Novel diagnostic and prognostic factors for the advanced melanoma based on the glycosylation-related changes studied by biophysical profiling methods

Melanoma is a life-threatening disease due to the early onset of metastasis and frequent resistance to the applied treatment. For now, no single histological, immunohistochemical or serological biomarker was able to provide a precise predictive value for the aggressive behavior in melanoma patients. Thus, the search for quantifying methods allowing a simultaneous diagnosis and prognosis of melanoma patients is highly desirable. By investigating specific molecular interactions with some biosensor-based techniques, one can determine novel prognostic factors for this tumor. In our previous study, we have shown the possibility of a qualitative in vitro distinguishing the commercially available melanoma cells at different progression stages based on the measurements of the lectin Concanavalin A interacting with surface glycans present on cells. Here, we present the results of the quantitative diagnostic and prognostic study of both commercial and patient-derived melanoma cells based on the evaluation of two novel factors: lectin affinity and glycan viscoelastic index obtained from the quartz crystal microbalance with dissipation monitoring (QCM-D) measurements. Two approaches to the QCM-D measurements were applied, the first uses the ability of melanoma cells to grow as a monolayer of cells on the sensor (cell-based sensors), and the second shortens the time of the analysis (suspension cell based-sensors). The results were confirmed by the complementary label-free (atomic force microscopy, AFM; and surface plasmon resonance, SPR) and labeling (lectin-ELISA; and microscale thermophoresis, MST) techniques. This new approach provides additional quantitative diagnosis and a personalized prognosis which can be done simultaneously to the traditional histopathological analysis.

[Novel therapies in the treatment of atopic dermatitis]

Atopic dermatitis is a chronic, inflammatory disease characterized by eczematous lesions in typical locations. It is caused by the complex interplay between genetic predisposition, environmental factors and altered skin barrier. A more precise understanding of the pathogenesis of atopic dermatitis revealed novel therapeutic options. Dupilumab, which long-term effectiveness and safety have been proven, is the first biologic available for atopic dermatitis. Other monoclonal antibodies such as nemolizumab, tralokinumab, lebrikizumab and fezakinumab demonstrated statistically significant clinical improvements in phase 2 and 3 trials. Further investigations are needed to evaluate their longterm efficacy. JAK inhibitors such as abrocitinib, baricitinib and upadacitinib showed promising effects in improvement of skin lesions and itch reduction. Beneficial immunomodulatory effect of JAK inhibitors dissipate relatively quickly with cessation of the drug, because as opposed to monoclonal antibodies, they have short half-lives. Thus, during SARS-CoV-2 infection it might be safer to use JAK inhibitors in case of necessity of a rapid immune response. There is a need to differentiate subtypes of atopic dermatitis, based on clinical symptoms and inflammatory mediators to choose an optimal therapeutic option for each patient.

A Novel and Effective Method for Human Primary Skin Melanocytes and Metastatic Melanoma Cell Isolation

Simple Summary

The present paper describes a simple, non-enzymatic and effective method of melanocyte or metastatic melanoma cell isolation from skin or lymph node explants, respectively. The method is based on selective harvesting of melanocytes or melanoma cells emigrating from the explants. Thus, isolated cells display specific phenotypical and functional features of melanocytes/melanoma cells such as tyrosinase and Melan-A expression and melanin production. Furthermore, melanocyte or melanoma cell cultures are not contaminated by keratinocytes and/or fibroblasts. The method appears to be a useful tool for studies on the biology of melanocytes and malignant melanoma.

Abstract

The development of an effective method of melanocyte isolation and culture is necessary for basic and clinical studies concerning skin diseases, including skin pigmentation disorders and melanoma. In this paper, we describe a novel, non-enzymatic and effective method of skin melanocyte and metastatic melanoma cell isolation and culture (along with the spontaneous spheroid creation) from skin or lymph node explants. The method is based on the selective harvesting of melanocytes and melanoma cells emigrating from the cultured explants. Thereby, isolated cells retain their natural phenotypical features, such as expression of tyrosinase and Melan-A as well as melanin production and are not contaminated by keratinocytes and fibroblasts. Such melanocyte and melanoma cell cultures may be very useful for medical and cosmetology studies, including studies of antitumor therapies.

Efficacy and Safety of Abrocitinib in Combination With Topical Therapy in Adolescents With Moderate-to-Severe Atopic Dermatitis: The JADE TEEN Randomized Clinical Trial

Question

What is the short-term efficacy and safety of oral abrocitinib in adolescents with moderate-to-severe atopic dermatitis?

Findings

In the randomized clinical trial JADE TEEN, a phase 3 study of abrocitinib in combination with topical therapy that included 285 adolescents with moderate-to-severe atopic dermatitis, significantly more adolescents who were treated with abrocitinib compared with placebo achieved an Investigator’s Global Assessment response or clear or almost clear, at least 75% improvement in Eczema Area and Severity Index response, and/or at least 4-point improvement in Peak Pruritus Numerical Rating Scale response. Serious adverse events were reported for fewer than 3% of patients.

Meaning

Oral abrocitinib in combination with topical therapy was effective and well-tolerated in adolescents with moderate-to-severe atopic dermatitis.

