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Biomedical subjects

M Fujimoto

Publications and source records attributed to M Fujimoto.

At least 271 records · Page 15Linked to original sources
PubMed1995

Expression of vav proto-oncogene by nonhematopoietic trophoblast cells at the human uteroplacental interface.

Vav is a signal transducing molecule containing SH2 and SH3 domains and a guanine nucleotide releasing factor-like domain. Its expression is thought to be highly specific for hematopoietic cells. Here we describe the expression of vav transcripts in human nonhematopoietic trophoblasts. By northern blotting, expression of 2.8-kb vav mRNA was detected in human decidual, placental, and chorionic villous tissues and in a choriocarcinoma cell line BeWo. By in situ hybridization, vav mRNA was found to be expressed in the cytotrophoblast shell and columns and in the extravillous trophoblasts in the maternal decidua from the first through third trimesters. Vav mRNA was also detected in villous syncytiotrophoblasts during the second and third, but not the first, trimesters. When 1 microM oligodeoxynucleotide antisense to the vav mRNA was added to the medium, growth of BeWo cells was significantly inhibited. These results suggest that vav plays an important role for successful implantation and placental development by regulating development of trophoblasts.

Amino Acid Sequence↗
PubMed1995

Dual mechanisms of GABAA response inhibition by beta-lactam antibiotics in the pyramidal neurones of the rat cerebral cortex.

1. The effects of beta-lactam antibiotics on the gamma-aminobutyric acid (GABA)-induced Cl- current were investigated in pyramidal neurones freshly dissociated from the rat frontal cortex by the use of a nystatin-perforated patch recording mode under voltage-clamp conditions. 2. The GABA-induced inward current increased in a concentration-dependent manner with an EC50 of 6.7 x 10(-6) M at a holding potential of -40 mV. The GABA response was accompanied by an increase in the membrane conductance and reversed at near the Cl- equilibrium potential. 3. All beta-lactams (penicillin, imipenem, aztreonam and cefotiam) inhibited the 10(-5) M GABA-induced response in a concentration-dependent manner with an IC50 and Hill coefficient of 1.3 x 10(-3) M and 0.64 for penicillin, 9.6 x 10(-4) M and 0.83 for imipenem, 2.5 x 10(-3) M and 9.99 for aztreonam, and 2.9 x 10(-4) M and 1.03 for cefotiam. 4. Imipenem inhibited the GABA-response competitively while penicillin inhibited the same response in a noncompetitive fashion. 5. The inhibitory action of imipenem showed no voltage-dependency, whereas the effect of penicillin was voltage-dependent. 6. It is thus proposed that some classes of beta-lactams, including imipenem may have a mechanism that is different from penicillin and competitively affects the GABAA receptor.

Animals↗
PubMed1995

Azygos venous blood flow: measurement with direct bolus imaging.

PURPOSE: To evaluate a magnetic resonance (MR) imaging technique for measurement of azygos blood flow volume, which is an important indicator of superior collateral circulation in patients with portal hypertension. MATERIALS AND METHODS: Azygos blood flow was measured by means of direct bolus (DB) imaging, an MR flow measurement technique. A presaturation pulse was applied in combination with electrocardiographic gating. RESULTS: The measured flow volume was 320 mL/min +/- 30 (mean +/- standard error of mean) in the control subjects, 550 mL/min +/- 130 in patients with cirrhosis of the liver and without varices, and 660 mL/min +/- 60 in patients with cirrhosis of the liver and with varices. The flow volume was significantly higher in each of the groups with cirrhosis of the liver than in the control group (P < .01). Furthermore, a significant correlation was shown between DB imaging and continuous thermodilution measurements (r = .707, P < .01). CONCLUSION: DB imaging, which is noninvasive, was useful in the monitoring of the effect of treatment and in determination of the prognosis in patients with portal hypertension.

Aged↗
PubMed1995

Elevated procollagen type I carboxyterminal propeptide production in cultured scleroderma fibroblasts.

BACKGROUND: We recently reported that the serum concentration of procollagen type I carboxyterminal propeptide (P1CP) in patients with systemic sclereosis (SSc) was elevated. In the present study, we investigated collagen metabolism in in vitro cultured scleroderma fibroblasts by measuring P1CP levels in the culture medium. METHODS AND RESULTS: Spontaneous P1CP production was 4.2 times higher in fibroblast cultures from patients with SSc (n = 11) than in those from healthy controls (n = 10). P1CP production in fibroblasts derived from diffuse cutaneous SSc patients was significantly greater than that from limited cutaneous SSc patients. The serum P1CP level in SSc patients was correlated with the P1CP production of cultured fibroblasts (r = 0.815, p < 0.005). Transforming growth factor beta increased P1CP production, and gamma-interferon decreased P1CP production similarly in both SSc and normal fibroblasts. In contrast, histamine dihydrochloride increased P1CP production only in SSc fibroblasts but not in controls. CONCLUSION: These findings suggest that P1CP production in SSc fibroblasts is relevant to in vivo collagen synthesis in SSc patients.

