Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis of Canine Urinary Proteins for the Analysis and Differentiation of Tubular and Glomerular Diseases

A preliminary investigation was performed to evaluate the use of a new, noninvasive technique for the localization of canine renal lesions by electrophoresis of urinary proteins. Urine specimens from six clinically healthy, nonproteinuric dogs and 12 dogs with persistent proteinuria were examined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS PAGE). Urine electrophoretic patterns of proteinuric dogs were classified as glomerular (n = 4), tubular (n = 2), or mixed (glomerular and tubular) (n = 6), based on the number and molecular weight of the silver-stained protein bands. Renal tissues from biopsies or necropsies were obtained from eight of the dogs with proteinuric disease. Interpretation of seven of eight electrophoretograms agreed with the histologic interpretation of renal lesions. We concluded SDS PAGE is a potentially valuable technique for detection and localization of renal lesions in dogs with proteinuric disease.

Effects of dietary retinyl acetate on the promotion of hepatic enzyme-altered foci by polybrominated biphenyls in initiated rats

Vitamin A inhibits the development of some chemically-induced tumours. Since polybrominated biphenyls (PBBs) are hepatic tumour promoters and they affect vitamin A homeostasis in rats, we put forward the hypothesis that dietary levels of vitamin A would influence tumour promotion by PBBs. In the study described here, female Sprague-Dawley rats were initiated on day 1 by ip administration of diethylnitrosamine. On day 7 after initiation, the rats were fed a vitamin A-deficient basal diet that was supplemented with either 2000 IU (low-vitamin A) or 200,000 IU (high-vitamin A) retinyl acetate/kg feed. From day 30 after initiation until the end of the study the following PBBs were added to the diets: Firemaster BP-6 (10 ppm), 2,4,5,2',4',5'-hexabromobiphenyl (10 ppm) or 3,4,5,3',4',5'-hexabromobiphenyl (1 ppm). The control animals received low- or high-vitamin A diets containing no PBBs. On day 180, the rats were necropsied, sections of various tissues were stained for histopathological examination and an evaluation of hepatic enzyme-altered foci was performed. Numbers of gamma-glutamyl transpeptidase-positive foci/cm3 liver and the mean volumes of these foci were lower in the high-vitamin A groups than those in the corresponding low-vitamin A groups, but these differences were not significant. The percentage of the liver volume occupied by foci was significantly greater in the low-vitamin A with 345-HBB group than in the corresponding high-vitamin A group. Thus, high dietary levels of vitamin A had some inhibitory effect on the promotion of hepatic-altered foci by 345-HBB in initiated rats.

Effect of hexachlorobiphenyl on vitamin A homeostasis in the rat

Vitamin A status and turnover were examined in rats that had been exposed to chronic dietary treatment of 3,4,5,3',4',5'-hexachlorobiphenyl (HCB), 1 mg/kg diet. HCB caused hepatic depletion and renal accumulation of vitamin A, and a 1.7-fold increase in the serum retinol concentration. Intravenously administered [3H]retinol bound to retinol binding protein-transthyretin complex (RBP-TTR complex) was used to study the dynamics of circulatory retinol in these rats. In HCB-treated rats, the plasma turnover rate of retinol was increased compared to vitamin A-adequate untreated controls. HCB caused a 50% reduction of total radioactivity in liver, and, except for 0.5 h after the [3H]retinol-RBP-TTR dose, the specific activity of the hepatic retinyl ester pool was greater compared to control rats. The kidneys of HCB-treated rats accumulated radioactivity in the retinyl ester fraction. HCB also caused a 50% reduction in adrenal radioactivity compared with control rats. Urinary and fecal excretion of radioactivity was 3-fold higher in HCB-treated rats as compared to controls. Our findings demonstrate that chronic HCB feeding results in expansion of plasma vitamin A mass, in changes of liver and kidney retinol and retinyl ester pool dynamics and in an increased metabolism of vitamin A.

