Repeatability of image quality in very low-field MRI.

BACKGROUND: Very low-field MR has emerged as a promising complementary device to high-field MRI scanners, offering several advantages. One of the key benefits is that very low-field scanners are generally more portable and affordable to purchase and maintain, making them an attractive option for medical facilities looking to reduce costs. Very low-field MRI systems also have lower RF power deposition, making them safer and less likely to cause tissue heating or other safety concerns. They are also simpler to maintain, as they do not require cooling agents such as liquid helium. However, these portable MR scanners are impacted by temperature, lower magnetic field strength, and inhomogeneity, resulting in images with lower signal-to-noise ratio (SNR) and higher geometric distortions. It is essential to investigate and tabulate the variations in these parameters to establish bounds so that subsequent in vivo studies and deployment of these portable systems can be well informed. PURPOSE: The aim of this work is to investigate the repeatability of image quality metrics such as SNR and geometrical distortion at 0.05 T over 10 days and three sessions per day. METHODS: We acquired repeatability data over 10 days with three sessions per day. The measurements included temperature, humidity, transmit frequency, off-resonance maps, and 3D turbo spin echo (TSE) images of an in vitro phantom. This resulted in a protocol with 11 sequences. We also acquired a 3 T data set for reference. The image quality metrics included computing SNR and eccentricity (to assess geometrical distortion) to investigate the repeatability of 0.05 T image quality. The image reconstruction included drift correction, k-space filtering, and off-resonance correction. We computed the experimental parameters' coefficient of variation (CV) and the resulting image quality metrics to assess repeatability. We have explored the impact of electromagnetic interference (EMI) on image quality in very low-field MRI. The investigation involved varying both the distance and amplitude of the EMI-producing coil from the signal generator to analyze their effects on image quality. RESULTS: The range of temperature measured during the study was within 1.5 °C. The off-resonance maps acquired before and after the 3D TSE showed similar hotspots and were changed mainly by a global constant. The SNR measurements were highly repeatable across sessions and over the 10 days, quantified by a CV of 6.7%. The magnetic field inhomogeneity effects quantified by eccentricity showed a CV of 13.7%, but less than 5.1% in two of the three sessions over 10 days. The use of conjugate phase reconstruction mitigated geometrical distortion artifacts. Temperature and humidity did not significantly affect SNR or mean frequency drift within the ranges of these environmental factors investigated. The EMI experiment showed that as the amplitude increased the SNR decreased, and concurrently the root mean square of the background increased with a rise in EMI amplitude or a reduction in distance. CONCLUSIONS: We found that humidity and temperature in the range investigated did not impact SNR or frequency. Based on the CV values computed session-wise and for the overall study, our findings indicate high repeatability for SNR and magnetic field homogeneity.

Computational design of mRNA vaccines.

mRNA technology has emerged as a successful vaccine platform that offered a swift response to the COVID-19 pandemic. Accumulating evidence shows that vaccine efficacy, thermostability, and other important properties, are largely impacted by intrinsic properties of the mRNA molecule, such as RNA sequence and structure, both of which can be optimized. Designing mRNA sequence for vaccines presents a combinatorial problem due to an extremely large selection space. For instance, due to the degeneracy of the genetic code, there are over 10632 possible mRNA sequences that could encode the spike protein, the COVID-19 vaccines' target. Moreover, designing different elements of the mRNA sequence simultaneously against multiple objectives such as translational efficiency, reduced reactogenicity, and improved stability requires an efficient and sophisticated optimization strategy. Recently, there has been a growing interest in utilizing computational tools to redesign mRNA sequences to improve vaccine characteristics and expedite discovery timelines. In this review, we explore important biophysical features of mRNA to be considered for vaccine design and discuss how computational approaches can be applied to rapidly design mRNA sequences with desirable characteristics.

Iliopsoas Hematoma Progression to Abscess in the Setting of Diabetic Ketoacidosis.

