Antifungal properties of silver coating on tumour endoprostheses: an in vitro study

OBJECTIVE

We tested and quantified the in vitro effect of silver coating on preventing development of fungal biofilm over titanium, as found in some megaprosthesis used for musculoskeletal oncological reconstruction, to evaluate the antiseptic effect of this additional feature on this class of pathogens.

MATERIALS AND METHODS

Different strains and species of Candida (C. albicans, C. tropicalis, C. parapsilosis) were cultured over 6 silver-coated and 6 non silver-coated titanium (Ti-6Al-4V) samples following a standardized procedure. Then spectrophotometrical analysis and viability assay were conducted after 5 days of incubation to quantify the different extension of biofilm produced by pathogens RESULTS: Significant differences between groups (p<0.05) were found in terms of biofilm extension and pathogens viability over the different materials for any single experiment reported, with silver-coating group showing substantially lower values in terms of fungal development in all conducted assays.

CONCLUSIONS

The results suggest that silver coating is a reliable and effective implementation for antifungal purpose, in addition to its widely known and demonstrated antibacterial potential. Therefore, the use of silver-coated implants may be an even wiser choice in an oncological surgical procedure where patients are particularly at risk for this infective complication due to immunosuppression caused by pharmacological treatments, although the relevant antifungal potential here shown needs to be confirmed in vivo.

Clinical and radiographic outcomes in patients operated for complex open tibial pilon fractures

AIM

To report clinical and radiographic results of treatment of patients with complex open tibial pilon fractures.

METHODS

A retrospective analysis in 14 patients with complex open pilon fractures treated between 2010 and 2015 was conducted. The injuries were graded according to AO Classification and the Gustillo-Anderson system. Routine follow-up was performed at 1, 3, 6, 12 month with an annual evaluation thereafter. All patients were included for the assessment of the rate of infection, wound and fracture-healing. Functional outcome assessment was performed in all patients according to the American Orthopedic Foot and Ankle Score (AOFAS) at 12 months after the injury. The radiological outcome was evaluated through standard XR using the criteria proposed by Burwell and Charnley.

RESULTS

Analysis were conducted in 12 men and 2 women, with a mean age of 50.4 years (20-77) who were followed up for an average 34 months (range: 9-60 months). All patients had a AO type 43C fracture. There were three Gustilo Type IIIA injuries, seven Type III B and four Type III C. The mean time to fracture healing was 6.3 months. 4 patients underwent definitive treatment with external fixation at the time of the initial irrigation and debridement. 10 patients underwent delayed definitive surgery: in 10 patients ORIF was used. Soft-tissue coverage by vascularized muscle flap was necessary in 4 patients (28%) and was typically performed on the day of definitive fixation. One patient required iliac crest bone-grafting. 4 patients (28%) had a deep infection.6 patients (43%) had a superficial pin infection or cellulitis. 6 patients (43%) presented delayed union. The average AOFAS score was 71.5 (40-95). According to the Burwell-Charnley score, the anatomical reduction of the fracture was obtained in 50% of patients and a good reduction in 86% of cases. 5 patients (35.7%) had loss of joint congruity and evidence of osteoarthritis on radiographs at final follow-up. No patient needed arthrodesis or amputation.

CONCLUSION

The results of our study suggest that open tibial pilon fractures can be safely managed with low rate of complications using intensive debridement, antibiotics, adequate devices and patient-tailored timing of definitive surgical treatment.

Arthrodesis of the ankle joint in septic osteoarthritis: six years long term outcomes in authors' personal experience

OBJECTIVE

Our goal was to evaluate the long-term clinical outcome of ankle arthrodesis, obtained by an extramedullary internal fixation with or without bone-grafting in the treatment of ankle' septic arthritis.

PATIENTS AND METHODS

All patients treated with arthrodesis by extramedullary internal fixation for septic arthritis of the ankle joint between January 2011 and December 2016 in the same hospital were included in our retrospective study. Patients were followed-up for a minimum of two years. To evaluate the quality of life, each patient filled in a short form of the physical and mental health summary scale and a visual analogue scale for pain. For the functional evaluation, the American Orthophaedic Foot and Ankle Society Score was used. Demographics and clinical data, including perioperative and postoperative complications, were evaluated.

