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Biomedical subjects

S E Olsson

Publications and source records attributed to S E Olsson.

At least 73 records · Page 4Linked to original sources
PubMed1978

Skeletal lesions in the broiler, with special reference to dyschondroplasia (osteochondrosis). Pathology, frequency and clinical significance in two strains of birds on high and low energy feed.

The material consisted of 2,950 broilers of the variety Hybro Compact of two lines. An equal number of birds of both lines were given either a high energy feed (H) or a low energy feed (L), containing all nutrients known to be required by broilers. During the first 3 weeks, H and L starter feeds were given and thereafter H and L finishing feeds. At 21, 35, and 45 days of age, the birds were weighed in groups, and feed conversion calculated. At 21 days of age, the frequency of crooked toes and swollen hocks was registered. Birds were taken from each group for necropsy at regular intervals. Both clinically normal birds and those with locomotor disturbances were selected for necropsy, including radiographic examination. With the exception of 240 birds, which were kept for a long-term study, the birds on the H feed were slaughtered at 42 days of age and the ones on the L feed at 49 days of age. The long-term birds were slaughtered at regular intervals, weighed, and necropsied. The last birds were slaughtered at 134 days of age. A large number of skeletal lesions were found. They were: Twisted legs, slipped tendons, crooked toes, bowing of the proximal tibia, dyschondroplasia at different sites, fracture of the fibula, deformity of the spine, deviated sternum (with breast blisters), arthritis, and osteomyelitis. Leg weakness was found to be almost synonymous with skeletal deformities. Other causes were rare. The normal development and morphology of the skeleton and the morphology of tibial dyschondroplasia were the same as those previously described in the turkey. Dyschondroplasia was found not only in the proximal tibia but also in the distal tibia, proximal tarsometatarsus, proximal and distal femur, and to some extent also in the costochondral junction. Tibial dyschondroplasia was more common in the birds on the H feed than in the birds on the L feed. Hence, tibial dyschondroplasia was correlated with rapid growth. The other skeletal lesions did not differ in incidence in the birds on the H and L feeds. It was postulated that greater difference in growth rate is necessary for a demonstration of a possible correlation between skeletal deformities and growth rate.

Animal Feed↗
PubMed1978

Normal and pathologic skeletal development in broiler and leghorn chickens. A comparative investigation.

Skeletal development of broilers of two lines of the Hybro Compact strain was compared to the skeletal development of leghorns. Environment, management, and feeds were identical for comparable groups of broilers and leghorns. Half of the broilers (representing both lines) and half of the leghorns were given a high energy feed, while the other half of the birds of both breeds were given a low energy feed. No great difference in feed conversion between broilers and leghorns was found. The broilers consumed more feed and increased their body weight and volume of the tibia almost twice as fast as the leghorns. The difference in longitudinal growth of the tibia of the birds of the two breeds was much less evident. Locomotor disturbances (leg weakness) were common in the broilers, and in the majority of the cases the problems were caused by skeletal deformities. The leghorns were almost completely free of skeletal deformities and had no locomotor disturbances. Likewise, dyschondroplasia was not found in the leghorns, while it was common in the broilers. Most of the skeletal deformities in the broilers were explained as the result of mechanic-traumatic factors, acting on a rapidly remodeling skeleton, apparently of insufficient strength for the heavy body weight. Dyschondroplasia, on the other hand, was considered to be caused by a generalized factor governing growth. Basic histologic differences between broilers and leghorns already at an age of 7 days supported this theory. It was concluded that both leg deformities and dyschondroplasia in the broiler are man made problems, caused by genetic selection for characteristics of economic importance, without enough consideration to function and health of the animals.

Animal Feed↗
PubMed1976

Effects of somatostatin on the biosynthesis and release of insulin from isolated pancreatic islets.

The glucose-stimulated insulin release of pancreatic islets isolated either from normal mice or from mice with the obese-hyperglycemic syndrome (genotype ob/ob) was inhibited by somatostatin in the concentration range 10(-2) - 10(-4) mM. Islets prepared from the obese-hyperglycemic mice appeared most sensitive and there was a strong inhibitory action on the insulin release irrespective of whether the islets were exposed to somatostatin directly after isolation or after five days in tissue culture. There was, however, no effect of somatostatin on the glucose-stimulated insulin biosynthesis of the mouse islets. Neither was there an effect on the insulin biosynthesis of isolated islets from three days old rats, despite a previous report to the contrary. It is concluded that somatostatin does not affect the insulin biosynthesis of isolated islets at concentrations which inhibit insulin release.

Animals↗
PubMed1975

Growth and mitotic rate of the proximal tibial epiphyseal plate in hypophysectomized rats given estradiol and human growth hormone.

Hypophysectomized female immature albino rats were injected with HGH, HGH and estradiol, or estradiol solely. Some animals were left as controls. All animals were killed on day 3 or 5 of the experiment. One hour before sacrifice, the animals were flash labelled with tritiated thymidine. The following parameters were registered: labelling index, thickness of the growth plate, weight gain, and size of the uterus. The following conclusions were drawn. 1. Estradiol decreases the mitotic rate and retards growth of the epiphyseal cartilage. Its effect on the mitotic rate is more pronounced than its effect on the thickness of the tibial epiphyseal plate. 2. HGH increases the mitotic rate and promotes growth of the epiphyseal cartilage. Its effect on the thickness of the epiphyseal plate is more pronounced than its effect on the mitotic rate. 3. Estradiol decreases the mitotic rate even in the presence of HGH. 4. Estradiol seems to have a direct effect on mitosis of the chondrocytes.

