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The author presents a review on the most frequently encountered sources of malignant secondaries in bones, on their sites and their possible detection. Part of the review deals with the mechanism of deposition of metastatizing elements in bones and explains the basic sources of tumourous osteolysis. Finally the author mentions some recent trends as regards approaches to treatment of bone metastases.

The influence of growth hormone upon trabecular bone remodelation is not definitely clear. The authors of this study compared static and dynamic histomorphometric data of bone patterns of 28 numbered group of acromegalics and 35 numbered group of healthy individuals. They correlated also levels of growth hormone, thyroxine, prolactin and testosterone in men with histomorphometric parameters in acromegalic patients. The results showed statistically significant differences between normal and acromegalic trabecular bone, which has comparable trabecular volume, but significantly wider bone trabeculae and lower mean trabecular density. There were no correlations found between growth hormone levels and levels of thyroxine, prolactin, measured testosterone and histomorphometric parameters.

Changes in bone spongiosa, which follow after administration of growth hormone (GH) are described differently. Histomorphometrically processed value of bone trabecular volume is found higher or lower than normal. In this study, changes of rat bone spongiosa after administration of GH or bisphosphonate pamidronate were followed. The authors found statistically significant widening of histomorphometric parameter of trabecular thickness, but histomorphometrically assessed values of trabecular bone volume were not statistically different from normal rat bones. The structure of spongiosa is changed, the density of trabecular bone is diminished. The hypothesis of trabecular bone increase after GH administration together with resorption blocking agent (pamidronate) was not confirmed. GH causes widening of bone trabeculae. Pamidronate has no influence on bone histomorphometry in this case.

The influence of duration of growth hormone action (length of history of acromegaly) upon acromegalic trabecular bone histology was followed in 28 biopted active acromegalics. The histology of trabecular bone was standardized by histomorphometric parameters. No statistically significant relation between length of acromegalic history and any of measured histomorphometric parameters (trabecular volume, trabecular thickness, absolute osteoid volume and osteoid surface) was found. The reason of this finding is probably consequence of serum growth hormone level, which changes during period of history in each acromegalic patient. With aim to find out if growth hormone influences bone histomorphometry of acromegalics after causal treatment (removal of hypophyseal adenoma causing overproduction of growth hormone), the comparison of histomorphometry from bone bioptic patterns of six active acromegalics with their bone patterns average 9.3 years after hypophyseal operation was done. With the exception of one eugonadal woman, all acromegalics were hypogonadal in time of second biopsy. Nevertheless no statistically significant differences between histomorphometric data (trabecular volume, trabecular thickness, surface and absolute volume of osteoid) were found. With knowledge of fact that there is low number of rebiopted acromegalics, these results could support idea of protective action of growth hormone upon trabecular bone of acromegalics during nine years after treatment.

From 1988 to 1998 107 nephron sparing surgery have been done for localised renal cell tumor. The age was between 21 to 75. Nephron sparing surgery means removal of tumor consumed part of renal tissue with oncology clean border in healthy renal tissue. Elective indication for nephron sparing surgery is renal cell carcinoma on single kidney or on bilateral function disabled kidneys. In the last years indication for nephron sparing surgery have spread also to patients with both kidneys, who have single extrarenal growing renal cell carcinoma to the diameter 4.5 cm. In our group of follow up patients, within the interval 3 to 96 months from operation we have 96.26% survival without evidence of recurrent renal cell carcinoma.

The authors present evaluation of the application of BAS-0 bioactive glass-ceramics at the Orthopaedic Clinic in Hradec Králové in the period 1990-1997. Bioactive glass-ceramics was implanted in total in 106 patients of which in 38 patients during THR revision surgery and in 20 patients with bone infection. Of 48 patients with bioactive glass-ceramics used as a bony tissue replacement in filling the defects during operations of benign tumours or tumours of similar affections and in the surgical treatment of fractures of tibial plateau, 31 were followed up for the period ranging between 3 months to 6 years (average 3,2 years). In all patients followed the soft tissue surrounding the implanted glass-ceramics shows no reaction, radiographs showed bone trabeculae continuously pass over to the surface of the glass-ceramic particles and in no case we recorded periostal reaction or any other X-ray changes showing irritation, loosening or extrusion of this bone replacement. Key words: bioactive glass-ceramics, benign bone tumours and tumour-like affections, fractures of tibial plateau.

