The ROS-generating photosensitizer-free NaYF4:Yb,Tm@SiO2upconverting nanoparticles for photodynamic therapy application.

In this work we adapt rare-earth-ion-doped NaYF4nanoparticles coated with a silicon oxide shell (NaYF4:20%Yb,0.2%Tm@SiO2) for biological and medical applications (for example, imaging of cancer cells and therapy at the nano level). The wide upconversion emission range under 980 nm excitation allows one to use the nanoparticles for cancer cell (4T1) photodynamic therapy (PDT) without a photosensitizer. The reactive oxygen species (ROS) are generated by Tm/Yb ion upconversion emission (blue and UV light). Thein vitroPDT was tested on 4T1 cells incubated with NaYF4:20%Yb,0.2%Tm@SiO2nanoparticles and irradiated with NIR light. After 24 h, cell viability decreased to below 10%, demonstrating very good treatment efficiency. High modification susceptibility of the SiO2shell allows for attachment of biological molecules (specific antibodies). In this work we attached the anti-human IgG antibody to silane-PEG-NHS-modified NaYF4:20%Yb,0.2%Tm@SiO2nanoparticles and a specifically marked membrane model by bio-conjugation. Thus, it was possible to perform a selective search (a high-quality optical method with a very low-level organic background) and eventually damage the targeted cancer cells. The study focuses on therapeutic properties of NaYF4:20%Yb,0.2%Tm@SiO2nanoparticles and demonstrates, upon biological functionalization, their potential for targeted therapy.

Multiparametric ultrasound examination for response assessment in breast cancer patients undergoing neoadjuvant therapy.

To investigate the performance of multiparametric ultrasound for the evaluation of treatment response in breast cancer patients undergoing neoadjuvant chemotherapy (NAC). The IRB approved this prospective study. Breast cancer patients who were scheduled to undergo NAC were invited to participate in this study. Changes in tumour echogenicity, stiffness, maximum diameter, vascularity and integrated backscatter coefficient (IBC) were assessed prior to treatment and 7 days after four consecutive NAC cycles. Residual malignant cell (RMC) measurement at surgery was considered as standard of reference. RMC < 30% was considered a good response and > 70% a poor response. The correlation coefficients of these parameters were compared with RMC from post-operative histology. Linear Discriminant Analysis (LDA), cross-validation and Receiver Operating Characteristic curve (ROC) analysis were performed. Thirty patients (mean age 56.4 year) with 42 lesions were included. There was a significant correlation between RMC and echogenicity and tumour diameter after the 3rd course of NAC and average stiffness after the 2nd course. The correlation coefficient for IBC and echogenicity calculated after the first four doses of NAC were 0.27, 0.35, 0.41 and 0.30, respectively. Multivariate analysis of the echogenicity and stiffness after the third NAC revealed a sensitivity of 82%, specificity of 90%, PPV = 75%, NPV = 93%, accuracy = 88% and AUC of 0.88 for non-responding tumours (RMC > 70%). High tumour stiffness and persistent hypoechogenicity after the third NAC course allowed to accurately predict a group of non-responding tumours. A correlation between echogenicity and IBC was demonstrated as well.

Direct Measurement of Hyperfine Shifts and Radio Frequency Manipulation of Nuclear Spins in Individual CdTe/ZnTe Quantum Dots.

We achieve direct detection of electron hyperfine shifts in individual CdTe/ZnTe quantum dots. For the previously inaccessible regime of strong magnetic fields B_{z}≳0.1 T, we demonstrate robust polarization of a few-hundred-particle nuclear spin bath, with an optical initialization time of ∼1 ms and polarization lifetime exceeding ∼1 s. Nuclear magnetic resonance spectroscopy of individual dots reveals strong electron-nuclear interactions characterized by Knight fields |B_{e}|≳50 mT, an order of magnitude stronger than in III-V semiconductor quantum dots. Our studies confirm II-VI semiconductor quantum dots as a promising platform for hybrid electron-nuclear spin qubit registers, combining the excellent optical properties comparable to III-V dots and the dilute nuclear spin environment similar to group-IV semiconductors.