Changes in segment inertia proportions between 4 and 20 years

Growth between 4 and 20 yr produces an increase in body mass and a redistribution of that mass throughout the body. It is the purpose of this investigation to describe changes in the segment mass, radius to the mass centre and radius of gyration for a sample of males, 4-20 yr and the potential effects of these changes on joint reaction forces and moments. The data were collected annually over 9 yr in a mixed longitudinal study completed in 1985. Elliptical zones 2 cm wide were used to model the 16 segments of the body. From these and reported segment densities, mass, the coordinates of the mass centre and the principal moments of inertia were determined for the segments and the body. The parameters reported are the inertia parameters suitable for a sagittal planar analysis with the head and neck considered one segment and values given for other fused segments. The accuracy of the method was judged against the total body mass, and other accuracy estimates from the literature were examined. The parameters are presented as proportions of total mass or segment length. It is clear from the polynomial regressions that there is a substantial redistribution of the mass between segments and this is consistent with the principles of cephalo-caudal and distal-to-proximal development. The proportions for radius and radius of gyration indicate that mass redistribution within segments is comparatively small. The parameters for a 6 yr-old were compared to the parameters expected at 18, 24 and 54 yr and substantial differences noted.(ABSTRACT TRUNCATED AT 250 WORDS)

Growth of segment principal moments of inertia between four and twenty years

Although there have been numerous studies of the moments of inertia of the body segments using a variety of the techniques, few have reported the principal moments and none has considered the changes in the principal moments during childhood and adolescence. The purpose of this study was to use a mathematical model to determine the intraindividual changes and interindividual differences in the segment principal moments during growth. The body was modelled as 15 segments and composed of transverse elliptical zones of known density. Moments and products of inertia about the segment mass centroid were calculated and the principal moments and axes determined from the ellipsoid of inertia. A mixed longitudinal study of 12 boys over 9 yr for a total of 88 annual recordings covering the age range 4 to 20 yr was conducted. Polynomial regressions fitted to the intraindividual changes showed a similarity in the curves to 10 yr followed by a wide divergence of growth patterns. The changes in the principal moments across age follow the principles of cephalocaudad and distal to proximal development for all three axes. These changes are more accentuated than the changes for segment length, volume, or mass. The results were consistent with principal moments reported for cadavers and young male adult gamma radiation scans as well as estimates based on simplified models of the segments. The magnitude of the changes in principal moments with age makes it essential that appropriate parameters be used in the analysis or simulation of the movements of children and adolescents.

Effect of dietary retinoic acid on circulatory vitamin A homeostasis in polybrominated biphenyl-treated rats

Retinoic acid (RA) supplementation is known to lower the amount of retinol in circulation. In contrast, the feeding of polyhalogenated aromatic hydrocarbons results in an elevated level of circulatory retinol. We investigated the effect of short-term dietary exposure to RA on the amount of serum retinol in female Sprague-Dawley rats fed either a basal diet (control rats) or the basal diet containing 100 mg of polybrominated biphenyls (PBBs)/kg diet (PBB-treated rats). After feeding of the above diets for 137 d, RA (12 mg/kg diet) was included in both the control and PBB-containing diets. The rats were fed the RA-containing diet for 3 d and then killed (d 140). Blood samples were obtained before and after RA treatment. Chronic PBB treatment of rats resulted in lower hepatic vitamin A and higher kidney vitamin A than in control rats. Serum retinol concentration was significantly higher in rats treated with PBB for 137 d than in controls; the subsequent treatment with RA lowered serum retinol to a level that was not different from that of control rats treated with RA. Our observations agree with earlier findings that 1) PBB treatment alters vitamin A homeostasis, and 2) dietary RA lowers the amount of circulatory retinol. An important new observation is that serum retinol homeostasis in PBB-treated rats appears to be regulated by a mechanism similar to that of normal rats. Polyhalogenated aromatic hydrocarbons may thus be useful tools to study the control mechanisms of vitamin A homeostasis.