3T3 feeder layer technique provided support for clonal growth and serial propagation of two apparently single epithelial cells isolated from a peroperative biopsy of a primary ductal breast carcinoma. The total culture lifetime was estimated to be more than 30 doublings, 21 of which took place during the primary culture. The two cells were the only survivors of two-week exposure to stressing conditions that resembled the microenvironment in a tumour (low pH, depleted nutrition and accumulation of metabolic waste). The epithelial character of the cells was proved by positive immunostaining for keratins 7/17. The majority of growing cells did not express keratin 19. Only quiescent cells in some colonies, which appeared to reach a more advanced stage of differentiation, expressed keratin 19. These features correspond with the characteristics of mammary luminal cells which in vivo undergo differentiation from the stem K19- to secretory K19+ cells. The luminal cells are supposed to be the target of malignant transformation in the mammary gland. The described technique opens a regular way for the in vitro clonal growth of individual primary cells from breast tumours. Such an approach can improve our understanding of the biology of breast cancer cell populations and also simplify the predictive chemosensitivity assay on breast cancer cells from individual patients.

We report a light microscopic and ultrastructural appearance, and immunohistochemical profile of two benign tumours of soft tissue recently designated as desmoplastic fibroblastoma (collagenous fibroma). The tumours were located in the foot and well demarcated. Microscopically, they were composed of stellate--or spindle--shaped cells embedded in a hypovascular fibrous of fibromyxoid stroma. Immunohistochemical examination showed that tumours were diffusely positive for vimentin and focaly positive for smooth muscle actin and muscle specific actin. Ultrastructurally, the neoplastic cells had features of fibroblasts and myofibroblasts.

Objective: To introduce and test a standardized measurement protocol for DNA image cytometry into a newly developed LUCIA G system application program. Contribution to a discussion concerning the possibility of using the histology sections for DNA image cytometry., Study Design: Routine biopsy material from 18 urinary bladder cancer cases was analyzed (Grade 1: n = 6, Grade 2: n = 6, Grade 3: n = 6), both in histological and in cytoseparated preparations. More than one hundred diagnostic and more than 30 reference cells were measured. DNA features (mean DNA value, 2cDI, Böcking's grade of malignancy) and histogram types in Auer's classification (AI-IV) were compared., Results: Most carcinomas measured were aneuploid (two thirds G1, all G2, G3). The most common histogram type was A IV. Malignancy grade was mostly slightly higher in cytoseparated material, the shape of the histogram was analogous. Two carcinomas looking euploid in histology sections were proven aneuploid in cytoseparation., Conclusion: More convenient tissue section measurement provided useful DNA profile information in most cases. Those without proven aneuploidy should be additionally measured in cytoseparations. An experienced pathologist meeting strictly measurement protocol demands is an important part of the measurement system.

A number of skin models have been developed, but a simple method for rapidly producing large quantities of differentiated epidermis has been missing. We show the differentiated phenotype of human keratinocytes in organotypic culture arising in vitro by air-exposure of keratinocytes cultured with feeders on dried pig dermis. Keratinocytes were seeded at low density on the dermis covered with irradiated NIH-3T3 feeder cells and after reaching confluence lifted to the air-medium interface. A well differentiated epidermis with distinct basal, spinous, granular and stratum corneum layers was formed within 1 week. In this way, 100 cm2 of the differentiated recombined human/pig skin (D-RHPS) can be obtained from 106 secondary keratinocytes in 14 days. The entire keratinocyte life cycle takes place on the dermal substrate - from single cells to stratified epidermis. The differentiation was characterized using a panel of monoclonal antibodies. Similarly as in the normal skin, keratin 14 was expressed in all cell layers, keratin 10 in suprabasal layers, beta1-integrin and epitopes to antibody LH8 in the basal layer, involucrin and transglutaminase in the granular and horny layer of the epidermis. Keratins 16 and 7/17, which are absent in the normal epidermis, but present suprabasally in the psoriatic one, were expressed strongly in all suprabasal layers and in a subpopulation of basal cells. The keratinocytes can be combined with two other cell types cultured either on the dermal side of the dermis and/or on the bottom of the dish. It appears that this simple skin model can be used in studies of epithelial/mesenchymal interactions and interactions between epidermal cells and infectious agents. It may be particularly useful for the study of human papilloma viruses.

