Publications by authors named "Sanghvi N"

Metastasis is a leading cause of cancer-related deaths, yet understanding how metastatic tumors adapt from their origin to their target tissues remains a fundamental challenge. To address this, we assessed whether primary and metastatic tumors more closely resemble their tissues of origin or target tissues in terms of gene expression. We analyzed expression profiles from multiple cancer types and normal tissues, including single-cell and bulk RNA sequencing data from both paired and unpaired patient cohorts.

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Metastasis is a leading cause of cancer-related deaths, yet understanding how metastatic tumors adapt from their origin to target tissues is challenging. To address this, we assessed whether primary and metastatic tumors resemble their tissue of origin or target tissue in terms of gene expression. We analyzed gene expression profiles from various cancer types, including single-cell and bulk RNA-seq data, in both paired and unpaired primary and metastatic patient cohorts.

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Despite more than a century of study, consensus on the molecular basis of allostery remains elusive. A comparison of allosteric and non-allosteric members of a protein family can shed light on this important regulatory mechanism, and the bacterial biotin protein ligases, which catalyze post-translational biotin addition, provide an ideal system for such comparison. While the Class I bacterial ligases only function as enzymes, the bifunctional Class II ligases use the same structural architecture for an additional transcription repression function.

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Background: The purpose of these clinical studies was to validate a Tissue Change Monitoring (TCM) algorithm in vivo. TCM is a quantitative tool for the real-time assessment of HIFU dose. TCM provides quantitative analysis of the backscatter pulse echo signals (pre and immediately post HIFU) for each individual ablative site, using ultrasonic tissue characterization as a surrogate for monitoring tissue temperature.

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Objective: To calibrate a 12-mm high-intensity focused ultrasound (HIFU) probe to produce histologically verifiable complete tissue necrosis through thermal energy delivery while maintaining safety in ablation of porcine renal tissue.

Methods: The study was approved by the animal research committee at our institution. A HIFU probe on a fixed arm was introduced, and ablation was subsequently carried out robotically (under computer control) at 2 planned locations within each kidney at varying energy levels.

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The synthesis of a 16-residue, stable isotopically labeled peptide is described for use as a LC-MS/MS (Liquid chromatography-mass spectrometry/mass spectrometry) internal standard in bioanalytical studies. This peptide serves as a single universal surrogate peptide capable of quantifying a wide variety of immunoglobulin G and Fc-fusion protein drug candidates in animal species used in pre-clinical drug development studies. An efficient synthesis approach for this peptide was developed using microwave-assisted solid phase peptide synthesis (SPPS) techniques, which included the use of a pseudoproline dipeptide derivative.

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Objective: Individuals post-stroke display abnormal Group Ia reflex excitability. Pedaling has been shown to reduce Group Ia reflexes and to normalize the relationship between EMG and reflex amplitude in the paretic soleus (SO). The purpose of this study was to determine whether these changes extend to the paretic quadriceps.

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The field of magnetic resonance imaging-guided high-intensity focused ultrasound surgery (MRgFUS) is a rapidly evolving one, with many potential applications in neurosurgery. The first of 3 articles on MRgFUS, this article focuses on the historical development of the technology and its potential applications in modern neurosurgery. The evolution of MRgFUS has occurred in parallel with modern neurological surgery, and the 2 seemingly distinct disciplines share many of the same pioneering figures.

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Purpose: High intensity focused ultrasound for renal lesions is still experimental. In a porcine model we evaluated the safety and efficacy of a newly designed laparoscopic high intensity focused ultrasound probe and software that allows real-time ultrasound guidance during renal tissue ablation.

Materials And Methods: A Sonatherm 600 high intensity focused ultrasound system with a newly designed laparoscopic high intensity focused ultrasound probe was used through a standard Endopath 18 mm port.

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Background: Physical therapists may prescribe stretching exercises for individuals with stroke to improve joint integrity and to reduce the risk of secondary musculoskeletal impairment. While deficits in passive range of motion (PROM) exist in stroke survivors with severe hemiparesis and spasticity, the extent to which impaired lower extremity PROM occurs in community-ambulating stroke survivors remains unclear. This study compared lower extremity PROM in able-bodied individuals and independent community-ambulatory stroke survivors with residual stroke-related neuromuscular impairments.

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This review evaluates the thermal mechanism for ultrasound-induced biological effects in postnatal subjects. The focus is the evaluation of damage versus temperature increase. A view of ultrasound-induced temperature increase is presented, based on thermodynamic Arrhenius analyses.

