Dual-photon bone densitometry in dialyzed patients

In non-invasive diagnosis of renal osteodystrophy the levels of bone minerals and the extent of bone turnover are evaluated. The contents of bone minerals are assessed quantitatively by different modalities of bone densitometry, among which the most accurate one is double-energy bone densitometry. So far no standard examination method was defined nor the most suitable portion of the skeleton for densitometric examination. In order to find such an area and also to assess the prevalence of bone demineralization, its severity and regional differences the authors made a cross-sectional study of bone density in dialyzed patients. The group comprised 45 patients, 24 men and 21 women subjected to regular dialyzation treatment for 20-24 months. In a lambda whole body bone densitometry was performed with evaluation of regional densities of the trunk, upper and lower extremities. At the same time the state of bone turnover was assessed arbitrarily using values of serum concentrations of intact parathormone; parathormone concentrations below 50 pg/ml were considered low, above 200 pg/ml high and concentrations within the mentioned range as the normal bone turnover. In the group of patients 62% had a high, 22% a normal and 16% a low bone turnover. The study provided evidence of a significant reduction of bone density (Z score <-1) in 58% of patients. In 92% of patients demineralization affected most and first the extremities. In 69% it affected the lower extremities and in 23% the upper ones. 8% of the patients had the most severe affections in the area of the trunk. This order of affliction was not influenced by bone turnover, sex and in women by age. The diaphysis of long bones seems to be a representative examination area of the skeleton for densitometric measurements in patients with regular dialyzation treatment.     

Chromosome damage induced by benzene after the use of conventional and FISH chromosome painting

The cytogenetic effects of in vitro exposure to benzene were investigated in cultured bovine peripheral lymphocytes. Stable and unstable chromosome aberrations (CA) and sister chromatid exchanges (SCE) were examined. Cultures of lymphocytes from two healthy donors were treated with benzene at concentrations of 5, 10, 50, 100, 500 and 1000 micromol.l-1 for the last 24 hours and for 2 hours of cultivation, both without and with metabolic activation (S9). In the CA assays with conventional Giemsa staining for 24 hours without metabolic activation, no dose-dependence in the induced chromosome aberration was achieved. A significant elevation in the induction of CA was found only after the application of benzene at a dose of 100 micromol.l-1 (p<0.01). Similar results were observed using fluorescence in situ hybridization (FISH) method for the detection both of non-stable and persistent chromatid-type aberrations and in the SCE assay for 24 hours without S9. All the lower and higher concentrations tested have no positive influence on CA and SCE induction. In experiments with S9 a significant increase in CAs, and a dose-dependence was achieved after exposure to benzene for 2 hours at concentrations ranging from 50 to 500 micromol.l-1 (p<0.05 and p<0.01, respectively).     

Cytoimunofluorometry and its use in the detection of blood platelet activation

Blood platelet activation is a complex process involved in the physiological hemostasis and also in a number of disorders. Platelets change their morphology, modify their surfaces glycoprotein receptors with adhesive functions. Procoagulant microparticles are shedding and the aggregates of platelets with leucocytes are appearing. The activated platelet can be detected by flow cytometry after imunofluorescent staining.     

Hypernatraemia, increased protein intake and progression of renal insufficiency in a patient with polycystic renal degeneration

The authors submit the case of a patient with polycystic degeneration of the kidneys where after haemorrhage from the anterior cerebral artery hypernatraemia developed and concurrently significant acceleration in the progression of renal insufficiency to failure developed. Hypernatraemia was caused by non-natrium osmotic diuresis conditioned by increased urea excretion. In chronological association with increased dietary protein intake renal insufficiency was hastened.     

