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Biomedical subjects

T Ohara

Publications and source records attributed to T Ohara.

At least 163 records · Page 9Linked to original sources
PubMed1990

[A simple method of extracorporeal membrane oxygenation (ECMO)--3. The effects of pumpless ECMO (arterio-venous shunt) on arterial blood gas measured for 24 hours].

In eight anesthetized mongrel dogs, the pumpless ECMO applied between the femoral artery and vein was performed under the condition of hypoventilation for 24 hours. The methods were same as the first and second reports, except the pumpless ECMO was used. The abnormal parameters in the cardiovascular and respiratory system (blood gas analysis and end expiratory gas analysis), induced by hypoventilation, recovered to almost normal ranges, by operation of the pumpless ECMO for 24 hours. The pumpless ECMO might have such advantages over ECMO with pump as the less destruction of blood cell, easy performance and simple apparatus. In conclusion, pumpless ECMO using arterio-venous shunt may be applied clinically on respiratory distress conditions.

Animals↗
PubMed1990

Fibronectin receptor on polymorphonuclear leukocytes in families of Ehlers-Danlos syndrome and other hereditary connective tissue diseases.

Studies were made on the fibronectin receptor on polymorphonuclear leukocytes of patients with hereditary connective tissue diseases and of healthy members of their families. In four patients with Ehlers-Danlos syndrome type II (family E) and type VI (family M), the maximum number of binding sites (Bmax) of fibronectin receptor was significantly decreased to 2.2 to 2.9 x 10(3) sites/cell (normal range 6.3 +/- 1.5 x 10(3) sites/cell). The Bmax values of healthy members of their families were normal or moderately decreased to 3.8 to 5.1 x 10(3) sites/cell. In a patient with osteogenesis imperfecta type III (family K) the Bmax was significantly decreased to 1.1 x 10(3) sites/cell, but healthy members of his family had normal Bmax values. In a patient with Marfan syndrome (family A) the Bmax was decreased to 4.3 x 10(3) sites/cell. The dissociation constant of the fibronectin receptor was normal in all subjects examined. Some healthy members of the families of the patients with Ehlers-Danlos syndrome had moderately decreased Bmax values, suggesting that they are carriers of an abnormal gene causing this disorder. These data suggest that fibronectin receptor is closely related to the pathogenesis of hereditary connective tissue diseases.

Adult↗
PubMed1990

[A primary malignant lymphoma of the appendix].

A malignant lymphoma (ML) of the gastrointestinal tract occurs most frequently in the stomach, and ML of the appendix is very rare, with only 16 cases reported in the Japanese literature. Reported is a case of a primary ML the appendix in a 48 year old male, in whom an ileocecal resection was carried out. This case was pathohistologically diagnosed as a diffuse large lymphoma of the B cell type, according to the LSG classification. Therapeutic problems were encountered because of the difficulty in making an early diagnosis.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1990

[Biological evaluation of extracellular superoxide dismutase observed in a state of acute gastric mucosal lesions].

In the experimental stress ulcer models of guinea pig superoxide dismutase-like plasma substance increased in plasma. Upon chromatography on heparin-Sepharose, this substance was separated into three fractions; A, without affinity for heparin; B, with intermediate affinity for heparin; C, with relatively strong heparin affinity, and the fraction C was specifically increased by a stress and a heparin injection. Analysis by a polyacrylamide gel electrophoresis (PAGE) of the fraction C revealed SOD activity, whose molecular weight was 135 K in a native state. The fraction C seemed to be the same as extracellular superoxide dismutase (EC-SOD) reported by Marklund. Assuming to the releasing potency of heparin, the major part of EC-SOD in the vasculature was most likely located on endothelial-cell surface. A pathophysiological role of EC-SOD released into plasma seemed to be an indicator of endothelial-cell damage by free radicals of endothelial cells and polymorphonuclear neutrophils (PMNs).

Acute Disease↗
PubMed1990

Changes in arterioles of the human gastric mucosa with atrophic gastritis.

Arteriolar changes in the gastric mucosa of 18 patients with atrophic gastritis and of 13 control subjects without atrophic gastritis were investigated using electron microscopy. Irregularly configured smooth muscle cell atrophy with lysosomes and interstitial deposition of highly electron dense material were found in mucosal arterioles of the patients with atrophic gastritis. These findings were similar to the findings seen in patients with hypertension, and animals with experimentally-induced hypertension. Similar, but mild, changes were also noted in mucosal arterioles of control subjects. However, such findings were more common in the aged. These results suggest that the arteriolar changes in the gastric mucosa represent fundamental factors causing atrophic gastritis.

