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Biomedical subjects

K Iida

Publications and source records attributed to K Iida.

At least 217 records · Page 12Linked to original sources
PubMed1994

Abnormal accumulation of copper-metallothionein in the liver and kidney of Long-Evans rats with a cinnamon-like coat color (LEC rats).

We determined the copper (Cu) and metallothionein (MT) concentrations in the liver and kidney supernatants of Long-Evans rats with a cinnamon-like coat color (LEC rats), and also measured the Cu and MT levels in the serum of these rats. Seven-week-old rats had abnormally high levels of both substances in the liver. The levels in the liver supernatant were over 80- and 16-fold higher, respectively, in LEC rats than in normal 7-week-old Wistar rats. LEC rats suffering from acute hepatitis or hepatoma had a much higher level of hepatic MT, but the Cu level was higher only in the liver of those with hepatoma. The serum levels of Cu and MT in LEC rats with acute hepatitis were more than 10-fold higher than those in normal LEC rats. These levels were decreased in the rats with chronic hepatitis or hepatoma. In the liver of LEC rats with hepatoma, the area of hepatocellular carcinoma and of noncancerous liver showed over twice higher Cu and MT levels than the area of cholangiofibrosis. The Sephadex G-75 elution profile from the liver supernatant of a normal LEC rat showed that the peak of Cu closely corresponded to that of MT recognized with anti-MT antiserum. The levels of Cu and MT in the kidney supernatant of LEC rats with acute hepatitis were more than 25-fold higher than in that of normal LEC rats. However, there were no marked increases in the levels in the kidney supernatant of LEC rats with chronic hepatitis or hepatoma.

Animals↗
PubMed1994

Inhibitory effect of tuna peptide on endothelin production in cultured endothelial cells.

The effect of tuna muscle-derived angiotensin-converting enzyme (ACE) inhibitory peptide (tuna AI) on the production of potent contracting factor, endothelin-1 (ET), in the cultured bovine aorta endothelial cells (BAECs) has been investigated. ET production in the culture medium was measured by radioimmunoassay. BAECs spontaneously produced ET in a time-dependent manner for 4 to 24 h after incubation. Addition of tuna AI to the medium resulted in a time- and concentration-dependent decrease in the production of ET. The tuna AI-induced inhibition of ET production was blocked by B-3824 (bradykinin (BK) B2-receptor antagonist), NG-monomethyl-L-Arg and indomethacin, but not by angiotensin II receptor antagonist. While BK, sodium nitroprusside and platelet-derived growth factor (PDGF) significantly inhibited ET production, angiotensin II and interleukin-1 did not. Potent ACE inhibitory peptides among tuna AI analogues did not always inhibit ET production. The results suggest that tuna AI inhibits ET production at least in part via potentiation of PDGF expression in addition to potentiation of BK pathway.

Amino Acid Sequence↗
PubMed1994

Biosynthesis of erythromycin: origin of the methyl protons.

13C-Nuclear magnetic resonance (13C-NMR) spectroscopy has been used to locate deuterium atoms incorporated biosynthetically into erythromycin from [3-13CD3]- and [3-13C]sodium propionate and L-[13CD3]- and L-[13C]methionine in Saccharopolyspora erythraea JCM 4748. The alpha-shifts of deuterated methyl groups were clearly observed in broad-band deuterium and proton-decoupled 13C-NMR spectra. The seven propionate-derived methyl groups and the four methionine-derived methyl groups were shown to undergo no exchange of methyl protons during the biosynthesis of erythromycin.

Erythromycin↗
PubMed1994

Two cases of acute myocardial infarction associated with aplastic anemia during treatment with anabolic steroids.

Thrombosis is a rare complication in patients with aplastic anemia because of the presence of coincidental thrombocytopenia. We have recently treated two cases, a 61-year-old male and a 59-year-old female, with acute myocardial infarction associated with aplastic anemia. Although their platelet counts were lower than normal in spite of treatment with anabolic steroids for aplastic anemia, the coronary angiographic findings strongly suggested coronary thrombosis in both cases. Anabolic steroids, which have been commonly used for the treatment of aplastic anemia, are a possible risk factor for coronary thrombosis because they have an accelerating effect on thrombus formation. We report two very rare but clinically important cases.

