Erythropoietin permits high-dose chemotherapy with peripheral blood stem-cell transplant for a Jehovah's Witness.
Explore the source record for details and available documents.
Adult↗
SEARCH · Search PubMed
Results for “Permits”
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Ultrastructural characterization of human herpesvirus 8 (Kaposi's sarcoma-associated herpesvirus) in Kaposi's sarcoma lesions: electron microscopy permits distinction from cytomegalovirus (CMV).
Kaposi's sarcoma (KS) has been shown by molecular techniques to be associated with infection with human herpesvirus 8 (HHV8/KSHV), but specific ultrastructural characterization of the virus has been impaired by the frequent presence in these lesions of other herpesviruses, particularly cytomegalovirus (CMV). Since the ultrastructural appearance of HHV8/KSHV has been studied in the cell line KS-1 uninfected with other viruses including CMV, it was possible to undertake a comparative study of CMV and HHV8/KSHV in KS lesions. HHV8/KSHV was sparsely present and lytic infection was restricted to endothelial cells. The following specific ultrastructural features allowed distinction between HHV8/KSHV and CMV: the viral particles were more delicate and less numerous in cases of HHV8/KSHV infection; the viral tegument was more electron-dense in CMV than in HHV8/KSHV; dense bodies characteristic of CMV were absent in HHV/KSHV; complete CMV viral particles were more variable in size and generally larger (150-200 nm) than HHV8/KSHV (120-150 nm); and finally, the viral envelope was more pleomorphic in CMV than in KSHV/HHV8. Similarities between CMV and HHV8/KSHV included the basic structure of the nucleocapsids and the presence of capsids lacking central DNA cores (so-called non-infectious enveloped particles). These observations show that electron microscopy can be used to identify HHV8/KSHV and confirm the relationship between HHV8/KSHV and KS.
Cytomegalovirus↗
Resistance to IL-1 anti-proliferative effect, accompanied by characteristics of advanced melanoma, permits invasion of human melanoma cells in vitro, but not metastasis in the nude mouse.
We reported earlier that IL-1 inhibits the growth of human melanoma cells (A375-6), and that these cells become resistant to IL-1 after prolonged periods of culture. The resistant cells constitutively produce IL-alpha and IL-6 with IL-6 production was induced by endogenous IL-1 in an autocrine manner. The cells are also resistant to IL-6 anti-proliferative effects. In the present study, we show that the resistant clones exhibited up-regulated expression of intercellular-adhesion molecule 1 (ICAM-1) and vitronectin receptor (integrin alpha(v)beta3) when compared with the IL-1-sensitive clone, A375-6. Moreover, these IL-1-resistant clones exhibited many other metastatic characteristics, such as expression of IL-8 mRNA, production of matrix metalloproteinases (MMP-2 and MMP-9), and augmented invasion activity. However, contrary to our expectations, the IL-1-resistant cells did not exhibit experimental metastasis in a nude-mouse model, similarly to the IL-1-sensitive parental A375-6 cell line. In contrast, the highly metastatic clone A375-SM exhibited alpha(v)beta3 expression at a level comparable to that of the IL-1-resistant cells, but expressed low or no ICAM-1, metalloproteinase and displayed little in vitro invasion activity. These results show that the metastatic characteristics of IL-1-resistant cells are not sufficient to produce metastasis in vivo and suggest that these resistant clones may provide a good model system for characterizing the molecular mechanisms of metastasis.
Animals↗
Optimal multi-stage designs for a phase II trial that permits one dose escalation.
Simon's optimal two-stage design is widely used to conduct single-dose phase II clinical trials. We extend this basic methodology to the situation where the researcher desires to test an experimental drug for activity at a low dose level, but is willing to increase the dose part-way through the trial if the early results suggest that the low dose is ineffective. Interest is confined to at most one dose escalation, and no consideration is given to escalating the dose within a patient. Optimal multi-stage designs are presented that are more efficient than the naive approach of merely conducting two consecutive Simon optimal trials, one at the low dose and the second (if deemed necessary) at the high dose. As in Simon's original design, toxicity is not considered here as a primary endpoint. Hence, the designs presented in this paper are appropriate only when the toxicity of the drug is well understood at both dose levels.
