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Biomedical subjects

T Nakamoto

Publications and source records attributed to T Nakamoto.

At least 91 records · Page 5Linked to original sources
PubMed1995

Gravitropic reaction of primary seminal roots of Zea mays L. influenced by temperature and soil water potential.

The growth of the primary seminal root of maize (Zea mays L.) is characterized by an initial negative gravitropic reaction and a later positive one that attains a plagiotropic liminal angle. The effects of temperature and water potential of the surrounding soil on these gravitropic reactions were studied. Temperatures of 32, 25, and 18C and soil water potentials of -5, -38, and -67 kPa were imposed and the direction of growth was measured for every 1 cm length of the root. The initial negative gravitropic reaction extended to a distance of about 10 cm from the grain. Higher temperatures reduced the initial negative gravitropic reaction. Lower soil water potential induced a downward growth at root emergence. A mathematical model, in which it was assumed that the rate of the directional change of root growth was a sum of a time-dependent negative gravitropic reaction and an establishment of the liminal angle, adequately fitted the distance-angle relations. It was suggested that higher temperatures and/or a lower water potential accelerated the diminution of the initial negative gravitropic reaction.

Gravitropism↗
PubMed1995

Effect of dietary caffeine and zinc on the activity of antioxidant enzymes, zinc, and copper concentration of the heart and liver in fast-growing rats.

The purpose of this study was to determine the relationship between concentrations of Zn and Cu and the activities of superoxide dismutase and glutathione peroxidase in the heart and liver of young rat pups whose dams were fed a diet supplemented with caffeine and/or Zn. Four groups of dams with their newborn pups were fed one of the following diets for 22 d: 20% protein basal diet; the basal diet supplemented with caffeine (2 mg/100 body wt); the basal diet supplemented with Zn (300 mg/kg diet); or the basal diet supplemented with caffeine plus Zn. The Cu levels in the livers of the pups were decreased by maternal intake of the caffeine and Zn diet. The maternal intake of the caffeine diet increased Mn-superoxide dismutase (MnSOD) activity and Cu, Zn-superoxide dismutase (Cu,ZnSOD) in the heart of the pups. On the other hand, the activity of Cu,ZnSOD was significantly reduced in the liver of pups whose dams consumed a caffeine, Zn, or caffeine plus Zn diet. Cu,ZnSOD activity in the liver of the pups seems to be correlated with Cu levels in the tissue. Selenium-dependent glutathione peroxidase (GSH-Px) activities in the heart and liver showed no difference among the groups. The effect of dietary caffeine and/or Zn on the activity of antioxidant enzymes in the heart and liver were different in young rats. The activities of these enzymes in the heart were lower than in the liver of 22-d-old rats. Our experiments indicate that the heart has limited defenses against the toxic effects of peroxides when compared to the liver.

Animals↗
PubMed1995

Combined effects of caffeine and malnutrition on the development of the trigeminal nuclear center: autoradiographic and biochemical studies.

Six groups of pregnant dams were each fed a 20%, 12%, and 6% protein diet with and without caffeine (2 mg/100 g b.wt), starting on day 7 of gestation. Dams of each group were injected with two successive daily doses of 3H-thymidine in an overlapping series beginning on day 7 and ending on day 16 of gestation. At day 15 postbirth, brains of the offspring were removed, fixed and embedded. Neurogenesis in the rat trigeminal motor nucleus was examined by radiogram in serial sections. In general, the peak production of the neurons of the motor nucleus of V in the malnourished group of the control was on embryonic (E) days E10 + 11, whereas that of the caffeine group was E11 + 12. In the normally nourished group, peak production in the control was E9 + 10, whereas in the caffeine group it was E11 + 12. Trigeminal areas from the brains of pups of each group, which were kept frozen from our previous studies on suckling behavior (23), were used to analyze DNA, protein and cholesterol levels in the present study. At day 1 caffeine's effects on DNA, protein and cholesterol concentrations of the trigeminal area between the groups were different, depending upon the nutritional status. At day 15, those parameters in the caffeine group were greater although no caffeine was added to the lactating dams' diet. This study again demonstrated that prenatal caffeine intake in combination with protein-energy malnutrition produces permanent effects on the trigeminal nuclear center indicated by autoradiography and changes in biochemical parameters.

