1.Sero-prevalence study of IgE responses to allergens from Malaysian house dust (HDM) and storage mites (SM)
Chong, K.T., Wong, S.F., Mak, J.W., Loh, L.C., Ho, T.M.
Tropical Biomedicine 2015;32(3):524-539
Allergens of Dermatophagoides and Blomia species are well-characterized but
not for other species. This study was conducted to determine the prevalence of allergic
sensitization to house dust (HDM) and storage mites (SM). One hundred adult subjects (aged
> 18) were recruited. The mite specific IgE of all allergic subjects were higher compared with
healthy subjetcs despite being not statistically significant except for D. farinae and G.
malaysiensis. The mean serum IgE levels against HDM and SM for allergic subjects were
significantly higher compared with those in healthy subjects. They were mainly sensitized to
Dermatophagoides farinae (35%) and Glycycometus malaysiensis (37%). Immunoblots revealed
not all allergic subjects showed positive immuno-reactivity against the mites tested. Single or
multiple bands were observed for different species. The subjects were commonly sensitized
to Group 2 (9-12 kDa), 10 (38 kDa) and 18 (40-48 kDa) allergens. Twenty-one out of 60 allergic
subjects were sensitized to either one or more species. The majority of them (71%) were
sensitized to single species. The allergic subjects were mainly sensitized to D. pteronyssinus,
followed by Tyrophagus putrecentiae and Aleuroglyphus ovatus. Seven were solely sensitized
to HDM while 10 were solely sensitized to SM. Four subjects were sensitized to both. Preadsorption
study revealed no cross-reactivity. There was difference between the prevalence
and reactivity to allergens of HDM and SM in these subjects. Both ELISA and immunoblot did
not correlate well but can complement each other in improving the detection of mite allergens
to the species level.
2.Histopathology of Brugia pahangi and Plasmodium berghei ANKA co-infection in the Gerbil (Meriones unguiculatus)
Junaid, O.Q ; Wong, K.T ; Khaw, L.T. ; Mahmud, R. ; Vythilingam, I.
Tropical Biomedicine 2018;35(4):981-998
Co-infection with multiple different parasites is a common phenomenon in both
human and animals. Among parasites that frequently co-infect the same hosts, are the
filarial worms and malaria parasites. Despite this, the mechanisms underlying the
interactions between these parasites is still relatively unexplored with very few studies
available on the resulting pathologies due to co-infection by filarial nematodes and malaria
parasites. Hence, this study investigated the histopathological effect of Brugia pahangi
and Plasmodium berghei ANKA (PbA) infections in gerbil host. Gerbils grouped into B.
pahangi-infected, PbA-infected, B. pahangi and PbA-coinfected, and uninfected control,
were necropsied at different time points of post PbA infections. Brugia pahangi infections
in the gerbils were first initiated by subcutaneous inoculation of 50 infective larvae, while
PbA infections were done by intraperitoneal injection of 106 parasitized red blood cells
after 70 days patent period of B. pahangi. Organs such as the lungs, kidneys, spleen, heart
and liver were harvested aseptically at the point of necropsy. There was significant
hepatosplenomegaly observed in both PbA-infected only and coinfected gerbils. The spleen,
liver and lungs were heavily pigmented. Both B. pahangi and PbA infections (mono and coinfections)
resulted in pulmonary edema, while glomerulonephritis was associated with
PbA infections. The presence of both parasites induced extramedullary hematopoiesis in
the spleen and liver. These findings suggest that the pathologies associated with coinfected
gerbils were synergistically induced by both B. pahangi and PbA infections.
3.In vitro antiviral activity of medicinal mushroom Ganoderma neo-japonicum Imazeki against enteroviruses that caused hand, foot and mouth disease
Ang, W.X. ; Sarasvathy, S. ; Kuppusamy, U.R. ; Sabaratnam, V. ; Tan, S.H. ; Wong, K.T. ; Perera, D. ; Ong, K.C.
Tropical Biomedicine 2021;38(No.3):239-247
Hand, foot and mouth disease (HFMD) is a highly contagious viral disease that predominantly affects children younger than 5 years old. HFMD is primarily caused by enterovirus A71 (EVA71) and coxsackievirus A16 (CV-A16). However, coxsackievirus A10 (CV-A10) and coxsackievirus A6 (CV-A6) are being increasingly reported as the predominant causative of HFMD outbreaks worldwide since the past decade. To date, there are still no licensed multivalent vaccines or antiviral drugs targeting enteroviruses that cause HFMD, despite HFMD outbreaks are still being frequently reported, especially in Asia-Pacific countries. The high rate of transmission, morbidity and potential neurological complications of HFMD is indeed making the development of broad-spectrum antiviral drugs/agents against these enteroviruses a compelling need. In this study, we have investigated the in vitro antiviral effect of 4 Ganoderma neo-japonicum Imazeki (GNJI) crude extracts (S1-S4) against EV-A71, CV-A16, CV-A10 and CV-A6. GNJI is a medicinal mushroom that can be found growing saprophytically on decaying bamboo clumps in Malaysian forests. The antiviral effects of this medicinal mushroom were determined using cytopathic inhibition and virus titration assays. The S2 (1.25 mg/ml) hot aqueous extract demonstrated the highest broad-spectrum antiviral activity against all tested enteroviruses in human primary oral fibroblast cells. Replication of EV-A71, CV-A16 and CVA10 were effectively inhibited at 2 hours post-infection (hpi) to 72 hpi, except for CV-A6 which was only at 2 hpi. S2 also has virucidal activity against EV-A71. Polysaccharides isolated and purified from crude hot aqueous extract demonstrated similar antiviral activity as S2, suggesting that polysaccharides could be one of the active compounds responsible for the antiviral activity shown by S2. To our knowledge, this study demonstrates for the first time the ability of GNJI to inhibit enterovirus infection and replication. Thus, GNJI is potential to be further developed as an antiviral agent against enteroviruses that caused HFMD.