Spatial and temporal variations of coastal microplastic pollution in Hong Kong.

Further to our 2015-16 investigation, this study revealed the repeated presence of microplastics (MPs) in the coastal environment (Deep Bay, Tolo Harbour, Tsing Yi and Victoria Harbour) of Hong Kong from July 2016 to March 2017. The highest level of MPs in coastal surface water (17,182 particles/100 m3) was detected in Tsing Yi. Microplastic abundance in sediments of different sites (59 to 225 plastic particles/kg), however, did not vary significantly. MPs in the size of ≤1 mm were predominated in surface waters (53.3% to 98.6%) and sediments (79.1% to 96.8%). MPs in the shape of pellets and fragments were prevalent in surface waters and sediments respectively. Seasonal pattern of microplastic pollution was consistently observed in Victoria Harbour and Tsing Yi, where the number of MPs was always higher in dry season than in wet season for two consecutive years.

Microplastic pollution in the marine waters and sediments of Hong Kong.

The presence of plastic waste with a diameter of less than 5mm ("microplastics") in marine environments has prompted increasing concern in recent years, both locally and globally. We conducted seasonal surveys of microplastic pollution in the surface waters and sediments from Deep Bay, Tolo Harbor, Tsing Yi, and Victoria Harbor in Hong Kong between June 2015 and March 2016. The average concentrations of microplastics in local coastal waters and sediments respectively ranged from 51 to 27,909particles per 100m3 and 49 to 279particles per kilogram. Microplastics of different shapes (mainly fragments, lines, fibers, and pellets) were identified as polypropylene, low-density polyethylene, high-density polyethylene, a blend of polypropylene and ethylene propylene, and styrene acrylonitrile by means of Attenuated Total Reflectance - Fourier Transform Infrared Spectroscopy. This is the first comprehensive study to assess the spatial and temporal variations of microplastic pollution in Hong Kong coastal regions.

Modulation of cutaneous SP receptors in atopic dermatitis after UVA irradiation.

Atopic dermatitis is a pruritic inflammatory skin disorder, involving immunological and non-immunological factors. Substance P seems to be involved in the pathogenesis of atopic dermatitis. Substance P-containing nerve fibers are increased in the lesional skin of patients with atopic dermatitis and a reduced weal and flare reaction to intradermal injection of substance P has been observed. We investigated the distribution of substance P receptors in the involved skin of patients before and after single or repetitive UVA irradiations. Our results indicate that substance P receptors of the NK-1 subtype are expressed on blood vessels and on epidermal keratinocytes of involved skin of patients with atopic dermatitis. UVA irradiations did not modify the epidermal distribution of substance P receptors but decreased their expression intensity on blood vessels. UVA irradiations seem to decrease skin inflammation through the modulation of NK-1 receptor expression on endothelial cells.

Coexpression of epidermal growth factor receptor and TGF-alpha and survival in upper aerodigestive tract cancer.

In order to find a prognostic marker for the course of disease in head and neck cancer we hypothesized that patients with rapid disease progress would produce increased levels of transforming growth factor alpha (TGF-alpha) and its cell surface receptor, epidermal growth factor receptor (EGFR). Using molecular biological techniques, we examined the incidence of TGF-alpha and EGFR overexpression in 43 patients with tumors of the head and neck. The expression data was correlated with the course of disease in a 4 year follow-up. The tumors were classified into four groups according to the EGFR status: Group 1, no expression for EGFR (15 samples); group 2, expression level 10 for EGFR (18 samples); group 3, expression level 50 for EGFR (7 samples) and group 4, expression level 100 for EGFR (3 samples). Expression for the TGF-alpha protein was only detected in group 4. There was a significant correlation with EGFR/TGF-alpha overexpression in group 4 and survival compared when with group 3 (p < 0.01) and group 1 (p < 0.05). The mean survival for group 1 to 4 was 27, 23, 34 and 10 months, respectively. The analysis of all patients revealed that the patients who expressed EGFR as well as TGF-alpha had the poorest prognosis. Increased production of TGF-alpha and EGFR in tumors of the head and neck may serve both as a marker for tumor progression and as a target for therapy (e.g. inhibition of the autocrine loop, blockage of TGF-alpha binding).