Search PubMed⌕ Search

Biomedical subjects

R J Thompson

Publications and source records attributed to R J Thompson.

At least 109 records · Page 6Linked to original sources
PubMed1989

Extracellular matrix proteoglycan degradation by human alveolar macrophages and neutrophils.

Degradation and restructuring of the elastin fiber network of the lung is a pivotal process in the pathogenesis of emphysema. Alveolar macrophages and neutrophils are probably directly involved in elastin degradation, but they may also indirectly influence elastin structure and function by altering other extracellular matrix components such as proteoglycans. In this study the mechanisms of proteoglycan degradation by human alveolar macrophages and neutrophils have been explored. Macrophages appear to utilize plasminogen in solubilizing 35SO4-labeled proteoglycans in extracellular matrix produced by neonatal rat vascular smooth muscle cells. Proteoglycan degradation by macrophages is significantly augmented in the presence of 1% human serum. In contrast, neutrophils apparently utilize intrinsic proteinases to solubilize extracellular matrix proteoglycans, and serum inhibits proteoglycan degradation by these cells. Persistent inflammation in the terminal airways of cigarette smokers may produce proteoglycan degradation and influence elastin fiber architecture where the earliest physiological and anatomic evidence of emphysema appears.

Animals↗
PubMed1989

No flow or low flow? A study of the ischemic marker creatine kinase BB after deep hypothermic procedures.

Twenty-seven children with complex congenital heart malformations necessitating early repair were studied before and after deep hypothermic procedures. The children were allocated into two groups. One group underwent total circulatory arrest (40 +/- 6 minutes). In the other group perfusion was maintained during deep hypothermia but reduced a 25% of normal at normothermia. The temperature was reduced to 15 degrees C (nasopharynx) in both groups with a combination of topical and core cooling. To study cerebral injury, were made serial measurements of creatine kinase isoenzyme BB from arterial samples before and for 8 hours after the deep hypothermic procedure. Creatine kinase isoenzyme BB increased after both procedures from 4.3 +/- 0.9 ng/ml to 10.4 +/- 1.8 ng/ml in the circulatory arrest group and from 2.8 +/- 0.7 ng/ml to 9.9 +/- 1.9 ng/ml in the low-flow group (no significant difference). The results were analyzed in relation to age, size, study group, hemoglobin, blood glucose, and blood gases. The creatine kinase BB levels were positively related to preoperative hemoglobin and blood glucose values before the hypothermic procedures.

Blood Glucose↗
PubMed1989

The role of central nervous system functioning and family functioning in behavioral problems of children with myelodysplasia.

This study examined the frequency and type of behavioral problems in 50 children with myelodysplasia and investigated the hypothesized roles of central nervous system (CNS) functioning and family functioning in behavioral problem outcome. The findings revealed that 50% of the children with myelodysplasia had a behavioral problem pattern and another 2% had low social skills, yielding an overall problem pattern rate of 52%. There was a high frequency of internalizing behavior problem profiles and a very low frequency of externalizing behavior problem profiles. Although there was little support for the hypothesized mediating role of central nervous system functioning, considerable support was provided for the association of family functioning and behavior problem outcomes.

Adolescent↗
PubMed1989

Elective deep hypothermia with total circulatory arrest: changes in plasma creatine kinase BB, blood glucose, and clinical variables.

Serial measurements of a marker of brain ischemia, creatine kinase isoenzyme BB, were performed in arterial and internal jugular venous blood from 20 infants younger than 1 year of age before and during the first 20 hours after deep hypothermic total circulatory arrest procedures. A two-site monoclonal method was used, and the results were analyzed in relation to age, size, type of cardiac lesion, hemoglobin level, blood glucose level, pH, and duration of the total circulatory arrest. The creatine kinase BB concentrations increased after the arrest, more so in venous than in arterial blood, from 3.2 +/- 0.5 ng/ml to 17.5 +/- 4.5 in arterial blood and from 3.5 +/- 0.5 ng/ml to 18.1 +/- 5.8 in venous blood. Arterial-venous concentration differences correlated with venous concentrations (r = 0.92, p less than 0.01). The duration of the arrest correlated with creatine kinase BB concentrations during reperfusion with correlation coefficients between 0.50 to 0.90 depending of what sequence of the 20-hour sampling period was analyzed. The best correlation was obtained during the first 4 hours of reperfusion. Age, size of the child, and preoperative cyanosis correlated with postoperative creatine kinase BB but were less important than the arrest time, blood glucose level (r = 0.62, p less than 0.01), pH (r = -0.78, p less than 0.01), and hemoglobin level (r = 0.76, p less than 0.01) during reperfusion. It is suggested that a different control of blood glucose level and pH during reperfusion may be of importance to reduce biochemical signs of cerebral dysfunction after deep hypothermic total circulatory arrest procedures.

