Enhanced Pain Relief and Function Improvement in Children with Osgood-Schlatter Disease: Leukocyte-Rich Platelet-Rich Plasma (LR-PRP) as a Complementary Treatment to Standard Conservative Therapy.

BACKGROUND Osgood-Schlatter disease (OSD) causes pain and loss of function of the knee in growing children. This study aimed to evaluate pain and function of the knee joint in 152 growing children with chronic OSD before and after treatment with LR-PRP when used with standard conservative treatment. MATERIAL AND METHODS Treatment efficacy was evaluated using the VAS, Tegner, Lyshom, and KOOS scales. Patient satisfaction, post-surgery athletic performance, and X-ray assessment were also used to determine the success of the procedure. RESULTS We found that 75% of the subjects were satisfied with the results of the treatment, and 72% of the subjects returned to full physical activity. The analysis showed a significant decrease in the median VAS score after treatment compared to the pre-treatment score (P<0.05), and an increase in the median scores of the Tegner, Lysholm, and KOOS scales compared to the pre-treatment score (P<0.05; P<0.05; P<0.05, respectively). The results showed that the shorter the duration of the disease, the better the treatment results were received. Return to activity and patient satisfaction were highest in the study group previously rehabilitated. CONCLUSIONS LR-PRP injection of the tibial tuberosity in patients with chronic OSD with open growth cartilage is an effective and uncomplicated method. We did not observe any adverse effects, which suggests the relatively high safety of the procedure. The use of PRP in the earlier phase of the disease and additional rehabilitation before treatment significantly increases the effectiveness of treatment.

Importance of Metalloproteinase Enzyme Group in Selected Skeletal System Diseases.

Bone tissue is a dynamic structure that is involved in maintaining the homeostasis of the body due to its multidirectional functions, such as its protective, endocrine, or immunological role. Specialized cells and the extracellular matrix (ECM) are responsible for the remodeling of specific bone structures, which alters the biomechanical properties of the tissue. Imbalances in bone-forming elements lead to the formation and progression of bone diseases. The most important family of enzymes responsible for bone ECM remodeling are matrix metalloproteinases (MMPs)-enzymes physiologically present in the body's tissues and cells. The activity of MMPs is maintained in a state of balance; disruption of their activity is associated with the progression of many groups of diseases, including those of the skeletal system. This review summarizes the current understanding of the role of MMPs in bone physiology and the pathophysiology of bone tissue and describes their role in specific skeletal disorders. Additionally, this work collects data on the potential of MMPs as bio-markers for specific skeletal diseases.

Platelet-Rich Plasma Promotes the Proliferation of Human Keratinocytes via a Progression of the Cell Cycle. A Role of Prolidase.

Although the role of platelet-rich plasma (PRP) in tissue regeneration has been confirmed in many studies, the mechanism of this process is still not fully understood. Human keratinocytes (HaCaT) cells were used as an experimental model for studies on the effects of PRP on cell proliferation, migration, collagen biosynthesis, prolidase activity, and its expression and anabolic signaling. The activation of epidermal growth factor receptor (EGFR), ß1-integrin, and insulin-like growth factor-1 receptor (IGF-1R) by PRP were investigated by western blot and immunocytochemistry. It has been found that PRP induced keratinocytes migration and proliferation through activation of cell cycle progression and EGFR downstream signaling. Similar biological effects were achieved by an addition to the culture medium of prolidase (PEPD), a ligand of EGFR (PRP is a rich source of PEPD-2 ng/mL). PRP-dependent stimulation of collagen biosynthesis was accompanied by an increase in the expression of NF-κß, IGF-1R-downstream signaling proteins, and PEPD activity. The data suggest that PRP activates a complex of growth factors and adhesion receptors that stimulate cell proliferation, migration, and collagen biosynthesis. PRP induces PEPD-dependent human keratinocyte proliferation through activation of the EGFR receptor. Our study provides a novel mechanism of PRP-dependent wound healing.

