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Biomedical subjects

H Tajima

Publications and source records attributed to H Tajima.

At least 19 recordsLinked to original sources
PubMed1995

[Secondary porphyrinuria].

The condition that the porphyrins are excreted into the urine due to impairment of bile excretion, is called as secondary porphyrinuria. The main porphyrin is coproporphyrin, there fore the condition is called as secondary coproporphyrinuria. Secondary porphyrinuria is associated with various disorders, such as hepatobiliary diseases, hereditary hyperbilirubinemia, intoxications, blood and metabolic diseases, but the etiology of secondary porphyrinuria is unclear. Coproporphyrin is divided into two isomers, one is coproporphyrin-I type and the other is coproporphyrin-III type. In normal human urine, coproporphyrin-III type is predominant, and the ratio of coproporphyrin-I to total coproporphyrin is 10-50% (% as isomer I), while in urines of hepatobiliary diseases, the ratio is 40-60%. In Dubin-Johnson syndrome, the ratio is 80-100%. Coproporphyrinuria in hepatocellular carcinoma and alcoholic liver disease may be different from that in hepatobiliary diseases, often associated with uroporphyrinuria as well as coproporphyrinuria. Coproporphyrinuria arising in blood and metabolic diseases must be taken into account of associated liver diseases.

Biliary Tract Diseases↗
PubMed1995

[Superselective local infusion therapy with tissue-plasminogen activator for acute massive pulmonary thromboembolism: preliminary clinical experience].

Three cases of acute massive pulmonary thromboembolism were treated with the superselective infusion of tissue-plasminogen activator. Superselective pulmonary angiography immediately after administration of tissue-plasminogen activator demonstrated angiographic improvement in all patients. No complications were encountered during or after the procedure. It is considered that superselective infusion of tissue-plasminogen activator can be an effective therapy for massive pulmonary thromboembolism.

Acute Disease↗
PubMed1995

[MR angiography of the venous system of lower extremities with gadolinium-enhanced fast spoiled GRASS].

MR angiography (MRA) of the venous system of the lower extremities was carried out in 10 patients with varicose veins using the Gd-DTPA-enhanced Fast Spoiled GRASS (FSPGR) method. The quality of imaging of the popliteal vein (n = 20), calf deep vein (n = 20), varicose vein (n = 12), and femoral vein (n = 6) were assessed in terms of four categories: excellent, good, marginally adequate and nondiagnostic. Nineteen popliteal veins, seventeen calf deep veins, and nine varicose veins were judged as excellent or good. All femoral veins were evaluated as excellent. Enhanced FSPGR was useful for the preoperative evaluation of patients with varicose veins.

Femoral Vein↗
PubMed1994

[Stent placement without thrombolysis in chronic iliac arterial occlusion: preliminary clinical evaluation].

Intra-arterial stent placement without thrombolytic therapy was performed in four patients with chronic iliac arterial occlusion. The length of angiographically observed occluded lesions ranged from 2.0 cm to 14.0 cm (mean: 5.1 cm). The implanted stents included four Wall stents, two Strecker stents and one Palmaz stent. The mean ankle-arm index before and after stenting improved from 0.48 to 0.77, while the mean pressure gradient improved from 82.5 mmHg to 3.0 mmHg. Symptoms were eliminated in all patients after the procedure. No major complications were encountered during the procedure. Primary stent implantation in chronic iliac occlusions is useful to avoid bypass surgery.

Aged↗
PubMed1994

[Three-dimensional imaging of portal and hepatic veins using helical CT with intravenous injection of contrast medium].

The authors developed a simple new method for obtaining three-dimensional helical CT images that simultaneously depict both the portal and hepatic veins. One hundred ml of contrast medium was injected intravenously, and helical CT was carried out. Three-dimensional venous images were successfully displayed with rotational movement on the CRT monitor. The new method provided high-quality images in which the anatomical relationship between the portal and hepatic venous systems could be clearly visualized. This information was useful in helping angiographers to successfully perform transjugular intrahepatic portosystemic shunt and will be of great value for the presurgical planning of hepatic resection.

