Acral lentiginous melanoma: a single-centre retrospective review of four decades in East-Central Europe

BACKGROUND

Acral lentiginous melanoma (ALM) occurs on the palms, soles and subungual surface and has poor prognosis. It is uncommon in the Caucasian population and has remained unreported in East-Central Europe.

OBJECTIVES

Our aim was to collect data from East-Central Europe by analysing the demographic and clinicopathologic features of patients with ALM and comparing data with the reports in literature.

METHODS

We conducted a single-centre, retrospective review between 1976 and 2016 at one of the largest melanoma referral centres in Hungary.

RESULTS

We identified 176 patients with ALM (3.83%) from 4593 patients with melanoma (mean age: 66.2 years). The tumours were mainly located on the lower extremities (88.63%). The mean Breslow tumour thickness was 3.861 mm, 37.50% of the tumours were thicker than 4.00 mm, and 71.6% exhibited microscopic ulceration. Nearly one-third of the patients underwent sentinel lymph node (SLN) biopsy, and 60.3% of the biopsies were positive for metastasis. The positive SLN status was associated with significantly thick tumours and reduced survival. Patients with ALM had 5- and 10-year overall survival rates of 60.5% and 41.6%, respectively. The mean delay in diagnosis was 18 months after the discovery of skin tumours. In multivariate analyses, age, tumour thickness and distant metastasis were independent risk factors for poor survival (P < 0.001).

CONCLUSIONS

Our study, which is the first single-centre report in East-Central Europe focusing on ALM, confirms that patient and tumour characteristics and prognostic factors are similar with previous literature data involving Caucasians; however, tumour thickness and survival suggest even worse prognosis.

Presence of varicella zoster virus in zosteriform leukaemia cutis

Leukaemia cutis is a relatively rare manifestation in chronic lymphocytic leukaemia, characterized by a diverse morphology of skin lesions. We report two patients who developed zosteriform skin symptoms; however, the histological analysis revealed leukaemia infiltration as the cause of their symptoms. Contrary to previous reports, varicella zoster virus DNA was detectable in the lesions. These findings suggest that varicella zoster virus plays an active role in the development of zosteriform leukaemia cutis.

Dysplastic Nevi are a Risk Factor for Uveal Melanoma

Many studies have characterized the phenotypic features of individuals who are likely to develop cutaneous melanoma. One of the major items included in melanoma risk assessment has been the presence of clinically atypical nevi (dysplastic nevi). This study assessed the number of subjects with dysplastic nevi in groups of patients with uveal melanoma or cutaneous melanoma and in a group of volunteer controls. The SPSS program was used to calculate the odds ratios (hereafter called relative risks; RR) and 95% confidence intervals (C) in melanoma patients and controls. The RR was 4.36 for uveal melanoma (95% Cl 1.84-10.36) and 4.22 for cutaneous melanoma (95% Cl 1.81-9.84). These results suggest that cutaneous dysplastic nevi are a significant risk factor for uveal melanoma.

Further evidence for microtubule-independent dimerization of TPPP/p25

Tubulin Polymerization Promoting Protein (TPPP/p25) is a brain-specific disordered protein that modulates the dynamics and stability of the microtubule network by its assembly promoting, cross-linking and acetylation enhancing activities. In normal brain it is expressed primarily in differentiated oligodendrocytes; however, at pathological conditions it is enriched in inclusions of both neurons and oligodendrocytes characteristic for Parkinson’s disease and multiple system atrophy, respectively. The objective of this paper is to highlight a critical point of a recently published Skoufias’s paper in which the crucial role of the microtubules in TPPP/p25 dimerization leading to microtubule bundling was suggested. However, our previous and present data provide evidence for the microtubule-independent dimerization of TPPP/p25 and its stabilization by disulphide bridges. In addition, our bimolecular fluorescence complementation experiments revealed the dimerization ability of both the full length and the terminal-free (CORE) TPPP/p25 forms, however, while TPPP/p25 aligned along the bundled microtubule network, the associated CORE segments distributed mostly homogeneously within the cytosol. Now, we identified a molecular model from the possible ones suggested in the Skoufias’s paper that could be responsible for stabilization of the microtubule network in the course of the oligodendrocyte differentiation, consequently in the constitution of the myelin sheath.

