Exploring Side Effects of Sublingual Immunotherapy: A Systemic Review and Meta-Analysis.

Objective: Sublingual immunotherapy (SLIT) has emerged as a potentially safe and convenient option for allergen immunotherapy for patients with inhalant allergy. Larger studies on the overall side effects and severe reactions anaphylaxis are still lacking. Study Design: Systematic review and meta-analysis. Setting: Author's review was completed in the University of Texas Medical Branch. Methods: A systematic review and meta-analysis of prospective clinical trials focusing on SLIT safety published from January 1, 2001, to December 31, 2021, was conducted. Results: Twenty-six studies were included with analysis of 7827 patients, representing over 2.7 million SLIT doses. All studies focused on single-antigen immunotherapy. The mean duration of treatment was 11.54 months. Local side effects were present in 40.83% of patients [95% confidence interval (CI) 24.78-57.96]. Systemic side effects were encountered in 1.09% of SLIT patients (95% CI 0.57-1.78). Anaphylaxis was reported in 0.13% of patients (95% CI 0.06-0.22). Discontinuation rates due to side effects were low, at 4.32% of patients (95% CI 3.28-5.49). Conclusion: This meta-analysis shows that single-antigen SLIT is well-tolerated, with overall low rates of systemic side effects including anaphylaxis. Although there is a high rate of minor local side effect, the treatment attrition during the first year is low. With growing allergy burden worldwide, SLIT is a convenient and economically feasible option for immunotherapy. Further work is needed to evaluate long-term safety and efficacy of single as well as multi-antigen SLIT, including quality of life assessments.

Denosumab-Induced Maxillary Osteonecrosis: A Case Study on Long-Term Complications in Multiple Myeloma Treatment.

Background: Targeted therapies like denosumab have revolutionized multiple myeloma (MM) treatment, improved patient outcomes while introducing long-term complications. This study explores a rare instance of delayed maxillary osteonecrosis post-denosumab therapy, delving into its pathophysiology and management. Methods: A 40-year-old male MM patient who developed a painful palatal lesion post denosumab treatment and diagnosed of maxillary osteonecrosis by computed tomography scan and surgical biopsy is presented. Treatment history, symptom progression, and response to the PENTOCLO protocol were analyzed. Results: Post-denosumab discontinuation osteonecrosis highlights its prolonged impact on bone metabolism. PENTOCLO treatment protocol led to significant improvement. Genetic factors influencing osteonecrosis susceptibility have been discussed and considered. Conclusions: This case underscores the need for vigilance regarding long-term complications in MM survivors, preventive strategies, including regular dental evaluations and reducing invasive dental procedures, are crucial. We advocate for an interdisciplinary approach and further research into tailored prevention and management of osteonecrosis in cancer survivors.

CT volumetry study of microfat graft survival from different donor sites in augmenting the enophthalmic socket.

PURPOSE: To evaluate autologous fat grafts harvested from the abdomen versus the thigh for treating the enophthalmic socket using CT volumetry. METHODS: A randomized prospective interventional study including 20 patients suffering from unilateral enophthalmic socket. Pre-operative clinical assessment included photographs, exophthalmometry reading as well as CT volumetry for volume deficit calculations and the harvesting site was randomly allocated (abdomen or thigh). All patients completed 6 months of follow-up. Exophthalmometry change and percentage of retained fat with the globe included and without it at follow-up were measured. RESULTS: Microfat graft survival showed no statistically significant correlation with sex, age, or donor site. Mean percentage of retained fat with globe and without it were 14.75% and 25.31%, respectively. Difficulty of extraction and degree of volume deficit correlated significantly with percentage of fat retained. Exophthalmometer change correlated significantly with percentage of fat retained. CONCLUSION: Autologous fat grafting is a safe and effective technique for volume augmentation of enophthalmic sockets regardless of its harvesting site. CT volumetry has an important role in accurately measuring the volume deficit as well as the postoperative results.

Periocular methotrexate versus periocular triamcinolone injections for active thyroid-associated orbitopathy: a randomized clinical trial.

