Detection of Zika virus RNA in Aedes aegypti and Aedes albopictus larvae in Klang Valley, Peninsular Malaysia.

We report the presence of Zika virus RNA in naturally infected field captured Aedes aegypti and Ae. albopictus mosquito larvae in Malaysia from May 2016 to April 2017. Zika virus RNA was detected (n = 30) in the larvae of both Aedes mosquito species. Phylogenetic analysis of the NS5 partial sequence of all positive samples shows that the circulating Zika virus in the field collected larvae are of the Asian lineage.

Parasites in soil samples from Signy island, Antarctica.

Studies on parasite populations in Antarctic soils are scarce and thus little is known about the threat of these parasites towards either the natural fauna or human visitors. However, human presence in Antarctica, mainly through research and tourism, keeps increasing over time, potentially exposing visitors to zoonotic infections from Antarctic wildlife and environment. Most available literature to date has focused on faecal samples from Antarctic vertebrates. Therefore, this study addressed the possible presence of parasites in Antarctic soil that may be infectious to humans. Soil samples were obtained from five locations on Signy Island (South Orkney Islands, maritime Antarctic), namely North Point and Gourlay Peninsula (penguin rookeries), Pumphouse (relic coal-powered pump house), Jane Col (barren high altitude fellfield) and Berntsen Point (low altitude vegetated fellfield close to current research station). Approximately 10% of the soil samples (14/135) from 3 out of the 5 study sites had parasites which included Diphyllobotridae spp. eggs, Cryptosporidium sp., an apicomplexan protozoa (gregarine), Toxoplasma gondii, helminths (a cestode, Tetrabothrius sp., and a nematode larva) and mites. The presence of parasites in the 3 sites are most likely due to the presence of animal and human activities as two of these sites are penguin rookeries (North Point and Gourlay Peninsula) while the third site (Pumphouse Lake) has human activity. While some of the parasite species found in the soil samples appear to be distinctive, there were also parasites such as Cryptosporidium and Toxoplasma gondii that have a global distribution and are potentially pathogenic.

Parasites in soil samples from Signy island, Antarctica

@#Studies on parasite populations in Antarctic soils are scarce and thus little is known about the threat of these parasites towards either the natural fauna or human visitors. However, human presence in Antarctica, mainly through research and tourism, keeps increasing over time, potentially exposing visitors to zoonotic infections from Antarctic wildlife and environment. Most available literature to date has focused on faecal samples from Antarctic vertebrates. Therefore, this study addressed the possible presence of parasites in Antarctic soil that may be infectious to humans. Soil samples were obtained from five locations on Signy Island (South Orkney Islands, maritime Antarctic), namely North Point and Gourlay Peninsula (penguin rookeries), Pumphouse (relic coal-powered pump house), Jane Col (barren high altitude fellfield) and Berntsen Point (low altitude vegetated fellfield close to current research station). Approximately 10% of the soil samples (14/135) from 3 out of the 5 study sites had parasites which included Diphyllobotridae spp. eggs, Cryptosporidium sp., an apicomplexan protozoa (gregarine), Toxoplasma gondii, helminths (a cestode, Tetrabothrius sp., and a nematode larva) and mites. The presence of parasites in the 3 sites are most likely due to the presence of animal and human activities as two of these sites are penguin rookeries (North Point and Gourlay Peninsula) while the third site (Pumphouse Lake) has human activity. While some of the parasite species found in the soil samples appear to be distinctive, there were also parasites such as Cryptosporidium and Toxoplasma gondii that have a global distribution and are potentially pathogenic.

Detection of dengue viruses and Wolbachia in Aedes aegypti and Aedes albopictus larvae from four urban localities in Kuala Lumpur, Malaysia.

