Biomedical subjects

A Takeuchi

Publications and source records attributed to A Takeuchi.

At least 91 records · Page 5Linked to original sources

PubMed1996

Histopathological changes in digits of dairy cows affected with sole ulcers.

Forty-eight digits of 8 dairy cows, which had been diagnosed as sole ulcers in one or two hooves, were examined histopathologically and classified into 5 grades on the basis of the severity of the circulatory disturbances and of keratogenesis. All the cows had significantly higher grades than normal cows. Although hind lateral digits were most severely damaged, there were no significant differences in the grades among claw positions except hind lateral digits. From these results, it is suggested that the cows affected with sole ulcers had some systemic factors predisposing all the digits to digital disorders.

Animals↗

PubMed1996

Histopathological findings on ulcerative lesions of carpal and tarsal joints in Japanese black cattle.

In order to determine the pathogenesis of ulcerative lesions of the articular cartilages in Japanese Black cattle, tissue samples of the ulcerative lesion, marginal portion of the ulcer, macroscopically normal portions and synovial membranes were histopathologically examined by light microscopy, scanning electron microscopy and contact microradiography. The results are summarized as follows: (1) In the ulcerative lesions, degeneration and complete destruction of articular cartilage and its replacement with a proliferation of myelogenic connective tissue were observed. (2) In macroscopically normal portions, fissures of the articular surface and changes of the trabecular pattern in subchondral bone were present. (3) In the marginal portions of the ulcerative lesions, evidences of the repair process such as connective tissue growth from subchondral bones and articular cartilages were seen. (4) In synovial membranes, no pathological findings were observed. And (5) among the above mentioned changes, no inflammatory findings were seen. In conclusion, the ulcerative lesions of bovine articular cartilage may be regarded as the early stage of osteochondrosis to osteoarthrosis since the findings such as noninflammatory destruction or degeneration and remodeling of the joints are characteristics of the latter.

Animals↗

PubMed1996

Postparturient change in endotoxin levels of ruminal fluid and serum in dairy cows.

The changes in the endotoxin levels of ruminal fluid and serum in postparturient cows were evaluated. Five cows were fed hay and concentrates on an individual basis (farm A) and the other 5 cows were given complete feed ad libitum (farm B) after parturition. Ruminal pH levels decreased in both groups after parturition. Subsequently, the ruminal endotoxin levels increased with the declining pH on both of the farms. The ruminal endotoxin levels were slightly higher in cows of farm B than those of farm A. Serum endotoxin levels also showed episodic fluctuations, however, there were no parallel changes between the endotoxin levels of the ruminal fluid and sera.

Animals↗

PubMed1996

Primary brain tumors in two dogs treated by surgical resection in combination with postoperative radiation therapy.

Primary brain tumors in two dogs were surgically removed followed by postoperative radiation therapy. The two tumors were confirmed histologically to be astrocytoma and meningioma, respectively. After the surgery, the neurological status of each dog improved dramatically and a total dose of 40 Gy was delivered to the surgical site to treat residual tumor tissue. Although the dog with astrocytoma died 6 months after surgery due to unknown causes, the dog with meningioma has lived for over 24 months with a degree of neurological disorder less severe than that before treatment. These results suggested the effectiveness of this type of therapy on brain tumor in dogs and therapeutic modality should be positively planned to treat canine brain tumors.

Animals↗

PubMed1996

Antitumor activity of natural-type human tumor necrosis factor on experimental brain tumors in rats.

The effects of intralesional injection of newly synthesized natural-type human tumor necrosis factor (nh-TNF) on experimental brain tumors in rats were investigated. The repeated injection of 5,000 U of nh-TNF into the tumor resulted in the prolongation of the survival time of the rats. More than half of the nh-TNF treated tumors were red, and were characterized by histopathological features of marked congestion of tumor vessels. Fibrin formations were also found in the tumor vessels. These histological findings were not observed in the control tumors. Furthermore, coagulative necrosis was observed in the center of some reddish tumors. Leukocytes adhering to vascular endothelium and infiltration of the leukocytes were also observed in the tumors of nh-TNF treated rats. In the immunohistochemical examination, these infiltrated cells were primarily polymorphonuclear leukocytes and macrophages. Expression of intercellular adhesion molecule-1 (ICAM-1) increased on the tumor endothelial cells after the administration of nh-TNF. These results suggest that repeated injection of nh-TNF has a therapeutic effect on brain tumors through its extensive influences on tumor vasculature.

