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Biomedical subjects

K Fujii

Publications and source records attributed to K Fujii.

At least 775 records · Page 43Linked to original sources
PubMed1987

[A case of breast carcinoma, possibly the result of malignant transformation of an intraductal papilloma in a 26-year period].

A 74-year old female presented a giant tumor and serosanguineous nipple discharge from the left breast. The tumor was first recognized 26 years ago, and untreated. The resected breast contained several cysts and some small white nodules. Some of the cysts contained intracystic tumors. Histologically, the tumor consisted of a mixture of papillotubular carcinoma and intraductal papilloma. This case seems to represent a malignant change in intraductal papilloma from its long clinical course and by the microscopic findings. Review of this case seems to warrant clinical attention to the possibility that benign intraductal papilloma may transform itself into malignancy after many years.

Adenocarcinoma↗
PubMed1986

Stimulatory effect of calmodulin antagonists on phospholipid base-exchange reactions in rabbit platelet membranes.

The properties of Ca2+-dependent incorporation of [3H]serine, [3H]ethanolamine and [3H]choline into the corresponding phospholipids mediated by base-exchange enzymes in rabbit platelet membranes were studied in the presence or absence of the calmodulin antagonists chlorpromazine, trifluoperazine and N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7), all of which markedly activate three base-exchange reactions. The base-exchange activities were dependent on Ca2+ both in the presence and absence of the drugs. Other metal ions tested did not stimulate the base-exchange reactions, even in the presence of the drugs. Apparent Km values for serine, ethanolamine and choline were not affected significantly by the concentration of Ca2+, with or without the drugs. [3H]Serine incorporation into phospholipid was competitively inhibited by ethanolamine and choline, [3H]choline incorporation was competitively inhibited by serine and ethanolamine, whereas [3H]ethanolamine incorporation was competitively inhibited by serine and noncompetitively by choline. These competitive and noncompetitive relations between each base were also not affected by the drugs. The amount of 45Ca2+ binding to platelet membranes was decreased by the drugs dose dependently. A weaker calmodulin antagonist, N-(6-aminohexyl)-1-naphthalenesulfonamide (W-5), only slightly stimulated the base-exchange reactions, but did clearly inhibit 45Ca2+ binding to the membranes, in the same manner as that of the other calmodulin antagonists used. The concentration of chlorpromazine, trifluoperazine, W-7 and W-5, required to produce half-maximal inhibition of Ca2+ binding, was approximately 30 microM. These results suggest that the calmodulin antagonists used activate the base-exchange reactions only in the presence of Ca2+ without changing the affinity of each free base to base-exchange enzymes. The activation of the base-exchange reactions was not due to the increase in free Ca2+ caused by the drug-induced inhibition of Ca2+ binding to platelet membranes.

Animals↗
PubMed1986

Effect of chronic sympathetic denervation on cerebrovascular hypertrophy during the development of hypertension in rats.

The present study was designed to examine the trophic effect of sympathetic nerves on cerebrovascular hypertrophy in developmental hypertension. Unilateral superior cervical ganglionectomy was performed in spontaneously hypertensive rats at 4 weeks of age, and wall-to-lumen ratios of cerebral arteries were determined at 5 weeks, 2 months or 5 months after denervation. To estimate the thickness of the vessel wall, a freeze substitution technique was used for the preparation of cerebral arteries. Basal mean arterial blood pressure measured through cannulated femoral artery was 127 +/- 2, 146 +/- 7 and 168 +/- 6 mm Hg (mean +/- S.E.M.) at 9 weeks, 3 months and 6 months of age, respectively. The wall-to-lumen ratios in the denervated and innervated hemispheres were 0.124 +/- 0.004 and 0.129 +/- 0.005 at 9 weeks, 0.127 +/- 0.003 and 0.169 +/- 0.004 (P less than 0.02 vs denervated) at 3 months, and 0.194 +/- 0.007 and 0.222 +/- 0.006 (P less than 0.05 vs denervated) at 6 months. The effect of denervation was more significant in downstream vessels (diameter less than or equal to 100 microns) than larger ones. We conclude that wall-to-lumen ratio is correlated well with a rise in basal blood pressure, and chronic interruption of the sympathetic nerves attenuates normal occurrence of vascular hypertrophy during the development of hypertension.

Animals↗
PubMed1986

Isolation of peripheral nerve collagen.

A new method for the isolation of high yields of collagen from human peripheral nerve is described. A major technique adopted in the present work is sedimentation of the tissue homogenates in a sucrose density gradient. The defatted fibrous material isolated after the removal of myelin was shown to be a relatively pure collagenous substance by amino acid analysis, indicating that the removal of noncollagenous proteins, especially glycoproteins, from collagen fibrils was effectively achieved by this method. The yield of collagen at this step was more than 90% of the total collagen in peripheral nerve. Subsequent extractions with solutions of neutral saline and sodium citrate were found to give further purification of the collagenous protein. The collagens from embryonic peripheral nerves were composed of Type I and III collagens, while Type III collagen was found to be less abundant in adult peripheral nerves.

