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Biomedical subjects

K Takagi

Publications and source records attributed to K Takagi.

At least 541 records · Page 30Linked to original sources
PubMed1990

Ultrastructural differentiation in the distal ends of ameloblasts from the presecretory zone to the early secretory zone.

Morphological differentiation of the distal ends of ameloblasts (AMs) from the late presecretory to early secretory zones of the rat upper incisor was studied by electron microscopy. Preameloblasts (PAs) showed a high columnar shape, with the nucleus located in the basal portion. The Golgi apparatus occupied the supranuclear region with type-1 vesicles, and microvilli were present at the distal cell membrane. Coarse-textured material was observed inside the type-1 vesicles and in the lateral intercellular spaces as well as along the distal cell membrane, whereas fine-textured material was found along the distal cell membrane. Near the region of initial enamel formation, large matrix islands were found in the lateral intercellular space. A thin electron-dense layer was observed on the dentin surface. This layer might have occurred as a result of diffusion after degradation of the coarse- or fine-textured material into a finer substance in the extracellular spaces. In the region of initial enamel formation, the distal cell membrane of AMs was flat, but shallow and narrow membrane invaginations were associated with the cell membrane close to the matrix islands. In the region of inner enamel formation, a cone-shaped Tomes' process was formed between large matrix islands which had developed in the intercellular spaces between the lateral portions of the distal ends of AMs. It was considered that the membrane invaginations which had existed at the distal end of PAs moved lower toward the distal terminal bar, thereafter becoming microvilli.

Ameloblasts↗
PubMed1990

Degeneration and ossification of the yellow ligament in unstable spine.

Lumbar yellow ligaments were obtained from 20 cases of lumbar spinal canal stenosis and 20 cases of degenerative olisthesis with slippage of more than 3 mm. The ligaments were stained with safranin-O, von Kossa, and immunohistochemical staining methods (S-100 protein). In the unstable group the safranin-O staining was more intense, microscopic ossification and chondroblasts were noted more frequently, and S-100 protein was more abundant. These findings show that instability of the lumbar spine accelerates degeneration and chondrometaplasia of the yellow ligament, which may lead to the enchondral ossification of the ligament.

Adult↗
PubMed1990

Priming effect of recombinant human interleukin-2 and recombinant human interferon-gamma on human neutrophil superoxide production.

The effect of recombinant human interleukin-2 (rhIL-2) and recombinant human interferon-gamma (rhIFN-gamma) were evaluated on superoxide (O2-) production of human polymorphonuclear neutrophils (PMNs). Ten minutes incubation with rhIL-2 showed a dose-dependent enhancement of n-formyl-methionyl-leucyl-phenylalanine (FMLP)-induced O2-production of human PMNs, and the rate of enhancement reached 49.6% at the concentration of 3000 U/ml rhIL-2. Same pretreatment with rhIFN-gamma also showed a dose-dependent enhancement of FMLP-induced O2-production of human PMNs, and the maximal rate of enhancement was 47.0% at the concentration of 3000 U/ml rhIFN-gamma. Any cytokines given alone did not induce O2- production. These cytokines showed no enhancement of phorbol myristate acetate (PMA)-induced O2- production, neither. The effects of these cytokines to FMLP-induced O2- production were kept in calcium-free medium. Moreover, incubation with these cytokines caused no elevation of intracellular free calcium concentration [( Ca++]i) in resting PMNs. Incubation with them did not change the increase of [( Ca++]i) of PMNs induced by FMLP significantly, neither. Recombinant forms of cytokines are used clinically, now. These results may be helpful for the use of them.

Adult↗
PubMed1990

Mechanism of atrial natriuretic polypeptide and sodium nitroprusside-induced relaxation in guinea-pig tracheal smooth muscle.