Verapamil and collagenase differentially affect collagen metabolism in experimental model of Peyronie's disease.

OBJECTIVES: Peyronie's disease (PD) is accompanied by remodelling of connective tissue into fibrotic plaque. Treatment of the inflammatory and fibrotic phases of the disease is not established. The aim of the study was to evaluate the effect of verapamil (VER) and bacterial collagenase (COLL) on collagen metabolism and cell migration in fibroblasts with experimental wound healing and inflammation as an in vitro model of PD. MATERIALS AND METHODS: In vitro model of PD was designed using experimental model of inflammation induced by Interleukin-1 (IL-1) in cultured fibroblasts and mechanical damage of the cells. Cell viability, cell proliferation, collagen biosynthesis, prolidase activity and cell migration were studied in both models of the cells treated with VER and COLL. RESULTS: VER decreased cell viability, DNA and collagen biosynthesis and increased prolidase activity in control fibroblast, while in "wounded" fibroblasts it significantly decreased all the processes. COLL did not affect cell viability and DNA biosynthesis, while inhibited collagen biosynthesis and prolidase activity in both control and "wounded" fibroblasts. In IL-1-treated fibroblasts VER inhibited all studied processes except prolidase activity, while COLL inhibited only collagen biosynthesis and prolidase activity. COLL accelerated cell migration, while VER attenuated the process in fibroblast model of wound healing, compared to control cells. CONCLUSION: VER and COLL attenuate collagen biosynthesis in both fibroblast models. The VER-dependent inhibition of collagen biosynthesis was accompanied by inhibition of DNA biosynthesis at high prolidase activity, while COLL affected this process through inhibition of prolidase activity at high rate of DNA biosynthesis. It shows that anti-fibrotic activity of VER/COLL and anti-inflammatory activity of VER may represent approach to establish standard treatment of PD.

Rural-urban differences in children's musculosceletal injuries in north-eastern Poland

OBJECTIVE: To investigate rural-urban differences in severity of injuries, by means of age, sex and duration of hospitalization of injured children in northeastern Poland. METHODS: The study included children admitted to the Department of Pediatric Orthopaedics and Traumatology in between 2002-2005 (1322 patients) and 2012-2013 (1725 patients) due to injury. We applied the rural-urban division on the base of number of inhabitants (rural ­ below, urban ­ over 25000). We divided injuries into four categories based on severity. Statistical analysis was performed to compare the risk of hospitalization due to different types of injuries among children in different age and sex groups, living in rural and urban areas RESULTS: Children from urban areas have a higher risk of hospitalization compared to their peers living in rural areas due to two least severe categories of injuries. Children from rural areas had much higher risk of hospitalization due to most severe injuries. Results were consistent for both time intervals.. The average duration of hospitalization was significantly longer among rural populations. However, in both rural and urban areas the mean length of stay has been shortened in comparison with the years 2002-2005. The average age of urban patients has been reduced over the years and remained stable among rural population. In both groups boys comprised the majority of patients with all kinds of injuries. CONCLUSIONS: Analysis of the risk of hospitalization among children from rural and urban areas brings constructive conclusions only after applying the division based on severity of injuries. Children living in rural areas and small towns are at a higher risk of suffering severe injuries that pose a risk of permanent disability, and of longer hospitalization because of them, compared to children living in larger cities.

Lyme disease with effusion either in hip or knee in children from Podlaskie region treated in clinic in 2004-2010.

