Benchmarking the accuracy of structure-based binding affinity predictors on Spike-ACE2 deep mutational interaction set.

Since the start of COVID-19 pandemic, a huge effort has been devoted to understanding the Spike (SARS-CoV-2)-ACE2 recognition mechanism. To this end, two deep mutational scanning studies traced the impact of all possible mutations across receptor binding domain (RBD) of Spike and catalytic domain of human ACE2. By concentrating on the interface mutations of these experimental data, we benchmarked six commonly used structure-based binding affinity predictors (FoldX, EvoEF1, MutaBind2, SSIPe, HADDOCK, and UEP). These predictors were selected based on their user-friendliness, accessibility, and speed. As a result of our benchmarking efforts, we observed that none of the methods could generate a meaningful correlation with the experimental binding data. The best correlation is achieved by FoldX (R = -0.51). When we simplified the prediction problem to a binary classification, that is, whether a mutation is enriching or depleting the binding, we showed that the highest accuracy is achieved by FoldX with a 64% success rate. Surprisingly, on this set, simple energetic scoring functions performed significantly better than the ones using extra evolutionary-based terms, as in Mutabind and SSIPe. Furthermore, we demonstrated that recent AI approaches, mmCSM-PPI and TopNetTree, yielded comparable performances to the force field-based techniques. These observations suggest plenty of room to improve the binding affinity predictors in guessing the variant-induced binding profile changes of a host-pathogen system, such as Spike-ACE2. To aid such improvements we provide our benchmarking data at https://github.com/CSB-KaracaLab/RBD-ACE2-MutBench with the option to visualize our mutant models at https://rbd-ace2-mutbench.github.io/.

The impact of AI-based modeling on the accuracy of protein assembly prediction: Insights from CASP15.

In CASP15, 87 predictors submitted around 11 000 models on 41 assembly targets. The community demonstrated exceptional performance in overall fold and interface contact predictions, achieving an impressive success rate of 90% (compared to 31% in CASP14). This remarkable accomplishment is largely due to the incorporation of DeepMind's AF2-Multimer approach into custom-built prediction pipelines. To evaluate the added value of participating methods, we compared the community models to the baseline AF2-Multimer predictor. In over 1/3 of cases, the community models were superior to the baseline predictor. The main reasons for this improved performance were the use of custom-built multiple sequence alignments, optimized AF2-Multimer sampling, and the manual assembly of AF2-Multimer-built subcomplexes. The best three groups, in order, are Zheng, Venclovas, and Wallner. Zheng and Venclovas reached a 73.2% success rate over all (41) cases, while Wallner attained 69.4% success rate over 36 cases. Nonetheless, challenges remain in predicting structures with weak evolutionary signals, such as nanobody-antigen, antibody-antigen, and viral complexes. Expectedly, modeling large complexes also remains challenging due to their high memory compute demands. In addition to the assembly category, we assessed the accuracy of modeling interdomain interfaces in the tertiary structure prediction targets. Models on seven targets featuring 17 unique interfaces were analyzed. Best predictors achieved a 76.5% success rate, with the UM-TBM group being the leader. In the interdomain category, we observed that the predictors faced challenges, as in the case of the assembly category, when the evolutionary signal for a given domain pair was weak or the structure was large. Overall, CASP15 witnessed unprecedented improvement in interface modeling, reflecting the AI revolution seen in CASP14.

Molecular Mechanism of Nucleosome Recognition by the Pioneer Transcription Factor Sox.

Pioneer transcription factors (PTFs) have the remarkable ability to directly bind to chromatin to stimulate vital cellular processes. In this work, we dissect the universal binding mode of Sox PTF by combining extensive molecular simulations and physiochemistry approaches, along with DNA footprinting techniques. As a result, we show that when Sox consensus DNA is located at the solvent-facing DNA strand, Sox binds to the compact nucleosome without imposing any significant conformational changes. We also reveal that the base-specific Sox:DNA interactions (base reading) and Sox-induced DNA changes (shape reading) are concurrently required for sequence-specific nucleosomal DNA recognition. Among three different nucleosome positions located on the positive DNA arm, a sequence-specific reading mechanism is solely satisfied at the superhelical location 2 (SHL2). While SHL2 acts transparently for solvent-facing Sox binding, among the other two positions, SHL4 permits only shape reading. The final position, SHL0 (dyad), on the other hand, allows no reading mechanism. These findings demonstrate that Sox-based nucleosome recognition is essentially guided by intrinsic nucleosome properties, permitting varying degrees of DNA recognition.