Five cases of pronounced histiocytic reaction in pelvic lymph nodes after hip replacement are demonstrated. Two patients subsequently underwent radical prostatectomies with bilateral lymph node dissections for adenocarcinoma. In three patients, the change was found during autopsy. The sinuses and interfollicular spaces were distended by numerous large macrophages that had bulky eosinophilic cytoplasm. The cells displayed immunoreactivity to KP1 antigen, alpha-1-antitrypsin and lysozyme, providing support for their histiocytic derivation. Polarization microscopy revealed birefringent needle-like particles in their cytoplasm. We think that the histologic appearance of lymph nodes represents a foreign body reaction to fragments of polyester or polyethylene derived from joint prostheses. It is necessary to be aware of this characteristic foreign body reaction in order to avoid confusion with other types of lymph node histiocytosis or with a metastatic tumor.

A primitive neuroectodermal tumour (PNET) of the minor pelvis is a rare malignant small-cell tumour developing from the neural groove. It metastatizes into the lungs, bones, liver and brain. Treatment involves radical surgical extirpation followed by chemotherapy and actinotherapy. The author presents the case-history of PNET of the pelvis minor in a 33-year-old woman.

In two patients with hip replacement, the pelvic lymph nodes were resected during prostatectomy for carcinoma. The striking histiocytosis was present in lymph nodes. The cytoplasm of histiocytes was bulky, granular, PAS positive, with KP1, lysozyme and alfa-1-antitrypsin positivity. In polarized light microscopy, the birefringent, needle-like particles corresponding to polyethylene or polyester respectively were seen. Those changes are characteristic for reactive lymphadenopathy in regional lymph nodes following joint endoprosthesis.

A case of a rare benign solitary pulmonary neoplasm of alveolar adenoma type in a 42-year-old man was presented. The tumor consisted of a glandular component which reacted with antibodies against cytokeratins CAM5,2, AE1-3 as well as against epithelial membrane antigen (EMA) in superficial parts of cytoplasmatic membrane, while actin and desmin were positive in the stromal component. Ultrastructurally, glandular component represented chiefly type II pneumocytes, while pneumocytes of type I occurred rarely. Stroma of the tumour consisted of myofibroblasts, fibrocytes, and collagen fibrils.

Chondroblastomas are unusual cartilage benign lesions of bone that have well-characterized histological features. We reviewed and immunohistochemically examined the paraffin block material of 20 cases, and in seven tumors of this collection we found distinct cytoplasmic muscle-specific actin positivity of some tumor chondroblasts and chondrocytes. Muscle-specific actin-positive cells had the histological and ultrastructural features typical of chondroblasts. Moreover, in their cytoplasm they contained bundles of microfilaments with focal densities, as is typical of myofilaments. We did not observe any basal lamina around these cells, which were surrounded by intercellular matrix of the cartilage tissue type. Therefore, we suppose that muscle-specific actin-positive cells occurring in some chondroblastomas do not represent an admixture of myofibroblasts but chondroblasts with actin expression. The unusual immunophenotype of some chondroblasts might be the result of aberrant actin expression or of the plasticity of their phenotype modulated by microenvironmental stimuli. It is a question of whether, analogously to the terminology of myofibroblasts, such cells could be designated as myochondroblasts.

Background: The highly swelling poly (glycerol monomethacrylate) gel (polyGLYMA) and hydrophilic polymer poly (triethylenglycol monomethacrylate (polyTEGMA) were tested as potential viscoelastics for intraoperative use in anterior segment surgery., Methods: PolyGLYMA was implanted into the anterior chamber in 5 rabbits, and 40% polyTEGMA in 16 rabbits. The eyes were enucleated 1 week to 3 months after the operation. The corneal endothelium was examined with specular microscopy, and then the whole eye histopathologically., Results: In all eyes of the polyGLYMA group, the clinical findings were characterized by a marked ciliary injection and severe secondary glaucoma, and the histologic ones by a marked inflammatory infiltration and thickening of Descemet's membrane in the anterior chamber angle. Specular microscopy revealed a decrease in the endothelial cell density and polymorphism of the endothelial cells. In the polyTEGMA group, the anterior segment and the fundus were physiologic all the time, and specular microscopy and histologic findings showed no degenerative and/or inflammatory changes., Conclusions: PolyGLYMA proved unsuitable for intracameral application in rabbits. The new polymer polyTEGMA is characterized by high biologic tolerance after its implantation into the anterior chamber of rabbits. PolyTEGMA 40% might be considered as a potential viscoelastic material in humans.