Adolescent↗
PubMed1995

Induction of tissue inhibitor of metalloproteinase 3 gene expression during in vitro decidualization of human endometrial stromal cells.

Endometrial stromal differentiation (decidualization) is essential for implantation of the developing blastocyst. To investigate the process of progesterone (P)-induced decidualization of human endometrial stromal cells (ESC), a complementary DNA library enriched with P-induced genes was constructed from cultured human ESC by subtractive hybridization and the polymerase chain reaction. One of the isolated clones was the complementary DNA for the tissue inhibitor of metalloproteinase-3 (TIMP-3), a recently identified member of the human TIMP family. When human ESC were cultured in the presence of P for 6 days, the induction of TIMP-3 messenger RNA (mRNA) expression was observed by Northern blotting. In contrast, the marked induction of PRL mRNA expression and morphological changes were observed after 9 days of culture. P-induced TIMP-3 mRNA expression was dose dependent, and this induction was inhibited by the antiprogestin RU486. Estrogen did not induce TIMP-3 mRNA expression under similar conditions. In situ hybridization analysis of endometria from nonpregnant women revealed that the TIMP-3 mRNA expression was restricted to predecidualized stromal cells. At the feto-maternal interface, TIMP-3 expression was observed in fetal extravillous trophoblasts that had invaded the maternal decidual tissues as well as in the maternal decidual cells. These findings suggest that TIMP-3 is a sensitive indicator of ESC decidualization, and that the induction of TIMP-3 expression in decidual cells and trophoblasts may be important in the regulation of trophoblast invasion.

Adult↗
PubMed1995

Regulation of sex steroid receptor gene expression by progesterone and testosterone in cultured human endometrial stromal cells.

Progesterone (P) is known to regulate sex steroid receptors in uterine cells. However, its precise regulation at the messenger ribonucleic acid (mRNA) level is unclear. In this study we examined the effects of P and testosterone (T) on the regulation of sex steroid receptors in cultured human endometrial stromal cells (ESC), using the quantitative reverse transcriptase polymerase chain reaction method. We isolated ESC from human endometrial tissues and cultured them with or without P (10(-6) mol/L) or T (10(-8) mol/L) for 9 days. Incubation with P decreased progesterone receptor (PR), estrogen receptor, and androgen receptor mRNA levels in cultured human ESC to 0.56 +/- 0.04-, 0.53 +/- 0.08-, and 0.84 +/- 0.04-fold (mean +/- SE), respectively. T also decreased PR, estrogen receptor, and androgen receptor mRNA levels in cultured human ESC to 0.48 +/- 0.06-, 0.52 +/- 0.05-, and 0.82 +/- 0.04-fold (mean +/- SE), respectively. These decreases by P and T occurred in a dose-dependent manner. We also examined the sex steroid receptor levels in human ESC cultured for 0, 3, 6, and 9 days. The PR mRNA level in ESC without P was increased in a time-dependent manner. This increase was also inhibited by P, and the mRNA level in the presence of P was almost constant throughout the culture period. Our results demonstrated that P or T is a regulator of sex steroid receptors in ESC and that this regulation may influence the responsiveness to P of decidual change in ESC.

Base Sequence↗
PubMed1995

Disappearance of arachnoid cysts after head injury.

The mechanism of the disappearance of arachnoid cysts is not fully understood. This article discusses the spontaneous disappearance of these cysts after head injury. Five patients underwent computed tomography and were diagnosed as having a subdural hematoma or effusion associated with arachnoid cysts. In four of the five patients, the cyst decreased in size or disappeared. These cases suggest a possible mechanism by which this type of cyst associated with subdural hematoma or effusion might disappear. For the arachnoid cyst to disappear, the rupture of the cyst wall appears to be essential, and after rupture, subdural effusion must develop around the cyst. As this effusion is absorbed, the fluid in the cyst drains away, after which the cyst becomes smaller and gradually disappears. This hypothesis supports the possibility of a "natural cure" for arachnoid cysts without surgical intervention.

Adolescent↗
PubMed1995

Synthesis and evaluation of novel nonpeptide angiotensin II receptor antagonists: imidazo[4,5-c]pyridine derivatives with an aromatic substituent.