Importance

Dupilumab subcutaneous injection is approved for treating moderate-to-severe atopic dermatitis (AD) in adolescents, but there has been too little research on an efficacious systemic oral treatment with a favorable benefit-risk profile for adolescents with moderate-to-severe AD.

Objective

To investigate the efficacy and safety of oral abrocitinib plus topical therapy in adolescents with moderate-to-severe AD.

Design, Setting, and Participants

The phase 3, randomized, double-blind, placebo-controlled study JADE TEEN was conducted in countries of the Asia–Pacific region, Europe, and North America in patients aged 12 to 17 years with moderate-to-severe AD and an inadequate response to 4 consecutive weeks or longer of topical medication or a need for systemic therapy for AD. The study was conducted between February 18, 2019, and April 8, 2020. The data were analyzed after study completion.

Interventions

Patients were randomly assigned 1:1:1 to receive once-daily oral abrocitinib, 200 mg or 100 mg, or placebo for 12 weeks in combination with topical therapy.

Main Outcomes and Measures

Coprimary end points were achievement of an Investigator’s Global Assessment (IGA) response of clear (0) or almost clear (1) with improvement of 2 or more grades from baseline (IGA 0/1) and 75% or greater improvement from baseline in Eczema Area and Severity Index (EASI-75) response at week 12. Key secondary end points included 4-point or greater improvement in Peak Pruritus Numerical Rating Scale (PP-NRS4) at week 12. Adverse events (AEs) were monitored.

Results

This study included 285 adolescents with moderate-to-severe AD (145 boys [50.9%] and 140 girls [49.1%]), of whom 160 (56.1%) were White and 94 (33.0%) were Asian; the median age was 15 years (interquartile range 13-17 years). Substantially more patients treated with abrocitinib (200 mg or 100 mg) vs placebo achieved an IGA response of 0/1 (46.2%; 41.6% vs 24.5%; P < .05 for both), EASI-75 (72.0%; 68.5% vs 41.5%; P < .05 for both), and PP-NRS4 (55.4%; 52.6% vs 29.8%; P < .01 for 200 mg vs placebo) at week 12. Adverse events were reported for 59 (62.8%), 54 (56.8%), and 50 (52.1%) patients in the 200 mg, 100 mg, and placebo groups, respectively; nausea was more common with abrocitinib, 200 mg (17 [18.1%]) and 100 mg (7 [7.4%]). Herpes-related AEs were infrequent; 1 (1.1%), 0, and 2 (2.1%) patients had serious AEs.

Conclusions and Relevance

This randomized clinical trial found that oral abrocitinib combined with topical therapy was significantly more effective than placebo with topical therapy in adolescents with moderate-to-severe AD, with an acceptable safety profile.

Trial Registration

ClinicalTrials.gov identifier: NCT03796676

Single Dose of N-Acetylcysteine in Local Anesthesia Increases Expression of HIF1α, MAPK1, TGFβ1 and Growth Factors in Rat Wound Healing

In this study, we aimed to investigate the influence of N-acetylcysteine (NAC) on the gene expression profile, neoangiogenesis, neutrophils and macrophages in a rat model of incisional wounds. Before creating wounds on the backs of 24 Sprague-Dawley rats, intradermal injections were made. Lidocaine-epinephrin solutions were supplemented with 0.015%, 0.03% or 0.045% solutions of NAC, or nothing (control group). Scars were harvested on the 3rd, 7th, 14th and 60th day post-surgery. We performed immunohistochemical staining in order to visualize macrophages (anti-CD68), neutrophils (anti-MPO) and newly formed blood vessels (anti-CD31). Additionally, RT-qPCR was used to measure the relative expression of 88 genes involved in the wound healing process. On the 14th day, the number of cells stained with anti-CD68 and anti-CD31 antibodies was significantly larger in the tissues treated with 0.03% NAC compared with the control. Among the selected genes, 52 were upregulated and six were downregulated at different time points. Interestingly, NAC exerted a significant effect on the expression of 45 genes 60 days after its administration. In summation, a 0.03% NAC addition to the pre-incisional anesthetic solution improves neovasculature and increases the macrophages' concentration at the wound site on the 14th day, as well as altering the expression of numerous genes that are responsible for the regenerative processes.

[Diet in pathogenesis of acne vulgaris]

Acne vulgaris is one of the most common dermatologic condition especially among adolescents. Acne is related to excess sebum production by sebaceous glands, inflammation both within and adjacent to the comedones, hyperproliferation of Propionibacterium acnes. Some of investigations show association between acne and diet. Milk increases the level of IGF-1 leading to the synthesis of androgen-mediated increases sebum production. Chocolate predispose to hyperglycemia and insulinemia which aggravate of acne vulgaris. High levels of omega-6 fatty acids have been associated with increase of acne in contrast to omega-3 fatty acids, which decrease inflammation. Food have huge impact on development and severity of acne and may exert beneficial effect in the treatment of this disorder.