Objective: A model of estrogen (E)-induced rat anterior pituitary hyperplasia blocked partly by thyroid hormones (estradiol plus thyreoidin [ET]) and nearly completely by lisuride (estradiol plus lisuride [EL]) and thyreoidin plus lisuride combination (estradiol plus thyreoidin plus lisuride [ETL]) was used to test a computer image analysis program, LUCIA, for argyrophilic nucleolar organizer region (AgNOR) evaluation., Study Design: Nuclear and AgNOR area were measured in more than 700 cells in each experimental group. The nucleoli were also typed without the automated procedure., Results: Mean nuclear area was significantly higher in E and lower in T. In all groups with blocked hyperplasia (ET, EL, ETL) the mean nuclear area was lower than in T. Mean AgNOR area was significantly higher in E but also, to a lesser extent, in T. The ET combination produced a partly diminished mean AgNOR area as compared to E; a severe reduction was observed in the EL and ETL groups. In nucleolar typing, thyreoidin, lisuride and their combination inhibited the increase in large nucleoli with finely dispersed AgNORs induced by estradiol., Conclusion: The LUCIA image analysis program for AgNOR evaluation proved able to monitor the slight changes in AgNORs in thyroid hormones- and lisuride-inhibited, estradiol-induced rat anterior pitutary hyperplasia.

Photodynamic therapy (PDT) is now being used more frequently in carefully selected cases of malignancies. The drugs used for PDT are mostly derivatives of haematoporphyrine (HPD) and its active component photofrine II. Another compound prepared by total synthesis is meso-tetra-(4-sulfonatophenyl)-porphine (TPPS4) but its application in human medicine was rejected because of its neurotoxicity. Our TPPS4 was prepared by the method of Busby et al. in the modification of Jirsa and Kakac (1987). This product is purer and without neurotoxic effects. In this study, we concentrated our attention on the effect of TPPS4 on nephrotoxicity and its accumulation in some organs. As the parameters of toxic kidney damage we used urine levels of N-acetyl-beta-D-glucosaminidase (NAG), serum creatinine levels, glomerular filtration rate (GFR) and proteinuria. TPPS4 was administered i.v. in a dose of 25 mg/kg b.w. The animals were observed for 21 days after drug application. Urine and blood samples were collected over 24-hour periods on days 0, 5 and 21. The serum creatinine level was significantly higher only on day 5 (65.0+/-1.46 micromol/l vs 56.5+/-2.69 micromol/l on day 0, p<0.05). There were no significant changes in GFR, proteinuria or NAG activity in the urine during the experiment. AST serum activity was increased. We determined the concentration of TPPS4 (pmol/mg w.w.) in rat organs on the 21st day after the injection. The concentration of TPPS4 was high in kidneys (30.8+/-5.5), liver (13.5+/-2.0), lungs (11.7+/-4.6) and spleen (9.7+/-1.5), while the concentration in heart and brain was low. We conclude that TPPS4 has the highest concentration in the kidney 21 days after its administration and does not exert any nephrotoxic effects during this period.

