Two-photon microscopic imaging of capillary red blood cell flux in mouse brain reveals vulnerability of cerebral white matter to hypoperfusion.

Despite the importance of understanding the regulation of microvascular blood flow in white matter, no data on subcortical capillary blood flow parameters are available, largely due to the lack of appropriate imaging methods. To address this knowledge gap, we employed two-photon microscopy using a far-red fluorophore Alexa680 and photon-counting detection to measure capillary red blood cell (RBC) flux in both cerebral gray and white matter, in isoflurane-anesthetized mice. We have found that in control animals, baseline capillary RBC flux in the white matter was significantly higher than in the adjacent cerebral gray matter. In response to mild hypercapnia, RBC flux in the white matter exhibited significantly smaller fractional increase than in the gray matter. Finally, during global cerebral hypoperfusion, RBC flux in the white matter was reduced significantly in comparison to the controls, while RBC flux in the gray matter was preserved. Our results suggest that blood flow in the white matter may be less efficiently regulated when challenged by physiological perturbations as compared to the gray matter. Importantly, the blood flow in the white matter may be more susceptible to hypoperfusion than in the gray matter, potentially exacerbating the white matter deterioration in brain conditions involving global cerebral hypoperfusion.

Detection of Se, Vit. E, Vit. A, MDA, 8-OHdG, and CoQ10 Levels and Histopathological Changes in Heart Tissue in Sheep with White Muscle Disease.

This study was carried out to determine vit. E, Se, vit. A, malondialdehyde (MDA), 8-hydroxy-2-deoxyguanosine (8-OHdG), and ubiquinone-10 (CoQ10) levels and histopathological changes in sheep with white muscle disease (WMD). A total of 30 sheep were used; 20 sheep with WMD were brought to our clinic for diagnosis and treatment at various times, and 10 healthy sheep were in the control group. The Se, vit. E, vit. A, MDA, 8-OHdG, and CoQ10 values of the healthy and WMD sheep were as follows: 0.917 ± 0.037, 0.790 ± 0.067; 1.190 ± 0.011, 1.090 ± 0.021; 5.400 ± 0.275, 5.200 ± 0.173; 1.602 ± 0.264, 2.636 ± 0.576; 0.656 ± 0.197, 1.485 ± 0.271; and 0.280 ± 0.044, 1.753 ± 0.551 respectively (p < 0.05). According to histopathological and immunohistochemical findings in the WMD group, hyaline degeneration, Zenker's necrosis, and dystrophic calcification were observed in the muscle fibers. Immunohistochemically, 8-OHdG staining of the heart tissue determined a severe 8-OHdG expression in the WMD group. The findings of this study suggest that MDA, 8-OHdG, and CoQ10 values could be used as diagnostic and prognostic biomarkers in sheep affected with WMD.

Evaluation of copper concentration in subclinical cases of white muscle disease and its relationship with cardiac troponin I.

The present study aims to evaluate the serum level of copper (Cu) in lambs suffering from subclinical forms of white muscle disease (WMD) and its relationship with cardiac troponin I (cTn-I) as a novel biomarker of cardiovascular disorders. Ten milliliters of jugular blood were taken from 200 lambs less than one year old to measure serum concentrations of Cu, selenium (Se), and cTn-I. The subjects were divided into 2 groups, namely, the deficient group which included 36 lambs, and the control group which included 164 lambs according to the reference serum Se concentration (50 ng/mL). Serum Se levels in the deficient group were lower than 50 ng/mL. By contrast, the control group showed Se levels higher than 50 ng/mL. Differences among the serum Cu and cTn-I levels were determined in both groups. The mean ±SD and median of serum Cu and cTn-I levels in the deficient group were lower and higher than those in the control group, respectively. A significant positive correlation was observed between serum Cu and Se levels, and also serum Cu and Se levels showed a negative correlation with serum cTn-I concentrations. Stepwise linear regression analysis showed that serum Cu levels were correlated positively with serum Se levels (p<0.05). Receiver operating characteristic (ROC) curve analysis indicated that the area under curve (AUC) of Cu was significantly higher than that of cTn-I based on the reference diagonal line. It is important to keep in mind that the value of AUC for the ROC curve is between 0.5 and 1.00, in which the lowest accuracy is related to the reference diagonal line with AUC of 0.5. A cut-off was determined to indicate which Cu level can discriminate between affected and healthy lambs. The cut-off level, sensitivity, and specificity of Cu in this study were 144.5 ng/mL, 74%, and 61%, respectively.

