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Biomedical subjects

D Anderson

Publications and source records attributed to D Anderson.

At least 361 records · Page 20Linked to original sources
PubMed1992

Childhood psychological trauma correlates with unsuccessful lumbar spine surgery.

In a retrospective study of 86 patients who underwent lumbar spine surgery, patients who had three or more of a possible five serious childhood psychological traumas (risk factors) had an 85% likelihood of an unsuccessful surgical outcome. Conversely, in patients with a poor surgical outcome, the incidence of these traumas was 75%. In the group of 19 patients with no risk factors, there was only a 5% incidence of failure. This study shows that a highly significant correlation exists between unsuccessful lumbar spine surgery and a history of childhood traumas. Although recognition of predictors for unsuccessful outcome can be useful in avoiding surgery in patients whose indications for surgery are borderline, the greater challenge is to help the patient who, despite being at high psychological risk for negative outcome, has severe spinal pathology that will likely require surgery. In such cases, psychiatric treatment is critical. In the group of 19 patients with no risk factors, single-level laminectomies and discectomies were performed on 6 patients. The other 13 cases were complex, involving a combination of repeat surgeries (n = 4) fusions (n = 3), and/or multilevel laminectomies and discectomies (n = 11).

Adult↗
PubMed1992

Multiple SH2-mediated interactions in v-src-transformed cells.

The Src homology 2 (SH2) domain is a noncatalytic region which is conserved among a number of signaling and transforming proteins, including cytoplasmic protein-tyrosine kinases and Ras GTPase-activating protein (GAP). Genetic and biochemical data indicate that the SH2 domain of the p60v-src (v-Src) protein-tyrosine kinase is required for full v-src transforming activity and may direct the association of v-Src with specific tyrosine-phosphorylated proteins. To test the ability of the v-Src SH2 domain to mediate protein-protein interactions, v-Src polypeptides were expressed as fusion proteins in Escherichia coli. The bacterial v-Src SH2 domain bound a series of tyrosine-phosphorylated proteins in a lysate of v-src-transformed Rat-2 cells, including prominent species of 130 and 62 kDa (p130 and p62). The p130 and p62 tyrosine-phosphorylated proteins that complexed v-Src SH2 in vitro also associated with v-Src in v-src-transformed Rat-2 cells; this in vivo binding was dependent on the v-Src SH2 domain. In addition to binding soluble p62 and p130, the SH2 domains of v-Src, GAP, and v-Crk directly recognized these phosphotyrosine-containing proteins which had been previously denatured and immobilized on a filter. In addition, the SH2 domains of GAP and v-Crk bound to the GAP-associated protein p190 immobilized on a nitrocellulose membrane. These results show that SH2 domains bind directly to tyrosine-phosphorylated proteins and that the Src SH2 domain can bind phosphorylated targets of the v-Src kinase domain.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

SH2 domains of the p85 alpha subunit of phosphatidylinositol 3-kinase regulate binding to growth factor receptors.

The binding of cytoplasmic signaling proteins such as phospholipase C-gamma 1 and Ras GTPase-activating protein to autophosphorylated growth factor receptors is directed by their noncatalytic Src homology region 2 (SH2) domains. The p85 alpha regulatory subunit of phosphatidylinositol (PI) 3-kinase, which associates with several receptor protein-tyrosine kinases, also contains two SH2 domains. Both p85 alpha SH2 domains, when expressed individually as fusion proteins in bacteria, bound stably to the activated beta receptor for platelet-derived growth factor (PDGF). Complex formation required PDGF stimulation and was dependent on receptor tyrosine kinase activity. The bacterial p85 alpha SH2 domains recognized activated beta PDGF receptor which had been immobilized on a filter, indicating that SH2 domains contact autophosphorylated receptors directly. Several receptor tyrosine kinases within the PDGF receptor subfamily, including the colony-stimulating factor 1 receptor and the Steel factor receptor (Kit), also associate with PI 3-kinase in vivo. Bacterially expressed SH2 domains derived from the p85 alpha subunit of PI 3-kinase bound in vitro to the activated colony-stimulating factor 1 receptor and to Kit. We infer that the SH2 domains of p85 alpha bind to high-affinity sites on these receptors, whose creation is dependent on receptor autophosphorylation. The SH2 domains of p85 are therefore primarily responsible for the binding of PI 3-kinase to activated growth factor receptors.

Animals↗
PubMed1992

Cognitive-behavioural treatment of panic disorder during pregnancy and lactation.

The treatment of panic disorder during pregnancy and lactation poses special problems. It is important that both the practitioner and patient consider a number of issues to find the most appropriate treatment for the patient. New cognitive-behavioural treatment options often circumvent the problems of pharmacotherapy for pregnant or lactating women while providing therapeutic benefits which are at least equivalent.

