Complexation Peculiarities in “Doxorubicin–Bovine Serum Albumin–Gold Nanoparticles” Heterosystem. The Fluo-rescence Study

The fluorescence (FL) quenching in aqueous solutions of doxorubicin (DOX)–bovine serum albumin (BSA)–gold nanoparticles (AuNPs) is studied. The existence of additional mechanisms of DOX-BSA complex formation leading to an increase in the binding constant K and a decrease in the number of binding sites n and the distance between the fluorophore and energy acceptors due to the presence of gold nanoparticles is shown.

Resin Infiltration into Differentially Extended Experimental Carious Lesions

Resin infiltration of initial caries lesions is a novel method of caries therapy. However, it has some limitations. Therefore, further experimental studies are needed to improve resin infiltration. It was the aim of this investigation to study resin infiltra-tion into different experimental carious lesions. Caries-free extracted human molars and premolars were demineralized for 3, 6, 9 and 12 days and infiltrated with resin. Prior to infiltration, the teeth were incubated with sodium fluorescein. After em-bedding, serial sections were cut through the experimental lesions, and the penetration of the resin was measured with fluo-rescence microscopy. Two infiltrated teeth from each time interval were not embedded and cut. Infiltration of the resin was then studied with EDS element analysis. The results showed that with increasing demineralization time, the lesion expansion was also increasing, and the resin infiltration was always almost complete. From these results it can be concluded that artifi-cial standardized caries-like lesions are suitable for experimental studies of resin infiltration.

Coexistence of trisomy 12 and del(13)(q14.3) in two patients with chronic lymphocytic leukemia

We describe two patients with diagnosis of chronic lymphocytic leukemia (CLL) in whom interphase fluo?rescence in situ hybridization (FISH) analysis revealed trisomy 12 and del(13)(q14.3) occurring in the same clone. These abnormalities are rarely seen together and the prognostic relevance of their coexistence is still unclear. According to some data, a probable adverse prognosis for this group of patients is suggested. Our patients have been in a stable phase of the disease for more than one year since the given abnormalities were documented in their karyotypes. Further study is necessary to determine the prognostic significance of coexistence of these abnormalities in CLL patients.

Stimulation of Combinatorial Expression of Prolactin and Glycoprotein Hormone α-Subunit Genes by Gonadotropin-Releasing Hormone and Estradiol-17β in Single Rat Pituitary Cells during Aggregate Cell Culture

Previously we showed the existence of rat and mouse anterior pituitary cells coexpressing mRNA from two or more hormone genes in which production and/or storage of the corresponding hormones were not detectable. To substantiate a putative function for these cells, we investigated whether these phenotypes were retained during long-term reaggregate cell culture and whether protagonist regulatory factors could expand cell populations expressing particular hormone mRNA combinations. After 4-wk culture and treatments, aggregates were trypsinized and single cells collected by means of a fluo-rescence-activated cell sorter. Hormone mRNAs were detected by single-cell RT-PCR. Combinatorial hormone mRNA expression was retained in culture. Both estradiol (E2) and GnRH (1 nm) markedly augmented the proportion of cells expressing prolactin (PRL) mRNA together with other hormone mRNAs and cells expressing glycoprotein subunit (GSU)-α mRNA together with other hormone mRNAs. GnRH strongly increased the proportion of cells containing αGSU mRNA alone, but E2 did not. GnRH and (E2) affected the expansion of a population (∼20% of all cells) coexpressing PRL and αGSU mRNA without βGSUs. Immunostaining of stored hormone on tissue sections revealed colocalization of PRL and αGSU in the E2- but not in the GnRH-treated cells. The present findings suggest that cells coexpressing different pituitary hormone mRNAs form a distinct population that survives without extrapituitary factors. Their occurrence can be markedly modified by regulatory factors. Certain hormone regimens favor unique coexpressions distinctly at mRNA and protein level. These peculiar characteristics support the notion that combinatorial expression of hormone genes in the pituitary serves a biological role.

Über die Fluoreszenzfähigkeit von Triphenylcarboniumderivaten / Fluorescence Yields of Triphenylcarbonium Derivatives

The absolute fluorescence yields of triphenylcarbonium derivatives are correlated with the change of bond order between central-C-atom and phenyl group during the electronic transition. The fluo rescence yield is reduced by a rotation of the phenyl group only if the π-electron system of the phenyl group is sufficiently strong coupled to the other part of the molecule. The change of bond order can be assumed as a measure for the coupling.