Problems in the use of radioactively labelled bacteria in experiments. 2. Quantitative method for the evaluation of pathogens in the calf lung by means of labelled bacteria after aerosol or intratracheal administration

By means of two aerosol apparatures radioactive labelled Pasteurella-multocida-germs were given to calves via a respiratory mask. Labelling of Pasteurellae was done internal by using special nutritive media with Fe-59 or P-32. In a period of 10-25 minutes 5 X 10(9)-10(10) labelled bacteria were given to the animals for inhalation. Another animal group was injected intratrachealy with the same quantity of labelled germs. Immediately after termination of germ application the animals were killed and dissected. After solution or homogenization, respectively of the total lung tissue radioactivity was determined by liquid-scintillation-counting (Fe-59) or Cerenkov-measurement (P-32), respectively. The activities recovered from lung homogenates rendered is possible to calculate the received amount of bacteria. 40-80% of germs would be recovered in the lung after application by intratracheal injection while only 1-7% could be recovered after individual aerosol application lasting for 15-25 minutes.     

Nutritional importance of pyrroloquinoline quinone

Mice fed a chemically defined diet devoid of pyrroloquinoline quinone (PQQ) grew poorly, failed to reproduce, and became osteolathyritic. Moreover, severely affected mice had friable skin, skin collagen that was readily extractable into neutral salt solutions, and decreased lysyl oxidase. The identification of functional defects in connective tissue and the growth retardation associated with PQQ deprivation suggest that PQQ plays a fundamental role as a growth factor or vitamin.     

Investigations on the blood composition of sows during the reproductive cycle

Contents: In the second experiment of the series, a total of 217 blood and plasma samples, collected throughout pregnancy and in the four different seasons of the year, were analysed for 23 different cellular, gaseous, and biochemical parameters. Significant changes were noted during the terminal stages of pregnancy in the differential leucocyte count (lymphocytes and neutrophilic granulocytes), during mid-pregnancy in the level of plasma proteins, and, in early gestation, in the glucose concentration of the blood. The erythrocyte volume and mean corpuscular haemoglobin as well as parameters associated with the acid-base balance produced interactions between seasonal and gestational effects, generally indicating the additivity of the heat load and the stress of the terminal stages of pregnancy.