[Atopic dermatitis - risk factors and treatment]

Atopic dermatitis (AD) is a chronic, inflammatory skin disease characterized by severe itching and eczematic skin lesions. In Poland from 1.5 to 2.5 million people suffer from AD. The pathophysiologic complexity and the wide spectrum of clinical phenotypes cause diagnostic and therapeutic problems and this is the basis for the division of the disease into subtypes. Heterogeneity of the disease is also confirmed in the study of the genotype of the disease. In relation with AZS more than 1000 loci in chromosomes were demonstrated. The roles of certain genes and the pathophysiology of lesions caused by their polymorphism were described. Wide spectrums of AD risk factors are: cigarette smoking, alcohol consumption during pregnancy, obesity and high and low birth weight. The quality of life in patients with AD is impaired, the disease disrupts family and professional relationships. Biological medical products are an example of an individual approach to the treatment of AD. It seems, individual approach to disease and treatment can be a successive solution to the problem.

Anti-Interleukin-31 Receptor A Antibody for Atopic Dermatitis

BACKGROUND

Interleukin-31 may play a role in the pathobiologic mechanism of atopic dermatitis and pruritus. We wanted to assess the efficacy and safety of nemolizumab (CIM331), a humanized antibody against interleukin-31 receptor A, in the treatment of atopic dermatitis.

METHODS

In this phase 2, randomized, double-blind, placebo-controlled, 12-week trial, we assigned adults with moderate-to-severe atopic dermatitis that was inadequately controlled by topical treatments to receive subcutaneous nemolizumab (at a dose of 0.1 mg, 0.5 mg, or 2.0 mg per kilogram of body weight) or placebo every 4 weeks or an exploratory dose of 2.0 mg of nemolizumab per kilogram every 8 weeks. The primary end point was the percentage improvement from baseline in the score on the pruritus visual-analogue scale (on which a negative change indicates improvement) at week 12. Secondary end points included changes in the score on the Eczema Area and Severity Index (EASI, on which a negative change indicates improvement), and body-surface area of atopic dermatitis.

RESULTS

Of 264 patients who underwent randomization, 216 (82%) completed the study. At week 12, among the patients who received nemolizumab every 4 weeks, changes on the pruritus visual-analogue scale were -43.7% in the 0.1-mg group, -59.8% in the 0.5-mg group, and -63.1% in the 2.0-mg group, versus -20.9% in the placebo group (P<0.01 for all comparisons). Changes on the EASI were -23.0%, -42.3%, and -40.9%, respectively, in the nemolizumab groups, versus -26.6% in the placebo group. Respective changes in body-surface area affected by atopic dermatitis were -7.5%, -20.0%, and -19.4% with nemolizumab, versus -15.7% with placebo. Among the patients receiving nemolizumab every 4 weeks, treatment discontinuations occurred in 9 of 53 patients (17%) in the 0.1-mg group, in 9 of 54 (17%) in the 0.5-mg group, and in 7 of 52 (13%) in the 2.0-mg group, versus in 9 of 53 (17%) in the placebo group.

CONCLUSIONS

In this phase 2 trial, nemolizumab at all monthly doses significantly improved pruritus in patients with moderate-to-severe atopic dermatitis, which showed the efficacy of targeting interleukin-31 receptor A. The limited size and length of the trial preclude conclusions regarding adverse events. (Funded by Chugai Pharmaceutical; XCIMA ClinicalTrials.gov number, NCT01986933 .).

Osteocyte Lacunae Density in Dentine-Induced Ectopic Bone

The frequency of osteocytic lacunae, expressed as mean lacunae number per 1000 μm2 of measured bone, evaluated 65 days post intramuscular implantation of demineralized incisors is higher (1.10 ± 0.19) than in femoral (orthotopic) bone (0.91 ± 0.16). The surface of evaluated bones was measured by means of the "weight of bone picture". These results provide new data on the biology of ectopic bone.

Regulation of Bone Homeostasis by Osteocytes

New data concerning the function of osteocytes as the central regulators of bone homeostasis are briefly outlined. It is established that osteocytes are the main target cells for parathormone. They are a rich source of sclerostin, the main inhibitor of osteoblast activity, and of the RANKL cytokine, the most important regulator of osteoclastogenesis. Under shear stress causing microinjury, osteocytes enter programmed cell death (apoptosis) and osteocyte apoptosis is a signal for nearby healthy osteocytes to activate osteoclasts to resorb bone.

[Influence of exogenous and endogenous factors on the course of psoriasis]

Psoriasis is a chronic, inflammatory disease, which symptoms appear mainly within the skin. Genetic and environmental factors are known to play a key role in etiopathogenesis of psoriasis. Therapy directed against psoriasis includes the topical and the systemic treatment. The immunotherapy (biologicals) is known to be relatively less harmful, due to action strictly against proinflammatory molecules, responsible in part for the progression of psoriasis. Because of substantial role of environmental factors in the etiopathogenesis of psoriasis, it is possible to get a clinical improvement of psoriatic lesions by modification of patients dietary habits and their lifestyle. Reduction of the calorific value of meals, the bodyweight reduction, the diet rich in unsaturated fats and antioxidants, likewise, abstinence and the reduction of stress level in everyday life, are known to have a positive effect on the course of psoriasis. It is stated that psoriatic patients are suffering from many other diseases e.g. cardiovascular, respiratory and hormonal diseases, whose treatment might exacerbate psoriasis. Thus, patients with psoriasis following the appropriate recommendations can greatly reduce disease progression.