Anabolic Agents↗
PubMed1994

Ventricular wall stress revisited. A keystone of cardiology.

Wall stress has been used as one of the parameters of myocardial mechanics. The present review focuses on recently developed data on ventricular wall stress, especially in relation to other newly developed areas in cardiology. In hypertensive hearts, there is a broad continuous spectrum in the structural and functional changes: those with low wall stress (inappropriate hypertrophy), those with normal wall stress (appropriate hypertrophy) and those with high wall stress (inadequate hypertrophy). Among them, the responses to neurohumoral stimuli are various, and their clinical features and courses also varied. These differences in wall stress among the different categories of hypertensive hearts may be caused by the variable influences of non-mechanical factors, such as molecular, metabolic and neurohumoral ones. Wall stress is an essential determinant of myocardial oxygen consumption, and is also an important determinant of the myocardial contractile state and diastolic function. In contrast to excitation-contraction coupling, contraction-excitation feedback has been studied, suggesting the importance of wall stress regulating electrical phenomena. The interrelationship between mechanical factors (including wall stress) and non-mechanical factors (including molecular, metabolic, neurohumoral and genetic ones) has been investigated intensively. In conclusion, wall stress (or force on the myocardial cell) may be a keystone in cardiology, relating to each of the cardiac phenomena. If wall stress deviates from the normal range, even with compensatory mechanisms, severe cardiac events occur. The compensatory mechanisms for wall stress may act as a risk factor on the heart, especially when the wall stress remains outside the normal range.

Electrocardiography↗
PubMed1994

Experimental in vivo and in vitro formation of type VI collagen periodic fibrils in chorionic villi of human placenta.

The distribution of type VI collagen in the chorionic villi of normal human term placenta was studied. Since 100 nm periodic fibrils (type VI collagen periodic fibrils) are known to form in the tendon, cornea and cultured fibroblasts by incubation with acidic ATP solution, we incubated the placental tissue with 20 mM ATP, fixed it with Karnovsky's fixative and examined under an electron microscope. Type VI collagen periodic fibrils widely occurred in the interstitial connective tissue, especially close to the basal lamina. By cryo-immunoelectron microscopy, labeling for collagen type VI was found in the area between the trophoblastic basal lamina and the endothelial basal lamina. Furthermore, we extracted type VI collagen from the human placenta and brought both extract and residues into ATP treatment. Periodic structure formation was rare in extracted preparation compared with residues. The results served to clarify the mechanism of fibril formation in the tissue.

Adenosine Triphosphate↗
PubMed1994

[A case of hemangioblastoma in the thalamus].

Supratentorial hemangioblastoma is encountered very rarely. About 80 cases in all have been reported. The authors present a case of supratentorial hemangioblastoma in the thalamus with gradually enlarging cysts. The patient was a 45-year-old man with complaints of left hemiparesis and headache. Computed tomographic scans of the brain showed a cystic mass with mural nodule in the right thalamus. Left vertebral angiography demonstrated a vascular tumor fed by a thalamogeniculate artery. A right temporo-parietal craniotomy was performed and the tumor was totally resected through the transcortical approach. The histological diagnosis was hemangioblastoma. Post-operative course was good except for a minor complication of the left lower quadrant homonymous hemianopsia and left hemiparesis which had disappeared at the time of discharge.

Hemangioblastoma↗
PubMed1994

[Oral complication of sublabial transsphenoidal approach and advantage of endonasal transsphenoidal approach].

