Nitric oxide-related products and myeloperoxidase in bronchoalveolar lavage fluids from patients with ALI activate NF-kappa B in alveolar cells and monocytes.

An increased production of NO* and peroxynitrite in lungs has been suspected during acute lung injury (ALI) in humans, and recent studies provided evidence for an alveolar production of nitrated compounds. We observed increased concentrations of nitrites/nitrates, nitrated proteins and markers of neutrophil degranulation (myeloperoxidase, elastase and lactoferrine) in the fluids recovered from bronchoalveolar lavage fluids (BALF) of patients with ALI and correlated these changes to the number of neutrophils and the severity of the ALI. We also observed that BALFs stimulated the DNA-binding activity of the nuclear transcription factor kappa B (NF-kappaB) as detected by electrophoretic mobility shift assay in human alveolar cells (A549) and monocytes (THP1). The level of activation of the NF-kappaB-binding activity was correlated to the concentration of nitrated proteins and myeloperoxidase. Furthermore, in vitro studies confirmed that NO*-derived species (peroxynitrite and nitrites) and the neutrophil enzyme myeloperoxidase by themselves increased the activation of NF-kappaB, thereby arguing for an in vivo pathogenetic role of NO*-related products and neutrophil enzymes to human ALI.

Irbesartan reduces QT dispersion in hypertensive individuals.

Angiotensin type 1 receptor antagonists have direct effects on the autonomic nervous system and myocardium. Because of this, we hypothesized that irbesartan would reduce QT dispersion to a greater degree than amlodipine, a highly selective vasodilator. To test this, we gathered electrocardiographic (ECG) data from a multinational, multicenter, randomized, double-blind parallel group study that compared the antihypertensive efficacy of irbesartan and amlodipine in elderly subjects with mild to moderate hypertension. Subjects were treated for 6 months with either drug. Hydrochlorothiazide and atenolol were added after 12 weeks if blood pressure (BP) remained uncontrolled. ECGs were obtained before randomization and at 6 months. A total of 188 subjects (118 with baseline ECGs) were randomized. We analyzed 104 subjects who had complete ECGs at baseline and after 6 months of treatment. Baseline characteristics between treatments were similar, apart from a slight imbalance in diastolic BP (irbesartan [n=53] versus amlodipine [n=51], 99.2 [SD 3. 6] versus 100.8 [3.8] mm Hg; P=0.03). There were no significant differences in BP normalization (diastolic BP <90 mm Hg) between treatments at 6 months (irbesartan versus amlodipine, 80% versus 88%; P=0.378). We found a significant reduction in QT indexes in the irbesartan group (QTc dispersion mean, -11.4 [34.5] milliseconds, P=0.02; QTc max, -12.8 [35.5] milliseconds, P=0.01), and QTc dispersion did not correlate with the change in BP. The reduction in QT indexes with amlodipine (QTc dispersion, -9.7 [35.4] milliseconds, P=0.06; QTc max, -8.6 [33.2] milliseconds, P=0.07) did not quite reach statistical significance, but there was a correlation between the change in QT indexes and changes in systolic BP. In conclusion, irbesartan improved QT dispersion, and this effect may be important in preventing sudden cardiac death in at-risk hypertensive subjects.

A randomised, double-blind comparison of the angiotensin II receptor antagonist, irbesartan, with the full dose range of enalapril for the treatment of mild-to-moderate hypertension.