Adult↗
PubMed1994

Risk of hepatocellular carcinoma in patients with cirrhosis in Japan. Analysis of infectious hepatitis viruses.

BACKGROUND: The development of hepatocellular carcinoma (HCC) is associated closely with cirrhosis. In the present study, the cumulative risk of HCC in patients with cirrhosis was investigated. METHODS: A total of 401 patients were registered from April 1977 and followed for a mean of 4.4 years. Of 401 patients, 255 (64%) were tested for hepatitis B surface antigen (HBsAg) and antibody (anti-) to the hepatitis C virus (HCV); 87 (34%) patients were positive for HBsAg but were negative for anti-HCV (hepatitis B virus [HBV] group), 126 (49%) were negative for HBsAg but were positive for anti-HCV (HCV group), 10 (4%) were positive for both and 32 (13%) were negative for both (non-B non-C group). RESULTS: By the end of March 1993, HCC was diagnosed in 127 (31.6%) patients. The cumulative risk of HCC in the HCV group was slightly higher than that in HBV group (P = 0.3, 5-year risk: 36.9 versus 21.2%). In contrast, the rate was significantly lower in the non-B non-C group than in the HBV or HCV groups (P < 0.05 and P < 0.01, respectively, 5 year risk: 12.4%). CONCLUSIONS: These results suggest that not only HBV infection but also HCV infection increase the risk for HCC in patients with cirrhosis.

Adult↗
PubMed1994

Intramural adenocarcinoma of the uterus, arisen from adenomyosis uteri, showing unique histologic appearances. Report of two cases.

Two cases of uterine adenocarcinoma which grew mainly in myometrium and showed unique histologic appearances are reported. Both cases were considered to have arisen from adenomyosis uteri because transitional figures were observed between carcinoma cells and adenmyotic glands in one case, and carcinomatous glands were scattered in myometrium and were associated with endometrial stroma which mimicked benign adenomyosis in another. The former case was poorly differentiated adenocarcinoma and the latter was well-differentiated adenocarcinoma. Interestingly, in the latter case, the carcinoma cells were transformed into papillary adenocarcinoma such as has been observed in the thyroid gland, and formed well-demarcated nodular mass. These findings indicate that adenocarcinoma which arise from adenomyosis uteri could show various histologic appearances, in addition to usual endometrioid adenocarcinoma.

Adenocarcinoma↗
PubMed1994

Gallbladder visualization on CT shortly after angiography with ioxaglate.

Thirty-five patients underwent CT examination 15 to 30 min after abdominal angiography with ioxaglate. The gallbladder was visualized in 12 patients in the absence of clinical evidence of renal impairment. Gallbladder opacification on CT examinations shortly after angiography shows that the hepatobiliary tract is important in the excretion of ioxaglate.

Adult↗
PubMed1992

Negative regulation of hepatocyte growth factor gene expression in human lung fibroblasts and leukemic cells by transforming growth factor-beta 1 and glucocorticoids.

