuyakusan effect on DNA polymerase alpha activity in relationship to DNA synthesis before and/or after the LH/FSH surge in rats.

DNA polymerase alpha activity in ovaries of mature cycling rats during the normal estrous cycle changed in a cyclic manner with a peak at 1800 h in proestrus. Tokishakuyakusan (TS) in vivo did not affect the changes in DNA polymerase alpha and beta activities during the estrous cycle. LH and FSH at 1000 or 1700 h in proestrus increased DNA polymerase alpha activity, but the DNA polymerase alpha activity induced by LH or FSH was not significantly affected by the addition of TS. DNA polymerase beta activity did not change with LH, FSH or TS. In PMS-treated or -untreated immature rats, TS enhanced ovarian DNA polymerase alpha activity but had no significant effect on LH or FSH action. In ovaries, incubated in vitro, in untreated mature or immature rats, TS enhanced ovarian DNA polymerase alpha activity but had no significant effect on LH or FSH action. These results suggest that TS stimulates ovarian DNA polymerase alpha activity in relationship to DNA synthesis and does not affect the effect of LH or FSH on the activity by preovulatory follicle before and/or after the LH/FSH surge.

Animals↗
PubMed1995

Neuropsychological changes in a prospectively followed cohort of homosexual and bisexual men with and without HIV infection.

We evaluated neuropsychological test performance of 168 homosexual and bisexual men with and without human immunodeficiency virus (HIV) infection (113 HIV+ subjects and 55 HIV- controls) over 4.5 years of semiannual follow-up. Analyses of the longitudinal data were performed by applying generalized estimating equations (GEEs) to regression analyses with repeated measures. Compared with the HIV- men, the HIV+ subjects performed more poorly on memory testing. Performance on all tests tended to improve over time, but this improvement was attenuated or eliminated in the HIV+ group for tests of language and attention. Within the HIV+ subjects, improvement over time in tests of memory, executive function, language, and attention was attenuated or eliminated in patients with lower CD4 levels; more advanced HIV disease was associated with poorer memory and executive function and with attenuated or reduced learning effects for memory, motor speed, and language tests. Clinically significant neurologic findings were associated with worse memory and orientation and with attenuated or reversed learning effects for memory, language, and attention tests. There were 33 deaths in the HIV+ group. In the men who died, there was more rapid decline in executive, language, and attentional test performance. These observations remained significant after controlling for HIV disease severity. We conclude that HIV infecting the CNS results in progressive cognitive change that is closely associated with neurologic findings. In addition, our findings suggest a relation between more rapid cognitive progression and death.

Adult↗
PubMed1995

Neuropsychological detection and characterization of preclinical Alzheimer's disease.

We attempted to characterize the changes in cognition associated with the earliest, or preclinical, stages of Alzheimer's disease (AD) by administering a comprehensive neuropsychological test battery to a group of initially nondemented older adults participating in a prospective epidemiologic study of dementia. Using Cox regression analyses, we examined the associations between baseline neuropsychological test scores and subsequent development of AD. Results confirmed preliminary findings that baseline scores on the Boston Naming Test, Immediate Recall on the Selective Reminding Test, and the Similarities subtest of the Wechsler Adult Intelligence Scale-Revised were significantly and independently associated with later diagnosis of AD. Analyses controlled for the effects of age, education, sex, and language of test administration. These results lend support to the notion of a preclinical phase of AD and indicate that this very early stage of AD is characterized by poor word-finding ability, abstract reasoning, and memory.

Aged↗
PubMed1995

Neuropsychological characteristics of preclinical dementia in Parkinson's disease.

The goal of this study was to characterize the changes in cognition associated with the earliest, or preclinical, stages of dementia in Parkinson's disease (PD). We administered a comprehensive neuropsychological test battery to a group of initially nondemented PD patients participating in a longitudinal community-based epidemiologic study. We used Cox proportional hazards models to assess the relative risk of incident dementia associated with baseline scores on the neuropsychological tests. Baseline performance on two verbal fluency tasks (letter fluency and category fluency) was significantly and independently associated with incident dementia. Tests of memory, orientation, abstract reasoning, naming, and constructional skill were less sensitive predictors of subsequent dementia. The neuropsychological pattern characterizing the preclinical stages of dementia in PD differed from that described previously in preclinical Alzheimer's disease. Results suggest that poor performance on tests of verbal fluency may represent a distinct characteristic of the preclinical phase of dementia in PD.

Aged↗
PubMed1995

Effects of various natural antioxidants on the Cu(2+)-mediated oxidative modification of low density lipoprotein.

