bovine morphometry

8/4/2019 Bovine Morphometry

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Morphometry of Bovine Dilated Cardiomyopathy

P. Nart, A. Williams, H. Thompson and G. T. Innocent*

Department of Veterinary Pathology, *Comparative Epidemiology and Informatics Group, Institute of Comparative

Medicine, Glasgow University Veterinary School, Bearsden Road, Glasgow G61 1QH, UK

Summary

Bovine dilated cardiomyopathy (BDCM) is a primary disease of the myocardium that has been describedin Holstein-Friesian cattle worldwide in the last 20 years. The principal morphological changes in themyocardium are interstitial fibrosis and increased variability in cardiomyocyte size. Sections of heartmuscle from nine cases of BDCM and nine unaffected controls matched for age, sex and breed werestudied by means of a computer-assisted image analyser to measure the degree of fibrosis, and thecardiomyocyte cellular and nuclear cross-sectional area and length. The amount of connective tissue inthe hearts of BDCM cases was increased by 6.7 times, the nuclear transverse cross-sectional area by 1.9times, and the cardiomyocyte length and cross-sectional area by 1.7 and 1.6 times, respectively. Thisresulted in an estimated 2.5-fold increase in mean cardiomyocyte volume. Animals with clinical signs ofBDCM showed a mean loss of 51% of the total number of cardiomyocytes as compared with controls. Ofthe five parameters studied, the percentage of fibrosis was found to be the most consistent discriminatorfor BDCM. It is possible that the degree of fibrosis could be used to distinguish BDCM from other cardiac

diseases of cattle.q 2003 Elsevier Ltd. All rights reserved.

Keywords: cardiomyocyte morphometry; cardiomyopathy; cattle; myocardium

Introduction

The first published report of bovine dilatedcardiomyopathy (BDCM) in Holstein-Friesiancattle came from Japan (Sonoda et al., 1982). It

was also reported in Switzerland (Martig et al.,1982), Canada (where cases had been recordedsince 1971; Baird et al., 1986), Sweden (Olsson,1987), Australia (McLennan and Kelly, 1990), theUnited Kingdom (Bradley et al., 1991) and Den-mark (Leifsson et al., 1994). The main clinical signsof BDCM are those associated with severe con-gestive heart failure, and the gross pathologicalfindings include a dilated heart, congested liver,

ventral subcutaneous oedema and ascites or hydro-thorax. Histologically, the heart shows diffusefibrosis, and the cardiomyocytes focal degeneration,

extensive vacuolation and variability in calibre(Bradley et al., 1991). The aetiology of BDCM inthe Holstein-Friesian breed is still unknown, butDolf et al. (1998) proposed that an autosomalrecessive gene might play a role. Dilated cardio-myopathy (DCM) in man may also follow a familialpattern (Towbin and Bowles, 2002) and BDCM has

been proposed as a model of human DCM becauseof similarities in clinical features and pattern ofprotein expression (Eschenhagen et al., 1995;

Weekes et al., 1999).Morphometry is the process of producing, from

images of two-dimensional histological sections,measurements from which three-dimensional

volume, surface area, and number and length oftissue components can be determined. The tissuesfunctional capacity can then be estimated byquantifying the volume fraction of the parenchymaand stroma and their proportional relationships(Loud and Anversa, 1984). Morphometric studies

J. Comp. Path. 2004, Vol. 130, 235245

www.elsevier.com/locate/jcpa

00219975/$ - see front matter q 2003 Elsevier Ltd. All rights reserved.

doi: 10.1016/j.jcpa.2003.11.002

Correspondence to: A. Williams, Department of Pathology andInfectious Diseases, Royal Veterinary College, Hawkshead Campus,Hawkshead Lane, North Mymms, Hertfordshire AL9 7TA, UK.
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can be undertaken with a light or an electron

microscope and the data obtained either bycomputer-assisted image analysis or by the moretraditional point-counting method with a squaregrid. In the latter, intersections of the grid(points) falling on features of interest arecounted and expressed either as a percentage oras a proportion of total points. However, computer-assisted image analysis measures larger areas in ashorter time (Beltrami et al., 1996) and the resultsagree closely with those obtained by the classicpoint counting method (Porzio et al., 1995); it istherefore often the method of choice.

