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Biomedical subjects

K Loeffler

Publications and source records attributed to K Loeffler.

At least 19 recordsLinked to original sources
PubMed2003

Immunological effects of allopurinol in the treatment of experimental autoimmune uveitis (EAU) after onset of the disease.

PURPOSE: Allopurinol reduces oxidative tissue damage and exerts immunomodulating effects in the treatment of experimental autoimmune uveitis (EAU). However, the mechanism of the immunologic pathway remains unclear. In previous studies, treatment was started at the time of immunization. Therefore, whether allopurinol prevents the onset of the disease (i.e., acts in a protective manner) is not known. METHODS: Sixteen male Lewis rats were used: 6 EAU without therapy [control]; 4 EAU with allopurinol treatment starting 7 days after immunization [AL7]; and 6 EAU with allopurinol treatment starting 11 days after immunization [AL11]. Their sera were tested against Western blots of sodium dodecyl sulfate-polyacrylamide gel electrophoresis of retinal proteins. Based on digital image analysis, analysis of discriminance was done. RESULTS: There were significant immunomodulating effects in both therapy groups (Wilks' lambda 0.001, P < 0.008) compared to controls. However, the effects were more pronounced in the AL7 group, where peak intensities and the number of peaks were markedly more reduced. CONCLUSIONS: Immunomodulating effects of allopurinol can be detected even if the therapy starts after the onset of the disease. Thus allopurinol strongly influences the immunologic mechanism in this model of autoimmune disease. In view of its minimal side effects, the drug could be a promising alternative for the therapy and prophylaxis of uveitis and other autoimmune diseases.

Adjuvants, Immunologic↗
PubMed2001

Topography, structure and function of the patella and the patelloid in marsupials.

The patella is a sesamoid bone that is found in most mammals and is regularly located in the insertion tendon of the quadriceps femoris muscle. Up to now, only a little has been known about the topography, structure and function of the patella in marsupials. Therefore the stifles of 61 marsupials of 30 different species were studied by radiography, necropsy and light microscopy. It was found that only the family of bandicoots (Peramelidae) possessed a typical patella. The other species revealed a patelloid consisting of fibrocartilage. The structure of the patelloid revealed common characteristic features in the following families of marsupials: (1) Dasyuridae, Phalangeridae. Pseudocheriidae, and Potoroidae; (2) Burramyidae; (3) Phascolarctidae, Vombatidae, and Dendrolagus; and (4) Superfamily Macropodoidea (except Dendrolagus and Potoroidae). Our results imply that the degree of differentiation in the fibrocartilage of the patelloid was strongly correlated to the mechanical forces acting on the patelloid which are a result of the specific kind of locomotion and the way of life. Generally the bony patella does not belong to the phylogenetic programme of the marsupials--with the exception of the bandicoots which are very closely related to the subclass of placental mammals (Eutheria).

Animals↗
PubMed2000

[Immunological effect of systemically administered allopurinol in experimental autoimmune uveitis].

PURPOSE: Allopurinol shows beneficial effects in the systemic treatment of lens-induced uveitis. This is believed to be due to the reduction of oxidative tissue damage via a dose-dependent free radical scavenging ability and an immunomodulating effect. The purpose of this study was to investigate the immunological effects in experimental autoimmune uveitis after systemic treatment with allopurinol (AL) and steroids (STER). METHODS: 31 male Lewis rats were immunized with crude retinal extract, Freund's Adjuvans and pertussis toxin. The rats were divided into four groups: healthy rats (BASIS, n = 3), experimental autoimmune-uveitis without therapy (EAU, n = 9), 50 mg/kg bw. allopurinol i.v. (ALSYS, n = 9), and 7.5 mg/kg bw. methylprednisolone i.v. (STSYS, n = 10). ALSYS and STSYS received five intravenous injections during the 2 weeks immunization period. The rats' sera were tested against Western Blots (WB) of electrophoretic separations of retinal proteins. Based on digital image analysis, an analysis of discriminance was performed. RESULTS: The multivariate analysis of discriminance revealed a significance difference between the WBs of ALSYS and STSYS (p < 0.01) compared to EAU without therapy. The number and intensity of peaks in WBs were strongly reduced in the ALSYS group compared to EAU. CONCLUSION: AL revealed a strong immunomodulating effect in the treatment of experimental autoimmune uveitis that is markedly stronger than that of steroids. Together with the antioxidative effect of allopurinol known from previous studies, this drug could be a new promising therapeutic approach in the treatment of uveitis.

