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Biomedical subjects

T Sako

Publications and source records attributed to T Sako.

At least 73 records · Page 4Linked to original sources
PubMed1997

Hepatic carnitine palmitoyltransferase activity in cattle.

A fluorometric assay for the determination of hepatic carnitine palmitoyltransferase (CPT) activity was slightly modified for use with cattle samples. With this assay, the Km value was 0.56 +/- 0.10 mM with respect to L-carnitine (mean +/- SD, n = 4) and was 9.6 +/- 2.2 microM (n = 3) with respect to palmitoyl-CoA. The average hepatic CPT activity was 33.6 +/- 2.0 mumol CoASH/min/g protein in 38 healthy cattle and was similar in both sexes and among breeds. Hepatic CPT activity showed no correlation with serum phospholipid, free fatty acid, triglyceride or total cholesterol concentrations.

Animals↗
PubMed1997

Serum concentration of circulating immune complexes in cats infected with feline immunodeficiency virus detected by immune adherence hemagglutination method.

Circulating immune complexes (CIC) in the sera from 45 clinically healthy cats and 23 feline immunodeficiency virus (FIV) infected cats were measured by an immune adherence hemagglutination (IAHA) method. The level of CIC in the sera from FIV sera-negative healthy cats was 47.2 +/- 47.3 micrograms/ml when expressed as heat aggregated feline IgG equivalent value in IAHA reactivity. On the other hand, the level of CIC in the sera from FIV infected cats was 757.4 +/- 910.5 micrograms/ml, which was significantly higher than that of healthy ones. CIC levels of 11 symptomatic cats and 12 asymptomatic ones were 837.8 +/- 1138.2 micrograms/ml and 683.0 +/- 684.2 micrograms/ml, respectively. These results showed that IAHA method was reliable to detect CIC levels of cat sera and that CIC levels in the sera of cats infected with FIV were higher than those of healthy ones.

Aging↗
PubMed1996

Detection of circulating immune complexes in dog sera by immune adherence hemagglutination method.

Circulating immune complexes (CIC) in the sera from 102 clinically healthy dogs and from 16 Dirofilaria immitis (D. immitis) infected dogs were measured by the immune adherence hemagglutination (IAHA) method. The level of CIC in the sera from healthy dogs was 28.2 +/- 29.1 micrograms/ml. There was no significant difference in the levels of CIC regarding sexes or ages. On the other hand, the level of CIC in the sera from D. immitis infected dogs was 230.3 +/- 117.1 micrograms/ml, which was significantly (p < 0.01) higher than that of healthy dogs. The results of this study confirm that IAHA method is one of the reliable means of detecting and/or diagnosing immune complex mediated diseases in dogs.

Aging↗
PubMed1995

Effect of staphylokinase concentration of plasminogen activation.

Activation of Glu- and Lys-plasminogen by various concentrations of recombinant staphylokinase (SAK) were studied by the generation of amidolytic activity from the chromogenic substrate S-2251(H-D-Val-Leu-Lys-pNA) and by SDS-PAGE analysis. Surprisingly, excess SAK decreased and fixed the rate of S-2251 hydrolysis in a mixture of Lys-plasminogen and SAK. Since the effect of SAK on S-2251 hydrolysis by plasma was similar, the hydrolysis kinetics by free plasmin and plasmin-SAK complex were studied. Hydrolysis by either enzyme form followed Michaelis-Menten kinetics with a Km of 0.38 mM for plasma and 3.74 mM for SAK-plasmin complex. The catalytic rate constant was 22.7 s-1 for plasmin and 21.0 s-1 for the SAK-plasmin complex. With excess SAK and vigorous removal of plasmin activity from plasminogen, the pre-activation lag period differed greatly between Glu- and Lys-plasminogen. Based on the different substrate specificity of plasmin and plasmin-SAK complex, we analyzed the Glu-plasminogen activation with either catalytic or excess SAK. With excess SAK, almost no Lys-plasminogen was detectable and whole Glu-plasminogen was converted directly to Glu-plasmin, then gradually to Lys-plasmin. In contrast, Lys-plaminogen appeared rapidly with catalytic amount of SAK. These results suggest that inhibition of Glu-plasminogen to Lys-plasminogen to Lys-plasminogen conversion in the plasminogen-SAK complex in the presence of excess SAK prolonged the initial lag phase of activation.