Animals↗

PubMed1996

The source of fluid and protein in serous retinal detachments.

PURPOSE: To investigate the source and protein content of sub-retinal fluid in self-forming experimental serous retinal detachments. METHODS: Detachments were induced in Dutch rabbit eyes using rose bengal photosensitization to cause choriocapillaris injury and thrombosis. Serous detachments formed spontaneously within the next 24 h. Subretinal fluid was withdrawn 2, 8 and 24 hrs after photosensitization, and was analyzed for osmolality and albumin content by gel electrophoresis. RESULTS: The albumin concentration in the subretinal fluid of light-induced detachments was 68% of serum level at 3 h after light damage, and rose close to serum level by 24 h. The osmolality of subretinal fluid 24 h after light damage was essentially the same as serum and vitreous fluid. CONCLUSIONS: The subretinal protein and fluid in light-induced detachments in the central retina of the rabbit must come from the choroid, since there are no intrinsic retinal blood vessels in that region of the fundus. These data demonstrate that serous retinal detachments can form from choroidal fluid.

Albumins↗

PubMed1996

[Evaluation of the clinical usefulness of super dynamic 99mTc-HM-PAO SPECT in ischemic cerebrovascular disease--detection of hypo- and hyperperfusion area].

The purpose of this study is to assess the clinical usefulness of super dynamic SPECT of 99mTc-HM-PAO. Six patients with unilateral occlusion of middle cerebral artery (MCA) or internal carotid artery (ICA) in the chronic phase, and 5 patients with subacute cerebral infarction were studied. We used a ring-type SPECT "HEADTOME." Two types of collimator were used: a high sensitivity (HS) collimator for super dynamic scan and a high resolution (HR) collimator for static scan. First, the intravenous constant infusion of 99mTc-HM-PAO (925-1480 MBq) for 1 minute was started. After 30 seconds from the beginning of the injection, we performed the 12 seconds/frame super dynamic SPECT for 2 minutes. Then, the static SPECT for 10 minutes was done. For semiquantitative analyses, differential percentage of regional activity between affected and non-affected hemispheres was calculated in the 6th frame image of super dynamic SPECT and static SPECT image. In all 6 patients with unilateral occlusion of MCA and ICA, super dynamic SPECT images showed the better contrast of low perfusion areas in comparison with the static SPECT images. In 5 patients with subacute cerebral infarction who showed focal hyperactivities on static SPECT, focal hyperactivities (hyperperfusion or hyperemia) were displayed in 3 cases, whereas, focal hypo- or isoactivities (hypo- or isoperfusion) were shown in 2 cases on super dynamic SPECT. However, all patients with subacute cerebral infarction showed hyperfixation on static SPECT as compared with super dynamic SPECT. Although the image quality on super dynamic SPECT is not as high as that on static SPECT, cerebral hemodynamics would be detected with less backdiffusion of 99mTc-HM-PAO from the brain to blood, and with less accumulation of hydrophilic components in subacute infarct region. In conclusion, super dynamic SPECT in early distribution of 99mTc-HM-PAO using dedicated SPECT device might be helpful to detect cerebral perfusion close to true cerebral blood flow distribution.

Aged↗

PubMed1996

Anesthesia induced in pigs by use of a combination of medetomidine, butorphanol, and ketamine and its reversal by administration of atipamezole.