Morphometric analysis of human DCM has

demonstrated increased fibrosis, cardiomyocytehypertrophy and fibre elongation. Estimates ofthe degree offibrosis in DCM in man range from 14to 20%, as compared with a baseline of 3% incontrol hearts (Dick et al., 1982; Unverferth et al.,1986; Beltrami et al., 1995; Ohtani et al., 1995).Studies of cardiomyocyte length in DCM showedincreases of 40% (Gerdes, 1992) and 59% (Bel-trami et al., 1995) in man and of 35% (Spinale et al.,1991) and 50% (Kajstura et al., 1995) in exper-imental models of pacemaker-induced DCM indogs. Cardiomyocyte hypertrophy, which may bemeasured as increases in width, diameter or cross-

sectional area, has been reported in human DCMas 50% (Rowan et al., 1988), 30% (Dick et al., 1982;Unverferth et al., 1986) and 20% (Beltrami et al.,1995). Doubling of the nuclear cross-sectional area

was reported by Rowan et al. (1988), and anincrease in cardiomyocyte nuclear size was relatedbyFigulla et al. (1985) and Pelliccia et al. (1994) todecreased functional status and poor prognosis.Left ventricular failure was associated with anestimated 39% loss of ventricular cardiomyocytes(Kajstura et al., 1995), and with a positive corre-lation between the extent of cardiomyocyte lossand cellular hypertrophy in samples taken at

necropsy. However, there appeared to be little ifany association between histological changes seenon cardiac biopsy in human DCM and clinical signsand prognosis (Baandrup et al., 1981); this mayreflect the fact that biopsies are usually taken fromthe right ventricle, whereas cardiac function ismore dependent on the left ventricle. Nevertheless,the degree of fibrosis is correlated with a reductionin the ejection fraction or contractibility of theheart (Schwarz et al., 1983; Ohtani et al., 1995).

Cardiomyocyte hypertrophy and interstitialfibrosis are the main qualitative morphologicalfindings in both human and bovine DCM (Robin-son and Ferrans, 1975; Furuoka et al., 2001).However, no previous studies have quantified

cardiomyocyte hypertrophy and interstitial fibrosis

in BDCM. The purpose of the present study,therefore, was to determine the main quantitativemorphological changes in BDCM by objectivestatistical analysis and to identify the most consist-ent and relevant histological findings of this cardiacdisorder. The total numbers of cardiomyocytes inthe hearts of animals with BDCM and controlanimals were estimated from the measurements inan attempt to understand the pathological mech-anisms of this disease.

Materials and Methods

Tissues Examined

Samples from the outer (free) wall of the left ventricle of the heart were collected from nineHolstein-Friesian cattle (nos 19) in which BDCMhad been diagnosed at the Glasgow University

Veterinary School Pathology Department over aperiod of 9 years. The diagnosis was made on thebasis of clinical findings and gross pathology,followed by histopathological confirmation. Con-trol material was obtained from apparently normalhearts of nine unaffected animals (nos 1018) matched for age, sex and breed with the diseased

animals slaughtered at an abattoir.To estimate the degree of fibrosis in control and

affected hearts, longitudinal sections of myocar-dium stained with Sirius red and picric acid(Junqueira et al., 1979) were examined by lightmicroscopy, and a bit map image was developedfrom the original image by means of the KS 300 V.3software package (Image Associates/Zeiss; Ober-kochen, Germany). The percentage of fibrosis wascalculated by comparing the proportion of fibroustissue (Sirius red positive, Fig. 1a; recognized as

white in the bit map image) with the total of alltissue (black and white) (Fig. 1b).

Estimations of cardiomyocyte area, nuclear areaand nuclear length were made from sectionsstained by haematoxylin and eosin (HE) (Bancroftand Stevens, 1996). Areas with transverse sectionsof myofibres were selected. The contour of thefibres was then drawn manually (as shown in Fig.1c). The same method was used for nuclear areaand nuclear length. Estimates of cardiomyocytelength were made on sections stained with phos-photungstic acid haematoxylin (PTAH), whichclearly demonstrates intercalated discs (Bancroftand Stevens, 1996) (Fig. 1d). Quantitative measure-ments of area and length were taken automaticallyby a multipurpose colour image processor with theKS 300 V.3 software package. Two recorded

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command sequences (macros) were created foranalysing data.