Animals↗
PubMed1975

Growth and remodeling of the hip joint and proximal femur in adolescent dogs. A scintimetric investigation with special reference to hip dysplasia and estradiol induced changes.

The uptake of 85Sr was shown to be higher in dysplastic hip joints than in normal joints of adolescent dogs. This was interpreted as a sign of increased remodeling. In contrast, the uptake of 85Sr in the growth plate and metaphysis of the proximal femur was lower in dogs with hip dysplasia than in dogs with normal hip joints. This was interpreted as a sign of retarded growth of the proximal femur (more advanced skeletal maturation). Greyhounds of bitches, which were injected with estradiol during pregnancy, also showed retarded growth of the proximal femur. This was interpreted as a late effect of estradiol.

Animals↗
PubMed1975

Blood plasma levels of progesterone and oestradiol in the dog during the oestrous cycle and pregnancy.

Plasma oestradiol and progesterone levels were studied in German Shepherd and Greyhound bitches during the normal oestrous cycle, pregnancy and at parturition. The mean oestradiol level increased from approximately 7 to 13 pg/ml during the fifth week before onset of oestrus. Oestradiol stayed at this level until pro oestrus which was characterized by a steady increase to a mean peak level of about 30 pg/ml 5-6 days before oestrus. At the start of oestrus the level was approximately 12 pg/ml. A level between 10-15 pg/ml was kept during the following 10 weeks whether or not the bitch was pregnant and no change occurred at parturition. The mean progesterone level was found to be very low, around or under 1 ng/ml, until 1-4 days after the oestradiol peak after which the level gradually increased to around 10 ng/ml at the start of oestrus. During oestrus and metoestrus or pregnancy the pattern was inconsistent. In some bitches the level gradually increased during 3-4 weeks and reached a peak value of 30-50 ng/ml. The level then gradually decreased during 5-6 weeks. During the first 5 weeks of the same period progesterone in other bitches fluctuated between similar maximum levels and extremely low levels. After the fifth week the pattern was the same for all bitches. In the pregnant bitches there was a significant drop of the progesterone level at parturition. The data suggest that the dog is not an ideal test animal for steroids synthetized for use in man.

Animals↗
PubMed1975

Plasma levels of estradiol and plasma protein binding of sex steroids in dogs. An investigation with special reference to development of hip dysplasia in growing individuals.

Peripheral plasma levels of estradiol were determined in 39 dogs of three breeds (Greyhound, German Shepherd, Golden Retriever). Blood samples were collected weekly from 3 weeks up to 17--21 weeks of age. The pups from all three breeds had mean levels of estradiol varying between 4--8 pg/ml. The lowest levels were found in pups which developed hip dysplasia. There was a significant difference (0.01 less than p less than 0.005) between the estradiol levels of German Shepherd pups with normal and dysplastic hip joints. In female Greyhounds, the peripheral plasma levels of estradiol were examined from 17 weeks of age through the first heat. No increase of the estradiol level was seen with increasing age. The ability of dog plasma to bind dihydrotestosterone (DHT) and estradiol was examined in three dogs. It was found that there are at least three types of binding components for DHT: one with high affinity and extremely low capacity, which is heat labile, another which is also heat labile but has a high capacity and low affinity, and a third which appears to be albumin. Estrogen administration to the three dogs lowered the binding of DHT. It was concluded that it is most unlikely that hyperestrogenism is an etiologic factor in canine hip dysplasia. Unphysiologically high doses of estradiol have been used for experimental induction of hip dysplasia. There is a possibility that the levels of plasma proteins, which bind steroids, could be of importance for the etiology of hip dysplasia. A low plasma level of estradiol could be biologically highly significant if there is a low level of a specific binding protein.

Animals↗
PubMed1975

Acute pulmonary edema and seizures in hunting dogs.

The clinical and radiographic appearance of acute pulmonary edema in three hunting dogs are reported. The etiology is discussed. The conclusion was drawn that the cause of pulmonary edema was probably neurogenic, probably induced by hypoglycemia. Prevention and treatment are discussed.

Acute Disease↗
PubMed1975

Growth and remodeling of bone. An investigation in chicken with special reference to the mechanism of bone resorption.

Bone resorption was studied in chicken by means of histologic and microradiographic examination after intravital injections of three boneseeking fluorochromes. The fluorochromes were injected at intervals from 36 hours to 5 days, and the chicken were killed at 36 hours to 10 days after injection of the third fluorochrome. Signs of osteolysis, such as enlarged osteocyte lacunae surrounded by a metachromatic zone in toluidine blue stained sections, and confluence of osteocyte lacunae in microradiographs, were compared with the fluorochrome labelling pattern. There was no correlation between the histologic findings of osteolysis and the fluorochrome resorption pattern which indicated that existence of so-called bone flow. In the "haversian systems" at midshaft level, the color pattern remained unchanged till resorption took place from the endosteal side. Osteoclasia seemed to be the dominant mode of resorption. The conclusion was drawn that bone flow does not exist in the tibiae of chicken.

Animals↗