Correlation of Nuclear Morphometric Features with Animal and Human World Health Organization International Histological Classifications of Canine Spontaneous Seminomas

The aim of this study was to correlate nuclear morphometric features with animal and human World Health Organization International Histological Classifications in canine seminomas. Twenty-three canine seminomas were classified, according to Animal World Health Organization International Histological Classification as intratubular, intratubular with signs of invasion, or diffuse and according to Human World Health Organization International Histological Classification criteria as spermatocytic and typical. The morphonuclear characteristics of tumors were quantitatively evaluated by means of digital cell image analyses of hematoxylin and eosin-stained nuclei. In particular, the mean nuclear area, mean nuclear perimeter, mean nuclear form factor, and their respective standard deviations were calculated. The relationship between the different variables and the tumor histologic types was assessed. On the basis of animal and human classification systems, statistically significant differences were observed only between intratubular seminomas with signs of invasion and the other two types and between spermatocytic and typical seminomas, respectively. In humans, it is well known that typical seminomas are more common and aggressive than spermatocytic ones. In our study, the canine seminomas classified as typical showed significantly larger and more variable nuclear area and perimeter than spermatocytic seminomas. These results support the opinion that most canine seminomas correspond to human spermatocytic seminomas and could explain the benign behavior of canine seminomas, which derive from a more differentiated type of germ cell.

Expression of endothelin-1 and endothelin-1 receptor A in canine mammary tumours

Endothelins and their receptors have been implicated in numerous diseases and have recently emerged as relevant players in a variety of malignancies. Tumours overexpress the Endothelin-1 (ET-1) and the Endothelin-A receptors (ETAR) and their interaction enhances tumour growth and metastasis by promoting tumour cell survival, proliferation and angiogenesis. In this study we have evaluated the expression of ET-1 and ETAR in 50 canine mammary tumours, compared to normal controls. Results demonstrated a progressive increase in ET-1 and ETAR expression from benign tumour to grade 1 and to grade 2 malignant mammary tumours with a decrease of expression in grade 3 carcinomas. Co-localization of ET-1 and ETAR was observed in benign mammary tumours and in G1 and G2 carcinomas, while absent in G3 carcinomas. Concluding, ET-1/ETAR can be considered reliable markers for evaluating malignancy of canine mammary tumours and could have importance for the development of specific anticancer therapies.

Increased SCE levels in Mediterranean Italian buffaloes affected by limb malformation (transversal hemimelia)

In recent years some buffalo farms in Campania have reported the birth of calves with limb malformation, especially with transversal hemimelia. We investigated 20 Mediterranean Italian buffaloes (8 males and 12 females) from one day to six months of age, of which 10 were affected by transversal hemimelia (group 1) and 10 were healthy controls (group 2). The following clinical and radiological patterns were observed in the malformed animals: hind limbs amputated, the right amputated off the second tarsus bones and the left amputated off the proximal epiphysis metatarsus, and the right thoracic limb hypoplasic (1 female); left hind limb amputated off the proximal epiphysis metatarsus (2 females and 1 male); left hind limb amputated off the third tarsus bones (1 female); left hind limb amputated off the tibia (1 female and 1 male); left hind limb amputated off the distal epiphysis metatarsus (1 female); left hind limb amputated off the first phalanx (1 male); right hind limb amputated off the proximal epiphysis metatarsus (1 male). In their malformed limbs all the animals presented more or less developed outlines of claws. The mean rate of SCE/cell in animals with transversal hemimelia was 8.80 +/- 3.19, that of the controls 6.61 +/- 2.73. The difference was statistically significant (P < 0.001).

