Proliferative effect of Apidra (insulin glulisine), a rapid-acting insulin analogue on mammary epithelial cells

The structural modification of insulin results in the generation of insulin analogues that show altered binding affinities to the insulin receptor and/or the IGF-I receptor, and as a consequence insulin analogues may have altered mitogenic potency. We analysed the proliferative effect of the rapid-acting insulin analogue Apidra (insulin glulisine) on mammary epithelial cells. We show that Apidra and Actrapid (recombinant human insulin) have similar proliferative effects on benign MCF10A and tumorigenic MCF7 cells and on epithelial cells of mouse mammary gland. Whereas Apidra and Actrapid induced similar activation of Erk1/2, activation of Akt/PKB by Apidra was significantly weaker compared to regular insulin. As AKT/PKB, an effector of the phosphoinositide 3-kinase pathway, mediates metabolic effects of insulin, we studied induction of hexokinase-2 in MCF7 cells and hexokinase-2 and hexokinase-4 in HepG2 cells by Actrapid and Apidra. Both genes were not significantly induced by Actrapid and Apidra in these cell lines.

Analysis of signaling pathways related to cell proliferation stimulated by insulin analogs in human mammary epithelial cell lines

Insulin and insulin analogs stimulate proliferation of human mammary epithelial cells. We identified and analyzed the signaling pathways related to cell proliferation induced by regular insulin and by four insulin analogs presently approved for therapeutical use. Benign and malignant mammary cell lines showing different insulin receptor (IR) and IGF-I receptor (IGF-IR) expression patterns were studied. Cell proliferation was studied by crystal violet staining (BrdU-FACS analysis). Activation of insulin and IGF signaling pathways was studied by analysis of the phosphorylation status of IGF-IR and of key signaling proteins of the phosphoinositide 3-kinase (PI3K)/Akt and MAP kinase pathways, by the use of specific PI3K and MAP kinase inhibitors, and by silencing of IR and IGF-IR. Lantus stimulated the growth of MCF7 cells, which show high IGF-IR/IR ratio, significantly at 0.3 nmol/l, while regular insulin (Actrapid and bovine insulin) and other insulin analogs (Novorapid, Humalog, and Levemir) stimulated cell growth at 1.5-15 nmol/l concentrations. No difference between Lantus and the other insulin analogs was observed regarding growth stimulation of MCF10A cells showing low IGF-IR/IR ratio. Growth stimulation of MCF7 cells by Lantus was mainly due to strong activation of the IGF-IR and the MAP kinase pathway. Regular insulin and other insulin analogs tested activated mainly the IR and the PI3K/Akt pathway. We conclude that unlike regular insulin and other insulin analogs, Lantus strongly activates the IGF-IR and the MAP kinase pathway in MCF7 cells and is a strong mitogen for cells characterized by a high-IGF-IR/IR ratio.

Histone methylation and ubiquitination with their cross-talk and roles in gene expression and stability

Methylation of lysine residues of histones is associated with functionally distinct regions of chromatin, and, therefore, is an important epigenetic mark. Over the past few years, several enzymes that catalyze this covalent modification on different lysine residues of histones have been discovered. Intriguingly, histone lysine methylation has also been shown to be cross-regulated by histone ubiquitination or the enzymes that catalyze this modification. These covalent modifications and their cross-talks play important roles in regulation of gene expression, heterochromatin formation, genome stability, and cancer. Thus, there has been a very rapid progress within past several years towards elucidating the molecular basis of histone lysine methylation and ubiquitination, and their aberrations in human diseases. Here, we discuss these covalent modifications with their cross-regulation and roles in controlling gene expression and stability.

