Computer Simulations Improve University Instructional Laboratories

Laboratory classes are commonplace and essential in biology departments but can sometimes be cumbersome, unreliable, and a drain on time and resources. As university intakes increase, pressure on budgets and staff time can often lead to reduction in practical class provision. Frequently, the ability to use laboratory equipment, mix solutions, and manipulate test animals are essential learning outcomes, and “wet” laboratory classes are thus appropriate. In others, however, interpretation and manipulation of the data are the primary learning outcomes, and here, computer-based simulations can provide a cheaper, easier, and less time- and labor-intensive alternative. We report the evaluation of two computer-based simulations of practical exercises: the first in chromosome analysis, the second in bioinformatics. Simulations can provide significant time savings to students (by a factor of four in our first case study) without affecting learning, as measured by performance in assessment. Moreover, under certain circumstances, performance can be improved by the use of simulations (by 7% in our second case study). We concluded that the introduction of these simulations can significantly enhance student learning where consideration of the learning outcomes indicates that it might be appropriate. In addition, they can offer significant benefits to teaching staff.     

Restenosis: A challenge to angioplasty

Fatty deposits clog the coronary arteries blocking blood flow to the heart muscles. This leads to coronary artery diseases. The therapeutic approach is to either provide a by-pass or clear the block by a procedure called angioplasty. However, angioplasty has a high rate of restenosisrenarrowing of the artery in due course. Scientists are looking at various options to prevent restenosis. Application of ionising radiation to the site of angioplasty is one such option.     

Computational design optimization for microfluidic magnetophoresis

Current macro- and microfluidic approaches for the isolation of mammalian cells are limited in both efficiency and purity. In order to design a robust platform for the enumeration of a target cell population, high collection efficiencies are required. Additionally, the ability to isolate pure populations with minimal biological perturbation and efficient off-chip recovery will enable subcellular analyses of these cells for applications in personalized medicine. Here, a rational design approach for a simple and efficient device that isolates target cell populations via magnetic tagging is presented. In this work, two magnetophoretic microfluidic device designs are described, with optimized dimensions and operating conditions determined from a force balance equation that considers two dominant and opposing driving forces exerted on a magnetic-particle-tagged cell, namely, magnetic and viscous drag. Quantitative design criteria for an electromagnetic field displacement-based approach are presented, wherein target cells labeled with commercial magnetic microparticles flowing in a central sample stream are shifted laterally into a collection stream. Furthermore, the final device design is constrained to fit on standard rectangular glass coverslip (60 (L)×24 (W)×0.15 (H) mm³) to accommodate small sample volume and point-of-care design considerations. The anticipated performance of the device is examined via a parametric analysis of several key variables within the model. It is observed that minimal currents (<500 mA) are required to generate magnetic fields sufficient to separate cells from the sample streams flowing at rate as high as 7 ml∕h, comparable to the performance of current state-of-the-art magnet-activated cell sorting systems currently used in clinical settings. Experimental validation of the presented model illustrates that a device designed according to the derived rational optimization can effectively isolate (∼100%) a magnetic-particle-tagged cell population from a homogeneous suspension even in a low abundance. Overall, this design analysis provides a rational basis to select the operating conditions, including chamber and wire geometry, flow rates, and applied currents, for a magnetic-microfluidic cell separation device.     

Hypocholesterolemic effect of the hypoglycaemic principle of fenugreek (Trigonella foenum graecum) seeds

A potent hypoglycaemic principle was isolated by us earlier from the seeds of fenugreek. We have now investigated its hypocholesterolemic effect. Hypercholesterolemia was induced in two groups of rabbits (5 each) by feeding orally cholesterol 100 mg/kg/day for one week. From 8th day group I animals (controls) received the same dose of cholesterol for 4 more weeks. Group II animals (treated) were given along with the same dose of cholesterol fenugreek principle at 50 mg/kg/day for 4 weeks. Fenugreek principle not only prevented the elevation of serum cholesterol, (LDL+VLDL)c, triacylglycerols and the ratios of total cholesterol/HDLc and (LDL+VLDL)c/HDLc, but also brought down most of these values. Blood glucose levels were normal. The study shows that the same hypoglycaemic principle has hypocholesterolemic effect also.     

Use of specific IgE to fractions of gynandropsis gynandra pollen inin vitro diagnostic test

The study was aimed at presence of specific IgE antibody levelsinvitro to the identified antigen. Based on positive skin test with Gynandropsis gynandra and elevated levels of total IgE (>325 IU/ml) 104 patients were selected. Healthy, asymptomatic individuals (25) with low total IgE (<325 IU/ml) were included as controls. The mean OD values by ELISA for specific IgE were 0.67±0.21, 0.57±0.18 and 0.56±0.18 with whole pollen antigen, 46-37 kD fraction and 36-32 kD fraction, respectively. The specificity and sensitivity between skin test positivity with whole pollen antigen verses fraction with mol.wt 46-37 kD was 90% and 90% and for fraction with mol.wt 36-32 kD was found to be 81.1% and 89.4%. The clusters with molecular weights 46-37 kD and 36-32 kD may be useful inin vitro diagnostic test. Fractions within these clusters need to be identified for a higher specificity.     

Inhibitory and bactericidal activity of the calmodulin antagonist,trifluoperazine, againstMycobacterium avium in vitro and within human monocyte-derived macrophages

The activity of a calmodulin antagonist, trifluoperazine (TFP), was testedin vitro againstMycobacterium avium (ATCC 25291). The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of this compound forM. avium were 20 and 30 μg/ml, respectively. TFP was also found to completely inhibit the growth of 10 isolates ofM. avium (5 patient isolates and 5 environmental isolates) at 30 μg/ml. At near neutral pH (6.8), the MIC of TFP was found to be 20 μg/ml. However, at pH 5.5 (intracellular pH of macrophages), there was a decrease in the inhibitory activity of the compound against this organism. Interestingly, 99.6% ofM. avium within human monocyte-derived macrophages were killed at a drug concentration of 30 μg/ml, which correlates well with the MBC of TFP againstM. avium in vitro. Although the MIC for TFP appears to be higher than that forMycobacterium tuberculosis H₃₇R_v, our studies suggest that calmodulin antagonists might be useful as drugs against infection due toM. avium. It is suggested that administration of TFP in combination with other known drugs may enhance the overall bactericidal effect.     

Blood lipid peroxidation products and antioxidants in senile cataract

Lipid peroxidation products and antioxidants were estimated in either blood, serum or erythrocytes of 25 cases of early and 25 of advanced senile (50–60 years) cataract and 30 persons of age matched healthy controls. Serum lipid peroxidation products (as malondialdehyde) were significantly higher in patients with early senile (0.25±0.05 μm/dl, P<0.05) and advanced senile cataract (0.29±0.05 μm/dl, P<0.001) as compared to healthy controls (0.22±0.07 μm/dl). Erythrocyte superoxide dismutase levels were lower in patients with early senile (730±60.5 units/gm Hb) and significantly lower in advanced senile (712±50.2 units/gm Hb, P<0.05) cataract than those in healthy controls (767±59.5 units/gm Hb). Serum α-tocopherol was significantly lower (P<0.05) in only advanced senile cataract (0.69±0.08 mg/dl) but not in early senile cataract (0.75±0.08 mg/dl) when compared with healthy controls (0.75±0.09 mg/dl). There was no significant difference in the erythrocyte concentration of reduced glutathione and serum levels of total proteins, β-carotene, vitamin A, ascorbic acid, calcium, magnesium and zinc.