Timothy F. Meiller

Osteonecrosis of the Jaw in Multiple Myeloma Patients: Clinical Features and Risk Factors

PURPOSE To describe the clinical, radiologic, and pathologic features and risk factors for osteonecrosis of the jaw (ONJ) in multiple myeloma (MM) patients. PATIENTS AND METHODS A retrospective review of 90 MM patients who had dental assessments, including 22 patients with ONJ. There were 62 men; the median age was 61 years in ONJ patients and 58 years among the rest. Prior MM therapy included thalidomide (n = 67) and stem-cell transplantation (n = 72). Bisphosphonate therapy included zoledronate (n = 34) or pamidronate (n = 17) and pamidronate followed by zoledronate (n = 33). Twenty-seven patients had recent dental extraction, including 12 patients in the ONJ group. Median time from MM diagnosis to ONJ was 8.4 years for the whole group. RESULTS Patients usually presented with pain. ONJ occurred posterior to the cuspids (n = 20) mostly in the mandible. Debridement and sequestrectomy with primary closure were performed in 14 patients; of these, four patients had major infections and four patients had recurrent ONJ. Bone histology revealed necrosis and osteomyelitis. Microbiology showed actinomycetes (n = 7) and mixed bacteria (n = 9). More than a third of ONJ patients also suffered from long bone fractures (n = 4) and/or avascular necrosis of the hip (n = 4). The variables predictive of developing ONJ were dental extraction (P = .009), treatment with pamidronate/zoledronate (P = .009), longer follow-up time (P = .03), and older age at diagnosis of MM (P = .006). CONCLUSION ONJ appears to be time-dependent with higher risk after long-term use of bisphosphonates in older MM patients often after dental extractions. No satisfactory therapy is currently available. Trials addressing the benefits/risks of continuing bisphosphonate therapy are needed.

Effect of Farnesol on Staphylococcus aureus Biofilm Formation and Antimicrobial Susceptibility

ABSTRACT Staphylococcus aureus is among the leading pathogens causing bloodstream infections able to form biofilms on host tissue and indwelling medical devices and to persist and cause disease. Infections caused by S. aureus are becoming more difficult to treat because of increasing resistance to antibiotics. In a biofilm environment particularly, microbes exhibit enhanced resistance to antimicrobial agents. Recently, farnesol was described as a quorum-sensing molecule with possible antimicrobial properties. In this study, the effect of farnesol on methicillin-resistant and -susceptible strains of S. aureus was investigated. With viability assays, biofilm formation assessment, and ethidium bromide uptake testing, farnesol was shown to inhibit biofilm formation and compromise cell membrane integrity. The ability of farnesol to sensitize S. aureus to antimicrobials was assessed by agar disk diffusion and broth microdilution methods. For both strains of staphylococci, farnesol was only able to reverse resistance at a high concentration (150 μM). However, it was very successful at enhancing the antimicrobial efficacy of all of the antibiotics to which the strains were somewhat susceptible. Therefore, synergy testing of farnesol and gentamicin was performed with static biofilms exposed to various concentrations of both agents. Plate counts of harvested biofilm cells at 0, 4, and 24 h posttreatment indicated that the combined effect of gentamicin at 2.5 times the MIC and farnesol at 100 μM (22 μg/ml) was able to reduce bacterial populations by more than 2 log units, demonstrating synergy between the two antimicrobial agents. This observed sensitization of resistant strains to antimicrobials and the observed synergistic effect with gentamicin indicate a potential application for farnesol as an adjuvant therapeutic agent for the prevention of biofilm-related infections and promotion of drug resistance reversal.

Fungal biofilms and drug resistance.

Candida species, including the novel opportunistic pathogen Candida dubliniensis, are now emerging as major agents of nosocomial infections. Many such manifestations of infections associated with the formation of Candida biofilms include those occurring on devices such as indwelling intravascular catheters. Fungal biofilm-associated infections are frequently refractory to conventional therapy because of resistance to antimicrobial agents. This resistance could be in part due to the surface-induced upregulation of drug efflux pumps. Biofilm-associated Candida show uniform resistance to a wide spectrum of the currently available conventional antifungal agents, which implies that antimicrobial drugs that specifically target biofilm-associated infections are needed. The novel classes of antifungal agents, the lipid formulation of amphotericins, and the echinocandins have demonstrated unique antifungal activity against the resistant Candida biofilms, providing a breakthrough in the treatment of life-threatening invasive systemic mycoses. The use of drugs effective in combating biofilm-associated infections could lead to major developments in the treatment of fungal implant infections.

