An Observational Study of Paediatric Preoperative Transfusion Practice in a Resource-Limited Setting

World Journal of Surgery - Paediatric anaemia is highly prevalent in low–middle-income countries and can negatively impact postoperative outcomes. Currently, there are no guidelines for the...     

Effect of amino acids and dipeptides on accumulation of ammonia in the medium during <Emphasis Type="Italic">in vitro</Emphasis> maturation and fertilization of porcine oocytes

Aim:  The present study was designed to investigate the effect of amino acids and their dipeptides on the accumulation of ammonia in the medium during in vitro maturation (IVM) and in vitro fertilization (IVF) of porcine oocytes.
Methods:  The IVM and IVF media were modified North Carolina State University-37 solution and modified Tyrode's albumin lactate pyruvate, respectively. Porcine oocytes were matured in IVM medium containing 75–2400 µmol ammonia. Amino acids (1.0 mmol) or their dipeptides (2.0 mmol) related to the urea cycle were added individually to the IVM and IVF media containing 300 µmol ammonia. Oocyte maturation and fertilization were assessed using acetic–orcein staining, and the accumulation of ammonia in the media was measured using the indophenol method.
Results:  Percentages of metaphase II (MII) were adversely affected ( P <  0.05) by ≥300 µmol concentrations of ammonia in the IVM medium. In the presence of 300 µmol ammonia in the IVM and IVF media, glutamic acid, l -alanyl-L-glutamine (AlaGln), l -glycyl-L-glutamine (GlyGln) and AlaGln + GlyGln showed the highest rate ( P <  0.05) of MII, monospermic fertilization, and the lowest rate ( P <  0.05) of ammonia accumulation in the media.
Conclusion:  AlaGln and GlyGln in IVM and IVF media were more stable and effective than the individual amino acids in reducing the accumulation of ammonia, and increased the rate of porcine oocyte MII and monospermic fertilization in vitro . (Reprod Med Biol 2007; 6 : 165–170)     

Effect of fructose on motility, acrosome reaction and in vitro fertilization capability of boar spermatozoa

Aim:  The present study was carried out to investigate the effects of fructose supplementation in glucose containing mTALP medium on motility, acrosome reaction and in vitro fertilization capability of boar spermatozoa.
Methods:  Boar spermatozoa were preincubated, swum-up, resuspended and then incubated for 6 h in mTALP medium supplemented with 0, 0.5, or 1.0 mmol fructose in the presence of 5.0 mmol glucose. After completion of the specified incubation period, motility was determined subjectively on the basis of speed of progression and on the type of forward movement of spermatozoa; acrosome status was evaluated by applying a triple staining technique; and in vitro fertilization capability was assessed by acetic–orcein staining.
Results:  The combination of fructose and glucose (0.5 + 5.0 mmol) supplements in mTALP medium improved sperm motility significantly ( P <  0.05), more than glucose alone (5.0 mmol) at 2–6 h of incubation. Acrosome reaction (live spermatozoa) and the sperm penetration rate was increased significantly ( P <  0.05) when the spermatozoa were treated with the combination of fructose and glucose compared with glucose alone, but the incidence of polyspermy was not significantly different between the treatments.
Conclusion:  These results suggest that the combination of glucose and fructose as supplements in mTALP medium improve the progressive motility, acrosome reaction and fertilization capability of boar spermatozoa. (Reprod Med Biol 2006; 5: 255–261)     

Molecular biology and riddle of cancer: the ‘Tom & Jerry’ show

From the conventional Bird’s eye, cancer initiation and metastasis are generally intended to be understood beneath the light of classical clonal genetic, epigenetic and cancer stem cell model. But inspite decades of investigation, molecular biology has shown hard success to give Eagle’s eye in unraveling the riddle of cancer. And it seems, tiring Tom runs in vague behind naughty Jerry.     