Incidence of bone formation by whole bone marrow cell suspensions and by its stromal cell cultures injected into kidney parenchyma of Balb/c mice

The evaluation of incidence of bone formation by whole syngeneic bone marrow cell suspension and by bone marrow stromal cell cultured in vitro injection into kidney parenchyma was done. Bone tissue was found in 26 kidneys out of 100 injected with whole bone marrow cells suspension. Cultured stromal bone marrow cells grafted into kidney parenchyma produced ossicles in only 4 out of 101 injected kidneys. Such low incidence of bone forming ability of the marrow stromal cell cultures grafted into kidney indicate their useless for study on bone histogenesis in the kidney by murine marrow stromal cell cultures.

[The importance of lactoferrin in bone regeneration]

Lactoferrin is an iron-binding protein secreted by mammary gland, thus present in milk and in colostrum, which are a cheap and easy to obtain sources of this protein. Lactoferrin is also present in specific granules of neutrophils. Lactoferrin is a multifunctional agent involved, among others in the immune response and in the regulation of bone metabolism. Lactoferrin actives of osteoblast proliferation and bone matrix secretion, and inhibits apoptosis of osteoblast and osteoclastogenesis. Lactoferrin administered to rodents accelerates bone healing and prevents bone loss induced by ovariectomy. Therefore the use of lactoferrin or milk whey in osteoporosis treatment and prevention is postulated.

The evaluation of the biomedical effectiveness of poly(amido)amine dendrimers generation 4.0 as a drug and as drug carriers: a systematic review and meta-analysis

The purpose of this study was to investigate the evaluation of the biomedical effectiveness of poly(amido)amine dendrimers generation 4.0 (PAMAM G4) as a drug and as drug carriers by a systematic review of literature and meta-analysis. The results obtained from meta-analysis concluded that drug therapy reduces the change of parameters in relation to the control. The impact of the drug administered to change the test parameters are dependent on the type of tissue. PAMAM G4 may be effective in vitro and in vivo as a drug and drug carriers and may have appropriate applications in various fields of medicine. PAMAM G4 dendrimers hold promises for nanomedicine.

Sclerostin, an osteocytes-derived bone-forming inhibitor

Sclerostin is a recently identified glycoprotein expressed and synthesized by osteocytes. It is a powerful inhibitor of osteoblasts proliferation and differentiation. Sclerostin inhibits the Wnt signaling, the main trigger of osteoblasts activity. Osteocytes on response to a mechanical loading decrease the synthesis of sclerostin enabling in osteoblasts the Wnt signaling and promote their bone-forming activity. This explains why mechanical loading induces bone formation. Monoclonal antibodies directed against sclerostin reverses sclerostin induced bone catabolic effect and are promising tool in prevention and treatment of osteoporosis in human.

[Collagen based dressings in the treatment of wound healing]

Collagen is the fundamental protein forming the connective tissues matrix, improves the ability of keratinocytes to migrate to sites that require rebuilding of the damaged epidermis, is one of the component of dressings used to accelerate wound healing. Because of the potential risk of the presence of pathogenic prions in bovine collagen, part of collagen dressings is formed on the basis of porcine collagen. Currently, a least of an immunogenic form of collagen is atelocollagen, which is subjected to enzyme-treated collagen, in which the terminal amino acids are removed from the collagen. It is assumed that in the near future atelocollagen will be used also as a carrier for drugs which support the healing processes.

Osteogenic efficiency of demineralized and lyophylized xenogeneic bone and syngeneic dentine implants in mice

Intramuscular implantation of demineralized and lyophilized rat bone matrix and murine lower incisors into thigh muscles of BALB/c mice results in deposits of bone adjacent to the implants, a phenomenon termed as ectopic osteogenesis. The yield of induced bone does not critically depend on the mass of implanted matrices, and thus on the quantity of bone morphogenetic proteins (BMPs) present in the implants. A positive correlation between bone matrix implant weight and the yield of induced bone was observed only 28 days post grafting, i.e. when endochondreal osteogenesis is completed and bone resorption has not advanced. A more consistent yield of bone induction wasobserved in the case of demineralized tooth implants. It is postulated that chondro/osteoinduction by demineralized, lyophilized matrix implants is not determined by the range of BMPs presumably released in proportion to implant size, but is rather limited by the population of responsive host mesenchymal cells.

Adipose mesenchymal stem cells. Their characteristics and potential application in tissue repair

Mesenchymal stem cells, derived from adipose tissue do not differ substantially from mesenchymal stem cells isolated from bone marrow stroma. They are able to differentiate in differentiating culture medium into various cell type of mesodermal lineage, but also into cells of ectodermal type. Their potency to differentiate toward osteogenic and adipogenic lineage is promising to be a ready source of cells for tissue regeneration.

