Proceedings from the OMS Resurgence Conference for resuming clinical practice after COVID-19 in the USA.

The COVID-19 pandemic has altered and reshaped the delivery of oral and maxillofacial surgery (OMS) over the past few months. As the USA gradually lifts restrictions and re-opens, surgeons must adjust accordingly. Therefore, the OMS Resurgence Conference: Safely Resuming Practice with a New Normal was organized for 11 May 2020 to gather and disseminate expert opinions and recommendations for OMSs to thoughtfully resume work with efficiency and safety. This manuscript offers a summary of the highlights from the conference discussion.

Multidrug-resistant tuberculosis in South Korea: a retrospective analysis of national registry data in 2011-2015.

BACKGROUND: Multidrug-resistant tuberculosis (MDR-TB) poses a threat to public health as a result of high treatment costs and unsatisfactory outcomes.OBJECTIVE: To elucidate trend, demographic and clinical characteristics and treatment outcomes of patients with MDR-TB between 2011 and 2015 in South Korea.METHOD: Data of patients with MDR-TB diagnosed between 1 January 2011 and 31 December 2015 were retrieved from the nationwide Internet-based TB notification system and analysed retrospectively.RESULTS: During the study period, 5192 MDR-TB patients were notified. We identified an increasing number of MDR-TB patients among foreign populations (from 1.3% to 7.7%), decreasing resistance rates to other anti-TB drugs (e.g., resistance to pyrazinamide, from 40.9% to 28.2%), a decreasing interval from treatment initiation to negative conversion of sputum culture (from 165.7 to 103.7 days) and shortening of treatment duration (719.7 to 613.2 days). However, treatment success rates did not change, and had an average of 65.7%.CONCLUSION: Despite decreasing resistance rates to other drugs and faster treatment responses, treatment outcomes did not improve during the study period. Strict management of MDR-TB patients on treatment should be adopted to improve treatment outcomes.

Robotic-assisted single incision myomectomy in large myoma cases.

INTRODUCTION: Laparo-endoscopic single-incision surgery (LESS) has been developed and gradually adopted for both benign and malignant gynecological procedures. However, LESS has been hindered for use in procedures like myomectomy by limitations in natural architecture and instrumentation, especially in suturing. The da Vinci system features a single-site platform and wristed needle driver, which may help overcome conventional LESS limitations. This case report study describes the feasibility of this robotic single-site (RSS) platform in large myoma cases and offers suggestions. RESULTS: Two cases of myomectomy with large myomas (with maximum diameters of 160 and 120 mm) with different locations, were addressed by RSS. Operative time was 180 and 240 minutes. Estimated blood loss was 200 and 150 ml. Pathologic analysis revealed uterine leiomyomas of 910 and 870 grams. No serious peri- or post-operative complications occurred. DISCUSSION: Myomectomy with large myoma has presented a surgical challenge. RSS myomectomy appears to be a safe and feasible technique for it regardless of its localization. Advantages include less postoperative pain, fast recovery, less impact on quality of life, and improved cosmesis. LESS surgery has been challenging concerning suturing and multi-laparoscopic or multi-port robotic myomectomy can be difficult to extract myoma, especially with morcellation. RSS could be a solution that enables ease of manipflation and extraction.

Robot-assisted laparoscopic adenomyomectomy of adenomyotic nodule implanted in the uterine endometrium manifesting as endometrial cancer: a case report and literature review.

Thickened uterine endometrium with abnormal uterine bleeding highly suggests endometrial hyperplasia or endometrial carcinoma. A case of 35-year-old nulliparous woman came to our department with endometrial mass manifesting as endometrial cancer. Transrectal ultrasonography and magnetic resonance imaging (MRI) showed an 8x6 cm multicystic, ill-defined mass compacted at the uterine endometrium, the anterior wall of the uterus, and 3x3 cm heterogenous mass at the left adnexa. The edometrial mass showed multiple septations with enhancement and low-signal intensity on T2-weighted images. After endometrial biopsy was done and simple hyperplasia without atypia was observed at the histopathologic finding, the patient underwent robot-assisted laparoscopy and diagnosed as adenomyoma at the frozen pathology. After adenomyomectomy, permanent pathologic analysis revealed the same result and she recovered without any complications and responded well to gonadotropin-releasing hormone (GnRH) agonist therapy.

Early intracellular signaling events induced by in vitro metreleptin administration in cardiac myocytes and uterine smooth muscle cells.