Dengue fever (DF) is currently one of the most important mosquito-borne diseases that affects humans. Dengue fever (DF) and dengue hemorrhagic fever (DHF) are caused by four serotypes of dengue viruses (DENV-1 to DENV-4). The main vector transmitting dengue is Aedes aegypti while Aedes albopictus acts as a secondary vector. As treatment is unavailable and the first dengue vaccine approved in Mexico, Dengvaxia® has yet to be accepted worldwide, prevention of the disease relies heavily on surveillance and control of mosquito vectors. A transgene driver, Wolbachia was found to limit the transmission of dengue virus in Aedes mosquitoes. Wolbachia alone was able to inhibit viral replication, dissemination and transmission in A. aeygpti mosquitoes in experimental studies. In A. albopictus, Wolbachia did not affect the replication of dengue virus but was able to reduce the viral infection of mosquito salivary glands and limit transmission. Studies on Wolbachia have all been carried out in adult Aedes mosquitoes, hence this study was conducted to determine the presence of dengue virus serotypes and Wolbachia in A. aegypti and A. albopictus larvae collected from ovitraps in four localities in Kuala Lumpur viz. Happy Gardens, IMU Bukit Jalil, Ampang and Taman Yarl. Another objective of this study was to determine the association between dengue virus serotypes and the presence of Wolbachia in A. aegypti and A. albopictus larvae. A total of 300 mosquito larvae was collected; 99 (Happy Gardens), 85 (Bukit Jalil), 73 (Ampang) and 43 (Taman Yarl). Out of 300 larvae collected, 284 were identified as A. albopictus and 16 others were identified as A. aegypti. Of the 284 A. albopictus larvae collected, 211 (74.3%) and 73 (25.7%) were found to be negative and positive for dengue virus respectively. The dengue serotypes detected were 2 DENV-2 (2.7%), 58 DENV-3 (79.5%) and 13 DENV-4 (17.8%). DENV-1 was not detected in any of the A. albopictus larvae. For A. aegypti, out of 16 A. aegypti larvae collected, 12 (75%) were found to be negative and 4 (25%) were positive for DENV-2. For the detection of Wolbachia in A. albopictus, 71 out of 284 (25%) and 213 (75%) larvae were found to be positive and negative for Wolbachia respectively. For A. aegypti, 4 (25%) and 12 (75%) out of 16 larvae were positive and negative for Wolbachia respectively. This is the first report of Wolbachia in A. albopictus and A. aegypti larvae in Malaysia. A chisquare test analysis to determine the association between dengue virus and Wolbachia in A. albopictus and A. aegypti larvae collected from the four localities in Kuala Lumpur showed that there was no association (χ2 = 3.080; df = 1; P > 0.05).

Field evaluation of a rapid diagnostic test to detect antibodies in human toxocariasis.

Human toxocariasis which is caused mainly by the larvae of Toxocara canis and Toxocara cati, is a worldwide zoonotic disease that can be a potentially serious human infection. The enzyme-linked immunosorbent assay (ELISA) using T. canis excretory-secretory (TES) antigens harvested from T. canis larvae is currently the serological test for confirming toxocariasis. An alternative to producing large amounts of Toxocara TES and improved diagnosis for toxocariasis is through the development of highly specific recombinant antigens such as the T. canis second stage larva excretory-secretory 30 kDa protein (recTES-30). The aim of this study was to evaluate the sensitivity and specificity of a rapid diagnostic kit (RDT, named as iToxocara kit) in comparison to recTES-30 ELISA in Serendah Orang Asli village in Selangor, Malaysia. A total of 133 subjects were included in the study. The overall prevalence rates by ELISA and RDT were 29.3% and 33.1%, respectively, with more positive cases detected in males than females. However, no association was found between toxocariasis and gender or age. The percentage sensitivity, specificity, positive predictive value and negative predictive value of RDT were 85.7%, 90.1%, 80% and 93.2%, respectively. The prevalence for toxocariasis in this population using both ELISA and RDT was 27.1% (36/133) and the K-concordance test suggested good agreement of the two tests with a Cohen's kappa of 0.722, P<0.01. In addition, the followed-up Spearman rank correlation showed a moderately high correlation at R=0.704 and P<0.01. In conclusion, the RDT kit was faster and easier to use than an ELISA and is useful for the laboratory diagnosis of hospitalized cases of toxocariasis.

Isolation and identification of mites associated with raw and commercial farm edible bird nests.