Natural History of Osteonecrosis of the Jaw in Patients With Multiple Myeloma

PURPOSE To evaluate the natural history of bisphosphonate-related osteonecrosis of the jaw (ONJ) in patients with multiple myeloma. PATIENTS AND METHODS Ninety-seven patients with myeloma from the United States (n = 37) and Greece (n = 60) were observed prospectively for a minimum 3.2 years after ONJ. Patients characteristics were similar with regard to age, bisphosphonate use, and myeloma therapy, except more autologous transplantations were performed on patients in the United States than in Greece (73% v 28%; P < .0001). RESULTS ONJ resolved in 60 patients (62%), resolved and recurred in 12 patients (12%), and did not heal in 25 patients (26%). Dental procedures preceded ONJ in 46 patients (47%) and were more common in those with single episodes (35 of 60, 58%) than recurrent or nonhealing (11 of 37, 30%; P = .007). Recurrent ONJ followed reinitiation of bisphosphonates in six of 12 patients. Greek patients had more bone pain than United States patients (60% v 30%, P = .001) and were less likely to restart bisphosphonates (5% v 35%, P < .0002). Myeloma relapses were more common in patients with recurrent/nonhealing than single-episode ONJ (84% v 62%; P = .02). Median overall survival from myeloma diagnosis was 10.8 years (95% CI; 9.3 years to not reached) and did not differ between patients with single, recurrent, and nonhealing ONJ (P = .2). CONCLUSION ONJ healed in 75% of patients. Patients with spontaneous ONJ have a higher risk of nonhealing and recurrence. Reinitiating bisphosphonates after healing of ONJ is a reasonable option in patients experiencing relapse who are at risk of skeletal complications. Further studies of the pathogenesis and healing of ONJ are needed.

A Novel Immune Evasion Strategy of Candida albicans : Proteolytic Cleavage of a Salivary Antimicrobial Peptide

Oropharyngeal candidiasis is an opportunistic infection considered to be a harbinger of AIDS. The etiologic agent Candida albicans is a fungal species commonly colonizing human mucosal surfaces. However, under conditions of immune dysfunction, colonizing C. albicans can become an opportunistic pathogen causing superficial or even life-threatening infections. The reasons behind this transition, however, are not clear. In the oral cavity, salivary antimicrobial peptides are considered to be an important part of the host innate defense system in the prevention of microbial colonization. Histatin-5 specifically has exhibited potent activity against C. albicans. Our previous studies have shown histatin-5 levels to be significantly reduced in the saliva of HIV+ individuals, indicating an important role for histatin-5 in keeping C. albicans in its commensal stage. The versatility in the pathogenic potential of C. albicans is the result of its ability to adapt through the regulation of virulence determinants, most notably of which are proteolytic enzymes (Saps), involved in tissue degradation. In this study, we show that C. albicans cells efficiently and rapidly degrade histatin-5, resulting in loss of its anti-candidal potency. In addition, we demonstrate that this cellular activity is due to proteolysis by a member of the secreted aspartic proteases (Sap) family involved in C. albicans pathogenesis. Specifically, the proteolysis was attributed to Sap9, in turn identifying histatin-5 as the first host-specific substrate for that isoenzyme. These findings demonstrate for the first time the ability of a specific C. albicans enzyme to degrade and deactivate a host antimicrobial peptide involved in the protection of the oral mucosa against C. albicans, thereby providing new insights into the factors directing the transition of C. albicans from commensal to pathogen, with important clinical implications for alternative therapy. This report characterizes the first defined mechanism behind the enhanced susceptibility of HIV+ individuals to oral candidiasis since the emergence of HIV.

Altered structure and function in the hippocampus and medial prefrontal cortex in patients with burning mouth syndrome

Summary Patients with burning mouth syndrome had altered structure and function of the medial prefrontal cortex and hippocampus, which was partially explained by ongoing pain and depression scores. ABSTRACT Burning mouth syndrome (BMS) is a debilitating, idiopathic chronic pain condition. For many BMS patients, burning oral pain begins in late morning and becomes more intense throughout the day, peaking by late afternoon or evening. We investigated brain gray matter volume (GMV) with voxel‐based morphometry (VBM), white matter fractional anisotropy (FA) with diffusion tensor imaging (DTI), and functional connectivity in resting state functional MRI (rsfMRI) in a tightly screened, homogeneous sample of 9 female, postmenopausal/perimenopausal BMS patients and 9 matched healthy control subjects. Patients underwent 2 scanning sessions in the same day: in the morning, when ongoing pain/burning was low, and in the afternoon, when pain/burning was significantly higher. Patients had increased GMV and lower FA in the hippocampus (Hc), and decreased GMV in the medial prefrontal cortex (mPFC). rsfMRI revealed altered connectivity patterns in different states of pain/burning, with increased connectivity between mPFC (a node in the default mode network) and anterior cingulate cortex, occipital cortex, ventromedial PFC, and bilateral Hc/amygdala in the afternoon compared with the morning session. Furthermore, mPFC‐Hc connectivity was higher in BMS patients than control subjects for the afternoon but not the morning session. mPFC‐Hc connectivity was related to Beck depression inventory scores both between groups and between burning states within patients, suggesting that depression and anxiety partially explain pain‐related brain dysfunction in BMS. Overall, we provide multiple lines of evidence supporting aberrant structure and function in the mPFC and Hc, and implicate a circuit involving the mPFC and Hc in regulating mood and depressive symptoms in BMS.

