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Biomedical subjects

H Walther

Publications and source records attributed to H Walther.

At least 145 records · Page 8Linked to original sources
PubMed1984

[Prevention, clinical aspects and therapy of the side-effects of lidocaine].

In 134 patients with an acute myocardial infarction a prolonged lidocaine infusion was performed. In 6.7% of the patients severe side effects occurred. They appeared with central-nervous and haemodynamic symptomatology. In 6 patients with a high degree of severity of the side effect a determination of the plasma content could be performed, which in every case showed contents during the process above the therapeutic region. It was confirmed that side effects of lidocaine are to be apprehended, when the therapeutic region (2-6 mg/l-1) of the antiarrhythmic drugs is transgressed. On the basis of own experiences and reports from literature the therapeutic approach in lidocaine side effects is concerned and possibilities are shown to avoid them.

Arrhythmias, Cardiac↗
PubMed1984

[Lidocaine elimination and dose adjustment in acute heart infarct and heart insufficiency].

In 40 patients with an acute myocardial infarction a prolonged lidocaine infusion was indicated. The dosage of lidocain was done according to the body-weight. Patients suffering from a heart insufficiency received the anti-arrhythmic drug with a reduced dose referring to the degree of severity. The lidocaine-plasma content was determined by means of a gas-chromatographic method. Furthermore, the half-value time, the clearance and the distribution coefficient were computed. Despite the reduction of the dose the plasma contents were highest in patients with manifest heart insufficiency. As we expected, the half-value time was shorter in the patients with infarction without heart insufficiency than in the patients with manifest heart insufficiency. The behaviour of the total clearance was analogous in the adequate groups of patients. The lidocain dosage performed which referred to more recent investigations of the behaviour of the half-value time after prolonged infusion is regarded as more precisely in comparison to the previous proposals. Corresponding to the findings got, a dosage scheme is given for patients with myocardial infarction and heart insufficiency, which should allow a secure and effective treatment.

Dose-Response Relationship, Drug↗
PubMed1984

[Isolated liver perfusion in advanced metastases of colorectal cancers].

A special cannulation system was developed in order to completely isolate the liver in an extracorporeal circuit. Isolated hyperthermic liver perfusion at 40 degrees C with an average dosage of 1000 mg 5-FU was performed in 32 patients with liver metastases (29 colorectal carcinomas, 2 carcinoids, 1 primary hepatoma). 12 patients who had an overall 45% tumor invasion of the entire liver-volume as measured in CT-scan were treated exclusively by isolated liver perfusion. In that group median survival was 8 months and death occurred in the presence of extrahepatic metastases. Better results are achieved with isolated liver perfusion followed by intraarterial short-time infusions (Mitomycin C/5-FU) via an Implantofix catheter. Median actual survival in this group is 12 months, the longest follow-up period is 23 months.

Chemotherapy, Cancer, Regional Perfusion↗
PubMed1984

[Isolated hyperthermic extremity perfusion with vindesine, dacarbazine and cisplatin in the treatment of malignant melanomas].

A three drug combination consisting of dacarbazine, vindesine and CDDP (DVP) was used for isolated extremity perfusion in 26 patients with stage I, II and III melanomas of the limbs. Dosages of 100 mg/l dacarbazine, 0.4 mg/l vindesine and 20 mg Cis-Platinum/l extremity volume have been tolerated without major side effects. All perfusions of bulky tumors or metastases resulted in more than 50% tumor-size reduction (8 patients stage III A, 6 patients stage III AB). In five stage III patients relapse occurred 2, 3, 5, 6 months after isolated DVP perfusion.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1984

[Effect of drugs on human discrimination ability].

The effects of phenobarbital, nitrazepam, diazepam, medazepam, chlordiazepoxide, phenytoin, carbamazepine, thioridazine and caffeine on the detail discrimination ability of healthy subjects were compared with those of a placebo by means of the d2-test and the Bourdon-Wiersma test. The impairment of performance induced by phenobarbital, thioridazine and diazepam varied with dosage. The improved performance yielded by caffeine was related to both dose and time. Both deletion tests yielded the same results. They are suitable for detecting the effects of drugs and have proved useful for clinicopharmacological and clinicopharmacological and clinicopsychopharmacological studies.

Adult↗
PubMed1983

First experimental and clinical results of isolated liver perfusion with cytotoxics in metastases from colorectal primary.