Effects of relaxin and IGF-I on capacitation, acrosome reaction, cholesterol efflux and utilization of labeled and unlabeled glucose in porcine spermatozoa

Aim:  Relaxin and insulin-like growth factor (IGF)-I have pronounced effects on the male and female reproductive tracts. The aim of this study was to investigate the effects of relaxin and IGF-I on the motility, capacitation, acrosome reaction, cholesterol efflux and utilization of glucose in porcine spermatozoa.
Methods:  Swim-up separated spermatozoa that had been washed twice were incubated at 37°C for 1 or 4 h in modified Tyrode's albumin lactate pyruvate (mTALP) medium supplemented without (control) or with relaxin (20 ng/mL) or IGF-I (20 ng/mL) or both (10 + 10 ng/mL).
Results:  Progressive motility and the induction rate of capacitation and acrosome reaction were increased ( P <  0.05) by relaxin and IGF-I alone or in combination, especially after 4 h of incubation. Relaxin alone or combined with IGF-I enhanced ( P  < 0.05) the cholesterol efflux after 4 h, whereas IGF-I alone did not show any significant effect on the cholesterol efflux compared with the control at any time point. The utilization rates of labeled and unlabeled glucose increased ( P <  0.05) in spermatozoa incubated with relaxin or IGF-I alone or in combination compared with the control.
Conclusion:  Thus, supplementation of relaxin alone or combined with IGF-I into the medium possibly plays a beneficial role in porcine spermatozoal prefertilization events in vitro . (Reprod Med Biol 2008; 7 : 29–36)     

Impact of missense mutations in survival motor neuron protein (SMN1) leading to Spinal Muscular Atrophy (SMA): A computational approach

Spinal muscular atrophy (SMA) is a neuromuscular disorder caused by the mutations in survival motor neuron 1 gene (SMN1). The molecular pathology of missense mutations in SMN1 is not thoroughly investigated so far. Therefore, we collected all missense mutations in the SMN1 protein, using all possible search terms, from three databases (PubMed, PMC and Google Scholar). All missense mutations were subjected to in silico pathogenicity, conservation, and stability analysis tools. We used statistical analysis as a QC measure for validating the specificity and accuracy of these tools. PolyPhen-2 demonstrated the highest specificity and accuracy. While PolyPhen-1 showed the highest sensitivity; overall, PolyPhen2 showed better measures in comparison to other in silico tools. Three mutations (D44V, Y272C, and Y277C) were identified as the most pathogenic and destabilizing. Further, we compared the physiochemical properties of the native and the mutant amino acids and observed loss of H-bonds and aromatic stacking upon the cysteine to tyrosine substitution, which led to the loss of aromatic rings and may reduce protein stability. The three mutations were further subjected to Molecular Dynamics Simulation (MDS) analysis using GROMACS to understand the structural changes. The Y272C and Y277C mutants exhibited maximum deviation pattern from the native protein as compared to D44V mutant. Further MDS analysis predicted changes in the stability that may have been contributed due to the loss of hydrogen bonds as observed in intramolecular hydrogen bond analysis and physiochemical analysis. A loss of function/structural impact was found to be severe in the case of Y272C and Y277C mutants in comparison to D44V mutation. Correlating the results from in silico predictions, physiochemical analysis, and MDS, we were able to observe a loss of stability in all the three mutants. This combinatorial approach could serve as a platform for variant interpretation and drug design for spinal muscular dystrophy resulting from missense mutations.     

Effect of relaxin on motility, acrosome reaction and viability of cryopreserved boar spermatozoa

Background and Aims:   Relaxin has an important role in stimulating motility and the acrosome reaction (AR) of fresh boar spermatozoa. The objective of the present study was to determine whether relaxin can improve the motility, AR and viability of cryopreserved boar spermatozoa.
Methods:   Cryopreserved boar spermatozoa were thawed, washed and incubated at 37°C for 4 h in modified Beltsville thawing solution supplemented with 0, 20 or 40 ng/mL relaxin. Sperm motility, AR, viability, and incorporation and oxidation of ¹⁴C-glucose were evaluated during 0–4 h of incubation.
Results:  The results show that the supplementation of relaxin (especially at 20 ng/mL) in the thawing solution improved sperm motility significantly ( P  < 0.05) at 1–3 h of incubation. The percentage of acrosome reacted live spermatozoa was improved significantly ( P  < 0.05) when the spermatozoa were treated with 20 ng/mL relaxin. Viability was not significantly ( P  > 0.05) improved by supplementation with relaxin. The rates of incorporation and oxidation of ¹⁴C-glucose were increased in correlation with AR up to 4 h of incubation.
Conclusion:  We conclude that relaxin can improve the sperm motility and AR, and enhance the glucose metabolism of cryopreserved boar spermatozoa. (Reprod Med Biol 2006; 5 : 215–220)