Prevalence of Candida dubliniensis Fungemia at a Large Teaching Hospital

Six cases of Candida dubliniensis fungemia were identified during an 8-month period in hospitalized patients with various conditions, including human immunodeficiency virus infection. Peptide nucleic acid fluorescent in situ hybridization analysis was used as a rapid and reliable test for differentiating C. dubliniensis from Candida albicans, making it feasible to determine the prevalence of C. dubliniensis fungemia.

Effect of an antimicrobial mouthrinse on recurrent aphthous ulcerations.

Recurrent aphthous ulceration (RAU) remains a clinical problem for many patients. Efforts in prevention and/or treatment with prescription and nonprescription formulations have to date resulted in minimal success at best. A 6-month double-blind clinical study of 96 adults compared a commercially available antimicrobial mouthrinse (Listerine Antiseptic [LA], Warner-Lambert Co., Morris Plains, N.J.) and a hydroalcoholic control to evaluate the effects of vigorous twice-daily rinsing on the incidence, duration, and severity of RAU in persons prone to this disorder. LA rinse and the hydroalcoholic rinse resulted in a statistically significant reduction in the incidence of RAU occurrences from baseline. The duration of lesions and the severity of pain in subjects with ulcers during the treatment period were also significantly reduced in the LA rinse group of patients when compared with baseline. The hydroalcoholic rinse did not show a significant effect versus baseline for either severity or duration of the lesions. Rinsing therefore can be of clinical value in reducing the occurrence of RAU in susceptible patients, and LA rinse can be of significant additional value in decreasing the duration and severity of RAU.

Evaluation of a Reformulated CHROMagar Candida

ABSTRACT CHROMagar Candida is a differential culture medium for the isolation and presumptive identification of clinically important yeasts. Recently the medium was reformulated by Becton Dickinson. This study was designed to evaluate the performance of the new formula of CHROMagar against the original CHROMagar Candida for recovery, growth, and colony color with stock cultures and with direct plating of clinical specimens. A total of 90 stock yeast isolates representing nine yeast species, including Candida dubliniensis, as well as 522 clinical specimens were included in this study. No major differences were noted in growth rate or colony size between the two media for most of the species. However, all 10 Candida albicans isolates evaluated consistently gave a lighter shade of green on the new CHROMagar formulation. In contrast, all 26 C. dubliniensis isolates gave the same typical dark green color on both media. A total of 173 of the 522 clinical specimens were positive for yeast, with eight yeast species recovered. The recovery rates for each species were equivalent on both media, with no consistent species-associated differences in colony size or color. Although both media were comparable in performance, the lighter green colonies ofC. albicans isolates on the new CHROMagar made it easier to differentiate between C. albicans and C. dubliniensis isolates. In conclusion, the newly formulated Becton Dickinson CHROMagar Candida medium is as equally suited as a differential medium for the presumptive identification of yeast species and for the detection of multiple yeast species in clinical specimens as the original CHROMagar Candida medium.

Enhanced Interleukin-1β, Interleukin-6 and Tumor Necrosis Factor-α Production by LPS Stimulated Human Monocytes Isolated from HIV + Patients

Abstract Periodontal disease and tooth loss is a common finding among advanced HIV+ patients. In addition to local oral lipopolysaccharide (LPS) stimulation, systemic up-regulation of monocyte pro-inflammatory cytokine secretion may also be involved in the pathogenesis of HIV disease. A study was undertaken to investigate IL-1β, IL-6 and TNF-α production by resting and LPS stimulated monocytes isolated from HIV + patients and also to investigate the relationship of the patients HIV viral load status to the cytokine production. Whole blood samples in EDTA were collected from 39 HIV-1 infected patients and 20 age and sex matched uninfected controls. Plasma was separated by centrifugation. Viral load was determined using a quantitative RT-PCR. Monocytes were isolated by Ficoll-hypaque gradient separation followed by overnight plastic adherence. Cultured monocytes (1 × 106ml) were stimulated with LPS (1 μg/ml) of either P. gingivalis or F. nucleatum for 2, 8, 24 and 48 h and supernatant fluids were collected. IL-1β, IL-6, and TNF-α levels in supernatant fluids were estimated by ELISA. Increased overall production of IL-1β, IL-6 and TNF-α by LPS stimulated monocytes isolated from HIV-1 infected patients was observed when compared to HIV-1 uninfected controls. LPS stimulated monocytes from HIV-1 infected patients with high viral load (HVL) produced significant (p<0.05) elevations in these pro-inflammatory cytokines when compared to HIV-1 uninfected controls. Both LPS of P. gingivalis and F. nucleatum produced a comparable cytokine production by monocytes after 8 h of stimulation. These data suggest that enhanced IL-1β, IL-6 and TNF-α is produced by monocytes/macrophages isolated from HVL HIV + patients and may be involved in the overall pathogenesis of HIV-1 infection.