Assessment of the CASP14 assembly predictions.

In CASP14, 39 research groups submitted more than 2500 3D models on 22 protein complexes. In general, the community performed well in predicting the fold of the assemblies (for 80% of the targets), although it faced significant challenges in reproducing the native contacts. This is especially the case for the complexes without whole-assembly templates. The leading predictor, BAKER-experimental, used a methodology combining classical techniques (template-based modeling, protein docking) with deep learning-based contact predictions and a fold-and-dock approach. The Venclovas team achieved the runner-up position with template-based modeling and docking. By analyzing the target interfaces, we showed that the complexes with depleted charged contacts or dominating hydrophobic interactions were the most challenging ones to predict. We also demonstrated that if AlphaFold2 predictions were at hand, the interface prediction challenge could be alleviated for most of the targets. All in all, it is evident that new approaches are needed for the accurate prediction of assemblies, which undoubtedly will expand on the significant improvements in the tertiary structure prediction field.

Comparison of breast cancer patients who underwent partial mastectomy (PM) with mini latissimus dorsi flap (MLDF) and subcutaneous mastectomy with implant (M + I) regarding quality of life (QOL), cosmetic outcome and survival rates.

PURPOSE: The latissimus dorsi muscle has long been used in breast cancer (BC) patients for reconstruction. This study aimed to compare early stage BC patients who had partial mastectomy (PM) with mini latissimus dorsi flap (MLDF) and subcutaneous mastectomy with implant (MI) with respect to quality of life (QoL), cosmetic outcome (CO), and survival rates. PATIENTS AND METHODS: The data of patients who underwent PM + MLDF (Group 1) and M + I (Group 2) between January 2010 and January 2018 were evaluated. Both groups were compared in terms of demographics, clinical and pathological characteristics, surgical morbidity, survival, quality of life, and cosmetic results. The EORTC-QLQ C30 and EORTC-QLO BR23 questionnaires and the Japanese Breast Cancer Society (JBCS) Cosmetic Evaluation Scale were used to assess the quality of life and the cosmetic outcome, respectively. RESULTS: A total of 317 patients were included in the study, 242 (76.3%) of them in group 1 and 75 (23.6%) of them in group 2. Median follow-up time was 56 (14-116) months. There were no differences identified between the groups in terms of tumor histology, hormonal receptors and HER-2 positivity, surgical morbidity, and 5-year overall and disease-free survival. Group 2 patients were significantly younger than group 1 (p = 0.003). The multifocality/multicentricity rate was higher in group 2 (p ≤ 0.001), whereas tumor size (p = 0.009), body mass index (BMI, p = 0.006), histological grade (p ≤ 0.001), lymph node positivity (p = 0.002), axillary lymph node dissection (ALND) rate (p = 0.005), and presence of lympho-vascular invasion (LVI, p = 0.013) were significantly higher in group 1. When the quality of life was assessed by using the EORTC QLQ C30 and BR23 questionnaires, it was seen that the body image perception (p < 0.001) and nausea/vomiting score (p = 0.024) were significantly better in PM + MLDF group whereas physical function score was significantly better in M + I group (p = 0.012). When both groups were examined in terms of cosmesis with JBCS Cosmetic Evaluation Scale, good cosmetic evaluation score was significantly higher in patients in MLDF group (p = 0.01). DISCUSSION: The results of this study indicate that in comparison to M + I procedure, the PM + MLDF procedure provides significantly superior results in terms of body image and cosmetic result with similar morbidity and oncologic outcomes. In selected patients with small breasts and a high tumor/breast ratio, PM + MLDF may be an alternative to subcutaneous mastectomy and implant.

Post-mastectomy radiation therapy after breast reconstruction: from historic dogmas to practical expert agreements based on a large literature review of surgical and radiation therapy considerations.

Breast reconstruction (BR) after mastectomy is important to consider for a woman's body image enhancement and psychological well-being. Although post-mastectomy radiation (PMRT) significantly improves the outcome of patients with high-risk breast cancer (BC), PMRT after BR may affect cosmetic outcomes and may compromise the original goal of improving quality of life (QoL). With the lack of practical guidelines, it seems essential to work on a consensus and provide some "expert agreements" to offer patients the best option for PMRT after BR. We report a global "expert agreement" that results from a critical review of the literature on BR and PMRT during the 6th international multidisciplinary breast conference in March 2023.