Starting from recently reported nonpeptidic angiotensin II (AII) receptor antagonists, we have designed and prepared a new series of 6-arylimidazo[4,5-c]pyridine derivatives. Variation of phenyl groups at the 4-, 6- or 7-position of imidazo[4,5-c]pyridine showed that substitution at the 6-position resulted in receptor-binding activity almost as potent as that of DuP 753. This led to synthesis and evaluation of an extensive series of 6-aryl-imidazo[4,5-c]pyridine derivatives. Some of them were 4-fold more potent in vitro than DuP 753, but only showed weak antihypertensive activity in vivo when given orally to rats.

Angiotensin Receptor Antagonists↗
PubMed1995

Synthesis and evaluation of novel pyrazolo[1,5-alpha]pyrimidine derivatives as nonpeptide angiotensin II receptor antagonists.

A novel series of 6-alkyl-7-oxo-4,7-dihydropyrazolo[1,5-alpha]pyrimidine-3-carboxyli c acid derivatives was prepared as angiotensin II (AII) receptor antagonists. When evaluated in an in vitro binding assay using COS cells transfected with a cDNA encoding a human AT1 angiotensin II receptor, the compounds in this series showed Ki values in the range of 0.4-4.0 nM. In anesthetized spontaneously hypertensive rats (SHRs), administration of the 6-propyl derivative 4d (1 mg/kg, i.v.) reduced the mean blood pressure (MBP) by a maximum of more than 30 mmHg from the normal value.

Angiotensin II↗
PubMed1995

Enhancement of resistance to bacterial infection in mice by vitamin B2.

We found that the intramuscular injection of vitamin B2 enhanced host resistance to E. coli infection in a dose-dependent manner (6.25 mg/kg-100 mg/kg). Furthermore, VB2 exhibited the protective activity against Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus, and Actinobacillus pleuropneumoniae. The mechanism of action of VB2 for enhancing resistance in mice may be, at least in part, its ability to stimulate the multiplication of neutrophils and monocytes, and to activate macrophages.

Actinobacillus Infections↗
PubMed1995

Occurrence of Graves' disease during retreatment with interferon-alpha 2a for chronic hepatitis C.

The present report describes a patient who developed Graves' disease 3 months after inception of retreatment with higher doses of interferon-alpha 2a for chronic hepatitis C, although the initial 6-month treatment caused no serious adverse reactions. Severe hyperthyroidism continued despite discontinuation of interferon-alpha 2a, and the patient was subsequently treated with 131I. This case suggests careful evaluation of the safety of retreatment to prevent manifestation of such a complication in the retreatment of chronic hepatitis C with interferon.

Adult↗
PubMed1995

Proximal tubular cell alkalinization induced by Na(+)-glucose cotransport.

To study the ionic mechanisms of crosstalk between luminal and peritubular membranes induced by Na(+)-glucose cotransport in the proximal tubular cells, we applied the ion-selective microelectrode techniques and measured intracellular ion activities of Na+ (Nai) and H+ (pHi), as well as peritubular membrane potential (EM) in doubly-perfused bullfrog kidney. In control conditions with peritubular HCO3- (15 mM), luminal perfusion with 10 mM D-glucose induced a 12 mV depolarization of peritubular membrane (glucose-induced depolarization) with a transient increase in Nai by 3 mM and an elevation in pHi by 0.1. In the absence of peritubular HCO3- (HEPES-Ringer at constant pH), the luminal glucose produced a sustained increase in Nai and suppression of pHi elevation without affecting glucose-induced depolarization. Peritubular perfusion with DIDS (10(-4) M) abolished the change in pHi induced by luminal glucose. Furthermore, the luminal glucose increased the transport number for K+ (gK/gm) in the peritubular membrane by 20%. These results suggest that 1) glucose-induced depolarization suppresses peritubular HCO3- exit, followed by an elevation in pHi, 2) the luminal glucose increases K+ conductance of the peritubular membrane, probably by the elevation in pHi, and 3) this increased K+ conductance repolarizes the peritubular membrane, which can support the driving force for Na(+)-glucose entry across the luminal membrane. Thus, we conclude that the crosstalk between peritubular and luminal membranes by Na(+)-glucose cotransport is mainly modulated by changes in cell pH and membrane potential in the proximal tubule.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1995

The stimulatory effects of PDGF and TGF-beta 1 on dermal fibroblast attachment.

