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Biomedical subjects

O Werner

Publications and source records attributed to O Werner.

At least 127 records · Page 7Linked to original sources
PubMed1980

I.V. practolol during microlaryngoscopy. Effect on arterial pressure, heart rate, blood glucose and lipolysis.

Twenty-five patients undergoing microlaryngoscopy were anaesthetized with thiopentone and nitrous oxide with suxamethonium as a muscle relaxant. Thirteen received practolol 0.4 mg kg-1 and atropine 1.5 mg i.v. shortly before anaesthesia. During anaesthesia practolol 0.2 mg kg-1 was given. Twelve (control) received atropine 0.5 mg before anaesthesia. Practolol reduced the frequency of tachycardia and arrhythmia. The treatment group had a greater reduction in systolic arterial pressure during induction. The hypertensive response to laryngoscopy was not significantly attenuated by practolol. A weak hyperglycaemic response to microlaryngoscopy was not affected, nor was the plasma concentration of glycerol.

Aged↗
PubMed1980

[Improved test for the detection of reverse transcriptase of bovine leukosis virus].

The revertase test with exogenous matrix, poly-(rA) . oligo-(dT), for the detection of bovine leukemia virus from crude virus sediments was standardised and miniaturised. An amount of 10 ml of cell culture supernatant of short-term cultured lymphocytes (5 . 10(6) cells/ml) is quite sufficient for testing one cattle sample. The lower sensitivity limit of the test was found to be 10(6) virus particles. The test is properly reproducible, within tolerance limits of +/- 20--30 per cent, provided that optimum lysis conditions be maintained (0.01 per cent triton X-100, 20 minutes, 0--4 degrees C incubation) and under the condition that the protein quantity in 100 microliter test solution does not exceed the threshold of 3--15 micrograms. The specificity of the test is based on the use of free viruses from cell culture supernatant, the optimum temperature of the revertase reaction at 25 degrees C, which actually deviates from that for cellular DNA polymerases, that is 37 degrees C, and magnesium ion concentration which has to be optimum for bovine leucosis virus revertase. Two-hundred heads of cattle, differing by haematological status, were examined, and 56 per cent of them were, clearly, virus producers, among them 95 per cent of all animals with positively established leucosis and 36 per cent of the haematologically intact animals. Examinations of individuals have shown that in repetitive checks, carried out in intervals between two months and one week, the revertase activities varied by something between 0.5 and two magnitudes.

Animals↗
PubMed1980

[Immunoprophylaxis against Marek's disease and its perspectives].

An account is given of the present international position in immunoprophylactic control of Marek's disease. An assessment is made of the method used for immunisation in the GDR. In that context, reference is made to problems for which solutions will have to be found in the long run.

Animals↗
PubMed1980

[Studies on the reliability of hard diagnosis of Marek's disease and lymphoid leukosis of chickens on the basis of pathologic-anatomical findings].

The reliability of criteria for diagnosis and differential diagnosis of Marek's disease and lymphoid leucosis of fowl, as part of herd diagnosis and on the basis of pathologico-anatomic findings as well as of pathomorphological and statistical tests has been checked for treatment in this paper. Tumorous lesions were macroscopically and histologically recorded from 1,261 hens of various industrialised poultry units. Marek's disease was established in 316 cases, lymphoid leucosis in 828 cases, mixed manifestations in 33 cases, and other neoplasias in 84 cases. These animals, together with 591 hens in which Marek's disease had been experimentally induced, were evaluated by pathologico-anatomic criteria of differential diagnosis. The conclusion was drawn that differential diagnosis of Marek's disease and lymphoid leucosis on the basis of pathologico-anatomic findings, without histological testing, was sufficiently reliable, when undertaken as part of herd diagnosis monitoring. The expected small number of false diagnoses will be unimportant to herd diagnosis. Both diagnosis and differential diagnosis will be conducted by the following criteria: age of animal, alterations caused by Marek's disease to nerves, eyes, and skin, tumour growth in bursa fabricii caused by lymphoid leucosis, atrophy of bursa fabricii caused by Marek's disease, as well as differences between both diseases regarding tumour development in other organs, with due consideration to be given to the number of affected organs, as a whole, and to pathologico-anatomic organic changes caused by tumour growth.

Animals↗
PubMed1979

Compact digital storage of ECG's.

The technique of predictive coding is applied to the problem of reversible compression of digitized electrocardiograms. Integer-based predictors and MMSE predictors are studied as regards performance at varying sampling rates and digital resolutions for both long-term ECGs and ECGs recorded at rest. It is concluded that MMSE predictors are to be preferred only in the case when the ECG is oversampled (i.e., the sampling rate is much higher than twice the cut-off frequency of the presampling filter). In other cases the integer predictor which yields the so-called 2nd differences is superior. The problem of encoding the resulting residuals with a variable-length code is studied for long-term ECGs digitized at 100 Hz and using 8 bits digital resolution. The code has a simple struture leading to speed of execution while the efficiency loss is small.

