Search PubMed⌕ Search

Biomedical subjects

K Kuramoto

Publications and source records attributed to K Kuramoto.

229 records · Page 13Linked to original sources
PubMedDate not supplied

Induction of ovarian tumors by heavy ion irradiation in B6C3F1 mice.

Six-week-old B6C3F1 mice were exposed to 0.439 Gy heavy ion irradiation as a 290 MeV/u carbon-ion beam (LET 10 keV/micron) at 2 cm from the upper proximal point of a spread Bragg beam and autopsied 13.5 months after the irradiation. In males total tumor incidences, mainly liver tumors, were 37.0% in irradiated group and 25.0% in control (P>0.05). In females the total tumor incidences were 32.3%, mainly ovarian tumors, in the irradiated group and 0% in the controls. These results indicate that heavy ion irradiation induces ovarian tumors in females but does not target any organ in males.

Adrenal Glands↗
PubMedDate not supplied

Influence of concomitant miso or NaCl treatment on induction of gastric tumors by N-methyl-N'-nitro-N-nitrosoguanidine in rats.

Six-week old male Sprague-Dawley (CD) rats were treated with 100 ppm N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) for 16 weeks in their drinking water with control, miso or sodium chloride (NaCl) supplemented diets. All animals were autopsied 12 months after the beginning of the MNNG treatment. Despite higher intake of MNNG in the high dose miso and NaCl groups, the total tumor incidences were decreased compared to middle and lowest values. The glandular stomach adenocarcinoma incidences in the 10% and 5% miso groups were significantly decreased as compared to those in the 2.2% or 1.1% NaCl groups, with the same concentration of NaCl.

Animals↗
PubMedDate not supplied

Elevated levels of inhibin-A and immunoreactive inhibin in aged male Wistar rats with testicular Leydig cell tumor.

This study was undertaken to investigate the endocrine changes that occur in male Tig:Wistar rats with Leydig cell tumors, with special reference to immunoreactive inhibin (ir-inhibin) and its dimeric forms. Adult male rats from 2 to 28 months of age were used. Blood samples were taken to measure plasma concentrations of ir-inhibin, inhibin-A, inhibin-B, 17beta-estradiol (E2), testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH). Inhibin bioactivity in both peripheral plasma and testicular extracts was also measured. Rats aged 18 months and older had testicular Leydig cell tumor. Testicular tissue sections from 27-month-old rats examined immunohistochemically showed strong positive staining for all 3 inhibin subunits, in particular inhibin alpha and betaA subunits, in the tumor cells. Plasma concentrations of ir-inhibin began to rise significantly (P < .05) at 18 months of age. High bioactivity of inhibin was detected not only in testicular extracts but also in peripheral plasma of aged rats. Thus, plasma concentrations of bioactive inhibin-A, but not inhibin-B, were significantly elevated with increasing age. The concentrations were significantly higher than those in normal male (P < .01) or normal female (P < .05) rats. Plasma concentrations of E2 were significantly (P < .05) elevated only at 23-24 months of age. A marked reduction (P < .05 to .001) in plasma LH and FSH concentrations was observed at 18 months of age and older. Plasma concentrations of testosterone were highest at 2 months of age and then decreased gradually and significantly (P < .05 to .001) afterward. Significant (P < .05 to .001) positive (testosterone vs LH) and negative (ir-inhibin vs FSH, ir-inhibin vs LH, and E2 vs FSH) correlations were observed. It is suggested that plasma inhibin-A levels are elevated in male Tig:Wistar rats with Leydig cell tumor, and thus inhibin-A may be used as a specific marker of testicular Leydig cell tumors. The present results also suggest that the age-related decline in plasma gonadotropins and thus testosterone levels in Tig:Wistar rats may be due to the development of tumors of the Leydig cells rather than to aging per se.

Aging↗
PubMedDate not supplied

An adenosine 3':5'-monophosphate-dependent protein kinase from human heart.

Protein kinase that phosphorylated histone and lesser amounts of protamine was demonstrated in human heart. It was activated three times by 10(-6) M cyclic adenosine 3':5'-monophosphate (cAMP) and by 10(-3) M other cyclic nucleotides. Km values for cAMP, ATP, Mg2+, and Co2+ were about 2 X 10(-8) M, 4 X 10(-5) M, 2 X 10(-3)M, and 1.7 X 10(-4) M, respectively. On DEAE cellulose column, the main peak of the enzyme eluted at high NaCl concentration. On Sephadex G-200 gel filtration the majority of the holoenzyme eluted at a peak corresponding to a molecular weight of about 300,000. There was an additional peak corresponding to a molecular weight of about 400,000, with relatively high cAMP binding compared to kinase activity. Right atrium and ventricle showed significantly higher enzyme activities than left atrium and ventricle and interventricular septum. On multivariate analysis of the enzyme activity versus 12 clinical and pathological findings of 122 cases, cardiac hypertrophy and coronary sclerosis were slight but significant negative contributors to the enzyme activity. Multiple correlation coefficient was low, indicating the enzyme activity remained at a relatively stable level, despite different clinical situations. This may be suitable for control of intracellular events through the membrane adenylate cyclase system.

Age Factors↗
PubMedDate not supplied

Lymphangiomatosis of bone--lymphographic and CT findings.

A case of lymphangiomatosis of bone associated with arachnoid cysts of the spinal cord is presented. This disease is very rare and in some cases the definitive diagnosis has been made radiologically rather than histologically. Lymphography and CT scanning showed on inflow of the oily contrast medium within the bony trabeculae. CT was also effective in detecting other anomalies that were otherwise not expected.

