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Biomedical subjects

E Olson

Publications and source records attributed to E Olson.

At least 19 recordsLinked to original sources
PubMed1999

Immunomagnetic recovery of human neutrophil defensins from the human gingival crevice.

The human neutrophilic protein defensins are cationic, antimicrobial, cytotoxic, corticostatic chemotactic, opsonic peptides found in azurophilic granules and constitute about 5% of the total protein in human neutrophils. In the present study, defensins were recovered from the human gingival crevice using paramagnetic microspheres (beads), coated with anti-defensin antibodies. The bead-bound defensins were assayed using an enzyme-linked immunosorbent assay developed in this laboratory. Twenty sites were sampled; defensin was found in 100% of the sites and ranged in amount from 270-2000 ng/site. The large local concentrations of defensins, estimated in the mg/ml range, may have major effects on the microbiology of the gingival crevice.

Adult↗
PubMed1999

Factors that increase the risk of leakage during surgical removal of benign cystic teratomas.

The contents of mature cystic teratomas can be a potent irritant resulting in chemical peritonitis. Using a retrospective cohort, we examined the various risk factors for leakage of benign cystic teratomas during laparoscopy and laparotomy. Cyst leakage of the benign cystic teratoma contents was the primary endpoint. In all, 158 women underwent surgery for a total of 178 ovarian benign cystic teratomas. Statistical analysis was performed using chi(2), Mann-Whitney U and multivariate logistic regression analysis. A total of 115 benign cystic teratomas was successfully removed without intra-operative leakage and 63 underwent intra-operative leakage either at laparoscopy or laparotomy. The likelihood of success of removing the benign cystic teratoma intact was unrelated to age, pre-operative size or surgical technique. There was no difference among cystectomies performed by laparotomy in surgeon experience or the presence of adhesions. However, surgeons with more laparoscopic experience (>35 laparoscopies/year) were less likely to have intra-operative leakage (relative risk: 0.5, 95% confidence interval: 0.2, 1.2) compared to surgeons with less experience (<20/year) at cystectomy (26.1 versus 51.2% respectively). Oophorectomy significantly reduced the frequency of intra-operative leakage at both laparoscopy and laparotomy (14.7%). These findings suggest that laparoscopic experience can reduce the risk of leakage at cystectomy. At laparotomy, lack of surgeon postgraduate years of experience was not a risk factor for leakage.

Cyst Fluid↗
PubMed1998

Broad spectrum antimicrobial biocides target the FabI component of fatty acid synthesis.

The broad spectrum antibacterial properties of 2-hydroxydiphenyl ethers have been appreciated for decades, and their use in consumer products is rapidly increasing. We identify the enoyl-acyl carrier protein reductase (fabI) component of the type II fatty acid synthase system as the specific cellular target for these antibacterials. Biologically active 2-hydroxydiphenyl ethers effectively inhibit fatty acid synthesis in vivo and FabI activity in vitro. Resistant mechanisms include up-regulation of fabI expression and spontaneously arising missense mutations in the fabI gene. These results contradict the view that these compounds directly disrupt membranes and suggest that their widespread use will select for resistant bacterial populations.

Animals↗
PubMed1996

Construction of human factor IX expression vectors in retroviral vector frames optimized for muscle cells.