Atrial natriuretic polypeptide (ANP) is composed of a family of peptides isolated from rat and human atria. In the present study, the relaxant effects of ANP, sodium nitroprusside and 8-bromo-cyclic guanosine monophosphate (GMP) were investigated in guinea-pig tracheal smooth muscle, and the tissue cyclic GMP and cyclic adenosine monophosphate (AMP) concentrations were measured. ANP, sodium nitroprusside and 8-bromo-cyclic GMP showed relaxant effects on the spontaneous tone in normal Krebs solution (5.9 mmol/l K(+)-2.4 mmol/l Ca++ solution). They diminished relaxant effects on 40 mmol/l K(+)-0.1 mmol/l Ca++ induced contraction, which was approximately the same tension as the spontaneous tone. Sodium nitroprusside and 8-bromo-cyclic GMP diminished less relaxant effects on 40 mmol/l K(+)-2.4 mmol/l Ca++ induced contraction, but ANP showed no relaxation. The tissue cyclic GMP levels following administration of ANP and sodium nitroprusside in normal Krebs solution, in 40 mmol/l K(+)-2.4 mmol/l Ca++ solution, and in 40 mmol/l K(+)-0.1 mmol/l Ca++ solution increased dose-dependently without regard to external Ca++ concentrations, while the tissue cyclic AMP levels did not change. These results suggest that ANP might be a novel potent relaxant in airway smooth muscle and the relaxant effect may be, at least in part, mediated by cyclic GMP. There was a difference in relaxant effects on tracheal smooth muscle between ANP and sodium nitroprusside.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1990

[Tuberculosis sequelae: secondary fungal infections].

The antibody activities against Aspergillus fumigatus, Cryptococcus neoformans and Coccidioides immmitis by complement fixation (CF) were examined for active and cured pulmonary tuberculosis in 1985, and against Aspergillus fumigatus and Candida albicans by indirect hemagglutination (IHA) and counterimmunoelectrophoresis (CIE) in 1986. The antibody activity against Aspergillus by CF was positive in 8.6% of the sera and negative against Cryptococcus, and Coccidioides. The IHA results were positive in 2.9% against Aspergillus and in 44.9% against Candida. The CIE results were positive in 19.5% against Aspergillus and in 16.3% against Candida. Based on chest X-ray films, the development of pulmonary candidiasis was non-specific but that of pulmonary aspergilloma in tuberculous cavities was specific. Before aspergillomas were formed, the tuberculous cavities had become thin-walled. Then the cavities increased or decreased in size. It is postulated that the cavity has tension when check-valved by mycetome in the drainage bronchus, and becomes smaller or distinct when ventilated inadequately. In cases cavities do not change in size due to intracavitary proliferation of Aspergillus, the wall of cavity is rough, prominent, or opaque.

Adult↗
PubMed1990

[Neurofibroma originated from the intrathoracic vagal nerve in a patient with von Recklinghausen's disease--a case report].

A neurofibroma originated from the intrathoracic vagal nerve was presented. A 26-year-old male was found to have an abnormal shadow in the right chest filed on a routine examination. He was complicated with Von Recklinghausen's disease and showed multiple "cafe au lait" spots over his extremities and trunk but no subcutaneous mass. A block resection of the mass was carried for the mediastinal tumor. The tumor was arising from the right intrathoracic vagal nerve which located just below the origin of recurrent nerve and was measured 3 X 3 X 6 cm. Histological examination of the specimen revealed neurofibroma. His postoperative course was uneventful. A brief review in Japan was made on 22 cases collected from the literature.

Adult↗
PubMed1990

Effect of the new anti-allergic compound ethyl 2-(4'-carboxybenzamido)-4-propionamidobenzoate sodium salt on human neutrophil superoxide production.

