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Biomedical subjects

T Morimoto

Publications and source records attributed to T Morimoto.

At least 217 records · Page 12Linked to original sources
PubMed1997

Successful long-term xenoperfusion of the pig liver: continuous administration of prostaglandin E1 and insulin.

For clinical utilization of extracorporeal liver perfusion as an artificial liver assist device, we examined the possibility of long-term xenoperfusion of the pig liver by the continuous administration of prostaglandin E1 (PGE1) and insulin. After a 3-hr perfusion period, pig livers that were xenoperfused with human blood exhibited a drastic decrease in the perfusate volume, a progressive elevation of the hepatic artery pressure, a gradual deterioration of bile production, and a marked increase in the release of creatine kinase-BB component. The continuous administration of PGE1 (25 microg/hr) and insulin (1 U/hr) significantly improved these derangements (P<0.05) and allowed stable perfusion for up to 9 hr. This manipulation also inhibited leukocyte aggregation in the graft, the characteristic perfusate hemolysis, and acceleration of ketogenesis. Histological examination revealed that the interlobular edema and hemorrhage, characteristics of tissue injuries in xenogeneic hyperacute rejection, were markedly alleviated in the PGE1 and insulin-treated group. This study clarifies the finding that the combined administration of PGE1 and insulin is effective for long-term xenogeneic extracorporeal liver perfusion, with the graft viability well maintained.

Alprostadil↗
PubMed1997

Role of submandibular and sublingual saliva in maintenance of taste sensitivity recorded in the chorda tympani of rats.

1. To evaluate the role of saliva in the maintenance of taste sensitivity, the activities in the rat chorda tympani innervating taste buds in the anterior part of the tongue were analysed. The effects of chronic extirpation of the submandibular and sublingual salivary glands were tested and compared with results after chronic oral administration of artificial saliva. 2. Removal of the salivary glands sharply decreased chorda tympani responses to four different taste stimuli by 7 days post-desalivation, while a stable response to cold water was observed by at least 28 days. 3. This selective decrease in taste responses was considerably recovered by 7-day-oral injection of artificial saliva (containing NaHCO3, KCl and/or mucin) or distilled water. However, the injection of the salt-containing artificial saliva induced significantly larger sucrose and smaller NaCl, HCl and quinine responses than did the injection of distilled water. 4. In our salivary manipulations, an alteration in the number of the functional sweet receptors was suggested by the cross-adaptation technique using NaHCO3, whereas sensitivity to the epithelial sodium transport blocker, amiloride, was stable in the NaCl response. 5. Salivary water and electrolytes which may participate in forming the external environment of the taste receptor cells modulated taste sensitivity in the chorda tympani.

Adaptation, Physiological↗
PubMed1997

Hyperthermia enhances spectrin breakdown in transient focal cerebral ischemia.

Calpain-mediated spectrin degradation is triggered by cerebral ischemia and, when persistent, is thought to signal irreversible neuronal injury. Hyperthermia superimposed upon cerebral ischemia may exacerbate the injury process. In this study, we compared the extent of spectrin degradation in the brains of rats subjected to 1 h of transient proximal middle cerebral artery (MCA) clip-occlusion performed under conditions of cranial normothermia (37 degrees C) or mild cranial hyperthermia (39 degrees C). Immunocytochemical localization of spectrin breakdown products was achieved by the use of a rabbit polyclonal antibody which reacted selectively with calpain-generated fragments of brain spectrin. The perfusion times studied were 1, 4 or 24 h. Following normothermic MCA occlusion, spectrin immunoreactivity was present only occasionally and only in scattered cortical neurons immediately upon reperfusion and 1 h later; all normothermic brains showed space immunoreactivity at 4 h of reperfusion; and no immunoreactivity was detected at 24 h. By contrast, following hyperthermic MCA occlusion, moderate-to-intense immunostaining was present in cortical pyramidal neurons even immediately upon reperfusion and persisted at 1 h of reperfusion. At 4 and 24 h, most brains exhibited dense immunoreactivity associated with morphologically shrunken neurons. Following 24 h survival, semi-thick plastic sections revealed intact neuropil and only selective neuronal necrosis in normothermic rats. By contrast, pan-necrosis was evident 24 h after the hyperthermic ischemic insult. These results indicate that mild cranial hyperthermia superimposed upon transient focal ischemia markedly enhances calpain activation and spectrin degradation; this process appears to be an important mechanism by which hyperthermia exacerbates ischemic injury.

