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Biomedical subjects

M Rommel

Publications and source records attributed to M Rommel.

At least 37 records · Page 2Linked to original sources
PubMed1989

Hemostatic alterations in pigs fed sublethal doses of Sarcocystis miescheriana.

Effects of non-lethal Sarcocystis miescheriana infections on the blood coagulation system were investigated. Nine pigs were inoculated orally with 2 X 10(5) sporocysts (Group A) and nine pigs (Group B) served as non-infected controls. Blood samples were taken from the vena jugularis externa every 2 or 3 days until 19 days post-infection (dpi). The following parameters were investigated: partial thromboplastin time (PTT), prothrombin time (PT), thrombin time (TT), thrombin coagulase time (TCT), fibrinogen (FIB), factor (F) VIII, F XI, F XII, antithrombin III (AT III), alpha 2 macroglobulin (alpha 2 MG), alpha 2 antiplasmin (alpha 2 AP), pre-kallikrein (PK), and the number of circulating thrombocytes. All infected pigs suffered from acute sarcocystiosis between 12 and 19 dpi. Clinical illness was most severe from 14 to 17 dpi. At this time, PTT and FIB increased, and TT and TCT decreased slightly. The activities of the clotting factors increased at 17 and 19 dpi. However, only F VIII activity was significantly higher in the infected pigs than in the controls at 17 and 19 dpi. PK was significantly lower in the infected pigs at 12, 14, and 17 dpi. Thrombocyte counts were reduced with the onset of the acute phase of illness and some pigs had marked thrombocytopenia. These results indicate low-grade disseminated intravascular coagulation (DIC) in the course of mild S. miescheriana infections in pigs.

Animals↗
PubMed1989

[Characterization of monoclonal antibodies to Sarcocystis spp].

Monoclonal antibodies have become powerful tools in immunology and biotechnology during the last decade. They are successfully used in a lot of fields in parasitology. This paper gives an overview of difficulties currently associated with immunodiagnosis of Sarcocystis infections and of the production and characterization of monoclonal antibodies for the investigation of problems that could not be solved by classical methods.

Animals↗
PubMed1989

Recent advances in the knowledge of the biology of the cyst-forming coccidia.

A review is given on recent knowledge of the genera Caryospora, Isospora, Cystoisospora, Hammondia, Toxoplasma, Besnoitia, Sarcocystis and Frenkelia. Caryospora hitherto considered to be monoxenous was found to have an optional intermediate host. Many Isospora species had to be transferred to the genus Cystoisospora because optional intermediate hosts were discovered. The obligatory two-host genus Hammondia could be confirmed to be distinct from the genus Toxoplasma. Even though the life cycles of Besnoitia wallacei and B. darlingi could be elucidated, the mode of transmission of B. besnoiti which is of considerable economic importance is still unknown. Since the discovery of the life cycle of the sarcosporidia in 1972 more than 600 papers have been published on this parasite. At present, 122 Sarcocystis species are named, and of 56 species both the definitive and intermediate hosts are known. It was shown that not only carnivorous and omnivorous mammals but also birds of prey, owls, and reptiles are definitive hosts of Sarcocystis species. the close relationship between the genera Sarcocystis and Frenkelia was confirmed by several investigators. Biology and Sarcocystis are of special interest. In the developmental cycle of most Sarcocystis species there are two schizogonic generations in endothelial cells of blood vessels, and in some species there is an additional asexual multiplication by endodyogeny in white blood cells. Some Sarcocystis species are highly pathogenic in non-immune intermediate hosts. Moreover, the sarcocysts which hitherto have been considered to be apathogenic may impair their hosts. In horses, they may cause myopathy, and in pigs, they have considerable influence on several parameters determining meat quality.

Animals↗
PubMed1989

[New anthelmintics and new treatment systems for the control of parasitic diseases of cattle in pastures].