Nuclear Morphometry in Relation to Lymph Node Status in Canine Mammary Carcinomas

The assessment of nuclear area and nuclear shape by morphometric analysis, has been investigated in 40 canine mammary carcinomas in relation to their metastatic behaviour to regional lymph-nodes. The tumours were reviewed by two experienced pathologists blinded regarding their lymph-node status, and were classified according to the histogenetically based criteria suggested by Benjamin et al. (1999). Twenty of these tumours showed lymph-node metastases (node-positive), and the other twenty were node-negative. Node-positive tumours included 6 simple adenocarcinomas, 10 ductular carcinomas, 2 anaplastic carcinomas and 2 carcinomas in mixed tumours; node-negative tumours included 18 adenocarcinomas %96, 10 simple adenocarcinomas, 8 complex adenocarcinomas %96, and 2 carcinomas in mixed tumours. Node-positive tumours showed MNA and mean SDA values significantly higher (p<0.001) than node-negative carcinomas. Data of this study, seems to confirm the importance of an histogenetically based classification in canine mammary tumours, also suggesting that morphometry may increase our prognostic performances allowing a reproducible method for detecting individual tumours with higher metastatic potential.

Pathological changes in the bone marrow of dogs with leishmaniosis

Bone marrow aspiration smears from 15 dogs naturally infected with leishmania were evaluated. Three of the dogs showed no clinical signs, six had up to three clinical signs and six had more than three. The most common pathological features of the bone marrow were megakaryocytic dysplasia in 10 of the dogs, erythrophagocytosis in eight, erythroid dysplasia in two and emperipolesis in two. The megakaryocytic and erythroid dysplasia were probably related to an increased number of marrow macrophages producing high levels of tumour necrosis factor alpha and interferon gamma. Six of the dogs with clinical signs showed bone marrow dysplastic features and erythrophagocytosis, suggesting that leishmaniosis could be the unique cause of both conditions.

Nuclear morphometry in canine acanthomatous ameloblastomas and squamous cell carcinomas

The aim of this study was to evaluate whether morphometrical analysis can be of diagnostic value for canine acanthomatous ameloblastoma. We calculated, by means of an automated image analyser, some morphometric nuclear parameters, in particular: mean nuclear area (MNA), mean nuclear perimeter (MNP), maximum and minimum diameters (MDx and MDm) coefficient of variation of the nuclear area (NACV), largest to smallest dimension ratio (LS ratio), and form factor (FF), in 8 canine acanthomatous ameloblastomas, and we compared these morphometric data to those of 13 squamous cell carcinomas of canine gingiva. The results indicated a progressive increase of the MNA, NACV, MNP and MDm proceeding from acanthomatous ameloblastomas (MNA: 42.11+/-8.74; NACV: 28,36+/-7,23; MNP: 24.18+/- 2.68; MDm: 5.69+/-0.49) to squamous cell carcinomas (MNA:49,69+/-9,10; NACV: 30,89+/-7,75; MNP: 25.63+/-2.54; MDm: 6.64+/-0.73). On the contrary, the LS ratio and the FF resulted greater in acanthomatous ameloblastomas (LS ratio: 1,63+/-0,12; FF: 1,13+/-0,002) than in SCCs (LS ratio: 1,40+/-0,12; FF:0.91+/-0.38). Moreover, the MNA, MNP,MDx and MDm resulted similar (MNA: p=0.89; MNP: p=0,65; MDm: p=0,16; MDx: p=0,13) in a subset of four acanthomatous ameloblastomas with cellular atypia (MNA:49,01+/-6,88; MNP: 26,28+/-1,99; MDm: 6.08+/-0.41; MDx: 10.18+/-0.88) and in squamous cell carcinomas (MNA:49.69+/-9,10; MNP: 25.63+/-2.54; MDm: 6.64+/-0.73; MDx: 9.26+/-1.05). While the NACV values resulted higher in typical acanthomatous ameloblastoma (29,99+/-6,06) than in atypical acanthomatous ameloblastoma (26,74+/-8,84) and similar to those of the SCCs (30,89+/-7,75). These results seem to confirm that acanthomatous ameloblastoma is a malignant or potentially malignant lesion and emphasizes that nuclear morphometry analysis can be an useful diagnostic and prognostic method in canine oral pathology.

