Finite element evaluation of dentin stress changes following different endodontic surgical approaches

The aim was to compare the effect of different endodontic surgical treatments on the stress distributions in dentin of a simulated first mandibular molar tooth using the finite element analysis method. Three surgical endodontic procedures (apical resection, root amputation, and hemisection) were simulated in a first mandibular molar. Biodentine or mineral-trioxide-aggregate was used to repair the surgery site in apical resection and root amputation models; the remaining root canal spaces were filled with gutta-percha. Access cavities were restored using resin composite. In hemisection model, root canal was filled with gutta-percha, and coronal restoration was finished with a monolithic zirconia crown. A sound tooth model was created as a control model. An oblique force of 300 N angled at 45° to the occlusal plane was simulated. Maximum von Mises stresses were evaluated in dentin near the surgery regions and the entire tooth. Apical resection/Biodentine and apical resection/mineral-trioxide-aggregate models generated maximum von Mises stresses of 39.001 MPa and 39.106 MPa, respectively. The recorded maximum von Mises stresses in root amputation models were 66.491 MPa for root amputation/Biodentine and 73.063 MPa for root amputation/mineral-trioxide-aggregate models. The highest maximum von Mises stress value among all models was observed in the hemisection model, measuring 138.87 MPa. Hemisection induced the highest von Mises stresses in dentin, followed by root amputation and apical resection. In apical resection, Biodentine and mineral-trioxide-aggregate did not show a significant difference in stress distribution. Biodentine in root amputation may lead to lower stresses compared to mineral-trioxide-aggregate.

Dexpanthenol and ascorbic acid ameliorate colistin-induced nephrotoxicity in rats

OBJECTIVE

Colistin is a potent antibiotic which is mainly preferred in the treatment of multidrug-resistant (MDR) gram-negative bacilli. However, due to the increased risk of acute kidney injury following its use, the clinical application is limited. This nephrotoxicity is known to be induced by oxidative stress and related inflammation. In this study on rats, potent antioxidants Dexpanthenol (DEX) and Ascorbic acid (Vit C) have been administered in combination with Colistin to find out whether they would weaken Colistin's nephrotoxic effects.

MATERIALS AND METHODS

Inflammation biomarkers were studied with enzyme-linked immunosorbent assay (ELISA) kits, and oxidative stress biomarkers were studied with different photometric methods in blood and tissue samples taken after treatment with DEX and Vit C in rats with colistin nephrotoxicity. In addition, inflammation and necrosis in the kidney tissues were examined pathologically.

RESULTS

It has been observed in the serum and tissue samples that DEX and Vit C decrease oxidative stress and inflammation biomarkers, therefore acting as nephroprotective agents.

CONCLUSIONS

These compounds have been found to ameliorate the nephrotoxic effects of Colistin, which were demonstrated in the rats treated with Colistin, as well as the combinations.

Integrase inhibitor-based antiretroviral treatments decrease oxidative stress caused by HIV infection

OBJECTIVE

Several chronic illnesses, including HIV infection are associated with oxidative stress. In addition to HIV itself, some antiretrovirals also increase oxidative stress while decreasing viral replication. To investigate the alterations in oxidative stress parameters and thiol-disulphide homeostasis in people living with HIV who were receiving integrase inhibitor-based antiretroviral therapy.

PATIENTS AND METHODS

Thirty treatment-naive adult people living with HIV were prospectively enrolled in the study. Sera were collected from patients twice: at the beginning of antiretroviral therapy (group 1) and 6 months later (group 2). Thirty age-matched healthy volunteers were enrolled in the study as the control group (group 3). Serum levels of total antioxidant status (TAS) and total oxidative status (TOS) were determined using an automated measurement method. Serum malondialdehyde (MDA) and protein carbonyl (PC) levels were measured spectrophotometrically. CD4+ T-cells were counted flow cytometrically. A mathematical equation was used to calculate the oxidative stress index (OSI) and determine disulfide levels (DIS).

