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Biomedical subjects

I Fukuda

Publications and source records attributed to I Fukuda.

At least 19 recordsLinked to original sources

Dynamical behavior of psb gene transcripts in greening wheat seedlings. I. Time course of accumulation of the pshA through psbN gene transcripts during light-induced greening.

The time course of the accumulation of the transcripts from 13 psb genes encoding a major part of the proteins composing photosystem II during light-induced greening of dark-grown wheat seedlings was examined focusing on early stages of plastid development (0.5 h through 72 h). The 13 genes can be divided into three groups. (1) The psbA gene is transcribed as a single transcript of 1.3 kb in the dark-grown seedlings, but its level increases 5- to 7-fold in response to light due to selective increase in RNA stability as well as in transcription activity. (2) The psbE-F-L-J operon, psbM and psbN genes are transcribed as a single transcript of 1.1 kb, two transcripts of 0.5 and 0.7 kb and a single transcript of 0.3 kb, respectively, in the dark-grown seedlings. The levels of accumulation of every transcript remain unchanged or rather decrease during plastid development under illumination. (3) The psbK-I-D-C gene cluster and psbB-H operon exhibit fairly complicated northern hybridization patterns during the greening process. When a psbC or psbD gene probe was used for northern hybridization, five transcripts differing in length were detected in the etioplasts from 5-day old dark-grown seedlings. After 2 h illumination, two new transcripts of different length appeared. Light induction of new transcripts was also observed in the psbB-H operon.

Blotting, Northern

Clastogenicity of low pH to various cultured mammalian cells.

It has been reported that low pH itself can be clastogenic to Chinese hamster ovary cells or mouse lymphoma L5178Y cells. On the other hand, there was no indication that low pH is clastogenic to rat or human lymphocytes. Therefore, in order to evaluate the generality of clastogenicity of low pH conditions, chromosomal aberration tests were carried out on Chinese hamster cell line cells (CHO-K1, CHL, Don and V79 379A) and human cells (HeLa and peripheral lymphocytes used as whole-blood cultures). The cytotoxicity of low pH to each cell line was also evaluated by counting surviving cells. The treatment medium used was Eagle's MEM containing 15 mM MES or Bis-Tris as an organic buffer to maintain the acidity of the medium for the 6-h or 24-h treatment period, and pH adjustment was done with NaOH or HCl. Chromosomal aberrations were induced at pH 6.5 or below in CHO or CHL cells, and the maximum frequency was 24.7% at pH 6.0 or 34% at pH 6.3, respectively. About 5-10% of Don or HeLa cells had aberrations over the range of pH 6.6-6.0 or pH 6.6-6.3, respectively. In V79 379A cells or human lymphocytes, however, aberrant cells amounted to about 8% at near pH 6.0, where cell survival was low (less than 20%). About 90% of aberrations induced in each cell line examined were chromatid-type gaps and breaks. When CHO or CHL cells were treated with acidic medium for 6 h plus 18 h recovery in fresh medium, about 20% of cells had aberrations including chromatid exchanges at pH 5.5 or pH 5.7, respectively. These results indicate that clastogenicity of low pH is a general finding, although the extent of it varies with cell type, and that the clastogenicity is associated with varying extents of cytotoxicity. The mechanisms of clastogenesis at low pH are not known, but might involve inhibition of DNA or protein synthesis or DNA-repair enzymes.

Animals

Identification and characterization of virK, a virulence-associated large plasmid gene essential for intercellular spreading of Shigella flexneri.

