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Biomedical subjects

K Kogi

Publications and source records attributed to K Kogi.

At least 55 records · Page 3Linked to original sources
PubMed1982

[Hemodynamic effects of a transdermal formulation of isosorbide dinitrate and its pharmacokinetics in conscious dogs].

Transdermal application of isosorbide dinitrate (ISDN) in the form of a tape (ISDN-Tape) to conscious dogs, in a dose of 40 mg/dog, caused a slow decrease in pulse pressure. The maximum effect was obtained 12 hour after application. The pulse pressure was still under the initial level even after 48 hours of application. In contrast, a sustained-release tablet of ISDN (ISDN-SR-Tablet), given in a dose of 40 mg/dog, significantly decreased the pulse pressure of conscious dogs by reducing systolic pressure and slightly elevating diastolic pressure. The plasma concentrations of ISDN and its two metabolites, isosorbide 2-mononitrate (2-ISMN) and isosorbide 5-mononitrate (5-ISMN), were measured by gas chromatography after application of ISDN-Tape or ISDN-SR-Tablets. The time course pattern of the plasma concentration of ISDN after application of the both preparations ran quite parallel with their decreasing effect on the pulse pressure. After application of the ISDN-Tape, the plasma concentration of ISDN was maintained at a higher level than after the application of the ISDN-SR-Tablet. The maximum plasma concentrations of the two metabolites, however, were considerably lower in the case of the ISDN-Tape than in the case of the ISDN-SR-Tablet. These results were ascribed to the fact that ISDN given through the transdermal route, in contrast to that given by the peroral route, does not undergo the first-pass effect in the liver. It was concluded that the transdermal dosage form of ISDN, which possesses a more prolonged pharmacologic effect than the oral dosage form, may be useful in the prevention and cure of angina pectoris.

Administration, Topical↗
PubMed1981

[Pharmacological effects of N-acetyl-L-cysteine on the respiratory tract. (I). Quantitative and qualitative changes in respiratory tract fluid and sputum (author's transl)].

The following three experiments were performed to determine the effects of N-acetyl-L-cysteine (NAC) on the quantity and quality of respiratory tract fluid (RTF) and sputum. All drugs used were administered into the stomach through a gastric tube. 1) Indirect measurement of bronchial secretion in rats, which was expressed by the amounts of dye excreted into the respiratory tract, was carried out according the the Sakuno's method, with some modification. Some expectorants of the secretomotor type, such as bromhexine and pilocarpine, significantly increased the secretion, even at low doses. On the other hand, mucolytic agents such as NAC augmented the secretion only in doses of 500 to 1500 mg/kg. 2)As a direct method of measurements, Kasé's modification of Perry and Boyd's method was used to collect RTF, quantitatively, from rabbits. The RTF of healthy rabbits was colorless and watery. The administration of NAC in doses of 500 to 1500 mg/kg augmented the output volume and RTF became slightly turbid, probably due to an increase in the viscous mucus. 3) Rabbits with subacute bronchitis were prepared by long-term exposure to air contaminated with SO2 gas and sputa were collected before and after administration of NAC, respectively, according to the Kase's method. The sputa were opalescent and viscous gel included nodular masses. The administration of NAC, 1000 and 1500 mg/kg resulted in a dose dependent decrease in the relative viscosity. The percent-decreased in viscosity with NAC was statistically correlated with that in amounts of dry matter, those in protein and polysaccharide in the sputa. From the results described above, it was concluded that NAC given into the stomach can liquefy sputum by splitting mucoprotein disulphide linkages, that is, altering the rheological characteristics of sputum to facilitate expectoration.

Acetylcysteine↗
PubMed1980

[Pharmacodynamic effects of the sustained-release tablet of isosorbide dinitrate and its bioavailability in conscious dogs (author's transl)].

Oral administration of isosorbide dinitrate (ISDN), 1 approximately 2 mg/kg, resulted in a dose-dependent decrease in the pulse pressure by reducing the systolic pressure and slightly elevating the diastolic pressure in conscious dogs. Therefore, this system was employed to evaluate the effectiveness of the sustained-release ISDN tablet as compared with that of the standard tablet. Four standard tablets (20 mg of ISDN) given in a single dose significantly decreased the pulse pressure, which became lowest at 2 hr after administration and returned to the near original level at 6 hr. On the other hand, with four sustained-release tablets (80 mg of ISDN) 4 hr was required to produce a maximum decrease, and at 10 hr, the pulse pressure was still much lower than the original level. The plasma concentration of ISDN was measured by a gas chromatographic method. The time course of the plasma concentration of ISDN after administration of each preparation was correlated with that of the decrease in the pulse pressure. This suggests that the system employed is useful in evaluating the bioavailability of various preparations of organic nitrates (ISDN). In addition, these data demonstrate that the sustained-release formulation of ISDN possesses a prolonged pharmacological effect.