Animals↗
PubMed1995

The monoethylglycinexylidide test is more useful for evaluating liver function than indocyanine green test: case of a patient with remarkably decreased indocyanine green half-life.

Lidocaine was used for evaluation of hepatic function in a patient undergoing hepatic resection. Preoperatively, half-life of indocyanine green (ICG) was 33 min after intravenous administration. Plasma concentration of the N-dealkylated metabolite of lidocaine, monoethylglycinexylidide (MEGX), was quantitatively determined to evaluate hepatic function. The patient's rate of formation of MEGX at 15 min after administration of lidocaine was within normal limits, at 56 micrograms/L. These findings suggest that in this patient, hepatic cytochrome P-450IIIA activity was not impaired, but selective impairment of uptake of ICG into hepatocytes or excretion into the bile ducts was present. The rate of formation of MEGX was decreased, and plasma concentration of bilirubin was elevated postsurgically; this could have been the result of decreased cytochrome P-450IIIA activity or decreased hepatic blood flow after hepatic resection. We conclude that the rate of formation of MEGX is a better index of hepatic function than is ICG half-life.

Humans↗
PubMed1995

Pulmonary nodules in patients with a history of radical nephrectomy for renal cell carcinoma.

BACKGROUND: Nine patients with a history of radical nephrectomy for renal cell carcinoma underwent surgical removal of newly detected pulmonary nodules at the Hiroshima University Hospital. Six patients had metastatic lung tumors two patients had bronchogenic primary carcinomas and one had a granulomatous infection. METHODS: To determine if any characteristics can distinguish a new primary carcinoma from metastatic renal cell carcinoma, we reviewed the nine patients described above. The patients with pulmonary metastases and those with new primary lung cancers did not differ in age, sex, history of smoking, clinical stage and pathological findings of the renal primary site, on the location and size of the pulmonary nodules. RESULTS: Only the interval between the nephrectomy and the appearance of the new pulmonary lesion may be a predictive factor. This interval was 48 and 51 months for the patients with new primary lung cancers but varied from 0 to 39 months for the patients with metastatic renal cell carcinoma. A solitary nodule had an equal chance of being metastatic or primary. CONCLUSIONS: These results indicate that a solitary nodule that is detected at a longer interval after radical nephrectomy may be a new primary lung cancer. Once new pulmonary nodules are identified in a patient with a history of radical nephrectomy for renal cell carcinoma, surgical excision is required for a final diagnosis before initiating therapy for metastases.

Adult↗
PubMed1995

Effects of caffeine intake during gestation and lactation on the acid solubility of enamel in weanling rats.

The purpose of this study was to evaluate the effects of dietary caffeine during gestation and lactation on the acid solubility of molar teeth of weanling rats. Nineteen pregnant dams were divided into two groups. The 9 dams in the control group were fed a 20% protein diet supplemented with caffeine (2 mg/100 g BW) throughout the experiment. At birth, 8 pups were randomly assigned to each dam. Pups were killed on day 22. The 1st and 2nd molars were removed from each pup's maxilla and mandible. Four randomly selected molars from each litter were placed in a chamber and bathed with a flow of acid solution and the amount of mineral dissolved from the enamel was determined. The results showed that the amount of dissolved Ca and Mg from enamel surfaces of 1st molars from rats in the caffeine group after exposure to acid was consistently greater than that of the non caffeine group. In the 2nd molars there was no significant difference between caffeine and noncaffeine groups. Scanning electron microscopy revealed an alteration of the enamel surface of the 1st molars of the caffeine group after acid exposure. These results indicate that caffeine intake during gestation and lactation would have a deleterious effect on dental enamel of 1st molars in newborn rats.

Animals↗
PubMed1995

Preliminary results of methotrexate, etoposide and cisplatin in the treatment of urothelial cancer.

Thirty-seven patients with urothelial cancer were given combination chemotherapy with methotrexate, etoposide and cisplatin. Thirty patients were evaluated for response. Response rates were 50% in the primary organ, 50% in the lymph nodes, 0% in lung and bone lesions. Two patients (7%) had a complete response and 12 (40%) had a partial response, for an overall response rate of 47%. The overall response rate rose to 57% in 7 patients treated with escalated doses of methotrexate and cisplatin. The median durations of response were 14 months for complete responders and 16 months for partial responders. Of the 30 evaluable patients, 16 (53%) are alive at a median survival of 30 months. The toxicity of the present regimen was acceptable. The methotrexate-etoposide-cisplatin combination chemotherapy seems to be an effective and safe regimen for urothelial cancer.