The adipocyte component of bone marrow in heterotopic bone induced by demineralized incisor grafts

The relative proportion of adipocytes to hematopoietic elements in the marrow of heterotopically induced bone evaluated 4-42 weeks post implantation of demineralized murine incisors was estimated by histological analysis of hematoxylin-eosin stained tissue sections. Using computerized image analysis of microphotographs,the proportion of nuclear cells vs. adipocytes was ascertained. The percentage of adipocytes in marrow increases over time. Such an effect, the replacement of myelopoietic marrow by adipogenic (yellow) marrow and the resorption of induced bone, is observed in human osteoporosis. A decline in the non-adipogenic cell compartments of bone marrow accompanying induced bone begins in the fourth week of induction, gradually progresses until the 26th week, and does not change after that. The luminosity, a parameter used in image analysis and proportional to the number of nuclear cells, was 124 ± 3 in hematopoietic femoral bone marrow, and that of bone marrow of the induced bone was of a similar value (117 ± 8) in the fourth week. An evident decline in luminosity of bone marrow filling the foci of heterotopic bone was observed in samples taken at nine weeks (82 ± 20). This process progressed until the 26th week, reaching a luminosity of 70 ± 21. At the 42nd week, the luminosity remained at the same level (71 ± 27). This indicates that the replacement of hematopoietic bone marrow of heterotopically induced bone by unilocular adipocytes begins relatively early (the fourth week) and is persistent.

Favourable prognosis in medulloblastoma with extensive nodularity is associated with mitogen-activated protein kinase upregulation

Medulloblastoma with extensive nodularity (MBEN) is the only type of medulloblastoma (MB), an aggressive CNS tumour of childhood, that is connected with favourable prognosis. In patients with MBEN tumour resection and chemotherapy are sometimes sufficient. While development of other types of MB is usually connected with activation of the wingless pathway, sonic hedgehog pathway or mammalian target of rapamycin (mTor) pathway, little is known about the molecular basis of MBEN pathophysiology. In the present paper we evaluated activation of the mTor pathway and kinases upstream of mTor, mitogen-activated protein kinase (MAPK/Erk) and protein kinase B (PKB/Akt) in an MBEN sample. Using western blot technique with antibodies directed against active, phosphorylated forms of proteins, we found upregulation of mTor, Akt and Erk. Thus we postulate that the mTor pathway, often implicated in the development of CNS tumours, is also responsible for MBEN progression. Especially interesting seems implication of Erk and other kinases belonging to the same pathway: mitogen-activated protein kinase kinase (MEK-1) or phospho-ribosomal S6 kinase-1 (p90 RSK1), whose activity we usually demonstrate in more benign neoplasms. However, it remains to be clarified whether Erk pathway activation is actually prognostic for benign tumour development.

Effects of time of initial exposure to MSV sarcoma on bone induction by dentine matrix implants and on orthotopic femora

HCl-demineralized murine lower incisors were implanted intramuscularly into syngeneic BALB/c mice to induce heterotopic osteogenesis. Implants were exposed at the early, preosteogenic stage (4), or at the later, osteogenic stage (12) to the Moloney sarcoma virus (MSV), which within 3–4 days results in a sarcoma. The yield of bone induction was determined by weight of dry bone mass following NaOH hydrolysis of soft tissues. To verify the effect of this sarcoma on orthotopic local femoral bone, the dry mass of the tumor-exposed femora was measured and compared with the weight of MSV-unexposed contralateral controls. MSV-sarcoma or cells involved with their spontaneous rejection have a stimulatory effect on the periosteal membrane of the tumor-adjacent femoral bones, increasing their dry mass on average by 18%. No stimulatory effect on heterotopic bone induction was observed when the MSV sarcoma grew during the early, preosteogenic stage (4 onward), but when the tooth matrix had been exposed to such tumor at the already bone-forming stage, (12 onward), the yield of bone induction was enhanced. Thus, it is postulated that lesions induced by MSV during the early, preosteogenic stage inhibit recruitment of osteoprogenitor cells or degrade Bone Morphogenetic Proteins (BMPs) released by matrix resorbing inflammatory cells, whereas when acting on already existing bone they have a stimulatory effect.

Activation of Akt/mTOR pathway in a patient with atypical teratoid/rhabdoid tumor

A typical teratoid/rhabdoid tumor (AT/RT) is a highly malignant childhood brain tumor. Most AT/RTs are shown to contain chromosome 22 mutation in the region of hSNF5/INI1 gene, whose protein product participates in chromatin remodeling. Although the presence of this mutation is well described, molecular pathways underlying AT/RT development are poorly, if at all, understood. In the current paper we evaluate a case of AT/RT with special consideration of two pathways often implicated in tumor development: protein kinase B (PKB or Akt) and extracellular signal-regulated kinase (Erk). First, we confirmed expression of typical protein pattern being unique for AT/RT, including epithelial membrane antigen, S-100 and glial fibrillary acidic protein. In molecular analyses we tested the sample for activity of Akt and Erk kinase cascade. We found that Erk pathway signaling in the tumor was not upregulated. Neither c-Raf, MAPK nor Erk were hyperphosphorylated. On the other hand, we detected significant phosphorylation of Akt, phosphoinositide-dependent kinase-1 (PDK1) and glycogen synthase kinase 3 (GSK-3). At the same time, inhibitor of Akt pathway, phosphatase and tensin homolog (PTEN), was not upregulated. These results strongly support the hypothesis that Akt pathway contributes to chromatin remodeling disruption, promoting malignant transformation of AT/RT.