Seven virulence loci have been identified by Tn5 insertion mutagenesis on the large 230 kb plasmid (pMYSH6000) of Shigella flexneri 2a. In this study, we used Tn10 insertion mutagenesis and identified a novel virulence locus on pMYSH6000 responsible for bacterial spread. Characterization of the invading bacteria of the Tn10 insertion mutants in the epithelial cells revealed that the bacteria were capable of at least some intracellular spreading but not intercellular spreading. Immunoblot analysis of lysates of the Tn10 insertion mutants with a VirG-specific antipeptide antibody revealed diminished levels of the 116 kDa VirG protein. The virG mRNA in the mutants, however, was expressed at the same level as that in the wild type. The DNA region required for the virulence phenotype was localized to a 1.6 kb DNA sequence in the SalI-K fragment on the plasmid, and thus the locus was designated virK. Expression of virK in Escherichia coli using a T7 RNA polymerase-dependent promoter system yielded a 36 kDa protein. The nucleotide sequence of 1642 bp encoding VirK function was determined, and an open reading frame encoding 316 amino acid residues was shown to encode the VirK protein. The virK region was highly conserved among the large virulence plasmids of shigellae and enteroinvasive Escherichia coli. These results suggest that VirK function is an essential virulence determinant for shigellae involved in the expression of virG gene product at post-transcriptional level.

Amino Acid Sequence

Alternatively-spliced p53 mRNA in the FAA-HTC1 rat hepatoma cell line without the splice site mutations.

A novel mutation of the p53 gene has been found in a rat hepatoma cell line, FAA-HTC1. This cell line carried two kinds of abnormal p53 transcripts; one lacked the exon 8 sequence, and the other had a single base substitution G to T which resulted in a new stop codon in exon 8. In the genomic DNA, this base substitution in exon 8 was present, indicating that both transcripts were transcribed from the mutated gene. No mutation was detected in its two flanking introns. In this cell line, the exon-deleted transcript seems to be generated by exon skipping due to an unknown mechanism other than splice site mutations.

Animals

[Aortic root reconstruction in the patient with aortic root dissection and aortic valve regurgitation: a case report].

The reported patient was a 60-year-old man with congestive heart failure and recurrent inferior myocardial infarction. The aortogram revealed severe aortic regurgitation, aortic root dilatation and dissection with involvement of the right coronary ostium. Aortic root reconstruction using the valved conduit was performed. The left coronary ostium was reimplanted with Carrel patch method and the right coronary artery was bypassed with the saphenous vein graft. Postoperative course was uneventful and he is asymptomatic in one year after operation. Although aortic root reconstruction with Carrel patch procedure is not widely adopted in Japan, we recommend this procedure because the anastomosis between the coronary ostium and the graft is tight.

Aortic Dissection

[A sharp edge of the fractured ribs caused the aortic injury at body-position change: a case report].

The reported patient was a 37-year-old male, who got a blunt chest trauma by a motor vehicle accident. Chest X-ray and computed tomography of the chest revealed bilateral multiple rib-fractures, pneumo-hemothorax, lung contusions, but no evidence of mediastinal hematoma. Since respiratory distress with a flail chest was observed, the patient was placed on an artificial ventilation, and thoracocentesis were also done on both sides, while the hemodynamics was fairly maintained with blood transfusion. On the 10th hospital day, however, he suddenly fell into a deep shock with the left hemothorax by changing the body position. Emergency thoracotomy demonstrated the laceration of the descending aorta, that was considered to be made by the sharp edge of the fractured left 8th rib, which correspondingly protruded into the thoracic cavity toward the aorta. The repair of the aortic injury and the resection of the rib edges were performed. He was discharged on the 45th hospital day. In cases with a blunt chest trauma, the majority of the causes of the traumatic aortic injury are reported to be "deceleration injury". Although the considered mechanism of the traumatic rupture of the thoracic aorta in this case is extremely rare, it should be taken into a consideration for treatment of the cases with a blunt chest trauma and multiple rib-fractures.

Adult

[Preoperative hemodilution to reduce homologous blood transfusion--effects on hemodynamics and oxygen flux].