We investigated the effects of various growth factors (platelet-derived growth factor (PDGF), epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), transforming growth factor-alpha (TGF-alpha), transforming growth factor-beta 1 (TGF-beta 1), tumor necrosis factor-alpha (TNF-alpha), keratinocyte growth factor (KGF)) on fibroblast attachment to plastic plates. It is thought that cell attachment to plastic plates in vitro may represent the step between cell migration and proliferation in vivo during wound healing. Among the growth factors examined, only PDGF and TGF-beta 1 significantly increased fibroblast attachment to both uncoated and collagen-coated plates in a concentration-dependent manner. The addition of anti-PDGF antibody abolished the enhancing effect of PDGF but not that of TGF-beta 1, suggesting that the effect of TGF-beta 1 is not through the autocrine induction of PDGF-related activities secreted by the fibroblasts themselves. These data suggest that PDGF and TGF-beta 1 regulate fibroblast attachment to the suitable environment in the process of dermal wound healing in vivo.

Adult↗
PubMed1995

Observation of head-shaking nystagmus with an infrared Frenzel's glass.

It has been reported that a head-shaking test is very useful in clinical practice. To observe head-shaking nystagmus (HSN) a Frenzel's glass and electronystagmography (ENG) have been used. Although observation with Frenzel's glass is a simple method, it tends to suppress after shaking nystagmus, as gazing is not completely eliminated with Frenzel's glass. An electronystagmogram in darkness can eliminate gazing completely, but it requires much trouble in routine use. We therefore tried to use Frenzel's glass with an infrared CCD camera. We observed highly provoked HSN like ENG in darkness and were able to use it without difficulty. We recognized the second phase in several cases with only an infrared Frenzel's glass and the rotatory component of the nystagmus. This method is more convenient and valuable for clinical use than ENG and Frenzel's glass.

Dizziness↗
PubMed1995

[A study of the relationship between nocturnal intragastric pH and sleep stages of peptic ulcer].

We studied the correlation of the gastric acid secretion and the depth of sleep at night with no medication in 32 cases (19 gastric ulcer, 6 duodenal ulcer patients and 7 healthy controls). Using Memory PH: Monitor intragastric pH values were consecutively measured without antiulcer drugs. The depth of sleep were monitored continuously by recording without any sleeping drugs. In healthy controls, the pH values of awake phase was significantly lower than that of sleep stage 1, 4 and rapid eye movement (REM) phases. The pH values of REM phases were significantly high rather than that of sleep stage 1 and 2 phases. In patients with gastric ulcer, the pH values of awake phases were significantly lower than that of sleep stage 1 and REM phases. The pH values of REM phases were significantly high rather than that of the other sleep stages. On the other hand, in patients with duodenal ulcer, the obvious changes of the pH values were not seen with sleep stages. The pH values of healthy controls and gastric patients were changed with sleep stages. But the pH of duodenal ulcer patients were not changed obviously. Therefore, it is suggested that the dysfunction of autonomous nervous system was influenced the nocturnal intragastric pH in the patients with duodenal ulcer and played one of the important role in the occurrence of duodenal ulcer.

Adult↗
PubMed1995

[A case of subarachnoid hemorrhage with acute subdural hematoma due to head injury: a case report].

Acute intracranial hemorrhages can be caused by cerebrovascular disease or head injury. Diagnostic imaging is in both cases sometimes similar, so it is difficult to make an exact diagnosis. We report a case of acute subdural hematoma due to head injury after loss of consciousness due to an aneurysmal rupture. A 52-year-old male was found out fallen on the floor in a state of unconsciousness and was brought to the nearest hospital. CT scan showed subarachnoid hemorrhage with left acute subdural hematoma and he was transported to our hospital. Angiography revealed a left MCA aneurysm. The next day, a clipping operation was performed but brain contusion was observed in the left frontal lobe. Postoperative CT scan showed contusional hematoma at the left frontal lobe and plain skull X-ray films demonstrated a diastatic fracture of the right lambdoid suture. Acute subdural hematoma due to the rupture of a cerebral aneurysm is sometimes recognized, but the first CT findings are similar to those observed after head injury. When the clinical course of onset is unclear, we must keep in mind that the cause of acute subdural hematoma may be head injury, even if angiography demonstrates abnormal vessels.

Acute Disease↗
PubMed1995

Serum aldolase level is a useful indicator of disease activity in eosinophilic fasciitis.

The serum levels of muscle enzymes have been considered normal in patients with eosinophilic fasciitis (EF). We observed elevated serum aldolase levels in 3 patients with EF. Serum creatinine kinase levels were within the normal range. We measured the aldolase levels longitudinally. In all patients, the levels decreased to the normal range after oral corticosteroid treatment, and skin sclerosis improved. Afterwards, serum aldolase levels increased again, with the recurrence of skin sclerosis. These observations suggest that serum aldolase level may be a useful indicator of disease activity.

Adult↗