A new species of coccidia of the red kangaroo Macropus Rufus Mamm

Summary A new species of Eimeria, E. rufusi, is described from the red kangaroo Macropus rufus Mamm.With 4 Figures in the Text     

Plastic casts and confocal laser scanning microscopy applied to the observation of enamel tubules in the red Kangaroo (Macropus rufus)

Scanning electron microscopy for plastic casts and confocal laser scanning microscopy for Villanueva bone-stained ground sections were used together to observe enamel tubules in red kangaroo molars. Although the tubular structures such as terminals, bends, expansions, splits, divergences and rejoinings in this species were within the variations of marsupial species, their morphological characteristics were demonstrated with extremely clear and persuasive images. Thus, the combined observations of plastic casts by scanning electron microscopy and Villanueva bone-stain sections by confocal laser scanning microscopy were found to be of value for the investigation of enamel tubules and tubular structures in other hard tissues.     

Histology and immunohistochemistry of the gut-associated lymphoid tissue of the eastern grey kangaroo, Macropus giganteus

Mesenteric lymph nodes and gut-associated lymphoid tissue (GALT) from juvenile eastern grey kangaroos were investigated. The mesenteric nodes had a similar structure to that described for eutherian mammals. They contained distinct regions of medulla and cortex, with prominent follicles and germinal centres. Gut associated lymphoid tissue consisted of areas of submucosal follicles. These varied from areas of densely packed lymphocytes with darkly staining, prominent coronas to areas with no defined follicles. The distribution of T cells in these tissues was documented by use of species-crossreactive antibodies to the surface markers CD3 and CD5; B cells were identified by antibodies to CD79b. Within the lymph nodes T cells were located mainly in the paracortex and cortex, with limited numbers observed in the follicles; B cells were located on the marginal zone of the follicles. In GALT, T cells were located in the peripheral regions of the germinal centres of secondary follicles, while B cells were abundant in primary follicles. These observations are consistent with those made in a range of other marsupials (metatherian) and eutherian mammals and are indicative of the capacity to respond to antigens entering via the mouth.     

Scaling of the ankle extensor muscle‐tendon units and the biomechanical implications for bipedal hopping locomotion in the post‐pouch kangaroo Macropus fuliginosus

Bipedal hopping is used by macropods, including rat‐kangaroos, wallabies and kangaroos (superfamily Macropodoidea). Interspecific scaling of the ankle extensor muscle‐tendon units in the lower hindlimbs of these hopping bipeds shows that peak tendon stress increases disproportionately with body size. Consequently, large kangaroos store and recover more strain energy in their tendons, making hopping more efficient, but their tendons are at greater risk of rupture. This is the first intraspecific scaling analysis on the functional morphology of the ankle extensor muscle‐tendon units (gastrocnemius, plantaris and flexor digitorum longus) in one of the largest extant species of hopping mammal, the western grey kangaroo Macropus fuliginosus (5.8–70.5 kg post‐pouch body mass). The effective mechanical advantage of the ankle extensors does not vary with post‐pouch body mass, scaling with an exponent not significantly different from 0.0. Therefore, larger kangaroos balance rotational moments around the ankle by generating muscle forces proportional to weight‐related gravitational forces. Maximum force is dependent upon the physiological cross‐sectional area of the muscle, which we found scales geometrically with a mean exponent of only 0.67, rather than 1.0. Therefore, larger kangaroos are limited in their capacity to oppose large external forces around the ankle, potentially compromising fast or accelerative hopping. The strain energy return capacity of the ankle extensor tendons increases with a mean exponent of ~1.0, which is much shallower than the exponent derived from interspecific analyses of hopping mammals (~1.4–1.9). Tendon safety factor (ratio of rupture stress to estimated peak hopping stress) is lowest in the gastrocnemius (< 2), and it decreases with body mass with an exponent of −0.15, extrapolating to a predicted rupture at 160 kg. Extinct giant kangaroos weighing 250 kg could therefore not have engaged in fast hopping using ‘scaled‐up’ lower hindlimb morphology of extant western grey kangaroos.     

