Effect of nearest-neighbor ions on excited ionic states, emission spectra, and line profiles in hot and dense plasmas.
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Journal Article↗
Biomedical subjects
J Stein
Publications and source records attributed to J Stein.
Isolation and characterization of a cDNA from a human histone H2B gene which is reciprocally expressed in relation to replication-dependent H2B histone genes during HL60 cell differentiation.
A variant human histone H2B cDNA (HHC289) has been cloned and characterized and shown to have a complex pattern of regulation with respect to the HeLa S3 cell cycle and HL60 cell differentiation. The H2B protein coding region of HHC289 is flanked at the 3' end by a 1798-nt nontranslated trailer that contains a region of hyphenated dyad symmetry and a poly(A) addition sequence, followed by a poly(A) tail. Nuclear run-on transcription analysis revealed a 2-fold increase in transcription of the HHC289 gene during S phase, in comparison to replication-dependent human histone genes which exhibit a 2-3-fold increase in transcription during S phase. Northern blot analysis indicated that the levels of the 2300-nt HHC289 mRNA species did not vary significantly during the HeLa S3 cell cycle, in comparison to replication-dependent H2B mRNAs which are elevated 15-fold during S phase. Northern blot analysis also revealed a reciprocal relationship during the onset of HL60 differentiation between the expression of the HHC289 H2B gene and the replication-dependent H2B genes. The levels of the 2300-nt HHC289 H2B species increased approximately 10-fold during HL60 cell differentiation whereas the levels of cell cycle dependent H2B mRNAs decreased to less than 1% of those in proliferating cells. These results suggest that complex transcriptional and posttranscriptional regulatory mechanisms control cellular levels of mRNAs from various human H2B histone genes during progression through the cell cycle and at the onset of differentiation.
Amino Acid Sequence↗
Disruption of the cytoskeleton with cytochalasin D induces c-fos gene expression.
The treatment of exponentially growing HeLa cells and quiescent WI-38 cells with cytochalasin D, which disrupts the cytoskeletal microfilaments, results in a rapid and marked increase in the transcription of the c-fos protooncogene with a concomitant increase in c-fos mRNA steady-state levels. Transcription of rRNA, HLA-B7, and H4 histone genes was not significantly affected by the drug treatment. These results suggest that the nucleus can respond to signals related to the structural organization of the cytoskeleton and selectively adjust the regulation of gene expression.
Cytochalasin D↗
Paradoxical movement in Parkinson's disease.
Patients with Parkinson's disease, although impaired, can sometimes move effectively under visual guidance. The stimuli that often elicit such paradoxical movement are similar to those that relay visual information to the cerebellum. We suggest that many instances of paradoxical movement may be explained by the fact that the pathways relaying those visual stimuli can bypass the damaged basal ganglia and allow an intact cerebellar circuit to be used for visuomotor control.
Cerebellum↗
The expression of epidermal growth factor receptor on human bladder cancer: potential use in radioimmunoscintigraphy.
Monoclonal antibody 425, which binds to an extracellular domain of the epidermal growth factor receptor, was used to evaluate the expression of this antigen on bladder cancer cells. Epidermal growth factor receptor was found on all bladder cancer cell lines tested. Immunoperoxidase staining of fourteen invasive human bladder cancers with monoclonal antibody 425 demonstrated that ten showed strong staining, one showed weak staining and three were negative. Five noninvasive tumors were similarly examined. Four of these were negative and one showed weak staining. Biodistribution experiments with human bladder tumor xenografts in athymic nude mice using radiolabeled monoclonal antibody 425 and an isotype matched control antibody demonstrated specific tumor localization at five and seven days following antibody injection. Successful imaging of a human bladder tumor xenograft was achieved five days post antibody injection. These data confirm that epidermal growth factor receptor expression correlates with bladder cancer stage and suggests that epidermal growth factor receptor may serve as a target antigen for radioimmunoscintigraphy.
Animals↗
Inpatients with AIDS and AIDS-related complex: economic inpact on hospitals in North Carolina.
To determine the economic impact of acquired immunodeficiency syndrome (AIDS) or AIDS-related complex (ARC) cases on North Carolina hospitals, we collected inpatient data from all North Carolina hospitals on charges and number of patients discharged with these diagnoses. More than 97% of the state's hospitals responded to the survey for the study year (1987-1988). There were 540 AIDS/ARC discharges from 58 North Carolina general hospitals and 125 AIDS/ARC discharges from 13 other types of hospitals, for a statewide total of 665 patients. The total general hospital charges for AIDS/ARC inpatients in North Carolina were approximately $7.7 million per year, and almost $2 million of these charges were uncompensated by any insurance. The greatest burden of cost for this care was borne disproportionately by 15 of the 58 general hospitals, accounting for 82% of the discharges.
AIDS-Related Complex↗
What children see affects how they read.
Children of mixed abilities were given three single-word lists to read, matched for linguistic complexity. The visual component of the task was made harder by reducing the print size with each new list. The reading errors made by children who did and who did not have a visual impairment were compared. The visually impaired children's pattern of reading errors changed as their vision was stressed by the reduction in print size; their errors became non-words (neologisms). This finding suggests a link between the efficiency of visual processing and the accuracy of reading of these children.