Allopurinol↗
PubMed1997

[Comparison of the histologic structure of the compact bone of the long hollow bones of mouse, hamster, rat, guinea pig, rabbit, cat, and dog during development].

This paper reports on histological examinations of the diaphyseal structure of the long bones (humerus, radius, ulna, os femoris and tibia) of mouse, hamster, rat, guinea pig, rabbit, cat, and dog using six animals in three different age groups. There are considerable differences in structure between the species. The results show that with increasing height in the evolution of the species and period of life, as well as advancing age, the differentiation and complexity of bone structures increases. The differences in structure between the localization of bones within the individual species are not considerable. The species comparison results in great similarities between the bone structures of each of mouse and hamster, of rat and guinea pig, as well as of cat and dog. The bone structure of the animals examined becomes more similar to the human structure from mouse, hamster, rat, guinea pig, rabbit, and cat to dog.

Animals↗
PubMed1996

[Scoliosis, lordosis and kyphosis in breeding rabbits].

Vertebral columns of female and male breeding rabbits, kept in conventional cages or in a group housing system, were investigated by spot checks anatomically and radiographically in regard to deformations of the vertebral column. It should be proved, whether depending on the housing system and the opportunity of locomotion the male and female rabbits get deformations of the vertebral column. The observations show, that the bucks had no deformations, whereas the does had. It became evident, that frequence and degree of deformation were dependent on the cage size. It provokes deformations by "flat sitting" as well as the systemic hypoplasia of bony tissue caused by deficiency of locomotion. Reproduction provokes deformations of the vertebral column, too, causing alterations in the static-dynamic forces of trunk construction as well as a high need and metabolism of calcium. The causing factors and the relevance of animal protection are discussed.

Animals↗
PubMed1996

[Histological study of cartilage channels in the epiphyseal cartilage of young dogs and their relationship to that of osteochondrosis dissecans in the most frequently affected locations].

Osteochondrosis is a disease occurring in many species of domestic animals. There are different factors like genetic predisposition, housing and feeding, trauma and stress, which are thought to be the causes or part of the causes of the disease. There have been studies about swine, finding a connection between cartilage channels in juvenile epiphyseal cartilage and the development of osteochondrosis. The aim of the study was to find out whether those connections exist in dogs as well. Special interest has been laid upon the localisation, the contents and the surroundings of cartilage channels as well as their relationship to the localisation of osteochondrosis. Joint surfaces, that are most often subject to osteochondrosis in the dog, have been examined macroscopically and histologically, e.g. the caput humeri, the medial part of the humeral condyle, the lateral condyle of the os femoris, the cochlea tibiae and the trochlea tali of 31 dogs at the age of three days to nine months. According to this examination cartilage channels can disturb the process of ossification of cartilage in the secondary centre of ossification, causing a thickening of cartilage layers. These changes can often be seen in locations, where osteochondrosis usually develops, especially in the caput humeri. Altogether they could be located more often in male animals and large breeds than in female animals and small breeds. To a certain degree these changes can be considered as normal in the development and growth of a young dog, but combined with other factors like trauma or stress, they may play a favoring role in the pathogenesis of osteochondrosis as well.

Animals↗
PubMed1995

Antihypertensive effect of oral nitrite uptake in the spontaneously hypertensive rat.

The lower blood pressure of vegetarians might partly be due to the high dietary load with nitrate which--to a certain extent--is further reduced to nitrite and finally to nitric oxide. To test this hypothesis, spontaneously hypertensive rats received drinking water containing 0, 25, 50 or 100 mmol/l NO2 during 56 days. Food was offered ad libitum or was restricted by 20% (pair-feeding) to simulate the lower energy consumption of vegetarians. Blood pressure, which was monitored at regular intervals, was lowered in a dose-dependent manner by nitrite. This effect was reversible and could not be enhanced by energy restriction. In volunteers plasma nitrate levels increased by a factor of 8 to 32 following the ingestion of a nitrate-rich meal, and mean methemoglobin concentrations increased from 1.2% to 2.4% indicating the endogenous formation of nitrite under these conditions.