Iliopsoas hematomas (IPH) are defined as a spontaneous or traumatic retroperitoneal collection of blood involving the iliopsoas muscle. In some cases, intramuscular hematomas can progress to abscesses and put the patient at risk for further complications. Our objectives are: to describe the etiology of intramuscular hematoma and psoas abscess, to describe the clinical signs and treatment of intramuscular hematoma and psoas abscess, and to analyze the association between uncontrolled diabetes mellitus and psoas abscess progression, which we achieve through retrospective case analysis and associated literature review on symptom constellation. We present the case of a 40-year-old male patient with a history of diabetes mellitus and alcohol abuse who presented with three days of increasing back and left lower extremity pain, confusion, auditory hallucinations, and fever found to be in diabetic ketoacidosis. Six days prior, the patient presented to the Emergency Department (ED) after being struck by a motor vehicle while ambulating found to have bruising, weakness in his lower extremities, and an L2 vertebrae fracture found on CT. During the presentation, the patient was found to have decreased muscle strength, leukocytosis with elevated lactate, and CT findings suggestive of a left psoas abscess drained by interventional radiology. Vancomycin and Cefepime were used as an empiric antibiotic regimen. The culture of the wound was then found to grow Methicillin-susceptible Staphylococcus aureus (MSSA) bacteria and antibiotics were then adjusted to Vancomycin and Cefazolin. During the patient's hospital stay, he developed two more abscesses on his bilateral psoas muscles, which were promptly percutaneously drained by interventional radiology. This case describes an uncommon progression of an Iliopsoas hematoma to a psoas abscess, likely due to his immunocompromised status secondary to his uncontrolled diabetes mellitus. Uncontrolled diabetes mellitus has been shown in various studies to be an independent risk factor of intramuscular hematoma progress to psoas abscess. We suggest that patients displaying fever, chills, flank pain, limited hip movement, and indications of uncontrolled diabetes should be approached with a high degree of suspicion for a psoas abscess.

Developing and deploying deep learning models in brain magnetic resonance imaging: A review.

Magnetic resonance imaging (MRI) of the brain has benefited from deep learning (DL) to alleviate the burden on radiologists and MR technologists, and improve throughput. The easy accessibility of DL tools has resulted in a rapid increase of DL models and subsequent peer-reviewed publications. However, the rate of deployment in clinical settings is low. Therefore, this review attempts to bring together the ideas from data collection to deployment in the clinic, building on the guidelines and principles that accreditation agencies have espoused. We introduce the need for and the role of DL to deliver accessible MRI. This is followed by a brief review of DL examples in the context of neuropathologies. Based on these studies and others, we collate the prerequisites to develop and deploy DL models for brain MRI. We then delve into the guiding principles to develop good machine learning practices in the context of neuroimaging, with a focus on explainability. A checklist based on the United States Food and Drug Administration's good machine learning practices is provided as a summary of these guidelines. Finally, we review the current challenges and future opportunities in DL for brain MRI.

Intramedullary Spinal Cord Abscess Management: Case Series, Operative Video, and Systematic Review.

BACKGROUND: Intramedullary spinal cord abscess (ISCA) is an extremely rare disease, which has had fewer than 250 reported cases since its initial description in 1830. The condition is limited to level V evidence, limiting the ability for surgeons to characterize and treat it. OBJECTIVE: To report the cases of 2 patients with ISCA and their surgical management: a 59-year-old woman who presented with progressive right hemiparesis and a 69-old man who presented with acute gait instability and significant bilateral shoulder pain. In addition, to report findings from a systematic literature review and associated logistic regression analysis. METHODS: A MEDLINE and Embase search was conducted using the keywords "intramedullary," "spinal cord," "abscess," and "tuberculoma" and the results were screened for case reports. A logistic regression model was fit 100 times on data to retrieve predictor odds ratios. RESULTS: Two hundred case reports of ISCA were identified between 1965 and 2022. Logistic regression determined that the only variables of significance were age (P < 0.01) and antibiotics (P < 0.05). CONCLUSIONS: Treatment of ISCAs has significantly improved over the years. However, ISCAs are still poorly understood. Our recommendations can be used to guide diagnosis and treatment.

A Rare Presentation of a Complex Mixed Autoimmune Encephalitis Diagnosis: A Case Report and Literature Review.

