Biochemistry, Biophysics, and Structural Biology Commons^™

Genetic Study Of Alkane Production And Oxic Nitrogen Fixation In Anabaena Sp. Pcc 7120, Jaimie L. Gibbons

Electronic Theses and Dissertations

Anabaena sp. PCC 7120 is a filamentous, nitrogen-fixing cyanobacterium that uses spatial separation to perform photosynthesis and nitrogen fixation simultaneously. Under fixed nitrogen limiting conditions, Anabaena 7120 forms specialized cells, called heterocysts, to fix nitrogen. In this research, I sought to add to the knowledge surrounding the process of heterocystous nitrogen fixation in Anabaena 7120. Cyanobacteria universally produce alkanes, which have been suggested to play a role in helping the organism adapt to abiotic stress, such as diazotrophic conditions. In my first study, I sought to identify the genes required for production of the hydrocarbon heptadecane (C17H36). Through using a …

The Effects Of Induced Polycystic Ovary Syndrome In Nag-1 Transgenic Mice, Nicholas Werner

All Master's Theses

Polycystic ovary syndrome (PCOS) is the leading cause of infertility among women in the US and the most common endocrine disorder among women. PCOS is characterized by cystic ovaries, hyperandrogenism (heightened levels of male sex hormones), altered menstrual cycles and various metabolic dysfunctions. The metabolic symptoms associated with PCOS are difficult to treat, as they are a result of hormonal imbalances, rather than diet. The human Non-Steroidal Anti-Inflammatory Drug Activated Gene (NAG-1) been shown to prevent diet-induced metabolic disorders and weight gain in mice. We hypothesized that the expression of NAG-1 may also prevent hormonal-induced metabolic disorders. To test this …

Insights Into The Structure, Pharmacology, And Evolution Of The Glycine Transporter 2, Ashley Bryan Lopez

Open Access Theses & Dissertations

The balance between neuronal excitation and inhibition in the central nervous system is vital for survival. Overexcitation can be toxic and lead to certain manias or even death. On the other hand, extremely low levels of inhibition cause hyperekplexia, pain, and even forms of autism. Neuronal inhibition is, for the most part, achieved by two neurotransmitters, GABA and glycine. Levels of both neurotransmitters in the synaptic cleft are meticulously regulated by the GABA and glycine transporters, respectively, which belong to the solute carrier 6 (SLC6) family of neurotransmitter transporters and share structural similarities with other family members. In Chapter 1, …

Molecular And Functional Characterization Of Α-Galactosyl Epitopes In Trypanosoma Cruzi, Uriel Ortega Rodriguez

Open Access Theses & Dissertations

Trypanosoma cruzi, the causative agent of Chagas disease (CD) currently affects 6-7 million people across the world. Currently, only two drugs, benznidazole and nifurtimox, are available for treatment of CD and they are highly toxic and less effective in the chronic stage of the disease. Specific biomarkers for diagnosis and follow-up of treatment do not exist in the clinical settings. following chemotherapy, patients take approximately 10-20 years to exhibit negative seroconversion with the conventional serology assays. Moreover, there is no vaccine available to prevent or treat CD. T. cruzi contains a complex cell surface consisting of several classes of glycoconjugates …

Expression, Purification, And Characterization Of Recombinant Human Npas2, Brenda Moreno

Open Access Theses & Dissertations

Many living organisms have biological clocks known as circadian rhythms that control various physiological and behavioral processes, tailored with the day and night. At the cellular level, the circadian clock drives daily rhythms with a transcriptional-translational feedback loop (TTFL) established by multiple transcription factors and genes under their regulation. Circadian Locomotor Output Cycles Kaput (CLOCK) and Brain and Muscle ARNT-like protein 1 (BMAL1) are two of those transcription factors, initiating the TTFL by forming a heterodimeric complex that bind to DNA promoters. Neuronal PAS domain protein 2 (NPAS2) is a functional analog to CLOCK. Less knowledge about NPAS2, in contrast …

Termination-Independent Role Of Rat1 In Cotranscriptional Splicing In Budding Yeast, Zuzer Hakimuddin Dhoondia