The global demand for edible bird nests (EBNs) is high, especially from Hong Kong and Peoples Republic of China. Recently, this industry was greatly affected when China banned the import of all the EBNs from Malaysia (except for canned version) due to detection of high levels of nitrites. Several cases of anaphylaxis following ingestion of EBNs were reported. The source(s) of these allergens remain unknown. Mites have been reported to trigger allergic responses. Hence, this study was designed to quantify, isolate and identify the mites that are associated with EBNs. The raw EBNs were purchased from swiftlet farms in five locations in Peninsular Malaysia while the commercial nests were purchased from five different Chinese traditional medicinal shops. The average mite density of all the raw nests was 285 ± 603 mites per gram of EBN while the commercial nests had a much lower mean value of 21 ± 32 mites per gram of EBN (p = 0.082). Among the raw EBNs, the nests from Kajang had the highest average mite density (946 ± 1443 mites/g of EBN) whereas the nests from Kuala Sanglang had the lowest (54 ± 34 mites/g of EBN). Among the commercial EBNs, the nests from Company D had the highest average mite density (76 ± 18 mites/g of EBN) whereas the nests from Company A were free of mites. Overall, the average densities of mites in the raw nests obtained from southern regions of Malaysia (Selangor and Johor) were higher than those nests obtained from the northern regions (Kedah and Kelantan). Thirty types of mites were isolated from both the raw and commercial nests. Among these, some are probably feather mites (Eustathia cultrifer, Pteroherpus garrulacis, Pterodectes amaurochalinus, Laminalloptes sp., Berlesella alata and Neochauliacia sp.), house dust and storage mites (Suidasia sp., Austroglycyphagus sp., and Aleuroglyphus ovatus), mesostigmatid mites (Dermanyssus sp.), prostigmatid mites (Cheyletus sp., tarsonemid and cunaxid mites), astigmatid mites (Collocalidectes sp., Streetacarus sp. and Hemisarcoptes sp.) and oribatid mites. This study provides baseline information on the density and type of mites that are probably associated with EBNs. This study also heightens the importance of mites as a possible source of EBN-associated anaphylaxis.

Structural analysis of raw and commercial farm edible bird nests.

Edible bird nests (EBNs) are consumed worldwide for various health benefits. EBNs are nests built from the saliva of swiftlets of Aerodramus species. The global market for EBNs is on the rise, especially from Hong Kong and mainland China. In the past, EBNs were harvested mainly from natural caves; however in the recent years, there has been a rapid growth of swiftlet farming. Little is known about the actual composition of EBNs except for protein, carbohydrate, ash and lipid contents, amino acids, vitamins and macro/ micronutrients. Besides the biochemical components of EBNs, are there any other structures that are associated with EBNs? This paper reports on the structural analysis of raw unprocessed farm and processed commercial EBNs. The raw EBNs were purchased from swiftlet farms in five locations in Peninsula Malaysia: Kuala Sanglang (Perlis; 6° 16' 0"N, 100° 12' 0"E), Pantai Remis (Perak; 4º 27' 0" N, 100º 38' 0" E), Kluang (Johor; 02º 012 303N 103º 192 583E), Kajang (Selangor; 2º 59' 0"N, 101º 47' 0"E) and Kota Bharu (Kelantan; 6º 8' 0"N, 102º 15' 0"E). The commercial nests were purchased from five different Chinese traditional medicinal shops (Companies A-E). A portion of each EBN was randomly broken into small fragments, attached to carbon tape and coated with gold and palladium particles for examination and photography under a scanning electron microscope. Structural analysis revealed the presence of mites, fungi, bacteria and feather strands on both the raw and commercial nests. Mite eggshells and faecal pellets, and body parts of other arthropods were seen only in the raw nests. The commercial nests had a variety of unidentified structures and substances coated on the nests' surfaces that were not found on the raw nests. The presence of these contaminants may jeopardise the quality of EBNs and pose health risks to consumers. Further identification of the mites and their allergens, fungi and bacteria are on-going and will be reported separately.

The influence of deep frying using various vegetable oils on acrylamide formation in sweet potato (Ipomoea batatas L. Lam) chips.

The objective of this study was to evaluate the precursors of acrylamide formation in sweet potato (SP) (Ipomoea batatas L. Lam) chips and to determine the effect of different types of vegetable oils (VOs), that is, palm olein, coconut oil, canola oil, and soya bean oil, on acrylamide formation. The reducing sugars and amino acids in the SP slices were analyzed, and the acrylamide concentrations of SP chips were measured. SP chips that were fried in a lower degree of unsaturation oils contained a lower acrylamide concentration (1443 µg/kg), whereas those fried with higher degree of unsaturated oils contained a higher acrylamide concentration (2019 µg/kg). SP roots were found to contain acrylamide precursors, that is, 4.17 mg/g glucose and 5.05 mg/g fructose, and 1.63 mg/g free asparagine. The type of VO and condition used for frying, significantly influenced acrylamide formation. This study clearly indicates that the contribution of lipids in the formation of acrylamide should not be neglected.

