Smart microneedle coatings for controlled delivery and biomedical analysis

The work presented demonstrates an unconventional approach in the preparation of smart microneedle (MN) coatings utilising electrohydrodynamic atomisation (EHDA) principles. Stainless steel (600-900 µm in height) MNs were coupled to a ground electrode (in the EHDA coating set-up) with the deposition distance and collecting methodology varied for an ethanol:methanol (50:50) vehicle system. The preparation of nano- and micrometre-scaled pharmaceutical coatings was achieved. Fluorescein dye (serving as potential drug, sensory materials or disease state markers) and polyvinylpyrrolidone (PVP, polymer matrix system) formed the remaining components of the coating formulation. Based on these excipients and by varying the coating process, particles (100 nm to 3 µm) and fibres (400 nm to 1 µm) were deposited directly on MNs in controlled and selectable fashion (flow rates variable ∼ 5-50 µL/min, applied voltage variable 6-19 kV). These demonstrated options for multiple targeting and analysis applications. The underlying EHDA process permits room temperature fabrication, controlled output and scale-up potential for emerging MN devices as drug systems or lab-chip testing devices.

G-CSF and G-CSFR are highly expressed in human gastric and colon cancers and promote carcinoma cell proliferation and migration

Background:

Granulocyte colony-stimulating factor (G-CSF) is a pro-inflammatory cytokine that stimulates myeloid stem cell maturation, proliferation, and migration into circulation. Despite being a known growth factor, the impact of G-CSF on solid tumours has not been well examined. G-CSF receptor (G-CSFR) is expressed by some tumours, and thus the aim of this study was to examine the expression and impact of G-CSF and G-CSFR on gastrointestinal tumours.

Methods:

In this study, G-CSF expression was examined in human gastric and colon tumours and by tumour-derived stromal myofibroblasts and carcinoma cells. G-CSFR expression was examined on carcinoma cells isolated from human tissues. The effects of G-CSF on gastric and colon carcinoma cell proliferation, migration, and signalling were examined.

Results:

G-CSFR was highly expressed in 90% of human gastric and colon carcinomas. G-CSF was also found to be highly produced by stromal myofibroblasts and carcinoma cells. Exposure of carcinoma cells to G-CSF led to increased proliferation and migration, and expansion of a sub-population of carcinoma cells expressing stem-like markers. These processes were dependent on ERK1/2 and RSK1 phosphorylation.

Conclusions:

These data suggest that the G-CSF/R axis promotes gastric and colorectal cancer development and suggest they are potential tumour targets.

Clinical benefits of concurrent capecitabine and cisplatin versus concurrent cisplatin and 5-flurouracil in locally advanced squamous cell head and neck cancer

We aimed to assess the efficacy and safety of concurrent capecitabine and cisplatin over concurrent cisplatin and 5-flurouracil (5-FU) in locally advanced squamous cell carcinoma of the head and neck. One hundred and fifty-three patients (all of whom had stage III or IV unresectable disease with no distant metastases and who had received two cycles of taxol and cisplatin chemotherapy) were randomly assigned to receive either concurrent cisplatin (75 mg/m(2) in day 1 and 2) and 5-FU (750 mg/m(2) in day 1, 2, and 3) from the first day of radiotherapy at an interval of 3 weeks (Arm I) or cisplatin (75 mg/m(2) in day 1 and 2) and capecitabine (750 mg/m(2) in two divided doses from day 1-14) from the first day of radiotherapy at a 3-week interval (Arm II). Results showed that patients in Arm II had a significantly better rate of complete response, fewer nodes, and better overall response compared to those in Arm I. The two groups had a similar 3-year disease-free survival, progression free survival, and overall survival, i.e. they did not differ significantly. Variables indicating the quality of life of the two groups were compared. Patients in Arm II had a significantly higher quality of life compared to those in Arm I. The two groups had similar treatment-related acute and late toxicity, i.e. they did not differ significantly. These results have thoroughly substantiated the contention that concurrent chemoradiation with capecitabine and cisplatin may be regarded as an effective and well-tolerated regimen in the treatment of the patients with locally advanced head and neck cancer.

Design and construction of a single tube, quantitative endpoint, LATE-PCR multiplex assay for ventilator-associated pneumonia

AIMS

The goal of this study was to develop a molecular diagnostic multiplex assay for the quantitative detection of microbial pathogens commonly responsible for ventilator-associated pneumonia (VAP) and their antibiotic resistance using linear-after-the-exponential polymerase chain reaction (LATE-PCR).

METHOD AND RESULTS

This multiplex assay was designed for the quantitative detection and identification of pathogen genomic DNA of methicillin-resistant Staphylococcus aureus (MRSA), Acinetobacter baumannii, Pseudomonas aeruginosa, plus a control target from Lactococcus lactis. After amplification, the single-stranded amplicons were detected simultaneously in the same closed tube by hybridization to low-temperature molecular beacon probes labelled with four differently coloured fluorophores. The resulting hybrids were then analysed by determining the fluorescence intensity of each of the four fluorophores as a function of temperature.

CONCLUSIONS

This LATE-PCR single tube multiplex assay generated endpoint fluorescent contours that allowed identification of all microbial pathogens commonly responsible for VAP, including MRSA. The assay was quantitative, identifying the pathogens present in the sample, no matter whether there were as few as 10 or as many 100 000 target genomes.

SIGNIFICANCE AND IMPACT OF THE STUDY

This assay is rapid, reliable and sensitive and is ready for preclinical testing using samples recovered from patients suffering from ventilator-associated pneumonia.

Determination of the mode of action of enterolysin A, produced by Enterococcus faecalis B9510

AIM

The current study aimed to visualize the damage caused by enterolysin A to the cells of sensitive strains and to find out cleavage site within the peptidoglycan moiety of bacterial cell walls.