PURPOSE: To assess the efficacy and safety of periocular injections of methotrexate versus triamcinolone in the management of active thyroid-associated orbitopathy. STUDY DESIGN: Prospective, double-masked, randomized clinical trial. METHODS: Participants with bilateral active, moderate-to-severe thyroid-associated orbitopathy were randomly assigned to receive three periocular injections of 7.5 mg methotrexate in one orbit and three periocular injections of 20 mg triamcinolone in the contralateral orbit. RESULTS: Among the enrolled 25 patients, 18 patients completed the study. A statistically significant reduction of the mean clinical activity score was detected in both arms (from 5.2 ± 0.89 at baseline to 0.9 ± 1.7 at study endpoint, p-value < 0.001 in the methotrexate arm, and from 5.1 ± 0.9 at baseline to 1 ± 1.7 at study endpoint, p-value < 0.001 in the triamcinolone arm), mean proptosis also decreased in both arms (from 25.2 ± 3.4 mm at baseline to 23.8 ± 3.7 mm at study endpoint, p-value = 0.01 in the methotrexate arm, and from 24.2 ± 3.06 mm at baseline to 23.2 ± 3.3 mm at study endpoint, p-value = 0.049 in the triamcinolone arm). Lid aperture and soft tissue signs improved significantly in both arms in comparison to baseline. A statistically significant reduction in the intraocular pressure was observed in the methotrexate arm but not in the triamcinolone arm. 88.9% of patients in both arms were overall responders at 6 months. There was no significant difference in mean CAS, proptosis, lid aperture or rate of responders between the two arms at any visit. Both drugs were found to be safe with minimal local and systemic complications. CONCLUSION: Periocular injections of methotrexate represent an effective and safe alternative option for the management of active, moderate-to-severe thyroid-associated orbitopathy. Although no serious complications occurred during the 6-month follow-up, the possibility of late complications such as orbital fat atrophy cannot be ruled out.

Eyelid Blink Lagophthalmos and Blinking Velocity Changes After External Transcutaneous Dacrocystorhinostomy: A Prospective Study.

PURPOSE: To investigate the changes in eyelid blinking dynamics after external dacryocystorhinostomy (DCR). DESIGN: Prospective before-and-after study with follow-up. METHODS: Patients undergoing external DCR surgery for primary acquired nasolacrimal duct obstruction were observed using high-speed videography that recorded eyelid blinking of both eyes for a total duration of 4 minutes at a rate of 120 frames per second. These recordings were taken before the surgical procedure, on postoperative day 3, and then at 1 week, 1 month, and 3 months after the DCR surgery. A total of 3 random blinks were selected and isolated from each video recording for data analysis. For each blink, lagophthalmos and eyelid blinking velocity were calculated for the operated eye, and their values were then compared with those calculated for the contralateral, nonoperated eye. RESULTS: Data were obtained for 22 patients. Operated eyes showed large postoperative lagophthalmos on postoperative day 3, with a mean of 56.58% ± 52.63% of the palpebral fissure height. Gradual improvement of the lagophthalmos occurred over the next follow-up visits, and reached a mean of 31.24% ± 36.71% at follow-up visit 3 months postoperatively. The velocity of eyelid blinking showed a significant reduction for the operated eyes, with gradual improvement over 3 months. CONCLUSIONS: Postexternal DCR eyelid blinking changes included significant blink lagophthalmos with decreased velocity of eyelid blinking which gradually improved over the 3-month follow-up period. A longer follow-up period may be required to confirm if eyelid blinking lagophthalmos and velocity will return to baseline levels.

Inactivation strategies for SARS-CoV-2 on surgical masks using light-activated chemical dyes.

BACKGROUND: Methylene blue (MB) and riboflavin (RB) are light-activated dyes with demonstrated antimicrobial activity. They require no specialized equipment, making them attractive for widespread use. Due to COVID-19-related worldwide shortages of surgical masks, simple, safe, and effective decontamination methods for reusing masks have become desirable in clinical and public settings. MATERIAL AND METHODS: We examined the decontamination of SARS-CoV-2 Beta variant on surgical masks and Revolution-Zero Environmentally Sustainable (RZES) reusable masks using these photoactivated dyes. We pre-treated surgical masks with 2 MB concentrations, 2 RB concentrations, and 2 combinations of MB and RB. We also tested 7 MB concentrations on RZES masks. RESULTS: Photoactivated MB consistently inactivated SARS-CoV-2 at >99.9% for concentrations of 2.6 µM or higher within 30 min on RZES masks and 5 µM or higher within 5 min on disposable surgical masks. RB alone showed a lower, yet still significant inactivation (∼93-99%) in these conditions. DISCUSSION: MB represents a cost-effective, rapid, and widely deployable decontamination method for SARS-CoV-2. The simplicity of MB formulation makes it ideal for mask pre-treatment in low-resource settings. CONCLUSIONS: The results demonstrate that MB effectively decontaminates SARS-CoV-2 at concentrations above 5 µM on surgical masks and above 10 µM on RZES masks.