Detection of myocardial degeneration with point-of-care cardiac troponin assays and histopathology in lambs with white muscle disease.

The aim of this study was to evaluate the use of human cardiac troponin-I (cTn-I) and cardiac troponin-T (cTn-T) kits for the determination of myocardial degeneration in lambs suffering from white muscle disease (WMD). Cardiac troponin (cTn) analyses and necropsy were performed on 12 lambs with acute WMD. Only cTn analyses were tested in six healthy lambs. cTn-I and cTn-T tests were positive for all lambs with WMD, but negative in healthy lambs. Necropsy revealed that the cardiac and skeletal muscles of lambs with WMD had chalky white lesions, which appeared as necrosis and calcification in histopathology. The histopathological findings of the heart muscle and increased cTn in lambs with WMD suggested that marked myocardial degeneration may be detected by point-of-care cTn assays in lambs.

Serum selenium, vitamin E, and sialic acids concentrations in lambs with white muscle disease.

The aim of this study was to determine the serum concentrations of selenium, vitamin E, and total- and lipid-bound sialic acid (LBSA) in lambs with white muscle disease (WMD) before and after treatment with a commercial preparation containing selenite and vitamin E. Fifteen lambs with WMD and ten control animals were used as research materials. Blood samples were collected from both groups before- and 1 month after treatment for Se analysis by fluorimetry, whereas vitamin E and sialic acid were measured by HPLC and spectrophotometry, respectively. Compared to controls, in the diseased animals, there was a significant increase of serum total sialic acid (TSA) and LBSA, together with significant decreases of serum Se and vitamin E concentrations (p < 0.001). One month after treatment, a reversal of trend was observed with decreases of TSA and LBSA and increases of Se and vitamin E concentrations. The TSA and LBSA levels, however, remained significantly higher than those of the controls, p < 0.05 and 0.001, respectively. The Se and vitamin E concentrations of the treated animals were the same as those of controls. This is the first study on total and LBSA concentrations in lambs with WMD, showing that these markers can be used in the prognosis of the disease.

Studies on serum tocopherol and selenium levels and blood glutathione peroxidase activities in lambs with white muscle disease.

For the investigation of the cause of white muscle disease (WMD), tocopherol (Toc) and selenium (Se) levels and blood glutathione peroxidase (GSH-Px) activities were examined using lambs with WMD and their ewes. Serum Se levels of 4 lambs with WMD were low under 30 ppb, lambs showing very low levels below 15 ppb. The serum Se level was correlated with blood GSH-Px activity showing remarkably low activities in the lambs with WMD. Se contents in the organs of lambs with WMD were lower than those of control lambs, and particularly liver Se contents were deficient levels below 50 ppb. Serum Toc levels were normal, but alpha-Toc contents in organs showed very low levels, especially in the liver. The serum Toc and Se levels and blood GSH-Px activities of their ewes and other sheep kept in the same farm revealed similar results to those of lambs with WMD. Feedstuffs supplied on the farm showed the deficient level of the Se content below 50 ppb and a very low level of alpha-Toc. It was concluded that WMD of lambs in Hokkaido was nutritional muscular dystrophy resulted from deficiencies of Toc and Se to their ewes.

Studies on serum tocopherol, selenium levels and blood glutathione peroxidase activities in calves with white muscle disease.