This case report presents a unique case of a difficult differential diagnosis of autoimmune encephalitis (AE) in the setting of Mycoplasma pneumoniae. A 40-year-old female with a history of Hashimoto thyroiditis, polycystic ovarian syndrome, and a lower respiratory infection presented to the emergency department with new-onset progressive neurological symptoms. These included generalized tonic-clonic seizure and worsening respiratory status that required intubation and tracheostomy. Blood cultures returned positive for M. pneumoniae. We concluded this to be a mixed diagnosis case of anti-glutamic acid decarboxylase 65 (anti-GAD65), Bickerstaff's brainstem encephalitis (BBE), Hashimoto's encephalopathy (HE), and Miller Fisher Syndrome (MFS) concurrently in the setting of M. pneumoniae. Initial treatment with intravenous immunoglobulin showed minimal improvement; however, subsequent treatment with plasmapheresis proved to be beneficial for the patient. Over the course of the plasma exchange therapy (PLEX), the patient slowly became more alert, attentive, and verbal. She was able to answer simple questions and follow commands. Common trends of age, gender, presenting symptoms, associated antibodies, and sessions of PLEX in different AE diseases were identified through a literature review. Only 69.7% of the cases implemented PLEX or plasmapheresis. Currently, there is no standard protocol for the treatment of AE. Our case report aims to present a clinically complicated example of AE and to provide further evidence to support PLEX as an important therapeutic option.

A Rare Case of Transitional Cell Carcinoma in an Adult Male With Neurofibromatosis Type 1.

Neurofibromatosis type 1 (NF1) is a multisystem genetic disorder characterized by café-au-lait macules on the skin, Lisch nodules of the iris, and predisposition to a wide array of tumors. These include neurofibromas, pheochromocytomas, and gastrointestinal stromal tumors (GIST). While there is documented evidence to suggest that the NF1 gene may play a role in the pathogenesis of transitional cell carcinoma (TCC) of the bladder, there is a paucity of documented cases of TCC in patients with NF1. Our patient is a 53-year-old male with a known diagnosis of NF1 and prior history of GIST who presented to the emergency department with lower abdominal pain, constipation, hematuria, and oliguria. The patient was found to have marked colonic distention prompting a decompressive cecostomy with subsequent return of bowel function. Cystoscopy was performed at this time for hematuria, which revealed a 9 cm bladder mass. Pathology showed a high-grade TCC of the bladder with nuclear pleomorphism and necrosis. The patient was treated with gemcitabine and cisplatin neoadjuvant chemotherapy, followed by cystoprostatectomy with bilateral pelvic lymphadenectomy and ileal conduit urinary diversion. Our case report is the first documented instance in the United States exhibiting an in vivo association of NF1 with the development of TCC of the bladder, an association previously identified in vitro. We hope our work inspires further investigation into this unique association.

Immune Checkpoint Inhibitor-Associated Thrombotic Thrombocytopenic Purpura in a Patient With Metastatic Non-Small-Cell Lung Cancer.

BACKGROUND: Immune-related adverse events (irAEs) are secondary reactions related to treatment with immune checkpoint inhibitors (ICIs). There have been six cases published reporting on an association between patients undergoing treatment with ICIs and the occurrence of acquired thrombotic thrombocytopenic purpura (TTP). CASE REPORT: We report a 61-year-old male receiving treatment with chemoimmunotherapy followed by pembrolizumab maintenance therapy for advanced non-small-cell lung cancer, presenting with bleeding symptoms, anemia, and thrombocytopenia. The patient received pembrolizumab seven times in total, in three-week cycles. Laboratory testing demonstrated hemolytic anemia, which, in combination with other findings, suggested thrombotic microangiopathy (TMA). PLASMIC scoring and specialized testing with ADAMTS13 activity and inhibitor confirmed a diagnosis of TTP. The patient was started on therapy with plasmapheresis and glucocorticoids, resulting in clinical improvement. The patient chose to leave the hospital under the care of home hospice and died approximately one month after being discharged. CONCLUSIONS: Of the six cases of ICI-induced TTP, only one other was treated with pembrolizumab to our knowledge to date. Our patient experienced an adverse reaction marked by thrombocytopenia and hematuria after drug exposure. With symptom improvement after ICI discontinuation and recurrence on readministration, a presumptive diagnosis of ICI-associated TTP was made. This case report and literature review emphasize the need for close observation of patients undergoing ICI therapy for potential rare irAEs. The further investigation aimed at the study of risk factors, disease severity, and treatment response to this form of secondary TTP is needed to guide treatment decisions.

Red Blood Cell Exchange in a Patient With Extramedullary Hematopoiesis and Cor Pulmonale Secondary to Beta Thalassemia.