Nucleomorphometric Analysis of Canine Cutaneous Mast Cell Tumours

Thirty-five canine cutaneous mast cell tumours (CCMCTs) were analysed by computerized nuclear morphometry. In each case, the nuclei of at least 100 neoplastic cells were measured, and the mean nuclear area (MNA), mean nuclear perimeter (MNP) and mean nuclear form factor (FF) were calculated. Significant differences in respect of MNA and MNP occurred between tumours of grades I and III and between those of grades II and III (P<0.01) but not between tumours of grades I and II (P>0.01). No significant differences in respect of FF were observed between tumours of different grades. The results obtained indicate that nuclear morphometric analysis may assist in the grading of CMCTs.

Expression of Major Histocompatibility Complex class I and II in a case of Neospora caninum myositis in a dog

Neosporosis was diagnosed in a 2-month-old dog by indirect immunofluorescence antibody test (IFAT) and confirmed by means of histopathology and immunohistochemistry. The associated myositis was characterized by Major Histocompatibility Complex expression on some muscle fibres. This finding indicates an immunological activation, of the muscle cells that, acquiring Major Histocompatibility Complex expression, may, in some way, contribute to antigen presentation. A possible role of these glycoproteins in the pathogenesis of Neospora-associated myositis is discussed.

Expression of Vascular Endothelial Growth Factor Receptor Flk-1 in Canine Mammary Tumours

Vascular endothelial growth factor (VEGF) induces endothelial cell proliferation, and the beginning of angiogenesis, by interacting with specific endothelial receptors termed VEGFR-1 (Flt-1) and VEGFR-2 (Flk-1). In this study, Flk-1 expression was evaluated immunohistochemically in 10 benign and 40 malignant canine mammary tumours. There was immunolabelling of endothelial cells located within the neoplastic proliferation and at the infiltrating periphery, and also of neoplastic cells. The number of positive endothelial and neoplastic cells, was higher in malignant than in benign tumours. Moreover, in the malignant tumours, expression of Flk-1 increased from well to less differentiated phenotypes (grade 1-3). The presence of VEGF receptor on neoplastic cells suggests that VEGF has an autocrine function in which neoplastic cells act as both VEGF producers and target cells. Thus, in malignant tumours, VEGF may contribute to neoplastic growth by inducing angiogenesis and by stimulating the proliferation of neoplastic cells.

Evaluation of angiogenesis in canine seminomas by quantitative immunohistochemistry

Angiogenesis, which assists in supplying the nutritional and respiratory needs of proliferating cells, is essential for tumour growth. Angiogenic control is complex, involving a network of cytokines, in particular vascular endothelial growth factor (VEGF), a potent endothelial cell mitogen which also stimulates neoplastic cell proliferation. The purpose of this study was to evaluate VEGF expression and microvessel density (number of microvessels per mm(2)), in canine seminomas. VEGF expression and microvessel density were higher in seminomas than in normal testicular tissue; both parameters were higher in diffuse tumours than in intratubular tumours. These data demonstrate an increase in angiogenesis in the more malignant histological types of seminoma and suggest that both VEGF and microvessel density are useful criteria for evaluating the intrinsic malignancy and growth potential of canine testicular tumours.

Nuclear morphometry in squamous cell carcinomas of canine skin

To investigate the diagnostic and prognostic value of nuclear morphometry in squamous cell carcinomas (SCCs) of canine skin, histological samples from 15 dogs were retrospectively analysed by computerized nuclear morphometry. In each case, the nuclei of at least 100 neoplastic cells were measured, and the mean nuclear area (MNA), standard deviation of MNA (SDa), mean nuclear perimeter (MNP), standard deviation of MNP (SDp), nuclear form factor (FF), and standard deviation of FF (SDf) were calculated. The morphometric data were examined in relation to tumour histological grade. No statistical differences were found between the different grades of SCC in terms of the mean values of SDa, SDp, FF or SDf. The MNA values, however, differed significantly between grades: I and III; I and IV; II and III; II and IV. The MNP values differed significantly between grades: I and III; I and IV; II and IV. The results indicate that nuclear morphometry analysis is a simple and reproducible method that could be used to provide objective diagnostic criteria for cutaneous SCCs in the dog.