Dose-Response Relationship, Drug↗
PubMed1995

DNase I interaction on muscle Z-line.

The effect of deoxyribonuclease I on muscle Z-line structures was re-examined. Under conditions of deoxyribonuclease I activation (presence of the divalent cation Ca2+ and Mg2+), a deoxyribonuclease I preparation did not affect Z-line structure if phenylmethylsulfonylfluoride, an inhibitor of serine proteases, was also present. In the absence of protease inhibitor, both Z-lines and M-lines were digested, even in the presence of EDTA and EGTA as inhibitors of deoxyribonuclease I. These electron microscopic observations were consistent with the following results from sodium dodecyl sulphate gel electrophoresis: when the protease was inhibited but deoxyribonuclease I was activated, myofibrillar proteins remained essentially intact. However, degradation of proteins in both rabbit psoas and chicken pectoralis myofibrils was observed in the presence of deoxyribonuclease I inhibitors when the protease inhibitor was absent. Our data strongly suggest that the interaction of deoxyribonuclease I with Z-line proteins previously reported is most likely due to contamination of the deoxyribonuclease I fraction by the serine-type proteases.

Animals↗
PubMed1995

D-glucose transport and glycolytic enzyme activities in erythrocytes of dogs, pigs, cats, horses, cattle and sheep.

The activities of D-glucose transport (D-GT) and the glycolytic enzymes hexokinase (HK) and pyruvate kinase (PK), were measured in the erythrocytes of dogs, pigs, cats, horses, cattle and sheep. The erythrocytes of dogs had the highest activities of D-GT, HK and PK, significantly higher than the activities in the erythrocytes of the herbivores. The activities of D-GT and HK in cat erythrocytes were significantly lower than in those of dogs. The differences between the activities of D-GT in the erythrocytes of the different species followed the differences in activities of HK but not those in the activities of PK or in the blood glucose concentrations. It is considered that the activity of HK provides a convenient measurement of the relative rates of glucose oxidation in erythrocytes.

Animals↗
PubMed1995

Proximal paraconal interventricular myocardial bridge in dog: ultrastructural characterization.

The ultrastructure of the dog myocardial bridges (MB), named here the proximal paraconal interventricular-myocardial bridge (PPI-MB), was examined to determine if its structure is identical to that of ordinary cardiac muscle. This study is preparatory to the establishment of PPI-MB as a physical and physiological model system to examine the influence of MB on coronary flow in cardiac function. Five of 46 dog hearts examined possessed PPI-MB, the occurrence of which was independent of sex, age and breed. The dog PPI-MB was localized in a limited area in the proximal third of the paraconal interventricular groove. PPI-MB myocytes and myofibrils were arranged quite straight and smooth, with minimum branching. PPI-MB myocytes formed side-by-side cell junctions through the mediation of mitochondria. Connective tissue elements were involved in terminal cell adhesion to form the myomyous junction beside the intercalated disc. The excitation conductive system of sarcoplasmic reticulum-T tubule often showed a triad. Numerous nerve axons or nerve ending-like structures appeared. Many structural views deviated somewhat from common cardiac muscle structure. This paper represents the first detailed description of PPI-MB muscle.

Animals↗
PubMed1994

Glucose transport and glycolytic enzyme activities in erythrocytes of two-year-old thoroughbreds undergoing training exercise.

D-Glucose transport and cytosolic enzyme activities were measured in erythrocytes from 2-year-old thoroughbreds under continuous training exercise (race horses) and compared with those from untrained horses of various ages (sires, mares and untrained 2-year-old thoroughbreds). The activities of the glucose transport and glycolytic enzymes, hexokinase and pyruvate kinase, in the race horses' erythrocytes were elevated to 2-3.5 times above those of untrained horses. There were no significant differences in plasma glucose, triglyceride or IRI concentrations between the horses in training and untrained horses. The increases in glucose transport and glycolytic enzyme activities in their erythrocytes are considered to reflect an increased metabolic activity in the race horses resulting from the training exercises.