Echocardiography and sonography of the carotid arteries in diabetics with cerebrovascular stroke

The incidence of cerebrovascular attacks (CVA) in diabetics is 2-3 times higher as compared with the non-diabetic population. The objective of the present work was to evaluate etiological factors by means of echocardiography and sonography of the carotid arteries. The authors evaluated retrospectively findings of these examinations in 253 patients with CVA in a group of diabetic and non-diabetic patients as well as in a group of patients with atrial fibrillations or sinus rhythm. In patients with a sinus rhythm the presence of diabetes was associated with a more frequent finding of atherosclerotic changes, significant stenoses of the carotid vessels (2% as compared with 8%, p < 0.05) as well as thickness of the intima in the carotid bulbus (0.78 as compared with 0.96 mm, p < 0.05). Conversely when evaluating signs of thromboembolic risk, i.e. the size of the left ventricle (42 vs. 40 mm, n.s.) and ejection fraction of the left ventricle (55% vs. 50%, n.s.) no statistical significance in the difference of parameters was found. In the sub-group of patients with atrial fibrillation, who accounted for 28% of the group, the authors did not find when comparing diabetic and non-diabetic patients, any difference as regards the presence of significant stenoses in the carotid arteries nor in the thickness of the intima. There was no statistically significant difference in the size of the left atrium and left ventricular function. The findings suggest the possibility that the increased risk of ischaemic CVA in diabetic patients is caused by the atherosclerotic process in the carotid vessels and not a higher risk of embolism of cardiac origin.     

Pregnancy in patients with hereditary spherocytosis

The influence of pregnancy on the course of hereditary spherocytosis was investigated in 21 women during their 44 pregnancies. Fourteen pregnancies were followed up directly, 30 were evaluated from anamnestic data. In the majority of investigated women with hereditary spherocytosis pregnancy caused no problems. When complications developed, they were not serious as a rule. Only about one third of pregnancies in non-splenectomized women developed anaemia or anaemia deteriorated. In the latter enhanced haemolysis participated. In splenectomized patients the incidence of complaints was minimal.     

Distribution of the extracellular matrix glycoproteins in ependymomas--an immunohistochemical study with follow-up analysis

The extracellular matrix (ECM) plays a critical role in influencing the biological behavior of brain tumors and the diagnostic detection of ECM components in ependymomas might be of prognostic value. In the present study we evaluated immunohistochemically the expression of a spectrum of ECM glycoproteins (tenascin, vitronectin, fibronectin, laminin, collagen types II, IV and VI) in a series of 36 pediatric intracranial ependymomas. The distribution of the ECM glycoproteins was evaluated both within the tumor tissue and at the tumor invasion front, and the prognostic value of the results was tested in a survival analysis. The expression of most of the ECM glycoproteins was associated only with blood vessels. Tenascin and vitronectin were found in a more diffuse pattern around the tumor cells and at the tumor invasion fronts of several cases. The progression-free survival was significantly decreased for patients with tenascin positive tumors (in any of the studied compartments) and for the tumors with vitronectin accumulation at their invasion fronts. In one ependymoma containing foci of cartilage with metaplastic ossification we demonstrated that collagen types II and VI and tenascin were present in ECM of both the cartilage and the ependymoma, and were accompanied by areas of necrosis and dystrophic calcifications. We suggest, that the rare simultaneous production of the specific ECM components might lead to the formation of chondroid areas in ependymomas. An abundant production of some ECM glycoproteins (tenascin and vitronectin) is present in a proportion of ependymomas and its immunohistochemical detection is of prognostic relevance.     

Cytoprotective effects of amifostine in the treatment of tumors

An efficient therapy of patients with tumorous diseases should include maximum killing of malignant cells with minimal damage to cells in healthy tissues. Radiotherapy and chemotherapy are frequently associated with a series of undesirable effects. Side effects related to the therapy may unfavorably influence quality of life for a short or long period of time, may cause the need to decrease the dosage or shorten the overall period of treatment or survival of the patient. Therefore, particular attention has recently been paid to compounds, which mitigate or eliminate the undesirable effects of the therapy. A way to decrease toxicity is the administration of radioprotective or chemoprotective compounds. The cytoprotection of healthy tissues by compounds from the aminothiol group is one of the most promising directions of research and clinical practice. Amifostin protects healthy tissue from damage induced by radio- or chemotherapy. In comparison with patients treated by radiotherapy only, radiotherapy supplemented with amifostin proved to cause significantly less acute and late untoward effects of therapy. The paper describes the possibilities of using radioprotective drugs, especially amifostin, in the therapy of tumors with particular emphasis to the needs of physicians dealing with the problems of internal medicine.