The effect of the new orally active antiallergic compound ethyl 2-(4'-carboxybenzamido)-4-propionamidobenzoate sodium salt (AM-682) and its main metabolite (met-A) were evaluated on respiratory burst in isolated human polymorphonuclear neutrophils (PMN). Both compounds exhibited inhibitory effect with concentration dependency on the n-formyl-methionyl-leucyl-phenylalanine (FMLP)-induced superoxide (O-2) production by human PMN. The inhibitory activity of met-A (IC50 1.1 mumol/l) was higher than that of AM-682 (IC50 85 mumol/l). By contrast, these compounds affected neither PMN O-2 production induced by phorbol 12-myristate 13-acetate (PMA) nor extracellular O-2 generation by the reaction of xanthine oxidase with hypoxanthine. These results indicate that the effects of these compounds act specifically on the generation of O-2 and is not simply a scavenger of O-2. This anti-inflammatory effect may also be beneficial in the treatment of asthma.

Adult↗
PubMed1990

Chemically induced transplantable malignant fibrous histiocytoma of the rat. Analyses with immunohistochemistry, immunoelectron microscopy and [3H]thymidine autoradiography.

Malignant fibrous histiocytoma was produced in rats by injection of 9,10-dimethyl-1,2-benzanthracene into their knee joints. The original tumors consisted mainly of fibroblast-like cells and histiocyte-like cells, often intermixed with bizarre giant cells, and they frequently showed the storiform-pleomorphic pattern. By immunohistochemistry, anti-rat macrophage monoclonal antibodies, TRPM-3, RM-1, and Ki-M2R, and anti-rat leukocyte common antigen reacted to the histiocyte-like cells but not to the fibroblast-like cells. By the single cell cloning method, we established six tumor cell lines, none of which reacted with the anti-rat macrophage monoclonal antibodies, possessed any Fc receptors, or conducted immune phagocytosis and Latex particle phagocytosis. The ultrastructure of the cloned tumor cells resembled that of long-term cultured dermal fibroblasts. Collagen production by the tumor cells was demonstrated immunohistochemically with a monoclonal antibody for type I collagen. Inoculation of the cloned tumor cells into rats produced tumors with the histology of malignant fibrous histiocytoma and induced prominent macrophage infiltration. In the rat tumors produced by the inoculation of [3H]thymidine labeled cells, no reactivity of tumor cells with the anti-rat macrophage monoclonal antibodies was observed. Transplantation of the cultured rat tumor cells into nude mice produced tumors similar in histology to the original rat malignant fibrous histiocytoma. Tumor cells in nude mice induced marked macrophage infiltration as detected by immunohistochemistry with the anti-mouse macrophage monoclonal antibody F4/80. No differentiation of tumor cells into macrophages was detected, since no cells were stained with biotinylated anti-rat macrophage monoclonal antibody TRPM-3. By the flash labeling method with [3H]thymidine, infiltrating macrophages in the nude mouse tumors were proved to derive from the bone marrow of the host animals. These results indicate a possible experimental reproduction of malignant fibrous histiocytoma by proliferation of malignant fibroblasts or their related cells in combination with macrophage infiltration.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1990

[Clinical studies on cefteram pivoxil in the treatment of respiratory infections].

Cefteram pivoxil (CFTM-PI), a new ester type cephem antibiotic, was administered at a daily dose of 600 mg to 81 patients with respiratory infections. They included 4 cases of laryngopharyngitis, 5 cases of tonsillitis, 26 cases of acute bronchitis, 13 cases of pneumonia, 10 cases of chronic bronchitis, 1 case of diffuse panbronchiolitis, 14 cases of infected bronchiectasis and 8 cases of infected other chronic respiratory diseases. Clinical effects were excellent in 18 cases, good in 50 cases, fair in 7 cases, and poor in 6 cases, thus, the efficacy rate was 84.0%. Nausea was observed in 2 cases, and diarrhea, vertigo, or fever was observed in 1 case each. The elevation of GOT and GPT values were found in 4 cases and a slight elevation of total bilirubin value was found in 1 case. These adverse reactions, however, were slight in their grades. CFTM-PI appears to be a useful oral cephem antibiotic in the treatment of respiratory infections.

Administration, Oral↗
PubMed1990

[Meningoencephalitis in Kawasaki disease].

