Morphometric and ultrastructural studies of the sciatic nerve regeneration in rats intoxicated with ethanol

The aim of the study was to examine the process of sciatic nerve regeneration and changes in the dorsal root ganglia (from which sensory fibres of the sciatic nerve extend) in animals intoxicated with ethanol. The experiment used 20 rats, divided into two groups: control and treated. The treated animals were intragastrically given 2g/kg b.w. of ethanol in 25% aqueous solution. In both groups the right sciatic nerve was transected and then sutured. After 5 months the animals were anaesthetized. The left and the right spinal dorsal ganglia-L5 and sections from the non-operated and operated sciatic nerves were collected for analysis. Ultrastructural examinations and morphometric measurements were conducted. It was found that ethanol administrated to rats inhibited regeneration of the transected and then sutured sciatic nerve, impairing the growth of axons in the transected nerve and destroying the regenerating sensory ganglion cells. The mechanism of the changes described may be associated with axonal transport disorders or with the suppressed production of biologically active substances, which affect nerve regeneration.

[Proliferative activity of glial neoplasms of the brain]

The aim of the study including 89 brain gliomas was to determine their proliferative activity assayed with immunohistochemical methods (PCNA and Ki-67) and with the method of AgNORs, as well as to evaluate the correlation between the proliferative activity and features of histological malignancy. The study reveals that the estimation of PCNA, Ki-67 and AgNORs are effective methods for the determination of the proliferative activity of brain gliomas. Statistically significant differences were noted in the proliferative PCNA, Ki-67 and AgNORs between groups of gliomas with lower and higher malignancy, which indicated a distinct correlation between histological malignancy of the tumours and their proliferative activity. High values of PCNA and Ki-67 (> 40%) and AgNORs (> 15) were found to considerably deteriorate prognosis in brain gliomas.

Ultrastructure of bone marrow megakaryocytes in experimental haemorrhagic shock in rats. I. Correlation between ultrastructure of MK nuclei and DNA ploidy

The correlation was described between the ultrastructural picture and DNA mass content of MK nuclei in experimental haemorrhagic shock in rats. Significant disproportions were revealed between the morphological pictures and the ploidy of MK nuclei in the successive phases of the shock. Abnormalities of the maturation of marrow MK nuclei were found in the first hours of the shock, being most pronounced in the 24th hour.

Ultrastructural studies of the effect of pentoxyfylline on the hepatic cell of the rat with simultaneous administration of cyclophosphamide

Ultrastructural examinations carried out on liver specimens collected from Wistar rats revealed that single administration of cyclophosphamide in a dose of 150 mg/kg body weight produced changes in the cytoplasmic structures, particularly in the smooth endoplasmic reticulum and mitochondria. The changes were reversible and subsided 14 days following cyclophosphamide administration. Administration of pentoxyfylline to rats in a dose of 30 mg/kg b.w./day for 10 days induced structural alterations in the intracytoplasmic structures of hepatocytes, similar to those caused by cyclophosphamide, although more intensified in the vicinity of the vascular pole. The pentoxyfylline-induced changes in hepatocytes retreated already 4 days after its withdrawal and can be considered adaptative. Simultaneous administration of both drugs to rats resulted in enhanced metabolic disturbances in hepatocytes and dissociation of adaptative mechanisms manifesting themselves in irreversible morphological changes in the intracytoplasmic structures and in the occurrence of collagen in the intercellular spaces.

Morphometric and ultrastructural studies of the spinal sensory ganglia in the course of sciatic nerve regeneration in rats intoxicated with ethanol

The aim of the study was to examine morphological changes in the spinal dorsal ganglia (from which sensory fibres of the sciatic nerve extend) in animals intoxicated with ethanol, in which the sciatic nerve was transected and then sutured. By means of morphometric methods using a computer system of picture analysis and in ultrastructural examinations it was found that ethanol administered to rats to drink for 3 months caused only slight morphological alterations in the sensory nerve cells of the spinal vertebral ganglia on the non-operated side. However, ethanol or its metabolites destroyed the regenerating sensory nerve cells of the spinal vertebral ganglia of the transected and then sutured sciatic nerve.

Ultrastructure of bone marrow megakaryocytes in experimental haemorrhagic shock in rats. II. Correlation between ultrastructure of MK cytoplasm and thrombopoiesis

Ultrastructural evaluation was performed of the MK cytoplasm in the successive phases of experimental haemorrhagic shock in rats. Qualitative abnormalities were revealed in the intracytoplasmic structures of MK. Platelets in the circulating blood were evaluated. A correlation was found between the changes in the intracytoplasmic organelles and the number and biological activity of blood cells. The results obtained indicate significant disturbances in the functioning of the thrombopoietic system in experimental haemorrhagic shock, which are caused by alterations within the intracytoplasmic structures of MK and lead to platelet production from morphologically differentiated but functionally immature MK.