RESULTS

From January 2011 to December 2016, we performed 57 arthrodeses of the ankle joint with cannulated screws in 52 patients. Mean age was 52 years old. 48 patients (92%) had post-traumatic septic arthritis. The most frequently isolated pathogens were Staphylococcus aureus and Pseudomonas aeruginosa. 48% of patients reported a postoperative complication after three months; the most commonly reported complications were weight bearing ankle-foot pain (27%) and surgical wound dehiscence (12.25%). Nonunion was reported only in 8.75% of cases.

CONCLUSIONS

Ankle arthrodesis could allow painless gait, improving patients life quality, even after long-term follow-up, and is, therefore, a solution to be considered in patients affected by septic arthritis.

Radioguided Biopsy of Osteoid Osteoma: Usefulness of Imaging Probe

Aims and Background

When removal of osteoid osteoma is performed with open biopsy, the surgeon can be guided by radioactivity of 99mTc-MDP (methylene D- phosphonate) acquired by a probe.

Material and methods

We compared the performance of a commercially available ZnCdTe probe (Neoprobe 2000) and a one-square-inch-field-of-view imaging probe (IP) on two patients undergoing open biopsy for osteoid osteoma. Triphasic bone scintigraphy was performed before operation and Neoprobe as well as IP were used in the operating room by two nuclear physicians. When the surgeon asked for guidance, each nuclear physician had to indicate a precise direction.

Results

The surgeon asked for guidance once in the first operation, on a patient with osteoid osteoma of the femur, and four times in the second operation, for osteoid osteoma of the acetabulum. The indications provided by IP were correct 5/5 times, whereas the commercial probe was correct 3/5 times. Both devices were able to assess the surgical radicality. After biopsy, bone samples were divided into high-count and low-count samples. Pathological examination confirmed the presence of osteoid osteoma in high-count samples.

Conclusions

IP has already been used to guide biopsy, but only in breast disease. The present work confirms its good performance also in orthopedics as a portable mini gamma camera that can be used in the operating room.

Scanning electron, 3D-confocal and stereotactic microscopies morpho-structural analysis of antibiotic-loaded cement porosity in three different formulations

Chronic osteoarticular infections such as osteomyelitis or periprosthetic joint infection (PJI) have become a growing problem over the years. The “gold standard” in local antibiotic administration is still the antibiotic-loaded acrylic bone cement (ALABC) which is used in both prophylaxis, because it has been shown it can reduce the risk of infection and used in therapy during a “two-stage surgery” in PJI or in chronic osteomyelitis. We performed morphological analysis of three different formulations of antibiotic-loaded cement (ALABC) using techniques of light microscopy, scanning electron microscopy (SEM) and 3D immunofluorescence, in order to explain how the morphological aspects of cement could influence and modulate antibiotic elution.

Soft tissue adhesion patterns over Trevira tube on modular endoprosthesis for malignant bone tumours: an in vitro study

A reliable and effective technique in case of limb salvage surgery after resection of extensive bone tumors is represented by the implant of modular or custom-made megaprosthesis. Fixation of the residual surrounding soft tissue on the implant represent a challenge for the surgeon and the use of a polyethylene terephthalate (PET) tube over it, also known as Trevira, is currently a common choice for reattachment with good clinical outcomes. We compared fibroblastic cell culture potential over simple titanium coating vs titanium surrounded by Trevira and evaluated cell viability and replication at 24, 48 and 72 h using MTT cell growth assay and scanning electron microscopy to determine if there was any difference in the potential of cell growth associated to the material used. No significant difference was found at different timings in terms of total cell count for cultures over the two materials, but the absolute cell count was slightly higher in the Trevira group in the early time points, reversing the trend at 72 h of incubation. Ninety-four % of the cells analyzed were vital, regardless of the materials involved in the experiment, confirming the biocompatibility of titanium and PET. According to the results shown, we are able to confirm the in vitro safety and efficacy, in terms of newly formed cells extension and adhesion pattern, of using an attachment tube made from Trevira fibers surrounding an oncological megaprosthesis in order to achieve the most anatomical reinsertion of remaining soft tissue following resection.