RESULTS

TOS, OSI, MDA, and PC levels were significantly increased in treatment-naive people living with HIV than in those receiving ART (p<0.001). Total and native thiol were significantly lower in both HIV-infected groups than in the control group (p<0.001). PC and MDA levels were significantly higher in both HIV-infected groups than in the control group (p<0.001). In correlation analysis, MDA and age were negatively correlated, whereas TAS was positively correlated with CD4+ T-cell count in treatment-naive people living with HIV. Age was positively correlated with TOS (r:0.421, p:0.023) in healthy controls.

CONCLUSIONS

Integrase inhibitor-based antiretroviral treatments decrease the oxidative stress caused by HIV infection and may be a good therapeutic option in people living with HIV.

Evaluation of Stress Distributions in Mandibular Molar Teeth with Different Iatrogenic Root Perforations Repaired with Biodentine or Mineral Trioxide Aggregate: A Finite Element Analysis Study

INTRODUCTION

In this study, finite element analysis was used to evaluate the stress distributions in simulated mandibular molar teeth with various iatrogenic root perforation types after reparation with Biodentine (Septodont, Saint-Maur-des-Fossés, France) or mineral trioxide aggregate (MTA).

METHODS

An extracted human mandibular molar tooth was scanned using a micro-computed tomographic device, and a 3-dimensional solid model was created. Then, 3 different iatrogenic perforation types (furcation perforation [FP], strip perforation [SP], and post drill perforation [PDP]) and 2 different repair materials (MTA and Biodentine [BD]) were simulated on the model. In addition, a sound tooth (ST) model (control) and a model left unrepaired for each type of perforation were created; then, access cavities were restored using resin composite, except for the sound tooth model. Consequently, a total of 10 experimental models were designed. An oblique force of 300 N angled at 45° to the occlusal plane was simulated. Evaluations of von Mises stress were performed in the perforated regions.

RESULTS

Maximum von Mises stress values were 7.76 MPa for ST/corresponding to the FP region, 8.48 MPa for ST/corresponding to the SP region, 14.20 MPa for ST/corresponding to the PDP region, 10.89 MPa for FP /MTA, 7.65 MPa for FP/BD, 14.67 MPa for FP/unrepaired, 15.92 MPa for SP/MTA, 15.82 MPa for SP/BD, 21.95 MPa for SP/unrepaired, 10.20 MPa for PDP/MTA, 9.17 MPa for PDP/BD, and 17.86 MPa for PDP/unrepaired.

CONCLUSIONS

The results of this finite element analysis indicated that BD models showed lower maximum von Mises stress values than the MTA models, and SPs exposed higher stress concentrations in root perforation regions than FPs and PDPs. The use of MTA and BD may reduce the risk of potentially harmful stress in root perforation regions.

The effect of two calcium silicate-based and one epoxy resin-based root canal sealer on postoperative pain: a randomized controlled trial

AIM

To compare the effect of two calcium silicate-based (Endoseal MTA and EndoSequence BC Sealer) and an epoxy resin-based (AH Plus) root canal sealer on postoperative pain following single-visit root canal treatment on molar teeth.

METHODOLOGY

Patients (n = 90) having one first or second molar tooth diagnosed with asymptomatic irreversible pulpitis were randomly divided into three groups according to the sealer used (n = 30) and were treated by two endodontists having at least 10 years of experience. All patients received a single-visit root canal treatment. After the treatments, postoperative pain scores and analgesic intake were recorded at 6, 12, 24 and 48 h, and 3, 4, 5, 6 and 7 days. The data were analysed statistically using non-parametric Kruskal-Wallis tests (for the comparisons of the age and VAS scores), Friedman tests (for the assessments of the changes in pain scores over time), chi-squared tests (for the comparisons of categorical variables) and Spearman's correlation test (for the correlation assessments of the age and gender factors with postoperative pain; α = 0.05).

RESULTS

There were no significant differences amongst the groups in terms of postoperative pain at any time-points assessed (P > 0.05) nor for analgesic intake of patients amongst the groups (P > 0.05). Analgesic intake decreased significantly after 12 h in all groups (P < 0.05).

CONCLUSIONS

The sealers tested in this study were associated with similar levels of postoperative pain and were associated with a similar intake of analgesics.

