Anders Kalén

Fibroblast proliferation due to exposure to a platelet concentrate in vitro is pH dependent

The influence of platelet‐rich plasma lysates on fibroblast proliferation was studied in culture. Cells were exposed to platelet lysates that had been preincubated at different pHs (5.0, 7.1, and 7.6). Proliferation was evaluated with the MTT assay and incorporation of [3H]thymidine into macromolecules, while type I collagen production was assayed by Western blotting. Enzyme‐linked immunosorbent assays were used to determine platelet‐derived growth factor and transforming growth factor‐β concentrations. Platelets preincubated in an acidic environment (pH 5.0) induced the highest degree of fibroblast proliferation, and the concentration of platelet‐derived growth factor in the different treated lysates was the highest at that particular pH. The concentration of transforming growth factor‐β, however, was lower after incubation at pH 5.0 than at either pH 7.1 or 7.6. These findings may be relevant to normal wound healing in vivo and useful in the treatment of wounds and delayed healing processes. (WOUND REP REG 2002;10:336–340)

Fusion of the EWSR1 and ATF1 genes without expression of the MITF-M transcript in angiomatoid fibrous histiocytoma.

Angiomatoid fibrous histiocytoma (AFH) is a rare soft tissue tumor that usually occurs in children and young adults. Only two cases of AFH with genetic rearrangements have been reported previously; both of these had a FUS–ATF1 fusion gene. We have studied an AFH from a 9‐year‐old boy whose tumor displayed a t(12;22)(q13;q12) as the sole cytogenetic aberration. FISH,RT‐PCR, and sequence analyses revealed an EWSR1–ATF1 fusion gene that has previously been reported in clear cell sarcoma (CCS), a soft tissue sarcoma that is morphologically and clinically distinct from AFH. This study thus has demonstrated that the EWSR1–ATF1 chimera represents a fusion gene that can be associated with different tumor types. Simultaneous expression of the EWSR1–ATF1 and MITF‐M transcripts in CCS has led to the proposal that the MITF‐M promoter is transactivated by EWSR1–ATF1. The AFH, however, did not express the MITF‐M transcript, supporting the theory that MITF‐M expression in CCS is a reflection of its cellular origin, rather than a consequence of the presence of an EWSR1–ATF1 fusion protein. Activation of the EWSR1–ATF1 oncogene is probably an early step in the transformation process, but the overall gene expression patterns are likely to vary considerably between AFH and CCS, in keeping with their clinicopathologic differences.

The Scandinavian Sarcoma Group skeletal metastasis register: Survival after surgery for bone metastases in the pelvis and extremities

INTRODUCTION The assessment of the prognosis for the individual patient is important for the choice of surgical treatment of skeletal metastases. In 1999 the Scandinavian Sarcoma Group (SSG) initiated the Skeletal Metastasis Register as a multicentric, prospective study to provide a scientific basis for treatment recommendations. To improve prognostication we analyzed the survival of patients with skeletal metastases surgically treated at 9 SSG centres. PATIENTS AND METHODS 460 patients with an average age of 64 years underwent 501 operations for non-spinal skeletal metastases. 7% were operated for more than one metastasis. Carcinoma of the breast, prostate, kidney and lung were the dominating primary tumors. RESULTS The survival rate was 0.4 at 1 year, 0.3 at 2 years and 0.2 at 3 years. Univariate analysis showed that survival was related to bone localization, skeletal metastatic load, presence of visceral metastases, Karnofsky performance score, primary tumor type, presence of a complete pathological fracture and preoperative hemoglobin content. Multivariate regression analysis showed that pathological fracture, visceral metastases, haemoglobin content < 7 mmol/L and lung cancer were negative prognostic factors for survival. Myeloma was the sole positive prognostic factor for survival.

Insight opinion to surgically treated metastatic bone disease: Scandinavian Sarcoma Group Skeletal Metastasis Registry report of 1195 operated skeletal metastasis.