Intracellular signaling pathways regulated by leptin have largely been studied in metabolically important organs such as adipose tissue and peripheral blood mononuclear cells, suggesting that leptin plays a key role in pathophysiology of insulin resistance. However, whether synthetic analog of leptin, metreleptin, has similar effects on cardiac myocytes (CM) and uterine smooth muscle cells (USMC) has not yet been studied. Hence, in order to address these questions, we extended previous observations and investigated in vitro signaling study whether metreleptin may activate key signaling pathways. We observed that metreleptin activates Jak2 and STAT3 signaling pathways in dose- and time-dependent manner in CM and USMC. Also, we found that metreleptin increases ERK1/2, JNK and/or p38 phosphorylation in CM. In vitro metreleptin administration also increased ERK1/2 and/or p38 phosphorylation in USMC. By contrast, JNK was not regulated by in vitro metreleptin administration in USMC. Moreover, metreleptin-activated all signaling pathways were blocked by pre-treatment of PD98095 (ERK inhibitor), SB203580 (p38 inhibitor) and/or SP600125 (JNK inhibitor), respectively. Finally, metreleptin increased cell size (hypertrophy) in both CM and USMC. Our data provide novel insights into the role of Jak2, STAT3, ERK1/2, JNK and/or p38 as probable mediators of the action of leptin in regulating hypertrophy in CM and USMC.

Effects of alendronate on the peri-implant bone in rats.

OBJECTIVES: The purpose of this study was to determine the effects of alendronate on the peri-implant bone in rat maxillae with the aid of micro-computed tomographic, histologic, and biochemical analyses. MATERIALS AND METHODS: Thirty-six male Sprague-Dawley rats were used. After extraction of the maxillary first molars, each rat was given periodic subcutaneous injections of either alendronate (alendronate group) or saline (control group). Customized implants were placed bilaterally 4 weeks after these injections. The rats were sacrificed at either 4, 8, or 12 weeks after implantation (4-, 8-, and 12-week groups, respectively; n = 6 rats per group). Microcomputed tomographic and histologic analyses were conducted for all rats. Biochemical analyses were performed at four time points for the 12-week groups. RESULTS: There were no significant differences between the groups on microcomputed tomographic and histologic analyses. All of the measured biochemical parameters tended to decrease over time, with significant differences among some time points within each group. The serum osteocalcin level was significantly lower in the 12-week alendronate group than in the control group (P < 0.05). CONCLUSIONS: Three approaches were utilized in evaluating the effects of alendronate. It appears serum osteocalcin levels may serve as an adjuvant marker for this purpose, although further studies are required to confirm this.

Higher C-peptide levels are associated with regional cortical thinning in 1093 cognitively normal subjects.

BACKGROUND AND PURPOSE: Recent studies have demonstrated an association between increased insulin secretion and cognitive impairment. However, there is no previous study that directly evaluates the association between increased insulin secretion and cortical thickness to our knowledge. Therefore, our aim was to evaluate the effect of hyperinsulinemia, as measured by C-peptide level, on cortical thickness in a large sample of cognitively normal individuals. METHODS: Cortical thickness was measured in 1093 patients who visited the Samsung Medical Health Promotion Center and underwent brain magnetic resonance imaging (MRI) and a blood test to measure C-peptide concentration. Automated surface-based analyses of the MRI data were used to measure cortical thickness. C-peptide levels were divided into quartiles for comparison. Patients in the first to third quartiles were used as the reference category. RESULTS: Patients in the highest quartile group (Q4) of C-peptide levels showed cortical thinning, predominantly in both medial temporal lobes, the right inferior temporal gyrus, both medial prefrontal lobes and the right superior parietal lobule, compared with the lower quartile groups (Q1-Q3) after controlling for age, gender, body mass index, history of hypertension, hyperlipidemia, previous stroke, cardiovascular disease and fasting glucose level. CONCLUSIONS: A higher C-peptide level is associated with regional cortical thinning, even in cognitively normal individuals.

Comparison of alfuzosin 10 mg with or without propiverine 10 mg, 20 mg in men with lower urinary tract symptom and an overactive bladder: randomised, single-blind, prospective study.

