Tropical biomedicine最新文献

Pro-and anti-inflammatory cytokines mediate the inflammatory response in sepsis. Therefore, regulation of cytokines with medications in risky situations may protect the patients from sepsis. Hydroxychloroquine and artemisinin are antimalarial drugs with immunomodulatory properties. In this study, we intended to investigate the effects of artemisinin and hydroxychloroquine on the cytokines released during sepsis in the rat model. Twenty-four rats were randomized into four groups. The control group received oral saline, the sepsis group received oral saline and intraperitoneal lipopolysaccharide toxin (LPS), the artemisinin-treated sepsis group received oral 33.33 mg/kg of artemisinin, and the hydroxychloroquinetreated sepsis group received oral 33.33 mg/kg of hydroxychloroquine before LPS injection. Three hours later, serum cytokines were measured. An increase was detected in TNF-a, IL-1, and IL-6 levels in the sepsis group compared to the control (p<0.01). Oral pretreatment with artemisinin resulted in significant downregulation only of IL-1 levels (p<0.01). Cytokines IL-1 and IL-6 were significantly downregulated in the serum of LPS-induced rats pretreated with oral hydroxychloroquine than rats with sepsis (p<0.01). Decreases observed in TNF-a and IL-10 levels were insignificant. These results demonstrated that both artemisinin and hydroxychloroquine attenuate the release of pro-inflammatory cytokines three hours after LPS-induced sepsis in rats. A significant decrease was observed in serum IL-1 and IL-6 levels with hydroxychloroquine and IL-1 levels with artemisinin. Based on our findings, we suggest that the therapeutic potential of artemisinin and hydroxychloroquine may be beneficial in preventing cytokine storm during sepsis, and further research is needed to determine the optimal timing of administration.

Newcastle disease (ND) is an extremely contagious and fatal viral disease causing huge economic losses to the poultry industry. Following recent ND outbreaks in Sabah in commercial poultry and backyard farms, it was speculated that this could be due to a new introduction of Newcastle Disease Virus (NDV) genotype/sub-genotype. Here we report the genetic characterization of NDVs isolated from Sabah during early 2021. All isolates were amplified and sequenced with primers specific to the viral fusion (F) gene using reverse transcription-polymerase chain reaction (RT-PCR). Nucleotide sequence analysis of the F gene showed that all isolates shared similar homology of 99.4% with NDV strain from Iran isolated in 2018. Amino acid sequences of the F protein cleavage site revealed the motif of ¹¹²RRQKRF¹¹⁷ indicating all isolates were of virulent strain. Phylogenetic analysis demonstrated that all isolates were clustered under sub-genotype VII 1.1 and clustered together with isolates from Iran (previously known as subgenotype VIIl). The present findings suggested that there is an emerging of a new sub-genotype into the poultry population in Sabah and this sub-genotype has never been reported before in Malaysia. Therefore, transboundary monitoring and continuous surveillance should be implemented for proper control and prevention of the disease. A further molecular epidemiological analysis of NDV is needed to well understand the circulatory patterns of virulent strains of NDV in the country to prevent future outbreaks.

The males of Simulium (Gomphostilbia) miblosi Takaoka in the S. epistum species-group, and S. (G.) apoense Takaoka in the S. ceylonicum species-group, both from Mindanao, the Philippines, are described for the first time. The male of S. (G.) miblosi is characterized by the hind tibia yellowish white on the basal three-fifths, elongate calcipala 1.5 times as long as its basal width, and ventral plate triangular ventrally (0.74 times as high as its greatest width) when viewed caudally. Tubercles on the frons and trichomes on the head and thorax of the pupa of this species are illustrated for the first time. The male of S. (G.) apoense is characterized by the small sensory vesicle 0.16-0.19 times as long as the third palpal segment, and enlarged hind basitarsus 1.0 and 1.2-1.3 times as wide as the hind tibia and femur, respectively. Taxonomic notes of these two species relevant to related species in each species-group are given.