The number of cancer patients living with metastatic disease is growing. The increased survival has led to an increase in the number of cancer-induced complications, such as pathologic fractures due to bone metastases. Surgery is most commonly needed for mechanical complications, such as fractures and intractable pain. We determined survival, disease free interval and complications in surgically treated bone metastasis. Data were collected from the Scandinavian Skeletal Metastasis Registry for patients with extremity skeletal metastases surgically treated at eight major Scandinavian referral centres between 1999 and 2009 covering a total of 1195 skeletal metastases in 1107 patients. Primary breast, prostate, renal, lung, and myeloma tumors make up 78% of the tumors. Number of complications is tolerable and is affected by methods of surgery as well as preoperative radiation therapy. Overall 1-year patient survival was 36%; however, mean survival was influenced by the primary tumor type and the presence of additional visceral metastases. Patients with impending fracture had more systemic complications than those with complete fracture. Although surgery is usually only a palliative treatment, patients can survive for years after surgery. We developed a simple, useful and reliable scoring system to predict survival among these patients. This scoring system gives good aid in predicting the prognosis when selecting the surgical method. While it is important to avoid unnecessary operations, operating when necessary can provide benefit.

Prognostic role of en-bloc resection and late onset of bone metastasis in patients with bone-seeking carcinomas of the kidney, breast, lung, and prostate: SSG study on 672 operated skeletal metastases.

In metastatic disease, decisions regarding potential surgery require reliable data about the patients survival. In this study, we evaluated different prognostic factors and their impact in four common primary tumors causing bone metastases.

The content of bone morphogenetic proteins in platelets varies greatly between different platelet donors

Platelet derivates and platelet rich plasma have been used to stimulate bone formation and wound healing because of the rich content of potent growth factors. However, not all reports have been conclusive since some have not been able to demonstrate a positive effect. We investigated the interindividual variation of bone morphogenetic proteins (BMPs) in platelets from healthy donors, and the pH-dependent effect on the release of BMPs in preparations of lysed platelets in buffer (LPB). Platelet concentrates from 31 healthy donors were prepared in pH 4.3 and pH 7.4 buffers and investigated with respect to BMP-2, -4, -6, and -7. BMP-2 and BMP-4 were significantly more common in acidic LPBs in comparison with neutral preparations. We also observed a considerable variation among platelet donors with respect to the release of BMPs at pH 4.3 and 7.4. In conclusion, a considerable variation was found among platelet donors, which may be of importance considering the ambiguous results previously reported on osteoblast proliferation and differentiation.

Preparation for becoming members of health care teams: findings from a 5-year evaluation of a student interprofessional training ward

Setting. An orthopaedic interprofessional training ward manned by students at a University Hospital.Objective. To assess to what extent students from different undergraduate programmes evaluated the effects of a 2-week rotation at the ward on their professional roles and the value of teamwork within health care.Method. A questionnaire was filled in by 841 students by the end of a 2-week rotation at the ward over 5 years. Questions concerned students’ estimate of how the rotation had strengthened their insight into their own future professional role, into other students’ professional roles and into the value of teamwork within health care. Differences between the different student categories and possible associations between the different estimates were statistically analysed.Results. Students from all programmes reported that the rotation at the student ward had dramatically strengthened their insight about their own future professional role as well as the roles of the other professions and the value of teamwork within health care.Conclusion. Health care is a complicated system based on cooperation and professionalism. We suggest that interprofessional training of students from all professions within health care should be a part of their education as a worthwhile preparation for their future professional work and to ensure high-quality health care.

Complications and survival after surgical treatment of 214 metastatic lesions of the humerus

