Inductively coupled plasma mass spectrometry determination of metals in honeybee venom

Inductively coupled plasma mass spectrometry (ICP-MS) technique was used to analyze the contamination of selected 20 metals in 32 samples of honeybee venom and to demonstrate differences in the content of these elements. Among the analyzed metal microelements (Al, Co, Cu, Zn, Mn, Mo, B, V, Sr and Ni), macro-elements (Ca, Mg, K and Na) and toxic metals (As, Ba, Pb, Cd, Sb and Cr) were identified. The presented results showed that the metal levels in honeybee venom are much lower than the tolerable upper intake levels for the elements. Also the toxic metal contamination is much lower than the permissible levels for drugs established by the United States Pharmacopeia and the European Pharmacopeia. As opposed to the pharmacopeial tests for metals, a multi-element ICP-MS method has been developed. In order to confirm data obtained, the following steps and parameters were taken into account for the validation of the method: calibration verification, recovery, accuracy, precision, detection limit (LOD), quantitation limit (LOQ), spectral and matrix interference and comparison between ICP-MS and GFAAS (graphite furnace atomic absorption spectrometry) for Mn. All steps of validation proved the accuracy of the results. This is most likely the first study in which the metal content in honeybee venom was evaluated by ICP-MS.     

Genetic characterization of H9N2 avian influenza viruses isolated from poultry in Poland during 2013/2014

The study presents molecular characterization of H9N2 avian influenza (AI) isolates from field outbreaks in turkeys that occurred in Poland in 2013–2014. Sequences of all gene segments of one isolate from 2013 (A/turkey/Poland/14/2013(H9N2)) and two isolates from 2014 (A/turkey/Poland/08/2014(H9N2), A/turkey/Poland/09/2014(H9N2)) were obtained and analyzed in search of the phylogenetic relationship and molecular markers of zoonotic potential or increased pathogenicity. All gene segments were shown to originate from the wild bird reservoir and the close relationship of the analyzed isolates proved the link between the outbreaks in 2013 and 2014. However, remarkable molecular differences between isolates from 2013 to 2014 were identified, including mutation in the HA cleavage site (CS) leading to conversion from the PAASNR*GLF to the PAASKR*GLF motif and truncation of the PB1-F2 protein. Additionally, T97I substitution in the PA protein in A/turkey/Poland/08/2014 was detected which can be responsible for enhanced activity of viral polymerase in mammalian cells. However, experimental infection of mice with both isolates from 2014 showed their low pathogenicity, and no statistically significant differences in virus replication were observed between the viruses. Nevertheless, these findings indicate the dynamic evolution of H9N2 in the field emphasizing the need for monitoring of the situation in terms of H9N2 AI in Europe.     

Can optical coherence tomography replace fluorescein angiography in detection of ischemic diabetic maculopathy?

Background

We studied the association between (1) the retinal thickness, volume and structure assessed by optical coherence tomography (OCT), and (2) vascular changes around the fovea in FA to define the role of these methods in the detection of ischemic diabetic maculopathy.

Methods

This retrospective observational study included 51 eyes of 51 patients with severe non-proliferative and proliferative diabetic retinopathy, considering that they present advanced ischemic retinal changes. Based on the clinical examination and presence of leakage on FA, patients with clinically significant macular edema were excluded. On FA, foveal avascular zone (FAZ) corresponds to capillary loss and reflects ischemic processes. Its outline and size were assessed according to the ETDRS standards. Patients were divided in two groups according to the severity of damage of the FAZ outline: ≤ grade 2 (n?=?28) and ≥ grade 3 (n?=?23). As we expected ischemia-related damage, SD-OCT images were evaluated for retinal structure, volume, total thickness with division into the outer and inner retina (to assess the influence of two, non-overlapping blood sources) and ganglion cell layer thickness.

Results

The comparisons revealed that at least currently with described methods: 1. There is no significant association between FAZ outline and retinal volume, total thickness, and thickness of the outer and inner retina and ganglion cell layer. 2. There is no significant association between FAZ outline and following retinal structure characteristics: continuity of the external limiting membrane and inner segment/outer segment junction, and identification of the inner/outer retina boundary. 3. The identification of ganglion cell layer boundaries was significantly more difficult in more advanced FAZ outline grades. 4. FAZ size is not correlated with the retinal thickness and volume.

Conclusions

In patients with severe non-proliferative and proliferative diabetic retinopathy, it is not possible to predict FAZ outline/size based solely on the measurements assessing volume and thickness or retinal structure evaluation on OCT. Consequently, at present OCT cannot replace FA in the detection of ischemic diabetic maculopathy.     

Quantitative analysis of norfloxacin by 1H NMR and HPLC

1H NMR and developed previously HPLC methods were applied to quantitative determination of norfloxacin in veterinary solution form for pigeon. Changes in concentration can lead to significant changes in the 1H chemical shifts of non-exchangeable aromatic protons as a result of extensive self-association phenomena. This chemical shift variation of protons was analyzed and applied in the quantitative determination of norfloxacin. The method is simple, rapid, precise and accurate, and can be used for quality control of this drug.     

Genetic characterization of parvoviruses circulating in turkey and chicken flocks in Poland

Between 2008 and 2011, commercial turkey and chicken flocks in Poland were examined for the presence of turkey parvovirus (TuPV) and chicken parvovirus (ChPV). Clinical samples (10 individual faecal swabs/flock) from 197 turkey flocks (turkeys aged 1 to 19 weeks) and 45 chicken flocks (chickens aged 3 to 17 weeks) were collected in different regions of the country and tested using a PCR assay that targeted the NS1 gene (3’ORF). The prevalence of TuPV was 29.4 % in the flocks tested, while ChPV infections were found in 22.2 % of the studied flocks. Phylogenetic analysis revealed a clear division into three groups: ChPV-like, TuPV-like and a third, previously unrecognized and distinct subgroup, TuPV-LUB, containing exclusively three Polish isolates from turkeys. The isolates from the novel group showed as little as 50.6-64.5 % of nucleotide sequence identity to the prototype chicken and turkey parvovirus strains. Genetic analysis of a ChPV isolate that was classified in the TuPV group strongly suggests a recombination event between chicken and turkey parvoviruses.