Efficacy of polishing kits on the surface roughness and color stability of different composite resins

OBJECTIVE

Different polishing kits may have different effects on the composite resin surfaces. The aim of this study was to evaluate the surface roughness and color stability of four different composites which was applied different polishing technique.

MATERIALS AND METHODS

Thirty specimens were made for each composite resin group (nanohybrid, GrandioSo-GS; nanohybrid, Clearfil Majesty Esthetic-CME; hybrid, Valux Plus-VP; micro-hybrid, Ruby Comp-RC; [15 mm in diameter and 2 mm height]), with the different monomer composition and particle size from a total of 120 specimens. Each composite group was divided into three subgroups (n = 10). The first subgroup of the each composite subgroups served as control (C) and had no surface treatment. The second subgroup of the each composite resin groups was polished with finishing discs (Bisco Finishing Discs; Bisco Inc., Schaumburg, IL, USA). The third subgroup of the each composite resin was polished with polishing wheel (Enhance and PoGo, Dentsply, Konstanz, Germany). The surface roughness and the color differences measurement of the specimens were made and recorded. The data were compared using Kruskal-Wallis test, and regression analysis was used in order to examine the correlation between surface roughness and color differences of the specimens (α = 0.05).

RESULTS

The Kruskal-Wallis test indicated significant difference among the composite resins in terms of ΔE (P < 0.05), and there was no statistically significant difference among composite resins in terms of surface roughness (P > 0.05). Result of the regression analysis indicated statistically significant correlation between Ra and ΔE values (P < 0.05, r2 = 0.74).

CONCLUSION

The findings of the present study have clinical relevance in the choice of polishing kits used.

Evaluation of fracture resistance in root canal-treated teeth restored using different techniques

Objective

This study aimed to evaluate the effects of different coronal restoration techniques on fracture resistance of root canal-treated mandibular premolars with mesio-occluso-distal (MOD) cavities.

Materials and Methods

A total of 105 mandibular premolars were selected and randomly distributed into seven groups (n = 15). MOD cavities were prepared except the control group. Root canal treatments were performed. Each tooth was embedded in acrylic resin. Groups were classified as follows; G1: intact teeth (control), G2: unfilled MOD cavity, G3: MOD + composite resin, G4: 10-mm-long fiber post + composite resin, G5: 5-mm-long fiber post + composite resin, G6: Ribbond in the occlusal surface + composite resin, and G7: horizontal fiber post + composite resin. Specimens were loaded using a universal testing machine until fracture occurs. Fracture loads were recorded and statistical interpretations were made (α = 0.05).

Results

In Groups 1, 6, and 7, the greatest fracture resistance was shown and there were no significant differences among these groups (P > 0.05). No significant differences were detected among the Groups 3, 4, and 5 (P > 0.05), whereas the fracture resistances of Groups 1, 6, and 7 were significantly greater than these three groups (P < 0.05). Group 2 had the lowest fracture resistance of all groups (P < 0.05).

Conclusion

Usage of horizontal post or occlusal Ribbond usage increased the fracture resistance of root canal-treated premolars with MOD cavities.

Stress distributions in internal resorption cavities restored with different materials at different root levels: A finite element analysis study

The aim of this study was to evaluate the stresses within simulated roots with internal resorption cavities at the apical, middle and coronal root levels, after obturation with gutta-percha and/or MTA utilising finite element analysis (FEA). Mandibular premolar teeth with internal resorption cavities at different root levels were modelled. Models were restored with gutta-percha and/or MTA. An oblique force of 300 N was applied and stress evaluations were carried out. In the MTA-filled resorption models, the stresses were distributed more homogeneously than the gutta-percha filled models, and the stress concentrations were lower in the remaining dentinal tissues. If the whole root is considered, the fully gutta-percha-filled models generated the highest stress values. Differences between the fully MTA-filled models and hybrid techniques were present only in the apical resorption models. Both the MTA and combination of MTA and gutta-percha can be suggested for use in clinical practice, in cases of internal root resorption cavity obturation.

The efficiency of different irrigation solutions and techniques for the removal of triple antibiotic paste from simulated immature root canals

Introduction

The purpose of this study was to evaluate the efficiencies of different irrigation protocols in the removal of triple antibiotic paste (TAP) from root canals.