RATIONALE: Beta thalassemia is a congenital defect in the production of the beta globin chain. Patients with beta thalassemia major will have higher levels of hemoglobin F (HbF), which is suboptimal in releasing oxygen to tissue. Herein, we describe the use of red blood cell (RBC) exchange transfusion, a therapy typically used in sickle cell patients, in the management of a patient with beta thalassemia with extensive extramedullary hematopoiesis and elevated levels of HbF. Patient concerns: A 34-year-old male of mixed African American and Southeast Asian descent with a known history of beta thalassemia major presented with progressive dyspnea on exertion with marked fatigue. Diagnoses: The patient was transferred to our facility for management of acute hypoxemic, hypercapnic respiratory failure associated with cor pulmonale. INTERVENTIONS: The patient was initially managed with non-invasive positive pressure support ventilation (NIPPV) and intravenous diuresis. Hydroxyurea and epoprostenol nebulization were added to his treatment regimen; however, he progressively became more unstable, necessitating inotropic support. With extramedullary hematopoiesis leading to mass-like effect on critical organs and very high HbF (96%) thought to contribute to his presentation, red blood cell exchange transfusion was initiated once the blood pressure stabilized. OUTCOMES: The patient clinically improved, and was discharged home within a week on supplemental oxygen by nasal cannula and long-term red blood cell exchange. LESSONS: We postulated that significantly elevated HbF contributed to the patient's chronic hypoxia and subsequent respiratory complications. Based on the patient's clinical improvement following the intervention, we believe that RBC exchange transfusion could be considered in the management of beta thalassemia patients with significantly elevated levels of HbF.

Development of a potent Zika virus vaccine using self-amplifying messenger RNA.

Zika virus (ZIKV) is the cause of a pandemic associated with microcephaly in newborns and Guillain-Barre syndrome in adults. Currently, there are no available treatments or vaccines for ZIKV, and the development of a safe and effective vaccine is a high priority for many global health organizations. We describe the development of ZIKV vaccine candidates using the self-amplifying messenger RNA (SAM) platform technology delivered by cationic nanoemulsion (CNE) that allows bedside mixing and is particularly useful for rapid responses to pandemic outbreaks. Two immunizations of either of the two lead SAM (CNE) vaccine candidates elicited potent neutralizing antibody responses to ZIKV in mice and nonhuman primates. Both SAM (CNE) vaccines protected these animals from ZIKV challenge, with one candidate providing complete protection against ZIKV infection in nonhuman primates. The data provide a preclinical proof of concept that a SAM (CNE) vaccine candidate can rapidly elicit protective immunity against ZIKV.

Exhaled breath condensate metabolome clusters for endotype discovery in asthma.

BACKGROUND: Asthma is a complex, heterogeneous disorder with similar presenting symptoms but with varying underlying pathologies. Exhaled breath condensate (EBC) is a relatively unexplored matrix which reflects the signatures of respiratory epithelium, but is difficult to normalize for dilution. METHODS: Here we explored whether internally normalized global NMR spectrum patterns, combined with machine learning, could be useful for diagnostics or endotype discovery. Nuclear magnetic resonance (NMR) spectroscopy of EBC was performed in 89 asthmatic subjects from a prospective cohort and 20 healthy controls. A random forest classifier was built to differentiate between asthmatics and healthy controls. Clustering of the spectra was done using k-means to identify potential endotypes. RESULTS: NMR spectra of the EBC could differentiate between asthmatics and healthy controls with 80% sensitivity and 75% specificity. Unsupervised clustering within the asthma group resulted in three clusters (n = 41,11, and 9). Cluster 1 patients had lower long-term exacerbation scores, when compared with other two clusters. Cluster 3 patients had lower blood eosinophils and higher neutrophils, when compared with other two clusters with a strong family history of asthma. CONCLUSION: Asthma clusters derived from NMR spectra of EBC show important clinical and chemical differences, suggesting this as a useful tool in asthma endotype-discovery.

T cell receptor diversity in the human thymus.

