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Rumen fluid from sheep (non adapted to glycerol) was incubated up to six hours under anaerobic conditions with buffer and mineral solution. Wheat starch was added as substrate in an amount of 1g DM per vessel. Glycerol was additionally admitted to rumen fluid in amounts of 5 to 50% of starch. Carrier-free 14C-glycerol (1.3-labelled) or 15N-labelled NH4Cl were added to different incubation vessels. The disappearance rate of glycerol depended from the amount of added glycerol and incubation time. More than 90% of glycerol disappeared in 2 hours (5% addition), 4 hours (10% addition) and 6 hours (15 to 25% addition) respectively. The sum of volatile fatty acids elevated significant with a higher glycerol addition and 6 hours incubation time. The concentration of propionic acid increased also in dependence of the added glycerol amount and the longer incubation time. The proportion of acetic acid to propionic acid changed from high values (3.5 to 4.0, without glycerol) to the lowest value from 2.5 after 6 hours incubation time and 25% glycerol addition. The most radioactivity of added 14C-glycerol was found in propionic acid and only up to 11% in CO2. 14C-radioactivity was not detected in methane, lactic acid and acetic acid respectively. The 15N-labelling of TCA-precipitable N-fraction was not influenced by glycerol supplementation but the 15N-incorporation in the bacterial nitrogen fraction was lower in the vessels with glycerol.

In order to reduce side effects of high-dose chemotherapy the penetration of the cytostatic substances into the main circulation should be prevented or limited. An efficient procedure for checking the leakage is generally based on the addition of a radionuclide to the perfusate. By scintillation probes the distribution of this radionuclide in the body of the patient is checked. A method is presented which continuously calculates the actual volume of the fluid which is penetrating into the main circulation during the perfusion. The values of momentary and cumulative volume crossover enables the surgical oncologist to detect a leakage readily and reliably and may be the basis for measures of confining it.

Male Wistar rats (initial weight 58 g) received in four groups (10 animals per group) 0.0, 10.6, 21.3, and 31.8% glycerol in the dry matter of the diet (groups 1 to 4). The live weight gain of the animals was, after a feeding time of 3 weeks in the groups 1 to 4, 2.01, 2.49, 2.57, and 2.52 g, respectively, per animal and day. The higher gain in the glycerol groups resulted from the higher feed intake in these groups. Four rats per group received on the 22nd day of the experiment, 1 h after the morning meal, an intraperitoneal injection of carrier-free 14C-glycerol. The 14C-excretion in the respiration air and in the urine was measured in the following 10 h. The 14C-excretion in the 14CO2 of the respiration air was in % of the injected 14C-glycerol doses in the groups 1 to 4 = 45.4, 44.2, 39.0, and 33.2, respectively. The 14C-excretion in the urine was 17.0, 18.1, 25.1, and 32.3%, respectively. The higher values in groups 3 and 4 resulted from the high excretion of free glycerol in the urine. In groups 3 and 4 the glycerol content of the blood plasma was 1.9- and 1.5-fold higher than in groups 1 and 2. It was concluded that up to 40 mg glycerol per hour and animal (100 gLW) was metabolized in a physiological way in group 2. As a feeding component glycerol can constitute up to 10% of the diet-DM in monogastric animals.

The 5,6-dimethylbenzimidazole unit of vitamin B12 is formed from riboflavin via FMN in aerobic and some aerotolerant bacteria. Thereby C-1' of the ribityl side chain gets C-2 of 5,6-dimethylbenzimidazole. Experiments with homogenates of Propionibacterium shermanii on the fate of C-atoms 2' to 5' of the ribityl side chain of riboflavin in this transformation are reported. It was found that [5'-3H]riboflavin leads to radioactive sugar phosphates. These were isolated, dephosphorylated, and separated. Thus 3H-D-fructose and 3H-D-glucose were detected. The degradation of 3H-D-glucose revealed that 14 per cent of the total radioactivity was located in C-1, and 86 per cent in C-6. This indicates that during 5,6-dimethylbenzimidazole biosynthesis a three carbon unit is formed from the ribityl side chain of riboflavin.

In 5 normal persons, 1 patient with pernicious anemia, 5 patients with renal insufficiency in the state of compensation, and in one patient with chronic hemodialysis Schilling tests, activity of 57Co and vitamin B12 serum levels were measured. It was obvicous that activity of 57Co in serum 8 hours after oral application of 0.5 muCi 57Co-vitamin B12 showed reliable results to clear the problem of vitamin B12 malresorption. This method is easier than the Schilling test because the collection of 24-hour-urine is not necessary and an insufficiency of renal function does not influence the result.

