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Biomedical subjects

C Taube

Publications and source records attributed to C Taube.

At least 55 records · Page 3Linked to original sources
PubMed1988

Dazoxiben-induced changes in the thromboxane/prostacyclin balance in the lateral cochlear wall of the guinea pig.

Dazoxiben, a thromboxane synthetase inhibitor, was infused i.v. in a first group of guinea pigs. Saline was given to a second group of animals as controls. Subsequently, the lateral cochlear walls of each animal were prepared and analyzed for thromboxane (TXA) and prostacyclin (PGI) using radioimmunoassay. These studies showed that dazoxiben crosses the blood-labyrinth barrier and shifts the TXA2/PGI2 balance in favor of the latter. The effects demonstrated are discussed with respect to the relevance of prostanoids in cochlear physiology.

6-Ketoprostaglandin F1 alpha↗
PubMed1988

The decision to seek an exemption from PPS.

This paper examines the receipt of exemptions from Medicare's Prospective Payment System (PPS) for distinct part psychiatric units of general hospitals. A logit model of the exemption status of 1,045 psychiatric units is estimated using 1984 data. The results suggest that units that were expected to profit from a change in payment method (cost based on PPS) were least likely to obtain an exemption from PPS.

Data Collection↗
PubMed1988

[Animal experiment and clinical studies of the use of anti-inflammatory agents in chemical burns of the eye].

In animal experiments and a clinical study of chemically burned eyes the anti-inflammatory effect of topically applied steroids and indomethacin (an inhibitor of cyclooxygenase) was investigated. Both the animal model and the clinical tests indicate the desirability of immediate local application of dexamethasone eyedrops 0.1% under careful biomicroscopic control of the burned eye and with local antibiotics. The use of topical steroids is a part of the authors' treatment for moderately severe and severe chemical eye burns (second degree, beginning third degree). However, this anti-inflammatory therapy cannot be recommended with indomethacin alone, because of the leukotriene-induced, increased infiltration of polymorphonuclear neutrophils and corneal ulceration.

Animals↗
PubMed1988

Influence of drugs on the TXA2/PGI2 balance and on the atherogenic index in myocardial ischemia in dogs.

The effect of drugs on eicosanoid production and on the development of atherogenic index was investigated in canine myocardial ischemia. Iloprost, verapamil, the trapidil derivative AR 12463 or 0.9% NaCl solution were administered 60 min after coronary artery ligation in anaesthetized dogs. Both iloprost and AR 12463 reduced the thromboxane A2/prostacyclin (TXA2/PGI2) ratio in coronary sinus plasma in comparison to controls. The atherogenic index was significantly decreased in the iloprost as well as in the AR 12463-treated group in comparison to the control group. Verapamil had no influence on the investigated parameters.

Animals↗
PubMed1988

The early effects of Medicare's prospective payment system on psychiatry.

In this paper, we study the effects on psychiatry of Medicare's prospective payment system (PPS) during 1984, as PPS was implemented. We examined data on psychiatric discharges before and after PPS from three kinds of hospitals--those with psychiatric units exempt from PPS, those with nonexempt units, and those that treated psychiatric patients in scatter beds--as well as data on all hospital discharges. We conclude that the providers of psychiatric services responded to the incentives inherent in PPS much the way hospitals as a whole did--with significantly reduced lengths of stay. Of the three kinds of hospitals that rendered psychiatric care, those that treated patients in scatter beds had the greatest reduction in length of stay. Using readmission rates as a gross indicator of quality, we conclude that quality did not suffer because of the shortened stays.

Data Collection↗
PubMed1988

Decrease in arterial blood pressure in spontaneously hypertensive rats by the TXA2 receptor antagonist BM 13177 and by acetylsalicylic acid.