Exploring inactivation of SARS-CoV-2, MERS-CoV, Ebola, Lassa, and Nipah viruses on N95 and KN95 respirator material using photoactivated methylene blue to enable reuse.

BACKGROUND: The COVID-19 pandemic resulted in a worldwide shortage of N95 respirators, prompting the development of decontamination methods to enable limited reuse. Countries lacking reliable supply chains would also benefit from the ability to safely reuse PPE. Methylene blue (MB) is a light-activated dye with demonstrated antimicrobial activity used to sterilize blood plasma. Decontamination of respirators using photoactivated MB requires no specialized equipment, making it attractive for use in the field during outbreaks. METHODS: We examined decontamination of N95 and KN95 respirators using photoactivated MB and 3 variants of SARS-CoV-2, the virus that causes COVID-19; and 4 World Health Organization priority pathogens: Ebola virus, Middle East respiratory syndrome coronavirus, Nipah virus, and Lassa virus. Virus inactivation by pretreating respirator material was also tested. RESULTS: Photoactivated MB inactivated all tested viruses on respirator material, albeit with varying efficiency. Virus applied to respirator material pre-treated with MB was also inactivated, thus MB pretreatment may potentially protect respirator wearers from virus exposure in real-time. CONCLUSIONS: These results demonstrate that photoactivated MB represents a cost-effective, rapid, and widely deployable method to decontaminate N95 respirators for reuse during supply shortages.

Combined large cell neuroendocrine carcinoma and squamous cell carcinoma of the oropharynx: A collision course of tumors.

Combined large cell neuroendocrine carcinoma (LCNEC) and squamous cell carcinoma (SCC) of the H&N are exceptionally rare. We present the case of combined p16 negative SCC and LCNEC of the oropharynx treated with combination chemotherapy. This is the third reported case of combined neuroendocrine carcinoma and SCC of the oropharynx.

Addressing personal protective equipment (PPE) decontamination: Methylene blue and light inactivates severe acute respiratory coronavirus virus 2 (SARS-CoV-2) on N95 respirators and medical masks with maintenance of integrity and fit.

OBJECTIVE: The coronavirus disease 2019 (COVID-19) pandemic has resulted in shortages of personal protective equipment (PPE), underscoring the urgent need for simple, efficient, and inexpensive methods to decontaminate masks and respirators exposed to severe acute respiratory coronavirus virus 2 (SARS-CoV-2). We hypothesized that methylene blue (MB) photochemical treatment, which has various clinical applications, could decontaminate PPE contaminated with coronavirus. DESIGN: The 2 arms of the study included (1) PPE inoculation with coronaviruses followed by MB with light (MBL) decontamination treatment and (2) PPE treatment with MBL for 5 cycles of decontamination to determine maintenance of PPE performance. METHODS: MBL treatment was used to inactivate coronaviruses on 3 N95 filtering facepiece respirator (FFR) and 2 medical mask models. We inoculated FFR and medical mask materials with 3 coronaviruses, including SARS-CoV-2, and we treated them with 10 µM MB and exposed them to 50,000 lux of white light or 12,500 lux of red light for 30 minutes. In parallel, integrity was assessed after 5 cycles of decontamination using multiple US and international test methods, and the process was compared with the FDA-authorized vaporized hydrogen peroxide plus ozone (VHP+O3) decontamination method. RESULTS: Overall, MBL robustly and consistently inactivated all 3 coronaviruses with 99.8% to >99.9% virus inactivation across all FFRs and medical masks tested. FFR and medical mask integrity was maintained after 5 cycles of MBL treatment, whereas 1 FFR model failed after 5 cycles of VHP+O3. CONCLUSIONS: MBL treatment decontaminated respirators and masks by inactivating 3 tested coronaviruses without compromising integrity through 5 cycles of decontamination. MBL decontamination is effective, is low cost, and does not require specialized equipment, making it applicable in low- to high-resource settings.

Short-term effect of weight loss after bariatric surgery on IOP, RNFL thickness, and the optic nerve head blood flow measured by OCTA.