We have reported in our previous paper that several flavan-3-ol derivatives (tea polyphenols) inhibited the Cu(2+)-mediated low density lipoprotein (LDL) oxidation in vitro. (-)-Epigallocatechin gallate (EGCG), in particular, exhibited strong inhibition. In this study, we have compared the antioxidative effects of EGCG with those of other natural antioxidants, such as flavonols, sesaminol, curcuminoid derivatives, tocopherol analogues and theaflavins. The antioxidative effects were monitored by conjugated diene formation in LDL which was carried out at 37 degrees C with 5 microM CuSO4 with or without antioxidants. Dibutyl hydroxytoluene (BHT) was used as a reference compound. The lag-time before the onset of conjugated diene formation was more than 100 min in the presence of 0.5 microM EGCG, theaflavin, myricetin, quercetin, and sesaminol. The ability to prolong the lag-time was in the order of sesaminol > quercetin > EGCG > theaflavin > or = myricetin > BHT > alpha-tocopherol. Among the 4 tocopherol analogues used, alpha-tocopherol showed the strongest antioxidative activity. We have also studied the effects of EGCG, BHT, and alpha-tocopherol on cholesteryl and alpha-tocopherol on cholesteryl ester (CE) degradation and apolipoprotein B 100 (apo B 100) fragmentation in the Cu(2+)-mediated oxidative modification of LDL. EGCG was the most effective inhibitor of CE degradation and apo B 100 fragmentation.

Antioxidants↗
PubMed1995

Effect of tea (Camellia sinensis L.) on lipid peroxidation in rat liver and kidney: a comparison of green and black tea feeding.

The antioxidant effects in the liver and kidney obtained from rat fed diets containing 3% green or black tea leaf powder, which were prepared from the same lot tea leaves, were studied using the tissue slice-antioxidant evaluation method with two lipid peroxidation inducers. After 50 d on the diets, liver slices prepared from green and black tea-supplemented rats showed significant inhibitory effects against tert-butyl hydroperoxide-induced lipid peroxidation. These effects, however, were not proportional to the amounts of (-)-epicatechins and antioxidant vitamins in the tea leaves. In the kidney, the antioxidant effect was observed only in the green tea-fed group. A similar antioxidant effect on the kidney was observed after oral administration of a major tea polyphenol, (-)-epigallocatechin gallate (50 mg/kg body weight for 7 d). Liver slices from black tea-fed rats also inhibited bromotrichloromethane-induced lipid peroxidation. These results demonstrated that dietary green and black tea had antioxidant effects on tissue lipid peroxidation ex vivo.

Animals↗
PubMed1995

The determination of clinically meaningful cognitive decline: development and use of an alternative method.

Statistical methods traditionally used in the analysis of change (e.g., repeated measures ANOVA) may be inadequate for the investigation of cognitive decline if a study's effect size is small, the variance within groups is heterogeneous, or the statistical power is low. To examine an alternative approach to the determination of clinically meaningful cognitive decline and investigate whether such decline occurs during the first year after stroke, we administered a neuropsychological test battery to 172 patients (age = 70.3 +/- 7.6 years; education = 10.3 +/- 4.7 years) 3 and 12 months after stroke and 199 nondemented stroke-free control subjects (age = 71.1 +/- 6.4 years; education = 12.8 +/- 4.2 years) on two occasions 12 months apart. Two neuropsychologists classified each subject's test performance as having declined, improved, or remained stable based solely on clinical judgment. Reliability of the rating of decline versus the pooled rating of improvement/stability was excellent (kappa = 0.79). The two rating groups differed significantly and in the appropriate directions in change on most tests. While a MANOVA comparing the stroke and control groups on change in test scores was not significant, logistic regression analysis determined that a rating of clinically meaningful cognitive decline was associated with stroke status (Odds Ratio = 1.8, 95% Confidence Interval = 1.0 to 3.2), while adjusting for demographic factors. We propose that this alternative approach to the analysis of cognitive change can facilitate the recognition of decline in subgroups of subjects. It would be valuable as an adjunct to studies of the incidence of dementia, for example, in which the recognition of cognitive decline might be difficult in highly educated patients whose baseline level of performance is far above the cutoffs operationalized for the diagnosis of dementia.

Journal Article↗
PubMed1995

[A surgically treated case of ventrally exophytic pontine glioma].