OBJECTIVE: To compare the anti-hypertensive efficacy, safety, and tolerability of irbesartan with those of the full dose range of enalapril in patients with mild-to-moderate hypertension. DESIGN AND METHODS: A total of 200 patients were randomised to irbesartan 75 mg or enalapril 10 mg (once daily). Doses were doubled at Weeks 4 and/or 8 if seated diastolic blood pressure (DBP) was > or = 90 mm Hg. Trough blood pressure was measured after completion of a 4- to 5-week placebo lead-in period and again after 2, 4, 8, and 12 weeks of treatment. MAIN OUTCOME MEASURES: Efficacy was evaluated by determining the change from baseline in trough seated blood pressure and the proportion of patients normalised (seated DBP <90 mm Hg) at Week 12. Safety and tolerability were assessed by adverse events reported by physicians, by patients in response to a specific-symptoms questionnaire, by open-ended questioning of patients by physicians, and by clinical laboratory evaluations. RESULTS: Both treatments significantly lowered blood pressure with no significant difference in efficacy between treatment groups. At Week 12, the percentage of patients titrated to either enalapril 40 mg or irbesartan 300 mg was 24% and 28%, respectively. The frequency of overall adverse events was similar in both groups. The incidence of cough in the enalapril and irbesartan groups was 17% and 10%, respectively. In contrast to other AII receptor antagonists, there was no change in uric acid concentrations with irbesartan. CONCLUSIONS: Irbesartan was as effective as the full dose range of enalapril. Irbesartan also demonstrated an excellent tolerability profile.

Clinical evaluation of a constant force electronic probe.

This study aimed to compare, in vivo, a conventional pocket probe with an automatic, computerized, constant force, electronic probe with a discrimination ability up to 0.1 mm. Sixteen adults with moderate chronic periodontitis and free of supra- and subgingival calculus participated in this study. Eight patients were examined by 2 investigators who used both the conventional and the automatic probes, for a total of 4 probings per subject. The remaining 8 patients were examined 4 times by investigator 1, twice with each probe. For each patient the Ramfjord teeth were examined and 6 sites were considered per tooth. Although the pocket depth measurements recorded by the manual probe were consistently deeper than those of the electronic probe, a good correlation was found between both recordings. Moreover, intra- and inter-examiner comparisons showed comparable standard deviations for both probes and small differences in absolute scores. The conventional probe was slightly more reproducible whereas the automated probe had the advantage of automatic registration. The results indicate that both probes can be considered as valuable in clinical practice.

Assessment of periodontal tissues damping characteristics: current concepts and clinical trials.

The reproducibility of an electronic device for the assessment of periodontal tissues damping characteristics was judged by evaluating the inter-examiner, inter-device and day to day variations of the measurements (PTVs). Nine young periodontally healthy volunteers were examined by two examiners (EX-1 and EX-2) and two devices (D-1 and D-2) in the following sequence: EX-1 D-1, EX-2 D-1, EX-1 D-2, and EX-2 D-2. PTVs were obtained at 5 different occasions during the same day. In some instances examiner 2 measured higher scores than examiner 1 with both devices. This difference was statistically significant (P = 0.05), if the total of 900 measurements was considered. The measurements of device 2 were approximately 0.5 PTV units higher, also reaching a statistical significance (P = 0.05). This difference is of limited clinical significance. The day to day variation was evaluated by comparing the scores obtained at 8 a.m. with the ones at the four other periods. The lowest scores were measured at 8 a.m. Only the 11 a.m. and the 2 p.m. measurements differed significantly. The effect of hormonal changes during the menstrual cycle and of smoking habits on PTVs were also evaluated. Ten female periodontally healthy volunteers were examined three times a week, during a period of two menstrual cycles. No significant PTV changes were found during the menstrual cycle. The effect of the smoking habit on PTVs was tested on 23 periodontally healthy patients.(ABSTRACT TRUNCATED AT 250 WORDS)

A method for assessing the damping characteristics of periodontal tissues: goals and limitations.

The Periotest method, an objective, noninvasive clinical diagnostic method, is a dynamic procedure that measures the resistance of the periodontium to a defined impact load. It has been reported that Periotest values depend to some extent on tooth mobility, but mainly on the damping characteristics of the periodontium. Nevertheless, the real clinical meaning of the measurements and some important limitations of the Periotest measuring principle still seem to be poorly understood. In the present study, the relationship between damping characteristics of periodontal tissues and tooth mobility was investigated. The best correlations between tooth deflection and Periotest values were found for teeth showing a certain degree of clinical mobility (R2 from .79 to .91). Nevertheless, this correlation was clearly lower when only healthy subjects were examined (R2 from .43 to .54). The better correlation found for forces greater than 1.0 N indicates that the damping characteristics assessed with the Periotest method are related to secondary tooth movement. The Periotest methodology, measuring principle, and limitations are critically reviewed.

