Infections of intravascular bare metal stents: a case report and review of literature.

OBJECTIVE: The objective of the paper is to present a case of an infected bare metal stent in the left common iliac artery that was removed by an urgent operation, and to review the literature on diagnosis and outcome of infected coronary and non-coronary metal stents. METHODS: A systematic search of the Medline database was performed with the purpose of identifying risk factors, signs and symptoms, imaging strategies, and treatment modalities of bare metal stent infections, both coronary and peripheral. RESULTS: In total, 76 additional studies/case reports (48 non-coronary; 29 coronary) were included and analyzed. Intravascular bare metal stent infections are a rare but serious complication, often leading to emergency surgery (overall: 75.3%; non-coronary cases: 83.3%; coronary cases: 62.1%). In 25.0% of the non-coronary cases, infection led to amputation of an extremity or removal of viscera. Reported mortality was up to 32.5% of the cases (non-coronary: 22.9%; coronary 48.3%). Physicians should always be suspicious of a stent infection when patients present with aspecific symptoms such as fever and chills after stent placement. Additional imaging can be used to detect the presence of a pseudoaneurysm. A PET-CT is an ideal medium for identification of a stent infection. CONCLUSIONS: Intravascular stent infection is associated with a high risk of morbidity and mortality. Surgery is the preferred treatment option, but not always possible, especially in patients with a coronary stent. In selected cases, bare metal stent infections may be prevented by the use of prophylactic antibiotics at stent placement.

The effect of recombinant human stem cell factor and basic fibroblast growth factor on the in vitro radiosensitivity of CD34+ hematopoietic progenitors from human umbilical cord blood.

Human umbilical cord blood (CB) cells selected by immunomagnetic beads for expression of the CD34 antigen were irradiated with increasing doses of x-rays (72 cGy/min). Clonogenic survival of the hematopoietic progenitors, including mixed colony-forming cells (Mix-CFC), erythroid burst-forming units (BFU-E), and granulocyte-macrophage colony-forming cells (GM-CFC), was determined in methylcellulose cultures containing placenta conditioned medium (PCM) and erythropoietin (Epo). Exponential survival curves were fitted to the data of all the colonies, resulting in D0 = 95 cGy for Mix-CFC, 136 cGy for BFU-E, and 136 cGy for GM-CFC. Additionally, the radiosensitivity of CD34+ cells was studied employing cultures containing either recombinant human stem cell factor (rhSCF) or basic fibroblast growth factor (b-FGF) in combination with PCM and Epo. It was found that the colony-forming efficiency (CFE) of non-irradiated CD34+ cells of 5.5% (range 1.4 to 14.4%) did not increase after the addition of SCF or b-FGF to the culture. The radiation response characteristics showed, however, that in the presence of SCF, the D0 value and the extrapolation number n increased significantly. This suggests the stimulation of what operationally is termed "recovery from potentially lethal damage." In contrast, no response modifying effect could be seen for b-FGF.

Short-term effects of early-acting and multilineage hematopoietic growth factors on the repair and proliferation of irradiated pure cord blood (CB) CD34+ hematopoietic progenitor cells.

