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Biomedical subjects

K Yoshino

Publications and source records attributed to K Yoshino.

At least 19 recordsLinked to original sources
PubMed1992

Dopamine receptor antagonists increase markedly the quantity of retrograde transport of HRP in the rat masseteric motoneuron.

Horseradish peroxidase (HRP) was injected, bilaterally, into the rat masseter muscle, subsequent to an intramuscular or intraperitoneal injection of one of five dopamine antagonists (chlorpromazine and haloperidol as the D1 and D2 receptor antagonist, SCH 23390 as the specific D1 receptor antagonist, sulpiride and domperidone as the specific D2 receptor antagonist). Control rats received an injection of a corresponding vehicle solution. After a survival period of 16 h, the brainstem was cut into 60 microns cryosections and processed with the TMB technique. The amount of retrogradely transported HRP was quantitatively measured in terms of the amount of HRP reaction product present in the motoneuron by the method which we have developed using an image processing system combined with a light microscope and a TV camera. Chlorpromazine, haloperidol, SCH 23390 and sulpiride significantly raised the quantity of retrograde transport of HRP. On the contrary, domperidone which can not penetrate the blood-brain barrier showed no significant change in the amount of the retrograde transport. In addition, an intravenous injection of chlorpromazine (8 mg/kg) was found to increase the amplitude of monosynaptic masseteric reflex EMG activity evoked by stimulations of the mesencephalic trigeminal nucleus. These results suggest that a possible regulatory system involving the dopamine receptor in the uptake and retrograde transport of HRP from axon terminals to cell bodies of the masseteric motoneuron exists in higher order neurons which make synaptic contact with the motoneuron.

Animals↗
PubMed1992

Two classes of receptor specific for sperm-activating peptide III in sand-dollar spermatozoa.

We characterized receptors specific for sperm-activating peptide III (SAP-III: DSDSAQNLIQ) in spermatozoa of the sand dollar, Clypeaster japonicus, using both binding and cross-linking techniques. Analyses of the data obtained from the equilibrium binding of a radiolabeled SAP-III analogueto C. japonicus spermatozoa, using Klotz, Scatchard and Hill plots, showed the presence of two classes of receptors specific for SAP-III in the spermatozoa. One of the receptors (high-affinity) had a Kd of 3.4 nM and 3.4 x 10(4) binding sites/spermatozoon. The other receptor (low-affinity) had a Kd of 48 nM, with 6.1 x 10(4) binding sites/spermatozoon. The Kd of the high-affinity receptor was comparable to the median effective concentration of the intracellular-pH-increasing activity of SAP-III and that of the low-affinity receptor was comparable to the median effective concentration of the cellular-cGMP-elevating activity of the peptide. In addition, Scatchard and Hill plots of the data suggested the existence of positive cooperativity between the high-affinity members. Similar results were also obtained from a binding experiment using a sperm-membrane fraction prepared from C. japonicus spermatozoa. The incubation of intact spermatozoa or sperm plasma membranes with the radioiodinated SAP-III analogue and a chemical cross-linking reagent, disuccinimidyl suberate, resulted in the radiolabeling of three proteins with molecular masses of 126, 87 and 64 kDa, estimated by SDS/PAGE under reducing conditions.

Amino Acid Sequence↗
PubMed1992

Sperm-activating peptide type-V (SAP-V), a fifth member of the sperm-activating peptide family, purified from the egg-conditioned media of the heart urchin Brissus agassizii.

1. A novel type of sperm-activating peptide named sperm-activating peptide type-V (SAP-V) was isolated from the egg-conditioned media (egg jelly) of the heart urchin Brissus agassizii and the primary structure of the peptide was determined by fast atom bombardment mass spectrometry as follows: Gly-Cys-Glu-Gly-Leu-Phe-His-Gly-Met-Gly-Asn-Cys. 2. SAP-V and [Met(O)9]SAP-V stimulated the respiration of B. agassizii spermatozoa with half-maximal concentrations of 0.5 and 0.3 nM, respectively. However, half-maximal stimulation of the sperm respiration required 40 nM of S-carboxymethylated SAP-V. 3. SAP-V induced significant increases in the cyclic AMP and cyclic GMP levels in B. agassizii spermatozoa in a concentration-dependent manner. 4. The addition of SAP-V to B. agassizii spermatozoa resulted in a mobility shift of a major sperm protein (mol. wt from 133,000 to 129,000) on sodium dodecyl sulfate-polyacrylamide gels.

Amino Acid Sequence↗
PubMed1992

Endocrinological environment with regard to the number of microcysts in patients with polycystic ovary syndrome.