In two patients suffering from numerous liver metastases in both lobes from colorectal primary isolated liverperfusion with 5-fluorouracil was performed. By means of a special cannulation system the hepatic artery and the portal vein were arterialized. The patients recovered rapidly after the operation. Sonographic measurements, CAT scans, pulse cytophotometry, and second-look operations with histological examinations of metastatic tissue verified extensive tumor regression. No complications occurred within 6 months after the perfusion treatment.

Animals↗
PubMed1983

[Influence of personality traits on reaction performance in volunteers after a single administration of placebo, crotylbarbital and caffeine].

We examined the influence of single applications of placebo, caffeine (7 mg/kg), and crotylbarbital (2 mg/kg) on reaction and attention performance in 15 volunteers. A newly developed reaction-time apparatus permits the reaction time to be split for differentiation between initiation time and movement time. Moreover, simple and complex attention performance can be quantified. The volunteers were selected as to the dimensions of "introversion/extraversion" and "emotional lability/stability" by means of the Freiburg Personality Inventory. Labile volunteers responded to placebo faster than stables. Caffeine improved mainly the performance of introverted subjects. Crotylbarbital was without influence on the reaction time at the threshold dose applied.

Adult↗
PubMed1983

[Significance of caffeine values in serum, saliva and urine--determination of pharmacokinetic data by non-invasive methods in psychopharmacologic studies].

For psychopharmacological studies with caffeine two reliable non-invasive methods are available in order to determine pharmacokinetic parameters simultaneously with psychometric tests, without any appreciable impairment of the experimental subject. The investigation were performed in 13 healthy volunteers. Caffeine was determined in serum, saliva and urine. The caffeine level in saliva was about 70% of that in serum, corresponding to the percentage freely dissolved in serum. A good correlation was found to exist between elimination half-lives for serum and saliva levels (r = 0.9702) as well as serum and urine values (r = 0.8784). The amount of caffeine excreted in urine in its unmetabolized form was 1.1 +/- 0.2% of the dose administered. Furthermore, the saliva level was seen to represent the serum level on a broad scale. Sixty minutes after oral uptake, saliva levels were falsified due to adsorption of caffeine to the buccal mucosa. The special pattern of the saliva level during the phases of absorption and distribution is discussed.

Administration, Oral↗
PubMed1983

Effect of an acute dose of crotylbarbital on reaction time and attention testing in healthy human subjects.

The effect of an acute dose of crotylbarbital (2 mg/kg) on reaction time and attention testing was studied in 12 volunteers. This dose appeared to be a threshold for which both performance impairments and improvements were found. Relationships to the vigilance level of the subjects were established. The problem of reactive exertion increase is discussed in conjunction with crotylbarbital concentrations in the subjects' saliva.

Adult↗
PubMed1983

[Biologic availability of caffeine in subjects with regard to the variability of the elimination half life].

400 mg of caffeine and sodium salicylate (= 220 mg of caffeine) were given orally and intravenously (at an interval of one week) to six test persons. The serum levels were determined; and certain pharmacokinetic parameters were measured, using an open one-compartment model. Finally, the absolute bioavailability was calculated. With one of the test persons this experiment was repeated ten times to evaluate the extent of the intra-individual variability of the half-life period and its repercussions on bioavailability.

Adult↗
PubMed1983

[Determination of hepatic metabolic capacity: antipyrine pharmacokinetics in circulatory liver damage due to cardiac insufficiency].

As it was demonstrated in a study, antipyrin halftime and clearance totalis are prolonged resp. reduced in patients with circulatory liver damage due to cardiac failure in myocardial infraction (group H) and in patients with chronic congested liver due to diseases of the heart valves (group V). group H: t50,2 +/- 11,7 h, Cltot 27 +/- 13,3 ml. min-1; group V: t50 19,3 +/- 6,3 h, Cltot 21,9 +/- 8,6 ml. min-1. Those patients with acute myocardial infarction and normal liver condition had a prolonged half-time as well though the clearance was decreased just insignificantly (t50 12 +/- 4,9 h, Cltot 42,6 +/- 15,8 ml. min-1). In the three groups we obtained the expected biochemical results. There was only a slight correlation of both the antipyrin half-time and the clearance totalis to biochemical parameters, Conclusions: In chronic inflammatory liver diseases and other forms of hepatic malfunctions as well as in circulatory liver damages the antipyrin half-time is influenced. Because of this reason, reduction of metabolic capacity should be expected. It is referred to necessary adaptation of the drug doses if capacity limiting medicaments are administered to patients with circulatory liver damage.

Aged↗