PURPOSE: Hematopoietic growth factor(s) (GF) may exert positive effects in vitro or in vivo on the survival of hematopoietic stem and progenitor cells after accidental or therapeutic total body irradiation. METHODS AND MATERIALS: We studied the clonogenic survival and DNA repair of irradiated (0.36, 0.73, and 1.46 Gy) CD34+ cord blood (CB) cells after short-term incubation (24 h) with GFs. CD34+ cells were stimulated with basic fibroblast growth factor (bFGF), stem cell factor/c-kit ligand (SCF), interleukin-3 (IL-3), IL-6, leukemia inhibitory factor (LIF), and granulocyte-monocyte colony stimulating factor (GM-CSF) alone or in combination in short-term serum-free liquid suspension cultures (LSC) immediately after irradiation and then assayed for clonogenic progenitors. DNA repair was evaluated by analysis of DNA strand breaks using the comet assay. Survival of CFU-GM, BFU-E, and CFU-Mix was determined and dose-response curves were fitted to the data. RESULTS: The radiobiological parameters (D[0] and n) showed significant GF(s) effects. Combination of IL-3 with IL-6, SCF or GM-CSF resulted in best survival for CFU-GM BFU-E and CFU-Mix, respectively. Combinations of three or more GFs did not increase the survival of clonogenic CD34+ cells compared to optimal two-factor combinations. The D[0] values for CFU-GM, BFU-E, and CFU-Mix ranged between 0.56-1.15, 0.41-2.24, and 0.56-1.29 Gy, respectively. As for controls, the curves remained strictly exponential, i.e., all survival curves were strictly exponential without any shoulder (extrapolation numbers n=1 for all tested GF(s). DNA repair capacity of CD34+ cells determined by comet assay, was measured before, immediately after irradiation, as well as 30 and 120 min after irradiation at 1 Gy. Notably, after irradiation the 2-h repair of cytokine-stimulated and unstimulated CD34+ cells was similar. CONCLUSION: Our data indicate that increased survival of irradiated CB CD34+ cells after short-term GF treatment is mediated through proliferative GF effects on the surviving fraction but not through improved DNA repair capacity.

Single-cell cDNA-PCR: removal of contaminating genomic DNA from total RNA using immobilized DNase I.

A procedure utilizing immobilized DNase I that allows the efficient amplification of cDNA by PCR from a single cell in the absence of contaminating genomic DNA is described. DNase I treated, total RNA derived from single cells was reverse transcribed into cDNA followed by PCR using beta-actin and c-fos specific primers that recognize different exons of the respective genes. Amplification products corresponding to cDNA, but not to genomic sequences, were detected after treatment with immobilized DNase I in samples previously shown to be contaminated with genomic DNA. This method allows the efficient removal of DNA contaminating total RNA derived from a single cell.

Beneficial effect of H2-agonism and H1-antagonism in rat endotoxic shock.

Although histamine release is generally considered harmful in endotoxic shock, several data exist to doubt this view. Own previous studies in rats let us assume a possible beneficial effect only with H1-antagonists, however a detrimental effect on survival with H2-antagonists. Consequently H1- and H2-agonists and antagonists were studied to prove the hypothesis of a beneficial H2-agonistic and H1-antagonistic effect. Two randomized studies were performed in a standardized rat endotoxic shock model (45 mg of Escherichia coli endotoxin/kg body weight (b.w.)). In both, methylprednisolone (50 mg/kg b.w.) and saline were used as positive and negative controls, respectively. Study I compared the effects of H1- and H2-agonists (betahistine, .1 mg/kg/h, and impromidine, 100 micrograms/kg/h) with H1- and H2-antagonists (astemizole and famotidine both 1 mg/kg b.w.; 20 rats/dose). Study II was performed to estimate the dose-response relationship of a new, highly potent H2-agonist with additional H1-antagonistic features (BU-E 75: .01, .1, 1.0, 10, and 100 micrograms/kg/h; 20 rats/dose). Animals receiving impromidine or BU-E 75 all received omeprazole (1 mumol/kg b.w.) to suppress gastric acid secretion. In study I impromidine significantly increased the survival-time and -course compared to famotidine treated animals (p = .01 and p < .05). Study II showed a positive dose-response relationship of BU-E 75 with an increase in survival rates from 30% (.01 microgram/kg/h) to 70% (100 micrograms/kg/h). These data strongly support the hypothesis of a beneficial effect of H2-agonism and H1-antagonism on survival parameters in rat endotoxic shock.

Describing and testing a moderator of the moral judgment and action relationship.