This paper evaluates the clinical, radiological and histomorphologic effect of neoadjuvant chemotherapy in 37 patients with II B osteosarcomas. The results are compared according to the type of surgery, local recurrence and lung metastasis at a minimal follow up of five years in patients who underwent surgery at the orthopedic clinic in Prague Bulovka in 1982 - 1992. All patients continued with adjuvant chemotherapy after surgery. Bad clinical response (increase of circumference, decrease in range of motion and increase of pain) correlated with the bad histologic response evaluated according to the COSS criteria. Accurate evaluation of a complete radiological documentation (tumor calcification on plain radiographs and CT scans, decrease of tumor volume on plain radiographs and CT scans or MRI and the disappearance of pathologic vascularisation) can quite precisely estimate a good response to preoperative chemotherapy and indicate limb sparing surgery. The radiological evaluation, especially of an incomplete record, does not always fully correlate with the histomorphologic response. Good prognosis for long term survival was observed in patients with a more then 80% tumor cell necrosis. CT scans or MRI performed immediately before the beginning and at the end of preoperative chemotherapy are necessary for a reliable evaluation of tumor calcification and intramedullar tumor spread. The persistence or disappearance of pathologic vascularisation seems to be the most significant marker to evaluate residual vital tumor cells. A good radiological response enables a safe indication for a limb sparing procedure as an alternative to amputation. The radiological evaluation must be correlated with different histomorphologic osteosarcoma subtypes as well as with possible changes, especially in vascularisation, due to an incorrect biopsy or pathologic fracture. Key words: osteosarcoma, neoadjuvant chemotherapy, long term survival, indication for limb salvage.

The aim of the present work is to demonstrate of the influence of the adventitia on distribution of residual stresses in the human aorta. The biomaterial increase in media as well as in adventitia in the course of the aorta's growth is formed by an intussusceptive mechanism of growth. In children's aortas, formative elastin lamellae are wavy with high amplitude perpendicular to the aortic surface. In adults' aortas the waves become smoother (stepwise) towards the adventitia. Also introduced is the growth function, which characterizes the biomaterial growth and the interference between the media and adventitial layers. It is possible to expect an extraordinary variability in the formation of the aortic wall tissue in the course of its growth as a result of metabolic and humoral influences and magnitude of the residual stresses in the course of growth.

The author examined 119 patients having regular dialyzation treatment and a control group of 90 healthy subjects, divided into groups by decades. Depending on the intensity of pathological changes, they created four categories; the fifth comprised normal findings. The prepared from the bioptic material of the conjunctiva of two patients preparations which were examined for calcium and amyloid deposits. Pathological changes were found in 74.8%. The authors try to explain the cause of conjunctival and corneal changes, consistent with the theory of hastened ageing in chronic renal failure of patients treated by regular haemodialysis. The so far unique findings of amyloid of the conjunctiva could be possibly used in future for the diagnosis of amyloidosis instead biopsies.

The authors present the results of implantations of tricalcium phosphate of LASAK Co. Prague into defects of the long bones of 12 experimental dogs after an exposure time of 2,4 and 8 months. Seven modifications of the mentioned material were used in the form of granules, prisms and powder in a total of 18 implantations. In all instances specimens after implantation were taken which did not have macroscopic or microscopic signs of inflammatory reaction. X-ray did not reveal any clear spots round the material, signalizing an inflammatory of fibrous reaction. Microscopic examination confirmed excellent tolerance of the surrounding live tissue and osteoblastic activity in the immediate vicinity of the implants. After 8 months tricalcium phosphate was still present and only a smaller size of the particles suggested its absorbability. In the discussion the authors mention some possibilities of the clinical use of this material and contemplate on the problem of absorption. Key words: bone defect, tricalcium phosphate, bioactive glass ceramics, osteoinduction, absorbability of material.

The purpose of the study was to bring a contribution to the knowledge of physiology and pathophysiology of the bone mineral heteroionic exchange with respect to sodium ions and metabolic diseases, particularly bone diseases. The instrumental neutron activation analysis was employed to follow the ratio of contents Na/Ca in bone samples from dialyzed patients. A formerly elaborated method for the determination of the Na/Ca ratio in undecalcified bone tissue sections obtained from material embedded in polymethylmethacrylate was used. In the reference group the Na/Ca ratio was of 0.021 +/- 0.003, that in patients with the renal osteopathy was of 0.030 +/- 0.007. Results obtained in patients with different types of the renal osteopathy depending on the intensity of the impairment were discussed.

We studied the result of immunostaining for muscle specific actin in 15 chondroblastomas and observed distinct muscle actin positive chondroblasts and chondrocytes in five cases. In their cytoplasm actin positive cells contained bundles of microfilaments with focal densities on the ultrastructural level, but they differed from myofibroblasts in many aspects. Analogously to the terminology of myofibroblasts such cells can be probably designated as myochondroblasts having characteristic immunophenotype (vimentin, S-100 protein, NSE and muscle actin positivity).

