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Biomedical subjects

M Takeishi

Publications and source records attributed to M Takeishi.

52 records · Page 3Linked to original sources

Efficacy of ivermectin against live mites and eggs of Sarcoptes scabiei in pigs.

Sows infested with Sarcoptes scabiei var. suis (ssvs) were treated with 75, 150 and 300 micrograms/kg of ivermectin by a single subcutaneous injection at the neck region. Compared to the numbers of mites and eggs just before injection, those on post treatment weeks (PTW) 1, 2 and 4 showed significant decreases. Especially at 300 micrograms/kg, the counts showed almost all mites and eggs were eradicated on PTW 1, manifesting ivermectin to possess potential effect on ssve without apparent abnormal side effect. Potential mitocide effect of ivermectin on ssvs was revealed.

Animals↗

Cross-reactivity between human and canine helper and suppressor T cell antigens using monoclonal antibodies RPA-T4 and HuLy-m8.

The murine monoclonal antibodies RPA-T4 and HuLy-m8, specific for a framework determinant of human helper/inducer and suppressor/cytotoxic T cell antigens, cross-reacted with canine cell membrane molecules recognizing a biomolecular complex (50,000 to 55,000 daltons) similar to that described in humans. We investigated the distribution of these helper and suppressor T cell-like antigens on canine peripheral blood lymphocytes. With complement-mediated lymphocytotoxicity, 34% and 35% of the canine lymphocytes expressed the helper T cell-like antigens and the suppressor-like T cell antigens, respectively. When the lymphocytes were treated with RPA-T4 and HuLy-m8, the respective helper and suppressor function was significantly inhibited.

Animals↗

Expression of interleukin-2 receptor (IL-2R) in feline peripheral blood lymphocytes.

A monoclonal anti-interleukin-2 receptor (IL-2R) antibody has been identified as a putative antibody against the human IL-2R. In the present study, anti-Tac antibody CD-25 was used to determine cell expressing IL-2 receptor in feline peripheral blood lymphocytes by means of direct immunofluorescence tests and complement-mediated lymphocytotoxicity tests. With complement-mediated lymphocytotoxicity, approximately 18% of feline peripheral blood lymphocytes expressed the receptors. By the direct immunofluorescence test, we found approximately 22% of IL-2R positive cells in lymphocytes of feline peripheral-blood.

Animals↗

Cross-reactivity between human and feline Ia antigens, using a monoclonal antibody HLA-D.m1.

A murine monoclonal antibody HLA-D.m1 produced against human Ia antigens which react with 10% to 30% of human peripheral-blood mononuclear cells was found to react with greater than 90% of feline mononuclear cells. The antigen was not expressed on granulocytes. By direct immunofluorescence, 7% to 41% of feline lymphocytes expressed surface immunoglobulins. In mixed-lymphocyte reaction, the addition of antibody HLA-D.m1 to cultures abolished proliferation. These studies indicate that most feline peripheral-blood mononuclear cells express Ia-like antigens.

Animals↗

Characterization of feline T and B cells.

Feline peripheral-blood lymphocyte populations (n = 22) were examined for the following markers: rosette formation with guinea pig erythrocytes (GPE-T cells), rosette formation with human RBC (HRBC-T cells), rosette formation with sheep RBC, mixed rosette formation with GPE-T cells and HRBC-T cells (total T cells), erythrocyte antibody-complement rosettes, and surface immunoglobulin. An average of 28% +/- 7% (range, 16% to 39%) of the feline lymphocytes formed rosettes with GPE-T cells, and 27% +/- 7% (range, 11% to 36%), with HRBC-T cells. An average of 57% +/- 9% (range, 33% to 75%) of the lymphocytes formed mixed rosettes. The erythrocyte antibody-complement rosette-forming cells and surface immunoglobulin-bearing cells were found in peripheral blood lymphocytes (10% +/- 6% and 24% +/- 8%, respectively). The murine monoclonal antibodies OKT 11 and HuLy-m1, specific for a framework determinant of human E-rosette receptor antigens, cross-reacted with feline cell membrane molecules recognizing a bimolecular complex (45,000 to 50,000 daltons) similar to that described in persons. We investigated the distribution of these E-rosette receptor-like antigens on feline lymphocytes. By complement-mediated lymphocytotoxicity, about 30% of the feline lymphocytes expressed the antigens. When lymphocytes were treated with HuLy-m1 antibody, spontaneous rosette formation with HRBC-T cells was significantly inhibited.