OBJECTIVE: To develop an IM administrable anesthetic combination for pigs. DESIGN: Use of a combination of atropine, medetomidine, butorphanol, and ketamine (MB-K) was evaluated as an anesthetic regimen and compared with that of a combination of atropine, xylazine, butorphanol, and ketamine (XB-K). Cardiorespiratory effects of MB-K combination and use of atipamezole as a means of reversing anesthesia induced by MB-K were examined. ANIMALS: 18 castrated, mixed-breed, specific-pathogenfree pigs, aged 8 to 15 (mean, 12.1) weeks and weighing 14.5 to 26.0 (mean, 19.6) kg. were studied. PROCEDURE: Dosages of drugs used in this study were atropine, 25 micrograms/kg of body weight; medetomidine, 80 micrograms/kg; xylazine, 2 mg/kg; butorphanol, 200 micrograms/kg; ketamine, 10 mg/kg; and atipamezole, 240 micrograms/kg. RESULTS: MB-K combination proved to be more effective than XB-K combination as an anesthetic combination. After quick and smooth induction by IM administration, MB-K-induced anesthesia was sustained for 98.8 +/- 22.5 minutes (mean +/- SD, 47.4 +/- 16.5 minutes by XB-K) with accompanying muscular relaxation (91 +/- 18 minutes) and loss of pedal (82 +/- 24 minutes) and laryngeal (75 +/- 19 minutes) reflexes. Loss of these reflexes was of significantly longer duration than the loss induced by XB-K, enabled tracheal intubation, and, thus, supported major surgery for at least 30 minutes after induction. Recovery from MB-K-induced anesthesia was smooth. MB-K combination had a slight stimulative effect on cardiovascular status, and a significant depressant effect on blood gas and acid-base status, but these effects were within biologically acceptable limits. Oxygen consumption of pigs under MB-K-induced anesthesia decreased significantly. MB-K-induced anesthesia could be effectively and quickly reversed by IM or IV administration of atipamezole. CONCLUSIONS: The combination of medetomidine, butorphanol, and ketamine induces excellent surgical anesthesia in pigs, and results in moderate cardiorespiratory effects. A great advantage of the anesthetic regimen is that it can be effectively and quickly reversed by atipamezole. CLINICAL RELEVANCE: Medetomidine, butorphanol, and ketamine-induced anesthesia is available for short-term major surgery in pigs.

Adrenergic alpha-Antagonists↗

PubMed1996

[Retroperitoneal ganglioneuroma: a case report].

We experienced a case of ganglioneuroma. A 37-year-old man was admitted to our hospital for right flank pain. Computed tomography (CT) showed a low density mass near the upper pole of the right kidney. Selective renal arteriography did not demonstrate any tumor vessels in the right kidney. An endocrinological study revealed high values of noradrenaline and dopamine in urine. Under the preoperative diagnosis of a retroperitoneal tumor or right adrenal tumor, tumor resection was performed. The tumor was found in the retroperitoneal space on surgical exploration. The histopathological diagnosis was ganglioneuroma.

Biomarkers, Tumor↗

PubMed1996

Asymptomatic acute poststreptococcal glomerulonephritis following upper respiratory tract infections caused by Group A streptococci.

During an observation period of 1-2 years in 2 different districts in Japan, 104 patients were found to have upper respiratory infections caused by group A streptococci. Fourty-nine of these patients were followed prospectively to determine if renal involvement would occur. Twelve patients developed transient serum complement (CH50) depression and urinary abnormality, and 2 of these developed mild hypertension. The latent period was from 1-8 weeks after the streptococcal infection. Renal biopsies of the 12 patients with "asymptomatic" of "subclinical" acute poststreptococcal glomerulonephritis (APSGN) were examined by light, immunofluorescent and electron microscopy. Glomerular lesions ranged from mild proliferative changes to the classical pathology seen in APSGN. The 12 patients were followed for 10 years. Two of them developed persistent or intermittent hematuria, and renal biopsies obtained 4 years after the initial infection revealed mesangial proliferative glomerulonephritis without IgA deposits. The remaining patients showed no abnormal findings after the acute episode. These findings suggested that glomerular involvement after group A streptococcal infection is frequent and mesangial proliferative glomerulonephritis, which was found to develop in some, may rank with IgA nephropathy as a major cause of unexplained microscopic hematuria.

Acute Disease↗

PubMed1995

The distribution of TM-316-associated surface antigen on polymorphonuclear leucocytes: an immunoelectron microscopic study.

It has been established that MoAb TM-316 recognizes an epitope on leucocytes and specifically inhibits the chemotactic behavior of leucocytes. In the present paper, the distribution of this epitope on the cell surface and in intracellular organelles was studied by immunoelectron microscopy. Leucocytes separated from the blood of healthy men and from synovial fluid from patients suffering from rheumatoid arthritis were used. They were fixed with a mixture containing paraformaldehyde, glutaraldehyde and picric acid. As the second antibody, goat anti-mouse IgM conjugated to 10 nm gold colloids was employed. In normal specimens, the epitope was found to some extent on the cytoplasmic membrane of neutrophilic leucocytes, but it was only sparsely distributed on eosinophilic and basophilic leucocytes. On activated neutrophilic leucocytes, obtained from the synovial fluid of rheumatoid arthritis patients, the immunolabeling was markedly increased. The number of sites where the epitope occurs on the surface of leucocytes is thus associated with the cell type, and also with the level of activation of the leucocytes. In order to investigate the processing of the antigen, the intracellular localization of the epitope in the neutrophilic leucocytes was also studied. The epitope recognized by TM-316 was also detected in/on the characteristic granules and Golgi stacks.