PURPOSE: The efficacy and safety of treatment with alfuzosin 10 mg plus propiverine 10 or 20 mg in men with lower urinary tract symptoms (LUTS) and an overactive bladder were investigated. MATERIALS AND METHODS: In this parallel-arm, prospective, multicentre, single-blind study, men who were ≥ 40 years old, had an International Prostate Symptom Score (IPSS) of ≥ 8, an Overactive Bladder Symptom Score (OABSS) of ≥ 3 and an OABSS urgency item score of ≥ 2 were randomised in a 1 : 1 :1 ratio to receive alfuzosin 10 mg alone (Group A) or with propiverine 10 mg (Group B) or 20 mg (Group C) for 8 weeks. Four and 8 weeks after commencing treatment, OABSS was measured along with IPSS, maximal urinary flow rate (Qmax ) and postvoid residual volume (PVR). Adverse events were recorded. RESULTS: A total of 135 men, including 43 in Group A, 48 in Group B and 44 in Group C, completed the study. Relative to baseline, all groups demonstrated significant reductions in OABSS and the IPSS after eight treatment weeks (p < 0.005). The improvement of OABSS in Group C was significantly greater than Group A and B (Group A: 0.70 ± 1.94; Group B: 2.50 ± 2.98; Group C: 4.30 ± 3.40; p < 0.005). An observed improvement of Qmax and PVR in the three groups did not achieve statistical significance. Overall adverse event rates were higher in Group C but not significant compared with others. CONCLUSION: In patients with LUTS and overactive bladder, combined therapy with alfuzosin 10 mg plus propiverine 20 mg was significantly more effective than alfuzosin monotherapy and propiverine 10 mg combined therapy in terms of improving OABSS while not significantly affecting Qmax or PVR.

The effects of ErhBMP-2-/EGCG-coated BCP bone substitute on dehiscence around dental implants in dogs.

OBJECTIVES: The purpose was to evaluate the effect of Escherichia coli-derived recombinant human bone morphogenetic protein-2 (ErhBMP-2)-/epigallocatechin-3-gallate (EGCG)-coated biphasic calcium phosphate (BCP) and titanium barrier membrane on dehiscence defects in dogs. MATERIALS AND METHODS: In five mongrel dogs, the dehiscence bony defects around dental implants were surgically created and in total three implants were placed at edentulous ridge of which teeth had been extracted 12 weeks before. For the control group, BCP was applied to the dehiscence defect. For experimental groups, ErhBMP-2-coated BCP and ErhBMP-2-/EGCG-coated BCP were applied. The newly designed titanium barrier membrane was used to apply all the defects. The defects were evaluated histologically and histometrically after 12 weeks. The comparative statistics of the groups were obtained through Kruskal-Wallis test. RESULTS: In bone-to-implant contact (BIC), bone density (BD), bone regeneration height (BRH), and bone mineralization apposition rate (BMAR), differences among groups were not found. ErhBMP-2/EGCG group appeared to have higher value. In fluorescence analysis, bone remodeling around graft material was more active in the ErhBMP-2/EGCG group. CONCLUSION: Within the limit of this study, it is reasonable to assume that BMP-2-/EGCG-coated biphasic BCP and the newly designed titanium membrane were more beneficial in dehiscence defect healing with increased bone remodeling.

High-throughput on-chip leukemia diagnosis.

Advances in lab-on-a-chip technologies enabled programmable, reconfigurable, and scalable manipulation of a variety of laboratory procedures. Samples, reagents, and fluids can be precisely controlled; buffer temperature, pH, and concentration control systems as well as a variety of detection systems can be integrated on a small chip. These advantages have attracted attention in various fields of clinical application including leukemia diagnosis and research. A lot of research on lab-on-a-chip based diagnosis has been reported and the field is rapidly expanding. This review describes recent developments of lab-on-a-chip technologies as solutions to challenges for high-throughput leukemia diagnosis.

Amylin-induced downregulation of hippocampal neurogenesis is attenuated by leptin in a STAT3/AMPK/ERK-dependent manner in mice.

