Melanose talâmica em caprinos / Thalamic melanosis in goats

Background: Melanosis is a blackened pigmentation resulting from the accumulation of melanocytes in tissues that are not normally pigmented. This change in the color of the organs occurs due to the agglomeration of melanocytes originating from abnormal migration during embryogenesis and does not cause dysfunction to the affected organ. Although melanosis frequently occurs in several species and affects several organs such as the brain and spinal cord leptomeninges, involvement in the thalamus region is unusual. The objective of this work was to report 2 cases of thalamic melanosis in goats, determining the pathological and histochemical aspects that assist in the diagnosis of this condition. Cases: Two cases of thalamic melanosis in goats were diagnosed. In both cases, the animals had no nervous history disease and clinical signs. The cause of death in cases 1 and 2 was established based on anatomopathological findings and clinical signs being diagnosed with mycoplasmosis and asphyxia, respectively. After fixing and making cross-sections of the brain, a focal lengthy blackened area was observed on the thalamus surface in both cases. Microscopically, lesions in the brain were similar in both cases and exclusively affected the thalamus. These cells had abundant cytoplasm, well delimited with brownish granular pigment. The nuclei were difficult to visualize and in some cells, it was rounded, well-defined, morphologically compatible with melanocytes. Melanocytes were mainly distributed around neurons and often distended the perivascular space of multiple blood vessels. In Fontana Masson staining, the granules in the cytoplasm of these cells stained strongly black. The Prussian Blue, Periodic Acid- Schiff's, Von Kossa, and Giemsa stains were negative, and the pigment remained brown. In the unstained slides, assembled after the deparaffinization and clarification process, it was observed the permanence of cells with blackish-brown pigment in the cytoplasm. In immunohistochemistry, strong immunostaining of pigmented cells with the Anti-MelanA antibodies was observed in both cases. Discussion: The diagnosis of thalamic melanosis in goats was carried out based on the characteristic pathological findings, in which melanin pigments were demonstrated and identified through HE, Fontana-Masson staining, and unstained slides and confirmed by the IHC. The use of complementary histochemical techniques was fundamental for the classification of the pigment as melanin, demonstrating to be an accessible and reliable tool for the diagnosis of pathological processes that lead to the accumulation of pigments and or material in the tissues. The occurrence of melanin in the thalamus may be associated with a failure in the migration of melanoblasts, which would go to the optical pathways or to the thalamus. This erratic migration of melanoblasts can be explained by the fact that the forebrain is the embryogenic origin of the optic and diencephalon pathways. Macroscopically, thalamic melanosis must be differentiated mainly from neoplastic processes such as melanoma and hemangiosarcoma, pigmented fungus infections, Phalaris angusta poisoning, listeriosis, neurocutaneous melanosis, and neuromelanin. It was concluded that thalamic melanosis is an uncommon alteration in goats and although it has been diagnosed as an incidental necropsy finding, should be included in the differential diagnosis of diseases that affect the central nervous system, especially those that have a color change associated with the deposition of pigments in the tissues.

A flock level analysis of an outbreak of natural border disease in Sakiz ewes and their progeny

Background: Pestiviruses cause economically important diseases in domestic ruminants worldwide. Border Disease is a congenital viral infection of sheep, caused by a pestivirus, and is first reported in the Border region of Wales and England. The BDV has worldwide distribution in sheep with different prevalences among countries. Vertical transmission is an important route in the epidemiology of this virus. Infection of fetuses may cause birth of persistently infected lambs, that are viremic, antibody negative, and are excreting virus. The disease is characterized by abortion, barren ewes, stillbirth and persistently infected weak lambs showing neurological and dermatological signs. The economic importance of the disease is related to reproductive failure, abortions and significantly low survival rate of affected lambs. In the present study the aim was to describe clinical, hematological and serological aspects of natural Border disease virus (BDV) infection in a sheep flock in Cine, Aydin. Besides we sought to elucidate the relationship between natural (active infection) and persistent BDV disease and the serum concentration of haptoglobin (Hp) and serum amyloid A (SAA) in infected sheep Materials, Methods & Results: Field observations were carried out in a sheep flock comprising 327 sheep with a history of an outbreak abortion in Cine town in Aydin, Turkey. Twenty-five out of 327 sheep in the flock was monitorized by blood sampling. The animals were selected among aborted ones, at least once, into two weeks preceeding period or with a history of weak lambing. BDV antigen (persistent infection) was detected in 8 out of 25 sheep (32%) while antiviral antibodies (active infection) were detected in 18 animals tested (68%). The disease was mainly characterized by abortions, stillbirth/weak lamb and abnormal brown/black fleece pigmentation, which occurred in an epidemic form. Twenty five sheep were related to disease condition as detected serologically, and the ratio of the number affected to number at risk being was 17:8. The culling rate was 50% of the affected animals. Most of the affected animals were second lambing sheep (5/25, 20%). Hematological variables did not reveal statistical difference whereas serum concentrations of Hp (P < 0.05) and SAA (P < 0.01) were significantly higher in naturally infected sheep in contrast to persistently infected sheep with BDV. Discussion: Clinical signs and detailed laboratory analysis related to natural Border disease outbreak have never been reported in Turkey, although previous epidemiological studies had shown that Border disease virus infection is relatively common in some parts of Turkey in sheep flocks and persistent Border disease virus infection had been described in apparently healthy sheep in Turkey. In the present study the disease was mainly characterized by abortions, stillbirth/weak lamb and abnormal brown/black fleece pigmentation, which occurred in an epidemic form. Besides bronchopneumonia, enteritis and conjunctivitis were detected in a limited population. Neurological signs were only observed in 2 animals. Besides persistent infection was detected in 32% of sheep enrolled. An acute phase reaction involving Hp and SAA has been identified in the present study. These results indicate that the monitoring of selected acute phase proteins may increase the diagnostic information available as a result of their analyses in naturally infected sheep and persistently infected sheep with BDV.