Numbers of Measurements Made and Statistical Analysis

A pilot study was first undertaken to determine thenumber of observations required to distinguishbetween affected and control animals in respect ofthe various cardiomyocyte parameters. Six samplestaken from each of four healthy animals and allnine cases of BDCM were measured for degree offibrosis and cardiomyocyte cross-sectional area.

Application of Bartletts test (Paradine and Rivett,1960) indicated that although the values forunaffected animals were homoscedastic (equal

variance), the values for the animals with BDCM

had variances that were different from the healthyanimals and from each other. Standard tests fordifferences between groups require that all groupshave the same variance. Due to the difficulties incalculating power when the variances between and

within groups vary, the variances in the pilot studywere used to calculate minimum significant differ-ences in a t-test with Welchs correction forheteroscedasticity. The numbers of observations

were chosen with a significance level ofP, 0:05 inmind. Thus, 30 measurements of cardiomyocytelength, nuclear length and nuclear area and fivemeasurements of fibrosis per animal were judged tobe sufficient to distinguish between groups. Cross-sectional areas of 60 cardiomyocytes per animal

Fig. 1a d. (a) Sirius red staining of myocardium of case 1 showing fibrous tissue stained red. (b) Computer-generated bit map ofFig. 1a rendered black and white to enable the computer to calculate the percentage of fibrosis (now white). (c) HE-stained section of the myofibres of case 1 in transverse section, and the hand drawn contours to delineate cross-sectionalarea. (d) PTAH staining of cardiomyocytes in longitudinal section with hand-drawn line between intercalated discs. Bar,200 mm (a,b); 20 mm (c); 100 mm (d).

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were measured, however, because of the greater

variability of this parameter.Histological sections from all 18 animals werethen sampled systematically, since systematicsampling yields smaller errors than randomsampling in histometrics (Ebbeson and Tang,1967). In the present study, constraints arisingfrom the random orientation of the cardiomyocytes

within the section were overcome by carefulselection of appropriate fields (i.e., those in

which the myocytes were aligned transversely orlongitudinally to the section plane), thereby ensur-ing accurate systematic measurements. Since thepilot study had identified the heteroscedastic

nature of the data, and since repeated measureswere taken for each animal, a method of analysiswas required that was suitable for such data. Onesuch method is that of iterative generalized leastsquares, a generalization of the least squaresmethod for normally distributed data, whichprovides maximum likelihood estimators for multi-level mixed-effects models (Goldstein, 1986, 1989;Ihaka and Gentleman, 1996). This is implementedin the gls function in the R statistical packagethat was used to analyse the data arising from themorphometrical analyses in this study (Ihaka and

Gentleman, 1996). In the statistical tests, signifi-

cance was set at the 5% level.The analyses of measurements of each parameterfor each animal were then converted into aboxplot representation (see Figs 26). In theseboxplots, the extremes of the box indicate the 25thand 75th quartiles. Values that were more than twice(vertical lines, ending with an open horizontal bar)the interquartile range away from the median wereconsidered outliers and markedwith an open circle.The whiskers at each end of the plots extend to theextremes of the non-outlier data. The traverse lineacross the boxplot represents the median value.

Statistical analysis was used to determine if there

were significant differences between diseased andcontrol animals for the five parameters studied.

Animals with BDCM that appeared to differ lessmarkedly from the controls than the rest of theaffected group were then tested to determine ifthey were indeed significantly different from thecontrols. The sub-groups derived from comparingthese animals against the control group are marked

with a filled triangle or filled circle that indicatesthe value of the mean for that particular sub-group.

The heart weight was recorded in four BDCMcases and four controls. The heart weights were

Fig. 2. Percentage of fibrosis. Vertical axis: fibrosis as percentage of the total area examined in histological sections. Horizontal axis:

bovine dilated cardiomyopathy (BDCM) cases (animals 19); controls (animals 1018). A subgroup composed of animals 6and 9 (triangles) was also compared with the control group. The horizontal dotted lines represent the weighted mean of theanimals with BDCM and of control animals.