Adult↗
PubMed1992

Retained fetal scalp monitoring lead discovered in the wall of the jejunum.

The retention of a foreign body following surgery is a longstanding and dreaded problem. We report the retention of a fetal scalp monitoring lead that was embedded in the wall of the patient's jejunum and discovered 2 years after cesarean section. In reviewing the American medical literature, we believe this case is, perhaps, unique. The treatment of this entity is discussed as well as ways to help to prevent it.

Adult↗
PubMed1992

A comparison of smokers and nonsmokers with respect to oncogene products and cytogenetic parameters.

Human monitoring studies can be valuable tools for assessing the adverse effects of chemicals. Cytogenetic parameters have been frequently employed but are rarely related directly to possible adverse health effects. Recently, the measurement of oncoprotein levels in plasma has been proposed as a possible and more appropriate indicator of exposure and carcinogenic risk but, unlike chromosome damage, little is known about the effects of possible confounding factors. This study compared the effect of smoking on chromosome aberrations, sister chromatid exchange, and plasma ras oncoprotein levels, in forty humans not otherwise known to be exposed to any specific chemical hazard. No effect was found on any of these end points, with the exception of a moderate, statistically nonsignificant elevation of sister chromatid exchange levels. It is concluded that smoking is unlikely to be a confounding factor in human monitoring studies using oncoprotein levels as an end point.

Chromosome Aberrations↗
PubMed1992

The Kessel prosthesis in total shoulder arthroplasty. A five-year experience.

Between 1982 and 1985, 23 Kessel total shoulder arthroplasties were performed on 22 patients. A clinical and roentgenographic review was performed by an independent observer. Three patients had their prostheses removed and three had revision surgery, leaving 17 shoulders in 16 patients available for study, all with rheumatoid arthritis (RA). All patients were relieved of pain and noticed a general improvement in activities of daily living. Passive flexion and rotation were increased, but active movements remained unchanged. Roentgenographically, radiolucent zones developed around the scapular component on all patients within one year but only around one of the humeral components. Total shoulder arthroplasties with the Kessel prosthesis in RA relieved pain and improved shoulder and arm function. The long-term results were complicated by a high incidence of loosening of the glenoid component, probably a feature of the constrained design of the Kessel prosthesis.

Adult↗
PubMed1992

A comparison of HIV-1 antibody classes, titers, and specificities in paired semen and blood samples from HIV-1 seropositive men.

Twenty-eight paired blood and semen samples obtained from human immunodeficiency virus type 1 (HIV-1) seropositive men at various stages of disease progression were evaluated for titer and immunoglobulin (Ig) class by an enzyme-linked immunosorbent assay (ELISA). Blood antibody titers ranged from 40,000 to 4,000,000 with a median of 40,000. Semen titers ranged from 400 to 40,000 with a median of 400. HIV-1 antibody titers in matched semen and blood samples showed a strong positive correlation (r = 0.963). The ratio of semen:blood titers ranged from 1:1000 to 1:10 with a median of 1:100. There was no correlation between blood or semen antibody titer and stage of disease of the patients. However, there was a trend toward higher (greater than or equal to 4000) semen antibody titers in men with evidence of genital tract inflammation greater than 10(6) white blood cells/ml semen; 3/5 versus 5/23, p greater than 0.1 Fisher exact test). All HIV-1 antibodies detected were of the IgG class; no IgA or IgM class antibodies of titers greater than or equal to 40 were found in either blood or semen. Thirteen paired blood and semen samples from individual patients were analyzed for antibody specificity by Western blot. In some cases antibody profiles in semen were different from those in blood; strong antibody reactivity against the gp160 viral coat antigen band was consistently detected in semen and blood, whereas the prevalence of detectable antibody reactivity against the p55 and p17 HIV-1 antigen bands was significantly reduced in semen.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibody Specificity↗
PubMed1991

Characterization of the human liver vasopressin receptor. Profound differences between human and rat vasopressin-receptor-mediated responses suggest only a minor role for vasopressin in regulating human hepatic function.

The [Arg8]vasopressin (AVP) receptor expressed by human hepatocytes was characterized, and compared with the rat hepatic V1a vasopressin receptor subtype. In addition to determining the pharmacological profile of the human receptor, the cellular responses to AVP were measured in human and rat hepatocytes by assaying glycogen phosphorylase alpha activity and DNA synthesis. Marked differences were observed between human and rat hepatocytes regarding vasopressin receptors and the intracellular consequences of stimulation by AVP. Data presented in this paper demonstrate the following, (i) Vasopressin V1a receptors are present in low abundance on human hepatocytes. (ii) Species differences exist between human and rat V1a receptors with respect to the affinity of some selective antagonists. (iii) AVP-stimulated glycogen phosphorylase a activation in human hepatocytes was approx. 5% of that observed in rat cells. (iv) In contrast with rat hepatocytes, DNA synthesis in human cells in culture was not stimulated by AVP. It is concluded that vasopressin plays only a minor role in the regulation of human hepatic function. Furthermore, conclusions drawn from observations made with AVP and its analogues on rat hepatic function cannot be directly extrapolated to the human situation.

