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Biomedical subjects

T Fujikawa

Publications and source records attributed to T Fujikawa.

At least 91 records · Page 5Linked to original sources
PubMed1996

Induction of brain prolactin receptor long-form mRNA expression and maternal behavior in pup-contacted male rats: promotion by prolactin administration and suppression by female contact.

Prolactin (PRL) is considered to induce maternal behavior toward foster young in female rats. In the present study, we studied the relationship between pup contact-induced maternal behavior and serum PRL concentrations and brain PRL receptor (PRL-R) mRNA expression in male rats. Both intact and castrated male rats exposed to foster pups gradually developed caretaking behavior such as crouching and licking, but their exhibitions of other maternal behavior components, retrieval/grouping and nest building, were incomplete. However, in the male rats displaying crouching and licking, the concomitant increases in serum PRL concentration and brain mRNA expression for long-form PRL-R were observed. The expression of short-form PRL-R mRNA in the brain was not stimulated by pup contact. Administration of PRL remarkably promoted the onset of those maternal responses in male rats. On the other hand, when an intact male rat was housed in a cage where a lactating female rat and her pups were living, his scores in maternal behavior tests toward pups were lowered. And, concomitantly, increases in serum PRL concentration and brain expression of long-form PRL-R mRNA were reduced. In castrated male rats, however, the ratings of maternal behavior toward foster young, serum PRL concentration increase, or brain long-form PRL-R mRNA expression were not reduced at all by cohabitation with a female and her pups. These findings indicated that maternal behavior was triggered and maintained in pup-contacted male rats through elevated serum PRL levels and induced brain long-form PRL-R.

Animals↗
PubMed1996

Response of patients with major depression and silent cerebral infarction to antidepressant drug therapy, with emphasis on central nervous system adverse reactions.

BACKGROUND AND PURPOSE: We previously found that silent cerebral infraction (SCI) is present in most patients older than 50 years with major depression. The present study was designed to clarify the response to antidepressant pharmacotherapy in patients with major depression associated with SCI. METHODS: Using clinical charts, we retrospectively studied patients older than 50 years who were admitted for antidepressant drug therapy. Patients with bipolar affective disorder and those with focal neurological symptoms were excluded. All patients underwent magnetic resonance imaging and were classified as SCI-negative or SCI-positive. The SCI-positive group was subclassified into those with moderate SCI (either perforating area or cortical area) (n = 15) and those with severe SCI (both perforating and cortical areas) (n = 7). Duration of treatment in hospital and the incidence of central nervous system adverse reactions to the antidepressant drugs were compared between the two groups. RESULTS: The duration of hospital treatment in patients with severe SCI was significantly longer than in those with moderate SCI (P < .01). The percentage of patients with adverse central nervous system reactions to antidepressant drugs was significantly higher in the SCI-positive group than in the SCI-negative group (P < .05). Patients with severe SCI had significantly more adverse reactions than those with moderate SCI (P < .05). CONCLUSIONS: Depressed patients with severe SCI required longer hospital treatment and had more drug-related adverse reactions of the central nervous system. These findings suggest that the depression associated with severe SCI may be resistant to treatment.

Aged↗
PubMed1996

Protective effects of Acanthopanax senticosus Harms from Hokkaido and its components on gastric ulcer in restrained cold water stressed rats.