Materials and Methods

A total of 127 extracted human maxillary incisor teeth were prepared. Then, root-end resection of 3 mm was accomplished to simulate immature apex model. The root canals were filled with TAP, after 21 days, randomly divided into nine groups according to irrigation systems and solutions (n = 13). Conventional irrigation (CI) groups - Group 1: Root canal irrigation was performed with CI by Peracetic acid (PAA) solution, Group 2: Root canal irrigation was performed with CI by etidronic acid 1-hydroxyethylidene-1, 1-bisphosphonate (HEBP) + sodium hypochlorite (NaOCl) solution, Group 3: Root canal irrigation was performed with CI by ethylenediaminetetraacetic acid (EDTA)/NaOCl solutions. Vibringe system groups - Group 4: Root canal irrigation was performed with Vibringe system by PAA solution, Group 5: Root canal irrigation was performed with Vibringe system by HEBP + NaOCl solution, Group 6: Root canal irrigation was performed with Vibringe system by EDTA/NaOCl solution. EndoVac system groups - Group 7: Root canal irrigation was performed with EndoVac system by PAA solution, Group 8: Root canal irrigation was performed with EndoVac system by HEBP + NaOCl solution, Group 9: Root canal irrigation was performed with EndoVac system by EDTA/NaOCl solution. Control Group: (n = 0). Samples were sectioned vertically, and the amount of remaining medicament was scored for each root half and data were statistically analyzed.

Results

Among the irrigation systems, CI groups showed the highest scores at both apical and coronal parts (P < 0.05). In comparisons among the solutions, at the apical part, PAA groups showed the highest scores (P < 0.05). At the coronal part, EDTA + NaOCl groups showed the lowest score values (P < 0.05).

Conclusion

The use of irrigation systems improved the removal of TAP from the simulated immature root canals. Also, as an irrigation solution EDTA gives more promising results than PAA and HEBP solutions.

The effects of different irrigation protocols on removing calcium hydroxide from the root canals

OBJECTIVE

The aim of this study was to evaluate the efficiencies of different irrigation protocols and solutions in the removal of calcium hydroxide (Ca[OH]2).

MATERIALS AND METHODS

Sixty-eight maxillary incisors were used. Root canals were prepared and filled with Ca(OH)2. Two control (n = 4) and six experimental groups (n = 10) were adjusted: Group 1:1% peracetic acid (PAA) + master apical file (MAF); Group 2: 17% ethylenediaminetetraacetic acid (EDTA) + MAF; Group 3: 9% 1-hydroxyethylidene-1,1-bisphosphonate (HEBP) + MAF; Group 4: 1% PAA + ultrasonic activation (UA); Group 5: 17% EDTA + UA; Group 6: 9% HEBP + UA. The cleanliness of root canal thirds were evaluated with scanning electron microscopy. Statistical analysis were performed (α = 0.05).

RESULTS

At coronal thirds; PAA + UA was superior to EDTA + MAF, HEBP + MAF; and PAA + MAF was superior to EDTA + MAF, HEBP + MAF (P < 0.05). At middle thirds; PAA + MAF and PAA + UA were superior to EDTA + MAF and EDTA + UA; and, PAA + UA was superior to HEBP + MAF (P < 0.05). There were no significant differences among the rest of the experimental groups (P > 0.05).

CONCLUSION

Complete removal of Ca(OH)2could not be achieved by none of the irrigants at all root thirds.

Evaluation of calcium silicate cement bond strength after using gutta-percha solvents

OBJECTIVES

To determine the effect of different gutta-percha solvents (chloroform, Endosolv E, orange oil, and eucalyptol) on the push-out bond strength of calcium silicate cements (CSCs; white mineral trioxide aggregate [WMTA]; capsule-form mineral trioxide aggregate [CMTA], and Biodentine).