Androgen, oestrogen and gonadotrophin levels in patients with the polycystic ovary syndrome (PCOS) were compared with those in normal ovulatory women (controls), and were correlated with the number of microcysts in the polycystic ovaries studied. The androgen levels (testosterone, delta 4-androstenedione and dehydroepiandrosterone-sulphate), oestrogen levels (oestrone and oestrone/oestradiol-17 ratio) and gonadotrophin levels [luteinizing hormone (LH) and LH/follicle stimulating hormone (FSH) ratio] of PCOS patients were significantly higher than those of controls. The number of microcysts in polycystic ovaries was significantly correlated with androstenedione, which in turn was also significantly correlated with LH and LH/FSH ratio. These correlations may play a part in the maintenance of chronic anovulation in PCOS.

Adult↗
PubMed1992

Efficient production of a small peptide by expression as a multimeric form fused with the dihydrofolate reductase affinity handle.

A pentapeptide which potently inhibits primary IgE antibody formation, Asp-Ser-Asp-Gly-Lys (DSDGK), has been efficiently produced with the aid of the dihydrofolate reductase (DHFR) handle [M. Iwakura, et al. (1992) J. Biochem. 111, 37-45]. The genes coding fused proteins comprising DHFR and multimeric forms of DSDGK, namely, DHFR-(DSDGK)3, DHFR-(DSDGK)14, and DHFR-(DSDGK)28, were constructed and expressed in Escherichia coli. The C-terminal peptides attached to DHFR did not affect the expression or the function of the DHFR handle, even when the length of the C-terminal peptide was as long as 160 amino acid residues. The fused proteins were easily purified by methotrexate affinity chromatography, one of the major advantages of the DHFR handle. The fused proteins were digested with trypsin and the monomeric peptide, DSDGK, was purified by HPLC. The yields of the peptide were estimated to be 11, 43, and 99 mg per 1 gram of the total cell proteins from E. coli cells producing DHFR-(DSDGK)3, DHFR-(DSDGK)14, and DHFR-(DSDGK)28, respectively.

Amino Acid Sequence↗
PubMed1992

A unique in vivo assessment of 4-[10B]borono-L-phenylalanine in tumour tissues for boron neutron capture therapy of malignant melanomas using positron emission tomography and 4-borono-2-[18F]fluoro-L-phenylalanine.

A unique in vivo approach to assessing the concentrations of 4-[10B]borono-L-phenylalanine (L-BPA), a melanoma targeting compound for boron neutron capture therapy (BNCT), was investigated using L-BPA labelled with positron-emitting 18F (half-life = 110 min), i.e., 4-[10B]borono-2-[18F]fluoro-L-phenylalanine (L-[18F]FBPA). High melanoma uptake of L-[18F]FBPA was reduced slightly by competition with L-BPA in the two animal models of the murine B16 melanoma and the melanotic Greene's melanoma No. 179 in hamsters. In mice given L-[18F]FBPA and L-BPA, the concentrations of 10B in B16 estimated from 18F radioactivity were lower than those measured by inductively coupled plasma-atomic emission spectroscopy. Lower estimated values were dependent on the time after injection and on the loading dose of L-BPA. The estimated 10B concentrations for Green's melanomas were comparable to the measured values. Positron emission tomography (PET) using L-[18F]FBPA allowed Greene's melanomas to be clearly visualized. In conclusion, when L-[18F]FBPA is used as a probe for L-BPA in BNCT of malignant melanomas, the melanoma can be localized and the 10B concentrations in tissues can be assessed in vivo using 18F radioactivity by PET.

Animals↗
PubMed1992

Second primary cancer following laryngeal cancer with special reference to smoking habits.

The risk of developing a second primary cancer following laryngeal cancer was estimated by following-up 472 male laryngeal cancer patients for an average of 8.6 years by means of record linkage to the Osaka Cancer Registry. Of these patients, 115 developed a second cancer other than laryngeal cancer, whereas the expected number derived from the incidence rates among Osaka residents was 51.4 (relative risk (RR) = 2.2, 95% confidence interval = 1.85-2.69). Cumulative risk of developing a second primary cancer was estimated to be 31.1% at 15 years after laryngeal cancer. By site, the risks were significantly increased for tobacco-related cancers, RR = 24.5, 6.1 and 2.3 for cancers of the oral cavity & pharynx, esophagus and lung, respectively. Also, the risks were higher among heavy smokers for cancer of the oral cavity & pharynx and esophagus than among light smokers. No adverse effects of radiotherapy for laryngeal cancer on the development of thyroid cancer, lymphoma and leukemia were observed. The present study suggests the necessity of following-up laryngeal cancer patients over a long period in order to enable the early detection of tobacco-related cancer.

