Histochemical and immunohistological approach to comparative neuromuscular diseases.

The broad category of neuromuscular diseases covers conditions that involve the weakness or wasting of the body muscles. These problems may occur in the spinal cord, the peripheral nerves or the muscle fibers. Some may be hereditary, while others are acquired. Commonly recognized conditions fall into the categories of myopathies, which are diseases of the muscle like muscular dystrophy, disorders of the junction where the nerve impulses are transmitted to the muscle like myasthenia gravis, and neuropathies, which are diseases of the peripheral nervous system. The diagnosis of most neuromuscular diseases rest on careful clinical evaluation of the patient, electromyography, the muscle biopsy, and in some instances, molecular genetic studies. Muscle biopsy, associated to histochemical and immunohistological techniques, plays a key role in diagnosis of many neuromuscular disorders. A number of morphological abnormalities of muscle can be recognized on histological stains such as haematoxylin and eosin and Engel trichrome. Histochemical techniques are essential for the study of muscle biopsies for four main reasons. First, they demonstrate the non-uniform nature of the muscle highlighting the different biochemical properties of specific fibre type and their selective involvement in certain disease processes. Second, they may show an absences of a particular enzyme. Third, an excess of a particular substrate can be demonstrated. Fourth, they may show structural changes in the muscle which would not be apparent with routine histological stains, such as the enzyme-deficient cores in central core disease "mouth-eaten" fibers, and abnormalities in the distribution of mitochondria. In some neuromuscular disorders there could be only non-specific myopathological features. However, a number of proteins, including sarcolemmal, sarcomeric, and nuclear proteins as well as enzymes with defects responsible for neuromuscular disorders, have been identified during the past two decades, allowing a more specific and firm diagnosis of muscle diseases. Identification of protein defects relies predominantly on immunohistochemical preparations and on Western blot analysis. While immunohistochemistry is very useful in identifying abnormal expression of primary protein abnormalities in recessive conditions, it is less helpful in detecting primary defects in dominantly inherited disorders. Abnormal immunohistochemical expression patterns can be confirmed by Western blot analysis which may also be informative in dominant disorders. Besides identification of specific protein defects, immunohistochemistry is also helpful in the differentiation of inflammatory myopathies by subtyping cellular infiltrates and demonstrating up-regulation of subtle immunological parameters. This review will summarize and describe the impact that histochemistry and immunohistochemistry has had and the possibilities it has opened up in the diagnosis of neuromuscular disorders in human as well as in veterinary myology

Histochemical and immunohistological approach to comparative neuromuscular diseases.

The broad category of neuromuscular diseases covers conditions that involve the weakness or wasting of the body muscles. These problems may occur in the spinal cord, the peripheral nerves or the muscle fibers. Some may be hereditary, while others are acquired. Commonly recognized conditions fall into the categories of myopathies, which are diseases of the muscle like muscular dystrophy, disorders of the junction where the nerve impulses are transmitted to the muscle like myasthenia gravis, and neuropathies, which are diseases of the peripheral nervous system. The diagnosis of most neuromuscular diseases rest on careful clinical evaluation of the patient, electromyography, the muscle biopsy, and in some instances, molecular genetic studies. Muscle biopsy, associated to histochemical and immunohistological techniques, plays a key role in diagnosis of many neuromuscular disorders. A number of morphological abnormalities of muscle can be recognized on histological stains such as haematoxylin and eosin and Engel trichrome. Histochemical techniques are essential for the study of muscle biopsies for four main reasons. First, they demonstrate the non-uniform nature of the muscle highlighting the different biochemical properties of specific fibre type and their selective involvement in certain disease processes. Second, they may show an absences of a particular enzyme. Third, an excess of a particular substrate can be demonstrated. Fourth, they may show structural changes in the muscle which would not be apparent with routine histological stains, such as the enzyme-deficient cores in central core disease "mouth-eaten" fibers, and abnormalities in the distribution of mitochondria. In some neuromuscular disorders there could be only non-specific myopathological features. However, a number of proteins, including sarcolemmal, sarcomeric, and nuclear proteins as well as enzymes with defects responsible for neuromuscular disorders, have been identified during the past two decades, allowing a more specific and firm diagnosis of muscle diseases. Identification of protein defects relies predominantly on immunohistochemical preparations and on Western blot analysis. While immunohistochemistry is very useful in identifying abnormal expression of primary protein abnormalities in recessive conditions, it is less helpful in detecting primary defects in dominantly inherited disorders. Abnormal immunohistochemical expression patterns can be confirmed by Western blot analysis which may also be informative in dominant disorders. Besides identification of specific protein defects, immunohistochemistry is also helpful in the differentiation of inflammatory myopathies by subtyping cellular infiltrates and demonstrating up-regulation of subtle immunological parameters. This review will summarize and describe the impact that histochemistry and immunohistochemistry has had and the possibilities it has opened up in the diagnosis of neuromuscular disorders in human as well as in veterinary myology

