Asian Pacific Journal of Tropical Medicine

1-5

Authors: Nitwara Wikan, Duncan R. Smith

Phylogenic evidence suggests that the strain of Zika virus causing an unprecedented outbreak of disease in the Americas had its origin in Southeast Asia, where reports of isolated cases of Zika virus infection have occurred since 2010. Why there has been no large outbreak of Zika infection in Southeast Asia remains unclear and whether such an outbreak will occur in the future is a question of significant concern. This review looks at Zika virus from a Southeast Asian perspective and highlights some of the possible scenarios with regards to Zika virus in this part of the world as well as highlighting some of the research questions that need to be urgently addressed.

11-14

Authors: Supawat Chatchen, Arunee Sabchareon, Chukiat Sirivichayakul

Dengue virus (DENV) is a mosquito-transmitted virus that is expanding across the world. The incidence of dengue infection, especially severe disease, has been increasing. DENV consist of 4 serotypes of single stranded RNA viruses (D1–D4) in the genus Flavivirus, family Flaviviridae. Majority of dengue infections are asymptomatic cases, which cause difficulty in disease control and are important in dengue surveillance. There is still no gold standard to diagnose asymptomatic dengue infection. Plaque reduction neutralization test (PRNT) has been developed for many purposes such as immunological study, clinical study, vaccine trial and is currently the most sensitive and specific method for serological surveillance. However, PRNT shows some degree of cross reaction among different dengue serotypes especially secondary dengue infection cases and to other flaviviruses. Moreover, various modification since the beginning make PRNT lack of inter-laboratory standardization which is an important issue. This paper

20-24

Authors: Pimwan Thongdee, Kesara Na-Bangchang

Objective To investigate the role of human host heme-oxygenase-1 (HO-1) in pathogenesis of cerebral malaria in the in vitro model. Methods The effect of human host HO-1 [human brain microvascular endothelial cell (HBMEC)] on hemoglobin degradation in the co-culture model of HBMEC and ITG Plasmodium falciparum-infected red cells (iRBC) through measurement of the enzymatic products iron and bilirubin. Results Following exposure to the HO-1 inducer CoPPIX at all concentrations, the HBMEC cells apoptosis occurred, which could be prominently observed at 15 μM of 3 h exposure. In contrast, there was no significant change in the morphology in the non-exposed iRBC at all concentrations and exposure time. This observation was in agreement with the levels of the enzymatic degradation products iron and bilirubin, of which the highest levels (106.03 and 1753.54% of baseline level, respectively) were observed at 15 μM vs. 20 μM at 3 h vs. 24 h exposure. For the effect of the HO-1 inhibitor ZnPPIX, HBMEC cell morphology was mostly unchanged, but significant inhibitory effect on cell apoptosis was seen at 10 μM for the exposure period of 3 h (37.17% of baseline level). The degree of the inhibitory effect as reflected by the level of iron produced was not clearly observed (highest effect at 10 μM and 3 h exposure). Conclusions Results provide at least in part, insight into the contribution of HO-1 on CM pathogenesis and need to be confirmed in animal model.

35-41

Authors: Wilasinee Suwanjang, Bongkot Khongniam, Sujittra Srisung, Supaluk Prachayasittikul, Virapong Prachayasittikul

Objective To investigate protective effects of Spilanthes acmella (S. acmella) Murr. extracts against pesticide-induced neuronal cells death and to elucidate the underlying molecular mechanism in dopaminergic (SH-SY5Y) cells lines. Methods Cell viability of SH-SY5Y cells was studied by treating the cells with various concentration of pirimicarb for 24 h. Neuroprotective effect of S. acmella Murr. extracts was investigated by adding the plant extracts to the medium for 24 h prior to the incubation with 100 μM H2O2 or with pirimicarb for 24 h. Control-untreated cells were incubated with the culture medium. Cell viability was measured by MTT assay, calpain and calpastatin expressions were analyzed by Western blotting and immunocytochemistry. Results Pretreatment of SH-SY5Y cells with S. acmella Murr. extracts (1 μg/mL) for 24 h significantly increased the dopaminergic neurons in pirimicarb-induced neurotoxicity. In addition, pretreatment with the S. acmella Murr. extracts led to decreased calpain but increased calpastatin protein levels. Conclusion S. acmella Murr. extracts exerted neuroprotective effect, via an alteration of calcium homeostasis, against pirimicarb induced neurotoxicity. The S. acmella Murr. might be a potential natural candidate with neuroprotective activity.