OBJECTIVES: Lyme disease (LB) relatively commonly causes arthritis among patients, especially in LB endemic area. The aim of the study was to analyze the prevalence of LB in children with hip and knee effusion in the North Eastern region of Poland. Conclusions from our study should justify the need of taking into account LB in the diagnosis of hip or knee effusion in children. MATERIALS AND METHODS: The medical records of 321 children, aged 2-18 years, with synovitis of the hip or knee were reviewed. RESULTS: In 273 cases with hip effusion: 32 (11.72%) patients were diagnosed with LB, 233 (85.74%) with transient arthritis, 6 (2.19%) with purulent arthritis, and 2 (0.73%) with juvenile idiopathic arthritis. In 48 cases with knee effusion: 12 (25%) patients were diagnosed with Lyme arthritis, 24 (50%) with transient arthritis, 5 (10.42%) with reactive arthritis, 4 (8.33%) with juvenile idiopathic arthritis, and 3 (6.25%) with purulent arthritis. CONCLUSIONS: The high prevalence of LB in children with hip or knee effusion in endemic areas suggests the need of diagnostics also for LB in all patients presenting with acute monoarticular arthritis. Antibiotic treatment results in complete recovery.

[Congenital insensitivity to pain]. / Wrodzona niewrazliwosc na ból.

Congenital insensitivity to pain belongs to rare diseases called hereditary sensory neuropathy (HSN). The disturbance of sense and secondary harms are creating clinical picture. The aim of this report was to describe therapeutic problems with which we met with a three siblings with congenital insensitivity to pain. The authors have described three children with congenital insensitivity to pain. The disease was diagnosed at the age of 3-5. These children painlessly have broken their lower limbs. These fractures were late diagnosed what resulted in a badly healed deformation of legs. For this reason, the right knee of the oldest boy had to be stiffened. This boy had also late diagnosed the left hip luxation, and hematomas had arisen, which become filled with pus. The boy was in sepsis and a dramatic life-and-death struggle was performed. A purulent focuses were removed from abdomen and femoral head was also resected. The other two siblings had fractures and infections, but not such severe as the oldest boy. It is well known that a causal treatment of this disease in unknown. Patients must learn to avoid mechanical and thermal trauma. It is the only way to prevent complications of this disease.

Plasma Levels of Metalloproteinase 3 (MMP-3) and Metalloproteinase 7 (MMP-7) as New Candidates for Tumor Biomarkers in Diagnostic of Breast Cancer Patients.

Matrix metalloproteinases (MMPs) are a group of enzymes that mediate both physiological and pathological processes such as carcinogenesis. The role of matrix metalloproteinase-3 (MMP-3) and (MMP-7) in the pathogenesis of breast cancer (BC) has been demonstrated, suggesting that they may be considered as potential markers of this condition. The aim of this study was to assess plasma concentrations and diagnostic utility of MMP-3 and MMP-7 in 100 patients with early-stage breast cancer with Luminal A subtype or Luminal B HER-negative subtype, before and after surgical treatment, and in the following control groups: patients with a benign tumor (fibroadenoma) and healthy subjects. The concentrations of MMP-3 and MMP-7 were referenced to the levels of the widely recognized marker for BC diagnosis CA 15-3. MMP-3 and MMP-7 was measured by ELISA method and CA 15-3 by CMIA. Plasma levels of MMP-7 were significantly higher in Luminal A and Luminal B HER2-negative subtype breast cancer patients as compared to the healthy group. MMP-7 demonstrated comparable but mostly higher to CA 15-3 or MMP-3 values of diagnostic sensitivity, specificity, positive and negative predictive values and AUC (0.6888 for Luminal A subtype; 0.7612 for Luminal B HER2-negative; 0.7250 for BC total group, respectively) in the groups tested. The combined use of the tested parameters resulted in a further increase in diagnostic criteria and AUC. These results suggest the usefulness of combining MMP-7 with CA 15-3 in the diagnostics of breast cancer, especially in Luminal B HER2-negative subtypes patients, as a new candidate for tumor markers.

Mu-Opioid Receptor 1 and C-Reactive Protein Single Nucleotide Polymorphisms as Biomarkers of Pain Intensity and Opioid Consumption.

