[Follow-up ultrasonographic examinations in pregnant bitches - evaluation of frequency and significance of embryo resorption]. / Sonographische Verlaufsuntersuchungen an trächtigen Hündinnen - ein Beitrag zur Bedeutung der Fruchtresorption beim Hund.

OBJECTIVE: Follow-up ultrasonographic examinations in pregnant bitches to evaluate frequency and significance of embryo resorption. MATERIAL AND METHODS: In 39 Kangal bitches the number of gestational sacs was measured and vitality of embryos/fetuses was evaluated by real time ultrasonography daily from the 15th till the last day of gestation. RESULTS: Five bitches (12.8%) showed embryonic resorption and one of these bitches exhibited a complete resorption. Fetal death could be observed in four females and was related to a total loss of the litter. After the first evidence of embryonic death gestational sacs remained detectable for 8.6±0.5days. The number of embryos of bitches with (10.8±1.8) or without embryo resorption (8.2±2.1) was statistically significantly different (p<0.05). On the other hand there was no statistically significant difference within the number of embryos of bitches suffering fetal death and bitches without embryo resorption (8.2±2.1) (p>0.05). A relationship between litter size and gestational length could not be verified (r=0.15; p>0.05). CONCLUSION AND CLINICAL RELEVANCE: Due to these results the hypothesis is postulated that embryonic resorption is a kind of protective mechanism of the maternal organism against too large litter sizes.

The role of nitric oxide in the effects of ovarian steroids on spontaneous myometrial contractility in rats.

Forty ovariectomized rats were apportioned into one control and three experimental groups (n=10 each) to evaluate the role of nitric oxide in the effects of ovarian steroids on spontaneous myometrial contractility in rats. The control group (group Ov) received sesame oil once daily for 10 days, whereas rats in the experimental groups were treated with progesterone (2 mg/(rat day); group P), 17beta-estradiol (10 microg/(rat day); group E2), or progesterone and 17beta-estradiol together (group E2+P). The functionality of the arginine-nitric oxide synthase (NOS)-nitric oxide (NO) pathway in the uterine horns of sacrificed rats was evaluated in an isolated organ bath. L-Arginine, sodium nitroprusside (SNP) and 8-Br-cGMP decreased uterine contractile tension induced by electric field stimulation (EFS) in the Ov, P, and E2+P groups, but not in the E2 group. In addition, L-arginine was ineffective when applied together with a NOS inhibitor, L-nitro-N-arginine (L-NNA). The percentage of contractile inhibition was higher in the Ov and P groups compared to the E2+P group. Immunohistochemical evaluation revealed that expression of neuronal NOS (nNOS), inducible NOS (iNOS), and endothelial NOS (eNOS) in smooth muscles and nerve cells did not differ among the groups. Expression of nNOS and eNOS was strongly evident in the E2 and E2+P groups at both surface and glandular epithelium of the endometrium. iNOS expression was increased in surface epithelium of the E2 and E2+P groups. However, iNOS expression was only increased in glandular epithelial cells of the E2+P group. In conclusion, the L-arginine-NOS-NO pathway inhibits myometrial contractions via cGMP-dependent and -independent mechanisms, and while progesterone maintains the nitric oxide effects, estrogen prevents them. These results suggest that NOS does not mediate the effects of estrogen.

Lack of association between TNFalpha gene polymorphism at position -308 and risk of acute rheumatic fever in Turkish patients.

