Pharmacovigilance using clinical notes

With increasing adoption of electronic health records (EHRs), there is an opportunity to use the free-text portion of EHRs for pharmacovigilance. We present novel methods that annotate the unstructured clinical notes and transform them into a deidentified patient-feature matrix encoded using medical terminologies. We demonstrate the use of the resulting high-throughput data for detecting drug-adverse event associations and adverse events associated with drug-drug interactions. We show that these methods flag adverse events early (in most cases before an official alert), allow filtering of spurious signals by adjusting for potential confounding, and compile prevalence information. We argue that analyzing large volumes of free-text clinical notes enables drug safety surveillance using a yet untapped data source. Such data mining can be used for hypothesis generation and for rapid analysis of suspected adverse event risk.

Influence of oxygenated fuel additives and their metabolites on gamma-aminobutyric acidA (GABAA) receptor function in rat brain synaptoneurosomes

Experimental and occupational inhalational exposure to oxygenate fuel additives in reformulated gasoline has been reported to induce neurological symptoms (e.g., headache, nausea, dizziness). We reported previously that the ether additives (methyl-t-butyl ether (MTBE), t-amyl-methyl ether (TAME) and ethyl-t-butyl ether (ETBE)) and their metabolites (t-amyl alcohol (TAA), t-butyl alcohol (TBA) and ethanol) alter the binding of [3H]t-butylbicycloorthobenzoate ([3H]TBOB), a ligand for the gamma-aminobutyric acidA (GABAA) receptor in rat brain membrane preparations. To more directly assess the effects of the ethers and their alcohol precursors on GABAA receptor function, the uptake of 36Cl- was measured in synaptoneurosomes, a preparation of closed membrane sacs comprised of pre- and postsynaptic membranes from adult rat cerebral cortex. Each of the compounds caused a concentration-dependent enhancement of muscimol-stimulated uptake of 36CI-, which diminished with further increasing concentrations. The potency of the enhancement by the compounds was in the rank order: MTBE = TAME > TAA = ETBE > TBA > ethanol. The half-maximally effective concentration (EC50) for the facilitation of muscimol-stimulated 36Cl- uptake ranged from 0.06 to 3 mM, and that for the higher-dose inhibitory effect (IC50) ranged from 3 to 50 mM. The facilitatory concentrations of the compounds are in the range of the blood concentrations reported in experimental animals after exposures known to induce CNS effects such as ataxia. The results suggest a potential role of the GABAA receptor in some of the reported neurotoxic effects of gasoline additives.

Chicken vitellogenin gene-binding protein, a leucine zipper transcription factor that binds to an important control element in the chicken vitellogenin II promoter, is related to rat DBP

We screened a chicken liver cDNA expression library with a probe spanning the distal region of the chicken vitellogenin II (VTGII) gene promoter and isolated clones for a transcription factor that we have named VBP (for vitellogenin gene-binding protein). VBP binds to one of the most important positive elements in the VTGII promoter and appears to play a pivotal role in the estrogen-dependent regulation of this gene. The protein sequence of VBP was deduced from a nearly full length cDNA copy and was found to contain a basic/zipper (bZIP) motif. As expected for a bZIP factor, VBP binds to its target DNA site as a dimer. Moreover, VBP is a stable dimer free in solution. A data base search revealed that VBP is related to rat DBP. However, despite the fact that the basic/hinge regions of VBP and DBP differ at only three amino acid positions, the DBP binding site in the rat albumin promoter is a relatively poor binding site for VBP. Thus, the optimal binding sites for VBP and DBP may be distinct. Similarities between the VBP and DBP leucine zippers are largely confined to only four of the seven helical spokes. Nevertheless, these leucine zippers are functionally compatible and appear to define a novel subfamily. In contrast to the bZIP regions, other portions of VBP and DBP are markedly different, as are the expression profiles for these two genes. In particular, expression of the VBP gene commences early in liver ontogeny and is not subject to circadian control.

Antibodies to N-acetylglucosamine and heparin in acute and remission phases of rheumatic fever

The etiology of acute rheumatic fever (ARF) is believed to involve an immunological response to group A streptococcal antigens. Antibodies to group A carbohydrate (A-CHO) have been reported in ARF and rheumatic heart disease patients. As N-acetylglucosamine (GlcNAc) units form the major immunodominant regions in A-CHO antigens, we investigated levels of antibodies to GlcNAc and heparin (with repeated sequences of GlcNAC) in rheumatic fever (RF) patients. Serum samples from 26 acute cases (ARF), 18 remission cases and 17 normal healthy subjects were analyzed for IgG and IgM levels of antibodies to GlcNAc and heparin. High titres of IgG antibodies to heparin and GlcNAc were observed in the ARF group in comparison with controls (p less than 0.0025 and 0.0125 respectively). There was no difference in the levels of IgM antibodies. Remission group demonstrated low titres of IgG to heparin and GlcNAc (p less than 0.01 and 0.0125 respectively) in comparison with ARF group. Heparin antibodies of IgM class was comparatively lower in remission group (p less than 0.005). While the role of these antibodies in different phases of RF needs to be investigated, we conclude that GlcNAc antibodies do not play any role in the pathogenesis of RF or rheumatic heart disease.

Microbiological evaluation of female patients in STD clinics

A total of 215 women patients attending the STD clinic were evaluated in an attempt to isolate the different microorganisms in sexually transmitted diseases (STD). Mycoplasmas (30.22%), Candida species (20.00%), Trichomonas vaginalis (wet mount study; 15.81%), beta haemolytic streptococci (13.48%), Neisseria gonorrhoeae (9.30%), Staphylococcus aureus (13.95%), inclusion bodies of Chlamydia trachomatis (11.60%) and Gram negative organisms (9.30%) were isolated from these patients. Sera of all patients screened for HBsAg by ELISA showed a carrier rate of 12.5 per cent; 29.8 per cent sera were reactive in the VDRL test at the dilutions varying from 1:4 to 1:64.

Production of H-Y antibody in the ascites fluid of mouse and localization of the antigen on cells and tissues

A procedure is described for the production of large amounts of ascites fluid containing specific H-Y antibody. The distribution of H-Y antigen on mouse epididymal spermatozoa, thymocytes, and splenocytes was carried out using this specific antibody in the microcytotoxicity test and ELISA. Employing the indirect immunofluorescent technique, the H-Y antigen was localized on the acrosomal membrane of mouse epididymal and washed ejaculated human spermatozoa and on the entire membrane of mouse splenocytes and thymocytes. Immunohistochemical localization of the antigen in the testicular section indicated its presence in the cytoplasm of Leydig cells and on the membrane of Sertoli cells and sperm heads.