Kawasaki disease (KD) is a syndrome characterized by various degrees of vasculitis in small-and medium-sized arteries. We discussed the characteristic manifestations and prognosis of 5 KD patients (male 3, female 2) with meningoencephalitis in the acute stage. The incidence was 3.7% (5 of 138 patients) in our institute. The age of onset was between 3 months and 15 months. The clinical manifestations included disturbance of consciousness and seizures; disturbance of consciousness developed in all patients in the early acute stage. The duration was between 2 and 11 days; seizures developed as status convulsions in two. Electroencephalograms (EEG) demonstrated certain abnormalities in 2 of 4 patients studied. Computed-tomographic scanning (CT scan) revealed fluid collection in the frontal extracerebral space, and monocyte-predominant pleocytosis was observed in the cerebrospinal fluid (CSF) in all 5 patients studied. The age of onset in the 5 KD patients was significantly earlier than that in non-complicated cases (n = 138, P less than 0.01). Blood hemoglobin (P less than 0.05) and hematocrit (P less than 0.05), serum total protein (P less than 0.01), and serum albumin levels (P less than 0.01) were also significantly lower. Moreover the period until CRP values turned negative was significantly longer (P less than 0.05) and erythrocyte sedimentation rate was significantly lower (P less than 0.01) in these 5 patients. It was considered that meningoencephalitis in KD may develop in cases having more severe and prolonged inflammatory changes; the clinical findings revealed a serious form of KD. We suggest that this might because by vasculitis of small arteries, arterioles, capillaries, and venules, which consists of infiltration of lymphocytes and large mononuclear cells, and edema. There was no neurological sequela in 4 of the 5 patients. However, one patient was found to have hearing difficulty 3 years after the onset. Therefore, the prognosis of meningoencephalitis in KD was considered to be generally favorable.

Brain↗
PubMed1990

A limited role of IL-1 in immune-enhancement by adjuvants.

Generation of interleukin-1 (IL-1) in the draining lymph nodes after injection of complete Freund's adjuvant (CFA), incomplete Freund's adjuvant (IFA) and alum was studied in line with IL-1 mRNA expression (cytoplasmic slot blot analysis) and IL-1 beta antigen detection (ELISA and immunohistochemistry) in rabbits. The expression of IL-1 beta mRNA was marked from 6 to 96 hr, with a maximum at around 24 hr post-injection of CFA, while injection of the other two adjuvants elicited only a moderate or negligible response. On the other hand, IL-1 alpha mRNA expression was almost negligible during the entire 8-week observation period after injection of the above three adjuvants. Generation of IL-1 beta antigen in the draining lymph nodes after CFA injection paralleled the expression of IL-1 beta mRNA. Immunohistochemistry revealed that cells containing IL-1 beta resided in the medullary sinuses, marginal sinuses and para-cortical area, but not in the follicles. Despite marked generation of IL-1 beta in CFA-treated draining lymph nodes, the primary antibody response (IgG) to ovalbumin differed only slightly between the three animal groups that were immunized with the antigen incorporated in CFA, IFA and alum. Further, rIL-1 beta did not significantly enhance the immune response when it was entrapped together with the antigen in IFA and alum. IL-1 beta enhanced the immune response only when it was injected with antigen without adjuvant. Thus, IL-1 seemed to play only a limited role, if any, in the augmentation of the primary immune response by the above-mentioned adjuvants.

Adjuvants, Immunologic↗
PubMed1990

[A clinical study on ceftazidime in the treatment of intractable respiratory infections].