OBJECTIVE: Acute rheumatic fever (ARF) is a multisystem inflammatory disease process that follows nasopharyngeal infection caused by group A streptococcus (GAS) (Streptococcus pyogenes). Recent studies have demonstrated that allelic variations at the tumour necrosis factor alpha (TNFalpha) locus are involved in the nature of rheumatic diseases such as juvenile idiopathic arthritis and rheumatic heart disease. Thus, TNFalpha polymorphisms at -308 in ARF patients might be useful in contributing to identification of the primary factors associated with pathogenesis of ARF. METHODS: We performed a case-control association study between the common G/A promoter polymorphism at position -308 in the TNFalpha gene and ARF in Turkish patients, investigating whether this locus acts as a risk factor or has a modifying effect. RESULTS AND CONCLUSION: Previous studies have reported that TNFalpha plays a major role in the pathogenesis of a number of autoimmune and inflammatory diseases. Moreover, significantly elevated TNFalpha levels were reported in patients with ARF. However, in our sample of patients with ARF (n = 66), no such association was found. No interactive effect was found between the TNFalpha polymorphism at position -308 and no association was detected with disease progression. These findings suggest that the role of TNFalpha in ARF may be in linkage disequilibrium with some other severity genes not yet genetically determined.

Number of follicular waves and their effect on pregnancy rate in the cow.

In the study, the relationship of follicular growth waves, oestradiol and pregnancy rates were investigated during oestrus cycle in cows. A total of 22, Brown Swiss cows (3-5 years old) were used for the study. The ovaries of animals were examined from sixth day of cycle to next oestrus by ultrasound. The follicles that were present in the ovarium were recorded. Follicular growth was observed every day by means of ultrasound examination. The blood samples were taken for analysis of oestradiol simultaneously with ultrasound examinations. The oestrus animals were inseminated. Each animal that inseminated was examined by ultrasound on day 28 after insemination for pregnancy diagnosis. Two follicular growth waves were observed in nine of 22 (40.9%), three waves in 13 of 22 (59.1%) animals. The oestradiol was found in the same concentration but in different release patterns between two and three waves animals. Pregnancy rate in cows with three and two follicular waves did not differ. In conclusion, emergence of three waves of follicular growth was higher in Brown Swiss cows, the analysis of oestradiol could be used for determination of the wave numbers and the animals with different waves may have had the same pregnancy rates.

Effects of N-acetylcysteine treatment on oxidative stress in acetic acid-induced experimental colitis in rats.

We assessed the possible protective effects of N-acetylcysteine (NAC) against toxic damage in the rat colon. Two doses of NAC (20 mg/kg and 100 mg/kg) given for 2 days and 7 days after acetic acid administration (to induce colitis) were tested. NAC was dissolved in saline and administered locally (intracolonic), systemically (intraperitoneal) or in a combination (intracolonic and intraperitoneal). Several parameters, including macroscopic and histopathological scores and myeloperoxidase, glutathione and nitric oxide concentrations were measured using standard assay procedures. Treatment with 100 mg/kg NAC for 7 days significantly decreased tissue myeloperoxidase, glutathione and nitric oxide concentrations. The 20 mg/kg dose had no protective effects. The data indicate that NAC substantially reduced the degree of colonic injury, probably by regulating free radical production and inhibiting inflammation. It may, therefore, have a role in the treatment of inflammatory bowel disease.

Effects of mast-cell stabilization in cerulein-induced acute pancreatitis in rats.

