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Biomedical subjects

T Maeda

Publications and source records attributed to T Maeda.

At least 1,081 records · Page 60Linked to original sources
PubMed1987

Distribution of nerve fibers immunoreactive to neurofilament protein in rat molars and periodontium.

The distribution of nerve fibers in molars, periodontal ligament and gingiva of the rat shows a complex pattern. Decalcified material including the alveolar bone was sectioned in three different planes and stained by means of immunohistochemistry for detection of the neurofilament protein (NFP); the immunoreactive neural elements were clearly visualized in three-dimensional analyses. NFP-positive nerve fibers formed a subodontoblastic plexus in the roof area of the dental pulp; some of them entered the predentin and dentin directly through the dentinal tubules. This penetration was found mainly in the pulp horn, and was limited to a distance of about 100 micrometers from the pulpo-dentinal junction. In the periodontal ligament, NFP-positive nerve fibers were found densely distributed in the lower half of the alveolar socket. Two types of nerve terminals were recognized in the periodontal ligament: free nerve endings with tree-like ramifications, and expanded nerve terminals showing button- or glove-like shapes. The former tapered among the periodontal fibers, some even reaching the cementoblastic layer. The latter were located, frequently in groups, within the ligament restricted to the lower third of the alveolar socket. A well-developed plexus of NFP-positive nerves was revealed in the lamina propria of the free gingiva, the innervation being denser toward the epithelium of the gingival crevice. The characteristic distribution of NFP-immunoreactive nerve fibers revealed in this study is discussed in relation to region-specific sensations in the teeth and surrounding tissues.

Animals↗
PubMed1987

The effects of prazosin and propranolol in combination with thiazide diuretics on blood pressure and serum lipids: a multicentre study.

We have carried out randomized 12-week multicentre study to compare the effects of prazosin and propranolol on blood pressure and serum lipids in 70 patients with essential hypertension after a 4 week minimum period of treatment with thiazide diuretics. After 12 weeks treatment with prazosin (n = 40, 1.5-12.0 mg per day) or propranolol (n = 30, 30-120 mg per day) with diuretics there was a significant blood pressure reduction from 165.1/97.9 mmHg to 151.2/90.6 mmHg and from 167/96.5 mmHg to 153/91.9 mmHg, respectively. In the 12th week a significant decrease was noted in triglyceride and in low-density lipoprotein cholesterol (LDL + VLDL-C), but no significant effects were seen in high-density lipoprotein cholesterol (HDL-C) in patients receiving prazosin. On the other hand, a significant decrease in lecithin cholesterol acyltransferase (LCAT) was seen in patients receiving propranolol. Twenty-six of 40 patients receiving prazosin were given an additional 12 weeks of treatment. Twenty-two of 30 patients initially treated with propranolol were switched from propranolol to prazosin after 13 weeks and given prazosin up to the 24th week. At 24 weeks, the blood pressure was 149/93.0 mmHg in the prazosin group and 155/89.2 mmHg in the group which switched from propranolol to prazosin. Triglyceride remained reduced in the prazosin group at the 24th week. In the group which switched from propranolol to prazosin, triglyceride decreased significantly over the next 12 weeks.

Benzothiadiazines↗
PubMed1987

Differentiation of an Abelson virus-transformed immature B precursor cell line under the expression of tyrosine kinase activity of v-abl oncogene product.

The expression of v-abl oncogene during the in vitro differentiation of an Abelson-virus-transformed immature B precursor cell line from immunoglobulin-null to intracytoplasmic mu-positive cells and further to intracytoplasmic gamma 2b-positive cells was examined. The results showed no significant alteration in the amounts and tyrosine kinase activity of v-abl oncogene product during differentiation, indicating that B cell differentiation processes are independent of v-abl functions.

Abelson murine leukemia virus↗
PubMed1987

Distribution of two types of monoamine oxidase-containing neurons in the cat medulla oblongata demonstrated by an improved histochemical method.

