Lipid peroxidation and generation of hydrogen peroxide in frozen-thawed ram semen supplemented with catalase or Trolox

Semen manipulation and cryopreservation-thaw procedures may accelerate the generation of reactive oxygen species (ROS). Sperm exposure to large amounts of ROS has been shown to cause membrane lipid peroxidation and cellular injury to the sperm. The objective of this study was to overcome the ROS production in frozen-thawed ram semen by the addition of the antioxidants catalase or Trolox to semen following thawing. Frozen-thawed ram semen (100 x 10(6) sperm/straw) was supplemented with PBS (control group), 100 mu g/ml catalase, or 100 mu M Trolox/10(8) sperm (catalase and Trolox being dissolved in PBS) and incubated (37 degrees C) for 5 min. Under the experimental conditions used in this study, the catalase and Trolox antioxidants failed to protect the sperm from the spontaneous production of ROS. However, when lipid peroxidation was induced by iron (FeSO(4)), the addition of Trolox promoted a reduction (P < 0.05) in the formation of TBARS in the semen, compared to the control and catalase semen samples. The generation of TBARS and H(2)O(2) occurred in the extender alone, without the presence of sperm cells. In conclusion, the addition of Trolox to frozen-thawed ram semen could be beneficial as it decreases the production of TBARS when oxidative stress is induced. It is possible that a longer incubation period could lead to different results. The concentration of catalase also needs to be further evaluated. The extender could contribute to the oxidative stress of sperm, as it is a source of ROS during the cryopreservation of semen. (C) 2010 Elsevier B.V. All rights reserved.

Lipid peroxidation and generation of hydrogen peroxide in frozen-thawed ram semen cryopreserved in extenders with antioxidants

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of refrigeration systems upon frozen bull sperm viability assessed by computer-assisted sperm analysis and fluorescent probes

Sperm cryopreservation success depends upon the maintenance of spermatozoa fertility potential. Sperm cells must preserve both integrity and functionality of several cell structures. The stabilization phase must allow the exit of water from the sperm cells via osmosis. This study aimed to compare the effect of refrigeration in the commercial refrigerator (CR) and the transport/refrigeration box (TRB) upon the viability of frozen bull sperm diluted in three different extenders (A, B and C). Ten Nellore bulls, Bos taurus indicus maintained in Artificial Insemination Center were used and the spermatozoa samples was assessed for Plasma Membrane Integrity and CASA evaluation. The stabilization phase (5 degrees C/4 hours) was performed in the CR as well as in the TRB, and then samples were exposed to nitrogen vapor during 20 minutes and then plunged into nitrogen. The statistical analysis was done using the variance analysis and the significance level was set at 5%. In the CR the post-thawing parameters for PM and ALH were higher (p < 0.05) in the extender A (glicine egg-yolk) and extender B (glicine egg-free) when compared with extender C (TRIS egg-yolk). As for BCF, STR and LIN, the parameters were higher (p < 0.05) in extender B than in C. Samples that were stabilized in the TRB presented higher post-thawing parameters (p < 0.05) for PM and LIN in extender A and extender B when compared with C. BCF and STR parameters were higher (p < 0.05) in extemder B when compared with C. Extender B samples had higher (p < 0.05) PMI when stabilized in CR. The findings in this experiment enable us to say that both CR and TRB were effective in keeping the viability of post-thawing bull semen.

Anterior Tooth Rehabilitation With Frozen Homogenous Bone Graft and Immediately Loaded Titanium Implant Using Computer-Guided Surgery

Computed tomographic scanning is a precise, noinvasive surveying technique that enables the professionals to improve the precision of implant placement by building a prototype that allows the confection of surgical guides. The authors present a clinical case of anterior tooth rehabilitation with frozen homogenous bone graft and immediately loaded titanium implant using computer-guided surgery. A multislice computed tomography was realized, and a prototype was built. All the procedures were previously realized in the prototype before started in the patient. This technique allows a better surgical planning, makes the procedures more accurate, and reduces surgery time.

