Search PubMed⌕ Search

Biomedical subjects

Y Kakiuchi

Publications and source records attributed to Y Kakiuchi.

At least 37 records · Page 2Linked to original sources
PubMed1990

The tumour-localizing properties of porphyrin derivatives.

The tumour-localizing abilities of various kinds of porphyrin derivatives in tumour-bearing hamsters were assessed by nitrogen-pulsed laser spectrofluorometry (N2-PLS). On examination of porphine derivatives (from haemoglobin), it was found that the dimer and acetylated and amidated compounds had a high affinity for tumour tissue; the dimer and hydroxylated compound of phorbine derivatives (from chlorophyll) also showed a high affinity. Furthermore, of the metalloporphines (gallium, zinc and indium complexes), those which contained hydrophilic groups showed a high affinity for tumour tissue; of the metallophorbines (gallium, zinc and indium complexes), those which contained hydrophobic groups showed a high affinity. A correlation was found between the side-chain structure of the porphyrins and metalloporphyrins and their affinity for tumour tissue.

Animals↗
PubMed1990

[Degree and extension of analgesic effect of morphine applied at three different spinal levels of epidural space].

Forty-five patients undergoing total abdominal hysterectomy were randomly divided into three groups. An epidural tube was inserted into one of the following three sites, Th11-12, L2-3, and caudal region. General anesthesia was then maintained with nitrous oxide-oxygen-enflurane, and pancuronium bromide. Morphine hydrochloride 2 mg in 8 ml of normal saline was administered into one of the designated epidural spaces one to two hours before the assumed end of surgery. Postoperative pain was assessed every four hours after the end of the operation until the next morning. Morphine exerted a relatively profound and prolonged analgesic effect in 40% of the Th11-12 group of patients, as well as in 6.7% of the L2-3 and caudal groups. But, supplementary analgesics were necessary in the other patients. No significant differences were found in the degree and extension of postoperative pain, as well as the doses of supplementary analgesics among the three groups. Adverse effects, such as nausea, vomiting and itching, occurred in 30 to 40% of each of the morphine administered groups. Though morphine was applied into different spinal levels, this clinical study did not show any difference in extension of analgesia. The epidurally applied morphine may be distributed widely in the spinal arachnoid space after some time, and may exert an effect on the brain as well as on the spinal nerves. When morphine is administered epidurally one to two hours before the end of a surgical operation, selection of an injection site according to the dermatome level of the skin incision may be unnecessary.

Adult↗
PubMed1988

Plasma cell leukaemia of non-producer type with missing light chain gene rearrangement.

A case of plasma cell leukaemia of non-producer type is described. The patient presented with typical clinical features of plasma cell myeloma, including multiple osteolytic lesions, hypercalcaemia, renal failure and reduced polyclonal immunoglobulins, except that M-component was not detected in either the serum or urine. Morphological examinations showed a plasmacytoid appearance of the neoplastic cells, while immunological studies failed to detect cytoplasmic immunoglobulin or secretory capacity. The surface phenotype of CD38+, PCA-1+, DR-, CD20-, CD24-, CD9-, CD10- and surface immunoglobulin- was compatible with mature plasma cells. Chromosomal analysis showed the 14q+ marker due to translocation (6;14) and deletion of the short arm of chromosome 1. Analysis of immunoglobulin genes revealed the presence of heavy chain gene rearrangement, but the light chain genes, both kappa and lambda, remained in germline configuration. Such defective immunoglobulin gene rearrangement may be responsible for the failure of immunoglobulin biosynthesis and secretion by the neoplastic plasma cells. Furthermore, it is suggested that the morphological and phenotypic development of B cells may not necessarily depend on immunoglobulin light chain gene rearrangement, and that the oncogenic event in myeloma may occur at an earlier stage of B cell differentiation.

Chromosome Aberrations↗
PubMed1986

Viscosity and order in erythrocyte membranes studied with nanosecond fluorometry.