PURPOSE: To study the influence of weight reduction after bariatric surgery on the intraocular pressure (IOP), retinal nerve fiber layer (RNFL) thickness, and blood flow of optic nerve head by optical coherence tomography angiography (OCTA). METHODS: This prospective observational cohort study included 60 obese patients. Body mass index (BMI), IOP, RNFL, and ganglion cell complex (GCC) thickness, rim area, and radial peripapillary capillary (RPC) vessel density were assessed before and 3 months after bariatric surgery. RESULTS: The BMI and the IOP showed significant postoperative reduction to 40.45 ± 4.3 kg/m2 and 14.83 ± 2.5 mmHg while the preoperative results were 51.13 ± 4.83 kg/m2 and 16.95 ± 4.2 mm (p < 0.0001), respectively. No statistically significant change was detected in the RNFL, GCC thickness, rim area, or the RPC vessel density (p > 0.05). No statistically significant correlation was detected between the BMI changes and changes in the IOP, RNFL thickness, rim area, GCC thickness, or RPC vessel density. CONCLUSION: No significant effect of bariatric surgery on the RNFL thickness and the optic nerve head blood flow measured by OCTA despite a significant IOP reduction 3 months post-surgical. OCTA can be a useful tool to assess the short-term influence of significant weight reduction on the retinal microcirculation. SUMMARY: Despite a significant BMI and IOP reduction following bariatric surgery in obese patients, the vascular flow of the ONH, measured by OCTA, and the RNFL thickness were not significantly affected. The former might be attributed to the complex autoregulatory mechanisms related to the ONH and its microcirculation.

Comparison of three surgical techniques for internal angular dermoid cysts: a randomized controlled trial.

PURPOSE: To compare the outcomes of three techniques for removing internal angular dermoid cysts: lid crease, sub-brow, and direct mini-incision. METHODS: In this single-center trial, 47 children with internal angular dermoids were enrolled and randomly assigned to one of three surgical groups: group A, sub-brow, group B, lid crease, and group C, direct mini-incision. Outcome measures were operative time, postoperative scar quality using Stony Brook Scar Evaluation Scale (SBSES), scar visibility, and family satisfaction. RESULTS: In each group, fifteen patients completed follow-up and were analysed. The operation time (median/IQR) in Group C was significantly shorter (10/5 min) compared with group A (25/10 min) and B (35/20 min) (p < 0.001). Group B had the least visible scar at all follow-up visits. Both group B and C showed superior scar quality using SBSES compared with group A at 6 months (p < 0.001). All families in group B (100%) found the scar excellent compared to 11 families in group C (40%) and 6 families in group A (73.3%). Persistent postoperative inflammation was noticed in two patients in group C. No cases of recurrence were recorded. CONCLUSIONS: Both the lid crease and direct mini-incision approaches result in superior scar quality with minimum visibility compared with the sub-brow technique, however, the lid crease technique shows a prolonged operation time particularly for cysts outside the rim.

Endovascular repair and open repair surgery of thoraco-abdominal aortic aneurysms cause drastically different types of spinal cord injury.

Both endovascular repair (EVR) and open repair (OR) surgery of thoraco-abdominal aortic aneurysms cause spinal cord (SC) injury that can lead to paraparesis or paraplegia. It has been assumed that mechanisms responsible for SC damage after EVR are similar to those after OR. This pilot study compared the pathophysiology of SC injury after EVR versus OR using a newly developed EVR dog model. An increasing number of stents similar to those used in patients were inserted in the aorta of three dogs to ensure thoracic or thoracic plus lumbar coverage. The aorta of OR dogs was cross-clamped for 45 min. Behavior assessment demonstrated unique patterns of proprioceptive ataxia and evolving paraparesis in EVR versus irreversible paraplegia in OR. MRI showed posterior signal in lumbar SC after EVR versus central cord edema after OR. Histopathology showed white matter edema in L3-L5 localized to the dorsal column medial lemniscus area associated with loss of myelin basic protein but not neurons after EVR, versus massive neuronal loss in the gray matter in L3-L5 after OR. Metabolome analysis demonstrates a distinctive chemical fingerprint of cellular processes in both interventions. Our results call for the development of new therapeutics tailored to these distinct pathophysiologic findings.

