EEG source analysis and fMRI reveal two electrical sources in the fronto-parietal operculum during subepidermal finger stimulation.

Using functional magnetic resonance imaging (fMRI) and electroencephalographic (EEG) source dipole analysis in 10 normal subjects, two electrical source dipoles in the contralateral fronto-parietal operculum were identified during repetitive painful subepidermal stimulation of the right index finger. The anterior source dipole peaking at 79 +/- 8 ms (mean +/- SD) was located in the frontal operculum, and oriented tangentially toward the cortical surface. The posterior source dipole peaking at 118 +/- 12 ms was located in the upper bank of the Sylvian fissure corresponding to the second somatosensory cortex (S2).

Creation of a BAC resource to study the structure and evolution of the banana (Musa balbisiana) genome.

The first bacterial artificial chromosome (BAC) library of the banana species Musa balbisiana 'Pisang Klutuk Wulung' (PKW BAC library) was constructed and characterized. One improved and one novel protocol for nuclei isolation were employed to overcome problems caused by high levels of polyphenols and polysaccharides present in leaf tissues. The use of flow cytometry to purify cell nuclei eliminated contamination with secondary metabolites and plastid DNA.

MCL1 is phosphorylated in the PEST region and stabilized upon ERK activation in viable cells, and at additional sites with cytotoxic okadaic acid or taxol.

BCL2 family members are subject to regulation at multiple levels, providing checks on their ability to contribute to tumorigenesis. However, findings on post-translational BCL2 phosphorylation in different systems have been difficult to integrate. Another antiapoptotic family member, MCL1, exhibits a difference in electrophoretic mobility upon phosphorylation induced by an activator of PKC (12-O-tetradecanoylphorbol 13-acetate; TPA) versus agents that act on microtubules or protein phosphatases 1/2A.

Analysis and sorting of rye (Secale cereale L.) chromosomes using flow cytometry.

Procedures for chromosome analysis and sorting using flow cytometry (flow cytogenetics) were developed for rye (Secale cereale L.). Suspensions of intact chromosomes were prepared by mechanical homogenization of synchronized root tips after mild fixation with formaldehyde.

Desynchronization of cortical rhythms following cutaneous stimulation: effects of stimulus repetition and intensity, and of the size of corpus callosum.

Objective: Event-related desynchronization (ERD) and synchronization (ERS) of the Rolandic electroencephalographic (EEG) rhythms following brief, innocuous electrocutaneous stimulation were studied with respect to stimulus intensity and repetition and the size of corpus callosum (CC).

Methods: EEG was recorded using 82 closely spaced electrodes in 13 right-handed subjects. The subjects received 650 brief electrical stimuli to the right index finger at irregular intervals (6-12 s) in 5 blocks.

Flow karyotyping and chromosome sorting in bread wheat ( Triticum aestivum L.).

Previously, we reported on the development of procedures for chromosome analysis and sorting using flow cytometry (flow cytogenetics) in bread wheat. That study indicated the possibility of sorting large quantities of intact chromosomes, and their suitability for analysis at the molecular level. However, due to the lack of sufficient differences in size between individual chromosomes, only chromosome 3B could be sorted into a high-purity fraction.

Development of flow cytogenetics and physical genome mapping in chickpea (Cicer arietinum L.).

Procedures for flow cytometric analysis and sorting of mitotic chromosomes (flow cytogenetics) have been developed for chickpea (Cicer arietinum). Suspensions of intact chromosomes were prepared from root tips treated to achieve a high degree of metaphase synchrony. The optimal protocol consisted of a treatment of roots with 2 mmol/L hydroxyurea for 18 h, a 4.

Source activity in the human secondary somatosensory cortex depends on the size of corpus callosum.

If corpus callosum (CC) mediates the activation of the secondary somatosensory area (SII) ipsilateral to the side of stimulation, then the peak latencies of the contra- and ipsilateral SII activity as well as the amplitude of the ipsilateral SII activity should correlate with the size of CC. Innocuous electrical stimuli of five different intensities were applied to the ventral surface of the right index finger in 15 right-handed men. EEG was recorded using 82 closely spaced electrodes.

Chromosome sorting and PCR-based physical mapping in pea (Pisum sativum L.).

Three pea lines with reconstructed karyotypes were used for analysis and subsequent purification of individual chromosome types using flow cytometry and sorting. The lines JI 145, JI 146, and JI 148 possess defined chromosomal translocations allowing discrimination of three to four chromosome types from each line based on the different sizes of translocation chromosomes. Whereas only two chromosomes could be sorted from standard (wild-type) karyotype, a combined use of these lines allowed sorting of six out of the seven types of pea chromosomes.

An MCL1-overexpressing Burkitt lymphoma subline exhibits enhanced survival on exposure to serum deprivation, topoisomerase inhibitors, or staurosporine but remains sensitive to 1-beta-D-arabinofuranosylcytosine.