MATERIALS AND METHODS

One hundred and fifty extracted single-rooted human mandibular premolars were sectioned into 3-mm-thick slices. The canal lumens were enlarged for 1.35-mm-diameter standardized cavities. The samples were randomly divided into five groups (n = 30) according to the solvent type: G1, chloroform; G2, Endosolv E; G3, eucalyptol; G4, orange oil; G5, no solvent (control). After application of the solvents for 5 min, the specimens were divided into three subgroups (n = 10): (i) WMTA, (ii) CMTA, and (iii) Biodentine. The push-out bond strength was measured. Two-way ANOVA analysis of variance and post hoc Tukey tests were used for analyses (P = 0.05).

RESULTS

The highest push-out bond strength was observed in the Biodentine (P < 0.05), and the values of WMTA and CMTA were not significantly different in all solvent groups (P > 0.05). There were no statistically significant differences among the gutta-percha solvents and control group in WMTA (P > 0.05).

CONCLUSIONS

Gutta-percha solvents used during retreatment decreased the bond strength of Biodentine and CMTA to root dentin. The bond strength of WMTA was not affected by the use of gutta-percha solvents.

Fracture resistance of teeth with oval canal morphology restored using oval and circular posts

The study aimed to evaluate the effects of different post morphologies and placement lengths on the fracture resistance of teeth with oval canal morphology that had been restored with crowns. Extracted mandibular premolars with similar dimensions were decoronated. After the root canal treatment, the teeth were mounted on acrylic blocks. Samples were randomly divided into four groups (n = 10 each). In groups C-10 and C-5, 10-mm- and 5-mm-long circular post spaces were created. In groups O-10 and O-5, 10-mm- and 5-mm-long oval post spaces were ultrasonically created. After post cementation, all specimens were restored with composite cores and prepared at height of 6 mm. Thereafter, all teeth were restored with crowns. After thermocycling, all specimens underwent fracture resistance testing. Oval posts and placement at 10-mm depth showed higher fracture resistance than circular posts and placement at 5-mm depth (P < 0.001). Increased post length and use of oval posts enhanced the fracture strength of teeth with oval canal morphology. Based on the results of this study, although the fracture resistance of teeth restored with crowns was enhanced by deep fiber post placement, the use of oval fiber post is recommended in cases where deep placement is impossible. (J Oral Sci 58, 339-345, 2016).

Report of a Patient With Heparin-induced Thrombocytopenia Type II Associated With IgA Antibodies Only

Heparin-induced thrombocytopenia type II (HIT II) is usually mediated by immunoglobulin G (IgG) antibodies that lead to platelet activation via the FcγIIA-receptor. Here we describe a patient who developed HIT II after aortocoronary bypass surgery. His serum contained an antibody that was detectable by the heparin-induced platelet activation assay (HIPA) and by the ID-HPF4 particle agglutination assay. The flow cytometric analysis showed that the antibody was of the IgA class.

Predictors for limb loss among patient with diabetic foot infections: an observational retrospective multicentric study in Turkey

We aimed to investigate the predictors for limb loss among patients with diabetes who have complicated skin/soft-tissue infections. In this observational study, consecutive patients with diabetic foot infection (DFI) from 17 centres in Turkey, between May 2011 and May 2013 were included. The Turkish DFI Working Group performed the study. Predictors of limb loss were investigated by multivariate analysis. In total, 455 patients with DFI were included. Median age was 61 years, 68% were male, 65% of the patients were hospitalized, 52% of the patients had used antibiotics within the last month, and 121 (27%) had osteomyelitis. Of the 208 microorganisms isolated, 92 (44.2%) were Gram-positive cocci and 114 (54.8%) were Gram-negative rods (GNR). The most common GNR was Pseudomonas; the second was Escherichia coli, with extended spectrum β-lactamase positivity of 33%. Methicillin-resistant Staphylococcus species were found in 14% (29/208). Amputations were performed in 126/455 (28%) patients, 44/126 (34%) of these were major amputations. In multivariate analysis, significant predictors for limb loss were, male gender (OR 1.75, 95% CI 1.04-2.96, p 0.034), duration of diabetes >20 years (OR 1.9, 95% CI 1.18-3.11, p 0.008), infected ulcer versus cellulitis (OR 1.9, 95% CI 1.11-3.18, p 0.019), history of peripheral vascular disease (OR 2, 95% CI 1.26-3.27, p 0.004), retinopathy (OR 2.25, 95% CI 1.19-4.25, p 0.012), erythrocyte sedimentation rate >70 mm/hr (OR 1.6, 95% CI 1.01-2.68, p 0.05), and infection with GNR (OR 1.8, 95% CI 1.08-3.02, p 0.02). Multivariate analysis revealed that, besides the known risk factors such as male gender, duration of diabetes >20 years, infected ulcers, history of peripheral vascular disease and retinopathy, detection of GNR was a significant predictor of limb loss.