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compared between groups by means of a MannWitneyU-test. The total volume of the myocardium(tissue volume) was determined by dividing its

weight by the specific gravity of muscle tissue,1.06 g/ml (Mendez and Keys, 1960; Loud and

Anversa, 1984). An approximation of cardiomyo-cyte volume was then made, assuming a cylindricalform, from the mean values of area and length forthe BDCM and control groups. The total numberof cardiomyocytes contained in the heart tissue was

then calculated by the formula:

Total numbers of cardiomyocytes

Heart volume12 percentage of fibrosis=100

Meancardiomyocyte volume:

Results

The values obtained for amount of interfibrillarcollagen, and length and cross sectional area of thecardiomyocyte and its nucleus are summarized inTable 1 and boxplots of the values of measurements

taken from the hearts of each animal for the fiveparameters studied are shown in Figs 2 6.

Fibrosis

There was significantly P, 0:01 more fibrosis inthe nine animals with BDCM mean 22% thanin the nine controls mean 3% (Fig. 2). Asanimals 6 and 9 had values that were clearly lowerthan those of the other animals with BDCM,

a second analysis was conducted. A statisticaldifference was also found when animals 6 and 9(as one subgroup) were compared with thecontrols P, 0:01:

Cardiomyocyte Cross-sectional Area

A significant difference P, 0:01 was foundbetween the cardiomyocyte cross-sectional areafor the group of nine animals with BDCM(mean 599 mm2) and the group of nine controlanimals (mean 366 mm2) (Fig. 3). However,considerable variation was seen between individualanimals with BDCM, and there was a clear overlapin values between some animals in the BDCM

Fig. 3. Cardiomyocyte cross-sectional area. Vertical axis: area expressed in square microns. Horizontal axis: bovine dilatedcardiomyopathy (BDCM) cases (animals 19); controls (animals 1018). The selected subgroup for comparison with the

controls was composed of cases 3 and 6 (triangles). The horizontal dotted lines represent the weighted mean of BDCM andcontrol groups.



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group and control animals. Thus, comparison of asubgroup composed of animals 3 and 6 with thegroup of nine controls showed no significantdifference P 0:32:

Cardiomyocyte Length

The values for the nine animals with BDCM(mean 139 mm) and the nine control animals(mean 86 mm), differed significantly P, 0:01(Fig. 4). As animal 7 had lower values than did the

other eight animals with BDCM, the values for thisone animal were compared to the group of ninecontrols; the difference was still statistically signifi-cantP, 0:01:

Cardiomyocyte Nuclear Area

The cardiomyocyte nuclear cross-sectional area incattle with BDCM (mean 26 mm2) differed sig-nificantlyP, 0:01 from that in the control group(mean 14 mm2) (Fig. 5). Inspection of theboxplots showed that the nine affected animalscould be placed in one of three subgroups. Animals1, 3, 4 and 6 (forming one subgroup) were thencompared with the controls, as was the subgroup

formed by animals 7, 8 and 9. In both instances, astatistically significant difference was foundbetween the subgroup of BDCM cases and thecontrols P, 0:01:

Nuclear Length

No significant differences P 0:15 were foundbetween animals with BDCM and the controls (Fig.6), the mean nuclear lengths for which were 14 mmand 13 mm, respectively.

Overlapping of Measurements

Data ranking enabled the percentage of measure-ments in the BDCM group that exceeded thehighest value obtained for the control group to becalculated. These results are presented in Table 2.

Measurements of Cardiomyocyte Volume

An approximation of cardiomyocyte volume wascalculated, assuming a cylindrical form, from themean values for area and length for the BDCM andcontrol groups. The mean values obtained for thecardiomyoctye cell volume in BDCM cases and

Fig. 4. Cardiomyocyte length. Vertical axis: the length of cardiomyocytes expressed in microns. Horizontal axis: bovine dilatedcardiomyopathy (BDCM) cases (animals 19); controls (animals 1018). The subgroup of BDCM cases compared withthe controls consisted of case 7 (triangle). The horizontal dotted lines represent the weighted mean of BDCM and control

groups.

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controls were 139 087 mm3 and 54 700 mm3,respectively.

Measurements of Cardiomyocyte Numbers

The heart weights of four BDCM and four controlanimals did not differ significantly P 0:67:Similarly, no significant differences were found interms of heart tissue volume. The estimated totalnumber of cardiomyocytes is given in Table 3; the

mean loss for the four cases of BDCM wascalculated to be 51%.