Many problems arise from homologous blood transfusion in operative patients. Preoperative collection of blood with hemodilution is a simple method to allow autologous blood transfusion. Sixty patients who received gynecological operations were divided into three groups. Patients in the first and second groups underwent preoperative blood collection and hemodilution, and collected blood was transfused during operation when bleeding volume had exceeded prefixed value. The volume and speed of blood collection were 20 ml.kg-1 and 30 minutes in the first group, and 20 ml.kg-1 and 15 minutes in the second group. After the collection of blood, HES solution was infused to maintain blood volume. The patients in the third group were transfused with homologous blood as controls. The blood pressure, heart rate, cardiac index and oxygen flux were maintained well in the first group after collection of blood and hemodilution. The hemoglobin concentration was kept at 10 g.dl-1 when the operation was terminated with a mean bleeding volume of 1,014 ml. The results suggest that the method of preoperative blood collection and hemodilution followed by autologous blood transfusion is a promising technic to reduce the amount of homologous blood transfusion in operative patients.

Blood Transfusion, Autologous

[Surgical results of two cases of simultaneous surgery of carotid and coronary occlusive disease].

Two cases of symptomatic extracranial carotid artery stenosis associated with ischemic heart disease are reported. The first case was 72-year-old male, who was admitted because of transient ischemic attack due to the stenosis of left internal carotid artery. He had a history of myocardial infarction and coronary angiography revealed three vessel disease. The second case was 74-year-old female with diabetes mellitus. She was admitted because of cerebral infarction. The carotid angiography revealed critical stenosis of bilateral internal carotid arteries. Her coronary angiography revealed three vessel disease. Her chest symptom became unstable after her admission. In both cases, simultaneous carotid endarterectomy and coronary bypass grafting were performed with successful outcome. In the patients with symptomatic extracranial carotid occlusive disease associated with severe ischemic heart diseases, we advocate simultaneous operation both for carotid and coronary artery occlusive disease.

Aged

Single sc administration of insulin-like growth factor I (IGF-I) in normal men.

Total and free form of IGF-I in plasma increased in a dose dependent manner after sc IGF-I administration. Peak values of total IGF-I were obtained at 3-4 h after the administration, and then the values decreased gradually. However, peak values of free form of IGF-I were obtained at 2 h, and then rapidly decreased thereafter. The blood glucose, serum insulin and C-peptide levels decreased until 4 h after IGF-I administration in a dose dependent manner. Plasma IGF-II values significantly decreased at 4-12 h after IGF-I administration. Urinary urea nitrogen and sodium excretion decreased after IGF-I administration. Urinary GH excretion also decreased after 0.06 mg/kg IGF-I administration. These data demonstrate that IGF-I may play a role in glucose, protein and electrolyte metabolism, and plasma IGF-II levels and GH secretion might be regulated by IGF-I in man.

Adult

Effect of pH on the activity and stability of clastogens in the in vitro chromosomal aberration test with Chinese hamster ovary K1 cells.

The effect of the pH of the medium on the clastogenic activity of several direct-acting and indirect clastogens was evaluated in the in vitro chromosomal aberration test with Chinese hamster ovary K1 cells. Furthermore, the stability of the chemicals in the cell culture medium was measured by HPLC over the pH range of 5.0-11.0. The activity of the direct-acting clastogens mitomycin C (MMC), N-ethyl-N'-nitro-N-nitrosoguanidine (ENNG) and 4-nitroquinoline-1-oxide (4NQO) at various pH values depended on their stability. In the case of ENNG, its clastogenic activity decreased to about one-fifth at pH 9 but was about twice as high at acidic pH compared with that at pH 7.4. This is consistent with the observation that ENNG is unstable at basic pH; the residual content of ENNG was 0.5% of the initial amount in cell culture medium at pH 9.0 after a 2-h incubation. 4NQO was unstable at strongly basic pH (pH 10-11), and MMC was unstable at pH 5.0 and pH 11.0. The frequencies of chromosomal aberrations induced by MMC and ENNG were correspondingly decreased at these pH values. On the other hand, the clastogenicities of the indirect clastogens 7,12-dimethylbenz[a]anthracene (DMBA), benzo[a]pyrene (B(a)P) and dimethylnitrosamine (DMN), which require metabolic activation, were reduced at pH 10-11 and pH 5.8. The frequencies of chromosomal aberrations at these pHs were almost equal to negative control values. These chemicals were stable in the medium in the absence of S9 mix over the pH range of 5.0-11.0. Thus clastogenicity of indirect-acting clastogens is reduced under extreme pH conditions, probably because of the instability or nonformation of the active form. The present results indicate that the clastogenic activity of any compound will depend on its stability in the medium irrespective of its direct- or indirect-acting nature. In addition, some of the chemicals that are recognized as clastogens presumably might induce chromosomal aberrations by means of acidic pH itself. It is, therefore, important to take account of the pH of the treatment medium in evaluating the clastogenicity of chemicals.