The Impact of AI-Based Modeling on the Accuracy of Protein Assembly Prediction: Insights from CASP15.

In CASP15, 87 predictors submitted around 11,000 models on 41 assembly targets. The community demonstrated exceptional performance in overall fold and interface contact prediction, achieving an impressive success rate of 90% (compared to 31% in CASP14). This remarkable accomplishment is largely due to the incorporation of DeepMind's AF2-Multimer approach into custom-built prediction pipelines. To evaluate the added value of participating methods, we compared the community models to the baseline AF2-Multimer predictor. In over 1/3 of cases the community models were superior to the baseline predictor. The main reasons for this improved performance were the use of custom-built multiple sequence alignments, optimized AF2-Multimer sampling, and the manual assembly of AF2-Multimer-built subcomplexes. The best three groups, in order, are Zheng, Venclovas and Wallner. Zheng and Venclovas reached a 73.2% success rate over all (41) cases, while Wallner attained 69.4% success rate over 36 cases. Nonetheless, challenges remain in predicting structures with weak evolutionary signals, such as nanobody-antigen, antibody-antigen, and viral complexes. Expectedly, modeling large complexes remains also challenging due to their high memory compute demands. In addition to the assembly category, we assessed the accuracy of modeling interdomain interfaces in the tertiary structure prediction targets. Models on seven targets featuring 17 unique interfaces were analyzed. Best predictors achieved the 76.5% success rate, with the UM-TBM group being the leader. In the interdomain category, we observed that the predictors faced challenges, as in the case of the assembly category, when the evolutionary signal for a given domain pair was weak or the structure was large. Overall, CASP15 witnessed unprecedented improvement in interface modeling, reflecting the AI revolution seen in CASP14.

Validation of bioelectrical impedance analysis in the evaluation of body composition in patients with breast cancer.

BACKGROUND: The evaluation of body composition is an essential parameter for preventing obesity and sarcopenic obesity, which are prognostic factors in breast cancer. This study aims to validate the bioelectrical impedance analysis (BIA) of women who are breast cancer survivors by using the dual-energy x-ray absorptiometry (DXA) measurement method. METHODS: This validation study included 104 women without metastasis between 32 and 72 years old (mean 47.03 ± 8.59) whose treatment was completed 6 months prior. Body composition analysis was performed sequentially using both measurements and when participants were hungry. RESULTS: Meaningful differences were found in fat-free mass (FFM) (BIA: 46.57 ± 5.54 kg; DXA: 41.06 ± 5.11 kg), body fat percentage (%BF) (BIA: 34.28% ± 6.24%; DXA: 43.91% ± 5.58%), body fat mass (FM) (BIA: 25.37 ± 8.84 kg; DXA: 31.24 ± 9.09 kg), and lean soft tissue mass (LSTM) (BIA: 4.42 ± 5.66 kg; DXA: 38.75 ± 4.98 kg) (P < 0.001). Powerful associations for body FM and strong associations for other parameters were seen. A constant and/or proportional error was found between the two devices within the direction of strong and solid components. Compared with DXA, the BIA measurement gives a lower estimate of %BF and FM and a higher estimate of LSTM and FFM. CONCLUSIONS: By the mathematical relationship between the two measurement methods, it seems possible to adapt the body composition parameters obtained from BIA of patients with breast cancer to DXA results. In the future, there will be a need to evaluate these two devices with more extensive studies.

Engineering Vacancies for the Creation of Antisite Defects in Chemical Vapor Deposition Grown Monolayer MoS2 and WS2 via Proton Irradiation.

It is critical to understand the laws of quantum mechanics in transformative technologies for computation and quantum information science applications to enable the ongoing second quantum revolution calls. Recently, spin qubits based on point defects have gained great attention, since these qubits can be initiated, selectively controlled, and read out with high precision at ambient temperature. The major challenge in these systems is controllably generating multiqubit systems while properly coupling the defects. To address this issue, we began by tackling the engineering challenges these systems present and understanding the fundamentals of defects. In this regard, we controllably generate defects in MoS2 and WS2 monolayers and tune their physicochemical properties via proton irradiation. We quantitatively discovered that the proton energy could modulate the defects' density and nature; higher defect densities were seen with lower proton irradiation energies. Three distinct defect types were observed: vacancies, antisites, and adatoms. In particular, the creation and manipulation of antisite defects provides an alternative way to create and pattern spin qubits based on point defects. Our results demonstrate that altering the particle irradiation energy can regulate the formation of defects, which can be utilized to modify the properties of 2D materials and create reliable electronic devices.