Development of a highly refined human factor IX (hFIX) expression vector system is critical for establishing a durable hemophilia B gene therapy. Here we report construction of a series of retroviral vectors and identification of an optimal basic structure and components for expressing hFIX in skeletal muscle cells. These vectors, which are derived from Moloney murine leukemia virus (MoMLV) with its enhancer sequence in the 3' long terminal repeat (LTR) deleted, contained internal hFIX expression units inserted in forward configuration without or with a viral vector intron sequence (pdL or pdLIn vector frame, respectively) or in inverted configuration without a viral vector intron sequence (pdLi frame). Internal expression units contained a hFIX cDNA or hFIX minigene (hIXm1 or hIXm2) derived from the hFIX cDNA by insertion of a shortened first intron sequence of the hFIX gene. Regardless of the promoter and vector frame used, both hIXm1 and hIXm2 gave 10- to 14-fold higher hFIX expression compared to those with hFIX cDNA. Internal hFIX transcriptional control units of these vectors were composed of various promoters linked with or without the muscle creatine kinase enhancer (Me) sequence. Promoters tested included those of alpha-actin (alpha A775), beta-actin (beta A280), cytochrome oxidase (CO1250 and CO650), myogenin (Mg1031 and Mg353), and Rous sarcoma virus (RSV). beta A200, which was derived from beta A280 by eliminating potential polyadenylation sites, was also tested. As extensively examined with the myogenin promoter, presence of one or multiple copies of Me in the vectors elevated the expression activity in myotubes by 4.5- to 19-fold over those without Me, but not significantly in myoblasts. Similar enhancements in expression activity with Me were also observed with other promoters, except those of RSV and CO. The latter two showed only modest enhancements in the presence of Me. As assayed with myotubes in culture, the general order of hFIX expression activity of various promoters with four copies of Me in the three different vector frames was beta A280 approximately beta A200 > Mg353 > Mg1031 approximately RSV approximately CO650 approximately alpha A775 > CO1250. One exception was that CO650 showed significantly less activity in pdLi-type vectors than in the pdLIn vectors. Based on the systematic analyses of various structural components, a group of pdLi vectors consisting of beta A200, two to four copies of Me, and hIXm2 was identified to have the optimal basic vector structure to be used in retrovirus for hFIX expression in differentiated skeletal muscle cells. The present studies provide the critical first step for establishing a highly refined hemophilia B gene therapy based on skeletal muscle-targeted hFIX gene transfer.

Animals↗
PubMed1996

Identification of phosphorylation sites of human 85-kDa cytosolic phospholipase A2 expressed in insect cells and present in human monocytes.

The phosphorylation sites on the human, 85-kDa cytosolic phospholipase A2 (cPLA2) were identified using recombinant cPLA2 expressed in Spodoptera frugiperda (Sf9) cells. Analysis by high performance liquid chromatography of tryptic digests of 32P-labeled recombinant cPLA2 showed four major peaks of radiolabeled phosphopeptides. The phosphorylated residues were identified as Ser-437, Ser-454, Ser-505, and Ser-727 using mass spectrometry and automated Edman sequencing. Sf9 cells infected with recombinant virus expressing cPLA2 exhibited a time-dependent release of arachidonic acid in response to the calcium ionophore A23187 or the protein phosphatase inhibitor okadaic acid, which was not observed in Sf9 cells infected with wild-type virus. Stimulation of Sf9 cells with A23187 and okadaic acid also increased the level of phosphorylation of cPLA2. Okadaic acid, but not A23187, induced a gel shift of cPLA2 and increased the level of phosphorylation of Ser-727 by 4.5-fold, whereas the level of phosphorylation of the other sites increased by 60% or less in response to both agonists. To determine whether the same sites on cPLA2 were phosphorylated in mammalian cells, human monocytes were studied. Okadaic acid stimulation of monocytes induced a gel shift of cPLA2, increased the release of arachidonic acid, and increased the level of phosphorylation of cPLA2 on serine residues. Comparison of two-dimensional peptide maps of tryptic digests of 32P-labeled recombinant cPLA2 and human monocyte cPLA2 demonstrated that the same peptides on cPLA2 were phosphorylated in mammalian cells as in insect cells. These results show that the Sf9-baculovirus expression system is useful for investigation of the phosphorylation sites on cPLA2. The results also suggest that phosphorylation of the cPLA2 by protein kinases other than mitogen-activated protein kinase may be important for the regulation of arachidonic acid release.

Amino Acid Sequence↗
PubMed1996

Allograft versus autograft anterior cruciate ligament reconstruction: 3- to 5-year outcome.

