Diamond-like carbon (DLC) microelectrode for electrochemical ELISA

A diamond-like carbon (DLC) microelectrode was applied to commercial ELISA kits for medical diagnosis of HIV (human immunodeficiency virus), HBV (human hepatitis B virus), HCV (human hepatitis C virus). In this work, quantification of oxidized 3,3',5,5'-tetramethylbenzidine (TMB) was carried out by using a microelectrode made of boron-doped DLC and cyclic voltammetric analysis method without the conventional quenching step which uses sulfuric acid. The microelectrode provided well-known step-shaped graphs, and limit of detection could be improved by clear determination of electrochemical oxidative and reductive peaks. To demonstrate the applicability of DLC microelectrode to conventional ELISA kits, commercial ELISA kits for detection of HIV antigen, HBV antigen and HCV antigen were also tested. These results proved that the applicability of DLC microelectrode to practical detection is feasible.     

Fungal Olecranon Bursitis in an Immunocompetent Patient by <Emphasis Type="Italic">Knoxdaviesia dimorphospora</Emphasis> sp. nov.: Case Report and Review

Bursitis is a common medical condition that can occur either with or without infection. We present a case of fungal olecranon bursitis in an immunocompetent individual caused by the new species Knoxdaviesia dimorphospora. It is a dematiaceous filamentous fungus characterized by the production of two different conidia: hyaline and cylindrical, which rise up from phialidic conidiogenous cells located in the upper part of differentiated and unbranched conidiophores, and pale brown and ellipsoidal conidia produced by phialidic conidiogenous cells which are born directly on hyphae. In addition to its morphological peculiarities, the novelty of the fungus was confirmed by sequence analysis of the internal transcribed spacer (ITS) regions and D1/D2 domains of the 28S of the nuclear rRNA gene. The fungal infection was confirmed by cytological examination and repeated cultures. The infection was resolved by surgical debridement and drainage, and the patient presented a complete functional recovery 3 months later. The in vitro antifungal susceptibility to this new human opportunist is provided, terbinafine being the drug with the most potent activity.     

Unraveling the mechanisms of tryptophan fluorescence quenching in the triosephosphate isomerase from Giardia lamblia

In the native state several proteins exhibit a quenching of fluorescence of their tryptophans. We studied triosephosphate isomerase from Giardia lamblia (GlTIM) to dissect the mechanisms that account for the quenching of fluorescence of its Trp. GlTIM contains four Trp per monomer (Trp75, Trp162, Trp173, and Trp196) distributed throughout the 3D structure. The fluorescence of the denatured enzyme is 3-fold higher than that of native GlTIM. To ascertain the origin of this phenomenon, single and triple mutants of Trp per Phe were made. The intrinsic fluorescence was determined, and the data were interpreted on the basis of the crystal structure of the enzyme. Our data show that the fluorescence of all Trp residues is quenched through two different mechanisms. In one, fluorescence is quenched by aromatic-aromatic interactions due to the proximity and orientation of the indole groups of Trp196 and Trp162. The magnitude of the quenching of fluorescence in Trp162 is higher than in the other three Trp. Fluorescence quenching is also due to energy transfer to the charged residues that surround Trp 75, 173 and 196. Further analysis of the fluorescence of GlTIM showed that, among TIMs from other parasites, Trp at position 12 exhibits rather unique properties.     

Mid-trimester abortion with 15 (S) methyl prostaglandin F 2 alpha

The efficacy of intramuscular administration of 15 methyl (15S) prostaglandin F2alpha (PGF2a) in midtrimester pregnancy termination was evaluated in 16 healthy patients (mean age, 23.3; mean parity, 1.4; mean number of menstrual weeks, 16.1) by measuring dose response; oxytocin conversion; abortion time; side effects; intrauterine dynamics and progesterone withdrawal. Labor was monitored using extraovular balloon placed transvaginally; transcervically; and connected to a Physiograph machine. Patients not aborting within 48 hours after the first dose were considered failures. Blood samples were collected at 0, 3, and 6 hours and at abortion time for plasma progesterone measurement. Average dose given was 789 +or- 60 micrograms. Only 9 of 10 patients aborted within the prescribed 48 hours: 7 were complete abortions, and 2 were incomplete and required suction curettage. Mean induction to abortion time was 20.2 +or- 2.7 hours. Nausea, vomiting and diarrhea were the main side effects. The findings suggest that 15 methyl PGF2a in the dosages and routes prescribed is not as efficient as PGF2a. It is also suggested that prostaglandin affects the myometrium at 2 levels: 1) a membrane effect, and 2) a more fundamental intracellular regulatory effect which is necessary to initiate labor.     

