Determination of bone markers in dairy cows with parturient paresis

The collagen metabolites hydroxyproline (HYP), deoxypyridinoline (DPD) and pyridinoline (PYD) are suitable markers for bone resorption in humans and several animal species. In a field trial cows with symptoms of periparturient paresis (group A) and healthy control cows without symptoms (group B) were compared and urine and blood samples were collected on day 1, 2, 3, 4, 5, 9 and 14 after parturition. In group A the mean +/- SE serum Ca concentration on day 1 was 1.4 +/- 0.1 mmol/l whereas those of group B were 2.0 +/- 0.1 mmol/l. A significant increase of the corrected urinary HYP concentration was observed from parturition to day 14 (from 2.8 to 8.8 mumol/mmol creatinine) and the concentrations at the different times were higher in group A than in group B. The mean corrected total and free DPD and total PYD concentration in urine increased after parturition to reach a peak at day 9. For DPD and PYD the mean concentrations between the two groups did not differ significantly. The DPD and PYD are useful tools to follow bone resorption in dairy cows, although in our study no difference between the two groups could be found which means that both groups were able to mobilize Ca from bone.     

Factors affecting serum selenium and vitamin E concentrations in dairy cows

Supplementation of selenium and vitamin E to enhance disease resistance in dairy cattle has become common, particularly to prevent periparturient reproductive disorders and mastitis. To establish reference values for serum vitamin E and selenium concentrations in postparturient dairy cattle and to determine whether serum concentrations of these micronutrients varied with season and stage of lactation, cows from a stratified random sample of 50 herds were studied for 1 year. Blood samples were collected from each of the 50 study herds twice, from the 10 most recently parturient cows or from 10% of the herd, whichever was greatest. Mean concentration of vitamin E and selenium was 2.55 micrograms/ml and 78.12 ng/ml, respectively. Vitamin E concentrations were significantly (P < 0.05) higher during the summer and fall than during the winter and spring. Selenium concentrations were significantly (P < 0.05) lower during the summer and fall than during the winter and spring. Herd, season of blood sample collection, and time since parturition were significant (P < 0.02) in explaining variation in vitamin E and selenium concentrations.     

Effect of supplemental dietary vitamin E and zinc on reproductive performance of dairy cows and heifers fed excess iron

We tested the hypothesis that the incidence of retained fetal membranes could be reduced by limiting oxidative stress. Sixty-four primigravid heifers (56 Holstein and 8 Jersey) and 80 multiparous cows (64 Holstein and 16 Jersey) were used. A combination of vitamin E or Zn and Fe was fed in a 2 x 2 x 2 factorial arrangement during the last 42 d prepartum. Amounts of supplements per animal were 1000 IU of vitamin E (d, l alpha-tocopheryl acetate), 0.8 g of Zn (Zn-Met and ZnSO4), and 12 g of Fe (FeSO4.7H2O) for Holsteins and 9 g for Jerseys. Neither vitamin E nor Zn directly affected the incidence of retained fetal membranes, but plasma alpha-tocopherol was lower when fetal membranes were retained > 12 h or when vitamin E was not supplemented. Iron had no direct negative effects on reproductive performance, but cows receiving additional Fe had lower unsaturated iron-binding capacity, which, in turn, was also lower in cows that retained fetal membranes. Days to first observed estrus were reduced by supplementation with either vitamin E or Zn. Vitamin E reduced days to first artificial insemination (AI) and tended to reduce days open. Supplemental Zn tended to reduce days to first AI but did not affect days open. Milk production during the first 12 wk and AI per conception were not affected by supplementation with either vitamin E or Zn. Both vitamin E and Zn reduced days to first observed estrus, indicating improved reproductive health during the early postpartum period.     

