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J R Day

Publications and source records attributed to J R Day.

At least 37 records · Page 2Linked to original sources
PubMed1995

Functional expression of human and mouse plasma phospholipid transfer protein: effect of recombinant and plasma PLTP on HDL subspecies.

The molecular cloning of mouse plasma phospholipid transfer protein (PLTP) and the eukaryotic cell expression of complementary DNA for mouse and human PLTP are described. Mouse PLTP was found to share 83% amino acid sequence identity with human PLTP. PLTP was produced in baby hamster kidney cells. Conditioned medium from BHK cells expressing PLTP possessed both phospholipid transfer activity and high density lipoprotein (HDL) conversion activity. PLTP mRNA was detected in all 16 human tissues examined by Northern blot analysis with ovary, thymus, and placenta having the highest levels. PLTP mRNA was also examined in eight mouse tissues with the highest PLTP mRNA levels found in the lung, brain, and heart. The effect of purified human plasma-derived PLTP and human recombinant PLTP (rPLTP) on the two human plasma HDL subspecies Lp(A-I) and Lp(A-I/A-II) was evaluated. Plasma PLTP or rPLTP converted the two distinct size subspecies of Lp(A-I) into a larger species, an intermediate species, and a smaller species. Lp(A-I/A-II) particles containing multiple size subspecies were significantly altered by incubation with either plasma or rPLTP with the largest but less prominent subspecies becoming the predominant one, and the smallest subspecies increasing in concentration. Thus, PLTP promoted the conversion of both Lp(A-I) and Lp(A-I/A-II) to populations of larger and smaller particles. Also, both human PLTP and mouse rPLTP were able to convert human or mouse HDL into larger and smaller particles. These observations suggest that PLTP may play a key role in extracellular phospholipid transport and modulation of HDL particles.

Amino Acid Sequence↗
PubMed1995

Organization of human phospholipid transfer protein gene.

We have determined the exon/intron organization of the human phospholipid transfer protein gene. The gene, which spans approximately 13.3 kilobases, is comprised of 16 exons. The organization of the phospholipid transfer protein gene strikingly resembles that encoding another plasma lipid transfer protein, the human cholesterol ester transfer protein. The exon-intron junctions in these two genes are highly conserved, with eight out of fifteen junctions interrupting the same codons, while the remaining junctions lie within 5 residues of each other. The similarity in gene structure and homology in coding sequences suggests that these two genes most likely evolved from a common ancestral gene.

Amino Acid Sequence↗
PubMed1995

Differential regulation of catalytic and non-catalytic trkB messenger RNAs in the rat hippocampus following seizures induced by systemic administration of kainate.

Ribonuclease protection analysis and quantitative in situ hybridization histochemistry were used to investigate the coordination and regional expression of catalytic and non-catalytic trkB messenger RNAs in the adult rat hippocampus following systemic kainate-induced seizures. Changes in trkB expression were compared with the messenger RNA expression of its neurotrophic ligands, brain-derived neurotrophic factor and neurotrophin-3. TrkB messenger RNA expression was increased in the dentate granule cells at 1-4 h following the onset of seizures, and returned to control levels 16-24 h thereafter. In addition, seizures also induced expression of trkB messenger RNA in putative non-neuronal cells at four to seven days in the molecular layer of the dentate gyrus and the stratum lacunosum moleculare of the CA1 region. Hybridization with probes specific for the non-catalytic trkB receptor and the catalytic trkB receptor revealed that the increases at four and seven days in the molecular layers of the hippocampus reflected an up-regulation of only the non-catalytic form of the receptor. Furthermore, the neuronal increases observed 1-4 h were due to an up-regulation of both trkB TK- and trkB TK+ messenger RNAs. It was established that systemic administration of kainate increased brain-derived neurotrophic factor messenger RNA levels in the pyramidal and granule cell regions of the hippocampus 1-4 h following the onset of behaviorally manifested seizure activity. Early changes in neuronal expression of trkB TK- and trkB TK+ messenger RNA paralleled changes in brain-derived neurotrophic factor messenger RNA in the dentate granule cell and CA1 pyramidal cell layers, but not in the CA3 subregion. These data suggest that concomitant regulation of brain-derived neurotrophic factor and its cognate receptor may play a role in the selective vulnerability of hippocampal subregions to kainate-induced neuropathology. Furthermore, these data suggest a dual function for trkB receptor expression in the hippocampus following kainate-induced seizures, possibly related to both the plastic and degenerative consequences of seizure induction by kainate.

Animals↗
PubMed1994

Purification and molecular cloning of human apolipoprotein F.