A new easy method for specific measurement of active myeloperoxidase in human biological fluids and tissue extracts.

The SIEFED ("Specific Immunological Extraction Followed by Enzymatic Detection") method already developed for the specific detection of the activity of equine myeloperoxidase (MPO) was adapted for the specific measurement of active human MPO in biological fluids or tissue extracts. The method consists of the extraction of MPO from aqueous solutions by immobilized anti-MPO antibodies followed by a washing (to eliminate the extraction medium and the biological fluid with their possible interfering molecules) and the measurement of the activity of MPO with a detection system containing a fluorogenic substrate, H(2)O(2) and nitrite ions as reaction enhancer. The SIEFED was applied to study active MPO in human biological fluids (plasma, bronchoalveolar lavage fluid and supernatant from carotids extracts). The SIEFED for human MPO has a sensitivity limit of 0.080 mU/mL and showed good precision with intra- and inter-assay coefficients of variation below 10 and 20% respectively within a broad range of MPO activities establish from 0.156 to 473 mU/mL. The SIEFED for human MPO will be useful for the specific detection of active MPO in complex fluids and can be complementary to an ELISA to determine an active/total MPO ratio in healthy volunteers and patients especially in case of chronic or acute inflammatory diseases.

Enzyme-linked immunosorbent assay for immunoglobulin G subclass antibodies specific for enterobacterial Re core glycolipid in healthy individuals and in patients infected by gram-negative bacteria.

An enzyme-linked immunosorbent assay was developed to study the subclass distribution of immunoglobulin G (IgG) specific to the core glycolipid (CGL) of the Re mutant of Salmonella minnesota R595 in serum samples from individuals with an IgG response toward these antigens. In a group of healthy blood donors, we detected predominantly the IgG2 and IgG1 subclasses. In a group of patients in an intensive care unit who developed infectious complications due to gram-negative bacteria, the anti-CGL IgG activity was due mainly to the IgG2 and IgG3 subclasses. In all serum samples found to be IgG positive, the assay for anti-CGL IgG2 was positive. This subclass was revealed to play a predominant role in patients displaying a seroconversion or a significant rise in their antibody response toward CGL. IgG4 was found or appeared only in patients with confirmed bacteremia. In addition, we observed a drop in anti-CGL IgG2 before the death of patients undergoing a septic shock or an irreversible organ failure, suggesting that the anti-CGL IgG2 activity could be used as a marker of the evolution of the illness in this group of patients.

Maxillary bone resorption in patients with mandibular implant-supported overdentures or fixed prostheses.

For several years, implant-supported overdentures have been used with excellent results in rehabilitation of the edentulous mandible. The effect on the antagonistic jaw bone resorption however, has not yet been evaluated. The aim of this study was to examine on orthopantomograms the anterior and posterior maxillary ridge resorption in three groups of patients with different mandibular prosthetic reconstructions: (1) overdentures supported by two implants, (2) fixed prostheses supported by four to six implants, and (3) complete dentures. The results indicated a more pronounced annual bone resorption in complete denture wearers compared to patients with implant-supported overdentures. A limited but continuing bone resorption was observed for the patients with implant-supported overdentures, and a slightly higher annual bone resorption occurred in the implant-supported fixed prosthesis group.

Sequential anti-core glycolipid immunoglobulin antibody activities in patients with and without septic shock and their relation to outcome.

