Kazimierz Ostrowski

Expression of genes for bone morphogenetic proteins BMP-2, BMP-4 and BMP-6 in various parts of the human skeleton

BackgroundDifferences in duration of bone healing in various parts of the human skeleton are common experience for orthopaedic surgeons. The reason for these differences is not obvious and not clear.MethodsIn this paper we decided to measure by the use of real-time RT-PCR technique the level of expression of genes for some isoforms of bone morphogenetic proteins (BMPs), whose role is proven in bone formation, bone induction and bone turnover. Seven bone samples recovered from various parts of skeletons from six cadavers of young healthy men who died in traffic accidents were collected. Activity of genes for BMP-2, -4 and -6 was measured by the use of fluorescent SYBR Green I.ResultsIt was found that expression of m-RNA for BMP-2 and BMP-4 is higher in trabecular bone in epiphyses of long bones, cranial flat bones and corpus mandibulae then in the compact bone of diaphyses of long bones. In all samples examined the expression of m-RNA for BMP-4 was higher than for BMP-2.ConclusionIt was shown that m-RNA for BMP-6 is not expressed in the collected samples at all. It is postulated that differences in the level of activation of genes for BMPs is one of the important factors which determine the differences in duration of bone healing of various parts of the human skeleton.

Fractal and Fourier analysis of the hepatic sinusoidal network in normal and cirrhotic rat liver

The organization of the hepatic microvascular network has been widely studied in recent years, especially with regard to cirrhosis. This research has enabled us to recognize the distinctive vascular patterns in the cirrhotic liver, compared with the normal liver, which may explain the cause of liver dysfunction and failure. The aim of this study was to compare normal and cirrhotic rat livers by means of a quantitative mathematical approach based on fractal and Fourier analyses performed on photomicrographs and therefore on discriminant analysis. Vascular corrosion casts of livers belonging to the following three experimental groups were studied by scanning electron microscopy: normal rats, CCl4‐induced cirrhotic rats and cirrhotic rats after ligation of the bile duct. Photomicrographs were taken at a standard magnification; these images were used for the mathematical analysis. Our experimental design found that use of these different analyses reaches an efficiency of over 94%. Our analyses demonstrated a higher complexity of the normal hepatic sinusoidal network in comparison with the cirrhotic network. In particular, the morphological changes were more marked in the animals with bile duct‐ligation cirrhosis compared with animals with CCl4‐induced cirrhosis. The present findings based on fractal and Fourier analysis could increase our understanding of the pathophysiological alterations of the liver, and may have a diagnostic value in future clinical research.

BMP-4 and BMP-6 involvement in the osteogenic properties of the HeLa cell line.

The heterotopically induced ossicles are used in our research on bone tissue. The ossicles are formed in the thigh muscle of BALB/c mice under the influence of injected suspension of 3 × 106 HeLa cells. We postulate that the mechanism of bone induction is based on the secretion of bone morphogenetic proteins BMP-4 and BMP-6 by the grafted HeLa cells. This was proved by the use of specific immunohistochemical reaction and Western blots of conditioned culture medium. It seems that HeLa cells secrete BMPs continuously into the culture medium, even without contact with the mice muscle tissue, were induction of bone tissue is observed.

Symmetry of Retinal Vessel Arborisation in Normal and Amblyopic Eyes

Purpose: Arborisation of retinal vessels might be influenced by the physiological activity of the retina. It seems that the pattern of retinal vessels is an obvious object for fractal analysis. The fractal dimension of normal retinas was therefore used by us as a control value for comparison with the values collected from patients with amblyopia in one eye connected with strabismus and normal vision in the other. Methods: The ‘box-counting method’ was used for calculation of self-similarity dimension in 54 control patients, i.e. comparing 54 left retinas with 54 right ones. Statistical analysis was performed for these groups. This value was therefore used as a control for comparison with the values of fractal dimensions measured in patients with amblyopia connected with strabismus in one eye and normal vision in the other. The retinas of 30 patients with strabismus in one eye and of 1 patient with strabismus in both eyes were analysed. Results: The measurements performed on digitised photos of the retinas of these patients proved statistically significant differences between the control group and the fractal dimensions for the arborisation of retinal vessels in the eyes of patients with normal vision as well as differences in comparison with the retinas of functionally disabled eyes with defective vision connected with strabismus. Conclusion: The final conclusion is not obvious. It seems that normal vision has a statistically confirmed influence on the development of retinal vessels. Defective vision connected with strabismus is disturbing the process of arborisation of the retinal vessels. The retinal vessels of the patient eyes with normal vision differ from the normal pattern as defined by fractal dimensions of control eyes.

Influence of osteoprotegerin (OPG) on resorption of heterotopically induced ossicle.

In this paper, the effect of osteoprotegerin (OPG) on slowing down the resorption process of heterotopically induced bone tissue is described. The induced ossicle is resorbed ex inactivitate. This system mimics osteoporosis in immobilised skeletal bones. Bone induction was achieved in BALB/c mice after the injection of the suspension of 3 × 106 HeLa cells into thigh muscle of animals immuno-suppressed by a single dose of hydrocortisone. To slow down the process of resorption we applied OPG and measured quantitatively the effect by weighing the mass of mineral deposited in the induced ossicle after hydrolysis of soft tissues surrounding the induced ossicles. As the effect of application of OPG more than 340–540% of bone mineral is found in the induced ossicles following nine applications of 0.05 mg OPG per mouse, every second day — in comparison to the control animals.

Cross-Linked C-Terminal Telopeptide of Type I Collagen in Serum before and after Treatment with Alfacalcidol and Calcium Carbonate in Early and Moderate Chronic Renal Failure

The diagnosis of renal osteodystrophy (RO) in chronic renal failure (CRF) in everyday practice depends on noninvasive methods. Still there is no widely accepted bone resorption marker in RO. The aim of the study was to evaluate the correlation of serum cross-linked C-terminal telopeptide of type I collagen (s-CTx) as the resorption marker with clinical and biochemical data and to evaluate s-CTx level changes after treatment with low dose of alfacalcidol and calcium carbonate. Sixty patients (36 men and 24 women) with creatinine serum level 3.0 ± 1.5 mg% were examined. The result of s-CTx was normal in 27 patients and increased in 33. There was a significant positive correlation of s-CTx and serum creatinine (p < 0.001), alkaline phosphatase activity (p < 0.05) and duration of CRF (p < 0.05) in men and serum creatinine (p < 0.001) and phosphorus (p < 0.05) in postmenopausal women. Patients with increased s-CTx had significantly higher serum creatinine (p < 0.001), phosphorus (p < 0.01), alkaline phosphatase activity (p < 0.001) and longer duration of CRF (p < 0.001) than patients with normal s-CTx. Next, 25 patients were treated for 6 months with alfacalcidol in dose of 0.25 µg every other day and calcium carbonate in dose of 3.0 µg per day and 25 patients with calcium carbonate only. There was a statistically significant decrease of s-CTx in both groups of patients (p < 0.01). We conclude, that in patients with CRF, s-CTx can be taken as the marker of bone resorption changes after treatment of RO but the value of s-CTx as a diagnostic marker in these patients ought to be evaluated in comparison with histomorphometry.