The topographic distribution of cells containing monoamine oxidase, the enzyme which deaminates amines, was studied in the cat medulla oblongata. By means of enzyme histochemistry using a new coupled peroxidation method, monoamine oxidase activity was demonstrated in the somata, dendrites and fibers. Type A monoamine oxidase, inhibited by clorgyline but not deprenyl, were localized in the cells distributed in the ventrolateral and dorsomedial medulla where catecholaminergic neurons are present. Type B monoamine oxidase-positive cell bodies were identified in the regions containing serotonergic neurons. Furthermore, we found an intense activity of type A monoamine oxidase in many cells of the dorsal motor nucleus of the vagus of the rostrocaudal extent, and more rostrally in the nucleus parvocellularis where few or no aminergic neurons have been described.

Animals↗
PubMed1987

Localization of D-amino acid oxidase in Bergmann glial cells and astrocytes of rat cerebellum.

The localization of D-amino acid oxidase in rat cerebellum was systematically studied in serial fixed sections at the levels of both light and electron microscopy using a coupled peroxidation method based on the intensifying effect of nickel ions. Deposits were only seen in astrocytes and Bergmann glial cells, and not in neuronal components, endothelial cells or ependymal cells. In the molecular layer, heavy deposits were present in the profiles of Bergmann glial processes around the complexes of synapses where the parallel fiber varicosities form synapses with the thorns emerging from the spiny branchlets of Purkinje cell dendrites. In the Purkinje cell layer, the oxidase-containing processes of Bergmann glial cells enveloped basket cell axons, their terminals, the terminals of the recurrent collaterals of Purkinje cell axons and Purkinje cell bodies. In the granular layer, the cerebellar glomeruli were enveloped by the heavily stained processes of astrocytes. Based on this characteristic localization of the oxidase, we discussed the physiological role of the oxidase in connection with the function of glial cells.

Animals↗
PubMed1987

Formulas for fetal weight estimation by ultrasound measurements based on neonatal specific gravities and volumes.

To improve the accuracy of fetal weight estimation by ultrasound measurement, especially in low birth weight infants, including those with intrauterine growth retardation, two new formulas were developed from a new point of view. The formulas were established by (1) actual measurements of the volumes of the neonatal head and trunk with limbs, (2) analysis of the relationship between the sizes of the parts of the fetal body measured by ultrasound examination before birth and the volumes of the parts of the neonatal body, and (3) calculation of the specific gravities of the parts of the neonatal body. The prospective study showed a high correlation between estimated weights and actual birth weights with a small range of error in infants weighing between 450 and 4800 gm.

Birth Weight↗
PubMed1987

Leydig cells within the aspermatogenic seminiferous tubules.

Cells identical to Leydig cells were found within a peritubular boundary layer and even inside a basal lamina of seminiferous tubules in three male patients (two with inguinal cryptorchism and one with infertility). The seminiferous tubules of all patients showed a moderate to marked thickening of the boundary layer and a complete loss of spermatogenic cells. The "ectopic Leydig cells" were characterized by the presence of Reinke crystals or an extensively developed smooth endoplasmic reticulum. These cells were believed to have differentiated in situ from myoid cells within the boundary layer and also to have invaded from the interstitial tissue in the form of mature Leydig cells. The occurrence of ectopic Leydig cells appeared to parallel the extent of loss of the Sertoli cells and also that of the thickening of the boundary layer. The functional significance of the ectopic occurrence might be implicated in the impaired spermatogenesis.

Adult↗
PubMed1987

Induction of subcutaneous tumors in rats by 3,7- and 3,9-dinitrofluoranthene.

Two dinitrofluoranthenes (DNFs) derived from 3-nitrofluoranthene were purified to over 99%, and tested for tumorigenicity in F344/DuCrj male rats. Rats were inoculated s.c. with 0.05 mg 3,7- or 3,9-DNF twice a week for 10 weeks. All 21 rats given 3,7-DNF and 10 of 11 rats (91%) given 3,9-DNF developed tumors at the injection site by 48 weeks after the first injection. Twenty of the 21 tumors induced by 3,7-DNF and seven of the 10 tumors induced by 3,9-DNF were classified as malignant fibrous histiocytoma, but one tumor in the 3,7-DNF-treated group and three tumors induced by 3,9-DNF showed typical features of rhabdomyosarcoma. The first tumors in 3,9-DNF-treated rats appeared on day 88 (on day average 117), 10 weeks earlier than in 3,7-DNF-treated ones (on day average 186).