Masticatory muscles of the great‐gray kangaroo (Macropus giganteus)

The great‐gray kangaroo (Macropus giganteus) belongs to the Diprotodontia suborder (herbivorous marsupials of Australia) of the order of marsupials. We dissected the masticatory muscles in the great‐gray kangaroo and classified them based on their innervation. Three (two male and one female) adult great‐gray kangaroos (M. giganteus), fixed with 10% formalin, were examined. The masseter muscle of the great‐gray kangaroo was classified into four layers (superficial layers 1, 2, 3, and a deep layer), all innervated by masseteric nerves. Layer 1 of the masseter muscle was well developed and the deep layer inserted into the masseteric canal. The zygomaticomandibular muscle, which belongs to both the masseter and temporalis muscles, was innervated by both the masseteric nerve and posterior deep temporal nerve, and the temporalis muscle was innervated by the anterior and posterior deep temporal nerves. The medial pterygoid muscle, which was innervated by the medial pterygoid nerve, was divided into superficial and deep portions. The lateral pterygoid muscle was divided into superior and inferior heads by the buccal nerve. We propose that the relationship of the masticatory muscles in the kangaroo has evolved by passive anterior invasion of the deep layer of the masseter by the medial pterygoid muscle via the masseteric canal, associated with the development of an anteroposterior mode of mastication. Anat Rec 2007. © 2007 Wiley‐Liss, Inc.     

Olfactory function in the Red Kangaroos (Macropus rufus) assessed using odor-cued taste avoidance.

Each of six kangaroos, tested in a seminatural environment. learned to respond readily to water and to sniff at but not ingest an aqueous solution of 0.1% isoamyl acetate plus 0.5% quinine. Avoidance of the odor stimulus typically occurred after licking at the solution on two to three trials for most subjects. Kangaroos also learned to avoid lower concentrations of isoamyl acetate and to discriminate between isoamyl acetate and ethyl acetate. These results are among the first to document olfactory function in kangaroos. The odor-cued taste-avoidance procedure provides a relatively simple test of olfaction that can be used in the field with open-range animals.     

Postnatal development of orexin-A and orexin-B like immunoreactivities in the Eastern grey kangaroo (Macropus giganteus) hypothalamus

The Eastern grey kangaroo (Macropus giganteus) is a marsupial, which is born in an extremely undeveloped state and has a long suckling period in the mother's pouch. In the present study, we examined the immunoreactivities of orexin-A (OXA) and orexin-B (OXB) in the hypothalamus of the Eastern grey kangaroo during the preweaning period, postweaning period and adulthood. In the preweaning period, only a few OXA- and OXB-like immunoreactive (LI) neurons and fibers were present and the intensity of staining was very weak. In the postweaning period, there was a pronounced increase in the numbers of OXA- and OXB-LI neurons and fibers and the intensity of the immunoreactivity was considerably stronger in comparison to the preweaning period. In the adult, the numbers of OXA- and OXB-LI neurons and fibers appeared to be slightly increased and the intensity was slightly stronger in comparison to the postweaning period. At all time periods, the distributions of OXA- and OXB-LI neurons was similar. The postnatal development of hypothalamic orexin neurons may be associated with developmental changes, including feeding behavior.     

Histological and electron microscopic milestones in the development of the retina of a marsupial wallaby, Macropus eugenii

Summary Retinal differentiation in the pouch young of the wallaby Macropus eugenii was characterized microscopically and morphometrically. Mitosis occurs until early in the second month in the central retina, and until early in the fourth month, peripherally. Separation of the neuroblast layer by the outer plexiform layer did not immediately halt cell division. The retinal surface continued to expand well past the time of cessation of proliferation. Cell death in the ganglion cell layer continued through the fourth month centrally and to nearly five months in the periphery. The major period of cell death was coincident with the segregation of retinal afferents and the refinement of topography in the superior colliculus and dorsal lateral geniculate necleus. Beginning in the third month retinal thickness, measured between the outer limiting membrane and nerve fiber layer declined equally in peripheral and central regions. At all stages the combined thicknesses of the outer and inner nuclear layer in the retinal periphery was greater than that in the center. Together with a late thickening of the inner plexiform layer, the data are consistent with the suggestion that expansion of peripheral non-ganglion cell elements may play a role in development of center to periphery differences in ganglion cell distributions.Retinal differentiation of the wallaby follows the pattern of most mammals. The onset of development of key milestones for the acquisition of retinal function occurred in the sequence: conventional synapse formation prior to ribbon synapse formation in the inner plexiform layer, and photoreceptor outer segment differentiation prior to terminal triad synapse formation.     