Proteases of nematodes play a crucial role in larval molting and, in addition to their active role in egg hatching, proteases are also considered a crucial factor in tissue invasion and connective tissue remodeling. In Toxocara canis, proteases play important roles throughout the complex life cycle. They can degrade components of a model of extracellular matrix, basement membranes and different physiological substrates. In the present study, measurements of the proteolytic activity of the perivitelline fluid (PF) surrounding Toxocara canis embryos at different stages of development, the hatching fluid (HF) surrounding the infective larvae, as well as the excretory secretory (ES) products of the larvae in the culture media were performed. Measurements were made using casein as substrate following the Sigma non-specific protease activity assay. The results showed that enzyme activity increased as the embryo matured. The infective larvae were found to continuously produce proteases in the surrounding HF and ES products after in vitro cultivation indicating that Toxocara canis proteases might be important for the worm in the egg and the host. Optimal enzymatic activity was found at pH 8. Incubation of the antiserum from infected mice with the HF and ES products decreased their proteolytic activities, suggesting that there may be a link between the proteases present in these fluids and the immune response.

This study aimed to consider the in vitro and in vivo effects of the Stachys lavandulifolia methanolic extract (SLME) (2.5, 5, 10, 25, 50, 100 µg/mL) against Leishmania major infection. The in vitro antileishmanial effects of SLME was studies on promastigote and amastigote forms of L. major. The effect of SLME on the nitric oxide (NO) and apoptosis, secretion of Th1/2 cytokines, and infectivity rate in macrophages cells were also studies. The cytotoxicity of SLME on human (THP-1) and murine (J774-A1 cell) macrophage cells was investigated through the measuring the 50% cytotoxic concentrations (CC₅₀). Moreover, the in vivo effects of SLME for healing the cutaneous leishmaniasis (CL) lesions in infected BALB/c mice studied by assessing the lesions size and the parasite load during four weeks of treatment. The calculated 50% inhibitory concentration (IC₅₀) valuesfor SLME and meglumine antimoniate (MA) against the promastigote stage were 23.4 and 71.1 µg/mL, respectively. For amastigote stage, the IC₅₀ values for SLME and MA were 39.3 µg/mL and 44.3 µg/mL, respectively. Followed by 28 days' topically therapy with SLME at doses of 50 and 100 mg/kg/day, the CL lesions size as well as parasite load were significantly (p<0.001) reduced; such that the recovery percentage of the infected mice was 80% and 97% after treatment with SLME at the dose of 50 and 100 mg/kg, respectively. SLME also markedly induced the NO production and apoptosis; whereas decreased infection rate in macrophage cells. After incubation of infected macrophages with SLME, the level interferon gamma was meaningfully (p<0.001) elevated as a dose-dependent response; in contrast, release of interleukin 10 (IL-10) and IL-4 markedly (p<0.001) decreased. The CC₅₀ value for SLME against THP-1 and J774-A1 cell was 996.4 µg/mL and 741.3 µg/mL, respectively. The calculated selectivity index of >10 for SLME and MA confirmed their specificity to amastigotes and the low toxicity for macrophages. Our results showed the potent effects of SLME in eliminating and controlling Leishmania parasites in both in vitro and in vivo assays. Based on the current experimental study, SLME can be suggested as an alternative medicine for the isolation and production of a new agent for treating CL caused by L. major. Although, we found some cellular mechanisms of SLME against Leishmania parasites, but, additional surveys are necessary to specify the accurate mechanisms of action, toxicity, and its efficacy mainly in human subjects.

Lack of knowledge about the type and prevalence of gastrointestinal symptoms as a clinical manifestation is one of the reasons for delayed diagnosis and treatment of COVID-19 patients. This review study aimed to systematically review the type and prevalence of gastrointestinal symptoms in COVID-19 patients. To study the gastrointestinal manifestations of COVID-19, we used the 06- PRISMA registered in the CAMARADES-NC3Rs Preclinical Systematic Review and Meta-Analysis Facility (SyRF) database. PubMed, Embase, Web of Science, Google Scholar, and Scopus databases were searched for publications on the gastrointestinal manifestations of COVID-19 with no publication time frame. Articles were found using the following terms and search strategy: ["COVID-19, Coronavirus, 2019-nCoV, Clinical SymptomsGastrointestinal or gastric or intestinal manifestations"]. Out of 27652 papers, 35 papers on a total of 6730 COVID-19 patients up to 2022 met the inclusion criteria. Remarkably, most articles (28 papers, 77.8%) were from China (77.8%). The most common gastrointestinal manifestations were nausea or vomiting (13.1%), diarrhea (11.05%), anorexia (8.7%), and abdominal pain (2.4%), respectively. The findings of the present review revealed that contrary to what was initially assumed in the COVID-19 outbreak, this infection does not manifest only as respiratory symptoms but also as gastrointestinal symptoms. Therefore, clinicians and gastroenterologists must be alert to these unusual cases and fecal-oral transmission during the COVID-19 pandemic and implement preventive strategies.