Expression of vascular endothelial growth factor in canine mammary tumors

Vascular endothelial growth factor (VEGF) is a dimeric protein that stimulates angiogenesis in vitro and in vivo by inducing endothelial cell proliferation and migration. In this immunohistochemical study, VEGF-immunolabeled cells were counted in a series of 10 benign and 40 malignant canine mammary tumors. The morphologic pattern of VEGF positivity (intensity of immunolabeling and VEGF granule size and distribution) was also evaluated. A low number of cells weakly positive for VEGF with few and small granules polarized to the luminal pole was detected in benign neoplasms. In contrast, in malignancies a high number of VEGF-positive cells had strong immunolabeling, often with large granules found diffusely in the cytoplasm. This level of immunolabeling was more pronounced in the less differentiated, more malignant phenotypes (grade 3). Macrophages, which can synthesize VEGF, were strongly positive. Stromal and myoepithelial cells were negative. VEGF data were correlated statistically with intratumoral microvessel density (number of newly formed microvessels) and both measures were greater in less differentiated malignant neoplasms, demonstrating that angiogenesis and malignancy increase together. VEGF appears to be a powerful angiogenic factor in canine mammary tumors.

Expression of matrix metalloprotease-2 (MMP-2) and the activator membrane type 1 (MT1-MMP) in canine mammary carcinomas

An immunohistochemical approach was used to examine the expression of MMP-2 and the activator MT1-MMP in a series of 50 canine mammary carcinomas of different histotype and stage. MMP-2 and MT1-MMP were mainly expressed in the cytoplasm of carcinoma cells and in fibroblasts. Immunolabelling for both MMP-2 and MT1-MMP was also seen on the tumour cell membranes. This labelling pattern showed no significant association with either the histological sub-type or stage of the carcinomas. Therefore, although distinct patterns of expression of MMP-2 and MT-MMP1 were shown by these carcinomas, functional studies by means of zymography would be required to provide useful information on tumour behaviour.

Angiogenesis in squamous cell carcinomas of canine skin: an immunohistochemical and quantitative analysis

In a number of recent papers, the intratumoral microvessel density (iMVD) has been described as a promising new prognostic factor. In this study, the angiogenic rate was evaluated immunohistochemically for platelet endothelial cell adhesion molecule (CD31) in 15 squamous cell carcinomas (SCCs) of canine skin. Computer image analysis was used to measure the iMVD, which increased progressively from differentiation grade I to IV. The iMVD was consistently and significantly greater in the poorly differentiated SCC cases. The correlation of angiogenesis data with differentiation grade of canine SCCs suggests that the iMVD value may provide an additional criterion for evaluating the intrinsic malignancy and growth potential of such tumours.

The ultrastructure of pearl organs in Rutilus rubilio as revealed by scanning electron microscopy

Pearl organs are epidermal structures that in the mating season appear on different body regions of fishes belonging to Catastomidae and Ciprynidae families. In veterinary medicine, pearl organs were studied for their possible role as index of fish good quality for human feeding. Recently some authors put in evidence the possible relationship with other secondary sexual characters to establish the stage of sexual maturation in fishes. Little is known about their morphology and morphogenesis. For these reasons, pearl organs of 10 specimens of Rutilus rubilio, collected in Caserta (Italy), were studied by light and scanning electron microscopy (SEM). By means of SEM, the presence of pearl organs was demonstrated on dorsal and lateral fins too and their fine structure was studied. This study permitted to show pearl organs at different evolutive stages clarifying their morphogenesis and suggesting some inspective and functional considerations.