Algorithms↗
Sheath fluid control to permit stable flow in rapid mix flow cytometry.
BACKGROUND: Flow cytometry is a potentially powerful tool to analyze the kinetics of ligand binding, cell response and molecular assembly. The difficulty in adding reactant to cells, achieving adequate mixing, delivering those cells to the laser focal point and establishing stable flow, has historically limited flow cytometry to systems with reactions times longer than 5 s. With the advent of automated syringes and flow injection methods, sample injection times shorter than 1 s have become routine. However, an inherent problem in acquiring time courses starting under 1 s is that rapid sample introduction through the flow tip to the detection point perturbs laminar flow. The purpose of this work was to determine if stable flow could be reestablished more quickly if the sheath flow was reduced during sample introduction, returning to normal sheath and sample rates afterward. METHODS: We used programmable syringes and valves to control sample mixing as well as sheath and sample delivery through the flow tip to the detection point for stream-in-air detection. Stable flow was monitored by mean particle fluorescence during sample introduction. RESULTS: With no sheath reduction, stable flow recovered after more than 1 s. By reducing sheath flow during the short period (300 msec) of sample mixing and delivery, stable laminar flow recovered within 200 msec. CONCLUSIONS: This use of automated syringes to control both sheath and sample flow provides a potential for robust sample handling applicable to kinetic as well as high throughput flow cytometric analysis.
Automation↗
Insertion of natural intron 6a-6b into a human cDNA-derived gene therapy vector for cystic fibrosis improves plasmid stability and permits facile RNA/DNA discrimination.
BACKGROUND: The gene therapy vector pCMV-CFTR containing human CFTR cDNA shows high segregational instability during growth in Escherichia coli. METHODS: By host strain screening and optimization of fermentation, satisfactory levels of pCMV-CFTR production were achieved. However, the vector was also vulnerable to structural instability manifested by the appearance during fermentation of a more stable mutant form in which the bacterial insertion sequence IS1 had transposed into exon 7 of plasmidborne CFTR. The instability of pCMV-CFTR is attributable to transcription from an upstream cryptic promoter leading to the production of CFTR peptide fragments known to be toxic when expressed in E. coli. To address this, we inserted the 1.1 kb natural human 6a-6b intron into pCMV-CFTR. RESULTS: The new vector pCMV-CFTR-int6ab is more stable in E. coli than either pCMV-CFTR or the IS1 mutant, grows to high cell density giving higher DNA yields and expresses CFTR appropriately in transfected cells. Thus, the intron has a stabilizing effect comparable to the IS1 insertion yet retains full functionality for gene therapy. We describe a PCR assay using primers directed to sequences flanking the intron that allows differentiation between DNA and mature mRNA. The T936C mutation present only in vector DNA has also been exploited to allow transgene CFTR to be distinguished and its dose-dependent expression to be detected in human cellular backgrounds. CONCLUSIONS: Instability of a plasmid vector for gene therapy has been minimized by rational modification. The introduction of an intron for this purpose offers the additional advantage of providing a discriminatory RT-PCR assay.
Amino Acid Sequence↗
Circulating tumor-derived DNA may permit the early diagnosis of head and neck squamous cell carcinomas.
A series of eight microsatellite loci were assayed for both loss of heterozygosity and new mutated alleles in 91 head and neck squamous cell carcinomas. In 58 cases, alterations were detected and used as markers for assaying the presence of circulating tumor-derived DNA in the patients' plasma. This was unambiguously detected in 17 cases. The probability of detecting circulating DNA was independent of tumor stage and was found to be present even in some individuals with stage I tumors. The presence of such DNA, however, could not be correlated with disease outcome or other significant clinical parameters, suggesting that it has no prognostic significance. The results indicate that circulating tumor-derived DNA could be used as a means of early diagnosis of head and neck tumors.
Alleles↗
Chondrogenic potential of chick embryonic calvaria: I. Low calcium permits cartilage differentiation.
