Tuning the Colloidal Softness of CsPbBr Nanocrystals for Homogeneous Superlattices.

Perovskite nanocrystal superlattices (NC SLs), made from millions of ordered crystals, support collective optoelectronic phenomena. Coupled NC emitters are highly sensitive to the structural and spectral inhomogeneities of the NC ensemble. Free electrons in scanning electron microscopy (SEM) are used to probe the cathodoluminescence (CL) properties of CsPbBr SLs with a ∼20 nm spatial resolution.

The cumulative effects of polymorphisms in the DNA mismatch repair genes and tobacco smoking in oesophageal cancer risk.

The DNA mismatch repair (MMR) enzymes repair errors in DNA that occur during normal DNA metabolism or are induced by certain cancer-contributing exposures. We assessed the association between 10 single-nucleotide polymorphisms (SNPs) in 5 MMR genes and oesophageal cancer risk in South Africans. Prior to genotyping, SNPs were selected from the HapMap database, based on their significantly different genotypic distributions between European ancestry populations and four HapMap populations of African origin.

The somatostatin receptor subtype 2 is expressed in normal and tumoral human tissues70.

Somatostatin (SS) can inhibit growth hormone (GH) secretion from the pituitary and tumor cell proliferation via membrane-bound receptors (SST). Five SST subtypes have been cloned and can be discriminated by specific peptides. In order to evaluate the human tissue distribution of the SSTs, we first used the cross-linking assay with the 125I-SS-14.

Somatostatin-14 mainly binds the somatostatin receptor subtype 2 in human neuroblastoma tumors.

Neuroblastoma is a pediatric cancer for which a cure is elusive for most children with disseminated disease. Neuroblastomas possess receptors for somatostatin (SS). Some SS analogues can inhibit their proliferation.

Alteration of prostaglandin E receptors in advanced breast tumour cell lines.

We studied the direct effects of PGE2, often produced at high levels by mammary tumours, on three human breast cancer cell lines diversely advanced in malignancy regarding differentiation and tumorigenicity in nude mice. We evaluated PGE2 effect on cell growth, PGE2 receptor level and functionality. Our results show that PGE2 induces cAMP accumulation and inhibits the growth of the most differentiated breast cancer cells.

Long-term posttetantic changes in the reaction of neighboring neurons in microsegments of the cat motor cortex.

The long-term postsynaptic changes of mono- and polysynaptic reactions of neighboring neurons of the MC were investigated following conditioning tetanization of different afferent inputs. Modifiable synapses were found both in the cells investigated and in local neuronal circuits which included the cells, i.e.

Evidence for separate mechanisms of antiproliferative action of indomethacin and prostaglandin on MCF-7 breast cancer cells.

Indomethacin is reported to decrease the growth of many tumour cell lines. It is also known to be an anti-inflammatory agent acting by the inhibition of prostaglandin (PG) synthesis. To evaluate a clinical application as antitumoral agent, we have studied whether antiproliferative effect of indomethacin in breast cancer is related to its action on the prostaglandin production.

Neurobiology of the integrative activity of the brain: some properties of long-term posttetanic heterosynaptic depression in the motor cortex of the cat.

It has been demonstrated that long-term posttetanic heterosynaptic depression (LTHD), manifested in the form of a prolonged decrease in the probability of monosynaptic responses of the cell to stimulation of that afferent pathway which was not activated during conditioning tetanization of another input, takes place in the neocortex, as it does in the hippocampus. LTHD is characterized by such properties as its long-term character, cooperativity, and nonspecificity of input. LTHD in the nonconditioned input and long-term posttetanic potentiation or long-term posttetanic homosynaptic depression in the conditioned input may develop both in parallel or independantly of one another.

Proliferative responses of epithelial cells to 8-bromo-cyclic AMP and to a phorbol ester change during breast pathogenesis.

We have explored the relationship of changes in proliferative responses of human mammary epithelial cells to a phorbol ester (TPA) and to 8-Br-cAMP, which modulate the activities of protein kinases A and C (PKA and PKC), with breast tumour progression. Treatment with TPA had no effect on nontumorigenic cell lines established from human fibrocystic biopsies and apparently normal tissue around a tumour. In contrast, TPA strongly inhibited the proliferation of numerous human tumorigenic breast cell lines.