Children constitute a special group in pain therapy. Single nucleotide polymorphisms that are associated with differences in postoperative, inflammatory pain perception and opioid requirement are the A118G SNP in the mu-opioid receptor 1 (OPRM1) gene and the rs1205 CRP. This study aimed to determine connection between OPRM1 and rs1205 CRP SNPs in pediatric patients postoperatively and pain intensity, the opioid dose needed to control pain after scoliosis correction, and other clinical aspects. Genotypes of rs1205 CRP and OPRM1 polymorphisms in a sample of 31 patients were specified, and statistical analysis was performed in terms of age, genotype frequency, pain assessment, sufentanil flow, post-anesthesia care unit stay, and the use of coanalgesics. The frequency of A/A and A/G genotypes in the OPRM1 gene was in line with 1000Genomes data for the European population. Patients from the AG group of OPRM1 SNP more frequently required coanalgesics for adequate pain control; however, it was of weak statistical significance. Other parameters measured in the study were not statistically significant in relation to OPRM1 and CRP polymorphisms. The effect of SNPs on postoperative pain management and opioid therapy in children was not confirmed by this study. An expansion of the study sample and other opioid-related SNPs is required.

Migration of Subtalar Implants in Paediatric Flatfoot Correction: A Pilot Study in Synthetic Bone Models.

BACKGROUND: Subtalar implant migration as a complication following subtalar arthroeresis has been described in the scientific literature. However, clinical studies do not allow for unequivocally determining the underlying causes. The aim of the study is to determine the risk of migration of two geometric types of subtalar implants. Biomechanical tests were carried out on a synthetic bone model with a soft tissue substitute, which allowed for reduction of variability of results caused by biological differences. MATERIAL AND METHODS: A foot model mirroring natural anatomy was made from synthetic bone and a silicone soft tissue substitute with the same hardness as that of the soft tissues of the foot. Two types of 11 mm Ti6Al4V titanium alloy implants were studied, namely, a rectangular subtalar screw and a cylindrical subtalar screw, a type commonly used in flatfoot reconstruction surgery in children. The screws were placed in the sinus tarsi and subjected to cyclic loading (up to 1,000,000 cycles at a frequency of 5 Hz, with a maximum load of 500 N). Comparative pull-out force tests were performed immediately following implantation and after the dynamic loading test. Wyniki. Following the dynamic loading test, all 12 samples were qualified for the pull-out force test. Cylindrical screws demonstrated higher pull-out force values both for the samples tested immediately following implantation and for those that underwent dynamic loading. Implants of the same shape did not show statistically significant differences in the Mann-Whitney U test (p >0.05). Wniosek. The synthetic research model produces reproducible results in the assessment of risk of implant migration. Long-term loading does not significantly affect the risk of implant migration.

Glycoconjugate markers of joint diseases.

A number of different types of glycoconjugate are found associated with joint tissue and fluids, comprising glycoproteins, glycolipids and glycosaminoglycans. Oligosaccharide chains of glycoconjugates are degraded by exoglycosidases, and the dominant exoglycosidase found in human blood, synovial fluid, the synovial membrane and chondrocytes of articular cartilage is HEX (N-acetyl-ß-hexosaminidase). HEX is localized mostly intracellularly in synovial cells. Serum activity of HEX may be used to monitor the course and efficiency of treatment of Lyme arthritis, and activity of HEX, above 10 µkat/kg of protein in the synovial fluid, suggests rheumatoid disease. There is a shortage of HEX inhibitors able to penetrate synoviocytes, so the development of drugs which inhibit synthesis and/or the activity of HEX will be a promising field for future investigations.

The Concentration of Selected Inflammatory Cytokines (IL-6, IL-8, CXCL5, IL-33) and Damage-Associated Molecular Patterns (HMGB-1, HSP-70) Released in an Early Response to Distal Forearm Fracture and the Performed Closed Reduction With Kirschner Wire Fixation in Children.