Quantitative study on Vancomycin release from cement in 3 different formulations: preliminary results and antimicrobial activity

The purpose of this study is to investigate the best preparation method of the cement powder mixture, solvent and antibiotic in order to obtain the greatest amount of antibiotic in the joint for the longest time as possible. At time T0 the three samples, packed in a sterile environment in different formulations, were placed in sterile tubes, adding to each one 5 ml of saline phosphate buffer solution (PBS) and put in a stove at 37°C for 24 h. A sample of PBS without cement (T control) was also created. Qualitative and quantitative assessment of the incubated liquid with cement was performed along with biochemical analysis with High Performance Liquid Chromatography (HPLC). The analysis of the raw data demonstrated that at T1 there was a prevalence of antibiotic release from sample , compared to sample 2 and 3. This difference was maintained until the T20; from T21 the antibiotic release gradually leveled in 3 samples. The elution of the antibiotic remained detectable up to T60. Our work shows that the sample preparation is decisive on the quantity of released antibiotic. These results are confirmed by microbiological tests. It is useful to know the actual kinetics of antibiotics in articulation. Further studies are necessary to determine the effectiveness of antibiotic against micro-organisms and how long it acts.

Treatment options of simple bone cysts: the role of bone substitutes, growth factors and literature review

The solitary bone cyst is a typical tumor-like lesion of the immature skeleton, whose etio-pathogenesis is still unclear. The purpose of this work is to perform a review of the literature about the different surgical approaches focusing on the role of bone substitutes and growth factors. Literature analysis shows injection techniques of substances such as methylprednisolone, autologous bone marrow, demineralized bone matrix, calcium sulphate and surgical techniques that involve the resection and curettage associated with bone graft and/or intramedullary nailing. Although there are good results currently associated to these techniques and the different ways of treatment, the only evidence-based treatment is given by injections of steroids. However, given the high rate of failure, autologous bone marrow and platelet gel represent a viable therapeutic option.

Bone marrow concentrated cells and stromal vascular fraction cells injections for osteoarthritis treatment: a systematic review

The aim of this systematic review is to examine current clinical evidences supporting the intraarticular injection of bone marrow concentrate cells (BMC) and adipose-derived stromal vascular fraction cells (SVF) for the treatment of osteoarthritis (OA). The research was performed on PubMed (Medline), EMBASE and Cochrane Library considering the English literature. Only clinical trials have been included. The systematic research identified twelve clinical trials. Articles included in the study, were one of level II, four of level III, six of level IV and one level V. Among clinical trials, none were randomized, four were comparative, seven were case series, and one was a case report. Seven studies were focused on the use of SVF (1332 patients) and five on the use of BMC (963 patients), with preliminary interesting findings in the OA treatment. Despite the growing interest in this biological approach for OA, knowledge on this topic is still preliminary. Randomized controlled trials are needed to support the potential of BMC and SVF injections and to evaluate advantages and disadvantages with respect to the available treatments.

SILVER COATED PROSTHESIS IN ONCOLOGICAL LIMB SALVAGE SURGERY REDUCE THE INFECTION RATE

Silver coatings, used in many surgical devices, have demonstrated good antimicrobial activity and low toxicity. Oncological musculoskeletal surgery have a high risk of infection, so in the last decades, silver-coated mega-prostheses have been introduced and are becoming increasingly widespread. In this study, a retrospective analysis of 158 cases of bone tumors, primary or metastatic, treated between 2005- 2015 with wide margins resection and tumor implants reconstruction, was performed. The average age was 59 years (range 11-78 years), the same surgeon with antibiotic prophylaxis according to a standard protocol treated all patients. Silver-coated prostheses were implanted in 58.5% of patients and uncoated tumor prostheses in the remaining 41.5%. Patients were re-evaluated annually and complications were recorded, focusing analysis on infective complications. The average follow-up was 39.7 months: 23.4% of patients died at a median time of 35.3 months after surgery; 18.4% developed complications that required new surgery, of which 12.6% of these were due to infection. Patients treated with silver-coated implants developed early infection in 2.2% of cases against the 10.7% of the patients treated with standard tumor prosthesis. This difference between the two groups was statistically significant. The percentage of late infections occurring from 6 months after surgery was similar in both groups. Silver blood level taken in a sample of patients at different times after surgery, always showed values well below the threshold of toxicity and no patient showed any sign of local or general toxicity secondary to silver. Our study demonstrates that tumor silver-coated implants have a rate of early infection significantly lower than traditional implants, while there were no differences in the rate of late infections as described also in the literature. We recommend the use of silver–coated prosthesis as primary implants for limb salvage surgery in primary or metastatic bone tumors, considering the absence of toxicity and the lower rate of early infection.

