The value of the reprocessing method of paraffin-embedded biopsies for transmission electron microscopy.

Transmission electron microscopy (TEM) implies an elaborate preparation protocol that includes: fixation in glutaraldehyde followed by osmium tetraoxide postfixation, specimen dehydration, infiltration, resin embedding, ultrathin sectioning and staining with heavy metal salts. The aim of TEM is to examine the ultrastructure of specimens in ways that cannot be examined using other equipments or techniques. In some cases, when the requirement for TEM were made after tissue collection, useful information can be obtained from reprocessing the formalin-fixed, wax-embedded tissue used for light microscopy.

Experimental COPD induced by solid combustible burn smoke in rats: a study of the emphysematous changes of the pulmonary parenchyma.

According to the GOLD 2006 definition, COPD is a preventable and treatable pathological situation characterized by the partially reversible airflow limitation determined by a variable proportion mixture of small airways disease (obliterative bronchiolitis) and parenchyma destruction (emphysema). A major impediment in the study of the COPD is represented by the fact the fundamental morphological changes that determine the major pulmonary dysfunction take place in the small, peripheral, airways, at the bronchiolo-alveolar attachments. That is why the experimental model of COPD developed progressively to the transgenic mouse. There are many experimental studies on the animal models that have obtained emphysema rapidly through intratraheal instillation of elastasis or bronchitis/bronchiolitis through intratraheal instillation of particles. It is accepted that the unnatural character of aggression, that does not permit the natural evolution of the inflammatory phenomenon, limits these models and tissue remodeling that take place in COPD patients. It is well known that cigarette smoking is a major cause of COPD. There have been reported some cases of COPD in never smoking patients exposed to air pollutants. We aimed to create an experimental model of COPD in rat through exposure to smoke resulted from solid combustibles burn for the same period and in the same conditions of cigarette smoke exposure and to compare the pulmonary morphological changes. Thirty Wistar rats were divided into three groups (n = 10): (1) the control group (C), (2) the cigarette smoke group (CS), and (3) the solid combustible smoke group (SCS). Apart from the control group, these were treated with solid combustibles smoke (SCS group) or cigarette smoke (CS group) for six months. Morphological and morphometry studies have been assessed. We have established a rat COPD model based on natural cigarette smoke exposure versus solid combustible burn resulted smoke, usable for a further approach in human non-smoker COPD investigation. Out procedures resulted in clear pulmonary morphological lesions that are characteristic for COPD. The achieved data support the idea that solid combustible burn resulted smoke determines emphysematous parenchyma lesions that are similar, but with an attenuated morphological appearance when comparing to the cigarette smoke exposure.

Chronic obstructive pulmonary disease in a new concept.

Chronic Obstructive Pulmonary Disease (COPD) is a preventable and treatable disease with some significant extrapulmonary effects that may contribute to the severity in individual patients. Its pulmonary component is characterized by airflow limitation that is not fully reversible. The airflow limitation is usually progressive and associated with an abnormal inflammatory response of the lung to noxious particles or gases. Although COPD is a nonspecific term referring to a set of conditions that develops progressively because of a number of different disease processes, it most commonly refers to patients with chronic bronchitis and emphysema and to a subset of patients with asthma. Several different definitions were proposed for COPD in time. COPD is not asthma but can coexist with asthma, the other major airways obstructive disease caused by airway inflammation. Inflammation underlying in asthma has characteristic features, distinct of that from COPD. Longitudinal studies revealed the heterogeneous character of COPD. The pathological hallmarks of chronic obstructive pulmonary disease (COPD) are inflammation of the small airways (bronchiolitis) and destruction of lung parenchyma (emphysema). International guidelines stress the importance of accurately discriminating between asthma and chronic obstructive pulmonary disease. Although characteristic pathological features have been described for both conditions, their discriminatory power has never been systematically assessed. This might be rectified by improving pathological definitions.

Morphological changes positive correlates with oxidative stress in COPD. Preliminary data of an experimental rat model--study and literature review.

It is well known that nicotine that is a major toxic component of cigarette smoke induces oxidative stress which is responsible for the lung damages in COPD and cancer. There have been reported some cases of COPD in never smoking patients exposed to air pollutants. The aim of our study is to evaluate the morphological pulmonary changes in rats exposed to cigarette smoke respectively to solid combustible smoke and to establish the relationship between the exposure and the level of oxidative stress measured through serum (s) and pulmonary tissue (l) MDA in rats (TBARS method). Thirty Wistar rats were divided into three groups (n = 10): (1) the control group (C), (2) the cigarette smoke group (CS), and (3) the solid combustible smoke group (SC). Apart from the control group, these were treated with solid combustibles smoke or cigarette smoke for six months. We collected blood for serum determination of MDA and the lungs were removed for histopathological analysis and to determine the levels of malondialdehyde (MDA). The levels of serum and lung MDA were significantly higher in CS and SC groups compared with C group, but not significantly differences between CS and SC group were detected. These findings are positively correlated with histopathological changes (squamous metaplasia and clear cell hyperplasia in the bronchium epithelium, emphysema) found in pulmonary tissue. Preliminary data of our study confirms that not only the cigarette smoke but also the environmental pollutants are involved in the major pathways of COPD.

Neurofibroma, schwannoma or a hybrid tumor of the peripheral nerve sheath?

Classically, the different subtypes of the peripheral nerve sheets tumors display typical morphological features which differentiate them from the other nervous tumors. Either schwannoma or neurofibroma have characteristic histological and immunohistochemical features. We present a case of peripheral nerve sheets hybrid tumor which have had histological and immunohistochemical features of neurofibroma and schwannoma.

Histiocytic sarcoma associated with Hodgkin's disease.

Histiocytic sarcoma is a rare malignant neoplasm. It is well-known the association of Langerhans' cell histiocytosis with Hodgkin's disease but only few cases of histiocytic sarcoma associated with Hodgkin's disease was reported. We present the case of 20-years-old female patient with Hodgkin's disease with a sternal tumor mass which was diagnosed as histiocytic sarcoma. The diagnostic was established immunohistochemically, using a large battery of antibodies (S-100, CD 68, CD 34, CD 15, CD 30, Vim, NFAP) and by electron microscopy which revealed the lack of the Birbeck granules in the malignant proliferated histiocytes.