Favourable impact of intensity-modulated radiation therapy on chronic dysphagia in patients with head and neck cancer

The aim of this study was to evaluate the impact of intensity-modulated radiation therapy (IMRT) on the incidence and severity of chronic dysphagia in patients with head and neck cancer. 62 evaluable patients with head and neck cancer who were treated with IMRT with or without concurrent chemotherapy were analysed. The majority of the patients (77.4%) had advanced locoregional disease. 45 patients underwent definitive IMRT and 17 received post-operative IMRT. Concurrent chemotherapy was given to 29 of the 45 patients treated with definitive IMRT. The average prescribed dose to clinical target volume (CTV)1 was 66-70 Gy (definitive IMRT) and 56-62 Gy (post-operative IMRT); 60 Gy to CTV2; 54 Gy to CTV3; and 50-52 Gy to the supraclavicular area. At a median follow-up of 19 months, 2-year actuarial locoregional control and survival was 77% and 74%, respectively. At 6 months after IMRT, chronic dysphagia was Grade 0 in 77.1% of patients, Grade 1 in 10.5% and Grade 2 in 12.3%. Acute mucositis showed no correlation with long-term dysphagia. The percutaneous endoscopic gastrostomy or nasogastric tube was removed in all of the patients within 8 weeks of completion of treatment. Xerostomia was Grade 0 in 61.4% of patients, Grade 1 in 31.5% and Grade 2 in 7% of patients. In conclusion, IMRT conferred a major favourable impact on chronic dysphagia in patients with locally advanced head and neck cancers, with satisfactory locoregional control.

Coalescence of spherical beads of retro-HSP12.6 into linear and ring-shaped amyloid nanofibers

The sequence-reversed form of a small heat shock protein, HSP12.6 (retro-HSP12.6), has been reported to fold and assemble into structured tetramers in aqueous solution. Upon raising the protein concentration to ~1.0-1.5 mg/ml, tetrameric retro-HSP12.6 is known to display a tendency to associate further into spherical beads of 18-20 nm in diameter containing folded protein subunits. Here we report that storage of this protein at low temperatures leads to further association of the beaded structures into linear and ring-shaped amyloid nanofibers of 18-20 nm in diameter. The electron micrographs presented in this communication provide the best visual evidence yet that amyloids can form through the association of smaller structured bead-like intermediates. The results also suggest that folded beta-sheet-rich subunits can participate in amyloid formation.

Proliferative effects of insulin analogues on mammary epithelial cells

Structural modification of insulin results in the generation of insulin analogues that show altered binding affinities to the insulin receptor and/or IGF-I receptor. As a consequence these insulin analogues may have increased mitogenic potency. Nine benign or malignant human mammary epithelial cells, which show different insulin receptor and IGF-I receptor expression patterns, were studied regarding mitogenicity of insulin and insulin analogues. Only insulin glargine showed a significantly higher proliferative effect on MCF-7 breast cancer cells compared to regular insulin among a panel of short- or long-acting insulin analogues, that are in clinical use.

A fast and accurate FPGA based QRS detection system

An accurate Field Programmable Gate Array (FPGA) based ECG Analysis system is described in this paper. The design, based on a popular software based QRS detection algorithm, calculates the threshold value for the next peak detection cycle, from the median of eight previously detected peaks. The hardware design has accuracy in excess of 96% in detecting the beats correctly when tested with a subset of five 30 minute data records obtained from the MIT-BIH Arrhythmia database. The design, implemented using a proprietary design tool (System Generator), is an extension of our previous work and uses 76% resources available in a small-sized FPGA device (Xilinx Spartan xc3s500), has a higher detection accuracy as compared to our previous design and takes almost half the analysis time in comparison to software based approach.

