Biomedical subjects

T Morimoto

Publications and source records attributed to T Morimoto.

At least 541 records · Page 30Linked to original sources

PubMed1990

Nuclear and cytoplasmic localization of different basic fibroblast growth factor species.

The subcellular distribution of basic fibroblastic growth factor (bFGF) was analyzed by subcellular fractionation and immunofluorescence to gain insight into potential mechanisms for its release from cells. Subcellular fractionation of either SK-Hep-1 cells or NIH 3T3 cells transfected with a bFGF cDNA revealed that the 18 kd form of bFGF was found primarily in the cytosolic fraction, whereas the 22 and 24 kd forms of bFGF were found preferentially in ribosomal and nuclear fractions. Analysis of bFGF distribution by immunofluorescence using an antibody that recognized all forms of bFGF indicated both cytoplasmic and nuclear localization but failed to reveal any growth factor in structures representing secretory vesicles. Therefore, bFGF has a distribution inconsistent with that of a secretory protein.

Animals↗

PubMed1990

Cancer of the male breast.

The purpose of this study was to investigate the biological behavior of male breast cancer. We evaluated 11 cases of male breast cancer with respect to tumor growth, extent of disease, hormone receptor status, and histological grade of the malignancy, in comparison with 241 cases of female breast cancer. The duration of symptoms was 8.6 +/- 9.1 months in males and 8.5 +/- 18.6 months in females. The incidences of stages I, II, and III were 46%, 27%, and 27%, respectively, in male breast cancer, and 38%, 49%, and 13% in female breast cancer. Metastasis to the lymph node was negative in 60% of the male patients and 54% of the female patients. All cases of male breast cancer were histologically grade I according to Bloom's classification; the histological grades were as follows for the female breast cancer cases: grade I in 99 patients, grade II in 87, and grade III in 55. The rates of hormone receptor positively were 89% for ER and 86% for PgR in male breast cancer, and 64% for ER and 44% for PgR in female breast cancer. Therefore, there was no significant difference in the growth of male breast cancer and female breast cancer, but in male breast cancer the rate of hormone receptor positivity was high, endocrine therapy was effective, and the histological grade was low. Accordingly, the result following appropriate treatment of male breast cancer should be at least comparable to the results with female breast cancer.

Aged↗

PubMed1990

Biological significance of enhanced mitochondrial ketogenesis during the early stages after 70% hepatectomy in rats.

Ketogenic capacity of mitochondria from the remnant liver of 70% hepatectomized rats was studied in relation to mitochondrial phosphorylative activity. Ketogenic capacity increased to a maximum of 6.04 +/- 0.39 from 3.84 +/- 0.13 of control, with an enhancement of mitochondrial phosphorylative activity 6 hr after hepatectomy, and then decreased to normal levels within 24 hr. Adenylate energy charge, (ATP + 1/2ADP)/(ATP + ADP + AMP), of the remnant liver decreased to 0.825 +/- 0.006 as compared to 0.849 +/- 0.002 of control 6 hr after operation. At 12 hr, total ketone body concentrations of the arterial blood increased concomitant with a fall in ketone body ratio (acetoacetate/3-hydroxybutyrate) which reflects the decreased liver mitochondrial redox (NAD+/NADH) state. These findings suggest that an enhancement of mitochondrial fatty acid oxidation and ketogenesis occurs concomitant with an enhancement of mitochondrial phosphorylative activity in the remnant liver in response to a decreased energy charge after 70% hepatectomy.

Animals↗

PubMed1990

Hyperthermia-induced seizures with a servo system: neurophysiological roles of age, temperature elevation rate and regional GABA content in the rat.

A servo system including a microwave generator was applied to raise a rat's body temperature at a pre-set rate. Using this system the effects of age and the temperature elevation rate upon febrile seizures in rats were studied. The relationship between the brain GABA content and hyperthermia was also studied. From the results of the present study, the seizure occurrence rate was found to be highest at the age of 20 days, brain damage was speculated to be severe after hyperthermia-induced seizures with a slow temperature rise, and the regional GABA concentration in subcortical structures was found to increase during hyperthermia. These data indicate that a servo system with a microwave generator is useful for experimental febrile convulsions, and that GABA neurotransmission in subcortical structures might contribute to feed-back regulation against seizures during hyperthermia.

