Search PubMed⌕ Search

Biomedical subjects

K Nitta

Publications and source records attributed to K Nitta.

At least 253 records · Page 14Linked to original sources
PubMed1989

[Effects of hypopressure on blood gases and spirograms of patients suffering from chronic respiratory failure].

We examined the effects of hypopressure on blood gases and spirograms of patients suffering from chronic respiratory failure, and compared them with those of normal subjects, using the environmental control unit (ECU). The patients consisted of 2 with idiopathic interstitial pneumonia (IIP), 1 with pulmonary fibrosis due to RA, 3 with bronchiectasis, 2 with chronic bronchitis and 1 with diffuse panbronchiolitis (DPB). We examined their blood gases and spirograms under the condition of 760 mmHg pressure, 25 degrees C temperature and 60% humidity. Then the pressure of ECU decreased to 670 mmHg in 20 minutes, while the temperature and humidity were kept the same. The patients stayed in the hypopressured ECU for 1 hour, and were reexamined. The pressure of 670 mmHg is that of an altitude of about 1,000 m and that of the cabin pressure of commercial aircraft flying at about 9,000 m. The PaO2 of the patients decreased from 74.7 +/- 13.8 torr to 61.8 +/- 9.5 torr significantly. We found, however, the significant decrease of PaO2 in normal subjects from 97.2 +/- 7.8 torr to 80.4 +/- 6.5 torr under the same conditions. The rates of the decreased gases were almost same in both groups. Some patients showed remarkable decreases in VC and FEV1.0 under the hypopressure. No patients or control subject complained of subjective symptoms.

Adult↗
PubMed1989

Effects of atrial natriuretic peptide on regional renal blood flow measured by a thermal diffusion technique.

The effects of atrial natriuretic peptide (ANP) on the regional renal blood flow were examined in anesthetized dogs. A thermal diffusion technique was applied in an attempt to observe the intrarenal blood distribution. Tissue blood flow was continuously measured according to the changes of the thermal gradient produced by a semiconductor (Peltier effect). The data (x) obtained by these probes were closely related to those (y) of the ion gas clearance method (the probe for cortical blood flow; y = 1.08x-6.23 r = 0.99, the probe for medullary blood flow; y = 1.00x +0.26 r = 0.99). The basal values of cortical and medullary blood flows measured with the flow probe in anesthetized mongrel dogs were 85 +/- 16 and 55 +/- 9 ml/min/100 g kidney weight, respectively. ANP was infused into renal artery at doses of 0.01 (n = 6), 0.05 (n = 8), 0.3 (n = 6) micrograms/kg/min and the effect on renal hemodynamics and renal excretory functions was observed. The effect was also compared with that of furosemide. Low dose of ANP did not affect renal blood distribution. Intermediate dose of ANP selectively increased medullary blood flow from 46 +/- 8 to 62 +/- 7 ml/min/100 g kidney weight, and higher dose significantly increased both cortical and medullary blood flow. ANP produced diuresis and natriuresis in a dose-dependent manner, which was not necessarily related to the changes of intrarenal blood distribution. Furosemide did not affect the renal hemodynamics. Several parameters of renal functions such as lithium and free water clearances, showed changes different from those with ANP infusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Role of atrial natriuretic peptide on sodium homeostasis in experimental renal failure.

In a study of the role of atrial natriuretic peptide (ANP) in sodium homeostasis in experimental renal failure, we found that a infusion of ANP at 0.25 microgram/min for 15 min produced an increase in the glomerular filtration rate (GFR) and fractional excretion of sodium (FENa) in five-sixth nephrectomized (5/6 Nx) rats. Renal vascular resistance (RVR) was lower during the base-line period and did not change after the administration of 100 ng/ml ANP to isolated perfused kidney (IPK) from adriamycin-treated rats. Furthermore, fractional excretion of ANP (FEANP) by IPK decreased in kidneys from adriamycin-treated rats as compared to that in kidneys from control rats. Finally, after 5/6 Nx, levels of plasma immunoreactive ANP (ir-ANP) gradually increased but excretion of water and sodium did not change during normal intake of sodium. The increase in levels of ir-ANP was accompanied by an increase in the rates of excretion of water and sodium was observed 2 days later but these rates returned to the base-line values after 2 weeks. These findings suggest that ANP plays an important role in the adjustment of acute changes in the volume of extracellular fluid during experimental renal failure.