The relationship between moral judgment development and action for Ss who differ in the degree to which justice-based moral judgments influence moral decision making was investigated. First, a method for quantifying Ss' use of justice-based moral judgments in moral decision making (the utilizer variable) is described. Second, 5 moral judgment and action studies are reanalyzed to assess the moderating effect of the utilizer variable information. Results indicate that the relationship between moral judgment scores and action intensifies as utilization increases. Moreover, the utilizer effect appears uniform across different age and educational levels and behavioral domains. These findings support the validity of the utilizer variable and are consistent with recent multiprocess models of moral action that suggest that moral judgements are a necessary, but insufficient, factor in the production of moral action.

DNA-Based Vaccination Primes Tumor-Rejecting T-Cell Responses.

DNA-based vaccination efficiently primes MHC-restricted T-cell responses. This technique specifically stimulates MHC-II-restricted CD4(+) T-cell responses and MHC-I-restricted CD8(+) T-cell responses against "strong" (immunodominant) or "weak" (subdominant or cryptic) epitopes of intracellular, secreted or membrane-associated protein antigens. In many experimental systems, T-cell-mediated effector functions have the potential to control tumor growth. In particular MHC-I-restricted cytotoxic T lymphocytes (CTL) can reject tumors. This has been shown using either defined tumor-associated antigens (TAA), or viral antigens containing well-defined, MHC-binding and CTL-stimulating epitopes that are expressed by transfected tumor cells.

The relationship between moral decision making and patterns of consolidation and transition in moral judgment development.

Following models that describe intraindividual correlates of stage transitions (S. S. Snyder & D. H. Feldman, 1984), this study assessed the relation between a measure of consolidation and transition in moral judgment development and the utility of moral concepts in sociomoral decision making. The study extends previous research in suggesting that individuals use moral concepts differently as they cycle through periods of consolidation and transition. With multiple cross-sectional and longitudinal samples, findings indicate that participants' reliance on a Kohlbergian moral framework as measured by the Defining Issues Test is highest during periods of consolidation and lowest during transitions. As participants move into periods of consolidation, the utility of moral stage information increases. Thus, this study indicates that the consolidation and transition model can be used to help identify individuals who are more or less likely to use Kohlberg's moral stages in their moral decision making.

Individual moral judgment and cultural ideologies.

Moral judgment cannot be reduced to cultural ideology, or vice versa. But when each construct is measured separately, then combined, the product predicts powerfully to moral thinking. In Study 1, 2 churches (N = 96) were selected for their differences on religious ideology, political identity, and moral judgment. By combining these 3 variables, a multiple correlation of .79 predicted to members' moral thinking (opinions on human rights issues). Study 2 replicated this finding in a secular sample, with the formula established in Study 1 (R = .77). Individual conceptual development in moral judgment and socialization into cultural ideology co-occur, simultaneously and reciprocally, in parallel, and not serially. Individual development in moral judgment provides the epistemological categories for cultural ideology, which in turn influences the course of moral judgment, to produce moral thinking (e.g., opinions about abortion, free speech).

Do 5-F-catheters reduce the incidence of a pseudoaneurysm?

Femoral artery pseudoaneurysm is a major problem in patients undergoing cardiac catheterization. This study describes our experience with 5 French (5 F) and 7 French (7 F) introduction sheaths and 7 investigators at our institution regarding the incidence of pseudoaneurysms. During 54 months (1/1990-6/1994) 8715 consecutive patients after diagnostic cardiac catheterization were first clinically checked for pseudoaneurysm and in case of suspicion a duplex sonography was performed. In 86 (1%) patients, 44 (52%) women and 42 (48%) men, mean age 63 +/- 9.7 years we observed this complication by duplex ultrasound. 54 (62%) patients had arterial hypertension, 18 (20%) diabetes and only 3 (3.6%) had peripheral arteriosclerosis. An antithrombotic medication was used in 60% (52 patients). As compared to a control group of 450 consecutive patients a pseudoaneurysm was significantly more likely to occur in patients with a history of hypertension (63% vs 25%, p < 0.0001). Women are also at higher risk representing 51% of all pseudoaneurysms as compared to 29% in the control group (p < 0.0001). Using 7-F catheters more pseudoaneurysms occurred (82/7183; 1%) than using 5 F (4/1532; 0.2%) introduction sheaths (p = 0.0005). There were also significantly more pseudoaneurysms caused by investigator 1 (21/787; 2.7%) as compared to the other investigators (65/7829; 0.8%), (p = 0.0002). Investigator 1 had a more distal puncture technique than the others. Pseudoaneurysms complicating cardiac catheterization occur 5-times more frequent using 7 F (1%) as compared to 5 F catheters (0.2%). Moreover distal puncture site is associated with a higher frequency of pseudoaneurysms.