Antigens↗

PubMed1995

A human erythrocyte-derived growth-promoting factor with a wide target cell spectrum: identification as catalase.

We have reported previously that a factor with a molecular weight of 53,000 under SDS-polyacrylamide gel electrophoresis purified from human erythrocyte extracts promoted the growth of a wide variety of cell types from different species, including T cells, B cells, myeloid leukemia cells, melanoma cells, and mastocytoma cells, as well as normal and transformed fibroblast cells. In the present study, amino acid sequence analysis revealed that this factor has homology with human catalase. The purified factor exhibited catalase activity. Catalases derived from human erythrocytes, bovine liver, Aspergillus niger, and recombinant rat liver catalase are all able to promote the growth of cells. Antibody against human catalase absorbed both the growth-promoting activity and the enzyme activity of the purified factor. In addition, treatment of the factor with an irreversible enzyme inhibitor, aminotriazole, resulted in abrogation of both the growth-promoting activity and enzyme activity. These results indicate that the growth-promoting factor is catalase, and its activity is associated with the decomposition of hydrogen peroxide.

Amino Acid Sequence↗

PubMed1995

Chemical restraint by medetomidine-ketamine and its cardiopulmonary effects in pigs.

Chemical restraint induced by medetomidine-ketamine (M-K) combination was evaluated compared with that by xylazine-ketamine (X-K) in pigs. The duration of restraint by M-K was 49.4 +/- 13.5 min (mean +/- SD) and longer than that by X-K (34.6 +/- 17.2 min), but the difference was not significant. The effect of X-K was not stable, since one of five pigs was restrained only for 6 min. Both combinations produced muscle relaxation. The duration of muscle relaxation in M-K was 43.6 +/- 12.7 min and was significantly longer than that in X-K (21.0 +/- 14.0 min). M-K combination had a slightly stimulative effect on the cardiovascular system, but scarcely changed the respiratory parameters. This limited effect on cardiopulmonary system was an advantage of M-K combination for chemical restraint in pigs. These results indicated that M-K combination is suitable for chemical restraint with prolonged muscle relaxation and has limited cardiopulmonary effects in pigs.

Anesthetics↗

PubMed1995

Pharmacological activity of the C-terminal and N-terminal domains of secretory leukoprotease inhibitor in vitro.

1. In order to characterize the physiological functions of the domain structure of secretory leukoprotease inhibitor (SLPI), the biological capacities of half-length SLPIs, (Ser1-Pro54)SLPI and (Asn55-Ala107)SLPI, were investigated and compared with those of full-length SLPI. 2. The activities of these inhibitors against several serine proteases were determined using synthetic chromogenic substrates. The inhibitory capacity of the C-terminal domain, (Asn55-Ala107)SLPI, was as strong as that of full-length SLPI against human neutrophil elastase (NE), cathepsin G and chymotrypsin. It possessed less trypsin inhibitory activity than intact SLPI. For the N-terminal domain of SLPI, (Ser1-Pro54)SLPI, no inhibitory activity could be detected against the serine proteases tested in this study. 3. The inhibitory activity of (Asn55-Ala107)SLPI against the proteolysis of the natural substrates elastin and collagen by NE was comparable with that of full-SLPI (elastin, IC50 = 907 +/- 31 nM for SLPI, 767 +/- 33 nM for (Asn55-Ala107)SLPI; collagen, IC50 = 862 +/- 36 nM for SLPI, 727 +/- 47 nM for (Asn55-Ala107)SLPI). 4. The binding affinities of full- and half-length SLPIs for heparin were measured by affinity column chromatography. Full-length SLPI showed high affinity for heparin while the binding capacities of both half-length SLPIs were lower. (Concentration of NaCl for elution, 0.45 M for SLPI, 0.24 M for (Ser1-Pro54)SLPI, 0.27 M for (Asn55-Ala107)SLPI). 5. The effects of full-SLPI and (Asn55-Ala107)SLPI on blood coagulation were measured using the activated partial thromboplastin time (APTT). Full-length SLPI prolonged clotting time dose dependently(1.25, 2.5 and 5.0 microM), whereas (Asn55-AlalO7)SLPI had no effect even at the highest concentration.6. In conclusion, the C-terminal domain of SLPI is a promising candidate for the treatment of inflammatory diseases in which participation of neutrophil proteases has been suggested.