Usefulness of combined BI-RADS analysis and Nakagami statistics of ultrasound echoes in the diagnosis of breast lesions.

AIM: To develop a method combining the statistics of the ultrasound backscatter and the Breast Imaging-Reporting and Data System (BI-RADS) classification to enhance the differentiation of breast tumours. MATERIALS AND METHODS: The Nakagami shape parameter m was used to characterise the scatter properties of breast tumours. Raw data from the radiofrequency (RF) echo-signal and B-mode images from 107 (32 malignant and 75 benign) lesions and their surrounding tissue were recorded. Three different characteristic values of the shape parameters of m (maximum [mLmax], minimum [mLmin] and average [mLavg]) and differences between m parameters (Δmmax, Δmmin, Δmavg) of the lesions and their surrounding tissues were assessed. A lesion with a BI-RADS score of 3 was considered benign, while a lesion with a score of 4 was considered malignant (a cut-off of BI-RADS 3/4 was set for all patients). RESULTS: The area under the receiver operating characteristic (ROC) curve (AUC) was equal to 0.966 for BI-RADS, with 100% sensitivity and 54.67% specificity. All malignant lesions were diagnosed correctly, whereas 34 benign lesions were biopsied unnecessarily. In assessing the Nakagami statistics, the sum of the sensitivity and specificity was the best for mLavg (62.5% and 93.33%, respectively). Only four of 20 lesions were found over the cut-off value in BI-RADS of 4a. When comparing the differences in m parameters, Δmavg had the highest sensitivity of 90% (only three of 32 lesions were false negative). These three lesions were classified as BI-RADS category 4c. The combined use of B-mode and mLmin parameter improve the AUC up to 0.978 (p=0.088), compared to BI-RADS alone. CONCLUSION: The combination of the parametric imaging and the BI-RADS assessment does not significantly improve the differentiation of breast lesions, but it has the potential to better identify the group of patients with mainly benign lesions that have a low level of suspicion for malignancy with a BI-RADS score of 4a.

[Antisense oligonucleotides for therapy of cystic fibrosis. Inhibition of sodium absorption mediated by ENaC in nasal epithelial cells]. / Antisense-Oligonukleotide zur Therapie der Mukoviszidose. Inhibition der ENaC-vermittelten Natriumabsorption in humanen Nasenepithelzellen.

BACKGROUND: The genetic disease cystic fibrosis (CF) is characterised by reduced chloride secretion mediated by the cystic fibrosis transmembrane conductance regulator (CFTR) and Na(+) hyperabsorption through amiloride-sensitive epithelial sodium channels (ENaC). Mutations in CFTR cause the accumulation of thick mucus and dysfunction of mucociliary clearance in the respiratory tract. MATERIAL AND METHODS: In this project it was investigated whether Na(+) hyperabsorption is inhibited by the use of antisense oligonucleotides (AON). For functional analyses monolayers of human non-CF and CF nasal epithelial cells were measured in modified Ussing chambers. To analyse the AON effects on the protein level Western blotting analyses were carried out. RESULTS: AON transfection significantly inhibits Na(+) absorption via ENaC in non-CF and CF cells. Furthermore, Western blot analyses demonstrate a suppression of the ENaC protein in AON transfected human non-CF cells. CONCLUSION: The inhibition of ENaC associated Na(+) absorption by specific AON could offer a new perspective for the regulation of the Na(+) hyperabsorption in CF patients.

The evaluation of parodontium in medical students of the Medical University of Bialystok according to CPITN index.

PURPOSE: The aim of the study was the evaluation of parodontium according to Community Peridental Index of Treatment Needs (CPITN) index in 455 students of The Medical and Dentistry Department of The Medical University of Bialystok. MATERIAL AND METHODS: After the examination, the students filled a survey according to their own project concerning hygienic habits as well as smoking, sweet intake. The results underwent statistical analysis. RESULTS: There were 1334 (48.86%) sextants observed with healthy parodontium in the studied population. Gingivorrhoea was stated in 440 sextants (16.12%), more often in men than in women. Calculus was reveled in 790 sextants (28.94%) of the population. The number of sextants with code 3 was 1.76%. Sextants with shallow pockets were more numerous in women (37 sextants) than in men (11 sextants). Advanced changes in parodontium (code 4) were observed in 9 sextants (0.33%). On the basis of the analysis of treatment needs in the group of 455 students, it can be stated that only 24.62% of the examined subjects did not need parodontium treatment. CONCLUSIONS: The diagnosis of parodontopathy and the factor that can have harmful influence on the parodontium tissues in young people is a superior criterion in the fight with irreversible parodontium changes in adults.