Adenocarcinoma↗
PubMed1995

[A case of graft-versus-host disease following red cell concentrate (MAP-CRC) transfusion].

We report a case of transfusion-associated graft-versus-host disease (GVHD). A 79-year-old woman with Hodgkin's disease, respiratory failure and severe anemia who had been treated with two courses of chemotherapy was transfused with red cell concentrate (MAP-CRC) and fresh frozen plasma (FFP) in the ICU. On the 7-9th days after transfusion, she developed a diffuse erythematous rash mainly on the chest, high fever, liver dysfunction and thrombocytopenia. Despite treatment with immunoglobulin products and methylprednisolone, her condition deteriorated rapidly, and she died of multiple organ failure on the 7th day after appearance of rash. Skin biopsy demonstrated typical features of acute GVHD, suggesting that MAP-CRC-associated GVHD had occurred.

Aged↗
PubMed1995

Cisplatin-based neoadjuvant chemotherapy for invasive bladder cancer.

Between February 1988 and March 1993, 24 patients with locally advanced bladder cancer (stages T2-4N0-3M0) were included in this study. Combination chemotherapy consisting of methotrexate, vinblastine, epirubicin (doxorubicin) and cisplatin (M-VAC) was given to the patients in a neoadjuvant setting. The clinical stage was T2N0M0 in eight patients, T3aN0M0 in three, T3bN0M0 in seven, T4N0M0 in five and T4N3M0 in one. After chemotherapy, total cystectomy was performed in 20 patients and partial cystectomy 4. Of 24 patients, one (4%) showed a pathological complete response, and eight (33%) had a pathological partial response, for an overall response rate of 38% (95% confidence limits 20 to 57%). Nine patients who achieved a pathological response to chemotherapy had a significantly higher survival rate than the nonresponders (p <0.01). In the relationship between the clinical stage and the response to chemotherapy, clinical T2 and T3a diseases were more likely to respond to chemotherapy than clinical T3b and T4 diseases, with a response rate of 64% and 15%, respectively. While a positive relationship between the pathological response and survival was observed, adequate follow-up is needed to assess the ability of neoadjuvant chemotherapy to improve the prognosis of patients with locally advanced bladder cancer.

Adult↗
PubMed1994

Effects of chronic caffeine feeding on the activities of oxygen free radical defense enzymes in the growing rat heart and liver.

The purpose of the present study was to determine the relationship between concentration of Zn, Cu and Fe, and the catalase, glutathione peroxidase and superoxide dismutase activities in the heart and liver of newborn rats whose dams were fed a diet supplemented with caffeine. Heart Zn levels of the 22- and 30-day-old rats of the caffeine group showed a decrease, whereas liver Zn levels showed an increase compared to the control. Cu levels in the liver at day 22 in the caffeine group were less than in the control. Cu- and Zn-containing superoxide dismutase activities showed an increase in the hearts of the caffeine group compared to the control. The activity of catalase and glutathione peroxidase showed no difference in the heart and liver between the groups. The present study suggests the possible involvement of superoxide dismutase enzyme in the impairment of heart formation as a result of chronic caffeine intake in the early growing period.

Aging↗
PubMed1994

Combined effects of caffeine and malnutrition during pregnancy on suckling behavior in newborn rats.

Six groups of pregnant dams were fed a 20%, 12%, and 6% protein diet with and without caffeine (2 mg/100 g b.wt.), starting on day 7 of gestation. At day 18 of gestation, randomly selected dams of each group were used to record prenatal fetal behavior. The remaining dams were continuously fed their respective diets until the birth of their pups. Upon delivery, newborn pups from the dams fed a 20%, 12%, or 6% protein diet with caffeine were placed with foster dams that the dietary regimen during gestation was a 20%, 12%, or 6% protein diet, respectively. Dams fed a noncaffeine diet, along with their newborns, were fed their respective diets until day 15. Suckling behavior tests for newborns were conducted on days 2, 8, and 15. On day 15, both nondeprived and deprived newborn rats were studied. Caffeine in combination with a malnourished diet has different effects on general activity in prenatal stages compared to postnatal stages. Our findings support the view that prenatal exposure to caffeine may produce greater effects because: a) caffeine and its metabolites pass freely into the embryo and attain a concentration slightly lower than in the maternal plasma; and b) caffeine may be poorly metabolized during pregnancy, causing an accumulation in the fetal tissues. Prenatal caffeine at the dosage we have used in combination with malnutrition may produce lasting metabolic alterations in the nervous system related to the emergence of suckling behavior and general motor activity.