In order to know the exact incidence of oral complications due to the sublabial transsphenoidal approach, the authors meticulously heard the complaints of 46 patients, who had undergone the approach more than 3 months before. The incidence of the patients who had one or more complaints concerning the oral region was 52.2%. Dysesthesia of the upper lip was most frequent (37%), followed by upper lip pain (17.4%). These complaints were more marked in two patients who had undergone operations using the sublabial approach twice. Among the nine patients with dentures, the dentures had to be remade in three patients because of gigival atrophy several months after the use of the sublabial approach. With a view to overcoming these complications, the authors adapted the endonasal transsphenoidal approach in 13 patients. There was no inconvenience during surgery while this approach was being used, and there were no postoperative oral complications. Among three patients using dentures, there were none who needed remodeling of their dentures. In nine patients, the tension reducing incision was made in the bottom of the columella, which caused no cosmetic problem. Furthermore, the time consumed for approaching the sphenoid sinus was less than that required when using the sublabial approach. In conclusion, the following type of patient is believed to be an appropriate candidate for endonasal approach. A patient who has a relatively smaller sellar lesion and 1) An acromegalic patient whose nostril is relatively large, 2) An elderly patient using dentures, 3) A patient who has undergone previous transsphenoidal surgery, or 4) A patient whose columellar crease is hidden.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗
PubMed1994

[A case of brain abscess of the basal ganglia which resulted in disastrous outcome due to ventricular ruptures].

A case of deep-seated brain abscess that ruptured twice into the ventricle and resulted in death is presented. A 45-year-old man had experienced pyrexia and headache for 3 days before admission. On admission he was somnolent (GCS: 13) but there were no abnormal neurological findings except nuchal rigidity and Kernig's sign. Computed tomography (CT) scan showed a ring enhanced mass near the left caudate head and dilated ventricles. In comparison with CT performed at the former hospital it was diagnosed that a rupture into the ventricle of the brain abscess had occurred. Ventricular drainage was performed at once and white purulent cerebrospinal fluid was obtained. Thereafter, he was treated with some antibiotics and his conditions seemed to stabilize for a while. Serial CT images demonstrated that the size of the abscess seemed to be enlarging. Just when we planned to undertake stereotactic aspiration, the second ventricular rupture occurred and he died. According to this case, it is suggested that once a deep-seated brain abscess near the ventricular system is suspected, it should be aspirated by means of CT-guided stereotactic surgery immediately.

Basal Ganglia Diseases↗
PubMed1994

[Characteristics of myocardial diseases in the elderly].

Myocardial diseases consist of cardiomyopathy of unknown origin and specific myocardial diseases of known origin. The former consists mainly of dilated cardiomyopathy (DCM) and hypertrophic cardiomyopathy (HCM). In the latter, cardiac amyloidosis may be most frequently seen in the elderly. One hundred and twenty patients with cardiomyopathy were studied concerning their clinical courses. They were divided into 2 groups; i) young-middle-aged (Y) and ii) elderly (0). Group 1 was divided into 2 subgroups: 1a) followed up to an age less than 60 years old, and 1b) followed up to beyond age 60. In DCM, left ventricular posterior wall thickness and left atrial diameter increased significantly in the elderly. In HCM, young patients had obstructive type disease more frequently than the elderly. A history of mild hypertension was found more frequently in the middle-aged or elderly than in the young. Left ventricular end-diastolic diameter increased and left ventricular wall thickness decreased significantly in the elderly. Many patients with DCM usually die of congestive heart failure with ventricular arrhythmia, and those with HCM, both young or middle-aged, often die suddenly during sports activity. If there is an adaptive system, such as increased wall thickness in DCM or decreased wall thickness and increased diameter in HCM, which may contribute to the normalization of left ventricular wall stress, the patients might be able to survive to old age.

Adult↗
PubMed1993

Rapid and sensitive method for detection of Salmonella strains using a combination of polymerase chain reaction and reverse dot-blot hybridization.

We have developed a reverse dot-blot hybridization assay for detection of Salmonella using Salmonella-specific oligonucleotide probes designed from the base sequence of the 16S rRNA gene (rDNA). The target fragment of 16S rDNA was amplified, and labelled with biotin by the polymerase chain reaction. The amplified fragment was hybridized with the membrane-immobilized probe and the hybridization was detected by chemiluminescence. Amplified fragments from 24 different serovars of Salmonella hybridized with the probes, whereas those of species of Enterobacteriaceae, Pseudomonas aeruginosa, Bacillus subtilis, and Staphylococcus aureus failed to hybridize. By this assay, it was possible to detect in the order of 10(4) bacteria in fish meat homogenate in 10 h.

