Effect of accelerated electron beam on mechanical properties of human cortical bone: influence of different processing methods.

Accelerated electron beam (EB) irradiation has been a sufficient method used for sterilisation of human tissue grafts for many years in a number of tissue banks. Accelerated EB, in contrast to more often used gamma photons, is a form of ionizing radiation that is characterized by lower penetration, however it is more effective in producing ionisation and to reach the same level of sterility, the exposition time of irradiated product is shorter. There are several factors, including dose and temperature of irradiation, processing conditions, as well as source of irradiation that may influence mechanical properties of a bone graft. The purpose of this study was to evaluate the effect e-beam irradiation with doses of 25 or 35 kGy, performed on dry ice or at ambient temperature, on mechanical properties of non-defatted or defatted compact bone grafts. Left and right femurs from six male cadaveric donors, aged from 46 to 54 years, were transversely cut into slices of 10 mm height, parallel to the longitudinal axis of the bone. Compact bone rings were assigned to the eight experimental groups according to the different processing method (defatted or non-defatted), as well as e-beam irradiation dose (25 or 35 kGy) and temperature conditions of irradiation (ambient temperature or dry ice). Axial compression testing was performed with a material testing machine. Results obtained for elastic and plastic regions of stress-strain curves examined by univariate analysis are described. Based on multivariate analysis, including all groups, it was found that temperature of e-beam irradiation and defatting had no consistent significant effect on evaluated mechanical parameters of compact bone rings. In contrast, irradiation with both doses significantly decreased the ultimate strain and its derivative toughness, while not affecting the ultimate stress (bone strength). As no deterioration of mechanical properties was observed in the elastic region, the reduction of the energy absorption capacity of irradiated bone rings apparently resulted from changes generated by irradiation within the plastic strain region.

Effect of gamma irradiation on mechanical properties of human cortical bone: influence of different processing methods.

The secondary sterilisation by irradiation reduces the risk of infectious disease transmission with tissue allografts. Achieving sterility of bone tissue grafts compromises its biomechanical properties. There are several factors, including dose and temperature of irradiation, as well as processing conditions, that may influence mechanical properties of a bone graft. The purpose of this study was to evaluate the effect of gamma irradiation with doses of 25 or 35 kGy, performed on dry ice or at ambient temperature, on mechanical properties of non-defatted or defatted compact bone grafts. Left and right femurs from six male cadaveric donors aged from 46 to 54 years, were transversely cut into slices of 10 mm height, parallel to the longitudinal axis of the bone. Compact bone rings were assigned to the eight experimental groups according to the different processing method (defatted or non-defatted), as well as gamma irradiation dose (25 or 35 kGy) and temperature conditions of irradiation (ambient temperature or dry ice). Axial compression testing was performed with a material testing machine. Results obtained for elastic and plastic regions of stress-strain curves examined by univariate analysis are described. Based on multivariate analysis it was found that defatting of bone rings had no significant effect on any mechanical parameter studied, whereas irradiation with both doses decreased significantly the ultimate strain and its derivative toughness. The elastic limit and resilience were significantly increased by irradiation with the dose 25 kGy, but not 35 kGy, when the time of irradiation was longer. Additionally, irradiation at ambient temperature decreased maximum load, elastic limit, resilience, and ultimate stress. As strain in the elastic region was not affected, decreased elastic limit resulted in lower resilience. The opposite phenomenon was observed in the plastic region, where in spite of the lower ultimate stress, the toughness was increased due to the increase in the ultimate strain. The results of our study suggest that there may be an association between mechanical properties of bone tissue grafts and the damage process of collagen structure during gamma irradiation. This collagen damage in cortical bone allografts containing water does not depends on the temperature of irradiation or defatting during processing if dose of gamma irradiation does not exceed 35 kGy.

Time efficiency of direct anterior hip arthroplasty compared to postero-lateral approach in elderly patients.