Angiostrongylus vasorum: Epidemiological, clinical and histopathological insights

Background: Canine angiostrongylosis is a nematode infection in domestic dogs and wild carnivores. The present report focuses on epidemiological, clinical and histopathological findings in a case of fatal disseminated angiostrongylosis in a dog living in southern Italy and provides data on the extent of the spread of Angiostrongylus vasorum in the same area.Case presentation: A 4-year-old female English Setter from the Campania region of southern Italy was referred with a 2-week history of cough and severe respiratory distress that did not respond to antimicrobial therapy. Based on clinical, radiological, echographical and cytological findings (including the presence of larvae), a suspect diagnosis of lungworm infection was performed. After few days the dog died due to progressive clinical aggravation. Complete postmortem examination was conducted within 24 hours from death and samples from lungs, heart, liver, kidney, spleen, stomach and small intestine were fixed in 10% buffered formalin. Grossly, several hemorrhagic foci were observed mostly in the lungs, liver, kidney. Microscopically, the lungs contained numerous, multifocal to coalescing granulomas composed of epitheliod macrophages, multinucleated giant cells and some neutrophils, frequently associated with parasite eggs and larvae. The lungs contained many firm nodules, many adult nematodes approximately 1.5 to 2 cm in length were observed in cut sections and identified as A. vasorum. A subsequent parasitological survey performed with FLOTAC on stray dogs living in the same area showed the presence of A. vasorum larvae in 17 of 1639 stray dogs examined (1.04%).Conclusion: This survey provides new data on distribution of A. vasorum and underlines that canine angiostrongylosis should be considered as differential diagnosis in dogs

Reproducibility and Feasibility of Classification and National Guidelines for Histological Diagnosis of Canine Mammary Gland Tumours: A Multi-Institutional Ring Study

Histological diagnosis of Canine Mammary Tumours (CMTs) provides the basis for proper treatment and follow-up. Nowadays, its accuracy is poorly understood and variable interpretation of histological criteria leads to a lack of standardisation and impossibility to compare studies. This study aimed to quantify the reproducibility of histological diagnosis and grading in CMTs. A blinded ring test on 36 CMTs was performed by 15 veterinary pathologists with different levels of education, after discussion of critical points on the Davis-Thompson Foundation Classification and providing consensus guidelines. Kappa statistics were used to compare the interobserver variability. The overall concordance rate of diagnostic interpretations of WP on identification of hyperplasia-dysplasia/benign/malignant lesions showed a substantial agreement (average k ranging from 0.66 to 0.82, with a k-combined of 0.76). Instead, outcomes on ICD-O-3.2 morphological code /diagnosis of histotype had only a moderate agreement (average k ranging from 0.44 and 0.64, with a k-combined of 0.54). The results demonstrated that standardised classification and consensus guidelines can produce moderate to substantial agreement; however, further efforts are needed to increase this agreement in distinguishing benign versus malignant lesions and in histological grading. View Full-Tex