Mechanical and biological results of short-stem hip implants: consideration on a series of 74 cases

BACKGROUND

The aim of this survey was to show mid-term outcomes of a short-stem cementless hip prosthesis with metaphyseal fit and fill.

METHODS

Case series is on 74 implants in 67 patients, implanted from June 2006 to December 2010 with an average follow-up of 48 months (range 36-90 months).

RESULTS

In their case series, authors found some pitfalls as varus or valgus alignment, heterotopic ossification, aseptic mobilization with subsidency, and malpositioning. According to Harris Hip Score, postoperative clinical outcomes were excellent-good (84 %) and fair-poor (16 %).

CONCLUSIONS

At a mid-term follow-up, the investigated implant showed a strong stability and some well-tolerated mechanical and biological pitfalls.

Algorithm for the management of femoral shaft fractures in children

PURPOSE

Pediatric closed femoral shaft fractures are commonly related to a good prognosis. There is no consensus on treatment. We aimed to evaluate the treatment, features, radiological findings and management strategies, creating an algorithm of treatment.

MATERIALS AND METHODS

Fifty-two simple femoral shaft fractures in children were retrospectively evaluated for age and gender distribution, side of the fracture, etiology of injuries, limb length discrepancy, range of knee and hip motion and parents satisfaction with a mean clinical and radiographic follow-up of 3 years and 6 months. Twenty-eight patients were treated with reduction and early hip spica cast while 24 patients were treated with external fixation (EF).

RESULTS

Nearly 58 % of the cases were caused by traffic accidents and were predominantly male (61.5 %). Most of the fractures were of the middle femoral shaft (57.6 %). Muscle strength was normal (MRC scale) in all patients with no pain (NIPS and PRS scale). Knee and Hip range of motion were similar in both types of treatment. Patients treated with EF had shorter limb length discrepancy compared with SC. There were no reports of re-fracture. We found a higher familiar satisfaction in patients treated with EF.

CONCLUSIONS

An algorithm for the management of femoral shaft fractures in the pediatric population is proposed. Results on the study population gave raise to a satisfactory clinical and radiological results.

Immunoexpression of lactoferrin in bone metastases and corresponding primary carcinomas

Although the immunohistochemical presence of lactoferrin (LF) in pathological neoplastic bone and cartilage samples has previously been studied, no data concerning the distribution of LF in bone metastases of cancers that have originated from different organs are available at present. Consequently, using a monoclonal antibody, we have investigated the immunohistochemical LF pattern in 50 formalin-fixed and paraffin-embedded samples of human bone metastases and their corresponding primary carcinoma tumours (breast, 8; prostate, 4; kidney, 4; lung, 3; colon-rectum, 2 and uterus, 4). Quantification of LF immunoreactivity was performed using an intensity distribution (ID) score. LF immuno staining with a variable ID score was encountered in 11/25 (44%) metastatic lesions. In particular, the LF immunoreactivity was identified with a percentage ranging from 50 to 75% of bone metastases due to prostatic, renal, uterine and colorectal carcinomas; the positivity decreased in breast carcinomas (37.5%) and was completely absent in lung cancers. No differences in the LF-ID score were observed between primary and metastatic neoplastic localisations. Additionally, no correlations were identified between LF immunoexpression and the other parameters tested, including the age and gender of patients. Regardless of the mechanism of action of LF in human malignant tumours, we identified LF immunohistochemical reproducibility at primary and metastatic sites. Therefore, we hypothesise that the presence of LF in native neoplastic carcinomatous clones is maintained in secondary bone metastatic deposits.

Local adjuvants in surgical management of bone metastases

Curettage is one of the most common method for surgical treatment of bone metastasis. Local adjuvant improve most commonly used for improving the effect of curettage in local cancer surgery may exerted their effects either chemically either physically; in Orthopedic Oncology the most common are phenol, liquid nitrogen, laser, and cement. This article reviewed the main characteristics of the most common chemical and physical agents used in bone oncology, emphasizing the toxic effects of some of them, especially phenol and liquid nitrogen.