Does partial expander deflation exacerbate the adverse effects of radiotherapy in two-stage breast reconstruction?

BACKGROUND: The optimum protocol for expander volume adjustment with respect to the timing and application of radiotherapy remains controversial. METHODS: Eighteen New Zealand rabbits were divided into three groups. Metallic port integrated anatomic breast expanders of 250 cc were implanted on the back of each animal and controlled expansion was performed. Group I underwent radiotherapy with full expanders while in Group II, expanders were partially deflated immediately prior to radiotherapy. Control group did not receive radiotherapy.The changes in blood flow at different volume adjustments were investigated in Group II by laser Doppler flowmetry. Variations in the histopathologic properties of the irradiated tissues including the skin, capsule and the pocket floor, were compared in the biopsy specimens taken from different locations in each group. RESULTS: A significant increase in skin blood flow was detected in Group II with partial expander deflation. Overall, histopathologic exam revealed aggravated findings of chronic radiodermatitis (epidermal atrophy, dermal inflammation and fibrosis, neovascularisation and vascular changes as well as increased capsule thickness) especially around the lower expander pole, in Group II. CONCLUSIONS: Expander deflation immediately prior to radiotherapy, may augment the adverse effects, especially in the lower expander pole, possibly via enhanced radiosensitization due to a relative increase in the blood flow and tissue oxygenation.

Major donor area complication after a mandibular reconstruction with an osseous fibular free flap: pseudo-compartment syndrome.

The popularity of the fibular free flap in mandibular reconstructions is persisting, and major donor area complications rarely occur after fibular free flap operations. Still, we have observed a pseudo-compartment syndrome in a 52-year-old patient on the 12th postoperative day after a mandibular reconstruction with a fibular free flap. When an obstruction in the deep venous system (deep vein thrombosis) was observed in the Doppler ultrasound-guided imaging, the patient has been taken to the operating room for an emergency surgery and the donor area has been completely reopened (in the manner of a fasciotomy). After this procedure, the circulation in the foot appeared to return to normal. The exposed muscles of the patient, who was started on a low-molecular-weight heparin treatment for the deep vein thrombosis, have been closed with skin grafts on the 10th day. No functional loss was observed during the 2-month follow-up period.

Quadruple salivary duct diversion for drooling in cerebral palsy.

Drooling complicates many neurologic disorders including cerebral palsy. It is socially debilitating for the patient and very tedious for the caregiver. Surgical treatment consists mainly of ablative (excision/ligation) or physiological (diversion) methods; combined techniques have also been proposed. We have applied bilateral diversion of both submandibular and parotid ducts in 12 cerebral palsy patients (age range, 7-15 years). Preoperative drooling severity was grade 4/5 in 10 cases and grade 5/5 in 2 of the cases. All patients underwent physiotherapy for a minimum of 6 months and were consulted with a dentist, otolaryngologist, and a speech therapist before surgery. No bleeding, hematoma, or infection has been observed in any of the patients. Two patients had early postoperative tongue edema that regressed with conservative treatment. All patients except one regressed to grade 2/5 drooling by the first postoperative month. In 1 patient who had previously been classified as grade 5/5, surgery provided limited improvement with only 1 grade of step-down. Satisfactory results for the patients and their families could be achieved and sustained for a median 18 months (7-20 months) of follow-up. In conclusion, the quadruple duct diversion method is an effective physiological surgical method in the control of drooling in cerebral palsy.

Novel biallelic variants affecting the OTU domain of the gene OTUD6B associate with severe intellectual disability syndrome and molecular dynamics simulations.

Intellectual developmental disorder with dysmorphic facies, seizures, and distal limb anomalies (IDDFSDA) is an autosomal recessive multisystem disorder caused by compound heterozygous or homozygous variants in the gene OTUD6B. Herein, we describe novel pathogenic compound heterozygous variants in OTUD6B identified via whole-exome sequencing in an index case exhibited the severe IDDFSDA phenotype. The potential pathogenicity of the novel frameshift and missense variants in the index case was investigated using in silico tools. The truncating frameshift variant in one allele was predicted to undergo degradation via nonsense-mediated decay of the mRNA molecule. To predict the severity of the damage to the protein caused by the missense variant in the other allele and its effects on phenotypic severity was further investigated together with a previously reported first homozygous missense variant in the same domain in another patient with a less severe IDDFSDA phenotype using structural modeling and molecular dynamics (MD) simulations for the first time. Based on these analyzes, it is anticipated that Tyr216Cys in the earlier reported case with less severe IDDFSDA will lead to localized destabilization, whereas Ile274Arg in the presented index case with the severe IDDFSDA phenotype will lead to significant distortion in the overall fold of OTUD6B. Our findings suggest that compound LOF and ultrarare missense variants may be contribute to the underlying variability expressivity associated with this disorder. In conclusion, our findings support that the clinical severity could be related with the predicted functional severity of the variations in OTUD6B. However, additional functional studies are required.