Animals↗
PubMed1989

[Primary torsion of the omentum--report of a case and review of the Japanese literature].

A case of primary torsion of the omentum is reported. A 37-year-old male was admitted with the chief complaint of RLQ pain of 3 day's duration on June 10, 1986. Tenderness and Blumberg's sign were found at Mc Burney's point with leucocytosis of 11,500/mm3. His body temperature was not elevated. Operation was carried out under the diagnosis of suspicion of acute appendicitis. Laparotomy revealed a dark-red omental mass of 12 X 5 X 1 cm which had been formed by torsion (7 times, clock-wise) and a little clear ascites. The omental mass was resected, and appendectomy was also performed. The postoperative course was uneventful. Eighteen cases including this case in the Japanese literature were reviewed and reported.

Adult↗
PubMed1988

Comparative studies of the haemagglutination of adult and umbilical cord erythrocytes by animal lectins.

1. The sugar specificities of four lactose-binding lectins were studied through the agglutination of adult and/or umbilical cord human erythrocytes (AHRBC and/or CHRBC). 2. Rana catesbeiana egg lectin specifically agglutinated both intact blood group A-AHRBC and intact blood group A-CHRBC. 3. Rana catesbeiana liver lectin agglutinated intact A-AHRBC much more strongly than intact A-CHRBC. 4. Xenopus laevis skin lectin nonspecifically agglutinated AHRBC and CHRBC. 5. Plecoglossus altivelis egg lectin specifically agglutinated intact B-AHRBC, but weakly agglutinated intact B-CHRBC. 6. Comparative studies of lectin-induced AHRBC or CHRBC agglutination clarified the sugar-binding specificities of these lectins.

Adult↗
PubMed1988

Distribution of 67Ga-citrate in abscess-induced rat by quantitative whole body autoradiography.

Distribution of 67Ga-citrate in inflammatory tissues was determined, and correlation between the 67Ga-uptake and capillary permeability of plasma from blood vessels in the inflammatory tissue was elucidated, by quantitative whole body autoradiography and double tracer autoradiography. The distribution of 67Ga in inflammatory tissue was similar to that of 131I-HSA and 99mTc-HSA, which were applied as an index to the plasma element. These results showed that the capillary permeability of plasma from blood vessels in the inflammatory tissue increases, and this causes the 67Ga-uptake.

Abscess↗
PubMed1988

Calcium-binding lysozymes.

It was found that pigeon lysozyme binds one calcium ion, as does equine lysozyme. The protein was eluted with equimolar calcium ions from a Bio-Gel P-60 column. The binding constants of equine and pigeon lysozymes were determined to be 2 x 10(6) and 1.6 x 10(7) M-1, respectively, in 0.1 M KCl at pH 7.1 and 20 degrees C. During evolution the gene of calcium-binding lysozyme is deduced to be separated from that of non-calcium-binding lysozyme by gene duplication before splitting of avian and mammalian lineages, from their amino-acid sequences. It is assumed that the alpha-lactalbumin might have evolved from calcium-binding lysozyme.

Animals↗
PubMed1988

Immunohistochemical localization of atrial natriuretic peptide binding sites in juxtaglomerular cells and vascular walls of rat kidney.

Since the kidney is one of the major sites of action for atrial natriuretic peptide (ANP) and immunoreactive ANP has been detected in tissue extract by radioimmunoassay, we have applied the immunohistochemical technique by using the avidin-biotin complex method to investigate ANP binding sites in the rat kidney. Although no immunostaining was observed in the kidney of control rats, immunoreactive ANP was present in the juxtaglomerular cells, the vascular walls of interlobular arteries, arcuate arteries, arterioles including vas afferens and vas efferens, and the medullary peritubular capillary of ANP-pretreated rats. In contrast, no tubular structure was stained. These results suggest that ANP may affect renin secretion via its direct action on the juxtaglomerular cells and that it predominantly induces natriuresis by its effects on renal hemodynamics.

