PubMed Health⌕ Search

Biomedical subjects

J Schnitker

Publications and source records attributed to J Schnitker.

At least 37 records · Page 2Linked to original sources
PubMed1997

[Activation of blood coagulation and fibrinolysis after angiocardiography with ionic and non-ionic contrast media].

PURPOSE: To study the effects of a ionic (amidotrizoate) and a non-ionic x-ray contrast medium (iopromid) during routine levocardiography and coronary angiography, we employed assays that detect reaction products of thrombin and plasmin to assess the activation of the haemostatic system. METHODS: Subsequent to informed consent, 20 patients were randomly assigned to receive either amidotrizoate or iopromid during standard levocardiography and coronary angiography in a double-blind comparative study. Groups were comparable in respect of age, weight, sex and severity of the disease. No anticoagulation was provided. Coronary angiography was performed according to a standardised protocol. Consumption of contrast media and duration of the examination were comparable in both groups. RESULTS: Thrombin generation (F.1+2) and thrombin activity (TAT) were higher with the ionic contrast medium but did not attain statistical significance. Fibrin generation and degradation as expressed by D-dimer fibrin split products was significantly increased in patients who had been receiving amidotrizoate (p < 0.05, U-Test). CONCLUSION: The non-ionic x-ray contrast medium induced significantly less haemostatic activation in vivo than did the ionic medium amidotrizoate. These data suggest that earlier in vitro observations of more pronounced anticoagulant effects of ionic x-ray contrast media are of limited significance for the evaluation of in vivo effects of x-ray contrast media on haemostatic function.

Angiocardiography↗
PubMed1995

The influence of the dose of ethinylestradiol in oral contraceptives on follicle growth.

This prospective, randomized comparative clinical study involving 416 women investigated follicle development over a period of 12 oral contraceptive treatment cycles. Women were allocated to two groups, one group (n = 207) received a preparation containing 30 micrograms ethinylestradiol and 75 micrograms gestodene daily, and the other group (n = 209) received 20 micrograms ethinylestradiol and 150 micrograms desogestrel, daily. Follicular development was monitored by transvaginal ultrasonography of the ovaries, during days 18-21 in the pretreatment cycle and in treatment cycles 1, 3, 6, 9 and 12. Follicular development was found to be twice as frequent in the group receiving 20 micrograms ethinylestradiol/desogestrel as in the group receiving 30 micrograms ethinylestradiol/gestodene. For all cycles, follicles of 10-30 mm were found in 18% of women in the desogestrel group, compared with 9.7% in the gestodene group, whilst follicles with a diameter of >30 mm were present in 5% of the desogestrel group compared with 1.9% of the gestodene group. The difference between the treatment groups with respect to follicle diameters of 10-30 mm and >30 mm was statistically significant (p < 0.05 and p < 0.001, respectively). No ruptured follicles were observed in either group throughout the study, suggesting that there was no escape ovulation, however, there was one pregnancy in the desogestrel group that could not be explained either by drug interactions or missed pills. It can be concluded that the ethinylestradiol dose in an oral contraceptive has a significant effect on follicular ovarian activity, and that reducing the dose to 20 micrograms is associated with a significant increase in follicle size.

Adult↗
PubMed1994

Clinical experience with a modern low-dose gestodene-containing oral contraceptive in adolescents.

This clinical investigation of a low-dose, monophasic gestodene-containing oral contraceptive (75 micrograms gestodene/30 micrograms ethinylestradiol), investigated contraceptive efficacy, tolerability, cycle control and compliance in 5602 adolescents. The investigation was carried out over a period of 6 cycles. The average age of the study population was 16.4 years; however, only 12 women (0.2%) were under the age of 14. With regard to contraceptive efficacy, during the course of the study there were 5 pregnancies, of which 3 were attributed to user failure. Two pregnancies were recorded as method failure, giving a Pearl Index of 0.08. Cycle control with monophasic gestodene was observed to be excellent. The incidence of spotting and breakthrough bleeding was low and declined during the course of the study, as did amenorrhea. The preparation was tolerated well and the incidence of side-effects was low, with only 4.4% of women withdrawing from the study due to adverse events. An increase in body weight was uncommon, and, at cycle 6, 91.2% of women had not gained weight. At the end of the study, 85.0% of women rated monophasic gestodene as good and 9.6% as satisfactory.