Animals↗
PubMed1994

Alteration of femoral structure in later life by chronically feeding caffeine during rapid growing period in newborn female rats.

The effects of caffeine intake in early life on bone structure later in life were studied in rats. At day 9 of gestation, dams were divided into 2 groups. Group 1 (control) received a 20% protein diet; group 2 received the 20% protein diet supplemented with caffeine (2 mg/100 g body weight). After birth pups were continuously fed their respective diets until day 93, when the diet of group 2 was replaced with a noncaffeine 20% protein diet. On day 388 animals from both groups were weighed, killed, and femora and mandibles were removed. Calcium, phosphorus, magnesium, zinc, hydroxyproline, and hexosamine concentrations were measured. Radiographs of some femora were taken and paraffin cross sections were made at the midshaft of others. Femora in the caffeine group were wider, periosteal bone area/total bone area was greater, the cross sectional area of femoral bone was smaller, and there were fewer osteocytes/bone area than in controls. Calcium, phosphorus, zinc, and hydroxyproline concentrations in the caffeine group were less in both bones of the caffeine group. These results indicate that if animals are exposed to caffeine during the rapidly growing period, changes occur in femoral bone which are similar to those that occur with aging.

Animals↗
PubMed1994

Metastatic renal cell carcinoma arising in a native kidney of a renal transplant recipient.

We report a case of metastatic renal cell carcinoma arising in the native kidney of a renal transplant recipient. A 39-year-old man, who had undergone living renal transplantation from his mother at age 32, presented with complaints of paraplegia of the leg caused by a pathological fracture of the 3rd lumbar vertebra. The bone tumor was extirpated and pathological examination revealed metastatic adenocarcinoma. Abdominal computerized tomography showed a tumor in the right native kidney. Right nephrectomy and resection of the right 7th rib tumor were performed. Pathological evaluation demonstrated renal cell carcinoma of the right native kidney (pT2bpN0pV0M1, mixed cell type, grade 2). Postoperatively, cyclosporine was discontinued and natural interferon-alpha was given. The remaining bone metastasis had completely resolved with no significant sign of rejection 1 year after surgery.

Adult↗
PubMed1994

A case of testicular teratoma located in the opposite side of the upper abdominal wall.

We report a case of a testicular teratoma located in the opposite side of the upper abdominal wall. A 2-year-old boy presented with a non-palpable right testis and underwent right inguinal exploration for right cryptorchidism. During surgery, the tumor was found in the opposite side of the upper abdominal wall across the midline. Histological investigation of the tumor revealed a mature teratoma occurring in the intra-abdominal testis. No such case has been previously reported.

Child, Preschool↗
PubMed1994

[Surgical treatment of renal cell carcinoma with extension into the vena cava].

Between 1985 and 1992, 9 patients (6 men and 3 women), 50-76 years old (mean age 63.6), underwent radical nephrectomy and removal of the tumor thrombus for the treatment of renal cell carcinoma extending into the vena cava at the Department of Urology, Hiroshima University Hospital. Seven tumors were located in the right kidney and two in the left kidney. Three tumor thrombi extended into the vena cava within 2 cm (level 1 according to the Novick's classification), 2 extended into the infrahepatic vena cava (level 2), 2 extended into the suprahepatic vena cava (level 3), and other 2 extended into the right atrium (level 4). Two patients had distant metastases preoperatively. The tumor thrombi at the level 1 were removed by venacavotomy with a short duration of surgery and a small amount of blood loss, while in those at the level of 2 or 3, both the duration of surgery and the amount of blood loss increased because the mobilization of the liver needed to remove the thrombi. For removing tumor thrombi at the level 4, cardiopulmonary bypass and deep hypothermic circulatory arrest were applied, resulting in longer duration of surgery but less amounts of blood loss than those at the level 2 or 3. Postoperatively, 2 patients had a renal insufficiency and another 2 had a liver dysfunction. One operative death occurred in this series because of pulmonary embolism.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