Evaluation of the resin cement thicknesses and push-out bond strengths of circular and oval fiber posts in oval-shapes canals

PURPOSE

The aim of this study was to evaluate whether the push-out bond strength varies between oval and circular fiber posts, and to examine the effect on the resin cement thicknesses around the posts.

MATERIALS AND METHODS

Eighteen mandibular premolar roots were separated into two groups for oval and circular fiber posts systems. Post spaces were prepared and fiber posts were luted to the post spaces. Roots were cut horizontally to produce 1-mm-thick specimens. Resin cement thicknesses were determined with a metallographic optical microscope and push-out tests were done.

RESULTS

No significant differences were observed in terms of push-out bond strength between the oval and circular fiber posts (P>.05) The resin cement thicknesses of the oval posts were greater than those of the circular posts group in the coronal, middle and apical specimens (P<.05).

CONCLUSION

In the light of these results, it can be stated that resin cement thickness does not affect the push-out bond strength.

Comparison of colistin-carbapenem, colistin-sulbactam, and colistin plus other antibacterial agents for the treatment of extremely drug-resistant Acinetobacter baumannii bloodstream infections

The purpose of this investigation was to compare the efficacy of colistin-based therapies in extremely drug-resistant Acinetobacter spp. bloodstream infections (XDR-ABSI). A retrospective study was conducted in 27 tertiary-care centers from January 2009 to August 2012. The primary end-point was 14-day survival, and the secondary end-points were clinical and microbiological outcomes. Thirty-six and 214 patients [102 (47.7%): colistin-carbapenem (CC), 69 (32.2%): colistin-sulbactam (CS), and 43 (20.1%: tigecycline): colistin with other agent (CO)] received colistin monotherapy and colistin-based combinations, respectively. Rates of complete response/cure and 14-day survival were relatively higher, and microbiological eradication was significantly higher in the combination group. Also, the in-hospital mortality rate was significantly lower in the combination group. No significant difference was found in the clinical (p = 0.97) and microbiological (p = 0.92) outcomes and 14-day survival rates (p = 0.79) between the three combination groups. Neither the timing of initial effective treatment nor the presence of any concomitant infection was significant between the three groups (p > 0.05) and also for 14-day survival (p > 0.05). Higher Pitt bacteremia score (PBS), Acute Physiology and Chronic Health Evaluation II (APACHE II) score, Charlson comorbidity index (CCI), and prolonged hospital and intensive care unit (ICU) stay before XDR-ABSI were significant risk factors for 14-day mortality (p = 0.02, p = 0.0001, p = 0.0001, p = 0.02, and p = 0.01, respectively). In the multivariable analysis, PBS, age, and duration of ICU stay were independent risk factors for 14-day mortality (p < 0.0001, p < 0.0001, and p = 0.001, respectively). Colistin-based combination therapy resulted in significantly higher microbiological eradication rates, relatively higher cure and 14-day survival rates, and lower in-hospital mortality compared to colistin monotherapy. CC, CS, and CO combinations for XDR-ABSI did not reveal significant differences with respect to 14-day survival and clinical or microbiological outcome before and after propensity score matching (PSM). PBS, age, and length of ICU stay were independent risk factors for 14-day mortality.

Amlodipine-induced immune thrombocytopenia

BACKGROUND AND OBJECTIVES

Drug-induced thrombocytopenia is a serious, but rare, side-effect of treatment with a number of drugs. In this report, we investigate the suspicion that amlodipine, a calcium-channel blocker, was responsible for immune thrombocytopenia in a 79-year-old patient.