Characterisation of bioenergetic pathways and related regulators by multiple assays in human tumour cells

Background

Alterations in cellular metabolism are considered as hallmarks of cancers, however, to recognize these alterations and understand their mechanisms appropriate techniques are required. Our hypothesis was to determine whether dominant bioenergetic mechanism may be estimated by comparing the substrate utilisation with different methods to detect the labelled carbon incorporation and their application in tumour cells.

Methods

To define the bioenergetic pathways different metabolic tests were applied: (a) measuring CO₂ production from [1-¹⁴C]-glucose and [1-¹⁴C]-acetate; (b) studying the effect of glucose and acetate on adenylate energy charge; (c) analysing glycolytic and TCA cycle metabolites and the number of incorporated ¹³C atoms after [U-¹³C]-glucose/[2-¹³C]-acetate labelling. Based on [1-¹⁴C]-substrate oxidation two selected cell lines out of seven were analysed in details, in which the highest difference was detected at their substrate utilization. To elucidate the relevance of metabolic characterisation the expression of certain regulatory factors, bioenergetic enzymes, mammalian target of rapamycin (mTOR) complexes (C1/C2) and related targets as important elements at the crossroad of cellular signalling network were also investigated.

Results

Both [U-¹³C]-glucose and [1-¹⁴C]-substrate labelling indicated high glycolytic capacity of tumour cells. However, the ratio of certain ¹³C-labelled metabolites showed detailed metabolic differences in the two selected cell lines in further characterisation. The detected differences of GAPDH, β-F1-ATP-ase expression and adenylate energy charge in HT-1080 and ZR-75.1 tumour cells also confirmed the altered metabolism. Moreover, the highly limited labelling of citrate by [2-¹³C]-acetate—representing a novel functional test in malignant cells—confirmed the defect of TCA cycle of HT-1080 in contrast to ZR-75.1 cells. Noteworthy, the impaired TCA cycle in HT-1080 cells were associated with high mTORC1 activity, negligible protein level and activity of mTORC2, high expression of interleukin-1β, interleukin-6 and heme oxygenase-1 which may contribute to the compensatory mechanism of TCA deficiency.

Conclusions

The applied methods of energy substrate utilisation and other measurements represent simple assay system using ¹³C-acetate and glucose to recognize dominant bioenergetic pathways in tumour cells. These may offer a possibility to characterise metabolic subtypes of human tumours and provide guidelines to find biomarkers for prediction and development of new metabolism related targets in personalized therapy.

Tubulin acetylation promoting potency and absorption efficacy of deacetylase inhibitors

BACKGROUND AND PURPOSE

Histone deacetylase 6 (HDAC6) and silent information regulator 2 (SIRT2) control the dynamics of the microtubule network via their deacetylase activities. Tubulin polymerization promoting protein (TPPP/p25) enhances microtubule acetylation by its direct binding to HDAC6. Our objective was to characterize the multiple interactions of the deacetylases and to establish the inhibitory potency and the pharmacokinetic features of the deacetylase inhibitors, trichostatin A (TSA) and AGK2.

EXPERIMENTAL APPROACH

The interactions of deacetylases with tubulin and TPPP/p25 were quantified by elisa using human recombinant proteins. The effect of inhibitors on the tubulin acetylation was established in HeLa cells transfected with pTPPP and CG-4 cells expressing TPPP/p25 endogenously by celisa (elisa on cells), Western blot and immunofluorescence microscopy. The pharmacokinetic features of the inhibitors were evaluated by in situ kinetic modelling of their intestinal transport in rats.