OBJECTIVE: This study follows the sequential changes in anti-lipopolysaccharide antibodies in infected patients with and without septic shock. SUMMARY BACKGROUND DATA: A relation between high endogenous levels of anti-LPS antibodies and protection against bacteremia and septic shock in at-risk patient groups has been observed. However, information on the daily follow-up and kinetics of apparition or disappearance of anti-LPS antibody activities and their relations with the protective properties of the different immunoglobulin classes has not been clearly investigated. METHODS: Two hundred and five septic surgical patients were studied during their stay in the intensive care unit during a period of 3 years. Among these patients, septic shock developed in 54 and 47 died. A sensitive ELISA was used to study circulating IgM and IgG antibodies to the core glycolipid (CGL) region of Salmonella minnesota R595. The activities were measured each day when sepsis occurred and every hour during septic shock. RESULTS: Anti-CGL IgM activity was found in 32% of the septic patients. This response, however, most often appeared to be transient. A strong correlation was observed between the occurrence of septic shock and the absence of anti-CGL IgM activity on admission to the ICU (p < 0.02). Anti-CGL IgG activity was detected in 82% of the patients and better correlated with outcome for patients with high or rising activities during their hospitalization (p < 0.0005). In patients with septic shock or irreversible organ failure, a fall in the anti-CGL IgG activity was observed before death, suggesting that the IgG antibodies were consumed during this acute event. Therefore, the anti-CGL IgG activity measured by ELISA could be used as a marker of the evolution of the illness. CONCLUSIONS: Our observations demonstrate the interest to follow-up the evolution of the anti-CGL antibodies during sepsis. The fall of these antibodies during septic shock and in patients who died was an additional argument to perform, as an additive form, passive antibody therapy to decrease lethality in this group of patients.

Protective effects of polyclonal sera and of monoclonal antibodies active to Salmonella minnesota Re595 lipopolysaccharide during experimental endotoxemia.

Mice were passively immunized with sera from blood donors active for rough lipopolysaccharides (LPS), the J5 (Rc chemotype) mutant of Escherichia coli O111:B4, and the Re595 (Re chemotype) mutant of Salmonella minnesota. All protected the mice against lethal challenge with smooth E. coli WF96 LPS, E. coli and Salmonella rough mutant LPS, or free lipid A. Epitopes recognized by monoclonal antibodies (MAbs) reacting with the LPS of S. minnesota Re595 or lipid A were localized in the 2-keto-3-deoxy-D-manno-octulosonic acid (KDO) region and on lipid A. Core-reactive MAbs reacted with their homologous Re LPS and with free lipid A. One, GL11, cross-reacted with the KDO alone. MAbs GL6, GL11, L.4, L.6, and L.8 protected the actinomycin D-sensitized mice against the lethal effects of LPS from E. coli WF96, Salmonella enteritidis, E. coli J5, S. minnesota Re595, and free lipid A. The GL11 antibody was also protective when injected after LPS challenge. These results indicate that antibodies directed against the core glycolipid of S. minnesota Re595 LPS may be useful as an additive form of therapy that may enable decreased mortality during gram-negative bacterial sepsis.

The effect of periodontal parameters on the subgingival microbiota around implants.

The study aimed to examine the relationship between the subgingival flora around implants and their periodontal parameters. Plaque samples from 561 implants (279 patients) were analyzed by means of differential phase contrast microscopy and compared with the sample site's probing depth, bleeding tendency on probing, and plaque and gingivitis indices. If possible, one implant with deep and one with shallow pockets were selected within the same patient. The impact of the intraoral exposure time on the microbial composition around the implants was examined cross-sectionally, with the same group of patients. Only tendencies can be detected by the latter, and no concrete conclusions can be drawn. From the clinical parameters, increased probing depth was found to detrimentally increase the proportion of spirochetes and motile organisms, whereas the other parameters were found to be of minor importance. For partially edentulous patients only, there was a tendency for increased proportions of spirochetes and motile organisms the longer the intraoral exposure time. These observations emphasize the importance of the periodontal health of the remaining teeth (as a reservoir of pathogenic microorganisms) in partial edentulous patients rehabilitated by means of implants and indicate the importance of shallow pockets around implants (flap trimming when aesthetics and phonetics allow).

Damping characteristics of bone-to-implant interfaces. A clinical study with the Periotest device.

The Periotest device was used to evaluate the damping characteristics of different bone-to-implant interfaces of Brånemark implants. Implant and abutment lengths were found to have a significant influence on Periotest value (PTV). There was no statistical difference between PTVs of implants located in the anterior and posterior areas of the same jaw at abutment connection. No differences were found between PTVs of standard and self-tapping implants. PTVs at abutment connection were highly influenced by the bone quality. The contact with two corticals, one at each extremity of the implant, was of a greater influence in the maxillary than in the mandibular jaw, indicating a firmer anchorage between the bi-cortical implants and the surrounding bone. A progressive decrease of PTVs over time was observed, significant up to 5 years of loading.