Prevention of lens damage associated with cigarette smoke exposure in rats by alpha-tocopherol (vitamin E) treatment

PURPOSE: To evaluate the possible protective effect and mechanism of alpha-tocopherol (vitamin E) treatment on lens degeneration associated with in vivo exposure to cigarette smoke and to further clarify the role of iron in cigarette smoke-generated lens damage. METHODS: Twenty-eight male Wistar rats were randomly divided into four equal groups. Rats in groups 3 and 4 were exposed to cigarette smoke for 1 hour each day over 90 consecutive days, and rats in groups 1 and 2 were treated in similar fashion but only exposed to room air. Additionally, vitamin E was given to the rats in groups 2 and 4 via intramuscular route. At the end of the study, both eyes of all the animals were enucleated; one eye was prepared for histopathologic examination, and the fellow eye was used for the measurement of iron and calcium levels. RESULTS: Significantly higher iron and calcium levels were observed in the lenses of group 3 rats than in other groups. Similar comparisons performed between groups 1 and 2, groups 1 and 4, and groups 2 and 4 did not show any significant difference. Distinct histopathologic changes in the anterior lens epithelium, such as hyperplasia, hypertrophy, epithelial multilayering, and the presence of epithelial cells over posterior lens capsule, observed in group 3 rats were not present in other groups. CONCLUSIONS: Cataractogenesis after cigarette smoke exposure was associated with an accumulation of iron and calcium in the rat lens, and vitamin E supplementation protected such accumulations and cataractogenesis.     

Use of 1alpha-OH cholecalciferol in preventing post parturient hypocalcaemia and its potential value for the prevention of milk fever in dairy cows

Cows which received 250 mug 1alpha-hydroxy cholecalciferol (1alpha-OH D3) intramuscularly within two hours after calving suffered significantly less post-parturinet hypocalcaemia and hypophosphataemia than control cows. There was a small depression in plasma magnesium concentrations in the treated cows. 1alpha-OH D3 shows potential for the prevention or treatment of milk fever.     

Activity of placental glutathione peroxidase and superoxide dismutase in cows with and without retained fetal membranes

We recently reported that there are two different virulence-associated antigens correlated with virulence levels in Rhodococcus equi isolates from AIDS patients: virulent R. equi that kills mice with 10(6) cells expresses 15- to 17-kDa antigens and intermediately virulent R. equi that kills mice with 10(7) cells expresses a 20-kDa antigen. Environmental parameters were evaluated for their effects on the expression of these virulence-associated antigens in virulent R. equi strains by immunoblotting using monoclonal antibodies in this study. Expression of these two virulence-associated antigens of R. equi was regulated by pH and temperature; the antigens were produced maximally when the isolates were grown at 38 C and pH 6.5, but were not produced when grown at 38 C and pH 8, nor at temperatures below 30 C. The 20-kDa antigen was found to be located on the cell surface, as were the 15- to 17-kDa antigens, and showed susceptibility to proteolysis by trypsin. These results indicate that expression of the virulence-associated antigens of R. equi is dependent on the environmental conditions.     

Glutamine and vitamin E in the treatment of hepatic veno-occlusive disease following high-dose chemotherapy

PURPOSE: To analyze the nonfatal adverse events (AE) associated with a first episode of status epilepticus (SE). METHODS: We performed a population-based retrospective cohort study to determine the morbidity of SE. Participants included 184 residents of Rochester, Minnesota who experienced nonfebrile SE between 1965 and 1984. RESULTS: The etiology of SE was acute symptomatic in 100 patients and unprovoked in 84 patients. The most common seizure-types were continuous partial (n=56, 30%), generalized convulsive (n=52, 28%), and generalized with focal features (n=32, 17%). Morbidity related to SE was noted in 5 of the 146 patients (3.4%) surviving 30 days. The AE included hemiparesis (n=3), encephalopathy (n=2), mental retardation (n=1), and aphasia (n=1). All patients with morbidity had an acute symptomatic (n=4) or remote symptomatic (n=1) etiology. Thirty-four patients (18.5%) had a second episode of SE. CONCLUSIONS: Based on this retrospective study, significant morbidity related to SE is uncommon and is associated with the underlying etiology.     

