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BackgroundSevere leptospirosis is challenging as it could evolve rapidly and potentially fatal if appropriate management is not performed. An understanding of the progression and pathophysiology of Leptospira infection is important to determine the early changes that could be potentially used to predict the severe occurrence of leptospirosis. This study aimed to understand the kinetics pathogenesis of Leptospira interrogans strain HP358 in the hamster model and identify the early parameters that could be used as biomarkers to predict severe leptospirosis.Methodology/principal findingsMale Syrian hamsters were infected with Leptospira interrogans strain HP358 and euthanized after 24 hours, 3, 4, 5, 6 and 7 days post-infection. Blood, lungs, liver and kidneys were collected for leptospiral detection, haematology, serum biochemistry and differential expression of pro- and anti-inflammatory markers. Macroscopic and microscopic organ damages were investigated. Leptospira interrogans strain HP358 was highly pathogenic and killed hamsters within 6-7 days post-infection. Pulmonary haemorrhage and blood vessel congestion in organs were noticed as the earliest pathological changes. The damages in organs and changes in biochemistry value were preceded by changes in haematology and immune gene expression.Conclusion/significanceThis study deciphered haemorrhage as the earliest manifestation of severe leptospirosis and high levels of IL-1β, CXCL10/IP-10, CCL3/MIP-α, neutrophils and low levels of lymphocytes and platelets serve as a cumulative panel of biomarkers in severe leptospirosis.

Mammalian long bone growth occurs through endochondral ossification, majorly regulated by the controlled enlargement of chondrocytes at the growth plate (GP). This study aimed to investigate the roles of Na+/H+ (sodium hydrogen exchanger (NHE1)) and HCO3− (anion exchanger [AE2]) during longitudinal bone growth in mammals. Bones from P10 SpragueDawley rat pups were cultured exvivo in the presence or absence of NHE1 and AE2 inhibitors to determine their effect on long bone growth. Gross morphometry, histomorphometry, and immunohistochemistry were used to assess the bone growth. The results revealed that the culture of the bones in the presence of NHE1 and AE2 inhibitors reduces bone growth significantly (p < 0.05) by approximately 11%. The inhibitor significantly (p < 0.05) reduces bone growth velocity and the length of the hypertrophic chondrocyte zone without any effect on the total GP length. The total GP chondrocyte density was significantly (p < 0.05) reduced, but hypertrophic chondrocyte densities remained constant. NHE1 fluorescence signaling across the GP length was higher than AE2, and their localization was significantly (p < 0.05) inhibited at the hypertrophic chondrocytes zone. The GP lengthening was majorly driven by an increase in the overall GP chondrocyte and hypertrophic chondrocyte densities apart from the regulatory volume phenomenon. This may suggest that NHE1 and AE2 could have a regulatory role in long bone growth.

This paper reports the prebiotic efficacy of soluble crude polysaccharides (SCP) from palm kernel cake on the growth rates and acidifying property of probiotic lactic acid bacteria (LAB), Lactobacillus plantarum ATCC 8014 and Lactobacillus rhamnosus ATCC 53103, to investigate into the potential SCP of an agriculture by-product as a novel prebiotic. The highest extraction yield of SCP (2.90%) was obtained using NaOH. The extracted polysaccharides were highly soluble (>97%). The highest percentage of protein (0.63 ± 0.09%) and the total carbohydrate content (55.36 ± 0.33%) were observed in NaOH-extracted SCP (SCPN) and citric acid-extracted SCP (SCPCA). Water-extracted SCP (SCPW) contained the highest percentage of glucose, whereas SCPCA demonstrated the presence of two major monosaccharides, galactose and mannose. Structural analysis of SCP showed peaks in the range of 1000–1077 cm−1, an indication of the presence of polysaccharides and alpha (α)- or beta (β)-glycosidic linkages. The degree of hydrolysis increased with the increase of pH from 5 to 8 following 4 h incubation. SCPW and SCPCA were more resistant (95%) to α-amylase as compared to fructooligosaccharides (FOS). As in the case of FOS (∼98%), SCPW (∼99%) and SCPCA (∼98%) were resistant to artificial human gastric juice and their degree of hydrolysis had negative correlation with the pH. The product was found to markedly stimulate the proliferation of the tested probiotics and acid production. All the above findings are supportive of the fact that polysaccharides extracted from CKC have a vast potential to be exploited as novel prebiotic.