Local venous thrombosis after cardiac catheterization.

Pulmonary embolism is a rare but life-threatening complication of cardiac catheterization. Underlying deep venous thrombosis (DVT) is often not detectable clinically. To determine the true incidence of DVT the authors prospectively studied 450 consecutive patients (29% women, 71% men, mean age: fifty-eight years) undergoing a diagnostic cardiac catheterization. Patients were examined clinically and by duplex sonography with a high-resolution (5 or 7.5 MHz) transducer before and twenty-four hours after catheterization before mobilization. Duplex sonography excluded complete proximal DVT in all patients. Only partial occluding thrombi (pDVT) were detected in 11 (2.4%) patients. The thrombi were always localized at the puncture site. In 2 patients a difference was found in the circumferences of the legs, but no other clinical signs of DVT were seen. With use of continuous wave (cw) Doppler sonography, only 3 of these 11 patients (27%) showed a spontaneous (s) sound. Phlebography was performed in 4/11 patients (36%). In 2 patients the diagnosis was confirmed; in 1 patient extravenous compression was assumed, and the other demonstrated a normal-appearing phlebography at the time of investigation. Logistic regression analysis yielded a 3.5 times higher risk for developing a pDVT if a venous puncture was performed in addition to arterial puncture. Furthermore a 9.8 times higher risk was found if more than one venous puncture was necessary. During the follow-up no patient developed clinical signs of pulmonary embolism. The results of this study demonstrate that DVT is a rare complication of cardiac catheterization (0/450 patients), but pDVT occurred in 2.4%. Risk factors for pDVT are the venous puncture itself and multiple puncture attempts. Clinical relevance of pDVT remains to be determined.

The impact of a dental ethics curriculum on moral reasoning.

This study explored the effects of problem-oriented dental ethics curriculum, consisting of 39 contact hours distributed over four years on moral reasoning development and on attitudes about the value of instruction. Students (n = 720) in the classes of 1985 through 1992 participated in the required curriculum and completed, as freshman and seniors, the Defining Issues Test (DIT), a well-validated test of moral reasoning. In addition, students responded to open-ended questions about the value of ethics instruction. Cross-sectional comparison of the eight classes of entering freshman with two classes of third quarter juniors (n = 265) who completed the DIT prior to implementing the ethic curriculum indicated that the dental curriculum offered prior to 1981 had little influence on moral reasoning. Pre- to posttest DIT comparisons for seven of the eight classes of instructed students indicated statistically significant improvement. Comparison of the effect sizes (Cohen's d) of our intervention with the average effect size reported in a meta analysis of effective interventions indicates that results cannot be attributed to student maturation alone. Analysis of individual change patterns suggest that the success occurred despite a higher than average (17 percent vs. 6 percent) number of students who showed regression from pre- to posttest. Substantive explanations (gender, motivation, regression to the mean) did not appear to account for the change patterns, but theoretical explanations, based on observations in other settings, offer insights for further research and curriculum development. In conclusion, the results indicate that students not only benefit from ethics instruction, but value it.

The validity and reliability of a clinical performance rating scale.