PATIENT AND METHODS

Our patient experienced two attacks of thrombocytopenic purpura after 10 years of treatment with amlodipine. Antibodies to platelets were tested by standard methods.

RESULTS

Initially, the platelet count increased owing to treatment with prednisolone and intravenous immunoglobulin G, but decreased shortly after discontinuation of this treatment. The patient's serum was found to contain amlodipine-dependent antibodies to platelets, and he recovered after stopping the drug.

CONCLUSIONS

Amlodipine can induce immune thrombocytopenia, which may strongly resemble autoimmune thrombocytopenia.

Patients with multiple myeloma may safely undergo autologous transplantation despite ongoing RSV infection and no ribavirin therapy

Respiratory syncytial virus (RSV) has been reported as a cause of death among autologous peripheral blood stem cell (ASCT) and marrow recipients and recommendations for therapy with aerosolized ribavirin plus intravenous immunoglobulin (IVIG) made. This therapy is expensive, may be toxic, and causes a significant disruption of patient care. The purpose of this study was to evaluate the morbidity and mortality of RSV infections in patients with multiple myeloma undergoing ASCT without ribavirin therapy. During the months of February-April 1997, 10 consecutive patients (median age 57 years, seven males) with advanced and heavily pretreated myeloma underwent ASCT while having active RSV upper respiratory tract infection. After melphalan (200 mg/m2), all patients became neutropenic (<1000 cells/mm3) for a median of 7 days. Ribavirin was not given to any patient. No patient developed lower respiratory tract infection, required transfer to intensive care or died at a median follow-up of 8 months. One patient developed tracheobronchitis requiring oxygenation by nasal cannula. No delay in the treatment of the underlying myeloma was incurred. RSV infection may not necessarily be a contraindication for ASCT or an indication for therapy with aerosolized ribavirin. Additional studies are needed to confirm our preliminary findings.

Lack of cross tolerance between LPS and muramyl dipeptide in induction of circulating TNF-alpha and IL-6 in guinea pigs

In guinea pigs, lipopolysaccharide (LPS) from gram-negative bacteria and muramyl dipeptide (MDP) from gram-positive bacteria are potent inducers of systemic production of proinflammatory cytokines and fever. However, there is a striking difference between these two bacterial pyrogens in so far as repeated administration of LPS, but not of MDP, in short-term intervals induces tolerance by a progressive downregulation of the systemic cytokine network. In the present study, we investigated MDP-induced fever and the systemic release of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) in LPS-tolerant guinea pigs in comparison with naive animals. Endotoxin tolerance was induced by repeated intramuscular injections of 20 microg/kg LPS at intervals of 3 days. In response to the last of five injections with LPS, systemic production of TNF-alpha and IL-6 as well as the development of a febrile response was abrogated almost completely. Those guinea pigs that had developed an LPS tolerance could, however, produce the same amounts of TNF-alpha and IL-6 as naive animals in response to a challenge with MDP. Also, MDP-induced fever was identical in LPS-tolerant and naive guinea pigs. These results provide evidence for a lack of cross tolerance between LPS and MDP in induction of circulating cytokines and fever in guinea pigs.

Fever and production of cytokines in response to repeated injections of muramyl dipeptide in guinea-pigs

Fever and systemic plasma levels of the cytokines tumour necrosis factor alpha (TNF) and interleukin-6 (IL-6) were measured in guinea-pigs in response to single or repeated intramuscular injections of 100 micrograms/kg muramyl-dipeptide (MDP). In a pilot study (experiment 1), MDP-induced fever was monitored for 8 h. The first fever phase 90-360 min after injection of MDP was followed by the second phase which continued beyond the duration of this experiment. High circulating levels of TNF and IL-6 were detected just before body core temperature started to rise. Within the next 90 min TNF declined again by more than 90% while IL-6 remained elevated. In experiment 2, the effects of repeated injections of MDP (5 times at intervals of 3 days) on the same parameters were investigated. In this paradigm, the febrile response started earlier (60 min after injection) and the first phase of fever remained manifest until 360 min after injection, while the late phase, measured 360-720 min after injection, was attenuated. Circulating, bioactive TNF and IL-6, measured 60 and 180 min after MDP was administered, were the same in response to the first, third, and fifth injection. In experiment 3, the influence of five repeated MDP injections on the abdominal temperature was measured for 22 h, and circulating cytokines were analysed before (360 min after injection) and during (480 min after injection) the late phase of MDP-induced fever. The late phase of MDP-induced fever 7-22 h after injection was attenuated in response to the second and further administrations of this pyrogen. At 6 h after the first, third, and fifth administration of MDP, only traces of TNF alpha were measured, 2 h later no bioactive TNF was detected at all. At these times also IL-6 declined again, compared with the activity of this cytokine measured during the early phase of MDP fever, but was still present in elevated amounts. Compared with the values measured in response to the third and fifth injections of MDP, circulating IL-6 was higher 360 min and 480 min after the first injection. It remains speculative whether the longer duration of elevated IL-6 in plasma is related to the development of the long-lasting, late phase of MDP-induced fever, which was only observed after the first of five repeated injections of MDP at intervals of 3 days.