Abstract Background Selection of a microbial strain for the incorporation into food products requires in vitro and in vivo evaluations. A bacteriocin-producing lactic acid bacterium (LAB), Pediococcus acidilactici Kp10, isolated from a traditional dried curd was assessed in vitro for its beneficial properties as a potential probiotic and starter culture. The inhibitory spectra of the bacterial strain against different gram-positive and gram-negative bacteria, its cell surface hydrophobicity and resistance to phenol, its haemolytic, amylolytic and proteolytic activities, ability to produce acid and coagulate milk together with its enzymatic characteristics and adhesion property were all evaluated in vitro. Results P. acidilactici Kp10 was moderately tolerant to phenol and adhere to mammalian epithelial cells (Vero cells and ileal mucosal epithelium). The bacterium also exhibited antimicrobial activity against several gram-positive and gram-negative food-spoilage and food-borne pathogens such as Listeria monocytgenes ATCC 15313, Salmonella enterica ATCC 13311, Shigella sonnei ATCC 9290, Klebsiella oxytoca ATCC 13182, Enterobacter cloaca ATCC 35030 and Streptococcus pyogenes ATCC 12378. The absence of haemolytic activity and proteinase (trypsin) and the presence of a strong peptidase (leucine-arylamidase) and esterase-lipase (C4 and C8) were observed in this LAB strain. P. acidilactici Kp10 also produced acid, coagulated milk and has demonstrated proteolytic and amylolactic activities. Conclusion The properties exhibited by P. acidilactici Kp10 suggested its potential application as probiotic and starter culture in the food industry.

Background: Osteosarcoma (OS) is a highly malignant primary bone cancer. Severe side effects and multidrug resistance are obstacles faced with chemotherapy against OS. With the hope to overcome the obstacles of the conventional chemotherapy, various targeted drug delivery systems using nanotechnology have been explored in the past few decades. Biogenic calcium carbonate (CaCO3) has great potential to be a smart drug delivery system. Results: In this study, cockle shells-derived aragonite nanoparticles (ANPs) were developed and loaded with doxorubicin (DOX). The physicochemical properties of the DOX-loaded ANPs (DOX-ANPs) were characterised by various techniques. The results of drug-loading study demonstrated that DOX was loaded onto ANPs at high loading and encapsulation efficiency (11.09% and 99.58%, respectively). The pH-sensitive release of DOX from DOX-ANPs was successful. At lower pH values (4.8), the release of DOX was much quicker than that at pH 7.4. Additionally, cellular uptake study using fluorescence microscopy showed obviously cellular uptake of DOX-ANPs through endocytosis. Moreover, the flow cytometric analysis revealed DOX-ANPs-induced cell cycle arrest, which was consistent with the mechanism of DOX. DOX-ANPs also showed an efficient cytotoxicity against OS cancer cells, close to the toxicity effect of free DOX at the same concentration. Morphological observations showed microvilli disappearance, chromatin condensation, cell shrinkage, membrane blebbing, and formation of apoptotic bodies, which confirmed both DOX-ANPs- and DOX-induced apoptosis of OS cancer cells in vitro. Conclusion: Our findings indicated that ANPs could act as a pH-sensitive drug delivery against OS.

Drug delivery systems are designed to achieve drug therapeutic index and enhance the efficacy of controlled drug release targeting with specificity and selectivity by successful delivery of therapeutic agents at the desired sites without affecting the non-diseased neighbouring cells or tissues. In this research, we developed and demonstrated a bio-based calcium carbonate nanocrystals carrier that can be loaded with anticancer drug and selectively deliver it to cancer cells with high specificity by achieving the effective osteosarcoma cancer cell death without inducing specific toxicity. The results showed pH sensitivity of the controlled release characteristics of the drug at normal physiological pH 7.4 with approximately 80% released within 1,200 min but when exposed pH 4.8 the corresponding 80% was released in 50 min. This study showed that the DOX-loaded CaCO3 nanocrystals have promising applications in delivery of anticancer drugs.

The present study investigates the detection of lard in cocoa butter through changes in fatty acids composition, triacylglycerols profile, and thermal characteristics. Cocoa butter was mixed with 1% to 30% (v/v) of lard and analyzed using a gas chromatography flame ionization detector, high performance liquid chromatography, and differential scanning calorimetry. The results revealed that the mixing of lard in cocoa butter showed an increased amount of oleic acid in the cocoa butter while there was a decrease in the amount of palmitic acid and stearic acids. The amount of POS, SOS, and POP also decreased with the addition of lard. A heating thermogram from the DSC analysis showed that as the concentration of lard increased from 3% to 30%, two minor peaks at −26 °C and 34.5 °C started to appear and a minor peak at 34.5 °C gradually overlapped with the neighbouring major peak. A cooling thermogram of the above adulterated cocoa butter showed a minor peak shift to a lower temperature of −36 °C to −41.5 °C. Values from this study could be used as a basis for the identification of lard from other fats in the food authentication process.