KEY RESULTS

Deacetylases interact with both tubulin and TPPP/p25, notwithstanding piggy-back binding of HDAC6 or SIRT2 to the TPPP/p25-associated tubulin was established. Much higher inhibitory potency for TSA than for AGK2 was detected in both HeLa and CG-4 cells. Pioneer pharmacokinetic studies revealed passive diffusion and diffusion coupled with secretion for TSA and AGK2 respectively. Both inhibitors exhibited greater permeability than some other well-established drugs.

CONCLUSIONS AND IMPLICATIONS

TPPP/p25-directed deacetylase inhibition provides mechanisms for the fine control of the dynamics and stability of the microtubule network. Deacetylase inhibitors with chemical structures similar to TSA and AGK2 appear to be excellent candidates for oral drug absorption.

Moonlighting microtubule-associated proteins: regulatory functions by day and pathological functions at night

The sensing, integrating, and coordinating features of the eukaryotic cells are achieved by the complex ultrastructural arrays and multifarious functions of the cytoskeletal network. Cytoskeleton comprises fibrous protein networks of microtubules, actin, and intermediate filaments. These filamentous polymer structures are highly dynamic and undergo constant and rapid reorganization during cellular processes. The microtubular system plays a crucial role in the brain, as it is involved in an enormous number of cellular events including cell differentiation and pathological inclusion formation. These multifarious functions of microtubules can be achieved by their decoration with proteins/enzymes that exert specific effects on the dynamics and organization of the cytoskeleton and mediate distinct functions due to their moonlighting features. This mini-review focuses on two aspects of the microtubule cytoskeleton. On the one hand, we describe the heteroassociation of tubulin/microtubules with metabolic enzymes, which in addition to their catalytic activities stabilize microtubule structures via their cross-linking functions. On the other hand, we focus on the recently identified moonlighting tubulin polymerization promoting protein, TPPP/p25. TPPP/p25 is a microtubule-associated protein and it displays distinct physiological or pathological (aberrant) functions; thus it is a prototype of Neomorphic Moonlighting Proteins. The expression of TPPP/p25 is finely controlled in the human brain; this protein is indispensable for the development of projections of oligodendrocytes that are responsible for the ensheathment of axons. The nonphysiological, higher or lower TPPP/p25 level leads to distinct CNS diseases. Mechanisms contributing to the control of microtubule stability and dynamics by metabolic enzymes and TPPP/p25 will be discussed.

Detection of a rare CDKN2A intronic mutation in a Hungarian melanoma-prone family and its role in splicing regulation

BACKGROUND

The major locus for melanoma predisposition is the cell cycle regulatory CDKN2A gene on chromosome 9p21. However, the frequency of germline coding mutations of the CDKN2A gene is lower than expected in melanoma-prone families linked to chromosome 9p21.

OBJECTIVES

To investigate whether the rare IVS1+37 G/C intronic mutation of the CDKN2A gene, recently identified in a Hungarian melanoma-prone family, influences mRNA splicing regulation.

METHODS

CDKN2A minigenes containing the wild-type and the mutant intronic sequence were created and transfected into HeLa cells with the aim of studying the mRNA transcripts.

RESULTS

The results revealed the emergence of a differential splicing pattern from the wild-type and the mutant minigene, suggesting that this mutation may alter the splicing of CDKN2A primary mRNA and therefore might have a pathogenetic role in familial melanoma.

CONCLUSIONS

We believe that these results confirm the importance of the identification and characterization of CDKN2A intronic mutations with a view to improving our understanding of the pathogenesis, and explain why the frequency of germline coding mutations of the CDKN2A gene is lower than expected in melanoma-prone families linked to chromosome 9p21.