Discussion

This study represents the first attempt made toquantify and analyse statistically the main histologi-cal characteristics of BDCM. There were significantincreases in percentage fibrosis, in cardiomyocytelength and cross-sectional area, and in cardiomyo-cyte nuclear cross-sectional area. A mean loss of51% cardiomyocytes was calculated in animals withBDCM compared with unaffected animals matchedfor age, sex and breed. The main microscopicalcharacteristics of BDCM were ranked by their value

in distinguishing affected from control animals; thepercentage area of fibrosis gave the best discrimi-nation, followed by cardiomyocyte length, cardio-myocyte area and nuclear area. These changes canbe considered as the main morphometric featuresof the terminal stage of BDCM; as fibrosis was theonly characteristic that did not present anyoverlapping of values, it is proposed as the mostreliable discriminatory parameter for BDCM.Further studies are clearly required to investigateto what extent the characteristics analysed in this

work are altered in other cardiac diseases of cattle;it is considered, however, that the degree of fibrosisobserved in BDCM is much greater than thatpresent in other bovine cardiac diseases such as corpulmonale and congenital heart disease.

Although the affected and control groupsdiffered significantly in respect of cardiomyocytesize, there was some overlap in the values forindividual animals (Fig. 3). Thus, cardiomyocytehypertrophy does not appear to be a reliablediagnostic parameter for BDCM. Similarly,although elongation of nuclei is considered asign of hypertrophy, there was no evidence of

Fig. 5. Cardiomyocyte nuclear area. Vertical axis: area expressed in microns. Horizontal axis: bovine dilated cardiomyopathy(BDCM) cases (animals 19); controls (animals 1018). Subgroups selected for comparison with the controls were:subgroup one (cases 1,3,4 and 6) (triangles); subgroup two (cases 7, 8 and 9) (circles). The horizontal dotted linesrepresent the weighted mean of BDCM and control groups.



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an increase in the length of cardiomyocyte nucleiin BDCM cases in this study.

In cardiac disease causing a reduction in cardiacoutput, the heart maintains systemic perfusion byutilising two related mechanisms (Frank-Starlingprinciple). Thus there is an increase in restingsarcomere and muscle length to allow a greater pre-load reserve, and this muscle elongation producesan increase in muscle contractibility that results inincreased stroke volume (Strobeck and Sonnen-blick, 1986). These two adaptative mechanisms areexacerbated in DCM, but the elongation ofindividual cardiomyocytes does not necessarilyimply overall tissue hypertrophy as DCM is causedby a degenerative process. The extreme hypertro-phy of the cardiomyocytes in some BDCM cases

compared to others may indicate that such animalshave had a longer clinical illness, allowing moretime for compensatory changes to occur (Benjaminet al., 1981). However, insufficient clinical infor-mation was available to test this hypothesis in thepresent study. Moreover, the small numbers of casesprevented confirmation of any possible relationbetween cardiomyocyte loss and hypertrophy inBDCM, as described in human DCM (Kajstura et al.,1995).

Genetic studies indicate that BDCM has anautosomal recessive mode of inheritance in com-bination with some unidentified environmentalfactor (Baird et al., 1986; Satoh, 1988; Bradleyet al.,1991; Dolf et al., 1998). It would be of interest todetermine if animals heterozygous for BDCM but

Fig. 6. Nuclear length. Vertical axis: length expressed in microns. Horizontal axis: bovine dilated cardiomyopathy (BDCM) cases(animals 1 9); controls (animals 10 18).

Table 1Median, mean and standard deviation values for the five parameters studied in the BDCM and control groups

Control group BDCM group

Parameter Median Mean Standard deviation Median Mean Standard deviation

Fibrosis (%) 3.3 3.3 1.1 22 22 4.1Cardiomyocyte area (mm2) 367.75 396 184 599.49 673 429Cardiomyocyte length (mm) 86.35 87 26 139.13 142 39

Nuclear area (mm2

) 14.56 15 5 26.16 28 11Nuclear length (mm) 13.33 14 3 14.06 14 3

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without clinical disease exhibit myocardial fibrosisor cardiomyocyte elongation, as found in healthyrelatives of human DCM patients (Mahon et al.,2002). If this were the case, a morphometricapproach based on cardiac biopsies or post-mortem material would be a useful adjunct forthe detection of carriers. Three uncharacterizedproteins, detected in animals with BDCM, mayprove to be of value as markers for the disease ingenetically predisposed cattle identified throughfamily pedigrees (Weekes et al., 1999), but as yet no

direct genetic marker for the disease is available. Animals suffering from BDCM showed no

increase in cardiac weight, suggesting that theincrease in overall size of the BDCM heart is due tochamber dilatation rather than to increased tissue

volume. This is also the case in nearly 50% ofhuman patients (Rose and Beck, 1985; Gallo anddAmati, 2001). We conclude that the increase inchamber size observed in dilated hearts is mainlydue to compensatory elongation of the cardiomyo-cytes and deposition of collagen in the interstitium.

