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Biomedical subjects

K Maeda

Publications and source records attributed to K Maeda.

At least 307 records · Page 17Linked to original sources
PubMed1999

Lysis of myelocytes in chickens infected with infectious bursal disease virus.

In specific-pathogen-free chickens infected with the highly virulent HPS-2 strain or virulent reference GBF-1 strain of infectious bursal disease virus (IBDV), pathologic changes of the bone marrow were investigated. On histologic examination, bone marrow lesions were prominent in the HPS-2 group but only mild in the GBF-1 group. The bone marrow of the HPS-2 group showed severe lysis and depletion of heterophil myelocytes with pyknotic nuclear alteration 2-3 days after inoculation. On examination with an electron microscope, heterophil myelocytes were characterized by shrinkage of the cytoplasm and peripheral condensation of nuclear chromatin. IBDV particles were not detected in altered myelocytes. A terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling method demonstrated a positive reaction in only heterophil myelocytes. In contrast, nucleosomal DNA fragmentation in HPS-2-infected bone marrow cells was indiscernible by agarose gel electrophoresis. These findings indicate that lysis of bone marrow cells is selectively induced in heterophil myelocytes at an early stage after IBDV infection and independent of virus replication.

Animals↗
PubMed1999

Regulation of rat mesangial cell migration by platelet-derived growth factor, angiotensin II, and adrenomedullin.

This study sought to determine whether platelet-derived growth factor (PDGF) and angiotensin II (AngII) stimulate migration of cultured rat glomerular mesangial cells. After finding that this was so, the effects of adrenomedullin (ADM) and cAMP-elevating agents on basal and stimulated mesangial cell migration were examined. Two isoforms of PDGF, AB and BB, stimulated migration in a concentration-dependent manner between 1 and 50 ng/ml, while the AA isoform lacked significant effect. AngII modestly but significantly stimulated migration in a concentration-dependent manner between 10(-7) and 10(-6) mol/L. Rat ADM significantly inhibited the PDGF BB- and AngII-stimulated migration in a concentration-dependent manner between 10(-8) and 10(-7) mol/L. Inhibition by rat ADM was accompanied by an increase in cellular cAMP. cAMP agonists or inducers such as 8-bromo cAMP, forskolin, and prostaglandin I2 also significantly reduced the stimulated migration. H 89, a protein kinase A (PKA) inhibitor, attenuated the inhibitory effect of ADM, and a calcitonin gene-related peptide (CGRP) receptor antagonist, human CGRP (8-37), abolished the inhibitory effects of rat ADM. These results suggest that PDGF AB and BB as well as AngII stimulate rat mesangial cell migration and that ADM can inhibit PDGF BB- and AngII-stimulated migration, at least in part through cAMP-dependent mechanisms likely to involve specific ADM receptors with which CGRP interacts. The adenylate cyclase/cAMP/PKA system may be involved in the migration-inhibitory effect of ADM in these cells.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1999

Role of adipocytokines on the pathogenesis of atherosclerosis in visceral obesity.

Obesity which is defined as accumulation of excess body fat, is a major cause of atherosclerotic vascular disease in industrial countries. Recent advances in the biology of adipose tissue have revealed that adipose tissue is not simply an energy storage organ but it also secretes a variety of molecules which affect the metabolism of the whole body. Through a systematic search of active genes in adipose tissue, we found that adipose tissue, especially visceral fat expressed numerous genes for secretory proteins (about 30% of total genes analyzed). Among them, plasminogen activator-1 (PAI-1), which is a regulator of the fibrinolytic system, was overexpressed in the visceral fat in an animal model of obesity. Plasma levels of PAI-1 were closely correlated with visceral fat adiposity. Thus, PAI-1 secreted from visceral fat may play some role in thrombotic vascular disease in visceral obesity. Adiponectin, a novel adipose-specific gene product, which has a matrix-like structure, is abundantly present in the bloodstream. Dysregulated secretion of adiponectin may be related to vascular disease in obesity. Biologically active molecules secreted from adipose tissue (adipocytokines) may have important roles in the development of atherosclerotic disease in obesity.

Adiponectin↗
PubMed1999

Matrix metalloproteinase-1 expression is a prognostic factor for patients with advanced gastric cancer.

