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Biomedical subjects

T Fuwa

Publications and source records attributed to T Fuwa.

At least 73 records · Page 4Linked to original sources

Long-latency growth-promoting activity of EGF when administered to mice at the neonatal stage.

The effect of biosynthetic human epidermal growth factor (Bh-EGF) as well as mouse EGF on postnatal development of mice of ICR strain was examined. Daily administration of Bh-EGF (0.01, 0.1, and 1.0 microgram X g body wt-1 X day-1) for 30 consecutive days postpartum caused a clearly dose-dependent increase in their body weight. Furthermore, in addition to the well-known premature eyelid opening and early tooth eruption, we have also observed precocious opening of the vagina among treated females. As far as the accelerated growth rate as reflected in their body weight gain was concerned, daily administration for only five consecutive days postpartum was just as effective as the above noted 30 consecutive daily injections. As to the precocious vaginal opening, however, the susceptible 5-day-period was found to be 14-18 days after the parturition. Some of those treated females also entered the estrous cycle precociously, a few days after the precocious opening of their vagina. The microscopic examination of various organs from treated males and females revealed no apparent pathological changes. As far as the above noted effects of EGF were concerned, Bh-EGF, which is xenogenic to mice, was as potent as mouse EGF.

Animals↗

Burst discharges of pontine reticular neurons in relation to forelimb stepping of thalamic and high spinal cats.

The paralemniscal pontine reticular neurons (PLRF) exhibited burst discharges when thalamic cats stepped on the moving treadmill, during stepping induced by mesencephalic locomotor region (MLR) stimulation, fictive locomotion by MLR stimulation after immobilization and during MLR stimulation after transection at the C2 level. These results imply that MLR stimulation can evoke burst discharge within the brainstem which may obtain alternating limb movements via descending tract to the cervical cord.

Animals↗

Synthesis and secretion of human epidermal growth factor by Escherichia coli.

A synthetic gene for human epidermal growth factor (hEGF) was joined to a sequence encoding the signal peptide of Escherichia coli alkaline phosphatase. This hybrid gene was placed under the control of the alkaline phosphatase gene (phoA) promoter in a recombinant plasmid, which was used to transfect E. coli. The hybrid protein that was expressed in host cells under conditions of phosphate limitation was processed accurately during the secretion process, and mature hEGF was recovered in the periplasmic fraction. On the other hand, no EGF was detected in the periplasmic space when the synthetic hEGF gene was not accompanied by the phoA signal sequence.

Alkaline Phosphatase↗

Secretion of human interferon-alpha induced by using secretion vectors containing a promoter and signal sequence of alkaline phosphatase gene of Escherichia coli.

We constructed a new vector containing the promoter and the signal sequence of E. coli phoA gene, the structural gene for the periplasmic alkaline phosphatase. One of the most useful characteristics of this vector is the unique HindIII restriction site located just at the end of the phoA signal sequence. This restriction site was generated by oligonucleotide-directed site-specific mutagenesis without changing the amino acid sequence of the signal peptide. Any kind of foreign structural gene can be easily inserted into the HindIII site by using synthetic oligonucleotides to construct a hybrid gene which has neither an extra sequence nor a deletion between the phoA signal sequence and the foreign structural gene. Human alpha-interferon gene was inserted into this HindIII site. When this hybrid gene was expressed under the control of the phoA promoter region, a low but significant activity was recovered in the cold water wash of the cells after an osmotic shock procedure.

Alkaline Phosphatase↗

Biological effects of biosynthetic human EGF on the growth of mammalian cells in vitro.

The effects were examined of biosynthetic human epidermal growth factor (Bh-EGF) produced from cloned E. coli on DNA synthesis and all divisions of 13 different kinds of primary and established cell lines. Primary cultures of mammary epithelia, hepatocytes and stomach cells were strongly stimulated by EGF to undergo DNA synthesis in serum-free culture medium with concentrations of Bh-EGF as low as 0.1-10 ng/ml. In sharp contrast, 0.1-100 ng/ml of Bh-EGF failed to enhance thymidine incorporation into DNA when applied to established cell lines using the serum-free medium. Higher concentrations of Bh-EGF (30-100 ng/ml) promoted morphological changes only in hepatocytes, e.g., elongation, enlargement and projection of their cytoplasm. The above results were also obtained in mouse EGF (m-EGF). In our binding assay, Bh-EGF competed against [125I]-m-EGF with a one-fourth to one-fifth efficacy when compared with m-EGF. It was concluded that the in vitro biological activity of Bh-EGF was similar to that of m-EGF.

Animals↗

Role of joint afferents in relation to the initiation of forelimb stepping in thalamic cats.

To analyze the roles of joint afferents in relation to initiation of forelimb stepping in thalamic cats, we recorded the unit spikes of the cervical dorsal roots, stimulated the joint afferents, and applied local anesthesia to the joint capsule. Almost all of the joint afferents of the shoulder, elbow, wrist and finger adapted slowly and exhibited alternating firing during forelimb stepping. About 45% of the afferents of each joint showed firings as the limb moved from forward to backward. About 44% of the afferents exhibited discharges as the limb moved from backward to forward. The remaining afferents showed firings as the limb moved in both directions. The application of local anesthesia to joints of the shoulder, elbow or wrist resulted in a marked reduction of forelimb stepping. Forelimb stepping was evoked by electric stimulation of the joint capsule, when excitabilities of flexor motoneurons were increased due to muscle stretching. Impulses originating in the joint afferents of the forelimb entered the spinal cord and ascended to the dorsolateral funiculus of the cervical cord, since forelimb stepping was abolished after bilateral transection of this part. Our results indicate that joint afferents may play an important role in the initiation of forelimb stepping in thalamic cats walking on a motor-driven treadmill.

Afferent Pathways↗

[Effect of raw and extracted-aged garlic juice on growth of young rats and their organs after peroral administration (author's transl)].

The effects of peroral administration of raw garlic juice and extracted-aged garlic juice (garlic extract) were studied with female Wistar strain rats. For the examination, 5, 5 and 10 rats were sacrificed after 3, 8 and 21 days respectively. In the group to which raw garlic juice (5 ml/kg) was administered 5 rats died of the serious stomach injury in 21 days and body weight of still living rats was down at the beginning as food and water intake were decreased. The growth of rats to which raw garlic juice administered group was retarded. The retardation of growth was thought to be caused by the stomach injury due to raw garlic, which limited in fundus. The injured section of stomach was not far gone by the longer administration, however, the mucous secretion of the surface and neck area were stimulated. Swelling of the liver, hypertrophy of the spleen and adrenal glands, and the decrease of erythrocytes with various morphological changes were clearly observed after 3 and 8 days on the group dosed high raw garlic juice, but almost these changes were not observed at any time on extracted-aged garlic juice administration.

Administration, Oral↗