The aim of this study is to investigate the pharmacological effect of the stem bark of Acanthopanax senticosus Harms from Hokkaido (Japanese name: Ezoukogi) in place of the root bark as a restorative tonic on the stress-induced gastric ulcer. In the test, the extract of the stem bark of A. senticosus prepared with hot water was dissolved in water and used for the assay of the protective effect of gastric ulcer (erosion) on stressed rats that were restrained on cold water. The result from a single oral administration of the stem bark of A. senticosus-extract (50, 100 and 500 mg/kg, per day) dissolved in 1 ml distilled water did not show any protective effect on gastric ulcer, but the protective effect was observed in a dose-dependent manner from the oral administration of the extract (50, 100 and 500 mg/kg, per day) for 2 weeks. Pre-administration of the stem bark of A. senticosus-extract in a dose of 500 mg/kg showed the most potent inhibition without affecting either body or adrenal glands weights. Among ether, chloroform, n-butanol and aqueous residue extracts from the stem bark of A. senticosus-extract, the n-butanol extract used for oral administration for 2 weeks showed an obvious inhibition of 61.1% on gastric ulcer, compared with the control group which was treated with distilled water in the same way. Chlorogenic acid and syringaresinol di-o-beta-D-glucoside, as the major components of the n-butanol extract, showed a significantly inhibitory effect on gastric ulcer, at 21.4% and 51.3%, respectively. We suggested that the protective effect of the stem bark of A. senticosus on gastric ulcer may be partially due to those of chlorogenic acid and syringaresinol di-o-beta-D-glucoside.

Adrenal Glands↗
PubMed1995

Silent cerebral infarctions in patients with late-onset mania.

BACKGROUND AND PURPOSE: Previously we have studied the relationship between senile depression and silent cerebral infarctions (SCIs). The goal of this study was to clarify the relationship between late-onset mania and SCIs using MR imaging. METHODS: Twenty manic patients who developed a bipolar disorder after 50 years of age (late-onset mania) were selected prospectively. These patients were compared with 20 age- and sex-matched patients who developed an affective disorder while younger than 50 years of age (early-onset affective disorder) and with 20 patients who developed major depression after 50 years of age (late-onset major depression). Patients with focal neurological symptoms were excluded from the study. All patients underwent MR imaging to assess the incidence of SCIs. Patients diagnosed with SCIs were subclassified according to whether the infarction type was perforating, cortical, or mixed. RESULTS: The incidence of SCIs in patients with late-onset mania was 65.0%; this incidence was significantly higher than that of patients with early-onset affective disorders (P < .05). The incidence of the mixed type of SCI was 50.0% in patients with late-onset mania; this was significantly higher than that in patients with late-onset major depression (P < .05). CONCLUSIONS: Our findings suggest that approximately half of the cases of late-onset mania might be secondary mania related to SCIs. Because the mixed type of SCI is more prevalent in the patients with late-onset mania than in those with late-onset major depression, mania may be associated with the larger areas of brain damage and hence may be a more serious form of affective illness than major depression.

Age of Onset↗
PubMed1995

Restraint stress enhances the gene expression of prolactin receptor long form at the choroid plexus.

Hormonal control of brain functions is considered to be important in the tolerance of stress, and it is now established that stress elevates serum PRL levels in male or cycling female rats. To investigate whether or how serum PRL acts on the brain during exposure to stress, we analyzed serum PRL levels and the gene expression of brain PRL receptors in rats subjected to restraint stress in the water (RSW). The serum PRL concentration was remarkably increased within 30 min in the rats by exposure to RSW and decreased to the initial level after 4 h of RSW, remaining at this level for up to 7 h of RSW. After the rats were released from the stress, the serum PRL level was significantly lowered in 6 h. Ribonuclease protection assay and in situ hybridization analysis revealed that messenger RNA (mRNA) expression for the long form PRL receptor [PRL-R(L)] was remarkably induced in the rat choroid plexus in 2 h of RSW. The high expression level of PRL-R(L) mRNA in the region was reduced after the rats were released from the stress. PRL-R(L) mRNA expression in the hypothalamus was at lower levels than those in the choroid plexus before and during the RSW treatment. The short form PRL receptor mRNA expression in the rat brain was considerably lower than expression of the long form receptor mRNA before or during RSW. The results indicated that the restraint stress caused a rapid increase in serum PRL and induced the gene expression for PRL-R(L) in the choroid plexus, suggesting stress-induced and choroid plexus PRL-R(L)-mediated transport of serum PRL into the cerebrospinal fluid.

Animals↗
PubMed1995

[Inhibitory effects of Forskolin on hepatic metastasis from human colon cancer in nude mice].