Proteolytic activity of cancer cells is an important factor in metastasis. This study examined the relationship between MMP-1 expression of gastric cancer cells and peritoneal metastasis. MMP-1 expression was found in 76/103 (75.2%) cases examined and was significantly associated with both peritoneal metastasis and lymph node metastasis (p<0.05, respectively). The prognosis of patients with MMP-1 positive tumor was significantly worse than that of patients with MMP-1 negative tumor (p<0.05). These findings suggested that MMP-1 might be a prognostic factor in case of advanced gastric cancer and might be useful in determining whether or not adjuvant therapy was indicated for patients at high risk of peritoneal recurrence.

Adult↗
PubMed1999

Endoneurial microvasculature of chronically transected sciatic nerves in diabetic rats.

To characterize the morphology of the endoneurial microvasculature of degenerating nerves under hyperglycemia, the morphology of endoneurial microvessels in transected sciatic nerves was examined in normal and streptozotocin-induced diabetic rats. Three months after transection, the fascicular area and median vascular luminal area at the proximal level of the distal stump were significantly larger in diabetic than in control animals, whereas the number of vessels per fascicle was the same in the two groups. Arterioles in various stages of development were found in the centrifascicular region in some transected nerves. Serial sections revealed that these vessels originated from transperineural arterioles. The frequency and magnitude of vascular wall thickening were both greater in diabetic rats. These results suggest that the endoneurial microvasculature responds abnormally to nerve injury under hyperglycemia.

Animals↗
PubMed1999

[Diabetic neuropathy: clinical and experimental progress in its pathogenesis and treatment].

Diabetic symmetrical polyneuropathy have been known to arise from metabolic alteration such as accelerated polyol pathway and/or from neurovascular deficit. Recently, two other hypotheses were confirmed. Decreased neurotrophic supports were reported in diabetic neuropathy. Subcutaneous injection of recombinant human nerve growth factor ameliorated sensory symptoms and cooling detection threshold. The most common adverse effect was injection site hyperalagesia. Brain-derived neurotrophic factor, neurotrophin-3 and insulin-like growth factors are under clinical trials. The excessive oxidative stresses are also associated with diabetic neuropathy. Increased production and decreased scavenge system of free radicals enhance their cytotoxic effects. Alpha-lipoic acid, gliclazide and troglitazone have been reported to be effective for diabetic neuropathy.

Animals↗
PubMed1999

[Vitrectomy for proliferative diabetic retinopathy associated with iris rubeosis].

OBJECT: To compare the results of vitrectomy for phakic cases and those of aphakic cases with proliferative diabetic retinopathy (PDR) accompanied by rubeosis iridis. MATERIALS & METHODS: We reviewed 34 eyes of 24 cases that underwent vitrectomy for proliferative diabetic retinopathy with rubeosis iridis. RESULT: Phakic eyes needed significantly more reoperations (p < 0.001) than aphakic eyes. Aphakic eyes had significantly more successful visual results (p < 0.05) and better control of intraocular pressure (p < 0.005) than phakic eyes. CONCLUSION: This study showed the possibility that phakic eyes had more ischemic retina producing more angiogenic factors than aphakic eyes which had the same grade of rubeosis iridis. Phakic eyes with pre-operative rubeosis iridis need thorough clearance of ocular ischemia by panretinal photocoagulation.

Diabetic Retinopathy↗
PubMed1999

[A case of prostate cancer associated with osteolytic bone metastases].

It is well known that prostate cancer metastasizes bone with osteoblastic change and that osteolytic change is rare. We report a case of prostate cancer that had bone metastases which were all osteolytic. A 62-year-old man was referred to our department because of abnormal prostatic acid phosphatase and pain in his right upper arm. Digital examination revealed an enlarged and hard prostate. A computed tomographic scan revealed multiple osteolytic changes and a bone scintigraphy was positive at these sites. Histopathology of both prostate and humerus showed poorly differentiated adenocarcinoma. He received castration and antiandrogen as hormonal therapy, but the patient's prostate specific antigen did not normalize. Therefore this case was suspected to be hormone-refractory prostate cancer.

Adenocarcinoma↗
PubMed1999

Concealed hypothyroidism in patients with myeloperoxidase antineutrophili cytoplasmic autoantibodies- (MPO-ANCA) positive renal disease.