Adolescent↗
PubMed1991

Clinical experience with a modern low-dose oral contraceptive in almost 100,000 users.

Efficacy, cycle control, tolerance, and adverse events were studied in a clinical Phase IV study using a new progestogen, gestodene, in an amount of 75 micrograms combined with 30 micrograms ethinylestradiol. The study was performed as a multicenter trial in 96,000 patients over a period of 6 cycles. Half of the patients taking the new preparation were first-time OC users, the other half switched from another OC. With regard to contraceptive efficacy, the life-table analysis showed a value of 0.032% for method failure and 0.114% for patient failure. The correspondent Pearl-Index is 0.062 and 0.22. The new drug was found acceptable by more than 90% of the women involved in the trial. Dysmenorrhea present in the "switchers" mostly disappeared on the new OC, while body weight and blood pressure remained virtually unchanged. Thus, it can be concluded that blood pressure and body weight behaviour is similar to that seen with other low-dose OCs. The new combined pill offers excellent cycle stability and has a very favourable effect on dysmenorrhea. The number of clinically diagnosed thrombotic events documented in this study was 0.65 per 1000 woman-years (TWY) and does not exceed the range of events seen in groups of women using non-hormonal methods of contraception (Oxford-FPA study 0.4/TWY and RCGP study 0.8/TWY).

Adult↗
PubMed1990

Long-term experience with a low-dose oral contraceptive.

Oral contraception has proved to be the most efficient reversible method of fertility control for over 25 years. During this period, various investigations and epidemiological studies have suggested that some risks may be involved, but, on the other hand, a number of non-contraceptive benefits have become obvious. The results of these investigations were taken into account when new formulations had to be developed, with an aim to improving hormonal fertility control with regard to its tolerance, cycle control, and impact on metabolism. Since then, the objective of research has been to contrive new hormonal contraceptives which ensure safety to the largest possible extent, from a medical point of view, for the sake of the patient, without affecting contraceptive effectiveness. The aim to reduce side-effects connected with the use of oral contraception, as well as to lower the risks possibly involved, has obviously been achieved by extensive research. Both by devising a new substance and reducing doses, the criteria of modern low-dose oral contraception have been met, as has become evident in the course of the clinical experience gathered with Femovan.

Acne Vulgaris↗
PubMed1983

Statistical procedures in clinical pharmacology: decision-theorectic foundations.

The function of statistical analysis is to reach optimal decisions in situations of principal uncertainty. The foundations of statistical procedures are experiments X, whose distributions PX are characterised by random samples. Within given classes of distributions (distribution hypothesis) mathematical statistics make optimal procedures available, which allow conclusions on the real properties of PX. The use of optimal procedures minimises the risk of incorrect decisions made on the basis of random samples (principle of greatest chance). Statistics, however, refrain from any statement on the quality of the decision to which a procedure in a certain situation leads. Against a decision-theoretic background of statistical decisions the growing complexity of clinical-pharmacological test models leads to the necessity of using descriptive-statistical methods on an even larger scale. The aim should be to reduce the number of individual parameters to a few important factors, so that the relation between the number of trial subjects on the one hand and the number of parameters on the other remains valid for meaningful statistical statements.

Clinical Trials as Topic↗
PubMed1983

[Serum and urine electrolyte behavior under therapeutic dosage of a potent magnesium and aluminum hydroxide containing antacid].

Report is given concerning a clinical study on 15 healthy volunteers who received 4 x 10 ml/die Maalox 70 or placebo. The influence on the serum electrolytes calcium, magnesium, aluminium, and the phosphate concentration has been determined by daily monitoring. Furthermore the renal elimination rates for calcium, magnesium, aluminium, and phosphate as well as urine pH, and osmolality have been determined. The quality of stools of the volunteers was monitored. The results were proved statistically. The study led to the following results: The drug has been tolerated subjectively. The stool quality and quantity of the subjects did not change. Magnesium- and aluminium concentration in serum shifted to higher concentrations. At the same time the renal magnesium- and aluminium excretion increased, and the phosphate elimination decreased. This shifting was within the physiological limits, so that relevant clinical side effects could not be observed. All other parameters did not change.