Platelet aggregation has been believed to play an important role in implantation of tumor cells into the target organ during the early phase of tumor metastasis. In the present study, the effects of Forskolin, a strong platelet aggregation inhibitor, on experimental hepatic metastasis from human colon cancer (HT29LMM) in nude mice and inhibitory effects of Forskolin on platelet aggregation in the presence of tumor cells were evaluated. A hepatic metastasis model was established by intrasplenic implantation of 3-4 x 10(6) of HT29LMM human colon cancer cells in nude mice. Intraperitoneally 10mg/kg of Forskolin was given 30 minutes before and 24 hours, after implantation of tumor cells, respectively. The control group received saline instead of Forskolin. Phase of hepatic metastasis has been compared for the total weight of hepatic metastatic lesions and the occupied rate between the Forskolin-given group and the control group. The total weight of hepatic metastasis lesions (0.36 +/- 0.33g (SD) vs 3.36 +/- 1.31g) and the occupied rate (8.22 +/- 7.91% vs 67.9 +/- 23.2%) were significantly low in the Forskolin-given group compared with the control group. In vitro inhibitory effects of Forskolin on platelet aggregation was recognized under the presence of HT291LMM. This study suggests that the platelet aggregation inhibitor drug. Forskolin, inhibits hepatic metastasis from human colon cancer by preventing platelet aggregation during the metastatic tumor formation.

Animals↗
PubMed1994

Clearance of circulating endothelin-1 by ETB receptors in rats.

Exogenous endothelin (ET) is rapidly cleared from the circulation. We investigated which ET receptor subtypes (ETA and ETB) participate in ET-1 clearance. Following an intravenous (i.v.) bolus dose of [125I]ET-1 in anesthetized rats, radioactivity was rapidly cleared from the circulation and trapped by the lungs, kidneys and liver. Tissue distribution of the radioactivity was significantly inhibited in the lungs and kidneys, but not in the liver by infusion of the ETB antagonist BQ-788 (0.1 mg/kg/min i.v.), and the ET-1 clearance rate was reduced, while the ETA antagonist BQ-123 had no such effect. Furthermore, in isolated perfused rat lungs, about 80% of bolus-injected [125I]ET-1 was retained by the lungs after one passage. The retention of ET-1 was significantly inhibited by infusion of 1 microM BQ-788, but not BQ-123. These results suggest that ETB receptors play an important role in the clearance of ET-1.

Analysis of Variance↗
PubMed1994

A cranial invasion model of human neuroblastoma using congenitally athymic mice.

Even though the current limits of treatment for advanced stage neuroblastoma require an understanding of biology and new therapeutic approaches, few invasion models of human neuroblastoma (HNB) which evaluate experimental therapies have been reported. We describe herein a reproducible murine model of cranial invasion after the intraocular xenograft of HNB in congenitally athymic mice. Approximately 10 weeks after the intraocular injection of 5 x 10(6) NB-1 HNB cells, 70% (14/20) of the mice developed intracranial invasion with skull involvement. There was no operative mortality. Macroscopically, deformities of the cranium were revealed in all 14 mice, 5 of which developed exophthalmos. Microscopically, cranial invasion mainly involved the extradural space, skull, and orbita; however, brain involvement could not be seen, indicating that the dura may act as a barrier. These invasive characteristics are very similar to those seen in humans; thus, we believe that this model provides a useful tool for evaluating the biology of, and new therapeutic approaches against, cranial invasion of neuroblastoma in vivo.

Animals↗
PubMed1994

Background factors and clinical symptoms of major depression with silent cerebral infarction.