Hepatocyte growth factor (HGF), a mesenchymal-derived factor which regulates growth, motility, and morphogenesis of epithelial and endothelial cells, functions as a hepatotrophic and renotrophic factor for regeneration of the liver and kidney. We have now obtained evidence that transforming growth factor-beta 1 (TGF-beta 1) and glucocorticoids are negative regulators for HGF gene expression. When TGF-beta 1 or dexamethasone was added to cultures of MRC-5 human embryonic lung fibroblasts and HL-60 human promyelocytic leukemic cells, the amount of HGF secreted into the culture medium was inhibited to 30-40% of that of control cultures by 10 ng/ml TGF-beta 1 and to 40-50% by 10(-6) M dexamethasone. The inhibitory effect of TGF-beta 1 and dexamethasone on HGF synthesis in MRC-5 cells was additive, thereby suggesting that TGF-beta 1 and dexamethasone exert effects through distinct mechanisms. Hydrocortisone also inhibited HGF synthesis with the same potency as dexamethasone; however, testosterone, estriol, and beta-estradiol had no effect. The rate of HGF synthesis in MRC-5 cells, as measured by pulse labeling with [35S]methionine and subsequent immunoprecipitation, was suppressed to 30-40% of the control with 10 ng/ml TGF-beta 1, and to 30-45% by 10(-6) M dexamethasone. HGF mRNA levels in MRC-5 cells and HL-60 cells were dose-dependently suppressed by TGF-beta 1 and dexamethasone; 10 ng/ml TGF-beta 1 suppressed HGF mRNA levels to 32% and 35% of control culture, respectively, in MRC-5 cells and HL-60 cells, and 10(-6) M dexamethasone suppressed to 43% and 38%, respectively. Thus, TGF-beta 1 and glucocorticoids seem to inhibit HGF synthesis by suppressing the expression of the HGF gene. We propose that a negative regulation of HGF gene expression by TGF-beta 1 or glucocorticoids may be involved in physiological or pathological processes during tissue regeneration.

Animals↗
PubMed1992

Identification and characterization of "injurin," an inducer of expression of the gene for hepatocyte growth factor.

The marked and rapid increase of hepatocyte growth factor (HGF) mRNA in the intact lung of rats after partial hepatectomy or unilateral nephrectomy suggests the existence of a humoral factor mediating a signal of injury to distal organs and may induce the expression of HGF gene in these organs. We have now identified a proteinous factor in the sera of rats with injury of liver or kidney that increases HGF mRNA in the intact lung. When the serum of rats with liver insult caused by partial hepatectomy or ischemic treatment was injected i.p. into normal noninjured rats, it induced a marked HGF mRNA expression in the lung of the recipient rats. The addition of serum from rats with various hepatic or renal injuries to MRC-5 human embryonic lung fibroblasts in culture also led to the induction of HGF mRNA expression, so that the production of HGF by MRC-5 cells after treatment with the sera was remarkably increased in the culture medium. However, serum from the normal intact rat induced no HGF production and no HGF mRNA in the lung in vivo and lung fibroblasts in vitro. This factor, which increases HGF production, was purified greater than 200-fold from sera of CCl4-treated rats. The factor proved to be an acid- and heat-stable protein with an apparent molecular mass of 10-20 kDa in SDS/PAGE. Its activity markedly increased within 3-6 hr in the plasma of rats after various treatments that injured the liver or kidney. These results suggest that the factor specifically appears in the blood of rats with organ injury and may be involved in organ regeneration through the potential to increase the synthesis of HGF. Since the factor seems to mediate various organ injuries, we named it "injurin."

Animals↗
PubMed1992

Regulation of cell growth and motility by hepatocyte growth factor and receptor expression in various cell species.

Hepatocyte growth factor (HGF), a humoral mediator for regeneration of liver and kidney, possesses multiple biological activities. To investigate target cell specificity and to examine whether multiple actions of HGF are related to properties of the HGF receptor on target cells, we examined the effects of HGF on cell growth and motility and analyzed the HGF receptor in various species of cells. HGF stimulated growth and DNA synthesis of PAM212 (naturally immortalized mouse keratinocytes), Mv1Lu (mink lung epithelia), and A431 (human epidermoid carcinoma) cells, as well as mature hepatocytes, but inhibited those of IM-9 (human B-lymphoblasts). Conversely, HGF had a marked stimulatory effect on cell motility of MDCK (Mardin-Darby canine kidney epithelia) cells, but not on their growth. Also, HGF enhanced the motility of various species of cells, including A431, PAM212, HepG2 (human hepatoma), KB (human epidermoid carcinoma), and J-111 (human monocytes) cells. Scatchard analysis of 125I-HGF binding to hepatocytes indicated that the cells expressed both high- and low-affinity binding sites for HGF with Kd values of 23 and 260 pM, respectively. High-affinity HGF receptor with Kd values of 20-25 pM was detected at 40-720 sites/cell in MDCK, A431, PAM212, Lu99, and IM-9 cells, but not in fibroblasts and hematopoietic cells. In contrast, low-affinity binding sites were detected in all cell lines examined, even in those not responsive to HGF. Northern blots revealed that cells possessing a high-affinity HGF receptor expressed c-MET/HGF receptor mRNA. Therefore, HGF probably regulates both cell growth and motility of various types of epithelial cells and some types of mesenchymal cells. The multiple biological activities of HGF may be exerted through a high-affinity HGF receptor linked to multiple distinct intracellular signaling pathways.