Activity of 72-kDa and 92-kDa matrix metalloproteinases in placental tissues of cows with and without retained fetal membranes

We produced hypertrophic and metaplastic changes of goblet cells in rat nasal respiratory epithelium by the intranasal instillation of endotoxin (ETN). In the present study, we examined in vivo effects of indomethacin (IND), dexamethasone (DEX), and erythromycin (EM) on intraepithelial mucus production using this animal model. Intraperitoneal injection of IND (2 to 4 mg/kg body weight x 4 days) or DEX (4 to 8 mg/kg body weight x 4 days) significantly inhibited intraepithelial mucus production induced after 3 days of ETN instillations. Intraperitoneal injection of EM (100 mg/kg body weight x 8 days), aminobenzylpenicillin (ABPC, 200 mg/kg body weight x 8 days), and cephalothin (CET, 200 mg/kg body weight x 8 days) also inhibited intraepithelial mucus production induced after 7 days of ETN instillations. When compared with ABPC and CET, EM had a greater inhibitory effect. These results indicate that ETN-induced intraepithelial mucus production can be inhibited by treatment with the anti-inflammatory drugs IND and DEX. Antibiotics such as EM, ABPC, and CET will also be effective, probably by preventing secondary bacterial infection, and EM has an additional inhibitory effect on intraepithelial mucus production.     

Application of gonadotropin releasing hormone in dairy herds with fertility disturbances with regard to milk yield data and metabolic parameters]

The presented study was made to determine the factors influencing the fertility supporting effect of GnRH application at the time of insemination in a dairy herd with fertility problems. The metabolic parameters considered influencing conception results were milk yield, milk protein and milk fat and for blood parameters Urea, GOT and Bilirubin. The total effect of GnRH consisted in an improved pregnancy rate by 18.8% compared to the non treated control group. The improvement of pregnancy rate was observed mainly in groups with an adequate supply of energy at the time of insemination. Therefore the use of GnRH at insemination time is more successful, when milking test data and blood parameters are taken into account and indicate an equilibrated supply in energy. To explain these effects endocrinological regulation models are discussed.     

Change in tissue concentrations of lipid hydroperoxides, vitamin C and vitamin E in rats with streptozotocin-induced diabetes

The purpose of these studies was to determine the distribution of a lipophilic antimalarial agent, halofantrine hydrochloride (Hf), in fasted plasma from hypo-, normo-, and hyperlipidemic patients that displayed differences in lipoprotein concentration and lipid transfer protein I (LTP I) activity. To assess the influence of modified lipoprotein concentrations and LTP I activity on the plasma distribution of Hf, Hf at a concentration of 1000 ng/mL was incubated in either hypo-, normo-, or hyperlipidemic human plasma for 1 h at 37 degreesC. Following incubation, the plasma samples were separated into their lipoprotein and lipoprotein-deficient plasma (LPDP) fractions by density gradient ultracentrifugation and assayed for Hf by high-pressure liquid chromatography. The activity of LTP I in the dyslipidemic plasma samples was determined in terms of its ability to transfer cholesteryl ester from low-density lipoproteins (LDL) to high-density lipoproteins (HDL). Total plasma and lipoprotein cholesterol (esterified and unesterified), triglyceride, and protein levels in the dyslipidemic plasma samples were determined by enzymatic assays. When Hf was incubated in normolipidemic plasma for 1 h at 37 degreesC, the majority of drug was found in the LPDP fraction. When Hf was incubated in human plasma of varying total lipid, lipoprotein lipid, and protein concentrations and LTP I activity, the following relationships were observed. As the triglyceride-rich lipoprotein (TRL) lipid and protein concentration increased from hypolipidemia through to hyperlipidemia, the proportion of Hf associated with TRL increased (r > 0.90). As the HDL lipid and protein concentration increased, the proportion of Hf associated with HDL decreased (r > 0.70). As the total and lipoprotein lipid levels increased, the LTP I activity of the plasma also proportionally increased (r > 0.85). Furthermore, with the increase in LTP I activity, the proportion of Hf associated with the TRL fraction increased (r > 0.70) and the proportion of Hf associated with the HDL fraction decreased (r > 0.80). In addition, a positive correlation between the proportion of apolar lipid and Hf recovered within each lipoprotein fraction was observed within hypo- (r > 0.80), normo- (r = 0.70), and hyperlipidemic (r > 0.90) plasmas. These findings suggest that changes in the HDL and TRL lipid and protein concentrations, LTP I activity, and the proportion of apolar lipid within each lipoprotein fraction may influence the plasma lipoprotein distribution of Hf in dyslipidemia.     