Ccdc6 knock-in mice develop thyroid hyperplasia associated to an enhanced CREB1 activity

CCDC6 was originally identified upon rearrangement with RET in human thyroid papillary carcinomas generating the RET/PTC1 oncogene. We have previously reported that CCDC6 interacts with CREB1 and represses its transcriptional activity. Since the function of at least one allele of CCDC6 is lost following RET/PTC1 rearrangements, we aimed at the generation of mice, carrying a CCDC6 mutant gene. Previous studies suggested that the coiled-coil domain of CCDC6, mainly encoded by human exon 2, is required for the protein function. Therefore, we engineered a murine Ccdc6 construct, carrying a deletion of the exon 2, that was able to exert only a mild repression on CREB1 transcriptional activity, with respect to the wild type Ccdc6. Subsequently, we generated Ccdc6-ex2 knock-in mice. These mice developed thyroid hyperplasia associated with an enhanced CREB1 activity and an increased expression of the CREB-1 regulated genes. These results strongly support a CCDC6 promoting role, ascribed to its functional impairment, in the development of thyroid papillary carcinomas harboring the RET/PTC1 oncogene

Pneumoconiosi nel cane: osservazioni al microscopio ottico, elettronico a trasmissione e a scansione e micro-analisi a raggi x

La fibrosi o sclerosi polmonare consegue a: 1.cronicizzazione di lesioni infiammatorie diffuse, o degenerative dei tessuti pleuropolmonari; 2.a proliferazione del connettivo peribroncovascolare per insulti ripetuti, cronici, agenti primitivamente sulle vie bronchiali o sul circolo polmonare; 3.a flogosi polmonari interstiziali granulomatose diffuse a reticoendoteliti e a collagenopatie 4.a proliferazioni elettive ed apparentemente primitive del mesenchima polmonare. Più frequentemente la fibrosi polmonare rappresenta l’esito di processi infiammatori polmonari, bronchiali o pleurici aspecifici - broncopolmoniti batteriche e virali, bronchiti acute e croniche, e specifici come la tubercolosi che è la causa più nota di processi fibrotici riparativi ed evolutivi. Anche la prolungata inalazione di alcune polveri minerali o di fumi, vapori e polveri nocive di origine industriale causa danno polmonare caratterizzato da fibrosi. Alcune affezioni cardio-vascolari (stenosi mitralica, insufficienza ventricolare sinistra, embolie polmonari) sono causa di fibrosi polmonari.Gli aspetti e le modificazioni strutturali osservati sono risultati particolarmente significativi essendo chiaramente connessi alla presenza di sostanze estranee e testimoniando pertanto una precisa risposta dei tessuti polmonari e linfonodali a stimoli derivati dalla noxa. L’aspetto più interessante delle nostre osservazioni è rappresentato dalla fibrosi, peribronchiale, perivascolare, alveolo-capillare e pleurica. Nel nostro studio, la stressa associazione tra proliferazione di tessuto connettivo e macrofagi attivati per la presenza del materiale particolato estraneo, conferma ancora una volta, sia il ruolo centrale svolto dal macrofago nella modulazione del processo fibrogenetico ed in particolare nelle fibrosi conseguenti a polveri sia l’importanza delle polveri aereodisperse nel determinismo di pneumopatie croniche. Il nostro studio ci permette di concludere che gli animali domestici rappresentano un valido modello per lo studio delle patologie ambientali e che il cane in particolare rappresenta un modello “privilegiato” per il fatto che questo vivendo strettamente a contatto con l’uomo, ne condivide ambiente e stile di vita e può essere quindi considerato, secondo la diversa tipologia di studio, un plausibile modello, indicatore o sentinella in grado di offrire risultati degni di considerazione scientifica