Personalizing Stem Cell Research and Therapy: The Arduous Road Ahead or Missed Opportunity?

The euphoria of stem cell therapy has diminished, allowing scientists, clinicians and the general public to seriously re-examine how and what types of stem cells would effectively repair damaged tissue, prevent further tissue damage and/or replace lost cells. Importantly, there is a growing recognition that there are substantial person-to-person differences in the outcome of stem cell therapy. Even though the small molecule pharmaceuticals have long remained a primary focus of the personalized medicine research, individualized or targeted use of stem cells to suit a particular individual could help forecast potential failures of the therapy or identify, early on, the individuals who might benefit from stem cell interventions. This would however demand collaboration among several specialties such as pharmacology, immunology, genomics and transplantation medicine. Such transdisciplinary work could also inform how best to achieve efficient and predictable stem cell migration to sites of tissue damage, thereby facilitating tissue repair. This paper discusses the possibility of polarizing immune responses to rationalize and individualize therapy with stem cell interventions, since generalized "one-size-fits-all" therapy is difficult to achieve in the face of the diverse complexities posed by stem cell biology. We also present the challenges to stem cell delivery in the context of the host related factors. Although we focus on the mesenchymal stem cells in this paper, the overarching rationale can be extrapolated to other types of stem cells as well. Hence, the broader purpose of this paper is to initiate a dialogue within the personalized medicine community by expanding the scope of inquiry in the field from pharmaceuticals to stem cells and related cell-based health interventions.

Neurogenesis: role for microRNAs and mesenchymal stem cells in pathological states.

Implantation of adult human mesenchymal stem cells (MSCs) to treat neural disorders shows promise. Depending on their microenvironment, MSCs could potentially be used for the repair and/or replacement of neurons in traumatic brain injury or the treatment of Parkinson's disease. This cross-disciplinary review incorporates aspects of neuroscience, stem cell biology, cancer biology and immunology to discuss interactions between inflammatory mediators and MSCs. We first discuss the role of microRNAs (miRNAs) in neurological development. Secondly, we discuss the ability of MSCs to transdifferentiate into functional neurons, which are regulated by miRNAs, and the implications of these cells for the therapy of neuropathological states. The administration of effective and safe MSC therapy must acknowledge immune mediators that may predispose the early differentiating MSCs to oncogenic insults. Thus, we discuss a key gene, RE-1 silencing transcription factor (REST), based on its dual role in neurogenesis and cancer development. Immune mediators could be central to MSC responses within a region of tissue injury and are also discussed in detail. Exploring the predisposition of MSCs to oncogenesis is critical for translational science since the implementation of safeguarding measures prior to therapy can lead to the successful delivery of stem cells to patients. The method by which MSCs could be applied for future therapies might require trans-disciplinary approaches for personalized treatments.

Fourier transform ultraviolet-visible spectrometer based on a beam-folding technique.

A beam-folding technique in optical interferometry, where the number of beam folds used can be very large, is reported. This technique can be used as a low-cost position-tracking method in a Fourier transform spectrometer (FTS) to cover the broad spectral range from UV to IR. The main advantage gained is the simple position-tracking algorithm used in sampling the interferogram. We have developed a UV-visible FTS, whose wavelength coverage is limited only by the optical elements (350 nm(-1) microm with off-the-shelf components). Preliminary results show that it can achieve a resolution of approximately 4 cm(-1) even with a ball-bearing translation stage.

Flavonoids from Blumea balsamifera.

3,4',5-Trihydroxy-3',7-dimethoxyflavanone was isolated from the ligroin extract of the leaves of Blumea balsamifera, while the acetone extract yielded 3',4',5-trihydroxy-7-methoxyflavanone and a new biflavonoid identifed as 3-O-7''-biluteolin (1). The isolation of 1 is significant since a biflavonoid with a C-O-C linkage of the type [I-3-O-II-7] has not been previously reported from a plant.

Development of a highly specific recombinant Toxocara canis second-stage larva excretory-secretory antigen for immunodiagnosis of human toxocariasis.