INTRODUCTION: Primary arthroplasty of the hip joint is currently one of the most commonly performed procedures in orthopedics. In Poland we are observing significant changes in the age structure. With the prolonged life more and more elderly patients require musculoskeletal surgery to maintain comfortable and painless mobility. Reducing the duration of the procedure reduces the costs of anesthesiology, surgical and instrument teams, as well as the operating room technical team. The aim of the study was to compare the time required to perform hip joint arthroplasty by the direct anterior approach (DAA) with the postero-lateral approach (PLA) in our hospital. MATERIAL AND METHODS: A retrospective analysis of 559 total and bipolar cemented and cementless hip replacement procedures based on two operative approaches - the minimally invasive DAA over the course of 2 years, and the standard PLA over the course of 3 years - was performed. RESULTS: Statistically significant differences were observed between the approaches used for cementless total arthroplasty with regard to the mean treatment times: 51.9 min for the 272 DAA cases, and 78.3 min for the 190 PLA cases (p < 0.0001). For the cementless hemi-arthroplasty procedure, the mean treatment times were 46.9 min in 36 patients for DAA, and 48.2 min for 61 patients for PLA (p = 0.57). CONCLUSIONS: Minimally invasive DAA significantly shortens the time of the procedure in elderly patients compared to PLA. Further study is needed to analyze other aspects of those two approaches.

Is it possible to use standard electrocardiography for risk assessment of patients with pulmonary embolism?

BACKGROUND: Risk stratification of patients with acute pulmonary embolism (APE) is crucial for appropriate treatment selection. Shock and hypotonia are known indications for aggressive management. However, in the haemodynamically stable group the best prognosis strategy is still being sought. Acute pulmonary embolism often provokes changes in electrocardiography recordings (ECG). AIM: To assess whether ECG features recorded on admission can be useful for risk stratification during hospitalisation. METHODS: We analysed 12-lead ECG and echocardiography of 56 patients (22 males, age: 64.3 +/- 17.9 years) with diagnosed APE. The diagnosis of APE was confirmed by spiral computer tomography. The ECG analysis was based on the 21-point ECG score including: the presence of tachycardia (> 100 beats/min), right bundle branch block, negative S waves in lead I, negative Q or T waves in lead III, S1Q3T3 complex and depth of negative T waves in leads V1-V4. ECG features were scored from 0 to 21 points. Complicated in-hospital course was defined as need for vasopressor, thrombolysis, embolectomy or resuscitation and the presence of shock index > 1 (heart rate/systolic blood pressure). RESULTS: Four (7.1%) patients died during hospitalisation and in 8 (14.3%) others complications occurred. Patients with complications had higher mean sum of 21-ECG score compared to subjects with uneventful course [8 (1-17) vs. 3 (0-18); p = 0.04]. Right ventricular contractility dysfunction (RVD) in echocardiography was found in 13 (23.2%) patients, who had higher ECG score compared to patients without RVD [8 (3-17) vs. 2 (0-18); p = 0.004]. The area under the ROC curve to assess the usefulness of 21-ECG score to predict RVD was 0.794 (95% CI 0.665-0.891) and for PPH 0.727 (95% CI 0.591-0.837). The sensitivity and specificity, positive and negative predictive value for the value > 3 points in 21-ECG score to predict RVD were: 92, 65, 44, 97% and for PPH: 75, 46, 19, 92%, respectively. CONCLUSIONS: 21-ECG score is a simple and cheap method which can be used to predict RVD and serious complications in patients with APE. A value L 3 points in the 21-ECG score can exclude RVD with high probability and limit the need of echocardiography to 23% of haemodynamically stable patients.

[Diagnostic techniques in breast cancer detection. Part II: Physical and biopsy methods]. / Techniki diagnostyczne w raku piersi. Czesc II: Metody fizyczne i biopsyjne.

This publication contains an overview of methods based on the principles of physics applied in breast cancer diagnosis. It refers both to those created de novo and those that have recently been updated, thanks to the revolutionary progress in digital, computer and information technologies. It also contains an overview of the biopsy techniques considered to be "the golden standard" in breast cancer diagnoses, as well as the latest ones, allowing to obtain ductal cells. An effort to develop new diagnostic methods, based on various fields of physics and integration of various diagnostic methods, needs to be made in order for medicine to cope with the requirements of early detection of breast tumours.

[Diagnostic techniques in breast cancer detection. Part III. The new cytobiological methods]. / Techniki diagnostyczne w raku piersi. Czesc III: Nowe metody biologiczne i genetyczne.

This publication contains an overview of the cyto-biological technologies utilized in breast cancer diagnosis. It refers to technologies created de novo and heralded as a breakthrough ones, as well as to those existing for years. An integration of new diagnostic biogenetic methods, with imaging techniques such as mammography, have become essential in order to cope with the requirements of early detection of breast tumours. Apart from the new and innovative diagnostic techniques, this publication also presents an outline of recommendations for genetic diagnostics as well as cooperative and multidisciplinary integrative activities, which are prerequisites for successful diagnosis and treatment and, consequently, longer survival periods upon which patients rely.