Animals↗

New theory on the pathogenesis of acute myocardial infarction.

Autopsy studies of hearts from 140 patients who had suffered acute myocardial infarction (AMI) and 26 cases of sudden coronary death revealed two distinct types of myocardial cell death: "kinetic cell death" (KD) and "static cell death" (SD). In KD, the predominant type of cell death in AMI-myofibrils disintegrated through alternating overcontraction and overextension. KD was found not only in patients having died after some time had elapsed from the onset of AMI, but also in cases of sudden coronary death. Muscle fibers in SD, which by contrast began to appear at least seven hours after the onset of AMI, characteristically preserved cross striations, while their nuclei were pyknotic or had already disappeared. Such fibers were observed only in territories peripheral to occlusive coronary thrombus, a secondary rather than a primary event that takes place during the course of AMI. As a result of the above observations, we were able to produce a new experimental model of AMI using mongrel dogs. As a preparatory procedure we first injected them intravenously with 2% calcium chloride at a constant rate for 90 or 120 minutes, and then with a sudden injection of caffeine, calcium chloride and catecholamine in order to induce KD. In contrast, ligation of the intraventricular coronary artery near its origin caused SD of myocardial fibers in the dependent territories. Overall results led us to conclude that AMI is initiated by instantaneous overcontraction of myocardial fibers, resulting in their KD, a phenomenon that could be called "myocardial self-destruction."

Adult↗

Dimensional changes of tissues in the course of processing.

Dimensional changes of bovine kidney and liver tissues in the course of processing under four different schedules were measured. Shrinkage of tissues at dehydration, substitution with intermedium and paraffin infiltration stages was 1-2%, 2-5% and 5-10% respectively. There was no significant difference in final dimension and morphology among the specimens processed under the different schedules. Any one of the investigated schedules can be employed for practical tissue processing.

Animals↗

Studies of body movements during night sleep in infancy.

Body movements (BMs) during night sleep of 25 neurologically normal infants, 11 premature and 14 full-term, whose ages ranged from 30 conceptional weeks to 18 months post-term, were examined to evaluate the changes of their features with age. The examinations performed during sleep periods totaled 65 times, 1 to 60 times on each subject. Through visual observation and EEG recordings, the BMs were classified into 3 types: (1) Gross movements (GM), (2) localized movements (LM), both of the above two lasting more than 0.5 second, and (3) twitch movements (TM) lasting less than 0.5 second. Total GM and LM time per hour of sleep, average duration of GM and LM and number of GM, LM and TM per hour of sleep were calculated. Percentage of 20 seconds epochs without BMs (nonbody-movement-epochs) was also estimated. These BMs parameters decreased with maturation to certain low base levels. However, each parameter showed a particular time course. TM decreased initially, then LM and lastly GM reached the base level around the age of 9 to 13 months. On the other hand, nonbody movement-epochs increased progressively until 8 months of age. These three types of BMs are considered to be controlled by the CNS with different organization levels, the simplest for TM and the most complicated for GM. They are thus correlated to the maturational process of the CNS, and could be good indicators for detecting normal and abnormal CNS developments.

Age Factors↗

Substrate specificities of acid kininogenases.

Two kinin forming enzymes were extracted from bovine spleen and separated from cathepsin B1 and B2 by DEAE-Cellulose chromatography. Since these catheptic kininogenases were found to release kinins from kininogens at acidic pH's, these were named acid kininogenase I and II. The presence of SH compounds was not necessary for I to have a kinin forming activity, while it was necessary for II. These have only minor difference for electrophoretic behaviors as can be seen, e.g., from a small difference in pI values, but could be separated by polyacrylamide gel electrophoresis. Their production of kinins from bovine crude bradykininogen was highly reproducible. Kininogenase I was proved to react on bovine HMW kininogen and also to release some kinin from LMW kininogen and leukokininogen. From the study of several substrates, these enzymes were revealed to have very low tryptic and little esterolytic activities and to have affinity to some hydrophobic amino acids.