Wayne State University Dissertations

Rat1 is a 5′→3′ exoribonuclease in budding yeast belonging to the XRN-family of nucleases. It is a highly conserved protein with homologs being present in fission yeast, flies, worms, mice and humans. Rat1 and its homolog in metazoan have been shown to function in multiple facets of RNA metabolism. In this study, we report a novel role of Rat1 in splicing of pre-mRNA in budding yeast. In the absence of the functional Rat1 in the nucleus, an increase in the level of unspliced transcripts was observed in yeast cells. Strand-specific TRO analysis revealed that the accumulation of unspliced transcripts upon …

Novel Insights Into The Critical Role Of Cardiolipin In Cellular Metabolism And Mitochondrial Physiology, Jiajia Ji

Wayne State University Dissertations

Cardiolipin (CL) is the signature phospholipid of mitochondria. CL and its remodeling exert critical roles in biological processes both inside and outside of mitochondria. CL abnormalities have been associated with various mitochondrial disorders and aging. Understanding the role of CL in mitochondrial physiology and cellular metabolism could provide valuable insights into cell biology and human health. Several metabolic alterations have been reported in CL-deficient cells, including accumulated lactate, decreased PDH activity, and decreased TCA cycle function. This dissertation connected these findings by showing abnormal NAD+ metabolism in various models lacking CL. Importantly, it shows that NAD+ supplementation improves mitochondrial function …

Non-Invasive Method For Leptin Supplementation In Zebrafish (Danio Rerio), Regan Mcnamara

Williams Honors College, Honors Research Projects

I tested the hypothesis that recombinant leptin protein can be introduced to zebrafish in vivo through non-invasive soaking in a solution containing the protein. One way to study various molecules’ effects in vivo is through intraperitoneal or intracerebroventricular injections during the embryonic or larval stage, which is invasive, difficult to administer, and can have a high mortality rate. 48 hours post fertilization (hpf) zebrafish were soaked in a His-tagged recombinant leptin protein solution at 10 nM and 100 nM concentrations (produced by Genscript). After soaking, zebrafish larvae were washed extensively to remove all recombinant protein on their exterior before homogenization. …

Development Of A Quantitative Pcr (Qpcr) Based Method For Studying Temporal Dna Degradation In Waterlogged Bone, Isis Thornton

Master of Science in Forensic Science Directed Research Projects

Human activities are often centered around the presence of water, thus it is not surprising that there are many water-related human deaths. Accumulated degree days (ADD), and other aquatic variables may affect DNA retrieval from waterlogged bone. Calcium and collagen in bone can inhibit the PCR necessary to produce an STR profile; the current solution is a time-consuming organic extraction. While there are examples of research on DNA degradation in terrestrial bone over time, there has been little work done on submerged bone samples and they are usually limited to case studies. The major aim of this study was to …

Meta-Analysis Comparing Watchmantm And Amplatzer Devices For Stroke Prevention In Atrial Fibrillation, Indranill Basu Ray, Dibbendhu Khanra, Sumit Shah, Sudhanva Char, Xiaoming Jia, Wilson Lam, Nilesh Mathuria, Mehdi Razavi, Bhavna Jain, Dhanunjaya Lakkireddy, Saibal Kar, Andrea Natale, Adedayo Adeboye, John Lynn Jefferies, Sripal Bangalore, Samuel Asirvatham, Mohammad Saeed

Faculty, Staff and Students Publications

Background: For patients with atrial fibrillation who are at high risk for bleeding or who cannot tolerate oral anticoagulation, left atrial appendage (LAA) closure represents an alternative therapy for reducing risk for thromboembolic events.

Objectives: To compare the efficacy and safety of the Amplatzer and Watchman^TM LAA closure devices.

Methods: A meta-analysis was performed of studies comparing the safety and efficacy outcomes of the two devices. The Newcastle-Ottawa Scale was used to appraise study quality.

Results: Six studies encompassing 614 patients were included in the meta-analysis. Overall event rates were low for both devices. No significant differences between the …

Pregnancy And Lactation In A 67-Year-Old Elderly Gravida Following Donor Oocyte, Leila Magistrado, Mary C Tolcher, Anju Suhag, Sonal Zambare, Kjersti M Aagaard

