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Biomedical subjects

K Usui

Publications and source records attributed to K Usui.

At least 109 records · Page 6Linked to original sources

The amino acid sequence of coagulogen isolated from southeast Asian horseshoe crab, Tachypleus gigas.

The amino acid sequence of coagulogen isolated from Southeast Asian horseshoe crab (Tachypleus gigas) has been determined. The NH2-terminal sequence of the first 51 residues was obtained by automated Edman degradation. The intact protein was then treated with a Tachypleus clotting enzyme, to form a gel and to remove an internal peptide C (28 residues) located near the NH2-terminal portion. The gel protein, which consisted of A chain (18 residues) and B chain (129 residues), was S-alkylated and the resulting two chains were separated by acetone precipitation. Among these segments, A chain and peptide C were assigned to the NH2-terminal portion of whole coagulogen, as judged from their amino acid compositions. On the other hand, the covalent structure of B chain was determined by sequencing the peptides obtained from its tryptic digest. The alignments of the tryptic peptides were deduced from the sequence homology in comparison with the previously established B chain sequence of Japanese horseshoe crab (T. tridentatus) coagulogen. T. gigas coagulogen had a total of 175 amino acids and a calculated molecular weight of 19,770. When the sequence was compared with those of Japanese and American horseshoe crab (Limulus polyphemus) coagulogens, extensive structural homology was found: T. tridentatus/T. gigas, 87% and L. polyphemus/T. gigas, 67%. This comparison suggests that Japanese and Southeast Asian horseshoe crabs have a crab, based on amino acid sequence data.

Amino Acid Sequence↗

Follicular development and a single ovulation induced with pulsatile administration of Gn-RH in anovulatory women: studies of hormonal analysis and follicular sonometry.

The method of pulsatile administration of gonadotropin-releasing hormone (Gn-RH) has been proven as a useful means for induction of ovulation in anovulatory women. In our series of clinical trials, 23 out of 29 anovulatory patients ovulated with pulsatile administration of Gn-RH. Seven patients who ovulated volunteered for the present study with daily hormonal analysis and follicular sonometory . Two patients have oligomenorrhea, 3 patients secondary amenorrhea-1st grade (the sole administration of gestagen required for withdrawal bleeding) and the remaining 2 patients secondary amenorrhea-2nd grade (the combined administration of estrogen and gestagen required for withdrawal bleeding). A diagnosis of hyperprolactinemia was made for one patient with secondary amenorrhea-1st grade. Pulsatile administration of Gn-RH was performed by the use of a self-administered infuser . The infuser was connected to an i.v. indwelling catheter via a specially designed blood backflow eliminater . Five micrograms or less of Gn-RH was given every 2 hr from 07:00 to 23:00 hr daily. Five patients received HCG during the preovulatory period. In one patient, a short term treatment of HMG was added to Gn-RH treatment. Follicular sonometry revealed the development of a single dominant follicle which reached between 20 and 28 mm (23.7 +/- 0.12 mm, mean +/- S.E.) in diameter at the preovulatory period. Disappearance of a dominant follicle was recognized in the early luteal phase. Characteristic increases in estradiol were recognized concomitantly with the development of a dominant follicle. Progesterone levels after ovulation were within the limits of its normal "luteal phase" rise. The present data suggest that pulsatile administration of low dose Gn-RH with nocturnal interruption of treatment is effective for normal progress of follicular development in various types of anovulatory patients, culminating in single ovulation. This paper includes the discussion on our method which may be responsible for a high success rate of ovulation induction.

Adult↗

[Malignant intracranial lymphoma--clinical and patho-immunological study].

Clinical and patho-immunological study was made on 15 cases of primary intracranial malignant lymphoma. The average age of the patients was 45.2, however older man suffered more than younger one. Male to female ratio was 3:2. The duration between onset to diagnosis was less than 6 months in 13 cases. The common signs and symptoms were hemiparesis (60%) and signs of intracranial hypertension (45%), followed by disturbance of consciousness, visual disturbances, convulsion and signs of inflammation. The location of the lesions was in parietal lobe (44%), temporal lobe (27.8%), cerebellum (22.2%), brain stem and basal ganglia (18%). Multiple lesions were found in 4 cases. CT scan was the most diagnostic method not only to delineate the location of lesions but also to recognize the biological natures of this condition. The radiosensitivity of this tumor was also confirmed by follow-up CT scans during radiotherapy. Most of the lesions were avascular by carotid angiography, but capillary blush at the tumor site was shown in some cases. Laboratory findings revealed that derangement of gamma globulin in the serum and decline of cellular immunity were demonstrated in many cases. Surgical removal followed by whole skull irradiation was made in all cases except one. Remission of neurological signs and symptoms with disappearance of lesions on CT scan was obtained in 7 cases for one to 9 months. All cases except two survival, died during 3 to 28 months (average: 10.1). Survival rate at one year and 2 years was 35.7% and 14.3% respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