Evaluation of dowel space preparation on the apical seal using an image processing system.

The effect of post preparation on the apical seal of endodontically treated specimens was studied. The canals prepared in bovine bone were instrumented and obturated using five obturation techniques: the silver point technique, the lateral condensation of gutta-percha technique, the warm vertical condensation of gutta-percha technique, the Hygenic Ultrafil injection system and the Obtura technique. In addition to these five control groups, the five experimental groups were also subjected to post preparation. In the latter group, the gutta-percha was removed with an engine-driven root canal reamer 48 hours after obturation. Both the control and experimental groups were suspended in a 0.5 per cent crystal violet solution for 48 hours. After dye penetration, the specimens were immersed in liquid nitrogen and then split longitudinally. Linear measurements of the resultant apical dye leakage were determined by image processing. For each obturation technique, all specimens in both the control and experimental groups were recorded if they showed leakage. Using Fisher's exact probability test, it was shown that there was no significant difference between the obturation techniques used.

A direct enzyme-linked immunosorbent assay (ELISA) for antibodies to enterobacterial Re core glycolipid and lipid A. Results in healthy subjects and in patients infected by gram-negative bacteria.

We have developed an ELISA for IgM and IgG antibodies to the core glycolipid (CGL) of the Re mutant Salmonella minnesota R 595, and to lipid A. Anti-CGL antibodies have been detected in sera from 37% of healthy blood donors, whereas anti-lipid A activities were found in 13% of individuals only. The anti-CGL and anti-lipid A activities were examined in patients in a surgical intensive care unit, selected on the basis of a definite risk of infectious complications due to Gram-negative bacteria. Of the patients who developed such infections, the rate of favourable outcome was significantly higher in patients with either stable positive or increasing anti-CGL activities than in patients found to be negative. Our results provide clear evidence that anti-CGL antibodies contribute to host defence against various Gram-negative bacteria.

Oxidative processes in human promonocytic cells (THP-1) after differentiation into macrophages by incubation with Chlamydia pneumoniae extracts.

Human monocytes differentiated into macrophages by Chlamydia pneumoniae were able to oxidize blood lipoproteins, as discovered by Kalayoglu et al. (1998). Using a model of human promonocytic cells (THP-1), the cells were differentiated into macrophages by preincubation with C. pneumoniae extract, and further stimulated by phorbol myristate acetate. In these conditions, the differentiated cells oxidized a thiol compound and released superoxide anion as demonstrated respectively by gas liquid chromatography and electron spin resonance. The thiol oxidation and superoxide anion release were inhibited by diphenyliodonium, a NADPH oxidase and NOsynthase inhibitor, proving that the respiratory burst and the NOsynthase were involved in the oxidation processes occurring in the differentiated THP-1. The role of H(2)O(2) (derived from superoxide anion) was indicated by the enhancing effect of a peroxidase on the thiol oxidation. The presence of alpha-tocopherol in the surrounding medium strongly diminished the oxidation of the thiol target.

Correlation between endotoxin level and bacterial count in bronchoalveolar lavage fluid of ventilated patients.

OBJECTIVE: To assess the predictive value of the endotoxin level in the bronchoalveolar lavage (BAL) and to propose to the clinician a guide in the diagnosis of gram-negative bacterial (GNB) pneumonia. DESIGN: Retrospective and prospective studies to investigate the relation between endotoxin level and quantitative bacterial culture of BAL and to test the predictive value of a defined threshold. SETTING: University hospital general intensive care unit. PATIENTS: In the first part of the study, 77 consecutive ventilated patients with clinical suspicion of nosocomial pneumonia between January 1995 and January 1996. In the second part of the study, 93 consecutive ventilated patients studied prospectively between February 1996 and April 1997. MEASUREMENTS AND MAIN RESULTS: Quantitative cultures for aerobic bacteria were performed directly from the fluid. Bacterial species were determined with standard techniques. The detection of endotoxin in BAL was made using a quantitative chromogenic Limulus assay. In the retrospective analysis, a significant correlation between quantitative GNB cultures and BAL endotoxin levels was observed (r2 = 0.60, p < .0001). An endotoxin level > or = 4 endotoxin units/mL (EU/mL) distinguishes patients with a significant GNB count from colonized patients with a sensitivity of 92.6%, a specificity of 81.4% and a correct classification rate of 84.9%. In the prospective analysis, the 4 EU/mL threshold permits identification of infected patients with a sensitivity of 82.2%, a specificity of 95.6%, and a correct classification rate of 90.3%. The receiver operating characteristic curve analysis showed that the Limulus assay still had a good discrimination power in the prediction of significant bacterial count in BAL fluid. CONCLUSIONS: Endotoxin detection immediately after bronchoscopy is a distinct advantage to the clinician because antimicrobial gram-negative therapy may be immediately justified according to the results.