Bejel in Malatya, Turkey

Bejel is a form of endemic syphilis which is transmitted by non-venereal route. According to our knowledge, no cases of bejel have been reported from Turkey for more than 30 years. In this report, three children and their father who suffer from bejel are presented. The history, physical findings, laboratory investigations, treatment and results of the cases are reviewed, and the related literature is discussed.

Bacteriology of chronic suppurative otitis media

Aspiration of exudate through an open perforation was performed in 183 patients with chronic otitis media. The pus was cultured aerobically and anaerobically. Aerobes only were isolated from 71 patients (39%); 20 patients (11%) had only anaerobes; and 91 patients (50%) had both aerobes and anaerobes. Only 1 specimen had no growth. There were 259 aerobic isolates. Pseudomonas aeruginosa was recovered from 68 patients. Other aerobes commonly recovered included Staphylococcus aureus and Klebsiella pneumoniae. There were 178 anaerobic isolates. Only anaerobic gram-positive cocci were isolated in 20 instances. Sixty-three Bacteroides isolates were recovered, including 12 Bacteroides fragilis group and 21 Bacteroides melaninogenicus.

Bacteriology of antrum in adults with chronic maxillary sinusitis

Swabs of 126 chronically inflamed maxillary sinuses were processed for aerobic and anaerobic bacteria during endoscopy. Bacterial growth was present in 113 of 126 specimens (90%). Anaerobic bacteria were isolated in 100 of 113 culture-positive specimens (88%). Anaerobes only were recovered in 59 cases (52%) and, in 41 (36%), they were mixed with aerobic or facultative bacteria. Aerobic or facultative bacteria were present in 13 cases (12%). A total of 323 isolates (2.8 per specimen), 228 (2.3 per specimen) anaerobes and 95 (1.7 per specimen) aerobes or facultatives, were isolated. The predominant anaerobic organisms were anaerobic cocci and Bacteroides species; the predominant aerobes or facultative bacteria were Streptococcus species and Staphylococcus aureus. These findings indicate the major role of anaerobic organisms in chronic sinusitis.

Ultrasonography in laryngeal cancers

Endolaryngeal spread of laryngeal malignant tumours is usually determined by conventional endoscopy; however, it can not measure the outward extension of the tumour. As an alternative method for assessing the extension of a tumour and detecting metastatic lymph nodes, we have introduced high-resolution ultrasonography (US) in 34 patients with laryngeal epidermoid carcinoma. The ultrasonographic results were compared with the clinical, operative and histological findings. The ultrasonography revealed malignant extensions in the thyroid cartilage in nine cases, in the carotid artery in four cases, and in the thyroid gland in five cases. These were confirmed by surgical and histopathological examinations. Six patients out of the 34 were subclinical cases, who had metastatic lymph nodes, which were diagnosed by US only. In this study US had a sensitivity of 94.44 per cent and a specificity of 93.75 per cent. The sensitivity and specificity of palpation of the cervical lymph nodes were 66.66 per cent and 87.55 per cent respectively. It may be concluded that high-resolution real-time US is a sensitive, simple and inexpensive method for evaluating laryngeal cancers and subclinical cervical lymph node metastasis.