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Biomedical subjects

K Ohtani

Publications and source records attributed to K Ohtani.

240 records · Page 14Linked to original sources
PubMed1978

[Talampicillin hydrochloride: Comparison with amoxicillin and ampicillin in the antibacterial activity and pharmacokinetics (author's transl)].

The antibacterial activities, absorption and excretion of talampicillin hydrochloride were compared with those of amoxicillin and ampicillin. Talampicillin hydrochloride showed a broad-spectrum antibacterial activity against Gram-positive and Gram-negative bacteria as seen in amoxicillin and ampicillin. The antibacterial activities of talampicillin hydrochloride, amoxicillin and ampicillin were quite similar. In experimental murine infection with Staphylococcus aureus, protective effect of talampicillin hydrochloride was superior to ampicillin. For Escherichia coli infection, protective effect of talampicillin hydrochloride was similar to that of amoxicillin, while ampicillin was less active than both talampicillin hydrochloride and amoxicillin. The absorption and excretion of 250 mg equivalent doses of talampicillin hydrochloride, amoxicillin and ampicillin were compared in nine fasting healthy volunteers after oral administration of these antibiotics in randomized triple crossover study. In order to calculate the pharmacokinetic parameters, plasma levels were analyzed using an one-compartment open model, as well as area under the plasma concentration curve (AUC) and urinary excretion. Maximum plasma levels calculated were 2.8 times higher for talampicillin hydrochloride and 1.45 times higher for amoxicillin than for ampicillin. AUC was greater for talampicillin hydrochloride than for amoxicillin and lowest for ampicillin. Urinary excretion of talampicillin hydrochloride as penicillin determined in biological assay was comparable to that of amoxicillin and 1.55 times higher than that of ampicillin. Penicillins can be metabolized to penicilloic acids in the body. After taking into account the penicilloic acid contents in urine, total excretion in urine was 61% for talampicillin hydrochloride, 67% for amoxicillin and 42% for ampicillin during 6 hours after dosing. The absorption of the drugs was evaluated according to the plasma levels, the area under plasma concentration curve and the percentage of excretion in urine. The results obtained showed that talampicillin hydrochloride was well absorbed from the gastro-intestinal tract.

Adult↗
PubMed1975

[Clinical application of synthetic LH-RH for anovular women unresponsive to clomiphene therapy (author's transl)].

UNLABELLED: The purpose of this study is to clarify the significance of synthetic LH-RH (RH) as a therapeutic agent in the treatment of anovular women who fail to respond to clomiphene therapy. METHODS: Fifteen women with hypofunction of the hypothalamus-pituitary system who were given the RH-test were divided into two groups according to the maximum increased level of LH shown by each. Group I consisting of 7 women who showed increased levels of over 20miu/ml received a combination of clomid+estrogen+RH(C.E.R). Blood levels of LH, FSH and estradiol were measured in each. Group II consisting of 8 women who showed maximum levels of LH below 20 miu/ml received RH intramuscularly, 100 mug per day for 20 to 30 days (referred to as RH treatment). The RH-test was performed in this group before treatment, and 1, 7 and 21 days after treatment. Blood levels of estradiol were also determined before, during and after treatment. RESULTS: 1) Ovulation occurred in 5 of the 7 women in group 1 and 3 became pregnant. The LH surge was prolonged and hormonal secretion increased with administration of C.E.R.. The normal estrogen surge and gonadotropin surge occurring in the ovulatory cycle were thus produced artificially. Since administration of clomiphene alone tends to produce insufficiency of cervical mucus secretion because of its anti-estrogen effect, the addition of estrogen to the combination of C.E.R. probably increases the cervical secretion of mucus and enhances the probability of impregnation. 2) Compared to pretreatment levels, RH treatment clearly increased the pituitary secretion of LH and FSH. Even 3 weeks after RH treatment, the pituitary secretion of gonadotropin was definitely higher than before treatment. Fluctuations in blood levels of estradiol during and after treatment were not significantly different than before treatment. These observations would suggest that prolonged administration of RH enhances the gonadotropic function of the pituitary, not only in the secretion of the hormones but also in the synthesis of gonadotropin. Judging from the insignificant effect on the blood level of estradiol, it would appear that RH itself possesses the ability to produce gonadotropin.