Animals↗
PubMed1987

Collagen-producing mesothelial cells in adriamycin-induced pleuritis in rat. Microautoradiographic study utilizing tritiated proline.

By the microautoradiographic method using 3H-proline, collagen production by mesothelial cells was investigated in adriamycin-induced pleuritis in rats. In subpleural granulation tissue formed at 4 to 7 days after the intrapleural injection of adriamycin, proliferating fibroblasts and primitive mesenchymal cells were most intensely labeled, and abundant deposition of collagen and acid mucopolysaccharides were demonstrated about these cells. It is thus concluded that these subpleural mesenchymal cells are mainly responsible for the fibrosing process. Labeling was also observed in some reactive mesothelial cells and macrophages free-floating in the pleural exudate. Several ultrastructural differences between labeled mesothelial cells floating in the fluid and lining the pleural surface were confirmed, suggesting a change in ability to synthesize collagen during mesothelial desquamation. It seems likely that these labeled mononuclear cells in the effusion, attached to the pleural wound surface, support fibrosis performed by underlying collagen-synthesizing mesenchymal cells. Pleural fibrosis disappeared by 10 days, when mesothelial regeneration was almost complete. Probably this change may be due to fibrinolytic activity caused by regenerative mesothelial cells derived from subpleural mesenchymal cells.

Animals↗
PubMed1987

Individualization of patients for adjuvant chemotherapy after surgical treatment of cervical cancer.

Adjuvant chemotherapy using Tegafur (1-(2-tetra hydrofuryl)-5-fluorouracil) was given to 52 of 216 patients with recurrence risk of cervical cancer after primary surgical treatment, the degree of risk of recurrence having been formulated as a discriminant function by computer analysis of risk factors involved in disease recurrence. Using the formula, we have managed outpatients in three groups--no recurrence and recurrence after, and before 5 years. Under existing circumstances the power of the discriminant function we have achieved is not yet entirely satisfactory although clinically of value in patient management. Oral, long-term adjuvant chemotherapy in risk groups was of value, with a 37.4% instantaneous recurrence rate and mild side-effects. An instantaneous recurrence rate of 37.4% signifies that the recurrence rate in the group of patients given chemotherapy would be 37.4% if it were 100% in the patients not so treated--an improvement factor of just less than 3.

Adult↗
PubMed1987

Long-term follow-up study of nucleus ventralis intermedius and ventrolateralis thalamotomy using a microelectrode technique in parkinsonism.

Long-term observation over 3-8 postoperative years of cases of Parkinson disease operated by stereotactic thalamotomy using a microelectrode recording technique is reported. The procedure is specifically useful in the following four groups: (1) tremor-dominant cases, (2) hemiparkinsonism, (3) cases with marked asymmetry in motor symptoms and (4) juvenile parkinsonism presenting levodopa-induced dyskinesia.

Follow-Up Studies↗
PubMed1987

Immunohistochemical study of mononuclear cell infiltrates in squamous cell carcinoma of oral cavity and paranasal sinus.

Serial frozen sections were prepared from 22 squamous cell carcinomas of oral cavity and paranasal sinus. Mononuclear cell infiltrates were stained by the biotin-avidin-horseradish peroxidase method using a panel of 10 mouse monoclonal antibodies to human leukocyte antigens. The degree of infiltration was graded from + + + (marked) to - (absent). The infiltration of anti-Leu-4-reactive cells (Leu-4+ cells) was grade + + or + + + in 14 of 22 cases. In 13 of 22 cases, infiltration of Leu-3a + 3b+ cells (helper/inducer T lymphocytes) was grade + + (moderate). In 5 of 20 cases, infiltration of Leu-2a+ cells (cytotoxic/suppressor T lymphocytes) was grade + +. As for B lymphocytes, infiltration of Leu-12+ cells was grade + + in only 2 of 19 cases. In conclusion, T lymphocyte infiltrates were commonly seen in squamous cell carcinoma in oral cavity and paranasal sinus and the number of patients with grade + + infiltration of helper/inducer T lymphocytes significantly predominated over that of patients with infiltration of cytotoxic/suppressor T lymphocytes grade + +.