VARS1 mutations associated with neurodevelopmental disorder are located on a short amino acid stretch of the anticodon-binding domain.

Majority of 37 human aminoacyl tRNA synthetases have been incriminated in diverse, mostly recessive, genetic diseases. In accordance with this, we uncovered a novel homozygous valyl-tRNA synthetase 1 (VARS1) gene variant, leading to p.T1068M mutation. As in the previously reported VARS1 mutations, the affected individual harboring p.T1068M was experiencing a neurodevelopmental disorder with intractable seizures, psychomotor retardation, and microcephaly. To link this phenotypic outcome with the observed genotype, we structurally modeled human VARS1 and interpreted p.T1068M within the spatial distribution of previously reported VARS1 variants. As a result, we uncovered that p.T1068M is clustered with three other pathogenic mutations in a 15 amino acid long stretch of the VARS1 anticodon-binding domain. While forming a helix-turn-helix motif within the anticodon-binding domain, this stretch harbors one-fourth of the reported VARS1 mutations. Here, we propose that these clustered mutations can destabilize the interactions between the anticodon-binding and the tRNA synthetase domains and thus hindering the optimal enzymatic activity of VARS1. We expect that the depiction of this mutation cluster will pave the way for the development of drugs, capable of alleviating the functional impact of these mutations.

Does hyperbaric oxygen administration before or after irradiation decrease side effects of irradiation on implant sites?

BACKGROUND: One of the main limitations of implant-based breast reconstruction is the high rate of complications such as capsular contracture and poor aesthetic outcome, due to adjuvant radiotherapy. Hyperbaric oxygen treatment (HBOT) has been used to assist wound healing in the prevention and treatment of the side effects of irradiation. We aimed to investigate this effect of HBOT on the capsule reaction and skin, applied before and after irradiation, following the placement of an implant under the dorsal skin of the rat. METHODS: Fifteen Wistar rats were randomly divided into 3 groups. A 18-mL smooth testicular implant was introduced into a subcutaneous pocket located on the dorsum of each rat. A single dose of 17-Gy irradiation was given to the implanted area of each rat at the third week. HBOT which lasted 3 weeks was administered to group I before irradiation, group II after irradiation. The control group did not receive HBOT. All of the rats were killed at the ninth week (6 weeks after irradiation). The dorsal skin with the capsule overlying the implant were excised for histopathological processing. The thickness of the capsule reaction of each group was evaluated statistically. RESULTS: Our histopathological examination revealed changes due to radiation in the control group. Many of these findings were found to be more subtle in group I and nearly absent in the group II. There was not any statistical difference between the thickness of the capsule reactions of the control group and group I, or group I and group II, but the capsular thickness of the control group was statistically higher than group II. CONCLUSION: It can be predicted that the use of HBOT following irradiation is an effective tool to reduce the capsule reaction of the implanted area and the tissue damage seen in radiodermatitis.

Favorable Outcome with Close Margins in Patients Undergoing Nipple/Skin Sparing Mastectomy with Immediate Breast Reconstruction: 5-year Follow-up.