Ceftazidime (CAZ) was administered to 51 patients (37 males, 14 females) with respiratory infections including severe cases, accompanied by various underlying respiratory diseases. The clinical efficacy and side effects of CAZ were investigated. The mean age and body weight of these 51 cases were 62.6 years and 48.0 kg, respectively. CAZ was administered by intravenous drip infusion (daily dose of 2-4 g) for a mean of 14.7 days to a mean total dose of 56.7 g. Clinical efficacy rates were 64% (18 of 28 cases), 80% (16 of 20 cases) and 67% (2 of 3 cases) for airway and intermediary regional infections, pneumonia (including lung abscess) and pyothorax, respectively. In the bacteriological study, efficacy rates and bacterial eradication rates were 69% and 67%, 33% and 20%, 100% and 100%, and 100% and 100% for infections caused by Pseudomonas aeruginosa (13 cases), Staphylococcus aureus (6 cases), Streptococcus pneumoniae (6 cases) and Klebsiella pneumoniae (4 cases), respectively, and bacterial eradication was achieved in both of 2 cases of Peptostreptococcus anaerobius and 2 cases of Haemophilus influenzae, and 1 case each of Peptococcus sp., Fusobacterium necrophorum and Serratia marcescens. Side effects observed were eruption in 1 case (2%) and elevated GOT, GPT and Al-P values in 1 case (2%), but these cases tended to recover after CAZ treatment was discontinued.

Adult↗
PubMed1990

[Brachial plexus injury and fracture of the first rib as complications of median sternotomy].

In 192 patients following median sternotomy during from 1978 to 1988, we studied the incidence, cause, prognosis and correlation of brachial plexus injury and fracture of the first rib as complications of median sternotomy. Four brachial plexus injuries were identified, an incidence of 2.1%, seven first-rib fractures were identified, an incidence of 3.6% and one patient had both complications in this series. Symptoms of this patient were more severe and difficult to improve than those of patients without first-rib fracture. Stretching of the nerve by the displaced first rib, ischemia of the nerve by pressure on it, and direct injury by the fractured rib end are causes of the brachial plexus injury following median sternotomy. It is due to the difference of position of the fracture, the difference of direction and degree of the protrusion of the fractured rib end, whether presence or absence of the brachial plexus injury in patients with first-rib fracture.

Adolescent↗
PubMed1990

Hemodynamic changes in splenic blood flow during and after distal splenorenal shunt.

The purpose of this study was to examine the hemodynamic changes of the spleen and the subsequent influence on the numbers of blood cells both during and 1 month after distal splenorenal shunt (DSRS) with splenopancreatic disconnection in 20 patients with portal hypertension. The intraoperative splenic blood flow, measured with an electromagnetic flowmeter, significantly increased after shunt insertion: the mean percentage increases within the splenic vein and artery were 60% (p less than 0.01) and 37% (p less than 0.05), respectively. The splenic venous blood flow, measured with a pulsed Doppler flowmeter, had not changed significantly 1 month postoperatively (676 +/- 501 to 540 +/- 306 ml/min). The WBC and platelet counts significantly (p less than 0.05 and p less than 0.01, respectively) increased 1 month postoperatively, whereas there was a small, but significant (p less than 0.05), decrease in RBC count. We concluded that splenic blood flow increases immediately after DSRS with splenopancreatic disconnection, but this increase may be only short term. The influence of the postoperative hemodynamic changes on blood cell count is uncertain.

Adult↗
PubMed1990

[Indication and limitation of inhalation therapy].

In recent years, the clinical application of aerosol inhalation therapy has increased rapidly, however, many problems are not yet fully dissolved. In this symposium, most adequate condition and procedure for the inhalation therapy in terms of lesional localization and the recognition of therapeutic limitation were mainly discussed.

Administration, Inhalation↗
PubMed1990

[Inhalation therapy for bronchial asthma. A. Bronchodilator--beta 2-stimulant].

In the treatment of bronchial asthma, usefulness of beta 2-agonists aerosol inhalation are emphasized as well as sustained theophylline tablets recently. In this study, the effectiveness of procaterol metered dose inhalor on asthmatic patients were examined compared with procaterol tables. The effect of procaterol inhalor together with sustained-theophylline on Holter ECG were also examined. When procaterol was exchanged to inhalation from tablets, 41% of the patients were improved symptomatically. Procaterol inhalor had no effect on Holter ECG. Procaterol inhalation regularly was expected to be more useful in treating asthmatic patients than tablets.

Administration, Inhalation↗