Adolescent↗
PubMed1983

[A test model for cerebrally-active drugs as demonstrated by the example of the new substance aniracetam].

1-Anisoyl-2-pyrrolidinone (aniracetam, Ro 13-5057) belongs to the group of cyclic GABA-derivatives. The compound showed a protective effect on the central nervous system in animal experiments. This paper reports on a clinical investigation in 60 patients of a geriatric and nursing home. The resocializing and the revitalizing effect were the observed parameters. The criteria were recorded by the physician and the staff. The results show that the evaluations by physicians and nursing staff were in good accordance. Aniracetam was effective with respect to the indication: cerebrovascular insufficiency.

Aged↗
PubMed1982

[Uroprotection with mesna in the chemotherapy of malignant tumors with oxazaphosphorines. Biometric evaluation of a sequential clinical study].

A multicentre, randomised, clinical study was performed by sequential analysis to quantify the uroprotective efficacy of sodium 2-mercaptoethane sulfonate (mesna, Asta D 7093, Uromitexan) during high-dosed chemotherapy with oxazaphosphorines. Patients were entered as matched pairs serially according to time of admission, trial centre, cytostatic therapy (cyclophosphamide, Endoxan; ifosfamide, Holoxan) and tumor diagnosis, and were given uroprotection at random either with mesna or standard prophylactic measures. The maximum number of erythrocytes in the urine (n/microliter) was chosen as effect variable in a qualitative manner: effective protection delta less than or equal to 15 erythrocytes/microliter urine ineffective protection delta greater than 15 erythrocytes/microliter urine. The scheme of sequential analysis was based on 1. a uroprotective efficacy of 70% of the standard prophylaxis, 2. an assumed efficacy of 95% of mesna treatment and 3. an alpha-error and beta-error of 0.05 and 0.10 respectively. The admission of the twentieth patient completed the eighth matched pair of patients. This pair proved to be the sixth discordant pair with regard to uroprotective efficacy. The significant uroprotective superiority (p less than 0.05) of mesna was proven in view of clear decisions in favour of the test compound.

Hematuria↗
PubMed1982

[Efficacy of an etofylline-cyclandelate combination in age-dependent cerebrovascular insufficiency].

The pharmaceutical preparation Eucebral-N contains 80 mg etofylline and 100 mg cyclandelate. The drug is used curatively and preventively for peripheral and central circulatory disturbances. This report describes a study in which subjective statements of old patients from a home for the aged have been objectivated and evaluated. The results of the study, evaluated with usual statistical methods are: the communication ability, the state of confusion as well as the psychomotorical retardation could be improved significantly after 4 weeks', administration of the drug.

Aged↗
PubMed1982

Antibody formation after vaccination with adsorbed and non-adsorbed A/New Jersey/8/76 influenza vaccines.

A study was carried out to determine the titres of haemagglutination inhibiting and neuraminidase antibodies after vaccination of 90 subjects, aged 19 to 35 years, with three aluminium oxide adsorbate and three fluid monovalent influenza A/New Jersey/8/76 vaccines with 54, 108 and 216 IU/dose. Blood samples were taken 1, 3 and 6 months after vaccination. The serological findings showed that adsorbate vaccines induced higher antibody titres than did fluid vaccines with double the antigen content. 'Unprimed persons' reacted to the adsorbate vaccine vaccination with a much higher antibody formation response.

Adsorption↗
PubMed1982

[Pharmacokinetic studies on plasma elimination half-life of oxipurinol (author's transl)].

In a randomized cross-over study with 10 volunteers two different commercial preparations of allopurinol (Remid and standard) were tested by reversed-phase HPLC with respect to their pharmacokinetic behaviour. After a single p.o. dose of 300 mg allopurinol plasma elimination half-life of the major metabolite oxipurinol was found to be about 40 h with both preparations, calculated from the course of the plasma levels. This result confirms that a single daily dose of 300 mg allopurinol in non-retard formulation supports therapeutically sufficient circadian plasma levels.

Adult↗