Calvaria from day-14 calcium-deficient chick embryos produced by long-term maintenance in shell-less culture, exhibit a cartilage-like phenotype (Jacenko and Tuan [1986] Dev. Biol. 115:215-232), which is restored to an osteogenic phenotype upon calcium repletion to the embryo. The expression of cartilage markers in a typically osteogenic tissue under calcium deficiency implies the presence of chondrogenic cells, and questions the conditions associated with calcium deficiency which may cause their divergent pathway of differentiation. In the present study, by explanting normal and shell-less embryonic calvarial pairs in organ culture in vitro and experimentally regulating their calcium supply, the calcium status of the calvaria was modulated as a function of medium calcium. Histological and immunoblotting analyses demonstrated for the first time that calvaria possess cells which can form genuine cartilage. This chondrogenic potential is expressed only in a low-calcium environment, where cartilage forms in both normal and shell-less calvarial pairs; their calcium-supplemented counterparts, however, develop as fully osteogenic tissues. Furthermore, chondrogenesis in both normal and shell-less calvaria indicates that the chondrogenic cells must be endogenous constituents of the calvaria, rather than being derived elsewhere in response to systemic calcium deficiency. Finally, the correlation between matrix under-calcification and cartilage expression in the embryonic calvarium suggests that calcium, perhaps in the form of matrix mineral, may modulate cell differentiation during skeletogenesis.
Animals↗
Trivial influences: a doubly stochastic Poisson process model permits the detection of arbitrarily small electromagnetic signals.
If a weak, exogenous, extremely low-frequency (ELF) electric or magnetic field is to produce biological sequelae, then there must exist averaging sufficient to lift some primary effect of that field above the endogenous stochastic variations of the biological system. One way in which a field could accomplish this is by changing the intensity of some stochastic operation that controls an important and not trivially reversible biological transformation. In this paper, this operation is modeled as a doubly stochastic Poisson process. It is then shown, first, that (in theory) even a minuscule exogenous influence might appreciably shift the incidence of a sufficiently rare transformation and, second, that this shift might be observable if a trial were allowed to run long enough over a sufficiently large population of exposed entities.
Algorithms↗
The serum sodium concentration after surgical operation: precision permits predictions.
In view of previous conflicting reports, the distribution of a water overload was investigated in 6 healthy volunteers. The fall in serum sodium was predictable from prior measurement of total body water (tritium) confirming that the induced hyponatraemia was dilutional. Using a standard intravenous fluid regimen, a prospective study for 6 days on 50 patients undergoing major abdominal surgery established a confidence band for change in serum sodium concentration. This band not only enables precise prediction of whether observed sodium values in patients are "normal' for that point in their postoperative course, but also demonstrates that changes are more prolonged than was at first thought. Their dilutional nature following uncomplicated surgery is supported by linear relationships between serum osmolality and serum sodium (s-Osm = 1.86 [s-Na+] + 18:74; (P < 0.001) and between observed and calculated osmolality (Obs-Osm = 0.97 [Calc-Osm] + 15.11; P < 0.001). More detailed investigation of 14 patients by isotope dilution provided independent evidence of dilutional change. This conclusion is additionally supported by lesser changes in patients on a more restricted fluid regimen. As a practical confirmation of the utility of this approach, departures from the simple dilutional relationships were observed in 7 critically ill patients whose postoperative course was complicated. In this group osmolal "gags' of 20-50 mosmol/kg were identified. Current standard postoperative fluid regimens cause dilutional changes; these are predictable and provide a yardstick for use in management of both the healthy and the ill surgical patient.
Adult↗
Inhibition of formation of a glial barrier as a means of permitting a peripheral nerve to grow into the brain.
Explore the source record for details and available documents.
Brain↗
An epiiluminator/detector unit permitting arc lamp illumination for fluorescence activated cell sorters.
The application of arc lamps to flow cytometers is discussed and epiillumination for jet-in-air cell sorters is introduced. An epiilluminator/detector unit equipped with a mercury arc lamp constructed for a commercially available cell sorter is described. Experiments in which laser and mercury arc lamp illumination were compared show that the signal-to-noise ratio for the arc lamp illumination is predominantly limited by shot noise from constant light backgrounds due to reflected excitation light and ambient light. Arc lamp illumination can be used for the sorting of highly fluorescent objects such as cells stained for DNA by for example: ethidium bromide, propidium iodide, or the Hoechst dyes. The simultaneous employment of mercury arc and laser light sources as an inexpensive dual wavelength system is discussed.