Adult↗
PubMed1987

Potentiation by bovine serum albumin (BSA) of endothelium-dependent vasodilator response to acetyl glyceryl ether phosphorylcholine (AGEPC).

Endothelium-dependent vasodilator responses of isolated rat aortic strips precontracted with norepinephrine to acetyl glyceryl ether phosphorylcholine (AGEPC) were compared in the presence and absence of bovine serum albumin (BSA). In the absence of BSA, AGEPC produced endothelium-dependent relaxation at concentrations higher than 10(-6) M, which was considered to be non-specific because similar relaxations were produced by other phospholipids (e.g., lysolecithin) at the same concentration range. This non-specific relaxation was suggested to be caused by changes in membrane fluidity of endothelial cells, since high concentrations of AGEPC and other phospholipids were found to produce structural changes in endothelial cells by phase contrast and electron microscopic studies; structural changes were never observed after the application of acetylcholine (ACh). In the presence of BSA (2.5 mg/ml), AGEPC caused endothelium-dependent relaxation at concentrations as low as 10(-9)M; however, relaxations by ACh and lysolecithin were not augmented by the presence of BSA. CV-3988 (10(-5)M), a specific antagonist of AGEPC, inhibited the relaxations by AGEPC in the presence of BSA. From these results, it is suggested that, in the presence of BSA, AGEPC may produce endothelium-dependent relaxation in a specific manner, which is different from the non-specific relaxations observed in the absence of BSA.

Animals↗
PubMed1987

Sensory innervation of the periodontal ligament in the incisor and molar of the monkey, Macaca fuscata. An immunohistochemical study for neurofilament protein and glia-specific S-100 protein.

Nervous elements in the periodontal ligament of the monkey, Macaca fuscata were investigated by means of immunohistochemistry for neurofilament protein (NFP) and S-100 protein. Thick nerve bundles with NFP-immunoreactivity entered the periodontal ligament through slits at the bottom of the alveolar socket, whereas thinner bundles, also NFP-immunoreactive, penetrated the ligament from the lateral wall of the alveolar socket. The NFP-immunopositive nerve fibers were densely distributed around the root apex in both incisors and molars. In the upper incisors, another dense distribution of NFP-positive nerves was found in the apical half of the lingual periodontal ligament and in the coronal half of the labial periodontal ligament. The periodontal nerve fibers in the incisors ramified in a dendritic fashion, terminating as free nerve endings within the periodontal ligament. Immunostaining for S-100 protein demonstrated the Schwann sheaths of nerves which showed the same distribution pattern as that of the NFP-immunopositive fibers in the periodontal ligament of the incisors. In molars, immunostaining for NFP and S-100 showed that nerves were numerous in the apical region of the periodontal ligament. However, NFP-immunopositive nerves were fewer than the S-100-positive nervous elements in the apical region in molars. This discrepancy suggests the presence of NFP-immunonegative nerves. Immunostaining for S-100 is thus useful for demonstration of neural elements in the periodontal ligament of molars. The S-100-immunoreactive neural elements in the periodontal ligament were more numerous in incisors than in molars. In addition to the free nerve endings, a small population of coiled nerve endings was observed in the periodontal ligament of molars. Most of the nerve fibers and cell bodies in the trigeminal ganglion showed NFP-immunoreactivity, whereas all in the mesencephalic nucleus of the trigeminal nerve were negative in NFP-reaction. This finding suggests that the periodontal ligament of molars receives a dual innervation from the trigeminal ganglion and mesencephalic nucleus.

Animals↗