Interactions of enolase isoforms with tubulin and microtubules during myogenesis

Enolase is a glycolytic enzyme, expressed as cell-type specific isoforms in higher vertebrates. Herein we demonstrated for the first time that enolase isoforms interact with microtubules during muscle satellite cell differentiation. While in undifferentiated myoblasts the ubiquitous alphaalpha enolase isoform, expressed at high level, exhibited extensive co-localization with microtubules, the muscle-specific betabeta isoform, expressed at low level, did not. During differentiation, the level of beta subunit increased significantly; the alpha and beta enolase immunoreactivities were detected both in cytosol and along the microtubules. We identified tubulin from muscle extract as an interacting protein for immobilized betabeta enolase. ELISA and surface plasmon resonance measurements demonstrated the direct binding of enolase isoforms to tubulin with an apparent KD below the micromolar range, and indicated that the presence of 0.8 mM 2-phosphoglycerate abolished the interaction. Our data showed that, at various stages of myogenic differentiation, microtubules were decorated by different enolase isoforms, which was controlled by the abundance of both partners. We suggest that the binding of enolase to microtubules could contribute to the regulation of the dynamism of the cytoskeletal filaments known to occur during the transition from myoblast to myotubes.

TPPP/p25: from unfolded protein to misfolding disease: prediction and experiments

TPPP/p25, the first representative of a new protein family, identified as a brain-specific unfolded protein induces aberrant microtubule assemblies in vitro, suppresses mitosis in Drosophila embryo and is accumulated in inclusion bodies of human pathological brain tissues. In this paper, we present prediction and additional experimental data that validate TPPP/p25 to be a new member of the "intrinsically unstructured" protein family. The comparison of these characteristics with that of alpha-synuclein and tau, involved also in neurodegenerative diseases, suggested that although the primary sequences of these proteins are entirely different, there are similarities in their well-defined unstructured segments interrupted by "stabilization centres", phosphorylation and tubulin binding motives. SK-N-MC neuroblastoma cells were transfected with pEGFP-TPPP/p25 construct and a stable clone denoted K4 was selected and used to establish the effect of this unstructured protein on the energy state/metabolism of the cells. Our data by analyzing the mitochondrial membrane polarization by fluorescence microscopy revealed that the high-energy phosphate production in K4 clone is not damaged by the TPPP/p25 expression. Biochemical analysis with cell homogenates provided quantitative data that the ATP level increased 1.5-fold and the activities of hexokinase, glucosephosphate isomerase, phosphofructokinase, triosephosphate isomerase and glyceraldehyde-3-phosphate dehydrogenase were 1.2 to 2.0-fold higher in K4 as compared to the control. Our modelling using these data and rate equations of the individual enzymes suggests that the TPPP/p25 expression stimulates glucose metabolism. At pathological conditions TPPP/p25 is localized in inclusion bodies in multiple system atrophy, it tightly co-localizes with alpha-synuclein, partially with tubulin and not with vimentin. The previous and the present studies obtained with immunohistochemistry with pathological human brain tissues rendered it possible to classify among pathological inclusions on the basis of immunolabelling of TPPP/p25, and suggest this protein to be a potential linkage between Parkinson's and Alzheimer's diseases.

A cost-effective screening method for pesticide residue analysis in fruits, vegetables, and cereal grains

This paper reports the results of studies performed to investigate the potential of applying thin layer chromatography (TLC) detection in combination with selected extraction and cleanup methods, for providing an alternative cost-effective analytical procedure for screening and confirmation of pesticide residues in plant commodities. The extraction was carried out with ethyl acetate and an on-line extraction method applying an acetone-dichloromethane mixture. The extracts were cleaned up with SX-3 gel, an adsorbent mixture of active carbon, magnesia, and diatomaceous earth, and on silica micro cartridges. The Rf values of 118 pesticides were tested in eleven elution systems with UV, and eight biotest methods and chemical detection reagents. Cabbage, green peas, orange, and tomatoes were selected as representative sample matrices for fruits and vegetables, while maize, rice, and wheat represented cereal grains. As an internal quality control measure, marker compounds were applied on each plate to verify the proper elution and detection conditions. The Rf values varied in the different elution systems. The best separation (widest Rf range) was achieved with silica gel (SG)--ethyl acetate (0.05-0.7), SG--benzene, (0.02-0.7) and reverse phase RP-18 F-254S layer with acetone: methanol: water/30:30:30 (v/v) (0.1-0.8). The relative standard deviation of Rf values (CV(Rf)) within laboratory reproducibility was generally less than 20%, except below 0.2 Rf, where the CVRf rapidly increased with decreasing Rf values. The fungi spore inhibition, chloroplast inhibition, and enzyme inhibition were found most suitable for detection of pesticides primarily for confirming their identity or screening for known substances. Their use for determination of pesticide residues in samples of unknown origin is not recommended.