The larvae of Echinococcus (hydatidcyst) can parasitize humans and animals, causing a serious zoonotic disease-echinococcosis. The life history of Echinococcus is complicated, and as the disease progresses slowly after infection, early diagnosis is difficult to establish. Due to the limitations of imaging and immunological diagnosis in this respect, domestic and foreign scholars have established a variety of molecular detection techniques for the pathogen Echinococcus over recent years, mainly including nested polymerase chain reaction (PCR), multiplex PCR, real-time quantitative PCR, and nucleic acid isothermal amplification technology. In this article, the research progress of molecular detection technology for Echinococcus infection currently was reviewed and the significance of these methods in the detection and diagnosis of hydatid and hydatid diseases was also discussed.

Coccidiosis is a major recurring problem in the poultry industry and is caused by infection of one or more of the seven Eimeria species known to infect chickens, with Eimeria tenella among the best studied and economically important. Studies on the genetic diversity of E. tenella strains is essential for the development of universally acceptable diagnostic markers and vaccines against the disease. Eimeria tenella internal transcribed spacer-1 (ITS-1) and apical membrane antigen-1 (AMA-1) sequences from different parts of the world are available in the public domain and therefore provide suitable comparative markers for genetic diversity study. In this study, the ITS-1 and AMA-1 sequence diversity of two local E. tenella strains, namely EtNSN6 and EtSGR6 were characterized. Both ITS-1 and AMA-1 sequences for EtNSN6 and EtSGR6 were retrieved by mapping to their respective genome sequences generated using next generation sequencing. Multiple sequence alignment of the ITS-1 and AMA-1 sequences with selected homologous sequences revealed the presence of a total of five and 13 single nucleotide polymorphisms (SNPs) respectively. All SNPs appeared to occur at random and did not show any unique pattern based on geographical regions while no insertions and deletions (indels) was found to occur in the aligned sequences. However, unique bases that defined certain strains were detected. Phylogenetics analyses performed with Maximum Parsimony (MP) and Maximum Likelihood (ML) methods revealed similar topology for the internal groups with all the E. tenella ITS-1 and AMA-1 sequences grouped in the same clade supported by high bootstrap confidence. This confirmed that both EtNSN6 and EtSGR6 samples are E. tenella strains. Sequence comparison and phylogenetics analyses further suggest the possibility of low genetic diversity among E. tenella strains.

Ae. aegypti is a dengue virus vector and a public health threat in Indonesia. Furthermore, the Dengue Haemoragic Fever (DHF) has spread to all cities in the country, including Bandar Lampung. A species distribution model, Maximum Entropy (MaxEnt), was used to predict the geographic distribution of this vector in three dengue-endemic areas, namely Sukarame, Kemiling, and Tanjung Seneng. Previously, surveillance was conducted to determine the presence of Ae. aegypti. Therefore, this study suggested that environmental variables such as rainfall, temperature, land cover, and population density have influenced the widespread of Ae. aegypti and facilitate its proliferation in the study areas. The influence of the environmental variables was analyzed using a response curve. The model performance was measured by percent contribution, the importance of permutations, and the jackknife test. This study's evaluation indicates that the certainty models for the presence of Ae. aegypti in Sukarame, Kemiling, and Tanjung Seneng were developed extremely well, with respective values of 0.989, 0.993, and 0.969. The results showed that Ae. aegypti is widespread in the three endemic areas. The high population density and land conversion into settlements are influential environmental variables essential in determining the distribution of the vector in three areas of Bandar Lampung. Climatic factors such as rainfall and temperature are supporting aspects in maintaining the habitat of Ae. aegypti in the area. Mapping areas at risk of this dengue vector can aid in planning disease management strategies and identifying priority locations for entomological surveys to control epidemics.

Many of the therapeutic effects of plant extracts and bioactive compounds appear related to their immunomodulatory effects and impact on the host immune system. The immune response is desirable to mitigate established infections and, in the case of severe malaria, is a feasible approach to dealing with the overwhelming cytokine response. Glycogen synthase kinase-3 (GSK3), a Ser/Thr kinase that is a central regulator of the cytokine response, is a promising antimalarial drug target. In this review, we discussed our ongoing research projects, which include assessing the antimalarial activities of medicinal plants and their bioactive compounds, immunomodulatory activities mediated by GSK3, and the potential inflammatory pathway involved in malarial infection.