Base Sequence↗
PubMed1993

Cloning and site-directed mutagenesis of human ADP-ribosylarginine hydrolase.

Mono-ADP-ribosylation of arginine is a reversible modification of proteins with NAD:arginine ADP-ribosyltransferases and ADP-ribosylarginine hydrolases catalyzing the opposing reactions in the cycle. ADP-ribosylarginine hydrolases differ in their dithiothreitol (DTT) requirements. Rat and mouse hydrolases require DTT for maximal activity, but calf, guinea pig, and human hydrolases are DTT-independent. To define the molecular basis for these differences, brain ADP-ribosylarginine hydrolases were cloned. Deduced amino acid sequences of mouse and rat hydrolases were 94% identical with 5 conserved cysteines. The human hydrolase sequence was 83% identical to that of rat but contained only 4 cysteines with cysteine 108 in rat corresponding to serine 103 in human. To investigate the role of rat cysteine 108, human and rat wild-type hydrolases and mutants, in which serine 103 in human was replaced by cysteine (S103C) and cysteine 108 in rat was replaced by serine (C108S), were expressed in Escherichia coli. Affinity-purified anti-rat brain hydrolase antibodies reacted with recombinant wild-type rat hydrolase, but only weakly with the C108S mutant. They did not react with human wild-type or the S103C mutant. Human hydrolase and rat C108S were DTT-independent; human S103C was, however, DTT-dependent. These data clearly show that cysteine 108 in rat hydrolase plays a critical role in DTT dependence and may be important in immunoreactivity.

Amino Acid Sequence↗
PubMed1993

Distribution of 1,25-dihydroxyvitamin D3 receptor and 25-hydroxyvitamin D3-24-hydroxylase mRNA expression along rat nephron segments.

Distribution of mRNA expression of 1,25-dihydroxyvitamin D3 receptor (VDR) and 25-hydroxyvitamin D3-24-hydroxylase (24-OHase) along the microdissected rat nephron segments was examined by reverse transcription-polymerase chain reaction (RT-PCR) technique. VDR mRNA was abundantly expressed in cortical segments (glomeruli, proximal convoluted tubule, proximal straight tubule, cortical thick ascending limb, distal convoluted tubule and cortical collecting duct), and it was also detected in outer medullary segments (medullary thick ascending limb, outer medullary collecting duct). Messenger RNA of 24-OHase was abundant in proximal convoluted tubule, and it was also present in proximal straight tubule, but not in other segments. The results demonstrate that in contrast to the expression of 24-OHase mRNA which is limited to the segments where the activity of this enzyme has been demonstrated, the expression of VDR mRNA is ubiquitous along the nephron segments.

Animals↗
PubMed1993

Isolation of a yeast essential gene, COF1, that encodes a homologue of mammalian cofilin, a low-M(r) actin-binding and depolymerizing protein.

We have cloned a Saccharomyces cerevisiae gene (COF1) encoding a low-M(r) actin-binding protein of 143 amino acid (aa) residues (yeast cofilin; Cof); its aa sequence is 35% identical to porcine Cof. The yeast recombinant Cof produced in Escherichia coli exhibited in vitro activities on actin filaments similar to those of mammalian and avian Cof. Gene disruption and tetrad analysis showed that gene COF1 is essential for yeast cell growth. Expression of the cDNA of porcine Cof or destrin (Des), the latter a Cof-related protein, complemented the cof1 null allele in yeast cells.

Actin Depolymerizing Factors↗
PubMed1993

Cells lacking glycan phosphatidylinositol-linked proteins have impaired ability to vesiculate.