Angiogenesis in hand chondroma: an immunohistochemical study

Hand chondroma is a particular cartilagineous tumour, being clinically benign, but morphologically malignant. This study investigates the expression of VEGF together with other growth factors and proliferation markers such as TGFβ2, Ki-67, TNF, FGF1, P53 in 8 cases of hand chondroma treated with courettage, in order to define the ethiopathogenesis of this tumour and the clinical significance of the resulting immunohistochemical profile, with particular respect to angiogenesis. VEGF was expressed in all cases; 5 cases were positive for TFGβ2 and 3 for PDGF. None of the other factors was expressed. On the basis of histologic results a specific model of tumour progression based on the indicators of angiogenesis could be related to hand tumours, in which VEGF expression should be the first stadium of the tumour aggressiveness, and the following PDGF, TGF 2 expression should be accompanied with a morphological outline worsening. Nevertheless the non constant expression of these indicators and the absent expression of proliferated indicators can explain the scant tendency to the relapse in presence of accurate curettage. It is important to remember that the cellular polymorphism typical of the cartilaginous tumours does not allow the application of an only oncogenesis model.

Isolated bone lesion secondary to hyperparathyroidism: diagnostic considerations

Authors describe two cases of bone lesions ("brown" tumour) secondary to hyperparathyroidism in whom incisional biopsy gave an incorrect diagnosis. The first case was a patient with a lesion of the right femur diagnosed as aneurismal cyst and; the second case was a patient with an isolated lesion of the distal metaphysic of right humerus firstly diagnosed as giant cells tumour. Treatment of the first case was resection and diaphyseal spacer, and the correct diagnosis of brown tumour was performed for the multiple tibial localizations appeared six months later. The second case was diagnosed as affected by a brown tumour secondary to hyperparathyroidism on the basis of clinical history and laboratory analysis. Both diagnoses were firstly incorrect and would have brought to an inadequate treatment with consequences on patients quality life. Differential diagnosis is discussed and the importance to evaluate all the diagnostic data to formulate a correct diagnosis is stressed.

Methotrexate-added acrylic cement: biological and physical properties

BACKGROUND

Previous reports have demonstrated the suitability of adding different chemotherapeutic drugs to acrylic cement for the treatment of bone metastases. The best results so far have been obtained with methotrexate (MTX) for which diffusion from the implanted cement has been demonstrated both in vitro and in vivo. In this study the suitability of adding MTX to acrylic cement as local adjuvant chemotherapy was investigated.

METHODS

Using an in vitro model of human breast cancer cells we demonstrated that the drug is eluted in an active form able to exert a cytotoxic effect over a long period of time. The use of different concentrations of drug on the kinetic of elution and on the mechanical properties of cement was also evaluated.

RESULTS

The results obtained suggest that the release of MTX is higher at the beginning and progressively decreases over time being affected by the concentration of drug used. Our results also demonstrated that the addition and the subsequent elution of MTX does not alter the compressive properties of the cement.

CONCLUSION

These findings confirm the suitability of MTX-supplemented cement and support its use as an effective aid for the management of bone metastases requiring surgical curettage and acrylic cement implantation for structural support.

Endoprosthetic replacement for malignant bone tumours of the proximal femur

Limb salvage procedures are considered the gold standard in the treatment of bone tumours. The use of modular prostheses is one of the options for reconstruction after bone resection in primary tumours and in very restricted cases also in bone metastases. The authors report the results of 27 consecutive cases of proximal femur bone resections and reconstructions with modular prostheses, using the Mutars system. Soft tissue reconstruction and anchorage to the implant was performed using the Trevira tube. The system stem used showed good mechanical resistance, and implant removal was required for infection in only two cases. Functional results were related to the degree of bone resection and muscular sacrifice. (Hip International 2005; 15: 218-22).

Application of ozonation process in industrial wastewaters: textile, kraft E1 and whey effluents

A large variety of organic and inorganic compounds can be found in wastewater from industrial processes. In this work, Advanced Oxidative Processes (AOPs) have been applied for the control of water pollution and the ozonation of different effluents was investigated. Wastewater from textile, kraft E1 and cheese manufacturing processes were chosen as examples of industrial effluents. The efficiency of substrate mineralization has been comparatively analyzed by the decrease in total organic carbon (TOC), color, and toxicity. The results revealed that the ozonation process can be a method for decolorization of effluent, but it is not effective for TOC reduction. The whey effluent was the most recalcitrant wastewater for ozone treatment which produced no TOC removal.