The evaluation of trauma after surgery through objective analysis of biochemical markers can help in selecting the most appropriate therapy. Thus the aim of the study was the evaluation of the concentration of selected inflammatory cytokines (IL-6, IL-8, CXCL5, IL-33), C-reactive protein (CRP), and damaged-associated molecular patterns (DAMPs): HMGB-1, HSP-70 in the plasma of children in response to bone fracture and 12-14 hours after subsequent surgery performed by closed reduction with percutaneous Kirschner wire fixation (CRKF). The study will answer the question if the CRFK procedure leads to excessive production of inflammatory and damage markers. Blood samples from 29 children with distal forearm fractures were collected 30 min. before CRKF procedure and 12-14 hours after performance of the procedure. The control group was composed of 17 healthy children. IL-6 and CRP concentrations were analyzed using routinely performed in vitro diagnostics tests; the remaining proteins were analyzed with the use of the ELISA method. Increased values of IL-6, CRP, and HSP-70 represented an early inflammatory response to distal forearm fractures classified as SH-II type according to the Salter-Harris classification system. However, the median CRP concentration was within the reference values not indicative of inflammation. The CRKF procedure may be a good solution for the treatment of bone fractures, as damaged associated molecular patterns - HMGB-1 and HSP-70 - did not significantly differ 12-14 hours after the approach was applied as compared to the control group. Moreover, the increase in IL-6 concentration after the CRKF procedure was 1.5-fold to the level before CRKF, while the increase of this marker in response to the distal forearm fracture was 4.3-fold compared to the control group. Based on this data, it appears reasonable to suggest that the CRKF approach caused less damage and inflammatory response in comparison to the response to the fracture itself.

Impact of Pregnancy on Loss of Deformity Correction After Pedicle Screw Instrumentation for Adolescent Idiopathic Scoliosis.

OBJECTIVE: A retrospective multicenter comparative study was carried out to evaluate whether pregnancy leads to the loss of deformity correction (LOC) in female patients surgically treated for idiopathic scoliosis. METHODS: A total of 128 female patients who underwent segmental spinal instrumentation and fusion for adolescent idiopathic scoliosis (AIS) between 1999 and 2014 were reviewed. Of these patients, 62 became pregnant (surgery-pregnancy group [SPG]), whereas 66 did not (surgery-nonpregnancy [SNP] group). Radiographic parameters were analyzed before surgery, after surgery, before pregnancy, up to 1 year after delivery, and at final follow-up (FFU). Health-related quality of life was analyzed using the Scoliosis Research Society outcome questionnaire (SRS-22r). RESULTS: The mean age at the time of surgery was 16 years in both groups. The mean preoperative major curves were 65° (standard deviation [SD], 12°) versus 67° (SD, 11°), 18° (SD, 9°) versus 17° (SD, 9°) immediately after surgery, and 20° (SD, 8°) versus 20° (SD, 8°) at FFU in the SPG and SNP groups, respectively (P > 0.10 for all comparisons). The mean loss of correction was 3.5° (SD, 3°) in the SPG and 4.5 (SD, 3°) for SNP groups, respectively (P = 0.379). The mean preoperative thoracic kyphosis (T5-T12) was 26.5° (SD, 11.9°) for SPG and 24.7° (SD, 14.5°) for SNP, after surgery 19.2° (SD, 9.5°) for SPG, 18.8 (SD, 8.9°) for SNP and at FFU, 20.3° (SD, 9°) for SPG and 21.3° (SD, 8.5°) for SNP. CONCLUSIONS: Women who have undergone pedicle screw instrumentation and fusion who have had ≥1 pregnancies do not have curve progression or deterioration in the longer-term outcomes compared with patients who have not become pregnant.

IGF-I and IGF-binding proteins in articular exudates of children with post-traumatic knee damage and juvenile idiopathic arthritis.