Adult↗
PubMed1992

Novel disease-modifying antirheumatic drugs. I. Synthesis and antiarthritic activity of 2-(4-methylphenyl)benzothiazoles.

A series of 2-(4-methylphenyl)benzothiazoles was synthesized and evaluated using an adjuvant-induced arthritic rat model. This class of desired compounds affecting the immune response was found using hemagglutination assay. 4-Acetoxy-2-(4-methylphenyl)benzothiazole (7m), KB-2683, was most potent in the adjuvant-induced arthritic rat model and selected for further evaluation. In contrast to nonsteroidal antiinflammatory drugs, compound 7m showed no antiinflammatory or analgesic activities. It did, however, show an immunomodulatory activity in enhanced delayed type hypersensitivity.

Animals↗
PubMed1992

[A review on assessment techniques for workers' physical and mental conditions by physiological measurements].

It was only a several decades ago that physiological measurements were recognized as effective indicators of human physical and mental conditions in occupational health or ergonomics. The recent rapid progress in sensor and signal processing techniques, however, made these available for practical evaluation techniques. This paper is an overview of the accumulated techniques in several fields including experimental psychology, physiology, medical sciences, and ergonomics. The major topics described herein are as follows: 1) properties and merits of physiological measurements compared with the other techniques, 2) applicability of various physiological indicators evaluated from noninvasive, ambulatory and continuous monitoring techniques, 3) practical physiological measurements and signal processing systems which can be applied at actual workplaces and environment, 4) effective and useful evaluation techniques of physiological indicators such as ECG, blood pressure, respiratory parameters, EEG, EBP, EMG, body movements, body temperature, perspiration, eye movements, CFF and electrodermal activities. Our review of 235 published papers has shown that physiological measurements have made a significant contribution to the assessment of physical and mental workload, CNS (central nervous system) activity level and work performance. However, further studies should be made on detail mechanisms and individual variations.

Ergonomics↗
PubMed1992

[Effect of diaphragmatic fatigue on ventilatory response to carbon dioxide].

To clarify the effect of respiratory muscle fatigue on ventilatory response to carbon dioxide, we performed CO2 rebreathing study before and after diaphragmatic fatigue in nine healthy males. Diaphragmatic fatigue was induced by inspiratory resistor loading and confirmed by the increase in Tension Time Index and the decrease in Pdi max at FRC. The effects of diaphragmatic fatigue were as follows: 1) S and B value of VE-CO2 curve did not change. 2) P1-CO2 curve shifted to the left but the slope of the curve did not change. 3) delta Ppl response to CO2 decreased, but delta Pdi response to CO2 did not change. 4) The increase in respiratory accessory muscle EMG was more prominent, compared to diaphragmatic EMG. 5) Rib cage movement became more marked. In conclusion, diaphragmatic fatigue (with 60 percent decrease in Pdi max at FRC) does not affect on ventilatory response to carbon dioxide. To maintain the homeostasis of the chemical ventilatory feedback system, diaphragmatic dysfunction is compensated by the increased activity of respiratory accessory muscles with possible increase in neural drive.

Adult↗
PubMed1992

[Dyspnea and rib cage distortion in postural changes].

We studied the topographical ventilatory motion and electrical muscle activity (EMG) of intercostal muscle within the rib cage for the patients complaining dyspnea produced mostly by their postural changes. There were inappropriateness between the rib cage motion and EMG and this inappropriateness was closely related to a sensation of dyspnea. We could relieve partly dyspnea by applying the negative pressure ventilator, because of prevention of a distortion of rib cage. Based on these clinical observation, we concluded that one of mechanism to sense dyspnea was the inappropriateness between motion and electrical muscle activity within the rib cage.

Dyspnea↗
PubMed1992

Endogenous urinary 3-hydroxyproline has 96% specificity and 44% sensitivity for cancer screening.

A method for determining the endogenous urinary excretion levels of both 3-hydroxyproline and 4-hydroxyproline that may be useful for cancer screening of the general population and at the workplace is evaluated in this report. The excretion levels of 3-hydroxyproline and 4-hydroxproline were estimated in 97 patients with cancer and in 99 patients with various nonmalignant diseases and were compared with those of 211 healthy persons. Measurable 3-hydroxyproline peaks (by amino acid autoanalyzer) were absent from 93 samples from 211 healthy persons (44%), 50 of 99 patients with nonmalignant disease (50%), and 10 of 96 patients with cancer (10%). The levels of both 3-hydroxyproline and 4-hydroxyproline in cancer patients were significantly higher than those in healthy persons (p < 0.001 and p < 0.01, respectively) and those in patients with nonmalignant diseases (p < 0.05 and p < 0.01, respectively). Cancer patients were classified into three groups according to grade of cancer growth and invasion. The sensitivity of 3-hydroxyproline was 44% and higher than that of 4-hydroxyproline for the detection of stage II cancers (no distant metastasis); the sensitivities of both hydroxyprolines for the detection of stage I (very early cancer) were low. The specificity of these assays for healthy persons and patients with nonmalignant disease was 96% and 92% for 3-hydroxyproline, and 97% and 79% for 4-hydroxyproline, respectively. Urinary 3-hydroxyproline level should be further investigated as a cancer screening method for healthy persons in the community or the workplace, but appears unlikely to detect many cancers in the earliest stages.