Heterotopic osteogenesis by murine demineralized incisors at lesions sites induced by concanavalin a in mice

The aim of this study was to examine the effects of Concanavalin A (Con A) administration on the early (preosteogenic) and late stages of osteogenesis induced by implantation of demineralized murine incisors into syngeneic mice. Local administration of Con A resulted in an increased yield of demineralized incisor-induced bone when injected during the preosteogenic stage of induction. This effect was not observed when Con A was injected after heterotopic osteogenesis had been established. This suggests that Con A recruits osteoprogenitor cells, but does not stimulate differentiated chondroblasts and osteoblasts.

[Factors affecting melanogenesis and methods used for identification of pigmentation disorders]

Melanins are pigments widely distributed in living organisms. In humans melanin is synthetised in the retina, choroid and epidermis. Melanins fulfil a protective function and are responsible for the color of eyes, skin and hair. Melanogenesis is a process undergoing in specialized organelles of melanocytes--melanosomes. After synthesis, melanin is transported to target cells--keratinocytes. The key enzyme of the melanin synthesis pathway is tyrosinase. Many agents used in the treatment of hyperpigmentation act as tyrosinase inhibitors. Depigmenting agents and those increasing melanin synthesis are used in medicine and cosmetology. Also natural plant melanins extracted from e.g. Nigella sativa, have interesting effects on mammalian cells. In the current review paper we present methods used for identification of melanin and melanocytes in diagnostics of disorders affecting melanogenesis process.

[Statins and their pleiotropic effects]

Statins are well-established and effective drugs in the treatment of hyperlipidemias and coronary heart disease. However the effects of statins extend beyond their lipid-lowering actions, due to their capacity to inhibit prenylation of some intracellular regulatory proteins. Recent studies have shown that statins could modulate inflammantory response, improve endothelial function, exert antiarrhytmic properties, have beneficial effects on renal function and bone tissue. Statins may exert effect in the treament and prevention of dementia and some autoimmune disorders. Although statins therapy is generally well-tolerated, sometimes they lead to objective adverse effects, mainly in muscular system. Combination therapy with fibrates, coenzyme Q and other substances may increase and even extend therapeutic effects of statins. Further studies will help to clarify the clinical role of statins.

Bioactive composites for bone regeneration. Review

Beside auto- and allogeneic bone chips used for filling bone lesions or to enhance of bone regeneration, various types of ceramics, natural and synthetized bone mineral hydroxyapatite and tricalcium phosphate, as well as numerous polymers and co-polymers of alfa-hydroxy acids are widely used. These materials in a pure form demonstrate good osteoconductivity, but very rarely are osteoinductive. However, deposition of osteogenic cells on their surface, most frequently derived from bone marrow stroma enables such "constructs" or "composites" to maintain osteogenic differentiation, both in vitro, where expression of several types of osteogenic markers, such as alkaline phosphatase expression, collagen type I synthesis, osteocalcin expression, mineralization is detected, and in vivo, where they form sites of histogenesis of bone and later of bone marrow.

[Cytokeratin detection as a diagnostic tool in oncology]

A large part of the cell cytoplasm of the cells consists of components forming cytoskeleton. The cytoskeleton is represented by actin-containing microfilaments, tubulin-containing microtubules and filaments of intermediate size. The last ones have diameters between 7-11 nm. Based on morphological, immunological and biochemical criteria the filaments of intermediate size are divided into: a) nuclear lamins; b) neurofilaments which are typical for neuronal cells; c) vimentin and vimentin-like filaments present especially in mesenchyma derived cells and d) filaments containing keratin-like proteins--cytokeratins. Cytokeratin filaments are a family of many different polypeptides and are normal components of epithelial cell cytoskeleton. Cytokeratins are expressed in various types of epithelia in different combinations. This is why antibodies against various cytokeratins have been used to characterize a wide variety of epithelial tumors. For example immunohistochemical detection of cytokeratin can identify micrometastases, not detected by conventional hematoxylin and eosin staining. Also serum cytokeratins levels are widely used as the markers of tumors of epithelial origin. In this review clinical applications of cytokeratins detection are presented.

[Photoaging of a skin]

Photoaging is a skin aging caused by long-term exposure to the ultraviolet radiations of the sun. Ultraviolet activates activating protein-1 and generate reactive oxygen species which play a substantial role in collagen degradation. Clinically, photoaged skin appears as a coarse with deep wrinkles. Presently there are available several agents to reverse the photodamage. There is conclusive evidence that synthetic vitamin A derivatives are the most effective in the treatment of photoaging. Erythema and scaling may be experienced initially.

Senescence of osteogenic cells. Review

In older individuals the regeneration of bone tissue is delayed due to the diminished activity of osteoblasts, while osteogenic potency of human bone marrow stromal cells, also capable of forming bone, does not change with age. The number of osteoprogenitor cells is not reduced in ageing subjects, but their proliferating rate and the activity of their derivatives--osteoblasts, is markedly diminished, since the self-renewing potential of these cells is hindered. The senescence of osteoblasts in ageing people is also accelerated. Changes within the bone marrow microenvironment reduce osteogenic potential of osteoprogenitor cells leading to impaired bone formation seen in senility, while the potency for ectopic osteogenesis does not change with age. This review summarizes documented mechanisms of changes in osteogenic activity of cells in elderly.