Expression of vascular endothelial growth factor in basal cell tumours and in squamous cell carcinomas of canine skin

The expression of vascular endothelial growth factor (VEGF) was evaluated immunohistochemically in 20 basal cell tumours (BCTs) and 15 squamous cell carcinomas (SCCs) of canine skin. VEGF was identified in all the SCCs and was particularly striking in those occurring on the toe. On the other hand, VEGF was absent in the great majority of BCTs, occurring only in those of the solid type. The results suggest that presence of VEGF is a useful additional criterion for evaluating malignancy and growth potential in tumours of these types.

Expression of beta1 integrin in relation to histological features in normal and neoplastic canine testicles

The expression of the beta1 common chain of the VLA integrin subfamily was evaluated immunohistochemically in a series of five normal and 30 neoplastic canine testicles. The tumours, consisting of seminomas or Sertoli cell tumours, were classified according to WHO criteria as intraductal without signs of invasion, intraductal with signs of invasion, or diffuse. Expression of beta1 integrin decreased progressively from intraductal tumours without signs of invasion, to the diffuse type, in which immunolabelling was generally absent. In a few cases of diffuse neoplasia, groups of neoplastic cells exhibited strong positivity that was not restricted to the basal pole of the cell membrane. These results suggest that the expression of beta1 integrin was related to the histological tumour type, possibly reflecting a specific requirement for a reduction in integrin by neoplastic cells with infiltrative and metastatic potential.

Evaluation of angiogenesis in canine mammary tumors by quantitative platelet endothelial cell adhesion molecule immunohistochemistry

Angiogenesis was evaluated by immunohistochemistry for platelet endothelial cell adhesion molecule (CD31) in a series of benign and malignant canine mammary neoplasms. Computer image analysis was used to measure the intratumoral microvessel density (number of microvessels per square millimeter) and the area and perimeter of immunolabeled vascular structures. A higher intratumoral microvessel density and lower values for area and perimeter were found in malignant neoplasms compared with benign tumors and among the malignant tumors, in less differentiated phenotypes and in more anaplastic histological types (solid and squamous carcinomas), most of which had metastasized. These findings are consistent with an increase in angiogenesis in multistage neoplasia. Therefore, in more anaplastic malignant neoplasms, numerous but small and often malformed new vessels can be identified. The correlation of angiogenesis data with differentiation grade and histological type of mammary neoplasms is consistent with the findings in human medicine and demonstrates that angiogenesis can also have a prognostic value in veterinary medicine.

Primary hypothyroidism associated with leishmaniasis in a dog

A case of primary hypothyroidism associated with leishmaniasis is described in a four-year-old, male Yorkshire terrier. Clinical diagnosis of hypothyroidism was confirmed by a low baseline serum tetraiodothyronine (T4), a reduced response to thyroid-stimulating hormone (TSH) stimulation, an increased serum TSH concentration, and scintigraphic thyroid gland examination. Examination of a thyroid biopsy showed many Leishmania amastigotes, both inside and outside of macrophages, together with signs of follicular atrophy.

Ultrastructural and freeze fracture cilia morphology of trachea epithelium in apparently healthy small ruminants

Specimens of tracheal mucosa were obtained from ten adult apparently healthy small ruminants (five goats and five sheep) both by a fibre optic endoscope and in a slaughterhouse. Ultrastructurally, a total of 50,000 cilia were examined. Pathological cilia were found in all examined subjects. The prevalence of compound cilia showed a range of 0.3% to 3%. Intracytoplasmic and swollen cilia ranged from 0.2% to 0.5%. The microtubular pattern was examined in 4,000 cross-sectioned cilia and an abnormal pattern was found in 5-7%. Microtubular defects involved both peripheral and central doublets, being peripheral abnormalities the prevailing ones. A central plug of electron dense material was observed in 2-3% of the examined basal bodies. Rare basal bodies characterized by an abnormal spatial configuration were also shown. Freeze fracture studies revealed a ciliary necklace composed of 4 to 5 rows of intramembrane particles.