Adult↗
PubMed1989

Presence of glucagon-(1-21)-Like immunoreactive substance in the dog small intestinal mucosa.

By using an antiserum (K291) specifically directed to the C-terminal of glucagon-(1-21)-peptide, we demonstrated the presence of glucagon-(1-21)-like immunoreactivity (G21-IR) in the dog intestine. G21-IR was found to be widely distributed throughout the small intestine and colon in parallel with the distribution of glucagon-like immunoreactivity (GLI), measured by N-terminal glucagon antiserum (OAL196). The subsequent analyses by gel filtration and three HPLC columns (reverse phase, ion exchange and further reverse phase columns) showed that G21-IR consisted of three main peaks, and the smallest molecular form of G21-IR is identical to glucagon-(1-21)-peptide.

Amino Acid Sequence↗
PubMed1989

Cloning, nucleotide sequence, and expression of Achromobacter protease I gene.

Achromobacter protease I (API) is a lysine-specific serine protease which hydrolyzes specifically the lysyl peptide bond. A gene coding for API was cloned from Achromobacter lyticus M497-1. Nucleotide sequence of the cloned DNA fragment revealed that the gene coded for a single polypeptide chain of 653 amino acids. The N-terminal 205 amino acids, including signal peptide and the threonine/serine-rich C-terminal 180 amino acids are flanking the 268 amino acid-mature protein which was identified by protein sequencing. Escherichia coli carrying a plasmid containing the cloned API gene overproduced and secreted a protein of Mr 50,000 (API') into the periplasm. This protein exhibited a distinct endopeptidase activity specific for lysyl bonds as well. The N-terminal amino acid sequence of API' was the same as mature API, suggesting that the enzyme retained the C-terminal extended peptide chain. The present experiments indicate that API, an extracellular protease produced by gram-negative bacteria, is synthesized in vivo as a precursor protein bearing long extended peptide chains at both N and C termini.

Alcaligenes↗
PubMed1989

Fructose-related glycation.

We investigated in vitro the effect of the polyol pathway on the formation of advanced Maillard reaction products which have fluorescence and cross-links. Bovine serum albumin supplemented with various concentrations of glucose, fructose or sorbitol was incubated for 14 days. The fluorescence intensity was higher after incubation with fructose than after incubation with glucose. However, no significant increase in fluorescence intensity was found after incubation with sorbitol. These results suggest that in the polyol pathway fructose plays an important role in the formation of advanced Maillard products.

Fructose↗
PubMed1989

Biochemical examination on the increased superoxide dismutase-like plasma substance observed in a state of acute gastric mucosal lesions.

When experimental acute gastric mucosal lesions were produced in guinea pig by water-immersion and restraint stress, superoxide dismutase (SOD)-like substance in the plasma increased. On analysis by gel filtration, it was shown that the molecular weight of the increased SOD-like plasma substance was about 130,000, and even after treatment with trypsin, 84% of this substance remained. Since the molecular weight of intracellular SOD is about 40,000, it seems that this substance is similar to extracellular SOD, located on the endothelial cell-surface, as previously reported by Marklund et al. Our results suggest that in the presence of acute gastric mucosal lesions, SOD-like plasma substance is not identical to intracellular SOD, which derived from cell destruction by stress or free radical-induced microvascular damage or by hemolysis. Furthermore, this substance may itself work as a scavenger of free radicals generated under conditions, such as these described in the present experiment.

Animals↗
PubMed1989

Clinical application of hair protein glycation in the assessment of blood glucose control and diabetic neuropathy.

Glycation of hair protein was assessed in diabetic patients by the measurement of furosine, which is derived from fructose-lysine, a glycated lysine residue in protein. The level of furosine in 12-cm-long hair which grew over the course of one year was significantly better correlated with the mean values of four determinations of fasting plasma glucose (FPG) and four determinations of hemoglobin A1c, respectively, at the time of hair sampling. The level of glycation in hair, which corresponds to the time taken for hair growth, may represent the mean level of blood glucose during the time corresponding to the growth period. The values of motor nerve conduction velocity and sensory nerve conduction velocity were better correlated with the level of furosine in hair corresponding in the length to 1 year's growth than the levels of FPG and hemoglobin A1c at the time of the determination of nerve conduction velocity. These results suggest that hair glycation may serve as a valuable indicator both of long-term blood glucose trends and of the relationship between diabetic complications and blood glucose.