TPPP/p25 promotes tubulin assemblies and blocks mitotic spindle formation

Recently, we isolated from bovine brain a protein, TPPP/p25 and identified as p25, a brain-specific protein that induced aberrant tubulin assemblies. The primary sequence of this protein differs from that of other proteins identified so far; however, it shows high homology with p25-like hypothetical proteins sought via blast. Here, we characterized the binding of TPPP/p25 to tubulin by means of surface plasmon resonance; the kinetic parameters are as follows: kon, 2.4 x 10(4) M(-1) x s(-1); koff, 5.4 x 10(-3) s(-1); and Kd, 2.3 x 10(-7) M. This protein at substoichometric concentration promotes the polymerization of tubulin into double-walled tubules and polymorphic aggregates or bundles paclitaxel-stabilized microtubules as judged by quantitative data of electron and atomic force microscopies. Injection of bovine TPPP/p25 into cleavage Drosophila embryos expressing tubulin-GFP fusion protein reveals that TPPP/p25 inhibits mitotic spindle assembly and nuclear envelope breakdown without affecting other cellular events like centrosome replication and separation, microtubule nucleation by the centrosomes, and nuclear growth. GTP counteracts TPPP/p25 both in vitro and in vivo.

Distinct behavior of mutant triosephosphate isomerase in hemolysate and in isolated form: molecular basis of enzyme deficiency

In a Hungarian family with severe decrease in triosephosphate isomerase (TPI) activity, 2 germ line-identical but phenotypically differing compound heterozygote brothers inherited 2 independent (Phe240Leu and Glu145stop codon) mutations. The kinetic, thermodynamic, and associative properties of the recombinant human wild-type and Phe240Leu mutant enzymes were compared with those of TPIs in normal and deficient erythrocyte hemolysates. The specific activity of the recombinant mutant enzyme relative to the wild type was much higher (30%) than expected from the activity (3%) measured in hemolysates. Enhanced attachment of mutant TPI to erythrocyte inside-out vesicles and to microtubules of brain cells was found when the binding was measured with TPIs in hemolysate. In contrast, there was no difference between the binding of the recombinant wild-type and Phe240Leu mutant enzymes. These findings suggest that the missense mutation by itself is not enough to explain the low catalytic activity and "stickiness" of mutant TPI observed in hemolysate. The activity of the mutant TPI is further reduced by its attachment to inside-out vesicles or microtubules. Comparative studies of the hemolysate from a British patient with Glu104Asp homozygosity and with the platelet lysates from the Hungarian family suggest that the microcompartmentation of TPI is not unique for the hemolysates from the Hungarian TPI-deficient brothers. The possible role of cellular components, other than the mutant enzymes, in the distinct behavior of TPI in isolated form versus in hemolysates from the compound heterozygotes and the simple heterozygote family members is discussed.

Role of the basement membrane in tumor cell dormancy and cytotoxic resistance

OBJECTIVES AND METHODS

Tumor dormancy and resistance to cytotoxic agents are key limiting events in the treatment of malignant diseases. To determine whether both are influenced by the extracellular milieu in which tumors reside, HT1080 human fibrosarcoma, MCF-7 breast carcinoma and OSCORT osteosarcoma cell proliferation, viability, apoptosis and cytoreductive-treatment-induced death were investigated in the presence or absence of extracellular matrix (ECM).

