Complex Material and Surface Analysis of Anterolateral Distal Tibial Plate of 1.4441 Steel

Nickel-based austenitic stainless steels are still common for manufacture of implants intended for acute hard tissue reinforcement or stabilization, but the risk of negative reactions due to soluble nickel-rich corrosion products must be considered seriously. Corrosion processes may even be accelerated by the evolution of microstructure caused by excessive heat during machining, etc. Therefore, this study also deals with the investigation of microstructure and microhardness changes near the threaded holes of the anterolateral distal tibial plate containing approx. 14wt.% Ni by composition. There were only insignificant changes of microhardness, grain size, or microstructure orientation found close to the area of machining. In addition, wettability measurements of surface energy demonstrated only minor differences for bulk material and areas close to machining. The cyclic potentiodynamic polarization tests were performed in isotonic physiological solution. The first cycle was used for the determination of corrosion characteristics of the implant after chemical passivation, the second cycle was used to simulate real material behavior under the condition of previous surface damage by excessive pitting corrosion occurring during previous polarization. It was found that the damaged and spontaneously repassived surface showed a three-time higher standard corrosion rate than the “as received” chemically passivated surface. One may conclude that previous surface damage may decrease the lifetime of the implant significantly and increase the amount of nickel-based corrosion products distributed into surrounding tissues.

Additives Incorporated in Cellulose Acetate Membranes to Improve Its Performance as a Barrier in Periodontal Treatment

In this study, we prepared cellulose acetate membranes, by means of casting mold, incorporated with two additives, sodium carboxymethyl lignin and calcium glycerophosphate, in order to improve properties for periodontal applications. The membranes were characterized from the morphological, structural, thermal and mechanical point of view, as well as by physiological pH tests. The results showed that membranes with additives improve the physical-chemical and mechanical properties, especially when the two additives are present in the same membrane, which can be attributed to the important synergy between them. The most significant effects occur in increasing the thickness and decreasing the density, which reflects in the porosity of the membranes, although the added amounts do not exceed 1.4%. A 1% increase in lignin concentration does not change the thickness and density of the membrane, but that amount of lignin plus 0.4% calcium glycerophosphate increases the thickness of the membrane by 42% and decreases the density by about 6%. Although there is a decrease in mechanical properties, as observed in Young's modulus and crystallinity, the significant and intermittent increase in sample weight loss with both additives in physiological solution indicates that, in the long run, it can be used as a degradable barrier.

Reactivity and Corrosion Behaviors of Ti6Al4V Alloy Implant Biomaterial under Metabolic Perturbation Conditions in Physiological Solutions

The corrosion of implant biomaterials is a well-known critical issue when they are in contact with biological fluids. Therefore, the reactivity of Ti6Al4V implant biomaterials is monitored during immersion in a Hanks’ physiological solution without and with added metabolic compounds, such as lactic acid, hydrogen peroxide, and a mixture of the two. Electrochemical characterization is done by measuring the open circuit potential and electrochemical impedance spectroscopy performed at different intervals of time. Electrochemical results were completed by morphological and compositional analyses as well as X-ray diffraction before and after immersion in these solutions. The results indicate a strong effect from the inflammatory product and the synergistic effect of the metabolic lactic acid and hydrogen peroxide inflammatory compound on the reactivity and corrosion resistance of an implant titanium alloy.

Effectiveness and success rates of endoscopic third ventriculostomy in patients under 2 years old

Objective: Endoscopic third ventriculostomy (ETV) stands out as an important option in the treatment of hydrocephalus without shunts. Endoscopic third ventriculostomy (ETV) has become more popular due to recent technical developments in endoscopic systems. But the urge of the physician, to provide a shuntfree survival for his patients, leads to performing the procedure in a unsuitable group of patients. Compared with shunt surgery, ETV presents a more physiological solution for the treatment of hydrocephalus. ETV is accepted as the first-line treatment method in many centers in appropriate cases in the treatment of obstructive hydrocephalus. The aim of this study is to examine the results of patients under the age of two underwent endoscopic third ventriculostomy. Methods: 79 patients who underwent ETV between 2011 and 2020 in our clinic and who were under 2 years of age at the time of operation were retrospectively analyzed. Results: 45 of 79 patients were male babies and 34 were female babies. The average age of the patients is 7 months (1 day - 22 months). In 39 (49.3%) patients, there was no need for repeat surgery in their follow-up after ETV. ETV procedure was repeated in 5 (6.3%) patients, and ventriluloperitoneal shunt (VPS) surgery was performed in 2 (2.5%) patients. In 13 patients, ventriculoperitoneal shunt was applied from the anterior and presented with shunt dysfunction. VPS surgery was not performed again after ETV in 3 (23%) of 13 patients after ETV. Conclusions: ETV can also be applied to patients younger than two years of age, and this treatment can give patients the chance to live a life independent of shunt.