BACKGROUND The humerus is the second most common long-bone site of metastatic bone disease. We report complications, risk factors for failure, and survival of a large series of patients operated on for skeletal metastases of the humerus. MATERIALS AND METHODS This study was based on 208 patients treated surgically for 214 metastatic lesions of the humerus. Reconstructions were achieved by intramedullary nails in 148, endoprostheses in 35, plate fixation in 21, and by other methods in 10. RESULTS The median age at surgery was 67 years (range, 29-87 years). Breast cancer was the primary tumor in 31%. The overall failure rate of the surgical reconstructions was 9%. The reoperation rate was 7% in the proximal humerus, 8% in the diaphysis, and 33% in the distal part of the bone. Among 36 operations involving an endoprosthesis, 2 were failures (6%) compared with 18 of 178 osteosynthetic devices (10%). In the osteosynthesis group, intramedullary nails failed in 7% and plate fixation failed in 22%. Multivariate Cox regression analysis showed that prostate cancer was associated with an increased risk of failure after surgery (hazard ratio, 7; P < 0.033). The cumulative survival after surgery was 40% (95% confidence interval [CI] 34-47) at 1 year, 21% (95% CI, 15-26) at 2 years, and 16% (95% CI, 12-19) at 3 years. CONCLUSIONS Our method of choice is the cemented hemiprosthesis for pathologic proximal humeral fractures and interlocked intramedullary nail for lesions in the diaphysis. Pathologic fractures in the distal humerus are uncommon and associated with a very high reoperation rate.

Variation of pH in lysed platelet concentrates influence proliferation and alkaline phosphatase activity in human osteoblast-like cells

Activated platelets release a multifaceted blend of growth factors that has stimulatory effects on mesenchymal cells, both in vitro and in vivo, which imply beneficial effects on wound repair and tissue regeneration. Previous studies on fibroblast cultures have revealed that more potent growth factors, with respect to cell proliferation, are released in acidic preparations of lysed platelet concentrates in comparison with neutral and alkaline preparations. The current study was intended to investigate the influence of pH on lysed platelet concentrates with respect to release of growth factors, cell proliferation and alkaline phosphatase (ALP) activity in human osteoblast-like cells (hFOB 1.19). Cell proliferation was assessed with the MTT kit, ALP activity by conventional enzymatic reaction kinetics and growth factors platelet-derived growth factor (PDGF) and transforming growth factor-β (TGF-β) by enzyme-linked immunosorbent assays. Osteoblast-like cells were stimulated with lysed platelet concentrates preincubated at pH 4.4, 5.4, 7.4, and 7.6. A 3–13-fold increase of cell proliferation was found in comparison with controls and the most evident increase was observed with platelets activated at pH 5.4. The highest ALP activity was observed in preparations at pH 7.6. Platelets incubated in an acidic environment (pH 5.4) induced a higher proliferation compared with preincubation at neutral or alkaline pH and the level of PDGF was also found to be higher in acidic preincubations. The level of TGF-β was, in contrast, lowest at pH 4.4. We suggest, based on these experimental findings, that acidic milieu influence platelets to release growth factors more potent to stimulate osteoblast proliferation than neutral and alkaline platelet preparations. Lysed platelet concentrates prepared at an alkaline pH might release additional components with stimulating effects resulting in other features than cell proliferation. This is the first report, to our knowledge, about a pH dependent stimulatory effect of lysed platelet concentrates on human osteoblast-like cell proliferation. Lysed platelet concentrates, preincubated in acidic or alkaline buffers, may benefit fracture healing, implant fixation and might also be advantageous in the treatment of wounds with platelet constituents; however, this has to be investigated in extended experimental and clinical settings.

Acidic preparations of platelet concentrates release bone morphogenetic protein‐2

Background and purpose Growth factors released from platelets have potent effects on fracture and wound healing. The acidic tide of wound healing, i.e. the pH within wounds and fractures, changes from acidic pH to neutral and alkaline pH as the healing process progresses. We investigated the influence of pH on lysed platelet concentrates regarding the release of growth factors. Material and methods Platelet concentrates free of leukocyte components were lysed and incubated in buffers with pH between 4.3 and 8.6. Bone morphogenetic protein-2 (BMP-2), platelet‐derived growth factor (PDGF), transforming growth factor-β (TGF-β), and vascular endothelial growth factor (VEGF) were measured by quantitative enzyme‐linked immunosorbent assays. Results PDGF, TGF-β, and VEGF were present in all platelet preparations but the levels varied in a pH‐dependent fashion. BMP-2 was only detected in the most acidic preparation (pH 4.3), which is interesting since BMP-2 has been reported to be an endogenous mediator of fracture repair and to be responsible for the initiation of fracture healing. Interpretation Our findings indicate that platelets release substantial amounts of BMP-2 only under conditions of low pH, the milieu associated with the critical initial stage of fracture healing.