It is acknowledged that the pathological featuresmeasured in this study represent the terminalstages of BDCM and that it would be necessary toextend this work to animals at earlier clinical stages

to determine the rate of pathological progression.This would also enable the relevance of thedifferent parameters to be determined and relatedto clinical signs. Furthermore, the morphometrictechniques and statistical analysis used in this studymight also be applicable to the study of DCM inother species. The extent of cardiomyocyte losscalculated in the present study indicates that thebovine myocardium has a considerable physiologi-cal reserve, and that c. 50% of cardiomyocytes canbe lost before the affected animal develops clinical

congestive heart failure.

Acknowledgments

We thank Drs A. Philbey and A. Russell for theircritical review of this work. The archive from whichthe BDCM samples were obtained belongs to theDepartment of Veterinary Pathology and wasinitiated by Dr I.A.P. McCandlish. We also thankRichard Irvine and Lynn Stevenson for post-mortem and histological expertise, respectively.Giles Innocent was funded by The WellcomeTrust as part of the International PartnershipResearch Award in Veterinary Epidemiology. Thisstudy was supported by the University of Glasgow.

Table 2Percentage of measurements from cases of BDCM with higher values than the maximum value obtained from the control group

ParameterNumber of measurements that exceed highest

value in control groupTotal number of measurements

in BDCM group Percentage (%)

Nuclear length (mm) 0 270 0Nuclear area (mm2) 42 270 16Cardiomyocyte area (mm2) 70 480 29Cardiomyocyte length (mm) 100 270 37Fibrosis (%) 45 45 100

A value of 0% means that both groups overlap completely; a value of 100% means no overlap.

Table 3

Estimated number of myocytes contained in the hearts of BDCM-affected and control cattle

Animal no. Myocyte length (mm) Myocyte area (mm2) Myocyte volume (ml3) Fibrosis (%) Heart volume (ml) Number of myocytes

2* 153 695 107 23 3868 0.45 1012

3* 150 377 57 22 3208 0.69 1012

4* 127 621 79 23 3113 0.48 1012

6* 152 393 60 18 2453 0.49 1012

11 86 247 21 04 3302 1.61 1012

12 73 340 25 02 2594 1.07 1012

13 98 341 34 03 3538 1.08 1012

15 78 513 40 03 2358 0.60 1012

Mean values for numbers of myocytes in BDCM-affected and control animals (0.53 1012 and 1.09 1012, respectively) indicate a reduction inBDCM animals to 48.62% of control animals, i.e., a loss of 51.38%.*BDCM-affected.Control.



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References

Baandrup, U., Florio, R. A., Rehahn, M., Richardson, P. J.and Olsen, E. G. (1981). Critical analysis of endo-myocardial biopsies from patients suspected of havingcardiomyopathy. II: Comparison of histology andclinical/haemodynamic information. British HeartJournal, 45, 487493.

Baird, J. D., Maxie, M. G., Kennedy, B. W. and Harris, D. J.(1986). Dilated (congestive) cardiomyopathy in Hol-stein cattle in Canada: genetic analysis of 25 cases.Proceedings of the 14th World Congress on Diseases of Cattle,Dublin, 1, 8994.

Bancroft, J. D. and Stevens, A. (1996). Theory and Practiceof Histological Techniques, 4th Edit., Churchill Living-stone, London.

Beltrami, C. A., Della, M. V., Finato, N. and Rocco, M.(1996). Computer-assisted morphometric analysis ofthe heart. Annals of Quantitative Cytology and Histology,18, 129136.

Beltrami, C. A., Finato, N., Rocco, M., Feruglio, G. A.,Puricelli, C., Cigola, E., Sonnenblick, E. H., Olivetti,G. and Anversa, P. (1995). The cellular basis of dilatedcardiomyopathy in humans. Journal of Molecular andCellular Cardiology, 27, 291305.