The specificity of the recombinant Toxocara canis antigen developed for the immunodiagnosis of human toxocariasis was compared with that of the excretory-secretory antigen from T. canis second-stage larvae (TES) by enzyme-linked immunosorbent assay. A total of 153 human serum samples from patients infected with 20 different helminths, including 11 cases of toxocariasis, were examined. No false-negative reactions were observed for the toxocariasis cases. When the TES was used at concentrations of 0.5 and 0.125 microg/ml, cross-reactions were observed in 79 (55.6%) and 61 (43.0%) of 142 cases, respectively. In contrast, when the recombinant antigen was tested at a concentration of 0.5 microg/ml, cross-reactions were observed in 19 (13.4%) of 142 cases. At a concentration of 0.125 microg/ml, however, the cross-reaction rate decreased sharply to only 2.1%, corresponding to 3 of 142 cases. The cross-reactions occurred with one case each of gnathostomiasis, paragonimiasis with Paragonimus miyazakii, and spirometriasis, in which high antibody titers were detected. In addition, the recombinant antigen showed negative reactions with serum samples from patients infected with Ascaris and hookworms, which are the most common parasites in the world. These findings are also supported by experiments with animals infected with Ascaris and hookworm. From these results, the recombinant antigen is highly specific for toxocariasis and may provide more reliable diagnostic results than other methods.

Effects of insulin-like growth factors I and II on oestrone sulphatase activity in human breast cancer cell lines.

Oestrogens play an important role in the development of breast cancer. A very important source of active oestrogens in the breast is oestrone sulphate which is converted to oestrone by oestrone sulphatase. The aim of this study was to assess the effects of IGF-I and IGF-II on oestrone sulphatase activity in, as well as cell growth of, MCF-7 and MDA-MB-231 human breast cancer cell lines. Cells were grown in supplemented DMEM and treated with varying concentrations of IGFs. At the end of the treatment period, intact cell monolayers were washed and assayed for oestrone sulphatase activity and the number of cell nuclei determined on a Coulter Counter. Oestrone sulphatase activity was significantly stimulated by IGF-I and II at concentrations of 100 ng/ml and 200 ng/ml in MCF-7 cells. IGF-I had no effect on oestrone sulphatase activity in MDA-MB-231 cells over the range of concentrations tested. Significant inhibition of oestrone sulphatase was observed in MDA-MB-231 cells at higher concentrations of IGF-II (50 ng/ml, 100 ng/ml and 200 ng/ml). Both IGF-I and IGF-II at higher concentrations (100 ng/ml and 200 ng/ml) significantly inhibited MCF-7 and stimulated MDA-MB-231 cell growth. Since IGF-I and II have effects on cell growth and oestrone sulphatase activity in breast cancer cell lines they may play a role in the development and progression of human breast cancer.

Effect of transforming growth factor-beta1 on oestrogen metabolism in MCF-7 and MDA-MB-231 breast cancer cell lines.

Transforming growth factor-beta (TGF-beta) has been shown to inhibit the growth of mammary epithelial cells and may play a protective role in mammary carcinogenesis. In contrast, oestrogens promote the development of breast cancer. Oestrone sulphate (E1S) is a huge reservoir of active oestrogens in the breast being converted to the weak oestrogen, oestrone (E1), by oestrone sulphatase. E1 is reversibly converted by oestradiol-17beta hydroxysteroid dehydrogenase to the potent oestrogen, oestradiol (E2). The aim of this study was to assess the effect of the TGF-beta1 isoform on growth and oestrogen metabolism in the hormone-dependent MCF-7 and hormone-independent MDA-MB-231 human breast cancer cell lines. The results showed that TGF-beta1 significantly inhibited cell growth and stimulated the conversion of E1S to E1 and E1 to E2 in the MCF-7 cell line. In the MDA-MB-231 cell line TGF-beta1 significantly stimulated cell growth and inhibited the interconversions between E1 and E2. In conclusion, the growth inhibitory effect of TGF-beta1 on the MCF-7 cell line would appear to confer a protective effect in breast cancer. However, its ability to increase the amount of E2 would increase the risk of breast cancer. Which of these effects predominates in vivo remains to be explored. The growth stimulatory effect of TGF-beta1 on the MDA-MB-231 cell line probably acts through a mechanism independent of the effect of TGF-beta1 on oestrogen concentrations since this cell line is hormone unresponsive.