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Biomedical subjects

T Nagashima

Publications and source records attributed to T Nagashima.

At least 289 records · Page 16Linked to original sources
PubMed1984

[Nuclear magnetic resonance study of the immature rat brain].

Using rat brains, the maturational change on the water contents and on the proton NMR signals were studied in this laboratory. Water contents, the proton longitudinal relaxation time (T1) and the transverse relaxation time (T2) were measured on the samples from gray and white matters, separately. A constant decrease of these parameter values was observed in relation to the development of the brain. Water content of 1 week-old rat was 88.393 +/- 1.19% in the gray matter (G) and 88.63 +/- 1.96% in the white matter (W). These values decreased gradually and reached adult rat level when the animals became 5 weeks old: 81.47 +/- 1.67% in G and 79.45 +/- 2.39% in W. No marked change on the brain water content was observed thereafter, T1 values of immature (one week-old) rat brain were 1.755 +/- 0.088 sec in G, and 1.832 +/- 0.154 sec in W, while T1 values of the adult rat brain were 1.327 +/- 0.043 sec in G, and 1.297 +/- 0.039 sec in W, respectively. A marked difference was observed on the values of T1 between the immature and the adult rats. T2 value of the 1 week-old rat brain was 101.05 +/- 10.20 msec in G, and 102.75 +/- 8.10 msec in W, respectively. T2 of the mature rat brain was 56.90 +/- 2.61 msec in G, and 54.52 +/- 2.35 msec in W, respectively. A statistically significant correlation was proved between the water content and the proton relaxation time (either T1 and T2).(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1984

[The role of radiotherapy in the management of cancer of digestive organs: the liver, bile tract and pancreas].

Until February 1984, 75 patients have undergone radiotherapy using the following two methods: 1. During surgery, electron 3000 rads were given. 2. For external irradiation, X-ray or fast neutron was given with a TDF (time dose and fractionation factor) of 80-110. Hepatocellular carcinoma: There were 14 patients including 6 preoperative irradiation and 8 unresectable cases. Improvements were obtained image diagnostically in 9 of 13 patients. Serum AFP level decreased in 6 of 8 patients. And the resected specimens revealed degeneration or necrosis of the cancer tissue. Radiotherapy can given beneficial effect to the patients with tumor emboli within the portal vein, or even disappearance of the tumor emboli sometimes could be seen. Bile duct carcinoma: There were 30 patients including 12 with intraoperative irradiation. 2 irradiated during surgery and external irradiation, and 16 with external irradiation. More than 1-year survivals observed in 6 of 18 unresectable cases. The longest survival of non-curative operation was 6.5 years with treatment. Pancreas carcinoma: There were 31 patients including 29 unresectable and 2 resectable cases. Prolongation of survival time in unresectable patients was not obtained with an interval of 5 months at 50% survival rate. But some clinical complaints were relieved. We concluded that radiotherapy is useful to improve surgical curability by decreasing the cancer cell viability, to give a wider surgical indication if portal tumor emboli can be eliminated, to prevent early tumor recurrence, and to give some beneficial effects to unresectable or recurrent patients.

Adult↗
PubMed1984

[The role of endoscopic lithotomy in the treatment of intrahepatic stones].

Although hepatolithiasis is a benign disease, its treatment is still the most difficult one in medical field. Before 1977, we had tried bilioenterostomy at the porta hepatis to expect spontaneous dislodgement of stones. However their results were very poor because of frequent occurrence of cholangitis which leads to hepatic failure or death in 8 of 15 patients. From 1977 to 1981, 35 patients had undergone postoperative cholangioscopy (POC). Complete stone removal was obtained in 24 patients. There were 13 difficult local problems in the remaining 11 patients including 6 being too narrow to permit the passage of the fiberscope, 3 having stones incarcerated, 3 having abnormal distribution of biliary tract and one being a missed stone. From 1981, we have carried out percutaneous transhepatic cholangioscopic lithotomy (PTCL) for the treatment of intrahepatic stones in 16 patients. Because abnormal distribution of biliary tract can be easily detected by PTC and incarcerated stones can be made into small pieces before removal following LASER application. We had succeeded in complete stone removal in 12 patients. 2 patients needed biliary reconstruction or liver resection after PTCL. We concluded that for treatment of the disease of intrahepatic stone PTCL should be considered as the first choice before surgery in order to avoid unnecessary hepatic resection or biliary reconstruction.

Adult↗
PubMed1983

Chronic recurrent demyelinating encephalomyelitis associated with hemophagocytic lymphohistiocytosis.

A man aged 31 with remittent fever, leukopenia, polyuria, and splenomegaly in addition to chronic and recurrent episodes of neurologic abnormalities was examined pathologically. A chronic type of perivenous encephalomyelitis was found in the CNS, and chronic inflammatory lesions were noticed in the infundibulo-hypophyseal system and also in the peripheral nerves. Moreover, hemophagocytic lymphohistiocytosis predominated in the reticuloendothelial system. This seemed to be the first adult case of demyelinating disease with hemophagocytic lymphohistiocytosis.