Erythrocytes shed membrane vesicles in response to many stimuli. It has been previously demonstrated that glycan phosphatidylinositol-linked (GPI-linked) proteins such as decay accelerating factor and acetylcholinesterase are concentrated in these vesicles relative to the erythrocyte membrane. We have examined the requirement for GPI-linked proteins for the process of vesiculation. Erythrocytes that do not express GPI-linked proteins, obtained from patients with paroxysmal nocturnal hemoglobinuria (PNH), release between 10% and 50% of the quantity of vesicles as normal cells in response to the Ca2+ ionophore A23187. Platelets from the same patients produced 10% to 20% of the amount of vesicles as normal platelets. In addition, a mutant B-lymphoblastoid cell line that lacks GPI-linked molecules produces about half of the number of vesicles as compared with the wild-type cell line in response to the Ca2+ ionophore. Prior findings indicate that vesiculation is one of the mechanisms that the cell uses to remodel the plasma membrane, as well as protect itself from membrane-damaging agents such as the terminal complement components C5b-9. On the basis of the present results, we conclude that GPI-linked proteins play an important role in membrane vesiculation.

Acetylcholinesterase↗
PubMed1993

Studies on thermophile products. VI. Activation of mouse peritoneal macrophages by bis(2-hydroxyethyl) trisulfide.

The biological effects of a cytotoxic substance (BS-1), isolated from Bacillus stearothermophilus UK563 and identified as bis(2-hydroxyethyl) trisulfide, on elicited mouse peritoneal macrophages induced by a casein injection, were investigated in vitro. BALB/c mouse macrophages treated or pretreated with BS-1 (1-10 micrograms/ml) showed cytotoxicity against syngeneic DBA/2 mouse P815 mastocytoma. BS-1 also showed weak cytotoxicity directly against P815 in the absence of macrophages. BS-1 significantly increased the glucose consumption of macrophages without producing cytotoxicity. This trisulfide compound increased nitric oxide formation, interleukin-1 production and prostaglandin E2 release in macrophages. It did not, however, increase the production of active oxygen species in macrophages, but it reduced cytochrome c in the presence of phagocytes. These results indicate that BS-1 activates macrophages to the cytolytic stage.

Animals↗
PubMed1993

[Myocardial ischemia detected by isoproterenol stress cardiac blood-pool scintigraphy: significance of asynchrony as an index of myocardial ischemia].

It is well known that left ventricular regional contraction abnormality (hypokinesis: hypo) occurs during myocardial ischemia. However, it is uncertain whether left ventricular asynchronous contraction (asynchrony) is an index of myocardial ischemia. To validate asynchrony as an index of myocardial ischemia, isoproterenol infusion stress (ISP) cardiac blood-pool scintigraphy (RI angiography) was performed in patients with ischemic heart disease. The subjects were classified into 2 groups: 1) 15 patients with coronary artery disease (CAD) and 2) 8 patients with "normal" coronary arteries (NC). None had any electrical ventricular conduction disturbance. ISP was administered with increasing doses of 0.02, 0.04, 0.08 microgram/kg/min at 3-min intervals, and it was terminated in the event of angina, significant ST changes or target heart rate. Symptom-limited ergometer exercise testing (EX) was also administered in 14 patients. Regional decrease in amplitude and phase delay identified by phase analysis was diagnosed as hypo and asynchrony, respectively. ISP myocardial scintigraphy was also performed in 15 patients. Results were as follows: ISP and EX induced asynchrony in 14 (93%) and 13 patients (93%), respectively, while, did hypo in 4 (27%) and 9 (64%), respectively. Ten (67%) of 15 patients had asynchrony without hypo in ISP; whereas, only 4 (28%) of 14 patients did in EX. ISP-induced asynchrony occurred in one of 8 patients with NC. The locations of ISP-induced asynchrony and those of EX-induced asynchrony were concordant in 11 (79%) of 14 patients. Asynchrony on the ISP RI angiogram was observed at the same sites of redistribution on the ISP myocardial scintigram. We concluded that asynchrony itself is a sensitive and specific index of myocardial ischemia.

Adult↗