Aptitude↗
Hydrostatic pressure influences histone mRNA.
Exposure of HeLa S3 cells to high hydrostatic pressure (6.89 x 10(3) to 6.89 x 10(4) kPa: 1000 to 10,000 lbfin-2) reduced core and H1 histone mRNA levels as determined by hybridization to specific histone DNA probes. At 4.14 x 10(4) kPa for 10 min core histone and H1 histone mRNA levels were reduced 32-38% and 56%, respectively. At 30 min postdecompression core mRNA levels returned to atmospheric control levels while H1 histone mRNA levels continued to be suppressed. Levels of macromolecular synthesis were monitored under hydrostatic pressure with radioactive precursors of RNA, DNA and protein. Macromolecular synthesis was shown to be suppressed in a dose-dependent manner with increasing magnitude and duration of pressure. To determine the influence of pressure on histone mRNA stability, actinomycin D (10 micrograms ml-1) was used to block RNA synthesis. Relative amounts of H4 and H1 mRNA were determined at atmospheric pressure and following treatment with actinomycin D (10 micrograms ml-1), pressure (4.14 x 10(4) kPa) and a combination of pressure and actinomycin D. This study shows that a synthesis component and a stability component are involved in the pressure-induced reduction of core histone mRNA. At 4.14 x 10(4) kPa for 15 min, there was a 42% reduction in core histone mRNA of which approximately one third was due a suppression of transcription and two thirds to a loss of mRNA stability. The pressure-induced reduction in histone mRNA is attributed to the instability of endogenous histone mRNA and a reduction in transcription/processing of new histone mRNA.
HeLa Cells↗
Proteolytic processing of a plasma membrane-bound precursor to human macrophage colony-stimulating factor (CSF-1) is accelerated by phorbol ester.
A transmembrane precursor to human macrophage colony-stimulating factor (M-CSF, CSF-1) is stably expressed at the cell surface where it is slowly and inefficiently cleaved to yield a soluble form of the growth factor. Incubation in the presence of phorbol ester resulted in rapid cleavage of the plasma membrane-bound precursor and release of soluble CSF-1. Within 60 min after phorbol treatment the quantity of growth factor recovered in the medium was more than 30-fold greater than that observed in the absence of the agent. The growth factor released in the presence of phorbol was biologically active and exhibited the same electrophoretic mobility as that obtained in the absence of the drug. Phorbol ester-accelerated processing of the cell surface CSF-1 precursor was abrogated by long-term exposure to phorbol, but was not inhibited by pretreatment with cycloheximide or incubation in serum-free medium. These results suggest that the enhanced post-translational processing of the CSF-1 precursor resulted from activation of a pre-existing cellular protease via a mechanism involving phorbol ester-mediated stimulation of protein kinase C.
Animals↗
Direct stimulation of cells expressing receptors for macrophage colony-stimulating factor (CSF-1) by a plasma membrane-bound precursor of human CSF-1.
Secreted forms of macrophage colony-stimulating factor (M-CSF or CSF-1) are generated by proteolytic cleavage of membrane-bound glycoprotein precursors. Alternatively spliced transcripts of the human CSF-1 gene encode at least two different transmembrane precursors that are differentially processed in mammalian expression systems. The larger precursor rapidly undergoes proteolysis to yield the secreted growth factor and does not give rise to forms of CSF-1 detected on the cell surface. By contrast, the smaller human CSF-1 precursor is stably expressed on the plasma membrane where it is inefficiently cleaved to release a soluble molecule. To determine whether the smaller precursor is biologically active on the cell surface, mouse NIH-3T3 fibroblasts expressing the different forms of human CSF-1 were killed by chemical fixation and tested for their ability to support the proliferation of cells that require this growth factor. Only fixed cells expressing human CSF-1 precursors on their surface stimulated the growth in vitro of a murine macrophage cell line or normal mouse bone marrow-derived mononuclear phagocytes. The ability of these nonviable fibroblasts to induce the proliferation of CSF-1-dependent cells was not mediated by release of soluble growth factor, required direct contact with the target cells, and was blocked by neutralizing antiserum to CSF-1. These results demonstrate that the cell surface form of the human CSF-1 precursor is biologically active and indicate that plasma membrane-bound growth factors can functionally interact with receptor-bearing targets by direct cell-cell contact.
Animals↗
Relativistic Fermi-Segre formula.
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Journal Article↗
Lorentz-force independence of resistance tails in magnetic fields near Tc for the low-temperature superconductor granular NbN: A Josephson-junction model.
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Journal Article↗
"Quantum" chaos in billiards studied by microwave absorption.
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Journal Article↗
Multiple types of mRNA-cytoskeleton interactions.