In our effort to study proteins that are involved in high density lipoprotein metabolism, we have identified apolipoprotein F and isolated a full length cDNA clone. Apolipoprotein F, with an apparent molecular mass of 29 kilodaltons, was purified from human high density lipoproteins using a modified two dimensional electrophoresis procedure. The cDNA, with a size of 1735 base pairs, was cloned from a Hep G2 cDNA library. The cDNA encodes apolipoprotein F, which is composed of 162 amino acids, and predicts that apolipoprotein F is a proteolytic product of a larger protein. Northern blot analysis indicates that apolipoprotein F mRNA is detected only in liver for the tissues examined. The gene was mapped to human chromosome number 12 using a human/rodent somatic cell hybrid mapping panel.

Amino Acid Sequence↗
PubMed1994

Complete cDNA encoding human phospholipid transfer protein from human endothelial cells.

Phospholipid transfer protein, with an apparent molecular mass of 81 kDa, was purified from human plasma. The NH2-terminal amino acid sequence of a 51-kDa proteolytic fragment obtained from phospholipid transfer protein allowed degenerate primers to be designed for polymerase chain reaction and the eventual isolation of a full-length cDNA from a human endothelial cDNA library. The cDNA is 1,750 base pairs in length and contains an open reading frame of 1,518 nucleotides encoding a leader of 17 amino acids and a mature protein of 476 residues. Northern blot analysis shows a single mRNA transcript of approximately 1.8 kilobases with a wide tissue distribution. The gene was mapped to chromosome 20 using a human/rodent somatic cell hybrid mapping panel. Phospholipid transfer protein was found to be homologous to human cholesteryl ester transfer protein, human lipopolysaccharide-binding protein, and human neutrophil bactericidal permeability increasing protein (20, 24, and 26% identity, respectively).

Amino Acid Sequence↗
PubMed1994

Transcriptional control of glial fibrillary acidic protein and glutamine synthetase in vivo shows opposite responses to corticosterone in the hippocampus.

Transcriptional regulation of two astrocyte genes, glial fibrillary acidic protein (GFAP) and glutamine synthase (GS), by glucocorticoids was determined by nuclear run-on assay with hippocampal tissues from adult male F344 rats. Transcriptional responses of GFAP to corticosterone were slower than those observed for GS, but were more sensitive to changes in plasma corticosterone. The transcription of GFAP did not change 2 h after the injection of 10 mg corticosterone, but was reduced by 50% at 6 and 24 h. In contrast, corticosterone increased GS transcription at 2 and 6 h. Seven days after adrenalectomy, GFAP, but not GS, transcription was increased. Corticosterone replacement (200 micrograms/ml in the drinking water) suppressed GFAP, but did not increase GS transcription in adrenalectomized rats. Therefore, GFAP transcription is more sensitive to low physiological levels of corticosterone than transcription of GS. The slower response of GFAP than GS to corticosterone suggests that glucocorticoids may have indirect effects on GFAP expression that require additional transcriptional regulators besides the glucocorticoid receptor.

Adrenalectomy↗
PubMed1993

Gonadal steroids regulate the expression of glial fibrillary acidic protein in the adult male rat hippocampus.

This study demonstrates that gonadal steroids (estradiol, testosterone, dihydrotestosterone) can regulate the expression of glial fibrillary acidic protein in the adult male rat brain. Previously, we showed that castration of adult male rats increased glial fibrillary acidic protein messenger RNA in the hippocampus and that this increase was additive with the increase induced by deafferenting entorhinal cortex lesions [Day et al. (1990) Molec. Endocr. 4, 1995-2002 . We extended these effects of castration and entorhinal cortex lesion to glial fibrillary acidic protein, using immunoassays. Furthermore, we found regional differences in responses to castration and inhibited by sex steroids. In contrast, hypothalamic glial fibrillary acidic protein expression was inhibited by castration. Similar regional differences were also shown for astrocyte glial fibrillary acidic protein distribution by immunocytochemistry. The regional specificity of glial fibrillary acidic protein expression after castration and sex steroid replacement is pertinent to the role of astrocytes in synaptic plasticity in unlesioned adults as well as in responses to lesions where the steroid milieu has been shown to influence sprouting.

Animals↗
PubMed1993

Induction of noncatalytic TrkB neurotrophin receptors during axonal sprouting in the adult hippocampus.