AIMS/HYPOTHESIS: Both leptin and insulin sensitivity have been linked with pathophysiological processes involving the central nervous system in general, and the hippocampus in particular, but the role of leptin in hippocampal neurogenesis has not yet been elucidated. Also, no previous studies have evaluated whether amylin or the endogenous insulin sensitiser adiponectin interact with leptin to alter hippocampal neurogenesis in mouse hippocampal neuronal (HN) cells or investigated the role of leptin, amylin or adiponectin signalling in mouse HN cells. METHODS: Hippocampal neurogenesis and leptin, amylin and adiponectin signalling were studied in vitro using mouse H19-7 HN cell lines. RESULTS: Amylin decreased cell proliferation in a dose-dependent manner. This effect was diminished by leptin administration and was dependent on signal transducer and activator of transcription 3 (STAT3)/AMP-activated protein kinase (AMPK)/extracellular signal-regulated kinase (ERK). Adiponectin effects were null. We also observed, using immunocytochemical analysis, that amylin decreased activation of microtubule-associated protein 2, a specific neurite outgrowth marker, and synapsin, a specific synaptogenesis marker. By contrast, both effects were attenuated by co-administration of leptin. Finally, we observed that these effects were blocked by pre-treatment with AG490, a STAT3 inhibitor, and STAT3 small interfering RNA administration. CONCLUSIONS/INTERPRETATION: Our data suggest that amylin in pharmacological concentrations may have a neurotoxic effect whereas leptin in physiological and pharmacological concentrations has a protective effect counteracting amylin-decreased hippocampal neurogenesis via STAT3/AMPK/ERK signalling in mouse H19-7 HN cell lines. Overall, our data support a novel role for leptin and amylin in the processes of mouse hippocampal neurogenesis and provide new insights into the mechanisms of neurogenic regulation.

Efficacy of vasectomy reversal according to patency for the surgical treatment of postvasectomy pain syndrome.

This study was conducted to assess outcomes (according to patency) of vasectomy reversal (VR) in qualified patients with postvasectomy pain syndrome (PVPS). A total of 32 patients with PVPS undergoing VR between January 2000 and May 2010 were examined retrospectively. Of these, 68.8% (22/32) completed a study questionnaire, either onsite at the outpatient clinic or via telephone interview. Preoperative clinical findings, preoperative and postoperative visual analogue scale (VAS) pain scores, patency and pregnancy rate and overall patient satisfaction were analyzed. For the latter, a four-point rating of (1) cure, (2) improvement, (3) no change or (4) recurrence was used. The mean age was 45.09±4.42 years and the mean period of follow-up was 3.22 years (0.74-7.41). Patency rates were 68.2% (15/22) and pregnancy rates were 36.4% (8/22). The mean VAS was 6.64±1.00 preoperatively and 1.14±0.71 postoperatively (P<0.001). The difference in the mean preoperative and postoperative VAS was 6.00±1.25 (4-8) in the patency group and 4.43±0.98 (3-6) in the no patency group (P=0.011). A significant difference in procedural satisfaction with surgical outcome was observed between patency and no patency groups (P=0.014). In conclusion, in PVPS patients requiring VR, a significant difference was observed between the patency and no patency groups in terms of pain reduction and the degree of patient procedural satisfaction.

Amylin and leptin activate overlapping signalling pathways in an additive manner in mouse GT1-7 hypothalamic, C2C12 muscle and AML12 liver cell lines.

AIMS/HYPOTHESIS: It has been suggested that amylin amplifies leptin's effects and affects energy homeostasis synergistically with leptin in animals and humans. However, no previous study has reported on amylin and leptin signalling in hypothalamic, muscle and liver cells. METHODS: Leptin and amylin signalling studies were performed in vitro in mouse GT1-7 hypothalamic, C2C12 muscle and AML12 liver cell lines. RESULTS: Treatment of mouse GT1-7 and C2C12 cells with leptin or amylin increased signal transducer and activator of transcription 3 (STAT3) phosphorylation in a dose- and time-dependent manner. In mouse AML12 cells, leptin and amylin produced a biphasic response of STAT3 activity. Importantly, all leptin and amylin signalling pathways were saturable at leptin and amylin concentrations of ∼100 and ∼50 to 100 ng/ml, respectively. Leptin and amylin in combination activated STAT3, AMP-activated protein kinase (AMPK), extracellular signal-regulated kinase (ERK) 1/2 and Akt signalling pathways in an additive manner, effects that were abolished under endoplasmic reticulum (ER) stress. Leptin, but not amylin, increased IRS-1 phosphorylation in GT1-7 hypothalamic, but not in C2C12 muscle and AML12 liver cell lines. CONCLUSIONS/INTERPRETATION: Our data suggest that leptin and amylin have overlapping and additive, but not synergistic, effects in the activation of intracellular signalling pathways. ER stress may induce leptin and amylin resistance in hypothalamic, muscle and liver cell lines. These novel insights into the mode of action of leptin and amylin suggest that these hormones may play an additive role in regulating energy homeostasis in humans.

Efficacy and safety of combination therapy with mirodenafil and α1-blocker for benign prostatic hyperplasia-induced lower urinary tract symptoms accompanied by erectile dysfunction: a multicenter, open-label, prospective study.