Cell Separation↗
PTEN permits acute increases in D3-phosphoinositide levels following TCR stimulation but inhibits distal signaling events by reducing the basal activity of Akt.
Phosphoinositide 3-kinase (PI3K) is important in TCR signaling. PI3K generates phosphatidylinositol 3, 4, 5-trisphosphate (PI-3,4,5-P3), which regulates membrane localization and/or activity of multiple signaling proteins. PTEN (phosphatase and tensin homologue deleted on chromosome 10) opposes PI3K, reversing this reaction. Maintaining the balance between these two enzymes is important for normal T cell function. Here we use the PTEN-null Jurkat T cell line to address the role of PTEN in modulating proximal and distal TCR-signaling events. PTEN expression at levels that restored low basal Akt phosphorylation (an indicator of PI-3,4,5-P3 levels), but which were not themselves cytotoxic, had minimal effect on TCR-stimulated activation of phospholipase Cgamma1 and Ca2+ flux, but reduced the duration of extracellular signal-regulated kinase (Erk) activation. Distal signaling events, including nuclear factor of activated T cells (NFAT) activation, CD69 expression and IL-2 production, were all inhibited by PTEN expression. Notably, PTEN did not block TCR-stimulated PI-3,4,5-P3 accumulation. The effect of PTEN on distal TCR signaling events was strongly correlated with the loss of the constitutive Akt activation and glycogen synthase kinase-3 (GSK3) inhibition that is typical of Jurkat cells, and could be reversed by expression of activated Akt or pharmacologic inhibition of GSK3. These results suggest that PTEN acts in T cells primarily to control basal PI-3,4,5-P3 levels, rather than opposing PI3K acutely during TCR stimulation.
Androstadienes↗
CDKN2A, CDKN2B, and MTAP gene dosage permits precise characterization of mono- and bi-allelic 9p21 deletions in childhood acute lymphoblastic leukemia.
Deletion of the 9p21 chromosomal region is frequently found in childhood acute lymphoblastic leukemia (ALL). The target of these deletions is CDKN2A, a gene encoding both p16(INK4a) and p14(ARF). However, contiguous genes such as CDKN2B, encoding p15(INK4b), or MTAP, encoding methylthioadenosine phosphorylase, can be included in the deletions. Gene dosage by use of real-time PCR has recently been proposed as a promising technical option for the diagnosis of deletions. However, its reliability and its capacity to detect mono-allelic deletions in tumor samples are controversial. To evaluate the frequency and extent of deletions in 284 children with ALL, we devised a real-time PCR assay for CDKN2A, CDKN2B exons 1beta and 3, and MTAP gene dosage and validated it by comparison with loss-of-heterozygosity analysis. We show that, if several controls and adjustments are performed, real-time PCR can provide a reliable test for mono- and bi-allelic deletions in ALL. We propose a strategy that overcomes the major caveats of such a dosage in tumor samples: aneuploidy and contamination by normal cells. By use of this assay, we found bi-allelic deletions in 58 and 17% of T- and B-lineage ALL, respectively. Mono-allelic deletion was observed in about 15% of cases, stressing the importance of their detection in ALL. CDKN2B and/or MTAP co-deletions were highly variable in both T- and B-lineage ALL, making ALL with 9p21 a rather heterogeneous group. Because proteins encoded by these genes might influence the response to treatment, the prognosis of 9p21-deleted ALL could vary according to the extent of the deletion.
Adolescent↗
Premature chromosome condensation revisited: a novel chemical approach permits efficient cytogenetic analysis of cancers.