Advanced knowledge of the epizootiology of parasitic gastroenteritis and the introduction of new anthelmintics and new application systems allow new strategies to control parasites of cattle on pastures. Ideally, parasitic gastro-enteritis is prevented by evasive grazing, i.e. the animals are driven every two weeks to new and not yet contaminated pastures, and the application of anthelmintics is not necessary. Midsummer treatment is most effective when combined with a move to non-contaminated pastures (Weybridge dose and move system). Following the introduction of the slow-release-devices, the prophylaxis of parasitic gastro-enteritis became much easier. The device, which is usually called bolus, is administered before turnout and it results in an effective reduction of the infection risk throughout the grazing season. Treatment following 3, 6 and 9 weeks after turnout prevents the development of dangerous numbers of infective larvae on the pasture in the second half of the grazing season. This system is known as Glasgow model. The pulse-release boluses follow the same principle and they offer the advantage of application at turnout and of releasing the anthelmintic in full doses at intervals. Treatment at the beginning of housing is only necessary when measures to prevent parasitic gastro-enteritis during the grazing season were not sufficient. All strategic measures reduce the risk of lung worm disease, but they do not prevent lung worm infection completely. On farms with a high lung worm pressure, additional control measures may be necessary. In areas with high risk of liver fluke infection, treatment in July may reduce pasture contamination.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

The effects of Sarcocystis miescheriana infections on blood enzymes and weight gain of stress-sensitive and stress-insensitive pigs.

The effects of mild Sarcocystis miescheriana infection on blood enzymes and body weight were compared in stress-sensitive (halothane positive) and in stress-insensitive (halothane negative) pigs. Ten halothane-positive pigs (Group A) and ten halothane-negative pigs (Group C) with a mean body weight of 36 kg were each inoculated orally with 50,000 sporocysts of S. miescheriana. Twelve halothane-positive pigs (Group B) and ten halothane-negative pigs (Group D) served as non-infected controls. Five days before infection (a.i.) and 58 days post infection (p.i.) all pigs were myostress challenged (creatine kinase test). During the whole period of the experiment (3 weeks a.i. to 13 weeks p.i.) body weights were determined and blood samples taken at weekly intervals. Creatine kinase (CK), aspartate aminotransferase (ASAT) and Sarcocystis antibody titres were determined. The infection induced slightly elevated temperatures (max. 42.8 degrees C) and transient reduced food intake during the 2nd and 3rd week p.i. The CK values of the infected pigs in Groups A and C increased from Day 28 p.i. onwards, and were significantly higher than those of the pigs of the non-infected controls (Days 35-77 p.i.). The ASAT values of the infected groups (A and C) increased from Day 21 p.i. onwards, and were significantly higher than those of the non-infected controls from Days 28-77 p.i. The myostress injection at 5 days a.i. (1st CK test) resulted in significantly higher CK and ASAT values in stress-sensitive pigs.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Effects of Sarcocystis miescheriana infection on carcass quality and on the water-binding capacity of the meat of halothane-tested fattening pigs.

Ten halothane-positive pigs (stress sensitive, group A) and ten halothane-negative pigs (stress insensitive, Group C) with a mean body weight of 36 kg were each inoculated orally with 50,000 sporocysts of Sarcocystis miescheriana. Twelve halthane-positive pigs (Group B) and ten halothane-negative pigs (Group D) served as non-infected controls. Thirteen weeks post infection (p.i.) the lean: fat ratios of the pigs of the infected groups A and C were lower (A, 1:0.41 +/- 0.09; C, 1:0.50 +/- 0.10) than those of the pigs of the non-infected groups B and D (B, 1:0.50 +/- 0.08; D, 1:0.55 +/- 0.08). The back-fat thickness, the fat thickness 'A' and the fat thickness 'B' were thinner in infected pigs than in non-infected pigs. The difference in Lendenstärkespeckquotient (Loin Fat Thickness Quotient) (LSQ) between infected and non-infected pigs was not statistically significant. The values of the water-holding capacity were lower in infected pigs than in non-infected pigs, the difference being statistically significant only in the halothane-negative groups (C, 0.45 +/- 0.02; D, 0.48 +/- 0.04). The water-absorbing capacity was significantly higher in the infected groups (A, 5.92 +/- 3.99%; B, 2.26 +/- 1.08%; C, 8.96 +/- 2.90%; D, 4.97 +/- 2.51%). In conclusion, it can be said that there was a slight tendency towards a better carcass quality and a better water-binding capacity in infected pigs, although this was combined with reduced growth rates.

Absorption↗
PubMed1987

The prevalence and identity of Sarcocystis in beef cattle in New Zealand.