Addressing Personal Protective Equipment (PPE) Decontamination: Methylene Blue and Light Inactivates SARS-CoV-2 on N95 Respirators and Masks with Maintenance of Integrity and Fit

BackgroundThe coronavirus disease 2019 (COVID-19) pandemic has resulted in severe shortages of personal protective equipment (PPE) necessary to protect front-line healthcare personnel. These shortages underscore the urgent need for simple, efficient, and inexpensive methods to decontaminate SARS-CoV-2-exposed PPE enabling safe reuse of masks and respirators. Efficient decontamination must be available not only in low-resourced settings, but also in well-resourced settings affected by PPE shortages. Methylene blue (MB) photochemical treatment, hitherto with many clinical applications including those used to inactivate virus in plasma, presents a novel approach for widely applicable PPE decontamination. Dry heat (DH) treatment is another potential low-cost decontamination method. MethodsMB and light (MBL) and DH treatments were used to inactivate coronavirus on respirator and mask material. We tested three N95 filtering facepiece respirators (FFRs), two medical masks (MMs), and one cloth community mask (CM). FFR/MM/CM materials were inoculated with SARS-CoV-2 (a Betacoronavirus), murine hepatitis virus (MHV) (a Betacoronavirus), or porcine respiratory coronavirus (PRCV) (an Alphacoronavirus), and treated with 10 {micro}M MB followed by 50,000 lux of broad-spectrum light or 12,500 lux of red light for 30 minutes, or with 75{degrees}C DH for 60 minutes. In parallel, we tested respirator and mask integrity using several standard methods and compared to the FDA-authorized vaporized hydrogen peroxide plus ozone (VHP+O3) decontamination method. Intact FFRs/MMs/CM were subjected to five cycles of decontamination (5CD) to assess integrity using International Standardization Organization (ISO), American Society for Testing and Materials (ASTM) International, National Institute for Occupational Safety and Health (NIOSH), and Occupational Safety and Health Administration (OSHA) test methods. FindingsOverall, MBL robustly and consistently inactivated all three coronaviruses with at least a 4-log reduction. DH yielded similar results, with the exception of MHV, which was only reduced by 2-log after treatment. FFR/MM integrity was maintained for 5 cycles of MBL or DH treatment, whereas one FFR failed after 5 cycles of VHP+O3. Baseline performance for the CM was variable, but reduction of integrity was minimal. InterpretationMethylene blue with light and DH treatment decontaminated masks and respirators by inactivating three tested coronaviruses without compromising integrity through 5CD. MBL decontamination of masks is effective, low-cost and does not require specialized equipment, making it applicable in all-resource settings. These attractive features support the utilization and continued development of this novel PPE decontamination method.

Medical Liability in Sinus Surgery: A Westlaw Database Analysis From 2000 to 2017.

BACKGROUND: Medical malpractice occurs when a hospital or health-care provider through negligent act or omission results in an injury to a patient. More than 50% of otolaryngologists have faced at least 1 claim, with rhinology being the most litigated subspecialty. This study aims to analyze medical litigation trends in Rhinology from 2000 to 2017 in the United States. METHODS: The Westlaw database was reviewed from 2000 to 2017. Data were compiled on the demographics of the plaintiffs, procedures, nature of damages, legal allegations, and the use of expert witnesses, physician demographics/practice characteristics, verdicts, indemnities, and county/state of case. RESULTS: There were 75 cases that met inclusion criteria after review of 125 cases. Majority of cases went to trial over settlement (80%) and were found in the Northeast region of the United States (36%). Most common cited legal allegations were improper performance and failure to follow standard of care. The most common nature of injuries were eye injury (29%) and intracranial complications (27%). The highest payouts were for progression of disease followed by intracranial injury. Of the 75 total cases analyzed, 37 (49.3%) used expert witnesses. When an expert witness was used at trial, the verdict statistically favored the defendant (62.5%). CONCLUSIONS: Our analysis reveals the importance of meticulous surgical techniques and thorough preoperative evaluations.

Dataset for the development of a diagnostic schedule for a defective LC-195V5 CNC milling machine at FUTA central workshop.

The dataset represented in this article describe a diagnostic schedule for a defective LC-195V5 CNC milling machine using PERT. The efficiency of the technicians who repaired the CNC machine tools was measured based on fault location within the shortest possible time. A diagnostic schedule was developed which showed the sequential means of troubleshooting within a possible shortest time. Two approaches were employed. Forward Pass (FP), which involved the diagnosis from electrical parts through Computer (CNC) to mechanical components and Backward Pass (BP) which involved the diagnosis from computer component through electrical parts to mechanical parts. Three different levels of expertise (trials) were used for each of the mode of diagnosis and the time to diagnose each component part was recorded. Two separate PERT network diagrams were drawn based on the inter-relationship of the component parts of the machine and their Critical Paths were determined.

Consensus on surgical aspects of managing osteomyelitis in the diabetic foot.

