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Biomedical subjects

K Kokubo

Publications and source records attributed to K Kokubo.

At least 19 recordsLinked to original sources
PubMed2001

Pure Kana agraphia as a manifestation of graphemic buffer impairment.

We report a left-handed man who demonstrated a pure agraphia limited to words written in Kana characters (syllabograms) following a right putaminal hemorrhage. Writing words in Kanji characters (logograms) was well preserved. His performance in Kana writing was characterized by intact ability to write single syllables, error increase in the second half of words directly proportional to the word length and correct but slow writing of words using kana blocks. Errors were more prominent in Hiragana words than Katakana words which are usually used to transcribe foreign words. Acoustic-grapheme sequencing per se was not impaired as shown by his correct performance in arranging character blocks. These findings suggest selective damage to the graphemic buffer, a module that temporarily maintains the graphemic representation elaborated in previous stages before it is sent to the peripheral systems for its motor realization.

Aged↗
PubMed2000

Regio- and endo-selective

Irradiation of various meta- and para-substituted homobenzoquinones with ethyl vinyl ether gave the [2 + 2] photoadducts, tricyclic diones, regio- and endo-selectively and in good yields. The tricyclic skeleton has an anti-form built by the addition of ethyl vinyl ether from the less hindered side of homoquinones. All of the CH(3), Cl, Br, and CH(3)O substituents at the reacting C=C double bond afforded head-to-head (HH) addition predominantly. In the case of CH(3), Cl, and Br, the ethoxy group was oriented in the endo-position, while the CH(3)O substituent led to a 1/5 mixture with the exo-isomer. It was also found that the Br-substituted [2 + 2] adducts undergo a facile skeletal rearrangement, being converted into dihydro-o-benzoquinone monomethide derivatives for para-substitution and dihydrobenzofuran derivatives for meta-substitution, probably under the influence of the in situ generated HBr. Intramolecular [2 + 2] photocycloaddition of an alkenylhomobenzoquinone afforded a tetracyclic dione.

Journal Article↗
PubMed1999

New method for determining the sugar composition of glycoproteins, glycolipids, and oligosaccharides by high-performance liquid chromatography.

A new method is reported that can be performed within a single vessel to analyze the composition of aldose, hexosamine, and sialic acid residues of glycoproteins, glycolipids, and oligosaccharides. Glycoconjugates are treated with sialidase or subjected to mild acid hydrolysis, before being treated with N-acetylneuraminic acid aldolase to convert the free sialic acid residues to their corresponding N-acylmannosamines. The reaction mixture is then successively subjected to acid hydrolysis (in order to produce monosaccharides), N-acetylation, and conversion with p-aminobenzoic acid ethyl ester (ABEE). The ABEE-converted monosaccharides are simultaneously determined by reverse-phase high-performance liquid chromatography. Determination of the sugar compositions of bovine fetuin, II3NeuGc alpha-LacCer, and 3'-sialyllactose with this method was found to be highly accurate. Linearity of the peak area vs. the amount of bovine fetuin ranged from 1 to 50 micrograms in all ABEE-converted monosaccharides. With a slight modification to this method, sialic acid residues can be separately determined as NeuAc and NeuGc. This novel method and its modified version are used to demonstrate the sugar compositions of alpha 1-acid glycoproteins from several sources.

Acetylation↗
PubMed1997

[A case report of localized fibrous pleural mesothelioma].

A 47-year-old female with localized fibrous pleural mesothelioma arising from the visceral pleura of S2 of rt-upper lobe is reported. We demonstrated an indirect radiographic sign of pedunculation which was the change in position of the mass with the change in patient's position. The tumor was completely extirpated with a partial resection of the adjacent lung tissues through thoracotomy. Histopathologically, the tumor consisted of collagen fibers and small amount of fibroblast. Localized fibrous mesothelioma was recognized as benign with good prognosis. However, a few cases showing recurrence after resection were reported among them. So it was considered that this patient should be followed up carefully.

Female↗
PubMed1996

[A case of catamenial pneumothorax with elevated level of serum CA 125].