The isotope dilution technique was used to study the oestrogen component of "Deposiston", a long-acting contraceptive, and its effects on blood volume. Blood volume increased by about ten per cent within 15 days from administration of 3 mg of ethinyloestradiol-sulphonate (1 mg/week). Haematocrit was reduced, at the same time. This haemodynamic initial effect should be always taken into account for any assessment of biochemical parameters in response to hormonal contraception.The isotope dilution technique was used to study the estrogen component of Deposiston, a longacting contraceptive, and its effect on blood volume. Blood volume increased by about 10% within 15 days from administration of 3 mg of ethinyl-estradiol-sulphonate (1 mg/week). Hematocrit was reduced at the same time. This hemodynamic initial effect should always be taken into account for any assessment of biochemical parameters in response to hormonal contraception. (author's)

Attempts to measure coronary blood flow in man have made considerable progress during the last 25 years. The major techniques are based on the direct or indirect Fick principle; coronary flow is calculated from the arterio-coronary venous difference of inert gases or from the precordial recorded disappearance curve of radioactive gases or substances. The accuracy of the techniques depends upon the properties or the indicators used and the precision of their determination. All techniques applied hitherto are intricate and unsuitable for general use. -A lot of information is obtained about coronary circulation in health and disease by coronary flow measurements in man. Further studies in this field may influence pathophysiological and clinical concepts especially concerning coronary heart disease.

Radioisotopic time-activity curves can be described by a function known from the physics of heat conduction. This function, called in this paper "tracer function", is a special solution of one-dimensional differential equation of heat conduction. The function is especially useful in the quantitation of left-to-right cardiac shunts by analysis of the pulmonary time-activity curve. The first transit curve is determined from the amplitudes on the ascending slope of the curve only including the maximum. The shunt curve analysis uses two parameters derived from the first transit curve and then the position and amplitude of the shunt curve maximum only.

In 10 patients with arterial occlusions, 125-I fibrinogen was injected intravenously. In all patients with acute embolic or thrombotic arterial occlusions verified surgically and/or angiographically, a significant accumulation of radioactivity in the affected region was observed. The use of 125-I fibrinogen in this manner obviously is a valuable means for the detection and localization of acute arterial occlusions.

Nucleic acid hybridization techniques (e.g., Southern blotting and in situ hybridization) gain increasing importance in laboratory medicine, as demonstrated by examples in this paper. The molecular basis of this approach to detect nucleic acids homologous to known DNA probes is explained. It is concluded that this technique has advantages in the detection of pathogens compared to other methods used in laboratory medicine.

The aim of this study was to demonstrate the advantage and validity of 133Xe-washout externally monitored by the scintillation camera. Until now there were no reports on quantitative blood flow studies in Hyperacute rejection of transplanted kidneys using a scintillation camera. Within 35 minutes after e-vivo hemoperfusion of rabbit kidneys by cats we found a simultaneous progressive decrease of renal blood flow, renal cortical blood flow as well as of the intrarenal distribution of renal cortical blood flow in all cases. The hyperacute rejection of xenografts could be verified in every case histologically. Using the scintillation camera we were able to detect regional perfusion defects caused by artifical air embolism as well as by preexisting cortical infarction.

Examination of 80 patients with essential hypertension revealed a significant correlation between the tonus of peripheral muscular arterioles on the one hand, and the stage and duration of hypertension and age of the patients, on the other hand. The correlation between arteriolar tonus and indicators of cardiac pump function was less marked. The results confirmed the close relationship between changes of peripheral blood bed and development of hypertension. The use of 133Xe half-period for measuring the peripheral arteriolar tonus proved a simple, but informative method adding an important indicator of peripheral haemodynamics to the results of haemodynamic examination.

Regional cerebral blood flow (rCBF) was investigated in 18 patients with acute cerebral ischemia by the intraarterial 133Xenon clearance method using a 10-detector-equipment. Intravenous administration of 6-10 g Piracetam caused an overall increase of the fast component of rCBF after 30 minutes corresponding to blood flow in the grey matter, of 10.0 ml/100 g/min (18.9%). The slow component of rCBF corresponding to the cerebral blood flow in the white matter remained unchanged. The regional CBF was influenced to a varying degree, the areas marked by an insufficient blood supply showing a mean increase by 17.5% and the areas marked by normal basic values showing a mean increase by 6.3%. This difference in alteration is statistically significant (p is less than 0.005) comparing the differences as %. The increase of cerebral blood flow in grey matter is interpreted as a secondary effect after activation of central nervous system metabolism by Piracetam.