Animals↗
PubMed1997

Tenosynovial nodulosis in a patient infected with human T cell lymphotropic virus I.

We describe a 45-year-old man who presented with multiple nodules along the tendons of the scapular region, the elbows, wrists, forearms, thighs, and ankles. The patient was a carrier of human T cell lymphotropic virus I (HTLV-I), which was probably transmitted from his mother; his mother also had polyarthritis. Histopathologically, the nodules consisted of numerous, small, fibrinoid masses. The synovium adjacent to the tendon sheath was hyperplastic, with fibrinoid necrosis mimicking rheumatoid synovium. However, synovitis was not present inside the adjacent joint. HTLV-I proviral DNA was detected in the cells of the nodule, in tenosynovial cells, and in peripheral blood lymphocytes, but not in skin fibroblasts. In situ reverse transcription assay showed a high quantity of tax/rex messenger RNA in the proliferating lining cells. Based on these features, we classified this case as an atypical manifestation of HTLV-I-associated arthropathy associated with fibrinoid nodules resulting from chronic tenosynovitis.

Carrier State↗
PubMed1997

Right ventricular myxoma: report of a case.

We herein report a 36-year-old man who underwent surgical resection for myxoma. Preoperative two-dimensional echocardiography demonstrated a mass in the right ventricle. Intraoperatively, the tumor was found to derive from an anterior papillary muscle of the tricuspid valve. The tumor was successfully excised and the tricuspid valve was repaired with chordoplasty and annuloplasty. A histopathological examination revealed myxoma and a 2-year follow-up has shown no evidence of recurrence or tricuspid valve regurgitation.

Adult↗
PubMed1997

A new hydroxyl radical scavenger "EPC" on cadaver heart transplantation in a canine model.

This study was performed to determine if an "arrested" heart, resuscitated with cardiopulmonary bypass (CPB) after the cessation of beating, can be successfully transplanted, and whether a hydroxyl radical scavenger EPC can reduce ischemic and reperfusion injury during resuscitation of the arrested heart and following orthotopic heart transplantation. A total of 16 pairs of canines were divided into a control group of eight pairs and an EPC-treated group of eight pairs. Cardiac arrest of the donor heart was induced by the discontinuation of respiratory support after the induction of brain death. The cadaver heart was then resuscitated and core-cooled to myocardial temperature of 15 degrees C using CPB. The donor heart was harvested using cold cardioplegia and orthotopically transplanted. All of the transplanted hearts in the EPC group were weaned from CPB without any inotropic support after 60 min of bypass support, whereas all the animals in the control group required 5 micrograms/kg/min dopamine (P = 0.001). Moreover, cardiac function (Emax) 1 h after orthotopic heart transplantation was better preserved in the EPC group than in the control group, at 110 +/- 36% vs. 70 +/- 21% of the post brain death values (P = 0.02) These findings demonstrate that EPC reduces posttransplant reperfusion injury, and thus it may prove to be a valuable adjunct in this challenging model.

Animals↗
PubMed1997

Fast in vivo measurements of local tissue impedances using needle electrodes.

The objective of the research is to show an in vivo, fast method of measurement of local tissue bio-impedance in the beta dispersion region (0-200 kHz). A needle electrode is used for the purpose. The performances with respect to circuits, electrodes, measurement area and electrical representations are evaluated. A measurement example is shown, and the electrical representations are discussed and compared using it. The method discussed, although invasive, is considered to be useful for local tissue diagnoses concerning structures and physiological functions.

Body Composition↗
PubMed1997

Clinical study of epilepsy with severe febrile seizures and seizures induced by hot water bath.

We followed five cases with severe febrile seizures (FS) with early onset and seizures induced by hot water bath, indicating severe myoclonic epilepsy in infancy (SME) or the peripheral form of SME. These cases, however, had far better clinical courses than that of SME or the peripheral form of SME. These cases were characterized by: (a) severe FS with early onset and seizures induced by hot water bath; (b) a lack of myoclonic seizures; (c) no psychomotor deterioration; (d) no underlying disorders or signs of brain insult on neurologic and laboratory examination; (e) relatively successful seizure control; (f) none of the severe EEG abnormalities seen in SME and the peripheral form of SME; and (g) a positive family history of convulsive disorders.