A 40-year old woman had experienced repeated spontaneous pneumothorax on the right side at the beginning of each menstrual period for one year. The level of serum CA125 was high at 60 ng/ml. Right thoracotomy revealed the presence of multiple darkly-pigmented spots and several pinhole like perforations near the central tendon of the diaphragm. The partial resection of the diaphragm was done, endometrial tissues were detected histologically. Tha patient has been asymptomatic after operation and the level of serum CA125 is normal.

Adult↗
PubMed1986

[Studies on prolactin secreting capacity in the ovulatory infertile patients with transient hyperprolactinemia].

The changes in serum prolactin levels during the menstrual cycle have not been clarified yet. The present study was conducted to investigate whether the changes in serum prolactin levels during the menstrual cycle exist in ovulatory infertile patients having high prolactin release due to TRH administration described below (transient hyperprolactinemia) and control cases. Serum prolactin levels in both groups were less than 25 ng/ml at daytime. In the patients with transient hyperprolactinemia, serum prolactin levels showed more than 150 ng/ml at 30 min. after the administration of 500 micrograms of TRH, and those were less than 150 ng/ml in the normal control group. The daily changes of serum FSH, LH, prolactin, estradiol and progesterone levels were determined by radioimmunoassay in 6 cases of transient hyperprolactinemia and 5 controls which showed normal ovulatory cycles in the patterns of the BBT charts and other hormones. An estrogen feedback test was also carried out at the mid-luteal phase in 9 cases of transient hyperprolactinemia and the controls to determine serum levels of FSH, LH, prolactin and estradiol. In the patients with transient hyperprolactinemia, 5 mg of bromocriptine was administered every day for more than 30 days, and the effects of bromocriptine on the changes in serum gonadotropin levels by the estrogen feedback test were also analysed. Serum prolactin levels in the follicular, ovulatory and mid-luteal phases increased significantly in the patients with transient hyperprolactinemia, compared to the controls (p less than 0.005). The pattern of serum prolactin levels in the patients with transient hyperprolactinemia was almost synchronized with that of serum estradiol levels. There was also a significant correlation (r = 0.5782, p less than 0.005) between the prolactin and estradiol levels in the serum of the patients. The obvious change was not noted in serum prolactin levels during the menstrual cycle of the controls. No significant change in other hormones was observed during the cycle between these two groups. After the administration of estradiol benzoate (100 micrograms/kg), serum estradiol levels increased markedly, serum prolactin levels increased with the similar change in serum estradiol levels, and serum prolactin levels in the patients with transient hyperprolactinemia were significantly higher compared to those of the controls (p less than 0.01 approximately 0.005). The responses of serum gonadotropin levels by the administration of estradiol benzoate had good positive and negative feedback effects in the patients with transient hyperprolactinemia as well as those of the control group.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1986

[Effects of transient or occult hyperprolactinemia on luteal function].

It is well known that the luteal function in the patients with hyperprolactinemia is much suppressed by high level of serum prolactin. Present study was performed to investigate whether the luteal function in the patients with transient or occulted hyperprolactinemia was affected by the transient increase of serum prolactin level. The circadian changes of serum FSH, LH, prolactin, estrone, estradiol and progesterone levels were examined in seven cases of the transient or occulted hyperprolactinemia whose BBT charts showed biphasic patterns. Serum prolactin levels of these patients were less than 25 ng/ml at daytime and more than 150 ng/ml at 30 minutes after the administration of 500 micrograms of TRH. Blood samplings were taken every two hours through an intravenous indwelling catheter without any disturbances. All of the patients had their breakfast at 7 to 8, lunch at 11 to 12 and dinner at 17 to 18 o'clock and slept from 22 until 6 in the next morning. Serum FSH, LH, prolactin, estrone, estradiol and progesterone levels were determined by RIA and the circadian changes of these hormones were analysed. Then, 5 mg of bromocriptine was administered every day to these patients for more than 30 days and the duration of the luteal phase and the mid-luteal serum estradiol and progesterone levels for the indicators of the luteal function were examined before and after the administration of bromocriptine. The circadian changes of serum prolactin levels in the patients showed significant increase during both daytime and night compared to those of the control (p less than 0.005, p less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

[Comprehensive approach to the clinical study of the administration of dehydroepiandrosterone-sulfate (DHA-S) during the induction of labor].

