High sensitivity DNA detection using gold nanoparticle functionalised polyaniline nanofibres

Polyaniline (PANI) nanofibres (PANI-NF) have been modified with chemically grown gold nanoparticles to give a nanocomposite material (PANI-NF-AuNP) and deposited on gold electrodes. Single stranded capture DNA was then bound to the gold nanoparticles and the underlying gold electrode and allowed to hybridise with a complementary target strand that is uniquely associated with the pathogen, Staphylococcus aureus (S. aureus), that causes mastitis. Significantly, cyclic voltammetry demonstrates that deposition of the gold nanoparticles increases the area available for DNA immobilisation by a factor of approximately 4. EPR reveals that the addition of the Au nanoparticles efficiently decreases the interactions between adjacent PANI chains and/or motional broadening. Finally, a second horseradish peroxidase (HRP) labelled DNA strand hybridises with the target allowing the concentration of the target DNA to be detected by monitoring the reduction of a hydroquinone mediator in solution. The sensors have a wide dynamic range, excellent ability to discriminate DNA mismatches and a high sensitivity. Semi-log plots of the pathogen DNA concentration vs. faradaic current were linear from 150×10(-12) to 1×10(-6) mol L(-1) and pM concentrations could be detected without the need for molecular, e.g., PCR or NASBA, amplification.     

The canal fill ratio as a factor influencing the aseptic loosening of the Müller-type cemented stem--preliminary report

The Müller type cemented hip prosthesis, also called self-locking prosthesis, is one of the most extensively copied and utilized hip prostheses. Considering the implantation of the cemented stem, the author originally suggested achieving a press fit between the stem and endostal cortex by implanting a prosthesis of the largest possible size. Analyzing our group of patients who undergo aseptic stem revision, we try to quantify the term "press fit" by measuring the filling of the femoral canal by the metal stem, the so-called canal-fill ratio. Our preliminary results suggest that press-fit is achieved when the stem occupies more than 90% of the canal diameter in the anterior-posterior projection.     

Pulmonary embolism caused by a migrated gunshot projectile

Pulmonary embolism caused by a foreign body is an exceedingly rare event. We report on a 62 year old woman who suffered a gun shot injury to her left knee with concomitant vascular lacerations. The bullet migrated through the venous system into the pulmonary circulation causing a pulmonary embolism. The projectile remained stationary for ten years. Taking into consideration that she is virtually asymptomatic and that regular follow up examinations showed no further migration of the foreign body, we opted for a conservative venue of management.     

Croatian national reference Y-STR haplotype database

A reference Y-chromosome short tandem repeat (STR) haplotype database is needed for Y-STR match interpretation as well as for national and regional characterization of populations. The aim of this study was to create a comprehensive Y-STR haplotype database of the Croatian contemporary population and to analyze substructure between the five Croatian regions. We carried out a statistical analysis of the data from previously performed genetic analyses collected during routine forensic work by the Forensic Science Centre "Ivan Vu?eti?". A total of 1,100 unrelated men from eastern, western, northern, southern and central Croatia were selected for the purpose of this study. Y-STRs were typed using the AmpFISTR Yfiler PCR amplification kit. Analysis of molecular variance calculated with the Y chromosome haplotype reference database online analysis tool included 16 population samples with 20,247 haplotypes. A total of 947 haplotypes were recorded, 848 of which were unique (89.5%). Haplotype diversity was 0.998, with the most frequent haplotype found in 9 of 1,100 men (0.82%). Locus diversity varied from 0.266 for DYS392 to 0.868 for DYS385. Discrimination capacity was 86.1%. Our results suggested high level of similarity among regional subpopulations within Croatia, except for mildly different southern Croatia. Relative resemblance was found with Bosnia and Herzegovina and Serbia. Whit Atheys' Haplogroup Predictor was used to estimate the frequencies of Y-chromosome haplogroups. I2a, R1a, E1b1b and R1b haplogroups were most frequent in all Croatian regions. These results are important in forensics and contribute to the population genetics and genetic background of the contemporary Croatian population.     

Comparison of glycosylation patterns of placental proteins between normal pregnancy and missed abortion

Contemporary understanding of missed abortion, as the case of spontaneous abortion where embryo is retained in uterus for four-weeks or more after its death, is very poor. Aiming to improve the level of knowledge about this process, we have compared glycosylation patterns of placental proteins in normal pregnancy and missed abortion. Oligosaccharide branches were detected by Western-blot using SNA, DBA and PHA-E lectins. The comparison of samples of the same gestational age enabled identification of changes in protein glycosylation between normal and pathological placentas. Lectin DBA detects in normal placenta the glycoprotein GP 105 during the eleventh week, which is absent in missed abortion. PHA-E identifies GP 71 during fourteenth week only in normal placenta. However GP 25 recognized by SNA in missed abortion was not found in normal pregnancy at tenth week. These results indicate that abnormal placental development is associated with changes in glycoprotein structures, and that glycoconjugates might have an important role in placental development.     

Lymphocyte subpopulations and the expression of intercellular adhesion molecules in chronic periodontitis

Immunological responses to invading bacteria play a major role in the course of inflammatory periodontal diseases, such as CP. It was suggested that one of the major elements in determining the course of the disease is the expression of cellular adhesion molecules. We therefore investigated the expression of cellular adhesion molecules, ICAM-1 and beta-1 integrins, capillary density and lymphocyte subpopulations in gingival biopsies obtained from 20 patients with CP who responded and 21 patient who failed to respond to initial treatment using immunohistochemical methods. We found no differences between the two groups in capillary density, ICAM-1 and beta-1 integrin expression. Patients who responded to treatment had a lymphocytic inflammatory infiltrate consisting predominantly of T cells, while those who failed to respond had an approximately equal number of T and B cells. Our findings support the role of host immunological mechanisms in determining the outcome of CP and argue against a major role of differential cellular adhesion molecule expression.