Animals↗
PubMed1976

Effects of industrialization on working schedules.

Recent increase in industrialization has resulted in attention being drawn to diversity of working schedules and their interrelation with content of work. The results of joint research revealed that adaptation to industrial jobs is made difficult because of urban conditions and modern work-control systems, such as workers in flexible-working-time systems who apparently favored regular daily working cycles. Long overtime work in smaller undertakings and the spread of shift systems are two important features of industrial work schedules, each being dominant among skilled and non-skilled jobs. Another important facet is the problem of intra-shift work-rest schedules significant for machine operations and vigilance tasks. It is suggested that phases of work that become intolerable are correlated with unnatural work rhythms. More emphasis should thus be laid on both phase-shifted work and non-self-governing work, the key factor being the relevance of attained data to real work in the whole course of schedules of work and rest.

Accidents, Occupational↗
PubMed1976

Spontaneous alternation of the working arm in one-arm cranking.

One-arm cranking was done by ten healthy male adults at an oxygen intake level of about 1.0 liter/min. Each subject performed two kinds of cranking at a speed of 60 rpm: forced cranking using only one arm continuously for 15 min and free cranking for 30 min with the instructions to alternate from one arm to the other whenever fatigue set in. The results, excluding those of a subject who changed arms very frequently, were analyzed. In forced cranking, oxygen intake and heart rate steadily increased, the average time of appearance of local fatigue being 161 sec for the stronger arm and 122 sec for the weaker one. In free cranking, the working arm was changed 6 to 23 times during the 30-minute period, while oxygen intake and heart rate increased with fluctuations. The mean duration interval was 175 sec with the stronger arm and 123 sec with the weaker one. The mean interval of arm alternation was positively correlated with the individual time of onset of the sensation of local rigidness during forced cranking, but not with the individual time of initiation of respiratory distress. It is suggested that alternation of active muscles in moderately dynamic work may be linked with an early stage of local fatigue which is different from that of static work.

Adult↗
PubMed1975

Incidence of near accidental drowsing in locomotive driving during a period of rotation.

The incidence of drowsings as a cause of near traffic accidents was studied on the basis of daily recordings or near accidental events by 288 locomotive drivers during a rotation period of 2-3 weeks. Of 198 near accidents reported during 2,290 trips, 34 cases, or 1,5 cases per 100 trips, were operation missess involving drowsing or strong drowsiness. Improper operation due to drowsing occurred at a certain rate for any group of drivers, irrespective of the type of train, running sections, weather, and other operative conditions such as train delays, whereas 117 cases of danger caused by unforeseen obstacles on the track were related to site characteristics, and 47 cases of other disorders were frequent in unusual operative conditions such as arrival-departure, poor signal display, wrong instructions, or equipment failure. Thus continued driving under ordinary track conditions at a more or less constant speed was likely to induce drowsiness under the dominant influences of fatigue and time of the day; 79% of such cases occurred between midnight and 6 a.m. Most drowsings on the second night appeared during the first 2-4 hr of duty. Effects of monotony and insufficient rest were discussed in relation to recurrent fluctuation in vigilance.

Accidents↗
PubMed1975

Monotony effects of the work of motormen dlring high-speed train operation.

The results of investigations done in 1965, 1966, and 1972 on the workload of motormen of high-speed trains operating on railroads with maximum speeds of 210 km/hr were compared in an attempt to discuss the physiological implications of the driving task. The driving time of a 515 km section was 4 hr in 1965 and was lowered to 3 hr 10 min since 1966 for the fastest super-express trains. The mean heart rate was maintained around 80 beats/min during the entire driving period in 1965, but declined gradually in 1966 or 1972. Although in 1966 the operations at constant high speed appeared to favor cerebral activities, drivers in the 1972 investigation not only showed lowered perceptual and choice reaction performances but also experienced significant increase in errors in detecting signal tones given as a subsidiary task. Polygraphic recordings in 1972 indicated that drivers sometimes fell into drowsing of short duration intermittently, accompanied by temporary drop in heart rate, absence of controller action, and increase of detection errors. These effects were dominant in periods after 90 min of driving. The need to reduce the monotomy effects during underloaded train driving is suggested.

Attention↗