Rating scales are standard tools for evaluating clinical performance in medicine; however, in dentistry they appear to be used solely to evaluate technical skills. A pretest of three performance scales did not reveal the superiority of any one scale, though faculty clearly preferred a 20-item, six-point Likert scale that rated personal, interpersonal, and professional qualities. Directors and co-directors of six group clinics subsequently rated performance of two classes of seniors and one class of juniors. Interrater reliabilities, ranging from .62 to .83 across rater pairs, were superior to reliabilities reported in medical education studies. Although technique grades, preclinical GPA, and performance ratings differentiated students who completed clinical requirements on time (n = 302) from those who did not (n = 83), performance ratings added information about competence that was not reflected in GPA and technique grades. The usefulness of a rating scale appears to be in its potential for giving students feedback and for evaluating program effectiveness.

[Tricuspid valve endocarditis. Demonstration of a rare disease exemplified with 3 case reports]. / Trikuspidalklappenendokarditis. Darstellung eines seltenen Krankheitsbildes anhand dreier Fallberichte.

BACKGROUND: Endocarditis of the tricuspid valve is a rare form of valvular endocarditis and occurs mainly in patients with special risk factors. CASE REPORTS: The three case reports demonstrate 3 young patients (age 30 to 37 years, 2 female and 1 male) with a typical history of those risk factors. The two women were intravenous drug addicts and one of them had suffered already an episode of tricuspid valve endocarditis several years ago. The man developed his infection after implantation of a pacemaker. In all of the three patients the endocarditis was due to infection with staphylococci twice staphylococcus epidermidis and once staphylococcus aureus. In two of the three patients the endocarditis could not be cured by intravenous antibiotics alone and these patients had to undergo cardiac valvular surgery. All patients left the hospital after several weeks without signs of infection. CONCLUSION: In clinical praxis the introduction of a special endocarditis service, a small team which has to be consulted in every suspected case of endocarditis, seems to be beneficial as well as the use of the Duke criteria for diagnosis in those cases.

Infection of endovascular abdominal aortic aneurysm stent graft after urosepsis: case report and review of the literature.

Infection of endovascular abdominal aneurysm stent grafts is an uncommon but known complication. Inoculation with bacteria of the endovascular abdominal aneurysm stent graft during the actual implantation, in the periprocedural hospitalization or later due to an aortoenteric fistula, has been described in the literature. We report a case of endovascular abdominal aortic aneurysm stent graft infection occurring 40 months after implantation in a patient doing well up to an episode of urosepsis. In conclusion, we postulate that poor intraluminal healing of stent grafts, as observed in several explant studies, may result in a higher susceptibility to episodes of bacteremia than prosthetic vascular grafts inserted during open repair. We therefore consider the administration of prophylactic antibiotics in patients with endovascular stent grafts during periods with a likelihood of bacteremia.

A non-specific lipid transfer protein from Arabidopsis is a cell wall protein.

Lipid transfer proteins (LTPs), mediate the transfer of phospholipids between membranes in vitro. However, the in vivo function of LTPs is not known. To determine the precise location of a non-specific LTP from Arabidopsis, a cDNA clone was used to produce an Arabidopsis LTP:protein A fusion. Antibodies raised against the fusion were used to localize the Arabidopsis LTP by immunoelectron microscopy. LTP was found to be located in the cell wall, mainly in epidermal cells. This location appears to be inconsistent with the proposed role of the protein in intracellular lipid transfer.

Processing of exogenous hepatitis B surface antigen particles for Ld-restricted epitope presentation depends on exogenous beta2-microglobulin.

Processing of exogenous hepatitis B surface antigen (HBsAg) particles in an endolysosomal compartment generates peptides that bind to the major histocompatibility complex (MHC) class I molecule Ld and are presented to CD8+ cytotoxic T lymphocytes. Surface-associated 'empty' MHC class I molecules associated neither with peptide, nor with beta2-microglobulin (beta2m) are involved in this alternative processing pathway of exogenous antigen for MHC class I-restricted peptide presentation. Here, we demonstrate that internalization of exogenous beta2m is required for endolysosomal generation of presentation-competent, trimeric Ld molecules in cells pulsed with exogenous HBsAg. These data point to a role of endocytosed exogenous beta2m in the endolysosomal assembly of MHC class I molecules that present peptides from endosomally processed, exogenous antigen.