Alkylcyanoacrylate nanocapsules prepared from mini-emulsions: a comparison with the conventional approach

Polyalkylcyanoacrylate nanocapsules are being prepared using two different types of o/w-emulsions: a conventional emulsion generated by intensive stirring with a home-made device and a mini-emulsion produced by the action of ultrasonic dispersion, using the alkylcyanoacrylate monomer as a hydrophobic agent. The emulsions and the resulting nanocapsule dispersions are compared using various methods of physical characterization. The formation of solid capsules is indicated by solid state NMR spectra and atomic force microscopy. Differences between the results of both synthetic approaches are found in terms of particle size distribution, zeta potential and tendency towards particle agglomeration. Capsules prepared by ultrasound via the mini-emulsion pathway tend to be smaller and more monodisperse. Their zeta potential is negative with larger absolute values as compared to capsules obtained from conventional emulsions, leading to stronger repulsive interactions and a higher stability against capsule agglomeration.

Human neurocysticercosis managed at Nepalganj Medical College, Teaching Hospital, Kohalpur, Nepal

INTRODUCTION

Neurocysticercosis is the most common parasitic infection of the central nervous system. It is endemic in Central Europe, South Africa, South America and parts of Asia including Nepal.

OBJECTIVE

This study has been conducted with the objectives to know the diagnostic criteria for neurocysticercosis and the outcome of treated cases.

METHODOLOGY

This retrospective study was done at Nepalganj Medical College, Teaching Hospital, Kohalpur, by reviewing the record of the patients managed as case of neurocysticercosis in one financial year.

RESULTS

All patients presented with seizure as a main symptom started in adult life. The mean age was 21 years; 80% were male and 20% female. The diagnosis seemed to be based on clinical presentation, CT scan findings and high index of suspicion. All were put on albendazole, steroids and anticonvulsant drugs; 93% was discharged when fits got controlled, one patient left against medical advice. Follow up record was not available to comment on resolution.

CONCLUSION

Neurocysticercosis is difficult to diagnose and has a significant socioeconomic impact because of chronic morbidity, variable mortality, decreased productivity of affected persons, and high cost of medical diagnosis and treatment. It is therefore suggested to develop criteria for diagnosis of neurocysticercosis to be followed at national level.

Is There a Role for Serum Human Tissue Kallikrein in Detection of Prostate Cancer?

OBJECTIVES

To retrospectively evaluate the diagnostic performance of a serum human tissue kallikrein 11 (hK11) assay to predict the presence of prostate cancer in a screened population of men with a total prostate-specific antigen (PSA) level between 2.5 and 10.0 ng/mL.

METHODS

Frozen serum samples from 114 men with a total PSA level between 2.5 and 10.0 ng/mL who had undergone transrectal prostate ultrasound-guided biopsy with at least 10 cores were retrospectively analyzed for hK11. The performance characteristics of hK11, PSA, hK11/PSA ratio, and hK11 density (hk11/prostate volume) were analyzed for their ability to differentiate cancer from noncancer. The results obtained were analyzed using the Mann-Whitney U test, chi-square test, and receiver operating characteristic curves.

RESULTS

Prostate cancer was diagnosed in 36 (32%) of the 114 men whose serum samples were analyzed. No significant differences were found in hK11 (median 0.71 ng/mL versus 0.69 ng/mL), PSA level (median 3.9 ng/mL versus 4.1 ng/mL), hK11/PSA ratio (median 0.15 versus 0.17), or hK11 density (median 0.015 versus 0.016) between men with and without prostate cancer. A comparison of the areas under the curve for hK11 (0.491), PSA (0.540), hK11/PSA ratio (0.505), and hK11 density (0.589) showed no significant differences.

CONCLUSIONS

In this retrospective study, hK11, hK11/PSA ratio, and hK11 density showed no diagnostic advantage compared with PSA in differentiating cancer from noncancer in men whose total PSA level was in the range of 2.5 to 10.0 ng/mL.

