Novel psychoactive substances: An investigation of temporal trends in social media and electronic health records

BACKGROUND

Public health monitoring is commonly undertaken in social media but has never been combined with data analysis from electronic health records. This study aimed to investigate the relationship between the emergence of novel psychoactive substances (NPS) in social media and their appearance in a large mental health database.

METHODS

Insufficient numbers of mentions of other NPS in case records meant that the study focused on mephedrone. Data were extracted on the number of mephedrone (i) references in the clinical record at the South London and Maudsley NHS Trust, London, UK, (ii) mentions in Twitter, (iii) related searches in Google and (iv) visits in Wikipedia. The characteristics of current mephedrone users in the clinical record were also established.

RESULTS

Increased activity related to mephedrone searches in Google and visits in Wikipedia preceded a peak in mephedrone-related references in the clinical record followed by a spike in the other 3 data sources in early 2010, when mephedrone was assigned a 'class B' status. Features of current mephedrone users widely matched those from community studies.

CONCLUSIONS

Combined analysis of information from social media and data from mental health records may assist public health and clinical surveillance for certain substance-related events of interest. There exists potential for early warning systems for health-care practitioners.

Antemortem and postmortem examinations of the cattle calf naturally infected with Mycobacterium avium subsp. paratuberculosis

A male cattle calf was detected as subclinically and naturally infected with Mycobacterium avium subspecies paratuberculosis (MAP) by a series of antemortem and postmortem tests. The MAP infection was identified by strong antibody and cell-mediated immune (CMI) response by a commercial ELISA kit and an intradermal Johnin test, respectively, in the initial antemortem examination. The antemortem status of the calf was further confirmed by MAP-specific interferon gamma (IFN-γ) response. For detection of IFN-γ response, MAP-specific IFN-γ release assays (IGRAs): (a) immuno capture ELISA (IC-ELISA) and (b) ELISPOT was employed. In addition, the presence of intracellular cytokine IFN-γ was detected by flow cytometry. For all cytokine assays, MAP-specific recombinant antigens HSP65 and 35 kDa were employed to overcome the poor sensitivity and specificity resulting from the use of Johnin, the crude protein purified derivative of MAP. Postmortem examination of the MAP-infected/suspected cattle calf did not reveal any pathognomonic gross lesions in the gastro-intestinal tract. Histopathological examination of multiple organs showed the presence of epithelioid cells/macrophages and edematous lesions in the mesenteric lymph nodes suggestive of MAP; however, no granulomas were observed in the intestinal tract. The necropsy samples of rectum and mesenteric lymph nodes were positive for isolation of MAP by culture in the BACTEC™ MGIT™ 960 system, and acid fast bacilli were demonstrated by fluorescence microscopy confirming the infection. Due to differential and complex expression patterns of MAP antigens reported in literature, a combination of assays such as those based on IGRAs and antibody detection is essential. Therefore, the current experimental evidence confirms the efficacy of the approach adopted. However, further studies will be needed to understand the optimal combination MAP-specific antigens for use in IGRAs or antibody assays that can be used for detecting MAP infection in every stage of the disease.

Multi-antigen print immunoassay for seroepidemiological surveillance of bovine tuberculosis on Indian cattle farms

Bovine tuberculosis caused by Mycobacterium bovis is a zoonotic disease that is responsible for significant economic losses in many countries. The standard diagnostic method, the tuberculin test (TST) that is used in control programmes has serious shortcomings and, given the complex nature and the economic impact of the disease, a number of other diagnostic methods have been examined. The authors have attempted to characterise antibody response using the multi-antigen print immunoassay (MAPIA). A total of 511 serum samples were collected from farms in India on which bovine tuberculosis was prevalent and on farms with low incidence. These were tested using the MAPIA against a panel of five defined M. bovis recombinant antigens and two purified protein derivatives (bovine PPD and avian PPD) to study the seroprevalence of the disease on Indian cattle farms. Results indicated that the fusion protein of antigen CFP-10:MPB83 showed a positive response in 142 out of 298 serum samples from tuberculosis-prevalent farms, thereby indicating the serological dominance of the proteins post infection. The antigen selected could be used further in the development of a simple, rapid and accurate serological diagnostic test, paired with TST, for use in bovine tuberculosis control programmes.