OBJECTIVE: IGF-I stimulates multiple functions of connective tissue cells and its activity is modulated by IGF-binding proteins (BPs). Some metalloproteinases are expected to modify IGF-I activity by digestion of IGF-BPs. It was decided to evaluate the concentration of IGF-I, IGF-BPs and the activity of gelatinases A and B in knee exudates of children with post-traumatic damage (PTD) and children with juvenile idiopathic arthritis (JIA) in comparison with those in the sera of the same patients. METHODS: ELISA (for IGF-I assay), polyacrylamine gel electrophoresis following Western immunoblotting (for IGF-I and IGF-BPs expression), and zymography (for gelatinase detection) were used. RESULTS: The knee exudates, especially those taken from patients with JIA, contained large amounts of IGF-I. The exudates of PTD and JIA patients contained some forms of IGF-BP-1 of molecular weight lower than those occurring in serum. Low expression BP-3 and high activity of gelatinase B were detected in the JIA exudates. CONCLUSIONS: The high gelatinase activities in exudates imply joint tissue damage. The cellular response to damage of this kind is an increase in IGF-I production, which stimulates repair processes. High proteolytic activities of gelatinase B in JIA patients may lower the amount of BP-3, possibly causing a relative decrease of IGF-I concentration and impairing the reparation processes stimulated by IGF-I.

Activity of lysosomal exoglycosidases in serum and synovial fluid in patients with chronic Lyme and rheumatoid arthritis.

Lysosomal exoglycosidases participate in the destruction of the articular cartilage by cleaving glycoside bonds in glycoproteins and proteoglycans. The aim of the study was to determine the activity of exoglycosidases: hexosaminidase, beta-glucuronidase, beta-galactosidase, alpha-mannosidase and alpha-fucosidase in serum and synovial fluid of patients with Lyme and rheumatoid arthritis. The study group consisted of 10 patients with chronic Lyme arthritis (age 18 - 74 y), 13 with rheumatoid arthritis (age 32 - 70 y) and 10 with juvenile idiopathic arthritis (age 8 - 17 y). The control group consisted of 9 healthy volunteers (age 24 - 62 y). The activity of the exoglycosidases was determined with the p-nitrophenyl derivatives of sugars as substrates. A significant increase of the activity of all the exoglycosidases in serum and in synovial fluid of the patients with different forms of arthritis was found. The ratio of synovial fluid/serum activity of exoglycosidases was above 2.0 in LA but not in JIA and RA patients. As the main source of exoglycosidases in the joint is the synovial membrane, this result supports the appropriateness of therapeutic synovectomy in chronic Lyme arthritis with knee effusion. The serum activity of hexosaminidase may be used in monitoring the course of Lyme arthritis and the efficiency of treatment.

Minimally Invasive, Arthroscopic-Assisted, Anatomic Posterolateral Corner Reconstruction.

As the anatomy and biomechanics of the posterolateral corner (PLC) of the knee have become better understood, the importance of the PLC's proper function has become a more frequently raised subject. Misdiagnosed chronic posterolateral instability may lead to serious consequences, including cruciate ligament reconstruction graft failure. It has been proved that high-grade PLC injuries need to be treated operatively. Surgical approaches vary, and techniques are still developing. Considering avoidance of an extended surgical approach and minimizing the risk of common peroneal nerve or popliteal artery injuries, we developed the minimally invasive, arthroscopic-assisted, anatomic PLC reconstruction.

All-Arthroscopic Treatment of Schatzker Type III Lateral Tibial Plateau Fracture Without Fluoroscopy.

Tibial plateau fracture treatment remains challenging for orthopaedic surgeons around the world, especially in case of type III fractures according to the Schatzker classification, which are a pure depression of the lateral tibial plateau. Whereas open surgical procedures are associated with increased soft-tissue trauma because of the extent of the surgical approach and do not always allow for proper visualization of the fracture site, arthroscopic-assisted surgeries have been proven to have benefits over the former in terms of minimizing soft-tissue trauma, improved visual control of the fracture reduction, and the time of recovery. Most arthroscopic techniques, however, require using fluoroscopy. We present an all-arthroscopic procedure for Schatzker type III lateral tibial plateau fractures with using a trans-septal portal for visualization, which does not demand fluoroscopy.

Possible Approaches to Endoscopic Treatment of Popliteal Cysts: From the Basics to Troublesome Cases.