Vitamin A metabolism in rats chronically treated with 3,3',4,4',5,5'-hexabromobiphenyl

Chronic dietary administration of 3,3',4,4',5,5'-hexabromobiphenyl (HBB), 1 mg/kg diet, caused a decrease in retinol (20-fold) and retinyl esters (23-fold) in the livers of female rats, but resulted in a 6.4-fold increase in retinol and 7.4-fold increase in retinyl esters in the kidneys. Liver acyl-CoA:retinol acyltransferase and retinyl palmitate hydrolase activities were reduced while serum concentration of retinol was unaffected by HBB feeding. Metabolism of a physiological dose of [11-3H]retinyl acetate (10 micrograms), was examined in rats fed either vitamin A-adequate diet, or marginal amounts of vitamin A, or vitamin A-adequate diet containing HBB. A 13-fold greater amount of the administered vitamin A was found in kidneys of HBB-treated rats. In rats fed adequate or low amounts of vitamin A, kidney radioactivity was primarily in the retinol fraction, while in HBB-fed rats the radioactivity was associated mostly with retinyl esters. Fecal and urinary excretion of radioactivity was greatly increased in HBB-treated rats. Chronic HBB feeding results in a loss of ability of liver to store vitamin A, and severely alters the uptake and metabolism of vitamin A in the kidneys. We conclude that HBB causes major disturbances in the regulation of vitamin A metabolism.

Short-term oral administration of polybrominated biphenyls enhances the development of hepatic enzyme-altered foci in initiated rats

FireMaster BP-6 (FM), a commercial mixture of polybrominated biphenyls (PBB), has been shown to act as a tumor promoter in hepatocarcinogenesis assays in rats. Most hepatic tumor promoters must be administered for many weeks or months. Because FM is highly persistent in animal tissues, it was hypothesized that very short-term administration of FM would result in tumor promotion. Female Sprague-Dawley rats weighing 185-215 g were initiated by a two-thirds partial hepatectomy followed by 10 mg diethylnitrosamine/kg body weight (BW) 24 h later. Thirty days later, rats were gavaged with FM in corn oil, at total doses of 0, 13, or 130 mg FM/kg BW. Half the dose was given on d 30, and the remaining half was given 24 h later. At 120 d after gavage the rats were killed and necropsied. Five liver sections from each animal were histochemically stained for gamma-glutamyl transpeptidase-positive enzyme-altered foci (EAF). EAF were significantly increased over control values in initiated rats given 130 mg FM/kg. In animals given 13 mg FM/kg, EAF were increased to a lesser extent but not significantly above controls. Enhancement of these EAF in initiated rats reflects tumor-promoting activity. In this study, 24-h administration of FM in initiated rats was sufficient to enhance hepatic EAF measured 120 d later in an rats was sufficient to enhance hepatic EAF measured 120 d later in an initiation-promotion protocol, and a dose of 13 mg FM/kg was apparently close to a possible no-effect threshold level for enhancement of EAF.

Toxic effects of N-nitrosodiethylamine on nasal tissues of Sprague-Dawley rats and golden Syrian hamsters

The acute necrogenic effects of N-nitrosodiethylamine (NDEA) on nasal tissues of female Sprague-Dawley rats and golden Syrian hamsters were determined. Rats and hamsters were given a single ip dose of 0, 10, 20, 40, or 80 mg NDEA/kg body wt. After 24 hr, the rats and hamsters were killed and tissues were collected. Sections of nasal cavity and liver were evaluated histologically. All doses of NDEA caused inhibition of glycoprotein synthesis in cells of Bowman's glands in the olfactory region of rats and hamsters as determined by the loss of Alcian blue-periodic acid-Schiff staining material. Glycoprotein synthesis in other glands including the lateral nasal glands, maxillary glands, medial nasal glands, and the acinous glands near the vomeronasal organ was not affected by NDEA. Necrosis of Bowman's glands in the olfactory region of the nasal cavity occurred in rats given 20, 40, or 80 mg NDEA/kg body wt whereas the same cells were not necrotic in hamsters given NDEA. The results demonstrate the unique susceptibility of cells of the Bowman's glands to the toxic effects of NDEA given ip and indicate that nasal tissues of the rat are more susceptible to the necrogenic effects of NDEA than those of the hamster.