Argyrophil Nucleolar Organizer Regions (AgNORs) reflect the ploidy and proliferative activity of cells. In a Czech made system of image analysis LUCIA-M (Laboratory Universal Computer Image Analysis-Medium version) we have created a macro for AgNORs evaluation. The process includes picture contrasting and processing, thresholding of nuclei and AgNORs, elimination of artifacts through restrictions and interactive editation. The relation of nuclei to AgNORs is realized using binary operations. The number of dots in a nucleus is counted using advanced morphology-homotopic marking. The object data (nuclear area, absolute and relative AgNOR area, mean equal diameter of nuclei, circularity) may be processed either in the system LUCIA itself or exporting the data into another statistic program, e.g. EXCEL. The choice of the most informative features measured for diagnostics and prognostics of tumours is a task for subsequent clinico-morphologic studies.

Argyrophil nucleolar organizer regions (AgNORs) were morphometrically evaluated in rat anterior pituitaries of control and oestrogenized rats using an automatized (LUCIA M--Laboratory Universal Computer Image Analysis Micro) and a non-automatized approaches to investigate not only the sensitivity and effectiveness of the automatized procedure but also the morphology of AgNORs in oestrogen-induced rat anterior pituitary hyperplasia. In the experimental oestrogen-induced rat anterior pituitary hyperplasia, the image analysis system LUCIA M was compared to a non-automatized morphometric procedure and proved to be very efficient and yielded analogical results. The AgNOR morphology in the oestrogenized pituitaries was characterized by an increase of the total AgNOR area and clustering of AgNORs in the large nucleoli.

In an unselected series of 32 biopsies of pulmonary neoplasms comprising 25 with neuroendocrine differentiation (11 carcinoids, 9 small cell cancers, and 5 undifferentiated carcinomas) a panel of antibodies (chromogranin-CG, neuron specific enolasis-NSE, S-100 protein, serotonin, bombesin, cytokeratins AE1-3, CAM5.2, epithelial membrane antigen-EMA) was used. This set was compared with results in another series of 7 non-small cell cancers (4 spinocellular and 3 adenomatous). The results of investigation of both the series were in agreement with the fact that there is no completely satisfactory marker of neuroendocrine differentiation. That is the reason why it is the best to use a spectrum of antibodies even in the routine praxis, as the proof of this differentiation in a neoplasm is most important for the differential diagnosis as well as for the therapy and prognosis.

A 37-year-old woman with brown bowel syndrome had yellowish-brown pigment in muscularis propria cells of removed intestine. The pigment occurred here and there in muscularis mucosae, in some arterial walls and in macrophages of submucosa. Its tinctorial characteristics were those of low oxidized lipofuscin. Its probably lysosomal localization was shown by electron microscopy.

Unlabelled: A study was undertaken to assess types of RO by a dynamic modification of osteoscintigraphy 53 pts dialyzed for 27-75 mths, 19-52 yrs old were divided, according to histological bone pictures, into 4 groups: I) 11 pts with hyperparathyroidism, II) 12 pts with osteomalacia, III) 11 pts with mixed RO, IV) 11 pts were after parathyroidectomy (PTE) and 13 controls., Investigations: the rate of 99mTc-Sn-HEDP accumulation in the skeleton, skeletal/background radioactivity index both registered for 60 min. (parameters K and P), serum levels of C-PTH, bone isoenzyme of alkaline phosphatase (bALP), acid phosphatase (ACP), free hydroxyproline (S-Hypro)., Results: 1. compared to controls: elevations of K and all biochemical parameters, P in groups I and III (p < 0.01 - < 0.001) were found. 2. Group 1 was characterized by the highest values of all parameters compared to groups II and IV (p < 0.01). 3. Linear relationships were found between K and bALP (p < 0.01), P and bALP, ACP, S-Hypro (p < 0.01) in pts of groups I, II, III. 4. PTE in group IV was followed by a decrease in all parameters (p < 0.01) compared to values of the same pts in group I. Aluminum osteopathy was present in 2/3 of cases in group II showing the lowest values of all parameters., Conclusion: DBS is a sensitive method for assessing bone turnover rate according to the degree of skeletal uptake of radionuclide. In this manner it is possible to determine both the type of RO and it's further development in repeated measurements.