The viscosity and the order in the interior of human erythrocyte membranes were investigated by the fluorescence depolarization technique in the nanosecond region with 1,6-diphenyl-1,3,5-hexatriene (DPH). After pulsed excitation with a polarized light, the fluorescence anisotropy ratio of DPH in membranes rapidly decreased and gave a final value (r infinity). The rate of initial decrease and the value of r infinity related to the viscosity in the interior of the membranes and a wobbling angle of DPH which reflects a size of range for the phospholipid motion relating to the order of membrane structure. For normal human erythrocyte membranes the viscosity and the wobbling angle were obtained to be 0.82 poise and 42 degrees, at 37 degrees C. Similar values were obtained for spectrin-free membranes. Hardened membranes by the cross-linking of the cytoskeletal proteins with glutaraldehyde showed a small wobbling angle of 37 degrees, but the viscosity of them was unchanged.

Blood Viscosity↗
PubMed1985

Effects of temperature and transfer from seawater to freshwater on blood microrheology in Pacific salmon.

Blood of Pacific salmon was studied with particular interest in red blood cell (RBC) deformability in relation to migration. Blood samples were taken via cardiac puncture or chronic cannula placed in the dorsal aorta and heparinized. As an index of RBC deformability the mean passage time of single RBCs through micropores of 8 micron in diameter and 10 micron in length was determined under a pressure difference of 10 cmH2O. Despite about 100 mOsmol/l difference in plasma osmolality, there was no marked difference in RBC passage time between fish in seawater and those well acclimatized to freshwater. However, it seemed probable that a transient decrease in RBC passage time, i.e., an increase in RBC deformability, occurred immediately following transfer from seawater to freshwater. Plasma osmolality decreased to about 300 mOsmol/l within 1 hr after the transfer and showed no fluctuations thereafter. The temperature dependence of RBC deformability was much smaller in comparison with those previously observed in yellowtail and carp; salmon RBCs were still highly deformable even at 5 degrees C, a possible temperature of cold river water.

Animals↗
PubMed1984

Hypoxic reduction in blood flow velocity in pulmonary arterioles and capillaries.

A small ring chamber (I.D. = 6 mm) was placed on the exposed lung of anaesthetized bullfrogs. A localized hypoxia was induced in the ring chamber by introducing nitrogen in it. Blood flow velocity in pulmonary microvessels was measured by means of a laser Doppler microscope. The mean blood flow velocity was 1.98 +/- 0.45 and 1.52 +/- 0.10 mm/sec during the control condition in arterioles and capillaries, respectively. It was then reduced by the localized hypoxia to 1.63 +/- 0.32 and 1.33 +/- 0.08 mm/sec in arterioles and capillaries, respectively. The reduction, when expressed in the percentage ratio to the control flow velocity in each blood vessel group, was significantly larger in arterioles than in capillaries. A phase delay in the pulsation of the flow velocity contour was detected only in arterioles. These differences between pulmonary arterioles and capillaries in response to the localized hypoxia may be attributed to the dense interconnection of capillary network extending beyond the localized hypoxic area to the normoxic area.

Animals↗
PubMed1982

Laparoscopic findings of the liver in the diagnosis of primary biliary cirrhosis: "reddish patch", a laparoscopic feature in the asymptomatic stage.

The laparoscopic findings of the livers of 12 patients with primary biliary cirrhosis (PBC), including six asymptomatic and six symptomatic cases, were investigated. On the liver surface of asymptomatic PBC, we found a laparoscopic appearance, consisting of reddish patches of irregular shape, ranging from 0.5 to 3 cm in diameter, and not evenly distributed. Five of six cases of asymptomatic PBC had reddish patches in our series. From serial laparoscopic observations, the patches were found to lose some of their reddish tone and to develop protuberances with vaguely outlined white markings in each reddish areas. The protuberances and white markings are characteristic appearances of the liver surface in more advanced PBC cases. The transition of reddish patches to protuberances with white markings coincided with progression among histopathological stages in PBC classified by Scheuer. A histometrical examination showed that areas with reddish patches had less advanced changes of intrahepatic bile ducts. As a result, we propose that laparoscopic findings of the liver have a value in the diagnosis of PBC and "reddish patch" is considered a laparoscopic feature which has no been described in asymptomatic PBC.

Adult↗
PubMed1982

Red blood cell deformability in renal failure.