47-51

Authors: Zhong Han, Xia-Ling Lei, Hong Zhang, Lu Liu, Zhi-Sen Chen, Wei Yang, Zhao-Rong Lun

Objective To access the toxicity of forsythin from Forsythia suspensa leaves and evaluate its safety. Methods Acute toxicity was determined by oral administration of a single dose of 18 100 mg/kg forsythin in NIH mice. Sub-chronic toxicity was evaluated by oral administration of several doses of forsythin for 30 days at does of 0, 540, 1 620, and 6 480 mg/kg in SD rats. Results In the acute toxicity study, mortality was not observed after 14 days. In addition, clinically relevant adverse effects, or variations in body weight or food consumption were not observed. Similarly, after 30 days in the sub-chronic toxicity study, no mortality or significant toxicological effects such as decreased food consumption, body weight, biochemical parameters and vital organs etc. were noticed. Conclusion The results revealed that the forsythin from Forsythia suspensa leaves has low or no toxicity via oral administration, and therefore is suitable for further development and applications.

57-63

Authors: Walter Chingwaru, Jerneja Vidmar

Objective To evaluate the potential of commercial fermented products sold in the country, and strains of Lactobacillus plantarum (L. plantarum) as prophylaxis and therapy against diarrhoea in children. Methods The antimicrobial potential of cultures of lactobacilli enriched from 4 Zimbabwean commercial food/beverage products: Dairibord Lacto sour milk (DLSM), Probrand sour milk (PSM), Kefalos Vuka cheese (KVC) and Chibuku opaque beer (COB); and four strains of L. plantarum obtained from Balkan traditional cheeses against clinical strains of Escherichia coli (E. coli) was assayed using the well diffusion method. Three commercial paediatric antidiarrhoeal drug products: Biogaia (BG), Prolife (PL) and Probio Junior (PJ) and a mutant strain of E. coli [strain 11105 (ATCC) – a vitamin B-12 auxotroph and penicillin G acylase-producing strain] were used as controls. An agar diffusion assay and a competitive exclusion assay were carried out on Mueller Hinton agar. Results Crude cultures of putative lactobacillus strains obtained from Zimbabwean dairy products (Probrand sour milk, Kefalos Vuka vuka cheese and Chibuku opaque beer) had significantly higher antimicrobial activities against clinical strains of E. coli than strains of L. plantarum isolated from Balkan cheeses (CLP1, CLP2 or CLP3) and crude microbial cultures from commercial paediatric probiotic products (BG, PJ and PL) of a culture of Lactobacillus rhamnosus LGG (P < 0.05). Conclusions The putative Lactobacilli from four commercial Zimbabwean dairy products (Probrand sour milk, Kefalos Vuka vuka cheese and Chibuku opaque beer), and three strains of L. plantarum from Balkan cheeses (CLP1, CLP2 or CLP3) exhibited high antibacterial activities that can be harnessed to control paediatric diarrhoea that is caused by pathogenic strains of E. coli. Studies to characterise the probiotic potential of the live cultures in the products and the new strains of L. plantarum are underway.

69-74

Authors: Sun Hyoung Park, Dong Hun Lee, Jang Yong Jin, Young-Lim Shin, Meeyong Shin, Sung Shin Kim, Won Suk Suh, Jae Ock Park, Yong Hee Hong

Objective To identify the source of infection and determine the clinical features and laboratory finding of measles infection. Methods In 27 measles patients, except for 3 adult patients, the rest of 24 pediatric measles cases were analyzed with regard to age, sex, immunization status, transmission routes and molecular genotyping of measles virus. Eighteen measles patients who admitted in isolation ward were set apart to investigate clinical findings and its correlation with laboratory characteristics. Retrospective analysis of cases was conducted in this study. Results Of the 24 pediatric patients, 23 (95.8%) had not received any measles-containing vaccine (MCV). Sixteen of the patients (66.7%) were aged <12 months. The suspicious index case of a girl aged 34 months was not vaccinated with MCV1 and got measles after a trip to Philippines, and molecular genotype was revealed as B3. Measles outbreaks in the community such as a restaurant were followed by this one imported case. According to analysis of 18 patients admitted in isolation ward, the median level of C-reactive protein (CRP) was 0.38 mg/dL and that of lactate dehydrogenase (LDH) was 1200 IU/L. All of the 18 patients had LDH levels above the normal range. Age correlated with CRP (ρ = 0.528, P = 0.024) and LDH (ρ = 0.501, P = 0.034). The duration of fever was correlated with the duration of fever before rash (ρ = 0.898, P < 0.01). The duration of hospitalization was correlated with CRP (ρ = 0.586, P = 0.011). The white blood cell counts were correlated with the levels of LDH (ρ = 0.505, P = 0.033), aspartate aminotransferase (ρ = 0.507, P = 0.032), and alanine aminotransferase (ρ = 0.481, P = 0.043). Conclusions Early weaning of maternally derived measles antibodies therefore vaccination of MCV1 at a young age from 9 months to 12 months should be considered in situations of early exposure. Furthermore, there is a call for consideration of scheduling an earlier age for the first dose of MMR vaccine in Europe. It is necessary for Korea to investigate the duration of the presence and quantitative analysis of maternal measles antibodies in infants and to reconsider the timing of MCV1.