RESULTS

ECM-adherent, but not plastic-adherent HT1080 cells formed a multicellular network accompanied by reduced proliferation and lowered DNA synthetic capacity. The number of cells in S-phase was dramatically reduced. Viable cells entered a state of dormancy reminiscent of that observed in the step of metastasis after extravasation, i.e. prior to the initiation of progressive growth. Such ECM-induced dormancy could be reversed by plating cells on plastic, but only after a 48-hour lag period. No difference was indicated in clonogenicity of HT1080 cells originated from plastic or ECM gel. However, the cells released from ECM gel showed significantly reduced migration ability. The resistance of anchored cells against cytotoxic damage was increased by ECM gel. Examination of cytoreductive treatment revealed that ECM adherence at the time of injury is partially protective, a property which was also moderately apparent when injured cells were transferred to the basement membrane.

CONCLUSIONS

Taken together, these results suggest that the ECM plays a key role in tumor dormancy and cytotoxic resistance, both explorable at the molecular level using our in vitro model system.

Cutaneous dysplastic naevi in uveal melanoma patients: markers for prognosis?

We have previously reported that the presence of cutaneous dysplastic naevi is a risk factor for uveal melanoma. In the present study our goal was to determine the incidence of different histopathological features of uveal melanoma among 91 patients with or without cutaneous dysplastic naevi. Statistical analysis revealed that the presence of cutaneous dysplastic naevi in uveal melanoma patients is associated with an increased incidence of the prognostically worst forms of uveal melanoma (epithelioid or mixed cell type melanomas). The relative risk was 5.97 (95% confidence interval 1.61-22.14). Our results suggest that the presence of cutaneous dysplastic naevi is not only a risk factor but also a prognostic factor for uveal melanoma.

Juvenile pemphigus foliaceus

A 7-year-old girl with generalized erythematous, scaling plaques and vesiculobullous lesions on the extremities was diagnosed as having pemphigus foliaceus. Lesional direct immunofluorescence revealed intercellular IgG, IgA and C3 deposition. The patient's serum gave positive reactions against one epitope of desmoglein 3 and the epitope of desmoglein 1 in enzyme-linked immunosorbent assays, but the blood sample for indirect immunofluorescence did not display any circulating antibodies. The patient was successfully treated systemically with prednisolone and dapsone. Currently, she is taking dapsone, 12.5 mg daily. She has been free of lesions for the last 3 years.

The antiproliferative action of a melphalan hexapeptide with collagenase-cleavable site

PURPOSE

The objective of the present study was to examine the relevance of collagenase in the antitumor action of a melphalan peptide (MHP) with a collagenase-cleavable sequence. The question was addressed as to whether collagenase may act as an activator or a target in the antiproliferative mechanism of MHP.

METHODS

Melphalan was inserted into peptides representing the sequence Pro-Gln-Gly-Ile-Ala.Gly of the collagenase-cleavable site in collagens. Changes in growth and collagenase IV activities of HT-1080, HT-29, HT-168, and MCF-7 cell cultures were investigated.

RESULTS

The present investigations provide data indicating that Pro-Gln-Gly-Ile-Mel-Gly (melphalan hexapeptide, MHP) is a substrate for both bacterial and 72-kDa type IV collagenases and that in this way it can generate Ile-Mel-Gly (melphalan tripeptide, MTP) of higher cytotoxic potency. Indeed, the formation of MTP was detected in the conditioned medium of HT-1080, a collagenase IV-producing human fibrosarcoma. In a comparison of equimolar concentrations of melphalan and its two peptide derivatives (MHP and MTP), superior antiproliferative action of MTP was seen in HT-29, HT-1080, and HT-168 tumor cell cultures. However, the relatively modest cytostatic actions of MHP were increased when bacterial collagenase was added to the cell cultures. After melphalan treatment, reduced levels of both 92 and 72-kDa type IV collagenases were seen in the HT-1080 cell cultures. However, the reduction of collagenase activity and the cell counts did not run parallel in the MTP- or MHP-treated cultures; indeed, collagenase activity related to cell numbers showed an elevated level.