Possibilities of clinical application of nano-crystal hydroxyapatyte in treatment of purulent-inflammatory diseases

Objective. To investigate the impact of the sorbtion-aspiration drainage system on background of hydroxyapatite and zinc oxide on experimental peritonitis. Materials and methods. The experiment was performed on 55 white laboratory rat males, ageing 2 - 3 mo, with the body mass 225 - 250 g, which were kept in the typical vivarium conditions. Suspension of E. coli in physiological solution, 1.0 - 1.5 ml in concentration 1010 , was used for the peritoneum contamination. The suspension was introduced into abdominal cavity in the dose, dependent on the animal body mass, using the syringe for insulin injection. Peritonitis in the rats was developed in 48 h and characterized by intoxication, which exaggerated rapidly, as well as by intestinal motor disorders and pronounced microcirculatory disturbances. The experimental animals were distributed into 5 Groups. In patients of Group I the interventions were not performed (control); in laboratory animals of Group II peritonitis was not simulated, but the abdominal cavity was drained, using the sorption-aspiration drainage system; in laboratory animals of Group III peritonitis was simulated; in the Group IV of laboratory animals on background of peritonitis the abdominal cavity was drained, using the sorption-aspiration drainage system; in the Group V animals the abdominal cavity was drained by a standard silicon drain on background of peritonitis. Results. Reduction of abdominal contamination by 43.12% and of histological features were produced in abdominal organs under the influence of the composite system, witnessing its bactericidal and sorption-antiinflammatory action. Conclusion. Experimentally there was confirmed the possibility of application of sorption-aspiration drainage system on background of hydroxyapatite and zinc oxide in treatment of an acute peritonitis.

Diastolic disorder inherent to doxorubicin cardiotoxicity

Background: The doxorubicin (Dx) cardiotoxicity is manifested by a marked heart failure evolution. The impact of Dx on lusitrop functions of the heart and the inherent diastolic disorders have a theoretical and practical value for the connection cardiology-oncology. Material and methods: Dx cardiotoxicity was reproduced by its administration i/p in white rats in cumulative dose 16 mg/kg (Dx group n=9). Control group (n=9) received only physiological solution. The study was performed in vitro by using models of isolated heart perfusion in either isovolumic or exterior working regimens. The assayed indices of diastole functioning were: left ventricle (LV) end-diastolic pressure (LVEDP), diastolic stiffness, isovolumic relaxation velocity (-dP/dTmax) and protodiastolic pressure of LV (LVPDP). Results: The indices of diastolic disorders induced by Dx were elevation of LVEDP, diastolic stiffness and LVPDP in a range of 97-168% comparing to control as well as diminution of -dP/dTmax in the physiological pattern of hemodynamics. LVEDP increased more in conditions of calcium overloading or endothelin-1 (ET-1) action that are involved in pathogenesis of diastolic rigidity. Dx action led to decrease of myocardium resistance to ischemiareperfusion action resulting in the LVEDP elevation by 53% comparing to control. Conclusions: 1. Diastolic disorders inherent to Dx cardiotoxicity are manifested by the increase of LVEDP and diastolic stiffness. 2. Diastolic disorders compromised the volume-pressure relationship of LV, the adaptation of the heart to effort with volume, being more pronounced during the action of calcium excess and ET-1

Quando lo squat fa la differenza

The paper presents the case of a 1-year-old girl with severe respiratory distress, perioral cyanosis and severe desaturation (SpO2 35% with oxygen in nasal prongs). An echocardiogram was readily performed showing the distinctive features of Fallot’s tetralogy. The child was placed in a squatting position (knee-chest position). Subcutaneous morphine at a dose of 0.2 mg/kg, bolus of physiological solution in 30 minutes and therapy with oral propanolol were administered, with progressive clinical improvement. Subsequently, corrective cardiac surgery was performed with regular postoperative period and following good clinical conditions. Cardiogenic causes must be considered among the causes of respiratory distress especially in low resource countries where congenital heart disease can be misdiagnosed or diagnosed belatedly.