Sixty-four patients whose knees underwent anterior cruciate ligament reconstruction with nonirradiated allograft tissue were compared with 26 patients whose anterior cruciate ligaments were reconstructed using autograft tissue 3 to 5 years after their operation. Detailed symptoms, activity-level, and functional outcomes, physical examination, and instrumented knee testing were recorded. No statistically significant differences were found except a higher incidence of loss of terminal extension in the autograft group. These differences were small and not considered clinically significant. Laxity and knee scores were similar in both groups. According to International Knee Documentation Committee ratings, overall outcome was normal or nearly normal in 48% of the allograft patients and in 38% of the autograft patients. Overall subjective rating with the Cincinnati Knee Score was 85.8 for the allograft patients and 84.5 for the autograft patients. Allograft tissue provides an acceptable alternative to autograft tissue for reconstruction of the anterior cruciate ligament.

Adult↗
PubMed1996

Depressed adolescents with a history of sexual abuse: diagnostic comorbidity and suicidality.

OBJECTIVE: To determine the nature of comorbid psychopathology and suicidality associated with a history of sexual abuse in depressed adolescents. METHOD: Twenty-four depressed adolescent inpatients with a history of sexual abuse were compared with a matched control group of 24 depressed adolescent inpatients on measures of depression, suicidal ideation and behavior, and posttraumatic stress disorder (PTSD) symptoms. RESULTS: Depressed adolescents with a history of sexual abuse had a higher prevalence of comorbid PTSD than did those without such a history. Chronicity and severity of abuse were significant contributors to a PTSD diagnosis. No differences were found in depression severity, specific depressive symptoms, or suicidal behavior. CONCLUSION: Comorbidity of depressive disorders and PTSD are common among adolescent inpatients with a history of chronic sexual abuse. The need for thorough assessment of depression and PTSD with appropriate interventions for sexually abused adolescents is clear.

Adolescent↗
PubMed1996

Sequential outbreak of influenza A and B in a nursing home: efficacy of vaccine and amantadine.

OBJECTIVE: To describe the sequential occurrence of influenza A and B in a nursing home, and to determine the efficacy of influenza vaccine and/or amantadine treatment with respect to incidence and sequelae. SETTING: The Jewish Home and Hospital for Aged, a skilled-care nursing facility. PARTICIPANTS: Of 499 frail older nursing home residents, 139 contracted influenza during the study period (mean age 87.5 years; SD = 6.7). The residents were followed from February through April 1988. INTERVENTION: Influenza vaccine and/or amantadine. MEASUREMENTS: Episodes of influenza and their sequelae, i.e., pneumonia, hospitalization, and death. RESULTS: The vaccine had no effect on the incidence of influenza-like illness, length of illness, or the associated death rate. It reduced the rate of pneumonia secondary to influenza A and B (relative risk = .57; 95% CI: .37 to .89; P = .023). Amantadine did not affect the attack rate of influenza nor the rate of pneumonia secondary to influenza. It was associated with decreased mortality (relative risk = 0; P = .001), and shorter length of influenza A illness (PWilcoxon = .082). Although the combination of amantadine and vaccine did not affect length of influenza (A or B) illness, it was associated with a significantly lower rate of sequelae (relative risk = .58; 95% CI: .36 to .95; P = .024). CONCLUSION: In this epidemic, the combination of amantadine and vaccine was most effective in reducing the rate of influenza-associated sequelae. The possibility of a "biphasic" epidemic prompts consideration of vaccinating nonimmunized nursing home residents, even though it may be late in the influenza season.

Aged↗
PubMed1996

Baseline (laser) eye examination program.

Eye injury is the primary hazard associated with laser use. A baseline laser eye examination program allows for pre-injury examination and preventive early diagnosis of eye problems (glaucoma). Using portable equipment and a simplified exam format, and staffed by corpsmen and eye care providers, a rapid and accurate large-scale program that is cost efficient can be instituted. A single location for ophthalmic information coupled with recent refraction data will enhance readiness for deployment. For service members and their providers, a new and well-run eye care program will foster a strong and positive bond with the medical department.

