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Biomedical subjects

H Nagata

Publications and source records attributed to H Nagata.

At least 289 records · Page 16Linked to original sources
PubMed1988

Induction of lymph follicle formation with endotoxin lipopolysaccharide in the draining lymph node of athymic nude mice.

Formation of lymph follicles in draining popliteal lymph nodes in athymic nude mice and their phenotypically normal littermates (PN mice) was investigated after footpad injection with either endotoxin lipopolysaccharide (LPS) or phytohemagglutinin in soluble and precipitated forms (PHA). The dose of LPS injected ranged from 10 to 100 micrograms, and that of PHA was 50 micrograms. After any dose of LPS, draining nodes of nude mice produced new lymph follicles in the peripheral cortex outside pre-existing follicles, though the number of follicles induced was somewhat less than in the case of PN mice treated with LPS. After injection of PHA in soluble or precipitated form, PN mice developed a significant number of new follicles in the draining nodes, but nude mice failed to do so. The present results are consistent with the view that nude mice have the ability to develop lymph follicles by way of a thymus-independent mechanism in response to exogenous stimuli.

Animals↗
PubMed1988

Cytochemical demonstration of actin filaments in myoepithelial cells of the human parotid gland.

Ultrastructurally, myoepithelial cells were shown to contain numerous fine filaments in their cytoplasm and resembled smooth muscle cells. The myoepithelial cell of the salivary gland has been considered to play an important role in the secretion of saliva. The present study showed that all the thin filaments (actin filaments) in the myoepithelial cell of the human parotid gland bound heavy meromyosin (HMM) and formed characteristic arrowhead structures. These filaments ran in two opposite directions with the poles at different ends. On the other hand, there was no binding of HMM with thicker filaments (10-nm filaments), plasma membrane, nuclear membrane, collagen fibrils, basement membrane or other cytoplasmic organelles. The present results strongly suggest that myoepithelial cells possess a contractile function parallel to the long axis of the cell for supporting the secretion of saliva in the parotid gland.

Actin Cytoskeleton↗
PubMed1988

Ultrasonographic evaluation of adrenal involution during antenatal and neonatal periods.

Using real-time ultrasonography, 25 adrenal glands from prenatal to neonatal periods were prospectively examined to assess the process of shrinkage. A similar sonographic structure was seen in both prenatal and neonatal adrenal glands. The area of adrenal gland (AGA) and the rate of decrease were calculated during antenatal and early neonatal periods. The values of AGA were 350 +/- 19 mm2 within a week of delivery, 304 +/- 17 mm2 (87 +/- 2%) just after delivery, 273 +/- 25 mm2 (77 +/- 5%) on the 1st day, 246 +/- 24 mm2 (70 +/- 5%) on the 2nd day, 215 +/- 23 mm2 (61 +/- 5%) on the 3rd day, 196 +/- 22 mm2 (56 +/- 5%) on the 4th day, 173 +/- 18 mm2 (50 +/- 4%) on the 5th day, 154 +/- 14 (44 +/- 4%) on the 6th day, 140 +/- 12 mm2 (40 +/- 2%) on the 7th day, respectively. In conclusion, the postnatal involution of the adrenals was documented by ultrasound.

Adrenal Glands↗
PubMed1988

Clinical usefulness of determination of CA 125 levels in the serum and menstrual blood.

We measured CA 125 levels in sera and menstrual blood of subjects with a normal ovulatory cycle and in those with endometriosis. Serum CA 125 levels were higher in the latter, in each phase of the menstrual cycle. The CA 125 levels in patients with endometriosis, particularly those with adenomyosis, tend to be higher than in those with a normal ovulatory cycle. We propose that measurement of CA 125 in the menstrual blood may be able to help distinguishing adenomyosis from myoma uteri and may also help in assessing clinical endometriosis.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1988

5-lipoxygenase inhibitor (AA-861) attenuates neutrophil-mediated oxidative stress on the venular endothelium in endotoxemia.

Neutrophil-mediated oxidative stress on the rat mesenteric microcirculation was studied in the experimental model of endotoxin-induced disseminated intravascular coagulation (DIC) by using an intravital fluorescent microscope equipped with a Silicon Intensifier Target Image Tube camera and luminol-dependent chemiluminescence (ChL) analysis. Leukocytes adhering to the venules were visualized by the injection of acridine orange, a fluorochrome tracer which shows high affinity to white cells. Endotoxin (E. coli, O-111 B4) was administered intravenously at a dose of 2 mg/kg/hour. After starting the infusion of endotoxin, the number of adherent cells gradually increased in the venular endothelium and was followed by a transient neutropenia. ChL activities from neutrophils were also significantly elevated, which may reflect the enhanced ability to generate oxygen-radicals. To elucidate the role of 5-lipoxygenase products in the locomotive and metabolic changes of neutrophils, the effects of AA-861, a specific inhibitor of 5-lipoxygenase was tested. In addition prednisolone and indomethacin were evaluated. AA-861 and prednisolone reduced neutropenia, leukocyte adhesion to the venular walls and ChL activities from neutrophils. It was concluded that 5-lipoxygenase may modulate neutrophil-mediated oxidative stress on microvasculature in endotoxin-induced DIC.

Acridine Orange↗
PubMed1987

Slow axonal transport in experimental hypoxia and in neuropathy induced by p-bromophenylacetylurea.

The slow axonal transport of proteins radiolabeled by incorporation of [35S]methionine was studied in motor nerves of rats subjected to chronic hypoxia. The conditions involved exposure to an atmosphere of 8-10% oxygen for periods of 3, 5, or 10 weeks. An experimentally verified computer model predicted a drop in mean endoneurial oxygen tension from 30.5 to 19 mm Hg, despite a measured increase in circulating hemoglobin from 16 to 22 g%. Nerve conduction velocity was unaffected during the early stages of hypoxia. After 10 weeks of hypoxia, conduction velocity still appeared normal in the sciatic nerve but was reduced in the caudal nerve by 2.5-4.5 m/s. At no time, however, was there evidence of impaired slow axonal transport, which proceeded with a mean velocity between 1 and 2 mm/day. Another set of experiments was performed to evaluate slow axonal transport in motor nerves of rats with peripheral neuropathy induced by the toxicant, p-bromophenylacetylurea. The results suggested a lower transport velocity in rats showing total hind-limb paralysis as compared with rats showing only mild to moderate motor dysfunction. The difference, however, could have reflected accelerated transport in mild neuropathy. In our view, the observations in experimental hypoxia- and toxicant-induced neuropathy are noteworthy for the resistance of slow transport to perturbation of the neuronal environment.

Animals↗