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Objective: High-intensity focused ultrasound (HIFU) permits targeted homogeneous ablation of tissue. The objective of this phase 1 study was to evaluate the feasibility of HIFU ablation of small renal tumours under laparoscopic control.

Patients And Methods: Ten kidneys with solitary renal tumours were treated with a newly developed 4.

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Purpose: We examined the safety and potential efficacy of transrectally delivered high intensity focused ultrasound for the full gland ablation of previously untreated localized prostate cancer.

Materials And Methods: A total of 20 patients with localized prostate cancer underwent 1 to 3 high intensity focused ultrasound treatments of the prostate. The primary outcome was safety and the secondary outcomes were prostate specific antigen, prostate biopsy and quality of life measures.

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The prevalence of hypertrophic cardiomyopathy is estimated at 1:500 in the general population. Of these patients, approximately 1% develops midcavitary obstruction and subsequent apical aneurysm. We present a brief review of the literature on apical hypertrophic cardiomyopathy (HCM) using a rare case-based example.

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Current planning methods for transrectal high-intensity focused ultrasound treatment of prostate cancer rely on manually defining treatment regions in 15-20 sector transrectal ultrasound (TRUS) images of the prostate. Although effective, it is desirable to reduce user interaction time by identifying functionally related anatomic structures (segmenting), then automatically laying out treatment sites using these structures as a guide. Accordingly, a method has been developed to effectively generate solid three-dimensional (3-D) models of the prostate, urethra, and rectal wall from boundary trace data.

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Background: Programmed electrical stimulation of the heart as a method to induce tachyarrhythmias has been described since the 1960s. To date, no study has examined optimal drive cycle length in the induction of ventricular fibrillation (VF) during defibrillation threshold testing after implantable cardioverter-defibrillator placement. We hypothesized that longer drive cycle length, by means of the longer action potential duration, would promote intramyocardial phase 2 reentry and facilitate induction of VF.

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Purpose: High intensity focused ultrasound has been performed for transrectal and extracorporeal thermal ablation of tissues. We developed and tested a laparoscopic probe that allows real-time ultrasound imaging during partial renal ablation using high intensity focused ultrasound.

Methods: A Sonablate 200 (Focus Surgery, Indianapolis, Indiana) high intensity focused ultrasound system with a modified 18 mm.

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Objectives: To present our preliminary clinical results of transrectal high-intensity focused ultrasound (HIFU) in Stage T1b-2N0M0 prostate cancer. Efforts are being made to provide minimally invasive alternative treatment options with equal efficacy and fewer side effects. HIFU delivers ultrasound energy with rapid thermal necrosis of tissue in the focal region without damaging the surrounding tissue.

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The effect of array geometry on the steering performance of ultrasound phased arrays is examined theoretically, in order to maximize array performance under the given anatomical constraints. This paper evaluates the performance of arrays with spherical and cylindrical geometry, determined by using computer simulations of the pressure fields produced at various extremes of steering. The spherical segment arrays were truncated for insertion into the rectum, and contained either annular or linear elements.

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In a study involving 10 different sites, independent results of measurements of ultrasonic properties on equivalent tissue-mimicking samples are reported and compared. The properties measured were propagation speed, attenuation coefficients, and backscatter coefficients. Reasonably good agreement exists for attenuation coefficients, but less satisfactory results were found for propagation speeds.

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Objective: To establish clinical efficacy and safety of High Intensity Focused Ultrasound (HIFU) for the treatment of benign prostatic hyperplasia (BPH) in a multiple site clinical study.

Methods: Seven clinical sites were set up for the studies, five in the USA, one in Canada and one in Japan respectively. Sixty two patients were enrolled in these three studies.

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The effect of temperature and thermal dose (equivalent minutes at 43 degrees C) on ultrasonic attenuation in fresh dog muscle, liver, and kidney in vitro, was studied over a temperature range from room temperature to 70 degrees C. The effect of temperature on ultrasonic absorption in muscle was also studied. The attenuation experiments were performed at 4.

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Time shifts in echo signals returning from a heated volume of tissue correlate well with the temperature changes. In this study the relationship between these time shifts (or delays) and the tissue temperature was investigated in excised muscle tissue (turkey breast) as a possible dosimetric method. Heat was induced by the repeated activation of a sharply focused high-intensity ultrasound beam.

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