Brain-derived neurotrophic factor (BDNF) and its signal transducing receptor, the TrkB tyrosine protein kinase, are expressed at high levels in the hippocampus of the adult brain, suggesting a role for BDNF mechanisms in neuronal plasticity. To test this hypothesis, we used defined lesions of perforant path and fimbria-fornix, two major hippocampal afferents, to remove synapses on dendrites of dentate gyrus granule cells and pyramidal cells of Ammon's horn and induce synaptic rearrangements. These combined lesions remove afferent connections from entorhinal cortex and septum and produce massive sprouting of axons of the commissural/associational pathways into the molecular layer of the hippocampal dentate gyrus. At days 1, 3, and 6, the lesions decreased BDNF mRNA expression ipsilaterally to approximately 50% of control, with complete recovery at 14 d. The lesions did not alter trkB mRNA levels in neuronal layers of the hippocampus; however, they resulted in a pronounced induction of trkB mRNA expression in hippocampal non-neuronal cells 6-14 d after lesioning. The induction corresponded in time and place to the synaptic reorganization in the lesioned hippocampus. The mRNA species newly induced by the lesions corresponded to those transcripts encoding the noncatalytic TrkB receptor isoform that lacks the cytoplasmic protein kinase domain. Expression of mRNAs coding for neurotrophin-3 and the TrkC tyrosine protein kinase were not altered by the lesions. The findings suggest that truncated noncatalytic TrkB molecules expressed on the surface of glial cells play an important role in plasticity of the adult brain, possibly regulating the concentration of bioactive neurotrophins or the responsiveness of neurotrophin receptors. Alternatively, they may play a role in presenting neurotrophin molecules to growing axons.

Animals↗
PubMed1992

Molecular cloning and sequence analysis of the cDNA encoding human apolipoprotein H (beta 2-glycoprotein I).

Apolipoprotein H, also known as beta-2-glycoprotein I, was purified from human serum, and antiserum produced to denatured apolipoprotein H detected a cDNA clone from a lambda gt11 library derived from human liver. This cDNA coded for the complete sequence of the mature protein. The cDNA insert, along with a polymerase chain reaction product which extended the 5' end of the message, were subcloned and both strands were sequenced. The apolipoprotein H precursor was found to code for 345 amino acids, 326 of which appear in the mature protein. The deduced amino acid sequence of human apolipoprotein H differs from its rat homologue by the presence of a 48-amino acid stretch which is absent from the rat protein. The remainder of the proteins share a greater than 80% similarity. The amino acid sequence of apolipoprotein H consists largely of repeated units approximately 60 amino acids in length. These repeats are comparable to "sushi structures" found in a large number of diverse proteins, including complement components, receptors and regulators of complement activation, serum proteins, membrane-associated adhesion proteins, and other structural and catalytic proteins. Apolipoprotein H was shown to be transcribed by human hepatoma cell lines Hep 3B and Hep G2, and rat liver by detection of mRNA using northern blot analysis.

Amino Acid Sequence↗
PubMed1992

New mRNA probes for hippocampal responses to entorhinal cortex lesions in the adult male rat: a preliminary report.

Three new mRNA responses were found in the hippocampus of the adult male rat after entorhinal cortex lesions (ECL) that induce synaptic reorganization. Hippocampus cDNA libraries were screened by a subtractive hybridization strategy designed to detect ECL-induced mRNAs. Partial sequencing showed clones with similarities to mouse vimentin, ferritin, and polypeptide 7B-2. A sequence similar to mouse SNAP-25 sequence was also detected. Using a mouse SNAP-25 probe, rat SNAP-25 mRNA increased in the hippocampus after ECL.

Animals↗
PubMed1992

Physician peer review surveys: a management tool for improving quality of patient care.

An increasing number of patients are presenting multiple medical problems requiring the collaboration of two or more physician specialists or subspecialists for effective treatment. The quality of care delivered to multiple-problem patients depends greatly on how well the physician specialists interact with one another. The Cleveland Clinic Foundation (CCF) has developed and implemented a physician peer review survey that enables physicians to receive anonymous feedback on the service they provide to their colleagues. The survey has been implemented in both medical and surgical departments. Colleagues have identified areas for improvement to increase collaboration and enhance effectiveness in treating multiproblem patients. The data have led to a variety of specific service-related improvements and changes in physician behavior. Though originally conceived as a quality improvement technique, the physician review survey has become an internal marketing and management tool for physician managers.

Consumer Behavior↗
PubMed1992

Decortication and striatal mRNA: increases of mRNA for fibronectin, but not of NCAM or alpha-1 tubulin.