Muscle tissue from the oesophagus and diaphragm of 500 beef cattle slaughtered in New Zealand was examined for Sarcocystis infection by microscopic examination of cysts isolated from muscle samples. All cattle were infected with Sarcocystis; based on light microscopy of cysts, 98% had thin-walled Sarcocystis cruzi cysts and 79.8% had thick-walled (Sarcocystis hirsuta/Sarcocystis hominis) cysts. Cysts were also collected for electron microscopy and transmission experiments. Thick-walled cysts could not be distinguished as S. hirsuta or S. hominis by light or electron microscopy. Thick-walled cysts were fed to three cats and one human volunteer; one cat shed sporocysts but not the human volunteer. Electron microscopy of the cysts revealed many features that have not been described previously.

Animals↗
PubMed1987

Effects of Sarcocystis miescheriana infection on carcass weight and meat quality of halothane-tested fattening pigs.

Ten halothane-positive pigs (Group A) and ten halothane-negative pigs (Group C) were each infected per os by 50,000 sporocysts of Sarcocystis miescheriana when they had reached a mean body weight of 36 kg. Twelve halothane-positive pigs (Group B) and ten halothane-negative pigs (Group D) served as non-infected controls. Thirteen weeks p.i. (post infection), the pigs were slaughtered and the carcass weights and the number of cystozoites in several muscles were determined. In addition, 11 parameters of meat quality were measured in Musculus longissimus dorsi (M.l.d.) and Musculus semimembranosus (M.s.): pH and temperature 30 min and 24 h p.m. (post mortem), electrical conductance 45 min, 60 min and 24 h p.m., colour brightness (FOP) and rigor values 30 min and 24 h p.m. Additionally, the AMP, ADP, ATP and lactate contents were determined in samples from the M.l.d. The mean carcass weights of the infected pigs (A: 79.9 +/- 6.9 kg; C: 76.3 +/- 11.6 kg) were lower than those of the pigs of the non-infected groups (B: 85.7 +/- 8.0 kg; D: 87.5 +/- 7.0 kg). The pH values at 24 h p.m. were significantly higher in the M.l.d. of infected pigs than in M.l.d. of non-infected pigs. Electrical conductance in the M.s. at 45 min p.m. was significantly higher in the halothane-negative infected pigs, but at 24 h p.m., the mean values of electrical conductance in the M.s. of the pigs of both infected groups were significantly lower than in the control groups. FOP values at 30 min p.m. were raised in the M.l.d. of the halothane-negative infected pigs, but at 24 h p.m., differences between infected and non-infected pigs could no longer be found. Mean rigor values were higher in the pigs of the infected groups at 24 h p.m., but the difference from the non-infected groups was not statistically significant. AMP was reduced only in the meat of halothane-positive infected pigs, while lactate was reduced in both infected groups. Using conventional methods for the determination of meat quality, the hypothesis of impaired meat quality in Sarcocystis-infected pigs could not be confirmed. The meat quality parameters investigated were, in part, better in infected pigs than in non-infected controls.

Adenosine Diphosphate↗
PubMed1985

Attempted immunization of swine against acute sarcocystosis using cystozoite-derived vaccines.

Low-dose Sarcocystis miescheriana infections have recently been shown to protect pigs against acute sarcocystosis. Because this protective immunity was short-lasting, an alternative immunization strategy was examined. Four experimental vaccines were prepared from S. miescheriana cystozoites and tested in 13 pigs. Two vaccines were prepared from intact organisms (live and formalin-fixed cystozoites) and 2 from subcellular cystozoite fractions (pellicle and protoplasm extracts). The live vaccine was injected intraperitoneally and the remainder were suspended in Freund's incomplete adjuvant and injected intramuscularly. An additional 5 pigs were injected with adjuvant or saline placebos and used as controls. Serum samples were collected regularly and tested in enzyme immunoassays for specific IgM and IgG antibodies. Low levels of IgM antibodies were detected after 8 days and elevated levels of IgG antibodies were detected after 22 days. The success of vaccination was tested 40 days after vaccination by lethal homologous challenge of each pig with 3 X 10(6) sporocysts. Despite the presence of specific antibodies at the time of challenge, all pigs died from acute sarcocystosis 12 days later. The cystozoite vaccines were therefore antigenic but not immunogenic and did not induce any protective immunity.

Animals↗