Allelic imbalance of BRCA1 transcript in the IVS20 12-bp insertion carrier.

One of the unclassified variants of the BRCA1 gene which has drawn considerable attention in recent years is the 12-bp insertion/duplication in intron 20. In this report, we show that a contribution from one chromosome cannot be detected in the BRCA1 transcript of the 12 bp insertion carrier. We also demonstrate here that the single transcript variant we observe by cDNA analysis originates from the same BRCA1 allele that harbours the 12-bp insertion. Hum Mutat 16:371, 2000.

High frequency of recurrent mutations in BRCA1 and BRCA2 genes in Polish families with breast and ovarian cancer.

Germ-line mutations in BRCA1 and BRCA2 genes result in a significantly increased risk of breast and ovarian cancer. Other genes involved in an increased predisposition to breast cancer include the TP53 gene, mutated in Li-Fraumeni syndrome. To estimate the frequency of germ-line mutations in these three genes in Upper Silesia, we have analyzed 47 breast/ovarian cancer families from that region. We found five different disease predisposing mutations in 17 (36%) families. Twelve families (25.5%) carried known BRCA1 mutations (5382insC and C61G), four families (8.5%) carried novel BRCA2 mutations (9631delC and 6886delGAAAA), and one family (2%) harbored novel mutation 1095del8 in the TP53 gene, which is the largest germline deletion in coding sequence of this gene identified thus far. The 5382insC mutation in BRCA1 was found in 11 families and the 9631delC mutation in BRCA2 occurred in three families. These two mutations taken together contribute to 82% of all mutations found in this study, and 30% of the families investigated harbor one of these mutations. The very high frequency of common mutations observed in these families can only be compared to that reported for Ashkenazi Jewish, Icelandic, and Russian high-risk families. This frequency, however, may not be representative for the entire Polish population. The observed distribution of mutations will favor routine pre-screening of predisposed families using a simple and cost-effective test.

Novel BRCA1 mutations and more frequent intron-20 alteration found among 236 women from Western Poland.

Three different novel BRCA1 mutations, five independent cases of the same 12 bp insertion-duplication in intron-20 and two novel rare BRCA1 sequence variants were identified among 122 Polish women with positive, in most cases moderate family history of breast and/or ovarian cancer, 80 controls and 34 unselected breast cancer tissue specimens. All mutations and variants were germline. The 4153 delA frameshift mutation, the Tyr105Cys missense mutation and two cases of the alteration in intron-20 were found in the group of healthy women with positive family history. Two other cases of the intronic insertion were found in unselected controls. Their carriers had no family history of breast or ovarian cancer but other cancers occurred in their families. The 1782 Trp/STOP nonsense mutation and one case of the insertion in intron-20 were first found in tissue specimens of breast cancer patient and breast/ovarian cancer patient, respectively. Their carriers also had no family history of breast or ovarian cancer. The distribution of the insertion in intron-20 in analysed groups and results of RT-PCR experiments suggest a less prominent role for this variant considered earlier a splicing mutation. This study shows also, that more population-oriented research is needed, involving women with less profound or even no family history of breast and ovarian cancer, to better understand the role and significance of different BRCA1 variants and mutations.

Faster and cheaper PCR on a standard thermocycler.

The PCR conditions have been optimized to make the process faster and more economical. When short DNA fragments are to be amplified, the time of denaturation, annealing and extension steps can be as short as 1 s each, and the yield of PCR product is still high, sufficient for many types of analysis. The PCR can be done even in a reaction volume as low as 1 microliter. The recommended volume, 2.5 microliters or 5 microliters, allows significant savings in the laboratory budget especially for laboratories which use PCR frequently and on a large scale.