Aging↗

PubMed1990

Cerebral transmural angiitis and ruptured cerebral aneurysms in patients with systemic lupus erythematosus.

Two cases of cerebral transmural angiitis and ruptured aneurysm in patients with established systemic lupus erythematosus are presented. A 22-year-old woman with a 4-year history of systemic lupus erythematosus was found to have a ruptured cerebral aneurysm at the trifurcation of the middle cerebral artery. She died 10 days after admission because of the brain swelling. Necropsy showed remarkable brain edema and focal transmural angiitis at the site of the ruptured aneurysm. Another 29-year-old woman with a 3-year history of systemic lupus erythematosus had an acute subdural hematoma resulting from a ruptured aneurysm of the right anterior cerebral artery. She was surgically treated. The ruptured aneurysm was resected and examined histologically. The transmural angiitis was demonstrated. This report describes two radiographically and pathologically confirmed cases of central nervous system lupus producing focal angiitis of a cerebral artery with secondary aneurysm formation.

Adult↗

PubMed1990

The circadian rhythm of typical absence seizures--the frequency and duration of paroxysmal discharges.

Twelve patients with typical absence seizures, aged five years two months to 10 years, were examined to clarify the circadian rhythm of 3 c/s spike-and-wave paroxysms (s-w paroxysms), by means of video-electroencephalography with telemetry. S-w paroxysms combined with clinical symptoms and continuing for more than four seconds were fewer during the afternoon than the morning and, moreover, during sleep. The correlation ratio between the frequency and duration of s-w paroxysms was r = -0.74, which was statistically significant (p less than 0.02). The duration of s-w paroxysms evoked by hyperventilation or photic stimulation did not differ from that of spontaneous s-w paroxysms. The s-w paroxysms were shorter and deformed in sleep. Therefore, the observation of typical absence seizures during the morning should be regarded as important. In patients with modified s-w paroxysms during sleep, it is important that electroencephalographic recording with stimulation, such as hyperventilation, is performed sufficiently.

Brain↗

PubMed1990

Anchorage of secretion-competent dense granules on the plasma membrane of bovine platelets in the absence of secretory stimulation.

The ultrastructural changes in electropermeabilized bovine platelets that accompany the Ca2(+)-induced secretion of serotonin were investigated in ultra-thin sections of chemically fixed cells. Such preparations permitted us to study both the localization of and the structures associated with serotonin-containing dense granules. Localization of dense granules within cells was examined by measuring the shortest distances between the granular membranes and the plasma membrane. About 40% of total granules were located close to the plasma membrane at an average distance of 10.8 +/- 1.6 nm. 71% of the total number of granules were localized at a similar average distance of 12.5 +/- 2.7 nm in intact platelets. The percentage of granules apposed to the plasma membrane corresponded closely to the percentage of total serotonin that was maximally secreted after stimulation of the permeabilized (38 +/- 4.9%) and the intact platelets (72 +/- 3.6%). Furthermore, the percentage of granules anchored to the membrane, but not of those in other regions of permeabilized cells, decreased markedly when cells were stimulated for 30 s by extracellularly added Ca2+. The decrease in the numbers of granules in the vicinity of the plasma membrane corresponded to approximately 22% of the total number of dense granules that were used for measurements of the distances between the two membranes and corresponded roughly to the overall decrease (15%) in the average number of the granules per cell. Most dense granules were found to be associated with meshwork structures of microfilaments. Upon secretory stimulation, nonfilamentous, amorphous structures found between the plasma membrane and the apposed granules formed a bridge-like structure that connected both membranes without any obvious accompanying changes in the microfilament structures. These results suggest that the dense granules that are susceptible to secretory stimulation are anchored to the plasma membrane before stimulation, and that the formation of the bridge-like structure may participate in the Ca2(+)-regulated exocytosis.

Animals↗

PubMed1990

Repression of serotonin secretion by an endogenous Ca2(+)-activated protease in electropermeabilized bovine platelets.