Using Indium-113m and the Gamma Retina V (Fucks-Knipping Camera), the minimal cardiac transit times (MTTs) were measured radiocardiographically from the right auricle to the aortic root. This analysis served to determine the relation between stroke volume and the segment volume of the part of circulation between the right auricle and the aortic root. In 39 patients with myocardial insufficiency of different clinical degree the effectiveness of digitalization was, up to a period of 5 years, measured by means of the volume relation mentioned above. The following conclusions can be drawn from the results: digitalization of patients with myocardial insufficiency leads to an improvement of the impaired relation of central volumes. In patients with diminished cardiac reserve the improvement is drastic and often results in a nearly complete normalization. The data remain constant during therapy even for an observation period of 5 years. Digitalization of patients with congestive heart failure only leads to a partial improvement. In contrast to patients with diminished cardiac reserve this effect is temporary. The different behaviour of the relation between stroke volume and segment volume in patients with diminished cardiac reserve and congestive heart failure under prolonged administration of digitalis points to the necessity of treatment with digitalis in the early stage of myocardial disease.

On 23 investigations in dogs the 133xenon eluation method was compared with the bloody measurement of the renal blood supply. The most favourable correlation presents the measurement of the initial decrease of the curves with r = 0.827 and y = 0.889x + 53.3, besides the modified hight-surface-method. Possibilities of error exist especially by the recirculation of xenon and the influence on the blood supply by the xenon-injection.

Methods and results of the measuring of the rumen volume and the passage rate as well as the dependence of the production of volatile fatty acids on the parameters mentioned are described. The correlative relations between rumen volume on the one hand and feed passage on the other hand to the production quotas are investigated. Passage rates and rumen volumes were determined with the help of the isotope dilution method. In the course of reproduction rumen volumes of 7.81, 6.41, 8.91, 7.11 in experiment 1 and 5.41, 5.81, 9.51 and 4.71 in experiment 2 were measured in the sequence early stage of gestation, late stage of gestation, lactation and the period between pregnancies. The average total production of volatile fatty acids within 12 hours amounted to 475 mmol, 265 mmol, 313 mmol and 351 mmol in experiment 1 and 155 mmol, 175 mmol, 271 mmol and 144 mmol in experiment 2 in the same sequence. The average passage duration of the feed through the digestive tract of the ewes was 32.4 h in experiment 1 and 33.6 h in experiment 2. The relatively high feed intake of the ewes resulted in a short passage duration and could be a cause of the low production quotas of the volatile fatty acids.

A survey of the range and progress of nuclear medicine procedures is presented and the accuracy of the modalities is described. The priority in nuclear medicine diagnosis has shifted from proof of the non-functioning nodule to localization of biochemical lesions with the aid of new bioindicators and single photon and positron emission computer tomography. Diagnosis has extended to subcellular regions with the introduction of immunoscintigraphy as well as enzyme and receptor scintigraphy. This is a new dimension to which Swiss nuclear medicine specialists have contributed a great deal.

1971 Sorbie et al. described a simple 57Co-excretion test (16) as an aid in the diagnosis of iron deficiency anemia. The authors found that renal excretion of a tracer dosis of 0,5 muCi 57CoCl2 was significantly elevated in patients with iron deficiency anemia (31% of the administered dose in 24 hours' urine) as compared with the controls (18%). Between 1972-1974 we performed the 57Co-excretion test in 29 patients with different kind of anemia and in 10 healthy volunteers. The test was modified by measurement of the serum activity 1, 2, 3, 7, 11 and 24 hours after the oral administration of the test dosis. In all anemias as well as in the control group we found the maximum of serum activity three hours after the oral administration of the tracer. The three hours serum activity was elevated only in patients with iron deficiency anemia (5,53%/1 serum) as compared with the control group (1,92%/1) and renal, tumor and infectious anemia (1,20%/1). p less than 0,001. The 57Co excretion was moderately elevated in most of the patients with iron dificiency anemia (average 31,5% 57Co-activity in 24 hours' urine) in comparison to the healthy controls (average 25,30%). Contrary to the results obtained by Sorbie et al. we found a wide range of fluctuation of the Co-excretion test in each group of patients with a poor statistical significance of p greater than 0,005.

Extravascular lung water is estimated in vivo from indicator dilution curves of diffusible and non-diffusible tracers utilizing their different transit times as they pass the lung microvessels. 131I-antipyrine as the diffusible and 99mTc-HSA as the non-diffusible tracer were injected simultaneously, using a pneumatic injector. Indices for rELW/V and rELW/F were calculated using programs previously published, and gave numerical values for the presence and intensity of pulmonary interstitial oedema. Inaccuracies due to sequential inputs are avoided. 131I-antipyrine has a more convenient pulmonary interstitial oedema. Inaccuracies due to sequential inputs are avoided. 131I-antipyrine has a more convenient shelflife and can therefore serve for emergency and follow-up examinations. The results do not differ significantly form those with 123I-antipyrine, and the higher radiation burden is tolerable. A mobile set-up for bed-side measurements is described.