Benjamin, I. J., Schuster, E. H. and Bulkley, B. H. (1981).Cardiac hypertrophy in idiopathic dilated congestivecardiomyopathy: a clinicopathologic study. Circula-tion, 64, 442447.

Bradley, R., Jefferies, A., Jackson, P. and Wijeratne, W.(1991). Cardiomyopathy in adult Holstein Friesiancattle in Britain. Journal of Comparative Pathology, 104,101112.

Dick, M., Donald, V., Unverferth, M. and Baba, N.(1982). The pattern of myocardial degeneration innonischemic congestive cardiomyopathy. HumanPathology, 13, 740744.

Dolf, G., Stricker, C., Tontis, A., Martig, J. and Gaillard, C.(1998). Evidence for autosomal recessive inheritanceof a major gene for bovine dilated cardiomyopathy.Journal of Animal Science, 76, 18241829.

Ebbeson, S. and Tang, D. (1967). A comparison ofsampling procedures in a structured cell population.In: Stereology, H. Elias, Ed., Springer, New York, p. 131.

Eschenhagen, T., Diederich, M., Kluge, S. H., Magnus-sen, O., Mene, U., Muller, F., Schmitz, W., Schlz, H.,Weil, J., Sent, U., Schaad, A., Scholtysik, G., Wuthrich,A. and Gaillard, C. (1995). Bovine hereditary cardi-omyopathy: an animal model of human dilatedcardiomyopathy. Journal of Molecular and CellularCardiology, 27, 357370.

Figulla, H. R., Rahlf, G., Nieger, M., Luig, H. andKreuzer, H. (1985). Spontaneous hemodynamicimprovement or stabilization and associated biopsyfindings in patients with congestive cardiomyopathy.Circulation, 71, 10951104.

Furuoka, H., Yagi, S., Murakami, A., Honma, A.,

Kobayashi, Y., Matsui, T., Miyahara, K. and Taniyama,H. (2001). Hereditary dilated cardiomyopathy inHolstein-Friesian cattle in Japan: association with

hereditary myopathy of the diaphragmatic muscles.Journal of Comparative Pathology, 125, 159165.

Gallo, P. and dAmati, G. (2001). Cardiomyopathies. In:Cardiovascular Pathology, M. D. Silver, I. G. Avrum andF. J. Schoen, Eds, Churchill Livingstone, Philadelphia,p. 286.

Gerdes, A. M. (1992). Structural remodeling of cardiacmyocytes in patients with ischemic cardiomyopathy.Circulation, 86, 426430.

Goldstein, H. (1986). Multilevel mixed linear modelanalysis using iterative generalized least squares.Biometrika, 73, 4356.

Goldstein, H. (1989). Restricted unbiased iterativegeneralized least-squares estimation. Biometrika, 76,622623.

Ihaka, R. and Gentleman, R. (1996). R: a language fordata analysis and graphics. Journal of Computationaland Graphical Statistics, 5, 299314.

Junqueira, L. C., Bignolas, G. and Brentani, R. R. (1979).Picrosirius staining plus polarization microscopy: aspecific method for collagen detection in tissuesections. Histochemistry Journal, 11, 447455.

Kajstura, J., Zhang, X., Liu, Y., Szoke, E., Cheng, W.,Olivetti, G., Hintze, T. H. and Anversa, P. (1995). Thecellular basis of pacing-induced dilated cardiomyo-pathy. Myocyte cell loss and myocyte cellular reactivehypertrophy. Circulation, 92, 23062317.

Leifsson, P., Olsen, S., Agerholm, J. and Basse, A. (1994).Myocardial fibrosis (cardiomyopathy) in cattle. Dansk

Veterinaertidsskrift, 77, 682684.Loud, A. V. and Anversa, P. (1984). Morphometric

analysis of biologic processes. Laboratory Investigation,50, 250261.

Mahon, N. G., Madden, B. P., Caforio, A. L., Elliott, P. M.,Haven, A. J., Keogh, B. E., Davies, M. J. and McKenna, W. J. (2002). Immunohistologic evidence of myocar-dial disease in apparently healthy relatives of patients with dilated cardiomyopathy. Journal of the AmericanCollege of Cardiology, 39, 455462.

Martig, J., Tschudi, P., Perritaz, C., Tontis, A. andLuginbuhl, H. (1982). Incidence of cardiac insuffi-ciency in cattle: preliminary report. Schweizer Archiv furTierheilkunde, 124, 6982.