Members of the BCL2 gene family influence cell viability and can, therefore, affect the susceptibility of cancer cells to multiple chemotherapeutic agents. Thus, it is a challenge to devise approaches for inducing the death of tumor cells in which the expression of prosurvival family members is elevated or deregulated. BL41-3, a spontaneously derived subline of BL41 Burkitt lymphoma cells, was found to have amplified the prosurvival MCL1 gene (3-fold) and overexpressed the MCL1 protein.

Localisation of DNA sequences on plant chromosomes using PRINS and C-PRINS.

Localisation of DNA sequences to plant chromosomes in situ has traditionally been accomplished using fluorescence in situ hybridisation (FISH). Although the method is suitable for most applications it is time-consuming and requires labelled probes. Recently, primed in situ labelling (PRINS) has been developed as an alternative to FISH.

Localization of male-specifically expressed MROS genes of Silene latifolia by PCR on flow-sorted sex chromosomes and autosomes.

The dioecious white campion Silene latifolia (syn. Melandrium album) has heteromorphic sex chromosomes, XX in females and XY in males, that are larger than the autosomes and enable their separation by flow sorting. The group of MROS genes, the first male-specifically expressed genes in dioecious plants, was recently identified in S.

Synergistic induction of apoptosis in human leukemia cells (U937) exposed to bryostatin 1 and the proteasome inhibitor lactacystin involves dysregulation of the PKC/MAPK cascade.

Cotreatment with a minimally toxic concentration of the protein kinase C (PKC) activator (and down-regulator) bryostatin 1 (BRY) induced a marked increase in mitochondrial dysfunction and apoptosis in U937 monocytic leukemia cells exposed to the proteasome inhibitor lactacystin (LC). This effect was blocked by cycloheximide, but not by alpha-amanitin or actinomycin D. Qualitatively similar interactions were observed with other PKC activators (eg, phorbol 12-myristate 13-acetate and mezerein), but not phospholipase C, which does not down-regulate the enzyme.

Flow sorting of mitotic chromosomes in common wheat (Triticum aestivum L.).

The aim of this study was to develop an improved procedure for preparation of chromosome suspensions, and to evaluate the potential of flow cytometry for chromosome sorting in wheat. Suspensions of intact chromosomes were prepared by mechanical homogenization of synchronized root tips after mild fixation with formaldehyde. Histograms of relative fluorescence intensity (flow karyotypes) obtained after the analysis of DAPI-stained chromosomes were characterized and the chromosome content of all peaks on wheat flow karyotype was determined for the first time.

Rapid identification and determination of purity of flow-sorted plant chromosomes using C-PRINS.

Background: Flow-sorted plant chromosomes are being increasingly used in plant genome analysis and mapping. Consequently, there is a need for a rapid method for identification of sorted chromosomes and for determination of their purity. We report on optimization of procedures for primed in situ DNA labeling (PRINS) and cycling-PRINS (C-PRINS) for fluorescent labeling of repetitive DNA sequences on sorted plant chromosomes suitable for their identification.

Altered sensitivity to single-strand-specific reagents associated with the genomic vascular smooth muscle alpha-actin promoter during myofibroblast differentiation.

Stimulation of quiescent AKR-2B mouse fibroblasts with transforming growth factor beta1 results in uniform conversion to a myofibroblast-like phenotype as judged by a rapid accumulation of smooth muscle alpha-actin mRNA and protein. Because transcriptional regulation of the smooth muscle alpha-actin gene in these cells might be mediated by single-stranded DNA-binding proteins, we have examined the sensitivity of genomic DNA to chemical reagents with specificity for unpaired bases in a region of the promoter previously implicated in Puralpha, Purbeta, and MSY1 binding in vitro (Kelm, R. J.

Inhibition of the mitogen activated protein kinase pathway potentiates radiation-induced cell killing via cell cycle arrest at the G2/M transition and independently of increased signaling by the JNK/c-Jun pathway.

The ability of low dose ionizing radiation (2 Gy) to modulate the activities of the mitogen activated protein kinase (MAPK) and c-Jun NH2-terminal kinase (JNK1) cascades in human monocytic leukemia (U937/pREP4) cells and in cells over-expressing dominant negative c-Jun (TAM67) (U937/TAM67) was investigated. Radiation exposure caused prolonged ( approximately 1 h) MAPK activations in U937 cells. In contrast, low dose irradiation weakly modulated JNK1 activity in these cells.

Induction of apoptosis in U937 human leukemia cells by suberoylanilide hydroxamic acid (SAHA) proceeds through pathways that are regulated by Bcl-2/Bcl-XL, c-Jun, and p21CIP1, but independent of p53.