Blood Glucose↗
PubMed1988

Integration host factor (IHF) represses a Chlamydomonas chloroplast promoter in E. coli.

We show that in E. coli, a Chlamydomonas chloroplast promoter, PA, is repressed by Integration Host Factor (IHF). The himA 42 mutation, altering the alpha-subunit of E. coli IHF, leads to over-accumulation of PA transcripts in vivo. This effect requires upstream chloroplast DNA sequences. DNAase I and methylation protection experiments show that IHF binds in vitro to a site within PA and band-retardation shows that IHF inhibits formation of PA-E. coli RNA polymerase open complexes. We interpret these results, together with our previous deletion analyses, to mean that in E. coli, repression of PA by IHF minimally requires both binding of IHF to a site overlapping PA and binding of one or more additional proteins, perhaps including IHF itself, to sequences upstream of PA.

Bacterial Proteins↗
PubMed1988

Expression of the 2',3'-cyclic nucleotide 3'-phosphohydrolase gene and immunoreactive protein in oligodendrocytes as revealed by in situ hybridization and immunofluorescence.

In order to investigate the role of the myelin-associated enzyme 2' 3'-cyclic nucleotide 3'-phosphohydrolase in the development of the myelin sheath, as well as genetic factors involving dysmyelinating disorders, we have recently isolated and sequenced cDNAs corresponding to the CNPase protein. In this study we have used 32P-labeled bovine CNPase cDNA probes to localize the messenger RNA coding for this enzyme in mouse cerebral and cerebellar cryostat sections and have compared our data with the distribution of the CNPase protein as revealed by immunofluorescence. Specific labeling was localized to the white matter fiber tracts and, in many areas, to individual oligodendrocyte cell bodies. The corpus callosum and the white matter of the cerebellum were heavily labeled. Distribution of the CNPase protein, as detected by immunohistochemical studies, was parallel to that of the CNPase mRNA as detected by in situ hybridization histochemistry, with oligodendrocyte cell bodies and their processes intensely labeled. This study provides strong evidence that the CNPase gene is expressed in the myelin-producing cells of the central nervous system and that CNPase is synthesized by and stored within oligodendrocytes.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗
PubMed1988

Sexual abuse in young children: its clinical presentation and characteristic patterns.

A retrospective record survey was performed using all child clients aged less than 7 years seen at a community mental health center during the period 1982-1984. The total number of 202 children fell into three groups: sexually abused (n = 37), physically abused (n = 35), and nonabused clinical children (n = 130). These groups were compared in order to learn more about sexual abuse in young children. Family background of both abused groups were similar to each other but differed from the nonabused group in having more factors related to family stress than the nonabused group. Clinical presentations of all the children overlapped a great deal symptomatically; however, the sexually abused children had a statistically significant higher frequency of inappropriate sexual behavior than the other two groups. Several characteristics of the abusive patterns suffered by the two abuse groups differed at or near statistical significance: sexually abused children were more often victimized in single acts by nonrelated child perpetrators than were physically abused children.

Adaptation, Psychological↗
PubMed1988

The immunolocalization of protein gene product 9.5 using rabbit polyclonal and mouse monoclonal antibodies.