Computers↗
PubMed1979

Effects of prolonged administration of metiamide on serum gastrin, gastrin content of the antrum and gastric corpus, and G-cell population in the rat.

The effect of prolonged metiamide administration on serum gastrin, gastrin content of the antrum and gastric corpus, and G-cell population was studied in the rat. A single subcutaneous injection of metiamide (200 mg/kg) at the onset of 16 days of continous treatment with three daily injections was followed by a fivefold increase in serum gastrin level at 4 hr in fasted and at 4 and 6 hr in fed rats. After 16 days of metiamide, the fed rats showed a peak in serum gastrin level of the same magnitude as on day 1, but only at 4 hr. Two hours later, the levels decreased rapidly to basal values. In the fasted animals, the response to metiamide was reduced to a threefold increase at 2 hr. There was no difference in gastrin content of the antrum and gastric corpus nor in volume density of the G-cells after the prolonged treatment compared with the controls. It is concluded that in spite of rises in serum gastrin, prolonged metiamide medication has no effect on the gastrin content of the antrum and gastric corpus nor on the G-cell population in the rat. Furthermore, after prolonged treatment, metiamide-induced gastrin release is diminished.

Animals↗
PubMed1978

[Gastric secretion and gastrin values following portocaval and splenocaval shunts in the rat].

The basal and gastrin-stimulated gastric acid output was measured in rats with a distal splenocaval shunt. In addition, serum gastrin levels were determined in rats with splenocaval and portacaval shunts. The rise in gastric acid output with increasing gastrin dosage was the same in rats with splenocaval shunt as in the controls. Serum gastrin levels were not influenced by portocaval or splenocaval shunting.

Animals↗
PubMed1976

Experience of computer-assisted ECG recording in 242 exercise tests.

242 computer-assisted exercise tests were studied. The computer performs simultaneous averaging of a 6- or 12-lead ECG, keeps track of the work load and time and labels all ECG records. Less than 1 per cent of atrial and ventricular extrasystoles were included in the computer average together with ordinary beats, while 80 per cent of all beats were averaged. Averaging reduced the peak-to-nadir QRS amplitude by 3-4 per cent at a sampling rate of 400/s and by 8-9 per cent at 200/s. Q waves with small beat-to-beat variation were usually well preserved after averaging while more variable QRS details often decreased in width or amplitude. The averaging program performed adequately on most kinds of arrhythmia. Averaging should not be used on pacemaker ECGs. Caution must be exercised in the presence of very frequent ventricular extrasystoles.

Arrhythmias, Cardiac↗
PubMed1976

Computer classification of ST and T in averaged ECGs at rest and exercise.

A computer program for ST and T classification at rest and exercise is described. The automatic ST classification was based on the modification of the Minnesota code suggested by Punsar et al. The T wave classification was based on the Minnesota code of 1968. Recordings at rest, during and after exercise from 217 exercise tests were visually classified by two observers, and their result was compared to the computer's. Computer-observer comparisons yielded no more disagreements than between-observer comparisons. There were computer-observer disagreements caused by computer errors in 3% of the records. The repeatability of the computer's ST classification on records taken during exercise was better than that of one visual observer. Within-computer and within-observer repeatability appeared to be negatively affected by remaining noise in the average.

Adult↗
PubMed1976

A system for computer-assisted ECG recording at rest and exercise.

Great investments have been made in computerized ECG interpretation but little attention has been paid to rationalization of such costly activities as recording, labelling and mounting ECGs, and still less to the presentation of ECGs. A system for such tasks is described. It includes a PDP8/E computer and modified ink jet ECG recorders, which write alphanumeric text and function as analogue input- and output-devices for the computer. On-line computer service is given independently to two laboratories for ECG at rest, VCG or exercise ECG. After averaging the ECG signal, the computer writes out a properly labelled ECG in an easily surveyable form. The visual interpretation of the ECG is entered and is then written on a new sheet together with the averaged 12-lead ECG and a rhythm strip. In exercise testing, the computer records and processes the ECG at predetermined intervals. The processing includes an automatic ST classification. A summarized presentationof the ECG before, during and after exercise allows easy visual identification of ECG changes. Experience of the system has mainly been obtained from 2 years of routine exercise ECG recording and to a limited extent from ECG and VCG recording at rest.

Cardiology↗
PubMed1975

Noise reduction of ECG by averaging. An experimental study of the procedure and a validated method.

Electrical noise often hampers the interpretation of ECG and other heart-synchronous signals. Time-coherent averaging is a commonly used method to reduce the noise. This method has been implemented on a computer with 12,000 12-bit words of core memory, suitable for on-line use in any clinical laboratory. An analysis was made of which demands apply to the exactness of synchronization of added heart cycles. The method was tested with respect to these demands and also, on a limited scale, for its efficiency in eliminating ectopic beats from the average.

Computers↗