Red blood cell deformability was measured in 74 cases of renal failure and diabetic nephropathy by means of a modified nuclepore membrane filter method. Low red blood cell deformability was observed in a certain proportion of the patients. In cases of renal failure only weak correlation was found between reduced red blood cell deformability and BUN as well as between reduced red blood cell deformability and creatinine level, while simultaneous changes in these variable were observed in several patients. The reduction in red blood cell deformability in cases of diabetic nephropathy slightly exceeded that in cases of renal failure and correlated with an increment in HbA1c content. The effects of uremic toxins were unclear in in vitro tests. The red blood cell deformability was impaired in nephrectomized rabbits.

Animals↗
PubMed1982

White blood cell adhesion to endothelium and rheological behavior in microvessels of overinflated frog's lung.

The flow behaviors of white blood cells (WBCs) in frog's pulmonary microvessels were recorded and analyzed by means of a microscope-TV camera system. When the flow velocity in arterioles was reduced to a level lower than 1 mm/sec by a moderate overinflation of the exposed lung, WBCs rolled on the endothelial surface, frequently came in contact with the capillary orifice and passed it quickly without deformation. The time length which was required for WBCs to pass through the capillary orifice was shorter than the time length for red blood cells. This observation suggested that WBCs were no hinderance to blood delivery from arterioles to the capillary network in the normal and moderate overinflation of the lung. However, when the lung was strongly overinflated and the center line flow velocity was reduced to 0.1 mm/sec, WBCs adhered to the endothelium in ten minutes. The adhering WBCs could not be detached by the recovery of the blood flow. It seemed probable that a large shear stress up to 100 to 200 dynes/cm2 was necessary to pull down the interaction between the adhering WBCs and the endothelium.

Animals↗
PubMed1981

Effect of transpulmonary pressure on blood-flow velocity in pulmonary microvessels.

Flow velocity in the microvessels (30 to 90 micron in diameter) on the exposed lung surface of anesthetized bullfrogs was measured during positive lung inflation by means of a laser Doppler microscope. From the pulsatile flow-velocity contour generated by cardiac cycles, mean flow velocity (MV) and pulsatile amplitude (PA) were calculated and their alterations were studied as a function of transpulmonary pressure (TPP). At the lowest TPP of 1.3 +/- 0.8 cm H2O (mean +/- SD), MV and PA were 1.72 +/- 0.33 and 0.45 +/- 0.27 mm/sec, respectively. With moderate increments in TPP up to 2.8 +/- 1.3 cm H2O, both MV and PA increased, attaining maximum values of 2.11 +/- 0.42 and 0.69 +/- 0.28 mm/sec, respectively. But with further inflation they began to decrease, and there was a marked reduction or a complete arrest of blood flow at excessively high TPPs (6 to 9 cm H2O). With reduction of previously increased TPP, the alterations in MV and PA followed a pattern similar to that noted during elevation of TPP. There was an apparent hysteresis in both the MV-TPP and PA-TPP curves, most marked when excessively high TPP was applied.

Animals↗
PubMed1981

Transvascular osmotic flow reflected by changes in plasma oncotic pressure of anesthetized dog.

To assess overall bodily transvascular fluid flow due to osmotic imbalance between blood and interstitial fluid during or after addition of hypertonic saline, sugar-, albumin- and dextran solutions or CO2 mixture to blood, arterial blood colloid osmotic pressure (COP) of anesthetized dogs was continuously measured with a needle-type colloid osmometer. Plasma volume change (delta Vp) was estimated from the changes in either the equivalent albumin concentration (C) or the albumin concentration equivalent to plasma COP, which was well confirmed in inanimate model experiments. Carbon dioxide inhalation caused RBC swelling (1.5% volume increase/10 mmHg of PCO2). Intravenous injection of hypertonic solutions resulted in transient osmotic flow (8.5 +/- 2.2 ml/g of solute per kg of animal weight by NaCl, and 1.7 +/- 0.4 by glucose), and albumin and dextran also induced fluid flow (1.3 +/- 0.4 by albumin and 2.2 +/- 0.7 by dextran), which depended on van't Hoff's law and reflection coefficient of solutes.

Animals↗