AIM: To elucidate the relationship between thyroid disorders and myeloperoxidase (MPO) antineutrophili cytoplasmic autoantibodies-(ANCA) positive renal disease, we investigated the prevalence of thyroid diseases in patients with them. SUBJECTS AND METHODS: The subjects consisted of 10 patients (6 males and 4 females) diagnosed as having MPO-ANCA-positive renal disease in our hospital. To evaluate thyroid function, serum thyroid-stimulating hormone (TSH) and free-thyroxine (FT4) levels were measured by a immunoradiometric assay (IRMA) and a radioimmunoassay (RIA), respectively. Thyroid autoantibodies against microsomal antigen and thyroglobulin were measured by means of particle agglutination. In addition, antibodies against thyroid peroxidase (TPO-Ab) and purified thyroglobulin (Tg-Ab) were also determined by RIA. To assess the disease activity, we employed Birmingham Vasculitis Activity Score (BVAS). RESULTS: The results were that 4 out of 10 patients (40%) were accompanied by hypothyroidism, including 2 patients with subclinical hypothyroidism and I during thyroid hormone replacement therapy. The BVAS of the hypothyroidism group (group A) was significantly lower (p < 0.05) than that of non-hypothyroidism group (group B), 18.5 +/- 9.0 (mean +/- SD) versus 24.2 +/- 16.6. MPO-ANCA titers were not significant between the two groups, 376.8 +/- 316.8 EU versus 311.5 +/- 203.6 EU. CONCLUSION: Thyroid disorder, especially hypothyroidism would not be a rare complication in patients with MPO-ANCA-positive renal disease. We should concentrate more on thyroid lesion in them.

Aged↗
PubMed1999

[A case of common variable immunodeficiency that responded to long-term erythromycin chemotherapy].

A 32-year-old woman with common variable immunodeficiency (CVID) accompanied by sinopulmonary infection was evaluated for purulent sputum, cough, and nasal obstruction that did not respond to regular intravenous immunoglobin (IVIG) infusion. Chest X-ray films revealed bronchiectasis affecting both lung bases, and a bacteriological examination of sputum was positive for Pseudomonas aeruginosa. Long-term chemotherapy with erythromycin (EM) was started, and the patient's respiratory symptoms gradually subsided. Sinopulmonary infection is the dominant clinical complication in patients with CVID. This case suggested that long-term EM chemotherapy is useful for the treatment of IVIG-refractory sinopulmonary infection associated with CVID.

Adult↗
PubMed1999

[Weekly hepatic arterial infusion of high dose 5-fluorouracil for liver metastasis from colorectal cancer].

A weekly infusion of high dose 5-fluorouracil by way of the hepatic artery has been performed in 23 cases with synchronous metastasis from colorectal cancer since 1993. The prognosis in these cases was compared with 94 cases treated without infusion chemotherapy in 94 cases before 1992. The overall one-year and three-year survival rate was 64.8% and 30.2%, respectively, in cases with infusion chemotherapy. The one-year and three-year survival rate was 42.8% and 18.6%, respectively, in cases without infusion chemotherapy. Overall survival rate was significantly different between cases with and without infusion chemotherapy (p < 0.05). In conclusion, weekly infusion chemotherapy resulted in a better survival rate than without infusion chemotherapy.

Antimetabolites, Antineoplastic↗
PubMed1999

Analysis of fetal movements by Doppler actocardiogram and fetal B-mode imaging.

We have presented that fetal surveillance may be enhanced by use of the fetal actocardiogram and by computerized processing of fetal motion as well as fetal B-mode ultrasound imaging. Ultrasonic Doppler fetal actogram is a sensitive and objective method for detecting and recording fetal movements. Computer processing of the actograph output signals enables powerful, detailed, and convenient analysis of fetal physiologic phenomena. The actocardiogram is a useful measurement tool not only in fetal behavioral studies but also in evaluation of fetal well-being. It reduces false-positive, nonreactive NST and false-positive sinusoidal FHR pattern. It is a valuable tool to predict fetal distress. The results of intrapartum fetal monitoring are further improved by the antepartum application of the actocardiogram. Quantified fetal motion analysis is a useful, objective evaluation of the embryo and fetus. This method allows monitoring of changes in fetal movement, as well as frequency, amplitude, and duration. Furthermore, quantification of fetal motion enables evaluation of fetal behavior states and how these states relate to other measurements, such as changes in FHR. Numeric analysis of both fetal actogram and fetal motion from B-mode images is a promising application in the correlation of fetal activity or behavior with other fetal physiologic measurements.

Echocardiography↗
PubMed1999

[Minimally invasive transanal surgery].

A new anal retractor connected to an Octopus retractor holder and automatic suture clamp were used for local excision of rectal tumors to obtain easy access to proximal tumors with an adequate surgical field and to avoid complications. Shortening techniques and invagination techniques were adopted to pull down proximal tumors. This surgical procedure resulted in shorter operating time, less bleeding, earlier oral intake, shorter hospital stay, and fewer complications.

Adult↗