Management of cardiovascular diseases with micro systems and nanotechnology

Cardiovascular diseases are the leading cause of death and morbidity in industrialized nations and are becoming an urgent health problem for all nations due to the unstoppable trend of an ageing and obese population. Due to the rapid development of micro total analysis systems (μTAS) and nanotechnology in recent years, they will play an important role in the diagnosis, management, and therapy of cardiovascular diseases. It is envisaged that the micro and nanotechnologies developed for treating other diseases shall be explored for cardiovascular applications to reduce the research effort required for commercializing the devices and drugs to meet the increasing demand of the cardiovascular patients.

Natriuretic peptide receptor signalling in the gills of fishes

Natriuretic peptide hormones exert their effects by binding to receptor proteins and activating cellular responses. Fish gills interface with the aquatic environment. Therefore, natriuretic peptide receptor activity in gills from marine and freshwater fishes was examined. The potencies of natriuretic peptides were compared and a novel cellular response was identified.

Some osmoregulatory parameters in selected fishes of the Australasian region

Fish must maintain their internal ionic concentration. This occurs through co-ordination of cellular ion channels and transporters, and hormones acting on and within the cells of the gill, kidney, intestine, and, in some species, unique organs. This study measured some of these transporters and hormones in unusual species of the Australasian region.

Nitric oxide and vascular regulation in fishes and amphibians

Nitric oxide is an important molecule in the regulation of the cardiovascular system and blood pressure. This research provided new insights into the evolution of nitric oxide control of blood vessels by showing how nitric oxide signalling causes vasodilation in the circulation of amphibians and fishes.

Identification of Na+/H+ exchangers in the gills of fishes

The exchange of sodium and protons across the gills of fishes has long been associated with osmoregulatory and acid-base regulatory mechanisms in both freshwater and marine fishes. This thesis identifies several types of sodium/proton exchangers in the gills of fishes from different taxonomic classes. In addition, it was observed that the expression of sodium/proton exchanger messenger RNA was upregulated for 24 hours following induced metabolic acidosis in the Atlantic hagfish suggesting that sodium/proton exchangers have functioned in acid/base regulation from early in vertebrate history.

Promises of nanotechnology for drug delivery to brain in neurodegenerative diseases

Brain is a delicate organ, isolated from general circulation and characterized by the presence of relatively impermeable endothelial cells with tight junctions, enzymatic activity and the presence of active efflux transporter mechanisms. These formidable obstacles often block drug delivery to the brain across the blood-brain barrier (BBB). Although several promising molecules have the potential in the in vitro settings but lack of in vivo response is probably because the molecule cannot reach the brain in a sufficient concentration. Drug delivery across the BBB is a major limitation in the treatment of central nervous system (CNS) disorders and CNS infections. This review deals with the role of nanobiotechnology in CNS drug delivery, in which three categories of carbon nanotubes, nanowires and nanoparticles (NPs) are explained. The small size of the NPs makes them an ideal choice to penetrate the BBB. Several mechanisms are involved in this process and various strategies are used. There are some concerns about the safety of NP entry in the brain that need to be resolved before human use. Although there is no approved nanotechnology-based CNS drug available the future for such neuro-nanobiotechnology based delivery system developments is promising.

Applications of aptamers in nanodelivery systems in cancer, eye and inflammatory diseases

Aptamers are an interesting class of molecules that have potential in many facets of human health. They are characterized by high affinity and specificity to their targets, are small in size, have similar properties to antibodies, but are made synthetically. All of these properties, among others, give aptamers the potential to diagnose, image and treat like no other molecules. By combining the unique properties of aptamers with the ever expanding field of nanotechnology and all it has to offer, we are entering a very promising new area of targeted nanodelivery treatments. These treatments have found success in the complex disease processes of cancer, eye and inflammatory diseases.

MicroRNA in human cancer and chronic inflammatory diseases

MicroRNAs (miRNAs) are the non-coding RNAs that act as post-translational regulators to their complimentary messenger RNAs (mRNA). Due to their specific gene silencing property, miRNAs have been implicated in a number of cellular and developmental processes. Also, it has been proposed that a particular set of miRNA spectrum is expressed only in a particular type of tissue. Many interesting findings related to the differential expression of miRNAs in various human diseases including several types of cancers, neurodegenerative diseases and metabolic diseases have been reported. Deregulation of miRNA expression in different types of human diseases and the roles various miRNAs play as tumour suppressors as well as oncogenes, suggest their contribution to cancer and/or in other disease development. These findings have possible implications in the development of diagnostics and/or therapeutics in human malignancies. In this review, we discuss various miRNAs that are differentially expressed in human chronic inflammatory diseases, neurodegenerative diseases, cancer and the further prospective development of miRNA based diagnostics and therapeutics.

Habitat suitability for marine fishes using presence-only modelling and multibeam sonar

Improved access to multibeam sonar and underwater video technology is enabling scientists to use spatially-explicit, predictive modelling to improve our understanding of marine ecosystems. With the growing number of modelling approaches available, knowledge of the relative performance of different models in the marine environment is required. Habitat suitability of 5 demersal fish taxa in Discovery Bay, south-east Australia, were modelled using 10 presence-only algorithms: BIOCLIM, DOMAIN, ENFA (distance geometric mean [GM], distance harmonic mean [HM], median [M], area-adjusted median [Ma], median + extremum [Me], area-adjusted median + extremum [Mae] and minimum distance [Min]), and MAXENT. Model performance was assessed using kappa and area under curve (AUC) of the receiver operator characteristic. The influence of spatial range (area of occupancy) and environmental niches (marginality and tolerance) on modelling performance were also tested. MAXENT generally performed best, followed by ENFA-GM and -HM, DOMAIN, BIOCLIM, ENFA-M, -Min, -Ma, -Mae and -Me algorithms. Fish with clearly definable niches (i.e. high marginality) were most accurately modelled. Generally, Euclidean distance to nearest reef, HSI-b (backscatter), rugosity and maximum curvature were the most important variables in determining suitable habitat for the 5 demersal fish taxa investigated. This comparative study encourages ongoing use of presence-only approaches, particularly MAXENT, in modelling suitable habitat for demersal marine fishes.