Animals↗
PubMed1994

Plasma atrial natriuretic peptide in normal calves during the first 10 days of life.

The concentration and molecular form of the plasma atrial natriuretic peptide (ANP) in normal calves during the first 10 days of life were investigated. The mean (SEM) ANP concentration on the day of birth was 62.7 (5.52) pmol litre-1, and thereafter it decreased progressively and significantly (P < 0.001). After 10 days, the plasma ANP concentration had decreased to normal adult values (11.3 [3.87] pmol litre-1). On the day of birth and 10 days later a single peak corresponding to alpha-ANP alone was detected in the plasma of the calves.

Aging↗
PubMed1994

Primary small cell carcinoma of the larynx.

Small cell carcinoma is a rare tumor of the larynx. We present such a case in a 78-year-old female. The histopathological diagnosis at the time of laryngomicroscopic biopsy was squamous cell carcinoma, upon which basis we initially chose surgical treatment. The surgical specimen, however, revealed small cell carcinoma. Despite the administration of radiotherapy and chemotherapy, the patient died 9 months after initial presentation. We believe that this case illustrates the need for a sufficiently large biopsy specimen in order to arrive at the correct histopathological diagnosis when small cell carcinoma of the larynx is present, and that immunohistochemistry and electron microscopy should be performed to aid the diagnosis.

Aged↗
PubMed1994

Measurement of staphylokinase by enzyme-linked immunosorbent assay using monoclonal antibodies.

Hybridoma clones producing monoclonal antibodies specific for staphylokinase were isolated. A competitive assay revealed that the monoclonal antibodies studied could be divided into at least two groups. Representatives of these groups, AS22 and B3E6, recognized quite different epitopes on staphylokinase. This finding led us to develop an assay system for the quantitative analysis of staphylokinase by enzyme-linked immunosorbent assay using AS22 as the capturing antibody and biotinylated B3E6 as the "detector". The lower limit of sensitivity of the assay was 20 pg of staphylokinase per ml. The assay exhibited good reproducibility, with values of 5.8 and 3.8% for the intra- and inter-assay coefficients of variation, respectively. Staphylokinase could be assayed in the presence of human plasma when the plasma was diluted more than 320-fold, and the measurement was unaffected by the presence of physiological concentrations of human plasminogen. Hence, this assay was considered useful for the detection and quantification of staphylokinase in clinical samples.

Animals↗
PubMed1994

Effect of change in body position on cardiopulmonary function and plasma cortisol in cattle.

The aim of these studies was to investigate the effect of body posture on circulatory and respiratory system function in unmediated cattle. The plasma cortisol concentration was also measured and served as an indication of the level of stress imposed by animal handling and positional manipulation. Six mature, healthy Holstein cows were physically restrained and studied in standing, supine and right lateral postures. The plasma cortisol concentration increased with the change in body position. In a supine position, the value was increased to more than three times the control value (p < 0.001). The arterial oxygen tension and oxygen saturation were significantly decreased (p < 0.001) with changes in body position. The decrease was most pronounced when cattle were restrained in a supine position. Arterial carbon dioxide tension, heart rate, mean arterial pressure and central venous pressure did not change significantly with changes in body posture. Restraining of cattle in a lateral recumbent or supine position without introducing anesthesia was found to exert a strong stress which affected the respiratory function and increased the plasma cortisol level.

Animals↗
PubMed1994

[Diagnosis of gallbladder cancer by imaging techniques: problems, limitations and their explanations, especially with ss invasive cancer].

