Effect of tranexamic acid on fracture healing in rats / Efeito do ácido tranexâmico na cura de fratura em ratos

ABSTRACT Introduction In this study we investigated the effect of tranexamic acid (TXA) on fracture healing in an established animal model, when used to stop bleeding in orthopedic trauma surgery. Materials and Methods This study was a randomized, controlled, laboratory study. Eighteen Sprague-Dawley rats were randomly assigned to three groups, either receiving TXA intravenously (Group 1), TXA topically (Group 2), or isotonic TXA intravenously and TXA topically in the same amounts for the control group (Group 3). First, a Kirschner wire was inserted retrogradely into the femoral intramedullary canal. Then the femurs were fractured at the midshaft region with blunt guillotine. After 4 weeks, the rats were sacrified and the femurs harvested. Cortical bone volume, callus volume, and bone mineral density were calculated using computer tomography scans. Torsion tests were performed. Groups were compared by maximum torque to failure and callus stiffness. Results There were no statistical differences in torque to failure and stiffness between the 3 groups. There were no differences in mean total bone volume, callus volume, percent bone volume, or callus density between the groups. Conclusions A single dose of topical or intravenous TXA has no negative effect on fracture healing when used in traumatic femur fracture surgery in an animal model. Evidence level II; Randomized controlled experimental study.

RESUMO Introdução Neste estudo, investigamos o efeito do ácido tranexâmico (TXA) sobre a consolidação de fraturas em um modelo animal estabelecido, quando é usado para estancar o sangramento em cirurgias de trauma ortopédico. Materiais e Métodos Trata-se de estudo de laboratório randomizado e controlado. Dezoito ratos Sprague-Dawley foram atribuídos randomicamente em três grupos, que receberam TXA por via intravenosa (Grupo 1), TXA tópico (Grupo 2) ou isotônico por via intravenosa e tópico na mesma quantidade como grupo controle (Grupo 3). Primeiro, foi inserido um fio de Kirschner por via retrógrada no canal intramedular femoral. Em seguida, o fêmur dos animais foi fraturado na região média do corpo do fêmur com guilhotina romba. Depois de quatro semanas, os ratos foram sacrificados e os fêmures foram retirados. O volume do osso cortical, o volume do calo e a densidade mineral óssea foram calculados por meio de tomografia computadorizada e foram realizados testes de torção. Os grupos foram comparados de acordo com o torque máximo até a falha e a rigidez do calo. Resultados Não houve diferença estatística no torque até a falha e rigidez entre os três grupos nem diferenças entre os grupos quanto ao volume médio total do osso, volume e densidade do calo e percentual de volume ósseo. Conclusões Uma dose única de TXA tópico ou intravenoso não tem efeito negativo sobre a consolidação da fratura quando usada em cirurgia de fratura traumática de fêmur em modelo animal. Nível de evidência II; Estudo experimental controlado randomizado.

Effect of N and NPK fertilizers on early field performance of narrow-leaved ash, Fraxinus angustifolia.

The effect of fertilization in the first growing season on early survival and growth of narrow-leaved ash (NLA) (Fraxinus angustifolia ssp. oxycarpa) was evaluated throughout the first 3 years of growth in Adapazari, Turkey. A randomized complete block design with four replications was established to investigate fertilization effects. Granular N urea [46%, (NH2 )2CO, NH2-N] and NPK (15/15/15%; NH3-N, P2O5, K2O) fertilizers were applied in mid-May of the first growing season. Fertilization treatments per tree were control, 67 g NPK (equal to 10/10/10 g N/P2O5 /K2O tree–1), 133 g NPK (20/20/20 g N/P2O5 /K2O tree–1), 33 g urea N (15 g N tree–1) and 54 g urea N (25 g N tree–1). After three growing seasons under these fertilizer treatments, 98% of trees were still viable. Compared to the control treatment, fertilization had a large and positive effect on diameter and height growth during the first 3 years of growth. However, since there were no significant differences among the fertilized plots in terms of tree diameter and height growth, addition of P and K to the fertilizer regime was not beneficial. The results show that N fertilization in the first growing season has the potential to improve early field growth of narrow-leaved ash.