Adult↗
PubMed1992

[Plasma renin activity and serum aldosterone concentration in severe handicapped patients].

Plasma renin activity (PRA) and serum aldosterone concentration (Ald) were studied in 25 severe handicaps at the rest position. Sixteen cases (64%) showed increased PRA and/or Ald. In four cases treated with acetazolamide PRA or Ald was increased. After suspending this drug in three cases both PRA and Ald decreased significantly. In patients with low-salt-diet (total Na intake; less than 2 mEq/kg/day) PRA was higher than in those with normal-salt-diet (total Na intake; greater than or equal to 2 mEq/kg/day). Alb had no difference in two groups. Urine Na and Cl secretion in patients with low-salt-diet (49.1 +/- 34.1 mEq/l, 43.5 +/- 25.1 mEq/l) were remarkably low when compared to those in patients with normal-salt-diet (113.3 +/- 71.3, 94.2 +/- 56.3). NaCl supplementation in those patients with low-salt-diet for 5 days (total Na intake; 4 mEq/kg/day) resulted in normalization of their high PRA and Ald levels. This phenomenon revealed reversible since suspending NaCl supplementation again increased PRA and Ald levels. These results suggest that both low-salt-diet and acetazolamide play important roles for renin secretion in severe handicaps.

Acetazolamide↗
PubMed1992

[Plasma insulin-like growth factor I in severely handicapped children: usefulness of insulin-like growth factor I in nutritional assessment and dynamics of growth hormone secretion].

Plasma insulin-like growth factor I (IGF-I) was measured in 23 severely handicapped children and compared with that in age-matched controls. Our 23 patients were poorly nourished and remarkably retarded in growth. Serum levels of total protein (TP), albumin (Alb), retinol binding protein and prealbumin in patients were lower than in controls. IGF-I levels in our patients (0.94 +/- 0.72 U/ml) were very low in comparison with those in controls (1.82 +/- 0.72) (p less than 0.01). But urine growth hormones were elevated in most our patients (61.4 +/- 51.7 pg/mg.Cr) (p less than 0.005). When we divided 23 patients into two groups, the low and normal IGF-I group, the low IGF-I group was shorter than the normal IGF-I group. TP and Alb levels were also low. Then we gave 10 patients supplementary protein (0.2-0.7 g/kg/day) for 10-20 days. TP and Alb levels rose in eight of ten patients; TP (g/dl) from 6.5 +/- 0.3 to 7.2 +/- 0.6 (p less than 0.005) and Alb (g/dl) from 4.0 +/- 0.2 to 4.4 +/- 0.3 (p less than 0.01). IGF-I levels (U/ml) rose in nine of ten; from 0.42 +/- 0.33 to 0.68 +/- 0.53 (p less than 0.005). We conclude that IGF-I is a sensitive marker of malnutrition and the nutritional therapy. And high levels of urine growth hormone suggest a normal growth hormone secretion in pituitary glands in most of our severely handicapped children.

Adolescent↗
PubMed1992

Purification of a protein from serum of cattle with hepatic lipidosis, and identification of the protein as haptoglobin.

A protein that has 2 subunits with molecular weight of 35,000 and 23,000 was detected in serum of cattle with hepatic lipidosis (fatty liver). The protein was purified from serum obtained from a cow with fatty liver, and was identified as haptoglobin, which is known to have hemoglobin-binding capacity and to be an acute-phase protein. To assess the relevance of haptoglobin in fatty liver, cattle were classified in 3 groups (healthy control, haptoglobin-positive, and haptoglobin-negative); liver triglyceride content and several serum biochemical variables were evaluated for the 3 groups. Compared with the control and haptoglobin-negative cattle, haptoglobin-positive cattle had significantly (P less than 0.01) higher liver triglyceride content, serum bilirubin concentration, and aspartate transaminase activity. Serum haptoglobin concentration was high in slaughter cattle (27 of 40 cattle tested), particularly in cows (20/28).

Animals↗