Adolescent↗
PubMed1997

Metastatic gastric lymph node rate is a significant prognostic factor for resectable stage IV stomach cancer.

BACKGROUND: Stage IV gastric carcinoma is rarely curatively resected and almost invariably carries a poor prognosis. Several clinicopathologic factors are involved, but lymphatic spread of the cancer may significantly affect survival. STUDY DESIGN: A retrospective study was designed to evaluate whether the nodal metastatic rate (number of lymph node metastases/number of resected lymph nodes) is a parameter of lymphatic spread and could provide a significant prognostic factor. Several prognostic factors were assessed by multivariate analysis in 153 stage IV gastric carcinoma patients with histopathologic data on nodal metastasis. RESULTS: A significant difference in survival was observed in the stage IV cancer patients with total nodal or gastric nodal metastatic rates < 50% versus those with rates > 50%. Multivariate analysis revealed that a total nodal or gastric nodal metastatic rate > 50% was a highly significant prognostic factor. The gastric nodal metastatic rate can be used in patients who do not undergo an extended lymphadenectomy. CONCLUSIONS: Lymphatic spread of gastric carcinoma expressed in terms of the total nodal or gastric nodal metastatic rate is a significant prognostic factor. The latter can be calculated without pathologic data derived from extended lymphadenectomy, and so it is universally applicable.

Humans↗
PubMed1997

Fatal interstitial pulmonary disease in a patient with dyskeratosis congenita after allogeneic bone marrow transplantation.

Chronic restrictive lung disease in a 9-year-old boy with dyskeratosis congenita (DC) 7 years after allogeneic bone marrow transplantation (BMT) is described. When he was 1 year and 10 months old, severe aplastic anemia developed. He received a marrow transplant from his HLA serologically identical, but HLA-DP mismatched brother. He developed grade II acute graft-versus-host disease (GVHD) and thereafter chronic GVHD of progressive type, and was treated with both prednisolone and azathioprine resulting in clinical improvement. Thereafter he complained of dyspnea, and bilateral noncircumscribed interstitial shadows on chest CT scan were present. His pulmonary function showed restrictive changes. Prednisolone was not effective and he died of respiratory failure. Post-mortem examination confirmed interstitial fibrosis, lymphocytic infiltration of the bronchioles and alveoli with luminal fibrosis. There was no evidence of chronic GVHD in the skin and the liver. These findings raise the possibility that this pulmonary complication was associated with DC itself.

Anemia, Aplastic↗
PubMed1997

Modulation of circadian expression of D-site binding protein by the schedule of parenteral nutrition in rat liver.

The aim of this study was to investigate the changes in the circadian rhythm of the expression of liver-specific genes caused by different schedules of parenteral nutrition (PN). Rats received PN continuously throughout the day or intermittently during the night or day for 7 days. They were examined for gene expression of D-site binding protein (DBP), albumin, and cytochrome P450 cholesterol 7alpha-hydroxylase (CYP7) in the liver. The nocturnal PN group showed circadian expression of DBP messenger RNA (mRNA) and protein with a peak at 10 PM, in the same manner as the control rats receiving normal chow feeding. However, the diurnal PN group showed inverted expression of DBP mRNA and protein with a peak at 10 AM. CYP7 mRNA levels exhibited good synchronization with the levels of DBP mRNA in all groups, whereas albumin mRNA levels did not show such synchronization. Gel mobility-shift assay disclosed that the binding activity of the nuclear extracts to the CYP7 gene promoter was changed by the PN schedule in accordance with the expression of CYP7 mRNA. The PN schedule modulates the circadian rhythm of DBP expression and may have an effect on hepatic bile acid formation through transcriptional regulation of the CYP7 gene.

Albumins↗
PubMed1997

Effects of cyclic and continuous parenteral nutrition on albumin gene transcription in rat liver.

