Biomedical subjects

A Takagi

Publications and source records attributed to A Takagi.

390 records · Page 22Linked to original sources

PubMedDate not supplied

Muscle pathology in polymyalgia rheumatica: histochemical and immunohistochemical study.

Immunohistochemical studies were performed on muscle biopsy specimens of polymyalgia rheumatica (PMR) to evaluate the extent of muscle and peripheral nerve involvement. The routine histochemistry revealed a mild variation of fiber size, type 2 fiber atrophy and type 2A or 2B fiber deficiency. In 63% of the PMR cases small angular fibers, pyknotic nuclear clumps or target-targetoid fibers were observed, suggesting neurogenic changes, although abnormalities were mild in degree. In immunocytochemical studies, neither major histocompatibility complex (MHC) class 1 nor class 2 products were expressed on the muscle surface membrane of PMR. But regarding intramuscular vessels, MHC class 2 products were distinctly visualized. On serial sections, combined deposits of IgG and Clq in perimysial arteries were seen in 38% of PMR. These results suggest that arteries of small caliber might be involved in immunopathological processes, causing muscle and peripheral nerve damage.

Aged↗

PubMedDate not supplied

Computer-aided three-dimensional reconstruction and measurement of semicircular canals and their cristae in man.

We studied the spatial relations of the semicircular canals (SCCs) and their cristae, by computer-aided three-dimensional reconstruction, a graphic method we developed. The angles between pairs of SCCs, between pairs of SCC cristae, and between a SCC and its crista were measured using histology sections of a normal temporal bone from a 14-year-old female. Angles between pairs of SCCs and pairs of cristae deviated 11.3 to 18.2 degrees and 4.8 to 18.0 degrees, respectively, from right angles and the long axis of each crista deviated 25.0 to 30.4 degrees from the line perpendicular to the plane of the corresponding SCC; thus none of these structures lies at a right angle to another. We believe these new anatomical findings will help in the clinical evaluation of SCC function.

Adolescent↗

PubMedDate not supplied

Lack of evidence for expression of Fas ligand in Fas-bearing tumors.

Interaction of Fas and its ligand plays an important role in the cell death by means of apoptosis in a variety of cell types. We recently demonstrated the frequent expression of Fas in female reproductive tract tumors, which prompted us to examine the local production of Fas ligand by the Fas-bearing tumors. Human endometrial and ovarian carcinomas, surgically removed, were studied. No expression of Fas ligand messenger ribonucleic acid (mRNA) as assessed by reverse transcription-polymerase chain reaction using oligonucleotide primers according to published sequences were observed; Fas ligand mRNA was detected in lymphocytes. Immunoblotting of membrane proteins with the specific antibody failed to demonstrate any substantial level of immunoreactive Fas ligand in these tumors. The results for both mRNA expression and immunoreactivity suggest that human ovarian and endometrial carcinomas lack the Fas ligand. The demonstration of absence of Fas ligand expression raises the possibility that the stimulated proliferation of the Fas ligand-absent tumors may occurs by release of Fas-Fas ligand system-associated apoptosis.

Apoptosis↗

PubMedDate not supplied

Alternative gonadotropin-releasing hormone processing products secreted from endometrial carcinoma.

Gonadotropin-releasing hormone (GnRH) receptor is demonstrated in uterine endometrial carcinoma. The endometrial carcinoma also produces GnRH or -like peptide, which prompted us to examine whether the intratumoral serves as natural ligand for its receptor. Endometrial carcinomas surgically removed had been screened for GnRH receptor expression before analysis. The in endometrial carcinoma cell-enriched culture media was characterized by immunoblots in tricine-supplied electrophoresis system and subsequent amino acid sequencing. Three major proteins of 10.0 kDa, 7.6 kDa and 1.1 kDa corresponding to pre-proGnRH, proGnRH and decapeptide GnRH, respectively, were detected in all of the ten endometrial carcinoma specimens tested. Immunoreactive contents in the culture media, assessed by RIA, ranged from 0.08 to 0.1 nM. In chorionic cell-conditioned media, only 1.1-kDa protein was detected. Endometrial carcinoma cells secrete alternative GnRH processing products in addition to natural GnRH. The GnRH variants may compete with mature GnRH at the level of its receptors, perhaps counteracting the GnRH signaling pathway to retard cell proliferation.