Soil respiration and root biomass responses to burning in calabrian pine (Pinus brutia) stands in Edirne, Turkey.

In this study, soil properties and root biomass responses to prescribed fire were investigated in 25-30 year-old calabrian pine (Pinus brutia Ten.) stands in Edirne, Turkey. The stands were established by planting and were subjected to prescribed burning in July, 2005. Soil respiration rates were determined every two months using the soda-lime method over a two-year period. Fine (>2 mm diameter) and small root (>2-5 mm diameter) biomass were sampled approximately bimonthly using the sequential coring method. Soil respiration rates in burned sites were significantly higher than in control sites during the summer season but there was no significant difference in the other seasons. Soil respiration rates were correlated significantly with soil moisture and soil temperature. Fine and small root biomass were significantly lower in burned sites than in control sites. Mean fine root biomass values were 3204 kg ha-1 for burned and 3772 kg ha-1 for control sites. Annual soil CO2 releases totaled 515 g C m-2 for burned and 418 g C m-2 for control sites. Our results indicate that, depending on site conditions, fire could be used successfully as a tool in the management of calabrian pine stands in the study area.

Evaluating the seasonal changes of some water quality parameters of the Buyuk Melen River Basin (Duzce, Turkey).

In this study, some heavy metal concentrations (Pb, Zn, Fe, Cr, Cu), suspended sediment, chemical oxygen demand (COD), biological oxygen demand (BOD), cyanide, phenol, fecal coliform and total coliform water parameters were determined in the streams (Kucuk Melen, Asarsuyu, Ugursuyu, Buyuk Melen and Aksu) of Buyuk Melen Watershed that provides drinking water to Istanbul in Western Black Sea Region of Turkey. Measurements of water quality parameters were done monthly in eleven separate stations (4 in Kucuk Melen Stream, 1 in Asarsuyu Stream, 1 in Ugur Stream, 1 in Aksu Stream and 4 in Buyuk Melen Stream) from August 2001 to August 2002. The seasonal changes in water quality parameters were evaluated statistically. The results, the parameters, COD, BOD, Pb, Zn, Fe, Cr, Cu, cyanide, fecal coliform, total coliform and suspended sediment showed significant differences among seasons and streams (ANOVA; P <0.05). According to Turkish Standarts (TS) 266, European Union (EU) and World Health Organization (WHO) criteria, the maximum values of each parameter in streams within the Buyuk Melen watershed are recorded and evaluated in this study.

Evaluating the seasonal changes of water quality of the Değirmendere and Galyan Rivers (Trabzon, Turkey).

The Değirmendere and Galyan (Değirmendere tributary) Rivers that discharge their water into the Black Sea are important watersheds in the northeastern part of Turkey. Water quality parameters were sampled from 1997 through 2001 for each year at five sites (three for Galyan, two for Degirmendere) along 29 and 42 km gradients, respectively covering all seasons. Surface water was collected from the sites and analyzed for temperature, total alkaline (MAAL), total dissolved solids (TDS), dissolved oxygen (DO), pH, conductivity (EC), nitrate (NO3), nitrite (NO2), total hardness (TH), phenolphthalein alkalinities (PAL) and organic matter (PV). Seasonal changes of water quality were analyzed statistically for both Rivers and evaluated according to the TS 266, EU and WHO standards. The analysis of variance results showed that Ca, Mg, MAL, NO3, pH, TDS and TH parameters of the Değirmendere River and Ca, DO, EC, MAL, NO3, pH and TH parameters of the Galyan River showed seasonal differences (p<0.05). The maximum values of the water pollution parameters for the two Rivers were below the threshold values throughout the study period. When both Rivers were compared, the mean values of the pollution parameters of the Degirmendere River were higher than those of the Galyan River and very close the limits. The results indicate that both Rivers can be used for the production of potable water during all seasons but only with an advanced treatment in the Değirmendere and a moderate treatment in the Galyan River, and for indirect and non-contact recreational activities.