In order to assess the potential of protein gene product (PGP) 9.5 as a marker of the nervous and neuroendocrine systems, we examined its immunolocation in human, rat and guinea-pig tissues, using a rabbit polyclonal antiserum and two new mouse monoclonal antisera, I3C4 and 3IA3. Our results demonstrate immunoreactive PGP 9.5 in neurons and nerve fibres at all levels of the central and peripheral nervous system, in many neuroendocrine cells, in part of the renal tubule, in spermatogonia and Leydig cells of the testis, and in ova and in some cells of the pregnant and non-pregnant corpus luteum. In routinely processed tissues, standard immunohistochemical techniques using the polyclonal antibody demonstrated peripheral nerve fibres of all sizes with striking clarity.

Animals↗
PubMed1987

Sequence conservation in the 3'-untranslated regions of neurone-specific enolase, lymphokine and protooncogene mRNAs.

The C-terminal protein-coding and the entire 3'-untranslated regions of a cDNA corresponding to human neurone-specific enolase mRNA have been sequenced. The 3'-untranslated region is 892 bases long and shows a high degree of homology with the 3'-untranslated region of rat neurone-specific enolase mRNA. This sequence conservation is not seen in non-neuronal enolase mRNAs. Features of the conserved sequence include an A-rich region approx. 250 bases from the stop codon at a point corresponding to the polyadenylation signal site in non-neuronal enolase mRNA, and a repeating ATTT sequence. This unusual motif in eukaryotic mRNAs has previously been reported in the 3'-untranslated regions of lymphokine and protooncogene mRNAs.

Amino Acid Sequence↗
PubMed1987

Molecular cloning of the myelin specific enzyme 2',3'-cyclic-nucleotide 3'-phosphohydrolase.

We describe the isolation of cDNA clones for bovine brain 2',3'-cyclic-nucleotide 3'-phosphohydrolase (CNPase, EC 3.1.4.37), the third most abundant protein in central nervous system myelin. The cDNA encodes the complete protein (400 amino acids) and hybridizes to a major size species of mRNA in bovine brain tissue, approx. 2.7 kb in size. CNPase mRNA levels do not appear to be affected in quaking dysmyelinating mutant mice. The sequence reveals probable sites for CNPase phosphorylation by cAMP-dependent protein kinase and a region of homology with haemocyanin.

2',3'-Cyclic Nucleotide 3'-Phosphodiesterase↗
PubMed1987

Stimulation of a Chlamydomonas chloroplast promoter by novobiocin in situ and in E. coli implies regulation by torsional stress in the chloroplast DNA.

We have characterized regulation of a complex Chlamydomonas reinhardtii chloroplast (PA) whose activity is stimulated by the DNA gyrase inhibitor novobiocin, both in the alga itself and in a heterologous Escherichia coli plasmid system. Since novobiocin is known to reduce torsional stress in E. coli DNA, we interpret our results to mean that PA is regulated by torsional stress in the chloroplast DNA. In E. coli, where we could readily manipulate PA, we found that this regulation depends on sequences upstream of PA. These sequences contain at least two different kinds of silencing elements that inhibit PA in the absence of novobiocin. Novobiocin stimulates PA only when the promoter-distal silencing element is present.

Base Sequence↗
PubMed1987

Molecular cloning of cDNA coding for human PGP 9.5 protein. A novel cytoplasmic marker for neurones and neuroendocrine cells.

The co-ordinate sequencing of the human neuronal and neuroendocrine marker protein PGP 9.5 and its cDNA is described. The cDNA encodes the complete protein (212 amino acids), and the 340 nucleotide 3'-noncoding region including the polyadenylation signal, indicating an mRNA slightly larger than 1 kb in size. Protein sequencing of 50% of PGP 9.5 confirms the deduced protein sequence.

Amino Acid Sequence↗
PubMed1987

Vulvar and vaginal hematomas: a retrospective study of conservative versus operative management.

We reviewed 32 cases of vulvar and vaginal hematomas treated at three hospitals in Jacksonville, Florida, from March 1975 to March 1985. Patients ranged in age from 14 to 37 years. In 29 patients the hematomas resulted from obstetric trauma and in three from other causes. We found that patients managed conservatively had more subsequent operative intervention and more complications requiring antibiotics and transfusion, and they required more days of hospitalization than patients managed operatively. We also found an increased risk of complications and increased hospitalization for patients with conservatively managed hematomas when the product of the longitudinal diameter and the transverse diameter was 15 or greater.

Adolescent↗