Histological regression in primary cutaneous melanoma: recognition, prevalence and significance

Five hundred and sixty-three primary cutaneous melanomas were assessed for the presence of histological regression in relation to the thickness of the lesion and features such as sex, anatomical location and clinical outcome. Regression was more common in thin lesions, being seen in 46% of thin (less than 1.5 mm) lesions, 32% of intermediate (1.5-3.0 mm) lesions and 9% of thick (greater than 3.0 mm) lesions. However, severe regression was only identified in 6.5% of thin lesions, 5.2% of intermediate lesions and 1.5% of thick melanomas. Regression was more common in superficial spreading melanomas and in lesions from the trunk and lower limb. Moderate and severe regression were seen slightly more often in men. Clinical follow-up, although not of statistical significance, suggests that regression in thin lesions is a sinister histological feature.     

Histological grading of breast cancer. Interobserver, reproducibility and prognostic significance

A study was conducted to assess the reproducibility and prognostic significance of the histopathological grading by using the criteria of Bloom and Richardson. 166 breast carcinomas of the invasive ductal type (NOS - not otherwise specified) according to the WHO criteria, selected from the biopsy material of the years 1980 to 1988 were investigated. 85 of the patients presented axillary lymph node metastases in the mastectomy specimens. A satisfactory correlation of histopathological grades assessed by three pathologists was found in 72.3% of all cases. Fifteen cases (9%) were over- and 31 cases (18.7%) were underestimated compared with an expert's grade. A disagreement of two grades occurred in one case only. In comparison of grade 1 and grade 3 tumours as well as of grade 2 and grade 3 tumours significant differences in the overall survival could be found. Irrespective of statistically significant differences between the three grades in actuarial survival, the histopathological grading is of rather low value for the prediction of prognosis of individual patients.     

Histological variants of prostatic carcinoma and their significance

The vast majority of prostatic cancers are acinar adenocarcinomas. Histological variants of prostatic carcinoma have been variably defined. One approach is to consider two groups of variants. The first group comprises histological variants of acinar adenocarcinoma and the second group non-acinar carcinoma variants or types. Variants of usual acinar adenocarcinoma defined in 2004 by the World Health Organization (WHO) include atrophic, pseudohyperplastic, foamy, colloid, signet ring, oncocytic and lymphoepithelioma-like carcinomas. The second group of non-acinar carcinoma histological variants or types of prostatic carcinoma accounts for about 5-10% of carcinomas that originate in the prostate. These include sarcomatoid carcinoma, ductal adenocarcinoma, urothelial carcinoma, squamous and adenosquamous carcinoma, basal cell carcinoma, and neuroendocrine tumours, specifically small-cell carcinoma. Recently characterized variants not present in the 2004 WHO classification, including microcystic adenocarcinoma, prostatic intraepithelial neoplasia-like adenocarcinoma, large-cell neuroendocrine carcinoma, and pleomorphic giant cell carcinoma, are also described. The aims of this review are to present the essential histomorphological diagnostic attributes of these variants, and to emphasize the clinical signficance of the variants, when different from usual acinar adenocarcinoma, including clinical presentation and outcome.     