CONCLUSIONS

As the conversion of MHP to the more toxic MTP was detected in the presence of collagenases, it is possible that collagenase-directed activation of prodrugs may be a promising approach for the development of more selective cytostatic drugs against malignant tumors with high collagenase activities.

Inhibition of anaphylactic shock by gadolinium chloride-induced Kupffer cell blockade

Data in the literature concerning the role of macrophages in anaphylaxis are contradictory. In the present study, the effect of macrophage blockade induced by gadolinium chloride (GdCl3) on anaphylactic shock is investigated. Our observations show that GdCl3 prevents lethal anaphylactic shock in mice sensitized to ovalbumin. Gadolinium chloride given i.v. in a dose of 1 mg/100 g body weight 24 or 48 h before the elicitation of anaphylactic shock resulted in 80% survival, compared with the 43% survival in the control group. The same dose of this rare-earth metal salt also greatly reduced the mortality in mice sensitized with ovalbumin containing Bordetella pertussis vaccine, and similarly abrogated the symptoms of anaphylaxis, including the accumulation of serotonin and histamine in the liver. The results suggest that macrophages play an important role in mouse anaphylaxis.

Proteoglycans in the compressed region of human tibialis posterior tendon and in ligaments

Proteoglycan content and tissue morphology were examined in tendons and ligaments from 24 cadavers, ranging in age at the time of death from 1.5 months to 83 years. The region of the human tibialis posterior tendon that passes under the medial malleolus was characterized by cells having a rounded shape, positive staining with alcian blue, and higher glycosaminoglycanuronic acid content than in the more proximal region of the same tendon. Analysis of proteoglycans by sodium dodecyl sulfate/polyacrylamide gel electrophoresis indicated that the predominant small proteoglycan of the proximal/tensional region was decorin, whereas two types of small proteoglycans (decorin and biglycan) and large proteoglycans were present in the region passing under the medial malleolus and presumably subjected to compressive and shear forces in addition to tension. The pattern of proteoglycan accumulation in the compressed region of tendon was basically similar for all individuals and showed no distinctive trends related to age after puberty. In terms of type and amount of proteoglycan, the patellar tendon was like the tensional region of the tibialis posterior. Glycosaminoglycan content in the lateral collateral ligament and anterior cruciate ligament, however, was twofold higher than in the tendons. The ligaments contained large as well as small proteoglycans, just as in the compressed region of tendon.

Relationships between the chromatographic retention data and the effects of nucleoside derivatives in highly metastatic 3LL cells

The effect of 21 nucleoside derivatives on the [3H]-thymidine cellular uptake and on the incorporation into DNA of highly metastatic 3LL (Lewis lung carcinoma) cells has been measured. Hydrophobic and hydrophilic molecular parameters (the adsorption capacity, specific adsorption surface, lipophilicity and specific hydrophobic surface area) have been determined by using thin-layer chromatography. Stepwise linear regression analysis and principal component analysis have been applied in order to reveal the relationships between the molecular parameters and the effect of the nucleoside derivatives on highly metastatic 3LL cells. The first principal component obtained from the measured activity data could be attributed to the change of [3H]-thymidine cellular uptake caused by the nucleoside, while the second principal component could be regarded as the measure of the effect on the DNA incorporation of [3H]-thymidine. The effect of the nucleosides on the [3H]-thymidine uptake could be explained by the specific hydrophobic and adsorption surface area of the nucleoside, on the other hand the effect on the DNA incorporation could be described by the adsorption characteristics (specific hydrophilic surface area and adsorption capacity) of the derivatives.

Investigations on the antitumor effect and mutagenicity of alpha-MSH fragments containing melphalan

alpha-MSH fragments containing melphalan were tested in vivo on L1210 leukemia and on human amelanotic melanoma xenograft in mice and in vitro on human amelanotic melanoma cell lines. The compounds exhibit significant antitumor activity, but no selectivity in targeting of melanoma can be achieved. There is a difference between melphalan and the melphalyl-peptide in their action on protein synthesis. The peptide derivatives also are less mutagenic than melphalan, according to the SCE assay, furnishing further evidence for the positive effect of natural carrier molecules.