Osteogenic potential of bone marrow stromal cells

Bone marrow is the point of origin of several cell types, including stromal cells. Adherent bone marrow stromal cells can differentiate into chondrocytes, adipocytes and osteoblasts. Several substances which modulate the dynamics and differentiation of bone marrow stromal cells have been identified. Recently it has been discovered that those bone marrow cells which are non-adherent in tissue culture for 3 days have osteogenic potential comparable to that of whole bone marrow cells. In the future, implantation of non-adherent bone marrow stromal cells may be of use as an aid in bone fracture healing, similar to whole marrow or adherent stromal cell grafting at present.

[Clinical applications of hyaluronic acid]

Hyaluronic acid (HA) is a glycosaminoglycan composed of alternating N-acetyl-D-glucosamine and D-glucuronic acid moieties. HA is an ubiquitous component of connective tissue where it forms matrix and plays an important role in the maintenance of matrix structure and water balance. The viscoelastic properties of HA derivatives and nonimmunogenicity has provided its use in a number of pharmaceutical applications. Ability of HA to create and fill space by organizing and modifying the extracellular matrix is widely used for soft tissue augmentation to limit age-related and photoinduced skin aging, but also may be used for correction of facial lipodystrophy and to prevent reccurence of hypertrophic scars or keloids. Furthermore HA may be employed as a surgical aid in ophthalmology or to reduce knee pain and joint motion in patients with osteoarthritis. In children HA may become an alternative to the open surgery for the management of vesicoureteral reflux.

Influence of fluvastatin on bone formation induced by demineralized bone matrix in mice

In the last decade, statins became widely used drugs in hypercholesterolemia treatment. Several studies have demonstrated that statins may also be successfully administered in the treatment of osteoporosis. There are, however, no reports regarding the effect of statins on heterotopic ossification (HO). In this paper, we examined the influence of fluvastatin on heterotopically induced bone formation in mice. HO was induced by implantation of rat-derived demineralized bone matrix (DBM) into intramuscular pockets in CFW mice. Mice in the experimental groups received fluvastatin at 3.6 mg/kg per day for 25 consecutive days whilst mice in the control group received placebo. Twenty five days after DBM implantation blood samples were collected to measure total serum cholesterol (TC), triglycerides (TG), low density lipoprotein cholesterol (LDL-C) and alkaline phosphatase (AP) activity. Mass of mineral deposited in the induced ossicle was established after hydrolysis of soft tissues surrounding the induced ossicles. In fluvastatin-treated mice, the mass of mineral deposited in heterotopically induced ossicles and AP serum concentration were significantly increased while TG and TC concentrations were decreased, when compared to mice receiving placebo. These results show that administration of statins, in some instances, may affect heterotopic ossification and that during hypocholesterolemic treatment of patients with predisposition to HO, following hip arthroplasty, such treatment may increase risk of HO.

FLUVASTATIN INCREASES HETEROTOPICALLY INDUCED OSSICLES IN MICE

1. The aim of the present study was to evaluate the influence of fluvastatin (3-hydroxy-3-methylglutarylcoenzyme A reductase inhibitor) on heterotopic ossification (HO) induced by HeLa cells. 2. C57Bl/6 mice were injected with 3 x 10(6) HeLa cells into right thigh muscles. Mice in the experimental group received fluvastatin 1.2 mg/kg per day for 17 consecutive days, while mice in the control group received placebo. Intact mice served as an additional control. Seventeen days post-HeLa cell grafting, blood samples were collected to measure total serum cholesterol (TC), triglycerides (TG), low density lipoprotein cholesterol and alkaline phosphatase (AP). 3. In all animals injected with HeLa cells, the mass of mineral deposited in the induced ossicle was established after hydrolysis of soft tissues surrounding the induced ossicles. In fluvastatin-treated mice, the mass of mineral deposited in heterotopically induced ossicles was significantly increased, when compared to mice receiving placebo. This was followed by a significant decrease of TG concentration; whereas the levels of serum AP were not significantly affected. 4. These results indicate that administration of statins may affect heterotopic ossification. This may also have clinical implication, because patients predisposed to HO and receiving statins during hypocholesterolemic treatment, may be at even greater risk of HO.

[Transdifferentiation of chondrocytes into osteogenic cells]

Hypertrophic chondrocytes, commonly considered as terminal cells designated to apoptotic elimination in the model of endochondral osteogenesis, are accordingly to the new concept based on histochemical, immunohistochemical, biochemical and cytological analysis, able to switch their metabolism and enter the osteoblastic differentiation path. According to this concept, some osteocytes in model of endochondral osteogenesis are derivative of hypertrophic chondrocytes. Also non-hypertrophic chondrocytes are able to transdifferentiate toward osteogenic cells, and the bone formed by such mechanism is termed "transchondroid bone".