BACKGROUND AND PURPOSE: We previously reported that major depression developing during or after the presenile period is frequently combined with silent cerebral infarction and that these patients have a high risk of stroke. Therefore, we investigated whether the background factors and clinical symptoms of patients with major depression with silent cerebral infarction [SCI(+)] different from those in patients with major depression without silent cerebral infarction [SCI(-)] before medical treatment. METHODS: Patients with major depression with onset after 50 years of age were classified based on magnetic resonance imaging findings into the SCI(+) (n = 37) or SCI(-) (n = 20) group. The diagnostic criteria for major depression were those of the American Psychiatry Association (DSM-III-R). Patients with stroke or focal neurological symptoms were excluded. The SCI(+) group was subclassified according to whether the infarction area was perforating, cortical, or mixed artery. Family history of affective disorder, risk factors for stroke, and Zung's Self-rated Depression Scale (SDS) score before medical treatment of the group were compared. RESULTS: The SCI(+) group had a significantly lower (P < .05) frequency of family history of affective disorder but a significantly higher (P < .01) frequency of hypertension than did the SCI(-) group. The mean SDS score in the SCI(+) group was significantly higher than that in the SCI(-) group (P < .01). The mean SDS score of the mixed artery infarction group was higher than that of the perforating artery infarction group (P < .05). CONCLUSIONS: Patients with major depression with silent cerebral infarction present more marked neurological factors and more severe depressive symptoms than do those without silent cerebral infarction. Because these features were more prominent in the patients with mixed artery infarction with broad obstructions, we consider that the area of brain damage caused by cerebral infarction is positively related to the severity of depressive symptoms.

Aged↗
PubMed1994

[Study on development of linear-traction type skeletal muscle powered pump].

We successfully developed Linear-Traction Type Skeletal Muscle Powered Pump (LSMPP). Unlike the Insertion-Type SMPP (ISMPP), previously used by us, in which a polyurethane chamber is inserted between skeletal muscle and chest wall, this pump can utilize the traction of muscle fiber in a linear direction. This pump also enabled us to obtain a sufficient flow with a low preload by the use of a spring for the filling of the pump. Comparison was made between the measurement of flow using the origin side of Latissimus Dorsi Muscle (o-group) (n = 6) and that using the upper arm side (i-group) (n = 6), both measured with the Linear-Traction Type equipment, and the result obtained with the ISMPP (s-group) (n = 6). Under a rate of 60 beat/min and a preload of 40 mmHg, the flows (ml/min) of o-group, i-group and s-group were 668.0 +/- 108.0, 1202 +/- 478.6 and 620.0 +/- 188.0, respectively. In i-group (n = 6), different rate, preload and spring constant were given to examine how the flow would vary with them. Mean flow (Mean +/- Std ml/min) was 815.0 +/- 378.0 at 60 beat/min, significantly different in comparison with that of 80 beat/min and that of 100 beat/min. For 40, 30 and 20 mmHg of preloads, mean flows were 877.0 +/- 366.0, 625.0 +/- 311.0 and 422.0 +/- 270.0, respectively. This showed that, as far as the rate remains low, even low preload can provide some 30% of the cardiac output of a dog as compensate cardiac flow. In contrast, there were no significant differences in mean flow with spring constants such as 0, 80, 160, 240 and 320 g/cm.

Animals↗
PubMed1994

[Magnetic resonance in patients with affective illness--relationship with silent cerebral infarction].

We reviewed the relationship between affective disorder and magnetic resonance imaging (MRI). There are many reports that elderly patients with depression had increased small deep white matter lesions than the normal control. We examined silent cerebral infarction (SCI) in patients with presenile and senile major depression. Our findings suggest that half of presenile-onset major depression and the majority of senile-onset major depression might be organic depression related to SCI. Because patients with depressive states with SCI are at high risk of occurrence of stroke, we designated this condition "pre-stroke depression". It is important to begin therapy for cerebrovascular disease at this time.

Age of Onset↗
PubMed1993

Quantitative analysis of distribution and fate of human lung cancer emboli labeled with 125I-5-iodo-2'-deoxyuridine in nude mice.