METHODS AND RESULTS

Enterolysin A produced by a local isolate, Enterococcus faecalis B9510 was found to rapidly kill cells of the sensitive strain Lactococcus lactis ssp. cremoris 2144 during 120 min of treatment as compared to the untreated control where no such effect was observed. Transmission electron microscopy of the enterolysin A-treated cells revealed leaking of the cytoplasmic contents ultimately resulting in complete lysis of cell walls. To find the cleavage site, purified cell walls of L. lactis ssp. cremoris 2144, Pediococcus pentosaceus 43201 and Lactobacillus delbrueckii ssp. bulgaricus ATCC 11842 were treated with enterolysin A, and liberated amino acids were derivatized for N and C terminals and analysed using thin layer chromatography on silica gel with isopropanol as solvent. The results showed that enterolysin A cleaves the peptide bonds at two locations within peptidoglycan subunits. The first location is between L-alanine and D-glutamic acid of the stem peptide and the other location is between L-lysine of the stem peptide and D-aspartic acid of the interpeptide bridge.

CONCLUSIONS

Enterolysin A cleaves the peptide bonds within the stem peptide as well as in the interpeptide bridge of Gram-positive bacterial cell walls. This gives a possible reason for the broad spectrum of enterolysin A activity.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first report identifying the cleavage site of enterolysin A within the cell walls of sensitive bacteria. This will help in identifying potential applications for enterolysin A.

Methylation profile of promoter region of p16 gene in colorectal cancer patients of Kashmir valley

Colorectal cancer (CRC) commonly known as bowel cancer is the third most common cause of cancer-related deaths in the western world and has been reported to show geographical variation in its incidence. Cancer development and progression is a complex process dictated by changes in expression and regulation of various genes which include tumor suppressor genes, DNA repair genes, translation regulatory genes and others. The aim of this case control study was to analyze the promoter hypermethylation at CpG islands of p16 gene in CRC patients among the Kashmiri population and co- relate it with expression pattern of p16. Genomic DNA was isolated from surgically resected tumor and adjacent normal samples and was modified using bisulphite modification kit. Methylation-specific polymerase chain reaction (PCR) was setup for the analysis of the promoter hypermethylation of p16 gene. The epigenetic analysis revealed that unlike other high risk regions, Kashmiri population has a different promoter hypermethylation profile of p16 gene as 66 percent of the cases showed p16 promoter hypermethylation in comparison to 20 percent of the normal cases which also showed promoter hypermethylation of p16 gene. The association of promoter hypermethylation with colorectal cancer was found to be significant (P=0.0006). Occurrence of p16 promoter hypermethylation was found to be unequally distributed in males and females with more frequency in males than in females but the difference was not statistically significant(P =0.7635). Similarly, frequency of p16 promoter hypermethylation was found to be certainly higher in Stage III/IV (83.33 percent) compared to Stage I/II (56.25 percent) but the difference was not statistically significant (P =0.0673). Also, the degree of p16 promoter hypermethylation increased with the increasing severity of the lesion but the difference was not again statistically significant (P =0.6145). Promoter hypermethylation correlated with the decrease in expression of the p16 gene in CRC patients leading to the diseased phenotype. These results suggest that p16 aberrant promoter hypermethylation in Kashmiri population contributes to the process of carcinogenesis in CRC and may be developed into a valuable tool for CRC diagnosis at early stages.

Xyloglucan endotransglycosylase/hydrolase genes from a susceptible and resistant jute species show opposite expression pattern following Macrophomina phaseolina infection

Two of the most widely and intensively cultivated jute species, Corchorus capsularis and Corchorus olitorius, suffer severely from a stem rot disease caused by the fungus Macrophomina phaseolina. Wild jute species, C. trilocularis, shows resistance to this pathogenic fungus. In this study, the technique of differential display was applied to identify genes which are differentially expressed, under both infected and un-infected conditions, between C. trilocularis and C. olitorius var O-72. Two xyloglucan endotransglycosylase/hydrolase (XTH) genes designated CoXTH1 (from Corchorus olitorius) and CtXTH1 (from C.trilocularis) were identified from each of the two species which show different expression patterns upon fungal infection. A steady rise in the expression of CtXTH1 in response to infection was observed by quantitative real time PCR whereas the expression of CoXTH1 was found to be downregulated. Full length sequences of these two genes were determined using primer based gene walking and RACE PCR. This study confirms the involvement of XTH in molecular interactions between M. phaseolina and jute. However, it remains to be explored whether XTH is an essential component of the signaling pathway involved in plant-fungal interaction.

Infection control in United Kingdom neonatal units: variance in practice and the need for an evidence base

Infection prevention is a cornerstone of good neonatal care. There are, however, few research data to support infection control approaches in this population. Through a structured telephone interview we surveyed all neonatal units in the United Kingdom to identify infection control issues, practices and policies. Eighty seven percent of the 198 neonatal units participated. Twenty one units (12.2%) had closed with infection control issues in the last year; 14.1% had current infection control concerns; 81.5% of units decolonised MRSA positive infants, but over 15 regimens were used. Wide variations in hygiene measures were identified; 22.1% of units used theatre scrubs for all staff, 7.6% used aprons and 5.8% required gloves to be worn when entering clinical areas. Only 54% required hand washing and alcohol gel before entry to a patient care area; 11.6% required only the use of alcohol gel.

Although infection control issues are resulting in neonatal unit closures and risks to patients, there are considerable variations in hygiene and screening practices. There is little data to support the safety or efficacy of decolonisation in neonatal populations, but this is widely practised. Research needs to be carried out to evaluate the effectiveness of screening practices and decolonisation in order that a consistent evidence-based approach can be applied.