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Biomedical subjects

K Namikawa

Publications and source records attributed to K Namikawa.

At least 55 records · Page 3Linked to original sources
PubMed1993

[Changes in myocardial metallothionein on isoproterenol-induced myocardial injury].

The amounts of myocardial metallothionein (MT) and heavy metal (Zn, Cu) levels during the early stage of the experimental myocardial infarction model induced by isoproterenol (Isp) administration were measured by an atomic absorption spectrophotometry. MT was measured by the Cd-hem method. Myocardial infarction was induced by the administration of 75 mg/kg i.p. of Isp to rats weighing 270 +/- 10 g. Thirty minutes after Isp injection, Zn and Cu levels began to decrease and 12 h later, reached the minimal values compared with the control value. The level of MT began to increase 3 h after the Isp injection and reached the maximal value at 12 h, although MT remained undetectable in the control myocardial tissue by the Cd-hem method. MT levels in the liver increased and total Zn and Cu were elevated compared with the control value 12 h after Isp administration. These results suggest that MT is produced in the myocardium after Isp administration, and that the roles of MT in the heart and the liver are different. It was thought that a rise in MT was induced for the protection of the myocardial cells to injury.

Animals↗
PubMed1992

[Studies on early stage changes of peroxide lipid in isoproterenol-induced myocardial injury].

The amount of peroxide lipid in vivo in the early stage of the experimental model of myocardial infarction in a rat induced by the administration of isoproterenol (Isp) was measured as the value of malonic dialdehyde (MDA). The model of myocardial infarction was made by giving 75 mg/kg of Isp to the rat weighing 270 +/- 10 g. After the administration of Isp, the amounts of lipid in the serum and in the myocardial tissue were measured, and a blood chemistry test (glutamic oxaloacetic dehydrogenase, glutamic pyruvic transaminase, lactate dehydrogenase, free fatty acid, creatine kinase) was simultaneously carried out on the serum. The value of the amount of peroxide lipid in the serum began to elevate 3 h after the administration of Isp and reached a maximum value at 6 h. The value of the amount of peroxide lipid in the tissue began to elevate 30 min after the administration and reached a maximum at 3 h. Each blood chemistry disclosed the elevation 30 min after the administration. As mentioned above, the production of peroxide lipid in vivo on the myocardial disorder in the early stage after the administration of Isp and the biochemical changes showed a significant correlation. From these results it is suggested that the myocardial disorder induced by the administration of Isp has already developed at 30 min after the administration.

Animals↗
PubMed1990

[Human respiratory tract infection by Pasteurella multocida subsp. multocida presumably derived from the cat].

Pasteurella multocida is a Gram-negative short rod-shaped bacteria that has been recognized as a pathogen of hemorrhagic septicemia and fowl cholera in the veterinary medicine. Infections by this microorganism as seen in the foreign literature vary widely from local infections due to bites and scratches by animals to general infections such as infections of the respiratory tract, sepsis, and meningitis. In Japan, reported cases of P. multocida infections are predominantly local infections, followed by respiratory infection. Recently, death of diabetic patients due to septicemia by this pathogen has also been reported. In this study, we experienced a case of respiratory tract infection in which the pathogen P. multocida subsp. multocida was suggested to have been transmitted from a pet cat by the agreement of the serotype of the bacterial isolates between the patient and the cat. This case was evaluated from the zoonotic viewpoint. The patient was a 68-year-old male who had been followed up since 1982 with a diagnosis of bronchiectasis. After his referral to our hospital, P. multocida subsp. multocida was isolated from his bloody sputum and, then, from the cat kept by the patient. The tow isolates were identical in terms of the biochemical properties, drug susceptibility profile, and serotype (-:1), and the derivation of P. multocida subsp. multocida infection from cat was established for the first time in this report. The incidence of P. multocida infections is increasing in Japan, and particular attention is considered to be needed about these conditions as zoonoses as indicated in "Preventive Measures against Zoonoses Derived from Pet Animals (Dog, Cat)", an official communication from the Ministry of Health and Welfare to related institutions in 1989. Also, to check whether the patient keeps any pet at the clinical inquiry is a practice of bacteriological importance in all fields of medicine.

Aged↗
PubMed1989

Retinobenzoic acids. 3. Structure-activity relationships of retinoidal azobenzene-4-carboxylic acids and stilbene-4-carboxylic acids.

Alkyl-substituted azobenzene-4-carboxylic acids are potent differentiation inducers of human promyelocytic leukemia cell line HL-60 to mature granulocytes. Their structure-activity relationships are very similar to those of other retinoidal benzoic acids which are generally represented by 4 and named retinobenzoic acids. The structure-activity relationships of azobenzenecarboxylic acids can also be applied to the known retinoid TTNPB (3). Thus, (E)-4-[2-(3,4-diisopropylphenyl)-1-propenyl]benzoic acid (St30 (28] and (E)-4-[2-(3-tert-butylphenyl)ethenyl]benzoic acid (St40 (29], the acyclic alkyl analogues of TTNPB, are nearly as active as retinoic acid. Among the oxidatively derived compounds (Az90, Ep series and Ox series) of azobenzene- or stilbenecarboxylic acids, Az90 (71) and Ep80 (61) have strong activities. However, all the bishydroxylated derivatives of TTNPB are inactive, while a diketo analogue Ox580 (69) has only weak potency. The activities of conformationally restricted compounds of TTNPB offer some information on the stereochemistry of the active form of these retinoidal compounds.

Benzoates↗
PubMed1985

[Circulating negative inotropic substance produced by the lung, affected by prostaglandin and thromboxane].

The Lung is capable of the synthesis and the release of prostaglandins responded to a number of pathophysiological stimuli, which may impair myocardial performance. Present study was undertaken to determine the release of circulating negative inotropic substance(s) from the lung and whether or not blockage of prostanoid synthesis, or infusion of prostaglandin are related to the production of this substance(s). Sixteen isolated left lower lobes were divided into 3 groups: (1) untreated, isolated blood-perfused lungs (n = 5), (2) prostaglandin I2, 1 microgram/min, continuously added to the perfusate (n = 6), and (3) five lobes pretreated with ibuprofen (12.5 mg/kg) in addition to 1 microgram/min prostaglandin I2. Perfusion of an isolated lobe with heparinized whole blood caused thrombocytopenia. The plasma 4 hours after perfusion led to the generation of a humoral agent(s) that reduced developed tension (Tpd) of a papillary muscle (p less than 0.05), and Ca++ -and Mg++-ATPase of sarcoplasmic reticulum (SR) (p less than 0.01). With prostaglandin I2, thromboxane B2 rose from 0.076 to 0.362 ng/ml at a level higher than control (p less than 0.05). The plasma significantly lowered SR-ATPase and myofibril-Mg++-ATPase activities and further reduced papillary muscle Tpd. By pretreatment with ibuprofen, adverse prostaglandin I2 effects were eliminated. The observation suggests that the lung produces prostaglandin related negative inotropic substance(s) that may reduced contractility, affected by energy availability.

Adenosine Triphosphatases↗