The effects of the selective TXA2 receptor antagonist BM 13177 and of the cyclooxygenase inhibitor acetylsalicylic acid on blood pressure and heart rate were investigated in anaesthetized spontaneously hypertensive rats (SHR). After intravenous injection of BM 13177 (60 mg/kg) there was a strong short-lasting decrease in arterial blood pressure (BP) with a maximum reduction of 21.6% in the third minute after injection. The heart rate was only slightly decreased. The formation of TXB2 and 6-keto-PGF1 alpha in serum, aorta thoracica, renal medulla, and renal cortex, which was determined by radioimmunoassay, was not altered by BM 13177. Pretreatment with acetylsalicylic acid (100 mg/kg) attenuated the BM 13177 induced reduction of blood pressure and heart rate in male, but not in female SHR. An intravenous application of acetylsalicylic acid (ASA) (100 mg/kg) resulted in a decrease of blood pressure and heart rate only in male rats. The extent of these effects was similar to that induced by BM 13177. A possible explanation for the different reactions of male and female animals might be sex differences in the sensitivity of cyclooxygenase in the aorta thoracica to ASA and/or in the balance of prohypertensive and antihypertensive prostanoids. TXA2 and other prostanoids seems to participate in the short-time regulation of BP in SHR.

Animals↗
PubMed1988

Influence of ion-pair-formation on the pharmacokinetic properties of drugs. Part 3: Influence of hexylsalicylic acid on the pharmacokinetics of pholedrine.

Based on previous in vitro studies it could be shown that ion-pair-formation with the lipophilic hexylsalicylic acid (1) influences the pharmacokinetics of the hydrophilic drug pholedrine (2) which is ionized in all physiological media. After oral combination with 1 an increase of the AUC of 2 could be observed. This finding is due both to the increase of the absorption of 2 and to the decrease of the elimination of 2. After i.v. application the high biotransformation rate of 2 prevents an influence of 1.

Administration, Oral↗
PubMed1988

Effects of trapidil and trapidil derivatives on arachidonic acid and prostaglandin endoperoxide analogue U 46619-induced blood pressure changes in rats.

The influence of trapidil (T) and two selected 5,7-disubstituted s-triazolo (1,5-a)pyrimidine derivatives (TD: AR 12456 and AR 12463) on arachidonic acid(AA)- and prostaglandin endoperoxide analogue U 46619-induced blood pressure changes in normotensive rats was investigated in comparison with the cyclooxygenase inhibitor acetylsalicylic acid (ASA) and the thromboxane A2 (TXA2) antagonist BM 13177. ASA and AR 12456 completely eliminated the second blood pressure depression after injection of AA and simultaneously diminished TXA2, TXB2 and 6-keto-PGF1a formation in murine blood, whereas BM 13177 prevented the return of the blood pressure to preinjection level after the initial brief fall in arterial pressure. BM 13177 and AR 12463 reduced the rise in U 46619-provoked blood pressure by 75% and 58%, respectively. Trapidil had no effect on blood pressure changes stimulated by AA and U 46619.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed1988

Correlations between endogenous prostaglandin E formation in the bone and spongiosa density.

The formation of prostaglandin (PG) E in the femoral head and the lumbar vertebral body of rats under ex vivo conditions after a linoleic acid (LA) rich diet (13.3 J%) has been compared to that of rats after an LA poor diet (0.5 J%). LA rich diet increased the formation of PGE in the lumbar vertebral body. In the femoral head were a similar, but statistically insignificant effect. The spongiosa density in the femoral head and the lumbar vertebral body increased after LA rich diet in contrast to LA poor fed rats. We conclude that the spongiosa density could be modulated by the LA content of the diet possible via alterations of endogenous PG biosynthesis.

Animals↗
PubMed1988

Influence of acetylsalicylic acid and BM 13177 on blood pressure and efficacy of antihypertensive drugs in spontaneously hypertensive rats.

The effects of the cyclooxygenase inhibitor acetylsalicylic acid (ASA) and of the TXA2 receptor antagonist BM 13177 on blood pressure and on the efficiency of antihypertensive drugs were investigated in spontaneously hypertensive rats (SHR). ASA and BM 13177 applicated once caused a significant, but short-lasting decrease in blood pressure in SHR. In contrast, repeated application of ASA (3 x 100 mg/kg) caused a slight, but significant increase in blood pressure. Pretreatment with BM 13177 (60 mg/kg i.v.) did not influence the antihypertensive effect of the drugs clonidine, propranolol and dihydralazine. Pretreatment of SHR with ASA intensified significantly the effect of these drugs on blood pressure, independent of their mode of action, and on heart rate (dihydralazine). The formation of TXB2 in the aorta thoracica in ASA pretreated SHR 20 min after drug application, was more strongly inhibited than was the formation of PGI2. Therefore the TXA2/PGI2 balance shifted in favor of the latter. However, in normotensive rats, ASA was without any effect on blood pressure and on the antihypertensive efficacy of the drugs. In conclusion it could be suggested that prostanoids are involved in the short term as well as in the long term regulation of the blood pressure and in the blood pressure lowering activity of drugs at least in a hypertensive state.