[Long-term posttetanic changes in the reaction of adjacent neurons in microareas of the cat motor cortex].

The long-term posttetanic changes of mono- and polysynaptic reactions of the neighbouring neurons in the microareas of the motor cortex were studied before and after conditioning tetanization of different afferent inputs to these neurons. Consecutive or conjoint conditioning of the thalamo-cortical and the cortico-cortical inputs could induce different changes in the efficiency of the synaptic inputs to the neighbouring neurons the effect depending on the modality of the conditioned input, the parameters of tetanization, the pattern of distribution of the afferent terminals on the dendritic tree and the character of the local circuits formed by the neurons under study and connected with them excitatory and inhibitory interneurons. As a result of such changes the new patterns of interneuronal connections could appear and be stable for tens of minutes.

Characterization of somatostatin receptors and growth inhibition by the somatostatin analogue BIM23014 in small cell lung carcinoma xenograft: SCLC-6.

Human small cell lung cancer (SCLC) is a neuroendocrine tumour with a very poor prognostic. Receptors for somatostatin-14 and its synthetic analogue BIM23014 (Lanreotide) were characterized in 3 human SCLC xenografts (SCLC-6, SCLC-10 and SCLC-75) transplanted in nude mice. The binding activity of both iodinated ligands was tested by cross-linking assay.

Evidence for a growth effect of epidermal growth factor on MDA-MB-231 breast cancer cells.

MDA-MB-231 is a breast epithelial cell line which possesses large amounts of epidermal growth factor (EGF) receptor on its cell surface but does not respond to EGF under standard culture conditions. 8-bromo-cyclic AMP (8Br-cAMP) and cholera-toxin treatments inhibit its growth by increasing its intracellular cAMP level. However, when inhibited in this way, MDA-MB-231 remains unresponsive to EGF.

[The properties of long-term posttetanic heterosynaptic depression in the cat motor cortex].

It is shown that in the neocortex (like in the hippocampus) the long-term heterosynaptic depression (LTD) may exist. The effect appears as a long-term decrease of the probability of the monosynaptic responses in the afferent input to the recorded neuron after the conditioning tetanization of the other afferent input to the same neuron. The main properties of the heterosynaptic LTD are its longevity, cooperativity and lack of input specificity.

[Prolonged homosynaptic depression of the impulse reactions of the motor cortex neurons in the cat].

It is shown that in the motor and the visual cortices of the cat the homosynaptic long-term posttetanic depression (LTD) of monosynaptic impulse responses of the cortical neurons may be induced in the tetanized input. Homosynaptic LTD appears as a decrease of the probability of the monosynaptic discharges or an increase in the latency of the monosynaptic responses. The cortical homosynaptic depression possesses the same properties as the hippocampal LTD, namely, the longevity, input specificity, cooperativity, and associativity.

Molecular heterogeneity of somatostatin analogue BIM-23014C receptors in human breast carcinoma cells using the chemical cross-linking assay.

Distinct proteins complexed with somatostatin and the somatostatin analogue BIM-23014C were revealed in human breast cancer cells using the cross-linking assay. One BIM-23014C-specific complex (Mr 57,000) was observed in MCF-7 (monolayer, nodule, and tumor) and T47D. Growth inhibition of MCF-7 tumor xenografts by BIM-23014C was dose related in the 6-day subrenal capsule assay.

Growth of human breast cancer cell lines is inhibited by the somatostatin analog BIM23014.

Somatostatin has been shown to lower plasma levels of various hormones and growth factors involved in regulation of the growth of human breast cells. In the present study we examined the ability of the somatostatin octapeptide analog BIM23014 to modulate the in vitro growth of five human breast cell lines: HBL100, Hs578T, MDAMB231, T47D, and MCF7. BIM23014 inhibited the growth of the two steroid-dependent cell lines, MCF7 and T47D, in a dose-related manner.

[Distribution of efferent neurons of different types in the motor cortex of the cat].

Distribution of efferent neurones of different categories was studied in the cat sensorimotor cortex: pyramidal and extrapyramidal systems and cortico-thalamic cells, whose axons end in the ventroposterolateral nucleus and medial geniculate body. In the major part of cortical microareas (88%) several output cells were found which could belong equally to one or several different categories. In some vertical cortical tracks no output neurones of the investigated categories were discovered.