4-Nitroquinoline-1-oxide

[The assessment of preoperative transcatheter arterial embolization (TAE) for hepatocellular carcinoma (HCC)--the comparison between "whole-liver" TAE and "lobar or segmental" TAE].

In 180 patients with hepatocellular carcinoma (HCC) who underwent radical hepatectomy, 52 patients were received preoperative arterial chemoembolization (TAE) for the whole liver (whole-liver TAE group: group A), 39 for the limited area of the liver (lobar or segmental TAE group: group B) and the remaining 89 had no treatments before surgery (control group: group C). In order to evaluate the significance of preoperative TAE, long-term prognoses were compared among the three groups. Although there were no significant differences in survivals between A and C, the 2- and 6-year survivals in group B were significantly better than those in group C (P less than 0.05). With regard to reduction rates of tumors and necrotizing effect for daughter nodules after TAE, the lobar or segmental TAE was significantly superior to the whole-liver TAE. Moreover, the lobar or segmental TAE deteriorated the liver function significantly less than the whole-liver TAE. These findings suggest that the lobar or segmental TAE is more advantageous than the whole-liver TAE as a preoperative adjuvant therapy.

Carcinoma, Hepatocellular

Measurement of free form of insulin-like growth factor I in human plasma.

A method to measure free form of insulin-like growth factor I (IGF-I) in human plasma using octadecylsilyl silica (Sep-Pak C18) cartridge has been developed. IGF-I was adsorbed by Sep-Pak C18 cartridge and eluted with 75% ethanol--0.01 M HCl. Labeled and non-labeled IGF-I were recovered in yields 92.5 +/- 2.1% (Mean +/- SEM) and 94.4 +/- 6.3% after adsorption to and elution from the Sep-Pak, respectively. When EDTA plasma was applied to the Sep-Pak, less than 5% of total IGF-I was recovered in the eluate. However, when acid-ethanol extracted plasma was applied to the Sep-Pak, IGF-I was recovered in yields greater than 75% of total IGF-I. When the Sep-Pak eluate was gel filtered, 88.4 +/- 4.0% of immunoreactive IGF-I eluted in the same fraction as synthetic IGF-I did, but the fraction passed through the Sep-Pak was observed as a high molecular weight form (bound form) of IGF-I. These data indicate that this Sep-Pak method does not extract all of the IGF-I in plasma, but extracts mainly the free form IGF-I. Using this method, IGF-I values of free form (fIGF-I) in EDTA plasma were measured. The fIGF-I values in normal adults, patients with acromegaly, and patients with growth hormone (GH)-deficiency were 2.4 +/- 0.1, 13.8 +/- 1.6, and 1.1 +/- 0.1 ng/ml, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Acromegaly

Repeated sc administration of recombinant human insulin-like growth factor I (IGF-I) to human subjects for 7 days.