Adult↗
PubMed1989

The effect of fructose on collagen glycation.

The effect of fructose on the formation of advanced Maillard reaction products which have fluorescence and cross-links was investigated. Type I collagen was added to various concentrations of glucose and fructose which were then incubated at 37 C for 4 weeks. Both the level of furosine and the fluorescence intensity increased in direct proportion to glucose and fructose levels and to the duration of incubation. Incubation with fructose produced less furosine but more intense fluorescence than incubation with glucose. These results suggest that fructose in the polyol pathway plays an important role in the formation of advanced Maillard products.

Animals↗
PubMed1989

Binding of plasma fibronectin to human polymorphonuclear leukocytes in normal subjects and patients with aplastic anemia and thyroid dysfunction.

The binding of iodine 125-labeled fibronectin to polymorphonuclear leukocytes (PMNs) from human peripheral blood was examined. The optimum temperature and time for the binding were 37 degrees C and 30 minutes, respectively. On increase in the amount of 125I-labeled fibronectin, its binding to PMNs became saturated. Scatchard analysis of data on binding indicated the presence of a single class of binding sites. PMNs from 15 normal subjects had approximately 6.3 +/- 1.6 x 10(3) sites per cell and a dissociation constant of 10.2 +/- 2.4 x 10(-9) mol/L, indicating that they had high affinity for soluble fibronectin. Arg-Gly-Asp-Ser inhibited the binding of fibronectin to PMNs, strongly suggesting that the fibronectin receptor is one of the Arg-Gly-Asp receptor family. The plasma level of fibronectin was higher in patients with hyperthyroidism and lower in patients with hypothyroidism than in normal subjects, without any significant change in the number of fibronectin binding sites of the PMNs. However, the number of binding sites of fibronectin on PMNs of patients with aplastic anemia was increased, probably because of sensitization of the PMNs with immune complex and other factors.

Anemia, Aplastic↗
PubMed1989

[Possible mechanisms of diethyldithiocarbamate-induced duodenal mucosal damage in rats].

Diethyldithiocarbamate (DDC), which markedly lowers activity of Cu, Zn-superoxide dismutase (SOD), induces not only gastric but also duodenal mucosal damage in rats. In this experiment, we studied on the mechanisms of DDC-induced duodenal mucosal damage with special reference to aggressive and defensive factors. Possible importance of oxygen-derived free radicals was also investigated. Male Wistar rats weighing about 200 g received a single subcutaneous injection of DDC at a dose of 1 g/kg. Mucosal lesions such as edema, shortness of villi and shallow erosion developed from 3 hours after DDC injection. The ulcer index reached at its maximum 12 hours later. Gastric acid output was markedly inhibited from 87.7 +/- 8.7 to 14.0 +/- 2.6 microEq/kg/h (m +/- SE) 30 minutes after the administration of DDC (p less than 0.01), which gradually recovered thereafter. Duodenal mucosal blood flow before DDC injection was 144.7 +/- 12.7 ml/min/100 g, which decreased to 83.3 +/- 5.1 (p less than 0.01) 1 hour later. Transmucosal potential difference of the duodenum before DDC injection was -9.5 +/- 1.0 mV, which decreased to -3.8 +/- 1.3 (p less than 0.05) 30 minutes later. Duodenal alkaline secretion before DDC injection was 15.6 +/- 0.8 microEq/kg/h, which decreased to 5.0 +/- 0.9 microEq/kg/h (p less than 0.01) 90 minutes later. PAS-stained mucus of Brunner's glands remained unchanged by the administration of DDC. SOD activity was markedly inhibited from 57.7 +/- 4.0 to 15.7 +/- 0.9 u/mg protein 3 hours after the administration of DDC (p less than 0.01), then recovered 24 hours later.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Effect of aminoguanidine on the glycation.

3-Deoxyglucosone, a carbonyl intermediate compound in the Maillard reaction, acts on bovine serum albumin to increase its fluorescence. Aminoguanidine inhibited the increase of fluorescence intensity formed by bovine serum albumin and 3-deoxyglucosone when 3-deoxyglucosone had been preincubated with aminoguanidine. These results suggested that aminoguanidine inhibits the action of 3-deoxyglucosone in the Maillard reaction.

Animals↗