Electromyography of the reticulum, abomasum and duodenum in dairy cows with left displacement of the abomasum

Electromyographic (EMG) recordings of the reticulum, abomasal corpus, pyloric antrum and duodenum of six dairy cows with left displacement of the abomasum (LDA) were made in order to substantiate abomasal atony as a prerequisite to abomasal displacement. EMG recordings were made when LDA was present as well as when absent. Mean values were determined in five of six cows for the maximum peak or amplitude, mean peak values, peak-to-peak interval and count of the electrical response activity (ERA) for each 15 min segment of the waveform recordings. Segments containing phase III migrating myoelectric activity were not analysed. LDA positive periods were compared to LDA negative periods in each cow. The 6 h period (transition period) prior to the diagnosis of LDA was analysed separately. Paired t-tests were applied to group values with statistical significance established at the P = 0.05 level. There was a significant decrease in the ERA count during the LDA positive periods in the abomasal corpus (-1.40% to -7.88%, P = 0.0217) and in the pyloric antrum (-2.05% to -11.98%, P = 0.0430). A corresponding significant increase occurred in the peak-to-peak interval. During the transition period spike activity in the duodenum increased 0.5% to 48.31% (P = 0.0474) and the peak-to-peak interval was significantly decreased. No extended periods of atony were observed in the abomasum during this study.     

Effect of bacterial endotoxin on the in vitro release of Type II phospholipase-A2 and prostaglandin E2 from human placenta

The aim of this study was to establish the effect of bacterial endotoxin lipopolysaccharide (LPS) on the release of Type II phospholipase-A2 (PLA2) and prostaglandin E2 (PGE2) from late-pregnant human placental tissue incubated in vitro. Under basal conditions, immunoreactive Type II PLA2 and PGE2 were released from tissue explants in a time-dependent manner (up to 24 h, ANOVA, P<0. 0001, n=6). The release of these mediators was not associated with a loss of cell membrane integrity, as indicated by concentrations of the intracellular enzyme, lactate dehydrogenase (LDH), in the incubation medium. Incubation of explants in the presence of LPS (0. 001-100 microg LPS/ml) significantly decreased PLA2 tissue content (P<0.02, n=6) and increased the accumulation of PLA2 and PGE2 in the incubation medium (P<0.0001, n=6). The data obtained in this study indicated that Type II PLA2 and PGE2 are released from term placenta under basal conditions and that LPS stimulated their release. The associated decrease in PLA2 tissue content is consistent with the hypothesis that LPS induces the release of stored PLA2. This study identifies one pathway by which products of bacterial infection may induce the release of a pro-inflammatory, extracellularly active PLA2 from intrauterine tissues that may promote the formation of phospholipid metabolites involved in the process of labour and delivery (e.g. the prostaglandins).     

Multicenter trial of d-alpha-tocopheryl polyethylene glycol 1000 succinate for treatment of vitamin E deficiency in children with chronic cholestasis

BACKGROUND: Malabsorption and deficiency of vitamin E causing neurological degeneration are common consequences of chronic childhood cholestatic liver disease. The objective of this study was to determine the long-term efficacy and safety of d-alpha-tocopheryl polyethylene glycol 1000 succinate (TPGS) in correcting vitamin E deficiency in children with chronic cholestasis who were unresponsive to other forms of oral vitamin E. METHODS: Sixty vitamin E-deficient children with chronic cholestasis unresponsive to 70-212 IU.kg-1.day-1 of oral vitamin E were entered into a trial at eight centers in the United States. After initial evaluation, treatment was started with 25 IU.kg-1.day-1 of TPGS. Vitamin E status, neurological function quantitated by a specific scoring system, and clinical and biochemical parameters were monitored during therapy. RESULTS: All children responded to TPGS with normalization of vitamin E status. Neurological function, which had deteriorated before entry in the trial, improved in 25 patients, stabilized in 27, and worsened in only 2 after a mean of 2.5 years of therapy. No adverse effects were observed. CONCLUSIONS: TPGS (20-25 IU.kg-1.day-1) appears to be a safe and effective form of vitamin E for reversing or preventing vitamin E deficiency during chronic childhood cholestasis.     

