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Biomedical subjects

A Nitta

Publications and source records attributed to A Nitta.

At least 91 records · Page 5Linked to original sources
PubMed1992

Rapid detection of the mecA gene in methicillin-resistant staphylococci by enzymatic detection of polymerase chain reaction products.

In order to identify methicillin-resistant staphylococci from clinical sources with ease and reliability, enzymatic detection of polymerase chain reaction (ED-PCR) was applied. ED-PCR is based on the capture of amplified products via biotin-streptavidin affinity and the detection of an incorporated hapten in amplified products with an enzyme-linked antibody. In order to identify methicillin-resistant staphylococci of all species, a 150-bp fragment of the mecA gene was targeted for ED-PCR. After PCR was performed with a pair of biotin and dinitrophenol 5'-labeled primers, the reaction mixture was applied to a microtiter well precoated with streptavidin. Thereafter, bound PCR products were detected colorimetrically with alkaline phosphatase-conjugated anti-dinitrophenol antibody. The extraction of DNA from staphylococcal cells for PCR was simplified so that it could be performed within one tube. The total assay, including PCR, took less than 3 h. The sensitivity of mecA gene detection ranged from greater than 5 x 10(2) CFU per tube for Staphylococcus aureus to greater than 5 x 10(3) CFU per tube for Staphylococcus epidermidis. Genotyping results obtained by ED-PCR of 161 tested strains from the colonies (97 strains of S. aureus and 64 strains of coagulase-negative staphylococci) were compared with the phenotypic susceptibilities of the strains to oxacillin. The results of ED-PCR showed excellent agreement with the MICs of oxacillin with very few exceptions; only one strain of S. aureus and two strains of coagulase-negative staphylococci were found to possess the mecA gene, which was discrepant with their phenotypes. Fifty-five blood culture samples were also tested by ED-PCR. For staphylococcal isolates in 33 of the cultures, oxacillin MICs were >4 microgram/ml; 31 of the 33 staphylococcal isolates were determined by ED-PCR to be mecA gene positive. These results suggest that ED-PCR can be used with reasonable confidence in the clinical microbiological laboratory.

Alkaline Phosphatase↗
PubMed1992

[Clinicopathological and immunohistochemical studies on carcinoma of the papilla of Vater].

The non-invasive adenomatous component (nac) was observed in 44% of 32 resected specimens of carcinoma of the papilla of Vater. Incidence of the "nac" positive carcinoma declined with cancer staging, but there was no significant relationship between the "nac" and tumor size. The "nac" positive rates in "tumor forming", "ulcerating" and "mixed" types were 65, 0 and 38%, respectively. The "nac" negative carcinoma metastasized more frequently to the lymph nodes, duodenum, pancreas and veins. The five year survival rates of the patients with the "nac" positive and negative carcinoma were 78 and 22%, respectively. Immunohistochemically, the "nac" positive carcinoma mostly showed partial distribution of CA19-9, while the "nac" negative carcinoma, carcinoma of the pancreas and bile duct mostly showed diffuse distribution. The intact mucosa of the common channel and orifice of the papilla almost showed partial distribution, and duodenal mucosa showed negative distribution. The pancreatic and bile duct almost indicated diffuse distribution. The "nac" may be precancerous condition and the "nac" positive carcinoma may arise from the common channel or the orifice of the papilla or the duodenum. But the "nac" negative carcinoma may belong primarily to carcinoma of the pancreas and bile duct as de-novo carcinoma.

Adenoma↗
PubMed1992

[Blood flow in the optic nervehead following intravenous administration of calcium antagonist].

The authors quantitated the blood flow of the optic nervehead after intravenous administration of calcium antagonist. The hydrogen clearance method was used to measure the blood flow after placing an electrode sensor in the optic nervehead of 9 eyes of 5 Macaca fuscata monkeys, under general anesthesia by intravenous pentobarbital sodium. 5 micrograms/kg of nicardipine, a calcium antagonist, was rapidly injected into the femoral vein. Measurement of blood flow in the optic nervehead was started 5 minutes after injection until 90 minutes at intervals of 15 minutes. A dose of 2 micrograms/kg/min nicardipine was then administered intravenously for another 90 minutes. During the experiment, intraocular pressure was maintained at 15 mmHg under continuous monitoring of systemic blood pressure. The blood flow in the optic nervehead decreased to 83% 5 minutes after injection. It increased slowly and reached the initial value 50 minutes later. It reached 108% of the initial value 80 minutes after injection. During the additional infusion of nicardipine, the blood flow decreased slowly and reached 85% of the initial value. It is concluded that the blood flow in the optic nervehead changed depending on the method, quantity and duration after injection of intravenous calcium antagonist. The blood flow decreased immediately after administration. The main cause of this phenomenon was thought to be due to decrease of perfusion pressure secondary to decrease of systemic blood pressure.

Animals↗
PubMed1991

Structure-related inhibitory effect of quinolones on alkyl-xanthine elimination in rats.