Evaluation of Cu, Mn, and Se in Vegetables Using Ultrasonic Extraction and GFAAS Quantification

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Nutritional composition, phenolic compounds, nitrate content in eatable vegetables obtained by conventional and certified organic grown culture subject to thermal treatment

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Loss in tocopherols and oxidative stability during the frying of frozen cassava chips

The present study was aimed at verifying tocopherols losses and oxidative stability changes in vegetable oils used in discontinuous frying. The frying of frozen cassava chips was carried out in a household electric frying pan, where the oil was heated to a temperature of 180 degrees C for 25 hours, with fresh oil replacement. The results obtained from the analytical determinations were submitted to variance analysis, in a factorial scheme, using a completely randomized design, making it possible to determine the influence of the type of oil and frying times on changes in the oil. The data show that the smallest changes occur in palm oil, which is more saturated. For sunflower and cottonseed oils, which are more unsaturated, there was a clear decrease in both tocopherol concentration and oxidative stability.

Fresh-frozen human bone allograft in vertical ridge augmentation: clinical and tomographic evaluation of bone formation and resorption

The aim of the current study is to evaluate fresh-frozen human bone allografts (FHBAs) used in vertical ridge augmentation clinically and by computed tomography, and to analyze the resulting bone formation and graft resorption. Sixteen FHBAs were grafted in the maxillae and mandibles of 9 patients. The FHBAs, which were provided by the Musculoskeletal Tissue Bank of Marilia Hospital (Unioss), were frozen at -80A degrees C. After 7 months, dental implants were placed and bone parameters were evaluated. Vertical bone formation was measured by computerized tomography before (T0) and at 7 months (T1) after the surgical procedure. Bone graft resorption was measured clinically from a landmark screw head using a periodontal probe. The results were analyzed by Student's t-test. Significant differences existed in the bone formation values at T0 and T1, with an average change of 4.03 +/- A 1.69 mm. Bone graft resorption values were 1.0 +/- A 0.82 mm (20%). Implants were placed with varying insertion torque values (35-45 Ncm), and achieved primary stability. This study demonstrates that FHBAs promote satisfactory vertical bone formation with a low resorption rates, good density, and primary implant stability.

Fresh-frozen human bone graft for repair of defect after adenomatoid odontogenic tumour removal

The aim of this paper was report the clinical, radiographic, and histological case of adenomatoid odontogenic tumour (AOT) in adolescent woman as well as present the reconstructive treatment of AOT using fresh-frozen human bone graft with guided bone regeneration. AOT is a benign, noninvasive lesion with slow but progressive growth. Biopsy and microscopic examination confirmed the presence of an AOT. Treatment was conservative and the prognosis was excellent. The patient has been followed-up for without recurrence. The use of fresh-frozen human bone graft can be a safe choice for reconstruction of the bone defects to treat AOT.

Influence of fresh frozen plasma as a trigger factor for kidney dysfunction in cardiovascular surgery

OBJETIVO: A disfunção renal é uma complicação importante no cenário de pós-operatório de cirurgia cardiovascular. Como fatores de risco conhecidos no intraoperatório para o seu desenvolvimento destacam-se a circulação extracorpórea, a hemodiluição, drogas antifibrinolíticos e a transfusão sanguínea. O objetivo deste estudo é identificar os fatores de risco na transfusão de sangue e derivados para o desenvolvimento de disfunção renal em pacientes submetidos à cirurgia cardiovascular. MÉTODOS: Noventa e sete pacientes foram estudados e 84 foram analisados. A amostra foi estratificada em dois grupos, sendo que o incremento de 30% na creatinina sérica no pós-operatório foi considerado para o grupo com disfunção renal (n = 9; 10,71%). O grupo não disfunção renal foi caracterizado pela creatinina sérica, que permaneceu inferior a aumento de 30% no pós-operatório (n = 75; 89,28%). RESULTADOS: Foi observado que a transfusão de plasma fresco congelado no grupo não disfunção renal foi de 2,05 ± 0,78 unidades e 3,80 ± 2,16 unidades no grupo disfunção renal com P= 0,032. CONCLUSÃO: Foi possível associar, nesta série de pacientes, que a transfusão de plasma fresco congelado foi um fator de risco para disfunção renal pós-operatório de cirurgia cardiovascular.