[Diagnostic techniques in breast cancer detection. Part I: imaging methods and their modifications]. / Techniki diagnostyczne w raku piersi. Czqsc I: Metody obrazowe i ich modyfikacje.

This publication contains an overview of the imaging techniques and the related technologies utilized in breast cancer diagnosis. It describes both those known for tens of years as well as the ones developed recently thanks to the new technological developments. An integration and coexistence of the diagnostic methods from classical mammography to the computerized laser mammography has become essential in order to cope with the requirements of early detection of breast tumours, which is a precondition of successful treatment and longer survival periods upon which patients rely.

Functionalized mesoporous silica thin films as a tunable nonlinear optical material.

The article is about a novel material for application in optoelectronic devices: mesoporous silica in the form of thin films with vertically aligned channels containing anchored propyl-copper-phosphonate functional groups. We described a synthesis route and carried out characterization of the structure to obtain its nonlinear optical (NLO) properties (second and third order harmonic generation). A quasi phase transition was found in the material resulting from modification of the functional group content. We also demonstrated that it is possible to modify NLO susceptibilities by tuning the distance between active polar units.

Assessment of head gunshot wounds by means of post-mortem computed tomography in exhumed anonymous cadaver.

Autopsy of corpses with advanced post-mortem changes is the most challenging aspect of medico-legal activities. In many cases, owing to soft tissue decomposition, making a final diagnosis as to the mechanism and cause of death is very difficult, and sometimes impossible (Carcione P, Argo G, Pincone D, Zgo S, Scopelliti L, Sortino C, Procaccianti P. Role of MCT vitropsy in evaluation of burned bodies and its comparison with traditional autopsy. Poster No.: C-1156, ECR 2014, Scientific exhibit). In such cases, the diagnostic process can be supported by post-mortem CT imaging. Post-mortem multislice CT imaging used in the field of forensic medicine is widely reported to be a good method for visualizing injuries and natural pathologies; however, only a limited number of forensic departments use this method in everyday practice. This method enables accurate assessment of bony injuries (fracture type, degree of bone displacement); has the ability to detect radiopaque foreign bodies, most frequently fragments of bullets; and in some cases enables soft tissue delineation (Hardy K. CT autopsy. Radiology Today 2008; 9: 20. Available from: http://www.radiologytoday.net/archive/rt01282008p20.shtml). In cadavers with advanced post-mortem changes, it is extremely difficult to retrieve the whole bullet or its parts. Owing to decomposition and reduced cohesion of the tissues, standard autopsy preparation techniques are impossible to perform. Post-mortem changes may also cause displacement of the bullet within the body in the long term, as well as at the time of transport following exhumation (Maiese A, Gitto L, De Matteis A, Panebianco V, Bolino G. Post mortem computed tomography: useful or unnecessary in gunshot wounds deaths? Two case reports. Leg Med (Tokyo) 2014; 16: 357-63). It is therefore important to perform post-mortem CT imaging directly after extraction of corpses in a similar position to how the dead body was exhumed. Interpretation of the images requires cooperation of forensic medicine specialists and radiologists to correlate radiological findings with autopsy.

Can diagnostic ultrasound scanners be a potential vector of opportunistic bacterial infection?

UNLABELLED: Ultrasound examinations are recognised as being safe. The greatest epidemiological threat during the performance of examination is the transfer of pathogenic and opportunistic microorganisms between patients and from personnel to patients. Colonization of the skin with opportunistic bacteria of immunocompromised and high risk patients may lead to infection following an ultrasound scan. AIM: To identify and evaluate the strains of bacteria occurring on ultrasound equipment subjected to unexpected control performed by a local infectious diseases control team. We assumed that transducers, gel holders and gel bottles can be contaminated with normal human skin microflora. The remaining tested parts of the ultrasound equipment could possibly be contaminated with normal human skin microflora and other pathogens. MATERIAL AND METHODS: The swabs were taken from ultrasound scanners located in various hospital settings, from out-patient based radiology scanning rooms to operating theatre, and cultured. RESULTS: Among all isolated 23% strains were classified as environmental microflora; 8% as strains related to patient's skin contamination; and 13 % strains constituted pathogenic Gram-negative rods.. The remaining strains were classified as opportunistic flora 38%. High prevalence of opportunistic bacteria cultured in our study lead to the modification of the ultrasound cleaning procedures in both institutions and recommendation of the use of antibacterial wipes to clean all parts of ultrasound equipment in contact with patients' skin and examiners. CONCLUSIONS: Contamination not only affects parts of diagnostic equipment placed in direct contact with the patient, but also, those surfaces that only medical personnel have had contact with.

