Preliminary morphometrics of spleen and kidney macrophage aggregates in clinically normal blue gourami Trichogaster trichopterus and freshwater angelfish Pterophyllum scalare

Macrophage aggregate (MA) morphometry and pigment composition are believed to be dependent on the species, age, and health status of the fish. The aim of this study was to characterize a "normal" morphometry baseline of spleen and kidney MAs in blue gourami Trichogaster trichopterus and freshwater angelfish Pterophyllum scalare. Three size-classes of clinically normal fish were analyzed. Blue gourami and freshwater angelfish were obtained from three local ornamental fish farms; for each size-class, 10 fish from each farm were analyzed. Hematoxylin- and eosin-stained tissue sections were analyzed by light microscopy at 100x magnification and an image analysis program. The percentage of tissue occupied by MAs, MA size, and MA number were calculated on three arbitrarily selected fields of view from each spleen and kidney. In clinically normal blue gourami, increases in the percentage of tissue occupied by MAs and in MA size were associated with an increase in fish size, but in clinically normal angelfish no correlation was observed. Furthermore, in angelfish, a high variability in MA morphometry was observed, even among fish from the same sample group. In both species, a significant difference in the value of the morphometric parameters was observed among farms. Because iridoviruses inhibit macrophage activity and (possibly) proliferation, MAs in 25 clinical cases of iridovirus-infected blue gourami were analyzed. Preliminary data indicate that in iridovirus-infected blue gourami, there is a decrease in MA size and MA number compared with those of healthy fish.     

Differentiation and growth of myotomal muscles in a non-model tropical fish Pterophyllum scalare (Teleostei: Cichlidae)

Somite differentiation, muscle fibres formation and growth were analysed in a non-model tropical fish Pterophyllum scalare. In this study, it was found that during somite differentiation, a primary myotome appears. The primary myotome is filled with multinucleated myotubes that constitute the major part of the somite. Subsequently, Pax-3 (paired-box protein)-positive cells, located externally to the myotomes, appear. In post-hatching stages, mononucleated proliferating cell nuclear antigen-positive cells are observed in the inter-myotomal spaces and within the myotomes. The mononucleated cells, situated in the myotomes, first express desmin in their cytoplasm and then Pax-7 (paired-box protein) in their nuclei. Expression of desmin indicates that they will enter myogenic pathway, whereas expression of Pax-7 suggests their role of satellite cells. We assume that mononucleated intramyotomal cells are myogenic precursors involved in muscle growth. In advanced (post-hatching) stages of myogenesis, myotomes contain both primary and new muscle fibres. Morphometric analyses show that in Pterophyllum scalare, growth of muscle fibres is mainly a result of hypertrophy.     

Preliminary Morphometrics of Spleen and Kidney Macrophage Aggregates in Clinically Normal Blue Gourami Trichogaster trichopterus and Freshwater Angelfish Pterophyllum scalare

Abstract

Macrophage aggregate (MA) morphometry and pigment composition are believed to be dependent on the species, age, and health status of the fish. The aim of this study was to characterize a “normal” morphometry baseline of spleen and kidney MAs in blue gourami Trichogaster trichopterus and freshwater angelfish Pterophyllum scalare. Three size-classes of clinically normal fish were analyzed. Blue gourami and freshwater angelfish were obtained from three local ornamental fish farms; for each size-class, 10 fish from each farm were analyzed. Hematoxylin- and eosin-stained tissue sections were analyzed by light microscopy at 100× magnification and an image analysis program. The percentage of tissue occupied by MAs, MA size, and MA number were calculated on three arbitrarily selected fields of view from each spleen and kidney. In clinically normal blue gourami, increases in the percentage of tissue occupied by MAs and in MA size were associated with an increase in fish size, but in clinically normal angelfish no correlation was observed. Furthermore, in angelfish, a high variability in MA morphometry was observed, even among fish from the same sample group. In both species, a significant difference in the value of the morphometric parameters was observed among farms. Because iridoviruses inhibit macrophage activity and (possibly) proliferation, MAs in 25 clinical cases of iridovirus-infected blue gourami were analyzed. Preliminary data indicate that in iridovirus-infected blue gourami, there is a decrease in MA size and MA number compared with those of healthy fish.     

Cerebral vascular hamartomas in five dogs

Vascular hamartomas are considered developmental lesions rather than true neoplasms. Reports of such anomalies in the canine brain are scarce, and their classification is confusing. This case series of vascular hamartomas from the brains of five dogs was characterized using histochemistry and immunohistochemistry, in addition to gross and microscopic findings. All five hamartomas were located in the telencephalon, three in the pyriform lobe, without any predilection for the left or right side. Each hamartoma consisted of a proliferation of thin-walled vessels which varied in caliber. These vessels were elastin-negative, with varying amounts of collagen and no muscular component. In four of the five hamartomas, lining cells were actin- and factor VIII-positive. All five hamartomas contained glial fibrillary acid protein (GFAP)-positive parenchyma at moderate to high frequency, and four contained neurofilament-positive axons between component vessels. This report shows that vascular hamartomas in the canine brain are structural malformations for which immunohistochemistry is useful for accurate classification.     

Matrix metalloproteinases (MMPs) activity in cultured canine bone marrow stromal cells (BMSCs)

Autologous bone marrow stromal cells (BMSCs) infusion therapy improves the hepatic fibrosis. To investigate the mechanism of remission, we evaluated the matrix metalloproteinase (MMP)-2 and -9 activity in canine BMSCs and the effect of pro-inflammatory cytokines on their expression. The activity and the gene expression of MMPs were analyzed by gelatin zymography and quantitative RT-PCR, respectively. The specific gelatinase bands were indicative effect of MMP-2 and -9 in canine BMSCs. MMP-2 expression seemed to be increased by TNF-α and IL-1β while MMP-9 was enhanced by TNF-α and IL-6. These results suggested that remissive effect on liver fibrosis might be partly attributable to the MMP-2 and -9 activity in BMSCs under the inflammatory condition.     