The ethanol effect on lung metastases development in experimental Morris 5123 hepatoma

The experiment was carried out on 45 male Wistar rats which were divided into 3 groups: group I-15 rats which were given water to drink during the experiment, group II-15 rats obtaining 10% ethanol solution during the experiment and group III-15 rats obtaining 20% ethanol solution during the experiment. All animals were injected 0.3 ml suspension of hepatoma Morris 5123 cells directly to the liver on the 14th day of the experiment. After the 9 weeks of the experiment the animals from all groups were narcotized, decapitated and the lungs were taken into the morphometric, histological and ultrastructural examinations. They showed that ethanol has a stimulating effect on formation and development of hepatoma Morris 5123 in rat lungs. The increase of number and extensiveness of metastases as well as the increase of mean metastases focuses volume, and the increase of lung weight in animals which obtained ethanol are the exponent of the influence. On the basis of ultrastructural examinations, it can be noted that promoting activity of ethanol can be connected: a) with the increase of neoplastic cells activity, b) with changes appearing in pulmonic epithelium and endothelium of vessel enabling neoplastic cells to adhere to basal membrane as well as their crossing the vessel wall.

[Intracranial chordomas; histochemical and immunohistochemical examinations]

Chordoma is one of rare intracranial neoplasms (0.2-0.5%). Apart from classic chordoma in 1973 r. Heffelfinger and al. separated chondroid chordoma which showed better prognosis. We studied 4 classic and 3 chondroid intracranial chordomas. All tumours contained chondroitine sulfate and keratan sulfate and showed positive immunohistochemical reactions to cytokeratin, S-100 protein and vimentin, supporting the concept of common origin of both types of chordomas. Immunohistochemical studies of PCNA and Ki-67 antigen and staining AgNOR's did not show significant differences in the proliferative activity between both types chordomas what attests to biological malignancy.

[Study of the effect of biogonadyl on the regeneration of the rat's sciatic nerve]

Using electroneurographic and morphological methods the effect of Biogonadyl on the regeneration of sectioned and the sutured sciatic nerves was evaluated. The analysis of conduction parameters in the sciatic nerves during the 6-week experiment, although the results obtained were not statistically significant, suggests a beneficial effect of Biogonadyl upon regeneration processes in the nerves. Morphological and morphometric studies have demonstrated that Biogonadyl statistically significantly accelerated axon growth in the distal part of sciatic nerves. It did not, however, influence the processes of their maturation.

The effect of activated alveolar macrophages on experimental lung emphysema development. I. Protease and antiprotease activities in the culture medium of alveolar macrophages

Aim of the present study was to evaluate cathepsin D, base protease, antiplasmin, antitrypsin and antichymotrypsin activities and protein content in the 24h culture medium of the alveolar macrophages (AM) deriving from the rats treated BCG-vaccine and from rats with papain-induced emphysema. In the culture medium of cells isolated from the rats which were given BCG or papain and BCG+papain we observed an increase of base protease activity and a decrease of cathepsin D activity comparing with control group. Increased antitrypsin activity in BCG and BCG+papain-treated rats and decreased antitrypsin activity in papain-treated rats were observed. There were not significant differences in antiplasmin and antichymotrypsin activities between examined groups. The obtained results indicate that activated pulmonary macrophages are one of the sources of the protease-antiprotease intraalveolar imbalance. However, increased production of proteolytic enzymes may not be the only factor responsible for the progression of lung emphysema in BCG-treated rats.

[Study of platelet count and phagocytic activity in experimental hemorrhagic shock. II. Evaluation of phagocytic activity of platelets]

The platelets phagocytic activity has been measured in rats during experimental haemorrhagic shock determining the per cent of phagocytic platelets and phagocytic index. The authors have the decrease of phagocytic activity of platelets during haemorrhagic shock. Disturbances of phagocytic activity of platelets have been accompanied by changes of their shape and formation platelet aggregates.

Widespread myocardial and pulmonary bone marrow embolism following cardiac massage

Widespread fatal massive bone marrow embolism of the coronary and the pulmonary arteries are described in a 71-year-old man with a respiratory disease. Cardiac massage was carried out during the cardiac arrest. In autopsy findings there were no fractures of the ribs or the sternum. The authors suggested that the cardiac massage was the most important predisposing factor for the bone marrow embolism.