Nearly all actively translated mRNAs are associated with the cytoskeleton in HeLa cells and the nature of this association is poorly understood. To gain insight into this association, we have examined and compared the cytoskeleton-mRNA interactions of a signal peptide-histone fusion mRNA (membrane-bound polysomal mRNA) to those of endogenous histone mRNA (nonmembrane-bound polysomal mRNA). We report here the detection of a cytoskeleton attachment site within the signal peptide-histone fusion mRNP/mRNA nucleotide sequence that is not present in wild-type histone mRNA or in HLA-B7 and chorionic gonadotropin-alpha membrane-bound polysomal mRNAs. These results support the possibility that there are multiple mechanisms for the attachment of specific classes of mRNAs to the cytoskeleton.
Base Sequence↗
Role of messenger RNA subcellular localization in the posttranscriptional regulation of human histone gene expression.
Histone mRNAs are naturally localized on non-membrane-bound polysomes and selectively destabilized during inhibition of DNA replication. Targeting histone mRNA to membrane-bound polysomes, by incorporating sequences coding for a signal peptide into the message, results in the stabilization of the histone fusion mRNA when DNA synthesis is interrupted (Zambetti et al.: Proceedings of the National Academy of Sciences of the United States of America 84:2683-2687, 1987). A single nucleotide substitution that abolishes the synthesis of the signal peptide results in the localization of the histone fusion mRNA on non-membrane-bound polysomes to the same extent as endogenous histone mRNA and fully restores the coupling of histone fusion mRNA stability to DNA replication. Signal peptide-histone fusion mRNAs containing two point mutations that result in the incorporation of two positively charged amino acids into the hydrophobic domain of the signal peptide are partially retained on non-membrane-bound polysomes and are partially destabilized during inhibition of DNA synthesis. These data indicate that the degree to which the signal peptide-histone fusion mRNAs are associated with non-membrane-bound polysomes is correlated with the extent to which the mRNAs are degraded during inhibition of DNA synthesis. These results suggest that the subcellular location of histone mRNA plays an important role in the posttranscriptional regulation of histone gene expression.
Amino Acid Sequence↗
MRI of postamputation neuromas.
Magnetic resonance imaging of 24 symptomatic lower limb amputations revealed that postamputation neuromas were easily diagnosed in above-the-knee amputees. Visualization of nerve trunks in below-the-knee amputees was difficult due to greater compactness of calf muscles. Neuromas on magnetic resonance imaging appeared ovoid or rounded and were usually heterogenous and isointense with muscle. Magnetic resonance imaging also showed additional causes of stump pain such as scar formation, fat in atrophied muscles, soft tissue abscesses, osteomyelitis, and hematomas.
Adult↗
Differential association of membrane-bound and non-membrane-bound polysomes with the cytoskeleton.
We report here a differential release of specific mRNAs from the cytoskeleton by cytochalasin D treatment. Non-membrane-bound polysomal mRNAs, such as histone mRNA and c-fos mRNA, are readily released from the cytoskeleton of HeLa cells during cytochalasin D treatment. Over 90% of H3 and H4 histone mRNA is associated with the cytoskeleton in control cells and only 25% in cells treated with cytochalasin D (40 micrograms/ml). In contrast, the membrane-bound polysomal mRNAs for HLA-B7 and chorionic gonadotropin-alpha are inefficiently released from the cytoskeletal framework by cytochalasin D alone; approximately 98% of the HLA-B7 mRNA in control cells is associated with the cytoskeleton, whereas approximately 65% of the HLA-B7 mRNA is retained on the cytoskeleton in cells treated with cytochalasin D (40 micrograms/ml). Disruption of polysome structure with puromycin during cytochalasin D treatment results in the efficient release of HLA-B7 mRNA from the cytoskeleton. Under these conditions, only 25% of the HLA-B7 mRNA remains associated with the cytoskeletal framework. Thus, membrane-bound polysomes appear to be attached to the cytoskeleton through a cytochalasin D-sensitive site as well as through association with the nascent polypeptide and/or ribosome. These results demonstrate a complex association of polysomes with the cytoskeleton and elements of the endoplasmic reticulum.
Actin Cytoskeleton↗
Adherence among children and adolescents with insulin-dependent diabetes mellitus over a four-year longitudinal follow-up: I. The influence of patient coping and adjustment.
An onset cohort of adolescents and children with insulin-dependent diabetes mellitus was studied over a 4-year period. Individual patient psychosocial and demographic factors were assessed at study inception and used to examine aspects of adherence over the follow-up. We found that initial assessment of patient coping (defense level, adaptive strength, and locus of control) and adjustment at study inception were predictive of the level of patient adherence to diabetic regimen over the 4 years of study. Psychosocial variables predicted adherence outcomes independent of patient age. This was found for three domains of adherence, i.e., diet, insulin adjustment, and metabolic monitoring, and for the composite index derived from the separate adherence scales. Preadolescents (ages 9-12) at study entry were more adherent than patients who were already adolescent (ages 13-16) when diagnosed. Using multiple regression, three factors (age, adjustment, ego defense level) accounted for 47% of the variance in adherence. No factors were predictive of change in adherence during the follow-up. Thus, psychosocial characteristics of diabetic children assessed shortly after diagnosis predicted typical or average adherence over a 4-year period. Identification of such characteristics may be useful in developing strategies for intervention early in the course of illness.
Adaptation, Psychological↗