Culture Media↗

PubMedDate not supplied

[Effect of caffeine on tension development of skeletal muscle of mdx mouse].

Among various pharmacological actions of caffeine upon the skeletal muscle, activation of the contractile system by Ca2+ is also influenced by caffeine. So far the effect of caffeine upon the contractile system is not properly studied in pathological muscle specimens. Using the skinned muscle fiber, we compared the effect of caffeine between control and dystrophic (mdx) mouse muscle. In lower Ca2+ (-5 microM), tension generation increased with caffeine. A maximum tension generation in higher Ca2+ (10-30 microM) was suppressed by 30 mM caffeine. In comparison between control and mdx type 2 muscle fiber, tension with caffeine was always more in mdx. On the other hand, modification by 5 mM caffeine was the same between control and mdx type 1 fiber of the soleus muscle. Different responses to caffeine between control and mdx type 2 fiber might be related to prevalent degenerative or regenerative processes. But exact mechanism is not clear yet. Currently, contracture by caffeine or halothane is applied in diagnosis of malignant hyperthermia (MH). Present observations suggested that influence of caffeine on the contractile system constituted one of causes for unspecific results in cases with concurrent neuromuscular diseases.

Animals↗

PubMedDate not supplied

Changes of 8-hydroxydeoxyguanosine levels in rat organ DNA during the aging process.

We investigated the accumulation of oxidative DNA damage during the aging process by using 8-hydroxydeoxyguanosine (8-OH-dG) as a marker. The 8-OH-dG is one of the oxidative DNA damage products and is supposed to be a critical factor in carcinogenesis involving oxygen radicals. The 8-OH-dG levels in the DNA of liver, kidney, brain, lung, and spleen were measured in male and female F344 rats 6- to 30-month-old. The 8-OH-dG levels in the liver and kidney DNA of male rats increased significantly with age, but did not change in brain, lung, and spleen. Similarly, the 8-OH-dG levels in the liver and kidney DNA of female rats significantly increased with age, while changes in the brain, lung, and spleen DNA were much smaller. These results indicate that the accumulation of oxidative DNA damage during the aging process varies among organs, with slight sex difference.

8-Hydroxy-2'-Deoxyguanosine↗

PubMedDate not supplied

Hepatomegaly is an early biomarker for hepatocarcinogenesis induced by peroxisome proliferators.

The relationship between hepatomegaly and the hepatocarcinogenesis associated with by peroxisome proliferators was examined. (1) Male F-344 rats were maintained on diets containing clofibrate, ciprofibrate, nafenopin, gemfibrozil, Wy-14, 643, di(2-ethylhexyl)phthalate (DEHP), or di(2-ethylhexyl)adipate (DEHA) at carcinogenic doses for 1 week. A close correlation between relative liver weights and hepatocarcinogenicity was observed (r = 0.910). (2) Administration of perfluorooctanoic acid (PFOA), perfluorodecanoic acid (PFDA), simfibrate, or DL-040, for which hepatocarcinogenicity is not known, resulted in hepatomegaly in all treated groups, this being especially marked in the PFOA case. Therefore, PFOA may have strong hepatocarcinogenic potential. (3) Administration of the antioxidants butylated hydroxyanisole (BHA) or vitamin E (VE) did not affect the hepatomegaly induced by DEHP. These results suggest that the hepatomegaly may be an early biomarker for prediction of the potential hepatocarcinogenicity of peroxisome proliferators. However, this requires further clarification in terms of its relation to the oxidative stress thought to be involved in peroxisome proliferator-induced hepatocarcinogenesis.

Animals↗

PubMedDate not supplied

Carotid artery pseudoaneurysm following internal jugular vein cannulation.

A case of right common carotid artery pseudoaneurysm following internal jugular vein cannulation is reported. The aneurysm appeared three days after removal of the catheter, which had been in the right internal jugular vein for three weeks. There was a pin-hole communication between the common carotid artery and the pseudoaneurysm, which was successfully obliterated by surgery. Carotid pseudoaneurysm formation is a rare complication of internal jugular vein cannulation, and there has been no report of its formation after apparently successful jugular vein cannulation. This complication is difficult to predict, and careful observation after removal of the catheter is mandatory.