Faculty, Staff and Students Publications

There is limited data on the anticipated perinatal course among gravidae in their sixth and seventh decades. Our objective was to describe the relatively uncomplicated prenatal, intrapartum, and postpartum course of a 67-year-old essential primigravida. Briefly, our patient conceived a singleton pregnancy via IVF with donor oocytes, then presented at 13 6/7 weeks of gestation to initiate prenatal care. Her medical history was significant for chronic hypertension, hyperlipidemia, and obesity. Her cardiac function was monitored throughout pregnancy, and she delivered at 36 1/7 weeks by cesarean for a decline in left ventricular function with mitral regurgitation. Her intrapartum and postpartum …

The Exploration Of Nanotoxicological Copper And Interspecific Saccharomyces Hybrids, Matthew Joseph Winans Phd

Graduate Theses, Dissertations, and Problem Reports (ETD)

Nanotechnology takes advantage of cellular biology’s natural nanoscale operations by interacting with biomolecules differently than soluble or bulk materials, often altering normal cellular processes such as metabolism or growth. To gain a better understanding of how copper nanoparticles hybridized on cellulose fibers called carboxymethyl cellulose (CMC) affected growth of Saccharomyces cerevisiae, the mechanisms of toxicity were explored. Multiple methodologies covering genetics, proteomics, metallomics, and metabolomics were used during this investigation. The work that lead to this dissertation discovered that these cellulosic copper nanoparticles had a unique toxicity compared to copper. Further investigation suggested a possible ionic or molecular mimicry …

Reprograming Neuronal Cells By Overexpression Of Fibroblast-Specific Transcription Factors, Abdulmohsen Alanazi

Masters Theses

In mammals, a complex system of regulatory signals distinguishes tissues, structures and functions. Combinations of transcription factors and co-factors regulate activation and repression of genes that result in cellular differentiation. Whole genome arrays allow the monitoring of genomic expression in specific tissues. Fibroblast microarray studies have shown candidate genes that may be involved in fibroblast identification, including genes that express transcription factors Prrx1, Snai2 and Twist1. A previous study showed that the Prrx1 and Snai2 could reactivate a fibroblast phenotype in hybrid cells that had lost fibroblast identity. Furthermore, overexpression of these factors in liver-derived cells strongly repressed liver gene …

Seasonal Variation In Mitochondrial Bioenergetics Of The Bluegill Sunfish, Lepomis Macrochirus, From A Shallow Midwest River, Derick Isaac Lamptey

Masters Theses

As average global temperature increase, the frequency and magnitude of extreme temperatures in shallow aquatic ecosystems are more ubiquitous. In order to understand how these changing thermal regimes affect aquatic ectotherms, it is essential to develop studies evaluating the response of ectotherms to seasonal fluctuating thermal regimes. Previous studies on fluctuating temperature regimes have reported an increased physiological stress leading to morphological, behavioral and biochemical adaptations. From the latter, the adaptive capacity and seasonal performance associated with optimal function of the oxidative phosphorylation system (OXPHOS) are key for species persistence. However, studies on this matter are scarce. This study explores …

Proteomic Analysis Of Fetal Rat Neural Stem Cells After Treatment With Hericium Erinaceus, Bright Adam Test

University of the Pacific Theses and Dissertations

The fungus, Hericium erinaceus, has outstanding chemical properties, displaying health benefits in digestive, hepatic, and nervous tissues. Its ease of accessibility and use makes it one of the most common substances used for treatment in Eastern medicine. More and more recent research is confirming the incredible health benefits of this fungus, especially the impact that is seen on nervous tissue growth and recovery post-treatment. Such neurite outgrowth and myelin sheath regeneration could illustrate the beginning of the cure to lifelong neurodegenerative diseases such as Multiple Sclerosis. In this first-of-its-kind study, we cultured and differentiated fetal rat neural stem cells while …

The Vimentin Rod Domain Blocks P-Selectin-P-Selectin Glycoprotein Ligand 1 Interactions To Attenuate Leukocyte Adhesion To Inflamed Endothelium, Fong Wilson Lam, Cameron August Brown, Christian Valladolid, Dabel Cynthia Emebo, Timothy Gerald Palzkill, Miguel Angel Cruz

Faculty, Staff and Students Publications

Acute inflammation begins with leukocyte P-selectin glycoprotein ligand-1 (PSGL-1) binding to P-selectin on inflamed endothelium and platelets. In pathologic conditions, this process may contribute to secondary organ damage, like sepsis-induced liver injury. Therefore, developing novel therapies to attenuate inflammation may be beneficial. We previously reported that recombinant human vimentin (rhVim) binds P-selectin to block leukocyte adhesion to endothelium and platelets. In this study, we used SPOT-peptide arrays to identify the rod domain as the active region within rhVim that interacts with P-selectin. Indeed, recombinant human rod domain of vimentin (rhRod) binds to P-selectin with high affinity, with in silico modeling …