Subcutaneous spindle cell hemangioendothelioma was observed in lower limb of a woman and forearm of a man. Cavernous and slit-like sinusoid vascular spaces were combined with solid spindle cell areas in both tumours. Spindle cells showed local immunohistochemical positivity of Factor XIII. Cavernous spaces comprised numerous thrombi in different phase of organization and sinusoids were full of lingering erythrocytes and lots of siderophages. Recurrence of the tumour occurred in the woman. Biologic nature of the lesion is not evident for the time being because its reactive proliferative character cannot be excluded.

An endobronchial metastasis of rectal carcinoma was found in a 62-year-old man three years after removal of the primary tumour. It imitated an aspirated foreign body and produced stromal foci of heterotopic ossification. Focal ossification was noticed in the revised primary tumour as well.

The histologic and ultrastructural features of a tibial lesion strongly resembling cementifying fibroma of the jaws are described. Histologically the lesion consisted of fibrous tissue containing small calcified spherules. In some areas acellular trabeculae or islets with lobulated margins of a cementlike substance occurred. Spherules and small calcified bodies were composed of apatite crystal depositions along the collagen fibers and were often in close contact with membrane-surrounded cytoplasmic processes resembling matrix vesicles. In fibrous tissue fibroblasts, myofibroblasts, and undifferentiated cells with numerous cytoplasmic processes and intracytoplasmic microfibrils were present. The character of the cellular component of this lesion and the presence of calcified spherules arranged in a manner rarely observed in fibrous dysplasia indicate a histogenic relationship between the two lesions.

The authors report three observations of rather extensive aggressive chondroblastoma and draw attention to difficulties of histological diagnosis, which result out of a less typical histological picture, in which signs of differentiation into cartilaginous tissue may be missing. Differential diagnosis may be facilitated by proper recognition of the cytologic character of chondroblasts by the positivity of S-100 protein, and by proving characteristic properties of chondroblasts in electronmicroscopic examination. In treating this type of tumors an increased risk of local recurrence (in one of our patients) and aggressive behaviour to surrounding tissues should be considered, exceptionally pulmonary metastases may develop, as was the case in one of our presented patients.

Histological examination of undecalcified specimens from different parts of skeletal remnants of king Ladislaus revealed a considerable degree of demineralization of a similar type as found in osteomalacia. This fact along with the finding of multiple osteolytic foci in different parts of the skeleton, and consistent with reports of the clinical picture of the disease made the authors present the hypothesis according to which the king may have suffered from so-called oncogenic osteomalacia. This bone disease may develop as a complication of some neoplastic disease incl. haemoblastoses and haemoblastomas. The authors think that with regard to the age of the king, historical reports and the multiplicity of osteolytic lesions that the most plausible hypothesis is that of oncogenic osteomalacia associated with some type of malignant non-Hodgkin lymphoma.

The first part of the paper on the isoelastic POLDI prosthesis is concerned with animal experiments on dogs. The objective of the experiment was to prove the assumed properties of these endoprostheses, described by authors who use them in different clinical departments all over the world. The precise experimental procedure and exact histological conclusions mentioned in this investigation confirm the majority of these hypothetical qualities. In the discussion the authors compare the relatively small number of published experimental work with the conslusions of their own investigation. They mention the satisfactory osteoplastic activity of bone in the immediate vicinity of the rods. This applies to animals. As apparent in the second part of this paper the findings in human medicine may differ in some ways. Key words: endoprosthesis of the hip joint, isoelasticity, animal experiment, osteoplastic reaction, cervicocapital endoprosthesis of the hip joint.

Spontaneous settling of consulting centres for special fields in pathology is recommended in advance to general reform of the Czechoslovak medical services. Principles of their functioning and main tasks are outlined.