Animals↗
PubMed1991

Effect of murine mast cell growth factor (c-kit proto-oncogene ligand) on colony formation by human marrow hematopoietic progenitor cells.

Purified natural (n) and recombinant (r) murine (mu) mast cell growth factor (MGF, a c-kit ligand) were evaluated alone and in combination with r human (hu) erythropoietin (Epo), rhu granulocyte-macrophage colony-stimulating factor (rhuGM-CSF), rhuG-CSF, and/or rhuM-CSF for effects in vitro on colony formation by multipotential (colony-forming unit-granulocyte, erythroid, monocyte, megakaryocyte [CFU-GEMM]), erythroid (burst-forming unit erythroid [BFU-E]) and granulocyte-macrophage (CFU-GM) progenitor cells from normal human bone marrow. MGF was a potent enhancing cytokine for Epo-dependent CFU-GEMM and BFU-E colony formation, stimulating more colonies and of a larger size than either rhu interleukin-3 (rhuIL-3) or rhuGM-CSF. MGF, especially at lower concentrations, also acted with rhuIL-3 or rhuGM-CSF to enhance Epo-dependent CFU-GEMM and BFU-E colony formation. MGF had little stimulating activity for CFU-GM colonies by itself, but in combination with suboptimal to optimal amounts of rhuGM-CSF enhanced the numbers and the size of CFU-GM colonies in an additive to greater than additive manner. While we did not detect an effect of MGF on CFU-G colony numbers stimulated by maximal concentrations of rhuG-CSF, MGF did enhance the size of CFU-G-derived colonies. MGF did not enhance the activity of rhuM-CSF. In a comparative assay, maximal concentrations of rmu and rhuMGF were equally effective in the enhancement of human bone marrow colony formation, but rhuMGF, in contrast to rmuMGF, did not at the concentrations tested enhance colony formation by mouse bone marrow cells. MGF effects on BFU-E, CFU-GM, and CFU-GEMM may be direct acting ones as MGF-enhanced colony formation by these cells in highly enriched progenitor cell populations of CD34 HLA-DR+ and CD34 HLA-DR+CD33- sorted cells in which greater than or equal to 1 of 2 cells was a BFU-E plus CFU-GM plus CFU-GEMM. MGF appears to be an early acting cytokine that preferentially stimulates the growth of immature hematopoietic progenitor cells.

Antigens, CD34↗
PubMed1991

SH2 and SH3 domains: elements that control interactions of cytoplasmic signaling proteins.

Src homology (SH) regions 2 and 3 are noncatalytic domains that are conserved among a series of cytoplasmic signaling proteins regulated by receptor protein-tyrosine kinases, including phospholipase C-gamma, Ras GTPase (guanosine triphosphatase)-activating protein, and Src-like tyrosine kinases. The SH2 domains of these signaling proteins bind tyrosine phosphorylated polypeptides, implicated in normal signaling and cellular transformation. Tyrosine phosphorylation acts as a switch to induce the binding of SH2 domains, thereby mediating the formation of heteromeric protein complexes at or near the plasma membrane. The formation of these complexes is likely to control the activation of signal transduction pathways by tyrosine kinases. The SH3 domain is a distinct motif that, together with SH2, may modulate interactions with the cytoskeleton and membrane. Some signaling and transforming proteins contain SH2 and SH3 domains unattached to any known catalytic element. These noncatalytic proteins may serve as adaptors to link tyrosine kinases to specific target proteins. These observations suggest that SH2 and SH3 domains participate in the control of intracellular responses to growth factor stimulation.

Amino Acid Sequence↗
PubMed1991

A factor analysis of the DSM-III post-traumatic stress disorder criteria.

The authors factor analyzed DSM-III-based post-traumatic stress disorder symptom ratings made on 131 Vietnam-veteran PTSD patients. Five factors--termed Intrusive Thoughts and Their Effects, Increased Arousal, Impoverished Relationships, Guilt, and Cognitive Interference--emerged. The factor structure gave more support to Laufer, Brett and Gallops' conceptualization of PTSD than to the Horowitz, DSM-III, or DSM-III-R systems. It also generated suggestions for future editions of the diagnostic manual.

Adult↗
PubMed1991

Effects of leukemia inhibitory factor (LIF) on gene transfer efficiency into murine hematolymphoid progenitors.