Popliteal cysts can be an oppressive symptom in patients with concomitant intra-articular knee pathologies. Because isolated treatment of intra-articular lesions is usually not sufficient to resolve the problems associated with a large symptomatic popliteal cyst, a popliteal cyst should be concurrently addressed with other knee pathologies to maximize patient outcomes. Conservative treatment and open surgical excision are associated with high rates of recurrence, so arthroscopic techniques are the preferred treatment options for recalcitrant cases. Arthroscopic communication-enlargement surgery with cyst wall removal seems to be the most effective. We present a simple and effective basic technique for arthroscopic popliteal cyst treatment and some approaches that allow management of the more demanding cases.

Profile of exoglycosidases in synovial cell cultures derived from human synovial membrane.

OBJECTIVE: Determining the activity of lysosomal exoglycosidases in tissue cultures of synoviocytes derived from the knee joints of patients with injured anterior cruciate ligaments (ACL), juvenile idiopathic arthritis (JIA), and rheumatoid arthritis (RA). METHODS: The following exoglycosidases in cultured synoviocytes were analyzed with p-nitrophenyl derivatives of appropriate sugars as substrates: hexosaminidase (HEX) and its isoenzyme A (HEX-A), beta-glucuronidase (GluA), beta-galactosidase (GAL), alpha-mannosidase (MAN), and alpha-fucosidase (FUC). RESULTS: In our cell cultures, fibroblast-like synovial cells (FLS) dominated. In the group of patients with ACL-injuries, and in the groups of patients with JIA and RA, the activity of the investigated exoglycosidases was significantly higher in the intra- rather than in the extracellular compartment. Hexosaminidase was the predominant exoglycosidase. Stimulation of synoviocytes by IL-1beta in cell cultures significantly increased the activity of HEX, HEX-A, and GluA in both compartments, as well as of GAL, MAN, and FUC in the intracellular compartment. Stimulation by IL-1beta rheumatoidal synoviocytes increased by 128-201% the activity of HEX and HEX A in intracellular compartments and 33-72% in extracellular compartment. CONCLUSIONS: The profile of lysosomal exoglycosidases in a cell culture of human synoviocytes is similar, but not identical, to those in the knee joint. Hexosaminidase is the dominant glycosidase in cultured unstimulated and IL-1beta-stimulated human synoviocytes. The HEX inhibitors may be new drugs for the treatment of inflamed knee joints.

Differential effect of platelet-rich plasma fractions on ß1-integrin signaling, collagen biosynthesis, and prolidase activity in human skin fibroblasts.

The study was conducted to evaluate the effects of platelet-rich plasma (PRP), supernatant of PRP (SPRP) obtained by centrifugation, and supernatant of activated PRP (SActi-PRP) obtained by Ca2+ solution-treated PRP on collagen biosynthesis, prolidase activity, and ß1-integrin signaling in cultured human skin fibroblasts. Incubation of fibroblasts with 5% PRP for 24 h contributed to ~5-fold increase in collagen biosynthesis compared to the control. In the cells treated with 5% of SPRP or SActi-PRP, collagen biosynthesis showed a 3-fold increase of the control. PRP, SPRP, and SActi-PRP stimulated prolidase activity similar to collagen biosynthesis. Collagen biosynthesis and prolidase activity are regulated by ß1-integrin receptor signaling. Incubation of fibroblasts with PRP for 24 h contributed to a dose-dependent increase in the expression of ß1-integrin receptor, while SActi-PRP increased the process to a much lower extent. SPRP had no effect on the ß1-integrin receptor expression. All the studied fractions of blood increased the expression of FAK as well as the expression of phosphorylated MAP-kinases. However, PRP was found to be the most effective stimulator of expression of these particular kinases. These studies suggest that a complex of factors, including growth factors, adhesion molecules, and prolidase contained in PRP, all evoke growth and collagen-promoting activities in human dermal fibroblasts.