[Doppler ultrasound assessment of blood flow parameters in hemodialysis fistulas]. / Dopplerowska ocena parametrów przeplywu krwi w przetokach dializacyjnych.

UNLABELLED: The number of patients requiring kidney replacement therapy is systematically increasing world wide. At the end of 2000 there were 8424 treated with dialysis in Poland. Ultrasound examinations allow assessment of dialysis fistula morphology and function. OBJECTIVE: Assessment of blood flow parameters in hemodialysis fistulas. Assessment of correlation between the analysed parameters. Optimization of number of parameters needed to characterise blood flow in dialysis fistulas. MATERIAL AND METHODS: Doppler ultrasound examinations were performed in 86 patients with hemodialysis fistulas. Various blood flow parameters were analysed. RESULTS: In analysed group a following values of analysed parameters were recorded: brachial artery cross sectional area was within the range 0.28-0.78 cm2; radial artery 0.05 - 0.39 cm2. The resistance and pulsatility index (RI and PI) of brachial artery were 0.32-1.00 and 0.39-3.56 respectively. Mean blood flow through brachial artery was 1082.3 ml/min and 946 ml/min through dialysis fistulas. CONCLUSIONS: Almost full correlation was found between volume of blood flowing through dialysis fistula and brachial artery, brachial and radial arteries and between PI and RI. The volume of blood flowing through brachial artery depends mostly on brachial artery cross section area and mean blood flow velocity. In patients with dialysis fistulas located on the arm or forearm blood flow measurements may be performed within the brachial artery.

Neutrophil gelatinase-associated lipocalin, cystatin C and eGFR indicate acute kidney injury and predict prognosis of patients with acute pulmonary embolism.

OBJECTIVE: Risk stratification in acute pulmonary embolism (APE) includes the assessment of clinical status, right ventricular dysfunction and troponin concentrations. Since acute renal impairment is one of the important predictors of mortality in cardiovascular diseases, the authors hypothesised that it is an independent mortality marker in APE. MATERIAL AND METHODS: The authors observed 142 consecutive patients (52 M/90 F, 64±18 years) with APE diagnosed with contrast enhanced multislice CT. On admission, blood samples were collected for neutrophil gelatinase-associated lipocalin (N-GAL), cystatin C and creatinine assays. Estimated glomerular filtration rate (eGFR) was calculated using MDRD formula. RESULTS: Fourteen (10%) of 142 patients died by the 30th day of observation. eGFR≤60 ml/min was noted in 68 (48%) patients and eGFR≤30 ml/min in 11 (8%) patients. eGFR was higher in survivors than in non-survivors (66 (17-169) vs 46 (10-119) ml/min, respectively, p=0.02). In 80 (56%) patients, N-GAL was >50 ng/ml indicating acute kidney injury. N-GAL was higher in non-survivors than in survivors (88.8 (28.4-200.0) vs 53.0 (7.1-200.0) ng/ml, p<0.01). N-GAL level >50 ng/ml was found in 11 (79%) patients with fatal outcome. Area under the curve of N-GAL for all-cause mortality in ROC analysis was 0.715. N-GAL>75 ng/ml was present in 44 (31%) patients, while cystatin C >1900 ng/ml in 14 (10%) subjects. They showed sensitivity, specificity, positive predictive value and negative predictive value for prediction of all-cause death ((64%, 73%, 21%, 95%) and (36%, 91%, 30% 93%), respectively). N-GAL>75 ng/ml and cystatin C>1900 ng/ml increased the risk of death (HR 4.4 (95% CI 1.48 to 13.2, p<0.01) and 4.7 (95% CI 1.56 to 13.9, p=0.01), respectively). CONCLUSIONS: Acute kidney injury assessed by N-GAL occurs in 30% of APE and may contribute to the impairment of renal function present in half of them. Moreover, N-GAL, cystatin C elevation and low eGFR are associated with a poor 30-day prognosis in APE.