Fluvastatin does not elevate periosteal osteogenesis induce by Moloney sarcoma virus (MSV) in mice

Several studies have demonstrated the pleiotropic effects of statins. Since Wang and associates reported that in rabbits lovastatin reduced steroid-induced bone loss, numerous authors have confirmed these data, however, others have reported conflicting results. In this study, the effects of fluvastatin on bone formation were investigated in early and late phase of osteogenesis. In the first set of experiments (early phase of osteogenesis) CFW/Ll mice were randomly divided into three groups. Two groups were injected with Moloney-murine sarcoma virus (Mo-MSV) into right thighs to induce orthotopic bone formation. Mice in the experimental group received fluvastatin for 11 consecutive days. Thirty days after Mo-MSV inoculation, total serum cholesterol, triglycerides, high- and low-density lipoprotein cholesterol, alkaline phosphatase (AP) were measured and bone mineral increase was calculated. In the second set of experiments (late phase of osteogenesis), fluvastatin was administered from day 11 after Mo-MSV inoculation for 20 consecutive days. Fluvastatin administration in the early phase of osteogenesis made no significant difference in average bone increase compared with mice receiving placebo. Lipid profile and AP were not significantly affected. During late phase of osteogenesis, the average increase in femural dry mass was significantly lower in the group of mice receiving fluvastatin than in the control group. Also, Mo-MSV-initiated tumors disappeared earlier in mice treated with fluvastatin. This may be attributed to the antioncogenic potential of fluvastatin. These results also point out that orthotopic bone formation at the sites of Mo-MSV inoculation in mice seems to be a useful model to examine the pleiotropic effects of statins.

Histological aspects of bone fracture healing

Bone fracture healing is a multistep phenomenon leading to full restoration of the damaged tissue. It replicates the events that happen during endochondral bone formation in prenatal life. The mechanisms which control bone fracture healing are basically the same as those regulating bone formation in the embryo. For bone fracture healing the first phase is the most important, i.e. blood clot formation, followed by the inflammatory reaction. During this phase the platelet-derived growth factors (PDGF), released from the blood clot and from the inflammatory cells, recruit and activate mesenchymal cells to differentiate into cartilage-forming cells. The hyaline cartilage thus formed is the scaffolding for endochondral osteogenesis. Periosteal cells also participate in hyaline cartilage formation. Endochondrally-formed bone (primary bone) is woven bone and has poor mechanical properties. It is replaced by lamellar bone by the process of 'bone modelling'. Primary bone trabeculae are resorbed by osteoclasts whilst mesenchymal-derived osteoblasts synthetise osteoid for bone lamellae (secondary bone). The stromal cells of bone marrow are an additional source of bone forming cells capable of differentiating into osteoblasts. The application of non steroid anti- inflammatory drugs (NSAID) impairs the early inflammatory phase and delayes bone fracture healing, by inhibiting the formation of prostaglandins - one of many factors which activate both osteoblasts and osteoclasts.

New factors affecting bone remodeling

Over the past few years the discovery of the mechanisms of osteoclast and osteoblast signaling and the relationship between bone resorption and osteogenesis has resulted in increasing our understanding of the process of bone remodeling. Recently new elements have been shown to be involved in the bone remodeling process. Leptin, produced by adipose tissue, regulates body mass by acting on the hypothalamic nuclei, and may modulate bone remodeling as well; sclerostin, responsible for the suppresion of bone formation. The gene encoding low-density lipoprotein receptor-related protein 5 is thought to regulate bone resorption. These molecules may become important tools in the development of therapeutic strategies for osteoporosis.

Non-adherent bone marrow cells are a rich source of cells forming bone in vivo

Syngeneic, allogeneic and xenogeneic (rat) freshly isolated bone marow cells + stromal cell cultures maintained in vitro for 10-30 days, as well as non-adherent cells removed from these cultures on 3rd-4th day were injected into the kidney parenchyma of mice, immunosuppressed with hydrocortisone. In syngeneic grafts the immunosuppression was omitted. In all transplant systems bone tissue was formed inside the kidney with 20% to 32% variation. Bone produced by allogeneic and xenogeneic cells is subject to rejection when immunosuppression ceases, as the bone formed is of donor origin. The "floating" cells, regardless of the transplant system, normally discarded during media replacement, turned out to be efficient bone producers. This notion is of practical implication when bone marrow cells are used for bone healing.

The histophysiology of fracture healing

The authors present, in somewhat simplified form, a synthetic collection of information pertaining to fracture healing form the histological perspective. The mechanisms of fracture healing are described in reference to the histological construction of bone, phases in the healing process, the reactions taking place at the fracture site, and the mechanisms for regulating these processes with growth and discrimination factors.

Local hypertrophic/hyperplastic changes of keratinizing squamous epithelium of pinna induced by concanavalin A and other immunomodulators in mice

Intradermal administration of concanavalin A, a potent T-cell mitogen, into an ear lap resulted in activation of chondrogenesis and stimulation of epidermis proliferation. This proliferation is sometimes invasive in character (pearls and epidermal nests form in the underlying connective tissue) but never turns into true cancerous lesions. This reaction can be delayed, but not prevented, by the prostaglandin inhibitor indomethacin. Stimulation of epidermis proliferation was also caused by administration of other immunomodulators, such as carrageenan type IV, Moloney sarcoma development, and rarely in the course of GvHr, but to much lesser degree than with concanavalin A. It is suggested that the same growth factors, which are mediators of local chondrocyte stimulation, are also mediators of keratinocyte activation.