Micromolar levels of free calcium ions added to the extracellular medium elicit secretion of serotonin from electropermeabilized bovine platelets in the presence of millimolar levels of Mg-ATP. Such Ca2(+)-dependent secretion of serotonin was almost completely impaired when the permeabilized platelets were preincubated for 1 min at 35 degrees C in 100 microM Ca2+ without Mg-ATP. The half-maximal effect was observed with about 45 microM Ca2+ in the preincubation medium. Inhibitors of serine-thiol protease, such as leupeptin and antipain, suppressed the impairment of the secretion of serotonin by the preincubation with Ca2+. Electron microscopic observation revealed that disorganization of the cytoskeletal structures, in particular of the membrane undercoat and the network of microfilaments, accompanied the impairment of secretion of serotonin. Microfilaments were also found to be dissociated from dense granules that contained serotonin. These morphological changes were also suppressed when antipain was included in the Ca2(+)-preincubation medium. Coincident with these morphological changes, the following biochemical changes were observed in 100 microM Ca2+ but not in the presence of Ca2+ and antipain. The amount of Triton-insoluble cytoskeleton and the acto-myosin content of the dense-granule fraction were markedly decreased. The decrease in Triton-insoluble cytoskeletons was quantitatively correlated with the degree of impairment of secretion of serotonin. Immunoblot analysis of EGTA extracts of the cells showed that the 240-kDa spectrin in platelets was degraded to a 235-kDa fragment, and a 260-kDa actin-binding protein (ABP) in platelets was partially degraded to 190- and 110-kDa components.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1990

Effects of repeated temporary clipping of the middle cerebral artery on pial arterial diameter, regional cerebral blood flow, and brain structure in cats.

Temporary clipping of the major arterial trunk is an important maneuver to control excessive unexpected bleeding in neurosurgical operations; however, repeated temporary clipping can give rise to severe neurological deficits after surgery. The present study was performed to confirm and explain these clinical findings. Initially, a single 20-minute or 1-hour occlusion of the middle cerebral artery was performed in each of 5 cats. Pial arterial diameter was determined by video imaging, regional cerebral blood flow was measured by autoradiography, and cerebral edema and infarction were observed. In the 20-minute occlusion group, no abnormal changes were found 5 hours after recirculation. In the 1-hour occlusion group, pial arteries were dilated by 45%, and regional cerebral blood flow increased to more than twice the resting cortical values. The extent of cerebral edema was 41.2 +/- 7.5% (SE) and infarction was 34.5 +/- 9.5% (SE) of the hemisphere. In the second experiment, three 20-minute occlusions of the middle cerebral artery in a 1-hour interval were performed in 20 cats. In 10 of them, thiopental (40 mg/kg) was used to protect the brain. In the group without barbiturate treatment, pial arteries were dilated by 40% at the end of experiment, regional cerebral blood flow decreased to about 70% compared with single 20-minute occlusion, cerebral edema was 19.5 +/- 8.1% (SE), and infarction was 8.1 +/- 3.7% (SE) of the hemisphere. In the treated group, these were only trivial changes. The effect of repeated clipping may cumulatively cause brain damage, and barbiturates should be used whenever repeated clipping is necessary.

Animals↗

PubMed1990

Tumor growth rate and prognosis of breast cancer mainly detected by mass screening.

To investigate the relationship between the tumor growth rate of the primary breast cancer and its prognosis, records for 122 breast cancer patients in 9 hospitals in Japan were retrospectively reviewed. These records contained at least two measurements of the same tumor mass in the breast. So the growth rate was estimated from these measurements taken at different points in time. The doubling time of the breast tumors showed an approximately log-normal distribution. The geometric mean of doubling times for all cases was 174 days. The solid-tubular histologic type of carcinoma had the shortest geometric mean of doubling time (126 days), the scirrhous carcinoma had the second shortest one (205 days), and the papillotubular carcinoma had the longest one (252 days). The patients with shorter doubling time of tumor tended to have a poorer prognosis. The Cox multiple regression analysis showed that the tumor growth rate was related significantly with survival, after adjusting for other covariates such as clinical stage, lymph node metastasis, age of patient, histological type, and year of treatment.

Adult↗

PubMed1990

[Enzyme-linked immunosorbent assay (ELISA) for Legionella pneumophila using 60-kDa protein antigen].