Aged↗

PubMedDate not supplied

Surgical treatment for Takayasu's arteritis. A long-term follow-up study.

Thirty patients with Takayasu's arteritis treated surgically were followed for more than ten years postoperatively, 28 women and 2 men. The average age at the initial operation was 29 years. The clinicopathological finding was classified in four types; the distribution of cases was 6 in Type I, 17 in Type II, 4 in Type III, and 3 in Type IV. Surgical procedures performed were carotid artery reconstruction in 9 patients, thoraco-abdominal aortic bypass in 5, renal artery reconstruction in 10, combined procedures in 2, aneurysmectomy in 2, and other procedures in 2 patients. Twenty-six patients survived; four died during the study period. Twenty-three patients (77%) are well with good function of the reconstructed arteries. Six women had safe deliveries after successful operations. However, anastomotic false aneurysms occurred in 5 patients. The surgical management of Takayasu's arteritis must be distinguished from that of atherosclerotic vascular disease.

Adult↗

PubMedDate not supplied

Surgical treatment of non-specific inflammatory arterial aneurysms.

In the past thirty years, fifty arterial aneurysms due to non-specific inflammation in forty-two patients were operated on. Twenty-five patients were males and 17 were females; their average age was 38 years. The majority of the aneurysms were located in the abdominal aorta, common carotid artery, and femoral artery. Clinical diagnoses were Takayasu's disease (11), Behçet's disease (3), giant cell aortitis (2), and systemic lupus erythematosus (1). The other twenty-five cases were of undetermined etiology. There were fourteen cases of rupture, and long-term steroid administration in five cases was suspected of playing a major role in inducing this grave sequel. Aneurysmectomy with arterial reconstruction was performed on 37 cases. Various histological findings of inflammation were observed in the resected specimens. The suture aneurysms occurred in eight cases in the late period. Surgical care of non-specific inflammatory arterial aneurysms was judged to be more difficult than that of atherosclerotic aneurysms.

Adolescent↗

PubMedDate not supplied

Disseminated intravascular coagulation caused by abdominal aortic aneurysm.

A 71-year-old male with disseminated intravascular coagulation (DIC) caused by abdominal aortic aneurysm was successfully treated surgically. He had aortic regurgitation, an old myocardial infarction, and nephrotic syndrome. The infrarenal part of the inferior vena cava, which was on the left side of the aneurysm, was temporarily transected during the surgical procedure. Preoperative heparin therapy was insufficient, but infusion of blood components during the operation and minimal dissection of the aneurysm were effective in controlling intraoperative hemorrhage. Hypofibrinogenemia and thrombocytopenia were normalized immediately after operation, and hemorrhagic diathesis was completely cured. In this case, the definitive treatment of DIC caused by an abdominal aortic aneurysm war removal of the lesion and the infusion of coagulation factors during the operation was effective in minimizing blood loss.

Aged↗

PubMedDate not supplied

Perianastomotic findings in canine endothelial cell seeded grafts at 3 months.

Endothelial cell seeding is one of the methods commonly used to prepare an antithrombogenic surface for small caliber vascular prostheses. In this study, we investigated the perianastomotic tissue reaction of seeded grafts, using a canine model. Eight dogs were used to harvest endothelial cells (ECs) enzymatically from their external jugular veins, with one dog being excluded because of infection. ECs were cultured and seeded, using a rotation method, onto a small caliber prosthesis woven with ultrafine polyester fibers. Each graft was implanted into the carotid artery of its cell donor dog, with another implanted contralaterally as a non seeded control. Two of seven seeded grafts were patent at 3 months, while all controls were occluded. Histologic examination revealed a continuous lining of ECs in the patent grafts, but thickening of the intima at the anastomoses was also observed. The occluded seeded grafts had organized hard thrombi and thick fibrosis at the perianastomotic area, however, with few thrombi in the midportion. These observations suggest that the investigation of a small caliber prosthesis with the ultimate aim of producing better patency should focus not only on antithrombogenicity of the surface of the lumen, but also on the perianastomotic biologic reaction.

Animals↗