Search PubMed⌕ Search

Biomedical subjects

H Kawabe

Publications and source records attributed to H Kawabe.

At least 73 records · Page 4Linked to original sources

Determination of beta-lactam antibiotics in water by fluorescence quenching of mercurochrome, and application for simple investigation of potency.

The fluorescence quenching reaction between fluorescein mercury or halogeno-fluorescein mercury compounds (fl. Hg, 2,7- or 2,4-dichloro-fl.Hg, 3',4',5',6'-tetrachloro-fl.Hg, mercurochrome) and beta-lactam antibiotics (ampicillin (AB-PC) and cephalexin (CEX] was investigated, and mercurochrome was selected for the detection of beta-lactam antibiotics; the detection limit was about 0.8 micrograms/ml. A fluorimetric assay of beta-lactam antibiotics was established by measuring the fluorescence of mercurochrome and mercurochrome-beta-lactam antibiotics solutions in weakly basic media to determine the degree of fluorescence quenching. The maximum emission wavelength of mercurochrome solution was at 544 nm with excitation at 470 nm. The calibration graphs were linear over the ranges of about 0-6 micrograms/ml beta-lactam antibiotics penicillins (AB-PC, penicillin G, sulbenicillin, amoxicillin, cyclacillin, oxacillin, hetacillin and piperacillin) and cepham antibiotics (CEX, cefazolin, cephaloglycin, cephaloridine and cefpyramide), and the relative standard deviation was 2.7% for 1.4 micrograms/ml of AB-PC (n = 5). This fluorescence quenching reaction between mercurochrome and beta-lactam antibiotics was applied in a survey of decomposition and remaining potency of beta-lactam antibiotics.

Anti-Bacterial Agents↗

[A case report of leiomyosarcoma of the rectum].

A case of leiomyosarcoma of the rectum and a review of the relevant Japanese literature is reported. A 33-year-old man, suspected of having a rectal tumor was admitted to out hospital for though examination. The tumor was located at the anterior wall of the rectum behind the prostatic gland. A preoperative perineal biopsy was done and the pathological diameters was a leiomyosarcoma. The abdominoperineal resection was performed but the nerve was able to be preserved. The postoperative quality of life has been good. The difficulties in arriving at a histological differentiation of a simple tumors of the rectum from a malignant smooth muscle tumor of the rectum is discussed.

Adult↗

Differential calcium effects on prostaglandin D2 generation and histamine release from isolated rat peritoneal mast cells.

We examined the role of Ca2+ mobilization in prostaglandin (PG) D2 generation and histamine release induced by A23187 from rat peritoneal mast cells. Both PGD2 generation and histamine release accompanied with 45Ca uptake were observed above 0.1 microM A23187. Although an increase of PGD2 generation was not exactly correlated with that of Ca2+ uptake, histamine release occurred in proportion to Ca2+ uptake. In contrast to PGD2 generation, below 0.1 microM A23187, about 20% of the total histamine was released without Ca2+ uptake and this response was inhibited by 10 microM 8-(N,N-diethylamino)-octyl-3,4,5-trimethoxybenzoate hydrochloride (TMB-8), which is an intracellular Ca2+ antagonist. However, TMB-8 had no effect on PGD2 generation. These results suggest that Ca2+ dependency of histamine release is clearly different from that of PGD2 generation, and that histamine release is induced by not only Ca2+ uptake but also intracellular Ca2+ mobilization.

Animals↗

Oxatomide inhibits the release of bronchoconstrictor arachidonic acid metabolites (iLTC4 and PGD2) from rat mast cells and guinea-pig lung.

The effect of oxatomide, an orally active antiallergic drug, on immunoreactive LTC4 (iLTC4) production has been studied in rat peritoneal exudate cells (PEC) and guinea-pig lung fragments using the calcium ionophore A23187 and specific antigen in vitro. Oxatomide (10(-5) M) inhibited iLTC4 release by 70% with A23187 from rat PEC, and by 48% with antigen from guinea-pig lung. Oxatomide is supposed to affect the biosynthesis pathway of leukotrienes, because oxatomide inhibits 5-lipoxygenase from guinea-pig peritoneal leukocytes with an IC50 17 microM. Oxatomide also depressed the release of PGD2 from rat peritoneal mast cells stimulated by A23187 (IC50 4.2 microM). The effects of oxatomide on iLTC4 and PGD2 release were more potent than other antiallergic drugs (DSCG, ketotifen, tranilast).

Animals↗

Determination of 9 alpha, 11 beta-prostaglandin F2 by stereospecific antibody in various rat tissues.

In view of the recent finding that prostaglandin D2 is stereospecifically converted to 9 alpha, 11 beta-prostaglandin F2, an isomer of prostaglandin F2 alpha, a highly specific and sensitive radioimmunoassay for 9 alpha, 11 beta-prostaglandin F2 was developed and applied to determine the content of this prostaglandin in various rat tissues. Antisera against 9 alpha, 11 beta-prostaglandin F2 were raised in rabbits immunized with the bovine serum albumin conjugate, and [3H]9 alpha, 11 beta-prostaglandin F2 was enzymatically prepared from [3H]prostaglandin D2. The assay detected 9 alpha, 11 beta-prostaglandin F2 over the range of 20 pg to 1 ng, and the antiserum showed less than 0.04% cross-reaction with prostaglandin F2 alpha, prostaglandin F2 beta and 9 beta, 11 beta-prostaglandin F2. To avoid postmortem changes, tissues were frozen in liquid nitrogen immediately after removal. The basal level of 9 alpha, 11 beta-prostaglandin F2 was hardly detectable in various tissues of the rat examined, including spleen, lung, liver and brain; although it was found to be 0.31 +/- 0.06 ng/g wet weight in the small intestine. During convulsion induced by pentylenetetrazole, enormous amounts of prostaglandin D2 (ca. 180 ng/g wet weight) and prostaglandin F2 alpha (ca. 70 ng/g) were produced in the brain; however, 9 alpha, 11 beta-prostaglandin F2 was detected neither there nor in the blood. This result demonstrates that the conversion to 9 alpha, 11 beta-prostaglandin F2 is a minor pathway, if one at all, of prostaglandin D2 metabolism in the rat brain.