Development of recombinant single-chain variable fragment against hepatitis A virus and its use in quantification of hepatitis A antigen

Phage display technology has been utilized for identification of specific binding molecules to an antigenic target thereby enabling the rapid generation and selection of high affinity, fully human antibodies directed towards disease target appropriate for antibody therapy. In the present study, single chain Fv antibody fragment (scFv) to hepatitis A virus (HAV) was selected from phage displayed antibody library constructed from peripheral blood lymphocytes (PBLs) of a vaccinated donor. The variable heavy (V(H)) and light chains (V(L)) were amplified using cDNA as template, assembled into scFv using splicing by overlap extension PCR (SOE PCR) and cloned into phagemid vector as a fusion for display of scFv on bacteriophage. The phage displaying antibody fragments were subjected to three rounds of panning with HAV antigen on solid phase. High affinity antibodies reactive to hepatitis A virus were identified by phage ELISA and cloned into a bacterial expression vector pET20b. The scFv was purified by immobilized metal affinity chromatography (IMAC) on a nickel-nitrilotriacetic acid (NTA) agarose column and characterized. The binding activity and specificity of the scFv was established by its non-reactivity towards other human viral antigens as determined by ELISA and immunoblot analysis. The scFv was further used in the development of an in-house IC-ELISA format in combination with a commercially available mouse monoclonal antibody for the quantification of hepatitis A virus antigen in human vaccine preparations. The adjusted r² values obtained by subjecting the values obtained by quantification of the NIBSC standards using the commercial and the in-house ELISA kits by regression analysis were 0.99 and 0.95. 39 vaccine samples were subjected to quantification using both the kits. Regressional statistical analysis through the origin of the samples indicated International Unit (IU) values of 0.0416x and 0.0419x, respectively for the commercial and in-house kit respectively.

Generation and Characterization of an scFv Directed against Site II of Rabies Glycoprotein

Recombinant antibody phage display technology is a vital tool that facilitates identification of specific binding molecules to a target enabling the rapid generation and selection of high affinity, fully human, or mouse antibody product candidates essentially directed towards disease target appropriate for antibody therapy. In this study, a recombinant single-chain Fv antibody fragment (scFv) A11 was isolated from immune spleen cells obtained from mice immunized with inactivated rabies virus (Pasteur strain) using standard methodology and was characterized for its specificity towards the rabies virus glycoprotein. Epitope mapping using peptide libraries and truncated glycoprotein polypeptides suggested that A11 bound to the antigenic site II of rabies glycoprotein against which a majority of rabies virus neutralizing antibodies are directed. The use of the above technology could, therefore, allow development of scFvs with different specificities against the rabies glycoprotein as an alternative to the more cumbersome protocols used for the development of monoclonal antibodies.

Assessment of critical parameters in blood processing for the bovine interferon-gamma ELISPOT assay to detect Mycobacterium bovis infected cattle in India

In vitro production of bovine interferon gamma (BoIFN-γ) cytokine from bovine peripheral blood mononuclear cells (PBMCs) can be detected using the most sensitive enzyme-linked immunosorbent spot (ELISPOT) assay. ELISPOT assays are dependent on the quantity and quality of PBMC preparations and hence contribute significantly to the performance of this assay. In order to standardise the methods for isolation of PBMCs, we compared two methods for the processing of bovine blood which included aliquots of blood that were stored in a horizontal position without dilution or agitation and aliquots of blood that were immediately diluted 1:1 with complete Rosewell Park Memorial Institute (RPMI) 1640 medium and stored in a horizontal position with gentle agitation. PBMCs were isolated at 2, 4, 6, 8 and 24 h and at 4°C and at 22°C ± 2°C. They were stimulated using tuberculosis-specific antigens, after which the ELISPOT assay was performed. Quantities of spot-forming cells (SFC) created by the release of BoIFN-γ in ELISPOT assays were significantly greater in the samples stored at 22°C ± 2°C than those held +4°C and the intensity of the signals dropped following processing after 6 h. A further drop in SFC was observed in those samples that had been stored undiluted and without agitation. These findings demonstrated that optimisation of PBMC isolation procedures can lead to increased sensitivity in the detection of BoIFN-γ using the ELISPOT assay, thus contributing to an enhanced diagnosis of bovine tuberculosis.

Development of a recombinant epsilon toxoid vaccine against enterotoxemia and its use as a combination vaccine with live attenuated sheep pox virus against enterotoxemia and sheep pox

Sheep pox and enterotoxemia are important diseases of sheep, and these diseases cause severe economic losses to sheep farmers. The present study was undertaken to evaluate the potential of formaldehyde-inactivated recombinant epsilon toxin as a vaccine candidate. The potency of the recombinant epsilon toxoid with aluminum hydroxide as an adjuvant in sheep was determined. Vaccinated sheep were protected against enterotoxemia, with potency values of >5 IU being protective. Further, the use of this construct in a combination vaccine against sheep pox resulted in the sheep being protected against both sheep pox and enterotoxemia.