Ipsilateral frontal cortex lesions damaged the corticostriatal input. Northern hybridization analysis showed increases in fibronectin (FN) mRNA, but not changes in mRNA for neural cell adhesion molecule (NCAM), neuro-filament-68 (NF-68) or alpha-tubulin (alpha-1T) 72 h post-lesion. In situ hybridization resolved a different spatial-temporal distribution. The superficial cell layer beneath the wound cavity showed transient elevations of FN mRNA that peaked at 72 h post-lesion. However, in the ipsilateral striatum, FN mRNA was maximal at later times than in the wound cavity, at 240 h post-lesion. Changes in NCAM and alpha-tubulin mRNAs in response to decortication occur only around the wound cavity but not in the deafferentated striatum. The different time courses of mRNA revealed by Northern blot analysis and in situ hybridization are most probably due to contamination of the ipsilateral striatum at dissection with superficial tissue adjacent to the wound cavity. These results suggest that cellular responses to ipsilateral decortication consist of two phases: (i) a wound healing process; and (ii) striatal responses to deafferentation.

Animals↗
PubMed1991

Increases in transforming growth factor-beta mRNA in hippocampus during response to entorhinal cortex lesions in intact and adrenalectomized rats.

Transforming growth factor-beta mRNA was detected with a rat TGF-beta 1 coding sequence probe as a 2.5 kb band by RNA blot hybridization of total RNA from the adult male rat hippocampus. Following electrolytic lesions of the entorhinal cortex that cause hippocampal deafferentation and synaptic remodeling, TGF-beta mRNA increases 5-fold in ipsilateral hippocampus when compared with intact controls. This increase was independent of prior adrenalectomy or corticosterone-replacement. These data demonstrate that TGF-beta gene expression increases in response to hippocampal deafferentation.

Adrenal Cortex↗
PubMed1991

Corticosterone differentially regulates the bilateral response of astrocyte mRNAs in the hippocampus to entorhinal cortex lesions in male rats.

This study examined the effect of adrenalectomy (ADX) and corticosterone (CORT) replacement on the levels of two astrocyte mRNAs during responses to unilateral entorhinal cortex lesions (ECL) to identify molecular mechanisms involved in glucocorticoid modulation of astrocyte activation following deafferentation. Both glial fibrillary acidic protein (GFAP) and sulfated glycoprotein-2 (SGP-2) mRNA were increased in the ipsilateral hippocampus 4 days following unilateral ECL. In unlesioned ADX rats CORT replacement decreased both messages in the hippocampus. CORT replacement suppressed the ECL-induced increase of GFAP mRNA in the contralateral, but not ipsilateral hippocampus of ADX rats. In contrast, CORT decreased SGP-2 mRNA both ipsi- and contralaterally. It is clear that several regulatory mechanisms are responsible for maintaining a physiological balance of astrocyte activity in the adult brain, and that changes in circuit integrity and the endocrine milieu can alter this balance.

Adrenalectomy↗
PubMed1991

Plasma patterns of prolactin, progesterone, and estradiol during early pregnancy in aging rats: relation to embryonic development.

Regularly cyclic, middle-aged female rats exhibit a decreased incidence of fertility, and those females that are fertile produce smaller litters. This decreased litter size is directly related to a reduced number of normal blastocysts available for implantation. Recent evidence indicates that embryonic abnormalities in middle-aged rats become apparent as early as Day 2 of pregnancy. Inasmuch as the semicircadian secretion of prolactin (PRL) is essential for the rescue of corpora lutea during early gestation and luteal production of progesterone (P) and estradiol (E2) in sufficient quantities is obligatory for embryonic development and implantation, the present study examined the profiles of plasma PRL, P, and E2 during the first 3 days of pregnancy in both young and middle-aged rats and assessed the embryonic development in these same animals. Regularly cyclic, middle-aged (9-11 mo) and young (4-5 mo) rats were cannulated via the right jugular vein on Diestrus Day 2 and mated with fertile males on proestrus. The next morning, sperm in the vaginal lavage confirmed mating, and that day was designated Day 1 of pregnancy. Beginning at 1400 h on Day 1 and continuing to 2400 h on Day 2, serial blood samples were taken at 2-h intervals for PRL assay. In the first experiment, samples were also collected at 8-h intervals during Days 1-3 for measurement of plasma P.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1991

Overnight assessment of marketing crises.

The Cleveland Clinic Foundation received significant negative publicity in 1987 when a surgical resident was reported to have AIDS. The resulting pressures from senior managers for immediate market information stimulated development of an overnight market research capability through prenegotiated contracts with market research suppliers so that studies could be implemented on short notice. Contracts have been signed with three market research companies and the overnight market research methods have twice been used successfully with only minor modifications.

Acquired Immunodeficiency Syndrome↗