Glycogen synthase kinase-3 protects estrogen receptor alpha from proteasomal degradation and is required for full transcriptional activity of the receptor

Glycogen synthase kinase-3 (GSK-3) plays a key role in the regulation of transcription factors including steroid receptors. Having identified estrogen receptor-alpha (ERalpha) as substrate for GSK-3, the impact of GSK-3 on ERalpha function and activity upon 17beta-estradiol (E2)-dependent activation remains to be clarified. Here we show by using small interfering technology in combination with immunoblot, gene expression analysis, and luciferase reporter assays that silencing of GSK-3alpha or GSK-3beta results in the reduction of ERalpha levels and transcriptional activity in ERalpha-positive breast cancer cells. Using MCF-7 cells we demonstrate that reduction of ERalpha levels upon GSK-3 silencing was due to increased proteasomal degradation of ERalpha rather than inhibition of ERalpha protein synthesis. Indeed, under this condition, ERalpha protein was rescued using the proteasome inhibitor MG132 in presence of the protein synthesis inhibitor cycloheximide. In addition, strong accumulation of ubiquitinated ERalpha was obtained after GSK-3 silencing in the presence of MG132. We conclude that GSK-3 protects ERalpha from proteasomal degradation and plays a crucial role in ERalpha protein stabilization and turnover. Furthermore, in vitro kinase assay depicted that GSK-3beta phosphorylates ERalpha at Ser-118. GSK-3 silencing resulted in decrease of E2-induced nuclear ERalpha phosphorylation at Ser-118 and E2-induced estrogen response element-dependent luciferase reporter gene expression. Neither Ser-118 phosphorylation nor luciferase activity was restored by use of MG132. Moreover, the expression of estrogen-responsive genes (pS2 and progesterone receptor) was decreased upon GSK-3 silencing. These findings demonstrated that GSK-3 is required for E2-induced ERalpha phosphorylation at Ser-118 and full transcriptional activity of the receptor upon E2 stimulation.

Situs inversus with dextrocardia with multiple cardiac lesions in adult

Situs inversus with dextrocardia is the malposition most likely to occur with structurally normal heart; generally discovered on routine chest x-ray or physical examination performed for other reasons. These persons experience normal longevity of life and have similar risk of getting acquired disease as that of other person of same age and sex group. Symptoms related to acquired disorder may also lead to discovery of such cardiac malposition. Incidence of congenital cardiac anomalies in dextrocardia with situs inversus is very low globally but its figure in Nepal is not known. We report an adult of 43 years age having situs inversus with dextrocardia associated with multiple cardiac lesions i.e. ventricular septal defect, aortic regurgitation, mitral regurgitation and tricuspid regurgitation.

DNA polymorphism of insulin-like growth factor-binding protein-3 gene and its association with birth weight and body weight in cattle

Insulin-like growth factor-binding protein-3 (IGFBP-3) is a protein that binds the majority of insulin-like growth factors in circulation for regulation of its action on growth and metabolism of the animals. Animals belonging to Hariana, Holstein-Friesian (HF) and their crossbreds (HF x Hariana) were studied using polymerase chain reaction-restriction fragment length polymorphism and nucleotide sequencing of the IGFBP-3 gene. A 651-bp fragment of the IGFBP-3 gene spanning over a part of exon 2, complete intron 2, exon 3 and a part of intron 3 was amplified and digested with HaeIII restriction enzyme. Three patterns of restriction fragments were observed in HF and crossbred cattle revealing polymorphism in both the populations. The frequency of AA, AB and BB genotypes was 0.65, 0.32 and 0.03 in crossbreds and 0.29, 0.65 and 0.06 in HF respectively. The allelic frequency of the A and B allele was 0.81 and 0.19 in crossbreds and 0.62 and 0.38 in HF cattle respectively. Only one restriction pattern (AA genotype) was observed in all the animals of Hariana breed of Bos indicus showing the absence of polymorphism. Nucleotide sequencing revealed a C --> A mutation in the intron 2 region of the IGFBP-3 gene as the cause of the polymorphism. Least squares analysis revealed a significant effect (p < 0.05) of genotypes on birth weight and body weight (weight at 12, 18 and 24 months of age) of the animals. Animals of AB genotype showed higher birth weight and body weight than the animals possessing AA genotype.