Determinants of differentiation and apoptosis in myelomonocytic leukemia cells (U937) exposed to the novel hybrid polar compound SAHA (suberoylanilide hydroxamic acid) have been examined. In contrast to hexamethylenbisacetamide (HMBA), SAHA-related maturation was limited and accompanied by marked cytoxicity. SAHA-mediated apoptosis occurred within the G0G1 and S phase populations, and was associated with decreased mitochondrial membrane potential, caspase-3 activation, PARP degradation, hypophosphorylation/cleavage of pRB, and down-regulation of c-Myc, c-Myb, and B-Myb.

Inhibition of protein kinase C activator-mediated induction of p21CIP1 and p27KIP1 by deoxycytidine analogs in human leukemia cells: relationship to apoptosis and differentiation.

Events accompanying sequential exposure of U937 leukemic cells to the deoxycytidine (dCyd) analogs 1-[beta-D-arabinofuranosyl]cytosine (ara-C) or 2',2'-difluorodeoxycytidine (gemcitabine; dFdC) followed by two protein kinase C (PKC) activators [bryostatin 1 (BRY) or phorbol 12'-myristate 13'-acetate (PMA)] exhibiting disparate differentiation-inducing abilities were characterized. A 24-hr exposure to 10 nM BRY or PMA after a 6-hr incubation with 1 microM ara-C or 100 nM dFdC resulted in equivalent increases in apoptosis, caspase-3 activation, and polyADP-ribose polymerase degradation, as well as identical DNA cleavage patterns. BRY and PMA did not modify retention of the lethal ara-C metabolite ara-CTP or alter ara-CTP/dCTP ratios.

Induction of apoptosis and differentiation by fludarabine in human leukemia cells (U937): interactions with the macrocyclic lactone bryostatin 1.

We have examined interactions between the purine nucleoside analog fludarabine (9-beta-arabinofuranosyl-2-fluoroadenine) and the macrocyclic lactone bryostatin 1 in the human monocytic leukemic cell line U937. Fludarabine exerted dose-dependent effects on U937 cell viability and growth which were associated with both induction of apoptosis, as well as cellular maturation. Incubation of cells with bryostatin 1 (10 nM; 24 h) after, but not before a 6-h exposure to 10 microM fludarabine resulted in a modest but significant increase in apoptosis, and was associated with greater than a 1 log reduction in clonogenicity.

Inhibition of the MAPK pathway abrogates BCL2-mediated survival of leukemia cells after exposure to low-dose ionizing radiation.

The ability of low-dose ionizing radiation (1 Gy) to modulate the activities of the mitogen-activated protein kinase (MAPK) and Jun NH2-terminal kinase (JNK1) cascades in human myeloid leukemia (HL60/pCEP4) cells and in cells overexpressing the anti-apoptosis protein BCL2 (HL60/Bcl-2) was investigated. Radiation exposure caused prolonged (3-4 h) activation of MAPK in HL60 cells. The ability of radiation to activate the MAPK pathway was attenuated by 30% in cells overexpressing BCL2.

Neurotoxicity of tetraphenylporphinesulfonate (TPPS4) and a hematoporphyrin derivative (Photosan) in organotypic cultures of chick embryonic dorsal root ganglia.

The neurotoxic effect of tetraphenylporphinesulfonate (TPPS4) and a hematoporphyrin derivative (HPD, Photosan) has been studied in organotypic cultures of chick dorsal root ganglia maintained in a semi-solid culture medium. The changes in two characteristics of neurite outgrowth, the mean radial length of neurites growing out from the ganglia and the area of neurite outgrowths, are used as parameters to evaluate the toxic effect. The porphyrins are tested over the concentration range 10-160 micrograms ml-1.

Neurotoxic effect of cisplatin and the cisplatin-procaine complex DPR studied in organotypic cultures of chick embryonic dorsal root ganglia.

Neurotoxic effects of cisplatin and the cisplatin-procaine complex cis-diaminechloro-[2-(diethylamino)ethyl 4-aminobenzoate, N4]-chlorideplatinum(II) monohydrochloride monohydrate (DPR) were compared in organotypic cultures of chick embryonic dorsal root ganglia maintained in a semi-solid (soft agar) culture medium. The changes of two characteristics of the neurite outgrowth, the mean radial length of neuritic processes growing out from the ganglia and the area of neurite outgrowth around the ganglion, were used as parameters to evaluate the toxic effect of both compounds. The drugs were administered to the cultures at concentrations ranging from 13 to 120 microM.

Divergent effects of bryostatin 1 and phorbol myristate acetate on cell cycle arrest and maturation in human myelomonocytic leukemia cells (U937).

Bryostatin 1 and the phorbol ester, phorbol myristate acetate (PMA), both bind to and activate protein kinase C (PKC) but exhibit divergent biological actions. Bryostatin 1 exerts variable effects on leukemic cell differentiation, and has been reported by some investigators to inhibit the proliferation of the monocytic leukemic cell line U937. In this study, we have compared the efficacy of bryostatin 1 and PMA with respect to U937 cell maturation, with a major emphasis on differential actions on the cell cycle arrest machinery.