Adult↗
PubMed1983

Ideogram writing in a disconnection syndrome.

A case of disconnection-type agraphia coupled with alexia was reported. The patient showed several asymmetrical manual capacities between the two hands, i.e., dissociated difficulty of Kanji (ideogram) writing between the two hands, left unilateral difficulty of Kana (phonogram) writing, right unilateral dyscopia of letters as well as geometrical figures, and right unilateral difficulty in drawing without a model. Anatomically, lesions involved most of the corpus callosum in its posterior portion including the splenium and the left medial occipital lobe. From these data, a possible linguistic capacity of the right hemisphere was suggested.

Adolescent↗
PubMed1983

[Effects of phenobarbital on the metabolism of ACNU in vivo].

The nitrosourea compounds are often used in the treatment of patients with malignant brain tumors in combination with anticonvulsants, such as phenobarbital (PB). Since PB can induce hepatic microsomal enzyme--P 450 and degrade nitrosoureas in vivo, the effect of PB on tumoricidal activity in relation to toxicity of 3-[(4-amino-2-methyl-5-pyrimidinyl)-methyl]-1-(2-chloroethyl)-1-nitrosourea (ACNU) was studied using a rat brain tumor model. To determine toxicity, CD-Fisher rats were treated for 4 days with 19 and 38 mg/kg/day of PB (i.m), 0.4 and 0.7 g/kg/day of sodium valproate--SV (p.o), or 3 days with 50 mg/kg of phenytoin (i.v) prior to an administration of 47 mg/kg of ACNU (i.p). The mortality rate by the toxicity within 14 days after administration of ACNU was calculated in each group. The toxicity of ACNU was markedly reduced in PB pretreated rats compared with those without pretreatment or treated with SV or phenytoin. The tumoricidal activity of ACNU was evaluated in CD-Fisher rats with RG 12 brain tumors. Rats received 20 mg/kg ACNU after pretreatment with 19 mg/kg/day of PB (i.m) or 0.2 g/kg/day of SV (p.o) for 4 days. The mean survival days and the percentage increase in life span (%ILS) were compared in each group. Pretreatment with PB significantly reduced the tumoricidal activity of ACNU as compared with control without pretreatment (p less than 0.001) or pretreatment with SV (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

[Histological studies of the effect of intra-operative irradiation on osteosarcoma].

At the Department of Orthopaedic Surgery of Kyoto University Hospital, intra-operative radiotherapy by the high dose electron irradiation has so far been used in treating patients with osteosarcoma. The dose distribution was calculated by CT-number so that the focus was subject to at least 80% of the irradiation doses and the surgically opened lesion was irradiated with 5,000 rad of 12-26 MeV electron beams. In order to accurately assess its therapeutic effect, histological studies were conducted on 9 patients who underwent en bloc resection or amputation following irradiation treatment for osteosarcoma. Method The excised specimen was sagittally cut in half and was fixed in 10% neutral buffered formalin. The specimen was cut into 5 mm thick sections corresponding to CT cross sections. At the border region between irradiated and non-irradiated fields, specimens were prepared using sagittal sections to compare the histological findings of both fields. After all specimens were carefully macroscopically examined and then photographed with soft-X-ray film, some of them were prepared as non- delimed specimens in polyester resin and were observed by contact microradiography and fluorescent microscopy. The remaining specimens after deliming in Plank - Rychlo solution were sliced to 4-8 micron thick for study as large specimen stained with hematoxylin and eosin. Four patients had been administered tetracycline 3 days preoperatively. Results Histologically the changes of the specimens were evaluated using the Oohoshi and Shimosato 's criteria for the histological effects of irradiation. In two of the 9 patients, who had received unidirectional irradiation, the survival of Grade 2a-2b tumor tissue was observed in the superficial layers both inside and outside the periosteum. Six patients who were irradiated from both sides or three directions, showed complete necrosis in extremely small areas of Grade 2b-3 change of tumor cells. Only one of these 9 patients had a local recurrence after the irradiation. Marked fluorescence was observed in the recurrent tissue by tetracycline labeling, but no fluorescence was observed in any of the other cases in the tumorous tissues which had fallen within the range of irradiation. These findings strongly suggest that intra-operative irradiation is extremely effective in controlling local osteosarcoma lesion in the extremities.

Adolescent↗
PubMed1981

Cortical deafness in multiple sclerosis.

Cortical deafness in a patient with multiple sclerosis is reported. Complete recovery from total deafness was seen following stages of auditory agnosia and pure word deafness. The otological and neurophysiological studies suggested lesions in subcortical white matter. This report stresses the rarity of the condition, its subcortical origin and good prognosis.

Adult↗