We have investigated the effects of the cytokine leukemia inhibitory factor (LIF) on recovery and retroviral infection of murine hematopoietic stem cells maintained in short-term culture. Up to a two-fold increase in CFU-S13 recovery was observed, from 9.7 x 10(-5) cells in untreated controls to 17.6 x 10(-5) cells when 10U/ml LIF is added to the culture medium. Intermediate concentrations of LIF (.1U/ml and 1U/ml) were not significantly different from the control. Histological analysis of spleen colonies harvested thirteen days posttransplant demonstrated that LIF does not cause a detectable alteration in the differentiative potential of CFU-S13. The efficiency of retroviral-vector infection in CFU-S13 is also improved, from 15% (24/158) in untreated controls to 91% (116/127) at a LIF concentration of 10U/ml. LIF concentrations of .1U/ml and 1U/ml increased infection efficiency to 35% (14/40) and 71% (37/51), respectively. Analysis of proviral insertion sites in spleen colonies indicated that some CFU-S13 precursors were infected in the LIF-treated marrows, but no identical pairs were detected in the controls. Finally, long-term expression of provirally-encoded human adenosine deaminase (hADA) was measured in hematopoietic tissues of bone marrow transplant recipients six months posttransplant. In all tissues analyzed (spleen, thymus, bone marrow, splenic B cells, peritoneal macrophages, and blood) differentiated progeny of LIF-treated marrows had higher levels of hADA than untreated controls. Tenfold increases in levels of hADA are detected in some tissues, but levels were variable. These experiments demonstrate that LIF directly or indirectly enhances retroviral infection efficiency of hematopoietic stem cells, and might be used to improved existing gene transfer protocols.

Adenosine Deaminase↗
PubMed1991

Regulation of the phage phi 29 prohead shape and size by the portal vertex.

Bacteriophage phi 29 of Bacillus subtilis packages its double-stranded DNA into a preformed prohead during morphogenesis. The prohead is composed of the scaffold protein gp7, the capsid protein pg8, the portal protein gp10, and the dispensable head fiber protein gp8.5. Our objective was to elucidate the phi 29 prohead assembly pathway and to define the factors that determine prohead shape and size. The structural genes of the phi 29 prohead were cloned and expressed in Escherichia coli individually or in combination to study form determination. The scaffold protein was purified from E. coli as a soluble monomer. In vivo and in vitro studies showed that the scaffolding protein interacted with both the portal vertex and capsid proteins. When the scaffold protein interacted only with the capsid protein in vivo, particles were formed with variable size and shape. However, in the presence of the portal vertex protein, particles with uniform size and shape were produced in vivo. SDS-PAGE analysis showed that the latter particles contained the proteins of the scaffold, capsid, head fiber, and portal vertex. These results suggest that the scaffolding protein serves as the linkage between the portal vertex and the capsid proteins, and that the portal vertex plays a crucial role in regulating the size and shape of the prohead.

Bacillus subtilis↗
PubMed1991

sRNA of phage phi 29 of Bacillus subtilis mediates DNA packaging of phi 29 proheads assembled in Escherichia coli.

The structural genes of the prohead of phage phi 29 of Bacillus subtilis and a small phi 29 RNA (sRNA) were cloned and expressed in Escherichia coli individually or in combination to study the role of the sRNA in prohead assembly and the mechanism of prohead morphogenesis. The genes coding for the proteins of the scaffold (gp7), the capsid (gp8), the portal vertex (gp10), and the dispensable head fiber (gp8.5) were expressed in E. coli and the gene products were assembled, with and without the presence of the sRNA, into uniform and prolate particles that resembled the typical native phi 29 prohead. No differences in particle size and shape were found between the particles of 7-8-8.5-10 (scaffold-capsid-fiber-portal vertex) and 7-8-8.5-10-RNA (scaffold-capsid-fiber-portal vertex-RNA), suggesting that the phi 29 sRNA was not required for phi 29 prohead assembly. The 7-8-8.5-10 particles produced in E. coli in the absence of phi 29 sRNA were fully competent to package phi 29 DNA in the defined in vitro DNA packaging system by the addition of purified sRNA. Moreover, these DNA-filled heads were assembled into infectious virions in extracts. Without the addition of the sRNA, the 7-8-8.5-10 particles were incompetent while the 7-8-8.5-10-RNA particles were competent in DNA packaging. Bacterial sRNA present in E. coli cannot substitute for the phi 29 sRNA. The assembly of prohead particles in E. coli indicated that host factors unique to B. subtilis were not required. The evidence that the phi 29 sRNA was not required for phi 29 prohead assembly and was not a fixed structural component of the phi 29 prohead favors the conclusion that the phi 29 sRNA is a specific enzyme or morphogenetic factor in DNA packaging.

Bacillus subtilis↗