Immune responses against recombinant tick antigen, Bm95, for the control of Rhipicephalus (Boophilus) microplus ticks in cattle

Immune responses against Bm95 recombinant cattle tick antigen and its protective efficacy for control of Rhipicephalus (Boophilus) microplus ticks were determined in experimental crossbred cow calves. Anti-Bm95 antibody titers, as assessed by indirect ELISA, in immunized calves ranged from 196.1+/-13.7 on day 0 to 7979.9+/-312.5 on day 110 post-primary immunization. The rise in antibody titer was statistically significant (p<0.01) throughout the study period. Besides this, constantly higher lymphoproliferative response (LPR), as assessed by lymphocyte stimulation test, was observed from 10 days post-immunization, but a positive LPR of antigen stimulated cells in immunized animals was recorded only on day 50 and day 70 post-immunization. Following challenge of immunized calves with larvae of R. microplus, significant increase (p<0.01) in rejection percentage, mean number of damaged ticks, mean percentage of dead ticks, and decrease in engorgement weight were recorded in immunized animals. Also, there were significant differences (p<0.01) in preoviposition period, oviposition period, egg mass weight and percent hatchability between the immunized and control calves. The percent reduction in number of adult females in vaccinated calves, reduction in mean weight of egg masses, percent reduction in mean weight and reduction in fertility of engorged females collected from vaccinated calves were determined and the efficacy of Bm95 recombinant cattle tick antigen was 81.27%.

Mathematical modeling and synthetic biology

Synthetic biology is an engineering discipline that builds on our mechanistic understanding of molecular biology to program microbes to carry out new functions. Such predictable manipulation of a cell requires modeling and experimental techniques to work together. The modeling component of synthetic biology allows one to design biological circuits and analyze its expected behavior. The experimental component merges models with real systems by providing quantitative data and sets of available biological 'parts' that can be used to construct circuits. Sufficient progress has been made in the combined use of modeling and experimental methods, which reinforces the idea of being able to use engineered microbes as a technological platform.

Chimeric tymovirus-like particles displaying foot-and-mouth disease virus non-structural protein epitopes and its use for detection of FMDV-NSP antibodies

Expression of Physalis mottle tymovirus (PhMV) coat protein (CP) in Escherichia coli (E. coli) was earlier shown to self-assemble into empty capsids that are nearly identical to the capsids formed in vivo. Aminoacid substitutions were made at the N-terminus of wild-type PhMV CP with single or tandem repeats of infection related B-cell epitopes of foot-and-mouth disease virus (FMDV) non-structural proteins (NSPs) 3B1, 3B2, 3AB, 3D and 3ABD of lengths 48, 66, 49, 51 and 55, respectively to produce chimeras pR-Ph-3B1, pR-Ph-3B2, pR-Ph- 3AB, pR-Ph-3D and pR-Ph-3ABD. Expression of these constructs in E. coli resulted in chimeric proteins which self-assembled into chimeric tymovirus-like particles (TVLPs), Ph-3B1, Ph-3B2, Ph-3AB, Ph-3D and Ph-3ABD as determined by ultracentrifugation and electron microscopy. Ph-3B1, Ph-3B2, Ph-3AB and Ph-3ABD reacted with polyclonal anti-3AB antibodies in ELISA and electroblot immunoassay, while wild-type PhMV TVLP and Ph-3D antigens did not react. An indirect ELISA (I-ELISA) was developed using Ph-3AB to detect FMDV-NSP antibodies in sera of animals that showed clinical signs of FMD. Field serum samples from cattle, buffalos, sheep, goats and pigs were examined by using these chimeric TVLPs for the differentiation of FMDV infected animals from vaccinated animals (DIVA). The assay was demonstrated to be highly specific (100%) and reproducible with sensitivity levels (94%) comparable to the Ceditest kit (P>0.05).

Molecular characterization of foot-and-mouth disease virus type C of Indian origin

Comparison of nucleotide sequences of the partial 1D region of foot-and-mouth disease type C viruses of Indian origin with those of European, South American, and Southeast Asian viruses revealed that the Indian viruses form a distinct genotype. The vaccine strain C IND/51/79 belongs to this genotype and may be a prototype strain of this genotype.