Modulation of membrane phenotype, matrix adhesion and microinvasiveness of metastatic tumour cells by HUdR

The effect of HUdR, proved to be anti-metastatic in vivo, was studied in vitro on cell proliferation, nucleoside uptake, membrane fluidity, expression of galactosylated glycans and proteoglycans in metastatic HM tumour cells. The observed increase in membrane fluidity and the suppression of nucleoside transport were early events of the HUdR action followed by decrease of galactosylated glycan and HSPG expression. However, these changes did not influence the proliferation capacity of the cells at the concentrations studied. As a consequence of the membrane alterations a reduced adhesiveness and spreading on extracellular matrix components was detected. In addition, the HUdR treated HM cells showed reduced capacity to invade fibroblast monolayers in vitro. Based on these observations, HUdR could be the prototype of new anti-metastatic agents acting at the level of tumour-host interaction.

Keratinocyte grafting: a new means of transplantation for full-thickness wounds

Twenty adult individuals with chronic leg ulcers caused by venous insufficiency, and 5 patients with full-thickness burns were treated. Twenty of the patients (15 with leg ulcers and 5 with burns) were grafted with separated autologous keratinocytes. In these cases the cells were fixed to the wound bed by a fibrin net. Five other patients (with leg ulcers) were treated with fibrin without keratinocytes. In 16 of the 20 patients grafted with keratinocytes in a fibrin net, the defect healed completely in 14 to 21 days. On the other hand, the fibrin net without keratinocytes failed to significantly accelerate the process of reepithelialization. Our experience suggests that a rapid healing of full-thickness skin defects can be achieved through keratinocyte grafting.

[Use of solid fat in dry mixed feed for rainbow trout (Salmo gairdneri). 2. Fatty acid composition of feed and tissue lipids]

The effect of supplemental dietary fat on the fatty acid composition of some tissue lipids of rainbow trout fingerlings was studied. Data showed that dietary fatty acids were deposited nearly unchanged in the adipose tissue. The level of eicosapentaenoic acid, however, dropped significantly. Muscle showed remarkable capacity for deposition of dietary fat, while only minor changes were observed in the fatty acid composition of liver lipids. Levels of some polyenoic acid (e.g. 18: 2 omega 6, 20:4 omega 6, 20:5 omega 3, 22:6 omega 3) showed, that the fish converted lower unsaturated fatty acids to highly unsaturated fatty acids. It was observed that dietary acids had little effect on the fatty acid composition of tissue phospholipids. This result shows, that 17% fat in the diet are tolerated by trout, without alterations in the fat composition of the liver tissue. Probably the low rearing temperature (11 degrees C) had a more pronounced effect on the fatty acid composition of phospholipids than the diet.

Platelet sensitivity to adenosine diphosphate and to prostacyclin in diabetic pregnancies

Platelet sensitivity to adenosine diphosphate (ADP) and to prostacyclin (PGI2) was studied in normal and diabetic pregnant women. The threshold concentrations of ADP inducing the second phase of aggregation were used to determine the platelet sensitivity to PGI2. The sensitivity of platelets to ADP increased in both groups in the second trimester, thereafter it decreased both in normal and diabetic pregnancies. In contrast, sensitivity to PGI2 increased in the last trimester of pregnancy. No difference could be observed between diabetic and normal groups. The similarity of the results between the two groups could be explained by the normoglycaemic state of well-controlled diabetic pregnant women.

[Calcification of glenoid labrum in the aged (author's transl)]

200 radiographs of 100 elderly patients considering themselves to be fit are compared. Calcification of the glenoid labrum at the shoulder is due to age, without clinical importance, a radiologic finding. It was seen in 84%, symmetrical and independent of sex, bodyweight, occupation and left- or right handedness. It is, therefore, not considered to be a sign of arthrosis.