BACKGROUND: Implant-based breast reconstruction after mastectomy has recently been reported to be the preferred type of surgery among breast-specific surgeons and plastic surgeons. AIMS: To explore the significant clinicopathological factors associated with long-term outcome related to local recurrences of the nipple among patients who underwent immediate breast reconstruction with tissue expander or implant after mastectomy. STUDY DESIGN: Retrospective cohort. METHODS: From January 2007 to January 2013, 51 breast cancer patients who underwent immediate breast reconstruction with tissue expander or implant were retrospectively analysed. Patients' demographic data, clinicopathological characteristics, and clinical outcome by disease-free survival and disease-specific survival analyses were determined. RESULTS: The median follow-up was 64 (31-114) months. Of the 57 mastectomies, 41 were skin sparing mastectomy (72%) and 16 were nipple-areola sparing mastectomy (28%). Immediate breast reconstruction surgery included tissue expander (n=46, 81%) or implant (n=11, 19%) placement. The molecular subgroups of 47 invasive cancers were as follows: luminal A (n=23, 49%), luminal B (n=16, 34%), non-luminal HER2 (n=5, 10.6), triple negative breast cancer (n=3, 6.4%). The 5-years disease-specific survival, disease-free survival, and locoregional recurrence-free survival rates were 96.8%, 90%, and 97.6% respectively. Patients with luminal A cancer were found to have an improved 5-year disease-free survival time than other (luminal A; 100% vs. non-luminal A; 78%; p=0.028). Of the 14 nipple-areola sparing mastectomy, 13 had a close median tumour distance to nipple-areola complex (<20 mm) with a 5-year locoregional recurrence free survival of 100%. CONCLUSION: Immediate breast reconstruction with implant or tissue expander can be safely applied in patients undergoing skin sparing mastectomy or nipple-areola sparing mastectomy. Patients with luminal-A type show the most favourable outcome. During the 5-year follow-up period, patients even with close margins (<20 mm) to nipple-areola complex with nipple-areola sparing mastectomy have excellent locoregional and overall survival when treated by contemporary multidisciplinary oncological management.

Investigation of novel pharmacological chaperones for Gaucher Disease.

Beta-Glucocerebrosidase (GBA) is a lysosomal protein that is responsible for the hydrolysis of glycosylceramide into glucose and ceramide. Mutations in GBA lead to the accumulation of glycosylceramide in the lysosome causing an enlargement of the spleen and the liver and skeletal deformations. This disease is called Gaucher Disease. Enzyme replacement therapies and substrate reduction methods that are used to treat Gaucher Disease fail when the disease is neuropathic because they fail to pass the blood brain barrier. In this work, QSAR, virtual screening, docking and molecular dynamics simulations were performed to obtain a set of compounds that might be pharmacological chaperones for GBA. ZINC Database was screened using ligand-based and structure-based pharmacophore hypotheses. After docking of these molecules and filtration based on druglikeness, top ranking ligands were identified and their binding stabilities were examined using MD simulations. As a result, seven new compounds that can potentially cross the blood brain barrier were proposed as GBA inhibitors. Three of the seven compounds have a tricyclic pyrido-thieno-pyrimidine scaffold and one has the dioxino quinolone scaffold. Derivatives of these scaffolds have been reported as antiallergic agents, antibiotic and anticancer compounds. These results offer a new approach for the development of new drugs against neuropathic Gaucher Disease Type 2 and Type 3.

Ultrasound-Guided Bilateral Thoracic Paravertebral Blocks as an Adjunct to General Anesthesia in Patients Undergoing Reduction Mammaplasty: A Historical Cohort Study.

BACKGROUND: This study investigates whether ultrasound-guided thoracic paravertebral blocks would improve postoperative analgesia in patients undergoing bilateral reduction mammaplasty. METHODS: After obtaining ethics committee approval, data of 70 patients who underwent bilateral reduction mammaplasty were reviewed. Sixty-four patients' data were evaluable; 30 were in the general anesthesia group and 34 were in the thoracic paravertebral block group. Data such as time to first pain, intraoperative fentanyl requirement, postoperative numeric rating scale scores, number of patients who required tramadol in the postoperative care unit, and rescue analgesic consumption through the first 2 postoperative days were analyzed. RESULTS: Time to first pain was 311 minutes (range, 0 to 1605 minutes) and 20 minutes (range, 0 to 120 minutes) in the thoracic paravertebral block and general anesthesia groups, respectively (p < 0.001). Fentanyl requirement was 52.94 ± 11.94 µg and 115 ± 29.79 µg in the thoracic paravertebral block and general anesthesia groups, respectively (p < 0.001). Numeric rating scale scores were lower in the thoracic paravertebral block group through the first 2 postoperative hours (p < 0.001), and only two of 34 patients required tramadol in the postoperative care unit (p < 0.001). On postoperative day 1, both metamizole sodium (p < 0.001) and paracetamol (p = 0.018), and on day 2, only metamizole sodium (p < 0.001) consumption was lower in the thoracic paravertebral block group. CONCLUSION: Adding ultrasound-guided thoracic paravertebral blocks to general anesthesia postponed time to first pain and reduced analgesic consumption in patients undergoing bilateral reduction mammaplasty. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.