Can The Carbon And Nitrogen Isotope Values Of Offspring Be Used As A Proxy For Their Mother's Diet? Using Foetal Physiology To Interpret Bulk Tissue And Amino Acid Δ15N Values, Nico Lübcker, John P. Whiteman, Seth D. Newsome, Robert P. Millar, P.J. Nico De Bruyn

Biological Sciences Faculty Publications

The measurement of bulk tissue nitrogen (δ¹⁵N) and carbon isotope values (δ¹³C) chronologically along biologically inert tissues sampled from offspring can provide a longitudinal record of their mothers' foraging habits. This study tested the important assumption that mother-offspring stable isotope values are positively and linearly correlated. In addition, any change in the mother-offspring bulk tissues and individual amino acids that occurred during gestation was investigated. Whiskers sampled from southern elephant seal pups (Mirounga leonina) and temporally overlapping whiskers from their mothers were analyzed. This included n = 1895 chronologically subsampled whisker segments for bulk …

Single-Nuclei Rna-Seq On Human Retinal Tissue Provides Improved Transcriptome Profiling, Qingnan Liang, Rachayata Dharmat, Leah Owen, Akbar Shakoor, Yumei Li, Sangbae Kim, Albert Vitale, Ivana Kim, Denise Morgan, Shaoheng Liang, Nathaniel Wu, Ken Chen, Margaret M Deangelis, Rui Chen

Faculty, Staff and Students Publications

Single-cell RNA-seq is a powerful tool in decoding the heterogeneity in complex tissues by generating transcriptomic profiles of the individual cell. Here, we report a single-nuclei RNA-seq (snRNA-seq) transcriptomic study on human retinal tissue, which is composed of multiple cell types with distinct functions. Six samples from three healthy donors are profiled and high-quality RNA-seq data is obtained for 5873 single nuclei. All major retinal cell types are observed and marker genes for each cell type are identified. The gene expression of the macular and peripheral retina is compared to each other at cell-type level. Furthermore, our dataset shows an …

Residues And Residue Pairs Of Evolutionary Importance Differentially Direct Signaling Bias Of D2 Dopamine Receptors, María E Terrón-Díaz, Sara J Wright, Melina A Agosto, Olivier Lichtarge, Theodore G Wensel

Faculty, Staff and Students Publications

The D2 dopamine receptor and the serotonin 5-hydroxytryptamine 2A receptor (5-HT2A) are closely-related G-protein–coupled receptors (GPCRs) from the class A bioamine subfamily. Despite structural similarity, they respond to distinct ligands through distinct downstream pathways, whose dysregulation is linked to depression, bipolar disorder, addiction, and psychosis. They are important drug targets, and it is important to understand how their bias toward G-protein versus β-arrestin signaling pathways is regulated. Previously, evolution-based computational approaches, difference Evolutionary Trace and Evolutionary Trace–Mutual information (ET-Mip), revealed residues and residue pairs that, when switched in the D2 receptor to the corresponding residues from 5-HT2A, altered ligand potency …

Examining Multiple Cellular Pathways At Once Using Multiplex Hextuple Luciferase Assaying, Alejandro Sarrion-Perdigones, Lyra Chang, Yezabel Gonzalez, Tatiana Gallego-Flores, Damian W Young, Koen J T Venken

Faculty, Staff and Students Publications

Sensitive simultaneous assessment of multiple signaling pathways within the same cells requires orthogonal reporters that can assay over large dynamic ranges. Luciferases are such genetically encoded candidates due to their sensitivity, versatility, and cost-effectiveness. We expand luciferase multiplexing in post-lysis endpoint luciferase assays from two to six. Light emissions are distinguished by a combination of distinct substrates and emission spectra deconvolution. All six luciferase reporter units are stitched together into one plasmid facilitating delivery of all reporter units through a process we termed solotransfection, minimizing experimental errors. We engineer a multiplex hextuple luciferase assay to probe pathway fluxes through five …