Adolescent↗
PubMedDate not supplied

Effect of perindopril on 24-hour blood pressure levels and hemodynamic responses to physical and mental stress in elderly hypertensive patients.

This study assessed the effects of an angiotensin-converting enzyme (ACE) inhibitor, perindopril, on the 24-hour blood pressure (BP) profile and hemodynamic responses to isometric exercise and mental stress in elderly hypertensive patients. We performed ambulatory BP monitorings and echocardiographic studies during hand-grip exercises and a mental stress test before and after the 10-week administration of perindopril in 11 elderly patients (mean age, 71.8 years). Office BP was significantly decreased by perindopril treatment. Both daytime and nighttime systolic BP decreased significantly without any change in circadian pattern (P < 0.05). Daytime diastolic BP was also significantly decreased by perindopril (P < 0.05); nighttime diastolic pressure was decreased, but this result was not statistically significant. The reduction in 24-hour BP was associated with a decreased left ventricular end-systolic dimension (P < 0.01) and an increased fractional shortening (P < 0.01), suggesting reduced afterload due to arterial dilatation. The left ventricular mass index was not changed by perindopril therapy, and neither were systolic and diastolic BP responses to the handgrip exercises. The increases in systolic BP during mental stress was augmented after perindopril therapy, although systolic BP during mental stress after treatment was significantly lower than before treatment (P < 0.05). These results indicate that perindopril is effective in reducing ambulatory 24-hour BP levels and is associated with improved systolic function caused by dilatation of resistance vessels.

Aged↗
PubMedDate not supplied

Metastatic tumors in irregular fatty liver mimicking focal sparing.

Two cases of hepatic metastatic tumor occurring in irregular fatty liver are reported. These metastatic tumors appeared as irregularly shaped hyperdense areas and were difficult to distinguish from focally spared areas of irregular fatty liver. Even if areas of focal sparing are irregular in shape, hepatic tumors should be carefully ruled out in patients at high risk for liver tumors.

Adult↗
PubMedDate not supplied

CT and MRI in detection of intrahepatic portosystemic shunts in patients with liver cirrhosis.

OBJECTIVE: Our goal was to determine the prevalence and anatomic location of intrahepatic portosystemic shunts (IPSs) in patients with hepatic cirrhosis as shown by CT and MRI. MATERIALS AND METHODS: We retrospectively reviewed CT and MR scans of 33 cirrhotic patients who had IPSs. In addition, two series of 100 consecutive CT or MR were reviewed to determine the prevalence of IPSs and the percentage of intrahepatic and extrahepatic paraumbilical veins. RESULTS: Intrahepatic portosystemic shunts were divided into three groups according to the intrahepatic course: paraumbilical shunt between the left portal vein and the paraumbilical vein anterior to the liver (n = 29); inferior vena caval shunt between the posterior branch of the right portal vein and the inferior vena cava (n = 2); and miscellaneous (n = 2). Shunts of the paraumbilical type ran through the medial (n = 23), lateral (n = 3), or both medial and lateral (n = 3) segments of the left lobe of the liver. Twenty-five patients had one shunt, and four had more than one. Six cases were also associated with extrahepatic paraumbilical veins. CONCLUSION: Intrahepatic portosystemic shunts, especially the paraumbilical type, were not infrequently visualized in patients with hepatic cirrhosis.

Adult↗
PubMedDate not supplied

Ovarian dysgerminoma: MR and CT appearance.

OBJECTIVE: We determined the MR and CT appearance of ovarian dysgerminoma and correlated our findings with the pathologic features. MATERIALS AND METHODS: CT and MR findings of three patients with ovarian dysgerminoma were retrospectively reviewed and compared with the pathologic findings. RESULTS: The tumors were divided into lobules by septa that were hypointense or isointense on T2-weighted imaging and showed marked enhancement on Gd-diethylene triamine pentaacetic acid enhanced T1-weighted imaging and contrast-enhanced CT. These septa corresponded to fibrovascular bundles at histologic examination. CONCLUSION: CT and MR findings characteristic of fibrovascular septa within solid ovarian masses should raise the possibility of dysgerminomas.

Adolescent↗
PubMedDate not supplied

Circadian blood pressure change after carteolol chloride in younger and older hypertensive patients.

To determine whether there is an age-related difference in circadian blood pressure changes after administration of a beta-adrenergic blocker, 24-hour ambulatory blood pressure was measured before and after administration of long-acting carteolol, a beta-blocker with intrinsic sympathomimetic activity, in 9 younger and 13 older hypertensive patients. Ambulatory blood pressure was measured noninvasively using an ambulatory blood pressure monitor every 30 minutes for 24 hours before and 8 weeks after a once-daily administration of 15 mg of carteolol. Systolic and diastolic blood pressure in the office significantly decreased in both groups after 8 weeks of carteolol treatment. The whole-day systolic and diastolic blood pressures also fell significantly after carteolol treatment in both groups. Carteolol reduced systolic and diastolic blood pressures during the day in both groups. However, no reduction was observed in nighttime systolic blood pressure in either group, although nighttime diastolic blood pressure tended to decrease in the younger group (P = 0.051). The pulse rate during the night significantly increased in both groups, although no change was observed during the day in either group. We conclude that the antihypertensive effect of carteolol on the circadian blood pressure pattern in younger and older hypertensive patients is comparable. Carteolol reduced only daytime blood pressure while hardly affecting the nighttime blood pressure in both groups.

Aged↗