A diverse T cell receptor (TCR) repertoire is essential for adaptive immune responses and is generated by somatic recombination of TCRα and TCRß gene segments in the thymus. Previous estimates of the total TCR diversity have studied the circulating mature repertoire, identifying 1 to 3×10(6) unique TCRß and 0.5×10(6) TCRα sequences. Here we provide the first estimate of the total TCR diversity generated in the human thymus, an organ which in principle can be sampled in its entirety. High-throughput sequencing of samples from four pediatric donors detected up to 10.3×10(6) unique TCRß sequences and 3.7×10(6) TCRα sequences, the highest directly observed diversity so far for either chain. To obtain an estimate of the total diversity we then used three different estimators, preseq and DivE, which measure the saturation of rarefaction curves, and Chao2, which measures the size of the overlap between samples. Our results provide an estimate of a thymic repertoire consisting of 40 to 70×10(6) unique TCRß sequences and 60 to 100×10(6) TCRα sequences. The thymic repertoire is thus extremely diverse. Moreover, extrapolation of the data and comparison with earlier estimates of peripheral diversity also suggest that the thymic repertoire is transient, with different clones produced at different times.

Symptoms and medical conditions in 204 912 patients visiting primary health-care practitioners in India: a 1-day point prevalence study (the POSEIDON study).

BACKGROUND: India has one of the highest disease burdens in the world. A better understanding of what ails India will help policy makers plan appropriate health-care services and infrastructure development, design medical education curricula, and identify health research priorities that are relevant to the needs of the country. The POSEIDON study aimed to record the prevalence of symptoms and medical conditions for which patients visit a primary health-care practitioner in India. METHODS: We randomly selected 12 000 general practitioners, general physicians, and paediatricians from 880 cities and towns and invited them to record demographic details, symptoms, and medical conditions for every patient they saw on Feb 1, 2011. A further 1225 practitioners volunteered to participate and their responses were included. We did simple descriptive analyses of prevalence rates and used χ(2) tests to study comorbid associations. Through application of systems biology methods, we visualised inter-relations between organ involvement of diseases and symptoms and deciphered how these associations change with age and gender. FINDINGS: We included responses from 7400 health-care practitioners, which represented data for 204 912 patients, who presented with 554 146 reasons for visit. Fever (35·5%) was the most common presenting symptom. More than half of all patients presented with respiratory symptoms across all age groups and regions of India. Other common presentations were digestive system symptoms (25%), circulatory symptoms (12·5%), skin complaints (9%), and endocrine disorders (6·6%). Hypertension (14·52%), obstructive airways diseases (14·51%), and upper respiratory tract infections (12·9%) were the most common diagnoses reported. Of note was that 21·4% of all patients with hypertension reported by the primary health-care practitioners were younger than 40 years. Anaemia was the fourth most common disease reported by these health-care practitioners and was most common in women of menstrual age living outside metro cities. INTERPRETATION: The POSEIDON study provides insight into the reasons that patients visit primary health-care practitioners in India; our results highlight important social and medical challenges in the developing world. FUNDING: Chest Research Foundation, Council of Scientific and Industrial Research-Institute of Genomics and Integrated Biology (CSIR-IGIB), and Cipla Ltd.

Overexpression of cloned RhsA sequences perturbs the cellular translational machinery in Escherichia coli.

RhsA is a member of the multigene Rhs family and consists of a complex genetic sequence. This sequence consists of several distinct components, including a GC-rich core (core open reading frame [ORF]), an AT-rich extension (ext-a1) of the core ORF and an AT-rich region following the core extension (dsORF-a1). The functions of RhsA and the different distinct components, which can include open reading frames, are not well understood. Here, we study the effect of overexpression of the ext-a1 sequence and the ext-a1 3' region, which includes a partial sequence of dsORF-a1, on Escherichia coli cells. Cells expressing these sequences show reduced cell growth and cell viability. The expression of these sequences dramatically affects different components of the transcription and translation machinery. Transcriptomic analysis reveals an increase in the expression of genes involved in transcription, RNA processing, and nucleotide biosynthesis and metabolism and a decrease in the expression of amino acid biosynthesis genes and transfer RNAs. Further, expression of the above-mentioned RhsA components increases ribosomal gene expression, as well as rRNA and ribosome abundance. Proteomic analysis reveals an overall reduction of protein expression at the genome-wide level in cells expressing the above-mentioned RhsA components. Based on these observations, we suspect a translation product of ext-a1 affects different regulatory mechanisms that control rRNA synthesis.

Bioprocess optimization for cell culture based influenza vaccine production.