Acrylic cement added with antiblastics in the treatment of bone metastases. Ultrastructural and in vitro analysis

An increased long-term survival of patients with alignant tumours also increases the possibility of the development of skeletal metastases and pathological fractures. The management of bone metastases includes the removal of gross disease and the administration of local adjuvants. We have investigated the possibility of adding antiblastic drugs to acrylic cement. Cylinders of acrylic cement were manufactured containing three different antiblastic drugs, methotrexate, cisplatin and doxorubicin. We performed in vitro analysis on MCF-7 human breast cancer cells in order to evaluate the biological effect of the mixtures and surface analysis of the acrylic cement-cisplatin cylinders using energy-dispersive x-ray analysis (EDAX). All drugs were released in an active form from the cement. Each drug had a different effect on cell viability. Doxorubicin had the greatest effect on breast cancer cells. Surface analysis showed that antiblastic drugs were present in the form of granules. These results confirm the potential of antiblastic-loaded cement as a possible adjuvant in the local treatment of bone metastases. Further studies should be undertaken to determine whether the release of antiblastic drugs from cement is elution or if they are only released from the surface.

Acrylic cement added with antiblastics in the treatment of bone metastases

An increased long-term survival of patients with malignant tumours also increases the possibility of the development of skeletal metastases and pathological fractures. The management of bone metastases includes the removal of gross disease and the administration of local adjuvants. We have investigated the possibility of adding antiblastic drugs to acrylic cement.

Cylinders of acrylic cement were manufactured containing three different antiblastic drugs, methotrexate, cisplatin and doxorubicin.

We performed in vitro analysis on MCF-7 human breast cancer cells in order to evaluate the biological effect of the mixtures and surface analysis of the acrylic cement-cisplatin cylinders using energy-dispersive x-ray analysis (EDAX). All drugs were released in an active form from the cement. Each drug had a different effect on cell viability. Doxorubicin had the greatest effect on breast cancer cells. Surface analysis showed that antiblastic drugs were present in the form of granules.

These results confirm the potential of antiblastic-loaded cement as a possible adjuvant in the local treatment of bone metastases.

Further studies should be undertaken to determine whether the release of antiblastic drugs from cement is elution or if they are only released from the surface.

Leukocyte, platelet and endothelial activation in patients with acute renal failure treated by intermittent hemodialysis

BACKGROUND

Using different types of dialysis membranes to treat acute renal failure (ARF), clinical and experimental studies have demonstrated discordant results relatively to the effect of membrane bioincompatibility on patient outcome. Nevertheless, there are few data on the biocompatibility indices in patients with ARF who need to be treated by hemodialysis.

OBJECTIVE

To characterize the impact of intermittent hemodialysis (IHD) on indices of leukocyte, platelet and endothelial activation in patients with ARF.

PATIENTS AND METHODS

We prospectively studied 27 patients with severe ARF treated by IHD. They were characterized relatively to gender, age, ARF etiology, urinary output per 24 h, Simplified Acute Physiology Score (SAPS), number of dialysis sessions and outcome. We evaluated the effect of hemodialysis with two types of low-flux dialyzers (cuprophane and polysulfone dialyzers) on plasma concentrations of soluble TNF-RI (TNF-sR55), TNF-RII (TNF-sR75), interleukin (IL)-6, soluble CD23 molecule, soluble P-selectin and von Willebrand factor (vWF).

RESULTS

There were no significant differences between the two groups of patients dialyzed with cellulose-based and synthetic membranes in terms of age, sex, urinary output per 24 h, SAPS, number of dialysis sessions and mortality. We verified high plasma concentrations of TNF-sR55, TNF-sR75, IL-6, sCD23, sP-selectin and vWF in the global population studied. Patients dialyzed with cuprophane membranes showed significantly lower pre- and postdialysis concentrations of sP-selectin than patients dialyzed with polysulfone membranes. After a hemodialysis session, with correction for differences of blood hematocrit, we did not observe any significant modification in the concentrations of TNF-sR55, TNF-sR75, IL-6, sP-selectin and vWF of the plasma. On the other hand, a significant increase of sCD23 molecule was found in the group dialyzed with polysulfone membranes (p = 0.009).