Animals↗
PubMed1992

Tissue distribution of hepatocyte growth factor receptor and its exclusive down-regulation in a regenerating organ after injury.

Using 125I-labeled hepatocyte growth factor (HGF) as a ligand, we examined the tissue distribution of the HGF receptor in adult rats. Specific binding of 125I-HGF was detected in the plasma membranes of liver, spleen, kidney, lung, adrenal gland, pituitary, and thyroid. Scatchard analysis of HGF binding in liver, spleen, kidney, lung, and adrenal gland revealed the presence of a single class of high affinity receptor with a dissociation constant (Kd) of 20-30 pM. The maximum number of binding sites (Bmax) was determined to be 400-3,000 sites per ng of plasma membrane protein, the highest number being in the liver. Such a wide distribution of a high affinity HGF receptor indicates that HGF may be a multifunctional growth factor, targeting to a variety of organs, and not restricted to liver. After 70% partial hepatectomy, specific binding of 125I-HGF to membranes of the residual liver rapidly decreased, but there was no change in the kidney, lung, and spleen. On the other hand, after unilateral nephrectomy rapid down-regulation of the HGF receptor was clearly evident in the remaining kidney, but not in other organs including the liver. These findings suggest the presence of control mechanisms governing HGF receptor function only in a regenerating organ after injury.

Animals↗
PubMed1992

[Elemental analysis of hilar and mediastinal lymph nodes in idiopathic pulmonary fibrosis].

Elemental analysis of hilar and mediastinal lymph node tissues was performed to determine whether some inhaled atmospheric elements are implicated in the pathogenesis of idiopathic pulmonary fibrosis (IPF). IPF was divided into two types; typical and atypical, according to our criteria. Lymph nodes were selected as the study material rather than lung tissue, because inhaled elements are concentrated in the hilar and mediastinal lymph nodes, and increase in lung weight due to fibrosis may influence the estimated values of element per unit weight of lung tissue. The hilar and mediastinal lymph nodes collected from 40 IPF cases and 43 non-IPF control cases were examined to determine the concentration of 13 elements in 100 mg dry tissue, using the X-ray fluorescent analysis method. For aluminium, 50 mg dry tissue was examined by an atomic absorption analysis method. Among the 14 elements, Ni in IPF lymph nodes showed a significantly higher level than in control nodes (mean +/- SD: 8.2 +/- 21.3 ppm versus 1.1 +/- 2.1 ppm, respectively. p < 0.01). No difference in each of the examined elements was noted between smokers and non-smokers or between typical and atypical IPF cases. Exogenous elements such as Ni may play a role as triggering substances in the pathogenesis of IPF.

Aged↗
PubMed1992

[Function, molecular structure and gene expression regulation of hepatocyte growth factor and its receptor].

Hepatocyte growth factor (HGF), a potent mitogen of mature hepatocytes in primary culture, is composed of 69 kDa alpha-chain with four kringle domains and 34 kDa beta-chain. HGF is currently thought to be a pleiotropic factor, that stimulates the growth and motility of various epithelial cells, and that inhibits the growth of some carcinoma cells. These cells have a single class of high affinity receptor with a dissociation constant (Kd) of 20-30 pM. The maximum number of binding sites (Bmax) was determined to be 100-1500 sites/cell. After 70% partial hepatectomy and unilateral nephrectomy, HGF activity in serum and their tissues increased markedly and HGF receptors of the injured organ rapidly decreased, but not in other normal organs. These results suggest that HGF acts only in a regenerating organ after injury through the control mechanisms governing HGF receptor.