This study was conducted to determine whether mirodenafil 100 mg, when administered on demand to patients with benign prostatic hyperplasia (BPH) who are receiving α1-blocker therapy, is safe with regard to the cardiovascular system and whether it improves lower urinary tract symptoms (LUTS) and sexual function. The study involved 121 LUTS/BPH patients who had been treated for at least 3 months with α1-blockers before being administered with mirodenafil 100 mg on demand. Before the start of mirodenafil administration, the blood pressure, heart rate, international prostate symptom score (IPSS)/quality of life (QoL), peak urine flow rate (Qmax), post-voiding residual urine volume (PVR), and international index of erectile function-5 (IIEF-5) of each patient were measured. At 4 and 8 weeks after commencing mirodenafil administration, the blood pressure and heart rate were measured again, any adverse effects of mirodenafil were assessed, and sexual function and voiding symptoms were re-evaluated. Of the 121 patients, 73 (60.3%) completed the 8-week clinical trial. Significant changes in blood pressure and heart rate were not observed during the study. Significant improvements in the IIEF-5 and the IPSS/QoL, but not the Qmax or PVR, were observed. The results of this study suggest that the administration of mirodenafil 100 mg on demand may induce few hypotensive interactions and may be acceptably effective with regard to improving LUTS and sexual function.

Effect of alendronate on healing of extraction sockets and healing around implants.

OBJECTIVES: The purpose of this study was to evaluate the effect of alendronates on healing of extraction sockets and healing around implants in the maxilla of rats. MATERIALS AND METHODS: Twenty-four Sprague-Dawley rats were used. The rats in bisphosphonate group were subcutaneously injected with alendronate (5.0 mg kg(--1)) three times a week for 4 weeks. Both sides of the maxillary first molars were extracted, and customized titanium implants (Ø1.5 × 2.0 mm) were placed immediately into one side. Rats were killed at 3, 7, 14, or 28 days following surgery. RESULTS: New bone formation in extraction sockets, bone area around the implant site, and bone-implant contact were not delayed in the bisphosphonate group. The tartrate-resistant acid phosphatase positive cell count did not differ between bisphosphonate and control groups; however, empty lacunae were observed significantly more in bisphosphonate group. The differences in empty lacunae were shown at different time points between the implant sites and extraction sites: at 7 days after extraction, and at 14 and 28 days after implantation. CONCLUSIONS: Alendronates seemed to decrease bone resorption but not to decrease bone formation. Empty lacunae were observed significantly more at later time points in implant sites compared to extraction sockets.

Structure-activity relationships of piscidin 4, a piscine antimicrobial peptide.

Piscidin 4, an antimicrobial peptide recently isolated from mast cells of hybrid striped bass (Morone chrysops female × Morone saxatilis male), is unusual in that it is twice as long (44 amino acids) as the typical members of the piscidin family. We previously showed that native piscidin 4 had a modified amino acid at position 20, but synthetic piscidin 4 (having an unmodified Trp at position 20) had similar potent activity against a number of both human and fish bacterial pathogens. In this study, the structure and membrane topology of synthetic piscidin 4 were examined using liposomes as model bilayers. Circular dichroism analyses revealed that it had a disordered structure in aqueous solution and folded to form a relatively weak α-helical structure in both membrane-mimetic trifluoroethanol solutions and liposome suspensions. Fluorescence data (piscidin 4 embedded in liposomes) and leakage experiments indicated that piscidin 4 interacted strongly with the hydrophobic part of the liposome. Binding of piscidin 4 to liposomes induced significant blue shifts of the emission spectra of the single Trp residue (Trp20). Quenching of Trp20 by water-soluble quencher (either acrylamide or I-) indicated that the fluorescence of Trp20 decreased more in the presence of liposomes than in buffer solution, thus revealing that Trp20 is less accessible to the quenchers in the presence of liposomes. The relative leakage abilities of piscidin 4 (1 µM) with liposomes were in the following order: DPPC (100%)≥EYPC (94%)>DPPC/DPPG (65%)>EYPC/EYPG (0%). This high activity against DPPC and EYPC liposomes was contrary to our data suggesting that piscidin 4 has a much weaker tendency to form an α-helix than other piscidins, such as piscidin 1. However, the structural similarity of protozoan membranes to EYPC liposomes might explain our discovery of the potent activity of piscidin 4 against the important skin/gill parasite ich (Ichthyophthirius multifiliis), but its negligible hemolytic activity against vertebrate membranes (hybrid striped bass or human erythrocytes). It also suggests that other conformation(s) in addition to the α-helix of this peptide may be responsible for its selective activity. This differential toxicity also suggests that piscidin 4 plays a significant role in the innate defense system of hybrid striped bass and may be capable of functioning extracellularly.