The enzyme-linked immunosorbent assay (ELISA) has been evaluated for the detection of antibodies against Legionella pneumophila. Three-grade antigens were prepared from Legionella pneumophila serogroup I. Crude antigen was made by enzyme digestion, sonication and centrifugation and then became half pure by ammonium sulfate precipitation. It was purified to form 60-kDa protein antigen by size-exclusion chromatography on a Sephacryl S400 column and ion-exchanged chromatography on a DEAE-5PW column. 60-kDa protein antigen was the most sensitive of the three antigens, but more cross reactive to K. pneumoniae type II than the other two antigens. It is suggested that crossreaction occurs on the grounds whether 60-kDa protein is antigen common to L. pneumophila serogroup I and K. pneumoniae type II or antigens of such two bacteria co-exist on 60-kDa protein.

Antibodies, Bacterial↗

PubMed1990

Control of total peripheral resistance during hyperthermia in rats.

To elucidate the effect of blood volume on the circulatory adjustment to heat stress, we studied alpha-chloralose-anesthetized rats at three levels of blood volume: normovolemia (NBV), hypervolemia (HBV; +32% plasma volume by isotonic albumin solution infusion), and hypovolemia (LBV; -16% plasma volume by furosemide administration). Body surface heating was performed with an infrared lamp to raise arterial blood temperature (Tb) at the rate of approximately 0.1 degree C/min. Before heating, central venous pressure (CVP) was significantly higher in HBV (0.41 +/- 0.25 mmHg) and lower in LBV (-1.44 +/- 0.22 mmHg) than in NBV (-0.41 +/- 0.10 mmHg). The Tb at which CVP started to decrease was approximately 40 degrees C in HBV, approximately 41 degrees C in NBV, and approximately 42 degrees C in LBV, and it decreased by 1.53 +/- 0.14, 1.92 +/- 0.24, and 0.62 +/- 0.14 mmHg from 37 to 43 degrees C of Tb in HBV, NBV, and LBV, respectively. Stroke volume was closely correlated with CVP, and this relationship was not affected by Tb. Heart rate responses to the raised Tb were similar among the three groups. Mean arterial pressure (MAP) was not affected by blood volume modification or CVP and was maintained at preheating (Tb 37 degrees C) level until Tb rose to 40 degrees C. Above this Tb, MAP increased until Tb reached 43 degrees C (+30-40 mmHg) for all three groups. Total peripheral resistance (TPR) was inversely correlated with CVP, and the slope of the linear relationship between TPR and CVP in LBV was three- to fourfold steeper than in NBV or HBV.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1990

Measurement of the electrical bio-impedance of breast tumors.

A new impedance analytical system was developed, and measurements were performed over a frequency range of 0-200 kHz by the three-electrode method. The three electrodes consist of a coaxial needle electrode inserted into the tumor and a large reference electrode on the upper abdominal wall. The electrical bio-impedance was measured in 54 patients with breast tumors. The biological tissue can be regarded electrically as an equivalent consisting of extracellular resistance (Re), intracellular resistance (Ri), and electrical capacitance of the cell membrane (Cm). These three parameters were calculated from the measured values of electrical bio-impedance by the curve-fitting technique using a computer program. It was found that Re and Ri of breast cancers were significantly higher than those of benign tumors (p less than 0.01), and that Cm of breast cancers was significantly lower than that of benign tumors (p less than 0.01). Measurement of the electrical bio-impedance of breast tumors may have value in the differential diagnosis of breast lesions.

Adult↗

PubMed1990

[Evaluation on equivalence of pharmacological properties between natural crude drugs and their cultured cells based on their components. Accelerative effect of lithospermi radix and inhibitory effect of coptidis rhizoma on proliferation of granulation tissue].

The present study was carried out to evaluate an equivalence of pharmacological properties between natural crude drugs and their cultured cells. The effects of ether extract of Lithospermi Radix and cultured cells of Lithospermum erythrorhizon Sieb. et Zucc. and aqueous extract of Coptidis Rizoma and cultured cells of Coptis japonica Makino var. dissecta Nakai on proliferation of granulation tissue in rats were compared. The ether extracts of Lithospermi Radix and the cultured cells enhanced proliferation of granulation tissue by the cotton pellet method. The potency of both extract was about the same, if results were compared with the corresponding doses which contained the same quantity of shikonin derivatives. On the other hand, the aqueous extracts of Coptidis Rhizoma and the cultured cells inhibited it. The potency of both extract was about the same, if results were compared with the corresponding doses which contained the same quantity of berberine-type alkaloids. From these results, to evaluate an equivalence of pharmacological properties between natural crude drugs and their cultured cells, it is concluded that their qualities and quantities are not so different each other and the almost same pharmacological effect expected on the basis of their uses is required.