Recombinant human insulin-like growth factor I (rhIGF-I) was administered subcutaneously to 6 normal subjects and 2 patients with GH deficiency at a dose of 0.1 mg/kg for 7 consecutive days after breakfast. In normal subjects, plasma IGF-I levels increased from 217 +/- 22 ng/ml (Mean +/- SEM) to maximal levels of 581 +/- 6 ng/ml 4 h after the first administration of IGF-I. The blood glucose levels were statistically depressed 4 h after injection at 69 +/- 2 mg/dl. Similar plasma IGF-I and blood glucose profiles were observed after the seventh administration of IGF-I. The free form of IGF-I in plasma was 2.3 +/- 0.3 ng/ml in normal subjects and increased to maximal levels of 43.5 +/- 5.1 ng/ml 2 h after the first IGF-I administration. A similar pattern for the free form of IGF-I was observed after the seventh administration; however, the values obtained at 0, 1 and 2 h were greater after the seventh administration. In patients with G-deficiency, the plasma IGF-I and blood glucose profiles were similar to those observed in normal subjects, although the total IGF-I levels were low in these patients at all sampling points during the study. Slight decreases in serum insulin, uric acid, and creatinine were observed after the seventh administration of IGF-I. There were no changes in the excretion of urea nitrogen, creatine, creatinine, sodium, potassium, chlorine, calcium or C-peptide in the urine during the 7 days of IGF-I administration.

Adult

Successful surgical management of pulmonary and adrenal metastases from hepatocellular carcinoma.

This article reports a rare case of successful surgery for both lung and adrenal metastases after hepatic resection of hepatocellular carcinoma (HCC). A 55-year-old Japanese man with a 5-year history of chronic liver disease was admitted with an elevated serum alpha-fetoprotein (AFP) value and a liver tumour detected by ultrasonography. Hepatic angiogram showed a tumour stain with the right hepatic vein as a venous drain from the tumour. He underwent posterior-inferior subsegmentectomy of the right hepatic lobe following preoperative chemoembolization. Sixteen months after the first operation, he received pulmonary resection for a solitary metastasis in the right lung. A further 10 months later, a metastatic tumour was detected in the left adrenal gland without any recurrent or metastatic foci, and he underwent left adrenalectomy as his third operation. He is still alive, 8 months after his last operation, and 34 months after hepatic resection, with a normal value of AFP and without any recurrent or metastatic foci. This may be the first report of a patient who underwent successful surgery for pulmonary and adrenal metastases of HCC.

Adrenal Gland Neoplasms

[Prevention of local recurrence after sphincter-saving resection for rectal cancer].

The main cause of local recurrence after curative operation for rectal cancer is intra-operative implantation of viable shed cancer cells. The present study was undertaken to investigate whether irrigation of remnant rectum prior to anastomosis would prevent local recurrence in rectal cancer. Remnant rectum was irrigated 20 times with physiologic saline using 30 ml enema syringe. One hundred thirty-five patients with rectal cancer underwent sphincter-saving resection for cure. Twenty-six of these patients, received irrigation with physiologic saline, and the remainder received no irrigation. Viable cancer cells were still present in remnant rectum after irrigation 10 times, but absent after 20 times. Distribution by age, sex, stage and the distal clearance margin was similar in both groups. Local recurrence occurred in none of the irrigation-treated patients and in 11 percent of the untreated ones (p less than 0.05). Our results indicate that irrigation 20 times with 30 ml of physiologic saline of the remnant rectum prior to anastomosis is an effective method of preventing local recurrence after resection of rectal cancer.

Adult

[Hepatic arterial infusion chemotherapy and loco-regional treatment and irradiation of pancreas tumor in non-resectable pancreas cancer with liver metastases].

This study seeks to evaluate arterial infusion chemotherapy and radiotherapy for non-resectable pancreatic cancer with liver metastases. Arterial infusion to the liver was performed in 24 patients, 15 of whom received arterial infusion to the pancreas and 9 of whom underwent irradiation for pancreas tumor (40-50 Gy). However, arterial infusion to the liver alone did not prolong survival, but loco-lesional therapy for the pancreas tumor improved quality of life and resulted in good local control. The survival of the two treatment groups (arterial infusion to the liver combined with loco-regional treatment to the pancreas versus systemic chemotherapy) was statistically different (median 7 months versus 3 months, p less than 0.01). Arterial infusion to the pancreas decreased liver metastases as the first site of failure. These results suggested that arterial infusion to both liver and pancreas combined with irradiation for the pancreas tumor are effective in increasing survival time and improving the quality of life.

Administration, Oral