Epitheliocystis disease in cultured pacu (Piaractus mesopotamicus) in Brazil.

Epitheliocystis disease was diagnosed in a cultured pacu (Piaractus mesopotamicus Holmberg, 1893) stock on the basis of gross pathological (greyish-white, pinpoint- or pinhead-sized focal areas, connected strongly to the gill lamellae) and histopathological examinations (hypertrophic cells 10-40 microns in size, having a well-defined wall and a central inclusion or characteristic granular content stained with Giemsa). The disease did not occur among fishes (Cyprinus carpio L., Ctenopharyngodon idella Cuv. and Val., Sarotherodon mosambicus Peters, Hoplias malabaricus Bloch) kept together with the affected pacus. About 30-40% of the pacu stock succumbed. Since branchial lesions and heavy mortality were observed in this pacu population, the aetiological role of the epitheliocystis agent could be suspected. Based upon ultrastructural examinations this agent is considered to be a chlamydia or a chlamydia-like organism.     

Chondromatous hamartomas of the respiratory tract in the dog

Three chondromatous hamartomas of the trachea associated with dyspnoea, and a similar lesion of the bronchus associated with coughing, were recognized in four dogs, and diagnosed on radiological and histopathological examination. These benign lesions were surgically removed. The dogs remained well after surgery for periods up to four years.     

Pharmacokinetics of amoxicillin trihydrate in cultured olive flounder (Paralichthys olivaceus)

The study was aimed at investigating the pharmacokinetics of amoxicillin trihydrate (AMOX) in olive flounder (Paralichthys olivaceus) following oral, intramuscular, and intravenous administration, using high‐performance liquid chromatography following. The maximum plasma concentration (C_max), following oral administration of 40 and 80 mg/kg body weight (b.w.), AMOX was 1.14 (T_max, 1.7 h) and 0.76 μg/mL (T_max, 1.6 h), respectively. Intramuscular administration of 30 and 60 mg/kg of AMOX resulted in C_max values of 4 and 4.3 μg/mL, respectively, with the corresponding T_max values of 29 and 38 h. Intravenous administration of 6 mg/kg AMOX resulted in a C_max of 9 μg/mL 2 h after administration. Following oral administration of 40 and 80 mg/kg AMOX, area under the curve (AUC) values were 52.257 and 41.219 μg/mL·h, respectively. Intramuscular 30 and 60 mg/kg doses resulted in AUC values of 370.274 and 453.655 μg/mL·h, respectively, while the AUC following intravenous administration was 86.274 μg/mL·h. AMOX bioavailability was calculated to be 9% and 3.6% following oral administration of 40 and 80 mg/kg, respectively, and the corresponding values following intramuscular administration were 86% and 53%. In conclusion, this study demonstrated high bioavailability of AMOX following oral administration in olive flounder.     

Multiple congenital epitrichial sweat gland hamartomas in a piglet

A case of multiple congenital epitrichial sweat gland hamartomas in a 2-day-old piglet is presented. The skin lesions were raised, ovoid to linear in configuration, alopecic, red-purple to pink, and cauliflower-like to cerebriform in appearance. Histological examination of skin specimens confirmed a diagnosis of epitrichial sweat gland hamartoma. Complete necropsy examination revealed no other lesions.     

Heterosporis anguillarum infections in farm cultured eels (Anguilla japonica) in Korea

Ten eels (Anguilla japonica) from a fish farm in Korea were examined and diagnosed with a Heterosporis infection. The gross lesions on the trunk were uneven and the concave parts were pasty. Histopathologically, lyses of the trunk muscles, degenerative muscle fibers and the scattered spores were observed. The sporophorocyst (SPC) contained several spores with a variety of shapes. Some SPC were disrupted and the spores in the SPC were scattered in the muscle tissues. Macrophages existed near the scattered spores. Electron microscopy revealed special structures such as sporophorocyst containing various developmental parasitic stages such as meronts, sporonts, sporophorous vesicles and spores.     

"Lipomatous" hamartomas and choristomas in inbred laboratory mice

In a retrospective study, 37 male and 19 female inbred laboratory mice, from 1 to 36 weeks of age, were diagnosed with "lipomatous" hamartomas or choristomas from nearly 10,000 mice examined at necropsy over a 24-month period. Hamartomas and choristomas were found to be rare, noninherited tumor-like conditions that occurred spontaneously in 18 inbred strains of mice with a predominance of the conditions in the C3H/HeJ and C57BL/6J strains. Prevalence between strains ranged from 0.6 to 6.2 cases per hundred thousand mice. The 56 cases studied had soft, raised masses that arose on the dorsal midline, primarily above the sutures of the skull. The lesions were prominent on gross examination due to abnormally long hair, change in direction of the hairs, and a change in hair color compared to the normal pelage. Microscopically, the masses consisted of normal adipose tissue in the reticular dermis and subcutis that sometimes extended through the cranial sutures, entering the brain, or expanding into the ventricles. Large masses occasionally contained normal appearing thyroid, intestine, respiratory epithelium lined cysts, squamous epithelial cysts, bone and marrow, cartilage, glands, and angiomatous anomalies. In all cases, the epidermis was intact. Hair follicles were larger in the affected areas of many cases compared to those in adjacent skin. Breeding studies did not yield affected offspring, indicating this is a congenital, noninherited abnormality. This condition resembles "lipomatous" hamartomas, a congenital defect in human beings.