Continuity of Patient Care↗
PubMed1995

The inaccessibility of advance directives on transfer from ambulatory to acute care settings.

OBJECTIVE: To investigate the accessibility of patients' previously executed advance directives during an acute hospitalization. DESIGN: Retrospective chart review. SETTING: A large metropolitan teaching hospital, a 514-bed skilled nursing facility, a geriatrics ambulatory care clinic, and a geriatrics group practice office. PATIENTS: One hundred fourteen geriatric patients who had previously executed an advance directive. MAIN OUTCOME MEASURES: The medical records of 180 admissions over 3 years, 1991 through 1993, were reviewed for documentation of patients' advance directive status. RESULTS: Twenty-six percent of patients who had previously executed advance directives had their directives recognized during their hospitalization. Of the subgroup of patients who were judged not to have the capacity to make medical decisions during their admissions, 26% (14/53) had their directives recognized. When the advance directive was recognized, it appeared to influence treatment decisions in 12 (86%) of 14 cases. CONCLUSIONS: Previously executed advance directives are not accessible when patients are admitted to hospitals for acute illness. When such directives are recognized, they are used to influence medical treatment decisions. Further research is needed to define and overcome barriers to this inaccessibility.

Advance Directives↗
PubMed1995

Spontaneous calcium transients regulate neuronal plasticity in developing neurons.

Calcium ions play critical roles in neuronal differentiation. We have recorded transient, repeated elevations of calcium in embryonic Xenopus spinal neurons over periods of 1 h in vitro and in vivo, confocally imaging fluo 3-loaded cells at 5 s intervals. Calcium spikes and calcium waves are found both in neurons in culture and in the intact spinal cord. Spikes rise rapidly to approximately 400% of baseline fluorescence and have a double exponential decay, whereas waves rise slowly to approximately 200% of baseline fluorescence and decay slowly as well. Imaging of fura 2-loaded neurons indicates that intracellular calcium increases from 50 to 500 nM during spikes. Both spikes and waves are abolished by removal of extracellular calcium. Developmentally, the incidence and frequency of spikes decrease, whereas the incidence and frequency of waves are constant. Spikes are generated by spontaneous calcium-dependent action potentials and also utilize intracellular calcium stores. Waves are produced by a mechanism that does not involve classic voltage-dependent calcium channels. Spikes are required for expression of the transmitter GABA and for potassium channel modulation. Waves in growth cones are likely to regulate neurite extension. The results demonstrate the roles of a novel signaling system in regulating neuronal plasticity, that operates on a time scale 10(4) times slower than that of action potentials.

Animals↗
PubMed1994

Ceramide structure predicts tumor ganglioside immunosuppressive activity.

Molecular determinants of biological activity of gangliosides are generally believed to be carbohydrate in nature. However, our studies of immunomodulation by highly purified naturally occurring tumor gangliosides provide another perspective: while the immunosuppressive activity of gangliosides requires the intact molecule (both carbohydrate and ceramide moieties), ceramide structure strikingly influences ganglioside immunosuppressive activity. Molecular species of human neuroblastoma GD2 ganglioside in which the ceramide contains a shorter fatty acyl chain (C16:0, C18:0) were 6- to 10-fold more active than those with a longer fatty acyl chain (C22:0/C24:1, C24:0). These findings were confirmed in studies of ceramide species of human leukemia sialosylparagloboside and murine lymphoma GalNAcGM1b. Gangliosides that contain shorter-chain fatty acids (and are most immunosuppressive) are known to be preferentially shed by tumor cells. Therefore, the results suggest that the tumor cell is optimized to protect itself from host immune destruction by selective shedding of highly active ceramide species of gangliosides.

Animals↗