Animals↗
PubMed1987

Antitumor activity of 7-ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxy-camptothec in, a novel water-soluble derivative of camptothecin, against murine tumors.

The search for new water-soluble analogues of camptothecin (CPT) with higher activity and less toxicity has led to the development of a novel compound, 7-ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxy-camptothecin (CPT-11), which showed significant antitumor activity against a broad spectrum of experimental tumor models by i.p., i.v., or oral administration. When its activity against L1210 was compared with that of CPT and known derivatives, CPT-11 was most effective, giving the highest maximum increase in life span (ILS) and showing good activity over a wide dose range. The antitumor activity of CPT-11 was shown against tumors not only in the ascites form but also in the solid form. Included among the more susceptible murine tumors are S180, Meth A fibrosarcoma, Lewis lung carcinoma, Ehrlich carcinoma, MH134 hepatoma, mammary carcinoma of C3H/HeN mice, L1210, and P388 leukemia. Probable cures of these tumors were induced frequently by CPT-11. The antitumor activity of CPT-11 against i.p.-implanted L1210 was superior to that of Adriamycin in maximum ILS, the number of cured mice, and the therapeutic ratio. CPT-11 at a dose of 100 mg/kg produced an ILS in excess of 300% with five of six mice surviving tumor free, and effected 100% tumor regression at 200 mg/kg, whereas the optimum dose of Adriamycin, 12.5-25 mg/kg, brought about 114-129% ILS with one of six mice surviving. The acute toxicity of CPT-11 was extremely low, particularly in the case of oral administration. CPT-11 is expected to be clinically useful.

Animals↗
PubMed1987

The calcium-binding property of equine lysozyme.

It was found that equine lysozyme binds one Ca2+. It was eluted with equimolar Ca2+ from a Bio-Gel P-4 column. Human lysozyme did not behave similarly. Equine lysozyme is concluded to be a calcium metallo-protein like alpha-lactalbumin, which is a homologue of hen egg white lysozyme.

Animals↗
PubMed1987

Isolation and characterization of Rana catesbeiana lectin and demonstration of the lectin-binding glycoprotein of rodent and human tumor cell membranes.

A lectin isolated from Rana catesbeiana eggs preferentially agglutinates a large variety of human and animal tumor cells but not normal red blood cells, lymphocytes, or fibroblasts. The phenomenon correlates with a higher binding activity of the lectin with tumor cells. Chemical and physical analysis of the purified lectin indicates that the lectin is a low molecular weight basic polypeptide with five intrachain disulfide bonds. Its agglutination of tumor cells was abolished by blocking the amino group. The lectin strongly binds with a large variety of tumor cells but binds only minimally with fibroblasts, lymphocytes, and erythrocytes. Tumor cell agglutination induced by this lectin was strongly inhibited by submaxillary mucin, to a lesser degree by fetuin and keratan sulfate, and not at all by less-sialylated glycoproteins, such as transferrin. Inhibition by mucin or fetuin was greatly reduced by desialylation of glycoprotein with sialidase. Treatment of tumor cells with sialidase greatly reduced the lectin-dependent agglutination, and the sialidase-dependent reduction of tumor cell agglutination was inhibited by the sialidase inhibitor 2,3-dehydro-2-deoxy-N-acetylneuraminic acid. However, tumor cell agglutination was not inhibited by chondroitin sulfates or hyaluronic acid. Thus, the lectin-dependent tumor cell agglutination is due to a high density of sialic acid at the cell surface. The receptor glycoprotein that interacts with this lectin was demonstrated in the detergent-insoluble fraction of a variety of tumor cells by sodium dodecyl sulfate:polyacrylamide gel electrophoresis, followed by Western blotting with lectin and anti-lectin antibodies. The presence of a common high molecular weight lectin-binding glycoprotein in various tumor cells was demonstrated.

Agglutination↗