Adult↗
PubMed1986

Peripheral nerve involvement in familial chorea-acanthocytosis.

Myelinated fibers and neuronal cell bodies of the ventral spinal outflow and primary sensory neurons were histopathologically examined in a patient with familial chorea-acanthocytosis and age-matched controls. The patient exhibited a marked loss of large myelinated axons and their neuronal cell bodies in the ventral spinal outflow, while there was frequent occurrence of axonal sprouts. Large myelinated fibers in sensory afferents were also decreased in number. Segmental de- and remyelination was markedly increased in teased fiber preparations of both motor and sensory peripheral nerves.

Acanthocytes↗
PubMed1986

The responsiveness of Clare-Bishop neurons to size cues for motion stereopsis.

The responsiveness to the size cue, and a combination of the size and motion cues contained in 3-dimensional motion of a visual stimulus was studied in 118 Clare-Bishop (CB) cells, including 37 and 10 cells selectively responsive to approaching (AP) and to recessive motion along the axis through the center of the receptive area and the nose (RC), 40 cells responsive to the frontoparallel motion in the horizontal direction (FP), 23 cells rather non-selectively responsive to the two types of motion (NS) and 8 cells responsive to the size cue but unresponsive to the 3-dimensional motion (SZ). About three quarters of the AP cells (27/37) were responsive to both an increase in the stimulus size and divergent motion of the retinal images in the two eyes, which represents the size and motion cues for the approaching motion along the axis through the center of the receptive area and the nose, and were optimally excited by a combination of the two visual cues. About the same fraction of the RC cells (6/10) was responsive to the motion (convergent motion) and size cues (a decrease in stimulus size), and optimally excited by a combination of the two visual cues. In contrast, only a small fraction of the FP cells (6/40) were sensitive to the size cue, and all FP cells were optimally excited by the single presentation of the motion cue for the frontoparallel motion (either right- or leftward motion in both eyes). Responses were frequently (18/40) smaller for the combined presentation of the two visual cues than for the single presentation of the motion cue. Similarly, a small fraction of the NS cells (7/23) was sensitive to the size cue, but many of them (16/23) were non-selectively responsive to the size cues for the approaching and recessive motion. A similar study in an additional 108 (78 AP and 30 RC) cells which were responsive to approaching or recessive motion vertically or obliquely deviating from the axis through the center of the receptive area and the nose demonstrated that they were also sensitive to both motion and size cues for that approaching or recessive motion, and were optimally excited by a combination of the two visual cues. These findings indicate that the CB cell responsiveness to 3-dimensional motion is based on the integration of the motion and size signals conveyed through the two eyes. A model of neuronal circuitry was constructed to explain the CB cell responsiveness to the motion and size signals.

Action Potentials↗
PubMed1986

Increased release of prostaglandins from the mesenteric vascular bed of diabetic animals: the effects of glucose and insulin.

To study prostaglandin (PG) metabolism in peripheral vascular beds, PGs and TxB2 released from perfused mesenteric tissues were measured in both normal and streptozotocin (STZ)-induced diabetic rats. The release of 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha), thromboxane B2 (TxB2) and prostaglandin E2 (PGE2) was significantly increased in mesenteric vascular beds from diabetics in comparison with control rats. The 6-keto-PGF1 alpha/TxB2 ratio was decreased in diabetics. In order to clarify the mechanism of this imbalanced synthesis of eicosanoids, we infused buffer with 500 mg/dl glucose which was similar to the concentration of blood glucose in the diabetic rats. In response to this high glucose concentration, TxB2 released into the effluent from the mesenteric beds of normal animals was increased to the diabetic level. The release of the other PGs was not changed significantly. The 6-keto-PGF1 alpha/TxB2 ratio was decreased in control rats perfused with buffer containing 500 mg/dl glucose. We also investigated the effect of insulin (50 and 100 microU/ml) in the diabetic mesenteric vascular beds, but there were no changes in prostaglandin or TxB2 release. These data suggest that a high glucose level may have an important role in regulating TxA2 synthesis and in modulating the balance between PGI2 and TxA2 in diabetes. It is postulated that an increase in the micro-circulation of PGI2 may partially be protective against the progression of angiopathy.

6-Ketoprostaglandin F1 alpha↗
PubMed1986

Mandibular ameloblastoma with intracranial extension and distant metastasis.

A case of mandibular ameloblastoma which invaded intracranially through the skull base and developed distant metastasis to the femur is reported. The intracranial extension of the tumor was partially removed three times and the metastasis of the femur was curetted. The remaining tumor temporarily responded to chemotherapy, but the patient died of intracranial tumor regrowth. The period from the initial treatment of the mandibular tumor to death was 21 years.

Adult↗