Sequential study on the synergistic effects of 2,2',4,4',5,5'-hexabromobiphenyl and 3,3',4,4',5,5'-hexabromobiphenyl on hepatic tumor promotion

A sequential study was completed to determine the effect of polybrominated biphenyl (PBB) congeners on the enhancement of gamma-glutamyl transpeptidase (GGT)-positive altered hepatic foci (AHF) and the development of hepatic nodules (HN) and carcinomas. Female Sprague-Dawley rats were given a single dose of N-nitrosodiethylamine (NDEA) 24 h following a 70% partial hepatectomy. Thirty days later, rats were randomly assigned to groups and fed a basal diet or the basal diet containing 10 p.p.m. 2,2',4,4',5,5'-hexabromobiphenyl (245-HBB), 0.1 p.p.m. 3,3',4,4',5,5'-hexabromobiphenyl (345-HBB) or 10 p.p.m. 245-HBB plus 0.1 p.p.m. 345-HBB for 140 days followed by a basal diet for up to another 310 days. Rats from each group were killed 170, 240 or 480 days after partial hepatectomy. Dietary exposure to 245-HBB and 245-HBB plus 345-HBB enhanced the development of AHF and HN whereas 345-HBB alone did not. The combination of 245-HBB and 345-HBB caused a synergistic effect on the development of AHF and HN. The number of hepatocellular carcinomas was low and evenly distributed among the groups of rats fed diets containing PBB.

The growth of children's moment of inertia

As children grow, their moments of inertia increase. The magnitude and timing of these changes can affect the rotations of the body. The present study evaluated inter-individual differences in the transverse centroidal moment of inertia for 12 boys between 5 and 16 yr, using intra-individual data from three successive years. Segmental masses and moments of inertia were estimated using the elliptical zone model and the model then repositioned into two configurations: a layout position from a back handspring and a tuck position from a back somersault. In each case, the mass centroid and the moment of inertia about the transverse axis were calculated. With growth indexed by age, it was shown that the rate of change increases with age. For the children 10 yr and younger, the rate of change of moment of inertia was approximately 30% of the rate for the older children. Also, at each age level, there was a wide range of moments of inertia. In order to improve the prediction of moment of inertia, height and mass were tried as predictors with a noticeable improvement in correlation and linearity. The best predictor, however, was found to be the product of mass and height squared (M X H2) with correlations of 0.99 and 0.97. It is suggested that, because of the effects of growth on the moment of inertia. M X H2 could be used in conjunction with age in order to better appreciate the potential effects of change of moment of inertia.

Body segment mass, radius and radius of gyration proportions of children

The segment inertial parameters of children are fundamental to the analysis and simulation of their movements. Generally it has been recognized that adult parameters cannot be extrapolated and most of the anthropometric data on children are of little or no use for determining inertias. Consequently, there have been few studies of children's kinetics. In response to this problem a longitudinal investigation, the Laurentian Study of Biomechanical Development, was launched and in this paper the effects of growth on selected segmental size and inertial parameters are reported for boys between the ages of 4 and 15 yr. The twelve subjects, representing heterogeneous body types were followed over 3 yr for a total of 36 observations. Elliptical zones 2 cm wide were used to model the body and segment inertias calculated using segment densities from the literature. These inertias were the mass, moment of inertia and mass centroid location for a fourteen segment planar representation of the body. The general accuracy mean error based on body mass was 0.203% which is consistent with reports from similar studies and techniques. Plots of segment mass proportions with respect to age showed a decrease in the head proportion balanced by increases in the thigh, shank, foot and upper arm proportions in particular. The trends for each segment were consistent with the trends for linear measures reported in the anthropometry literature. Radius proportions to the mass centroid and radius of gyration proportions were also plotted and showed smaller but consistent changes with respect to age. Linear regressions were then fitted to the distributions and standard errors calculated. The magnitude and slope of the regressions were for the most part consistent with a reported cross-sectional study of Japanese children. Where data were available, predicted parameters were compared with the reported parameters for a 12 yr old analyzed using a different mathematical model. Comparisons were also made between the predicted parameters at 15 yr and the reported parameters for healthy young adults who had been scanned using a gamma-radiation technique. For most parameters there was either good agreement or differences could be explained logically. The traditionally used parameters from older cadavers were quite inconsistent with the above. The variances of the 36 observations about the regression lines as indicated by the standard errors were small. As an illustration of the effect of these variances, the trunk parameters for a 10 yr old performing a standing jump for distance were decreased by 1 S.E. and this matched by increases for the thigh, shank and head.(ABSTRACT TRUNCATED AT 400 WORDS)