Adult↗
PubMed1994

[Horse controls--animal welfare in equine sports].

In the course of ten horse-shows 248 horses were submitted to a short veterinary examination in the course of the horse controls that were introduced in 1991. In 143 horses (57.6%) animal cruelty preventive deficiencies were found. The results of the horse controls are compared to previous results and discussed from the point of view of animal protection.

Animal Welfare↗
PubMed1993

[Pain and fear in animals].

Pain and fear are feelings of reluctance, which result in a behaviour of avoidance. They are protective mechanisms and are only partly approachable to the quantification with natural scientific methods. It will pointed to the central role of the diencephalon, limbic system and the cerebral cortex concerning the processing and valuation of mental state. The recognition of clinical symptoms and precise behavioural observations are an essential aid to assess the state of pain and fear in animals.

Animal Welfare↗
PubMed1992

[Behavioral studies of piglets and rabbits with special consideration of necessary supplies and avoidance of injury].

After introducing remarks on the meaning of the ethology of farm animals about the evaluation of housing systems the own examinations about piglets in the rearing period and about housing systems of rabbits held in groups respectively will be demonstrated. By these examinations choice experiments have proved true. For estimating and evaluating the ethological experimental results the concept of the meeting of requirements and avoidance of damage is an important point. The animals requirement can be found out in reference systems. Those investigated results are used as guiding-line for the evaluation of the dates found under practical conditions. The merits of Tschanz concerning the ethology of farm animals will be appreciated.

Animal Husbandry↗
PubMed1991

[The fat content in the muscles of three selected lines of German Landrace swine. Effects of graded feeding intensity on muscle fattening. Muscle fat content in relation to parameters of body fat deposits].

Investigations on muscle fat content and intramuscular adipose tissue pattern of 51 male castrated pigs were performed. For each body 4 muscles were collected after slaughter. Breeding lines of swine (German Landrace) had been selected through 8 generations for high ("E(+)-Line") and low ("E(-)-Line") levels of NADPH-generating dehydrogenases including a control group without selection. 42 animals were kept under feeding experiments of various energy levels from 60 kg up to 100 kg body mass. Additionally, out of control line 5 piglets (25 kg) and 4 hogs (135 kg) were examined. Data of ether-extracted total fat content versus data of fat marbling planimetry correlated well with r = 0.9. The average degrees of muscle fattening were: m. semispinalis capitis (11%) much much greater than m. psoas major (1.8%) greater than m. semimembranosus (1.7%) greater than m. long thoracis (1.3%). The specific internal relation of muscle fattening with respect to the collected samples was calculated as r = 0.8. Intramuscular fat showed the tendency to increase with higher levels of dietary energy. The E(+)-Line showed higher (16%) muscle fattening than the E(-)-Line. The control group, however, showed 44% higher levels than the E(+)-Line. So, the results of that K degree-Line could not serve as baseline for interpretations. The criteria of thickness and harmony of marbling scores were used to make statements of meat quality: The samples of m. psoas major and E(+)-Line reached the best, the samples of m. semispinalis capitis and the K degree-Line reached the least values.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1991

[The nature of the dog--a contribution to the keeping and breeding of so-called fighting dogs].

The behavioural repertoire of dogs derives from that of the wolf. But there are distinct race-specific differences which go back to the man's breeding influence in the course of domestication to develop special qualities in dogs. Today, dog keeping no longer corresponds to these qualities of dogs in many ways. We refer to the problems resulting from this and man's responsibility for the establishment of a man-dog relationship that is functional and responds to the dog's character. The abuse of certain dog behaviour by man has to be pursued consistently. In the same way we must also take care of an unforced integration of dogs into our society.

Aggression↗
PubMed1990

[Pain and suffering in animals].

The perception of pain stimuli by nociceptors and their conduction to the diencephalon are approximately identical processes in higher animals and in man. There are however differences between man and animal as well as between the species of animals concerning mental processing and assessing of pain. The importance of fear must be taken into regard. At the moment a scientific assessment of pain and suffering in animals is not possible.