BACKGROUND: The aim of this study was to develop consensus statements that may help share or even establish 'best practices' in the surgical aspects of managing diabetic foot osteomyelitis (DFO) that can be applied in appropriate clinical situations pending the publication of more high-quality data. METHODS: We asked 14 panelists with expertise in DFO management to participate. Delphi methodology was used to develop consensus statements. First, a questionnaire elicited practices and beliefs concerning various aspects of the surgical management of DFO. Thereafter, we constructed 63 statements for analysis and, using a nine-point Likert scale, asked the panelists to indicate the extent to which they agreed or disagreed with the statements. We defined consensus as a mean score of greater than 7.0. RESULTS: The panelists reached consensus on 38 items after three rounds. Among these, seven provide guidance on initial diagnosis of DFO and selection of patients for surgical management. Another 15 statements provide guidance on specific aspects of operative management, including the timing of operations and the type of specimens to be obtained. Ten statements provide guidance on postoperative management, including wound closure and offloading, and six statements summarize the panelists' agreement on general principles for surgical management of DFO. CONCLUSIONS: Consensus statement on the perioperative management of DFO were formed with an expert panel comprised of a variety of surgical specialties. We believe these statements may serve as 'best practice' guidelines until properly performed studies provide more robust evidence to support or refute specific surgical management steps in DFO.

Contribution of Lordotic Correction on C5 Palsy Following Cervical Laminectomy and Fusion.

BACKGROUND: C5 palsy is a well-reported complication of cervical spine surgery. The implication of sagittal cervical alignment parameters and their changes after surgery on the incidence of C5 palsy remains unclear. OBJECTIVE: We review cervical alignment changes in our cases of C5 palsy after cervical laminectomy and fusion. METHODS: Cases of C5 palsy were retrospectively compared with a control group. Preoperative and postoperative upright plain film radiographs were analyzed in blinded fashion. RESULTS: Spine registry analysis identified 148 patients who underwent cervical laminectomy and fusion by the senior author over 5 years. There were 18 (12%) cases complicated by postoperative C5 palsy. Nine of these 18 patients had prerequisite upright films and were compared with a randomly constructed case control group of 20 patients. There were no statistically significant differences between the 2 groups in age, proportion of males, and preoperative Nurick score. Measures of sagittal alignment did not differ significantly between the 2 groups on preoperative and postoperative imaging. When comparing the amount of alignment change between preoperative and postoperative upright imaging, however, patients with C5 palsy had a statistically higher amount of average C4-C5 Cobb angle change (-2.53 vs 0.78°; P = .01). Logistic regression analysis demonstrated that lordotic change in both C4-C5 and C2-C7 Cobb angles were associated with development of palsy. CONCLUSION: Lordotic cervical correction, as measured on upright imaging, was statistically larger in patients who had C5 palsy. The role of deformity correction in C5 palsy deserves further study and may inform intraoperative decision making. ABBREVIATION: CLF, cervical laminectomy and fusion.

A young patient with history of Kawasaki disease presenting with triple vessel disease.

Kawasaki disease is primarily a condition that affects young children and it is associated with cardiac morbidity and mortality. This disease has been known to cause coronary artery aneurysms which occurs as a sequelae of vasculitis. The progression of triple vessel disease in adult which results from cardiac complications from Kawasaki disease is rare. We report a case of a young man with history of Kawasaki disease at infancy presenting with triple vessel disease requiring cardiac bypass surgery at the age of 20 years old.

A low concentration of ethanol impairs learning but not motor and sensory behavior in Drosophila larvae.

Drosophila melanogaster has proven to be a useful model system for the genetic analysis of ethanol-associated behaviors. However, past studies have focused on the response of the adult fly to large, and often sedating, doses of ethanol. The pharmacological effects of low and moderate quantities of ethanol have remained understudied. In this study, we tested the acute effects of low doses of ethanol (∼7 mM internal concentration) on Drosophila larvae. While ethanol did not affect locomotion or the response to an odorant, we observed that ethanol impaired associative olfactory learning when the heat shock unconditioned stimulus (US) intensity was low but not when the heat shock US intensity was high. We determined that the reduction in learning at low US intensity was not a result of ethanol anesthesia since ethanol-treated larvae responded to the heat shock in the same manner as untreated animals. Instead, low doses of ethanol likely impair the neuronal plasticity that underlies olfactory associative learning. This impairment in learning was reversible indicating that exposure to low doses of ethanol does not leave any long lasting behavioral or physiological effects.