Effect of modifiers on thermal behaviour of Se in acid digestates and slurries of vegetables by graphite furnace atomic absorption spectrometry

The influence of sample preparation strategy of vegetables on the electrothermal behaviour of Se without and with chemical modifiers such as Pd(NO3)(2), Pd(NO3)(2) + Mg(NO3)(2), Pd(NO3)(2) + Cd(NO3)(2), pre-reduced Pd, Mg(NO3)(2), and Ni(NO3)(2) was investigated. Acid digestates and slurries of vegetables (0.1% m/v in 1% m/v HNO3 + 0.005% v/v of Triton X-100) were used to prepare reference solutions or slurries. For 10 mul of each modifier tested, pyrolysis and atomization temperatures were evaluated using pyrolysis and atomization curves, respectively. Best conditions, such as thermal stability, signal profile, repeatability and sensitivity were attained using Pd(NO3)(2) as chemical modifier. The following heating program (temperature, ramp/hold time) of the graphite tube of the Varian SpectrAA-800Z atomic absorption spectrometer was used: dry step (85 degreesC, 5/0 s; 95 degreesC, 40/0 s; 120 degreesC, 10/.5 s); pyrolysis step (1400 degreesC, 10/3s); atomization step (2200 degreesC, 1/2 s); clean step (2600 degreesC, 2/0 s). This pyrolysis temperature is 800 degreesC higher than when measuring without any modifier. For 20 muL sample volume and 10 mug Pd(NO3)(2), analytical curves in the 3.0-30 mug Se 1(-1) range were obtained. The method was applied for Se determination in acid digestates and slurries of 10 vegetable samples and one standard reference material (rice flower) and results were in agreement at 95% confidence level. Recoveries varied from 89 to 95% for spiked samples. The lifetime of the graphite tube was ca. 250 firings and the relative standard deviations (n = 12) for a typical acid digestate and slurry containing 20 mug Se 1(-1) were 3.8% and 8.3%, respectively. The limits of detection were 2.0 mug Se 1(-1) and 0.6 mug Se 1(-1) Se for digestates and slurries, respectively. (C) 2002 Elsevier B.V. Ltd. All rights reserved.

Influence of fluid concentration on freezing point depression and thermal conductivity of frozen orange juice

The freezing point depression (FPD) of orange juice at different concentrations was measured by using a simple apparatus. Results showed that the initial freezing point decreased approximately 90% with the increase of juice concentration between 46degrees and 66degrees Brix (water content respectively between 52.8 and 32.8% w/w). The thermal conductivity of orange juice as a function of fluid concentration was also investigated by using a coaxial dual-cylinder apparatus. Below the freezing point, the thermal conductivity was strongly affected by both the orange juice concentration and temperature. Simple equations in terms of water content and temperature could be adjusted to experimental data of FPD and thermal conductivity.

Rheological properties of frozen concentrated orange juice (FCOJ) as a function of concentration and subzero temperatures

Data on flow properties of Frozen Concentrated Orange Juice (FCOJ) produced from oranges cv. Pera-Rio (65.04 Brix, 8.8% w/w pulp content, 2.5% w/w pectin, 3.84% citric acid, 1.293 g cm(-3)) from -18 to 0 degrees C were fitted with appropriate predictive models. The power law model was found to be the most appropriate to fit the flow curves obtained for FCOJ between 46.56 and 65.04 degrees Brix. In higher concentrations, thixotropy was observed and showed more temperature dependence. A single equation combining Arrhenius and exponential relationships was applied to describe the temperature effect and shear rate on the quantity of breakdown of FCOJ.