Histological, immunohistochemical and biological data in assessing interstitial fibrosis in patients with chronic glomerulonephritis

The aim of this study was to determine the relationship between histological, immunohistochemical (IHC) and biological data in the assessment of interstitial fibrosis in patients with glomerular diseases. A group of 41 patients with primary and secondary glomerulonephritis was studied. In order to quantify the histological changes and to assess the extent of active-inflammatory and chronic-sclerotic/fibrotic interstitial lesions, we adapted a scoring system, initially used for lupus nephritis, and ANCA-associated vasculitis. IHC labeling procedures with monoclonal antibodies anti-smooth muscle actin (SMA), anti-vimentin and anti-transforming growth factor beta (TGFbeta) were assessed using a semi-quantitative score, correlated with the histological and biological data. Our results showed that interstitial labeling of SMA correlated with scores for sclerotic/fibrotic lesions (chronicity index) and with active-inflammatory lesions (interstitial infiltrate, activity index). Interstitial vimentin correlated with the score for interstitial infiltrate. Both interstitial vimentin and TGFbeta immunopositivity correlated with sclerotic/fibrotic lesions (interstitial fibrosis, tubular atrophies, vascular hyalinosis/fibrosis, chronicity index), and negatively with glomerular filtration rate. An important correlation was found between the interstitial labeling of the two IHC markers of myofibroblasts (SMA and vimentin). We conclude that IHC studies related to clinico-biological and histological data can have an important role in the evaluation of the glomerular diseases, but the classical histological investigation assessed through quantification has still not lost its importance.     

Histological types and significance of bronchial epithelial dysplasia.

Pulmonary epithelium is known to undergo a preneoplastic process prior to the development of lung carcinoma. Squamous dysplasia and atypical adenomatous hyperplasia have been identified and classified as preinvasive lesions of squamous cell carcinoma and peripheral pulmonary adenocarcinoma, respectively. However, these commonly recognized preinvasive lesions do not completely explain the development of all histological types of lung carcinoma. By examining 114 resection lung specimens, we concluded that there are four histological patterns of bronchial epithelial dysplasia based on morphological features (basal cell dysplasia, columnar cell dysplasia, bronchial epithelial dysplasia with transitional differentiation, and squamous dysplasia). The histological patterns were further characterized by immunohistochemistry. Basal cell dysplasia was focally positive for cytokeratin (CK) 17 and 10/13; columnar cell dysplasia was generally positive for CK7, 8, and 18; bronchial epithelial dysplasia with transitional differentiation had a heterogeneous immunoprofile, while squamous dysplasia was positive for CK10/13 and focally positive for CK17. Various degrees of abnormal expression of p53 and Ki-67 were found in the different types of bronchial epithelial dysplasia. The cases were divided into three groups based on degree and extent of bronchial epithelial dysplasia. By Crosstabs McNemar test, the Mann-Whitney U-test (for two independent groups), the Kruskal-Wallis one-way nonparametric ANOVA (for >2 independent groups) and Spearman correlation analysis, the degree and extent of bronchial epithelial dysplasia was shown to be positively correlated with the incidence of bronchogenic carcinoma and multifocal primary lung carcinoma (P<0.05). These findings indicated the following: (1) bronchial epithelium can develop various patterns of dysplasia with abnormal/ambiguous cell differentiation and abnormal expressions of p53 and Ki-67. Thus, these bronchial epithelial dysplastic lesions may represent a preneoplastic process. (2) The degree of bronchial epithelial dysplasia may significantly predispose individuals to bronchogenic carcinoma and multifocal primary lung carcinoma.     

Diptera infestation of the carcasses of Arion rufus (Gastropoda) and its possible hygienic significance

Salmonellas of different serotypes and eggs of the helminths Ascaris lumbricoides L. and Trichuris trichiura L. were discovered in excrements, on the body surface and also on dead bodies on the gastropod Arion rufus L., which is partly coprophagous. Dipterans visiting such substrate may become--probably at most indirectly--vectors of these parasites and may be injurious to the health of men and domestic animals. By traps with carcasses of Arion as baits 178 species of Dipterans of 29 families were caught, among them species known as vectors and nearly all families in which species of vector function are stated. Investigation of foodstuffs and fodder revealed the occurrence of 144 of the 178 species of Dipterans stated on carcasses of Arion, mostly visitors on foodstuffs. Many of them may have vector function due to their chains of infestation. Informations are given on the spectrum of infection with salmonellae-serotypes and species of helminths stated on Arion and on the importance of Dipterans in the destruction of small carcasses. The results suggest the necessity of complementary investigations on the occurrence of further parasites on carcasses of gastropods.