A surgically treated case of ventrally exophytic pontine glioma is reported. A 49-year-old woman, complaining of dysarthria, dysphagia and gait disturbance, was admitted to our department. Her past history included bronchial asthma. Plain skull x-p and tomography revealed destruction of the dorsum sellae and upper clivus. CT demonstrated an enhanced oval mass at the ventral side of the upper brainstem. The mass was severely compressing the brainstem dorsally. MRI revealed a low-intensity band between the tumor and the brainstem. Dynamic MRI demonstrated a pattern of rapid increasing and slow reduction. Cerebral angiogram demonstrated a paradoxical sign that pontine branches were located anterior to the basilar artery. The finding demonstrated that the tumor was an intraaxial mass. The first operation was performed by the orbitofrontomalar approach. On the trans-sylvian route, the tumor was removed partially with CUSA and neuronavigation system. Its histology was astrocytoma grade III. Radiation therapy was added. The patient's symptoms aggravated again. On the second operation, the transtemporal route with tentorial resection was chosen. Under a wide visual field, intracapsular subtotal resection of the tumor was performed. Interferon therapy was added. She was discharged to her home with no neurological deficits. Ventrally exophytic pontine glioma is very rare. Low-intensity band of MRI, a sign of extraaxial mass, was visualised in our case. On the other hand, cerebral angiogram demonstrated a paradoxical sign. This sign suggested that the tumor originated from the brainstem. With update skull base surgery and neuronavigation system, surgical therapy of ventrally exophytic pontine glioma is safe and effective.

Brain Neoplasms↗
PubMed1995

[A hemodialysis patient with HTLV-1-associated myelopathy (HAM)].

We report here a case of maintenance hemodialysis with HTLV-1 associated myelopathy (HAM). A 53-year-old female hemodialysis patient was admitted to Teikyo University Ichihara hospital because of paralytic ileus. She had a history of blood transfusion and had been under dialysis treatment for 8 years. She had experienced gait disturbance and sensory disturbance in her lower extremities for 8 years. Neurological examination revealed myelopathy and neuropathy. Laboratory data revealed that serum anti-HTLV-1-antibody was over 1260 x (PA) and liquor HTLV-1-antibody was over 160 x (PA). Her liquor revealed a cell count of 4/3 cmm, protein 22 mg/dl, glucose 45 mg/dl, chloride 125 mEq/l and no atypical cells. To the best of our knowledge this is a rare case in Japan. Our findings suggest that HAM should be taken into consideration when we diagnose a maintenance hemodialysis patient showing neuropathy and myelopathy.

Female↗
PubMed1995

[A case of hemorrhagic mixed cerebrovascular malformation of the brainstem draining through a transpontine vein].

A case of mixed cerebrovascular malformation of the brainstem with pontine hemorrhage is reported. The mixed cerebrovascular malformation was composed of medullary venous malformation, one hemorrhagic and another non-hemorrhagic mass. The latter masses were thought to be cavernous venous malformations by their MR findings. The medullary venous malformation drained to the anterior pontomesencephalic vein through a transpontine vein. A 70-year-old man, complaining of aggravation of left hemiparesis, was admitted to our department. His past history included traumatic cervical myelopathy and diabetic neuropathy. CT revealed a pontine hemorrhage with linear enhancement. Depending on MRI findings, the hemorrhage was thought to be an intratumoral hemorrhage within the cavernous venous malformation. Cerebral angiogram demonstrated medullary venous malformation. The malformation drained to the anterior pontomesencephalic vein through a transpontine vein. The linear enhancement was the transpontine vein itself. Medullary venous malformations in the brainstem are rare. With MRI, the transpontine vein is thought to be a characteristic feature of medullary venous malformation of the brainstem. We suggest that most cases of hemorrhagic medullary venous malformations are mixed cerebrovascular malformations. We emphasize the need for precise examination of other types of vascular lesions coexisting with medullary venous malformations.

Aged↗
PubMed1995

[A case of complex brain anomaly with arachnoid cyst treated well by cyst-cisternal shunt].

A rare case of complex anomaly, composed of schizencephaly, polymicrogyria, heterotopic gray matter, agenesis of the septum pellicidi and arachnoid cyst at the right middle cranial fossa was encountered. A 38-year old man, complaining of epileptic seizure, was admitted to our department. His past history included cerebral palsy. Plain skull roentgenogram showed protrusion of the right temporal bone and thinning of the ipsilateral sphenoidal wing. CT revealed arachnoid cyst and parietal crest surrounded by cortical layer on the right side. MRI also demonstrated the arachnoid cyst, parietal crest and agenesis of septum pellicidi. MRI, especially proton density weighted image, well demonstrated cortical layer surrounding the parietal crest, right opercular polymicrogyria and left heterotopic gray matter. The crest was diagnosed as schizencephaly. The arachnoid cyst was treated by cyst-cisternal shunt with a silicone tube (Sapporo shunt) after fenestrating the cyst. The tube was inserted into the sylvian fissure from the cyst and sutured to the inner wall of the cyst. Despite slight intratumoral hemorrhage in the CT at 1.5 months after the operation, the cyst markedly decreased in size. As to the diagnosis of the brain anomaly, MRI gives extremely useful information. Particularly for the diagnosis of anomalies of migration of neuronal cells, MRI, especially proton density weighted image, has been regarded as an indispensable examination. In the operation of subarachnoid cyst, to maintain the flow between the inside of its cyst and the basal cistern, cyst-cisternal shunt with a silicone tube had satisfactory results.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