To investigate the relationship between the chemical structures of quinolones, enoxacin (ENX) and its analogues, and their metabolic inhibitory effects on theophylline, a xanthine derivative closely related to theophylline, 1-methyl-3-propylxanthine (MPX), was used as a model of theophylline in rats. The disappearance of MPX from plasma was significantly delayed by treatment with ENX and analogue A (derivatives without substituent group at both 3'- and 5'- carbon atom in the piperazinyl ring): total body clearance of MPX was significantly decreased by approximately 50%. However, analogue A was converted into ENX in the rat body (about 14% of dose). Analogues B and C (derivatives with substituent group at 3'- or 5'-carbon atom in the piperazinyl ring) had little or no effect on MPX disposition. No significant change in the volume of distribution of MPX was observed after coadministration with these quinolones. The results of this study indicate that the substitutions on 3' and 5'-carbon atoms of piperazinyl ring at 7-position of the quinolone molecule may play important role in the inhibition of theophylline metabolism.

Animals↗
PubMed1991

Woodfordin D and oenothein A, trimeric hydrolyzable tannins of macro-ring structure with antitumor activity.

Two new antitumor trimeric hydrolyzable tannins, woodfordin D (5) and oenothein A (13), were isolated from the dried flowers of Woodfordia fruticosa, and their macrocyclic structures, which have a novel constituent unit (woodfordinoyl group) connecting the monomers, have been elucidated on the basis of spectral and chemical evidence. Oenothein A (13) was also isolated from the leaves of Oenothera biennis.

Antineoplastic Agents, Phytogenic↗
PubMed1990

Woodfordin C, a macro-ring hydrolyzable tannin dimer with antitumor activity, and accompanying dimers from Woodfordia fruticosa flowers.

Three new dimeric hydrolyzable tannins, woodfordins A, B and C, along with seven known hydrolyzable tannins, including oenothein B, a dimer exhibiting marked host-mediated antitumor activity, were isolated from an Indonesian crude drug, Sidowayah [dried flowers of Woodfordia fruticosa (L.) Kurz (Lythraceae)]. The structures of the new tannins were elucidated based on chemical and spectral evidence. Woodfordin C, having a macro-ring structure, was also found to exhibit a significant antitumor activity.

Animals↗
PubMed1989

Non-invasive adenomatous component in carcinoma of papilla of Vater: an immunohistochemical study of carbohydrate antigen, CA19-9.

Eleven patients with carcinoma of papilla of Vater accompanied by non-invasive adenomatous component (nac) had good prognosis after surgical resection. These carcinomas were associated with low serum CA19-9 levels seldom invaded or metastasized to the pancreas, duodenum, lymph node and vein. On the contrary, 12 patients whose carcinomas lacked in 'nac' had poor prognosis after resection. The 'nac' negative carcinomas invaded or metastasised more frequently to the pancreas, duodenum, lymph node and vein. A half of the 'nac' negative carcinoma showed high serum level of CA19-9. A significant different immunohistochemical pattern of CA19-9 was demonstrated between the 'nac' positive and negative carcinomas. The former showed partial, while the latter showed diffuse distribution pattern.

Adenoma↗
PubMed1989

[The blood flow in post-laminar optic nerve in monkeys was dependent on intraocular pressure level].

The effects of artificial elevation of intraocular pressure on the blood flow in the 1mm post-laminar portion of the optic nerve was evaluated in 9 monkeys (Macaca fuscata). The intraocular pressure of one eye was elevated while the fellow eye served as control. The intraocular pressure of the control was maintained at 15 mmHg. We used the hydrogen clearance method in quantitating the blood flow. Anesthesia was maintained with injection of pentobarbital sodium into the femoral vein. In each experiment, the intraocular pressure was raised from 15 mmHg to 30, 50 or 70 mmHg in a stepwise fashion. At the intraocular pressure level of 15 mmHg, the blood flow measured 120.0 +/- 19.4 ml/min/100g (mean +/- standard deviation). The blood flow decreased linearly along with the rise of intraocular pressure up to 70 mmHg. The blood flow at 70 mmHg was 37% of the initial value. At each level of raised intraocular pressure, the blood flow remained constant for at least 60 minutes. The decreased blood flow promptly returned to the initial level when the raised intraocular pressure was restored to the initial value of 15 mmHg. We concluded from the above findings that the blood flow in the immediate post-laminar portion of the optic nerve is dependent on the level of intraocular pressure up to 70 mmHg.

Animals↗
PubMed1988

[The serum and tissue concentrations of tegafur, 5-fluorouracil and uracil in patients with gastric and colorectal cancers after oral administration of UFT].

Fifteen patients with stomach cancer and colorectal cancer were orally administered 600 mg of UFT before operation and the concentration of tegafur, 5-fluorouracil (5-FU) and uracil in the tissues and serum were measured by chemical assay. The mean 5-FU levels in tumor and lymph node were higher than those in normal tissues and were maintained in tumor for long time. Uracil level in tumor tissue was higher than in normal tissue with or without administration of UFT. Positive correlation between the concentration of uracil and 5-FU in the colorectal tumor with the correlation coefficient of 0.87 (p less than 0.01) was obtained.

Administration, Oral↗