Animal Welfare↗
PubMed1990

[The adaptation of the morphometric parameters of fat cell size for the purposes of animal science research. 2. Cellularity of subcutaneous adipose tissue of different swine breeds influenced by graduated feed levels and in relation to metabolic data and parameters of body fat degeneration].

Measurements of morphological and biochemical parameters in subcutaneous adipose tissue as well as investigations of energy metabolism and fat deposition of 89 male castrated pigs were performed. Breeding lines of swine (German Landrace) had been selected through 8 generations for high ("E(+)-Line") and low ("E(-)-Line") levels of NADPH-generating dehydrogenases. A control group ("K.") without selection was closely paralleled. For 21 days the animals were kept under feeding experiments within 2 sectors of growing period (67 kg, 85 kg body mass), and biopsies of backfat were examined subsequently. The inner layer of subcutaneous adipose tissue showed constantly bigger fat cells than the outer layer. The fat cell size increased generally with fattening and body mass respectively. The cellularity of adipose tissue was dependent significantly on the percentage of the very small fat cells measured up to 30 microns diameter (= "PKF30"). The breeding lines differed slightly with respect to their cellularity: The inner layer showed the gradation E+ greater than K. greater than E- concerning fat cell volumes and fat cell surfaces respectively. The PKF30 correlated significantly with food energy level as well as with the respirationally examined protein retention, particularly in inner layers of younger animals. Relations to the fat deposition (examined respirationally or with the D2O-Method and after slaughter respectively) were recognized, not showing validity for all cases. The parameters of lipogenic activity tested by tissue slice preparations and homogenates respectively correlated negatively with average fat cell size.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1990

[The suitability of morphometric parameters of fat cell size for the purposes of animal science research. 1. Cellularity of swine subcutaneous adipose tissue influenced by different fattening ages and graded feed levels].

The cellularity of subcutaneous adipose tissue of 108 male castrated pigs (German Landrace) was investigated. The tissue was taken bioptically under anesthetic conditions. The outer and the inner layer of backfat were examined separately, fresh unfixed tissue slices floating in Ringer solution were subjected to microscopic measurements of adipocyte diameters. The animals were kept in feeding experiments, 3 and 2 sectors respectively of growing period were examined (40 kg; 66 kg, 88 kg body mass) divided into 6 and 4 feeding levels respectively for 21 days (0.4; 0.6/0.8; 1.0; 1.2; 1.4 MJ metabolic energy per kg body mass0.75 per day). The inner layer of backfat showed bigger fat cells compared to the outer layer. The average fat cell size was greater for the older and heavier than for the younger animals. The gradation of food administration resulted not in a straight parallel rise in fat cell size but in an effective consequence with respect to the distribution frequency of the dates: The higher the food energy level, the more the accumulation of small fat cells from 10 til 30 microns diameter. These cell fractions succeeded in being signified as typical and important closed population. Other authors also had described these particular cells, i.e. "fat cell clusters" and "VSFC" (= very small fat cells) respectively. An external use of the dates for computer simulation programs resulted in success and manifested the independently gained conclusions. The examinations were performed by support of different branches of literature and the results had to be discussed in front of a wide background of known connections.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1989

[Ethical demands in animal production].

Since the second world war, particularly within the last twenty years the structure of agriculture has been changed dramatically by intensifying, specialization and rationalization of every aspect of production methods. This has led to a severe change in the human-animal relationship. Large numbers cause alienation of man from the farm animals confided to him. Extremely high pressure of performance and mechanization of livestock husbandry often overstress the adaptability of the animals. It is to be expected that introduction of new methods of biotechnology will increase this process. The problems caused by this development necessitate to revise the management of animal production and husbandry, judgement to be based on ethical criterions. Farm animals are to be recognized and treated as creatures again. But in the context of livestock husbandry human-human relations are to be reconsidered under ethical aspects, too. In doing so, the scientific scale of values fails, determining correct or incorrect, true or false, whereas ethical judgement uses good or bad as criterions. The personal view is given, making use of some examples.

Agriculture↗