To evaluate schedule-dependent effects of parenteral nutrition on albumin gene expression and regulation, mRNA levels for albumin and its promoter-binding nuclear factors in the liver were measured in rats receiving cyclic or continuous parenteral nutrition. Rats were divided into three groups: the control group (n = 5) received a nonpurified diet, the continuous parenteral nutrition group (n = 5) received a continuous infusion of a defined parenteral nutrition formula, and the cyclic parenteral nutrition group (n = 5) received a cyclic (between 2000 and 0800) infusion of the same formula. After 7 d, rats were killed to obtain serum and liver. The serum albumin concentrations were 44 +/- 3 g/L in the controls, 31 +/- 2 g/L in the continuous parenteral nutrition group, and 33 +/- 3 g/L in the cyclic parenteral nutrition group. The mRNA for albumin and D site binding protein (DBP) was more abundant and mRNA for CCAAT/enhancer binding protein beta (C/EBP beta) was less abundant in the cyclic parenteral nutrition group than in the continuous parenteral nutrition group. Gel-shift assay for D site and gel-shift Western blotting of DBP carried out using another three rats in each group revealed an increase of DBP in rats receiving cyclic parenteral nutrition compared with continuous parenteral nutrition. In conclusion, although parenteral nutrition decreases serum albumin concentrations, cyclic parenteral nutrition maintains transcription of the albumin gene to a greater extent than does continuous parenteral nutrition. Cyclic parenteral nutrition, in contrast with continuous parenteral nutrition, sustains the mRNA and concentrations of DBP.

Albumins↗
PubMed1997

Gene expression of albumin and liver-specific nuclear transcription factors in liver of protein-deprived rats.

Protein-energy malnutrition causes hypoalbuminemia. Recent work has suggested that this may be partly due to decreased transcription of the albumin gene. This study examined the role of cis-acting and transacting elements of the albumin gene during protein deprivation. Male 7-wk-old Donryu rats were fed a protein-free diet (0% casein diet) for 10 d or given restricted (pair-fed control) or free access (freely fed control) to a 25% casein diet. Serum albumin concentrations were significantly lower in the protein-deprived rats (29 +/- 1 g/L) than in the pair-fed controls (42 +/- 3 g/L) or the freely fed controls (45 +/- 3 g/L). The albumin mRNA level was also significantly lower in livers of protein-deprived rats (36% of pair-fed control). However, gel mobility shift analysis using liver nuclear extracts did not show any significant difference between the protein-deprived rats and the pair-fed controls in the binding activity to the B and D sites of the albumin promoter. Furthermore, gel mobility shift-Western blot analysis showed no significant difference between the two groups in the protein levels of nuclear transcription factors binding to the D sites. The amounts of mRNA of hepatocyte nuclear factor-1 binding to the B site were not significantly different between these two groups. These results suggest that the proximal promoter region may not play a major role in the down-regulation of the albumin gene during protein deprivation.

Analysis of Variance↗
PubMed1997

Involvement of interleukin-6 in activation of lysosomal cathepsin and atrophy of muscle fibers induced by intramuscular injection of turpentine oil in mice.

Serum IL-6 level increased after the injection of turpentine oil into the right gastrocnemius muscle in mice. The mRNA level of IL-6 was highest in the injected muscle at 12 h after injection, but was not identified in the opposite muscle. The activities of cathepsins B and B+L started to elevate after 12 h in the injected muscle and markedly increased after day 3. Likewise, the mRNA levels of cathepsins B and L markedly increased from day 1 to day 5 in the injected muscle. However, a very mild increase was also observed in the opposite muscle. Immunohistochemical staining of cathepsins B and L exhibited positive reactions as fine granules in myofibers at 12 h and strong positive reactions in the infiltrating macrophages at 3 days. Atrophy of myofibers type 1 and 2 was evident in a time-dependent manner in the injected muscle. Treatment with rat anti-mouse IL-6 receptor monoclonal antibody inhibited the increase in cathepsin activities in the injected muscle. We conclude that IL-6 produced in the inflamed muscle is involved in the process of muscle degeneration, especially through the activation of lysosomal cathepsins.

Animals↗
PubMed1997

A new macroscopic classification predicts prognosis for patient with liver metastases from colorectal cancer.

OBJECTIVE: The authors defined a new macroscopic classification of liver metastases from colorectal cancer. SUMMARY BACKGROUND DATA: There were different prognostic results after the same operative procedure for liver metastases with similar background factors. METHODS: Eighty-one resected liver metastases were classified into simple nodular (SN) or confluent nodular (CN) types according to the characteristics of the cut surface of the tumor. RESULTS: The 5-year survival rates after hepatectomy were 41.7% for the SN lesions (n = 39) and 23.1% for the CN lesions (n = 42). The difference between the survival curves was statistically significant (p = 0.0307). Multivariate analysis using Cox's proportional hazards model revealed that the macroscopic type (p = 0.023), the tumor diameter (p = 0.0001), and the presence of lymph node metastases (p = 0.0016) were statistically significant independent prognostic factors. CONCLUSION: The new macroscopic classification may be valuable as a prognostic factor reflecting the biologic behavior of liver metastases.