Immunohistochemical distribution of type IV collagenase in normal, dysplastic and neoplastic canine mammary gland

The distribution of type IV collagenase (cIVase) was evaluated immunohistochemically in a series of normal, dysplastic and neoplastic canine mammary glands, as well as in lymph node metastases. In normal and dysplastic mammary tissues, and benign mammary tumours, cIVase was observed in myoepithelial cells, but in malignant tumours it was mainly localized in the cytoplasm of carcinoma cells and fibroblasts close to infiltrating neoplastic cells. No significant difference was observed between carcinomas of different histological sub-types. These results suggest that the distribution of cIVase is a potentially useful indicator of malignancy in canine mammary tumours.

E cadherin expression in normal and neoplastic canine mammary gland

The epithelial intercellular adhesion molecule, E cadherin, was evaluated immunohistochemically in a series of normal and malignant neoplastic canine mammary glands. The normal glands showed strong immunolabelling at the intercellular borders of all the ductal cells. Tubular and papillary mammary adenocarcinomas had reduced intercellular E cadherin positivity with "heterogeneous" or "cytoplasmic" distribution. Solid and squamous cell carcinomas were negative. These results suggest that reduced expression and abnormal distribution of E cadherin may be related to the differentiation grade of these neoplasms.

Ciliary abnormalities in the tracheal epithelium of normal fallow deer (Dama dama)

Specimens of tracheal mucosa were obtained from seven 2- to 5-year-old healthy fallow deer by an Olympus GIF P20 fibroscope. Biopsies were performed in two selected areas in the upper and lower third, respectively. Ultrastructurally, a total of 50,000 cilia were examined. Pathological cilia were found in all examined subjects. The prevalence of compound cilia showed a range of 0.9 to 3.0%. The presence of both intracytoplasmatic and swollen cilia ranged from 0.1 to 0.2%. Furthermore, the microtubular pattern was examined in 5,000 cross-sectioned cilia. Microtubular defects were seen to involve only the peripheral doublets and ranged from 1.3 to 4.1%. Finally, a central plug of electron-dense material was observed in 7-10% of the examined basal bodies.

Expression of beta 1 integrin in normal, dysplastic and neoplastic canine mammary gland

The expression of beta 1 integrin was evaluated immunohistochemically in a series of normal, dysplastic and neoplastic canine mammary glands, and in lymph node metastases. The tissues were formalin-fixed and paraffin wax-embedded. In malignant neoplasms, beta 1 integrin was decreased and redistributed along the entire cell membrane. In lymph nodes, strong immunohistochemical staining was seen intercellularly in clusters of metastatic cells within subcapsular sinuses and at the periphery of intranodal metastases. These results suggest that the expression of integrin molecules may be related to malignancy and to the metastatic potential of neoplastic cells.

Silver-stained nucleolar (Ag-NOR) cluster size in feline mammary carcinomas: lack of correlation with histological appearance, mitotic activity, tumour stage, and degree of nuclear atypia

The relationship between Ag-NOR cluster size, mitotic index, tumour stage, degree of nuclear atypia and histological appearance was evaluated in a series of feline mammary carcinomas. The mean Ag-NOR cluster area per cell in these tumours ranged from 1.86 to 6.25 microns 2 and was not related to any other parameter studied. This suggests that Ag-NOR cluster size measurement is of poor diagnostic and prognostic value for feline mammary carcinomas.