Ultrafast Two-Photon Imaging Of A High-Gain Voltage Indicator In Awake Behaving Mice, Vincent Villette, Mariya Chavarha, Ivan K Dimov, Jonathan Bradley, Lagnajeet Pradhan, Benjamin Mathieu, Stephen W Evans, Simon Chamberland, Dongqing Shi, Renzhi Yang, Benjamin B Kim, Annick Ayon, Abdelali Jalil, François St-Pierre, Mark J Schnitzer, Guoqiang Bi, Katalin Toth, Jun Ding, Stéphane Dieudonné, Michael Z Lin

Faculty, Staff and Students Publications

Optical interrogation of voltage in deep brain locations with cellular resolution would be immensely useful for understanding how neuronal circuits process information. Here, we report ASAP3, a genetically encoded voltage indicator with 51% fluorescence modulation by physiological voltages, submillisecond activation kinetics, and full responsivity under two-photon excitation. We also introduce an ultrafast local volume excitation (ULoVE) method for kilohertz-rate two-photon sampling in vivo with increased stability and sensitivity. Combining a soma-targeted ASAP3 variant and ULoVE, we show single-trial tracking of spikes and subthreshold events for minutes in deep locations, with subcellular resolution and with repeated sampling over days. In the …

Differential Analysis Of Individual Centruroides Vittatus Venom

Symposium of Student Scholars

Scorpions are well known, venomous arthropods (Class: Arachnida, Order: Scorpiones). Their venom is composed of neurotoxins, proteases and cytotoxic peptides which plays a major role in toxic components such as inflammatory, antimicrobial and hemolytic activity. Venom is key for the survival of scorpions as it is involved in defense against prey and in feeding on predators. Centruroides vittatus (bark scorpion) is commonly found in North America, with habitat ranges from Nebraska to southern Texas. For this study, scorpions were harvested from Laredo, Texas (27˚57’ N, 99˚43’ W), held in captivity for 4 months and fed a consistent diet of Acheta …

Multidrug Resistance Regulators Mara, Soxs, Rob, And Rama Repress Flagellar Gene Expression And Motility In Salmonella Enterica Serovar Typhimurium, Srinivas Thota, Lon Chubiz

Biology Department Faculty Works

Production of flagella is costly and subject to global multilayered regulation, which is reflected in the hierarchical control of flagellar production in many bacterial species. For Salmonella enterica serovar Typhimurium and its relatives, global regulation of flagellar production primarily occurs through the control of flhDC transcription and mRNA translation. In this study, the roles of the homologous multidrug resistance regulators MarA, SoxS, Rob, and RamA (constituting the mar-sox-rob regulon in S. Typhimurium) in regulating flagellar gene expression were explored. Each of these regulators was found to inhibit flagellar gene expression, production of flagella, and motility. To different degrees, repression via …

Dual Activities Of Plant Cgmp-Dependent Protein Kinase And Its Roles In Gibberellin Signaling And Salt Stress., Qingwen Shen, Xinqiao Zhan, Pei Yang, Jing Li, Jie Chen, Bing Tang, Xuemin Wang, Xuemin Wang, Yueyun Hong

Biology Department Faculty Works

Cyclic GMP (cGMP) is an important regulator in eukaryotes, and cGMP-dependent protein kinase (PKG) plays a key role in perceiving cellular cGMP in diverse physiological processes in animals. However, the molecular identity, property, and function of PKG in plants remain elusive. In this study, we have identified PKG from plants and characterized its role in mediating the gibberellin (GA) response in rice (Oryza sativa). PKGs from plants are structurally unique with an additional type 2C protein phosphatase domain. Rice PKG possesses both protein kinase and phosphatase activities, and cGMP stimulates its kinase activity but inhibits its phosphatase activity. One of …

Recruitment Of Polycomb-Group Proteins At Giant In Drosophila Embryos, Elnaz Ghotbi Ravandi

Biological Sciences Theses and Dissertations

Polycomb Group (PcG) proteins are evolutionarily conserved epigenetic transcriptional regulators that maintain the transcriptional repression of silenced genes. PcG mediated silencing is divided into two phases: initiation and maintenance. During the initiation phase, PcG proteins initially recognize and bind to their target genes. Once PcG proteins are recruited to their target genes, they can maintain transcriptional repression through an unlimited number of cell cycles. Most studies on PcG proteins have been focused on the maintenance phase of PcG silencing, and the molecular mechanisms by which PcG proteins are initially recruited to their target genes remained unknown. Two models have been …