79-86

Authors: Mehdi Sharafi, Haleh Ghaem, Hamid Reza Tabatabaee, Hossein Faramarzi

Objective To predict the trend of cutaneous leishmaniasis and assess the relationship between the disease trend and weather variables in south of Fars province using Seasonal Autoregressive Integrated Moving Average (SARIMA) model. Methods The trend of cutaneous leishmaniasis was predicted using Mini tab software and SARIMA model. Besides, information about the disease and weather conditions was collected monthly based on time series design during January 2010 to March 2016. Moreover, various SARIMA models were assessed and the best one was selected. Then, the model's fitness was evaluated based on normality of the residuals' distribution, correspondence between the fitted and real amounts, and calculation of Akaike Information Criteria (AIC) and Bayesian Information Criteria (BIC). Results The study results indicated that SARIMA model (4,1,4)(0,1,0)(12) in general and SARIMA model (4,1,4)(0,1,1)(12) in below and above 15 years age groups could appropriately predict the disease trend in the study area. Moreover, temperature with a three-month delay (lag3) increased the disease trend, rainfall with a four-month delay (lag4) decreased the disease trend, and rainfall with a nine-month delay (lag9) increased the disease trend. Conclusions Based on the results, leishmaniasis follows a descending trend in the study area in case drought condition continues, SARIMA models can suitably measure the disease trend, and the disease follows a seasonal trend.

92-97

Authors: Yu Yang, Jia-Xiang Guo, Zhi-Qiang Shao

Objective To study whether miR-21 targets and inhibits tumor suppressor gene PTEN can promote prostate cancer cell proliferation and invasion. Methods Prostate cancer cell lines PC-3 were cultured and divided into negative control group (NC group), miR-21 group, pcDNA3.1 group, miR-21+pcDNA3.1 group and miR-21+PTEN group that were transfected with different miR and plasmid, respectively. After 12 h and 24 h of transfection, the cell viability and invasive cell number were determined; after 24 h of transfection, Bcl-2, Survivin, MMP2, MMP9, PTEN, PI3K, and AKT expression in cells were determined. Results After 12 h and 24 h of transfection, OD value and invasive cell number of miR-21 group were significantly higher than those of NC group; after 24 h of transfection, Bcl-2, Survivin, MMP2, MMP9, PI3K and AKT expression levels were significantly higher than those of NC group while PTEN expression level was significantly lower than that of NC group; after 12 h and 24 h of transfection, OD value and invasive cell number of miR-21+pcDNA3.1 group were significantly higher than those of pcDNA3.1 group, and the OD value and invasive cell number of miR-21+PTEN group were significantly lower than those of miR-21+pcDNA3.1 group; after 24 h of transfection, Bcl-2, Survivin, MMP2 and MMP9 content of miR-21+pcDNA3.1 group were significantly higher than those of pcDNA3.1 group, and Bcl-2, Survivin, MMP2 and MMP9 content of miR-21+PTEN group were significantly lower than those of miR-21+pcDNA3.1 group. Conclusions miR-21 can target and inhibit tumor suppressor gene PTEN expression to promote prostate cancer cell proliferation and invasion.

102-105

Authors: Jai-Wen Liu, Tzu-Chieh Lin, Yao-Tien Chang, Che-An Tsai, Sung-Yuan Hu

Prostatic abscess is a rare entity with an incidence of 0.5%–2.5% in all prostate diseases and usually occurs in the 5th and 6th decades of life with immunocompromised status. Prostatic abscess might be a process of evolution from acute prostatitis. Klebsiella pneumoniae is the leading microorganism in the diabetic patients of prostatic abscess in Taiwan. A 60-year-old diabetic man, with a one-week history of acute bacterial prostatitis was reported in this study, presenting to the emergency department with sudden altered mental status. The abdominal computed tomographic scan demonstrated lobulated prostatic abscess and multiple septic pulmonary emboli with lung abscesses. Analysis of cerebrospinal fluid showed white blood cells of 10 771 counts/mm3 with segmented neutrophils of 99%. Cultures of blood, cerebrospinal fluid and sputum yielded Klebsiella pneumoniae. We concluded that computed tomographic scan can make a definite diagnosis of prostatic abscess associated with complications and management with empiric antibiotics and adequate drainage is suggested.