Ligamentum flavum analysis in patients with lumbar discus hernia and lumbar spinal stenosis

The normal ligamentum flavum (LF) is a well-defined elastic structure with specific innervation. Several studies investigated LF in patients with lumbar spinal stenosis (LSS) and used lumbar discus hernia (LDH) patients as control group, only on the presumed thesis that LF in this patients have normal morphology. In patients with LSS thickening of the LF is the main cause of stenosis, which is most often presented with neurogenic claudication, whose pathophysiological mechanism is not completely understood. We conducted observational cohort study of 60 operated patients divided into two groups. The first group of 30 patients underwent micro-discectomy (LSH group), and second group with 30 patients underwent decompression, after which analysis of harvested LF was performed. Patients from the LDH group and LSS group differed significantly in the frequencies of chief complaints, duration of symptoms, physical examination, and specific morphological/radiological parameters. The LF analysis showed that the groups differed significantly in the amount of collagen and elastic fibers, as well as in the histological appearance/architectonics of elastic fibers. Also, groups differ in the presence of LF nerve fibers. Our findings speak in favor of the recently postulated inflammatory theory in the origin of spinal neurogenic claudication's.

[Morphologic changes in cardiac muscle in white rats in various models of hypoxia]

The authors have explored the effect of intermittent hypoxia in the cell membrane and histochemical changes in the cardiac muscle cells of the white rat. Every day the animals were exposed to experimental conditions characteristic of 7.000 m of high above sea level (first experimental group) and every odd day (second experimental group). Animals of the experimental groups were sacrificed immediately (first subgroup), 24 hours later (second subgroup) and 7 days after the final exposition (third subgroup). The hypoxical stress elicited the vacuolation of the cardiac muscle fibres of the subendocardiac layer of miocard which persisted, and did not reduce its number, intensity and extensity in the first experimental group, although it reduced its intensity and vacuoles size in the second experimental group, while in fuxinorrhagia which has been presented focally the intensity has been reduced in all the three subgroups of the first experimental group of animals. In preparations of animals from the second group, sacrificed 24 hours after the experiment intensity and extensity fell to the half number of those animals, and completely disappeared in those sacrificed 7 days after the final exposure. Glycogen pools, as well as the activity of sucinat-dehydrogenase were preserved in both experimental groups. It could be concluded that apart from hypoxia model, oxygen deficit, too, elicites ischemical changes in the sense of vacuolation of muscle tissue which does not disappear or its disappearance has been much slower than in positive fuxinorrhagia.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of calcium on the action of Vipera ammodytes ammodytes snake venom on the myocardium

V. ammodytes ammodytes snake venom produced irreversible block of the isolated, artificially stimulated rat right ventricle or isolated rat heart. This was the result of degenerative changes of the myocardium caused by the direct effect of toxic components of the venom. An excess of Ca2+ could temporarily restart the contractions.