[Pharmacokinetic research and the ultrastructural changes in the lungs of white rats after aerosol administration of a high dose of kanamycin sulfate]. / Farmakokinetichni prouchvaniia i ultrastrukturni promeni na belite drobove na beli plukhove sled aerozolno prilagane na visoka doza kanamitsinov sulfat.

Studied is kanamycin sulphate "Pharmachem", substance with activity 750 UI/mg, applied on albino rats in the form of water aerosol. The experiments are carried out in aerosol camera of flow-dynamic type with capacity 450 l at exchange of the air 60 l/min with aerosol apparatus of pneumatic type, for 10 min and staying in the aerosol cloud another 10 min. It is established that the kanamycin sulphate, after aerosol application on albino rats in dose of 50000 UI/m3, passes in the blood and is found out in the serum yet in the first hour (1.75 +/- 0.23 mg/cm3 serum). The maximal quantities of antibiotic are established in the first hour in the lungs (52.1 +/- 11.4 micrograms/g) and the antibiotic is detained in therapeutical concentrations for 240 h (0.1 +/- 0.03 micrograms/g). The content of the kanamycin in the kidneys is in the limits from 0.1 +/- 0.02 to 1.69 +/- 0.17 micrograms/g. At the electronic-microscopic tests of the lungs is observed hyperemia and destruction of the lamella corpuscles, which processes up to the 120th hour gradually calmed down.

[Effect of the bacterial count in the air on chickens and laying hens raised commercially]. / Vliianie na kolichestvoto bakterii vuv vuzdukha vurkhu pileta i kokoshki nosachki, otglezhdani pri promishleni usloviia.

Investigations were carried out to establish the amount of bacteria in the air on the premises for raising young birds and laying hans as well as in the respiration organs of the birds. Attempts were made to lower the microbism on the premises through the aerosol spray of Lugol solution. It was found that under industrial conditions there existed a rising trend with microbism both on the premises and in the respiratory organs of the birds, parallel to the advance in age which contributed to the enhancement of mortality rate and the drop of productivity. The use of Lugol solution in the form of spray was shown to produce a favourable effect on the health and productivity of birds.

[A pneumatic-type aerosol apparatus for veterinary uses]. / Aerozolen aparat ot pnevmatichen tip za veterinarni tseli.

Described is a Bulgarian aerosol apparatus of pneumatic type with an original nozzle and way to maintain permanent pressure. The apparatus is supplied with a set of 7 nozzles of a varying dia and is intended for universal dispersion of veterinary preparations and vaccines in aerosol form in view of their dosing. It makes it possible to maintain the desired concentration of the preparation sprayed for several minutes. The pneumatic type is advantageous for a number of reasons over other other apparatuses of similar design. It is simply constructed, easily put to action, is stable and cheap, and can be sterilized.

[Newcastle disease virus carrier state following the aerosol immunization of chickens against the disease using different doses of La Sota vaccine]. / Virusnositelstvo na Niukiasulskiia virus sled aerozolna imunizatsiia na pileta sreshtu psevdochuma s razlichni dozi vaksina La Sota.

Six experiments were carried out with aerosol immunization, using various doses of the La Sota vaccine against Newcastle disease, and a control infection with massive amounts of the viscerotropic virus strain Pavlikeni to evaluate the duration of carrying the Newcastle disease virus. The aerosol vaccination of the birds was performed in laboratory conditions in an aerosol chamber of a flow-dynamic type of 450 l. The amount of the virus in the aerosol was determined through virologic investigations of samples taken by means of a glass capillary impinger. It was found that a short-term carrier state set in up to the 9th-10th day with the La Sota strain, regardless of the dose used and the age of the birds. The persistence of the velogenic virus in the organs of birds depended on the amount of vaccine used and the age of the birds. With 2-month-old chickens at optimal dosing of the vaccine resistance could be built up to the infection. When low doses of the vaccine were used with 10-day-old chicks as well as when over-dosing occurred the strain Pavlikeni could be recovered from the organs in the course of 3 to 7 days.

[Newcastle disease virus in tissue cultures studied by an immunofluorescence method]. / Prouchvane na Niukiasulskiia virus v tukanni kulturi s imunofluorestsentniia metod.

Studied was the opportunity to demonstrate the Newcastle Disease Virus in tissue cultures with the employment of an immunofluorescence method. The development was followed up of four strains--the vaccinal ones Hitchner B1, La Sota, and Komarov and the velogenic one, Texas GB, using chick fibroblasts. It was found that the velogenic strain cumulated earlier and more intensely than the vaccinal ones, where the virus was seen to explicitly locate perivascularly. The most dependable demonstration of the virus proved possible with the velogenic strain at the 4th hour, and with the vaccinal strains--from the 6 th to the 10 th hour following the infection of the cultures. The virus antigen cumulated progressively, and with the velogenic strain it was accompanied with the production of a cytopathic effect which destroyed the cells by the 20th hour; with the vaccinal strains the cells remained intact up to the 48th hour following infection.

[Newcastle disease virus carrier state after aerosol vaccination against the disease in chickens of various ages]. / Virusonositelstvo ne Niukiasulskiia virus sled aerozolna vaksinatsiia sershtu psevdochuma pri pileta na razlichna vuzrast.

Studied was the carrier status with the Newcastle disease virus in experiments with a total of 665 birds at the age of 10 days, one month, and two months following an aerosol vaccination with a La Sota strain vaccine as well as the possibility to isolate the velogenic strain Texas GB after control infection of 10-day-old and one-month-old birds. Established was a short-term carrier status with the La Sota strain in the organs of birds up to the 6th-9th day following the aerosol vaccination. In an experiment with month-old birds originating from parental flocks immunized against Newcastle disease the La Sota virus was isolated also from the brain up to the sixth day. The resistance of birds to the infection was demonstrated at the aerosol immunization of 10-day-old and month-old- birds followed by challenging the birds with high doses of the velogenic virus strain Texas GB.

[Stability of Aujezky's disease virus strain MK25 in an aerosol]. / Stabilnost na virusa na bolestta na Aueski--shtam MK25 v aerozol.

Twenty-two tests were carried out to evaluate the stability of the virus of Aujeszky's disease in aerosol. Use was made of a aerosol chamber of a flow dynamic type, 450 l, of 60 l/min of passing air, 5 min. exposure, 80-100 per cent relative humidity, and temperature range of 14-21.2 degrees C. The size of aerosol particles surpassed 5 micron, and changed according to the composition of the dilution medium of the vaccine. The aerosol was sampled via impinger at the rate of air flow of 5.2 l/min. Tested were the stabilizing properties of 2% glycerin, 10% pepton, 0.8-2.0% saccharose, 2% gelatin, and 5% skimmed milk added to the extender consisting of a 0.2 M phosphate buffer saline, pH 7, specifically for the MK25 strain of the Aujeszky's disease virus in a dispersed status. Highest stability, reaching 11.2% survival rate of the virus in aerosol was recorded at the dispersion of the vaccine in a 0.2 M buffer saline with the addition of 10% pepton and 0.8% saccharose at pH 7.