CONCLUSIONS

The group of 27 patients with ARF who needed IHD, showed increased plasma concentrations of some leukocyte, platelet and endothelial activation markers (TNF-sR55, TNF-sR75, IL-6, sCD23, sP-selectin and vWF). These mediators characterize the inflammatory and procoagulant state associated with this pathologic condition. After a hemodialysis session with these low-flux membranes (cellulose-based and polysulfone membranes), we did not observe any significant variation in the concentrations of TNF-sR55, TNF-sR75, IL-6, sP-selectin and vWF of the plasma. Patients dialyzed with polysulfone membranes presented higher basal plasma concentrations of sP-selectin and significant postdialysis increase of plasma concentrations of CD23 molecule compared to patients dialyzed with cuprophane dialyzers.

Rapidly progressive antineutrophil cytoplasm antibodies associated with pulmonary-renal syndrome in a 10-year-old girl

CONTEXT

The term pulmonary-renal syndrome has been used frequently to describe the clinical manifestations of a great number of diseases in which pulmonary hemorrhage and glomerulonephritis coexist. The classic example of this type of vasculitis is Goodpasturés syndrome, a term used to describe the association of pulmonary hemorrhage, glomerulonephritis and the presence of circulating antiglomerular basement membrane antibodies (anti-GBM). Among the several types of systemic vasculitides that can present clinical manifestations of the pulmonary-renal syndrome, we focus the discussion on two types more frequently associated with antineutrophil cytoplasm antibodies (ANCA), microscopic polyangiitis and Wegener's granulomatosis, concerning a 10 year old girl with clinical signs and symptoms of pulmonary-renal syndrome, with positive ANCA and rapidly progressive evolution.

CASE REPORT

We describe the case of a 10-year-old girl referred to our hospital for evaluation of profound anemia detected in a primary health center. Five days before entry she had experienced malaise, pallor and began to cough up blood-tinged sputum that was at first attributed to dental bleeding. She was admitted to the infirmary with hemoglobin = 4 mg/dL, hematocrit = 14 %, platelets = 260,000, white blood cells = 8300, 74 % segmented, 4 % eosinophils, 19 % lymphocytes and 3 % monocytes. Radiographs of the chest revealed bilateral diffuse interstitial alveolar infiltrates. There was progressive worsening of cough and respiratory distress during the admission day, when she began to cough up large quantities of blood and hematuria was noted. There was rapid and progressive loss of renal function and massive lung hemorrhage. The antineutrophil cytoplasm antibody (ANCA) test with antigen specificity for myeloperoxidase (anti-MPO) was positive and the circulating anti-GBM showed an indeterminate result.

Proliferating cell nuclear antigen labelling index in localised pigmented villo-nodular synovitis and its relationship to the size of nodules

Proliferating cell nuclear antigen (PCNA) is one of the cell cycle-related proteins directly involved in DNA synthesis. It is a marker of cellular proliferation and has been shown to correlate with ploidy and proliferative activity of cells. Its expression has been used to estimate the growth fraction of human cancer and its prognostic value. Pigmented villo-nodular synovitis (PVNS) is characterised by a nodular lesion in the paratendinous synovial tissue or, less frequently, in a joint. Whether PVNS is a neoplastic or inflammatory lesion remains controversial. We have studied immunohistochemical PCNA expression with pc10 monoclonal antibody in 16 paraffin sections, in 16 cases of localised PVNS, or giant cell tumour of tendon sheath. We have found significant correlation between the size of the lesions and PCNA-LI (labelling index).