Chronic active hepatitis in 26 Doberman pinschers

Chronic active hepatitis with increased hepatic copper concentration was diagnosed in 25 female and 1 male Doberman Pinscher dogs. Common clinical signs included polyuria/polydipsia, weight loss, anorexia, icterus, and ascites. Increased liver enzyme activities and abnormal liver function test results were the most consistent clinicopathologic changes. The dogs were assigned to 3 groups on the basis of clinical course of the disease. Group 1 dogs (n = 12) had clinical signs of advanced liver failure and died within one week. Group 2 dogs (n = 7) had less severe clinical signs of liver disease and died within one month. Group 3 dogs (n = 5) did not have clinical signs of illness or had mild clinical signs of liver disease and died 1 to 42 months after initial evaluation. One dog could not be reevaluated and another dog was alive 3 months after initial examination. Treatments consisted of supportive care for dogs in group 1, and dietary manipulations and corticosteroids for dogs in groups 2 and 3. The association of increased liver copper concentration and chronic active hepatitis is not known.

A general Newtonian simulation of an n-segment open chain model

This paper presents a set of general Newtonian equations which govern the simulation of movement of a body represented by n open chain links. The input for the simulation consisted of the joint moment of force histories, lengths, masses and moments of inertia, the initial absolute angular displacements and velocities and, for the fixed or constrained axis of the nth segment, the acceleration history. Angular accelerations were then determined by solving n linear equations simultaneously, and angular velocities and displacements determined by integrating forwards. The final output was in the form of a graphical display of the linked figure. Applications of the simulation were demonstrated using three-segment representations of movements of the upper and lower extremities and a five-segment representation of a jump. Good agreement was achieved between the displayed angular displacements for the original and simulated movements. The potential for varying the input data has been examined and the implications of anticipating the effects of changed torques, inertial characteristics including attached prosthetic or sports implements and/or the initial conditions for a movement are discussed.

Effect of varying the length of exposure to polybrominated biphenyls on the development of gamma-glutamyl transpeptidase enzyme-altered foci

Female Sprague-Dawley rats were fed polybrominated biphenyls (PBBs) for 15 or 140 days after a 70% partial hepatectomy and diethylnitrosamine administration (10 mg/kg body weight) to determine the effect of varying the length of exposure to PBBs on the enhancement of gamma-glutamyl transpeptidase enzyme-altered foci. fireMaster BP-6R, a commercial mixture of PBBs, was fed to rats at a dietary concentration of 100 mg/kg for 15 days or 10 mg/kg for 140 days during the promotion phase of a two-stage hepatocarcinogenesis assay. Results indicate that short term exposure to PBBs is as effective as long term exposure in enhancing the development of enzyme-altered foci.