Mammal Species Inventory Using Various Trapping Methods In Zone 4 Of Billy Barquedier National Park, Belize During Rainy Season, Mersady Redding

Animal Science Undergraduate Honors Theses

Belize is a small country, but it is extremely ecologically diverse. Based on the few studies conducted in Belize, the abundance of mammals is low but diversity is high. Particular findings note the number and identity of species differed between four sites in the Maya Mountains of Belize, indicating that a data set from a single site is not representative of the Neotropical region. Insufficient data is available to estimate current species richness of many areas in Belize, including Billy Barquedier National Park (BBNP). The objective of this study was to explore trapping and documentation methods of terrestrial mammals in …

The Role Of Membrane Domains In Protein And Lipid Sorting During Endocytic Traffic, Blanca B. Diaz-Rohrer

Dissertations and Theses (Open Access)

The lipid and protein composition of the plasma membrane (PM) must be tightly controlled to maintain cellular functionality, despite constant, rapid endocytosis. Because de novo synthesis of proteins and lipids is energetically costly, the cell depends on active recycling to return endocytosed membrane components back to the PM. For most proteins, the mechanisms and pathways of their PM retention remain unknown. The work presented here shows that association with ordered membrane microdomains is fully sufficient for PM recycling and that abrogation of raft partitioning leads to their degradation in lysosomes. These findings support a model wherein ordered membrane domains mediate …

Toward Understanding The Mechanism Of Protein Targeting In The Chloroplast Signal Recognition Particle Pathway, Mercede Furr

Graduate Theses and Dissertations

Protein targeting is a vital cellular function. The signal recognition particle (SRP) pathway is a universally conserved targeting system present in the cytosol and used to co-translationally target many proteins to the inner membrane of prokaryotes and the endoplasmic reticulum of eukaryotes. The chloroplast has a homologous SRP system which post-translationally targets light harvesting chlorophyll binding proteins (LHCPs) to the thylakoid membrane for integration. The chloroplast SRP (cpSRP) is a heterodimer with a 54 kDa subunit equivalent to SRP54 in the canonical pathway. In addition, cpSRP contains a novel 43 kDa subunit which is a unique and irreplaceable component. cpSRP43 …

Structural Basis Of Amino Acid Surveillance By Higher-Order Trna-Mrna Interactions, Shuang Li, Zhaoming Su, Jean Lehmann, Vassiliki Stamatopoulou, Nikoleta Giarimoglou, Frances E Henderson, Lixin Fan, Grigore D Pintilie, Kaiming Zhang, Muyuan Chen, Steven J Ludtke, Yun-Xing Wang, Constantinos Stathopoulos, Wah Chiu, Jinwei Zhang

Faculty, Staff and Students Publications

Amino acid availability in Gram-positive bacteria is monitored by T-box riboswitches. T-boxes directly bind tRNAs, assess their aminoacylation state, and regulate the transcription or translation of downstream genes to maintain nutritional homeostasis. Here, we report cocrystal and cryo-EM structures of Geobacillus kaustophilus and Bacillus subtilis T-box-tRNA complexes, detailing their multivalent, exquisitely selective interactions. The T-box forms a U-shaped molecular vise that clamps the tRNA, captures its 3' end using an elaborate 'discriminator' structure, and interrogates its aminoacylation state using a steric filter fashioned from a wobble base pair. In the absence of aminoacylation, T-boxes clutch tRNAs and form a continuously …

Bipolar Fresh Osteochondral Allograft Transplantation And Joint Reconstruction For Patellar And Trochlear Cartilage Defects, Omid Jalali, Zachary Vredenburgh, John Prodromo, Neilen Benvegnu, George Frederick Rick Hatch

Faculty, Staff and Students Publications

Patellar instability is a debilitating condition, and trauma due to the dislocations may severely damage the articular cartilage of the patellofemoral joint. The lack of healing capacity of cartilage makes treatment of such lesions challenging. In young patients, preservation of native bone and cartilage is a priority, and therefore arthroplasty procedures should be avoided even in relatively larger lesions. Fresh osteochondral allografting has been described for these difficult and complex cases, with recent studies showing promising results. In this surgical technique, we describe the use of bipolar osteochondral allografts of the patella and trochlea and patellofemoral joint reconstruction for large …