Expression of proliferating cell nuclear antigen in basal cell carcinomas and in squamous cell carcinomas of canine skin: correlation with mitotic index and histological features

In this study we evaluated the behaviour of proliferating cell nuclear antigen labelling index (PCNA-LI), mitotic index (MI) and histological features in ten basal cell carcinomas (BCC) and ten squamous cell carcinomas (SCC) of canine skin. PCNA-LI ranged from 2.1% to 4.8% in SCC and from 0.1% to 2.0% in BCC samples. A significant statistical correlation, between PCNA-LI and MI could be demonstrated only in SCC, but not in BCC samples. Furthermore, PCNA-LI was also significantly and consistently greater in the three BCC of solid type and in poorly differentiated SCC. PCNA-LI may provide additional criterion in evaluating the intrinsic malignancy and growth potential of the above tumours.

Atypical cilia in the oviductal epithelium of healthy cats

Specimens of the uterine tube were obtained from ten healthy, ovario-hysterectomized cats. Ultrastructurally, a total of 66,000 cilia were examined. Atypical cilia were found in all examined subjects. The prevalence of compound cilia showed a range of 0.2% to 1.8%. Intracytoplasmic and swollen cilia ranged from 0.06% to 0.3% and from 0.03% to 0.3%, respectively. The microtubular pattern was examined in 7,000 cross-sectioned cilia and an abnormal pattern was found in 2.6%-6.5%. Abnormalities of peripheral microtubules were the prevailing defect. A central plug of electron-dense material was observed in 2-3% of the examined basal bodies. Several basal bodies characterized by an abnormal spatial configuration were also shown.

Evaluation of the cardiomyopathy in Becker muscular dystrophy

To evaluate the features and the course of cardiomyopathy in Becker muscular dystrophy, 68 patients--identified by clinical assessment and by reduced dystrophin labeling and/or DNA analysis--were followed in the years 1976-1993, for periods ranging from 3 to 18 years (mean 8). Patients periodically underwent clinical, electrocardiographic, echocardiographic, nuclear, and radiological assessments. Preclinical cardiac involvement was found in 67.4% of patients under 16 years of age, decreasing to 30% in patients older than 40. Clinically evident cardiomyopathy was found in 15% of patients under 16 years of age, increasing to 73% in patients older than 40. A real, dilated cardiomyopathy is the most frequent type of myocardial involvement after the age of 20. Results show that the severity of cardiac involvement can be unrelated to the severity of skeletal muscle damage and confirm that cardiac dysfunction is a primary feature of Becker muscular dystrophy.

Vitiligo in two water buffaloes: histological, histochemical, and ultrastructural investigations

Vitiligo, a skin disease, characterized by the spontaneous loss of melanin, has been described in several animals as well as in humans. Most of the reports of large domestic animals have dealt with clinical investigations without morphological data. In this report, the histological and ultrastructural characteristics of two cases of vitiligo in water buffaloes (Bubalus bubalis) are presented. Interestingly, many of the ultrastructural observations for vitiliginous buffaloes resemble those previously described for other species, e.g., humans, mouse, and chicken. These data suggest that one or more forms of human vitiligo may have a similar etiopathogenesis to that of the buffalo. Therefore, it is proposed that vitiliginous buffalo may prove to be a useful animal model for the human disease.

Ultrastructure of cilia in horses

This paper presents some ultrastructural details of cilia from the ciliated tracheal epithelium of healthy horses. By using a new fixation method, the Authors were able to describe minute details, some of which have been only rarely observed in other species and mostly by means of the freeze-etch technique (i.e. electron dense particles of ciliary necklace). The Authors justify the need to investigate the ultrastructural details of cilia in various species since the minute morphological differences might be functionally significant.

Atypical cilia in the tracheal epithelium of healthy horses

Specimens of the tracheal epithelium were obtained from two sites in nine healthy horses by a fibre optic endoscope. Electron microscopic examination of 53,550 cilia revealed that 5.2 per cent of cilia were atypical. Nine hundred and seventeen (1.7 per cent) were compound, 78 (0.15 per cent) were swollen, 27 (0.05 per cent) were intracytoplasmic and 171 (3.35 per cent) had microtubular defects. These microtubular defects (159 peripheral and 12 central) were found in 5103 cross-sectioned cilia.