Hepatic tumor-promoting ability of 3,3',4,4',5,5'-hexabromobiphenyl: the interrelationship between toxicity, induction of hepatic microsomal drug metabolizing enzymes, and tumor-promoting ability

Female Sprague-Dawley rats were fed diets containing 0, 0.01, 0.1, or 1.0 mg/kg 3,3',4,4',5,5'-hexabromobiphenyl (345-HBB) for 140 days after a 70% partial hepatectomy and diethylnitrosamine administration (10 mg/kg body weight) to determine if 345-HBB had tumor-promoting ability in a two-stage hepatocarcinogenesis assay. Tumor-promoting ability was assessed by measuring enzyme-altered foci exhibiting gamma-glutamyl transpeptidase activity. Enhancement of enzyme-altered foci occurred only at a dietary concentration of 345-HBB (1.0 mg/kg) that was toxic. The toxic effects were decreased body weight gain, involution of the thymus, increased liver weight, histologic and ultrastructural alterations of the liver, and elevated serum concentrations of aspartate aminotransferase. 345-HBB is a strict 3-methylcholanthrene (MC) type of hepatic microsomal drug metabolizing enzyme inducer and caused a dose-related increase of cytochrome P-450. 345-HBB, at a dietary concentration of 0.1 mg/kg, caused a physiologic response in rats as determined by induction of hepatic microsomal drug metabolizing enzymes, but there was minimal evidence of toxicity and no evidence of tumor-promoting ability. Results indicate that there can be induction of MC type of hepatic microsomal drug-metabolizing enzymes without toxicity or tumor-promoting ability and that the tumor-promoting ability of 345-HBB was most likely the result of hepatic degeneration and necrosis. This finding is in contrast to previous studies in which a closely related congener, 2,2',4,4',5,5'-hexabromobiphenyl, enhanced the development of enzyme-altered foci at dietary concentrations that were not hepatotoxic.

Effect of combined antibiotic therapy on fertility in brood bitches infected with Brucella canis

Bitches with naturally occurring Brucella canis infection were treated with combined antibiotic therapy consisting of tetracycline, dihydrostreptomycin, and trimethoprim-sulfadiazine. After treatment, all but 1 bitch became abacteremic, and serologic titers declined for a variable length of time (3 months to 1 years). Abortion did not occur while these bitches were abacteremic. Although sequential antibiotic therapy for 6 weeks did not eradicate Brucella canis from affected bitches, it did not prevent abortion. The number of live pups whelped and weaned by treated bitches was comparable with that in bitches before they became infected.

Polybrominated biphenyls as promoters in experimental hepatocarcinogenesis in rats

Female Sprague Dawley rats were fed polybrominated biphenyls (PBB) for six months after a 70% partial hepatectomy and diethylnitrosamine administration (10 mg/kg body weight) to determine if PBB could serve as a tumor promoter in a two stage hepatocarcinogenesis test system. Firemaster BP-6, a commercial mixture of PBB, and its major congener, 2,2',4,4',5,5'-hexabromobiphenyl (HBB) were used in this study. Tumor promoting ability was assessed by measuring enzyme altered foci exhibiting gamma glutamyl transpeptidase activity. Dietary concentrations of 10 and 100 p.p.m. of the mixture of PBB and of HBB were found to be promoters of hepatocarcinogenesis. The mixture of PBB had a greater tumor promoting ability than HBB.

The effect of a 12-month growth period on the body moments of inertia of children

The effect of growth over a 12-month period on the principal moments of inertia for the body was investigated. The body was considered to be modelled as composed of elliptical zones 2 cm wide. Twelve children between the ages of 4 and 12 years and of different body types were tested and retested after 12 months. Moments of inertia for the three principal axes were calculated. A comparison of the results for the moment of inertia about the centroidal transverse axis showed increases from 12-57%. The results for the longitudinal centroidal axis ranged from 8-92%. For most of the children these percentage changes exceeded those in the traditional indicators of age, height, and mass. The product, mass times height squared (MH2), appeared to indicate the changes more accurately. Extreme changes were noted for a 12/13-year-old undergoing pubescent growth, a 6/7-year-old ectomorph, and a 4/5-year-old endomorph. It is suggested that the extreme changes, in particular, would make rotational movements difficult and there could be an extended adaptation period.