Animals↗
PubMed1987

Inhibition of thromboxane B2 formation of blood platelets by trapidil and other s-triazolo(1,5-a)pyrimidine derivatives.

Trapidil and some other 5,7-disubstituted s-triazolo(1,5-a)pyrimidine derivatives (TPDs) which were shown to have potent actions against platelet aggregation also inhibited in vitro platelet thromboxane A2 (TXA2) biosynthesis in clotting human and rabbit whole blood as well as in arachidonic acid-activated platelet-rich human plasma. The inhibitory potency of TPDs on TXB2 formation paralleled the antiaggregatory effectiveness to a certain extent and decreased in the following order: AR 12456 greater than AR 12463 approximately AR 12464 approximately AR 12465 greater than trapidil. When TPDs were administered orally to rabbits and blood was taken 2 hours later, no changes of serum TXB2 level were observed. After i.v. injection of TPDs in rabbits, the most active TPDs AR 12456 and AR 12463 led to a short-lasting reduction of serum TXB2 by 61.4 and 49.4% resp.. The TXB2 levels returned nearly to pre-treatment level after 80 min. The possibility is discussed that TPDs mainly prevent platelet TXA2 formation by inhibiting phosphodiesterase activity.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1987

[The effect of trapidil and the trapidil derivative AR 12463 on blood pressure and thromboxane formation in spontaneously hypertensive rats].

The trapidil derivative AR 12463 has a much more stronger inhibiting effect than trapidil on different atherosclerotic parameters of the cell cultures obtained from normal intima and fatty streaks of human aorta, on thromboxane (TX) formation and on the aggregation of human platelets in vitro, and on the activity of phosphodiesterase. In addition to these present results, AR 12463 reduced significantly the mean arterial blood pressure of spontaneously hypertensive rats (at a dosage of 20 mg/kg/d administered orally for 2 weeks) in contrast to the same dosage of trapidil. Simultaneously, TX formation is significantly reduced in serum by 48% in aorta thoracica by 29%, and in aorta abdominalis by 19%. Due to these properties, AR 12463 seems to be suitable for a therapeutic and prophylactic strategy in chronic ischemic diseases.

6-Ketoprostaglandin F1 alpha↗
PubMed1986

[Changes in blood pressure and serum lipids with fish diets in patients with mild essential hypertension].

14 male patients with moderate essential hypertension were treated in the cross-comparison with a mackerel and herring diet, respectively, for two weeks. The mackerel diet contained double as much eicosapentaenic (EPA) and docosahexaenic acid (DHA) as the herring diet which served as control. In the serum triglycerides particularly DHS, in the cholesterol esters above all EPA were enriched. In the phospholipids the increase of the two fatty acids was approximately the same. At the end of the mackerel period the serum triglycerides, the total and LDL-cholesterol, the activity of the lecithin-cholesterol-acyl-transferase (CALT) and the serum sodium were significantly decreased. On the other hand, the HDL-cholesterol and the uric acid in the serum significantly increased. Under influence of the herring diet the parameters mentioned appeared only slightly changed. After the mackerel diet also a significantly lower systolic blood pressure was found. The systolic and diastolic blood pressure during a standardized psychophysiological stress test was more diminished at the end of the mackerel period than after the herring diet. The plasma renin activity (PRA) was increased after the mackerel diet. Its increase under the stress test could no more be proved at the end of the mackerel diet. In similar way the stress-conditioned increase of thromboxane B2 could no more be observe both after mackerel and after herring diet. When the results should confirm themselves in long-term studies, a mackerel diet in practicable dosage can be recommended as non-medicamentous treatment of moderate hypertension.