Animals↗

PubMed1995

Periodic high extracellular glucose enhances production of collagens III and IV by mesangial cells.

We examined the effects of periodic changes in extracellular glucose concentration on matrix production and proliferation using three groups of cultured rat mesangial cells (MCs): 1) MCs in medium with continuous 5 mM glucose (CL), 2) MCs in medium alternating daily between 5 and 25 mM glucose (PH), and 3) MCs in medium with continuous 25 mM glucose (CH). MCs cultured in PH for 10 days produced 329 and 110% more type III collagen protein than MCs cultured in CL and CH, respectively. MCs cultured in PH induced 31 and 14% more type IV collagen than MCs cultured in CL and CH, respectively. Extracellular glucose concentration had no effect on the amount of type I collagen produced. MCs cultured in PH or CH for 5 days also expressed increased levels of type I, III, and IV collagen mRNA compared with MCs cultured in CL. MCs cultured in PH for 8-10 days also produced significantly more DNA than MCs in CL or CH. These data suggest that the temporal pattern of exposure to high extracellular glucose plays a role in regulating matrix formation and cellular proliferation by MCs. Furthermore, periodic elevations of extracellular glucose had a greater stimulatory effect on collagen production than a sustained elevation. These results suggest that decreasing the variability of blood glucose concentration may decrease the adverse effect of elevated glucose levels on MC matrix production and the progression of diabetic glomerulopathy.

Analysis of Variance↗

PubMed1995

Effects of yohimbine and desipramine on adrenal catecholamine release in response to splanchnic nerve stimulation in anesthetized dogs.

The effects of yohimbine and desipramine on adrenal catecholamine (CA) release in response to splanchnic nerve stimulation (SNS) were examined in anesthetized dogs. SNS and 3 Hz produced frequency-dependent increases in epinephrine (EPI) and norepinephrine (NE) output determined from adrenal venous blood. Yohimbine (30 and 100 micrograms/kg, i.v.), a selective alpha 2-adrenoceptor antagonist, enhanced the SNS-induced increases in both EPI and NE output. Desipramine (100 and 300 micrograms/kg, i.v.), an amine pump inhibitor, enhanced the SNS-induced increases in NE output, whereas no enhancement of EPI output was produced. After desipramine treatment, yohimbine further enhanced the SNS-induced increases in EPI and NE output. After yohimbine treatment, desipramine further enhanced the SNS-induced increase in NE output. These results suggest that the release of adrenal CA in response to SNS is inhibited by alpha 2-adrenoceptors, and that released NE, rather than EPI, is predominantly taken up into the dog adrenal medullary cells.

Adrenal Glands↗

PubMed1995

Cloning of canine osteosarcoma cells.

Six clonal cells were established from a canine osteosarcoma cell line (POS) by a limiting dilution method using feeder cells. Whereas histology of mass developed in nude mice by transplantation of POS cells revealed various cell types, clonal cells were morphologically consistent in size and shape. Doubling time of clonal cells ranged from 30 +/- 1.4 to 54 +/- 1.3 hr and alkaline phosphatase activity ranged from 0.040 +/- 0.001 to 2.61 +/- 0.435 mumol/min/mg protein depending on the cell types. When transplanted into nude mice, each clonal cell type formed following four histological types; osteoblastic, chondroblastic, fibroblastic, and undifferentiated types. Since each histological feature was found simultaneously in the primary tumor, osteosarcoma tissue might be a complex of various types of cells having different characteristics. Therefore, POS clonal cells may be useful as a potential tool for the studies of differentiation, phenotypic expression, and a new therapeutic modality of osteosarcoma.

Alkaline Phosphatase↗

PubMed1995

The antitumor activity of the DNA fraction from Mycobacterium bovis BCG (MY-1) for glioblastoma.

The antitumor activity of the DNA fraction extracted from Mycobacterium bovis BCG (MY-1) for glioblastoma was investigated in the experimentally produced brain tumor in rats. The tumor-bearing rats were given intralesional injection of 1 mg of MY-1 twice a week for three weeks, and were sacrificed for comparison with those of control rats. The main macroscopic features of the tumors treated with serial injections of MY-1 were cystic and destructive structures, which were histologically characterized by multiple microcysts containing macrophages. Furthermore, infiltration of leukocytes as well as the perivascular cuffing in the marginal area was observed. These findings suggested that the serial injections of MY-1 into the brain tumor have the therapeutic potential for glioblastoma.

Animals↗