Animals↗
PubMed1992

Aberrant left gastric vein directly draining into left portal venous system. A case report.

A 66-year-old man with early gastric cancer and liver cirrhosis was diagnosed by preoperative angiography as having an aberrant left gastric vein communicating directly with the left lateral portal vein system. This communication was confirmed during operation for the gastric cancer. Our report is the first of an aberrant left gastric vein showing direct communication with the left portal vein system.

Aged↗
PubMed1992

[Serial MRI findings in neuro-Behçet disease].

Behçet disease is a systemic disorder characterised by the triad of recurrent aphthous ulcers of the mouth, genital ulcers and uveitis. Neurological involvement is estimated at 10-25% in Behçet disease (neuro-Behçet). These include diplopia, pseudobulbar palsy, cranial nerve palsies, cerebeller ataxia, and cerebral and spinal sensory and motor disturbances. A case of neuro-Behçet disease is reported. A 51-year-old man was admitted with TIA attack. He had been suffering from recurrent oral and genital ulcers for several months before admission. Neurological examination on admission revealed poor mental activity, left facial nerve palsy and left hemiparesis. Lumbar puncture showed CSF pleocytosis. CT and MRI revealed multiple lesions in the cerebral hemisphere and the brain stem. CT showed spotty high density areas with perifocal low density areas in the frontal, temporal and parietal lobe which were enhanced with contrast materials. T1 weighted image of MRI revealed iso intensity areas with perifocal low intensity areas which were enhanced with Gd-DTPA in the frontal, temporal and parietal lobes. T2 weighted image revealed low intensity areas with perifocal high intensity areas in the same regions shown in the T1 weighted image. Moreover ring-like enhanced lesions with Gd-DTPA were revealed in the brain stem and corona radiata in the T1 weighted image. After high dose steroid treatment, he showed marked clinical improvement. CSF pleocytosis was normalized and the lesions were gradually reduced in size and were no longer enhanced with Gd-DTPA. MRI findings are well correlated with clinical features.(ABSTRACT TRUNCATED AT 250 WORDS)

Behcet Syndrome↗
PubMed1991

Renotropic functions of hepatocyte growth factor in renal regeneration after unilateral nephrectomy.

Hepatocyte growth factor (HGF), a most potent growth factor for mature hepatocytes may act as a trigger for liver regeneration. We reported that HGF strongly stimulates DNA synthesis of rabbit renal tubular cells in secondary culture (Igawa, T., Kanda, S., Kanetake, H., Saitoh, Y., Ichihara, A., Tomita, Y., and Nakamura, T. (1991) Biochem. Biophys. Res. Commun. 174, 831-838). To investigate whether or not HGF is involved in renal regeneration, we examined changes in HGF mRNA, HGF activity, and HGF receptor in the rat kidney following unilateral nephrectomy or treatment with carbon tetrachloride (CCl4). In the intact kidney, the HGF mRNA increased markedly reaching a maximum 6 h after unilateral nephrectomy, followed by an increase of HGF activity at 12 h after the surgery. The marked increase in HGF mRNA and HGF activity was also found in the kidney of rats treated with CCl4. Results of in situ hybridization suggested that cells producing HGF in the kidney are endothelial cells. The number of HGF receptors on renal plasma membranes decreased to 30% of the normal value 12 h after unilateral nephrectomy, with no change in the Kd value. The HGF receptor was greatly diminished 24 h after the operation, and recovery to 60% of the normal level was evident 1 week after the operation. Because the decrease in HGF binding may result from internalization of the HGF receptor, the HGF may bind to its receptor in vivo and act as a mitogen for renal epithelial cells. HGF may function as a renotropic factor during renal regeneration after kidney injury.

Animals↗