Anovulation↗
PubMedDate not supplied

Electric-field control of ferromagnetism.

It is often assumed that it is not possible to alter the properties of magnetic materials once they have been prepared and put into use. For example, although magnetic materials are used in information technology to store trillions of bits (in the form of magnetization directions established by applying external magnetic fields), the properties of the magnetic medium itself remain unchanged on magnetization reversal. The ability to externally control the properties of magnetic materials would be highly desirable from fundamental and technological viewpoints, particularly in view of recent developments in magnetoelectronics and spintronics. In semiconductors, the conductivity can be varied by applying an electric field, but the electrical manipulation of magnetism has proved elusive. Here we demonstrate electric-field control of ferromagnetism in a thin-film semiconducting alloy, using an insulating-gate field-effect transistor structure. By applying electric fields, we are able to vary isothermally and reversibly the transition temperature of hole-induced ferromagnetism.

Journal Article↗
PubMedDate not supplied

A sensitive enzyme-linked immunosorbent assay for detection of T-2 toxin with monoclonal antibodies.

Six monoclonal antibodies (mAbs, T-2.1, 2, 3, 4, 5, 6) which react with a trichothecene mycotoxin, T-2 toxin (T-2), were prepared. All antibodies specifically reacted with T-2 but less (0.5% of T-2) with the metabolites such as HT-2 toxin and 3'-hydroxy-T-2 toxin. Significant but less than 0.02% cross-reactivity was observed with T-2 triol, 3'-hydroxy-HT-2 toxin and neosolaniol. No significant reaction with other trichothecenes such as deoxynivalenol, nivalenol, fusarenon-X, crotocin, or roridin A was observed. The least detectable amount of T-2 with the best mAb T-2.1 was 2.5 pg T-2 per assay. This specific and highly sensitive assay for T-2 was applied for the quantitation of T-2 in wheat flour spiked with mycotoxin, with combination of a simple extraction procedure.

Animals↗
PubMedDate not supplied

Is there any benefit of preservation of the spleen in distal pancreatectomy?

For a pancreatic body or tail tumor, distal pancreatectomy with splenectomy (DPS) is a standard operation. Spleen-preserving distal pancreatectomy (SPDP) was introduced in order to preserve the organ and thus provide the patient with a better quality of life. Clinical data were compared between 38 Japanese patients with DPS and 9 with SPDP for benign tumors or tumor-like lesions at the body or tail of the pancreas at preoperative, early postoperative (< 3 months after operation), and late postoperative periods (>6 months after operation). The preoperative findings were not different between the two groups except for the significantly higher serum amylase levels in the SPDP group. Operation time, operative blood loss, and length of postoperative hospital stay were not different between the two groups. Pancreatic fistula occurred in 3 (8%) of the 38 patients in the DPS group and in 1 (11%) of the 9 patients in the SPDP group, abdominal abscess in 5 (13%) of the 38 patients in the DPS group and none (0%) in the 9 patients in the SPDP group. At short-term, clinical findings were not different between the two groups except for a significantly greater platelet count in the DPS group than in the SPDP group (46.8 x 10(4)/microl versus 29.6 x 10(4)/microl, P = 0.0081). At long-term after the operation, clinical findings, including the platelet count, were not different between the two groups. Computed tomography revealed a pseudocyst in 9 (53%) of 17 patients examined in the DPS group and in 3 (75%) of 4 patients examined in the SPDP group at short-term after operation. All patients with pseudocysts were asymptomatic. Two asymptomatic patients (one in the DPS group and one in the SPDP group) first developed a pseudocyst at long-term after the operation. The alteration of glucose tolerance was similar between the two groups. Postoperative pancreatic exocrine function (the N-benzol-L-tyrosyl-p-aminobenzoic acid test) was not different between the two groups. These data suggest that SPDP with preservation of the splenic vessels can be satisfactorily performed without elongating operative time and postoperative hospital stay or increasing risk of postoperative complications, with the exception of increased platelet count in the DPS group at short-term after the operation. Thus, SPDP is worth considering as one of the options for the treatment of benign lesions of the body or tail of the pancreas.

Adult↗