Alkaloids↗

PubMed1990

[Effect of Y-516 on the hyperactivity induced by dopamine injected bilaterally into the nucleus accumbens].

The effect of Y-516 on the hyperactivity induced by dopamine injected bilaterally into the nucleus accumbens was compared with those of clocapramine (CCP), haloperidol (HPD) and chlorpromazine (CPZ). Dopamine (5-50 micrograms) injected into the nucleus accumbens induced a dose-dependent hyperactivity following pretreatment with nialamide (100 mg/kg, i.p., 2 hr). The hyperactivity induced by 10 micrograms of dopamine was antagonized by the i.p. administration of Y-516 (0.5-1.0 mg/kg), CCP (5-25 mg/kg), HPD (0.05-0.5 mg/kg) and CPZ (1-5 mg/kg) in a dose-dependent manner. The ED50 values of Y-516, CCP, HPD and CPZ were 0.85, 16.5, 0.098 and 2.53 mg/kg, respectively. These results suggest that Y-516 has a potential inhibitory effect on the mesolimbic dopaminergic system and may be a beneficial neuroleptic drugs.

Animals↗

PubMed1990

Thermoregulation and body fluids: role of blood volume and central venous pressure.

Dehydration due to hyperthermia induces both hyperosmolality and hypovolemia. Hyperosmolality reduces evaporative cooling, and alters the thermal responsiveness of the hypothalamic center to changes in both the central and peripheral milieu. Hypovolemia also reduces the thermoregulatory response, but its effect is more variable. The potential sensor of hypovolemia is the CVP, which is influenced by redistribution of blood volume, changes in blood volume, and alterations in cardiac function. The control of CVP is related to the regulation of vascular compliance, stressed blood volume, and unstressed blood volume. Vascular compliance is also involved in the regulation of fluid shifts between the ISF and the intravascular fluid space, and buffers changes in the CVP. Regulation of fluid replacement after thermal dehydration can be considered both from the point of view of osmoregulation and volume regulation. In the rehydration process, control of plasma osmolality precedes blood volume regulation, which also suggests that changes in blood volume sensed as changes in the CVP are regulated within a narrow range by various mechanisms. These findings suggest a hierarchic structure for the homeostatic mechanisms related to thermoregulation, with higher priority being given to the maintenance of cardiac output and the cellular volume of the brain at the expense of peripheral circulation and cell volume.

Animals↗

PubMed1990

Is Chiari I malformation in the aged initiated by mechanical factors? Report of three cases.

Three cases in which the signs and symptoms of Chiari I malformation were induced and worsened after the occurrence of supratentorial mass lesions are reported. The symptoms improved markedly after removal of the supratentorial lesions in these cases. In the first case, a meningioma in the right parietal region coexisted with Chiari I malformation. Although the cerebellar ataxia and nystagmus disappeared after tumor removal, decompressive surgery for the malformation was performed because of upper cervical nerve symptoms and the patient recovered completely. In the second case, the symptoms first occurred after a car accident, and a computed tomographic scan revealed not only a subdural hematoma, but also tonsillar herniation due to Chiari I malformation. After evacuation of the hematoma and decompressive surgery on the craniospinal junction, the symptoms disappeared. In the third case, the symptoms of malformation developed gradually with depression and gait disturbance. A meningioma in the left frontal region coexisted with Chiari I malformation. Although the symptoms improved remarkably after tumor removal, decompressive surgery on the craniospinal junction was performed because of upper cervical nerve symptoms, and the patient recovered completely. These clinical findings indicate that a supratentorial mass lesion may provoke the symptoms of Chiari I malformation in the aged.

Aged↗

PubMed1990

The anomaly of a non-bifurcating cervical carotid artery. Case report.

A case of a rare developmental anomaly of the cervical carotid artery is reported. In this patient the non-bifurcating carotid artery gave origin to all of the branches normally supplied by the external carotid artery and thereafter continued as the internal carotid artery. Embryological events responsible for this anomaly are briefly discussed.

Carotid Arteries↗