For the purpose of clarifying the cause of white muscle disease (WMD) in calves, tocopherol and selenium levels and blood glutathione peroxidase (GSH-Px) activity were measured on 10 calves with WMD and nine of their dams. The main clinical symptoms of the 10 calves with WMD were motor disturbances including recumbency and stiffness. Serum enzyme activities (GOT, GPT, CPK, LDH) in calves with WMD increased markedly, and this increase was also observed in some of their dams. Serum tocopherol levels of calves with WMD were low, 70% of which showing deficient levels of less than 70 micrograms/100 ml. Serum selenium levels of all the calves were lower than 35 ppb, indicating a deficiency, and were accompanied by low blood GSH-Px activity. alpha-Tocopherol and selenium concentrations in organs were very low. Dams of calves with WMD showed low serum tocopherol levels, 22% of which indicating deficient levels below 150 micrograms/100 ml. Serum selenium levels in dams showed a marked decrease to under 20 ppb, and also low blood GSH-Px activity. Feedstuffs supplied in the farms to affected calves indicated very low alpha-tocopherol contents (below 3 mg/100g DM) and low selenium concentrations below 50 ppb in DM. It was concluded that WMD in calves was attributable to nutritional muscular dystrophy caused by deficiencies in tocopherol and selenium in feedstuffs supplied to their dams.

Studies on serum selenium and tocopherol in white muscle disease of foal.

In order to clarify the cause of white muscle disease (W.M.D.) in foals, tocopherol and selenium concentrations in serum and glutathione peroxidase activities in blood were measured. Examination was made on the samples from horses affected with W.M.D., the foal kept with them in the same stable, the foals kept in the stables without affected foals, and respective mares. The heavy-breed horses in Fukuoka prefecture and Tokachi district were also examined for comparison. Serum tocopherol levels of these foals were normal because after intake of colostrum. Mares of affected foals showed lower tocopherol levels than other examined mares (p less than 0.01). Serum selenium levels of all foals were below 65 ppb, showing deficient levels. The mares of affected foals had lower selenium levels than other mares (p less than 0.01). There was a good correlation between serum selenium concentration and blood glutathione peroxidase activity (r = 0.81). Selenium levels in the liver of affected foals were lower than the foals which succumbed with other diseases. Diet supplied in the stables with affected foals showed low alpha-tocopherol and selenium contents. These findings suggest that W.M.D. in foals is attributed to nutritional muscular dystrophy caused by tocopherol and selenium deficiency of their mares in late gestation period.

Influence of physical exercise on plasma creatine kinase activity in healthy and dystrophic turkeys and sheep.

Plasma creatine kinase (P-CK) activities were significantly increased after physical exercise in healthy turkeys and in turkeys with genetic muscular dystrophy. Activities as high as 100,500 mU/ml of plasma were observed. Activities remained high for at least 29 hours after exercise. Moderate exercise did not significantly affect P-CK activity in lambs. Increases in P-CK activity during expression of nutritional muscular dystrophy were readily distinguished from exercise effects; activity exceeded 160,000 mU/ml in lambs during expression of that condition.

[Proteinemia in young cattle during nutrition-induced muscular dystrophy]. / Proteinemie u mladého skotu v prubehu nutricní svalové dysofie

The origin and course of enzootic white muscle disease affecting young cattle in spring months after transfer from stables to pastures were accompanied by an apparent tendency to dysproteinemia. Clinically diseased animals showed a decrease of total protein in the blood serum and considerable changes in the protein spectrum. In comparison with findings in the set of clinically healthy controls, the animals affected by the white muscle disease showed a depression of albumins and a simultaneous increase of alpha- and beta-globulins and a decrease of gamma-globulins.

Osmotic and oxidative haemolysis of erythrocytes in calves with white muscle disease.

The stability of erythrocytes to both osmotic and oxidative haemolysis was studied in naturally occuring cases of white muscle disease of calves two to 14 weeks old. During clinical and subclinical disease the incidence of haemolysis when erythrocytes were exposed to 0-588 per cent NaCl was 74-3 +/-18-8 per cent and 76-6+/-18-6 per cent respectively, whereas in clinically healthy animals receiving 30 mg vitamin E per kg feedstuff the incidence of haemolysis was only 55-9+/-12-7 per cent. Erythrocytes of the calves receiving vitamin E supplements were completely resistent to peroxidative haemolysis whereas in the clinical and preclinical cases approximately 12-5 per cent of cells were lysed.