The preoperative diagnosis of less than ss depth gallbladder cancer is difficult. Its preoperative diagnosis rate was low (27.5%), and even lower with the presence of concomitant gallstone. In the latter case, the diagnosis rate was particularly low when the stones diameter was greater than 1 cm. Gallstones are frequently associated with macromorphologically invasive type of gallbladder cancer and this may be the reason for the lower diagnostic rate. We compared preoperative diagnosis rate of ultrasonography (US), computed tomography (CT) and drip infusion cholecystography (DIC) for each invasion depth. In US, the preoperative diagnosis rate for m depth invasion was 6/16 (37.5%), pm depth was 1/13 (7.7%), and ss depth was 14/41 (34.1%). In CT, its rate for m depth was 3/11 (27.3%), pm depth was 1/10 (10.0%), and ss depth was 11/37 (29.7%). In DIC, its rate for m depth was 3/11 (27.3%), pm depth was 1/10 (10.0%), and ss was depth 1/23 (4.3%). None of the currently used imaging techniques were very accurate in diagnosing gallbladder cancer. Thus, during preoperative work up, if one discovers a gallbladder full of stones, stones of greater than 1 cm in diameter, thickened gallbladder wall, or a non visualized gallbladder with DIC, gallbladder cancer must be highly suspected.

Cholecystography↗
PubMed1994

Effects of Tamm-Horsfall glycoprotein and albumin on struvite crystal growth in urine of cats.

Tamm-Horsfall protein (THP) was isolated and purified, using pooled urine collections from clinically normal cats. The effects of feline THP and purified feline serum albumin on urine chemical and struvite crystal variables were compared, using an in vitro crystal growth system and 24-hour samples of pooled urine obtained from 4 cats. Urine samples were placed in wells of cell culture plates, increasing concentrations of ammonium hydroxide were added to adjacent wells to stimulate struvite crystal growth, and the plates were incubated at 37 C. The effect of albumin and THP on crystal growth in sample wells was compared with that in control wells, without protein addition, in the same plate. Crystal growth was assessed by determination of number of crystals and supersaturation index, a scale of crystal habit at different degrees of supersaturation, by use of direct visualization with an inverted microscope. Albumin addition did not have significant effect on either crystal number or supersaturation, compared with controls. Addition of THP significantly (P < 0.05) increased crystal number and supersaturation index. It was concluded that THP significantly (P < 0.05) promoted growth of struvite crystals in feline urine, and thus, may have a role in feline struvite uroliths and struvite urethral plug formation.

Ammonia↗
PubMed1992

D-glucose transport activities in erythrocytes and hepatocytes of dogs, cats and cattle.

1. The activities of D-glucose transport and hexokinase were investigated in erythrocytes or hepatocytes of dogs, cats and cattle. 2. The mean D-glucose transport activity in erythrocytes of dogs was 6.0 nmol/min/mg protein, half the value of hepatocytes. 3. The activities of D-glucose transport in erythrocytes and hepatocytes or hepatic hexokinase of cats were about one-third of those of dogs. 4. Cattle with low blood glucose concentrations showed considerably low activities of D-glucose transport and hexokinase, about one-third of those of dogs.

Animals↗
PubMed1992

Silver-induced frog skeletal muscle contraction and its modulation by calcium antagonists nifedipine and felodipine and calcium agonist Bay K 8644.

1. Ag+ induces one phase of a transient contracture in frog skeletal muscle (0.3-10 microM) and potentiates twitch tension when the fiber is given continuous stimulation. 2. The potentiation of fiber contraction by Ag+ is similar to the effect of Ca2+ antagonists nifedipine and felodipine. 3. Bay K 8644 (100 nM) potentiates and accelerates Ag(+)-induced tension development and the inactivation occurs more rapidly than in the control (Ag+ alone). 4. Two factors can be considered to be essential for the induction of Ag+ contracture: (1) a certain number of Ag+ ions must bind to free SH groups of the voltage sensor; and (2) the binding must occur within a limited time to raise the mechanical threshold to induce contracture. 5. All results suggest that Ag+ binding to crucial SH groups on the Ca2+ channel may be responsible for the activation of muscle contraction, potentiation, and the inhibition of excitation-contraction coupling in skeletal muscle.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