A flock level analysis of an outbreak of natural border disease in Sakiz ewes and their progeny

Background: Pestiviruses cause economically important diseases in domestic ruminants worldwide. Border Disease is a congenital viral infection of sheep, caused by a pestivirus, and is first reported in the Border region of Wales and England. The BDV has worldwide distribution in sheep with different prevalences among countries. Vertical transmission is an important route in the epidemiology of this virus. Infection of fetuses may cause birth of persistently infected lambs, that are viremic, antibody negative, and are excreting virus. The disease is characterized by abortion, barren ewes, stillbirth and persistently infected weak lambs showing neurological and dermatological signs. The economic importance of the disease is related to reproductive failure, abortions and significantly low survival rate of affected lambs. In the present study the aim was to describe clinical, hematological and serological aspects of natural Border disease virus (BDV) infection in a sheep flock in Cine, Aydin. Besides we sought to elucidate the relationship between natural (active infection) and persistent BDV disease and the serum concentration of haptoglobin (Hp) and serum amyloid A (SAA) in infected sheep Materials, Methods & Results: Field observations were carried out in a sheep flock comprising 327 sheep with a history of an outbreak abortion in Cine town in Aydin, Turkey. Twenty-five out of 327 sheep in the flock was monitorized by blood sampling. The animals were selected among aborted ones, at least once, into two weeks preceeding period or with a history of weak lambing. BDV antigen (persistent infection) was detected in 8 out of 25 sheep (32%) while antiviral antibodies (active infection) were detected in 18 animals tested (68%). The disease was mainly characterized by abortions, stillbirth/weak lamb and abnormal brown/black fleece pigmentation, which occurred in an epidemic form. Twenty five sheep were related to disease condition as detected serologically, and the ratio of the number affected to number at risk being was 17:8. The culling rate was 50% of the affected animals. Most of the affected animals were second lambing sheep (5/25, 20%). Hematological variables did not reveal statistical difference whereas serum concentrations of Hp (P < 0.05) and SAA (P < 0.01) were significantly higher in naturally infected sheep in contrast to persistently infected sheep with BDV. Discussion: Clinical signs and detailed laboratory analysis related to natural Border disease outbreak have never been reported in Turkey, although previous epidemiological studies had shown that Border disease virus infection is relatively common in some parts of Turkey in sheep flocks and persistent Border disease virus infection had been described in apparently healthy sheep in Turkey. In the present study the disease was mainly characterized by abortions, stillbirth/weak lamb and abnormal brown/black fleece pigmentation, which occurred in an epidemic form. Besides bronchopneumonia, enteritis and conjunctivitis were detected in a limited population. Neurological signs were only observed in 2 animals. Besides persistent infection was detected in 32% of sheep enrolled. An acute phase reaction involving Hp and SAA has been identified in the present study. These results indicate that the monitoring of selected acute phase proteins may increase the diagnostic information available as a result of their analyses in naturally infected sheep and persistently infected sheep with BDV.(AU)

Cytological characterization of an Aspergillus nidulans mutant from a strain with chromosomic duplication

A development mutant, named V103, was obtained spontaneously from the A strain of A. nidulans. The A strain contains a duplicated segment of chromosome I that has undergone translocation to chromosome II (I II). It is mitotically unstable and generates phenotypically deteriorated types, some with enhanced stability. The deteriorated variants of A. nidulans show abnormal development, exhibiting slower colony growth, variations in colony pigmentation and changes in conidiophore structure. The alterations observed in the conidiophore include fewer metulae and phialides, further elongation and ramification of these structures, delayed nuclear migration and the presence of secondary conidiophores.

Ambicolored specimens of the flounder Paralichthys orbignyanus (Pleuronectiformes: Paralichthyidae)

Two ambicolored specimens of Paralichthys orbignyanus were reported for the estuarine area of the arroyo Pando (Uruguay). One of the specimens showed an almost fully coloration on the blind side, excepting the cephalic region, while the other one was partially pigmented. This is the first record of ambicoloration in P.orbignyanus.

Dois espécimes anficoloridos de Paralichthys orbignyanus foram coletados na área estuarina do arroyo Pando (Uruguai). Ambos apresentam pigmentação completa no lado oculado. Um deles, no entanto, exibe coloração em quase toda a extensão do lado cego, com exceção da região cefálica. O outro exemplar tem pigmentação desde a nadadeira caudal até a metade do corpo. Este é o primeiro registro desta anomalia na espécie P. orbignyanus.

Ambicolored specimens of the flounder Paralichthys orbignyanus (Pleuronectiformes: Paralichthyidae)

Two ambicolored specimens of Paralichthys orbignyanus were reported for the estuarine area of the arroyo Pando (Uruguay). One of the specimens showed an almost fully coloration on the blind side, excepting the cephalic region, while the other one was partially pigmented. This is the first record of ambicoloration in P.orbignyanus.

Dois espécimes anficoloridos de Paralichthys orbignyanus foram coletados na área estuarina do arroyo Pando (Uruguai). Ambos apresentam pigmentação completa no lado oculado. Um deles, no entanto, exibe coloração em quase toda a extensão do lado cego, com exceção da região cefálica. O outro exemplar tem pigmentação desde a nadadeira caudal até a metade do corpo. Este é o primeiro registro desta anomalia na espécie P. orbignyanus.