Animals↗

Characterization of receptors for angiotensin-induced drinking and blood pressure responses in conscious rats using angiotensin analogs extended at the N-terminal.

Angiotensin II analogs with N-terminal extensions were synthesized to examine their effects on the brain and vascular angiotensin II (Ang II) receptors of the rat. Ang II, Crinia-Ang II, Thr.Ala.Gly-Ang II and Val. Ser.Leu.Thr.Ala.Gly-Ang II were all found to elicit drinking and raise blood pressure when given into the cerebrospinal fluid (CSF), and elevate blood pressure when given intravenously. When given intracerebroventricularly, the order of potency of the peptides in eliciting blood pressure and drinking responses was: Ang II (100%) = Crinia-Ang II (100%) greater than Thr.Ala.Gly-Ang II (10% blood pressure, 15% drinking) greater than Val.Ser.Leu.Thr.Ala.Gly-Ang II (5%). The order of pressor potency did not change when the Ang II analogs were given intravenously, but compared with the central effects, there was a marked difference in the relative potencies of the peptides. The potencies were: Ang II (100%) greater than Crinia-Ang II (80%) greater than Thr.Ala.Gly-Ang II (60%) greater than Val.Ser.Leu.Thr.Ala.Gly-Ang II (20%). Blood pressure and drinking responses produced by all of these peptides were markedly attenuated by the Ang II receptor antagonist, [Sar1,Thr8] Ang II. These findings indicate a difference in the Ang II receptors present in the brain and the periphery. However, no differences were noted between the central Ang II receptors mediating the pressor responses and the central Ang II receptors stimulating drinking behavior.

Angiotensins↗

[Pancreatic acinar cell carcinoma curatively resected by pancreaticoduodenectomy].

The incidence of acinar cell carcinoma among malignant pancreatic tumors is about 1%, and the prognosis is reported to be poor. We resected an acinar cell carcinoma that had arisen on the pancreatic head by pancreaticoduodenectomy in December 1983. This tumor occupied the pancreatic head, and it measured 10 X 9.5 X 9.5 cm. The microscopic findings showed that the tumor cell was well-differentiated and acinar formation was uniform. The growth of the tumor was expansive, and the lesion was clearly capsulated by fibrous tissue. There was no lymph node metastasis, so the curative operation was performed by the enbloc resection of the tumor. Zymogen granules in the tumor cells were confirmed by electron microscopy. Consequently, we concluded that the origin of the tumor was acinar cells.

Carcinoma↗

Metoclopramide in the diagnosis of pheochromocytoma.

Cardiovascular and plasma catecholamine responses to metoclopramide (MCP), a dopamine antagonist, were examined in 5 patients with pheochromocytoma, 12 patients with essential hypertension (EHT) and 9 normotensive (NT) subjects who displayed symptoms suggestive of pheochromocytoma on a constant daily intake of 100 mEq sodium and 80 mEq potassium. Significant pressor responses to intravenous doses of 5 mg of MCP, which produced no serious pressor episodes and no other undesirable side effects, were found only in the patients with pheochromocytoma, in contrast to the subjects with EHT and NT who tended to display slight depressor responses. After curative surgery for pheochromocytoma, the MCP-induced pressor effects returned to normal. Furthermore, the enhanced pressor effects of MCP in the patients with pheochromocytoma were associated with increased plasma norepinephrine (NE) concentrations. However, the plasma epinephrine (E) concentrations remained unchanged after the MCP injection. Thus, this dose of MCP appears to be a more suitable vasopressor provocative agent in the pharmacological diagnosis of pheochromocytoma compared to currently used agents.

Adolescent↗

Mn(III)-containing acid phosphatase. Properties of Fe(III)-substituted enzyme and function of Mn(III) and Fe(III) in plant and mammalian acid phosphatases.

The function of Mn(III) in plant acid phosphatase has been investigated by a metal-substitution study, and some properties of the Fe(III)-substituted enzyme were compared with those of the native Mn(III) enzyme and mammalian Fe(III)-containing acid phosphatases. 19F nuclear magnetic resonance (NMR) and proton relaxation rate measurements showed that inhibitors such as F- and nitrilotriacetic acid interact with paramagnetic Mn(III) active site. The 31P-NMR signal of the enzyme-phosphate complex was also broadened by the paramagnetic effect of Mn(III). In the metal-substitution experiments of the Mn(III)-acid phosphatase with Fe(III), Zn(II) and Cu(II), only the iron gave satisfactory substitution. The Fe(III)-substituted plant acid phosphatase exhibited an absorption maximum at 525 nm (epsilon = 3000), typical high-spin ferric ESR signal at g = 4.39, and lower pH optimum (pH 4.8) than the native Mn(III)-enzyme (pH 5.8). The phosphatase activity of the Fe(III)-substituted enzyme was reduced to about 53% of that of the native enzyme. The substrate specificities of both metallophosphatases were remarkably similar, but different from that of the Fe(III)-containing uteroferrin. The present results indicate that Mn(III) and Fe(III) in the acid phosphatase play an important role on effective binding of phosphate and acceleration of hydrolysis of phosphomonoesters at pH 4-6.

Acid Phosphatase↗