The authors present a review of the contemporary problem of non-cemented alloplasty of the hip joint. They compare the advantages and disadvantages of cemented and non-cemented endoprostheses of the hip joint in relation to possible loosening and possible re-operation and with regard to the surgical technique. The negative action of bone cement is divided into two groups: 1. immediate effects which act on surrounding tissues and the patient's organism during operation. 2. late effects which involve abrasion and the phagocytic response to small cement fragments and the formation of osteoaggressive granulations. These late effects are demonstrated on histological material. The authors emphasize that non-cemented alloplasty has also some pitfalls which involve in particular higher demands on the accuracy of the surgical technique and, no doubt, more severe haemorrhage. The main advantages are according to the authors the elimination of negative effects of bone cement, in particular late effects. The authors tried to classify the contemporary spectrum of available non-cemented implants with regard to their design, materials and surface finish.

A programme for controlled automated histomorphometric evaluation of bone biopsies, connected with authors' results with semiautomated program, introduces new technology as well as new principle. It is based on a digitalization of microscopic picture in videocamera followed by controlled automated computerized processing of the picture. A further simplification of the evaluation process is achieved by eliminating a time consuming and not quite precise over-drawing of the picture on a digitalization desk.

To evaluate trabecular bone formations of active acromegalic patients the authors used the method of histomorphometry and correlated the calculated variables of the trabecular volume (V), osteoid volume (Vos), osteoid surface (Sf) and width of the osseous trabeculum (MTT) with STH levels, the patients' age and the period of the acromegalic process. No correlations were found between Vos, Sf, MTT and STH levels, age and the length of the case-history. There were negative correlations (p less than 0.05) between the trabecular volume (V) and the period of the case-history and trabecular volume (V) and the patients' age. From the results it may be concluded that STH does not influence the balance between resorption and formation of the acromegalic spongiosa in favour of formation.

The authors used static histomorphometric parameters obtained by processing of bioptic bone specimens for comparison of normal and acromegalic spongious bone. Parameters of the bone volume (V), osteoid volume (Vos), the extent of osteoid bone surfaces (Sf) in the two groups do not differ statistically. The two groups do not differ as to age distribution. The width of bone trabeculae is greater in acromegalic bone; the difference as compared with normal bone specimens is statistically significant (p less than 0.05). The authors conclude that STH in acromegalics subjects does not stimulate osteoid production in trabecular bone to shift the balance between bone resorption and formation significantly in favour of formation. Only restructuring of trabecular acromegalic bone occurs.

Histological examination of bone samples from osteopathic patients with subsequent histomorphometric evaluations needs procedures a bit different from those of bioptic routine. They are introduced and summarized according to author's experience. A complete examination necessitates usage of technique for undecalcified samples after previous administering of tetracycline and of a sort of histomorphometric procedure. Routine diagnosis will manage even with decalcified samples supposing they were silver impregnated before decalcification; tetracycline as well as some metals (e.g. aluminium and iron) deposited in the bone will be eluted during decalcification. There are presented definitions and mean values of basic parameters evaluated in histomorphometric analysis.

Histochemical study of 155 bone biopsies from dialyzed patients revealed 43 cases with aluminium deposits in bone trabeculae localized along the mineralization line or in phagolysosomes of bone marrow macrophages. Aluminium was limited to macrophages in 5 cases, to mineralization line in 23 cases, and found in both localities in 15 patients. Patients with a positive finding mostly had osteomalacia (8 times) which was combined in some cases (35 times) with mild fibrous osteodystrophy. Authors failed to prove histochemically positive deposits in dialyzed patients with serious parathyroidism. Simultaneous deposits of aluminium and hemosiderin were found in the mineralization line in three patients. Bone deposition of aluminium seems to influence somehow the bone lesion but precise interpretation of the phenomenon has not been given.

Analysis of 12 observations with a typical histological appearance revealed only in one case a local relapse. In two tumours the authors found a structure encountered in aneurysmatic osseous cysts and in one case, due, to the presence of a major number of osteoclasts, the differential diagnosis with a giant-cell bone tumour was rendered more difficult. Electron microscopic examination revealed that tumours of this type are formed by cartilage cells differentiated in different ways. In cellular areas two main types of cells are found: light and dark ones. Some of the elements of both types had multilobular nuclei.

8 secondary chondrosarcomas in 7 patients with diaphyseal aclasia are reported. Effective diagnostic imaging is a key to early operative removal of the tumours. Angiography proved to be highly useful in tracing the malignant character and true extension of the lesion. Also skeletal nuclear investigations support the diagnosis. The necessity of regular checkups of all patients suffering from diaphyseal aclasia is stressed.