AIM: In this study we aimed to clarify the role of mast cells in the development and progression of inflammation in cerulein-induced acute pancreatitis (AP) in rats. We have also examined the effects of ketotifen; a mast-cell stabilizing agent in the treatment of acute pancreatitis and its relation with nitric oxide (NO) synthesis. METHODS: In the first part of the study we planned to examine the effects mast cell stabilization in acute pancreatitis, while the second part was focused on examining the relation between NO synthesis and the potential effects of ketotifen in AP. Wistar albino rats were randomly divided into 6 groups (n: 10). In the first part of the study, AP was induced by four subcutaneous (sc) injections of 20 microg/kg body weight of cerulein at hourly intervals in Groups A and B while Group C was treated with saline as the control group. Group B was pretreated with ketotifen 1 mg/kg (ip). In the second part, the study design was similar except for the inhibition of nitric oxide synthesis by N-nitro L-arginine methyl ester (L-NAME) 30 mg/kg (ip) in Groups D, E and F. Group D was treated with L-NAME and cerulein and Group E was treated with ketotifen, L-NAME and cerulein. Group F was treated with L-NAME and saline as the control group. Serum amylase activity and pancreatic myeloperoxidase activity (MPO) were measured. Pancreatic histology and mast-cell count in pancreatic tissue were evaluated. RESULTS: Mast cell count was found to be increased in the pancreatic tissue in cerulein-induced AP. (2.93+/-0.26 vs 1.98+/-0.26; p<0.001). Ketotifen treatment significantly reduced cerulein induced edema (1.30+/-0.21 vs 0.70+/-0.15; p<0.001), neutrophil infiltration (1.50+/-0.16 vs 0.60+/-0.16; p<0.001) and attenuated the increase in amylase (4394.0+/-149.5 U/L vs 3350.5+/-216.9 U/L; p<0.05) and MPO activity (1.14+/-0.13 U/gr tissue vs 0.54+/-0.08 U/gr tissue; p<0.001). Mast-cell count in pancreatic tissue was also decreased significantly with ketotifen pretreatment (2.93+/-0.26 vs 1.70+/-0.21; p<0.05). Inhibition of NO synthesis with L-NAME treatment decreased the beneficial effects of ketotifen. CONCLUSION: It seems likely that mast cell activity may play an important role in the initiation and progression of acute pancreatitis. Ketotifen treatment may reduce the severity of AP in rats. The protective action of ketotifen in cerulein-induced acute pancreatitis is most probably owing to mast cell stabilization and stimulation of NO synthesis.

Effects of defibrotide on aorta and brain malondialdehyde and antioxidants in cholesterol-induced atherosclerotic rabbits.

The effects of a high-cholesterol diet in the presence and absence of defibrotide, a single-stranded polydeoxyribonucleotide compound, on the lipid peroxidation product malondialdehyde, endogenous antioxidant enzymes catalase, glutathione peroxidase, and the antioxidant thiol compound GSH were investigated. Forty male New Zeland white rabbits were divided into four groups each consisting of 10 rabbits. Group I received a regular rabbit chow diet and group II 1% cholesterol plus regular chow, group III was given defibrotide (60 mg/kg per day p.o. in water) and was fed with regular chow, and group IV received defibrotide plus 1% cholesterol for 9 weeks. Blood cholesterol and malondialdehyde, catalase, glutathione peroxidase, and GSH were determined before starting the experimental diet regimen (basal). After 9 weeks, the same parameters were determined in blood, aorta, and brain tissues (end -experiment). Aortic tissue was examined under a light microscope for morphological alterations indicative of atherosclerosis. The increase in serum total cholesterol was greater in group II than group IV. Plasma malondialdehyde in group II was higher than in group III. Brain malondialdehyde in group II was higher than all other groups, and aortic malondialdehyde in this group was higher than group I and III. Serum catalase activity decreased in group II and increased in group III, compared with basal values. Brain catalase activity in group I was higher than group II, and aorta catalase in group IV was higher than in group I and III. Blood glutathione peroxidase activity in group III and IV was higher than basal. GSH concentrations decreased significantly in the cholesterol-fed groups (group II and IV). Histological alterations in the cholesterol-fed groups were more pronounced in group II. The increased levels of malondialdehyde in plasma, aorta, and brain tissue of group II suggest a role of oxygen free radicals in the pathogenesis of cholesterol-induced atherosclerosis. The higher malondialdehyde values in the brain tissues of animals in group II compared with group IV suggest a protective role of defibrotide in the brain against lipid peroxidation in the oxidant stress of cholesterol-induced atherosclerosis. Increased catalase activities in the blood and aortic tissues and increased glutathione peroxidase activities in the blood of rabbits receiving defibrotide suggest an induction of these antioxidant enzyme activities by defibrotide. These results imply that anti-atherosclerotic, anti-ischemic effects of this drug may be due to the beneficial effects on the oxidant-antioxidant balance of various tissues.