Colorectal Neoplasms↗
PubMed1997

Relationship between aerobic power, blood volume, and thermoregulatory responses to exercise-heat stress.

To clarify the relationship between aerobic power (VO2max), blood volume (BV), and thermoregulatory responses to exercise-heat stress, we analyzed the cross-sectional relationship between the resting BV, plasma volume (PV), erythrocyte volume (EV), VO2max, forearm blood flow (FBF), and sweating responses during exercise in a hot environment (31 degrees C, 50% relative humidity). Twelve college-aged male subjects with a mean maximal oxygen uptake of 48 (range 42-59) mL.kg-1.min-1, a mean PV of 54 (range 42-72) mL.kg-1, a mean EV of 31 (range 23-43) mL.kg-1, and a mean BV of 85 (range 67-115) mL.kg-1 (measured by the Evans Blue dye dilution method) performed three sessions of 20-min cycle exercise at two levels of intensity (40% and 60% VO2max). The BV, PV and EV correlated positively with peak FBF (r = 0.596-0.711, P < 0.05), the increase of FBF in response to a unit rise in esophageal temperature (Tes; peak delta FBF/peak delta Tes) (r = 0.592-0.656, P < 0.05) and with total sweat loss (TSL) (r = 0.599-0.634, P < 0.05) during the exercise. The VO2max correlated with TSL during exercise at 40% VO2max (r = 0.578, P < 0.05), but not with peak FBF and peak delta FBF/peak delta Tes. The VO2max per lean body mass also showed a significant positive correlation with BV (r = 0.769, P < 0.01), PV (r = 0.706, P < 0.05), and with EV (r = 0.841, P < 0.001). The peak delta FBF/peak delta Tes was correlated positively with peak FBF (r = 0.597-0.830, P < 0.05-0.01) and negatively with peak Tes (r = 0.641-0.769, P < 0.05-0.01) during the exercise at the two levels. However, the chest sweat rate (CSR), TSL, and the increase of CSR in response to a unit rise in Tes (peak delta CSR/peak delta Tes) showed no correlation with peak Tes during the exercise at the two levels. These findings suggest that 1) heat dissipation responses during exercise were related more to blood volume than aerobic power and 2) skin blood flow was related more to body temperature than sweating responses during exercise under mild heat stress.

Adolescent↗
PubMed1997

Evaluating the effect of superficial temporal artery to middle cerebral artery bypass on pure motor function using motor activation single photon emission computed tomography.

OBJECTIVE: We evaluated and analyzed the effect of superficial temporal artery to middle cerebral artery bypass for internal carotid artery occlusion on pure motor function using motor activation single photon emission computed tomography. METHODS: Motor activation single photon emission computed tomographic (SPECT) images were obtained for nine patients who had undergone superficial temporal artery to middle cerebral artery anastomosis for symptomatic internal carotid artery occlusion. All motor activation SPECT images using the finger opposition task on the affected side were obtained before bypass surgery and at 1 week, 1 month, and 3 months after bypass surgery. The results of motor activation single photon emission computed tomography were expressed as negative or positive. RESULTS: Before bypass surgery, the resting SPECT images revealed reduction of cerebral blood flow (CBF) on the affected side in all nine patients. The results of motor activation single photon emission computed tomography in three patients were positive. One week after bypass surgery, the results of the resting and motor activation CBF studies did not demonstrate any marked changes. One month after bypass surgery, the resting CBF increased in four patients. The results obtained for two of the patients revealed preoperative positive motor activation. The results of motor activation single photon emission computed tomography obtained for five patients were positive. Three months after bypass surgery, eight patients experienced improvement in the resting CBF, and the results of motor activation single photon emission computed tomography obtained for seven patients were positive. Among these, the results of preoperative motor activation single photon emission tomography obtained for four patients were negative. CONCLUSION: Superficial temporal artery to middle cerebral artery bypass is useful not only for resting CBF but also for pure motor function based on motor activation SPECT images. From the preoperative motor activation study, it was concluded that patients with preoperative positive motor activation could attain the effect of bypass earlier than patients with preoperative negative motor activation.

Aged↗