Uncertainties and shortcomings associated with the current influenza vaccine production processes demand attention and exploration of new vaccine manufacture technologies. Based on a newly developed mammalian cell culture-based production process we investigated selected process parameters and describe three factors that are shown to impact productivity, process robustness and development time. They are time of infection, harvest time and virus input, or multiplicity of infection (MOI). By defining the time of infection as 4-5 days post cell seeding and harvest time as 2-3 days post-infection and comparing their effect on virus production, MOI is subsequently identified as the most impactful process parameter for live attenuated influenza vaccine (LAIV) manufacture. Infection at very low MOI (between 10(-4) and 10(-6) FFU/cell) resulted in high titer virus production (up to 30-fold productivity improvement) compared to higher MOI infections (10(-3) to 10(-2) FFU/cell). Application of these findings has allowed us to develop a platform process that can reduce the development time to approximately three weeks for an influenza vaccine manufacture process for new strains.

Shotgun proteomics using the iTRAQ isobaric tags.

Shotgun proteomic methods involving isobaric tagging of peptides enable high-throughput proteomic analysis. iTRAQ reagents allow simultaneous identification and quantitation of proteins in four different samples using tandem mass spectrometry (MS). In this article, we provide a brief description of proteome analysis using iTRAQ reagents and review the current applications of these reagents in proteomic studies. We also compare different aspects of protein identification including protein sequence coverage and proteome coverage obtained using iTRAQ reagents with those using other shotgun proteomic techniques. We briefly discuss the issue of isotope purity correction in measured peak areas during protein quantitation using iTRAQ reagents. Finally, we conclude with some of the current challenges in MS-based proteomic analysis that are limiting protein identifications obtained by different shotgun proteomic methods.

Improved understanding of gene expression regulation using systems biology.

This article reviews the current state of systems biology approaches, including the experimental tools used to generate 'omic' data and computational frameworks to interpret this data. Through illustrative examples, systems biology approaches to understand gene expression and gene expression regulation are discussed. Some of the challenges facing this field and the future opportunities in the systems biology era are highlighted.

A comparison of the consistency of proteome quantitation using two-dimensional electrophoresis and shotgun isobaric tagging in Escherichia coli cells.

An important consideration in the measurement of quantitative changes in protein expression is the consistency of the observations for a given technique as well as the reproducibility of the experiment. A quantitative assessment of the technical and biological variability is crucial to avoid erroneous inferences and conclusions. Two methods for measuring quantitative changes in protein expression are two-dimensional electrophoresis (2-DE) and shotgun proteomics of isobaric-tagged samples using iTRAQ reagents. An assessment of changes in Escherichia coli protein expression in response to rhsA induction demonstrates that half of the quantified protein expression ratios have a coefficent of variation (CV) less than 0.31 using 2-DE and less than 0.24 using isobaric tags; whereas 95% of the quantified protein expression ratios have a CV less than 0.81 using 2-DE and less than 0.53 using isobaric tags. The selective removal of outlier data points from the shotgun method using Grubb's and Rosner's statistical outlier tests improves the consistency of the quantitation data obtained.

Quantitative analysis of protein expression using amine-specific isobaric tags in Escherichia coli cells expressing rhsA elements.

We describe the use of amine-specific isobaric tags for protein expression quantification to study the effect of rhsA element over-expression in Escherichia coli. The use of an isobaric tagging strategy facilitates a shotgun approach to proteomic analysis and enables quantitation of up to four samples in parallel, based on the reporter ion series using tandem mass spectrometry (MS/MS). Using a liquid chromatography matrix-assisted laser desorption/ionization approach, 23,139 MS/MS spectra were collected. Five thousand sixty-three peptides derived from 780 proteins were quantified including several lower abundance proteins, such as transcription factors, DnaB and DnaG. More than 65% of the proteins had at least two high confidence peptide matches per protein (p<0.05). Further, a statistical test based on the Grubb's and Rosner's tests was able to discriminate outlier data. The removal of outlier data had no significant effect on the functional categories of proteins that were represented in the study.

Functional genomics and proteomics as a foundation for systems biology.

Developments in high-throughput measurement technologies for biological molecules have created a paradigm shift in modern life science research. The field of systems biology attempts to provide a systems-level understanding by systematically organising the genomic, functional genomic and proteomic data obtained from genetic and environmental perturbations of interest and using the data to build a descriptive and mechanistic model of the biological phenomena. The goal is to build a mathematical framework with some predictive abilities. This review highlights the need for system-level understanding, lists some of the high-throughput measurement tools of importance in systems biology, reviews various types of experimental and computational approaches being used in systems biology research and attempts to address some of the challenges facing this research community.