Factors affecting body tissue mobilization in early lactation dairy cows. 1. Effect of dietary protein on mobilization of body fat and protein

Twenty Holstein cows were fed diets that were formulated with 16 or 19% crude protein (CP) that contained, respectively, 6 and 9% ruminally undegradable protein (RUP) (dry matter basis) to study the effect of increased RUP on tissue mobilization and production parameters. Cows were enrolled in the study from -14 to 114 d postpartum. Body composition measurements using the D2O dilution technique were made at -2, 5, and 12 wk postpartum. Maximum loss of body tissue occurred between wk 2 prepartum and wk 5 postpartum during which time cows fed both treatments mobilized a mean of 54 kg of body fat and 21 kg of body protein. Cows continued to mobilize 18 kg of body fat through wk 12 postpartum, but the amount of body protein was unchanged. One unit of change in body condition score corresponded to about 40 kg of empty body fat. Partitioning of empty body energy between empty body fat and protein indicated that, for each unit of change in body energy, 93% was lost or gained as body fat, and body protein accounted for only 7%. Increasing RUP in the diet had no effect on the postpartum amounts of empty body protein, empty body fat, or empty body energy. Milk production was 39.8 kg for cows fed the 16% CP diet and 42.4 kg for cows fed the 19% CP diet. There was an interaction of treatment by week postpartum. Both dry matter intake and milk production were lower during the first 6 wk postpartum but were greater thereafter for cows fed the 19% CP diet than for cows fed the 16% CP diet. Milk CP percentage was higher (3.08% vs. 2.89%), and milk CP yield tended to be greater (1.29 vs. 1.15 kg/d), for cows fed the 19% CP diet.     

The role of vitamin E in T-cell differentiation and the decrease of cellular immunity with aging

Spontaneously hypertensive rats (SHR) as a model for aging were used in this experiment and fed a regular (50 IU/Kg diet) or high vitamin E (500 IU/Kg diet) diet for 6 weeks. At 12 weeks old, they were killed and assayed. Although proliferation of thymic lymphocytes was significantly decreased in SHR fed the regular diet compared to Wistar Kyoto rats (WKY) fed the same diet, high vitamin E diet enhanced proliferation of thymic lymphocytes in SHR to almost the levels in WKY fed the regular diet. In addition, the expressions of both CD4 and CD8 antigens on CD+CD8+ T cells, immature T cells existing in thymic cortex, were also decreased in SHR, and significantly improved by high vitamin E diet. These results suggest that high vitamin E diet enhances thymic lymphocyte proliferation through increased T-cell differentiation in thymus. Then, the effect of vitamin E on T-cell differentiation in thymus was investigated by using male Fisher rats. Rats were divided into three groups; vitamin E-free, regular and high vitamin E groups and fed a diet containing various levels of vitamin E (0, 50 and 500 IU/Kg diet) for 7 weeks. Although the percentages of CD4+CD8- and CD4-CD8+ T cells in thymocytes were significantly greater in the high vitamin E group, the percentage of CD4+CD8- T cells inversely decreased in the vitamin E-free group compared to the regular group. We have tried to investigate the mechanism of the increased T-cell differentiation in thymus of rats fed the high vitamin E diet through cytokine production, and thymic epithelial cell (TEC) and macrophage functions. We have found that vitamin E enhances T-cell differentiation through the increase of not macrophage but TEC function in thymus, which is associated with the increased binding capacity of TEC to immature T cells via increased expression of adhesion molecule, ICAM-1. These results suggest that vitamin E is a potent nutrient for promoting health in the aged via the improvement of cellular immunity decreased with aging.