The chemical and radio toxicity of 125-5-iodo-2'-deoxyuridine (125IUDR) on 870127T human lung cancer (HLC) cells grown in tissue cultures and the quantitative analysis of the distribution and fate of 125IUDR-labeled 870127T HLC cells in nude mice were evaluated. After 870127T HLC cells were plated and 125IUDR was added to the dishes at levels ranging from 0.1 microCi/ml to 5.0 microCi/ml of media, the growth rate of the cells for 24 h was similar to that of non-labeled cells. Nude mice were given intravenous injections of 125IUDR labeled 870127T HLC cells and killed at various intervals ranging from 5 min to 24 h after injection. Organs were collected, processed, and monitored. The lung contained most of the tumor cells at all intervals and the number of tumor cells in the lung decreased gradually post-injection. The tumor cells died rapidly, and only about 1.5% of all cell survived after 24 h post-injection. This study confirmed that very few surviving tumor cells are needed to cause metastasis.

Adenocarcinoma↗
PubMed1993

Thoracoscopic pulmonary resection in two cases using an endoscopic linear stapler and loop ligature.

Recent advances in rigid endoscopic imaging capabilities, light sources, and instrumentation have dramatically expanded the potential role of laparoscopic and thoracoscopic surgery. Moreover, the recent introduction of an endoscopic linear stapling device and loop ligature has made thoracoscopic pulmonary resection possible. We present herein two cases of peripheral pulmonary lesions which were resected thoracoscopically. Case 1 was a 19-year-old man with a history of recurrent pneumothorax due to a left apical bulla who underwent thoracoscopic lung resection using a new stapling device, and Case 2 was a 46-year-old man with a small pulmonary lesion on the left basal segment (S8) who underwent thoracoscopic lung resection using loop ligature. Postoperatively, there was no evidence of air leak in either patient and both were discharged 6 days after surgery. The technical procedures for thoracoscopic lung resection and the clinical courses of both patients are described in this paper.

Adenocarcinoma↗
PubMed1993

Incidence of silent cerebral infarction in patients with major depression.

BACKGROUND AND PURPOSE: There have been few studies of the incidence of silent cerebral infarction detected by magnetic resonance imaging in patients with presenile or senile major depression. METHODS: We examined silent cerebral infarction in patients with presenile and senile major depression who were diagnosed at Hiroshima Prefectural Hospital. The diagnostic criteria of the American Psychiatric Association (DSM-III-R) were used. Patients with stroke or focal neurological symptoms were excluded. RESULTS: Silent cerebral infarction was observed in 51.4% of the patients with presenile-onset presenile depression, and the incidence was significantly higher than in patients with juvenile-onset presenile depression (P < .01). Among the patients with senile major depression, silent cerebral infarction was observed in 65.9% of those with presenile-onset depression and in 93.7% of those with senile-onset depression. CONCLUSIONS: Our findings suggest that half of presenile-onset major depression and the majority of senile-onset major depression might be organic depression related to silent cerebral infarction. Because major depression occurring for the first time during or after the presenile period may be related to silent cerebral infarction, it is important to keep this possibility in mind when treating such patients.

Age of Onset↗
PubMed1993

[Case report of miliary TB, with mediastinal TB involving the aorta, trachea and esophagus with death due to hemorrhage from perforation of aorta into the esophagus during treatment].

A 32-year-old male was diagnosed as having miliary tuberculosis in May 1990. In spite of antituberculosis chemotherapy, he developed tuberculous meningitis and intracranial tuberculoma in September 1990. Miliary shadows on chest X-ray disappeared in December 1990. However, he developed left atelectasis, and bronchofiberscopy revealed soft tumor in the left main bronchus in January 1991. He suddenly vomited large amounts of blood and expired in February 1991. At autopsy, tuberculous lymphadenitis and cavitation were noted in the mediastinum, through which the left main bronchus, esophagus and descending aorta communicated. The patient died of massive bleeding which resulted from the rupture of tuberculous aortitis into the esophagus. This is a very rare case of tuberculous aortic aneurysm rupturing into both the bronchus and esophagus.

Adult↗