McLennan, M. and Kelly, W. R. (1990). Dilated (con-gestive) cardiomyopathy in a Friesian heifer. Austra-lian Veterinary Journal, 67, 7576.

Mendez, J. and Keys, A. (1960). Density and compositionof mammalian muscle. Metabolism, 9, 184188.

Ohtani, K., Yutani, C., Nagata, S., Koretsune, Y., Hori, M.and Kamada, T. (1995). High prevalence of atrialfibrosis in patients with dilated cardiomyopathy. Journal of the American College of Cardiology, 25,11621169.

Olsson, S. O. (1987). Cardiac insufficiency in Holstein-Friesians. Svensk Veterinartidning, 39, 6365.

Paradine, C. and Rivett, B. (1960). Statistical Methods for

Technologists. English Universities Press, London.Pelliccia, F., dAmati, G., Cianfrocca, C., Bernucci, P.,Nigri, A., Marino, B. and Gallo, P. (1994).

P. Nart et al.244


11/11

Histomorphometric features predict 1-year outcomeof patients with idiopathic dilated cardiomyopathyconsidered to be at low priority for cardiac transplan-tation. American Heart Journal, 128, 316325.

Porzio, S., Masseroli, M., Messori, A., Forloni, G., Olivetti,G., Jeremic, G., Riva, E., Luvara, G. and Latini, R.(1995). A simple, automatic method for morpho-metric analysis of the left ventricle in rats withmyocardial infarction. Journal of Pharmacological andToxicological Methods, 33, 221229.

Robinson, W. and Ferrans, V. (1975). Pathologicanatomy of the cardiomyopathies. Human Pathology,6, 287342.

Rose, A. G. and Beck, W. (1985). Dilated (congestive)cardiomyopathy: a syndrome of severe cardiac dys-function with remarkably few morphological featuresof myocardial damage. Histopathology, 9, 367379.

Rowan, R. A., Masek, M. A. and Billingham, M. E. (1988).Ultrastructural morphometric analysis of endomyo-cardial biopsies: idiopathic dilated cardiomyopathy,anthracycline cardiotoxicity, and normal myocar-dium. American Journal of Cardiovascular Pathology, 2,137144.

Satoh, T. (1988). Studies on the dilated cardiomyopathyin cattle. Bulletin of the Nippon Veterinary and Zootechni-cal College, 37, 152154.

Schwarz, F., Mall, G., Zebe, H., Blickle, J., Derks, H.,Manthey, J. and Kubler, W. (1983). Quantitativemorphologic findings of the myocardium in idio-

pathic dilated cardiomyopathy. American Journal of Cardiology, 51, 501506.

Sonoda, M., Takahashi, K., Kurosawa, T., Matsukawa, K.and Chihaya, Y. (1982). Clinical and clinicopatholo-gical studies on idiopathic congestive cardiomyopathyin cattle. In: Proceedings of the XII World Congress on Diseases of Cattle Amsterdam-Utrecht, World Associationof Buiatrics, pp. 11871191.

Spinale, F. G., Crawford, F. A. Jr, Hewett, K. W. andCarabello, B. A. (1991). Ventricular failure andcellular remodelling with chronic supraventriculartachycardia. Journal of Thoracic Cardiovascular Surgery,102, 874882.

Strobeck, J. E. and Sonnenblick, E. H. (1986). Myocar-dial contractile properties and ventricular perform-ance. In: The Heart and Cardiovascular System, H. A.Fozzard, Ed., Raven Press, New York, p. 32.

Towbin, J. A. and Bowles, N. E. (2002). The failing heart.Nature, 415, 227233.

Unverferth, D. V., Baker, P. B., Swift, S. E., Chaffee, R.,Fetters, J. K., Uretsky, B. F., Thompson, M. E. andLeier, C. V. (1986). Extent of myocardial fibrosis andcellular hypertrophy in dilated cardiomyopathy.American Journal of Cardiology, 57, 816820.

Weekes, J., Wheeler, C. H., Yan, J. X., Weil, J., Eschenha-gen, T., Scholtysik, G. and Dunn, M. J. (1999). Bovinedilated cardiomyopathy: proteomic analysis of ananimal model of human dilated cardiomyopathy.Electrophoresis, 20, 898906.

Received; March 26th; 2003

Accepted; November 11th; 2003


bovine morphometry

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