The influence of splinting procedures on the periodontal and peri-implant tissue damping characteristics. A longitudinal study with the Periotest device.

The aim of the present study was to evaluate the capability of the Periotest device in detecting and monitoring functional changes in the periodontal as well as in the pari-implant damping characteristics. In the first part of this study, 107 teeth were splinted by means of 40 full acrylic fixed prostheses (AFP) and another 37 teeth were splinted by means of 14 ceramometallic fixed prostheses (C-MFP). The Periotest measurements of individual teeth were done the day the fixed prostheses were cemented temporary (PTV 1), and again after a mean observation period of 27.4 days (PTV 2). In the 2nd part, 78 osseointegrated two-stage implants were splinted by means of 23 full acrylic fixed prosthesis (AFP) and other 18 implants were left without it. Using the same abutment length, Periotest measurements were performed, at abutment connections and before installation of the final prosthesis. In a 3rd part, using both implants and teeth as abutments, 29 osseointegrated implants were connected with 25 abutment teeth by means of 7 AFP. The measurements were performed at the beginning of the prosthetic treatment and 2, 4 and 6 weeks later. After splinting teeth by means of AFP for the observation period, no statistically significant reduction in PTVs was found. When on the other hand, a C-MFP was used, PTV 2 showed a significant reduction. The PTVs at abutment connection went down after a period of time, during which some implants were interconnected by means of an AFP and others were not.(ABSTRACT TRUNCATED AT 250 WORDS)

Study of the protective effects of hyperimmune immunoglobulins G and M against endotoxin in mice and rats.

We prepared solutions of human IgM and IgG to various lipopolysaccharide (LPS) species. These were then tested, along with solutions of non-LPS specific human IgG or IgM, for their ability to confer passive immunity against experimental endotoxemia in two animal models. The immunoglobulins were first tested for an effect on the lethality induced by seven different LPSs in actinomycin-D sensitized mice, or by three different bacteria in normal mice. When the immunoglobulins were administered 1 h before challenge, a small protective effect was observed. This protection was dependent upon both the anti-LPS agent, the chemical composition of the LPS, or the strain of gram-negative bacteria used for injection. The anti-LPS IgM and IgG preparations reduced the mortality induced by Escherichia coli but not by Serratia marcescens or Klebsiella pneumoniae, indicating protection by strain-specific antibodies. When the antibodies were preincubated with LPS or bacteria for 30 min before administration, almost complete protection was seen. The influence of these immunoglobulin preparations or of human albumin (as a control) on the hypotensive and vascular-permeabilizing effects of LPS in rats was then studied. A dose-dependent inhibitory effect was observed with IgG preparations and albumin. At 200 mg/kg, anti-LPS IgG reduced the effects of LPS, while at 400 mg/kg, both anti-LPS and normal IgG preparations showed protection, as did human albumin used at the same dose. The IgM-enriched preparation worsened the initial hypotensive phase after LPS, whereas the anti-LPS IgM significantly reduced the second phase of the hypotension, but only at the largest dose of 400 mg/kg. In this second model using the rat, a clear difference between the activity of IgG and IgM was thus observed. We conclude that pretreatment with human immunoglobulins from large plasma pools modestly, but significantly, attenuated the effects of murine and rat Gram-negative sepsis, but that protection was incomplete. Our results suggest that single regimen intervention strategies may not be sufficient to influence the course of the disease.