Spontaneous intracranial hypotension: efficacy of radiologic targeting vs blind blood patch.

OBJECTIVE: The aim of this study was to evaluate the efficacies and compare the outcomes of targeted and blind epidural blood patch (EBP) treatments of spontaneous intracranial hypotension (SIH). METHODS: Between January 1999 and December 2009, 56 patients who were diagnosed with SIH received either a targeted or blind EBP. The efficacies of targeted and blind EBPs were evaluated based on degree and duration of symptom relief and on the need for repeat EBP. RESULTS: Fifty-six patients (23 men and 33 women; mean age, 39.6 years; age range, 22-69 years) were included in this study. Thirty-one patients received EBP that targeted CSF leak segments, and 25 received a blind EBP because primary CSF leak sites were not identified (19 patients via a lumbar epidural route, mainly the L 3-4 level, regardless of primary CSF leak site, and 6 patients via upper thoracic epidural spaces, mainly the T4-6 level). In the 31 patients who received a targeted EBP, 27 (87.1%) exhibited clinical improvement after first administration. In contrast, 13 of the 25 patients (52%) who received a blind EBP via a lumbar or upper thoracic epidural route achieved complete recovery. Targeted EBPs were more effective than blind EBPs for the treatment of SIH (p < 0.05). CONCLUSIONS: EBPs targeting CSF leaks can be safely placed under fluoroscopic guidance in patients with SIH and are more likely to be effective than blindly placed EBPs.

Biodegradability and biodegradation rate of poly(caprolactone)-starch blend and poly(butylene succinate) biodegradable polymer under aerobic and anaerobic environment.

The biodegradability and the biodegradation rate of two kinds biodegradable polymers; poly(caprolactone) (PCL)-starch blend and poly(butylene succinate) (PBS), were investigated under both aerobic and anaerobic conditions. PCL-starch blend was easily degraded, with 88% biodegradability in 44 days under aerobic conditions, and showed a biodegradation rate of 0.07 day(-1), whereas the biodegradability of PBS was only 31% in 80 days under the same conditions, with a biodegradation rate of 0.01 day(-1). Anaerobic bacteria degraded well PCL-starch blend (i.e., 83% biodegradability for 139 days); however, its biodegradation rate was relatively slow (6.1 mL CH(4)/g-VS day) compared to that of cellulose (13.5 mL CH(4)/g-VS day), which was used as a reference material. The PBS was barely degraded under anaerobic conditions, with only 2% biodegradability in 100 days. These results were consistent with the visual changes and FE-SEM images of the two biodegradable polymers after the landfill burial test, showing that only PCL-starch blend had various sized pinholes on the surface due to attack by microorganisms. This result may be use in deciding suitable final disposal approaches of different types of biodegradable polymers in the future.

Microbial reduction of uranium under iron- and sulfate-reducing conditions: Effect of amended goethite on microbial community composition and dynamics.

There is a growing need for a better understanding of the biogeochemical dynamics involved in microbial U(VI) reduction due to an increasing interest in using biostimulation via electron donor addition as a means to remediate uranium contaminated sites. U(VI) reduction has been observed to be maximized during iron-reducing conditions and to decrease upon commencement of sulfate-reducing conditions. There are many unknowns regarding the impact of iron/sulfate biogeochemistry on U(VI) reduction. This includes Fe(III) availability as well as the microbial community changes, including the activity of iron-reducers during the uranium biostimulation period even after sulfate reduction becomes dominant. Column experiments were conducted with Old Rifle site sediments containing Fe-oxides, Fe-clays, and sulfate rich groundwater. Half of the columns had sediment that was augmented with small amounts of Fe(III) in the form of (57)Fe-goethite, allowing for a detailed tracking of minute changes of this added phase to study the effects of increased Fe(III) levels on the overall biostimulation dynamics. Mössbauer spectroscopy showed that the added (57)Fe-goethite was bioreduced only during the first thirty days of biostimultuion, after which it remained constant. Augmentation with Fe(III) had a significant effect on the total flux of electrons towards different electron acceptors; it suppressed the degree of sulfate reduction, had no significant impact on Geobacter-type bacterial numbers but decreased the bacterial numbers of sulfate reducers and affected the overall microbial community composition. The addition of Fe(III) had no noticeable effect on the total uranium reduction.