A Combination of CD28 (rs1980422) and IRF5 (rs10488631) Polymorphisms Is Associated with Seropositivity in Rheumatoid Arthritis: A Case Control Study

IntroductionThe aim of the study was to analyse genetic architecture of RA by utilizing multiparametric statistical methods such as linear discriminant analysis (LDA) and redundancy analysis (RDA).MethodsA total of 1393 volunteers, 499 patients with RA and 894 healthy controls were included in the study. The presence of shared epitope (SE) in HLA-DRB1 and 11 SNPs (PTPN22 C/T (rs2476601), STAT4 G/T (rs7574865), CTLA4 A/G (rs3087243), TRAF1/C5 A/G (rs3761847), IRF5 T/C (rs10488631), TNFAIP3 C/T (rs5029937), AFF3 A/T (rs11676922), PADI4 C/T (rs2240340), CD28 T/C (rs1980422), CSK G/A (rs34933034) and FCGR3A A/C (rs396991), rheumatoid factor (RF), anti–citrullinated protein antibodies (ACPA) and clinical status was analysed using the LDA and RDA.ResultsHLA-DRB1, PTPN22, STAT4, IRF5 and PADI4 significantly discriminated between RA patients and healthy controls in LDA. The correlation between RA diagnosis and the explanatory variables in the model was 0.328 (Trace = 0.107; F = 13.715; P = 0.0002). The risk variants of IRF5 and CD28 genes were found to be common determinants for seropositivity in RDA, while positivity of RF alone was associated with the CTLA4 risk variant in heterozygous form. The correlation between serologic status and genetic determinants on the 1st ordinal axis was 0.468, and 0.145 on the 2nd one (Trace = 0.179; F = 6.135; P = 0.001). The risk alleles in AFF3 gene together with the presence of ACPA were associated with higher clinical severity of RA.ConclusionsThe association among multiple risk variants related to T cell receptor signalling with seropositivity may play an important role in distinct clinical phenotypes of RA. Our study demonstrates that multiparametric analyses represent a powerful tool for investigation of mutual relationships of potential risk factors in complex diseases such as RA.     

Selenium levels in related biological samples: human placenta, maternal and umbilical cord blood, hair and nails.

A study on selenium levels has been carried out in human placenta, maternal and umbilical cord blood, hair and nails of a group of 50 mothers and in the hair of the newborns. The determinations were perfomed by electrothermal atomic absorption spectrometry. The selenium concentration obtained for each sample type was as follows: For the human placenta the values obtained were between 0.56 and 1.06 microg/g (mean +/- standard deviation: 0.81 +/- 0.02 microg/g). The levels for the umbilical cord blood were 51.1-104.2 microg/l (76.3 +/- 6.5 microg/l). For the maternal blood the values measured were between 57.3 and 117.9 microg/l (90.0 +/- 15.2 microg/l), and for hair and nails were 0.22-1.5 microg/g (0.60 +/- 0.37 microg/g) and 0.46-1.57 microg/g (0.90 +/- 0.27 microg/g), respectively. For the hair of the newborns the values obtained were between 0.40 and 2.53 microg/g (1.04 +/- 0.48 microg/g). The effect of different variables as age, habitat, nutritional index or gestation age of the mothers on the selenium concentration in the samples was studied. The influence of the habitat is significant with a confidence level of 95% for the selenium concentration in maternal blood and umbilical cord blood samples. The influence of the mothers' age is significant with a confidence level of 95% for the selenium concentration in the umbilical cord blood samples. For the placenta samples, the effect of the nutritional index is significant with a confidence level of 95%. There is a positive correlation between samples of umbilical cord blood and the newborns' hair, between placenta and umbilical cord, and between cord blood and maternal blood.