Chemical induction of premature chromosome condensation (PCC) was investigated and optimized to be able to analyze the chromosomal constitution of cancer cells independent of mitosis and with minimal culture artifacts. A potent protein phosphatase inhibitor, calyculin A, was used to induce PCC in normal diploid cells, in several established human tumor cell lines, and in cells isolated from freshly dissected adenomatous polyps of a patient with hereditary colorectal cancer. In parallel, mitotic arrest was pursued by use of Colcemid. In cell lines, a difference of up to 10-fold was found between frequency of cells with PCC induced by calyculin A (PCC index) and the mitotic index after treatment with Colcemid. In the fresh tumor specimens, Colcemid failed to result in metaphase formation, whereas a regimen of 80 nM calyculin A for 75 min, after only 2 days of culturing, resulted in a PCC index of 2-5%. pq-COBRA-FISH (COmbined Binary RAtio labeling-fluorescence in situ hybridization) was used for a detailed analysis of four cell lines treated with calyculin A, which proved that PCC spreads are amenable to molecular karyotyping, and a comparison between PCC spreads and metaphases from mitotic arrest revealed no discrepancies in karyotypes. pq-COBRA-FISH on PCC spreads from fresh colon tumor samples revealed only numerical and no structural abnormalities. Calyculin A-induced PCC combined with multicolor FISH gives a new opportunity for analysis of the chromosomal constitution of G(1) and G(2) cancer cells and may find application in the study of the role of chromosome instability in cancer development.
Adenomatous Polyposis Coli↗
Characterization of fly strains permitting GAL4-directed expression of found in neurons.
Explore the source record for details and available documents.
Animals↗
Functional magnetic resonance imaging of verbal fluency and confrontation naming using compressed image acquisition to permit overt responses.
Verbal fluency and confrontation naming, two tests of word retrieval, are of great utility in the field of cognitive neuroscience. However, in the context of functional magnetic resonance imaging (fMRI), movement artefact has necessitated the use of covert paradigms, which has limited clinical application. We developed two overt fMRI paradigms that allowed for performance measurement and hence were appropriate for use with patient groups. The paradigms incorporated a blocked-design and compressed-acquisition methodology where cues were presented and responses made in a "silent" period allowing for performance measurement. The slow response pace was specifically designed for older and potentially cognitively impaired participants. Verbal fluency was associated with activation in the middle frontal gyrus (Brodmann areas 46 and 9), anterior cingulate gyrus and inferior frontal gyrus (area 44 and 45). Confrontation naming activated areas of the temporo-occipital cortices (areas 18, 19, and 37) and the inferior frontal gyrus. The two paradigms successfully activated regions involved in executive and word retrieval processes and overcame the potential artefacts resulting from overt speech during image acquisition, providing useful neuropsychological tools to investigate cognitive deficits in clinical populations.
Acoustic Stimulation↗
Kupffer cell depletion abolishes induction of interleukin-10 and permits sustained overexpression of tumor necrosis factor alpha messenger RNA in the regenerating rat liver.
Tumor necrosis factor alpha (TNF), initiates a cytokine cascade that promotes hepatocyte proliferation after 70% partial hepatectomy (PH) but the mechanisms regulating TNF production after PH are unknown. We previously reported that gadolinium chloride (GdCl), an agent that depletes the liver of phagocytically active Kupffer cells, enhances hepatic expression of TNF messenger RNA (mRNA) and promotes liver regeneration after subsequent PH. This suggests that GdCl interferes with Kupffer cell mechanisms that normally constrain TNF production after PH. To evaluate this, the pre- and post-PH expression of TNF, TNF-inducible cytokines (interleukin [IL]-1, IL-6) and cytokines (transforming growth factor [TGF] beta 1 and IL-10) that down-regulate TNF were compared in controls and GdCl-treated rats. In controls, TNF, IL-1, IL-6, and IL-10 increase within 3 hours after PH, whereas TGF-beta 1 is induced much later (> 24 hours after PH). GdCl causes sustained overexpression of TNF mRNA and transient overexpression of circulating TNF protein after PH; both TNF-inducible cytokines are also relatively overexpressed. Cytokines that down-regulate TNF are effected differentially by GdCl. Regenerative induction of IL-10 is abolished but TGF-beta 1 induction is unaltered. Because IL-10 is known to shorten the half-life of TNF mRNA, these results suggest that Kupffer cell production of IL-10 is an important mechanism that down-regulates TNF production during liver regeneration.
Animals↗