Amino Acid Sequence↗

Self-mutilation and sleep stage in the Lesch-Nyhan syndrome.

Correlation of self-mutilation and sleep stage in the Lesch-Nyhan syndrome was studied by a polygraphic method. Five patients and three control boys were monitored with EEG, EOG, EMG, ECG and respiration throughout the night. The results were as follows: 1. The sleep-time of the patients was much disturbed during the night. 2. Decreased REM density was noticed with low DQ of the patients. 3. Self-mutilation during sleep-time was observed a lot in stages 1, 2, and REM in two cases. 4. No correlation was observed between body movement and self-mutilation in the Lesch-Nyhan syndrome. These data suggested functional disorders of the frontal lobe in the patients.

Adolescent↗

[Myocardial sarcoidosis--pathological studies on 7 autopsy cases with particular reference to histological variations].

The present report consists of seven autopsy cases of myocardial sarcoidosis terminating in death 1 month to 5 years after the onset of symptoms. Histologically, they were classified into the following 4 types: a) diffuse nonspecific granulation, b) specific granuloma with giant cells, c) diffuse fibrosis with giant cells, and d) nonspecific fibrosis. Types a) and b) demonstrate active changes, while c) and d) are sequelae of active inflammation. Morphological changes of sarcoidosis were found not only in myocardium but also in both pericardium and endocardium. Although no final conclusions could be obtained as to whether the giant cells appearing in myocardium were of mesenchymal or myogenic origin, the authors favor the latter concept. Changes compatible to sarcoidosis found in other organs in acute cases were scarce and old. On the contrary, more active and variable changes were encountered in protracted cases. The authors consider giant cell myocarditis to be one type of sarcoidosis occurring in the heart.

Adult↗

Determination of optimal time for mating by artificial insemination with chilled semen using luteinizing hormone surge as an indicator in beagles.

Artificial insemination (AI) was conducted using the second fraction of semen, which was collected from 15 male dogs, diluted to a total sperm count of 100x10(6) for each insemination with egg-yolk Tris (eyT) citrate acid buffer and incubated at 4 degrees C for 48 hours. Luteinizing hormone (LH) surge was detected to determine the optimal time for mating using canine LH assay kits. Artificial insemination using 100x10(6) sperm was performed on the fourth and sixth days or the fifth and seventh days after the LH surge. The conception rates were 33% (4/12) and 89% (8/9), respectively; the whelping rates also showed similar results. Serum LH and follicle stimulating hormone (FSH) concentrations were measured in nine dogs, and the mean LH concentration (+/- standard deviation) at LH surge was 15.77+/-7.66 ng/ml. The time of the LH surge detected by the canine LH assay kit was very similar to that measured by radioimmunoassay (RIA).

Animals↗

Shrinkage in the horizontal dimensions of the vulva (vulvar shrinkage) as an indicator of standing heat in the beagle.

During the proestrous and estrous periods in 12 beagles, the following parameters were measured daily: the horizontal dimensions of the vulva, vaginal cytology, and serum luteinizing hormone (LH) and progesterone concentrations. Measurements of serum LH concentrations allowed for the identification of the LH surge and the optimal time for artificial insemination (AI). Nine out of the 12 beagles became pregnant through AI and completed a gestation. Shrinkage in the horizontal dimensions of the vulva (i.e., vulvar shrinkage) was primarily observed prior and subsequent to the LH surge. In six of the nine (66.7%) beagles that became pregnant, vulvar shrinkage was observed on the days in which the LH surge was confirmed, and the rate of vulvar shrinkage tended to be greater at higher serum LH concentrations. Further vulvar shrinkage was identified in all nine beagles within two days of the LH surge. An increase in the serum progesterone concentration was observed after the LH surge in each of the beagles that became pregnant, together with clinical signs of estrous behavior (i.e., standing heat) as well as a change in vulva condition from swollen to soft. This demonstrates that vulvar shrinkage is induced in response to the onset of the LH surge and that the LH surge can be predicted through the measurement of the horizontal dimensions of the vulva, vaginal cytology, and the assessment of serum progesterone concentrations in beagles.

Animals↗