Blood Pressure↗
PubMed1986

Comparative study of the blood pressure effects of four different vegetable fats on young, spontaneously hypertensive rats.

Following the suckling period, four groups of male four-week-old spontaneously hypertensive rats (SHR) were fed semisynthetic diets with 14% (by weight) of either sunflower seed oil [46% 18:2(n-6); linoleic acid (LA)-rich], linseed oil [62.5% 18:3(n-3) + 12.9% 18:2(n-6); alpha-linolenic acid (LNA)-rich], evening primrose oil [9.2% 18:3(n-6) + 71% 18:2(n-6); gamma-linolenic acid (LNA)-rich] or hydrogenated palm kernel fat [1.5% 18:2(n-6); polyunsaturated fatty acid (PUFA)-deficient], respectively, up to an age of 18 wk. All diets enriched with PUFA provoked an attenuation of hypertension development. The effect was lowest in the LA-rich group and highest in the gamma-LNA-rich group. Differences in fatty acid composition of renal phospholipids between groups reflect the fatty acids present in the respective dietary fats. Renomedullary production of PGF2 alpha was significantly reduced in alpha-LNA-rich and slightly diminished in gamma-LNA-rich fed rats. Aortic formation of 6-keto-PGF1 alpha and TXB2 was increased in animals fed the gamma-LNA-rich diet. Thus, the attenuation of hypertension development cannot be explained only by changes in prostanoid formation. Other mechanisms possibly involved should be pursued.

Animals↗
PubMed1986

Long-term effect of mackerel diet on blood pressure, serum lipids and thromboxane formation in patients with mild essential hypertension.

Twelve male patients with mild essential hypertension were put on a diet supplemented with 2 cans of mackerel/day (= 2.2 g daily of eicosapentaenoic acid, EPA, C20:5 n-3 and 2.8 g daily of docosahexaenoic acid, DHA, C22:6 n-3) for 2 weeks within an isocaloric regimen and then with 3 cans/week (= 3.3 g/week, equivalent to 0.47 g daily of EPA and 4.2 g/week, equivalent to 0.69 g daily of DHA) for 8 months with a subsequent period of 2 months on normal diet. Eleven male hypertensives matched for age, body weight index, blood pressure and serum lipids with no change in their nutritional habits served as controls. After the first dietary period (2 weeks) a significant decrease of serum triglycerides (TG), total and LDL-cholesterol, blood pressure and thromboxane B2 (TxB2) was found, whereas HDL cholesterol and potassium in erythrocytes were significantly increased. During the second dietary period (8 months) providing the lower dose of EPA, serum lipids and the other biochemical parameters returned to the initial values. Blood pressure, however, remained significantly lower and rose to the basal levels only after the third period (2 months) on normal diet. In the control group no alterations could be seen. The data suggest a dose-related differential effect of dietary EPA on serum lipids, lipoproteins, TxB2 and blood pressure in subjects with mild hypertension.

Adult↗
PubMed1986

Circadian rhythm of eicosanoid formation as affected by dietary linoleate.

Circadian rhythms of eicosanoid formation were investigated in linoleic acid (LA) rich (sunflower seed oil, 13.3 cal% LA) and LA deficient (hydrogenated palm kernel fat, 0.5 cal% LA) diet fed male Wistar rats adapted to an artificial lighting regimen of 12 hours light and 12 hours darkness. Over a period of 24 hours we examined at 4 hour intervals eicosanoid formation in the aorta (PGI2, PGE, PGF2 alpha), in the heart (6-keto-PGF1 alpha, PGE, PGF2 alpha, TXB2), in the kidney (PGE, PGF2 alpha) and in the brain (PGE, PGF2 alpha). Two types of circadian variation curves were observed: Low eicosanoid formation in the light period and increase in the dark cycle (PGE in aorta and heart, TXB2 in heart). The increase in eicosanoid formation in the dark cycle was diminished after an LA deficient diet. Continuous decrease (PGI2 in aorta) and increase (PGE in the brain), respectively, in the course of the day, without differences between the two dietary groups. We assume that the circadian oscillations of eicosanoid formation might be of importance for the development of the circadian time structure of the organism.

Animals↗