Oxidizing side of the cyanobacterial photosystem I. Evidence for interaction between the electron donor proteins and a luminal surface helix of the PsaB subunit

Photosystem I (PSI) interacts with plastocyanin or cytochrome c6 on the luminal side. To identify sites of interaction between plastocyanin/cytochrome c6 and the PSI core, site-directed mutations were generated in the luminal J loop of the PsaB protein from Synechocystis sp. PCC 6803. The eight mutant strains differed in their photoautotrophic growth. Western blotting with subunit-specific antibodies indicated that the mutations affected the PSI level in the thylakoid membranes. PSI proteins could not be detected in the S600R/G601C/N602I, N609K/S610C/T611I, and M614I/G615C/W616A mutant membranes. The other mutant strains contained different levels of PSI proteins. Among the mutant strains that contained PSI proteins, the H595C/L596I, Q627H/L628C/I629S, and N638C/N639S mutants showed similar levels of PSI-mediated electron transfer activity when either cytochrome c6 or an artificial electron donor was used. In contrast, cytochrome c6 could not function as an electron donor to the W622C/A623R mutant, even though the PSI activity mediated by an artificial electron donor was detected in this mutant. Thus, the W622C/A623R mutation affected the interaction of the PSI complex with cytochrome c6. Biotin-maleimide modification of the mutant PSI complexes indicated that His-595, Trp-622, Leu-628, Tyr-632, and Asn-638 in wild-type PsaB may be exposed on the surface of the PSI complex. The results presented here demonstrate the role of an extramembrane loop of a PSI core protein in the interaction with soluble electron donor proteins.

Bilateral acetabular fracture without trauma

In the absence of trauma fracture of the acetabulum is an extremely rare injury. We describe a 70 year old man who spontaneously developed fractures in both acetabulae due to bony insufficiency. It was successfully treated by bilateral total hip replacement.

Neopterin in tuberculous and neoplastic pleural fluids

Neopterin is derived from guanosine-triphosphate, produced by stimulated macrophages under the influence of gamma interferon of lymphocyte origin. It has been suggested as an excellent marker for activation of the monocyte/macrophage axis in some clinical situations. We evaluated its concentration in the pleural effusions of 25 individuals (10 tuberculous and 15 neoplastic) as well as in the blood of 22 of them (8 tuberculous and 14 neoplastic), comparing these levels with those of a control group in 99 normal individuals. The concentration of neopterin was determined by radioimmunologic assay. This showed a significant increase (p less than 0.001) of neopterin levels in the tuberculous pleural fluid, compared to the neoplastic group (42 +/- 23/17 +/- 9 nmol/L). In the blood, values were nearly identical to the pleural fluid (41.3 +/- 25/15.8 +/- 6.9 nmol/L), although with significant differences between them and in relation to the control group (p less than 0.001), which had a normal serum value (5.11 +/- 1.92 nmol/L). We emphasize the influence of the neopterin levels in the pleural fluid on the diagnosis of causes of pleurisy and its importance as a marker of immunologic cellular activity.

Circumscribed spontaneous heterotopic ossification in the soft tissues simulating sarcoma

Eight cases are described of circumscribed heterotopic ossification in the soft tissues characterised by spontaneous onset, no history of trauma, and rapid course which have frequently led to a mistaken preoperative diagnosis of highly malignant tumour. The terminology differentiates it from myositis ossificans, which is a different entity. The authors emphasize the need for accurate evaluation of all the clinical and radiographic data in order to avoid an erroneous diagnosis of extraosseous osteogenic sarcoma or parosteal osteogenic sarcoma. In this regard, both radiography and histological examination demonstrate the so-called zoning pattern, namely a radiolucent central zone corresponding to the more immature area and consisting of fibrous tissue with active histiofibroblastic proliferations and a radiopaque peripheral area, where ossification is more mature the closer it gets to the periphery. Histological specimens obtained exclusively from the central area may lead even the most expert pathologists to a diagnosis of fibrosarcoma or osteogenic sarcoma. Finally, the pathogenetic aspects of the anomaly are discussed, as well as those concerned with the differential diagnosis from other types of heterotopic ossification.

Experimentally induced synovial sarcoma

Synovial sarcoma has been induced in the knee joints of rats by intra-articular injection of 9-10-dimethyl-1-2-benzanthracene. Tumours developed from three to six months after the last injection. The neoplasms obtained were classified as synovial sarcoma (50%), fibrosarcoma (25%), giant cell sarcoma (15%), malignant fibrous histiocytoma (10%). The synovial membrane in the treated knee joints presented a chronic synovitis associated with fibrosis and proliferation of the lining cells. The primitive tumour spread locally infiltrating muscle and the adjacent bones. Metastases occurred most frequently to the lungs (70%) and liver (20%); lymph nodes were involved in 10%.