Effects of Dehydroepiandrosterone-Sulfate (DHA-S) administration during the induction of labor were analysed comprehensively in 116 cases of primipara without any complications. In all of the patients delivery was induced by means of intravenous drip infusion of oxytocin. DHA-S was given as follows; Group A: no administration of DHA-S, Group B: intravenous drip infusion of 600 mg of DHA-S, Group C: intravenous injection of 200 mg of DHA-S every two hours (max, five times). The duration of the first and second stages of labor was reduced significantly in Group C compared to that of Group A (p less than 0.02). Serum DHA-S and estradiol levels in the patients in Groups B and C were significantly higher than those in Group A during the induction of the labor (p less than 0.05-0.005). The secretion of maternal milk was suppressed transiently by the administration of DHA-S (p less than 0.05-0.005), and there was a significant negative correlation between the total amount of maternal milk secretion and the total dose of DHA-S (r = -0.6320, p less than 0.005). Maternal serum prolactin levels did not change significantly following the administration of DHA-S, but estradiol increased significantly following the administration of DHA-S until 48 hours after delivery. These facts suggested that the intravenous injection of 200mg of DHA-S every two hours was effective in assisting the induction of labor, and the transient suppression of maternal milk secretion due to the administration of DHA-S might be caused by the high level of maternal serum estradiol which was converted from DHA-S in the placenta.

Adult↗
PubMed1985

[A study on pathogenesis and treatment of normoprolactinemic galactorrhea syndrome].

To investigate the pathogenesis of the normoprolactinemic galactorrhea syndrome, the response of prolactin secretion to TRH administration and the circadian profile of serum prolactin levels were examined in 13 women with galactorrhea whose resting levels of serum prolactin were lower than 25 ng/ml. Bromocriptine (5mg/day) was administered for 30 days and the mid-luteal serum estradiol and progesterone levels, as indicators of luteal function, were also measured before and after the administration. The basal levels of serum prolactin in these patients were significantly higher than those of the control (p less than 0.05), and the response of prolactin secretion also increased significantly at 30, 60, 90 and 120 min. after TRH administration compared to those of the control (p less than 0.005). The circadian profile of serum prolactin showed significantly higher levels from 22 to 8 o'clock compared to the control (p less than 0.05 approximately 0.005). And serum prolactin levels of these patients were higher than 25 ng/ml during the nocturnal period. When bromocriptine was administered, serum prolactin levels of these patients dropped conspicuously, and the nocturnal surges of prolactin also suppressed. Serum estradiol and progesterone levels in the mid-luteal phase normalized apparently due to the administration of bromocriptine (p less than 0.005, p less than 0.005), and galactorrhea also disappeared. These facts suggested that the normoprolactinemic galactorrhea syndrome might be caused by transient occulted hyperprolactinemia, and the treatment with bromocriptine was useful not only in suppressing galactorrhea but also in improving the luteal function in these patients.

Bromocriptine↗
PubMedDate not supplied

An artificial gill system for oxygen uptake from water using perfluorooctylbromide.

If the oxygen dissolved in seawater could be used for breathing, human beings could spend more time under water, greatly increasing their mobility. As yet, however, sufficient oxygen to enable us to live in the sea for long periods is not available. An artificial gill system has been developed for oxygen uptake from water to deoxygenated air using perfluorooctylbromide (PFOB), which has high oxygen solubility. It was found that oxygen was transferred rapidly from water to PFOB when water flowed outside the hollow fibers and PFOB flowed inside. Oxygen transfer through the membrane from PFOB to air was found to be the rate determining step. Use of PFOB gave a stable supply of oxygen from water to deoxygenated air over long periods. It was found that PFOB acts as a storage medium for oxygen.

Air↗