Abstract Background Feline infectious peritonitis virus (FIPV) and feline enteric coronavirus (FECV) are two important coronaviruses of domestic cat worldwide. Although FCoV is prevalent among cats; the fastidious nature of type I FCoV to grow on cell culture has limited further studies on tissue tropism and pathogenesis of FCoV. While several studies reported serological evidence for FCoV in Malaysia, neither the circulating FCoV isolated nor its biotypes determined. This study for the first time, describes the isolation and biotypes determination of type I and type II FCoV from naturally infected cats in Malaysia. Findings Of the total number of cats sampled, 95% (40/42) were RT-PCR positive for FCoV. Inoculation of clinical samples into Crandell feline kidney cells (CrFK), and Feline catus whole fetus-4 cells (Fcwf-4), show cytopathic effect (CPE) characterized by syncytial cells formation and later cell detachment. Differentiation of FCoV biotypes using RT-PCR assay revealed that, 97.5% and 2.5% of local isolates were type I and type II FCoV, respectively. These isolates had high sequence homology and phylogenetic similarity with several FCoV isolates from Europe, South East Asia and USA. Conclusions This study reported the successful isolation of local type I and type II FCoV evident with formation of cytopathic effects in two types of cell cultures namely the CrFK and Fcwf-4 , where the later cells being more permissive. However, the RT-PCR assay is more sensitive in detecting the antigen in suspected samples as compared to virus isolation in cell culture. The present study indicated that type I FCoV is more prevalent among cats in Malaysia.

Drug delivery systems are designed to achieve drug therapeutic index and enhance the efficacy of controlled drug release targeting with specificity and selectivity by successful delivery of therapeutic agents at the desired sites without affecting the non-diseased neighbouring cells or tissues. In this research, we developed and demonstrated a bio-based calcium carbonate nanocrystals carrier that can be loaded with anticancer drug and selectively deliver it to cancer cells with high specificity by achieving the effective osteosarcoma cancer cell death without inducing specific toxicity. The results showed pH sensitivity of the controlled release characteristics of the drug at normal physiological pH 7.4 with approximately 80% released within 1,200 min but when exposed pH 4.8 the corresponding 80% was released in 50 min. This study showed that the DOX-loaded CaCO3 nanocrystals have promising applications in delivery of anticancer drugs. [ABSTRACT FROM AUTHOR]

A fracture model in rats for the study of secondary bone healing was described. Standard open midshaft transverse metatarsal fracture was produced with bone cutting forceps in 28 rats. The commonly open and close fracture models utilized for bone and mineral researches are associated with varying degree of complications ranging from a high degree of fracture comminution to severe associated soft tissue injury which interferes with the healing process. We hypothesized that fracture model in rat third metatarsal bone could be associated with low -post-surgical complications and could be a reproducible model. To test this, open mid-shaft transverse fractures were created on the metatarsals of 28 rats. The objectives of the study were to evaluate the fracture complications, to determine the nature of fracture produced, evaluate the fracture consolidation during healing periods, and to assess the histological and radiographic healing of the fracture. The fracture produced in the mid metatarsal shaft of all rats was 100% transverse, 73% located at the midshaft. Minimal fracture angulations were recorded (0.48 ± 0.09o; 0.78 ± 0.17o) for anterior-posterior and lateral views respectively. Minimal soft tissue injury was recorded immediately post-surgery, but no infection and the delayed union was observed. Varying degrees of weight-bearing lameness was also recorded but seized at day six onward post-operative. Callus index observed was peaked at week 2 and 3 (2.02 ± 0.1, 1.99 ± 0.13) respectively but declined to 1.10 ± 0.04 at week 7 during the consolidation period. The fracture line disappeared completely at week 7. The histological and radiographic healing scores were (3.5 ± 0.13 and 3.75 ± 0.25) respectively (out of the maximum healing score of 4) at week 7 post-operative. There was a positive correlation between the histological and radiographic healing scores. The metatarsal fracture model is considered to be a suitable model for in vivo study of secondary fracture healing. Doi: 10.28991/SciMedJ-2020-0204-2 Full Text: PDF