[An adult case of hemolytic uremic syndrome (HUS) after pathogenic Escherichia coli (E. coli) infection].

In recent years, it has been revealed that verocytotoxin-producing E. coli (VTEC) infection is one of the leading causes of HUS and the molecular aspects of its pathophysiology have also been studied extensively. We report a case of a 56-year-old man who developed HUS after E. coli (O 26 strain) infection with diarrhea. The characteristic laboratory findings in this case included hypergammaglobulinemia, hypocomplementemia and a high level of immune complex in addition to the common findings of HUS. The light microscopic findings of the first renal biopsy performed before treatment revealed extensive interstitial changes with remarkable mononuclear cell infiltrations as well as mild mesangial proliferation with crescent formation. Subendothelial electron-dense deposits within the glomerular capillary walls and mesangial area were also detected by electron microscopic examination. The diagnostic possibilities of infectious endocarditis and collagen diseases, such as Sjögren syndrome, were reasonably ruled out by the appropriate examinations. After 2-month prednisolone therapy, proteinuria and deteriorated renal functions as well as the abnormal immunological parameters described above were remarkably improved. The second renal biopsy after treatments showed clearly diminished subendothelial deposits and interstitial mononuclear cell infiltrations. This case report might provide information on the unique features of renal interstitial damage and immunological abnormalities in VTEC-induced adult HUS.

Bacterial Toxins↗
PubMed1995

[Peripheral T-cell lymphoma with abundant ATL-like cells in the blood].

A 69-year-old woman was admitted to our hospital because of leucocytosis and systemic lymphadenopathy. On admission, white blood cell count was 163,000/microliters, most of which consisted of flower-like cells with convoluted nuclei in the peripheral blood. In the abnormal lymphocyte cells surface-marker test by flow cytometry showed that they expressed CD2, CD3, CD4, CD29, CD45RA, and CD38, but not CD8, CD16, and CD25. Serum anti-Human T-lymphotropic virus type-I (HTLV-I) antibody was negative in particle agglutination, enzyme-linked immunosorbent assay (ELISA) and western-blotting assay. HTLV-I proviral DNA in the abnormal lymphocyte cells was not detected by southern blotting hybridization technique. Moreover, HTLV-I provirus was not detected using a polymerase-chain-reaction (PCR). A monoclonal rearrangement of the TCR-beta chain gene was evident by using DNA probe in southern blot hybridization. Because of the rapid progress of the disease, chemotherapy was started immediately after admission. Though, this patient became refractory, and she died about 1 year after admission.

Aged↗
PubMed1995

Carcinogenicity of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) in rats: dose-response studies.

The carcinogenic potential of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), identified as the most abundant mutagenic heterocyclic amine in cooked meat and fish, was investigated in dose-response studies. Six-week-old F344 rats of both sexes were administered PhIP in the diet at concentrations of 0, 25, 100, or 400 ppm for up to 104 weeks. Animals receiving the highest dose were killed at week 52 due to marked retardation in body weight gain. PhIP was demonstrably carcinogenic for the colon in males and for the mammary glands in females, in a clear dose-dependent manner for both cases. Mammary carcinogenicity of PhIP was also confirmed in female SD rats with a clear dose-response relationship. In rat two-stage carcinogenicity models, PhIP exerted tumor-promoting activity in the small intestine as well as in the large intestine, but no promoting effects were apparent in the liver, although DNA adducts were formed dose dependently. The virtually safe dose (VSD) at the 10(-6) risk level calculated from the long-term carcinogenicity test was 0.023-0.52 ppm in the diet. This range of values is very close to or lower than human intake in daily life. Since PhIP is a most abundant heterocyclic amine and its carcinogenic organotropism overlaps with the types of neoplasias most commonly observed in western countries, the compound is likely to be extremely important with respect to human cancer development.

Adenocarcinoma↗